bluuebunny/crossref_metadata_2025 huggingface dataset:
FUNCTIONAL ANALYSIS OF A MOSQUITO SHORT‐CHAIN DEHYDROGENASE CLUSTER
Authors: Mayoral Jaime G. , Leonard Kate T. , Nouzova Marcela , Noriega Fernando G. , Defelipe Lucas A. , Turjanski Adrian G.
Published: December 2012

The short‐chain dehydrogenases (SDR) constitute one of the oldest and largest families of enzymes with over 46,000 members in sequence databases. About 25% of all known dehydrogenases belong to the SDR family. SDR enzymes have critical roles in lipid, amino acid, carbohydrate, hormone, and xenobiotic metabolism as well as in redox sensor mechanisms. This family is present in archaea, bacteria, and eukaryota, emphasizing their versatility and fundamental importance for metabolic processes. We identified a cluster of eight SDRs in the mosquito Aedes aegypti (AaSDRs). Members of the cluster differ in tissue specificity and developmental expression. Heterologous expression produced recombinant proteins that had diverse substrate specificities, but distinct from the conventional insect alcohol (ethanol) dehydrogenases. They are all NADP+‐dependent and they have S‐enantioselectivity and preference for secondary alcohols with 8–15 carbons. Homology modeling was used to build the structure of AaSDR1 and two additional cluster members. The computational study helped explain the selectivity toward the (10S)‐isomers as well as the reduced activity of AaSDR4 and AaSDR9 for longer isoprenoid substrates. Similar clusters of SDRs are present in other species of insects, suggesting similar selection mechanisms causing duplication and diversification of this family of enzymes.
Association of brain functional magnetic resonance activity with response to tumor necrosis factor inhibition in rheumatoid arthritis
Authors: Rech Juergen , Hess Andreas , Finzel Stephanie , Kreitz Silke , Sergeeva Marina , Englbrecht Matthias , Doerfler Arnd , Saake Marc , Schett Georg
Published: December 2012

Objective

To test whether brain activity predicts the response to tumor necrosis factor inhibitors (TNFi) in patients with rheumatoid arthritis (RA). Since clinical and laboratory parameters have proven unsuccessful in predicting response, we followed a radically different concept, hypothesizing that response to TNFi depends on central nervous system activity rather than the clinical signs of disease.

Methods

Sequential testing by functional magnetic resonance imaging (MRI) of the brain, anatomic MRI of the hand, and clinical assessment of arthritis were carried out in 10 patients with active RA before and 3, 7, and 28 days after the start of TNFi treatment.

Results

Baseline demographic and disease‐specific parameters were identical in TNFi responders and nonresponders. The mean ± SEM decrease in the Disease Activity Score in 28 joints after 28 days was −1.8 ± 0.3 in TNFi responders (n = 5) and −0.2 ± 0.1 in nonresponders (n = 5). Responders showed significantly higher baseline activation in thalamic, limbic, and associative areas of the brain than nonresponders. Moreover, brain activity decreased within 3 days after TNFi exposure in the responders, preceding clinical responses (day 7) and responses observed on the anatomic hand MRI (day 28).

Conclusion

These data suggest that response to TNFi depends on brain activity in RA patients, reflecting the subjective perception of disease.
Type II collagen–specific antibodies induce cartilage damage in mice independent of inflammation
Authors: Croxford Allyson M. , Whittingham Senga , McNaughton Donald , Nandakumar Kutty Selva , Holmdahl Rikard , Rowley Merrill J.
Published: December 2012

Objective

Murine collagen antibody–induced arthritis (CAIA), like collagen‐induced arthritis, has clinical and immunopathologic features that parallel those in human rheumatoid arthritis (RA). This study was undertaken to examine the effects of autoantibodies to type II collagen (CII) on articular cartilage in the paws of mice, under conditions in which other factors that may influence joint pathology could be excluded.

Methods

Mice of 2 different strains, B10.QC5δ and the parental strain B10.Q, were injected intravenously with either saline or arthritogenic monoclonal antibodies (mAb) to CII. B10.QC5δ mice lack complement factor C5 and do not develop CAIA when injected with arthritogenic mAb, whereas B10.Q mice have C5 and develop CAIA when administered the mAb and a subsequent injection of lipopolysaccharide. Three days after injection the paws of the mice were examined by standard histologic methods to assess morphologic appearance and proteoglycan loss, and by synchrotron‐enhanced Fourier transform infrared microspectroscopy to assess chemical evidence of structural change.

Results

No macroscopic or microscopic signs of inflammation were evident in the mice. However, in contrast to the saline‐injected controls, all mAb‐injected mice exhibited cartilage damage in all joints, with loss of proteoglycans and collagen, chondrocyte hyperplasia and/or loss, and surface damage in the interphalangeal joints.

Conclusion

The implication of these findings is that an autoimmune response to CII can disrupt articular cartilage, particularly that of the small joints, and the subsequent integrity of the cartilage depends on a balance between breakdown and repair. This has relevance with regard to RA, in which such autoantibodies occur but the inflammatory response may dominate clinically and mask underlying features of the autoimmune response.
Sex, blogs, and baring your soul: Factors influencing UK blogging strategies
Authors: Fullwood Chris , Melrose Karen , Morris Neil , Floyd Sarah
Published: December 2012

There is an abundance of evidence to suggest that online behavior differs from behaviors in the offline world, and that there are a number of important factors which may affect the communication strategies of people within an online space. This article examines some of these, namely, whether the sex, age, and identifiability of blog authors, as well as the genre of communication, affect communication strategies. Findings suggest that the level of identifiability of the blog author has a limited effect upon their communication strategies. However, sex appeared to influence online behavior in so far as men were more likely to swear and attack others in their blogs. Genre had an important influence on disclosure with more self‐disclosure taking place in the diary genre (i.e., blogs in which people talk about their own lives) comparative to the filter genre (i.e., blogs in which people talk about events external to their lives). Age affected both self‐disclosure and language use. For example, younger bloggers tended to use more swearing, express more negative emotions and disclose more personal information about others. These findings suggest that age, sex, genre, and identifiability form a cluster of variables that influence the language style and self‐disclosure patterns of bloggers; however, the level of identifiability of the blogger may be less important in this respect. Implications of these findings are discussed.
Modeling the relationship between an emerging infectious disease epidemic and the body of scientific literature associated with it: The case of HIV/AIDS in the United States
Authors: Naidoo Jeff , Huber Jeffrey T. , Cupp Pamela , Wu Qishan
Published: December 2012

This study undertook an exploratory analysis of the relationship between the body of scientific literature associated with HIV/AIDS and the trajectory of the epidemic, measured by the rate of new cases diagnosed annually in the United States for the period covering 1981 to 2009. The body of scientific literature examined in this investigation was constituted from scientific research that developed alongside the epidemic and was extracted from MEDLINE, a bibliographic database of the United States. National Library of Medicine. Content analysis methods were employed for qualitative data reduction, and regression analysis was used to assess whether variation in the trajectory of the epidemic co‐occurred with variation in the publication of specific genres of content within the scientific literature relating to HIV/AIDS. The regression model confirmed a statistically significant association between the representative body of HIV/AIDS scientific literature and the epidemic trajectory, and identified three research categories, namely, ameliorative drug treatments, other clinical protocols, and health education, as being most significantly associated with the epidemic trajectory. Implicit in the findings of this study are areas of scientific research that are of functional and practical interest to clinicians, policy makers, the lay public, and contributors to the body of scientific literature.
Application of the task‐technology fit model to structure and evaluate the adoption of E‐books by Academics
Authors: D'Ambra John , Wilson Concepción S. , Akter Shahriar
Published: December 2012

Increasingly, e‐books are becoming alternatives to print books in academic libraries, thus providing opportunities to assess how well the use of e‐books meets the requirements of academics. This study uses the task‐technology fit (TTF) model to explore the interrelationships of e‐books, the affordances offered by smart readers, the information needs of academics, and the “fit” of technology to tasks as well as performance. We propose that the adoption of e‐books will be dependent on how academics perceive the fit of this new medium to the tasks they undertake as well as what added‐value functionality is delivered by the information technology that delivers the content. The study used content analysis and an online survey, administered to the faculty in Medicine, Science and Engineering at the University of New South Wales, to identify the attributes of a TTF construct of e‐books in academic settings. Using exploratory factor analysis, preliminary findings confirmed annotation, navigation, and output as the core dimensions of the TTF construct. The results of confirmatory factor analysis using partial least squares path modeling supported the overall TTF model in reflecting significant positive impact of task, technology, and individual characteristics on TTF for e‐books in academic settings; it also confirmed significant positive impact of TTF on individuals' performance and use, and impact of using e‐books on individual performance. Our research makes two contributions: the development of an e‐book TTF construct and the testing of that construct in a model validating the efficacy of the TTF framework in measuring perceived fit of e‐books to academic tasks.
Bias in peer review
Authors: Lee Carole J. , Sugimoto Cassidy R. , Zhang Guo , Cronin Blaise
Published: December 2012

Research on bias in peer review examines scholarly communication and funding processes to assess the epistemic and social legitimacy of the mechanisms by which knowledge communities vet and self‐regulate their work. Despite vocal concerns, a closer look at the empirical and methodological limitations of research on bias raises questions about the existence and extent of many hypothesized forms of bias. In addition, the notion of bias is predicated on an implicit ideal that, once articulated, raises questions about the normative implications of research on bias in peer review. This review provides a brief description of the function, history, and scope of peer review; articulates and critiques the conception of bias unifying research on bias in peer review; characterizes and examines the empirical, methodological, and normative claims of bias in peer review research; and assesses possible alternatives to the status quo. We close by identifying ways to expand conceptions and studies of bias to contend with the complexity of social interactions among actors involved directly and indirectly in peer review.
Volume 1 of the BJS
Authors: Ellis H
Published: December 2012

Good start
On the Controversial Fitting of Susceptibility Curves of Ferromagnetic CuII Cubanes: Insights from Theoretical Calculations
Authors: Calzado Carmen J.
Published: December 2012

This paper reports a theoretical analysis of the electronic structure and magnetic properties of a tetranuclear CuII complex, [Cu4(HL)4], which has a 4+2 cubane‐like structure (H3L=N,N′‐(2‐hydroxypropane‐1,3‐diyl)bis(acetylacetoneimine)). These theoretical calculations indicate a quintet (S=2) ground state; the energy‐level distribution of the magnetic states confirm Heisenberg behaviour and correspond to an S4 spin–spin interaction model. The dominant interaction is the ferromagnetic coupling between the pseudo‐dimeric units (J1=22.2 cm−1), whilst a weak and ferromagnetic interaction is found within the pseudo‐dimeric units (J2=1.4 cm−1). The amplitude and sign of these interactions are consistent with the structure and arrangement of the magnetic Cu 3d orbitals; they accurately simulate the thermal dependence of magnetic susceptibility, but do not agree with the reported J values (J1=38.4 cm−1, J2=−18.0 cm−1) that result from the experimental fitting. This result is not an isolated case; many other polynuclear systems, in particular 4+2 CuII cubanes, have been reported in which the fitted magnetic terms are not consistent with the geometrical features of the system. In this context, theoretical evaluation can be considered as a valuable tool in the interpretation of the macroscopic behaviour, thus providing clues for a rational and directed design of new materials with specific properties.
Production of Polyunsaturated Fatty Acids by Mortierella alpina Using Submerse and Solid State Fermentation
Authors: Stressler Timo , Eisele Thomas , Rost Johanna , Haunschild Eva‐Maria , Kuhn Andreas , Fischer Lutz
Published: December 2012

A new isolate of Mortierella alpina, > 98 % identical with M. alpina ATCC 16266, was cultivated in a defined glucose‐based medium with three organic nitrogen sources (glycine, urea and Na‐L‐glutamate) at three different concentrations in shaking flasks at 20 °C. The results were compared to the cultivation in complex medium with yeast extract as nitrogen source. In the defined media, high yields of polyunsaturated fatty acids (PUFAs) and arachidonic acid (ARA), respectively, were obtained with Na‐L‐glutamate. However, the absolute highest yields of PUFA and ARA were measured with the yeast extract medium. An optimized yeast extract complex medium was used for a submerse bioreactor cultivation in a 45‐L scale. Furthermore, M. alpina was cultivated in a solid state fermenter, using an oat bran water mixture as substrate.
Photocatalytic Degradation of 17α‐Ethinylestradiol and Inactivation of Escherichia coli Using Ag‐Modified TiO2 Nanotube Arrays
Authors: Mao Kai , Li Yi , Zhang Houhu , Zhang Wenlong , Yan Wenming
Published: December 2012

Ag‐modified TiO2 nanotube arrays (Ag/TiO2 NAs) were prepared and employed as a photocatalyst for degradation of 17α‐ethinylestradiol (EE2) and inactivation of Escherichia coli. The as‐synthesized Ag/TiO2 NAs were characterized by field‐emission scanning electron microscope (FESEM), X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). It was found that metallic Ag nanoparticles were firmly deposited on the TiO2 NAs with the pore diameter of 100 nm and the length of 550 nm. Photocatalytic degradation of EE2 and inactivation of E. coli were enhanced effectively in an analogical trend using Ag/TiO2 NAs. In particular, Ag/TiO2 NAs exhibited the antimicrobial activity even in the absence of light. The Ag acted as a disinfection agent as well as the dopant of the modified TiO2 NAs photocatalysis by forming a Schottky barrier on the surface of TiO2 NAs. Inorganic ions suppressed the rates of photocatalytic degradation of EE2, with HCO having a more pronounced effect than NO or SO. Humic acid (HA) was found to increase the rate of EE2 degradation.
Analyzing Effects of Shrub Canopy on Throughfall and Phreatic Water Using Water Isotopes, Western China
Authors: Liu Yuhong , Xu Zhen , Liu Fude , Wang Lixin , An Shuqing , Liu Shirong
Published: December 2012

Alpine shrub Quercus aquifolioides was selected to study the effects of shrub canopy on throughfall and phreatic water by analyzing the isotopic time series of precipitation, canopy throughfall and phreatic water and examining correlations among these series in Wolong Nature Reserve, Western China. Based on analysis of precipitation data in 2003, the local meteoric water line during the rainy season was δD = 8.28 × δ18O + 8.93, and the primary precipitation moisture in this region originated from the Pacific Ocean in the summer. Stable isotope analysis showed that the main supply of throughfall and phreatic water was from precipitation, and the shrub canopy has an important effect on the processes of rainwater transmuted into throughfall and phreatic water. Moreover, the differences of δD and δ18O values between rainwater and throughfall were relevant to rainfall. Due to interception of the shrub canopy, there had a response hysteresis of phreatic water to the various rainfall events, which was mostly 2 days, except that this hysteresis was ≤1 day when rainfall was >15 mm/day.
Non‐natural Peptide Triazole Antagonists of HIV‐1 Envelope gp120
Authors: Kamanna Kantharaju , Aneja Rachna , Duffy Caitlin , Kubinski Pamela , Rodrigo Moreira Diogo , Bailey Lauren D. , McFadden Karyn , Schön Arne , Holmes Andrew , Tuzer Ferit , Contarino Mark , Freire Ernesto , Chaiken Irwin M.
Published: December 2012

We investigated the derivation of non‐natural peptide triazole dual receptor site antagonists of HIV‐1 Env gp120 to establish a pathway for developing peptidomimetic antiviral agents. Previously we found that the peptide triazole HNG‐156 [R‐I‐N‐N‐I‐X‐W‐S‐E‐A‐M‐M‐CONH2, in which X=ferrocenyltriazole‐Pro (FtP)] has nanomolar binding affinity to gp120, inhibits gp120 binding to CD4 and the co‐receptor surrogate mAb 17b, and has potent antiviral activity in cell infection assays. Furthermore, truncated variants of HNG‐156, typified by UM‐24 (Cit‐N‐N‐I‐X‐W‐S‐CONH2) and containing the critical central stereospecific LX‐LW cluster, retain the functional characteristics of the parent peptide triazole. In the current work, we examined the possibility of replacing natural with unnatural residue components in UM‐24 to the greatest extent possible. The analogue with the critical “hot spot” residue Trp 6 replaced with L‐3‐benzothienylalanine (Bta) (KR‐41), as well as a completely non‐natural analogue containing D‐amino acid substitutions outside the central cluster (KR‐42, DCit‐DN‐DN‐DI‐X‐Bta‐DS‐CONH2), retained the dual receptor site antagonism/antiviral activity signature. The results define differential functional roles of subdomains within the peptide triazole and provide a structural basis for the design of metabolically stable peptidomimetic inhibitors of HIV‐1 Env gp120.
Neocortical arealization: Evolution, mechanisms, and open questions
Authors: Alfano Christian , Studer Michèle
Published: December 2012

The mammalian neocortex is a structure with no equals in the vertebrates and is the seat of the highest cerebral functions, such as thoughts and consciousness. It is radially organized into six layers and tangentially subdivided into functional areas deputed to the elaboration of sensory information, association between different stimuli, and selection and triggering of voluntary movements. The process subdividing the neocortical field into several functional areas is called “arealization”. Each area has its own cytoarchitecture, connectivity, and peculiar functions. In the last century, several neuroscientists have investigated areal structure and the mechanisms that have led during evolution to the rising of the neocortex and its organization. The extreme conservation in the positioning and wiring of neocortical areas among different mammalian families suggests a conserved genetic program orchestrating neocortical patterning. However, the impressive plasticity of the neocortex, which is able to rewire and reorganize areal structures and connectivity after impairments of sensory pathways, argues for a more complex scenario. Indeed, even if genetics and molecular biology helped in identifying several genes involved in the arealization process, the logic underlying the neocortical bauplan is still beyond our comprehension. In this review, we will introduce the present knowledge and hypotheses on the ontogenesis and evolution of neocortical areas. Then, we will focus our attention on some open issues, which are still unresolved, and discuss some recent studies that might open new directions to be explored in the next few years. © 2012 Wiley Periodicals, Inc. Develop Neurobiol 73: 411–447, 2013.
The effects of season on fat and fatty acids contents of shrimp and prawn species
Authors: Ayas Deniz , Ozogul Yesim , Yazgan Hatice
Published: December 2012

The effects of seasons on the lipid content and fatty acid compositions of five different shrimp and prawn species (green tiger prawn – Penaeus semisulcatus, kuruma prawn – Marsupenaeus japonicus, caramote prawn – Melicertus kerathurus, deepwater pink shrimp – Parapenaeus longirostris, speckled shrimp – Metapenaeus monoceros) were evaluated. Results showed that lipid content ranged from 0.89 to 1.55% in muscle, showing that all species were considered as lean. There were significant differences (p<0.05) in the levels of saturated fatty acids (SFA), monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) in terms of season and species. They were rich in n‐3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The highest proportions of EPA were obtained from kuruma prawn (180.9 mg/100 g) in spring and deepwater pink shrimp (173.2 mg/100 g) and caramote prawn (146.3 mg/100 g) in summer. Kuruma prawn had the highest DHA in spring (140.8 mg/100 g) followed by deepwater pink shrimp (132.2 mg/100 g) and caramote prawn (129.6 mg/100 g) in summer. The results also showed that the seasons affected lipid content and the fatty acid composition of shrimp and prawn species.

Practical Application: The beneficial effect of seafood consumption on human health has been related to the high content of n‐3 fatty acids, especially EPA (20:5n‐3) and DHA (22:6n‐3). The ratios of n‐6/n‐3, PUFA/SFA and EPA + DHA are considered as useful criteria for comparing relative nutritional and oxidation values of marine oils. In the current study, the influence of seasonality on the lipid content and the fatty acid compositions of shrimp and prawn were investigated in order to find the best source of n‐3 fatty acids during the year.
Particle filtering for Gumbel‐distributed daily maxima of methane and nitrous oxide
Authors: Toulemonde Gwladys , Guillou Armelle , Naveau Philippe
Published: December 2012

In atmospheric chemistry, daily maxima concentrations capture information about the variability among peak values. Statistically, they can often be modeled by a Gumbel distribution. This is the case for two very important greenhouse gases methane and nitrous oxide maxima when they are measured at our site of interest, Gif‐sur‐Yvette, a city south west of Paris. In practice, those two daily concentrations are not always recorded during the same period, and it would be of interest to reconstruct one from the other one. Such a type of inference can be handled within a state space modeling framework, but state space models are not tailored to represent the dynamics among Gumbel‐distributed maxima. By building on our previous work, which made a link between linear autoregressive time series and Gumbel‐distributed maxima, we propose and study such a state space model. It has the advantages of being linear and of preserving the Gumbel characteristic in both the state and observational equations. Concerning the inference of the hidden maxima at the state equation level, we derive the optimal weights of the auxiliary particle filtering approach of Pitt and Shephard. A simulation study indicates that our approach offers a gain over the Kalman filter, the bootstrap filter, and the nonmodified version of the Pitt and Shephard auxiliary filter. Copyright © 2012 John Wiley & Sons, Ltd.
Temporal variations of reservoir sediment sources in a small mountainous catchment in Korea
Authors: Kim Jin Kwan , Onda Yuichi , Yang Dong‐Yoon , Kim Min Seok
Published: December 2012

An understanding of the temporal variation in reservoir sedimentation and identification of the main sources of sediment are necessary for the maintenance of sustainable reservoirs. For this purpose, field measurements, sampling, and fingerprinting of reservoir sediment were undertaken from July 2005 to November 2007. Source fingerprinting of reservoir sediment was conducted using cesium‐137 (137Cs). The relative contributions of gully bank and forest road, and forest floor material to reservoir sediment were calculated using a mixing model. Bank and forest road material, estimated to make up about 96% of the reservoir sediment, was the dominant source. Enormous reservoir sedimentation, which amounted to about 60% of the total reservoir sedimentation during the observation period, occurred during a heavy rainstorm with an 80‐year recurrence time. To maintain the sustainability of the reservoir in this study, therefore, temporal and spatial preparation strategies for heavy rainstorms and bank and forest road erosion should be considered. However, spatial information on sediment sources from 137Cs fingerprinting is limited. To better identify the sediment sources spatially and temporally, further studies applying soil erosion models and more detailed field studies are needed. Copyright © 2013 John Wiley & Sons, Ltd.
A re-evaluation of fifteen years of european risk assessment using effect models
Authors: De Laender Frederik , Van Sprang Patrick , Janssen Colin R.
Published: December 2012

Ecological risk assessments of chemicals can be informed by a suite of effect models, including population and food web models. In the risk assessments conducted under EU regulation 793/93/EC, however, applications of such effect models are extremely scarce and toxicity-extrapolation approaches are often used instead. The objective of the present study was to re-evaluate these risk assessments using two types of effect models: species sensitivity distributions (SSDs, non-mechanistic), and food web models (mechanistic). Species sensitivity distributions significantly fitted the available toxicity data for up to 35% of the chemicals, depending on the trophic levels included and the amount of data available. Median hazardous concentrations for 5% of the species (HC5-50) estimated by the SSDs were less accurate predictors of measured community-level no observed effect concentration than food web model-derived HC5-50s, albeit data were available for seven chemicals only. For datasets with more than 10 data points, the 90% confidence interval of the estimated HC5s was narrower for the food web modeling approach than for the SSD approach. The HC5-50s predicted by the two approaches were two to five times (metals) and 10 to 100 times (organic chemicals) higher than the predicted no effect concentrations (PNECs) for the aquatic environment listed in the risk assessment reports. This suggests that the derived PNECs are protective for aquatic ecosystems. Environ. Toxicol. Chem. 2013;32:594–601. © 2012 SETAC
Hepatitis C screening: Getting it right
Authors: Edlin Brian R.
Published: December 2012

Hepatitis C is the most prevalent bloodborne viral disease in the United States and the deadliest. This year, the U.S. Preventive Services Task Force (USPSTF) will update its 2004 hepatitis C guideline, which recommends against screening asymptomatic adults for hepatitis C. This guideline has hampered public health efforts to encourage screening and identify and refer infected persons for care by declaring that such interventions were not supported by the evidence. A draft revision of the guideline, released on November 26, 2012, concludes that testing persons born between 1945 and 1965 probably has at least a small net benefit, but stops short of definitively recommending that this cohort be screened. This article examines the Task Force's process for writing its guidelines. It recommends that the Task Force adopt a balanced approach to evaluating the benefits and harms of screening; use the preponderance of the evidence as a standard for evaluating interventions that target serious public health problems; be transparent about the value judgments that go into its decisions; consider the wide variation in disease prevalence in diverse patient populations; and recommend screening asymptomatic adults for hepatitis C.

Conclusion

: By taking a broader view of the evidence, the Task Force can write new guidelines that will serve efforts to curb the hepatitis C epidemic, rather than frustrate them.
Identification of fluvial sediment sources in the Kharaa River catchment, Northern Mongolia
Authors: Theuring Philipp , Rode Michael , Behrens Stefan , Kirchner Gerald , Jha Abhinand
Published: December 2012

Fine‐grained sediments constitute a major stressing factor for the aquatic ecosystem in the 15 000 km2 Kharaa River catchment in Northern Mongolia. The objectives of this study were to identify the suspended sediment (SS) sources and quantify the sediment budget of the basin. Sediment sources were identified with the help of sediment tracing methods utilizing Be‐7, Cs‐137 and Pb‐210 radionuclides. High‐resolution discharge data were used in combination with daily suspended solid measurements to calculate the SS budget. These calculations were compared with the monthly archive data on SS and discharge to investigate temporal load variations. In addition, the sediment budget model SedNet was used to estimate the SS budget and test its applicability in a cold semi‐arid region. Results of the sediment tracing showed that riverbank erosion generates 74.5% of the suspended sediment load, whereas surface erosion contributes 21.7% and gully erosion only 3.8%. In the most intensely used agricultural tributary catchment Zagdelin Gol, upland erosion contributed only 12.7% to the total SS losses. The calculated mean annual sediment load for the years 1990–2002 was 20.3 kt⋅a−1. The SedNet model computed SS export from the catchment in the same order of magnitude as measured data (16.2 kt⋅a−1). The results help to identify effective management measures to reduce sediment loads and mitigate its impact on the aquatic environment. Copyright © 2012 John Wiley & Sons, Ltd.
Characterization of Ni‐Coated WS2 Nanotubes for Hydrodesulfurization Catalysis
Authors: Komarneni Mallikharjuna Rao , Yu Zhongqing , Burghaus Uwe , Tsverin Yulia , Zak Alla , Feldman Yishay , Tenne Reshef
Published: December 2012

A reactivity screening of new nano‐hydrodesulfurization (HDS) catalysts was conducted using an ambient pressure flow reactor as well as ultra‐high vacuum kinetics techniques. Thiophene was used as a probe molecule. Clean multiwall WS2 nanotubes (INT‐WS2) as well as Ni‐ and Co‐coated INT‐WS2 were considered. In addition, undoped MoS2 and Re‐doped nanoparticles with fullerene‐like structures were studied. Commercial Ni and Co HDS catalysts from Haldor Topsoe (Denmark) as well as “nano MoS2” from Impex Corp. (USA) were considered as reference materials. The lab‐synthesized and commercial systems broke down thiophene into quite similar non‐sulfur containing products, as identified by a gas chromatograph. The Ni and Co promoted catalysts showed similar thiophene conversion rates. Although the commercial catalysts had larger thiophene conversion rates than the laboratory‐synthesized systems, the Re‐doped nano‐HDS catalyst showed quite low rates of formation of H2S, an undesirable by‐product.
Tip‐Induced Charging of Free Standing Semiconductor Nanowires and Carbon Nanotubes
Authors: Schäfer Sebastian , Wang Zhe , Rammelberg Holger U. , Kipp Tobias , Mews Alf
Published: December 2012

We investigate the distribution of charges injected into one‐dimensional nanostructures like semiconductor nanowires and carbon nanotubes. The charges are injected by an atomic force microscope tip and monitored by means of electrostatic force microscopy. We demonstrate that the charges distribute rapidly along the axes of both types of nanostructures. The charges deposited on nanowires are shown to migrate to the substrate on a shorter time scale than those deposited on nanotubes, while the holes migrate even slower than the electrons. This behaviour is attributed to the amount and type of available trap states in the respective nanostructure.
Recent Progress in Photocatalysis Mediated by Colloidal II‐VI Nanocrystals
Authors: Wilker Molly B. , Schnitzenbaumer Kyle J. , Dukovic Gordana
Published: December 2012

The use of photoexcited electrons and holes in semiconductor nanocrystals as reduction and oxidation reagents is an intriguing way of harvesting photon energy to drive chemical reactions. This review focuses on recent research efforts to understand and control the photocatalytic processes mediated by colloidal II‐VI nanocrystalline materials, such as cadmium and zinc chalcogenides. First, we highlight how nanocrystal properties govern the rates and efficiencies of charge‐transfer processes relevant to photocatalysis. We then describe the use of nanocrystal catalyst heterostructures for fuel‐forming reactions, most commonly H2 generation. Finally, we review the use of nanocrystal photocatalysis as a synthetic tool for metal–semiconductor nano‐heterostructures.
The vertical distribution of fish in the open water area of a deep temperate mesotrophic lake assessed by hydroacoustics and midwater trawling
Authors: Jůza Tomáš , Frouzová Jaroslava , Brämick Uwe , Draštík Vladislav , Mrkvička Tomáš , Kubečka Jan
Published: December 2012

The fish stock of a deep temperate, mesotrophic lake was sampled at different depths using a fixed‐frame fry trawl, during two nights in mid‐September 2009. Additionally, horizontal and vertical hydroacoustics were used simultaneously to evaluate fish abundance and biomass estimates obtained by the trawl. Roach Rutilus rutilus and smelt Osmerus eperlanus were the dominant species of young‐of‐the‐year (YOY) fish in the trawl catches from the surface layers (0–9 m). Bleak Alburnus alburnus dominated the catch of older fish in the upper part of the surface profile (0–6 m). Around the thermocline (9–13 m) smelt dominated the catches of both the YOY and older fish. Beneath the thermocline (13–36 m) vendace Coregonus albula dominated the catch of YOY fish, and smelt was the only species of older fish in the trawl catches. Species composition, abundance and biomass of the YOY and older fish were heterogeneous throughout the depth profiles of the lake, but only abundance differed significantly between the layers. The hydroacoustics gave relatively similar estimates of abundance and biomass to those obtained by the trawl in all the depths sampled. Our results indicate that there is a clear separation of small fish of different species along the vertical profile of a deep temperate lake during the night, and an unequal vertical distribution of fish abundance and biomass. The similarity of the trawl and hydroacoustics estimates of abundances and biomass indicated that the trawl sampling did not cause important avoidance reactions of small fish during the night in this deep temperate lake (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Understanding How Peer Mentoring and Capitalization Link STEM Students to Their Majors
Authors: Holland Jonathan M. , Major Debra A. , Orvis Karin A.
Published: December 2012

This study investigated the role of peer mentoring and voluntary self‐development activities (i.e., capitalization) in anchoring science, technology, engineering, and mathematics students to their college majors. Online data were collected from 214 undergraduate students. As hypothesized, mentoring was positively related to capitalization, and both mentoring and capitalization were positively related to satisfaction with one's major, affective commitment to one's major, involvement in one's major, and willingness to be a mentor. Contrary to expectations, capitalization did not mediate the relationship between peer mentoring and student outcomes, suggesting that these constructs contribute independently to positive outcomes. Implications and future research directions are discussed.
Validation of the Career‐Related Parent Support Scale Among Chinese High School Students
Authors: Cheng Sandra , Yuen Mantak
Published: December 2012

The Career‐Related Parent Support Scale (CRPSS; Turner, Alliman‐Brissett, Lapan, Udipi, & Ergun, 2003) was translated and modified to form the 24‐item Chinese version of the scale. As in the case of the original CRPSS, the Chinese version includes 4 subscales (Instrumental Assistance, Emotional Support, Verbal Encouragement, and Career‐Related Modeling). The Chinese version of the CRPSS was validated in this study with a sample of Hong Kong high school students (N= 677). Reliability analyses showed that the total scale and subscales were internally consistent. The results of the exploratory factor analysis and confirmatory factor analysis suggested that the Chinese version of the CRPSS provided adequate indicators of Chinese adolescents’ perceptions of parent support for their career aspirations.
Sex and age modify biochemical and skeletal manifestations of chronic hyperparathyroidism by altering target organ responses to Ca2+ and parathyroid hormone in mice
Authors: Cheng Zhiqiang , Liang Nathan , Chen Tsui-Hua , Li Alfred , Santa Maria Christian , You Michael , Ho Hanson , Song Fuqing , Bikle Daniel , Tu Chialing , Shoback Dolores , Chang Wenhan
Published: December 2012

We studied mice with or without heterozygous deletion of the Casr in the parathyroid gland (PTG) [PTGCaSR(+/–)] to delineate effects of age and sex on manifestations of hyperparathyroidism (HPT). In control mice, aging induced a left-shift in the Ca2+/parathyroid hormone (PTH) set point accompanied by increased PTG CaSR expression along with lowered serum Ca2+ and mildly increased PTH levels, suggesting adaptive responses of PTGs to aging-induced changes in mineral homeostasis. The aging effects on Ca2+/PTH set point and CaSR expression were significantly blunted in PTGCaSR(+/–) mice, who showed instead progressively elevated PTH levels with age, especially in 12-month-old females. These 12-month-old knockout mice demonstrated resistance to their high PTH levels in that serum 1,25-dihydroxyvitamin D (1,25-D) levels and RNA expression of renal Cyp27b1 and expression of genes involved in Ca2+ transport in kidney and intestine were unresponsive to the rising PTH levels. Such changes may promote negative Ca2+ balance, which further exacerbate the HPT. Skeletal responses to HPT were age-, sex-, and site-dependent. In control mice of either sex, trabecular bone in the distal femur decreased whereas cortical bone in the tibiofibular junction increased with age. In male PTGCaSR(+/–) mice, anabolic actions of the elevated PTH levels seemed to protect against trabecular bone loss at ≥3 months of age at the expense of cortical bone loss. In contrast, HPT produced catabolic effects on trabecular bone and anabolic effects on cortical bone in 3-month-old females; but these effects reversed by 12 months, preserving trabecular bone in aging mice. We demonstrate that the CaSR plays a central role in the adaptive responses of parathyroid function to age-induced changes in mineral metabolism and in target organ responses to calciotropic hormones. Restraining the ability of the PTG to upregulate CaSRs by heterozygous gene deletion contributes to biochemical and skeletal manifestations of HPT, especially in aging females. © 2013 American Society for Bone and Mineral Research.
Role of JAK2–STAT3 in TLR2‐mediated tissue factor expression
Authors: Park Dae‐Weon , Lyu Ji Hyo , Kim Jin‐Sik , Chin Haemin , Bae Yoe‐Sik , Baek Suk‐Hwan
Published: December 2012

Tissue factor (TF) is a core protein with an essential function in the coagulation cascade that maintains the homeostasis of the blood vessels. TF not only participates in neointima formation, but also causes the development of atherosclerosis. This study investigated the mechanism regulating TF expression in macrophages using Pam3CSK4, a TLR2 ligand. Pam3CSK4 induced TF expression in two types of macrophages (Raw264.7 and BMDM), but not in TLR2 KO mice derived BMDM. Pam3CSK4 induced TF expression was inhibited by pretreatment with pan‐JAK inhibitor or JAK2 inhibitor AG490. JAK2 knock‐down by siRNA inhibited Pam3CSK4 induced TF expression. Pam3CSK4 stimulated STAT3 phosphorylation (S727), while STAT3 knock‐down by siRNA reduced Pam3CSK4 induced TF expression. These results suggest that Pam3CSK4 induced TF expression is regulated by the JAK2–STAT3 signaling pathway. Pam3CSK4, unlike increased TF expression, significantly decreased RGS2 expression, while RGS2 overexpression decreased Pam3CSK4 induced TF expression. Inhibition of TF by RGS2 WT did not occur in mutants with flawed RGS domains. We also investigated the correlation between RGS2 and STAT3 phosphorylation. RGS2 knock‐down elevated Pam3CSK4 induced STAT3 phosphorylation, but RGS2 overexpression had the opposite effect on STAT3 phosphorylation. These results suggest that, while Pam3CSK4 induced TF expression is regulated by JAK2–STAT3 signaling, RGS2 is a negative regulator targeted to STAT3. J. Cell. Biochem. 114: 1315–1321, 2013. © 2012 Wiley Periodicals, Inc.
Tumor suppressor gene p16/INK4A/CDKN2A‐dependent regulation into and out of the cell cycle in a spontaneous canine model of breast cancer
Authors: Agarwal Payal , Sandey Maninder , DeInnocentes Patricia , Bird R. Curtis
Published: December 2012

p16/INK4A/CDKN2A is an important tumor suppressor gene that arrests cell cycle in G1 phase inhibiting binding of CDK4/6 with cyclin D1, leaving the Rb tumor suppressor protein unphosphorylated and E2F bound and inactive. We hypothesized that p16 has a role in exit from cell cycle that becomes defective in cancer cells. Well characterized p16‐defective canine mammary cancer cell lines (CMT28, CMT27, and CMT12), derived stably p16‐transfected CMT cell clones (CMT27A, CMT27H, CMT28A, and CMT28F), and normal canine fibroblasts (NCF), were used to investigate expression of p16 after serum starvation into quiescence followed by re‐feeding to induce cell cycle re‐entry. The parental CMT cell lines used lack p16 expression either at the mRNA or protein expression levels, while p27 and other p16‐associated proteins, including CDK4, CDK6, cyclin D1, and Rb, were expressed. We have successfully demonstrated cell cycle arrest and relatively synchronous cell cycle re‐entry in parental CMT12, CMT28 and NCF cells as well as p16 transfected CMT27A, CMT27H, CMT28A, and CMT28F cells and confirmed this by3H‐thymidine incorporation and flow cytometric analysis of cell cycle phase distribution. p16‐transfected CMT27A and CMT27H cells exited cell cycle post‐serum‐starvation in contrast to parental CMT27 cells. NCF, CMT27A, and CMT28F cells expressed upregulated levels of p27 and p16 mRNA, post‐serum starvation, as cells exited cell cycle and entered quiescence. Because quiescence and differentiation are associated with increased levels of p27, our data demonstrating that p16 was upregulated along with p27 during quiescence, suggests a potential role for p16 in maintaining these non‐proliferative states. J. Cell. Biochem. 114: 1355–1363, 2013. © 2012 Wiley Periodicals, Inc.
Reply to ‘comment on “extending Hirshfeld‐I to bulk and periodic materials”’
Authors: Vanpoucke Danny E. P. , Van Driessche Isabel , Bultinck Patrick
Published: December 2012

The issues raised in the comment by Manz are addressed through the presentation of calculated atomic charges for NaF, NaCl, MgO, SrTiO$$_3$$, and La$$_2$$Ce$$_2$$O$$_7$$, using our previously presented method for calculating Hirshfeld‐I charges in solids (Vanpoucke et al., J. Comput. Chem. doi: 10.1002/jcc.23088). It is shown that the use of pseudovalence charges is sufficient to retrieve the full all‐electron Hirshfeld‐I charges to good accuracy. Furthermore, we present timing results of different systems, containing up to over 200 atoms, underlining the relatively low cost for large systems. A number of theoretical issues are formulated, pointing out mainly that care must be taken when deriving new atoms in molecules methods based on “expectations” for atomic charges. © 2012 Wiley Periodicals, Inc.
New insight into the electronic structure of iron(IV)‐oxo porphyrin compound I. A quantum chemical topological analysis
Authors: Viciano Ignacio , Berski Slawomir , Martí Sergio , Andrés Juan
Published: December 2012

The electronic structure of iron‐oxo porphyrin π‐cation radical complex Por·+FeIVO (SH) has been studied for doublet and quartet electronic states by means of two methods of the quantum chemical topology analysis: electron localization function (ELF) η(r) and electron density ρ(r). The formation of this complex leads to essential perturbation of the topological structure of the carbon–carbon bonds in porphyrin moiety. The double CC bonds in the pyrrole anion subunits, represented by pair of bonding disynaptic basins Vi=1,2(C,C) in isolated porphyrin, are replaced by single attractor V(C,C)i=1–20after complexation with the Fe cation. The iron–nitrogen bonds are covalent dative bonds, N→Fe, described by the disynaptic bonding basins V(Fe,N)i=1–4, where electron density is almost formed by the lone pairs of the N atoms. The nature of the iron–oxygen bond predicted by the ELF topological analysis, shows a main contribution of the electrostatic interaction, Feδ+···Oδ−, as long as no attractors between the C(Fe) and C(O) core basins were found, although there are common surfaces between the iron and oxygen basines and coupling between iron and oxygen lone pairs, that could be interpreted as a charge‐shift bond. The FeS bond, characterized by the disynaptic bonding basin V(Fe,S), is partially a dative bond with the lone pair donated from sulfur atom. The change of electronic state from the doublet (M= 2) to quartet (M= 4) leads to reorganization of spin polarization, which is observed only for the porphyrin skeleton (−0.43e to 0.50e) and SH bond (−0.55e to 0.52e). © 2012 Wiley Periodicals, Inc.
PSYCHOSOCIAL STRENGTHS AND NEEDS OF LOW‐INCOME SUBSTANCE ABUSERS IN RECOVERY
Authors: Mendelson Tamar , Dariotis Jacinda K. , Agus Deborah
Published: December 2012

Psychosocial heterogeneity among recovering substance users is not well understood. Cluster analysis was used to identify subgroups with distinct psychosocial profiles among a low‐income sample attending a community recovery center (n= 151). Psychosocial characteristics assessed included depressive symptoms, perceived social support, self‐efficacy, and coping. A 3‐cluster solution explained the most variance in the constructs assessed (R2= 0.72). The largest cluster (38.4% of the sample) was characterized as “distressed,” with high emotional distress and few psychosocial resources. The second largest (34.2%) was characterized as “adjusted” because of its generally positive pattern of psychosocial functioning. The smallest (27.4%) was characterized as “resilient” because this cluster displayed emotional strengths despite low perceived social support. Findings have implications for tailoring interventions for this vulnerable population.
VIOLENCE THROUGH THE EYES OF YOUTH: A PHOTOVOICE EXPLORATION
Authors: Chonody Jill , Ferman Barbara , Amitrani‐Welsh Jill , Martin Travis
Published: December 2012

In 2001 the CDC declared youth violence a public health issue. In summer 2008, we embarked on a project designed to explore the issue of violence from the standpoint of youth who are exposed to and affected by violence in their communities. Using photovoice as the primary methodology, the project sought to develop a more nuanced and deeper understanding of these issues, while simultaneously giving youth a voice and further developing their critical thinking skills. Digital images produced by the youth and the subsequent structured conversations focused on representations of violence, causes of violence and ways to address violence. Analyses of the images and conversations, especially in the context of the literatures on youth violence, race and poverty, support the utility of photovoice as a tool for understanding how youth perceive violence and underscore the need to listen to the voices of those affected by violence.