Cytokine properties of prokineticins

Prokineticins are a novel family of secreted peptides with diverse regulatory roles, one of which is their capacity to modulate immunity in humans and in other species. Prokineticins are small peptides of 8 kDa that mediate their biological activities by signaling through two homologous G-protein-coupled receptors (prokineticin receptor 1 and prokineticin receptor 2). This family of peptides is characterized by a completely conserved N-terminal hexapeptide crucial for their bioactivities and a unique structural motif comprising five disulfide bonds. Prokineticins and their receptors are highly expressed in bone marrow, in peripheral circulating leukocytes, in inflamed tissues and in resident organ immune cells. Their structure, size, signaling and biological activities are reminiscent of the chemokine superfamily. In this review, emphasis is placed on the properties of prokineticins as cytokines and their role in the immune system.     

Sex differences in the influence of mothers on the sociosexual preferences of their offspring

The extent to which "nurture" as opposed to "nature" determines behavior and sociosexual preferences in mammalian species is controversial although most recent interest has focused on genetic determinants. We report here that if sheep and goats are cross-fostered at birth, but raised in mixed-species groups, their play and grooming behavior resembles that of their foster rather than genetic species. There are no sex differences in effects on these behaviors, and other species-specific behavior patterns such as aggression, browsing, climbing, and vocalizations are unaffected. In adulthood, cross-fostered males strongly prefer to socialize and mate with females of their foster mother's species, even if raised with a conspecific of their own species. Castration within 2 days of birth slightly reduces the level of this altered social preference but mating preference following short-term testosterone treatment is the same as for gonadally intact animals. Cross-fostered females also show significant preference for socializing with females and mating with males of their foster mother's species, although this effect is weaker than that in both gonadally intact and castrated males. When cross-fostered animals are placed in flocks containing members of only their genetic species for 3 years, male social and mating preferences for females of their mother's species remain virtually unaffected. Females change to display an exclusive mating preference for members of their genetic species in 1-2 years although they still retain some social interest in female members of their foster species. Thus, there are clear sex differences in the impact of the emotional bond between a mother and her offspring in these mammals. Effects on males are strongest and irreversibly maintained even after altering their social environment, whereas those on females are weaker and mating preferences are clearly adaptable in the face of altered social priorities. These sex differences are presumably caused by pre-, or early postnatal, organizational effects of sex hormones on the brain.     

Schizophrenia: an illness of distorted reality

Schizophrenia is a seriously disturbing disorder, both for the victim and for their families. Although treatments are available which can effectively control symptoms, their side effects are severe enough to cause many sufferers to discontinue taking them and their actions are not properly understood.     

Changing forms of transnationalism

This paper looks at second-generation immigrants and the effects of ‘inevitable’ assimilation on their transnational ties. The dominant concept of transnationalism is strongly influenced by the experience of transmigrants moving back and forth between the sending and receiving countries or by immigrants involved in transnational activities. Research on second-generation Hindustanis in the Netherlands shows that their transnational ties are strong due to the ethnification of their community. However, their transnational ties are changing. The second-generation Hindustanis have a source culture and are developing new ties, while loosening relations with their parents’ country. Thus, transnationalism is assuming new forms, calling for a typology of different forms of transnational relations.     

Lipase-mediated Resolution of Branched Chain Fatty Acids

Branched chain fatty acids (BCFAs) are fatty acids substituted with alkyl groups. Many of them are chiral and therefore occur in two enantiomeric forms. This review describes their occurrence in Nature, their biosynthesis, their properties as flavours, and their enzymatic kinetic resolution. Many lipases are able to separate the enantiomers of BCFAs, in hydrolysis, esterification or transesterification reactions. Very often, the stereoselectivity of these reactions is remarkably high, even when the chiral carbon atom is remote from the carboxylic acid group.     

Ecology of nutrition and differentiation of the trophic niches of bats (Chiroptera: Vespertilionidae) in floodplain ecosystems of the Samara Bend

A complex analysis of the food range of 15 bat species inhabiting floodplain ecosystems of the Samara Bend has been performed. It is shown that, in bats, an important component of the structuring of their communities is the division of food resources. The guild structure and position of species in the trophic space are described. Seven food guilds consisting of nonspecialized and specialized species are distinguished. It is noted that most species are characterized by a wide overlapping of their trophic niches, which may be a consequence of their weak competition in an environment that is rich in food resources.     

A test of Simpson's "rule of the survival of the relatively unspecialized" using fossil crinoids

Temporally long-ranging (=long-lived) taxa have been postulated to have unusual properties that aid their prolonged geologic survival. Past studies have examined dispersal capabilities, geographic ranges, and single-character morphological adaptations as factors that may contribute to geologic longevity. Here, I test whether long-lived fossil crinoid taxa are morphologically unusual using a whole suite of morphological characters. I define long-lived taxa in several explicit, comparative ways. I find that long-lived crinoid genera and families are often less distant from mean morphologies of their crinoid orders than their shorter-lived relatives; that is, they are relatively less specialized. I also compare the morphology of crinoid genera relative to basal members of their respective orders; mean morphological distances of long-lived genera from basal morphologies are seldom distinct from those of their shorter-lived relatives. I observe that long-lived crinoid genera are less distant from mean morphologies of their temporal cohorts compared with shorter-lived genera but not in a statistically significant manner. I conclude that long-lived crinoids are relatively unspecialized, in the sense that they are relatively closer to mean morphologies of their taxonomic groups.     

北京地区蕨类植物区系分析

对北京地区蕨类植物区系进行了初步分析,研究表明,北京共有蕨类植物77种,隶属于19科34属,以蹄盖蕨科、岩蕨科、鳞毛蕨科、卷柏科等为优势科,以岩蕨属、卷柏属、铁角蕨属等为优势属,科内及属内分化程度较低,种类组成贫乏;地理成分以温带成分占优势,有11属为温带分布属,占非世界分布属总数的61．11％,除世界种和中国特有种外,全为温带性质的种;生境特点以石生为主,大多数种类分布在北京西部和北部的山区;与河北的关系最为密切,其次为山西、内蒙、辽宁、山东,与秦岭也有一定的联系,与西藏的关系疏远。     

Lipase-mediated Resolution of Branched Chain Fatty Acids

Branched chain fatty acids (BCFAs) are fatty acids substituted with alkyl groups. Many of them are chiral and therefore occur in two enantiomeric forms. This review describes their occurrence in Nature, their biosynthesis, their properties as flavours, and their enzymatic kinetic resolution. Many lipases are able to separate the enantiomers of BCFAs, in hydrolysis, esterification or transesterification reactions. Very often, the stereoselectivity of these reactions is remarkably high, even when the chiral carbon atom is remote from the carboxylic acid group.     

Nutritional ecology of endoparasitic insects and their hosts: An overview

The impact of insect endoparasites (parasitoids) on the physiology and behaviour of their hosts is reviewed within the context of the nutritional ecology of the parasitoids and their hosts. Alterations in the consumption, utilization and allocation of food by parasitized hosts are common, as are internal changes in their metabolic physiology. Gregarious parasitoid species frequently increase feeding by their host larvae whereas solitary parasitoid species often reduce feeding and growth of their hosts. Many parasitoid-associated changes in host physiology and behaviour are interpreted to be of adaptive significance to parasitoids. Substantial circumstantial evidence suggests, and a few direct tests of such adaptive significance indicate, that parasitoids alter their hosts in ways beneficial to their own fitness. However, most of the changes in parasitized hosts are of unknown cause and undocumented significance to the parasitoids. Several relevant hypotheses are presented, and these require extensive evaluation (often requiring novel experimental approaches) before a thorough understanding of parasitoid nutritional ecology is established.     

Challenges of phylogenetic analyses of aDNA sequences

One of the crucial steps of authentication of aDNA sequences is phylogenetic consistency. Amplified sequences should fit into the phylogenetic framework of their supposed origin. An inherent property of aDNA sequences however, is their short sequence length. Additionally, genes for aDNA studies are often chosen by their preservation potential rather than by phylogenetically informative content. This poses potential challenges regarding their analyses, and might result in an inaccurate reflection of the supposed phylogenetic history of the sequence or organism under study. In this paper some fundamental problems of phylogenetic analysis and interpretation of aDNA datasets are discussed. Suggestions for character sampling and treatment of missing data are made. The publication is the result of a talk from the 1st PAMINSA Meeting in Rio de Janeiro, July 2005.     

Nuclear location of synthetic oligonucleotides microinjected somatic cells: its implication in an antisense strategy.

Synthetic oligonucleotides are widely used to modulate gene expression. However their development as genetic tools and as molecule of therapeutic interest is restricted by the poor knowledge of their mechanism of action and of their uptake by cells. We recently found that microinjected oligonucleotides accumulates in the nucleus of the cells. These observations are described and their implications are discussed.     

Neuronal structure of the frog vestibular ganglion]

Neuronal organization of the vestibular ganglion of the nerve VIII in the frog (Rana temporaria) has been studied by means of light and electron microscopy. It has been stated that bipolar ganglion-forming neurons are not quite identical in their structure. They differ in size, fine organization of their cytoplasm and in the manner they construct their glial sheaths. Among ganglial neurons, two types are distinguished: myelinizated and unmyelinizated neurons. A considerable part is composed by neurons coated with myelin sheath which can be constructed according to compact or loose type of myelin. Myelinizated neurons are mostly large cells, with their cytoplasm saturated with organells. Unmyelinizated neurons are coated with a simple sheath composed of one layer of lemmocytes processes. These neurons are much smaller in size, their cytoplasm is poor in organells and contains large amount of neurophilaments.     

The phenology of Syrphidae (Diptera): are they Batesian mimics of Hymenoptera?

The phenology of aculeate Hymenoptera and of syrphids which are believed to mimic them has been investigated at three semi-natural ancient woodland sites in north-west England. It is concluded that the abundance and phenology of most of the hoverflies is consistent with their being Batesian mimics of particular species of bee or wasp. The main exceptions are Eristalis spp., Helophilus spp., Syrphus spp. and Episyrphus balteatus which are often much more abundant than their supposed models. These four taxa may still benefit from mimicry, but further research is needed to confirm this. With the possible exceptions of Eristalis pertinax and E. tenax , there is no strong evidence from north-west England in support of Waldbauer's hypothesis that mimics are rare when fledgling birds are abundant but may be commoner in autumn and spring. The data also indicate that mimics which closely resemble their models (specific mimics) are usually rarer than their models, whereas mimics with a less precise resemblance (non-specific mimics) are often commoner than models.     

Mechanics of increased support of weight by the hindlimbs in primates

Quadrupedal primates support most of their weight on their hindlimbs during locomotion. Neither the position of their center of gravity nor the average position of their foot contacts is substantially different from that of other quadrupeds supporting most of their weight on their forelimbs. Arguments are presented to support the theory that high levels of hindlimb retractor activity will produce this shift of support to the hindlimbs. If this muscular activity is appropriately timed, it will generate only low horizontal accelerations, which can be offset by small changes in the average position of the limbs. Estimates of muscular force are derived from force plate and kinematic data, which indicate that primates in fact do exhibit the postulated pattern of muscular activity. It is suggested that this shift occurs to reduce the compressive forces on the forelimbs.     

非洲爪蟾GATA-1转录因子与爪蟾发育

GATA－1是GATA结合蛋白（GATA－binding protein）家族的成员之一,正向调节红细胞特异性基因的表达,是红系终末分化所必需的因子。与其他物种不同的是,非洲爪蟾GATA－1转录因子具有两业型,两者结构极为相似,但存在功能上的差异,非洲爪蟾GATA－1转录因子在爪蟾发育过程中起着重要的调节作用。     

Some relationships between the 'calling' posture and sexual receptivity in unmated females of the moth, Ephestia cautella

ABSTRACT. A positive relationship is shown between the frequency of successful completions of courtship and the extent of development of the 'calling' posture of E. cautella females. Further relationships are shown between the frequency of successful completions of courtship and the positions in which calling females hold their antennae. During late photophase, calling females which hold their antennae forward are less likely to mate than are similarly calling females which hold their antennae back over the wings, whereas in early scotophase this relationship is reversed, and calling females which hold their antennae forward are more likely to mate than are similarly calling females which hold their antennae back. These observations are discussed in relation to the diel rhythm of the species, disturbance, and female receptivity to male courtship.     

Interaction of phytotropins with the NPA receptor

The chemical and stereochemical properties of phytotropins are described in terms of a receptor model, based on their ability to bind to a receptor isolated from maize coleoptiles. Their root gravitropic properties are correlated with their ability to bind to the receptor. It is suggested that their ability to inhibit auxin transport, without more, may not be enough to explain their physiological effects.     

Formation of iron-sulfur clusters in bacteria: an emerging field in bioinorganic chemistry

Biological iron-sulfur clusters are chemically versatile inorganic structures that are attached to many proteins. These clusters are intimately involved in the functions of their partner proteins and they are required to sustain life on earth. Recent work has demonstrated that, in spite of their simple structures, the assembly and insertion of iron-sulfur clusters into their protein partners is a complex biological process. This complexity is probably related to the cellular toxicity of iron and sulfur in their free forms.