Ablation of carbon-based materials : investigation of roughness set-up from heterogeneous reactions

International audienceAblation of carbon-based materials is a key issue in atmospheric reentry ; it displays a strong coupling between mass, momentum and heat transfers, the importance of which relies on the surface roughness. A new possible physical cause for roughness set-up is investigated, based on the coupling between diffusive transfer in the surrounding fluid on one hand, and heterogeneous reaction or sublimation on the other. Considering mass transfer in a 2D, isothermal, vertical-flux approximation, the surface is proved to be able to acquire, among others, a stable stationary morphology made of circle arcs connected by symmetrical singular points. Such a morphology has indeed been observed in the case of graphite ablation, and the computed roughness length scale, arising from the diffusion-to-reaction ratio, is compatible with observed data. A similar model based on the presence of a thermal gradient yields similar results, but with a larger length scale, also compatible with other observations

Characterization of a possible nosocomial aspergillosis outbreak

ObjectiveTo study the epidemiologic aspects of a suspected outbreak of nosocomial invasive aspergillosis.MethodsSixteen Aspergillus fumigatus strains were isolated from bronchoalveolar washings or sputa of 10 patients during a 9-month period. Furthermore, two environmental samples, isolated in a microbiological screening of the hospital, were also available for analysis. Random amplified polymorphic DNA analysis (RAPD) was carried out.ResultsThe analysis performed by RAPD clearly demonstrated substantial genetic variation among the isolates. Both of the two different primers selected for RAPD analysis (R-108 and AP12h) were able to demonstrate that the strains isolated from all patients infected with the same fungal species and the environmental samples were genotypically distinct. The results by RAPD typing demonstrated that this technique could detect variability among isolates of Aspergillus fumigatus from different patients and even from the same patient.ConclusionsRAPD genotyping proved that the outbreak of invasive aspergillosis consisted of a series of events, non-related, and probably not coming from the same source within the hospital. This type of analysis is an easy, quick and highly discriminatory technique that may help in planning epidemiologic studies of aspergillosis

Death or survival from invasive pneumococcal disease in Scotland: associations with serogroups and multilocus sequence types

We describe associations between death from invasive pneumococcal disease (IPD) and particular serogroups and sequence types (STs) determined by multilocus sequence typing (MLST) using data from Scotland. All IPD episodes where blood or cerebrospinal fluid (CSF) culture isolates were referred to the Scottish Haemophilus, Legionella, Meningococcal and Pneumococcal Reference Laboratory (SHLMPRL) from January 1992 to February 2007 were matched to death certification records by the General Register Office for Scotland. This represented 5959 patients. The median number of IPD cases in Scotland each year was 292. Deaths, from any cause, within 30 days of pneumococcal culture from blood or CSF were considered to have IPD as a contributing factor. Eight hundred and thirty-three patients died within 30 days of culture of Streptococcus pneumoniae from blood or CSF [13.95%; 95% confidence interval (13.10, 14.80)]. The highest death rates were in patients over the age of 75. Serotyping data exist for all years but MLST data were only available from 2001 onward. The risk ratio of dying from infection due to particular serogroups or STs compared to dying from IPD due to all other serogroups or STs was calculated. Fisher's exact test with Bonferroni adjustment for multiple testing was used. Age adjustment was accomplished using the Cochran-Mantel-Haenszel test and 95% confidence intervals were reported. Serogroups 3, 11 and 16 have increased probability of causing fatal IPD in Scotland while serogroup 1 IPD has a reduced probability of causing death. None of the 20 most common STs were significantly associated with death within 30 days of pneumococcal culture, after age adjustment. We conclude that there is a stronger association between a fatal outcome and pneumococcal capsular serogroup than there is between a fatal outcome and ST

Conceptualisations of children’s wellbeing at school: the contribution of recognition theory

A large study in Australian schools aimed to elucidate understandings of ‘wellbeing’ and of factors in school life that contribute to it. Students and teachers understood wellbeing primarily, and holistically, in terms of interpersonal relationships, in contrast to policy documents which mainly focused on ‘problem areas’ such as mental health. The study also drew on recognition theory as developed by the social philosopher Axel Honneth. Results indicate that recognition theory may be useful in understanding wellbeing in schools, and that empirical research in schools may give rise to further questions regarding theory

Effect of transport length on in vivo oxidative status and breast meat characteristics in outdoor-reared chicken genotypes

The aim of the study was to evaluate the effect of transport length on in vivo oxidative status and breast meat characteristics in two chicken genotypes reared under free range conditions. A total of 200 male chicks, 100 from fast-growing (Ross 308) and 100 from medium-growing (Naked Neck) strain were used. Fifty-six of these, 28 for genotype, before slaughtering, were randomly allocated to 2 pre-slaughter conditions: absence (0 h) or 4 h of transport. The transport length significantly affected the in vivo oxidative status of broiler greatly reducing the α and δ-tocopherol, retinol and lutein + zeaxanthin content of plasma, and increased the oxidative stress (thiobarbituric acid reactive substances, TBARS) in both strains. Concerning meat quality, the pH (0, 2 and 24 h post-mortem) of breast muscles of chickens transported for 4 h, showed higher values, and respect to strains, Naked Neck had lower values. The pH values were negatively correlated with the lightness (2–24 h) and the shear force of meat. The transport length significantly affected the fatty acid profile of breast muscle, with a decrease in polyunsaturated fatty acids and an increase in TBARS value. Even the antioxidants content of breast was reduced by chicken transport (α-tocotrienol, α-, δ-tocopherol and lutein + zeaxanthin), especially in Naked Neck birds. In conclusion, the results indicate that transport for 4 h prior to slaughter, negatively affect the meat quality of poultry. Slow-growing chickens seem more sensible to stress transport due to the higher kinetic behaviour of these strains

Espècie aviària: manual lesional de suport per al dictamen de carns fresques

Escorxador; Aviram; Pollastres; Carn: Control oficialMatadero; Aves de corral; Pollos; Carne: Control oficialSlaughterhouse; Poultry; Chickens; Meat: Official controlLa inspecció post mortem de les carns d’aviram que efectua el col·lectiu de veterinaris oficials d’escorxador és una part important dels controls oficials relatius a la carn fresca i, com a tal, és un dels elements que condiciona que es dictamini com a apta o no per al consum humà i que s’hagin de notificar les malalties de declaració obligatòria. Els escorxadors són entorns òptims per observar i registrar les particularitats de la variada patologia animal que s’hi presenta. Aquesta informació, si és compartida, pot esdevenir una eina molt útil i interessant per al col·lectiu de professionals. En conseqüència la comunitat de pràctica (CoP) ha realitzat aquest manual l’autoria del qual és de veterinaris oficials d’escorxador de la Generalitat de Catalunya. El contingut s’ha volgut transmetre per mitjà de fitxes que contenen informació científica, tècnica i legal per a cada una de les malalties i lesions que s’hi descriuen. Alhora, les fitxes s’il·lustren amb imatges obtingudes a diferents escorxadors d’aviram de Catalunya. El propòsit és que les fitxes puguin ser un suport pràctic per a la inspecció post mortem i una ajuda per al dictamen. Per això, s’ha procurat establir un posicionament vers el dictamen de les carns amb els motius desenvolupats de la manera més concreta possible. Cal dir que en alguns casos no ha estat possible obtenir imatges que il·lustrin algunes de les lesions o malalties que s’hi defineixen.La inspección post mortem de las carnes de aves de corral que efectúa el colectivo de veterinarios oficiales de matadero es una parte importante de los controles oficiales relativos a la carne fresca y, como tal, es uno de los elementos que condiciona que se dictamine como a apta o no para el consumo humano y que deban notificarse las enfermedades de declaración obligatoria. Los mataderos son entornos óptimos para observar y registrar las particularidades de la variada patología animal que se presenta. Esta información, si es compartida, puede convertirse en una herramienta muy útil e interesante para el colectivo de profesionales. En consecuencia, la comunidad de práctica (CoP) ha realizado este manual cuya autoría es de veterinarios oficiales de matadero de la Generalitat de Catalunya. El contenido se ha querido transmitir por medio de fichas que contienen información científica, técnica y legal para cada una de las enfermedades y lesiones que se describen. Asimismo, las fichas se ilustran con imágenes obtenidas en diferentes mataderos de aves de corral de Cataluña. El propósito es que las fichas puedan ser un soporte práctico para la inspección post mortem y una ayuda para el dictamen. Por eso, se ha procurado establecer un posicionamiento hacia el dictamen de las carnes con los motivos desarrollados de la forma más concreta posible. Hay que decir que en algunos casos no ha sido posible obtener imágenes que ilustren algunas de las lesiones o enfermedades que se definen.The post mortem inspection of poultry meat carried out by the group of official slaughterhouse veterinarians is an important part of the official controls related to fresh meat and, as such, is one of the elements that determines whether it is ruled as a suitable or not for human consumption and that notifiable diseases must be notified. Slaughterhouses are optimal environments to observe and record the particularities of the varied animal pathology that occurs. This information, if shared, can become a very useful and interesting tool for the group of professionals. Consequently, the community of practice (CoP) has produced this manual authored by official slaughterhouse veterinarians of the Generalitat de Catalunya. The content has been conveyed through sheets containing scientific, technical and legal information for each of the diseases and injuries described. Likewise, the sheets are illustrated with images obtained in different poultry slaughterhouses in Catalonia. The purpose is that the cards can be a practical support for the post mortem inspection and an aid for the opinion. For this reason, an attempt has been made to establish a position towards the opinion of meats with the reasons developed in the most concrete way possible. It must be said that in some cases it has not been possible to obtain images that illustrate some of the injuries or diseases that are defined

Influence of genetic variability at the surfactant proteins A and D in community-acquired pneumonia : a prospective, observational, genetic study

Introduction: Genetic variability of the pulmonary surfactant proteins A and D may affect clearance of microorganisms and the extent of the inflammatory response. The genes of these collectins (SFTPA1, SFTPA2 and SFTPD) are located in a cluster at 10q21-24. The objective of this study was to evaluate the existence of linkage disequilibrium (LD) among these genes, and the association of variability at these genes with susceptibility and outcome of community-acquired pneumonia (CAP). We also studied the effect of genetic variability on SP-D serum levels. Methods: Seven non-synonymous polymorphisms of SFTPA1, SFTPA2 and SFTPD were analyzed. For susceptibility, 682 CAP patients and 769 controls were studied in a case-control study. Severity and outcome were evaluated in a prospective study. Haplotypes were inferred and LD was characterized. SP-D serum levels were measured in healthy controls. Results: The SFTPD aa11-C allele was significantly associated with lower SP-D serum levels, in a dose-dependent manner. We observed the existence of LD among the studied genes. Haplotypes SFTPA1 6A2 (P = 0.0009, odds ration (OR) = 0.78), SFTPA2 1A0 (P = 0.002, OR = 0.79), SFTPA1-SFTPA2 6A2-1A0 (P = 0.0005, OR = 0.77), and SFTPD-SFTPA1-SFTPA2 C-6A2-1A0 (P = 0.00001, OR = 0.62) were underrepresented in patients, whereas haplotypes SFTPA2 1A10 (P = 0.00007, OR = 6.58) and SFTPA1-SFTPA2 6A3-1A (P = 0.0007, OR = 3.92) were overrepresented. Similar results were observed in CAP due to pneumococcus, though no significant differences were now observed after Bonferroni corrections. 1A10 and 6A-1A were associated with higher 28-day and 90-day mortality, and with multi-organ dysfunction syndrome (MODS) and acute respiratory distress syndrome (ARDS) respectively. SFTPD aa11-C allele was associated with development of MODS and ARDS. Conclusions: Our study indicates that missense single nucleotide polymorphisms and haplotypes of SFTPA1, SFTPA2 and SFTPD are associated with susceptibility to CAP, and that several haplotypes also influence severity and outcome of CAP

Rethinking place-making: aligning placeness factors with perceived urban design qualities (PUDQs) to improve the built environment in historical district

Understanding the concept of place is critically important for urban design and place-making practice, and this research attempted to investigate the pathways by which perceived urban design qualities (PUDQs) influence placeness factors in the Chinese context. Twelve hypotheses were developed and combined in a structural equation model for validation. The Tanhualin historical district in Wuhan, China was selected for the analysis. As a result, place attachment was verified as a critical bridge factor that mediated the influence of PUDQs on place satisfaction. Among the five selected PUDQs, walkability and space quality were revealed as the most influential factors associated with place attachment and place satisfaction. Accessibility was actually indirectly beneficial to place-making via the mediation of walkability. Corresponding implications and strategies were discussed to maintain the sense of place for historic districts