Nonlinear Phenomena Conveying Body Size Information and Improving Attractiveness of the Courtship Calls in the Males of Odorrana tormota

Nonlinear phenomena are commonly shown in the vocalization of animals and exerts different adaptive functions.Although some studies have pointed out that nonlinear phenomena can enhance the individual identification of male Odorrana tormota,whether the nonlinear phenomena play a specific role in the sexual selection of O.tormota remain unclear.Here we presented evidence that there was a significant negative correlation(Pearson:n=30,r=0.65,P<0.001)between the nonlinear phenomena content and snout-vent length in the male O.tormota,and two-choice amplexus experiments showed that female O.tormota preferred male with smaller body size containing higher nonlinear phenomena content in its calls.Phonotaxis experiments also revealed that females preferred calls with higher nonlinear phenomena content.Additionally,compared to the calls with lower nonlinear phenomena content and higher fundamental frequency,there was shorter response time in phonotactic behaviour of female induced by the calls with higher nonlinear phenomena content and lower fundamental frequency.We argue that the nonlinear phenomena content in the calls of male O.tormota can convey its body size information and may provide important clues for female frogs in darkened surroundings to identify males’body size during mate choice,meanwhile,higher nonlinear phenomena content in males’calls may increase the attractiveness of males to females.The results of this study provide confirmation that,for O.tormota,nonlinear phenomena have specific function in mate choice.     

Triglycerides in the Human Kidney Cortex: Relationship with Body Size

Obesity is associated with increased risk for kidney disease and uric acid nephrolithiasis, but the pathophysiological mechanisms underpinning these associations are incompletely understood. Animal experiments have suggested that renal lipid accumulation and lipotoxicity may play a role, but whether lipid accumulation occurs in humans with increasing body mass index (BMI) is unknown. The association between obesity and abnormal triglyceride accumulation in non-adipose tissues (steatosis) has been described in the liver, heart, skeletal muscle and pancreas, but not in the human kidney. We used a quantitative biochemical assay to quantify triglyceride in normal kidney cortex samples from 54 patients undergoing nephrectomy for localized renal cell carcinoma. In subsets of the study population we evaluated the localization of lipid droplets by Oil Red O staining and measured 16 common ceramide species by mass spectrometry. There was a positive correlation between kidney cortex trigyceride content and BMI (Spearman R = 0.27, P = 0.04). Lipid droplets detectable by optical microscopy had a sporadic distribution but were generally more prevalent in individuals with higher BMI, with predominant localization in proximal tubule cells and to a lesser extent in glomeruli. Total ceramide content was inversely correlated with triglycerides. We postulate that obesity is associated with abnormal triglyceride accumulation (steatosis) in the human kidney. In turn, steatosis and lipotoxicity may contribute to the pathogenesis of obesity-associated kidney disease and nephrolithiasis.     

Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

Background

Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso.

Methodology/Principal Findings

We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers'' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes.

Conclusions/Significance

These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures.     

Body Size and Termite Evolution

Termites are a monophyletic lineage within the paraphyletic Blattaria, with xylophagous cockroaches in the genus Cryptocercus as sister group. Given this ancestry, termite divergence involved a substantial leap in body plans, as they are pale, fragile, and miniaturized relative to most cockroaches. Here I suggest that the evolutionary transition to an altricial morphotype in termites is grounded in the economics of utilizing a wood diet, and occurred via a series of sequential steps associated with modifications in social behavior. The chief benefit of an altricial morphotype is suggested to be nitrogen made available by decreasing individual body size and by dispensing with a heavy, melanized cuticle. The primary costs lie in increased vulnerability to environment hazards, including predators, pathogens, and desiccation. Termites tipped the evolutionary scale via cooperative behaviors that mitigate the cost or amplify the benefit of a small, fragile morphotype, and were present in rudimentary form in their cockroach relatives. These include building behavior, cooperative feeding, allogrooming, and most notably, trophallaxis. It was the directed circulation of nitrogenous reserves via trophallactic feeding among units of the superorganism rather than their progressive storage in a large, heavily armored body that was the foundation of termite evolutionary success.     

Visual Diet versus Associative Learning as Mechanisms of Change in Body Size Preferences

Systematic differences between populations in their preferences for body size may arise as a result of an adaptive ‘prepared learning’ mechanism, whereby cues to health or status in the local population are internalized and affect body preferences. Alternatively, differences between populations may reflect their ‘visual diet’ as a cognitive byproduct of mere exposure. Here we test the relative importance of these two explanations for variation in body preferences. Two studies were conducted where female observers were exposed to pictures of high or low BMI women which were either aspirational (healthy, attractive models in high status clothes) or non-aspirational (eating disordered patients in grey leotards), or to combinations thereof, in order to manipulate their body-weight preferences which were tested at baseline and at post–test. Overall, results showed good support for visual diet effects (seeing a string of small or large bodies resulted in a change from pre- to post-test whether the bodies were aspirational or not) and also some support for the associative learning explanation (exposure to aspirational images of overweight women induced a towards preferring larger bodies, even when accompanied by equal exposure to lower weight bodies in the non-aspirational category). Thus, both influences may act in parallel.     

Racial Differences in Selection of Ideal Body Size by Adolescent Females

Cultural differences may partially account for the fact that more black women than white women are overweight in the United States. This study measured perceptions of ideal body size among 93 black and 80 white females, 14–17 years old, who were randomly selected from three public high schools in a southeastern state. The subjects' height and weight were measured along with their estimates of their mother's body size, weight control attitudes, and demographic variables . Blacks preferred a significantly larger body sue than whites when asked to select ideal body size (p=0.045). Subjects who estimated their mother's size to be larger, also selected a larger ideal body size (p=.047). Those who perceived themselves as too fat were more likely to skip meals to help control their weight, compared with those who perceived themselves as normal or too thin (p=.003). Approximately 30% of the sample was overweight or obese. There were not significant racial differences in weight or BMI . These results suggest that overweight is more acceptable among black females than among white females and may help explain why more black females are obese .     

Vocal and Facial Attractiveness Judgments of Children, Adolescents and Adults: the Ontogeny of Mate Choice

Physical traits are thought to be used as indicators of mate quality, allowing individuals to select mates most likely to help them bear the fittest offspring. As the capacity for human sexual behaviour emerges at puberty, we investigated whether adult‐like judgments of the relative attractiveness of opposite‐sex individuals also arise at puberty. Following previous research, we focussed on facial and vocal attractiveness, which are known to be used in human mate choice and to carry concordant information regarding mate quality. Here we show that males with more attractive faces have more attractive voices as judged by female adults and adolescents, but not by female children. This suggests that cues of facial and vocal attractiveness provide similar information, but that awareness of these cues does not develop fully until reproductive capability, when mate choice judgments become relevant. Adolescents’ judgments also mirrored those of adults in that, like adults, they preferred lower‐pitched male voices, and as a group made concordant judgments about facial attractiveness. However, they did not make similarly concordant judgments about vocal attractiveness, suggesting that a further period of maturation and learning is required to fully develop optimal judgments for mate choice.     

Fisher's Axiom and the Body Size of Animals

What is here called Fisher's axiom states that all large mutations are deleterious, and the consequence of this is the generally accepted Darwinian notion that all evolutionary progress must have occurred through the accumulation of small mutational steps. We have in the present paper tested the postulate that one parameter, namely, the body size (weight or volume) does not vary in this way, but rather in steps which are powers of two, up to or down, as the case may be. The outcome of our analysis is that this hypothesis is corroborated with fair significance for certain, randomly selected, groups of living and extinct animals. The consequences of this observation are briefly discussed.     

Body Size and Reproductive Tactics in Varanid lizards

Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard （Varanus salvator） were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads （head width） than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 （10-23） pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares （PGLS） analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch （or/and egg） mass and the SVL although there were significant linear relationship between clutch （or/and egg） mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.     

Diversity and Evolution of Body Size in Fishes

The diversity of body sizes observed among species of a clade is a combined result of microevolutionary processes (i.e. natural selection and genetic drift) that cause size changes within phylogenetic lineages, and macroevolutionary processes (i.e. speciation and extinction) that affect net rates of diversification among lineages. Here we assess trends of size diversity and evolution in fishes (non-tetrapod craniates), employing paleontological, macroecological, and phylogenetic information. Fishes are well suited to studies of size diversity and evolution, as they are highly diverse, representing more than 50% of all living vertebrate species, and many fish taxa are well represented in the fossil record from throughout the Phanerozoic. Further, the frequency distributions of sizes among fish lineages resemble those of most other animal taxa, in being right-skewed, even on a log scale. Using an approach that measures rates of size evolution (in darwins) within a formal phylogenetic framework, we interpret the shape of size distributions as a balance between the competing forces of diversification, pushing taxa away from ancestral values, and of conservation, drawing taxa closer to a central tendency. Within this context we show how non-directional mechanisms of evolution (i.e. passive diffusion processes) can produce an hitherto unperceived bias to larger size, when size is measured on the conventional log scale. These results demonstrate how the interpretation of macroecological datasets can be enriched from an historical perspective, and document the ways in which macroevolutionary and microevolutionary processes may be decoupled in the production of size diversity.     

瘦蛋白介导的人食欲与体重调节机制

瘦蛋白(leptin)介导了一个由5个基因的表达与调控组成的食欲调节系统,从而实现了人体重的反馈调节。深入分析类体重调节的,矿子机制对于阐明肥胖发生的生理学机制,以及对于抗肥胖药物的设计和筛选具育重要意义。     

Egg Load and Body Size of Lab-cultured Cotesia marginiventris

The egg load of lab-cultured Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae), a solitary koinobiont endoparasitoid of noctuid caterpillars, was determined in this study. Information on egg load may provide clues to more efficient in vivo rearing of C. marginiventris. I tested the hypothesis that egg load, defined as the number of mature oöcytes (i.e., fully chorionated eggs) found in adult females, was related to body size. Cotesia marginiventris females possessed two ovaries and two ovarioles per ovary; mature eggs were found in ovaries and oviducts. Newly-emerged females held an average of 149 mature eggs. Immature eggs were slightly visible in the distal portions of the ovarioles; they were not counted. Egg load was marginally related to body size (i.e., hind tibia length). The results of this study suggest that (1) body size can sometimes predict egg load or potential fecundity of lab-cultured C. marginiventris and (2) an efficient rearing system that exploits the potential fecundity of C. marginiventris might involve using young females and allowing them to oviposit in new hosts, each day, for up to a week.     

Body Size Perceptions and Eating Attitudes in Elderly Men

The majority of studies on eating attitudes, dieting and body size perceptions have focused on young adults and women. This study examined these attitudes in 334 black and white men, ages 55 to 98 years, who were members of the Charleston Heart Study cohort. Associations of the eating attitude variable with race, education and weight status were examined. Eighty-two percent of the overweight white men studied had dieted to lose weight, whereas only 49% of slimmer white men had dieted. In contrast, overweight black men did not diet more than slimmer black men. Overall black men dieted less than white men (37% reported dieting). Black men who were high school graduates were 1.3 times more likely to have dieted than were less educated black men. Overweight white men were over twice as likely as slimmer white men to feel guilty after overeating. This difference was not found in overweight versus slimmer black men. Education was not associated with measured body mass index (BMI) or perceived or ideal body size. However, there were some racial differences in these variables. White men preferred to be slightly thinner than black men (ideal BMI 25.6 vs. 26.1 kg/m²), and the difference between actual and desired BMI was 0.6 kg/m² greater in white than in black men. These results indicate that effects of race and weight status on eating restraint and body size perceptions seen in younger subjects and in women are also present, at least to some degree, in elderly men.     

Correlation between Genetic Variability and Body Size in Vertebrates

An analysis of allozymic variation carried out in the main groups of vertebrate animals revealed a tendency towards the increased level of genetic polymorphism in the species of small animals compared to the large ones. This tendency was clearly followed in caudate amphibians, fishes, and mammals. The data are discussed in terms of the integration of monogenic and polygenic systems in the populations. It is hypothesized that this relationship between heterozygosity and body size confirms more general regularity consisting in highly statistically significant correlation between polygenic heterozygosity, maturation rate and life span. It is suggested that high rate of development in small animals resulting in early sexual maturation, can serve as a mechanism determining correlation between heterozygosity and body size at the species level. As a result, compared to large animals, small animals display higher rates of generation change, resulting in accelerated growth of population size and faster accumulation of genetic variability.     

Larger Mammalian Body Size Leads to Lower Retroviral Activity

Retroviruses have been infecting mammals for at least 100 million years, leaving descendants in host genomes known as endogenous retroviruses (ERVs). The abundance of ERVs is partly determined by their mode of replication, but it has also been suggested that host life history traits could enhance or suppress their activity. We show that larger bodied species have lower levels of ERV activity by reconstructing the rate of ERV integration across 38 mammalian species. Body size explains 37% of the variance in ERV integration rate over the last 10 million years, controlling for the effect of confounding due to other life history traits. Furthermore, 68% of the variance in the mean age of ERVs per genome can also be explained by body size. These results indicate that body size limits the number of recently replicating ERVs due to their detrimental effects on their host. To comprehend the possible mechanistic links between body size and ERV integration we built a mathematical model, which shows that ERV abundance is favored by lower body size and higher horizontal transmission rates. We argue that because retroviral integration is tumorigenic, the negative correlation between body size and ERV numbers results from the necessity to reduce the risk of cancer, under the assumption that this risk scales positively with body size. Our model also fits the empirical observation that the lifetime risk of cancer is relatively invariant among mammals regardless of their body size, known as Peto''s paradox, and indicates that larger bodied mammals may have evolved mechanisms to limit ERV activity.