- Aug 2017
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within-subjects manipulations
Within-subjects manipulations refer to situations in experiments where the same person is assigned to multiple experimental conditions.
For example, let’s say we want to find out which of two different learning techniques (A and B) is more effective in helping students prepare for a vocabulary test. If we conducted a within-subjects manipulation, each student would apply both learning techniques.
Let’s say every student must first apply learning technique A, then take a vocabulary test, and then a week later for the next test apply learning technique B. We could now compare following which learning technique the students perform better.
In contrast, if we conducted a between-subjects manipulation, each student would only apply one learning technique. We would split the group of students, so that half of them use learning technique A and then take the vocabulary test, while the other students use learning technique B and then take the vocabulary test. Again, we could compare following which learning technique the students perform better.
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pre-analysis plans
A pre-analysis plan is a document that specifies which analyses will be run on the data, before these analyses are performed.
This plan can specify which variables and analyses will be used, how data will be prepared for analyses, and in which cases data will be excluded from analyses. This tool helps researchers specify and commit to the way they want to run the analyses in their study.
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confirmatory tests
A confirmatory test is a statistical analysis of a certain relationship which had previously been hypothesized to hold. The test tries to find out if the hypothesis is supported by the data.
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publication bias
Publication bias is a type of distortion that can occur in making academic research public. When findings which show that a certain effect of interest was found to be statistically significant are more likely to be published than findings which show no evidence or even evidence against this effect, publication bias is present.
In this case, if you only read the published papers, you would find a lot of papers showing support for an effect, while studies which do not show support for the same effect are not published, giving you the impression that the effect was less disputed and more consistently found than it actually is.
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fixed-effect model
A fixed effects model is a statistical model which accounts for individual differences in the data which cannot be measured by treating them as non-random, or “fixed” at the individual level.
As an example, let’s say we wanted to study if drinking coffee makes people are more likely to cross the street despite a red light. Our outcome variable of interest is how often each subject crosses a street despite a red light on a walk with 10 red traffic lights. The explanatory variable we manipulate for each participants is if they had a cup of coffee before the experiment or a glass of water (our control condition), and we would use this variable to try to explain ignoring red lights.
However, there are several other influences on ignoring red lights which we have not accounted for. Next to random and systematic error, we have also not accounted for individual characteristics of the person such as their previous experience with ignoring red lights. For instance, have the participants received a fine for this offense? If so, they might be less likely to walk across a red light in our experiment.
Using a fixed effects model makes it possible to account for these types of characteristics that rest within each individual participant. This, in turn, gives us a better estimate of the relationship between coffee drinking and crossing red lights, cleaned from other individual-level influences.
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Spearman’s rank-order correlations
Spearman’s rank-order correlation is a specific type of correlation analysis, which assess the relationship between two variables with regard to its strength and direction.
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multivariate interaction effects
A multivariate interaction effect is an effect that is the product of several variables working together and influencing each other.
For example, we might be interested in finding out how water temperature (warm: 38°C; cold: 15°C) affects the body temperature of humans and sea lions. We might find that humans, on average, have a higher body temperature than sea lions, and that body temperature is higher when the body is immersed into warm compared to cold water.
However, we might find that a human’s body temperature shows bigger differences between the warm and cold water conditions than the sea lion’s body temperature. Because sea lions have a substantive layer of protective fat, they body temperature does not change as much when water temperature changes, compared to humans.
Here, species and water temperature show an interaction effect on body temperature.
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sample size
The sample size refers to the number of people from whom data is collected in a study.
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accumulated evidence
Accumulated evidence refers to the results of several studies taken together.
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random or systematic error
There are two sources of error which can occur in scientific studies and distort their results.
Systematic errors are inaccuracies that can be reproduced. For example, imagine we wanted to measure a participant’s weight and we make our participant step on 5 different scales and measure her weight on each scale 10 times. Four scales report that she weighs of 74kg each time our participant steps on them. The last scale shows that she weighs 23kg each time the participant steps on it. We would say there is a systematic error involved in our study of her weight, because last scale consistently and erroneously reports her weight as too low.
Random errors are inaccuracies that occur because there are unknown influences in the environment. For example, imagine we wanted to measure a participant’s weight and had her step on the same scale 3 times in a row, within one minute. The first time, the scale reports 74,43kg, the second time 74,34kg, the third time 74,38kg. We don’t think that the participants’ weight has actually changed in this one minute, yet our measurement shows different results, which we would attribute to random errors.
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Correlational tests
A correlational test is a statistical method of analysis which asks if there is a relationship between two variables, and if this relationship is unlikely to be caused by chance.
For example, if we wonder if intelligence influences students’ biology exam performance, we could use a correlational test to see if more intelligent students get higher scores in a biology test. If we find this pattern, the test would also tell us if our result is extreme enough (if the correlation is strong enough) so that the probability that we make an error if we assume this relationship is true would be very low.
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- Jul 2017
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confidence intervals (CIs)
When studies are run, we aim at estimating values that are true for the population. However, we often cannot record data from everyone in the population, which is why we rely on drawing a random sample from the population. For example, while we may want to estimate the average difference in height between all men and all women in the world, we cannot possibly measure the height of all men and women in the world. Therefore, we draw a random sample of men and women. Let's say we collect data from 100 men and 100 women. The study reveals the average difference in height we find in this sample of 200 people, but it does not tell us what the true difference in height in the population of all men and women in the world is.
If we drew random samples of 200 people from the population of all men and women in the world again and again and again, and assessed their average difference in height each time, we would find a range of values. This range of values represents our estimates for the height difference in the population of all men and women in the world.
We refer to this range of values (interval) as the confidence interval. We want to make sure that it includes the true value of the variable we are estimating for the population sufficiently often. If we refer to a 95% Confidence Interval ('CI'), this means that our range of estimates from random samples contains the true value of the population in 95% of all cases.
If we calculate a CI from one study that we have run, it tells us the probability (e.g., 95%) that the CIs of repeated future samples would contain the true population value.
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cumulative process
The term “cumulative process” here refers to taking an approach to research in which we try to gain insight not by interpreting strongly the results of one individual study at a time, but by integrating the results of several studies and broader research programs to gain an overview of the overall evidence.
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validity
Validity refers to the degree to which a certain result or conclusion in research corresponds with reality. There are different aspects of a study which can improve or decrease its validity. For example, a study has high ecological validity if its results can be directly applied to real-life situations outside of the lab.
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narrow-and-deep approach
This refers to results of studies that go into detail on a specific area, without covering a wide range of different topics.
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broad-and-shallow evidence
This refers to results of studies that cover a wide range of different topics, without going into detail on a specific area.
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upwardly biased effect sizes
Here, upwardly biased means that the effect sizes reported in the literature are distorted to appear bigger than they really are.
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consistently
When results of several analyses point in the same direction, we say the results are consistent. For example, if we run three correlation analyses and find that enjoyment of hiking, self-assessed nature-lovingness, and number of times previously hiked all correlate positively with the probability that someone enjoys hiking holidays, we would say that the results are consistent. If we found that the number of times previously hiked was negatively correlated with the probability that someone enjoys hiking holidays, the results would be less consistent.
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pre-analysis plans
A pre-analysis plan is a document that specifies which analyses will be run on the data, before these analyses are performed. This plan can specify which variables and analyses will be used, how data will be prepared for analyses, and in which cases data will be excluded from analyses. This tool helps researchers specify and commit to the way they want to run the analyses in their study.
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confirmatory tests
A confirmatory test is a statistical analysis of a certain relationship which had previously been hypothesized to hold. The test tries to find out if the hypothesis is supported by the data.
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publication bias
Publication bias is a type of distortion that can occur in making academic research public. When findings which show that a certain effect of interest was found to be statistically significant are more likely to be published than findings which show no evidence or even evidence against this effect, publication bias is present. In this case, if you only read the published papers, you would find a lot of papers showing support for an effect, while studies which do not show support for the same effect are not published, giving you the impression that the effect was less disputed and more consistently found than it actually is.
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population effect size
The population effect size is the estimate of the strength of the effect in the population of all possible subjects (e.g., all humans).
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goodness-of-fit χ2 test
A goodness-of-fit test indicates how well a statistical model fits the data. It shows whether the difference between the observed data and the predicted, expected values is too big, or if the difference is small enough that we could assume the model captures reality sufficiently well. A goodness-of-fit χ2 (chi-squared) test is a specific type of goodness-of-fit tests.
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Spearman’s rank-order correlations
Spearman’s rank-order correlation is a specific type of correlation analysis, which assess the relationship between two variables with regard to its strength and direction.
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standardizing
Standardizing refers to a procedure of preparing the data for analysis, in which all data are transformed such that their mean across the participants lies at 0 and that their standard deviation is 1.
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sample size
The sample size refers to the number of people from whom data is collected in a study.
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R script
An R script is a document written in the programming language R which contains a number of commands that the computer should execute. For this study, all commands necessary to run the analyses reported here are compiled in such a script, which is available online, so that everyone who is interested in them can download the script and rerun all analyses on their own computer.
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R statistical programming language
R is a computer program that can produce statistical analyses. To run an analysis, scientists tell this program what they want to do in a specific programming language which the computer speaks.
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accumulated evidence
Accumulated evidence refers to the results of several studies taken together.
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tau-immunoreactive neurofibrillary tangles (NFTs)
NFTs occur when tau proteins are deformed, clump together, and abnormally accumulate. These accumulations are toxic to neurons If these tangles happen in neurons, they can be observed using a microscope.
NFTs are always associated with brain disease and are seen in CTE, Alzheimer's disease, and other neurological conditions. NFTs cause neurodegeneration, neuron death, cognitive issues, dementia, and are ultimately fatal.
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Neuropathological analysis of postmortem brains from military veterans with blast exposure and/or concussive injury revealed CTE-linked neuropathology
When they looked at the brains of people who suffered from TBI, the authors saw abnormalities ("neuropathologies") characteristic of CTE.
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second impact syndrome
If the brain does not have enough time to recover after TBI, it might respond to further TBI with sudden and often fatal swelling.
Second impact syndrom most commonly affects teenagers and young adults. It is very rare and will often result in death.
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amnesia
Partial or total memory loss or impairment
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phosphorylated tauopathy
Disorders caused by abnormal accumulation of phosphorylated tau protein in the brain.
If a protein is phosphorylated, it means that it has a phosphoryl group (PO<sub>3</sub><sup>-</sup>) attached to it.
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foliaceous
Foliaceous means "leafy." Foliaceous corals create thin layers of skeleton that somewhat resemble plant leaves.
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scienceintheclassroom.org scienceintheclassroom.org
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high-impact
The impact of a publication can be measured in several different ways. A common metric to assess the impact of a journal is the impact factor, a numerical indicator calculated based on the number of citations and published articles within a given year.
For this paper, the authors considered an article to be "high-impact" if it was within the top 1% most cited publications in its cohort.
For more information about assessing impact, see http://researchguides.uic.edu/if
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nonparametrically
Nonparametric statistical models are often used for data that are ranked.
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covariates
A covariate is a variable that is used in a regression analysis. It is a variable that might be responsible for the outcome of a study, or that might be interfering.
Here, all of the additional variables added in each model were covariates (writing ability, gender, ethnicity, etc.)
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principal investigator (PI)
A principal investigator is the holder of an independent grant administered by a university and the lead researcher for the grant project, usually in the sciences.
The phrase is also often used as a synonym for "head of the laboratory" or "research group leader."
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U.S. Patent and Trademark Office (USPTO)
The United States Patent and Trademark Office is an agency of the U.S. Department of Commerce which stores, classifies, and disseminates information on patents and gives grant patents for the protection of inventions and to register trademarks.
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PubMed
PubMed is a database of medical and biological publications, created by the National Center for Biotechnology Information. It is the free version of the database MEDLINE.
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research project (R01)
The Research Project (R01) grant is a type of grant awarded by the National Institutes of Health that provides support for health-related research and development.
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- Jun 2017
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social physicality.
A physical interaction with social meaning.
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Threshold amplitudes
The lowest level stimulation current that causes USVs.
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22-kHz alarm calls
A rat vocalization in response to fear or the presence of a threat.
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dopaminergic mechanisms
Dopamine is a neurotransmitter that is involved in reward and reinforcement pathways in the brain.
Dopaminergic mechanisms use dopamine to promote repetition of and re-exposure to these positive things
Read more in Science News for Students: https://www.sciencenewsforstudents.org/article/explainer-what-dopamine
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50-kHz
kHz is an abbreviation for kilohertz, which measures frequency in cycles per second. In this context it is measuring the frequency of a sound wave.
Humans can typically detect sound waves with frequencies up to 20 kHz, but that range declines with age.
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coactivation
Activation by multiple stimuli.
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confounding
An outside factor that can also impact the dependent variable.
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tactile neural representation
Neural representation indicates the region of the brain that is activated in response to some stimulus.
Tactile neural representation refers to the region (the somatosensory cortex) that is activated in response to some sort of touch.
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somatosensory afferents
Afferents are the neurons that send signals inward, back to the central nervous system and the brain.
Somatosensory afferents are the neurons that send signals to the brain in response to touch.
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conspecifics
Animals of the same species.
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dedicated peripheral mechanisms of tickle
Sensory neurons that specifically detect tickling.
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serial sectioning
Successive microscopic images of a tissue.
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amniotes
The group of animals that lay fertilized eggs on land or retain the fertilized egg in the mother. They include reptiles, birds, and mammals.
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canonical
The usual or natural state.
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parasagittal
An imaginary plane that divides a body into left and right halves.
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Hematoxylin and eosin (H&E)
A widely used stain in histology which dyes nuclei blue and plasma pink.
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- May 2017
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z, F, t, and χ2
z, F, t and X2 test statistics are parameters that are calculated from a sample and compared with what is expected given the null hypothesis (that there is no effect in reality). They allow inferences on whether the data can be used to reject the null hypothesis and assume an effect is present.
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Cohen’s d.
Cohen's d is a measure for the size of an effect, used to report the standardized difference between two means. It is used to judge if an effect is small (d>0.20), medium (d>0.50) or large (d>0.80).
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t test for dependent samples
The t-test for dependent samples is a statistical procedure that is used on paired data to compare the means of two groups.
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central tendency
The central tendency of a distribution is captured by its central, or typical values. Central tendency is usually assessed with means, medians ("middle" value in the data) and modes (most frequent value in the data).
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Fisher’s method
Fisher's method is a statistical procedure for conducting meta analyses, in which the results of all included studies are combined. The procedure examines the p-values of the individual studies, and allows inferences on whether the null hypothesis (that there are no effects) holds.
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two-tailed
A two-tailed test looks for a hypothesized relationship in two directions, not just one. For example, if we compare the means of two groups, the null hypothesis would be that the means are not different from each other.
The alternative hypothesis for a two-tailed test would be that the means are different, regardless if the one is bigger or smaller than the other.
For a one-tailed test, one would formulate a more specific alternative hypothesis, for instance that the mean of the first group is bigger than the mean of the second group.
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meta-analyses
Meta-analyses integrate the results of multiple studies to draw overall conclusions on the evidence.
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covaries
Covariation indicates how two variables change together, and is the basis needed to calculate a correlation.
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P value
A p-value is a statistical threshold for determining if a result is extreme enough to be considered compelling evidence, because it is unlikely that this result would show in the data if the effect did not exist in reality.
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functional magnetic resonance imaging
Functional magnetic resonance imaging is a procedure that detects the activity of areas in the brain by measuring blood flow.
It can be used to see what parts of the brain are involved in different processes.
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eye tracking machines
Eye tracking machines are devices that can record eye-movements and make it possible to show what information people look at without asking them explicitly.
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autism
Autism is a mental condition that makes it difficult to communicate and form relationships with others. People with autism can also have difficulty using language or thinking about abstract concepts.
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macaques
Macaques are a type of monkeys.
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F test
An F-test is a statistical procedure that assesses if the variance of two distributions are significantly different from each other.
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t test
A t-test is a statistical procedure that assesses if the means of two distributions are significantly different from each other.
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citation impact
Citation impact is determined by how frequently a paper is cited and built upon by subsequent literature.
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tractable
Easy to deal with.
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a priori
A priori means something was deduced or determined from theoretical considerations, before collecting data.
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cognitive psychology
Cognitive psychology is a subdiscipline of psychology that studies mental processes like perception, problem solving, attention or memory.
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social psychology
Social psychology is a subdiscipline of psychology that studies how people interact with their social environment, and how their thoughts and behaviors are affected by others.
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selection biases
Selection bias here refers to systematic error in the way studies are included or excluded in the sample of studies which would be replicated. An unbiased selection would be truly random, such that the sample of studies used for replication would be representative of the population of studies available.
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transparency
Transparency here means that the process in which a specific result was achieved is made as accessible for other researchers as possible, by explaining publicly, and in detail, everything that was done in a study to arrive at a specific result..
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false negative
A false negative is a result that erroneously indicates no effect exists: although the data do not suggest that an effect exists, in reality, this effect does exist.
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false positive
A false positive is a result that erroneously indicates an effect exists: although the data suggests an effect exists, in reality, the effect does not exist.
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moderate
In statistics, moderation refers to the dependence of the relationship between two variables on a third variable.
For example, the positive relationship between socioeconomic status and health (the higher one's status, the better one's health) could be moderated by one's sense of control: people in low income groups with high sense of control might show health levels comparable with people from high-income groups, whereas people in low income groups with low sense of control have worse health (Lachman & Weaver, 1998).
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bias
Bias refers to a systematic error or a process that interferes with accurate results.
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confidence interval
A confidence interval is the range of values in which the true value of the variable of interest would fall, if the experiment were to be repeated again and again. In the case of the 95% confidence interval, the true value would fall in this range in 95% of all cases. Confidence intervals are often referred to with the abbreviation "CI".
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effects
An effect is an observed phenomenon, where differences in one circumstance lead to observable differences in an outcome.
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recruiting
Recruitment refers to the successful addition of new individuals to a population.
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succession
Ecological succession is the predictable change in a community over time, usually referring to changes after a disturbance or initial colonization of a habitat.
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polychaetes
Polychaetes are a diverse group of worms. Polychaetes are commonly found at the bottom of the ocean and are an important part of marine food webs.
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bottom topography
The shape and features of the bottom of the ocean.
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Demersal plankton
The demersal zone is the layer of water nearest to the bottom of the ocean. Plankton are tiny microscopic organisms that live in the water column.
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schooling
Swimming together in a group. Schooling behavior provides benefits to individual fish, such as safety in numbers.
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Motile organisms
Motile organisms are organisms that can move around, such as shrimp or fish. Sessile organisms, like corals, do not move for the majority of their lives.
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encrusting
Encrusting animals form a thin layer (i.e. a "crust") over another hard surface.
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patchy
Uneven, with some spots being affected more than others.
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substratum
The substratum is the underlying layer of rock or sediment. This refers to the surface that the corals attach to.
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breaker zone
As ocean waves move towards shallower waters, they eventually become unstable and break. A breaker zone is a region where waves begin breaking.
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taxonomic
Taxonomy is the science of describing, identifying and classifying species. Taxonomic differences, in this context, are differences in the species present.
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cortical layering
Development of the layers of the brain.
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caspase 3/7
Caspases are endoproteases (a type of enzyme that breaks down proteins) that play a critical role in both inflammation and cell death.
The presence of caspase 3 and 7 can be used as a sign that cells are preparing to die.
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pyknotic
A nucleus whose chromatin has condensed in preparation for apoptosis (programmed cell death)
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Apoptotic nuclei
A nucleus that has started to prepare for programmed cell death (apoptosis).
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glial
Cells located in the central nervous system which protect and support neurons in their function.
Glial cells differ from neurons since they do not participate in electrical signaling.
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ultrastructural
Smaller than what can be seen with a light microscope
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in vitro
In a controlled experimental environment.
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Student’s t test
A statistical test that is used to determine if two sets of data are significantly different from each other.
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MOI
The "multiplicity of infection," which is the average number of virus particles that infect a cell.
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neural stem cells
Undifferentiated cells in the nervous system that have the potential to develop into any type of cell.
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induced pluripotent stem (iPS)
These are differentiated cells which have been reprogrammed into pluripotent ones. This means that they have the ability to develop into any type of cell.
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amniotic fluid
The liquid that surrounds the fetus for its protection, keeping a constant temperature and environment.
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placenta
An organ that develops only during pregnancy to provide oxygen and nutrients needed for the growth of the baby.
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flavivirus
A type of viruses usually spread through mosquito and tick bites. They include West Nile and dengue virus.
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Syphilis
Syphilis is a sexually transmitted infection caused by a bacteria known as Treponema pallidum.
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Herpes virus
Herpes virus infections take place around mouth, lips, genitals, or rectum.
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Cytomegalovirus
CMV infections spread through contact with body fluids, and often occur in those with weak immune systems.
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Rubella
Rubella is an RNA virus that is normally spread through the air by coughing or breathing.
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Toxoplasmosis
A disease caused by a parasite called Toxoplasma gondiiand.
It is usually transmitted by eating uncooked food that contains cysts or by exposure to infected cat feces.
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external insults
Brain injuries.
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etiology
The cause of a disease or disorder.
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heterogeneous
Diverse.
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abrogates
Prevents.
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electron microscopy
A technique that uses a beam of electrons as a light source and has a magnification of up to 1,000,000x (a light microscope's magnification power is 1,500x).
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immunocytochemistry
A microscopy technique for seeing cellular components by targeting them in tissue samples.
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organoids
An organ bud (miniature organ) that is anatomically similar to the organ it models. Organoids are used to study organ development and function.
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neurospheres
A three-dimensional culture system made up of free-floating clusters of neural stem cells. They are used to study neural precursor cells in vitro.
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microcephaly
An abnormally small head due to failure of the brain to grow sufficiently. It is associated with mental disability.
The growth of the brain can be impaired by many genetic and environmental factors, including infections by viruses and genetic syndromes.
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Zika virus (ZIKV)
A RNA virus transmitted by mosquitos and sexual interaction with a carrier.
It was first isolated from the Zika Forest of Uganda in 1947. It was previously only known to occur in a narrow range in Africa and Asia. However, in 2015 there was a Zika outbreak in Brazil.
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Matthew effect
The Matthew Effect can be summarized as, "the rich get richer and the poor get poorer." It describes the idea that benefits are distributed unevenly, and that those who already have benefits will continue to accumulate them while those without will not have the chance.
In scientific publication, the Matthew Effect refers to the phenomenon where researchers who are established publish more often simply because they are established (and regardless of the quality of their work).
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regression
Regression is a measure of the relation between the mean value of one variable and corresponding values of other variables. There are different types of regression, all of which are used to identify trends in data.
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Poisson regressions
A Poisson regression is a form of regression analysis where we have a random variable, which is equal to the number of events over a period of time if these events are independent and occur at a constant speed.
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institutional affiliation
An applicant's institutional affiliation is the organization that has agreed to be the legal recipient of the grant. This organization can be a nonprofit, a university, or an employer.
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standard deviation (SD)
Standard deviation is a statistical measure that is used to describe how much variation there is in a data set. A high standard deviation means that the data is very spread out.
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value-added
Value-added is the amount by which the value of the product is increased. Here, it means by how much peer review increases new insights about the quality of grant applications.
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U.S. National Institutes of Health
A grant is a money given to enterprises, organizations, and individuals for research, development, and education. Grants do not have to be returned, but most granting organizations require a report about the progress of the outcome.
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peer-review
Peer-review is the review process for scientific articles, research, or ideas by scientific experts in the same field.
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- Apr 2017
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forme fruste
An atypical or less severe form of a disease.
Here, the authors use the term to mean that although their mouse model replicates most of the major signs of CTE, it is limited in not developing the mature NFTs seen in human cases.
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contemporaneous
Occurred at the same time.
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escape latencies
The length of time it takes to escape the maze.
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Barnes maze
A tool used to study spatial learning and memory. The fact that blast-exposed mice took longer to escape and had poorer memories of the maze suggests a cognitive deficit due to blast exposure.
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candidate mechanisms
Although we understand a lot about the hippocampus and its function, there is still a lot of active research into the exact way that learning and memory work. Because of this, the word "candidate" is used to qualify this statement.
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long-term potentiation
Long-term potentiation (LTP) is a measure of synaptic plasticity, or the ability of synapses to adapt and change. LTP is important to learning and memory. If it is impaired, it can cause cognitive deficits, specifically in processes important to memory.
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axonal conduction
The movement of electrophysiological signals along the axon. Slowed (or prolonged) conduction is a sign of a defect in the relaying of signals between different parts of the brain.
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bilaterally
On both sides of the brain.
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inclusion bodies
Clumps of stable molecules found in the nuclei and cytoplasm of cells. They are usually a sign of viral infection and are the site of viral multiplication, but they can also indicate neurological disease.
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dystrophic myelinated nerve fibers
Some axons are surrounded by a layer of myelin, a fatty, white substance that helps regulate signal transmission.
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stratum radiatum
A region of the hippocampus.
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paucity
Scarcity.
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stratum pyramidale
A region of the hippocampus.
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pathology
Abnormalities.
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Ultrastructural
Refers to a scale that is beyond detection by light microscopy, requiring a magnification that can only be achieved by electron microscope.
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Purkinje cells
Cells that help regulate nerve impulses.
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dystrophic axons
Axons that are wasting away.
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pyknotic
Neurons whose nuclear chromatin has condensed and gathered within the nucleus. This is a step that cells undergo during apoptosis or necrosis, two methods of cell death. Pyknotic neurons are either dead or dying.
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chromatolytic
Dead or dying neurons. These neurons have suffered a breakdown of Nissl bodies, large granular bodies that are the site of protein synthesis.
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brain parenchyma
"Parenchyma" refers to the bulk component of a tissue. The brain parenchyma includes the dense network of brain cells and their processes, but does not include membranes, vascular elements, etc.
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dynamic pressure
Dynamic pressure is more complex than static pressure. It includes not only the pressure that results from particles in natural, random motion, but collisions of particles that result from movement in the flow direction.
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static (incident) pressure profile
Like all moving fluids, blast shockwaves have two different pressure measures: static and dynamic. Static pressure is the pressure exerted on one particle of the fluid when it is at rest. Dynamic pressure incorporates the movement of the fluid (or gas), and is a measure of the kinetic energy of the fluid.
Static pressure can be measured with a "side-on" sensor.
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murine
Mouse.
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U-fibers
A type of fiber that connects different gyri (ridges) in the brain.
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multifocal axonopathy
Damage to axons in multiple locations.
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astrocytosis
An increase in the number of astrocytes that is due to damage to the nervous system and a sign of neurodegenerative disease.
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cardiac arrhythmia
An irregular heartbeat (too fast, too slow, or the wrong rhythm).
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OxyContin
An opioid pain medication with a high risk of addiction. If too high of a dose is taken, it can be fatal.
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exacerbation
Worsening.
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psychomotor speed
Reduced reaction time in movements related to mental processes.
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posttraumatic stress disorder (PTSD)
A disorder that develops in some people who have a terrifying or dangerous experience. There are many symptoms, but the major signs are increased anxiety, flashbacks, nightmares, and uncontrollable thoughts about the event.
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analgesics
Pain relievers.
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aspiration pneumonia
An infection that occurs after inhaling food, liquid, or vomit into the lungs.
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microglia
Microglia are immune cells in the brain that are related to the cells in our peripheral immune system. Cells from our peripheral immune system cannot enter the brain, so the brain has to develop its own innate immune system. Microglia are a key component of this.
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perivascular foci
Spaces around blood vessels.
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glial tangles
Similar to NFTs but in glial cells instead of neurons. These tangles are also associated with abnormal tau protein accumulation and, when they are observed in the brain, are an indicator of disease.
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intracerebral hemorrhage
Bleeding in the brain.
An intracerebral hemorrhage can disrupt blood flow and deprive the brain of oxygen, put pressure on brain tissue around the hemorrhage, and introduce toxins into the brain.
Intracerebral hemorrhage can be fatal.
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basilar aneurysm
Weakness in the walls of the basilar artery at the base of the brain, resulting in ballooning. Rupture of this blood vessel can cause sudden onset of neurological symptoms and is often lethal.
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normal controls of comparable ages without a history of blast exposure
A control is a group or individual that is used as a standard of comparison in experiments.
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clinicopathological correlation
The relationship between the sequence of events that led up to the death of the patient or subject and the findings from an autopsy.
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oscillation
Back and forth movement.
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hemorrhage
Occurs when blood vessels are punctured and blood begins to flow out of them.
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neuropsychiatric spectrum disorder
A group of psychiatric disorders with underlying neurological causes.
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the mechanisms of injury
How exposure to blasts injures the brain.
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www.scienceintheclassroom.org www.scienceintheclassroom.org
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urban design
Urban design is the process of organizing cities (including buildings, roads, and green spaces) that relies on principles from many disciplines in architecture, engineering, and planning.
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catalyst
A person serves as a catalyst if she or he inspires or stimulates an activity or event.
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take-make-waste model
Western-industrial countries tend to extract resources from the earth (e.g., mine for minerals and ore), then make products for people to purchase (e.g., cellphones), and when people are done using the product, they throw it away.
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sustainable living
Lifestyles that can be maintained indefinitely, without adversely impacting others (human and nonhuman), including future generations.
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status inequalities
Certain people, races, and social classes are valued more in some societies.
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cultural worldviews
Everyone develops a worldview. Worldviews are implicit (i.e. unquestioned or undoubted) sets of assumptions and beliefs. We experience worldviews as just the way things are.
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social modeling
Setting an example for others through one's own actions.
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denial
Claiming that anxiety-producing information is false. For instance, "climate change deniers."
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salience
Noticeable; attention-grabbing.
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anthropocentric
Human-focused (as opposed to considering the entire ecosystem).
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trajectory
Path, course, route.
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informal
Informal social collectives are groups of people that form because of shared interests, preferences, or physical proximity. For instance, people in a neighborhood don't necessarily know anyone when they move in and they are not obligated to interact. Yet, they may join together with other neighbors to solve a neighborhood-level problem or to socialize.
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Urbanization
The increasing trend toward city-living, as compared to living in smaller communities or having a rural lifestyle.
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perpetuating or redirecting situational forces
Each of us can choose to either support (perpetuate) or change (redirect) unsustainable social contexts (situational forces).
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situational drivers
Cues about how to behave. Cues can be provided by the way buildings are designed, sets of rules, and social feedback. People pay attention to cues about how they should behave in order to avoid negative consequences such as making mistakes and being laughed at.
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“choice architecture”
The way that different options are presented to someone making a choice.
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formal social collectives
Formal social collectives are groups of people who have an official purpose. Businesses, religious groups (e.g, parishes, synagogues, mosques, sangas, etc.), governmental bodies, and schools are examples of formal social collectives. This can be used interchangeably with "formal organizations."
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Formal organizations
Formal organizations are groups of people who have an official purpose. Businesses, religious groups (e.g, parishes, synagogues, mosques, sangas, etc.), governmental bodies, and schools are examples of formal organizations.
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Place-based collectives
Groups of people who share a physical space, such as a neighborhood.
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industrial infrastructure
The large physical systems that communities develop to manage shared resources such as energy creation and delivery, water purification and delivery, communication (e.g., fiberoptics), sewage and waste collection, and transportation (e.g., roads, bridges, subways, trains).
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motivated cognition
Human thinking is not neutral and unbiased; instead, the brain looks for information and makes judgements consistent with already-existing beliefs.
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