Thermally driven rossby-mode dynamo for solar magnetic-field reversals.

There is increasing interest in the possible existence of large eddies or "Rossby waves" in Sun's convection zone and photosphere. It is shown that many flows of this type, driven by an equator-pole temperature diffrence, act as hydromagnetic dynamos to produce magnetic fields that periodically reverse. The periods and field amplitudes agree with solar phenomena within an order of magnitude.

Anomalous solar rotation in the early 17th century.

The character of solar rotation has been examined for two periods in the early 17th century for which detailed sunspot drawings are available: A.D. 1625 through 1626 and 1642 through 1644. The first period occurred 20 years before the start of the Maunder sunspot minimum, 1645 through 1715; the second occurred just at its commencement. Solar rotation in the earlier period was much like that of today. In the later period, the equatorial velocity of the sun was faster by 3 to 5 percent and the differential rotation was enhanced by a factor of 3. The equatorial acceleration with declining solar activity is in the same sense as that found in recent Doppler data. It seems likely that the change in rotation of the solar surface between 1625 and 1645 was associated with the onset of the Maunder Minimum.

Laboratory experiments on planetary and stellar convection performed on spacelab 3.

Experiments on thermal convection in a rotating, differentially heated hemispherical shell with a radial buoyancy force were conducted in an orbiting microgravity laboratory. A variety of convective structures, or planforms, were observed, depending on the magnitude of the rotation and the nature of the imposed heating distribution. The results are compared with numerical simulations that can be conducted at the more modest heating rates, and suggest possible regimes of motion in rotating planets and stars.

Hypertrichosis cubiti.

Hypertrichosis is an unusual but well-recognized genetic condition. Hypertrichosis may be generalized or limited to specific body areas, in which case it is usually not associated with other anomalies. Five previous cases of hypertrichosis cubiti have been reported, with short stature in 2 sibs being the only other associated abnormalities. We report on a child with hairy elbows, developmental delay, facial asymmetry, and delayed speech with normal parents. Our patient may represent severe expression of the hairy elbow syndrome or constitute a previously unrecognized syndrome.

Familial osteosarcoma associated with 13;14 chromosomal rearrangement.

Two prepubertal sisters of American Indian origin developed osteosarcoma at 8 and 12 years of age. This familial occurrence, tumor onset prior to puberty, unusual tumor location in one who also had short stature, and ethnic background all suggest an inborn predisposition to bone cancer rather than a chance occurrence. Rearrangements involving chromosomes #13 and #14 were found in both the surviving proband and mother. Comparison of the arm ratio and prometaphase G-banding patterns of the rearranged chromosomes suggests either deletion of band 14q11.2 or pericentric inversion (with breakpoints at 13q12 and 14q11.2) in the proband's rearranged chromosome, but not in her mother's. Her mother, who had no malignancy, had a typical Robertsonian translocation [t(13;14)(p11;q11)]. Three previously reported children with chromosomal abnormalities developed osteosarcoma at unusually young ages, younger even than in reported sibships with osteosarcoma. The most frequently detected cytogenetic abnormalities in sarcoma tumor cells involve chromosomes #13 and #14. In addition, some cases of bilateral retinoblastoma and familial unilateral retinoblastoma, which are known to be at increased risk for osteosarcoma, are associated with tiny deletions on chromosome #13. Thus, there may be a causal relationship between constitutional loss or rearrangement of genetic material at these breakpoints on chromosomes #13 or #14 and development of osteosarcoma in this family that is similar to that seen in patients with small constitutional chromosomal deletions who develop Wilms' tumor and retinoblastoma.

Evaluation of a sexually transmitted disease/human immunodeficiency virus prevention train-the-trainer program.

In this study, a behavioral intervention known as the STD/HIV Intervention Program (SHIP) was implemented at the Navy preventive medicine technician (PMT) school as a "train-the-trainer" course. Course evaluation questionnaires were administered to PMT students immediately after the training. Follow-up interviews evaluating the SHIP course were conducted with PMTs (N = 73) 1 year after the training. PMT students were fairly satisfied with SHIP overall, as well as with specific components of the course. As hypothesized, the SHIP train-the-trainer course was considered useful by most PMTs in their first duty assignments after completing PMT school.

One-year follow-up evaluation of the sexually transmitted diseases/human immunodeficiency virus intervention program in a marine corps sample.

Although a substantial number of studies have been conducted to evaluate the impact of various human immunodeficiency virus (HIV) prevention programs, most of them have focused on civilian populations. There is a clear need to develop and evaluate sexually transmitted diseases (STD)/HIV prevention programs designed specifically for U.S. military populations. The objective of the present study was to determine whether a behavioral intervention known as the STD/HIV Intervention Program (SHIP) would have a sustained positive impact on the behavior of a sample of Marines. A 1-year follow-up telephone interview was administered to (1) Marines who participated in the SHIP course (intervention group), and (2) a quasi-control group of Marines who were not exposed to the SHIP course. The intervention and control groups differed significantly in the percentage of the time they had used condoms during the past year. The intervention participants reported using condoms a greater percentage of the time than the nonparticipants.

Attitudes toward euthanasia.

A 72-item questionnaire regarding attitudes toward euthanasia was administered to 240 residents of Humboldt County, California, who ranged from 18 to 86 years of age. The relationships between their attitudes and their demographic characteristics including age, religion, and education were examined.

Acute splenic sequestration in hemoglobin sickle O-Arab disease.

A white girl with sickle O-Arab disease (Hb S/O-Arab) had three separate episodes of acute splenic sequestration at 8, 12, and 15 months of age with hemoglobin levels falling to 3.9, 2.8, and 4.2 g/dl, respectively. Functional hyposplenism was suggested by the radionucleotide spleen scan. Following splenectomy her hemoglobin stabilized in the range of 0.7--8.5 g/dl. Life-threatening episodes of splenic sequestration, pneumococcal infections and osteomyelitis may occur in both Hb S/O-Arab and homozygous sickle cell diseases.

Leukemia risk among U.S. white male coal miners. A case-control study.

The relevance of occupational exposure to electrical and magnetic fields (EMF) in the etiology of leukemia has been raised in several studies. Underground coal miners represent an occupational group with situationally determined EMF exposure, as high-voltage power distribution lines are strung overhead in the mines and converters and step-down transformers provide power to mining equipment. Risk in occupational exposure to EMF was examined in a case-control study of 40 leukemia decedents and 160 control subjects who died of causes other than cancer or accident and who were matched on age at death. The control subjects were selected from a group of 6,066 persons whose deaths were reported in four National Institute for Occupational Safety and Health cohort mortality follow-up studies. Based on these data, 25 or more years of underground mining, a surrogate of EMF exposure, was found to pose a statistically significant risk for leukemia (International Classification of Diseases [ICD] codes 204 through 207, eighth revision), myelogenous leukemia (ICD 205), and chronic lymphocytic leukemia (CLL) (ICD 204.1). Accumulative exposure to chemical agents probably poses a risk for acute myelogenous leukemia, although this relationship fell short of being statistically significant. Although CLL has not previously been attributed to environmental agents, these data suggest a possible CLL risk from prolonged exposure to EMF.

Linkage analysis of neurofibromatosis (von Recklinghausen disease).

Linkage analysis of 28 genetic markers was undertaken in 108 subjects from 11 families with well-documented, classic, peripheral neurofibromatosis. Fifty-four persons were affected in one four-generation family, seven three-generation families, and three two-generation families. Lod scores were calculated using the standard LIPED programme for 49 combinations of theta male and theta female from 0.01 to 0.50. Lod scores excluded close linkage with 16 markers, including most tested on chromosome 1 and HLA on chromosome 6, and were inconclusive for 12 markers, including the secretor locus, closely linked to myotonic dystrophy. Analysis of five informative families resulted in a lod score of +2.2 for close linkage with GC on chromosome 4. However, the lod score for GC in the one additional informative family was negative, so that the final interpolated maximum was Z = 0.89 for theta male = 0.03, theta female = 0.28. Further studies are needed to evaluate this suggestion of linkage and possible genetic heterogeneity.

Hemodynamic and ECG responses to exercise in children with sickle cell anemia.

To determine whether exercise responses are different from normal in children with sickle cell anemia (SCA), we performed dynamic cycle ergometer exercise testing in 47 patients with SCA, aged 5 to 18 years, and 170 healthy, black age-matched control subjects. Seven (15%) of the patients with SCA had definitely ischemic, 16 (34%) had equivocally ischemic, and 24 (51%) had nonischemic ECG responses. Resting heart rate in the three groups of patients with SCA was higher than control values. Maximum exercise heart rate attained was lowest in the definitely ischemic group. All patients with SCA had decreased blood pressure responses and maximum working capacity when compared with control subjects. Hemoglobin concentration was lowest in the definitely ischemic group and correlated with maximum workload. Long-term myocardial ischemia may lead to fibrosis and the decreased myocardial contractility seen in adult patients with SCA.