How soil granulometry,temperature, and water predict genetic differentiation in Namibian spiders (Ariadna: Segestriidae) and explain their behavior

The Namib Desert is a biodiversity hotspot for many invertebrates, including spiders. Tube‐dwelling spiders belonging to the Ariadna genus are widespread in gravel plains. These sit‐and‐wait predators share a particular behavior, as they spend their life in tunnels in the soil, surrounding the entrance of their burrow with stone rings. We investigated five spider populations taking into account environmental parameters, functional traits, and molecular data. We have chosen the temperature at the soil surface and at the bottom of the burrow, the air humidity, and the soil granulometry to define the environment. The chosen functional traits were the diameter and depth of the burrows, the ratio between weight and length, the thermal properties of their silks, and the number of ring elements. The molecular branch lengths and the evolutionary distance emerging from cytochrome oxidase I gene sequences summarized the molecular analysis. Our study highlights a strong coherence between the resulting evolutionary lineages and the respective geographical distribution. Multivariate analyses of both environmental and molecular data provide the same phylogenetic interpretation. Low intrapopulation sequence divergence and the high values between population sequence divergence (between 4.9% and 26.1%) might even suggest novel taxa which deserve further investigation. We conclude that both the Kimura distance and the branch lengths are strengthening the environmental clustering of these peculiar sites in Namibia.     

Comparison of quasisteady-state performance of the DEAMOX process under intermittent and continuous feeding and different nitrogen loading rates

The recently developed denitrifying ammonium oxidation (DEAMOX) process combines the anammox reaction with autotrophic denitrifying conditions using sulfide as an electron donor for the production of nitrite from nitrate within an anaerobic biofilm. This paper compares a quasisteady-state performance of this process for treatment of baker's yeast wastewater under intermittent and continuous feeding and increasing nitrogen loading rate (NLR) from 300 till 858 mg N/L/d. The average total nitrogen removal slightly decreased on increasing the NLR: from 86 to 79% (intermittent feeding) and from 87 to 84% (continuous feeding). The better performance under continuous feeding was due to a more complete nitrate removal in the former case whereas the ammonia removal was similar for both feeding regimes under the comparable NLR. A possible explanation can be that, during continuous feeding (simultaneous supply of nitrate and sulfide), there were less mass transfer limitations for sulfide oxidizing denitrifiers presumably located in the outer layer of sludge aggregates. On the contrary, the ammonia oxidisers presumably located inside the aggregates apparently suffered from nitrite mass transfer limitations under both the feedings. The paper further describes some characteristics of the DEAMOX sludge.     

Purification of the intact monomeric 110 kDa form of the androgen receptor from calf uterus to near homogeneity

In the present study, culf uterine tissue has been used for isolation of androgen receptors. This tissue appeared to be a favourable source for large-scale purification of androgen receptors, because of the relatively high level of androgen receptors and the low concentration of proteolytic enzymes. The purification involved differential phosphocellulose and DNA affinity chromatography as first steps. The non-transformed receptor was passed through these matrices in order to remove contaminating DNA-binding proteins. After a transformation step to the DNA-binding state, the receptor was bound to DNA cellulose and subsequently eluted with MgCl₂. A 0.5% pure androgen receptor preparation was obtained. Photoaffinity labelling with [³H]R1881 (methyltrienolone) was used to determine the size of the receptor at this stage of purification and during the following steps. Subsequently, isoelectric focussing of the partially purified androgen receptor preparation in an aqueous glycerol gradient was performed. In this step, the progesterone receptor, which is copurified with the androgen receptor protein during the first part of the purification procedure, focussed at pH 5.5, while the androgen receptor could be isolated at pH 5.8. The isoelectric focussing procedure could be applied in a preparative way for further purification of androgen receptors. After this step an approx. 8% pure preparation was obtained. Polyacrylamide gel electrophoresis of S-carboxymethylated androgen receptor was used as the final purification step. The [³H]methyltrienolone labelled androgen receptor from calf uterus was purified to homogeneity and consisted of one polypeptide with a molecular mass of 110 kDa.     

Differential effects of chronic agonist administration on mu-opioid receptor- and muscarinic receptor-regulated adenylate cyclase in rat striatal neurons.

In cultured rat striatal neurons exposed to 10 microM morphine or oxotremorine for 24 hours, we observed an increased (about 30%) dopamine D1 receptor-stimulated cyclic AMP production, whereas no desensitization of mu-opioid receptor or muscarinic cholinergic receptor was found. However, whereas upregulation of dopamine D1 receptor-stimulated adenylate cyclase activity upon 7 days morphine exposure was at least as pronounced as observed after 24 hours of exposure to the opioid, this adaptive phenomenon was virtually absent following one week of oxotremorine treatment. This reduced adenylate cyclase sensitization upon 7 days oxotremorine exposure appeared to coincide with desensitization of muscarinic cholinergic receptors. A possible role of the resistance of mu receptors to desensitization and the (resulting) upregulation of the neuronal adenylate cyclase system upon chronic receptor activation in the development of opiate tolerance and dependence is suggested.     

Augmentation mammaplasty in male-to-female transsexuals

Hormonal therapy and gender-confirming surgery are the treatments of choice in appropriately selected male-to-female transsexuals. Penectomy and vaginoplasty are the paramount surgical requests of the male transsexual, but breast enlargement greatly increases subjective feelings of femininity. There are only limited reports on augmentation mammaplasty in male transsexuals, and hardly any attention has been paid to the differences between the female mammary anatomy and its male counterpart. The basic anatomic and surgical considerations of augmentation mammaplasty for 201 male-to-female transsexuals who were operated on from 1979 to 1997 are reviewed and discussed. They include the differences between male and female anatomy and how to feminize the male chest, the results of hormonal therapy and the proper timing of surgery, the choice of implant size and surgical approach, the results that may be expected after surgery, and the implications of all mentioned on the long-term outcome and follow-up after augmentation mammaplasty. Because the referring doctor may not check on the breasts or may not be trained to examine augmented breasts for pathologic conditions, the mammaplastic surgeon has an obligation to ensure the proper follow-up of these patients.     

Are men and women really so different?

Distinct differences in the behaviour and preferences of men and women have conventionally been attributed to Trivers' powerful insights regarding the impact of parental investment on sexual selection and mating systems. This has spawned a huge literature about the evolutionary significance of human sex differences. But are men and women really so different? An elegant new study shows that men and women are strikingly similar in their mate preferences. Have conventional models blinded us to the obvious, and precluded the posing of far more interesting questions?     

The Proteome Analysis database: a tool for the in silico analysis of whole proteomes

The Proteome Analysis database (http://www.ebi.ac.uk/proteome/) has been developed by the Sequence Database Group at EBI utilizing existing resources and providing comparative analysis of the predicted protein coding sequences of the complete genomes of bacteria, archeae and eukaryotes. Three main projects are used, InterPro, CluSTr and GO Slim, to give an overview on families, domains, sites, and functions of the proteins from each of the complete genomes. Complete proteome analysis is available for a total of 89 proteome sets. A specifically designed application enables InterPro proteome comparisons for any one proteome against any other one or more of the proteomes in the database.     

p116Rip is a novel filamentous actin-binding protein

p116Rip is a ubiquitously expressed protein that was originally identified as a putative binding partner of RhoA in a yeast two-hybrid screen. Overexpression of p116Rip in neuroblastoma cells inhibits RhoA-mediated cell contraction induced by lysophosphatidic acid (LPA); so far, however, the function of p116Rip is unknown. Here we report that p116Rip localizes to filamentous actin (F-actin)-rich structures, including stress fibers and cortical microfilaments, in both serum-deprived and LPA-stimulated cells, with the N terminus (residues 1-382) dictating cytoskeletal localization. In addition, p116Rip is found in the nucleus. Direct interaction or colocalization with RhoA was not detected. We find that p116Rip binds tightly to F-actin (Kd approximately 0.5 microm) via its N-terminal region, while immunoprecipitation assays show that p116Rip is complexed to both F-actin and myosin-II. Purified p116Rip and the F-actin-binding region can bundle F-actin in vitro, as shown by electron microscopy. When overexpressed in NIH3T3 cells, p116Rip disrupts stress fibers and promotes formation of dendrite-like extensions through its N-terminal actin-binding domain; furthermore, overexpressed p116Rip inhibits growth factor-induced lamellipodia formation. Our results indicate that p116Rip is an F-actin-binding protein with in vitro bundling activity and in vivo capability of disassembling the actomyosin-based cytoskeleton.     

Sympathetic control of the cardiovascular response to acute hypoxemia in the chick embryo

In response to an acute hypoxemic insult, the mammalian fetus shows a redistribution of the cardiac output in favor of the heart and brain. Peripheral vasoconstriction contributes to this response and is partly mediated by the release of catecholamines. Two mechanisms of catecholamine release in the fetus are reported: 1) neurogenic sympathetic stimulation and 2) a nonneurogenic mechanism via a direct effect of hypoxemia on chromaffin tissues. In the present study, the effects of sympathetic blockade on plasma catecholamine release and cardiac output distribution in response to acute hypoxemia were studied in the chick embryo at different stages of incubation. Only at the end of the incubation period, sympathetic blockade markedly attenuated the increase in plasma catecholamine concentrations and resulted in a greater fraction of the cardiac output distributed to the carcass. However, these effects did not prevent a significant increase in cardiac output to the brain and heart during acute hypoxemia. These data imply that in the chick embryo the contribution of neurogenic mechanisms to the catecholaminergic response to acute hypoxemia becomes greater by the end of the incubation period.