70 research outputs found
A Program for At-Risk High School Students Informed by Evolutionary Science
Improving the academic performance of at-risk high school students has proven difficult, often calling for an extended day, extended school year, and other expensive measures. Here we report the results of a program for at-risk 9th and 10th graders in Binghamton, New York, called the Regents Academy that takes place during the normal school day and year. The design of the program is informed by the evolutionary dynamics of cooperation and learning, in general and for our species as a unique product of biocultural evolution. Not only did the Regents Academy students outperform their comparison group in a randomized control design, but they performed on a par with the average high school student in Binghamton on state-mandated exams. All students can benefit from the social environment provided for at-risk students at the Regents Academy, which is within the reach of most public school districts
Evidence-based Kernels: Fundamental Units of Behavioral Influence
This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior
Squatting test: a dynamic postural manoeuvre to study baroreflex sensitivity.
INTRODUCTION: Squatting is an active posture test that can be used to assess baroreflex sensitivity. Indeed, the shift from squatting to standing imposes a major orthostatic stress leading to rapid and large changes in arterial blood pressure (BP) and heart rate (HR) allowing precise baroreflex assessment. MATERIAL AND METHODS: BP and HR can be continuously and non-invasively monitored with a Finapres device. RESULTS: The standing to squatting transition is accompanied by rises in BP, pulse pressure and cardiac output, mainly due to increased venous return, and by a secondary reduction in HR. Conversely, the squatting to standing transition is associated with an immediate drop in BP and both reflex tachycardia and vasoconstriction. This mirror changes in BP and HR, mimicking those observed with the classical pharmacological approach using vasopressor/vasodilating agents, allows the calculation of the so-called baroreflex gain. DISCUSSION: The present review describes the haemodynamic changes occurring in normal subjects during the shifts from standing to squatting and from squatting to standing and discusses the underlying cardiovascular and autonomic mechanisms. CONCLUSION: This careful analysis in healthy individuals should help in the understanding of disturbances that may be observed in patients with autonomic dysfunction, such as in diabetic patients with cardiovascular autonomic neuropathy
Patterns of genetic diversity of the Hawaiin spinner dolphin (Stenella longirostris)
We used population genetic analyses to investigate the genetic structure of the Hawaiian spinner dolphin (Stenella longirostris). Genetic samples were collected from spinner dolphins at locations across the Hawaiian Archipelago: Kure Atoll (n=34), Midway Atoll (n=57), Pearl & Hermes Reef (n=21), French Frigate Shoals (n=15), Ni'ihau (n=39), O'ahu (n=47), Maui/Lana'i (n=60), and the Big Island of Hawai'i (n=77). A 429-base-pair region of the mitochondrial DNA control region was used to evaluate genetic diversity and population structure. Peaks in genetic diversity were found at the Big Island of Hawai'i (π=0.0082) and French Frigate Shoals (π=0.0072), and genetic diversity was reduced at the three most northwestern Hawaiian atolls (Kure Atoll π=0.0025, Midway Atoll π=0.0019, and Pearl & Hermes Reef π=0.0017). Analysis of Molecular Variance (AMOVA) and exact tests of population subdivision indicated significant genetic structure for the spinner dolphin within Hawai'i. With few exceptions, dolphins at every island were found to be significantly genetically differentiated from dolphins at every other island for one or more tests of population subdivision (FST or ΦST ≥ 0.02, p < 0.05). Exceptions included dolphins at Kure Atoll, Midway Atoll, and Pearl & Hermes Reef, which together seemed to form one interbreeding group, distinct from the rest of the Archipelago. Dolphins at O'ahu were also an exception in that they were not differentiated significantly from dolphins at Kure Atoll, Midway Atoll, or Pearl & Hermes Reef.link_to_subscribed_fulltex
A systematic review of the relationship between blood loss and clinical signs.
INTRODUCTION: This systematic review examines the relationship between blood loss and clinical signs and explores its use to trigger clinical interventions in the management of obstetric haemorrhage. METHODS: A systematic review of the literature was carried out using a comprehensive search strategy to identify studies presenting data on the relationship of clinical signs & symptoms and blood loss. Methodological quality was assessed using the STROBE checklist and the general guidelines of MOOSE. RESULTS: 30 studies were included and five were performed in women with pregnancy-related haemorrhage (other studies were carried in non-obstetric populations). Heart rate (HR), systolic blood pressure (SBP) and shock index were the parameters most frequently studied. An association between blood loss and HR changes was observed in 22 out of 24 studies, and between blood loss and SBP was observed in 17 out of 23 studies. An association was found in all papers reporting on the relationship of shock index and blood loss. Seven studies have used Receiver Operating Characteristic Curves to determine the accuracy of clinical signs in predicting blood loss. In those studies the AUC ranged from 0.56 to 0.74 for HR, from 0.56 to 0.79 for SBP and from 0.77 to 0.84 for shock index. In some studies, HR, SBP and shock index were associated with increased mortality. CONCLUSION: We found a substantial variability in the relationship between blood loss and clinical signs, making it difficult to establish specific cut-off points for clinical signs that could be used as triggers for clinical interventions. However, the shock index can be an accurate indicator of compensatory changes in the cardiovascular system due to blood loss. Considering that most of the evidence included in this systematic review is derived from studies in non-obstetric populations, further research on the use of the shock index in obstetric populations is needed
Effects of dehydration on cerebrovascular control during standing after heavy resistance exercise
Rolling stones and stable homes: Social structure, habitat diversity and population genetics of the Hawaiian spinner dolphin (Stenella longirostris)
Spinner dolphins (Stenella longirostris) exhibit different social behaviours at two regions in the Hawaiian Archipelago: off the high volcanic islands in the SE archipelago they form dynamic groups with ever-changing membership, but in the low carbonate atolls in the NW archipelago they form long-term stable groups. To determine whether these environmental and social differences influence population genetic structure, we surveyed spinner dolphins throughout the Hawaiian Archipelago with mtDNA control region sequences and 10 microsatellite loci (n = 505). F-statistics, Bayesian cluster analyses, and assignment tests revealed population genetic separations between most islands, with less genetic structuring among the NW atolls than among the SE high islands. The populations with the most stable social structure (Midway and Kure Atolls) have the highest gene flow between populations (mtDNA ST < 0.001, P = 0.357; microsatellite F ST = -0.001; P = 0.597), and a population with dynamic groups and fluid social structure (the Kona Coast of the island of Hawai'i) has the lowest gene flow (mtDNA 0.042 < ST < 0.236, P < 0.05; microsatellite 0.016 < F ST < 0.040, P < 0.001). We suggest that gene flow, dispersal, and social structure are influenced by the availability of habitat and resources at each island. Genetic comparisons to a South Pacific location (n = 16) indicate that Hawaiian populations are genetically depauperate and isolated from other Pacific locations (mtDNA 0.216 < F ST < 0.643, P < 0.001; microsatellite 0.058 < F ST < 0.090, P < 0.001); this isolation may also influence social and genetic structure within Hawai'i. Our results illustrate that genetic and social structure are flexible traits that can vary between even closely-related populations. © 2010 Blackwell Publishing Ltd.link_to_subscribed_fulltex
Population genetic analyses aid in the designation of spinner dolphin management units in the Hawaiian Archipelago
Workshop on Science and Conservation of Hawaiian Odontocetes, Tampa, FL., 26 November 2011
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