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1.
Naturwissenschaften ; 110(1): 4, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36715746

RESUMO

Despite nearly 200 years of scientific collecting and study, none of the extinct, bipedal, predatory, theropod dinosaurs have been reliably shown to exceed 12 m in length. Using digital 3D models of theropods with lengths spanning 80 cm to 12 m, their body masses were found to scale to the 3.5 power of body lengths. The lateral area of the pelvis and the cross-sectional area of the tail base of these animals corresponds to the cross-sectional areas of key muscle groups important for balance and locomotion, and both scale to the 2.4 power of body length. Body accelerations in the lateral and forward directions are, using F = ma, given by dividing muscle area (force proxy) by body mass. Plotting these acceleration estimates against body length shows them to decrease exponentially. The largest theropods with body lengths of 10-12 m have less than 10% of the acceleration capacity of the smaller forms. The distinct lack of fossil remains of theropods demonstrably longer than 12 m suggests that the theropod body plan had an upper size limit based on a minimum acceleration threshold. Rotational inertia of the theropod body was found to be proportional to body length raised to the 5.5 power, and with increasing length, the capacity for agility would rapidly diminish. The tight relationship between theropod pelvic area and body length allows for the estimation of body lengths of specimens lacking complete axial skeletons, and this is done for four, large, well-preserved pelves.


Assuntos
Dinossauros , Animais , Dinossauros/anatomia & histologia , Tamanho Corporal , Fósseis , Osso e Ossos , Evolução Biológica
2.
Behav Ther ; 54(1): 14-28, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36608971

RESUMO

This study investigated a novel technique to improve body image among women who have undergone bariatric surgery-namely, by having them focus on their body functionality (everything the body can do, rather than how it looks). Participants were 103 women (Mage = 46.61) who had undergone bariatric surgery 5-7 months prior to the study. They were randomized to the 1-week online intervention, comprising three functionality-focused writing exercises (Expand Your Horizon; Alleva et al., 2015), or to a wait-list control group. Body appreciation, appearance and functionality satisfaction, body awareness, self-objectification, self-esteem, and self-kindness were assessed at pretest, posttest, and at 1-week and 3-month follow-up. Multilevel modeling analyses showed that, compared to the control, the intervention group experienced improved body appreciation at posttest, and these improvements persisted at both follow-ups. These findings were nonsignificant when intent-to-treat analyses were performed. Both available case and intent-to-treat analyses showed that all participants experienced improvements in facets of body image across time. Qualitative analyses of participants' responses to the intervention writing exercises provided more insight. Via coding reliability thematic analysis, we identified 11 themes that together provide evidence that intervention participants experienced facets of a more positive body image, while also facing challenges to their body image and well-being. Together, findings suggest that focusing on body functionality may contribute to improved body image among women who have undergone bariatric surgery, but effects may be nuanced compared to prior functionality research among general samples of women. The study was registered retrospectively (ClinicalTrials.gov; identifier NCT04883268).


Assuntos
Cirurgia Bariátrica , Imagem Corporal , Humanos , Feminino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tamanho Corporal
3.
Physiol Biochem Zool ; 96(1): 75-85, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36626843

RESUMO

AbstractLaboratory animal models have shown that blood serotonin levels reflect consistent individual differences in behavioral decision-making and maternal behavior. Serotonin could also help to understand intraspecific variation in reproductive strategies, although the mechanisms are poorly understood. In this study, the relationships of plasma serotonin with breeding parameters and parental behavior were examined in wild great tits (Parus major). Females who laid eggs earlier had higher levels of serotonin in the second half of the nestling period, while no significant relationship of serotonin with clutch size, brood size, and body size was detected. In males, serotonin levels were negatively related to clutch size and brood size and positively related to body size. The association of serotonin with provisioning behavior was sex specific, and acute fear stress induced by a predator presentation did not change this relationship. Food provisioning was positively related to size-corrected serotonin levels in females and negatively related to size-corrected serotonin levels in males. These results suggest that peripheral serotonin is a sensitive marker of parental behavior and reproductive effort in wild birds, while the mechanisms linking this neurotransmitter to reproduction are probably mediated by interplay between the serotonergic system, sex hormones, and other neurotransmitters.


Assuntos
Passeriformes , Serotonina , Feminino , Masculino , Animais , Reprodução , Tamanho da Ninhada , Tamanho Corporal
4.
Evolution ; 77(1): 155-165, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36622778

RESUMO

Character displacement is considered a key driver of evolutionary divergence and adaptation. Few examples of reproductive character displacement with a narrow contact zone have been identified. We examined the genetic structure, body length variation, and genital morphology in the contact and allopatric areas of Platycerus takakuwai and P. viridicuprus to investigate character displacement and gene flow. In the contact area, the species identifications based on endophallic morphology and nuclear genes were identical, whereas mitochondrial gene did not exhibit a perfect match. This incongruence suggests that interspecific hybridization followed by the mitochondrial introgression has likely occurred during historical secondary contact. The species are essentially parapatric in contact area, co-occurring at only one of 28 adjacent sampling sites despite being flying species, and no hybrids based on morphology have been found, which indicates a strongly exclusive distribution. The results showed that the body length variation was consistent with character displacement after controlling for variation along geographic and environmental gradients. Interspecific body size differentiation may have evolved to reduce incorrect mating between the species. Moreover, selective pressure caused by reproductive interference between the two species may act on body size that have likely resulted in strongly exclusive distribution at the edge of their ranges.


Assuntos
Besouros , Animais , Evolução Biológica , Reprodução , Hibridização Genética , Tamanho Corporal
5.
PLoS One ; 18(1): e0280223, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662685

RESUMO

Residents of socioeconomically disadvantaged neighbourhoods have higher rates of overweight and obesity and chronic disease than their counterparts from advantaged neighbourhoods. This study assessed whether associations between neighbourhood disadvantage and measured body mass index (BMI) and waist circumference, are accounted for by obesogenic environments (i.e., residential distance to the Central Business District [CBD], supermarket availability, access to walkable destinations). The study used 2017-18 National Health Survey data for working-aged adults (aged ≥18 years, n = 9,367) residing in 3,454 neighbourhoods across Australia's state and territory capital cities. In five of eight cities (i.e., Sydney, Melbourne, Brisbane, Adelaide, and Perth) residents of disadvantaged neighbourhoods had significantly higher BMI and a larger waist circumference than residents of more advantaged areas. There was no association between neighbourhood disadvantage and body size in Hobart, Darwin, and Canberra. Associations between neighbourhood disadvantage and body size were partially explained by neighbourhood differences in distance to the CBD but not supermarket availability or walkable amenities. The results of this study point to the role of urban design and city planning as mechanisms for addressing social and economic inequities in Australia's capital cities, and as solutions to this country's overweight and obesity epidemic and associated rising rates of chronic disease.


Assuntos
Sobrepeso , Adulto , Humanos , Adolescente , Pessoa de Meia-Idade , Cidades , Fatores Socioeconômicos , Tamanho Corporal , Características de Residência , Obesidade/epidemiologia , Características da Vizinhança , Austrália/epidemiologia
6.
PeerJ ; 11: e14800, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36718452

RESUMO

Body size is often hypothesized to facilitate or constrain morphological diversity in the cranial, appendicular, and axial skeletons. However, how overall body shape scales with body size (i.e., body shape allometry) and whether these scaling patterns differ between ecological groups remains poorly investigated. Here, we test whether and how the relationships between body shape, body size, and limb lengths differ among species with different locomotor specializations, and describe the underlying morphological components that contribute to body shape evolution among squirrel (Sciuridae) ecotypes. We quantified the body size and shape of 87 squirrel species from osteological specimens held at museum collections. Using phylogenetic comparative methods, we first found that body shape and its underlying morphological components scale allometrically with body size, but these allometric patterns differ among squirrel ecotypes: chipmunks and gliding squirrels exhibited more elongate bodies with increasing body sizes whereas ground squirrels exhibited more robust bodies with increasing body size. Second, we found that only ground squirrels exhibit a relationship between forelimb length and body shape, where more elongate species exhibit relatively shorter forelimbs. Third, we found that the relative length of the ribs and elongation or shortening of the thoracic region contributes the most to body shape evolution across squirrels. Overall, our work contributes to the growing understanding of mammalian body shape evolution and how it is influenced by body size and locomotor ecology, in this case from robust subterranean to gracile gliding squirrels.


Assuntos
Evolução Biológica , Sciuridae , Animais , Filogenia , Sciuridae/anatomia & histologia , Ecótipo , Tamanho Corporal
7.
Proc Natl Acad Sci U S A ; 120(4): e2209482119, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36649422

RESUMO

Evidence for a reduction in stature between Mesolithic foragers and Neolithic farmers has been interpreted as reflective of declines in health, however, our current understanding of this trend fails to account for the complexity of cultural and dietary transitions or the possible causes of phenotypic change. The agricultural transition was extended in primary centers of domestication and abrupt in regions characterized by demic diffusion. In regions such as Northern Europe where foreign domesticates were difficult to establish, there is strong evidence for natural selection for lactase persistence in relation to dairying. We employ broad-scale analyses of diachronic variation in stature and body mass in the Levant, Europe, the Nile Valley, South Asia, and China, to test three hypotheses about the timing of subsistence shifts and human body size, that: 1) the adoption of agriculture led to a decrease in stature, 2) there were different trajectories in regions of in situ domestication or cultural diffusion of agriculture; and 3) increases in stature and body mass are observed in regions with evidence for selection for lactase persistence. Our results demonstrate that 1) decreases in stature preceded the origins of agriculture in some regions; 2) the Levant and China, regions of in situ domestication of species and an extended period of mixed foraging and agricultural subsistence, had stable stature and body mass over time; and 3) stature and body mass increases in Central and Northern Europe coincide with the timing of selective sweeps for lactase persistence, providing support for the "Lactase Growth Hypothesis."


Assuntos
Agricultura , Tamanho Corporal , Indústria de Laticínios , Humanos , Aceleração , Europa (Continente) , Lactase
8.
Mol Phylogenet Evol ; 178: 107635, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36208694

RESUMO

Most of the unique and diverse vertebrate fauna that inhabits Madagascar derives from in situ diversification from colonisers that reached this continental island through overseas dispersal. The endemic Malagasy Scincinae lizards are amongst the most species-rich squamate groups on the island. They colonised all bioclimatic zones and display many ecomorphological adaptations to a fossorial (burrowing) lifestyle. Here we propose a new phylogenetic hypothesis for their diversification based on the largest taxon sampling so far compiled for this group. We estimated divergence times and investigated several aspects of their diversification (diversification rate, body size and fossorial lifestyle evolution, and biogeography). We found that diversification rate was constant throughout most of the evolutionary history of the group, but decreased over the last 6-4 million years and independently from body size and fossorial lifestyle evolution. Fossoriality has evolved from fully quadrupedal ancestors at least five times independently, which demonstrates that even complex morphological syndromes - in this case involving traits such as limb regression, body elongation, modification of cephalic scalation, depigmentation, and eyes and ear-opening regression - can evolve repeatedly and independently given enough time and eco-evolutionary advantages. Initial diversification of the group likely occurred in forests, and the divergence of sand-swimmer genera around 20 Ma appears linked to a period of aridification. Our results show that the large phenotypic variability of Malagasy Scincinae has not influenced diversification rate and that their rich species diversity results from a constant accumulation of lineages through time. By compiling large geographic and trait-related datasets together with the computation of a new time tree for the group, our study contributes important insights on the diversification of Malagasy vertebrates.


Assuntos
Lagartos , Animais , Filogenia , Serpentes , Tamanho Corporal , Madagáscar
9.
Gen Comp Endocrinol ; 330: 114163, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36356644

RESUMO

In altricial animals, young are completely dependent on parents for provisioning. The ability to outcompete siblings to receive parental provisioning has clear fitness benefits, and may be mediated by hormones that influence growth. We analyzed the effects of insulin-like growth factor 1 (IGF-1) on body size, growth, and sibling rivalry in eastern bluebirds (Sialia sialis). To determine whether IGF-1 is upregulated in response to the competitive environment, we manipulated brood sizes and examined the effect on IGF-1 levels, nestling body size, growth rate, and behavior. In a separate experiment, we injected nestlings with exogenous IGF-1 to study its impacts on body size, growth rate, and sibling competition. Brood size manipulation did not influence endogenous IGF-1 levels, but male nestlings with higher IGF-1 levels early in the nestling period tended to have greater mass gain than males with lower IGF-1 levels. Nestlings with higher IGF-1 levels also tended to be fed more frequently by parents. In the injection experiment, IGF-1 injected individuals tended to be heavier than vehicle injected young by the end of the nestling period, which suggests that IGF-1 can influence mass gain in bluebirds. IGF-1 has been proposed to be a mediator of life-history strategies and post-hatching behavior. Our results suggest that although bluebird nestlings do not adaptively elevate IGF-1 in response to the presence or number of siblings, IGF-1 may influence growth during the nestling period. These findings shed light on sibling competition, life history strategies, and the hormones that underlie them.


Assuntos
Fator de Crescimento Insulin-Like I , Aves Canoras , Masculino , Animais , Humanos , Irmãos , Tamanho Corporal
10.
Braz. j. biol ; 83: e250235, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339353

RESUMO

Abstract The Neotropical freshwater cladoceran Bergamina lineolata (Sars, 1901) was found in a small temporal pond in the Magdalena department. Hitherto, it has been reported in Brazil and El Salvador. It was originally described as Alonella lineolata by Sars, 1901 from Brazil and then placed to the genus Bergamina by Elmoor-Loureiro et al. (2013). This is the first record of this species in Colombia. B. lineolata can be identified by a unique combination of characters including: 1) a remarkably large and oblong postabdomen, with three denticles on distal corner; 2) basal spine of the claw very short, length less than the half claw diameter at base; 3) IDL with two setae shorter than ODL seta, armed with fine setules unilaterally in terminal half; 4) endite 1 of trunk limb I with a long smooth seta between endites 1 and 2.


Resumo O cladócero neotropical de água doce Bergamina lineolata (Sars, 1901) foi encontrado em uma pequena lagoa temporária no departamento de Magdalena, na Colômbia. Até o momento, havia sido relatado no Brasil e em El Salvador. Foi originalmente descrito como Alonella lineolata por Sars, 1901 no Brasil, e, em seguida, colocado no gênero Bergamina por Elmoor-Loureiro et al. (2013). Esse é o primeiro registro dessa espécie na Colômbia. B. lineolata pode ser identificada por uma combinação única de caracteres, incluindo: 1) um pós-abdômen notavelmente grande e oblongo, com três dentículos no ângulo distal; 2) espinho basal da garra muito curto, comprimento menor que o diâmetro da metade da garra na base; 3) IDL com duas cerdas mais curtas que cerdas ODL, armadas com sétulas finas unilateralmente na metade terminal; e 4) endito 1 do toracópodo I com uma longa cerda lisa entre os enditos 1 e 2.


Assuntos
Animais , Cladóceros , Brasil , Colômbia , Tamanho Corporal , Distribuição Animal
11.
J Radiol Prot ; 43(1)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36538816

RESUMO

Phantoms of different sizes, as indicated by several studies, have a significant impact on the accuracy of dose calculations. Therefore, it is necessary to establish a body-size-dependent series of Chinese standing adult phantoms to improve the accuracy of radiation dosimetry. In this study, the Chinese reference polygon-mesh phantomsCRAM_S/CRAF_Shave been refined and a method for automatically constructing lymph nodes in a mesh phantom has been proposed. Then, based on the refined phantoms, this study has developed 42 anthropometric standing adult computational phantoms, 21 models for each gender, with a height range of 145-185 cm and weight as a function of body mass index corresponding to healthy, overweight and obese. The parameters were extracted from the National Occupational Health Standards (GBZ) document of the People's Republic of China, which covers more than 90% of the Chinese population. For a given body height and mass, phantoms are scaled in proportion to a factor reflecting the change of adipose tissue and the internal organs. The remainder is adjusted manually to match the target parameters. In addition, the constructed body-size-specific phantoms have been implemented in the in-house THUDose Monte Carlo code to calculate the dose coefficients (DCs) for external photon exposures in the antero-posterior, postero-anterior and right lateral geometries. The results showed that organ DCs varied significantly with body size at low energies (<2MeV) and high energies (>8MeV) due to the differences in anatomy. Organ DC differences between a phantom of a given size and a reference phantom vary by up to 40% for the same height and up to 400% for the whole phantom. The influence of body size differences on the DCs demonstrates that the body-size-dependent Chinese adult phantoms hold great promise for a wide range of applications in radiation dosimetry.


Assuntos
Proteção Radiológica , Humanos , Adulto , Radiometria/métodos , Tamanho Corporal , Estatura , Imagens de Fantasmas , Método de Monte Carlo , Doses de Radiação
12.
Epidemiology ; 34(1): 80-89, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36455248

RESUMO

BACKGROUND: Prenatal nonessential metals may contribute to postnatal adiposity, whereas essential metals may have metabolic benefits. We evaluated joint and individual associations between prenatal metals and childhood adiposity. METHODS: We measured concentrations of six nonessential (arsenic, barium, cadmium, cesium, lead, and mercury) and four essential (magnesium, manganese, selenium, and zinc) metals in first trimester maternal blood from a prebirth cohort. We collected anthropometric measures in early childhood, mid-childhood, and early adolescence including subscapular+tricep skinfold thickness (mm) (N = 715-859), waist circumference (cm) (N = 717-882), and body mass index (BMI) (z-score) (N = 716-875). We measured adiposity in mid-childhood and early adolescence using bone densitometry total- and trunk- fat mass index (kg/m 2 ) (N = 511-599). We estimated associations using adjusted quantile g-computation and linear regression. RESULTS: The nonessential metal mixture was associated with higher total (ß = 0.07, 95% CI = 0.01, 0.12) and trunk fat mass index (ß = 0.12, CI = 0.02, 0.22), waist circumference (ß = 0.01, CI = 0.00, 0.01), and BMI (ß = 0.24, CI = 0.07, 0.41) in mid-childhood, and total fat mass index (ß = 0.07, CI = 0.01, 0.14), and BMI (ß = 0.19, CI = 0.02, 0.37) in early adolescence. The essential metal mixture was associated with lower early adolescence total-(ß = -0.11, CI = -0.17, -0.04) and trunk- fat mass index (ß = -0.13, CI = -0.21, -0.05), subscapular+tricep skinfold thickness (ß = -0.02, CI = -0.03, -0.00), waist circumference (ß = -0.003, CI = -0.01, -0.00), and BMI (ß = -0.16, CI = -0.28, -0.04). Cadmium and cesium were individually associated with childhood adiposity at different timepoints. CONCLUSIONS: Prenatal first-trimester essential metals were associated with lower childhood adiposity, whereas nonessential metals were associated with higher adiposity into adolescence.


Assuntos
Adiposidade , Obesidade Pediátrica , Pré-Escolar , Adolescente , Feminino , Gravidez , Humanos , Criança , Primeiro Trimestre da Gravidez , Cádmio , Tamanho Corporal , Metais , Obesidade Pediátrica/epidemiologia
13.
Zoology (Jena) ; 156: 126065, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36502738

RESUMO

Congeneric species often coexist in sympatry using behavioral and morphological adaptations to reduce competition and interspecific interference, but reproductive patterns behind coexistence remain unknown. We analyzed the gonadal morphology and development, reproductive cycle, and population structure of two sympatric congeneric fishes to evaluate the degree of overlap and differentiation of the reproductive biology between species in a Neotropical river. Development of testes and ovaries were similar between species, both showing asynchronous gonadal development, large diameter of gametes and synthesis of mucosubstances by follicle cells to form adhesive eggs. Although the morphometry of germ cells did not present differences, the zona radiata of mature eggs in Hypostomus garmani was markedly thicker than H. francisci, which suggests different spawning habitats. Both species have greater reproductive activity in the rainy season, concomitant with increase in water temperature, however H. garmani initiates and ends its reproduction earlier than H. francisci, indicating a differentiation of reproductive periods. Sexually mature males and females of H. francisci reproduced at a larger mean size then H. garmani. The two congeneric species had a similar abundance and sex ratios in the study area. Results show that although the species exhibited broad overlap of reproductive traits, a spatial and temporal differentiation of the reproductive biology was present. This study contributes to understanding reproductive mechanisms that may facilitate coexistence between congeneric sympatric species.


Assuntos
Peixes-Gato , Simpatria , Animais , Feminino , Masculino , Peixes-Gato/anatomia & histologia , Peixes-Gato/fisiologia , Gônadas , Reprodução , Rios , Clima Tropical , Tamanho Corporal
14.
Proc Natl Acad Sci U S A ; 119(49): e2208772119, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36459637

RESUMO

Trabecular bone-the spongy bone inside marrow cavities-adapts to its mechanical environment during growth and development. Trabecular structure can therefore be interpreted as a functional record of locomotor behavior in extinct vertebrates. In this paper, we expand upon traditional links between form and function by situating ontogenetic trajectories of trabecular bone in four primate species into the broader developmental context of neural development, locomotor control, and ultimately life history. Our aim is to show that trabecular bone structure provides insights into ontogenetic variation in locomotor loading conditions as the product of interactions between increases in body mass and neuromuscular maturation. Our results demonstrate that age-related changes in trabecular bone volume fraction (BV/TV) are strongly and linearly associated with ontogenetic changes in locomotor kinetics. Age-related variation in locomotor kinetics and BV/TV is in turn strongly associated with brain and body size growth in all species. These results imply that age-related variation in BV/TV is a strong proxy for both locomotor kinetics and neuromuscular maturation. Finally, we show that distinct changes in the slope of age-related variation in bone volume fraction correspond to the age of the onset of locomotion and the age of locomotor maturity. Our findings compliment previous studies linking bone development to locomotor mechanics by providing a fundamental link to brain development and life history. This implies that trabecular structure of fossil subadults can be a proxy for the rate of neuromuscular maturation and major life history events like locomotor onset and the achievement of adult-like locomotor repertoires.


Assuntos
Osso Esponjoso , Primatas , Adulto , Animais , Humanos , Neurogênese , Fósseis , Tamanho Corporal
15.
J Therm Biol ; 110: 103385, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36462847

RESUMO

African mole-rats (Bathyergidae) are strictly subterranean rodents distributed in sub-Saharan Africa. Although the soil layer provides a temperature buffer, the temperature in their burrows is usually below their thermoneutral zone and thermogenesis is necessary to maintain a stable body temperature. In social bathyergids, an important mechanism for decreasing the thermoregulatory cost is social thermoregulation in the form of huddling. The effect of huddling may be of special importance during forming of a new family as only two adults are present and social species are known for higher heat losses from their bodies compared to solitary mole-rats. In our study, we measured the resting metabolic rate and energetic saving in three social bathyergid species which differ in body size. We compared animals that were housed individually and in pairs at two different ambient temperatures (Ta). At a temperature within their TNZ (Ta = 30 °C), no energetic savings were expected, whereas in Ta = 20 °C we expected energetic savings due to huddling. We found no energetic savings at 30 °C in any of the species, but almost 20% in the two small bodied Fukomys species F. micklemi and F. anselli at 20 °C. In the largest species, F. mechowii, no significant energetic savings were observed. Our results confirm the importance of huddling for the energetic balance of social mole-rats and show that huddling with one partner can bring substantial energetic savings, which can be allocated to other activities such as extension of established burrow systems or reproduction to increase the workforce and fulfill the purpose of dispersal.


Assuntos
Regulação da Temperatura Corporal , Ratos-Toupeira , Animais , Metabolismo Basal , Termogênese , Tamanho Corporal
16.
J Therm Biol ; 110: 103342, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36462853

RESUMO

Sea turtles generally lay several clutches of eggs in a single nesting season. While a negative correlation between water temperatures and the time required between constitutive nesting events (termed the internesting interval) has been previously reported in loggerhead Caretta caretta and green turtles Chelonia mydas, it is not understood whether this relationship remains constant across other sea turtle species. Here, we expanded upon these previous studies on loggerhead and green turtles by using larger sample sizes and including data from species with a wider range of body-sizes; specifically: hawksbill Eretmochelys imbricata, leatherback Dermochelys coriacea, and olive ridley turtles Lepidochelys olivacea. In total, we compiled temperature data from biologgers deployed over internesting intervals on 23 loggerhead, 22 green, 7 hawksbill, 26 leatherback and 11 olive ridley turtles from nesting sites in 8 different countries. The relationship between the duration of the internesting interval and water temperatures in green and loggerhead turtles were statistically similar yet it differed between all other turtle species. Specifically, hawksbill turtles had much longer internesting intervals than green or loggerhead turtles even after controlling for temperature. In addition, both olive ridley and leatherback turtles exhibited thermal independence of internesting intervals presumably due to the large body-size of leatherback turtles and the unique capacity of ridley turtles to delay oviposition. The observed interspecific differences in the relationship between the length of the internesting interval and water temperatures indicate the complex and variable responses that each sea turtle species may exhibit due to environmental fluctuations and climate change.


Assuntos
Tartarugas , Feminino , Animais , Temperatura , Água , Mudança Climática , Tamanho Corporal
17.
Rev. biol. trop ; 70(1)dic. 2022.
Artigo em Espanhol | LILACS-Express | LILACS, SaludCR | ID: biblio-1407247

RESUMO

Resumen Introducción: Los ríos tropicales se ven cada vez más afectados por la fragmentación y la regulación; y, en Colombia, se sabe que las represas ponen en peligro a los peces endémicos debido, entre otros, a la migración limitada y la disponibilidad reducida de redes alimenticias basadas en el detrito. Sin embargo, el conocimiento de la ictiofauna nativa afectada por represas en ríos altoandinos es aún incipiente. Objetivo: Evaluar los efectos de la represa del Neusa sobre la ictiofauna. Métodos: Comparamos dos secciones del río, una aguas arriba y otra aguas abajo de la represa con el Sistema Richter IHA, muestreamos tres transectos de 100 m de largo en cada sección, cada dos meses, entre 2017 y 2019. Los peces fueron devueltos al río después de efectuadas las mediciones corporales. Resultados: Recolectamos 729 individuos de cinco familias; los Trichomycterus bogotense eran más pequeños aguas abajo de la represa; Oncorhynchus mykiss fue más pequeño y menos abundante; y no hubo diferencias para Grundulus bogotensis y Eremophilus mutisii. Independientemente de los factores climáticos, O. mykiss y G. bogotensis fueron más abundantes aguas arriba, y E. mutisii y T. bogotense aguas abajo de la represa. Conclusión: Las cinco especies de peces diferían en cómo las poblaciones se diferencian aguas arriba y aguas abajo de la represa, lo que sugiere que algunas se benefician de la represa, mientras que otras se vuelven más pequeñas y menos abundantes.


Abstract Introduction: Tropical rivers are increasingly being affected by fragmentation and regulation; and, in Colombia, dams are known to endanger endemic fishes through, among others, limited migration and reduced availability of sediment-based feeding networks. However, knowledge of native ichthyofauna affected by dams in high Andean rivers is still incipient. Objective: To assess the effects of the Neusa dam on the ichthyofauna. Methods: We compared two rivers' sections, one above and one below the dam with the Richter IHA System, we sampled three 100 m long transects in each section, every two months, between 2017 and 2019. The fishes were returned to the river after body measurements. Results: We collected 729 individuals from five families; Trichomycterus bogotense were smaller under the dam; Oncorhynchus mykiss was smaller and less abundant; and there were no differences for Grundulus bogotensis and Eremophilus mutisii. Independently of climatic factors, O. mykiss and G. bogotensis were more abundant above the dam, and E. mutisii and T. bogotense under the dam. Conclusion: The five fish species differed in how the populations differed above and under the dam, suggesting that some are benefited by the dam, while others become smaller and less abundant.


Assuntos
Animais , Tamanho Corporal , Peixes , Colômbia
18.
BMC Ecol Evol ; 22(1): 142, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36513976

RESUMO

Carcinogenesis is one of the leading health concerns afflicting presumably every single animal species, including humans. Currently, cancer research expands considerably beyond medicine, becoming a focus in other branches of natural science. Accumulating evidence suggests that a proportional scale of tumor deaths involves domestic and wild animals and poses economical or conservation threats to many species. Therefore, understanding the genetic and physiological mechanisms of cancer initiation and its progression is essential for our future action and contingent prevention. From this perspective, I used an evolutionary-based approach to re-evaluate the baseline for debate around Peto's paradox. First, I review the background of information on which current understanding of Peto's paradox and evolutionary concept of carcinogenesis have been founded. The weak points and limitations of theoretical modeling or indirect reasoning in studies based on intraspecific, comparative studies of carcinogenesis are highlighted. This is then followed by detail discussion of an effect of the body mass in cancer research and the importance of cell size in consideration of body architecture; also, I note to the ambiguity around cell size invariance hypothesis and hard data for variability of cell size across species are provided. Finally, I point to the new research area that is driving concepts to identify exact molecular mechanisms promoting the process of tumorigenesis, which in turn may provide a proximate explanation of Peto's paradox. The novelty of the approach proposed therein lies in intraspecies testing of the effect of differentiation of cell size/number on the probability of carcinogenesis while controlling for the confounding effect of body mass/size.


Assuntos
Evolução Biológica , Neoplasias , Animais , Humanos , Tamanho Corporal , Neoplasias/genética , Carcinogênese , Tamanho Celular
19.
Biol Bull ; 243(2): 220-238, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36548974

RESUMO

AbstractThe temperature-size rule is one of the universal rules in ecology and states that ectotherms in warmer waters will grow faster as juveniles, mature at smaller sizes and younger ages, and reach smaller maximum body sizes. Many models have unsuccessfully attempted to reproduce temperature-size rule-consistent life histories by using two-term (anabolism and catabolism) Pütter-type growth models, such as the von Bertalanffy. Here, we present a physiologically structured individual growth model, which incorporates an energy budget and optimizes energy allocation to growth, reproduction, and reserves. Growth, maturation, and reproductive output emerge as a result of life-history optimization to specific physiological rates and mortality conditions. To assess which processes can lead to temperature-size rule-type life histories, we simulate 42 scenarios that differ in temperature and body size dependencies of intake, metabolism, and mortality rates. Results show that the temperature-size rule can emerge in two ways. The first way requires both intake and metabolism to increase with temperature, but the temperature-body size interaction of the two rates must lead to relatively faster intake increase in small individuals and relatively larger metabolism increase in large ones. The second way requires only higher temperature-driven natural mortality and faster intake rates in early life (no change in metabolic rates is needed). This selects for faster life histories with earlier maturation and increased reproductive output. Our model provides a novel mechanistic and evolutionary framework for identifying the conditions necessary for the temperature-size rule. It shows that the temperature-size rule is likely to reflect both physiological changes and life-history optimization and that use of von Bertalanffy-type models, which do not include reproduction processes, can hinder our ability to understand and predict ectotherm responses to climate change.


Assuntos
Temperatura Alta , Reprodução , Humanos , Animais , Temperatura , Evolução Biológica , Tamanho Corporal/fisiologia
20.
Biol Bull ; 243(2): 272-281, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36548970

RESUMO

AbstractThere is a scientific debate whether oxygen concentration may be a factor driving the pattern of size decrease at higher temperature. Central to this debate is the fact that oxygen availability relative to demand for living organisms decreases with increasing temperature. We examined whether rotifers Lecane inermis exposed to hypoxic conditions would evolve smaller sizes than rotifers exposed to normoxic conditions, using experimental evolution with the same fluctuating temperature but differentiated by three regimes of oxygen availability: normoxia, hypoxia throughout the whole thermal range, and hypoxia only at the highest temperature. Immediately after the six-month experiment (more than 90 generations), we tested the plasticity of size responses to temperature in three post-evolution groups, and we related these responses to fitness. The results show that normoxic rotifers had evolved significantly larger sizes than two hypoxic rotifer groups, which were similar in size. All three groups displayed similar plastic body size reductions in response to warming over the range of temperatures they were exposed to during the period of experimental evolution, but they showed different and complex responses at two temperatures below this range. Any type of plastic response to different temperatures resulted in a similar fitness pattern across post-evolution groups. We conclude that (i) these rotifers showed a genetic basis for the pattern of size decrease following evolution under both temperature-dependent and temperature-independent hypoxia; and (ii) plastic body size responds consistently to temperatures that are within the thermal range that the rotifers experienced during their evolutionary history, but responses become more noisy at novel temperatures, suggesting the importance of evolutionary responses to reliable environmental cues.


Assuntos
Temperatura Alta , Hipóxia , Animais , Temperatura , Tamanho Corporal , Oxigênio
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