Showing papers by "University of New Mexico published in 1998"

Epidemiology of Sarcopenia among the Elderly in New Mexico

Abstract: Muscle mass decreases with age, leading to "sarcopenia," or low relative muscle mass, in elderly people. Sarcopenia is believed to be associated with metabolic, physiologic, and functional impairments and disability. Methods of estimating the prevalence of sarcopenia and its associated risks in elderly populations are lacking. Data from a population-based survey of 883 elderly Hispanic and non-Hispanic white men and women living in New Mexico (the New Mexico Elder Health Survey, 1993-1995) were analyzed to develop a method for estimating the prevalence of sarcopenia. An anthropometric equation for predicting appendicular skeletal muscle mass was developed from a random subsample (n = 199) of participants and was extended to the total sample. Sarcopenia was defined as appendicular skeletal muscle mass (kg)/height2 (m2) being less than two standard deviations below the mean of a young reference group. Prevalences increased from 13-24% in persons under 70 years of age to >50% in persons over 80 years of age, and were slightly greater in Hispanics than in non-Hispanic whites. Sarcopenia was significantly associated with self-reported physical disability in both men and women, independent of ethnicity, age, morbidity, obesity, income, and health behaviors. This study provides some of the first estimates of the extent of the public health problem posed by sarcopenia.

Intrusion detection using sequences of system calls

Abstract: A method is introduced for detecting intrusions at the level of privileged processes. Evidence is given that short sequences of system calls executed by running processes are a good discriminator between normal and abnormal operating characteristics of several common UNIX programs. Normal behavior is collected in two waysc Synthetically, by exercising as many normal modes of usage of a program as possible, and in a live user environment by tracing the actual execution of the program. In the former case several types of intrusive behavior were studieds in the latter case, results were analyzed for false positives.

Cadaver validation of skeletal muscle measurement by magnetic resonance imaging and computerized tomography

Abstract: Magnetic resonance imaging (MRI) and computerized tomography (CT) are promising reference methods for quantifying whole body and regional skeletal muscle mass. Earlier MRI and CT validation studies...

Ionic polymer-metal composites (IPMCs) as biomimetic sensors, actuators and artificial muscles - a review

Abstract: This paper presents an introduction to ionic polymer-metal composites and some mathematical modeling pertaining to them. It further discusses a number of recent findings in connection with ion-exchange polymer-metal composites (IPMCS) as biomimetic sensors and actuators. Strips of these composites can undergo large bending and flapping displacement if an electric field is imposed across their thickness. Thus, in this sense they are large motion actuators. Conversely by bending the composite strip, either quasi-statically or dynamically, a voltage is produced across the thickness of the strip. Thus, they are also large motion sensors. The output voltage can be calibrated for a standard size sensor and correlated to the applied loads or stresses. They can be manufactured and cut in any size and shape. In this paper first the sensing capability of these materials is reported. The preliminary results show the existence of a linear relationship between the output voltage and the imposed displacement for almost all cases. Furthermore, the ability of these IPMCs as large motion actuators and robotic manipulators is presented. Several muscle configurations are constructed to demonstrate the capabilities of these IPMC actuators. This paper further identifies key parameters involving the vibrational and resonance characteristics of sensors and actuators made with IPMCS. When the applied signal frequency varies, so does the displacement up to a critical frequency called the resonant frequency where maximum deformation is observed, beyond which the actuator response is diminished. A data acquisition system was used to measure the parameters involved and record the results in real time basis. Also the load characterizations of the IPMCs were measured and it was shown that these actuators exhibit good force to weight characteristics in the presence of low applied voltages. Finally reported are the cryogenic properties of these muscles for potential utilization in an outer space environment of a few Torrs and temperatures of the order of - 140 degrees Celsius. These muscles are shown to work quite well in such harsh cryogenic environments and thus present a great potential as sensors and actuators that can operate at cryogenic temperatures.

Identifying and Defining the Dimensions of Community Capacity to Provide a Basis for Measurement

Abstract: Although community capacity is a central concern of community development experts, the concept requires clarification. Because of the potential importance of community capacity to health promotion, the Division of Chronic Disease Control and Community Intervention, Centers for Disease Control and Prevention (CDC), convened a symposium in December 1995 with the hope that a consensus might emerge regarding the dimensions that are integral to community capacity. This article describes the dimensions that the symposium participants suggested as central to the construct, including participation and leadership, skills, resources, social and interorganizational networks, sense of community, understanding of community history, community power, community values, and critical reflection. The dimensions are not exhaustive but may serve as a point of departure to extend and refine the construct and to operationalize ways to assess capacity in communities.

Rapid, Low-Technology MIC Determination with Clinical Mycobacterium tuberculosis Isolates by Using the Microplate Alamar Blue Assay

Abstract: A colorimetric, microplate-based Alamar Blue assay (MABA) method was used to determine the MICs of isoniazid (INH), rifampin, streptomycin (SM), and ethambutol (EMB) for 34 Peruvian Mycobacterium tuberculosis isolates (including both pansensitive and multidrug-resistant strains) and the H37Rv strain by using bacterial suspensions prepared directly from solid media. Results for all isolates were available within 8 days. Discordant results were observed on initial tests for 3 of 16 INH-susceptible isolates, 5 of 31 EMB-susceptible isolates, and 2 of 4 SM-resistant isolates (by the BACTEC 460 system). The overall agreements between the MICs obtained by MABA and the results obtained with the BACTEC 460 system were 87.9% for initial results and 93.6% after retesting 12 of 17 samples with discrepant results. Interpretation of MABA endpoints improved with technical experience. The MABA is a simple, rapid, low-cost, appropriate technology which does not require expensive instrumentation and which makes use of a nontoxic, temperature-stable reagent.

Allometric scaling of plant energetics and population density

Abstract: Scaling relationships that describe variation in population density with body size in ecological communities, such as the thinning law in plant ecology1,2,3, can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, which is the same as metabolic rates of animals4,5,6,7. Here we use this relationship to develop a mechanistic model for relationships between density and mass in resource-limited plants. It predicts that average plant size should scale as the −4/3 power of maximum population density, in agreement with empirical evidence and comparable relationships in animals5,6,8, but significantly less than the −3/2 power predicted by geometric models1. Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of population density and other ecological and evolutionary phenomena, including the finding that resource allocation among species in ecosystems is independent of body size5,6,8.

Matrix Metalloproteinases and TIMPs Are Associated With Blood-Brain Barrier Opening After Reperfusion in Rat Brain

Abstract: Background and Purpose —Reperfusion disrupts cerebral capillaries, causing cerebral edema and hemorrhage. Middle cerebral artery occlusion (MCAO) induces the matrix-degrading metalloproteinases, but their role in capillary injury after reperfusion is unknown. Matrix metalloproteinases (MMPs) and tissue inhibitors to metalloproteinases (TIMPs) modulate capillary permeability. Therefore, we measured blood-brain barrier (BBB) permeability, brain water and electrolytes, MMPs, and TIMPs at multiple times after reperfusion. Methods —Adult rats underwent MCAO for 2 hours by the suture method. Brain uptake of 14C-sucrose was measured from 3 hours to 14 days after reperfusion. Levels of MMPs and TIMPs were measured by zymography and reverse zymography, respectively, in contiguous tissues. Other rats had water and electrolytes measured at 3, 24, or 48 hours after reperfusion. Treatment with a synthetic MMP inhibitor, BB-1101, on BBB permeability and cerebral edema was studied. Results —Brain sucrose uptake increased after 3 and 48 hours of reperfusion, with maximal opening at 48 hours and return to normal by 14 days. There was a correlation between the levels of gelatinase A at 3 hours and the sucrose uptake ( P <0.05). Gelatinase A (MMP-2) was maximally increased at 5 days, and TIMP-2 was highest at 5 days. Gelatinase B and TIMP-1 were maximally elevated at 48 hours. The inhibitor of gelatinase B, TIMP-1, was also increased at 48 hours. Treatment with BB-1101 reduced BBB opening at 3 hours and brain edema at 24 hours, but neither was affected at 48 hours. Conclusions —The initial opening at 3 hours correlated with gelatinase A levels and was blocked by a synthetic MMP inhibitor. The delayed opening, which was associated with elevated levels of gelatinase B, failed to respond to the MMP inhibitor, suggesting different mechanisms of injury for the biphasic BBB injury.

Genotyping of 27 Human Papillomavirus Types by Using L1 Consensus PCR Products by a Single-Hybridization, Reverse Line Blot Detection Method

Abstract: Amplification of human papillomavirus (HPV) DNA by L1 consensus primer systems (e.g., MY09/11 or GP5(+)/6(+)) can detect as few as 10 to 100 molecules of HPV targets from a genital sample. However, genotype determination by dot blot hybridization is laborious and requires at least 27 separate hybridizations for substantive HPV-type discrimination. A reverse blot method was developed which employs a biotin-labeled PCR product hybridized to an array of immobilized oligonucleotide probes. By the reverse blot strip analysis, genotype discrimination of multiple HPV types can be accomplished in a single hybridization and wash cycle. Twenty-seven HPV probe mixes, two control probe concentrations, and a single reference line were immobilized to 75- by 6-mm nylon strips. Each individual probe line contained a mixture of two bovine serum albumin-conjugated oligonucleotide probes specific to a unique HPV genotype. The genotype spectrum discriminated on this strip includes the high-risk, or cancer-associated, HPV genotypes 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 55, 56, 58, 59, 68 (ME180), MM4 (W13B), MM7 (P291), and MM9 (P238A) and the low-risk, or non-cancer-associated, genotypes 6, 11, 40, 42, 53, 54, 57, 66, and MM8 (P155). In addition, two concentrations of beta-globin probes allowed for assessment of individual specimen adequacy following amplification. We have evaluated the performance of the strip method relative to that of a previously reported dot blot format (H. M. Bauer et al., p. 132-152, in C. S. Herrington and J. O. D. McGee (ed.), Diagnostic Molecular Pathology: a Practical Approach, (1992), by testing 328 cervical swab samples collected in Digene specimen transport medium (Digene Diagnostics, Silver Spring, Md.). We show excellent agreement between the two detection formats, with 92% concordance for HPV positivity (kappa = 0.78, P < 0.001). Nearly all of the discrepant HPV-positive samples resulted from weak signals and can be attributed to sampling error from specimens with low concentrations (<1 copy/microliter) of HPV DNA. The primary advantage of the strip-based detection system is the ability to rapidly genotype HPVs present in genital samples with high sensitivity and specificity, minimizing the likelihood of misclassification.

Genetic traces of ancient demography

Abstract: Patterns of gene differences among humans contain information about the demographic history of our species. Haploid loci like mitochondrial DNA and the nonrecombining part of the Y chromosome show a pattern indicating expansion from a population of only several thousand during the late middle or early upper Pleistocene. Nuclear short tandem repeat loci also show evidence of this expansion. Both mitochondrial DNA and the Y chromosome coalesce within the last several hundred thousand years, and they cannot provide information about the population before their coalescence. Several nuclear loci are informative about our ancestral population size during nearly the whole Pleistocene. They indicate a small effective size, on the order of 10,000 breeding individuals, throughout this time period. This genetic evidence denies any version of the multiregional model of modern human origins. It implies instead that our ancestors were effectively a separate species for most of the Pleistocene.

Chemotherapy Compared with Autologous or Allogeneic Bone Marrow Transplantation in the Management of Acute Myeloid Leukemia in First Remission

Abstract: Background In young adults with acute myeloid leukemia, intensive chemotherapy during the initial remission improves the long-term outcome, but the role of bone marrow transplantation is uncertain. We compared high-dose cytarabine with autologous or allogeneic marrow transplantation during the first remission of acute myeloid leukemia. Methods Previously untreated adolescents and adults 16 to 55 years of age who had acute myeloid leukemia received standard induction chemotherapy. After complete remission had been achieved, idarubicin (two days) and cytarabine (five days) were administered. Patients with histocompatible siblings were offered allogeneic marrow transplantation, whereas the remaining patients were randomly assigned to receive a single course of high-dose cytarabine or transplantation of autologous marrow treated with perfosfamide (4-hydroperoxycyclophosphamide). Oral busulfan and intravenous cyclophosphamide were used as preparative regimens for both allogeneic and autologous marrow transplan...

Principal-Agent Models: An Expansion?

Abstract: Principal-agent models have been the basis for an extensive set of studies relating bureaucracy to elected officials. Yet despite the outpouring of research, there has been little attempt to test the basic assumptions of the principal-agent model. The model makes two assumptions: that goal conflict exists between principals and agents and that agents have more information than their principals, which results in an information asymmetry between them. But how valid are these assumptions? Can instances be found in which these assumptions do not hold? What happens when we vary these assumptions? In this article, we present both a critique of the traditional principal-agent model and a presentation of a broader theoretical framework for conceptualizing bureaucratic politics. Principal-agent models, derived from such disparate disciplines as law, finance, accounting, and economics, have become the basis for an extensive set of studies relating bureaucracy to elected officials (see Mitnick 1973, 1975, and 1980; Moe 1982, 1984, and 1985; Wood 1988; Wood and Waterman 1991, 1993, and 1994; Scholz and Wei 1986). Such models also have been extended to presidents' decisions to use force (Downs and Rocke 1994) and to the Supreme Court and its relationship to lower courts (Songer, Segal, and Cameron 1994). Despite this outpouring of research, few studies have directly examined the basic terminology and assumptions of the principalagent model. In this article our objectives are to examine principal-agent theory critically, to relax some of its restrictive assumptions, and in the process to present a more general theory of relationships between the bureaucracy and its political environment. Although our critique may be relevant to other uses of the principal-agent model, we limit our assessment to its use as a J-PART 8(1998):2:173-202 theory of bureaucracy. 173/ Journal of Public Administration Research and Theory Principal-Agent Models: An Expansion? THE PRINCIPAL-AGENT MODEL Despite the widespread referencing of the principal-agent model, only in rare instances does a researcher actually discuss the model and how its assumptions fit the problem to be studied. For this reason it is useful to review the model in its various incarnations and to examine its basic assumptions. The principalagent model, as applied in such disciplines as sociology, political science, and public administration, is in essence a theory about contractual relationships between buyers and sellers (see Ross 1973; Pratt and Zeckhauser 1985). As described by Charles Perrow: In its simplest form, agency theory assumes that social life is a series of contracts. Conventionally, one member, the 'buyer' of goods or services is designated the 'principal,' and the other, who provides the goods or service is the 'agent'—hence the term 'agency theory.' The principal-agent relationship is governed by a contract specifying what the agent should do and what the principal must do in return. (1986, 224) A common application in economics is the market for professional services, say between a patient—the principal—and a physician—the agent (Evans 1980). Assuming that both are rational utility maximizers, a patient and a physician are likely to have different goals. The patient would like to be made healthy but pay as little as possible. The physician would be interested in income so, therefore, faces the temptation to provide more medical services than are necessary or to charge a higher price than is warranted. In this exchange, patients are at a disadvantage because they cannot directly evaluate the services provided by the physician. In short, an information asymmetry exists, with an advantage to the physician. Principals seek to manipulate and mold the behavior of agents so that they will act in a manner consistent with the principals' preferences. The contractual arrangement is one tool for accomplishing this goal. The contractual arrangement played an important role in Mitnick's (1973 and 1975) formulation of an institutional or regulatory principal-agent model. Rather than focus on buyers and sellers in an exchange, Mitnick examined the relationship between agents in the regulatory bureaucracy and their political principals (e.g., legislators and interest groups). Mitnick's (1980, 146) framework included \"a typology of agency relationships generated from such dimensions as the level of consent between agent and principal regarding the agent's actions (e.g., whether or not a contract exists, a contract which may be formal or informal), the source of specification of the agent's acts . . . . and the level of discretion possessed by the agent.\" Mitnick noted 174/J-PART, April 1998 Principal-Agent Models: An Expansion? that agents could be motivated by the public interest or by their own narrow self-interest. Since agents enjoy information advantages over their political principals, he added, \"The regulators are thus seen as agents to be policed to adherence to the 'public interest* goals of some principal 'public.'\" But \"such policing is not costless. . . . Principals must pay specification costs to identify acts of the agent that would satisfy the principal's preferences, and policing costs in monitoring and enforcing compliance\" (p. 150). Given the existence of these costs, Mitnick concluded (p. 151), \"The rational principal attempts policing only if he expects a net return . . . We suggest that because of bounded rationality and information costs, not to speak of fundamental problems in valuation, the return to the given public interest criteria may be more difficult to measure and predict than certain obvious indicators wrongly assumed to be correlated with return to that interest.\" In other words, in the principal-agent relationship there is an \"inevitability of control loss\" phenomenon (p. 17). The idea that costs are involved in monitoring an agent, and that principals rationally can decide not to monitor their agents' behavior, explains why the public interest is so often made subservient to private interests in the regulatory arena (one of the main concerns of the regulatory literature). It also raises an important distinction between the economic and the institutional or regulatory principal-agent models. In the institutional model, if a political principal such as the legislature decides that it is not in its rational self-interest to police or monitor its bureaucratic agents, that principal is unlikely to directly bear any cost incurred by the agent's continued shirking. Instead, the bulk of that cost is passed along to the general public, which in a democracy is the legislative branch's political principal. Legislators would pay only a direct cost for their lax oversight of the bureaucracy if the public became aware of it (e.g., if there were a scandal) and sought retribution against legislators at the polls. On the other hand, in the economic model, if the buyer did not adequately monitor the agent's behavior, then the buyer (i.e., the principal) would directly bear the cost, for example, by paying higher fees for services rendered. Likewise, as Mitnick notes, the nature of the contractual arrangement in the regulatory arena can be either formal or informal, whereas formal contracts would be more likely to be adopted in the market-place setting. As these examples demonstrate, important differences emerge once we begin to apply the principal-agent model from market place transactions to the regulatory arena. When political scientists first applied principal-agent theory to bureaucratic settings, further differences emerged from the 175/ J-PART, April 1998 Principal-Agent Models: An Expansion? economic model. In its new formulation, as with buyers and sellers, it is assumed that politicians (principals) and bureaucrats (agents) do not necessarily share similar goals, or to use Mitnick's (1986, 4) terminology, \"have potentially differing preferences. . . .\" If we assume that they are rational utility maximizers (politicians maximizing reelection chances and bureaucrats maximizing budgets), politicians have an interest in policies that benefit their constituents but have no interest in paying excessively for them. Because politicians and political coalitions change over time and bureaucracies develop separate interests through institutionalization and changing external relationships, a potential conflict occurs when the goals and objectives of principals and agents are at odds. Over time politicians may seek to alter established policy toward their preferred objectives, which may or may not be the same as those of the original legislation or political coalition. Bureaucratic interests also diverge from the original policy through time as politicians develop expertise about how the policy should be implemented or gain support from constituencies that favor different approaches. Even if no policy disagreement exists, principal-agent theory suggests that bureaucrats are likely to shirk, to produce outputs at a higher than needed cost, or to produce a level of outputs that is lower than desired. Agency theory posits a dynamic process of interaction between principals and agents, which develops through time. In this process, bureaucrats are assumed to have distinct informational and expertise advantages over politicians. They better understand the policy and the organizational procedures that are required to implement it. They have both the opportunity and the incentive to manipulate politicians and processes for political gain (see Niskanen 1971; Miller and Moe 1983). For some policies, especially those of a technical nature, bureaucracies are more knowledgeable about organizational needs than politicians are, so politicians are reluctant to intervene. Therefore, the key question for agency theory is, How can politicians vested with contemporaneous legitimacy overcome these uncertainties and the bureaucracy's inherent tendency to shirk? (See Wood and Waterman 19

Essential Role of Correlations in Governing Charge Transport in Disordered Organic Materials

Abstract: The transport of photoinjected charges in disordered organic films is often interpreted using a formula based on a Gaussian disorder model (GDM) that neglects spatial correlations due to chargedipole interactions, even though such correlations have recently been shown to explain the universal electric field dependence observed in these systems. Based on extensive computer simulations of a 3D disorder model that includes such correlations, we present a new formula for analyzing experiments that accurately describes transport in these materials. [S0031-9007(98)07626-1]

Continuous self-assembly of organic–inorganic nanocomposite coatings that mimic nacre

Abstract: Nanocomposite materials are widespread in biological systems Perhaps the most studied is the nacre of abalone shell, an orientated coating composed of alternating layers of aragonite (CaCO3) and a biopolymer Its laminated structure simultaneously provides strength, hardness and toughness: containing about 1 vol % polymer, nacre is twice as hard and 1,000 times as tough as its constituent phases1 Such remarkable properties have inspired chemists and materials scientists to develop synthetic, ‘biomimetic’ nanocomposite assemblies2,3,4,5 Nonetheless, the efficient processing of layered organic–inorganic composites remains an elusive goal Here we report a rapid, efficient self-assembly process for preparing nanolaminated coatings that mimic the structure of nacre Beginning with a solution of silica, surfactant and organic monomers, we rely on evaporation during dip-coating to induce the formation of micelles and partitioning of the organic constituents into the micellar interiors6 Subsequent self-assembly of the silica–surfactant–monomer micellar species into lyotropic mesophases7 simultaneously organizes the organic and inorganic precursors into the desired nanolaminated form Polymerization fixes this structure, completing the nanocomposite assembly process This approach may be generalized both to other composite architectures and to other materials combinations

Linear modeling of mRNA expression levels during CNS development and injury.

Abstract: Large-scale gene expression data sets are revolutionizing the field of functional genomics. However, few data analysis techniques fully exploit this entirely new class of data. We present a linear modeling approach that allows one to infer interactions between all the genes included in the data set. The resulting model can be used to generate interesting hypotheses to direct further experiments.

Complete quantum teleportation using nuclear magnetic resonance

Abstract: Quantum-mechanical systems have information processing capabilities1,2 that are not possible with classical devices. One example is quantum teleportation3, in which the quantum state of a system is transported from one location to another without moving through the intervening space. But although partial implementations4,5 of quantum teleportation over macroscopic distances have been achieved using optical systems, the final stage of the teleportation procedure — which allows the complete recovery of the original state — was omitted. Here we report an experimental implementation of full quantum teleportation over interatomic distances using liquid-state nuclear magnetic resonance. We achieve teleportation of the quantum state of a carbon nucleus to a hydrogen nucleus in molecules of trichloroethylene, by exploiting natural phase decoherence of the carbon nuclei. Such a teleportation scheme may be used as a subroutine in larger quantum computations, or for quantum communication.

Aerosol Processing of Materials

Abstract: Recent advances in aerosol generation of materials are reviewed Gas-to-particle and spray processes (spray pyrolysis) for powder generation and various routes for film generation are discussed from the experimental and theoretical perspectives The range of materials generated by these routes has increased in recent years to include fullerenes and ceramic superconductors Many metals and various oxide and nonoxide ceramics have also been added to the list of materials generated by gas-phase routes Established aerosol routes such as vapor condensation have found widespread applications for generation of nanophase materials The formation of quantum dots via aerosol approaches has also been demonstrated The theoretical understanding of gas-to-particle conversion routes has advanced to include the finite rate of particle fusion or sintering occurring after collisions of particles The modeling of spray pyrolysis systems has provided insight into the control of particle morphology and reactor design In th

Extended use of glatiramer acetate (Copaxone) is well tolerated and maintains its clinical effect on multiple sclerosis relapse rate and degree of disability

Abstract: When 251 relapsing-remitting patients with multiple sclerosis were randomized to receive daily subcutaneous injections of glatiramer acetate, previously called copolymer 1 (Copaxone; n = 125) or placebo (n = 126) for 24 months, there were no laboratory abnormalities associated with glatiramer acetate treatment and it was well tolerated with few side effects. Patients receiving glatiramer acetate had significantly fewer relapses and were more likely to be neurologically improved, whereas those receiving placebo were more likely to worsen. This study was extended for 1 to 11 months (mean of 5.2 months for the glatiramer acetate group and 5.9 months for the placebo group). The blinding and study conditions used during the core 24-month study were unchanged throughout the extension. The results of this extension study confirm the excellent tolerance and safety profile of glatiramer acetate for injection. The clinical benefit of glatiramer acetate for both the relapse rate and for neurologic disability was sustained at the end of the extension trial.

Cortical networks underlying mechanisms of time perception

Abstract: Precise timing of sensory information from multiple sensory streams is essential for many aspects of human perception and action. Animal and human research implicates the basal ganglia and cerebellar systems in timekeeping operations, but investigations into the role of the cerebral cortex have been limited. Individuals with focal left (LHD) or right hemisphere (RHD) lesions and control subjects performed two time perception tasks (duration perception, wherein the standard tone pair interval was 300 or 600 msec) and a frequency perception task, which controlled for deficits in time-independent processes shared by both tasks. When frequency perception deficits were controlled, only patients with RHD showed time perception deficits. Time perception competency was correlated with an independent test of switching nonspatial attention in the RHD but not the LHD patients, despite attention deficits in both groups. Lesion overlays of patients with RHD and impaired timing showed that 100% of the patients with anterior damage had lesions in premotor and prefrontal cortex (Brodmann areas 6, 8, 9, and 46), and 100% with posterior damage had lesions in the inferior parietal cortex. All LHD patients with normal timing had damage in these same regions, whereas few, if any, RHD patients with normal timing had similar lesion distributions. These results implicate a right hemisphere prefrontal-inferior parietal network in timing. Time-dependent attention and working memory functions may contribute to temporal perception deficits observed after damage to this network.

Results on ν μ → ν e Neutrino Oscillations from the LSND Experiment

Abstract: A search for ${\ensuremath{ u}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{ u}}_{e}$ oscillations has been conducted with the LSND apparatus using ${\ensuremath{ u}}_{\ensuremath{\mu}}$ from ${\ensuremath{\pi}}^{+}$ decay in flight. Two analyses observe a total of 40 beam-on high-energy (60--200 MeV) electron events consistent with the ${\ensuremath{ u}}_{e}\mathrm{C}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}X$ inclusive reaction. This number is significantly above the $21.9\ifmmode\pm\else\textpm\fi{}2.1$ events expected from the ${\ensuremath{ u}}_{e}$ contamination in the beam and the beam-off background. If interpreted as an oscillation signal, the observed oscillation probability of $(2.6\ifmmode\pm\else\textpm\fi{}1.0\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ is consistent with the previously reported ${\overline{\ensuremath{ u}}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\overline{\ensuremath{ u}}}_{e}$ oscillation evidence from LSND.

Anhedonia, Positive and Negative Affect, and Social Functioning in Schizophrenia

Abstract: This study examines the relationship between anhedonia and the trait dimensions of positive affect (PA) and negative affect (NA) in schizophrenia. The relationship between poor social functioning in schizophrenia and these individual differences in affectivity is also examined. Schizophrenia outpatients (n = 37) and normal controls (n = 15) were assessed at a baseline evaluation and again approximately 90 days later. Consistent with the hypothesized decrease in hedonic capacity in schizophrenia, patients reported significantly greater physical and social anhedonia and less PA than controls. However, the schizophrenia group also reported significantly greater NA and social anxiety than did controls. In support of the dispositional view of these individual differences in affectivity, trait measures demonstrated test-retest reliability, and group differences between the schizophrenia group and controls were stable over the 90-day followup period. Within the schizophrenia group, physical and social anhedonia were comparably negatively correlated with trait PA; however, social but not physical anhedonia was significantly positively correlated with NA and social anxiety. Poor social functioning in the schizophrenia group was associated with greater physical and social anhedonia and greater NA and social anxiety. Alternatively, greater trait PA was related to better social functioning. These findings indicate that schizophrenia is characterized by both low PA and elevated NA and that these affective characteristics are a stable feature of the illness. The results also suggest important links between affect and social functioning in schizophrenia.

Menstrual cycle variation in women's preferences for the scent of symmetrical men.

Abstract: Evidence suggests that female sexual preferences change across the menstrual cycle. Women’s extra-pair copulations tend to occur in their most fertile period, whereas their intra-pair copulations tend to be more evenly spread out across the cycle.This pattern is consistent with women preferentially seeking men who evidence phenotypic markers of genetic bene¢ts just before and during ovulation.This study examined whether women’s olfactory preferences for men’s scent would tend to favour the scent of more symmetrical men, most notably during the women’s fertile period. College women sniied and rated the attractiveness of the scent of 41T-shirts worn over a period of two nights by diierent men. Results indicated that normally cycling (non-pill using) women near the peak fertility of their cycle tendedto prefer the scent of shirts worn by symmetrical men. Normally ovulating women at low fertility within their cycle, and women using a contraceptive pill, showed no signi¢cant preference for either symmetrical or asymmetrical men’s scent. A separate analysis revealed that, within the set of normally cycling women, individual women’s preference for symmetry correlated with their probability of conception, given the actuarial value associated with the day of the cycle they reported at the time they smelled the shirts. Potential sexual selection processes and proximate mechanisms accounting for these ¢ndings are discussed.

Quality Health Outcomes Model

Abstract: Purpose: Donabedian's 1966 framework of structure, process, and outcome has guided three decades of study in the United States of the elements needed to evaluate and compare medical care quality. Donabedian's perspective was essentially linear, assuming that structures affect processes, which in turn affect outcomes. Patient characteristics are sometimes considered as mediating outcomes and clinical interventions are considered to be processes. A model is presented in the following article that relates multiple factors affecting quality of care to desired outcomes. It extends previous models by positing dynamic relationships with indicators that not only act upon, but reciprocally affect the various components. Scope and Sources: The proposed model was derived from a synthesis of the authors' experience in quality of care practice and research, as well as selected previous theories. Conclusions: The quality health outcomes model is sufficiently broad (a) to guide development of databases for quality improvement and outcomes management, (b) to suggest key variables in clinical intervention research, and (c) to provide a framework for outcomes research and outcomes management that compares not only treatment options, but organizational or system level interventions. The model also has several policy implications.

Researching the spiritual dimensions of alcohol and other drug problems

Abstract: Although religions have been far from silent on the use of psychoactive drugs, and spirituality has long been emphasized as an important factor in recovery from addiction, surprisingly little research has explored the relationships between these two phenomena. Current findings indicate that spiritual/religious involvement may be an important protective factor against alcohol/drug abuse. Individuals currently suffering from these problems are found to have a low level of religious involvement, and spiritual (re)engagement appears to be correlated with recovery. Reasons are explored for the lack of studies testing spiritual hypotheses, and promising avenues for future research are discussed. Comprehensive addictions research should include not only biomedical, psychological and socio-cultural factors but spiritual aspects of the individual as well.

Information transmission through a noisy quantum channel

Abstract: Noisy quantum channels may be used in many information-carrying applications. We show that different applications may result in different channel capacities. Upper bounds on several of these capacities are proved. These bounds are based on the coherent information, which plays a role in quantum information theory analogous to that played by the mutual information in classical information theory. Many new properties of the coherent information and entanglement fidelity are proved. Two nonclassical features of the coherent information are demonstrated: the failure of subadditivity, and the failure of the pipelining inequality. Both properties arise as a consequence of quantum entanglement, and give quantum information new features not found in classical information theory. The problem of a noisy quantum channel with a classical observer measuring the environment is introduced, and bounds on the corresponding channel capacity proved. These bounds are always greater than for the unobserved channel. We conclude with a summary of open problems.

Rab11 is required for trans-golgi network-to-plasma membrane transport and a preferential target for GDP dissociation inhibitor.

Abstract: The rab11 GTPase has been localized to both the Golgi and recycling endosomes; however, its Golgi-associated function has remained obscure. In this study, rab11 function in exocytic transport was a...

Opposing time trends of peptic ulcer and reflux disease

Abstract: Background —Gastritis associated hypochlorhydria may be protective against gastro-oesophageal reflux disease. It was hypothesised that the historic decline in Helicobacter pylori infection resulted in a decline in peptic ulcer and a concomitant rise in reflux disease. Aims —To study the time trends of peptic ulcer and reflux disease. Methods —Hospitalisation rates were analysed using the computerised database of the US Department of Veterans Affairs from 1970 until 1995. Death rates were calculated from the Vital Statistics of the United States. Results —From 1970 to 1995, hospitalisation rates for gastric and duodenal ulcer, as well as gastric cancer fell, while the hospitalisation rates for gastro-oesophageal reflux disease and those for oesophageal adenocarcinoma rose significantly. Similar time trends were observed with respect to the death rates. There were notable ethnic differences. White subjects incurred higher rates of reflux disease and oesophageal adenocarcinoma and lower rates of gastric ulcer or cancer compared with non-whites. Conclusions —The ethnic variations and the opposing time trends of gastroduodenal versus oesophageal disease are consistent with the hypothesis that the declining infection rates of H pylori in the general population have led to a rise in the occurrence of gastro-oesophageal reflux disease and associated oesophageal adenocarcinoma.