Larger Body Mass Research Articles

Is creeping abandonment of human cancer defences evolutionarily favoured?

Among observed animal species, humans exhibit a remarkably elevated lifetime cancer risk (over 38%), in stark contrast to less than 10% seen in other observed species (excluding those affected by environmental pollution). Peto's paradox suggests that these observations defy explanation through mathematical models treating cancer genesis as a stochastic process, with risks resulting from lifespan and body mass. For instance, whales, despite longer lifespans and roughly 30 times the size of humans, maintain consistent cancer risk throughout life, differing from the pronounced increase after female reproductive age observed in humans. It is well-documented in the literature that species-specific tumor suppression mechanisms allow for large lifespan and body mass. Examination of data from chimpanzees, a closely related species, suggests—without definitive evidence—a major difference between chimpanzee and human cancer risk. This leads to the conjecture that vulnerability of cancer defence mechanisms in humans might have emerged due to the unique evolutionary trajectory of the genus _Homo_. Given that this vulnerability emerges after reproductive years, a prevailing hypothesis attributes it to antagonistic pleiotropy. However, considering _Homo's_ historical existence in small tribes throughout much of evolution, we suggest that natural selection may have also operated at the tribal level. Consequently, our hypothesis, "Is creeping abandonment of human cancer defences evolutionarily favored?" arises from two alternative speculative scenarios. One proposition rests on the notion that diminishing tumor suppression activities could confer a calorie-saving advantage, particularly beneficial for tribes with limited food resources. The other proposition suggests that creeping abandonment of cancer defences might promote genetic diversity.

Is creeping abandon of human cancer defences evolutionarily favoured?

Among the animal species on which observations are available, humans have a uniquely high lifetime risk to suffer from cancer - over 38%, compared to less than 10% for all observed other species (except species suffering from environmental pollution). Peto's paradox shows that this cannot simply be explained by mathematical models which view cancer genesis as a stochastic process, with resulting risks polynomial in lifespan and body mass - whales have a longer lifespan and about 30 times the human body mass, however their cancer risk remains constant throughout their life rather than increasing sharply after female reproductive age as observed in humans. Rather, it is well documented in the literature that species-specific tumour suppression mechanisms allow for large lifespan and body mass. Data which was examined on chimpanzees, being closely related to humans, make it likely that there is a major difference between chimpanzee and human cancer risk, and hence the weakness of human cancer defence is likely to have resulted from the specific development of Homo sapiens. As this weakness appears past the reproductive years, a prominent hypothesis blames it to antagonistic pleiotropy. However, Homo sapiens having lived in small tribes during most of its development, natural selection is likely to also have acted at the level of tribes, which lets us derive our hypothesis, _is creeping abandon of human cancer defences evolutionarily favoured?_ from two alternative speculative scenarios. One of them is based on that lowering tumour suppression activities might save calories and hence benefit tribes with limited food production, the other one suggests that creeping abandon of cancer defences benefits genetical diversity.

Ontogenetic changes in bite force and gape in tufted capuchins.

Bite force and gape are two important performance metrics of the feeding system, and these metrics are inversely related for a given muscle size because of fundamental constraints in sarcomere length-tension relationships. How these competing performance metrics change in developing primates is largely unknown. Here we quantify in vivo bite forces and gapes across ontogeny and examine these data in relation to body mass and cranial measurements in captive tufted capuchins, Sapajus spp. Bite forces and gapes were also compared across geometric and mechanical properties of mechanically challenging foods to investigate relationships between bite forces, gapes, and food accessibility (defined here as the ability to breach shelled nuts). Bite forces at a range of gapes and feeding behavioral data were collected from a cross-sectional ontogenetic series of 20 captive and semi-wild tufted capuchins at the Núcleo de Procriação de Macacos-Prego Research Center in Araçatuba, Brazil. These data were paired with body mass, photogrammetric measures of jaw length and facial width, and food geometric and material properties. Tufted capuchins with larger body masses had absolutely higher in vivo bite forces and gapes, and animals with wider faces had absolutely higher bite forces. Bite forces and gapes were significantly smaller in juveniles compared to subadults and adults. These are the first primate data to empirically demonstrate the gapes at which maximum active bite force is generated and to demonstrate relationships to food accessibility. These data advance our understanding of how primates meet the changing performance demands of the feeding system during development.

What's inside a sauropod limb? First three‐dimensional investigation of the limb long bone microanatomy of a sauropod dinosaur, Nigersaurus taqueti (Neosauropoda, Rebbachisauridae), and implications for the weight‐bearing function

AbstractVarious terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight‐bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick cortex varying greatly in thickness along the shaft. However, the microanatomical variation in such taxa remains poorly known, especially between different limb elements. We highlight for the first time the three‐dimensional microstructure of the six limb long bone types of a sauropod dinosaur, Nigersaurus taqueti. Sampling several specimens of different sizes, we explored within‐bone, between‐bones, and size‐related variations. If a spongiosa fills the medullary area of all bones, the cortex is rather thin and varies only slightly in thickness along the shaft. Zeugopod bones appear more compact than stylopod ones, whereas no particular differences between serially homologous bones are found. Nigersaurus' pattern appears much less extreme than that in heavy terrestrial taxa such as rhinoceroses, but is partly similar to observations in elephants and in two‐dimensional sauropod data. Thus, microanatomy may have not been the predominant feature for weight‐bearing in sauropods. External features, such as columnarity (shared with elephants) and postcranial pneumaticity, may have played a major role for this function, thus relaxing pressures on microanatomy. Also, sauropods may have been lighter than expected for a given size. Our study calls for further three‐dimensional investigations, eventually yielding a framework characterizing more precisely how sauropod gigantism may have been possible.

Osteohistology reveals the smallest adult Jurassic sauropodomorph.

The earliest sauropodomorphs were small omnivores (less than 10 kg) that first appeared in the Carnian. By the Hettangian, early branching sauropodomorphs (EBSMs) were globally distributed, had variable postures, and some attained large body masses (greater than 10 tonnes). Small-bodied EBSMs like Massospondylus carinatus (less than 550 kg) persist at least until the Pliensbachian at nearly all dinosaur-bearing localities worldwide but are comparatively low in alpha diversity. One potential reason for this is competition with other similarly sized contemporary amniotes, including Triassic gomphodont cynodonts, Jurassic early branching ornithischians, herbivorous theropods and potentially early crocodylomorphs. Today's herbivorous mammals show a range of body size classes (less than 10 g to 7 tonnes), with multiple species of small herbivorous mammals (less than 100 kg) frequently co-occurring. Comparatively, our understanding of the phylogenetic distribution of body mass in Early Jurassic strata, and its explanatory power for the lower thresholds of body mass in EBSMs, needs more data. We osteohistologically sectioned a small humerus, BP/1/4732, from the upper Elliot Formation of South Africa. Its comparative morphology and osteohistology show that it represents a skeletally mature individual of a new sauropodomorph taxon with a body mass of approx. 75.35 kg. This makes it one of the smallest known sauropodomorph taxa, and the smallest ever reported from a Jurassic stratum.

Bridging archaeology and marine conservation in the Neotropics.

Anthropogenic impacts on tropical and subtropical coastal environments are increasing at an alarming rate, compromising ecosystem functions, structures and services. Understanding the scale of marine population decline and diversity loss requires a long-term perspective that incorporates information from a range of sources. The Southern Atlantic Ocean represents a major gap in our understanding of pre-industrial marine species composition. Here we begin to fill this gap by performing an extensive review of the published data on Middle and Late Holocene marine fish remains along the southern coast of Brazil. This region preserves archaeological sites that are unique archives of past socio-ecological systems and pre-European biological diversity. We assessed snapshots of species compositions and relative abundances spanning the last 9500 years, and modelled differences in species' functional traits between archaeological and modern fisheries. We found evidence for both generalist and specialist fishing practices in pre-European times, with large body size and body mass caught regularly over hundreds of years. Comparison with modern catches revealed a significant decline in these functional traits, possibly associated with overfishing and escalating human impacts in recent times.

Blood cells and hematological parameters of Chiala Mountain Salamander, Batrachuperus karlschmidti (Urodela, Hynobiidae).

Hematological parameters are essential indices for assessing the function of blood and reflecting not only the health status of animal but also their physiological adaptation to the environment. Herein, the composition of blood cells and the hematological parameters of wild Batrachuperus karlschmidti were examined for the first time, and the effects of sex, body size, body mass, and age on the hematological parameters were explored. The morphology and morphometric data of the blood cells, as well as the hematological parameters, of B. karlschmidti were slightly differ from those of its congener. However, hematological differences between sexes were only found in erythrocyte and leukocyte count, and mean cell volume (MCV), which possibly reflecting the need for better oxygen distribution and stronger immune protection for reproduction. Hematocrit (Hct) and mean cell hemoglobin (MCH) were strongly dependent on body mass. These also might have been attributed to higher oxygen requirements with larger body masses. This is a pilot project exploring the hematology of this species that may help establish hematological parameters in future for supporting species protection and monitoring studies, as well as help understanding the physiological adaptation of this species.

The spontaneous immortalization probability of mammalian cell culture strains, as their proliferative capacity, correlates with species body mass, not longevity

BackgroundThe Peto's paradox consists in the observation that individuals from long-lived and large animal species do not experience a higher cancer incidence, despite being exposed for longer time to the possibility of accumulating mutations and having more target cells exposed to the phenomenon. The existence of this paradox has been recently confirmed (Vincze et al., 2022). Concurrently, robust evidence has been published that longevity involves a convergent evolution of cellular mechanisms that prevent the accumulation of mutations (Cagan et al., 2022). It remains unclear which cellular mechanisms are critical to allow the evolution of a large body mass while keeping cancer at bay. MethodsAdding to existing data linking cellular replicative potential and species body mass (Lorenzini et al., 2005), we have grown a total of 84 skin fibroblast cell strains from 40 donors of 17 mammalian species and analyzed their Hayflick's limit, i.e., their senescent plateau, and eventual spontaneous immortalization escape. The correlation of immortalization and replicative capacity of the species with their longevity, body mass and metabolism has been assessed through phylogenetic multiple linear regression (MLR). ResultsThe immortalization probability is negatively related to species body mass. The new evaluation and additional data about replicative potential strengthen our previous observation, confirming that stable and extended proliferation is strongly correlated with the evolution of a large body mass rather than lifespan. ConclusionThe relation between immortalization and body mass suggests a need to evolve stringent mechanisms that control genetic stability during the evolution of a large body mass.

Influence of Body Mass on Running-Induced Changes in Mechanical Properties of Plantar Fascia.

Shiotani, H, Mizokuchi, T, Yamashita, R, Naito, M, and Kawakami, Y. Influence of body mass on running-induced changes in mechanical properties of plantar fascia. J Strength Cond Res 37(11): e588-e592, 2023-Body mass is a major risk factor for plantar fasciopathy; however, evidence explaining the process between risk factors and injury development is limited. Long-distance running induces transient and site-specific reduction in plantar fascia (PF) stiffness, reflecting mechanical fatigue and microscopic damage within the tissue. As greater mechanical loads can induce greater reduction in tissue stiffness, we hypothesized that the degree of running-induced change in PF stiffness is associated with body mass. Ten long-distance male runners (age: 21 - 23 years, body mass: 55.5 ± 4.2 kg; mean ± SD ) and 10 untrained men (age: 20 - 24 years, body mass: 58.4 ± 5.6 kg) ran for 10 km. Before and immediately after running, the shear wave velocity (SWV) of PF at the proximal site, which is an index of tissue stiffness, was measured using ultrasound shear wave elastography. Although the PF SWV significantly decreased after running in runners (-4.0%, p = 0.010) and untrained men (-21.9%, p < 0.001), runners exhibited smaller changes ( p < 0.001). The relative changes in SWV significantly correlated with body mass in both runners ( r = -0.691, p = 0.027) and untrained individuals ( r = -0.723, p = 0.018). These results indicate that a larger body mass is associated with a greater reduction in PF stiffness. Our findings provide in vivo evidence of the biomechanical basis for body mass as a risk factor for plantar fasciopathy. Furthermore, group differences suggest possible factors that reduce the fatigue responses, such as adaptation enhancing the resilience of PF and running mechanics.

Global patterns and predictors of avian population density

AbstractAimHow population density varies across animal species in the context of environmental gradients, and associated migratory strategies, remains poorly understood. The recent influx of avian trait data and population density estimates allows these patterns to be described and explored in unprecedented detail. This study aims to identify the main macroecological drivers of population density in birds.LocationGlobal.Time period1970–2021.Major taxa studiedBirds (Aves).MethodsWe collated a dataset of 5072 local population density estimates for 1853 species and modelled population density as a function of trait and environmental predictors in a Bayesian framework accounting for phylogenetic and spatial autocorrelation. We explored the influence of body mass, diet, primary lifestyle, mating system, nesting behaviour, territoriality, and migratory behaviour on population density, accounting for a range of environmental variables, including preferred habitat type, primary productivity, precipitation and temperature. Based on this empirical baseline, we then predicted the mean population density for 9089 species of birds and estimated global geographic patterns of bird population density.ResultsPopulation density was lower in species with larger body mass and higher trophic levels, and also declined in territorial species, migratory species, brood parasites and species inhabiting resource‐poor habitat types (e.g., deserts). Conversely, population density increased in cooperative breeders. Environmental drivers were most influential for migratory birds, with precipitation and temperature both associated with higher population density. Overall, bird population densities were higher at lower latitudes.Main conclusionsOur results support previous findings on the role of body mass, diet and environmental gradients, but also reveal novel species‐specific drivers of avian densities related to reproduction, migration and resource‐holding behaviour. Substantial fine‐scale variation remains unexplained. We provide a global dataset of population density predictions for use in macroecological analyses and conservation assessments.

Effect of age, mating history and temperature on male reproductive costs in the bean beetle Callosobruchus maculatus

Temperature and humidity determine seed viability, but their effect on seed pest reproduction, such as that of the bean beetle Callosobruchus maculatus, remains understudied. Adult male C. maculatus pass large ejaculates to mates while not feeding. Here, we studied ejaculate production and longevity in C. maculatus males at different temperatures and mating patterns. After development at 25, 27 and 29 °C, eclosing males were weighed and prevented from mating (m0) or allowed to mate once with virgin females three (m3) or five (m5) days after eclosion or to mate twice, three and five days after eclosion (m3+5). We weighed males before and after mating to estimate body mass loss due to ejaculate transfer and depletion of resources over time attributed to routine physiology/evaporation. Warmer conditions increased mortality and development rates and tended to decrease body mass. Males with a large body mass at eclosion survived longer than smaller males. The body mass of males was depleted at daily rates equal to 3–5% of body mass at eclosion. The rates of this loss increased in warmer conditions, suggesting that this process was the main determinant of the thermal pattern of mortality. During a single mating, males produced ejaculates that constituted 2–6% of their body mass at eclosion. Contrary to predictions, ejaculate production did not change with thermal conditions. Body mass losses through ejaculate transfer resulted in increased male mortality, and this effect was two times stronger than the effect of a comparable body mass loss through routine physiology/evaporation. Ejaculate mass decreased with age independent of mating history, suggesting that ejaculate production is restricted by routine physiology/evaporation losses. We conclude that the longevity of male C. maculatus is a function of body mass loss, but the two sources of body mass loss considered here, ejaculates and routine physiology, are not equally costly.

Shrub and precipitation interactions shape functional diversity of nematode communities on the Qinghai-Tibet Plateau.

Land use and climate change alter biodiversity patterns and ecosystem functioning worldwide. Land abandonment with consequent shrub encroachment and changes in precipitation gradients are known factors in global change. Yet, the consequences of interactions between these factors on the functional diversity of belowground communities remain insufficiently explored. Here, we investigated the dominant shrub effects on the functional diversity of soil nematode communities along a precipitation gradient on the Qinghai-Tibet Plateau. We collected three functional traits (life-history C-P value, body mass, and diet) and calculated the functional alpha and beta diversity of nematode communities using kernel density n-dimensional hypervolumes. We found that shrubs did not significantly alter the functional richness and dispersion, but significantly decreased the functional beta diversity of nematode communities in a pattern of functional homogenization. Shrubs benefited nematodes with longer life-history, larger body mass, and higher trophic levels. Moreover, the shrub effects on the functional diversity of nematodes depended strongly on precipitation. Increasing precipitation reversed the effects shrubs have on the functional richness and dispersion from negative to positive but amplified the negative effects shrubs have on functional beta diversity of nematodes. Benefactor shrubs had stronger effects on the functional alpha and beta diversity of nematodes than allelopathic shrubs along a precipitation gradient. A piecewise structural equation model showed that shrubs and its interactions with precipitation indirectly increased the functional richness and dispersion through plant biomass and soil total nitrogen, whereas it directly decreased the functional beta diversity. Our study reveals the expected changes in soil nematode functional diversity following shrub encroachment and precipitation, advancing our understanding of global climate change on nematode communities on the Qinghai-Tibet Plateau.

Catalog of EQ-5D-3L Health-Related Quality-of-Life Scores for 199 Chronic Conditions and Health Risks in Denmark.

A Danish national representative catalog of health-related quality-of-life scores for 199 chronic conditions is presented, which provides population estimates for chronic conditions subgroups that can be used for health economic evaluation.Two separate regression models of EQ-5D-3L utility scores with different sets of control variables are estimated to allow researchers to adjust for differences in the composition of the subgroups and provide a tool that can be used in other settings.Results indicate that health-related quality of life varies across disease groups but is lowest for renal disease, mental and behavioral disorders, benign neoplasms and diseases of the blood, digestive systems, and nervous systems.Health risks and lifestyle factors such as perceived stress, loneliness, and a large body mass index are highly correlated with health-related quality of life, and, in many cases, the correlation is higher than with individual diseases.

A personal acquisition time regimen of 68Ga-DOTATATE total-body PET/CT in patients with neuroendocrine tumor (NET): a feasibility study

BackgroundThe injection activity of tracer, acquisition time, patient-specific photon attenuation, and large body mass, can influence on image quality. Fixed acquisition time and body mass related injection activity in clinical practice results in a large difference in image quality. Thus, this study proposes a patient-specific acquisition time regimen of 68 Ga-DOTATATE total-body positron emission tomography-computed tomography (PET/CT) to counteract the influence of body mass (BM, kg) on image quality, and acquire an acceptable and constant image of patients with neuroendocrine tumors (NETs).MethodsThe development cohort consisting of 19 consecutive patients with full activity (88.7–204.9 MBq, 2.0 ± 0.1 MBq/kg) was to establish the acquisition time regimen. The liver SNR (signal-to-noise ratio, SNRL) was normalized (SNRnorm) by the product of injected activity (MBq) and acquisition time (min). Fitting of SNRnorm against body mass (BM, kg) in linear correlation was performed. Subjective assessment of image quality was performed using a 5-point Likert scale to determine the acceptable threshold of SNRL, and an optimized acquisition regimen based on BM was proposed, and validated its feasibility through the validation cohort of 57 consecutive NET patients with half activity (66.9 ± 11.3 MBq, 1.0 ± 0.1 MBq/kg) and a fixed acquisition time regimen.ResultsThe linear correlation (R2 = 0.63) between SNRnorm and BM (kg) was SNRnorm = -0.01*BM + 1.50. The threshold SNRL of acceptable image quality was 11.2. The patient-specific variable acquisition time regimen was determined as: t (min) = 125.4/(injective activity)*(-0.01*BM + 1.50)2. Based on that proposed regimen, the average acquisition time for acceptable image quality in the validation cohort was 2.99 ± 0.91 min, ranging from 2.18 to 6.35 min, which was reduced by 36.50% ~ 78.20% compared with the fixed acquisition time of 10 min. Subjective evaluation showed that acceptable image quality could be obtained at 3.00 min in the validation group, with an average subjective score of 3.44 ± 0.53 (kappa = 0.97, 95% CI: 0.96 ~ 0.98). Bland–Altman analysis revealed good agreement between the proposed regimen and the fixed acquisition time cohort.ConclusionA patient-specific acquisition time regimen was proposed in NET patients in development cohort and validated its feasibility in patients with NETs in validation cohort by 68 Ga-DOTATATE total-body PET/CT imaging. Based on the proposed regimen, the homogenous image quality with optimal acquisition time was available independent of body mass.

Тілобудова кваліфікованих воротарів і польових футболістів

The purpose of the study was to determine the indicators of physical development and body composition of goalkeepers and outfield football players. Materials and methods. 34 football players of the Ukrainian Premier League took part in the research, including: 11 goalkeepers and 23 outfield players. The following research methods were used: generalization of data from scientific and methodical literature, pedagogical observations, medical and biological methods (anthropometry, caliperometry); methods of mathematical statistics. Results and discussion. Anthropometric measurement was carried out according to 23 indicators and the composition of football players – according to 3 indicators. The most significant difference between goalkeepers and outfield players was determined by indicators of body weight, body length and body circumferences: wrist, forearm, shoulder at rest and tension, neck, hips. Thus, the body weight index of goalkeepers was 82.9 ± 5.8 kg, and outfield players – 69.1 ± 7.0 kg; the body length index of goalkeepers was 192.2 ± 5.1 cm, and that of outfield players was 179.2 ± 6.5 cm. That is, goalkeepers are taller compared to outfield players and mostly have a larger body mass. In addition, goalkeepers are stronger and stockier than outfield players in terms of parameters. Also, the indicators of skin-fat folds were significantly different, according to the playing role of footballers (p &lt;0.001). It was found that goalkeepers are larger in terms of the volumes in the chest, waist and skin-fat folds in the area of the lumbar region of the back. A slight difference (14%, p &lt;0.05) was found between goalkeepers and outfield players in the indicator of the skin-fat folds of the triceps muscle. A factor analysis of the obtained results of physical development was also carried out. The purpose of this analysis was to identify the generalized anthropometric characteristics and body composition of football players of various playing roles. Conclusion. For further consideration of the received information by the value of eigenvalues that had an indicator of at least 1, four informative factors were noted: factor 1 (7.99), factor 2 (2.24), factor 3 (1.58) and factor 4 (1.12). According to the relative contribution to the total variation, which should have been more than 10%, two informative factors were identified: factor 1 – 47.0%, factor 2 – 13.2%. It was possible to identify the following most important indicators for this group of factors: body weight, body length, circumferences: forearm, shoulder at rest, neck, waist, hips, lower legs; skin-fat folds: oblique abdominal muscle, biceps brachii, thigh, triceps brachii, lumbar back; composition of the body – "net mass". In the future, the results obtained in this way will allow coaches to make adjustments to the educational and training process to improve the physical and functional fitness of football players

Annual apparent survival across species is lower in juvenile than adult birds but has similar ecological correlates

Annual survival is a key demographic trait influencing population growth and viability. Variability among species in annual survival tends to reflect different life history trajectories. In adult birds, greater annual survival has been shown to be associated with larger body mass, smaller clutch size, lower latitude, island living, flocking and cooperative breeding. Less attention has focused on the ecological correlates of survival in birds during the first year of life. Using a phylogenetic framework, I explored the correlates of annual juvenile survival across species worldwide. When measured concurrently at the same study sites, annual apparent survival in a sample of 338 species was strongly and positively associated with body mass and was typically at least half of adult survival. Lower annual survival in juveniles probably arises through inexperience, but mortality might be overestimated as juveniles tend to disperse more extensively than adults. In a separate analysis involving 610 survival estimates from 342 species, I examined the ecological correlates of annual apparent survival in juveniles. With the exception of migration, most ecological correlates of annual apparent survival in adults, such as body mass, latitude and island living also prevailed in juveniles. The findings support the idea that the ecological factors associated with greater survival in adults are similar in juveniles.

The health of children of adolescent age delivered on time with light and large body mass

The need to preserve and promote health of children determine one of the basic directions of development of public social policy. It is the most important strategic purpose of modern children health care, since from it depend health of the nation, increasing of life expectancy and national economic potential.Purpose of the study is to assess health status of children of adolescent age born at term with diagnosis "fetus with low birth weight for gestational age" and with large body mass. The bibliographic, information-analytical and comparative analysis methodology were applied.

3D‐Printed Photoresponsive Liquid Crystal Elastomer Composites for Free‐Form Actuation

AbstractDirect ink writing of liquid crystal elastomers (LCEs) offers a new opportunity to program geometries for a wide variety of shape transformation modes toward applications such as soft robotics. So far, most 3D‐printed LCEs are thermally actuated. Herein, a 3D‐printable photoresponsive gold nanorod (AuNR)/LCE composite ink is developed, allowing for photothermal actuation of the 3D‐printed structures with AuNR as low as 0.1 wt.%. It is shown that the printed filament has a superior photothermal response with 27% actuation strain upon irradiation to near‐infrared (NIR) light (808 nm) at 1.4 W cm−2 (corresponding to 160 °C) under optimal printing conditions. The 3D‐printed composite structures can be globally or locally actuated into different shapes by controlling the area exposed to the NIR laser. Taking advantage of the customized structures enabled by 3D printing and the ability to control locally exposed light, a light‐responsive soft robot is demonstrated that can climb on a ratchet surface with a maximum speed of 0.284 mm s−1 (on a flat surface) and 0.216 mm s−1 (on a 30° titled surface), respectively, corresponding to 0.428 and 0.324 body length per min, respectively, with a large body mass (0.23 g) and thickness (1 mm).

Ontogenetic scaling of the baroreflex function in the green iguana (Iguana iguana).

Large body mass (Mb) in vertebrates is associated with longer pulse intervals between heartbeats (PI) and thicker arterial walls. Longer PI increases the time for diastolic pressure decay, possibly resulting in loss of cardiac energy as "oscillatory power," whereas thicker arterial walls may affect the transmission of impulses and sensing of pressure fluctuations thus impairing baroreflex function. We aimed to investigate the effect of growth on the relative cardiac energy loss and baroreflex function. We predicted that 1) the relative use of cardiac energy should be preserved with increased time constant for pressure decay (τ = vascular resistance × compliance) and 2) if arterial circumferential distensibility does not change, baroreflex function should be unaltered with Mb. To test these hypotheses, we used green iguanas (Iguana iguana) weighing from 0.03 to 1.34 kg (43-fold increment in Mb). PI (P = 0.037) and τ (P = 0.035) increased with Mb, whereas the oscillatory power fraction (P = 0.245) was unrelated to it. Thus, the concomitant alterations of τ and PI allowed the conservation of cardiac energy in larger lizards. Larger animals had thicker arterial walls (P = 0.0007) and greater relative collagen content (P = 0.022). Area compliance scaled positively to Mb (P = 0.045), though circumferential distensibility (P = 0.155) and elastic modulus (P = 0.762) were unaltered. In addition, baroreflex sensitivity, measured by both the pharmacological (P = 0.152) and sequence methods (P = 0.088), and the baroreflex effectiveness index (P = 0.306) were also unrelated to Mb. Therefore, changes in arterial morphology did not affect circumferential distensibility and presumably sensing of pressure fluctuation, and the cardiovagal baroreflex is preserved across different Mb.

Food Habits of Tiger (Panthera tigris) in Reserve Forest of Uttarakhand, India

Food availability and utilization are among the most critical factors influencing the distribution of free-ranging animals. Little is known about the feeding habit of the tiger ( Panther tigris ) outside the tiger reserves. We collected data on the diet ecology of the tiger in the reserve forest of Kumaon Himalayas, Uttarakhand, India. Scats analysis was used to determine the food habit of the tiger. A total of 55 scats were collected and analyzed. The overall diet diversity of tigers in DWA (Shannon-Wiener Index H') was 2.923. Scat contents were analyzed in terms of both the relative frequency of occurrence and the relative prey biomass consumed. A minimum of 13 different prey species were identified, of which chital constituted 30.91% of the diet followed by sambar (21.82%). The wild prey constituted 77.36% of the diet, whereas domestic prey constituted 23.64% of the diet. Prey selectivity analysis indicated that selective predation by tigers was directed towards prey species with large body mass. This highlights the importance of adjacent forests around protected areas that helps large carnivores to disperse spatially and temporally during resource crunch, competition, and dispersal.