Percolation of Immobile Domains in Supercooled Thin Polymeric Films

We present an analysis of heterogeneous dynamics in molecular dynamics simulations of a thin polymeric film, supported by an absorbing structured surface. Near the glass transition "immobile" domains occur throughout the film, yet the probability of their occurrence decreasing with larger distance from the surface. Still, enough immobile domains are located near the free surface to cause them to percolate in the direction perpendicular to surface, at a temperature near the glass transition temperature. This result is in agreement with a recent theoretical model of glass transition

Bcl-XL Inhibits Membrane Permeabilization by Competing with Bax

Although Bcl-XL and Bax are structurally similar, activated Bax forms large oligomers that permeabilize the outer mitochondrial membrane, thereby committing cells to apoptosis, whereas Bcl-XL inhibits this process. Two different models of Bcl-XL function have been proposed. In one, Bcl-XL binds to an activator, thereby preventing Bax activation. In the other, Bcl-XL binds directly to activated Bax. It has been difficult to sort out which interaction is important in cells, as all three proteins are present simultaneously. We examined the mechanism of Bax activation by tBid and its inhibition by Bcl-XL using full-length recombinant proteins and measuring permeabilization of liposomes and mitochondria in vitro. Our results demonstrate that Bcl-XL and Bax are functionally similar. Neither protein bound to membranes alone. However, the addition of tBid recruited molar excesses of either protein to membranes, indicating that tBid activates both pro- and antiapoptotic members of the Bcl-2 family. Bcl-XL competes with Bax for the activation of soluble, monomeric Bax through interaction with membranes, tBid, or t-Bid-activated Bax, thereby inhibiting Bax binding to membranes, oligomerization, and membrane permeabilization. Experiments in which individual interactions were abolished by mutagenesis indicate that both Bcl-XL–tBid and Bcl-XL–Bax binding contribute to the antiapoptotic function of Bcl-XL. By out-competing Bax for the interactions leading to membrane permeabilization, Bcl-XL ties up both tBid and Bax in nonproductive interactions and inhibits Bax binding to membranes. We propose that because Bcl-XL does not oligomerize it functions like a dominant-negative Bax in the membrane permeabilization process

Wonderfully weird: the head anatomy of the armadillo ant, Tatuidris tatusia (Hymenoptera: Formicidae: Agroecomyrmecinae), with evolutionary implications

Tatuidris tatusia Brown & Kempf, 1968, the armadillo ant, is a morphologically unique species found in low to high elevation forests in regions of Central and South America. It is one of only two extant representatives of the subfamily Agroecomyrmecinae, and very little is known about the biology of these ants, which are almost exclusively collected from leaf litter and have rarely been seen alive. Here, we illuminate the functional morphology and evolution of this species via detailed anatomical documentation of their exceptionally modified head. We describe and illustrate the skeletomuscular system, digestive tract, and cephalic glands based on high-resolution micro-computed tomography scan data. We hypothesize that the modifications which produce the unusual “shield-like” head shape are the result of complex optimizations for mandibular power, physical protection, and balance. The most conspicuous cephalic features are the broadening of the frontal region and foreshortening of the postgenal region. The former characteristic is likely also associated with the lateral position of the antennal scrobe, the inverted antennal articulation, and the broad attachment surface for the mandibular adductor muscles. This head geometry also comes with a degree of internal restructuring of the tentorium and the antennal musculature, which have a unique configuration among ants studied so far. The mandibular blades, and their articulations and muscles, are highly distinctive compared with previously evaluated species. Using a 3D-printed model, we were able to hypothesize their entire range of motion as the mandibles fit tightly into the oral foramen. Finally, we compare T. tatusia across other related subfamilies and discuss the evolution of the Agroecomyrmecinae and other species-poor and phylogenetically isolated “relictual” lineages.journal articl

Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis.

Highlights: Feline antibodies against cryptic Aspergillus spp. cross react with an aspergillin containing A. fumigatus antigens. • Brachycephalic cats are prone to upper respiratory tract aspergillosis (URTA). • The agar gel immunodiffusion (AGID) assay has low sensitivity for diagnosis of URTA. • IgG ELISA has high sensitivity and specificity for diagnosis of URTA. • This study provides evidence that cats with URTA are systemically immunocompetent. Abstract Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA. Keywords: Aspergillosis; Aspergillus spp; Sino-nasal; Sino-orbital; Felinefunded by an Australian Companion Animal Health Foundation grant (015/201

Conserved Class of Queen Pheromones Stops Social Insect Worker Reproduction

Dissertação de mestrado em Gestão, apresentada à Faculdade de Economia da Universidade de Coimbra, sob a orientação de Patrícia Pereira da SilvaEm 2011, a crise política e financeira de Portugal atingiu um nível crítico, levando à queda do governo, assim como ao pedido de ajuda à denominada Troika, constituída pelo (Fundo Monetário Internacional, Banco Central Europeu e Comunidade Europeia). As recomendações da Troika sobre a política energética Portuguesa basearam-se em torno de medidas que potenciem a eficiência energética, ou seja, medidas que permitam poupar e otimizar consumo de energia. No entanto, sobre as energias renováveis, foi pedida especial atenção, em particular, em tecnologias menos desenvolvidas (incluindo o fotovoltaico), nas quais se deverá efetuar uma análise rigorosa em termos de custos e consequências para o preço da energia. Outra das recomendações da Troika passou por uma revisão em baixo do preço pago pela tarifa (Feed-in tariff), com o intuito de que esse valor não produza compensações alegadamente excessivas para os investidores neste setor. Atendendo às novas constrições anteriormente apresentadas, e aos elevados custo de investimento que as Fontes de Energias Renováveis apresentam, nomeadamente, no setor fotovoltaico, a respetiva avaliação económica assume um papel primordial. É, assim, objetivo desta dissertação estimar da forma mais correta a rendibilidade do investimento, sendo, para tal, desenvolvida uma metodologia de análise de projetos de investimento, usando o método discounted cash flow (DCF) – Free Cash Flow to the firm, bem como, compreender e analisar quais os principais fatores que estão inerentes a um projeto de Fontes de Energia Renovável, nomeadamente, na análise do Levelized Cost Of Electricity (LCOE) e paridade com a rede elétrica. Deste modo, pretende-se uma reanálise do ponto de vista económico de projetos com origem em fontes de energia renovável

Humusstabilität in urbanen Unterböden – Konsequenzen für deren Umlagerung

Große Mengen von humosem Bodenmaterial fallen bei Erdbaumaßnahmen an, die beim Deponieren oder Wiedereinbau Schäden durch die Freisetzung klimarelevanter Gase bewirken können. Deshalb ist die Frage zum Umgang mit Unterböden über 1 % TOC nach dessen unterschiedlicher Labilität zu klären. Dazu ergab eine Literaturrecherche, dass nicht die strukturbedingte Oxidierbarkeit bei 400°C primär die Beständigkeit TOC im Unterboden bestimmt, sondern das ökosystemar gesteuerte Bodenmilieu. Dies spiegelte sich auch wider in den nur vereinzelt erkennbaren Beziehungen zwischen den TOC400 – Werten eines bundesweiten Probenkollektivs, die mit dem „Gradientenverfahren“ nach DIN-Entwurf 19539 bestimmt wurden, und Parametern, die Hinweise auf die TOC-Stabilität in Unterböden geben könnten. Darüber hinaus ergab eine Befragung, dass die Akzeptanz von Maßnahmen des vorsorgenden Bodenschutzes, zu der auch das Verbringen von humosem Unterbodenmaterial zählt, zu ca. 50 % gegeben ist. Ob an Stelle der Prozentangabe eine TOC - Bagatellmenge fachgerecht und praktikabel umsetzbar sein könnte, wird abschießend diskutiert. Zum Prüfen dieses Vorschlags sind noch praxisnahe Szenarien zu untersuchen