bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of the Evaluation of 47 Drug Abuse Prevention Curricula Available Nationally
Authors: Dusenbury Linda , Falco Mathea , Lake Antonia
Published: October 2009

ABSTRACT: This review determined how many drug prevention curricula available to schools have been shown in rigorous research studies to reduce substance use behavior. Forty‐seven curricula which met the following criteria were included: 1) they focused on primary prevention of alcohol and/or drug use, 2) they were classroom‐based curricula designed for any grade level P‐12, 3) they were nationally and currently available, and 4) program distributors were willing to provide samples of curriculum materials to determine drug abuse prevention content. Of the 47 drug abuse prevention curricula identified, 10 (21%) had been subjected to sufficiently rigorous evaluations. At least eight of the 10 programs have been shown effective at reducing tobacco or drug use, in at least some studies. The remaining two programs did not appear to have sustained effects on drug use, although they had variable success at reducing substance use early on. One of the 10 programs has been shown to have positive effects lasting into young adulthood. Six of the 10 curricula have been shown to have effects lasting for at least two years after the pretest. Two curricula have not been evaluated beyond the post‐test, so it is impossible to know whether their effectiveness will last. Recommendations to increase the number of programs rigorously evaluated are offered.
How Prospective School Health Educators Can Build a Portfolio to Communicate Professional Expertise
Authors: Cleary Michael J. , Birch David A.
Published: October 2009

ABSTRACT: Portfolios — purposeful and selective collections of authentic evidence regarding teaching and learning — occur increasingly in K‐12 classroom, preservice teacher education, and university initiatives to enhance teaching effectiveness of faculty. In addition to being used to improve instruction, portfolios can help teacher candidates with initial employment. This article describes an organized set of materials prospective school health educators should develop to accurately represent their newly acquired skills and competencies. (J Sch Health. 1997;67(6):228–231)
Adolescent Weight Management and Perceptions: An Analysis of the National Longitudinal Study of Adolescent Health
Authors: Kilpatrick Marcus , Ohannessian Christine , Bartholomew John B.
Published: October 2009

ABSTRACT: Researchers investigated contemporary weight management activities and weight perceptions among adolescents and determined the effects of school health education on these perceptions and activities. This national, random sample of more than 6,500 adolescents (grades 7–12) measured perceived weight, weight change efforts, weight change activities. Body Mass Index, and health education for weight management. Results indicate that most adolescents: 1) take part in efforts to manage their weight, although many struggle with perceiving their weight; 2) engage in appropriate weight change efforts; and 3) report receiving school health education that positively effects some aspects of their weight management behavior. Thus, adolescents are concerned about weight and perceptions of weight and are engaging in a variety of weight change activities for weight maintenance and weight change. School health education appears to have some effect in improving adolescent health behavior, and discussion centers on this topic.
Ontario, Canada, High School Teachers as Enforcers in the War on Drugs: What Their Students See and Say
Authors: Warner Jessica , Albanes Ricardo , Amitay Oren
Published: October 2009

This paper examines how high school teachers interact with students on the subject of marijuana. Results, based on 49 focus groups with 278 high school students in Ontario, Canada, reveal three basic assumptions of the students: 1) only some teachers can actually tell when a student is high on marijuana; 2) many teachers have tried marijuana or continue to use it; and 3) individual teachers vary in how they respond to students who are high. Results suggest that changes in the relationship between marijuana and authority account in large part for the seeming reluctance of so many teachers to exercise their mandate to discipline students who use marijuana. The reasons for this are twofold: 1) many teachers do not see use of marijuana of and by itself as a threat to their authority; and 2) teachers who choose to confront users run the risk of having their authority and independence of action undermined once they report infractions to administrators who have authority over teachers and students alike.
Reflections on Two Decades of Research on Teen Sexual Behavior and Pregnancy
Authors: Kirby Douglas
Published: October 2009

ABSTRACT: During the past 20 years, both researchers and program developers made great progress in their efforts to reduce adolescent unprotected sex and prevent teen pregnancy. Research studies are now more likely to employ experimental designs with random assignment, to have large sample sizes with adequate statistical power, to measure actual sexual and contraceptive behaviors, to measure longer term effects, to employ proper statistical methods, and to report results in an unbiased manner. As a result of this body of research, large advances have occurred in our understanding of: 1)the incidence of teen pregnancy and its consequences; 2) the effects of improving adolescent knowledge, increasing access to contraception, and improving parent/child communication; and 3) the characteristics of effective programs. The on‐going evaluation of sex and HIV education programs coupled with creativity and perseverance on the part of program developers led to two groups of effective programs — sex and HIV education programs that reduce sexual risk‐taking behavior, and youth development programs that reduce teen‐age pregnancy and childbearing.
Children with Diabetes: Perceptions of Supports for Self‐Management at School
Authors: Nabors Laura , Lehmkuhl Heather , Christos Nicole , Andreone Teresa L.
Published: October 2009

ABSTRACT: Diabetes affects many children. Researchers know little about children's perceptions of what type of support they need at school, which was a focus of this study. Group interviews and surveys examined children's perceptions of support in caring for their diabetes (type I diabetes) from school nurses, teachers, and friends. Results indicated the children felt supported at school, but improved flexibility by teachers and nurses (eg, let me keep my meter with me always) and individualized care plans may improve their ability to manage their diabetes at school. Participating in after‐school activities may be difficult for middle school youth. Children reported they needed additional help and support to cope with hypoglycemic episodes.
Modeling the Spatially Varying Water Balance Processes in a Semiarid Mountainous Watershed of Idaho1
Authors: Stratton Benjamin T. , Sridhar Venakataramana , Gribb Molly M. , McNamara James P. , Narasimhan Balaji
Published: October 2009

Stratton, Benjamin T., Venakataramana Sridhar, Molly M. Gribb, James P. McNamara, and Balaji Narasimhan, 2009. Modeling the Spatially Varying Water Balance Processes in a Semiarid Mountainous Watershed of Idaho. Journal of the American Water Resources Association (JAWRA) 45(6):1390‐1408.

Abstract:  The distributed Soil Water Assessment Tool (SWAT) hydrologic model was applied to a research watershed, the Dry Creek Experimental Watershed, near Boise Idaho to investigate its water balance components both temporally and spatially. Calibrating and validating SWAT is necessary to enable our understanding of the water balance components in this semiarid watershed. Daily streamflow data from four streamflow gages were used for calibration and validation of the model. Monthly estimates of streamflow during the calibration phase by SWAT produced satisfactory results with a Nash Sutcliffe coefficient of model efficiency 0.79. Since it is a continuous simulation model, as opposed to an event‐based model, it demonstrated the limited ability in capturing both streamflow and soil moisture for selected rain‐on‐snow (ROS) events during the validation period between 2005 and 2007. Especially, soil moisture was generally underestimated compared with observations from two monitoring pits. However, our implementation of SWAT showed that seasonal and annual water balance partitioning of precipitation into evapotranspiration, streamflow, soil moisture, and drainage was not only possible but closely followed the trends of a typical semiarid watershed in the intermountain west. This study highlights the necessity for better techniques to precisely identify and drive the model with commonly observed climatic inversion‐related snowmelt or ROS weather events. Estimation of key parameters pertaining to soil (e.g., available water content and saturated hydraulic conductivity), snow (e.g., lapse rates, melting), and vegetation (e.g., leaf area index and maximum canopy index) using additional field observations in the watershed is critical for better prediction.
Methanotrophic symbioses in marine invertebrates
Authors: Petersen Jillian M. , Dubilier Nicole
Published: October 2009

Symbioses between marine animals and aerobic methane‐oxidizing bacteria are found at hydrothermal vents and cold seeps in the deep sea where reduced, methane‐rich fluids mix with the surrounding oxidized seawater. These habitats are ‘oases’ in the otherwise nutrient‐poor deep sea, where entire ecosystems are fueled by microbial chemosynthesis. By associating with bacteria that gain energy from the oxidation of CH4 with O2, the animal host is indirectly able to gain nutrition from methane, an energy source that is otherwise only available to methanotrophic microorganisms. The host, in turn, provides its symbionts with continuous access to both electron acceptors and donors that are only available at a narrow oxic – anoxic interface for free‐living methanotrophs. Symbiotic methane oxidizers have resisted all attempts at cultivation, so that all evidence for these symbiotic associations comes from ultrastructural, enzymatic, physiological, stable isotope and molecular biological studies of the symbiotic host tissues. In this review, we present an overview of the habitats and invertebrate hosts in which symbiotic methane oxidizers have been found, and the methods used to investigate these symbioses, focusing on the symbioses of bathymodiolin mussels that have received the most attention among methanotrophic associations.
Fuel Cell/Gas Turbine Hybrid System Control for Daily Load Profile and Ambient Condition Variation
Authors: Roberts Rory A. , Brouwer Jack , Samuelsen G. Scott
Published: October 2009

Fuel Cell/Gas Turbine (FC/GT) hybrid technology is promising, but introduces challenges in system operation and control. For base-load applications, changes in ambient conditions perturb the system and it becomes difficult to maintain constant power production by the FC/GT system. If the FC/GT hybrid system is load-following, then the problem becomes even more complex. In the current study, a dynamic model of a FC/GT power plant is developed with system controls. Two cases are evaluated: (1) system controls are developed to maintain constant power and process control within acceptable constraints and (2) the FC/GT power plant is set in power following mode connected in parallel to the grid for a daily load profile scenario. Changing ambient conditions are employed in the dynamic analysis for both cases. With appropriate attention to design of the system itself and the control logic, the challenges for dynamic system operation and control can be addressed.
Effect of Experimental Conditions on Gas Core Length and Downward Velocity of Free Surface Vortex in Cylindrical Vessel
Authors: Monji Hideaki , Shinozaki Tatsuya , Kamide Hideki , Sakai Takaaki
Published: October 2009

This paper deals with characteristics of surface vortex in a cylindrical vessel. One of the characteristics is a gas core length, which is important to estimate the onset condition of the gas entrainment but influenced easily by the experimental condition. In the experiment using water, the effects of the water temperature, water level, and the surface tension on the gas core length were investigated. The onset condition of the gas entrainment is sometimes estimated by using the Burgers vortex model but the real flow in the vessel is different from the model. The velocity fields were measured by particle image velocimetry (PIV) and the velocity gradient of the downward flow was discussed. The proper flow conditions for the Burgers vortex model are a high water level and a high flow rate.
High Temperature Interaction Between UO2 and Carbon: Application to TRISO Particles for Very High Temperature Reactors
Authors: Gossé Stéphane , Guéneau Christine , Alpettaz Thierry , Chatain Sylvie , Chatillon Christian
Published: October 2009

For very high temperature reactors, the high level operating temperature of the fuel materials in normal and accidental conditions requires studying the possible chemical interaction between the UO2 fuel kernel and the surrounding structural materials (C, SiC) that could damage the tristructural isotropic particle. The partial pressures of the gaseous carbon oxides formed at the fuel (UO2)-buffer (C) interface leading to the build up of the internal pressure in the particle have to be predicted. A good knowledge of the phase diagram and thermodynamic properties of the uranium-carbon-oxygen (UCO) system is also required to optimize the fabrication process of “UCO” kernels made of a mixture of UO2 and UC2. Thermodynamic calculations using the FUELBASE database dedicated to Generation IV fuels (Guéneau, Chatain, Gossé, Rado, Rapaud, Lechelle, Dumas, and Chatillon, 2005, “A Thermodynamic Approach for Advanced Fuels of Gas Cooled Reactors,” J. Nucl. Mater., 344, pp. 191–197) allow predicting the phase equilibria involving carbide and/or oxycarbide phases at high temperature. Very high levels of CO(g) and CO2(g) equilibrium pressures are obtained above the UO2±x fuel in equilibrium with carbon that could lead to the failure of the particle in case of high oxygen stoichiometry of the uranium dioxide. To determine the deviation from thermodynamic equilibrium, measurements of the partial pressures of CO(g) and CO2(g) resulting from the UO2/C interaction have been performed by high temperature mass spectrometry on two types of samples: (i) pellets made of a mixture of UO2 and C powders or (ii) UO2 kernels embedded in carbon powder. Kinetics of the CO(g) and CO2(g) as a function of time and temperature was determined. The measured pressures are significantly lower than the equilibrium ones predicted by thermodynamic calculations. The major gaseous product is always CO(g), which starts to be released at 1473 K. From the analysis of the partial pressure profiles as a function of time and temperature, rates of CO(g) formation have been assessed. The influence of the different geometries of the samples is shown. The factors that limit the gas release can be related to interface or diffusion processes as a function of the type of sample. The present results show the utmost importance of kinetic factors that govern the UO2/C interaction.
Ceramic Gas Turbine Development: Need for a 10Year Plan
Authors: van Roode Mark
Published: October 2009

Ceramic gas turbine development that started in the 1950s has slowed considerably since most of the large-scale ceramic gas turbine development programs of the 1970s–1990s ended. While component durability still does not meet expectations, the prospect of significant energy savings and emission reductions, potentially achievable with ceramic gas turbines, continues to justify development efforts. Four gas turbine applications have been identified that could be commercially attractive: a small recuperated gas turbine (microturbine) with ∼35% electrical efficiency, a recuperated gas turbine for transportation applications with ∼40% electrical efficiency with potential applications for efficient small engine cogeneration, a ∼40% efficient midsize industrial gas turbine, and a ∼63% (combined cycle) efficient utility turbine. Key technologies have been identified to ensure performance and component durability targets can be met over the expected life cycle for these applications. These technologies include a Si3N4 or SiC with high fracture toughness, durable EBCs for Si3N4 and SiC, an effective EBC∕TBC for SiC∕SiC, a durable oxide∕oxide ceramic matrix composite (CMC) with thermally insulating coating, and the next generation CMCs with high strength that can be used as structural materials for turbine components for small engines and for rotating components in engines of various sizes. The programs will require integrated partnerships between government, national laboratories, universities, and industry. The overall cost of the proposed development programs is estimated at U.S. $100M over 10years, i.e., an annual average of U.S. $10M.
Development of Local Heat Transfer Models for the Safety Assessment of High Temperature Gas-Cooled Reactor Cores—Part II: Prismatic Modular Reactors
Authors: Stainsby Richard , Worsley Matthew , Dawson Frances , Baker Joakim , Grief Andrew , Coddington Paul , Dennier Ana
Published: October 2009

This paper extends the work of Part I to be applicable to prismatic block fuel elements and presents a model developed for determining fuel compact and fuel block temperatures of a prismatic core modular reactor. The model is applicable both in normal operation and under fault conditions and is an extension of the multiscale modeling techniques presented in Part I. The new model has been qualified by comparison with finite element simulations for both steady-state and transient conditions. Furthermore, a model for determining the effective conductivity of the block fuel elements—important for heat removal in loss of flow conditions—is presented and, again, qualified by comparison with finite element simulations. A numerical model for predicting conduction heat transfer both within and between block fuel elements has been developed, which, when coupled with the above multiscale model, allows simulations of whole cores to be carried out, while retaining the ability to predict the temperatures of individual coolant channels and individual coated particles in the fuel if required.
Daily Electrical Silencing in the Mammalian Circadian Clock
Authors: Belle Mino D. C. , Diekman Casey O. , Forger Daniel B. , Piggins Hugh D.
Published: October 2009

Quiet Clock

Many physiological processes have circadian rhythms driven by a biological clock in the suprachiasmatic nuclei (SCN) of the brain. Within the SCN, some neurons express the molecular components of the clock and others do not. Exactly how the clock mechanism is coupled to neuronal activity is not precisely understood. Investigation of the electrophysiological properties of SCN neurons by

Belle
et al.

(p.
281
) found that, contrary to the conventionally expected rapid firing rate of the cells during the day, clock-containing cells tended not to fire, despite being in an electrically excited state. Modeling and experimental characterization of changes in channel activity revealed unexpected electrophysiological properties of the SCN cells requiring a reassessment of how the circadian clock regulates activity of SCN neurons.
Evolutionary Development of the Middle Ear in Mesozoic Therian Mammals
Authors: Ji Qiang , Luo Zhe-Xi , Zhang Xingliao , Yuan Chong-Xi , Xu Li
Published: October 2009

Ear, Ear

One defining feature of mammals, distinguishing them from other animals, is the separation of the middle ear from the jaw, which improves hearing sensitivity.

Ji
et al.

(p.
278
; see the Perspective by

Martin and Ruf

) describe an adult Mesozoic fossil mammal, in a lineage that led to both marsupials and placentals, in which the middle ear is still ossified to the jaw. Recent developmental studies have shown that the release of the ear is tied to multiple genes and signaling pathways during development. Together, these data suggest how gene patterning may have led to the early evolution of the mammalian ear.
Reconstituting Bacterial RNA Repair and Modification in Vitro
Authors: Chan Chio Mui , Zhou Chun , Huang Raven H.
Published: October 2009

A protein heterotetramer repairs RNA cleaved by ribotoxins, and methylation protects against further ribotoxin attack.
Energy Flow Under Control
Authors: Batista Victor S.
Published: October 2009

Laser pulses can be shaped to control energy transfer at the molecular scale in light-harvesting systems.
Monsoons and Meltdowns
Authors: Severinghaus Jeffrey P.
Published: October 2009

A counterintuitive connection between ice-sheet melting and weak monsoons helps to explain ice age cycles.
Sensing a Small But Persistent Current
Authors: Birge Norman O.
Published: October 2009

A magnetic field can create tiny currents that flow continuously in an ordinary metal ring, despite its electrical resistance.
Genome Project Standards in a New Era of Sequencing
Authors: Chain P. S. G. , Grafham D. V. , Fulton R. S. , FitzGerald M. G. , Hostetler J. , Muzny D. , Ali J. , Birren B. , Bruce D. C. , Buhay C. , Cole J. R. , Ding Y. , Dugan S. , Field D. , Garrity G. M. , Gibbs R. , Graves T. , Han C. S. , Harrison S. H. , Highlander S. , Hugenholtz P. , Khouri H. M. , Kodira C. D. , Kolker E. , Kyrpides N. C. , Lang D. , Lapidus A. , Malfatti S. A. , Markowitz V. , Metha T. , Nelson K. E. , Parkhill J. , Pitluck S. , Qin X. , Read T. D. , Schmutz J. , Sozhamannan S. , Sterk P. , Strausberg R. L. , Sutton G. , Thomson N. R. , Tiedje J. M. , Weinstock G. , Wollam A. ,   Genomic Standards Consortium Human Microbiome Project Jumpstart Consortium, Detter J. C.
Published: October 2009

More detailed sequence standards that keep up with revolutionary sequencing technologies will aid the research community in evaluating data.
Life After GWA Studies
Authors: Dermitzakis Emmanouil T. , Clark Andrew G.
Published: October 2009

Genome-wide association findings should be integrated into a wider scope of information, including biological processes and environments.
U.S. Researchers Recognized for Work on Telomeres
Authors: Vogel Gretchen , Pennisi Elizabeth
Published: October 2009

Three American researchers were awarded the Nobel Prize in physiology or medicine for their work describing telomeres, the repetitive DNA that caps the ends of chromosomes, and telomerase, the enzyme that makes the caps.
Looking for a Target On Every Tumor
Authors: Kaiser Jocelyn
Published: October 2009

Major cancer centers say they're getting ready to genotype every patient's tumor, hoping to match them with drugs specifically tailored to halt tumor growth.
Science Translational Medicine
Podcast: 7 October 2009
Authors: Gesty-Palmer Diane , Nabel Betsy , Lefkowitz Robert J. , Kelner Katrina L.
Published: October 2009

A conversation about translational medicine and a Research Article published in the 7 October 2009 issue of
Science Translational Medicine
.
A β-Arrestin–Biased Agonist of the Parathyroid Hormone Receptor (PTH1R) Promotes Bone Formation Independent of G Protein Activation
Authors: Gesty-Palmer Diane , Flannery Pat , Yuan Ling , Corsino Leonor , Spurney Robert , Lefkowitz Robert J. , Luttrell Louis M.
Published: October 2009

A biased agonist binds to the seven-transmembrane parathyroid hormone receptor to trigger certain downstream effects but not others, potentially avoiding undesirable side effects.
Space for the Cures:
Science
Launches a New Journal Dedicated to Translational Research in Biomedicine
Authors: Zerhouni Elias A.
Published: October 2009

Science Translational Medicine
seeks to serve as the medium for the evolving transformation of biomedical research.
Probing Broccoli's Benefits for Prostate Cancer
Authors: McDonald Heather B.
Published: October 2009

A compound in cruciferous vegetables destabilizes the androgen receptor, suggesting new possibilities for interfering with prostate cancer.
New Antibacterial Drug Destroys Dormant Bugs
Authors: LaMarco Kelly
Published: October 2009

A new class of antibiotics selectively disrupts the bacterial proteosome and kills dormant bugs.
Quadrivalent Meningococcal Vaccination of Adults: Phase III Comparison of an Investigational Conjugate Vaccine, MenACWY-CRM, with the Licensed Vaccine, Menactra
Authors: Reisinger Keith S. , Baxter Roger , Block Stanley L. , Shah Jina , Bedell Lisa , Dull Peter M.
Published: October 2009

Neisseria meningitidis
is a leading cause of bacterial meningitis in the United States, with the highest case fatality rates reported for individuals ≥15 years of age. This study compares the safety and immunogenicity of the Novartis Vaccines investigational quadrivalent meningococcal CRM
197
conjugate vaccine, MenACWY-CRM, to those of the licensed meningococcal conjugate vaccine, Menactra, when administered to healthy adults. In this phase III multicenter study, 1,359 adults 19 to 55 years of age were randomly assigned to one of four groups (1:1:1:1 ratio) to receive a single dose of one of three lots of MenACWY-CRM or a single dose of Menactra. Serum samples obtained at baseline and 1 month postvaccination were tested for serogroup-specific serum bactericidal activity using human complement (hSBA). The hSBA titers following vaccination with MenACWY-CRM and Menactra were compared in noninferiority and prespecified superiority analyses. Reactogenicity was similar in the MenACWY-CRM and Menactra groups, and neither vaccine was associated with a serious adverse event. When compared with Menactra, MenACWY-CRM met the superiority criteria for the proportions of recipients achieving a seroresponse against serogroups C, W-135, and Y and the proportion of subjects achieving postvaccination titers of ≥1:8 for serogroups C and Y. MenACWY-CRM's immunogenicity was statistically noninferior (the lower limit of the two-sided 95% confidence interval was more than −10%) to that of Menactra for all four serogroups, with the postvaccination hSBA geometric mean titers being consistently higher for MenACWY-CRM than for Menactra. MenACWY-CRM is well tolerated in adults 19 to 55 years of age, with immune responses to each of the serogroups noninferior and, in some cases, statistically superior to those to Menactra.
DNA Vaccination by Electroporation and Boosting with Recombinant Proteins Enhances the Efficacy of DNA Vaccines for Schistosomiasis Japonica
Authors: Dai Yang , Zhu Yinchang , Harn Donald A. , Wang Xiaoting , Tang Jianxia , Zhao Song , Lu Fei , Guan Xiaohong
Published: October 2009

Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China. Control programs combining chemotherapy and snail killing have not been able to block transmission of infection in lakes and marsh regions. Vaccination is needed as a complementary approach to the ongoing control programs. In the present study, we wanted to determine if the efficacies of DNA vaccines encoding the 23-kDa tetraspanin membrane protein (SjC23), triose phosphate isomerase (SjCTPI), and sixfold-repeated genes of the complementarity determining region 3 (CDR3) in the H chain of NP30 could be enhanced by boosting via electroporation in vivo and/or with cocktail protein vaccines. Mice vaccinated with cocktail DNA vaccines showed a significant worm reduction of 32.88% (P< 0.01) and egg reduction of 36.20% (P< 0.01). Vaccine efficacy was enhanced when animals were boosted with cocktail protein vaccines; adult worm and liver egg burdens were reduced 45.35% and 48.54%, respectively. Nearly identical results were obtained in mice boosted by electroporation in vivo, with adult worm and egg burdens reduced by 45.00% and 50.88%, respectively. The addition of a protein vaccine boost to this regimen further elevated efficacy to approximately 60% for adult worm burden and greater than 60% for liver egg reduction. The levels of interleukin-2, gamma interferon, and the ratios of immunoglobulin G2a (IgG2a)/IgG1 clearly showed that cocktail DNA vaccines induced CD4+Th1-type responses. Boosting via either electroporation or with recombinant proteins significantly increased associated immune responses over those seen in mice vaccinated solely with DNA vaccines. Thus, schistosome DNA vaccine efficacy was significantly enhanced via boosting by electroporation in vivo and/or cocktail protein vaccines.
Global Effects of Inactivation of the Pyruvate Kinase Gene in the
Mycobacterium tuberculosis
Complex
Authors: Chavadi Sivagamisundaram , Wooff Esen , Coldham Nicholas G. , Sritharan Manjula , Hewinson R. Glyn , Gordon Stephen V. , Wheeler Paul R.
Published: October 2009

To better understand the global effects of “natural” lesions in genes involved in the pyruvate metabolism in
Mycobacterium bovis
, null mutations were made in the
Mycobacterium tuberculosis
H37Rv
ald
and
pykA
genes to mimic the
M. bovis
situation. Like
M. bovis
, the
M. tuberculosis
Δ
pykA
mutant yielded dysgonic colonies on solid medium lacking pyruvate, whereas colony morphology was eugonic on pyruvate-containing medium. Global effects of the loss of the
pykA
gene, possibly underlying colony morphology, were investigated by using proteomics on cultures grown in the same conditions. The levels of Icd2 increased and those of Icl and PckA decreased in the Δ
pykA
knockout. Proteomics suggested that the synthesis of enzymes involved in fatty acid and lipid biosynthesis were decreased, whereas those involved in β-oxidation were increased in the
M. tuberculosis
Δ
pykA
mutant, as confirmed by direct assays for these activities. Thus, the loss of
pykA
from
M. tuberculosis
results in fatty acids being used principally for energy production, in contrast to the situation in the host when carbon from fatty acids is conserved through the glyoxylate cycle and gluconeogenesis; when an active
pykA
gene was introduced into
M. bovis
, the opposite effects occurred. Proteins involved in oxidative stress—AhpC, KatG, and SodA—showed increased synthesis in the Δ
pykA
mutant, and iron-regulated proteins were also affected. Ald levels were decreased in the Δ
pykA
knockout, explaining why an
M. tuberculosis
Δ
pykA
Δ
ald
double mutant showed little additional phenotypic effect. Overall, these data show that the loss of the
pykA
gene has powerful, global effects on proteins associated with central metabolism.
Comparison of Two Chromogenic Media for Selective Isolation of Vancomycin-Resistant Enterococci from Stool Specimens
Authors: Peltroche-Llacsahuanga Heidrun , Top Janetta , Weber-Heynemann Josefine , Lütticken Rudolf , Haase Gerhard
Published: October 2009

Two chromogenic media (Chromagar VRE and chromID VRE [C-ID]) performed equally well in the direct detection of vancomycin-resistant enterococci (VRE) in stool specimens after an overnight enrichment step and a 48-h incubation period, with a sensitivity of 98.2% (56/57) for both and specificities of 96.5% (195/202) and 97.5% (197/202), respectively. However, assigning discriminatory colony color was sometimes difficult, especially on C-ID. In order to facilitate simple species identification, biochemical key reactions were implemented.
Nonrandom Distribution of
Pseudomonas aeruginosa
and
Staphylococcus aureus
in Chronic Wounds
Authors: Fazli Mustafa , Bjarnsholt Thomas , Kirketerp-Møller Klaus , Jørgensen Bo , Andersen Anders Schou , Krogfelt Karen A. , Givskov Michael , Tolker-Nielsen Tim
Published: October 2009

The spatial organization of
Pseudomonas aeruginosa
and
Staphylococcus aureus
in chronic wounds was investigated in the present study. Wound biopsy specimens were obtained from patients diagnosed as having chronic venous leg ulcers, and bacterial aggregates in these wounds were detected and located by the use of peptide nucleic acid-based fluorescence in situ hybridization and confocal laser scanning microscopy (CLSM). We acquired CLSM images of multiple regions in multiple sections cut from five wounds containing
P. aeruginosa
and five wounds containing
S. aureus
and measured the distance of the bacterial aggregates to the wound surface. The distance of the
P. aeruginosa
aggregates to the wound surface was significantly greater than that of the
S. aureus
aggregates, suggesting that the distribution of the bacteria in the chronic wounds was nonrandom. The results are discussed in relation to our recent finding that swab culturing techniques may underestimate the presence of
P. aeruginosa
in chronic wounds and in relation to the hypothesis that
P. aeruginosa
bacteria located in the deeper regions of chronic wounds may play an important role in keeping the wounds arrested in a stage dominated by inflammatory processes.
Evaluation of Hepatitis C Virus Core Antigen Assays in Detecting Recombinant Viral Antigens of Various Genotypes
Authors: Saeed Mohsan , Suzuki Ryosuke , Kondo Madoka , Aizaki Hideki , Kato Takanobu , Mizuochi Toshiaki , Wakita Takaji , Watanabe Haruo , Suzuki Tetsuro
Published: October 2009

A single substitution within the hepatitis C virus core antigen sequence, A48T, which is observed in ∼30% of individuals infected with genotype 2a virus, reduces the sensitivity of a commonly used chemiluminescence enzyme immunoassay. Quantitation of the antigen is improved by using a distinct anticore antibody with a different epitope.
Physical Requirements and Functional Consequences of Complex Formation between the Cytomegalovirus IE1 Protein and Human STAT2
Authors: Krauss Steffen , Kaps Julia , Czech Nathalie , Paulus Christina , Nevels Michael
Published: October 2009

Our previous work has shown that efficient evasion from type I interferon responses by human cytomegalovirus (hCMV) requires expression of the 72-kDa immediate-early 1 (IE1) protein. It has been suggested that IE1 inhibits interferon signaling through intranuclear sequestration of the signal transducer and activator of transcription 2 (STAT2) protein. Here we show that physical association and subnuclear colocalization of IE1 and STAT2 depend on short acidic and serine/proline-rich low-complexity motifs in the carboxy-terminal region of the 491-amino-acid viral polypeptide. These motifs compose an essential core (amino acids 373 to 420) and an adjacent ancillary site (amino acids 421 to 445) for STAT2 interaction that are predicted to form part of a natively unstructured domain. The presence of presumably “disordered” carboxy-terminal domains enriched in low-complexity motifs is evolutionarily highly conserved across all examined mammalian IE1 orthologs, and the murine cytomegalovirus IE1 protein appears to interact with STAT2 just like the human counterpart. A recombinant hCMV specifically mutated in the IE1 core STAT2 binding site displays hypersensitivity to alpha interferon, delayed early viral protein accumulation, and attenuated growth in fibroblasts. However, replication of this mutant virus is specifically restored by knockdown of STAT2 expression. Interestingly, complex formation with STAT2 proved to be entirely separable from disruption of nuclear domain 10 (ND10), another key activity of IE1. Finally, our results demonstrate that IE1 counteracts the antiviral interferon response and promotes viral replication by at least two distinct mechanisms, one depending on sequestration of STAT2 and the other one likely involving ND10 interaction.
Determinants of the Hepatitis C Virus Nonstructural Protein 2 Protease Domain Required for Production of Infectious Virus
Authors: Dentzer Thomas G. , Lorenz Ivo C. , Evans Matthew J. , Rice Charles M.
Published: October 2009

The hepatitis C virus (HCV) nonstructural protein 2 (NS2) is a dimeric multifunctional hydrophobic protein with an essential but poorly understood role in infectious virus production. We investigated the determinants of NS2 function in the HCV life cycle. On the basis of the crystal structure of the postcleavage form of the NS2 protease domain, we mutated conserved features and analyzed the effects of these changes on polyprotein processing, replication, and infectious virus production. We found that mutations around the protease active site inhibit viral RNA replication, likely by preventing NS2-3 cleavage. In contrast, alterations at the dimer interface or in the C-terminal region did not affect replication, NS2 stability, or NS2 protease activity but decreased infectious virus production. A comprehensive deletion and mutagenesis analysis of the C-terminal end of NS2 revealed the importance of its C-terminal leucine residue in infectious particle production. The crystal structure of the NS2 protease domain shows that this C-terminal leucine is locked in the active site, and mutation or deletion of this residue could therefore alter the conformation of NS2 and disrupt potential protein-protein interactions important for infectious particle production. These studies begin to dissect the residues of NS2 involved in its multiple essential roles in the HCV life cycle and suggest NS2 as a viable target for HCV-specific inhibitors.
Downregulation of the T-Cell Receptor by Human Immunodeficiency Virus Type 2 Nef Does Not Protect against Disease Progression
Authors: Feldmann Jérôme , Leligdowicz Aleksandra , Jaye Assan , Dong Tao , Whittle Hilton , Rowland-Jones Sarah L.
Published: October 2009

Chronic immune activation is thought to play a major role in human immunodeficiency virus (HIV) pathogenesis, but the relative contributions of multiple factors to immune activation are not known. One proposed mechanism to protect against immune activation is the ability of Nef proteins from some HIV and simian immunodeficiency virus strains to downregulate the T-cell receptor (TCR)-CD3 complex of the infected cell, thereby reducing the potential for deleterious activation. HIV type 1 (HIV-1) Nef has lost this property. In contrast to HIV-1, HIV-2 infection is characterized by a marked disparity in the disease course, with most individuals maintaining a normal life span. In this study, we examined the relationship between the ability of HIV-2 Nef proteins to downregulate the TCR and immune activation, comparing progressors and nonprogressors. Representative Nef variants were isolated from 28 HIV-2-infected individuals. We assessed their abilities to downregulate the TCR from the surfaces of CD4 T cells. In the same individuals, the activation of peripheral lymphocytes was evaluated by measurement of the expression levels of HLA-DR and CD38. We observed a striking correlation of the TCR downregulation efficiency of HIV-2 Nef variants with immune activation in individuals with a low viral load. This strongly suggests that Nef expression can influence the activation state of the immune systems of infected individuals. However, the efficiency of TCR downregulation by Nef was not reduced in progressing individuals, showing that TCR downregulation does not protect against progression in HIV-2 infection.
Molecular Characterization of a Novel Gammaretrovirus in Killer Whales (
Orcinus orca
)
Authors: LaMere Sarah A. , St. Leger Judy A. , Schrenzel Mark D. , Anthony Simon J. , Rideout Bruce A. , Salomon Daniel R.
Published: October 2009

There are currently no published data documenting the presence of retroviruses in cetaceans, though the occurrences of cancers and immunodeficiency states suggest the potential. We examined tissues from adult killer whales and detected a novel gammaretrovirus by degenerate PCR. Reverse transcription-PCR also demonstrated tissue and serum expression of retroviral mRNA. The full-length sequence of the provirus was obtained by PCR, and a TaqMan-based copy number assay did not demonstrate evidence of productive infection. PCR on blood samples from 11 healthy captive killer whales and tissues from 3 free-ranging animals detected the proviral DNA in all tissues examined from all animals. A survey of multiple cetacean species by PCR for
gag
,
pol
, and
env
sequences showed homologs of this virus in the DNA of eight species of delphinids, pygmy and dwarf sperm whales, and harbor porpoises, but not in beluga or fin whales. Analysis of the bottlenose dolphin genome revealed two full-length proviral sequences with 97.4% and 96.9% nucleotide identity to the killer whale gammaretrovirus. The results of single-cell PCR on killer whale sperm and Southern blotting are also consistent with the conclusion that the provirus is endogenous. We suggest that this gammaretrovirus entered the delphinoid ancestor's genome before the divergence of modern dolphins or that an exogenous variant existed following divergence that was ultimately endogenized. However, the transcriptional activity demonstrated in tissues and the nearly intact viral genome suggest a more recent integration into the killer whale genome, favoring the latter hypothesis. The proposed name for this retrovirus is killer whale endogenous retrovirus.
Reconstitution of the Ancestral Glycoprotein of Human Endogenous Retrovirus K and Modulation of Its Functional Activity by Truncation of the Cytoplasmic Domain
Authors: Hanke Kirsten , Kramer Philipp , Seeher Sandra , Beimforde Nadine , Kurth Reinhard , Bannert Norbert
Published: October 2009

Endogenous retroviruses present in the human genome provide a rich record of ancient infections. All presently recognized elements, including the youngest and most intact proviruses of the human endogenous retrovirus K(HML-2) [HERV-K(HML-2)] family, have suffered postinsertional mutations during their time of chromosomal residence, and genes encoding the envelope glycoprotein (Env) have not been spared these mutations. In this study, we have, for the first time, reconstituted an authentic Env of a HERV-K(HML-2) provirus by back mutation of putative postinsertional amino acid changes of the protein encoded by HERV-K113. Aided by codon-optimized expression, we demonstrate that the reconstituted Env regained its ability to be incorporated into retroviral particles and to mediate entry. The original ancient HERV-K113 Env was synthesized as a moderately glycosylated gp95 precursor protein cleaved into surface and transmembrane (TM) subunits. Of the nine N-linked oligosaccharides, four are part of the TM subunit, contributing 15 kDa to its apparent molecular mass of 41 kDa. The carbohydrates, as well as the cytoplasmic tail, are critical for efficient intracellular trafficking, processing, stability, and particle incorporation. Whereas deletions of the carboxy-terminal 6 residues completely abrogated cleavage and virion association, more extensive truncations slightly enhanced incorporation but dramatically increased the ability to mediate entry of pseudotyped lentiviruses. Although the first HERV-K(HML-2) elements infected human ancestors about 30 million years ago, our findings indicate that their glycoproteins are in most respects remarkably similar to those of classical contemporary retroviruses and can still mediate efficient entry into mammalian cells.
Effects of Acute and Chronic Murine Norovirus Infections on Immune Responses and Recovery from Friend Retrovirus Infection
Authors: Ammann Christoph G. , Messer Ronald J. , Varvel Kimberly , DeBuysscher Blair L. , LaCasse Rachel A. , Pinto Amelia K. , Hasenkrug Kim J.
Published: October 2009

Murine norovirus (MNV) is a highly infectious but generally nonpathogenic agent that is commonly found in research mouse colonies in both North America and Europe. In the present study, the effects of acute and chronic infections with MNV on immune responses and recovery from concurrent Friend virus (FV) infections were investigated. No significant differences in T-cell or NK-cell responses, FV-neutralizing antibody responses, or long-term recovery from FV infection were observed. We conclude that concurrent MNV infections had no major impacts on FV infections.
Importance of Covalent and Noncovalent SUMO Interactions with the Major Human Cytomegalovirus Transactivator IE2p86 for Viral Infection
Authors: Berndt Anja , Hofmann-Winkler Heike , Tavalai Nina , Hahn Gabriele , Stamminger Thomas
Published: October 2009

The major transactivator protein IE2p86 of human cytomegalovirus (HCMV) has previously been shown to undergo posttranslational modification by the covalent attachment of SUMO proteins, termed SUMOylation, which occurs at two lysine residues located at amino acid positions 175 and 180. Mutation of the acceptor lysines resulted in the abrogation of IE2p86 SUMOylation in mammalian cells and a strong reduction of IE2p86-mediated transactivation. In this paper, we identify an additional SUMO interaction motif (SIM) within IE2p86, which mediates noncovalent binding to SUMO, as shown by yeast two-hybrid analyses. Transient-expression experiments revealed that an IE2p86 SIM mutant exhibited significantly reduced SUMOylation, strongly suggesting that noncovalent SUMO interactions affect the efficacy of covalent SUMO coupling. In order to define the relevance of IE2p86 SUMO interactions for viral replication, recombinant viruses originating from two different HCMV strains (AD169 and VR1814) were generated. Analysis of viruses expressing SUMOylation-negative IE2p86 revealed strongly impaired replication due to reduced viral DNA and protein accumulation, as well as diminished initiation of immediate-early gene expression. The additional introduction of the SIM mutation into the viral genome did not further compromise viral replication but resulted in altered expression of viral proteins at late times postinfection. In summary, this paper clearly shows that IE2p86 SUMOylation is necessary for efficient replication of the HCMV laboratory strain AD169 and the clinical isolate VR1814 and thus for the in vivo function of this viral transcription factor.
Insights into the Evolutionary History of an Emerging Livestock Pathogen: Porcine Circovirus 2
Authors: Firth Cadhla , Charleston Michael A. , Duffy Siobain , Shapiro Beth , Holmes Edward C.
Published: October 2009

Porcine circovirus 2 (PCV2) is the primary etiological agent of postweaning multisystemic wasting syndrome (PMWS), one of the most economically important emerging swine diseases worldwide. Virulent PCV2 was first identified following nearly simultaneous outbreaks of PMWS in North America and Europe in the 1990s and has since achieved global distribution. However, the processes responsible for the emergence and spread of PCV2 remain poorly understood. Here, phylogenetic and cophylogenetic inferences were utilized to address key questions on the time scale, processes, and geographic diffusion of emerging PCV2. The results of these analyses suggest that the two genotypes of PCV2 (PCV2a and PCV2b) are likely to have emerged from a common ancestor approximately 100 years ago and have been on independent evolutionary trajectories since that time, despite cocirculating in the same host species and geographic regions. The patterns of geographic movement of PCV2 that we recovered appear to mimic those of the global pig trade and suggest that the movement of asymptomatic animals is likely to have facilitated the rapid spread of virulent PCV2 around the globe. We further estimated the rate of nucleotide substitution for PCV2 to be on the order of 1.2 × 10
−3
substitutions/site/year, the highest yet recorded for a single-stranded DNA virus. This high rate of evolution may allow PCV2 to maintain evolutionary dynamics closer to those of single-stranded RNA viruses than to those of double-stranded DNA viruses, further facilitating the rapid emergence of PCV2 worldwide.
Predatory Feeding Behavior of Epischura lacustris (Copepoda, Calanoida) and Prey Defense
Authors: Wong C. Kim
Published: October 2009

The predatory feeding behavior of Epischura lacustris on Bosmina longirostris and Ceriodaphnia reticulata was investigated. Epischura rarely killed Bosmina > 0.40 mm in length, but below this threshold there was no size selection because predation rates were affected mainly by encounter rate and ingestion probability. When presented with Bosmina and Ceriodaphnia, Epischura fed at higher rates on Bosmina which were more easily captured. Epischura showed no true behavioral preference or switching, and its diet included all the prey it could detect, capture, and ingest successfully. Previous diet had no effect on prey selection. Predation rates on Bosmina were not affected by the presence of algal food.Key words: predatory copepod, predator–prey interactions, size selection, switching, prey defense