Homogenization of dislocation dynamics

In this paper we consider the dynamics of dislocations with the same Burgers vector, contained in the same glide plane, and moving in a material with periodic obstacles. We study two cases: i) the particular case of parallel straight dislocations and ii) the general case of curved dislocations. In each case, we perform rigorously the homogenization of the dynamics and predict the corresponding effective macroscopic elasto-visco-plastic flow rule

Re-Emerging Vaccine-Preventable Diseases in War-Affected Peoples of the Eastern Mediterranean Region\u2014An Update

For the past few decades, the Eastern Mediterranean Region has been one area of the world profoundly shaped by war and political instability. On-going conflict and destruction have left the region struggling with innumerable health concerns that have claimed the lives of many. Wars, and the chaos they leave behind, often provide the optimal conditions for the growth and re-emergence of communicable diseases. In this article, we highlight a few of the major re-emerging vaccine preventable diseases in four countries of the Eastern Mediterranean Region that are currently affected by war leading to a migration crisis: Iraq, South Sudan, Syria, and Yemen. We will also describe the impact these infections have had on patients, societies, and national health care services. This article also describes the efforts, both local and international, which have been made to address these crises, as well as future endeavors that can be done to contain and control further devastation left by these diseases

Role of per-oral pancreatoscopy in the evaluation of suspected pancreatic duct neoplasia: a 13-year U.S. singlecenter experience

Background and Aims The role of per-oral pancreatoscopy (POP) in the evaluation of occult pancreatic duct (PD) lesions remains limited to case series. The aim of this study was to evaluate the ability of POP to differentiate malignant from benign diseases of the PD. Methods Patients who underwent POP between 2000 and 2013 for the evaluation of indeterminate PD strictures, dilatations, or with suspected or known main duct intraductal papillary mucinous neoplasm were identified. Main outcome measurements were visual impression accuracy, POP tissue sampling, efficacy, and safety of POP. Results During the study period, 79 patients who underwent POP for the evaluation of pancreatic stricture or dilatation were identified. Technical success was achieved in 78 (97%). In the PD neoplasia group (n = 33), the final diagnosis was based on index confirmatory POP-guided tissue sampling in 29 (88%). For the detection of PD neoplasia, POP visual impression had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 87%, 86%, 83%, 91%, and 87%, respectively. When combined with POP-guided tissue sampling, the values were 91%, 95%, 94%, 93%, and 94%, respectively. Of 102 POPs performed, adverse events were noted in 12 (12%) cases. Conclusions This study demonstrates a high technical success rate, visual impression accuracy, and tissue sampling capability of POP. Examinations were performed by endoscopists with expertise in pancreatoscopy interpretation, and the results may not be generalizable

Autologous whole ram seminal plasma and its vesicle-free fraction improve motility characteristics and membrane status but not in vivo fertility of frozen-thawed ram spermatozoa

Motility characteristics (assessed subjectively and with computer-assisted semen analysis) and membrane status (after staining with chlortetracycline) of washed and non-washed frozen-thawed ram spermatozoa were evaluated after incubation in buffer and buffer containing autologous whole seminal plasma or one of its two fractions: the pellet of membrane vesicles obtained by ultracentrifugation (and used at three times normal protein concentration) or the vesicle-free supernatant fraction. Whole seminal plasma and supernatant, but not membrane vesicles, improved the motility characteristics of spermatozoa after 3 and 6 h of post-thaw incubation compared with the control buffer. Resuspension and incubation with whole seminal plasma, supernatant or membrane vesicles lowered the proportion of acrosome-reacted frozen-thawed spermatozoa compared with the control buffer. Unwashed frozen-thawed semen from three rams, incubated with autologous whole seminal plasma or its fractions and inseminated using cervical or intrauterine artificial insemination, had no effect on pregnancy rates of ewes in synchronized oestrus. However, fertility was higher after laparoscopic than cervical insemination (44.9 vs 12.3%, p < 0.001). In conclusion, resuspension and incubation of frozen-thawed ram spermatozoa in autologous whole seminal plasma or its vesicle-free supernatant fraction improved their motility characteristics and, with membrane vesicles, membrane status, but these benefits were not reflected in improved fertility after cervical or intrauterine insemination. © 2007 The Authors

Global existence for a system of non-linear and non-local transport equations describing the dynamics of dislocation densities

In this paper, we study the global in time existence problem for the Groma-Balogh model describing the dynamics of dislocation densities. This model is a two-dimensional model where the dislocation densities satisfy a system of transport equations such that the velocity vector field is the shear stress in the material, solving the equations of elasticity. This shear stress can be expressed as some Riesz transform of the dislocation densities. The main tool in the proof of this result is the existence of an entropy for this syste

Th-232 Radiological Aspects of Carbonate Niobium Mining Waste Use as Agricultural Amendment

The use of mining residues in agriculture may be possible, as long as there be previous studies in different areas, one of them being the analysis of the involved radionuclides behavior. This study determined the concentrations of 232Th activity in soil, soil treated with lime, soil with carbonate residue from niobium mining, soil with the mixture of lime and carbonate, in two moments. The transfer factor of 232Th from the soil to the plant was analyzed, in this case, lettuce (n=20), in the different types of treatment and in two moments. The addition of carbonate to the soils did not significantly alter the levels of radioactivity for 232Th radionuclide in lettuce. The effective dose resulting from the lettuce ingestion varied from 0.09 to 0.3 µSv y-1