Educational status and health

Some of the problems with the traditional measures of socioeconomic status include (1) the loss of information resulting from combining different factors that have varying associations with health problems; (2) the reverse causal pathway that exists from health and illness to income and occupation; and (3) a number of particular problems with deriving socioeconomic status from census tract information. In contrast there are clear advantages to using educational status as the primary socioeconomic index. A wide variety of literature is reviewed pointing to a strong positive relationship between years of schooling and health. Three models that attempt to account for this association are described. It is suggested that the educational status of patients should be part of their data base.     

The interaction of ethanol and delta9-tetrahydrocannabinol in man: effects on perceptual, cognitive and motor functions

Twelve paid student volunteers (8 male, 4 female) were used in a double-blind crossover experiment to investigate the effects of delta9-tetrahydrocannabinol (THC) alone, and in combination with ethanol, on human perceptual, cognitive and motor functions. Both THC (10 mg/70 kg) and ethanol (0-5 g/kg) had little effect when administered alone. The combination of drugs, however, induced a significnat decrement in performance in some of the tests and this interaction was considered to be at least additive. The peak blood ethanol concentration was higher (P = 0-05) when subjects received both ethanol and THC than when they received ethanol alone.     

Salivary epithelial cells in primary culture: characterization of their growth and functional properties

Mouse submandibular salivary gland cells were grown in primary explant culture. After an initial period of degeneration within the explant, surviving epithelial cells proliferated rapidly and duct-like structures recolonized the explant. Autoradiographic studies showed that a peak of DNA synthesis occurred after 4 days in vitro and that proliferation was enhanced by insulin and hydrocortisone. These cells retained specialized secretory function (protease activity) for at least 2 weeks in vitro. This enzyme is a differentiated product of granular tubule cells in vivo. Between 6 and 10 days, explants attached to the substrate. An outgrowth developed, consisting largely of ultrastructurally identifiable epithelial cells which formed pseudoglandular structures in the monolayer. Epithelium survived for over 6 months in primary culture but could not be serially transferred. Secondary cultures were rapidly overgrown by mesenchymal cells.     

Effects of visual complexity and sex of infant in the conjugate reinforcement paradigm.

For each of 2 sex-balanced groups of 3.5-mo-old infants (N = 24), illumination of a black and white slide with either a 2 * 2 or a 24 * 24 checkerboard pattern was made directly proportional to the momentary rate of nonnutritive sucks greater than a predetermined criterion. A noncontingent baseline period of responding was followed by several minutes of conjugate sucking. Sucking performance was assessed by (a) the number of minutes to reach the decrement criterion (satiation time), (b) the rate of criterion sucking, and (c) the proportion of sucks which exceeded the amplitude criterion. Results indicate that check density did not differentially affect the sucking performance on any of the measures; sex of the S was significantly related to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hysterics and dysthymics as criterion groups in the measure of introversion-extraversion: A rejoinder to Eysenck's reply.

"Eysenck has accepted our results despite their alleged premature publication [see 33: 10806], but has disputed our interpretation of them. The most prematurely published result, using his criterion of sample size, showed psychopaths to be extraverted, as predicted by his theory. Presumably, he did not intend this to be a contentious point. A consideration of the other arguments advanced by Eysenck, some of which were supported by irrelevant data, enables us to reaffirm our original statement, namely, either hysterics and dysthymics cannot be used as criterion groups in the measure of introversion-extraversion, or the E scale is not a good measure of introversion-extraversion, or both statements are true." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of the Interparticle Pair Potential on the Rheological Behavior of Zirconia Powders: I, Electrostatic Double Layer Approach

Aqueous slurries containing 20 vol% ZrO₂ powder doped with 3 mol% Y₂O₃ were prepared by first dispersing the powder at pH 11, then adding 0.1 M to 1.0 M tetramethylammonium chloride (TMACl), or 1.0 M of TPACl, CsCl, and LiCl to produce different, weakly attractive particle networks. The particle pair potentials in the slurries were investigated by viscosity versus shear rate measurements. Slurries exhibited increasing viscosities (at a given shear rate) with increasing salt concentration and decreasing (unhydrated) counterion size. The viscosities for these weakly attractive networks were intermediate to dispersed (pH 11 without added salt) and flocced (isoelectric point, pH 7.5) slurries. Cylindrical bodies were consolidated from these slurries by pressure filtration at different applied pressures. The bodies consolidated from slurries formulated with TMACl had the highest packing densities relative to those consolidated from a flocculated slurry, but the relative densities were much lower than those achieved from bodies consolidated from a dispersed slurry. The plastic or brittle nature of these bodies was determined in uniaxial compression. Powder compacts consolidated from flocced slurries and slurries coagulated with 1 M TMACl, CsCl, and LiCl showed plastic behavior for filtration pressures ≤7.5 MPa. Results for ZrO₂ will be compared with those previously obtained for Al₂O₃, which produces plastic, consolidated bodies over a much broader range of slurry conditions.     

Reduced anesthetic requirements in aged rats: association with altered brain synaptic plasma membrane Ca(2+)-ATPase pump and phospholipid methyltransferase I activities

Aging is associated with a decrease in anesthetic requirements. Animal models of aging manifest alteration of brain Ca2+ homeostasis and increased methyltransferase I (PLMTI) activity. In this study we evaluated concurrently anesthetic requirements and brain plasma membrane Ca(2+)-ATPase (PMCA) and PLMTI activities in young and aged rats. Halothane, desflurane, isoflurane and xenon MEDs (lowest partial pressures that suppress a pain response) were measured in 2 and 25 month old, male Fisher-344 rats. Halothane MED was also measured in 2 and 30 month old F344/BNF1 rats, a strain that undergoes aging with less debilitation. PMCA pumping and PLMTI activities were measured in synaptic plasma membranes (SPM) prepared from the cortex and diencephalon-mesencephalon (DM). For aged Fisher-344 rats, MEDs for halothane, desflurane, isoflurane and xenon were reduced to 81%, 82%, 67% and 86%, respectively, of young controls; PMCA activity was diminished to 91% in cortical SPM and 82% in DM SPM; and cortical and DM PLMTI activities were increased to 131% and 114% of young control. For F344/BNF1 rats, MED for halothane was reduced to 87%, PMCA activity was diminished to 90% in cortical SPM and 72% DM SPM, and PLMTI activity was increased to 133% in cortical SPM and 112% in DM SPM. The strong association between age and reduced anesthetic requirements for inhalational agents on the one hand and altered PMCA and PLMTI activity on the other lends support to the underlying hypothesis that PMCA and PLMTI may be involved in the production of the anesthetic state.     

Methotrexate and misoprostol for early abortion

The Walkabout is a new hip-knee-ankle-foot orthotic (HKAFO) system with a medial single hip joint (MSH-KAFO) invented by S. McKay in 1992. Compared with other HKAFO systems, the hip joint part is compact and removable, so it has distinguishable, real merits: ease in donning and doffing the device, compatibility with a wheelchair, and cosmesis. We clinically tested five patients, paraplegic because of spinal cord injury, using the MSH-KAFO system. All were males, aged 26-36 yr old. Their functional levels were L-1 (2 cases), T-10 (2 cases), and T-5 (1 case). All patients could stand stably without crutches and walk in parallel bars immediately the first time they wore the braces. After a few hours of crutch-walking exercises, all could walk independently with Lofstrand crutches. Their walking velocities ranged from 10 to 37.5 (mean, 19.9) m/min at the follow-up points (mean, 7.1 mo). With four cases, we measured oxygen uptake for predictions of energy consumption. At comfortable walking, predicted energy consumptions were from 1.31 to 3.89 (mean, 2.75) METs. Compared with the data in literature, these seemed to be at the same level with normal walking and lower than the KAFOs walking level. Our results suggest that MSH-KAFO is a very convenient standing and walking device for paraplegics and is compatible with wheelchair use.     

On the Design of FIR Filters with Powers-of-Two Coefficients

FIR filters with powers-of-two coefficients are attractive for cost-effective implementations. The performance of one such structure, the difference routing digital filter [8], is discussed. Using an SNR criterion, an optimal algorithm to select the value of the filter coefficients is presented. Results indicate that a 2-3 dB improvement in the SNR can be obtained with this new approach. In addition, the study gives some insight into the relationship between the filter sampling rate, the number of coefficients, and the size of the coefficient alphabet. In particular, it is seen that a tradeoff between the filter sampling rate and the size of the coefficient alphabet exists.