Showing papers by "University of Arkansas published in 1983"

Psychological functioning of children in a battered women's shelter: a preliminary investigation.

Abstract: Self-concept, anxiety level, and problem behavior of 65 child residents of a battered women's shelter were assessed using self-report measures and checklists completed by mothers, staff, and teachers. Findings included a below-average self-concept score for the preschool group, more aggressive behavior in school-age shelter boys than in girls, and a pervasive tendency for mothers to rate their children more negatively than did other observers.

The Influence of Speech Rate Stereotypes and Rate Similarity or Listeners' Evaluations of Speakers:

Abstract: In this study, the effects of speaker speech rate level, the degree of similarity between listener and speaker rates, and context on listeners' evaluative judgments of speakers were examined. After their own speech rates were assessed, subjects listened to passages of a male speaker, using a fast, moderate or slow speech rate. Also, subjects were told the passages were excerpts from either an informal conversation or an employment interview. After listening to the speech sample, subjects evaluated the speaker on competence and social attractiveness measures. Results indicated that listeners found a speaker with moderate to relative faster rates (actual and perceived) more competent and socially attractive than a speaker with slower rates. Listeners also preferred speakers with rates similar to or marginally faster than their own. The results regarding context were equivocal. Neither main nor interaction effects involving context emerged on either the competence or social attractiveness measures. However, ...

The Oklo phenomenon

Abstract: Until recently, scientists believed that the chemical elements were synthesized only in stars. The discovery of the Oklo phenomenon in the Republic of Gabon in 1972 has revealed, however, that a nuclear “fire” had existed on the earth and largescale transmutations of the elements were occurring on our planet 1.7·109 years ago. The formation of natural (or Pre-Fermi) reactors is closely related to the appearance of life on our planet earth. The Pre-Fermi reactors were probably never formed until about 2·109 years ago, when oxygen was injected into the earth's atmosphere by a new generation of living organisms carrying out photosynthesis.

Altered Microsomal Phospholipid Composition in the Streptozotocin Diabetic Rat

Abstract: Streptozotocin diabetes in the rat alters liver microsomal membrane fatty acid composition. The present study was undertaken to determine if such changes in fatty acid composition were due to changes in the amount of individual phosphoglycerides or to disproportionate changes in fatty acid composition in any of the individual phosphoglycerides. The diabetic animals showed a small increase in total microsomal phospholipid, which is due to a selective increase in the phosphatidylethanolamine fraction. The changes in fatty acid composition in the total lipid extract (decreased palmitoleic, oleic and arachidonic acids and increased linoleic and docosahexaenoic acids) from the diabetic animals were present in both the major phosphoglycerides, phosphatidylcholine and phosphatidylethanolamine, with very little change in fatty acid composition in the phosphatidylserine and inositol fraction. Further studies are necessary to delineate the cause of the abnormal membrane phospholipid composition in the diabetic animal.

Gross morphological analysis of limb regeneration in postmetamorphic adult Ambystoma.

Abstract: Due to the great disparity between regeneration times for the larval salamander (40 days), axolotl (30+ days), newt (44 days), and adult salamander (155 to 370 days), a staging system was devised so correlative comparisons could be made between regenerative model systems. The sequence was based on two criteria: (1) the stages should be similar to previously reported sequences for the newt, axolotl, and larval salamander, and (2) the stages must be readily recognizable by examination of the external morphology in the living state. Postmetamorphic adult land-phase Ambystoma were amputated through the forearm, placed within survival conditions, and observed until regeneration was completed. Of the initial 160 salamanders, 157 (98%) progressed through 11 clearly defined stages of regeneration. A side-by-side comparison of the staging sequence for land and aquatic phase urodeles is given along with a summary of key external morphological characteristics for the adult salamander. It was noted that as the length of time for regeneration decreased, the relative ratio of the nerves innervating the limb (spinal nerves 4, 5, and 6) increased for the four species of Ambystoma examined: A. annulatum, 324 to 370 days postamputation (dpa) with a 1:1:1 neural tissue ratio; A. maculatum, 255 to 300 dpa with a 2:2:1 ratio; A. texanum, 215 to 250 dpa with a 2:2:2 ratio; and A. tigranum, 155 to 180 dpa with a 2:3:3 ratio.

Comparison of adriamycin‐containing chemotherapy (MOP‐BAP) with MOPP‐bleomycin in the management of advanced Hodgkin‐s disease a southwest oncology group study

Abstract: Between 1974 and 1978, 315 eligible patients with advanced Hodgkin-s disease (HD) without prior chemotherapy were randomized to MOPP plus low-dose bleomycin or the same agents plus Adriamycin (in 1 of 2 schedules). The results of the two Adriamycin-containing schedules were similar and were, therefore, combined as „MOP-BAP and compared to MOPP-Bleo. All patients completed remission induction therapy with a median time on study of 47 months. Of 291 evaluable patients, the complete remission rate was 77% for 166 patients treated with MOP-BAP compared to 67% for 125 patients receiving MOPP-Bleo (P = 0.05, one-sided test). Among patients with more favorable pretreatment prognostic factors, MOP-BAP produced a higher CR rate than MOPP-Bleo (patients with hemoglobin ≥ 12 g/dl, 85 versus 67%, P = 0.01; those with a performance status of 70-100%, 81 versus 70%, P = 0.03; those without bone marrow involvement, 81 versus 68%, P = 0.03, those older than age of 40 years, 79 versus 62%, P = 0.03; those who were asymptomatic [A], 94 versus 77%, P = 0.04; and those without any prior therapy, 75 versus 63%, P = 0.04). CR duration and overall survival were similar for the two treatments. However, survival was better for patients with favorable pretreatment prognostic factors treated with MOP-BAP compared to MOPP-Bleo (those who were asymptomatic [P = 0.08], without bone marrow involvement [P = 0.04], and with nearly normal initial hemoglobin levels [P = 0.02]). MOP-BAP was associated with less nausea and vomiting and significantly less thrombocytopenia than MOPP-Bleo (P = 0.01). For patients with prognostically more favorable types of HD, the use of an initial Adriamycin-containing MOPP regimen (MOP-BAP) offers a higher complete remission rate, less acute toxicity and improved survival compared to MOPP-Bleo.

Exponential decay, recurrences, and quantum-mechanical spreading in a quasicontinuum model

Abstract: We consider a single quantum state coupled equally to each of a set of evenly spaced quasicontinuum (QC) states. We obtain a delay differential equation for the initial-state probability amplitude, and this equation is solved analytically. When the QC-level spacing goes to zero, the initial-state probability decays exactly exponentially. For finite QC-level spacings, however, there are recurrences of initial-state probability. We discuss Tolman's ''quantum-mechanical spreading'' of probability and also a classical analog of our model.

Theoretical equilibrium geometry, vibrational frequencies and the first electronic transition energy of HCC

Abstract: Ab initio calculations with the 6–311 G** basis set and all single and double excitations in the CI treatment have been carried out to determine the structure of the HCC radical. The theoretical geometry of R(CC) = 1·209, r(CH) = 1·067 A (or 1·205 and 1·063, respectively, if corrected for residual errors) is in excellent accordance with the experimental rotational constant. The calculated harmonic vibrational frequencies are v 1 ⋍ 3450, v 2 ⋍ 540 and v 3 ⋍ 2040 cm-1. An extremely low energy around 2000 cm-1 is obtained for the first electronic transition A 2II ← X 2∑. Results for the excited state are also given. The theoretical vibrational frequencies, with all possible errors taken into account, are inconsistent with the accepted interpretations of the few experimental results. It is shown, however, that a complete reinterpretation of the spectroscopic observations is possible, by which the present calculations fit with the recent gas phase infrared laser spectroscopic data but remain in definite contra...

Hepatic involvement in hairy cell leukemia

Abstract: Nineteen patients with hairy cell leukemia were studied in order to define the hepatic changes in this disease and to correlate the morphologic changes in the liver with the clinical and biochemical findings. Although only eight of the patients had hepatomegaly, all 19 had microscopic mononuclear cell infiltration in the sinusoids or the portal areas or both. The severity of mononuclear infiltration in the liver correlated poorly with the size of the liver or spleen, the biochemical changes, or number of hairy cells in the blood. Abnormal serum biochemical values were present occasionally and were usually due to associated diseases or to complications of this disease. Elevated serum alkaline phosphatase activity was noted in four patients; three of them bad granulomatous lesions in the liver. Unless the characteristic “clear cell” pattern is seen, the hepatic mononuclear cell infiltration may not be diagnostic of hairy cell leukemia and, in many instances, may not even be suggestive of neoplasia. A new technique for demonstrating tartrate-resistant acid phosphatase activity in methacrylate-embedded sections was developed, which allowed identification of hairy cells in the liver biopsy specimens of all five patients so studied. The authors concluded that liver involvement is common in this disease.

Autotoxic inhibition of seed germination by Typha latifolia: an evaluation.

Abstract: Seeds of Typha latifolia were exposed to leaf extracts, leaf pieces, and soil water from adult plants of T. latifolia. In liquid culture, only extracts of concentration greater than or equal to 3% (dry weight to volume) inhibited seed germination. Adding soil to the liquid cultures increased the inhibition of seed germination by extracts. The inhibitory effects of extracts were correlated with the development of water molds in the cultures; prior to the development of water molds, even 15% extracts were not inhibitory to germination. In contrast to results from extracts; neither 3% concentrations of senesced leaf pieces nor soil surface water from one year old pots of T. latifolia had any detrimental effects on germination. Seeds sown into pots containing established T. latifolia germinated as well as seeds sown into control pots. These results do not support the contention that T. latifolia inhibits the germination of its seeds by the release of allelopathic substances.

Diel Drift and Feeding of Channel Catfish Alevins in the Illinois River, Arkansas

Abstract: The food habits of 317 channel catfish Ictalurus punctatus alevins (standard length 14–16 mm) collected from the Illinois River, Arkansas were investigated to determine if the drifting alevins were using drifting invertebrates as a food resource. Drift of alevins coincided with increases in fullness of their stomachs, but alevins had been feeding predominantly on chironomid larvae and pupae, which were rare in the drift and riffle substrate. Alevins apparently fed on chironomids in upstream pools and accidentally encountered swift currents that caused them to drift downstream. If so, drift was a consequence of feeding activity, not an aid to it.

The effect of plants on the host relations of a specialist parasitoid of heliothis larvae

Abstract: Microplitis croceipes (Cresson), a parasitoid of Heliothis larvae, was reared on 9 host insect/plant combinations. In general, parasitoid survivorship was (1) higher in host larvae that were reared on cotton than in hosts reared on either bean or tomato, (2) higher in H. zea hosts than in H. virescens and (3) higher in a laboratory strain of H. zea than in a wild strain. A series of parasitoid oviposition preference tests showed that wasps laid more eggs in host larvae on cotton plants than on bean and more on bean than on tomato. However, the wasps did not distinquish between H. zea and H. virescens hosts. Wasp oviposition preferences were not conditioned by the host insect/plant combination in which the parasitoid developed. These results indicate that the plant on which host larvae feed is an important factor in determining both the likelihood of parasitoid attack and the probability of successful parasitism. ZUSAMMENFASSUNG Der Einfluss der Pflanze auf die Wirtsbeziehungen eines spezialisierten Parasiten von Heliothis-Larven. Microplitis croceipes (Cresson), Parasit der Heliothis-Larven, wurde in 9 Kombinationen von Wirtsinsekt/Wirtspflanze gezuchtet. Im allgemeinen war das Ueberleben der Parasiten (1) besser in Wirtsraupen von Baumwolle als von Bohnen oder Tomaten, (2) besser in H. zea als in H. virescens und (3) besser in laborgezuchteten H. zea als in Raupen aus dem Freiland. Mehrere Versuche uber die Eiablagepraferenz der Parasiten zeigten, dass mehr Eier in Raupen von Baumwolle als in Raupen von Bohnen oder gar von Tomaten abgelegt wurden. Die Wespen unterschieden aber nicht zwischen H. zea und H. virescens. Die Eiablagepraferenzen waren unabhangig von den Kombinationen Wirtsinsekt/Wirtspflanze, in denen sich die Parasiten entwickelt hatten. Die Ergebnisse weisen darauf hin, dass die Pflanze, auf der die Wirtsraupe frisst, wichtig ist fur die Wahrscheinlichkeit eines Parasitenangriffs und fur den Erfolg der Parasitierung.

Detection and Control of Soymilk Astringency

Abstract: Soymilk was made less astringent by the addition of skimmed cow's milk (SCM), CaSO4 or citric acid. The additions of CaSO4 and citric acid were not sufficient to cause visible separation of soymilk solids, but there was some difference in mouthfeel due to the additions. Warm temperatures (65°C) of the soymilk resulted in a loss of astringency compared to sensory evaluation at room temperature or 4°C. Analyses for total polyphenols showed statistically significant decreases in apparent polyphenol content per gram of soymilk solids with the first level of addition of SCM, CaSO4, or citric acid but not with subsequent additions.

Digestive anatomy of Halella azteca (Crustacea, Amphipoda).

Abstract: The digestive tract of the freshwater amphipod Hyalella azteca is a straight but differentiated tube consisting of foregut, midgut, and hindgut divisions. The foregut is subdivided into a tubular esophagus, a cardiac stomach, and a pyloric stomach. The cuticular lining of the cardiac stomach is elaborated into a set of food-crushing plates and ossicles, the gastric mill, while the pyloric cuticle forms a complex straining and pressing mechanism. Nine caeca arise from the midgut, seven anteriorly and two posteriorly. Four of the anterior caeca, the hepatopancreatic caeca, are believed to be the primary sites of digestion and absorption. The remaining caeca may be absorptive, secretory, or both. The much-folded hindgut wall is capable of great distention by extrinsic muscle action for water intake to aid in flushing fecal material out of the anus; such action also may stimulate antiperistalsis by intrinsic rectal muscles.

The treatment of bulimia (binge‐eating and self‐induced vomiting): A quasi‐experimental investigation of the effects of stimulus narrowing, self‐reinforcement and self‐control relaxation

Abstract: Previous research has suggested that inappropriate stimulus control and psychological stress may exercise functional control over eating disturbances such as binge-eating and self-induced vomiting (bulimia). This report is a single-case study of a 26-year-old bulimic female in which these factors were hypothesized to be functional elements. The intervention used a self-reinforcement program to establish appropriate stimulus control over proper nutritional habits (Stimulus Narrowing). Stimulus Narrowing was successfully implemented utilizing self-reinforcement, but Stimulus Narrowing did not reduce bulimia. Self-control relaxation was then implemented and was followed by an apparent reduction in the frequency of bulimic episodes. The results suggest that the “treatment package” of stimulus narrowing, self-reinforcement and self-control relaxation may be useful in the treatment of bulimia. Methodological and clinical implications are discussed and recommendations for future experimental-clinical research are offered.

Ab initio studies of structural features not easily amenable to experiment: Part 26. Conformational analysis and study of the self-induced molecular asymmetry of glycerol

Abstract: The structures of ten conformations of glycerol have been refined without any geometrical constraints by ab initio gradient relaxation on the 4-21G level. The compound can exist in forms which possess a symmetry plane, and in forms in which asymmetry is induced by intramolecular interactions. The two most stable forms are of type αγ (Fig. 1) and γγ (Fig. 9). The latter is characterized by a chair-type six-membered ring closed by hydrogen bonding. The calculations make it possible to estimate the positions of the hydrogen atoms which are not known from experimental work. Intramolecular hydrogen bonds are approximately oriented along the directions conventionally defined for σ-,π-and sp 3 -type electron lone pairs on oxygen. The results also make it possible to describe the differences in local geometry which can cause the central carbon atom to be chiral. This is in contrast to presentations in which the chemical equivalence of the terminal CH 2 OH groups in glycerol is correlated with the assumption that the central carbon atom is symmetric. It is postulated that, rather, the chemical equivalence of the terminal groups can involve the rapidly interconverting equilibrium of asymmetric, enantiomeric forms. The results thus demonstrate that details of molecular local geometries can be important in interpretations of chemical reactivity.