314 research outputs found

    EFFECTS OF COVER BOARD AGE, SEASON, AND HABITAT ON THE OBSERVED ABUNDANCE OF EASTERN RED-BACKED SALAMANDERS (PLETHODON CINEREUS)

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    Plethodontid salamanders are potentially good ecological indicator species in woodland habitats due to their abundance and sensitivity to changes in the environment. The use of terrestrial salamanders as ecological indicators depends on effective means of surveying their abundance and distribution. Our study examined the use of old and new artificial cover boards by Eastern Red-backed Salamanders (Plethodon cinereus). We also considered the effects of season (spring vs. fall) and habitat type (deciduous vs. coniferous vs. mixed) on cover board use by P. cinereus. Our results indicated that P. cinereus abundance was greater under old cover boards compared to new cover boards. However, the difference between the use of old and new cover boards was greater during the spring than the fall, suggesting that the effect of cover board age became weaker over time. Plethodon cinereus showed strong seasonal variation in observed abundance, with peaks during the spring and fall seasons and very low surface activity during the summer. Plethodon cinereus had higher observed abundance in deciduous habitats than in coniferous and mixed habitats. Our results suggested that care should be taken to account for cover board age in long-term monitoring programs, especially if cover boards are replaced during a study

    Water ingestion decreases cardiac workload time-dependent in healthy adults with no effect of gender

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    Ingestion of water entails a variety of cardiovascular responses. However, the precise effect remains elusive. We aimed to determine in healthy adults the effect of water on cardiac workload and to investigate potential gender differences. We pooled data from two controlled studies where blood pressure (BP) and heart rate (HR) were continuously recorded before and after the ingestion of 355 mL of tap water. Additionally, we calculated double product by multiplying systolic BP with HR and evaluated spectral parameters referring to vagal tone. All parameters were investigated for potential differences based on gender. In response to water, HR, systolic BP, and double product decreased significantly during the first 30 min. However, these effects were attenuated for HR and double product and even abolished for systolic BP over the subsequent 30 min. Over the entire post-drink period (60 min), decreases in HR and double product (all P < 0.05) were observed. Spectral markers for vagal tone increased with the on-set of the water drink and remained elevated until the end (P < 0.005). No significant gender difference in cardiac workload parameters was observed. We provide evidence that drinking water decreases, in a time-dependent fashion, cardiac workload and that these responses appear not to be influenced by gender

    Perspective: cardiovascular responses to sugar-sweetened beverages in humans: a narrative review with potential hemodynamic mechanisms

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    Cardiovascular diseases are still the primary cause of mortality worldwide, with high blood pressure and type 2 diabetes as major promoters. Over the past 3 decades, almost in parallel with the rise in cardiovascular disease incidence, the consumption of sugar-sweetened beverages (SSBs) has increased. In this context, SSBs are potential contributors to weight gain and increase the risk for elevations in blood pressure, type 2 diabetes, coronary heart disease, and stroke. Nevertheless, the mechanisms underlying the cardiovascular and metabolic responses to SSBs, in particular on blood pressure, are poorly understood. We discuss and propose potential mechanisms underlying differential effects of sugars on postprandial blood pressure regulation; provide evidence for additional molecular contributors, i.e., fibroblast growth factor 21, towards sugar-induced cardiovascular responses; and discuss potential cardiovascular neutral sugars. Furthermore, we explore whether pre-existing glucose intolerance in humans exacerbates the cardiovascular responses to SSBs, thus potentially aggravating the cardiovascular risk in already-susceptible individuals

    Perspective: cardiovascular responses to sugar-sweetened beverages in humans: a narrative review with potential hemodynamic mechanisms

    Get PDF
    Cardiovascular diseases are still the primary cause of mortality worldwide, with high blood pressure and type 2 diabetes as major promoters. Over the past 3 decades, almost in parallel with the rise in cardiovascular disease incidence, the consumption of sugar-sweetened beverages (SSBs) has increased. In this context, SSBs are potential contributors to weight gain and increase the risk for elevations in blood pressure, type 2 diabetes, coronary heart disease, and stroke. Nevertheless, the mechanisms underlying the cardiovascular and metabolic responses to SSBs, in particular on blood pressure, are poorly understood. We discuss and propose potential mechanisms underlying differential effects of sugars on postprandial blood pressure regulation; provide evidence for additional molecular contributors, i.e., fibroblast growth factor 21, towards sugar-induced cardiovascular responses; and discuss potential cardiovascular neutral sugars. Furthermore, we explore whether pre-existing glucose intolerance in humans exacerbates the cardiovascular responses to SSBs, thus potentially aggravating the cardiovascular risk in already-susceptible individuals

    Explaining the resurgent popularity of the wild: motivations for wild plant gathering in the Biosphere Reserve Grosses Walsertal, Austria

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    Background: Wild plant gathering becomes again a popular and fashionable activity in Europe after gathering practices have been increasingly abandoned over the last decades. Recent ethnobotanical research documented a diversity of gathering practices from people of diverse socio-economic and cultural backgrounds who gather in urban and rural areas. Few efforts were though made to study the motivations for gathering wild plants and to understand the resurgent popularity of wild plant gathering. This paper addresses the following research questions: (1) which motivations activate wild plant gatherers? (2) which motivation-types of gatherers exist in the Grosses Walsertal? (3) how do the motivations for gathering relate to the socio-demographic background of gatherers? Methods: Field research was conducted in the Grosses Walsertal, Austria in the years 2008 and 2009 in two field research periods. Thirty-six local farmers were first interviewed with semi-structured interviews. The motivations identified in these interviews were then included in a structured questionnaire, which was used to interview 353 residents of the valley. Pupils of local schools participated in the data collection as interviewers. Principal Component Analysis was used to categorize the motivations and to identify motivation-types of wild plant gatherers. Generalized Linear Models were calculated to identify relations between motivations and the socio-demographic background of gatherers. Results: The respondents listed 13 different motivations for gathering wild plants and four motivations for not gathering. These 17 motivations were grouped in five motivation-types of wild plant gatherers, which are in decreasing importance: product quality, fun, tradition, not-gathering, income. Women, older respondents and homegardeners gather wild plants more often for fun; older respondents gather more often for maintaining traditions; non-homegardeners more frequently mention motivations for not gathering. Conclusions: The resurgent popularity of wild plant gathering comes along with an internalization of motivations: the main motivations for wild plant gathering changed from the external extrinsic motivation of gathering because of necessity towards the internalized extrinsic motivation of gathering for the highly esteemed product quality and the intrinsic motivation of gathering for the pleasure of the activity itself. This internalization of motivations supports the persistence of wild plant gathering, a positive self-perception of gatherers and good quality of engagement with wild plant gathering.(VLID)90709

    Cerebro- and cardio-vascular responses to energy drink in young adults: Is there a gender effect?

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    Background and Purpose: Energy drinks (EDs) are suspected to induce potential adverse cardiovascular effects and have recently been shown to reduce cerebral blood flow velocity (CBFV) in young, healthy subjects. Gender differences in CBFV in response to EDs have not previously been investigated, despite the fact that women are more prone to cardiovascular disturbances such as neurocardiogenic syncope than men. Therefore, the aim of this study was to explore gender differences in cerebrovascular and cardiovascular responses to EDs. Methods: We included 45 subjects in a retrospective analysis of pooled data from two previous randomized trials carried out in our laboratory with similar protocols. Beat-to-beat blood pressure, impedance cardiography, transcranial Doppler, and end-tidal carbon dioxide (etCO₂) measurements were made for at least 20 min baseline and for 80 min following the ingestion of 355 mL of a sugar-sweetened ED. Gender and time differences in cerebrovascular and cardiovascular parameters were investigated.Results: CBFV was significantly reduced in response to ED, with the greatest reduction observed in women compared with men (−12.3 ± 0.8 vs. −9.7 ± 0.8%, P P P Conclusions: ED ingestion reduced CBFV over time, with a greater reduction observed in women compared with men. Our results have potential implications for women ED consumers, as well as high-risk individuals

    Substantial inter-subject variability in blood pressure responses to glucose in a healthy, non-obese population

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    Aim: A large inter-subject variability in the blood pressure (BP) response to glucose drinks has been reported. However, the underlying factors remain elusive and we hypothesized that accompanying changes in glucose metabolism affect these BP responses.Methods: Cardiovascular and glycemic changes in response to a standard 75 g oral-glucose-tolerance-test were investigated in 30 healthy, non-obese males. Continuous cardiovascular monitoring, including beat-to-beat BP, electrocardiographically deduced heart rate and impedance cardiography, was performed during a 30 min baseline and continued up to 120 min after glucose ingestion. Blood samples were taken at baseline, 30, 60, 90, and 120 min for the assessment of glucose, insulin and c-peptide. Additionally, we evaluated body composition by using validated bioelectrical impedance techniques.Results: Individual overall changes (i.e., averages over 120 min) for systolic BP ranged from −4.9 to +4.7 mmHg, where increases and decreases were equally distributed (50%). Peak changes (i.e., peak averages over 10 min intervals) for systolic BP ranged from −1.3 to +9.5 mmHg, where 93% of subjects increased systolic BP above baseline values (similar for diastolic BP) whilst 63% of subjects increased peak systolic BP by more than 4 mmHg. Changes in peak systolic BP were negatively associated with the calculated Matsuda-index of insulin sensitivity (r = −0.39, p = 0.04) but with no other evaluated parameter including body composition. Moreover, besides a trend toward an association between overall changes in systolic BP and total fat mass percentage (r = +0.32, p = 0.09), no association was found between other body composition parameters and overall BP changes.Conclusion: Substantial inter-subject variability in BP changes was observed in a healthy, non-obese subpopulation in response to an oral glucose load. In 63% of subjects, peak systolic BP increased by more than a clinically relevant 4 mmHg. Peak systolic BP changes, but not overall BP changes, correlated with insulin sensitivity, with little influence of body composition

    Logarithmic behavior of degradation dynamics in metal--oxide semiconductor devices

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    In this paper the authors describe a theoretical simple statistical modelling of relaxation process in metal-oxide semiconductor devices that governs its degradation. Basically, starting from an initial state where a given number of traps are occupied, the dynamics of the relaxation process is measured calculating the density of occupied traps and its fluctuations (second moment) as function of time. Our theoretical results show a universal logarithmic law for the density of occupied traps ˉϕ(T,EF)(A+Blnt)\bar{} \sim \phi (T,E_{F}) (A+B \ln t), i.e., the degradation is logarithmic and its amplitude depends on the temperature and Fermi Level of device. Our approach reduces the work to the averages determined by simple binomial sums that are corroborated by our Monte Carlo simulations and by experimental results from literature, which bear in mind enlightening elucidations about the physics of degradation of semiconductor devices of our modern life

    Cardiovascular responses to a glucose drink in young male individuals with overweight/obesity and mild alterations in glucose metabolism, but without impaired glucose tolerance

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    Little is known about whether mild aberrations in glucose metabolism, which are seen in overweight/obese subjects (OW/OB) without impaired glucose tolerance, affect regulator control elements for blood pressure homeostasis. Methods Hence, we measured in age-matched male subjects with normal weight (n = 16; BMI = 22.4 kg m−2) and OW/OB (n = 11; BMI = 28.6 kg m−2) continuous beat-to-beat blood pressure, heart rate, stroke volume, myocardial contractility and baroreflex sensitivity during a 30 min baseline and for 120 min after the ingestion of 75 g glucose dissolved in 300 mL tap water (OGTT). Blood samples for the assessment of plasma glucose and insulin were collected at baseline and every 30 min after the drink and homeostatic model assessment of insulin resistance (HOMA-IR) was calculated. Results At baseline, glucose (5.3 ± 0.4 SD vs 5.0 ± 0.4 mmol L−1; p = 0.01), insulin (7.4 ± 0.4 vs 3.7 ± 2.7 mU L−1; p = 0.02) and HOMA-IR (1.8 ± 1.3 vs 0.8 ± 0.6; p = 0.01) were significantly higher in subjects with OW/OB, but none classified as having impaired glucose tolerance (plasma glucose levels  7.8 mmol L−1 at 120 min post- OGTT) or hypertension (all  130/80 mmHg at baseline). In response to the glucose drink, and in comparison to subjects with normal weight, we observed in subjects with OW/OB a trend towards increased plasma insulin levels (+7445 ± 4858 vs. +4968 ±  1924 mU h L−1; p = 0.08), which was not seen for blood glucose (p = 0.59). Moreover, subjects with OW/OB showed impaired peripheral vasodilation, diminished heart rate and myocardial contractility responses but increased peripheral pulse pressure (all p   0.05). Conclusions Young male subjects with OW/OB, but without glucose intolerance or hypertension, showed attenuated peripheral vasodilation and diminished cardiac responses to a glucose drink

    Acquired heart block: A possible complication of patent ductus arteriosus in a preterm infant

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    A large patent ductus arteriosus (PDA) is a frequently encountered clinical problem in extremely low birth weight (ELBW) infants. It leads to an increased pulmonary blood flow and in a decreased or reversed diastolic flow in the systemic circulation, resulting in complications. Here we report a possible complication of PDA not previously published. On day 8 of life, a male ELBW infant (birth weight 650 g) born at a gestational age of 23 weeks and 3 days developed an atrioventricular block (AV block). The heart rate dropped from 168/min to 90/min, and the ECG showed a Wenckebach second-degree AV block and intraventricular conduction disturbances. Echocardiography demonstrated a PDA with a large left-to-right shunt and large left atrium and left ventricle with high contractility. Within several minutes after surgical closure of the PDA, the heart rate increased, and after 30 min the AV block had improved to a 1: 1 conduction ratio. Echocardiography after 2 h revealed a significant decrease of the left ventricular and atrial dimensions. Within 12 h, the AV block completely reversed together with the intraventricular conduction disturbances. We suggest that PDA with a large left-to-right shunt and left ventricular volume overload may lead to an AV block in an ELBW infant. Surgical closure of the PDA may be indicated. Copyright (C) 2007 S. Karger AG, Basel
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