Across-shore distribution of Ocypode quadrata burrows in relation to beach features and human disturbance

Spatial distribution patterns of the ghost crab Ocypode quadrata were analysed using different approaches at one disturbed and two preserved reflective sandy beaches of the Mexican Caribbean. We used spatial correlation analysis to describe the across-shore distribution of O. quadrata and their patch dynamics by beach and sampling time. In addition, we analysed the across-shore variability of habitat extent of O. quadrata (habitat envelope) and its relation to human disturbance and beach features. The spatial structure of burrow density was consistent through time, showing a bimodal distribution with very low abundance in the mid distribution range and a discrete increment of burrows to landward. Nonetheless, the size of patches varied temporally for the three beaches. Burrow size increased from seaward to landward. The location of the first burrow and the habitat envelope varied among sampling times and beaches. The location of the first burrow is mostly mediated by the swash climate, while the habitat envelope is mainly controlled by the level of human disturbance. Despite the low number of disturbed and control beaches, our results suggest that the habitat envelope could be included in future studies when using ghost crabs as indicators of human disturbance. Polynomial models and variographic analysis proved to be useful tools to describe the across-shore distribution and patch dynamics of the ghost crab.     

Phoretic behaviour of Attacobius attarum (Roewer, 1935) (Araneae: Corinnidae: Corinninae) dispersion not associated with predation?

Attacobius attarum spiders exhibit a phoretic behaviour on the winged sexual of Atta leaf-cutting ants during their mating flight. However, it is unclear if this behaviour is for dispersion or to facilitate the predation of ants in the new colonies. A nest of Atta sexdens was monitored on the day of the mating flight, and the winged ants, as well as the spiders, were collected. The results obtained corroborate the hypothesis that phoretic behaviour is commonly used for dispersion of the spider A. attarum, predominantly females. Of these spiders, 64 individuals of A. attarium were collected, of which 62 were females (96.9%) and two were males (3.1%). Regarding the winged leaf-cutting ants sampled, 378 females and 361 males were collected, totaling 739 individuals. Of these, 64 individuals (8.7%) had a spider attached to its back for phoretic dispersal and none was observed on the queens after the nuptial flight. In our study, A. attarum females perform phoretic dispersal into the environment on winged leaf-cutting ants but do not settle in the new nests.     

Focus on molecular events in the anterior chamber leading to glaucoma

Primary open-angle glaucoma is a multifactorial disease that affects the retinal ganglion cells, but currently its therapy is to lower the eye pressure. This indicates a definite involvement of the trabecular meshwork, key region in the pathogenesis of glaucoma. This is the first target of glaucoma, and its functional complexity is a real challenge to search. Its functions are those to allow the outflow of aqueous humor and not the reflux. This article describes the morphological and functional changes that happen in anterior chamber. The “primus movens” is oxidative stress that affects trabecular meshwork, particularly its endothelial cells. In these develops a real mitochondriopaty. This leads to functional impotence, the trabecular meshwork altering both motility and cytoarchitecture. Its cells die by apoptosis, losing barrier functions and altering the aqueous humor outflow. All the morphological alterations occur that can be observed under a microscope. Intraocular pressure rises and the malfunctioning trabecular meshwork endotelial cells express proteins that completely alter the aqueous humor. This is a liquid whose functional proteomics complies with the conditions of the trabecular meshwork. Indeed, in glaucoma, it is possible detect the presence of proteins which testify to what occurs in the anterior chamber. There are six classes of proteins which confirm the vascular endothelium nature of the anterior chamber and are the result of the morphofunctional trabecular meshwork decay. It is possible that, all or in part, these proteins can be used as a signal to the posterior pole.     

Planning of dynamically feasible trajectories for translational, planar, and underconstrained cable-driven robots

Extensively studied since the early nineties, cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes. In particular, underconstrained and planar cable robots can find application in several fields, and specif- ically, in the packaging industry. The planning of dynamically feasible trajectories （i.e., trajectories along which cable slackness and excessive tensions are avoided） is particularly challenging when dealing with such a topology of cable robots, which rely on gravity to maintain their cables in tension. This paper, after stressing the current relevance of cable robots, presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path. Such a new formulation of the method is based on a parametric expression of cable tensions. The computed kine- matic limits can then be incorporated into any trajectory planning algorithm. The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions. The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions. Finally, some aspects related to the practical implementation of the method are discussed.     

打开中国遗传学历史之门

我国6个单位即中国医学科学院医学生物学研究所、上海复旦大学、哈尔滨医科大学、中国科学院遗传所、医科院肿瘤所和上海第二医科大学附属瑞金医院的遗传学家大力协作，利用高度多态性的遗传学标志对中国各民族的源流关系及其与世界各民族的进化关系进行了分析，是中国人类基因组多样性计划的一个重大成果，不仅发表于《美国国家科学院院报》（ProceedingsoftheNationalAcademyofSciences）上，赢得了世界人类基因组多样性计划的权威Cavalli－Sforza和Riazza分别在《美国国家科学院院报》和《自然》（Nature）上撰文评述，而且还入选了…     

Neurexins and neuroligins: synapses look out of the nervous system

The scientific interest in the family of the so-called nervous vascular parallels has been growing steadily for the past 15 years, either by addition of new members to the group or, lately, by deepening the analysis of established concepts and mediators. Proteins governing both neurons and vascular cells are known to be involved in events such as cell fate determination and migration/guidance but not in the last and apparently most complex step of nervous system development, the formation and maturation of synapses. Hence, the recent addition to this family of the specific synaptic proteins, Neurexin and Neuroligin, is a double innovation. The two proteins, which were thought to be “simple” adhesive links between the pre- and post-synaptic sides of chemical synapses, are in fact extremely complex and modulate the most subtle synaptic activities. We will discuss the relevant data and the intriguing challenge of transferring synaptic activities to vascular functions.     

Isoform specific phosphorylation of p53 by protein kinase CK1

The ability of three isoforms of protein kinase CK1 (α, γ₁, and δ) to phosphorylate the N-terminal region of p53 has been assessed using either recombinant p53 or a synthetic peptide reproducing its 1–28 sequence. Both substrates are readily phosphoylated by CK1δ and CK1α, but not by the γ isoform. Affinity of full size p53 for CK1 is 3 orders of magnitude higher than that of its N-terminal peptide (K _m 0.82 μM vs 1.51 mM). The preferred target is S20, whose phosphorylation critically relies on E17, while S6 is unaffected despite displaying the same consensus (E-x-x-S). Our data support the concept that non-primed phosphorylation of p53 by CK1 is an isoform-specific reaction preferentially affecting S20 by a mechanism which is grounded both on a local consensus and on a remote docking site mapped to the K²²¹RQK²²⁴ loop according to modeling and mutational analysis.     

Variable selection in STAR models with neighbourhood effects using genetic algorithms

In this paper we deal with the problem of variable selection in spatiotemporal autoregressive (STAR) models with neighbourhood effects. We propose a procedure to carry out the selection process, taking into account the uncertainty associated with estimation of the parameters and the predictive behaviour of the compared models, in order to give more realism to the analysis. We set up a multi‐objective programming problem that combines the use of different criteria to measure both these aspects. We use genetic algorithms which are very flexible and suitable for our multicriteria decision problem. In particular, the procedure allows us to estimate the number of spatial and temporal nearest neighbours as well as their relative effects. The methodology is illustrated through an application to the real estate market of Zaragoza. Copyright © 2010 John Wiley & Son, Ltd.     

Mapping autism risk loci using genetic linkage and chromosomal rearrangements

Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,181 [corrected] families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.     

Use of Systems Methodologies in the UK and Spain: A Sample Survey

The emergence and the use of the so-called Management Sciences Methodologies has been one of the major recent developments in the field of Management Practice. The issues of the cultural dimensions of a particular country and its relevance in managerial practices have attracted substantial attention over recent years. This paper attempts to compare the usage of management sciences methods from the Hard and Soft spectrum in two countries that have quite distinctive managerial and cultural traditions: the UK and Spain. It reports on the results of a mail questionnaire administered to MBA graduates working in management consultancy in both countries.