Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.024
Filtrar
1.
J Exp Biol ; 225(Suppl_1)2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35258614

RESUMO

The magnitude of many kinds of biological traits relates strongly to body size. Therefore, a first step in comparative studies frequently involves correcting for effects of body size on the variation of a phenotypic trait, so that the effects of other biological and ecological factors can be clearly distinguished. However, commonly used traditional methods for making these body-size adjustments ignore or do not completely separate the causal interactive effects of body size and other factors on trait variation. Various intrinsic and extrinsic factors may affect not only the variation of a trait, but also its covariation with body size, thus making it difficult to remove completely the effect of body size in comparative studies. These complications are illustrated by several examples of how body size interacts with diverse developmental, physiological, behavioral and ecological factors to affect variation in metabolic rate both within and across species. Such causal interactions are revealed by significant effects of these factors on the body-mass scaling slope of metabolic rate. I discuss five possible major kinds of methods for removing body-size effects that attempt to overcome these complications, at least in part, but I hope that my Review will encourage the development of other, hopefully better methods for doing so.


Assuntos
Biologia , Tamanho Corporal/fisiologia , Fenótipo
2.
Proc Natl Acad Sci U S A ; 119(5)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35074877

RESUMO

The appearance of Homo erectus shortly after 2.0 Ma is widely considered a turning point in human dietary evolution, with increased consumption of animal tissues driving the evolution of larger brain and body size and a reorganization of the gut. An increase in the size and number of zooarchaeological assemblages after the appearance of H. erectus is often offered as a central piece of archaeological evidence for increased carnivory in this species, but this characterization has yet to be subject to detailed scrutiny. Any widespread dietary shift leading to the acquisition of key traits in H. erectus should be persistent in the zooarchaeological record through time and can only be convincingly demonstrated by a broad-scale analysis that transcends individual sites or localities. Here, we present a quantitative synthesis of the zooarchaeological record of eastern Africa from 2.6 to 1.2 Ma. We show that several proxies for the prevalence of hominin carnivory are all strongly related to how well the fossil record has been sampled, which constrains the zooarchaeological visibility of hominin carnivory. When correcting for sampling effort, there is no sustained increase in the amount of evidence for hominin carnivory between 2.6 and 1.2 Ma. Our observations undercut evolutionary narratives linking anatomical and behavioral traits to increased meat consumption in H. erectus, suggesting that other factors are likely responsible for the appearance of its human-like traits.


Assuntos
Tamanho Corporal/fisiologia , Carnivoridade/fisiologia , Arqueologia/métodos , Evolução Biológica , Encéfalo/fisiologia , Dieta/métodos , Fósseis , Humanos
3.
Biol Rev Camb Philos Soc ; 97(2): 679-707, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34908228

RESUMO

The notion that men are more variable than women has become embedded into scientific thinking. For mental traits like personality, greater male variability has been partly attributed to biology, underpinned by claims that there is generally greater variation among males than females in non-human animals due to stronger sexual selection on males. However, evidence for greater male variability is limited to morphological traits, and there is little information regarding sex differences in personality-like behaviours for non-human animals. Here, we meta-analysed sex differences in means and variances for over 2100 effects (204 studies) from 220 species (covering five broad taxonomic groups) across five personality traits: boldness, aggression, activity, sociality and exploration. We also tested if sexual size dimorphism, a proxy for sex-specific sexual selection, explains variation in the magnitude of sex differences in personality. We found no significant differences in personality between the sexes. In addition, sexual size dimorphism did not explain variation in the magnitude of the observed sex differences in the mean or variance in personality for any taxonomic group. In sum, we find no evidence for widespread sex differences in variability in non-human animal personality.


Assuntos
Comportamento Animal/classificação , Personalidade , Caracteres Sexuais , Agressão , Animais , Comportamento Animal/fisiologia , Tamanho Corporal/fisiologia , Feminino , Humanos , Masculino , Personalidade/classificação , Personalidade/fisiologia , Fenótipo
4.
Sci Rep ; 11(1): 23470, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873242

RESUMO

Marine reserves are known to impact the biomass, biodiversity, and functions of coral reef fish communities, but the effect of protective management on fish traits is less explored. We used a time-series modelling approach to simultaneously evaluate the abundance, biomass, and traits of eight fish families over a chronosequence spanning 44 years of protection. We constructed a multivariate functional space based on six traits known to respond to management or disturbance and affect ecosystem processes: size, diet, position in the water column, gregariousness, reef association, and length at maturity. We show that biomass increased with a log-linear trend over the time-series, but abundance only increased after 20 years of closure, and with more variation among reserves. This difference is attributed to recovery rates being dependent on body sizes. Abundance-weighted traits and the associated multivariate space of the community change is driven by increased proportions over time of the trait categories: 7-15 cm body size; planktivorous; species low in the water column; medium-large schools; and species with high levels of reef association. These findings suggest that the trait compositions emerging after the cessation of fishing are novel and dynamic.


Assuntos
Peixes/crescimento & desenvolvimento , Peixes/fisiologia , Animais , Biodiversidade , Biomassa , Tamanho Corporal/fisiologia , Conservação dos Recursos Naturais/métodos , Recifes de Corais , Ecossistema , Fenótipo
5.
PLoS One ; 16(11): e0260136, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34843528

RESUMO

The study examined if maturity status bio-banding reduces within-group variance in anthropometric, physical fitness and functional movement characteristics of 319, under-14 and under-15 players from 19 UK professional soccer academies. Bio-banding reduced the within-bio-banded group variance for anthropometric values, when compared to an aggregated chronological banded group (chronological: 5.1-16.7%CV; bio-banded: 3.0-17.3%CV). Differences between these bio-banded groups ranged from moderate to very large (ES = 0.97 to 2.88). Physical performance variance (chronological: 4.8-24.9%CV; bio-banded: 3.8-26.5%CV) was also reduced with bio-banding compared to chronological aged grouping. However, not to the same extent as anthropometric values with only 68.3% of values reduced across banding methods compared to 92.6% for anthropometric data. Differences between the bio-banded groups physical qualities ranged from trivial to very large (ES = 0.00 to 3.00). The number of functional movement metrics and %CV reduced by bio-banding was lowest within the 'circa-PHV' groups (11.1-44.4%). The proportion of players achieving the threshold value score of ≥ 14 for the FMS™ was highest within the 'post-PHV' group (50.0-53.7%). The use of maturity status bio-banding can create more homogenous groups which may encourage greater competitive equity. However, findings here support a bio-banding maturity effect hypothesis, whereby maturity status bio-banding has a heightened effect on controlling for characteristics which have a stronger association to biological growth.


Assuntos
Antropometria/métodos , Atletas/classificação , Futebol/fisiologia , Academias e Institutos , Adolescente , Atletas/psicologia , Estatura/fisiologia , Tamanho Corporal/fisiologia , Confiabilidade dos Dados , Coleta de Dados , Humanos , Masculino , Aptidão Física/fisiologia , Desempenho Físico Funcional
6.
PLoS One ; 16(11): e0259369, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34739492

RESUMO

Lystrosaurus was one of the few tetrapods to survive the Permo-Triassic mass extinction, the most profound biotic crisis in Earth's history. The wide paleolatitudinal range and high abundance of Lystrosaurus during the Early Triassic provide a unique opportunity to investigate changes in growth dynamics and longevity following the mass extinction, yet most studies have focused only on species that lived in the southern hemisphere. Here, we present the long bone histology from twenty Lystrosaurus skeletal elements spanning a range of sizes that were collected in the Jiucaiyuan Formation of northwestern China. In addition, we compare the average body size of northern and southern Pangean Triassic-aged species and conduct cranial geometric morphometric analyses of southern and northern taxa to begin investigating whether specimens from China are likely to be taxonomically distinct from South African specimens. We demonstrate that Lystrosaurus from China have larger average body sizes than their southern Pangean relatives and that their cranial morphologies are distinctive. The osteohistological examination revealed sustained, rapid osteogenesis punctuated by growth marks in some, but not all, immature individuals from China. We find that the osteohistology of Chinese Lystrosaurus shares a similar growth pattern with South African species that show sustained growth until death. However, bone growth arrests more frequently in the Chinese sample. Nevertheless, none of the long bones sampled here indicate that maximum or asymptotic size was reached, suggesting that the maximum size of Lystrosaurus from the Jiucaiyuan Formation remains unknown.


Assuntos
Tamanho Corporal/fisiologia , Dinossauros/anatomia & histologia , Fósseis/anatomia & histologia , Animais , China , Extinção Biológica , Paleontologia/métodos , Crânio/anatomia & histologia
7.
Sci Rep ; 11(1): 22681, 2021 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-34811418

RESUMO

Color polymorphic animals offer a unique system for studying intraspecific phenotypic responses to climate change. Discrete color morphs are easy to identify, and correlated trait responses of morphs can indicate how climate warming may facilitate long-term maintenance of polymorphisms. We use a historical dataset spanning 43 years to examine temporal shifts in color morph frequency and body size in response to climate in the Eastern Red-backed Salamander, Plethodon cinereus, which contains a widespread striped/unstriped color polymorphism. We created a pipeline to extract high-throughput trait data from fluid-preserved museum specimens where we batch-photographed salamanders, de-aggregated individual specimens from photographs, and solicited help of community scientists to score color morphs. We used a linear modeling framework that includes information about spatial population structure to demonstrate that color morph frequency and body size vary in response to climate, elevation, and over time, with an overall trend of higher frequency and decreased body size of the striped morph, but increased size of the unstriped morph. These surprising results suggest that morphs may be responding to multiple climate and geographic drivers through co-adapted morphological changes. This work highlights new practices of extracting trait data from museum specimens to demonstrate species phenotypes response to climate change.


Assuntos
Aclimatação/fisiologia , Aquecimento Global , Fenótipo , Pigmentação da Pele/fisiologia , Urodelos/fisiologia , Altitude , Animais , Biodiversidade , Tamanho Corporal/fisiologia , Lagartos/fisiologia , Fatores de Tempo
8.
Sci Rep ; 11(1): 21115, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34702922

RESUMO

Within optimality theory, an animal's home range can be considered a fitness-driven attempt to obtain resources for survival and reproduction while minimizing costs. We assessed whether brown bears (Ursus arctos) in two island populations maximized resource patches within home ranges (Resource Dispersion Hypothesis [RDH]) or occupied only areas necessary to meet their biological requirements (Temporal Resource Variability Hypothesis [TRVH]) at annual and seasonal scales. We further examined how intrinsic factors (age, reproductive status) affected optimal choices. We found dynamic patterns of space use between populations, with support for RDH and TRVH at both scales. The RDH was likely supported seasonally as a result of bears maximizing space use to obtain a mix of nutritional resources for weight gain. Annually, support for RDH likely reflected changing abundances and distributions of foods within different timber stand classes. TRVH was supported at both scales, with bears minimizing space use when food resources were temporally concentrated. Range sizes and optimal strategies varied among sex and reproductive classes, with males occupying larger ranges, supporting mate seeking behavior and increased metabolic demands of larger body sizes. This work emphasizes the importance of scale when examining animal movement ecology, as optimal behavioral decisions are scale dependent.


Assuntos
Comportamento de Retorno ao Território Vital/fisiologia , Modelos Biológicos , Comportamento Predatório/fisiologia , Ursidae/fisiologia , Animais , Tamanho Corporal/fisiologia , Ecossistema , Feminino , Masculino
10.
BMC Pregnancy Childbirth ; 21(1): 646, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556074

RESUMO

BACKGROUND: High rates of adverse pregnancy outcomes globally raise the need to understand risk factors and develop preventative interventions. The Pregnancy Outcomes in the Era of Universal Antiretroviral Treatment in Sub-Saharan Africa (POISE Study) was a prospective, observational cohort study conducted from 2016 to 2017 in Blantyre, Malawi. We examine the associations between indicators of nutritional status, specifically mid-thigh circumference (MTC) and body-mass index (BMI), and adverse pregnancy outcomes, low birth weight (LBW), preterm birth (PTB), and small-for-gestational age (SGA), in a cohort of HIV-infected and HIV-uninfected women. METHODS: Sociodemographic, clinical, laboratory, and maternal height, weight and MTC data were collected immediately before or after delivery at the Queen Elizabeth Central Hospital (QEHC) and 4 affiliated health centers in Blantyre, Malawi. LBW was defined as birth weight < 2.5 kg; PTB as gestational age < 37 weeks using Ballard score; and SGA as birth weight < 10th percentile for gestational age. Descriptive, stratified, and multivariable logistic regression were conducted using R. RESULTS: Data from 1298 women were analyzed: 614 HIV-infected and 684 HIV-uninfected. MTC was inversely associated with LBW (adjusted odds ratio [aOR] = 0.95, p = 0.03) and PTB (aOR 0.92, p < 0.001), after controlling for HIV status, age, socioeconomic status and hemoglobin. The association between MTC and SGA was (aOR 0.99, p = 0.53). Similarly, higher BMI was significantly associated with lower odds of PTB (aOR 0.90, p < 0.001), LBW (aOR 0.93, p = 0.05), and SGA (aOR 0.95, p = 0.04). CONCLUSIONS: We observed an inverse relationship between MTC and adverse pregnancy outcomes in Malawi irrespective of HIV infection. MTC performs comparably to BMI; the ease of measuring MTC could make it a practical tool in resource-constrained settings for identification of women at risk of adverse pregnancy outcomes.


Assuntos
Tamanho Corporal/fisiologia , Estado Nutricional/fisiologia , Complicações na Gravidez/epidemiologia , Coxa da Perna , Adulto , Feminino , Idade Gestacional , Infecções por HIV , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Malaui/epidemiologia , Masculino , Gravidez , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Estudos Prospectivos , Coxa da Perna/fisiologia , Adulto Jovem
11.
PLoS One ; 16(9): e0256991, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34473810

RESUMO

Furtive predation is an uncommon predation strategy within aphidophagous insects, as it can be constrained by several factors. So far, the few reported furtive predators are characterized by their small body-size, vermiform shape, and slow movement. They live within the aphid colonies, without triggering significant defensive acts, nor disrupting colony structure. In this study, we aim to determine how body-size may prevent adoption of a furtive predation strategy. For that, the American hoverfly, Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) was selected as a model species, according to the great body-size increase experienced during the larval stage. We hypothesized that smaller instars will be furtive predators, whereas larger ones will be active-searching predators. After the inoculation close to a pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) colony, several behavioral parameters of the different larval instars were recorded. The elicited aphid colony disturbance was also evaluated and compared with that of the active-searching ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), and of the furtive predator, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Aphids showed significantly fewer defensive behaviors in the presence of E. americanus larvae than in the presence of the active-searching H. axyridis. Furthermore, our results clearly indicate that body-size increase was not a limit, since the three larval instars of the American hoverfly acted as furtive predators, just like the furtive A. aphidimyza. It is the first time a furtive predatory behavior has been recorded on such a large aphidophagous predator. The obtained results provide essential information about the biology of E. americanus, a potential biological control agent of aphids.


Assuntos
Afídeos/fisiologia , Tamanho Corporal/fisiologia , Besouros/fisiologia , Dípteros/fisiologia , Comportamento Predatório/fisiologia , Animais , Agentes de Controle Biológico , Cadeia Alimentar , Larva/fisiologia , Movimento/fisiologia
12.
Commun Biol ; 4(1): 972, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400755

RESUMO

Anthropogenically-driven climate warming is a hypothesized driver of animal body size reductions. Less understood are effects of other human-caused disturbances on body size, such as urbanization. We compiled 140,499 body size records of over 100 North American mammals to test how climate and human population density, a proxy for urbanization, and their interactions with species traits, impact body size. We tested three hypotheses of body size variation across urbanization gradients: urban heat island effects, habitat fragmentation, and resource availability. Our results demonstrate that both urbanization and temperature influence mammalian body size variation, most often leading to larger individuals, thus supporting the resource availability hypothesis. In addition, life history and other ecological factors play a critical role in mediating the effects of climate and urbanization on body size. Larger mammals and species that utilize thermal buffering are more sensitive to warmer temperatures, while flexibility in activity time appears to be advantageous in urbanized areas. This work highlights the value of using digitized, natural history data to track how human disturbance drives morphological variation.


Assuntos
Tamanho Corporal/fisiologia , Clima , Traços de História de Vida , Mamíferos/fisiologia , Urbanização , Animais , América do Norte
13.
J Physiol Anthropol ; 40(1): 9, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34452641

RESUMO

Applying human biological evolution to solve topical problems of medicine and preventive cardiology was inspired by the realization of the need for clinical and experimental studies of biological (evolutionary) prerequisites in the occurrence of a pathology. Although it has been stated that there is a need to provide a full biological understanding of features, including those that increase an animal's vulnerability to diseases, unfortunately, in this regard, erectile and associated adaptations to the Earth's gravity in their physiological and pathological manifestations have not been considered. At the same time, it should be noted that humans, unlike other animal species, have the greatest vulnerability of the cardiovascular system (CVS). The latter is associated with fundamental differences in the functioning and regulation of the CVS by the influence of gravity on blood circulation in humans as upright creatures. Based on a review of comparative physiological, ontogenetic, and clinical studies from an evolutionary perspective, the idea of adaptation to the Earth's gravity when walking upright in humans is justified as an anthropogenic basis for the physiology and pathology of the cardiovascular system and hemodynamic support systems (physio-anthropology and pathological anthropology).


Assuntos
Adaptação Fisiológica/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Gravitação , Modelos Biológicos , Adolescente , Adulto , Animais , Antropologia Física , Tamanho Corporal/fisiologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Caminhada/fisiologia , Adulto Jovem
14.
Int J Obes (Lond) ; 45(12): 2539-2545, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34349227

RESUMO

BACKGROUND: Focused studies in younger to middle-aged populations have demonstrated a relationship between obesity and adverse cardiac mechanics. We examined whether measures of overall and central adiposity are associated with cardiac mechanics, assessed by speckle-tracking echocardiography, in an older population without prevalent coronary heart disease or heart failure. METHODS: Body composition was measured by anthropometry, bioelectrical impedance, and dual-energy x-ray absorptiometry among participants in the Cardiovascular Health Study, a population-based cohort of adults aged 65 years or older. Systolic and diastolic cardiac mechanics were measured with speckle-tracking analysis of echocardiograms. Multi-variable adjusted linear regression models were used to investigate associations of body composition measures and cardiac mechanics. RESULTS: Mean age for the 3525 included participants was 72.6 years, 39% were male, and 10% were black. Mean body-mass index (BMI) was 26.3 ± 4.4 kg/m2, waist circumference (WC) was 93.2 ± 12.9 cm, and waist-to-hip ratio was 0.92 ± 0.09. In fully adjusted analyses, all adiposity measures were associated with worse LV longitudinal strain, LV early diastolic strain rate, and left atrial reservoir strain; however, associations were strongest for WC and BMI (p < 0.001). When both BMI and WC were included in the same model, only WC remained associated with each cardiac strain measure. CONCLUSION: In this cross-sectional study of older adults, central obesity was most robustly associated with impaired left ventricular systolic and diastolic strain as well as left atrial strain. The adverse effects of central obesity appear to extend even into older age.


Assuntos
Composição Corporal/fisiologia , Tamanho Corporal/fisiologia , Cardiopatias/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Correlação de Dados , Estudos Transversais , Feminino , Cardiopatias/epidemiologia , Humanos , Masculino , Fatores de Risco
15.
BMC Vet Res ; 17(1): 265, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362371

RESUMO

BACKGROUND: Blood biochemistry and reference intervals help to differentiate between healthy and ill dogs as well as to provide information for the prognosis, evaluation, and monitoring; however, these intervals are often obtained from adult animals. It is essential to understand that puppies and adults are physiologically different, which justifies the need to obtain age-specific biochemical reference intervals. The aim of this research was to assess the potential effect of age, sex, body size, and their interaction on routine biochemical analytes and physiological constants (body temperature, heart rate, and respiratory rate). To carry out the research, we selected 197 healthy dogs of both sexes and different body sizes (small, medium and large) classified by age: group I (4-8 wk), group II (9-24 wk), group III (25-52 wk), and group IV (> 52 wk). The biochemical analysis included the measurement of the enzymatic activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), and the concentrations of cholesterol, triglycerides, total proteins, albumin, globulins, glucose, urea, and creatinine. Statistical analyses used analysis of variance (ANOVA) and a general linear model (GLM), which allows the comparison of multiple factors at two or more levels (p < 0.05). RESULTS: The results of this study showed that ALT, total protein, albumin, globulin, urea, creatinine, and body temperature levels were lower in puppies than in adult dogs of group IV (p < 0.05), while the enzymatic activity of ALP, LDH, glucose concentration, and heart rate were higher. Whereas sex, body size and the interaction did not show a significant effect (p > 0.05). CONCLUSIONS: Some biochemical components are influenced by age. For this reason, this manuscript contributes with additional data for the clinical interpretation of blood biochemical results in puppies.


Assuntos
Envelhecimento/fisiologia , Análise Química do Sangue/veterinária , Tamanho Corporal/fisiologia , Cães/sangue , Envelhecimento/sangue , Animais , Cães/crescimento & desenvolvimento , Cães/fisiologia , Feminino , Testes Hematológicos/veterinária , Masculino , Valores de Referência
16.
Am J Physiol Renal Physiol ; 321(3): F322-F334, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34308670

RESUMO

Low birth weight is a risk factor for chronic kidney disease, whereas adult podocyte depletion is a key event in the pathogenesis of glomerulosclerosis. However, whether low birth weight due to poor maternal nutrition is associated with low podocyte endowment and glomerulosclerosis in later life is not known. Female Sprague-Dawley rats were fed a normal-protein diet (NPD; 20%) or low-protein diet (LPD; 8%), to induce low birth weight, from 3 wk before mating until postnatal day 21 (PN21), when kidneys from some male offspring were taken for quantitation of podocyte number and density in whole glomeruli using immunolabeling, tissue clearing, and confocal microscopy. The remaining offspring were fed a normal- or high-fat diet until 6 mo to induce catch-up growth and excessive weight gain, respectively. At PN21, podocyte number per glomerulus was 15% lower in low birth weight (LPD) than normal birth weight (NPD) offspring, with this deficit greater in outer glomeruli. Surprisingly, podocyte number in LPD offspring increased in outer glomeruli between PN21 and 6 mo, although an overall 9% podocyte deficit persisted. Postnatal fat feeding to LPD offspring did not alter podometric indexes or result in glomerular pathology at 6 mo, whereas fat feeding in NPD offspring was associated with far greater body and fat mass as well as podocyte loss, reduced podocyte density, albuminuria, and glomerulosclerosis. This is the first report that maternal diet can influence podocyte endowment. Our findings provide new insights into the impact of low birth weight, podocyte endowment, and postnatal weight on podometrics and kidney health in adulthood.NEW & NOTEWORTHY The present study shows, for the first time, that low birth weight as a result of maternal nutrition is associated with low podocyte endowment. However, a mild podocyte deficit at birth did not result in glomerular pathology in adulthood. In contrast, postnatal podocyte loss in combination with excessive body weight led to albuminuria and glomerulosclerosis. Taken together, these findings provide new insights into the associations between birth weight, podocyte indexes, postnatal weight, and glomerular pathology.


Assuntos
Tamanho Corporal/fisiologia , Nefropatias/patologia , Podócitos/patologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Animais , Peso ao Nascer/fisiologia , Feminino , Rim/patologia , Glomérulos Renais/patologia , Gravidez , Ratos Sprague-Dawley
17.
Nat Commun ; 12(1): 4401, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285216

RESUMO

Phenotypic flexibility allows individuals to reversibly modify trait values and theory predicts an individual's relative degree of flexibility positively correlates with the environmental heterogeneity it experiences. We test this prediction by integrating surveys of population genetic and physiological variation with thermal acclimation experiments and indices of environmental heterogeneity in the Dark-eyed Junco (Junco hyemalis) and its congeners. We combine field measures of thermogenic capacity for 335 individuals, 22,006 single nucleotide polymorphisms genotyped in 181 individuals, and laboratory acclimations replicated on five populations. We show that Junco populations: (1) differ in their thermogenic responses to temperature variation in the field; (2) harbor allelic variation that also correlates with temperature heterogeneity; and (3) exhibit intra-specific variation in thermogenic flexibility in the laboratory that correlates with the heterogeneity of their native thermal environment. These results provide comprehensive support that phenotypic flexibility corresponds with environmental heterogeneity and highlight its importance for coping with environmental change.


Assuntos
Aclimatação/genética , Temperatura Baixa/efeitos adversos , Evolução Molecular , Passeriformes/fisiologia , Termogênese/genética , Alelos , Animais , Variação Biológica da População , Tamanho Corporal/fisiologia , Polimorfismo de Nucleotídeo Único
18.
J Pediatr Endocrinol Metab ; 34(10): 1291-1302, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34273916

RESUMO

OBJECTIVES: Growing skeleton is uniquely vulnerable to impaired mineralization in chronic kidney disease (CKD). Continued debate exists about the optimal method to adjust for body size when interpreting dual energy X-ray absorptiometry (DXA) scans in children with CKD given the burden of poor growth. The study aimed to evaluate the clinical usefulness of size-adjustment techniques of lumber-spine DXA measurements in assessing bone mineralization in children with kidney failure on maintenance hemodialysis (HD). METHODS: Case-control study included 93 children on maintenance HD (9-18 years; 48 males). Participants were subjected to spinal-DXA-scan to obtain areal bone mineral density (aBMD; g/cm2). Volumetric-BMD (vBMD; g/cm3) was mathematically estimated. Z-scores of aBMD for chronological age (aBMDZ-CA), aBMD adjusted for height age (aBMDZ-HA), and vBMDZ-score were calculated using mean and SD values of age subgroups of 442 healthy controls (7-18 years). RESULTS: In short-for-age CKD patients, aBMDZ-CA was significantly lower than vBMDZ-score, while aBMDZ-HA was significantly higher than aBMDZ-CA and vBMDZ-score. In normal height-for-age CKD patients, no significant difference between aBMDZ-scores and vBMDZ-score was detected. aBMDZ-CA was significantly lower and aBMDZ-HA was significantly higher in short-for-age compared to normal height-for-age patients without significant differences in vBMDZ-score. We observed age-related decrements in the percentage of HD patients with normal densitometric Z-scores, the effect of age was less pronounced in aBMDZ-HA than vBMDZ-score. vBMDZ-score correlated negatively with age, but not with heightZ-score. CONCLUSIONS: Estimated vBMD seems to be a convenient size-adjustment approach of spinal-DXA measurements in assessing BMD especially in older short-for-age children with CKD. aBMDZ-CA underestimates, while aBMDZ-HA overestimates BMD in such patients.


Assuntos
Tamanho Corporal/fisiologia , Densidade Óssea , Calcificação Fisiológica/fisiologia , Diálise Renal , Insuficiência Renal Crônica , Absorciometria de Fóton/métodos , Absorciometria de Fóton/normas , Adolescente , Idade de Início , Estatura/fisiologia , Calibragem , Estudos de Casos e Controles , Criança , Egito/epidemiologia , Feminino , Humanos , Região Lombossacral , Masculino , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/terapia , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/patologia
19.
Biomolecules ; 11(7)2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34201983

RESUMO

Environmental estrogen is a substance that functions as an endocrine hormone in organisms and can cause endocrine system disruption. A typical environmental estrogen, diethylstilbestrol (DES), can affect normal sexual function and organism development. However, even though the effects of different exposure stages of DES on the endocrine system and gonadal development of zebrafish juveniles are unknown, sex determination is strongly influenced by endocrine-disrupting chemicals (EDCs). From 10-90 days post fertilization (dpf), juvenile zebrafish were exposed to DES (100 and 1000 ng/L) in three different stages (initial development stage (IDS), 10-25 dpf; gonadal differentiation stage (GDS), 25-45 dpf and gonadal maturity stage (GMS), 45-60 dpf). Compared with that of IDS and GMS, the growth indicators (body length, body weight, and others) decreased significantly at GDS, and the proportion of zebrafish females exposed to 100 ng/L DES was significantly higher (by 59.65%) than that of the control; in addition, the zebrafish were biased towards female differentiation. The GDS is a critical period for sex differentiation. Our results show that exposure to environmental estrogen during the critical gonadal differentiation period not only affects the development of zebrafish, but also affects the population development.


Assuntos
Dietilestilbestrol/toxicidade , Disruptores Endócrinos/toxicidade , Estrogênios não Esteroides/toxicidade , Gônadas/efeitos dos fármacos , Diferenciação Sexual/efeitos dos fármacos , Animais , Tamanho Corporal/efeitos dos fármacos , Tamanho Corporal/fisiologia , Feminino , Masculino , Diferenciação Sexual/fisiologia , Peixe-Zebra
20.
Sci Rep ; 11(1): 15116, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34302013

RESUMO

Poor growth and disease transmission of small sea urchins Strongylocentrotus intermedius in summer greatly hamper the production efficiency of the longline culture. Reducing the adverse effects of high stocking density while maintaining high biomass is essential to address these problems. Here, we conducted a laboratory experiment to simulate the multi-layer culture for sea urchins at ambient high temperatures (from 22.2 to 24.5 °C) in summer for ~ 7 weeks. Survival, body size, lantern growth, gut weight, food consumption, Aristotle's lantern reflex, 5-hydroxytryptamine concentration, pepsin activity and gut morphology were subsequently evaluated. The present study found that multi-layer culture led to significantly larger body size than those without multi-layer culture (the control group). This was probably because of the greater feeding capacity (indicated by lantern growth and Aristotle's lantern reflex) and food digestion (indicated by morphology and pepsin activity of gut) in the multi-layer cultured sea urchins. These results indicate that multi-layer is an effective approach to improving the growth efficiency of sea urchins at high temperatures. We assessed whether eliminating interaction further improve these commercially important traits of sea urchins in multi-layer culture. This study found that eliminating interactions displayed greater body size and Aristotle's lantern reflex than those not separated in the multi-layer culture. This approach also significantly reduced the morbidity compared with the control group. These novel findings indicate that eliminating interactions in multi-layer culture greatly contributes to the growth and disease prevention of sea urchins at high temperatures. The present study establishes a new technique for the longline culture of sea urchins in summer and provides valuable information into the longline culture management of other commercially important species (e.g. scallops, abalones and oysters).


Assuntos
Ouriços-do-Mar/fisiologia , Strongylocentrotus/fisiologia , Animais , Tamanho Corporal/fisiologia , Alimentos , Temperatura Alta , Fenótipo , Estações do Ano
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...