1,064 research outputs found
Anthropometric and physiological predictors of flat-water 1000 m kayak performance in young adolescents and the effectiveness of a high volume training camp.
Our purpose was to determine the relationship of anthropometric and physiological variables with 1000m flat-water kayak (K1000) performance. A secondary purpose was to determine the effectiveness of a high volume training camp. High performance young adolescent kayakers (n=13, 8 males, 5 females, 15Ā±1 yrs) participated in this study. Testing before and after the 3-4 week training camp included anthropometric measurements (height, sitting height, arm span, and body mass), strength (1-RM: bench press and bench pull), flexibility (sit and reach), and an incremental kayak ergometer test to determine peak oxygen uptake (VO2peak) and anaerobic threshold, and an open water K1000 time trial. K1000 time was significantly correlated with height (r=-0.81; p\u3c0.01), sitting height (r=-0.85; p\u3c0.01), arm span (r=-0.87; p\u3c0.01), bench press (r=-0.92; p\u3c0.01), bench pull (r=-0.85; p\u3c0.01), VO2peak (r=-0.87; p\u3c0.01) and anaerobic threshold (r=-0.83; p\u3c0.05). Following the training camp there were no significant differences in body mass, strength, and VO2 peak, however, anaerobic threshold (33.6Ā±6.2 to 42.3Ā±8.8 mlā¢kg-1ā¢min-1, p=0.001) and K1000 (302Ā±44 to 289Ā±31 sec, p=0.007) significantly improved. The results of this study suggest that K1000 performance in young adolescent kayakers appears to require a high aerobic and strength contribution and that a high volume training camp is effective for improving anaerobic threshold and performance
Artists on the edge of the world : An integrated approach to the study of Magdalenian engraved stone plaquettes from Jersey (Channel Islands)
The Upper Palaeolithic is characterised by the appearance of iconographic expressions most often depicting animals, including anthropomorphic forms, and geometric signs. The Late Upper Palaeolithic Magdalenian saw a flourishing of such depictions, encompassing cave art, engraving of stone, bone and antler blanks and decoration of tools and weapons. Though Magdalenian settlement exists as far northwest as Britain, there is a limited range of art known from this region, possibly associated with only fleeting occupation of Britain during this period. Stone plaquettes, flat fragments of stone engraved on at least one surface, have been found in large quantities at numerous sites spanning the temporal and geographical spread of the Magdalenian, but they have been absent so far from the archaeological record of the British Isles. Between 2015 and 2018, ten fragments of stone plaquettes extensively engraved with abstract designs were uncovered at the Magdalenian site of Les Varines, Jersey, Channel Islands. In this paper, we report detailed analyses of these finds, which provide new evidence for technologies of abstract mark-making, and their significance within the lives of people on the edge of the Magdalenian world. These engraved stone fragments represent important, rare evidence of artistic expression in what is the far northern and western range of the Magdalenian and add new insight to the wider significance of dynamic practices of artistic expression during the Upper Palaeolithic
Assessment of the impact of race and proxies of socioeconomic status on the prevalence and health outcome of peripartum cardiomyopathy (PPCM) using the āAll of Usā Databank
Background: Peripartum Cardiomyopathy (PPCM) is a form of cardiomyopathy occurring during the last month of pregnancy or within months after giving birth in women with previously normal hearts. PPCM is an idiopathic systolic dysfunction that causes a reduced left ventricle ejection fraction. The estimated incidence of PPCM worldwide is 1 diagnosis out of 2,000 live births, and the causes of PPCM remain unknown. A retrospective cohort study conducted at the University of Pennsylvania Health System by Getz et al. showed that black race and socioeconomic proxies (like neighborhood disadvantage index (NDI)) were independently associated with sustained cardiac dysfunction (Getz et al., Am Heart J 2021). This study also showed that from all the components of NDI (education, high rental occupied housing, annual income below poverty line, female headed household, adults unemployed, adults on public assistance), low education and high rental occupied housing were significantly associated with sustained cardiac dysfunction. The central aim of the present project is to assess the effect of socioeconomic proxies (including NDI, lack of access to health care and food insecurity) on the prevalence of sustained cardiac dysfunction from PPCM across the US using the āAll of Usā databank. A secondary aim is to test the compliance of the All of Us database capacity to interrogate this potential association. Lastly, we aim to compare the results obtained from the All of Us database with the UK Biobank.
Methods: The All of Us databank (Ramirez et al., Patterns 2022; The All of US Research Program, NEJM 2019) will be used to conduct a retrospective cohort study to assess how proxies of socioeconomic status may affect the incidence and prevalence of sustained cardiac dysfunction from PPCM across different ethnicities in the US. The All of Us database focuses on enrolling people in the US from diverse groups that have historically been underrepresented in medical research. Therefore, it includes a more diverse population than the population targeted in the retrospective study conducted at the University of Pennsylvania in which only black women from Philadelphia, PA, were included. To further interrogate the impact that geographic location and population ethnicity may have on the prevalence of sustained cardiac dysfunction from PPCM, the results obtained from the āAll of Usā database will be compared against data obtained from the UK Biobank.
Expected Results: We expect that the socioeconomic proxies interrogated in this study will have a significant impact on the prevalence of sustained cardiac dysfunction from PPCM. Current knowledge is limited on how socioeconomic status affects sustained cardiac dysfunction resulting from PPCM. Previous studies have been done on populations restricted to small geographic areas and did not analyze factors such as food security, access to care, or disability status. Understanding how these factors affect the incidence and prevalence of sustained cardiac dysfunction from PPCM may be used to improve prevention, early diagnosis, and management of PPCM
Immunohistological detection of Chlamydia pneumoniae in the Alzheimer's disease brain
<p>Abstract</p> <p>Background</p> <p>Sporadic late-onset Alzheimer's disease (AD) appears to evolve from an interplay between genetic and environmental factors. One environmental factor that continues to be of great interest is that of <it>Chlamydia pneumoniae </it>infection and its association with late-onset disease. Detection of this organism in clinical and autopsy samples has proved challenging using a variety of molecular and histological techniques. Our current investigation utilized immunohistochemistry with a battery of commercially available anti-<it>C. pneumoniae </it>antibodies to determine whether <it>C. pneumoniae </it>was present in areas typically associated with AD neuropathology from 5 AD and 5 non-AD control brains.</p> <p>Results</p> <p>Immunoreactivity for <it>C. pneumoniae </it>antigens was observed both intracellularly in neurons, neuroglia, endothelial cells, and peri-endothelial cells, and extracellularly in the frontal and temporal cortices of the AD brain with multiple <it>C. pneumoniae</it>-specific antibodies. This immunoreactivity was seen in regions of amyloid deposition as revealed by immunolabeling with two different anti-beta amyloid antibodies. Thioflavin S staining, overlaid with <it>C. pneumoniae </it>immunolabeling, demonstrated no direct co-localization of the organism and amyloid plaques. Further, the specificity of <it>C. pneumoniae </it>labeling of AD brain sections was demonstrated using <it>C. pneumoniae </it>antibodies pre-absorbed against amyloid Ī² 1-40 and 1-42 peptides.</p> <p>Conclusions</p> <p>Anti-<it>C. pneumoniae </it>antibodies, obtained commercially, identified both typical intracellular and atypical extracellular <it>C. pneumoniae </it>antigens in frontal and temporal cortices of the AD brain. <it>C. pneumoniae</it>, amyloid deposits, and neurofibrillary tangles were present in the same regions of the brain in apposition to one another. Although additional studies are required to conclusively characterize the nature of Chlamydial immunoreactivity in the AD brain, these results further implicate <it>C. pneumoniae </it>infection with the pathogenesis of Alzheimer's disease.</p
Global coral bleaching event detection from satellite monitoring of extreme heat stress
Over the past four decades, coral bleaching events have occurred with increasing frequency and severity, directly linked to increasing ocean temperature due to climate change. For the latter half of that period, satellite monitoring by NOAA Coral Reef Watch in near real-time has provided invaluable insight into bleaching risk. Here, we describe a novel application of those products to develop basin-scale tools for tracking the development of extreme heat events that enable monitoring of global coral bleaching events. Case studies of historical extreme events (1982-2018) across the three tropical ocean basins (Indian, Pacific and Atlantic) were analysed using this basin-scale approach to identify key thresholds of heat stress extent for the definition of global bleaching. Global-scale events are apparent when all three tropical basins experience heat stress in at least 10% of reef-containing locations. An 8-month ādetection windowā was determined as the optimal period of time through which pixels exposed to heat stress should continue to be counted as part of a basin-scale event to account for seasonal variations across ocean basins. Understanding the broader context of basin-scale conditions can inform management of individual reefs, management networks and other reef stakeholders. Operationalising this product for near real-time delivery will provide an effective communication of the status of coral reefs around the world during an era of unprecedented climate threats
Detection of Bacterial Antigens and Alzheimer\u27s Disease-like Pathology in the Central Nervous System of BALB/c Mice Following Intranasal Infection with a Laboratory Isolate of Chlamydia pneumoniae
Pathology consistent with that observed in Alzheimerās disease (AD) has previously been documented following intranasal infection of normal wild-type mice with Chlamydia pneumoniae (Cpn) isolated from an AD brain (96-41). In the current study, BALB/c mice were intranasally infected with a laboratory strain of Cpn, AR-39, and brain and olfactory bulbs were obtained at 1-4 months post-infection (pi). Immunohistochemistry for amyloid beta or Cpn antigens was performed on sections from brains of infected or mock-infected mice. Chlamydia-specific immunolabeling was identified in olfactory bulb tissues and in cerebrum of AR-39 infected mice. The Cpn specific labeling was most prominent at 1 month pi and the greatest burden of amyloid deposition was noted at 2 months pi, whereas both decreased at 3 and 4 months. Viable Cpn was recovered from olfactory bulbs of 3 of 3 experimentally infected mice at 1 and 3 months pi, and in 2 of 3 mice at 4 months pi. In contrast, in cortical tissues of infected mice at 1 and 4 months pi no viable organism was obtained. At 3 months pi, only 1 of 3 mice had a measurable burden of viable Cpn from the cortical tissues. Mock-infected mice (0 of 3) had no detectable Cpn in either olfactory bulbs or cortical tissues. These data indicate that the AR-39 isolate of Cpn establishes a limited infection predominantly in the olfactory bulbs of BALB/c mice. Although infection with the laboratory strain of Cpn promotes deposition of amyloid beta, this appears to resolve following reduction of the Cpn antigen burden over time. Our data suggest that infection with the AR-39 laboratory isolate of Cpn results in a different course of amyloid beta deposition and ultimate resolution than that observed following infection with the human AD-brain Cpn isolate, 96-41. These data further support that there may be differences, possibly in virulence factors, between Cpn isolates in the generation of sustainable AD pathology
Changes in salivary estradiol predict changes in womenās preferences for vocal masculinity
Although many studies have reported that womenās preferences for masculine physical characteristics in men change systematically during the menstrual cycle, the hormonal mechanisms underpinning these changes are currently poorly understood. Previous studies investigating the relationships between measured hormone levels and womenās masculinity preferences tested only judgments of menās facial attractiveness. Results of these studies suggested that preferences for masculine characteristics in menās faces were related to either womenās estradiol or testosterone levels. To investigate the hormonal correlates of within-woman variation in masculinity preferences further, here we measured 62 womenās salivary estradiol, progesterone, and testosterone levels and their preferences for masculine characteristics in menās voices in five weekly test sessions. Multilevel modeling of these data showed that changes in salivary estradiol were the best predictor of changes in womenās preferences for vocal masculinity. These results complement other recent research implicating estradiol in womenās mate preferences, attention to courtship signals, sexual motivation, and sexual strategies, and are the first to link womenās voice preferences directly to measured hormone levels
Changes in salivary estradiol predict changes in womenās preferences for vocal masculinity
Although many studies have reported that womenās preferences for masculine physical characteristics in men change systematically during the menstrual cycle, the hormonal mechanisms underpinning these changes are currently poorly understood. Previous studies investigating the relationships between measured hormone levels and womenās masculinity preferences tested only judgments of menās facial attractiveness. Results of these studies suggested that preferences for masculine characteristics in menās faces were related to either womenās estradiol or testosterone levels. To investigate the hormonal correlates of within-woman variation in masculinity preferences further, here we measured 62 womenās salivary estradiol, progesterone, and testosterone levels and their preferences for masculine characteristics in menās voices in five weekly test sessions. Multilevel modeling of these data showed that changes in salivary estradiol were the best predictor of changes in womenās preferences for vocal masculinity. These results complement other recent research implicating estradiol in womenās mate preferences, attention to courtship signals, sexual motivation, and sexual strategies, and are the first to link womenās voice preferences directly to measured hormone levels
Effect of the look-up line on the gaze and head orientation of elite ice hockey players
A ālook-up-lineā (LUL) has been proposed for ice hockey, which is an orange 1 m (40 in) warning line (WL) painted on the ice at the base of the boards. The LUL purports to provide an early warning to players to keep their head up prior to, and as they are being checked. We determined if players looked-up more on a rink with the LUL compared to a traditional Control rink. Elite offensive (O) and defensive (D) players competed 1 vs 1, while wearing an eye tracker that recorded their quiet eye (QE) and fixation tracking (F-T) and an electro-goniometer that measured head angle. External cameras recorded skate duration during four skate phases: P1 preparation, P2 decision-making, P3 cut to boards, P4 contact. The QE was the final fixation prior to contact between O and D as they skated toward and across the WL during P3 and P4. Skate phase durations (%) did not differ by rink or rink by position. More QE and F-T occurred on the WL on the LUL rink than on the Control. The expected increase in head angle on the LUL rink did not occur during P3 or P4. Post-hoc results also showed O and D skated further from the boards on the LUL rink, suggesting the players preferred to control the puck on white ice, rather than the orange color of the LUL rink. More research is needed to determine if these results apply to the competitive setting
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