Aerodynamic characteristics and genesis of aggregates at Sakurajima Volcano, Japan.

Aggregation of volcanic ash is known to significantly impact sedimentation from volcanic plumes. The study of particle aggregates during tephra fallout is crucial to increase our understanding of both ash aggregation and sedimentation. In this work, we describe key features of ash aggregates and ash sedimentation associated with eleven Vulcanian explosions at Sakurajima Volcano (Japan) based on state-of-the-art sampling techniques. We identified five types of aggregates of both Particle Cluster (PC) and Accretionary Pellet (AP) categories. In particular, we found that PCs and the first and third type of APs can coexist within the same eruption in rainy conditions. We also found that the aerodynamic properties of aggregates (e.g., terminal velocity and density) depend on their type. In addition, grainsize analysis revealed that characteristics of the grainsize distributions (GSDs) of tephra samples correlate with the typology of the aggregates identified. In fact, bimodal GSDs correlate with the presence of cored clusters (PC3) and liquid pellets (AP3), while unimodal GSDs correlate either with the occurrence of ash clusters (PC1) or with the large particles (coarse ash) coated by fine ash (PC2).

Intercellular bridges coordinate the transition from pluripotency to meiosis in mouse fetal oocytes.

Meiosis is critical to generating oocytes and ensuring female fertility; however, the mechanisms regulating the switch from mitotic primordial germ cells to meiotic germ cells are poorly understood. Here, we implicate intercellular bridges (ICBs) in this state transition. We used three-dimensional in toto imaging to map meiotic initiation in the mouse fetal ovary and revealed a radial geometry of this transition that precedes the established anterior-posterior wave. Our studies reveal that appropriate timing of meiotic entry across the ovary and coordination of mitotic-meiotic transition within a cyst depend on the ICB component Tex14, which we show is required for functional cytoplasmic sharing. We find that Tex14 mutants more rapidly attenuate the pluripotency transcript Dppa3 upon meiotic initiation, and Dppa3 mutants undergo premature meiosis similar to Tex14 Together, these results lead to a model that ICBs coordinate and buffer the transition from pluripotency to meiosis through dilution of regulatory factors.

Origin of a cryptic lineage in a threatened reptile through isolation and historical hybridization.

Identifying phylogenetically distinct lineages and understanding the evolutionary processes by which they have arisen are important goals of phylogeography. This information can also help define conservation units in endangered species. Such analyses are being transformed by the availability of genomic-scale data sets and novel analytical approaches for statistically comparing different historical scenarios as causes of phylogeographic patterns. Here, we use genomic-scale restriction-site-associated DNA sequencing (RADseq) data to test for distinct lineages in the endangered Eastern Massasauga Rattlesnake (Sistrurus catenatus). We then use coalescent-based modeling techniques to identify the evolutionary mechanisms responsible for the origin of the lineages in this species. We find equivocal evidence for distinct phylogenetic lineages within S. catenatus east of the Mississippi River, but strong support for a previously unrecognized lineage on the western edge of the range of this snake, represented by populations from Iowa, USA. Snakes from these populations show patterns of genetic admixture with a nearby non-threatened sister species (Sistrurus tergeminus). Tests of historical demographic models support the hypothesis that the genetic distinctiveness of Iowa snakes is due to a combination of isolation and historical introgression between S. catenatus and S. tergeminus. Our work provides an example of how model-based analysis of genomic-scale data can help identify conservation units in rare species.

Simultaneous estimation of multiple quantitative trait loci and growth curve parameters through hierarchical Bayesian modeling.

A novel hierarchical quantitative trait locus (QTL) mapping method using a polynomial growth function and a multiple-QTL model (with no dependence in time) in a multitrait framework is presented. The method considers a population-based sample where individuals have been phenotyped (over time) with respect to some dynamic trait and genotyped at a given set of loci. A specific feature of the proposed approach is that, instead of an average functional curve, each individual has its own functional curve. Moreover, each QTL can modify the dynamic characteristics of the trait value of an individual through its influence on one or more growth curve parameters. Apparent advantages of the approach include: (1) assumption of time-independent QTL and environmental effects, (2) alleviating the necessity for an autoregressive covariance structure for residuals and (3) the flexibility to use variable selection methods. As a by-product of the method, heritabilities and genetic correlations can also be estimated for individual growth curve parameters, which are considered as latent traits. For selecting trait-associated loci in the model, we use a modified version of the well-known Bayesian adaptive shrinkage technique. We illustrate our approach by analysing a sub sample of 500 individuals from the simulated QTLMAS 2009 data set, as well as simulation replicates and a real Scots pine (Pinus sylvestris) data set, using temporal measurements of height as dynamic trait of interest.

Polymorphism at the avpr1a locus in male prairie voles correlated with genetic but not social monogamy in field populations.

Integrative studies of genetics, neurobiology and behaviour indicate that polymorphism in specific genes contributes to variation observed in some complex social behaviours. The neuropeptide arginine vasopressin plays an important role in the regulation of a variety of social behaviours, including social attachment of males to females, through its action on the vasopressin 1a receptor (V1aR). In socially monogamous prairie voles (Microtus ochrogaster), polymorphism in the length of microsatellite DNA within the regulatory region of the gene (avpr1a) encoding the V1aR predicts differences among males in neural expression of V1aRs and partner preference under laboratory conditions. However, understanding the extent to which V1aR mediates variation in prairie vole social and reproductive behaviour observed in nature requires investigating the consequences of avpr1a polymorphism and environmental influences under ecologically relevant conditions. We examined the relationship between avpr1a length polymorphism and monogamy among male prairie voles living in 0.1 ha enclosures during a time similar to their natural lifespan. We found no evidence that avpr1a genotype of males predicts variation in social monogamy measured in the field but some indices of social monogamy were affected by population density. Parentage data indicated that a male's avpr1a genotype significantly influenced the number of females with which he sired offspring and the total number of offspring sired. Total brain concentrations of V1aR mRNA were not associated with either male behaviour or avpr1a genotype. These data show that melding ecological field studies with neurogenetics can substantially augment our understanding of the effects of genes and environment on social behaviours.

"Hitting the nail on the head".

Subungual malignant melanoma is a rare form of malignancy that can present at an advanced stage. We describe a case that was diagnosed after a presentation to the emergency department for a traumatic injury of the affected area. Initial presentations of malignant disease and its complications form a relatively low proportion of the caseload of emergency doctors. In this case, a patient presented after a minor injury that had failed to recover; subsequent investigation of this injury led to the diagnosis of subungual malignant melanoma in an otherwise asymptomatic patient. This is a rare case which presented in an atypical fashion, with a confounding history of minor trauma. It is presented to highlight the differential diagnosis of destructive bone lesions.

A comparison between the short term and long term benefits of screening for abdominal aortic aneurysms from the Huntingdon Aneurysm screening programme.

BACKGROUND: The UK Multicentre Aneurysm Screening Study (MASS) showed a 44% reduction in AAA-related mortality after 4 years and predicted an increased number of deaths prevented in the longer term. We aim to compare the 5 and 13 years benefit from aneurysm screening in the Huntingdon Aneurysm screening programme. METHODS: Incidence and mortality of ruptured AAA (RAAA) after 5 and 13 years of screening in a population based aneurysm screening program. RESULTS: Five years of screening resulted in a reduction in the incidence of RAAA of 49% (95% CI: 3-74%). Nine out of 11 ruptures in the invited group did not survive (mortality 82%; 95% CI: 48-98%) compared to 38 non-survivors from 51 ruptures in the control group (mortality 75%; 95% CI: 60-86%). Five years of screening resulted in an RAAA-related mortality reduction of 45% (95% CI: -15 to 74%). After 13 years of screening the incidence of RAAA was reduced by 73% (95% CI: 58-82%). Twenty-one out of 29 ruptures in the invited group did not survive (mortality 72%; 95% CI: 53-87%) compared to 64 non-survivors from 82 ruptures in the control group (mortality 78%; 95% CI: 68-86%). Thirteen years screening resulted in a reduction of mortality from RAAA of 75% (95% CI: 58-84%). The number needed to screen to prevent one death reduced from 1380 after 5 years to 505 after 13 years. The number of elective AAA operations needed to prevent one death reduced from 6 after 5 years to 4 after 13 years. CONCLUSION: AAA screening becomes increasingly beneficial as screening continues over the longer term. Benefits continue to increase after screening has ceased.

Perceptual asymmetries reflect developmental changes in the neuropsychological mechanisms of emotion recognition.

To study how perceptual asymmetries in the recognition of emotion reflect developmental changes in processing affective information, a fused rhyming dichotic word test with positive, negative, and neutral stimuli was administered to adults and children. Results suggested that the hemisphere in which affective information is initially processed affects the strength of perceptual asymmetry and that children's perceptual processing of emotional information is constrained by limited computational resources. Another experiment ruled out effects of volitional shifting of attention to emotional stimuli. These data further confirm that emotional processing involves integration of neural systems across brain regions, including distributed systems that support arousal and recognition. General developmental factors, such as processing capacity, contribute to the coordination of multiple systems responsible for processing emotional information.

Structural prerequisites for intersubtype B and D antigenicity of the third variable envelope region (V3) of human immunodeficiency virus type 1.

To elucidate the structural requirements for intersubtype antigenicity of human immunodeficiency virus type 1 (HIV-1) third variable envelope region (V3), synthetic peptides were used in enzyme immunoassays (EIAs) with serum samples from persons with proven or probable subtype B and D infections. Mathematical analyses of results from EIAs with singly substituted V3 peptides revealed important residues determining overall N-terminal V3 peptide antigenicity. This information was used to design V3 immunogens, rabbit antiserum to which were tested in EIA and for in vitro neutralization of molecular clones of HIV-1(MN) and HIV-1(MAL). Intersubtype-reactive epitopes were distributed toward the N-terminal half of the V3 loop. Lysine at position 310, arginine at position 311, and isoleucine at position 314, all derived from the MN primary sequence, were major determinants of intersubtype V3 antigenicity. Combinations of residues that enhanced antigenicity often contained lysine at position 310. Threonine at position 308 was common in the least advantageous combinations. V3 immunogens modified to achieve optimal antigenicity induced antiserum with augmented cross-neutralization of virus from MAL and MN molecular clones, suggesting one approach to subunit vaccine development.

Model misspecification effects within a family of alternative discrete reliability-growth models.

We describe a family of related discrete reliability-growth methodologies potentially applicable to one-shot systems undergoing a test-analyze-and-fix development process. The common feature shared by the models is their connection to Duane's renowned learning-curve property. The major difference, however, lies in their applicability in the context of two intrinsically different sampling schemes. For each model, a summary of the statistical properties of various estimators of the parameters as well as the reliability of the system, are reported. For purposes of assessing model misspecification, a particular text execution scenario conforming to a inverse sampling scheme is adopted. In reliability applications, it is not an uncommon practice to borrow inference results from models which are inappropriate in this setting. A detailed study of the potential impact of such misspecification on the estimation of system reliability is presented.

[Effects of mastectomy on dimensions of psychological and psychosocial experience and behavior of affected women]. / Die Auswirkungen der Mastektomie auf Dimensionen psychischen und psychosozialen Erlebens und Verhaltens betroffener Frauen.

The present study deals with the issue of how mastectomy will impact selected dimensions of psychological and psychosocial experience and behaviour in the women concerned. The study had comprised 21 women, mean age 55. 73 years, with a breast cancer diagnosis given between 1 and 21 years ago. Data collection was carried out using a 17-item questionnaire standardized for this purpose. Factor analyses produced four clearly interpretable factors. Study findings suggest that breast cancer surgery will not inevitably result in impaired sexual behaviour and experience in the affected women, whereas it is sure to impact, to varying degrees, on the factors and dimensions of "body image and self-image", "psychological and psychosomatic complaints" as well as anticipated "performance capacity and social relationships". Intercorrelations among questionnaire items are set out. It has further been found that the variables "time of breast removal" and "life age" had exercised only negligible influence on the women's questionnaire response, and that the psychosocial support experienced post-surgery was reported to have primarily come from the circle of family and friends, and less so been extended by self-help groups or medial staff. Concluding, the need for integrated rehabilitative measures is pointed out.

Effects of prenatal exposure to xylene on postnatal development and behavior in rats.

The effects of prenatal exposure to the organic solvent xylene (dimethylbenzene, CAS-no 1330-20-7) on postnatal development and behavior in rats were studied. Pregnant rats (Mol:WIST) were exposed to 500 ppm technical xylene 6 h per day on gestation days 7-20. The dose level was selected so as not to induce maternal toxicity or decrease the viability of offspring. In the exposed offspring, a delay in the ontogeny of the air righting reflex, a lower absolute brain weight, and impaired performance in behavioral tests for neuromotor abilities (Rotarod) and for learning and memory (Morris water maze) were found. Generally, the effects were most marked in the female offspring.

Two weeks inhalation exposure to 4-tert-butyltoluene causes persistent changes in visually evoked potentials in rats.

The effects of repeated exposure to 20 p.p.m. 4-tert-butyltoluene (CAS No. [98-51-1]) 6 hr/day for 14 days on the function of the intact nervous system were examined by measurements of flash evoked potentials in Wistar rats. The exposure to 4-tert-butyltoluene induced changes in the amplitudes of the flash evoked potentials. The changes were significantly different from controls on day 2, 19 and 26 after cessation of the exposure, but not on day 5 and 12. No significant difference in body weight gain between groups was found during the experiment. These results indicate that repeated exposure to 20 p.p.m. 4-tert-butyltoluene causes persistent changes in the function of the central nervous system measured as changes in the flash evoked potential. A reevaluation of the present TLV value of 10 p.p.m. for 4-tert-butyltoluene is suggested.

[Opinions of non-handicapped children about handicapped children--results of a survey in 2nd grade of elementary school]. / Meinungen nichtbehinderter Kinder über körperbehinderte Kinder--Ergebnisse einer Befragung in einer 2. Grundschulklasse.

It is pointed out in the initial theoretical considerations that comparatively few studies can be found in the pertinent literature that address the issue of younger non-disabled children's attitudes and behaviour toward children with physical disablement. The present study had comprised 23 second-year primary school-children (8 male, 15 female), age 7.6 to 8.6, from a community with a population of approx. 6000. At the time of our investigation, the subject of "disability" had not been explicitly dealt with at school, and the children moreover reported that they had not previously come into contact with disabled children either. The interviews were administered individually, using an interviewing structure of 19 questions pertaining to 7 different topics. Along with the findings for these 7 areas, the following can be summarized: The findings permit the conclusion that the majority of the children interviewed do not encounter disabled children in terms of an already manifest prejudiced behaviour. Restrictive opinions primarily have to do with functional limitations assumed to affect disabled children's abilities in play, are however unrelated to dimensions of the personality or a social behaviour that could entail rejection of the disabled child. On the other hand it was found that non-disabled children do anticipate the negative views held by others in their environment toward children with disabilities.

[Presentation of the "physical handicap" topic in six selected children's books--a critical analysis]. / Die Darstellung des Themenkreises "Körperbehinderung" in sechs ausgewählten Kinderbüchern--Eine kritische Analyse.

Since the late 60s, reality-oriented books for children and young people have increasingly turned to subject-matters and issues involving social/societal criticism, among them the theme of "being disabled". In the discussion on the degree to which media, and books in particular, do affect children's attitudes and socialization, it has been underlined that media take effect in the development of specific attitudinal patterns and behavioural dispositions in those cases where the recipient has not already formed a "completed" opinion of the topic at hand. This in particular is true in children of primary school age, and above all relates to their view of the disabled person. Six selected children's books were reviewed critically, based on a catalogue of criteria permitting coverage of as wide as spectrum as possible of "physical disability" and allied subjects. Summarizing, it is noted that the books reviewed do give children the opportunity, and partly in an excellent manner, of gaining insights into the situation of disabled persons. The potential for didactical treatment in primary classrooms is pointed out.

[Environmental access to a rehabilitation center as a determinant of attitude to handicapped persons? A comparative empirical study of assumptions of the "contact hypothesis"]. / Räumliche Nachbarschaft zu einem Behindertenzentrum als Determinante der Einstellungen gegenüber körperbehinderten Personen? Eine vergleichende empirische Studie zu Annahmen der "Kontakthypothese".

A total of 263 respondents were interviewed relative to their attitudes towards disabled persons, using a standardized questionnaire. Of these 263 subjects, 144 lived in a community without any facility for disabled persons in the vicinity, 119 subjects lived close by a physically disabled persons centre. The "attitudinal climate" among all interviewees on the whole more on the positive side, it was found that those living in the vicinity of a physically disabled persons centre, though expressing less contact uneasiness when meeting physically handicapped children and young people, did however not give more positive--but neither more negative--opinions in other respects than those subjects not living near a facility for the disabled. The results obtained were further analyzed on the variables of age, sex, and closer contacts with disabled people among friends. It has, once again, been confirmed that attitudes toward disabled persons constitute a multidimensional construct that, to varying degrees, is influenced by a number of factors. Some consequences and considerations in terms of educational implementation possibilities of the findings are outlined in conclusion.