Multidimensional simple waves in fully relativistic fluids

A special version of multi--dimensional simple waves given in [G. Boillat, {\it J. Math. Phys.} {\bf 11}, 1482-3 (1970)] and [G.M. Webb, R. Ratkiewicz, M. Brio and G.P. Zank, {\it J. Plasma Phys.} {\bf 59}, 417-460 (1998)] is employed for fully relativistic fluid and plasma flows. Three essential modes: vortex, entropy and sound modes are derived where each of them is different from its nonrelativistic analogue. Vortex and entropy modes are formally solved in both the laboratory frame and the wave frame (co-moving with the wave front) while the sound mode is formally solved only in the wave frame at ultra-relativistic temperatures. In addition, the surface which is the boundary between the permitted and forbidden regions of the solution is introduced and determined. Finally a symmetry analysis is performed for the vortex mode equation up to both point and contact transformations. Fundamental invariants and a form of general solutions of point transformations along with some specific examples are also derived.Comment: 21 page

Reproductive maturation of sub adult Indian carps in earthen ponds

Carp culture in extensive and semi-extensive systems: i.e., earthen ponds, natural and semi-natural water resources, reservoirs and the paddy field has widspred distribution. Indian major carps including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) which have faster growth and good feed value than other warm water fishes introduced to many countries including India, Thailand, Burma, Philippines, Japan and the former Soviet Union are also considered and are reared. Sex steroids are important in the control of reproduction in fish. Development of methods for Indian education programs for proliferation requires knowledge of the hormonal changes during sexual maturation and spawning is. Testosterone, progesterone and 17 ϐ-estradiol are steroid hormones that play an important role in controlling Tuesday reproduction and sexual maturity of the fish are. This study aimed to investigate the changes in steroid hormones testosterone and 17 beta-estradiol including Catla (Catla catla), Roho (Labeo rohita), Mrigal (Cirrhinus mirgala) were conducted in different seasons. 40 specimen of carps breeders were investigated in southern (Aquaculture Research Institute) and north (North Aquaculture Research Institute) of Iran and maintained in different seasons (spring, summer, autumn, winter). Fish were caught by netting vetch and spring 1 cm. Blood samples were collected from the fish caudal blood serum by centrifugal separation model Labofuga 200 was made in Germany. Testosterone, and estradiol RIA (Radioimmunoassy) using an automatic gamma counter LKB model made in Finland made in France using the Immunotech kit hormone were measured. The results showed that the average level of 17 betaestradiol in the female in the spring, summer, autumn and winter, respectively, 82/12 ± 75/107, 66/13 ± 2/80, 73/17 ± 8/122 and 72/17 ± 25/104 ml, respectively. Mean testosterone levels in the female in the spring, summer, autumn and winter, respectively, 004/0 ± 092/0, 002/0 ± 05/0, 003/0 ± 11/0 and 006/0 ± 1/0 ng ml, respectively. Overall, the highest levels of 17 beta-estradiol and testosterone in female Roho were recorded in autumn. Also, low levels of 17 beta-estradiol and testosterone in female Roho was observed in summer. Highest and lowest levels of the male hormone, respectively, were recorded in winter and spring. The relationship between the hormone 17 beta-estradiol and testosterone with environmental factors such as pH and dissolved oxygen were discussed. there was a positive correlation between testosterone levels in males only the amount of dissolved oxygen .results revieled that sex hormone levels were increased during winter and autumn would be the signe for reproductive performance and spawning seasone in three species

30-day Morbidity and Mortality after Cholecystectomy for Benign Gallbladder Disease (AMBROSE): A Prospective, International Collaborative Cohort Study

Objective:This study aimed to assess 30-day morbidity and mortality rates following cholecystectomy for benign gallbladder disease and identify the factors associated with complications.Background:Although cholecystectomy is common for benign gallbladder disease, there is a gap in the knowledge of the current practice and variations on a global level.Methods:A prospective, international, observational collaborative cohort study of consecutive patients undergoing cholecystectomy for benign gallbladder disease from participating hospitals in 57 countries between January 1 and June 30, 2022, was performed. Univariate and multivariate logistic regression models were used to identify preoperative and operative variables associated with 30-day postoperative outcomes.Results:Data of 21,706 surgical patients from 57 countries were included in the analysis. A total of 10,821 (49.9%), 4263 (19.7%), and 6622 (30.5%) cholecystectomies were performed in the elective, emergency, and delayed settings, respectively. Thirty-day postoperative complications were observed in 1738 patients (8.0%), including mortality in 83 patients (0.4%). Bile leaks (Strasberg grade A) were reported in 278 (1.3%) patients, and severe bile duct injuries (Strasberg grades B-E) were reported in 48 (0.2%) patients. Patient age, American Society of Anesthesiologists physical status class, surgical setting, operative approach, and Nassar operative difficulty grade were identified as the 5 predictors demonstrating the highest relative importance in predicting postoperative complications.Conclusions:This multinational observational collaborative cohort study presents a comprehensive report of the current practices and outcomes of cholecystectomy for benign gallbladder disease. Ongoing global collaborative evaluations and initiatives are needed to promote quality assurance and improvement in cholecystectomy

Automated Laser Ultrasonic Inspection of Hybrid Laser Arc Welding for Pipeline Construction

Hybrid laser arc welding (HLAW) is a technology that promises to increase the efficiency of welded fabrication. By incorporating automation, and integrating an automated inspection system, HLAW can produce high quality welds at higher production rates and lower costs compared to even the most advanced pipeline welding system that is in use today. As the HLAW technique is developed and implemented for pipeline construction, it is important to develop an associated automated technique for weld inspection. We have applied automated laser ultrasonic testing (ALUT) to the important requirement of the in-line monitoring of new HLAW welds in the field. Laser ultrasonic testing (LUT) offers the advantage of true in-process measurement, providing immediate information on weld integrity. In this paper, we will describe our efforts to apply LUT to pipeline girth weld inspection. The technology development process and the integration into an HLAW system will be described.</jats:p