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Biomedical subjects

B P Weiss

Publications and source records attributed to B P Weiss.

7 recordsLinked to original sources
PubMed2000

A low temperature transfer of ALH84001 from Mars to Earth.

The ejection of material from Mars is thought to be caused by large impacts that would heat much of the ejecta to high temperatures. Images of the magnetic field of martian meteorite ALH84001 reveal a spatially heterogeneous pattern of magnetization associated with fractures and rock fragments. Heating the meteorite to 40 degrees C reduces the intensity of some magnetic features, indicating that the interior of the rock has not been above this temperature since before its ejection from the surface of Mars. Because this temperature cannot sterilize most bacteria or eukarya, these data support the hypothesis that meteorites could transfer life between planets in the solar system.

Crystallization↗
PubMed2000

Atmospheric energy for subsurface life on Mars?

The location and density of biologically useful energy sources on Mars will limit the biomass, spatial distribution, and organism size of any biota. Subsurface Martian organisms could be supplied with a large energy flux from the oxidation of photochemically produced atmospheric H(2) and CO diffusing into the regolith. However, surface abundance measurements of these gases demonstrate that no more than a few percent of this available flux is actually being consumed, suggesting that biological activity driven by atmospheric H(2) and CO is limited in the top few hundred meters of the subsurface. This is significant because the available but unused energy is extremely large: for organisms at 30-m depth, it is 2,000 times previous estimates of hydrothermal and chemical weathering energy and far exceeds the energy derivable from other atmospheric gases. This also implies that the apparent scarcity of life on Mars is not attributable to lack of energy. Instead, the availability of liquid water may be a more important factor limiting biological activity because the photochemical energy flux can only penetrate to 100- to 1,000-m depth, where most H(2)O is probably frozen. Because both atmospheric and Viking lander soil data provide little evidence for biological activity, the detection of short-lived trace gases will probably be a better indicator of any extant Martian life.

Atmosphere↗
PubMed1988

Public health at the 1984 Summer Olympics: the Los Angeles County experience.

During the 1984 Summer Olympic Games, the Los Angeles County Department of Health Services used its active disease surveillance system to monitor disease occurrence and other health concerns. Reports were collected by telephone three times a week from 198 participating facilities including hospitals, prepaid health plans, private physicians, and Olympic sites. Background data were obtained two months preceding the Olympic events. Less illness was recorded during the Olympics than during the same period for the three preceding years.

California↗
PubMed1985

Clinical effectiveness of rubella vaccine in a college population.

An outbreak of rash-like illness compatible with rubella occurred among the student population of a large university in Los Angeles between November 1, 1981 and January 31, 1982. A case-control study was conducted in order to estimate the effectiveness of rubella vaccine in preventing clinical rubella in this university population. Immunization and disease histories were obtained from parents and physicians for 39 cases and 86 controls. For those students with a clear documentation of immunization history, only one of 16 cases (6%) had evidence of prior rubella immunization, compared with 40 of 56 controls (71%). This yielded an estimated vaccine effectiveness of 97% (95% confidence limits of 82% to 100%). The level of protection observed for students immunized with rubella vaccine in our study population was high and comparable to that reported in other recent studies. This supports the notion that the current large reservoir of young adult susceptibles is primarily attributable to past failures to vaccinate school-age children, rather than vaccine failures.

Adult↗
PubMed1983

Tetanus and diphtheria immunity in an elderly population in Los Angeles County.

Fifty-four per cent of 246 subjects attending senior citizen centers (mean age 69), and 29 per cent of 111 convalescent hospital subjects (mean age 82) had protective levels of tetanus antitoxin (greater than or equal to 0.01 units/ml). Age-specific immunity levels were lower for females than males, and generally decreased with age. Forty-eight and one-half per cent of the senior citizen center subjects and 55.9 per cent of the convalescent hospital subjects had protective levels of diphtheria antitoxin (greater than or equal to 0.01 units/ml).

Age Factors↗
PubMedDate not supplied

Improving disease reporting in Los Angeles County: trial and results.

A telephone survey of physicians in Los Angeles County revealed that 50 percent of 405 contacted were unaware of the legal mechanism for reporting communicable diseases--the Confidential Morbidity Report (CMR) card. After that survey, three measures were taken in an effort to improve reporting and surveillance: (a) use of a stamped self-addressed CMR postcard, (b) publication of the monthly newsletter "Public Health Letter," which was distributed to 23,000 health professionals in Los Angeles County free of charge, and (c) initiation of an active disease surveillance system that included 171 reporting sites contacted weekly (76 physicians, 36 schools, 33 preschools, 22 hospitals, and 4 university student health centers). No increase in the levels of disease reporting was observed, based on 4 years' experience with the revised CMR card and the Public Health Letter. The active disease surveillance system, however, has provided anecdotal reports of disease occurrence and notification of outbreaks of both reportable and nonreportable diseases. Moreover, the authors believe it has improved rapport between the county health department and the medical community.

Attitude of Health Personnel↗