Minimizing sum of completion times on a single machine with sequence-dependent family setup times

This paper presents a branch-and-bound (B&B) algorithm for minimizing the sum of completion times in a singlemachine scheduling setting with sequence-dependent family setup times. The main feature of the B&B algorithm is a new lower bounding scheme that is based on a networkformulation of the problem. With extensive computational tests, we demonstrate that the B&B algorithm can solve problems with up to 60 jobs and 12 families, where setup and processing times are uniformly distributed in various combinations of the [1,50] and [1,100] ranges

Effects of dietary fish oil and flax seed on cholesterol and fatty acid composition of egg yolk and blood parameters of laying hens

This study was conducted to determine the effects of the supplementation of different levels of fish oil (FO) and flax seed (FS) in the diets of layers on the content of egg yolk fatty acid, cholesterol, blood parameters, egg production and egg quality criteria. In the experiment, a total of 120 Isa-White laying hens of 34 weeks of age were used. Hens were divided randomly into five groups and fed different diets containing no FO and FS; 1.5% FO; 4.32% FS; 1.5% FO+4.32% FS and 8.64% FS for eight weeks. A significant decrease in yolk cholesterol content (mg/g yolk) was found in the eggs from hens fed the diets containing 1.5 % FO and 8.64% FS as compared with the control. Adding FO and FS to diets significantly increased the total omega-3 fatty acids in eggs at 28 (phase 1) and 56 (phase 2) days of the trial. By contrast, the addition of both FO and FS to diets had no effect on total omega-6 fatty acids in eggs in phase 1. But dietary 1.5% FO, 4.32% FS and 1.5% FO+4.32% FS supplementation decreased significantly the total omega-6 fatty acids compared to the controls in phase 2. The linolenic acid content of eggs was the highest in eggs from hens fed the diet with added FS, while docosahexaenoic acid content was the highest in eggs from hens fed diets with added FO. Dietary supplementation of FO and FS did not significantly affect the concentrations of serum trigliceride and high density lipoprotein. The serum cholesterol level of hens fed diets containing 1.5% FO+4.32% FS and 8.64% FS was lower than the control group. The addition of FO and FS to diets did not cause any negative effect on some egg quality criteria such as egg weight, yolk weight, yolk ratio, albumen weight, albumen ratio, shell weight, shell ratio, shell strength and shell thickness. The egg production of hens fed a diet containing 4.32% FS was significantly higher than the controls. Feed intake and feed conversion were not affected by all treatments. Keywords: Omega-3 fatty acids, Cholesterol eggs, Flax seed, Fish oil South African Journal of Animal Science Vol.33(4) 2003: 266-27

Consumer exposure to biocides - identification of relevant sources and evaluation of possible health effects

<p>Abstract</p> <p>Background</p> <p>Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted.</p> <p>Methods</p> <p>Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined.</p> <p>Results</p> <p>Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies.</p> <p>Conclusions</p> <p>Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive.</p

Titres of naturally occurring alloantibodies against feline blood group antigens in Turkish Van cats

WOS: 000222248900002PubMed: 15206473Seventy-eight Turkish Van cats were examined for alloantibody titres, of which 42.3 per cent had type A blood and 57.7 per cent had type B blood. No type AB cats were found. All type B cats (n=45) showed gross evidence of agglutinating anti-A antibody, with titres ranging from 2 to 256. Sixty-seven per cent of type B cats had anti-A antibody in their plasma, with titres ranging from 8 to 32. However, 13 per cent of type B cats had plasma alloantibody titres of less than 8 and 20 per cent had titres that were higher than 32. A total of 33 type A cats were also tested for anti-B alloantibody titres in their plasma. Among the type A plasma, gross agglutination at titres of 2 and greater than 2 were determined in 24 per cent and 36 per cent of samples, respectively. Microscopic agglutination was seen in an additional 18 per cent of plasma samples. There was no significant association between gender and plasma alloantibody titres of cats (P>0.05)

Antibiotic levels and heavy metal resistance in gram-negative bacteria isolated from seawater, Iskenderun organized industrial zone

Gram-negative bacteria were isolated from the territorial seawater of Iskenderun Organized Industrial Zone in Iskenderun Bay, to measure their resistance levels against to antibiotic and heavy metal. Sixteen species of bacteria were identified by using VITEK II System. Total of 18 antibiotics disc and four heavy metals were applied for the resistance test. Antibiotic resistances of all isolates were at high percentages for eritromisine (94.4%), ampicilline (72.7%), streptomycin (68.3%), cefazolin (64.6%) and carboksipeneme (57.1%). The highest resistant strain was resistant against to 17 antibiotics, while the weakest resistant of two isolates were sensitive to all antibiotics. MAR index values were found to be higher than 0.2 for 94.9% of all isolates. Heavy metal resistances of all isolates were found to be in high percentages as 100% for cadmium, %100 for copper, 90.7% for manganese, and 67.7 % for lead. High resistances of examined bacteria against to both antibiotics and heavy metals indicated a dense and multisource pollution in the bay. The pollution in territorial waters of the bay may threat the aquatic life consequently, the public health

Effect of Yucca schidigera and natural zeolite on broiler performance

The effects of dietary supplementation of Yucca schidigera and natural zeolite on broiler performance, ammonia concentration of broiler house, litter moisture, fecal dry matter and fecal crude ash were investigated. One day-old, nine hundred and sixty unsexed broiler chicks obtained from a commercial hatchery were divided into 4 treatment groups of 240 birds each. Birds were randomly assigned to the four treatment diets, consist of control, 15 g natural zeolite/kg, 25 g natural zeolite/kg and 120 mg Yucca schidigera /kg. Body weights of birds were significantly (P&lt;0.05) different among the treatments, birds fed on diet containing 120 mg Yucca schidigera /kg being the highest and this treatment was followed by chicks fed diet control at days 21 to 42 and 42nd day. Feed conversion ratio was not affected by the supplementation of Yucca schidigera and natural zeolite at days 21 to 42. From 21 to 42 and 42nd day of age, the feed intake was not significantly different between the treatments. Ammonia concentration of house was significantly (P&lt;0.05) decreased by adding Yucca schidigera and natural zeolite to diet. The supplementation of Yucca schidigera and natural zeolite to the diet reduced significantly (P&lt;0.01) fecal dry matter and crude ash. On the other hand, dry matter of the broiler litter and livability were not affected by treatments. It can be concluded that the supplementation of Yucca schidigera to the diet reduced ammonia concentration in broiler house, fecal dry matter and crude ash without any adverse effect of broiler performance. © Asian Network for Scientific Information, 2004