Cortical control of claw cutting in the rat.

Claw cutting emerges as a behavior between Postnatal Days 30 and 50 for normal rats, and by Day 100 at least 80% have cut their claws. In the present study with 275 Long-Evans rats, complete frontal ablation or total decortication at any age abolished claw cutting but complete posterior neocortex removal did not. In adult Ss, motor cortex ablations or hemidecortications abolished claw cutting, whereas the same lesions given to infant Ss spared claw cutting. Neonatal telencephalic noradrenaline depletion had no effect on the development or incident of claw cutting. Loss of claw cutting appeared to be due to loss of efficient biting and chewing rather than to an inability to orient or to groom. The sparing after infant ablations may have been due to functional reorganization of tissue within, or adjacent to, the developing motor cortex. Findings indicate that careful examination of features of the laboratory rat's appearance can provide useful clues about its behavioral competencies. Abnormalities such as loss of claw cutting can serve as a useful diagnostic indication of specific kinds of brain damage. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A proposed technique for the treatment of restriction of range of selected validation.

Evaluates traditional correction formulas designed to adjust for the effects of restriction of range in validation studies and proposes a new technique that resolves an important limitation of these earlier approaches. The conventional formulas require that the restricted variable be completely measured, even though most selection contexts involve restriction of range on both measured and unmeasured variables. The authors propose the use of a recently developed econometric technique that can correct for restriction of range attributable to both measured and unmeasured variables. The procedure explicitly recognizes the 2nd equation implicit in any validation study: the sample selection process. Based on well-established distribution theory and the assumption that the error terms in the 2 equations are distributed bivariate normal, the technique enables the researcher to estimate the bias associated with using the restricted sample. The limitations of the procedure and its applicability to a variety of selection problems are also discussed. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Authors'' Reply2

The authors' digital counting of minima is the equivalent of the classical method of frequency measurement by zero crossing of the signal after differentiation by an RC network.     

Turbulent mixing in free swirling jets

Marker nephelometry was used to study the nozzle fluid concentration field of free swirling turbulent jets. Swirl was generated by guide vanes in a 7.14 cm diameter nozzle with swirl numbers of 0.22, 0.36, 0.61 and 0.68 as determined by direct measurement of the linear and angular momentum fluxes for the jets. The parameters measured include those describing the self-preserving forms of the mean concentration field, the intensity and integral scale of the concentration fluctuations, and the intermittency for the jets without internal recirculation (swirl number < 0.6). Results show that swirling jets without internal recirculation are very similar in structure. The data for the two jets with internal recirculation zones are given as contour maps describing the mean concentration and fluctuation intensity fields. The results as a whole describe jets with weak to moderate swirl and indicate trends to be expected for jets with strong swirl.     

Die Fettreifbildung von Schokolade in Abhängigkeit von der verfahrenstechnischen Durchführung der Vor- und Erstarrungskristallisation

Dependence of Bloom-Formation in Chocolate from Technical Operation of Pre-Crystallization and Solidification The undesired bloom-formation in chocolate is caused by post-crystallization of cocoa fat during storage. Experiments were carried out systematically in order to reveal, in what manner the bloom-formation is dependent on pre-crystallization and solidification operations. It was found that chocolate is more resistent to bloom-formation, higher the amount of fat that crystallizes out during pre-crystallization. Increased stability of strongly pre-crystallized chocolate with respect to bloom-formation is due to transformation of cocoa fat into a stable crystalline state, already during pre-crystallization and solidification.     

Predictability and anxiety in speech by parents of female schizophrenics.

Investigated reported anomalies in verbal communication by parents of schizophrenics. Content structured speech samples from 15 sets of parents of good (G) and poor premorbid (P) schizophrenic daughters and nonpsychiatric controls (N) were obtained. These samples were analyzed by content area (neutral, aggression, dependency, and sex) for communicability, amount of speech anxiety, and source pathology. Communicativeness was assessed by cloze procedure using male and female college raters. Contrary to prediction, P parents tended to have the least amount of speech anxiety and the highest predictability, whereas N parents tended to have the highest speech anxiety and lowest predictability. However, raters tended to correctly identify which parents had the most disturbed offspring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gold recovery from non-metallic secondary raw materials by leaching with thiourea and adsorption on ion exchangers

Elemental gold on non-metallic secondary raw materials is easy to dissolve by leaching with sulphuric acid solutions of thiourea in the presence of an oxidant such as iron(III) sulphate or hydrogen peroxide. Leaching time is highly dependent upon oxidant concentration and the thickness of the gold coating. The gold goes into solution as the Au[SC(NH₂)₂]_2⁺ complex and can be removed almost completely using cationites, the gold residues being not greater than 6 μM. The gold-free leaching solution may be reused for leaching; the completely-loaded cationite resin (with a gold content of about 30–60 g/l) is burnt to recover the gold.A study of the adsorption of Au and Fe by cationites indicates that the adsorption of gold takes place purely by means of an ion-exchange mechanism, the bond of the gold complex being considerably stronger than that of the iron compounds.