bluuebunny/crossref_metadata_2025 huggingface dataset:
Subinhibitory Concentrations of Protein Synthesis-Inhibiting Antibiotics Promote Increased Expression of the
agr
Virulence Regulator and Production of Phenol-Soluble Modulin Cytolysins in Community-Associated Methicillin-Resistant
Staphylococcus aureus
Authors: Joo Hwang-Soo , Chan June L. , Cheung Gordon Y. C. , Otto Michael
Published: August 2010

Tetracycline, clindamycin, and other protein synthesis inhibitors at subinhibitory concentrations significantly increased the expression of the pivotal virulence regulator
agr
and production of the
agr
-regulated cytolytic phenol-soluble modulins in the community-associated methicillin-resistant
Staphylococcus aureus
(CA-MRSA) strain USA300. Our results suggest that such protein synthesis inhibitors may exacerbate the progression of CA-MRSA disease when applied at concentrations that are too low or when treating infections caused by strains resistant to those antibiotics.
Population Pharmacokinetics and Pharmacodynamics of Artemether and Lumefantrine during Combination Treatment in Children with Uncomplicated Falciparum Malaria in Tanzania
Authors: Hietala Sofia Friberg , Mårtensson Andreas , Ngasala Billy , Dahlström Sabina , Lindegårdh Niklas , Annerberg Anna , Premji Zul , Färnert Anna , Gil Pedro , Björkman Anders , Ashton Michael
Published: August 2010

The combination of artemether (ARM) and lumefantrine is currently the first-line treatment of uncomplicated falciparum malaria in mainland Tanzania. While the exposure to lumefantrine has been associated with the probability of adequate clinical and parasitological cure, increasing exposure to artemether and the active metabolite dihydroartemisinin (DHA) has been shown to decrease the parasite clearance time. The aim of this analysis was to describe the pharmacokinetics and pharmacodynamics of artemether, dihydroartemisinin, and lumefantrine in African children with uncomplicated malaria. In addition to drug concentrations and parasitemias from 50 Tanzanian children with falciparum malaria, peripheral parasite densities from 11 asymptomatic children were included in the model of the parasite dynamics. The population pharmacokinetics and pharmacodynamics of artemether, dihydroartemisinin, and lumefantrine were modeled in NONMEM. The distribution of artemether was described by a two-compartment model with a rapid absorption and elimination through metabolism to dihydroartemisinin. Dihydroartemisinin concentrations were adequately illustrated by a one-compartment model. The pharmacokinetics of artemether was time dependent, with typical oral clearance increasing from 2.6 liters/h/kg on day 1 to 10 liters/h/kg on day 3. The pharmacokinetics of lumefantrine was sufficiently described by a one-compartment model with an absorption lag time. The typical value of oral clearance was estimated to 77 ml/h/kg. The proposed semimechanistic model of parasite dynamics, while a rough approximation of the complex interplay between malaria parasite and the human host, adequately described the early effect of ARM and DHA concentrations on the parasite density in malaria patients. However, the poor precision in some parameters illustrates the need for further data to support and refine this model.
TelA Contributes to the Innate Resistance of
Listeria monocytogenes
to Nisin and Other Cell Wall-Acting Antibiotics
Authors: Collins Barry , Joyce Susan , Hill Colin , Cotter Paul D. , Ross R. Paul
Published: August 2010

Nisin is a class I bacteriocin (lantibiotic), which is employed by the food and veterinary industries and exhibits potent activity against numerous pathogens. However, this activity could be further improved through the targeting and inhibition of factors that contribute to innate nisin resistance. Here we describe a novel locus,
lmo1967
, which is required for optimal nisin resistance in
Listeria monocytogenes
. The importance of this locus, which is a homologue of the tellurite resistance gene
telA
, was revealed after the screening of a
mariner
random mutant bank of
L. monocytogenes
for nisin-susceptible mutants. The involvement of
telA
in nisin resistance was confirmed through an analysis of a nonpolar deletion mutant. In addition to being 4-fold-more susceptible to nisin, the Δ
telA
strain was also 8-fold-more susceptible to gallidermin and 2-fold-more susceptible to cefuroxime, cefotaxime, bacitracin, and tellurite. This is the first occasion upon which
telA
has been investigated in a Gram-positive organism and also represents the first example of a link being established between a
telA
gene and resistance to cell envelope-acting antimicrobials.
Genetic and Functional Variability of AmpC-Type β-Lactamases from
Acinetobacter baumannii
Authors: Rodríguez-Martínez José-Manuel , Poirel Laurent , Nordmann Patrice
Published: August 2010

The incidence of naturally occurring AmpC β-lactamases with extended activities toward several cephalosporins was evaluated among 17 ceftazidime (CAZ)-resistant
Acinetobacter baumannii
isolates. Five AmpC β-lactamases (named ADC β-lactamases) were identified, among which those possessing the Val208Ala (inside the omega-loop) or Asn283Ser (helix H-10) substitution conferred higher levels of resistance (4- to 64-fold higher) to CAZ and to cefotaxime in
Escherichia coli
. This study demonstrates that peculiar AmpCs playing a role in resistance to broad-spectrum cephalosporins in
A. baumannii
may be identified.
Activity of the Histone Deacetylase Inhibitor FR235222 on
Toxoplasma gondii
: Inhibition of Stage Conversion of the Parasite Cyst Form and Study of New Derivative Compounds
Authors: Maubon Danièle , Bougdour Alexandre , Wong Yung-Sing , Brenier-Pinchart Marie-Pierre , Curt Aurélie , Hakimi Mohamed-Ali , Pelloux Hervé
Published: August 2010

Bradyzoite-to-tachyzoite conversion plays a role in the pathogenesis of recrudescence of ocular toxoplasmosis and disease in immunocompromised persons. The currently available medicines are ineffective on cysts and fail to prevent reactivation of latent toxoplasmosis. A previous study showed that the histone deacetylase inhibitor FR235222 has a dramatic effect on tachyzoite growth and induces tachyzoite-to-bradyzoite conversion
in vitro
. The present study shows that FR235222 can target
in vitro
-converted cysts and bradyzoites. Moreover, the compound is active on
ex vivo T. gondii
cysts. Free bradyzoites isolated after lysis of the cell wall did not proliferate
in vitro
when the cyst was treated with FR235222. The results imply that this compound is able to cross the
T. gondii
cystic cell wall. Fluorescent labeling shows that the compound impairs the capacity of the bradyzoites to convert without damaging the cyst wall integrity.
In vivo
inoculation of formerly treated cysts fails to infect mice when these cysts were treated with FR235222. We used our structural knowledge of FR235222 and its target,
T. gondii
HDAC3, to synthesize new FR235222 derivative compounds. We identified two new molecules that are highly active against tachyzoites. They harbor a better selectivity index that is more suitable for a future
in vivo
approach. These results identify FR235222 and its derivatives as new lead compounds in the range of therapeutics available for acute and chronic toxoplasmosis.
A Chimeric Protein That Functions as both an Anthrax Dual-Target Antitoxin and a Trivalent Vaccine
Authors: Wu Gaobing , Hong Yuzhi , Guo Aizhen , Feng Chunfang , Cao Sha , Zhang Cheng-Cai , Shi Ruiping , Tan Yadi , Liu Ziduo
Published: August 2010

Effective measures for the prophylaxis and treatment of anthrax are still required for counteracting the threat posed by inhalation anthrax. In this study, we first demonstrated that the chimeric protein LFn-PA, created by fusing the protective antigen (PA)-binding domain of lethal factor (LFn) to PA, retained the functions of the respective molecules. On the basis of this observation, we attempted to develop an antitoxin that targets the binding of lethal factor (LF) and/or edema factor (EF) to PA and the transportation of LF/EF. Therefore, we replaced PA in LFn-PA with a dominant-negative inhibitory PA (DPA), i.e., PA
F427D
. In
in vitro
models of anthrax intoxication, the LFn-DPA chimera showed 3-fold and 2-fold higher potencies than DPA in protecting sensitive cells against anthrax lethal toxin (LeTx) and edema toxin (EdTx), respectively. In animal models, LFn-DPA exhibited strong potency in rescuing mice from lethal challenge with LeTx. We also evaluated the immunogenicity and immunoprotective efficacy of LFn-DPA as an anthrax vaccine candidate. In comparison with recombinant PA, LFn-DPA induced significantly higher levels of the anti-PA immune response. Moreover, LFn-DPA elicited an anti-LF antibody response that could cross-react with EF. Mice immunized with LFn-DPA tolerated a LeTx challenge that was 5 times its 50% lethal dose. Thus, LFn-DPA represents a highly effective trivalent vaccine candidate for both preexposure and postexposure vaccination. Overall, we have developed a novel and dually functional reagent for the prophylaxis and treatment of anthrax.
The Initial 96 Hours of Invasive Pulmonary Aspergillosis: Histopathology, Comparative Kinetics of Galactomannan and (1→3)-β-
d
-Glucan, and Consequences of Delayed Antifungal Therapy
Authors: Hope William W. , Petraitis Vidmantas , Petraitiene Ruta , Aghamolla Tamarra , Bacher John , Walsh Thomas J.
Published: August 2010

Acute invasive pulmonary aspergillosis is a rapidly progressive and frequently lethal infection. Relatively little is known about early events in the pathogenesis and relationship between the cell wall biomarkers galactomannan and (1→3)-β-
d
-glucan. The consequences of delayed antifungal therapy are also poorly defined. A persistently neutropenic rabbit model of invasive pulmonary aspergillosis was used to describe the histopathology of early invasive pulmonary aspergillosis and the kinetics of galactomannan and (1→3)-β-
d
-glucan. The time course of both molecules was mathematically modeled by using a population methodology, and Monte Carlo simulations were performed. The effect of progressive delay in the administration of amphotericin B deoxycholate 1 mg/kg at 24, 48, 72, and 96 h postinoculation on fungal burden, lung weight, pulmonary infarct score, and survival was determined. Histopathology showed phagocytosis of conidia by pulmonary alveolar macrophages at 4 h postinoculation. At 12 to 24 h, there was a progressive focal inflammatory response with conidial germination and hyphal extension. Subsequently, hyphae invaded into the contiguous lung. Galactomannan and (1→3)-β-
d
-glucan had similar trajectories, and both exhibited considerable interindividual variability, which was reflected in Monte Carlo simulations. Concentrations of both molecules began to rise <24 h postinoculation before pulmonary hemorrhagic infarction was present. Delays of 72 and 96 h in the administration of amphotericin B resulted in fungal burdens and lung weights that were indistinguishable from those of controls, respectively. Galactomannan and (1→3)-β-
d
-glucan have similar kinetics and are comparable biomarkers of early invasive pulmonary aspergillosis. Antifungal treatment at ≥48 h postinoculation is associated with suboptimal therapeutic outcomes.
1-
O
-Hexadecyloxypropyl Cidofovir (CMX001) Effectively Inhibits Polyomavirus BK Replication in Primary Human Renal Tubular Epithelial Cells
Authors: Rinaldo Christine Hanssen , Gosert Rainer , Bernhoff Eva , Finstad Solrun , Hirsch Hans H.
Published: August 2010

Antiviral drugs for treating polyomavirus BK (BKV) replication in polyomavirus-associated nephropathy or hemorrhagic cystitis are of considerable clinical interest. Unlike cidofovir, the lipid conjugate 1-
O
-hexadecyloxypropyl cidofovir (CMX001) is orally available and has not caused detectable nephrotoxicity in rodent models or human studies to date. Primary human renal proximal tubular epithelial cells were infected with BKV-Dunlop, and CMX001 was added 2 h postinfection (hpi). The intracellular and extracellular BKV DNA load was determined by quantitative PCR. Viral gene expression was examined by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence microscopy. We also examined host cell viability, proliferation, metabolic activity, and DNA replication. The titration of CMX001 identified 0.31 μM as the 90% effective concentration (EC
90
) for reducing the extracellular BKV load at 72 hpi. BKV large T antigen mRNA and protein expression was unaffected at 24 hpi, but the intracellular BKV genome was reduced by 90% at 48 hpi. Late gene expression was reduced by 70 and 90% at 48 and 72 hpi, respectively. Comparisons of CMX001 and cidofovir EC
90
s from 24 to 96 hpi demonstrated that CMX001 had a more rapid and enduring effect on BKV DNA and infectious progeny at 96 hpi than cidofovir. CMX001 at 0.31 μM had little effect on overall cell metabolism but reduced bromodeoxyuridine incorporation and host cell proliferation by 20 to 30%, while BKV infection increased cell proliferation in both rapidly dividing and near-confluent cultures. We conclude that CMX001 inhibits BKV replication with a longer-lasting effect than cidofovir at 400× lower levels, with fewer side effects on relevant host cells
in vitro
.
Identification of Three Novel Superantigen-Encoding Genes inStreptococcus equisubsp.zooepidemicus,szeF,szeN, andszeP
Authors: Paillot Romain , Darby Alistair C. , Robinson Carl , Wright Nicola L. , Steward Karen F. , Anderson Emma , Webb Katy , Holden Matthew T. G. , Efstratiou Androulla , Broughton Karen , Jolley Keith A. , Priestnall Simon L. , Marotti Campi Maria C. , Hughes Margaret A. , Radford Alan , Erles Kerstin , Waller Andrew S.
Published: August 2010

The acquisition of superantigen-encoding genes byStreptococcus pyogeneshas been associated with increased morbidity and mortality in humans, and the gain of four superantigens byStreptococcus equiis linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogenStreptococcus equisubsp.zooepidemicus. A recent study determined that the culture supernatants of severalS. equisubsp.zooepidemicusstrains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel superantigen-encoding genes. The products ofszeF,szeN, andszePshare 59%, 49%, and 34% amino acid sequence identity with SPEH, SPEM, and SPEL, respectively. Recombinant SzeF, SzeN, and SzeP stimulated the proliferation of equine peripheral blood mononuclear cells, and tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) production,in vitro. Although none of these superantigen genes were encoded within functional prophage elements,szeNandszePwere located next to a prophage remnant, suggesting that they were acquired by horizontal transfer. Eighty-one of 165 diverseS. equisubsp.zooepidemicusstrains screened, including 7 out of 15 isolates from cases of disease in humans, contained at least one of these new superantigen-encoding genes. The presence ofszeNorszeP, but notszeF, was significantly associated with mitogenic activity in theS. equisubsp.zooepidemicuspopulation (P< 0.000001,P< 0.000001, andP= 0.104, respectively). We conclude that horizontal transfer of these novel superantigens from and within the diverseS. equisubsp.zooepidemicuspopulation is likely to have implications for veterinary and human disease.
Escherichia coli
Subtilase Cytotoxin Induces Apoptosis Regulated by Host Bcl-2 Family Proteins Bax/Bak
Authors: May Kerrie L. , Paton James C. , Paton Adrienne W.
Published: August 2010

Subtilase cytotoxin (SubAB) was first isolated from a Shiga toxigenic
Escherichia coli
(STEC) strain that was responsible for an outbreak of hemolytic-uremic syndrome and is the prototype of a new family of AB
5
cytotoxins. SubAB is a subtilase-like serine protease, and upon uptake by host cells, it is trafficked to the endoplasmic reticulum (ER), where it cleaves the essential ER chaperone BiP (GRP78) with high specificity. Previous work has shown that BiP cleavage by SubAB initiates ER stress-signaling pathways in host cells that eventuate in cell death associated with DNA fragmentation, a hallmark of apoptosis. The present study has investigated the role of the Bcl-2 protein family, which has been shown to regulate ER stress-induced apoptosis in other model systems. Examination of the cytotoxicity of SubAB for wild-type and
bax
−/−
/
bak
−/−
mouse embryonic fibroblasts and comparison of apoptotic markers in these cells revealed that SubAB cytotoxicity can be predominantly attributed to the activation of apoptotic pathways activated by Bax/Bak. The results of the present study further our understanding of the molecular mechanism whereby SubAB kills eukaryotic cells and contributes to STEC pathogenesis, in addition to consolidating the roles of Bcl-2 family members in the regulation of ER stress-induced apoptosis.
Morality and moral conflicts in hospice care: results of a qualitative interview study: Table 1
Authors: Salloch Sabine , Breitsameter Christof
Published: August 2010

Hospices consider themselves places that practise a holistic form of terminal care, encompassing physical and psychological symptoms, and also the social and spiritual support for a dying patient. So far, the underlying ethical principles have been treated predominantly in terms of a normative theoretical discussion. The interview study discussed in this paper is a qualitative investigation into general and hospice-related conceptions of morality among full-time and voluntary workers in German inpatient hospices. It examines moral conflicts and efforts leading to their solution. The main ideas identified include moral neutrality towards the patients and their requests, the capability of acceptance, the idea of self-restraint with respect to the dying patient and the principle of respect for the natural course of dying. Essential triggers for moral conflicts were the inadequate education of patients, problems of acceptance in view of incurable disease, and disagreements between members of patients' families. The interviewees expressed their scepticism towards formal institutions of ethical counselling. The study has shown a type of virtue ethics that forms an integral part of the overall concept of hospice care, which cannot be treated separately from a holistic idea of care at the end of life.
Parental attitudes towards and perceptions of their children's participation in clinical research: a developing-country perspective
Authors: Nabulsi Mona , Khalil Yvette , Makhoul Jihad
Published: August 2010

Background

Paediatric clinical research faces unique challenges that compromise optimal recruitment of children into clinical trials. A main barrier to enrolment of children is parental misconceptions about the research process. In developing countries, there is a knowledge gap regarding parental perceptions of and attitudes towards their children's participation in clinical trials.

Objective

To explore such perceptions and attitudes in Lebanese parents.

Study design

33 in-depth interviews were conducted with parents with and without previous research experience. Interviews were tape-recorded, transcribed in colloquial Arabic, and later subjected to thematic analysis.

Results

Benefit/risk ratio assessment was a major determinant of parental consent. Fear of adverse events or painful procedures in research was a recurring theme in most interviews. Whereas perception of direct benefit to the child, trust in the physician or institution, financial gains or having a positive previous experience in research facilitated consent, a complex informed consent form and misunderstanding of the term ‘randomisation’ hindered parental approval of participation.

Conclusion

Lebanese parents have perceptions of and attitudes towards children's participation in clinical trials that are similar to those reported from the industrialised world. Improving communication with parents and building trust between researchers and parents is important for successful recruitment. Investigators planning to conduct paediatric trials in developing countries need to simplify consent forms and devise new ways to explain randomisation.
The use of vignettes within a Delphi exercise: a useful approach in empirical ethics?
Authors: Wainwright Paul , Gallagher Ann , Tompsett Hilary , Atkins Christine
Published: August 2010

There has been an increase in recent years in the use of empirical methods in healthcare ethics. Appeals to empirical data cannot answer moral questions, but insights into the knowledge, attitudes, experience, preferences and practice of interested parties can play an important part in the development of healthcare ethics. In particular, while we may establish a general ethical principle to provide explanatory and normative guidance for healthcare professionals, the interpretation and application of such general principles to actual practice still requires interpretation and judgement. And many situations in healthcare practice are complex and may involve a variety of principles, each of which may conflict with the others. Simple surveys or interview studies may not be sufficient if we wish to develop a nuanced approach to ethical practice that can be set out in guidelines, codes or directives. We do not resolve moral questions by plebiscite. In this paper, the authors argue for the use of consensus methods to develop shared understanding of ethical practice, and they argue further for the combination of the Delphi method with the use of vignettes to illustrate the kind of situations that may occur in practice. They develop their argument in part by reference to their experience of using this approach in their recent research.
An architectural approach to the growth forms of Nothofagus pumilio (Nothofagaceae) along an altitudinal gradient
Authors: Stecconi Marina , Puntieri Javier G. , Barthélémy Daniel
Published: August 2010

Variations in the architecture and axis structure of different growth forms of Nothofagus pumilio (Poepp. et Endl.) Krasser (Nothofagaceae) were studied along an altitudinal gradient. We evaluated the primary growth and branching pattern of annual shoots belonging to the main axis categories (trunk, main branches, and secondary (short) branches) of four growth forms developed at different altitudes (1200–1600 m a.s.l.) in northern Patagonia: (i) low shrubs at the high-altitude timberline, (ii) high shrubs at high altitude, (iii) low trees at mid-altitude slopes, and (iv) high trees at low-altitude single-species forests. Shoot structure and branch distribution along shoots were similar for all axis categories and growth forms. Significant differences between axis categories were found regarding the sizes of shoots, which decreased from trunk to secondary/short branches. For each axis category, shoots of similar size differed between growth forms in stem slenderness and internode length. The extent of differentiation between axis categories is key in the structural distinction between growth forms of N. pumilio.
Genetic diversity of mocó cotton (Gossypium hirsutumracemarie-galante) from the northeast of Brazil: implications for conservation
Authors: Pinto de Menezes Ivandilson Pessoa , Barroso Paulo Augusto Vianna , Hoffmann Lúcia Vieira , Lucena Valeska Silva , Giband Marc
Published: August 2010

Mocó cotton ( Gossypium hirsutum  L. race marie-galante (Watt) Hutch.) is a potential source of valuable alleles for breeding programs, mainly because of its great adaptability to semi-arid conditions. With the aim of quantifying mocó cotton genetic variability, 187 plants collected in the northeast of Brazil were evaluated using 12 microsatellite markers. A total of 62 alleles were amplified, ranging from three to eight polymorphic alleles per locus. Total genetic diversity was high (0.52), and when measured on a per state basis, was of 0.37 on average. The population showed a low level of heterozygozity (HO= 0.16), reflecting a high level of endogamy (FIS= 0.67). Phylogenetic analysis using the neighbor-joining method revealed that plants sampled in different states tended to cluster according to their geographic origin, except for those collected in the states of Paraíba and Rio Grande do Norte, which grouped together. Plants from the state of Piauí formed two groups, one with an apparent allelic contribution from G. barbadense, while the second group of plants was closer to those from the states of Paraíba and Rio Grande do Norte. Despite the high genetic diversity that was observed in the remaining populations, urgent conservation efforts should be undertaken, owing to the high level of endogamy and accelerated extinction process that characterizes these populations. Such efforts should focus on the collection and ex situ maintenance of representative genetic diversity.
Density dependence in an experimental boreal forest understory community
Authors: Treberg Michael A. , Turkington Roy
Published: August 2010

Density-dependent regulation in plants may occur at the level of the entire community and may differ in magnitude and direction at different life history stages such as germination, survival and growth, and under different abiotic conditions. We constructed semi-natural communities of boreal forest understory species planting 10 of the most abundant species. The experimental communities were established from seed or from cuttings and grown in sandboxes at six densities that extended far above and below average natural field density, while maintaining constant relative species proportions (a community density series (CDS)). We used two watering and fertilization levels in a factorial design. At the community level, both emergence and final per-plant shoot mass were negatively density dependent, while survival to the end of the season was facilitative. The effect of water was positive at seed emergence, whereas fertilizer negatively affected survival. Species-specific responses were also dependent on life stage. We demonstrated that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify the effects of plant competition at the community and species levels, and to determine whether the importance of these biotic interactions depend on abiotic factors.
Leaflet initiation is temporally and spatially separated in simple and complex tomato (Solanum lycopersicum) leaf mutants: a developmental analysis
Authors: Kang Julie , Sinha Neelima R.
Published: August 2010

Formation of a compound leaf requires the involvement of multiple factors, including KNOX1 gene expression. To further characterize simple and complex tomato leaf mutants, we analyzed their morphology and development by assessing: leaf phenotypes, primary leaf morphogenesis, expression of the class I KNOX gene LeT6, and meristematic activity of the marginal blastozone. Mutants with alterations in lobing and (or) pinnation (decrease/increase) were analyzed. Primary leaflet initiation is delayed in mutants with decreased lobing. In contrast, leaflet initiation is advanced or similar to the wild type in mutants with deep lobes. Leaves with increased pinnation along the rachis require a protracted developmental program to form their final leaf morphology. Using a morphometric analysis, we show that leaf complexity can be quantified. The expression pattern of LeT6 correlates with histological analysis of meristematic activity of the marginal blastozone, suggesting that LeT6 may play a role, through some unknown mechanism, to regulate meristematic competence, not only in the marginal blastozone to regulate leaflet lobing, but along the entire length of the leaf to regulate pinnation in compound leaves.
Detecting and correcting underreported catches in fish stock assessment: trial of a new method
Authors: Bousquet Nicolas , Cadigan Noel , Duchesne Thierry , Rivest Louis-Paul
Published: August 2010

Landings from fisheries are often underreported, that is, the true landings are greater than those reported. Despite this bias, reported landings are widely used in fish stock assessments, and this might lead to overoptimistic exploitation strategies. We construct a statistical stock assessment model that accounts for underreported landings using the theory of censoring with sequential population analysis (SPA). The new model is developed and implemented specifically for the cod stock ( Gadus morhua ) from the southern Gulf of St. Lawrence (Canada). This stock is known to have unreported overfishing during 1985–1992. We show in simulations that for this stock, the new censored model can correctly detect the problematic landings. These corrections are nearly insensitive to subjective boundaries placed on real catches and robust to modifications imposed in the simulation of landings. However, when surveys are too noisy, the new SPA for censored catches can result in increased uncertainty in parameters used for management such as spawning stock biomass and age-structured stock size.
Nutrient loading by anadromous alewife (Alosa pseudoharengus): contemporary patterns and predictions for restoration efforts
Authors: West Derek C. , Walters Annika W. , Gephard Stephen , Post David M.
Published: August 2010

Anadromous alewives ( Alosa pseudoharengus ) have the potential to alter the nutrient budgets of coastal lakes as they migrate into freshwater as adults and to sea as juveniles. Alewife runs are generally a source of nutrients to the freshwater lakes in which they spawn, but juveniles may export more nutrients than adults import in newly restored populations. A healthy run of alewives in Connecticut imports substantial quantities of phosphorus; mortality of alewives contributes 0.68 g P·fish–1, while surviving fish add 0.18 g P, 67% of which is excretion. Currently, alewives contribute 23% of the annual phosphorus load to Bride Lake, but this input was much greater historically, with larger runs of bigger fish contributing 2.5 times more phosphorus in the 1960s. A mesocosm experiment in a nearby lake showed that juvenile alewife growth is strongly density dependent, but early survival may be too low for juvenile outmigration to balance adult inputs. In eutrophic systems where nutrients are a concern, managers can limit nutrient loading by capping adult returns at a level where juvenile populations would not be suppressed.
Trends in the abundance of marine fishes
Authors: Hutchings Jeffrey A. , Minto Cóilín , Ricard Daniel , Baum Julia K. , Jensen Olaf P.
Published: August 2010

The Convention on Biological Diversity (CBD) established a target in 2002 to reduce the rate of biodiversity loss by 2010. Using a newly constructed global database for 207 populations (108 species), we examine whether the 2010 target has been met for marine fishes, while accounting for population biomass relative to maximum sustainable yield, BMSY. Although rate of decline has eased for 59% of populations declining before 1992 (a pattern consistent with a literal interpretation of the target), the percentage of populations below BMSY has remained unchanged and the rate of decline has increased among several top predators, many of which are below 0.5BMSY. Combining population trends, a global multispecies index indicates that marine fishes declined 38% between 1970 and 2007. The index has been below BMSY since the mid-1980s and stable since the early 1990s. With the exception of High Seas pelagic fishes and demersal species in the Northeast Pacific and Australia – New Zealand, the multispecies indices are currently below BMSY in many regions. We conclude that the 2010 CBD target represents a weak standard for recovering marine fish biodiversity and that meaningful progress will require population-specific recovery targets and associated time lines for achieving those targets.
Iterative solution of non-autonomous Bloch equations: fluorescence spectrum with detuned squeezed vacuum field
Authors: Batarfi H. A. , Al-Harbi R. A. , Saunders R. , Hassan S. S.
Published: August 2010

The non-autonomous Bloch equations modelling a driven 2-level atom in the presence of an off-resonant broadband squeezed vacuum (SV) field is treated analytically. This concerns iterative solutions valid for large SV detuning parameter but for arbitrary strength of the laser field. Computational results are presented for the averaged atomic variables for various data and compared with the resonant SV field case. The iterated analytical results for nonzero SV detuning are compared with the (exact) numerical solutions of the Bloch equations, hence we have an insight about the range of other system parameters (other than the Rabi frequency) for which the iterated solutions are valid to O(10−2) or less. The main purpose of deriving these analytical results is to calculate analytically the transient fluorescent spectrum. For an initially ground-state atom, both the SV phase and detuning parameters induce pronounced asymmetrical spectrum in the strong field case.
Investigations of lithium-chloro-borate glass-ceramic and its elastic properties
Authors: Shivaprakash Y. , Anavekar R. V.
Published: August 2010

Elastic properties and microstructural studies of 0.3Li2O-0.2LiCl-0.5B2O3 glass-ceramics have been carried out for a precursor glass prepared using the rapid melt quenching technique. Quenched glasses were heat treated (by three step process) at 150 °C for 2, 4, 6, and 8 h. Scanning electron microscopy and X-ray diffraction studies clearly indicate gradual growth of different phases in the glass matrix with increasing time of heat-treatment. IR studies reveal the structural modification in the network as the precursor glass transformed into glass-ceramic. Elastic properties have been measured by performing ultrasonic wave velocity measurements at a frequency of 10 MHz. Longitudinal and shear moduli of the samples tend to increase with heat-treatment time. However, the bulk modulus is almost insensitive to heat treatment. The Debye temperature was found to increase, and the Poisson ratio lies in the range 0.2–0.3 (typical for covalently bonded networks) with an increase in heat-treatment time.
BOUNDS ON f(G) GRAVITY FROM ENERGY CONDITIONS
Authors: WU PUXUN , YU HONGWEI
Published: August 2010

The f(G) gravity is a theory to modify the general relativity and it can explain the present cosmic accelerating expansion without the need of dark energy. In this paper the f(G) gravity is tested with the energy conditions. Using the Raychaudhuri equation along with the requirement that the gravity is attractive in the FRW background, we obtain the bounds on f(G) from the SEC and NEC. These bounds can also be found directly from the SEC and NEC within the general relativity context by the transformations: ρ → ρm + ρE and p → pm + pE, where ρE and pE are the effective energy density and pressure in the modified gravity. With these transformations, the constraints on f(G) from the WEC and DEC are obtained. Finally, we examine two concrete examples with WEC and obtain the allowed region of model parameters.
LHC Z' DISCOVERY POTENTIAL FOR MODELS WITH CONTINUOUSLY DISTRIBUTED MASS
Authors: KRASNIKOV N. V.
Published: August 2010

We study the Large Hadron Collider (LHC) discovery potential for Z' models with continuously distributed mass for [Formula: see text], 10 and 14 TeV center-of-mass energies. One of the possible LHC signatures for such models is the existence of broad resonance structure in Drell–Yan reaction pp →Z' + ⋯→l+l- + ⋯.
COMMENTS ON DIHEDRAL AND SUPERSYMMETRIC EXTENSIONS OF A FAMILY OF HAMILTONIANS ON A PLANE
Authors: QUESNE C.
Published: August 2010

For any odd k, a connection is established between the dihedral and supersymmetric extensions of the Tremblay–Turbiner–Winternitz Hamiltonians Hk on a plane. For this purpose, the elements of the dihedral group D2k are realized in terms of two independent pairs of fermionic creation and annihilation operators and some interesting trigonometric identities are demonstrated.
B MESON RADIATIVE EFFECTIVE NEUTRAL CURRENT ("PENGUIN") TRANSITION RATES
Authors: SCHUMM BRUCE A.
Published: August 2010

B meson radiative effective neutral current ("penguin") decays rates, including the b → sγ and b → dγ transitions, represent one of the most powerful indirect constraints on new physics scenarios. Approaches to the measurements of the b → sγ width are presented, and the combined result is compared to its Standard-Model expectation. Various approaches to studying the b → dγ transition involve a comparison to corresponding b → sγ processes, and are presented in terms of the extracted ratio of CKM coupling parameters |Vtd/Vts|, which is precisely constrained within the context of the Standard Model by measurements of B meson mixing. The relative accuracy of experimental constraints on radiative penguin transition rates are better than ±7% for b → sγ and ±20% for b → dγ/b → sγ. The implications of the increasingly precise complementary constraint on |Vtd/Vts| that arises from the measurement radiative penguin decay widths may not yet be fully appreciated. There is significant potential for the improvement of these constraints in both the near (particularly for b → sγ) and longer terms.
RF doppler shift-based mobile sensor tracking and navigation
Authors: Kusý Branislav , Amundson Isaac , Sallai Janos , Völgyesi Peter , Lédeczi Akos , Koutsoukos Xenofon
Published: August 2010

Mobile wireless sensors require position updates for tracking and navigation. We present a localization technique that uses the Doppler shift in radio transmission frequency observed by stationary sensors. We consider two scenarios. In the first, the mobile node is carried by a person. In the second, the mobile node controls a robot. In both approaches the mobile node transmits an RF signal, and infrastructure nodes measure the Doppler-shifted frequency. Such measurements enable us to calculate the position and velocity of the mobile transmitter. Our experimental results demonstrate that this technique is viable and accurate for resource-constrained mobile sensor tracking and navigation.
Speed control and scheduling of data mules in sensor networks
Authors: Sugihara Ryo , Gupta Rajesh K.
Published: August 2010

Unlike traditional multihop forwarding among stationary sensor nodes, use of mobile devices for data collection in wireless sensor networks has recently been gathering more attention. The use of mobility significantly reduces the energy consumption at sensor nodes, elongating the functional lifetime of the network. However, a drawback is an increased data delivery latency. Reducing the latency through optimizing the motion of data mules is critical for this approach to thrive. In this article, we focus on the problem of motion planning, specifically, determination of the speed of the data mule and the scheduling of the communication tasks with the sensors. We consider three models of mobility capability of the data mule to accommodate different types of vehicles. Under each mobility model, we design optimal and heuristic algorithms for different problems: single data mule case, single data mule with periodic data generation case, and multiple data mules case. We compare the performance of the heuristic algorithm with a naive algorithm and also with the multihop forwarding approach by numerical experiments. We also compare one of the optimal algorithms with a previously proposed method to see how our algorithm improves the performance and is also useful in practice. As far as we know, this study is the first of a kind that provides a systematic understanding of the motion planning problem of data mules.
Reliable and efficient reprogramming in sensor networks
Authors: Miller Chris , Poellabauer Christian
Published: August 2010

Retasking and remote programming of sensor networks is an essential functionality to make these networks practical and effective. As the availability of more capable sensor nodes increases and new functional implementations continue to be proposed, these large collections of wireless nodes will need the ability to update and upgrade the software packages they are running. In order to do this, the new binary file must be distributed to all nodes in the network. Making a physical connection with each individual node is impractical in large wireless networks. Standard flooding mechanisms are too energy-costly and computationally expensive and they may interfere with the network's current tasks. A reliable method for distributing new code or binary files to every node in a wireless sensor network is needed. We propose a reprogramming/retasking framework for sensor networks that is energy efficient, responsive, and reliable, while maintaining a stable network.
Algorithm Visualization
Authors: Shaffer Clifford A. , Cooper Matthew L. , Alon Alexander Joel D. , Akbar Monika , Stewart Michael , Ponce Sean , Edwards Stephen H.
Published: August 2010

We present findings regarding the state of the field of Algorithm Visualization (AV) based on our analysis of a collection of over 500 AVs. We examine how AVs are distributed among topics, who created them and when, their overall quality, and how they are disseminated. There does exist a cadre of good AVs and active developers. Unfortunately, we found that many AVs are of low quality, and coverage is skewed toward a few easier topics. This can make it hard for instructors to locate what they need. There are no effective repositories of AVs currently available, which puts many AVs at risk for being lost to the community over time. Thus, the field appears in need of improvement in disseminating materials, propagating known best practices, and informing developers about topic coverage. These concerns could be mitigated by building community and improving communication among AV users and developers.
Nonlinear Filtering for Hybrid GPS/GSM Mobile Terminal Tracking
Authors: Fritsche Carsten , Klein Anja
Published: August 2010

The Global Positioning System (GPS) has become one of the state-of-the-art location systems that offers reliable mobile
terminal (MT) location estimates. However, there exist situations where GPS is not available, for example, when the MT is used indoors or when the MT is located close to high buildings. In these scenarios, a promising approach is to combine the GPS-measured values with measured values from the Global System for Mobile Communication (GSM), which is known as hybrid localization method. In this paper, three nonlinear filters, namely, an extended Kalman filter, a Rao-Blackwellized unscented Kalman filter, and a modified version of the recently proposed cubature Kalman filter, are proposed that combine pseudoranges from GPS with
timing advance and received signal strengths from GSM. The three filters are compared with each other in terms of performance and computational complexity. Posterior Cramér-Rao lower bounds are evaluated in order to assess the theoretical performance. Furthermore, it is investigated how additional GPS reference time information available from GSM influences the performance of the hybrid localization method. Simulation and experimental results show that the proposed hybrid method outperforms the GSM method.
Parameterless-Growing-SOM and Its Application to a Voice Instruction Learning System
Authors: Kuremoto Takashi , Komoto Takahito , Kobayashi Kunikazu , Obayashi Masanao
Published: August 2010

An improved self-organizing map (SOM), parameterless-growing-SOM (PL-G-SOM), is proposed in this paper. To overcome problems existed in traditional SOM (Kohonen, 1982), kinds of structure-growing-SOMs or parameter-adjusting-SOMs have been invented and usually separately. Here, we combine the idea of growing SOMs (Bauer and Villmann, 1997; Dittenbach et al. 2000) and a parameterless SOM (Berglund and Sitte, 2006) together to be a novel SOM named PL-G-SOM to realize additional learning, optimal neighborhood preservation, and automatic tuning of parameters. The improved SOM is applied to construct a voice instruction learning system for partner robots adopting a simple reinforcement learning algorithm. User's instructions of voices are classified by the PL-G-SOM at first, then robots choose an expected action according to a stochastic policy. The policy is adjusted by the reward/punishment given by the user of the robot. A feeling map is also designed to express learning degrees of voice instructions. Learning and additional learning experiments used instructions in multiple languages including Japanese, English, Chinese, and Malaysian confirmed the effectiveness of our proposed system.
Randomized Trial of a Pharmacist-Delivered Intervention for Improving Lipid-Lowering Medication Adherence among Patients with Coronary Heart Disease
Authors: Ma Yunsheng , Ockene Ira S. , Rosal Milagros C. , Merriam Philip A. , Ockene Judith K. , Gandhi Pritesh J.
Published: August 2010

A randomized trial of a pharmacist-delivered intervention (PI) versus usual care (UC) was conducted; 689 subjects with known coronary heart disease were recruited from cardiac catheterization laboratories. Participants in the PI condition received 5 pharmacist-delivered telephone counseling calls post-hospital discharge. At one year, 65% in the PI condition and 60% in the UC condition achieved an LDL-C level<100 mg/dL (P=.29); mean statin adherence was 0.88 in the PI, and 0.90 in the UC (P=.51). The highest percentage of those who reached the LDL-C goal were participants who used statins as opposed to those who did not use statins (67% versus 58%,P=.05). However, only 53% and 56% of the patients in the UC and PI conditions, respectively, were using statins. We conclude that a pharmacist-delivered intervention aimed only at improving patient adherence is unlikely to positively affect outcomes. Efforts must be oriented towards influencing physicians to increase statin prescription rates.
Renal Manifestations in Scleroderma: Evidence for Subclinical Renal Disease as a Marker of Vasculopathy
Authors: Shanmugam Victoria K. , Steen Virginia D.
Published: August 2010

Scleroderma is a disease characterized by immune activation, vasculopathy, fibroblast stimulation, and connective tissue fibrosis. End-organ damage occurs due to progressive tissue fibrosis and vasculopathy. Markers of incipient vasculopathy have not been well studied in scleroderma. However, reduced renal functional reserve and proteinuria are common indicators of progressive vasculopathy in diabetic and hypertensive vasculopathy. Recent studies suggest a strong association between renal involvement and outcomes in scleroderma, with a threefold increased risk of mortality from pulmonary hypertension if renal insufficiency is present. We review the types of renal involvement seen in scleroderma and the data to support the use of renal parameters including proteinuria, glomerular filtration rate, and renal vascular dynamics measured with Doppler ultrasound to identify subclinical renal insufficiency. Further studies are warranted to investigate the use of renal parameters as prognostic indicators in scleroderma.
An Evolutionary Video Assignment Optimization Technique for VOD System in Heterogeneous Environment
Authors: Ho King-Man , Poon Wing-Fai , Lo Kwok-Tung
Published: August 2010

We investigate the video assignment problem of a hierarchical Video-on-Demand (VOD) system in heterogeneous environments where different quality levels of videos can be encoded using either replication or layering. In such systems, videos are delivered to clients either through a proxy server or video broadcast/unicast channels. The objective of our work is to determine the appropriate coding strategy as well as the suitable delivery mechanism for a specific quality level of a video such that the overall system blocking probability is minimized. In order to find a near-optimal solution for such a complex video assignment problem, an evolutionary approach based on genetic algorithm (GA) is proposed. From the results, it is shown that the system performance can be significantly enhanced by efficiently coupling the various techniques.