bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil phosphorus buffering measures should not be adjusted for current phosphorus fertility
Authors: Burkitt L. L. , Sale P. W. G. , Gourley C. J. P.
Published: December 2008

Soil phosphorus (P) sorption is an important and relatively stable soil property which dictates the equilibrium between sorbed and solution P. Soil P sorption measures are commonly adjusted for the effect of current P fertility on the amount of P a soil sorbs. In the case of highly fertilised agricultural soils, however, this adjustment is likely to be inappropriate as it may mask changes in a soil’s capacity to sorb P, which could affect future P fertiliser applications. A study was undertaken to compare adjusted or unadjusted methods of measuring P sorption using 9 pasture soils sampled from southern Victoria which had previously received P fertiliser and lime. The P sorption assessment methods included: P sorption isotherms, P-buffering capacity (PBC) measures (slope between equilibrium P concentration of 0.25 and 0.35 mg P/L), and single-point P-buffering indices (PBI), with methods either adjusted or unadjusted for current P fertility. A single application of 280 kg P/ha, 6 months before sampling, resulted in a general negative displacement of unadjusted P sorption isotherm curves, indicating reduced P sorption on 8 of the 9 soils. Adding the Colwell extractable P concentration to the amount of P sorbed before calculating the slope (PBC+ColP), tended to negate this fertiliser effect and, in 2 of the 9 soils, resulted in a significant increase in PBC+ColP values. Increasing rates of P fertiliser application (up to 280 kg P/ha) resulted in a consistent trend to decreasing PBI values (unadjusted for Colwell P), which was significant at 4 of the 9 sites after 6 months. However, only minimal changes in PBI values were determined when PBI was adjusted for current P fertility (PBI+ColP). Phosphorus sorption properties appeared reasonably stable over time, although 2 soils, both Ferrosols, indicated significant linear increases in PBI values when these sites remained unfertilised for 30 months. Lime significantly increased both PBI and PBI+ColP values at all sites 6 months after application, but the effect generally diminished after 30 months, suggesting PBI measurements should not be taken immediately after liming.
These results demonstrate that unadjusted measures of P sorption are more likely to accurately reflect changes in soil P sorption capacity following P fertiliser applications and suggest that the unadjusted PBI be used in commercial soil testing rather that the currently adjusted PBI+ColP.
Nitrogen isotope enrichment factor as an indicator of denitrification potential in top and subsoil in the Apače Valley, Slovenia
Authors: Pintar Marina , Bolta Spela Velikonja , Lobnik Franc
Published: December 2008

Denitrification is still a poorly explained process in soil nitrogen cycles. Nitrogen isotope analyses, in combination with conventional soil-science methods (i.e. rate measurements), permit the tracing and quantification of several turn-over and transfer processes in soils. The aim of the presented investigations is to determine the 15N isotope enrichment factor (ε) in a laboratory experiment during denitrification in the topsoil and subsoil layer of a Eutric Fluvisol (FAO classification) from the Apače Valley (NE Slovenia). Intact soil cores taken from depths of 0.10–0.20 m and 0.90–1.00 m were incubated under anaerobic conditions at a temperature of 18°C. A nitrate dose of 116 mg N-NO3/L was added to the topsoil layer and 58 mg N-NO3/L to the subsoil material. Glucose (250 mg) was added to each soil column. After the initial 24 h of incubation, water samples were taken every 8 h. The isotope enrichment factor for denitrification in the upper soil-layer columns was –7.60 ± 1.28‰ and for subsoil columns –34.91 ± 1.77‰ (n = 3). The isotope enrichment factor close to zero demonstrated that microorganisms easily consumed abundant substrate in the topsoil layer. Added nitrate and glucose exceeded the capacity of the microbial population in the subsoil and the process was limited by a low microbial population for which a high ε is characteristic.
Fate of applied biosolids nitrogen in a cut and remove forage system on an alluvial clay loam soil
Authors: Pu Guixin , Bell Mike , Barry Glenn , Want Peter
Published: December 2008

The fate of nitrogen (N) applied in biosolids was investigated in a forage production system on an alluvial clay loam soil in south-eastern Queensland, Australia. Biosolids were applied in October 2002 at rates of 6, 12, 36, and 54 dry t/ha for aerobically digested biosolids (AE) and 8, 16, 48, and 72 dry t/ha for anaerobically digested biosolids (AN). Rates were based on multiples of the Nitrogen Limited Biosolids Application rate (0.5, 1, 3, and 4.5NLBAR) for each type of biosolid. The experiment included an unfertilised control and a fertilised control that received multiple applications of synthetic fertiliser. Forage sorghum was planted 1 week after biosolids application and harvested 4 times between December 2002 and May 2003. Dry matter production was significantly greater from the biosolids-treated plots (21–27 t/ha) than from the unfertilised (16 t/ha) and fertilised (18 t/ha) controls. The harvested plant material removed an extra 148–488 kg N from the biosolids-treated plots. Partial N budgets were calculated for the 1NLBAR and 4.5NLBAR treatments for each biosolids type at the end of the crop season. Crop removal only accounted for 25–33% of the applied N in the 1NLBAR treatments and as low as 8–15% with 4.5NLBAR. Residual biosolids N was predominantly in the form of organic N (38–51% of applied biosolids N), although there was also a significant proportion (10–23%) as NO3-N, predominantly in the top 0.90 m of the soil profile. From 12 to 29% of applied N was unaccounted for, and presumed to be lost as gaseous nitrogen and/or ammonia, as a consequence of volatilisation or denitrification, respectively. In-season mineralisation of organic N in biosolids was 43–59% of the applied organic N, which was much greater than the 15% (AN)–25% (AE) expected, based on current NLBAR calculation methods. Excessive biosolids application produced little additional biomass but led to high soil mineral N concentrations that were vulnerable to multiple loss pathways. Queensland Guidelines need to account for higher rates of mineralisation and losses via denitrification and volatilisation and should therefore encourage lower application rates to achieve optimal plant growth and minimise the potential for detrimental impacts on the environment.
Temperature regulates limb length in homeotherms by directly modulating cartilage growth
Authors: Serrat Maria A. , King Donna , Lovejoy C. Owen
Published: December 2008

Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory adaptation is frequently presumed to be the primary basis of this phenomenon, important but frequently overlooked research has shown that appendage outgrowth is also markedly influenced by environmental temperature. Alteration of limb blood flow via vasoconstriction/vasodilation is the current default hypothesis for this growth plasticity, but here we show that tissue perfusion does not fully account for differences in extremity elongation in mice. We show that peripheral tissue temperature closely reflects housing temperature in vivo, and we demonstrate that chondrocyte proliferation and extracellular matrix volume strongly correlate with tissue temperature in metatarsals cultured without vasculature in vitro. Taken together, these data suggest that vasomotor changes likely modulate extremity growth indirectly, via their effects on appendage temperature, rather than vascular nutrient delivery. When combined with classic evolutionary theory, especially genetic assimilation, these results provide a potentially comprehensive explanation of Allen's Rule, and may substantially impact our understanding of phenotypic variation in living and extinct mammals, including humans.
Alphavirus-derived small RNAs modulate pathogenesis in disease vector mosquitoes
Authors: Myles Kevin M. , Wiley Michael R. , Morazzani Elaine M. , Adelman Zach N.
Published: December 2008

Mosquito-borne viruses cause significant levels of morbidity and mortality in humans and domesticated animals. Maintenance of mosquito-borne viruses in nature requires a biological transmission cycle that involves alternating virus replication in a susceptible vertebrate and mosquito host. Although the vertebrate infection is acute and often associated with disease, continual transmission of these viruses in nature depends on the establishment of a persistent, nonpathogenic infection in the mosquito vector. An antiviral RNAi response has been shown to limit the replication of RNA viruses in flies. However, the importance of the RNAi pathway as an antiviral defense in mammals is unclear. Differences in the immune responses of mammals and mosquitoes may explain why these viruses are not generally associated with pathology in the invertebrate host. We identified virus-derived small interfering RNAs (viRNAs), 21 nt in length, in
Aedes aegypti
infected with the mosquito-borne virus, Sindbis (SINV). viRNAs had an asymmetric distribution that spanned the length of the SINV genome. To determine the role of viRNAs in controlling pathogenic potential, mosquitoes were infected with recombinant alphaviruses expressing suppressors of RNA silencing. Decreased survival was observed in mosquitoes in which the accumulation of viRNAs was suppressed. These results suggest that an exogenous siRNA pathway is essential to the survival of mosquitoes infected with alphaviruses and, thus, the maintenance of these viruses in nature.
Cell shape and cell-wall organization in Gram-negative bacteria
Authors: Huang Kerwyn Casey , Mukhopadhyay Ranjan , Wen Bingni , Gitai Zemer , Wingreen Ned S.
Published: December 2008

In bacterial cells, the peptidoglycan cell wall is the stress-bearing structure that dictates cell shape. Although many molecular details of the composition and assembly of cell-wall components are known, how the network of peptidoglycan subunits is organized to give the cell shape during normal growth and how it is reorganized in response to damage or environmental forces have been relatively unexplored. In this work, we introduce a quantitative physical model of the bacterial cell wall that predicts the mechanical response of cell shape to peptidoglycan damage and perturbation in the rod-shaped Gram-negative bacterium
Escherichia coli
. To test these predictions, we use time-lapse imaging experiments to show that damage often manifests as a bulge on the sidewall, coupled to large-scale bending of the cylindrical cell wall around the bulge. Our physical model also suggests a surprising robustness of cell shape to peptidoglycan defects, helping explain the observed porosity of the cell wall and the ability of cells to grow and maintain their shape even under conditions that limit peptide crosslinking. Finally, we show that many common bacterial cell shapes can be realized within the same model via simple spatial patterning of peptidoglycan defects, suggesting that minor patterning changes could underlie the great diversity of shapes observed in the bacterial kingdom.
HDAC2 blockade by nitric oxide and histone deacetylase inhibitors reveals a common target in Duchenne muscular dystrophy treatment
Authors: Colussi Claudia , Mozzetta Chiara , Gurtner Aymone , Illi Barbara , Rosati Jessica , Straino Stefania , Ragone Gianluca , Pescatori Mario , Zaccagnini Germana , Antonini Annalisa , Minetti Giulia , Martelli Fabio , Piaggio Giulia , Gallinari Paola , Steinkuhler Christian , Clementi Emilio , Dell'Aversana Carmela , Altucci Lucia , Mai Antonello , Capogrossi Maurizio C. , Puri Pier Lorenzo , Gaetano Carlo
Published: December 2008

The overlapping histological and biochemical features underlying the beneficial effect of deacetylase inhibitors and NO donors in dystrophic muscles suggest an unanticipated molecular link among dystrophin, NO signaling, and the histone deacetylases (HDACs). Higher global deacetylase activity and selective increased expression of the class I histone deacetylase HDAC2 were detected in muscles of dystrophin-deficient MDX mice. In vitro and in vivo siRNA-mediated down-regulation of HDAC2 in dystrophic muscles was sufficient to replicate the morphological and functional benefits observed with deacetylase inhibitors and NO donors. We found that restoration of NO signaling in vivo, by adenoviral-mediated expression of a constitutively active endothelial NOS mutant in MDX muscles, and in vitro, by exposing MDX-derived satellite cells to NO donors, resulted in HDAC2 blockade by cysteine S-nitrosylation. These data reveal a special contribution of HDAC2 in the pathogenesis of Duchenne muscular dystrophy and indicate that HDAC2 inhibition by NO-dependent S-nitrosylation is important for the therapeutic response to NO donors in MDX mice. They also define a common target for independent pharmacological interventions in the treatment of Duchenne muscular dystrophy.
A geometric constraint, the head-to-tail exclusion rule, may be the basis for the isolated-pentagon rule in fullerenes with more than 60 vertices
Authors: Schein Stan , Friedrich Tara
Published: December 2008

Carbon atoms self-assemble into the famous soccer-ball shaped Buckminsterfullerene (C
60
), the smallest fullerene cage that obeys the isolated-pentagon rule (IPR). Carbon atoms self-assemble into larger (
n
> 60 vertices) empty cages as well—but only the few that obey the IPR—and at least 1 small fullerene (
n
≤ 60) with adjacent pentagons. Clathrin protein also self-assembles into small fullerene cages with adjacent pentagons, but just a few of those. We asked why carbon atoms and clathrin proteins self-assembled into just those IPR and small cage isomers. In answer, we described a geometric constraint—the head-to-tail exclusion rule—that permits self-assembly of just the following fullerene cages: among the 5,769 possible small cages (
n
≤ 60 vertices) with adjacent pentagons, only 15; the soccer ball (
n
= 60); and among the 216,739 large cages with 60 <
n
≤ 84 vertices, only the 50 IPR ones. The last finding was a complete surprise. Here, by showing that the largest permitted fullerene with adjacent pentagons is one with 60 vertices and a ring of interleaved hexagons and pentagon pairs, we prove that for all
n
> 60, the head-to-tail exclusion rule permits only (and all) fullerene cages and nanotubes that obey the IPR. We therefore suggest that self-assembly that obeys the IPR may be explained by the head-to-tail exclusion rule, a geometric constraint.
Satanic Moments
Authors: Appignanesi Lisa
Published: December 2008

Lisa Appignanesi recalls how a ground-breaking, visionary novel was hijacked and transformed into an international political cause
Rushdie Revisited
Authors: Gordimer Nadine
Published: December 2008

Nadine Gordimer pays tribute to a fellow novelist’s feats of imagination, from Midnight’s Children to Shalimar the Clown
Image Control
Authors: Miller Zoriah
Published: December 2008

Zoriah Miller wanted to reveal the true cost of the war in Iraq: the military had other ideas
Final Chapter
Authors: Finan Christopher M
Published: December 2008

Christopher M Finan is fighting sweeping powers to monitor Americans’ reading habits
Fake Debate
Authors: Krauss Lawrence
Published: December 2008

Supporters of Intelligent Design have played a clever PR game to gain credibility. Lawrence Krauss explains why it’s an attack on reason
The Denial Machine
Authors: Piltz Rick
Published: December 2008

Rick Piltz examines political interference in climate change research: a scandal he helped to expose
Reviewing the literature on the student learning experience in higher education
Authors: Ertl Hubert , Wright Susannah
Published: December 2008

Education Academy which aimed at mapping the research base around the student learning experience in higher education (HE). The project aimed to 1) provide an overview of the ways in which the student learning experience in HE has been and is conceptualised; 2) provide an overview of
interventions aimed at producing a more effective learning experience; and 3) review the methodological approaches adopted to investigate the student learning experience. The paper outlines the review approach adopted by this project and presents an analytical map in which reviewed studies
are categorised in terms of the methods they adopt and the area of investigation. Selected findings in the areas of inventory-based studies, assessment and feedback and teaching, curriculum and learning environments are discussed. The project identified a large, but broad, heterogeneous and
somewhat scattered research base, dominated by a tradition of studies using inventory methods, and otherwise by small and localised studies often conducted by practitioners researching their own subject areas. The paper concludes with a discussion of the strengths and weaknesses of the project's
methods, and recommendations for developing the student learning experience research base in the future.
Learning spaces in higher education: an under-researched topic
Authors: Temple Paul
Published: December 2008

The connections between the design and use of space in higher education, and the production of teaching and learning, and of research, are not well understood. This paper reports on a literature review on these topics, and shows that higher education spaces can be considered in various
ways: in terms of campus design, in terms of how space can support the development of a university community, the needs of specialist spaces, and the impact of technology on space use. Space issues are central to the operation of universities, and further research is needed to illuminate the
connections between space and institutional effectiveness.
Informed choice? The new English student funding system and widening participation
Authors: Adnett Nick , Tlupova Diana
Published: December 2008

The new English system of student finance seeks to resolve a higher education policy trilemma created by government's desire to switch more of the costs on to students, whilst seeking to promote both increased and widening participation. The rationale for this new funding system is
based upon orthodox economic analysis which, the authors argue, rests upon inappropriate assumptions. Survey evidence from recent entrants is presented to support this critique and to question whether the current system can promote both informed student decision-making and widening participation.
Problem-based learning: a critical rationalist perspective
Authors: Parton Graham , Bailey Richard
Published: December 2008

Although problem-based learning is being adopted by many institutions around the world as an effective model of learning in higher education, there is a surprising lack of critique in the problem-based learning literature in relation to its philosophical characteristics. This paper
explores epistemology as a starting point for investigating the theoretical underpinnings of problem-based learning as a learning model. Criticisms of empiricism are analysed in terms of the perceived learning outcomes of learners undertaking a problem-based learning curriculum. It is argued
that models of empiricism theorised by philosophers such as Bacon, Locke and Hume cannot fully account for the learning model found in problem-based learning curricula. It is proposed that an alternative epistemological approach is needed. The work of Karl Popper is discussed, whose critical
rationalist epistemology emphasises the generation of bold conjectures and criticism. Popper's work shows a positive contribution to the demands of higher education, characterised by learners who are serious about making professional progress. The paper concludes by critically analysing the
tensions and contradictions of problem-based learning in light of Popper's epistemological theory of critical rationalism. It is argued that a critical rationalist perspective has educational benefits for students as it creates an environment rich in critical thinking, reading and writing
and values disjunction and challenge.
Partnering and Consumer Orientation: Techniques That Move Occupational Safety and Health Research into Practice
Authors: Hudson Heidi , Snawder John , Esswein Eric , Striley Cynthia
Published: December 2008

First responders, remediation workers, and other personnel frequently encounter clandestine methamphetamine (meth) labs or previous meth lab sites while performing their everyday jobs. National Institute for Occupational Safety and Health (NIOSH) researchers developed a real-time method for detecting methamphetamine on surfaces for use by these workers. This case study describes how a federal agency developed and field-tested this innovative technology and collaborated with a private sector partner to commercialize and market the technology and the impact these actions had on its transfer and adoption.
TLR7-dependent and FcγR-independent production of type I interferon in experimental mouse lupus
Authors: Lee Pui Y. , Kumagai Yutaro , Li Yi , Takeuchi Osamu , Yoshida Hideo , Weinstein Jason , Kellner Erinn S. , Nacionales Dina , Barker Tolga , Kelly-Scumpia Kindra , van Rooijen Nico , Kumar Himanshu , Kawai Taro , Satoh Minoru , Akira Shizuo , Reeves Westley H.
Published: December 2008

Increased type I interferon (IFN-I) production and IFN-stimulated gene (ISG) expression are linked to the pathogenesis of systemic lupus erythematosus (SLE). Although the mechanisms responsible for dysregulated IFN-I production in SLE remain unclear, autoantibody-mediated uptake of endogenous nucleic acids is thought to play a role. 2,6,10,14-tetramethylpentadecane (TMPD; also known as pristane) induces a lupus-like disease in mice characterized by immune complex nephritis with autoantibodies to DNA and ribonucleoproteins. We recently reported that TMPD also causes increased ISG expression and that the development of the lupus is completely dependent on IFN-I signaling (Nacionales, D.C., K.M. Kelly-Scumpia, P.Y. Lee, J.S. Weinstein, R. Lyons, E. Sobel, M. Satoh, and W.H. Reeves. 2007. Arthritis Rheum. 56:3770–3783). We show that TMPD elicits IFN-I production, monocyte recruitment, and autoantibody production exclusively through a Toll-like receptor (TLR) 7– and myeloid differentiation factor 88 (MyD88)–dependent pathway. In vitro studies revealed that TMPD augments the effect of TLR7 ligands but does not directly activate TLR7 itself. The effects of TMPD were amplified by the Y-linked autoimmune acceleration cluster, which carries a duplication of the TLR7 gene. In contrast, deficiency of Fcγ receptors (FcγRs) did not affect the production of IFN-I. Collectively, the data demonstrate that TMPD-stimulated IFN-I production requires TLR7/MyD88 signaling and is independent of autoantibody-mediated uptake of ribonucleoproteins by FcγRs.
A novel role of CD4 Th17 cells in mediating cardiac allograft rejection and vasculopathy
Authors: Yuan Xueli , Paez-Cortez Jesus , Schmitt-Knosalla Isabela , D'Addio Francesca , Mfarrej Bechara , Donnarumma Michela , Habicht Antje , Clarkson Michael R. , Iacomini John , Glimcher Laurie H. , Sayegh Mohamed H. , Ansari M. Javeed
Published: December 2008

T-bet plays a crucial role in Th1 development. We investigated the role of T-bet in the development of allograft rejection in an established MHC class II–mismatched (bm12 into B6) model of chronic allograft vasculopathy (CAV). Intriguingly, and in contrast to IFN-γ−/− mice that are protected from CAV, T-bet−/− recipients develop markedly accelerated allograft rejection accompanied by early severe vascular inflammation and vasculopathy, and infiltration by predominantly IL-17–producing CD4 T cells. Concurrently, T-bet−/− mice exhibit a T helper type 1 (Th1)–deficient environment characterized by profound IFN-γ deficiency, a Th2 switch characterized by increased production of interleukin (IL) 4, IL-5, IL-10, and IL-13 cytokines, as well as increased production of the proinflammatory cytokines IL-6, IL-12p40, and IL-17. Neutralization of IL-17 inhibits accelerated allograft rejection and vasculopathy in T-bet−/− mice. Interestingly, CD4 but not CD8 T cell deficiency in T-bet−/− mice affords dramatic protection from vasculopathy and facilitates long-term graft acceptance. This is the first study establishing that in the absence of Th1-mediated alloimmune responses, CD4 Th17 cells mediate an aggressive proinflammatory response culminating in severe accelerated allograft rejection and vasculopathy. These results have important implications for the development of novel therapies to target this intractable problem in clinical solid organ transplantation.
Outbreak of Multidrug-ResistantPseudomonas aeruginosaColonization and Infection Secondary to Imperfect Intensive Care Unit Room Design
Authors: Hota Susy , Hirji Zahir , Stockton Karen , Lemieux Camille , Dedier Helen , Wolfaardt Gideon , Gardam Michael A.
Published: December 2008

Background.

Pseudomonas aeruginosahas been increasingly recognized for its ability to cause significant hospital-associated outbreaks, particularly since the emergence of multidrug-resistant strains. Biofilm formation allows the pathogen to persist in environmental reservoirs. Thus, multiple hospital room design elements, including sink placement and design, can impact nosocomial transmission ofP. aeruginosaand other pathogens.

Methods.

From December 2004 through March 2006, 36 patients exposed to the intensive care unit or transplant units of a tertiary care hospital were infected with a multidrug-resistant strain ofP. aeruginosa. All phenotypically similar isolates were examined for genetic relatedness by means of pulsed-field gel electrophoresis. Clinical characteristics of the affected patients were collected, and a detailed epidemiological and environmental investigation of potential sources was carried out.

Results.

Seventeen of the infected patients died within 3 months; for 12 (71%) of these patients, infection with the outbreak organism contributed to or directly caused death. The source of the outbreak was traced to hand hygiene sink drains, where biofilms containing viable organisms were found. Testing by use of a commercial fluorescent marker demonstrated that when the sink was used for handwashing, drain contents splashed at least 1 meter from the sink. Various attempts were made to disinfect the drains, but it was only when the sinks were renovated to prevent splashing onto surrounding areas that the outbreak was terminated.

Conclusion.

This report highlights the importance of biofilms and of sink and patient room design in the propagation of an outbreak and suggests some strategies to reduce the risks associated with hospital sinks.
Prevalence of Colonization With Community-Associated Methicillin-ResistantStaphylococcus aureusAmong End-Stage Renal Disease Patients and Healthcare Workers
Authors: Johnson Leonard B. , Jose Jinson , Yousif Farah , Pawlak Joan , Saravolatz Louis D.
Published: December 2008

Objective.

To evaluate the prevalence, epidemiologic features, and molecular characteristics of colonization with community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) among hospitalized dialysis patients and their healthcare workers (HCWs).

Design.

Prospective observational clinical and laboratory study of nasal colonization.

Setting.

A 600-bed urban academic medical center.

Subjects.

One hundred twenty hospitalized dialysis inpatients and 100 HCWs.

Results.

Of 120 patients, 40 (33%) were colonized withS. aureus; 26 (65%) of these 40 were colonized with MRSA. Among the 26 MRSA isolates, 10 (38.5%) carried staphylococcal cassette chromosome (SCC)mectype IV (ie, CA-MRSA), and 7 of these 10 carried the genes for the Panton-Valentine leukocidin (PVL) toxin. Patients colonized with healthcare-associated MRSA strains and those colonized with CA-MRSA strains were similar, except for a higher frequency of a history of congestive heart failure among those with healthcare-associated MRSA strains (P= .014). Among 10 patients who presented with or developed anS. aureusinfection while hospitalized, 8 were colonized withS. aureus, 7 with MRSA, and 3 with SCCmectype IV strains. Among 100 HCWs, 31 were colonized withS. aureus, including 6 with MRSA; 2 of the MRSA isolates belonged to CA-MRSA strains, and soft-tissue infections were reported in one of the HCWs and in the family member of the other HCW colonized with these strains.

Conclusions.

There is a high rate of colonization with MRSA and CA-MRSA among hospitalized dialysis patients and their HCWs. As other studies have found, it appears that individuals are being colonized with both CA-MRSA strains and healthcare-associated MRSA strains.
Developing best practice for using Marxan to locate Marine Protected Areas in European waters
Authors: Smith Robert J. , Eastwood Paul D. , Ota Yoshitaka , Rogers Stuart I.
Published: December 2008

Smith, R. J., Eastwood, P. D., Ota, Y., and Rogers, S. I. 2009. Developing best practice for using Marxan to locate Marine Protected Areas in European waters. – ICES Journal of Marine Science, 66: 188–194. Several recent studies have investigated the use of the conservation planning software Marxan to design Marine Protected Area (MPA) networks in UK waters. The systematic conservation planning approach embodied by Marxan has a number of advantages, but these studies have highlighted the need for guidance and advice on best practice. Here, we discuss two broad topics that we feel should inform future developments in the UK and elsewhere in the European Union. First, several technical issues need to be addressed to ensure the scientific defensibility of any conservation planning project. These include identifying which conservation features should be represented in an MPA system, developing a system for setting representation targets, and identifying which data should be included to minimize conflict with human uses of the sea. Second, it is necessary for researchers to engage at an early stage with those responsible for implementation and recognize that reserve selection should be part of a broader conservation planning process centred on a stakeholder-developed implementation strategy. A more-inclusive approach will make use of technical outputs, such as those generated by Marxan, as part of the process of policy development.
Two- and three-dimensional maturation reaction norms for the eastern Baltic cod, Gadus morhua
Authors: Vainikka Anssi , Gårdmark Anna , Bland Barbara , Hjelm Joakim
Published: December 2008

Vainikka, A., Gårdmark, A., Bland, B., and Hjelm, J. 2009. Two- and three-dimensional maturation reaction norms for the eastern Baltic cod, Gadus morhua. – ICES Journal of Marine Science, 66: 248–257. Industrial fisheries have caused decreases in the size and age at maturation in several stocks of cod (Gadus morhua). Although earlier maturation can be a phenotypic response to improved growth conditions, estimation of probabilistic maturation reaction norms (PMRNs) can remove most impacts of growth and demography from maturation schedules and has often revealed a residual, potentially genetic, trend. In this study, size- and condition-based PMRNs were estimated for eastern Baltic cod cohorts from 1987 to 2003. The PMRNs suggested that both length and condition at 50% probability of maturing (Lp50 and Cp50) had decreased by 15–20%, more notably in females. Simultaneously with changes in maturation schedules, the length-at-age of mature fish decreased for most combinations of age and sex. Decrease in growth may be partly explained by advanced maturation, but temporal fluctuations in PMRNs suggest also a residual environmental impact on both growth and maturation. The results may indicate a genetic change in the eastern Baltic cod stock, adding pressure to reduce fishing mortality on it.
A micropolar theory for the finite elasticity of open-cell cellular solids
Authors: Hård af Segerstad Per , Toll Staffan , Larsson Ragnar
Published: December 2008

A mechanistic model is presented for an open-cell cellular solid consisting of a three-dimensional network of elastic struts. By considering the bending and torsion as well as stretching and buckling of the struts, we allow for length-scale effects in the macroscopic response. Constitutive equations are developed for the force and couple stress tensors, accounting for finite deformations and anisotropy. The consistent tangent stiffness operators are derived and the equations are fully implemented in a nonlinear two-dimensional finite-element solution scheme for the coupled displacement/rotation problem. A boundary-value problem of a shear gap with prescribed boundary rotations is analysed, and the model is shown to predict the well-known gap–size effect. The mechanistic model allows some detailed interpretation of the micropolar behaviour, such as the effects of strut slenderness, strut length and anisotropy.
On dissolution and reassembly of filamentary reinforcing networks in hyperelastic materials
Authors: Demirkoparan Hasan , Pence Thomas J , Wineman Alan
Published: December 2008

We generalize a theory for modelling the scission and reforming of cross links in isotropic polymeric materials in order to treat anisotropic mechanical behaviour. Our focus is on materials in which elastic fibres are embedded in an elastic matrix. The fibres may have a different natural stress-free configuration than that of the matrix, e.g. the fibres may be initially crimped in the absence of load. The modelling process allows the fibres to dissolve as deformation proceeds and then to immediately reassemble in the current direction of maximum principal stretch. This results in softening, altered mechanical properties and the possibility of permanent set. We illustrate a rich variety of such mechanical behaviours in the context of uniaxial stretch. The phenomena illustrated have important implications for the influence of mechanical factors in the remodelling of fibrous soft matter including biological tissue.
H3K27me3 forms BLOCs over silent genes and intergenic regions and specifies a histone banding pattern on a mouse autosomal chromosome
Authors: Pauler Florian M. , Sloane Mathew A. , Huang Ru , Regha Kakkad , Koerner Martha V. , Tamir Ido , Sommer Andreas , Aszodi Andras , Jenuwein Thomas , Barlow Denise P.
Published: December 2008

In mammals, genome-wide chromatin maps and immunofluorescence studies show that broad domains of repressive histone modifications are present on pericentromeric and telomeric repeats and on the inactive X chromosome. However, only a few autosomal loci such as silent Hox gene clusters have been shown to lie in broad domains of repressive histone modifications. Here we present a ChIP-chip analysis of the repressive H3K27me3 histone modification along chr 17 in mouse embryonic fibroblast cells using an algorithm named broad local enrichments (BLOCs), which allows the identification of broad regions of histone modifications. Our results, confirmed by BLOC analysis of a whole genome ChIP-seq data set, show that the majority of H3K27me3 modifications form BLOCs rather than focal peaks. H3K27me3 BLOCs modify silent genes of all types, plus flanking intergenic regions and their distribution indicates a negative correlation between H3K27me3 and transcription. However, we also found that some nontranscribed gene-poor regions lack H3K27me3. We therefore performed a low-resolution analysis of whole mouse chr 17, which revealed that H3K27me3 is enriched in mega-base-pair-sized domains that are also enriched for genes, short interspersed elements (SINEs) and active histone modifications. These genic H3K27me3 domains alternate with similar-sized gene-poor domains. These are deficient in active histone modifications, as well as H3K27me3, but are enriched for long interspersed elements (LINEs) and long-terminal repeat (LTR) transposons and H3K9me3 and H4K20me3. Thus, an autosome can be seen to contain alternating chromatin bands that predominantly separate genes from one retrotransposon class, which could offer unique domains for the specific regulation of genes or the silencing of autonomous retrotransposons.
Reward prediction error signals by reticular formation neurons
Authors: Puryear Corey B. , Mizumori Sheri J.Y.
Published: December 2008

As a key part of the brain’s reward system, midbrain dopamine neurons are thought to generate signals that reflect errors in the prediction of reward. However, recent evidence suggests that “upstream” brain areas may make important contributions to the generation of prediction error signals. To address this issue, we recorded neural activity in midbrain reticular formation (MRNm) while rats performed a spatial working memory task. A large proportion of these neurons displayed positive and negative reward prediction error-related activity that was strikingly similar to that observed in dopamine neurons. Therefore, MRNm may be a source of reward prediction error signals.
Immediate extinction causes a less durable loss of performance than delayed extinction following either fear or appetitive conditioning
Authors: Woods Amanda M. , Bouton Mark E.
Published: December 2008

Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In all experiments, conditioning and extinction were accomplished in single sessions, and retention testing took place 24 h after extinction. In both fear and appetitive conditioning, immediate extinction (beginning 10 min after conditioning) caused a faster loss of responding than delayed extinction (beginning 24 h after conditioning). However, immediate extinction was less durable than delayed extinction: There was stronger spontaneous recovery during the final retention test. There was also substantial renewal of responding when the physical context was changed between immediate extinction and testing (Experiment 1). The results suggest that, in these two widely used conditioning preparations, immediate extinction does not erase or depotentiate the original learning, and instead creates a less permanent reduction in conditioned responding. Results did not support the possibility that the strong recovery after immediate extinction was due to a mismatch in the recent “context” provided by the presence or absence of a recent conditioning experience. Several other accounts are considered.
Chronic cannabinoid administration in vivo compromises extinction of fear memory
Authors: Lin Hui-Ching , Mao Sheng-Chun , Chen Po-See , Gean Po-Wu
Published: December 2008

Endocannabinoids are critically involved in the extinction of fear memory. Here we examined the effects of repeated cannabinoid administration on the extinction of fear memory in rats and on inhibitory synaptic transmission in medial prefrontal cortex (mPFC) slices. Rats were treated with the CB1 receptor agonist WIN55212-2 (WIN 10 mg/kg, i.p.) once per day for 7 d. On day 8, the rats were submitted to a standard fear conditioning procedure, and retention of memory was measured with potentiated startle paradigm. We found that (1) WIN-pretreated rats exhibited much less extinction to cue alone presentations; (2) the reduction of fear-potentiated startle normally seen when the CB1 receptor agonists were infused into the mPFC was absent in the WIN-pretreated rats; (3) WIN-induced inhibition of GABAergic transmission was significantly less in slices from the WIN-pretreated rats than that from the vehicle-pretreated control; (4) WIN failed to induce extracellular signal-regulated kinases (ERKs) phosphorylation in the WIN-pretreated rats; and (5) the level of CB1 receptor in the WIN-pretreated rats was lower than that of vehicle-pretreated rats. These results suggest that endocannabinoids within the mPFC play an important role in the extinction of conditioned fear. However, long-term marijuana use may limit its clinical efficacy for the treatment of anxiety disorders.
The NMDA antagonist MK-801 disrupts reconsolidation of a cocaine-associated memory for conditioned place preference but not for self-administration in rats
Authors: Brown Travis E. , Lee Brian R. , Sorg Barbara A.
Published: December 2008

Recent research suggests that drug-related memories are reactivated after exposure to environmental cues and may undergo reconsolidation, a process that can strengthen memories. Conversely, reconsolidation may be disrupted by certain pharmacological agents such that the drug-associated memory is weakened. Several studies have demonstrated disruption of memory reconsolidation using a drug-induced conditioned place preference (CPP) task, but no studies have explored whether cocaine-associated memories can be similarly disrupted in cocaine self-administering animals after a cocaine priming injection, which powerfully reinstates drug-seeking behavior. Here we used cocaine-induced CPP and cocaine self-administration to investigate whether the N-methyl-D-aspartate receptor antagonist (+)-5methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) given just prior to reactivation sessions would suppress subsequent cocaine-primed reinstatement (disruption of reconsolidation). Systemic injection of MK-801 (0.05 or 0.20 mg/kg administered intraperitoneally) in rats just prior to reactivation of the cocaine-associated memory in the CPP context attenuated subsequent cocaine-primed reinstatement, while no disruption occurred in rats that did not receive reactivation in the CPP context. However, in rats trained to self-administer cocaine, systemic administration of MK-801 just prior to either of two different types of reactivation sessions had no effect on subsequent cocaine-primed reinstatement of lever-pressing behavior. Thus, systemic administration of MK-801 disrupted the reconsolidation of a cocaine-associated memory for CPP but not for self-administration. These findings suggest that cocaine-CPP and self-administration do not use similar neurochemical processes to disrupt reconsolidation or that cocaine-associated memories in self-administering rats do not undergo reconsolidation, as assessed by lever-pressing behavior under cocaine reinstatement conditions.
Effect of incubation temperature on muscle growth of barramundi Lates calcarifer at hatch and post‐exogenous feeding
Authors: Carey G. R. , Kraft P. G. , Cramp R. L. , Franklin C. E.
Published: December 2008

Muscle morphology was investigated in newly hatched barramundi Lates calcarifer larvae incubated at set temperatures (26, 29 and 31° C) prior to hatching. Three days after hatching (the start of exogenous feeding), larvae from the 26 and 31° C treatments were each divided into two groups and reared at that temperature or transferred over the period of several hours to 29° C (control temperature). Incubation temperature significantly affected muscle cellularity in the developing embryo, with larvae incubated at 26° C (mean ±s.e. 223·3 ± 7·9) having on average 14·4% more inner muscle fibres than those incubated at 31° C (195·2 ± 8·8) and 4·8% more than those incubated at 29° C (213·5 ± 4·7). Conversely, inner muscle fibre cross‐sectional area significantly increased at the warm incubation temperature in L. calcarifer, so that the total cross‐sectional muscle area was not different between treatment groups. The total cross‐sectional area of superficial muscle fibres and the proportion of superficial to total fibre cross‐sectional area in just hatched L. calcarifer were also affected by incubation temperature, with incubation at the cool temperature (26° C) increasing both the total cross‐sectional area and proportion of superficial muscle fibres. By 9 days post‐hatch, the aforementioned differences were no longer significant. Similarly, there was no difference in total superficial fibre cross‐sectional area between any treatment groups of L. calcarifer, whereas incubation temperature still significantly affected the proportion of superficial to total muscle fibre cross‐sectional area. Larvae hatched and grown at 31° C had a significantly reduced percentage of superficial muscle cross‐sectional area (mean ±s.e. 5·11 ± 0·66%) compared with those incubated and grown at 29° C (8·04 ± 0·77%) and 26° C (9·32 ± 0·56%) and those incubated at 26° C and transferred to 29° C (7·52 ± 0·53%), and incubated at 31° C and transferred to 29° C (6·28 ± 0·69%). These results indicate that changes in muscle cellularity induced by raising or lowering the incubation temperature of L. calcarifer display varying degrees of persistence over developmental time. The significance of these findings to the culture of L. calcarifer is discussed.
Cohesive social behaviour shortens the stress response: the effects of conspecifics on the stress response in lake sturgeon Acipenser fulvescens
Authors: Allen P. J. , BARTH C. C. , Peake S. J. , Abrahams M. V. , Anderson W. G.
Published: December 2008

An examination was made of whether social interactions can have a beneficial effect through the attenuation of the stress response in a social species. In the first experiment, one larger (mean ±s.e. 194·0 ± 12·5 g) and seven smaller (32·0 ± 2·6 g) juvenile lake sturgeon Acipenser fulvescens were placed in tanks to determine whether a classic dominance effect would be established based on body size (n = 6). Large fish did not establish a territory or aggressively interact with smaller fish, as there were no significant differences in nearest‐neighbour distances and an absence of aggressive behaviour (biting, chasing and pushing). In the second experiment, it was hypothesized that the presence of conspecifics would have a beneficial effect through an attenuation of the stress response. Fish in groups or isolation were stressed by a brief aerial exposure (30 s), and blood plasma was measured at regular time intervals (0, 20, 40, 60, 120 and 240 min) following the stressor via an implanted cannula (n = 9–11). The presence of conspecifics did not affect the peak cortisol response, however, the overall cortisol response was shorter in duration compared to fish in isolation. Furthermore, secondary stress variables (plasma ions and glucose) showed differences between fish in groups and isolation. The results of these experiments suggest that social interaction plays an important and beneficial role in regulating the stress response in cohesive social species such as A. fulvescens.
Herpes simplex virus type 1 dysregulates anti‐fungal defenses preventing monocyte activation and downregulating toll‐like receptor‐2
Authors: Cermelli Claudio , Orsi Carlotta Francesca , Ardizzoni Andrea , Lugli Enrico , Cenacchi Valeria , Cossarizza Andrea , Blasi Elisabetta
Published: December 2008

We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP‐1 monocytic cell line is first infected with HSV‐1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV‐1‐infected THP‐1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL‐12 production was also observed. Cytofluorimetric analysis showed that HSV‐1‐infected monocytes exhibit: (i) downregulated TLR‐2 and TLR‐4, critical structures in fungal recognition; (ii) reduced expression of CD38 and CD69, known to be important markers of monocyte activation; and (iii) enhanced expression of apoptosis and necrosis markers, in the absence of altered cell proliferation. Overall, these findings imply that HSV‐1 infection prevents monocyte activation, thus leading to a significant dysfunction of the monocyte‐mediated anti‐Candida response; HSV‐1 induced apoptosis and necrosis of monocytes further contribute to this impairment.