Search PubMed⌕ Search

Biomedical subjects

N D White

Publications and source records attributed to N D White.

6 recordsLinked to original sources
PubMed1996

Effect of medicating ingredients and other additives on microflora present on swine and chicken feeds from a Manitoba mill.

The occurrence of microfloral components on medicated and non-medicated swine and chicken feed pellets and crumbles, produced in a Manitoba feed mill between June 1991 and October 1992, was determined. Addition of medicates to feeds generally decreased bacterial incidence and increased that of Eurotium spp. fungi. The effect was less pronounced when copper sulphate was added to medicated swine feeds.

Animal Feed↗
PubMed1995

A malathion resistance gene associated with increased life span of the rusty grain beetle, Cryptolestes ferrugineus (Coleoptera: Cucujidae).

The life span of the rusty grain beetle, Cryptolestes ferrugineus, was determined at 30 degrees C, 75% relative humidity (RH) for virgin and mated adults of a malathion-resistant strain (BC6RR), a malathion-susceptible strain (SS), the F1 progeny of a cross between resistant females and susceptible males (RS), and an outbred strain (GV). The BC6RR strain was derived from the SS strain by incorporating the malathion resistance gene into the susceptible genome with six backcrosses and recovery of heterozygous resistant F1 adults between crosses. The mean life span of virgin, malathion-resistant adults (BC6RR and RS) was 37 weeks; the mean life span of virgin, susceptible adults (SS and GV) was 32 weeks. Resistant virgin adults lived significantly longer (15-16%) than susceptible virgin adults, and mated resistant adults lived significantly longer (3-20%) than mated susceptible adults (p < .05). Since C. ferrugineus has a relatively long reproductive period and females with the longest life spans produce the most offspring, life span can be considered an important component of fitness in this insect. The malathion resistance gene did not reduce fitness, and this gene or genes closely linked to it may be responsible for increasing life span in C. ferrugineus.

Animals↗
PubMed1994

Fate of wheat bound malathion residues in rats during gestation.

Malathion [S-1,2-di(ethoxycarbonyl) ethyl 0,0-dimethyl phosphorodithioate], treated wheat when stored for 28 months at 20 degrees C with or without food grade white mineral oil on grains contained about 62 and 79% of the applied insecticide as bound residues, respectively. These bound residues were present mainly in the form of the parent compound. The stored wheat containing bound malathion residues, as well as wheat material freshly spiked with malathion were fed to rats during gestation. No residues of malathion and/or metabolites were detected in urine, feces and body tissues. Further no significant effect on body weight, serum chemistry and cytochrome P450 levels were observed in the mothers. There was no evidence for the histopathological alteration or teratogenic anomalies in the fetuses. However, placental transfer of malathion was indicated by the presence of the insecticide residues in fetuses from rats fed wheat material containing bound residues.

Animals↗
PubMedDate not supplied

Effects of mating status, sex ratio, and population density on longevity and offspring production of Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae).

The life span and reproductive rate of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were determined at different adult densities and sex ratios at 30 +/- 1 degree C, 75 +/- 5% relative humidity (RH), and with feed consisting of ground wheat plus wheat germ (4:1, w/w). The mean life spans of adult beetles were 32 weeks for adults individually isolated in separate vials, 22 to 25 weeks for adults of different strains kept one male and one female per vial, 24 weeks for a group of 30 virgin females together in one vial, 13 weeks for a group of 30 virgin males together in one vial, 14 weeks for groups with 10 males and 20 females per vial, 13 weeks for groups with 15 males and 15 females per vial, and 12 weeks for groups with 20 males and 10 females per vial. When kept one adult per vial, males and females had similar life spans; when kept one male and one female per vial, males lived longer; when kept in groups of 30 per vial females lived longer, except in the group which had a sex ratio of two males to one female; in this group life spans of males and females were the same. Females in separate vials with one male produced mean numbers of of offspring ranging from 389 for an inbred homozygous malathion-resistant strain to 514 for an outbred strain (genetically variable: GV). GV strain females in vials which had 10 males and 20 females produced a mean of 97 offspring, GV strain females in vials which had 15 males and 15 females produced a mean of 146 offspring, and GV strain females in vials which had 20 males and 10 females produced a mean of 216 offspring. The results of this study and similar studies on other insect species suggest that the life span of this insect is inversely related to the rate at which it expends energy and to injury incurred during copulation, and that oviposition rate decreases as the density of larvae and female adults increases.

Animals↗
PubMedDate not supplied

Understanding latex.

Explore the source record for details and available documents.

Gloves, Surgical↗