Microvessel density of invasive breast cancer assessed by dynamic Gd-DTPA enhanced MRI

We compared Wada memory performance for stimuli presented at two timing intervals following amobarbital injection in 47 non-lesional patients with complex partial seizures (L = 26; R = 21). A significant interaction between seizure focus and timing of presentation was present (P < 0.03). Memory performance for objects whose presentation began approximately 50-55 s following amobarbital administration differed as a function of ipsilateral vs. contralateral injection at a very high level of statistical significance (P < 0.00001). Items presented approximately 4 min, 30 s post injection were also related to seizure onset literality, but at a lower statistical level (P < 0.01). Presentation of Wada memory stimuli earlier during hemispheric anaesthesia yields results that are more sensitive to lateralized temporal lobe seizure onset than does presentation of items later during the procedure.     

Wettability of TiC by commercial aluminum alloys

The effect of alloying elements on the wettability of TiC by commercial aluminum alloys (1010, 2024, 6061 and 7075) was investigated at 900°C using a sessile drop technique. Wetting increased in the order 6061 < 7075 < 2024 < 1010 for both, static argon or vacuum atmospheres. Alloys 1010 and 2024 wet TiC under both atmospheres, leading to contact angles in the order of 60° and less, while 7075 only wets under vacuum, with the poorest wettability being exhibited by 6061. Evaporation of Zn and Mg under vacuum conditions contributed to the rupture of the oxide film covering the aluminum drop and thereby improving wetting and spreading. Continuous and isolate Al₄C₃ was detected in all the cases. CuAl₂ precipitation at the interface slightly decreased Al₄C₃ formation and increased the adhesion of 2024 to TiC.     

Solar heating system performance estimation using sinusoidal inputs

A method is presented for the estimation of the fraction of the heating load supplied by solar energy during the heating season. This procedure remains useful even when system design parameters are far from the norm, and in particular is applicable to systems incorporating seasonal storage of heat. Insolation, temperature and hot water demand are input as sinusoids, and the closed-form solution of the heat transfer differential equation is found. The method as presented here is suitable for domestic hot water and liquid space heating systems.     

Human resources development for communications in the Third World

This article summarizes Third World prospects for the development of human resources in communication programs. The discussion examines the structural causes of high demand for development of human resources. Also studied are pressures that stem from the dense populations in the regions, the cultural and linguistic diversity faced by their peoples, and the global media explosion. The shortage of suitable staff for communication programs has become chronic in most non-industrialized regions, making human resource development a high priority for media and other information services.     

Magnetization and Curie Temperature of Ilmenite–Hematite Ceramics

The morphology, structure, and magnetic properties of the magnetic semiconductor ceramic Ilmenite–Hematite (IH), (1− x )FeTiO₃– x Fe₂O₃, were studied as a function of the composition x . The magnetic ordering temperatures that we observed were consistently higher than those reported previously and were, for most of the composition range, above room temperature. We rule out the formation of Fe clusters as the origin of the magnetic properties. These magnetic properties of IH ceramics, in combination with their semiconducting characteristics, render them promising for spin-electronic applications.     

Hyperactive and hypoxic children: Signal detection, sustained attention, and behavior.

Two parameters from signal detection theory—perceptual sensitivity and decision criterion cutoff scores—were used in the analysis of vigilance performance of 30 hyperactive (mean age 8.5 yrs), 30 hypoxic (mean age 9 yrs), and 47 normal (mean age 8.8 yrs) children. Signal detection analyses of 3 Continuous Performance Test conditions indicated that with increasing age, Ss obtained significantly more hits, fewer false alarms, higher perceptual sensitivity, and responded with greater caution. Overall deficits in signal discrimination (perceptual sensitivity level) were obtained for both the hyperactive and hypoxic Ss when compared to normal age-mates. Whereas the hypoxic Ss demonstrated additional decrements in sustaining attention (sensitivity decrement over time), the hyperactive Ss were impaired by low-response caution, reflecting difficulty inhibiting impulsive responses. Possible differences in hyperactive sample characteristics across studies and time-related recovery factors following hypoxia are discussed. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)