Sample records for limited human studies

  1. Int. J. Human-Computer Studies 65 (2007) 192205 Making adaptive cruise control (ACC) limits visible

    E-print Network

    Lee, John D.

    2007-01-01

    Int. J. Human-Computer Studies 65 (2007) 192­205 Making adaptive cruise control (ACC) limits Previous studies have shown adaptive cruise control (ACC) can compromise driving safety when drivers do with adaptive cruise control (ACC). This technology is sub- stantially more complex than conventional cruise

  2. Limits of resolution of genetic linkage studies: Implications for the positional cloning of human disease genes

    SciTech Connect

    Boehnke, M. (Univ. of Michigan, Ann Arbor, MI (United States))

    1994-08-01

    Positional cloning studies to identify disease genes are being carried out for many human genetic diseases. Such studies often include a genome-scan linkage analysis to identify the rough chromosomal location of a disease gene, fine structure genetic mapping to define and narrow the chromosomal interval in which the disease gene may be located, and physical mapping and gene identification in the genetically defined interval to clone the disease gene. During the planning of a positional cloning study, it is important to know that, if linkage is found, the genetic interval identified is likely to be sufficiently narrow to be dissected efficiently by methods of physical mapping and gene identification. Thus, one wishes to know the limits of resolution of a genetic linkage study. In this paper, the author determines for Mendelian diseases the distributions and moments of three measures of linkage resolution: (1) in a set of N chromosomes, the distance between the nearest crossovers that flank a disease locus, (2) the distance between the nearest genetic markers that flank the pair of flanking crossovers after a genome scan, and (3) the distance between the nearest flanking markers after additional randomly placed markers are generated and typed in an identified interval. These results provide explicit sample-size guidelines for future positional cloning studies of Mendelian diseases and make possible a more objective evaluation of whether a proposed positional cloning study is likely to be successful. The author also briefly discusses the more difficult problem of linkage resolution for complex genetic diseases. 14 refs., 1 fig., 6 tabs.

  3. A Probabilistic Approach for Deriving Acceptable Human Intake Limits and Human Health Risks from Toxicological Studies: General Framework

    Microsoft Academic Search

    W. Slob; M. N. Pieters

    1998-01-01

    The use of uncertainty factors in the standard method for deriving acceptable intake or exposure limits for humans, such as the Reference Dose (RfD), may be viewed as a conservative method of taking various uncertainties into account. As an obvious alternative, the use of uncertainty distributions instead of uncertainty factors is gaining attention. This paper presents a comprehensive discussion of

  4. Archive: APS: Studying the Human Physiological Limits of Exploring Mars, May 13, 2009

    NSDL National Science Digital Library

    1900-01-01

    Dr. Jim Pawelczyk, Associate Professor of Physiology, Kinesiology and Medicine at Pennsylvania State University has had extensive experience as an astronaut and researcher on the effects of microgravity on the human body. Missions to Mars would require humans to travel well beyond the current record of 15 months by a Russian astronaut, and doubling that length to nearly 30 months. Factors such as the environment, bone repair and growth, radiation, psychological stamina, and other influences play a critical role towards achieving this goal. Data from previous missions such as the International Space Station and Skylab have helped in determining how to address these challenges, but Pawelczyk points out the need to inspire today's students to realize the solutions and possibilities of such travel since they will be our astronauts, engineers, and scientists of tomorrow. For more information about this web seminar, its presenter(s), read what participants said about it, and to see and download its PowerPoint slides go here .

  5. Teleoperator Human Factors Study

    NASA Technical Reports Server (NTRS)

    1986-01-01

    An investigation of the spectrum of space teleoperation activities likely in the 1985 to 1995 decade focused on the resolution of critical human engineering issues and characterization of the technology effect on performance of remote human operators. The study began with the identification and documentation of a set of representative reference teleoperator tasks. For each task, technology, development, and design options, issues, and alternatives that bear on human operator performance were defined and categorized. A literature survey identified existing studies of man/machine issues. For each teleoperations category, an assessment was made of the state of knowledge on a scale from adequate to void. The tests, experiments, and analyses necessary to provide the missing elements of knowledge were then defined. A limited set of tests were actually performed, including operator selection, baseline task definition, control mode study, lighting study, camera study, and preliminary time delay study.

  6. Phosphorus: a limiting nutrient for humanity?

    PubMed

    Elser, James J

    2012-12-01

    Phosphorus is a chemical element that is essential to life because of its role in numerous key molecules, including DNA and RNA; indeed, organisms require large amounts of P to grow rapidly. However, the supply of P from the environment is often limiting to production, including to crops. Thus, large amounts of P are mined annually to produce fertilizer that is applied in support of the 'Green Revolution.' However, much of this fertilizer eventually ends up in rivers, lakes and oceans where it causes costly eutrophication. Furthermore, given increasing human population, expanding meat consumption, and proliferating bioenergy pressures, concerns have recently been raised about the long-term geological, economic, and geopolitical viability of mined P for fertilizer production. Together, these issues highlight the non-sustainable nature of current human P use. To achieve P sustainability, farms need to become more efficient in how they use P while society as a whole must develop technologies and practices to recycle P from the food chain. Such large-scale changes will probably require a radical restructuring of the entire food system, highlighting the need for prompt but sustained action. PMID:22465489

  7. Studies That Observe Humans

    MedlinePLUS

    ... Topic Human testing: Clinical trials Studies that observe humans A study that simply looks at people is ... in the past without counting on a person’s memory. And there’s no way to find out what ...

  8. Limiting Reactants: Industrial Case Study

    NSDL National Science Digital Library

    Dave Blackburn

    An exercise in which students apply limiting reactants, mass ratios and percent yields to suggest an optimum industrial process. Cost figures are provided but students are told to come up with, and defend, their own criteria for their recommendation.

  9. Approaching the Limit of Predictability in Human Mobility

    PubMed Central

    Lu, Xin; Wetter, Erik; Bharti, Nita; Tatem, Andrew J.; Bengtsson, Linus

    2013-01-01

    In this study we analyze the travel patterns of 500,000 individuals in Cote d'Ivoire using mobile phone call data records. By measuring the uncertainties of movements using entropy, considering both the frequencies and temporal correlations of individual trajectories, we find that the theoretical maximum predictability is as high as 88%. To verify whether such a theoretical limit can be approached, we implement a series of Markov chain (MC) based models to predict the actual locations visited by each user. Results show that MC models can produce a prediction accuracy of 87% for stationary trajectories and 95% for non-stationary trajectories. Our findings indicate that human mobility is highly dependent on historical behaviors, and that the maximum predictability is not only a fundamental theoretical limit for potential predictive power, but also an approachable target for actual prediction accuracy. PMID:24113276

  10. Teleoperator human factors study

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The progress made on the Teleoperator Human Factors Study program is summarized. Technical and programmatic problems that were encountered were discussed along with planned activities. The report contains four sections: Work Performed, Future Work, Problems Encountered, and Cost Information

  11. Teleoperator human factors study

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The progress made on the Teleoperator Human Factors Study program is summarized. Technical and programmatic problems that were encountered are discussed along with planned activity. Work performed, future work, problems encountered, and cost information comprise the topics addressed herein.

  12. Human factor and computational intelligence limitations in resilient control systems

    E-print Network

    Wilamowski, Bogdan Maciej

    . Humans are also the weakest links in communication control processes. Please notice that an airplane may fly smoothly only when it is on autopilot. The manual control of the airplane is used only whenHuman factor and computational intelligence limitations in resilient control systems Bogdan M

  13. Hierarchical implicit surface joint limits for human body tracking

    Microsoft Academic Search

    L. Herda; Raquel Urtasun; P. Fua

    2005-01-01

    To increase the reliability of existing human motion tracking algorithms, we propose a method for imposing limits on the underlying hierarchical joint structures in a way that is true to life. Unlike most existing approaches, we explicitly represent dependencies between the various degrees of freedom and derive these limits from actual experimental data. To this end, we use quaternions to

  14. Studies on the dynamics of limited filaments

    E-print Network

    Bonde, Jeffrey David

    2010-01-01

    A study on the dynamics of filaments in the presence of a diagnostic, conductive limiter is presented. Plasma filaments are coherent structures present in many fusion devices and transport a significant amount of particles ...

  15. Closed Ecological Systems (CES) Functional Stability Limits and Human Control

    NASA Astrophysics Data System (ADS)

    Rygalov, V.; Nelson, M.; de Silva, S.

    newline Global planet The Earth Closed System stability of functioning is based on principle of statistical regulations and provided by enormous planetary buffer capacities atmosphere water soil time and sources of energy natural and fossilized All current deviations caused by human activity in Earth Biosphere are being easily eliminated and absorbed by these planetary buffers Man-made Closed Ecosystems function at the limits of their natural stability due to insufficient buffer capacities we have to minimize system size and physical mass to get it into the space principle of statistical regulations becomes insufficient for stability maintenance and needs to be replaced by other control approaches It had been indicated qualitatively earlier Gitelson et al 1975 that Human Factor HF purposeful control can increase these systems stability levels if applies algorithms compatible to man-made CES natural functioning mechanisms Theoretical analysis is being done on the basis of the results obtained in different experiments for closed ecosystems of different scale Biosphere of the Earth Biosphere -- 2 BIOS -- 3 etc It is shown that certain limits of functional stability exist for each specific system in terms of average cycle rate and fluctuations range These limits are determined primarily by newline - system s natural buffer capacities newline - rate of slowest material cycle in the system - natural structure of the chemical elements cycles - HF human consumption conversion material load on to the cycles

  16. Artificial Closed Ecosystems Stability and Human Control Limitations

    NASA Astrophysics Data System (ADS)

    Rygalov, Vadim; Casler, James G.; Holubnyak, Yevhen

    The stability of the complex ecological system of the Earth accommodates statistical variation through the existence of extensive planetary buffers in atmosphere, water, soil, time, and energy sources. Variation in the Earth biosphere caused by either natural mechanisms or human activity is readily absorbed by these systemic, planetary buffers. Artificial Closed Ecological Systems (CES) for long-term life support in space are marginally stable to unstable due to insufficient buffer capacities stemming from significantly smaller system size and mass in space adaptations. Manual control can improve stability of such systems if CES system-specific control algorithms are applied. This paper introduces a conceptual model for CES stability and suggests system characteristics to maintain this stability for extended durations. Numerical estimates for CES of various scales and configurations, e.g., Biosphere of the Earth, Biosphere 2 (USA), BIOS 3 (Russia), Closed Ecological Experimental Facility (CEEF, Japan), etc., show that stability limits exist and differ for each specific system. These limits are determined primarily by: 1. The slowest circulating (so called limiting) material cycle in the system; 2. The buffer capacities for this cycle (cycle reservoirs); 3. The natural structure and intensity (rate) of the material turnover. Humans as an element of the system can exert control in a variety of manners. Human control can improve stability significantly but the controller must have a comprehensive understanding of closed material cycles structural (network related) and dynamical (turnover time related) characteristics. This understanding requires better models of the Earth biosphere mechanisms, as well as greater extensive experimentation with these models.

  17. HUMAN DEVELOPMENT Program of Study

    E-print Network

    Thomas, Andrew

    HUMAN DEVELOPMENT Program of Study Financial Aid Students Applying Correspondence The graduate program in Human Development is designed to provide advanced training, with special emphasis on child development and family relations. This program is designed for those interested in working in the human

  18. Human Paraoxonase 1 as a Pharmacologic Agent: Limitations and Perspectives

    PubMed Central

    Bajaj, Priyanka; Tripathy, Rajan K.; Aggarwal, Geetika; Pande, Abhay H.

    2014-01-01

    Human PON1 (h-PON1) is a multifaceted enzyme and can hydrolyze (and inactivate) a wide range of substrates. The enzyme shows anti-inflammatory, antioxidative, antiatherogenic, ant-diabetic, antimicrobial, and organophosphate (OP)-detoxifying properties. However, there are certain limitations regarding large-scale production and use of h-PON1 as a therapeutic candidate. These include difficulties in producing recombinant h-PON1 (rh-PON1) using microbial expression system, low hydrolytic activity of wild-type h-PON1 towards certain substrates, and low storage stability of the purified enzyme. This review summarizes the work done in our laboratory to address these limitations. Our results show that (a) optimized polynucleotide sequence encoding rh-PON1 can express the protein in an active form in E. coli and can be used to generate variant of the enzyme having enhanced hydrolytic activity, (b) in vitro refolding of rh-PON1 enzyme can dramatically increase the yield of an active enzyme, (c) common excipients can be used to stabilize purified rh-PON1 enzyme when stored under different storage conditions, and (d) variants of rh-PON1 enzyme impart significant protection against OP-poisoning in human blood (ex vivo) and mouse (in vivo) model of OP-poisoning. The rh-PON1 variants and their process of production discussed here will help to develop h-PON1 as a therapeutic candidate. PMID:25386619

  19. Density limit studies on DIII-D

    SciTech Connect

    Maingi, R. [Oak Ridge National Lab., TN (United States); Mahdavi, M.A.; Petrie, T.W. [General Atomics, San Diego, CA (United States)] [and others

    1998-08-01

    The authors have studied the processes limiting plasma density and successfully achieved discharges with density {approximately}50% above the empirical Greenwald density limit with H-mode confinement. This was accomplished by density profile control, enabled through pellet injection and divertor pumping. By examining carefully the criterion for MARFE formation, the authors have derived an edge density limit with scaling very similar to Greenwald scaling. Finally, they have looked in detail at the first and most common density limit process in DIII-D, total divertor detachment, and found that the local upstream separatrix density (n{sub e}{sup sep,det}) at detachment onset (partial detachment) increases with the scrape-off layer heating power, P{sub heat}, i.e., n{sub e}{sup sep,det} {approximately} P{sub heat}{sup 0.76}. This is in marked contrast to the line-average density at detachment which is insensitive to the heating power. The data are in reasonable agreement with the Borass model, which predicted that the upstream density at detachment would increase as P{sub heat}{sup 0.7}.

  20. On Editing and Human Studies

    Microsoft Academic Search

    Frances Chaput Waksler

    2002-01-01

    It is both an honor and a pleasure to participate in celebrating 25 years of Human Studies by serving as guest editor of this Special Issue. In assembling this volume I have been able to experience ab initio the many facets of Human Studies that make it such an important journal – its interdisciplinary character, high intellectual standards, commitment to

  1. Perspectives: Why Study Human Genetics?

    ERIC Educational Resources Information Center

    Childs, Barton

    1983-01-01

    Reasons for studying human genetics are discussed. These include philosophical reasons, reasons of health, and social reasons. While content, interpretation, and emphasis of human genetics study will vary depending upon schools, teachers, and developmental stages of students, it is suggested that teachers address these three domains. (Author/JN)

  2. Limited communication capacity unveils strategies for human interaction

    NASA Astrophysics Data System (ADS)

    Miritello, Giovanna; Lara, Rubén; Cebrian, Manuel; Moro, Esteban

    2013-06-01

    Connectivity is the key process that characterizes the structural and functional properties of social networks. However, the bursty activity of dyadic interactions may hinder the discrimination of inactive ties from large interevent times in active ones. We develop a principled method to detect tie de-activation and apply it to a large longitudinal, cross-sectional communication dataset (~19 months, ~20 million people). Contrary to the perception of ever-growing connectivity, we observe that individuals exhibit a finite communication capacity, which limits the number of ties they can maintain active in time. On average men display higher capacity than women, and this capacity decreases for both genders over their lifespan. Separating communication capacity from activity reveals a diverse range of tie activation strategies, from stable to exploratory. This allows us to draw novel relationships between individual strategies for human interaction and the evolution of social networks at global scale.

  3. Tolerance limit of human head-neck region to high speed windblast.

    PubMed

    Zhang, Y; Wu, G

    1997-02-01

    To provide parameters for designers of open type escape system in an aircraft, aerodynamic and biomechanical characteristics of human head-neck region was studied and analysed. The results show that tolerance limit of human head-neck region are 2.452 kN, 1.358 kN and 0.169 kN to aerodynamic drag, aerodynamic lift, and aerodynamic side force respectively during high speed windblast. Meanwhile the curve of tolerance limit to high speed windblast is given. Regardless of crewman posture during ejection, human head-neck region is free from windblast injury unless the aerodynamic force exerted on the head-neck region is within the above-mentioned value. PMID:11539894

  4. Long-term vegetation changes in the northern Scandinavian forest limit: a human impact-climate synergy?

    Microsoft Academic Search

    Hanna Karlsson; Greger Hörnberg; Gina Hannon; Eva-Maria Nordström

    2007-01-01

    A palaeoecological study was performed in the northern Scandinavian mountain range in Sweden. The aim was to study vegetation changes and shifts in forest limit altitudes during the last 5000 years in a tree-less archaeological site (Adamvalta) situated below the regional forest limit, and in a forested reference area with similar geological features but without archaeological evidence of human presence

  5. 237Poverty and Human Capability Studies Poverty and Human

    E-print Network

    Dresden, Gregory

    237Poverty and Human Capability Studies Poverty and Human CaPability StudieS (Pov) Core Fa and Human Capability offers a cur- ricular and cocurricular program of study that enriches any major to establish a decent minimum of human development for all people. Students complet- ing designated

  6. Toward a theology of limits. Seen in the right way, limits can enlarge the range of human possibility.

    PubMed

    Smith, P

    1999-01-01

    Many in healthcare bemoan the limits-on, for example, budgets, patient autonomy, and life-prolonging interventions--of the 1990s. But limits can enhance, as well as constrict, human possibilities. Genesis reminds us that being limited is part of being human. Without limits, we would not need to become responsible. We would not need compassion, reconciliation, healing, prudence, risk, or trust. Hopes and dreams would be irrelevant. We would be paralyzed by indifference. The Bible also tells us that God is self-limiting. The New Testament describes God's self-limiting Incarnation as Jesus of Nazareth. The theology of Incarnation says that God works not in spite of human structures, experiences, and limits, but through them. The doctrine of the Trinity shows that God's own identity consists in relationship. It is from the perspective of community that one sees modern humanity's greatest ethical challenges. If we of the Catholic ministry are to be at the healthcare table, we must be willing to compromise. And we must be at the table if our values of inherent human dignity, social justice, and care for society's outcasts are to have a voice. PMID:10623175

  7. Cardiovascular Deconditioning in Humans: Human Studies Core

    NASA Technical Reports Server (NTRS)

    Williams, Gordon

    1999-01-01

    Major cardiovascular problems, secondary to cardiovascular deconditioning, may occur on extended space missions. While it is generally assumed that the microgravity state is the primary cause of cardiovascular deconditioning, sleep deprivation and disruption of diurnal rhythms may also play an important role. Factors that could be modified by either or both of these perturbations include: autonomic function and short-term cardiovascular reflexes, vasoreactivity, circadian rhythm of cardiovascular hormones (specifically the renin-angiotensin system) and renal sodium handling and hormonal influences on that process, venous compliance, cardiac mass, and cardiac conduction processes. The purpose of the Human Studies Core is to provide the infrastructure to conduct human experiments which will allow for the assessment of the likely role of such factors in the space travel associated cardiovascular deconditioning process and to develop appropriate countermeasures. The Core takes advantage of a newly-created Intensive Physiologic Monitoring (IPM) Unit at the Brigham and Women's Hospital, Boston, MA, to perform these studies. The Core includes two general experimental protocols. The first protocol involves a head down tilt bed-rest study to simulate microgravity. The second protocol includes the addition of a disruption of circadian rhythms to the simulated microgravity environment. Before and after each of these environmental manipulations, the subjects will undergo acute stressors simulating changes in volume and/or stress, which could occur in space and on return to Earth. The subjects are maintained in a rigidly controlled environment with fixed light/dark cycles, activity pattern, and dietary intake of nutrients, fluids, ions and calories.

  8. Physiology for High School - Human Physiological Limits to Exploring Mars

    NSDL National Science Digital Library

    PhD James A Pawelczyk (Pennsylvania State University)

    2008-04-05

    The keynote presentation from EB 2008's Physiology for Life Science High School Teachers and Students Workshop. This powerpoint presentation discusses the possibility of human exploration on Mars, specifically, how space flight and life on mars would effect human physiology.

  9. Humanizing Home Study.

    ERIC Educational Resources Information Center

    Hass, Glen; Fleury, Donna

    The use of correspondence or home study courses for noncredit is a recent development in the field of adult education. The challenge facing the extension worker is to be able to develop and deliver the type of program that not only meets the learning (content) need of the participant but that also meets the learning situation. Unfortunately, the…

  10. Flight Controllability Limits and Related Human Transfer Functions as Determined from Simulator and Flight Tests

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr.; Day, Richard E.

    1961-01-01

    A simulator study and flight tests were performed to determine the levels of static stability and damping necessary to enable a pilot to control the longitudinal and lateral-directional dynamics of a vehicle for short periods of time. Although a basic set of aerodynamic characteristics was used, the study was conducted so that the results would be applicable to a wide range of flight conditions and configurations. Novel piloting techniques were found which enabled the pilot to control the vehicle at conditions that were otherwise uncontrollable. The influence of several critical factors in altering the controllability limits was also investigated. Several human transfer functions were used which gave fairly good representations of the controllability limits determined experimentally for the short-period longitudinal, directional, and lateral modes. A transfer function with approximately the same gain and phase angle as the pilot at the controlling frequencies along the controllability limits was also derived.

  11. Limited interaction between translation and visual motion aftereffects in humans

    PubMed Central

    2012-01-01

    After exposure to a moving sensory stimulus, subsequent perception is often biased in the opposite direction. This phenomenon, known as an aftereffect, has been extensively studied for optic flow stimuli where it is known as the visual motion aftereffect (MAE). Such visual motion can also generate the sensation of self-motion or vection. It has recently been demonstrated that fore-aft translation in darkness also produces an aftereffect. The current study examines the interaction between visual MAE and vestibular translation aftereffects. Human subjects participated in a two-interval experiment in which the first interval (adapter) was visual, translation, or both combined congruently or in conflict. Subjects identified the direction of the second (test) interval of either visual or translation using a forced-choice technique. The translation adapter had no influence on visual test stimulus perception, and the visual adapter did not influence vestibular test stimulus perception in any subjects. However, congruent visual and translation induced a significantly larger perceptual bias on the translation test stimulus than was observed for a translation only adapter. The congruent adapter caused the MAE to be diminished relative to a visual only adapter. Conflicting visual and vestibular adapters produced an aftereffect similar to that seen when the single adapting stimulus was the same modality as the test stimulus. These results suggest that unlike visual and translation stimuli whose combined influence on perception can be predicted based on the effects of each stimulus individually, the effects of combined visual and translation stimuli on aftereffects cannot be predicted from the influences of each stimulus individually. PMID:23064848

  12. Ionic mechanisms limiting cardiac repolarization reserve in humans compared to dogs

    PubMed Central

    Jost, Norbert; Virág, László; Comtois, Philippe; Ördög, Balázs; Szuts, Viktória; Seprényi, György; Bitay, Miklós; Kohajda, Zsófia; Koncz, István; Nagy, Norbert; Szél, Tamás; Magyar, János; Kovács, Mária; Puskás, László G; Lengyel, Csaba; Wettwer, Erich; Ravens, Ursula; Nánási, Péter P; Papp, Julius Gy; Varró, András; Nattel, Stanley

    2013-01-01

    The species-specific determinants of repolarization are poorly understood. This study compared the contribution of various currents to cardiac repolarization in canine and human ventricle. Conventional microelectrode, whole-cell patch-clamp, molecular biological and mathematical modelling techniques were used. Selective IKr block (50–100 nmol l?1 dofetilide) lengthened AP duration at 90% of repolarization (APD90) >3-fold more in human than dog, suggesting smaller repolarization reserve in humans. Selective IK1 block (10 ?mol l?1 BaCl2) and IKs block (1 ?mol l?1 HMR-1556) increased APD90 more in canine than human right ventricular papillary muscle. Ion current measurements in isolated cardiomyocytes showed that IK1 and IKs densities were 3- and 4.5-fold larger in dogs than humans, respectively. IKr density and kinetics were similar in human versus dog. ICa and Ito were respectively ?30% larger and ?29% smaller in human, and Na+–Ca2+ exchange current was comparable. Cardiac mRNA levels for the main IK1 ion channel subunit Kir2.1 and the IKs accessory subunit minK were significantly lower, but mRNA expression of ERG and KvLQT1 (IKr and IKs?-subunits) were not significantly different, in human versus dog. Immunostaining suggested lower Kir2.1 and minK, and higher KvLQT1 protein expression in human versus canine cardiomyocytes. IK1 and IKs inhibition increased the APD-prolonging effect of IKr block more in dog (by 56% and 49%, respectively) than human (34 and 16%), indicating that both currents contribute to increased repolarization reserve in the dog. A mathematical model incorporating observed human–canine ion current differences confirmed the role of IK1 and IKs in repolarization reserve differences. Thus, humans show greater repolarization-delaying effects of IKr block than dogs, because of lower repolarization reserve contributions from IK1 and IKs, emphasizing species-specific determinants of repolarization and the limitations of animal models for human disease. PMID:23878377

  13. Modulation of long-range neural synchrony reflects temporal limitations of visual attention in humans

    PubMed Central

    Gross, Joachim; Schmitz, Frank; Schnitzler, Irmtraud; Kessler, Klaus; Shapiro, Kimron; Hommel, Bernhard; Schnitzler, Alfons

    2004-01-01

    Because of attentional limitations, the human visual system can process for awareness and response only a fraction of the input received. Lesion and functional imaging studies have identified frontal, temporal, and parietal areas as playing a major role in the attentional control of visual processing, but very little is known about how these areas interact to form a dynamic attentional network. We hypothesized that the network communicates by means of neural phase synchronization, and we used magnetoencephalography to study transient long-range interarea phase coupling in a well studied attentionally taxing dual-target task (attentional blink). Our results reveal that communication within the fronto-parieto-temporal attentional network proceeds via transient long-range phase synchronization in the beta band. Changes in synchronization reflect changes in the attentional demands of the task and are directly related to behavioral performance. Thus, we show how attentional limitations arise from the way in which the subsystems of the attentional network interact. PMID:15328408

  14. Limited human infection due to recombinant raccoon pox virus

    USGS Publications Warehouse

    Rocke, T.E.; Dein, F.J.; Fuchsberger, M.; Fox, B.C.; Stinchcomb, D.T.; Osorio, J.G.

    2004-01-01

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  15. Primary structure of the human laminin A chain. Limited expression in human tissues.

    PubMed Central

    Nissinen, M; Vuolteenaho, R; Boot-Handford, R; Kallunki, P; Tryggvason, K

    1991-01-01

    cDNA clones for the human laminin A chain were isolated from libraries prepared from human gestational choriocarcinoma cell line (JAR) RNA. They cover approx. 8 kb from the 5'-end of the 9.5 kb mRNA coding for this protein. Our clones contain 94 nucleotide residues for the 5'-end untranslated region and 7885 nucleotide residues of coding sequence. The complete human laminin A chain contains a 17-amino acid-residue signal peptide and a 3058-residue A chain proper. The human laminin A chain has a distinct domain structure with numerous internal cysteine-rich repeats. The large globular domain G has five repeats, which have several conserved glycine and cysteine residues. Furthermore the A chain contains 20 internal cysteine-rich repeats present in tandem arrays in three separate clusters (domains IIIa, IIIb and V). Domain I + II has a predicted continuous alpha-helical structure characterized by heptad repeats and three domains (IVa, IVb and VI) are predicted to contain a number of beta-sheets and coiled-coil structures. Northern-blot analysis was used to study the laminin A chain expression in the JAR cell line, full-term placenta and newborn-human tissues (kidney, spleen, lung, heart muscle, psoas muscle and diaphragm muscle). The expression was detectable in newborn-human kidney and JAR cell line only. The overall amino acid sequence identity between human and mouse is 76%. The human chain has only one Arg-Gly-Asp (RGD) sequence, which is located in the long arm within domain G, whereas the single RGD sequence in the mouse chain is located in the short arm in domain IIIb. The degree of identity between the human laminin A chain sequence and the sequence available for merosin [Ehrig, Leivo, Argraves, Ruoslahti & Engvall (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 3264-3268] is about 41% and when conservative substitutions are included the degree of similarity is 54%. Images Fig. 3. PMID:2049067

  16. Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

    PubMed

    Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-Ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

    2015-07-10

    Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. PMID:26003451

  17. Sugar and Dental Caries: A Review of Human Studies

    Microsoft Academic Search

    Ernest Newbrun

    1982-01-01

    Studies of special population groups, epidemiological surveys, controlled longitudinal studies of humans, and longitudinal studies on the effect of sugar substitutes indicate that frequent or high intake of sugary foods predisposes to dental decay. The relation is not always clear-cut, and most studies have important methodological problems and limitations. Longitudinal measurements of caries increments combined with multiple dietary histories are

  18. A mathematical model for a limited sociologically structured human community

    Microsoft Academic Search

    V. Skakauskas

    2000-01-01

    A model for a pair formation in the age-sex and religion-structured human community whose vital rates depend on the total\\u000a population is presented. The model describes the dynamics of interacting religions, which tolerate both uniconfessional pairs\\u000a and those with different religions. Two special cases of vital rates are considered, and existence and uniqueness theorems\\u000a are proved.

  19. The fanconi anemia pathway limits human papillomavirus replication.

    PubMed

    Hoskins, Elizabeth E; Morreale, Richard J; Werner, Stephen P; Higginbotham, Jennifer M; Laimins, Laimonis A; Lambert, Paul F; Brown, Darron R; Gillison, Maura L; Nuovo, Gerard J; Witte, David P; Kim, Mi-Ok; Davies, Stella M; Mehta, Parinda A; Butsch Kovacic, Melinda; Wikenheiser-Brokamp, Kathryn A; Wells, Susanne I

    2012-08-01

    High-risk human papillomaviruses (HPVs) deregulate epidermal differentiation and cause anogenital and head and neck squamous cell carcinomas (SCCs). The E7 gene is considered the predominant viral oncogene and drives proliferation and genome instability. While the implementation of routine screens has greatly reduced the incidence of cervical cancers which are almost exclusively HPV positive, the proportion of HPV-positive head and neck SCCs is on the rise. High levels of HPV oncogene expression and genome load are linked to disease progression, but genetic risk factors that regulate oncogene abundance and/or genome amplification remain poorly understood. Fanconi anemia (FA) is a genome instability syndrome characterized at least in part by extreme susceptibility to SCCs. FA results from mutations in one of 15 genes in the FA pathway, whose protein products assemble in the nucleus and play important roles in DNA damage repair. We report here that loss of FA pathway components FANCA and FANCD2 stimulates E7 protein accumulation in human keratinocytes and causes increased epithelial proliferation and basal cell layer expansion in the HPV-positive epidermis. Additionally, FANCD2 loss stimulates HPV genome amplification in differentiating cells, demonstrating that the intact FA pathway functions to restrict the HPV life cycle. These findings raise the possibility that FA genes suppress HPV infection and disease and suggest possible mechanism(s) for reported associations of HPV with an FA cohort in Brazil and for allelic variation of FA genes with HPV persistence in the general population. PMID:22623785

  20. [Laryngeal ultrasound studies: potential, prospects, limitations].

    PubMed

    Ol'khova, E B; Soldatski?, Iu L; Onufrieva, E K; Shchepin, N V

    2009-01-01

    In the last years, laryngeal ultrasound has been finding increasingly wide application due to the growing availability of relevant up-to-date equipment, apparent technical simplicity and non-invasive character of the study. However, poor knowledge of the physical basis of this method coupled to ungrounded self-confidence of the operators and uncritical treatment of the obtained findings may lead to the overestimation of the diagnostic potential of this sonographic technique. This paper is focused on disadvantages of ultrasound examination of the larynx and associated acoustic artefacts that can be taken for true abnormal structures. Attempts at qualitative and quantitative interpretation of such images are fraught with wrong conclusions. PMID:20037547

  1. Copyright QinetiQ limited 2005 Human Interaction with Teams of

    E-print Network

    Cummings, Mary "Missy"

    Richards MIT Humans & Technology Symposium 24.01.2006 #12;© Copyright QinetiQ limited 2006 Contents 1 of autonomy interface · Mission re-planning interface · Information sharing · Control sharing · Handover

  2. Limits

    NSDL National Science Digital Library

    David Liao

    Students will see how the idea of a limit can be presented both in formal epsilon-delta-style terms, and using corresponding animations. After calculating a limit for a simple example function, we point out that limits do not always exist.

  3. PINEAL MELATONIN LEVEL DISRUPTION IN HUMANS DUE TO ELECTROMAGNETIC FIELDS AND ICNIRP LIMITS

    E-print Network

    Halgamuge, Malka N.

    PINEAL MELATONIN LEVEL DISRUPTION IN HUMANS DUE TO ELECTROMAGNETIC FIELDS AND ICNIRP LIMITS Malka N) classifies electromagnetic fields (EMFs) as `possibly carcinogenic' to humans that might transform normal gland ac- tivity in the brain that regulates the body's sleep­wake cycle. How man-made EMFs may

  4. Human epididymis protein 4 reference limits and natural variation in a Nordic reference population.

    PubMed

    Bolstad, Nils; Øijordsbakken, Miriam; Nustad, Kjell; Bjerner, Johan

    2012-02-01

    The objectives of this study are to establish reference limits for human epididymis protein 4, HE4, and investigate factors influencing HE4 levels in healthy subjects. HE4 was measured in 1,591 samples from the Nordic Reference Interval Project Bio-bank and Database biobank, using the manual HE4 EIA (Fujirebio) for 802 samples and the Architect HE4 (Abbott) for 792 samples. Reference limits were calculated using the statistical software R. The influence of donor characteristics such as age, sex, body mass index, smoking habits, and creatinine on HE4 levels was investigated using a multivariate model. The study showed that age is the main determinant of HE4 in healthy subjects, corresponding to 2% higher HE4 levels at 30 years (compared to 20 years), 9% at 40 years, 20% at 50 years, 37% at 60 years, 63% at 70 years, and 101% at 80 years. HE4 levels are 29% higher in smokers than in nonsmokers. In conclusion, HE4 levels in healthy subjects are associated with age and smoking status. Age-dependent reference limits are suggested. PMID:22105734

  5. Limits to human performance: elevated risks on high mountains.

    PubMed

    Huey, R B; Eguskitza, X

    2001-09-01

    In 1950, Maurice Herzog and Louis Lachenal became the first climbers to reach the summit of an 8000m peak (Annapurna, 8091m). In the half century since that pioneering climb, mountaineers have increasingly sought to climb the fourteen '8K peaks' of the Himalayas and Karakoram, with remarkable success; they have made 5085 ascents of those peaks up to the year 2000. While seeking adventure on those great peaks, mountaineers are inevitably exposed to hypoxia, cold and dehydration as well as to the physical hazards of climbing. Those few mountaineers who successfully summit an 8K peak are likely to be at or near their physiological limits and probably confront an elevated probability of dying during their descent. We will briefly review some of the physiological challenges climbers face at extreme elevation and then compare success rates and death rates on mountains of different heights (Rainer, Foraker, Denali, K2, Everest). Success rates decline with summit height, but overall death rates and death rates during descent from the summit increase with summit height. Although these patterns are based on non-experimental and uncontrolled data, our findings are consistent with the hypothesis that increasing altitude is associated with decreased success and with increased risk of death. PMID:11581324

  6. Human and Macaque Mastication: A Quantitative Study

    Microsoft Academic Search

    Kenneth E. Byrd; Diane J. Milberg; Erich S. Luschei

    1978-01-01

    Significant differences exist between human and Macaca fascicularis patterns of mandibular movement during mastication. Macaque patterns display less asymmetry, more uniformity, and limited lateral excursions when compared to humans for mastication of the same food. Different anatomical structures between the two species offer explanations of the different patterns that were observed. Researchers should use caution when using macaques as models

  7. Humanized Mouse Model to Study Bacterial Infections Targeting the Microvasculature

    PubMed Central

    Melican, Keira; Aubey, Flore; Duménil, Guillaume

    2014-01-01

    Neisseria meningitidis causes a severe, frequently fatal sepsis when it enters the human blood stream. Infection leads to extensive damage of the blood vessels resulting in vascular leak, the development of purpuric rashes and eventual tissue necrosis. Studying the pathogenesis of this infection was previously limited by the human specificity of the bacteria, which makes in vivo models difficult. In this protocol, we describe a humanized model for this infection in which human skin, containing dermal microvessels, is grafted onto immunocompromised mice. These vessels anastomose with the mouse circulation while maintaining their human characteristics. Once introduced into this model, N. meningitidis adhere exclusively to the human vessels, resulting in extensive vascular damage, inflammation and in some cases the development of purpuric rash. This protocol describes the grafting, infection and evaluation steps of this model in the context of N. meningitidis infection. The technique may be applied to numerous human specific pathogens that infect the blood stream. PMID:24747976

  8. Determination of torque-limits for human and cat lumbar spine specimens during displacement-controlled physiological motions

    PubMed Central

    Ianuzzi, Allyson; Pickar, Joel G.; Khalsa, Partap S.

    2009-01-01

    Background Context Quadruped animal models have been validated and utilized as biomechanical models for the lumbar spine. The biomechanics of the cat lumbar spine has not been well characterized, even though it is a common model used in neuromechanical studies. Purpose Compare the physiological ranges of motion and determine torque-limits for cat and human lumbar spine specimens during physiological motions. Study Design/Setting Biomechanics study. Patient Sample Cat and human lumbar spine specimens. Outcome measures Intervertebral angle (IVA), joint moment, yield point, torque-limit, correlation coefficients. Methods Cat (L2-sacrum) and human (T12-sacrum) lumbar spine specimens were mechanically tested to failure during displacement-controlled extension, lateral bending, and axial rotation. Single trials consisted of 10 cycles (10mm/s or 5°/s) to a target displacement where the magnitude of the target displacement was increased for subsequent trials until failure occurred. Whole-lumbar stiffness, torque at yield point, and joint stiffness were determined. Scaling relationships were established using equations analogous to those that describe the load response of elliptically-shaped beams. Results IVA magnitudes for cat and human lumbar spines were similar during physiological motions. Human whole-lumbar and joint stiffness magnitudes were significantly greater than those for cat spine specimens (p<0.05). Torque-limits were also greater for humans compared to cats. Scaling relationships with high correlation (R2>0.77) were established during later lateral bending and axial rotation. Conclusions The current study defined “physiological ranges of movement” for human and cat lumbar spine specimens during displacement-controlled testing, and should be observed in future biomechanical studies conducted under displacement control. PMID:17983845

  9. Studies of the limit order book around large price changes

    Microsoft Academic Search

    Bence Toth; Janos Kertesz; J. Doyne Farmer

    We study the dynamics of the limit order book of liquid stocks after experiencing large intra-day price changes. In the data we find large variations in several microscopical measures, e.g., the volatility the bid-ask spread, the bid-ask imbalance, the number of queuing limit orders, the activity (number and volume) of limit orders placed and canceled, etc. The relaxation of the

  10. Limitations to Thermoregulation and Acclimatization Challenge Human Adaptation to Global Warming.

    PubMed

    Hanna, Elizabeth G; Tait, Peter W

    2015-07-01

    Human thermoregulation and acclimatization are core components of the human coping mechanism for withstanding variations in environmental heat exposure. Amidst growing recognition that curtailing global warming to less than two degrees is becoming increasing improbable, human survival will require increasing reliance on these mechanisms. The projected several fold increase in extreme heat events suggests we need to recalibrate health protection policies and ratchet up adaptation efforts. Climate researchers, epidemiologists, and policy makers engaged in climate change adaptation and health protection are not commonly drawn from heat physiology backgrounds. Injecting a scholarly consideration of physiological limitations to human heat tolerance into the adaptation and policy literature allows for a broader understanding of heat health risks to support effective human adaptation and adaptation planning. This paper details the physiological and external environmental factors that determine human thermoregulation and acclimatization. We present a model to illustrate the interrelationship between elements that modulate the physiological process of thermoregulation. Limitations inherent in these processes, and the constraints imposed by differing exposure levels, and thermal comfort seeking on achieving acclimatization, are then described. Combined, these limitations will restrict the likely contribution that acclimatization can play in future human adaptation to global warming. We postulate that behavioral and technological adaptations will need to become the dominant means for human individual and societal adaptations as global warming progresses. PMID:26184272

  11. Safe human exposure limits for airborne linear siloxanes during spaceflight

    PubMed Central

    García, Hector D.; McMullin, Tami S.; Tobin, Joseph M.; James, John T.

    2013-01-01

    Background Low molecular weight siloxanes are used in industrial processes and consumer products, and their vapors have been detected in the atmospheres of the Space Shuttle and International Space Station. Therefore, the National Aeronautics and Space Administration (NASA) developed spacecraft maximum allowable concentrations (SMACs) for siloxane vapors to protect astronaut health. Since publication of these original SMACs, new studies and new risk assessment approaches have been published that warrant re-examination of the SMACs. Objective To reevaluate SMACs published for octamethyltrisiloxane (L3) for exposures ranging from 1 hour to 180 days, to develop a 1000-day SMAC, and to expand the applicability of those values to the family of linear siloxanes. Methods A literature review was conducted to identify studies conducted since the SMACs for L3 were set in 1994. The updated data were reviewed to determine the sensitive toxicity endpoints, and current risk assessment approaches and methods for dosimetric adjustments were evaluated. Results Recent data were used to update the original 1-hour, 24-hour, 30-day, and 180-day SMACs for L3, and a 1000-day SMAC was developed to protect crewmembers during future exploration beyond Earth orbit. Group SMACs for the linear siloxane family, including hexamethyldisiloxane (L2), L3, decamethyltetrasiloxane (L4), and dodecamethylpentasiloxane (L5), were set for exposures of 1-hour to 1000 days. Conclusion New SMACs, based on acute pulmonary and neurotoxicity at high doses only achievable with L2 and potential liver effects following longer-term exposures to L2 and L3, were established to protect crewmembers from the adverse effects of exposure to linear siloxanes. PMID:24255951

  12. Epidemiological studies in human radiobiology*

    PubMed Central

    1967-01-01

    A meeting on the contribution of epidemiological studies to the better understanding of the effects of radiation on human health was held in Washington, D.C., from 13 to 17 December 1965. This meeting was organized and sponsored by the World Health Organization, with the co-operation of the Division of Radiological Health, Public Health Service, United States Department of Health, Education, and Welfare. The main emphasis of the meeting was on obtaining representative views on the epidemiological studies now in progress and on the possibilities for further studies, but past work was also briefly reviewed under such headings as leukaemia, lung and other tumours, congenital malformations and cytogenetic effects. In addition, information was presented on current concepts of the mechanism of carcinogenesis and life-shortening derived from experimental and theoretical work. Against this background an attempt was made to identify the most essential needs for epidemiological data at present and to consider how such data might be obtained. The text presented below was prepared by Professor L. F. Lamerton of the Department of Biophysics, Institute of Cancer Research (Surrey Branch), Sutton, Surrey, England, and Professor B. MacMahon of the Department of Epidemiology, Harvard University School of Public Health, Boston, Mass., USA. It is a précis of some of the views expressed and of the information and the suggestions made. PMID:20604319

  13. Experimental study on the velocity limits of magnetized rotating plasmas

    Microsoft Academic Search

    Catalin Teodorescu; Ryan Clary; Richard Ellis; Adil Hassam; Ilker Uzun-Kaymak

    2007-01-01

    An experimental study on the physical limits of the rotation velocity of magnetized plasmas is presented. A comprehensive campaign has been carried out on the MCX, a mirror magnetic field plasma rotating azimuthally, to ascertain what physical effects limit attempts to externally boost the velocity. The externally applied parameters that control the plasma characteristics -- applied voltage, external magnetic field

  14. Mapping by admixture linkage disequilibrium in human populations: Limits and guidelines

    SciTech Connect

    Stephens, J.C.; Briscoe, D.; O`Brien, S.J. [National Institutes of Health, Frederick, MD (United States)

    1994-10-01

    Certain human hereditary conditions, notably those with low penetrance and those which require an environmental event such as infectious disease exposure, are difficult to localize in pedigree analysis, because of uncertainty in the phenotype of an affected patient`s relatives. An approach to locating these genes in human cohort studies would be to use association analysis, which depends on linkage disequilibrium of flanking polymorphic DNA markers. In theory, a high degree of linkage disequilibrium between genes separated by 10-20 cM will be generated and persist in populations that have a history of recent (3-20 generations ago) admixture between genetically differentiated racial groups, such as has occurred in African Americans and Hispanic populations. We have conducted analytic and computer simulations to quantify the effect of genetic, genomic, and population parameters that affect the amount and ascertainment of linkage disequilibrium in populations with a history of genetic admixture. Our goal is to thoroughly explore the ranges of all relevant parameters or factors (e.g., sample size and degree of genetic differentiation between populations) that may be involved in gene localization studies, in hopes of prescribing guidelines for an efficient mapping strategy. The results provide reasonable limits on sample size (200-300 patients), marker number (200-300 in 20-cM intervals), and allele differentiation (loci with allele frequency difference of {ge}.3 between admixed parent populations) to produce an efficient approach (>95% ascertainment) for locating genes not easily tracked in human pedigrees. 321 refs., 8 figs., 7 tabs.

  15. Evidence that calcineurin is rate-limiting for primary human lymphocyte activation.

    PubMed Central

    Batiuk, T D; Kung, L; Halloran, P F

    1997-01-01

    Cyclosporine (CsA) is both a clinical immunosuppressive drug and a probe to dissect intracellular signaling pathways. In vitro, CsA inhibits lymphocyte gene activation by inhibiting the phosphatase activity of calcineurin (CN). In clinical use, CsA treatment inhibits 50-75% of CN activity in circulating leukocytes. We modeled this degree of CN inhibition in primary human leukocytes in vitro in order to study the effect of partial CN inhibition on the downstream signaling events that lead to gene activation. In CsA-treated leukocytes stimulated by calcium ionophore, the degree of reduction in CN activity was accompanied by a similar degree of inhibition of each event tested: dephosphorylation of nuclear factor of activated T cell proteins, nuclear DNA binding, activation of a transfected reporter gene construct, IFN-gamma and IL-2 mRNA accumulation, and IFN-gamma production. Furthermore, the degree of CN inhibition was reflected by a similar degree of reduction in lymphocyte proliferation and IFN-gamma production in the allogeneic mixed lymphocyte cultures. These data support the conclusion that CN activity is rate-limiting for the activation of primary human T lymphocytes. Thus, the reduction of CN activity observed in CsA-treated patients is accompanied by a similar degree of reduction in lymphocyte gene activation, and accounts for the immunosuppression observed. PMID:9312192

  16. A limited assessment of the ASEP human reliability analysis procedure using simulator examination results

    SciTech Connect

    Gore, B.R.; Dukelow, J.S. Jr.; Mitts, T.M.; Nicholson, W.L. [Pacific Northwest Lab., Richland, WA (United States)

    1995-10-01

    This report presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. In particular, the, ASEP post-accident, post-diagnosis, nominal HRA procedure is assessed within the context of an individual`s performance of critical tasks on the simulator portion of requalification examinations administered to nuclear power plant operators. An assessment of the degree to which operator perforn:Lance during simulator examinations is an accurate reflection of operator performance during actual accident conditions was outside the scope of work for this project; therefore, no direct inference can be made from this report about such performance. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle. A total of 4071 critical tasks were identified, of which 45 had been failed. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. ASEP analyses were performed for a sample of 162 critical tasks selected randomly from the 4071, and the results were used to characterize the entire population. ASEP analyses were also performed for all of the 45 failed critical tasks. Two tests were performed to assess the bias of the ASEP HEPs compared with the data from the requalification examinations. The first compared the average of the ASEP HEP values with the fraction of the population actually failed and it found a statistically significant factor of two bias on the average.

  17. Mockups and human productivity studies

    NASA Technical Reports Server (NTRS)

    Fisher, T.

    1985-01-01

    Idea outlines are presented concerning mockup candidates, mockup utilization and schedules/sequence in mockup development. Mockup candidates which aid in human productivity investigations and assessment are given. Areas which are considered in the mockups are the safe haven zone, general purpose workstations, maintenance and servicing area, sleep quaters, multiple docking adapter, airlock, hygiene station, food station, habitation zones, group gathering area and lab areas. Some aesthetic concerns in human productivity are also given.

  18. critcial human health issues in connection with future human missions to mMars: the HUMEX study of ESA

    Microsoft Academic Search

    G. Horneck

    2004-01-01

    ESA has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis was laid on human health and performance care as well as Advanced Life Support Developments including Bioregenerative Life Support Systems and environmental monitoring. The overall study goals were as follows: (i) to define reference scenarios

  19. A study of fundamental limitations of small antennas: MIMO approach

    NASA Astrophysics Data System (ADS)

    Mattigiri, S.; Warty, C.

    In this area of high performance systems and sophistication, the antenna size is shrinking drastically. This paper reviews the fundamental limitations in electrically instigated small antennas and their implications on multiple input multiple output (MIMO) systems. An optimum performance of the antenna can be obtained by considering three main factors. (1) maximum gain for given frequency (2) minimum Q factor (3) maximum ratio of G/Q. It is essential to understand the basic concepts of these small antennas to counter the limitations for next generational systems. In this paper works of three prominent scientists like Wheeler, Hansen and Chu have been studied to understand these limitations. This study can be further expanded to accumulate various space time diverse MIMO systems specified in long Term Evolution-Advanced (LTE-A) standards. The impact of limitations of small antennas can be very significant on the performance of the given node.

  20. Studies of the limit order book around large price changes

    Microsoft Academic Search

    B. Tóth; J. Kertész; J. Doyne Farmer

    2009-01-01

    We study the dynamics of the limit order book of liquid stocks after\\u000a experiencing large intra-day price changes.\\u000a In the data we find large variations in several microscopical measures, e.g.,\\u000a the volatility the bid-ask spread, the bid-ask imbalance, the number of\\u000a queuing limit orders, the activity (number and volume) of limit orders\\u000a placed and canceled, etc. The relaxation of the

  1. Driven diffusive system: A study on large n limit

    Microsoft Academic Search

    Sutapa Mukherji

    2000-01-01

    :   We study the generalized n component model of a driven diffusive system with annealed random drive in the large n limit. This non-equilibrium model also describes conserved order parameter dynamics of an equilibrium model of ferromagnets\\u000a with dipolar interaction. In this limit, at zero temperature a saddle point approximation becomes exact. The length scale\\u000a in the direction transverse to

  2. Studies on the human choroid plexus in vitro.

    PubMed

    Redzic, Zoran B

    2013-01-01

    The role of human choroid plexus (CP) epithelium in the transport of solutes between the blood and the cerebrospinal fluid and/or in secretion processes may be studied by employing several experimental approaches. There are a number of in vitro techniques for human CP epithelium (CPE) and all have limitations that do not exclude them a priori, but that should be carefully taken into consideration. Developmental and morphological studies have been largely performed on human choroid plexus samples of either embryonic or post-mortem origin. Functional uptake studies may be performed on pathologically unaltered CP samples obtained during surgical removal of choroid plexus tumors. This approach can be used to explore transport processes mainly across the apical side of the CPE, but cannot be used to study vectorial transport across the CPE. Also, these samples have limited viability. A monolayer of CPE in culture, grown on permeable supports, provides the best available tool to study transport processes or polarized secretion by the CP, but thus far only limited attempts to culture these cells have been published and they mainly include data from neoplastic CPE. A study that used a human papilloma-derived cell line in culture showed that it forms a monolayer with barrier properties, although the cells express pleomorphic and neoplastic features and lack contact inhibition. Other cell cultures express some CPE markers but do not develop tight junctions/barrier properties. This article reviews the main characteristics and limitations of available in vitro methods to study human CPE, which could help researchers choose an appropriate experimental approach for a particular study. PMID:23391221

  3. Studies on the human choroid plexus in vitro

    PubMed Central

    2013-01-01

    The role of human choroid plexus (CP) epithelium in the transport of solutes between the blood and the cerebrospinal fluid and/or in secretion processes may be studied by employing several experimental approaches. There are a number of in vitro techniques for human CP epithelium (CPE) and all have limitations that do not exclude them a priori, but that should be carefully taken into consideration. Developmental and morphological studies have been largely performed on human choroid plexus samples of either embryonic or post-mortem origin. Functional uptake studies may be performed on pathologically unaltered CP samples obtained during surgical removal of choroid plexus tumors. This approach can be used to explore transport processes mainly across the apical side of the CPE, but cannot be used to study vectorial transport across the CPE. Also, these samples have limited viability. A monolayer of CPE in culture, grown on permeable supports, provides the best available tool to study transport processes or polarized secretion by the CP, but thus far only limited attempts to culture these cells have been published and they mainly include data from neoplastic CPE. A study that used a human papilloma-derived cell line in culture showed that it forms a monolayer with barrier properties, although the cells express pleomorphic and neoplastic features and lack contact inhibition. Other cell cultures express some CPE markers but do not develop tight junctions/barrier properties. This article reviews the main characteristics and limitations of available in vitro methods to study human CPE, which could help researchers choose an appropriate experimental approach for a particular study. PMID:23391221

  4. Temporal Limitations in Object Processing Across the Human Ventral Visual Pathway

    E-print Network

    Tong, Frank

    processing capacity of early visual areas tuned to basic features or high-level areas tuned to complex 2004; Potter 1975), whereas basic visual changes involving flicker or motion can be detected at ratesTemporal Limitations in Object Processing Across the Human Ventral Visual Pathway Thomas J. Mc

  5. A human study of fault localization accuracy

    Microsoft Academic Search

    Zachary P. Fry; Westley Weimer

    2010-01-01

    Localizing and repairing defects are critical software engineering activities. Not all programs and not all bugs are equally easy to debug, however. We present formal models, backed by a human study involving 65 participants (from both academia and industry) and 1830 total judgments, relating various software- and defect-related features to human accuracy at locating errors. Our study involves example code

  6. Problems and limitations in studies on screening for language delay.

    PubMed

    Eriksson, Mårten; Westerlund, Monica; Miniscalco, Carmela

    2010-01-01

    This study discusses six common methodological limitations in screening for language delay (LD) as illustrated in 11 recent studies. The limitations are (1) whether the studies define a target population, (2) whether the recruitment procedure is unbiased, (3) attrition, (4) verification bias, (5) small sample size and (6) inconsistencies in choice of "gold standard". It is suggested that failures to specify a target population, high attrition (both at screening and in succeeding validation), small sample sizes and verification bias in validations are often caused by a misguided focus on screen positives (SPs). Other limitations are results of conflicting methodological goals. We identified three such conflicts. One consists of a dilemma between unbiased recruitment and attrition, another between the comprehensiveness of the applied gold standard and sample size in validation and the third between the specificity of the gold standard and the risk of not identifying co-morbid conditions. PMID:20483561

  7. Experimental study on the velocity limits of magnetized rotating plasmas

    Microsoft Academic Search

    C. Teodorescu; R. Clary; R. F. Ellis; A. B. Hassam; R. Lunsford; I. Uzun-Kaymak; W. C. Young

    2008-01-01

    An experimental study on the physical limits of the rotation velocity of magnetized plasmas is presented. Experiments are performed in the Maryland Centrifugal Experiment (MCX) [R. F. Ellis et al., Phys. Plasmas 12, 055704 (2005)], a mirror magnetic field plasma rotating azimuthally. The externally applied parameters that control the plasma characteristics-applied voltage, external magnetic field, and fill pressure-are scanned across

  8. A Comparative Study of Limited Range Wavelength Conversion Policies for

    E-print Network

    Akar, Nail

    ) packet'' and ``(optical) packet switching'' to refer to a packet/burst and the data planes of OPS for supporting asynchronous IP networks with variable sized data packets. Therefore, we focus our attentionA Comparative Study of Limited Range Wavelength Conversion Policies for Asynchronous Optical Packet

  9. Vagus nerve stimulation suppresses pain but has limited effects on neurogenic inflammation in humans

    Microsoft Academic Search

    Annette Kirchner; Hermann Stefan; Katrin Bastian; Frank Birklein

    2006-01-01

    Left vagus nerve stimulation reduces pain perception in humans. In animal studies it has been shown that beyond the inhibitory effect, which the vagus nerve exerts via its widespread central connections, there might be also a peripheral effect on nociceptors. In humans, the exact mechanisms of VNS-mediated analgesia are still unclear.To test whether VNS also affects activation of primary nociceptive

  10. Sugar and dental caries: a review of human studies.

    PubMed

    Newbrun, E

    1982-07-30

    Studies of special population groups, epidemiological surveys, controlled longitudinal studies of humans, and longitudinal studies on the effect of sugar substitutes indicate that frequent or high intake of sugary foods predisposes to dental decay. The relation is not always clear-cut, and most studies have important methodological problems and limitations. Longitudinal measurements of caries increments combined with multiple dietary histories are needed to clarity the association between caries and eating habits. The relative cariogenicity of specific foods can be assessed by a combination of in vitro tests, human in vivo tests, and experimental caries in animals. Human diets, however, vary in food items eaten and the frequency and sequence of eating, and these factors can affect the cariogenicity of a food. Therefore, reported correlations must be interpreted with caution. PMID:7046052

  11. Proteomic View of Basement Membranes from Human Retinal Blood Vessels, Inner Limiting Membranes, and Lens Capsules.

    PubMed

    Uechi, Guy; Sun, Zhiyuan; Schreiber, Emanuel M; Halfter, Willi; Balasubramani, Manimalha

    2014-07-17

    Basement membranes (BMs) are extracellular matrix sheets comprising the laminins, type-IV collagens, nidogens, and the heparan sulfate proteoglycans, perlecan, collagen XVIII, and agrin. In intact BMs, BM proteins are physiologically insoluble and partially resistant to proteolytic digestion, making BMs a challenge to study. Here three types of BMs from adult human eyes, the inner limiting membrane (ILM), the retinal vascular BMs, and the lens capsule, were isolated for analysis by 1D-SDS-PAGE and LC-MS/MS. Peptide and protein identifications were done using MaxQuant. 1129 proteins were identified with a 1% false discovery rate. Data showed that BMs are composed of multiple laminins, collagen IVs, nidogens, and proteoglycans. The dominant laminin family member in all BMs was laminin ?5?2?1. The dominant collagen IV trimer in lens capsule (LC) and blood vessel (BV) BMs had a chain composition of ?1(IV)2, ?2 (IV), whereas the dominant collagen IV in the ILM had the ?3(IV), ?4(IV), ?5(IV) chain composition. The data also showed that the ratio of laminin and collagen IVs varied among different BM types: the ratio of collagen IV to the other BM proteins is highest in LC, followed by BV and lowest for the ILM. The data have been deposited to the ProteomeXchange with identifier PXD001025. PMID:24990792

  12. Studying dialects to understand human language

    E-print Network

    Nti, Akua Afriyie

    2009-01-01

    This thesis investigates the study of dialect variations as a way to understand how humans might process speech. It evaluates some of the important research in dialect identification and draws conclusions about how their ...

  13. Community Engagement in Observational Human Exposure Studies

    EPA Science Inventory

    Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

  14. Setting occupational exposure limits in humans: contributions from the field of experimental psychology

    Microsoft Academic Search

    Monique A. M. Smeets; Jan H. A. Kroeze; Pamela H. Dalton

    2006-01-01

    Psychophysical methods from the field of experimental psychology are evaluated for their utility in the derivation of occupational\\u000a exposure limits (OELs) for volatile chemicals based on acute sensory irritation in humans. The lateralization threshold method,\\u000a which involves the localization of trigeminal vapor to the stimulated nostril, is evaluated for its underlying assumptions,\\u000a reliability and validity. Whole body exposures, on the

  15. Predicting Nursing Human Resources: An Exploratory Study

    PubMed Central

    Squires, Allison; Beltrán-Sánchez, Hiram

    2010-01-01

    The nurse-to-population ratio (NPOP) is a standard indicator used to indicate a country’s health care human resources capacity for responding to its disease burden. This study sought to explore if socioeconomic development indicators could predict the NPOP in a country. Mexico served as the case example for this exploratory study, with the final five variables selected based on findings from a qualitative study analyzing the development of nursing human resources in the country. Multiple linear regression showed that two variables proved significant predictors of the NPOP and the model itself explained 70% of the variance (r2 = .7; p = .0000). The findings have multiple implications for nursing human resources policy in Mexico and at a global level as governments attempt to build human capital to respond to population health needs. PMID:19628510

  16. Scientific research and human rights: a response to Kitcher on the limitations of inquiry.

    PubMed

    Victor, Elizabeth

    2014-12-01

    In his recent work exploring the role of science in democratic societies Kitcher (Science in a democratic society. Prometheus Books, New York, 2011) claims that scientists ought to have a prominent role in setting the agenda for and limits to research. Against the backdrop of the claim that the proper limits of scientific inquiry is John Stuart Mill’s Harm Principle (Kitcher in Science, truth, and democracy. Oxford University Press, New York, 2001), he identifies the limits of inquiry as the point where the outcomes of research could cause harm to already vulnerable populations. Nonetheless, Kitcher argues against explicit limitations on unscrupulous research on the grounds that restrictions would exacerbate underlying social problems. I show that Kitcher’s argument in favor of dissuading inquiry through conventional standards is problematic and falls prey to the same critique he offers in opposition to official bans. I expand the conversation of limiting scientific research by recognizing that the actions that count as ‘science’ are located in the space between ‘thinking’ and ‘doing’. In this space, we often attempt to balance freedom of research, as scientific speech, against the disparate impact citizens might experience in light of such research. I end by exploring if such disparate impact justifies limiting research, within the context of the United States, under Title VII of the Civil Rights Act of 1964 or under international human rights standards more generally. PMID:24235027

  17. Lesson Study by Secondary Humanities Teachers

    ERIC Educational Resources Information Center

    Carpenter, Jeffrey Paul

    2009-01-01

    This study examined the experiences of a group of American secondary humanities teachers engaged in lesson study. Lesson study (LS) is a teacher-driven, collaborative inquiry process grounded in the realities of the classroom. It is an approach to professional development (PD) that originated in Japan, and has been credited there with contributing…

  18. New horizons for studying human hepatotropic infections

    PubMed Central

    de Jong, Ype P.; Rice, Charles M.; Ploss, Alexander

    2010-01-01

    The liver serves as a target organ for several important pathogens, including hepatitis B and C viruses (HBV and HCV, respectively) and the human malaria parasites, all of which represent serious global health problems. Because these pathogens are restricted to human hepatocytes, research in small animals has been compromised by the frailty of the current mouse xenotransplantation models. In this issue of the JCI, Bissig et al. demonstrate robust HBV and HCV infection in a novel xenotransplantation model in which large numbers of immunodeficient mice with liver injury were engrafted with significant quantities of human hepatocytes. This technical advance paves the way for more widespread use of human liver chimeric mice and forms the basis for creating increasingly complex humanized mouse models that could prove useful for studying immunopathogenesis and vaccine development against hepatotropic pathogens. PMID:20179350

  19. Study of human bone tumor slice by SRXRF microprobe

    NASA Astrophysics Data System (ADS)

    Huang, Y. Y.; Lu, J. X.; He, R. G.; Zhao, L. M.; Wang, Z. G.; He, W.; Zhang, Y. X.

    2001-07-01

    The SRXRF microprobe at the BSRF is described. The minimum detection limits (MDLs) of trace elements were measured to determine the capability for biological sample analysis. The changes of the trace elements and their ratios in the normal and tumor parts of a human osteosarcoma tissue were investigated. It was found that our results were in agreement with those of other analytical methods, such as spectrophotometric analysis, NAA and PIXE as well as an early clinic study of serum.

  20. Experimental study on the velocity limits of magnetized rotating plasmas

    SciTech Connect

    Teodorescu, C.; Clary, R.; Ellis, R. F.; Hassam, A. B.; Lunsford, R.; Uzun-Kaymak, I.; Young, W. C. [University of Maryland, College Park, Maryland 20742 (United States)

    2008-04-15

    An experimental study on the physical limits of the rotation velocity of magnetized plasmas is presented. Experiments are performed in the Maryland Centrifugal Experiment (MCX) [R. F. Ellis et al., Phys. Plasmas 12, 055704 (2005)], a mirror magnetic field plasma rotating azimuthally. The externally applied parameters that control the plasma characteristics--applied voltage, external magnetic field, and fill pressure--are scanned across the entire available range of values. It is found that the plasma rotation velocity does not exceed the Alfven velocity, in agreement with the equilibrium requirements of magnetically confined plasmas. Measured rotation velocities are also lower than the critical ionization velocity in hydrogen, but a strict limit was not observable within MCX parametric capabilities.

  1. Human Root Caries: Microbiota of a Limited Number of Root Caries Lesions

    Microsoft Academic Search

    P. Schüpbach; V. Osterwalder; B. Guggenheim

    1996-01-01

    The microbiota of root caries lesions of different grades of severity were studied. Fourteen lesions were examined. The experimental design of the study allowed correlation of histopathologically distinguishable stages with specific and distinct microbial populations. Dentin samples were ground in a sterile mortar and cultured anaerobically on nonselective Columbia blood agar plates supplemented with 5% hemolyzed human blood and on

  2. Feasibility study on superconducting fault current limiting transformer (SFCLT)

    Microsoft Academic Search

    N. Hayakawa; S. Chigusa; N. Kashima; S. Nagaya; H. Okubo

    2000-01-01

    This paper proposes a “superconducting fault current limiting transformer (SFCLT)” with functions of both superconducting fault current limiters and superconducting transformers. Concepts of the SFCLT are as follows: (1) When a fault occurs in a power system, the SFCLT acts as a fault current limiter with limiting impedance due to quench of the SFCLT windings, which improves the transient stability

  3. Limiting the impact of light pollution on human health, environment and stellar visibility.

    PubMed

    Falchi, Fabio; Cinzano, Pierantonio; Elvidge, Christopher D; Keith, David M; Haim, Abraham

    2011-10-01

    Light pollution is one of the most rapidly increasing types of environmental degradation. Its levels have been growing exponentially over the natural nocturnal lighting levels provided by starlight and moonlight. To limit this pollution several effective practices have been defined: the use of shielding on lighting fixture to prevent direct upward light, particularly at low angles above the horizon; no over lighting, i.e. avoid using higher lighting levels than strictly needed for the task, constraining illumination to the area where it is needed and the time it will be used. Nevertheless, even after the best control of the light distribution is reached and when the proper quantity of light is used, some upward light emission remains, due to reflections from the lit surfaces and atmospheric scatter. The environmental impact of this "residual light pollution", cannot be neglected and should be limited too. Here we propose a new way to limit the effects of this residual light pollution on wildlife, human health and stellar visibility. We performed analysis of the spectra of common types of lamps for external use, including the new LEDs. We evaluated their emissions relative to the spectral response functions of human eye photoreceptors, in the photopic, scotopic and the 'meltopic' melatonin suppressing bands. We found that the amount of pollution is strongly dependent on the spectral characteristics of the lamps, with the more environmentally friendly lamps being low pressure sodium, followed by high pressure sodium. Most polluting are the lamps with a strong blue emission, like Metal Halide and white LEDs. Migration from the now widely used sodium lamps to white lamps (MH and LEDs) would produce an increase of pollution in the scotopic and melatonin suppression bands of more than five times the present levels, supposing the same photopic installed flux. This increase will exacerbate known and possible unknown effects of light pollution on human health, environment and on visual perception of the Universe by humans. We present quantitative criteria to evaluate the lamps based on their spectral emissions and we suggest regulatory limits for future lighting. PMID:21745709

  4. Deviation of Zipf's and Heaps' Laws in Human Languages with Limited Dictionary Sizes

    PubMed Central

    Lü, Linyuan; Zhang, Zi-Ke; Zhou, Tao

    2013-01-01

    Zipf's law on word frequency and Heaps' law on the growth of distinct words are observed in Indo-European language family, but it does not hold for languages like Chinese, Japanese and Korean. These languages consist of characters, and are of very limited dictionary sizes. Extensive experiments show that: (i) The character frequency distribution follows a power law with exponent close to one, at which the corresponding Zipf's exponent diverges. Indeed, the character frequency decays exponentially in the Zipf's plot. (ii) The number of distinct characters grows with the text length in three stages: It grows linearly in the beginning, then turns to a logarithmical form, and eventually saturates. A theoretical model for writing process is proposed, which embodies the rich-get-richer mechanism and the effects of limited dictionary size. Experiments, simulations and analytical solutions agree well with each other. This work refines the understanding about Zipf's and Heaps' laws in human language systems. PMID:23378896

  5. Real-Time Human Ambulation, Activity, and Physiological Monitoring: Taxonomy of Issues, Techniques, Applications, Challenges and Limitations

    PubMed Central

    Khusainov, Rinat; Azzi, Djamel; Achumba, Ifeyinwa E.; Bersch, Sebastian D.

    2013-01-01

    Automated methods of real-time, unobtrusive, human ambulation, activity, and wellness monitoring and data analysis using various algorithmic techniques have been subjects of intense research. The general aim is to devise effective means of addressing the demands of assisted living, rehabilitation, and clinical observation and assessment through sensor-based monitoring. The research studies have resulted in a large amount of literature. This paper presents a holistic articulation of the research studies and offers comprehensive insights along four main axes: distribution of existing studies; monitoring device framework and sensor types; data collection, processing and analysis; and applications, limitations and challenges. The aim is to present a systematic and most complete study of literature in the area in order to identify research gaps and prioritize future research directions. PMID:24072027

  6. A limit on the energy transfer rate from the human fat store in hypophagia.

    PubMed

    Alpert, Seymour S

    2005-03-01

    A limit on the maximum energy transfer rate from the human fat store in hypophagia is deduced from experimental data of underfed subjects maintaining moderate activity levels and is found to have a value of (290+/-25) kJ/kgd. A dietary restriction which exceeds the limited capability of the fat store to compensate for the energy deficiency results in an immediate decrease in the fat free mass (FFM). In cases of a less severe dietary deficiency, the FFM will not be depleted. The transition between these two dietary regions is developed and a criterion to distinguish the regions is defined. An exact mathematical solution for the decrease of the FFM is derived for the case where the fat mass (FM) is in its limited energy transfer mode. The solution shows a steady-state term which is in agreement with conventional ideas, a term indicating a slow decrease of much of the FFM moderated by the limited energy transferred from the fat store, and a final term showing an unprotected rapid decrease of the remaining part of the FFM. The average resting metabolic rate of subjects undergoing hypophagia is shown to decrease linearly as a function of the FFM with a slope of (249+/-25) kJ/kgd. This value disagrees with the results of other observers who have measured metabolic rates of diverse groups. The disagreement is explained in terms of individual metabolic properties as opposed to those of the larger population. PMID:15615615

  7. Topical Mineralocorticoid Receptor Blockade Limits Glucocorticoid-Induced Epidermal Atrophy in Human Skin.

    PubMed

    Maubec, Eve; Laouénan, Cédric; Deschamps, Lydia; Nguyen, Van Tuan; Scheer-Senyarich, Isabelle; Wackenheim-Jacobs, Anne-Catherine; Steff, Maud; Duhamel, Stéphanie; Tubiana, Sarah; Brahimi, Nesrine; Leclerc-Mercier, Stéphanie; Crickx, Béatrice; Perret, Claudine; Aractingi, Selim; Escoubet, Brigitte; Duval, Xavier; Arnaud, Philippe; Jaisser, Frederic; Mentré, France; Farman, Nicolette

    2015-07-01

    A major deleterious side effect of glucocorticoids is skin atrophy. Glucocorticoids activate the glucocorticoid and the mineralocorticoid (MR) receptor, both present in the epidermis. We hypothesized that glucocorticoid-induced epidermal atrophy may be related to inappropriate occupancy of MR by glucocorticoids. We evaluated whether epidermal atrophy induced by the topical glucocorticoid clobetasol could be limited by coadministration of MR antagonist. In cultured human skin explants, the epidermal atrophy induced by clobetasol was significantly limited by MR antagonism (canrenoate and eplerenone). Blockade of the epithelial sodium channel ENaC by phenamil was also efficient, identifying a role of MR-ENaC cascade in keratinocytes, acting through restoration of clobetasol-induced impairment of keratinocyte proliferation. In the SPIREPI randomized double-blind controlled trial, gels containing clobetasol, the MR antagonist spironolactone, both agents, or placebo were applied on four zones of the forearms of 23 healthy volunteers for 28 days. Primary outcome was histological thickness of the epidermis with clobetasol alone or clobetasol+spironolactone. Spironolactone alone did not affect the epidermal thickness but coapplication of clobetasol and spironolactone significantly limited clobetasol-induced atrophy and was well tolerated. Altogether, these findings identify MR as a factor regulating epidermal homeostasis and suggest that topical MR blockade could limit glucocorticoid-induced epidermal atrophy. PMID:25668238

  8. Limitations in the process of transcription and translation inhibit recombinant human chorionic gonadotropin expression in CHO cells.

    PubMed

    Liu, Yang; Yi, Xiaoping; Zhuang, Yingping; Zhang, Siliang

    2015-06-20

    Human chorionic gonadotropin (hCG) is a glycoprotein hormone that exists as a heterodimer with a ? subunit and ? subunit assembled together with disulfide bridges. This hormone plays an important role in the detection of ovulation induction and in the treatment of certain diseases that cause female infertility. The effects of transcription, subunit expression, assembling and secretion on recombinant hCG expression in CHO cells were studied using stable high-producing and low-producing cell lines generated by the FLP-In™ system. The results indicated that the mRNA and polypeptide levels of the ? subunit were always higher than those of the ? subunit. Further study confirmed that the differences were caused by the transcription rate rather than by mRNA stability. In the high-producing cell lines, there was obvious transcription level limitation of the ? subunit in contrast to the ? subunit. In addition, there was obvious limitation of the synthetic steps from mRNA to polypeptide for both the ? subunit and the ? subunit, especially the ? subunit. Significant limitations of the assembly and secretion levels were not observed in this research. This study presents a research methodology for double subunit protein expression and provides valuable evidence for the enhancement of recombinant hCG productivity. PMID:25529346

  9. [Global public health: international health is tested to its limits by the human influenza A epidemic].

    PubMed

    Franco-Giraldo, Alvaro; Alvarez-Dardet, Carlos

    2009-06-01

    This article comes from the intense international pressure that follows a near-catastrophy, such as the human influenza A H1N1 epidemic, and the limited resources for confronting such events. The analysis covers prevailing 20th century trends in the international public health arena and the change-induced challenges brought on by globalization, the transition set in motion by what has been deemed the "new" international public health and an ever-increasing focus on global health, in the context of an international scenario of shifting risks and opportunities and a growing number of multinational players. Global public health is defined as a public right, based on a new appreciation of the public, a new paradigm centered on human rights, and altruistic philosophy, politics, and ethics that undergird the changes in international public health on at least three fronts: redefining its theoretical foundation, improving world health, and renewing the international public health system, all of which is the byproduct of a new form of governance. A new world health system, directed by new global public institutions, would aim to make public health a global public right and face a variety of staggering challenges, such as working on public policy management on a global scale, renewing and democratizing the current global governing structure, and conquering the limits and weaknesses witnessed by international health. PMID:19695150

  10. The limits for detection of activated caspases of spermatozoa by western blot in human semen.

    PubMed

    Brugnon, F; Pons-Rejraji, H; Artonne, C; Janny, L; Grizard, G

    2012-08-01

    Detection of activated caspases of spermatozoa could be helpful to evaluate male infertility. Although western blot is validated as a highly specific method to detect the proteins extracted from cells, the ability of this technique to detect activated sperm caspases in human semen may be limited. Indeed, round cells, which potentially contain some activated caspases, may be present in semen and interfere with the detection of activated sperm caspases. Moreover, it is necessary to evaluate the minimum amount of spermatozoa necessary to optimise the detection of activated caspases in semen samples. Our results showed that interference due to round cells contained in semen with activated caspase-3 requires separation of spermatozoa by density migration. This sperm preparation selects a mature sperm population that does not reflect the whole sperm population, and in infertile men with oligoasthenoteratozoospermia, the amount of spermatozoa thus selected is usually low. Moreover, the western blot technique's low detection sensitivity and the low level of caspase enzyme activity in human spermatozoa for activated caspase-3, -8 and -9 mean that large quantities of spermatozoa are needed to detect the expression of the activated caspases. These limitations prevent this method being used for routine analysis in clinical practice. PMID:22292703

  11. Hydration studies of human finger nails

    Microsoft Academic Search

    Benjamin Schulz; Danny Chan; Michael Ruebhausen; Roger Wepf; Sonja Wessel; Stefanie Williams

    2002-01-01

    We investigate the complex refractive index hatn = n+ik of human fingernails by means of spectral-resolved ellipsometry (325 nm - 790 nm), using a beam focussed to a spot diameter of 200 mum. Using an effective medium approximation, we can derive the water content of the nail from the measured hatn. In particular, we study the hydration\\/dehydration behaviour of the

  12. Human Challenge Pilot Study with Cyclospora cayetanensis

    PubMed Central

    Eberhard, Mark L.; Seed, John R.; Weber, David J.; Won, Kimberly Y.; Nace, Eva K.; Moe, Christine L.

    2004-01-01

    We describe a pilot study that attempted to infect human volunteers with Cyclospora cayetanensis. Seven healthy volunteers ingested an inoculum of Cyclospora oocysts (approximately 200–49,000 oocysts). The volunteers did not experience symptoms of gastroenteritis, and no oocysts were detected in any stool samples during the 16 weeks volunteers were monitored. PMID:15200870

  13. Human challenge pilot study with Cyclospora cayetanensis.

    PubMed

    Alfano-Sobsey, Edith M; Eberhard, Mark L; Seed, John R; Weber, David J; Won, Kimberly Y; Nace, Eva K; Moe, Christine L

    2004-04-01

    We describe a pilot study that attempted to infect human volunteers with Cyclospora cayetanensis. Seven healthy volunteers ingested an inoculum of Cyclospora oocysts (approximately 200-49,000 oocysts). The volunteers did not experience symptoms of gastroenteritis, and no oocysts were detected in any stool samples during the 16 weeks volunteers were monitored. PMID:15200870

  14. Genomic approaches to studying the human microbiota

    PubMed Central

    Weinstock, George M.

    2013-01-01

    The human body is colonized by a vast array of microbes, which form communities of bacteria, viruses and microbial eukaryotes that are specific to each anatomical environment. Every community must be studied as a whole because many organisms have never been cultured independently, and this poses formidable challenges. The advent of next-generation DNA sequencing has allowed more sophisticated analysis and sampling of these complex systems by culture-independent methods. These methods are revealing differences in community structure between anatomical sites, between individuals, and between healthy and diseased states, and are transforming our view of human biology. PMID:22972298

  15. Limits of Human Performance. Annual Meeting (56th, Eugene, Oregon, July 19-26, 1984). American Academy of Physical Education Papers, No. 18.

    ERIC Educational Resources Information Center

    Clarke, David H., Ed.; Eckert, Helen M., Ed.

    The following papers are included in this collection: (1) "The Scientific Study of Athletes and Athletics" (Henry J. Montoye); (2) "The Limits of Human Performance" (David H. Clarke); (3) "Observations of Extraordinary Performances in an Extreme Environment and in a Training Environment" (E.R. Buskirk); (4) "Metabolic Requirements of Distance…

  16. Stimulators of Mineralization Limit the Invasive Phenotype of Human Osteosarcoma Cells by a Mechanism Involving Impaired Invadopodia Formation

    PubMed Central

    Cmoch, Anna; Podszywalow-Bartnicka, Paulina; Palczewska, Malgorzata; Piwocka, Katarzyna; Groves, Patrick; Pikula, Slawomir

    2014-01-01

    Background Osteosarcoma (OS) is a highly aggressive bone cancer affecting children and young adults. Growing evidence connects the invasive potential of OS cells with their ability to form invadopodia (structures specialized in extracellular matrix proteolysis). Results In this study, we tested the hypothesis that commonly used in vitro stimulators of mineralization limit the invadopodia formation in OS cells. Here we examined the invasive potential of human osteoblast-like cells (Saos-2) and osteolytic-like (143B) OS cells treated with the stimulators of mineralization (ascorbic acid and B-glycerophosphate) and observed a significant difference in response of the tested cells to the treatment. In contrast to 143B cells, osteoblast-like cells developed a mineralization phenotype that was accompanied by a decreased proliferation rate, prolongation of the cell cycle progression and apoptosis. On the other hand, stimulators of mineralization limited osteolytic-like OS cell invasiveness into collagen matrix. We are the first to evidence the ability of 143B cells to degrade extracellular matrix to be driven by invadopodia. Herein, we show that this ability of osteolytic-like cells in vitro is limited by stimulators of mineralization. Conclusions Our study demonstrates that mineralization competency determines the invasive potential of cancer cells. A better understanding of the molecular mechanisms by which stimulators of mineralization regulate and execute invadopodia formation would reveal novel clinical targets for treating osteosarcoma. PMID:25314307

  17. To define the congruence of human population distribution and P. falciparum transmission we used spatially linked databases of human population, limits of malaria

    E-print Network

    Cai, Long

    spatially linked databases of human population, limits of malaria risk and malaria endemicity within defined the spatial extent of P. falciparum risk by using the mapped global limits of malaria risk on the only available global map of malaria endemicity developed in 1968 (refs 6, 7). This map was part

  18. Parasites of importance for human health in Nigerian dogs: high prevalence and limited knowledge of pet owners

    PubMed Central

    Ugbomoiko, Uade Samuel; Ariza, Liana; Heukelbach, Jorg

    2008-01-01

    Background Dogs are the most common pet animals worldwide. They may harbour a wide range of parasites with zoonotic potential, thus causing a health risk to humans. In Nigeria, epidemiological knowledge on these parasites is limited. Methods In a community-based study, we examined 396 dogs in urban and rural areas of Ilorin (Kwara State, Central Nigeria) for ectoparasites and intestinal helminths. In addition, a questionnaire regarding knowledge and practices was applied to pet owners. Results Nine ectoparasite species belonging to four taxa and six intestinal helminth species were identified: fleas (Ctenocephalides canis, Pulex irritans, Tunga penetrans), mites (Demodex canis, Otodectes sp., Sarcoptes scabiei var. canis), ticks (Rhipicephalus sanguineus, Ixodes sp.), and lice (Trichodectes canis); and Toxocara canis, Ancylostoma sp., Trichuris vulpis, Dipylidium caninum, Taenidae and Strongyloides sp. Overall prevalence of ectoparasites was 60.4% and of intestinal helminths 68.4%. The occurrence of C. canis, R. sanguineus, T. canis, Ancylostoma sp. and T. vulpis was most common (prevalence 14.4% to 41.7%). Prevalence patterns in helminths were age-dependent, with T. canis showing a decreasing prevalence with age of host, and a reverse trend in other parasite species. Knowledge regarding zoonoses was very limited and the diseases not considered a major health problem. Treatment with antiparasitic drugs was more frequent in urban areas. Conclusion Parasites of importance for human health were highly prevalent in Nigerian dogs. Interventions should include health education provided to dog owners and the establishment of a program focusing on zoonotic diseases. PMID:19068110

  19. A PILOT STUDY TO COMPARE MICROBIAL AND CHEMICAL INDICATORS OF HUMAN FECAL CONTAMINATION IN WATER

    EPA Science Inventory

    Limitations exist in applying traditional microbial methods for the detection of human fecal contamination of water. A pilot study was undertaken to compare the microbial and chemical indicators of human fecal contamination of water. Sixty-four water samples were collected in O...

  20. Nutrient Limitation Governs Staphylococcus aureus Metabolism and Niche Adaptation in the Human Nose

    PubMed Central

    Krismer, Bernhard; Liebeke, Manuel; Janek, Daniela; Nega, Mulugeta; Rautenberg, Maren; Hornig, Gabriele; Unger, Clemens; Weidenmaier, Christopher; Lalk, Michael; Peschel, Andreas

    2014-01-01

    Colonization of the human nose by Staphylococcus aureus in one-third of the population represents a major risk factor for invasive infections. The basis for adaptation of S. aureus to this specific habitat and reasons for the human predisposition to become colonized have remained largely unknown. Human nasal secretions were analyzed by metabolomics and found to contain potential nutrients in rather low amounts. No significant differences were found between S. aureus carriers and non-carriers, indicating that carriage is not associated with individual differences in nutrient supply. A synthetic nasal medium (SNM3) was composed based on the metabolomics data that permits consistent growth of S. aureus isolates. Key genes were expressed in SNM3 in a similar way as in the human nose, indicating that SNM3 represents a suitable surrogate environment for in vitro simulation studies. While the majority of S. aureus strains grew well in SNM3, most of the tested coagulase-negative staphylococci (CoNS) had major problems to multiply in SNM3 supporting the notion that CoNS are less well adapted to the nose and colonize preferentially the human skin. Global gene expression analysis revealed that, during growth in SNM3, S. aureus depends heavily on de novo synthesis of methionine. Accordingly, the methionine-biosynthesis enzyme cysteine-?-synthase (MetI) was indispensable for growth in SNM3, and the MetI inhibitor DL-propargylglycine inhibited S. aureus growth in SNM3 but not in the presence of methionine. Of note, metI was strongly up-regulated by S. aureus in human noses, and metI mutants were strongly abrogated in their capacity to colonize the noses of cotton rats. These findings indicate that the methionine biosynthetic pathway may include promising antimicrobial targets that have previously remained unrecognized. Hence, exploring the environmental conditions facultative pathogens are exposed to during colonization can be useful for understanding niche adaptation and identifying targets for new antimicrobial strategies. PMID:24453967

  1. Feasibility study on superconducting fault current limiting transformer (SFCLT)

    NASA Astrophysics Data System (ADS)

    Hayakawa, N.; Chigusa, S.; Kashima, N.; Nagaya, S.; Okubo, H.

    2000-04-01

    This paper proposes a "superconducting fault current limiting transformer (SFCLT)" with functions of both superconducting fault current limiters and superconducting transformers. Concepts of the SFCLT are as follows: (1) When a fault occurs in a power system, the SFCLT acts as a fault current limiter with limiting impedance due to quench of the SFCLT windings, which improves the transient stability of the power system. (2) In the normal condition, the SFCLT behaves as a transformer with lower leakage impedance, which increases the static stability and the transmission capacity of the power system. (3) The limiting and leakage impedance of the SFCLT can simultaneously be optimized in the power system. Electro-magnetic transients program (EMTP) analyses revealed that the SFCLT could exhibit the multifunction of fault current limitation and power system stability improvement in a simplified model system.

  2. On the performance limits for Si MOSFETs: a theoretical study

    Microsoft Academic Search

    Farzin Assad; Zhibin Ren; Dragica Vasileska; Supriyo Datta; Mark Lundstrom

    2000-01-01

    Performance limits of silicon MOSFETs are examined by a simple analytical theory augmented by self-consistent Schrodinger-Poisson simulations. The on-current, transconductance, and drain-to-source resistance in the ballistic limit (which corresponds to the channel length approaching zero) are examined. The ballistic transconductance in the limit that the oxide thickness approaches zero is also examined. The results show that as the channel length

  3. A limitation of the method for siRNA delivery into primary human cytotrophoblast cells.

    PubMed

    Desforges, M; Westwood, M

    2011-02-01

    Transfection using cationic lipid reagents such as DharmaFECT2 is an efficient tool for introducing siRNA into primary human cytotrophoblast cells. However, we now report a limitation to the use of this method as the concentration of DharamFECT2 needed for effective siRNA delivery causes ligand-independent activation of the insulin/insulin-like growth factor (IGF) receptor and consequently, functional resistance to cytotrophoblast stimulation by these two hormones. We therefore advise researchers against the use of this method of transfection when investigating the mechanisms by which insulin/IGF, and potentially other hormones that exert their effects through kinase signalling molecules, influence cytotrophoblast cell function. PMID:21146210

  4. Human behavioral flexibility: A psychogenetic study

    Microsoft Academic Search

    V. M. Rusalov; S. D. Biryukov

    1993-01-01

    Forty-seven two-children families from Moscow were used in a study to assess genetic determination of behavior flexibility, which was measured by eight laboratory tests. Flexibility is regarded as a temperament trait. There was no age- or sex-specific differentiation of human behavioral flexibility. Genetic determination of indices was used as a criterion for construct validization of flexibility tests. Factor analysis produced

  5. Monoamine oxidase: Radiotracer chemistry and human studies

    DOE PAGESBeta

    Fowler, Joanna S.; Logan, Jean; Shumay, Elena; Alia-Klein, Nelly; Wang, Gene-Jack; Volkow, Nora D.

    2015-03-01

    Monoamine oxidase (MAO) oxidizes amines from both endogenous and exogenous sources thereby regulating the concentration of neurotransmitter amines such as serot onin, norepinephrine and dopamine as well as many xenobiotics. MAO inhibitor drugs are used in the treatment of Parkinson’s disease and in depression stimulating the development of radiotracer tools to probe the role of MAO in normal human biology and in disease. Over the past 30 since the first radiotracers were developed and the first PET images of MAO in humans were carried out, PET studies of brain MAO in healthy volunteers and in patients have identified different variablesmore »which have contributed to different MAO levels in brain and in peripheral organs. MAO radiotracers and PET have also been used to study the current and developing MAO inhibitor drugs including the selection of doses for clinical trials. In this article, we describe (1) the development of MAO radiotracers; (2) human studies including the relationship of brain MAO levels to genotype, personality, neurological and psychiatric disorders; (3) examples of the use of MAO radiotracers in drug research and development. We will conclude with outstanding needs to improve the radiotracers which are currently used and possible new applications.« less

  6. Monoamine oxidase: Radiotracer chemistry and human studies

    DOE PAGESBeta

    Fowler, Joanna S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Logan, Jean [New York Univ., Langone Medical Center, New York, NY (United States); Shumay, Elena [National Inst. on Alcohol Abuse and Alcoholism, National Inst. of Health, Betheseda, MD (United States); Alia-Klein, Nelly [Mount Sinai School of Medicine, New York, NY (United States); Wang, Gene-Jack [National Inst. on Alcohol Abuse and Alcoholism, National Inst. of Health, Betheseda, MD (United States); Volkow, Nora D. [National Inst. on Alcohol Abuse and Alcoholism, National Inst. of Health, Betheseda, MD (United States); National Inst. on Drug Abuse, National Inst. of Health, Bethesda, MD (United States)

    2015-03-01

    Monoamine oxidase (MAO) oxidizes amines from both endogenous and exogenous sources thereby regulating the concentration of neurotransmitter amines such as serot onin, norepinephrine and dopamine as well as many xenobiotics. MAO inhibitor drugs are used in the treatment of Parkinson’s disease and in depression stimulating the development of radiotracer tools to probe the role of MAO in normal human biology and in disease. Over the past 30 since the first radiotracers were developed and the first PET images of MAO in humans were carried out, PET studies of brain MAO in healthy volunteers and in patients have identified different variables which have contributed to different MAO levels in brain and in peripheral organs. MAO radiotracers and PET have also been used to study the current and developing MAO inhibitor drugs including the selection of doses for clinical trials. In this article, we describe (1) the development of MAO radiotracers; (2) human studies including the relationship of brain MAO levels to genotype, personality, neurological and psychiatric disorders; (3) examples of the use of MAO radiotracers in drug research and development. We will conclude with outstanding needs to improve the radiotracers which are currently used and possible new applications.

  7. Innovation-diffusion: a geographical study of the transition of family limitation practice in Taiwan.

    PubMed

    Ting, T Y

    1984-09-01

    This paper uses map analysis to study the transition of family limitation practice in Taiwan between 1961-80. The innovation-diffusion perspective emphasizes that birth control, particularly contraception, is a recent innovation and is essentially new in human culture. The innovation-diffusion theory assumes that the decline of fertility began in a setting where there was no, or at most very limited, previous practice of birth control. The theory emphasizes the importance of the spread of information. It also assumes that innovation starts in metropolitan centers, diffuses to other urban places with some delay, and penetrates to rural areas still later. Innovation behavior also diffuses from 1 area to another which is culturally and linguistically similar. Although there was some urban to rural diffusion from the Taiwan family planning program, the government supported program provided services more evenly between urban and rural areas, thus somewhat limiting the diffusion effect from the program. For the diffusion of family practice in Taiwan, it is expected that the availability of of information about and means of family limitation practice may effect the rate of the increase of small m values -- an index of family limitation -- in an area. The case study of Pingtung county shows that the demand-side diffusion from urban to rural areas was important in the earlier decade of the transition of family plimitation practice, but distance from urban center was less important as practice became more uniform through diffusion. Ethnicity, whether or not the township was dominated by Hakka or Fukienese, also seems to have played an important role in determining the pace at which the local residents adopted family practice limitation. Hakka townships seem to have adopted family limitation practice more slowly than Fukienese townships about the same distance from the urban center. The map analysis of Pingtung county provides descriptive evidence to support the diffusion of family limitation from urban centers to distant areas, while ethnic variables like Hakka population tend to delay the adoption of family limitation practice. In general, the urban center had higher m values than the surrounding rural areas in Pingtung county and for areas other than the urban center the the level of m values is a negative function of the distance to the urban center. PMID:12266924

  8. Human studies of cannabinoids and medicinal cannabis.

    PubMed

    Robson, P

    2005-01-01

    Cannabis has been known as a medicine for several thousand years across many cultures. It reached a position of prominence within Western medicine in the nineteenth century but became mired in disrepute and legal controls early in the twentieth century. Despite unremitting world-wide suppression, recreational cannabis exploded into popular culture in the 1960s and has remained easily obtainable on the black market in most countries ever since. This ready availability has allowed many thousands of patients to rediscover the apparent power of the drug to alleviate symptoms of some of the most cruel and refractory diseases known to humankind. Pioneering clinical research in the last quarter of the twentieth century has given some support to these anecdotal reports, but the methodological challenges to human research involving a pariah drug are formidable. Studies have tended to be small, imperfectly controlled, and have often incorporated unsatisfactory synthetic cannabinoid analogues or smoked herbal material of uncertain composition and irregular bioavailability. As a result, the scientific evaluation of medicinal cannabis in humans is still in its infancy. New possibilities in human research have been opened up by the discovery of the endocannabinoid system, a rapidly expanding knowledge of cannabinoid pharmacology, and a more sympathetic political environment in several countries. More and more scientists and clinicians are becoming interested in exploring the potential of cannabis-based medicines. Future targets will extend beyond symptom relief into disease modification, and already cannabinoids seem to offer particular promise in the treatment of certain inflammatory and neurodegenerative conditions. This chapter will begin with an outline of the development and current status of legal controls pertaining to cannabis, following which the existing human research will be reviewed. Some key safety issues will then be considered, and the chapter will conclude with some suggestions as to future directions for human research. PMID:16596794

  9. 47 CFR 5.93 - Limited market studies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...licensee is responsible for informing anyone participating in the experiment that the service or device is granted under an experimental...is strictly temporary. (c) The size and scope of the experiment are subject to limitations as the Commission shall...

  10. 47 CFR 5.93 - Limited market studies.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...licensee is responsible for informing anyone participating in the experiment that the service or device is granted under an experimental...is strictly temporary. (c) The size and scope of the experiment are subject to limitations as the Commission shall...

  11. 47 CFR 5.93 - Limited market studies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...licensee is responsible for informing anyone participating in the experiment that the service or device is granted under an experimental...is strictly temporary. (c) The size and scope of the experiment are subject to limitations as the Commission shall...

  12. The Human Bitumen Study: executive summary.

    PubMed

    Raulf-Heimsoth, Monika; Pesch, Beate; Rühl, Reinhold; Brüning, Thomas

    2011-06-01

    Bitumen has attracted attention from the scientific community and regulating agencies. The debate on health effects of exposure to vapours and aerosols of bitumen during the hot application of bitumen ranges from respiratory and neurological effects to carcinogenicity. In 2000, the German Hazardous Substances Committee (AGS), in collaboration with the German Bitumen Forum, initiated the examination of a group of mastic asphalt workers and a same number of construction workers without exposure bitumen using a cross-shift design. The study was then extended to the Human Bitumen Study, and the recruitment was finished in 2008 after examination of 500 workers on 80 construction sites. Three hundred and twenty workers exposed to vapours and aerosols of bitumen at high processing temperatures and 118 workers at outdoor construction sites were included. In the Human Bitumen Study external exposure to vapours and aerosols of bitumen, internal exposure to PAH by analysing urinary 1-hydroxypyrene, the sum of hydroxyphenanthrenes and the sum of 1- and 2-hydroxynaphthalenes, irritative effects in the upper and lower airways and genotoxic effects in blood cells were investigated. The study turned out to be one of the largest investigations of workers exposed to vapours and aerosols of bitumen under current exposure conditions. The present paper summarizes its background and main topics. PMID:21369765

  13. Bioavailability of tocotrienols: evidence in human studies.

    PubMed

    Fu, Ju-Yen; Che, Hui-Ling; Tan, Doryn Meam-Yee; Teng, Kim-Tiu

    2014-01-01

    As a minor component of vitamin E, tocotrienols were evident in exhibiting biological activities such as neuroprotection, radio-protection, anti-cancer, anti-inflammatory and lipid lowering properties which are not shared by tocopherols. However, available data on the therapeutic window of tocotrienols remains controversial. It is important to understand the absorption and bioavailability mechanisms before conducting in-depth investigations into the therapeutic efficacy of tocotrienols in humans. In this review, we updated current evidence on the bioavailability of tocotrienols from human studies. Available data from five studies suggested that tocotrienols may reach its target destination through an alternative pathway despite its low affinity for ?-tocopherol transfer protein. This was evident when studies reported considerable amount of tocotrienols detected in HDL particles and adipose tissues after oral consumption. Besides, plasma concentrations of tocotrienols were shown to be higher when administered with food while self-emulsifying preparation of tocotrienols was shown to enhance the absorption of tocotrienols. Nevertheless, mixed results were observed based on the outcome from 24 clinical studies, focusing on the dosages, study populations and formulations used. This may be due to the variation of compositions and dosages of tocotrienols used, suggesting a need to understand the formulation of tocotrienols in the study design. Essentially, implementation of a control diet such as AHA Step 1 diet may influence the study outcomes, especially in hypercholesterolemic subjects when lipid profile might be modified due to synergistic interaction between tocotrienols and control diet. We also found that the bioavailability of tocotrienols were inconsistent in different target populations, from healthy subjects to smokers and diseased patients. In this review, the effect of dosage, composition and formulation of tocotrienols as well as study populations on the bioavailability of tocotrienols will be discussed. PMID:24410975

  14. Factors limiting adenovirus-mediated gene transfer into human lung and pancreatic cancer cell lines.

    PubMed

    Pearson, A S; Koch, P E; Atkinson, N; Xiong, M; Finberg, R W; Roth, J A; Fang, B

    1999-12-01

    Adenoviral vectors are a widely used means of gene transfer. However, transgene expression after adenoviral administration varies among different carcinoma cell lines. We hypothesized that this variation is attributable, in part, to the presence of cell surface molecules involved in adenoviral infection. To test this, we first assessed adenovirus-mediated transgene expression in four human lung carcinoma cell lines and four human pancreatic carcinoma cell lines in terms of luciferase activities and found it to vary from 4.8 x 10(4) to 6.1 x 10(7) relative light units/microg of protein. Then, to determine whether the molecules involved in the entry of adenovirus into host cells were responsible for this variation, we evaluated the expression of alpha(v)beta5, alpha(v), beta3, alpha5, and beta1 integrins and that of coxsackievirus and adenovirus receptor (CAR) in these cell lines. Statistical analysis revealed that the levels of beta3 were associated with the levels of transgene expression. Blocking analysis showed that adenovirus-mediated gene transfer could be blocked by antibodies against these six molecules but not by the antibodies against alpha2 or alpha3 integrins, thus suggesting that the integrins alphavbeta5, alpha(v), beta3, alpha5, and beta1 and CAR molecules could limit adenovirus-mediated gene transfer when their levels fell below a certain threshold. Furthermore, cells expressing low levels of beta3 and resistant to conventional adenoviral vectors were susceptible to a vector containing the heparin-binding domain in its fiber, thus suggesting that redirecting vectors to receptors other than CAR may bypass the integrin pathway. These findings may have implications for improving the efficiency of adenovirus-mediated gene transfer and developing novel adenoviral vectors. PMID:10632362

  15. Feasibility study of astronaut standardized career dose limits in LEO and the outlook for BLEO

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, Susan; Bhardwaj, A.; Ferrari, Franco; Kuznetsov, Nikolay; Lal, A. K.; Li, Yinghui; Nagamatsu, Aiko; Nymmik, Rikho; Panasyuk, Michael; Petrov, Vladislav; Reitz, Guenther; Pinsky, Lawrence; Muszaphar Shukor, Sheikh; Singhvi, A. K.; Straube, Ulrich; Tomi, Leena; Townsend, Lawrence

    2014-11-01

    Cosmic Study Group SG 3.19/1.10 was established in February 2013 under the aegis of the International Academy of Astronautics to consider and compare the dose limits adopted by various space agencies for astronauts in Low Earth Orbit. A preliminary definition of the limits that might later be adopted by crews exploring Beyond Low Earth Orbit was, in addition, to be made. The present paper presents preliminary results of the study reported at a Symposium held in Turin by the Academy in July 2013. First, an account is provided of exposure limits assigned by various partner space agencies to those of their astronauts that work aboard the International Space Station. Then, gaps in the scientific and technical information required to safely implement human missions beyond the shielding provided by the geomagnetic field (to the Moon, Mars and beyond) are identified. Among many recommendations for actions to mitigate the health risks potentially posed to personnel Beyond Low Earth Orbit is the development of a preliminary concept for a Human Space Awareness System to: provide for crewed missions the means of prompt onboard detection of the ambient arrival of hazardous particles; develop a strategy for the implementation of onboard responses to hazardous radiation levels; support modeling/model validation that would enable reliable predictions to be made of the arrival of hazardous radiation at a distant spacecraft; provide for the timely transmission of particle alerts to a distant crewed vehicle at an emergency frequency using suitably located support spacecraft. Implementation of the various recommendations of the study can be realized based on a two pronged strategy whereby Space Agencies/Space Companies/Private Entrepreneurial Organizations etc. address the mastering of required key technologies (e.g. fast transportation; customized spacecraft design) while the International Academy of Astronautics, in a role of handling global international co-operation, organizes complementary studies aimed at harnessing the strengths and facilities of emerging nations in investigating/solving related problems (e.g. advanced space radiation modeling/model validation; predicting the arrivals of Solar Energetic Particles and shocks at a distant spacecraft). Ongoing progress in pursuing these complementary parallel programs could be jointly reviewed bi-annually by the Space Agencies and the International Academy of Astronautics so as to maintain momentum and direction in globally progressing towards feasible human exploration of interplanetary space.

  16. Meta-Analytic Approaches for Multistressor Dose-Response Function Development: Strengths, Limitations, and Case Studies.

    PubMed

    Levy, Jonathan I; Fabian, M Patricia; Peters, Junenette L

    2015-06-01

    For many policy analyses, including but not limited to cumulative risk assessments, it is important to characterize the individual and joint health effects of multiple stressors. With an increasing focus on psychosocial and other nonchemical stressors, this often includes epidemiological meta-analysis. Meta-analysis has limitations if epidemiological studies do not include all of the stressors of interest or do not provide multivariable outputs in a format necessary for risk assessment. Given these limitations, novel analytical methods are often needed to synthesize the published literature or to build upon available evidence. In this article, we discuss three recent case studies that highlight the strengths and limitations of meta-analytic approaches and other research synthesis techniques for human health risk assessment applications. First, a literature-based meta-analysis within a risk assessment context informed the design of a new epidemiological investigation of the differential toxicity of fine particulate matter constituents. Second, a literature synthesis for an effects-based cumulative risk assessment of hypertension risk factors led to a decision to develop new epidemiological associations using structural equation modeling. Third, discrete event simulation modeling was used to simulate the impact of changes in the built environment on environmental exposures and associated asthma outcomes, linking literature meta-analyses for key associations with a simulation model to synthesize all of the model components. These case studies emphasize the importance of conducting epidemiology with a risk assessment application in mind, the need for interdisciplinary collaboration, and the value of advanced analytical methods to synthesize epidemiological and other evidence for risk assessment applications. PMID:24724810

  17. Metabolic Phenotyping Guidelines: studying eating behaviour in humans.

    PubMed

    Gibbons, Catherine; Finlayson, Graham; Dalton, Michelle; Caudwell, Phillipa; Blundell, John E

    2014-08-01

    The study of human appetite and eating behaviour has become increasingly important in recent years due to the rise in body weight dysregulation through both obesity and eating disorders. Adequate control over appetite is paramount for the control of body weight and in order to understand appetite, it is necessary to measure eating behaviour accurately. So far, research in this field has revealed that no single experimental design can answer all research questions. Each research question posed will require a specific study design that will limit the findings of that study to those particular conditions. For example, choices will be made among the use of laboratory or free-living studies, time period for examination, specific measurement techniques and investigative methodologies employed. It is important that these represent informed decisions about what design and which methodology will provide the most meaningful outcomes. This review will examine some of the 'gold standard' study designs and methodologies currently employed in the study of human appetite and eating behaviour. PMID:25052364

  18. A Review of the Empirical Studies of Computer Supported Human-to-Human Communication

    Microsoft Academic Search

    Masood Masoodian

    This paper presents a review of the empirical studies of human-to-human communication which have been carried out over the last three decades. Although this review is primarily concerned with the empirical studies of computer supported human-to-human communication, a number of studies dealing with group work in non-computer-based collaborative environments, which form the basis of many of the empirical studies of

  19. Staging small cell lung cancer: Veterans Administration Lung Study Group versus International Association for the Study of Lung Cancer—what limits limited disease?

    Microsoft Academic Search

    Patrick Micke; Andreas Faldum; Tsegay Metz; Kai-Michael Beeh; Fernando Bittinger; Jan-Georg Hengstler; Roland Buhl

    2002-01-01

    Small cell lung cancer (SCLC) is usually classified into a two-stage system, limited (LD) and extensive disease (ED). However, the criteria for these two categories remain controversial. The widely used Veterans Administration Lung Study Group (VALG) definition of LD includes patients with primary tumor and nodal involvement limited to one hemithorax. In contrast, the International Association for the Study of

  20. Drosophila melanogaster in the Study of Human Neurodegeneration

    PubMed Central

    Hirth, Frank

    2010-01-01

    Human neurodegenerative diseases are devastating illnesses that predominantly affect elderly people. The majority of the diseases are associated with pathogenic oligomers from misfolded proteins, eventually causing the formation of aggregates and the progressive loss of neurons in the brain and nervous system. Several of these proteinopathies are sporadic and the cause of pathogenesis remains elusive. Heritable forms are associated with genetic defects, suggesting that the affected protein is causally related to disease formation and/or progression. The limitations of human genetics, however, make it necessary to use model systems to analyse affected genes and pathways in more detail. During the last two decades, research using the genetically amenable fruitfly has established Drosophila melanogaster as a valuable model system in the study of human neurodegeneration. These studies offer reliable models for Alzheimer’s, Parkinson’s, and motor neuron diseases, as well as models for trinucleotide repeat expansion diseases, including ataxias and Huntington’s disease. As a result of these studies, several signalling pathways including phosphatidylinositol 3-kinase (PI3K)/Akt and target of rapamycin (TOR), c-Jun N-terminal kinase (JNK) and bone morphogenetic protein (BMP) signalling, have been shown to be deregulated in models of proteinopathies, suggesting that two or more initiating events may trigger disease formation in an age-related manner. Moreover, these studies also demonstrate that the fruitfly can be used to screen chemical compounds for their potential to prevent or ameliorate the disease, which in turn can directly guide clinical research and the development of novel therapeutic strategies for the treatment of human neurodegenerative diseases. PMID:20522007

  1. Background of Civil Defense and Current Damage Limiting Studies.

    ERIC Educational Resources Information Center

    Romm, Joseph

    A brief history of civil defense administration precedes analysis of nuclear attack conditions and the influence of protective measures. Damage limitation procedure is explained in terms of--(1) blast effects, (2) radiation doses, (3) geographical fallout distribution patterns, and (4) national shelter needs. Major concept emphasis relates to--(1)…

  2. Int. J. Human-Computer Studies 58 (2003) 483508 Human performance modeling in temporary

    E-print Network

    Wu, Changxu (Sean)

    2003-01-01

    Int. J. Human-Computer Studies 58 (2003) 483­508 Human performance modeling in temporary Psychology and Human Factors Laboratory, Institute of Psychology, Chinese Academy of Sciences, Beijing, PR Paper accepted for publication by Editor, B. Gaines Abstract Human performance in Chinese character

  3. Limiting the Scope of Needs Assessment Studies or (How We Learned to Set Limits--And Feel No Guilt).

    ERIC Educational Resources Information Center

    Eastmond, J. Nicholls, Jr.; And Others

    Needs assessment is an activity undertaken for planning purposes. It is important to define the limits of the study and design it on a scale appropriate to the entire planning process. This paper suggests that a needs assessment be structured into two phases. In the pre-assessment phase, a conceptual framework and well-defined exploratory…

  4. Challenges in the management of disseminated progressive histoplasmosis in human immunodeficiency virus-infected patients in resource-limited settings.

    PubMed

    Murphy, Richard A; Gounder, Lilishia; Manzini, Thandekile C; Ramdial, Pratistadevi K; Castilla, Carmen; Moosa, Mahomed-Yunus S

    2015-01-01

    The diagnosis of histoplasmosis in patients with human immunodeficiency virus in southern Africa is complicated by the nonspecific presentation of the disease in this patient group and the unavailability of sensitive diagnostics including antigen assays. Treatment options are also limited due to the unavailability of liposomal amphotericin and itraconazole, and the inability to perform therapeutic drug monitoring further confounds management. We present 3 clinical cases to illustrate the limits of diagnosis and management in the southern African context, and we highlight the need for additional diagnostic tools and treatment options in resource-limited settings. PMID:26034774

  5. Challenges in the Management of Disseminated Progressive Histoplasmosis in Human Immunodeficiency Virus-Infected Patients in Resource-Limited Settings

    PubMed Central

    Murphy, Richard A.; Gounder, Lilishia; Manzini, Thandekile C.; Ramdial, Pratistadevi K.; Castilla, Carmen; Moosa, Mahomed-Yunus S.

    2015-01-01

    The diagnosis of histoplasmosis in patients with human immunodeficiency virus in southern Africa is complicated by the nonspecific presentation of the disease in this patient group and the unavailability of sensitive diagnostics including antigen assays. Treatment options are also limited due to the unavailability of liposomal amphotericin and itraconazole, and the inability to perform therapeutic drug monitoring further confounds management. We present 3 clinical cases to illustrate the limits of diagnosis and management in the southern African context, and we highlight the need for additional diagnostic tools and treatment options in resource-limited settings.

  6. Limitations and Applications of ICA in Facial sEMG and Hand Gesture sEMG for Human Computer Interaction

    Microsoft Academic Search

    Ganesh R. Naik; Dinesh Kant Kumar; Sridhar Poosapadi Arjunan; Hans Weghorn; Marimuthu Palaniswami

    2007-01-01

    In the recent past, there has been an increasing trend of using Blind Signal Separation (BSS) or Independent Component Analysis (ICA) algorithm for bio medical data, especially in prosthesis and Human Computer Interaction (HCI) applications. This paper reviews the concept of BSS and demonstrates its usefulness and limitations in the context of surface electromyogram related to hand movements and vowel

  7. Beyond Bias? The Promise and Limits of Q Method in Human Geography

    Microsoft Academic Search

    Paul Robbins; Rob Krueger

    2000-01-01

    Q method is a quantitative technique for eliciting, evaluating, and comparing human subjectivity. We introduce the method here and evaluate its strengths and weaknesses, especially with regards to its incorporation into human geographic research. We conclude that Q method is particularly appropriate for human geographies informed by anti-essentialist notions of the subject and constructivist accounts of social and natural reality.

  8. Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans.

    PubMed

    Lerchl, Alexander; Klose, Melanie; Grote, Karen; Wilhelm, Adalbert F X; Spathmann, Oliver; Fiedler, Thomas; Streckert, Joachim; Hansen, Volkert; Clemens, Markus

    2015-04-17

    The vast majority of in vitro and in vivo studies did not find cancerogenic effects of exposure to electromagnetic fields (RF-EMF), i.e. emitted by mobile phones and base stations. Previously published results from a pilot study with carcinogen-treated mice, however, suggested tumor-promoting effects of RF-EMF (Tillmann et al., 2010). We have performed a replication study using higher numbers of animals per group and including two additional exposure levels (0 (sham), 0.04, 0.4 and 2 W/kg SAR). We could confirm and extend the originally reported findings. Numbers of tumors of the lungs and livers in exposed animals were significantly higher than in sham-exposed controls. In addition, lymphomas were also found to be significantly elevated by exposure. A clear dose-response effect is absent. We hypothesize that these tumor-promoting effects may be caused by metabolic changes due to exposure. Since many of the tumor-promoting effects in our study were seen at low to moderate exposure levels (0.04 and 0.4 W/kg SAR), thus well below exposure limits for the users of mobile phones, further studies are warranted to investigate the underlying mechanisms. Our findings may help to understand the repeatedly reported increased incidences of brain tumors in heavy users of mobile phones. PMID:25749340

  9. The dog as a model to study human epididymal function at a molecular level

    Microsoft Academic Search

    Christiane Kirchhoff

    2002-01-01

    Approaches to study human epididymal functions are limited. Therefore, suitable animal models are highly desirable, yet difficult to find among the few species studied on a molecular level to date. This review summarizes our progress in the development of the canine epididymis as an alternative model. Dogs are biomedically a key species because they are subject to many of the

  10. Hydration studies of human finger nails

    NASA Astrophysics Data System (ADS)

    Schulz, Benjamin; Chan, Danny; Ruebhausen, Michael; Wepf, Roger; Wessel, Sonja; Williams, Stefanie

    2002-03-01

    We investigate the complex refractive index hatn = n+ik of human fingernails by means of spectral-resolved ellipsometry (325 nm - 790 nm), using a beam focussed to a spot diameter of 200 ?m. Using an effective medium approximation, we can derive the water content of the nail from the measured hatn. In particular, we study the hydration/dehydration behaviour of the nails by observing the changes in the complex refractive index. Upon hydration by soaking the nail in water, we find that the time dependence of n is well described by K_0+K1 exp (-t / ?), with ? ? 5 min, while k is increasing. Furthermore, we find that the external hydration process seems to be only partially reversible.

  11. Metabolomic studies of human gastric cancer: Review

    PubMed Central

    Jayavelu, Naresh Doni; Bar, Nadav S

    2014-01-01

    Metabolomics is a field of study in systems biology that involves the identification and quantification of metabolites present in a biological system. Analyzing metabolic differences between unperturbed and perturbed networks, such as cancerous and non-cancerous samples, can provide insight into underlying disease pathology, disease prognosis and diagnosis. Despite the large number of review articles concerning metabolomics and its application in cancer research, biomarker and drug discovery, these reviews do not focus on a specific type of cancer. Metabolomics may provide biomarkers useful for identification of early stage gastric cancer, potentially addressing an important clinical need. Here, we present a short review on metabolomics as a tool for biomarker discovery in human gastric cancer, with a primary focus on its use as a predictor of anticancer drug chemosensitivity, diagnosis, prognosis, and metastasis. PMID:25009381

  12. Where to look: a study of human-robot engagement

    Microsoft Academic Search

    Candace L. Sidner; Cory D. Kidd; Christopher Lee; Neal Lesh

    2004-01-01

    This paper reports on a study of human subjects with a robot designed to mimic human conversational gaze behavior in collaborative conversation. The robot and the human subject together performed a demonstration of an invention created at our laboratory; the demonstration lasted 3 to 3.5 minutes. We briefly discuss the robot architecture and then focus the paper on a study

  13. Study of sound localization by owls and its relevance to humans.

    PubMed

    Konishi, M

    2000-08-01

    Human psychoacoustical studies have been the main sources of information from which the brain mechanisms of sound localization are inferred. The value of animal models would be limited, if humans and the animals did not share the same perceptual experience and the neural mechanisms for it. Barn owls and humans use the same method of computing interaural time differences for localization in the horizontal plane. The behavioral performance of owls and its neural bases are consistent with some of the theories developed for human sound localization. Neural theories of sound localization largely owe their origin to the study of sound localization by humans, even though little is known about the physiological properties of the human auditory system. One of these ideas is binaural cross-correlation which assumes that the human brain performs a process similar to mathematical cross-correlation to measure the interaural time difference for localization in the horizontal plane. The most complete set of neural evidence for this theory comes from the study of sound localization and its brain mechanisms in barn owls, although partial support is also available from studies on laboratory mammals. Animal models of human sensory perception make two implicit assumptions; animals and humans experience the same percept and the same neural mechanism underlies the creation of the percept. These assumptions are hard to prove for obvious reason. This article reviews several lines of evidence that similar neural mechanisms must underlie the perception of sound locations in humans and owls. PMID:10989338

  14. Flow motifs reveal limitations of the static framework to represent human interactions

    NASA Astrophysics Data System (ADS)

    Rocha, Luis E. C.; Blondel, Vincent D.

    2013-04-01

    Networks are commonly used to define underlying interaction structures where infections, information, or other quantities may spread. Although the standard approach has been to aggregate all links into a static structure, some studies have shown that the time order in which the links are established may alter the dynamics of spreading. In this paper, we study the impact of the time ordering in the limits of flow on various empirical temporal networks. By using a random walk dynamics, we estimate the flow on links and convert the original undirected network (temporal and static) into a directed flow network. We then introduce the concept of flow motifs and quantify the divergence in the representativity of motifs when using the temporal and static frameworks. We find that the regularity of contacts and persistence of vertices (common in email communication and face-to-face interactions) result on little differences in the limits of flow for both frameworks. On the other hand, in the case of communication within a dating site and of a sexual network, the flow between vertices changes significantly in the temporal framework such that the static approximation poorly represents the structure of contacts. We have also observed that cliques with 3 and 4 vertices containing only low-flow links are more represented than the same cliques with all high-flow links. The representativity of these low-flow cliques is higher in the temporal framework. Our results suggest that the flow between vertices connected in cliques depend on the topological context in which they are placed and in the time sequence in which the links are established. The structure of the clique alone does not completely characterize the potential of flow between the vertices.

  15. Humex, a study on the survivability and adaptation of humans to long-duration exploratory missions, part I: Lunar missions

    Microsoft Academic Search

    G. Horneck; R. Facius; M. Reichert; P. Rettberg; W. Seboldt; D. Manzey; B. Comet; A. Maillet; H. Preiss; L. Schauer; C. G. Dussap; L. Poughon; A. Belyavin; G. Reitz; C. Baumstark-Khan; R. Gerzer

    2003-01-01

    The European Space Agency has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis has been laid on human health and performance care as well as advanced life support developments including bioregenerative life support systems and environmental monitoring. The overall study goals were as follows: (i)

  16. Scientific limitations and ethical ramifications of a non-representative Human Genome Project: African American response

    Microsoft Academic Search

    Fatimah Jackson

    1998-01-01

    The Human Genome Project (HGP) represents a massive merging of science and technology in the name of all humanity. While the\\u000a disease aspects of HGP-generated data have received the greatest publicity and are the strongest rationale for the project,\\u000a it should be remembered that the HGP has, as its goal the sequencing of all 100,000 human genes and the accurate

  17. Study on Optical Filter Heating in Background Limited Detector Experiments

    NASA Astrophysics Data System (ADS)

    Bueno, J.; de Visser, P. J.; Doyle, S.; Baselmans, J. J. A.

    2014-09-01

    Cryogenic test setups with controlled stray light environments capable of reaching ultra-low radiative background levels are required to test far infrared (FIR) and submillimeter (sub-mm) wave radiation detectors for future space based observatories. In recent experiments (Nature Commun 5:3130, 2014), in which 1.54 THz radiation was coupled onto an antenna-coupled kinetic inductance detector (KID), we found a higher than expected optical loading. We show that this can be explained by assuming heating of the metal mesh IR filters and re-radiation onto the KID. Note that the total power from the cryogenic black body source used in the experiments (at T = - K) is much larger than the power inside the - THz band we use to calibrate our detector. The out-of-band radiation can have up to 5 orders of magnitude more power than inside the - THz band of interest. A strategy to mitigate the filter heating problem is presented, and when it is implemented, the validated upper limit for stray light at the detector level is down to few aW.

  18. On the limit of neural phase locking to fine structure in humans.

    PubMed

    Joris, Philip X; Verschooten, Eric

    2013-01-01

    The frequency extent over which temporal fine structure is available in the human auditory system has recently become a topic of much discussion. It is common, in both the physiological and psychophysical literature, to encounter the assumption that fine structure is available to humans up to about 5 kHz or even higher. We argue from existing physiological, anatomical, and behavioral data in animals, combined with behavioral and anatomical data in humans, that it is unlikely that the human central nervous system has access to fine structure above a few kHz. PMID:23716214

  19. AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Human exposure assessment studies require methods that are rapid, cost-effective and have a high sample through-put. The development of analytical methods for exposure studies should be based on specific information for individual studies. Human exposure studies suggest that di...

  20. Human Resources Data in System Design Trade Studies

    Microsoft Academic Search

    William B. Askren; Larry M. Lintz

    1975-01-01

    The system design trade study process was investigated to determine the feasibility of including human resources data. First, 61 completed trade studies from aeronautical, missile, and command and control systems were analyzed to determine the characteristics of trade studies. Then, four simulated trade studies containing engineering and human resources data and representing flight control and avionics subsystems were constructed for

  1. A Brief History of Soils and Human Health Studies

    NASA Astrophysics Data System (ADS)

    Brevik, Eric C.; Sauer, Thomas J.

    2013-04-01

    The idea that there are links between soils and human health is an ancient one. The Bible depicts Moses as understanding that fertile soil was essential to the well-being of his people in approximately 1400 B.C. as they entered Canaan, and in 400 B.C. Hippocrates provided a list of things that should be considered in a proper medical evaluation, including the ground. Moving into the 18th and 19th Centuries, some North American farmers have been documented as recognizing a link between soils and human vitality. However, the recognition of links between soils and human health by these early people was based on casual observations leading to logical conclusions rather than scientific investigation. In the 1900s the idea that soils influence human health gained considerable traction. At least three chapters in the 1938 USDA Yearbook of Agriculture included recognition of the importance of soil as the origin of many of the mineral elements necessary for human health and in the 1957 USDA Yearbook of Agriculture scientists realized that soils were not only important in the supply of essential nutrients, but that they could also supply toxic levels of elements to the human diet. The U.S. Department of Agriculture established the Plant, Soil and Nutrition Research Unit (PSNRU) on the Cornell University campus in 1940 with a mission to conduct research at the interface of human nutrition and agriculture to improve the nutritional quality and health-promoting properties of food crops. A major human health breakthrough in 1940 was the isolation of antibiotic compounds from soil organisms by the research group at Rutgers University lead by Selman Waksman. Soil microorganisms create antibiotic compounds in an effort to gain a competitive advantage in the soil ecosystem. Humans have been able to isolate those compounds and use them advantageously in the fight against bacterial infections. Waksman was awarded the Nobel Prize in Physiology or Medicine in 1952, the only soil scientist to date to be awarded a Nobel Prize. In the 1940s and 50s William Albrecht of the University of Missouri became interested in links between soils and human health, an interest that lead to the publication of several papers. Albrecht's works focused on links between soil fertility and dental health, with a particular focus on the relationships between soil fertility and dental cavities. However, Albrecht did extend the relationships between soil fertility and human health out to broader, more general health issues in some of his writings as well. Well-known figures such as Sir Albert Howard and J.I. Rodale also published works in the 1940s that included soils and human health components. Then André Voisin published "Soil, Grass, and Cancer" in 1959. Much of Voisin's work focused on nutrient content in soils, including both nutrient deficiencies and imbalances, and how that influences nutrient status in plants and animals that are in turn consumed by humans. Several health problems are discussed, including but not limited to birth defects, goiter, mental illness, diabetes, and cancer. Voisin concluded that the medical profession had largely ignored soils in their efforts to improve human health, but that soil science should be the foundation of preventative medicine. Soils and human health studies continued in the later part of the 20th Century. The health effects of exposures to radioactive elements in soils received considerable attention after the 1986 Chernobyl incident, however, even prior to Chernobyl radionuclides in the soil and how they may affect human health were receiving attention. Investigations into the effects of heavy metals in soils became a common theme as did organic chemicals in soils and the effects of trace elements on human health. Following up on the discovery of antibiotics, soil organisms received increased attention as they related to human health. By the end of the 1900s, M.A. Oliver (1997) noted that "… there is a dearth of quantitative information on the relations between elements in the soil and human health;

  2. Quantification of human motion: gait analysis—benefits and limitations to its application to clinical problems

    Microsoft Academic Search

    Sheldon R. Simon

    2004-01-01

    The technology supporting the analysis of human motion has advanced dramatically. Past decades of locomotion research have provided us with significant knowledge about the accuracy of tests performed, the understanding of the process of human locomotion, and how clinical testing can be used to evaluate medical disorders and affect their treatment. Gait analysis is now recognized as clinically useful and

  3. Study made of ductility limitations of aluminum-silicon alloys

    NASA Technical Reports Server (NTRS)

    Bailey, W. A.; Frederick, S. F.

    1967-01-01

    Study of the relation between microstructure and mechanical properties of aluminum-silicon alloys determines the cause of the variations in properties resulting from differences in solidification rate. It was found that variations in strength are a consequence of variations in ductility and that ductility is inversely proportional to dendrite cell size.

  4. Solution convergence study during launch phase using limited tracking data

    NASA Astrophysics Data System (ADS)

    Premkumar, R. I.

    Orbit determination accuracies during critical phases at launch, when data are available from only one station, can be enhanced using angle data with conventional Doppler and range data. A study performed on the forthcoming Japanese ETS-5 mission indicates that this requires correct handling of the angle biases. This was verified using actual tracking data received from the BS-2B launch.

  5. Egg Limitation in Parasitoids: A Review of the Evidence and a Case Study

    Microsoft Academic Search

    George E. Heimpel; Jay A. Rosenheim

    1998-01-01

    Life history theory predicts that a nontrivial proportion of parasitoids should exhaust their egg supply during their lifetime. We reviewed the literature on egg limitation in parasitoids and found partial support for this prediction. Most of the evidence in support of egg limitation is indirect and does not constitute absolute proof of egg limitation. However, a few direct studies in

  6. Human Motion in Cooperative Tasks: Moving Object Case Study

    E-print Network

    Paris-Sud XI, Université de

    Human Motion in Cooperative Tasks: Moving Object Case Study Sylvain Miossec AIST/CNRS JRL Email, for a pair of human operators, in moving a handle-shaped object between two predefined locations on a table of human haptics in physical cooperative tasks involving an object intermediary, which we term person

  7. Studies of human breast cancer metastasis using nude mice

    Microsoft Academic Search

    Janet E. Price; Ruo Dan Zhang

    1990-01-01

    Athymic nude mice have been used in recent years to study the biology of human tumors and to assess therapeutic responses in vivo rather than just in vitro. Some human tumors metastasize in nude mice, providing model systems for analyzing various aspects of the metastatic phenotype of human neoplasms. For breast carcinomas, however, the tumor-take rate of surgical specimens is

  8. Current humanized mouse models for studying human immunology and HIV1 immuno-pathogenesis

    Microsoft Academic Search

    LiGuo Zhang; Eric Meissner; JianZhu Chen; LiShan Su

    2010-01-01

    A robust animal model for “hypothesis-testing\\/mechanistic” research in human immunology and immuno-pathology should meet the\\u000a following criteria. First, it has well-studied hemato-lymphoid organs and target cells similar to those of humans. Second,\\u000a the human pathogens establish infection and lead to relevant diseases. Third, it is genetically inbred and can be manipulated\\u000a via genetic, immunological and pharmacological means. Many human-tropic pathogens

  9. Studying Human Dynamics Through Web Analytics

    NASA Astrophysics Data System (ADS)

    Ramasco, Jose; Goncalves, Bruno

    2008-03-01

    When Tim Berners Lee, a physicist at the European Center for Nuclear Research (CERN) first conceived the World Wide Web (WWW) in 1990 as a way to facilitate the sharing of scientific information and results among the centers different researchers and groups, even the most ingenious of science fiction writers could not have imagined the role it would come to play in the following decades. The increasing ubiquitousness of Internet access and the frequency with which people interact with it raise the possibility of using it to better observe, understand, and even monitor several aspects of human social behavior. Websites with large numbers of frequently returning users, such as search engines, company or university websites, are ideal for this task. The properly anonymized logs detailing the access history to Emory University's website is studied. We find that a small number of users is responsible for a finite fraction of the total activity. A saturation phenomenon is observed where, certain connections age, becoming less attractive to new activity over time. Finally, by measuring the average activity as a function of the day of the week, we find that productivity seems to be higher on Tuesdays and Wednesdays, with Sundays being the least active day.

  10. Use of human epidermal cells in the study of carcinogenesis

    Microsoft Academic Search

    Toshio Kuroki; Kazuhiro Chida; Jiro Hosomi; Seiji Kondo

    1989-01-01

    Because of the importance of human cells, particularly human epithelial cells, in cancer research, we have studied certain phases or events of carcinogenesis using human epidermal cells in primary culture. (1) We found that human epidermal cells are capable of metabolizing benzo(a)pyrene. Large inter-individual variations are found in the basal and induced arylhydrocarbon-hydroxylase activities. (2) UV-induced unscheduled DNA synthesis was

  11. John B. Watson and the study of human sexual behavior

    Microsoft Academic Search

    H. W. Magoun

    1981-01-01

    This article reviews the steps in John B. Watson's career from his initial experiments in rat learning, through studies of reflexes in newborn and infant children, to his exploration of adult human sexual behavior. The latter began with questionnaire studies of World War I films on sex hygiene. Watson was next reported to have engaged in laboratory studies of human

  12. Sex Without Friction: the Limits of Multi-Mediated Human Subjectivity in Cheang Shu Lea's Tech-Porn

    Microsoft Academic Search

    Jian Chen

    2010-01-01

    Sex Without Friction focuses on Cheang Shu Lea's science fiction porno I.K.U. (2000) as provocation to think through the limitations of social and cultural criticism that is premised on mediation. Directed by Taiwan-born digital nomad Cheang, multimedia film I.K.U. features a gender-morphing human clone, programmed to collect sexual experiences for the future mass production of sex simulation pills. I.K.U. positions

  13. Sex Without Friction: the Limits of Multi-Mediated Human Subjectivity in Cheang Shu Lea's Tech-Porn

    Microsoft Academic Search

    Jian Chen

    2010-01-01

    :Sex Without Friction focuses on Cheang Shu Lea's science fiction porno I.K.U. (2000) as provocation to think through the limitations of social and cultural criticism that is premised on mediation. Directed by Taiwan-born digital nomad Cheang, multimedia film I.K.U. features a gender-morphing human clone, programmed to collect sexual experiences for the future mass production of sex simulation pills. I.K.U. positions

  14. The limits of adaptation: humans and the predator-prey arms race.

    PubMed

    Vermeij, Geerat J

    2012-07-01

    In the history of life, species have adapted to their consumers by evolving a wide variety of defenses. By contrast, animal species harvested in the wild by humans have not adapted structurally. Nonhuman predators have high failure rates at one or more stages of an attack, indicating that victim species have spatial refuges or phenotypic defenses that permit further functional improvement. A new compilation confirms that species in the wild cannot achieve immunity from human predation with structural defenses. The only remaining options are to become undesirable or to live in or escape to places where harvesting by people is curtailed. Escalation between prey defenses and predators' weapons may be restricted under human dominance to interactions involving those low-level predators that have benefited from human overexploitation of top consumers. PMID:22759280

  15. Semen Quality and Human Fertility: A Prospective Study With Healthy Couples

    Microsoft Academic Search

    MICHAEL J. ZINAMAN; CHARLES C. BROWN; SHERRY G. SELEVAN; ERIC D. CLEGG

    2000-01-01

    Measures of semen quality are used as surrogate measures of male fertility in clinical andrology, reproductive toxicol- ogy, epidemiology, and risk assessment. However, only limited data are available to relate those measures to fertility. This prospective study with 210 reproductive-age couples was conducted to provide information on the value of semen quality measures for predicting human male fertility potential and

  16. Simulation study of PET detector limitations using continuous crystals.

    PubMed

    Cabello, Jorge; Etxebeste, Ane; Llosá, Gabriela; Ziegler, Sibylle I

    2015-05-01

    Continuous crystals can potentially obtain better intrinsic detector spatial resolution compared to pixelated crystals, additionally providing depth of interaction (DoI) information from the light distribution. To achieve high performance sophisticated interaction position estimation algorithms are required. There are a number of algorithms in the literature applied to different crystal dimensions and different photodetectors. However, the different crystal properties and photodetector array geometries have an impact on the algorithm performance. In this work we analysed, through Monte Carlo simulations, different combinations of realistic crystals and photodetector parameters to better understand their influence on the interaction position estimation accuracy, with special emphasis on the DoI. We used an interaction position estimation based on an analytical model for the present work. Different photodetector granulation schemes were investigated. The impact of the number of crystal faces readout by photodetectors was studied by simulating scenarios with one and two photodetectors. In addition, crystals with different levels of reflection and aspect ratios (AR) were analysed. Results showed that the impact of photodetector granularity is mainly shown near the edges and specially in the corners of the crystal. The resulting intrinsic spatial resolution near the centre with a 12 × 12 × 10 mm(3) LYSO crystal was 0.7-0.9 mm, while the average spatial resolution calculated on the entire crystal was 0.77 ± 0.18 mm for all the simulated geometries with one and two photodetectors. Having front and back photodetectors reduced the DoI bias (Euclidean distance between estimated DoI and real DoI) and improved the transversal resolution near the corners. In scenarios with one photodetector, small AR resulted in DoI inaccuracies for absorbed events at the entrance of the crystal. These inaccuracies were slightly reduced either by increasing the AR or reducing the amount of reflected light, and highly mitigated using two photodetectors. Using one photodetector, we obtained a piecewise DoI error model with a DoI resolution of 0.4-0.9 mm for a 1.2 AR crystal, and we observed that including a second photodetector or reducing the amount of reflections reduced the DoI bias but did not significantly improve the DoI resolution. Translating the piecewise DoI error model obtained in this study to image reconstruction we obtained a spatial resolution variability of 0.39 mm using 85% of the FoV, compared to 2.59 mm and 1.87 mm without DoI correction or with a dual layer system, respectively. PMID:25884464

  17. Studying Risk Factors Associated with Human Leptospirosis

    PubMed Central

    Kamath, Ramachandra; Swain, Subhashisa; Pattanshetty, Sanjay; Nair, N Sreekumaran

    2014-01-01

    Background: Leptospirosis is one of the most under diagnosed and underreported disease in both developed and developing countries including India. It is established that environmental conditions and occupational habit of the individuals put them at risk of acquiring disease, which varies from community to community. Various seroprevalence studies across the world have documented emerging situation of this neglected tropical disease, but limited have probed to identify the risk factors, especially in India. Objectives: The objective of this study was to identify the environmental and occupational risk factors associated with the disease in Udupi District. Materials and Methods: This population-based case-control study was carried out in Udupi, a District in Southern India from April 2012 until August 2012. Udupi is considered to be endemic for Leptospirosis and reported 116 confirmed cases in the year 2011. Seventy of 116 laboratory confirmed cases and 140 sex matched neighborhood healthy controls participated in the study. A predesigned, semi-structured and validated questionnaire was used for data collection through house to house visit and observations were noted about environmental conditions. Univariate analysis followed by multivariate analysis (back ward conditional logistic regression) was performed by using STATA version 9.2 (StataCorp, College Station, TX, USA) to identify potential risk factors. Results: Occupational factors such as outdoor activities (matched odds ratio [OR] of 3.95, 95% confidence interval [CI]: 1.19-13.0), presence of cut or wound at body parts during work (matched OR: 4.88, CI: 1.83-13.02) and environmental factors such as contact with rodents through using the food materials ate by rat (matched OR: 4.29, CI: 1.45-12.73) and contact with soil or water contaminated with urine of rat (matched OR: 4.58, CI: 1.43-14.67) were the risk factors identified to be associated with disease. Conclusion: Leptospirosis is still considered as neglected disease in the district. Early diagnosis and prompt treatment of cases can save many lives. However, there is a need of integrated rodent control measures with great effort to increase awareness and education among subjects in controlling the disease. PMID:24741223

  18. critcial human health issues in connection with future human missions to mMars: the HUMEX study of ESA

    NASA Astrophysics Data System (ADS)

    Horneck, G.; Humex Team

    ESA has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis was laid on human health and performance care as well as Advanced Life Support Developments including Bioregenerative Life Support Systems and environmental monitoring. The overall study goals were as follows: (i) to define reference scenarios for a European participation in human exploration and to estimate their influence on the Life Sciences and Life Support requirements; (ii) for selected mission scenarios, to critically assess the limiting factors for human health, wellbeing, and performance and to recommend relevant countermeasures; (iii) for selected mission scenarios, to critically assess the potential of Advanced Life Support Developments and to pro-pose a European strategy including terrestrial applications; (iv) to critically assess the feasibility of existing facilities and technologies on ground and in space as test-beds in preparation for human exploratory missions and to develop a test plan for ground and ISS campaigns; (v) to develop a roadmap for a future European strategy towards human exploratory missions, including preparatory activities and terrestrial applications and benefits. Two scenarios for a Mars mission were selected: (i) with a 30 days stay on Mars, and (ii) with about 500 days stay on Mars. The impact on human health, perform-ance and well being has been investigated from the view point of (i) the effects of microgravity (during space travel), reduced gravity (on Mars) and abrupt gravity changes (during launch and landing), (ii) the effects of cosmic radiation including solar particle events, (iii) psychological issues as well as general health care. Coun-termeasures as well as necessary research using ground-based testbeds and/or the ISS have been defined. The need for highly intelligent autonomous diagnostic and therapy systems was emphasized. Advanced life support systems with a high degree of autonomy and regenerative capacity and synergy effects were considered where bioregenerative life support systems and biodiagnostic systems become essential especially for the long-term Mars scenario. The considerations have been incorpo-rated into a roadmap for a future European strategy in human health issues for a potential European participation in a cooperative international exploration of our solar system by humans. Ref. Horneck et al, 2003, HUMEX, study on the Survivability and Adaptation of Humans to Long-Duration Exploratory Missions, ESA SP 1264

  19. Optical limiting and thermal lensing studies in C60 S. S. Harilal,a)

    E-print Network

    Harilal, S. S.

    Optical limiting and thermal lensing studies in C60 S. S. Harilal,a) C. V. Bindhu, V. P. N are discussed along with its thermo-optic properties. We used thermal lensing method to elucidate any nonlinear 1999 Optical limiting and thermo-optic properties of C60 in toluene are studied using 532 nm, 9 ns

  20. Intramolecular Isotope Effects for the Study of Reactions with MassTransfer Limitations 

    E-print Network

    Wagner, Joshua G.

    2010-01-16

    The research presented provides a method to use the comparison of intermolecular isotope effects vs. the intramolecular isotope effects for the study of reactions in which study of the rate limiting step is ambiguous due to interfering mass transfer...

  1. Risk assessment of diesel exhaust and lung cancer: combining human and animal studies after adjustment for biases in epidemiological studies

    PubMed Central

    2011-01-01

    Background Risk assessment requires dose-response data for the evaluation of the relationship between exposure to an environmental stressor and the probability of developing an adverse health effect. Information from human studies is usually limited and additional results from animal studies are often needed for the assessment of risks in humans. Combination of risk estimates requires an assessment and correction of the important biases in the two types of studies. In this paper we aim to illustrate a quantitative approach to combining data from human and animal studies after adjusting for bias in human studies. For our purpose we use the example of the association between exposure to diesel exhaust and occurrence of lung cancer. Methods Firstly, we identify and adjust for the main sources of systematic error in selected human studies of the association between occupational exposure to diesel exhaust and occurrence of lung cancer. Evidence from selected animal studies is also accounted for by extrapolating to average ambient, occupational exposure concentrations of diesel exhaust. In a second stage, the bias adjusted effect estimates are combined in a common effect measure through meta-analysis. Results The random-effects pooled estimate (RR) for exposure to diesel exhaust vs. non-exposure was found 1.37 (95% C.I.: 1.08-1.65) in animal studies and 1.59 (95% C.I.: 1.09-2.10) in human studies, whilst the overall was found equal to 1.49 (95% C.I.: 1.21-1.78) with a greater contribution from human studies. Without bias adjustment in human studies, the pooled effect estimate was 1.59 (95% C.I.: 1.28-1.89). Conclusions Adjustment for the main sources of uncertainty produced lower risk estimates showing that ignoring bias leads to risk estimates potentially biased upwards. PMID:21481231

  2. 76 FR 34703 - Human Studies Review Board Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ...SUMMARY: The U.S. Environmental Protection...appointment to its Human Studies Review Board (HSRB...new, independent human studies review board (i.e...Committee Act (FACA) 5 U.S.C. App. 2 Sec. 9...encourages nominations of women and men of all...

  3. 78 FR 35031 - Human Studies Review Board Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ...SUMMARY: The U.S. Environmental Protection...appointment to its Human Studies Review Board (HSRB...new, independent human studies review board (i.e...Committee Act (FACA) 5 U.S.C. App. 2 Sec. 9...encourages nominations of women and men of all...

  4. Basic study on avoidance motions for human behaviors

    Microsoft Academic Search

    M. Yoda; Y. Shiota

    1995-01-01

    The purpose of this study was propose the algorithm on the system including the mechanism to avoid a man. On basic study, this paper reports on the experiment of human avoidance motion, the experimental system for avoidance motions and experimental results. The human avoidance behavior occurs when passing each other. Many passings each of experimenter and subject have been recorded

  5. REPORTING NEEDS FOR STUDIES OF ENVIRONMENTAL CHEMICALS IN HUMAN MILK

    E-print Network

    California at Berkeley, University of

    REPORTING NEEDS FOR STUDIES OF ENVIRONMENTAL CHEMICALS IN HUMAN MILK Michael N. Bates School, USA Studies of environmental chemicals in human milk have been carried out in many coun- tries trends in exposure to chemicals, for research into the determinants of environmental chemicals in milk

  6. Roadmap: Physical Education Human Movement Studies Bachelor of Science

    E-print Network

    Sheridan, Scott

    Roadmap: Physical Education ­ Human Movement Studies ­ Bachelor of Science [EH-BS-PEP-HMS] College of Education, Health and Human Services School of Teaching, Learning and Curriculum Studies Catalog Year: 2013 Introduction to Physical Education, Fitness and Sport 3 US 10097 Destination Kent State: First Year Experience

  7. Roadmap: Physical Education Human Movement Studies Bachelor of Science

    E-print Network

    Sheridan, Scott

    Roadmap: Physical Education ­ Human Movement Studies ­ Bachelor of Science [EH-BS-PEP-HMS] College of Education, Health and Human Services School of Teaching, Learning and Curriculum Studies Catalog Year: 2012 Introduction to Physical Education, Fitness and Sport 3 US 10097 Destination Kent State: First Year Experience

  8. Outmigration, Human Development and Trade: A Central American Case Study

    Microsoft Academic Search

    Denise L. Stanley

    2010-01-01

    Controversy surrounds the large increase in international immigration, but little is known about the many drivers of this mobility. While most migration studies have focused on economic motivations, a small literature addresses the impact of human development and, indirectly, capability deprivation. This case study of southern Honduras examines migration patterns between 1988 and 1997 to assess the impacts of human

  9. Radium in humans: A review of U.S. studies

    SciTech Connect

    Rowland, R.E.

    1994-09-01

    This document was originally conceived as a compilation of activities at Argonne National Laboratory that were directed toward the study of radium in humans. However, it soon became obvious that this was a very limited approach, because such a compilation would include no background on the widespread uses of radium in industry and in the medical profession, nor would it address the early history of the discovery of the hazards of radium. Such an approach would also ignore contributions to the study of radium effects made at other laboratories. This document now addresses these topics, in order to give an overall picture of what might be called the radium era, that period from the early part of this century, when radium was rapidly exploited as a tool and a medication, to the present time, when radium is not generally used and the study of its effects has been terminated. The appendix to this review lists all of the measured radium cases, a total of 2,403 individuals whose records were in the files at the end of 1990. For each case the route of exposure, the dates of exposure, the years of birth and death, the measured body content, the calculated intake and dose, and the cause of death have been listed. 165 refs.

  10. Superior reproductive success on human blood without sugar is not limited to highly anthropophilic mosquito

    E-print Network

    Juliano, Steven A.

    conducted with Aedes albopictus Skuse and Ae. aegypti to compare the effects of sugar availabil- ity on age of the ability to thrive on human blood alone. Key words. Aedes albopictus, Aedes aegypti, blood.S.A. Abstract. Anthropophilic mosquitoes such as Aedes aegypti L. (Diptera: Culicidae) have been shown to have

  11. Variation in human brains may facilitate evolutionary change toward a limited range of phenotypes

    PubMed Central

    Charvet, Christine J.; Darlington, Richard B.; Finlay, Barbara L.

    2013-01-01

    Individual variation is the foundation for evolutionary change, but little is known about the nature of normal variation between brains. Phylogenetic variation across mammalian brains is characterized by high inter-correlations in brain region volumes, distinct allometric scaling for each brain region and the relative independence in olfactory and limbic structures volumes from the rest of the brain. Previous work examining brain variation in individuals of some domesticated species showed that these three features of phylogenetic variation were mirrored in individual variation. We extend this analysis to the human brain and 10 of its subdivisions (e.g., isocortex, hippocampus) by using magnetic resonance imaging scans of 90 human brains ranging between 16 to 25 years of age. Human brain variation resembles both the individual variation seen in other species, and variation observed across mammalian species. That is, the relative differences in the slopes of each brain region compared to medulla size within humans and between mammals are concordant, and limbic structures scale with relative independence from other brain regions. This non-random pattern of variation suggests that developmental programs channel the variation available for selection. PMID:23363667

  12. Repression of mammary adipogenesis by genistein limits mammosphere formation of human MCF-7 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mammary adipose tissue may contribute to breast cancer development and progression by altering neighboring epithelial cell behavior and phenotype through paracrine signaling. Dietary exposure to soy foods is associated with lower mammary tumor risk and reduced body weight and adiposity in humans and...

  13. Reasonable Limits and Exemptions: Victoria's Human Rights Charter and its Implications for Young People

    ERIC Educational Resources Information Center

    Bessant, Judith

    2009-01-01

    Many people had great expectations of the Victorian Charter of Human Rights and Responsibilities when it came into effect in January 2008. However, Judith Bessant asks whether the provision for seeking exemptions from the charter has undermined its capacity to effectively counter age-based discrimination and, paradoxically, permitted practices…

  14. A limited bibliography of the federal government-funded human radiation experiments

    Microsoft Academic Search

    E. Samei; K. J. Kearfott

    1995-01-01

    From the early 1940`s thousands of U.S. citizens have been the subjects of federally supported scientific experiments that involved the administration of ionizing radiation or radioactive substances. Recently, many questions have been raised regarding the nature, scientific value, and ethics of these experiments. Although the results of many of the early human experiments involving radiation have been crucial to the

  15. Understanding the limits of animal models as predictors of human biology: lessons learned from the sbv IMPROVER Species Translation Challenge

    PubMed Central

    Mathis, Carole; Dulize, Rémi H. J.; Ivanov, Nikolai V.; Alexopoulos, Leonidas; Jeremy Rice, J.; Peitsch, Manuel C.; Stolovitzky, Gustavo; Meyer, Pablo; Hoeng, Julia

    2015-01-01

    Motivation: Inferring how humans respond to external cues such as drugs, chemicals, viruses or hormones is an essential question in biomedicine. Very often, however, this question cannot be addressed because it is not possible to perform experiments in humans. A reasonable alternative consists of generating responses in animal models and ‘translating’ those results to humans. The limitations of such translation, however, are far from clear, and systematic assessments of its actual potential are urgently needed. sbv IMPROVER (systems biology verification for Industrial Methodology for PROcess VErification in Research) was designed as a series of challenges to address translatability between humans and rodents. This collaborative crowd-sourcing initiative invited scientists from around the world to apply their own computational methodologies on a multilayer systems biology dataset composed of phosphoproteomics, transcriptomics and cytokine data derived from normal human and rat bronchial epithelial cells exposed in parallel to 52 different stimuli under identical conditions. Our aim was to understand the limits of species-to-species translatability at different levels of biological organization: signaling, transcriptional and release of secreted factors (such as cytokines). Participating teams submitted 49 different solutions across the sub-challenges, two-thirds of which were statistically significantly better than random. Additionally, similar computational methods were found to range widely in their performance within the same challenge, and no single method emerged as a clear winner across all sub-challenges. Finally, computational methods were able to effectively translate some specific stimuli and biological processes in the lung epithelial system, such as DNA synthesis, cytoskeleton and extracellular matrix, translation, immune/inflammation and growth factor/proliferation pathways, better than the expected response similarity between species. Contact: pmeyerr@us.ibm.com or Julia.Hoeng@pmi.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25236459

  16. Sensitivity study of human crystalline lens accommodation

    Microsoft Academic Search

    A. Abolmaali; R. A. Schachar; T. Le

    2007-01-01

    A nonlinear axisymmetric finite element method (FEM) analysis was employed to determine the critical geometric and material properties that affect human accommodation. In this model, commencing at zero, zonular traction on all lens profiles resulted in central lentic- ular surface steepening and peripheral surface flattening, with a simultaneous increase in central lens thickness and central optical power. An age-related decline

  17. An epidemiologic study of the human bite.

    PubMed Central

    Marr, J S; Beck, A M; Lugo, J A

    1979-01-01

    The 892 human bites reported to the New York City Department of Health in 1977 were analyzed by time, place, and the victim's characteristics. The bites appeared to have a seasonality, increasing in March and exceeding the mean monthly average through August. The bite rate for the entire city, 10.7 per 100,000 population, was exceeded in 5 of the 10 Brooklyn health districts; one of these districts reported a rate of 60.9 human bites per 100,000 population. Most of the bites with identifiable locations occurred indoors (63.2 percent). In 72.8 percent of the bite episodes in which the activities surrounding them were known, these activities were aggressive in nature. Males exceeded females as bite victims in all age groups except those 10-20 and 55-60 years. Bites of the upper extremity accounted for 61.2 percent of the total bites. Left-sided bites exceeded right-sided, except for the hand. In frequency of reported occurrence, the human bite ranks third, after the dog bite and the cat bite. Human bites may be a useful indicator of antisocial behavior. PMID:515337

  18. Culture studies of human pluripotent hemopoietic progenitors

    Microsoft Academic Search

    H. A. Messner; A. A. Fauser

    1980-01-01

    Conclusions Culture conditions are described that promote the growth of human pluripotent hemopoietic progenitors and facilitate their quantitation. These primitive cells form mixed colonies that may contain all elements of myeloid differentiation, including granulocytes, erythroblasts, megakaryocytes, and macrophages. Some mixed colonies contain, in addition to mature progeny, early progenitors that can be identified by their ability to form secondary hemopoietic

  19. Electrophysiological Studies of Face Perception in Humans

    Microsoft Academic Search

    Shlomo Bentin; Truett Allison; Aina Puce; Erik Perez; Gregory McCarthy

    1996-01-01

    Event-related potentials (ERPs) associated with face perception were recorded with scalp electrodes from normal volunteers. Subjects performed a visual target detection task in which they mentally counted the number of occurrences of pictorial stimuli from a designated category such as butterflies. In separate experiments, target stimuli were embedded within a series of other stimuli including unfamiliar human faces and isolated

  20. Senescence occurs with hTERT repression and limited telomere shortening in human oral keratinocytes cultured with feeder cells.

    PubMed

    Kang, Mo K; Kameta, Ayako; Shin, Ki-Hyuk; Baluda, Marcel A; Park, No-Hee

    2004-06-01

    We investigated the phenotypic and molecular alterations in normal human oral keratinocytes (NHOK) during in vitro replication in two different culture conditions. The cells were cultured either in chemically defined Keratinocyte Growth Medium (KGM) without feeder layers or in serum-containing flavin-adenine dinucleotide (FAD) medium with feeder layers. Primary NHOK underwent 22 +/- 3 population doublings (PDs) in KGM and 42 +/- 4 PDs in FAD medium, reflecting 52% increase in replication capacity with feeder layers. In both culture conditions, exponentially replicating NHOK demonstrated telomerase activity and expression of human telomerase reverse transcriptase (hTERT) gene. Telomerase activity and hTERT expression were rapidly diminished in senescing NHOK, which exhibited small decrease of telomere length for the remaining limited cellular replications until the complete arrest of cell division. However, telomere length in senescent NHOK was 6.7 +/- 0.5 kilobase pairs (kbps), significantly longer than that (5.12 kbps) of senescent human fibroblasts. The onset of senescence was accompanied with marked induction of p16(INK4A), and this occurred in both culture systems using either KGM or FAD medium. These results indicate that replicative senescence of NHOK is associated with loss of telomerase activity followed by limited telomere shortening. PMID:15095283

  1. Generation of a suite of 3D computer-generated breast phantoms from a limited set of human subject data

    PubMed Central

    Hsu, Christina M. L.; Palmeri, Mark L.; Segars, W. Paul; Veress, Alexander I.; Dobbins, James T.

    2013-01-01

    Purpose: The authors previously reported on a three-dimensional computer-generated breast phantom, based on empirical human image data, including a realistic finite-element based compression model that was capable of simulating multimodality imaging data. The computerized breast phantoms are a hybrid of two phantom generation techniques, combining empirical breast CT (bCT) data with flexible computer graphics techniques. However, to date, these phantoms have been based on single human subjects. In this paper, the authors report on a new method to generate multiple phantoms, simulating additional subjects from the limited set of original dedicated breast CT data. The authors developed an image morphing technique to construct new phantoms by gradually transitioning between two human subject datasets, with the potential to generate hundreds of additional pseudoindependent phantoms from the limited bCT cases. The authors conducted a preliminary subjective assessment with a limited number of observers (n = 4) to illustrate how realistic the simulated images generated with the pseudoindependent phantoms appeared. Methods: Several mesh-based geometric transformations were developed to generate distorted breast datasets from the original human subject data. Segmented bCT data from two different human subjects were used as the “base” and “target” for morphing. Several combinations of transformations were applied to morph between the “base’ and “target” datasets such as changing the breast shape, rotating the glandular data, and changing the distribution of the glandular tissue. Following the morphing, regions of skin and fat were assigned to the morphed dataset in order to appropriately assign mechanical properties during the compression simulation. The resulting morphed breast was compressed using a finite element algorithm and simulated mammograms were generated using techniques described previously. Sixty-two simulated mammograms, generated from morphing three human subject datasets, were used in a preliminary observer evaluation where four board certified breast radiologists with varying amounts of experience ranked the level of realism (from 1 = “fake” to 10 = “real”) of the simulated images. Results: The morphing technique was able to successfully generate new and unique morphed datasets from the original human subject data. The radiologists evaluated the realism of simulated mammograms generated from the morphed and unmorphed human subject datasets and scored the realism with an average ranking of 5.87 ± 1.99, confirming that overall the phantom image datasets appeared more “real” than “fake.” Moreover, there was not a significant difference (p > 0.1) between the realism of the unmorphed datasets (6.0 ± 1.95) compared to the morphed datasets (5.86 ± 1.99). Three of the four observers had overall average rankings of 6.89 ± 0.89, 6.9 ± 1.24, 6.76 ± 1.22, whereas the fourth observer ranked them noticeably lower at 2.94 ± 0.7. Conclusions: This work presents a technique that can be used to generate a suite of realistic computerized breast phantoms from a limited number of human subjects. This suite of flexible breast phantoms can be used for multimodality imaging research to provide a known truth while concurrently producing realistic simulated imaging data. PMID:23556929

  2. Generation of a suite of 3D computer-generated breast phantoms from a limited set of human subject data

    SciTech Connect

    Hsu, Christina M. L. [Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Palmeri, Mark L. [Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Segars, W. Paul [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Veress, Alexander I. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Dobbins, James T. III [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2013-04-15

    Purpose: The authors previously reported on a three-dimensional computer-generated breast phantom, based on empirical human image data, including a realistic finite-element based compression model that was capable of simulating multimodality imaging data. The computerized breast phantoms are a hybrid of two phantom generation techniques, combining empirical breast CT (bCT) data with flexible computer graphics techniques. However, to date, these phantoms have been based on single human subjects. In this paper, the authors report on a new method to generate multiple phantoms, simulating additional subjects from the limited set of original dedicated breast CT data. The authors developed an image morphing technique to construct new phantoms by gradually transitioning between two human subject datasets, with the potential to generate hundreds of additional pseudoindependent phantoms from the limited bCT cases. The authors conducted a preliminary subjective assessment with a limited number of observers (n= 4) to illustrate how realistic the simulated images generated with the pseudoindependent phantoms appeared. Methods: Several mesh-based geometric transformations were developed to generate distorted breast datasets from the original human subject data. Segmented bCT data from two different human subjects were used as the 'base' and 'target' for morphing. Several combinations of transformations were applied to morph between the 'base' and 'target' datasets such as changing the breast shape, rotating the glandular data, and changing the distribution of the glandular tissue. Following the morphing, regions of skin and fat were assigned to the morphed dataset in order to appropriately assign mechanical properties during the compression simulation. The resulting morphed breast was compressed using a finite element algorithm and simulated mammograms were generated using techniques described previously. Sixty-two simulated mammograms, generated from morphing three human subject datasets, were used in a preliminary observer evaluation where four board certified breast radiologists with varying amounts of experience ranked the level of realism (from 1 ='fake' to 10 ='real') of the simulated images. Results: The morphing technique was able to successfully generate new and unique morphed datasets from the original human subject data. The radiologists evaluated the realism of simulated mammograms generated from the morphed and unmorphed human subject datasets and scored the realism with an average ranking of 5.87 {+-} 1.99, confirming that overall the phantom image datasets appeared more 'real' than 'fake.' Moreover, there was not a significant difference (p > 0.1) between the realism of the unmorphed datasets (6.0 {+-} 1.95) compared to the morphed datasets (5.86 {+-} 1.99). Three of the four observers had overall average rankings of 6.89 {+-} 0.89, 6.9 {+-} 1.24, 6.76 {+-} 1.22, whereas the fourth observer ranked them noticeably lower at 2.94 {+-} 0.7. Conclusions: This work presents a technique that can be used to generate a suite of realistic computerized breast phantoms from a limited number of human subjects. This suite of flexible breast phantoms can be used for multimodality imaging research to provide a known truth while concurrently producing realistic simulated imaging data.

  3. Limiting the impact of light pollution on human health, environment and stellar visibility

    Microsoft Academic Search

    Fabio Falchi; Pierantonio Cinzano; Christopher D. Elvidge; David M. Keith; Abraham Haim

    2011-01-01

    Light pollution is one of the most rapidly increasing types of environmental degradation. Its levels have been growing exponentially over the natural nocturnal lighting levels provided by starlight and moonlight. To limit this pollution several effective practices have been defined: the use of shielding on lighting fixture to prevent direct upward light, particularly at low angles above the horizon; no

  4. Estimating the number of rate limiting genomic changes for human breast cancer

    Microsoft Academic Search

    Xinan Zhang; Richard Simon

    2005-01-01

    We used multistage models that incorporate the age dependent dynamics of normal breast tissue, clonal expansion of intermediate cells and mutational events to fit data for the age-specific incidence of breast cancers in the surveillance, epidemiology, and end results (SEER) registry. Our results suggest that two or three rate limiting events occurring at rates characteristic of point mutation rates for

  5. An Asymptotic Study of Discretized Transport Equations in the Fokker-Planck Limit

    SciTech Connect

    Pautz, Shawn D. [Los Alamos National Laboratory (United States); Adams, Marvin L. [Texas A and M University (United States)

    2002-01-15

    Recent analyses have shown that the Fokker-Planck equation is an asymptotic limit of the transport equation given a forward-peaked scattering kernel satisfying certain constraints. Discretized transport equations in the same limit are studied, both by asymptotic analysis and by numerical testing. It is shown that spatially discretized discrete ordinates transport solutions can be accurate in this limit if and only if the scattering operator is handled in a certain nonstandard way.

  6. Katanin p80 regulates human cortical development by limiting centriole and cilia number.

    PubMed

    Hu, Wen F; Pomp, Oz; Ben-Omran, Tawfeg; Kodani, Andrew; Henke, Katrin; Mochida, Ganeshwaran H; Yu, Timothy W; Woodworth, Mollie B; Bonnard, Carine; Raj, Grace Selva; Tan, Thong Teck; Hamamy, Hanan; Masri, Amira; Shboul, Mohammad; Al Saffar, Muna; Partlow, Jennifer N; Al-Dosari, Mohammed; Alazami, Anas; Alowain, Mohammed; Alkuraya, Fowzan S; Reiter, Jeremy F; Harris, Matthew P; Reversade, Bruno; Walsh, Christopher A

    2014-12-17

    Katanin is a microtubule-severing complex whose catalytic activities are well characterized, but whose in vivo functions are incompletely understood. Human mutations in KATNB1, which encodes the noncatalytic regulatory p80 subunit of katanin, cause severe microlissencephaly. Loss of Katnb1 in mice confirms essential roles in neurogenesis and cell survival, while loss of zebrafish katnb1 reveals specific roles for katnin p80 in early and late developmental stages. Surprisingly, Katnb1 null mutant mouse embryos display hallmarks of aberrant Sonic hedgehog signaling, including holoprosencephaly. KATNB1-deficient human cells show defective proliferation and spindle structure, while Katnb1 null fibroblasts also demonstrate a remarkable excess of centrioles, with supernumerary cilia but deficient Hedgehog signaling. Our results reveal unexpected functions for KATNB1 in regulating overall centriole, mother centriole, and cilia number, and as an essential gene for normal Hedgehog signaling during neocortical development. PMID:25521379

  7. Epidemiological study of zoonoses derived from humans in captive chimpanzees.

    PubMed

    Kooriyama, Takanori; Okamoto, Michiko; Yoshida, Tomoyuki; Nishida, Toshisada; Tsubota, Toshio; Saito, Akatsuki; Tomonaga, Masaki; Matsuzawa, Tetsuro; Akari, Hirofumi; Nishimura, Hidekazu; Miyabe-Nishiwaki, Takako

    2013-01-01

    Emerging infectious diseases (EIDs) in wildlife are major threats both to human health and to biodiversity conservation. An estimated 71.8 % of zoonotic EID events are caused by pathogens in wildlife and the incidence of such diseases is increasing significantly in humans. In addition, human diseases are starting to infect wildlife, especially non-human primates. The chimpanzee is an endangered species that is threatened by human activity such as deforestation, poaching, and human disease transmission. Recently, several respiratory disease outbreaks that are suspected of having been transmitted by humans have been reported in wild chimpanzees. Therefore, we need to study zoonotic pathogens that can threaten captive chimpanzees in primate research institutes. Serological surveillance is one of several methods used to reveal infection history. We examined serum from 14 captive chimpanzees in Japanese primate research institutes for antibodies against 62 human pathogens and 1 chimpanzee-borne infectious disease. Antibodies tested positive against 29 pathogens at high or low prevalence in the chimpanzees. These results suggest that the proportions of human-borne infections may reflect the chimpanzee's history, management system in the institute, or regional epidemics. Furthermore, captive chimpanzees are highly susceptible to human pathogens, and their induced antibodies reveal not only their history of infection, but also the possibility of protection against human pathogens. PMID:22890486

  8. Sensitivity study of human crystalline lens accommodation.

    PubMed

    Abolmaali, A; Schachar, R A; Le, T

    2007-01-01

    A nonlinear axisymmetric finite element method (FEM) analysis was employed to determine the critical geometric and material properties that affect human accommodation. In this model, commencing at zero, zonular traction on all lens profiles resulted in central lenticular surface steepening and peripheral surface flattening, with a simultaneous increase in central lens thickness and central optical power. An age-related decline in maximum zonular tension appears to be the most likely etiology for the decrease in accommodative amplitude with age. PMID:17005291

  9. Epidemiologic studies of behavioral health following the Deepwater Horizon oil spill: limited impact or limited ability to measure?

    PubMed

    Teich, Judith L; Pemberton, Michael R

    2015-01-01

    Two large-scale epidemiologic federal surveys conducted in the Gulf Coast following the Deepwater Horizon oil spill and intended to measure its impact on mental disorders and substance use found less dramatic results than had been anticipated. However, several smaller-scale studies conducted shortly after the spill did find increases in the prevalence of certain psychological problems among individuals surveyed. Previous federal studies conducted following two disasters-the destruction of the World Trade Center (WTC) and Hurricanes Katrina and Rita-found few statistically significant changes in behavioral disorders in the wake of those events, except for individuals displaced from their homes by Katrina for 2 weeks or more. In this commentary, the authors discuss questions raised by these mixed results regarding the limitations of such studies, the behavioral health impact of the Deepwater Horizon spill compared to disasters causing more widespread loss of life and destruction of property, and the ways in which data collection following disasters might be improved to benefit public health planners. PMID:24557855

  10. Use of human pluripotent stem cells to study and treat retinopathies.

    PubMed

    Ben M'Barek, Karim; Regent, Florian; Monville, Christelle

    2015-04-26

    Human cell types affected by retinal diseases (such as age-related macular degeneration or retinitis pimentosa) are limited in cell number and of reduced accessibility. As a consequence, their isolation for in vitro studies of disease mechanisms or for drug screening efforts is fastidious. Human pluripotent stem cells (hPSCs), either of embryonic origin or through reprogramming of adult somatic cells, represent a new promising way to generate models of human retinopathies, explore the physiopathological mechanisms and develop novel therapeutic strategies. Disease-specific human embryonic stem cells were the first source of material to be used to study certain disease states. The recent demonstration that human somatic cells, such as fibroblasts or blood cells, can be genetically converted to induce pluripotent stem cells together with the continuous improvement of methods to differentiate these cells into disease-affected cellular subtypes opens new perspectives to model and understand a large number of human pathologies, including retinopathies. This review focuses on the added value of hPSCs for the disease modeling of human retinopathies and the study of their molecular pathological mechanisms. We also discuss the recent use of these cells for establishing the validation studies for therapeutic intervention and for the screening of large compound libraries to identify candidate drugs. PMID:25914766

  11. Egg Limitation in Parasitoids: A Review of the Evidence and a Case Study

    E-print Network

    Rosenheim, Jay A.

    Egg Limitation in Parasitoids: A Review of the Evidence and a Case Study George E. Heimpel* and Jay; accepted October 1, 1997 Life history theory predicts that a nontrivial propor- tion of parasitoids should in parasitoids and found partial support for this prediction. Most of the evidence in support of egg limitation

  12. Red, Yellow, Blue: A Primary Study of the Strengths, Limitations and Challenges of Arts Magnet Schools.

    ERIC Educational Resources Information Center

    Halquist, Don

    This primary, exploratory study combines the limited literature on arts magnet schools with the writings of arts activists and the narratives of several arts magnet school administrators in an attempt to understand arts magnet schools better. The paper illuminates some of the strengths of arts magnet schools as well as some of the limitations and…

  13. The Limits of Functional Analysis in the Study of Mass Communication.

    ERIC Educational Resources Information Center

    Anderson, James A.; Meyer, Timothy P.

    The fundamental limits of the functional approach to the study of mass communication are embodied in two of its criticisms. The first weakness is in its logical structure and the second involves the limits that are set by known methods. Functional analysis has difficulties as a meaningful research perspective because the process of mass…

  14. PLESA: Program for Persons of Limited English-Speaking Ability. Ten Case Studies.

    ERIC Educational Resources Information Center

    Reynolds, Jack; And Others

    These ten case studies of the Program for Persons of Limited English-Speaking Ability (PLESA) report different approaches to providing training and employment assistance to unemployed persons of limited English-speaking ability. (A summary report of forty-seven projects is available separately. See Note.) The first four describe projects conducted…

  15. The utilization of humanized mouse models for the study of human retroviral infections

    PubMed Central

    Van Duyne, Rachel; Pedati, Caitlin; Guendel, Irene; Carpio, Lawrence; Kehn-Hall, Kylene; Saifuddin, Mohammed; Kashanchi, Fatah

    2009-01-01

    The development of novel techniques and systems to study human infectious diseases in both an in vitro and in vivo settings is always in high demand. Ideally, small animal models are the most efficient method of studying human afflictions. This is especially evident in the study of the human retroviruses, HIV-1 and HTLV-1, in that current simian animal models, though robust, are often expensive and difficult to maintain. Over the past two decades, the construction of humanized animal models through the transplantation and engraftment of human tissues or progenitor cells into immunocompromised mouse strains has allowed for the development of a reconstituted human tissue scaffold in a small animal system. The utilization of small animal models for retroviral studies required expansion of the early CB-17 scid/scid mouse resulting in animals demonstrating improved engraftment efficiency and infectivity. The implantation of uneducated human immune cells and associated tissue provided the basis for the SCID-hu Thy/Liv and hu-PBL-SCID models. Engraftment efficiency of these tissues was further improved through the integration of the non-obese diabetic (NOD) mutation leading to the creation of NODSCID, NOD/Shi-scid IL2r?-/-, and NOD/SCID ?2-microglobulinnull animals. Further efforts at minimizing the response of the innate murine immune system produced the Rag2-/-?c-/- model which marked an important advancement in the use of human CD34+ hematopoietic stem cells. Together, these animal models have revolutionized the investigation of retroviral infections in vivo. PMID:19674458

  16. Study questions: Energy & Environment: Humans & Nature 18 May 2012 Two `Laws' of human nature

    E-print Network

    Study questions: Energy & Environment: Humans & Nature 18 May 2012 Two `Laws' of human nature 1. Jevons' Law, or the law of diminishing marginal utility One of the class (sorry, can't remember who) posted an interesting note on `Jevons' Law'. This would seem to be a danger signal for the hopeful

  17. Duckweed (Lemna minor) as a Model Plant System for the Study of Human Microbial Pathogenesis

    Microsoft Academic Search

    Yong Zhang; Yangbo Hu; Baoyu Yang; Fang Ma; Pei Lu; Lamei Li; Chengsong Wan; Simon Rayner; Shiyun Chen; Pere-Joan Cardona

    2010-01-01

    BackgroundPlant infection models provide certain advantages over animal models in the study of pathogenesis. However, current plant models face some limitations, e.g., plant and pathogen cannot co-culture in a contained environment. Development of such a plant model is needed to better illustrate host-pathogen interactions.Methodology\\/Principal FindingsWe describe a novel model plant system for the study of human pathogenic bacterial infection on

  18. A human laboratory pilot study with baclofen in alcoholic individuals

    PubMed Central

    Leggio, Lorenzo; Zywiak, William H.; McGeary, John E.; Edwards, Steven; Fricchione, Samuel R.; Shoaff, Jessica R.; Addolorato, Giovanni; Swift, Robert M.; Kenna, George A.

    2015-01-01

    Preclinical and clinical studies show that the GABAB receptor agonist baclofen may represent a pharmacotherapy for alcohol dependence (AD). However, the mechanisms by which baclofen affects drinking are not well characterized; thus this pilot study investigated possible baclofen’s biobehavioral mechanisms. The design was a double-blind controlled randomized human laboratory pilot study. Fourteen non-treatment seeking alcohol-dependent heavy drinking subjects received either baclofen 10 mg t.i.d. or an active placebo (cyproheptadine 2 mg t.i.d., to control for sedation) for a 7-day period. At day 8, participants performed an alcohol cue-reactivity (CR) followed by an alcohol self-administration (ASA). Additionally, we explored possible moderators that might guide future larger studies, i.e. anxiety, family history and onset of alcoholism, and D4 dopamine receptor (DRD4) and 5-HTTLPR polymorphisms. The main results were a significant effect of baclofen for increasing stimulation (p=.001) and sedation (p<.01). Furthermore, when drinking during the ASA and the 2 days before was analyzed as a composite variable, there was a significant effect of baclofen to reduce alcohol consumption (p<.01). As for the exploratory analyses, baclofen’s effects to increase alcohol sedation and to reduce alcohol consumption were limited to those individuals with DRD4 ?7 repeats (DRD4L). Yet, baclofen’s effects on alcohol consumption were also moderated by 5-HTTLPR LL genotype. In conclusion, baclofen’s ability to reduce alcohol drinking may be related to its effects on the biphasic effects of alcohol, but larger studies are needed to confirm these preliminary findings. PMID:23262301

  19. Study on Human-Computer Interaction platform for computer wargame

    Microsoft Academic Search

    Liu Jihong; Xu Xiaodong; Xu Xinhe

    2008-01-01

    Based on human-computer interaction (HCI) and visualization technologies, we focused on the research of the human-computer interaction platform of the wargame. Starting with analyzing the handcraft wargame, we studied the key technologies in the representation modules for battlefield environment and situation of battlefield, and finally set up a HCI platform model of the wargame. Testing experiment indicated that our work

  20. PRECLINICAL STUDY Adult human mesenchymal stem cells enhance breast

    E-print Network

    McLachlan, John

    . Keywords Mesenchymal stem cells Á Breast carcinoma Á Progesterone receptor Á Stromal-derived factor 1 ÁPRECLINICAL STUDY Adult human mesenchymal stem cells enhance breast tumorigenesis and promote Adult human mesenchymal stem cells (hMSCs) have been shown to home to sites of breast cancer

  1. Experimental and analytical tools for studying the human microbiome

    Microsoft Academic Search

    Justin Kuczynski; Christian L. Lauber; William A. Walters; Laura Wegener Parfrey; José C. Clemente; Dirk Gevers; Rob Knight

    2011-01-01

    The human microbiome substantially affects many aspects of human physiology, including metabolism, drug interactions and numerous diseases. This realization, coupled with ever-improving nucleotide sequencing technology, has precipitated the collection of diverse data sets that profile the microbiome. In the past 2 years, studies have begun to include sufficient numbers of subjects to provide the power to associate these microbiome features

  2. MAJOR: HUMAN DEVELOPMENT & FAMILY STUDIES (HDFS) EMPHASIS: EARLY CHILDHOOD EDCUATION

    E-print Network

    Tipple, Brett

    MAJOR: HUMAN DEVELOPMENT & FAMILY STUDIES (HDFS) EMPHASIS: EARLY CHILDHOOD EDCUATION Minimum HDFS Years 3 F, S, SU FCS 3215 Dev in Infancy and Childhood (BF) 3 F FCS 3216 Caring for Infants & Toddlers 3 2. HDFS CORE (6 Credit Hours) F, S, SU FCS 1500 Human Development Across the Lifespan (BF) 3 F, S

  3. Human Rights and History Education: An Australian Study

    ERIC Educational Resources Information Center

    Burridge Nina; Buchanan, John; Chodkiewicz, Andrew

    2014-01-01

    The place of education for and about human rights within the school curriculum remains contested and this paper reports on the first national cross-sectoral investigation of its place in Australian curricula and more specifically in national and state History curriculum documents. Opportunities for the inclusion of human rights based studies were…

  4. An Interdisciplinary Deer and Human Population Study

    NSDL National Science Digital Library

    2012-07-17

    This activity helps the learner answer the question: "What environmental problems arise due to animal and human overpopulation and what might need to be done to combat these problems?" Learners play a game that simulates population sampling in an imaginary state park. After the game is completed, each park must decide if they are at the carrying capacity for their park or out of equilibrium. Learners write a proposal detailing how they plan to correct their deer population problem and present it to the group (the Department of Natural Resources). This lesson is described as an interdisciplinary unit and includes literature and math curriculum connections.

  5. All humanity is my ingroup: a measure and studies of identification with all humanity.

    PubMed

    McFarland, Sam; Webb, Matthew; Brown, Derek

    2012-11-01

    To psychologists Adler (1927/1954) and Maslow (1954), fully mature individuals care deeply for all humanity, not just for their own ingroups. This paper reports a series of studies with a new measure of that caring, the Identification With All Humanity Scale (IWAH). These studies together show that identification with all humanity is more than an absence of ethnocentrism and its correlates and more than the presence of dispositional empathy, moral reasoning, moral identity, and the value of universalism. Across these studies, the IWAH predicted concern for global human rights and humanitarian needs (Studies 1 and 2), was temporally stable (Study 3), and correlated with how close others see one as being (Study 4). The IWAH strongly distinguished members of 2 known groups from a general adult sample (Study 5). It predicted valuing the lives of ingroup and outgroup members equally (Study 7), knowledge of global humanitarian concerns (Study 8) and choosing to learn about these concerns (Study 9), and a willingness to contribute to international humanitarian relief (Study 10). In regression analyses, it predicted these results beyond related constructs. Although psychologists have focused extensively upon negative qualities such as ethnocentrism and its roots, we suggest that the positive quality of identification with all humanity also merits extensive study. PMID:22708625

  6. Experimental studies of the charge limit phenomenon in GaAs photocathodes

    SciTech Connect

    Tang, H.; Alley, R.; Aoyagi, H.; Clendenin, J.; Saez, P.; Schultz, D.; Turner, J.

    1993-10-01

    GaAs photocathodes have been in use for generating high intensity polarized electron beams (up to a peak current of 6 A in 2 ns pulses) for the SLC high energy physics program. If the quantum efficiency (measured at low light intensities) of a GaAs photocathode is below a certain level, the maximum photoemitted charge is found to be limited by the intrinsic properties of the cathode instead of by the space charge limit. We have studied this charge limit phenomenon in a variety of GaAs photocathodes. The effects of the quantum efficiency, excitation laser wavelength, and extraction electric field on the charge limit have been examined. The temporal behavior of the charge limit as manifested in both intrapulse and interpulse effects has also been studied. These results will be discussed in light of possible mechanisms.

  7. Mine waste contamination limits soil respiration rates: a case study using quantile regression

    E-print Network

    Rilli, Matthias C.

    Mine waste contamination limits soil respiration rates: a case study using quantile regression metal) contamination using a statistical approach that facilitates separating trends in soil processes, bivariate scatter- grams of soil respiration values versus contaminant concen- trations often display

  8. Accident causation study on roadways with limited sight distance crest vertical curves 

    E-print Network

    Stoddard, Angela May

    1994-01-01

    reflect the driver and vehicle population currently on the transportation network. An accident causation study was conducted to determine if roadways with limited stopping sight distance present a safety hazard for the transportation network. Rural two...

  9. Accident causation study on roadways with limited sight distance crest vertical curves

    E-print Network

    Stoddard, Angela May

    1994-01-01

    reflect the driver and vehicle population currently on the transportation network. An accident causation study was conducted to determine if roadways with limited stopping sight distance present a safety hazard for the transportation network. Rural two...

  10. Development of humanized mouse models to study human malaria parasite infection

    PubMed Central

    Vaughan, Ashley M; Kappe, Stefan HI; Ploss, Alexander; Mikolajczak, Sebastian A

    2013-01-01

    Malaria is a disease caused by infection with Plasmodium parasites that are transmitted by mosquito bite. Five different species of Plasmodium infect humans with severe disease, but human malaria is primarily caused by Plasmodium falciparum. The burden of malaria on the developing world is enormous, and a fully protective vaccine is still elusive. One of the biggest challenges in the quest for the development of new antimalarial drugs and vaccines is the lack of accessible animal models to study P. falciparum infection because the parasite is restricted to the great apes and human hosts. Here, we review the current state of research in this field and provide an outlook of the development of humanized small animal models to study P. falciparum infection that will accelerate fundamental research into human parasite biology and could accelerate drug and vaccine design in the future. PMID:22568719

  11. A study of the effect of posted speed limits on traffic speeds

    E-print Network

    Rowan, Neilon Joyce

    1959-01-01

    A STUDY OF THE EPPECT OP POSTED SPEED LIMITS ON TRAFFIC SPEEDS A Thesis By Neilon Joyce Rowan Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment oi' the requirements for the degree... Distribution Curves for No Change in the Original 60-Nile-Par-Hour Speed Limit in District 12. Each Curve Represents Data Prom 7 Spot Speed Studies in 4 Locations. 37 12. 13. Cumulative Speed Distribution Curves for a Change in Speed Limit From 60 to 55...

  12. Safety, identity and consent: a limited defense of reproductive human cloning.

    PubMed

    Lane, Robert

    2006-06-01

    Some opponents of reproductive human cloning have argued that, because of its experimental nature, any attempt to create a child by way of cloning would risk serious birth defects or genetic abnormalities and would therefore be immoral. Some versions of this argument appeal to the consent of the person to be conceived in this way. In particular, they assume that if an experimental reproductive technology has not yet been shown to be safe, then, before we use it, we are morally obligated to get either the actual consent or the presumed consent of the person to be conceived. In this article, I attempt to explain the appeal of such consent-based arguments as deriving from a mistaken view of personal identity. I then argue that since this view is false, such arguments are unsound. Finally, I argue that even if reproductive cloning is unsafe, it may still be morally permissible in some circumstances. PMID:17039631

  13. USE OF EXHALED BREATH CONDENSATE IN A HUMAN EXPOSURE STUDY

    EPA Science Inventory

    Exhaled breath condensate (EBC) is a noninvasive, repeatable collection technique to sample biomarkers of lung inflammation, oxidative stress, and environmental exposure. It is unclear whether EBC is an effective tool in human environmental exposure studies with multi-day samplin...

  14. Human tracking studies involving an actively powered, augmented exoskeleton

    Microsoft Academic Search

    D. W. Repperger; B. O. Hill; C. Hasser; M. Roark; C. A. Phillips

    1996-01-01

    An actively powered, augmented, exoskeleton system is studied within a speed-accuracy performance task framework with human subjects. This system has a dual use in military applications as well as for the rehabilitation of patients with neuromotor disorders

  15. Quantifying planetary limits of Earth system processes relevant to human activity using a thermodynamic view of the whole Earth system

    NASA Astrophysics Data System (ADS)

    Kleidon, Axel

    2014-05-01

    Food, water, and energy play, obviously, a central role in maintaining human activity. In this contribution, I derive estimates for the fundamental limits on the rates by which these resources are provided by Earth system processes and the levels at which these can be used sustainably. The key idea here is that these resources are, directly or indirectly, generated out of the energy associated with the absorption of sunlight, and that the energy conversions from sunlight to other forms ultimately limit the generation of these resources. In order to derive these conversion limits, we need to trace the links between the processes that generate food, water and energy to the absorption of sunlight. The resource "food" results from biomass production by photosynthesis, which requires light and a sufficient magnitude of gas exchange of carbon dioxide at the surface, which is maintained by atmospheric motion which in turn is generated out of differential radiative heating and cooling. The resource "water" is linked to hydrologic cycling, with its magnitude being linked to the latent heat flux of the surface energy balance and water vapor transport in the atmosphere which is also driven by differential radiative heating and cooling. The availability of (renewable) energy is directly related to the generation of different forms of energy of climate system processes, such as the kinetic energy of atmospheric motion, which, again, relates to radiative heating differences. I use thermodynamics and its limits as a basis to establish the planetary limits of these processes and use a simple model to derive first-order estimates. These estimates compare quite well with observations, suggesting that this thermodynamic view of the whole Earth system provides an objective, physical basis to define and quantify planetary boundaries as well as the factors that shape these boundaries.

  16. Motion sensitivity of human V6: A magnetoencephalography study

    Microsoft Academic Search

    Veronika von Pföstl; Linda Stenbacka; Simo Vanni; Lauri Parkkonen; Claudio Galletti; Patrizia Fattori

    2009-01-01

    Recent studies suggest the presence of a human homologue of monkey V6 in the dorsal posterior bank of the parieto-occipital sulcus. Monkey V6 comprises a retinotopic representation with relative peripheral visual field emphasis and is sensitive to visual motion. We studied sensitivity to visual motion in human parieto-occipital sulcus. Our upper peripheral visual field stimulus enabled us to distinguish V6

  17. Functional Analysis of the Human Genome:. Study of Genetic Disease

    NASA Astrophysics Data System (ADS)

    Tsui, Lap-Chee

    2003-04-01

    I will divide my remarks into 3 parts. First, I will give a brief summary of the Human Genome Project. Second, I will describe our work on human chromosome 7 to illustrate how we could contribute to the Project and disease research. Third, I would like to bring across the argument that study of genetic disease is an integral component of the Human Genome Project. In particular, I will use cystic fibrosis as an example to elaborate why I consider disease study is a part of functional genomics.

  18. Use of human epidermal cells in the study of carcinogenesis

    SciTech Connect

    Kuroki, T.; Chida, K.; Hosomi, J.; Kondo, S. (Institute of Medical Science, Tokyo (Japan))

    1989-05-01

    Because of the importance of human cells, particularly human epithelial cells, in cancer research, we have studied certain phases or events of carcinogenesis using human epidermal cells in primary culture. (1) We found that human epidermal cells are capable of metabolizing benzo(a)pyrene. Large inter-individual variations are found in the basal and induced arylhydrocarbon-hydroxylase activities. (2) UV-induced unscheduled DNA synthesis was demonstrated in human epidermal cells on autoradiographs. We also found that DNA repair is defective in epidermal cells isolated from xeroderma pigmentosum by a new explant-outgrowth culture. (3) Human epidermal cells are unique in that there is a large number of binding sites to phorbol esters compared with mouse epidermal cells, but there is no down-regulation. Further, human epidermal cells show essentially negative responses to tumor promoters, i.e., no stimulation of DNA synthesis, sugar uptake, and no induction of ornithine decarboxylase activity. (4) Human epidermal cells contain 1.5 x 10(5) binding sites per cell for epidermal growth factor (EGF), whereas squamous cell carcinomas of skin and oral cavity have larger amounts of EGF receptors in the order of 10(6) per cell. (5) Based on the above results, we attempted to transform human epidermal cells by the treatment with chemical carcinogens, but until now no transformation was obtained. 16 references.

  19. Experimental studies of the charge limit phenomenon in NEA GaAs photocathodes

    SciTech Connect

    Tang, H.; Alley, R.K.; Aoyagi, H.; Clendenin, J.E.; Frisch, J.C.; Mulhollan, G.A.; Saez, P.J.; Schultz, D.C.; Turner, J.L.

    1994-06-01

    Negative electron affinity GaAs photocathodes have been in continuous use at SLAC for generating polarized electron beams since early 1992. If the quantum efficiency of a GaAs cathode is below a critical value, the maximum photoemitted charge with photons of energies close to the band gap in a 2-ns pulse is found to be limited by the intrinsic properties of the cathode instead of by the space charge limit. We have studied this novel charge limit phenomenon in a variety of GaAs photocathodes of different structures and doping densities. We find that the charge limit is strongly dependent on the cathode`s quantum efficiency and the extraction electric field, and to a lesser degree on the excitation laser wavelength. In addition, we show that the temporal behavior of the charge limit depends critically on the doping density.

  20. Today's ``safe" radiofrequency (RF) exposure limits DON'T protect human health near transmitters!

    NASA Astrophysics Data System (ADS)

    Lundquist, Marjorie

    2005-03-01

    Maxwell's theory implies that electromagnetic (EM) radiation carries both energy and momentum. ``The momentum may have both linear and angular contributions; angular momentum [AM] has a spin part associated with polarization and an orbital part associated with spatial distribution. Any interaction between radiation and matter is inevitably accompanied by an exchange of momentum. This often has mechanical consequences ..."^2 Voluntary consensus standards [ANSI C95; NCRP; INCIRP] protect human health from most thermal [energy transfer] effects, but no standards yet exist to protect health against athermal [momentum transfer] effects, though laboratory transfer of spin AM was reported by 1935^3 and of orbital AM by 1992^2 for an optical vortex [tip of Poynting vector (PV) traces a helix about the beam axis]. In the far field of a dipole RF transmitter, radiation is linearly polarized (minimal spin AM) and locally approximated by a plane wave (zero orbital AM), but in the near field the orbital AM is non-zero [tip of PV traces an ellipse^4 in air] implying an athermal hazard [e.g., brain tumors in cellular phone users] against which no standard now in use anywhere in the world protects! ^2 L. Allen et al. Phys. Rev. A 45:8185-9(1992). ^3 R.A. Beth, Phys. Rev. 48:471(1935); 50:115-25 (1936). ^4 F. Landstorfer, Archiv für Elektronik und übertragungstechnik 26:189-96(1972) [in German].

  1. ON THE LIMITS OF CULTURE: WHY BIOLOGY IS IMPORTANT IN THE STUDY OF VICTORIAN SEXUALITY

    Microsoft Academic Search

    ROBERT BURNS

    Much recent scholarship in Victorian studies has viewed sexuality as historically contingent and constructed primarily within the realm of discourse or social organization. In contrast, the following study details species-typical and universal aspects of human sexuality that must be adequately theorized if an accurate model of the ideological forces impacting Victorian sexuality is to be fashioned. After a short survey

  2. Risk management study: Importance of human element

    SciTech Connect

    Knief, R.A.; Briant, V.S.; Lee, R.B.; Mahn, J.A.; Shaw, R.A.

    1989-01-01

    The March 1979 accident at Three Mile Island unit 2 (TMI-2) caused neither deaths nor injuries to plant workers or the general public, nor did it release a significant quantity of radioisotopes to the environment. GPU Nuclear Corporation (GPUN), the subsidiary responsible for the cleanup of TMI-2 and the operation of TMI-1 and Oyster Creek units, has recognized important accident lessons and seeks to assure that nothing of similar consequence happens again. To this end, a risk management group (RMG) was formed in early 1988 to develop a framework for proactive identification, evaluation, and cost-effective reduction and management of risks of all types. The RMG set out to learn as much as possible about risks and their management in nuclear and other high-technology industries. The RMG has been developing a basic model that identifies and describes attributes of safety and risk-management programs. These are divided among four categories, management, people, activities, and equipment. The integration of these elements into a basic decision-making process for management is the essential challenge. Position papers are in preparation or under consideration on specific key issues, including professionalism; critique feedback and followup; PRA uses (including desktop-computer applications); simulation interactions with training, operating and emergency procedure development, job design, and human factors; and safety ethos.

  3. BLT Humanized Mice as Model to Study HIV Vaginal Transmission

    PubMed Central

    Deruaz, Maud; Luster, Andrew D.

    2013-01-01

    The majority of human immunodeficiency virus type 1 (HIV-1) infections occur by sexual exposure, and vaginal transmission accounts for more than half of all newly acquired infections. Studies of vaginal transmission of simian immunodeficiency virus to nonhuman primates (NHPs) have suggested an important role for immune cell trafficking in the establishment of infection as well is in the process of viral dissemination. However, NHP models do not permit the study of HIV transmission and dissemination. The improvement of humanized mouse models with robust human immune cell reconstitution of the female genital tract renders these mice susceptible to intravaginal HIV infection. Thus humanized mouse models of HIV vaginal infection will allow the study of the mechanisms involved in HIV transmission and dissemination in vivo. PMID:24151319

  4. An intermittent control model of flexible human gait using a stable manifold of saddle-type unstable limit cycle dynamics.

    PubMed

    Fu, Chunjiang; Suzuki, Yasuyuki; Kiyono, Ken; Morasso, Pietro; Nomura, Taishin

    2014-12-01

    Stability of human gait is the ability to maintain upright posture during walking against external perturbations. It is a complex process determined by a number of cross-related factors, including gait trajectory, joint impedance and neural control strategies. Here, we consider a control strategy that can achieve stable steady-state periodic gait while maintaining joint flexibility with the lowest possible joint impedance. To this end, we carried out a simulation study of a heel-toe footed biped model with hip, knee and ankle joints and a heavy head-arms-trunk element, working in the sagittal plane. For simplicity, the model assumes a periodic desired joint angle trajectory and joint torques generated by a set of feed-forward and proportional-derivative feedback controllers, whereby the joint impedance is parametrized by the feedback gains. We could show that a desired steady-state gait accompanied by the desired joint angle trajectory can be established as a stable limit cycle (LC) for the feedback controller with an appropriate set of large feedback gains. Moreover, as the feedback gains are decreased for lowering the joint stiffness, stability of the LC is lost only in a few dimensions, while leaving the remaining large number of dimensions quite stable: this means that the LC becomes saddle-type, with a low-dimensional unstable manifold and a high-dimensional stable manifold. Remarkably, the unstable manifold remains of low dimensionality even when the feedback gains are decreased far below the instability point. We then developed an intermittent neural feedback controller that is activated only for short periods of time at an optimal phase of each gait stride. We characterized the robustness of this design by showing that it can better stabilize the unstable LC with small feedback gains, leading to a flexible gait, and in particular we demonstrated that such an intermittent controller performs better if it drives the state point to the stable manifold, rather than directly to the LC. The proposed intermittent control strategy might have a high affinity for the inverted pendulum analogy of biped gait, providing a dynamic view of how the step-to-step transition from one pendular stance to the next can be achieved stably in a robust manner by a well-timed neural intervention that exploits the stable modes embedded in the unstable dynamics. PMID:25339687

  5. An intermittent control model of flexible human gait using a stable manifold of saddle-type unstable limit cycle dynamics

    PubMed Central

    Fu, Chunjiang; Suzuki, Yasuyuki; Kiyono, Ken; Morasso, Pietro; Nomura, Taishin

    2014-01-01

    Stability of human gait is the ability to maintain upright posture during walking against external perturbations. It is a complex process determined by a number of cross-related factors, including gait trajectory, joint impedance and neural control strategies. Here, we consider a control strategy that can achieve stable steady-state periodic gait while maintaining joint flexibility with the lowest possible joint impedance. To this end, we carried out a simulation study of a heel-toe footed biped model with hip, knee and ankle joints and a heavy head-arms-trunk element, working in the sagittal plane. For simplicity, the model assumes a periodic desired joint angle trajectory and joint torques generated by a set of feed-forward and proportional-derivative feedback controllers, whereby the joint impedance is parametrized by the feedback gains. We could show that a desired steady-state gait accompanied by the desired joint angle trajectory can be established as a stable limit cycle (LC) for the feedback controller with an appropriate set of large feedback gains. Moreover, as the feedback gains are decreased for lowering the joint stiffness, stability of the LC is lost only in a few dimensions, while leaving the remaining large number of dimensions quite stable: this means that the LC becomes saddle-type, with a low-dimensional unstable manifold and a high-dimensional stable manifold. Remarkably, the unstable manifold remains of low dimensionality even when the feedback gains are decreased far below the instability point. We then developed an intermittent neural feedback controller that is activated only for short periods of time at an optimal phase of each gait stride. We characterized the robustness of this design by showing that it can better stabilize the unstable LC with small feedback gains, leading to a flexible gait, and in particular we demonstrated that such an intermittent controller performs better if it drives the state point to the stable manifold, rather than directly to the LC. The proposed intermittent control strategy might have a high affinity for the inverted pendulum analogy of biped gait, providing a dynamic view of how the step-to-step transition from one pendular stance to the next can be achieved stably in a robust manner by a well-timed neural intervention that exploits the stable modes embedded in the unstable dynamics. PMID:25339687

  6. Activated endothelial cells limit inflammatory response, but increase chemoattractant potential and bacterial clearance by human monocytes.

    PubMed

    Mancilla-Herrera, Ismael; Alvarado-Moreno, José Antonio; Cérbulo-Vázquez, Arturo; Prieto-Chávez, Jessica L; Ferat-Osorio, Eduardo; López-Macías, Constantino; Estrada-Parra, Sergio; Isibasi, Armando; Arriaga-Pizano, Lourdes

    2015-06-01

    Inflammation is the normal immune response of vascularized tissues to damage and bacterial products, for which leukocyte transendothelial migration (TEM) is critical. The effects of cell-to-cell contact seen in both leukocyte and endothelial cells include cytoskeleton rearrangement, and dynamic expression of adhesion molecules and metalloproteinases. TEM induces expression of anti-apoptotic molecules, costimulatory molecules associated with antigen presentation, and pattern recognition receptors (PRR), such as TLR-4, in monocytes. However, little is known about how TLR-4 increment operates in monocytes during an inflammatory response. To understand it better, we used an in vitro model in which monocytes crossed a layer of IL-1? stimulated Human Umbilical Vein Endothelial Cells (HUVEC). After TEM, monocytes were tested for the secretion of inflammatory cytokines and chemokines, their phenotype (CD14, CD16, TLR-4 expression), and TLR-4 canonical [Nuclear Factor kappa B, (NF-?B) pathway] and non-canonical [p38, extracellular signal-regulated kinases (ERK) 1/2 pathway] signal transduction induced by lipopolysaccharide (LPS). Phagocytosis and bacterial clearance were also measured. There was diminished secretion of LPS-induced inflammatory cytokines (IL-1?, IL-6, and TNF-?) and higher secretion of chemokines (CXCL8/IL-8 and CCL2/MCP-1) in supernatant of TEM monocytes. These changes were accompanied by increases in TLR-4, CD14 (surfaces expression), p38, and ERK1/2 phosphorylated cytoplasmic forms, without affecting NF-?B activation. It also increased bacterial clearance after TEM by an O2 -independent mechanism. The data suggest that interaction between endothelial cells and monocytes fine-tunes the inflammatory response and promotes bacterial elimination. PMID:25598193

  7. Autophagy limits the cytotoxic effects of the AKT inhibitor AZ7328 in human bladder cancer cells

    PubMed Central

    Dickstein, Rian J.; Nitti, Giovanni; Dinney, Colin P.; Davies, Barry R.; Kamat, Ashish M.; McConkey, David J.

    2012-01-01

    Background: Mutations that activate the PI3K/AKT/mTOR pathway are relatively common in urothelial (bladder) cancers, but how these pathway mutations affect AKT dependency is not known. We characterized the relationship between AKT pathway mutational status and sensitivity to the effects of the selective AKT kinase inhibitor AZ7328 using a panel of 12 well-characterized human bladder cancer cell lines. Methods: Sequenome DNA sequencing was performed to identify mutations in a panel of 12 urothelial cancer cell lines. Drug-induced proliferative inhibition and apoptosis were quantified using MTT assays and propidium iodide staining with FACS analyses. Protein activation via phosphorylation was measured by immunoblotting. Autophagy was measured by LC3 immunofluorescence and immunoblotting. Results: AZ7328 inhibited proliferation and AKT substrate phosphorylation in a concentration-dependent manner but had minimal effects on apoptosis. Proliferative inhibition correlated loosely with the presence of activating PIK3CA mutations and was strengthened in combination with the mTOR inhibitor rapamycin. AZ7328 induced autophagy in some of the lines, and in the cells exposed to a combination of AZ7328 and chemical autophagy inhibitors apoptosis was induced. Conclusions: The cytostatic effects of AZ7328 correlate with PIK3CA mutations and are greatly enhanced by dual pathway inhibition using an mTOR inhibitor. Furthermore, AZ7328 can interact with autophagy inhibitors to induce apoptosis in some cell lines. Overall, our results support the further evaluation of combinations of PI3K/AKT/mTOR pathway and autophagy inhibitors in pre-clinical in vivo models and ultimately in patients with PIK3CA mutant bladder cancers. PMID:22895070

  8. Molecular genetic study of human arginase deficiency

    PubMed Central

    Grody, Wayne W.; Klein, Deborah; Dodson, Amy E.; Kern, Rita M.; Wissmann, Paul B.; Goodman, Barbara K.; Bassand, Patrick; Marescau, Bert; Kang, Soo-Sang; Leonard, James V.; Cederbaum, Stephen D.

    1992-01-01

    We have explored the molecular pathology in 28 individuals homozygous or heterozygous for liver arginase deficiency (hyperargininemia) by a combination of Southern analysis, western blotting, DNA sequencing, and PCR. This cohort represents the majority of arginase-deficient individuals worldwide. Only 2 of 15 homozygous patients on whom red blood cells were available had antigenically cross-reacting material as ascertained by western blot analysis using anti–liver arginase antibody. Southern blots of patient genomic DNAs, cut with a variety of restriction enzymes and probed with a near-full-length (1,450-bp) human liver arginase cDNA clone, detected no gross gene deletions. Loss of a TaqI cleavage site was identified in three individuals: in a homozygous state in a Saudi Arabian patient at one site, at a different site in homozygosity in a German patient, and in heterozygosity in a patient from Australia. The changes in the latter two were localized to exon 8, through amplification of this region by PCR and electrophoretic analysis of the amplified fragment after treatment with TaqI; the precise base changes (Arg291X and Thr290Ser) were confirmed by sequencing. It it interesting that the latter nucleotide variant (Thr290Ser) was found to lie adjacent to the TaqI site rather than within it, though whether such a conservative amino acid substitution represents a true pathologic mutation remains to be determined. We conclude that arginase deficiency, though rare, is a heterogeneous disorder at the genotypic level, generally encompassing a variety of point mutations rather than substantial structural gene deletions. ImagesFigure 1Figure 3Figure 4Figure 5 PMID:1598908

  9. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans

    NASA Technical Reports Server (NTRS)

    Wright, K. P. Jr; Hughes, R. J.; Kronauer, R. E.; Dijk, D. J.; Czeisler, C. A.

    2001-01-01

    Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis and for the proper timing of species-specific behaviors. We studied subjects in the laboratory for up to 55 days each to determine the ability to entrain the human clock to a weak circadian synchronizing stimulus [scheduled activity-rest cycle in very dim (approximately 1.5 lux in the angle of gaze) light-dark cycle] at three approximately 24-h periods: 23.5, 24.0, and 24.6 h. These studies allowed us to test two competing hypotheses as to whether the period of the human circadian pacemaker is near to or much longer than 24 h. We report here that imposition of a sleep-wake schedule with exposure to the equivalent of candle light during wakefulness and darkness during sleep is usually sufficient to maintain circadian entrainment to the 24-h day but not to a 23.5- or 24.6-h day. Our results demonstrate functionally that, in normally entrained sighted adults, the average intrinsic circadian period of the human biological clock is very close to 24 h. Either exposure to very dim light and/or the scheduled sleep-wake cycle itself can entrain this near-24-h intrinsic period of the human circadian pacemaker to the 24-h day.

  10. Role of the Medial Structures in the intact and Anterior Cruciate Ligament-Deficient KneeLimits of Motion in the Human Knee

    Microsoft Academic Search

    Jonathan L. Haimes; Randall R. Wroble; Edward S. Grood; Frank R. Noyes

    1994-01-01

    We measured motion limits in human cadaveric knees before and after sectioning the anterior cruciate liga ment and the medial structures. Sectioning the medial collateral ligament in an anterior cruciate ligament- deficient knee increased the anterior translation limit at 90° of flexion but not at 30° of flexion. The tibia displaced straight anteriorly without exhibiting the coupled internal rotation that

  11. Experimental and Numerical Study on Temperature Evolution for Rapid Evaluation of Fatigue Limit

    NASA Astrophysics Data System (ADS)

    Ly, H. A.; Inoue, H.; Irie, Y.

    2010-06-01

    This study is intended to verify the technique of rapid evaluation of fatigue limit through numerical simulation. Temperature evolution of a notched stainless steel specimen subjected to cyclic loading is simulated by elasto-plastic finite element analysis. Amplitude of second harmonic is obtained from the temperature evolution. It has been shown that the fatigue limit evaluated from the second harmonic amplitude agree fairly well with those obtained by thermography experiment and Wöhler method.

  12. A study of the factors limiting the life of copper bromide lasers

    NASA Astrophysics Data System (ADS)

    Astadzhov, D. N.; Vuchkov, N. K.; Petrash, G. G.; Sabotinov, N. V.

    Results of an experimental study of the factors limiting the life of copper bromide lasers are reported. It is shown that, although there are many factors that can limit the laser life, no fundamental obstacles exist that can prevent the development of discharge tubes with a life of 500 hr or more through proper design. It is also noted that, with proper design, the lasing characteristics of copper bromide lasers can be comparable with those of copper vapor lasers.

  13. Space station human productivity study, volume 1

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The primary goal was to develop design and operations requirements for direct support of intra-vehicular activity (IVA) crew performance and productivity. It was recognized that much work had already been accomplished which provided sufficient data for the definition of the desired requirements. It was necessary, therefore, to assess the status of such data to extract definable requirements, and then to define the remaining study needs. The explicit objectives of the study were to: review existing data to identify potential problems of space station crew productivity and to define requirements for support of productivity insofar as they could be justified by current information; identify those areas that lack adequate data; and prepare plans for managing studies to develop the lacking data, so that results can be input to the space station program in a timely manner.

  14. POTENTIAL AND LIMITATIONS OF EXISTING TECHNICAL ALTERNATIVES ON HUMAN EXCRETA AND DOMESTIC

    E-print Network

    Richner, Heinz

    , deepest gratitude and sincere thanks to my supervisor, Dr. Thammarat Koottatep, for his excellent my sincere gratitude and thanks to Dr. Toshiya Aramaki and Dr. Nguyen Thi Kim Oanh for their valuable), for granting the scholarship, which makes my dream of studying at AIT come true. My sincere gratitude also

  15. How Many Penguins Does it Take? Studying Carrying Capacity and Limiting Factors

    NSDL National Science Digital Library

    Elissa Elliott

    This hands-on activity simulates the process of population fluctuation. Students will learn the terms limiting factors and carrying capacity. Rather than memorize these terms, the students can see the terms come to life in this animated penguin activity. The results clearly show how populations are affected by many things -- one of them being food availability. This particular activity focuses on a penguin population; however, serious debates regarding the human population and the carrying capacity of the earth have been going on for some time. Students will: predict what the carrying capacity of a penguin population of a certain area will be; engage in a hands-on activity, simulating the way carrying capacity works; and explain what the terms carrying capacity and limiting factors mean for a population. Students can do further research on penguins and how they survive the Antarctic cold.

  16. Medieval Studies The School of Humanities

    E-print Network

    Richards-Kortum, Rebecca

    Medieval Art · MDST 331 Gothic Art and Architecture in Northern Europe, 1140­1300 · MDST 332 Late Gothic Art and Architecture in Northern Europe, 1300­1500 #12;222 departments / Medieval Studies Classical Intermediate Latin II English MDST 300 Medieval Women Writers MDST 310 Dante in Translation MDST 311 Old

  17. Anthropometric growth study of normal human auricle

    Microsoft Academic Search

    M. Tayyar Kalcioglu; M. Cem Miman; Yuksel Toplu; Cengiz Yakinci; Orhan Ozturan

    2003-01-01

    Objective: The aim of this study was to reveal the anthropometric growth of auricula from birth to the age of 18 years and to bring out the dynamics of ear growth. Material and methods: A total of 1552 children in 50 groups were evaluated. Six surface measurements were performed directly on the right auricle of the subjects: the length from

  18. On memetic Differential Evolution frameworks: A study of advantages and limitations in hybridization

    Microsoft Academic Search

    Ferrante Neri; Ville Tirronen

    2008-01-01

    This paper aims to study the benefits and limitations in the hybridization of the differential evolution with local search algorithms. In order to perform this study, the performance of three memetic algorithms employing a differential evolution as an evolutionary framework and several local search algorithms adaptively coordinated by means of a fitness diversity logic have been analyzed. The performance of

  19. Detecting directional coupling in the human epileptic brain: Limitations and potential pitfalls

    NASA Astrophysics Data System (ADS)

    Osterhage, Hannes; Mormann, Florian; Wagner, Tobias; Lehnertz, Klaus

    2008-01-01

    We study directional relationships—in the driver-responder sense—in networks of coupled nonlinear oscillators using a phase modeling approach. Specifically, we focus on the identification of drivers in clusters with varying levels of synchrony, mimicking dynamical interactions between the seizure generating region (epileptic focus) and other brain structures. We demonstrate numerically that such an identification is not always possible in a reliable manner. Using the same analysis techniques as in model systems, we study multichannel electroencephalographic recordings from two patients suffering from focal epilepsy. Our findings demonstrate that—depending on the degree of intracluster synchrony—certain subsystems can spuriously appear to be driving others, which should be taken into account when analyzing field data with unknown underlying dynamics.

  20. Human cardiac physiology in the phase plane: the ejection fraction to limit cycle area relation

    Microsoft Academic Search

    S. Eucker; J. B. Lisauskas; J. Singh; S. J. Kovacs

    1999-01-01

    Current physiologic parameters acquired during cardiac catheterization include the systolic, minimum, and end-diastolic left ventricular pressures, the ejection fraction, and the maximum and minimum rates of pressure rise and fall. To extract additional physiologic information from the left ventricular pressure (LVP) contour, we utilized phase plane analysis (dP\\/dt vs P) to study LVP. One cardiac cycle generates a closed loop,

  1. Does the respiratory system limit the aerobic working capacity of humans?

    Microsoft Academic Search

    I. S. Breslav; M. O. Segizbaeva; G. G. Isaev

    2000-01-01

    The question concerning respiratory function reserves among the factors determining the maximal power of muscular work is\\u000a considered. Even in strenuous physical exercise, pulmonary ventilation does not exceed a rather constant level for every individual.\\u000a Studies conducted using the programmed isocapnic hyperpnea method developed by the authors demonstrated that this level precisely\\u000a reflects the functional respiratory reserve that is one

  2. Studying the Human– Computer–Terminology Interface

    Microsoft Academic Search

    James J Cimino; Vimla L Patel; Andre W Kushniruk

    2001-01-01

    ObjectiveTo explore the use of an observational, cognitive-based approach for differentiating between successful, suboptimal, and failed entry of coded data by clinicians in actual practice, and to detect whether causes for unsuccessful attempts to capture true intended meaning were due to terminology content, terminology representation, or user interface problems.DesignObservational study with videotaping and subsequent coding of data entry events in

  3. Using Humanoid Robots to Study Human Behavior

    Microsoft Academic Search

    Christopher G. Atkeson; Joshua G. Hale; Frank E. Pollick; Marcia Riley; Shinya Kotosaka; Stefan Schaal; Tomohiro Shibata; Gaurav Tevatia; Ales Ude; Sethu Vijayakumar; Mitsuo Kawato

    2000-01-01

    cept the eye DOFs, which have noload sensing. The robot is currently mountedat the pelvis, so that we do not have to worryabout balance and can focus our studies onupper-body movement. We plan to explorefull-body motion in the future, probably witha new robot design.Inverse kinematics andtrajectory formationOne problem that robots with eyes face isvisually guided manipulation---for example,choosing appropriate joint angles

  4. Human factors and cardiac surgery: A multicenter study

    Microsoft Academic Search

    Marc R. de Leval; Jane Carthey; David J. Wright; Vernon T. Farewell; James T. Reason

    2000-01-01

    Objective: To study the role of human factors on surgical outcomes, with a series of 243 arterial switch operations performed by 21 surgeons taken as a model. Methods: The following data were collected: patient-specific and procedural variables, self-assessment questionnaires, and a written report from a human factors researcher who observed the operation. The relationship of patient-specific variables to outcomes (death

  5. Characterizing interspecies uncertainty using data from studies of anti-neoplastic agents in animals and humans

    SciTech Connect

    Price, Paul S. [Dow Chemical Company, Toxicology and Environmental Research and Consulting, 1803 Building, Midland MI 48674 (United States)], E-mail: pprice@dow.com; Keenan, Russell E. [AMEC Earth and Environmental, 15 Franklin Street, Portland, ME 04101 (United States); Swartout, Jeffrey C. [National Center for Environmental Assessment U.S. Environmental Protection Agency, 26 W. M. L. King Drive, Cincinnati, OH 45268 (United States)

    2008-11-15

    For most chemicals, the Reference Dose (RfD) is based on data from animal testing. The uncertainty introduced by the use of animal models has been termed interspecies uncertainty. The magnitude of the differences between the toxicity of a chemical in humans and test animals and its uncertainty can be investigated by evaluating the inter-chemical variation in the ratios of the doses associated with similar toxicological endpoints in test animals and humans. This study performs such an evaluation on a data set of 64 anti-neoplastic drugs. The data set provides matched responses in humans and four species of test animals: mice, rats, monkeys, and dogs. While the data have a number of limitations, the data show that when the drugs are evaluated on a body weight basis: 1) toxicity generally increases with a species' body weight; however, humans are not always more sensitive than test animals; 2) the animal to human dose ratios were less than 10 for most, but not all, drugs; 3) the current practice of using data from multiple species when setting RfDs lowers the probability of having a large value for the ratio. These findings provide insight into inter-chemical variation in animal to human extrapolations and suggest the need for additional collection and analysis of matched toxicity data in humans and test animals.

  6. Numerical Study on Stress Concentration Effect in Rapid Evaluation of Fatigue Limit through Temperature Evolution

    NASA Astrophysics Data System (ADS)

    Ly, Hung Anh; Inoue, Hirotsugu; Irie, Yousuke

    The technique for rapid evaluation of fatigue limit using infrared thermography has been developed and paid much attention recently. However, the enhancement of reliability of this technique is demanded for practical application in industries. This study is conducted to verify the effect of stress concentration on fatigue limit evaluation through numerical simulation. Temperature evolutions of stainless steel specimens with different notches are simulated by 3D elasto-plastic finite element analysis. It has been shown that the fatigue limit evaluation based on the temperature evolution is essentially explained by plastic energy dissipation, and that the temperature evolution should be measured after a sufficiently large number of cycles so that plastic shakedown is achieved. It has been remarked that the fatigue limit is overestimated if the spatial resolution of infrared thermography is not fine enough to measure the temperature evolution at the stress concentration site.

  7. Timing of Limitations in Life Support in Acute Lung Injury Patients: A Multi-Site Study

    PubMed Central

    Turnbull, Alison E.; Ruhl, A. Parker; Lau, Bryan M.; Mendez-Tellez, Pedro A.; Shanholtz, Carl B.; Needham, Dale M.

    2013-01-01

    Objective Substantial variability exists in the timing of limitations in life support for critically ill patients. Our objective was to investigate how the timing of limitations in life support varies with changes in organ failure status and time since acute lung injury (ALI) onset. Design, Setting, and Patients This evaluation was performed as part of a prospective cohort study evaluating 490 consecutive ALI patients recruited from 11 intensive care units (ICUs) at three teaching hospitals in Baltimore, MD. Interventions None. Measurements The primary exposure was proportion of days without improvement in Sequential Organ Failure Assessment (SOFA) score, evaluated as a daily time-varying exposure. The outcome of interest was a documented limitation in life support defined as any of the following: (1) No CPR, (2) Do not re-intubate, (3) No vasopressors, (4) No hemodialysis, (5) Do not escalate care or (6) Other limitation (e.g., “comfort care only”). Main Results For medical ICU (MICU) patients without improvement in daily SOFA score, the rate of limitation in life support tripled in the first three days after ALI onset, increased again after Day 5, and peaked at Day 19. Compared to MICU patients, surgical ICU (SICU) patients had a rate of limitations that was significantly lower during the first five days after ALI onset. In all patients, more days without improvement in SOFA scores was associated with limitations in life support, independent of the absolute magnitude of the SOFA score. Conclusions Persistent organ failure is associated with an increase in the rate of limitations in life support independent of the absolute magnitude of SOFA score, and this association strengthens during the first weeks of treatment. During the first five days after ALI onset limitations were significantly more common in MICUs than SICUs. PMID:23989178

  8. Human biomonitoring studies in North Rhine-Westphalia, Germany

    Microsoft Academic Search

    Michael Wilhelm; Ulrich Ewers; Jürgen Wittsiepe; Peter Fürst; Jürgen Hölzer; Georg Eberwein; Jürgen Angerer; Boleslaw Marczynski; Ulrich Ranft

    2007-01-01

    The areas along the rivers Rhine, Ruhr and Wupper in North Rhine-Westphalia (NRW), Germany, represent the largest urban and industrial agglomeration in Europe with about 10 million inhabitants. Human biomonitoring (HBM) studies have been conducted in these areas since more than 30 years, mainly designed to evaluate internal exposure to air pollutants. Recent studies were focussed on residents living near

  9. Asian Studies The School of Humanities and the School of

    E-print Network

    Richards-Kortum, Rebecca

    97 Asian Studies The School of Humanities and the School of Social Sciences DIRECTOR Steven Lewis: BA Asian Studies is an interdisciplinary major that explores the complex interaction between on the diversity and achievements of Asian civilizations but also on the ways an understanding of Asia may shed new

  10. REPORTING NEEDS FOR STUDIES OF ENVIRONMENTAL CHEMICALS IN HUMAN MILK

    Microsoft Academic Search

    Michael N. Bates; Sherry G. Selevan; Susan M. Ellerbee; Lawrence M. Gartner

    2002-01-01

    Studies of environmental chemicals in human milk have been carried out in many countries, but few have been conducted in the United States. These studies are useful for monitoring population trends in exposure to chemicals, for research into the determinants of environmental chemicals in milk and relationships between the levels found and the health status of the women and their

  11. REPORTING NEEDS FOR STUDIES OF ENVIRONMENTAL CHEMICALS IN HUMAN MILK

    EPA Science Inventory

    Studies of environmental chemicals in human milk have been carried out in many countries, but few have been conducted in the U.S. These studies are useful for monitoring populations trends in exposure to chemiclas, for research in the determinants of environmental chemicals in m...

  12. Manifold Learning for Human Population Structure Studies

    PubMed Central

    Siu, Hoicheong; Jin, Li; Xiong, Momiao

    2012-01-01

    The dimension of the population genetics data produced by next-generation sequencing platforms is extremely high. However, the “intrinsic dimensionality” of sequence data, which determines the structure of populations, is much lower. This motivates us to use locally linear embedding (LLE) which projects high dimensional genomic data into low dimensional, neighborhood preserving embedding, as a general framework for population structure and historical inference. To facilitate application of the LLE to population genetic analysis, we systematically investigate several important properties of the LLE and reveal the connection between the LLE and principal component analysis (PCA). Identifying a set of markers and genomic regions which could be used for population structure analysis will provide invaluable information for population genetics and association studies. In addition to identifying the LLE-correlated or PCA-correlated structure informative marker, we have developed a new statistic that integrates genomic information content in a genomic region for collectively studying its association with the population structure and LASSO algorithm to search such regions across the genomes. We applied the developed methodologies to a low coverage pilot dataset in the 1000 Genomes Project and a PHASE III Mexico dataset of the HapMap. We observed that 25.1%, 44.9% and 21.4% of the common variants and 89.2%, 92.4% and 75.1% of the rare variants were the LLE-correlated markers in CEU, YRI and ASI, respectively. This showed that rare variants, which are often private to specific populations, have much higher power to identify population substructure than common variants. The preliminary results demonstrated that next generation sequencing offers a rich resources and LLE provide a powerful tool for population structure analysis. PMID:22272259

  13. Comparison of Storage Conditions for Human Vaginal Microbiome Studies

    PubMed Central

    Bai, Guoyun; Gajer, Pawel; Nandy, Melissa; Ma, Bing; Yang, Hongqiu; Sakamoto, Joyce; Blanchard, May H.; Ravel, Jacques; Brotman, Rebecca M.

    2012-01-01

    Background The effect of storage conditions on the microbiome and metabolite composition of human biological samples has not been thoroughly investigated as a potential source of bias. We evaluated the effect of two common storage conditions used in clinical trials on the bacterial and metabolite composition of the vaginal microbiota using pyrosequencing of barcoded 16S rRNA gene sequencing and 1H-NMR analyses. Methodology/Principal Findings Eight women were enrolled and four mid-vaginal swabs were collected by a physician from each woman. The samples were either processed immediately, stored at ?80°C for 4 weeks or at ?20°C for 1 week followed by transfer to ?80°C for another 4 weeks prior to analysis. Statistical methods, including Kolmogorovo-Smirnov and Wilcoxon tests, were performed to evaluate the differences in vaginal bacterial community composition and metabolites between samples stored under different conditions. The results showed that there were no significant differences between samples processed immediately after collection or stored for varying durations. 1H-NMR analysis of the small molecule metabolites in vaginal secretions indicated that high levels of lactic acid were associated with Lactobacillus-dominated communities. Relative abundance of lactic acid did not appear to correlate with relative abundance of individual Lactobacillus sp. in this limited sample, although lower levels of lactic acid were observed when L. gasseri was dominant, indicating differences in metabolic output of seemingly similar communities. Conclusions/Significance These findings benefit large-scale, field-based microbiome and metabolomic studies of the vaginal microbiota. PMID:22655031

  14. Overview of the Final MEIC Results: II. The In Vitro In Vivo Evaluation, Including the Selection of a Practical Battery of Cell Tests for Prediction of Acute Lethal Blood Concentrations in Humans 1 1 Lists of reference chemicals and in vitro assays used in the MEIC study are found in the preceding paper of this series (Tables 1 and 2, in Clemedson and Ekwall, 1999) and have not been reiterated in the present paper because of space limitation

    Microsoft Academic Search

    B Ekwall

    1999-01-01

    In MEIC, all 50 reference chemicals were tested in 61 in vitro assays. To provide a background to the in vitro\\/in vivo evaluation, mouse LD50 values were compared with human lethal doses, resulting in a good correlation (R2 0.65). To study the relevance of in vitro results, IC50 values were compared with human lethal blood concentrations (LCs) by linear regression.

  15. Improving the translation of animal ischemic stroke studies to humans.

    PubMed

    Jickling, Glen C; Sharp, Frank R

    2015-04-01

    Despite testing more than 1,026 therapeutic strategies in models of ischemic stroke and 114 therapies in human ischemic stroke, only one agent tissue plasminogen activator has successfully been translated to clinical practice as a treatment for acute stroke. Though disappointing, this immense body of work has led to a rethinking of animal stroke models and how to better translate therapies to patients with ischemic stroke. Several recommendations have been made, including the STAIR recommendations and statements of RIGOR from the NIH/NINDS. In this commentary we discuss additional aspects that may be important to improve the translational success of ischemic stroke therapies. These include use of tissue plasminogen activator in animal studies; modeling ischemic stroke heterogeneity in terms of infarct size and cause of human stroke; addressing the confounding effect of anesthesia; use of comparable therapeutic dosage between humans and animals based on biological effect; modeling the human immune system; and developing outcome measures in animals comparable to those used in human stroke trials. With additional study and improved animal modeling of factors involved in human ischemic stroke, we are optimistic that new stroke therapies will be developed. PMID:24526567

  16. Studying the Human– Computer–Terminology Interface

    PubMed Central

    Cimino, James J.; Patel, Vimla L.; Kushniruk, Andre W.

    2001-01-01

    Objective: To explore the use of an observational, cognitive-based approach for differentiating between successful, suboptimal, and failed entry of coded data by clinicians in actual practice, and to detect whether causes for unsuccessful attempts to capture true intended meaning were due to terminology content, terminology representation, or user interface problems. Design: Observational study with videotaping and subsequent coding of data entry events in an outpatient clinic at New York Presbyterian Hospital. Participants: Eight attending physicians, 18 resident physicians, and 1 nurse practitioner, using the Medical Entities Dictionary (MED) to record patient problems, medications, and adverse reactions in an outpatient medical record system. Measurements: Classification of data entry events as successful, suboptimal, or failed, and estimation of cause; recording of system response time and total event time. Results: Two hundred thirty-eight data entry events were analyzed; 71.0 percent were successful, 6.3 percent suboptimal, and 22.7 percent failed; unsuccessful entries were due to problems with content in 13.0 percent of events, representation problems in 10.1 percent of events, and usability problems in 5.9 percent of events. Response time averaged 0.74 sec, and total event time averaged 40.4 sec. Of an additional 209 tasks related to drug dose and frequency terms, 94 percent were successful, 0.5 percent were suboptimal, and 6 percent failed, for an overall success rate of 82 percent. Conclusions: Data entry by clinicians using the outpatient system and the MED was generally successful and efficient. The cognitive-based observational approach permitted detection of false-positive (suboptimal) and false-negative (failed due to user interface) data entry. PMID:11230384

  17. Ontology-based federated data access to human studies information.

    PubMed

    Sim, Ida; Carini, Simona; Tu, Samson W; Detwiler, Landon T; Brinkley, James; Mollah, Shamim A; Burke, Karl; Lehmann, Harold P; Chakraborty, Swati; Wittkowski, Knut M; Pollock, Brad H; Johnson, Thomas M; Huser, Vojtech

    2012-01-01

    Human studies are one of the most valuable sources of knowledge in biomedical research, but data about their design and results are currently widely dispersed in siloed systems. Federation of these data is needed to facilitate large-scale data analysis to realize the goals of evidence-based medicine. The Human Studies Database project has developed an informatics infrastructure for federated query of human studies databases, using a generalizable approach to ontology-based data access. Our approach has three main components. First, the Ontology of Clinical Research (OCRe) provides the reference semantics. Second, a data model, automatically derived from OCRe into XSD, maintains semantic synchrony of the underlying representations while facilitating data acquisition using common XML technologies. Finally, the Query Integrator issues queries distributed over the data, OCRe, and other ontologies such as SNOMED in BioPortal. We report on a demonstration of this infrastructure on data acquired from institutional systems and from ClinicalTrials.gov. PMID:23304360

  18. Ontology-Based Federated Data Access to Human Studies Information

    PubMed Central

    Sim, Ida; Carini, Simona; Tu, Samson W.; Detwiler, Landon T.; Brinkley, James; Mollah, Shamim A.; Burke, Karl; Lehmann, Harold P.; Chakraborty, Swati; Wittkowski, Knut M.; Pollock, Brad H.; Johnson, Thomas M.; Huser, Vojtech

    2012-01-01

    Human studies are one of the most valuable sources of knowledge in biomedical research, but data about their design and results are currently widely dispersed in siloed systems. Federation of these data is needed to facilitate large-scale data analysis to realize the goals of evidence-based medicine. The Human Studies Database project has developed an informatics infrastructure for federated query of human studies databases, using a generalizable approach to ontology-based data access. Our approach has three main components. First, the Ontology of Clinical Research (OCRe) provides the reference semantics. Second, a data model, automatically derived from OCRe into XSD, maintains semantic synchrony of the underlying representations while facilitating data acquisition using common XML technologies. Finally, the Query Integrator issues queries distributed over the data, OCRe, and other ontologies such as SNOMED in BioPortal. We report on a demonstration of this infrastructure on data acquired from institutional systems and from ClinicalTrials.gov. PMID:23304360

  19. The association between exposure determined by radiofrequency personal exposimeters and human exposure: a simulation study.

    PubMed

    Neubauer, Georg; Cecil, Stefan; Giczi, Wolfram; Petric, Benjamin; Preiner, Patrick; Fröhlich, Jürg; Röösli, Martin

    2010-10-01

    The selection of an adequate exposure assessment approach is imperative for the quality of epidemiological studies. The use of personal exposimeters turned out to be a reasonable approach to determine exposure profiles, however, certain limitations regarding the absolute values delivered by the devices have to be considered. Apart from the limited dynamic range, it has to be taken into account that these devices give only an approximation of the exposure due to the influence of the body of the person carrying the exposimeter, the receiver characteristics of the exposimeter, as well as the dependence of the measured value on frequency band, channel, slot configuration, and communication traffic. In this study, the relationship between the field strength measured close to the human body at the location of the exposimeter and the exposure, that is, the field strength at the location of the human body without the human body present, is investigated by numerical means using the Visible Human model as an anatomical phantom. Two different scenarios were chosen: (1) For FM, GSM, and UMTS an urban outdoor scenario was examined that included a transmitting antenna mounted on the roof of one of four buildings at a street crossing, (2) For WLAN an indoor scenario was investigated. For GSM the average degree of underestimation by the exposimeter (relation of the average field levels at the location of the exposimeter to the field level averaged over the volume of the human body without the body present) was 0.76, and for UMTS 0.87; for FM no underestimation was found, the ratio was 1. In the case of WLAN the degree of underestimation was more pronounced, the ratio was 0.64. This study clearly suggests that a careful evaluation of correction factors for different scenarios is needed prior to the definition of the study protocol. It has to be noted that the reference scenario used in this study does not allow for final conclusions on general correction factors. PMID:20564178

  20. An applied study of human detection in single images

    NASA Astrophysics Data System (ADS)

    Liu, Ren; Xie, Xianghua

    2012-01-01

    In this paper we perform an applied comparative study of popular HOG based human detection and a state-of-the-art pose adaptive method that uses shape-based model construction. Both methods are implemented with kernel SVM, instead of linear SVM. Detailed performance evaluation is carried out on MIT pedestrian dataset and INRIA person dataset. This study shows that, although pose adaptive method has no significant advantage compared to the HOG based approach on those datasets, the pose adaptive approach is more efficient in detection and it has the capability to segment the human shape from images while carrying out detection which can be advantageous in many applications.

  1. A qualitative case study to identify possible barriers that limit effective elementary science education

    Microsoft Academic Search

    Donald Carey Foster

    2006-01-01

    The purpose of this case study was to identify barriers that limit the effectiveness of elementary teachers in the teaching of science. It is of the utmost urgency that barriers be first identified, so that possible solutions can be explored to bring about the improvement of elementary science education. This urgency has been imposed by the scheduled national testing of

  2. Permissible Limits of Arm Dimensions for Master-Slave System -Study on Telexistence (LVI)-

    E-print Network

    Tachi, Susumu

    56 Permissible Limits of Arm Dimensions for Master-Slave System -Study on Telexistence (LVI of slave robots in master-slave system, the fact that the dimensions of user does not match the dimensions of slave robot influence on the task performance. In particular, it is important to define analytically

  3. A Limit Study of JavaScript Parallelism Emily Fortuna Owen Anderson Luis Ceze Susan Eggers

    E-print Network

    Anderson, Richard

    A Limit Study of JavaScript Parallelism Emily Fortuna Owen Anderson Luis Ceze Susan Eggers Computer://sampa.cs.washington.edu Abstract--JavaScript is ubiquitous on the web. At the same time, the language's dynamic behavior makes on the potential parallelism of JavaScript appli- cations, including popular web pages and standard Java

  4. Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain

    E-print Network

    Duan, Benchun

    , a potential high- level radioactive waste storage site, is reported in Stepp et al. (2001) as mostly of critical facilities at the Yucca Mountain site. To address these extreme ground motions, Hanks et al. (2006Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain by Benchun Duan and Steven

  5. Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain

    E-print Network

    Duan, Benchun

    -level radioactive waste storage site,30 mostly in the context of a probability of exceedance of 10-4 /yr facilities at the Yucca Mountain site. To address these extreme ground motions, Hanks et37 al. (20061 Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain Benchun Duan1 and Steven

  6. COMPARATIVE KINETIC STUDIES OF PHOSPHATE-LIMITED GROWTH AND PHOSPHATE UPTAKE IN PHYTOPLANKTON IN CONTINUOUS CULTURE

    EPA Science Inventory

    A comparative kinetic study of phosphate-limited growth and phosphate uptake was carried out in chemostat cultures of Anabaena flos-aquae Lyng. Breb., Ankistrodesmus falcatus (Corda) Ralfs, Asterionella formosa Hass., Fragilaria crotonensis Kitt., and Microcystis sp. Lemm. For ea...

  7. Reconceptualizing Treatment Goals from Language Impairment to Functional Limitations: A Case Study

    ERIC Educational Resources Information Center

    Skarakis-Doyle, Elizabeth

    2005-01-01

    This case study of a preadolescent boy with severe expressive and receptive language impairments illustrates treatment focused on the functional limitations on the child's daily academic activities and social participation. Treatment goals incorporated language comprehension objectives into the student's reading program and language use objectives…

  8. Succession of Ephemeral Secondary Forests and Their Limited Role for the Conservation of Floristic Diversity in a Human-Modified Tropical Landscape

    PubMed Central

    van Breugel, Michiel; Hall, Jefferson S.; Craven, Dylan; Bailon, Mario; Hernandez, Andres; Abbene, Michele; van Breugel, Paulo

    2013-01-01

    Both local- and landscape-scale processes drive succession of secondary forests in human-modified tropical landscapes. Nonetheless, until recently successional changes in composition and diversity have been predominantly studied at the patch level. Here, we used a unique dataset with 45 randomly selected sites across a mixed-use tropical landscape in central Panama to study forest succession simultaneously on local and landscape scales and across both life stages (seedling, sapling, juvenile and adult trees) and life forms (shrubs, trees, lianas, and palms). To understand the potential of these secondary forests to conserve tree species diversity, we also evaluated the diversity of species that can persist as viable metapopulations in a dynamic patchwork of short-lived successional forests, using different assumptions about the average relative size at reproductive maturity. We found a deterministic shift in the diversity and composition of the local plant communities as well as the metacommunity, driven by variation in the rate at which species recruited into and disappeared from the secondary forests across the landscape. Our results indicate that dispersal limitation and the successional niche operate simultaneously and shape successional dynamics of the metacommunity of these early secondary forests. A high diversity of plant species across the metacommunity of early secondary forests shows a potential for restoration of diverse forests through natural succession, when trees and fragments of older forests are maintained in the agricultural matrix and land is abandoned or set aside for a long period of time. On the other hand, during the first 32 years the number of species with mature-sized individuals was a relatively small and strongly biased sub-sample of the total species pool. This implies that ephemeral secondary forests have a limited role in the long-term conservation of tree species diversity in human-modified tropical landscapes. PMID:24349283

  9. Succession of ephemeral secondary forests and their limited role for the conservation of floristic diversity in a human-modified tropical landscape.

    PubMed

    van Breugel, Michiel; Hall, Jefferson S; Craven, Dylan; Bailon, Mario; Hernandez, Andres; Abbene, Michele; van Breugel, Paulo

    2013-01-01

    Both local- and landscape-scale processes drive succession of secondary forests in human-modified tropical landscapes. Nonetheless, until recently successional changes in composition and diversity have been predominantly studied at the patch level. Here, we used a unique dataset with 45 randomly selected sites across a mixed-use tropical landscape in central Panama to study forest succession simultaneously on local and landscape scales and across both life stages (seedling, sapling, juvenile and adult trees) and life forms (shrubs, trees, lianas, and palms). To understand the potential of these secondary forests to conserve tree species diversity, we also evaluated the diversity of species that can persist as viable metapopulations in a dynamic patchwork of short-lived successional forests, using different assumptions about the average relative size at reproductive maturity. We found a deterministic shift in the diversity and composition of the local plant communities as well as the metacommunity, driven by variation in the rate at which species recruited into and disappeared from the secondary forests across the landscape. Our results indicate that dispersal limitation and the successional niche operate simultaneously and shape successional dynamics of the metacommunity of these early secondary forests. A high diversity of plant species across the metacommunity of early secondary forests shows a potential for restoration of diverse forests through natural succession, when trees and fragments of older forests are maintained in the agricultural matrix and land is abandoned or set aside for a long period of time. On the other hand, during the first 32 years the number of species with mature-sized individuals was a relatively small and strongly biased sub-sample of the total species pool. This implies that ephemeral secondary forests have a limited role in the long-term conservation of tree species diversity in human-modified tropical landscapes. PMID:24349283

  10. Human Robotic Study at Houghton Crater - virtual reality study from NASA Ames (FFC) Future Fight

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Human Robotic Study at Houghton Crater - virtual reality study from NASA Ames (FFC) Future Fight Central simulator tower L-R: Dr Geoffrey Briggs; Jen Jasper (seated); Dr Jan Akins and Mr. Tony Gross, Ames

  11. HUMEX, a study on the survivability and adaptation of humans to long- duration exploratory missions

    NASA Astrophysics Data System (ADS)

    Horneck, G.

    ESA has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis was laid on human health and performance care as well as Advanced Life Support Developments including Bioregenerative Life Support Systems and environmental monitoring. The overall study goals were as follows: (i) to define reference scenarios for a European participation in human exploration and to estimate their influence on the Life Sciences and Life Support requirements; (ii) for selected mission scenarios, to critically assess the limiting factors for human health, wellbeing, and performance and to recommend relevant countermeasures; (iii) for selected mission scenarios, to critically assess the potential of Advanced Life Support Developments and to propose a European strategy including terrestrial applications; (iv) to critically assess the feasibility of existing facilities and technologies on ground and in space as testbeds in preparation for human exploratory missions and to develop a test plan for ground and ISS campaigns; (v) to develop a roadmap for a future European strategy towards human exploratory missions, including preparatory activities and terrestrial applications and benefits. A lunar base at the south pole where constant sunlight and potential water ice deposits could be assumed was selected as the moon scenario. the impact on human health, performance and well being has been investigated from the view point of the effects of microgravity (during space travel), reduced gravity (on the Moon) and abrupt gravity changes (during launch and landing), of the effects of cosmic radiation including solar particle events, of psychological issues as well as general health care. Countermeasures as well as necessary research using ground- based testbeds and/or the ISS have been defined. The need for highly intelligent autonomous diagnostic and therapy systems was considered as a driver also for terrestrial applications. Likewise advanced life support systems with a high degree of autonomy and regenerative capacity and synergy effects were considered where bioregenerative life support systems and biodiagnistic systems become essential especially for the long-term Mars scenario. A roadmap for a future European strategy leading to a potential European participation in a cooperative human exploratory mission, either to the Moon or to Mars, was produced. Ref. Horneck et al. HUMEX, study on the Survivability and Adaptation of Humans to Long-Duration Exploratory Missions, ESA SP (in press)

  12. Anticipated significant work limitation in primary care consulters with osteoarthritis: a prospective cohort study

    PubMed Central

    Wilkie, Ross; Phillipson, Chris; Hay, Elaine M; Pransky, Glenn

    2014-01-01

    Objective To describe the prevalence of expected work limitations (EWL) prior to future retirement age in osteoarthritis consulters, and the associated health, sociodemographic and workplace factors. Design Population-based prospective cohort study. Setting General practices in Staffordshire, England. Participants 297 working adults aged 50–65, who had consulted primary care for osteoarthritis. Outcome EWL was defined using a single question, “Do you think joint pain will limit your ability to work before you reach 69?years old?” Results 51 (17.2%) indicated that joint pain would not limit their ability to work until 69, 79 (26.6%) indicated EWL and 167 (56.2%) did not know if joint pain would limit work before 69. In bivariate analysis, physical function (OR 0.93; 95% CI 0.91 to 0.96), depression (4.51; 1.81 to 11.3), cognitive symptom (3.84; 1.81 to 8.18), current smoker (2.75; 1.02 to 7.38), age (0.69; 0.58 to 0.82), physically demanding job (3.18; 1.50 to 6.72), no opportunities to retrain (3.01; 1.29 to 7.05) and work dissatisfaction (3.69; 1.43 to 9.49) were associated with EWL. The final multivariate model included physical function and age. Conclusions Only one in five osteoarthritis consulters expected that joint pain would not limit their work participation before 69?years of age. Given the expectation for people to work until they are older, the results highlight the increasing need for clinicians to include work participation in their consultation and implement strategies to address work loss/limitation. Targeting pain-related functional limitation and effective communication with employers to manage workplace issues could reduce EWL. PMID:25190616

  13. RESEARCH ASSISTANT POSITION NEUROPSYCHOLOGICAL STUDIES OF HUMAN MEMORY

    E-print Network

    Patel, Aniruddh D.

    RESEARCH ASSISTANT POSITION NEUROPSYCHOLOGICAL STUDIES OF HUMAN MEMORY The Boston University Memory in cognitive psychology, cognitive neuroscience, or related field to serve as a full-time research assistant: assisting in the design and development of experiments; recruiting and scheduling research participants

  14. Asian Studies The School of Humanities and the School of

    E-print Network

    Richards-Kortum, Rebecca

    99 Asian Studies The School of Humanities and the School of Social Sciences DIRECTOR Steven W Ludwig Marshall McArthur E.Douglas Mitchell Nam Van Nguyen Chao-Mei Shen MengYeh Degree Offered: BA Asian and achievements of Asian civilizations but also on the ways an understanding of Asia may shed new light on Western

  15. Human Exposures to PAHs: an Eastern United States Pilot Study

    EPA Science Inventory

    Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD and in four surrounding counties (NHEXAS-Maryland). An objective of this effort was to esta...

  16. Human volunteer study with PGME: eye irritation during vapour exposure

    Microsoft Academic Search

    H. H Emmen; H Muijser; J. H. E Arts; M. K Prinsen

    2003-01-01

    The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated measures design. Each subject was exposed for 2.5 h to each of the

  17. Molecular methods for studying methanogens of the human gastrointestinal tract: current status and future directions.

    PubMed

    Chaudhary, Prem Prashant; Gaci, Nadia; Borrel, Guillaume; O'Toole, Paul W; Brugère, Jean-François

    2015-07-01

    Until recently, human gut microbiota was believed to be colonized by few methanogenic archaeal species. Much higher microbial diversity within the human gut was revealed by the use of molecular approaches as compared to routine microbiological techniques, but still, a lot remains unknown. Molecular techniques has the advantage of being rapid, reproducible, and can be highly discriminative as compared to conventional culturing methods. Some of them provide both qualitative and quantitative information. However, the choice of method should be taken with care to avoid biases. The advent of next-generation sequencing gives much deeper information from which functional and ecological hypotheses can be drawn. In this review, molecular techniques that are currently used together with their possible future developments to study gut methanogenic communities are indicated along with their limitations and difficulties that are encountered during their implementation. Moreover, the high amount of metagenomics data from the human gut microbiome indicate that this environment could be a paradigm for new directions in methanogen diversity studies and help to develop new approaches for other environments as well. Concerning humans, this should help us to better understand the possible association of methanogens with some of the diseased conditions and their peculiar distribution among age groups in human. PMID:26088176

  18. A rate code for sound azimuth in monkey auditory cortex: implications for human neuroimaging studies

    PubMed Central

    Werner-Reiss, Uri; Groh, Jennifer M.

    2013-01-01

    Is sound location represented in the auditory cortex of humans and monkeys? Human neuroimaging experiments have had only mixed success at demonstrating sound location sensitivity in primary auditory cortex. This is in apparent conflict with studies in monkeys and other animals, where single-unit recording studies have found stronger evidence for spatial sensitivity. Does this apparent discrepancy reflect a difference between humans and animals, or does it reflect differences in the sensitivity of the methods used for assessing the representation of sound location? The sensitivity of imaging methods such as fMRI depends on two key aspects of the underlying neuronal population: (1) what kind of spatial sensitivity individual neurons exhibit, and (2) whether neurons with similar response preferences are clustered within the brain. To address this question, we conducted a single unit recording study in monkeys. We investigated the nature of spatial sensitivity in individual auditory cortical neurons to determine whether they have receptive fields (place code) or monotonic (rate code) sensitivity to sound azimuth. Secondly, we tested how strongly the population of neurons favors contralateral locations. We report here that the majority of neurons show predominantly monotonic azimuthal sensitivity, forming a rate code for sound azimuth, but that at the population level the degree of contralaterality is modest. This suggests that the weakness of the evidence for spatial sensitivity in human neuroimaging studies of auditory cortex may be due to limited lateralization at the population level, despite what may be considerable spatial sensitivity in individual neurons. PMID:18385333

  19. Engineered human vaccines

    SciTech Connect

    Sandhu, J.S. (Mount Sinai Hospital, Toronto, Ontario (Canada). Div. of Immunology and Neurobiology)

    1994-01-01

    The limitations of human vaccines in use at present and the design requirements for a new generation of human vaccines are discussed. The progress in engineering of human vaccines for bacteria, viruses, parasites, and cancer is reviewed, and the data from human studies with the engineered vaccines are discussed, especially for cancer and AIDS vaccines. The final section of the review deals with the possible future developments in the field of engineered human vaccines and the requirement for effective new human adjuvants.

  20. Simplified detection system for neuroreceptor studies in the human brain

    SciTech Connect

    Bice, A.N.; Wagner, H.N. Jr.; Frost, J.J.; Natarajan, T.K.; Lee, M.C.; Wong, D.F.; Dannals, R.F.; Ravert, H.T.; Wilson, A.A.; Links, J.M.

    1986-02-01

    A simple, inexpensive dual-detector system has been developed for measurement of positronemitting receptor-binding drugs in the human brain. This high efficiency coincidence counting system requires that only a few hundred microcuries of labeled drug be administered to the subject, thereby allowing for multiple studies without an excessive radiation dose. Measurement of the binding of (11C)carfentanil, a high affinity synthetic opiate, to opiate receptors in the presence and in the absence of a competitive opiate antagonist indicates the potential utility of this system for estimating different degrees of receptor occupation in the human brain.

  1. UH Human Studies Program Policies and Procedures Page 1 University of Hawai`i

    E-print Network

    Olsen, Stephen L.

    UH Human Studies Program Policies and Procedures Page 1 University of Hawai`i Human Studies Program General Policies and Procedures UH Human Studies Program 1960 East-West Road Biomedical Building B-104 Honolulu, HI 96822 Revised April 3, 2012 #12;UH Human Studies Program Policies and Procedures Page 2 UH

  2. Advantages and limitations of the use of optogenetic approach in studying fast-scale spike encoding.

    PubMed

    Malyshev, Aleksey; Goz, Roman; LoTurco, Joseph J; Volgushev, Maxim

    2015-01-01

    Understanding single-neuron computations and encoding performed by spike-generation mechanisms of cortical neurons is one of the central challenges for cell electrophysiology and computational neuroscience. An established paradigm to study spike encoding in controlled conditions in vitro uses intracellular injection of a mixture of signals with fluctuating currents that mimic in vivo-like background activity. However this technique has two serious limitations: it uses current injection, while synaptic activation leads to changes of conductance, and current injection is technically most feasible in the soma, while the vast majority of synaptic inputs are located on the dendrites. Recent progress in optogenetics provides an opportunity to circumvent these limitations. Transgenic expression of light-activated ionic channels, such as Channelrhodopsin2 (ChR2), allows induction of controlled conductance changes even in thin distant dendrites. Here we show that photostimulation provides a useful extension of the tools to study neuronal encoding, but it has its own limitations. Optically induced fluctuating currents have a low cutoff (~70 Hz), thus limiting the dynamic range of frequency response of cortical neurons. This leads to severe underestimation of the ability of neurons to phase-lock their firing to high frequency components of the input. This limitation could be worked around by using short (2 ms) light stimuli which produce membrane potential responses resembling EPSPs by their fast onset and prolonged decay kinetics. We show that combining application of short light stimuli to different parts of dendritic tree for mimicking distant EPSCs with somatic injection of fluctuating current that mimics fluctuations of membrane potential in vivo, allowed us to study fast encoding of artificial EPSPs photoinduced at different distances from the soma. We conclude that dendritic photostimulation of ChR2 with short light pulses provides a powerful tool to investigate population encoding of simulated synaptic potentials generated in dendrites at different distances from the soma. PMID:25850004

  3. Prolonged use of aspirin alters human and rat intestinal cells and thereby limits the absorption of clopidogrel.

    PubMed

    Jung, K-H; Chu, K; Lee, S-T; Yoon, H-J; Chang, J-Y; Nam, W-S; Yoon, S-H; Cho, J-Y; Yu, K-S; Jang, I-J; Kim, M; Lee, S K; Roh, J-K

    2011-10-01

    Clopidogrel therapy to prevent atherothrombosis faces the challenge of reduced responsiveness. The absorption of clopidogrel is regulated by multidrug-resistance protein 1 (MDR1) in the intestinal epithelium. Given that aspirin induces MDR1 in cancer cells and peripheral blood cells, it may induce MDR1 in intestinal epithelial cells as well, thereby affecting the absorption of clopidogrel. In this study, aspirin treatment induced the expression of MDR1 in human epithelial colorectal (Caco-2) cells in vitro and in rat intestine in vivo, as evidenced by dose-dependent increases in gene, protein, and efflux function. Along with the upregulation of MDR1 proteins by aspirin, clopidogrel absorption was significantly decreased in the aspirin-treated Caco-2 cells and in rat intestine. Our data provide evidence that prolonged use of aspirin may reduce the intestinal absorption of clopidogrel. Further human studies would be necessary to clarify whether these data have any relevance to prevention of stroke or myocardial infarction. PMID:21900887

  4. New humanized mouse model of bronchiolitis obliterans syndrome.

    PubMed

    Anegon, Ignacio

    2015-03-01

    Humanized animals are transplanted with human tissues and cells to study their behavior as they do in the human body. This commentary briefly summarizes the recent developments and discusses the limitations of these humanized animal models. PMID:25695785

  5. American Studies: Humanities. Curriculum Study and Improvement Project.

    ERIC Educational Resources Information Center

    1971

    Designed for eleventh grade students, this guide incorporates the four disciplines of art, music, literature, and history. The objectives are for students to apply knowledge gained from the study of past problems toward the problems of contemporary society; to develop an understanding of cultural and societal patterns; to trace personal values of…

  6. Complete nucleotide sequence, genome organization, and biological properties of human immunodeficiency virus type 1 in vivo: evidence for limited defectiveness and complementation.

    PubMed Central

    Li, Y; Hui, H; Burgess, C J; Price, R W; Sharp, P M; Hahn, B H; Shaw, G M

    1992-01-01

    Previous studies of the genetic and biologic characteristics of human immunodeficiency virus type 1 (HIV-1) have by necessity used tissue culture-derived virus. We recently reported the molecular cloning of four full-length HIV-1 genomes directly from uncultured human brain tissue (Y. Li, J. C. Kappes, J. A. Conway, R. W. Price, G. M. Shaw, and B. H. Hahn, J. Virol. 65:3973-3985, 1991). In this report, we describe the biologic properties of these four clones and the complete nucleotide sequences and genome organization of two of them. Clones HIV-1YU-2 and HIV-1YU-10 were 9,174 and 9,176 nucleotides in length, differed by 0.26% in nucleotide sequence, and except for a frameshift mutation in the pol gene in HIV-1YU-10, contained open reading frames corresponding to 5'-gag-pol-vif-vpr-tat-rev-vpu-env-nef-3' flanked by long terminal repeats. HIV-1YU-2 was fully replication competent, while HIV-1YU-10 and two other clones, HIV-1YU-21 and HIV-1YU-32, were defective. All three defective clones, however, when transfected into Cos-1 cells in any pairwise combination, yielded virions that were replication competent and transmissible by cell-free passage. The cellular host range of HIV-1YU-2 was strictly limited to primary T lymphocytes and monocyte-macrophages, a property conferred by its external envelope glycoprotein. Phylogenetic analyses of HIV-1YU-2 gene sequences revealed this virus to be a member of the North American/European HIV-1 subgroup, with specific similarity to other monocyte-tropic viruses in its V3 envelope amino acid sequence. These results indicate that HIV-1 infection of brain is characterized by the persistence of mixtures of fully competent, minimally defective, and more substantially altered viral forms and that complementation among them is readily attainable. In addition, the limited degree of genotypic heterogeneity observed among HIV-1YU and other brain-derived viruses and their preferential tropism for monocyte-macrophages suggest that viral replication within the central nervous system may differ from that within the peripheral lymphoid compartment in significant and clinically important ways. The availability of genetically and biologically well characterized HIV-1 clones from uncultured human tissue should facilitate future studies of virus-cell interactions relevant to viral pathogenesis and drug and vaccine development. Images PMID:1404605

  7. Study of ultrasonic attenuation in f-electron systems in the paramagnetic limit of Coulomb interaction

    NASA Astrophysics Data System (ADS)

    Shadangi, Asit Ku.; Rout, G. C.

    2015-05-01

    We report here a microscopic model study of ultrasonic attenuation in f-electron systems based on Periodic Anderson Model in which Coulomb interaction is considered within a mean-field approximation for a weak interaction. The Phonon is coupled to the conduction band and f-electrons. The phonon Green's function is calculated by Zubarev's technique of the Green's function method. The temperature dependent ultrasonic attenuation co-efficient is calculated from the imaginary part of the phonon self-energy in the dynamic and long wave length limit. The f-electron occupation number is calculated self-consistently in paramagnetic limit of Coulomb interaction. The effect of the Coulomb interaction on ultrasonic attenuation is studied by varying the phonon coupling parameters to the conduction and f-electrons, hybridization strength, the position of f-level and the Coulomb interaction Strength. Results are discussed on the basis of experimental results.

  8. Multiyear Study of Pollen Limitation and Cost of Reproduction in the Iteroparous Silene Virginica

    Microsoft Academic Search

    Michele R. Dudash; Charles B. Fenster

    1997-01-01

    We investigated whether pollen deposited onto stigmas limited female re- productive success in the hummingbird-pollinated, short-lived, iteroparous, Silene virginica (Caryophyllaceae). The study was conducted over a 4-yr span in a population occurring in a woodland area and over a 3-yr span in a second population occurring in a nearby open meadow. We contrasted average fruit set, seed set per fruit,

  9. A YBCO-coated conductor for a fault current limiter: architecture influences and optical study

    Microsoft Academic Search

    N. T. Nguyen; P. Tixador

    2010-01-01

    YBaCuO-coated conductors (CC) are particularly interesting for the electric grid, especially for superconducting (SC) fault current limiters (FCL). This innovative device should play an important part in the future electric energy landscape. New network diagrams are indeed imagined with DC buses. The SC FCL would solve the delicate problem of DC fault currents. We have studied several YBaCuO-coated conductors with

  10. Exploring the Limits of Trigonometric Functions: Results and Reflections from a Pilot Study

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong; Poon, Kin-Keung

    2014-01-01

    In this paper, we report a pilot study on engaging a group of undergraduate students to explore the limits of sin(x)/x and tan(x)/x as x approaches to 0, with the use of non-graphic scientific calculators. By comparing the results in the pretest and the post-test, we found that the students had improvements in the tested items, which involved the…

  11. Estimation of human maximum tolerable intake for methylmercury based on two recent studies in monkeys.

    PubMed

    Yamamoto, Ryoji; Shima, Masayuki

    2009-12-01

    Results of long-term toxicity studies of methylmercury (MeHg) in monkeys have been reported. The aim of this study was to estimate the threshold body burden, blood level and threshold daily intake (TDI) of MeHg for monkey and human. The concepts of this study stood on that body burden of MeHg would follow the accumulation theory, and that the more intake of MeHg, the earlier the neurotoxicity appeared, vice versa. The threshold blood level (TBL) of monkey was estimated to be 0.71 as Hg mg/L and the body burden was estimated to be 4.83 as Hg mg/kg. The TDI was estimated to be 0.025 as Hg mg/kg day. In human, the TBL was estimated with compensation by elimination constants of human and monkey. The blood threshold limit and TDI of human were estimated to be 0.33 as Hg mg/L and 0.0046 as Hg mg/kg day, respectively. The estimated body burden was 0.46 as Hg mg/kg. PMID:19582434

  12. Framework for Human-Automation Collaboration: Conclusions from Four Studies

    SciTech Connect

    Johanna Oxstrand; Katya L. Le Blanc; John O'Hara; Jeffrey C. Joe; April M. Whaley; Heather Medema

    2013-11-01

    The Human Automation Collaboration (HAC) research project is investigating how advanced technologies that are planned for Advanced Small Modular Reactors (AdvSMR) will affect the performance and the reliability of the plant from a human factors and human performance perspective. The HAC research effort investigates the consequences of allocating functions between the operators and automated systems. More specifically, the research team is addressing how to best design the collaboration between the operators and the automated systems in a manner that has the greatest positive impact on overall plant performance and reliability. Oxstrand et al. (2013 - March) describes the efforts conducted by the researchers to identify the research needs for HAC. The research team reviewed the literature on HAC, developed a model of HAC, and identified gaps in the existing knowledge of human-automation collaboration. As described in Oxstrand et al. (2013 – June), the team then prioritized the research topics identified based on the specific needs in the context of AdvSMR. The prioritization was based on two sources of input: 1) The preliminary functions and tasks, and 2) The model of HAC. As a result, three analytical studies were planned and conduced; 1) Models of Teamwork, 2) Standardized HAC Performance Measurement Battery, and 3) Initiators and Triggering Conditions for Adaptive Automation. Additionally, one field study was also conducted at Idaho Falls Power.

  13. Lost in Virtual Space: Studies in Human and Ideal Spatial Navigation

    ERIC Educational Resources Information Center

    Stankiewicz, Brian J.; Legge, Gordon E.; Mansfield, J. Stephen; Schlicht, Erik J.

    2006-01-01

    The authors describe 3 human spatial navigation experiments that investigate how limitations of perception, memory, uncertainty, and decision strategy affect human spatial navigation performance. To better understand the effect of these variables on human navigation performance, the authors developed an ideal-navigator model for indoor navigation…

  14. A validation study of a stochastic model of human interaction

    NASA Astrophysics Data System (ADS)

    Burchfield, Mitchel Talmadge

    The purpose of this dissertation is to validate a stochastic model of human interactions which is part of a developmentalism paradigm. Incorporating elements of ancient and contemporary philosophy and science, developmentalism defines human development as a progression of increasing competence and utilizes compatible theories of developmental psychology, cognitive psychology, educational psychology, social psychology, curriculum development, neurology, psychophysics, and physics. To validate a stochastic model of human interactions, the study addressed four research questions: (a) Does attitude vary over time? (b) What are the distributional assumptions underlying attitudes? (c) Does the stochastic model, {-}N{intlimitssbsp{-infty}{infty}}varphi(chi,tau)\\ Psi(tau)dtau, have utility for the study of attitudinal distributions and dynamics? (d) Are the Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein theories applicable to human groups? Approximately 25,000 attitude observations were made using the Semantic Differential Scale. Positions of individuals varied over time and the logistic model predicted observed distributions with correlations between 0.98 and 1.0, with estimated standard errors significantly less than the magnitudes of the parameters. The results bring into question the applicability of Fisherian research designs (Fisher, 1922, 1928, 1938) for behavioral research based on the apparent failure of two fundamental assumptions-the noninteractive nature of the objects being studied and normal distribution of attributes. The findings indicate that individual belief structures are representable in terms of a psychological space which has the same or similar properties as physical space. The psychological space not only has dimension, but individuals interact by force equations similar to those described in theoretical physics models. Nonlinear regression techniques were used to estimate Fermi-Dirac parameters from the data. The model explained a high degree of the variance in each probability distribution. The correlation between predicted and observed probabilities ranged from a low of 0.955 to a high value of 0.998, indicating that humans behave in psychological space as Fermions behave in momentum space.

  15. Novel approaches to study the involvement of ?7-nAChR in human diseases.

    PubMed

    Palma, Eleonora; Conti, Luca; Roseti, Cristina; Limatola, Cristina

    2012-05-01

    The alpha7 nicotinic acetylcholine receptor (?7 nAChR) is widely distributed in the human brain and has been implicated in a number of human central nervous system (CNS) diseases, including Alzheimer's and Parkinson's disease, schizophrenia and autism. Recently, new roles for ?7 nAChRs in lung cancer and heart disease have been elucidated. Despite the importance of this receptor in human pathology, many technical difficulties are still encountered when investigating the role of ?7 nAChRs. Electrophysiological analysis of the receptor upon heterologous expression or in human tissues was limited by the fast desensitization of ?7-mediated nicotinic currents and by tissue availability. In addition, animal models for the human diseases related to ?7 nAChRs have long been unavailable. The recent development of new imaging and analysis approaches such as PET and receptor microtransplantation have rendered the study of ?7 nAChRs increasingly feasible, paving new roads to the design of therapeutic drugs. This review summarizes the current knowledge and recent findings obtained by these novel approaches. PMID:22300023

  16. Advancing the management and control of typhoid fever: a review of the historical role of human challenge studies.

    PubMed

    Waddington, Claire S; Darton, Thomas C; Woodward, William E; Angus, Brian; Levine, Myron M; Pollard, Andrew J

    2014-05-01

    Typhoid infection causes considerable morbidity and mortality worldwide, particularly in settings where lack of clean water and inadequate sanitation facilitate disease spread through faecal-oral transmission. Improved understanding of the pathogenesis, immune control and microbiology of Salmonella Typhi infection can help accelerate the development of improved vaccines and diagnostic tests necessary for disease control. S. Typhi is a human-restricted pathogen; therefore animal models are limited in their relevance to human infection. During the latter half of the 20th century, induced human infection ("challenge") studies with S. Typhi were used effectively to assess quantitatively the human host response to challenge and to measure directly the efficacy of typhoid vaccines in preventing clinical illness. Here, the findings of these historic challenge studies are reviewed, highlighting the pivotal role that challenge studies have had in improving our understanding of the host-pathogen interaction, and illustrating issues relevant to modern typhoid challenge model design. PMID:24491597

  17. A Quantitative Analysis of Rate-limiting Steps in the Metastatic Cascade Using Human-specific Real-Time Polymerase Chain Reaction1

    Microsoft Academic Search

    Andries Zijlstra; Rebecca Mellor; Giano Panzarella; Ronald T. Aimes; John D. Hooper; Natalia D. Marchenko; James P. Quigley

    2002-01-01

    A quantitative assessment of rate-limiting steps in metastasis has al- ways been challenging because of the difficulty of detecting small tumor cell populations. We have developed a highly sensitive assay for monitor- ing the metastatic dissemination of human tumor cells in the chick embryo and used this assay to investigate the relative efficacy of sequential stages in the metastatic cascade

  18. 40 CFR 26.1603 - Operation of the Human Studies Review Board.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Operation of the Human Studies Review Board. 26.1603 Section...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and Completed Human Research § 26.1603 Operation of...

  19. Communication Through Physical Interaction: A Study of Human Collaborative Manipulation of a Planar Object

    E-print Network

    progress towards understanding human communication through physical inter- action. We describe improves the understanding of language. Learning from humans is one of the prevailing paradigmsCommunication Through Physical Interaction: A Study of Human Collaborative Manipulation of a Planar

  20. A critical review of epidemiologic studies of radiofrequency exposure and human cancers.

    PubMed Central

    Elwood, J M

    1999-01-01

    This paper reviews studies that have assessed associations between likely exposure to radiofrequency (RF) transmissions and various types of human cancer. These studies include three cluster investigations and five studies relating to general populations; all of these studies consider place of residence at the time of cancer diagnosis in regard to proximity to radio or television transmitters. There are also five relevant occupational cohort studies and several case-control studies of particular types of cancer. These studies assessed a large number of possible associations. Several positive associations suggesting an increased risk of some types of cancer in those who may have had greater exposure to RF emissions have been reported. However, the results are inconsistent: there is no type of cancer that has been consistently associated with RF exposures. The epidemiologic evidence falls short of the strength and consistency of evidence that is required to come to a reasonable conclusion that RF emissions are a likely cause of one or more types of human cancer. The evidence is weak in regard to its inconsistency, the design of the studies, the lack of detail on actual exposures, and the limitations of the studies in their ability to deal with other likely relevant factors. In some studies there may be biases in the data used PMID:10229715

  1. Study of Light Scattering in the Human Eye

    NASA Astrophysics Data System (ADS)

    Perez, I. Kelly; Bruce, N. C.; Valdos, L. R. Berriel

    2008-04-01

    In this paper we present a numerical model of the human eye to be used in studies of the scattering of light in different components of the eye's optical system. Different parts of the eye are susceptible to produce scattering for different reasons; age, illness or injury. For example, cataracts can appear in the human lens or injuries or fungi can appear on the cornea. The aim of the study is to relate the backscattered light, which is what doctors measure or detect, to the forward scattered light, which is what affects the patient's vision. We present the model to be used, the raytrace procedure and some preliminary results for the image on the retina without scattering.

  2. Determination of Actarit from Human Plasma for Bioequivalence Studies

    PubMed Central

    Loya, P.; Saraf, M. N.

    2010-01-01

    An analytical method based on high-performance liquid chromatography with ultraviolet detection (245 nm) was developed for the determination of actarit in human plasma. Coumarin was used as an internal standard. Chromatographic separation was achieved with a C8 column using a mobile phase of methanol: 1% acetic acid (50-50, v/v) with a flow rate of 1.0 ml/min. The calibration curve was linear over the range of 0.1–4.0 ?g/ml (r2 > 0.99) and the lower limit of quantification was 0.1 ?g/ml. The method was validated for sensitivity, accuracy, precision, recovery and stability. The method was used to determine the concentration-time profiles of actarit in the plasma following oral administration of 100 mg actarit tablets. PMID:21969744

  3. Raman microspectroscopic approach to the study of human granulocytes.

    PubMed Central

    Puppels, G J; Garritsen, H S; Segers-Nolten, G M; de Mul, F F; Greve, J

    1991-01-01

    A sensitive confocal Raman microspectrometer was employed to record spectra of nuclei and cytoplasmic regions of single living human granulocytes. Conditions were used that ensured cell viability and reproducibility of the spectra. Identical spectra were obtained from the nuclei of neutrophilic, eosinophilic, and basophilic granulocytes, which yield information about DNA and protein secondary structure and DNA-protein ratio. The cytoplasmic Raman spectra of the three cell types are very different. This was found to be mainly due to the abundant presence of peroxidases in the cytoplasmic granules of neutrophilic granulocytes (myeloperoxidase) and eosinophilic granulocytes (eosinophil peroxidase). Strong signal contributions of the active site heme group(s) of these enzymes were found. This paper illustrates the potentials and limitations for Raman spectroscopic analysis of cellular constituents and processes. PMID:1760504

  4. Establishment of a Reverse Genetics System for Studying Human Bocavirus in Human Airway Epithelia

    PubMed Central

    Cheng, Fang; Luo, Yong; Shen, Weiran; Lei-Butters, Diana C. M.; Chen, Aaron Yun; Li, Yi; Tang, Liang; Söderlund-Venermo, Maria; Engelhardt, John F.; Qiu, Jianming

    2012-01-01

    Human bocavirus 1 (HBoV1) has been identified as one of the etiological agents of wheezing in young children with acute respiratory-tract infections. In this study, we have obtained the sequence of a full-length HBoV1 genome (including both termini) using viral DNA extracted from a nasopharyngeal aspirate of an infected patient, cloned the full-length HBoV1 genome, and demonstrated DNA replication, encapsidation of the ssDNA genome, and release of the HBoV1 virions from human embryonic kidney 293 cells. The HBoV1 virions generated from this cell line-based production system exhibits a typical icosahedral structure of approximately 26 nm in diameter, and is capable of productively infecting polarized primary human airway epithelia (HAE) from the apical surface. Infected HAE showed hallmarks of lung airway-tract injury, including disruption of the tight junction barrier, loss of cilia and epithelial cell hypertrophy. Notably, polarized HAE cultured from an immortalized airway epithelial cell line, CuFi-8 (originally derived from a cystic fibrosis patient), also supported productive infection of HBoV1. Thus, we have established a reverse genetics system and generated the first cell line-based culture system for the study of HBoV1 infection, which will significantly advance the study of HBoV1 replication and pathogenesis. PMID:22956907

  5. Vascularization of Developing Human Olfactory Neuroepithelium – A Morphometric Study

    Microsoft Academic Search

    S. K. Sangari; P. Sengupta; S. Pradhan; K. Khatri

    2000-01-01

    The present study reveals intraepithelial capillaries in the olfactory neuroepithelium of human fetuses aged between 12 and 24 weeks of gestation, which disappear at birth. The area occupied by the intraepithelial capillaries increases significantly with fetal age (0.047 ± 0.014 ?m2\\/?m2 at 12 weeks and 0.101 ± 0.025 ?m2\\/?m2 at 24 weeks) and with the thickness of the epithelium (45.00

  6. Fatty acid metabolism studies of human epidermal cell cultures

    Microsoft Academic Search

    Cynthia L. Marcelo; William R. Dunham

    Adult human epidermal keratinocytes grow rapidly in medium that is essential fatty acid (EFA)-deficient. In this medium they exhibit decreased amounts of the fatty acids, 18:2, 20:3, 20:4, and contain increased amounts of monounsaturated fatty acids. (I%)- and (SHIacetate and radiolabeled fatty acids, 16:0, 18:2, and 20:4 were used to study the fatty acid metabolism of these cells. Label from

  7. Human colonic biota studied by ribosomal DNA sequence analysis

    Microsoft Academic Search

    KENNETH H. WILSON; R. B. Blitchington

    1996-01-01

    Human colonic biota is a complex microbial ecosystem that serves as a host defense. Unlike most microbial ecosystems, its composition has been studied extensively by relatively efficient culture methods. We have compared an established culture-based method with direct amplification and partial sequencing of cloned 16S rRNAgenesfromahumanfecalspecimen.NinecyclesofPCRwerealsocomparedwith35cycles.Coloniesand clonedampliconswereclassifiedbycomparingtheirribosomalDNA(rDNA;DNAcodingforrRNA)sequences with rDNA sequences of known phylogeny. Quantitative culture recovered 58% of the microscopic

  8. Studies of WW and WZ Production and Limits on Anomalous WWgamma and WWZ Couplings

    E-print Network

    D0 Collaboration

    1999-05-04

    Evidence of anomalous WW and WZ production was sought in pbar{p} collisions at a center-of-mass energy of sqrt(s) = 1.8 TeV. The final states $WW (WZ) to mu-nu-jet-jet + X, WZ to mu-nu-e-e + X and WZ to e-nu-e-e + X were studied using a data sample corresponding to an integrated luminosity of approximately 90 pb-1. No evidence of anomalous diboson production was found. Limits were set on anomalous WWgamma and WWZ couplings and were combined with our previous results. The combined 95% confidence level anomalous coupling limits for Lambda=2 TeV are -0.25 LE Delta-kappa LE 0.39 (lambda=0) and -0.18 LE lambda LE 0.19 (Delta \\kappa = 0), assuming the WWgamma couplings are equal to the WWZ couplings.

  9. Relevance of using a human microarray to study gene expression in heaves-affected horses.

    PubMed

    Ramery, Eve; Closset, Rodrigue; Bureau, Fabrice; Art, Tatiana; Lekeux, Pierre

    2008-08-01

    Environmental causes of heaves are well described, but the molecular mechanisms of the disease remain unclear. Previous studies have highlighted the implications of variations in gene expression, most using reverse transcription polymerase chain reaction (RT-PCR). This well-known technique limits the number of genes that can be studied in a single assay. Microarray appears to be a valuable tool to by-pass this limitation, but so far there has been no equine-specific microarray available on the market. The present study was performed to determine whether a human microarray could be used to study gene expression in nucleated cells originating from peripheral blood and bronchoalveolar lavage fluid (BALF) in heaves-affected horses. With a four-fold cut-off, a total of 46 candidates were identified with differentially regulated genes between heaves-affected horses and controls. A real-time quantitative RT-PCR (RT-QPCR) conducted on a selection of genes, determined on the basis of previous publications, was used to validate the microarray results. The microarray failed to detect the presence of interleukin (IL)-1beta and IL-8 mRNA in the nucleated cells from BALF otherwise confirmed by real-time RT-QPCR. Although some candidate genes have been identified using this method, a complete expression profile of genes related to heaves could not be obtained with the use of the human microarray. PMID:17574458

  10. The photochemistry of human retinal lipofuscin as studied by EPR.

    PubMed

    Reszka, K; Eldred, G E; Wang, R H; Chignell, C; Dillon, J

    1995-12-01

    Fluorescent material generated in the human retina accumulates within lipofuscin (HLF) granules of the retinal pigment epithelium (RPE) during aging. We have been investigating the possible light-induced contribution of these fluorophores to various diseases including age-related macular degeneration. Our studies have shown that some of the fluorescent components of HLF are products of the reaction of retinaldehyde with ethanolamine and that synthetic mixtures of this reaction can serve as a useful model for photophysical studies. Previous research by us has demonstrated that irradiation of either natural or synthetic lipofuscin resulted in the formation of a triplet state and possibly a free radical. Here EPR studies were performed to verify the formation of that radical. The UV irradiation of either synthetic or natural human retinal lipofuscin extracts in oxygen-free methanol led to the formation of a 5,5-dimethylpyrroline-N-oxide (DMPO) spin-trapped carbon-centered radical resulting from either hydrogen atom or electron abstraction from solvent molecules. In the presence of oxygen superoxide was formed, which was observed as a DMPO adduct. It is concluded that certain components of the chloroform-soluble fluorophores of human RPE lipofuscin granules and the fluorescent reaction products of retinaldehyde and ethanolamine are photophysically similar but not the same. Electron or hydrogen abstraction from a substrate by these fluorophores in vivo and the resulting radical products may contribute to the age-related decline of RPE function and blue light damage in the retina. PMID:8570736

  11. Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System

    PubMed Central

    Goss, David A.; Hoffman, Richard L.; Clark, Brian C.

    2012-01-01

    Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade. While the use of TMS has expanded to the study of many systems and processes during this time, the original application and perhaps one of the most common uses of TMS involves studying the physiology, plasticity and function of the human neuromuscular system. Single pulse TMS applied to the motor cortex excites pyramidal neurons transsynaptically 2 (Figure 1) and results in a measurable electromyographic response that can be used to study and evaluate the integrity and excitability of the corticospinal tract in humans 3. Additionally, recent advances in magnetic stimulation now allows for partitioning of cortical versus spinal excitability 4,5. For example, paired-pulse TMS can be used to assess intracortical facilitatory and inhibitory properties by combining a conditioning stimulus and a test stimulus at different interstimulus intervals 3,4,6-8. In this video article we will demonstrate the methodological and technical aspects of these techniques. Specifically, we will demonstrate single-pulse and paired-pulse TMS techniques as applied to the flexor carpi radialis (FCR) muscle as well as the erector spinae (ES) musculature. Our laboratory studies the FCR muscle as it is of interest to our research on the effects of wrist-hand cast immobilization on reduced muscle performance6,9, and we study the ES muscles due to these muscles clinical relevance as it relates to low back pain8. With this stated, we should note that TMS has been used to study many muscles of the hand, arm and legs, and should iterate that our demonstrations in the FCR and ES muscle groups are only selected examples of TMS being used to study the human neuromuscular system. PMID:22297466

  12. The safety of studies with intravenous ? 9 -tetrahydrocannabinol in humans, with case histories

    Microsoft Academic Search

    Michelle Carbuto; R. Andrew Sewell; Ashley Williams; Kim Forselius-Bielen; Gabriel Braley; Jacqueline Elander; Brian Pittman; Ashley Schnakenberg; Savita Bhakta; Edward Perry; Mohini Ranganathan; Deepak Cyril D’Souza

    Rationale  Delta-9-tetrahydrocannabinol (THC) is one of the few cannabinoid receptor ligands that can be used to probe the cannabinoid\\u000a system in humans. Despite increasing interest in the cannabinoid receptor system, use of intravenous THC as a research tool\\u000a has been limited by concerns about its abuse liability and psychoactive effects.\\u000a \\u000a \\u000a \\u000a \\u000a Objectives  This study aims to evaluate the safety of all intravenous THC

  13. A qualitative case study to identify possible barriers that limit effective elementary science education

    NASA Astrophysics Data System (ADS)

    Foster, Donald Carey

    The purpose of this case study was to identify barriers that limit the effectiveness of elementary teachers in the teaching of science. It is of the utmost urgency that barriers be first identified, so that possible solutions can be explored to bring about the improvement of elementary science education. This urgency has been imposed by the scheduled national testing of students in science by 2007, as mandated by the No Child Left Behind Act of 2001. Using qualitative case study methods, the researcher conducted interviews with 8 elementary teachers from two schools within one school district who taught 3rd, 4th, and 5th grade. These interviews were designed to gain insight into barriers these elementary teachers perceived as factors limiting their effectiveness in teaching science and preparing students for high-stakes testing. Barriers in the areas of teacher background, typical teaching day, curriculum, inservices, and legislative influences were explored. This study concluded that the barriers explored do have a substantial negative affect on the teaching and learning of science in the elementary grades. Specifically, the barriers revealed in this study include the limited science background of elementary teachers, inadequate class time devoted to science, non-comprehensive curriculum, ineffective or lack of inservice training, and pressures from legislated mandates. But it is also clear that these barriers are so intertwined that one cannot remove these barriers one at a time. It will take a collective effort from all involved, including legislators, administrators, teachers, parents, and students, to alleviate these barriers and discover effective solutions to improve elementary science education.

  14. Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance

    SciTech Connect

    Reginald M. Ronningen; Igor Remec

    2010-09-11

    Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.

  15. Development of a nude mouse model to study human sebaceous gland physiology and pathophysiology.

    PubMed Central

    Petersen, M J; Zone, J J; Krueger, G G

    1984-01-01

    Study of human sebaceous gland physiology and pathophysiology is limited by lack of an adequate animal model. This study was designed to develop an animal model using human face skin grafted onto the nude mouse to study human sebaceous glands. Full-thickness human face skin was grafted onto 60 adult male nude mice. 4 wk after grafting, androgens, which are known to stimulate sebaceous glands, were administered to test the system. Androgens were administered to 21 animals by implanted catheters that were filled with testosterone (T) or dihydrotestosterone (DHT). Empty catheters were implanted in 15 control animals. Graft biopsies and blood for androgen levels were obtained at time 1 (pre-catheter) and time 2 (26 d after catheter implantation). Three assessments were made on each biopsy: sebaceous gland volume, using an image analyzing computer; sebaceous cell size; and sebaceous gland labeling index. 29 mice completed the study through time 2. In the androgen-treated group, T levels (nanogram per milliliter) five times increased to 4.92 +/- 0.35, and DHT levels (nanogram per milliliter) increased 50 times to 16.70. In the androgen-treated group, sebaceous gland volume (micron 3 X 10(-3) increased from 896 +/- 194 to 3,233 +/- 754 (P less than 0.001), sebaceous cell area (micron 2) increased from 167 +/- 12 to 243 +/- 19 (P less than 0.001), and labeling index (percentage) increased from 2.7 +/- 0.7 to 6.4 +/- 0.9 (P less than 0.01). In the control group, sebaceous gland volume fell from 1,070 +/- 393 to 417 +/- 99 (NS), sebaceous cell size remained the same, and the labeling index fell from 5.1 +/- 1.9 to 3.2 +/- 1.1. After androgen administration, Halowax N-34, a known comedogen, or its vehicle, was applied to 15 grafts for 2-6 wk. Twice as many microcomedones were seen in the Halowax-treated grafts, compared with vehicle-treated grafts at the end of this time period. No visible comedones were produced. This study demonstrated that: (a) human sebaceous glands can be successfully transplanted and studied on the nude mouse; (b) after androgen stimulation, sebaceous gland volume, cell size, and labeling index increase; (c) microcomedones can be produced in the human skin grafts by the application of a comedogenic substance. Thus, this model demonstrates significant potential for the future study of human sebaceous gland physiology and pathology. Images PMID:6237122

  16. FT-Raman spectroscopy study of human breast tissue

    NASA Astrophysics Data System (ADS)

    Bitar Carter, Renata A.; Martin, Airton A.; Netto, Mario M.; Soares, Fernando A.

    2004-07-01

    Optical spectroscopy has been extensively studied as a potential in vivo diagnostic tool to provide information about the chemical and morphologic structure of tissue. Raman Spectroscpy is an inelastic scattering process that can provide a wealth of spectral features that can be related to the specific molecular structure of the sample. This article reports results of an in vitro study of the FT-Raman human breast tissue spectra. An Nd:YAG laser at 1064nm was used as the excitation source in the FT-Raman Spectrometer. The neoplastic human breast samples, both Fibroadenoma and ICD, were obtained during therapeutical routine medical procedures required by the primary disease, and the non-diseased human tissue was obtained in plastic surgery. No sample preparation was needed for the FT-Raman spectra collection. The FT-Raman spectra were recorded from normal, benign (Fibroadenomas) and malignant (IDC-Intraductal Carcinoma) samples, adding up 51 different areas. The main spectral differences of a typical FT-Raman spectra of a Normal (Non-diseased), Fibroadenoma, and Infiltrating Ductal Carcinoma (IDC) breast tissue at the interval of 600 to 1800cm-1, which may differentiate diagnostically the sample, were found in the bands of 1230 to 1295cm-1, 1440 to 1460 cm-1 and 1650 to 1680 cm-1, assigned to the vibrational bands of the carbohydrate-amide III, proteins and lipids, and carbohydrate-amide I, respectively.

  17. Insulin action in the human brain: evidence from neuroimaging studies.

    PubMed

    Kullmann, S; Heni, M; Fritsche, A; Preissl, H

    2015-06-01

    Thus far, little is known about the action of insulin in the human brain. Nonetheless, recent advances in modern neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG), have made it possible to investigate the action of insulin in the brain in humans, providing new insights into the pathogenesis of brain insulin resistance and obesity. Using MEG, the clinical relevance of the action of insulin in the brain was first identified, linking cerebral insulin resistance with peripheral insulin resistance, genetic predisposition and weight loss success in obese adults. Although MEG is a suitable tool for measuring brain activity mainly in cortical areas, fMRI provides high spatial resolution for cortical as well as subcortical regions. Thus, the action of insulin can be detected within all eating behaviour relevant regions, which include regions deeply located within the brain, such as the hypothalamus, midbrain and brainstem, as well as regions within the striatum. In this review, we outline recent advances in the field of neuroimaging aiming to investigate the action of insulin in the human brain using different routes of insulin administration. fMRI studies have shown a significant insulin-induced attenuation predominantly in the occipital and prefrontal cortical regions and the hypothalamus, successfully localising insulin-sensitive brain regions in healthy, mostly normal-weight individuals. However, further studies are needed to localise brain areas affected by insulin resistance in obese individuals, which is an important prerequisite for selectively targeting brain insulin resistance in obesity. PMID:25594822

  18. Design, recruitment, and microbiological considerations in human challenge studies.

    PubMed

    Darton, Thomas C; Blohmke, Christoph J; Moorthy, Vasee S; Altmann, Daniel M; Hayden, Frederick G; Clutterbuck, Elizabeth A; Levine, Myron M; Hill, Adrian V S; Pollard, Andrew J

    2015-07-01

    Since the 18th century a wealth of knowledge regarding infectious disease pathogenesis, prevention, and treatment has been accumulated from findings of infection challenges in human beings. Partly because of improvements to ethical and regulatory guidance, human challenge studies-involving the deliberate exposure of participants to infectious substances-have had a resurgence in popularity in the past few years, in particular for the assessment of vaccines. To provide an overview of the potential use of challenge models, we present historical reports and contemporary views from experts in this type of research. A range of challenge models and practical approaches to generate important data exist and are used to expedite vaccine and therapeutic development and to support public health modelling and interventions. Although human challenge studies provide a unique opportunity to address complex research questions, participant and investigator safety is paramount. To increase the collaborative effort and future success of this area of research, we recommend the development of consensus frameworks and sharing of best practices between investigators. Furthermore, standardisation of challenge procedures and regulatory guidance will help with the feasibility for using challenge models in clinical testing of new disease intervention strategies. PMID:26026195

  19. Simple instrument for biochemical studies of the living human brain

    SciTech Connect

    Bice, A.N.; Wagner, H.N. Jr.; Lee, M.C.; Frost, J.J.

    1986-09-01

    A simple, relatively inexpensive radiation detection system was developed for measurement of positron-emitting receptor-binding drugs in the human brain. This high-efficiency coincidence counting system requires that only a few hundred microcuries of labeled drug be administered to the subject, thereby allowing for multiple studies without an excessive radiation dose. Measurement of the binding of (/sup 11/C)-carfentanil, a high-affinity synthetic opiate, to opiate receptors in the presence and in the absence of a competitive opiate antagonist exemplifies the use of this system for estimating different degrees of receptor binding of drugs in the human brain. The instrument has also been used for measurement of the transport into the brain of other positron-emitting radiotracers, such as large neutral amino acids.

  20. A YBCO-coated conductor for a fault current limiter: architecture influences and optical study

    NASA Astrophysics Data System (ADS)

    Nguyen, N. T.; Tixador, P.

    2010-02-01

    YBaCuO-coated conductors (CC) are particularly interesting for the electric grid, especially for superconducting (SC) fault current limiters (FCL). This innovative device should play an important part in the future electric energy landscape. New network diagrams are indeed imagined with DC buses. The SC FCL would solve the delicate problem of DC fault currents. We have studied several YBaCuO-coated conductors with different architectures. A test bench for optical measurements has been developed to study the bubble development during limitation or over-current operation. The observations give useful information about the quench initiation and its propagation. The images were recorded every 0.2 ms (or less). Preliminary experiments have been carried out using a copper strip. Several operating temperatures have been investigated and important differences have been observed in some cases. The different YBaCuO CC studied show very different behaviours. Bubbles appear under the shape of strips across the tape or show a homogeneous behaviour. These behaviours are correlated by electrical measurements.

  1. The National Human Exposure Assessment Survey (NHEXAS) study in Arizona--introduction and preliminary results.

    PubMed

    Robertson, G L; Lebowitz, M D; O'Rourke, M K; Gordon, S; Moschandreas, D

    1999-01-01

    The objective of the National Human Exposure Assessment Survey (NHEXAS) in Arizona is to determine the multimedia distribution of total human exposure to environmental pollutants in the classes of metals, pesticides, and volatile organic compounds (VOCs) for the population of Arizona. This was accomplished by studying a probability-based sample of the total population in Arizona with a nested design for the different stages of sampling (954 Stage I, 505 Stage II, and 179 Stage III participants). This report compares the study population demographics with those from the U.S. Census and provides preliminary data on the distributions of the example pollutant for each class, lead for metals, chlorpyrifos for pesticides, and benzene for metals. The probability-based sample age and gender demographics compare reasonably well with the Census data (1990 Census and 1996 Census Estimate). The race/ethnicity compared less well with 21% Hispanics in the 1996 Census Estimate and 42% Hispanics in the entire NHEXAS-Arizona sample and 30% Hispanics as Stage III participants for this study. The chemical analyses of the various media (yard soil, foundation soil, house dust, indoor air, outdoor air, drinking water, food, and beverage) show generally low levels of the representative pollutants. The 50th percentiles of the distributions are generally near or below the analytical detection limits, and applicable Federal action limits were rarely exceeded. PMID:10554145

  2. Field theoretic study of a cold Fermi gas in the unitary limit

    NASA Astrophysics Data System (ADS)

    Wingate, Matthew

    2006-12-01

    Trapped and cooled gases of alkali atoms can be manipulated to exhibit a variety of interesting phenomena. For example, dilute gases of fermionic atoms, in 2 hyperfine states, can be cooled to temperatures where they become superfluid. An external field can be applied to tune the scat- tering length a. When |a| exceeds the interparticle spacing, nonperturbative tools are needed to study the system theoretically. The unitary limit, |a| ? ?, is particularly interesting due to its universality and symmetry. Lattice field theory and effective field theory can be used to system- atically calculate properties of this system. Results are presented for the finite temperature phase transition and for behavior near zero temperature.

  3. The Limit of Mechanical Stability in Quantum Crystals: A Diffusion Monte Carlo Study of Solid He

    NASA Astrophysics Data System (ADS)

    Cazorla, Claudio; Boronat, Jordi

    2015-07-01

    We present a first-principles study of the energy and elastic properties of solid helium at pressures below the range in which it is energetically stable. We find that the limit of mechanical stability in hcp He is bar, which lies significantly below the spinodal pressure found in the liquid phase (i.e., bar). Furthermore, we show that the pressure variation of the transverse and longitudinal sound velocities close to does not follow a power law of the form , in contrast to what is observed in the fluid.

  4. Characterizing healthy samples for studies of human cognitive aging

    PubMed Central

    Geldmacher, David S.; Levin, Bonnie E.; Wright, Clinton B.

    2012-01-01

    Characterizing the cognitive declines associated with aging, and differentiating them from the effects of disease in older adults, are important goals for human neuroscience researchers. This is also an issue of public health urgency in countries with rapidly aging populations. Progress toward understanding cognitive aging is complicated by numerous factors. Researchers interested in cognitive changes in healthy older adults need to consider these complexities when they design and interpret studies. This paper addresses important factors in study design, patient demographics, co-morbid and incipient medical conditions, and assessment instruments that will allow researchers to optimize the characterization of healthy participants and produce meaningful and generalizable research outcomes from studies of cognitive aging. Application of knowledge from well-designed studies should be useful in clinical settings to facilitate the earliest possible recognition of disease and guide appropriate interventions to best meet the needs of the affected individual and public health priorities. PMID:22988440

  5. The Werner syndrome protein limits the error-prone 8-oxo-dG lesion bypass activity of human DNA polymerase kappa

    PubMed Central

    Maddukuri, Leena; Ketkar, Amit; Eddy, Sarah; Zafar, Maroof K.; Eoff, Robert L.

    2014-01-01

    Human DNA polymerase kappa (hpol ?) is the only Y-family member to preferentially insert dAMP opposite 7,8-dihydro-8-oxo-2?-deoxyguanosine (8-oxo-dG) during translesion DNA synthesis. We have studied the mechanism of action by which hpol ? activity is modulated by the Werner syndrome protein (WRN), a RecQ helicase known to influence repair of 8-oxo-dG. Here we show that WRN stimulates the 8-oxo-dG bypass activity of hpol ? in vitro by enhancing the correct base insertion opposite the lesion, as well as extension from dC:8-oxo-dG base pairs. Steady-state kinetic analysis reveals that WRN improves hpol ?-catalyzed dCMP insertion opposite 8-oxo-dG ?10-fold and extension from dC:8-oxo-dG by 2.4-fold. Stimulation is primarily due to an increase in the rate constant for polymerization (kpol), as assessed by pre-steady-state kinetics, and it requires the RecQ C-terminal (RQC) domain. In support of the functional data, recombinant WRN and hpol ? were found to physically interact through the exo and RQC domains of WRN, and co-localization of WRN and hpol ? was observed in human cells treated with hydrogen peroxide. Thus, WRN limits the error-prone bypass of 8-oxo-dG by hpol ?, which could influence the sensitivity to oxidative damage that has previously been observed for Werner's syndrome cells. PMID:25294835

  6. Human cardiomyocyte progenitor cells differentiate into functional mature cardiomyocytes: an in vitro model for studying human cardiac physiology and pathophysiology

    Microsoft Academic Search

    Anke M Smits; Patrick van Vliet; Corina H Metz; Tom Korfage; Joost PG Sluijter; Pieter A Doevendans; Marie-José Goumans

    2009-01-01

    To date, there is no suitable in vitro model to study human adult cardiac cell biology. Although embryonic stem cells are able to differentiate into cardiomyocytes in vitro, the efficiency of this process is very low. Other methods to differentiate progenitor cells into beating cardiomyocytes rely on coculturing with rat neonatal cardiomyocytes, making it difficult to study human cardiomyocyte differentiation

  7. Further studies of 60 Hz exposure effects on human function

    SciTech Connect

    Graham, C.

    1990-07-20

    Public concern has been expressed about possible health risks arising from exposure to the electric and magnetic fields generated by power distribution systems. This project is addressing this concern through a laboratory research program designed to evaluate the effects of brief exposure to known field conditions on multiple measures of human function. In this continuation effort, a series of exploratory studies are being performed, which will be followed by a confirmatory experiment, to determine if the above physiological effects differ as a function of exposure to the electric and magnetic fields separately and combined, time of day, and rate of intermittent exposure. Project status to date is as follows. Funds were awarded in the last reporting period to continue this research activity at a reduced level until December 31, 1990. An initial series of exploratory studies, involving 24 healthy male volunteers exposed over multiple sessions, has been completed. These studies assessed whether effects on human physiology differ over the day as a function of intermittent exposure to the electric versus the magnetic fields. Exposure to the magnetic fields produced a pattern of cardiac changes similar to that observed in our previous research. This pattern was not found when subjects were exposed to the electric field. During this reporting period our goals were to: continue performance of the probe'' studies; and present project findings at the 1990 meeting of the Bioelectromagnetics Society (BEMS).

  8. Human Kallikrein 10 Expression in Surgically Removed Human Pituitary Corticotroph Adenomas: An Immunohistochemical Study.

    PubMed

    Di Meo, Ashley; Rotondo, Fabio; Kovacs, Kalman; Cusimano, Michael D; Syro, Luis V; Di Ieva, Antonio; Diamandis, Eleftheros P; Yousef, George M

    2015-07-01

    Human kallikrein 10 (hk10), a secreted serine protease, was reported to function as a tumor suppressor. hK10 immunoexpression has been demonstrated in lactrotrophs and corticotrophs of the nontumorous human adenohypophysis. In the present study, for the first time we report hK10 immunoexpression in various surgically removed corticotroph adenoma subtypes. Specimens were fixed in formalin and embedded in paraffin. Immunostaining was performed using the streptavidin-biotin-peroxidase complex method with an hK10-specific rabbit polyclonal antibody. Results showed that the endocrinologically active adrenocorticotropic hormone (ACTH)-producing pituitary tumors and the silent subtypes were immunopositve for hK10. Intensity of staining varied between the different subtypes. Intensity was lowest in the silent subtypes (silent corticotroph subtypes 1 and 2) compared with nontumorous human adenohypophysial corticotrophs, whereas the endocrinologically active subtypes (ACTH-secreting adenomas, corticotroph carcinomas, Crooke cell adenomas, Crooke cell carcinomas), showed the highest hK10 immunoexpression. Immunopositivity in the nuclei of the ACTH-secreting adenomas and carcinomas, as well as dual cytoplasmic and nuclear localization of hK10 in some of the secreting tumor types was an intriguing finding. Immunoexpression of hK10 in the ACTH-secreting tumors as well as in the Crooke cell tumors was significantly increased when compared with the nonfunctioning tumors and in the corticotrophs of nontumorous pituitaries. PMID:25517869

  9. The Human First Trimester Gestational Sac Limits Rather than Facilitates Oxygen Transfer to the Foetus—A Review

    Microsoft Academic Search

    E. Jauniaux; B. Gulbis; G. J. Burton

    2003-01-01

    Oxygen (O2) free radicals are a potential teratologic threat to the foetal tissues and are known to be involved in the pathophysiology of common human pregnancy disorders such as miscarriage and pre-eclampsia. During the first two months of human gestation, the placenta surrounds the whole gestational sac, the villi contain only a few capillaries located mainly within the centre of

  10. The genomics of preterm birth: from animal models to human studies

    PubMed Central

    2013-01-01

    Preterm birth (delivery at less than 37 weeks of gestation) is the leading cause of infant mortality worldwide. So far, the application of animal models to understand human birth timing has not substantially revealed mechanisms that could be used to prevent prematurity. However, with amassing data implicating an important role for genetics in the timing of the onset of human labor, the use of modern genomic approaches, such as genome-wide association studies, rare variant analyses using whole-exome or genome sequencing, and family-based designs, holds enormous potential. Although some progress has been made in the search for causative genes and variants associated with preterm birth, the major genetic determinants remain to be identified. Here, we review insights from and limitations of animal models for understanding the physiology of parturition, recent human genetic and genomic studies to identify genes involved in preterm birth, and emerging areas that are likely to be informative in future investigations. Further advances in understanding fundamental mechanisms, and the development of preventative measures, will depend upon the acquisition of greater numbers of carefully phenotyped pregnancies, large-scale informatics approaches combining genomic information with information on environmental exposures, and new conceptual models for studying the interaction between the maternal and fetal genomes to personalize therapies for mothers and infants. Information emerging from these advances will help us to identify new biomarkers for earlier detection of preterm labor, develop more effective therapeutic agents, and/or promote prophylactic measures even before conception. PMID:23673148

  11. Low power optical limiting studies of copper doped lithium tetraborate nanoparticles.

    PubMed

    Dhanuskodi, S; Mohandoss, R; Vinitha, G; Pathinettam Padiyan, D

    2015-04-01

    The copper doped lithium tetraborate (LTB:Cu) nanoparticles were synthesized by sol-gel method and characterized by XRD (tetragonal structure) and by FESEM (sphere-like nanoparticle). UV-Vis studies show that there is no strong absorption in the visible region. In the luminescence spectrum, the emission peak at 370 nm reveals the presence of Cu+ in LTB lattice. The relative powder second harmonic generation efficiency of pure and doped LTB is equal to the standard NLO material, KDP. The nonlinear optical parameters of LTB:Cu nanoparticles say, nonlinear refractive index, nonlinear absorption coefficient and third order nonlinear optical susceptibility were determined to be of the order of 10(-8)cm2/W, 10(-2) cm/W and 10(-5) esu, respectively. The optical power limiting behavior of the samples were studied by Z-scan technique with (532 nm, 50 mW) Nd:YAG laser and the limiting threshold values are found to be 22.7 mW for 0.01 M and 24.9 mW for 0.03 and 0.05 M LTB:Cu nanoparticles. PMID:25615676

  12. Observation and imitation of actions performed by humans, androids, and robots: an EMG study

    PubMed Central

    Hofree, Galit; Urgen, Burcu A.; Winkielman, Piotr; Saygin, Ayse P.

    2015-01-01

    Understanding others’ actions is essential for functioning in the physical and social world. In the past two decades research has shown that action perception involves the motor system, supporting theories that we understand others’ behavior via embodied motor simulation. Recently, empirical approach to action perception has been facilitated by using well-controlled artificial stimuli, such as robots. One broad question this approach can address is what aspects of similarity between the observer and the observed agent facilitate motor simulation. Since humans have evolved among other humans and animals, using artificial stimuli such as robots allows us to probe whether our social perceptual systems are specifically tuned to process other biological entities. In this study, we used humanoid robots with different degrees of human-likeness in appearance and motion along with electromyography (EMG) to measure muscle activity in participants’ arms while they either observed or imitated videos of three agents produce actions with their right arm. The agents were a Human (biological appearance and motion), a Robot (mechanical appearance and motion), and an Android (biological appearance and mechanical motion). Right arm muscle activity increased when participants imitated all agents. Increased muscle activation was found also in the stationary arm both during imitation and observation. Furthermore, muscle activity was sensitive to motion dynamics: activity was significantly stronger for imitation of the human than both mechanical agents. There was also a relationship between the dynamics of the muscle activity and motion dynamics in stimuli. Overall our data indicate that motor simulation is not limited to observation and imitation of agents with a biological appearance, but is also found for robots. However we also found sensitivity to human motion in the EMG responses. Combining data from multiple methods allows us to obtain a more complete picture of action understanding and the underlying neural computations.

  13. Human factor study on the crosstalk of multiview autostereoscopic displays

    NASA Astrophysics Data System (ADS)

    Yang, Jinn-Cherng; Huang, Kuo-Chung; Wu, Chou-Lin; Lee, Kuen; Hwang, Sheue-Ling

    2010-04-01

    Stereoscopic depth perception has been analyzed in many laboratory experiments since Wheatstone's (1838) discovery that disparity is a sufficient and compelling stimulus for the perception of depth with mirror-type stereo displays. In this paper, mirror-type stereo displays were used as the instrument to simulate the 3D image in the human factor experiment. It can be used to simulate the 9 view 3D display by image processing method with different multi-view crosstalk levels measured from luminance measurement device. The disparity of multi-view images to form stereopsis with depth perception is decided by the 9-view autostereoscopic 3D display that subject can properly fuse the image to get the proper visual depth. Computer graphic method applied for multi-view content rendering with shooting distance of 70 cm for each virtual camera. The distance between cameras is 5.6 cm with parallel capture to simulate the images accepted by human eyes. The experimental design was used for testing subjective evaluations based on the questionnaire, and ANOVA methods were used for analysis. Experimental variables of this human factor study for multi-view 3D display are five levels of crosstalk distribution from measured data, with or without shadow effects and perspective line shown within tested images. In addition, the result of acceptable system crosstalk level for multi-view stereoscopic display is between Level 4.7 and Level 5.9 in average for the four tested images.

  14. Energy Engineering Analysis Program, Limited Energy Study, Watervliet Arsenal, Watervliet, New York; Volume 1: narrative report

    SciTech Connect

    NONE

    1992-08-01

    The objectives of this contract, as explained in the Detailed Scope of Work (Appendix A in Volume II) of the contract are: (A) Review, use, and incorporate applicable data and results of the previously completed Energy Engineering Analysis Program study. (B) Perform a limited site audit and analysis of the industrial facility. (C) Re-evaluate specific projects or ECOs from the previous study to determine its economic feasibility based on revised criteria, current site conditions and technical applicability. (D) Evaluate specific ECOs to determine their energy savings potential and economic feasibility as indicated in the Appendix of the Scope of Work. (E) Prepare programming and implementation documentation for all justifiable ECOs. and (F) Prepare a comprehensive report which will document the work accomplished, the results, and the recommendations.

  15. Energy Engineering Analysis Program. Limited energy study, Watervliet Arsenal, Watervliet, New York. Executive summary. Final report

    SciTech Connect

    NONE

    1992-08-01

    The objectives of this contract, as explained in the Detailed Scope of Work (Appendix A in Volume II) of the contract are as follows: A. Review, use and incorporate applicable data and results of the previously completed Energy Engineering Analysis Program study. B. Perform a limited site audit and analysis of the industrial facility. C. Re-evaluate specific projects or ECOs from the previous study to determine its economic feasibility based on revised criteria, current site conditions and technical applicability. However, no previously identified process energy-related projects or ECOs were selected by Watervliet Arsenal. D. Evaluate specific ECOs to determine their energy savings potential and economic feasibility as indicated in the Appendix of the Scope of Work. E. Prepare programming and implementation documentation for all justifiable ECOs. F. Prepare a comprehensive report which will document the work accomplished, the results and the recommendations.

  16. Development of myenteric plexus in human foetuses: a quantitative study

    PubMed Central

    Shariff, Ahmadulla; Roy, Tarasankar; Das, Taposh; Rani, Neerja

    2015-01-01

    Maturation of neurons of the myenteric plexus (MP) of human fetal sigmoid colon was studied at various weeks of gestation (WG). There is abundant literature on the development of MP in various segments of the gut but there are fewer reports on the development of MP in human sigmoid colon which is a site of various disorders. Sigmoid colonic segments from 12 aborted foetuses aged 14-23WG were processed for NADPH histochemistry. Stereologic evaluation of the neuronal cell profiles, numerical density, number of neurons per ganglion and myenteric fraction was conducted using using imageJ software. According to gestational age, foetuses were assigned into two groups (group 1 [n=7], less than <17WG and group 2 [n=5], more than >17WG). The overall size of neuronal cell profiles in the MP was significantly increased (P<0.05). The numerical density of neurons decreased in group 2 in comparison to group 1, the number of neurons per ganglion and myenteric fraction were increased in group 2 but all these were not statistically significant. This study revealed that the maturational event increases after 17WG and extensive innervations is established at 23WG. During prenatal life there is an increase in the neuronal cell size from 14-23WG signifying maturational process. Such studies are essential for clinicians and surgeons to correlate the normal and pathologic development of the enteric nervous system.

  17. Further studies of 60 Hz exposure effects on human function

    SciTech Connect

    Graham, C.; Cohen, H.D.

    1990-10-09

    Public concern has been expressed about possible health risks arising from exposure to the electric and magnetic fields generated power distribution systems. This project is addressing this concern through a laboratory research program designed to evaluate the effects of brief exposure to known field conditions on multiple measures of human function. In previous research, we found that exposure had statistically significant effects on physiological measures of cardiac and brain activity, and on performance measures of reaction time and performance accuracy. Effects were seen more clearly under intermittent exposure conditions, and at certain levels of electric and magnetic field strength. In this continuation effort, we are performing a series of exploratory studies, to be followed by a confirmatory experiment, to determine if the above physiological effects differ as a function of exposure to the electric and magnetic fields separately and combined, time of day, and rate of intermittent exposure. Further studies will explore the mechanisms underlying these effects. The information developed in this project will be of value in risk assessment activities, and in basic research aimed at identifying specific factors involved in the interaction of power line fields with the human system. In this reporting period our goals were to: (a) continue performance of the probe studies; (b) participate in a site visit at MRI; (c) request 1991 research continuation funding; and (d) submit an abstract of project findings for presentation at the 1990 DOE Contractors Review Meeting.

  18. The dopaminergic basis of human behaviors: a review of molecular imaging studies

    PubMed Central

    Egerton, Alice; Mehta, Mitul A; Montgomery, Andrew J; Lappin, Julia M; Howes, Oliver D; Reeves, Suzanne J; Cunningham, Vincent J; Grasby, Paul M

    2013-01-01

    This systematic review describes human molecular imaging studies which have investigated alterations in extracellular DA levels during performance of behavioral tasks. Whilst heterogeneity in experimental methods limits meta-analysis, we describe the advantages and limitations of different methodological approaches. Interpretation of experimental results may be limited by regional cerebral blood flow (rCBF) changes, head movement and choice of control conditions. We revisit our original study of striatal DA release during video-game playing (Koepp et al., 1998) to illustrate the potentially confounding influences of head movement and alterations in rCBF. Changes in [11C]raclopride binding may be detected in extrastriatal as well as striatal brain regions – however we review evidence which suggests that extrastriatal changes may not be clearly interpreted in terms of DA release. Whilst several investigations have detected increases in striatal extracellular DA concentrations during task components such as motor learning and execution, reward-related processes, stress and cognitive performance, the presence of potentially biasing factors should be carefully considered (and, where possible, accounted for) when designing and interpreting future studies. PMID:19481108

  19. Roadmap: Technical and Applied Studies NonprofitHuman Services Bachelor of Technical and Applied Studies

    E-print Network

    Sheridan, Scott

    Roadmap: Technical and Applied Studies ­ Nonprofit­Human Services ­ Bachelor of Technical and Applied Studies [RE-BTAS-TAS-NPHS] Regional College Catalog Year: 2013-2014 Page 1 of 3 | Last Updated: 19 Summary on page 2 Kent Core Requirement 3 See Kent Core Summary on page 2 Applied Course 3 See note 1

  20. Roadmap: Technical and Applied Studies NonprofitHuman Services Bachelor of Technical and Applied Studies

    E-print Network

    Sheridan, Scott

    Roadmap: Technical and Applied Studies ­ Nonprofit­Human Services ­ Bachelor of Technical and Applied Studies [RE-BTAS-TAS-NPHS] Regional College Catalog Year: 2012-2013 Page 1 of 3 | Last Updated: 22 Summary on page 2 Kent Core Requirement 3 See Kent Core Summary on page 2 Applied Course 3 See note 1

  1. Yeast Modulation of Human Dendritic Cell Cytokine Secretion: An In Vitro Study

    PubMed Central

    Smith, Ida M.; Christensen, Jeffrey E.; Arneborg, Nils; Jespersen, Lene

    2014-01-01

    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The concept of individual microorganisms influencing the makeup of T cell subsets via interactions with intestinal dendritic cells (DCs) appears to constitute the foundation for immunoregulatory effects of probiotics, and several studies have reported probiotic strains resulting in reduction of intestinal inflammation through modulation of DC function. Consequent to a focus on Saccharomyces boulardii as the fundamental probiotic yeast, very little is known about hundreds of non-Saccharomyces yeasts in terms of their interaction with the human gastrointestinal immune system. The aim of the present study was to evaluate 170 yeast strains representing 75 diverse species for modulation of inflammatory cytokine secretion by human DCs in vitro, as compared to cytokine responses induced by a S. boulardii reference strain with probiotic properties documented in clinical trials. Furthermore, we investigated whether cytokine inducing interactions between yeasts and human DCs are dependent upon yeast viability or rather a product of membrane interactions regardless of yeast metabolic function. We demonstrate high diversity in yeast induced cytokine profiles and employ multivariate data analysis to reveal distinct clustering of yeasts inducing similar cytokine profiles in DCs, highlighting clear species distinction within specific yeast genera. The observed differences in induced DC cytokine profiles add to the currently very limited knowledge of the cross-talk between yeasts and human immune cells and provide a foundation for selecting yeast strains for further characterization and development toward potentially novel yeast probiotics. Additionally, we present data to support a hypothesis that the interaction between yeasts and human DCs does not solely depend on yeast viability, a concept which may suggest a need for further classifications beyond the current definition of a probiotic. PMID:24816850

  2. AN OVERVIEW OF THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) PHASE I STUDIES

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) Phase I studies were sponsored by EPA's Office of Research and Development (ORD) to address critical information needs for assessing human exposures to multiple chemicals from multiple pathways and media. These studies were...

  3. To boil or not to boil -- A study of bubble embryo dormancy limits

    SciTech Connect

    Martin-Dominguez, I.R. [Inst. Politecnico Nacional-CIIDIR Unidad Durango, Durango City (Mexico); McDonald, T.W. [Univ. of Windsor, Ontario (Canada)

    1997-12-31

    In the literature, particularly for refrigerants, experimental studies on the superheat required to initiate nucleate boiling tend to be widely scattered, not only among investigators but even for repeated tests by the same investigator. This study provides an explanation of why this occurs and how to avoid such scatter in future tests. With few exceptions, only re-entrant surface cavities are capable of containing dormant vapor bubble embryos. These dormant embryos are essential to initiate nucleate boiling from a cavity. The temperature (wall superheat) range over which an embryo is stable depends upon the cavity shape, neck size, and the fluid surface tension and thermal properties. Above the upper wall-superheat limit, nucleate boiling occurs. Below the lower limit, the embryo will quench (vanish) and cannot be reactivated by increasing the wall superheat. This study makes the following points, for a given cavity shape, fluid, and pressure (1) The larger the cavity neck radius, the smaller the wall-superheat range over which an embryo can exist. (2) Upon cooling any surface, the boiling cavity with the smallest neck radius will be the first to stop boiling but will require the greatest reduction in wall superheat to quench its embryo. (3) Each site that retains a (dormant) vapor embryo will resume boiling at the same wall-superheat at which it ceased boiling. (4) Small cavities can have a shape such that their vapor embryos will always exist, regardless of the wall temperature. Boiling can always be reinitiated from them. (5) Any wall subject to boiling has a memory. The greater the past wall-subcooling, the greater will be the wall-superheat required to initiate boiling. (6) The wall memory can be erased with sufficient wall-superheat and the presence of vapor.

  4. Limiting performance analysis of the protection of the human head from impact-induced injuries taking into account the duration of the shock pulse

    Microsoft Academic Search

    D. V. Balandin; A. S. Belozerov; N. N. Bolotnik

    2008-01-01

    The limiting possibilities of the protection of the human head from impacts by means of helmets are analyzed. The shell (base)\\u000a of the helmet is assumed to decelerate after an impact against an obstacle with constant acceleration during a given time\\u000a interval. The minimum of the peak magnitude of the displacement of the head (the object to be protected) relative

  5. Studies of [ital WW] and [ital WZ] production and limits on anomalous [ital WW[gamma

    SciTech Connect

    Grinstein, S.; Mostafa, M.; Piegaia, R. (Universidad de Buenos Aires, Buenos Aires (Argentina)); Alves, G.A.; Carvalho, W.; da Motta, H.; Santoro, A. (LAFEX, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil)); Lima, J.G.; Oguri, V. (Universidade do Estado do Rio de Janeiro, Rio de Janeiro (Brazil)); Mao, H.S. (Inst. of High Energy Physics, Beijing, Peoples Republic of (China)); Gomez, B.; Mooney, P.; Negret, J.P. (Universidad de los Andes, Bogota (Colombia)); Hoeneisen, B. (Universidad San Francisco de Quito, Quito (Ecuador)); Parua, N. (Institut des Sciences Nucleaires, IN2P3-CNRS, Universite de Grenoble 1, Grenoble (France)); Ducros, Y. (DAPNIA/Service de Physique des Particules, CEA, Saclay (France)); Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B. (Panjab Unv., Chandigarh (India)); Shivpuri, R.K. (Delhi Unv., Delhi (India)); Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Shankar, H.C. (Tata Inst.

    1999-10-01

    Evidence of anomalous WW and WZ production was sought in p[bar p] collisions at a center-of-mass energy of [radical] (s) =1.8 hthinsp;TeV. The final states WW(WZ)[r arrow][mu][nu] jet jet+X, WZ[r arrow][mu][nu]ee+X and WZ[r arrow]e[nu]ee+X were studied using a data sample corresponding to an integrated luminosity of approximately 90 hthinsp;pb[sup [minus]1]. No evidence of anomalous diboson production was found. Limits were set on anomalous WW[gamma] and WWZ couplings and were combined with our previous results. The combined 95[percent] confidence level anomalous coupling limits for [Lambda]=2 hthinsp;TeV are [minus]0.25[le][Delta][kappa][le]0.39 ([lambda]=0) and [minus]0.18[le][lambda][le]0.19 ([Delta][kappa]=0), assuming the WW[gamma] couplings are equal to the WWZ couplings. [copyright] [ital 1999] [ital The American Physical Society

  6. Resonance Raman Spectroscopic Evaluation of Skin Carotenoids as a Biomarker of Carotenoid Status for Human Studies

    PubMed Central

    Mayne, Susan T.; Cartmel, Brenda; Scarmo, Stephanie; Jahns, Lisa; Ermakov, Igor V.; Gellermann, Werner

    2013-01-01

    Resonance Raman Spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes. PMID:23823930

  7. Enhanced Transmural Fiber Rotation and Connexin 43 Heterogeneity Are Associated With an Increased Upper Limit of Vulnerability in a Transgenic Rabbit Model of Human Hypertrophic Cardiomyopathy

    PubMed Central

    Ripplinger, Crystal M.; Li, Wenwen; Hadley, Jennifer; Chen, Junjie; Rothenberg, Florence; Lombardi, Raffaella; Wickline, Samuel A.; Marian, Ali J.; Efimov, Igor R.

    2008-01-01

    Human hypertrophic cardiomyopathy, characterized by cardiac hypertrophy and myocyte disarray, is the most common cause of sudden cardiac death in the young. Hypertrophic cardiomyopathy is often caused by mutations in sarcomeric genes. We sought to determine arrhythmia propensity and underlying mechanisms contributing to arrhythmia in a transgenic (TG) rabbit model (?-myosin heavy chain–Q403) of human hypertrophic cardiomyopathy. Langendorff-perfused hearts from TG (n = 6) and wild-type (WT) rabbits (n = 6) were optically mapped. The upper and lower limits of vulnerability, action potential duration (APD) restitution, and conduction velocity were measured. The transmural fiber angle shift was determined using diffusion tensor MRI. The transmural distribution of connexin 43 was quantified with immunohistochemistry. The upper limit of vulnerability was significantly increased in TG versus WT hearts (13.3 ± 2.1 versus 7.4 ± 2.3 V/cm; P = 3.2e?5), whereas the lower limits of vulnerability were similar. APD restitution, conduction velocities, and anisotropy were also similar. Left ventricular transmural fiber rotation was significantly higher in TG versus WT hearts (95.6 ± 10.9° versus 79.2 ± 7.8°; P = 0.039). The connexin 43 density was significantly increased in the mid-myocardium of TG hearts compared with WT (5.46 ± 2.44% versus 2.68 ± 0.77%; P = 0.024), and similar densities were observed in the endo- and epicardium. Because a nearly 2-fold increase in upper limit of vulnerability was observed in the TG hearts without significant changes in APD restitution, conduction velocity, or the anisotropy ratio, we conclude that structural remodeling may underlie the elevated upper limit of vulnerability in human hypertrophic cardiomyopathy. PMID:17885214

  8. Humanimalia: A journal of human/animal interface studies

    NSDL National Science Digital Library

    The website for the new journal Humanimalia, published by DePauw University, recently released its first issue. The appeal and importance of the journal goes beyond appearance, as the journal states that the study of the human/animal interface has been a "neglected" area of research. In the "Humanimalifesto" link, a lengthy explanation is given, and it notes that one of the main goals of the journal is "to approach animal/human interfaces without relying on stigmatizing critique of philosophical, political, or cultural antagonists." The first issue consists of articles and reviews, including an article called "Hooters for Neuters: Sexist Transgressive Animal Advocacy Campaign?" and a review of the popular Michael Pollan book, "The Omnivore's Dilemma: A Natural History of Four Meals". Visitors interested in submitting an article to the peer-reviewed, interdisciplinary journal should check out the guidelines in the "Call-for-Papers" link on the left side of the page. The "Notes and Bulletins" link, also on the left side of the page, has a notice of an Animal Studies meeting at NYU, and the "Links" area includes information on upcoming conferences.

  9. CENSHARE - Center to Study Human Animal Relationships and Environments

    NSDL National Science Digital Library

    Established in 1981 at the University of Minnesota's School of Public Health, the Center to Study Human Animal Relationships and Environments (CENSHARE) is an umbrella organization that supports groups that aim to educate about the human animal relationship and the environment they share. This mission of this education is to improve the quality of life for both, encourage scientific study of such relationships, and also serve as a resource for the community on these relationships. Visitors should check out the thorough explanation of "Animal Assisted Therapy" (AAT), and learn how it differs from, say, Animal Assisted Activities (AAA). As animal therapy can be stressful on the animal if it is not properly trained for such demanding work, the AAT link gives helpful tips to visitors on how to get an animal ready to be a therapy animal. Visitors will also learn from the AAT link that such animals have been evaluated and registered by national groups that specialize in therapy animals, but are not given the federal protections that specially-trained service dogs are, such as access to public transportation and public buildings. Finally, visitors should check out the "Companion Animals in Care Environments" link. Here they can read a bittersweet story titled "Lessons to be Learned from the Saga of Mae" which addresses the considerations that should be made when deciding whether to allow a resident animal in a care facility.

  10. Bioequivalence study of sildenafil citrate tablets in healthy human volunteers.

    PubMed

    Mandal, U; Musmade, Prashant; Chakraborty, Mita; Rajan, D Senthil; Chakravarti, M; Pal, T K; Chattaraj, T K

    2004-11-01

    Newly developed sildenafil citrate (SC), a selective inhibitor of cyclic guanosine monophosphate (c-GMP) specific phosphodiesterase type 5 (PDE 5) in the corpus cavernosum is used for the oral treatment of erectile dysfunction. A convenient, sensitive and simple method for the determination of sildenafil in human plasma is presented. The analytical technique was based on reversed-phase high-performance liquid chromatography coupled with UV detector set at 295 nm. Rofecoxib was used as internal standard (I.S). Liquid-liquid extraction using diethyl ether was performed to recover sildenafil and rofecoxib. The retention time of I.S and sildenafil were 5.5 minutes and 7.2 minutes respectively. The method was validated over a linear range of 10 to 1000 ng/ml from plasma. Separate stability study showed that sildenafil is stable under conditions of analysis. The extraction efficiency from plasma varied from 79.69% to 81.13 %. The minimum quantifiable concentration was set at 10 ng/ml. (%o CV<12.5%). The method was used for Bioequivalence Study of Two Brands of Sildenafil citrate 50 mg tablets in healthy human volunteers. All pharmacokinetic parameter were calculated along with statistical evaluation. PMID:15881813

  11. Evolutionary and developmental foundations of human knowledge: a case study of mathematics

    Microsoft Academic Search

    Marc D. Hauser; Elizabeth Spelke

    What are the brain and cognitive systems that allow humans to play baseball, compute square roots, cook soufflés, or navigate the Tokyo subways? It may seem that studies of human infants and of non-human animals will tell us little about these abilities, because only educated, enculturated human adults engage in organized games, formal mathematics, gourmet cooking, or map-reading. In this

  12. Current studies on human papillomavirus in Saudi Arabia.

    PubMed

    Alhamlan, Fatimah Saeed; Al-Qahtani, Ahmed A; Al-Ahdal, Mohammed N

    2015-01-01

    Human papillomavirus (HPV) infection is a significant etiological factor and an important prognosticator in cervical cancer. Indeed, researchers worldwide have confirmed these roles for high-risk HVPs in over 70% of cervical cancer cases. According to the World Health Organization, approximately 561,200 new cancer cases (5.2% of all new cancers) are attributed to HPV infection. Over 120 types of HPV are classified further as either low-risk HPV (LR-HPV) or high-risk HPV (HR-HPV) based on their oncological potential of transforming cells. The LR-HPV types cause benign hyperproliferative lesions (i.e. genital warts) while the HR-HPV types are strongly associated with premalignant and malignant cervical lesions. Data on the prevalence of HPV, survival of infected patients, and mortality rate are scarce in Saudi Arabia. The unsubstantiated assumption of a low prevalence of HPV in Saudi Arabia has contributed to limiting HPV research in this conservative country. Therefore, the goal of this review is to shed light on the current HPV research being conducted and the prevalence of HPV in Saudi Arabia. PMID:26142665

  13. SUGGESTED THREE-YEAR GRADUATION PLAN Human Development and Family Studies Case Management

    E-print Network

    Sheridan, Scott

    SUGGESTED THREE-YEAR GRADUATION PLAN Human Development and Family Studies ­Case Management HDFS 44192 Internship in Human Development and Family Studies: Case Management I 3-6 Offered in fall below #12;SUGGESTED THREE-YEAR GRADUATION PLAN Human Development and Family Studies ­Case Management

  14. SUGGESTED THREE-YEAR GRADUATION PLAN Human Development and Family Studies Case Management

    E-print Network

    Sheridan, Scott

    SUGGESTED THREE-YEAR GRADUATION PLAN Human Development and Family Studies ­Case Management Internship in Human Development and Family Studies: Case Management I 3-6 Offered in fall only; fulfills THREE-YEAR GRADUATION PLAN Human Development and Family Studies ­Case Management for Individuals

  15. Toxicity study of cerium oxide nanoparticles in human neuroblastoma cells.

    PubMed

    Kumari, Monika; Singh, Shailendra Pratap; Chinde, Srinivas; Rahman, Mohammed Fazlur; Mahboob, Mohammed; Grover, Paramjit

    2014-01-01

    The present study consisted of cytotoxic, genotoxic, and oxidative stress responses of human neuroblastoma cell line (IMR32) following exposure to different doses of cerium oxide nanoparticles (CeO2 NPs; nanoceria) and its microparticles (MPs) for 24 hours. Cytotoxicity was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays whereas genotoxicity was assessed using the cytokinesis-block micronucleus and comet assays. A battery of assays including lipid peroxidation, reactive oxygen species (ROS), hydrogen peroxide, reduced glutathione, nitric oxide, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, and glutathione S-transferase were performed to test the hypothesis that ROS was responsible for the toxicity of nanoceria. The results showed that nanosized CeO2 was more toxic than cerium oxide MPs. Hence, further study on safety evaluation of CeO2 NPs on other models is recommended. PMID:24510415

  16. ?-Cell Generation: Can Rodent Studies Be Translated to Humans?

    PubMed Central

    Carlotti, Françoise; Zaldumbide, Arnaud; Ellenbroek, Johanne H.; Spijker, H. Siebe; Hoeben, Rob C.; de Koning, Eelco J.

    2011-01-01

    ?-cell replacement by allogeneic islet transplantation is a promising approach for patients with type 1 diabetes, but the shortage of organ donors requires new sources of ? cells. Islet regeneration in vivo and generation of ?-cells ex vivo followed by transplantation represent attractive therapeutic alternatives to restore the ?-cell mass. In this paper, we discuss different postnatal cell types that have been envisaged as potential sources for future ?-cell replacement therapy. The ultimate goal being translation to the clinic, a particular attention is given to the discrepancies between findings from studies performed in rodents (both ex vivo on primary cells and in vivo on animal models), when compared with clinical data and studies performed on human cells. PMID:22007286

  17. Remote controlled capsules in human drug absorption (HDA) studies.

    PubMed

    Wilding, Ian R; Prior, David V

    2003-01-01

    The biopharmaceutical complexity of today's new drug candidates provides significant challenges for pharmaceutical scientists in terms of both candidate selection and optimizing subsequent development strategy. In addition, life cycle management of marketed drugs has become an important income stream for pharmaceutical companies, but the selection of least risk/highest benefit strategies is far from simple. The proactive adoption of human drug absorption (HDA) studies using remote controlled capsules offers the pharmaceutical scientist significant guidance for planning a route through the maze of product development. This review examines the position of HDA studies in drug development, using a variety of case histories and an insightful update on remote controlled capsules to achieve site-specific delivery. PMID:14979866

  18. Multi-Robot Information Sharing for Complementing Limited Perception: A Case Study of Moving Ball Interception

    E-print Network

    Veloso, Manuela M.

    aims to investigate why current approaches fail to effectively use teammate sensor data, propose have hardware limitations resulting in limited sensor range, field of view, and resolution in addition's own limited sensors but requires knowing the relative transform between the two robots to effectively

  19. Numerical study of the semiclassical limit of the Davey-Stewartson II equations

    NASA Astrophysics Data System (ADS)

    Klein, C.; Roidot, K.

    2014-09-01

    We present the first detailed numerical study of the semiclassical limit of the Davey-Stewartson II equations both for the focusing and the defocusing variant. We concentrate on rapidly decreasing initial data with a single hump. The formal limit of these equations for vanishing semiclassical parameter ?, the semiclassical equations, is numerically integrated up to the formation of a shock. The use of parallelized algorithms allows one to determine the critical time tc and the critical solution for these 2 + 1-dimensional shocks. It is shown that the solutions generically break in isolated points similarly to the case of the 1 + 1-dimensional cubic nonlinear Schrödinger equation, i.e., cubic singularities in the defocusing case and square root singularities in the focusing case. For small values of ?, the full Davey-Stewartson II equations are integrated for the same initial data up to the critical time tc. The scaling in ? of the difference between these solutions is found to be the same as in the 1 + 1 dimensional case, proportional to ?2/7 for the defocusing case and proportional to ?2/5 in the focusing case. We document the Davey-Stewartson II solutions for small ? for times much larger than the critical time tc. It is shown that zones of rapid modulated oscillations are formed near the shocks of the solutions to the semiclassical equations. For smaller ?, the oscillatory zones become smaller and more sharply delimited to lens-shaped regions. Rapid oscillations are also found in the focusing case for initial data where the singularities of the solution to the semiclassical equations do not coincide. If these singularities do coincide, which happens when the initial data are symmetric with respect to an interchange of the spatial coordinates, no such zone is observed. Instead the initial hump develops into a blow-up of the L? norm of the solution. We study the dependence of the blow-up time on the semiclassical parameter ?.

  20. Selenium speciation in human serum and its implications for epidemiologic research: a cross-sectional study.

    PubMed

    Vinceti, Marco; Grill, Peter; Malagoli, Carlotta; Filippini, Tommaso; Storani, Simone; Malavolti, Marcella; Michalke, Bernhard

    2015-07-01

    Observational studies addressing the relation between selenium and human health, particularly cancer risk, yielded inconsistent results, while most recent randomized trials showed a fairly consistent pattern suggesting null or adverse effects of the metalloid. One of the most plausible explanations for such inconsistencies is inadequate exposure assessment in observational studies, commonly carried out by measuring total Se content without taking into account the specific exposure to the individual chemical forms of the metalloid, whose toxic and nutritional properties may vary greatly. Data on the distribution of these species in human blood and their correlation with overall selenium levels are very limited. The concentrations of organic and inorganic selenium species were analyzed in serum of fifty subjects sampled from the general population of the municipality of Modena, northern Italy, aged from 35 to 70 years. Samples were collected during a 30-month period, and determinations of selenium species were carried out using high pressure liquid chromatography coupled with inductively coupled plasma dynamic reaction cell mass spectrometry. The majority of selenium was found to be present as organic species, but the inorganic forms showed higher levels than expected. These species showed limited correlations with age, sex and body mass index, while the organic forms increased in subjects consuming selenium-containing dietary supplements and decreased in smokers. The length of the sample storage period strongly influenced the distribution of selenium compounds, with a clear tendency towards higher inorganic and lower organic selenium levels over time. In multivariate analysis adjusting for potential confounders, total serum selenium correlated with human serum albumin-bound selenium and, in males, with two organic species of the metalloid (selenocysteine and glutathione peroxidase-bound selenium), while little association existed with the other organic forms and the inorganic ones. These findings highlight the potential for exposure misclassification of observational epidemiologic investigations based on overall selenium content in blood and possibly other tissues, and the critical role of the storage conditions for speciation analysis. PMID:26004885

  1. Preservation of glial cytoarchitecture from ex vivo human tumor and non-tumor cerebral cortical explants: A human model to study neurological diseases

    Microsoft Academic Search

    Kaisorn L. Chaichana; Vivian Capilla-Gonzalez; Oscar Gonzalez-Perez; Gustavo Pradilla; James Han; Alessandro Olivi; Henry Brem; Jose Manuel Garcia-Verdugo; Alfredo Quiñones-Hinojosa

    2007-01-01

    For the human brain, in vitro models that accurately represent what occurs in vivo are lacking. Organotypic models may be the closest parallel to human brain tissue outside of a live patient. However, this model has been limited primarily to rodent-derived tissue. We present an organotypic model to maintain intraoperatively collected human tumor and non-tumor explants ex vivo for a

  2. Welcome to Medical Humanities Medical Humanities is an expanding area of study which aims to provide an

    E-print Network

    Stell, John

    Welcome to Medical Humanities Medical Humanities is an expanding area of study which aims or practitioner, and the practice of medicine. At Keele it offers medical students the opportunity to intercalate and graduate with a BSc in addition to their medical degree. Intercalation normally takes place after two full

  3. Human cornea construct HCC—an alternative for in vitro permeation studies? A comparison with human donor corneas

    Microsoft Academic Search

    Stephan Reichl; Stefanie Döhring; Jürgen Bednarz; Christel C. Müller-Goymann

    2005-01-01

    Transcorneal in vitro permeation studies of ophthalmic drugs are normally performed with either excised animal corneas or latterly corneal cell culture models. A good correlation between these models and excised animal corneas regarding permeation behaviour of drugs has already been shown. However, comparisons between corneal in vitro models containing human cells and excised human corneas do not exist yet. Therefore

  4. Application of field geophysics in geomorphology: Advances and limitations exemplified by case studies

    NASA Astrophysics Data System (ADS)

    Schrott, Lothar; Sass, Oliver

    2008-01-01

    During the last decade, the use of geophysical techniques has become popular in many geomorphological studies. However, the correct handling of geophysical instruments and the subsequent processing of the data they yield are difficult tasks. Furthermore, the description and interpretation of geomorphological settings to which they apply can significantly influence the data gathering and subsequent modelling procedure ( e.g. achieving a maximum depth of 30 m requires a certain profile length and geophone spacing or a particular frequency of antenna). For more than three decades geophysical techniques have been successfully applied, for example, in permafrost studies. However, in many cases complex or more heterogeneous subsurface structures could not be adequately interpreted due to limited computer facilities and time consuming calculations. As a result of recent technical improvements, geophysical techniques have been applied to a wider spectrum of geomorphological and geological settings. This paper aims to present some examples of geomorphological studies that demonstrate the powerful integration of geophysical techniques and highlight some of the limitations of these techniques. A focus has been given to the three most frequently used techniques in geomorphology to date, namely ground-penetrating radar, seismic refraction and DC resistivity. Promising applications are reported for a broad range of landforms and environments, such as talus slopes, block fields, landslides, complex valley fill deposits, karst and loess covered landforms. A qualitative assessment highlights suitable landforms and environments. The techniques can help to answer yet unsolved questions in geomorphological research regarding for example sediment thickness and internal structures. However, based on case studies it can be shown that the use of a single geophysical technique or a single interpretation tool is not recommended for many geomorphological surface and subsurface conditions as this may lead to significant errors in interpretation. Because of changing physical properties of the subsurface material ( e.g. sediment, water content) in many cases only a combination of two or sometimes even three geophysical methods gives sufficient insight to avoid serious misinterpretation. A "good practice guide" has been framed that provides recommendations to enable the successful application of three important geophysical methods in geomorphology and to help users avoid making serious mistakes.

  5. Human neuroimaging studies on the hippocampal CA3 region – integrating evidence for pattern separation and completion

    PubMed Central

    Deuker, Lorena; Doeller, Christian F.; Fell, Juergen; Axmacher, Nikolai

    2014-01-01

    Human functional magnetic resonance imaging (fMRI) studies have long investigated the hippocampus without differentiating between its subfields, even though theoretical models and rodent studies suggest that subfields support different and potentially even opposite functions. The CA3 region of the hippocampus has been ascribed a pivotal role both in initially forming associations during encoding and in reconstructing a memory representation based on partial cues during retrieval. These functions have been related to pattern separation and pattern completion, respectively. In recent years, studies using high-resolution fMRI in humans have begun to separate different hippocampal subregions and identify the role of the CA3 subregion relative to the other subregions. However, some of these findings have been inconsistent with theoretical models and findings from electrophysiology. In this review, we describe selected recent studies and highlight how their results might help to define different processes and functions that are presumably carried out by the CA3 region, in particular regarding the seemingly opposing functions of pattern separation and pattern completion. We also describe how these subfield-specific processes are related to behavioral, functional and structural alterations in patients with mild cognitive impairment and Alzheimer’s disease. We conclude with discussing limitations of functional imaging and briefly outline possible future developments of the field. PMID:24624058

  6. A study on DC hybrid three-phase fault current limiting interrupter for a power distribution system

    NASA Astrophysics Data System (ADS)

    Shao, Hongtian; Satoh, Tomoyuki; Yamaguchi, Mitsugi; Fukui, Satoshi; Ogawa, Jun; Satoh, Takao; Ishikawa, Hiroyuki

    2005-10-01

    For the purpose of protecting electric power system, many researches and developments of fault current limiters are being performed. The authors studied a dc hybrid three-phase fault current limiting interrupter (FCLI) composed of a superconducting reactor and an S/N transition element, connected in series each other. The dc hybrid type fault current limiting interrupter can limit a fault current by means of the inductance of high temperature superconducting (HTS) coil together with the normal transition of HTS bulk material (HTSB). In the case of an accident, the normal transition of the bulk material can be accelerated by the magnetic field of the HTS coil. In this paper, the dc hybrid type fault current limiting interrupter for 5.5 km long 6.6 kV-600 A power distribution system is analyzed, and performances of fault current limitation and interruption are confirmed. Moreover, a reclosing operation is discussed for this power distribution system.

  7. Radiation studies inside a human phantom using the MATROSHKA facility

    NASA Astrophysics Data System (ADS)

    Reitz, G.

    MATROSHKA is an ESA-Multi-User facility for studies of the depth dose distribution of the different components of the orbital radiation field at different sides of the organs, occurring in human being exposed during an EVA (Extra Vehicular Activity) to cosmic radiation. MATROSHKA provides a pressurized housing for a human phantom equipped with passive and active experiment packages and for the electronics for experiment and housekeeping data acquisition, storage and transfer to the onboard data management system. Several institutes from Europe, Japan and US contribute to the radiation measurement program. The facility was launched on Jan 30, 2004 with PROGRESS, and installed during an EVA on February 26 at an external platform of the Russian Service Module (RSM). After several in-orbit tests the facility is planned to be activated for nominal operations mid April 2004. Data will than be transmitted to ground regularly during the mission. After the exposure time of one year the facility will be brought back to inside the RSM, where the passive experiments will be reinstalled and transported back to ground by Soyuz. The facility remains for further use inside the RSM. A detailed description of the facility and the radiation detectors including their final layout inside and around the phantom will be presented. The inclusion of first data of the active experiments in this report depends on availability.

  8. Evaluation of dengue virus strains for human challenge studies.

    PubMed

    Mammen, M P; Lyons, A; Innis, B L; Sun, W; McKinney, D; Chung, R C Y; Eckels, K H; Putnak, R; Kanesa-thasan, N; Scherer, J M; Statler, J; Asher, L V; Thomas, S J; Vaughn, D W

    2014-03-14

    Discordance between the measured levels of dengue virus neutralizing antibody and clinical outcomes in the first-ever efficacy study of a dengue tetravalent vaccine (Lancet, Nov 2012) suggests a need to re-evaluate the process of pre-screening dengue vaccine candidates to better predict clinical benefit prior to large-scale vaccine trials. In the absence of a reliable animal model and established correlates of protection for dengue, a human dengue virus challenge model may provide an approach to down-select vaccine candidates based on their ability to reduce risk of illness following dengue virus challenge. We report here the challenge of flavivirus-naïve adults with cell culture-passaged dengue viruses (DENV) in a controlled setting that resulted in uncomplicated dengue fever (DF). This sets the stage for proof-of-concept efficacy studies that allow the evaluation of dengue vaccine candidates in healthy adult volunteers using qualified DENV challenge strains well before they reach field efficacy trials involving children. Fifteen flavivirus-naïve adult volunteers received 1 of 7 DENV challenge strains (n=12) or placebo (n=3). Of the twelve volunteers who received challenge strains, five (two DENV-1 45AZ5 and three DENV-3 CH53489 cl24/28 recipients) developed DF, prospectively defined as ?2 typical symptoms, ?48h of sustained fever (>100.4°F) and concurrent viremia. Based on our study and historical data, we conclude that the DENV-1 and DENV-3 strains can be advanced as human challenge strains. Both of the DENV-2 strains and one DENV-4 strain failed to meet the protocol case definition of DF. The other two DENV-4 strains require additional testing as the illness approximated but did not satisfy the case definition of DF. Three volunteers exhibited effusions (1 pleural/ascites, 2 pericardial) and 1 volunteer exhibited features of dengue (rash, lymphadenopathy, neutropenia and thrombocytopenia), though in the absence of fever and symptoms. The occurrence of effusions in milder DENV infections counters the long-held belief that plasma leakage syndromes are restricted to dengue hemorrhagic fever/dengue shock syndromes (DHF/DSS). Hence, the human dengue challenge model may be useful not only for predicting the efficacy of vaccine and therapeutic candidates in small adult cohorts, but also for contributing to our further understanding of the mechanisms behind protection and virulence. PMID:24468542

  9. A study in human attention to guide computational action recognition

    E-print Network

    Sinai, Sam

    2014-01-01

    Computer vision researchers have a lot to learn from the human visual system. We, as humans, are usually unaware of how enormously difficult it is to watch a scene and summarize its most important events in words. We only ...

  10. [Problems and limitations of conventional and innovative methods for the diagnosis of Toxoplasmosis in humans and animals].

    PubMed

    Piergili Fioretti, D

    2004-06-01

    Diagnosis of toxoplasmosis is useful for human and animal health. Several techniques are employed for the diagnosis in feline and canine population. Coprological tests for the detection of oocysts in cat faeces are of little significance owing to short patency (15 days). Histological examinations of biological samples show a lack of reliability when the animals are infected with few parasites; the mouse inoculation is the most reliable method even if the detection of cysts in mice brain require 40 days. However tachyzoites of virulent strains can be isolated from peritoneal exudate 3-4 days after inoculation. Samples inoculation in cell cultures (VERO, human fibroblasts) requires specialized laboratories and fails if non viable parasites are present due to tissutal autolysis. Serological tests are the most used diagnostic methods; Dye test and IFAT that require intact tachyzoites are more sensitive and specific compared to IHA, LA, ELISA because, during the infection, the first significant increase of IgM and IgG antibodies was observed against cuticolar antigens. A PCR to identify T. gondii DNA in canine and feline biological samples was developed. The B1 PCR performed on blood samples was less sensitive than when it was performed on other biological fluids requiring 100 tachyzoites, instead of 10. Aqueous humor PCR results could be negative if the infection is low grade or is restricted to the posterior segment or the animal was previously treated with anti-Toxoplasma drugs. SNC disease may be also difficult to diagnose because an high serum IgG titer may be associated with locally production or leakage from serum through a compromised blood-CSF barrier. AB1 PCR was successfully applied for the diagnosis of Toxoplasma abortion in ewes requiring only 10 parasites in placental cotyledon samples; the test compared with mouse inoculation showed similar sensitivity. Discrepancies may have been due to a low and focal distribution of parasites in the tissues or to the presence of non viable parasites if the tissues are autolysed. In regard to diagnostic methods adaptable to slaughter testing, several serological tests have been studied (IFAT, ELISA, IHA) for detection of IgG in sheep, pigs, cattle using also recombinant antigens (gene fragments H4 and H11) to lack the cross reactivity. The problem is the antibodies fall to near background levels as the infection became chronic (6-10 months p.-i.). A highly sensitive and specific method (Toxo Taq Man) has been developed to detect and quantitate T. gondii burden in animal tissue samples (0.1 pg of T. gondii genomic DNA, which is equivalent to 1 bradyzoite) using T. gondii ITS1-derived primers and a fluorogenic probe via Real-Time PCR. This assay is compatible with automation technology for potential slaughterhouse use. The diagnosis of acute infection in human pregnancy is difficult since IgM antibodies can be detected for a very long time after the acute phase; an IgA increase is of more diagnostic value because can be detected only for 6-7 months while the short kinetics of IgE can be useful only to date the infection precisely. In addition an IgG seroconversion is essential for the diagnosis. Among the most reliable tests, IgG avidity test is useful when a single serum sample, in the first months of gestation, is available, but low avidity results may persist for as long as 1 year. For this purpose a panel of serologic tests must be performed (ELISA, EIA, ISAGA, IgG avidity, IFAT, Dye test) for IgM, IgA, IgG and IgE. The serological diagnosis of prenatal infection is difficult since maternal IgG are passively transferred in utero to the foetus and caution must be exercised in interpretation of IgM or IgA results. A technique of Western blots of paired maternal and baby sera for evidencing different bands in the blots of two sera was developed for this purpose (specificity 97-100%, sensitivity 96-98%). The most reliable methods for prenatal diagnosis are PCR, mouse inoculation and cultural techniques performed on amniotic fluid, foetal blood and peripheral maternal blood in p

  11. Comparison of methods for imputing limited-range variables: a simulation study

    PubMed Central

    2014-01-01

    Background Multiple imputation (MI) was developed as a method to enable valid inferences to be obtained in the presence of missing data rather than to re-create the missing values. Within the applied setting, it remains unclear how important it is that imputed values should be plausible for individual observations. One variable type for which MI may lead to implausible values is a limited-range variable, where imputed values may fall outside the observable range. The aim of this work was to compare methods for imputing limited-range variables, with a focus on those that restrict the range of the imputed values. Methods Using data from a study of adolescent health, we consider three variables based on responses to the General Health Questionnaire (GHQ), a tool for detecting minor psychiatric illness. These variables, based on different scoring methods for the GHQ, resulted in three continuous distributions with mild, moderate and severe positive skewness. In an otherwise complete dataset, we set 33% of the GHQ observations to missing completely at random or missing at random; repeating this process to create 1000 datasets with incomplete data for each scenario. For each dataset, we imputed values on the raw scale and following a zero-skewness log transformation using: univariate regression with no rounding; post-imputation rounding; truncated normal regression; and predictive mean matching. We estimated the marginal mean of the GHQ and the association between the GHQ and a fully observed binary outcome, comparing the results with complete data statistics. Results Imputation with no rounding performed well when applied to data on the raw scale. Post-imputation rounding and imputation using truncated normal regression produced higher marginal means than the complete data estimate when data had a moderate or severe skew, and this was associated with under-coverage of the complete data estimate. Predictive mean matching also produced under-coverage of the complete data estimate. For the estimate of association, all methods produced similar estimates to the complete data. Conclusions For data with a limited range, multiple imputation using techniques that restrict the range of imputed values can result in biased estimates for the marginal mean when data are highly skewed. PMID:24766825

  12. ?H2AX assay as DNA damage biomarker for human population studies: defining experimental conditions.

    PubMed

    Sánchez-Flores, María; Pásaro, Eduardo; Bonassi, Stefano; Laffon, Blanca; Valdiglesias, Vanessa

    2015-04-01

    H2AX histone phosphorylation represents an early event in the cellular response against DNA double-strand breaks (DSBs), and plays a central role in sensing and repairing DNA damage. Therefore, the analysis of H2AX phosphorylated (?H2AX) may be possibly used as biomarker of genotoxicity and genomic instability with a number of applications in human epidemiology. However, the lack of an experimental standard leads to a wide heterogeneity in the results obtained and their interpretation, affecting the reliability of the assay. To address the most critical issues limiting the use of the ?H2AX assay in human population studies, a flow cytometry analysis was performed to establish differences in ?H2AX levels between fresh or cryopreserved peripheral blood lymphocytes, and to assess the influence of phytohemagglutinin (PHA) stimulation. To this purpose, cells were treated with 4 known genotoxic chemicals with different mechanisms of DSB induction, ie, bleomycin, methyl methanesulfonate, camptothecin, and actinomycin. According to our results, both unstimulated and stimulated fresh lymphocytes can be efficiently employed to evaluate ?H2AX levels, but the sensitivity of the assay is depending upon the kind of damage observed. On the other hand, cryopreserved lymphocytes require PHA stimulation since unstimulated cells showed too high basal damage. Consequently, the protocol conditions will depend on the expected mechanism of production of DSB and the characteristics of the study design (sample collection and storage conditions, type of epidemiological study). Further studies are required to standardize the protocol of ?H2AX assay to be employed as biomarker of genotoxicity or genomic instability in human population studies. PMID:25616596

  13. Applying systems biology methods to the study of human physiology in extreme environments

    PubMed Central

    2013-01-01

    Systems biology is defined in this review as ‘an iterative process of computational model building and experimental model revision with the aim of understanding or simulating complex biological systems’. We propose that, in practice, systems biology rests on three pillars: computation, the omics disciplines and repeated experimental perturbation of the system of interest. The number of ethical and physiologically relevant perturbations that can be used in experiments on healthy humans is extremely limited and principally comprises exercise, nutrition, infusions (e.g. Intralipid), some drugs and altered environment. Thus, we argue that systems biology and environmental physiology are natural symbionts for those interested in a system-level understanding of human biology. However, despite excellent progress in high-altitude genetics and several proteomics studies, systems biology research into human adaptation to extreme environments is in its infancy. A brief description and overview of systems biology in its current guise is given, followed by a mini review of computational methods used for modelling biological systems. Special attention is given to high-altitude research, metabolic network reconstruction and constraint-based modelling. PMID:23849719

  14. Emergency Sonography Aids Diagnostic Accuracy of Torso Injuries: A Study in a Resource Limited Setting

    PubMed Central

    Tunuka, Charles Edward; Wangoda, Robert; Bugeza, Sam; Galukande, Moses

    2014-01-01

    Introduction. Clinical evaluation of patients with torso trauma is often a diagnostic challenge. Extended focused assessment with sonography for trauma (EFAST) is an emergency ultrasound scan that adds to the evaluation of intrathoracic abdominal and pericardial cavities done in FAST (focused assessment with sonography for trauma). Objective. This study compares EFAST (the index test) with the routine standard of care (SoC) investigations (the standard reference test) for torso trauma injuries. Methods. A cross-sectional descriptive study was conducted over a 3-month period. Eligible patients underwent EFAST scanning and the SoC assessment. The diagnostic accuracy of EFAST was calculated using sensitivity and specificity scores. Results. We recruited 197 patients; the M?:?F ratio was 5?:?1, with mean age of 27 years (SD 11). The sensitivity of EFAST was 100%, the specificity was 97%, the PPV was 87%, and the NPV was 100%. It took 5 minutes on average to complete an EFAST scan. 168 (85%) patients were EFAST-scanned. Most patients (82) (48%) were discharged on the same day of hospitalization, while 7 (4%) were still at the hospital after two weeks. The mortality rate was 18 (9%). Conclusion. EFAST is a reliable method of diagnosing torso injuries in a resource limited context. PMID:25114805

  15. TGFß1 limits the expansion of the osteoprogenitor fraction in cultures of human bone marrow stromal cells

    Microsoft Academic Search

    Susan Walsh; Carolyn Jefferiss; Karina Stewart; Jon N. Beresford

    2003-01-01

    Currently, there is considerable interest in the possibility of using cultured human bone marrow stromal cells (BMSCs) for skeletal tissue engineering. However, the factors that regulate their ex vivo expansion and promote their osteogenic maturation remain poorly defined. Using BMSCs obtained from a large cohort of adult donors, the effects of transforming growth factor (TGF)Ї on these processes have been

  16. GC?×?GC-TOFMS and supervised multivariate approaches to study human cadaveric decomposition olfactive signatures.

    PubMed

    Stefanuto, Pierre-Hugues; Perrault, Katelynn A; Stadler, Sonja; Pesesse, Romain; LeBlanc, Helene N; Forbes, Shari L; Focant, Jean-François

    2015-06-01

    In forensic thanato-chemistry, the understanding of the process of soft tissue decomposition is still limited. A better understanding of the decomposition process and the characterization of the associated volatile organic compounds (VOC) can help to improve the training of victim recovery (VR) canines, which are used to search for trapped victims in natural disasters or to locate corpses during criminal investigations. The complexity of matrices and the dynamic nature of this process require the use of comprehensive analytical methods for investigation. Moreover, the variability of the environment and between individuals creates additional difficulties in terms of normalization. The resolution of the complex mixture of VOCs emitted by a decaying corpse can be improved using comprehensive two-dimensional gas chromatography (GC?×?GC), compared to classical single-dimensional gas chromatography (1DGC). This study combines the analytical advantages of GC?×?GC coupled to time-of-flight mass spectrometry (TOFMS) with the data handling robustness of supervised multivariate statistics to investigate the VOC profile of human remains during early stages of decomposition. Various supervised multivariate approaches are compared to interpret the large data set. Moreover, early decomposition stages of pig carcasses (typically used as human surrogates in field studies) are also monitored to obtain a direct comparison of the two VOC profiles and estimate the robustness of this human decomposition analog model. In this research, we demonstrate that pig and human decomposition processes can be described by the same trends for the major compounds produced during the early stages of soft tissue decomposition. PMID:25910882

  17. Vascularization of developing human olfactory neuroepithelium - a morphometric study.

    PubMed

    Sangari, S K; Sengupta, P; Pradhan, S; Khatri, K

    2000-01-01

    The present study reveals intraepithelial capillaries in the olfactory neuroepithelium of human fetuses aged between 12 and 24 weeks of gestation, which disappear at birth. The area occupied by the intraepithelial capillaries increases significantly with fetal age (0.047 +/- 0.014 microm(2)/microm(2) at 12 weeks and 0.101 +/- 0. 025 microm(2)/microm(2) at 24 weeks) and with the thickness of the epithelium (45.00 +/- 6.74 microm at 8 weeks and 64.10 +/- 8.51 microm at 24 weeks). The vascularization of the developing neuroepithelium may suggest increased metabolic demand during development and maturation of the olfactory neuroepithelium, and postnatal retreat of capillaries to the underlying lamina propria may suggest diffusion of nutrients and gases from blood vessels into the lamina propria and direct gaseous exchange from the atmosphere. PMID:10867436

  18. Permission to Take Part in a Human Research Study Short Form Page 1 of 5

    E-print Network

    Ullrich, Paul

    or device · Withholding medical treatment from a human subject for any purpose other than maintenancePermission to Take Part in a Human Research Study Short Form Page 1 of 5 Document Revision Date in a Human Research Study Page 2 of 5 Document Revision Date: July 1, 2014 · That the Food and Drug

  19. Department of Geography and Human Environmental Studies Promotion Criteria Draft 2/6/09

    E-print Network

    Department of Geography and Human Environmental Studies Promotion Criteria Draft 2/6/09 Department of Geography and Human Environmental Studies Guidelines for Retention, Tenure and Promotion [as ratified 7 Feb] This document provides guidelines for retention, tenure and promotion in the Department of Geography and Human

  20. A MULTI-AGENT BASED SIMULATION FRAMEWORK FOR THE STUDY OF HUMAN AND

    E-print Network

    Stanford University

    A MULTI-AGENT BASED SIMULATION FRAMEWORK FOR THE STUDY OF HUMAN AND SOCIAL BEHAVIOR IN EGRESS, these tools rely heavily on the assumptions about human individual and social behaviors. Many for studying human and social behavior during building emergency evacuations. A prototype system has been

  1. SAFEgress: A Flexible Platform to Study the Effect of Human and Social Behaviors on Egress Performance

    E-print Network

    Stanford University

    SAFEgress: A Flexible Platform to Study the Effect of Human and Social Behaviors on Egress to incorporate human and social behaviors during evacautions. Simulation results on two scenarios are presented safety. Despite observations and studies about human behaviors during emergencies, most simulation tools

  2. Markers to measure immunomodulation in human nutrition intervention studies.

    PubMed

    Albers, Ruud; Antoine, Jean-Michel; Bourdet-Sicard, Raphaëlle; Calder, Philip C; Gleeson, Michael; Lesourd, Bruno; Samartín, Sonia; Sanderson, Ian R; Van Loo, Jan; Vas Dias, F Willem; Watzl, Bernhard

    2005-09-01

    Normal functioning of the immune system is crucial to the health of man, and diet is one of the major exogenous factors modulating individual immunocompetence. Recently, nutrition research has focused on the role of foods or specific food components in enhancing immune system responsiveness to challenges and thereby improving health and reducing disease risks. Assessing diet-induced changes of immune function, however, requires a thorough methodological approach targeting a large spectrum of immune system parameters. Currently, no single marker is available to predict the outcome of a dietary intervention on the resistance to infection or to other immune system-related diseases. The present review summarises the immune function assays commonly used as markers in human intervention studies and evaluates their biological relevance (e.g. known correlation with clinically relevant endpoints), sensitivity (e.g. within- and between-subject variation), and practical feasibility. Based on these criteria markers were classified into three categories with high, medium or low suitability. Vaccine-specific serum antibody production, delayed-type hypersensitivity response, vaccine-specific or total secretory IgA in saliva and the response to attenuated pathogens, were classified as markers with high suitability. Markers with medium suitability include natural killer cell cytotoxicity, oxidative burst of phagocytes, lymphocyte proliferation and the cytokine pattern produced by activated immune cells. Since no single marker allows conclusions to be drawn about the modulation of the whole immune system, except for the clinical outcome of infection itself, combining markers with high and medium suitability is currently the best approach to measure immunomodulation in human nutrition intervention studies. It would be valuable to include several immune markers in addition to clinical outcome in future clinical trials in this area, as there is too little evidence that correlates markers with global health improvement. PMID:16176618

  3. A prospective study of floor surface, shoes, floor cleaning and slipping in US limited-service restaurant workers

    Microsoft Academic Search

    Santosh K Verma; Wen Ruey Chang; Theodore K Courtney; David A Lombardi; Yueng-Hsiang Huang; Melanye J Brennan; Murray A Mittleman; James H Ware; Melissa J Perry

    2010-01-01

    ObjectivesSlips and falls are a leading cause of injury at work. Few studies, however, have systematically examined risk factors of slipping outside the laboratory environment. This study examined the association between floor surface characteristics, slip-resistant shoes, floor cleaning frequency and the risk of slipping in limited-service restaurant workers.Methods475 workers from 36 limited-service restaurants from three major chains in six states

  4. Polarization and charge limit studies of strained GaAs photocathodes

    SciTech Connect

    Saez, P.J.

    1997-03-01

    This thesis presents studies on the polarization and charge limit behavior of electron beams produced by strained GaAs photocathodes. These photocathodes are the source of high-intensity, high-polarization electron beams used for a variety of high-energy physics experiments at the Stanford Linear Accelerator Center. Recent developments on P-type, biaxially-strained GaAs photocathodes have produced longitudinal polarization in excess of 80% while yielding beam intensities of {approximately} 2.5 A/cm{sup 2} at an operating voltage of 120 kV. The SLAC Gun Test Laboratory, which has a replica of the SLAC injector, was upgraded with a Mott polarimeter to study the polarization properties of photocathodes operating in a high-voltage DC gun. Both the maximum beam polarization and the maximum charge obtainable from these photocathodes have shown a strong dependence on the wavelength of illumination, on the doping concentration, and on the negative electron affinity levels. The experiments performed for this thesis included studying the effects of temperature, cesiation, quantum efficiency, and laser intensity on the polarization of high-intensity beams. It was found that, although low temperatures have been shown to reduce the spin relaxation rate in bulk semiconductors, they don`t have a large impact on the polarization of thin photocathodes. It seems that the short active region in thin photocathodes does not allow spin relaxation mechanisms enough time to cause depolarization. Previous observations that lower QE areas on the photocathode yield higher polarization beams were confirmed. In addition, high-intensity, small-area laser pulses were shown to produce lower polarization beams. Based on these results, together with some findings in the existing literature, a new proposal for a high-intensity, high-polarization photocathode is given. It is hoped that the results of this thesis will promote further investigation on the properties of GaAs photocathodes.

  5. 73 FR 22800 - Human Subject Protection; Foreign Clinical Studies Not Conducted Under an Investigational New...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2008-04-28

    ...2004N-0018] Human Subject Protection; Foreign...Description of Informed Consent Process 7...freely given informed consent of study...and obtain informed consent, while helping...comparable human subject...

  6. TRANSLATIONAL STEM CELL STUDIES Consensus Guidance for Banking and Supply of Human

    E-print Network

    Zandstra, Peter W.

    TRANSLATIONAL STEM CELL STUDIES Consensus Guidance for Banking and Supply of Human Embryonic Stem Cell Lines for Research Purposes The International Stem Cell Banking Initiative # Humana Press 2009 Keywords Human embryonic stem cells . Cell banking . Standardisation . Microbiological testing

  7. 76 FR 1174 - Drugs for Human Use; Drug Efficacy Study Implementation; Oral Prescription Drugs Offered for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket Nos. FDA-1981-N-0361...5213, 6290, 6303, 6514, 8658, 11935, and 12152] Drugs for Human Use; Drug Efficacy Study Implementation; Oral Prescription...

  8. 77 FR 43337 - Drugs for Human Use; Drug Efficacy Study Implementation; Certain Prescription Drugs Offered for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket Nos. FDA-1975-N-0336...Hydrocortisone Acetate and Pramoxine Hydrochloride] Drugs for Human Use; Drug Efficacy Study Implementation; Certain...

  9. 77 FR 12310 - Drugs for Human Use; Drug Efficacy Study Implementation; Prescription Drugs That Contained...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-1978-N-0441] (formerly 78N-0324); DESI 10392] Drugs for Human Use; Drug Efficacy Study Implementation; Prescription...

  10. Integrative Review of the Literature on Adults with Limited Education and Skills and the Implications for Human Resource Development

    ERIC Educational Resources Information Center

    Hamilton, David W.; Torraco, Richard J.

    2013-01-01

    Adults with limited education and skills--those who lack the education and skills needed for full participation in U.S. culture and economy--are increasing in numbers. However, the knowledge base addressing this population and their educational needs is fragmented across the literature of several disciplines. A comprehensive review and critique of…

  11. Theranostic Studies of Human Sodium Iodide Symporter Imaging and Therapy Using 188Re: A Human Glioma Study in Mice

    PubMed Central

    Guo, Rui; Zhang, M.; Xi, Yun; Ma, Yufei; Liang, Sheng; Shi, Shuo; Miao, Ying; Li, Biao

    2014-01-01

    Objective To investigate the role of 188Re in human sodium iodide symporter (hNIS) theranostic gene-mediated human glioma imaging and therapy in model mice. Methods The human glioma cell line U87 was transfected with recombinant lentivirus encoding the hNIS gene under the control of cytomegalovirus promoter (U87-hNIS). The uptake and efflux of 188Re were determined after incubating the cells with 188Re. 188Re uptake experiments in the presence of various concentrations of sodium perchlorate were carried out. In vitro cell killing tests with 188Re were performed. U87-hNIS mediated 188Re distribution, imaging and therapy in nude mice were also tested. Results U87-hNIS cell line was successfully established. The uptake of 188Re in U87-hNIS cells increased up to 26-fold compared to control cells, but was released rapidly with a half-life of approximately 4 minutes. Sodium perchlorate reduced hNIS-mediated 188Re uptake to levels of control cell lines. U87-hNIS cells were selectively killed following exposure to 188Re, with a survival of 21.4%, while control cells had a survival of 92.1%. Unlike in vitro studies, U87-hNIS tumor showed a markedly increased 188Re retention even 48 hours after 188Re injection. In the therapy study, there was a significant difference in tumor size between U87-hNIS mice (317±67 mm3) and control mice (861±153 mm3) treated with 188Re for 4 weeks (P<0.01). Conclusion The results indicate that inserting the hNIS gene into U87 cells is sufficient to induce specific 188Re uptake, which has a cell killing effect both in vitro and in vivo. Moreover, our study, based on the function of hNIS as a theranostic gene allowing noninvasive imaging of hNIS expression by 188Re scintigraphy, provides detailed characterization of in vivo vector biodistribution and level, localization, essential prerequisites for precise planning and monitoring of clinical gene therapy that aims to individualize gene therapy concept. PMID:25000403

  12. New in vitro tools to study human constitutive androstane receptor (CAR) biology: discovery and comparison of human CAR inverse agonists.

    PubMed

    Küblbeck, Jenni; Jyrkkärinne, Johanna; Molnár, Ferdinand; Kuningas, Tiina; Patel, Jayendra; Windshügel, Björn; Nevalainen, Tapio; Laitinen, Tuomo; Sippl, Wolfgang; Poso, Antti; Honkakoski, Paavo

    2011-12-01

    The human constitutive androstane receptor (CAR, NR1I3) is one of the key regulators of xenobiotic and endobiotic metabolism. The unique properties of human CAR, such as the high constitutive activity and the complexity of signaling, as well as the lack of functional and predictive cell-based assays to study the properties of the receptor, have hindered the discovery of selective human CAR ligands. Here we report a novel human CAR inverse agonist, 1-[(2-methylbenzofuran-3-yl)methyl]-3-(thiophen-2-ylmethyl) urea (S07662), which suppresses human CAR activity, recruits the corepressor NCoR in cell-based assays, and attenuates the phenytoin- and 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO)-induced expression of CYP2B6 mRNA in human primary hepatocytes. The properties of S07662 are also compared with those of known human CAR inverse agonists by using an array of different in vitro and in silico assays. The identified compound S07662 can be used as a chemical tool to study the biological functions of human CAR and also as a starting point for the development of new drugs for various conditions involving the receptor. PMID:22044162

  13. Netupitant PET imaging and ADME studies in humans

    PubMed Central

    Spinelli, Tulla; Calcagnile, Selma; Giuliano, Claudio; Rossi, Giorgia; Lanzarotti, Corinna; Mair, Stuart; Stevens, Lloyd; Nisbet, Ian

    2014-01-01

    Netupitant is a new, selective NK1 receptor antagonist under development for the prevention of chemotherapy-induced nausea and vomiting. Two studies were conducted to evaluate the brain receptor occupancy (RO) and disposition (ADME) of netupitant in humans. Positron emission tomography (PET) imaging with the NK1 receptor-binding–selective tracer [11C]-GR205171 was used to evaluate the brain penetration of different doses of netupitant (100, 300, and 450?mg) and to determine the NK1-RO duration. A NK1-RO of 90% or higher was achieved with all doses in the majority of the tested brain regions at Cmax, with a long duration of RO. The netupitant minimal plasma concentration predicted to achieve a NK1-RO of 90%, C90%, in the striatum was 225?ng/mL; after administration of netupitant 300?mg, concentrations exceeded the C90%. In the ADME study, a single nominal dose of [14C]-netupitant 300?mg was used to assess its disposition. Absorption was rapid and netupitant was extensively metabolized via Phase I and II hepatic metabolism. Elimination of >90% was predicted at day 29 and was principally via hepatic/biliary route (>85%) with a minor contribution of the renal route (<5%). In conclusion, these studies demonstrate that netupitant is a potent agent targeting NK1 receptors with long lasting RO. In addition, netupitant is extensively metabolized and is mainly eliminated through the hepatic/biliary route and to a lesser extent via the kidneys. PMID:24122871

  14. Parasitological and clinical studies on human scabies in Cairo.

    PubMed

    Sarwat, M A; el Okbi, L M; el Sayed, M M; el Okbi, S M; el Deeb, H K

    1993-12-01

    This study is a parasitological and clinical study on human scabies. This study was carried out on 100 patients attending the Dermatology Outpatient Clinic at Ain Shams University Hospitals, including 54 males and 46 females. All patients were subjected to detailed history taking, complete dermatological examination including Skin Scraping Test and Burrow Ink Test. Younger patients attended the dermatology clinic earlier than older patients, who usually delayed their visits until complications occurred. Scratching, erythematous papules and secondary infected lesions were the commonest lesions. The hands, wrist and external genitalia were the most frequently affected sites while the feet, ankles, knees and back were the least affected. Burrows could only be detected in 40% of patients. The most frequent sites were the web spaces, external genitalia, and finger sides. Burrow Ink Test was positive among 85% of patients with burrows while mites could be identified by Skin Scraping Test in 55% of patients. The most frequent clinical manifestations in the parasitologically positive patients were itching, burrows, and papules, and the most frequent sites were the web spaces, and the finger sides. Multiple sites affection was the characteristic feature among the preschool age children who represented 14% of cases. PMID:8308357

  15. Threshold tracking techniques in the study of human peripheral nerve.

    PubMed

    Bostock, H; Cikurel, K; Burke, D

    1998-02-01

    Conventional electrophysiological tests of nerve function focus on the number of conducting fibers and their conduction velocity. These tests are sensitive to the integrity of the myelin sheath, but provide little information about the axonal membrane. Threshold tracking techniques, in contrast, test nerve excitability, which depends on the membrane properties of the axons at the site of stimulation. These methods are sensitive to membrane potential, and to changes in membrane potential caused by activation of ion channels and electrogenic ion pumps, including those under the myelin sheath. This review describes the range of threshold tracking techniques that have been developed for the study of human nerves in vivo: resting threshold is compared with the threshold altered by a change in environment (e.g., ischemia), by a preceding single impulse (e.g., refractoriness, superexcitability) or impulse train, or by a subthreshold current (e.g., threshold electrotonus). Few clinical studies have been reported so far, mainly in diabetic neuropathy and motor neuron disease. Threshold measurements seem well suited for studies of metabolic and toxic neuropathies but insensitive to demyelination. Until suitable equipment becomes more widely available, their full potential is unlikely to be realized. PMID:9466589

  16. A Proteomic Study of Human Merkel Cell Carcinoma

    PubMed Central

    Shao, Qiang; Byrum, Stephanie D.; Moreland, Linley E.; Mackintosh, Samuel G.; Kannan, Aarthi; Lin, Zhenyu; Morgan, Michael; Stack, Brendan C.; Cornelius, Lynn A.; Tackett, Alan J.; Gao, Ling

    2014-01-01

    Merkel Cell Carcinoma (MCC) is an aggressive neuroendocrine cancer of the skin. The incidence has been quadrupled with a 5-year mortality rate of 46%, presently there is no cure for metastatic disease. Despite the contribution of Merkel cell polyomavirus, the molecular events of MCC carcinogenesis are poorly defined. To better understand MCC carcinogensis, we have performed the first quantitative proteomic comparison of formalin-fixed, paraffin-embedded (FFPE) MCC tissues using another neuroendocrine tumor (carcinoid tumor of the lung) as controls. Bioinformatic analysis of the proteomic data has revealed that MCCs carry distinct protein expression patterns. Further analysis of significantly over-expressed proteins suggested the involvement of MAPK, PI3K/Akt/mTOR, wnt, and apoptosis signaling pathways. Our previous study and that from others have shown mTOR activation in MCCs. Therefore, we have focused on two downstream molecules of the mTOR pathway, lactate dehydrogenase B (LDHB) and heterogeneous ribonucleoprotein F (hnRNPF). We confirm over-expression of LDHB and hnRNPF in two primary human MCC cell lines, 16 fresh tumors, and in the majority of 80 tissue microarray samples. Moreover, mTOR inhibition suppresses LDHB and hnRNPF expression in MCC cells. The results of the current study provide insight into MCC carcinogenesis and provide rationale for mTOR inhibition in pre-clinical studies. PMID:25284964

  17. Keyhole limpet haemocyanin - a model antigen for human immunotoxicological studies.

    PubMed

    Swaminathan, Ashwin; Lucas, Robyn M; Dear, Keith; McMichael, Anthony J

    2014-11-01

    Immunization with a T-cell dependent antigen has been promoted as a reliable and sensitive tool for assessing the influence of putative immunotoxic exposures or agents on immune function. Keyhole limpet haemocyanin (KLH) is a very large, copper-containing protein molecule derived from the haemolymph of the inedible mollusc, Megathura crenulata. KLH is a highly immunogenic T-cell dependent antigen that is used increasingly in immunotoxicological studies, particularly in those involving animals. This report systematically reviews the human clinical studies that have used trans-cutaneous KLH immunization for assessment of the influence of various physiological and disease states and exposures on immune function over the last 20 years (1994-2013). These studies varied in their immunization protocols, formulation of KLH, dose, site and route of administration and immunoassay platforms developed to assess KLH-specific responses. KLH immunization has been well tolerated with only mild to moderate adverse effects reported. Though very promising as a model antigen candidate in immunotoxicology research, more work on standardizing immunization and immunoassay protocols is required. PMID:24833186

  18. Modified antigen-binding of human antibodies with glycosylation variations of the light chains produced in sugar-limited human hybridoma cultures

    Microsoft Academic Search

    Hirofumi Tachibana; Kim Jiyoun; Kiyotaka Taniguchi; Yoshitaka Ushio; Kiichiro Teruya; Kazuhiro Osada; Yuichi Inoue; Sanetaka Shirahata; Hiroki Murakami

    1996-01-01

    Summary  We have characterized the effects of serum andN-acetylglucosamine in a glucose-deprived condition on the glycosylation of antibody light chains, as well as the resulting\\u000a biological properties of those antibodies. We have chosen for our investigation the human hybridoma lines producing monoclonal\\u000a antibodies reactive to lung adenocarcinoma. Each antibody possess aN-glycosylated carbohydrate chain in the hypervariable region of the light chains.

  19. A study and investigation of human error in time study observations

    E-print Network

    Case, Richard Blanch

    1954-01-01

    the ex~sent? . Hewevei?' due to the. ~- ed. length of 'time 'required for each oj~ativ'e' study: and the limited time eich observex' could devote to the study?. a diverse group of observers had to be used at different intex . vale? . 'fheso observirs...HUHAH EBB OR XH TX NE STUDY LI 8 ftARQ A k jH COLLEGE QF TEXAS A STUDY AItD I?VESTIGATIOS OIA ITUMAN ZBRQR T8 TIT& STUDY OBSERVATIONS Aprkoultural and. Nechauical College of Texas Iu'pargial fulfillment of the" reguiremeute for the Ce...

  20. Limits on quark-lepton compositeness and studies of W asymmetry at the Tevatron collider

    SciTech Connect

    Bodek, A.

    1996-10-01

    Drell-Yan dilepton production at high invariant mass place strong limits on quark substructure. Compositeness limits from CDF Run 1, and expected sensitivity in Run II and TEV33 are presented. The W asymmetry data constrains the slope of the d/u quark distributions and significantly reduces the systematic error on the extracted value of the W mass.

  1. A feasibility study for a fault current limiter to reduce voltage sags at sensible loads

    Microsoft Academic Search

    Hector G. Sarmiento; C. Tovar; E. Molero

    1995-01-01

    In relatively weak networks, a fault occurring in any part of the network causes voltage sags to appear in different nodes, more severely in those adjacent to the fault. One way to reduce these voltage sags to acceptable values can be achieved by limiting the fault current in the distribution feeders. A fault current limiter is defined as a series

  2. Correction of the aberrations in the human eye with a liquid-crystal spatial light modulator: limits to performance

    Microsoft Academic Search

    Fernando Vargas-Martín; Pedro M. Prieto; Pablo Artal

    1998-01-01

    We evaluated the performance of a liquid-crystal spatial light modulator for static correction of the aberrations in the human eye. By applying phase-retrieval techniques to pairs of double-pass images we first estimated the wave aberration of the eye to be corrected. Then we introduced the opposite phase map in the modulator, which was placed in a plane conjugated with the

  3. Hairless Mouse Skin is Limited as a Model for Assessing the Effects of Penetration Enhancers in Human Skin

    Microsoft Academic Search

    John Russell Bond; Brian William Barry

    1988-01-01

    The permeability coefficient of 5-fluorouracil through human abdominal and hairless mouse skins was used as an indicator of the relative effects of 12-h pretreatment of the skins with either penetration-enhancer mixtures [including laurocapram (Azone), decylmethylsulfoxide, oleic acid, and propylene glycol] or saline (control). After treatment with saline, fluxes of 5-fluorouracil through the two skin types were similar, but the mouse

  4. Voice-Activated Lightweight Reacher to Assist with Upper Extremity Movement Limitations: A Case Study.

    PubMed

    Khalid, Umer; Conti, Gerry E; Erlandson, Robert F; Ellis, Richard D; Brown, Vince; Pandya, Abhilash K

    2015-01-01

    The focus of this research was to design a functional and user-friendly reacher for people with spinal cord injuries (SCIs). Engineering advancements have taken assistive robotics to new dimensions. Technologies such as wheelchair robotics and myo-electronically controlled systems have opened up a wide range of new applications to assist people with physical disabilities. Similarly, exo-skeletal limbs and body suits have provided new foundations from which technologies can aid function. Unfortunately, these devices have issues of usability, weight, and discomfort with donning. The Smart Assistive Reacher Arm (SARA) system, developed in this research, is a voice-activated, lightweight, mobile device that can be used when needed. SARA was built to help overcome daily reach challenges faced by individuals with limited arm and hand movement capability, such as people with cervical level 5-6 (C5-6) SCI. This article shows that a functional reacher arm with voice control can be beneficial for this population. Comparison study with healthy participants and an SCI participant shows that, when using SARA, a person with SCI can perform simple reach and grasp tasks independently, without someone else's help. This suggests that the interface is intuitive and can be easily used to a high level of proficiency by a SCI individual. PMID:26132355

  5. Comparative study of the effectiveness and limitations of current methods for detecting sequence coevolution

    PubMed Central

    Mao, Wenzhi; Kaya, Cihan; Dutta, Anindita; Horovitz, Amnon; Bahar, Ivet

    2015-01-01

    Motivation: With rapid accumulation of sequence data on several species, extracting rational and systematic information from multiple sequence alignments (MSAs) is becoming increasingly important. Currently, there is a plethora of computational methods for investigating coupled evolutionary changes in pairs of positions along the amino acid sequence, and making inferences on structure and function. Yet, the significance of coevolution signals remains to be established. Also, a large number of false positives (FPs) arise from insufficient MSA size, phylogenetic background and indirect couplings. Results: Here, a set of 16 pairs of non-interacting proteins is thoroughly examined to assess the effectiveness and limitations of different methods. The analysis shows that recent computationally expensive methods designed to remove biases from indirect couplings outperform others in detecting tertiary structural contacts as well as eliminating intermolecular FPs; whereas traditional methods such as mutual information benefit from refinements such as shuffling, while being highly efficient. Computations repeated with 2,330 pairs of protein families from the Negatome database corroborated these results. Finally, using a training dataset of 162 families of proteins, we propose a combined method that outperforms existing individual methods. Overall, the study provides simple guidelines towards the choice of suitable methods and strategies based on available MSA size and computing resources. Availability and implementation: Software is freely available through the Evol component of ProDy API. Contact: bahar@pitt.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25697822

  6. Belief, Awareness, and Limited Reasoning

    Microsoft Academic Search

    Ronald Fagin; Joseph Y. Halpern

    1987-01-01

    Several new logics for belief and knowledge are introduced and studied, all of which have the property that agents are not logically omniscient. In particular, in these logics, the set of beliefs of an agent does not necessarily contain all valid formulas. Thus, these logics are more suitable than traditional logics for modelling beliefs of humans (or machines) with limited

  7. The limits of technological optimism

    Microsoft Academic Search

    Andrew D. Basiago

    1994-01-01

    Summary ‘Technological optimism’ is the doctrine that a growing number of technological improvements in such areas as food production, environmental quality and energy will sustain life as human population soars. It evolved as a response to the Malthusian study The Limits to Growth (The Club of Rome, 1972). Like population biologist Paul Ehrlich, Professor James Krier of the University of

  8. Characterizing human retinotopic mapping with conformal geometry: a preliminary study

    NASA Astrophysics Data System (ADS)

    Ta, Duyan; Shi, Jie; Barton, Brian; Brewer, Alyssa; Lu, Zhong-Lin; Wang, Yalin

    2014-03-01

    Functional magnetic resonance imaging (fMRI) has been widely used to measure the retinotopic organization of early visual cortex in the human brain. Previous studies have identified multiple visual field maps (VFMs) based on statistical analysis of fMRI signals, but the resulting geometry has not been fully characterized with mathematical models. Here we test whether VFMs V1 and V2 obey the least restrictive of all geometric mappings; that is, whether they are anglepreserving and therefore maintain conformal mapping. We measured retinotopic organization in individual subjects using standard traveling-wave fMRI methods. Visual stimuli consisted of black and white, drifting checkerboards comprising rotating wedges and expanding rings to measure the cortical representations of polar angle and eccentricity, respectively. These representations were then projected onto a 3D cortical mesh of each hemisphere. By generating a mapped unit disk that is conformal of the VFMs using spherical stereographic projection and computing the parameterized coordinates of the eccentricity and polar angle gradients, we computed Beltrami coefficients to check whether the mapping from the visual field to the V1 and V2 cortical representations is conformal. We find that V1 and V2 exhibit local conformality. Our analysis of the Beltrami coefficient shows that selected regions of V1 and V2 that contain reasonably smooth eccentricity and polar angle gradients do show significant local conformality, warranting further investigation of this approach for analysis of early and higher visual cortex. These results suggest that such a mathematical model can be used to characterize the early VFMs in human visual cortex.

  9. Molecular and Supramolecular Structural Studies on Human Tropoelastin Sequences

    PubMed Central

    Ostuni, Angela; Bochicchio, Brigida; Armentano, Maria F.; Bisaccia, Faustino; Tamburro, Antonio M.

    2007-01-01

    One of the unusual properties of elastin is its ability to coacervate, which has been proposed to play an important role in the alignment of monomeric elastin for cross-linking into the polymeric elastin matrix. The temperature at which this transition takes place depends on several factors including protein concentration, ionic strength, and pH. Previously, polypeptide sequences encoded by different exons of the human tropoelastin gene have been analyzed for their ability to coacervate and to self-assemble. Few of them were indeed able to coacervate and only one, that encoded by exon 30 (EX30), gave amyloid fibers. In this article, we report on two chemically synthesized peptides—a decapeptide and an octadecapeptide—whose sequences are contained in the longer EX30 peptide and on a polypeptide (EX1–7) of 125 amino-acid residues corresponding to the sequence coded by the exons 1–7 and on a polypeptide (EX2–7) of 99 amino-acid residues encoded by exons 2–7 of human tropoelastin obtained by recombinant DNA techniques. Molecular and supramolecular structural characterization of these peptides showed that a minimum sequence of ?20 amino acids is needed to form amyloid fibers in the exon 30-derived peptides. The N-terminal region of mature tropoelastin (EX2–7) gives rise to a coacervate and forms elastinlike fibers, whereas the polypeptide sequence containing the signal peptide (EX1–7) forms mainly amyloid fibers. Circular dichroism spectra show that ?-structure is ubiquitous in all the sequences studied, suggesting that the presence of a ?-structure is a necessary, although not sufficient, requirement for the appearance of amyloid fibers. PMID:17693470

  10. Modeling aspects of human memory for scientific study.

    SciTech Connect

    Caudell, Thomas P. (University of New Mexico); Watson, Patrick (University of Illinois - Champaign-Urbana Beckman Institute); McDaniel, Mark A. (Washington University); Eichenbaum, Howard B. (Boston University); Cohen, Neal J. (University of Illinois - Champaign-Urbana Beckman Institute); Vineyard, Craig Michael; Taylor, Shawn Ellis; Bernard, Michael Lewis; Morrow, James Dan; Verzi, Stephen J.

    2009-10-01

    Working with leading experts in the field of cognitive neuroscience and computational intelligence, SNL has developed a computational architecture that represents neurocognitive mechanisms associated with how humans remember experiences in their past. The architecture represents how knowledge is organized and updated through information from individual experiences (episodes) via the cortical-hippocampal declarative memory system. We compared the simulated behavioral characteristics with those of humans measured under well established experimental standards, controlling for unmodeled aspects of human processing, such as perception. We used this knowledge to create robust simulations of & human memory behaviors that should help move the scientific community closer to understanding how humans remember information. These behaviors were experimentally validated against actual human subjects, which was published. An important outcome of the validation process will be the joining of specific experimental testing procedures from the field of neuroscience with computational representations from the field of cognitive modeling and simulation.

  11. Human factors and medication errors: a case study.

    PubMed

    Gluyas, Heather; Morrison, Paul

    2014-12-15

    Human beings are error prone. A significant component of human error is flaws inherent in human cognitive processes, which are exacerbated by situations in which the individual making the error is distracted, stressed or overloaded, or does not have sufficient knowledge to undertake an action correctly. The scientific discipline of human factors deals with environmental, organisational and job factors, as well as human and individual characteristics, which influence behaviour at work in a way that potentially gives rise to human error. This article discusses how cognitive processing is related to medication errors. The case of a coronial inquest into the death of a nursing home resident is used to highlight the way people think and process information, and how such thinking and processing may lead to medication errors. PMID:25492790

  12. Placental Glucose Transfer: A Human In Vivo Study

    PubMed Central

    Holme, Ane M.; Roland, Marie Cecilie P.; Lorentzen, Bjørg; Michelsen, Trond M.; Henriksen, Tore

    2015-01-01

    Objectives The placental transfer of nutrients is influenced by maternal metabolic state, placenta function and fetal demands. Human in vivo studies of this interplay are scarce and challenging. We aimed to establish a method to study placental nutrient transfer in humans. Focusing on glucose, we tested a hypothesis that maternal glucose concentrations and uteroplacental arterio-venous difference (reflecting maternal supply) determines the fetal venous-arterial glucose difference (reflecting fetal consumption). Methods Cross-sectional in vivo study of 40 healthy women with uncomplicated term pregnancies undergoing planned caesarean section. Glucose and insulin were measured in plasma from maternal and fetal sides of the placenta, at the incoming (radial artery and umbilical vein) and outgoing vessels (uterine vein and umbilical artery). Results There were significant mean (SD) uteroplacental arterio-venous 0.29 (0.23) mmol/L and fetal venous-arterial 0.38 (0.31) mmol/L glucose differences. The transplacental maternal-fetal glucose gradient was 1.22 (0.42) mmol/L. The maternal arterial glucose concentration was correlated to the fetal venous glucose concentration (r = 0.86, p<0.001), but not to the fetal venous-arterial glucose difference. The uteroplacental arterio-venous glucose difference was neither correlated to the level of glucose in the umbilical vein, nor fetal venous-arterial glucose difference. The maternal-fetal gradient was correlated to fetal venous-arterial glucose difference (r = 0.8, p<0.001) and the glucose concentration in the umbilical artery (r = ?0.45, p = 0.004). Glucose and insulin concentrations were correlated in the mother (r = 0.52, p = 0.001), but not significantly in the fetus. We found no significant correlation between maternal and fetal insulin values. Conclusions We did not find a relation between indicators of maternal glucose supply and the fetal venous-arterial glucose difference. Our findings indicate that the maternal-fetal glucose gradient is significantly influenced by the fetal venous-arterial difference and not merely dependent on maternal glucose concentration or the arterio-venous difference on the maternal side of the placenta. PMID:25680194

  13. Genetic linkage studies of the human glycosphingolipid ?-galactosidases

    Microsoft Academic Search

    Alan R. Rushton; G. Dawson

    1977-01-01

    The genetic linkage relationships of the human glycosphingolipid ß-galactosidases were determined using human-mouse somatic cell hybrids. A new method was devised for the estimation of human galactosylceramide, lactosylceramide, and GMI-ganglioside ß-galactosidase activities in the presence of their mouse counterparts, which takes advantage of the reproducible specific activity of lysosomal hydrolases under a given set of culture conditions and is based

  14. Human genetic mapping studies using single sperm typing

    SciTech Connect

    Hubert, R.S.

    1993-01-01

    Sperm typing is a powerful technique that uses the polymerase chain reaction (PCR) to analyze DNA sequences within single sperm cells in order to construct genetic maps. This methodology was used to estimate the recombination fraction between D3S2 and D3S2 which was found to be 0.28 (95% CI = 0.20-0.36). Pedigree analysis was unable to determine genetic distance between these two markers due to their low informativeness. We also showed that dinucleotide and tetranucleotide repeat polymorphisms can be analyzed in single cells without using radioactivity or denaturing gels. This provides a rich new source of DANA polymorphisms for genetic mapping by sperm typing. In addition, an approach that uses the sperm typing methodology is described that can define the physical boundaries of meiotic recombination hotspots. The hotspot at 4p16.3 near the Huntington disease gene was localized to an interval between D4S10 and D4S126. These studies demonstrated the usefulness of sperm typing as a tool for the study of human genetic.

  15. Sphingolipids in Human Synovial Fluid - A Lipidomic Study

    PubMed Central

    Kosinska, Marta Krystyna; Liebisch, Gerhard; Lochnit, Guenter; Wilhelm, Jochen; Klein, Heiko; Kaesser, Ulrich; Lasczkowski, Gabriele; Rickert, Markus; Schmitz, Gerd; Steinmeyer, Juergen

    2014-01-01

    Articular synovial fluid (SF) is a complex mixture of components that regulate nutrition, communication, shock absorption, and lubrication. Alterations in its composition can be pathogenic. This lipidomic investigation aims to quantify the composition of sphingolipids (sphingomyelins, ceramides, and hexosyl- and dihexosylceramides) and minor glycerophospholipid species, including (lyso)phosphatidic acid, (lyso)phosphatidylglycerol, and bis(monoacylglycero)phosphate species, in the SF of knee joints from unaffected controls and from patients with early (eOA) and late (lOA) stages of osteoarthritis (OA), and rheumatoid arthritis (RA). SF without cells and cellular debris from 9 postmortem donors (control), 18 RA, 17 eOA, and 13 lOA patients were extracted to measure lipid species using electrospray ionization tandem mass spectrometry - directly or coupled with hydrophilic interaction liquid chromatography. We provide a novel, detailed overview of sphingolipid and minor glycerophospholipid species in human SF. A total of 41, 48, and 50 lipid species were significantly increased in eOA, lOA, and RA SF, respectively when compared with normal SF. The level of 21 lipid species differed in eOA SF versus SF from lOA, an observation that can be used to develop biomarkers. Sphingolipids can alter synovial inflammation and the repair responses of damaged joints. Thus, our lipidomic study provides the foundation for studying the biosynthesis and function of lipid species in health and most prevalent joint diseases. PMID:24646942

  16. Tomography studies of human foreskin fibroblasts on polymer yarns

    NASA Astrophysics Data System (ADS)

    Thurner, Philipp; Müller, Bert; Beckmann, Felix; Weitkamp, Timm; Rau, Christoph; Müller, Ralph; Hubbell, Jeffrey A.; Sennhauser, Urs

    2003-01-01

    Cell culture experiments are usually performed as in vitro studies based on 2D seeding and characterization (light microscopy). With respect to the in vivo situation, however, 2D studies are often inappropriate due to the 3D character of living tissue in nature. Textiles with their versatile 3D structures are chosen as suitable scaffolds in tissue engineering for 3D in vitro studies. Micro-computed tomography using X-rays (?CT) belongs to the most promising techniques for isotropic, noninvasive 3D characterization. Using synchrotron radiation (SR?CT) the spatial resolution can be extended to the sub-micrometer range well below cell size. ?CT does not need vacuum conditions making experiments in the hydrated state possible, as we show by data from SR?CT acquired at second and third-generation synchrotron sources. We seeded human foreskin fibroblasts on polymer multifilament yarns. These composites, embedded in a hydrogel or fluid, are held in thin-walled glass capillaries. Since the composites consist of light elements, the cells have to be labeled for visualization by the use of highly absorptive agents, osmium and gold. In order to hold the label concentration as low as possible, we present a way to choose the photon energy for which the minimum concentration is reached. Differences in threshold selection for second- and third-generation synchrotron sources are pointed out, revealing the advantages of both types with respect to quantitative analysis. The study is based on appropriate staining methods and protocols developed in our laboratory. With the results we demonstrate that SR?CT yields images similar to established electron and light microscopy but uncovers also the microstructure in 3D space.

  17. Intracerebral study of gamma oscillations in the human sensorimotor cortex.

    PubMed

    Szurhaj, William; Derambure, Philippe

    2006-01-01

    Since few years, gamma oscillations have given rise to an increasing interest. They have been successively described as being involved in cognitive function and various sensory systems. However, their role remains the subject of much debate. Gamma rhythms are difficult to study in scalp recordings due to low amplitudes and because the skull filters out high-frequency signals. Hence, their study makes necessary intracerebral recordings. Here, we report our intracerebral data issuing from study of gamma oscillations in the human sensorimotor cortex during the preparation and execution of voluntary movements. These studies have been performed in epileptic patients explored by stereoelectroencephalography (SEEG). Whereas mu and beta rhythms reactivity was diffused, the gamma rhythm reactivity to the movement was very focused and was observed predominantly in the primary sensorimotor areas that were involved in the movement, as assessed by the electrical cortical stimulations. Gamma oscillations seemed to be related to the movement execution rather than to the movement preparation. We have compared the temporo-spatial relationships between movement-related cortical potentials (MRCPs) and sensorimotor rhythms. We show that (i) the late components of MRCPs (motor potential--MP and post-movement complex--PMc) and the gamma event-related synchronization (ERS) within the 40-60-Hz band always occurred in the same contacts (located in the primary sensorimotor areas) and (ii) the PMc peaked during the gamma ERS, whereas the MP began before it. The PMc, so-called 'Reafferent Potential', is supposed to reflect the somesthetic reafferentation of the sensorimotor cortex. Hence, it seems that the PMc and the gamma ERS represent two electrophysiological facets of the reafferentation of the cortex during the movement. We suggest that gamma oscillations within the 40-60-Hz band serve to facilitate kinesthesic afferences from the muscles and joints involved in the movement to the primary sensorimotor cortex, which would be necessary for controlling the ongoing movement. PMID:17071239

  18. An immortalized human blood-nerve barrier endothelial cell line for in vitro permeability studies

    PubMed Central

    Yosef, Nejla; Ubogu, Eroboghene E.

    2012-01-01

    Solute and macromolecular transport studies may elucidate nutritional requirements and drug effects in healthy and diseased peripheral nerves. Endoneurial endothelial cells are specialized microvascular cells that form the restrictive blood-nerve barrier (BNB). Primary human endoneurial endothelial cells (pHEndECs) are difficult to isolate, limiting their widespread availability for biomedical research. We developed a simian virus-40 large T-antigen (SV40-LTA) immortalized human BNB cell line via stable transfection of low passage pHEndECs and observed continuous growth in culture for >45 population doublings. As observed with pHEndECs, the immortalized BNB endothelial cells were Ulex Europaeus agglutinin-1 (UEA-1)-positive and endocytosed low density lipoprotein, but lost von Willebrand factor (vWF) expression. Glucose transporter-1 (GLUT-1), P-glycoprotein (P-gp), ?-glutamyl transpeptidase (?-GT), large neutral amino acid transporter-1 (LAT-1), creatine transporter (CRT) and monocarboxylate transporter-1 (MCT-1) mRNA expression were retained at all passages with loss of alkaline phosphatase (AP) expression after passages 16-20. Compared with an SV40-LTA immortalized human blood-brain barrier (BBB) endothelial cell line, there was increased ?-GT protein expression, equivalent expression of organic anion transporting polypeptide-C (OATP-C), organic anion transporter 3 (OAT-3), MCT-1 and LAT-1, and reduced expression of AP, CRT and P-gp by the BNB cell line at passage 20. Further studies demonstrated lower transendothelial electrical resistance (TEER: ~181 ?.cm2 vs. 191 ?.cm2), equivalent permeability to fluoresceinated sodium (4.84% vs. 4.39%) and lower permeability to fluoresceinated high molecular weight (70 kDa) dextran (0.39% vs. 0.52%) by the BNB cell line. This cell line retained essential molecular and biophysical properties suitable for in vitro peripheral nerve permeability studies. PMID:23104242

  19. An immortalized human blood-nerve barrier endothelial cell line for in vitro permeability studies.

    PubMed

    Yosef, Nejla; Ubogu, Eroboghene E

    2013-03-01

    Solute and macromolecular transport studies may elucidate nutritional requirements and drug effects in healthy and diseased peripheral nerves. Endoneurial endothelial cells are specialized microvascular cells that form the restrictive blood-nerve barrier (BNB). Primary human endoneurial endothelial cells (pHEndECs) are difficult to isolate, limiting their widespread availability for biomedical research. We developed a simian virus-40 large T-antigen (SV40-LTA) immortalized human BNB cell line via stable transfection of low passage pHEndECs and observed continuous growth in culture for >45 population doublings. As observed with pHEndECs, the immortalized BNB endothelial cells were Ulex Europaeus agglutinin-1-positive and endocytosed low density lipoprotein, but lost von Willebrand factor expression. Glucose transporter-1, P-glycoprotein (P-gp), ?-glutamyl transpeptidase (?-GT), large neutral amino acid transporter-1 (LAT-1), creatine transporter (CRT), and monocarboxylate transporter-1 (MCT-1) mRNA expression were retained at all passages with loss of alkaline phosphatase (AP) expression after passages 16-20. Compared with an SV40-LTA immortalized human blood-brain barrier endothelial cell line, there was increased ?-GT protein expression, equivalent expression of organic anion transporting polypeptide-C (OATP-C), organic anion transporter 3 (OAT-3), MCT-1, and LAT-1, and reduced expression of AP, CRT, and P-gp by the BNB cell line at passage 20. Further studies demonstrated lower transendothelial electrical resistance (~181 vs. 191 ? cm(2)), equivalent permeability to fluoresceinated sodium (4.84 vs. 4.39 %), and lower permeability to fluoresceinated high molecular weight (70 kDa) dextran (0.39 vs. 0.52 %) by the BNB cell line. This cell line retained essential molecular and biophysical properties suitable for in vitro peripheral nerve permeability studies. PMID:23104242

  20. Additional road markings as an indication of speed limits: results of a field experiment and a driving simulator study.

    PubMed

    Daniels, Stijn; Vanrie, Jan; Dreesen, An; Brijs, Tom

    2010-05-01

    Although speed limits are indicated by road signs, road users are not always aware, while driving, of the actual speed limit on a given road segment. The Roads and Traffic Agency developed additional road markings in order to support driver decisions on speed on 70 km/h roads in Flanders-Belgium. In this paper the results are presented of two evaluation studies, both a field study and a simulator study, on the effects of the additional road markings on speed behaviour. The results of the field study showed no substantial effect of the markings on speed behaviour. Neither did the simulator study, with slightly different stimuli. Nevertheless an effect on lateral position was noticed in the simulator study, showing at least some effect of the markings. The role of conspicuity of design elements and expectations towards traffic environments is discussed. Both studies illustrate well some strengths and weaknesses of observational field studies compared to experimental simulator studies. PMID:20380925

  1. Study of the adhesion of Bifidobacterium bifidum MIMBb75 to human intestinal cell lines.

    PubMed

    Guglielmetti, Simone; Tamagnini, Isabella; Minuzzo, Mario; Arioli, Stefania; Parini, Carlo; Comelli, Elena; Mora, Diego

    2009-08-01

    The aim of this study was to investigate the adhesive phenotype of the human intestinal isolate Bifidobacterium bifidum MIMBb75 to human colon carcinoma cell lines. We have previously shown that the adhesion of this strain to Caco-2 cells is mediated by an abundant surface lipoprotein named BopA. In this study, we found that this strain adheres to Caco-2 and HT-29 cells, and that its adhesion strongly depends on the environmental conditions, including the presence of sugars and bile salts and the pH. Considerably more adhesion to a Caco-2 monolayer occurred in the presence of fucose and mannose and less when MIMBb75 grew in Oxgall bile salts compared to standard environmental conditions. In particular, growth in Oxgall bile salts reduced the adhesion ability of MIMBb75 and modified the SDS-PAGE profile of the cell wall associated proteins of the strain. The pH markedly affected both adhesion to Caco-2 and bacterial autoaggregation. Finally, experiments with sodium metaperiodate suggested that not only proteinaceous determinants are involved in the adhesion process of B. bifidum. In conclusion, it seems that the colonization strategy of this bacterium can be influenced by factors varying along the gastrointestinal tract, such as the presence of specific sugars and bile salts and the pH, possibly limiting the adhesion of B. bifidum to only restricted distal sites of the gut. PMID:19452211

  2. International Journal of Human-Computer Studies, 62, 105-125 (2005). INTERFACE CHANGES CAUSING ACCIDENTS. AN EMPIRICAL STUDY OF

    E-print Network

    Paris-Sud XI, Université de

    2005-01-01

    International Journal of Human-Computer Studies, 62, 105-125 (2005). INTERFACE CHANGES CAUSING in "International Journal of Human-Computer Studies 62, 1 (2005) Pages 105-125" DOI : 10.1016/j.ijhcs.2004 ACCIDENTS. AN EMPIRICAL STUDY OF NEGATIVE TRANSFER Denis BESNARD School of Computing Science University

  3. Determination of industrial color tolerance limits: case studies in the textile industry

    NASA Astrophysics Data System (ADS)

    Gay, Jennifer; Hirschler, Robert

    2002-06-01

    The approach and findings during the application of instrumental color quality control in industry are described, where the best tolerance formulae and tolerance limits were determined by correlating visual and instrumental evaluations. A panel of previously tested observers evaluated a collection of samples taken from production and color measurements are then compared to these assessments, according to different color difference formulae. T he formula and the limit giving the best agreement with visual evaluations were determined with two different methods. For a large variety of textile substrates, processes and market situations the CMC(2:1) formula was always the best or one of the bests, but the limits varied widely, according to the individual application. Additional shade sorting, based on the tolerance limit, was also applied in several companies. The ideal box size was also determined by comparing visual and instrumental evaluations. The application as logistical tools was established according to individual necessities.

  4. [Possibilities and limitations of fibroblast cultures in the study of animal aging].

    PubMed

    Van Gansen, P; Van Lerberghe, N

    1987-01-01

    INTRODUCTION. Aging--the effect of time--occurs in every living organism. Senescence is the last period of the lifespan, leading to death. It happens in all animals, with the exception of a few didermic species (Hydras) having a stock of embryonic cells and being immortal. The causes of animal senescence are badly known. They depend both on genetic characters (maximal lifespan of a species) and on medium factors (mean expectation of life of the animals of a species). Animal senescence could depend on cell aging: 1) by senescence and death of the differentiated cells, 2) by modified proliferation and differentiation of the stem cells of differentiated tissues, 3) by alterations in the extracellular matrices, 4) by interactions between factors 1) 2) and 3) in each tissue, 5) by interactions between the several tissues of an organism. This complexity badly impedes the experimental study of animal senescence. Normal mammal cells are aging when they are cultivated (in vitro ageing): their phenotype varies and depends on the cell generation (in vitro differentiation); the last cell-generation doesn't divide anymore and declines until death of the culture (in vitro senescence). Analysis of these artificial but well controlled systems allows an experimental approach of the proliferation, differentiation, senescence and death of the cells and of the extracellular matrix functions. Present literature upon in vitro aging of cultivated human cells is essentially made of papers where proliferation and differentiation characteristics are compared between early ("young") and late ("old") cell-generations of the cultures. FIBROBLASTIC CELLS OF THE MOUSE SKIN. This cell type has been studied in our laboratory, using different systems: 1) Primary cultures isolated from peeled skins of 19 day old mouse embryos, 2) Mouse dermis analyzed in the animals, 3) Cultivated explants of skins, 4) Serial sub-cultures of fibroblasts isolated from these explants, 5) Cells cultivated comparably on plane substrates (glass, plastic, collagen films) and on tridimensional matrices (collagen fibres). Systems 2), 3), 4) and 5) have been obtained either from 19 day old embryos or from 6 groups of animals of different ages (from 1/2 till 25 month). In primary cultures (system 1) all the cell generations have been analyzed, including the last one until death of the culture. We have shown that many characters are varying with cell-generation: cell form and cell mass, rate of DNA replication and cell division, rate of RNA transcription, nature of the accumulated and of the synthetized proteins, organization of the cytoskeletal elements, organization of the extracellular matrix, type of cell death.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3079271

  5. Extrapolation of animal studies to the human situation

    Microsoft Academic Search

    John A. Zapp Jr

    1977-01-01

    Every extrapolation involves a conjectured knowledge of an unknown area by inferences based on an assumed parallelism between it and what is known. In the present case we are interested in knowing what effect certain chemicals might have on humans. If the effects have been observed in humans, they can be described. If they have not been observed and described,

  6. Automated Essay Scoring versus Human Scoring: A Comparative Study

    ERIC Educational Resources Information Center

    Wang, Jinhao; Brown, Michelle Stallone

    2007-01-01

    The current research was conducted to investigate the validity of automated essay scoring (AES) by comparing group mean scores assigned by an AES tool, IntelliMetric [TM] and human raters. Data collection included administering the Texas version of the WriterPlacer "Plus" test and obtaining scores assigned by IntelliMetric [TM] and by human

  7. Human exposure to traffic pollution. Experience from Danish studies

    Microsoft Academic Search

    Ole Hertel; Steen Solvang Jensen; Helle Vibeke Andersen; Finn Palmgren; Peter Wåhlin; Henrik Skov; Ivan Vejsgaard Nielsen; Mette Sørensen; Steffen Loft; Ole Raaschou-Nielsen

    2001-01-01

    Air pollution may have severe long-term as well as short-term health effects. The determination of possible links between pollution levels and impact on human health is, how- ever, not a straightforward task. A key problem is the assessment of human exposure to ambi- ent pollution levels. In later years, the possible role of particulate pollution as a health haz- ard

  8. Studies Plan Humanities and Social Sciences 2013-14

    E-print Network

    ) SHS Barazzetti Poltier 2h 1h Win During the semester 3 Digital humanities I E HUM-433(a) SHS Kaplan 2h-412(b) SHS Barazzetti Poltier 3h Sum During the semester 3 Digital humanities II E HUM-433(b) SHS

  9. Limiting dilution analysis of the human T cell response to mycobacterial antigens from BCG vaccinated individuals and leprosy patients.

    PubMed Central

    Brett, S J; Kingston, A E; Colston, M J

    1987-01-01

    The number of peripheral blood T lymphocytes responding to soluble mycobacterial antigens from Mycobacterium tuberculosis purified protein derivative (PPD) and M. leprae (MLS) was estimated by limiting dilution analysis. Antigen-induced lymphocyte activation was measured by means of [3H]TdR incorporation on day 10 of culture in the presence of suboptimal concentrations of interleukin 2 (IL-2). In the peripheral blood of BCG-vaccinated individuals from the UK, the frequency of T lymphocytes responding to PPD was 1.5 to 4 times greater than to MLS. Frequencies between 1/1970 and 1/13, 982 were observed in response to PPD and between 1/4097 and 1/24, 717 in response to MLS. A proportion of cells in the peripheral blood were also observed to respond to IL-2 only. The frequency of cells observed in limiting dilution analysis for PPD and MLS reflected the relative amounts of proliferation to these two antigens in bulk culture lymphocyte transformation tests. Use of PPD-specific T cell lines suggested that the responsiveness observed to M. leprae antigens in BCG-vaccinated individuals was due to cross-reactivity with antigens shared with M. bovis BCG. In tuberculoid leprosy, the frequency of peripheral blood T lymphocytes responding to M. leprae antigens was either greater than or similar to the frequency of T cells responding to PPD. In contrast, limiting dilution analysis of T lymphocytes from the peripheral blood of lepromatous leprosy patients revealed the complex regulatory heterogeneity of this group. In some patients M. leprae responsive T cells were detected in the presence of exogenous IL-2. PMID:3308217

  10. Comparative outcome studies of clinical decision support software: limitations to the practice of evidence-based system acquisition.

    PubMed

    Dhiman, Gaurav Jay; Amber, Kyle T; Goodman, Kenneth W

    2015-04-01

    Clinical decision support systems (CDSSs) assist clinicians with patient diagnosis and treatment. However, inadequate attention has been paid to the process of selecting and buying systems. The diversity of CDSSs, coupled with research obstacles, marketplace limitations, and legal impediments, has thwarted comparative outcome studies and reduced the availability of reliable information and advice for purchasers. We review these limitations and recommend several comparative studies, which were conducted in phases; studies conducted in phases and focused on limited outcomes of safety, efficacy, and implementation in varied clinical settings. Additionally, we recommend the increased availability of guidance tools to assist purchasers with evidence-based purchases. Transparency is necessary in purchasers' reporting of system defects and vendors' disclosure of marketing conflicts of interest to support methodologically sound studies. Taken together, these measures can foster the evolution of evidence-based tools that, in turn, will enable and empower system purchasers to make wise choices and improve the care of patients. PMID:25665704

  11. Characterization and hepatogenic differentiation of mesenchymal stem cells from human amniotic fluid and human bone marrow: A comparative study

    Microsoft Academic Search

    Yu-Bao Zheng; Zhi-Liang Gao; Chan Xie; Hai-Peng Zhu; Liang Peng; Jun-Hong Chen; Yu Tian Chong

    2008-01-01

    Since stem cells can differentiate into hepatocyte, stem cell-based therapy becomes a potential alternative treatment for terminal liver diseases. However, an appropriate source of human mesenchymal stem cells (hMSCs) for hepatocytes has not yet been clearly elucidated. The aim of the present study was to investigate the in vitro biological characterization and hepatic differentiation potential of human amniotic fluid-derived mesenchymal

  12. Cytological Studies of Human Meiosis: Sex-Specific Differences in Recombination Originate at, or Prior to,

    E-print Network

    Broman, Karl W.

    Cytological Studies of Human Meiosis: Sex-Specific Differences in Recombination Originate at is sexually dimorphic in most mammalian species, including humans, but the basis for the male recombination levels between human males and females, and to examine possible sex-specific differences

  13. Int. J. Human-Computer Studies 59 (2003) 837873 Using eye movement parameters for evaluating

    E-print Network

    Zhang, WJ "Chris"

    2003-01-01

    Int. J. Human-Computer Studies 59 (2003) 837­873 Using eye movement parameters for evaluating human June 2003; accepted 18 June 2003 Abstract A human­machine interface framework provides general categories of measures are used, namely: the performance measure; the physiological measure (the eye movement

  14. A SYNERGISTIC MODEL FOR INTERPRETING HUMAN ACTIVITIES AND EVENTS FROM VIDEO : A CASE STUDY

    E-print Network

    Bebis, George

    that an event of potential interest may go unnoticed. Robust detection and tracking of humans is a challenging1 A SYNERGISTIC MODEL FOR INTERPRETING HUMAN ACTIVITIES AND EVENTS FROM VIDEO : A CASE STUDY N This paper describes a new approach for representing, recognizing and interpreting human activity from video

  15. Human communication, mutual awareness and system dependability. Lessons learnt from air-traffic control field studies

    Microsoft Academic Search

    L. Rognin; J.-P. Blanquart

    2001-01-01

    The dependability of many complex and critical systems strongly relies on human operators, both through human reliability and human ability to handle adequately the unexpected events. This paper focuses on ergonomics field studies of air traffic control activities, and more specifically on the analyses of communication within teams of controllers. We show how operators use spontaneously the natural redundancy and

  16. Graduate Studies in Industrial and Systems Engineering Human Factors/Ergonomics

    E-print Network

    1 Graduate Studies in Industrial and Systems Engineering Human Factors/Ergonomics 2013-2014 Introduction Human Factors Engineering, also known as Ergonomics, can be briefly defined as the science and skills. At OSU, Human Factors/Ergonomics (HF/E) is composed of two broad areas: Cognitive Engineering

  17. Study of Pressure Estimation for a Human Circulatory System with a LVAD

    E-print Network

    Wu, Yi

    Study of Pressure Estimation for a Human Circulatory System with a LVAD Yi Wu1 , Paul Allaire2. Based on the state space model of human circulatory system, the mean aortic pressure can be estimated-invasive evaluation of left ventricular function and properties of human circulatory system. Keywords: Cardiovascular

  18. On a Theoretical Study of the Properties of Solutions of the Limit Problem for a Magnetically Noninsulated Diode

    Microsoft Academic Search

    A. V. Sinitsyn; E. V. Dulov

    2005-01-01

    In this paper, we study the lower and upper bounds for solutions of the limit problem for the plane vacuum diode in the magnetic field in the statement by N. Ben Abdallah, P. Degond, and F. Mehats. This problem was finally set by physicists in the late 1980s and was extensively studied by numerous mathematicians in the 1990s.

  19. A numerical study of the small dispersion limit of the Korteweg-de Vries equation and asymptotic solutions

    NASA Astrophysics Data System (ADS)

    Grava, T.; Klein, C.

    2012-12-01

    We study numerically the small dispersion limit for the Korteweg-de Vries (KdV) equation ut+6uux+?2uxxx=0 for ??1 and give a quantitative comparison of the numerical solution with various asymptotic formulae for small ? in the whole (x,t)-plane. The matching of the asymptotic solutions is studied numerically.

  20. Spectroscopic study on binding of rutin to human serum albumin

    NASA Astrophysics Data System (ADS)

    Pastukhov, Alexander V.; Levchenko, Lidiya A.; Sadkov, Anatoli P.

    2007-10-01

    Steady-state and time-resolved fluorescence spectroscopy techniques were used to study the interaction of the flavonoid rutin with human serum albumin (HSA) as well as spectral properties of the protein-bound flavonoid. Both quenching of the intrinsic fluorescence of the protein (Trp214) and the ligand fluorescence, appearing upon complexation with HSA, were used to determine binding parameters. The binding constant determined from the quenching of the Trp214 fluorescence by rutin is equal to 6.87 ± 0.22 × 10 4 M -1 and that obtained from the fluorescence of HSA-bound rutin is 3.8 ± 0.4 × 10 4 M -1. Based on the Job plot analysis, the 1:1 binding stoichiometry for the HSA-rutin complex was determined. The efficient quenching of the Trp214 fluorescence by rutin, fluorescence resonance energy transfer from excited Trp214 to rutin, and competitive binding of warfarin indicate that the binding site for the flavonoid is situated within subdomain IIA of HSA. The presence of the sugar moiety in the flavonoid molecule reduces affinity of rutin for binding to HSA but does not affect the binding stoichiometry and location of the binding site compared with aglycone analogues.

  1. The human sunburn reaction: histologic and biochemical studies

    SciTech Connect

    Gilchrest, B.A.; Soter, N.A.; Stoff, J.S.; Mihm, M.C. Jr.

    1981-01-01

    The ultraviolet-induced erythema reaction was investigated histologically and biochemically in four subjects, utilizing suction blister aspirates, analyzed for histamine and prostaglandin E2 (PGE2), and Epon-embedded 1-mu skin biopsy sections from control skin and from irradiated skin at intervals for 72 hours after exposure to a Hanovia lamp. Major histologic alterations in the epidermis included dyskeratotic and vacuolated keratinocytes (sunburn cells), and disappearance of Langerhans cells. In the dermis the major changes were vascular, involving both the superficial and deep venular plexuses. Endothelial cell enlargement was first apparent within 30 minutes of irradiation, peaked at 24 hours, and persisted throughout the 72-hour study period. Mast cell degranulation and associated perivenular edema were first apparent at 1 hour and striking at the onset of erythema, 3 to 4 hours postirradiation; edema was absent and mast cells were again normal in number and granule content at 24 hours. Histamine levels rose approximately fourfold above control values immediately after the onset of erythema and returned to baseline within 24 hours. PGE2 levels were statistically elevated even before the onset of erythema and reached approximately 150% of the control value at 24 hours. These data provide the first evidence that histamine may mediate the early phase of the human sunburn reaction and increase our understanding of its complex histologic and biochemical sequelae.

  2. Protein variations associated with in vitro aging of human fibroblasts and quantitative limits on the error catastrophe hypothesis.

    PubMed

    Van Keuren, M L; Merril, C R; Goldman, D

    1983-11-01

    Two-dimensional electrophoresis was used to examine protein alterations associated with in vitro cellular aging. Patterns of cellular proteins from early and late passage human fibroblasts of two strains (normal and trisomy 21) were analyzed in silver-stained gels and autoradiograms with computerized microdensitometry. Four proteins were significantly altered in density in both cell strains. In late passage cells, these proteins were from 6 to 66% the density in early passage cells. The error catastrophe hypothesis predicts that random amino acid substitutions accumulate with cellular aging. No new proteins or satellite spots due to such substitutions, however, were detected in late passage cells. An upper bound of 2.5% was set by high resolution densitometry for the fraction of abnormal protein that could be present but undetected by these methods. PMID:6226730

  3. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters.

    PubMed

    Riedel, Timothy E; Zimmer-Faust, Amity G; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T; Ebentier, Darcy L; Byappanahalli, Muruleedhara; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B; Griffith, John F; Holden, Patricia A; Shanks, Orin C; Weisberg, Stephen B; Jay, Jennifer A

    2014-04-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample. PMID:24583609

  4. Ascertainment bias in studies of human genome-wide polymorphism

    PubMed Central

    Clark, Andrew G.; Hubisz, Melissa J.; Bustamante, Carlos D.; Williamson, Scott H.; Nielsen, Rasmus

    2005-01-01

    Large-scale SNP genotyping studies rely on an initial assessment of nucleotide variation to identify sites in the DNA sequence that harbor variation among individuals. This “SNP discovery” sample may be quite variable in size and composition, and it has been well established that properties of the SNPs that are found are influenced by the discovery sampling effort. The International HapMap project relied on nearly any piece of information available to identify SNPs—including BAC end sequences, shotgun reads, and differences between public and private sequences—and even made use of chimpanzee data to confirm human sequence differences. In addition, the ascertainment criteria shifted from using only SNPs that had been validated in population samples, to double-hit SNPs, to finally accepting SNPs that were singletons in small discovery samples. In contrast, Perlegen's primary discovery was a resequencing-by-hybridization effort using the 24 people of diverse origin in the Polymorphism Discovery Resource. Here we take these two data sets and contrast two basic summary statistics, heterozygosity and FST, as well as the site frequency spectra, for 500-kb windows spanning the genome. The magnitude of disparity between these samples in these measures of variability indicates that population genetic analysis on the raw genotype data is ill advised. Given the knowledge of the discovery samples, we perform an ascertainment correction and show how the post-correction data are more consistent across these studies. However, discrepancies persist, suggesting that the heterogeneity in the SNP discovery process of the HapMap project resulted in a data set resistant to complete ascertainment correction. Ascertainment bias will likely erode the power of tests of association between SNPs and complex disorders, but the effect will likely be small, and perhaps more importantly, it is unlikely that the bias will introduce false-positive inferences. PMID:16251459

  5. The Complexity of Human Walking: A Knee Osteoarthritis Study

    PubMed Central

    Kotti, Margarita; Duffell, Lynsey D.; Faisal, Aldo A.; McGregor, Alison H.

    2014-01-01

    This study proposes a framework for deconstructing complex walking patterns to create a simple principal component space before checking whether the projection to this space is suitable for identifying changes from the normality. We focus on knee osteoarthritis, the most common knee joint disease and the second leading cause of disability. Knee osteoarthritis affects over 250 million people worldwide. The motivation for projecting the highly dimensional movements to a lower dimensional and simpler space is our belief that motor behaviour can be understood by identifying a simplicity via projection to a low principal component space, which may reflect upon the underlying mechanism. To study this, we recruited 180 subjects, 47 of which reported that they had knee osteoarthritis. They were asked to walk several times along a walkway equipped with two force plates that capture their ground reaction forces along 3 axes, namely vertical, anterior-posterior, and medio-lateral, at 1000 Hz. Data when the subject does not clearly strike the force plate were excluded, leaving 1–3 gait cycles per subject. To examine the complexity of human walking, we applied dimensionality reduction via Probabilistic Principal Component Analysis. The first principal component explains 34% of the variance in the data, whereas over 80% of the variance is explained by 8 principal components or more. This proves the complexity of the underlying structure of the ground reaction forces. To examine if our musculoskeletal system generates movements that are distinguishable between normal and pathological subjects in a low dimensional principal component space, we applied a Bayes classifier. For the tested cross-validated, subject-independent experimental protocol, the classification accuracy equals 82.62%. Also, a novel complexity measure is proposed, which can be used as an objective index to facilitate clinical decision making. This measure proves that knee osteoarthritis subjects exhibit more variability in the two-dimensional principal component space. PMID:25232949

  6. Improving the Limit on the Electron EDM: Data Acquisition and Systematics Studies in the ACME Experiment

    NASA Astrophysics Data System (ADS)

    Hess, Paul William

    The ACME collaboration has completed a measurement setting a new upper limit on the size of the electron's permanent electric dipole moment (EDM). The existence of the EDM is well motivated by theories extending the standard model of particle physics, with predicted sizes very close to the current experimental limit. The new limit was set by measuring spin precession within the metastable H state of the polar molecule thorium monoxide (ThO). A particular focus here is on the automated data acquisition system developed to search for a precession phase odd under internal and external reversal of the electric field. Automated switching of many different experimental controls allowed a rapid diagnosis of major systematics, including the dominant systematic caused by non-reversing electric fields and laser polarization gradients. Polarimetry measurements made it possible to quantify and minimize the polarization gradients in our state preparation and probe lasers. Three separate measurements were used to determine the electric field that did not reverse when we tried to switch the field direction. The new bound of | de| < 8.7 x 10--29 e·cm is over an order of magnitude smaller than previous limits, and strongly limits T-violating physics at TeV energy scales.

  7. Comparative drug release measurements in limited amounts of liquid: a suppository formulation study.

    PubMed

    Welch, Ken; Ek, Ragnar; Strømme, Maria

    2006-07-01

    A novel method for the investigation of drug formulations in limited liquid volumes is presented. The experimental setup consists of a measurement cell containing an absorbent sponge cloth placed between two parallel electrodes. Conductivity measurements are used to monitor the drug release from the dosage form. By varying the amount of water contained in the absorbent cloth surrounding the dosage form, it is possible to measure the drug release performance of the dosage form in very limited amounts of water. The method was employed to test four different tablet formulations consisting of the model drug NaCl incorporated in excipient matrices of hard fat, polyethylene glycol, microcrystalline cellulose and a mixture of microcrystalline cellulose and croscarmellose sodium (Ac-Di-Sol). The drug release rates of the different formulations in limited water volumes differed markedly from the release rates in an excess of water. Whereas the release rates from all tablet types in an excess of water showed only minor differences among the tablet types, the release rates from the tablets formulated with disintegrating excipients were clearly superior in limited water volumes. The developed method for drug release in limited volumes of liquid should be suitable for evaluation of rectal dosage forms. PMID:16848731

  8. Are Liberal Studies Teachers Ready to Prepare Human Rights Respecting Students? A Portrait of Teachers' Attitudes towards Human Rights

    ERIC Educational Resources Information Center

    Leung, Yan Wing; Lo, Yan Lam

    2012-01-01

    As in most countries, human rights education (HRE) in Hong Kong has never been high on the educational agenda. In 2009, a compulsory subject, Liberal Studies (LS), which could be used as a platform for HRE, was introduced. The Hong Kong Institute of Education launched a research and development project which, as one of its objectives, studied LS…

  9. FACULTY OF ARTS AND HUMANITIES CHAIR, DEPARTMENT OF WOMEN'S STUDIES AND FEMINIST RESEARCH

    E-print Network

    Sinnamon, Gordon J.

    FACULTY OF ARTS AND HUMANITIES CHAIR, DEPARTMENT OF WOMEN'S STUDIES AND FEMINIST RESEARCH Nominations and applications are invited for the position of Chair of the Department of Women's Studies of Women's Studies and Feminist Research Faculty of Arts and Humanities University College, Room 112

  10. The Women's Studies Program and the Human Rights Institute present a film screening and panel discussion

    E-print Network

    Alpay, S. Pamir

    The Women's Studies Program and the Human Rights Institute present a film screening and panel, Department of Gender and Women's Studies, University of Arizona), author of Entry Denied: Controlling is sponsored by: the Women's Studies Program, the Human Rights Institute, the Institute for Puerto Rican

  11. Roadmap: Human Development and Family Studies Case Management for Individuals and Families -Bachelor of Science

    E-print Network

    Sheridan, Scott

    Roadmap: Human Development and Family Studies ­ Case Management for Individuals and Families (upper division) 3 #12;Roadmap: Human Development and Family Studies ­ Case Management for Individuals Development and Family Studies: Case Management I 3-6 Offered in fall only; fulfills experiential learning

  12. A Study of Seventh-Graders Comprehensions of Human Reproduction Concepts

    ERIC Educational Resources Information Center

    Barrow, Lloyd Harley

    1977-01-01

    Study of an Iowa junior high school revealed that: (1) seventh grade pupils' knowledge levels were raised after studying human reproduction concepts and that (2) the pupils were of the opinion that human reproduction studies should be included in life science classes. (MB)

  13. A comparative study between human skin substitutes and normal human skin using Raman microspectroscopy.

    PubMed

    Leroy, Marie; Labbé, Jean-François; Ouellet, Marise; Jean, Jessica; Lefèvre, Thierry; Laroche, Gaétan; Auger, Michèle; Pouliot, Roxane

    2014-06-01

    Research in the field of bioengineered skin substitutes is motivated by the need to find new dressings for people affected by skin injuries (burns, diabetic ulcers), and to develop adequate skin models to test new formulations developed in vitro. Thanks to advances in tissue engineering, it is now possible to produce human skin substitutes without any exogenous material, using the self-assembly method developed by the Laboratoire d'Organogénèse Expérimentale. These human skin substitutes consist of a dermis and a stratified epidermis (stratum corneum and living epidermis). Raman microspectroscopy has been used to characterize and compare the molecular organization of skin substitutes with normal human skin. Our results confirm that the stratum corneum is a layer rich in lipids which are well ordered (trans conformers) in both substitutes and normal human skin. The amount of lipids decreases and more gauche conformers appear in the living epidermis in both cases. However, the results also show that there are fewer lipids in the substitutes and that the lipids are more organized in the normal human skin. Concerning the secondary structure of proteins and protein content, the data show that they are similar in the substitutes and in the normal human skin. In fact, the epidermis is rich in ?-keratin, whereas the dermis contains mainly type I collagen. PMID:24530562

  14. Prospective study of human herpesvirus 6, human herpesvirus 7, and cytomegalovirus infections in human immunodeficiency virus-positive patients.

    PubMed Central

    Fabio, G; Knight, S N; Kidd, I M; Noibi, S M; Johnson, M A; Emery, V C; Griffiths, P D; Clark, D A

    1997-01-01

    Blood samples from human immunodeficiency virus (HIV)-positive patients were monitored for cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and HHV-7 by PCR. We detected CMV in 17% of the patients, HHV-6 in 6%, and HHV-7 in 3%. The viral loads of CMV were significantly higher than those of HHV-6 (P = 0.007) or HHV-7 (P = 0.01). Detection of CMV and HHV-6 was associated with low and high CD4 counts, respectively. PMID:9316927

  15. Building Rapport between Human and ECA: A Pilot Study

    E-print Network

    Novick, David G.

    agent, familiarity, rapport, paralinguistic, nonverbal communication 1 Introduction An embodied rapport with their human partners. We focus on paralinguistic behaviors, and especially nonverbal behaviors, and their role in communicating rapport. Using an ECA that guides its players through a speech

  16. Studying Gestures: The Iconic Roots of Human Communication Systems 

    E-print Network

    Ioannou, Charis

    2011-11-23

    This paper tests the hypothesis that the iconicity inherent in human gestures can be a key element in the creation and evolution of communication systems. An interactive experiment based on playing charades was conducted modelling a situation where...

  17. Drug eluting stents: are human and animal studies comparable?

    PubMed Central

    Virmani, R; Kolodgie, F D; Farb, A; Lafont, A

    2003-01-01

    Animal models of stenting probably predict human responses as the stages of healing are remarkably similar. What is characteristically different is the temporal response to healing, which is substantially prolonged in humans. The prevention of restenosis in recent clinical trials of drug eluting stents may represent a near absent or incomplete phase of intimal healing. Continued long term follow up of patients with drug eluting stents for major adverse cardiac events and angiographic restenosis is therefore imperative. PMID:12527658

  18. The intracellular sensor NOD2 induces microRNA-29 expression in human dendritic cells to limit IL-23 release.

    PubMed

    Brain, Oliver; Owens, Benjamin M J; Pichulik, Tica; Allan, Philip; Khatamzas, Elham; Leslie, Alasdair; Steevels, Tessa; Sharma, Sameer; Mayer, Alice; Catuneanu, Ana Maria; Morton, Victoria; Sun, Mei-Yi; Jewell, Derek; Coccia, Margherita; Harrison, Oliver; Maloy, Kevin; Schönefeldt, Susann; Bornschein, Simon; Liston, Adrian; Simmons, Alison

    2013-09-19

    NOD2 is an intracellular sensor that contributes to immune defense and inflammation. Here we investigated whether NOD2 mediates its effects through control of microRNAs (miRNAs). miR-29 expression was upregulated in human dendritic cells (DCs) in response to NOD2 signals, and miR-29 regulated the expression of multiple immune mediators. In particular, miR-29 downregulated interleukin-23 (IL-23) by targeting IL-12p40 directly and IL-23p19 indirectly, likely via reduction of ATF2. DSS-induced colitis was worse in miR-29-deficient mice and was associated with elevated IL-23 and T helper 17 signature cytokines in the intestinal mucosa. Crohn's disease (CD) patient DCs expressing NOD2 polymorphisms failed to induce miR-29 upon pattern recognition receptor stimulation and showed enhanced release of IL-12p40 on exposure to adherent invasive E. coli. Therefore, we suggest that loss of miR-29-mediated immunoregulation in CD DCs might contribute to elevated IL-23 in this disease. PMID:24054330

  19. Growth as affected by general hormonal factors and hormonal balances, and the limitations of such studies

    E-print Network

    Paris-Sud XI, Université de

    Growth as affected by general hormonal factors and hormonal balances, and the limitations France. Summary. Many elements are implicated in fetal and postnatal growth ; the hormonal factors are discussed in this review. In the first section, general hormonal effects on the growth of domestic animals

  20. A case study: Residue reduction at Deer Park Refining Limited Partnership

    Microsoft Academic Search

    Geehan

    1996-01-01

    With input from Shell Synthetic Fuels Inc. (SSFI), Deer Park Refining Limited Partnership (DPRLP) analyzed options for managing the bottom of the barrel to extinction, with an objective of high return on investment. DPRLP is a joint venture of PEMEX and Shell Oil Company. This Gulf Coast refiner processes 227M BBL\\/D of heavy, high sulfur crude. This paper discusses the

  1. A Case Study of the Role of Collective Bargaining in Corporate Change - Qantas Airways Limited1

    Microsoft Academic Search

    Jim McDonald; Bruce Millett

    Against a background in the past decade of significant contextual changes, including the deregulation of the airlines, the privatisation of Qantas, and the merger of Australian Airlines, Qantas Airlines Limited has undergone significant organisational change. This change has not been characterised by a linear progression but by fluctuations between traditional organisational structures focussed around industrial relations and HR functions and

  2. A cruciform shape to study the influence of strain paths on forming limit curves

    E-print Network

    Paris-Sud XI, Université de

    , especially for aluminum alloys which exhibit generally a low formability compared with typical mild steels, understanding and characterizing the formability of metal sheets are essential for controlling final product the formability of sheet metals is the forming limit diagram (FLD). A FLD is a strain diagram built with the in

  3. "Bark parks"--a study on interdog aggression in a limited-control environment.

    PubMed

    Shyan, Melissa R; Fortune, Kristina A; King, Christine

    2003-01-01

    As limited-control dog parks become more popular, concerns arise about whether these parks encourage interdog aggression. Systematic observations made at 1 park over 72 hr across 8 months found that 28 conflicts or potential conflicts occurred (< 0.5%). Of these, 14 were clear aggressive episodes. Each lasted less than 1 min (< 0.33% of total observation time). There were 14 other incidents of possible aggression that were ambiguous in nature. Each lasted less than 30 sec (< 0.17%). None of these incidents led to serious injury. Of the 177 dogs observed, only 9 were aggressive toward other dogs (5%): 6 aggressors, once each; 2 aggressors, twice each; 1 aggressor, 3 times. Results indicate that aggression in limited-control dog parks may be relatively rare and probably presents only a limited risk to dogs and their caregivers (owners). In part, this may be because owners who frequent dog parks are self-selecting, self-monitoring, and self-limiting in regard to dog aggression. PMID:12795856

  4. Limited energy study, Energy Engineering Analysis Program (EEAP), Rock Island Arsenal. Final report

    SciTech Connect

    NONE

    1993-11-05

    The purpose of this limited energy survey is to evaluate Energy Conservation Opportunities (ECOs) at three locations at Rock Island Arsenal. The three ECOs evaluated are: (1) Lighting efficiency improvements in Building 220. (2) Lighting efficiency improvements in Building 350. (3) Cogeneration/Peak-Shaving Installation at Buildings 160 and 168.

  5. High-Stakes Testing, High School Graduation, and Limited English Proficient Students: A Case Study

    ERIC Educational Resources Information Center

    Giambo, Debra A.

    2010-01-01

    The educational accountability systems of both the No Child Left Behind (NCLB) Act of 2001 and the state of Florida (as of 1999) were modeled after Texas' system, despite its flaws. NCLB reaches for all students to achieve academic proficiency and designates students with limited English proficiency (LEP) as an important subgroup. As we work with…

  6. Experimental and analytical studies for forming limit of AZ31 alloy on warm sheet metal forming

    Microsoft Academic Search

    Y. S. Lee; M. C. Kim; S. W. Kim; Y. N. Kwon; S. W. Choi; J. H. Lee

    2007-01-01

    Since magnesium alloy sheet usually exhibits poor press formability, the sheet forming for complex shaped part has many difficult problems. Among these problems, the die design to prevent some defects is one of the important process variables. Therefore, the data for forming limit of AZ31 sheet is necessary to prevent the defect and get the good formed part. In this

  7. High-Performance Liquid Chromatographic Determination of Rivastigmine in Human Plasma for Application in Pharmacokinetic Studies

    PubMed Central

    Amini, Hossein; Ahmadiani, Abolhassan

    2010-01-01

    A simple and reproducible HPLC method with spectrophotometric detection was developed for determination of rivastigmine in human plasma. Liquid-liquid extraction of rivastigmine and donepezil (as internal standard) from plasma samples was performed with 1-butanol/n-hexane (2:98 v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a Silica column (250 mm × 4.6 mm, 5 ?m) under isocratic elution with acetonitrile-50 mM aqueous sodium dihydrogen phosphate (17: 83 v/v, pH 3.1. Analyses were run at a flow-rate of 1.3 mL/min at of 50°C. The recovery was 90.8% and 95.7% for rivastigmine and the internal standard donepezil, respectively. The precision of the method was 2.6% to 9.1% over the concentration range of 0.5-16 ng/mL for rivastigmine in plasma with a linearity greater than 0.999. The method was specific and sensitive, with a quantification limit of 0.5 ng/mL and a detection limit of 0.2 ng/mL in plasma. The method was used for a bioequivalence study in healthy subjects. PMID:24363716

  8. Vascular targets for cannabinoids: animal and human studies

    PubMed Central

    Stanley, Christopher; O'Sullivan, Saoirse E

    2014-01-01

    Application of cannabinoids and endocannabinoids to perfused vascular beds or individual isolated arteries results in changes in vascular resistance. In most cases, the result is vasorelaxation, although vasoconstrictor responses are also observed. Cannabinoids also modulate the actions of vasoactive compounds including acetylcholine, methoxamine, angiotensin II and U46619 (thromboxane mimetic). Numerous mechanisms of action have been proposed including receptor activation, potassium channel activation, calcium channel inhibition and the production of vasoactive mediators such as calcitonin gene-related peptide, prostanoids, NO, endothelial-derived hyperpolarizing factor and hydrogen peroxide. The purpose of this review is to examine the evidence for the range of receptors now known to be activated by cannabinoids. Direct activation by cannabinoids of CB1, CBe, TRPV1 (and potentially other TRP channels) and PPARs in the vasculature has been observed. A potential role for CB2, GPR55 and 5-HT1A has also been identified in some studies. Indirectly, activation of prostanoid receptors (TP, IP, EP1 and EP4) and the CGRP receptor is involved in the vascular responses to cannabinoids. The majority of this evidence has been obtained through animal research, but recent work has confirmed some of these targets in human arteries. Vascular responses to cannabinoids are enhanced in hypertension and cirrhosis, but are reduced in obesity and diabetes, both due to changes in the target sites of action. Much further work is required to establish the extent of vascular actions of cannabinoids and the application of this research in physiological and pathophysiological situations. Linked ArticlesThis article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-6 PMID:24329566

  9. Morphometric study of human myocardium in acquired valvular diseases.

    PubMed

    Jantunen, E; Halinen, M O; Romppanen, T; Kosma, V M; Collan, Y

    1989-12-01

    To study the effect of various valvular heart diseases on the quantitative histology of myocardium, 38 human hearts with valvular lesions were examined (11 aortic stenoses, nine mitral stenoses, nine mitral incompetence and nine combined aortic and mitral valve lesions). The control group consisted of ten hearts without any valvular lesions. With morphometrical methods the volume fractions of myocardial components (myocardial fibres, interstitial space and diffuse connective tissue), the numerical density of arterioles and the mean fibre diameter were estimated. Myocardial fibrosis was more severe in hearts with valvular lesions than in the controls (5.4% vs 3.3%, P less than 0.01), but did not correlate with the anatomical severity of the valvular lesions. The most severe myocardial fibrosis was found in hearts with mitral incompetence (6.7%). Fibre hypertrophy was most severe in hearts with aortic stenosis and in hearts with mitral incompetence (22 microns and 23 microns, respectively). In hearts with severe valvular lesions the mean fibre diameter was 23 microns and in hearts with mild to moderate lesions 19 microns (P less than 0.01). Good correlation was observed between the mean fibre diameter and the weight of the left ventricle (r = 0.81, P less than 0.01). The volume fractions of connective tissue and interstitial space were significantly higher and the volume fraction of myocardial fibres was correspondingly lower in the subendocardium than in the subepicardium in hearts with either pressure overload (aortic stenosis) or volume overload (mitral incompetence). In conclusion, myocardial fibrosis occurs in patients with various valvular lesions, but the severity of the fibrosis does not correlate with the anatomical severity of valvular lesions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2532531

  10. Experimental study of Human Adenoviruses interactions with clays

    NASA Astrophysics Data System (ADS)

    Bellou, Maria; Syngouna, Vasiliki; Paparrodopoulos, Spyros; Vantarakis, Apostolos; Chrysikopoulos, Constantinos

    2014-05-01

    Clays are used to establish low permeability liners in landfills, sewage lagoons, water retention ponds, golf course ponds, and hazardous waste sites. Human adenoviruses (HAdVs) are waterborne viruses which have been used as viral indicators of fecal pollution. The objective of this study was to investigate the survival of HAdV in static and dynamic clay systems. The clays used as a model were crystalline aluminosilicates: kaolinite and bentonite. The adsorption and survival of HAdVs onto these clays were characterized at two different controlled temperatures (4 and 25o C) under static and dynamic batch conditions. Control tubes, in the absence of clay, were used to monitor virus inactivation due to factors other than adsorption to clays (e.g. inactivation or sorption onto the tubes walls). For both static and dynamic batch experiments, samples were collected for a maximum period of seven days. This seven day time - period was determined to be sufficient for the virus-clay systems to reach equilibrium. To infer the presence of infectious HAdV particles, all samples were treated with Dnase and the extraction of viral nucleid acid was performed using a commercial viral RNA kit. All samples were analyzed by Real - Time PCR which was used to quantify viral particles in clays. Samples were also tested for virus infectivity by A549 cell cultures. Exposure time intervals in the range of seven days (0.50-144 hours) resulted in a load reduction of 0.74 to 2.96 logs for kaolinite and a reduction of 0.89 to 2.92 for bentonite. Furthermore, virus survival was higher onto bentonite than kaolinite (p

  11. Age and decisions to limit life support for patients with acute lung injury: a prospective cohort study

    PubMed Central

    2014-01-01

    Introduction The proportion of elderly Americans admitted to the intensive care unit (ICU) in the last month of life is rising. Hence, challenging decisions regarding the appropriate use of life support are increasingly common. The objective of this study was to estimate the association between patient age and the rate of new limitations in the use of life support, independent of daily organ dysfunction status, following acute lung injury (ALI) onset. Methods This was a prospective cohort study of 490 consecutive patients without any limitations in life support at the onset of ALI. Patients were recruited from 11 ICUs at three teaching hospitals in Baltimore, Maryland, USA, and monitored for the incidence of six pre-defined limitations in life support, with adjustment for baseline comorbidity and functional status, duration of hospitalization before ALI onset, ICU severity of illness, and daily ICU organ dysfunction score. Results The median patient age was 52 (range: 18 to 96), with 192 (39%) having a new limitation in life support in the ICU. Of patients with a new limitation, 113 (59%) had life support withdrawn and died, 53 (28%) died without resuscitation, and 26 (14%) survived to ICU discharge. Each ten-year increase in patient age was independently associated with a 24% increase in the rate of limitations in life support (Relative Hazard 1.24; 95% CI 1.11 to 1.40) after adjusting for daily ICU organ dysfunction score and all other covariates. Conclusions Older critically ill patients are more likely to have new limitations in life support independent of their baseline status, ICU-related severity of illness, and daily organ dysfunction status. Future studies are required to determine whether this association is a result of differences in patient preferences by age, or differences in the treatment options discussed with the families of older versus younger patients. PMID:24886945

  12. Human Keratinocytes That Express hTERT and Also Bypass a p16INK4a-Enforced Mechanism That Limits Life Span Become Immortal yet Retain Normal Growth and Differentiation Characteristics

    Microsoft Academic Search

    MARK A. DICKSON; WILLIAM C. HAHN; YASUSHI INO; VINCENT RONFARD; JENNY Y. WU; ROBERT A. WEINBERG; DAVID N. LOUIS; FREDERICK P. LI; JAMES G. RHEINWALD

    2000-01-01

    Normal human cells exhibit a limited replicative life span in culture, eventually arresting growth by a process termed senescence. Progressive telomere shortening appears to trigger senescence in normal human fibroblasts and retinal pigment epithelial cells, as ectopic expression of the telomerase catalytic subunit, hTERT, immortalizes these cell types directly. Telomerase expression alone is insufficient to enable certain other cell types

  13. HUMEX, a study on the survivability and adaptation of humans to long-duration exploratory missions, part I: lunar missions

    NASA Technical Reports Server (NTRS)

    Horneck, G.; Facius, R.; Reichert, M.; Rettberg, P.; Seboldt, W.; Manzey, D.; Comet, B.; Maillet, A.; Preiss, H.; Schauer, L.; Dussap, C. G.; Poughon, L.; Belyavin, A.; Reitz, G.; Baumstark-Khan, C.; Gerzer, R.

    2003-01-01

    The European Space Agency has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis has been laid on human health and performance care as well as advanced life support developments including bioregenerative life support systems and environmental monitoring. The overall study goals were as follows: (i) to define reference scenarios for a European participation in human exploration and to estimate their influence on the life sciences and life support requirements; (ii) for selected mission scenarios, to critically assess the limiting factors for human health, wellbeing, and performance and to recommend relevant countermeasures; (iii) for selected mission scenarios, to critically assess the potential of advanced life support developments and to propose a European strategy including terrestrial applications; (iv) to critically assess the feasibility of existing facilities and technologies on ground and in space as testbeds in preparation for human exploratory missions and to develop a test plan for ground and space campaigns; (v) to develop a roadmap for a future European strategy towards human exploratory missions, including preparatory activities and terrestrial applications and benefits. This paper covers the part of the HUMEX study dealing with lunar missions. A lunar base at the south pole where long-time sunlight and potential water ice deposits could be assumed was selected as the Moon reference scenario. The impact on human health, performance and well being has been investigated from the view point of the effects of microgravity (during space travel), reduced gravity (on the Moon) and abrupt gravity changes (during launch and landing), of the effects of cosmic radiation including solar particle events, of psychological issues as well as general health care. Countermeasures as well as necessary research using ground-based test beds and/or the International Space Station have been defined. Likewise advanced life support systems with a high degree of autonomy and regenerative capacity and synergy effects were considered where bioregenerative life support systems and biodiagnostic systems become essential. Finally, a European strategy leading to a potential European participation in future human exploratory missions has been recommended. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  14. Socioeconomic factors from midlife predict mobility limitation and depressed mood three decades later; Findings from the AGES-Reykjavik Study

    PubMed Central

    2013-01-01

    Background Taking into account our rapidly ageing population, older people are of particular interest in studying health inequalities. Most studies of older persons only include measures of current socioeconomic status (SES) and do not take into account data from earlier stages of life. In addition, only classic SES measures are used, while alternative measures, such as car ownership and house ownership, might equally well predict health. The present study aims to examine the effect of midlife socioeconomic factors on mobility limitation and depressed mood three decades later. Methods Data were from 4,809 men and women aged 33–65 years who participated in the Reykjavik Study (1967–1992) and who were re-examined in old age in the Age, Gene/Environment Susceptibility (AGES) -Reykjavik Study (2002–2006). Results Education and occupation predicted mobility limitation and depressed mood. Independently, home and car ownership and the availability of housing features predicted mobility limitation. Shortages of food in childhood and lack of a car in midlife predicted depressed mood. Conclusion Socioeconomic factors from midlife and from childhood affect mobility limitation and depressed mood in old age. Prevention of health problems in old age should begin as early as midlife. PMID:23379351

  15. Limited effect of recombinant human mannose-binding lectin on the infection of novel influenza A (H7N9) virus in vitro.

    PubMed

    Guo, Jinlei; Cao, Yang; Qin, Kun; Zhao, Xiaopeng; Wang, Donghong; Li, Zi; Xin, Li; Shu, Yuelong; Zhou, Jianfang

    2015-02-27

    Mannose-binding lectin (MBL), a pattern-recognition molecule in serum, recognizes specific hexose sugars rich in mannose and N-acetylglucosamine on bacterium, yeasts, viruses as well as apoptotic cells. It has been well-identified that MBL has antiviral effects via binding to seasonal influenza H1 and H3 subtype viruses. Influenza A (H7N9) virus, a novel reassortant virus to human population, possesses the surface hemagglutinin (HA) and neuraminidase (NA) genes from duck and wild-bird influenza viruses and internal genes from poultry H9N2 viruses. As of Dec 7th, 2014, a total of 467 human infections and 183 fatal cases have been identified. Here, recombinant human (rh) MBL was tested for its binding and effects on hemagglutination inhibition (HI) and NA activity inhibition (NAI) of avian H7N9, H9N2 and human H3N2 viruses. We discovered that rhMBL exhibited a strong binding to H7N9 virus as human H3N2 did at high virus titers. However, it performed a significantly weaker HI activity effect on H7N9 comparing to those of H3N2 and H9N2, even at a much higher concentration (3.67 ± 0.33 vs. 0.026 ± 0.001 and 0.083 ± 0.02 ?g/mL, respectively). Similarly, minor NAI effect of rhMBL, even at up to 10 ?g/mL, was found on H7N9 virus while it displayed significant effects on both H3N2 and H9N2 at a lowest concentration of 0.0807 ± 0.009 and 0.0625 ?g/mL, respectively. The HI and NAI effects of rhMBL were calcium-dependent and mediated by lectin domain. Our findings suggest that MBL, the host innate molecule, has differential interference effects with human and avian influenza virus and limited antiviral effect against H7N9 virus. PMID:25634695

  16. Study of anticipated impact on DOE programs from proposed reductions to the external occupational radiation exposure limit

    SciTech Connect

    Clusen, Ruth C.

    1981-02-01

    A study of the impact of reducing the occupational radiation exposure limit from 5 rem/yr to 2.5, 1.0 and 0.5 rem/yr, respectively produced the following conclusions: reduction of the occupational exposure limit would result in significant increase in total accumulated exposure to the current radiation worker population and could require an increase in the work force; important programs would have to be abandoned at a planned exposure limit of 0.5 rem/yr; some engineering technology is not sufficiently developed to design or operate at the 0.5 rem/yr limit; even a factor of 2 reduction (2.5 rem/yr) would significantly increase costs and would result in an increase in total exposure to the work force; in addition to a significant one-time initial capital cost resulting from a 0.5 rem/yr limit, there would be a significant increase in annual costs; the major emphasis in controlling occupational exposure should be on further reduction of total man-rem; and current standards are used only as a limit. For example, 97% of the employees receive less than 0.5 rem/yr.

  17. Reynolds number limits for jet propulsion: A numerical study of simplified jellyfish

    E-print Network

    Herschlag, Gregory

    2010-01-01

    The Scallop Theorem states that reciprocal methods of locomotion, such as jet propulsion or paddling, will not work in Stokes flow (Reynolds number = 0). In nature the effective limit of jet propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use jet propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. The limitations of jet propulsion at intermediate Re is explored here using the immersed boundary method to solve the two-dimensional Navier Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using jet propulsion. Average forward veloc...

  18. Limits on charge nonconservation studied by nuclear excitation of sup 127 I

    SciTech Connect

    Ejiri, H.; Kawasaki, M.; Kinoshita, H.; Ohsumi, H.; Okada, K.; Sano, H. (Department of Physics, Osaka University, Toyonaka, Osaka 560, Japan (JP)); Takasugi, E. (Department of Physics, College of General Education, Osaka University, Toyonaka, Osaka 560, (Japan))

    1991-07-01

    Lower limits on the mean lives of the charge-nonconserving (CNC) processes, {sup 127}I+{ital e}{sub {ital K}}{r arrow}{sup 127}I{sup *}+{nu}, leading to the first (second) excited state of {sup 127}I, were obtained as {tau}{gt}0.58(0.56){times}10{sup 23} yr by searching for the {gamma} decay from the first (second) excited state of {sup 127}I. Upper limits on the ratios of the CNC strengths to the charge-conserving ones through the weak boson and photon mediating processes are obtained as {epsilon}{sub {ital W}}{sup 2}{lt}11{times}10{sup {minus}25} and {epsilon}{sub {gamma}}{sup 2}{lt}4.8{times}10{sup {minus}40}.

  19. Contribution of Human Fc?Rs to Disease with Evidence from Human Polymorphisms and Transgenic Animal Studies

    PubMed Central

    Gillis, Caitlin; Gouel-Chéron, Aurélie; Jönsson, Friederike; Bruhns, Pierre

    2014-01-01

    The biological activities of human IgG antibodies predominantly rely on a family of receptors for the Fc portion of IgG, Fc?Rs: Fc?RI, Fc?RIIA, Fc?RIIB, Fc?RIIC, Fc?RIIIA, Fc?RIIIB, FcRL5, FcRn, and TRIM21. All Fc?Rs bind IgG at the cell surface, except FcRn and TRIM21 that bind IgG once internalized. The affinity of Fc?Rs for IgG is determined by polymorphisms of human Fc?Rs and ranges from 2?×?104 to 8?×?107?M?1. The biological functions of Fc?Rs extend from cellular activation or inhibition, IgG-internalization/endocytosis/phagocytosis to IgG transport and recycling. This review focuses on human Fc?Rs and intends to present an overview of the current understanding of how these receptors may contribute to various pathologies. It will define Fc?Rs and their polymorphic variants, their affinity for human IgG subclasses, and review the associations found between Fc?R polymorphisms and human pathologies. It will also describe the human Fc?R-transgenic mice that have been used to study the role of these receptors in autoimmune, inflammatory, and allergic disease models. PMID:24910634

  20. Environmental Impact of Mining and Ore Processing – A Case Study at Satellite Goldfields Limited

    Microsoft Academic Search

    Albert O. Ainoo; Newton Amegbey; Raymond S. Suglo

    \\u000a The increasing number of surface mines in Ghana and the consequent adverse effects of mining operations on the environment\\u000a have been of great concern to the local communities, government and non-governmental organisations in Ghana over the last\\u000a decade. Satellite Goldfields Limited (SGL) is an open pit gold mine in the Mporhor Wassa East District which produces about\\u000a 10,000 tpd of

  1. Taking natural limits seriously: implications for development studies and the environment

    E-print Network

    Vira, Bhaskar

    2015-06-09

    as being primarily about the protection of rare and endangered species, or concerned with long time horizons that are beyond the cognitive gaze of those who are dealing with the material deprivations and exclusions of the present. Underpinning such views... labour power and nature, and reshapes these in its own image — suggests that it is inherently incompatible with natural limits. As a system, capitalism needs to continually expand in its search for profit, and this relies on sourcing ever-cheaper raw...

  2. Computational Study of the Ultimate Scaling Limits of CNT Tunneling Devices

    Microsoft Academic Search

    Stefano Poli; Susanna Reggiani; Antonio Gnudi; Elena Gnani; Giorgio Baccarani

    2008-01-01

    The ultimate scaling limits of p-i-n carbon-nanotube field-effect transistors (CNT-FETs) are investigated through numerical simulations based on a quantum-mechanical transport within the nonequilibrium Green's function formalism, based on an energy-dependent effective mass, including inelastic phonon scattering. Starting from the projected specifications of the International Technology Roadmap for Semiconductors for the low-operating-power double-gate MOSFETs, the effect of variations of oxide thickness,

  3. Preparation of the Human Skull for Skull Base Anatomic Study

    PubMed Central

    Ator, Gregory A.; Andrews, James C.; Maxwell, David S.

    1993-01-01

    Human skulls are unsurpassed in the ability to provide three-dimensional instruction in osteology as well as understanding the sites of soft tissue insertion and the intricate course of neurovascular structures in the skull base. Recent geopolitical developments in Asia have led to extreme difficulty in obtaining human skull specimens. The purpose of this article is to present a method for the preparation of dried human skulls from fresh and frozen cadavers using commonly available chemicals. The technique, requiring about 8 weeks total time and basic equipment, consists of maceration accelerated by several enzymes followed by defatting, washing, and bleaching. The skulls produced are of excellent quality and durability with no preparation artifacts. An economical source of skulls has now been reestablished to facilitate learning of the intricate relationships of the skull base. ImagesFigure 1Figure 2 PMID:17170882

  4. Study of limiter damage in a magnetic-field error region of the ZT-40M experiment

    SciTech Connect

    Makowitz, H.

    1983-01-01

    A study has been initiated of material plasma interactions on the ZT-40M, Reversed Field Pinch (RFP) plasma physics confinement experiment at Los Alamos National Laboratory. Observations of the evaporation and cracking to TiC coatings, initially placed on an AXF-5Q Graphite mushroom limiter, installed in a high field error region (e.g. an experimental vacuum vessel/liner port) were investigated. A parametric study was performed of the thermal and stress behavior of the limiter and coating materials undergoing plasma material heat exchange processes, in order to infer the magnitude of heat flux necessary to explain the observed material damage. In addition the vacuum (liner) wall material behavior was studied parametrically using the same heat flux values as the limiter study. A one-dimensional conduction model was used with applied heat and radiation boundary conditions, for predicting temperature distributions in space and time, where the thermal stress was calculated using a restrained in bending only plate model. Wall loadings corresponding to first wall, limiter energy fluxes ranging between 1 x 10/sup 2/ W/cm/sup 2/ and 1 x 10/sup 5/ W/cm/sup 2/ were used as parameters with plasma material interaction times (tau/sub QO) between 0.5 ms and 10 ms. Short plasma energy deposition time (tau/sub QO/ > 10 ms) spacial and time histories of temperature and stress were calculated for SS-304, Inconel-625, TiC and AXF -5Q Graphite materials.

  5. Equity for Limited English Proficient Students Regarding Assessment and Effectiveness of Testing Accommodations: A Study of Third Graders

    ERIC Educational Resources Information Center

    Deysson, Sandra Lynn

    2013-01-01

    This study focused on the aspect of the No Child Left Behind Act (NCLB) and the Virginia Department of Education (VDOE) that require the inclusion of all limited English proficient (LEP) students in testing situations, simultaneously making an effort to close the achievement gap. NCLB indicates that each state is to assess students in a language…

  6. Humanized Thymidine Kinase-NOG Mice Can Be Used to Identify Drugs That Cause Animal-Specific Hepatotoxicity: A Case Study with Furosemide.

    PubMed

    Xu, Dan; Michie, Sara A; Zheng, Ming; Takeda, Saori; Wu, Manhong; Peltz, Gary

    2015-07-01

    Interspecies differences have limited the predictive utility of toxicology studies performed using animal species. A drug that could be a safe and effective treatment in humans could cause toxicity in animals, preventing it from being used in humans. We investigated whether the use of thymidine kinase (TK)-NOG mice with humanized livers could prevent this unfortunate outcome (i.e., "rescue" a drug for use in humans). A high dose of furosemide is known to cause severe liver toxicity in mice, but it is a safe and effective treatment in humans. We demonstrate that administration of a high dose of furosemide (200 mg/kg i.p.) causes extensive hepatotoxicity in control mice but not in humanized TK-NOG mice. This interspecies difference results from a higher rate of production of the toxicity-causing metabolite by mouse liver. Comparison of their survival curves indicated that the humanized mice were more resistant than control mice to the hepatotoxicity caused by high doses of furosemide. In this test case, humanized TK-NOG mouse studies indicate that humans could be safely treated with a high dose of furosemide. PMID:25962391

  7. Bioavailability of selenium from fish, yeast and selenate: a comparative study in humans using stable isotopes

    Microsoft Academic Search

    T. E. Fox; E G H M Van den Heuvel; C. A. Atherton; J R Dainty; D J Lewis; N J Langford; H M Crews; J B Luten; M Lorentzen; F W Sieling; P van Aken-Schneyder; M Hoek; M J J Kotterman; P van Dael; S J Fairweather-Tait

    2004-01-01

    Objective: To measure the bioavailability of selenium from cooked and raw fish in humans by estimating and comparing apparent absorption and retention of selenium in biosynthetically labelled fish with labelled selenate and biosynthetically labelled selenium in brewers yeast.Design: The intervention study was a parallel, randomised, reference substance controlled design carried out at two different centres in Europe.Setting: The human study

  8. A study of handwriting and its implications for cognitive considerations in human-computer interactions

    Microsoft Academic Search

    Karl U. Smith; Thomas J. Smith

    1991-01-01

    This study deals with the phenomenon of cognitive performance relative to handwriting behavior, and the human factors involved in the design of handwriting characters (letters, numbers, and words). Experimental methods of electronic motion analysis were used to study the human factors related to specialization of movements, writing tasks, and individual characteristics of handwriting activity. These three parameters of handwriting performance

  9. Extrapolation of Rodent Studies on Amniotic Fluid Contaminatnts to Human Populations

    Microsoft Academic Search

    Claude Hughes; Warren Foster; Siu Chan; Lawrence Platt; Stephanie Thompson; Slade Hubbard; Alison DuBose; Lee Tyrey

    2001-01-01

    If endocrine active chemicals (EACs) adversely affect human development, then there must be evidence of effects in animal models at properly scaled levels of exposure during pertinent sensitive periods as derived from quantified exposures of the human fetus. Our recent studies attempt to address both effects and exposures. First Study: Dams were gavaged from Gestation Day (GD) 14 through weaning

  10. Acute Effects of Cocaine in Lower Human Brain: An FMRI Study P. R. Kufahl1

    E-print Network

    Rowe, Daniel B.

    Acute Effects of Cocaine in Lower Human Brain: An FMRI Study P. R. Kufahl1 , Z. Li1 , R. Risinger1: This FMRI study used controlled doses of cocaine to induce BOLD signal changes in the human orbitofrontal cocaine-induced activation patterns across nine different subjects imaged at 1.5 Tesla. INTRODUCTION

  11. DEVELOPMENT OF A LOW-COST ROBOTIC MANIPULATOR AND ITS APPLICATION TO HUMAN MOTOR CONTROL STUDIES

    E-print Network

    Moussavi, Zahra M. K.

    capable, low-cost alternative to these systems through the use of geared DC servo motors. In orderDEVELOPMENT OF A LOW-COST ROBOTIC MANIPULATOR AND ITS APPLICATION TO HUMAN MOTOR CONTROL STUDIES C impedance controlled manipulator to study human motor learning. In particular, the focus was to develop

  12. Transcranial direct current stimulation: A computer-based human model study

    Microsoft Academic Search

    Tim Wagner; Felipe Fregni; Shirley Fecteau; Alan Grodzinsky; Markus Zahn; Alvaro Pascual-Leone

    2007-01-01

    ObjectivesInterest in transcranial direct current stimulation (tDCS) in clinical practice has been growing, however, the knowledge about its efficacy and mechanisms of action remains limited. This paper presents a realistic magnetic resonance imaging (MRI)-derived finite element model of currents applied to the human brain during tDCS.

  13. Establishment of a Reverse Genetics System for Studying Human Bocavirus in Human Airway Epithelia

    E-print Network

    Huang, Qinfeng; Deng, Xuefeng; Yan, Ziying; Cheng, Fang; Lou, Yong; Shen, Weiran; Lei-Butters, Diana C. M.; Chen, Aaron Yun; Li, Yi; Tang, Liang; Sö derlund-Venermo, Maria; Englehardt, John F.; Qiu, Jianming

    2012-08-30

    ) using viral DNA extracted from a nasopharyngeal aspirate of an infected patient, cloned the full-length HBoV1 genome, and demonstrated DNA replication, encapsidation of the ssDNA genome, and release of the HBoV1 virions from human embryonic kidney 293...

  14. Advantages and limitations of commercially available electrocuting grids for studying mosquito behaviour

    PubMed Central

    2013-01-01

    Background Mosquito feeding behaviour plays a major role in determining malaria transmission intensity and the impact of specific prevention measures. Human Landing Catch (HLC) is currently the only method that can directly and consistently measure the biting rates of anthropophagic mosquitoes, both indoors and outdoors. However, this method exposes the participant to mosquito-borne pathogens, therefore new exposure-free methods are needed to replace it. Methods Commercially available electrocuting grids (EGs) were evaluated as an alternative to HLC using a Latin Square experimental design in Dar es Salaam, Tanzania. Both HLC and EGs were used to estimate the proportion of human exposure to mosquitoes occurring indoors (?i), as well as its two underlying parameters: the proportion of mosquitoes caught indoors (Pi) and the proportion of mosquitoes caught between the first and last hour when most people are indoors (Pfl). Results HLC and EGs methods accounted for 69% and 31% of the total number of female mosquitoes caught respectively and both methods caught more mosquitoes outdoors than indoors. Results from the gold standard HLC suggest that An. gambiae s.s. in Dar es Salaam is neither exophagic nor endophagic (Pi???0.5), whereas An. arabiensis is exophagic (Pi??>?0.5). EGs yielded estimates of Pi for An. gambiae s.s., An. arabiensis and An. coustani, that were approximately equivalent to those with HLC but significantly underestimated Pfl for An. gambiae s.s. and An. coustani. The relative sampling sensitivity of EGs declined over the course of the night (p???0.001) for all mosquito taxa except An. arabiensis. Conclusions Commercial EGs sample human-seeking mosquitoes with high sensitivity both indoors and outdoors and accurately measure the propensity of Anopheles malaria vectors to bite indoors rather than outdoors. However, further modifications are needed to stabilize sampling sensitivity over a full nocturnal cycle so that they can be used to survey patterns of human exposure to mosquitoes. PMID:23497704

  15. Preclinical studies on the pharmacokinetics, safety, and toxicology of oxfendazole: toward first in human studies.

    PubMed

    Codd, Ellen E; Ng, Hanna H; McFarlane, Claire; Riccio, Edward S; Doppalapudi, Rupa; Mirsalis, Jon C; Horton, R John; Gonzalez, Armando E; Garcia, H Hugo; Gilman, Robert H

    2015-01-01

    A 2-week study in rats identified target organs of oxfendazole toxicity to be bone marrow, epididymis, liver, spleen, testis, and thymus. Female rats had greater oxfendazole exposure and exhibited toxicities at lower doses than did males. Decreased white blood cell levels, a class effect of benzimidazole anthelmintics, returned to normal during the recovery period. The no observed adverse effect level was determined to be >5 but <25 mg/kg/d and the maximum tolerated dose 100 mg/kg/d. The highest dose, 200 mg/kg/d, resulted in significant toxicity and mortality, leading to euthanization of the main study animals in this group after 7 days. Oxfendazole did not exhibit genetic toxicology signals in standard Ames bacterial, mouse lymphoma, or rat micronucleus assays nor did it provoke safety concerns when evaluated for behavioral effects in rats or cardiovascular safety effects in dogs. These results support the transition of oxfendazole to First in Human safety studies preliminary to its evaluation in human helminth diseases. PMID:25701764

  16. University Studies Diversity of Human Experience Note: In this scoring guide, "diversity" refers to differences in ethnic, religious, and

    E-print Network

    University Studies Diversity of Human Experience Note: In this scoring guide, "diversity" refers within the broader context of human experience, demonstrating a sophisticated awareness · discusses personal experience within the broader context of human experience, demonstrating a working

  17. Prolonged Use of Aspirin Alters Human and Rat Intestinal Cells and Thereby Limits the Absorption of Clopidogrel

    Microsoft Academic Search

    K-H Jung; K Chu; S-T Lee; H-J Yoon; J-Y Chang; W-S Nam; S-H Yoon; J-Y Cho; K-S Yu; I-J Jang; M Kim; S K Lee; J-K Roh

    2011-01-01

    Clopidogrel therapy to prevent atherothrombosis faces the challenge of reduced responsiveness. The absorption of clopidogrel is regulated by multidrug-resistance protein 1 (MDR1) in the intestinal epithelium. Given that aspirin induces MDR1 in cancer cells and peripheral blood cells, it may induce MDR1 in intestinal epithelial cells as well, thereby affecting the absorption of clopidogrel. In this study, aspirin treatment induced

  18. Occupational and public health considerations for work-hour limitations policy regarding public health workers during response to natural and human-caused disasters.

    PubMed

    Berkowitz, Murray R

    2012-01-01

    This article examines the occupational health considerations that might impact the health and wellbeing of public health workers during responses to natural (eg, floods and hurricanes) and human-caused (eg, terrorism, war, and shootings) disasters. There are a number of articles in the medical literature that argue the impact of how working long hours by house staff physicians, nurses, and first-responders may pose health and safety concerns regarding the patients being treated. The question examined here is how working long hours may pose health and/or safety concerns for the public health workers themselves, as well as to those in the communities they serve. The health problems related to sleep deprivation are reviewed. Current policies and legislations regarding work-hour limitations are examined. Policy implications are discussed. PMID:23140062

  19. Prevalence, Acquisition, and Clearance of Cervical Human Papillomavirus Infection among Women with Normal Cytology: Hawaii Human Papillomavirus Cohort Study

    Microsoft Academic Search

    Marc T. Goodman; Yurii B. Shvetsov; Katharine McDuffie; Lynne R. Wilkens; Xuemei Zhu; Pamela J. Thompson; Lily Ning; Jeffrey Killeen; Lori Kamemoto; Brenda Y. Hernandez

    Few natural history studies of cervical human papillomavirus (HPV) incidence and duration have been conducted among older women, especially from multiethnic populations. Viral and nonviral determinants of HPV acquisition and clearance were examined among 972 sexually active women, ages 18 to 85 years, recruited from clinics on Oahu, Hawaii, and followed for a mean duration of 15 months (range, 2-56

  20. On Distinguishing Competence from Performance in Studies of Human Communication.

    ERIC Educational Resources Information Center

    Sanders, Robert E.

    Given that overt linguistic behavior is not an adequate or primary datum for linguistic theory and that linguistic theory cannot directly account for overt linguistic behavior, human language can be seen as an abstract system that relates (graphic or phonetic) surface representations of sentences and underlying grammatical forms and semantic…