A comparison of thermal stress in the submarine escape using immersion half- and full suit in tropical weather operations.

OBJECTIVE: Submariners of disabled submarines are subject to drastic weather changes as they are awaiting rescue on the sea surface. Hyperthermia and hypothermia are just two of the adverse conditions that they can experience. The purpose of this study was to investigate the effectiveness of two models of submarine escape and the protective capabilities of immersion suits from environmental changes. METHOD: A randomized study involving 24 male subjects was conducted to compare the thermal capabilities of the full- versus half-configuration suit in a climate-controlled chamber. RESULTS: The full-configuration suits tested for a higher mean maximal core temperature (37.76 degrees C / 99.97 degrees F) than the mean maximal core temperature of the half-suits (37.52 degrees C / 99.54 degrees F). The full suits also tested for a higher mean minimal core temperature (36.13 degrees C / 97.03 degrees F) than the mean minimal core temperature (35.95 degrees C / 96.71 degrees F) of the half-suits. CONCLUSION: Results showed that the full-suit configuration did not induce clinically significant high levels of heat stress as compared to the half-suits, but instead provided better thermal protection against hypothermia than the half-suits.

Population phylogenomic analysis and origin of mitochondrial DNA in Chinese domestic pig.

The genetic diversity of eight domestic pigs was analyzed using a hypervariable fragment in the mitochondrial (mt) DNA control region; a portion of the hypervariable control region (515 bp) was sequenced from 153 samples. Haplotype diversity and nucleotide diversity in Yushan black pig populations were significantly higher than other populations (p < 0.01). A neighbor-joining tree was constructed from domestic pig mtDNA and five wild pigs. The results indicate that there are only small differences among individual pigs from different regions. Networks of the domestic pigs were constructed to better visualize the relationships between sequences. Each core haplotype was surrounded by a star-like pattern, consistent with recent population expansion.

An evaluation of fetal weight prediction using a simple equation containing the fetal femur length.

The accuracy of sonographic fetal weight estimation based on five published regression equations and two new equations generated from data at the authors' institution was evaluated on 41 small-for-gestational age (SGA) fetuses and 57 appropriate-for-gestational age (AGA) fetuses. Equations which contained the fetal femur length (FL) in addition to the biparietal diameter (BPD) and abdominal circumference (AC) yielded lower systematic and random errors in the SGA group but not in the AGA group. These findings support the contention that consideration of the FL is important in sonographic estimation of fetal weight in the growth-retarded fetus as head and limb growth may be affected to different degrees in different fetuses. A new equation, where birthweight in grams = 1.4 X (BPD(cm) X AC(cm) X FL(cm)) - 200, was developed which had a standard deviation of 98 g/kg in SGA fetuses and 68 g/kg in AGA fetuses. This equation yielded significantly lower random errors in the SGA but not in the AGA fetuses when compared with another linear equation without the FL. The new model is simple and practical to use, which makes it a viable alternative to more elaborate models containing three parameters.

Ankle brachial pressure index in systemic sclerosis: influence of disease subtype and anticentromere antibody.

OBJECTIVE: To test the hypothesis that patients with limited cutaneous systemic sclerosis (SSc) have a higher incidence of lower limb large vessel disease than patients with diffuse cutaneous disease, and that anticentromere antibody is a risk factor for lower limb large vessel disease. METHODS: Clinical and laboratory data from 119 patients with SSc (91 patients with limited cutaneous disease, 28 patients with diffuse cutaneous disease) who had bilateral ankle brachial pressure indices (ABPI) measured between March 1997 and January 2000 were reviewed retrospectively. RESULTS: There was no evidence of reduced ABPI in limited cutaneous disease (P=0.65), average reduction 0.01 [95% confidence interval (CI) -0.04 to +0.07]. There was some suggestion of reduced ABPI in anticentromere-positive patients (P=0.12), average reduction 0.04 (95% CI -0.01 to +0.09). CONCLUSIONS: The severity of large vessel macrovascular disease, as assessed by ABPI, is not dependent on disease subtype. Anticentromere antibody may be weakly associated with a reduction in ABPI.