bluuebunny/crossref_metadata_2025 huggingface dataset:
Who Picks Psychiatry? Perceptions, Preferences and Personality of Medical Students
Authors: Malhi Gin S. , Coulston Carissa M. , Parker Gordon B. , Cashman Emma , Walter Garry , Lampe Lisa A. , Vollmer-Conna Ute
Published: September 2011

Objectives: This study aimed to characterise the personality profiles of junior medical students most likely to choose psychiatry as a career, determine aspects of psychiatry that most attract potential recruits, and identify misperceptions about psychiatry that may dissuade students from pursuing this specialism.

Method: A total of 580 second-year medical students from the University of New South Wales, Australia completed a set of questionnaires that measured the likelihood with which various medical specialties were being considered as careers, personality traits using the NEO Five-Factor Inventory (NEO-FFI), and the degree to which students perceived each specialty as attractive across a number of parameters.

Results: Only 86 students (15%) indicated a strong likelihood of choosing psychiatry, compared to other specialties which attracted higher proportions of students (range 19–49%). These 86 students had significantly higher openness scores than those who indicated a lesser likelihood of pursuing psychiatry. Students who were highly interested in psychiatry ranked it as very attractive in respect to providing interesting and challenging subject matter, and relatively attractive in respect to financial reward, work enjoyment, good lifestyle, having a bright and interesting future, and association with colleagues. However, psychiatry remained less attractive with respect to prestige, perceived low effectiveness of treatments, degree to which it draws upon aspects of medical training, and lack of reliable scientific foundation. Within the entire sample, psychiatry was ranked most unattractive compared to the other specialties across eight of the 13 parameters assessed.

Conclusions: Students interested in psychiatry are more likely to be ‘open’ and view the specialty as interesting and challenging. Such characteristics should be promoted more widely along with countering myths that as a specialty, psychiatry lacks a scientific foundation or is somehow different from mainstream medicine in terms of training and outcomes. Championing psychiatry in this manner may attract more recruits and enhance its prestige.
Peak Period Use of I-15 Corridor in San Diego, California
Authors: Borrell-Rovira Anna , Supernak Janusz
Published: September 2011

The results of the 1998 to 2008 peak period monitoring of a 8-mi FasTrak section of Interstate 15 (I-15) in San Diego, California, are reported in this paper. The paper examines changes in peak period utilization and volume distribution throughout the peak with the emphasis on the level of service (LOS) offered on both high-occupancy toll (HOT) lanes and the main lanes of I-15. The study revealed that the peak period volumes on the HOT lanes (both FasTrak and carpool) strongly depend on the LOS deficit on the main lanes. Carpool participation was not hurt by the growing FasTrak volumes. The law-mandated LOS C was effectively protected by the dynamic pricing mechanism on the HOT lanes. The Congestion Pricing Project in San Diego proved able to redistribute a portion of the peak period volumes on the HOT lanes from the middle of the peak to its shoulders and now plays an important role in improving operation of the entire I-15 corridor.
Congestion Pricing Study of San Francisco–Oakland Bay Bridge in California
Authors: Zhang Lin , Du Haining , Lee Linda
Published: September 2011

The San Francisco–Oakland Bay Bridge in California is one of the most heavily traveled corridors in the United States. A study on congestion pricing was performed to address traffic congestion in this corridor. Existing toll plaza counts and travel time data were used in the estimation of traffic demand by applying queuing analysis. Regression analysis was conducted to estimate the number of drivers who would shift to other modes in response to the congestion pricing. Five congestion pricing alternatives were examined. The bigger the price differential between peak and nonpeak toll, the more delays, queue length, and duration of congestion were reduced. Of the five alternatives, the one with a $2.00 price differential between peak and nonpeak toll was selected and implemented on July 1, 2010. This adopted congestion pricing strategy was to reduce the traffic demand by 4.2% and 5.0% in the a.m. and p.m. peak periods, respectively. The congestion pricing was to reduce significant delays (24% to 30%) by removing only a fraction of the vehicles (4.2% to 5.0%) from the congested Bay Bridge. A preliminary analysis comparing traffic counts between July and September 2009 and July and September 2010 found that, in July, traffic volume decreased by 8.4% and 7.3% during the a.m. and p.m. peak periods, respectively. In September, traffic volume decreased by 6.0% and 3.9% during the a.m. and p.m. peak periods, respectively. A comprehensive evaluation study is under way to identify changes due to congestion pricing and changes due to a multitude of exogenous factors.
Impact of admission month and hospital teaching status on outcomes in subarachnoid hemorrhage: evidence against the July effect
Authors: McDonald Robert J. , Cloft Harry J. , Kallmes David F.
Published: September 2011

Object

The authors sought to identify the presence of a “July effect,” a transient increase in adverse outcomes during July, among a cohort of spontaneous subarachnoid hemorrhage (SAH) admissions recorded in the National Inpatient Sample (NIS).

Methods

The discharge status, admission month, patient demographics, treatment parameters, and hospital characteristics among spontaneous SAH admissions were extracted from the 2001–2008 NIS. Multivariate regression was used to determine whether an unfavorable discharge status and/or in-hospital mortality significantly increased in summer months in a pattern suggestive of a July effect. Additional models were generated to assess the impact of hospital teaching status on these outcomes.

Results

Among 57,663,486 hospital admissions from the 2001–2008 NIS, 52,879 cases of spontaneous SAH (ICD-9-CM 430) were treated at teaching (36,914 cases [70%]) and nonteaching (15,965 cases [30%]) facilities. Regression models failed to reveal a July effect for in-hospital mortality (χ2 = 0.75, p = 1.000) or unfavorable discharges (χ2 = 1.69, p = 0.999) among monthly SAH admissions, although they did suggest a significant reduction in these outcomes (in-hospital mortality, OR = 0.89, p < 0.001; unfavorable discharges, OR = 0.88, p < 0.001) among teaching hospitals as compared with nonteaching hospitals after adjustment for disparities in demographic, treatment, and hospital characteristics.

Conclusions

The discharge disposition among SAH admissions within the NIS was not suggestive of a July effect but did reveal that teaching institutions have significantly lower rates of adverse outcomes when compared with nonteaching hospitals. Note, however, that the origins of this difference related to teaching status remain unclear.
Chelation in Metal Intoxication
Authors: Flora Swaran J.S. , Pachauri Vidhu
Published: September 2011

Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents) or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.
Analysis of Technological Innovation and Environmental Performance Improvement in Aviation Sector
Authors: Lee Joosung , Mo Jeonghoon
Published: September 2011

The past oil crises have caused dramatic improvements in fuel efficiency in all industrial sectors. The aviation sector—aircraft manufacturers and airlines—has also made significant efforts to improve the fuel efficiency through more advanced jet engines, high-lift wing designs, and lighter airframe materials. However, the innovations in energy-saving aircraft technologies do not coincide with the oil crisis periods. The largest improvement in aircraft fuel efficiency took place in the 1960s while the high oil prices in the 1970s and on did not induce manufacturers or airlines to achieve a faster rate of innovation. In this paper, we employ a historical analysis to examine the socio-economic reasons behind the relatively slow technological innovation in aircraft fuel efficiency over the last 40 years. Based on the industry and passenger behaviors studied and prospects for alternative fuel options, this paper offers insights for the aviation sector to shift toward more sustainable technological options in the medium term. Second-generation biofuels could be the feasible option with a meaningful reduction in aviation’s lifecycle environmental impact if they can achieve sufficient economies of scale.
Sirt3, Mitochondrial ROS, Ageing, and Carcinogenesis
Authors: Park Seong-Hoon , Ozden Ozkan , Jiang Haiyan , Cha Yong I. , Pennington J. Daniel , Aykin-Burns Nukhet , Spitz Douglas R. , Gius David , Kim Hyun-Seok
Published: September 2011

One fundamental observation in cancer etiology is that the rate of malignancies in any mammalian population increases exponentially as a function of age, suggesting a mechanistic link between the cellular processes governing longevity and carcinogenesis. In addition, it is well established that aberrations in mitochondrial metabolism, as measured by increased reactive oxygen species (ROS), are observed in both aging and cancer. In this regard, genes that impact upon longevity have recently been characterized in S. cerevisiae and C. elegans, and the human homologs include the Sirtuin family of protein deacetylases. Interestingly, three of the seven sirtuin proteins are localized into the mitochondria suggesting a connection between the mitochondrial sirtuins, the free radical theory of aging, and carcinogenesis. Based on these results it has been hypothesized that Sirt3 functions as a mitochondrial fidelity protein whose function governs both aging and carcinogenesis by modulating ROS metabolism. Sirt3 has also now been identified as a genomically expressed, mitochondrial localized tumor suppressor and this review will outline potential relationships between mitochondrial ROS/superoxide levels, aging, and cell phenotypes permissive for estrogen and progesterone receptor positive breast carcinogenesis.
Optimization of Phenolic Antioxidant Extraction from Wuweizi (Schisandra chinensis) Pulp Using Random-Centroid Optimazation Methodology
Authors: Wu Xia , Yu Xiong , Jing Hao
Published: September 2011

The extraction optimization and composition analysis of polyphenols in the fresh pulp of Wuweizi (Schisandra chinensis) have been investigated in this study. The extraction process of polyphenols from Wuweizi pulp was optimized using Random-Centroid Optimization (RCO) methodology. Six factors including liquid and solid ratio, ethanol concentration, pH, temperature, heating time and extraction times, and three extraction targets of polyphenol content, antioxidant activity and extract yield were considered in the RCO program. Three sets of optimum proposed factor values were obtained corresponding to three extraction targets respectively. The set of optimum proposed factor values for polyphenol extraction given was chosen in further experiments as following: liquid and solid ratio (v/w) 8, ethanol 67.3% (v/v), initial pH 1.75, temperature 55 °C for 4 h and extraction repeated for 4 times. The Wuweizi polyphenol extract (WPE) was obtained with a yield of 16.37 mg/g and composition of polyphenols 1.847 mg/g, anthocyanins 0.179 mg/g, sugar 9.573 mg/g and protein 0.327 mg/g. The WPE demonstrated high scavenging activities against DPPH radicals.
Nanoparticles and Neurotoxicity
Authors: Win-Shwe Tin-Tin , Fujimaki Hidekazu
Published: September 2011

Humans are exposed to nanoparticles (NPs; diameter < 100 nm) from ambient air and certain workplaces. There are two main types of NPs; combustion-derived NPs (e.g., particulate matters, diesel exhaust particles, welding fumes) and manufactured or engineered NPs (e.g., titanium dioxide, carbon black, carbon nanotubes, silver, zinc oxide, copper oxide). Recently, there have been increasing reports indicating that inhaled NPs can reach the brain and may be associated with neurodegeneration. It is necessary to evaluate the potential toxic effects of NPs on brain because most of the neurobehavioral disorders may be of environmental origin. This review highlights studies on both combustion-derived NP- and manufactured or engineered NP-induced neuroinflammation, oxidative stress, and gene expression, as well as the possible mechanism of these effects in animal models and in humans.
Cerebrospinal Fluid Markers in Sporadic Creutzfeldt-Jakob Disease
Authors: Zanusso Gianluigi , Fiorini Michele , Ferrari Sergio , Gajofatto Alberto , Cagnin Annachiara , Galassi Andrea , Richelli Silvia , Monaco Salvatore
Published: September 2011

Sporadic Creutzfeldt-Jakob disease (sCJD) is the commonest form of human prion diseases, accounting for about 85% of all cases. Current criteria for intra vitam diagnosis include a distinct phenotype, periodic sharp and slow-wave complexes at electroencephalography (EEG), and a positive 14-3-3-protein assay in the cerebrospinal fluid (CSF). In sCJD, the disease phenotype may vary, depending upon the genotype at codon 129 of the prion protein gene (PRNP), a site of a common methionine/valine polymorphism, and two distinct conformers of the pathological prion protein. Based on the combination of these molecular determinants, six different sCJD subtypes are recognized, each with distinctive clinical and pathologic phenotypes. We analyzed CSF samples from 127 subjects with definite sCJD to assess the diagnostic value of 14-3-3 protein, total tau protein, phosphorylated181 tau, and amyloid beta (Aβ) peptide 1-42, either alone or in combination. While the 14-3-3 assay and tau protein levels were the most sensitive indicators of sCJD, the highest sensitivity, specificity and positive predictive value were obtained when all the above markers were combined. The latter approach also allowed a reliable differential diagnosis with other neurodegenerative dementias.
Improving Protein Crystal Quality by the Without-Oil Microbatch Method: Crystallization and Preliminary X-ray Diffraction Analysis of Glutathione Synthetase from Pseudoalteromonas haloplanktis
Authors: Merlino Antonello , Krauss Irene Russo , Albino Antonella , Pica Andrea , Vergara Alessandro , Masullo Mariorosario , Vendittis Emmanuele De , Sica Filomena
Published: September 2011

Glutathione synthetases catalyze the ATP-dependent synthesis of glutathione from L-γ-glutamyl-L-cysteine and glycine. Although these enzymes have been sequenced and characterized from a variety of biological sources, their exact catalytic mechanism is not fully understood and nothing is known about their adaptation at extremophilic environments. Glutathione synthetase from the Antarctic eubacterium Pseudoalteromonas haloplanktis (PhGshB) has been expressed, purified and successfully crystallized. An overall improvement of the crystal quality has been obtained by adapting the crystal growth conditions found with vapor diffusion experiments to the without-oil microbatch method. The best crystals of PhGshB diffract to 2.34 Å resolution and belong to space group P212121, with unit-cell parameters a = 83.28 Å, b = 119.88 Å, c = 159.82 Å. Refinement of the model, obtained using phases derived from the structure of the same enzyme from Escherichia coli by molecular replacement, is in progress. The structural determination will provide the first structural characterization of a psychrophilic glutathione synthetase reported to date.
The Importance of Institutional Asymmetries to the Development of Binational Aquifer Assessment Programs: The Arizona-Sonora Experience
Authors: Megdal Sharon B. , Scott Christopher A.
Published: September 2011

Setting water policy depends fundamentally on the location of the supply and demand for water and the legal/institutional framework for water management. Within and across nations, laws and structures for water management decision making vary, often significantly. Recognizing these differences can aid in overcoming challenges inherent to the assessment and management of transboundary waters. This paper examines current binational efforts to develop the scientific information to support water management decision making along the United States-Mexico border. The particular focus is on transboundary aquifers along the border shared by the states of Arizona in the United States and Sonora in Mexico. Legislation enacted in the United States (Public Law 109–448) established a governmental-academic partnership to assess transboundary aquifers. The paper discusses the establishment of a working partnership between Mexico and the United States, which led to an official binational cooperative framework for transboundary assessment. It explains how the extensive effort to recognize and accommodate asymmetries in the underlying legal and regulatory frameworks for water management was essential to meeting the objectives of both countries. The focus of the binational investigations is briefly discussed. The paper concludes by noting the opportunities for additional cross-border scientific and water management collaboration should funding and institutional commitments continue.
Differences in spatial distribution, morphology, and communities of herbivorous insects among three cytotypes of Solidago altissima (Asteraceae)
Authors: Richardson Matthew L. , Hanks Lawrence M.
Published: September 2011

• Premise of the Study: Polyploidy in plants can result in genetic isolation, ecological differences among cytotypes, and, ultimately, speciation. Cytotypes should be sympatric only if they are segregated in an ecological niche or through prezygotic isolation. We tested whether sympatric diploid, tetraploid, and hexaploid ramets of Solidago altissima L. (Asteraceae) differ in their ecological niche.

• Methods: We measured how cytotypes were distributed within habitats, their morphology, and the composition of their communities of herbivorous insects at 10 natural field sites. We also conducted a common garden experiment to confirm whether observed differences in morphology or communities of herbivores were due to cytotype or environmental effects.

• Key Results: Diploid ramets often grew in open areas, relatively far from woody plants, and were associated with a high species richness of herbaceous plants, especially grasses. Hexaploids often grew in heavy shading under woody plants where grasses were scarce. Finally, tetraploids usually grew in transition areas between diploids and hexaploids. Hexaploid ramets also were taller than ramets of the other cytotypes and had larger leaves. Two species of insects, the leaf‐galling fly Asteromyia carbonifera and the phloem‐tapping aphid Uroleucon nigrotuberculatum, were more abundant on hexaploid ramets than on ramets of other cytotypes in the field. When grown in a common garden, however, cytotypes were similar in morphology and communities of herbivores.

• Conclusions: We conclude that cytotypes of S. altissima differ in their spatial distribution within habitats and that spatial variation in environmental factors influence plant morphology and communities of herbivorous insects.
The same but different: Monomorphic microsatellite markers as a new tool for genetic analysis
Authors: Nazareno Alison G. , Reis Mauricio S. dos
Published: September 2011

• Premise of the study: The nucleotide variation at a microsatellite locus lacking length polymorphisms among its alleles was assessed to generate an informative tool for genetic analysis.

• Methods and Results: From a set of microsatellite markers, a monomorphic microsatellite locus developed for the palm species Butia eriospatha was used to elucidate whether there are polymorphic sites in its flanking regions. DNA sequences ≈133 bp long were obtained. Aligned sequences show variation at 17 polymorphic sites with both insertions and nucleotide substitutions. Fourteen distinct sequences (alleles) among 22 individuals were identified. The percent sequence difference varied from 0.0 to 5%, indicating that there is significant variation among sequences.

• Conclusions: Due to significant levels of information and sequence diversity on a simple sequence repeat (SSR) locus of identical size, our study highlights that this molecular marker class can be a useful tool for population genetics and evolutionary studies for many plant species.
Characterization of microsatellite loci in Erysimum mediohispanicum (Brassicaceae) and cross‐amplification in related species
Authors: Muñoz‐Pajares A. Jesús , Herrador M. Belén , Abdelaziz Mohamed , Picó F. Xavier , Sharbel Timothy F. , Gómez José M. , Perfectti Francisco
Published: September 2011

• Premise of the study: We have developed and optimized microsatellite loci from a genomic library of Erysimum mediohispanicum. Microsatellites were also tested for cross‐amplification in 31 other Erysimum species.

• Methods and Results: A total of 10 microsatellite loci were successfully amplified. They were polymorphic for 81 E. mediohispanicum individuals from two locations in Sierra Nevada (southeastern Spain), which showed similar patterns of genetic diversity. On average, microsatellites had 8.6 alleles per locus and an expected heterozygosity of 0.69. Only one locus significantly departed from Hardy–Weinberg equilibrium in both locations. Most of the markers successfully amplified in other Erysimum species.

• Conclusions: The genetic attributes of microsatellite loci will allow their application to population genetic studies in Erysimum, such as genetic differentiation and structure, gene flow, pollinator‐mediated speciation, and hybridization studies.
«L'introuvable» césure public-privé en Algérie
Authors: Mebtoul Mohamed
Published: September 2011

Résumé Il s’agit ici de montrer la pertinence de construire des objets en santé en partant du fonctionnement du secteur privé, et notamment de celui des cliniques privées. La montée importante de la marchandisation du domaine des soins a conduit à une recomposition des rapports entre les pouvoirs publics, les spécialistes de l’hôpital et ceux du secteur privé. Recomposition qui se traduit notamment par l’émergence de nouveaux « entrepreneurs » dans le champ de la santé et par le déploiement de nouveaux rapports de travail entre le personnel de santé et les « patrons » de la clinique privée, qui contrastent avec ceux de l’hôpital. Celui-ci est pourtant au cœur du renforcement du secteur privé. Nous montrons les multiples imbrications entre les professionnels de la santé des deux secteurs, qui se font au profit du secteur privé. Celui-ci a en effet la possibilité de capter aisément le personnel de santé de l’hôpital, de s’approprier de façon dominante un nombre important de patients contraints d’assurer leurs examens « complémentaires » en son sein, parce qu’il est souvent le seul détenteur de certains moyens techniques, comme le scanner, par exemple. On insistera donc sur l’introuvable césure public / privé. Celui-ci se nourrit en réalité des dysfonctionnements des structures étatiques de soins et des logiques de fonctionnement des pouvoirs publics qui vont eux aussi contribuer, en légalisant l’activité complémentaire assurée par les spécialistes, à renforcer de façon détournée le secteur privé. Il a donc toute la latitude de mobiliser activement et dans une logique de réseaux, le personnel de santé de l’hôpital, tout en n’hésitant pas à intégrer les spécialistes des cabinets privés qui ont la possibilité d’investir la clinique pour opérer leurs malades. Cette alliance tacite entre les « patrons » des cliniques et les médecins privés, permet d’élargir les assises du secteur privé.
Des systèmes pathogènes à la santé publique : une nouvelle dimension pour la géographie de la santé tropicale
Authors: Handschumacher Pascal , Hervouët Jean-Pierre
Published: September 2011

Résumé La contribution des études géographiques à la connaissance des grandes endémies tropicales a été importante depuis la mise en place du programme de lutte contre l’onchocercose en 1975. Fortement articulées autour de collaborations avec biologistes et médecins, ces études ont permis de montrer l’importance de la gestion des espaces par les sociétés dans l’apparition, la diffusion et la propagation de ces grandes endémies. Par un jeu d’analyses à de multiples échelles tant spatiales que temporelles, cette approche a permis d’affiner un ensemble de concepts qui sont devenus autant d’outils indispensables à la compréhension du pouvoir épidémiogène des lieux. La multiplication des modèles dans des environnements différents a contribué à augmenter tant la connaissance des phénomènes que leur maîtrise théorique. Cependant, malgré ces progrès dans la connaissance bio-géographique des maladies et surtout ceux effectués dans le domaine de la thérapie et de la lutte, la situation sanitaire ne s’est guère améliorée pour de nombreuses pathologies que l’on pensait pouvoir éradiquer avant la fin du xx e siècle. Les nombreuses avancées obtenues dans la mise au point des outils cartographiques et statistiques ainsi que ce constat d’échec relatif d’un point de vue opérationnel nous obligent à resituer la priorité des enjeux sur les déterminants princeps des politiques de santé et sur l’adéquation entre connaissances sur la transmission et application en santé publique. La forte demande sociale contribue à donner une inflexion aux recherches géographiques, qui, en s’appuyant sur les nouveaux outils, s’inscrit délibérément dans une recherche appliquée à la santé publique.
L'illusion participative
Authors: Blanc-Pamard Chantal , Fauroux Emmanuel
Published: September 2011

Résumé Depuis une dizaine d’années, à Madagascar, les pratiques de gestion centralisées sont remplacées par des approches participatives qui reposent sur des principes simples directement inspirés du fonctionnement des démocraties occidentales : droit de tous à la parole, accès égal à l’information, décisions prises à la majorité des voix... Ces principes, malgré leur générosité, sont étrangers à l’idiosyncrasie des ruraux malgaches. La participation est pourtant recommandée de toutes parts et les bailleurs de fonds ne soutiennent plus un projet qui ne la considère pas comme une priorité. C’est encore, très probablement une illusion dans de nombreux cas, ce qui risque de conduire les projets et les opérations reposant sur l’approche participative à de nouveaux échecs, même s’ils s’avèrent sans doute moins cinglants que les échecs d’autrefois. On peut espérer que la participation devienne moins illusoire puisqu’elle s’inscrit dans un contexte de décentralisation qui instaure de nouveaux types de gouvernance et de gestion des ressources naturelles. La gestion partagée vise également à laisser aux communautés villageoises une réelle autonomie, notamment dans la protection de l’environnement. La situation actuelle marque une transition particulièrement délicate puisqu’on tente de mettre en place les conditions institutionnelles rendant possible ce partage de gestion. L’aspect apparemment novateur de la procédure est beaucoup plus grand qu’il n’y paraît à première vue dans un milieu où la démocratie participative est encore perçue comme une bizarrerie à laquelle les gens ne s’habituent pas vraiment.
Entre forêt et côte : l'inclusion négociée des Marrons ndjuka du Surinam
Authors: Parris Jean-Yves
Published: September 2011

Résumé Après avoir été considérés comme des survivances africaines dans le nouveau monde, les Noirs marrons du Surinam et, dans une certaine mesure, de la Guyane, sont aujourd’hui davantage envisagés comme des sociétés qui s’inscrivent dans le droit fil de l’esclavage et des formations sociales qui en émergèrent. À partir du cas des Marrons ndjuka, cet article explore la validité de cette proposition en examinant, tant sur le plan socio-historique que politique, les conditions de l’évolution de cette société à travers les rapports qu’elle a toujours entretenu avec l’univers colonial puis post-colonial.
Politique de stabilisation foncière et conservation de la biodiversité : le cas de la Réserve de Biosphère Maya, Petén (Guatemala)
Authors: Effantin Rachel , Hubert Bernard
Published: September 2011

Résumé Au Guatemala, une politique de conservation de la forêt tropicale du Petén succède à quatre décennies de colonisation agraire. Les préoccupations actuelles de stabilisation du front pionnier posent le problème du choix des instruments de régulation et des modalités de leur mise en œuvre. Les auteurs étudient l’incidence d’une intervention gouver-nementale sur la formalisation des normes d’appropriation et d’usage des ressources naturelles renouvelables. À cette fin, ils analysent la dynamique d’installation de nouvelles communautés dans la zone tampon de la Réserve de Biosphère Maya, où un programme de légalisation foncière et de conseil en agroforesterie est mis en œuvre. À partir de la chronologie des itinéraires fonciers et agraires de deux communautés, ils illustrent la diversité des traductions locales d’une intervention standardisée. Cette diversité a ensuite pu être associée au processus de différenciation sociale inhérent à la dynamique pionnière ainsi qu’à la variabilité des formes d’organisation collective. Si des changements dus à l’intervention ont effectivement lieu, ils ne transforment pas fondamentalement les projets de production des migrants, mais permettent d’améliorer les conditions de réalisation de certains de leurs projets.
La société ivoirienne au fil de ses réformes scolaires : une politique d'éducation « intermédiaire » est-elle possible ?
Authors: Lanoue Éric
Published: September 2011

Résumé Cet article examine deux aspects de la réforme éducative menée en Côte d’Ivoire entre 1993 et 1999 – la régulation des flux scolaires et la moralisation des pratiques de scolarisation – pour étudier les raisons de leur mise en échec. Cet échec tient à la force de configurations sociales et politiques, au principe d’un ensemble de pratiques illicites et d’un marché des biens scolaires (recrutement parallèle, achat de diplôme ou d’épreuve d’examen). Les configurations sociales et politiques esquissées illustrent un rapport symbolique à l’école secondaire, malgré les chances limitées d’accès au diplôme. Par-delà les normes économicistes des bailleurs de fonds, les politiques d’éducation pourraient intégrer ce rapport symbolique à l’institution scolaire et lui fournir un cadre d’interprétation ; faute de quoi les réformes éducatives risquent de continuer d’être perçues comme des formes de violence politiques exercées à l’encontre des populations.
CMRF-35–Like Molecule 3 Preferentially Promotes TLR9-Triggered Proinflammatory Cytokine Production in Macrophages by Enhancing TNF Receptor-Associated Factor 6 Ubiquitination
Authors: Wu Yanan , Zhu Xuhui , Li Nan , Chen Taoyong , Yang Mingjin , Yao Ming , Liu Xingguang , Jin Boquan , Wang Xiaobo , Cao Xuetao
Published: September 2011

TLRs are critical innate immune sensors in the induction of proinflammatory cytokines to eliminate invading pathogens. However, the mechanisms for the full activation of TLR-triggered innate immune response need to be fully understood. The murine CMRF-35–like molecule (CLM)-3 is a representative of CLM family belonging to the Ig superfamliy. Considering that CLM-3 is selectively expressed in macrophages and the roles of CLM members in innate immune response remain unclear, in this study we investigated the role of CLM-3 in the regulation of TLR-triggered innate response. We found that CLM-3 was an endosome/lysosome-localized molecule, and was downregulated in macrophages by stimulation with TLR9 ligand, but not TLR4 and TLR3 ligands. Interestingly, CLM-3 selectively promoted production of TNF-α and IL-6 in macrophages triggered by TLR9, but not TLR4 or TLR3. CLM-3 enhanced activation of MAPKs and NF-κB pathways in TLR9-triggered macrophages. Furthermore, CLM-3–transgenic mice were generated, and CLM-3 expression was confirmed by mAb against CLM-3 that we prepared. Accordingly, the macrophages derived from CLM-3–transgenic mice were more sensitive to TLR9 ligand stimulation, with more pronounced production of TNF-α, IL-6, and increased activation of MAPKs and NF-κB pathways. Moreover, ubiquitination of TNFR-associated factor 6, a crucial signaling transducer of TLR-triggered MAPKs and NF-κB activation, was found to be significantly promoted by CLM-3 in macrophages. Collectively, the endosome/lysosome-localized CLM-3 can promote full activation of TLR9-triggered innate responses by enhancing TNFR-associated factor 6 ubiquitination and subsequently activating MAPKs and NF-κB.
Pathogenic Autoreactive B Cells Are Not Negatively Selected toward Matrix Protein Collagen II
Authors: Cao Duojia , Khmaladze Ia , Jia Hongwei , Bajtner Estelle , Nandakumar Kutty S. , Blom Thomas , Mo John A. , Holmdahl Rikard
Published: September 2011

We have addressed the importance of B cell tolerance to collagen type II, a matrix protein, which is a target in rheumatoid arthritis (RA) and its mouse models. We generated a germline-encoded anti-collagen type II (CII) IgH replacement anti-C1 B cell mouse strain (ACB) to investigate how B cell tolerance to CII, a matrix protein, is subverted and to further understand pathogenesis of RA. Phenotypic analysis revealed that CII-specific B cells were surprisingly neither deleted nor anergized. Instead, they were readily detected in all lymphoid organs. Spontaneously produced autoantibodies could bind directly to cartilage surface without detectable pathology. However, exaggerated arthritis was seen after injection of anti-CII Abs specific for other epitopes. In addition, Abs from CII-specific hybridomas generated from ACB mice induced arthritis. Interestingly, IgH/L chain sequence data in B cell hybridomas revealed a lack of somatic mutations in autoreactive B cells. The ACB model provides the first possibility, to our knowledge, to study B cell tolerance to a matrix protein, and the observations made in the study could not be predicted from previous models. B cell-reactive epitopes on CII are largely shared between human RA and rodent CII-induced arthritis; this study, therefore, has important implications for further understanding of pathological processes in autoimmune diseases like RA.
Elevated Tumor-Associated Antigen Expression Suppresses Variant Peptide Vaccine Responses
Authors: Kemmler Charles B. , Clambey Eric T. , Kedl Ross M. , Slansky Jill E.
Published: September 2011

Variant peptide vaccines are used clinically to expand T cells that cross-react with tumor-associated Ags (TAA). To investigate the effects of elevated endogenous TAA expression on variant peptide-induced responses, we used the GP70 TAA model. Although young BALB/c mice display T cell tolerance to the TAA GP70423–431 (AH1), expression of GP70 and suppression of AH1-specific responses increases with age. We hypothesized that as TAA expression increases, the AH1 cross-reactivity of variant peptide-elicited T cell responses diminishes. Controlling for immunosenescence, we showed that elevated GP70 expression suppressed AH1 cross-reactive responses elicited by two AH1 peptide variants. A variant that elicited almost exclusively AH1 cross-reactive T cells in young mice elicited few or no T cells in aging mice with Ab-detectable GP70 expression. In contrast, a variant that elicited a less AH1 cross-reactive T cell response in young mice successfully expanded AH1 cross-reactive T cells in all aging mice tested. However, these T cells bound the AH1/MHC complex with a relatively short half-life and responded poorly to ex vivo stimulation with the AH1 peptide. Variant peptide vaccine responses were also suppressed when AH1 peptide is administered tolerogenically to young mice before vaccination. Analyses of variant-specific precursor T cells from naive mice with Ab-detectable GP70 expression determined that these T cells expressed PD-1 and had downregulated IL-7Rα expression, suggesting they were anergic or undergoing deletion. Although variant peptide vaccines were less effective as TAA expression increases, data presented in this article also suggest that complementary immunotherapies may induce the expansion of T cells with functional TAA recognition.
Spatial resolution of tropical terrestrial CO2 fluxes inferred using space-borne column CO2 sampled in different earth orbits: the role of spatial error correlations
Authors: Palmer P. I. , Feng L. , Bösch H.
Published: September 2011

Abstract. We use realistic numerical experiments to assess the sensitivity of 8-day CO2 flux estimates, inferred from space-borne short-wave infrared measurements of column-averaged CO2 dry air mixing ratio XCO2, to the choice of Earth observing orbit. We focus on three orbits: (1) a low-inclination circular orbit used by the NASA Tropical Rainfall Measuring Mission (TRMM); (2) a sun-synchronous orbit used by the Japanese Greenhouse Gases Observing SATellite (GOSAT) and proposed for the NASA Orbiting Carbon Observatory (OCO-2) instrument; and (3) a precessing orbit used by the International Space Station (ISS). For each orbit, we assume an instrument based on the specification of the OCO-2; for GOSAT we use the relevant instrument specification. Sun-synchronous orbits offer near global coverage within a few days but have implications for the density of clear-sky measurements. The TRMM and ISS orbits intensively sample tropical latitudes, with sun-lit clear-sky measurements evenly distributed between a.m./p.m. For a specified spatial resolution for inferred fluxes, we show there is a critical number of measurements beyond which there is a disproportionately small decrease in flux uncertainty. We also show that including spatial correlations for measurements and model errors (of length 300 km) reduces the effectiveness of high measurement density for flux estimation, as expected, and so should be considered when deciding sampling strategies. We show that cloud-free data from the TRMM orbit generally can improve the spatial resolution of CO2 fluxes achieved by OCO-2 over tropical South America, for example, from 950 km to 630 km, and that combining data from these low-inclination and sun-synchronous orbits have the potential to reduce this spatial length further. Decreasing the length of the error correlations to 50 km, reflecting anticipated future improvements to transport models, results in CO2 flux estimates on spatial scales that approach those observed by regional aircraft.
Nonstationarities in the occurrence rates of flood events in Portuguese watersheds
Authors: Silva A. T. , Portela M. M. , Naghettini M.
Published: September 2011

Abstract. An exploratory analysis on the variability of flood occurrence rates in Portuguese watersheds is made, to ascertain if that variability is concurrent with the principle of stationarity. A peaks-over-threshold (POT) sampling technique is applied to 10 long series of mean daily streamflows and to 4 long series of daily rainfall in order to sample the times of occurrence (POT time data) of the peak values of those series. The kernel occurrence rate estimator, coupled with a bootstrap approach, was applied to the POT time data to obtain the time dependent estimated occurrence rate curves, ˆλ(t), of floods and extreme rainfall events. The results of the analysis show that the occurrence of those events constitutes an inhomogeneous Poisson process, hence the occurrence rates are nonstationary. An attempt was made to assess whether the North Atlantic Oscillation (NAO) casted any influence on the occurrence rate of floods in the study area. Although further research is warranted, it was found that years with a less-than-average occurrence of floods tend to occur when the winter NAO is in the positive phase, and years with a higher occurrence of floods (more than twice the average) tend to occur when the winter NAO is in the negative phase. The authors conclude that the mathematical formulation of the flood frequency models relying on stationarity commonly employed in Portugal, should be revised in order to account for nonstationarities in the occurrence rates of such events.
Hypermotility of an iris-fixated anterior chamber phakic intraocular lens due to nontraumatic iris laxity
Authors: Taneri Suphi , Oehler Saskia , Koch Jörg M. , Heiligenhaus Arnd
Published: September 2011

Purpose

Permanent immovability of phakic intraocular lenses (pIOLs) for the correction of high myopia is crucial in avoiding injury to the corneal endothelium and maintaining visual acuity. Unstable position of iris-fixated pIOLs due to traumatic or nontraumatic disenclavation of the haptic has been described previously.

Methods and Results

We report a different mechanism of repeated excessive implant motility in both eyes of a young woman who developed late nontraumatic elongation of the iris fibers to which an iris-claw pIOL was fixated. This led to increased motility of the pIOLs with blinking causing mild iritis. Subsequent bilateral successful re-enclavation to other iris fibers ameliorated these symptoms. After 2.5 years, these iris fibers, too, were elongated, causing excessive movements of the pIOLs and consecutive endothelial cell loss necessitating removal of the pIOLs. The etiology of this iris fiber laxity remains unclear.

Conclusions

Surgeons should be aware of this rare potential complication.
The Differentiation of Humane Adult Mesenchimal Stem Cells of Bone Marrow (hMSC) into Urothelial Cells on Bio-Engineering Support (Scaffold): Preliminary Experience of Tissue Engineering
Authors: Falavolti Cristina , Rainer Alberto , Centola Matteo , Trombetta Marcella , Abbruzzese Franca , Gidaro Stefano , Sergi Federico , Buscarini Maurizio
Published: September 2011

Objectives

Tissue Engineering can develop scaffolds of Poly-L-Lactic Acid (PLLA) for tissue regeneration. The purpose of the present job is to test the possibility to seed human adult mesenchymal stem cells on a scaffold supplemented with specific grow factors to differentiate them into urothelium.

Methods

The Electrospinning technique was used to realize three scaffolds. The first one was seeded with urothelial cells, of a primary culture, and Keratinocyte serum free medium (KSFM); the second one was seeded with human mesenchymal stem cells (hMSC) and a minimum essential medium (αMEM); the third one was seeded with hMSC and conditioned medium.

Results

Electron microscopy showed scaffolds with cellular vitality (>90%) and their cellular proliferation. Moreover, the differentiation of hMSC, seeded in conditioned medium, into urothelial cells was demonstrated through immunofluorescence assays.

Conclusions

Tissue Engineering can develop PLLA scaffolds thanks to the Electrospinning technique. The scaffold is a perfect environment for cellular culture and proliferation; a protocol for the differentiation of hMSC into urothelial cells is now available. Immunofluorescence assays can demonstrate the hMSC differentiation into urothelial cells.
Lévy betas: Static hedging with index futures
Authors: Wong Hoi Ying , Hung Cheung Edwin Kwan , Wong Shiu Fung
Published: September 2011

This study considers calibration to forward‐looking betas by extracting information on equity and index options from prices using Lévy models. The resulting calibrated betas are called Lévy betas. The objective of the proposed approach is to capture market expectations for future betas through option prices, as betas estimated from historical data may fail to reflect structural change in the market. By assuming a continuous‐time capital asset pricing model (CAPM) with Lévy processes, we derive an analytical solution to index and stock options, thus permitting the betas to be implied from observed option prices. One application of Lévy betas is to construct a static hedging strategy using index futures. Employing Hong Kong equity and index option data from September 16, 2008 to October 15, 2009, we show empirically that the Lévy betas during the sub‐prime mortgage crisis period were much more volatile than those during the recovery period. We also find evidence to suggest that the Lévy betas improve static hedging performance relative to historical betas and the forward‐looking betas implied by a stochastic volatility model.
Arf6 promotes cell proliferation via the PLD‐mTORC1 and p38MAPK pathways
Authors: Knizhnik Anna V. , Kovaleva Olga V. , Komelkov Andrei V. , Trukhanova Luybov S. , Rybko Vera A. , Zborovskaya Irina B. , Tchevkina Elena M.
Published: September 2011

The small G‐protein ADP‐ribosylation factor 6 (Arf6) belongs to the Ras GTPases superfamily and is mostly known for its actin remodeling functions and involvement in the processes of plasma membrane reorganization and vesicular transport. The majority of data indicates that Arf6 contributes to cancer progression through activation of cell motility and invasion. Alternatively, we found that the expression of a wild‐type or a constitutively active Arf6 does not influence tumor cell motility and invasion but instead significantly stimulates cell proliferation and activates phospholipase D (PLD). Conversely the expression of a mutant Arf6 (Arf6N48I), that is, unable to interact with PLD has no effect on proliferation but promotes motility, invasion, and matrix degradation by uPA extracellular proteinase. Studying the mechanisms of Arf6‐dependent stimulation of cell proliferation, we found some signaling pathways contributing to Arf6 promitogenic activity. Namely, we showed that Arf6 in a PLD‐mTORC1‐dependent manner activates S6K1 kinase, a well‐known regulator of mitogen‐stimulated translation initiation. Furthermore, we demonstrated an Arf6‐dependent phosphorylation of mTORC1 downstream targets, 4E‐BP1 and ribosomal S6 protein, confirming an existence of Arf6‐PLD‐mTORC1‐S6K1/4E‐BP1 signaling pathway and also demonstrated its impact on proliferation stimulation. Next, we found that Arf6 activation potentiates Erk1/2 and p38MAP kinases phosphorylation. Surprisingly, p38 opposite to Erk1/2 significantly contributes to Arf6‐dependent proliferation increase promoting S6 ribosomal protein phosphorylation at Ser235/236 residues. Therefore, we demonstrated Arf6 proliferation stimulating activity and revealed PLD‐mTORC1 and p38MAP kinase as Arf6 partners mediating promitogenic activity. These results highlight a new aspect of Arf6 functioning in cancer cell biology. J. Cell. Biochem. 113: 360–371, 2012. © 2011 Wiley Periodicals, Inc.
Piwis and piwi‐interacting RNAs in the epigenetics of cancer
Authors: Siddiqi Sara , Matushansky Igor
Published: September 2011

An increasing body of evidence suggests that cancer cells acquire “stem‐like” epigenetic and signaling characteristics during the tumorigenic process, including global DNA hypo‐methylation, gene‐specific DNA hyper‐methylation, and small RNA deregulation. RNAs have been known to be epigenetic regulators, both in stem cells and in differentiated cells. A novel class of small RNAs, called piwi‐interacting RNAs (piRNAs), maintains genome integrity by epigenetically silencing transposons via DNA methylation, especially in germline stem cells. piRNAs interact exclusively with the Piwi family of proteins. The human Piwi ortholog, Hiwi, has been found to be aberrantly expressed in a variety of human cancers and in some, its expression correlates with poor clinical prognosis. However, there has been little investigation into the potential role that Piwi and piRNAs might play in contributing to the “stem‐like” epigenetic state of a cancer. This review will highlight the current evidence supporting the importance of Piwi and piRNAs in the epigenetics of cancer and provide a potential model for the role of Piwi and piRNAs in tumorigenesis. J. Cell. Biochem. 113: 373–380, 2012. © 2011 Wiley Periodicals, Inc.