Prevalence of potentially pathogenic culturable bacteria on eggshells and in cloacae of female Pied Flycatchers in a temperate habitat in central Spain

ABSTRACT Bacteria grow on avian eggshells and thus can potentially cause diseases in developing embryos. Little is known about culturable bacteria colonizing avian eggshells in free‐living birds, with most studies restricted to poultry. Our objective was to examine the culturable bacterial array growing on eggshells during incubation that could negatively affect hatching success of Pied Flycatchers (Ficedula hypoleuca) in a temperate montane habitat in central Spain. Cloacal culturable bacteria of females were also analyzed because bacteria can be vertically transmitted from females to eggs. We used fecal samples as surrogates of cloacal samples due to the small size of sampled birds. We found that eggshells and female cloacae of Pied Flycatchers harbored 24 and 40 bacterial families and species, respectively, but only a few in each clutch and each cloaca. Rod‐shaped gram‐negative bacteria and bacteria in the family Pseudomonadaceae were the most common bacteria on eggshells during early and late incubation and in female cloacae. Although based on small sample sizes, we found that females with rod‐shaped gram‐negative bacteria in their cloacae laid eggs that also had these bacteria, providing possible evidence for vertical transmission. We found no evidence for vertical transmission of Pseudomonadaceae, suggesting a possible environmental source for these bacteria. The prevalence of bacterial morphological types and major taxonomical categories on eggshells did not vary from early to late stages of incubation, providing support for the hypothesis that incubation may have bacteriostatic effects on bacterial proliferation on eggshells. Despite being primary egg invaders in poultry, we detected no effects of culturable Pseudomonadaceae or Pseudomonas luteola on hatching success. Our study represents the first to examine the culturable bacteria growing on the eggshells of a wild bird in a temperate habitat and additional studies based on culture‐independent techniques are required to confirm our results.     

Island evolutionary biogeography: analysis of the weevils (Coleoptera: Curculionidae) of the Falkland Islands (Islas Malvinas)

Aim I analysed distributional and phylogenetic information on weevils (Coleoptera: Curculionidae) from the Falklands, and integrated it with molecular, palaeontological and geological information to infer a geobiotic scenario. Location Falkland Islands (Islas Malvinas). Methods The panbiogeographical analysis was based on data on 23 Falkland species and their related taxa from southern South America. For the cladistic biogeographical analysis I analysed six weevil taxa for which phylogenetic hypotheses are available (the generic groups Cylydrorhinus, Strangaliodes and Falklandius, and the genera Antarctobius, Germainiellus and Puranius). Results from this analysis were compared with previous regionalizations. Cenocrons (sets of taxa that share the same biogeographical history) were identified by considering temporal information provided by fossils and molecular clocks. Finally, a geobiotic scenario was proposed by integrating the available information. Results Six generalized tracks were detected: Maule–Valdivian forests, Magellanic forest, Magellanic moorland, Falkland Islands, Magellanic forest–Magellanic moorland, and Magellanic forest–Falkland Islands. A node was identified in the Magellanic forest, based on the overlap of two generalized tracks. A single general area cladogram was obtained, implying the following sequence: (Magellanic moorland (Maule–Valdivian forests (Magellanic forest, Falkland Islands))). The Falklands are classified here as a biogeographical province in the Austral realm, Andean region and Subantarctic subregion. Falkland weevils seem to belong to a single Subantarctic cenocron. The sequence of events deduced implies the following steps: development of the Subantarctic biota in southern South America, arrival of the Falkland crustal block from South Africa in the Early Cretaceous, geodispersal of the Subantarctic cenocron from southern South America to the Falklands during the Early Oligocene, vicariance of the Magellanic moorland, vicariance of the Maule–Valdivian forests, and final vicariance between the Magellanic forest and the Falkland Islands. Main conclusions The biotic components identified support the connection of the Falkland weevils with the Magellanic forest. Falkland weevils belong to a single cenocron, dated to at least the Early Oligocene, when geodispersal from southern South America may have occurred. An older African cenocron may have been replaced completely by the Subantarctic one when the proto‐Falklands made contact with the Patagonian continental shelf. A geobiotic scenario implying vicariance events related to sea‐level variations could explain the distributional patterns analysed herein.     

Understorey plant community assemblage of Australian Eucalyptus woodlands under elevated CO2 is modulated by water and phosphorus availability

水分和磷调控的澳大利亚桉树林林下植物群落组合对二氧化碳浓度升高的响应 鉴于林下植物群落具有的关键性功能作用和全球范围内巨大的森林覆盖面积,研究林下群落对 CO₂浓度升高(eCO₂)的响应以及土壤资源在这些响应中的作用,对于了解CO₂浓度升高对森林生态系统造成的影响非常重要。本研究评估了在澳大利亚东部磷有限的桉树林林下群落中,两种限制性的资源(即水分和磷)在发芽、物候、覆盖率、群落组成和叶片性状等方面对eCO₂响应的作用。我们收集了含有当地土壤种子库的土壤,在温室条件下种植实验性的林下植物群落。研究结果表明,添加磷提高了植物的总体覆盖率,特别是在生长期的最初4 周以及水分含量高的条件下,而且该响应是由植物群落中的类禾本科植物所驱动。然而,随着实验的进行,不同处理方法之间的差异逐渐减小,所有处理在大约11周后均达到了80%左右的植物覆盖率。相反,植物覆盖率并未受到eCO₂ 的影响。多元分析结果反映出植物群落组成随时间的变化,盆栽从以裸土为主变为以高覆盖率的多样化群落为主。但是在实验过程中,磷的添加以及水分可利用性和CO₂之间的相互作用都对植物群落随时间的变化轨迹有所影响。CO₂浓度的升高也增加了群落水平的比叶面积,这表明植物群落对eCO₂的功能适应可能发生在成分响应开始之前。鉴于我们用种子库培育的林下群落对eCO₂ 的响应随着时间的推移而有 所变化,并且受到与磷和水分可利用性的相互作用的调节。我们的结果表明,在水分含量有限的系统中, 特别是在土壤养分可利用性低所导致的生产力响应受限的情况下,CO₂浓度的升高在塑造植物群落方面作用有限。     

The function of small RNAs in plant biotic stress response

Small RNAs(s RNAs) play essential roles in plants upon biotic stress. Plants utilize RNA silencing machinery to facilitate pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity to defend against pathogen attack or to facilitate defense against insect herbivores. Pathogens, on the other hand, are also able to generate effectors and s RNAs to counter the host immune response. The arms race between plants and pathogens/insect herbivores has triggered the evolution of s RNAs,RNA silencing machinery and pathogen effectors. A great number of studies have been performed to investigate the roles of s RNAs in plant defense, bringing in the opportunity to utilize s RNAs in plant protection. Transgenic plants with pathogen-derived resistance ability or transgenerational defense have been generated, which show promising potential as solutions for pathogen/insect herbivore problems in the field. Here we summarize the recent progress on the function of s RNAs in response to biotic stress, mainly in plant-pathogen/insect herbivore interaction,and the application of s RNAs in disease and insect herbivore control.     

Structural analysis of the N‐terminal fragment of the antiangiogenic protein endostatin: A molecular dynamics study

Endostatin is a potent antiangiogenic protein derived from the noncollagenous domain 1 (NC1) of collagen XVIII. The mechanism by which endostatin exerts its antiangiogenic effect is still incompletely understood. It has been shown that the 27 amino acid N‐terminal fragment of murine endostatin has antitumor, antimigration, and antipermeability activities comparable to the full soluble protein. To understand how this peptide can exert such elaborate function, we performed structural analysis using molecular dynamics to evaluate the behavior of this fragment in aqueous environment. Here, we show that the N‐terminal peptide of murine endostatin is able to assume a well‐defined structure, folding into a zinc‐dependent β‐hairpin conformation. Analyzing the folding mechanism, we were able to understand why the N‐terminal peptide of human endostatin with the same length failed to acquire a stable conformation. Conversely, we were able to predict the successful folding of the R4Q mutant and of a shorter form of the human peptide with 25 residues. Finally, we show that the β‐hairpin conformation assumed by the zinc‐bound peptide of murine endostatin has a high structural similarity with fragments of another family of angiogenesis inhibitors: the integrin‐binding portion of the NC1 domain of collagen IV. Indeed, our docking simulations show that arresten, canstatin, and the endostatin peptide bind to the same spot of αVβ3 integrin, suggesting similar interactions via a common binding site on this receptor. Proteins 2011;. © 2011 Wiley‐Liss, Inc.     

The impact of acquired brain damage in terms of epidemiology,economics and loss in quality of life

Background  

Patients with acquired brain damage (ABD) have suffered a brain lesion that interrupts vital development in the physical, psychological and social spheres. Stroke and traumatic brain injury (TBI) are the two main causes. The objectives of this study were to estimate the incidence and prevalence of ABD in the population of the Basque Country and Navarre in 2008, to calculate the associated cost of the care required and finally to assess the loss in health-related quality of life.     

Absolute configuration of eremophilanoids by vibrational circular dichroism

The absolute configurations (AC) of natural occurring 6-hydroxyeuryopsin (1), of its acetyl derivative 2, and of eremophilanolide 8 were confirmed by comparison of the experimental vibrational circular dichroism (VCD) spectra with theoretical curves generated from density functional theory (DFT) calculations. Initial analyses were carried out using a Monte Carlo searching with the MMFF94 molecular mechanics force field. All MMFF94 conformers were further optimized using DFT at the B3LYP/6-31G(d) level of theory, followed by calculations of their vibrational frequencies at the B3LYP/6-31G(d,p); the VCD spectra of 2 and 8 were also calculated at the B3PW91/DGDZVP level of theory. Good agreement between theoretical and experimental VCD curves unambiguously verified the 4S,5R,6S absolute configuration for 1 and 2, and the 1S,4S,5R,6S,8S,10S configuration for 8.