bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental response to a seasonal time constraint: the effects of photoperiod on reproduction in the grasshopperRomalea microptera
Authors: HOMENY RACHEL H. , JULIANO STEVEN A.
Published: September 2007

Abstract1. Some organisms respond adaptively to seasonal time constraints by altering development time to life‐history transitions (e.g. metamorphosis, oviposition). Such life‐history changes may have costs (e.g. reduced fecundity, mass, offspring quality).

2. The hypothesis that a northern population of the grasshopperRomalea microptera(Beauvois) would show adaptive plasticity in oviposition timing in response to seasonal time constraints was tested by manipulating photoperiod to simulate the middle of the active season (Long photoperiod), the end of the active season (Short photoperiod), and seasonal change (photoperiod Declining from long to short). Females received either high or low food rations. Short or Declining photoperiod were predicted to induce early oviposition with costs of reduced egg number, post‐oviposition mass, or egg size, particularly in low‐food females.

3. Effects of food ration and photoperiod, but not interaction, were significant in failure time analysis of age at oviposition.mancovaon age at oviposition, egg number, and post‐oviposition mass yielded similar effects. The multivariate effect of photoperiod resulted primarily from reduced time to oviposition in Short or Declining photoperiod. No costs in egg number or post‐oviposition mass were associated with this photoperiod‐induced reduction in time to oviposition. The multivariate effect of food ration resulted mainly from lower egg number with low food. Food ration affected egg size, but photoperiod and interaction did not. In all cases, Short and Declining photoperiod produced similar effects.

4. In its northern range,R. micropteraaccelerates reproduction in response to seasonal constraints, a response that may be adaptive. HowR. micropteraavoids costs associated with this reduced pre‐oviposition period remains unknown.
HMGA1a: sequence‐specific RNA‐binding factor causing sporadic Alzheimer's disease‐linked exon skipping of presenilin‐2 pre‐mRNA
Authors: Manabe Takayuki , Ohe Kenji , Katayama Taiichi , Matsuzaki Shinsuke , Yanagita Takeshi , Okuda Hiroaki , Bando Yoshio , Imaizumi Kazunori , Reeves Raymond , Tohyama Masaya , Mayeda Akila
Published: September 2007

Aberrant exon 5 skipping of presenilin‐2 (PS2) pre‐mRNA produces a deleterious protein isoform PS2V, which is almost exclusively observed in the brains of sporadic Alzheimer's disease patients. PS2V over‐expression in vivo enhances susceptibility to various endoplasmic reticulum (ER) stresses and increases production of amyloid‐β peptides. We previously purified and identified high mobility group A protein 1a (HMGA1a) as a trans‐acting factor responsible for aberrant exon 5 skipping. Using heterologous pre‐mRNAs, here we demonstrate that a specific HMGA1a‐binding sequence in exon 5 adjacent to the 5′ splice site is necessary for HMGA1a to inactivate the 5′ splice site. An aberrant HMGA1a–U1 snRNP complex was detected on the HMGA1a‐binding site adjacent to the 5′ splice site during the early splicing reaction. A competitor 2′‐O‐methyl RNA (2′‐O‐Me RNA) consisting of the HMGA1a‐binding sequence markedly repressed exon 5 skipping of PS2 pre‐mRNA in vitro and in vivo. Finally, HMGA1a‐induced cell death under ER stress was prevented by transfection of the competitor 2′‐O‐Me RNA. These results provide insights into the molecular basis for PS2V‐associated neurodegenerative diseases that are initiated by specific RNA binding of HMGA1a.
Housekeeping sortase facilitates the cell wall anchoring of pilus polymers in Corynebacterium diphtheriae
Authors: Swaminathan Anu , Mandlik Anjali , Swierczynski Arlene , Gaspar Andrew , Das Asis , Ton‐That Hung
Published: September 2007

Many surface proteins in Gram‐positive bacteria are covalently linked to the cell wall through a transpeptidation reaction catalysed by the enzyme sortase. Corynebacterium diphtheriae encodes six sortases, five of which are devoted to the assembly of three distinct types of pilus fibres – SrtA for the SpaA‐type pilus, SrtB/SrtC for the SpaD‐type pilus, and SrtD/SrtE for the SpaH‐type pilus. We demonstrate here the function of SrtF, the so‐called housekeeping sortase, in the cell wall anchoring of pili. We show that a multiple deletion mutant strain expressing only SrtA secretes a large portion of SpaA polymers into the culture medium, with concomitant decrease in the cell wall‐linked pili. The same phenotype is observed with the mutant that is missing SrtF alone. By contrast, a strain that expresses only SrtF displays surface‐linked pilins but no polymers. Therefore, SrtF can catalyse the cell wall anchoring of pilin monomers as well as pili, but it does not polymerize pilins. We show that SrtA and SrtF together generate wild‐type levels of the SpaA‐type pilus on the bacterial surface. Furthermore, by regulating the expression of SpaA in the cell, we demonstrate that the SrtF function becomes critical when the SpaA level is sufficiently high. Together, these findings provide key evidence for a two‐stage model of pilus assembly: pilins are first polymerized by a pilus‐specific sortase, and the resulting fibre is then attached to the cell wall by either the cognate sortase or the housekeeping sortase.
Sympathetic (electrodermal) activity during repeated maximal rectal distensions in patients with irritable bowel syndrome and constipation
Authors: Walter S. , Bodemar G. , Hallböök O. , Thorell L.‐h.
Published: September 2007

Abstract  Irritable bowel syndrome (IBS) is associated with visceral hypersensitivity, stress and autonomic dysfunction. Sympathetic activity during repeated events indicates excitatory or inhibitory mechanisms such as sensitization or habituation. We investigated skin conductance (SC) during repetitive rectal distensions at maximal tolerable pressure in patients with IBS and chronic constipation. Twenty‐seven IBS patients, 13 constipation patients and 18 controls underwent two sets of isobaric rectal distensions. First, maximal tolerable distension was determined and then it was repeated five times. Skin conductance was measured continuously. Subjective symptom assessment remained steady in all groups. The baseline values of SC were higher in IBS patients than in patients with constipation and significantly lower in constipation patients than in controls. The maximal SC response to repetitive maximal distensions was higher in IBS patients compared with constipation patients. The amplitude of the initial SC response decreased successively with increased number of distensions in patients with IBS and constipation but not in controls. Irritable bowel syndrome and constipation patients habituated to maximal repetitive rectal distensions with decreasing sympathetic activity. Irritable bowel syndrome patients had higher sympathetic reactivity and baseline activity than constipation patients. A lower basal SC in constipation patients compared with controls suggests an inhibition of the sympathetic drive in constipation patients.
The effect of drought and heat stress on reproductive processes in cereals
Authors: BARNABÁS BEÁTA , JÄGER KATALIN , FEHÉR ATTILA
Published: September 2007

As the result of intensive research and breeding efforts over the last 20 years, the yield potential and yield quality of cereals have been greatly improved. Nowadays, yield safety has gained more importance because of the forecasted climatic changes. Drought and high temperature are especially considered as key stress factors with high potential impact on crop yield. Yield safety can only be improved if future breeding attempts will be based on the valuable new knowledge acquired on the processes determining plant development and its responses to stress. Plant stress responses are very complex. Interactions between plant structure, function and the environment need to be investigated at various phases of plant development at the organismal, cellular as well as molecular levels in order to obtain a full picture. The results achieved so far in this field indicate that various plant organs, in a definite hierarchy and in interaction with each other, are involved in determining crop yield under stress. Here we attempt to summarize the currently available information on cereal reproduction under drought and heat stress and to give an outlook towards potential strategies to improve yield safety in cereals.
A test of the optimality approach to modelling canopy properties and CO2 uptake by natural vegetation
Authors: SCHYMANSKI STANISLAUS J. , RODERICK MICHAEL L. , SIVAPALAN MURUGESU , HUTLEY LINDSAY B. , BERINGER JASON
Published: September 2007

Photosynthesis provides plants with their main building material, carbohydrates, and with the energy necessary to thrive and prosper in their environment. We expect, therefore, that natural vegetation would evolve optimally to maximize its net carbon profit (NCP), the difference between carbon acquired by photosynthesis and carbon spent on maintenance of the organs involved in its uptake.

We modelled NCP for an optimal vegetation for a site in the wet‐dry tropics of north Australia based on this hypothesis and on an ecophysiological gas exchange and photosynthesis model, and compared the modelled CO2 fluxes and canopy properties with observations from the site. The comparison gives insights into theoretical and real controls on gas exchange and canopy structure, and supports the optimality approach for the modelling of gas exchange of natural vegetation.

The main advantage of the optimality approach we adopt is that no assumptions about the particular vegetation of a site are required, making it a very powerful tool for predicting vegetation response to long‐term climate or land use change.
Banksia species (Proteaceae) from severely phosphorus‐impoverished soils exhibit extreme efficiency in the use and re‐mobilization of phosphorus
Authors: DENTON MATTHEW D. , VENEKLAAS ERIK J. , FREIMOSER FLORIAN M. , LAMBERS HANS
Published: September 2007

Banksia species (Proteaceae) occur on some of the most phosphorus (P)‐impoverished soils in the world. We hypothesized that Banksia spp. maximize P‐use efficiency through high photosynthetic P‐use efficiency, long leaf lifespan (P residence time), effective P re‐mobilization from senescing leaves, and maximizing seed P concentration. Field and glasshouse experiments were conducted to quantify P‐use efficiency in nine Banksia species. Leaf P concentrations for all species were extremely low (0.14–0.32 mg P g−1 DM) compared with leaf P in other species reported and low relative to other plant nutrients in Banksia spp.; however, moderately high rates of photosynthesis (13.8–21.7 µmol CO2 m−2 s−1), were measured. Some of the Banksia spp. had greater P proficiency (i.e. final P concentration in senesced leaves after re‐mobilization; range: 27–196 µg P g−1 DM) than values reported for any other species in the literature. Seeds exhibited significantly higher P concentrations (6.6–12.2 mg P g−1 DM) than leaves, and species that sprout after fire (‘re‐sprouters’) had significantly greater seed mass and P content than species that are killed by fire and regenerate from seed (‘seeders’). Seeds contained only small amounts of polyphosphate (between 1.3 and 6 µg g−1 DM), and this was not correlated with P concentration or fire response. Based on the evidence in the present study, we conclude that Banksia species are highly efficient in their use of P, explaining, in part, their success on P‐impoverished soils, with little variation between species.
Revisiting Aggregate U.S. Meat Demand with a Bayesian Averaging of Classical Estimates Approach: Do We Need a More General Theory?
Authors: Bryant Henry L. , Davis George C.
Published: September 2007

Although meat demand is one of the most studied issues in agricultural economics, our understanding of this phenomenon has been hampered by valid concerns about model specification uncertainty. This article revisits the need for more general theories of aggregate U.S. meat demand. Using a Bayesian averaging of classical estimates approach, we draw comprehensive inferences over 1,048,576 demand systems. We find very little evidence supporting the need for more general theories that include demand determinants beyond prices and expenditures. We find strong evidence in support of symmetry and negativity, but strong evidence against homogeneity, which is consistent with other research.
Welfare Effects of Technological Convergence in Processed Food Industries
Authors: Ruan Jun , Gopinath Munisamy , Buccola Steven
Published: September 2007

We develop a monopolistic competition model to investigate effects of international technological convergence on factor rewards, output composition, and welfare. Comparative static analysis indicates technological convergence improves the follower's—but impairs the leader's—international competitiveness. The leader's welfare improves unambiguously; the follower's welfare depends on the relative strength of convergence's income and terms‐of‐trade effects. We use data from seventeen food industries in thirty countries, 1993–2001, to test these analytical predictions. Evidence of convergence is found in thirteen of seventeen industries. Convergence lifts followers' relative wages and global value‐added shares. Followers benefit from convergence's positive income effect. Leaders benefit from higher terms of trade.
THE ASSOCIATION BETWEEN URBAN SPRAWL AND OBESITY: IS IT A TWO‐WAY STREET?
Authors: Plantinga Andrew J. , Bernell Stephanie
Published: September 2007

ABSTRACT We empirically examine the relationship between obesity and urban development patterns where individuals reside. Previous analyses treat urban form as exogenous to weight, and find higher body mass indices (BMI) among residents of areas with sprawl patterns of development. Using samples of recent movers, we find that the causality runs in both directions. Individuals who move to denser locations lose weight. As well, BMI is a determinant of the choice of a dense or sprawling location. In sum, while moving to a dense area results in weight loss, such locations are unlikely to be selected by individuals with high BMI.
OLIGOPOLISTIC COMPETITION AND ECONOMIC GEOGRAPHY*
Authors: Zhou Haiwen
Published: September 2007

ABSTRACTThis paper studies a general equilibrium model of economic geography in which firms engage in oligopolistic competition. This framework is conducive to analytic results. With increasing returns, oligopolistic competition leads to interindustry trade between regions rather than intraindustry trade. The choice of appropriate technology is a channel of concentration of industries.
THE IMPACT OF SPECIFIC‐SECTOR CHANGES IN EMPLOYMENT ON ECONOMIC GROWTH, LABOR MARKET PERFORMANCE AND MIGRATION
Authors: Cutler Harvey , Davies Stephen
Published: September 2007

ABSTRACT It is common in empirical regional economics to use total employment as an explanatory variable while investigating issues such as the level and distribution of income and migration. This paper argues that sector‐specific changes in employment and labor market performance can have different effects on economic growth, the collection of tax revenue, migration, and the level and distribution of household income. As such, it is important to model sectors separately. We find that expansions in employment opportunities for a high‐wage sector such as computer manufacturing or bioengineering, a medium‐wage sector manufacturing, and the lower‐wage sector of retailing have differing economic consequences for a small city. We use a data intensive computable general equilibrium model to obtain these results.
3. THE QUESTION OF HISTORY IN PRECOLONIAL INDIA
Authors: MANTENA RAMA
Published: September 2007

This essay considers an important and enduring problem in the writing of Indian history: how do we historians approach precolonial narratives of the past? A rich and suggestive new study of South Indian modes of historiography, Textures of Time: Writing History in South India 1600–1800, by Velcheru Narayana Rao, David Shulman, and Sanjay Subrahmanyam, has positioned itself at the center of this debate. For a variety of reasons, precolonial narratives have been demoted to the status of mere information, and genres of South Indian writing have been dismissed as showing that South Indians lacked the ability to write history and indeed lacked historical consciousness. Textures of Time responds to this picture by proposing a novel historical method for locating historical sensibility in precolonial narratives of the past. The authors ask us not to judge all textual traditions in India, especially narratives of the past, on the basis of the verifiability of facts contained in them. Rather they suggest a radical openness of the text, and they argue that a historical narrative is constituted in the act of reading itself. They do this by examining the role of genre and what they call texture in precolonial South Indian writing.

This essay examines the strengths and limitations of their proposal. It does so by examining the formation of colonial archives starting in the late‐eighteenth century in order to understand the predicament of history in South Asia. Colonial archives brought about a crisis in historiographical practices in India; they not only transformed texts into raw information for the historian to then reconstruct a historical narrative, they also delegitimized precolonial modes of historiography. A better understanding of these archives puts one in a better position to assess the insights of Textures of Time, but it also helps to highlight the problems in its solution. In particular, it reveals how the book continues to use modern criteria to assess premodern works, and in this way perhaps to judge them inappropriately.
4. A PRAGMATIC RESPONSE1
Authors: RAO VELCHERU NARAYANA , SHULMAN DAVID , SUBRAHMANYAM SANJAY
Published: September 2007

In the years since its twin publication in 2001 (Indian edition) and 2003 (U.S. edition), Textures of Time has attracted a great deal more attention outside the United States than in the American academy. This, we suggest, is because its ideas and approach are rather at odds with the dominant trends in the area of “postcolonial studies.” In this response to three critical essays that engage with the book—by Rama Mantena, Sheldon Pollock, and Christopher Chekuri—we begin by setting out our principal hypotheses as well as the evidentiary structure of the book, which draws mostly on vernacular materials from South India in the seventeenth and eighteenth centuries. The former includes the claim that South India between roughly 1600 and 1800 (and thus in the centuries before the consolidation of colonial rule) possessed considerable and diverse historiographical traditions, though these histories came couched in a variety of genres, rendering them difficult for the uninitiated to recognize at first; the latter requires us to develop the significance of the concepts of “texture” as well as of “subgeneric markers” that help distinguish texts with a historical intention from those that are nonhistorical but have the same generic location. Our response then goes on to discuss why theoretical or śāstric texts in India do not themselves explicitly theorize the distinctions we make. Here, we posit a contrast between “embedded” and “explicated” concepts in the “emic” sphere, suggesting that “texture” belongs to the first category. We explicitly distinguish our views from the poststructuralist (and Barthesian) language adopted by Pollock in his critique of Textures, and the more predictable postcolonial vision of Chekuri. We once more emphasize the need to take the vernacular historiography seriously, and to refine our reading practices, rather than overly depending on normative materials in Sanskrit, or on a prefabricated theoretical schema that derives from a stylized (and impoverished) view of the nature of the transformations produced by colonial rule.
Disruption of excitatory amino acid transporters in brains of SIV‐infected rhesus macaques is associated with microglia activation
Authors: Meisner Falko , Neuen‐Jacob Eva , Sopper Sieghart , Schmidt Michaela , Schlammes Serge , Scheller Carsten , Vosswinkel Daniel , Meulen Volker ter , Riederer Peter , Koutsilieri Eleni
Published: September 2007

Glutamate‐mediated neurodysfunction in human immunodeficiency virus (HIV) infection has been primarily suggested byin vitrostudies. The regulation of glutamatergic neurotransmission in inflammation is a complex interaction between activation of immune mediators and adaptive changes in the functional elements of the glutamatergic synapse. We have used simian immunodeficiency virus (SIV)‐infected macaques to answer the questions (i) whether perturbation of glutamate neurotransmission is evident during progression of immunodeficiency disease and (ii) what are the mechanisms underlying this impairment. Disease progression in SIV‐infected macaques both in the periphery and in the brain was documented by clinical and general pathological examination, plasma and brain viral RNA load, T‐cell analysis and brain histopathology. We report for the first time, disruption of excitatory amino acid transporters (EAATs), the cardinal glutamate clearing system, during SIV infection and a dramatic loss of EAATs associated with development of rapid acquired immunodeficiency syndrome (AIDS). EAATs impairment was correlated with activation status of microglia. Our data support the glutamate hypothesis for the development of HIV dementia and suggest that the pathogenetic mechanism for the neurodysfunction is the impairment of glutamate clearing which occurs in the stage of AIDS and which is associated with activated microglia.
Interactions between loop 5 and β‐strand β6′ are involved in α7 nicotinic acetylcholine receptors channel gating
Authors: Criado Manuel , Mulet José , Castillo Mar , Aldea Marcos , Sala Salvador , Sala Francisco
Published: September 2007

Binding of agonists to nicotinic acetylcholine receptors (nAChR) is coupled to channel opening through local rearrangements of different domains of the protein. Recent structural data suggest that two of these regions could be the loop 5 (L5) and the β‐strand β6′, both forming the inner part of the N‐terminal domain. Amino acids in these domains were mutated in α7 nAChRs, and expression levels and functional responses of mutant receptors were measured. Mutations located at the putative apex of L5, Asp97 and Glu98, and also at Phe100, gave receptors with smaller currents, showing qualitative differences with respect to muscle nAChRs. In contrast, mutations in the β‐strand β6′ (at Phe124 and Lys125) showed increased functional responses. Mutations affected equally the responses to acetylcholine and dimethylphenylpiperazinium, except in Phe100 where the latter was sevenfold less effective than in wild‐type. Currents in mutants decayed with almost the same kinetics, ruling out large effects on desensitization. Analysis of double mutants demonstrated a functional coupling among the three electrically charged amino acids Asp97, Glu98, and Lys125, and also between Phe100 and Phe124. The results are compatible with the involvement of functional interactions between L5 and β‐strand β6′ during nAChR activation.
The α4β2α5 nicotinic cholinergic receptor in rat brain is resistant to up‐regulation by nicotinein vivo
Authors: Mao Danyan , Perry David C. , Yasuda Robert P. , Wolfe Barry B. , Kellar Kenneth J.
Published: September 2007

We used immunoprecipitation with subunit‐specific antibodies to examine the distribution of heteromeric neuronal nicotinic acetylcholine receptors (nAChRs) that contain the α5 subunit in the adult rat brain. Among the regions of brain we surveyed, the α5 subunit is associated in ∼37% of the nAChRs in the hippocampus, ∼24% of the nAChRs in striatum, and 11–16% of the receptors in the cerebral cortex, thalamus, and superior colliculus. Sequential immunoprecipitation assays demonstrate that the α5 subunit is associated with α4β2* nAChRs exclusively. Importantly, in contrast to α4β2 nAChRs, which are increased by 37–85% after chronic administration of nicotine, the α4β2α5 receptors are not increased by nicotine treatment. These data thus indicate that the α4β2α5 nAChRs in rat brain are resistant to up‐regulation by nicotinein vivo, which suggests an important regulatory role for the α5 subunit. To the extent that nicotine‐induced up‐regulation of α4β2 nAChRs is involved in nicotine addiction, the resistance of the α4β2α5 subtype to up‐regulation may have important implications for nicotine addiction.
Cyclic electrographic seizures in critically ill patients
Authors: Friedman David E. , Schevon Catherine , Emerson Ronald G. , Hirsch Lawrence J.
Published: September 2007

Summary

Purpose: Prolonged electroencephalographic monitoring has facilitated the detection of nonconvulsive seizures. Compressed displays of EEG frequency spectra (such as compressed spectral array, CSA) can facilitate interpretation of continuous EEG by allowing the reader to observe on a single screen patterns evolving over many minutes or hours.

Methods: Patients were identified retrospectively over a 4‐year period as displaying a cycling pattern of seizures on CSA.

Results: We describe a pattern of seizures recurring in a cyclic fashion in a series of 13 critically ill patients of all ages. Several patients had a gradual buildup of EEG power prior to each seizure.

Conclusion: We believe that while not rare, this pattern is difficult to recognize on standard EEG recording but it is readily apparent on CSA. The underlying pathophysiology of cyclic seizures is not known, but we speculate that cyclic seizures represent a form of status epilepticus in which the usual seizure terminating factors are present and transiently effective, but are inadequate to prevent resumption of the seizure activity. Studying these patients may provide insight into the pathophysiology of seizure initiation and cessation.
Flow cytometric determination of residual white blood cell levels in preserved samples from leukoreduced blood products
Authors: Palmer Douglas S. , Birch Paul , O'Toole Joan , Henderson Deborah , Scalia Vito
Published: September 2007

BACKGROUND: In preparation for a proposed consolidated testing service, Canadian Blood Services undertook the evaluation of a commercial test kit for the enumeration by flow cytometry of residual white blood cells (rWBCs) present in preserved samples recovered from leukoreduced (LR) blood and platelet products.

STUDY DESIGN AND METHODS: The stability of preserved WBCs, the equivalency of WBCs used for spiking, test method precision, specificity, reliability, accuracy, and sensitivity were investigated. For comparative purposes, WBC counts were also determined by Nageotte as well as by flow cytometry.

RESULTS: WBCs were stable up to 4 weeks at room temperature for all components by either method. Within methods, no differences were observed due to the source of WBC used for spiking purposes. By either method, test precision was acceptable (<20% coefficient of variation) and of similar reliability at a target value of 10 ± 5 WBCs per μL. The flow cytometric method was shown to be more specific and accurate than the Nageotte method. Sensitivity by either method was 0.1 WBCs per μL. On average, Nageotte counts were lower than those observed by flow cytometry.

CONCLUSIONS: These results demonstrate that WBCs in WBC stabilizing solution–treated samples from LR blood components were stabilized up to 4 weeks at room temperature and that rWBC determinations made with a WBC enumeration kit by flow cytometry have the required precision, specificity, reliability, and accuracy in the relevant test range. This validated WBC stabilization and flow cytometric counting method is considered acceptable as part of a quality control program for leukoreduced blood products.
Lack of effect of donor‐recipient Rh mismatch on outcomes after allogeneic hematopoietic stem cell transplantation
Authors: Wirk Baldeep , Klumpp Thomas R. , Ulicny John , Herman Jay H. , Gajewski James L. , Martin Mary E. , Emmons Robert V.B. , Mangan Kenneth F.
Published: September 2007

BACKGROUND: A recently published study has reported that donor‐recipient Rhesus (Rh)‐mismatched allogeneic hematopoietic stem cell transplantation independently led to significantly poorer survival. This suggests that donor‐recipient Rh mismatching is a risk factor in allogeneic hematopoietic stem cell transplantation and should be a criterion for donor selection.

STUDY DESIGN AND METHODS: To further evaluate this issue, 258 consecutive patients who underwent myeloablative or submyeloablative allogeneic hematopoietic stem cell transplantation at our institution were analyzed to determine the association between the Rh mismatch pattern and 5‐year actuarial survival. Secondary endpoints analyzed were the association of donor‐recipient Rh mismatch and event‐free survival, transplant‐related mortality, incidence of acute graft‐versus‐host disease (GVHD), and incidence of chronic GVHD.

RESULTS: In our analysis, there were no significant associations between donor‐recipient Rh mismatch pattern and overall survival, event‐free survival, transplant‐related mortality, incidence of acute GVHD, or incidence of chronic GVHD. On multivariate Cox proportional hazard analyses, the donor‐recipient Rh mismatch pattern was not independently predictive of overall survival.

CONCLUSION: Donor‐recipient Rh mismatch is not a risk factor in allogeneic hematopoietic stem cell transplantation and does not affect transplant outcomes.
Clinical Characteristics and Risk Stratification in Symptomatic and Asymptomatic Patients with Brugada Syndrome: Multicenter Study in Japan
Authors: TAKAGI MASAHIKO , YOKOYAMA YASUHIRO , AONUMA KAZUTAKA , AIHARA NAOHIKO , HIRAOKA MASAYASU ,   for the Japan Idiopathic Ventricular Fibrillation Study (J‐IVFS) Investigators
Published: September 2007

Background: Neither the clinical characteristics nor risk stratification in Brugada syndrome have been clearly determined. We compared the clinical and ECG characteristics of symptomatic and asymptomatic patients with Brugada syndrome to identify new markers for high‐risk patients.

Methods: A total of 188 consecutive individuals with Brugada syndrome (mean age 53 ± 14 years, 178 males) were enrolled in the Japan Idiopathic Ventricular Fibrillation Study (J‐IVFS). Clinical and ECG characteristics were evaluated in three groups of patients: Ventricular fibrillation (VF) group: patients with documented VF (N = 33); Syncope (Sy) group: patients with syncope without documented VF (N = 57); and asymptomatic (As) group: subjects without symptoms (N = 98). Their prognostic parameters were evaluated over a 3‐year follow‐up period.

Results: (1) Clinical characteristics: incidence of past history of atrial fibrillation (AF) was significantly higher in the VF and Sy groups than in the AS group (P = 0.04). (2) On 12‐lead ECG, r‐J interval in lead V2 and QRS duration in lead V6 were longest in the VF group (P = 0.001, 0.002, respectively). (3) Clinical follow‐up: during a mean follow‐up period of 37 ± 16 months, incidences of cardiac events (sudden death and/or VF) were higher in the symptomatic (VF/Sy) groups than in the As group (P < 0.0001). The r‐J interval in lead V2 ≥ 90 ms and QRS duration in lead V6 ≥ 90 ms were found to be possible predictors of recurrence of cardiac events in symptomatic patients.

Conclusions: Prolonged QRS duration in precordial leads was prominent in symptomatic patients. This ECG marker may be useful for distinguishing high‐ from low‐risk patients with Brugada syndrome.
A Note on Controlling the Number of False Positives
Authors: Korn Edward L. , Freidlin Boris
Published: September 2007

Summary:  Lehmann and Romano (2005, Annals of Statistics33, 1138–1154) discuss a Bonferroni‐type procedure that bounds the probability that the number of false positives is larger than a specified number. We note that this procedure will have poor power as compared to a multivariate permutation test type procedure when the experimental design accommodates a permutation test. An example is given involving gene expression microarray data of breast cancer tumors.
Resampling‐Based Multiple Testing Methods with Covariate Adjustment: Application to Investigation of Antiretroviral Drug Susceptibility
Authors: Yang Yang , DeGruttola Victor
Published: September 2007

SummaryIdentifying genetic mutations that cause clinical resistance to antiretroviral drugs requires adjustment for potential confounders, such as the number of active drugs in a HIV‐infected patient's regimen other than the one of interest. Motivated by this problem, we investigated resampling‐based methods to test equal mean response across multiple groups defined by HIV genotype, after adjustment for covariates. We consider construction of test statistics and their null distributions under two types of model: parametric and semiparametric. The covariate function is explicitly specified in the parametric but not in the semiparametric approach. The parametric approach is more precise when models are correctly specified, but suffer from bias when they are not; the semiparametric approach is more robust to model misspecification, but may be less efficient. To help preserve type I error while also improving power in both approaches, we propose resampling approaches based on matching of observations with similar covariate values. Matching reduces the impact of model misspecification as well as imprecision in estimation. These methods are evaluated via simulation studies and applied to a data set that combines results from a variety of clinical studies of salvage regimens. Our focus is on relating HIV genotype to viral susceptibility to abacavir after adjustment for the number of active antiretroviral drugs (excluding abacavir) in the patient's regimen.
A General Class of Pattern Mixture Models for Nonignorable Dropout with Many Possible Dropout Times
Authors: Roy Jason , Daniels Michael J.
Published: September 2007

SummaryIn this article we consider the problem of fitting pattern mixture models to longitudinal data when there are many unique dropout times. We propose a marginally specified latent class pattern mixture model. The marginal mean is assumed to follow a generalized linear model, whereas the mean conditional on the latent class and random effects is specified separately. Because the dimension of the parameter vector of interest (the marginal regression coefficients) does not depend on the assumed number of latent classes, we propose to treat the number of latent classes as a random variable. We specify a prior distribution for the number of classes, and calculate (approximate) posterior model probabilities. In order to avoid the complications with implementing a fully Bayesian model, we propose a simple approximation to these posterior probabilities. The ideas are illustrated using data from a longitudinal study of depression in HIV‐infected women.
Self‐Reported Changes in Food Safety Behaviors among Foodservice Employees: Impact of a Retail Food Safety Education Program
Authors: Anding Jenna D. , Boleman Chris , Thompson Britta
Published: September 2007

ABSTRACT:  A food safety education program developed for retail food establishments was evaluated to assess the extent to which participants were practicing selected behaviors linked to reducing the risk of foodborne disease both before and after the program. Scores from the state health department's Certified Food Manager (CFM) exam also were examined. Based on the 189 usable surveys returned, most respondents were female, middle age, and white with nearly 11 y of foodservice experience. Results revealed that after completing the program, participants reported practicing behaviors related to hand washing, maintaining safe food temperatures, preventing crosscontamination, and pest management more frequently (P < 0.05) compared to before the program. Effect size analysis indicated these results were also practically significant. Most (82.5%; n= 156) participants passed the CFM exam. Compared to those who failed the CFM exam, those who passed reported significantly higher changes in the adoption of selected behaviors; however, these results were of limited practical significance according to effect size analysis. Results suggest the food safety program is effective in promoting the adoption of food safety behaviors that can help reduce the risk of foodborne illness.
Synthesis and Mechanical Properties of Fully Dense Ti2SC
Authors: Amini Shahram , Barsoum Michel W. , El‐Raghy Tamer
Published: September 2007

Because the layered machinable ternary carbide, Ti2SC, has a significantly shorter c‐lattice parameter—as compared with most of the 50+ other so‐called Mn+1AXn (MAX) phase family (M=early transition metal; A=A group element and X=C or N and n=1–3) to which it belongs—it was postulated that its mechanical properties would be significantly different than the other MAX phases. In this work, fine‐grained (FG) and coarse‐grained (CG) polycrystalline fully dense Ti2SC samples were fabricated. Hot pressing Ti2SC powders, at 1500°C under a stress of ∼45 MPa for 5 h resulted in FG (2–4 μm) samples which and upon further annealing for 20 h at 1600°C resulted in CG (10–20 μm) ones. No peaks other than those associated with Ti2SC and an impurity anatase phase, with a volume fraction of ∼6 vol% were observed in the XRD patterns and micrographs. The average Vickers hardness in the 2–300 N range is 8±2 GPa with the FG samples being slightly harder. This hardness is the highest of any of the MAX phases characterized to date. Also in contrast to all MAX phases, cracks extended from the corners of Vickers indents in the FG samples. From these cracks the fracture toughness was estimated and found to increase more or less linearly with load from ≈4 to 6 MPa·m1/2 as the Vickers force was increased from 50 to 300 N, respectively. The room temperature compressive stress of the FG samples was 1.4±0.2 GPa; the failure mode was brittle. Its Young's modulus—also one of the highest for a M2AX phase measured to date—was 316±2 GPa. There was no evidence for incipient kink band formation during simple compression. The latter is attributed, in part, to the fine grain size of the hot‐pressed material.
Effects of the Heat‐Treatment Conditions on the Crystallographic Orientation of Pb(Zr,Ti)O3 Thin Films Prepared by Polyvinylpyrrolidone‐Assisted Sol–Gel Method
Authors: Yamano Akihiro , Kozuka Hiromitsu
Published: September 2007

The effects of heat‐treatment conditions on crystallographic orientation was studied on single layer, 0.14–0.19‐μm‐thick Pb(Zr0.53Ti0.47)O3 (PZT) films deposited on Pt(111)/TiO2/SiO2/Si(100) substrates by spin‐coating using a Pb(NO3)2–Zr(OC3H7n)4–Ti(OC3H7i)4—polyvinylpyrrolidone (PVP)–CH3COCH2COCH3–CH3OC2H4OH–n‐CH3OH solution. The gel films were fired either by placing the coated substrates on an alumina boat and inserting them into an electric furnace of 500°–900°C, or by placing them on a hot mullite plate of 500°–900°C so that the rear side of the substrate was in contact with the hot plate. When the samples were heated by placing on a hot mullite plate, (001)/(100) orientation of PZT occurred even at firing temperatures as low as 600°C, and the films were more completely oriented than those heated by inserting in a furnace along with an alumina boat. This suggests that either the higher heating rates or the heating from the substrate side would promote the oriented crystallization. However, when the gel films were heated up in a near‐infrared (IR) image furnace, preferential (001)/(100) orientation was observed even at low heating rates. The Si(100) substrates generate heat in the image furnace, allowing the gel films to be heated from the substrate side, which was suggested by the fact that the films do not absorb the near‐IR light while the substrate does. Therefore it can be concluded that heating the gel films from the substrate side is effective for the orientation of the films, by which orientation is realized even in PZT films derived from PVP‐containing alkoxide solutions.
Effects of Brazing Time and Temperature on the Microstructure and Mechanical Properties of Aluminum Air Brazed Joints
Authors: Kim Jin Yong , Weil K. Scott
Published: September 2007

High‐purity aluminum foil was used to join alumina substrates directly in air at temperatures ranging from 800° to 1200°C and soak times of 1–100 h. It was found that the bend strengths of the resulting Al2O3/Al/Al2O3 joints generally increase with increasing brazing temperature and time, with a maximum bend strength of 135 MPa on average achieved in samples joined at 1200°C for 100 h. Additionally it was determined that measurable ductility is retained in the joint even after exposure under extended high‐temperature conditions. During joining, an Al2O3 scale forms along the interface between the aluminum and adjacent substrates. An increase in brazing temperature and/or time leads to intergrowth and sintering between this thermally grown oxide layer and the substrate surface, which appears to be the primary source of improved joint strength. Fracture analysis indicates that the Al2O3/Al/Al2O3 joints generally fail via one of three mechanisms, (1) by de‐bonding along the foil/substrate interface in specimens that were joined at low temperature or held at temperature for an insufficient period of time; (2) by ductile rupture in specimens that were joined at conditions that promoted sintering between the oxidized foil and adjacent alumina faying surfaces, but left behind a continuous residual aluminum layer within the joint; or (3) by mixed‐mode fracture in specimens joined at high temperature and long exposure times, in which the thermally grown alumina that forms between the two substrates is interrupted by dispersed pockets of residual aluminum metal.
Tyrosine phosphorylation‐dependence of caveolae‐mediated endocytosis
Authors: Sverdlov Maria , Shajahan Ayesha N. , Minshall Richard D.
Published: September 2007

Introduction

SRC signaling in caveolae‐mediated endocytosis

Potential role of SRC‐mediated phosphorylation of caveolin‐1 in caveolae‐mediated endocytosis

Role of actin cytoskeleton in caveolae‐mediated endocytosis

Conclusion

Caveolae are flask‐shaped plasma membrane invaginations that mediate endocytosis and transcytosis of plasma macromolecules, such as albumin, insulin and low‐density lipoprotein (LDL), as well as certain viruses, bacteria and bacterial toxins. Caveolae‐mediated transcytosis of macromolecules is critical for maintaining vascular homeostasis by regulating the oncotic pressure gradient and tissue delivery of drugs, vitamins, lipids and ions. Entrapment of cargo within caveolae induces activation of signalling cascades leading to caveolae fission and internalization. Activation of Src tyrosine kinase is an early and essential step that triggers detachment of loaded caveolae from the plasma membrane. In this review, we examine how Srcmediated phosphorylation regulates caveolae‐mediated transport by orchestrating the localization and activity of essential proteins of the endocytic machinery to regulate caveolae formation and fission.
The Philosophy of Social Science: Metaphysical and Empirical
Authors: Guala Francesco
Published: September 2007

Ontological debates have always been prominent in the philosophy of social science. Philosophers have typically conceived of such debates as pre‐scientific attempts to reform social scientific practice, rather than as post‐scientific reflections on a firm body of scientific knowledge. Two celebrated contemporary research programs in social ontology – collective intentionality and evolutionary game theory – also follow this approach. In this paper I illustrate their central elements and criticize their weak empirical foundations. I finish by reviewing some work that combines empirical evidence with theoretical reflection, and suggest that it constitutes the way forward in the philosophy of social science.
Knowledge, Space and Biotechnology
Authors: Birch Kean
Published: September 2007

This article outlines and reviews the trends in research on the biotechnology industry over the last 20 years, drawing a distinction between theories that emphasise knowledge processes and those that focus on spatial processes. It covers research in strategic management, innovation studies, political economy, new economic geography, cluster theory, regional studies and economic geography. In reviewing these two strands of literature, it develops a synthesis of the two perspectives called theknowledge‐space dynamic, which seeks to combine insights from both to better explain and situate biotechnology innovation.
Comparison of tracheal aspirates before and after high‐speed treadmill exercise in racehorses
Authors: MALIKIDES N , HUGHES KJ , HODGSON JL
Published: September 2007

Objective  To determine whether percentages of neutrophils in tracheal aspirate (TA) samples collected from racehorses are increased after exercise and whether interpretation of results from TA samples taken before and after exercise agree.

Design  Case series of 40 young Thoroughbred and Standardbred racehorses in race training presented for evaluation of poor performance.

Procedure  TA samples were collected endoscopically from racehorses presented for poor performance 24 h before and 1 to 2 h after high speed treadmill exercise testing. Aliquots of the retrieved fluid were cytocentrifuged and smears were stained with Diff‐Quik®. Mean neutrophil counts were expressed as percentages of the total number of inflammatory cells counted and subsequently were categorised as either above or below an accepted cut‐off of 20%. Comparisons between percentages of neutrophils before and after exercise were made.

Results  Percentage of neutrophils from TA samples obtained from racehorses after exercise was significantly higher than neutrophil percentages from TA samples collected from the same horse before exercise. In horses with TA specimens that were categorised as having ≤ 20% neutrophils before treadmill exercise, the percentage of neutrophils in their TA specimens after exercise was, on average, significantly higher and was greater than the cut‐off value of 20%.

Conclusion  Recent strenuous exercise may change the proportion of neutrophils in lower airways of racehorses and practitioners should be aware of this when collecting and interpreting the results from TA samples. The most practical time for collection of a TA sample to obtain the most diagnostically useful information might be after a suitable washout period of at least 1 to 2 h post‐exercise.
Distributions of the paralysis ticks Ixodes cornuatus and Ixodes holocyclus in south‐eastern Australia
Authors: JACKSON J , BEVERIDGE I , CHILTON NB , ANDREWS RH
Published: September 2007

Objective  To describe the actual and potential geographic distributions of Ixodes cornuatus and I holocyclus in south‐eastern Australia.

Procedure  Examination of ticks from museum collections and trapped animals were made. (Bioclimatic analysis BIOCLIM) was used to predict potential distributions.

Results  I holocyclus was collected from rodents (Rattus fuscipes, R lutreolus, R rattus), wombats (Vombatus ursinus), cats and dogs in Gippsland and I cornuatus was collected from rodents (R fuscipes), wombats, cats and dogs in central Victoria. All life‐cycle stages of both species were collected during the warmer months of the year. The known distribution of the two species was established from specimens in museum collections and suggested that a boundary between the two may exist in eastern Gippsland. BIOCLIM suggested that the area immediately to the east of Melbourne was climatically suitable for I holocyclus, although no endemic foci of infection are currently known from this region. The potential distribution of I cornuatus included east Gippsland and the Otway Ranges, areas in which the tick is not currently known to occur.

Conclusions  I holocyclus and I cornuatus have more restricted distributions than current collections suggest and therefore may have the possibility to extend their geographical ranges in the future.