Showing papers by "University of Alabama published in 1994"

Review of particle properties.

Abstract: This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the first time we cover searches for evidence of extra dimensions (both in the particle listings and in a new review). Another new review is on Grand Unified Theories. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Effects of Early Intervention on Intellectual and Academic Achievement: A Follow‐up Study of Children from Low‐Income Families

Abstract: Follow-up data, obtained 4-7 years after intervention ended, are presented for the Carolina Abecedarian Project, an experimental study of early childhood educational intervention for children from poverty families. Subjects were randomly assigned to 1 of 4 intervention conditions: educational treatment from infancy through 3 years in public school (up to age 8); preschool treatment only (infancy to age 5); primary school treatment only (age 5-8 years), or an untreated control group. Positive effects of preschool treatment on intellectual development and academic achievement were maintained through age 12. School-age treatment alone was less effective. Results generally supported an intensity hypothesis in that scores on cognitive and academic achievement measures increased as duration of treatment increased.

Psychopathy and conduct problems in children.

Abstract: Factor analysis of a measure of psychopathy was conducted in a sample of 95 clinic-referred children between the ages of 6 and 13 years. These analyses revealed 2 dimensions of behavior, one associated with impulsivity and conduct problems (I/CP) and one associated with the interpersonal and motivational aspects of psychopathy (callous/unemotional: CU). In a subset of this sample (n = 64), analyses indicated that scores on the I/CP factor were highly associated with traditional measures of conduct problems. In contrast, scores derived from the CU factor were only moderately associated with measures of conduct problems and exhibited a different pattern of associations on several criteria that have been associated with psychopathy (e.g., sensation seeking) or childhood antisocial behavior (e.g., low intelligence, poor school achievement, and anxiety). These analyses suggest that psychopathic personality features and conduct problems are independent, yet interacting, constructs in children, analogous to findings in the adult literature.

Critical Issues in Qualitative Research Methods

Abstract: In what case do you like reading so much? What about the type of the critical issues in qualitative research methods book? The needs to read? Well, everybody has their own reason why should read some books. Mostly, it will relate to their necessity to get knowledge from the book and want to read just to get entertainment. Novels, story book, and other entertaining books become so popular this day. Besides, the scientific books will also be the best reason to choose, especially for the students, teachers, doctors, businessman, and other professions who are fond of reading.

Purification of C60 and C70 by selective complexation with calixarenes

Abstract: MOLECULAR complexation of fullerenes in host–guest complexes has the potential to afford efficient large-scale purification of fullerenes1. This method would avoid the losses inherent in the chromatographic techniques currently in use, which arise from irreversible absorption on the stationary phase2. Several host-guest interactions have been reported for C60, including the formation of complexes with 1,4-hydroquinone3,4, azacrown compounds5, certain water-soluble macrocycles such as γ-cyclodextrin6–8, and complexation between C60 and an iridium phosphine in which pendant groups attached to a phosphorus atom form a cradle for an adjacent C60 molecule9. Other relevant studies are the inclusion of C60 into a microporous aluminophosphate10 and the formation of a charge-transfer complex between C60 and a thiafulvalene11. Here we show that both C60 and C70 will form discrete complexes with calixarenes, bowl-shaped macrocycles with hydrophobic cavities. Complexation of p-Bu'-calix[8]arene with a mixture of the toluene extract of 'crude' fullerene soot, followed by a series of recrystallizations, affords >99.5% pure C6. Our approach could lead to a substantial reduction in the cost of purifying C60 and C70.

Treatment of myocardial infarction in the United States (1990 to 1993). Observations from the National Registry of Myocardial Infarction.

Abstract: BACKGROUNDMultiple clinical trials have provided guidelines for the treatment of myocardial infarction, but there is little documentation as to how consistently their recommendations are being impl...

Electrochemistry and the environment

Abstract: Advances in electrochemical methods for pollutant remediation, recycling and sensing are reviewed. Additionally, applications of these methods in the drinking water industry, and for disinfection scenarios are discussed. Lastly, new electrode materials for environmental applications are described. In a companion review, photoelectrochemical methods will be discussed.

High frequency volume coils for clinical NMR imaging and spectroscopy.

Abstract: A tuned transmission line resonator has been developed in theory and in practical design for the clinical NMR volume coil application at 4.1 tesla. The distributed circuit transmission line resonator was designed for high frequency, large conductive volume applications where conventional lumped element coil designs perform less efficiently. The resonator design has made use of a resonant coaxial cavity, which could be variably tuned to the Larmor frequency of interest by tunable transmission line elements. Large head- and body-sized volumes, high efficiencies, and broad tuning ranges have been shown to be characteristic of the transmission line resonator to frequencies of 500 MHz. The B1 homogeneity of the resonator has been demonstrated to be a function of the electromagnetic properties of the load itself. By numerically solving Maxwell's equations for the fully time-dependent B1 field, coil homogeneity was predicted with finite-element models of anatomic structure, and inhomogeneities corrected for. A how-to exposition of coil design and construction has been included. Simple methods of quadrature driving and double tuning the transmission line resonator have also been presented. Human head images obtained with a tuned transmission line resonator at 175 MHz have clearly demonstrated uncompromised high field advantages of signal-to-noise and spatial resolution.

Organizational Commitment: One of Many Commitments or Key Mediating Construct?

Abstract: This study developed and tested two rival views of how organizational commitment can be reconceptualized to accommodate both global organizational commitment and constituency-specific commitments. ...

Extensive reorganization of the somatosensory cortex in adult humans after nervous system injury

Abstract: MAGNETIC source imaging revealed that the topographic representation in the somatosensory cortex of the face area in upper extremity amputees was shifted an average of 1.5 cm toward the area that would normally receive input from the now absent nerves supplying the hand and fingers. Observed alterat

Software development cost estimation using function points

Abstract: This paper presents an assessment of several published statistical regression models that relate software development effort to software size measured in function points. The principal concern with published models has to do with the number of observations upon which the models were based and inattention to the assumptions inherent in regression analysis. The research describes appropriate statistical procedures in the context of a case study based on function point data for 104 software development projects and discusses limitations of the resulting model in estimating development effort. The paper also focuses on a problem with the current method for measuring function points that constrains the effective use of function points in regression models and suggests a modification to the approach that should enhance the accuracy of prediction models based on function points in the future. >

The amphipathic alpha helix: a multifunctional structural motif in plasma apolipoproteins.

Abstract: Publisher Summary The dominant structural motif of the peripheral apolipoproteins is the amphipathic helix, which is responsible for the reversible association of these proteins with lipids, as well as for many biological functions mediated by these apolipoproteins. This chapter reviews the different classes of amphipathic helices, using a combination of powerful computer programs to develop a comparison database and to analyze these structures. It also discusses their evolutionary origins, physical-chemical properties, X-ray structure determination, and conformational analysis. Although the structures of these lipoprotein classes are similar, they differ in relative proportion of lipids, in the apolipoprotein: lipid ratio and in the apolipoprotein species. The amphipathic α helix plays a pivotal role in the structure and functions of the exchangeable apolipoproteins. Site-directed mutagenesis and other molecular biology-based techniques are available for probing the structural motif. The location and properties of the amphipathic helices in apolipoproteins and the results are compared with recently developed and ever-expanding computer methods for the location and characterization. A variety of structure-function studies, including the activation of lipoprotein lipase, receptor recognition, lecithin-cholesterol acyltransferase (LCAT) activation, and antiviral and anti-inflammatory activities are also discussed.

Efficacy of psychosocial treatments for geriatric depression: A quantitative review.

Abstract: A meta-analysis of 17 studies examined the efficacy of psychosocial treatments for depression among older adults. Studies were included only if a comparison was made to a control condition (no-, delayed-, or placebo-treatment) or another psychosocial intervention. Results indicated that treatments were reliably more effective than no-treatment on self-rated and clinician-rated measures of depression. Effect sizes for studies involving participants with major depression disorder were also reliably different from zero, as were effect sizes from studies involving participants with less severe levels of depression. These findings compare favorably with several other quantitative reviews of treatments for depression. Results suggest more balanced presentations of the potential benefits of psychosocial interventions are warranted.

Performance of Four Computer-Based Diagnostic Systems

Abstract: Background Computer-based diagnostic systems are available commercially, but there has been limited evaluation of their performance. We assessed the diagnostic capabilities of four internal medicine diagnostic systems: Dxplain, Iliad, Meditel, and QMR. Methods Ten expert clinicians created a set of 105 diagnostically challenging clinical case summaries involving actual patients. Clinical data were entered into each program with the vocabulary provided by the program's developer. Each of the systems produced a ranked list of possible diagnoses for each patient, as did the group of experts. We calculated scores on several performance measures for each computer program. Results No single computer program scored better than the others on all performance measures. Among all cases and all programs, the proportion of correct diagnoses ranged from 0.52 to 0.71, and the mean proportion of relevant diagnoses ranged from 0.19 to 0.37. On average, less than half the diagnoses on the experts' original list of reasonab...

Identification of the TCL1 gene involved in T-cell malignancies.

Abstract: The TCL1 locus on chromosome 14q32.1 is frequently involved in chromosomal translocations and inversions with one of the T-cell receptor loci in human T-cell leukemias and lymphomas. The chromosome 14 region translocated or rearranged involves approximately 350 kb of DNA at chromosome band 14q32.1. Within this region we have identified a gene coding for a 1.3-kb transcript, expressed only in restricted subsets of cells within the lymphoid lineage and expressed at high levels in leukemic cells carrying a t(14;14)(q11;q32) chromosome translocation or a inv(14)(q11;q32) chromosome inversion. The cognate cDNA sequence reveals an open reading frame of 342 nt encoding a protein of 14 kDa. The TCL1 gene sequence, which, to our knowledge, shows no sequence homology with other human genes, is preferentially expressed early in T- and B-lymphocyte differentiation.

Ball and Socket Nanostructures: New Supramolecular Chemistry Based on Cyclotriveratrylene

Abstract: This paper outlines new vistas for the inclusion chemistry of hosts based upon the cyclotriveratrylene motif. A simple method of retrieving pure fullerenes from fullerite without the use of chromatographic techniques has been outlined, and a new class of ball and socket-type inclusion species has been realized by simple modification of either host or guest electronic and steric properties. 14 refs., 2 figs.

The Structure of Marketing Channel Relationships

Abstract: Distribution channel research has been advanced in recent years by contributions based on the political economy paradigm, transaction cost analysis, and relationship marketing. Drawing on these bodies of thought, we propose a new conceptualization of the structure of marketing channel relationships. Relationship structure is defined in terms of decision-making structure and operational integration. The proposed model of channel structure antecedents and consequences is consistent with the major research paradigms but extends beyond simple categorical assemblages of constructs to provide an ordered set of relationships based on theory and empirical research. This conceptualization reconciles some apparent contradictions in the literature and provides a clear focus for structure, process, and performance research in channels.

Environmentally constrained economic dispatch using the LaGrangian relaxation method

Abstract: This paper presents a general formulation of the environmentally constrained economic dispatch (ECED) problem based on the requirements of Clean Air Act Amendments of 1990 and others which may be imposed by local air quality regulations. The formulation considers multiple NO/sub x/ constraints and incorporates the utilization of the affected units (those named in the legislation) along with SO/sub 2/ constraints. It also proposes a new algorithm to solve the problem for large power systems. This algorithm has the ability to handle a large number of various types of linear and nonlinear environmental constraints. It is reliable, and viable for both offline and online applications. Test results on a large size power system demonstrate the possible savings which can be realized by using the algorithm. Details of the problem formulation and the solution technique are given in the paper. >

Occipital horn syndrome and a mild Menkes phenotype associated with splice site mutations at the MNK locus.

Abstract: We have found mutations in the Menkes disease gene (MNK) which impair, but do not abolish, correct mRNA splicing in patients with less severe clinical phenotypes. In one family, four males aged 2–36 years with a distinctive Menkes variant have a mutation at the +3 position of a splice donor site near the 3′ end of the Menkes coding sequence that is associated with exon skipping and a stable mutant transcript. In an unrelated 15-year-old male with typical occipital horn syndrome, a point mutation at the −2 exonic position of a splice donor site in the middle of the gene causes exon-skipping and activation of a cryptic splice acceptor site. In both mutations, maintenance of some normal splicing is demonstrable by RT-PCR, cDNA sequencing and ribonuclease protection.

Economic dispatch in view of the Clean Air Act of 1990

Abstract: This paper discusses the impact of the enactment of the Clean Air Act of 1990 on the current industry practices as related to the economic dispatch problem. The problem was investigated in view of the new SO/sub 2/ emissions and underutilization constraints. Detailed problem formulations are presented and tools to evaluate different compliance plans and operation strategies are proposed. Test results on a large size power system are also included in the paper. >

Megadose corticosteroids in multiple sclerosis.

Abstract: Although the etiology and pathogenesis of multiple sclerosis (MS) are unknown, an extensive literature, suggesting that abnormalities in the immune system have an important role in mediating MS attacks, has led to the use of many experimental treatments with immunomodulatory effects. Therapy with immunosuppressives such as azathioprine,l cyc loph~sphamide ,~~~ and cyclosporine A4 have all had relatively small benefit on the course of the chronic progressive form of MS. Only two randomized, multicenter, placebo-controlled treatment trials with enough patients to reach firm, statistically valid conclusions have been performed on relapsing-remitting disease. The first5p6 demonstrated that alternate-day 8 million international units of subcutaneously injected interferon-@ in patients with a history of relapsing-remitting MS reduced the attack rate 34% per year, nearly doubled the time to the next exacerbation, and reduced new MRI lesions compared with placebo-treated patients over 2 years. The second and most recent study, the Longitudinal Optic Neuritis Study (LONS),' investigated corticosteroids, one of the first immunomodulatory therapies used in MS, in patients with acute optic neuritis without probable or definite MS and with no prior treatment with corticosteroids. Patients were treated with intravenous methylprednisolone (IVMP) 250 mg four times daily for 3 days, followed by oral prednisone 1 mgkg for 11 days and tapered over 3 days. The results indicated a 2.33-fold, or 57%, reduction in new clinical neurologic attacks that could be interpreted as the development of probable or definite MS, and a 0.36 relative risk of developing definite MS within 2 years compared with the matched placebo group. Only the placebo patients with MRI evidence of multifocal brain demyelination had a sufficient number of clinical events to show that IVMP clearly delayed the development of definite MS. Patients with a normal brain MRI at the time of optic neuritis had such a low 2-year risk of new exacerbations that the benefit of treatment could not be definitely determined. The clinical benefit of IVMP lasted for 2 years, but by year 4 after treatment, the rate of developing definite MS appeared similar in all treatment groups. The LONS also evaluated oral prednisone alone, 1 mgkg for 11 days and tapered over 3 days, and found it to be of no benefit. There are several potential criticisms of the LONS, none of which appear to alter the validity of the reported results. First, the patients were enrolled primarily to investigate the effect of treatment on optic neuritis; the development of definite MS was a secondary assessment. Second, in the original study cohort, patients with probable and definite MS were included. These patients were eliminated from the LONS because they had already reached the end point of the study, the development of probable or definite MS. However, the eliminated patients were equally distributed in all three treatment groups and thus did not create a bias. Third, since follow-up MRI data were not collected, it is not known whether IVMP had an effect on reducing the number of new white matter lesions, including those that were asymptomatic. There is no known mechanism to explain the 2year effect of a brief treatment with corticosteroids. Both corticosteroids and ACTH therapy are well known t o shorten the recovery period after an acute MS attack, but there are no studies that have suggested a long-term (more than 1 year) clinical benefit from any form or dose of cor t icoster~ids .~~~ Because there are few major side effects and fre-

The L3 silicon microvertex detector

Abstract: The design and construction of the silicon strip microvertex detector (SMD) of the L3 experiment at LEP are described. We present the sensors, readout electronics, data acquisition system, mechanical assembly and support, displacement monitoring systems and radiation monitoring system of the recently installed double-sided, double-layered SMD. This detector utilizes novel and sophisticated techniques for its readout.

The heritability of antisocial behavior: A meta-analysis of twin and adoption studies.

Abstract: In this paper, we describe a quantitative summary of 12 twin (n=3795 twin pairs and 3 adoption studies=338 adoptees) published since 1975 which provided 21 estimates of the heritability of antisocial behavior. Medium to large effect sizes were found for genetic influences across studies, with approximately 50% of the variance in measures of antisocial behavior attributable to genetic effects. Although effect sizes did not vary across different definitions of antisocial behavior (criminality, aggression, or antisocial personality), significantly larger estimates of genetic effect were found for severe manifestations of antisocial behavior. The importance of severity was further underscored by the significantly larger effects obtained in studies using clinic-referred samples compared to the effects obtained in studies using volunteer samples. Demographic characteristics of the samples did not influence effect sizes, although studies using more stringent methodology tended to find larger effects. These results must be interpreted in light of the small literature that was suitable for the meta-analysis due to numerous methodological limitations in existing studies.

The Affinity of Foreign Investors for Authoritarian Regimes

Abstract: Military coups in Argentina, Brazil, and Chile in the 1960s and 1970s cast doubt on the liberals' belief that democracy and economic development are mutually reenforcing. Indeed, Guillermo O'Donnel...