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At least 19 recordsLinked to original sources

Minimum protection factors for respiratory protective devices for firefighters.

Carbon monoxide and oxygen concentrations were measured in seventy-two structural fires using a personal air sampler carried by working firefighters. In a total sampling time of 1329 minutes the carbon monoxide concentration exceeded 500 ppm approximately 29 percent of the time. The maximum carbon monoxide concentration was 27,000 ppm and in 10 percent of the fires, the maximum concentration exceeded 5500 ppm. Only six runs indicated oxygen concentrations less than 18 percent. On the basis of these exposure data, a minimum protection factor of 100 is proposed for breathing apparatus for structural firefighting.

Air

The mediating role of protective factors in relationship between caregiving components and psychosocial adjustment among young carers: a meta-analysis.

OBJECTIVE: Higher youth caregiving is associated with poorer psychosocial outcomes in young carers; hence a research priority is to investigate protective factors that mitigate the adverse effects of youth caregiving. This systematic review with meta-analysis examined the relationships among youth caregiving components and young carer psychosocial adjustment and protective factors, as well as the mediating role of the protective factors in the relationship between caregiving components and psychosocial adjustment. METHODS: Three electronic databases were searched until April 2024 and 10,244 unique publications were identified. Following abstract and title screening, 422 publications were subjected to full-text screening and 60 quantitative studies were included in this study. RESULTS: Meta-analytic structural equation modeling (MASEM) results revealed positive direct effects of caregiving responsibilities and caregiving experiences on benefit finding (&#x3b2;&#xa0;=&#xa0;.43, 95% CI [.074, .782], p&#xa0;<&#xa0;.05) and emotion regulation (&#x3b2;&#xa0;=&#xa0;.72, 95% CI [.44, 1.00], p&#xa0;<&#xa0;.001), respectively. However, there was neither a significant direct effect of caregiving components on psychosocial adjustment nor a significant indirect effect of caregiving components on psychosocial adjustment through benefit finding or emotion regulation. CONCLUSION: Findings revealed a need for research into how caregiving contextual factors affect relations among youth caregiving, protective factors, and adjustment.

Humans

Modulation of cross-protection factor(s) of avian Pasteurella multocida.

Cross-protection factor(s) (CPF) of Pasteurella multocida were maintained in vitro through at least 9 serial passages. Different growth media and temperatures enhanced or repressed the ability of P. multocida to produce CPF. Certain amino acids were innoculous to expression of CPF. B-vitamins enhanced CPF, whereas certain inorganic salts repressed CPF. The plasma of normal tuekeys contained a compound or compounds that were responsible for expression and maintenance of CPF.

Animals

The variability of the protection factors for sunscreening products.

The variation of the preotection factors for a sunscreening product as determined for different test subjects can be described by a logarithmic normal distribution. It is therefore more appropriate to use logarithmically transformed data for statistical analyses. By means of an analysis of variance it was shown that the influence of the subjects is responsible for only 12% of the total variance, whereas the remaining 88% is due to experimental error. Therefore, the difficulties in determining precise protection factors must be ascribed to deficiencies in the method itself. It was further concluded that correcting the protection factors with respect to a simultaneously measured reference preparation is not a means of improving the precision of the data. The reference substance, if it is included in every measuring series may, however, be used to check the long-term constancy of the method and to compare results from different laboratories.

Analysis of Variance

Definition of dietary fiber and hypotheses that it is a protective factor in certain diseases.

Crude fiber (CF) is the residue of plant food left after extraction by dilute acid followed by dilute alkali. Dietary fiber (DF), a new term, is the residue of plant food resistant to hydrolysis by human alimentary enzymes. DF is composed of cellulose, hemicellulose, and lignin; these constituents are not reported in food tables. For instance, whole wheatmeal has DF about 11%, CF about 2%. It is suggested that a new term, dietary fiber complex (DFC), should include all substances of DF plus all chemical compounds naturally associated with, and concentrated around, these structural polymers. CF supplies from starchy staples, wheat and potato, in England and Wales were probably stationary from 1770 to 1860, fell greatly from 1860 to 1910, rose during food controls in 1942 to 1953, and declined slightly from 1954 to 1970. It is postulated that fiber is a protective factor against certain colonic disorders, such as diverticular disease, and certain metabolic diseases, such as ischemic heart disease, diabetes mellitus, and obesity. These three diseases had changing trends of mortality rates in England during the food control years. Westernization of African diets is accompanied by a large fall in CF from starchy foods and vegetables and an increased prevalence of the same three diseases.

Adult

Breast cancer: potentially predisposing and protecting factors. Role of pregnancy, lactation, and endocrine status.

Risk factors of breast cancer have been correlated with the availability of estradiol and estrone. Mechanisms protecting from breast cancer are thought to be due to the mitotic rest of mammary epithelium (low deoxyribonucleic acid synthesis), as encountered during pregnancy and lactation, and to the actions of estriol and progesterone in opposing the "carcinogenic" estradiol and estrone.

Adult

Previous pregnancy as a protective factor against death from melanoma.

Examination of the case-records of women presenting to the Melanoma Unit at Sydney Hospital over the period 1961-71 has shown that women with pregnancies before the development of melanoma had a better survival-rate from melanoma than women without previous pregnancies. The known presence of fetal antigens on melanoma cells and immunisation against fetal antigens during pregnancy suggest an immunological explanation for these results. Exposure to fetal antigens during pregnancy may protect against the dissemination of melanoma cells bearing similar fetal antigens and thus increase the survival-rate. The incidence of melanoma in males and females was approximately equal, which suggests that immune responses to tumour-associated antigens may be more effective in preventing spread of tumours than in preventing their occurrence.

Adult

The cryopreservation of Chlorella. 4. Accumulation of lipid as a protective factor.

Following growth under sub-optimal concentrations of nutrients, cells of Chlorella emersonii accumulated lipid and became more resistant to the damage caused by freezing and thawing. These results suggest that the factor responsible for the cold hardening of some Chlorella spp is not the effect of low temperatures per se but simply that of the reduced metabolic rate. Evidence is given that the post-thaw injury observed following rapid rates of cooling is associated with the vacuole.

Chlorella

High density lipoprotein as a protective factor against coronary heart disease. The Framingham Study.

Lipid and lipoprotein values, including fasting triglycerides and high density lipoproteins (HDL), low density lipoproteins (LDL) and total cholesterol levels, were obtained on 2,815 men and women aged 49 to 82 years chiefly between 1969 and 1971 at Framingham. In the approximately four years following the characterization of lipids, coronary heart disease developed in 79 of the 1,025 men and 63 of the 1,445 women free of coronary heart diseases. At these older ages the major potent lipid risk factor was HDL cholesterol, which had an inverse association with the incidence of coronary heart disease (p less than 0.001) in either men or women. This lipid was associated with each major manifestation of coronary heart disease. These associations were equally significant even when other lipids and other standard risk factors for coronary heart disease were taken into consideration. A weaker association with the incidence of coronary heart disease (p less than 0.05) was observed for LDL cholesterol. Triglycerides were associated with the incidence of coronary heart disease only in women and then only when the level of other lipids was not taken into account. At these ages total cholesterol was not associated with the risk of coronary heart disease.

Age Factors