Spin relaxation resonances due to the spin-axis interaction in dense rubidium and cesium vapor.

Resonances in the magnetic decoupling curves for the spin relaxation of dense alkali-metal vapors prove that much of the relaxation is due to the spin-axis interaction in triplet dimers. Initial estimates of the spin-axis coupling coefficients for the dimers (likely accurate to a factor of 2) are |lambda|/h = 290 MHz for Rb; 2500 MHz for Cs.

The Montefiore community children's project: a controlled study of cognitive and emotional problems of homeless mothers and children.

OBJECTIVES: This study compares the prevalence of emotional, academic, and cognitive impairment in children and mothers living in the community with those living in shelters for the homeless. METHOD: In New York City, 82 homeless mothers and their 102 children, aged 6 to 11, recruited from family shelters were compared to 115 nonhomeless mothers with 176 children recruited from classmates of the homeless children. Assessments included standardized tests and interviews. RESULTS: Mothers in shelters for the homeless showed higher rates of depression and anxiety than did nonhomeless mothers. Boys in homeless shelters showed higher rates of serious emotional and behavioral problems. Both boys and girls in homeless shelters showed more academic problems than did nonhomeless children. CONCLUSION: Study findings suggest a need among homeless children for special attention to academic problems that are not attributable to intellectual deficits in either children or their mothers. Although high rates of emotional and behavioral problems characterized poor children living in both settings, boys in shelters for the homeless may be particularly in need of professional attention.

MR imaging and spectroscopy using hyperpolarized 129Xe gas: preliminary human results.

Using a new method of xenon laser-polarization that permits the generation of liter quantities of hyperpolarized 129Xe gas, the first 129Xe imaging results from the human chest and the first 129Xe spectroscopy results from the human chest and head have been obtained. With polarization levels of approximately 2%, cross-sectional images of the lung gas-spaces with a voxel volume of 0.9 cm3 (signal-to-noise ratio (SNR), 28) were acquired and three dissolved-phase resonances in spectra from the chest were detected. In spectra from the head, one prominent dissolved-phase resonance, presumably from brain parenchyma, was detected. With anticipated improvements in the 129Xe polarization system, pulse sequences, RF coils, and breathing maneuvers, these results suggest the possibility for 129Xe gas-phase imaging of the lungs with a resolution approaching that of current conventional thoracic proton imaging. Moreover, the results suggest the feasibility of dissolved-phase imaging of both the chest and brain with a resolution similar to that obtained with the gas-phase images.

Cognitive and academic functioning of homeless children compared with housed children.

BACKGROUND: During the past 10 years, the number of homeless families has increased in every region of the United States. Despite several studies of this population, there are few data regarding the cognitive functioning of these homeless children. The aim of this controlled study was to determine the effect of homelessness on cognitive and academic functioning of children aged 6 to 11 years. METHODS: Homeless children (N = 102) and their mothers living in shelters were compared with a housed group of children (N = 178) and their mothers selected from the homeless child's classroom in New York City between August 1990 and August 1992. Groups were compared using standardized cognitive and academic performance instruments. RESULTS: Controlling for child's age, sex, race, social class, and family status, verbal intelligence (estimated by the Peabody Picture Vocabulary Test) and nonverbal intelligence (estimated by the Raven's Progressive Matrices) were not significantly different between the groups. However, academic achievement (measured by the Wide Range Achievement Test-Revised [WRAT-R]) was significantly poorer in reading, (75% of homeless children compared with 48% of housed children were below grade level), spelling (72.4% of the homeless children compared with 50% of housed children were below grade level) and arthmetic (53.6% of homeless children compared with 21.7% of housed children were below grade level). These dramatic differences in academic performance did not appear to be related to the mother's report of the number of days missed from school or the length of homelessness, but were associated with: (1) the number of school changes for the WRAT-R reading subtest and (2) grade repetition for the WRAT-R spelling subtest. CONCLUSIONS: These data demonstrae no difference in cognitive functioning between homeless and housed children. However, homeless children performed significantly more poorly than housed children in tests of academic performance.

Tap-scanning and extractive foraging in aye-ayes, Daubentonia madagascariensis.

The trees on which aye-ayes forage contain complex communities of organisms. Aye-ayes appear to use tap-scanning behaviour, in combination with complex perceptual and inferential capabilities, to exploit these communities as a source of food. In doing so, they alter them, perhaps to their own advantage.

Applications of cyberphysiologic techniques in pain management.

Hypnoanalgesia is a simple and effective method of pain control that is easily learned by children. It has been shown to be effective across a wide variety of clinical situations. In addition to decreasing discomfort, hypnoanalgesia diminishes anxiety, and increases mastery, cooperation, and hope. Particularly for children with chronic illnesses, this techniques can place some control over the illness in the hands of the child and engender greater competence and independence.

Induction of nest-material collecting in male Barbary doves by intracerebral androgen.

The behaviour of the male Barbary dove (Streptopelia risoria) in selecting nesting material and transporting it to the nest site is reduced after castration and is restored by treatment with testosterone propionate when castrated males received unilateral intracerebral implants of this androgen. Implants in the anterior hypothalamus, preopitc region, and the area of the ventral neostriatum intermediale were effective in reinstating the collection of nesting material, and in many instances restoration of the behaviour was to levels at or above those observed before castration. Implants in other areas, and implants without hormone, were generally without effect. Although the brain areas from which the gathering of nesting material can be elicited are comparable to those from which courtship displays have been induced in previous studies, it appears that testosterone propionate implants stimulate nesting activities more effectively and more persistently than courtship.

Courtship differences in male ring doves: avoidance of cuckoldry?

Male ring doves exhibit less courtship and more aggressive behavior toward females that have recently associated with other males than to females that have been isolated. The difference in response may be related to the differing probability of cuckoldry.