A model of the gelada socio-ecological system

Data from three populations of gelada baboons are used to generate a model of the species' socio-ecology that relates time budget requirements to group size, day journey length, and relevant environmental parameters. The model is used to examine the range of environmental conditions under which gelada could survive. This analysis indicates that a grazing primate like the gelada would run out of available time for foraging at just above and just below the altitudes at which they are now found. This suggests that, contrary to previous supposition, gelada were not driven into a retreat habitat by more competitivePapio baboons, but rather withdrew from lower altitude habitats because they could not survive under these conditions as the climate deteriorated during the Holocene.     

Presence of the large aquatic snake Palaeophis africanus in the middle Eocene marine margin of the Congo Basin,Cabinda, Angola

Ten isolated snake vertebrae from Landana and Sassa-Zao, Cabinda Exclave, Angola, present a “primitive” grade morphology with a weak lateral compression and do not belong to Palaeophis aff. typhaeus as originally referred to. They well belong to a single taxon and are here attributed to Palaeophis africanus for which the intracolumnar variation is described and illustrated. This species is Lutetian (middle Eocene) in age and originates from a marine coastal environment confirming again the aquatic capabilities of palaeophiid snakes. It represents the third largest species of Palaeophis with P. colossaeus and P. maghrebianus to which it is closely related in our tentative phylogenetic analysis, indicating that these three taxa could belong to an African clade. This study also contributes to the debate on the existence of primitive and advanced grades among palaeophiid snakes. Palaeophis presents laterally compressed anterior trunk vertebrae that could have been often erroneously considered as representing advanced grade species and potential parataxonomy.     

The influence of space and time on the evolution of altruistic defence: the case of ant slave rebellion

How can antiparasite defence traits evolve even if they do not directly benefit their carriers? An example of such an indirect defence is rebellion of enslaved Temnothorax longispinosus ant workers against their social parasite Temnothorax americanus, a slavemaking ant. Ant slaves have been observed to kill their oppressors' offspring, a behaviour from which the sterile slaves cannot profit directly. Parasite brood killing could, however, reduce raiding pressure on related host colonies nearby. We analyse with extensive computer simulations for the Temnothorax slavemaker system under what conditions a hypothetical rebel allele could invade a host population, and in particular, how host–parasite dynamics and population structure influence the rebel allele's success. Exploring a wide range of model parameters, we only found a small number of parameter combinations for which kin selection or multilevel selection could allow a slave rebellion allele to spread in the host population. Furthermore, we did not detect any cases in which the reduction of raiding pressure in the close vicinity of the slavemaker nest would substantially contribute to the inclusive fitness of rebels. This suggests that slave rebellion is not costly and perhaps a side‐effect of some other beneficial trait. In some of our simulations, however, even a costly rebellion allele could spread in the population. This was possible when host–parasite interactions led to a metapopulation dynamic with frequent local extinctions and recolonizations of demes by the offspring of few immigrants.     

Palaeoenvironments and the origin of hominid bipedalism

Abstract

It has long been accepted that hominids emerged during the Pliocene in a savannah environment in which a terrestrial quadruped gradually developed bipedal adaptations. However, data from the Late Miocene (i.e. 7–7.5 Ma), including detailed palaeontological and biogeochemical studies, suggest that our earliest Upper Miocene ancestors inhabited well-wooded to forested environments where they could have spent a certain amount of time in the trees. A plausible type of ecosystem in which upright posture and bipedal locomotion could have emerged is represented by Miombo Woodland, in which vertical arboreal supports predominate and trees are separated from each other by gaps. Subsequently hominids dispersed into the Savannah as accomplished bipeds, but retained the ability to climb trees. This scenario is compatible with the postcranial anatomy of Australopithecus, including its femoral elongation, body proportions, manual precision grip (also present in 6-million-year-old Orrorin) and a non-prehensile hallux.     

Development of a bioautographic method for the detection of lipase inhibitors

An autobiographic method based on the thin layer chromatogram was developed by using the chemical system that comprises p-Nitrophenyl butyrate and bromothymol blue for detecting the lipase inhibitor. Lipase inhibitory zones were visualized as blue spots against the greenish yellow background. This method could able to detect the well known lipase inhibitor, orlistat up to the concentration of 1 ng which is better than the earlier method. This method could also able to detect the lipase inhibition activities from the un-explored species of Streptomyces. The developed method can be used not only for the screening of unknown samples for the lipase inhibitors but also for the purification of the lipase inhibitors from the unknown samples.     

Effects of Lac Operon Activation,Deletion of the Yhha Gene,and the Removal of Oxygen on the Ultra-Weak Photon Emission of Escherichia coli

We observed a relation between gene activity and ultra-weak photon emission (UPE). By comparing the UPEs of E. coli with the LacI gene present and deleted we found that more gene activity produced higher UPE. This relation was further confirmed by studying the UPE of the E. coli with and without the Yhha gene. We interpreted that a higher aminoacyl t-RNA synthetase activity, which used ATP from the respiratory chain, could increase the emission. Satisfying the increased need of ATP by the E. coli through an increase of respiratory chain activity, which has reactive oxygen species (ROS) as a byproduct, results in a higher rate of photon emission. To ensure that oxygen is at the origin of this emission, we replaced the air by pure nitrogen. After 30?min, it was observed that the emission levels equaled the emission levels of the sterile medium. We could therefore conclude that the source of the photon emission would be affected by genetic activity and is oxygen related.     

九万山自然保护区森林植被涵养水源效益的初步研究

研究与分析了广西九万山自然保护区森林植被在涵养水源方面的生态效益。结果表明,该保护区森林通过林地土壤根际层、枯落物层和林冠层等三个水文层次,贮蓄的雨量为18 368.07×104m3／a,直接或间接带来的生态社会效益价值为2.44亿元;水源涵养效益显著,对维护地方生态安全极为重要。     

Restoration of complex V deficiency caused by a novel deletion in the human TMEM70 gene normalizes mitochondrial morphology

We report a fragmented mitochondrial network and swollen and irregularly shaped mitochondria with partial to complete loss of the cristae in fibroblasts of a patient with a novel TMEM70 gene deletion, which could be completely restored by complementation of the TMEM70 genetic defect. Comparative genomics analysis predicted the topology of TMEM70 in the inner mitochondrial membrane, which could be confirmed by immunogold labeling experiments, and showed that the TMEM70 gene is not restricted to higher multi-cellular eukaryotes. This study demonstrates that the role of complex V in mitochondrial cristae morphology applies to human mitochondrial disease pathology.     

Isolation of a Serratia marcescens mutant which is an efficient recipient for the E. coli episome

Summary A Serratia marcescens mutant, which is an efficient recipient for the Escherichia coli episome (F' plasmid), was isolated after mutagenesis by N-methyl-N'-nitro-N-nitrosoguanidine (NTG). Episomes could be maintained in the mutant cell under conditions selective for a gene on the plasmid. This S. marcescens mutant could also be transformed with pBR 322 DNA at a frequency higher than that of the parental strain.     

Theoretical approach to the functional optimisation of spiriferide brachiopod shell: Optimum morphology of sulcus

Evidence suggests that biological forms that provide physiological and autecological functions have evolved to adapt to environmental conditions and to optimise requisite morpho-functions. We examined whether shell morphology is functionally optimised to generate passive feeding flow in the Devonian spiriferide brachiopod Paraspirifer bownockeri. This study was based on quantitative results from a computational fluid dynamics simulation and the Lagrangian multiplier method. We estimated the optimum development of the ventral median shell depression, which is called the sulcus, by minimising the pressure difference along the gape. This estimation was made under the constraint that the number of spiral flow rotations must be greater than one, which is effective for spiriferide feeding because of its alignment with the spiral lophophore. During mathematical optimisation, the equation resulted in a suitable flow velocity of approximately 0.1 m/s. At this velocity, the pressure difference was minimised, regardless of sulcus development. The constraint equation showed that the number of spiral flow rotations increased with sulcus development. The optimal solution was similar to the original sulcus form of Paraspirifer under an ambient flow of approximately 0.1 m/s. This result suggests that the variation of shell outline in spiriferids could provide a variety of preferential conditions for ambient flow and that the flow intensity could be adjusted by sulcus development to generate a robust passive feeding flow along the spiral feeding organs.     

Direct incorporation and extension of a fluorescent nucleotide through rolling circle DNA amplification for the detection of microRNA 24-3P

We designed and synthesized several fluorescent nucleotides from thiophene, anthracene and pyrene, which have different sizes, and screened their incorporation and extension capability during the rolling circle amplification of DNA. The thiophene-based fluorescent nucleotide (dUthioTP) could highly incorporate and extended into the rolling circle DNA product, while other fluorescent nucleotides (dUanthTP, and dUpyrTP) could not. This dUthioTP fluorescent nucleotide could be used for the detection of miRNA 24-3P, which is related PRRSV. This direct labeling system during rolling circle DNA amplification exhibited an increased fluorescence signal showing gel formation for the detection of miRNA 24-3P. This direct labeling system is a very simple and cost-efficient method for the detection miRNA 24-3P and also exhibited highly sensitive and selective detection properties.     

Chaperone-Mediated Folding and Maturation of the Penicillin Acylase Precursor in the Cytoplasm of Escherichia coli

Expression of the leaderless pac gene (LL pac), which lacks the coding region for the signal peptide of penicillin acylase (PAC), in Escherichia coli was conducted. It was demonstrated that the PAC precursor, proPAC, can be produced and even processed to form mature PAC in the cytoplasm, indicating that the posttranslational processing steps for PAC maturation can occur in both the periplasm and the cytoplasm of E. coli. The outcome of proPAC folding and PAC maturation could be affected by several factors, such as inducer type, proPAC formation rate, and chaperone availability. Misfolding of proPAC in the cytoplasm could be partially resolved through the coexpression of cytoplasmic chaperones, such as trigger factor, GroEL/ES, or DnaK/J-GrpE. The three chaperones tested showed different extents of the effect on proPAC solublization and PAC maturation, and trigger factor had the most prominent one. However, the chaperone-mediated solublization of proPAC did not guarantee its maturation, which is usually limited by the first autoproteolytic step. It was observed that arabinose could act as an effective inducer for the induction of LL pac expression regulated by the lac-derived promoter system of trc. In addition, PAC maturation could be highly facilitated by arabinose supplementation and coexpression of trigger factor, suggesting that the coordination of chaperone systems with proper culture conditions could dramatically impact recombinant protein production. This study suggests that folding/misfolding of proPAC could be a major step limiting the overproduction of PAC in E. coli and that the problem could be resolved through the search for appropriate chaperones for coexpression. It also demonstrates the analogy in the issues of proPAC misfolding as well as the expression bottleneck occurring in the cytoplasm (i.e., LL pac expression) and those occurring in the periplasm (i.e., wild-type pac expression).     

The present status of the ‘carrier hypothesis’ for chemosensory recognition of genetic individuality

The hypothesis that soluble MHC Class I molecules could act as the vector which transports MHC‐specific odours from the blood into the urine was put forward some ten years ago (Singh, Brown Roser, 1987). Here, I summarise new evidence in favour of the hypothesis. ‘We propose that the ability of MHC Class I molecules to associate in a selective way with other small molecules could also be the mechanism by which a unique mixture of volatile, endogenous metabolites is transported by [soluble] class I MHC glycoproteins from the blood into the urine’ (Singh, Brown Roser, 1987). This revised version was published online in July 2006 with corrections to the Cover Date.     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the reconstruction of phylogenetic transformations. The origin of the arthropods

The conditions are outlined under which the body construction of annelids could have been transformed into that of arthropods. As an adaptation to a vagile life and an uptake of food by filtering particles from the sediment, the body was more and more flattened. Thus lateral protrusions, the subsequent pleurotergites, developed, and the parapodia were shifted to a more ventral position and could differentiate into the branched limbs typical for arthropods. This is the condition under which parts of the body wall were kept immobile, so that they could become sclerotized in the form of rigid plates.     

Cepred: Predicting the Co-Expression Patterns of the Human Intronic microRNAs with Their Host Genes

Identifying the tissues in which a microRNA is expressed could enhance the understanding of the functions, the biological processes, and the diseases associated with that microRNA. However, the mechanisms of microRNA biogenesis and expression remain largely unclear and the identification of the tissues in which a microRNA is expressed is limited. Here, we present a machine learning based approach to predict whether an intronic microRNA show high co-expression with its host gene, by doing so, we could infer the tissues in which a microRNA is high expressed through the expression profile of its host gene. Our approach is able to achieve an accuracy of 79% in the leave-one-out cross validation and 95% on an independent testing dataset. We further estimated our method through comparing the predicted tissue specific microRNAs and the tissue specific microRNAs identified by biological experiments. This study presented a valuable tool to predict the co-expression patterns between human intronic microRNAs and their host genes, which would also help to understand the microRNA expression and regulation mechanisms. Finally, this framework can be easily extended to other species.