bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term particulate matter exposure and mortality: a review of European epidemiological studies
Authors: Pelucchi Claudio , Negri Eva , Gallus Silvano , Boffetta Paolo , Tramacere Irene , La Vecchia Carlo
Published: December 2009

Background

Several studies considered the relation between long-term exposure to particulate matter (PM) and total mortality, as well as mortality from cardiovascular and respiratory diseases. Our aim was to provide a comprehensive review of European epidemiological studies on the issue.

Methods

We searched the Medline database for epidemiological studies on air pollution and health outcomes published between January 2002 and December 2007. We also examined the reference lists of individual papers and reviews. Two independent reviewers classified the studies according to type of air pollutant, duration of exposure and health outcome considered. Among European investigations that examined long-term PM exposure we found 4 cohort studies (considering total and cardiopulmonary mortality), 1 case-control study (considering mortality from myocardial infarction), and 4 ecologic studies (2 studies considering total and cardiopulmonary mortality and 2 studies focused on cardiovascular mortality).

Results

Measurement indicators of PM exposure used in European studies, including PM10, PM2.5, total suspended particulate and black smoke, were heterogeneous. This notwithstanding, in all analytic studies total mortality was directly associated with long-term exposure to PM. The excesses in mortality were mainly due to cardiovascular and respiratory causes. Three out of 4 ecologic studies found significant direct associations between PM indexes and mortality.

Conclusion

European studies on long-term exposure to PM indicate a direct association with mortality, particularly from cardiovascular and respiratory diseases.
Comparative study of paediatric prescription drug utilization between the spanish and immigrant population
Authors: Gimeno-Feliu Luís A , Armesto-Gómez Javier , Macipe-Costa Rosa , Magallón-Botaya Rosa
Published: December 2009

Background

The immigrant population has increased greatly in Spain in recent years to the point where immigrants made up 12% of the infant population in 2008. There is little information available on the profile of this group with regard to prescription drug utilization in universal public health care systems such as that operating in Spain. This work studies the overall and specific differences in prescription drug utilization between the immigrant and Spanish population.

Methods

Use was made of the Aragonese Health Service databases for 2006. The studied population comprises 159,908 children aged 0-14 years, 13.6% of whom are foreign nationals. Different utilization variables were calculated for each group. Prescription-drug consumption is measured in Defined Daily Doses (DDD) and DDD/1000 persons/day/(DID).

Results

A total of 833,223 prescriptions were studied. Utilization is lower for immigrant children than in Spanish children for both DID (66.27 v. 113.67) and average annual expense (€21.55 v. €41.14). Immigrant children consume fewer prescription drugs than Spanish children in all of the therapy groups, with the most prescribed (in DID) being: respiratory system, anti-infectives for systemic use, nervous system, sensory organs. Significant differences were observed in relation to the type of drugs and the geographical background of immigrants.

Conclusion

Prescription drug utilization is much greater in Spanish children than in immigrant children, particularly with reference to bronchodilators (montelukast and terbutaline) and attention-disorder hyperactivity drugs such as methylphenidate. There are important differences regarding drug type and depending on immigrants' geographical backgrounds that suggest there are social, cultural and access factors underlying these disparities.
The occurrence of antimicrobial resistance and class 1 integrons among commensal Escherichia coli isolates from infants and elderly persons
Authors: Sepp Epp , Stsepetova Jelena , Lõivukene Krista , Truusalu Kai , Kõljalg Siiri , Naaber Paul , Mikelsaar Marika
Published: December 2009

Background

The aim of our study was to compare the presence of theintI1gene and its associations with the antibiotic resistance of commensalEscherichia colistrains in children with/without previous antibiotic treatments and elderly hospitalized/healthy individuals.

Methods

One-hundred-and-fifteen intestinalE. colistrains were analyzed: 30 strains from 10 antibiotic-naive infants; 27 from 9 antibiotic-treated outpatient infants; 30 from 9 healthy elderly volunteers; and 28 from 9 hospitalized elderly patients. The MIC values of ampicillin, cefuroxime, cefotaxime, gentamicin, ciprofloxacin, and sulfamethoxazole were measured by E-test andIntI1was detected by PCR.

Results

Out of the 115 strains, 56 (49%) carried class 1 integron genes. Comparing persons without medical interventions, we found in antibiotic-naive children a significantly higher frequency of integron-bearing strains and MIC values than in healthy elderly persons (53% versus 17%; p < 0.01). Evaluating medical interventions, we found a higher resistance and frequency of integrons in strains from hospitalized elderly persons compared with non-hospitalized ones. Children treated with antibiotics had strains with higher MIC values (when compared with antibiotic-naive ones), but the integron-bearing in strains was similar. In most cases, the differences in resistance between the groups (integron-positive and negative strains separately) were higher than the differences between integron-positive and negative strains within the groups.

Conclusion

The prevalence of integrons in commensalE. colistrains in persons without previous medical intervention depended on age. The resistance of integron-carrying and non-carrying strains is more dependent on influencing factors (hospitalization and antibiotic administration) in particular groups than merely the presence or absence of integrons.
Three synchronous primary carcinomas in a patient with HNPCC associated with a novel germline mutation in MLH1: Case report
Authors: Valenzuela Cristian D , Moore Harvey G , Huang William C , Reich Elsa W , Yee Herman , Ostrer Harry , Pachter H Leon
Published: December 2009

Background

MLH1 is one of six known genes responsible for DNA mismatch repair (MMR), whose inactivation leads to HNPCC. It is important to develop genotype-phenotype correlations for HNPCC, as is being done for other hereditary cancer syndromes, in order to guide surveillance and treatment strategies in the future.

Case presentation

We report a 47 year-old male with hereditary nonpolyposis colorectal cancer (HNPCC) associated with a novel germline mutation in MLH1. This patient expressed a rare and severe phenotype characterized by three synchronous primary carcinomas: ascending and splenic flexure colon adenocarcinomas, and ureteral carcinoma. Ureteral neoplasms in HNPCC are most often associated with mutations in MSH2 and rarely with mutations in MLH1. The reported mutation is a two base pair insertion into exon 10 (c.866_867insCA), which results in a premature stop codon.

Conclusion

Our case demonstrates that HNPCC patients with MLH1 mutations are also at risk for ureteral neoplasms, and therefore urological surveillance is essential. This case adds to the growing list of disease-causing MMR mutations, and contributes to the development of genotype-phenotype correlations essential for assessing individual cancer risk and tailoring of optimal surveillance strategies. Additionally, our case draws attention to limitations of the Amsterdam Criteria and the need to maintain a high index of suspicion when newly diagnosed colorectal cancer meets the Bethesda Criteria. Establishment of the diagnosis is the crucial first step in initiating appropriate surveillance for colorectal cancer and other HNPCC-associated tumors in at-risk individuals.
Human mammary cancer progression model recapitulates methylation events associated with breast premalignancy
Authors: Dumont Nancy , Crawford Yongping G , Sigaroudinia Mahvash , Nagrani Shefali S , Wilson Matthew B , Buehring Gertrude C , Turashvili Gulisa , Aparicio Samuel , Gauthier Mona L , Fordyce Colleen A , McDermott Kimberly M , Tlsty Thea D
Published: December 2009

Introduction

We have previously identified a rare subpopulation of variant human mammary epithelial cells (vHMEC) with repressed p16INK4A that exist in disease-free women yet display premalignant properties, suggesting that they have engaged the process of malignant transformation. In order to gain insight into the molecular alterations required for vHMEC to progress to malignancy, and to characterize the epigenetic events associated with early progression, we examined the effect of oncogenic stress on the behavior of these cells.

Methods

HMEC that express p16INK4A and vHMEC that do not, were transduced with constitutively active Ha-rasV12 and subsequently exposed to serum to determine whether signals from the cellular microenvironment could cooperate with ras to promote the malignant transformation of vHMEC. Epigenetic alterations were assessed using methylation-specific polymerase chain reaction (PCR).

Results

vHMEC expressing Ha-rasV12 (vHMEC-ras) bypassed the classic proliferative arrest that has been previously documented in normal fibroblasts following oncogenic stress, and that we also observe here in normal HMEC. Moreover, vHMEC-ras cells exhibited many additional alterations that are observed during progression to malignancy such as the generation of chromosomal abnormalities, upregulation of telomerase activity, immortalization following exposure to serum, and anchorage-independent growth, but they did not form tumors following orthotopic injection in vivo. Associated with their early progression to malignancy was an increase in the number of genes methylated, two of which (RASSF1A and SFRP1) were also methylated in other immortalized mammary cell lines as well as in breast cancer cells and tissues.

Conclusions

We have characterized a mammary progression model that recapitulates molecular and methylation alterations observed in many breast cancers. Our data suggest that concomitant methylation of RASSF1A and SFRP1 marks an early event in mammary transformation and may thus have prognostic potential.
Characterization of Schlafen-3 expression in effector and regulatory T cells
Authors: Condamine Thomas , Le Luduec Jean-Benoît , Chiffoleau Elise , Bériou Gaëlle , Louvet Cédric , Heslan Michele , Tilly Gaëlle , Cuturi Maria-Cristina
Published: December 2009

The study's results suggest that Slfn3 could have a role in T cell differentiation and activation.

Members of the Slfn protein family have been implicated in the regulation of cell growth, hematopoietic cell differentiation, and T cell development/differentiation in the thymus. Ten members of this family have been described in the mouse, and they have been divided into three subgroups based on the overall sequence homology and the size of the encoded proteins. We have identified Slfn3, a member of Subgroup II, as an overexpressed gene in CD4+ CD25+ T cells in the periphery. Interestingly, we demonstrate that upon activation and proliferation, Slfn3 mRNA is down-regulated in CD4+ CD25+ Tregs and up-regulated in CD4+ CD25– Teffs. Moreover, TGF-β inhibits the expression of Slfn3 in anti-CD3/CD28-activated CD4+ T cells, and the same conditions induce FoxP3 mRNA. Our results suggest that Slfn3 could have a role in T cell differentiation and activation.
Simulation of programmed incremental open-die forging processes based on spread coefficient and geometric transformation
Authors: Yan C , Gao F
Published: December 2009

A typical open-die forging process, square bar drawing, is investigated, which is the most commonly adopted process in a programmed open-die forging system that includes press and co-ordinated forging manipulators. The simulation algorithm for the square bar drawing between simple dies is proposed based on the spread coefficient theory and geometric transformation. The geometry of the as-forged workpiece is modelled by using the concept of the Characteristic Point Set; the spatial motion of the workpiece is computed by using the norma-lized co-ordinate transformation; and the plastic deformation of the deforming part is described by using a geometric transformation based on spread coefficient and reasonable simplifications. The real-time simulation algorithm of the programmed forging process is then formed, which can be used in pass schedule design, providing codes for the coordination control of the press and the manipulator, and can be incorporated into the virtual reality integrated forging plant as the process simulation model.
A full-scale experimental and modelling study of ballast flight under high-speed trains
Authors: Quinn A D , Hayward M , Baker C J , Schmid F , Priest J A , Powrie W
Published: December 2009

Recent experience with the operation of high-speed railways in the UK and elsewhere has revealed the phenomenon, termed ‘ballast flight’, of ballast particles becoming airborne during the passage of trains, potentially causing damage to both the railhead and the vehicle. This article reports the results of an investigation into the mechanical and aerodynamic forces acting on ballast particles that are generated during the passage of a high-speed train and addresses the question whether these might offer a possible explanation for the initiation of ballast flight. As the high-speed trains passed, measurements were made of the air pressure and velocity at various locations across the track, and of the velocity and acceleration of the track system (sleeper and rails) and the ballast itself. The aerodynamic forces exerted on a suspended ballast particle were also measured. An analytical model of the behaviour of small ballast particles was constructed to assist in the interpretation of the measured data. Analysis of the data and modelling suggest that neither mechanical forces nor aerodynamic forces in isolation are likely to be sufficient to initiate ballast flight under the conditions investigated, but that the phenomenon could arise from a combination of the two effects. It appears that the process is stochastic in nature: further work, with an increased number of measurements, is required to explore this.
Characterization of forces, dynamic response, and sound radiation from an articulated switch sleeper in a turnout system
Authors: Zhu J Y , Thompson D J
Published: December 2009

Pre-assembled turnouts have recently been introduced with split concrete sleepers joined by elastic coupling plates. Their effect on the forces, vibration response, and sound radiation as trains run through a turnout is studied here using a calculation model for a whole turnout based on the finite-element method. The non-linear characteristics of the ballast's support under the sleepers, as well as the special construction of the articulated joints, are included. It is shown that compared with the normal integral sleeper design, the track with articulated switch sleepers has a lower rigidity, which changes more evenly along the track and improves its dynamic performance. Furthermore, the fatigue strength of an articulated switch sleeper is higher due to its lower stress amplitudes. Additionally, when the vehicles are running on the main turnout route, as the switch sleepers’ vibration behaviour is modified, the articulated joints effectively reduce the impact loading of the ballast at the end of the sleeper under the turnout branch track. This will extend the life of the ballast bed. Finally, the sound radiation from the articulated switch sleeper is very low in the hinged short part and is reduced by about 0.6 dB for the total length.
Efficient Pollution Regulation: Getting the Prices Right
Authors: Muller Nicholas Z. , Mendelsohn Robert
Published: December 2009

This paper argues for efficient environmental regulations that equate the marginal damage of pollution to marginal abatement costs across space. The paper estimates the source-specific marginal damages of air pollution and calculates the welfare gain from making the current sulfur dioxide allowance trading program for power plants more efficient. The savings from using trading ratios based on marginal damages are between $310 and $940 million per year. The potential savings from setting aggregate emissions efficiently and from including more sources of air pollution are many times higher. (JEL H23, Q53, Q58)
Has Moral Hazard Become a More Important Factor in Managerial Compensation?
Authors: Gayle George-Levi , Miller Robert A.
Published: December 2009

We estimate a principal-agent model of moral hazard with longitudinal data on firms and managerial compensation over two disjoint periods spanning 60 years to investigate increased value and variability in managerial compensation. We find exogenous growth in firm size largely explains these secular trends in compensation. In our framework, exogenous firm size works through two channels. First, conflicts of interest between shareholders and managers are magnified in large firms, so optimal compensation plans are now more closely linked to insider wealth. Second, the market for managers has become more differentiated, increasing the premium paid to managers of large versus small firms. (JEL D82, L25, M12, M52)
Selling to Overconfident Consumers
Authors: Grubb Michael D.
Published: December 2009

Consumers may overestimate the precision of their demand forecasts. This overconfidence creates an incentive for both monopolists and competitive firms to offer tariffs with included quantities at zero marginal cost, followed by steep marginal charges. This matches observed cellular phone service pricing plans in the United States and elsewhere. An alternative explanation with common priors can be ruled out in favor of overconfidence based on observed customer usage patterns for a major US cellular phone service provider. The model can be reinterpreted to explain the use of flat rates and late fees in rental markets, and teaser rates on loans. Nevertheless, firms may benefit from consumers losing their overconfidence. (JEL D12, L11, L96)
The Evolution of Time Preference with Aggregate Uncertainty
Authors: Robson Arthur J. , Samuelson Larry
Published: December 2009

We examine the evolutionary foundations of intertemporal preferences. When all the risk affecting survival and reproduction is idiosyncratic, evolution selects for agents who maximize the discounted sum of expected utility, discounting at the sum of the population growth rate and the mortality rate. Aggregate uncertainty concerning survival rates leads to discount rates that exceed the sum of population growth rate and death rate, and can push agents away from exponential discounting. (JEL D11, D81, D91)
On the Possibility of Credit Rationing in the Stiglitz-Weiss Model
Authors: Arnold Lutz G. , Riley John G.
Published: December 2009

Contrary to what is usually assumed, the expected revenue for lenders as a function of the loan rate cannot be globally hump-shaped in the Stiglitz-Weiss (1981) adverse selection model with a continuum of types. This has important implications. First, if there is credit rationing, there must be at least two equilibrium loan rates. Second, while at the low rate loans are rationed, all those applicants willing to pay the high rate are then served. Numerical analysis shows that unless the joint distribution of risk class and output is rather special, the two loan rate outcome with rationing is unlikely. (JEL D82, G21)
Peer-Induced Fairness in Games
Authors: Ho Teck-Hua , Su Xuanming
Published: December 2009

People exhibit peer-induced fairness concerns when they look to their peers as a reference to evaluate their endowments. We analyze two independent ultimatum games played sequentially by a leader and two followers. With peer-induced fairness, the second follower is averse to receiving less than the first follower. Using laboratory experimental data, we estimate that peer-induced fairness between followers is two times stronger than distributional fairness between leader and follower. Allowing for heterogeneity, we find that 50 percent of subjects are fairness-minded. We discuss how peer-induced fairness might limit price discrimination, account for low variability in CEO compensation, and explain pattern bargaining. (JEL C72, D63)
Mental Accounting in Portfolio Choice: Evidence from a Flypaper Effect
Authors: Choi James J. , Laibson David , Madrian Brigitte C.
Published: December 2009

Consistent with mental accounting, we document that investors sometimes choose the asset allocation for one account without considering the asset allocation of their other accounts. The setting is a firm that changed its 401(k) matching rules. Initially, 401(k) enrollees chose the allocation of their own contributions, but the firm chose the match allocation. These enrollees ignored the match allocation when choosing their own-contribution allocation. In the second regime, enrollees selected both accounts' allocations, leading them to integrate the two. Own-contribution allocations before the rule change equal the combined own- and match-contribution allocations afterward, whereas combined allocations differ sharply across regimes. (JEL G11, J32)
Endogenous Verifiability and Relational Contracting
Authors: Kvaløy Ola , Olsen Trond E.
Published: December 2009

Principal-agent models usually invoke the strong assumption that the parties know for sure ex ante whether a variable is verifiable or not. This paper assumes that only the probability of verification is known, and that this probability is endogenously determined. We analyze a principal-agent relationship where the verifiability of the agent's output is determined by the principal's investment in drafting an explicit contract. The model is well suited for analyzing the relationship between explicit contracting, legal courts, trust, and relational contracting. In particular, we show how trust—established through repeated interaction—and legal courts may induce contractual incompleteness. (JEL D82, D86)
Four Projection Streams from Primate V1 to the Cytochrome Oxidase Stripes of V2
Authors: Federer Frederick , Ichida Jennifer M. , Jeffs Janelle , Schiessl Ingo , McLoughlin Niall , Angelucci Alessandra
Published: December 2009

In the primate visual system, areas V1 and V2 distribute information they receive from the retina to all higher cortical areas, sorting this information into dorsal and ventral streams. Therefore, knowledge of the organization of projections between V1 and V2 is crucial to understand how the cortex processes visual information. In primates, parallel output pathways from V1 project to distinct V2 stripes. The traditional tripartite division of V1-to-V2 projections was recently replaced by a bipartite scheme, in which thin stripes receive V1 inputs from blob columns, and thick and pale stripes receive common input from interblob columns. Here, we demonstrate that thick and pale stripes, instead, receive spatially segregated V1 inputs and that the interblob is partitioned into two compartments: the middle of the interblob projecting to pale stripes and the blob/interblob border region projecting to thick stripes. Double-labeling experiments further demonstrate that V1 cells project to either thick or pale stripes, but rarely to both. We also find laminar specialization of V1 outputs, with layer 4B contributing projections mainly to thick stripes, and no projections to one set of pale stripes. These laminar differences suggest different contribution of magno, parvo, and konio inputs to each V1 output pathway. These results provide a new foundation for parallel processing models of the visual system by demonstrating four V1-to-V2 pathways: blob columns-to-thin stripes, blob/interblob border columns-to-thick stripes, interblob columns-to-palelateralstripes, layer 2/3–4A interblobs-to-palemedialstripes.
Dynamic Reweighting of Visual and Vestibular Cues during Self-Motion Perception
Authors: Fetsch Christopher R. , Turner Amanda H. , DeAngelis Gregory C. , Angelaki Dora E.
Published: December 2009

The perception of self-motion direction, or heading, relies on integration of multiple sensory cues, especially from the visual and vestibular systems. However, the reliability of sensory information can vary rapidly and unpredictably, and it remains unclear how the brain integrates multiple sensory signals given this dynamic uncertainty. Human psychophysical studies have shown that observers combine cues by weighting them in proportion to their reliability, consistent with statistically optimal integration schemes derived from Bayesian probability theory. Remarkably, because cue reliability is varied randomly across trials, the perceptual weight assigned to each cue must change from trial to trial. Dynamic cue reweighting has not been examined for combinations of visual and vestibular cues, nor has the Bayesian cue integration approach been applied to laboratory animals, an important step toward understanding the neural basis of cue integration. To address these issues, we tested human and monkey subjects in a heading discrimination task involving visual (optic flow) and vestibular (translational motion) cues. The cues were placed in conflict on a subset of trials, and their relative reliability was varied to assess the weights that subjects gave to each cue in their heading judgments. We found that monkeys can rapidly reweight visual and vestibular cues according to their reliability, the first such demonstration in a nonhuman species. However, some monkeys and humans tended to over-weight vestibular cues, inconsistent with simple predictions of a Bayesian model. Nonetheless, our findings establish a robust model system for studying the neural mechanisms of dynamic cue reweighting in multisensory perception.
Associatively Learned Representations of Taste Outcomes Activate Taste-Encoding Neural Ensembles in Gustatory Cortex
Authors: Saddoris Michael P. , Holland Peter C. , Gallagher Michela
Published: December 2009

Through learning processes, cues associated with emotionally salient reinforcing outcomes can come to act as substitutes for the reinforcer itself. According to one account of this phenomenon, the predictive cue associatively elicits a representation of the expected outcome by reactivating cells responsible for encoding features of the primary reinforcer. We tested this hypothesis by examining the role of neural ensembles in gustatory cortex (GC) during receipt of gustatory stimuli (sucrose and water) and cues associated with those stimuli using the immediate early genes (IEGs)ArcandHomer1a. Because these plasticity-related IEGs are expressed in the neuronal nucleus 5 and 30 min, respectively, after salient events, we examined how individual neurons encoded these stimuli in two separate behavioral epochs. In experiment 1, we showed that tasting identical sucrose solutions, but not tasteless water, in the two epochs increased both IEG activity and the degree of overlap between neural ensembles in GC. In experiment 2, odor cues associated with sucrose, but not water, evoked potentiation of IEG activity in GC similar to sucrose itself. Surprisingly, lesions of the basolateral amygdala had minimal effects on associative encoding in GC. Finally, these associatively driven representations of sucrose appeared to be outcome specific, as neural ensembles that were activated by the sucrose-associated cue were also activated by sucrose itself. This degree of overlap between associative and primary taste activity at the ensemble level suggests that GC neurons encode important information about anticipated outcomes. Such representations may provide outcome-specific information for guiding goal-directed behavior.
45,X/46,XX mosaicism below 30% of aneuploidy: clinical implications in adult women from a reproductive medicine unit
Authors: Homer L , Le Martelot M-T , Morel F , Amice V , Kerlan V , Collet M , De Braekeleer M
Published: December 2009

Objective

Turner's syndrome (TS) is well known, but prognosis for 45,X/46,XX mosaicism below 30% of aneuploidy has not been established. We evaluated differences in clinical features and biological parameters between patients with numerical sex chromosome mosaicism diagnosed incidentally and control women.

Design

Retrospective observational study of clinical features and biological parameters.

Methods

Standard endocrinological and gynecological examination was done and early-follicular-phase blood values were collected from the medical records of women aged 21–43, who were referred to our ward from 1996 to 2006 because of infertility and were karyotyped. Seventy-one women with sex chromosome mosaicism (45,X/46,XX) ranging from 4 to 28% were assigned a chromosomally normal woman (46,XX) matched according to age (n=71).

Results

In group 45,X/46,XX, 8% or more of aneuploidy accounted for a smaller height compared to controls (P=0.01). Body mass index was increased from 6% of aneuploidy (P=0.02) and was positively correlated to the percentage of 45,X cells (P=0.0001); menarche occurred earlier from 10% of aneuploidy (P=0.01) and was inversely correlated to the percentage of 45,X cells (P=0.045). No difference was found between the groups for FSH, LH, estradiol, inhibin B, and TSH values. Spontaneous abortions were more frequent in case of mosaicism (P=0.01), and recurrence was positively correlated to the percentage of aneuploidy (P=0.008).

Conclusion

Sex chromosome mosaicism is responsible for clinical changes from 6% of aneuploidy, corresponding to the main phenotypical features of TS.
Dimethylarginines: their vascular and metabolic roles in Africans and Caucasians
Authors: Schutte Aletta E , Schutte Rudolph , Huisman Hugo W , van Rooyen Johannes M , Fourie Carla M T , Malan Leoné , Malan Nico T , Schwedhelm Edzard , Strimbeanu Sebastian , Anderssohn Maike , Böger Rainer H
Published: December 2009

Objective

Alarming increases in hypertension and type 2 diabetes among Africans accentuate the need to identify factors that could serve as targets for prevention or treatment. In Caucasian populations, asymmetric dimethylarginine (ADMA), the predominant endogenous nitric oxide synthase inhibitor, is associated with cardiovascular disease and insulin resistance (IR). ADMA's counterpart, symmetric dimethylarginine (SDMA), originally thought to be inert, was recently also linked with cardiovascular risk. Since little information regarding ADMA or SDMA is available for Africans, our aim was to explore the relationships of ADMA and SDMA with measures of arterial stiffness and IR in Africans and Caucasians from South Africa.

Methods

The study consisted of 235 nonsmoking, nondiabetic, nonobese, human immunodeficiency virus-uninfected Africans (n=64) and Caucasians (n=171), aged 20–70 years. We measured blood pressure, pulse wave velocity, ADMA, SDMA, and IR (homeostasis model assessment, HOMA).

Results

African and Caucasian men had similar ADMA and SDMA, whereas Caucasian women had higher ADMA and SDMA than African women (P<0.05). African men and Caucasian women indicated strong correlations of ADMA with arterial stiffness (r=0.47, P=0.021; r=0.26, P=0.008), confirmed in multivariate analyses. Caucasian participants showed negative associations between SDMA and HOMA, being strongest in the men (r=−0.41; P=0.002).

Conclusion

Our results indicate that ADMA is independently associated with vascular dysfunction in African men and Caucasian women. A strong, independent negative association of SDMA with IR was found only in Caucasian participants. The molecular explanation for this is unclear, but these findings motivate experimental studies that could shed more light on these relationships.
The role of insulin-like growth factors (IGF) in cell division processes and in malignancy
Authors: Vasas Péter , Winslet Marc C. , Shi Yu Yang
Published: December 2009

Az inzulinszerű növekedési faktor (IGF) szerepe a sejtosztódásban és a daganatképződésben kiterjedt kutatás tárgyát képezi. Korábban nyilvánvalóvá vált, hogy az IGF- és a hozzá kötődő jelátviteli rendszer proliferatív, differenciálódást elősegítő és antiapoptotikus hatást vált ki. Az IGF májban történő fiziológiás termelődésén túl jelentős mennyiségben kerül előállításra a daganatos sejtekben, s a keringésben fiziológiásan elérhető mennyiséget az IGF-kötő fehérjék (IGFBP) szabályozzák. A receptor-ligand kapcsolódást követően kialakuló tirozinkináz-aktivitás a foszfatidil-inozitol-3-kináz (PI3-K), valamint p38 mitogén aktiválta proteinkináz (MAPK) útvonalakon keresztül fejti ki hatását a sejtciklusra. Áttekintésre kerül a ligand, valamint a receptor bioszintézise, a jelátviteli rendszer működése és a daganatos sejtekben betöltött szerepe. A terápiás lehetőségek áttekintése során elemzésre kerülnek a preklinikai stádiumban levő szerek fontosabb ismérvei.
Surgical treatment of breast cancer – 2009
Authors: Lázár György
Published: December 2009

Az elmúlt két évtizedben az emlő onkológiai sebészete számos tekintetben megváltozott. Ennek az okai elsősorban az úgynevezett biológiai szemléletű gyógyítás, a daganatszűrés, a sebészeti technológiai fejlődés és a minőségbiztosítási elvek mindennapos használata. Egy újabb paradigmaváltásnak vagyunk tanúi, amelynek lényege, hogy a maximálisan radikális kezelést a minimális, de elégséges sebészi kezelési koncepció váltja föl. A sebészet mint szakma nemhogy le-, hanem egyre inkább felértékelődik, és továbbra is meghatározó az emlőrák gyógyításában.
Habitat Choice by Atlantic Salmon Parr in Relation to Turbulence at a Reach Scale
Authors: Enders Eva C. , Roy Mathieu L. , Ovidio Michaël , Hallot Éric J. , Boyer Claudine , Petit François , Roy André G.
Published: December 2009

The variables commonly used to describe the physical habitat of Atlantic salmon Salmo salar parr are average velocity, water depth, and substrate. A variety of micro- and mesohabitat models have been developed using these variables to assess habitat quality. However, Atlantic salmon parr live in highly turbulent streams and rivers in which intense fluctuations of water velocity occur. Laboratory experiments have shown that turbulence affects the behavior and energetics of fish. Nevertheless, habitat use in relation to the strong temporal variability of velocity in natural environments has rarely been studied. In this study, Atlantic salmon parr habitat was examined in relation to turbulence in the Patapédia River, Quebec. Rather than taking the usual approach of surveying a large population at one point in time, we used an intensive radiotelemetry tracking survey that focused on the habitat use of a few individual fish over an extended period. We analyzed habitat use in relation to several dynamic hydraulic variables. Our results revealed that under naturally turbulent conditions, the parr displayed high individual variability in their habitat use. Such heterogeneous use of habitat suggests that individuals are not constrained to a single habitat type. Furthermore, no differences were observed in habitat use among the four daily periods (dawn, day, dusk, and night) for individual parr.
Behavior of Steelhead Fry in a Laboratory Stream is Affected by Fish Density but Not Rearing Environment
Authors: Riley Stephen C. , Tatara Christopher P. , Berejikian Barry A. , Flagg Thomas A.
Published: December 2009

We quantified the aggression, feeding, dominance, position choice, and territory size of naturally reared steelhead Oncorhynchus mykiss fry stocked with two types of hatchery-reared fry (from conventional and enriched rearing environments) at two densities in experimental flumes to determine how rearing environment and fish density affect the behavior of steelhead fry. We found that fry density had a significant effect on most response variables but that rearing treatment did not. The rates of threats and attacks were positively correlated with fry density, but the overall feeding rate was negatively correlated. Naturally reared fry were dominant more often at low densities, and hatchery-reared fry were dominant more often at high densities. There were no significant effects of hatchery rearing treatment on aggression, feeding, dominance, or territory size. The only significant effect of rearing treatment was on the position of naturally reared fry, which occupied more upstream positions when stocked with conventional than with enriched hatchery-reared fry. Overall, rearing environment had relatively little influence on the behavior of steelhead fry. Our results indicate that stocking hatchery-reared steelhead fry at low densities may have effects on similar-size wild fish comparable to an equivalent increase in the density of wild fish. We suggest that releasing hatchery-reared steelhead fry as a supplementation strategy may have few direct negative ecological effects on wild fry.
Generalization of the Power Conservation Law for Scalar Mode-Diffraction Problems
Authors: Sirenko Yuriy , Petrusenko I. V.
Published: December 2009

A complete form of the generalized power conservation law for the problem of mode diffraction in the lossless multi-port H - ( E -) plane waveguide transformer has been obtained. The generalization has been accomplished by the use of the second Lorentz lemma in addition to the theorem of complex power. Some new equivalent forms of this law have been used to establish the fundamental properties of the scattering matrices. Operator matrix forms of the energy-conservation statement in the case of abrupt discontinuity are presented. The obtained results are intended for application in the analytic-numerical methods based on the modal analysis.
Regional Analytical Algorithm for Seawater Inherent Optical Properties Retrieving Using Reflectance Factors
Authors: Shybanov E. B. , Korchemkina E. N.
Published: December 2009

The applied method consists of solving of the inverse problem of marine bio-optics based on the sea reflectance spectrum. Non-standard parameterization of seawater optical properties is realized in the iterative algorithm. The condition of reflectance constancy at the wavelength of 400 nm is shown to stabilize the algorithm processing. Maps of chlorophyll concentration distribution are plotted for the South Coast of Crimea. The obtained concentration values are typical for Black Sea coastal regions in summer.
The electronic journal
Authors: Eisenberg Daniel
Published: December 2009

This screen-based scenario envisions a weekly national Chaucerian seminar and other permutations in traditional scholarly communication
Secure SGML: A Proposal to the Information Community
Authors: Maguire Mark
Published: December 2009

An inherent characteristic of electronic documents is the ease with which they can be transmitted, reproduced, and modified. The pervasive 'openness' of the digital revolution has raised serious concerns among authors and publishers, whose livelihood depends on controlled access to their works, as well as among librarians, who are responsible to their patrons for ensuring that works accessed through their systems can reliably be traced to their sources. New developments in cryptography combined with the features of Standard Generalized Markup Language may provide a solution that protects copyright without impeding access to information.
Using the Internet for Marketing: A Publisher's Secrets
Authors: Strangelove Michael
Published: December 2009

The Internet has become sufficiently accessible to publishers, authors, and purchasers of scholarly books and journals that no publisher can afford to ignore it as a vehicle for promotion, sales, and distribution. There are tools now available that make it possible to identify and reach target audiences directly, and using these tools need not be an expensive undertaking. Some practical tips are outlined here.
Specifications for Camera-Ready Copy: Helping Authors Be More Productive
Authors: Tibbo Helen R.
Published: December 2009

With thespreadof desktop publishing technology throughout colleges anduniversities, scholarly publishers are asking an increasing number of authors not only to write manuscripts, but also to provide camera-ready copy. In allbut the printing, binding, and distribution aspects, authors are indeed'publishing' today. Both publishers andauthors canbenefitfrom this arrangement. This article discusses the issues surroundingcamera-ready copyfromwhichpublishers candevise optimal guidelines. These suggestions also caninform authors aboutthenatureofthe camera-ready process.
The Scholar and the Art of Publishing
Authors: Rowson Richard C.
Published: December 2009

Authors looking to bepublished will benefit from an awareness of the qualities of good scholarship, an overview of the different types of publishing, and some knowledge of how to prepare a manuscript so that it will be more readily accepted by a prospective publisher. Once a manuscript has been accepted, author and publisher must work as a team, respecting each other's area of expertise.
Electronic Scholarship; or, Scholarly Publishing and the Public
Authors: Unsworth John
Published: December 2009

In order to understand the real importance of electronic scholarly editions, we must see electronic scholarship in its larger cultural context. Many in the academy resist the change introduced bynew technologies, a stance that serves the interests of those who would like to see the least possible alteration of the property system or the role of the consumer. This resistance is clearly voiced by academic Sven Birkerts, whose criticisms of the digital world foreground fear of depersonalization, inauthenticity, subjugation to the mechanical, and the substitution of quantity for quality. Electronic scholarly editions will alter the course of the academic profession, but will also open new opportunities for redefining scholarly inquiry and communication. Already, communication over the networks, in a variety of modes, enhances collaboration, connection, andinitiative. Primary materials are made available to a broader audience. Most important, we have an opportunity to alter how we, as scholars, structure our relation to the general public -although this restructuring, if it proceeds too slowly, may not produce a real difference.
Trends in Scientific Scholarly Journal Publishing in the United States
Authors: Tenopir Carol , King Donald W.
Published: December 2009

Scientific scholarly publishing has experienced dramatic economic change over the past few decades. Unfortunately, there has been little documentation concerning details of such change, other than reported price increases. In mid-I995 the University of Tennessee School of Information Sciences/Center for Information Studies was awarded the Special Libraries Association Steven 1. Goldspiel Memorial Research Grant. The purpose of this grantis to produce relevant data and information to examine the scholarly journal publishing system in order to better understand what has happened and to help authors, publishers, librarians, readers, and library funders avoid mistakes of the past when dealing with emerging electronic journals and article distribution. This paper describes current scientific journal publishing in the United States, trends over the past twenty years, and data that help explain the price and demand relationship involving individual and institutional subscriptions.
Gutenberg, the Scriptoria, and Websites
Authors: Zeigler John F. (zig)
Published: December 2009

The current publishing programs ofuniversity presses seem to be threatened by the Web; but this apparent threat is not unique to our own time, and it need not lead us to despair. Gutenberg's invention of printing from movable type and its early history provide a distant mirror. Rightly seen, our future promises to be an exciting one, offering us an opportunity to extend the literary franchise and expand our influence.
The Wave of the Present: The Printed Scholarly Journal and the Edge of the Internet
Authors: Tomlins Christopher L.
Published: December 2009

A senior editor reflects on his profession's purpose in the 'electronic era' and reminds us that contemporary editors have an obligation to respond to the rise of electronic publishing seriously and critically, just as scholarly editors earlier established and now maintain essential critical standards for professional scholarship. The functions editors perform are seen to have continuing value irrespective of the medium in which publications appear. The future of the editorial process is assured, because it is integral to the production of scholarship that can be trademarked as proficient and dependable. Lately, the discourse of proponents of online publishing has been moving towards precisely the same conclusion.
What Do the Readers Think? A Look at How Scientific Journal Users See the Electronic Environment
Authors: Pederson Sarah , Stockdale Rosemary
Published: December 2009

A study was conducted to assess how the average scientific journal reader, with little or no knowledge of electronic journal projects, viewed the electronic environment, and to gather information about these readers' reactions to the new environment. The study looked at patterns of journal use and examined whether the facilities that electronic journals offered were satisfying to the journal reader. It appears that more than a third of the surveyed scientific journal users do not read electronic journals, although a reasonable percentage of readers access more than five electronic journals on a regular basis. There is a broad consensus among the readers on the importance of the various facilities offered by publishers; readers' rating of importance is directly related to quick and easy access to a wide range of relevant, useful information.
Planning for Bus-on-Shoulders Operations in Northeastern Illinois
Authors: Metaxatos Paul , Thakuriah Piyushimita
Published: December 2009

Operating public buses on urban highway shoulders is a strategy being explored as a means to fight congestion and attract more riders to public transit. However, little information is available about the institutional and legal issues, project development process, costs, and performance of such operations. Results are presented of a study undertaken in northeastern Illinois to examine these preliminary but important issues, which must be addressed to the satisfaction of a diverse group of stakeholders. Findings from a survey of core stakeholders are reported. Concerns and possible resolutions that can be used to engage a larger group of stakeholders at a later time in the planning phase are documented.
Scheduling Buses to Take Advantage of Transit Signal Priority
Authors: Altun Selman Z. , Furth Peter G.
Published: December 2009

Transit signal priority can improve bus operations when it is applied to a route without making any changes to its route design or management; however, benefits can be greater if service design and management policies are purposely altered to take advantage of transit signal priority. Service design issues include generating carefully constructed schedules for use with conditional priority and deciding whether to locate stops on the near side or far side of intersections. Management issues include using conditional priority as a means to give priority only to late buses and deciding whether to hold buses at bus stops until a scheduled departure time, in case conditional priority itself does not offer the desired level of operational control. An optimal level of aggressiveness in the running time schedule is sought as a balance between mean running time with and without priority, assuming that priority will be conditional. With a more aggressive schedule, buses will be late and therefore will request (and get) priority more often; however, a more aggressive schedule also offers less slack to compensate for random delays. Analysis uses both a spreadsheet-based simulation model and a traffic microsimulation model that account for random delays at dispatch and at traffic signals, the effect of crowding on dwell time, and choice of priority and operational control tactics. It is found that optimal performance uses conditional priority and holding, but with an aggressive schedule, leading to substantial reductions in mean running time, standard deviation of running time, headway irregularity, and crowding.