Direct observation of membrane insertion by enveloped virus matrix proteins by phosphate displacement

Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking. We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families. This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes.

How the magnetopause transition parameter works

The transition parameter is based on the electron characteristics close to the Earth's dayside magnetopause, but reveals systematic ordering of other, independent, data such as the ion flow, density and temperature and the rientation and strength of the magnetic field. Potentially, therefore, it is a very useful tool for resolving ambiguities in a sequence of satellite data caused by the effects of structure and motion of the boundary; however, its application has been limited because there has been no clear understanding of how it works. We present an analysis of data from the AMPTE-UKS satellite which shows that the transition parameter orders magnetopause data because magnetic reconnection generates newly-opened field lines which coat the boundary: a direct relationship is found with the time elapsed since the boundary-layer field line was opened. A simple model is used to reproduce this behaviour.

Roger Machado, Perkin Warbeck and heraldic espionage

An examination of the medieval herald's role in international espionage. It is argued that heralds were used as spies, despite their creation oaths stipulating that their job should not encompass this task. The herald Roger Machado's involvement in the diplomacy surrounding the pretender to the English throne, Perkin Warbeck, is scrutinized and is offered as evidence that Machado did act as a spy for Henry VII on the international stage.

Bio-fabrication and physiological self-release of tissue equivalents using smart peptide amphiphile templates

In this study we applied a smart biomaterial formed from a self-assembling, multi-functional synthetic peptide amphiphile (PA) to coat substrates with various surface chemistries. The combination of PA coating and alignment-inducing functionalised substrates provided a template to instruct human corneal stromal fibroblasts to adhere, become aligned and then bio-fabricate a highlyordered, multi-layered, three-dimensional tissue by depositing an aligned, native-like extracellular matrix. The newly-formed corneal tissue equivalent was subsequently able to eliminate the adhesive properties of the template and govern its own complete release via the action of endogenous proteases. Tissues recovered through this method were structurally stable, easily handled, and carrier-free. Furthermore, topographical and mechanical analysis by atomic force microscopy showed that tissue equivalents formed on the alignment-inducing PA template had highly-ordered, compact collagen deposition, with a two-fold higher elastic modulus compared to the less compact tissues produced on the non-alignment template, the PA-coated glass. We suggest that this technology represents a new paradigm in tissue engineering and regenerative medicine, whereby all processes for the biofabrication and subsequent self-release of natural, bioprosthetic human tissues depend solely on simple templatetissue feedback interactions.

Amor intellectualis diaboli

An essay on love and liberty in the writings of Gillian Rose, Marquis de Sade, Max Horkheimer and Theodor W. Adorno, written in response to the following provocation: "Encore un effort. A banderole publicitaire carries the breathless descriptions of the new fashions for 1968, when anything goes and details place the accent on this or that part of the body and its adornment: a pair of shoes that come off in a struggle, for example, the heel of one snapped off; a striking checked shirt, with two buttons undone; a light-coloured trench coat (perfect for a May day); a blouson-style jacket that allows easy freedom of movement; place casual slacks worn with an ankle boot. Beauty is in the streets as fashion becomes democratic (or so say the houses of haute couture), while the philosopher of the boudoir extorts us once again to make an effort if we wish to be republicans. Here, to an assembled crowd of sensitive men and women, which petit-maitre or dangerous man of principles would suggest that the only moral system to reinforce political revolution is that of libertinage, the revenge of nature's course against the aberrations of society?"

Erythristic leopards Panthera pardus in South Africa

Background. Leopards Panthera pardus show genetically determined colour variation. Erythristic (strawberry) morphs, where individuals are paler and black pigment in the coat is replaced by a red-brown colour, are exceptionally rare in the wild. Historically, few records exist, with only five putative records from India known. Objectives. To record the presence of erythristic leopards in our study site (Thabo Thalo Wilderness Reserve, Mpumalanga), and to collate records from across South Africa. Method. A network of camera traps was used to record individual leopards at Thabo Thalo. We also surveyed local experts, searched the popular South African press and used social media to request observations. Results. Two out of 27 individual leopards (7.1%) recorded in our study site over three years were of this colour morph. We obtained records of five other erythristic leopards in the Waterberg and Mpumalanga region, with no reports outside of this population. Conclusions. Erythristic leopards are widely dispersed across north-west South Africa, predominantly in the Lydenburg region. The presence of this rare colour morph may reflect the consequences of population fragmentation.

Wheat seed embryo excision enables the creation of axenic seedlings and Koch’s postulates testing of putative bacterial endophytes

Early establishment of endophytes can play a role in pathogen suppression and improve seedling development. One route for establishment of endophytes in seedlings is transmission of bacteria from the parent plant to the seedling via the seed. In wheat seeds, it is not clear whether this transmission route exists, and the identities and location of bacteria within wheat seeds are unknown. We identified bacteria in the wheat (Triticum aestivum) cv. Hereward seed environment using embryo excision to determine the location of the bacterial load. Axenic wheat seedlings obtained with this method were subsequently used to screen a putative endophyte bacterial isolate library for endophytic competency. This absence of bacteria recovered from seeds indicated low bacterial abundance and/or the presence of inhibitors. Diversity of readily culturable bacteria in seeds was low with 8 genera identified, dominated by Erwinia and Paenibacillus. We propose that anatomical restrictions in wheat limit embryo associated vertical transmission, and that bacterial load is carried in the seed coat, crease tissue and endosperm. This finding facilitates the creation of axenic wheat plants to test competency of putative endophytes and also provides a platform for endophyte competition, plant growth, and gene expression studies without an indigenous bacterial background.

Anatomical and biochemical changes in the composition of developing seed coats of annatto (Bixa orellana L.)

Seeds of Bixa orellana (L.) have a sclerified palisade cell layer, which constitutes a natural barrier to water uptake. In fact, newly fully developed B. orellana seeds are highly impermeable to water and thereby dormant. The purpose of this work is to investigate, from a developmental point of view, the histochemical and physical changes in the cell walls of the seed coat that are associated with the water impermeability. Seed coat samples were analyzed by histochemical and polarization microscopy techniques, as well as by fractionation/HPAEC-PAD. For histochemical analysis the tissue samples were fixed, dehydrated, embedded in paraffin and the slides were dewaxed and tested with appropriate stains for different cell wall components. Throughout the development of B. orellana seeds, there was a gradual thickening of the seed coat at the palisade region. This thickening was due to the deposition of cellulose and hemicelluloses in the palisade layer cell walls, which resulted in a highly water impermeable seed coat. The carbohydrate composition of the cell walls changed dramatically at the late developmental stages due to the intense deposition of hemicelluloses. Hemicelluloses were mainly deposited in the outer region of the palisade layer cell walls and altered the birefringent pattern of the walls. Xylans were by far the most abundant hemicellulosic component of the cell walls. Deposition of cellulose and hemicelluloses, especially xylans, could be responsible for the impermeability to water observed in fully developed B. orellana seeds.

Efficiency of uniparental male and female care against egg predators in two closely related syntopic harvestmen

Although the benefits of maternal care have been investigated in many species, the caring role of males in species with exclusive paternal care has received less attention. We experimentally quantified the protective role of paternal care in the harvestman Iporangaia pustulosa. Additionally, we compared the effectiveness of paternal care against predation in this species with a syntopic harvestman with maternal care, Acutisoma proximum. We demonstrated that nearly one-third of the unprotected Iporangaia clutches disappeared entirely in 12 days, while the other two-thirds suffered a mean reduction of 55% in egg number. Conversely, 50% of the control clutches did not suffer any reduction, and only one was entirely consumed by predators. We also demonstrated that the mucus coat that covers Iporangaia clutches has an important deterrent role against predation by conspecifics: 58.3% of the clutches without mucus were attacked and three of them were entirely consumed, whereas only three clutches with mucus were attacked, suffering a reduction of up to three eggs. Iporangaia males were as efficient as Acutisoma females in protecting eggs. However, unattended Acutisoma eggs were attacked 20% more frequently than unattended Iporangaia eggs. Unattended Iporangaia eggs are protected by a mucus coat that prevents or decreases predation rate, whereas Acutisoma eggs are more susceptible to predation, probably because they lack this mucus coat. Thus, besides the fact that Iporangaia males efficiently protect the offspring against egg predators, females also contribute to egg protection by providing a mucus coat that deters egg predators. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

On spermiogenesis, sperm cell morphology and accompanying secretions of Copidognathus (Acari: Halacaridae)

The genus Copidognathus includes one-third of the species of Halacaridae described to date. This article describes spermiogenesis, sperm cell morphology and accompanying secretions from three species of Copidognathus. Initial spermatids have electron-dense cytoplasm with scattered mitochondria, a well-developed Golgi body, and nuclei with patches of heterochromatin. The cytoplasm and nuclei of these cells undergo intense swelling. The second spermatids are large electron-translucent cells, with small mitochondria in row along the remains of the endoplasmatic reticulum. In the succeeding stage, most of the cytoplasmatic structures and mitochondria have disappeared or have undergone profound transformations. Nuclei and cells elongate and chromatin begins to condense near the nuclear envelope. An acrosomal complex appears at the tip of the nucleus. The acrosomal filament is thick and runs the entire length of the nucleus. Plasmalemmal invaginations at the cell surface give rise to tubules filled with an electron-dense material. Sperm cell maturation is completed in the ventral portion of the germinal part, near the testicular lumen. As a final step in spermiogenesis, cytoplasm of the last spermatid undergoes a moderate condensation and the cariotheca disappears. Mature sperm cells were found in a matrix of ""simple"" and ""complex"" corpuscles, the latter consisting of flattened, spindle-shaped secreted bodies. Rather than in individual sperm aggregates, spermatozoa were contained in a single droplet inside the vas deferens, on a large secretion mass, structured as rows of platelets sunk in a fine grained matrix. Each mature sperm cell is covered by a thick secreted coat. In contrast to the genera Rhombognathus and other Actinotrichida, Copidognathus displays a set of features that must be regarded as apomorphic. The absence of usual mitochondria, the presence of electro-dense tubules and secretions similar to those present in Thalassarachna and Halacarellus, and the pattern of nuclear condensation are possibly shared apomorphies with these latter genera. (C) 2010 Elsevier GmbH. All rights reserved.

Infection by Trypanosoma vivax in goats and sheep in the Brazilian semiarid region: From acute disease outbreak to chronic cryptic infection

A study was undertaken to investigate the role of Trypanosoma vivax in sheep and goat mortality and abortions in the Brazilian semiarid region, where outbreaks Had been previously reported in bovines. For this purpose, 177 goats and 248 sheep (20% of herds) were randomly sampled on four farms in the State of Paraiba in May and October 2008. The animals were screened for trypanosomes by the buffy coat technique (BCT) and PCR. Infected animals, similar to 25% in both surveys, manifested apathy, pale mucous membranes, enlarged lymph nodes, weakness, weight loss, opacity of the cornea, blindness and abortion. However, the animals with acute and severe disease showing the highest levels of parasitemia and fever, which many times resulted in death, were only detected in the first survey. These severely diseased animals exhibited progressive weight loss and had the smallest packed cell volume (PCV) values. During survey 2, done in October 2008 on the same farms, only animals with low parasitemia and normal temperatures, PCV values and body weights were detected. Therefore, animals that spontaneously recovered from acute infection developed chronic and asymptomatic disease. This finding demonstrated for the first time that sheep and goats, which are the most important livestock in the semiarid region of Brazil, may be severely injured by T. vivax infection and also play a role as asymptomatic carriers and important sources of T. vivax to ruminants in general. Published by Elsevier B.V.

Coating of Cotton Yarn with Poly(vinyl alcohol) and Poly(N-vinyl-2-pyrrolidone) Crosslinked via Ultraviolet Radiation

The coating of cotton fiber is used in the textile industry to increase the mechanical resistance of the yarn and their resistance to vibration, friction, impact, and elongation, which are some of the forces to which the yarn is subjected during the weaving process. The main objective of this study was to investigate the use of synthetic hydrophilic polymers, poly(vinyl alcohol) (PVA), and poly(N-vinyl-2-pyrrolidone) (PVP) to coat 100% cotton textile fiber, with the aim of giving the fiber temporary mechanical resistance. For the fixation of the polymer on the fiber, UV-C radiation was used as the crosslinking process. The influence of the crosslinking process was determined through tensile testing of the coated fibers. The results indicated that UV-C radiation increased the mechanical resistance of the yarn coated with PVP by up to 44% and the yarn coated with PVA by up to 67% compared with the pure cotton yarn, that is, without polymeric coating and crosslinking. This study is of great relevance, and it is important to consider that UV-C radiation dispenses with the use of chemical substances and prevents the generation of toxic waste at the end of the process. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2560-2567, 2011

Crosslinking of Poly(N-vinyl-2-pyrrolidone) in the Coating of Cotton Yarn

Coating of cotton yarn is employed in the textile industry to increase the mechanical resistance of the yarns and resistance to vibration, friction, impact, and elongation, which are some of the forces to which the yarn is subjected during the weaving process. The main objective of this study is to investigate the usage of a synthetic hydrophilic polymer, poly(N-vinyl-2-pyrrolidone) (PVP), to coat 100% cotton textile yarn, aiming to give the yarn a temporary mechanical resistance. For the improvement of the mechanical resistance of the yarn, the following crosslinking processes of PVP were investigated: UV-C (ultraviolet) radiation, the Fenton and photo-Fenton reactions, and sensitized UV-C radiation. The influence of each crosslinking process was determined through tensile testing of the coated yarns. The results indicated that the best crosslinking process employed was UV-C radiation; increasing the mechanical resistance of the yarn up to 44% if compared with the pure cotton yarn, that is, without polymeric coating and crosslinking. POLYM. ENG. SCI., 51:445-453, 2011. (C) 2010 Society of Plastics Engineers

Removal of metal ions from aqueous solution by chelating polymeric hydrogel

Polysaccharide natural seed coat from the tree Magonia pubescens, in the form of hydrogel was used to remove metals in aqueous solution. Swelling tests indicate that seed coat presents hydrogel behavior, with maximum water absorption of 292 g water/g. Adsorption experiments performed using Na(+), Mg(2+), K(+), Ca(2+), Cr(3+), Fe(3+) and Zn(2+) demonstrated that the polysaccharide structure has a high capacity to extract these ions from the aqueous solution. Scanning electron microscopy revealed significant morphological changes of the material before and after water contact. Differential scanning calorimetry measurements indicate a signal shift of the water evaporation temperature in the material with adsorbed zinc. X-ray photoelectron spectroscopy analysis combined with theoretical studies by the density functional theory and on Hartree-Fock (HF) level evidence that the metallic ions were adsorbed through coordination with hydroxyl groups of polysaccharide. In the case of Zn(2+) the lowest HF energy was observed for the tetracoordination mode, where Zn(2+) is coordinated by two hydroxyl groups and two water molecules.

Utredning om huruvida Dalarnas Tidningars produktion passar en KBA Cortina

This degree project illustrates newsprint and waterless offset. A new news press was introduced at Drupa-00, Cortina from KBA, which is the first news press dedicated the waterless technique. With actual statistics from the company in question an investigation was made whether their production fits this press. It came out in the investigation that the production of the company, from statistics, fits this press very good. A table was made where different timeschedules were accounted for the new press, with semi- and full automatic plate changing for present and to be added papers. The waterless technology is compared to conventional offset with the difference that the plate is based on a sort of laminatetechnology. Like conventional plates this plate has a base made of aluminium. Lightsensitive photopolymer isunited as a layer or coat on top of the aluminium and a 2µm thin oleophobic siliconlayer is applied on top of the photopolymer. Considering the print, the waterless method has a higher qualitygrade than conventional offset. No water is emulsifiedin the ink, and therefore the printed dot gets a higher density. The loss of dampening solution and higher tack of the ink gives sharper dots. This makes the colourspace bigger why a greater range of colours can be printed. The loss of dampening solution gives a more stable dotgain, which contributes to that a higher screen can be used. The disadvantage is that the plate can't do as many rotations as the conventional plate. A waterless plate makes around 100 000-500 000 rotations before it needs to be removed owing to type- and manufacturer of the plate. The plate is also slightly more sensitive and expensive than conventional plates, around 1,4 - 1,7 × aluminium printing plates. A waterless system can be installed in a conventional printing press by degrees and when large editions are being printed a cooler needs to be installed in the oscillationrollers of the press, since an increase in temperature can make the oleophobic parts of the plate oleophilic. The Cortina is however equipped with a temperature controlsystem at the beginning. To avoid picking, caused by the tacky ink, a blanket with a high “quick release” should be used.