Studies on improvement of the productivity of Turkish Angora goats by crossing with South African Angora goats

The three leading countries in the world in rearing Angora goats are Turkey, the USA and the Republic of South Africa. in order to improve the important yield characteristics of Turkish Angora goats by using North American gene sources, studies have been carried out since 1982. In this study, the effect of South African genotype on Turkish Angora goats was investigated. During the study, a total of 187 pure Turkish Angora goats (TT) were intra-vaginally inseminated with frozen semen and 79 (42.25%) goats conceived and kidded. There was no significant difference between the birth weights of kids of TT and F-1 crossbred (South African x Pure Turkish) groups (2.76 and 2.72kg). There was an increase in favour of F-1 crossbreds at 105th day weaning weights (14.48 and 15.42 kg) and 6th month weights (20.39 and 21.99 kg). The liveweights of does after shearing (in spring) and before insemination (in autumn) were similar in both genotypes. The mohair yields of female goats at various age were 2.44 kg in TT group and 2.55 kg in F-1 crossbred group (P < 0.05). The effect of genotype on birth weights of kids and mohair yields of does was statistically significant (P < 0.05) but not significant for other characteristics. Therefore, it is suggested that crossing with a South African genotype can improve the mohair yield of Turkish Angora goats

Scheduling with tool changes to minimize total completion time: Basic results and SPT performance

We consider a single machine sequencing problem subject to tool wear, where the objective is to minimize the total completion time. We briefly describe the problem and discuss its properties, complexity and solution. Mainly, however, we focus on the performance of the SPT list-scheduling heuristic. We provide theoretical worst-case bounds on SPT performance and also demonstrate its empirical behavior

Scheduling With Tool Changes to Minimize Total Completion Time; A Study of Heuristics and Their Performance

The machine scheduling literature does not consider the issue of tool change. The parallel literature on tool management addresses this issue but assumes that the change is due only to part mix. In practice, however, a tool change is caused most frequently by tool wear. That is why we consider here the problem of scheduling a set of jobs on a single CNC machine where the cutting tool is subject to wear; our objective is to minimize the total completion time. We first describe the problem and discuss its peculiarities. After briefly reviewing available theoretical results, we then go on to provide a mixed 0-1 linear programming model for the exact solution of the problem; this is useful in solving problem instances with up to 20 jobs and has been used in our computational study. As our main contribution, we next propose a number of heuristic algorithms based on simple dispatch rules and generic search. We then discuss the results of a computational study where the performance of the various heuristics is tested; we note that the well-known SPT rule remains good when the tool change time is small but deteriorates as this time increases and further that the proposed algorithms promise significant improvement over the SPT rule

Effect of Disulfide Bonds on the Thermal Stability of Pediocin: In-silico Screening Using Molecular Dynamics Simulation

The thermal stability properties of pediocin at 310, 313, 323, 333, 343, and 348 K (37, 40, 50, 60, 70, and 75°C, respectively) are reported in this study. A theoretical approach, such as the molecular dynamics method, was used to analyze the structure. Molecular dynamics simulation confirms the stability of molecules with Cys. Furthermore, this study reveals that Cys residues play an essential role in structure stability at high temperatures. To understand the structural basis for the stability of pediocin, a detailed in-silico analysis using molecular dynamics simulations to explore the thermal stability profiles of the compounds was conducted. This study shows that thermal effects fundamentally alter the functionally crucial secondary structure of pediocin. However, as previously reported, pediocin’s activity was strictly conserved due to the disulfide bond between Cys residues. These findings reveal, for the first time, the dominant factor behind the thermodynamic stability of pediocin

Antibiotic and Bacteriocin Sensitivity of &lt;i&gt;Listeria monocytogenes&lt;/i&gt; Strains Isolated from Different Foods

This study aimed to determine the antibiotic and bacteriocin sensitivity of Listeria monocytogenes strains isolated from animal derived foods. With disc diffusion assay, all fourteen L. monocytogenes strains were suscepti-ble to the antibiotics, including penicillin G, vancomycin, tetracycline, chloramphenicol, rifampicin, erythromycin, gentamicin and trime- thoprim. However, the percentages of fosfomycin and streptomycin resistances were 92.9% and 7.1%, respectively. Multiple resistances were not observed among the tested strains. The results of well diffusion assays showed that all strains were inhibited by the cell-free supernatant of a bacteriocin-producing strain, Pediococcus acidilactici 13, with the inhibition zones ranging from 16.00 to 24.50 mm. These results provide useful information on antibiotic resistance of L. monocytogenes strains isolated from foods, and can potentially be used to develop bacteriocin-based interventions to guard against the hazards associated with L. monocytogenes in ready-to-eat meat and poultry products