bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of microglial neurotoxicity by ethanol extract of Artemisia asiatica Nakai
Authors: Lim Beong Ou , Chung Hae Gon , Lee Won‐Ha , Lee Ho Won , Suk Kyoungho 
Published: September 2007

AbstractArtemisia asiatica Nakai has been used for the treatment of infections and inflammatory disorders in traditional Oriental medicine. Previously, an ethanol extract of A. asiatica has been shown to exert antioxidative and antiinflammatory activities and to exhibit protective effects against experimentally induced damage in the gastrointestinal system, liver and pancreas. This study examined whether the ethanol extract of A. asiatica affects inflammatory activation of microglia in the central nervous system, and whether the antiinflammatory activity of A. asiatica is related to neuroprotective effects. The extract of A. asiatica inhibited inflammatory activation of mouse microglial cells as determined by the production of nitric oxide and the expression of inducible nitric oxide synthase and inflammatory cytokine. The extract also protected nerve growth factor‐differentiated PC12 cells against microglial cytotoxicity, indicating that the ethanol extract of A. asiatica may be neuroprotective by inhibiting microglial neurotoxicity. Copyright © 2007 John Wiley & Sons, Ltd.
Effective error correction method for quantum information processing
Authors: Kawamura Minaru , Morimoto Takuji , Mori Yoshiyuki , Sawae Ryuichi , Takarabe Kenichi , Manmoto Yoshinori , Sakata Toshio 
Published: September 2007

AbstractIn this paper we present an effective error correction method to correct the errors that occur during quantum information processing. (There are various methods of quantum error correction such as error correcting code or decoherence free subspace which protect quantum information from noise, and they are useful for storage and communication; however, it would be difficult to adapt them to quantum information processing practically.) In this method the error detection is carried out through the asymmetry or the irreversibility of quantum computers, which ought to be inherently symmetric and reversible. The irreversibility is usually caused by decoherence and dissipation, and the processing's own adjoint operator can, therefore, be used to condense such errors and enable their detection. The effectiveness of this method is investigated with an NMR quantum computer. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Decomposition of deformation density into orbital components
Authors: Pakiari A. H. , Fakhraee S. , Azami S. M. 
Published: September 2007

AbstractIn this research, deformation density matrix has been introduced as matrix representation of the density difference between the complex and fragments. The deformation density matrix is then diagonalized to obtain the magnitude of displaced charges as eigenvalues. Correspondingly, the eigenvectors reveal the spaces responsible for reorganization of the electrons because of the complex formation. The formalism has been applied on some CO2planar clusters, and the results showed that how the deformation density can be successfully separated into in‐plane and out‐of‐plane contributions. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Disappearance of interfering alkali‐metal adducted peaks from matrix‐assisted laser desorption/ionization mass spectra of peptides with serine addition to α‐cyano‐4‐hydroxycinnamic acid matrix
Authors: Nishikaze Takashi , Takayama Mitsuo 
Published: September 2007

AbstractIt has been described that ion yield in both positive‐ and negative‐ion matrix‐assisted laser desorption/ionization mass spectrometry (MALDI MS) of peptides is often inhibited by trace amounts of alkali metals and that the MALDI mass spectra are contaminated by the interfering peaks originating from traces of alkali metals, even when sample preparation is carefully performed. Addition of serine to the commonly used MALDI matrix α‐cyano‐4‐hydroxycinnamic acid (CHCA) significantly improved and enhanced the signals of both protonated and deprotonated peptides, [M+H]+ and [M−H]−. The addition of serine to CHCA matrix eliminated the alkali‐metal ion adducts, [M+Na]+ and [M+K]+, and the CHCA cluster ions from the mass spectra. Serine and serinephosphate as additives to CHCA enhanced and improved the formation of molecular‐related ions of phosphopeptides in negative‐ion MALDI mass spectra. Copyright © 2007 John Wiley & Sons, Ltd.
Mendelian randomization: Using genes as instruments for making causal inferences in epidemiology
Authors: Lawlor Debbie A. , Harbord Roger M. , Sterne Jonathan A. C. , Timpson Nic , Davey Smith George 
Published: September 2007

AbstractObservational epidemiological studies suffer from many potential biases, from confounding and from reverse causation, and this limits their ability to robustly identify causal associations. Several high‐profile situations exist in which randomized controlled trials of precisely the same intervention that has been examined in observational studies have produced markedly different findings. In other observational sciences, the use of instrumental variable (IV) approaches has been one approach to strengthening causal inferences in non‐experimental situations. The use of germline genetic variants that proxy for environmentally modifiable exposures as instruments for these exposures is one form of IV analysis that can be implemented within observational epidemiological studies. The method has been referred to as ‘Mendelian randomization’, and can be considered as analogous to randomized controlled trials. This paper outlines Mendelian randomization, draws parallels with IV methods, provides examples of implementation of the approach and discusses limitations of the approach and some methods for dealing with these. Copyright © 2007 John Wiley & Sons, Ltd.
Incorporating intermediate binary responses into interim analyses of clinical trials: A comparison of four methods
Authors: Whitehead Anne , Sooriyarachchi Marina Roshini , Whitehead John , Bolland Kim 
Published: September 2007

AbstractIn clinical trials with a long period of time between randomization and the primary assessment of the patient, the same assessments are often undertaken at intermediate times. When an interim analysis is conducted, in addition to the patients who have completed the primary assessment, there will be those who have till then undergone only intermediate assessments. The efficiency of the interim analysis can be increased by the inclusion of data from these additional patients. This paper compares four methods of increasing information based on model‐free estimates of transition probabilities to incorporate intermediate assessments from patients who have not completed the trial. It is assumed that
the observations are binary and that there is one intermediate assessment. The methods are the score and Wald approaches, each with the log‐odds ratio and probability difference parameterizations. Simulations show that all four approaches have good properties in moderate to large sample sizes. Copyright © 2007 John Wiley & Sons, Ltd.
Stopping rules for surveys with multiple waves of nonrespondent follow‐up
Authors: Rao R. Sowmya , Glickman Mark E. , Glynn Robert J. 
Published: September 2007

AbstractIn surveys with multiple waves of follow‐up, nonrespondents to the first wave are sometimes followed intensively but this does not guarantee an increase in the response rate or an appreciable change in the estimate of interest. Most prior research has focused on stopping rules for Phase I clinical trials. To our knowledge there are no standard methods to stop follow‐up in observational studies. Previous research suggests optimal stopping strategies where decisions are based on achieving a given precision for minimum cost or reducing cost for a given precision. In this paper, we propose three stopping rules that are based on assessing whether successive waves of sampling provide evidence that the parameter of interest is changing. Two of the rules rely on examining patterns of observed responses while the third rule uses missing data methods to multiply impute missing responses. We also present results from a simulation study to evaluate our proposed methods. Our simulations suggest that rules that adjust for nonresponse are preferred for decisions to discontinue follow‐up since they reduce bias in the estimate of interest. The rules are not complicated and may be applied in a straightforward manner. Discontinuing follow‐up would save time and possibly resources, and adjusting for the nonresponse in the analysis would reduce the impact of nonresponse bias. Copyright © 2007 John Wiley & Sons, Ltd.
Risk Factors for Recurrence to the Lymph Node in Papillary Thyroid Carcinoma Patients without Preoperatively Detectable Lateral Node Metastasis: Validity of Prophylactic Modified Radical Neck Dissection
Authors: Ito Yasuhiro , Higashiyama Takuya , Takamura Yuuki , Miya Akihiro , Kobayashi Kaoru , Matsuzuka Fumio , Kuma Kanji , Miyauchi Akira 
Published: September 2007

AbstractBackgroundAlthough papillary carcinoma usually shows mild characteristics, it metastasizes and shows recurrence to the lymph node in high incidences. Of the two representative lymph node compartments to which papillary carcinoma metastasizes, the central compartment can be routinely dissected via the surgical incision made for thyroidectomy. However, the routine application of prophylactic lateral node dissection (modified radical neck dissection [MND]) remains controversial. In this study, we investigated risk factors for lymph node recurrence of papillary carcinoma to determine the appropriate application of prophylactic MND.MethodsWe investigated risk factors for lymph node recurrence in 1,231 patients without preoperatively detectable lateral node metastasis who underwent thyroidectomy, central node dissection, and prophylactic MND for papillary carcinoma between 1987 and 1995.ResultsThe incidence of lateral node metastasis and the number of metastatic lateral nodes significantly increased with carcinoma size. The lymph node disease‐free survival (LN‐DFS) was also significantly worse in carcinoma with a maximal diameter greater than 3 cm. Massive extrathyroid extension, male gender, and age 55 years or older also reflected a poorer LN‐DFS. The 10‐year LN‐DFS rates of patients with carcinoma having two and three or four of these features were low at 88.5% and 64.7%, respectively, although the rates of those with carcinoma having no or only one characteristic were better than 95%.ConclusionsProphylactic MND is recommended for cases of papillary carcinoma demonstrating two or more of the following four characteristics; male gender, age 55 years or older, maximal tumor diameter larger than 3 cm, and massive extrathyroid extension.
From individual interactions to population dynamics: individual resource partitioning simulation exposes the causes of nonlinear intra‐specific competition
Authors: Johst Karin , Berryman Alan , Lima Mauricio 
Published: September 2007

AbstractIntra‐specific competition defines the relationship between population density and the performance of individual organisms (R‐function). Observation of this relationship in nature shows it to be frequently nonlinear, and it has been argued, on intuitive grounds, that this nonlinearity is due to the type of competition (scramble or contest) being expressed. Here, we use an individual‐based simulation model to investigate the effects of three resource partitioning schemes, representing different types of competition, on the form of the R‐function. Results indicate that all resource partitioning schemes can give rise to concave or convex functions depending on the balance between maximum individual birth rate, maintenance cost, and demand for resources. Given high growth rates and maintenance costs, contest competitors tend to exhibit less concavity than scramblers. Therefore, population stability can be strongly affected by the strategy of resource partitioning. Life histories and environmental conditions that encourage the homogeneous distribution of resources among individuals lead to complex and unstable dynamics. Stable dynamics is fostered by heterogeneous resource distribution, which could result from such things as social hierarchies, individual and environmental variability, and large, indivisible resource packets.
How motivation, opportunity, and ability drive knowledge sharing: The constraining‐factor model
Authors: Siemsen Enno , Roth Aleda V. , Balasubramanian Sridhar 
Published: September 2007

AbstractWe introduce and empirically test a theoretical metamodel that explains knowledge‐sharing behavior among employees. Building on the well‐established motivation–opportunity–ability (MOA) framework, we posit that knowledge sharing among employees is a function of their MOA to do so. Existing literature suggests that the interaction among motivation, opportunity, and ability drives knowledge‐sharing behavior. In contrast, we specify a new model in which the “bottleneck” or constraining factor among the MOA variables determines the degree of knowledge sharing that occurs. This constraining‐factor model (CFM) fits the data better than the traditional multiplicative model and reveals a new, qualitatively different portrait of knowledge sharing that resolves some of the puzzles in the previous literature. The CFM provides macro‐level insights with respect to how operations managers can improve employee knowledge sharing by focusing on the bottleneck MOA variable. As a result, the CFM can help set strategic directions of related policies. The model emphasizes that, counter to conventional wisdom, the MOA variables should not be addressed independently, but rather in a dynamic and coordinated way.
Charcot–Marie–Tooth type 4B demyelinating neuropathy: deciphering the role of MTMR phosphatases
Authors: Previtali Stefano C. , Quattrini Angelo , Bolino Alessandra 
Published: September 2007

AbstractCharcot–Marie–Tooth type 4B (CMT4B) is a severe autosomal recessive neuropathy with demyelination and myelin outfoldings of the nerve. This disorder is genetically heterogeneous, but thus far, mutations in myotubularin-related 2 (MTMR2) andMTMR13genes have been shown to underlie CMT4B1 and CMT4B2, respectively. MTMR2 and MTMR13 belong to a family of ubiquitously expressed proteins sharing homology with protein tyrosine phosphatases (PTPs). The MTMR family, which has 14 members in humans, comprises catalytically active proteins, such as MTMR2, and catalytically inactive proteins, such as MTMR13. Despite their homology with PTPs, catalytically active MTMR phosphatases dephosphorylate both PtdIns3Pand PtdIns(3,5)P2phosphoinositides. Thus, MTMR2 and MTMR13 may regulate vesicular trafficking in Schwann cells. Loss of these proteins could lead to uncontrolled folding of myelin and, ultimately, to CMT4B. In this review, we discuss recent findings on this interesting protein family with the main focus on MTMR2 and MTMR13 and their involvement in the biology of Schwann cell and CMT4B neuropathies.
Soil eukaryotic functional diversity, a metatranscriptomic approach
Authors: Bailly Julie , Fraissinet-Tachet Laurence , Verner Marie-Christine , Debaud Jean-Claude , Lemaire Marc , Wésolowski-Louvel Micheline , Marmeisse Roland 
Published: September 2007

Abstract
To appreciate the functional diversity of communities of soil eukaryotic micro-organisms we evaluated an experimental approach based on the construction and screening of a cDNA library using polyadenylated mRNA extracted from a forest soil. Such a library contains genes that are expressed by each of the different organisms forming the community and represents its metatranscriptome. The diversity of the organisms that contributed to this library was evaluated by sequencing a portion of the 18S rDNA gene amplified from either soil DNA or reverse-transcribed RNA. More than 70% of the sequences were from fungi and unicellular eukaryotes (protists) while the other most represented group was the metazoa. Calculation of richness estimators suggested that more than 180 species could be present in the soil samples studied. Sequencing of 119 cDNA identified genes with no homologues in databases (32%) and genes coding proteins involved in different biochemical and cellular processes. Surprisingly, the taxonomic distribution of the cDNA and of the 18S rDNA genes did not coincide, with a marked under-representation of the protists among the cDNA. Specific genes from such an environmental cDNA library could be isolated by expression in a heterologous microbial host, Saccharomyces cerevisiae. This is illustrated by the functional complementation of a histidine auxotrophic yeast mutant by two cDNA originating possibly from an ascomycete and a basidiomycete fungal species. Study of the metatranscriptome has the potential to uncover adaptations of whole microbial communities to local environmental conditions. It also gives access to an abundant source of genes of biotechnological interest.
The geomicrobiology of gold
Authors: Reith Frank , Lengke Maggy F , Falconer Donna , Craw David , Southam Gordon 
Published: September 2007

Abstract
Microorganisms capable of actively solubilizing and precipitating gold appear to play a larger role in the biogeochemical cycling of gold than previously believed. Recent research suggests that bacteria and archaea are involved in every step of the biogeochemical cycle of gold, from the formation of primary mineralization in hydrothermal and deep subsurface systems to its solubilization, dispersion and re-concentration as secondary gold under surface conditions. Enzymatically catalysed precipitation of gold has been observed in thermophilic and hyperthermophilic bacteria and archaea (for example, Thermotoga maritime, Pyrobaculum islandicum), and their activity led to the formation of gold- and silver-bearing sinters in New Zealand's hot spring systems. Sulphate-reducing bacteria (SRB), for example, Desulfovibrio sp., may be involved in the formation of gold-bearing sulphide minerals in deep subsurface environments; over geological timescales this may contribute to the formation of economic deposits. Iron- and sulphur-oxidizing bacteria (for example, Acidothiobacillus ferrooxidans, A. thiooxidans) are known to breakdown gold-hosting sulphide minerals in zones of primary mineralization, and release associated gold in the process. These and other bacteria (for example, actinobacteria) produce thiosulphate, which is known to oxidize gold and form stable, transportable complexes. Other microbial processes, for example, excretion of amino acids and cyanide, may control gold solubilization in auriferous top- and rhizosphere soils. A number of bacteria and archaea are capable of actively catalysing the precipitation of toxic gold(I/III) complexes. Reductive precipitation of these complexes may improve survival rates of bacterial populations that are capable of (1) detoxifying the immediate cell environment by detecting, excreting and reducing gold complexes, possibly using P-type ATPase efflux pumps as well as membrane vesicles (for example, Salmonella enterica, Cupriavidus (Ralstonia) metallidurans, Plectonema boryanum); (2) gaining metabolic energy by utilizing gold-complexing ligands (for example, thiosulphate by A. ferrooxidans) or (3) using gold as metal centre in enzymes (Micrococcus luteus). C. metallidurans containing biofilms were detected on gold grains from two Australian sites, indicating that gold bioaccumulation may lead to gold biomineralization by forming secondary ‘bacterioform’ gold. Formation of secondary octahedral gold crystals from gold(III) chloride solution, was promoted by a cyanobacterium (P. boryanum) via an amorphous gold(I) sulphide intermediate. ‘Bacterioform’ gold and secondary gold crystals are common in quartz pebble conglomerates (QPC), where they are often associated with bituminous organic matter possibly derived from cyanobacteria. This may suggest that cyanobacteria have played a role in the formation of the Witwatersrand QPC, the world's largest gold deposit.
Assessing the restorative value of the environment: A study on the elderly in comparison with young adults and adolescents
Authors: Berto Rita 
Published: September 2007

Nature is not only appreciated for its aesthetic characteristics, but is also a useful resource for people. It plays an important role in the process of attention restoration and recovery from stress. Young adults and adolescents assess natural environments as being more restorative than built environments. This study sought to test whether natural environments are more restorative than built environments for the elderly as well. The study is made up of two phases: (1) an empirical study with the elderly, (2) a comparison of data from the elderly with two earlier studies of adolescents and young adults. To achieve this aim a group of 50 elderly people (age range: 62–93 years) was asked to rate the restorative value of 10 pictures of environments ranging from natural to built, covering 5 environmental categories: housing, industrial zone, city streets, hills, and lakes. Each picture was assessed using the Perceived Restorativeness Scale. Participants were from three living situations: elderly living in a place for old people located in a green area (N = 18), elderly living in a place for old people located in an urban area (N = 20), and elderly living in their own homes (N = 12). Results showed that all three groups of the elderly evaluated the natural environments as more restorative than the built environments. The elderly data were then compared with the data from a sample of adolescents (N = 60, age range: 11–14 years) and of young adults (N = 100, age range: 18–29 years). All three groups rated natural environments as more restorative than built environments. The evaluation of preference and familiarity, however, differed between age groups, with adolescence being less familiar with and less in favour of natural environments than young adults and the elderly. Restorativeness and preference were correlated among all age groups, while familiarity and restorativeness were correlated only among the elderly.
Comorbid Psychiatric Diagnoses and Their Association with Cocaine‐Induced Psychosis in Cocaine‐Dependent Subjects
Authors: Tang Yi‐Lang , Kranzler Henry R. , Gelernter Joel , Farrer Lindsay A. , Cubells Joseph F. 
Published: September 2007

Comorbidity between drug abuse and mental illness is very common, but the association of such comorbidity with specific responses to drugs of abuse remains obscure. The current study examined the relationship between the presence of non‐psychotic Axis I psychiatric diagnoses and the frequency and severity of cocaine‐induced psychosis. We interviewed 243 unrelated cocaine‐dependent adults [37% European American (EA), 52.3% African American (AA); 58.8% male] using the Semi‐Structured Assessment for Drug Dependence and Alcoholism (SSADDA) to establish DSM‐IV diagnoses, and two instruments for the identification of cocaine‐induced paranoia, the Cocaine Experience Questionnaire (CEQ) and the Scale for Assessment of Positive Symptoms for Cocaine‐Induced Psychosis (SAPS‐CIP). Comorbid substance use and psychiatric disorders were common in this cocaine‐dependent sample. Ninety percent of subjects met criteria for substance use disorders other than cocaine dependence; common non‐substance‐use disorders included antisocial personality disorder (ASPD), adult ASPD, major depression, and attention deficit‐hyperactivity disorder (ADHD). Comorbid opioid dependence was more common in EA subjects than in AA participants. After correction for multiple comparisons, a lifetime diagnosis of ADHD was associated with the categorical presence of CIP (p = 0.007), as well as significantly more severe CIP symptoms. Comorbid substance use and psychiatric disorders are very common among individuals with cocaine dependence. Comorbid ADHD increases the odds of an individual endorsing CIP, suggesting some common basis for these phenomena.