Chronic selenosis in horses fed locally produced alfalfa hay.

Chronic selenosis (alkali disease) was diagnosed in horses of western Iowa, a region associated with marginal to adequate soil selenium. Two locally produced alfalfa hays (Medicago sativa L) were identified as the primary source. Difficulty in selecting diagnostic specimens to evaluate potential chronic selenosis cases is complicated by the wide range of tissue concentrations reported in previous cases, conflicting correlation of sample selenium concentrations in the literature, and different recommendations on specimen selection and diagnostic value. These problems arise form the similarity in clinical signs for mild and severe chronic selenosis cases, and inability to establish the disease time course. Therefore, collection of multiple samples to confirm high selenium concentration in various tissues and identify selenium sources is recommended. Value of samples believed to reflect historical exposure vs current status may be questionable. Interpretation of results by practitioners and diagnosticians should consider selenium exposure level and duration, antagonistic or ameliorating factors, and postexposure excretion.

Life-threatening hemorrhage due to uterine vascular abnormality.

A case is reported of a 25-year-old woman stricken with prolonged and life-threatening menorrhagia from abnormal uterine vessels resembling hemangioma cavernosum. The condition was suspected at ultrasonic investigation. Hysterectomy was performed as an emergency operation.

Radionuclides in mono lake, california.

Several radioisotopes of the naturally occurring uranium and thorium decay series, in addition to fallout plutonium, have unusually high concentrations in the water column of Mono Lake, a natural alkaline, saline lake. Complexing by carbonate ions appears to be responsible for the enhanced solubility of actinide elements with oxidation states of IV to VI. In contrast, fallout strontium-90 has been largely removed from the water, probably as a result of coprecipitation with calcium carbonate. The daughter/parent activity ratios of thorium, radium, and uranium isotopes suggest that thorium is removed from the water column to the sediments on time scales substantially longer than a month and that the desorption of thorium from the sediments to the water column requires less than a few years.

[The birth rate in 1982. Assessment of the prediction of birth rate in 1981 and a prognosis for 1982 on the basis of registered pregnancies in the county of Fredriksborg]. / Fødselstallet i 1982. Vurdering af prognosen for fødselstallet i 1981 samt prognose for 1982 på grundlag af registrerede graviditeter i Frederiksborg amtskommune.

PIP: Predictions of the birth rate in Denmark for 1981 based on a centralized register of pregnant women in Frederiksborg county are reviewed, and their accuracy is confirmed. Similar predictions for 1982 using the same source of data are presented with suggestions of a smaller decline in fertility than that which occurred in 1981. (summary in ENG)^ieng

[Birth rate in 1981. A prognosis based on registered pregnancies in the county of Fredriksborg]. / Fødselstallet i 1981. En prognose på grundlag af registrerede graviditeter i Frederiksborg amtskommune.

PIP: On the basis of a centralized registration of pregnant women early in pregnancy, it is possible with adequate certainty to predict the birth rate 1/2-1 year in advance. On this basis, it has been calculated that the birth rate in the county of Frederiksborg, Denmark (population as of January 1, 1980--329,141 persons) will fall by 16% during the first 1/2 of 1981 as compared with the first 1/2 of 1980. As far as alterations in the birth rate for the county are concerned, they follow, by and large, the alterations seen in Denmark as a whole; thus a fall in birth rate is to be anticipated in the country as a whole. (author's)^ieng

Fallout plutonium in an alkaline, saline lake.

Plutonium isotopes, derived from global fallout following atmospheric testing of nuclear weapons, have been measured in the water and sediments of a natural alkaline, saline lake. The activities of fallout plutonium in the water column are about two orders of magnitude greater than in most freshwater lakes, where these nuclides are found predominantly in the sediments.

Man-made radionuclides and sedimentation in the Hudson River estuary.

Recently deposited fine-grained sediments in the Hudson River estuary contain radionuclides from global fallout produced by atmospheric bomb tests as well as from low-level releases of a local nuclear reactor. Accumulation rates of these nuclides are dependent on rates of sediment deposition and vary with location in the estuary by more than two orders of magnitude. Within the Hudson estuary, New York harbor is currently the zone of most rapid deposition of sediments containing radionuclides, some of which were released from a nuclear reactor about 60 kilometers upstream of the harbor.

Correction for mechanical dead space in the calculation of physiological dead space.

When physiological dead space (Vd(p)) is calculated for a patient who has alveolar dead space, e.g., after pulmonary vascular occlusion, less than the full volume of attached mechanical dead space (Vd(m)) appears in the measured dead space (Vd(n)). Under these conditions the traditional subtraction of Vd(m) from Vd(n) leads to underestimation of Vd(p) and can give a falsely small ratio of Vd(p) to tidal volume (Vt) when, in fact, an abnormally large Vd(p)/Vt exists. To make the proper correction for Vd(m), two equations have been derived and validated with seven subjects having Vd(p)/Vt from 0.29 to 0.87, using Vd(m)'s from 120 to 322 ml. With only a small modification, these equations are suitable for routine clinical use and give Vd(p)/Vt within 0.02 of that by the validated equations (32 of 33 comparisons). The fraction of Vd(m) subtracted from Vd(n) is the square of the ratio of effective alveolar to total alveolar ventilation and is never > 1. This fraction is (Pa(CO2)/Pa(CO2))(2), where Pa(CO2) and Pa(CO2) are the mean partial pressures of expired alveolar and of arterial CO(2); in the other equation this fraction is [Pe(CO2)/Pa(CO2) (Vt - Vd(an) - Vd(m))](2) where Pe(CO2) is mixed expired Pco(2) and Vd(an) is anatomical dead space. The second equation requires an estimated Vd(an) and is applicable when Pa(CO2) is not measured or does not plateau (as in exercise).

"Blow" of the pilot whale.

A captive pilot whale emptied as much as 88 percent of lung gas passively, without the aid of expiratory muscles. Level or decreasing pressures in the esophagus during expiration, and in the blowhole at the onset of expiration, revealed the driving force of expiration to be solely elastic recoil. Active muscular reexpansion of the lungs ensued immediately. Expiration and inspiration were completed in about I second.