Genetic evidence for the presence of two distinct hantaviruses associated with Apodemus mice in Croatia and analysis of local strains

In Europe, Dobrava-Belgrade (DOBV), Saaremaa (SAAV), and Puumala (PUUV) viruses are known to cause hemorrhagic fever with renal syndrome (HFRS). All three hantaviruses are now found in Croatia. Lung tissue samples of 315 Apodemus mice trapped in 2003-2004 were screened for the presence of hantaviral N-Ag and 20 mice (6.3%) were found either strongly positive or weak/suspected-positive. Partial sequences of hantavirus M and S segments were recovered by RT-PCR from six mice and subjected to (phylo)genetic analysis that revealed the presence of four novel strains of DOBV and one of SAAV. Curiously, one of the newly described DOBV strains was found in Apodemus agrarius mouse, that is, not in the traditional host, A. flavicollis mice, suggesting a spillover event. S segment sequences recovered previously from HFRS cases [Markoti? et al., 2002] were confirmed as DOBV sequences; one of which appeared particularly close to the prototype Slovenian DOBV isolate. Taken together with earlier data on PUUV in Croatia, these results show a co-circulation of three European hantavirus pathogens in this country. So far, not a single SAAV sequence has been recovered from HFRS patients either in Croatia or neighboring Slovenia and Hungary nor in Slovakia suggesting a somewhat lower fequency of acute SAAV infection in humans in this part of Europe than for example in the Baltics.     

Characterization of the H5N1 influenza virus isolated during an outbreak among wild birds in Russia (Tuva Republic) in 2010

A study of the basic biological properties of H5N1 subtype strain isolated during an outbreak among wild birds in Russia in 2010 is presented. The study was carried out using conventional methods according to the WHO recommendations. H5N1 influenza virus isolated in Siberia belonged to clade 2.3.2 of the hemagglutinin gene, and phylogenetic analysis was performed. The antigenic characteristics and the basic genetic markers of biological properties were studied. It was shown that all strains were highly pathogenic for chickens and white mice. Thus, it was shown that, in Russia, the 2010 H5N1 virus phylogenetically closely related to Asian variants caused epizootic among wild birds. The potential danger of this variant of the virus for humans was confirmed by different methods. We discussed the possibility of formulating the natural focus of H5N1 influenza.     

Propagating waves of self-assembly in organosilane monolayers

Wavefronts associated with reaction-diffusion and self-assembly processes are ubiquitous in the natural world. For example, propagating fronts arise in crystallization and diverse other thermodynamic ordering processes, in polymerization fronts involved in cell movement and division, as well as in the competitive social interactions and population dynamics of animals at much larger scales. Although it is often claimed that self-sustaining or autocatalytic front propagation is well described by mean-field "reaction-diffusion" or "phase field" ordering models, it has recently become appreciated from simulations and theoretical arguments that fluctuation effects in lower spatial dimensions can lead to appreciable deviations from the classical mean-field theory (MFT) of this type of front propagation. The present work explores these fluctuation effects in a real physical system. In particular, we consider a high-resolution near-edge x-ray absorption fine structure spectroscopy (NEXAFS) study of the spontaneous frontal self-assembly of organosilane (OS) molecules into self-assembled monolayer (SAM) surface-energy gradients on oxidized silicon wafers. We find that these layers organize from the wafer edge as propagating wavefronts having well defined velocities. In accordance with two-dimensional simulations of this type of front propagation that take fluctuation effects into account, we find that the interfacial widths w(t) of these SAM self-assembly fronts exhibit a power-law broadening in time, w(t) approximately t(beta), rather than the constant width predicted by MFT. Moreover, the observed exponent values accord rather well with previous simulation and theoretical estimates. These observations have significant implications for diverse types of ordering fronts that occur under confinement conditions in biological or materials-processing contexts.     

TRPpathies

Many human diseases are caused by mutations in ion channels. Dissecting the pathogenesis of these 'channelopathies' has yielded important insights into the regulation of vital biological processes by ions and has become a productive tool of modern ion channel biology. One of the best examples of a synergism between the clinical and basic science aspects of a modern biological topic is cystic fibrosis. Not only did the identification of the ion channel mutated in cystic fibrosis pinpoint the root cause of this disease, but it also has significantly advanced our understanding of basic biological processes as diverse as protein folding and epithelial fluid and electrolyte secretion. The list of confirmed 'channelopathies' is growing and several members of the TRP family of ion channels have been implicated in human diseases such as mucolipidosis type IV (MLIV), autosomal dominant polycystic kidney disease (ADPKD), familial focal segmental glomerulosclerosis (FSG), hypomagnesemia with secondary hypocalcaemia (HSH), and several forms of cancer. Analysing pathogenesis of the diseases linked to TRP dysregulation provides an exciting means of identifying novel functions of TRP channels.     

Noninvasive blood glucose monitoring with optical coherence tomography: a pilot study in human subjects

OBJECTIVE: To study the feasibility of noninvasive blood glucose monitoring using optical coherence tomography (OCT) technique in healthy volunteers. RESEARCH DESIGN AND METHODS: An OCT system with the wavelength of 1,300 nm was used in 15 healthy subjects in 18 clinical experiments. Standard oral glucose tolerance tests were performed to induce changes in blood glucose concentration. Blood samples were taken from the right arm vein every 5 or 15 min. OCT images were taken every 10-20 s from the left forearm over a total period of 3 h. The slope of the signals was calculated at the depth of 200-600 micro m from the skin surface. RESULTS: A total of 426 blood samples and 8,437 OCT images and signals were collected and analyzed in these experiments. There was a good correlation between changes in the slope of noninvasively measured OCT signals and blood glucose concentrations throughout the duration of the experiments. The slope of OCT signals changed significantly (up to 2.8% per 10 mg/dl) with variation of plasma glucose values. The good correlation obtained between the OCT signal slope and blood glucose concentration is due to the coherent detection of backscattered photons, which allows measurements of OCT signal from a specific tissue layer without unwanted signal from other tissue layers. CONCLUSIONS: This pilot study demonstrated the capability of the OCT technique to monitor blood glucose concentration noninvasively in human subjects. Further studies with a larger number of subjects including diabetic subjects are planned to validate these preliminary results.     

An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts

Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social–ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social–ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social–ecological models.In recent decades, the world’s biological and physical systems have experienced dramatic change (1, 2). Many marine ecosystems, for example, have undergone abrupt changes known as regime shifts (3, 4). In one prominent case, the Baltic cod fishery suddenly changed in the 1980s from historically high cod biomass and catches (henceforth the “cod boom”) to a sprat-dominant ecosystem with low cod abundance (5–8). This collapse, generally understood to have been precipitated by deteriorating environmental conditions and overfishing (7), had substantial negative socioeconomic impact on Baltic Sea fisheries, including among others the small-scale coastal fishery (9).Ecological analyses of regime shifts, such as of the Baltic cod fishery (10), can capture the complex interplay of ecological and physical processes and drivers that trigger the shift. Numerous studies, however, have shown that understanding individual and collective human behavior is also critical for managing natural resources (11, 12) such as marine ecosystems (13, 14). Social–ecological system research responds to the need to incorporate humans as part of ecosystems by treating natural resource use as arising from linked systems of humans and nature, so-called social–ecological systems. Social–ecological system dynamics result from feedback loops involving biophysical processes, human behavior, and institutional processes within given social and biophysical contexts (15). Formal, quantitative analyses of the contributions of the social and biophysical subsystems to a social–ecological system’s dynamics are rare, however, because knowledge of social–ecological systems is often partial and spread over multiple disciplines (16).Here, we tested the influence of social dynamics on a regime shift in a marine ecosystem using a formal modeling framework. Specifically, we investigated the significance of fisher decision making, as influenced by psychological, economic, and regulatory factors, on the 1980s boom and collapse of the Eastern Baltic cod stock. In a significant advance for natural resource modeling, and for social–ecological modeling more generally, use of the generalized modeling approach (17, 18) enabled us to empirically parameterize, dynamically model, and analyze the qualitative social and ecological dynamics of the Baltic cod fishery at comparable levels of detail and without detailed specification of causal relationships. The Baltic cod fishery was selected because the ecological dynamics during the cod boom and collapse have been well-studied (10, 19, 20), and information about fisher behavior and institutional settings, such as regulation and subsidy policy, is available. Additionally, the cod boom and collapse are qualitatively distinct features of the social–ecological system’s dynamics that are amenable to the concepts and methods of dynamical systems theory (21), such as stability.