bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation of alkanes by bacteria
Authors: Rojo Fernando 
Published: May 2009

SummaryPollution of soil and water environments by crude oil has been, and is still today, an important problem. Crude oil is a complex mixture of thousands of compounds. Among them, alkanes constitute the major fraction. Alkanes are saturated hydrocarbons of different sizes and structures. Although they are chemically very inert, most of them can be efficiently degraded by several microorganisms. This review summarizes current knowledge on how microorganisms degrade alkanes, focusing on the biochemical pathways used and on how the expression of pathway genes is regulated and integrated within cell physiology.
Social Representations of Retirement in France: A Descriptive Study
Authors: Roland‐Lévy Christine , Berjot Sophie 
Published: May 2009

The social representations of three social groups (students, people in the workforce, and retirees) are investigated. Comparison of the three samples allows one to describe how social representations of retirement differ according to age and employment status. It can be noted that both students and adults who are still working share some core elements in their representation of retirement, which is mainly perceived as a well‐deserved time to rest. However, the central nucleus of those people who have recently retired excludes this idea of needing some time to rest and centers more around having less stress, and more freedom; the end of work might mean undesired inactivity.Les représentations sociales de la retraite de trois groupes sociaux (étudiants, individus issus de la population active et retraités) sont étudiées. La comparaison entre les trois échantillons permet de décrire comment les représentations sociales de la retraite diffèrent selon l'âge et le statut du sujet. On a pu noter que les étudiants et les adultes en activité partagent quelques éléments centraux de leur représentation sociale de la retraite, qui est essentiellement perçue comme un temps de repos bien mérité. Cependant, le noyau central des personnes récemment retraitées ne contient pas cette idée d'un besoin d'un temps de repos et se centre plus sur le fait d'être moins stressé et d'avoir plus de liberté; la fin du travail pourrait alors signifier une inactivité non désirée.
Naïve Diversification in the Swedish Premium Pension Scheme: Experimental Evidence
Authors: Hedesström Ted Martin , Svedsäter Henrik , Gärling Tommy 
Published: May 2009

In the Swedish Premium Pension Scheme (PPS) all citizens in paid employment allocate part of their public pension savings to mutual funds. In so doing they tend to distribute their choices maximally across different stock fund categories. It is hypothesised that this reflects the naïve application of a variety‐inducing diversification heuristic. The results of two experiments simulating choices of fund categories in the PPS support this hypothesis by showing that participating undergraduates chose stock funds investing in overlapping and non‐overlapping markets or industries in a way demonstrating failure to take into account covariation among fund returns. Administrators of the PPS and similar defined‐contribution pension plans should provide participants with comprehensive advice on how to diversify their investment.Dans le régime de retraite suédois (PPS), tous les citoyens ayant un emploi salarié allouent une part de l'épargne de leur retraite publique à des fonds d'investissements. Ce faisant, ils tendent majoritairement à répartir leurs choix dans différentes catégories de fonds. On a fait l'hypothèse que cela reflète l'application naïve d'une heuristique de la diversification. Les résultats de deux expérimentations simulant des choix entre différentes catégories de fonds pour le PPS confirment cette hypothèse : les sujets (étudiants) ont choisi des fonds en actions et devaient investir sur des marchés ou dans des branches industrielles relevant ou non du même secteur économique et cela d'une façon qui mettait en évidence leur incapacitéà prendre en considération le fait que le retour sur investissement de différents fonds pouvait être lié. Les administrateurs du PPS et de plans de pensions avec versements programmés devraient fournir aux participants des conseils avisés sur la façon de diversifier leur investissement.
Entrepreneurship and Risk Taking
Authors: Macko Anna , Tyszka Tadeusz 
Published: May 2009

According to the definition of entrepreneurship and everyday observation, entrepreneurs are perceived as more risk prone than other people. However, laboratory studies do not provide conclusive support for this claim. In our study, three groups of students served as subjects. One group of students did not express any intention of starting up their own business in the near future. The second group consisted of students who had participated in a special course designed for future entrepreneurs. The third group consisted of students or alumni who became entrepreneurs before graduating. In accordance with Knight's claim, we found that actual entrepreneurs revealed the highest, and students who did not express an intention of starting their own business the lowest, level of self‐confidence of all groups participating in the experiment. On the other hand, in well‐defined risky situations we did not confirm a hypothesis that would‐be entrepreneurs or actual entrepreneurs were more risk prone than students with no intention of starting a business. Yet, in naturalistic‐business risky situations we found more risky choices among entrepreneurs than among non‐entrepreneurs.Conformément à la définition même de l'esprit d'entreprise et à l'observation quotidienne, les entrepreneurs sont perçus comme étant plus enclins que les autres personnes à prendre des risques. Seulement, les recherches expérimentales ne confirment pas de façon définitive cette conception. Notre étude a porté sur trois groupes d'étudiants. L'un des groupes n'avait aucunement l'intention de créer une entreprise dans un avenir prévisible. Le deuxième groupe était composé d'étudiants qui suivaient un cours spécialement destiné aux futurs entrepreneurs. Le troisième groupe rassemblait des étudiants ou d'anciens étudiants qui devinrent entrepreneurs avant d'être diplômés. En accord avec les propositions de Knight, on a constaté que les entrepreneurs étaient ceux qui avaient la plus forte confiance en eux‐mêmes et les jeunes qui n'éprouvaient aucune vocation d'entrepreneur la plus faible. D'autre part, face à des situations de risque bien précises, il fut impossible de corroborer l'hypothèse que les aspirants entrepreneurs ou les chefs d'entreprise étaient plus portés sur le risque que les étudiants n'ayant aucunement l'intention de fonder une entreprise. Toutefois, devant des décisions risquées dans des situations concrètes industrielles ou commerciales, on a observé plus de choix aventureux chez les entrepreneurs que chez ceux qui ne l'étaient pas.
Effort and Aspirations in Tax Evasion: Experimental Evidence
Authors: Kirchler Erich , Muehlbacher Stephan , Hoelzl Erik , Webley Paul 
Published: May 2009

Is the effort exerted to earn taxable income considered in compliance decisions? And if so, is hard‐earned income or easy money more likely to be concealed from authorities? While economic theory postulates that prior costs should not affect present decisions, psychological research shows that prior investments of money, time, or effort do matter. Findings from previous studies on the impact of effort on abstract decision tasks suggest two contradictory predictions for the context of tax compliance decisions: Either taxable income earned by high effort is subjectively of higher value, and therefore more likely to be evaded, or investments of effort cause a shift of the reference point through the establishment of an aspiration level, resulting in honest declaration of income. Two experiments were conducted to test these predictions. In a business simulation, taxable income was obtained by different levels of effort and consequently had to be reported to authorities. Results show that tax evasion was more pronounced in low‐effort conditions. This suggests that effort changes the reference point rather than the slope, and provides evidence that in tax compliance decisions aspiration levels serve as reference points. Implications for tax audits are discussed.L'effort déployé pour obtenir des revenus imposables est‐il pris en compte dans les décisions qui en découlent? Et si c'est le cas, est‐ce l'argent facile ou les revenus durement gagnés qui présentent une plus forte probabilité d'être soustraits au fisc? Alors que la théorie économique postule que le coût antérieur n'a pas de retombées sur les décisions présentes, les recherches de psychologie montrent que les investissements passés en argent, temps ou effort ont leur importance. Des travaux sur l'impact de l'effort sur des tâches de décision abstraite débouchent sur deux prédictions contradictoires en ce qui concerne les décisions relatives à l'impôt: ou le revenu imposable obtenu à la suite d'un effort substantiel est subjectivement fortement valorisé et a de fortes chances d'être camouflé, ou l'effort investi provoque un changement de référence à travers l'instauration d'un niveau d'aspiration, ce qui a pour conséquence une déclaration honnête des revenus. On a réalisé deux expériences pour mettre à l'épreuve ces prédictions. Dans une simulation commerciale, le revenu imposable a été obtenu suite à différents niveaux d'effort et devait être portéà la connaissance du fisc. Les résultats montrent que l'évasion fiscale était plus accentuée dans les conditions où l'effort était modeste. Il faut en conclure que l'effort entraîne une mutation du système de référence plutôt qu'une simple modification de niveau et que dans les décisions relatives à l'impôt les niveaux d'aspiration servent de point de référence. On réfléchit aux leçons à en tirer pour le contrôle fiscal.
Sequence learning in infancy: the independent contributions of conditional probability and pair frequency information
Authors: Marcovitch Stuart , Lewkowicz David J. 
Published: May 2009

AbstractThe ability to perceive sequences is fundamental to cognition. Previous studies have shown that infants can learn visual sequences as early as 2 months of age and it has been suggested that this ability is mediated by sensitivity to conditional probability information. Typically, conditional probability information has covaried with frequency information in these studies, raising the possibility that each type of information may have contributed independently to sequence learning. The current study explicitly investigated the independent contribution of each type of information. We habituated 2.5‐, 4.5‐, and 8.5‐month‐old infants to a sequence of looming visual shapes whose ordering was defined independently by specific conditional probability relations among pair elements and by the frequency of occurrence of such pairs. During test trials, we tested infants’ sensitivity to each type of information and found that both types of information independently influenced sequence learning by 4.5 months of age.
Change of reference frame for tactile localization during child development
Authors: Pagel Birthe , Heed Tobias , Röder Brigitte 
Published: May 2009

AbstractTemporal order judgements (TOJ) for two tactile stimuli, one presented to the left and one to the right hand, are less precise when the hands are crossed over the midline than when the hands are uncrossed. This ‘crossed hand’ effect has been considered as evidence for a remapping of tactile input into an external reference frame. Since late, but not early, blind individuals show such remapping, it has been hypothesized that the use of an external reference frame develops during childhood. Five‐ to 10‐year‐old children were therefore tested with the tactile TOJ task, both with uncrossed and crossed hands. Overall performance in the TOJ task improved with age. While children older than 5½ years displayed a crossed hand effect, younger children did not. Therefore the use of an external reference frame for tactile, and possibly multisensory, localization seems to be acquired at age 5.
What happens to translocated game birds that ‘disappear’?
Authors: Dickens M. J. , Delehanty D. J. , Reed J. M. , Romero L. M. 
Published: May 2009

AbstractThe ultimate goal of most translocation efforts is to create a self‐sustaining wild population of a species deliberately moved from one part of their range to another. As follow‐up of a translocation attempt is often difficult, causes for failure are relatively unknown. Dispersal away from the release site is one potential source of failure because it decreases the likelihood of the released population establishing itself post‐translocation. In this study, we used chukar Alectoris chukar as a surrogate for translocated game birds in order to conduct a large‐scale experimental study. We observed that these desert‐adapted birds demonstrate a strong fidelity for specific water sources. We also report the propensity for the translocated individuals to either disperse and return to their original water source site or remain at the release site. During two field seasons, we observed opposing behaviors such that the proportion of individuals returning to the capture site, versus those remaining at the release site, shifted between years. We analyzed this change between the years as well as within the years to assess the potential underlying causes such as translocated distance, differences in rainfall between seasons and water source type. We concluded that homing behavior was strong in this non‐migratory bird species and that strength of this homing behavior varied, potentially due to conditions surrounding the limiting resource, water availability. The large‐scale, original data presented here may help to explain why some releases result in a successfully established population while other releases result in widely dispersed individuals.
Insulin and the IGF system in the human placenta of normal and diabetic pregnancies
Authors: Hiden Ursula , Glitzner Elisabeth , Hartmann Michaele , Desoye Gernot 
Published: May 2009

AbstractThe insulin/insulin‐like growth factor (IGF) system regulates fetal and placental growth and development. In maternal diabetes, components of this system including insulin, IGF1, IGF2 and various IGF‐binding proteins are deregulated in the maternal or fetal circulation, or in the placenta. The placenta expresses considerable amounts of insulin and IGF1 receptors at distinct locations on both placental surfaces. This makes the insulin and the IGF1 receptor accessible to fetal and/or maternal insulin, IGF1 and IGF2. Unlike the receptor for IGF1, the insulin receptor undergoes a gestational change in expression site from the trophoblast at the beginning of pregnancy to the endothelium at term. Insulin and IGFs are implicated in the receptor‐mediated regulation of placental growth and transport, trophoblast invasion and placental angiogenesis. The dysregulation of the growth factors and their receptors may be involved in placental and fetal changes observed in diabetes, i.e. enhanced placental and fetal growth, placental hypervascularization and higher levels of fetal plasma amino acids.
Hypoxia inducible factor (HIF)‐2α is required for the development of the catecholaminergic phenotype of sympathoadrenal cells
Authors: Brown Stephen T. , Kelly Kevin F. , Daniel Juliet M. , Nurse Colin A. 
Published: May 2009

AbstractThe basic helix‐loop‐helix transcription factor, hypoxia inducible factor (HIF)‐2α has been implicated in the development of the catecholaminergic phenotype in cells of the sympathoadrenal (SA) lineage; however, the underlying mechanisms and HIF‐2α targets remain unclear. Using an immortalized rat adrenomedullary chromaffin cell line (MAH cells) derived from a fetal SA progenitor, we examined the role of HIF‐2α in catecholamine biosynthesis. Chronic hypoxia (2% O2, 24 h) induced HIF‐2α in MAH cells but expression of the rate‐limiting enzyme, tyrosine hydroxylase (TH) and catecholamine levels were unaltered. Interestingly, HIF‐2α depleted MAH cells showed dramatically lower (5–12 times) levels of dopamine and noradrenaline compared with wild‐type and scrambled controls, even in normoxia (21% O2). This was correlated with a marked reduction in the expression of DOPA decarboxylase (DDC) and dopamine β hydroxylase (DβH) but not TH. Chromatin immunoprecipitation assays revealed that HIF‐2α was bound to the DDC gene promoter which contains two putative hypoxia response elements. These data suggest that a basal level of HIF‐2α function is required for the normal developmental expression of DDC and DβH in SA progenitor cells, and that loss of this function leads to impaired catecholamine biosynthesis.
Inhibition of EGF‐induced ERK/MAP kinase‐mediated astrocyte proliferation by μ opioids: integration of G protein and β‐arrestin 2‐dependent pathways
Authors: Miyatake Mayumi , Rubinstein Tal J. , McLennan Gregory P. , Belcheva Mariana M. , Coscia Carmine J. 
Published: May 2009

AbstractAlthough μ, κ, and δ opioids activate extracellular signal‐regulated kinase (ERK)/mitogen‐activated protein (MAP) kinase, the mechanisms involved in their signaling pathways and the cellular responses that ensue differ. Here we focused on the mechanisms by which μ opioids rapidly (min) activate ERK and their slower (h) actions to inhibit epidermal growth factor (EGF)‐induced ERK‐mediated astrocyte proliferation. The μ‐opioid agonists ([d‐ala2, mephe4, gly‐ol5] enkephalin and morphine) promoted the phosphorylation of ERK/MAP kinase within 5 min via Gi/o protein, calmodulin (CaM), and β‐arrestin2‐dependent signaling pathways in immortalized and primary astrocytes. This was based on the attenuation of the μ‐opioid activation of ERK by pertussis toxin (PTX), the CaM antagonist, W‐7, and siRNA silencing of β‐arrestin2. All three pathways were shown to activate ERK via an EGF receptor transactivation‐mediated mechanism. This was disclosed by abolishment of μ‐opioid‐induced ERK phosphorylation with the EGF receptor‐specific tyrosine phosphorylation inhibitor, AG1478, and μ‐opioid‐induced reduction of EGF receptor tyrosine phosphorylation by PTX, and β‐arrestin2 targeting siRNA in the present studies and formerly by CaM antisense. Long‐term (h) treatment of primary astrocytes with [d‐ala2,mephe4,gly‐ol5] enkephalin or morphine, attenuated EGF‐induced ERK phosphorylation and proliferation (as measured by 5′‐bromo‐2′‐deoxy‐uridine labeling). PTX and β‐arrestin2 siRNA but not W‐7 reversed the μ‐opioid inhibition. Unexpectedly, β‐arrestin‐2 siRNA diminished both EGF‐induced ERK activation and primary astrocyte proliferation suggesting that this adaptor protein plays a novel role in EGF signaling as well as in the opioid receptor phase of this pathway. The results lend insight into the integration of the different μ‐opioid signaling pathways to ERK and their cellular responses.
The timing of eclogite facies metamorphism and migmatization in the Orlica–Śnieżnik complex, Bohemian Massif: constraints from a multimethod geochronological study
Authors: BRÖCKER M. , KLEMD R. , COSCA M. , BROCK W. , LARIONOV A. N. , RODIONOV N. 
Published: May 2009

AbstractThe Orlica–Śnieżnik complex (OSC) is a key geological element of the eastern Variscides and mainly consists of amphibolite facies orthogneisses and metasedimentary rocks. Sporadic occurrences of eclogites and granulites record high‐pressure (HP) to ultrahigh‐pressure (UHP) metamorphic conditions. A multimethod geochronological approach (40Ar–39Ar, Rb–Sr, Sm–Nd, U–Pb) has been used to gain further insights into the polymetamorphic evolution of eclogites and associated country rocks. Special attention was given to the unresolved significance of a 370‐ to 360 Ma age group that was repeatedly described in previous studies. Efforts to verify the accuracy ofc.370 Ma K–Ar phengite and biotite dates reported for an eclogite and associated country‐rock gneiss from the location Nowa Wieś suggest that these dates are meaningless, due to contamination with extraneous Ar. Extraneous Ar is also considered to be responsible for a significantly older40Ar–39Ar phengite date ofc.455 Ma for an eclogite from the location Wojtowka. Attempts to further substantiate the importance of 370–360 Ma zircon dates as an indicator for a melt‐forming high‐temperature (HT) episode did not provide evidence in support of anatectic processes at this time. Instead, SHRIMP U–Pb zircon dating of leucosomes and leucocratic veins within both orthogneisses and (U)HP granulites revealed two age populations (490–450 and 345–330 Ma respectively) that correspond to protolith ages of the magmatic precursors and late Variscan anatexis. The results of this study further underline the importance of Late Carboniferous metamorphic processes for the evolution of the OSC that comprise the waning stages of HP metamorphism and lower pressure HT overprinting with partial melting. Eclogites and their country rocks provided no chronometric evidence for an UHP and ultrahigh‐temperature episode at 387–360 Ma, as recently suggested for granulites from the OSC, based on Lu–Hf garnet ages (Anczkiewiczet al., 2007).
The Impact of Diabetes Mellitus on Two‐Year Mortality Following Contemporary Percutaneous Coronary Intervention: Implications for Revascularization Practice
Authors: ANDRON M. , PERRY R. A. , EGRED M. , ALAHMAR A. E. , GRAYSON A. D. , SHAW M. , ROBERTS E. , PALMER N. D. , STABLES R. H. 
Published: May 2009

Objective:

To assess the impact of diabetes on 2‐year mortality in current PCI practice.
Background:

In patients with coronary artery disease undergoing revascularization, diabetes mellitus is associated with higher mortality.
Methods:

A retrospective analysis was done of all patients undergoing PCI at our tertiary center between January 2000 and December 2004. There were 6,160 PCI procedures performed in 5,759 patients who received at least one stent. Of these patients, 801 (13.9%) were diabetic and 4,958 (86.1%) were nondiabetic. The primary outcome measure of the study was all‐cause mortality. All patients were followed up for a period of 2 years. Multivariate logistic regression analysis was used to test for a potential independent association between diabetic status and follow‐up mortality.
Results:

Before adjustment, a trend toward higher mortality was observed in diabetic patients compared to non‐diabetics at 1 year (3.2% vs 2.4%) and 2 years (5.1% vs 3.8%), P = 0.12. Independent predictors for mortality were increasing age, renal dysfunction, peripheral vascular disease, NYHA class >2, urgent PCI, treating left main stem lesions, vessel diameter ≤ 2.5 mm, and 3‐vessel disease. The use of drug‐eluting stent was associated with a reduction in mortality. Diabetes was found to have no independent impact on mortality following PCI (odds ratio = 1.08; 95% confidence intervals = 0.73–1.60; P = 0.71).
Conclusion:

The presence of diabetes was not an independent predictor of mortality following PCI. A diabetic patient that does not require insulin treatment and has no evidence of macro‐ or microvascular diabetic disease could enjoy a PCI outcome similar to nondiabetic subjects.