-
Holgersen Hastings opublikował 1 rok, 3 miesiące temu
This study examined the effects of racial/ethnic segregation (i.e., overrepresentation) in academic classes on belonging, fairness, intergroup attitudes, and achievement across middle school (n = 4,361; MageT1 = 11.33 years), and whether effects depended on numerical minority status in school and race/ethnicity. Latent growth curve models revealed that experiencing more segregation than usual predicted less belonging and fairness than usual for all youth in the numerical minority, and greater in-group preference for numerical minority Whites. Academic classroom segregation throughout middle school predicted less steep declines in in-group preference for adolescents in the numerical minority, and declines in achievement for African American numerical minority youth. Results highlight the need to treat the racial/ethnic context as a structural and dynamic construct.Animals employ various foraging strategies along their ontogeny to acquire energy, and with varying degree of efficiencies, to support growth, maturation and subsequent reproduction events. Individuals that can efficiently acquire energy early are more likely to mature at an earlier age, as a result of faster energy gain which can fuel maturation and reproduction. We aimed to test the hypothesis that heritable resource acquisition variation that covaries with efficiency along the ontogeny would influence maturation timing of individuals. To test this hypothesis, we utilized Atlantic salmon as a model which exhibits a simple, hence trackable, genetic control of maturation age. We then monitored the variation in diet acquisition (quantified as stomach fullness and composition) of individuals with different ages, and linked it with genomic regions (haploblocks) that were previously identified to be associated with age-at-maturity. Consistent with the hypothesis, we demonstrated that one of the life-history genomic regions tested (six6) was indeed associated with age-dependent differences in stomach fullness. Prey composition was marginally linked to six6, and suggestively (but non-significantly) to vgll3 genomic regions. We further showed Atlantic salmon switched to the so-called 'feast and famine’ strategy along the ontogeny, where older age groups exhibited heavier stomach content, but that came at the expense of running on empty more often. These results suggest genetic variation underlying resource utilization may explain the genetic basis of age structure in Atlantic salmon. Given that ontogenetic diet has a genetic component and the strong spatial diversity associated with these genomic regions, we predict populations with diverse maturation age will have diverse evolutionary responses to future changes in marine food web structures.Immune cells have an uncertain function during the progression of extranodal natural killer/T-cell lymphoma (ENKTL). The present study determined the distribution, phenotype, and clinical significance of B lymphocytes in ENKTL. Immunohistochemistry indicated high infiltration of CD20+ B lymphocytes in the tumour tissues of 40% of the patients, and that a high infiltration correlated with better overall survival. Moreover, B lymphocytes had an active mature phenotype in situ and suppressed the proliferation of ENKTL cells in vitro. These results suggest that tumour infiltration of CD20+ B lymphocytes may be a new prognostic indicator for patients with ENKTL.
Altered hypothalamic-pituitary-adrenal (HPA) function and related changes in circulating glucocorticoids have been implicated in the pathogenesis of numerous diseases that involve dysregulated immune function. Glucocorticoid hormones have both direct and indirect modulatory effects on both pro- and anti-inflammatory aspects of the immune system, including granulocytic and lymphocytic leukocyte subsets. However, past findings are complicated by inconsistencies across studies in how glucocorticoids and immune markers interact and relate to disease risk. Some incongruencies are likely due to an overreliance on single-unit (e.g., HPA or one immune marker) measures, and a failure to consider ecological exposures that may shape the base levels or correspondence between these systems. Here, we test single-unit and diurnal measures of HPA axis and immune system interactions in a less-industrial ecological setting with relatively high parasite loads.
In a sample of 114 Honduran women (mean age = 36 years), morning no consistent relationships between single-unit measures of cortisol, lymphocytes or granulocytes, regardless of past parasite exposure.
Results demonstrate that the relationship between HPA function and immune modulation cannot be fully understood without an understanding of local disease ecology. These results highlight the importance of research that seeks to identify etiologies of disease across environmental contexts.
Results demonstrate that the relationship between HPA function and immune modulation cannot be fully understood without an understanding of local disease ecology. These results highlight the importance of research that seeks to identify etiologies of disease across environmental contexts.Individuals of large or dark-colored ectothermic species often have a higher reproduction and activity than small or light-colored ones. However, investments into body size or darker colors should negatively affect the fitness of individuals as they increase their growth and maintenance costs. Thus, it is unlikely that morphological traits directly affect species’ distribution and abundance. Yet, this simplification is frequently made in trait-based ecological analyses. Here, we integrated the energy allocation strategies of species into an ecophysiological framework to explore the mechanisms that link species’ morphological traits and population dynamics. We hypothesized that the effects of morphological traits on species’ distribution and abundance are not direct but mediated by components of the energy budget and that species can allocate more energy towards dispersal and reproduction if they compensate their energetic costs by reducing mobility costs or increasing energy uptake. To classify species’ energological traits alone and ignoring these differences can lead to false mechanistic conclusions. Therefore, our findings highlight the potential of integrating proxies for species’ energy allocation strategies into trait-based models not only for understanding the physiological mechanisms underlying variation in species’ distribution and abundance, but also for improving predictions of the population dynamics of species.
Evidence is required to quantify the population-level effects of endoscopic screening for esophageal squamous cell carcinoma (ESCC). The objective of this study was to evaluate the long-term effectiveness of 1-time endoscopic ESCC screening in a Chinese rural population.
This community-based cohort study was based on an existing esophageal cancer screening program in Feicheng City, China. The screening group consisted of all permanent residents aged 40 to 69 years in 17 villages who were screened during 2006 through 2009, and the control group consisted of residents in another 43 villages who were not yet covered by the screening program. Residents in the remaining 511 villages were defined as the total population control. The cumulative incidence and mortality of ESCC and the observed and expected numbers of ESCC cases and deaths during the follow-up period (2010-2018) were calculated and compared.
After a 9-year follow-up, the screening group (n=8460) revealed reductions of 20% (relative risk, 0.80; 95% CI, 0.66-0.97) and 32% (relative risk, 0.68; 95% CI, 0.52-0.89) in ESCC cumulative incidence and mortality, respectively, compared with the control group (n=20,468). Endoscopic screening prevented 0.41% of the population (attributable risk, 0.41%; 95% CI, 0.07%-0.75%) from ESCC occurrence and 0.38% (attributable risk, 0.38%; 95% CI, 0.14%-0.62%) from ESCC-related death. In the screening group, reductions of 43% (standardized incidence ratio, 0.57; 95% CI, 0.48-0.67) and 45% (standardized mortality ratio, 0.55; 95% CI, 0.44-0.69) were found in the observed cumulative cases and deaths, respectively, compared with the expected cases and deaths.
One-time endoscopic screening was associated with a significant and consistent reduction in ESCC incidence and mortality among individuals aged 40 to 69 years in high-risk areas.
One-time endoscopic screening was associated with a significant and consistent reduction in ESCC incidence and mortality among individuals aged 40 to 69 years in high-risk areas.One way children are remarkable learners is that they learn from others. Critically, children are selective when assessing from whom to learn, particularly in the domain of word learning. We conducted an analysis of children’s selective word learning, reviewing 63 papers on 6,525 participants. Children’s ability to engage in selective word learning appeared to be present in the youngest samples surveyed. Their more metacognitive understanding that epistemic competence indicates reliability or that others are good sources of knowledge has more of a developmental trajectory. We also found that various methodological factors used to assess children influence performance. We conclude with a synthesis of theoretical accounts of how children learn from others.Most animals are visually oriented, and their eyes provide their 'window to the world’. Eye size correlates positively with visual performance, because larger eyes can house larger pupils that increase photon catch and contrast discrimination, particularly under dim light, which have positive effects on behaviours that enhance fitness, including predator avoidance and foraging. Recent studies have linked predation risk to selection for larger eyes and pupils, and such changes should be of importance for the majority of teleost fishes as they have a pupil that is fixed in size (eyes lack a pupillary sphincter muscle) and, hence, do not respond to changes in light conditions. Here, we quantify eye and pupil size of individual crucian carp, a common freshwater fish, following controlled manipulations of perceived predation risk (presence/absence). We also tested if crucian carp responded to increased predation risk by shifts in diel activity patterns. We found that crucian carp show phenotypic plasticity with regards to pupil size, but not eye size, as pupil size increased when exposed to predators (pike). Predator-exposed crucian carp also shifted from diurnal to nocturnal activity. Using a modelling exercise, we moreover show that the plastically enlarged pupils significantly increase visual range, especially for small objects under dim light conditions. Overall, our results provide compelling evidence for predator-induced pupil enlargement resulting in enhanced visual capabilities in a teleost fish. Pupil size plasticity in combination with the observed shift towards nocturnal activity may allow for efficient foraging also under dark conditions when predation risk from diurnal and visually oriented predators is reduced. The data highlight the powerful role of predation risk for eye development and evolution.
The primary aim of this study was to describe the insertion sites of the ligaments holding the flexor digitorum profundus and superficialis muscles (flexor ridges) in proximal phalanges 2-5 of African apes and modern humans. To interpret differences in flexor ridge size based on general behavioral differences among taxa.
We analyzed 3D models of manual proximal phalanges 2-5 from 29 gorillas (Gorilla beringei and Gorilla gorilla), 30 chimpanzees (Pan troglodytes) and 36 recent modern humans. Flexor ridges (mm
) were compared within and across genera.
Gorillas and chimpanzees had larger flexor ridges for phalanges 2-4 than humans and this difference subsists when controlling for body size. Each genus had a unique insertion size pattern across the digits, with the most heterogeneous pattern found in chimpanzees, followed by humans, and lastly gorillas. These patterns corresponded strongly to the differences in the size of the phalanges within each genus, except for phalanx 5 in humans, which had a larger flexor ridge than expected.


