Giant proximity effect in a phase-fluctuating superconductor

When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this novel proximity effect by a general argument as well as a numerical simulation and argue that it may underlie recent experimental observations of the giant proximity effect between two cuprate superconductors separated by a barrier made of the same material rendered normal by severe underdoping.Comment: 4 pages, 3 figures; version to appear in PRL (results of simulations in 3d added). For related work and info visit http://www.physics.ubc.ca/~fran

Asklerogene pneumokonioze

Nous avons essayé dans le vaste tableau des pneumoconioses non. sclérogènes de mettre un peu d\u27ordre. Tout d\u27abord il y a lieu de faire rentrer dans le cadre de la silicose les diverses pneumoconioses où l\u27action de la silice est prédominante. Il s\u27agit de silicoses à poussières mixtes. Ensuite on peut ranger les pneumoconioses qui ne sont pas caractérisées par une fibrose diffuse progressive et qui n\u27entrainent des symptômes morbides que par leur accumulation dans le champ pulmonaire. Les rnétalloconioses donnent des images radiographiques particulières dues a la radioopacité des poussières inhalées. Elles n\u27entraient pas de sclérose sauf dans les cas de mélange avec la silice et elles entrent alors dans le cas des silicoses à poussières mixtes, sidère-silicose par exemple. Certaines poussières métalliques donnent lieu à. des accès hyperthermiques passagers, d\u27autres engendrent des pneumopathies aigües, d\u27 autres entrainent des formations granulomateuses, beaucoup laissent simplement une marque radio opaque. Les mycoconioses ou pneumomycoses sont plutôt des pneumopathies que des pneumoconioses. Elle3 sont à rechercher dans les professions où les sujets sont en contact avec les animaux ou les végétaux. Sous le nom d\u27allergoconioses nous rangeons les manifestations allergiques consécutives à l\u27inhalation de poussières végétales, en indiquant qu\u27elles peuvent elles aussi être associées à une pneumoconiose ou à une silicose. Notre classification est sujette à critiques, elle n\u27est que temporaire en attendant une meilleure mise en ordre.Autor predlaže novu klasifikaciju asklerogenih pneumokonioza. Po toj klasifikaciji treba među silikoze svrstati pneumokonioze uzrokovane miješanom prašinom, u kojoj je kvarc glavni sastavni dio. Prašine, koje izazivaju sliku bolesti samo zbog nakupljanja u plućima, uzrok su pneumokoniozama. Za metalokonioze je karakteristična rentgenska slika, koja nastaje zbog nepropusnosti prašine za rentgenske zrake. Te prašine, ukoliko nisu miješane s kvarcom, ne izazivaju silikozu nego druge simptome kao prolaznu hipertermiju, akutne pneumonije, granulomatozne formacije ili samo plućna zasjenjenja, već prema metalu, koji ih izaziva. Mikokonioze ili pneumomikoze su pneumopatije ljudi, koji su u kontaktu s biljem i životinjama. Medu alergokonioze pripadaju alergične manifestacije nakon udisanja biljne prašine, koje katkada dolaze u kombinaciji s pneumokoniozama i silikozom. Plućne promjene ne zavise samo od vrste prašine, nego i od broja i dimenzije čestica, trajanja ekspozicije i individualne osjetljivosti. Sve prašine zapravo oštećuju plućni epitel, a svaki je pojedinac manje ili više osjetljiv za bar jednu od navedenih vrsta prašine. Prema tome neškodljivih prašina nema, i zato se treba ozbiljno boriti za prevenciju svih vrsta pneumokonioza

L'adaptation des superviseurs à la gestion participative de la prévention des accidents

Cet article porte sur les approches utilisées dans les organisations pour amener les superviseurs à adopter un mode de gestion plus participatif de la sécurité au travail avec leurs employés. Les données présentées sont basées sur cinq études de cas réalisées selon un devis commun et analysées de façon comparative. Utilisant l'approche systémique du changement organisationnel, les auteurs développent le concept de stratégie de changement pour analyser les approches organisationnelles observées, en faisant l'hypothèse que ce sont les stratégies plus systématiques qui auront comme effets d'accroître l'utilisation de la gestion participative de la prévention par les superviseurs, et de réduire le taux de fréquence des accidents. Les résultats confirment largement les hypothèses, mais l'analyse montre aussi que les stratégies non efficaces, au plan des effets escomptés, ont néanmoins une fonction d'utilité qui est discutée.Over the last few decades, various countries have adopted laws and regulations fostering joint regulation and labour participation approaches in occupational heath and safety through joint health and safety committees, safety representatives, and workers' rights to be informed about work hazards and to refuse dangerous work. In order to succeed, these mechanisms should not remain isolated, but should be accompanied by larger organizational changes in labour relations, union and management practices. This article is about one of these organizational changes, namely, the transformation of supervisory management practices in occupational safety towards a more participative approach.Concepts and HypothesesGetting supervisors to adopt a participative management approach in occupational safety means changing their tasks and their way of doing them. From the perspective of a Systems theory of organizational change, it can be hypothesized that such a change will succeed only if consistent changes are brought about in other major components of the organizational System, namely : the individuals and groups involved; the formal organizational structures supporting and controlling individuals in their tasks; and the informal political and cultural dynamics of the organization. Each of these other components may present problems during the change process: resistance to change from individuals and groups; loss of control from formal structures; or loss of support from power groups and fallure of adjustment of cultural corporate values. The concept of organizational change strategy is used to designate all actions taken in the organization to address the aforementioned problems. Consequently, change strategies, which are the independent variable in this study, may be more or less developed and systematic. It is hypothesized that when the change strategy is more developed and systematic, (1) supervisors will use a more participative approach in managing prevention activities (inspection, task analysis, safety meetings, design of corrective measures, etc.) that is, getting their employees to participate in these activities, and (2) the lost-time accident frequency rate will be reduced. Variations in participative supervisory management of occupational safety and lost-time accident frequency rate are, therefore, the dependent variables in the study. A third hypothesis is that a greater use of safety participative management by supervisors should be related to a lower accident frequency rate. Figure 1 in the article illustrates this conceptual model and the hypotheses.MethodsThe study was conducted in five industrial firms located in the province of Quebec, Canada. These firms were selected from a larger sample, using a quota method, in order to include (1) different industrial sectors, (2) different firm sizes, (3) unionized and non-unionized firms, and (4)various geographical locations. In each firm, data were collected through (l)semi-structured interviews (n = 55) with supervisors, workers' representatives, top and middle managers, safety managers and members of the health and safety committee, and (2) questionnaires filled out by all supervisors (n = 63) and various other managers (n = 29).The development level of each change strategy (the independent variable) was measured using a scale (1-10) theoretically constructed by defining a total of ten dimensions referring to the three major change problems (resistance, control, and power and culture) that should be addressed and can be solved by consistent action steps during the change process. Data on actions taken, means and measures used by firms between 1988 and 1992 to encourage supervisors to use safety participative management, were collected and analyzed according to these ten dimensions.Variations in the use of participative safety management by supervisors (the dependent variable) were estimated (+/-) using data collected from various sources, including supervisors, about the evolution of the latter's management practices between 1988 and 1992. The last dependent variable, variation in the lost-time accident frequency rate, was measured by comparing the rates between the first and last year of a given strategy during the period under study. ResultsTable 2 presents the main results of the study. On the left side of the table, each of the ten strategies observed is identified, its level of development is indicated, and the number of dimensions for which action steps were taken is mentioned for each of the three major problems of the change process. On the right side, data is provided about dependent variables. Generally speaking, results largely support the hypotheses. More developed and systematic strategies (A-2, D-2, D-4, E, B, C-2) are all followed by an increase in the supervisors' use of participative safety management and a decrease in the accident frequency rate, while three out of the four less developed and systematic strategies (A-l, C-l, D-3) have inverse results.Discussion and ConclusionAlthough the results provide strong support for the hypotheses and confirm the results of previous studies about the positive impact of participative supervisory management on accident rates, the case studies also shows that non-effective strategies have had an important function in the social construction of effective strategies of organizational change. In brief, all non-effective strategies are characterized by an important unsolved problem of supervisors' and workers' resistance to the change in the safety practices expected by the organization. It appeared that this resistance is not only psychosocial, as generally conceptualized in the Systems theory of organizational change, but is also sociological in terms of a strategy used by supervisors and work teams to negotiate their place in the new "organizational order" which is constructed in the change process. Actually, this social process of "implicit bargaining" appears to be the main mechanism for the social construction of more effective strategies, that is, strategies addressing the resistance problem by developing change ownership by supervisors and workers, the power and culture problem by raising the top management commitment in the change process, and the structural support problem by adapting formal Systems of management in a manner consistent with the desired change

Conversion in Turkish : an overview

This paper presents an overview of possible cases of conversion in Turkish. I argue that apparent cases of conversion between nouns and adjectives are cases of syntactic transposition, and apparent cases of conversion between nouns/adjectives and verbs are end products of phonological changes in the history of the language, which resulted in pairs of lexemes that are formally identical synchronically, but not historically. This does not mean that no cases of morphological conversion can be traced in the language. I will present two cases of secondary word-class conversion from derived, inflected and uninflected words to toponyms which might be taken as instances of morphological conversion or derivation by zero-affixation

Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions

Significant reductions in stratospheric ozone occur inside the polar vortices each spring when chlorine radicals produced by heterogeneous reactions on cold particle surfaces in winter destroy ozone mainly in two catalytic cycles, the ClO dimer cycle and the ClO/BrO cycle. Chlorofluorocarbons (CFCs), which are responsible for most of the chlorine currently present in the stratosphere, have been banned by the Montreal Protocol and its amendments, and the ozone layer is predicted to recover to 1980 levels within the next few decades. During the same period, however, climate change is expected to alter the temperature, circulation patterns and chemical composition in the stratosphere, and possible geo-engineering ventures to mitigate climate change may lead to additional changes. To realistically predict the response of the ozone layer to such influences requires the correct representation of all relevant processes. The European project RECONCILE has comprehensively addressed remaining questions in the context of polar ozone depletion, with the objective to quantify the rates of some of the most relevant, yet still uncertain physical and chemical processes. To this end RECONCILE used a broad approach of laboratory experiments, two field missions in the Arctic winter 2009/10 employing the high altitude research aircraft M55-Geophysica and an extensive match ozone sonde campaign, as well as microphysical and chemical transport modelling and data assimilation. Some of the main outcomes of RECONCILE are as follows: (1) vortex meteorology: the 2009/10 Arctic winter was unusually cold at stratospheric levels during the six-week period from mid-December 2009 until the end of January 2010, with reduced transport and mixing across the polar vortex edge; polar vortex stability and how it is influenced by dynamic processes in the troposphere has led to unprecedented, synoptic-scale stratospheric regions with temperatures below the frost point; in these regions stratospheric ice clouds have been observed, extending over >106km2 during more than 3 weeks. (2) Particle microphysics: heterogeneous nucleation of nitric acid trihydrate (NAT) particles in the absence of ice has been unambiguously demonstrated; conversely, the synoptic scale ice clouds also appear to nucleate heterogeneously; a variety of possible heterogeneous nuclei has been characterised by chemical analysis of the non-volatile fraction of the background aerosol; substantial formation of solid particles and denitrification via their sedimentation has been observed and model parameterizations have been improved. (3) Chemistry: strong evidence has been found for significant chlorine activation not only on polar stratospheric clouds (PSCs) but also on cold binary aerosol; laboratory experiments and field data on the ClOOCl photolysis rate and other kinetic parameters have been shown to be consistent with an adequate degree of certainty; no evidence has been found that would support the existence of yet unknown chemical mechanisms making a significant contribution to polar ozone loss. (4) Global modelling: results from process studies have been implemented in a prognostic chemistry climate model (CCM); simulations with improved parameterisations of processes relevant for polar ozone depletion are evaluated against satellite data and other long term records using data assimilation and detrended fluctuation analysis. Finally, measurements and process studies within RECONCILE were also applied to the winter 2010/11, when special meteorological conditions led to the highest chemical ozone loss ever observed in the Arctic. In addition to quantifying the 2010/11 ozone loss and to understand its causes including possible connections to climate change, its impacts were addressed, such as changes in surface ultraviolet (UV) radiation in the densely populated northern mid-latitudes

Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions : (RECONCILE) ; activities and results

The international research project RECONCILE has addressed central questions regarding polar ozone depletion, with the objective to quantify some of the most relevant yet still uncertain physical and chemical processes and thereby improve prognostic modelling capabilities to realistically predict the response of the ozone layer to climate change. This overview paper outlines the scope and the general approach of RECONCILE, and it provides a summary of observations and modelling in 2010 and 2011 that have generated an in many respects unprecedented dataset to study processes in the Arctic winter stratosphere. Principally, it summarises important outcomes of RECONCILE including (i) better constraints and enhanced consistency on the set of parameters governing catalytic ozone destruction cycles, (ii) a better understanding of the role of cold binary aerosols in heterogeneous chlorine activation, (iii) an improved scheme of polar stratospheric cloud (PSC) processes that includes heterogeneous nucleation of nitric acid trihydrate (NAT) and ice on non-volatile background aerosol leading to better model parameterisations with respect to denitrification, and (iv) long transient simulations with a chemistry-climate model (CCM) updated based on the results of RECONCILE that better reproduce past ozone trends in Antarctica and are deemed to produce more reliable predictions of future ozone trends. The process studies and the global simulations conducted in RECONCILE show that in the Arctic, ozone depletion uncertainties in the chemical and microphysical processes are now clearly smaller than the sensitivity to dynamic variability

Ribosomal RNA 2′O-methylation as a novel layer of inter-tumour heterogeneity in breast cancer

International audienceRecent epitranscriptomics studies unravelled that ribosomal RNA (rRNA) 2′O-methylation is an additional layer of gene expression regulation highlighting the ribosome as a novel actor of translation control. However, this major finding lies on evidences coming mainly, if not exclusively, from cellular models. Using the innovative next-generation RiboMeth-seq technology, we established the first rRNA 2′O-methylation landscape in 195 primary human breast tumours. We uncovered the existence of compulsory/stable sites, which show limited inter-patient variability in their 2′O-methylation level, which map on functionally important sites of the human ribosome structure and which are surrounded by variable sites found from the second nucleotide layers. Our data demonstrate that some positions within the rRNA molecules can tolerate absence of 2′O-methylation in tumoral and healthy tissues. We also reveal that rRNA 2′O-methylation exhibits intra- and inter-patient variability in breast tumours. Its level is indeed differentially associated with breast cancer subtype and tumour grade. Altogether, our rRNA 2′O-methylation profiling of a large-scale human sample collection provides the first compelling evidence that ribosome variability occurs in humans and suggests that rRNA 2′O-methylation might represent a relevant element of tumour biology useful in clinic. This novel variability at molecular level offers an additional layer to capture the cancer heterogeneity and associates with specific features of tumour biology thus offering a novel targetable molecular signature in cancer

Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

BACKGROUND: Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. METHODS: Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. RESULTS: Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. CONCLUSION: The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers

Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits

Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.Peer reviewe

Particulate matter exposure during pregnancy is associated with birth weight, but not gestational age, 1962-1992: a cohort study

<p>Abstract</p> <p>Background</p> <p>Exposure to air pollutants is suggested to adversely affect fetal growth, but the evidence remains inconsistent in relation to specific outcomes and exposure windows.</p> <p>Methods</p> <p>Using birth records from the two major maternity hospitals in Newcastle upon Tyne in northern England between 1961 and 1992, we constructed a database of all births to mothers resident within the city. Weekly black smoke exposure levels from routine data recorded at 20 air pollution monitoring stations were obtained and individual exposures were estimated via a two-stage modeling strategy, incorporating temporally and spatially varying covariates. Regression analyses, including 88,679 births, assessed potential associations between exposure to black smoke and birth weight, gestational age and birth weight standardized for gestational age and sex.</p> <p>Results</p> <p>Significant associations were seen between black smoke and both standardized and unstandardized birth weight, but not for gestational age when adjusted for potential confounders. Not all associations were linear. For an increase in whole pregnancy black smoke exposure, from the 1^st(7.4 μg/m³) to the 25^th(17.2 μg/m³), 50^th(33.8 μg/m³), 75^th(108.3 μg/m³), and 90^th(180.8 μg/m³) percentiles, the adjusted estimated decreases in birth weight were 33 g (SE 1.05), 62 g (1.63), 98 g (2.26) and 109 g (2.44) respectively. A significant interaction was observed between socio-economic deprivation and black smoke on both standardized and unstandardized birth weight with increasing effects of black smoke in reducing birth weight seen with increasing socio-economic disadvantage.</p> <p>Conclusions</p> <p>The findings of this study progress the hypothesis that the association between black smoke and birth weight may be mediated through intrauterine growth restriction. The associations between black smoke and birth weight were of the same order of magnitude as those reported for passive smoking. These findings add to the growing evidence of the harmful effects of air pollution on birth outcomes.</p