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Circuit Idea/How to Understand Circuits

contents - present - invent - stage

What is "Understanding"?
In order to understand circuits, first we have to reveal the basic ideas on which they are built. But what is actually meant by "understanding"? What is the difference between "analyze" and "understand"?

Analysis consists in applying mainly formal methods, while understanding - in heuristics. So that understanding electronic circuits consists in analyzing them by heuristic means. To understand a circuit is to recognize the basic idea on which it is built, and this fundamental idea is represented by a block diagram and an algorithm of action. Basic ideas are not necessarily electrical and are independent of their particular circuit implementations. The element base (tubes, transistors, op-amps) is constantly changing, but the fundamental ideas remain; they are immortal... they are eternal!

Technology of Understanding
In the process of understanding unknown electronic circuits, five stages can be distinguished: analyzing the structure of the circuit, analyzing the circuit operation, recognizing known basic circuit principles, searching for a similar idea in other circuits or life situations, summarizing the results in a new circuit principle. Here, they are separated for methodological purposes, but in most cases in practice they are performed simultaneously.

The understanding technology is illustrated below with an example circuit of op-amp inverting summer.

Stage I: Analyzing the circuit structure
Understanding an electronic circuit begins with an analysis of its structure. Figuratively speaking, this consists in discovering familiar patterns in the unfamiliar circuit diagram. For this purpose, the diagram is carefully examined, making an attempt to recognize already known more elementary devices in it. The functional groups of sub-devices and elements forming the recognized known devices are marked (circled) and labeled. This decomposition process continues by breaking down the circuit into even more elementary building blocks (in the specific example below, the names of the building blocks are in italics).

EXAMPLE. The popular analog circuit of op-amp inverting summer (e.g., with two inputs) is traditionally presented as consisting of four elements - resistor R1, resistor R2, resistor R and op-amp OA (Fig. 1a); then it is analyzed formally. Presented in this way, however, the functions of the individual elements are not visible in it (as they say, "you can see the trees, but you can't see the forest"). Let's try to see the functional sub-circuit building blocks...

1. Voltage-to-current converter. However, if we look carefully at the circuit, we will easily recognize the elementary voltage-to-current converters in the resistors R1 and R2 (Fig. 1b). In the op-amp inverting summer, the operational amplifier A maintains almost zero voltage at its input due to the high gain and the presence of negative feedback. Therefore, resistors R1 and R2 are "virtually grounded" to the right and convert input voltages to currents, according to Ohm's law written in its usual form I = V/R.

2. Current summer. The input currents flowing through resistors R1 and R2 are summed at the common point (node) connected to the op-amp inverting input, according to KCL. Thus, the node functions as an elementary current summer.

3. Current-to-voltage converter. The total current produced by the output of the current summer flows through the resistor R and is converted to a voltage, again according to Ohm's law, but now written in its "inverse" form V = I.R. Thus, the resistor R acts as the dual current-to-voltage converter.

4. Passive voltage summer. Then, if we combine these elements into one whole, we will recognize in it the circuit of a passive voltage summer. Thus the set of voltage-to-current converters (resistors R1, R2), the current summer (node) and the current-to-voltage converter (resistor R) form a passive voltage-to-voltage summer.

5. Operational amplifier. Finally, it remains only to clarify the role of the op-amp (Fig. 1f), but this will be done best after considering the circuit operation.

Stage II: Analyzing the circuit operation
After analyzing the structure, we continue the understanding of the unknown circuit by studying its operation. We now attempt to discover the fundamental principles underlying it. We can use thought, simulation and real experiments to explore the circuit. At the stage of understanding, we most often use thought experiments, because the human brain is a wonderful research laboratory in which we can conduct sophisticated mental experiments. Figuratively speaking, we can "project" the operation of electronic circuits and "experiment" with them on the mental screen of our imagination. At this stage, we can support and verify thought experiments using simulation software and real experiments in the laboratory.

Preparing the circuit to analyze its operation
Drawn in its conventional compact form, the analyzed circuit is easy to remember but not easy to understand. Therefore, we need to enrich it with additional elements that will help us to realize it better. For this purpose:

 * Connect the input sources (voltage or current depending on the circuit) to the circuit inputs. Instead of AC sources with unclear (at a given moment) polarity, it is better to use DC sources with known value and polarity (preferably positive at the beginning). Thus, we can take a momentary "picture" of the electrical quantities in the circuit.

 * Connect the load to the circuit output (preferably with ohmic resistance).

 * Connect the power supplies to the circuit.

 * Assume that circuit components are ideal: operational amplifiers have an infinitely large gain, negligible input currents and bias voltages, negligible output resistance; transistors do not have base current (when this is permissible) and threshold voltage UBE0; their characteristic is linear; the resistance of the resistors does not depend on the temperature; the capacitors do not leak; the double elements are completely symmetric (they have no difference in parameters), etc. In short, we forget about the device imperfections elements and leave all these problems for the following quantitative analysis.

 * Use precisely the imperfections of electronic devices (this is actually the popular inventive principle of "turning harm into good" or "blessing in disguise"). Examples: the temperature influence on the resistance of resistors; the VBE voltage of the transistor PN junction; use of the "harmful" forward voltage drop VF of PN junction as a reference voltage, use of the base current IB of the transistor as a compensating input current of an operational amplifier, etc. In these cases, the imperfections of electronic devices are deliberately enhanced and attention is focused on them.
 * Prepare the studied circuit (before starting the mental experiments) for the next application of the visualized electrical quantities. For this purpose, we drawn it in a spatial ("geometric") form: the positive sources are located above, and the negative - below the "zero" line; the resistors on which potential diagrams will be imposed are "stretched"; an appropriate circuit topology is chosen so that the current loops do not cross much, etc.
 * Visualize the invisible electrical quantities by superimposing voltage and current pictures on the circuit diagram:
 * Represent voltages by bars in red (association with pressure, energy), the height of which is proportional to the voltages across the corresponding elements.
 * Represent currents by closed lines (loops) in green or blue color (association with water flow), the thickness of which is proportional to the current magnitude.

EXAMPLE. In the conceptual circuit of the op-amp inverting summer, the input voltages and voltage drops across the resistors R1 and R2 are positive; so we draw these elements above the "zero voltage line" (Fig. 2). The voltage drop across the resistor R and the compensating voltage VS are negative - therefore, we draw them below the "zero voltage line". Also, we draw the input circuits (VIN1-R1 and VIN2-R2), the output circuit (VS-R) and the load circuit (VS-RL) in such a way that we can later impose non-crossing current loops (this applies to the topology of the entire circuit).

Exploring the circuit
We can explore the circuit operation by mentally applying input signals and imagining what its response is. In order to get a qualitative idea of  analog circuits, in most cases three levels of the input signals (zero, positive and negative) are completely sufficient, and for digital ones - two levels corresponding to logical "0" and logical "1". So, we can explore the circuit in the following sequence:

STEP 1. We assume that, at the first moment, the input signals applied to the circuit are equal to zero. At this initial state, we try to get an idea of what the voltages at the individual circuit points, the voltages across the elements and the currents in the individual branches of the circuit are. Then we draw the pictures of voltages and currents.

For example, in the circuit of the op-amp inverting summer, at zero input voltages VIN1 and VIN2, all voltages and currents inside the circuit are also zero (Fig. 2a.)

STEP 2. We change one of the input signals a jump in the positive direction and observe the circuit reaction to this impact. We are trying to get an idea of how the voltages and currents change in the individual points and branches of the circuit. We deliberately enlarge the duration of the transition so that it becomes commensurate with the speed of our human thinking. Also, we deliberately present inertialess, proportional active electronic devices (transistors, operational amplifiers, etc.) as slow, inertial, integral.

Input change. For example, in the circuit of the op-amp inverting summer (Fig. 2b), we change the input voltage V1 with a jump. As a result, its voltage bar stretches instantly upwards. We (playing the role of the operational amplifier A) are surprised and cannot react at first; as a result, the compensating voltage bar VS remains of zero length. The input source VIN1 passes current I1 through the circuit VIN1-R1, which then diverts through the circuit R2-VIN2 (the source V2 at the first moment is a consumer!), R-VS and finally returns back to where it started. We draw the trajectories of these currents with the corresponding thicknesses and indicate with arrows the current directions.

The voltage at point A rises and the voltage bar VR1 stretches upwards (as if the input source VIN1 "pulls" point A in a positive direction). The zero indicator I shows a positive bias and we begin to compensate it by changing the voltage VS in a negative direction until the zero indicator I shows zero voltage again. As a result, the voltage bars VR and VR1 stretch downward and eventually equalize in length.

Restoring the equilibrium. By "sucking" more and more of the current I1, the source VS "pulls" the voltage at point A down until it is zeroed. Thus, there are two grounds in the circuit - real and virtual, the difference in the voltages of which we read with the zero indicator I. At the end of this process, the source VS diverts the entire current I1 through itself and its loop thickens to the value I1 = VIN1/R1.

STEP 3. Now we restore the input signal to the initial zero position and then change it with a jump in the opposite negative direction. We re-examine the reaction of the circuit to this new impact, trying to imagine how the voltages and currents change in the individual points and branches of the circuit. For the sake of good understanding, we redraw the diagram so that it corresponds to the new polarity.

In our example circuit of an inverting summer, we plot the input voltage VIN 1 below the "zero voltage line". The voltage drop on the resistor R and the compensating voltage VS become positive - that is why we draw them above the "zero voltage line". Finally, we reverse the arrows of the current loops because the currents change their direction.

STEP 4. We reset the negative input voltage VIN1 and start experimenting with the next input voltage VIN2. So, in the circuit of the inverting summer, we change the input voltage VIN2 with a jump. The "op-amp" is now forced to change the voltage VS further in the negative direction to re-establish equilibrium.

By further changing the voltage VS in the negative direction until the zero indicator I shows zero voltage again, the "op-amp" manages to restore the balance again.

STEP 5. We can deep the research by simultaneously changing several input signals or circuit parameters. In practice, we are most often limited to two quantities, which change in the same direction (common mode) or in opposite directions (differential mode).

STEP 6. In order to expand our idea about the circuit operation, we can use the whole "arsenal" of analogies. For example, we can imagine that the input source of voltage is a compressor that starts pumping air into the device under study (pneumatic analogy) and we observe how the pressure changes at individual points and the air flow rate. Or we can compare the source with a column of water raised above the earth's surface (hydraulic analogy), and observe how streams of water descend from the higher to the lower parts. In some cases, a mechanical analogy also works well.

Stage III: Seeing known basic circuit principles
We continue our understanding of the circuit by trying to recognize in it components implementing some of the known basic circuit principles. To do this, we mark (for example, circle) and label the groups of circuit sub-devices and elements corresponding to the generalized elements of the block diagram that represents the corresponding principle. We draw the block diagram and make the connection with the corresponding elements of the specific circuit diagram.

Stage IV: Looking for a similar idea in other circuits and life situations
If we cannot see a basic circuit principle (from the collection of principles), we start looking for similar features in the operation (behavior) of other electronic circuits. For this we need to process a sufficient number of circuits. Each finding of similarity strengthens our confidence in the existence of a common universal principle.

If we cannot find similar ideas in electronic circuits, we start looking for similarity in different life situations (analogies).

Stage V. Summarizing the results into a new principle
If we cannot find a basic circuit engineering principle, then we try to formulate a new one by summarizing the results of the research (it is essential not only to understand how the particular circuit works, but also to expand the set of tools for understanding new electronic circuits):

 * 1) Try to find commonalities in the operation of the investigated device and other already known electronic devices.
 * 2) Look for commonality in the action of this set of electronic devices and life analogies from the surrounding reality.
 * 3) Summarize the observations in another principle and add it to the collection of principles for building electronic circuits.
 * 4) Draw the block diagram of the device that implements the principle and add it to the collection of block diagrams of devices.

EXAMPLE. Here is how we might find and derive a basic circuit principle in the example inverting summer circuit. In the operation of this and other similar inverting circuits (active current-voltage converter, inverting amplifier, integrator, differentiator, logarithmic converter and anti-logarithmic converter, etc.) we can observe the same strange phenomenon: the voltage drop VE2 across the element acting as a current-voltage converter, is harmful for the input source, but at the same time, it is useful for the load because it is actually the output quantity of the circuit (Fig. 4). It turns out that the VE2 voltage is necessary and useful but it is destroyed! Thus we observe an apparently absurd technical contradiction - the voltage drop VR must simultaneously exist and not exist!

We note that this problem is solved elegantly, as the operational amplifier destroys the "harmful" (with respect to the input sources) voltage VR, helping the input source with the additional voltage VH = VR (Fig . 5)

Web resources
Op-amp inverting summer builds the circuit by using the simpler passive voltage summer, voltage-to-current and current-to-voltage converters (Flash animated; Ruffle plugin is needed).

title: Circuit Idea/How to Understand Circuits


text: Culinary Arts/Beverage

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Culinary Arts/Beverage


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Exercise as it relates to Disease/Does being happy lead to a more active lifestyle?

What is the background to this research?
Physical activity is something that everyone should do, regardless of fitness levels as it keeps people healthy. Obesity rates are climbing at a fast and dangerous rate. Physical activity guidelines state for Adults (18–64 years old) should be accumulating 150 to 300 minutes of moderate intensity physical activity or 75 to 150 minutes of vigorous physical activity. This includes 2 strengthening activities on at least 2 days a week. If these outcomes can not be achieved doing any form of physical activity is still better than nothing. This study is designed to investigate the influence if peoples emotions determine whether emotions will dictate exercise and engagement in physical activity. Individuals intention are tested with the ‘Theory of Planned Behaviour’ (TPB). These predictors include intention to exercise, social norms and self-efficacy.

Where is the research from?
The research was conducted at the Department of Communications and Theater Arts at John Carroll University Amherst, New Your USA and assisted by Department of Communications, State university of New York, Buffalo U.S.A. This was published by Science Direct Volume 14, Issue 2. The theory of Planned Behavior was invented by Icek Ajzen. It is derived from a number of previous studies which engage in health behaviors The theory has been interpreted and guided by three considerations
 * 1) Attitude
 * 2) Subjective Norms
 * 3) Perceived Behavioral Control

What kind of research was this?
The research data was collected through an experimental randomised survey on Theory of Planned Behaviour. It was conducted with sophomores and juniors. The nature of this study was to observe if happiness encourages exercise, as well as seeing if a negatively impacted attitude reduces the idea or desire to exercise.

What did the research involve?
The hypothesis was tested through a collection of experimental surveys of 153 college students all in a large university. All participants were located upstate in New York in autumn 2011 with all the participants being undergraduate students. All the participants were randomly assigned to one experimental condition which were split into 3 categories:
 * 1) Neutral - Documentary on 'In Site Mind of Google'
 * 2) Positive - Video clips from 'Funniest Home Videos'
 * 3) Negative – Movie clip from ‘Marly and Me’ where the pet dog dies

Each video length was 10 minutes. Each participant was asked to complete a survey about exercise after the video. A manipulation check was embedded at the beginning of the questionnaire. The questionnaire contained measurable of the Theory pf Planed Behavior with other variables and control variables. This entirety took 20 to 30 minutes to complete. The participants were asked to indicate on a scale of 0 – 10 of they believed that exercise was
 * Good
 * Important
 * Wise
 * Valuable
 * Beneficial

10 items were used to measure affect, 4 being positive and 6 being negative. Positive affect items included happy, content, cheerful, and excited. Negative affect items included sad, upset, troubled, agitated, anxious, and stressed. These items were intended to capture a broad range of positive and negative emotions and were gathered from prior research

What were the basic results?
The results indicate that more than two thirds had reportedly exercised within the last 3 days, with 87.6% of all participants indicating that they had exercised within the last 10 days. With less than 5% of participants recording they rarely/never exercise. The participants reported that exercise was a part of a healthy lifestyle. All this is indicating that the sample had a very high baseline for exercise intentions already.

After the manipulation test, emotions such as sadness influenced their perception on exercise. Those who felt more negative affect might consider the idea the of exercising less favorable than they normally would.

This also means when decision making people consider the potential losses to a greater degree over potential gains. This is likely to be because negative information and positive information are processed differently. People use what is called heuristics to help make decisions in which negative information is presented and those outcomes are unfavorable. Therefore it is favored to be avoided more. It is quicker and easier to use mental shortcuts to make decisions, people rely one the notion that people should avoid potentially negative outcomes. The article does indicate that participants (especially in the neutral category) may already by happy, this exercising numbers were high Research has also shown that individuals weigh negative information more heavily than positive information when making decisions.

What conclusions can we take from this research?
Being happy does not necessarily makes people to being more incline to exercise. The study had indicated that a negative affect towards exercise plays a greater role in decreasing intentions to exercise. Exercise is generally associated with positive affect so this can influence someone’s decision to exercise. The participants in the neutral affect has remarkably similar results as the participants with positive affect. This may be due to these participants being generally happier, so the video did not alter any moods.

Practical advise
Exercising whilst with a positive attitude will make people feel more prone to exercise. Emotional influences such as sadness will affect any perception to exercise in a negative way. In comparison the positive participants may already have a clouded judgement through their own emotional experience. Overall living an active and healthy lifestyle increases general health and reducing risks of illness/diseases.

Further information/resources

 * Theories that explain emotions during exercise
 * Australian guidelines on Physical Activity
 * Additional reading on Theory of Planned Behaviour


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Exercise as it relates to Disease/Children’s overall fitness in relation to their exercise behaviour and body composition

This is an analysis of the journal article "Physical fitness of primary school children in relation to overweight prevalence and physical activity habits".

What is the background to this research?
Many research studies have shown the prevalence of overweight or obese children has risen progressively in not only South Western European Countries, but also worldwide. Italy ranks among the highest in relation to prevalence of excess weight in the age ranges 7–11 years and 13–17 years. It is a concerning trend that could see as many as 254 million children considered obese worldwide in 2030.

This particular research analysed the main conditioning and coordinative abilities in Italian children aged 8-9 years, and their relationship with anthropometric variables and physical activity habits. Evidently studies like these are important for understanding the imperative of getting children active, while potentiating the many positive impacts of consistent sport and physical activity participation.

Where is the research from?
The research was conducted in the Central Northern Province of Italy from a total of 521 students, all aged 8-9 years old in the third grade. There was 256 boys and 241 girls who participated in the study. Each of the researchers were a part of the Local Health Unit of Bologna in the Department of Public Health Italy and have a vast experience in the public health field.

What kind of research was this?

The study was cross sectional - a type of observational study whereby the investigator measures the outcome and the exposures in the study participants at the same time.

These studies are fast, inexpensive and don't require participants based on the outcome status (case control) or the exposure status (cohort). They have also been shown to be a useful tool for public health planning, monitoring and evaluation. Other study designs however have been better shown to highlight causal relationships - simply when one event causes another. There are also studies such as systematic reviews and meta analyses that obtain evidence from a range of papers to yield overall conclusions.

This means that the evidence in cross sectional studies like this one does vary and the strength of evidence presented is weaker than most other study designs.

What did the research involve?
The research was extensive and required each participant to perform three different assessments.

1. Physical Activity Questionnaire

Firstly, participants were required to undertake a self-administered physical activity questionnaire to collect general variables regarding their physical activity and sport participation habits in different settings and times of the day. By virtue of the questionnaire being self-administered, accuracy and validity can be compromised as most individuals tend to overestimate their physical activity levels.

2. Anthropometric Assessment (body composition)

Following the physical activity questionnaire, each participant had their height and weight measured to provide a measurement for body mass index (BMI). Despite the lack of consensus on the use of BMI in growing children, this index represents one of the most appropriate methods to assess adiposity in childhood and it is largely used at an international level. There is conflicting research, particularly in young boys that suggests BMI is not feasible as many boys gain weight in the form of muscle rather than fat.

3. Physical Fitness Assessment

Finally, participants completed a range of physical assessments targeting all components of fitness to get a holistic interpretation of their overall physical fitness levels. The tests included in the study were the standing long jump, 2kg medicine ball throw, 20 metre dash, sit and reach and forward roll.

What were the basic results?

Each of the relationships (sport participation, physical activity levels and body composition) and their impact on the fitness testing results are summarised below.

Sport Participation

The fitness testing results and their relationship with the self-reported physical activity questionnaire were anticipated. In general, those who reported regular sport participation had a better overall fitness base than those who did not, especially among boys.

Physical Activity Levels

Those who reported to live moderate to moderately active lifestyles performed superior to those who reported as either sedentary or very sedentary. Significant statistical differences were seen in the long jump, 20 metre dash and medicine ball throw tests.

Body Composition

In relation to body composition, the children categorised in the normal weight category outperformed the overweight and obese children in all tests apart from the 2kg medicine ball throw. Statistically significant differences were seen in the 20-metre dash and the standing long jump, arguably the most physically demanding tests undertaken. The relationship between body composition and physical fitness is tabulated above.

What conclusions should be taken away from this research?
The study is consistent with similar research and reveals that children who can retain consistent sport and exercise habits, while maintaining a healthy weight are fitter and therefore more physically competent.

Several conclusions can be drawn from what the research reveals, including:

1. As the obesity trend continues to increase worldwide, particularly in developed countries, the use of fitness tests which are easy to apply in any school context should be implemented. This will be important within primary schools as a means to identify pupils with a low fitness level and to promote a healthy lifestyle.

2. The need for enforced statutory requirements to meet guidelines and encourage children’s physical activity and education is apparent across the world. Physical education should be prioritised equally with STEM subjects and by creating regular opportunities for physical activity participation in schools, children can stay active and create vital exercise habits into adulthood. Accessibility to positive physical activity experiences is essential as it is well known that if children are able to positively associate with physical activity from a young age, sound exercise habits can be maintained throughout the lifespan.

3. Future research will need to utilise more accurate ‘gold standard’ measures (i.e. skinfolds, DEXA scan) to get a more precise representation of the relationship between body composition and physical fitness. The use of pedometers and other implements to measure physical activity habits should also be considered to remove any personal biases that arise from self reported methods.

Practical advice
The study highlights that the obesity trend is worsening, meaning it is paramount to get children involved in physical activity from a young age to promote weight control and sound exercise habits moving into adulthood. The amount of children participating in physical activity is largely dependent on parental influence and the emphasis of physical activity and education in schools.

This connotes that both parties, along with sporting organisations need to be collaborative and provide children with ample opportunity to get physically educated and stay active. Failure to do this will result in a continually worsening obesity trend that will eventually increase the amount of premature mortality's and costs arising from physical inactivity.


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User:RolfSander

Rolf Sander

title: User:RolfSander


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User:Mtmazhambe/Collections/The Greek Mythology

The Different Stories and Myths

 * Greek Mythology
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Exercise as it relates to Disease/Can lowering inflammation through exercise be used as an effective treatment for depression?

This article examines the impact exercise intensity has on mitigating depressive symptoms by reducing inflammation

Key Terms:
 * Tumor Necrosis Factor-α (TNF-α)
 * Interleukin 6 (IL-6)
 * High Intensity Training (HIT)
 * Moderate Intensity Training (MCT)
 * Non-exercise Group or Control (CON)

What is the background to this research?
This study examines whether exercise intensity effects the efficacy of exercise intervention in reducing depressive symptoms by lowering inflammation in non-clinical populations. Specifically, the research assesses cytokine activity in exercised student sample groups and concludes that moderate intensity continuous exercise is more effective at reducing inflammation caused by depressive symptoms than high-intensity. While there is a significant amount of research studying the positive impact that regular exercise has on negative mood states including depression and anxiety in clinical populations, this study fills a gap in the literature by using exercise intensity as an independent variable and makes an important contribution to the research regarding the prescription of exercise intervention to achieve better mental health outcomes.

Where is the research from?
The research was conducted at McMaster University, all four authors are reputable academics. Two of the authors, Emily M Paolucci and Jennifer J. Heisz have published a number of dissertations in the fields of health science, kinesiology, neurological and mental health. The authors Dessi Loukov and Dawn M.E Bowdish are experienced pathologists and their research is mainly in the field of molecular medicine.

What kind of research was this?
This study is a randomised control trial (RCT). RCTs are widely considered to produce the highest evidentiary level on the efficacy of healthcare interventions.

What did the research involve?
The study involved a six-week exercise intervention program and measuring its effects on pro-inflammatory cytokines and mood disorders. The study participants were sixty-one adult university students from McMaster University between 18-30 years old (72% Female).

Participants were randomised into three groups, all of them completed 18 bouts of exercise;

 * 1) High-Intensity-Interval-Training(HIT) group (18 Students; 72% females);
 * 2) Moderate-Intensity-Continuous-Training(MCT) group (19 students; 68% female);;
 * 3) Non-Exercise/Control(CON) group(18 students; 72% females).

Limitations from the research design methodology;

Firstly, the study relies on the assumption that there is an inverse causal relationship between inflammation and the development of depression symptoms.

Secondly, the authors selected a small sample group with a high gender bias (female) comprised of individuals from student populations (not representative or randomised), none of whom suffer clinical mood disorders. Problematically, the researchers purport to generalise conclusions from the subject group data to the general population, without clearly stating the relationship between the sample group and the general population or highlighting any obvious difficulties in extrapolating the results more broadly.

Thirdly, the study measured the participants’ mental health and assessed particular symptoms of depression and anxiety using the Beck Depression Inventory II & Beck Anxiety Inventory respectively. However, because both inventories, which consists of 21 self-rating items, are, crucially, designed to assess the severity of a particular symptom of depression and anxiety in clinical populations, they may not be suitable to assess nuanced psychological changes in a healthy population sample.

Finally, the experiment showed outcome biases as it only examined four pro-inflammatory cytokines related to inflammation and depression. The study also failed to test hormones released during exercise that may impact inflammation and depression.

What were the basic results?
According to these results TNF-α significantly decreased following MCT compared with CON, However TNF-α did not differ significantly between CON to HIT. IL-6 drastically increased post exercise relative to CON and MCT, however comparing CON to MCT there were only minor changes in IL-6. IL-6 and TNF-α were relatively higher in the CON group, therefore it can be said according to this table that both TNF-α will decrease more post MCT bouts, whereas IL-6 will increase post HIT relative to MCT. The finding also emphasised that when IL-6 is released via skeletal muscle it will have an anti-inflammatory response. In non-exercised individuals showing depression had elevated IL-6 levels which had mainly pro-inflammatory properties.

TABLE 1
The CON group recorded unusually high levels of stress which led to more depressive symptoms throughout the six-weeks. Pro-inflammatory cytokines such as TNF-α and IL-6 were elevated in the CON group in comparison to the MCT and HIT, however TNF-α did not decrease as meaningfully in the HIT group relative to the MCT group. The researchers attributed this high perceived stress that can be associated with high intensity styles of exercise. The article suggested that moderate-intensity-training may be optimal in reducing stress, inflammation and thus decreasing depressive symptoms as lowering TNF-α was accepted as producing better mental health outcomes. The article mainly focuses on elevated levels of pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β in depressed individuals, most competing articles would agree however some suggest there are no changes in IL-6 when comparing peoples who are depressed and healthy.

For example, in contrast with the authors’ results, The National Centre for Biotechnology Information (NCBI) conducted similar research using exercise intervention which showed a decrease in pro-inflammatory cytokines such as IL-6 in depressed patients. The study's results displayed in Table two, indicated that pro-inflammatory IL-6 levels were inconsistent in the patients displaying depressive moods, and reported no difference in relation to IL-6 levels in their healthy patients. The NCBI study goes on to suggest that evidence supporting the proposition IL-6 is casually related to depression remains inconsistent, as far too many studies have generated quantitative results opposing this conclusion.

What conclusions can we take from this research?
Most scientific literature supports the proposition that exercise programs in general are effective at lowering pro-inflammatory cytokines and in turn contribute to a reduction in depressive symptoms, however evidence regarding the optimal exercise intensity remains equivocal. In addition to the methodological limitations, the researchers fail to account for other physiological factors that reduce cytokines when exercising, such as the release of endorphins. Relevantly, a study conducted by the Journal of Affective Disorders conducted a similar experiment over six weeks and also measured β-endorphins levels amongst three test groups;(1) HIT exercisers;(2) MCT exercisers and a control group. The researchers found β-endorphin levels were highest in the post HIT exercisers relative to the MCT exercisers, and concluded that low to moderate exercise did not yield an endorphin release.

The study concluded that the patients subject to high intensity bouts of exercise had the highest reduction in depressive symptoms as well. The study used the Hamilton Depression Rating Scale (HAM-D), which saw a 77% reduction from baseline for the HIT exercisers compared to the MCT group that experienced a 65% decrease.

Notwithstanding the limitations outlined above, this study is important in encouraging further research into the possible impact of exercise intensity on mental health outcomes. It is recommended that researchers should design longitudinal studies with larger randomised sample groups to produce more reliable data on the efficacy of exercise on psychological well-being over time.

Practical advice

 * Start with simple exercise like walking or jogging
 * Do what is enjoyable; team sports, exercise with friends, plan activities
 * Stick to a routine
 * Track your mood response to different intensity workouts
 * Consult a doctor first
 * Complete an APSS form prior to exercising.

Further information/resources

 * Beyond blue - https://www.beyondblue.org.au/
 * Black Dog institute - https://www.blackdoginstitute.org.au/
 * Head Space - https://headspace.org.au/
 * ESSA (free Exercise and Mental Health ebook) https://exerciseright.com.au


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Exercise as it relates to Disease/Exploring strategies that influence children's physical activity self-efficacy

This is a critique of the research article by Merav Efrat: Exploring Strategies That Influence Children’s Physical Activity, from the contemporary issues in education research journal. This was written as an assignment for the unit Health, Disease and exercise at the University of Canberra.

What is the background to this research
Those who meet the physical activity guidelines during childhood are more likely to continue to meet them throughout adulthood, reducing the likelihood of morbidity and premature mortality. Despite this, only 24% of children aged 6 to 17 years in American schools meet the recommended guidelines. Interventions to improve habitual physical activity participation are necessary for long term adherence. Lack of equipment, minimal free time and poor socioeconomic status present barriers to physical activity in children. Unstructured recreational time (recess/lunch) provides an opportunity to acquire physical activity hours, however, only 33% of boys and 25% of girls spend recess time in moderate to vigorous physical activity.

Physical activity self efficacy (PASA), or the judgements of one's capability to accomplish a certain level of performance, is a strong predictor of school aged physical activity participation. Therefore, interventions should promote methods to enhance PASA through competent adult models (class time education on ways to be more active), and teacher encouragement. The purpose of this study is to compare if teachers encouragement alone, or modelling by a competent adult alone will have a similar impact on children's recess time physical activity self efficacy (RTPASE).

Where is the research from
The author of this study is Merav Efrat, who is an Associate Professor in the Department of Health Science at Cal State University, in North Ridge. She is a reputable researcher in the field of obesity and physical activity in children. This study is a followup to one she conducted in 2013, that used the same interventions, however measured MVPA levels during recess using accelerometer data, finding teachers encouragement more effective than adult modelling. The similarity between the two studies raises the question that do PASA increases matter independent of accelorometer measured behavioral changes. This followup study could be redundant, as she has already conducted a similar study showing objectivly measured increases in MVPA with identical interventions.

What kind of research was this
This study is a cluster randomized controlled trial, where predetermined groups are randomly presccribed an intervention, as opposed to individuals being randomly assigned to a group.

What did the research involve
The fourth grade cohort of three similar suburban Californian schools were each assigned a different intervention -Students were taught active recess games during six of their PE classes -A brief message to the students delivered before recess/lunch encouraging active choices - No intervention
 * Adult modelling (51 students)
 * Teachers encouragement (59 students)
 * Comparison (51 students)

By performing the study as a cluster randomised controlled trial, contamination of data through individuals of different groups interacting is minimised. Change to student lifestyle is also reduced, minisming undesirable behaivor changes. Differences in the schools, however, may impact the results and lead to correlative, but not causative data. Environmental differences (playground equipment, walking tracks, sport facilities), variation in teachers enthusiasm for physical activity, and prior recess time interventions are not accounted for in the data. Specifically, it was stated in the study that the teacher encouragement group already had an intervention in place to encourage students to be more active at recess. Therefore, it is unknown if the results obtained from this study could be replicated in a group without the prior intervention. The study is also only reflective of three schools in a similar region with similar characteristics. To improve the validity of this study, more schools should have been chosen with varying characteristics (teachers enthusiasm, other in place internvetions, environmental differences) and included urban and rural elementary schools to give greater data on factors influencing PASA across America.

Recess time physical activity self efficacy baseline data was collected using a questionnaire from a previously published study. The questionnaire used a 5 point scale from 1 (not confident) to 5 (definitely confident). This provided information on task self efficacy (level of confidence engaging in light, moderate and vigorous levels of PA) and adult encouragement self efficacy (confidence in engaging in PA even if an adult does not encourage them). Other measured barriers include confidence in overcoming personal, social and environmental barriers to physical activity. Practical techniques and demonstrations were implemented to ensure the children understood the questionnaire procedure. Pre and post treatment scores on this questionnaire are then compared across the interventions for this study.

What were the basic results
Encouragement from teachers was more effective at improving RTPASE scores (see figure 1). Children may internalize the encouragement, becoming less reliant on external motivation. The control group shows greater RTPASE scores compared to the adult modelling group, which had the lowest scores. These results are similar to the prior study conducted by Efrat, which found that encouragement was the most effective, and adult modelling least effective, at increasing recess time physical activity levels measured by accelerometer data.

What conclusions can we take from this research
According to this study, PASA sees greatest improvements with teacher encouragement when compared to adult modelling. This implies that a brief message to make active choices before recess is more effective than classtime education on physical activity behavior. Methodologies of the study, however, question the validity of this finding, mainly being that a prior intervention introduced by the school with the teacher encouragement group was not accounted for in the results. Therefore it is unclear if teachers encouragement on its own would yield similar results. Moreover, adult modelling has been shown to be effective, especially when done in the context of when the child will be active, rather than in class. Therefore, the lower scoring of adult modelling in this study is more reflective of weaknesses in the study rather than the intervention.

Further studies should investigate similar interventions, however across more schools in different regions. Other factors such as the influence of season (weather changes), organised sport activities, and the impact other adults such as principles and coaches may have, and how these factors can be manipulated, should be investigated.

Practical advice
Teachers encouragement is an effective strategy for increasing physical activity during recess at school by improving children's confidence in their ability to participate in activity, as demonstrated by this study. A brief, motivating statement right before recess and lunch can allow children to acquire more PA time. Education on physical activity in class, including ways to be more active during recess and lunch can also motivate students to be more active.Modifications to the environment and playground equipment to increase opportunities for physical activity can also be implemented. By improving physical activity self efficacy, long term adherence may increase through to adulthood based on the habits developed in early childhood.


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Circuit Idea/How to Create a Circuit Story for this Book

<<< Circuit Idea Discussion - How to Contribute to Circuit Idea - page stage >>>

How to Create a Circuit Story for this Book

Requirements
Circuit Idea is not an ordinary electronics book where particular circuits are described. It is a book about the ideas behind circuits. So there must be some idea in the circuit that you decide to consider on the new page... and you have to reveal it.

Technology
Here is a typical building scenario for creating a circuit story:

1. Posing the problem to be solved (improving a passive circuit, solving a circuit contradiction, etc.)

2. Revealing the basic idea in the non-electrical domain (looking for analogies, deriving a block-diagram and operation algorithm).

3. Applying the general idea in the electricity domain (building an equivalent and "man-controlled" electrical circuit).

4. Showing the passive circuit applications (building standalone and composite passive devices).

5. Revealing the passive circuit imperfections (revealing and evaluating inherent circuit deficiencies).

6. Improving the imperfect passive circuit and creating a perfect active version (converting the passive circuit into an active one).

7. Applying the idea in the electronics domain (building various active devices based on the same idea).


text:
User:JMPHOTOS

LIFE'S A JOURNEY..

title: User:JMPHOTOS


text:
World Stamp Catalogue/Switzerland

=The Swiss tax system= Taxation in Switzerland has different levels. Taxes are levied by the Swiss confederation, the 26 cantons and the municipalities. The federal and cantonal constitutions govern the delimitation of Swiss taxation powers. However, the cantons exercise all the rights of a sovereign state. They can levy any type of tax as long as the Federal Constitution does not reserve a right for the national government to do so.

There are only a few types of Swiss taxes for which the confederation claims exclusive taxation authority. These include: Swiss VAT, stamp duties, withholding tax, custom duties and special consumption taxes. Consequently, the cantons have wide latitude in the creation of their own tax legislation. Municipalities may only levy taxes with authorization by the constitution of their respective canton.

In addition, the parishes of the three national churches (Christian Catholic, Protestant, and Roman Catholic) levy a church tax on their members in almost all cantons. This also applies to the legal entities liable for tax in the canton.

The levels of Swiss tax authorities are:
 * Federal level: governed by the Federal Constitution
 * Cantonal level: governed by the canton
 * Municipal level: governed by the commune.
 * Church: members of the three national churches are taxed in almost all cantons.

=Federal revenue stamps of Switzerland= Switzerland, officially the Swiss Confederation, is a federal republic in Europe. It consists of cantons, and the city of Bern is the seat of the federal authorities. Federal revenue stamps were issued for 14 different taxes between 1915 and 1980.

1915
Design by Hans Frei (1868 - 1947), Swiss medallist, goldsmith and sculptor.

1915
1915 federal bonds and notes stamps overprinted in black 'Service Consulaire Taxes'.

1918
Arms of Switzerland. 5c-50c grey-brown, 1fr-100fr lilac on yellow. Red value inscription. perforated 11.75, unwatermarked. Granite paper with red colored silk fibers (A). Different types can be distinguished for 1fr, 2fr and 5fr.
 * A: Granite paper with red colored silk fibers. Unwatermarked. 1fr, 2fr and 5 fr. (1918)
 * B: Granite paper with red and blue colored silk fibers. Unwatermarked. 1fr, 2fr and 5 fr. (1918)
 * C: Ribbed granite paper with red and blue colored silk fibers. Watermarked large cross. 1fr and 2fr. (1933)

1920-1933
Arms of Switzerland, 5c-50c. Orange-brown, perforated 11.75. Three types can be distinguished.
 * A: Granite paper with red colored silk fibers. Unwatermarked. (1920)
 * B: Granite paper with red and blue colored silk fibers. Unwatermarked. (1920)
 * C: Ribbed granite paper with red and blue colored silk fibers. Watermarked large cross. (1933)

1920

Confederation
Relief imprint. Design by Hans Frei (1868 - 1947), Swiss medallist, goldsmith and sculptor. 5 different fees were applied for different purposes. Little is known about this group except some different dates per tax. Bonds were taxed 3% (№ 5).

=Cantonal revenue stamps= The 26 cantons of Switzerland are the member states of the Swiss Confederation.

Aargau
Aargau is one of the 26 cantons of Switzerland. 48 different revenue stamps were issued from 1886 to 1936. 50 different special issues are known, all imperforate.

1886
Coat of arms of Aarau. Three types can be distinguished:
 * A: Imperforate
 * B: Perforated 11.5, light colors
 * C: Perforated 11.5, dark colors

Poster tax
1916. 5 different values with perforations 10 (A), 10.75-11 (B), 11-11.25 (C) or 11.5 (D).

Markings
Two different categories of revenue markings can be distinguished:
 * Hand stamps (A),
 * Relief (dry) marking (C), from ca. 1825.

Basel
See separate book: Basel

Bern
See separate book: Bern

Fribourg
See separate book: Fribourg

Geneva
See separate book: Geneva

Grisons
Grisons or Graubünden, is the largest and easternmost canton of Switzerland. 15 different revenue stamps were issued from 1930 to 1947 and for tourism 39 from 1936 to 1957.

General revenue, 1943
Perforated 11 (A) or 11.5 (B)

Tourism
The tourism tax stamps of Switzerland deal with the stamps related to the short-term, visitor-accommodation tourism taxes (taxe de séjour). The tourism tax is a public contribution that the guest of a resort or region must pay to help finance the expenses for improving the conditions of their stay. 4 different sets were issued by the canton of Grisons between 1936 and 1957.

1936-1938
Arms of Grisons. Two perforations: 11 (A) or 11.5 (B). The 5c exists in three types: wide (x), 7 narrow 5 (y), cutoff 5 (z).
 * One line surrounds shield
 * Oval whorls
 * Upper right field of shield is correct
 * Condensed numeral field
 * Lower right whorl has no dot in the oval.

1944
Arms of Grisons. Perforated 11.5.
 * Two lines surround shield
 * Round whorls
 * Shading in shield is incorrect
 * Condensed numeral field
 * Lower right whorl has a dot in the oval.

1944-
Arms of Grisons. Perforated 10.75 thick paper (A), 10.75 thin paper (B) or 11.5 (C)
 * Two lines surround shield
 * Round whorls
 * Upper right field of shield corrected
 * Spread numeral field
 * Lower left whorl resembles snake head.

Lucerne
See separate book:Lucerne.

Neuchâtel
See separate book: Neuchâtel

Uri
Uri is one of the 26 cantons of Switzerland and a founding member of the Swiss Confederation, located in Central Switzerland. 25 different revenue stamps were issued from 1895 to 1947. 2 special stamps were issued in 1894 and 2 in 1895.

General revenue, 1895
Perforated 12.75.

Zug
The canton of Zug, also Zoug is one of the 26 cantons of Switzerland. It is located in central Switzerland and its capital is Zug. Zug is one of the smallest of the Swiss cantons in terms of area and is subdivided into eleven municipalities. 7 different revenue stamps were issued from 1888 to 1943. 2 tourist tax stamps were issued in 1959 and 3 essays are known.

General revenue, 1888-1909
Arms of Zug. The first issue can be divided in 4 groups: Perforated 10.75 (A), 11.5 (B), 12.75 thick paper (C), 12.75 thin paper (D). Numerous shades.

=Municipal revenue stamps= The municipalities of Switzerland are the lowest level of administrative division in Switzerland. Each municipality is part of one of the Swiss cantons, which form the Swiss Confederation. In most cantons municipalities are also part of districts or other sub-cantonal administrative divisions. There are 2,294 municipalities in 2017, and according Gainon about 800 have issued revenue stamps.

Aarau (AG)
Aarau is the capital of the canton of Aargau. 28 different stamps were issued between 1906 and 1908. 9 special printings (S) exist.

Aarberg (BE)
Aarberg is a municipality in the Canton of Berne. 4 different stamps were issued in 1904, perforated 11.5 (A) or 14 (B). Next to these issues 28 special printings (S) exist imperforate (A), perforated 11.5 (B,C) or 14 (D).

L'Abbaye (VD)
L'Abbaye is a municipality in the canton of Vaud. 4 different stamps were issued.

Adlisweil (ZH)
Adlisweil or Adliswil is is a town and a municipality in the district of Horgen in the canton of Zürich. 24 different stamps were issued between 1906 and 1948.

Albligen (BE)
Albligen (former French name: Albenon) is a former municipality in the Bern-Mittelland administrative district in the canton of Bern in Switzerland. 4 different stamps were issued between 1910 and 1913.

Amriswil (TG)
Amriswil is a town and a municipality in Arbon District in the canton of Thurgau. 44 different stamps were issued between 1907 and 1970.

Arbon (TG)
Arbon is a municipality and district capital of the district of Arbon in the canton of Thurgau. 33 different stamps were issued between 1908 and 1970.

Bellinzona (TI)
Bellinzona is the capital of the canton Ticino. 12 different stamps were issued between 1910 and 1962.

Biasca (TI)
Biasca is a town of the district of Riviera in the canton of Ticino. 7 different stamps were issued up to 1963.

Biel / Bienne (BE)
Biel/Bienne is a town and a municipality in the Biel/Bienne administrative district in the canton of Berne. 88 different stamps were issued between 1892 and 1935.

1902-1910
Schriften-Controlle, perforated 11.5. or 13.25 (1910 - B). 5 types can be distinguished of the 1902 issue, based on small line deformations in the lower half of the stamp.

1919
Schriften-Kontrolle, perforated 11.5.

Police
1918-1931. Polizei-Commissariat, perforated 11.5.

City of Biel
1919-1921.

Bremgarten (AG)
Bremgarten is a municipality in the Canton of Aargau. 29 different stamps were issued between 1905 and 1940.

Brig-Glis (VS)
Brig-Glis is a historic town and a municipality in the district of Brig in the canton of Valais. 6 different stamps were issued in the 1930's, perforated 11.25 (A) or 13 (B) or 13x11.25 (C).

Brügg (BE)
Brügg is a municipality in the Biel/Bienne administrative district in the canton of Bern. 12 different stamps were issued between 1907 and 1935.

Burgdorf (BE)
Burgdorf is the largest city in Emmental in the canton of Bern. 12 different stamps were issued in 1917. Four different perforations exist: 11.25x11.5 (A), 13 (B), 11.25x13 (C) and imperforate (D).

Cadenazzo (TI)
Cadenazzo is a municipality in the district of Bellinzona, in the canton of Ticino. 5 different stamps were issued.

Castagnola (TI)
Castagnola is a village on the northern shore of Lake Lugano, below the mountain of Monte Brè, in the Swiss canton of Ticino. Now a quarter of the city of Lugano. Until 1972 an independent municipality. 15 different stamps were issued from 1905.

Chaux-de-Fonds, La (NE)
La Chaux-de-Fonds is a municipality in the canton of Neuchâtel. 60 different revenue stamps were issued from 1889.

Chenit, Le (VD)
Le Chenit is a municipality in the canton of Vaud. 2 different entertainment tax stamps were issued in 1938.

Corgémont (BE)
Corgémont is a municipality in the Jura bernois administrative district in the canton of Bern. 17 different stamps were issued.

Courrendlin (JU)
Courrendlin is a municipality in the district of Delémont in the canton of Jura. 10 different stamps were issued between 1901 and 1925.

Court (BE)
Court is a municipality in the Jura bernois administrative district in the canton of Bern. 6 different stamps were issued in the 1900's.

Crissier (VD)
Crissier is a municipality in the district of Ouest Lausannois in the canton of Vaud. 11 different stamps were issued between 1905 and 1968. 3 special issues are known.

Cully (VD)
Cully is a former municipality in the Swiss canton of Vaud. 40 different stamps were issued from 1892. 7 special issues are known.

Delémont (JU)
Delémont is the capital of the Swiss canton of Jura. 44 different stamps were issued between 1904 and 1956.

Dornach (SO)
Dornach is a municipality in the district of Dorneck in the canton of Solothurn. 9 different stamps were issued.

Échallens (VD)
Échallens is a municipality in the district of Gros-de-Vaud in the canton of Vaud. 4 different entertainment tax stamps were issued.

Evilard (BE)
Evilard is a municipality in the Biel/Bienne administrative district in the canton of Bern. 14 different stamps were issued, perforated either 10 (A) or 11.5 (B).

Giubasco (TI)
Giubiasco is a municipality in the district of Bellinzona in the canton of Ticino. 14 different stamps were issued between 1945 and 1992.

Grenchen (SO)
Grenchen is a municipality in the district of Lebern in the canton of Solothurn. 47 different stamps were issued between 1919 and 1971.

1923
Arms of Gretchen. Four perforations exist: 11.25 (A), 11.5 (B), 13 (C) and 11.25x13 (D).

Grüningen (ZH)
Grüningen is a village in the district of Hinwil in the canton of Zürich. 18 different stamps were issued between 1932 and 1953.

Guggisberg (BE)
Guggisberg is a municipality in the Bern-Mittelland administrative district in the Swiss canton of Bern. 7 different stamps were issued in 1908 and 2 tourism tax stamps.

Herisau (AR)
Herisau is a municipality in the canton of Appenzell Ausserrhoden. 33 different stamps were issued between 1889 and 1960.

Horgen (ZH)
Horgen is a municipality in the district of Horgen in the canton of Zürich. 34 different stamps were issued between 1909 and 1936.

Huttwil (BE)
Huttwil is a municipality in the Oberaargau administrative district in the Swiss canton of Bern. 29 different stamps were issued from 1903.

Interlaken (BE)
Interlaken is a statistic town and municipality in the Interlaken-Oberhasli administrative district in the Canton of Bern. 31 different stamps were issued between 1926 and 1933. Variations exist, some can be distinguished by measuring the distance between value numeral and 'Cts' or 'Fr'.

Kilchberg (ZH)
Kilchberg is a municipality in the district of Horgen in the canton of Zürich. 32 different stamps were issued between c. 1916 and 1952.

Köniz (BE)
Köniz is a statistical town, however considers itself still as a village, and a municipality in the Bern-Mittelland administrative district right on the southern border to Bern in the canton of Bern. 43 different stamps were issued from 1901.

Kreuzlingen (TG)
Kreuzlingen is a municipality in the district of Kreuzlingen in the canton of Thurgau. 33 different stamps were issued between 1908 and 1980. One tourism revenue stamp was also issued.

Küsnacht (ZH)
Küsnacht is a municipality in the district of Meilen in the canton of Zurich. 8 different stamps were issued in 1901.

Langenthal (BE)
Langenthal is a town and a municipality in the district of Oberaargau in the canton of Bern. 36 different stamps were issued between 1907 and 1950.

Laufen / Laufon (BE, 1994: BL)
Laufen is a municipality and the capital of the district of Laufen in the canton of Basel-Country. 7 different stamps were issued in 1908, perforated either 11 (A) or 11.5 (B).

Lausanne (VD)
Lausanne is the capital and largest city of the canton of Vaud. 103 different stamps were issued between 1878 and 1950.

Lieu, Le (VD)
Le Lieu is a municipality in the canton of Vaud. 4 different stamps were issued in c. 1930.

Locle, Le (NE)
Le Locle is a municipality in the Le Locle District in the Canton of Neuchâtel. 22 different stamps were issued between 1892 and 1950.

Lugano (TI)
Lugano is a city in southern Switzerland in the Italian-speaking canton of Ticino. 21 different stamps were issued between 1893 and 1931.

Lützelflüh (BE)
Lützelflüh is a municipality in the administrative district of Emmental in the Swiss canton of Bern. 15 different stamps were issued between 1904 and 1957.

Madretsch (BE)
Madretsch is a former commune in the Swiss canton of Bern. Now a suburb of Biel/Bienne, which it joined in 1920. 5 different stamps were issued in 1903.

Mett (BE)
Mett is a former commune in the Swiss canton of Bern. Now a suburb of Biel/Bienne, which it joined in 1920. 5 different stamps were issued in 1916.

Monthey (VS)
Monthey is the capital of the district of Monthey in the canton of Valais. 17 different stamps were issued.

Montreux (VD)
Montreux is a municipality in the district of Riviera-Pays-d'Enhaut in the canton of Vaud. 18 different tourism tax stamps were issued.

Moutier (BE)
Moutier is a municipality in the Jura bernois administrative district in the canton of Bern. 22 different tax stamps were issued between 1915 and 1945.

Muri (AG)
Muri, formerly known as Muri (Freiamt), is a municipality in southeastern Swiss Canton Aargau and is the capital of same district. 26 different tax stamps were issued.

Muttenz (BL)
Muttenz is a municipality in the canton of Basel-Country. 30 different tax stamps were issued from 1930.

Neuhausen am Rheinfall (SH)
Neuhausen am Rheinfall (which was called Neuhausen until 1938) is a municipality in the canton of Schaffhausen. 18 different tax stamps were issued from 1919 to 1947.

Neuveville, La (BE)
La Neuveville is a municipality in the Jura bernois administrative district in the canton of Bern. 8 different tax stamps were issued, dates are unknown.

Nidau (BE)
Nidau is a municipality in the Biel/Bienne administrative district in the canton of Bern. 19 different tax stamps were issued from 1910.

Niederbipp (BE)
Niederbipp is a municipality in the Oberaargau administrative district in the canton of Bern. 19 different tax stamps were issued to c. 1976.

Ollon (VD)
Ollon is a municipality in the district of Aigle in the canton of Vaud. 9 different tax stamps were issued from c. 1903.

Ponts-de-Martel, Les (NE)
Les Ponts-de-Martel is a municipality in the district of Le Locle in the canton of Neuchâtel. 14 different tax stamps were issued from 1892.

Rapperswil (SG)
Rapperswil is a former municipality and since January 2007 part of the municipality of Rapperswil-Jona in the Wahlkreis (constituency) of See-Gaster in the canton of St. Gallen. 47 different tax stamps were issued between 1917 and 1920. 1917 issue exists in white (A) and buff (B) paper.

Reconvilier (BE)
Reconvilier is a municipality in the Jura bernois administrative district in the canton of Bern. 9 different tax stamps were issued between 1904 and 1919.

Reinach (AG)
Reinach, Aargau is a municipality in the district of Kulm in the canton of Aargau. 8 different tax stamps were issued ca. 1925.

Renens (VD)
Renens is a municipality in the canton of Vaud. It is located in the district of Ouest Lausannois, and is a suburb of the city of Lausanne. It is the fourth largest city in the canton. 63 different tax stamps were issued between 1904 and the 1940's.

Non-firebrigade tax
'Taxe non-pompier', tax levied only at cantonal and municipal level. The non-fire brigade tax is not considered as being one of the 'taxes for particular services rendered' which, without exception, are to be paid by the beneficiaries of privileges and immunities. It is calculated on the taxpayer's income.

Riehen (BS)
Riehen is a municipality, in the canton of Basel-Stadt. 3 different tax stamps were issued around 1907.

Riggisberg (BE)
Riggisberg is a municipality in the Bern-Mittelland administrative district in the canton of Bern. 4 different tax stamps were issued in 1921.

Roggwil (BE)
Roggwil, Bern is a municipality in the Oberaargau administrative district in the canton of Bern. 34 different tax stamps were issued from 1916.

Rorschach (SG)
Rorschach, Switzerland is a municipality, in the canton of St. Gallen. 60 different tax stamps were issued from 1909 to 1956.

Rüti (ZH)
Rüti, Zürich is a municipality in the district of Hinwil in the canton of Zürich. 10 different tax stamps were issued in 1936.

Saanen (BE)
Saanen is a municipality in the canton of Berne. It is the capital of the Obersimmental-Saanen administrative district. 25 different tax stamps were issued, dates are unknown.

Sainte-Croix (VD)
Sainte-Croix is a municipality in the district of Jura-Nord Vaudois in the canton of Vaud. 5 different tax stamps were issued from 1894.

Saint-Imier (BE)
Saint-Imier is a municipality in the Jura bernois administrative district in the canton of Bern. It is located in the French-speaking Bernese Jura (Jura Bernois). Saint-Imier issued school revenues, unlisted in catalogues.

Saint-Maurice (VS)
Saint-Maurice, or 'Saint-Maurice d'Agaune', is a small city located in the canton of Valais. It is also the capital of the district and of the municipality of Saint-Maurice. 5 different tax stamps were issued.

La Sarraz (VD)
La Sarraz is a municipality of the canton of Vaud, located in the district of Morges. 3 different tax stamps were issued from 1904.

Schaffhausen City (SH)
Schaffhausen is a town with historic roots, a municipality in northern Switzerland, and the capital of the canton of the same name. 23 different tax stamps were issued from 1904.

Spiez (BE)
Spiez is a town and municipality on the shore of Lake Thun in the Bernese Oberland region of the Swiss canton of Bern. It is part of the Frutigen-Niedersimmental administrative district. 20 different tax stamps were issued.

Steffisburg (BE)
Steffisburg is a municipality in the administrative district of Thun in the canton of Bern. 18 different tax stamps were issued.

Sumiswald (BE)
Sumiswald is a municipality in the district of the Emmental administrative district in the canton of Bern. 49 different tax stamps were issued from 1902 to 1975.

Ca. 1916
Design in blue.

Tavannes (BE)
Tavannes is a municipality in the Jura bernois administrative district in the canton of Bern. 31 different tax stamps were issued.

Wädenswil (ZH)
Wädenswil is a municipality in the district of Horgen in the canton of Zürich. 53 different tax stamps were issued between 1887 and 1948.

=References=

title: World Stamp Catalogue/Switzerland