bluuebunny/crossref_metadata_2025 huggingface dataset:
High-field electron transport of wide quantum wells under in-plane magnetic fields
Authors: Guo X. G. , Cao J. C.
Published: June 2009

High-field transport properties of a bilayer two-dimensional electron gas in a wide quantum well (QW) subjected to an in-plane magnetic field have been investigated by ensemble Monte Carlo simulations. The electron energy spectrum was calculated self-consistently. Due to the effect of Hartree potential, a coupled two-dimensional electron gas appears in the wide QW. The in-plane magnetic field induces significant modifications in bonding and antibonding subbands of the QW. The high-field transport behavior is significantly different from the low-field case. With increasing the magnetic field, the high-field drift velocity increases to its maximum value and then decreases monotonically. The magnetic-field-dependent behavior of drift velocity is qualitatively explained as the competition between the magnetic-field-induced depopulation of the antibonding subband and the electron effective mass enhancement.
Modeling of the dielectric relaxation in eukaryotic cells
Authors: Salou P. , Mejdoubi A. , Brosseau C.
Published: June 2009

There are two major objectives to the present work. The first objective is to study the influence of the frequency of the oscillating electrical field and membrane conductivity on the dielectric relaxation (β-dispersion resulting from the buildup of charge at cell membranes due to the Maxwell–Wagner–Sillars interfacial polarization) of simple core-shell structural models of biological cells. The characteristic frequency, relaxation strength, and effective conductivity are explicitly computed, via finite element simulations, as a function of surface fraction of inclusion and shape. The second objective of this work is to determine the electric potential distribution inside and outside several cell models and comment on the relevance of these numerical expectations to many aspects of cellular transformation.
Two paralleled Ba0.25Sr0.75TiO3 ferroelectric varactors series connected coplanar waveguide microwave phase shifter
Authors: Sheng Su , Wang Peng , Chen Xin , Zhang Xiao-Yu , Ong C. K.
Published: June 2009

A distributed phase shifter of coplanar waveguide (CPW) using ferroelectric (Ba0.25Sr0.75TiO3) film varactors with parallel-plate electrodes is presented. In order to satisfy the requirement of small dimension of the parallel-plate varactor for the design of phase shifter and impedance match of the circuit, two parallel-plate varactors of 8×10 μm2 are connected in series. The fabricated CPW phase shifter exhibited low insertion loss of 2.3 dB and large differential phase shift of 170° at 7 GHz with a dc bias voltage of 25 V.
Oblique modulation of ion-acoustic waves and envelope solitons in electron-positron-ion plasma
Authors: Jehan Nusrat , Salahuddin M. , Mirza Arshad M.
Published: June 2009

The effect of oblique modulation on the amplitude dynamics of ion-acoustic wave propagating in a collisionless electron-positron-ion plasma is investigated. Using Krylov–Bogoliubov–Mitropolsky (KBM) perturbation method, a nonlinear Schrödinger (NLS) equation is derived which governs the evolution of obliquely modulated ion-acoustic envelope excitations. It is found that the presence of positron component significantly modifies the stability domains for small angles of propagation with the direction of modulation. The stationary solutions of NLS equation, i.e., bright and dark envelope solitons, become narrower as the concentration of positron component increases.
Thermocapillary instability of a liquid layer under heat flux modulation
Authors: Smorodin B. L. , Mikishev A. B. , Nepomnyashchy A. A. , Myznikova B. I.
Published: June 2009

The parametric excitation of the Marangoni instability in a horizontal liquid layer is analyzed in the case of a heat flux periodically varying at the deformable interface. Two response modes of the convective system to an external periodic stimulation, synchronous and subharmonic ones, have been found. The cellular and long-wave instability thresholds are compared. The neutral stability curves are presented for a variety of external conditions. It is shown that contrary to the classical parametric resonance, the synchronous disturbances may become most dangerous for the stability of the base state, and the long-wave mode may cause the instability prior to the cellular mode within a definite range of parameters.
Justice Incomplete: Radovan Karadžić, the ICTY, and the Spaces of International Law
Authors: Jeffrey Alex
Published: June 2009

The arrest of Radovan Karadžić in July 2008 and his transfer to the International Criminal Tribunal for the former Yugoslavia (ICTY) has brought international judicial instruments under renewed scrutiny. In particular, the active pursuit of indicted war criminals across the international borders of the former Yugoslavia has challenged the primacy of the state as the locus of judicial authority. Using the arrest of Radovan Karadžić as a starting point, this paper evaluates the emergence of the ICTY and its contribution to peace building in the former Yugoslavia. It suggests that the ICTY is challenging existing international interventions within Bosnia—in particular, the 1995 Dayton Peace Agreement—whilst simultaneously producing new judicial spaces and encounters. The paper calls for an understanding of international justice not as an abstract condition or outcome, but as a process that is incomplete and situated in space.
Form and Formlessness: The Spatiocorporeal Politics of the American Kennel Club
Authors: Lulka David
Published: June 2009

This paper merges together the growing theoretical interest in nonhumans with longstanding philosophical questions about form in order to assess the political and ethical ramifications of contemporary human engagements with domestic dogs. In particular, this paper explores the organ-izational and legal activities of the American Kennel Club (AKC) to highlight the importance of form in their political engagements and to illustrate some of the unintended consequences these activities produce. Although the AKC attempts to instantiate its own vision of the ideal dog, the organization is incapable of solidifying the character of the domestic dog, for it must contend with other groups (animal welfare groups, dogfighters, governmental agencies, and dogs themselves) which have different visions of the ideal dog. To accentuate and counteract these failings, formlessness is utilized here as a tool and as a normative ethic to reconsider the nature of human–nonhuman relations. Dogs are an ideal subject for such an investigation because they exist in many different forms that are themselves susceptible to considerable change. Yet the specific findings described here should be applicable to a wide range of natural phenomena since the interplay between form and formlessness is generally pervasive throughout the world.
Phylogenetic relationships within Philodromidae, with a taxonomic revision of Philodromus subgenus Artanes in the western Palearctic (Arachnida:Araneae)
Authors: Muster Christoph
Published: June 2009

The first quantitative phylogenetic analysis within the spider family Philodromidae (using 65 morphological characters from 40 ingroup taxa) does not corroborate Schick’s division into the tribes Thanatini (Apollophanes O. P.-Cambridge, 1898, Pelloctanes Schick, 1965, Thanatus C. L. Koch, 1837; Tibellus, Simon, 1875) and Philodromini (Ebo Keyserling, 1884, Philodromus Walckenaer, 1826; Rhysodromus Schick, 1965). Instead, Ebo is sister to all other genera in the family, and a fraction of Philodromus (the histrio species-group = Rhysodromus Schick) are contained with the Thanatini. The forgotten genus Artanes Thorell, 1870 constitutes a well-defined distal taxon in a clade that contains the majority of Philodromus species. Here Artanes is considered a subgenus of Philodromus, and includes the margaritatus and the poecilus species-groups. The western Palearctic species of the subgenus are revised. Twelve species are (re-)described, keyed and illustrated: Philodromus blanckei (Wunderlich, 1995) (first description of ♀); P. calidus Lucas, 1846; P. femurostriatus, sp. nov. from the eastern Mediterranean; P. fuscomarginatus (De Geer, 1778); P. johani, sp. nov. from Crete; P. laricium Simon, 1875, removed from synonymy with P. corticinus (C. L. Koch); P. maghrebi, sp. nov. from northern Africa (♀ only); P. margaritatus (Clerck, 1757); P. parietalis Simon, 1875; P. pentheri, sp. nov. from the Caspian region and Albania (♀ only); P. pinetorum, sp. nov. from the Mediterranean; and P. poecilus (Thorell, 1872).
Evaluation of a geriatric day rehabilitation centre: subjective and objective outcomes in community-dwelling older adults
Authors: Foley A. , Hillier S. , Barnard R.
Published: June 2009

Pre and post testing were conducted on community-dwelling older adults referred to a geriatric day rehabilitation centre (DRC). Consecutive DRC clients were screened for inclusion over a 16-month period and were eligible if: aged 60+ years; cognitively intact; and reason for referral involved spinal or lower limb musculoskeletal impairment, disability or surgery, and/or reduced functional mobility or falls. Clients were excluded if they had a neurological disorder, or did not complete the program. Outcome measures included: lower limb strength; balance; mobility; self-reported pain; activities of daily living; and quality of life. Data were summarised using descriptive statistics and analysed using paired t-tests. Of the 137 participants recruited, 110 were female and the mean age was 79.5 ± 7.3 years. In total, 106 participants completed the DRC program and were assessed at baseline and re-assessed at discharge. The mean length of stay was 12.4 ± 2.9 weeks, with 21.4 ± 5.4 attendances. From baseline to discharge, statistically significant differences were found for all objective measures of physical functioning, balance, and for all lower limb strength tests (P < 0.0001). Glasgow Pain Questionnaire scores demonstrated statistically significant improvements in all five domains of the scale (P < 0.0001). The Barthel Index and Multi-dimensional Functional Assessment Questionnaire both showed a statistically significant improvement in the level of independence in activities of daily living (ADL) (P < 0.05). The Assessment of Quality of Life Questionnaire showed a statistically significant improvement (P = 0.027). The Exercise Benefits/Barriers Scale also showed a statistically significant improvement over DRC attendance (P = 0.005). The Falls Efficacy Scale showed a positive change, but the improvement was not statistically significant (P = 0.80). The study’s results indicate that community-dwelling older adults with physical disabilities and multiple comorbidities who attended the interdisciplinary geriatric DRC, significantly improved their lower limb strength, balance and physical function, and also showed significant decreases in self-reported pain, and improvements in independence in ADL and quality of life. Given the limitations of the current study, further research, in the form of high quality studies with larger sample sizes that involve direct comparisons with other forms of care or against a control group, is needed to determine whether day rehabilitation centre programs provide the optimum mode of rehabilitation for this population in the most cost effective manner.
Kinase activity-independent regulation of cyclin pathway by GRK2 is essential for zebrafish early development
Authors: Jiang Xi , Yang Peng , Ma Lan
Published: June 2009

G protein-coupled receptor (GPCR) kinases (GRKs) are known as a family of serine/threonine kinases that function as key regulators of GPCRs, as well as other types of receptors. Extensive studies of GRKs at the cellular and organismal levels have led to a consensus that GRK-catalyzed phosphorylation of receptors is the primary mechanism underlying their physiological functions. Here, we report that down-regulation of GRK2 in zebrafish embryos with GRK2 morpholino results in developmental early arrest and, interestingly, that this arrest can be rescued by exogenous expression of a GRK2 kinase-dead mutant, K220R. A physical interaction between GRK2 and cyclin B1 regulator patched homolog 1 (PTCH1), stimulated by Hedgehog (Hh), rather than GRK2-mediated phosphorylation of downstream targets, appears as the underlying mechanism. We identify residues 262–379 as the PTCH1-binding region (BP). Interaction of GRK2, K220R, and BP with PTCH1 reduces the association of PTCH1 with cyclin B1 and disrupts PTCH1-mediated inhibition of cyclin B1 nuclear translocation, whereas the PTCH1-binding deficient GRK2 mutant (Δ312–379) does not. Cell cycle and cell proliferation assays show that overexpressing PTCH1 remarkably inhibited cell growth and this effect could be attenuated by GRK2, K220R, or BP, but not Δ312–379. In vivo studies show that BP, as well as the nuclear-localizing cyclin B1 mutant, is effective in rescuing the early arrest phenotype in GRK2 knockdown embryos, but Δ312–379 is not. Our data thus reveal a novel kinase activity-independent function for GRK and establish a role for GRK2 as a cell-cycle regulator during early embryonic development.
Physicochemical principles that regulate the competition between functional and dysfunctional association of proteins
Authors: Pechmann Sebastian , Levy Emmanuel D. , Tartaglia Gian Gaetano , Vendruscolo Michele
Published: June 2009

To maintain protein homeostasis, a variety of quality control mechanisms, such as the unfolded protein response and the heat shock response, enable proteins to fold and to assemble into functional complexes while avoiding the formation of aberrant and potentially harmful aggregates. We show here that a complementary contribution to the regulation of the interactions between proteins is provided by the physicochemical properties of their amino acid sequences. The results of a systematic analysis of the protein–protein complexes in the Protein Data Bank (PDB) show that interface regions are more prone to aggregate than other surface regions, indicating that many of the interactions that promote the formation of functional complexes, including hydrophobic and electrostatic forces, can potentially also cause abnormal intermolecular association. We also show, however, that aggregation-prone interfaces are prevented from triggering uncontrolled assembly by being stabilized into their functional conformations by disulfide bonds and salt bridges. These results indicate that functional and dysfunctional association of proteins are promoted by similar forces but also that they are closely regulated by the presence of specific interactions that stabilize native states.
γ-Actin is required for cytoskeletal maintenance but not development
Authors: Belyantseva Inna A. , Perrin Benjamin J. , Sonnemann Kevin J. , Zhu Mei , Stepanyan Ruben , McGee JoAnn , Frolenkov Gregory I. , Walsh Edward J. , Friderici Karen H. , Friedman Thomas B. , Ervasti James M.
Published: June 2009

β
cyto
-Actin and γ
cyto
-actin are ubiquitous proteins thought to be essential building blocks of the cytoskeleton in all non-muscle cells. Despite this widely held supposition, we show that γ
cyto
-actin null mice (
Actg1
−/−
) are viable. However, they suffer increased mortality and show progressive hearing loss during adulthood despite compensatory up-regulation of β
cyto
-actin. The surprising viability and normal hearing of young
Actg1
−/−
mice means that β
cyto
-actin can likely build all essential non-muscle actin-based cytoskeletal structures including mechanosensory stereocilia of hair cells that are necessary for hearing. Although γ
cyto
-actin–deficient stereocilia form normally, we found that they cannot maintain the integrity of the stereocilia actin core. In the wild-type, γ
cyto
-actin localizes along the length of stereocilia but re-distributes to sites of F-actin core disruptions resulting from animal exposure to damaging noise. In
Actg1
−/−
stereocilia similar disruptions are observed even without noise exposure. We conclude that γ
cyto
-actin is required for reinforcement and long-term stability of F-actin–based structures but is not an essential building block of the developing cytoskeleton.
Olfactory neural circuitry for attraction to amino acids revealed by transposon-mediated gene trap approach in zebrafish
Authors: Koide Tetsuya , Miyasaka Nobuhiko , Morimoto Kozo , Asakawa Kazuhide , Urasaki Akihiro , Kawakami Koichi , Yoshihara Yoshihiro
Published: June 2009

In fish, amino acids are food-related important olfactory cues to elicit an attractive response. However, the neural circuit underlying this olfactory behavior is not fully elucidated. In the present study, we applied the
Tol2
transposon-mediated gene trap method to dissect the zebrafish olfactory system genetically. Four zebrafish lines (SAGFF27A, SAGFF91B, SAGFF179A, and SAGFF228C) were established in which the modified transcription activator Gal4FF was expressed in distinct subsets of olfactory sensory neurons (OSNs). The OSNs in individual lines projected axons to partially overlapping but mostly different glomeruli in the olfactory bulb (OB). In SAGFF27A, Gal4FF was expressed predominantly in microvillous OSNs innervating the lateral glomerular cluster that corresponded to the amino acid-responsive region in the OB. To clarify the olfactory neural pathway mediating the feeding behavior, we genetically expressed tetanus neurotoxin in the Gal4FF lines to block synaptic transmission in distinct populations of glomeruli and examined their behavioral response to amino acids. The attractive response to amino acids was abolished only in SAGFF27A fish carrying the tetanus neurotoxin transgene. These findings clearly demonstrate the functional significance of the microvillous OSNs innervating the lateral glomerular cluster in the amino acid-mediated feeding behavior of zebrafish. Thus, the integrated approach combining genetic, neuroanatomical, and behavioral methods enables us to elucidate the neural circuit mechanism underlying various olfactory behaviors in adult zebrafish.
Optimal neuroprotection by erythropoietin requires elevated expression of its receptor in neurons
Authors: Sanchez Pascal E. , Fares Raafat P. , Risso Jean-Jacques , Bonnet Chantal , Bouvard Sandrine , Le-Cavorsin Marion , Georges Béatrice , Moulin Colette , Belmeguenai Amor , Bodennec Jacques , Morales Anne , Pequignot Jean-Marc , Baulieu Etienne-Emile , Levine Robert A. , Bezin Laurent
Published: June 2009

Erythropoietin receptor (EpoR) binding mediates neuroprotection by endogenous Epo or by exogenous recombinant human (rh)Epo. The level of
EpoR
gene expression may determine tissue responsiveness to Epo. Thus, harnessing the neuroprotective power of Epo requires an understanding of the Epo–EpoR system and its regulation. We tested the hypothesis that neuronal expression of EpoR is required to achieve optimal neuroprotection by Epo. The ventral limbic region (VLR) in the rat brain was used because we determined that its neurons express minimal EpoR under basal conditions, and they are highly sensitive to excitotoxic damage, such as occurs with pilocarpine-induced status epilepticus (Pilo-SE). We report that (
i
) EpoR expression is significantly elevated in nearly all VLR neurons when rats are subjected to 3 moderate hypoxic exposures, with each separated by a 4-day interval; (
ii
) synergistic induction of EpoR expression is achieved in the dorsal hippocampus and neocortex by the combination of hypoxia and exposure to an enriched environment, with minimal increased expression by either treatment alone; and (
iii
) rhEpo administered after Pilo-SE cannot rescue neurons in the VLR, unless neuronal induction of EpoR is elicited by hypoxia before Pilo-SE. This study thus demonstrates using environmental manipulations in normal rodents, the strict requirement for induction of EpoR expression in brain neurons to achieve optimal neuroprotection. Our results indicate that regulation of
EpoR
gene expression may facilitate the neuroprotective potential of rhEpo.
Dynamic histone H3 epigenome marking during the intraerythrocytic cycle ofPlasmodium falciparum
Authors: Salcedo-Amaya Adriana M. , van Driel Marc A. , Alako Blaise T. , Trelle Morten B. , van den Elzen Antonia M. G. , Cohen Adrian M. , Janssen-Megens Eva M. , van de Vegte-Bolmer Marga , Selzer Rebecca R. , Iniguez A. Leonardo , Green Roland D. , Sauerwein Robert W. , Jensen Ole N. , Stunnenberg Hendrik G.
Published: June 2009

Epigenome profiling has led to the paradigm that promoters of active genes are decorated with H3K4me3 and H3K9ac marks. To explore the epigenome ofPlasmodium falciparumasexual stages, we performed MS analysis of histone modifications and found a general preponderance of H3/H4 acetylation and H3K4me3. ChIP-on-chip profiling of H3, H3K4me3, H3K9me3, and H3K9ac from asynchronous parasites revealed an extensively euchromatic epigenome with heterochromatin restricted to variant surface antigen gene families (VSA) and a number of genes hitherto unlinked to VSA. Remarkably, the vast majority of the genome shows an unexpected pattern of enrichment of H3K4me3 and H3K9ac. Analysis of synchronized parasites revealed significant developmental stage specificity of the epigenome. In rings, H3K4me3 and H3K9ac are homogenous across the genes marking active and inactive genes equally, whereas in schizonts, they are enriched at the 5′ end of active genes. This study reveals an unforeseen and unique plasticity in the use of the epigenetic marks and implies the presence of distinct epigenetic pathways in gene silencing/activation throughout the erythrocytic cycle.
Requirement for AHNAK1-mediated calcium signaling during T lymphocyte cytolysis
Authors: Matza Didi , Badou Abdallah , Jha Mithilesh K. , Willinger Tim , Antov Andrey , Sanjabi Shomyseh , Kobayashi Koichi S. , Marchesi Vincent T. , Flavell Richard A.
Published: June 2009

Cytolytic CD8+T cells (CTLs) kill virally infected cells, tumor cells, or other potentially autoreactive T cells in a calcium-dependent manner. To date, the molecular mechanism that leads to calcium intake during CTL differentiation and function has remained unresolved. We demonstrate that desmoyokin (AHNAK1) is expressed in mature CTLs, but not in naive CD8+T cells, and is critical for calcium entry required for their proper function during immune response. We show that mature AHNAK1-deficient CTLs exhibit reduced Cav1.1 α1 subunit expression (also referred to as L-type calcium channels or α1S pore-forming subunits), which recently were suggested to play a role in calcium entry into CD4+T cells. AHNAK1-deficient CTLs show marked reduction in granzyme-B production, cytolytic activity, and IFN-γ secretion after T cell receptor stimulation. Our results demonstrate an AHNAK1-dependent mechanism controlling calcium entry during CTL effector function.
Integrin β
1
-focal adhesion kinase signaling directs the proliferation of metastatic cancer cells disseminated in the lungs
Authors: Shibue Tsukasa , Weinberg Robert A.
Published: June 2009

The development of metastases is an extended and inefficient process involving multiple steps. The last of these involves the growth of micrometastases into macroscopic tumors. We show here that intravenously injected, nonmetastatic cancer cells cease proliferating after extravasating into the parenchyma of the lungs; this response is attributable to the cells inability to trigger adhesion-related signaling events when they are scattered sparsely within the extracellular matrix (ECM) of the parenchyma. We recapitulate this situation by culturing these nonmetastatic cells at low seeding density in ECM-derived gels in vitro, in which they undergo cell-cycle arrest resulting, in part, from insufficient activation of focal adhesion kinase (FAK). Metastatic cancer cells, in contrast, show sufficient FAK activation to enable their proliferation within ECM gels in vitro and continue cell-cycle progression within the lung parenchyma in vivo. Activation of FAK in these metastatic cells depends on expression of the β
1
subunit of integrins, and proliferation of these cells after extravasation in the lungs is diminished by knocking down the expression of either FAK or integrin β
1
. These results demonstrate the critical role of integrin β
1
-FAK signaling axis in controlling the initial proliferation of micrometastatic cancer cells disseminated in the lungs.
Using stimulated recall to investigate pupils' thinking about online bilingual communication: Code‐switching and pronominal address in L2 French
Authors: Evans Michael
Published: June 2009

This article demonstrates how evidence related to performance in computer mediated communication (CMC) can be used as a vehicle for researching pupils' thinking about using and learning a foreign language. The analysis is based on a qualitative study of pupils from two contrasting schools who had taken part in a multinational CMC project involving learners of French and English as a foreign language. The analysis focuses on the pupils' explanations and intuitions about their decisions with regard to two areas of their interaction in particular: code‐switching and pronominal address. The findings suggest that the English learners of French had an implicit set of communicative priorities in which interpersonal objectives tended to dominate over ideational objectives. Evidence from the study indicates the need for further research‐informed educational development in two areas: a reappraisal of the framework for foreign language teaching in England on the basis of greater emphasis on second language (L2) use within the framework; and more developed theoretical understanding of pupil cognition in relation to foreign language learning.
Book Reviews
Authors: Kiviniemi Vesa
Published: June 2009

Dynamic Brain Imaging: Multi-Modal Methods and In Vivo Applications. Edited by F. Hyder. Totowa, NJ: Humana Press/Springer, 2009. ISBN: 978-1-934115-74-9. 366 pages, 107 illustrations. Price (hardcover): USD 99.00, EUR 66.95
Motion coordination affects movement parameters in a joint pick-and-place task
Authors: Vesper Cordula , Soutschek Alexander , Schubö Anna
Published: June 2009

This study examined influences of social context on movement parameters in a pick-and-place task. Participants’ motion trajectories were recorded while they performed sequences of natural movements either working side-by-side with a partner or alone. It was expected that movement parameters would be specifically adapted to the joint condition to overcome the difficulties arising from the requirement to coordinate with another person. To disentangle effects based on participants’ effort to coordinate their movements from effects merely due to the other's presence, a condition was included where only one person performed the task while being observed by the partner. Results indicate that participants adapted their movements temporally and spatially to the joint action situation: Overall movement duration was shorter, and mean and maximum velocity was higher when actually working together than when working alone. Pick-to-place trajectories were also shifted away from the partner in spatial coordinates. The partner's presence as such did not have an impact on movement parameters. These findings are interpreted as evidence for the use of implicit strategies to facilitate movement coordination in joint action tasks.
Topical Therapy for Methicillin-Resistant Staphylococcus aureus Colonization Impact on Infection Risk
Authors: Robicsek Ari , Beaumont Jennifer L. , Thomson Richard B. , Govindarajan Geetha , Peterson Lance R.
Published: June 2009

Objective.

We evaluated the usefulness of topical decolonization therapy for reducing the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection among MRSA-colonized inpatients.

Design.

Retrospective cohort study.

Setting and Intervention.

Three hospitals with universal surveillance for MRSA; at their physician's discretion, colonized patients could be treated with a 5-day course of nasal mupirocin calcium 2%, twice daily, plus Chlorhexidine gluconate 4% every second day.

Patients and Methods.

MRSA carriers were later retested for colonization (407 subjects; study 1) or followed up for development of MRSA infection (933 subjects; study 2). Multivariable methods were used to determine the impact of decolonization therapy on the risks of sustained colonization (in study 1) and MRSA infection (in study 2).

Results.

Independent risk factors for sustained colonization included residence in a long-term care facility (odds ratio [OR], 1.8 [95% confidence interval {CI}, 1.1–3.2]) and a pressure ulcer (OR, 2.3 195% CI, 1.2–4.4]). Mupirocin at any dose decreased this risk, particularly during the 30-60-day period after therapy; mupirocin resistance increased this risk (OR, 4.1 [95% CI, 1.6–10.7]). Over a median follow-up duration of 269 days, 69 (7.4%) of 933 patients developed infection. Independent risk factors for infection were length of stay (hazard ratio [HR], 1.2 per 5 additional days [95% CI, 1.0–1.4]), chronic lung disease (HR, 1.7 [95% CI, 1.0–2.8]), and receipt of non-MRSA-active systemic antimicrobial agents (HR, 1.8 [95% CI, 1.1–3.1]). Receipt of mupirocin did not affect the risk of infection, although there was a trend toward delayed infection among patients receiving mupirocin (median time to infection, 50 vs 15.5 days; P = .06).

Conclusions.

Mupirocin-based decolonization therapy temporarily reduced the risk of continued colonization but did not decrease the risk of subsequent infection.
Microbiological Efficacy and Tolerability of a New, Non-Alcohol-Based Hand Disinfectant
Authors: Agthe Niina , Terho Kirsi , Kurvinen Tiina , Routamaa Marianne , Peltonen Reijo , Laitinen Kirsi , Kanerva Mari
Published: June 2009

Objective.

Alcohol-based hand disinfectants are widely used in hospitals. Occasionally, there is a need for non-alcohol-based products, but alternatives have been scarce. We studied the microbiological efficacy and tolerability of a water-based hand disinfectant for healthcare workers.

Design.

A water-based hand disinfectant was introduced as the only hand disinfectant in 5 wards in Turku University Hospital, Finland. Ninety-nine healthcare workers participated in fingerprint sampling during the 7-week study period. In another ward, 26 healthcare workers who were using alcohol-based hand disinfectant acted as control subjects for the skin reaction studies. The water-based product was tested in the laboratory according to the European standard EN 12791. We obtained 292 fingerprint samples before disinfection and 302 after disinfection. The opinions of healthcare workers were collected by use of a questionnaire, and skin reactions were assessed subjectively by use of questionnaires and objectively by measuring moisture and transepidermal water loss.

Results.

When tested in accordance with the European standard, the product met the requirements for short-term and long-term efficacy. The results of the fingerprint test showed that there was a statistically significant decrease in colonization of the fingertips before and after disinfection (P < .001).

The users of the water-based hand disinfectant reported dry skin more often than did control subjects, but visual inspection and the results of the moisture measurement showed no difference between the users of the water-based hand disinfectant and the control subjects. Transepidermal water loss measurement also showed no deterioration of skin condition.

Conclusions.

The water-based hand disinfectant was shown to be an effective hand disinfectant that caused relatively little skin irritation and can serve as a hand hygiene alternative in situations in which alcohol-based disinfectant cannot be used.
Likelihood of Inadequate Treatment A Novel Approach to Evaluating Drug-Resistance Patterns
Authors: Burgmann Heinz , Stoiser Brigitte , Heinz Gottfried , Schenk Peter , Apfalter Petra , Zedtwitz-Liebenstein Konstantin , Frass Michael , Carmeli Yehuda
Published: June 2009

Objective.

To provide a novel way to predict the likelihood that antibiotic therapy will result in prompt, adequate therapy on the basis of local microbiological data.

Design and Setting.

Prospective study conducted at 3 medical intensive care units at the Viennese General Hospital, a tertiary care medical university teaching hospital in Vienna, Austria.

Patients.

One hundred one patients who received mechanical ventilation and who met the criteria for having ventilator-associated pneumonia.

Design.

Fiberoptic bronchoscopic examination was performed, and bronchoalveolar samples were collected. Samples were analyzed immediately by a single technician. Minimum inhibitory concentrations were determined for imipenem, cephalosporins (cefepime and cefpirome), ciprofloxacin, and piperacillin-tazobactam, and drug resistance rates were calculated. These drug resistance rates were translated into the likelihood of inadequate therapy (LIT; the frequency of inadequately treated patients per antibiotic and drug-resistant strain), cumulative LIT (the cumulative frequency of inadequately treated patients), and syndrome-specific LIT.

Results.

Amongthe 101 bronchoalveolar samples, culture yielded significant (at least 1 × 104 colony-forming units per raL) polymicrobial findings for 34 and significant monomicrobial findings for 31; 36 culture results were negative. Of the isolates from patients with ventilator-associated pneumonia who had monomicrobial culture findings, 33% were gram-positive bacteria and 20% were gram-negative bacteria. LIT suggested that 1 of 2 patients was treated inadequately for Pseudomonas aeruginosa infection. The LIT for patients with ventilator-associated pneumonia revealed that the rank order of antibiotics for appropriate therapy was (1) imipenem, (2) cephalosporins, (3) ciprofloxacin, and (4) piperacillin-tazobactam. These calculations were based solely on microbiological data.

Conclusions.

The novel ratio LIT may help clinicians use microbiological data on drug resistance to predict which antimicrobial agents will provide adequate therapy. In daily practice, this new approach may be helpful for choosing adequate antimicrobial therapy.
Tuberculin Skin Tests Among Medical Students With Prior Bacille-Calmette Guérin Vaccination in a Setting With a High Prevalence of Tuberculosis
Authors: Khawcharoenporn Thana , Apisarnthanarak Anucha , Thongphubeth Kanokporn , Yuekyen Chananart , Mundy Linda M.
Published: June 2009

Presence of a bacille Calmette-Guérin vaccination scar in medical students was an independent factor associated with initial tuberculin skin test reactions of 10–19 mm (P = .03) and booster effects of 6–9 mm (P = .02). These findings suggest that an initial tuberculin skin test reaction of at least 20 mm or a booster effect of at least 10 mm will reveal tuberculosis among students with prior bacille Calmette-Guérin vaccination.
Bioactivity of the Murex Homeopathic Remedy and of Extracts from an Australian Muricid Mollusc against Human Cancer Cells
Authors: Benkendorff Kirsten , McIver Cassandra M. , Abbott Catherine A.
Published: June 2009

Marine molluscs from the family Muricidae are the source of a homeopathic remedy Murex, which is used to treat a range of conditions, including cancer. The aim of this study was to evaluate the in vitro bioactivity of egg mass extracts of the Australian muricid Dicathais orbita, in comparison to the Murex remedy, against human carcinoma and lymphoma cells. Liquid chromatography coupled with mass spectrometry (LC‐MS) was used to characterize the chemical composition of the extracts and homeopathic remedy, focusing on biologically active brominated indoles. The MTS (tetrazolium salt) colorimetric assay was used to determine effects on cell viability, while necrosis and apoptosis induction were investigated using flow cytometry (propidium iodide and Annexin‐V staining, resp.). Cells were treated with varying concentrations (1–0.01 mg/mL) of crude and semi‐purified extracts or preparations (dilute 1 M and concentrated 4 mg/mL) from the Murex remedy (4 h). The Murex remedy showed little biological activity against the majority of cell lines tested. In contrast, the D. orbita egg extracts significantly decreased cell viability in the majority of carcinoma cell lines. Flow cytometry revealed these extracts induce necrosis in HT29 colorectal cancer cells, whereas apoptosis was induced in Jurkat cells. These findings highlight the biomedical potential of Muricidae extracts in the development of a natural therapy for the treatment of neoplastic tumors and lymphomas.
Relationship between renal function and serum cardiac troponin T in patients with chronic heart failure
Authors: Tsutamoto Takayoshi , Kawahara Chiho , Yamaji Masayuki , Nishiyama Keizo , Fujii Masanori , Yamamoto Takashi , Horie Minoru
Published: June 2009

Aims

Both serum cardiac troponin T (cTnT) and renal function are prognostic predictors in patients with chronic heart failure (CHF). We aimed to evaluate the relationship between renal function and serum cTnT.

Methods and results

We measured serum concentrations of cTnT in the aortic root (AO) and coronary sinus (CS) in 258 CHF patients. Patients were divided into two groups: patients with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2 [chronic kidney disease (CKD)(−)], and patients with an eGFR < 60 mL/min/1.73 m2 [CKD (+)]. In 32 (12%) of the 258 CHF patients, serum levels of cTnT were detectable (≥0.03 ng/mL) in the AO and in the CS. There was no correlation between eGFR and the transcardiac increase in cTnT and there was a significant negative correlation between eGFR and the serum cTnT concentration (r = − 0.365, P = 0.039). There was no difference in the transcardiac gradient of cTnT between patients without CKD (n = 16) and patients with CKD (n = 16) (0.083 ± 0.11 vs. 0.108 ± 0.13 ng/mL, P = 0.55). However, the serum cTnT level in the AO was two‐fold higher in CHF patients with CKD than patients without CKD (0.20 ± 0.177 vs. 0.088 ± 0.065 ng/mL, P < 0.05).

Conclusion

These findings indicate that decreased clearance via the kidney contributes to the elevated cTnT in CHF patients with CKD.
Plasticity in probabilistic reaction norms for maturation in a salmonid fish
Authors: Morita Kentaro , Tsuboi Jun-ichi , Nagasawa Toru
Published: June 2009

The relationship between body size and the probability of maturing, often referred to as the probabilistic maturation reaction norm (PMRN), has been increasingly used to infer genetic variation in maturation schedule. Despite this trend, few studies have directly evaluated plasticity in the PMRN. A transplant experiment using white-spotted charr demonstrated that the PMRN for precocious males exhibited plasticity. A smaller threshold size at maturity occurred in charr inhabiting narrow streams where more refuges are probably available for small charr, which in turn might enhance the reproductive success of sneaker precocious males. Our findings suggested that plastic effects should clearly be included in investigations of variation in PMRNs.
Consistent design schematics for biological systems: standardization of representation in biological engineering
Authors: Matsuoka Yukiko , Ghosh Samik , Kitano Hiroaki
Published: June 2009

Thediscovery by designparadigm driving research in synthetic biology entails the engineering of de novo biological constructs with well-characterized input–output behaviours and interfaces. The construction of biological circuits requires iterative phases of design, simulation and assembly, leading to the fabrication of a biological device. In order to represent engineered models in a consistent visual format and further simulating themin silico, standardization of representation and model formalism is imperative. In this article, we review different efforts for standardization, particularly standards for graphical visualization and simulation/annotation schemata adopted in systems biology. We identify the importance of integrating the different standardization efforts and provide insights into potential avenues for developing a common framework for model visualization, simulation and sharing across various tools. We envision that such a synergistic approach would lead to the development of global, standardized schemata in biology, empowering deeper understanding of molecular mechanisms as well as engineering of novel biological systems.
Rate-dependent frictional adhesion in natural and synthetic gecko setae
Authors: Gravish Nick , Wilkinson Matt , Sponberg Simon , Parness Aaron , Esparza Noe , Soto Daniel , Yamaguchi Tetsuo , Broide Michael , Cutkosky Mark , Creton Costantino , Autumn Kellar
Published: June 2009

Geckos owe their remarkable stickiness to millions of dry, hard setae on their toes. In this study, we discovered that gecko setae stick more strongly the faster they slide, and do not wear out after 30 000 cycles. This is surprising because friction between dry, hard, macroscopic materials typically decreases at the onset of sliding, and as velocity increases, friction continues to decrease because of a reduction in the number of interfacial contacts, due in part to wear. Gecko setae did not exhibit the decrease in adhesion or friction characteristic of a transition from static to kinetic contact mechanics. Instead, friction and adhesion forces increased at the onset of sliding and continued to increase with shear speed from 500 nm s
−1
to 158 mm s
−1
. To explain how apparently fluid-like, wear-free dynamic friction and adhesion occur macroscopically in a dry, hard solid, we proposed a model based on a population of nanoscopic stick–slip events. In the model, contact elements are either in static contact or in the process of slipping to a new static contact. If stick–slip events are uncorrelated, the model further predicted that contact forces should increase to a critical velocity (
V
*) and then decrease at velocities greater than
V
*. We hypothesized that, like natural gecko setae, but unlike any conventional adhesive, gecko-like synthetic adhesives (GSAs) could adhere while sliding. To test the generality of our results and the validity of our model, we fabricated a GSA using a hard silicone polymer. While sliding, the GSA exhibited steady-state adhesion and velocity dependence similar to that of gecko setae. Observations at the interface indicated that macroscopically smooth sliding of the GSA emerged from randomly occurring stick–slip events in the population of flexible fibrils, confirming our model predictions.
The mother of all protocols: restructuring quantum information’s family tree
Authors: Abeyesinghe Anura , Devetak Igor , Hayden Patrick , Winter Andreas
Published: June 2009

We give a simple, direct proof of the ‘mother’ protocol of quantum information theory. In this new formulation, it is easy to see that the mother, or rather her generalization to the fully quantum Slepian–Wolf protocol, simultaneously accomplishes two goals: quantum communication-assisted entanglement distillation and state transfer from the sender to the receiver. As a result, in addition to her other ‘children’, the mother protocol generates the state-merging primitive of Horodecki, Oppenheim and Winter, a fully quantum reverse Shannon theorem, and a new class of distributed compression protocols for correlated quantum sources which are optimal for sources described by separable density operators. Moreover, the mother protocol described here is easily transformed into the so-called ‘father’ protocol whose children provide the quantum capacity and the entanglement-assisted capacity of a quantum channel, demonstrating that the division of single-sender/single-receiver protocols into two families was unnecessary: all protocols in the family are children of the mother.
Lineage-specific DNA methylation in T cells correlates with histone methylation and enhancer activity
Authors: Schmidl Christian , Klug Maja , Boeld Tina J. , Andreesen Reinhard , Hoffmann Petra , Edinger Matthias , Rehli Michael
Published: June 2009

DNA methylation participates in establishing and maintaining chromatin structures and regulates gene transcription during mammalian development and cellular differentiation. With few exceptions, research thus far has focused on gene promoters, and little is known about the extent, functional relevance, and regulation of cell type-specific DNA methylation at promoter-distal sites. Here, we present a comprehensive analysis of differential DNA methylation in human conventional CD4+T cells (Tconv) and CD4+CD25+regulatory T cells (Treg), cell types whose differentiation and function are known to be controlled by epigenetic mechanisms. Using a novel approach that is based on the separation of a genome into methylated and unmethylated fractions, we examined the extent of lineage-specific DNA methylation across whole gene loci. More than 100 differentially methylated regions (DMRs) were identified that are present mainly in cell type-specific genes (e.g.,FOXP3,IL2RA,CTLA4,CD40LG, andIFNG) and show differential patterns of histone H3 lysine 4 methylation. Interestingly, the majority of DMRs were located at promoter-distal sites, and many of these areas harbor DNA methylation-dependent enhancer activity in reporter gene assays. Thus, our study provides a comprehensive, locus-wide analysis of lineage-specific methylation patterns in Treg and Tconv cells, links cell type-specific DNA methylation with histone methylation and regulatory function, and identifies a number of cell type-specific, CpG methylation-sensitive enhancers in immunologically relevant genes.
Activation of β-Glucan Synthases by Wall-Bound Purple Acid Phosphatase in Tobacco Cells
Authors: Kaida Rumi , Satoh Yumi , Bulone Vincent , Yamada Yohko , Kaku Tomomi , Hayashi Takahisa , Kaneko Takako S.
Published: June 2009

Wall-bound purple acid phosphatases have been shown to be potentially involved in the regulation of plant cell growth. The aim of this work was to further investigate the function of one of these phosphatases in tobacco (Nicotiana tabacum), NtPAP12, using transgenic cells overexpressing the enzyme. The transgenic cells exhibited a higher level of phosphatase activity in their walls. The corresponding protoplasts regenerating a cell wall exhibited a higher rate of β-glucan synthesis and cellulose deposition was increased in the walls of the transgenic cells. A higher level of plasma membrane glucan synthase activities was also measured in detergent extracts of membrane fractions from the transgenic line, while no activation of Golgi-bound glycan synthases was detected. Enzymatic hydrolysis and methylation analysis were performed on the products synthesized in vitro by the plasma membrane enzymes from the wild-type and transgenic lines extracted with digitonin and incubated with radioactive UDP-glucose. The data showed that the glucans consisted of callose and cellulose and that the amount of each glucan synthesized by the enzyme preparation from the transgenic cells was significantly higher than in the case of the wild-type cells. The demonstration that callose and cellulose synthases are activated in cells overexpressing the wall-bound phosphatase NtPAP12 suggests a regulation of these carbohydrate synthases by a phosphorylation/dephosphorylation process, as well as a role of wall-bound phosphatases in the regulation of cell wall biosynthesis.