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An automatic, centimetre-level accuracy mapping system was developed and evaluated for precision real-time geospatial mapping of transplanted tomato plants. The system utilised a single Real-time Kinematic-Global Positioning System (RTK-GPS) system mounted on the tractor for Global Positioning System (GPS) location mapping of planting events occurring on the tractor-drawn transplanter. The mechanical hitch interface between the tractor and the transplanter was instrumented with orientation sensors to allow computation of the GPS crop plant location without the need for an independent RTK-GPS system located on the transplanter thereby reducing the equipment cost of the system. A ruggedised, real-time, embedded controller was used for sensor monitoring and logging of GPS location, planting events and transplanter odometry data. The system was capable of producing highly accurate maps of crop plant location for subsequent precision plant care tasks conducted at the centimetre scale. The benefit of the tractor-based RTK-GPS system for geospatial mapping of transplants such as tomato demonstrated in this work is that it enables farmers with existing RTK-GPS tractor-mounted auto guidance systems to better utilise their existing GPS technology by allowing them to automatically create centimetre-accuracy plant maps for subsequent precision plant specific treatment systems. Such systems could provide substantial savings in agro-chemicals with associated environmental and economic advantages for sustainable agricultural production systems. [Copyright &y& Elsevier]

Abstract: Increased serotonergic activity is often described as increasing the inhibition of behaviors. This study examined the more general hypothesis that increased serotonergic activity produces greater control over social behavior. Participants were drawn from two samples, individuals elevated on irritability and individuals unselected on personality characteristics. Individuals participated in a double blind cross-over design, providing event contingent records about their behavior during two 9-day periods which involved taking tryptophan or placebo. When taking tryptophan (which increases serotonergic activity), within-person variability among social behaviors across events (i.e., interpersonal spin) was reduced for irritable individuals, particularly those low on trait Agreeableness. These results suggest that higher levels of serotonergic activity enhance greater control and consistency in social behavior among irritable–disagreeable individuals. [Copyright &y& Elsevier]

Abstract: Colloidal phenomena play an important role in natural porous media, where they influence soil structuring, contaminant migration, filtration, and clogging. Several methods are available to measure pore space geometry within porous media, but these methods have limited applicability when the relevant physical, chemical, or biological processes are dominated by dynamic colloidal phenomena. Here we report a new technique to quantify colloid aggregate structure as a fractal dimension using static light scattering within index-matched porous media (granular Nafion). We validate the method by obtaining consistent results for scattering in suspensions and in porous media, and verify that multiple scattering at environmentally relevant colloid concentrations does not affect the determination of fractal dimension. We also observe restructuring of aggregates during homogenization in the porous media, indicated by an apparent increase in fractal dimension, which can be explained by an analysis of the fluid shear stress caused by repeated inversions of test tubes either containing or not containing granular media. This technique will permit progress in obtaining fundamental descriptions of colloidal phenomena in porous media. [Copyright &y& Elsevier]

Abstract: Clostridium perfringens enterotoxin (CPE) is a major cause of food poisoning and antibiotic-associated diarrhea. Upon its release from C. perfringens spores, CPE binds to its receptor, claudin, at the tight junctions between the epithelial cells of the gut wall and subsequently forms pores in the cell membranes. A number of different complexes between CPE and claudin have been observed, and the process of pore formation has not been fully elucidated. We have determined the three-dimensional structure of the soluble form of CPE in two crystal forms by X-ray crystallography, to a resolution of 2.7 and 4.0 Å, respectively, and found that the N-terminal domain shows structural homology with the aerolysin-like β-pore-forming family of proteins. We show that CPE forms a trimer in both crystal forms and that this trimer is likely to be biologically relevant but is not the active pore form. We use these data to discuss models of pore formation. [Copyright &y& Elsevier]

Abstract: To provide the three-way comparisons needed to test existing theories, we compared (1) most-stressful memories to other memories and (2) involuntary to voluntary memories (3) in 75 community dwelling adults with and 42 without a current diagnosis of posttraumatic stress disorder (PTSD). Each rated their three most-stressful, three most-positive, seven most-important and 15 word-cued autobiographical memories, and completed tests of personality and mood. Involuntary memories were then recorded and rated as they occurred for 2weeks. Standard mechanisms of cognition and affect applied to extreme events accounted for the properties of stressful memories. Involuntary memories had greater emotional intensity than voluntary memories, but were not more frequently related to traumatic events. The emotional intensity, rehearsal, and centrality to the life story of both voluntary and involuntary memories, rather than incoherence of voluntary traumatic memories and enhanced availability of involuntary traumatic memories, were the properties of autobiographical memories associated with PTSD. [Copyright &y& Elsevier]

Abstract: Participants with posttraumatic stress disorder (PTSD) and participants with a trauma but without PTSD wrote narratives of their trauma and, for comparison, of the most-important and the happiest events that occurred within a year of their trauma. They then rated these three events on coherence. Based on participants’ self-ratings and on naïve-observer scorings of the participants’ narratives, memories of traumas were not more incoherent than the comparison memories in participants in general or in participants with PTSD. This study comprehensively assesses narrative coherence using a full two (PTSD or not) by two (traumatic event or not) design. The results are counter to most prevalent theoretical views of memory for trauma. [Copyright &y& Elsevier]

Abstract: When recalling autobiographical memories, individuals often experience visual images associated with the event. These images can be constructed from two different perspectives: first person, in which the event is visualized from the viewpoint experienced at encoding, or third person, in which the event is visualized from an external vantage point. Using a novel technique to measure visual perspective, we examined where the external vantage point is situated in third-person images. Individuals in two studies were asked to recall either 10 or 15 events from their lives and describe the perspectives they experienced. Wide variation in spatial locations was observed within third-person perspectives, with the location of these perspectives relating to the event being recalled. Results suggest remembering from an external viewpoint may be more common than previous studies have demonstrated. [Copyright &y& Elsevier]

Abstract: To better understand the adaptive significance of adrenal glucocorticoid (GC) variation in the giant panda, we assessed patterns of fecal GC excretion over time as well as during estrus, parturient and non-parturient luteal phases, lactation and acyclicity in 17 adult females. Fecal estrogen and GC patterns were positively correlated (P <0.05) in four of five periestrual females (r =0.57–0.92). Among all reproductive states, fecal GC was highest (P <0.05) during periestrus (non-parturient, 495.9±100.7ng/g [mean±SE]; parturient, 654.1±106.5ng/g; P >0.05). Concentrations of GC metabolites were lower (P <0.05) during the later stage of the luteal phase in non-parturient (334.8±24.8ng/g) compared to parturient (470.4±54.0ng/g) females. Although fecal GC concentrations in cyclic, non-parturient females did not differ (P >0.05) across all seasons, there were seasonal variations (P <0.05) in females that were acyclic and non-lactational. However, the overall lack of difference (P >0.05) in GC values between reproductively cyclic and acyclic females did not support the hypothesis that ovarian acyclicity is due to increased adrenal activity (related or unrelated to physiological stress). Furthermore, GCs may play an important role in the normal endocrine milieu associated with sexual receptivity and late pregnancy. These data demonstrate that both reproductive status and seasonal factors are important modulators of adrenal function in this endangered species. [Copyright &y& Elsevier]

Abstract: Transcranial direct current stimulation (tDCS) can up- and down-regulate cortical excitability depending on current direction, however our abilities to measure brain-tissue effects of the stimulation and its after-effects have been limited so far. We used regional cerebral blood flow (rCBF), a surrogate measure of brain activity, to examine regional brain-tissue and brain-network effects during and after tDCS. We varied the polarity (anodal and cathodal) as well as the current strength (0.8 to 2.0mA) of the stimulation. Fourteen healthy subjects were randomized into receiving either anodal or cathodal stimulation (two subjects received both, one week apart) while undergoing Arterial Spin Labeling (ASL) in the MRI scanner with an alternating off–on sampling paradigm. The stimulating, MRI-compatible electrode was placed over the right motor region and the reference electrode over the contralateral supra-orbital region. SPM5 was used to process and extract the rCBF data using a 10mm spherical volume of interest (VOI) placed in the motor cortex directly underneath the stimulating scalp electrode. Anodal stimulation induced a large increase (17.1%) in rCBF during stimulation, which returned to baseline after the current was turned off, but exhibited an increase in rCBF again in the post-stimulation period. Cathodal stimulation induced a smaller increase (5.6%) during stimulation, a significant decrease compared to baseline (−6.5%) after cessation, and a continued decrease in the post-stimulation period. These changes in rCBF were all significant when compared to the pre-stimulation baseline or to a control region. Furthermore, for anodal stimulation, there was a significant correlation between current strength and the increase in rCBF in the on-period relative to the pre-stimulation baseline. The differential rCBF after-effects of anodal (increase in resting state rCBF) and cathodal (decrease in resting state rCBF) tDCS support findings of behavioral and cognitive after-effects after cathodal and anodal tDCS. We also show that tDCS not only modulates activity in the brain region directly underlying the stimulating electrode but also in a network of brain regions that are functionally related to the stimulated area. Our results indicate that ASL may be an excellent tool to investigate the effects of tDCS and its stimulation parameters on brain activity. [Copyright &y& Elsevier]

Abstract: Hsp40-like co-chaperones are ubiquitous enzymes that stimulate the protein refolding activity of Hsp70 family chaperones. They are widespread in prokaryotic and eukaryotic systems. In bacteria, the best characterized co-chaperone is the Escherichia coli DnaJ protein. Many γ-proteobacteria encode a functional homologue of DnaJ, known as CbpA, which is expressed in response to starvation and environmental stress. The activity of CbpA is regulated by the “modulator” protein CbpM. Here, we have used a combination of genetics and biochemistry to identify the co-chaperone contact determinant of CbpM. We show that the nature of the interaction is conserved in enterobacteria. [Copyright &y& Elsevier]

Abstract: The Vlasov–Poisson equations describe the evolution of a collisionless plasma, represented through a probability density function (PDF) that self-interacts via an electrostatic force. One of the main difficulties in numerically solving this system is the severe time-step restriction that arises from parts of the PDF associated with moderate-to-large velocities. The dominant approach in the plasma physics community for removing these time-step restrictions is the so-called particle-in-cell (PIC) method, which discretizes the distribution function into a set of macro-particles, while the electric field is represented on a mesh. Several alternatives to this approach exist, including fully Lagrangian, fully Eulerian, and so-called semi-Lagrangian methods. The focus of this work is the semi-Lagrangian approach, which begins with a grid-based Eulerian representation of both the PDF and the electric field, then evolves the PDF via Lagrangian dynamics, and finally projects this evolved field back onto the original Eulerian mesh. In particular, we develop in this work a method that discretizes the 1+1 Vlasov–Poisson system via a high-order discontinuous Galerkin (DG) method in phase space, and an operator split, semi-Lagrangian method in time. Second-order accuracy in time is relatively easy to achieve via Strang operator splitting. With additional work, using higher-order splitting and a higher-order method of characteristics, we also demonstrate how to push this scheme to fourth-order accuracy in time. We show how to resolve all of the Lagrangian dynamics in such a way that mass is exactly conserved, positivity is maintained, and high-order accuracy is achieved. The Poisson equation is solved to high-order via the smallest stencil local discontinuous Galerkin (LDG) approach. We test the proposed scheme on several standard test cases. [Copyright &y& Elsevier]

Abstract: αS-Casein, the major milk protein, comprises αS1- and αS2-casein and acts as a molecular chaperone, stabilizing an array of stressed target proteins against precipitation. Here, we report that αS-casein acts in a similar manner to the unrelated small heat-shock proteins (sHsps) and clusterin in that it does not preserve the activity of stressed target enzymes. However, in contrast to sHsps and clusterin, α-casein does not bind target proteins in a state that facilitates refolding by Hsp70. αS-Casein was also separated into α- and α-casein, and the chaperone abilities of each of these proteins were assessed with amorphously aggregating and fibril-forming target proteins. Under reduction stress, all α-casein species exhibited similar chaperone ability, whereas under heat stress, α-casein was a poorer chaperone. Conversely, αS2-casein was less effective at preventing fibril formation by modified κ-casein, whereas α- and αS1-casein were comparably potent inhibitors. In the presence of added salt and heat stress, αS1-, α- and αS-casein were all significantly less effective. We conclude that αS1- and α-casein stabilise each other to facilitate optimal chaperone activity of αS-casein. This work highlights the interdependency of casein proteins for their structural stability. [Copyright &y& Elsevier]

Abstract: Scientific theories seek to provide simple explanations for significant empirical regularities based on fundamental physical and mechanistic constraints. Biological theories have rarely reached a level of generality and predictive power comparable to physical theories. This discrepancy is explained through a combination of frozen accidents, environmental heterogeneity, and widespread non-linearities observed in adaptive processes. At the same time, model building has proven to be very successful when it comes to explaining and predicting the behavior of particular biological systems. In this respect biology resembles alternative model-rich frameworks, such as economics and engineering. In this paper we explore the prospects for general theories in biology, and suggest that these take inspiration not only from physics, but also from the information sciences. Future theoretical biology is likely to represent a hybrid of parsimonious reasoning and algorithmic or rule-based explanation. An open question is whether these new frameworks will remain transparent to human reason. In this context, we discuss the role of machine learning in the early stages of scientific discovery. We argue that evolutionary history is not only a source of uncertainty, but also provides the basis, through conserved traits, for very general explanations for biological regularities, and the prospect of unified theories of life. [Copyright &y& Elsevier]

Abstract: Referential thinking is the tendency to view innocuous stimuli as having a specific meaning for the self and is associated with personality traits and disorders. In three studies, this research examined the relations among referential thinking, self-processing, and paranoia. In Study 1, follow-up questions on the Referential Thinking Scale () revealed that referential thoughts are experienced as unpleasant and pleasant. In Study 2, unpleasant referential thinking was more strongly associated with paranoia and maladaptive self-processing and personality. CFAs in Studies 1 and 2 found that unpleasant and pleasant referential thinking loaded on different factors. In Study 3, a group of participants with elevated schizotypal personality reported more unpleasant and pleasant referential thoughts than a control group. [Copyright &y& Elsevier]

Background: Unintentional injury is a leading cause of preventable mortality in elderly populations and is most often related to accidental falls and motor vehicle accidents. Hispanic ethnicity has been previously associated with decreased risk of accidental fall death as well as improved outcomes in other health states, the “Hispanic paradox.” A timely analysis of national data with consideration for multiple injury types and age could provide insight into this epidemiologic phenomenon and help guide the use of prevention efforts. Materials and Methods: Search of the Center for Disease Control''s WISQARS database was performed to identify the number of fatalities in the U.S. between 2003 and 2006 by age group, gender, Hispanic ethnicity, and injury type. Total U.S. population and group populations for the years examined were obtained from the U.S. Census Bureau''s American Community Survey for each year. Mortality was calculated as fatalities over the total group population for the years examined. Results: Independent of gender and age group, elderly Hispanics were at decreased risk of death from accidental fall or as an occupant in a motor vehicle accident, but increased risk of pedestrian fatality compared with white-NH. Conclusions: The reduced fall and occupant mortality seen in elderly Hispanic populations may come at the cost of increased pedestrian-related mortality. This is consistent with and likely reflects differences in culture, socioeconomic status, and geographic distribution for the U.S. Hispanic population. Effective targeting of injury prevention programs, especially community based, should consider the role of Hispanic ethnicity and its impact on lifestyle. [Copyright &y& Elsevier]

Abstract: Interleukin (IL) 15 is an inflammatory cytokine that plays an essential role in the activation, proliferation, and maintenance of specific natural killer cell and T-cell populations, and has been implicated as a mediator of inflammatory diseases. An anti-IL-15 antibody that blocked IL-15-dependent cellular responses was isolated by phage display and optimised via mutagenesis of the third complementarity-determining regions (CDRs) of variable heavy (VH) and variable light chains. Entire repertoires of improved variants were recombined with each other to explore the maximum potential sequence space. DISC0280, the most potent antibody isolated using this comprehensive strategy, exhibits a 228-fold increase in affinity and a striking 40,000-fold increase in cellular potency compared to its parent. Such a wholesale recombination strategy therefore represents a useful method for exploiting synergistic potency gains as part of future antibody engineering efforts. The crystal structure of DISC0280 Fab (fragment antigen binding), in complex with human IL-15, was determined in order to map the structural epitope and paratope. The most remarkable feature revealed lies within the paratope and is a novel six-amino-acid α-helix that sits within the VH CDR3 loop at the center of the antigen binding site. This is the first report to describe an α-helix as a principal component of a naturally derived VH CDR3 following affinity maturation. [Copyright &y& Elsevier]

A large body of social science literature has focused on the factors that influence sentencing outcomes within the federal court system. A neglected variable in this line of research is the citizenship status of the offender. Using the United States Sentencing Commission’s Monitoring of Federal Criminal Sentences data from 2006, the present study examines the effect of citizenship status on the likelihood of incarceration and the length of the prison sentence. This study extends previous research in three ways: first, by examining citizenship status using post-Booker data; second, exploring the differences between citizens, legal aliens, and illegal aliens rather than comparing all non-citizens to US citizens; and third, examining all offenses rather than only drug offenses. Most importantly, this study partitions the data by citizenship status to determine if the effects of race/ethnicity and other variables (e.g., type of offense and level of education) vary by citizenship status. The results demonstrate that both legal and illegal aliens have a higher probability of incarceration than similarly-situated US citizens, but that the sentences imposed on illegal aliens are shorter than those imposed on citizens. However, different results emerged when the data were partitioned by citizenship status. Judges imposed shorter prison sentences on Latino citizens, but longer prison sentences on Latino illegal aliens. These results are discussed in relation to theoretical explanations and policy implications. [Copyright &y& Elsevier]

Abstract: Adipose tissue inflammation in obesity is a major factor leading to cardiovascular disease and type 2 diabetes.12/15 lipoxygenases (ALOX) play an important role in the generation of inflammatory mediators, insulin resistance and downstream immune activation in animal models of obesity. However, the expression and roles of 12/15ALOX isoforms, and their cellular sources in human subcutaneous (sc) and omental (om) fat in obesity is unknown. The objective of this study was to examine the gene expression and localization of ALOX isoforms and relevant downstream cytokines in subcutaneous (sc) and omental (om) adipose tissue in obese humans. Paired biopsies of sc and om fat were obtained during bariatric surgeries from 24 morbidly obese patients. Gene and protein expression for ALOX15a, ALOX15b and ALOX 12 were measured by real-time PCR and western blotting in adipocytes and stromal vascular fractions (SVF) from om and sc adipose tissue along with the mRNA expression of the downstream cytokines IL-12a, IL-12b, IL-6, IFNγ and the chemokine CXCL10. In a paired analysis, all ALOX isoforms, IL-6, IL-12a and CXCL10 were significantly higher in om vs. sc fat. ALOX15a mRNA and protein expression was found exclusively in om fat. All of the ALOX isoforms were expressed solely in the SVF. Further fractionation of the SVF in CD34+ and CD34− cells indicated that ALOX15a is predominantly expressed in the CD34+ fraction including vascular and progenitor cells, while ALOX15B is mostly expressed in the CD34− cells containing various leucocytes and myeloid cells. This result was confirmed by immunohistochemistry showing exclusive localization of ALOX15a in the om fat and predominantly in the vasculature and non-adipocyte cells. Our finding is identifying selective expression of ALOX15a in human om but not sc fat. This is a study showing a major inflammatory gene exclusively expressed in visceral fat in humans. [Copyright &y& Elsevier]

Abstract: Analysis of serum hormones is useful for timing artificial insemination (Luteinizing hormone) and diagnosing pregnancy (prolactin) in elephants. However, these tests require blood collection, which is not tolerated by all animals, and is impractical for field studies. Thus, developing a means to obtain these measures noninvasively could improve species management. Matched urine and serum was collected from Asian and African elephants daily throughout the follicular phase and after administration of a GnRH analogue for LH determination, and in pregnant and nonpregnant females for prolactin analyses using immunoassays validated for elephant serum. Despite identifying robust increases in circulating hormone concentrations, no concomitant changes in urinary LH or prolactin immunoactivity was detected. Concentration of samples by centrifugal filtration or ethanol precipitation did not increase the ability to measure biologically relevant changes in endogenous urinary LH or prolactin immunoactivity. Sample matrix interference was ruled out following sufficient recovery of exogenous LH or prolactin added to samples, except for samples concentrated >35-fold where some interference was suspected. These results suggest that elephants either do not excrete native LH or prolactin in urine, or concentrations are too low to be measured accurately by standard immunoassay techniques that are valid for serum analyses. Thus, it does not appear feasible or economically viable to use these noninvasive tests for ovulation detection or for pregnancy diagnosis in elephants. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Based on considerable prospective data, risk-reducing salpingo-oophorectomy (RRSO) is one of the most beneficial interventions available to reduce ovarian/breast cancer risk in BRCA carriers and high-risk women. The purpose of this study was to describe the initial surgical outcomes and learning curve analysis associated with laparoendoscopic single-site (LESS) RRSO with and without hysterectomy. Methods: A retrospective, multi-institutional analysis of BRCA carriers and women at high risk for breast/ovarian cancer who underwent LESS RRSO with and without hysterectomy in 2009 was performed. Data collected included age, BMI, procedure, operative time, length of hospital stay, postoperative pain scores, and post operative complications. Student t-test, Pearson correlation coefficient, and multivariate linear regression were used for analysis. Results: A total of 58 patients were evaluated; 36 (63%) were BRCA1/2 carriers and 38 (63%) had breast cancer. Patients'' mean age and BMI were 46years and 27kg/m2, respectively. Most patients were Caucasian (76%), and at the time of prophylactic surgery, 53% of patients were undergoing active breast cancer treatment. Mean operative time was 38.1minutes (16–80minutes). All cases were performed successfully via the LESS approach, and there were no surgical complications. Multivariate linear regression analysis was done, and after controlling for study site, previous abdominal surgery, active cancer treatment, and BMI, operative time was only influence by number of cases performed, p =0.019. Conclusions: LESS RRSO is feasible and safe with favorable surgical and cosmetic outcomes. In our experience, surgical proficiency is possible after 10–15 cases. The LESS approach may be ideal for BRCA mutation carriers and breast cancer patients because of a short convalescence, permitting minimal interruption in any ongoing cancer treatment and the potential psychological benefits from improved cosmesis and pain control. Prospective studies are needed to assess the relative benefits of LESS compared with more conventional minimally invasive approaches. [Copyright &y& Elsevier]

Abstract: Ecdysis in arthropods is a complex process, regulated by many neurohormones, which must be released in a precisely coordinated manner. In insects, the ultimate hormone involved in this process is the cuticle tanning hormone, bursicon. Recently, this hormone has been identified in crustaceans. To further define the distribution of bursicon in crustacean nervous systems, and to compare hormone structures within the sub-phylum, cDNAs encoding both bursicon subunits were cloned and sequenced from the nervous system of the European lobster, Homarus gammarus, and expression patterns including those for CCAP determined using in-situ hybridisation, quantitative RT-PCR and immunohistochemistry. Full-length cDNAs encoded bursicon subunits of 121 amino acids (Average M r: 13365.48) for Burs α, 115 amino acids (Average M r: 12928.54) for Burs β. Amino acid sequences were most closely related to those of crabs, and for Burs β the sequence was identical to that of the American lobster, Homarus americanus. Complete co-localisation with CCAP in the VNC was seen. Copy numbers burs α, burs β and CCAP mRNAs were between 0.5 and 1.5×105 for both bursicon subunits, 0.5–6×105 per cdn neurone for CCAP. The terminal abdominal ganglia (AG 6–8) contained about 52 cdn-type neurons, making it the largest bursicon producing region in the CNS. Double labelling IHC using recombinant Carcinus Burs α and CCAP antisera demonstrated complete co-localisation in the VNC. On the basis of the results obtained, it is proposed that CCAP and bursicon release occur simultaneously during ecdysis in crustaceans. [Copyright &y& Elsevier]

Abstract: We report that dengue virus (DENV) methyltransferase sequentially methylates the guanine N-7 and ribose 2′-O positions of viral RNA cap (GpppA→m7GpppA→m7GpppAm). The order of two methylations is determined by the preference of 2′-O methylation for substrate m7GpppA-RNA to GpppA-RNA, and the 2′-O methylation is not absolutely dependent on the prior N-7 methylation. A mutation that completely abolished the 2′-O methylation attenuated DENV replication in cell culture, whereas another mutation that abolished both methylations was lethal for viral replication, suggesting that N-7 methylation is more important than 2′-O methylation in viral replication. The latter mutant with lethal replication could be rescued by trans complementation using a wild-type DENV replicon. Furthermore, we found that chimeric DENVs containing the West Nile virus methyltransferase, polymerase, or full-length NS5 were nonreplicative, but the replication defect could also be rescued through trans complementation using the wild-type DENV replicon. [ABSTRACT FROM AUTHOR]

Abstract: The hepatitis C virus (HCV) is a global health problem, with limited treatment options and no vaccine available. HCV uses components of the host cell to proliferate, including lipid droplets (LD) onto which HCV core proteins bind and facilitate viral particle assembly. We have measured the dynamics of HCV core protein-mediated changes in LDs and rates of LD movement on microtubules using a combination of coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence (TPF), and differential interference contrast (DIC) microscopies. Results show that the HCV core protein induces rapid increases in LD size. Particle tracking experiments show that HCV core protein slowly affects LD localization by controlling the directionality of LD movement on microtubules. These dynamic processes ultimately aid HCV in propagating and the molecules and interactions involved represent novel targets for potential therapeutic intervention. [Copyright &y& Elsevier]

Abstract: A significant amount of experimental data on the reaction kinetics for the mitochondrial DNA polymerase gamma exist, but interpreting that data is difficult due to the complex nature of the function of the polymerase. In order to model how these measured kinetics values for polymerase gamma affect the final function of the polymerase, the replication of an entire strand of mitochondrial DNA, we implement a stochastic simulation of the series of reaction events that the polymerase carries out. These reactions include the correct and incorrect polymerization events, exonuclease events which may remove both incorrectly and correctly matched base pairs, and the disassociation of the polymerase from the mitochondrial DNA template. We also describe other reactions which may be included, such as the addition of nucleoside analog tri-phosphates as substrates. The simulation analysis of the kinetics data is implemented through a standard Gillespie algorithm. We describe the methods necessary to define, code and test this algorithm, as well as describing the hardware and software options that are available. [ABSTRACT FROM AUTHOR]

Abstract: The higher plant chondriome is highly dynamic both in terms of the morphology and velocity of individual mitochondria within any given cell. Plant mitochondrial dynamics is a relatively new area of research, but one that has developed considerably over the early years of this century due to the generation of mitochondrially targeted fluorescent protein constructs and stably transformed lines. Several putative members of the plant mitochondrial division apparatus have been identified, but no genes have been identified as being involved in mitochondrial fusion. Despite the highly dynamic nature of plant mitochondria there is little specific scientific evidence linking mitochondrial dynamics to organelle and cell function. Two exceptions to this are the changes in mitochondrial dynamics that are early events during the induction of cell death programmes, and the extensive mitochondrial fusion that occurs before cytokinesis, although in both cases the role(s) of these events are a matter for conjecture. [ABSTRACT FROM AUTHOR]

Abstract: Future treatments for chronic liver disease are likely to involve manipulation of liver progenitor cells (LPCs). In the human, data characterising the regenerative response is limited and the origin of adult LPCs is unknown. However, these remain critical factors in the design of cell-based liver therapies. The developing human liver provides an ideal model to study cell lineage derivation from progenitors and to understand how foetal haematopoiesis and liver development might explain the nature of the adult LPC population. In 1st trimester human liver, portal venous endothelium (PVE) expressed adult LPC markers and markers of haematopoietic progenitor cells (HPCs) shared with haemogenic endothelium found in the embryonic dorsal aorta. Sorted PVE cells were able to generate hepatoblast-like cells co-expressing CK18 and CK19 in addition to Dlk/pref-1, E-cadherin, albumin and fibrinogen in vitro. Furthermore, PVE cells could initiate haematopoiesis. These data suggest that PVE shares phenotypical and functional similarities both with adult LPCs and embryonic haemogenic endothelium. This indicates that a temporal relationship might exist between progenitor cells in foetal liver development and adult liver regeneration, which may involve progeny of PVE. [Copyright &y& Elsevier]

Abstract: We examined the ability of adult predatory mites, Phytoseiulus persimilis Athias-Henriot, to search for and consume twospotted spider mites, Tetranychus urticae Koch, on cucumber plants that were manipulated to exhibit different architectures and prey distributions among leaves. Plants were manipulated to have either six small leaves or two large leaves; however, both plants types had similar total surface areas. Prey were located either all on one basal leaf or evenly distributed among all leaves. In one experiment, we measured prey-finding time when predators were released at the top or bottom of plants. Regardless of release point, P. persimilis found prey more rapidly when prey were on all leaves. On such plants, P. persimilis found prey patches first on leaves closest to the release point. Predator release point only affected prey-finding time when prey were located on the basal leaf of 6-leafed plants; it was longer when predators were released at the top. In a second experiment, we measured consumption and oviposition rates of predatory mites. Phytoseiulus persimilis consumed more prey on six-leafed than two-leaved plants regardless of prey distribution. Prey consumption and predator oviposition was highest on prey patches nearest the release point. We conclude that releasing P. persimilis over the plant canopy may not be effective during early stages of spider mite infestations on plants with a complex architecture. Both prey distribution and plant architecture should be considered when making decisions concerning release of P. persimilis in augmentative biological control programs. [Copyright &y& Elsevier]

Abstract: A rapid event-related fMRI arrow flanker task was used to study aging-associated decline in executive functions related to interference resolution. Older adults had more difficulty responding to Incongruent cues during the flanker task compared to the young adults; the response time difference between the Incongruent and Congruent conditions in the older group was over 50% longer compared to the young adults. In the frontal regions, differential activation (“Incongruent–Congruent” conditions) was observed in the inferior and middle frontal gyri in within-group analyses for both groups. However, the cluster was smaller in the older group and the centroid location was shifted by 19.7 mm. The left superior and medial frontal gyri also appeared to be specifically recruited by older adults during interference resolution, partially driven by errors. The frontal right lateralization found in the young adults was maintained in the older adults during successful trials. Interestingly, bilateral activation was observed when error trials were combined with successful trials highlighting the influence of brain activation associated with errors during cognitive processing. In conclusion, aging appears to result in modified functional regions that may contribute to reduced interference resolution. In addition, error processing should be considered and accounted for when studying age-related cognitive changes as errors may confound the interpretation of task specific age-related activation differences. [Copyright &y& Elsevier]

Abstract: Variants of rhodopsin, a complex of 11-cis retinal and opsin, cause retinitis pigmentosa (RP), a degenerative disease of the retina. Trafficking defects due to rhodopsin misfolding have been proposed as the most likely basis of the disease, but other potentially overlapping mechanisms may also apply. Pharmacological therapies for RP must target the major disease mechanism and contend with overlap, if it occurs. To this end, we have explored the molecular basis of rhodopsin RP in the context of pharmacological rescue with 11-cis retinal. Stable inducible cell lines were constructed to express wild-type opsin; the pathogenic variants T4R, T17M, P23A, P23H, P23L, and C110Y; or the nonpathogenic variants F220L and A299S. Pharmacological rescue was measured as the fold increase in rhodopsin or opsin levels upon addition of 11-cis retinal during opsin expression. Only Pro23 and T17M variants were rescued significantly. C110Y opsin was produced at low levels and did not yield rhodopsin, whereas the T4R, F220L, and A299S proteins reached near-wild-type levels and changed little with 11-cis retinal. All of the mutant rhodopsins exhibited misfolding, which increased over a broad range in the order F220L, A299S, T4R, T17M, P23A, P23H, P23L, as determined by decreased thermal stability in the dark and increased hydroxylamine sensitivity. Pharmacological rescue increased as misfolding decreased, but was limited for the least misfolded variants. Significantly, pathogenic variants also showed abnormal photobleaching behavior, including an increased ratio of metarhodopsin-I-like species to metarhodopsin-II-like species and aberrant photoproduct accumulation with prolonged illumination. These results, combined with an analysis of published biochemical and clinical studies, suggest that many rhodopsin variants cause disease by affecting both biosynthesis and photoactivity. We conclude that pharmacological rescue is promising as a broadly effective therapy for rhodopsin RP, particularly if implemented in a way that minimizes the photoactivity of the mutant proteins. [Copyright &y& Elsevier]

Abstract: Conformation affects a carotenoid’s ability to bind selectively to proteins. We calculated adiabatic energy profiles for rotating the ring end-groups around the C6nd for flexing of the ring with respect to the polyene chain. The choice of computational methods is important. A low, 4.2kcal/mol barrier to rotation exists for a β-ring. An 8.3kcal/mol barrier exists for rotation of an ε-ring. Rotation of the ε-ring is sensitive to substitution at C3. In the absence of external forces neither β- nor ε-rings are rotationally constrained. The nearly parallel alignment of the β-ring to the C6xis contrasts to the more perpendicular orientation of the ε-ring. Flexion of a β-ring to the minimized ε-ring conformation requires ∼23kcal/mol; extension of the ε-ring to the minimized β-ring conformation requires ∼8kcal/mol. Selectivity associated with β- versus ε-rings is dominated by the inability of the β-ring to flex to minimize protein/ring steric interactions and maximize van der Waal’s attractions with the binding site. [Copyright &y& Elsevier]

Abstract: During Pavlovian conditioning the expression of a conditioned response is typically taken as evidence that an association between a conditioned stimulus (CS) and an unconditioned stimulus (UCS) has been formed. However, learning-related changes in the unconditioned response (UCR) produced by a predictable UCS can also develop. Learning-related reductions in UCR magnitude are often referred to as UCR diminution. In the present study, we examined UCR diminution in the functional magnetic resonance imaging (fMRI) signal by pairing supra- and sub-threshold CS presentations with a UCS. UCR diminution was observed within several brain regions associated with fear learning and memory including the insula, inferior parietal lobe, ventromedial prefrontal cortex (PFC), dorsomedial PFC, and dorsolateral PFC. CS perception appeared to mediate UCR diminution within the ventromedial PFC and posterior cingulate cortex. UCRs within these regions were larger when the UCS followed an unperceived compared to a perceived CS. UCS expectancies appeared to modulate UCRs within the dorsomedial PFC, dorsolateral PFC, insula, and inferior parietal lobe. Activity within these regions showed an inverse relationship with participants'' UCS expectancies, such that as UCS expectancy increased UCR magnitude decreased. In addition, activity within the dorsomedial PFC, dorsolateral PFC, and insula showed a linear relationship with unconditioned skin conductance response (SCR) expression. These findings demonstrate UCR diminution within the fMRI signal, and suggest that UCS expectancies modulate prefrontal cortex responses to aversive stimuli. In turn, prefrontal cortex activity appears to modulate the expression of unconditioned SCRs. [Copyright &y& Elsevier]

Abstract: When large numbers of statistical tests are computed, such as in broad investigations of personality and behavior, the number of significant findings required before the total can be confidently considered beyond chance is typically unknown. Employing modern software, specially written code, and new procedures, the present article uses three sets of personality data to demonstrate how approximate randomization tests can evaluate (a) the number of significant correlations between a single variable and a large number of other variables, (b) the number of significant correlations between two large sets of variables, and (c) the average size of a large number of effects. Randomization tests can free researchers to fully explore large data sets and potentially have even wider applicability. [Copyright &y& Elsevier]

Abstract: The number of studies examining visual perspective during retrieval has recently grown. However, the way in which perspective has been conceptualized differs across studies. Some studies have suggested perspective is experienced as either a first-person or a third-person perspective, whereas others have suggested both perspectives can be experienced during a single retrieval attempt. This aspect of perspective was examined across three studies, which used different measurement techniques commonly used in studies of perspective. Results suggest that individuals can experience more than one perspective when recalling events. Furthermore, the experience of the two perspectives correlated differentially with ratings of vividness, suggesting that the two perspectives should not be considered in opposition of one another. We also found evidence of a gender effect in the experience of perspective, with females experiencing third-person perspectives more often than males. Future studies should allow for the experience of more than one perspective during retrieval. [Copyright &y& Elsevier]

Abstract: Prenatal inflammation prevents normal lung morphogenesis and leads to bronchopulmonary dysplasia (BPD), a common complication of preterm birth. We previously demonstrated in a bacterial endotoxin mouse model of BPD that disrupting fibronectin localization in the fetal lung mesenchyme causes arrested saccular airway branching. In this study we show that expression of the fibronectin receptor, integrin α8β1 is decreased in the lung mesenchyme in the same inflammation model suggesting it is required for normal lung development. We verified a role for integrin α8β1 in lung development using integrin α8-null mice, which develop fusion of the medial and caudal lobes as well as abnormalities in airway division. We further show in vivo and in vitro that α8-null fetal lung mesenchymal cells fail to form stable adhesions and have increased migration. Thus we propose that integrin α8β1 plays a critical role in lung morphogenesis by regulating mesenchymal cell adhesion and migration. Furthermore, our data suggest that disruption of the interactions between extracellular matrix and integrin α8β1 may contribute to the pathogenesis of BPD. [Copyright &y& Elsevier]

Abstract: Here we have simultaneously characterized the influence of inhibitors of peroxisome proliferator-activated receptor α (PPARα) and the mevalonate pathway on hepatocyte lipid metabolism and the subcellular localization of hepatitis C virus (HCV) RNA using two-photon fluorescence (TPF) and coherent anti-Stokes Raman scattering (CARS) microscopy. Using this approach, we demonstrate that modulators of PPARα signaling rapidly cause the dispersion of HCV RNA from replication sites and simultaneously induce lipid storage and increases in lipid droplet size. We demonstrate that reductions in the levels of cholesterol resulting from inhibition of the mevalonate pathway upregulates triglyceride levels. We also show that the rate of dispersion of HCV RNA is very rapid when using a PPARα antagonist. This occurs with a faster rate to that of direct inhibition of 3-hydroxy-3-methyglutaryl CoA reductase (HMG-CoA reductase) using lovastatin in living cells, demonstrating the potential therapeutic value of modulating host cell pathways as part of a strategy to eliminate chronic HCV infection. [Copyright &y& Elsevier]

Background: The need for surgeons to exhibit adequate communication skills is paramount to providing exemplary patient care. The manner in which patients are greeted by their surgeon sets the stage for the remainder of the clinical encounter. This study examined patients'' expectations for greetings upon meeting a surgeon for the first time. Materials and Methods: A convenience sample of 152 English-speaking patients (≥21 y of age) attending a university-based vascular surgery clinic were recruited to participate in this study. Eligible patients were interviewed prior to their consultation using valid and reliable questionnaires to obtain data about sociodemographic characteristics and expectations for greetings upon meeting a surgeon for the first time. Results: Patients'' mean age was 61.4 ± 14.6 approximately half (n = 81;54.3%) were male, and most were Caucasian (n = 148; 97.4%). Most (n = 132; 86.8%) patients wanted the surgeon to shake their hand, 113 (74.3%) wanted their first name to be used when a surgeon greets them, and 86 (56.6%) wanted a surgeon to introduce him/herself using his/her last name. Patients also desired for surgeons to be attentive/calm and make patient feel like a priority, adjust vocabulary and/or explain better, and be friendly, personable, polite, respectful, and/or courteous. Conclusions: Surgeons should shake hands, use patients'' first names, and introduce themselves using their last names when greeting patients for the first time. They should also be pleasant, personable, and make the patient feel like a priority. Additionally, surgeons should be cognizant of the way in which they present information to patients and verify understanding. [Copyright &y& Elsevier]

Abstract: Commentaries by Derrfuss and Mar [Derrfuss, J., Mar, R.A., 2009. Lost in localization: the need for a universal coordinate database. Neuroimage (doi:10.1016/j.neuroimage.2009.01.053).], Nielsen [Nielsen, F.A., 2009. Lost in localization: a solution with neuroinformatics 2.0? Neuroimage.], Hamilton [Hamilton, A., 2009. Lost in localization: a minimal middle way. Neuroimage.], and Laird and Fox [Laird, A.R., Fox, P.T., 2009 Lost in localization? The focus is meta-analysis. Neuroimage.] agree on the need for a comprehensive database of published stereotaxic coordinates but offer diverse views on how best to achieve this objective. Here, I summarize recent enhancements to the SumsDB database that increase its utility and decrease the impediments to data submission, thereby making it attractive as a resource that can approach comprehensive content in a realistic time frame. [Copyright &y& Elsevier]

Abstract: Transcription is a sophisticated multi-step process in which RNA polymerase II (Pol II) transcribes a DNA template into RNA in concert with a broad array of transcription initiation, elongation, capping, termination, and histone modifying factors. Recent global analyses of Pol II distribution have indicated that many genes are regulated during the elongation phase, shedding light on a previously underappreciated mechanism for controlling gene expression. Understanding how various factors regulate transcription elongation in living cells has been greatly aided by chromatin immunoprecipitation (ChIP) studies, which can provide spatial and temporal resolution of protein–DNA binding events. The coupling of ChIP with DNA microarray and high-throughput sequencing technologies (ChIP-chip and ChIP-seq) has significantly increased the scope of ChIP studies and genome-wide maps of Pol II or elongation factor binding sites can now be readily produced. However, while ChIP-chip/ChIP-seq data allow for high-resolution localization of protein–DNA binding sites, they are not sufficient to dissect protein function. Here we describe techniques for coupling ChIP-chip/ChIP-seq with genetic, chemical, and experimental manipulation to obtain mechanistic insight from genome-wide protein–DNA binding studies. We have employed these techniques to discern immature promoter-proximal Pol II from productively elongating Pol II, and infer a critical role for the transition between initiation and full elongation competence in regulating development and gene induction in response to environmental signals. [Copyright &y& Elsevier]

Abstract: Side population (SP) cells have recently been identified in a number of tissues although their phenotype and functional abilities are poorly understood. Surface marker characterisation and functional assessment of developing liver SP cells might allow for their isolation and manipulation using clinically relevant techniques. It was hypothesised that SP cells are present early during human liver development and contribute to haematopoietic and epithelial lineage generation. Whilst the SP population remained positive for CD34 during the 1st and 2nd trimester, 1st trimester SP cells were more highly enriched for haematopoietic and epithelial progenitor activity than those from the 2nd trimester in vitro. Marker expression and functional similarities indicate that SP cells in developing human liver may share a temporal relationship with oval/progenitor cells, responsible for liver regeneration after massive or chronic hepatic injury. Furthermore, modification of SP integrin expression during development suggests a potential adaptive interaction with niche components such as fibronectin. Improved understanding of developing human liver SP cells will contribute to the generation of novel cell-based therapies for liver disease. [Copyright &y& Elsevier]

Abstract: Ultrasonography has been used effectively to study reproduction in a variety of reptile species, but its application to crocodilians has been relatively limited. We present results from a study testing the efficacy of using ultrasonography to monitor reproduction in the American alligator, Alligator mississippiensis. Ultrasound results were then compared with plasma hormone levels. A total of 124 females were examined during March, April, May, and early June (2001–2003). Ultrasound results were validated on a series of reproductive females (n =14) necropsied for other studies. Previtellogenic follicles, vitellogenic follicles, recently shelled eggs, fully developed well-calcified eggs, and atretic follicles were readily discernible with ultrasound in mature females. Reproductive structures were observed in 57 females of which 43 were actively reproductive, while 14 were non-reproductive, but contained large atretic follicles from prior years. Oviducts were discernible in females with eggs. Ovarian state was also correlated with hormone levels. These results are in agreement with previous studies that showed that 50% or less of the adult female alligator population is reproductively active in a given year. Ultrasonography can be used to make an accurate assessment of reproductive condition in wild alligator populations. [Copyright &y& Elsevier]

Abstract: The virulence-associated alpha C protein (ACP) of Group B Streptococcus (GBS) facilitates the bacterial interaction with host epithelial cells. We previously demonstrated that phase-variable expression of ACP is controlled by variation in short-sequence repeat sequences present upstream of the promoter of bca, the gene encoding ACP. To determine if trans-acting transcriptional control also influences ACP expression, we developed an in silico prediction algorithm that identified a potential transcription-factor binding motif (TTT-N6-ATAT) in the bca upstream region. In vitro reporter gene expression studies confirmed that this motif is required for full ACP expression, and DNA-binding assays with a GBS protein extract demonstrated that the predicted site is bound by a protein. This approach demonstrates the utility of in silico genomic predictive methods in the study of GBS regulatory mechanisms. [Copyright &y& Elsevier]

Background: Different mechanisms of injury (MOI), such as motor vehicle crashes, falls, or pedestrians struck by motor vehicle impart varying degrees of force and energy transfer that may impact outcomes. This study analyzed the independent relationship between MOI and mortality and functional outcomes following blunt trauma among adults. Materials and methods: Retrospective review of blunt trauma patients 15 y and older in the National Trauma Data Bank from 2001 to 2005. Primary outcome measures were mortality and presence of functional deficit in speech, walking, or feeding at discharge. MOI categories, identified by ICD-9 E codes, were motor vehicle crash, pedestrian struck by motor vehicle, motorcycle crash, falls at same level and from any height, and bicycle crash. A multiple regression analysis was performed adjusting for patient demographics and injury severity variables with motor vehicle crash as the reference mechanism group. Results: Over the period studied, 515,464 patients met inclusion criteria. Mean Injury Severity Score (16.9), mortality rate (11%), and extremity injury (20%) were highest among pedestrians struck by motor vehicle, and head injury (16%) highest for motorcyclists. Overall, 52% had impaired ambulation, 16% impaired feeding, and 10% impaired speech. Adjusted odds of death, impaired walking, and impaired speaking were highest for pedestrians struck by motor vehicle, and impaired feeding highest for motorcyclists. Conclusion: After adjusting for confounders, MOI was found to independently predict mortality and functional impairment at hospital discharge. Current injury assessment models could be greatly enhanced by including MOI, and we propose routine adjustment for injury mechanism in trauma outcomes research. [Copyright &y& Elsevier]

Abstract: Descending price auctions are adopted for goods that must be sold quickly and in private values environments, for instance in flower, fish, and tobacco auctions. In this paper, we introduce efficient descending auctions for two environments: multiple non-identical items and buyers with unit-demand valuations; and multiple identical items and buyers with non-increasing marginal values. Our auctions are designed using the notion of universal competitive equilibrium (UCE) prices and they terminate with UCE prices, from which the Vickrey payments can be determined. For the unit-demand setting, our auction maintains linear and anonymous prices. For the homogeneous items setting, our auction maintains a single price and adopts Ausubel''s notion of “clinching” to compute the final payments dynamically. The auctions support truthful bidding in an ex post Nash equilibrium and terminate with an efficient allocation. In simulation, we illustrate the speed and elicitation advantages of these auctions over their ascending price counterparts. [Copyright &y& Elsevier]

Abstract: The internecine war over the relative importance of persons and situations, triggered 40 years ago by Walter Mischel’s Personality and Assessment, is largely over, so it is time for researchers to develop an agenda for personality psychology in the postwar era. The possibilities include a return to the status quo ante characterized by questionnaire-based research, focusing on narrower trait constructs than the “global” traits that have undergone so much criticism, and concentrating upon within-person variance (as well as or even instead of between person variance) in behavior. Each of these possibilities offers some promise but also hazards that may be under-appreciated. The present article suggests that personality theory and research be re-organized in terms of the personality triad of persons, behaviors, and situations. A precondition for understanding the elements of this triad is better conceptualization and measurement of behavior and, especially, situations. While the interactions among these elements may turn out to be important, a first order of business is to understand the main effects of each element, a formidable but exciting research agenda that will entail a turn to broadly descriptive research rather than the testing of narrow, isolated hypotheses. Looking further ahead, a post-interactionist personality psychology may someday recognize that personality is a latent construct only indirectly indicated through behavior, and the ultimate understanding of that construct will be empirically tested by the ability to predict behavior in new and unique situations. [Copyright &y& Elsevier]

Abstract: This paper presents a new framework for generating triangular meshes from textured color images. The proposed framework combines a texture classification technique, called W-operator, with Imesh, a method originally conceived to generate simplicial meshes from gray scale images. An extension of W-operators to handle textured color images is proposed, which employs a combination of RGB and HSV channels and Sequential Floating Forward Search guided by mean conditional entropy criterion to extract features from the training data. The W-operator is built into the local error estimation used by Imesh to choose the mesh vertices. Furthermore, the W-operator also enables to assign a label to the triangles during the mesh construction, thus allowing to obtain a segmented mesh at the end of the process. The presented results show that the combination of W-operators with Imesh gives rise to a texture classification-based triangle mesh generation framework that outperforms pixel based methods. [Copyright &y& Elsevier]

Abstract: We model the process of directed evolution (DE) in silico using genetic algorithms. Making use of the NK fitness landscape model, we analyse the effects of mutation rate, crossover and selection pressure on the performance of DE. A range of values of K, the epistatic interaction of the landscape, are considered, and high- and low-throughput modes of evolution are compared. Our findings suggest that for runs of or around ten generations’ duration—as is typical in DE—there is little difference between the way in which DE needs to be configured in the high- and low-throughput regimes, nor across different degrees of landscape epistasis. In all cases, a high selection pressure (but not an extreme one) combined with a moderately high mutation rate works best, while crossover provides some benefit but only on the less rugged landscapes. These genetic algorithms were also compared with a “model-based approach” from the literature, which uses sequential fixing of the problem parameters based on fitting a linear model. Overall, we find that purely evolutionary techniques fare better than do model-based approaches across all but the smoothest landscapes. [Copyright &y& Elsevier]

Summary: Jaagsiekte sheep retrovirus is a betaretrovirus and the causative agent of pulmonary adenocarcinoma, a transmissible lung tumour of sheep. Here we report the crystal structure of the capsid amino-terminal domain and examine the self-association properties of Jaagsiekte sheep retrovirus capsid. We find that the structure is remarkably similar to the amino-terminal domain of the alpharetrovirus, avian leukosis virus, revealing a previously undetected evolutionary similarity. Examination of capsid self-association suggests a mode of assembly not driven by the strong capsid carboxy-terminal domain interactions that characterise capsid assembly in the lentiviruses. Based on these data, we propose this structure provides a model for the capsid of betaretroviruses including the HML-2 family of endogenous human betaretroviruses. [Copyright &y& Elsevier]

Abstract: The bacterial community associated with skin lesions of the sea urchin Tripneustes gratilla was investigated using 16S ribosomal RNA gene cloning and fluorescent in situ hybridization (FISH). All clones were classified in the Alphaproteobacteria, Gammaproteobacteria and Cytophaga–Flexibacter–Bacteroides (CFB) bacteria. Most of the Alphaproteobacteria were related to the Roseobacter lineage and to bacteria implicated in marine diseases. The majority of the Gammaproteobacteria were identified as Vibrio while CFB represented only 9% of the total clones. FISH analyses showed that Alphaproteobacteria, CFB bacteria and Gammaproteobacteria accounted respectively for 43%, 38% and 19% of the DAPI counts. The importance of the methods used is emphasized. [Copyright &y& Elsevier]

Abstract: TEM-1 β-lactamase confers bacterial resistance to penicillin antibiotics and has acquired mutations that permit the enzyme to hydrolyze extended-spectrum cephalosporins or to avoid inactivation by β-lactamase inhibitors. However, many of these substitutions have been shown to reduce activity against penicillin antibiotics and/or result in loss of stability for the enzyme. In order to gain more information concerning the tradeoffs associated with active site substitutions, a genetic selection was used to find second site mutations that partially restore ampicillin resistance levels conferred by an R244A active site TEM-1 β-lactamase mutant. An L201P substitution distant from the active site that enhanced ampicillin resistance levels and increased protein expression levels of the R244A TEM-1 mutant was identified. The L201P substitution also increases the ampicillin resistance levels and restores expression levels of a poorly expressed TEM-1 mutant with a core-disrupting substitution. In vitro thermal denaturation of purified protein indicated that the L201P mutation increases the T m value of the TEM-1 enzyme. The X-ray structure of the L201P TEM-1 mutant was determined to gain insight into the increase in enzyme stability. The proline substitution occurs at the N-terminus of an α-helix and may stabilize the enzyme by reducing the helix dipole, as well as by lowering the conformational entropy cost of folding due to the reduced number of conformations available in the unfolded state. Collectively, the data suggest that L201P promotes tolerance of some deleterious TEM-1 mutations by enhancing the protein stability of these mutants. [Copyright &y& Elsevier]