bluuebunny/crossref_metadata_2025 huggingface dataset:
Sarcolemmal-restricted localization of functional ClC-1 channels in mouse skeletal muscle
Authors: Lueck John D. , Rossi Ann E. , Thornton Charles A. , Campbell Kevin P. , Dirksen Robert T.
Published: November 2010

Skeletal muscle fibers exhibit a high resting chloride conductance primarily determined by ClC-1 chloride channels that stabilize the resting membrane potential during repetitive stimulation. Although the importance of ClC-1 channel activity in maintaining normal muscle excitability is well appreciated, the subcellular location of this conductance remains highly controversial. Using a three-pronged multidisciplinary approach, we determined the location of functional ClC-1 channels in adult mouse skeletal muscle. First, formamide-induced detubulation of single flexor digitorum brevis (FDB) muscle fibers from 15–16-day-old mice did not significantly alter macroscopic ClC-1 current magnitude (at −140 mV; −39.0 ± 4.5 and −42.3 ± 5.0 nA, respectively), deactivation kinetics, or voltage dependence of channel activation (V1/2 was −61.0 ± 1.7 and −64.5 ± 2.8 mV; k was 20.5 ± 0.8 and 22.8 ± 1.2 mV, respectively), despite a 33% reduction in cell capacitance (from 465 ± 36 to 312 ± 23 pF). In paired whole cell voltage clamp experiments, where ClC-1 activity was measured before and after detubulation in the same fiber, no reduction in ClC-1 activity was observed, despite an ∼40 and 60% reduction in membrane capacitance in FDB fibers from 15–16-day-old and adult mice, respectively. Second, using immunofluorescence and confocal microscopy, native ClC-1 channels in adult mouse FDB fibers were localized within the sarcolemma, 90° out of phase with double rows of dihydropyridine receptor immunostaining of the T-tubule system. Third, adenoviral-mediated expression of green fluorescent protein–tagged ClC-1 channels in adult skeletal muscle of a mouse model of myotonic dystrophy type 1 resulted in a significant reduction in myotonia and localization of channels to the sarcolemma. Collectively, these results demonstrate that the majority of functional ClC-1 channels localize to the sarcolemma and provide essential insight into the basis of myofiber excitability in normal and diseased skeletal muscle.
A Preliminary Report on My Life in Science
Authors: Rapoport Tom A.
Published: November 2010

I describe my wanderings from the United States to East Germany and back. I hope this gives a glimpse of science in East Germany and encourages people who do science under less than favorable conditions. Although elements of my story are unique, the main points are general: don't be afraid to start something new; it pays to be persistent; and science is a passion—if it feels like fun, you've probably got it right.
Diversifying the Biological Sciences: Past Efforts and Future Challenges
Authors: Hayes Tyrone B.
Published: November 2010

I am honored to receive the E. E. Just Award for 2010. In my invited essay, I have opted to discuss the state of diversity in the biological sciences with some recommendations for moving forward toward a more positive and inclusive academy. The need to develop cohorts of minority scientists as support groups and to serve as role models within our institutions is stressed, along with the need to ensure that minority scientists are truly included in all aspects of the academy. It is imperative that we increase our efforts to prepare for the unique challenges that we will face as the United States approaches a “majority minority” population in the next 50 years.
Charting the Secretory Pathway in a Simple Eukaryote
Authors: Schekman Randy
Published: November 2010

George Palade, a founding father of cell biology and of the American Society for Cell Biology (ASCB), established the ultrastructural framework for an analysis of how proteins are secreted and membranes are assembled in eukaryotic cells. His vision inspired a generation of investigators to probe the molecular mechanisms of protein transport. My laboratory has dissected these pathways with complementary genetic and biochemical approaches. Peter Novick, one of my first graduate students, isolated secretion mutants of Saccharomyces cerevisiae, and through cytological analysis of single and double mutants and molecular cloning of the corresponding SEC genes, we established that yeast cells use a secretory pathway fundamentally conserved in all eukaryotes. A biochemical reaction that recapitulates the first half of the secretory pathway was used to characterize Sec proteins that comprise the polypeptide translocation channel in the endoplasmic reticulum (ER) membrane (Sec61) and the cytoplasmic coat protein complex (COPII) that captures cargo proteins into transport vesicles that bud from the ER.
Plants Respond to Pathogen Infection by Enhancing the Antifungal Gene Expression of Root-Associated Bacteria
Authors: Jousset Alexandre , Rochat Laurène , Lanoue Arnaud , Bonkowski Michael , Keel Christoph , Scheu Stefan
Published: November 2010

Plant health and fitness widely depend on interactions with soil microorganisms. Some bacteria such as pseudomonads can inhibit pathogens by producing antibiotics, and controlling these bacteria could help improve plant fitness. In the present study, we tested whether plants induce changes in the antifungal activity of root-associated bacteria as a response to root pathogens. We grew barley plants in a split-root system with one side of the root system challenged by the pathogen Pythium ultimum and the other side inoculated with the biocontrol strain Pseudomonas fluorescens CHA0. We used reporter genes to follow the expression of ribosomal RNA indicative of the metabolic state and of the gene phlA, required for production of 2,4-diacetylphloroglucinol, a key component of antifungal activity. Infection increased the expression of the antifungal gene phlA. No contact with the pathogen was required, indicating that barley influenced gene expression by the bacteria in a systemic way. This effect relied on increased exudation of diffusible molecules increasing phlA expression, suggesting that communication with rhizosphere bacteria is part of the pathogen response of plants. Tripartite interactions among plants, pathogens, and bacteria appear as a novel determinant of plant response to root pathogens.
Evaluation of Six Models to Estimate Ascospore Maturation in Venturia pyrina
Authors: Eikemo H. , Gadoury D. M. , Spotts R. A. , Villalta O. , Creemers P. , Seem R. C. , Stensvand A.
Published: November 2010

Estimates of ascospore maturity generated by models developed for Venturia pyrina in Victoria, Australia (NV and SV), Oregon, United States (OR), and Italy (IT) or for V. inaequalis in New Hampshire, United States (NH-1) or modified in Norway (NH-2) were compared with observed field ascospore release of V. pyrina from 21 site–year combinations. The models were also compared with ascospore release data from laboratory assays. In the laboratory assays, the forecasts of the NH-1 and NH-2 models provided the best fit to observed spore release. Under field conditions, the lag phases and slope coefficients of all models differed from those of observed release of ascospores. Identifying the precise time of bud break of pear to initiate degree-day accumulation was problematic at both Australian sites. This resulted in a higher deviance between bud break and first released ascospore compared with the sites in Norway and Belgium. Linear regressions of observed release against forecasted maturity generated similarly high concordance correlation coefficients. However, where differences were noted, they most often favored models that included adjustment for dry periods. The NH-2, IT, and NV models using pooled data also provided the most accurate estimates of 95% ascospore depletion, a key event in many disease management programs.
Colletotrichum lindemuthianum Races Prevalent on Dry Beans in North Dakota and Potential Sources of Resistance
Authors: Goswami Rubella S. , del Rio-Mendoza Luis E. , Lamppa Robin S. , Prischmann Jeff
Published: November 2010

Anthracnose caused by Colletotrichum lindemuthianum is one of the most important diseases of dry edible beans in the major production areas worldwide. This pathogen is highly variable, with numerous races. Disease management relies heavily on genetic resistance and use of clean seed. Genetic resistance is controlled by major resistance genes conferring protection against specific races of the pathogen. Therefore, knowledge of the pathogen population in a region is essential for effective screening of germplasm. Surveys were conducted for more than 6 years in North Dakota, the largest dry-bean-growing state in the United States, and seed samples submitted for certification were assessed to identify the C. lindemuthianum races prevalent in the region. A collection of commercial cultivars from different market classes of dry bean was also screened for resistance to these races. Disease incidence was found to be low in most years. However, in addition to the previously reported races of anthracnose 7, 73, and 89, two new races, 1153 and 1161, previously never reported in the United States, were identified and the commercial cvs. Montcalm, Avalanche, Vista, and Sedona where found to possess resistance to these races.
Detection and Monitoring ofGreeneria uvicolaandColletotrichum acutatumDevelopment on Grapevines by Real-Time PCR
Authors: Samuelian Suren K. , Greer Lindsay A. , Savocchia Sandra , Steel Christopher C.
Published: November 2010

Bitter rot (Greeneria uvicola) and ripe rot (Colletotrichum acutatum, syn. C. simmondsii) occur frequently in subtropical grape-growing regions of Australia, where they cause yield loss and bitter taints in wine. To further advance the epidemiological studies of G. uvicola and C. acutatum and contribute toward their effective management and control, a rapid and reliable species-specific real-time polymerase chain reaction (PCR) method was developed based on the polymorphic portion of the internal transcribed spacer region of the two fungi. It was found that, within 6 to 8 h postinoculation, the assay could detect as little as 20 fg of genomic DNA and 10 conidia for both species. Artificially and naturally infected grape inflorescences and mature berries were analyzed by both conventional plating methods and real-time PCR. Fungal presence was demonstrated on all plant material but development was observed only on mature berries. The results demonstrate that the real-time PCR technique is a highly specific, rapid, and sensitive method that can be used to detect and study the dynamics of G. uvicola and C. acutatum during different stages of infection and on different grape tissues.
Plasma Exchange After Initial Intravenous Immunoglobulin Treatment in Guillain-Barré Syndrome: Critical Reassessment of Effectiveness and Cost-Efficiency
Authors: Oczko-Walker Malgorzata , Manousakis Georgios , Wang Sijan , Malter James S , Waclawik Andrew J
Published: November 2010

Objectives:

To assess whether intravenous immunoglobulin (IVIG) followed by plasma exchange (PE) is more effective for patients with Guillain-Barré syndrome compared with IVIG alone.

Methods:

Retrospective chart review of 46 patients treated for Guillain-Barré syndrome between 1995 and 2005 was performed. Patients were divided into four subgroups based on treatment received (IVIG, PE, IVIG + PE, or neither). Disability grade on admission, after completion of IVIG, and on the day of discharge from hospital (DGD) were assessed. DGD was the primary outcome measure. Duration of hospitalization, costs, duration of symptoms before treatment, and interval between IVIG and initiation of PE were analyzed.

Results:

Mean disability grade on admission was similar for all groups. DGD was significantly lower for the IVIG group (P < 0.001) than other groups. Compared with admission, patients treated with IVIG + PE had more severe impairment after completion of IVIG (P = 0.044) but did not show significant improvement after PE. Disability grade on admission and DGD scores for patients treated earlier (less than 14 days after onset of symptoms) versus later (greater than 14 days) were not significantly different. Duration of hospitalization was longer in patients receiving IVIG + PE versus IVIG alone (P < 0.001). The cost of treatment was significantly higher in the IVIG + PE subgroup (P < 0.001). No correlation between interval from IVIG to PE onset and DGD score was found.

Conclusions:

We found no association between PE after IVIG and improved short-term outcomes of patients with Guillain-Barré syndrome, but there was an association with an increase in cost and duration of hospitalization. There was no association between the timing of PE after IVIG and the short-term outcome. Prospective studies are needed to clarify whether the cost/benefit ratio favors the routine use of this therapeutic approach.
Transmission of Maternal Muscle-Specific Tyrosine Kinase (MuSK) to Offspring: Report of Two Cases
Authors: Murray Earnest L , Kedar Sachin , Vedanarayanan V V
Published: November 2010

Familial occurrence of myasthenia gravis is uncommon and reports of maternal transmission of muscle-specific tyrosine kinase (MuSK) antibody myasthenia are rarer still. We report two families with maternal transmission of MuSK antibody myasthenia gravis to the offspring by different mechanisms. The first family demonstrates transmission genetic susceptibility of inheriting myasthenia gravis from MuSK antibodies, whereas the second one demonstrates transplacental transmission of MuSK antibodies at birth.
A Review: The Use of Rituximab in Neuromuscular Diseases
Authors: Ibrahim Homam , Dimachkie Mazen M , Shaibani Aziz
Published: November 2010

Autoimmunity plays a major role in the pathogenesis of many neuromuscular disorders such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barré syndrome, polymyositis, dermatomyositis, myasthenia gravis, Lambert Eaton syndrome, and stiff person syndrome. Although most of these disorders respond favorably to the commonly used immunomodulatory agents such as steroids, intravenous gamma globulin, plasmapheresis, and chemotherapy, some are initially refractory, whereas others gradually lose responsiveness. Therefore, alternative, selective, and novel immunosuppressive agents are used to treat these cases. Among these agents, rituximab has shown promise in some of the neuromuscular disorders with minimal side effects. Rituximab is a genetically engineered antibody that depletes CD20+ B-cells and is Food and Drug Administration- approved for treatment of non-Hodgkin lymphoma, CD20+ CLL, and rheumatoid arthritis. It carries a favorable side effects profile. However, evidence of efficacy is limited to case series and large prospective randomized controlled trials are lacking. In this article, we review and discuss the available literature on rituximab in treatment of various autoimmune neuromuscular diseases.
Living on the edge of chaos: minimally nonlinear models of genetic regulatory dynamics
Authors: Hanel Rudolf , Pöchacker Manfred , Thurner Stefan
Published: November 2010

Linearized catalytic reaction equations (modelling, for example, the dynamics of genetic regulatory networks), under the constraint that expression levels, i.e. molecular concentrations of nucleic material, are positive, exhibit non-trivial dynamical properties, which depend on the average connectivity of the reaction network. In these systems, an inflation of theedge of chaosand multi-stability have been demonstrated to exist. The positivity constraint introduces a nonlinearity, which makes chaotic dynamics possible. Despite the simplicity of suchminimally nonlinear systems, their basic properties allow us to understand the fundamental dynamical properties of complex biological reaction networks. We analyse the Lyapunov spectrum, determine the probability of finding stationary oscillating solutions, demonstrate the effect of the nonlinearity on the effective in- and out-degree of theactive interaction network, and study how the frequency distributions of oscillatory modes of such a system depend on the average connectivity.
Fractal structures in stenoses and aneurysms in blood vessels
Authors: Schelin Adriane B. , Károlyi György , de Moura Alessandro P. S. , Booth Nuala A. , Grebogi Celso
Published: November 2010

Recent advances in the field of chaotic advection provide the impetus to revisit the dynamics of particles transported by blood flow in the presence of vessel wall irregularities. The irregularity, being either a narrowing or expansion of the vessel, mimicking stenoses or aneurysms, generates abnormal flow patterns that lead to a peculiar filamentary distribution of advected particles, which, in the blood, would include platelets. Using a simple model, we show how the filamentary distribution depends on the size of the vessel wall irregularity, and how it varies under resting or exercise conditions. The particles transported by blood flow that spend a long time around a disturbance either stick to the vessel wall or reside on fractal filaments. We show that the faster flow associated with exercise creates widespread filaments where particles can get trapped for a longer time, thus allowing for the possible activation of such particles. We argue, based on previous results in the field of active processes in flows, that the non-trivial long-time distribution of transported particles has the potential to have major effects on biochemical processes occurring in blood flow, including the activation and deposition of platelets. One aspect of the generality of our approach is that it also applies to other relevant biological processes, an example being the coexistence of plankton species investigated previously.
Modelling the mobility of living organisms in heterogeneous landscapes: does memory improve foraging success?
Authors: Boyer Denis , Walsh Peter D.
Published: November 2010

Thanks to recent technological advances, it is now possible to track with an unprecedented precision and for long periods of time the movement patterns of many living organisms in their habitat. The increasing amount of data available on single trajectories offers the possibility of understanding how animals move and of testing basic movement models. Random walks have long represented the main description for micro-organisms and have also been useful to understand the foraging behaviour of large animals. Nevertheless, most vertebrates, in particular humans and other primates, rely on sophisticated cognitive tools such as spatial maps, episodic memory and travel cost discounting. These properties call for other modelling approaches of mobility patterns. We propose a foraging framework where a learning mobile agent uses a combination of memory-based and random steps. We investigate how advantageous it is to use memory for exploiting resources in heterogeneous and changing environments. An adequate balance of determinism and random exploration is found to maximize the foraging efficiency and to generate trajectories with an intricate spatio-temporal order, where travel routes emerge without multi-step planning. Based on this approach, we propose some tools for analysing the non-random nature of mobility patterns in general.
Complex dynamics of our economic life on different scales: insights from search engine query data
Authors: Preis Tobias , Reith Daniel , Stanley H. Eugene
Published: November 2010

Search engine query data deliver insight into the behaviour of individuals who are the smallest possible scale of our economic life. Individuals are submitting several hundred million search engine queries around the world each day. We study weekly search volume data for various search terms from 2004 to 2010 that are offered by the search engine Google for scientific use, providing information about our economic life on an aggregated collective level. We ask the question whether there is a link between search volume data and financial market fluctuations on a weekly time scale. Both collective ‘swarm intelligence’ of Internet users and the group of financial market participants can be regarded as a complex system of many interacting subunits that react quickly to external changes. We find clear evidence that weekly transaction volumes of S&P 500 companies are correlated with weekly search volume of corresponding company names. Furthermore, we apply a recently introduced method for quantifying complex correlations in time series with which we find a clear tendency that search volume time series and transaction volume time series show recurring patterns.
Applying a quantitative genetics framework to behavioural syndrome research
Authors: Dochtermann Ned A. , Roff Derek A.
Published: November 2010

Current interest in behavioural syndromes, or ‘animal personalities’, reinforces a need for behavioural ecologists to adopt a multivariate view of phenotypes. Fortunately, many of the methodological and theoretical issues currently being dealt with by behavioural ecologists within the context of behavioural syndromes have previously been investigated by researchers in other areas of evolutionary ecology. As a result of these previous efforts, behavioural syndrome researchers have considerable theory and a wide range of tools already available to them. Here, we discuss aspects of quantitative genetics useful for understanding the multivariate phenotype as well as the relevance of quantitative genetics to behavioural syndrome research. These methods not only allow the proper characterization of the multivariate behavioural phenotype and genotype—including behaviours within, among and independent of behavioural syndrome structures—but also allow predictions as to how populations may respond to selection on behaviours within syndromes. An application of a quantitative genetics framework to behavioural syndrome research also clarifies and refines the questions that should be asked.
Evolutionary models of metabolism, behaviour and personality
Authors: Houston Alasdair I.
Published: November 2010

I explore the relationship between metabolism and personality by establishing how selection acts on metabolic rate and risk-taking in the context of a trade-off between energy and predation. Using a simple time budget model, I show that a high resting metabolic rate is not necessarily associated with a high daily energy expenditure. The metabolic rate that minimizes the time spent foraging does not maximize the net gain rate while foraging, and it is not always advantageous for animals to have a higher metabolic rate when food availability is high. A model based on minimizing the ratio of mortality rate to net gain rate is used to determine how a willingness to take risks should be correlated with metabolic rate. My results establish that it is not always advantageous for animals to take greater risks when metabolic rate is high. When foraging intensity and metabolic rate coevolve, I show that in a particular case different combinations of foraging intensity and metabolic rate can have equal fitness.
The building-up of social relationships: behavioural types, social networks and cooperative breeding in a cichlid
Authors: Schürch Roger , Rothenberger Susan , Heg Dik
Published: November 2010

Consistent individual differences in behavioural types may not only cause variation in life-history decisions, but may also affect the choice of social partners and sociality in general. Here, we tested whether and how behavioural type influences the establishment of social ties using the cooperatively breeding cichlid,Neolamprologus pulcher. In a habitat saturation experiment with individuals pre-tested for behavioural type, we first analysed whether behavioural type affected the likelihood of settlement (i.e. social status), group sizes, and the types of dominant and subordinate individuals accepted as group members. Corrected for effects of body size and sex, the behavioural type did not affect settlement. However, bold dominant males only accepted smaller females, and grouped with bold subordinates, while shy dominant males accepted larger females than themselves, and grouped with shy subordinates. Second, we analysed the relationships between behavioural type and the aggressiveness or affiliation social network. Behavioural type significantly affected the number and quality of connections within the two networks. We show that behavioural types affect group composition, social networks and status achieved, in interaction with body size. Thus, the interactions within groups may depend not only on age, size and sex, but also on the behavioural type of the individuals involved.
What can whole genome expression data tell us about the ecology and evolution of personality?
Authors: Bell Alison M. , Aubin-Horth Nadia
Published: November 2010

Consistent individual differences in behaviour, aka personality, pose several evolutionary questions. For example, it is difficult to explain within-individual consistency in behaviour because behavioural plasticity is often advantageous. In addition, selection erodes heritable behavioural variation that is related to fitness, therefore we wish to know the mechanisms that can maintain between-individual variation in behaviour. In this paper, we argue that whole genome expression data can reveal new insights into the proximate mechanisms underlying personality, as well as its evolutionary consequences. After introducing the basics of whole genome expression analysis, we show how whole genome expression data can be used to understand whether behaviours in different contexts are affected by the same molecular mechanisms. We suggest strategies for using the power of genomics to understand what maintains behavioural variation, to study the evolution of behavioural correlations and to compare personality traits across diverse organisms.
Coping styles and behavioural flexibility: towards underlying mechanisms
Authors: Coppens Caroline M. , de Boer Sietse F. , Koolhaas Jaap M.
Published: November 2010

A coping style (also termed behavioural syndrome or personality) is defined as a correlated set of individual behavioural and physiological characteristics that is consistent over time and across situations. This relatively stable trait is a fundamental and adaptively significant phenomenon in the biology of a broad range of species, i.e. it confers differential fitness consequences under divergent environmental conditions. Behavioural flexibility appears to be an important underlying attribute or feature of the coping style that might explain consistency across situations. Proactive coping is characterized by low flexibility expressed as rather rigid, routine-like behavioural tendencies and reduced impulse control (behavioural inhibition) in operant conditioning paradigms. This article summarizes some of the evidence that individual differentiation in behavioural flexibility emerges as a function of underlying variability in the activation of a brain circuitry that includes the prefrontal cortex and its key neurochemical signalling pathways (e.g. dopaminergic and serotonergic input). We argue that the multidimensional nature of animal personality and the terminology used for the various dimensions should reflect the differential pattern of activation of the underlying neuronal network and the behavioural control function of its components. Accordingly, unravelling the molecular mechanisms that give rise to individual differences in the coping style will be an important topic in biobehavioural neurosciences, ecology and evolutionary biology.
Evolutionary and ecological approaches to the study of personality
Authors: Réale Denis , Dingemanse Niels J. , Kazem Anahita J. N. , Wright Jonathan
Published: November 2010

This introduction to the themed issue on Evolutionary and ecological approaches to the study of personality provides an overview of conceptual, theoretical and methodological progress in research on animal personalities over the last decade, and places the contributions to this volume in context. The issue has three main goals. First, we aimed to bring together theoreticians to contribute to the development of models providing adaptive explanations for animal personality that could guide empiricists, and stimulate exchange of ideas between the two groups of researchers. Second, we aimed to stimulate cross-fertilization between different scientific fields that study personality, namely behavioural ecology, psychology, genomics, quantitative genetics, neuroendocrinology and developmental biology. Third, we aimed to foster the application of an evolutionary framework to the study of personality.
Canonical and noncanonical Wnts use a common mechanism to activate completely unrelated coreceptors
Authors: Grumolato Luca , Liu Guizhong , Mong Phyllus , Mudbhary Raksha , Biswas Romi , Arroyave Randy , Vijayakumar Sapna , Economides Aris N. , Aaronson Stuart A.
Published: November 2010

Wnt ligands signal through β-catenin and are critically involved in cell fate determination and stem/progenitor self-renewal. Wnts also signal through β-catenin-independent or noncanonical pathways that regulate crucial events during embryonic development. The mechanism of noncanonical receptor activation and how Wnts trigger canonical as opposed to noncanonical signaling have yet to be elucidated. We demonstrate here that prototype canonical Wnt3a and noncanonical Wnt5a ligands specifically trigger completely unrelated endogenous coreceptors—LRP5/6 and Ror1/2, respectively—through a common mechanism that involves their Wnt-dependent coupling to the Frizzled (Fzd) coreceptor and recruitment of shared components, including dishevelled (Dvl), axin, and glycogen synthase kinase 3 (GSK3). We identify Ror2 Ser 864 as a critical residue phosphorylated by GSK3 and required for noncanonical receptor activation by Wnt5a, analogous to the priming phosphorylation of low-density receptor-related protein 6 (LRP6) in response to Wnt3a. Furthermore, this mechanism is independent of Ror2 receptor Tyr kinase functions. Consistent with this model of Wnt receptor activation, we provide evidence that canonical and noncanonical Wnts exert reciprocal pathway inhibition at the cell surface by competition for Fzd binding. Thus, different Wnts, through their specific coupling and phosphorylation of unrelated coreceptors, activate completely distinct signaling pathways.
The essence of senescence: Figure 1.
Authors: Kuilman Thomas , Michaloglou Chrysiis , Mooi Wolter J. , Peeper Daniel S.
Published: November 2010

Almost half a century after the first reports describing the limited replicative potential of primary cells in culture, there is now overwhelming evidence for the existence of “cellular senescence” in vivo. It is being recognized as a critical feature of mammalian cells to suppress tumorigenesis, acting alongside cell death programs. Here, we review the various features of cellular senescence and discuss their contribution to tumor suppression. Additionally, we highlight the power and limitations of the biomarkers currently used to identify senescent cells in vitro and in vivo.
Crystal chemistry of transition metal diarsenates M
2As2O7 (M = Mn, Co, Ni, Zn): variants of the thortveitite structure
Authors: Weil Matthias , Stöger Berthold
Published: November 2010

The structures of the 3d divalent transition-metal diarsenates M
2As2O7 (M = Mn, Co, Ni, Zn) can be considered as variants of the monoclinic (C2/m) thortveitite [Sc2Si2O7] structure type with a ≃ 6.7, b ≃ 8.5, c ≃ 4.7 Å, α ≃ 90, β ≃ 102, γ ≃ 90° and Z = 2. Co2As2O7 and Ni2As2O7 are dimorphic. Their high-temperature (β) polymorphs adopt the thortveitite aristotype structure in C2/m, whereas their low-temperature (α) polymorphs are hettotypes and crystallize with larger unit cells in the triclinic crystal system in space groups P\bar 1 and P1, respectively. Mn2As2O7 undergoes no phase transition and likewise adopts the thortveitite structure type in C2/m. Zn2As2O7 has an incommensurately modulated crystal structure [C2/m(α,0,γ)0s] with q = [0.3190 (1), 0, 0.3717 (1)] at ambient conditions and transforms reversibly to a commensurately modulated structure with Z = 12 (I2/c) below 273 K. The Zn phase resembles the structures and phase transitions of Cr2P2O7. Besides descriptions of the low-temperature Co2As2O7, Ni2As2O7 and Zn2As2O7 structures as five-, three- and sixfold superstructures of the thortveitite-type basic structure, the superspace approach can also be applied to descriptions of all the commensurate structures. In addition to the ternary M
2As2O7 phases, the quaternary phase (Ni,Co)2As2O7 was prepared and structurally characterized. In contrast to the previously published crystal structure of the mineral petewilliamsite, which has the same idealized formula and has been described as a 15-fold superstructure of the thortveitite-type basic structure in space group C2, synthetic (Ni,Co)2As2O7 can be considered as a solid solution adopting the α-Ni2As2O7 structure type. Differences of the two structure models for (Ni,Co)2As2O7 are discussed.
Feeding ecology of pelagic fish species in the Gulf of Riga (Baltic Sea): the importance of changes in the zooplankton community
Authors: Lankov A. , Ojaveer H. , Simm M. , Põllupüü M. , Möllmann C.
Published: November 2010

The feeding ecology of four pelagic fish species was studied in relation to their prey availability in the Gulf of Riga (Baltic Sea) during the summer 1999–2006. The zooplankton community was dominated by the cladoceran Bosmina longispina, rotifers Keratella cochlearis and K. quadrata and the copepod Eurytemora affinis, with the highest interannual variability in abundance recorded for B. longispina. The last influenced the diet of adult sprat Sprattus sprattus, juvenile smelt Osmerus eperlanus and three‐spined stickleback Gasterosteus aculeatus as these were strongly selecting for B. longispina. The fish feeding activity did not match the abundance dynamics of their preferred prey, suggesting that fishes may switch to consume other prey in case the preferred diet was limited. A considerable dietary overlap indicated high potential competition between pelagic fish species. While herring Clupea harengus membras and G. aculeatus were relying on very different food, the diets of young O. eperlanus and G. aculeatus were very similar. Interannual variability in zooplankton composition and abundance significantly affected the diet composition of fishes, but those changes were insufficient to exert a consistent influence upon fish feeding activity and total amounts of zooplankton consumed.
Alternative pre‐mRNA splicing in digestive tract malignancy
Authors: Miura Koh , Fujibuchi Wataru , Sasaki Iwao
Published: November 2010

Alternative precursor messenger RNA (pre‐mRNA) splicing plays an important role in the generation of functional diversity of the genome. The process of pre‐mRNA splicing is regulated by cis‐ and trans‐elements, and their deregulations result in aberrantly spliced individual variants and aberrant expression profiles. Accumulating evidence has revealed that aberrant splicing contributes to a number of diseases including human neoplasms. It is well known that germ line mutations in the cis‐element of tumor suppressor genes such as mismatch repair (MMR) genes, the adenomatous polyposis coli (APC) gene and the E‐cadherin (CDH1) gene are involved in Lynch syndrome, familial adenomatous polyposis and hereditary diffuse gastric cancer, respectively. In addition, somatic mutations in cis‐elements also play a role in tumorigenesis. These genetic alterations including nonsense, missense or silent mutations in cis‐elements led to aberrant transcripts by exon skipping, retention of the intron or introduction of a new splice site. The majority of erroneous transcripts with a premature termination codon are eliminated through nonsense‐mediated mRNA decay. However, it is difficult to accurately predict the resulting transcripts with current in silico strategies. Correct interpretation of genetic alterations and the investigation of aberrant transcripts are crucial for genetic diagnosis of hereditary diseases and elucidation of the molecular characteristics of neoplasms from a clinical point of view. In this review we summarize the current knowledge of the regulatory mechanism underlying alternative pre‐mRNA splicing and aberrant splicing, with particular focus on digestive tract malignancies. (Cancer Sci 2011; 102: 309–316)
Long‐term cytological and histological outcomes in women managed with loop excision treatment under local anaesthetic for high‐grade cervical intraepithelial neoplasia
Authors: Woo Y. L. , Badley C. , Jackson E. , Crawford R.
Published: November 2010

Y. L. Woo, C. Badley, E. Jackson and R. Crawford

Long‐term cytological and histological outcomes in women managed with loop excision treatment under local anaesthetic for high‐grade cervical intraepithelial neoplasia

Objective:  This study examines the impact of excision margin status after large loop excision of the transformation zone (LLETZ) under local anaesthetic for high‐grade cervical intraepithelial neoplasia (HG‐CIN) on the cytological and histological outcomes up to 5 years after treatment.

Methods:  Prospective cytological and histological data were obtained by examination of the colposcopy database at Addenbrooke’s Hospital, Cambridge, UK. All women aged between 19 and 50 years who underwent treatment for HG‐CIN by LLETZ under local anaesthetic were included in the study. Patients without follow‐up data were excluded from the study. The excision margin status was correlated with the subsequent cytological and histological outcomes.

Results:  A series of 967 women with CIN2 and CIN3 underwent LLETZ excision under local anaesthetic. Overall, 42% of women had disease present at the excision margin following LLETZ. Women with CIN3 were more likely than those with CIN2 to have an involved excision margin (P < 0.0001). Cytological recurrence was highest at 12 months (16%) and did not correlate with the CIN grade or excision margin status. Histological recurrence/persistence was also highest at 12 months follow‐up (15%) and this correlated with grade of CIN and margin status (P < 0.0001).

Conclusions:  Histological recurrence/persistence correlates with grade of CIN and excision margin status. Management of HG‐CIN in an outpatient setting under local anaesthetic is safe, cost effective and yields a favourable long‐term outcome.
Prima phacie1: a new European Food Safety Authority funded research project taking a comparative approach to pest risk assessment and methods to evaluate pest risk management options
Authors: MacLeod A. , Anderson H. , Van Der Gaag D. J. , Holt J. , Karadjova O. , Kehlenbeck H. , Labonne G. , Pruvost O. , Reynaud P. , Schrader G. , Smith J. , Steffek R. , Viaene N. , Vloutoglou I.
Published: November 2010

In late 2009, a European Food Safety Authority (EFSA)‐funded project (Prima phacie) began work to review and test methodologies for conducting pest risk assessment by means of case studies on three phytoplasmas (Candidatus Phytoplasma mali, Ca. P. prunorum, Ca. P. pyri); two bacteria (Acidovorax avenae subsp. citrulli, Xanthomonas citri [=X. axonopodis] pv. citri); two fungi (Guignardia citricarpa, Mycosphaerella dearnessii); two nematodes (Meloidogyne chitwoodi, M. fallax); and an insect (Anoplophora glabripennis). Multiple risk assessment schemes and methods will be applied to each of the case study pests, allowing for a comparative assessment of methods. Methods to assess the effectiveness of possible risk management options for each pest will also be evaluated. The project will further develop the scientific basis for pest risk assessment within the European Community and identify methodologies most suitable for conducting risk assessments and for evaluating the effectiveness of possible risk management options by the EFSA Panel on Plant Health in order to support European decision making. The project lasts 29 months, and is being conducted by an international consortium of 11 partners consisting of phytosanitary organizations, research institutes and a university. Results will be disseminated via conventional publications and at a workshop in March 2012.
The EPPO prioritization process for invasive alien plants
Authors: Brunel S. , Branquart E. , Fried G. , Van Valkenburg J. , Brundu G. , Starfinger U. , Buholzer S. , Uludag A. , Joseffson M. , Baker R.
Published: November 2010

Although invasive alien plants are gaining increased attention within EPPO countries, there is no existing widely agreed method to identify those alien plants that are considered invasive and represent the highest priority for pest risk analysis. In the framework of the ad hoc Panel on Invasive Alien Species, EPPO proposes a prioritization process for invasive alien plants designed (i) to produce a list of invasive alien plants that are established or could potentially establish in the EPPO region and (ii) to determine which of these have the highest priority for an EPPO pest risk analysis. The process consists of compiling available information on alien plants according to pre‐determined criteria, and can be run at the EPPO region level, or at a country or local area level. These criteria examine whether the species is alien in the area under study, and whether it is established or not. The criteria used primarily rely on observations in the EPPO region but, if the species is not established, the invasive behaviour of the species in other countries should be investigated, as well as the suitability of the ecoclimatic conditions in the area under consideration. The spread potential, the potential negative impacts on native species, habitats and ecosystems, as well as on agriculture, horticulture or forestry are considered. If the species qualifies as an invasive alien plant of major concern through this first set of questions, the process then investigates the efficiency of international measures (to be justified through a pest risk analysis) to prevent the entry and spread of the species. The second set of questions are designed to determine whether the species is internationally traded or enters new countries through international pathways for which the risk of introduction is superior to natural spread, and whether the species still has a significant suitable area for further spread. If used by several EPPO countries, this prioritization process represents an opportunity to provide consistent country lists of invasive alien plant species, as well as a tool for dialogue and exchange of information.
Soil biodiversity and carbon cycling: a review and synthesis of studies examining diversity–function relationships
Authors: Nielsen U. N. , Ayres E. , Wall D. H. , Bardgett R. D.
Published: November 2010

Biodiversity and carbon (C) cycling have been the focus of much research in recent decades, partly because both change as a result of anthropogenic activities that are likely to continue. Soils are extremely species‐rich and store approximately 80% of global terrestrial C. Soil organisms play a key role in C dynamics and a loss of species through global changes could influence global C dynamics. Here, we synthesize findings from published studies that have manipulated soil species richness and measured the response in terms of ecosystem functions related to C cycling (such as decomposition, respiration and the abundance or biomass of decomposer biota) to evaluate the impact of biodiversity loss on C dynamics. We grouped studies where one or more biotic groups had been manipulated to include a richness of ≤10 species or >10 species in order to reflect ‘low’ and ‘high’ extents of diversity manipulations. There was a positive relationship between species richness and C cycling in 77–100% of low‐diversity experiments, even when the richness of just one biotic group was manipulated, whereas positive relationships occurred less frequently in studies with greater richness (35–64%). Moreover, when positive relationships were observed, these often indicated functional redundancy at low extents of diversity or that community composition had a stronger influence on C cycling than did species richness. Initial reductions in soil species richness resulting from global changes are unlikely to alter C dynamics significantly unless particularly influential species are lost. However, changes in community composition, and the loss of species with an ability to facilitate specialized soil processes related to C cycling, as a result of global changes, may have larger impacts on C dynamics.
Vulnerability in homeless adolescents: concept analysis
Authors: Dorsen Caroline
Published: November 2010

dorsen c. (2010) Vulnerability in homeless adolescents: concept analysis.Journal of Advanced Nursing66(12), 2819–2827.

Aim. This paper is a report of an analysis of the concept of vulnerability in homeless adolescents.

Background. Caring for vulnerable populations and reduction of health inequities are top international healthcare priorities. Homeless adolescents experience health disparities as compared to their housed counterparts and are among the most vulnerable of all populations. Understanding the concept of vulnerability as it relates to the homeless adolescent population will assist nurses in addressing the health and social concerns of this population.

Data sources. The PubMed, Medline, Cochrane and CINAHL electronic databases were used to search for research papers published between 1980 and 2009. The keywords ‘vulnerable’, ‘vulnerability’ and ‘homeless’, ‘adolescent’, ‘street’ and ‘youth’ were used. Twenty‐three papers from multiple disciplines were reviewed in an effort to arrive at a global definition of homeless adolescents’ vulnerability.

Method. Rodgers’ evolutionary method of concept analysis was used for the analysis.

Results. Based on this analysis, vulnerability in homeless adolescents is defined as the constellation of past, present and future risk, perceived or real, because of the common human experience of risk, the increased vulnerability of the adolescent period, the consequences of family disruption, and the increased risks of life on the street.

Conclusion. There was agreement in the literature regarding the antecedents, attributes, consequences and surrogate terms of the concept. However, differentiation between the concepts of risk and vulnerability, as suggested by seminal nurse researchers, was not supported. More research is needed into self‐perceptions of vulnerability and vulnerability in subgroups of homeless adolescents.