Evolution of an elliptical bubble in an accelerating extensional flow

Mathematical models that describe the dynamical behavior of a thin gas bubble embedded in a glass fiber during a fiber drawing process have been discussed and analyzed. The starting point for the mathematical modeling was the equations presented in [1] for a glass fiber with a hole undergoing extensional flow. These equations were reconsidered here with the additional reduction that the hole, i.e. the gas bubble, was thin as compared to the radius of the fiber and of finite extent. The primary model considered was one in which the mass of the gas inside the bubble was fixed. This fixed-mass model involved equations for the axial velocity and fiber radius, and equations for the radius of the bubble and the gas pressure inside the bubble. The model equations assumed that the temperature of the furnace of the drawing tower was known. The governing equations of the bubble are hyperbolic and predict that the bubble cannot extend beyond the limiting characteristics specified by the ends of the initial bubble shape. An analysis of pinch-off was performed, and it was found that pinch-off can occur, depending on the parameters of the model, due to surface tension when the bubble radius is small. In order to determine the evolution of a bubble, a numerical method of solution was presented. The method was used to study the evolution of two different initial bubble shapes, one convex and the other non-convex. Both initial bubble shapes had fore-aft symmetry, and it was found that the bubbles stretched and elongated severely during the drawing process. For the convex shape, fore-aft symmetry was lost in the middle of the drawing process, but the symmetry was re-gained by the end of the drawing tower. A small amount of pinch-off was observed at each end for this case, so that the final bubble length was slightly shorter than its theoretical maximum length. For the non-convex initial shape, pinch-off occurred in the middle of the bubble resulting in two bubbles by the end of the fiber draw. The two bubbles had different final pressures and did not have fore-aft symmetry. An extension of the fixed-mass model was considered in which the gas in the bubble was allowed to diffuse into the surrounding glass. The governing equations for this leaky-mass model were developed and manipulated into a form suitable for a numerical treatment

Neuroticism as an antecedent of abusive supervision and laissez-faire leadership in emergent leaders: The role of facets and agreeableness as a moderator

Academic interest in the relationship between leaders' personality and subordinates’ perception of destructive leadership behavior is increasing. However, results so far have been weak, contradictory, and inconsistent to theory. Here, we examine if using facets of neuroticism, rather than the broader trait, can be more informative and increases the predictive power. Next, we explore the interplay between personality dimensions by examining if the relationship between the facet angry hostility in neuroticism and destructive leadership behavior is moderated by the trait agreeableness. Four hundred and twenty emergent leaders were examined in a military selection context, combining the leaders' self-rated neuroticism (T1) with subordinates' subsequent perception of abusive supervision and laissez-faire leadership in a field exercise two weeks later (T2). The results indicated that using facets instead of the broad factor of neuroticism improved the prediction of examined outcomes. Only some of the facets of neuroticism were related to perceived leader behavior, with specific facets being identified for abusive supervision and laissez-faire leadership, respectively. Further, the relationship between angry hostility and both leadership styles was moderated by agreeableness.publishedVersio

Evaluating Translational Methods for Personalized Medicine—A Scoping Review

The introduction of personalized medicine, through the increasing multi-omics characterization of disease, brings new challenges to disease modeling. The scope of this review was a broad evaluation of the relevance, validity, and predictive value of the current preclinical methodologies applied in stratified medicine approaches. Two case models were chosen: oncology and brain disorders. We conducted a scoping review, following the Joanna Briggs Institute guidelines, and searched PubMed, EMBASE, and relevant databases for reports describing preclinical models applied in personalized medicine approaches. A total of 1292 and 1516 records were identified from the oncology and brain disorders search, respectively. Quantitative and qualitative synthesis was performed on a final total of 63 oncology and 94 brain disorder studies. The complexity of personalized approaches highlights the need for more sophisticated biological systems to assess the integrated mechanisms of response. Despite the progress in developing innovative and complex preclinical model systems, the currently available methods need to be further developed and validated before their potential in personalized medicine endeavors can be realized. More importantly, we identified underlying gaps in preclinical research relating to the relevance of experimental models, quality assessment practices, reporting, regulation, and a gap between preclinical and clinical research. To achieve a broad implementation of predictive translational models in personalized medicine, these fundamental deficits must be addressed.publishedVersio

Analysis of chromosome positions in the interphase nucleus of Chinese hamster cells by laser-UV-microirradiation experiments

Unsynchronized cells of an essentially diploid strain of female Chinese hamster cells derived from lung tissue (CHL) were laser-UV-microirradiated (=257 nm) in the nucleus either at its central part or at its periphery. After 7–9 h postincubation with 0.5 mM caffeine, chromosome preparations were made in situ. Twenty-one and 29 metaphase spreads, respectively, with partial chromosome shattering (PCS) obtained after micro-irradiation at these two nuclear sites, were Q-banded and analyzed in detail. A positive correlation was observed between the frequency of damage of chromosomes and both their DNA content and length at metaphase. No significant difference was observed between the frequencies of damage obtained for individual chromosomes at either site of microirradiation. The frequency of joint damage of homologous chromosomes was low as compared to nonhomologous ones. Considerable variation was noted in different cells in the combinations of jointly shattered chromosomes. Evidence which justifies an interpretation of these data in terms of an interphase arrangement of chromosome territories is discussed. Our data strongly argue against somatic pairing as a regular event, and suggest a considerable variability of chromosome positions in different nuclei. However, present data do not exclude the possibility of certain non-random chromosomal arrangements in CHL-nuclei. The interphase chromosome distribution revealed by these experiments is compared with centromere-centromere, centromere-center and angle analyses of metaphase spreads and the relationship between interphase and metaphase arrangements of chromosomes is discussed

Cerebral microembolization during off-pump coronary artery bypass surgery with the Symmetry aortic connector device

ObjectiveThe use of aortic connector systems for proximal vein grafts in off-pump coronary artery bypass grafting might minimize aortic manipulation by eliminating the need for partial aortic clamping. The objective of this study was to asses whether use of a Symmetry connector (St Jude Medical, Inc, St Paul, Minn) reduced intraoperative cerebral embolization.MethodsThirty-two consecutive patients underwent off-pump coronary artery bypass grafting. Sixteen patients received at least one mechanical proximal vein graft anastomosis with a Symmetry aortic connector system. Sixteen patients representing the control group underwent operations with standard suturing techniques using partial aortic clamping. During surgical intervention, all patients were monitored continuously with multifrequency transcranial Doppler scanning, which detected and differentiated cerebral emboli.ResultsThere were significantly more cerebral emboli in the Symmetry group (median, 36) compared with the control group (median, 11; P = .027). This was due to a higher number of gaseous emboli in the Symmetry group than in the control group (median, 27 vs 8; P = .014), whereas there was no significant difference regarding the number of solid emboli (median, 7 vs 3; P = .139).ConclusionUse of a Symmetry connector system during proximal vein graft anastomosis increased the number of emboli to the brain compared with a standard technique in coronary bypass surgery without cardiopulmonary bypass

CD24-targeted intraoperative fluorescence image-guided surgery leads to improved cytoreduction of ovarian cancer in a preclinical orthotopic surgical model

Background: The completeness of resection is a key prognostic indicator in patients with ovarian cancer, and the application of tumour-targeted fluorescence image-guided surgery (FIGS) has led to improved detection of peritoneal metastases during cytoreductive surgery. CD24 is highly expressed in ovarian cancer and has been shown to be a suit

Doctoral Student Perspectives on Motivation and Persistence: Eye-Opening Insights Into the Ideas and Thoughts That Today\u27s Doctoral Students Have About Finishing the Doctoral Degree

It all comes down to this: we have an amazing team of faculty working with us who are present, supportive, intelligent, and motivated to help us succeed. They designed this program with those objectives in mind. We are in good hands, and any questions we have will be answered, so long as we ask them. Having the support system of our faculty, along with the tools we need to be successful, are major parts of the battle, already won. The rest is up to us. - A. Brooke Boultonhttps://openriver.winona.edu/educationeddbooks/1000/thumbnail.jp

Trends in childhood type 1 diabetes incidence in France, 2010 - 2015

AIMS: To estimate type 1 diabetes incidence in children in France and its evolution between 2010 and 2015, based on comprehensive medico-administrative databases. METHODS: The algorithm built to identify new cases of type 1 diabetes selected children aged between 6 months and 14 years who had at least one hospital stay for diabetes, followed by their first insulin treatment, excluding children suffering from another form of diabetes. Age and sex specific annual incidence rates were estimated and time trend was analyzed using Poisson regression. RESULTS: A total of 12 067 children were identified as newly diagnosed with type 1 diabetes and the annual incidence rates increased between 2010 and 2015 (from 15.4 [95% Confidence Interval: 14.7;16.1] to 19.1 [18.3;19.9] per 100 000 person-years), among boys and girls, and in each age group (4 and under, 5 - 9, 10 - 14 year olds). The annual rate of increase was 4.0% [3.4;4.6]. This trend was not significantly different between each gender, and each age group. CONCLUSIONS: Valid database information on disease incidence is essential for healthcare planning and provides a valuable resource for health research. An increase of the incidence rate of type 1 diabetes in children was highlighted in both sexes and in all age groups