bluuebunny/crossref_metadata_2025 huggingface dataset:
On the response of convectively unstable flows to oscillatory forcing with application to liquid sheets
Authors: Barlow N. S. , Weinstein S. J. , Helenbrook B. T.
Published: April 2012

The complete integral solution is found for the convectively unstable and oscillatory-forced linear Klein–Gordon equation as a function of spatial variable, $x$, and time, $t$. A comparison of the integral solution with series solutions of the Klein–Gordon equation elucidates salient features of both the transient and long-time spatially growing solutions. A rigorous method is developed for identifying the key $x/ t$ rays associated with saddle points that can be used to characterize the transition between transient temporally growing and long-term spatially growing waves. This method effectively combines the procedure given by Gordillo & Pérez-Saborid (Phys. Fluids, vol. 14, 2002, pp. 4329–4343) for determining the $x/ t$ ray at which the forced spatial growth response affects the observed waveform and competes with the transient response, with an established methodology for identifying the leading and trailing edge rays of an impulse response. The method is applied to a linearized system describing an oscillatory-forced liquid sheet and asymptotic predictions are obtained. Series solutions are used to validate these predictions. We establish that the portion of the solution responsible for spatial growth in the signalling problem is correctly identified by Gordillo & Pérez-Saborid (Phys. Fluids, vol. 14, 2002, pp. 4329–4343), and that this interpretation is in contrast with the classical literature. The approach provided here can be applied in multiple ways to study a convectively unstable oscillatory-forced medium. In cases where numerical or series solutions are readily available, the proposed method is used to extract key features of the solution. In cases where only the forced long time behaviour is needed, the dispersion relation is used to extract: (i) the time required to see the forced solution; (ii) the amplitude, phase and spatial growth of the forced solution; and (iii) the breadth of the transient.
Alternative proofs of four stability properties of rigid-link manipulators under PID position control
Authors: Kikuuwe Ryo
Published: April 2012

This paper presents new proofs of four stability properties (semiglobal strict passivity, semiglobal asymptotic stability, semiglobal input-to-state stability, and semiglobal uniform ultimate boundedness with an arbitrarily reducible ultimate bound) of a rigid-link manipulator under proportional-integral-derivative (PID) position control. The proofs employ a strict Lyapunov function and a novel parameterization to provide four inequality conditions for the stability properties. In those inequalities, arithmetic operations on physical quantities are physically consistent if the joints are all revolute or all prismatic. A gain selection procedure is presented by which the ultimate bounds of velocity error, position error, and its integral can be independently designed.
Carbapenem-susceptible Acinetobacter baumannii carrying the ISAba1 upstream blaOXA-51-like gene in Porto Alegre, southern Brazil
Authors: PAGANO M. , MARTINS A. F. , MACHADO A. B. M. P. , BARIN J. , BARTH A. L.
Published: April 2012

Over the last decade, Acinetobacter baumannii resistant to carbapenems has emerged in many medical centres and is commonly associated with high morbidity and mortality. We investigated potential mechanisms contributing to antimicrobial resistance of 58 clinical isolates of A. baumannii collected during a prolonged city-wide outbreak in five different hospitals in southern Brazil. The integrase gene was detected in 51 (87·9%) isolates of which 36 harboured class 2 integrons alone and 14 had both class 1 and 2 integrons; all carbapenem-resistant isolates displayed class 2 integrons. ISAba1 was found upstream of blaOXA-23-like only in isolates resistant to carbapenems; however, ISAba1 upstream of blaOXA-51-like was present in both susceptible and resistant isolates. This is the first report of a high prevalence of class 2 integrons in A. baumannii in southern Brazil. Moreover, our study suggests that ISAba1/blaOXA-51-like alone is insufficient to confer resistance to carbapenems.
Newcomer Conformity
Authors: Täuber Susanne , Sassenberg Kai
Published: April 2012

The present research is the first to examine the impact of self-construal on newcomers’ motivation to conform with the goals of a novel group. We argue that when social identity (i.e., individuals’ concern for a specific group) has not yet been developed, newcomers rely on self-construal (i.e., individuals’ chronic concern for ingroups and connectedness with others in general) to derive norms for group-serving vs. self-serving behavior. Results of an experiment (N = 157) supported this prediction: Self-construal moderated the relationship between group goals and individual goals (cognitive conformity) as well as the relationship between group goals and members’ effort (behavioral conformity). Specifically, low independent and high interdependent self-construal was associated with greater cognitive and behavioral alignment of the self with the group compared to high independent and low interdependent self-construal. Findings are discussed regarding the role of self-construal as a precedent of conformity.
A precise search for drastic temperature shifts of the past 40,000 years in southeastern Europe
Authors: Ménot Guillemette , Bard Edouard
Published: April 2012

Climatic models simulate abrupt oscillations that are associated, in the North Atlantic, with Dansgaard‐Oeschger and Heinrich events. However, the geographic extension of temperature anomalies is largely uncontrolled due to the scarcity of quantitative records of sufficient time resolution on the European continent. Here, we propose, based on a recently developed temperature proxy (TEX86), a reconstruction of millennial‐scale temperature variations in a Black Sea sediment archive for the last 40,000 years. Prior to any paleoclimatological interpretations the effects of potential bias, such as seasonality and depth of maximum export production on temperature reconstructions, are considered for the Black Sea. Based on previous work, a tentative method for temperature corrections, taking into account varying terrigenous inputs, is further proposed. Reconstructed temperatures for Black Sea core MD042790 were remarkably stable during the last glacial. However, significant shifts toward lower temperatures of 2°C occurred during Heinrich events 2 and 3. The deglaciation displayed a temperature increase of 10°C consistent with neighboring European reconstructions. A Younger Dryas cooling of approximately 5–6°C was clearly expressed in the reconstruction. In notable contrast to observations from nearby archives, Heinrich events imprinted our glacial temperature record consistent with a strong reorganization of oceanic circulation and a large spreading of the temperature anomaly from the North Atlantic toward the southeast. Furthermore, in contrast to high‐latitude records, our Black Sea record lacks the signatures of Dansgaard‐Oeschger interstadials, suggesting a decreasing temperature gradient away from the North Atlantic.
Deciphering how the chromatin factor RCC1 recognizes the nucleosome: the importance of individuals in the scientific discovery process
Authors: Tan Song
Published: April 2012

The nucleosome repeating unit of chromatin is the target of chromatin enzymes and factors that regulate gene activity in a eukaryotic cell. How the nucleosome is recognized by chromatin enzymes and factors is poorly understood, even though such interaction is fundamental to gene regulation and chromatin biology. My laboratory recently determined the structural basis for how the RCC1 (regulator of chromosome condensation 1) chromatin factor binds to the nucleosome, including the first atomic crystal structure of a chromatin protein complexed with the nucleosome core particle. I describe here how we developed and investigated structural models for RCC1 binding to the nucleosome using biochemical methods and how we crystallized the 300 kDa complex of RCC1 with the nucleosome core particle. This article highlights the contributions made by key laboratory members and explains our thinking and rationale during the discovery process.
Structural and dynamic aspects of Ca2+ and Mg2+ binding of the regulatory domains of the Na+/Ca2+ exchanger
Authors: Breukels Vincent , Touw Wouter G. , Vuister Geerten W.
Published: April 2012

Intracellular Ca2+ regulates the activity of the NCX (Na+/Ca2+ exchanger) through binding to the cytosolic CBD (Ca2+-binding domain) 1 and CBD2. In vitro studies of the structure and dynamics of CBD1 and CBD2, as well as studies of their kinetics and thermodynamics of Ca2+ binding, greatly enhanced our understanding of NCX regulation. We describe the fold of the CBDs in relation to other known structures and review Ca2+ binding of the different CBD variants from a structural perspective. We also report on new findings concerning Mg2+ binding to the CBDs and finally we discuss recent results on CBD1–CBD2 interdomain interactions.
Insights into the activation mechanism of the visual receptor rhodopsin
Authors: Smith Steven O.
Published: April 2012

Recent advances in the structural biology of GPCRs (G-protein-coupled receptors) have provided insights into their structure and function. Comparisons of the visual and ligand-activated receptors highlight the unique elements of rhodopsin that allow it to function as a highly sensitive dim-light photoreceptor in vertebrates, as well as the common elements that it shares with the large class A GPCR family. However, despite progress, a number of questions remain unanswered about how these receptors are activated.
14-3-3 protein and ATRAP bind to the soluble class IIB phosphatidylinositol transfer protein RdgBβ at distinct sites
Authors: Cockcroft Shamshad , Garner Kathryn
Published: April 2012

PITPs (phosphatidylinositol transfer proteins) are characterized by the presence of the PITP domain whose biochemical properties of binding and transferring PI (phosphatidylinositol) are well studied. Despite their wide-spread expression in both unicellular and multicellular organisms, they remain functionally uncharacterized. An emerging theme is that individual PITPs play highly specific roles in either membrane trafficking or signal transduction. To identify specific roles for PITPs, identification of interacting molecules would shed light on their molecular function. In the present paper, we describe binding partners for the class IIB PITP RdgBβ (retinal degeneration type Bβ). RdgBβ is a soluble PITP but is unique in that it contains a region of disorder at its C-terminus following its defining N-terminal PITP domain. The C-terminus of RdgBβ is phosphorylated at two serine residues, Ser274 and Ser299, which form a docking site for 14-3-3 proteins. Binding to 14-3-3 proteins protects RdgBβ from degradation that occurs at the proteasome after ubiquitination. In addition to binding 14-3-3, the PITP domain of RdgBβ interacts with the Ang II (angiotensin II)-associated protein ATRAP (Ang II receptor-associated protein). ATRAP is also an interacting partner for the AT1R (Ang II type 1 receptor). We present a model whereby RdgBβ functions by being recruited to the membrane by ATRAP and release of 14-3-3 from the C-terminus allows the disordered region to bind a second membrane to create a membrane bridge for lipid transfer, possibly under the control of Ang II.
Perceptual and Cognitive Characteristics of Common Playing Cards
Authors: Olson Jay A , Amlani Alym A , Rensink Ronald A
Published: April 2012

We examined the perceptual and cognitive characteristics of the playing cards commonly used in the Western world. Specifically, we measured their visibility, memorability, likability, and verbal and visual accessibility. Based on visibility and memorability, four groups of cards were distinguished: the Ace of Spades, other Aces, number cards, and face cards. Within each of these groups, there were few differences due to value or suit. Based on likability and accessibility, three additional groups were distinguished: the Ace of Hearts, Queen of Hearts, and King of Hearts. Several interesting relations were found between how people remember, like, and access cards; some of these were similar to effects found in studies of visual perception, while others seemed entirely new. Our results demonstrate that rigorous examination of real-world stimuli can shed light on the perception of ordinary objects, as well as help us understand why magic works in the mind.
Psychophysiological responses to cooperation: The role of outcome and gender
Authors: Moya‐Albiol Luis , De Andrés‐García Sara , Sanchis‐Calatayud María Victoria , Sariñana‐González Patricia , Ruiz‐Robledillo Nicolás , Romero‐Martínez Ángel , González‐Bono Esperanza
Published: April 2012

Instances of sustained cooperative behaviour in humans can be considered as an adaptive strategy that enhances the probability of reaching a goal. This study investigates psychophysiological responses to cooperation in healthy subjects, while considering outcome and gender as potential moderators of these responses. Salivary cortisol levels (Csal), heart rate (HR), skin conductance level (SCL), nonspecific skin conductance responses (NSRs), and mood states were measured at different points before, during and after a Lego house‐building task in undergraduate men (n = 22) and women (n = 20). Once the task was finished, the experimenter informed the participants about the outcome obtained (positive or negative). Cooperation produces an increase in HR, SCL, and NSR responses. When the outcome is positive it produces a gradual diminution in Csal levels, but when the outcome is negative there is a significant increase in Csal levels after the task followed by a progressive decrease. Men with positive outcomes showed a lower area under curve (AUC) in Csal than women with a negative outcome. Men had more NSR responses in all periods other than the rest period. Several mood states are differently affected by the combined effect of outcome and gender. Our laboratory results can be generalized to other situations in which negotiation, mediation, and cooperative strategies are relevant for taking decisions and/or solving problems.
Regulation of Wnt signaling by the tumor suppressor adenomatous polyposis coli does not require the ability to enter the nucleus or a particular cytoplasmic localization
Authors: Roberts David M. , Pronobis Mira I. , Poulton John S. , Kane Eric G. , Peifer Mark
Published: April 2012

Wnt signaling plays key roles in development and disease. The tumor suppressor adenomatous polyposis coli (APC) is an essential negative regulator of Wnt signaling. Its best-characterized role is as part of the destruction complex, targeting the Wnt effector β-catenin (βcat) for phosphorylation and ultimate destruction, but several studies suggested APC also may act in the nucleus at promoters of Wnt-responsive genes or to shuttle βcat out for destruction. Even in its role in the destruction complex, APC's mechanism of action remains mysterious. We have suggested APC positions the destruction complex at the appropriate subcellular location, facilitating βcat destruction. In this study, we directly tested APC's proposed roles in the nucleus or in precisely localizing the destruction complex by generating a series of APC2 variants to which we added tags relocalizing otherwise wild-type APC to different cytoplasmic locations. We tested these for function in human colon cancer cells and Drosophila embryos. Strikingly, all rescue Wnt regulation and down-regulate Wnt target genes in colon cancer cells, and most restore Wnt regulation in Drosophila embryos null for both fly APCs. These data suggest that APC2 does not have to shuttle into the nucleus or localize to a particular subcellular location to regulate Wnt signaling.
Reading Vocabulary Knowledge and Deafness
Authors: Paul Peter V.
Published: April 2012

With respect to reading vocabulary knowledge and deafness, this article addresses two broad questions: (1) Why is vocabulary knowledge related to reading comprehension ability? (2) How is reading vocabulary (i.e., word meanings) acquired? The article argues that the answers to these questions are best addressed by a vocabulary acquisition model labeled the knowledge model. In essence, this model asserts that both breadth and depth of vocabulary knowledge are critical. It is necessary to teach vocabulary, especially to poor readers, who are not likely to derive many word meanings from the use of context during natural or deliberate reading situations. On the basis of theoretical and research syntheses, the article offers implications for vocabulary instruction for deaf children and adolescents.
Temporal Order and Causal Inference
Authors: Miller Warren E.
Published: April 2012

Measures of change in pairs of attitudinal variables can provide important insights into the structure of the political belief systems of mass publics. Panel data reveal evidence of the greater centrality of some idea elements rather than others in the context of short-term dynamic constraint. Specification of the theoretically relevant voter attributes makes it possible to test for expected structural differences connecting policy related predispositions and policy preferences; specification also makes it possible to test propositions involving the reciprocal effects of attitudes and emerging vote preferences. Some of the more helpful specifications disclose the extent to which population heterogeneity produces a blurred image of relationships when analysis is based on the total electorate rather than limited to voters or subsets of voters specified by theoretical criteria.
Nonparametric Unfolding of Binary Choice Data
Authors: Poole Keith T.
Published: April 2012

This paper shows a general nonparametric unfolding technique for maximizing the correct classification of binary choice or two-category data. The motivation for and the primary focus of the unfolding technique are parliamentary roll call voting data. However, the procedures that implement the unfolding also can be applied to the problem of unfolding rank order data as well as analyzing a data set that would normally be the subject of a probit, logit, or linear probability analysis. One aspect of the scaling method greatly improves Manski's “maximum score estimator” technique for estimating limited dependent variable models. To unfold binary choice data two subproblems must be solved. First, given a set of chooser or legislator points, a cutting plane must be found such that it divides the legislators/choosers into two sets that reproduce the actual choices as closely as possible. Second, given a set of cutting planes for the binary choices, a point for each chooser or legislator must be found which reproduces the actual choices as closely as possible. Solutions for these two problems are shown in this paper. Monte Carlo tests of the procedure show it to be highly accurate in the presence of voting error and missing data.
Estimation and Inference Are Missing Data Problems: Unifying Social Science Statistics via Bayesian Simulation
Authors: Jackman Simon
Published: April 2012

Bayesian simulation is increasingly exploited in the social sciences for estimation and inference of model parameters. But an especially useful (if often overlooked) feature of Bayesian simulation is that it can be used to estimate any function of model parameters, including “auxiliary” quantities such as goodness-of-fit statistics, predicted values, and residuals. Bayesian simulation treats these quantities as if they were missing data, sampling from their implied posterior densities. Exploiting this principle also lets researchers estimate models via Bayesian simulation where maximum-likelihood estimation would be intractable. Bayesian simulation thus provides a unified solution for quantitative social science. I elaborate these ideas in a variety of contexts: these include generalized linear models for binary responses using data on bill cosponsorship recently reanalyzed in Political Analysis, item—response models for the measurement of respondent's levels of political information in public opinion surveys, the estimation and analysis of legislators' ideal points from roll-call data, and outlier-resistant regression estimates of incumbency advantage in U.S. Congressional elections
Ecological Inference and Entropy-Maximizing: An Alternative Estimation Procedure for Split-Ticket Voting
Authors: Johnston Ron , Pattie Charles
Published: April 2012

Publication of King's A Solution to the Ecological Inference Problem has rekindled interest in the estimation of unknown cell values in two- and three-dimensional matrices from knowledge of the marginal sums. This paper outlines an entropy-maximizing (EM) procedure which employs more constraints than King's EI method and produces mathematical rather than statistical procedures: the estimates are maximum-likelihood values. The mathematics are outlined, and the procedure's use illustrated with a study of ticket-splitting at New Zealand's first (1996) general election using the mixed-member proportional representation system, for which official figures provide a check against the EM estimate of the number voting a straight party ticket in each constituency.
Nuisance vs. Substance: Specifying and Estimating Time-Series-Cross-Section Models
Authors: Beck Nathaniel , Katz Jonathan N.
Published: April 2012

In a previous article we showed that ordinary least squares with panel corrected standard errors is superior to the Parks generalized least squares approach to the estimation of time-series-cross-section models. In this article we compare our proposed method with another leading technique, Kmenta's “cross-sectionally heteroskedastic and timewise autocorrelated” model. This estimator uses generalized least squares to correct for both panel heteroskedasticity and temporally correlated errors. We argue that it is best to model dynamics via a lagged dependent variable rather than via serially correlated errors. The lagged dependent variable approach makes it easier for researchers to examine dynamics and allows for natural generalizations in a manner that the serially correlated errors approach does not. We also show that the generalized least squares correction for panel heteroskedasticity is, in general, no improvement over ordinary least squares and is, in the presence of parameter heterogeneity, inferior to it. In the conclusion we present a unified method for analyzing time-series-cross-section data.
A Dynamic Model of Campaign Spending in Congressional Elections
Authors: Box-Steffensmeier Janet M. , Lin Tse-min
Published: April 2012

In contrast to conventional studies on campaign finance, which focus on the aggregate effect of money on the vote, we propose a more general dynamic model based on temporally disaggregated data. The model is supported by the substantive understanding that at different stages of the campaign process candidates have different goals, and their expenditures should have different effects on the final election outcome. Using Achen's (1986) framework of quasi experiments, the model includes dynamic “assignment equations” and “outcome equations”, which address the problem of nonrandom assignment. A final vote equation is derived in which the coefficients of period-specific incumbent expenditures are constrained by an Almon polynomial. Empirical estimation provides evidence for a three-stage dynamic campaign process.
An Empirical Spatial Model of Congressional Campaigns
Authors: McCarty Nolan M. , Poole Keith T.
Published: April 2012

Testing and estimating formal models of political behavior has not advanced as far as theoretical applications. One of the major literatures in formal theory is the spatial model of electoral competition which has its origins in the work of Black (1948) and Downs (1957). These models are used to make predictions about the policy positions candidates take in order to win elections. A lack of data on these candidate positions, especially challengers who never serve in Congress, has made direct testing of these models on congressional elections difficult.

Recently, researchers have begun to incorporate campaign finance into the standard Downsian model. These models of position-induced contributions examine the tradeoff that candidates make between choosing positions favorable to interest group contributors and positions favorable to voters. A major premise of these models is that interest group contributions are based on the policy positions of candidates. This has been borne out empirically in the case of incumbents, but not challengers.

To test key hypotheses of these models, we develop a simple spatial model of position-induced campaign contributions where the PAC's decision to contribute or abstain from each race is a function of the policy distance between the PAC and the candidates. We use data from political action committee contributions in order to estimate the locations of incumbents, challengers and PACs. Our model reliably estimates the spatial positions as well as correctly predicts nearly 74 percent of the contribution and abstention decisions of the PACs. Conditional upon making a contribution, we correctly predict the contribution in 94 percent of the cases. These results are strong evidence for position-induced campaign contributions. Furthermore, our estimates of candidate positions allow us to address issues of platform convergence between candidates.
The Structure of Mathematical Experience According to Jean Cavaillès
Authors: CORTOIS PAUL
Published: April 2012

In this expository article one of the contributions of Jean Cavailles to the philosophy of mathematics is presented: the analysis of ‘mathematical experience’. The place of Cavailles on the logico-philosophical scene of the 30s and 40s is sketched. I propose a partial interpretation of Cavailles's epistemological program of so-called ‘conceptual dialectics’: mathematical holism, duality principles, the notion of formal contents, and the specific temporal structure of conceptual dynamics. The structure of mathematical abstraction is analysed in terms of its complementary dimensions: paradigmatic generalization (domain extension, descriptive definitions, creative role of the symbolism…) and thematic reflexivity of concepts (promotion of operations to objects of a higher type).
Health Supervision in the Management of Children and Adolescents With IBD
Authors: Rufo Paul A. , Denson Lee A. , Sylvester Francisco A. , Szigethy Eva , Sathya Pushpa , Lu Ying , Wahbeh Ghassan T. , Sena Laureen M. , Faubion William A.
Published: April 2012

Ulcerative colitis (UC) and Crohn disease (CD), collectively referred to as inflammatory bowel disease (IBD), are chronic inflammatory disorders that can affect the gastrointestinal tract of children and adults. Like other autoimmune processes, the cause(s) of these disorders remain unknown but likely involves some interplay between genetic vulnerability and environmental factors. Children, in particular with UC or CD, can present to their primary care providers with similar symptoms, including abdominal pain, diarrhea, weight loss, and bloody stool. Although UC and CD are more predominant in adults, epidemiologic studies have demonstrated that a significant percentage of these patients were diagnosed during childhood. The chronic nature of the inflammatory process observed in these children and the waxing and waning nature of their clinical symptoms can be especially disruptive to their physical, social, and academic development. As such, physicians caring for children must consider these diseases when evaluating patients with compatible symptoms. Recent research efforts have made available a variety of more specific and effective pharmacologic agents and improved endoscopic and radiologic assessment tools to assist clinicians in the diagnosis and interval assessment of their patients with IBD; however, as the level of complexity of these interventions has increased, so too has the need for practitioners to become familiar with a wider array of treatments and the risks and benefits of particular diagnostic testing. Nonetheless, in most cases, and especially when frequent visits to subspecialty referral centers are not geographically feasible, primary care providers can be active participants in the management of their pediatric patients with IBD. The goal of this article is to educate and assist pediatricians and adult gastroenterology physicians caring for children with IBD, and in doing so, help to develop more collaborative care plans between primary care and subspecialty providers.
Balancing on tightropes and slacklines
Authors: Paoletti P. , Mahadevan L.
Published: April 2012

Balancing on a tightrope or a slackline is an example of a neuromechanical task where the whole body both drives and responds to the dynamics of the external environment, often on multiple timescales. Motivated by a range of neurophysiological observations, here we formulate a minimal model for this system and use optimal control theory to design a strategy for maintaining an upright position. Our analysis of the open and closed-loop dynamics shows the existence of an optimal rope sag where balancing requires minimal effort, consistent with qualitative observations and suggestive of strategies for optimizing balancing performance while standing and walking. Our consideration of the effects of nonlinearities, potential parameter coupling and delays on the overall performance shows that although these factors change the results quantitatively, the existence of an optimal strategy persists.
Real time forecasting of near-future evolution
Authors: Gerrish Philip J. , Sniegowski Paul D.
Published: April 2012

A metaphor for adaptation that informs much evolutionary thinking today is that of mountain climbing, where horizontal displacement represents change in genotype, and vertical displacement represents change in fitness. If it were known
a priori
what the ‘fitness landscape’ looked like, that is, how the myriad possible genotypes mapped onto fitness, then the possible paths up the fitness mountain could each be assigned a probability, thus providing a dynamical theory with long-term predictive power. Such detailed genotype–fitness data, however, are rarely available and are subject to change with each change in the organism or in the environment. Here, we take a very different approach that depends only on fitness or phenotype–fitness data obtained in real time and requires no
a priori
information about the fitness landscape. Our general statistical model of adaptive evolution builds on classical theory and gives reasonable predictions of fitness and phenotype evolution many generations into the future.
Elaboration, characterization and properties of silica-based single-site heterogeneous photocatalysts
Authors: Che Michel , Mori Kohsuke , Yamashita Hiromi
Published: April 2012

This study concerns single-site heterogeneous photocatalysts, composed of isolated transition metals ions (single-sites) dispersed on silica-based supports, which can be used as photocatalysts. The first part gives the definition of single-site heterogeneous catalysts. The main difficulty to prepare the latter resides in the speciation of the key elements (metal of the catalytically active phase and oxygen of the solid support) and other species (notably counter ions and ligands) the presence of which depends on the synthesis method adopted. The best preparation methods as well as the ideal features of single-site heterogeneous photocatalysts are discussed before the study focuses on single-site heterogeneous photocatalysts. Case studies are presented with photocatalysts involving titanium and chromium, and their photocatalytic reactions such as CO2reduction with H2O, degradation of organic pollutants diluted in water, NO decomposition and selective oxidation of propane are also described.
The small genome segment of Bunyamwera orthobunyavirus harbours a single transcription-termination signal
Authors: Blakqori Gjon , Lowen Anice C. , Elliott Richard M.
Published: April 2012

Transcription termination of the mRNA produced from the small (S) genome segment of Bunyamwera orthobunyavirus (BUNV) has previously been mapped to two cis-acting sequences located within the 5′ UTR using a virus-free replication assay. The ability of these sequences to terminate transcription was attributed to the shared pentanucleotide motif 3′-UGUCG-5′. Taking advantage of our plasmid-based rescue system to generate recombinant viruses, we re-evaluated the importance of both pentanucleotide motifs as well as that of two other conserved sequences in transcription termination in vivo. Analysis of the 3′ ends of positive-stranded viral RNAs derived from the S segment revealed that only the region around the upstream pentanucleotide motif mediated transcription termination in cells infected with wild-type BUNV, leading to mRNAs that were about 100 nt shorter than antigenome RNA. Furthermore, the downstream motif was not recognized in recombinant viruses in which the upstream signal has been disrupted. Our results suggest that in the context of virus infection transcription termination of the BUNV S genome segment mRNA is exclusively directed by the upstream-termination signal. Interestingly, within this region we identified a motif similar to a transcription-termination sequence used by Rift Valley fever phlebovirus.
Identification and Characterization of Differentially Expressed Transcripts in the Gills of Freshwater Prawn (Macrobrachium rosenbergii) under Salt Stress
Authors: Barman Hirak Kumar , Patra Swagat Kumar , Das Varsha , Mohapatra Shibani Dutta , Jayasankar Pallipuram , Mohapatra Chinmayee , Mohanta Ramya , Panda Rudra Prasanna , Rath Surya Narayan
Published: April 2012

The giant freshwater prawn,Macrobrachium rosenbergii,is an economically important species. It is a euryhaline shrimp, surviving in wide-range salinity conditions. A change in gene expression has been suggested as an important component for stress management. To better understand the osmoregulatory mechanisms mediated by the gill, a subtractive and suppressive hybridization (SSH) tool was used to identify expressed transcripts linked to adaptations in saline water. A total of 117 transcripts represented potentially expressed under salinity conditions. BLAST analysis identified 22% as known genes, 9% as uncharacterized showing homologous to unannotated ESTs, and 69% as unknown sequences. All the identified known genes representing broad spectrum of biological pathways were particularly linked to stress tolerance including salinity tolerance. Expression analysis of 10 known genes and 7 unknown/uncharacterized genes suggested their upregulation in the gills of prawn exposed to saline water as compared to control indicating that these are likely to be associated with salinity acclimation. Rapid amplification of cDNA ends (RACE) was used for obtaining full-length cDNA of MRSW-40 clone that was highly upregulated during salt exposure. The sequenced ESTs presented here will have potential implications for future understanding about salinity acclimation and/or tolerance of the prawn.
Satisfaction with Access to Health Services: The Perspective of Estonian Patients with Rheumatoid Arthritis
Authors: Põlluste Kaja , Kallikorm Riina , Meiesaar Kersti , Lember Margus
Published: April 2012

In this cross-sectional study we explained the possible determinants of satisfaction with access to health services in patients with rheumatoid arthritis (RA). Of the 2000 randomly selected Estonian adult patients with RA, a total 1259 completed the survey. Regression analysis was used to analyse the predictors of patients' satisfaction with access to health services. Half of the respondents were satisfied with their access to health services. Factors that had a negative impact on satisfaction included pain intensity, longer waiting times to see the doctors, as well as low satisfaction with the doctors. Transportation costs to visit a rheumatologist and higher rehabilitation expenses also affected the degree of satisfaction. Patients who could choose the date and time at which they could visit the rheumatologist or who could visit their “own” doctor were more likely to be satisfied than patients whose appointment times were appointed by a healthcare provider.
Development and Evaluation of a Positive Youth Development Course for University Students in Hong Kong
Authors: Shek Daniel T. L. , Sun Rachel C. F. , Chui Y. H. , Lit S. W. , Yuen Walter W. , Chung Yida Y. H. , Ngai S. W.
Published: April 2012

With higher education, university graduates are important elements of the labor force in knowledge-based economies. With reference to the mental health and developmental problems in university students, there is a need to review university’s role in nurturing holistic development of students. Based on the positive youth development approach, it is argued that promoting intrapersonal competencies is an important strategy to facilitate holistic development of young people in Hong Kong. In The Hong Kong Polytechnic University, a course entitled Tomorrow’s Leader focusing on positive youth development constructs to promote student well-being will be offered on a compulsory basis starting from 2012/13 academic year under the new undergraduate curriculum structure. The proposed course was piloted in 2010/11 school year. Different evaluation strategies, including objective outcome evaluation, subjective outcome evaluation, process evaluation, and qualitative evaluation, are being carried out to evaluate the developed course. Preliminary evaluation findings based on the piloting experience in 2010/11 academic year are presented in this paper.
Optimization of Sunflower Oil Transesterification Process Using Sodium Methoxide
Authors: KoohiKamali Sara , Tan Chin Ping , Ling Tau Chuan
Published: April 2012

In this study, the methanolysis process of sunflower oil was investigated to get high methyl esters (biodiesel) content using sodium methoxide. To reach to the best process conditions, central composite design (CCD) through response surface methodology (RSM) was employed. The optimal conditions predicted were the reaction time of 60 min, an excess stoichiometric amount of alcohol to oil ratio of 25%w/w and the catalyst content of 0.5%w/w, which lead to the highest methyl ester content (100%w/w). The methyl ester content of the mixture from gas chromatography analysis (GC) was compared to that of optimum point. Results, confirmed that there was no significant difference between the fatty acid methyl ester content of sunflower oil produced under the optimized condition and the experimental value (P≥0.05). Furthermore, some fuel specifications of the resultant biodiesel were tested according to American standards for testing of materials (ASTM) methods. The outcome showed that the methyl ester mixture produced from the optimized condition met nearly most of the important biodiesel specifications recommended in ASTM D 6751 requirements. Thus, the sunflower oil methyl esters resulted from this study could be a suitable alternative for petrol diesels.
A Comparison of the Physicochemical Properties and Fatty Acid Composition of Indaiá (Attalea dubia) and Babassu (Orbignya phalerata) Oils
Authors: Silva Ferreira Bianca , Pereira Faza Lara , Le Hyaric Mireille
Published: April 2012

The physicochemical properties and fatty acid composition ofAttalea dubia (Mart.)Burret (indaiá) seed oil were investigated. The oil was extracted in a soxhlet apparatus using petroleum ether and evaluated for iodine, acid, peroxide, ester, and saponification values. The oil was also analyzed using infrared and nuclear magnetic resonance spectroscopy. The fatty acid profile of the oil was determined by GC-MS. For each analysis indaiá oil was compared toOrbignya phalerata(babassu) oil. The two oils appeared to be very similar in their fatty acid composition, in which lauric acid (the most abundant), myristic acid, caprylic acid, and capric acid were the four main fatty acids detected. The unsaturated fatty acids content was lower for indaiá oil (5.8%) than for babassu oil (9.4%). The results suggest that indaiá palm tree could be cultivated as a new source of vegetable oil with potential for food and cosmetic industries.
Optimization of Acid Protease Production byAspergillus nigerI1 on Shrimp Peptone Using Statistical Experimental Design
Authors: Siala Rayda , Frikha Fakher , Mhamdi Samiha , Nasri Moncef , Sellami Kamoun Alya
Published: April 2012

Medium composition and culture conditions for the acid protease production byAspergillus nigerI1 were optimized by response surface methodology (RSM). A significant influence of temperature, KH2PO4, and initial pH on the protease production was evaluated by Plackett-Burman design (PBD). These factors were further optimized using Box-Behnken design and RSM. Under the proposed optimized conditions, the experimental protease production (183.13 U mL−1) closely matched the yield predicted by the statistical model (172.57 U mL−1) withR2=0.914. Compared with the initial M1 medium on which protease production was 43.13 U mL−1, a successful and significant improvement by 4.25 folds was achieved in the optimized medium containing (g/L): hulled grain of wheat (HGW) 5.0; KH2PO41.0; NaCl 0.3; MgSO4(7H2O) 0.5; CaCl2(7H2O) 0.4; ZnSO40.1; Na2HPO41.6; shrimp peptone (SP) 1.0. The pH was adjusted at 5 and the temperature at30°C. More interestingly, the optimization was accomplished using two cheap and local fermentation substrates, HGW and SP, which may result in a significant reduction in the cost of medium constituents.
Effects of Linear-Polarized Near-Infrared Light Irradiation on Chronic Pain
Authors: Huang Dong , Gu Yong-Hong , Liao Qin , Yan Xue-Bin , Zhu Shai-Hong , Gao Chang-Qing
Published: April 2012

In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR) on relieving chronic pain in conjunction with nerve block (NB) or local block (LB), a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs) were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score) decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P<0.05), while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.
A New Record for Occurrence ofSymphodus bailloni(Osteichthyes: Perciformes: Labridae) in the Western Black Sea Coast of Turkey
Authors: Göktürk Didem , Karakulak F. Saadet , Ünsal Nuran , Kahraman Abdullah E.
Published: April 2012

The fish speciesSymphodus bailloni(Valenciennes, 1839) reported in the present study were collected between June 2010 and June 2011 from the western Black Sea coasts which were previously not recorded from the Black Sea coast of Turkey. A total of 717 specimens ofS. bailloniwere measured, ranging between 8.9 and 15.4 cm TL. Morphometrics, meristics, and diagnostic characteristics of the species are presented.
Impact of Long-Term Forest Enrichment Planting on the Biological Status of Soil in a Deforested Dipterocarp Forest in Perak, Malaysia
Authors: Karam D. S. , Arifin A. , Radziah O. , Shamshuddin J. , Majid N. M. , Hazandy A. H. , Zahari I. , Nor Halizah A. H. , Rui T. X.
Published: April 2012

Deforestation leads to the deterioration of soil fertility which occurs rapidly under tropical climates. Forest rehabilitation is one of the approaches to restore soil fertility and increase the productivity of degraded areas. The objective of this study was to evaluate and compare soil biological properties under enrichment planting and secondary forests at Tapah Hill Forest Reserve, Perak after 42 years of planting. Both areas were excessively logged in the 1950s and left idle without any appropriate forest management until 1968 when rehabilitation program was initiated. Six subplots (20 m × 20 m) were established within each enrichment planting (F1) and secondary forest (F2) plots, after which soil was sampled at depths of 0–15 cm (topsoil) and 15–30 cm (subsoil). Results showed that total mean microbial enzymatic activity, as well as biomass C and N content, was significantly higher in F1 compared to F2. The results, despite sample variability, suggest that the rehabilitation program improves the soil biological activities where high rate of soil organic matter, organic C, N, suitable soil acidity range, and abundance of forest litter is believed to be the predisposing factor promoting higher population of microbial in F1 as compared to F2. In conclusion total microbial enzymatic activity, biomass C and biomass N evaluation were higher in enrichment planting plot compared to secondary forest. After 42 years of planting, rehabilitation or enrichment planting helps to restore the productivity of planted forest in terms of biological parameters.
Analysis of Risk Factors for Amputation in 822 Cases with Acute Arterial Emboli
Authors: Dag Ozgur , Kaygın Mehmet Ali , Erkut Bilgehan
Published: April 2012

Background. We retrospectively examined the records of 822 patients who underwent a total of 901 operations for acute peripheral arterial occlusion of the upper or lower extremities between 1999 and 2009. We analyzed the effects of atherosclerotic structure, the time of admission to hospital, and re-embolectomies on amputation in the early postoperative period.Methods. There were 466 (56.7%) men and 356 (43.3%) women. The time of admission to hospital was in the range of 58 hours. There were lower extremity emboli in 683 (83%). Bypass procedures were done in 27 (3.3%) patients. Fasciotomy, patchplasty, and endarterectomy were made in 19 (2.3%), 9 (1.1%), and 7 (0.8%) patients, respectively.Results. Early revision (re-embolectomy) was performed in 77 (9.3%) patients. Amputation was performed in 112 (13.6%) patients. Delay after six hours from the onset of complaints and re-embolectomies increased the risk of amputation and rates.Conclusion. If the embolectomy, which is a rapid and easy technique for treatment of acute arterial emboli, is performed by experienced surgeons without delay, the complications associated with the emboli may be prevented. Otherwise, delayed operation and repeated re-embolizations in acute arterial play important roles in morbidity.
Microbiological Hazard Identification and Exposure Assessment of Poultry Products Sold in Various Localities of Hyderabad, India
Authors: Sudershan Rao V. , Naveen Kumar R. , Kashinath L. , Bhaskar V. , Polasa K.
Published: April 2012

A study was carried out to identify microbiological hazards and assess their exposure associated with consumption of poultry based street food served in different localities of Hyderabad. The study indicated that chicken 65, chicken fried rice, chicken noodles, chicken Manchuria and chilly chicken are the most common recipes. A process flow diagram was developed to identify critical control points in the food item. After analysis of the samples at each level of preparation, it was observed that rice and noodles were kept at room temperature for about 5-6 hrs which was a critical control point. A total of 376 samples including chicken fried rice, chicken noodles, boiled noodles and boiled rice were collected from circle 1, 2, 3, 4, 5, 6, and 7 of Greater Hyderabad municipal corporation (GHMC) and analyzed for microbiological examination. The most prevalent pathogenic bacteria isolated wereS. aureus(3.4 log 10 cfu/g) andB. cereus(3.4 log 10 cfu/g).Salmonellaspp. was present in salads (3.2 log 10 cfu/g) and hand washings of the food handler (3.5 log 10 cfu/g).Salmonellacontamination was found in salads served along with chicken fried rice and chicken noodles than in the food.