Role-Reversed Nepotism Among Cubs and Sires in the Spotted Hyena (Crocuta crocuta)

Nepotism is widespread among parents and offspring, and is typically associated with fundamental asymmetries; parents can usually do more to help their offspring than vice versa, and the cost of a given nepotistic behavior is usually less for parents than for offspring. This may not be so among spotted hyenas (Crocuta crocuta); sires never achieve social rank equal to that of their cubs, to whom they provide no obvious paternal care. Nepotism by sires towards their cubs is thus socially constrained. However, the higher social status of cubs might offset cubs’ developmental disadvantages and permit nepotistic treatment of sires by offspring. We therefore sought to determine whether the interactions among spotted hyena cubs and adult males were influenced by kinship, using long‐term observations from one clan of spotted hyenas. Sires exhibited no overt nepotism towards their cubs in most behaviors, but they did associate more closely with their daughters than with unrelated control females. Sires also associated more closely with their daughters than with their sons, with whom they associated no more closely than they did with unrelated control males. Cubs favored their sires by directing less intense aggression towards them than towards unrelated control males. Cubs of both sexes also associated more closely with their sires than with control males after the cubs were independent of the clan's communal den. Although sires evidently recognize their offspring, paternal nepotism by sires towards their cubs is weaker than filial nepotism by cubs towards their sires. The small size and immaturity of cubs thus appear to be weaker constraints on nepotism than is the low social status of their sires.     

Préserver la fertilité chez les adolescents traités pour un cancer. Le point de vue du psycho-oncologue

The question of fertility is a major concern for young adults successfully treated for cancer, which is why semen preservation should be proposed to all adolescent boys prior to treatment of a cancer. This proposal is part of the oncologist’s approach to prevent sequelae. To ensure that semen cryopreservation is conducted under good conditions and is accepted by the adolescent, it is important to have a good understanding of the psychopathology and behaviour of adolescents with cancer: their preoccupation with their body, their appearance, their sexuality, their relationships to their peers and to their parents, their value and narcissism, their identity. This helps the clinician to understand and overcome the various reasons for their difficulty (and to lessen the painful feeling of failure) or their reticence to perform semen cryopreservation: paralysed by the diagnosis of cancer, sexual inhibition, lack of understanding and ignorance, pessimism concerning outcome, incapacity to project into the future, poor relationship with parents, discredit of parenthood, fear of transmitting the cancer, etc. A good understanding of these elements can avoid an excessively rapid acceptance of a superficial opposition to this procedure that the patient could subsequently regret. Closer collaboration should be developed between oncology-haematology departments and CECOS units to provide suitable information material to adolescents, to improve the understanding of the specific psychology of adolescents, and to understand the parents’ positions.     

Evolution in the pentastomids

The Pentastomida, or tongue worms, form an aberrant group of annulated endoparasites little known to most parasitologists and veterinarians. Although there is no doubt of their affiliation to arthropods, textbooks often rank the Pentastomida as a separate phylum. Riley's many publications on the group have 'promoted it from the realm of the completely unknown to the semi-obscure', but still much research is needed on their basic biology, as little is known about their biochemistry, ecology or their evolutionary relationships. This review by Rolf Haugerud is intended to inspire curiosity about the Pentastomida by discussing their evolution in relation to their phylogeny, host relationships, geographic distribution, transmission and impact.     

New principles and criteria in assessing pathogenic and opportunistic microorganisms

Using the ecological and natural-science approaches, the authors have come to the conclusion that microorganisms, pathogenic for humans (animals), are their parasites for whom the disease of their biological host is the necessary condition of their existence as a biological species. And accordingly, microorganisms, opportunistic in humans (animals) are their parasites and commensals, as well as saprophytes, for whom the disease of their host is not the necessary condition of their existence in nature. The biological host is a symbion necessary for the existence of pathogenic and most opportunistic microorganisms, but for a pathogenic microorganism the disease of the host is the result of symbiotic relationships, while for an opportunistic microorganism the disease of the host is the consequence of disturbances in symbiotic relationships. Such view of pathogenicity is important for creating a scientifically grounded theory of the liquidation of human infectious diseases.     

植物源抗菌肽的研究进展

植物抗菌肽是植物自身合成的能够防御环境中微生物侵害的一类小分子多肽.它们大都是阳离子多肽,有较好的热稳定性.根据作用位点和抗菌机理的不同,植物抗菌肽可分为三大类:第一类通过干扰微生物细胞壁的合成来抑制微生物生长;第二类作用于质膜使其产生穿膜孔洞,从而导致微生物因细胞物质外泄受损;第三类则通过抑制某些细胞器的作用而起到抑菌的效果.本文从抗菌肽的作用机理及其分类等方面对植物源抗菌肽的研究进展进行了综述.     

The neuronal zootype

We present an hypothesis, derived from the zootype concept of Slack, Holland and Graham. The main point of this hypothesis is to postulate that the primordial function of the zootype genes is to design an appropriate neuronal network in bilaterian animals, by controlling the genes involved in the specificity of the axon pathways. This would be the primary function of the zootype genes in development and their primitive function in evolution. The hypothesis is discussed in view of the current knowledge on the Hox genes, their evolution, their genomic organisation, their expression and their targets.     

Fluorescent lipid probes: properties and application

This review is devoted to fluorescent lipid probes: the characteristics of their fluorophores; the main methods of their synthesis; and the potentialities, scope, and limitations of their use in studies of biological systems (cells, membranes and their models, enzymes of lipid metabolism, etc.). Particular attention is paid to the lipid specificity of the probes, i.e., the correspondence of their physicochemical characteristics and behavior in biological systems to those of natural lipids.     

Electron microscopic study of the methylcellulose-mediated detachment of cellulolytic rumen bacteria from cellulose fibers

The presence of methylcellulose prevents the attachment of cellulolytic rumen bacteria to cellulose fibers. The addition of methylcellulose to pure cultures of these organisms in which the cells are already adherent to cellulose causes their detachment from this insoluble substrate and the inhibition of their growth. Methylcellulose is not used as a carbon source by these organisms and has no effect on their growth when glucose and cellobiose are the carbon sources. Attached cells of Bacteroides succinogenes orient themselves in the plane of the individual cellulose fibers and their methylcellulose-induced detachment, which is complete (almost 100%), leaves grooves where the cellulose has been digested. Attached cells of Ruminococcus albus colonize the cellulose in a looser and less regular pattern and their almost complete methylcellulose-induced detachment leaves less regular pits in the cellulose surface. On the other hand, attached cells of Ruminococcus flavefaciens colonize the cellulose surface in a random orientation by means of a discernible exopolysaccharide network, and their less complete methylcellulose-induced detachment leaves no residual impressions on the cellulose surface. These data support the suggestion that bacterial attachment is necessary for the digestion of highly ordered crystalline cellulose, and that cellulolytic species differ in the nature of their attachment to this insoluble substrate and in the nature of their enzymatic attack. Methylcellulose is an effective agent for detaching major rumen cellulolytic bacteria from their cellulosic substrate.     

Experimental and observational evidence reveals that predators in natural environments do not regulate their prey: They are passengers,not drivers

Among both ecologists and the wider community there is a tacit assumption that predators regulate populations of their prey. But there is evidence from a wide taxonomic and geographic range of studies that predators that are adapted to co-evolved prey generally do not regulate their prey. This is because predators either cannot reproduce as fast as their prey and/or are inefficient hunters unable to catch enough prey to sustain maximum reproduction. The greater capacity of herbivores to breed successfully is, however, normally restricted by a lack of enough food of sufficient quality to support reproduction. But whenever this shortage is alleviated by a large pulse of food, herbivores increase their numbers to outbreak levels. Their predators are unable to contain this increase, but their numbers, too, surge in response to this increase in food. Eventually both their populations will crash once the food supply runs out, first for the herbivores and then for the predators. Then an “over-run” of predators will further depress the already declining prey population, appearing to be controlling its abundance. This latter phenomenon has led many ecologists to conclude that predators are regulating the numbers of their prey. However, it is the same process that is revealed during outbreaks that limits populations of both predator and prey in “normal” times, although this is usually not readily apparent. Nevertheless, as all the diverse cases discussed here attest, the abundance of predators and their co-evolved prey are both limited by their food: the predators are passengers, not drivers.     

The Color of My Skin: A Measure to Assess Children's Perceptions of Their Skin Color

The Color of My Skin is an instrument developed to assess children's internalized idea (abstraction) of the color of their skin; their satisfaction with that color; the desire, if any, to change the color of their skin; and their affect regarding their skin color. The assessment is part of a questionnaire utilized in a 3-year longitudinal study that examines psychosocial development, physical health, and behavioral adjustment of Puerto Rican children (N = 257) reared in the Greater Boston area. The results demonstrate that children's internalized representation of their skin color is a construct that can be reliably and validly measured. The children's ratings of their skin color were not associated with their sex, school grade, ethnic identity, the child's or the parent's nativity, or the racial or ethnic compositions of 3 social contexts: their neighborhood, their classmates, and their closest friends. Puerto Rican children did not show a preference for light-colored skin. Moreover, there were no significant differences in self-esteem based on the child's self-reported skin color. The lack of association between self-esteem and skin color was interpreted in light of a developmental tendency prevalent in early to middle childhood to place a positive value on different aspects of one's self. Whereas almost all children (96%) reported being happy or very happy with their color, 16% of the children would like to change their skin color if they could (51% to a lighter and 46% to a darker color).     

The role and therapeutic potential of connexins,pannexins and their channels in Parkinson's disease

Lack of effective medication for slowing down progression of Parkinson's disease (PD) as a highly prevalent neurodegenerative disorder requires novel avenues of scientific investigation to elucidate the underlying molecular and cellular mechanisms. Studying connexins, pannexins and their channels has uncovered their potential role in mediating communication and signaling pathways that drive neurodegenerative diseases, including PD. Indeed, given their critical role in tissue homeostasis, it is not surprising that connexins, pannexins and their channels are frequently involved in pathological processes. For this reason, pharmacological tools to further clarify their functions and to validate connexins, pannexins and their channels as drug targets for the development of novel therapies for PD treatment are urgently needed. In this paper, a state-of-the-art overview is provided of current neuropathological and molecular understanding of PD. Focus is put on the roles of connexins, pannexins and their channels, in particular in the development of potential innovative disease-modifying therapies for PD treatment.     

Campylobacter bacteriophages and bacteriophage therapy

Members of the genus Campylobacter are frequently responsible for human enteric disease with occasionally very serious outcomes. Much of this disease burden is thought to arise from consumption of contaminated poultry products. More than 80% of poultry in the UK harbour Campylobacter as a part of their intestinal flora. To address this unacceptably high prevalence, various interventions have been suggested and evaluated. Among these is the novel approach of using Campylobacter-specific bacteriophages, which are natural predators of the pathogen. To optimize their use as therapeutic agents, it is important to have a comprehensive understanding of the bacteriophages that infect Campylobacter, and how they can affect their host bacteria. This review will focus on many aspects of Campylobacter-specific bacteriophages including: their first isolation in the 1960s, their use in bacteriophage typing schemes, their isolation from the different biological sources and genomic characterization. As well as their use as therapeutic agents to reduce Campylobacter in poultry their future potential, including their use in bio-sanitization of food, will be explored. The evolutionary consequences of naturally occurring bacteriophage infection that have come to light through investigations of bacteriophages in the poultry ecosystem will also be discussed.     

Do second-generation Asian Americans face a systematic disadvantage in occupational attainment? Comment on Tran,Lee and Huang

ABSTRACT

We critically review and discuss several methodological problems with their analysis. Their definition of the occupational hierarchy is unclear, and their inadequate statistical models exacerbate the vagueness of their results. They ignore gender interactions, and the age range of their target population seems too narrow for their research concerns. Their interpretation of their own statistical findings on occupational attainment is fundamentally flawed although they refuse to acknowledge it. Their reported results cannot be replicated based on the information that they are willing to reveal about their analysis which suggests additional, undisclosed errors. In our reanalysis of their data using more appropriate methods, we find that rather than being systematically disadvantaged, the occupational attainment of most second-generation Asian Americans has either achieved parity with whites or has exceeded them after controlling for age, educational level, and survey year.     

Per cent emergent weight: A roadmap to adult rhinoceros beetle,Oryctes rhinoceros,behaviour

Adult rhinoceros beetles, Oryctes rhinoceros L., leave their pupal chambers, take their first flight, and die at well-defined ratios of their wet weight and their adult emergent weight. In addition, the beetles feed in a cyclical manner that is variable with time; however, each feeding event is well defined by a constant ratio of their weight just prior to feeding and their adult emergent weight. The ability to accurately estimate the emergent weight of field collected beetles, and therefore calculate the percentage emergent weight at the time of capture, makes these correlations useful in ecological studies and may be extended to other insects.     

Mimicry on the edge: why do mimics vary in resemblance to their model in different parts of their geographical range?

Batesian mimics-benign species that predators avoid because they resemble a dangerous species-often vary geographically in resemblance to their model. Such geographical variation in mimic-model resemblance may reflect geographical variation in model abundance. Natural selection should favour even poor mimics where their model is common, but only good mimics where their model is rare. We tested these predictions in a snake-mimicry complex where the geographical range of the mimic extends beyond that of its model. Mimics on the edge of their model's range (where the model was rare) resembled the model more closely than did mimics in the centre of their model's range (where the model was common). When free-ranging natural predators on the edge of the model's range were given a choice of attacking replicas of good or poor mimics, they avoided only good mimics. By contrast, those in the centre of the model's range attacked good and poor mimics equally frequently. Generally, although poor mimics may persist in areas where their model is common, only the best mimics should occur in areas where their model is rare. Thus, counter-intuitively, the best mimics may occur on the edge of their model's range.     

Ecophysiology of the <Emphasis Type="Italic">Actinobacteria</Emphasis> in activated sludge systems

This review considers what is known about the Actinobacteria in activated sludge systems, their abundance and their functional roles there. Participation in processes leading to the microbiological removal of phosphate and in the operational problems of bulking and foaming are discussed in terms of their ecophysiological traits. We consider critically whether elucidation of their nutritional requirements and other physiological properties allow us to understand better what might affect their survival capabilities in these highly competitive systems. Furthermore, how this information might allow us to improve how these processes work is discussed.     

The polyamines spermine and spermidine protect proteins from structural and functional damage by AGE precursors: a new role for old molecules?

Due to the importance of glycation in the genesis of diabetic complications, an intense search for synthetic new antiglycation agents is ongoing. However, a somewhat neglected avenue is the search for endogenous compounds that may inhibit the process and be a source of protodrugs. Based on their ubiquity, their polycationic nature, their essential role in growth, their relatively high concentrations in tissues, and their high concentrations in sperm, we hypothesized that polyamines inhibit glycation and that might be one of their so far elusive functions. In this study we demonstrate a potent antiglycation effect of physiological concentrations of the polyamines spermine and spermidine. We employed two approaches: in the first, we monitored structural changes on histones and ubiquitin in which polyamines inhibit glycation-induced dimer and polymer formation. In the second we monitored functional impairment of catalytic activity of antithrombin III and plasminogen. Protection is afforded against glycation by hexoses, trioses and dicarbonyls AGE precursors and is comparable to those of aminoguanidine and carnosine.     

Stresses on the limbs of quadrupedal primates

Data is presented from eight primates on the ground reaction forces on the limbs during locomotion. These subjects supported from 30 to 45% of their body weight on their forelimbs. Other quadrupedal mammals support 55-60% of their body weight on their forelimbs. The increase of peak vertical force with speed varies greatly between the subjects. The variation in weight supported by the forelimbs and the peak forces on the forelimbs is proposed to correlate with variation in locomotor adaptations. It is suggested that the occurrence of bipedalism in primates represents the extreme expression of the tendency in primates to reduce the compressive forces on their forelimbs.