Cognitive processes in normal and hyperactive children and their response to amphetamine treatment.

14 normal (mean age 10.1 yrs) and 15 hyperactive (mean age 9.4 yrs) children were compared on cognitive tasks following placebo or amphetamine administration (.5 mg/kg) in a double-blind crossover study. A no-treatment control group of normal children who were matched with the hyperactive Ss on age, IQ, and socioeconomic status were also tested on the cognitive measures. In the undrugged state, normals remembered more information under free-recall retrieval conditions than did hyperactives; cued recall did not differentiate between the 2 groups. Both normals and hyperactives demonstrated similar, amphetamine-related increases in the recall of semantically and acoustically processed words. This enhancement of cognition occurred along with improvements in attention but was independent of such attentional changes. The pattern of amphetamine-induced changes in cognition is generally similar in normal and hyperactive children. Differences in response to amphetamine that do appear involve components of cognition that distinguish these children in the undrugged state (e.g., semantic processing, organization in recall, and free retrieval of information). (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The evolution of the Hox cluster: insights from outgroups

When a tumor or other heterogeneous cell population is acutely exposed to ionizing radiation (or, for that matter, to chemotherapeutic agents or hyperthermia), cells that happen to be more sensitive will be preferentially removed, leaving behind a population more resistant as a whole. However, under broadly applicable assumptions, we here demonstrate mathematically that there is a natural tendency of the postirradiation population to recover from the irradiation in such a manner as to restore its original sensitivity composition, i.e. to undergo "resensitization". An important consequence in radiotherapy is that, if a fixed total radiation dose is delivered in a more protracted manner, e.g. as several fractions or as a continuous dose at low dose rate, resensitization occurring over the course of dose delivery will result in greater cell killing than would otherwise have occurred. That is, for a cell population with any form of diversity in radiosensitivity, the influence of redistribution is to make any prolonged dose more damaging than an acute dose of the same magnitude. This tendency toward an "inverse dose-rate effect" may be masked in practice by countervailing effects, such as repair of sublethal damage, but the tendency is demonstrated to hold under very general circumstances, being a consequence of cell-cell diversity and the dynamic response of the cell population to treatment.     

The geographic and sociodemographic transformation of multifamily rental housing in the Texas Triangle

This study catalogues the location, clustering and sociodemographic distribution of the development of multifamily rental housing over the last five decades in the Texas Triangle, one of the fastest growing megaregions in the United States. The research reveals prior to the 1970s, apartments clustered in downtown areas; throughout the 1980s and 1990s, the development of apartments expanded to the suburbs and along major interstates; and in the 2000s, apartment growth continued in the peripheral areas while returning downtown. During this time period, apartments were developed most often in majority white, high-income and low-poverty neighbourhoods. These geographic and sociodemographic characteristics challenge widespread conceptions that equate multifamily rental housing with central city locations and low-income populations. The findings suggest that multifamily rental housing offers a powerful tool to increase residential density in downtown and suburban locations, while also accommodating a sociodemographically diverse population.     

Exploring the neural organization of person-related knowledge: Lateralization of lesion, category specificity, and stimulus modality effects.

While it is generally agreed that the right fusiform gyrus is specialized for face recognition, the question of whether knowledge about persons is lateralized in the temporal lobes is more contentious. Does knowledge about people differ from other kinds of object knowledge with respect to brain laterality? Are side-of-lesion effects mediated by stimulus modality? This study aimed to investigate these questions by comparing patients with left temporal (LT) (n = 8) and right temporal (RT) (n = 11) lesions to control subjects (n = 12) on verbal and visual tests of people, buildings, and objects. The RT group was impaired at recognizing famous faces, but not at choosing the picture of a famous building or a famous name from nonfamous distracters. The LT group was impaired at naming people, buildings, and objects, regardless of stimulus modality. When presemantic processing was controlled for, neither patient group was impaired in producing person-specific knowledge to faces or names, supporting the notion that semantic knowledge for people as for other kinds of objects, is stored in a distributed network across both hemispheres, regardless of stimulus modality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aspiration pneumonia secondary to giant cervical osteophyte formation (diffuse idiopathic skeletal hyperostosis or Forrestier''s disease): a case report

The technique of computer-aided transcranial Doppler echography for continuous control of cerebral perfusion during minimally invasive mitral valve operations using the Port-Access system is described. Temporary displacement of the endoclamp in the aortic arch (brachiocephalic trunk, left carotid artery) is followed by cerebral embolic signals and a sudden decrease in the blood flow velocity in the middle cerebral arteries.     

Behavioral effects of psychomotor stimulants in rats with dorsal or ventral subiculum lesions: Locomotion, cocaine self-administration, and prepulse inhibition of startle.

Compelling evidence suggests a primary role for the mesoaccumbens dopaminergic pathway in the behavioral effects of amphetamine and cocaine, but the roles of other projections to the accumbens, including those arising in the hippocampal formation, are less clear. The authors evaluated the effects of discrete excitotoxic lesions of either the dorsal or ventral subiculum on the locomotor activating, reinforcing, and sensorimotor gating-disruptive effects of psychomotor stimulant drugs. Whereas dorsal subiculum-lesioned rats were hyperactive in tests of exploratory locomotion and startle reactivity, ventral subiculum-lesioned rats exhibited an attenuated locomotor response to amphetamine, moderately impaired acquisition of cocaine self-administration, and reduced levels of prepulse inhibition of startle. These 2 behavioral profiles overlap considerably with those previously observed in rats with lesions of the rostrodorsal and caudomedial accumbens, respectively, and suggest that projections from dorsal subiculum to accumbens core and ventral subiculum to accumbens shell exert distinct influences on behavioral responses that are amplified by psychomotor stimulant drugs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a dietary mixture of meat and bone meal, feather meal, blood meal, and fish meal on nitrogen utilization in finishing Holstein steers

Our objective was to determine to what extent rate and efficiency of protein gain in finishing cattle can be enhanced by feeding an amino acid-balanced mixture of undegraded intake proteins. The Cornell Net Carbohydrate and Protein System (CNCPS) model was used to formulate a corn-based diet that would meet the rumen requirements for 410-kg large-framed steers with an estrogen implant and fed an ionophore. The CNCPS model was also used to formulate a highly undegradable intake protein (UIP) mixture from meat and bone meal, blood meal, fish meal, and hydrolyzed feather meal to provide the amino acids needed to supplement those derived from microbial protein to better meet amino acid requirements for growth. Four Holstein steers weighing 407 kg were offered a 90:10 concentrate-forage diet at hourly intervals at 95% of ad libitum intake. The steers were injected with 500 microg of estradiol-17beta at 12-h intervals to mimic the effects of an estrogenic implant. Treatments planned consisted of inclusion of the UIP mixture at 0, 2.5, 5, and 7.5% of the diet DM. Dry matter intake was fixed at 6.4 kg/d, and DM digestibility was not significantly affected by varying the amount of UIP addition. Apparent digestibility of N increased (P = .011) from 63.8 to 65.8, 70.7, and 71.5%, the amount of N absorbed increased (P = .001) from 73 to 84, 100, and 106 g/d, and N balance increased (P = .003) from 20 to 30, 33, and 39 g/d when UIP was fed at 0, 2.6, 5.2, and 7.8% of diet DM, respectively. The efficiency of N use increased 39.7%, and biological value increased 31.6% when the UIP mixture was added to the diet. Circulating concentrations of plasma urea N (PUN) were increased (P = .017) from 4.5 for the control diet to 5.7, 6.2, and 6.1 mg/dL when the UIP mixture was added at 2.6, 5.2, and 7.8%, respectively. Corresponding IGF-I concentrations were also increased from 491 to 558 and 624 ng/mL with 2.6 and 5.2% levels of UIP addition. Plasma glucose, NEFA, and insulin concentrations were not affected by feeding the UIP mix. The rate and efficiency of N use for growth improved with addition of an amino acid-balanced UIP mixture to the diet.