Showing papers by "University of Memphis published in 1991"

An Examination of Ecologically Concerned Consumers and Their Intention to Purchase Ecologically Packaged Products

Abstract: Packaging is a major contributor to the escalating solid waste stream. This paper presents results of a study that attempts to determine variables which can be used to discriminate between groups t...

Photoprotection by melanin.

Abstract: This paper is an attempt to summarize the current state of information on melanin and epidermal melanin pigmentation (EMP) as photoprotective agents. The chemistry and biochemistry of melanin (the particle) and its interaction, in its various forms, with UV radiation are considered. Methods of attenuation of UV radiation are discussed in terms of structure and chemical constituents. Photoprotection by constitutive and facultative pigmentation is reviewed with minimum erythema dose (MED) as the end point. The issue of acclimatization to UV radiation is discussed in terms of UVB phototherapy for psoriasis. Finally, skin cancer is considered as an end point and the reduction of its incidence with pigment level is discussed. It is concluded that whilst EMP provides protection, its extent depends on the end point chosen for evaluation. MED is a convenient photobiological end point but is rather insensitive, whereas skin cancer is sensitive but impractical for laboratory studies. Our current state of knowledge of melanin lacks information on its absorption and scattering coefficients and its refractive index. Methods for the quantitative measurement of EMP are also urgently required.

State of the Art Procedures for Translating, Validating and Using Psychoeducational Tests in Cross-Cultural Assessment

Abstract: The purpose of this paper is to outline state of the art procedures for test translation, validation and use in multicultural, multilingual assessment. Guidelines are based on psychometric, linguistic, cultural and practical considerations. The authors encourage sound practice within the international psychological community in its assessment of children outside the intended source language and/or culture of available tests.

Social Interactions of Speech, and Language-Impaired Children

Abstract: Social interactions among preschool children were classified into four groups according to language ability: normally developing English, specific language impairment (SLI), speech impairment (SI),...

Mediators and moderators in meta-analysis: there's a reason we don't let dodo birds tell us which psychotherapies should have prizes.

Abstract: In primary studies, psychotherapy researchers frequently search for mediator and moderator variables that can help them understand the relationship between treatment and outcome. Yet a review of past psychotherapy meta-analyses revealed that none examined the possible role of mediator variables; and although all of them searched for moderators of study outcome, that search was generally not as complete as it could have been. This article illustrates methods for studying such mediator and moderator variables in meta-analysis, discusses their advantages and disadvantages, and shows how the inclusion of these variables can change interpretation of meta-analytic results. In particular, the perennial interpretation of past psychotherapy meta-analyses that therapeutic orientation makes no difference to outcome--or as the dodo bird put it: "Everyone has won and all must have prizes"--may be wrong. Orientation may make significant difference, but only by virtue of its moderating and mediating effects.

Reproductive endocrinology and mechanisms of breeding inhibition in cooperatively breeding Florida Scrub Jays Aphelocoma C. coerulescens)

Abstract: Although the ecological and evolutionary bases of cooperative breeding have received close scrutiny, few studies have explored the physiological mechanisms responsible for delayed breeding by helpers. We chose the Florida Scrub Jay, Aphelocoma c. coerulescens, to determine whether breeders and nonbreeders have different hormone profiles during the reproductive season. We found that male nonbreeders had significantly lower testosterone levels and higher progesterone levels than did male breeders. Nonbreeder and breeder males had similar plasma levels of corticosterone. Elevated plasma levels of progesterone in nonbreeder males may interfere with the reproductive activity at the behavioral or physiological level. Alternatively, progesterone may enable these nonbreeding males to express parental behavior in the absence of a parent/offspring relationship, but the occurrence of the highest levels of progesterone during nest building and egg laying supports the former interpretation. In females, we found that nonbreeders had significantly lower levels of estradiol and corticosterone than breeders. The low levels of primary sex steroid hormones in male and female nonbreeders may physiologically and behaviorally inhibit reproductive activity and suggest hat these individuals are reproductively incompetent. The absence of high levels of corticosterone in nonbreeders suggests that this reproductive inhibition is not due to glucocorticoid-mediated stress imposed by dominant breeders.

On the Evolution of Genome Size of Birds

Abstract: We measured genome size (nuclear DNA content) by fluorescence flow cytometry in 55 species of birds representing 12 different orders. Similar studies were performed in approximately 100 species by laboratories using absorption cytophotometry of Feulgen-stained nuclei. Although there have been apparent discrepancies in the assigned values for the species used as a reference, the values obtained in the different laboratories are generally in agreement. When the data are standardized in relation to a diploid (2C) value of 2.5 picograms (pg) of DNA for the domestic chicken (Gallus gallus domesticus), the mean for DNA content in 135 species representing 17 orders is 2.82 +/- 0.33 (SD) pg with a range of 2.0-3.8 pg. Thus the genome size of birds is the most conservative of any vertebrate class and, all values considered, is smaller and more uniform in size than previous estimates would indicate. This could be explained by a previously unexplored hypothesis: that the genome of birds has evolved from a small ancestral genome that was reduced before emergence of the protoavian.

Effect of physiologic hyperinsulinemia on glucose and lipid metabolism in cirrhosis.

Abstract: Insulin secretion and insulin sensitivity were evaluated in eight clinically stable cirrhotic patients and in 12 controls. OGTT was normal in cirrhotics but plasma insulin response was increased approximately twofold compared with controls. Subjects received a three-step (0.1, 0.5, 1.0 mU/kg.min) euglycemic insulin clamp with indirect calorimetry, [6-3H]-glucose, and [1-14C]-palmitate. During the two highest insulin infusion steps glucose uptake was impaired (3.33 +/- 0.31 vs. 5.06 +/- 0.40 mg/kg.min, P less than 0.01, and 6.09 +/- 0.50 vs. 7.95 +/- 0.52 mg/kg.min, P less than 0.01). Stimulation of glucose oxidation by insulin was normal; in contrast, nonoxidative glucose disposal (i.e., glycogen synthesis) was markedly reduced. Fasting (r = -0.553, P less than 0.01) and glucose-stimulated (r = -0.592, P less than 0.01) plasma insulin concentration correlated inversely with the severity of insulin resistance. Basal hepatic glucose production was normal in cirrhotics and suppressed normally with insulin. In postabsorptive state, plasma FFA conc (933 +/- 42 vs. 711 +/- 44 mumol/liter, P less than 0.01) and FFA turnover (9.08 +/- 1.20 vs. 6.03 +/- 0.53 mumol/kg.min, P less than 0.01) were elevated in cirrhotics despite basal hyperinsulinemia; basal FFA oxidation was similar in cirrhotic and control subjects. With low-dose insulin infusion, plasma FFA oxidation and turnover failed to suppress normally in cirrhotics. During the two higher insulin infusion steps, all parameters of FFA metabolism suppressed normally. In summary, stable cirrhotic patients with normal glucose tolerance exhibit marked insulin resistance secondary to the impaired nonoxidative glucose disposal. Our results suggest that chronic hyperinsulinism may be responsible for the insulin resistance observed in cirrhosis.

Combined chemical and mechanical effects on free radicals in UHMWPE joints during implantation.

Abstract: An electron spin resonance (ESR) technique is employed to determine the free radical distribution in the articulating surfaces of retrieved acetabular cups and knee-joint plateaus (retrieved after more than 6 years of implantation). Similar measurements made on samples prepared from cyclically stressed and unstressed cups, and on samples following oxidations in nitric acid and intralipid solutions provided sufficient data to gain more knowledge about the combined chemical and mechanical effects on PE free radicals during implantation. In UHMWPE free radicals are primarily initiated by gamma-ray sterilization; however, during implantation, peroxy (scission type) free radicals are formed and reach a maximum concentration level (equilibrium state) due to oxidation by chemical (hemoglobin and/or synovial fluids) environment of the joints. Subsequently, due to frictional heating and stress in the loading zones, free radical reaction is accelerated and their number is reduced only in those areas. This is consistent with the observations of a temperature rise in acetabular cups during in vitro frictional wear stress tests and in vivo telemetry observations, as reported by others. Compared with the previously reported SEM micrographs the low-free-radical regions are correlated with high-wear areas and the high-free-radical regions with the low-wear areas.

Assessment of the dynamics of vocal fold contact from the electroglottogram: data from normal male subjects.

Abstract: Electroglottographic (EGG) and acoustic records from 10 normal men prolonging the vowel /a/ at 60–68 dB, 70–78 dB, and 80–88 dB SPL were obtained. “Contact quotient” (EGG duty cycle) was shown to v...

A Comparative Evaluation of Adaptive Behavior in Children and Adolescents with Autism, Down Syndrome, and Normal Development.

Abstract: The adaptive behaviors of 20 autistic, 20 Down syndrome, and 20 developmentally normal children were compared using the Vineland Adaptive Behavior Scale. Unlike previous studies, we included a comparison group of very young normally developing children and matched subjects on overall adaptive behavior as well as several pertinent demographic characteristics. Findings revealed that, relative to children with Down syndrome or normal development, autistic children displayed significant and pervasive deficits in the acquisition of adaptive social skills, and greater variability in adaptive skills. These findings underscore the need to longitudinally assess the development of socialization in autistic children and further highlight the utility of the Vineland in operationally defining the nature of social dysfunction in autistic children.

Question answering in the context of stories

Abstract: In this study a model of question answering (called QUEST) is tested in the context of short stories. College students first read a story and then judged the quality of answers to questions about episodes in the story. The model could account for the goodness-of-answer judgments and decision latencies for 5 caterogies of questions : why, how, when, enablement, and consequence. QUEST specifies the information sources that are activated during question answering; the content of each information source is structured according to a theory of knowledge representation. QUEST specifies the convergence processes that dramatically narrow down the set of possible answers (activated from the information sources) to a small set of good answers to a question

Generic Strategies and Business Performance: an Empirical Study of the Screw Machine Products Industry

Abstract: SUMMARY Select businesses in industry may attempt to compete through distinct strategies. But some may be successful in adopting distinct strategic profiles while others may not prove successful. In this study it was expected that six different groups of businesses might be present in the empirical exploration – those competing successfully with the low cost strategy and those competing unsuccessfully with this strategy; those competing successfully with the differentiation strategy and those competing unsuccessfully with this strategy; and those competing successfully with low cost and differentiation strategies and those competing unsuccessfully with these strategies. The results of the investigation portray the presence of three strategic profiles. They are unsuccessful low cost businesses with the lowest performance, unsuccessful differentiated businesses with the second lowest performance, and successful businesses with combination strategies with the highest performance.

Frequency-importance and transfer functions for recorded CID W-22 word lists.

Abstract: Frequency-importance and transfer functions for the Technisonic Studios’ recordings of the CID W-22 word test are reported. These functions may be used to calculate Articulation Index (Al) values o...

Influence of Water Hardness and Salts on Survival and Physiological Characteristics of Striped Bass during and after Transport

Abstract: Physiological characteristics and survival of striped bass Morone saxatilis were evaluated during, and for 1 month after, transportation from a soft-water hatchery (hardness, 28 mg/ L) to a hard-water hatchery (hardness, 110 mg/L). Fish were transported and allowed to recover in either 1.0% sodium chloride, 0.1 % calcium chloride, or fresh water. The addition of 1.0% sodium chloride to the transportation and recovery waters increased survival, decreased the rise in plasma cortisol and plasma glucose concentrations, and reduced osmoregulatory dysfunction. The addition of 0.1% calcium chloride to the transport and recovery media or the use of fresh water did not significantly reduce the stress response of striped bass during and after transport. Striped bass had significantly better survival and lower stress response when transported and allowed to recover in 1.0% sodium chloride than when treated in fresh water or 0.1 % calcium chloride, which is generally used in soft-water hatcheries to increase...

The Men Who Care: An Analysis of Male Primary Caregivers Who Care for Frail Elderly at Home

Abstract: The geriatric care literature has paid little attention to a small, yet sizable group of informal caregivers—men who care for a frail elderly relative at home. This lack of attention to male caregivers is not surprising because caregiving is traditionally regarded as a "woman's job," usually assumed by a grown daughter or daughter-in-law of the care recipient. This study finds that 27% of the informal caregivers surveyed by the 1982 to 1984 National Long-Term Care Demonstration (the channeling study) are men. Male caregivers are predominantly the husbands of frail, elderly women, and they are more willing to abandon gender roles than are other male caregivers. Further, male caregivers in general appear to be healthier, more satisfied with life, more active in the labor market, and report less financial and physical stress from caregiving than do female caregivers. With the exception of spouses, our findings support the existing literature regarding the existence of strong gender differences in caregiving ...

EQCM studies of film growth, redox cycling, and charge trapping of n-doped and p-doped poly(thiophene)

Abstract: : The electrochemical quartz crystal microbalance (EQCM) is used to monitor mass changes which accompany the growth, redox cycling, and charge trapping of thin films of poly(thiophene) (PT) at Au electrodes under potentiodynamic conditions. Mechanical conductance spectra of the EQCM/PT composite resonators reveal that the PT films behave as rigid layers, allowing use of the Sauerbrey equation for calculation of quantitative mass changes from the frequency changes recorded with the EQCM. Film growth by oxidation of 2,2'- bithiophene appears to proceed by production of soluble, short chain oligomers following oxidation, with precipitation a consequence of both reduction and increasing chain length.

The effects of different feedback strategies using computer-administered multiple-choice questions as instruction

Abstract: This study investigated the effects of using different forms of computer-based feedback on high school students' learning of science material. The basic design consisted of two conditions of instructional support (text and questions vs. questions only), two testings (immediate vs. retention), five levels of similarity between lesson and posttest questions, and five feedback conditions: knowledge of correct response (KCR), delayed KCR, answer until correct (AUC), questions only (no feedback), and no questions. Results showed significant benefits for feedback over no feedback, with AUC becoming more advantageous and delayed feedback less so as lesson-posttest question similarity decreased. Also, with decreased question similarity and the availability of supporting text, overall feedback effects tended to decrease. The results are discussed in terms of the information processing effects of the different feedback forms, a factor that CBI designers often fail to exploit in planning feedback conditions.

Seismic wave attenuation in volcanic rocks from VSP experiments

Abstract: Seismic wave attenuation in the Columbia Plateau basalts and Snake River Plain volcanics was analyzed using vertical seismic profiling (VSP) data. The computation of attenuation coefficients is based on fitting a straight line to the logarithm of amplitude ratios computed for fixed values of frequency and variable depth. This approach does not require any assumptions on the dependence of Q on frequency. For the Columbia Plateau basalts, the attenuation coefficients obtained from the field data are smaller than those computed from the synthetic VSP generated using the sonic and density logs, indicating that the observed attenuation is related to scattering effects and is substantially larger than the intrinsic attenuation of basalt. Therefore, it is concluded that only a lower bound for Q can be established, in agreement with recent findings by other authors. The effective attenuation of seismic energy in basalts (about 1.1×10-4dbs/m for the peak frequency) is comparable to the effective attenuation observ...

Degradation and bound residue formation of atrazine in a Western Tennessee soil

Abstract: Biological and physical degradation, and metabolite and soil-bound residue formation, of [U-ring-14C]atrazine (2-chloro-4-[ethylamino]-6-[isopropylamino]-1,3,5-triazine) were characterized in a western Tennessee soil using laboratory and field assays. Biological mineralization of [14C]atrazine was examined in the laboratory using intact surface soil cores in sealed microcosms. Physical mineralization was determined using gamma-radiation-sterilized soil microcosms. Metabolites measured were deethylatrazine (DEA), deisopropylatrazine (DIA), dealkylatrazine (DAA) and hydroxyatrazine (HYA). Atrazine was applied at a rate of 2.2 kg/ha (˜ 5.6 μg/g soil) to soil microcosms in two studies and 3.2 kg/ha to the field. Evolution of 14CO2 from [14C]atrazine in nonirradiated soil microcosms increased to 12 and 28% of the radiolabel added after 180 d incubation. Irradiated soil microcosms evolved less than 0.07% of the radiolabel as 14CO2 for both studies after the same period. The concentrations of metabolites throughout the laboratory and field studies were: HYA > DEA > DIA > DAA. The highest concentration of HYA detected during microcosm and field studies was approximately 0.5 μg/g soil. Atrazine dissipation rates and metabolite production in nonirradiated microcosms were comparable to field results. Atrazine concentrations after 180 d in nonirradiated microcosm and field samples were lower than HYA, and either equivalent to or greater than DEA. The DAA was not detected throughout microcosm or field studies. Rates of dissipation for atrazine followed first-order kinetics. Atrazine half-life, based on extractable residues, was approximately 21 d in the microcosm studies, compared to 14 d in surface field soil. Extractable 14C residues sampled from nonirradiated microcosms decreased in concentration during the incubation period. Soil-bound 14C residues increased and, at the termination of the two studies, accounted for 39 and 43% of the radioactivity added to nonirradiated microcosms. Bound 14C residues in irradiated microcosms accounted for 49 and 48% of the activity after 180 d. Similarity of results between microcosm and field studies suggests that those microcosms may be useful for predicting the fate of atrazine in surface soil.

The impact of role stressors and personal resources on the stress experience of professional women

Abstract: This study explored the contributions of role stressors and personal resources in predicting strain symptoms experienced by 117 professional women employed full-time in academia. Results of multiple regression analyses revealed that, while role stressors alone accounted for only a moderate amount of the variance in reported strain symptoms, 51% of the variance was explained when both stressors and personal resources were combined. Women who experienced higher levels of personal control and social support as well as a greater number of roles occupied reported lower levels of strain symptoms. These results support the use of a transactional model of stress in future multiple role research.

Reactions of beginning counselors to situations involving death and dying

Abstract: It has commonly been assumed by thanatologists that client problems centering on death and dying are particularly demanding and difficult for the mental health professional. The present study tested this assumption by asking 81 beginning counselors to rate their degree of comfort with 15 counseling scenarios, 5 of which involved death or loss (e.g., terminal illness, suicide, AIDS, grief) and 10 of which concerned other focal issues (e.g., rape, marital problems). As predicted, counselors rated situations involving death and dying as substantially more uncomfortable than other presenting problems. However, counselors' levels of experience and personal death threat were unrelated to their response to death situations, leaving the cause of their discomfort with such situations unexplained.