Chitinase isolated from water and soil bacteria in shrimp farming ponds

Chitinases have received attention because of their wide applications in the medicine, biotechnology, agriculture, waste management and industrial applications such as food quality enhancer and biopesticide. Excessive use of insecticides has led to several problems related to pollution and environmental degradation. In this study, isolation and identification of native bacterial strains with chitin hydrolysis activity, took place from water and soil of shrimp culture ponds in Bushehr and Abadan. To investigate the capacity of our chitinase for using in insecticide, biochemical properties of selected chitinase obtained in this research were compared to that of produced by Bacillus cereus p-1, isolated from an insecticide tablet. In this research, three mesophilic strains containing: Serratia marcescens B4A, Citrobacter freundii B1A and Bacillus cereus B3R were isolated. Results showed a 1600 bp band corresponding to chitinase gene. The similarity between temperature and pH profile and stability of chitinase was extracted from native bacteria and ones was obtained from Bacillus cereus p-1 implied that chitinase extracted from Serratia marcescens B4A has potential application in industry

Length-weight and length-length relationships, relative condition factor and Fulton’s condition factor of five Cyprinid species in Anzali wetland, southwest of the Caspian Sea

This study was conducted to determine length-weight and length-length relationships, relative condition factor (Krel) and Fulton’s condition factor (K) for five species including Scardinius erythrophtalmus, Carassius auratus gibelio, Cyprinus carpio, Tinca tinca and Hemiculter leucisculus belonging to Cyprinidae family. Fish sampling was carried out by gill net and fyke net in the western region of Anzali wetland (SW of the Caspian Sea) between Nov. 2010 and May 2011. 368 specimens were measured and weighed. The values of the exponent b in the length-weight relationships (LWRs) ranged from 2.5358 to 3.3613 and those of the length-length relationship (LLRs) ranged from 0.8717 to 0.9412. Also, relative condition factor (Krel) ranged from 1.00±0.11 to 1.30±0.21 and Fulton’s condition factor (K) ranged from 0.80±0.05 to 1.60±0.18 for all species

Magneto-hydrodynamics of couple stress lubricants in combined squeeze and shear in parallel annular disc viscous coupling systems

This article presents predictive analysis of load-carrying capacity, tractive efficiency and response time of parallel annular discs intervened with a film of lubricant under combined shear and squeeze film motions. This configuration represents operational characteristics of viscous coupling systems. In particular, the case of viscous dampers for tractive torque generation and distribution in all-wheel-drive off road vehicles is studied. Various forms of lubricant behaviour, from idealised Newtonian to that of non-Newtonian silicone-based fluids and incompressible isothermal electrically conducting couple stress fluids, subjected to a magneto-hydrodynamic field are studied. The solution for the magneto-hydrodynamics includes combined solution of modified Reynolds equation and Stoke's micro-continuum for couple stress fluids in squeeze and shear with rotational fluid inertia, an approach not hitherto reported in the literature. It is shown that in general magneto-hydrodynamic couple stress fluids enhance the load-carrying capacity of the contact and inhibit the incidence of thin films, which can result in direct contact of surfaces. Rotational inertia decreases the load-carrying capacity, although in general the magneto-hydrodynamic fluids show better load-carrying capacity and tractive efficiency than the other alternatives. However, they exhibit a lower response time under the assumed isothermal condition. Nevertheless, the magneto-hydrodynamic fluids are best suited to applications in viscous coupling systems because of their controllability

Nuclear maturation of immature bovine oocytes after vitrification using open pulled straw and cryotop methods

To date, at least two well known methods have been widely used for vitrification of oocytes and embryos at different stages in a variety of species. However, there is no reported data regarding the comparative effectiveness of these two methods for vitrification of immature bovine oocytes. The objective of this study is to compare the nuclear maturation of immature bovine oocytes vitrified using open pulled straw (OPS) and cryotop methods. Two experiments were conducted in this study. In the first experiment, cytotoxicity of vitrification solutions (VS) from both methods was studied. After removal of cryoprotectants, cumulus oocyte complexes (COCs) was cultured in vitro and cleavage rate was monitored on Day 2 post-insemination (pi), whereas, morulae and blastocyst yields on Days 5 and 8 pi, respectively. The VS solutions significantly reduced zygotic cleavage rate, morulae and blastocyst rates compared with the control group (P < 0.05). The lowest cleavage rate resulted from prolonged exposure time to OPS-VS solutions (35.1%; P < 0.05). However, the morulae and blastocyst rates were significantly higher (P < 0.05) for embryos derived from oocytes exposed to cryotop solutions (40.5 and 22.4%, respectively). In the second experiment, effectiveness of both vitrification methods was compared for cryopreservation of immature bovine oocytes. After warming, COCs were cultured in vitro for 24 h. The polar body (PB+) and metaphase-II (MII) stage rates differed significantly among treatment groups. Oocytes vitrified using cryotop solution and device showed higher percentages of PB+ (36%) and MII (51%) rates. In addition, the lowest percentage of degenerated oocytes resulted from cryotop solution. The highest degenerated oocytes obtained by equilibration in OPS solution and vitrified using OPS device (40%; P < 0.05). In conclusion, our data demonstrated that cryotop solution was less toxic to the immature bovine oocytes and vitrification with the cryotop method resulted in higher survival and nuclear maturation rates.Key words: Immature oocyte, bovine, vitrification, cryotop, open pulled straw (OPS)

Difficult weaning from cardiopulmonary bypass after surgical VSD closure: An unusual rare case

The connection of the left coronary artery to the pulmonary artery may be asymptomatic due to high pulmonary vascular resistance in the context of left-to-right shunts. Before the repair of the mentioned anomalies, coronary anatomy must be defined. © 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd

A quantitative meta-analysis and qualitative meta-synthesis of aged care residents’ experiences of autonomy, being controlled, and optimal functioning

Background and Objectives The poor mental health of adults living in aged care needs addressing. Improvements to nutrition and exercise are important, but mental health requires a psychological approach. Self-determination theory finds that autonomy is essential to wellbeing while experiences of being controlled undermine it. A review of existing quantitative data could underscore the importance of autonomy in aged care, and a review of the qualitative literature could inform ways to promote autonomy and avoid control. Testing these possibilities was the objective of this research. Research Design and Methods We conducted a mixed-methods systematic review of studies investigating autonomy, control, and indices of optimal functioning in aged care settings. The search identified 30 eligible reports (19 quantitative, 11 qualitative), including 141 quantitative effect sizes, 84 qualitative data items, and N = 2,668. Quantitative effects were pooled using three-level meta-analytic structural equation models, and the qualitative data were meta-synthesized using a grounded theory approach. Results As predicted, the meta-analysis showed a positive effect of aged care residents’ autonomy and their wellness, r = 0.33 [95% CI: 0.27, 0.39], and a negative effect of control, r = −0.16 [95% CI: −0.27, −0.06]. The meta-synthesis revealed seven primary and three sub-themes describing the nuanced ways autonomy, control, and help seeking are manifest in residential aged care settings. Discussion and Implications The results suggest that autonomy should be supported, and unnecessary external control should be minimized in residential aged care, and we discuss ways the sector could strive for both aims