These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

SciTech Connect

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.

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

1994-08-01

2

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

Microsoft Academic Search

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

W. Slob; M. N. Pieters

1998-01-01

3

Overcoming Current Limitations in Humanized Mouse Research  

PubMed Central

Immunodeficient mice engrafted with human cells and tissues have provided an exciting alternative to in vitro studies with human tissues and nonhuman primates for the study of human immunobiology. A major breakthrough in the early 2000s was the introduction of a targeted mutation in the interleukin 2 (IL-2) receptor common gamma chain (IL2rgnull) into mice that were already deficient in T and B cells. Among other immune defects, natural killer (NK) cells are disrupted in these mice, permitting efficient engraftment with human hematopoietic cells that generate a functional human immune system. These humanized mouse models are becoming increasingly important for preclinical studies of human immunity, hematopoiesis, tissue regeneration, cancer, and infectious diseases. In particular, humanized mice have enabled studies of the pathogenesis of human-specific pathogens, including human immunodeficiency virus type 1, Epstein Barr virus, and Salmonella typhi. However, there are a number of limitations in the currently available humanized mouse models. Investigators are continuing to identify molecular mechanisms underlying the remaining defects in the engrafted human immune system and are generating “next generation” models to overcome these final deficiencies. This article provides an overview of some of the emerging models of humanized mice, their use in the study of infectious diseases, and some of the remaining limitations that are currently being addressed. PMID:24151318

Brehm, Michael A.; Shultz, Leonard D.; Luban, Jeremy; Greiner, Dale L.

2013-01-01

4

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

NSDL National Science Digital Library

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 .

1900-01-01

5

Human Rights Watch: Limits of Tolerance  

NSDL National Science Digital Library

Human Rights Watch has recently posted a new report. "Limits of Tolerance: Freedom of Expression and the Public Debate in Chile," examines the extreme restrictions on freedom of speech and freedom of information in the ostensibly democratic nation of Chile.

6

Human exploration mission studies  

NASA Technical Reports Server (NTRS)

The Office of Exploration has established a process whereby all NASA field centers and other NASA Headquarters offices participate in the formulation and analysis of a wide range of mission strategies. These strategies were manifested into specific scenarios or candidate case studies. The case studies provided a systematic approach into analyzing each mission element. First, each case study must address several major themes and rationale including: national pride and international prestige, advancement of scientific knowledge, a catalyst for technology, economic benefits, space enterprise, international cooperation, and education and excellence. Second, the set of candidate case studies are formulated to encompass the technology requirement limits in the life sciences, launch capabilities, space transfer, automation, and robotics in space operations, power, and propulsion. The first set of reference case studies identify three major strategies: human expeditions, science outposts, and evolutionary expansion. During the past year, four case studies were examined to explore these strategies. The expeditionary missions include the Human Expedition to Phobos and Human Expedition to Mars case studies. The Lunar Observatory and Lunar Outpost to Early Mars Evolution case studies examined the later two strategies. This set of case studies established the framework to perform detailed mission analysis and system engineering to define a host of concepts and requirements for various space systems and advanced technologies. The details of each mission are described and, specifically, the results affecting the advanced technologies required to accomplish each mission scenario are presented.

Cataldo, Robert L.

1989-01-01

7

Human factor and computational intelligence limitations in resilient control systems  

E-print Network

Human factor and computational intelligence limitations in resilient control systems Bogdan M. Wilamowski Auburn University Abstract - Humans are very capable of solving many scientific and engineering problems, but during the solution process they have a tendency to make mistakes. For example, humans

Wilamowski, Bogdan Maciej

8

Limiting Reactants: Industrial Case Study  

NSDL National Science Digital Library

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.

Dave Blackburn

9

Experimental studies on pump limiters  

SciTech Connect

Pump limiters are mechanical devices for He-ash removal, fuel particle control, and possibly impurity control. Different designs have been suggested by various authors over the past decade. However, the magnetic divertor concepts seemed to be more promising, mainly because of their remote plasma-material interactions. All of the characteristics of magnetic divertors have been proven experimentally, but the overall performance and complexity cause concern about their application to tokamak reactors. Consequently, it is time now to explore the potential of mechanical particle control devices, i.e. pump limiters. Because of the high recycling at the limiter, it is sufficient to exhaust only a small fraction, about 1 to 10%, of the limiter particle flux to remove e.g. He at its rate of production. Pump limiter experiments have been conducted so far on Alcator, PDX, Macrotor, and ISX. Depending on the experimental design, a pressure build-up of between 1 mTorr and 50 mTorr has been reported.

Mioduszewski, P.

1982-01-01

10

Approaching the Limit of Predictability in Human Mobility  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

11

Human exposure limits to hypergolic fuels  

NASA Technical Reports Server (NTRS)

Over the past four decades, many studies have been conducted on the toxicities of the rocket propellants hydrazine (HZ) and monomethylhydrazine (MH). Numerous technical challenges have made it difficult to unambiguously interpret the results of these studies, and there is considerable divergence between results obtained by different investigators on the inhalation concentrations (MAC's) for each toxic effect inducible by exposure to hypergolic fuels in spacecraft atmospheres, NASA undertook a critical review of published and unpublished investigations on the toxicities of these compounds. The current state of the art practices for similar studies. While many questions remain unanswered, MAC's were determined using the best available data for a variety of toxic endpoints for potential continuous exposure durations ranging from 1 hour to 180 days. Spacecraft MAC's (SMAC's) were set for each compound based on the most sensitive toxic endpoint at each exposure duration.

Garcia, H. D.; James, J. T.; Limero, T. F.

1992-01-01

12

Food availability at birth limited reproductive success in historical humans.  

PubMed

Environmental conditions in early life can profoundly affect individual development and have consequences for reproductive success. Limited food availability may be one of the reasons for this, but direct evidence linking variation in early-life nutrition to reproductive performance in adulthood in natural populations is sparse. We combined historical agricultural data with detailed demographic church records to investigate the effect of food availability around the time of birth on the reproductive success of 927 men and women born in 18th-century Finland. Our study population exhibits natural mortality and fertility rates typical of many preindustrial societies, and individuals experienced differing access to resources due to social stratification. We found that among both men and women born into landless families (i.e., with low access to resources), marital prospects, probability of reproduction, and offspring viability were all positively related to local crop yield during the birth year. Such effects were generally absent among those born into landowning families. Among landless individuals born when yields of the two main crops, rye and barley, were both below median, only 50% of adult males and 55% of adult females gained any reproductive success in their lifetime, whereas 97% and 95% of those born when both yields were above the median did so. Our results suggest that maternal investment in offspring in prenatal or early postnatal life may have profound implications for the evolutionary fitness of human offspring, particularly among those for which resources are more limiting. Our study adds support to the idea that early nutrition can limit reproductive success in natural animal populations, and provides the most direct evidence to date that this process applies to humans. PMID:21302824

Rickard, Ian J; Holopainen, Jari; Helama, Samuli; Helle, Samuli; Russell, Andrew F; Lummaa, Virpi

2010-12-01

13

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

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

1984-01-01

14

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

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.

1984-01-01

15

Human exploration mission studies  

NASA Technical Reports Server (NTRS)

This paper describes several case studies of human space exploration, considered by the NASA's Office of Exploration in 1988. Special attention is given to the mission scenarios, the critical technology required in these expeditions, and the extraterrestrial power requirements of significant system elements. The cases examined include a manned expedition to Phobos, the inner Martian moon; a human expedition to Mars; the Lunar Observatory; and a lunar outpost to early Mars evolution.

Cataldo, Robert L.

1990-01-01

16

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

The progress made on the Teleoperator Human Factors Study program during the period of September 7, 1985 to October 6, 1985 is discussed. Technical and programmatic problems that were encountered are discussed along with activity planned for the following month. The main portion of the report has been separated into four sections: Work Performed, Future Work, Problems Encountered, and Cost Information.

Bradford, K. Z.; Schappell, R. T.

1985-01-01

17

Studies on the dynamics of limited filaments  

E-print Network

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 ...

Bonde, Jeffrey David

2010-01-01

18

The Limits of Narrative: Provocations for the Medical Humanities  

PubMed Central

This paper aims to (re)ignite debate about the role of narrative in the medical humanities. It begins with a critical review of the ways in which narrative has been mobilised by humanities and social science scholars to understand the experience of health and illness. I highlight seven dangers or blind spots in the dominant medical humanities approach to narrative, including the frequently unexamined assumption that all human beings are “naturally narrative.” I then explore this assumption further through an analysis of philosopher Galen Strawson’s influential article “Against Narrativity.” Strawson rejects the descriptive claim that “human beings typically see or live or experience their lives as a narrative” and the normative claim that “a richly Narrative outlook is essential to a well-lived life, to true or full personhood.” His work has been taken up across a range of disciplines but its implications in the context of health and illness have not yet been sufficiently discussed. This article argues that “Against Narrativity” can and should stimulate robust debate within the medical humanities regarding the limits of narrative, and concludes by discussing a range of possibilities for venturing “beyond narrative.” PMID:22038696

Woods, Angela

2014-01-01

19

Pumped-limiter study for Alcator DCT  

SciTech Connect

A study was performed for a pumped-limiter design for the proposed Alcator DCT device. The study focused on reactor-relevant issues. The main issues examined were configuration, surface erosion, thermal hydraulics, and the choice of structural and surface materials. A bottom, flat limiter, with a copper-alloy substrate, seems to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon is recommended as a surface material if acceptable redeposition properties can be demonstrated.

Brooks, J.N.; Mattas, R.F.; Cha, Y.S.; Hassanein, A.M.; Majumdar, S.

1983-06-01

20

HUMANITIES SCHOLARS APPLICATION Africana Studies  

E-print Network

HUMANITIES SCHOLARS APPLICATION MAJORS Africana Studies American Studies Ancient Studies Anthropology, Cultural Asian Studies English Gender and Women's Studies History Media and Communication Studies Modern Languages, Linguistics and Intercultural Communication Philosophy Interdisciplinary Studies #12

Maryland, Baltimore County, University of

21

The Limits of Human Stereopsis in Space and Time  

PubMed Central

To encode binocular disparity, the visual system determines the image patches in one eye that yield the highest correlation with patches in the other eye. The computation of interocular correlation occurs after spatiotemporal filtering of monocular signals, which leads to restrictions on disparity variations that can support depth perception. We quantified those restrictions by measuring humans' ability to see disparity variation at a wide range of spatial and temporal frequencies. Lower-disparity thresholds cut off at very low spatiotemporal frequencies, which is consistent with the behavior of V1 neurons. Those thresholds are space–time separable, suggesting that the underlying neural mechanisms are separable. We also found that upper-disparity limits were characterized by a spatiotemporal, disparity-gradient limit; to be visible, disparity variation cannot exceed a fixed amount for a given interval in space–time. Our results illustrate that the disparity variations that humans can see are very restricted compared with the corresponding luminance variations. The results also provide insight into the neural mechanisms underlying depth from disparity, such as why stimuli with long interocular delays can still yield clear depth percepts. PMID:24453329

Kane, David; Guan, Phillip

2014-01-01

22

Human Paraoxonase 1 as a Pharmacologic Agent: Limitations and Perspectives  

PubMed Central

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

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

2014-01-01

23

Human macrophages limit oxidation products in low density lipoprotein  

Microsoft Academic Search

This study tested the hypothesis that human macrophages have the ability to modify oxidation products in LDL and oxidized LDL (oxLDL) via a cellular antioxidant defence system. While many studies have focused on macrophage LDL oxidation in atherosclerosis development, less attention has been given to the cellular antioxidant capacity of these cells. Compared to cell-free controls (6.2 ± 0.7 nmol\\/mg

Lillemor Mattsson Hultén; Christina Ullström; Alexandra Krettek; David van Reyk; Stefan L Marklund; Claes Dahlgren; Olov Wiklund

2005-01-01

24

HUMAN DEVELOPMENT Program of Study  

E-print Network

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

Thomas, Andrew

25

Limited communication capacity unveils strategies for human interaction  

PubMed Central

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. PMID:23739519

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

2013-01-01

26

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

PubMed

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

Smith, P

1999-01-01

27

Studies That Observe Humans  

MedlinePLUS

... information can be a good place to start. Case control studies: These studies look at people who already have ... got cancer and the other didn’t. Most case-control studies are retrospective (meaning that they look back at ...

28

Scrapeoff layer studies with an instrumented limiter  

SciTech Connect

An instrumented limiter was used as a diagnostic to measure energy deposition and power fluxes in the scrapeoff layer. The limiter consisted of an array of 12 tiles, each equipped with a thermocouple. This arrangement represented a calorimeter array that yielded the total limiter energy and decay length of the power flux in the scrapeoff layer. Energy deposition and decay lengths are discussed for various plasma parameters.

Mioduszewski, P.; Edmonds, P.H.; Emerson, L.C.; Simpkins, J.E.

1986-01-01

29

Physiology for High School - Human Physiological Limits to Exploring Mars  

NSDL National Science Digital Library

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.

PhD James A Pawelczyk (Pennsylvania State University)

2008-04-05

30

Safety Impacts of Variable Speed Limits - A Simulation Study  

Microsoft Academic Search

Variable speed limits have great potential for smoothing traffic and increasing traffic safety. In this study, safety impacts of variable speed limits applications on motorways have been assessed by using microscopic simulation. The main factors considered include range of speed limits, penetration rates, and enforcement levels. The study results show that application of variable speed limits on motorways can significantly

J. Piao; M. McDonald

2008-01-01

31

Analysis of environmental factors limiting humans' obstacle avoidance ability  

Microsoft Academic Search

We conjecture that action intelligence of humans could contribute to the path-planning problem of autonomous mobile robot. In order to achieve the imitation of such action intelligence on a robot, besides action knowledge acquisition, we need to further learn more about the characteristics of humans' action intelligence. In this paper, from the viewpoint of attributes of an obstacle such as

TQO Shang; Shop Wang

2005-01-01

32

Inhibition of telomerase limits the growth of human cancer cells  

Microsoft Academic Search

Telomerase is a ribonucleoprotein enzyme that maintains the protective structures at the ends of eukaryotic chromosomes, called telomeres. In most human somatic cells, telomerase expression is repressed, and telomeres shorten progressively with each cell division. In contrast, most human tumors express telomerase, resulting in stabilized telomere length. These observations indicate that telomere maintenance is essential to the proliferation of tumor

William C. Hahn; Sheila A. Stewart; Mary W. Brooks; Shoshana G. York; Elinor Eaton; Akiko Kurachi; Roderick L. Beijersbergen; Joan H. M. Knoll; Matthew Meyerson; Robert A. Weinberg

1999-01-01

33

Humanities and the Social Studies.  

ERIC Educational Resources Information Center

Writers representing diverse backgrounds and professional interests have contributed essays to this collection on the relationship between these two disciplines. Contributors were asked to sketch areas in the humanities which might be used in the social studies, and to discuss how the ideas, attitudes, philosophies, and information might be…

Powell, Thomas F., Ed.

34

Human embryonic stem cell culture: current limitations and novel strategies  

Microsoft Academic Search

Embryonic stem cells (ESC) are multipotent cells isolated from blastocyst-stage preimplantation embryos. Since their first culture in 1998, human ESC have revolutionized reproductive and regenerative medicine by allowing the establishment of detailed molecular and therapeutic models for certain metabolic pathways and life-threatening disorders. They also offer significant contributions to genetics and pharmacology in designing and analysing disease models that can

N Findikli; NZ Candan; S Kahraman

2006-01-01

35

Limiter  

DOEpatents

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19

36

Limits of responsiveness concerning human-readable knowledge bases: an operational analysis  

E-print Network

Introduction. The purpose of this work is the evaluation of responsiveness when remote users communicate with a human-readable knowledge base (KB). Responsiveness [R(s)] is considered here as a measure of service quality. Method. The preferred method is operational analysis, a variation of classical stochastic theory, which allows for the study of user-system interaction with minimal computational effort. Analysis. The analysis is based on well-known performance metrics, such as service ability, elapsed time, and throughput: from these metrics estimates of R(s) are derived analytically. Results. Critical points indicating congestion are obtained: these are limits on the number of admissible requests and the number of connected users. Also obtained is a sufficient condition for achieving flow balance between the KB host and the request-relaying servers. Conclusions. When R(s) is within normal limits, users should appreciate the benefits from using the services offered by their KB host. When bottlenecks are for...

Pentzaropoulos, G C

2010-01-01

37

47 CFR 5.93 - Limited market studies.  

Code of Federal Regulations, 2012 CFR

...or receiving equipment used in the study shall be owned by the licensee...the Commission shall establish on a case-by-case basis. If the Commission subsequently determines that a market study is not so limited, the study...

2012-10-01

38

47 CFR 5.93 - Limited market studies.  

Code of Federal Regulations, 2010 CFR

...or receiving equipment used in the study shall be owned by the licensee...the Commission shall establish on a case-by-case basis. If the Commission subsequently determines that a market study is not so limited, the study...

2010-10-01

39

47 CFR 5.93 - Limited market studies.  

Code of Federal Regulations, 2011 CFR

...or receiving equipment used in the study shall be owned by the licensee...the Commission shall establish on a case-by-case basis. If the Commission subsequently determines that a market study is not so limited, the study...

2011-10-01

40

237Poverty and Human Capability Studies Poverty and Human  

E-print Network

237Poverty and Human Capability Studies Poverty and Human CaPability StudieS (Pov) Core FaCulty: PROFESSORS beCKley*, GOLDSMITH, MARGAND The Shepherd Program for the interdisciplinary Study of Poverty and graduate studies can prepare them as futureprofessionalsandcitizenstoaddresstheproblems of poverty and how

Dresden, Gregory

41

Pineal melatonin level disruption in humans due to electromagnetic fields and ICNIRP limits.  

PubMed

The International Agency for Research on Cancer (IARC) classifies electromagnetic fields (EMFs) as 'possibly carcinogenic' to humans that might transform normal cells into cancer cells. Owing to high utilisation of electricity in day-to-day life, exposure to power-frequency (50 or 60 Hz) EMFs is unavoidable. Melatonin is a natural hormone produced by pineal gland activity in the brain that regulates the body's sleep-wake cycle. How man-made EMFs may influence the pineal gland is still unsolved. The pineal gland is likely to sense EMFs as light but, as a consequence, may decrease the melatonin production. In this study, more than one hundred experimental data of human and animal studies of changes in melatonin levels due to power-frequency electric and magnetic fields exposure were analysed. Then, the results of this study were compared with the International Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental results in the literature for the biological effect of magnetic fields, in order to quantify the effects. The results show that this comparison does not seem to be consistent despite the fact that it offers an advantage of drawing attention to the importance of the exposure limits to weak EMFs. In addition to those inconsistent results, the following were also observedfrom this work: (i) the ICNIRP recommendations are meant for the well-known acute effects, because effects of the exposure duration cannot be considered and (ii) the significance of not replicating the existing experimental studies is another limitation in the power-frequency EMFs. Regardless of these issues, the above observation agrees with our earlier study in which it was confirmed that it is not a reliable method to characterise biological effects by observing only the ratio of AC magnetic field strength to frequency. This is because exposure duration does not include the ICNIRP limit. Furthermore, the results show the significance of disruption of melatonin due to exposure to weak EMFs, which may possibly lead to long-term health effects in humans. PMID:23051584

Halgamuge, Malka N

2013-05-01

42

Limiter  

DOEpatents

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1986-01-01

43

Limits  

NSDL National Science Digital Library

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.

2013-06-21

44

Utility, Limitations, and Future of Non-Human Primates for Dengue Research and Vaccine Development  

PubMed Central

Dengue is considered the most important emerging, human arboviruses, with worldwide distribution in the tropics. Unfortunately, there are no licensed dengue vaccines available or specific anti-viral drugs. The development of a dengue vaccine faces unique challenges. The four serotypes co-circulate in endemic areas, and pre-existing immunity to one serotype does not protect against infection with other serotypes, and actually may enhance severity of disease. One foremost constraint to test the efficacy of a dengue vaccine is the lack of an animal model that adequately recapitulates the clinical manifestations of a dengue infection in humans. In spite of this limitation, non-human primates (NHP) are considered the best available animal model to evaluate dengue vaccine candidates due to their genetic relatedness to humans and their ability to develop a viremia upon infection and a robust immune response similar to that in humans. Therefore, most dengue vaccines candidates are tested in primates before going into clinical trials. In this article, we present a comprehensive review of published studies on dengue vaccine evaluations using the NHP model, and discuss critical parameters affecting the usefulness of the model. In the light of recent clinical data, we assess the ability of the NHP model to predict immunological parameters of vaccine performances in humans and discuss parameters that should be further examined as potential correlates of protection. Finally, we propose some guidelines toward a more standardized use of the model to maximize its usefulness and to better compare the performance of vaccine candidates from different research groups. PMID:25309540

Sariol, Carlos A.; White, Laura J.

2014-01-01

45

Limitations to the study of man in the United States space program  

NASA Technical Reports Server (NTRS)

Research on humans conducted during space flight is fraught both with great opportunities and great obstacles. The purpose of this paper is to review some of the limitations to United States research in space in the hope that an informed scientific community may lead to more rapid and efficient solution of these problems. Limitations arise because opportunities to study the same astronauts in well-controlled situations on repeated space flights are practically non-existent. Human research opportunities are further limited by the necessity of avoiding simultaneous mutually-interfereing experiments. Environmental factors including diet and other physiological perturbations concomitant with space flight also complicates research design and interpretation. Technical limitations to research methods and opportunities further restrict the development of the knowledge base. Finally, earth analogues of space travel all suffer from inadequacies. Though all of these obstacles will eventually be overcome; creativity, diligence, and persistence are required to further our knowledge of humans in space.

Bishop, Phillip A.; Greenisen, Mike

1992-01-01

46

Limitations to the study of man in space in the U.S. space program  

NASA Technical Reports Server (NTRS)

Research on humans conducted during spaceflight is fraught both with great opportunities and great obstacles. The purpose of this paper is to review some of the limitations to research in space in the United States with hope that an informed scientific community may lead to more rapid and efficient solution of these problems. Limitations arise because opportunities to study the same astronauts in well-controlled situations on repeated spaceflights are practically non-existent. Human research opportunities are further limited by the necessity of avoiding simultaneous mutually-interfering experiments. Environmental factors, including diet and other physiological perturbations concomitant with spaceflight, also complicate research design and interpretation. Technical limitations to research methods and opportunities further restrict the development of the knowledge base. Finally, Earth analogues of space travel all suffer from inadequacies. Though all of these obstacles will eventually be overcome, creativity, diligence, and persistence are required to further our knowledge of humans in space.

Bishop, Phillip A.; Greenisen, Mike

1993-01-01

47

227Poverty and Human Capability Studies Poverty AND HUMAN  

E-print Network

227Poverty and Human Capability Studies Poverty AND HUMAN CAPABILIty StUDIeS (Pov) Core FACULty: PROFESSORS BeCKLey*, GOLDSMITH, MARGAND The Shepherd Program for the Interdisciplinary Study of Poverty studies can prepare them as future professionals and citizens to address the problems of poverty

Dresden, Gregory

48

The Importance of Human Data in the Establishment of Occupational Exposure Limits  

Microsoft Academic Search

The use of animal vs. human data for the purposes of establishing human risk was examined for four pharmaceutical compounds: acetylsalicylic acid, cyclophosphamide, indomethacin and clofibric acid. Literature searches were conducted to identify preclinical and clinical data useful for the derivation of acceptable daily intakes (ADIs) from which a number of risk values including occupational exposure limits (OELs) could be

Edward V. Sargent; Bruce D. Naumann; David G. Dolan; Ellen C. Faria; Lisa Schulman

2002-01-01

49

Numerical human models for accident research and safety - potentials and limitations.  

PubMed

The method of numerical simulation is frequently used in the area of automotive safety. Recently, numerical models of the human body have been developed for the numerical simulation of occupants. Different approaches in modelling the human body have been used: the finite-element and the multibody technique. Numerical human models representing the two modelling approaches are introduced and the potentials and limitations of these models are discussed. PMID:18431848

Praxl, Norbert; Adamec, Jiri; Muggenthaler, Holger; von Merten, Katja

2008-01-01

50

Seed, dispersal, microsite, habitat and recruitment limitation: identification of terms and concepts in studies of limitations  

Microsoft Academic Search

Recently, there is an increase in number of studies concerned with the effect of various types of limitations on species local\\u000a population size and distribution pattern at the landscape scale. The terminology used to describe these limitations is, however,\\u000a very inconsistent. Since the different terms often appear in conclusions of the papers, the inconsistency in their use obscures\\u000a the message

Zuzana Münzbergová; Tomáš Herben

2005-01-01

51

Limited By Cost: The Case Against Humans In The Scientific Exploration Of Space  

NASA Astrophysics Data System (ADS)

Human space flight represents a heady mix of bravery and drama which can be inspirational to nations and to humankind but at huge economic cost. Due to the current high launch costs only a handful of people have ventured beyond low Earth orbit and walked on the Moon, propelled by aspirations related more to the Cold War than to science. Problems with reusable launch vehicle development mean that severe launch cost limitations will exist for some time. Meanwhile, cheaper robotic probes have visited all the planets except Pluto, flown by comets, landed on Mars, Venus and an asteroid, have probed Jupiter's atmosphere and studied the Universe beyond our own solar system with telescopes. Using these data we are determining mankind's place in the Universe. Public interest in the historic Eros landing eclipsed a simultaneous space walk at the fledgling International Space Station and the Mars Pathfinder landing generated hundreds of millions of website hits in a few days. Given the fact that hundreds of Mars missions could be flown for the still-escalating cost of the International Space Station, the unsuitability of human bodies for deep space exploration, and the advances in 3-d and virtual reality techniques, we discuss whether human exploration needs a place in a realistic, useful and inspirational space programme.

Coates, Andrew J.

2001-11-01

52

Safe human exposure limits for airborne linear siloxanes during spaceflight  

PubMed Central

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

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

2013-01-01

53

Human Immunodeficiency Virus Type 1 Pathobiology Studied in Humanized BALB/c-Rag2?/??c?/? Mice?  

PubMed Central

The specificity of human immunodeficiency virus type 1 (HIV-1) for human cells precludes virus infection in most mammalian species and limits the utility of small animal models for studies of disease pathogenesis, therapy, and vaccine development. One way to overcome this limitation is by human cell xenotransplantation in immune-deficient mice. However, this has proved inadequate, as engraftment of human immune cells is limited (both functionally and quantitatively) following transplantation of mature human lymphocytes or fetal thymus/liver. To this end, a human immune system was generated from umbilical cord blood-derived CD34+ hematopoietic stem cells in BALB/c-Rag2?/??c?/? mice. Intrapartum busulfan administration followed by irradiation of newborn pups resulted in uniform engraftment characterized by human T-cell development in thymus, B-cell maturation in bone marrow, lymph node development, immunoglobulin M (IgM)/IgG production, and humoral immune responses following ActHIB vaccination. Infection of reconstituted mice by CCR5-coreceptor utilizing HIV-1ADA and subtype C 1157 viral strains elicited productive viral replication and lymphadenopathy in a dose-dependent fashion. We conclude that humanized BALB/c-Rag2?/??c?/? mice represent a unique and valuable resource for HIV-1 pathobiology studies. PMID:17182671

Gorantla, Santhi; Sneller, Hannah; Walters, Lisa; Sharp, John G.; Pirruccello, Samuel J.; West, John T.; Wood, Charles; Dewhurst, Stephen; Gendelman, Howard E.; Poluektova, Larisa

2007-01-01

54

Human immunodeficiency virus type 1 pathobiology studied in humanized BALB/c-Rag2-/-gammac-/- mice.  

PubMed

The specificity of human immunodeficiency virus type 1 (HIV-1) for human cells precludes virus infection in most mammalian species and limits the utility of small animal models for studies of disease pathogenesis, therapy, and vaccine development. One way to overcome this limitation is by human cell xenotransplantation in immune-deficient mice. However, this has proved inadequate, as engraftment of human immune cells is limited (both functionally and quantitatively) following transplantation of mature human lymphocytes or fetal thymus/liver. To this end, a human immune system was generated from umbilical cord blood-derived CD34(+) hematopoietic stem cells in BALB/c-Rag2(-/-)gamma(c)(-/-) mice. Intrapartum busulfan administration followed by irradiation of newborn pups resulted in uniform engraftment characterized by human T-cell development in thymus, B-cell maturation in bone marrow, lymph node development, immunoglobulin M (IgM)/IgG production, and humoral immune responses following ActHIB vaccination. Infection of reconstituted mice by CCR5-coreceptor utilizing HIV-1(ADA) and subtype C 1157 viral strains elicited productive viral replication and lymphadenopathy in a dose-dependent fashion. We conclude that humanized BALB/c-Rag2(-/-)gamma(c)(-/-) mice represent a unique and valuable resource for HIV-1 pathobiology studies. PMID:17182671

Gorantla, Santhi; Sneller, Hannah; Walters, Lisa; Sharp, John G; Pirruccello, Samuel J; West, John T; Wood, Charles; Dewhurst, Stephen; Gendelman, Howard E; Poluektova, Larisa

2007-03-01

55

Humanized Mouse Model to Study Bacterial Infections Targeting the Microvasculature  

PubMed Central

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

Melican, Keira; Aubey, Flore; Duménil, Guillaume

2014-01-01

56

Epidemiological studies in human radiobiology*  

PubMed Central

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

1967-01-01

57

Communicable disease surveillance with limited resources: the scope to link human and veterinary programmes.  

PubMed

Zoonoses are an important cause of human disease in much of Africa, but limitations in current diagnosis and surveillance strategies restrict the effectiveness of control and prevention programmes. Outbreaks of disease, ranging from Ebola virus infection to Rift Valley Fever, that have occurred recently in Africa have demonstrated the need for improved disease surveillance and monitoring. Strategies are suggested for co-ordinating human and animal disease surveillance programmes, at the district and regional level, to make more effective use of limited resources. PMID:10913758

Shears, P

2000-07-21

58

Use of human tissue explants to study human infectious agents  

PubMed Central

The study of human cell–cell and cell–pathogen interactions that occur in the context of complex tissue cytoarchitecture is critical for deciphering the mechanisms of many normal and pathogenic processes. This protocol describes methods for culturing and infecting explants of human tissues to study the pathogenesis of human infectious agents and their local interactions. The protocol relies on the use of fresh human tissues dissected into small blocks or biopsies that are cultured at the liquid–air interface on collagen rafts. These tissue blocks retain their cytoarchitecture and support productive infection of various pathogens without exogenous stimulation. Experimental details for setting up cultures of human tonsils, lymph nodes and cervicovaginal and rectosigmoid tissues, including protocols for their infection with HIV-1 and other pathogens, are described here. Using this protocol, culture and infections can be set up in 3–6 h and be maintained for 2–3 weeks, depending on the tissue used. PMID:19197269

Grivel, Jean-Charles; Margolis, Leonid

2012-01-01

59

DEVELOPMENT OF A DRIVING SIMULATOR FOR HUMAN VEHICLE INTERACTION STUDIES  

Microsoft Academic Search

Driving simulators are a valuable resource for human-vehicle interaction studies. Unfortunately, commercially available driving simulators are expensive and use software that sometimes offers limited flexibility or customizability. Exploiting the maximum potential of simulation requires that all aspects of the simulation software and the virtual driving environment be adjustable. However, in creating custom hardware\\/software for simulator usage, it is difficult to

M. D. Petersheim; S. P. Clewell; S. N. Brennan; C. M. LaJambe; M. El-Gindy; F. M. Brown

60

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

E-print Network

to weak EMFs, which may possibly lead to long-term health effects in humans. INTRODUCTION Melatonin Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental for the well-known acute effects, because effects of the exposure duration cannot be considered and (ii

Halgamuge, Malka N.

61

Studies of the limit order book around large price changes  

NASA Astrophysics Data System (ADS)

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 quantities is generally very slow that can be described by a power law of exponent ? 0.4. We introduce a numerical model in order to understand the empirical results better. We find that with a zero intelligence deposition model of the order flow the empirical results can be reproduced qualitatively. This suggests that the slow relaxations might not be results of agents' strategic behaviour. Studying the difference between the exponents found empirically and numerically helps us to better identify the role of strategic behaviour in the phenomena. in here

Tóth, B.; Kertész, J.; Farmer, J. D.

2009-10-01

62

Finite element method-based calculation of the theoretical limit of sensitivity for detecting weak magnetic fields in the human brain using magnetic-resonance imaging  

Microsoft Academic Search

Detection of weak magnetic fields induced by neuronal electrical activities using magnetic-resonance imaging is a potentially effective method for functional imaging of the brain. In this study, we performed a numerical analysis of the theoretical limit of sensitivity for detecting weak magnetic fields induced in the human brain. The limit of sensitivity was estimated from the intensities of signal and

Tomohisa Hatada; Masaki Sekino; Shoogo Ueno

2005-01-01

63

14.3 HUMAN SUBJECTS RESEARCH The Colorado School of Mines limits all research involving human subjects, whether or not the research  

E-print Network

14.3 HUMAN SUBJECTS RESEARCH The Colorado School of Mines limits all research involving human Transfer ("VPRTT"). In the case of human subject research approved by the Provost or VPRTT, the Principal of the project must be satisfied. CSM faculty or students engaged in research involving human subjects, whether

64

A Case Study on Exploring the Performance Limits of PRISM  

E-print Network

A Case Study on Exploring the Performance Limits of PRISM Wolfgang Schreiner Research Institute on a simple system model the range of applicability of the prob- abilistic model checker PRISM. In particular, and of other settings on the time and memory required for the analysis of the model by PRISM. The results

Schneider, Carsten

65

SANTA CREEK, BENEWAH COUNTY, IDAH - EFFLUENT LIMITATION STUDY. 1986  

EPA Science Inventory

A water quality study was initiated on Santa Creek, Idaho (17010304) to determine if new effluent limitations are necessary for the discharge from the City of Emida wastewater lagoon. The City of Emida provides secondary treatment of domestic sewage in an unaerated facultative l...

66

Identification of the human cytochromes P450 catalysing the rate-limiting pathways of gliclazide elimination  

PubMed Central

What is already known about this subject Gliclazide is a widely used oral hypoglycaemic agent. The major metabolites of gliclazide formed in vivo have been identified. However, the cytochrome P450 enzymes catalysing the rate-limiting pathways of gliclazide elimination are unknown. What this study adds CYP2C9 is the major enzyme involved in the various hydroxylation pathways of gliclazide, although a contribution of CYP2C19 to tolymethylhydroxylation, the major metabolic route, cannot be discounted. Factors known to influence CYP2C9 activity will provide the main source of variability in gliclazide pharmacokinetics. Aims To identify the human cytochrome P450 (CYP) enzymes responsible for the formation of the 6?-hydroxy (6?-OHGz), 7?-hydroxy (7?-OHGz) and hydroxymethyl (MeOH-Gz) metabolites of gliclizide (Gz). Methods 6?-OHGz, 7?-OHGz and MeOH-Gz formation by human liver microsomes and a panel of recombinant human P450s was measured using a high-performance liquid chromatography procedure, and the kinetics of metabolite formation was determined for each pathway. Effects of prototypic CYP enzyme selective inhibitors were characterized for each of the microsomal metabolic pathways. Results Microsomes from six human livers converted Gz to its 6?-OHGz, 7?-OHGz, and MeOH-Gz metabolites, with respective mean (± SD) Km values of 461 ± 139, 404 ± 143 and 334 ± 75 µm and mean Vmax values of 130 ± 55, 82 ± 31 and 268 ± 115 pmol min?1 mg?1, respectively. Vmax/Km ratios for the microsomal reactions parallelled relative metabolite formation in vivo. Sulfaphenazole inhibited microsomal 6?-OHGz, 7?-OHGz and MeOH-Gz formation by 87, 83 and 64%, respectively, whereas S-mephenytoin caused significant inhibition (48%) of only MeOH-Gz formation. Recombinant CYP2C9, CYP2C18 and CYP2C19 catalysed all hydroxylation pathways, whereas CYP2C8 formed only 6?-OHGz and 7?-OHGz. Conclusion Taken together, the results indicate that CYP2C9 is the major contributor to Gz metabolic clearance, although CYP2C19 may also be involved in MeOH-Gz formation (the major metabolic pathway). Factors known to influence CYP2C9 activity will provide the main source of variability in Gz pharmacokinetics. PMID:17517049

Elliot, David J; Suharjono; Lewis, Benjamin C; Gillam, Elizabeth M J; Birkett, Donald J; Gross, Annette S; Miners, John O

2007-01-01

67

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

Microsoft Academic Search

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

J. C. Stephens; D. Briscoe

1994-01-01

68

Human hypertrophic and keloid scar models: principles, limitations and future challenges from a tissue engineering perspective.  

PubMed

Most cutaneous wounds heal with scar formation. Ideally, an inconspicuous normotrophic scar is formed, but an abnormal scar (hypertrophic scar or keloid) can also develop. A major challenge to scientists and physicians is to prevent adverse scar formation after severe trauma (e.g. burn injury) and understand why some individuals will form adverse scars even after relatively minor injury. Currently, many different models exist to study scar formation, ranging from simple monolayer cell culture to 3D tissue-engineered models even to humanized mouse models. Currently, these high-/medium-throughput test models avoid the main questions referring to why an adverse scar forms instead of a normotrophic scar and what causes a hypertrophic scar to form rather than a keloid scar and also, how is the genetic predisposition of the individual and the immune system involved. This information is essential if we are to identify new drug targets and develop optimal strategies in the future to prevent adverse scar formation. This viewpoint review summarizes the progress on in vitro and animal scar models, stresses the limitations in the current models and identifies the future challenges if scar-free healing is to be achieved in the future. PMID:24750541

van den Broek, Lenie J; Limandjaja, Grace C; Niessen, Frank B; Gibbs, Susan

2014-06-01

69

Human locomotion through a multiple obstacle environment: strategy changes as a result of visual field limitation.  

PubMed

This study investigated how human locomotion through an obstacle environment is influenced by visual field limitation. Participants were asked to walk at a comfortable pace to a target location while avoiding multiple vertical objects. During this task, they wore goggles restricting their visual field to small (S: 40°×25°), medium (M: 80°×60°), large (L: 115°×90°), or unlimited (U) visual field sizes. Full-body motion capture was used to extract for each trial the mean speed, pathlength, mean step width, magnitude of head rotation and head mean angular speed. The results show that compared with the U condition, the M and L conditions caused participants to select a wider path around the obstacles without slowing down or altering step width. However, the S condition did slow down the participants, and increased both their step width and path length. We conclude that only for the S condition, balancing problems were substantial enough to spend more energy associated with increased step width. In all cases, participants choose to optimize safety (collision avoidance) at the cost of spending more energy. PMID:21687987

Jansen, Sander E M; Toet, Alexander; Werkhoven, Peter J

2011-07-01

70

Study of hepatitis C virus entry in genetically humanized mice  

PubMed Central

Approximately 2% of the world’s population is chronically infected with hepatitis C virus (HCV). Chronic hepatitis C can culminate in end stage liver disease and liver cancer if the infection is untreated. Current therapy is only partially effective and a vaccine for HCV does not exist. Since the discovery of HCV as the etiologic agent causing hepatitis C several experimental tools have been developed which have improved our understanding of the viral life cycle and the interaction of HCV with human cells. However, it remains challenging to study HCV infection in its native liver environment given its narrow species tropism, limited to humans and chimpanzees. Mice can be rendered susceptible to HCV infection by transplanting human hepatocytes into immunocompromized liver injury strains. Such human liver chimeric mice are useful as a challenge model for human hepatotropic pathogens but their utility is hampered by their inability to mount functional immune responses and practical aspects including high costs, low throughput, and donor-to-donor variability. The barriers that restrict HCV species tropism are incompletely understood. We have previously shown that expression of human CD81 and human OCLN is required for HCV uptake into mouse cells. This led to the construction of a genetically humanized mouse model for HCV infection. Here, we provide a detailed protocol for the generation of these animals and highlight some of its applications for studying HCV biology and preclinical testing of drug and vaccine candidates. PMID:22687621

Dorner, Marcus; Rice, Charles M.; Ploss, Alexander

2013-01-01

71

Technological advances for studying human behavior  

NASA Technical Reports Server (NTRS)

Technological advances for studying human behavior are noted in viewgraph form. It is asserted that performance-aiding systems are proliferating without a fundamental understanding of how they would interact with the humans who must control them. Two views of automation research, the hardware view and the human-centered view, are listed. Other viewgraphs give information on vital elements for human-centered research, a continuum of the research process, available technologies, new technologies for persistent problems, a sample research infrastructure, the need for metrics, and examples of data-link technology.

Roske-Hofstrand, Renate J.

1990-01-01

72

Finite element method-based calculation of the theoretical limit of sensitivity for detecting weak magnetic fields in the human brain using magnetic-resonance imaging  

NASA Astrophysics Data System (ADS)

Detection of weak magnetic fields induced by neuronal electrical activities using magnetic-resonance imaging is a potentially effective method for functional imaging of the brain. In this study, we performed a numerical analysis of the theoretical limit of sensitivity for detecting weak magnetic fields induced in the human brain. The limit of sensitivity was estimated from the intensities of signal and noise in the magnetic-resonance images. The signal intensity was calculated with parameters which are commonly used in measurements of the human brain. The noise due to the head was calculated using the finite element method. The theoretical limit of sensitivity was approximately 10-8T.

Hatada, Tomohisa; Sekino, Masaki; Ueno, Shoogo

2005-05-01

73

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

PubMed

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

Victor, Elizabeth

2014-12-01

74

Optical limiting and nonlinear optical studies of ferrocenyl substituted calixarenes  

NASA Astrophysics Data System (ADS)

Optical limiting behavior of three ferrocenyl substituted calixarenes (FSCs) where ferrocenyl group is attached via ethynyl(a), meta-(b) and para-(c) ethynyl phenyl spacers studied with nanosecond pulses at 532 nm is in the order c > a > b. While, with femtosecond laser pulses at 800 nm strength of nonlinearity is in the order c > b > a. Largest nonlinear refraction (n2 = 9.5 × 10-16 cm2/W) is estimated for the FSC c. Nonlinear absorption in these FSCs is attributed to three-photon absorption. Optical limiting behavior with nanosecond laser pulses is mainly due to thermal nonlinearity and reverse saturable absorption, whereas, with femtosecond laser pulses mainly intrinsic electronic nonlinearity contributes.

Singh, C. P.; Sharma, Rekha; Shukla, V.; Khundrakpam, P.; Misra, Rajneesh; Bindra, K. S.; Chari, Rama

2014-11-01

75

Studying dialects to understand human language  

E-print Network

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 ...

Nti, Akua Afriyie

2009-01-01

76

Gated viewing in the atmosphere: a study of performance limits  

NASA Astrophysics Data System (ADS)

The main purpose of the work presented here is to study the potential for an active imaging system for target recognition at long distances. This work is motivated by the fact that there are a number of outdoor imaging needs where conventional passive electro optical (EO) and infrared (IR) imaging systems are limited due to lack of photons, disturbing background, obscurants or bad weather. With a pulsed illuminating source, several of these problems are overcome. Using a laser for target illumination, target recognition at 10's of km can be achieved. Powerful diode pumped lasers and camera tubes with high spatial and time resolution will make this technique an interesting complement to passive EO imaging. Beside military applications, civilian applications of gated viewing for search and rescue, vehicle enhanced vision and other applications are in progress. To study the performance limitations of gated viewing systems due to camera, optics and the atmosphere an experimental system was developed. Measurements up to 10 km were made. The measurements were taken at the wavelength 532 nm. To extrapolate the results to future system performance at an eye safe wavelength, 1.5 micrometers nm, a theoretical performance model was developed. This model takes into account the camera and atmospheric influence on resolution and image quality, measured as a signal-to-noise-ratio, SNR. The result indicates turbulence influence, in agreement with the modeling. Different techniques were tested for image quality improvement and the best results were obtained by applying several processing techniques to the images. Moreover, the tests showed that turbulence seriously limits the resolution for horizontal paths close to the ground. A tactical system at 1.5 micrometers should have better performance than the used 532 nm in atmospheric-limited applications close to ground level. The potential to use existing laser range finders and the eye safety issue motivates the future use of 1.5 micrometers for gated viewing.

Klasen, Lena M.; Steinvall, Ove K.; Bolander, Goeran; Elmqvist, Magnus

2002-07-01

77

Identification of Multiple Rate-limiting Steps during the Human Mitochondrial Transcription Cycle in Vitro*  

PubMed Central

We have reconstituted human mitochondrial transcription in vitro on DNA oligonucleotide templates representing the light strand and heavy strand-1 promoters using protein components (RNA polymerase and transcription factors A and B2) isolated from Escherichia coli. We show that 1 eq of each transcription factor and polymerase relative to the promoter is required to assemble a functional initiation complex. The light strand promoter is at least 2-fold more efficient than the heavy strand-1 promoter, but this difference cannot be explained solely by the differences in the interaction of the transcription machinery with the different promoters. In both cases, the rate-limiting step for production of the first phosphodiester bond is open complex formation. Open complex formation requires both transcription factors; however, steps immediately thereafter only require transcription factor B2. The concentration of nucleotide required for production of the first dinucleotide product is substantially higher than that required for subsequent cycles of nucleotide addition. In vitro, promoter-specific differences in post-initiation control of transcription exist, as well as a second rate-limiting step that controls conversion of the transcription initiation complex into a transcription elongation complex. Rate-limiting steps of the biochemical pathways are often those that are targeted for regulation. Like the more complex multisubunit transcription systems, multiple steps may exist for control of transcription in human mitochondria. The tools and mechanistic framework presented here will facilitate not only the discovery of mechanisms regulating human mitochondrial transcription but also interrogation of the structure, function, and mechanism of the complexes that are regulated during human mitochondrial transcription. PMID:20351113

Lodeiro, Maria F.; Uchida, Akira U.; Arnold, Jamie J.; Reynolds, Shelley L.; Moustafa, Ibrahim M.; Cameron, Craig E.

2010-01-01

78

[Morphological studies of human gallbladder].  

PubMed

I tried to make it clear three dimensional picture of the smooth muscle of the human gallbladder at first, and found a connection between the smooth muscle and the autonomic nerves in the wall. At autopsy the gallbladder without lesion was collected from 15 males and 7 females died of apoplexy, head injury or myocardial infarction. These material was fixed 10% neural formalin, impregnated into Masson Trichrome for smooth muscle, and modified Golgi method for nerve fivers, embeded in celloidin. I laid a picture after another after tracing serial tangential section of 8 micron by using camera lucida, and made three dimensional picture. In autonomic nerve in the wall three dimensional sections of 100-150 micron were made and observed with light microscope. Three dimensional muscle structure showed monounit structure, having meshwork structure from mucosal area to serous one. It was gratified the condition of the gallbladder contraction to illustrate a series of connection from mucosal aspect to serous one. Many fine nerve fivers were found forming plexuses in the subserous layer, muscular layer and mucosa. There was close relationship between smooth muscle and intramural nerve fibers, which especially distributed into meshwork structure of muscle. I could find morphological relation among the layers, such as three main plexuses. It was suggested that subserous plexus had extrinsic nature. PMID:4087619

Sugai, M

1985-04-01

79

78 FR 76888 - MAP-21 Comprehensive Truck Size and Weight Limits Study Materials  

Federal Register 2010, 2011, 2012, 2013

...MAP-21 Comprehensive Truck Size and Weight Limits Study Materials AGENCY: Federal...MAP-21) Comprehensive Truck Size and Weight Limits Study, which were referenced in...MAP-21 Comprehensive Truck Size and Weight Limits Study and to announce the...

2013-12-19

80

Lesson Study by Secondary Humanities Teachers  

ERIC Educational Resources Information Center

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…

Carpenter, Jeffrey Paul

2009-01-01

81

Breakdown Limit Studies in High-Rate Gaseous Detectors  

NASA Technical Reports Server (NTRS)

We report results from a systematic study of breakdown limits for novel high-rate gaseous detectors: MICROMEGAS, CAT and GEM, together with more conventional devices such as thin-gap parallel-mesh chambers and high-rate wire chambers. It was found that for all these detectors, the maximum achievable pin, before breakdown appears, drops dramatically with incident flux, and is sometimes inversely proportional to it. Further, in the presence of alpha particles, typical of the breakgrounds in high-energy experiments, additional gain drops of 1-2 orders of magnitude were observed for many detectors. It was found that breakdowns at high rates occur through what we have termed an "accumulative" mechanism, which does not seem to have been previously reported in the literature. Results of these studies may help in choosing the optimum detector for given experimental conditions.

Ivaniouchenkov, Yu; Fonte, P.; Peskov, V.; Ramsey, B. D.

1999-01-01

82

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

PubMed

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

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

2011-10-01

83

Exploring the Limits of RF Shimming for High-Field MRI of the Human Head  

PubMed Central

Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high-field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in a transmit array. The adjustment of these drive magnitudes and phases alone to create uniform RF magnetic (B1) fields has been called RF shimming, and has certain limits at every frequency as dictated by possible solutions to Maxwell’s equations. Here we use numerical calculations to explore the limits of RF shimming in the human head. We found that a 16-element array can effectively shim a single slice at frequencies up to 600 MHz and the whole brain at up to 300 MHz, while an 80-element array can shim the whole brain at up to 600 MHz. PMID:16958070

Mao, Weihua; Smith, Michael B.; Collins, Christopher M.

2014-01-01

84

Studies of human mutation rates  

SciTech Connect

The three objectives of the program are: To isolate by the technique of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), proteins of special interest because of the relative mutability of the corresponding gene, establish the identity of the protein, and, for selected proteins, move to a characterization of the corresponding gene; To develop a more efficient approach, based on 2-D PAGE, for the detection of variants in DNA, with special reference to the identification of a variant in a child not present in either parent of the child (i.e., a mutation); and, To continue an effective interface with the genetic studies on the children of atomic bomb survivors in Japan, with reference to both the planning and implementation of new studies at the molecular level. For administrative purposes, the program is subdivided into four sections, each under the direction of one of the four co-PIs; the progress during the past year will be summarized in accordance with this sectional structure. 1 tab.

Neel, J.V.

1991-07-15

85

Fundamental limits of optical critical dimension metrology: a simulation study  

NASA Astrophysics Data System (ADS)

This paper is a comprehensive summary and analysis of a SEMATECH funded project to study the limits of optical critical dimension scatterometry (OCD). The project was focused on two primary elements: 1) the comparison, stability, and validity of industry models and 2) a comprehensive analysis of process stacks to evaluate the ultimate sensitivity and limits of OCD. Modeling methods are a requirement for the interpretation and quantitative analysis of scatterometry data. The four models evaluated show good agreement over a range of targets and geometries for zero order specular reflection as well as higher order diffraction. A number of process stacks and geometries representing semiconductor manufacturing nodes from the 45 nm node to the 18 nm node were simulated using several measurement modalities including angle-resolved scatterometry and spectrally-resolved scatterometry, measuring various combinations of intensity and polarization. It is apparent in the results that large differences are observed between those methods that rely upon unpolarized and single polarization measurements. Using the three parameter fits and assuming that the sensitivity of scatterometry must meet the criterion that the 3? uncertainty in the bottom dimension must be less than 2% of the linewidth, specular scatterometry solutions exist for all but the isolated lines at 18 nm node. Scatterometry does not have sufficient sensitivity for isolated and semi-isolated lines at the 18 nm node unless the measurement uses wavelengths as short as 200 nm or 150 nm and scans over large angle ranges.

Silver, Richard; Germer, Thomas; Attota, Ravikiran; Barnes, Bryan M.; Bunday, Benjamin; Allgair, John; Marx, Egon; Jun, Jay

2007-03-01

86

Placing confidence limits on the molecular age of the human–chimpanzee divergence  

PubMed Central

Molecular clocks have been used to date the divergence of humans and chimpanzees for nearly four decades. Nonetheless, this date and its confidence interval remain to be firmly established. In an effort to generate a genomic view of the human–chimpanzee divergence, we have analyzed 167 nuclear protein-coding genes and built a reliable confidence interval around the calculated time by applying a multifactor bootstrap-resampling approach. Bayesian and maximum likelihood analyses of neutral DNA substitutions show that the human–chimpanzee divergence is close to 20% of the ape–Old World monkey (OWM) divergence. Therefore, the generally accepted range of 23.8–35 millions of years ago for the ape–OWM divergence yields a range of 4.98–7.02 millions of years ago for human–chimpanzee divergence. Thus, the older time estimates for the human–chimpanzee divergence, from molecular and paleontological studies, are unlikely to be correct. For a given the ape–OWM divergence time, the 95% confidence interval of the human–chimpanzee divergence ranges from –12% to 19% of the estimated time. Computer simulations suggest that the 95% confidence intervals obtained by using a multifactor bootstrap-resampling approach contain the true value with >95% probability, whether deviations from the molecular clock are random or correlated among lineages. Analyses revealed that the use of amino acid sequence differences is not optimal for dating human–chimpanzee divergence and that the inclusion of additional genes is unlikely to narrow the confidence interval significantly. We conclude that tests of hypotheses about the timing of human–chimpanzee divergence demand more precise fossil-based calibrations. PMID:16365310

Kumar, Sudhir; Filipski, Alan; Swarna, Vinod; Walker, Alan; Hedges, S. Blair

2005-01-01

87

Circumventing storage limitations in variational data assimilation studies  

SciTech Connect

The aim of data assimilation is to infer the state of a system from a geophysical model and possibly incomplete or nonuniformly distributed spatiotemporal observational data. Used extensively in engineering control theory applications, data assimilation has relatively recently been introduced into meteorological forecasting, natural-resource recovery modeling, and climate dynamics. Variations data assimilation is a promising assimilation technique in which it is assumed that the state of the system is an extrema of a carefully chosen objective function. Provided that an adjoint model is available, the required model gradients can be computed by integrating the model forward and its adjoint backward. the gradients are then used to extremize the cost function with a suitable iterative or conjugate gradient solver. The problem addressed in this study is the explosive growth in both on-line computer memory and remote storage requirements of large-scale assimilation studies. This imposes a severe physical limitation on the size of assimilation studies, even on the largest computers. By using a recursive strategy, a schedule can be constructed that enables the forward/adjoint model runs to be performed in such a way that storage requirements can be traded for longer computational times. This generally applicable strategy enables data assimilation studies on significantly larger domains that would otherwise be possible given particular hardware constraints. The authors show that this tradeoff is indeed viable and that when the schedule is optimized, the storage and computational times grow at most logarithmically.

Restrepo, J.M.; Leaf, G.K. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.; Griewank, A. [Technical Univ. of Dresden (Germany)

1997-07-01

88

Anxieties of communication: the limits of narrative in the medical humanities.  

PubMed

This paper aims to provide an initial response to Angela Woods's endeavour to '(re)ignite critical debates around this topic' in her recent essay 'The limits of narrative: provocations for the medical humanities' (Medical Humanities 2011). Woods's essay challenges the validity of the notion of the narrative self through her discussion and use of Galen Strawson's seminal 'Against narrativity' (2004). To some extent in dialogue with Woods, this article will examine three exploratory concepts connected with the topic. First, it will explore ways in which we might seek to re-place narrative at the centre of the philosophy of good medicine and medical practice by reassessing the role of the narratee in the narrative process. Second, it will reconsider the three alternative forms of expression Woods puts forward as non-narrative--metaphor, phenomenology and photography--as narrative. Finally, and connected to the first two areas of discussion, it will reflect on ways in which narrative might be used to interpret illness and suffering in medical humanities contexts. What I hope to show, in relation to Woods's work on this subject, is that in order to be interpreted (indeed interpretable) the types of non-narrative representation and communication she discusses in fact require a narrative response. We employ narratology to engage with illness experience because narrative is so fundamental to meaning-making that it is not just required, it is an inherent human response to creative outputs we encounter. This is a quite different approach to the question of narrativity in the medical humanities, and it is therefore related to, but not entirely hinged upon, the work that Woods has done, but it is intended to spark further discussion across the emergent discipline. PMID:24869471

McKechnie, Claire Charlotte

2014-12-01

89

Multilocus Genotyping of Human Giardia Isolates Suggests Limited Zoonotic Transmission and Association between Assemblage B and Flatulence in Children  

PubMed Central

Background Giardia intestinalis is one of the most common diarrhea-related parasites in humans, where infection ranges from asymptomatic to acute or chronic disease. G. intestinalis consists of eight genetically distinct genotypes or assemblages, designated A–H, and assemblages A and B can infect humans. Giardiasis has been classified as a possible zoonotic disease but the role of animals in human disease transmission still needs to be proven. We tried to link different assemblages and sub-assemblages of G. intestinalis isolates from Swedish human patients to clinical symptoms and zoonotic transmission. Methodology/Principal Findings Multilocus sequence-based genotyping of 207 human Giardia isolates using three gene loci: ß-giardin, glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) was combined with assemblage-specific tpi PCRs. This analysis identified 73 patients infected with assemblage A, 128 with assemblage B, and six with mixed assemblages A+B. Multilocus genotypes (MLGs) were easily determined for the assemblage A isolates, and most patients with this genotype had apparently been infected through anthroponotic transmission. However, we also found evidence of limited zoonotic transmission of Giardia in Sweden, since a few domestic human infections involved the same assemblage A MLGs previously reported in Swedish cats and ruminants. Assemblage B was detected more frequently than assemblage A and it was also more common in patients with suspected treatment failure. However, a large genetic variability made determination of assemblage B MLGs problematic. Correlation between symptoms and assemblages was found only for flatulence, which was significantly more common in children less than six years of age infected with assemblage B. Conclusions/Significance This study shows that certain assemblage A subtypes are potentially zoonotic and that flatulence is connected to assemblage B infections in young children. Determination of MLGs from assemblages A and B can be a valuable tool in outbreak situations and to help identify possible zoonotic transmission. PMID:21829745

Lebbad, Marianne; Petersson, Ingvor; Karlsson, Lillemor; Botero-Kleiven, Silvia; Andersson, Jan O.; Svenungsson, Bo; Svärd, Staffan G.

2011-01-01

90

CCR6 Functions as a New Coreceptor for Limited Primary Human and Simian Immunodeficiency Viruses  

PubMed Central

More than 12 chemokine receptors (CKRs) have been identified as coreceptors for the entry of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2), and simian immunodeficiency viruses (SIVs) into target cells. The expression of CC chemokine receptor 6 (CCR6) on Th17 cells and regulatory T cells make the host cells vulnerable to HIV/SIV infection preferentially. However, only limited information is available concerning the specific role of CCR6 in HIV/SIV infection. We examined CCR6 as a coreceptor candidate in this study using NP-2 cell line-based in-vitro studies. Normally, CD4-transduced cell line, NP-2/CD4, is strictly resistant to all HIV/SIV infection. When CCR6 was transduced there, the resultant NP-2/CD4/CCR6 cells became susceptible to HIV-1HAN2, HIV-2MIR and SIVsmE660, indicating coreceptor roles of CCR6. Viral antigens in infected cells were detected by IFA and confirmed by detection of proviral DNA. Infection-induced syncytia in NP-2/CD4/CCR6 cells were detected by Giemsa staining. Amount of virus release through CCR6 has been detected by RT assay in spent culture medium. Sequence analysis of proviral DNA showed two common amino acid substitutions in the C2 envelope region of HIV-2MIR clones propagated through NP-2/CD4/CCR6 cells. Conversely, CCR6-origin SIVsmE660 clones resulted two amino acid changes in the V1 region and one change in the C2 region. The substitutions in the C2 region for HIV-2MIR and the V1 region of SIVsmE660 may confer selection advantage for CCR6-use. Together, the results describe CCR6 as an independent coreceptor for HIV and SIV in strain-specific manner. The alteration of CCR6 uses by viruses may influence the susceptibility of CD4+ CCR6+ T-cells and dendritic cell subsets in vivo and therefore, is important for viral pathogenesis in establishing latent infections, trafficking, and transmission. However, clinical relevance of CCR6 as coreceptor in HIV/SIV infections should be investigated further. PMID:24009735

Islam, Salequl; Shimizu, Nobuaki; Hoque, Sheikh Ariful; Jinno-Oue, Atsushi; Tanaka, Atsushi; Hoshino, Hiroo

2013-01-01

91

From Oxford to Hawaii ecophysiological barriers limit human progression in ten sport monuments.  

PubMed

In order to understand the determinants and trends of human performance evolution, we analyzed ten outdoor events among the oldest and most popular in sports history. Best performances of the Oxford-Cambridge boat race (since 1836), the channel crossing in swimming (1875), the hour cycling record (1893), the Elfstedentocht speed skating race (1909), the cross country ski Vasaloppet (1922), the speed ski record (1930), the Streif down-hill in Kitzbühel (1947), the eastward and westward sailing transatlantic records (1960) and the triathlon Hawaii ironman (1978) all follow a similar evolutive pattern, best described through a piecewise exponential decaying model (r(2) = 0.95+/-0.07). The oldest events present highest progression curvature during their early phase. Performance asymptotic limits predicted from the model may be achieved in fourty years (2049+/-32 y). Prolonged progression may be anticipated in disciplines which further rely on technology such as sailing and cycling. Human progression in outdoor sports tends to asymptotic limits depending on physiological and environmental parameters and may temporarily benefit from further technological progresses. PMID:18985149

Desgorces, François-Denis; Berthelot, Geoffroy; El Helou, Nour; Thibault, Valérie; Guillaume, Marion; Tafflet, Muriel; Hermine, Olivier; Toussaint, Jean-François

2008-01-01

92

Technical and ethical limitations in making human monoclonal antibodies (an overview).  

PubMed

In the broadest sense there are no longer any technical limitations to making human mAbs. Biological issues involving the type and nature of either a synthetic or a natural antibody, advantages of various B cell immunological compartments, and various assays needed to qualitate and quantitate mAbs have essentially been solved. If the target antigen is known then procedures to optimize antibody development can be readily planned out and implemented. When the antigen or target is unknown and specificity is the driving force in generating a human mAb then considerations about the nature and location of the B cell making the sought after antibody become important. And, therefore, the person the B cell is obtained from can be an ethical challenge and a limitation. For the sources of B cells special considerations must be taken to insure the anonymity and privacy of the patient. In many cases informed consent is adequate for antibody development as well as using discarded tissues. After the antibody has been generated then manufacturing technical issues become important that greatly depend upon the amounts of mAb required. For kilogram quantities then special considerations for manufacturing that include FDA guidelines will be necessary. PMID:24037834

Glassy, Mark C; Gupta, Rishab

2014-01-01

93

Using electroencephalography to study functional coupling between cortical activity and electromyograms during voluntary contractions in humans  

Microsoft Academic Search

Previous studies of neuronal oscillations in sensorimotor cortex in humans and primates have observed rhythmic 15–30 Hz activity, which is correlated with motor output. In humans, this work has been limited to magnetic recordings. In the present study we investigate if similar results can be obtained using electroencephalography (EEG). EEG recordings were made from over the sensorimotor cortex of five

David M Halliday; Bernard A Conway; Simon F Farmer; Jay R. Rosenberg

1998-01-01

94

Potential and Limitation of HLA-Based Banking of Human Pluripotent Stem Cells for Cell Therapy  

PubMed Central

Great hopes have been placed on human pluripotent stem (hPS) cells for therapy. Tissues or organs derived from hPS cells could be the best solution to cure many different human diseases, especially those who do not respond to standard medication or drugs, such as neurodegenerative diseases, heart failure, or diabetes. The origin of hPS is critical and the idea of creating a bank of well-characterized hPS cells has emerged, like the one that already exists for cord blood. However, the main obstacle in transplantation is the rejection of tissues or organ by the receiver, due to the three main immunological barriers: the human leukocyte antigen (HLA), the ABO blood group, and minor antigens. The problem could be circumvented by using autologous stem cells, like induced pluripotent stem (iPS) cells, derived directly from the patient. But iPS cells have limitations, especially regarding the disease of the recipient and possible difficulties to handle or prepare autologous iPS cells. Finally, reaching standards of good clinical or manufacturing practices could be challenging. That is why well-characterized and universal hPS cells could be a better solution. In this review, we will discuss the interest and the feasibility to establish hPS cells bank, as well as some economics and ethical issues. PMID:25126584

Villard, Jean

2014-01-01

95

Collaborative study to establish human immunoglobulin BRP batch 3 and human immunoglobulin (molecular size) BRP batch 1.  

PubMed

A study was carried out by the European Directorate for the Quality of Medicines (EDQM) as part of the joint Biological Standardisation Programme of the Council of Europe and the European Commission with the aim to establish replacement batches of the European Pharmacopoeia (Ph. Eur.) human immunoglobulin Biological Reference Preparation (BRP) batch 2. Twenty-eight laboratories participated in this study. The suitability of the candidate reference preparations to serve as working references in the tests for distribution of the molecular size, anticomplementary activity and Fc function, in accordance with the specifications of the Ph. Eur. monographs Human normal immunoglobulin for intravenous administration (0918), Human normal immunoglobulin (0338) and Anti-T lymphocyte immunoglobulin for human use, animal (1928) was demonstrated. The candidates were therefore established as human immunoglobulin BRP batch 3 and Human immunoglobulin (molecular size) BRP batch 1. The prescribed use of the latter BRP is limited to the test for distribution of molecular size. PMID:17270130

Sandberg, E; Daas, A; Behr-Gross, M-E

2006-11-01

96

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

PubMed Central

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

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

2008-01-01

97

Human Transportation System (HTS) study, volume 1  

NASA Technical Reports Server (NTRS)

Work completed under the Human Transportation System Study is summarized. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems as well as proposed systems to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are the following: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

Lance, N.; Geyer, M. S.; Gaunce, M. T.

1993-01-01

98

Human Transportation System (HTS) study: Executive summary  

NASA Technical Reports Server (NTRS)

Work completed under the Human Transportation System Study is summarized. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems as well as proposed systems to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are the following: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

Lance, N.; Geyer, M. S.; Gaunce, M. T.

1993-01-01

99

Genomic approaches to studying the human microbiota  

PubMed Central

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

Weinstock, George M.

2013-01-01

100

An immunosufficient murine model for the study of human islets.  

PubMed

For the sake of therapy of diabetes, it is critical to understand human beta cell function in detail in health and disease. Current studies of human beta cell physiology in vivo are mostly limited to immunodeficient mouse models, which possess significant technical limitations. This study aimed to create a new model for the study of human islets through induction of transplant tolerance in immunosufficient mice. B6 diabetic mice were transplanted with human islets and treated with anti-CD45RB. To assess whether anti-CD45RB-induced transplant tolerance requires B cells, B6 recipients received additional anti-CD20 or B6?MT-/- mice were used. For some anti-CD45RB-treated B6?MT-/- mice, additional anti-CD25 mAb was applied at the early or late stage post-transplant. Immunohistology was performed to show the Foxp3 cells in grafted anti-CD45RB/anti-CD20-treated Foxp3-GFP B6 mice. The results showed that anti-CD45RB alone allowed indefinite graft survival in 26.6% of B6 mice, however 100% of xenografts were accepted in mice treated simultaneously with anti-CD20, and 88.9% of xenografts accepted in anti-CD45RB-treated ?MT-/- mice. These ?MT-/- mice accepted the islets from another human donor but rejected the islets from baboon. Additional administration of anti-CD25 mAb at the time of transplantation resulted in 100% rejection, whereas 40% of grafts were rejected while the antibody was administrated at days 60 post-transplant. Immunohistologic examination showed Foxp3+ cells accumulated around grafts. We conclude that induction of tolerance to human islets in an immunosufficient mouse model could be generated by targeting murine CD45RB and CD20. This new system will facilitate study of human islets and accelerate the dissection of the critical mechanisms underlying islet health in human disease. PMID:25041432

Zhao, Gaoping; Moore, Daniel J; Kim, James I; Lee, Kang Mi; O'Connor, Matthew; Yang, Maozhu; Marshall, Andrew F; Lei, Ji; Schuetz, Christian; Markmann, James F; Deng, Shaoping

2014-11-01

101

Racism and human genome diversity research: the ethical limits of "population thinking".  

PubMed

This paper questions the prevailing historical understanding that scientific racism "retreated" in the 1950s when anthropology adopted the concepts and methods of population genetics and race was recognized to be a social construct and replaced by the concept of population. More accurately, a "populational" concept of race was substituted for a "typological one"--this is demonstrated by looking at the work of Theodosius Dobzhansky circa 1950. The potential for contemporary research in human population genetics to contribute to racism needs to be considered with respect to the ability of the typological-population distinction to arbitrate boundaries between racist society and nonracist, even anti-racist, science. I point out some ethical limits of "population thinking" in doing so. PMID:15948338

Gannett, L

2001-01-01

102

Selenium neurotoxicity in humans: bridging laboratory and epidemiologic studies.  

PubMed

Selenium is a metalloid of considerable interest in the human from both a toxicological and a nutritional perspective, with a very narrow safe range of intake. Acute selenium intoxication is followed by adverse effects on the nervous system with special clinical relevance, while the neurotoxicity of long-term overexposure is less characterized and recognized. We aimed to address this issue from a public health perspective, focusing on both laboratory studies and the few epidemiologic human studies available, with emphasis on their methodological strengths and limitations. The frequently overlooked differences in toxicity and biological activity of selenium compounds are also outlined. In addition to lethargy, dizziness, motor weakness and paresthesias, an excess risk of amyotrophic lateral sclerosis is the effect on the nervous system which has been more consistently associated with chronic low-level selenium overexposure, particularly to its inorganic compounds. Additional research efforts are needed to better elucidate the neurotoxic effects exerted by selenium overexposure. PMID:24269718

Vinceti, Marco; Mandrioli, Jessica; Borella, Paola; Michalke, Bernhard; Tsatsakis, Aristidis; Finkelstein, Yoram

2014-10-15

103

Expanding the limits of human blood metabolite quantitation using NMR spectroscopy.  

PubMed

A current challenge in metabolomics is the reliable quantitation of many metabolites. Limited resolution and sensitivity combined with the challenges associated with unknown metabolite identification have restricted both the number and the quantitative accuracy of blood metabolites. Focused on alleviating this bottleneck in NMR-based metabolomics, investigations of pooled human serum combining an array of 1D/2D NMR experiments at 800 MHz, database searches, and spiking with authentic compounds enabled the identification of 67 blood metabolites. Many of these (?1/3) are new compared with those reported previously as a part of the Human Serum Metabolome Database. In addition, considering both the high reproducibility and quantitative nature of NMR as well as the sensitivity of NMR chemical shifts to altered sample conditions, experimental protocols and comprehensive peak annotations are provided here as a guide for identification and quantitation of the new pool of blood metabolites for routine applications. Further, investigations focused on the evaluation of quantitation using organic solvents revealed a surprisingly poor performance for protein precipitation using acetonitrile. One-third of the detected metabolites were attenuated by 10-67% compared with methanol precipitation at the same solvent-to-serum ratio of 2:1 (v/v). Nearly 2/3 of the metabolites were further attenuated by up to 65% upon increasing the acetonitrile-to-serum ratio to 4:1 (v/v). These results, combined with the newly established identity for many unknown metabolites in the NMR spectrum, offer new avenues for human serum/plasma-based metabolomics. Further, the ability to quantitatively evaluate nearly 70 blood metabolites that represent numerous classes, including amino acids, organic acids, carbohydrates, and heterocyclic compounds, using a simple and highly reproducible analytical method such as NMR may potentially guide the evaluation of samples for analysis using mass spectrometry. PMID:25485990

Nagana Gowda, G A; Gowda, Yashas N; Raftery, Daniel

2015-01-01

104

Limited terminal transferase in human DNA polymerase ? defines the required balance between accuracy and efficiency in NHEJ  

PubMed Central

DNA polymerase mu (Pol?) is a family X member implicated in DNA repair, with template-directed and terminal transferase (template-independent) activities. It has been proposed that the terminal transferase activity of Pol? can be specifically required during non-homologous end joining (NHEJ) to create or increase complementarity of DNA ends. By site-directed mutagenesis in human Pol?, we have identified a specific DNA ligand residue (Arg387) that is responsible for its limited terminal transferase activity compared to that of human TdT, its closest homologue (42% amino acid identity). Pol? mutant R387K (mimicking TdT) displayed a large increase in terminal transferase activity, but a weakened interaction with ssDNA. That paradox can be explained by the regulatory role of Arg387 in the translocation of the primer from a non-productive E:DNA complex to a productive E:DNA:dNTP complex in the absence of a templating base, which is probably the rate limiting step during template-independent synthesis. Further, we show that the Pol? switch from terminal transferase to templated insertions in NHEJ reactions is triggered by recognition of a 5?-P at a second DNA end, whose 3?-protrusion could provide a templating base to facilitate such a special “pre-catalytic translocation step.” These studies shed light on the mechanism by which a rate-limited terminal transferase activity in Pol? could regulate the balance between accuracy and necessary efficiency, providing some variability during NHEJ. PMID:19805281

Andrade, Paula; Martín, María José; Juárez, Raquel; López de Saro, Francisco; Blanco, Luis

2009-01-01

105

40 CFR 26.1606 - Human Studies Review Board review of proposed human research.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false Human Studies Review Board review of proposed human research. 26.1606 Section 26.1606...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and...

2013-07-01

106

40 CFR 26.1607 - Human Studies Review Board review of completed human research.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 2013-07-01 false Human Studies Review Board review of completed human research. 26.1607 Section 26.1607...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and...

2013-07-01

107

40 CFR 26.1607 - Human Studies Review Board review of completed human research.  

... 2014-07-01 2014-07-01 false Human Studies Review Board review of completed human research. 26.1607 Section 26.1607...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and...

2014-07-01

108

40 CFR 26.1606 - Human Studies Review Board review of proposed human research.  

... 2014-07-01 2014-07-01 false Human Studies Review Board review of proposed human research. 26.1606 Section 26.1606...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and...

2014-07-01

109

The Rational Choice Approach to Human Studies: A Reexamination  

Microsoft Academic Search

This article reexamines the rational choice or economic approach to human studies. Its adherents claim that its extension beyond its original domain to “all human behavior” can finally lead to integration of the human studies, especially social theory, and thus their elevation from what they see as a chaotic state. Specifically, they propose grounding human studies on the premise that

Milan Zafirovski

2003-01-01

110

Energy Aware Computing through Probabilistic Switching: A Study of Limits  

Microsoft Academic Search

The mathematical technique of randomization yielding probabilistic algorithms is shown, for the first time, through a physical interpretation based on statistical thermodynamics, to be a basis for energy savings in computing. Concretely, at the fundamental limit, it is shown that the energy needed to compute a single probabilistic bit or PBIT is proportional to the probability p of computing a

Krishna V. Palem

2005-01-01

111

The neural basis of temporal individuation and its capacity limits in the human brain  

PubMed Central

Individuation refers to individuals' use of spatial and temporal properties to register an object as a distinct perceptual event relative to other stimuli. Although behavioral studies have examined both spatial and temporal individuation, neuroimaging investigations of individuation have been restricted to the spatial domain and at relatively late stages of information processing. In this study we used univariate and multivoxel pattern analyses of functional magnetic resonance imaging data to identify brain regions involved in individuating temporally distinct visual items and the neural consequences that arise when this process reaches its capacity limit (repetition blindness, RB). First, we found that regional patterns of blood oxygen level-dependent activity in a large group of brain regions involved in “lower-level” perceptual and “higher-level” attentional/executive processing discriminated between instances where repeated and nonrepeated stimuli were successfully individuated, conditions that placed differential demands on temporal individuation. These results could not be attributed to repetition suppression, stimulus or response factors, task difficulty, regional activation differences, other capacity-limited processes, or artifacts in the data or analyses. Consistent with the global workplace model of consciousness, this finding suggests that temporal individuation is supported by a distributed set of brain regions, rather than a single neural correlate. Second, conditions that reflect the capacity limit of individuation (instances of RB) modulated the amplitude, rather than spatial pattern, of activity in the left hemisphere premotor cortex. This finding could not be attributed to response conflict/ambiguity and likely reflects a candidate brain region underlying the capacity-limited process that gives rise to RB. PMID:24198320

Tamber-Rosenau, Benjamin J.; Dux, Paul E.

2013-01-01

112

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

NASA Astrophysics Data System (ADS)

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.

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

113

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

SciTech Connect

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 establishment of nuclear medicine, radiation therapy, and radiological protection standards, the underlying ethical basis for a small number of these studies is being questioned. A thorough analysis of these studies and their ethical basis is beyond the scope of this article. Rather, in order to quickly provide the health physics community with some of the available resources in the open literature, a list of bibliographic citations of the 47 studies primarily funded by the Atomic Energy Commission (AEC) and other predecessors of the Department of Energy is presented and briefly summarized. A classification scheme for the human radiation experiments is also developed.

Samei, E.; Kearfott, K.J. [Univ. of Michigan, Ann Arbor, MI (United States)

1995-12-01

114

The Viral E8^E2C Repressor Limits Productive Replication of Human Papillomavirus 16  

PubMed Central

Productive replication of human papillomavirus type 16 (HPV16) occurs only in differentiated keratinocyte cells. In addition to the viral E2 activator protein, HPV16 and related HPV types express transcripts coding for an E8^E2C fusion protein, which limits genome replication in undifferentiated keratinocytes. To address E8^E2C's role in productive replication of HPV16, stable keratinocyte cell lines containing wild-type (wt), E8^E2C knockout (E8?), or E8 KWK mutant (mt) genomes, in which conserved E8 residues were inactivated, were established. Copy numbers of E8? and E8 KWK mt genomes and amounts of early and late viral transcripts were greatly increased compared to those for the wt in undifferentiated keratinocytes, suggesting that HPV16 E8^E2C activities are highly dependent upon the E8 part. Upon differentiation in organotypic cultures, E8 mt genomes displayed higher early viral transcript levels, but no changes in cellular differentiation or virus-induced cellular DNA replication in suprabasal cells were observed. E8 mt genomes were amplified to higher copy numbers and showed increased L1 transcripts compared to wt genomes. Furthermore, the number of cells expressing the viral late protein E4 or L1 or amplifying viral genomes was greatly increased in E8 mt cell lines. In wild-type cells, E8^E2C transcript levels did not decrease by differentiation. Our data indicate that the E8^E2C repressor limits viral transcription and replication throughout the complete life cycle of HPV16. PMID:24198405

Straub, Elke; Dreer, Marcel; Fertey, Jasmin; Iftner, Thomas

2014-01-01

115

Roadmap: Physical Education Human Movement Studies Bachelor of Science  

E-print Network

] ATTR 25057 Human Anatomy and Physiology I or EXSC 25057 Human Anatomy and Physiology I 3 See note 1Roadmap: 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

Sheridan, Scott

116

Human Transportation System (HTS) study, volume 2  

NASA Technical Reports Server (NTRS)

This report summarizes work completed under the Human Transportation System Study. This study was conducted by the New Initiatives Office at JSC with the technical support of Boeing, General Dynamics, Lockheed, McDonnell-Douglas, Martin Marietta, and Rockwell. The study was designed to generate information on determining the appropriate path to follow for new system development to meet the Nation's space transportation needs. The study evaluates 18 transportation architecture options using a parametric set of mission requirements. These options include use of current systems (e.g., Shuttle, Titan, etc. ) as well as proposed systems (e.g., PLS, Single-Stage-to-Orbit, etc.) to assess the impact of various considerations, such as the cost of alternate access, or the benefit of separating people and cargo. The architecture options are compared to each other with six measurable evaluation criteria or attributes. They are: funding profile, human safety, probability of mission success, architecture cost risk, launch schedule confidence, and environmental impact. Values for these attributes are presented for the architecture options, with pertinent conclusions and recommendations.

Lance, N.; Geyer, M. S.; Gaunce, M. T.

1993-01-01

117

Bioavailability of tocotrienols: evidence in human studies  

PubMed Central

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

2014-01-01

118

Trans locus inhibitors limit concomitant polysaccharide synthesis in the human gut symbiont Bacteroides fragilis  

PubMed Central

Bacteroides is an abundant genus of bacteria of the human intestinal microbiota. Bacteroides species synthesize a large number of capsular polysaccharides (PS), a biological property not shared with closely related oral species, suggesting importance for intestinal survival. Bacteroides fragilis, for example, synthesizes eight capsular polysaccharides per strain, each of which phase varies via inversion of the promoters located upstream of seven of the eight polysaccharide biosynthesis operons. In a single cell, many of these polysaccharide loci promoters can be simultaneously oriented on for transcription of the downstream biosynthesis operons. Here, we demonstrate that despite the promoter orientations, concomitant transcription of multiple polysaccharide loci within a cell is inhibited. The proteins encoded by the second gene of each of these eight loci, collectively designated the UpxZ proteins, inhibit the synthesis of heterologous polysaccharides. These unique proteins interfere with the ability of UpxY proteins encoded by other polysaccharide loci to function in transcriptional antitermination of their respective operon. The eight UpxZs have different inhibitory spectra, thus establishing a hierarchical regulatory network for polysaccharide synthesis. Limitation of concurrent polysaccharide synthesis strongly suggests that these bacteria evolved this property as an evasion-type mechanism to avoid killing by polysaccharide-targeting factors in the ecosystem. PMID:20547868

Chatzidaki-Livanis, Maria; Comstock, Laurie E.

2010-01-01

119

Structural Studies of Human Pyruvate Dehydrogenase  

NASA Technical Reports Server (NTRS)

Human pyruvate dehydrogenase (E1) catalyzes the irreversible decarboxylation of pyruvate in the presence of Mg(2+) and thiamin pyrophosphate (TPP) followed by the rate-limiting reductive acetylation of the lipoyl moiety linked to dihydrolipoamide acetyltransferase. The three-dimensional structure of human E1 is elucidated using the methods of macromolecular X-ray crystallography. The structure is an alpha, alpha', beta and beta' tetramer with the protein units being in the tetrahedral arrangement. Each 361-residue alpha-subunit and 329-residue beta-subunit is composed of a beta-sheet core surrounded by alpha-helical domains. Each subunit is in extensive contact with all the three subunits involving TPP and magnesium cofactors, and potassium ions. The two binding sites for TPP are at the alpha-beta' and alpha'-beta interfaces, each involving a magnesium ion and Phe6l, His63, Tyr89, and Met200 from the alpha-subunit (or alpha'-subunit), and Met81 Phe85, His128 from the beta-subunit (or beta'-subunit). K+ ions are nestled between two beta-sheets and the end of an alpha-helix in each beta-subunit, where they are coordinated by four carbonyl oxygen groups from Ile12, Ala160, Asp163, and Asnl65, and a water molecule. The catalytic C2 carbon of thiazolium ring in this structure forms a 3.2 A contact with a water molecule involved in a series of H-bonds with other water molecules, and indirectly with amino acids including those involved in the catalysis and regulation of the enzyme.

Ciszak, Ewa; Korotchkina, Lioubov G.; Dominiak, Paulina; Sidhu, Sukhdeep; Patel, Mulchand S.; Curreri, Peter A. (Technical Monitor)

2002-01-01

120

Limited forward trafficking of connexin 43 reduces cell-cell coupling in stressed human and mouse myocardium.  

PubMed

Gap junctions form electrical conduits between adjacent myocardial cells, permitting rapid spatial passage of the excitation current essential to each heartbeat. Arrhythmogenic decreases in gap junction coupling are a characteristic of stressed, failing, and aging myocardium, but the mechanisms of decreased coupling are poorly understood. We previously found that microtubules bearing gap junction hemichannels (connexons) can deliver their cargo directly to adherens junctions. The specificity of this delivery requires the microtubule plus-end tracking protein EB1. We performed this study to investigate the hypothesis that the oxidative stress that accompanies acute and chronic ischemic disease perturbs connexon forward trafficking. We found that EB1 was displaced in ischemic human hearts, stressed mouse hearts, and isolated cells subjected to oxidative stress. As a result, we observed limited microtubule interaction with adherens junctions at intercalated discs and reduced connexon delivery and gap junction coupling. A point mutation within the tubulin-binding domain of EB1 reproduced EB1 displacement and diminished connexon delivery, confirming that EB1 displacement can limit gap junction coupling. In zebrafish hearts, oxidative stress also reduced the membrane localization of connexin and slowed the spatial spread of excitation. We anticipate that protecting the microtubule-based forward delivery apparatus of connexons could improve cell-cell coupling and reduce ischemia-related cardiac arrhythmias. PMID:20038810

Smyth, James W; Hong, Ting-Ting; Gao, Danchen; Vogan, Jacob M; Jensen, Brian C; Fong, Tina S; Simpson, Paul C; Stainier, Didier Y R; Chi, Neil C; Shaw, Robin M

2010-01-01

121

Sorption studies of human keratinized tissues  

NASA Astrophysics Data System (ADS)

Water content is known to be the most important single parameter for keratinized tissue to remain its vital functions. In that sense, a general knowledge of the water binding properties is of great interest, and a reliable measurement setup must be found. Also, revealing the sorption properties of human keratinized tissues is vital towards a calibration of susceptance based skin hydration measurements that already is an important diagnostic tool in clinical dermatology, and we will see that any hysteresis will complicate such a calibration further. In this study we investigated the sorption properties of keratinized tissues such as human epidermal stratum corneum (SC), hair and nail. The study was performed under controlled environmental conditions with a dynamic vapor sorption (DVS) instrument, and the water uptake of the keratinized test samples was measured as the relative humidity in the ambient air was altered step-wisely. In this study, vital and characteristic water sorption properties such as the isotherm, relative water uptake, and hysteresis were investigated and will be discussed.

Johnsen, G. K.; Martinsen, Ř. G.; Grimnes, Sverre

2010-04-01

122

Preliminary neutron crystallographic study of human transthyretin  

PubMed Central

Preliminary studies of perdeuterated crystals of human transthyretin (TTR) have been carried out using the LADI-III and D19 diffractometers at the Institut Laue–Langevin in Grenoble. The results demonstrate the feasibility of a full crystallographic analysis to a resolution of 2.0?Ĺ using Laue diffraction and also illustrate the potential of using monochromatic instruments such as D19 for higher resolution studies where larger crystals having smaller unit cells are available. This study will yield important information on hydrogen bonding, amino-acid protonation states and hydration in the protein. Such information will be of general interest for an understanding of the factors that stabilize/destabilize TTR and for the design of ligands that may be used to counter TTR amyloid fibrillogenesis. PMID:22102249

Haupt, Melina; Blakeley, Matthew P.; Teixeira, Susana C. M.; Mason, Sax A.; Mitchell, Edward P.; Cooper, Jonathan B.; Forsyth, V. Trevor

2011-01-01

123

Identification of host miRNAs that may limit human rhinovirus replication  

PubMed Central

AIM: To test whether the replication of human rhinovirus (HRV) is regulated by microRNAs in human bronchial epithelial cells. METHODS: For the present study, the human cell line BEAS-2B (derived from normal human bronchial epithelial cells) was adopted. DICER knock-down, by siRNA transfection in BEAS-2B cells, was performed in order to inhibit microRNA maturation globally. Alternatively, antisense oligonucleotides (anti-miRs) were transfected to inhibit the activity of specific microRNAs. Cells were infected with HRV-1B. Viral replication was assessed by measuring the genomic viral RNA by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Association between microRNA-induced-silencing-complex and viral RNA was detected by Ago2 co-immunoprecipitation followed by RT-qPCR. Targetscan v.6 was used to predict microRNA target sites on several HRV strains. RESULTS: Here, we show that microRNAs affect replication of HRV-1B. DICER knock-down significantly reduced the expression of mature microRNAs in a bronchial epithelial cell line (BEAS-2B) and in turn, increased the synthesis of HRV-1B RNA. Additionally, HRV-1B RNA co-immunoprecipitated with argonaute 2 protein, an important effector for microRNA activity suggesting that microRNAs bind to viral RNA during infection. In order to identify specific microRNAs involved in this interaction, we employed bioinformatics analysis, and selected a group of microRNAs that have been reported to be under-expressed in asthmatic bronchial epithelial cells and were predicted to target different strains of rhinoviruses (HRV-1B, -16, -14, -27). Our results suggest that, out of this group of microRNAs, miR-128 and miR-155 contribute to the innate defense against HRV-1B: transfection of specific anti-miRs increased viral replication, as anticipated in-silico. CONCLUSION: Taken together, our results suggest that pathological changes in microRNA expression, as already reported for asthma or chronic obstructive pulmonary disease have the potential to affect Rhinovirus replication and therefore may play a role in virus-induced exacerbations. PMID:25426267

Bondanese, Victor Paky; Francisco-Garcia, Ana; Bedke, Nicole; Davies, Donna E; Sanchez-Elsner, Tilman

2014-01-01

124

MONOAMINE OXIDASE: RADIOTRACER DEVELOPMENT AND HUMAN STUDIES.  

SciTech Connect

PET is uniquely capable of providing information on biochemical transformations in the living human body. Although most of the studies of monoamine oxidase (MAO) have focused on measurements in the brain, the role of peripheral MAO as a phase 1 enzyme for the metabolism of drugs and xenobiotics is gaining attention (Strolin Benedetti and Tipton, 1998; Castagnoli et al., 1997.). MAO is well suited for this role because its concentration in organs such as kidneys, liver and digestive organs is high sometimes exceeding that in the brain. Knowledge of the distribution of the MAO subtypes within different organs and different cells is important in determining which substrates (and which drugs and xenobiotics) have access to which MAO subtypes. The highly variable subtype distribution with different species makes human studies even more important. In addition, the deleterious side effects of combining MAO inhibitors with other drugs and with foodstuffs makes it important to know the MAO inhibitory potency of different drugs both in the brain and in peripheral organs (Ulus et al., 2000). Clearly PET can play a role in answering these questions, in drug research and development and in discovering some of the factors which contribute to the highly variable MAO levels in different individuals.

FOWLER,J.S.; LOGAN,J.; VOLKOW,N.D.; WANG,G.J.; MACGREGOR,R.R.; DING,Y.S.

2000-09-28

125

Gene regulation of UDP-galactose synthesis and transport: Potential rate limiting processes in initiation of milk production in humans  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lactose synthesis is believed to be rate-limiting for milk production. However, understanding the molecular events controlling lactose synthesis in humans is still rudimentary. We have utilized our established model of the RNA isolated from breast milk fat globule from 7 healthy exclusively breastfe...

126

Factors which Limit the Value of Additional Redundancy in Human Rated Launch Vehicle Systems  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) has embarked on an ambitious program to return humans to the moon and beyond. As NASA moves forward in the development and design of new launch vehicles for future space exploration, it must fully consider the implications that rule-based requirements of redundancy or fault tolerance have on system reliability/risk. These considerations include common cause failure, increased system complexity, combined serial and parallel configurations, and the impact of design features implemented to control premature activation. These factors and others must be considered in trade studies to support design decisions that balance safety, reliability, performance and system complexity to achieve a relatively simple, operable system that provides the safest and most reliable system within the specified performance requirements. This paper describes conditions under which additional functional redundancy can impede improved system reliability. Examples from current NASA programs including the Ares I Upper Stage will be shown.

Anderson, Joel M.; Stott, James E.; Ring, Robert W.; Hatfield, Spencer; Kaltz, Gregory M.

2008-01-01

127

Human Development Impacts of Migration: South Africa Case Study  

Microsoft Academic Search

Controls on human mobility and efforts to undermine them continue to shape South Africa’s politics, economy, and society. Despite the need for improved policy responses to human mobility, reform is hindered by lack of capacity, misinformation, and anti-migrant sentiments within and outside of government. This report outlines these trends and tensions by providing a broad overview of the limited demographic

Loren B. Landau; Aurelia Wa Kabwe-Segatti

2009-01-01

128

Study on Optical Filter Heating in Background Limited Detector Experiments  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

129

Dietary flavonoids and cancer risk: evidence from human population studies.  

PubMed

High dietary intake of fruits and vegetables is consistently associated with a reduced risk of common human cancers, including cancers of the lung, breast, prostate, and colon. It is unknown which bioactive compound or compounds in plant foods provide the chemoprotective effects. One class of compounds currently under investigation is flavonoids, a large group of compounds with similar structure, consisting of two phenolic benzene rings linked to a heterocyclic pyran or pyrone. Although there are numerous in vitro and animal model data suggesting that flavonoids influence important cellular and molecular mechanisms related to carcinogenesis, such as cell cycle control and apoptosis, there are limited data from human population studies. This article reviews data from four cohort studies and six case-control studies, which have examined associations of flavonoid intake with cancer risk. There is consistent evidence from these studies that flavonoids, especially quercetin, may reduce the risk of lung cancer. Further research using new dietary databases for food flavonoid content is needed to confirm these findings before specific public health recommendations about flavonoids can be formulated. PMID:15572291

Neuhouser, Marian L

2004-01-01

130

http://www.kyoto-u.ac.jp/ja Integrated Human Studies Integrated Human Studies  

E-print Network

, Electronic Science and Engineering, Material Chemistry, Energy and Hydrocarbon Chemistry, Molecular, Fundamental Energy Science, Energy Conversion Science, Energy Science and Technology Asian and African Area Engineering 2 2, 7 2, 8 2, 9, 10 Agriculture Human and Environmental Studies Energy Science 2 7 2 7 2 2 Asian

Takada, Shoji

131

Human Rights and the Limitations of Releasing Subaltern Voices in a Post-Apartheid South Africa  

Microsoft Academic Search

Postcoloniality and the achievement of human rights in South Africa mark the transition to a post-apartheid society. The denial\\u000a and violation of human rights of particularly “black”1 South Africans under apartheid has placed the provision and protection of human rights centrally in the defi nition of a\\u000a post-apartheid, “new” South Africa. Policy and administrative changes in education underscore this. The

Nazir Carrim

132

Metabolomic studies of human gastric cancer: review.  

PubMed

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

Jayavelu, Naresh Doni; Bar, Nadav S

2014-07-01

133

Metabolomic studies of human gastric cancer: Review  

PubMed Central

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

Jayavelu, Naresh Doni; Bar, Nadav S

2014-01-01

134

Overcoming phytoremediation limitations. A case study of Hg contaminated soil  

NASA Astrophysics Data System (ADS)

Phytoremediation is a broad term that comprises several technologies to clean up water and soil. Despite the numerous articles appearing in scientific journals, very few field applications of phytoextraction have been successfully realized. The research here reported on Phytoextraction, the use the plant to "extract" metals from contaminated soil, is focused on implementations to overcome two main drawbacks: the survival of plants in unfavorable environmental conditions (contaminant toxicity, low fertility, etc.) and the often lengthy time it takes to reduce contaminants to the requested level. Moreover, to overcome the imbalance between the technology's potential and its drawbacks, there is growing interest in the use of plants to reduce only the fraction that is the most hazardous to the environment and human health, that is to target the bioavailable fractions of metals in soil. Bioavailable Contaminant Stripping (BCS) would be a remediation approach focused to remove the bioavailable metal fractions. BCS have been used in a mercury contaminated soil from Italian industrial site. Bioavailable fractions were determined by sequential extraction with H2O and NH4Cl.Combined treatments of plant hormone and thioligand to strength Hg uptake by crop plants (Brassica juncea and Helianthus annuus) were tested. Plant biomass, evapotranspiration, Hg uptake and distribution following treatments were compared. Results indicate the plant hormone, cytokinine (CK) foliar treatment, increased evapotranspiration rate in both tested plants. The Hg uptake and translocation in both tested plants increased with simultaneous addition of CK and TS treatments. B. juncea was the most effective in Hg uptake. Application of CK to plants grown in TS-treated soil lead to an increase in Hg concentration of 232% in shoots and 39% in roots with respect to control. While H. annuus gave a better response in plant biomass production, the application of CK to plants grown in TS-treated soil lead to an increase in Hg concentration of 248% in shoots and 185% in roots with respect to control plants. The BCS efficiency were evaluated analyzing the labile-Hg residue in the soil after the plant growing. Plants grown with CK and TS in one growing cycle significantly affected labile-Hg pools in soil characterized by sequential extraction, but did not significantly reduce the total metals in the soil. Moreover, if properly optimized, the use of a coupled phytohormone/thioligand system may be a viable strategy to strength Hg uptake by crop plants.

Barbafieri, Meri

2013-04-01

135

Telomerase inhibitor Imetelstat (GRN163L) limits the lifespan of human pancreatic cancer cells.  

PubMed

Telomerase is required for the unlimited lifespan of cancer cells. The vast majority of pancreatic adenocarcinomas overexpress telomerase activity and blocking telomerase could limit their lifespan. GRN163L (Imetelstat) is a lipid-conjugated N3'?P5' thio-phosphoramidate oligonucleotide that blocks the template region of telomerase. The aim of this study was to define the effects of long-term GRN163L exposure on the maintenance of telomeres and lifespan of pancreatic cancer cells. Telomere size, telomerase activity, and telomerase inhibition response to GRN163L were measured in a panel of 10 pancreatic cancer cell lines. The cell lines exhibited large differences in levels of telomerase activity (46-fold variation), but most lines had very short telomeres (2-3 kb in size). GRN163L inhibited telomerase in all 10 pancreatic cancer cell lines, with IC50 ranging from 50 nM to 200 nM. Continuous GRN163L exposure of CAPAN1 (IC50?=?75 nM) and CD18 cells (IC50?=?204 nM) resulted in an initial rapid shortening of the telomeres followed by the maintenance of extremely short but stable telomeres. Continuous exposure to the drug eventually led to crisis and to a complete loss of viability after 47 (CAPAN1) and 69 (CD18) doublings. Crisis In these cells was accompanied by activation of a DNA damage response (?-H2AX) and evidence of both senescence (SA-?-galactosidase activity) and apoptosis (sub-G1 DNA content, PARP cleavage). Removal of the drug after long-term GRN163L exposure led to a reactivation of telomerase and re-elongation of telomeres in the third week of cultivation without GRN163L. These findings show that the lifespan of pancreatic cancer cells can be limited by continuous telomerase inhibition. These results should facilitate the design of future clinical trials of GRN163L in patients with pancreatic cancer. PMID:24409321

Burchett, Katrina M; Yan, Ying; Ouellette, Michel M

2014-01-01

136

Telomerase Inhibitor Imetelstat (GRN163L) Limits the Lifespan of Human Pancreatic Cancer Cells  

PubMed Central

Telomerase is required for the unlimited lifespan of cancer cells. The vast majority of pancreatic adenocarcinomas overexpress telomerase activity and blocking telomerase could limit their lifespan. GRN163L (Imetelstat) is a lipid-conjugated N3??P5? thio-phosphoramidate oligonucleotide that blocks the template region of telomerase. The aim of this study was to define the effects of long-term GRN163L exposure on the maintenance of telomeres and lifespan of pancreatic cancer cells. Telomere size, telomerase activity, and telomerase inhibition response to GRN163L were measured in a panel of 10 pancreatic cancer cell lines. The cell lines exhibited large differences in levels of telomerase activity (46-fold variation), but most lines had very short telomeres (2–3 kb in size). GRN163L inhibited telomerase in all 10 pancreatic cancer cell lines, with IC50 ranging from 50 nM to 200 nM. Continuous GRN163L exposure of CAPAN1 (IC50?=?75 nM) and CD18 cells (IC50?=?204 nM) resulted in an initial rapid shortening of the telomeres followed by the maintenance of extremely short but stable telomeres. Continuous exposure to the drug eventually led to crisis and to a complete loss of viability after 47 (CAPAN1) and 69 (CD18) doublings. Crisis In these cells was accompanied by activation of a DNA damage response (?-H2AX) and evidence of both senescence (SA-?-galactosidase activity) and apoptosis (sub-G1 DNA content, PARP cleavage). Removal of the drug after long-term GRN163L exposure led to a reactivation of telomerase and re-elongation of telomeres in the third week of cultivation without GRN163L. These findings show that the lifespan of pancreatic cancer cells can be limited by continuous telomerase inhibition. These results should facilitate the design of future clinical trials of GRN163L in patients with pancreatic cancer. PMID:24409321

Burchett, Katrina M.; Yan, Ying; Ouellette, Michel M.

2014-01-01

137

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

E-print Network

zones from each of the various districts, an intensive effort was made to eliminate the effects of all variables except the change in speed limit by careful selection 1 of study locations. By studying the strip maps for each speed zone, study... spot speed studies which were affected by additional variables were discovered and removed. Secause this search for additional --- Speed Limit - before Studies Speed Lijsit - After Studies before Stud No. 39 41 After Study No. 40 42 [7 Pace...

Rowan, Neilon Joyce

2012-06-07

138

Detecting neuronal currents with MRI: A human study.  

PubMed

PURPOSE: Recently developed neuronal current magnetic resonance imaging aims to directly detect neuronal currents associated with brain activity, but controversial results have been reported in different studies on human subjects. Although there is no dispute that local neuronal currents produce weak transient magnetic fields that would attenuate local MR signal intensity, there is not yet consensus as to whether this attenuation is detectable with present magnetic resonance imaging techniques. This study investigates the magnitude of neuronal current-induced signal attenuation in human visual cortex. THEORY: A temporally well-controlled visual stimulation paradigm with a known neuronal firing pattern in monkey visual cortex provides a means of detecting and testing the magnitude of the neuronal current-induced attenuation in neuronal current magnetic resonance imaging. METHODS: Placing a series of acquisition windows to fully cover the entire response duration enables a thorough detection of any detectable MR signal attenuation induced by the stimulus-evoked neuronal currents. RESULTS: No significant neuronal current-induced MR signal attenuation was observed in the putative V1 in any participated subjects. CONCLUSION: The present magnetic resonance imaging technique is not sensitive enough to detect neuronal current-induced MR signal attenuation, and the upper limit of this attenuation was found to be less than 0.07% under the study condition. Magn Reson Med, 2013. © 2013 Wiley Periodicals, Inc. PMID:23475847

Huang, Jie

2013-03-01

139

78 FR 35031 - Human Studies Review Board Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...Environmental Protection Agency (EPA) invites nominations from a diverse range of qualified candidates with expertise in bioethics, biostatistics and human health risk assessment to be considered for appointment to its Human Studies Review Board...

2013-06-11

140

Meta-Profiles of Gene Expression during Aging: Limited Similarities between Mouse and Human and an  

E-print Network

are accompanied by a large-scale shift in gene expression, but underlying mechanisms are not understood profiling to investigate the aging skin transcriptome. In humans, age-related shifts in gene expression were patterns and weak human-mouse correspondence may be due to decreased abundance of antigen presenting cells

Bulyk, Martha L.

141

75 FR 18497 - Guidance on Simultaneous Transmission Import Limit Studies for the Northwest Region; Notice of...  

Federal Register 2010, 2011, 2012, 2013

...recent Commission orders on SIL studies \\1\\ and the December 16, 2009...Simultaneous Transmission Import Limit Studies.'' To view the archive of...development of seasonal benchmark cases, completeness of SIL study support data files...

2010-04-12

142

Prevention and treatment of human immunodeficiency virus/acquired immunodeficiency syndrome in resource-limited settings.  

PubMed Central

Strategies for confronting the epidemic of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) have included a range of different approaches that focus on prevention and treatment. However, debate persists over what levels of emphasis are appropriate for the different components of the global response. This paper presents an overview of this debate and briefly summarizes the evidence on a range of interventions designed to prevent the spread of HIV infection, paying particular attention to voluntary counselling and testing, treatment for sexually transmitted infections and prevention of mother-to-child transmission. We also review the experience with antiretroviral therapy to date in terms of response rates and survival rates, adherence, drug resistance, behavioural change and epidemiological impact. Although various studies have identified strategies with proven effectiveness in reducing the risks of HIV infection and AIDS mortality, considerable uncertainties remain. Successful integration of treatment and prevention of HIV/AIDS will require a balanced approach and rigorous monitoring of the impact of programmes in terms of both individual and population outcomes. PMID:15744406

Hogan, Daniel R.; Salomon, Joshua A.

2005-01-01

143

Rheological study of transient networks with junctions of limited multiplicity  

NASA Astrophysics Data System (ADS)

We theoretically study the viscoelastic and thermodynamic properties of transient gels comprised of telechelic associating polymers. We extend classical theories of transient networks so that correlations among polymer chains through the network junctions are taken into account. This extension enables us to investigate how rheological quantities such as elastic modulus, viscosity, and relaxation time are affected by the association equilibrium, and how these quantities are related to the aggregation number (or multiplicity) of the junctions. In this paper, we assume, in the conventional manner, that chains are elastically effective if both their ends are connected with other chains. It is shown that the dynamic shear moduli are well described in terms of the Maxwell model. As a result of the correlation, the reduced moduli (moduli divided by the polymer concentration) increase with the concentration, but become independent of the concentration in the high-concentration range. The fraction of pairwise junctions is larger at lower concentrations, indicating the presence of concatenated chains in the system, which decreases as the concentration increases. This leads to a network relaxation time that increases with the concentration.

Indei, Tsutomu

2007-10-01

144

[Seroepidemiologic study of human plague in Madagascar].  

PubMed

An IgG anti-F1 Enzyme linked immunosorbent assay (Elisa) has been developed for plague diagnosis in the Malagasy republic. The sensitivity of the test was 91.4% and the specificity 98.5%. This technique is cheap and the cross reaction with other infections diseases prevalent in Madagascar is very limited. During the urban plague outbreak (Mahajanga city, 1995), the positive predictive value and the negative predictive value were 95.2% and 97% respectively. During this outbreak, the usefulness of the Elisa test for retrospective individual serodiagnosis was confirmed. Furthermore, the test confirmed plague among suspect patients without bacteriological diagnosis. The test was used for a sero-epidemiological study. Eight villages in the endemic area were investigated and 900 persons were studied. The overall seroprevalence was 6 times the officially prevalence of plague, notified at the Central Plague Laboratory. A large disparity of the seroprevalence was observed in the endemic area, with variation from < 1.5% to 15.5%. A high incidence of asymptomatic infections due to Yersinia pestis was found. PMID:9309233

Leroy, F

1997-01-01

145

Light for nurses' work in the 21st century: a review of lighting, human vision limitations, and medication administration.  

PubMed

A literature review was conducted to determine the state of the science related to medication errors and light. The limited literature is discussed in relationship to human vision and light needs. Little systematic action has been taken to increase nurses' awareness of the connection between lighting and potential medication errors. Implications for nursing practice and research about light conditions are provided. Interventions from other industries may aid nursing in making decisions about light conditions. PMID:24335492

Graves, Krisanne; Symes, Lene; Cesario, Sandra K

2014-01-01

146

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

Microsoft Academic Search

: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

Jian Chen

2010-01-01

147

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

Microsoft Academic Search

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

Jian Chen

2010-01-01

148

Human Immunodeficiency Virus (HIV) Reverse Transcriptase Activity Correlates with HIV RNA Load: Implications for Resource-Limited Settings  

Microsoft Academic Search

Measurement of human immunodeficiency virus type 1 (HIV-1) plasma RNA levels using Roche AMPLICOR version 1.5 (HIV RNA) is an integral part of monitoring HIV-infected patients in industrialized countries. These assays are currently unaffordable in resource-limited settings. We investigated a reverse transcriptase (RT) assay as a less expensive alternative for measuring viral burden that quantifies RT enzyme activity in clinical

Sumathi Sivapalasingam; Shaffiq Essajee; Phillipe N. Nyambi; Vincenza Itri; Bruce Hanna; Robert Holzman; Fred Valentine

2005-01-01

149

Evidence for Viral Virulence as a Predominant Factor Limiting Human Immunodeficiency Virus Vaccine Efficacy  

Microsoft Academic Search

Current strategies in human immunodeficiency virus type 1 (HIV-1) vaccine development are often based on the production of different vaccine antigens according to particular genetic clades of HIV-1 variants. To determine if virus virulence or genetic distance had a greater impact on HIV-1 vaccine efficacy, we designed a series of heterologous chimeric simian\\/human immunodeficiency virus (SHIV) challenge experiments in HIV-1

PETRA MOOIJ; WILLY M. J. M. BOGERS; HERMAN OOSTERMEIJER; WIM KOORNSTRA; PETER J. F. TEN HAAFT; BABS E. VERSTREPEN; GERT VAN DER AUWERA; JONATHAN L. HEENEY

2000-01-01

150

A Brief History of Soils and Human Health Studies  

NASA Astrophysics Data System (ADS)

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;

Brevik, Eric C.; Sauer, Thomas J.

2013-04-01

151

Studying the immune response to human viral infections using zebrafish.  

PubMed

Humans and viruses have a long co-evolutionary history. Viral illnesses have and will continue to shape human history: from smallpox, to influenza, to HIV, and beyond. Animal models of human viral illnesses are needed in order to generate safe and effective antiviral medicines, adjuvant therapies, and vaccines. These animal models must support the replication of human viruses, recapitulate aspects of human viral illnesses, and respond with conserved immune signaling cascades. The zebrafish is perhaps the simplest, most commonly used laboratory model organism in which innate and/or adaptive immunity can be studied. Herein, we will discuss the current zebrafish models of human viral illnesses and the insights they have provided. We will highlight advantages of early life stage zebrafish and the importance of innate immunity in human viral illnesses. We will also discuss viral characteristics to consider before infecting zebrafish with human viruses as well as predict other human viruses that may be able to infect zebrafish. PMID:24718256

Goody, Michelle F; Sullivan, Con; Kim, Carol H

2014-09-01

152

Evaluation of streams in selected communities for the application of limited-detail study methods for flood-insurance studies  

USGS Publications Warehouse

The U.S. Geological Survey evaluated 2,349 communities in 1984 for the application of limited-detail flood-insurance study methods, that is, methods with a reduced effort and cost compared to the detailed studies. Limited-detail study methods were found to be appropriate for 1,705 communities, while detailed studies were appropriate for 62 communities and no studies were appropriate for 582 communities. The total length of streams for which limited-detail studies are recommended is 9 ,327 miles with a corresponding cost of $23,007,000. This results in average estimated costs for conducting limited-detail studies of $2,500 per mile of studied stream length. The purpose of the report is to document the limited-detail study methods and the results of the evaluation. (USGS)

Cobb, Ernest D.

1986-01-01

153

Human Motion in Cooperative Tasks: Moving Object Case Study  

E-print Network

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

Paris-Sud XI, Université de

154

Studying Human Dynamics Through Web Analytics  

NASA Astrophysics Data System (ADS)

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.

Ramasco, Jose; Goncalves, Bruno

2008-03-01

155

Studying food reward and motivation in humans.  

PubMed

A key challenge in studying reward processing in humans is to go beyond subjective self-report measures and quantify different aspects of reward such as hedonics, motivation, and goal value in more objective ways. This is particularly relevant for the understanding of overeating and obesity as well as their potential treatments. In this paper are described a set of measures of food-related motivation using handgrip force as a motivational measure. These methods can be used to examine changes in food related motivation with metabolic (satiety) and pharmacological manipulations and can be used to evaluate interventions targeted at overeating and obesity. However to understand food-related decision making in the complex food environment it is essential to be able to ascertain the reward goal values that guide the decisions and behavioral choices that people make. These values are hidden but it is possible to ascertain them more objectively using metrics such as the willingness to pay and a method for this is described. Both these sets of methods provide quantitative measures of motivation and goal value that can be compared within and between individuals. PMID:24686284

Ziauddeen, Hisham; Subramaniam, Naresh; Cambridge, Victoria C; Medic, Nenad; Farooqi, Ismaa Sadaf; Fletcher, Paul C

2014-01-01

156

Studying Food Reward and Motivation in Humans  

PubMed Central

A key challenge in studying reward processing in humans is to go beyond subjective self-report measures and quantify different aspects of reward such as hedonics, motivation, and goal value in more objective ways. This is particularly relevant for the understanding of overeating and obesity as well as their potential treatments. In this paper are described a set of measures of food-related motivation using handgrip force as a motivational measure. These methods can be used to examine changes in food related motivation with metabolic (satiety) and pharmacological manipulations and can be used to evaluate interventions targeted at overeating and obesity. However to understand food-related decision making in the complex food environment it is essential to be able to ascertain the reward goal values that guide the decisions and behavioral choices that people make. These values are hidden but it is possible to ascertain them more objectively using metrics such as the willingness to pay and a method for this is described. Both these sets of methods provide quantitative measures of motivation and goal value that can be compared within and between individuals. PMID:24686284

Ziauddeen, Hisham; Subramaniam, Naresh; Cambridge, Victoria C.; Medic, Nenad; Farooqi, Ismaa Sadaf; Fletcher, Paul C.

2014-01-01

157

Rabbit as a Model for the Study of Human Diseases  

Microsoft Academic Search

Although genetically modified mice are playing an essential role in the study of the expression and functions of individual\\u000a genes, rabbits are useful animal models to extrapolate animal studies to humans. It is necessary that key gene expression\\u000a and function are equivalent and close to human rather than the outward features or phenotype. For example, to study human\\u000a hypercholesterolemia, the

Masashi Shiomi

158

All That Glitters Isn't Gold: A Survey on Acknowledgment of Limitations in Biomedical Studies  

PubMed Central

Background Acknowledgment of all serious limitations to research evidence is important for patient care and scientific progress. Formal research on how biomedical authors acknowledge limitations is scarce. Objectives To assess the extent to which limitations are acknowledged in biomedical publications explicitly, and implicitly by investigating the use of phrases that express uncertainty, so-called hedges; to assess the association between industry support and the extent of hedging. Design We analyzed reporting of limitations and use of hedges in 300 biomedical publications published in 30 high and medium -ranked journals in 2007. Hedges were assessed using linguistic software that assigned weights between 1 and 5 to each expression of uncertainty. Results Twenty-seven percent of publications (81/300) did not mention any limitations, while 73% acknowledged a median of 3 (range 1–8) limitations. Five percent mentioned a limitation in the abstract. After controlling for confounders, publications on industry-supported studies used significantly fewer hedges than publications not so supported (p?=?0.028). Limitations Detection and classification of limitations was – to some extent – subjective. The weighting scheme used by the hedging detection software has subjective elements. Conclusions Reporting of limitations in biomedical publications is probably very incomplete. Transparent reporting of limitations may protect clinicians and guideline committees against overly confident beliefs and decisions and support scientific progress through better design, conduct or analysis of new studies. PMID:24324540

ter Riet, Gerben; Chesley, Paula; Gross, Alan G.; Siebeling, Lara; Muggensturm, Patrick; Heller, Nadine; Umbehr, Martin; Vollenweider, Daniela; Yu, Tsung; Akl, Elie A.; Brewster, Lizzy; Dekkers, Olaf M.; Mühlhauser, Ingrid; Richter, Bernd; Singh, Sonal; Goodman, Steven; Puhan, Milo A.

2013-01-01

159

October 19, 2009 Team to study human effect on watershed  

E-print Network

October 19, 2009 Team to study human effect on watershed Research will chart carbon cycle in 565 in a watershed," Aufdenkampe said. "Specifically, how is human erosion affecting the carbon cycle?" Six studies and Christina River watersheds, is one of six areas in the United States where scientists will study watersheds

Sparks, Donald L.

160

Teacher Leader Human Relations Skills: A Comparative Study  

ERIC Educational Resources Information Center

In this study, 142 graduate school teachers working in schools throughout southwestern Ohio assessed their human relation skills. A human relations survey was used for the study, and results were compared with colleagues assessing the teachers in the study. The survey was developed using a Likert-type scale, and was based on key elements affecting…

Roby, Douglas E.

2012-01-01

161

A pair of roseate terns fledges three young with limited human assistance  

USGS Publications Warehouse

In 1994 when the availability of small fish appeared to be relatively good, the smallest chick from an inadvertantly artificially-created 3-egg clutch received occasional supplemental feedings by humans for two weeks. These supplemental feedings probably prevented this chick from starving. During its period of most rapid growth (after the linear growth phase of its two siblings had ended), however, it did not receive supplemental feedings from humans, but was instead was fed only by the two adult birds attending the nest. All the chicks in this brood eventually fledged, indicating that the pair was capable of meeting the feeding demands of three large chicks.

Spendelow, J.A.; Zingo, J.M.; Foss, S.

1997-01-01

162

Studying Risk Factors Associated with Human Leptospirosis  

PubMed Central

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

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

2014-01-01

163

Looking toward the Future: A Case Study of Open Source Software in the Humanities  

ERIC Educational Resources Information Center

In this article Harvey Quamen examines how the philosophy of open source software might be of particular benefit to humanities scholars in the near future--particularly for academic journals with limited financial resources. To this end he provides a case study in which he describes his use of open source technology (MySQL database software and…

Quamen, Harvey

2006-01-01

164

Evaluation of tolerance limits for humans under heat stress and the problems involved.  

PubMed

Investigators are divided about the limits of tolerable ambient temperatures and air humidities, even under equal boundary conditions. In 266 climatic chamber experiments, mostly lasting 4 h, 13 young healthy men were exposed to combinations of ambient temperature (20 to 55 degrees C) and relative humidity (5 to 97%) at an air velocity of 0.3 m.s-1. They were lightly clad and performed equal treadmill work (metabolic rate about 850 kJ.h-1). Mean rectal isotherms and their standard deviations were calculated from the final rectal temperatures of the 13 men and plotted on a psychrometric chart. The slopes of the isotherms were compared with those of various "indices of heat stress." The probability of reaching the potentially critical rectal temperature of 39 degrees C was calculated according to data of Wyndham & Heyns. It increased from about 1:500,000 to 1:150 in climates corresponding to mean isotherms of 37.6 and 38.2 degrees C, respectively. Most of the limits thus far proposed are situated between these two isotherms, and they differ merely in regard to health risk. It is useless to discuss "correct" or "incorrect" limits until society has decided what risk is to be accepted. An upper tolerable limit per se does not and cannot exist. For several reasons the 37.6 degrees C isotherm might be taken into consideration as a limit. PMID:2609123

Wenzel, H G; Mehnert, C; Schwarzenau, P

1989-01-01

165

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

PubMed Central

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

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

2013-01-01

166

Gender Inequality, Poverty and Human Development in Kenya: Main Indicators, Trends and Limitations  

Microsoft Academic Search

Indicators of gender inequality, poverty and human development in Kenya are examined. Significant and rising incidence of absolute poverty occurs in Kenya and women are more likely to be in poverty than men. Female\\/male ratios in Kenyan decision-making institutions are highly skewed against women and they experience unfavourable enrolment ratios in primary, secondary and tertiary institutions. The share of income

Tabitha Kiriti; Clement A. Tisdell

2003-01-01

167

SAFETY, IDENTITY AND CONSENT: A LIMITED DEFENSE OF REPRODUCTIVE HUMAN CLONING  

Microsoft Academic Search

ABSTRACTSome 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

2006-01-01

168

PUSH(ing) Limits: Using Fiction in the Classroom for Human Behavior and the Social Environment  

ERIC Educational Resources Information Center

The use of fiction and autobiography in social science course work has been shown to enhance students' learning experience. Using the novel PUSH, by Sapphire, we designed a curriculum supplement for the social work course, human behavior and the social environment (HBSE) that encourages students to integrate course content in an innovative way and…

Mendoza, Natasha S.; Bonta, Kimberly; Horn, Philip; Moore, Erin; Gibson, Allison; Simmons, David

2012-01-01

169

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...

170

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

Microsoft Academic Search

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

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

2011-01-01

171

Epidemiologic studies of behavioral health following the deepwater horizon oil spill: limited impact or limited ability to measure?  

PubMed

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

Teich, Judith L; Pemberton, Michael R

2015-01-01

172

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

PubMed Central

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

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

2013-01-01

173

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

SciTech Connect

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.

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

174

Katanin p80 Regulates Human Cortical Development by Limiting Centriole and Cilia Number.  

PubMed

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

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

175

REPORTING NEEDS FOR STUDIES OF ENVIRONMENTAL CHEMICALS IN HUMAN MILK  

E-print Network

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

California at Berkeley, University of

176

Roadmap: Physical Education Human Movement Studies Bachelor of Science  

E-print Network

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

Sheridan, Scott

177

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

E-print Network

. We found a slight tendency for egg load to drop during the course of the day. Although we couldEgg Limitation in Parasitoids: A Review of the Evidence and a Case Study George E. Heimpel* and Jay exhaust their egg supply during their lifetime. We reviewed the literature on egg limitation

Rosenheim, Jay A.

178

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain  

E-print Network

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain by Benchun Duan and Steven M. Day Abstract Physical limits on ground-motion parameters can be estimated from spontaneous untruncated lognormal distributions for the ground-motion parameters. A result is that, when PSHA is applied

Duan, Benchun

179

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain  

E-print Network

1 Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain Benchun Duan1 and Steven for Publication in BSSA May 10, 2010 #12;2 Abstract1 Physical limits on ground motion parameters can be estimated distributions for the ground motion parameters. A result is that when PSHA is applied22 at very low probability

Duan, Benchun

180

The experiment study on SPP stablizer treating with Guangxi high liquid limit soil  

Microsoft Academic Search

Treatment with high liquid limit soil is a thorny problem on highway building for the purpose of searching a new, handy and economical soil-improved technique, the indoor experiment study on SPP stablizers which treat with the two typical high liquid limit soil in Guangxi is carried out. The result and its analysis is illustrated in this document.

Ou Ou; Yi Nian-ping; Zhang Xin-gui

2010-01-01

181

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

ERIC Educational Resources Information Center

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…

Halquist, Don

182

Spatial Genetic Structure Patterns of Phenotype-Limited and Boundary-Limited Expanding Populations: A Simulation Study  

PubMed Central

Range expansions may create a unique spatial genetic pattern characterized by alternate genetically homogeneous domains and allele frequency clines. Previous attempts to model range expansions have mainly focused on the loss of genetic diversity during expansions. Using individual-based models, we examined spatial genetic patterns under two expansion scenarios, boundary-limited range expansions (BLRE) and phenotype-limited range expansions (PhLRE). Our simulation revealed that the genetic diversity within populations lost quickly during the range expansion, while the genetic difference accumulated between populations. Consequently, accompanying the expansions, the overall diversity featured a slow decrease. Specifically, during BLREs, high speed of boundary motion facilitated the maintenance of total genetic diversity and sharpened genetic clines. Very slight constraints on boundary motion of BLREs drastically narrowed the homogeneous domains and increased the allele frequency fluctuations from those levels exhibited by PhLREs. Even stronger constraints, however, surprisingly brought the width of homogeneous domains and the allele frequency fluctuations back to the normal levels of PhLREs. Furthermore, high migration rates maintained a higher total genetic diversity than low ones did during PhLREs. Whereas, the total genetic diversities during BLREs showed a contrary pattern: higher when migration was low than those when migration was high. Besides, the increase of migration rates helped maintain a greater number of homogeneous domains during PhLREs, but their effects on the number of homogeneous domains during BLREs were not monotonous. Previous studies have showed that the homogenous domains can merge to form a few broad domains as the expansion went on, leading to fewer homogeneous domains. Our simulations, meanwhile, revealed that the range expansions could also rebuild homogeneous domains from the clines during the range expansion. It is possible that that the number of homogeneous domains was determined by the interaction of merging and newly emerging homogeneous domains. PMID:24465700

Dai, Qiang; Zhan, Xiangjiang; Lu, Bin; Fu, Jinzhong; Wang, Qian; Qi, Dunwu

2014-01-01

183

Twins for epigenetic studies of human aging and development.  

PubMed

Most of the complex traits including aging phenotypes are caused by the interaction between genome and environmental conditions and the interface of epigenetics may be a central mechanism. Although modern technologies allow us high-throughput profiling of epigenetic patterns already at genome level, our understanding of genetic and environmental influences on the epigenetic processes remains limited. Twins are of special interest for genetic studies due to their genetic similarity and rearing-environment sharing. The classical twin design has made a great contribution in dissecting the genetic and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable sample of twins is helping to bridge the gap between gene activity and the environments through epigenetic mechanisms unlimited by DNA sequence variations. We propose to extend the classical twin design to study the aging-related molecular epigenetic phenotypes and link them with environmental exposures especially early life events. Different study designs and application issues will be highlighted and novel approaches introduced with aim at making uses of twins in assessing the environmental impact on epigenetic changes during development and in the aging process. PMID:22750314

Tan, Qihua; Christiansen, Lene; Thomassen, Mads; Kruse, Torben A; Christensen, Kaare

2013-01-01

184

O{sub 2}-mediated oxidation of ferrous nitrosylated human serum heme-albumin is limited by nitrogen monoxide dissociation  

SciTech Connect

Research highlights: {yields} Human serum heme-albumin displays globin-like properties. {yields} O{sub 2}-mediated oxidation of ferrous nitrosylated human serum heme-albumin. {yields} Allosteric modulation of human serum heme-albumin reactivity. {yields} Rifampicin is an allosteric effector of human serum heme-albumin. {yields} Human serum heme-albumin is a ROS and NOS scavenger. -- Abstract: Human serum heme-albumin (HSA-heme-Fe) displays globin-like properties. Here, kinetics of O{sub 2}-mediated oxidation of ferrous nitrosylated HSA-heme-Fe (HSA-heme-Fe(II)-NO) is reported. Values of the first-order rate constants for O{sub 2}-mediated oxidation of HSA-heme-Fe(II)-NO (i.e., for ferric HSA-heme-Fe formation) and for NO dissociation from HSA-heme-Fe(II)-NO (i.e., for NO replacement by CO) are k = 9.8 x 10{sup -5} and 8.3 x 10{sup -4} s{sup -1}, and h = 1.3 x 10{sup -4} and 8.5 x 10{sup -4} s{sup -1}, in the absence and presence of rifampicin, respectively, at pH = 7.0 and T = 20.0 {sup o}C. The coincidence of values of k and h indicates that NO dissociation represents the rate limiting step of O{sub 2}-mediated oxidation of HSA-heme-Fe(II)-NO. Mixing HSA-heme-Fe(II)-NO with O{sub 2} does not lead to the formation of the transient adduct(s), but leads to the final ferric HSA-heme-Fe derivative. These results reflect the fast O{sub 2}-mediated oxidation of ferrous HSA-heme-Fe and highlight the role of drugs in modulating allosterically the heme-Fe-atom reactivity.

Ascenzi, Paolo, E-mail: ascenzi@uniroma3.it [Interdepartmental Laboratory of Electron Microscopy, University Roma Tre, Via della Vasca Navale 79, I-00146 Roma (Italy) [Interdepartmental Laboratory of Electron Microscopy, University Roma Tre, Via della Vasca Navale 79, I-00146 Roma (Italy); National Institute for Infectious Diseases I.R.C.C.S. 'Lazzaro Spallanzani', Via Portuense 292, I-00149 Roma (Italy); Gullotta, Francesca; Gioia, Magda; Coletta, Massimo [Department of Experimental Medicine and Biochemical Sciences, University of Roma 'Tor Vergata', Via Montpellier 1, I-00133 Roma (Italy) [Department of Experimental Medicine and Biochemical Sciences, University of Roma 'Tor Vergata', Via Montpellier 1, I-00133 Roma (Italy); Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Piazza Umberto I 1, I-87100 Bari (Italy); Fasano, Mauro [Department of Structural and Functional Biology, and Center of Neuroscience, University of Insubria, Via Alberto da Giussano 12a, I-21052 Busto Arsizio, VA (Italy)] [Department of Structural and Functional Biology, and Center of Neuroscience, University of Insubria, Via Alberto da Giussano 12a, I-21052 Busto Arsizio, VA (Italy)

2011-03-04

185

Electrophysiological Studies of Face Perception in Humans  

Microsoft Academic Search

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

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

1996-01-01

186

Focuson Arts & Humanities for study abroad advisors  

E-print Network

N SHAKESPEArE'S gLObE tHEAtrE HOUSES OF PArLiAMENt · Royal Academy of Music · British Lib of an expansion phase which will see it double in size between 2010 and 2014. Our History Department early modern English/Shakespeare), and History (including Medieval History, Medical Humanities

Applebaum, David

187

World History [Humanities]. Course of Study.  

ERIC Educational Resources Information Center

World history guides students to an understanding of culture, geography, and diversity of expression using a historical chronology that illustrates humankind's connections throughout the world. The state of Idaho mandates a core requirement of two credits to be completed in the field of arts and humanities. To achieve success in this core…

Idaho State Dept. of Education, Boise.

188

An epidemiologic study of the human bite.  

PubMed Central

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

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

1979-01-01

189

Application of chimeric mice with humanized liver for study of human-specific drug metabolism.  

PubMed

Human-specific or disproportionately abundant human metabolites of drug candidates that are not adequately formed and qualified in preclinical safety assessment species pose an important drug development challenge. Furthermore, the overall metabolic profile of drug candidates in humans is an important determinant of their drug-drug interaction susceptibility. These risks can be effectively assessed and/or mitigated if human metabolic profile of the drug candidate could reliably be determined in early development. However, currently available in vitro human models (e.g., liver microsomes, hepatocytes) are often inadequate in this regard. Furthermore, the conduct of definitive radiolabeled human ADME studies is an expensive and time-consuming endeavor that is more suited for later in development when the risk of failure has been reduced. We evaluated a recently developed chimeric mouse model with humanized liver on uPA/SCID background for its ability to predict human disposition of four model drugs (lamotrigine, diclofenac, MRK-A, and propafenone) that are known to exhibit human-specific metabolism. The results from these studies demonstrate that chimeric mice were able to reproduce the human-specific metabolite profile for lamotrigine, diclofenac, and MRK-A. In the case of propafenone, however, the human-specific metabolism was not detected as a predominant pathway, and the metabolite profiles in native and humanized mice were similar; this was attributed to the presence of residual highly active propafenone-metabolizing mouse enzymes in chimeric mice. Overall, the data indicate that the chimeric mice with humanized liver have the potential to be a useful tool for the prediction of human-specific metabolism of xenobiotics and warrant further investigation. PMID:24700822

Bateman, Thomas J; Reddy, Vijay G B; Kakuni, Masakazu; Morikawa, Yoshio; Kumar, Sanjeev

2014-06-01

190

No monkey business: why studying NK cells in non-human primates pays off  

PubMed Central

Human NK (hNK) cells play a key role in mediating host immune responses against various infectious diseases. For practical reasons, the majority of the data on hNK cells has been generated using peripheral blood lymphocytes. In contrast, our knowledge of NK cells in human tissues is limited, and not much is known about developmental pathways of hNK cell subpopulations in vivo. Although research in mice has elucidated a number of fundamental features of NK cell biology, mouse, and hNK cells significantly differ in their subpopulations, functions, and receptor repertoires. Thus, there is a need for a model that is more closely related to humans and yet allows experimental manipulations. Non-human primate models offer numerous opportunities for the study of NK cells, including the study of the role of NK cells after solid organ and stem cell transplantation, as well as in acute viral infection. Macaque NK cells can be depleted in vivo or adoptively transferred in an autologous system. All of these studies are either difficult or unethical to carry out in humans. Here we highlight recent advances in rhesus NK cell research and their parallels in humans. Using high-throughput transcriptional profiling, we demonstrate that the human CD56bright and CD56dim NK cell subsets have phenotypically and functionally analogous counterparts in rhesus macaques. Thus, the use of non-human primate models offers the potential to substantially advance hNK cell research. PMID:23423644

Hong, Henoch S.; Rajakumar, Premeela A.; Billingsley, James M.; Reeves, R. Keith; Johnson, R. Paul

2012-01-01

191

Designing studies of drug conditioning in humans  

Microsoft Academic Search

There has been much recent interest in the possibility that signals for drug use in humans acquire the ability to evoke classically\\u000a conditioned (learned) states which motivate drug taking. Much data now suggest that cues paired with drug use come to elicit\\u000a physiological responses and subjective reports of drug-related feelings like craving and withdrawal. However, the designs\\u000a employed do not

Steven J. Robbins; Ronald N. Ehrman

1992-01-01

192

Empirical study on human acupuncture point network  

NASA Astrophysics Data System (ADS)

Chinese medical theory is ancient and profound, however is confined by qualitative and faint understanding. The effect of Chinese acupuncture in clinical practice is unique and effective, and the human acupuncture points play a mysterious and special role, however there is no modern scientific understanding on human acupuncture points until today. For this reason, we attend to use complex network theory, one of the frontiers in the statistical physics, for describing the human acupuncture points and their connections. In the network nodes are defined as the acupuncture points, two nodes are connected by an edge when they are used for a medical treatment of a common disease. A disease is defined as an act. Some statistical properties have been obtained. The results certify that the degree distribution, act degree distribution, and the dependence of the clustering coefficient on both of them obey SPL distribution function, which show a function interpolating between a power law and an exponential decay. The results may be helpful for understanding Chinese medical theory.

Li, Jian; Shen, Dan; Chang, Hui; He, Da-Ren

2007-03-01

193

A simulation study of the lower limit of permeability for a commercially feasible gas well  

E-print Network

A SIMULATION STUDY OF THE LOWER LIMIT OF PERMEABILITY FOR A COMMERCIALLY FEASIBLE GAS WELL A Thesis by CHIMELA WACHUKWU NWAOGWUGWU Submitted to the Graduate College of Texas AIIM University in partial fultillment of the requirement... for the degree of MASTER OF SCIENCE May 1979 Major Subject: Petroleum Engineering A SIMULATION STUDY OF THE LOWER LIMIT OF PERMEABILITY FOR A COMMERCIALLY FEASIBLE GAS WELL A Thesis by CHIMELA WACHUKWU NWAOGWUGWU Approved as to style and content by: )gg...

Nwaogwugwu, Chimela Wachukwu

1979-01-01

194

Combined spectrophotometry and tensile measurements of human connective tissues: potentials and limitations.  

PubMed

Strain-dependent transmission data of nine iliotibial tract specimens are determined using a custom-built optical setup with a halogen light source and an industrial norm material testing machine. Polarized light microscopy and hematoxylin-eosin staining indicated that lateral contraction of collagen structures is responsible for total intensity variations during a 20-cycle preconditioning and a 5-cycle tensile test. Tensile force progress is opposite to total transmission progress. Due to dehydration, wavelength-specific radiation intensity shifting is determined during the test, primarily noticeable in a water absorption band between 1400 and 1500 nm. The results show the capability of integrating spectrophotometry technology into biomechanics for determining structural alterations of human collagen due to applied strain. Being more sensitive to drying, spectrophotometry may likely serve as a quality control in stress-strain testing of biological structures. PMID:23797894

Ernstberger, Markus; Sichting, Freddy; Baselt, Tobias; Hartmann, Peter; Aust, Gabriela; Hammer, Niels

2013-06-01

195

Combined spectrophotometry and tensile measurements of human connective tissues: potentials and limitations  

NASA Astrophysics Data System (ADS)

Strain-dependent transmission data of nine iliotibial tract specimens are determined using a custom-built optical setup with a halogen light source and an industrial norm material testing machine. Polarized light microscopy and hematoxylin-eosin staining indicated that lateral contraction of collagen structures is responsible for total intensity variations during a 20-cycle preconditioning and a 5-cycle tensile test. Tensile force progress is opposite to total transmission progress. Due to dehydration, wavelength-specific radiation intensity shifting is determined during the test, primarily noticeable in a water absorption band between 1400 and 1500 nm. The results show the capability of integrating spectrophotometry technology into biomechanics for determining structural alterations of human collagen due to applied strain. Being more sensitive to drying, spectrophotometry may likely serve as a quality control in stress-strain testing of biological structures.

Ernstberger, Markus; Sichting, Freddy; Baselt, Tobias; Hartmann, Peter; Aust, Gabriela; Hammer, Niels

2013-06-01

196

Antecedent Avian Immunity Limits Tangential Transmission of West Nile Virus to Humans  

PubMed Central

Background West Nile virus (WNV) is a mosquito-borne flavivirus maintained and amplified among birds and tangentially transmitted to humans and horses which may develop terminal neuroinvasive disease. Outbreaks typically have a three-year pattern of silent introduction, rapid amplification and subsidence, followed by intermittent recrudescence. Our hypothesis that amplification to outbreak levels is contingent upon antecedent seroprevalence within maintenance host populations was tested by tracking WNV transmission in Los Angeles, California from 2003 through 2011. Methods Prevalence of antibodies against WNV was monitored weekly in House Finches and House Sparrows. Tangential or spillover transmission was measured by seroconversions in sentinel chickens and by the number of West Nile neuroinvasive disease (WNND) cases reported to the Los Angeles County Department of Public Health. Results Elevated seroprevalence in these avian populations was associated with the subsidence of outbreaks and in the antecedent dampening of amplification during succeeding years. Dilution of seroprevalence by recruitment resulted in the progressive loss of herd immunity following the 2004 outbreak, leading to recrudescence during 2008 and 2011. WNV appeared to be a significant cause of death in these avian species, because the survivorship of antibody positive birds significantly exceeded that of antibody negative birds. Cross-correlation analysis showed that seroprevalence was negatively correlated prior to the onset of human cases and then positively correlated, peaking at 4–6 weeks after the onset of tangential transmission. Antecedent seroprevalence during winter (Jan – Mar) was negatively correlated with the number of WNND cases during the succeeding summer (Jul–Sep). Conclusions Herd immunity levels within after hatching year avian maintenance host populations <10% during the antecedent late winter and spring period were followed on three occasions by outbreaks of WNND cases during the succeeding summer. Because mosquitoes feed almost exclusively on these avian species, amplification was directly related to the availability of receptive non-immune hosts. PMID:22457819

Kwan, Jennifer L.; Kluh, Susanne; Reisen, William K.

2012-01-01

197

A human laboratory pilot study with baclofen in alcoholic individuals.  

PubMed

Preclinical and clinical studies show that the GABA(B) 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 10mg t.i.d. or an active placebo (cyproheptadine 2mg 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

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

2013-02-01

198

A human laboratory pilot study with baclofen in alcoholic individuals  

PubMed Central

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

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

199

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

Microsoft Academic Search

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

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

2010-01-01

200

An Interdisciplinary Deer and Human Population Study  

NSDL National Science Digital Library

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.

Webb, William J.

2009-01-01

201

Insights from human studies into the host defense against candidiasis  

Microsoft Academic Search

Candida spp. are the most common cause of mucosal and disseminated fungal infections in humans. Studies using mutant strains of mice have provided initial information about the roles of dectin-1, CARD9, and Th17 cytokines in the host defense against candidiasis. Recent technological advances have resulted in the identification of mutations in specific genes that predispose humans to develop candidal infection.

Scott G. Filler

202

Knowledge gaining by human genetic studies on tuberculosis susceptibility  

Microsoft Academic Search

Tuberculosis (TB) is a serious health issue in the developing world. Lack of knowledge on the etiological mechanisms of TB hinders the development of effective strategies for the treatment or prevention of TB disease. Human genetic study is an indispensable approach to understand the molecular basis of common diseases. Numerous efforts were made to screen the human genome for TB

Hui-Qi Qu; Susan P Fisher-Hoch; Joseph B McCormick

2011-01-01

203

Protection of Human Subjects: Implications for Social Studies Research.  

ERIC Educational Resources Information Center

Current regulatory trends, policies, and procedures greatly affect social studies research using human subjects and evaluation of that research. The legal source of protection of human subjects is the National Research Act of 1974. The law stipulates that rights of research subjects must be protected and that the responsibility is on the…

Turner, Thomas N.

204

Humans as a Case Study for the Evidence of Evolution.  

ERIC Educational Resources Information Center

Discusses the strengths of the many lines of scientific evidence supporting the idea of human evolution and the importance of the agreement that exists between them. Argues that using humans as a case study in evolution allows educators to illustrate broader aspects of the nature of science and how the overall strength of any scientific…

Nickels, Martin

1998-01-01

205

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

E-print Network

MAJOR: HUMAN DEVELOPMENT & FAMILY STUDIES (HDFS) EMPHASIS: EARLY CHILDHOOD EDCUATION Minimum HDFS (11 Credit Hours) F, S, SU FCS 3200 Research Methods 4 F, S, SU FCS 3210 Statistics (QB/QI) 4 F, S, SU 2. HDFS CORE (6 Credit Hours) F, S, SU FCS 1500 Human Development Across the Lifespan (BF) 3 F, S

Tipple, Brett

206

Occupation- and exposure-related studies on human sperm.  

PubMed

Many kinds of exposures and chemicals have been shown to affect human sperm quantity and quality. This review focuses first on the best known occupational testicular toxin, dibromochloropropane. Prolonged heat is clearly detrimental to spermatogenesis. Studies on occupational heat, radiation, and chemical exposures and their effects on sperm are reviewed. The evaluation of human sperm studies is hampered by inconsistencies in biological analytical methods, in control for confounders, and in weaknesses of study design. Still, there is reason to suggest that human semen parameters can serve as valuable indicators of toxic and, in future, even genotoxic effects of occupational and environmental factors. PMID:8520954

Lähdetie, J

1995-08-01

207

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

PubMed

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

McFarland, Sam; Webb, Matthew; Brown, Derek

2012-11-01

208

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

NASA Astrophysics Data System (ADS)

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].

Lundquist, Marjorie

2005-03-01

209

Energy adaptations in human pregnancy: limits and long-term consequences.  

PubMed

The very slow rate of human fetal growth generates a lower incremental energy stress than in any other mammalian species. This creates a situation in which adaptive changes in metabolic rate and in the amount of additional maternal fat stored during gestation can make a profound difference to the overall energy needs of pregnancy. Comparisons of women in affluent and poor countries have recorded mean population energy needs ranging from as high as 520 MJ to as low as -30 MJ per pregnancy. These energy costs are closely correlated with maternal energy status when analyzed both between and within populations, suggesting that they represent functional adaptations that have been selected for their role in protecting fetal growth. Although this metabolic plasticity represents a powerful mechanism for sustaining pregnancy under very marginal nutritional conditions, it must not be construed as a perfect mechanism that obviates the need for optimal nutritional care of pregnant women. The fact that fetal weight represents up to 60% of total pregnancy weight gain in many pregnancies in poor societies (compared with a well-nourished norm of 25%) indicates that the fetus is developing under suboptimal nutritional and physiologic conditions. It has long been recognized that this has immediate consequences for the offspring in terms of increased perinatal mortality. The more recent appreciation that impaired fetal growth may also precipitate longer-term defects in terms of adult susceptibility to noncommunicable and infectious diseases reinforces the view that pregnancy may be the most sensitive period of the life cycle in which nutritional intervention may reap the greatest benefits. PMID:10799395

Prentice, A M; Goldberg, G R

2000-05-01

210

Trend of different molecular markers in the last decades for studying human migrations.  

PubMed

Anatomically modern humans are known to have widely migrated throughout history. Different scientific evidences suggest that the entire human population descended from just several thousand African migrants. About 85,000 years ago, the first wave of human migration was out of Africa, that followed the coasts through the Middle East, into Southern Asia via Sri Lanka, and in due course around Indonesia and into Australia. Another wave of migration between 40,000 and 12,000 years ago brought humans northward into Europe. However, the frozen north limited human expansion in Europe, and created a land bridge, "Bering land bridge", connecting Asia with North America about 25,000 years ago. Although fossil data give the most direct information about our past, it has certain anomalies. So, molecular archeologists are now using different molecular markers to trace the "most recent common ancestor" and also the migration pattern of modern humans. In this study, we have studied the trend of molecular markers and also the methodologies implemented in the last decades (2003-2014). From our observation, we can say that D-loop region of mtDNA and Y chromosome based markers are predominant. Nevertheless, mtDNA, especially the D-loop region, has some unique features, which makes it a more effective marker for tracing prehistoric footprints of modern human populations. Although, natural selection should also be taken into account in studying mtDNA based human migration. As per technology is concerned, Sanger sequencing is the major technique that is being used in almost all studies. But, the emergence of different cost-effective-and-easy-to-handle NGS platforms has increased its popularity over Sanger sequencing in studying human migration. PMID:25510397

Kundu, Sharbadeb; Ghosh, Sankar Kumar

2015-02-10

211

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

212

A denaturation study of human serum transferrin and apotransferrin  

E-print Network

A DENATURATION STUDY OF HUMAN SERUM TRANSFERRIN AND APOTRANSFERRIN A Thesis by HAROLD EDWIN KENNAH II Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... May 1970 Major Subjects Biochemistry and Biophysics A DENATURATION STUDY OF HUMAN SERUM TRANSFERRIN AND APOTRANSFERRIN A Thesis by HAROLD EDWIN KENNAH II Approved as to style and content bye Cha rman o omm ttee Head o De artment Member e...

Kennah, Harold Edwin

2012-06-07

213

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

E-print Network

Mine waste contamination limits soil respiration rates: a case study using quantile regression an environmental gradient. We quantified in situ soil respiration, pH, and heavy metal concentrations across a mine. Respiration values were monitored at study sites over 2 years. We used QR to show that soil respiration

Rilli, Matthias C.

214

Treatment-effect estimates adjusted for small-study effects via a limit meta-analysis.  

PubMed

Statistical heterogeneity and small-study effects are 2 major issues affecting the validity of meta-analysis. In this article, we introduce the concept of a limit meta-analysis, which leads to shrunken, empirical Bayes estimates of study effects after allowing for small-study effects. This in turn leads to 3 model-based adjusted pooled treatment-effect estimators and associated confidence intervals. We show how visualizing our estimators using the radial plot indicates how they can be calculated using existing software. The concept of limit meta-analysis also gives rise to a new measure of heterogeneity, termed G(2), for heterogeneity that remains after small-study effects are accounted for. In a simulation study with binary data and small-study effects, we compared our proposed estimators with those currently used together with a recent proposal by Moreno and others. Our criteria were bias, mean squared error (MSE), variance, and coverage of 95% confidence intervals. Only the estimators arising from the limit meta-analysis produced approximately unbiased treatment-effect estimates in the presence of small-study effects, while the MSE was acceptably small, provided that the number of studies in the meta-analysis was not less than 10. These limit meta-analysis estimators were also relatively robust against heterogeneity and one of them had a relatively small coverage error. PMID:20656692

Rücker, Gerta; Schwarzer, Guido; Carpenter, James R; Binder, Harald; Schumacher, Martin

2011-01-01

215

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

NASA Astrophysics Data System (ADS)

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.

Tsui, Lap-Chee

2003-04-01

216

Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario  

NASA Astrophysics Data System (ADS)

In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

Chen, Xi Lin; De Santis, Valerio; Esai Umenei, Aghuinyue

2014-07-01

217

Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.  

PubMed

In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. PMID:24889372

Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

2014-07-01

218

Foot Pain and Mobility Limitations in Older Adults: The Framingham Foot Study  

PubMed Central

Background. Foot pain is very common in the general population and has been shown to have a detrimental impact on health-related quality of life. This is of particular concern in older people as it may affect activities of daily living and exacerbate problems with balance and gait. The objective of this study is to evaluate the independent relationships between foot pain and mobility limitation in a population of community-dwelling older adults. Methods. Population-based cross-sectional study. Participants (n = 1,544) from the Framingham Foot Study (2002–2008) were assessed for physical performance. Foot pain was documented using the question “On most days, do you have pain, aching, or stiffness in either foot?” Mobility limitation was assessed using the Short Physical Performance Battery, dichotomized using 1–9 as an indicator of mobility limitation and 10–12 as no mobility limitation. Results. Foot pain was reported by 19% of men and 25% of women. After adjusting for age, obesity, smoking status, and depression, foot pain was significantly associated with mobility limitation in both men (odds ratio = 2.00, 95% confidence interval 1.14 – 3.50; p = .016) and women (odds ratio = 1.59, 95% confidence interval 1.03 – 2.46; p = .037). Conclusion. In our study of older adults from the Framingham Foot Study, foot pain was associated with an increased odds of having mobility limitation in both men and women. Clinicians should consider assessment of foot pain in general examinations of older adults who are at risk of mobility limitation. PMID:23704204

2013-01-01

219

Human Ecology. Study Guide and Course Outline.  

ERIC Educational Resources Information Center

An inservice course offered to elementary and secondary teachers and other concerned citizens in Rhode Island was presented in fifteen television programs. This study guide includes a description of the fifteen sessions. For each there is given a brief introduction and summary, an outline, questions for further study, and a bibliography of…

Zaki, Gamal

220

ACCEPTABLE HUMANITIES (HU) COURSES * African Studies  

E-print Network

Classical Studies Any CG or CL course EXCEPT Directed Studies and the following courses: CAS CL 111, 112 Representing Boston CAS EN 130 Literature and Science CAS EN 141 Literary Types: Fiction CAS EN 142 Literary in Shakespeare CAS EN 175 Literature and the Art of Film History of Art and Architecture All 100-, 200-, and 300

221

ACCEPTABLE HUMANITIES (HU) COURSES * African American Studies  

E-print Network

: 1960s to Present Classical Studies Any CG or CL course EXCEPT Directed Studies and the following Types: Fiction CAS EN 142 Literary Types: Poetry CAS EN 143 Literary Types: Drama CAS EN 163 Readings in Shakespeare CAS EN 164 Readings in Shakespeare CAS EN 175 Literature and the Art of Film History of Art

222

Electron tomography study of isolated human centrioles.  

PubMed

Centrioles are components of the centrosome, which is present in most eukaryotic cells (from protozoa to mammals). They organize the microtubule skeleton during interphase and the mitotic spindle during cell division. In ciliate cells, centrioles form basal bodies that are involved in cellular motility. Despite their important roles in biology, the detailed structure of centrioles remains obscure. This work contributes to a more complete model of centriole structure. The authors used electron tomography of isolated centrosomes from the human lymphoblast KE37 to explore the details of subdistal appendages and centriole lumen organization in mother centrioles. Their results reveal that each of the nine subdistal appendages is composed of two halves (20 nm diameter each) fused in a 40 nm tip that extends 100 nm from where it anchors to microtubules. The centriole lumen is filled at the distal domain by a 45 nm periodic stack of rings. Each ring has a 30 nm diameter, is 15 nm thick, and appears to be tilted at 53 degrees perpendicular to the centriole axis. The rings are anchored to microtubules by arms. Based on their results, the authors propose a model of the mother centriole distal structure. PMID:18837435

Ibrahim, Rana; Messaoudi, Cédric; Chichon, Francisco Javier; Celati, Claude; Marco, Sergio

2009-01-01

223

Quantifying the performance limits of human saccadic targeting during visual search  

NASA Technical Reports Server (NTRS)

In previous studies of saccadic targeting, the issue how visually guided saccades to unambiguous targets are programmed and executed has been examined. These studies have found different degrees of guidance for saccades depending on the task and task difficulty. In this study, we use ideal-observer analysis to estimate the visual information used for the first saccade during a search for a target disk in noise. We quantitatively compare the performance of the first saccadic decision to that of the ideal observer (ie absolute efficiency of the first saccade) and to that of the associated final perceptual decision at the end of the search (ie relative efficiency of the first saccade). Our results show, first, that at all levels of salience tested, the first saccade is based on visual information from the stimulus display, and its highest absolute efficiency is approximately 20%. Second, the efficiency of the first saccade is lower than that of the final perceptual decision after active search (with eye movements) and has a minimum relative efficiency of 19% at the lowest level of saliency investigated. Third, we found that requiring observers to maintain central fixation (no saccades allowed) decreased the absolute efficiency of their perceptual decision by up to a factor of two, but that the magnitude of this effect depended on target salience. Our results demonstrate that ideal-observer analysis can be extended to measure the visual information mediating saccadic target-selection decisions during visual search, which enables direct comparison of saccadic and perceptual efficiencies.

Eckstein, M. P.; Beutter, B. R.; Stone, L. S.

2001-01-01

224

Human olfactory consciousness and cognition: its unusual features may not result from unusual functions but from limited neocortical processing resources  

PubMed Central

Human and animal olfactory perception is shaped both by functional demands and by various environmental constraints seemingly peculiar to chemical stimuli. These demands and constraints may have generated a sensory system that is cognitively distinct from the major senses. In this article we identify these various functional demands and constraints, and examine whether they can be used to account for olfaction's unique cognitive features on a case-by-case basis. We then use this as grounds to argue that specific conscious processes do have functional value, a finding that naturally emerges when a comparative approach to consciousness across the senses is adopted. More generally, we conclude that certain peculiar features of olfactory cognition may owe more to limited neocortical processing resources, than they do to the challenges faced by perceiving chemical stimuli. PMID:24198808

Stevenson, Richard J.; Attuquayefio, Tuki

2013-01-01

225

Religious Studies The School of Humanities  

E-print Network

, normative, and sociocultural approaches to the study of religion) and religious traditions (Africanreligions,Buddhism,Christianity,comparativereligions,Hinduism,Islam hours (24 for double-majors) must include the following requirements: ·RELI 101 Introduction to Religion

Richards-Kortum, Rebecca

226

German Studies The School of Humanities  

E-print Network

Enlightenment and Romanticism, 1750­1850 · GERM306Realism to Modernity, 1850­present · 4German300-levelcoursesGerman through Cultural Texts · GERM305Enlightenment and Romanticism, 1750­1850 #12;German Studies 193

Richards-Kortum, Rebecca

227

German Studies The School of Humanities  

E-print Network

level, as follows: · GERM304German through Cultural Texts · GERM305Enlightenment and Romanticism, 1750 · GERM305Enlightenment and Romanticism, 1750­1850 #12;2 Departments / German Studies · GERM306Realism

Richards-Kortum, Rebecca

228

Human cystic echinococcosis in Kyrgystan: an epidemiological study  

Microsoft Academic Search

Human cystic echinococcosis (CE), caused by Echinococcus granulosus, is an emerging disease in central Asia. This study examined official data on the incidence of CE between 1991 and 2000 and studied routine hospital records in the main surgical hospitals in Bishkek, Kyrgystan, between 1990 and 2000. In addition, a cross-sectional ultrasound study of a rural population was undertaken in northern

P. R Torgerson; R. R Karaeva; N Corkeri; T. A Abdyjaparov; O. T Kuttubaev; B. S Shaikenov

2003-01-01

229

Impact of Design Trade Studies on System Human Resources.  

ERIC Educational Resources Information Center

This study focused on two objectives. The first objective was to identify and classify the characteristics of conceptual design trade studies that have high potential impact on human resource requirements of Air Force weapon systems. The approach used was a case history review and analysis of 129 F-15 aircraft design trade studies. The analysis…

Whalen, Gary V.; Askren, William B.

230

Noncanonical NOTCH Signaling Limits Self-Renewal of Human Epithelial and Induced Pluripotent Stem Cells through ROCK Activation  

PubMed Central

NOTCH plays essential roles in cell fate specification during embryonic development and in adult tissue maintenance. In keratinocytes, it is a key inducer of differentiation. ROCK, an effector of the small GTPase Rho, is also implicated in keratinocyte differentiation, and its inhibition efficiently potentiates immortalization of human keratinocytes and greatly improves survival of dissociated human pluripotent stem cells. However, the molecular basis for ROCK activation is not fully established in these contexts. Here we provide evidence that intracellular forms of NOTCH1 trigger the immediate activation of ROCK1 independent of its transcriptional activity, promoting differentiation and resulting in decreased clonogenicity of normal human keratinocytes. Knockdown of NOTCH1 abrogated ROCK1 activation and conferred sustained clonogenicity upon differentiation stimuli. Treatment with a ROCK inhibitor, Y-27632, or ROCK1 silencing substantially rescued the growth defect induced by activated NOTCH1. Furthermore, we revealed that impaired self-renewal of human induced pluripotent stem cells upon dissociation is, at least in part, attributable to NOTCH-dependent ROCK activation. Thus, the present study unveils a novel NOTCH-ROCK pathway critical for cellular differentiation and loss of self-renewal capacity in a subset of immature cells. PMID:24019071

Yugawa, Takashi; Nishino, Koichiro; Ohno, Shin-ichi; Nakahara, Tomomi; Fujita, Masatoshi; Goshima, Naoki; Umezawa, Akihiro

2013-01-01

231

Space station human productivity study, volume 1  

NASA Technical Reports Server (NTRS)

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.

1985-01-01

232

Animal models are reliably mimicking human diseases? A morphological study that compares animal with human NAFLD.  

PubMed

Non-alcoholic fatty liver disease (NAFLD) is a clinical-pathological syndrome that includes a wide spectrum of morphological alterations. In research, animal models are crucial in evaluating not only the pathogenesis of NAFLD and its progression, but also the therapeutic effects of various agents. Investigations on the ultrastructural features of NAFLD in humans are not copious, due to the difficulty to obtain human samples and to the long time of NAFLD to evolve. Translational comparative studies on the reliability of animal models in representing the histopathologic picture as seen in humans are missing. To overcome this lack of investigations, we compared the ultrastructural NAFLD features of an animal model versus human. Sprague-Dawley rats were fed with a high fat diet (HFD) for 1-4 weeks, while control rats were fed with a standard diet. Human specimens were collected from patients with diagnosed fatty liver disease, undergoing liver biopsies or surgery. Rat and human samples were examined by light microscopy and by transmission and high resolution scanning electron microscopy. The present work demonstrated that NAFLD in animal model and in human, share overlapping ultrastructural features. In conclusion, animal HFD represent an appropriate tool in studying the pathogenesis of NAFLD. PMID:25044260

Solinas, Paola; Isola, Michela; Lilliu, Maria Alberta; Conti, Gabriele; Civolani, Alberto; Demelia, Luigi; Loy, Francesco; Isola, Raffaella

2014-10-01

233

Functional Studies of Yeast-Expressed Human Heart Muscle Carnitine Palmitoyltransferase I  

Microsoft Academic Search

Long-chain fatty acids are the primary source of energy production in the heart. Carnitine palmitoyltrans- ferase I (CPT-I) catalyzes the first reaction in the transport of long-chain fatty acids from the cytoplasm to the mitochondrion, a rate-limiting step in ?-oxidation. In this study, we report the functional expression of the human heart\\/skeletal muscle isoform of CPT-I (M-CPT-I) in the yeastPichia

Hongfa Zhu; Jianying Shi; Ynskje de Vries; Dennis N. Arvidson; James M. Cregg; Gebre Woldegiorgis

1997-01-01

234

Measuring human-error probabilities in drug preparation: a pilot simulation study  

Microsoft Academic Search

Objectives  Designing a safe medication process requires the ability to model its reliability using methods such as probabilistic risk\\u000a assessment (PRA). However, lack of data, especially on human-error probabilities (HEPs), limits its use. To assess whether\\u000a small-scale simulations could help generate HEP data, a pilot study was conducted among nurses and anaesthetists. It focused\\u000a on two core activities, namely, the manual

P. Garnerin; B. Pellet-Meier; P. Chopard; T. Perneger; P. Bonnabry

2007-01-01

235

German Studies The School of Humanities  

E-print Network

through Cultural Texts · GERM305Enlightenment and Romanticism, 1750­1850 · GERM306Realism to Modernity and Romanticism, 1750­1850 #12;2 Departments / German Studies · GERM306Realism to Modernity, 1850­present · Three

Richards-Kortum, Rebecca

236

Anthropometric growth study of normal human auricle  

Microsoft Academic Search

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

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

2003-01-01

237

Implications of limits of detection of various methods for Bacillus anthracis in computing risks to human health.  

PubMed

Used for decades for biological warfare, Bacillus anthracis (category A agent) has proven to be highly stable and lethal. Quantitative risk assessment modeling requires descriptive statistics of the limit of detection to assist in defining the exposure. Furthermore, the sensitivities of various detection methods in environmental matrices are vital information for first responders. A literature review of peer-reviewed journal articles related to methods for detection of B. anthracis was undertaken. Articles focused on the development or evaluation of various detection approaches, such as PCR, real-time PCR, immunoassay, etc. Real-time PCR and PCR were the most sensitive methods for the detection of B. anthracis, with median instrument limits of detection of 430 and 440 cells/ml, respectively. There were very few peer-reviewed articles on the detection methods for B. anthracis in the environment. The most sensitive limits of detection for the environmental samples were 0.1 CFU/g for soil using PCR-enzyme-linked immunosorbent assay (ELISA), 17 CFU/liter for air using an ELISA-biochip system, 1 CFU/liter for water using cultivation, and 1 CFU/cm(2) for stainless steel fomites using cultivation. An exponential dose-response model for the inhalation of B. anthracis estimates of risk at concentrations equal to the environmental limit of detection determined the probability of death if untreated to be as high as 0.520. Though more data on the environmental limit of detection would improve the assumptions made for the risk assessment, this study's quantification of the risk posed by current limitations in the knowledge of detection methods should be considered when employing those methods in environmental monitoring and cleanup strategies. PMID:19648357

Herzog, Amanda B; McLennan, S Devin; Pandey, Alok K; Gerba, Charles P; Haas, Charles N; Rose, Joan B; Hashsham, Syed A

2009-10-01

238

Study of electrical properties of meridian on human body surface  

NASA Astrophysics Data System (ADS)

This paper presents the study of the subcutaneous electrical impedance on the human body surface. Measurements of the electrical impedance on five adult male subjects were carried out and analyzed for the possible detection of the acupuncture meridian lines of ancient Chinese medicine on the human body. The distribution of electrical impedance measured at 40 points over the volar side of the right upper limb of the subjects. The results show that electrical impedance varies at different locations of the human body surface, and the locations with lower electrical impedance coincide with the locations where the meridian is believed to exist.

Wang, Feng; Uematsu, Haruyuki; Otani, Nobuo

2007-12-01

239

Geometric morphometrics and virtual anthropology: advances in human evolutionary studies.  

PubMed

Geometric morphometric methods have been increasingly used in paleoanthropology in the last two decades, lending greater power to the analysis and interpretation of the human fossil record. More recently the advent of the wide use of computed tomography and surface scanning, implemented in combination with geometric morphometrics (GM), characterizes a new approach, termed Virtual Anthropology (VA). These methodological advances have led to a number of developments in human evolutionary studies. We present some recent examples of GM and VA related research in human evolution with an emphasis on work conducted at the University of Tübingen and other German research institutions. PMID:24818438

Rein, Thomas R; Harvati, Katerina

2014-01-01

240

Baboons as a model to study genetics and epigenetics of human disease.  

PubMed

A major challenge for understanding susceptibility to common human diseases is determining genetic and environmental factors that influence mechanisms underlying variation in disease-related traits. The most common diseases afflicting the US population are complex diseases that develop as a result of defects in multiple genetically controlled systems in response to environmental challenges. Unraveling the etiology of these diseases is exceedingly difficult because of the many genetic and environmental factors involved. Studies of complex disease genetics in humans are challenging because it is not possible to control pedigree structure and often not practical to control environmental conditions over an extended period of time. Furthermore, access to tissues relevant to many diseases from healthy individuals is quite limited. The baboon is a well-established research model for the study of a wide array of common complex diseases, including dyslipidemia, hypertension, obesity, and osteoporosis. It is possible to acquire tissues from healthy, genetically characterized baboons that have been exposed to defined environmental stimuli. In this review, we describe the genetic and physiologic similarity of baboons with humans, the ability and usefulness of controlling environment and breeding, and current genetic and genomic resources. We discuss studies on genetics of heart disease, obesity, diabetes, metabolic syndrome, hypertension, osteoporosis, osteoarthritis, and intrauterine growth restriction using the baboon as a model for human disease. We also summarize new studies and resources under development, providing examples of potential translational studies for targeted interventions and therapies for human disease. PMID:24174436

Cox, Laura A; Comuzzie, Anthony G; Havill, Lorena M; Karere, Genesio M; Spradling, Kimberly D; Mahaney, Michael C; Nathanielsz, Peter W; Nicolella, Daniel P; Shade, Robert E; Voruganti, Saroja; VandeBerg, John L

2013-01-01

241

Baboons as a Model to Study Genetics and Epigenetics of Human Disease  

PubMed Central

A major challenge for understanding susceptibility to common human diseases is determining genetic and environmental factors that influence mechanisms underlying variation in disease-related traits. The most common diseases afflicting the US population are complex diseases that develop as a result of defects in multiple genetically controlled systems in response to environmental challenges. Unraveling the etiology of these diseases is exceedingly difficult because of the many genetic and environmental factors involved. Studies of complex disease genetics in humans are challenging because it is not possible to control pedigree structure and often not practical to control environmental conditions over an extended period of time. Furthermore, access to tissues relevant to many diseases from healthy individuals is quite limited. The baboon is a well-established research model for the study of a wide array of common complex diseases, including dyslipidemia, hypertension, obesity, and osteoporosis. It is possible to acquire tissues from healthy, genetically characterized baboons that have been exposed to defined environmental stimuli. In this review, we describe the genetic and physiologic similarity of baboons with humans, the ability and usefulness of controlling environment and breeding, and current genetic and genomic resources. We discuss studies on genetics of heart disease, obesity, diabetes, metabolic syndrome, hypertension, osteoporosis, osteoarthritis, and intrauterine growth restriction using the baboon as a model for human disease. We also summarize new studies and resources under development, providing examples of potential translational studies for targeted interventions and therapies for human disease. PMID:24174436

Cox, Laura A.; Comuzzie, Anthony G.; Havill, Lorena M.; Karere, Genesio M.; Spradling, Kimberly D.; Mahaney, Michael C.; Nathanielsz, Peter W.; Nicolella, Daniel P.; Shade, Robert E.; Voruganti, Saroja; VandeBerg, John L.

2013-01-01

242

78 FR 71707 - MAP-21 Comprehensive Truck Size and Weight Limits Study Public Meeting and Outreach Sessions  

Federal Register 2010, 2011, 2012, 2013

...Comprehensive Truck Size and Weight Limits Study Public Meeting and Outreach Sessions AGENCY...Comprehensive Truck Size and Weight Limits Study. The Transportation Research Board Committee...Transportation (DOT) Truck Size and Weight Limits Study will hold a public meeting that will...

2013-11-29

243

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation.  

PubMed Central

The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain, for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy. PMID:7043913

Fabrikant, J. I.

1981-01-01

244

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

SciTech Connect

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.

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

245

Limiting Nonresponse in Longitudinal Research: Three Strategies for School-Based Studies. A RAND Note.  

ERIC Educational Resources Information Center

Longitudinal studies conducted with children typically experience non-response problems that can make substantial inroads on sample size and introduce bias into the analysis. Three methods for limiting non-response in school-based research programs were assessed: (1) asking parents to return consent forms only if they do not want their children to…

Ellickson, Phyllis L.

246

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

E-print Network

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 JavaScript

Anderson, Richard

247

Technical Manual for the Texas Successful Schools Study: Quality Education for Limited English Proficient Students.  

ERIC Educational Resources Information Center

The Texas Successful Schools Study examined the educational practices, school characteristics, and educator characteristics that contributed to the success of seven high-performing elementary schools with high proportions of limited-English-proficient (LEP) and economically disadvantaged students. This technical manual further elaborates the…

Texas Education Agency, Austin.

248

On the biogeography of salt limitation: A study of ant communities  

E-print Network

On the biogeography of salt limitation: A study of ant communities Michael Kasparia,b,1 , Stephen P, Balboa, Panama; cDepartment of Biology, University of Arkansas at Little Rock, Little Rock, AR 72204), butterflies (13), and bees (14) often search for ``salt licks'' (15) or resort to cannibalism (16) to maintain

Kaspari, Mike

249

Experimental and numerical study of flammability limits of gaseous mixtures in porous media  

Microsoft Academic Search

The present work deals with an experimental and numerical study of flammability limits for hydrocarbon–air mixtures in porous media and their dependence on the physical and geometrical properties of the solid phase. Experimental data have been obtained in a standard flammability apparatus modified through the insertion of a packed bed of spheres. Numerical data have been obtained through integration of

L di Mare; T. A Mihalik; G Continillo; J. H. S Lee

2000-01-01

250

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...

251

Scientific Study of Malnutrition as a Limiting Factor in the Development of Education.  

ERIC Educational Resources Information Center

This study on malnutrition as a limiting factor in the development of education (and, hence, in socioeconomic development generally) was presented to the UNESCO Seminar on Education, Nutrition, Agriculture and Man. The paper reports on recent research showing that the development of the central nervous system in very young children (including the…

Picasso de Oyague, Alfredo

252

COMPARATIVE KINETIC STUDIES OF NITRATE-LIMITED GROWTH AND NITRATE UPTAKE IN PHYTOPLANKTON IN CONTINUOUS CULTURE  

EPA Science Inventory

A comparative kinetic study of nitrate-limited growth and nitrate uptake was carried out in chemostat cultures of Ankistrodesmus falcatus, Asterionella formosa, Fragilaria crotonensis. In each species growth rate (microgram) was related to total cell nitrogen or cell quota (q) by...

253

Alternate Concentration Limit guidance together with two case studies demonstrating that guidance. Final report  

SciTech Connect

At the request of the Office of Solid Wastes (OSW), the SAB's Environmental Engineering Committee reviewed a draft Agency guidance for the establishment of Alternate Concentration Limits (ACL) for Resource Conservation and Recovery Act (RCRA) facilities, and two case studies demonstrating applications of the guidance. The Committee identified only obvious technical errors or omissions, which are explained in detail in the report.

Not Available

1986-03-01

254

Ecology and Human Values: A Course of Study. (Working Draft).  

ERIC Educational Resources Information Center

This interdisciplinary course is designed for senior year high school students in social studies and/or science. Its main thrust is the investigation of human values as they relate to the environment, although rooted in the natural sciences as a means of understanding the complexities inherent in the environment. Use is made of the case study

Wisconsin State Dept. of Public Instruction, Madison.

255

Faculty of Humanities and Social Sciences SCHOOL OF EDUCATION STUDIES  

E-print Network

of evaluation of education and training, development of web based learning and online learning environmentsFaculty of Humanities and Social Sciences SCHOOL OF EDUCATION STUDIES Lecturer in Digital Media /ICT and Education (5 Year Fixed Contract) Introduction The School of Education Studies is part

Humphrys, Mark

256

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...

257

An Experimental Study of the Emergence of Human Communication Systems  

Microsoft Academic Search

The emergence of human communication systems is typically investigated via 2 approaches with complementary strengths and weaknesses: naturalistic studies and computer simulations. This study was conducted with a method that combines these approaches. Pairs of participants played video games requiring communication. Members of a pair were physically separated but exchanged graphic signals through a medium that prevented the use of

Bruno Galantucci

2005-01-01

258

Repeated dose study of sucralose tolerance in human subjects  

Microsoft Academic Search

Two tolerance studies were conducted in healthy human adult volunteers. The first study was an ascending dose study conducted in eight subjects, in which sucralose was administered at doses of 1, 2.5, 5 and 10mg\\/kg at 48-hour intervals and followed by daily dosing at 2mg\\/kg for 3 days and 5mg\\/kg for 4 days. In the second study, subjects consumed either

I. McLean Baird; N. W. Shephard; R. J. Merritt; G. Hildick-Smith

2000-01-01

259

Perfluorochemicals and Human Semen Quality: The LIFE Study  

PubMed Central

Background: The relation between persistent environmental chemicals and semen quality is evolving, although limited data exist for men recruited from general populations. Objectives: We examined the relation between perfluorinated chemicals (PFCs) and semen quality among 501 male partners of couples planning pregnancy. Methods: Using population-based sampling strategies, we recruited 501 couples discontinuing contraception from two U.S. geographic regions from 2005 through 2009. Baseline interviews and anthropometric assessments were conducted, followed by blood collection for the quantification of seven serum PFCs (perfluorosulfonates, perfluorocarboxylates, and perfluorosulfonamides) using tandem mass spectrometry. Men collected a baseline semen sample and another approximately 1 month later. Semen samples were shipped with freezer packs, and analyses were performed on the day after collection. We used linear regression to estimate the difference in each semen parameter associated with a one unit increase in the natural log–transformed PFC concentration after adjusting for confounders and modeling repeated semen samples. Sensitivity analyses included optimal Box-Cox transformation of semen quality end points. Results: Six PFCs [2-(N-methyl-perfluorooctane sulfonamido) acetate (Me-PFOSA-AcOH), perfluorodecanoate (PFDeA), perfluorononanoate (PFNA), perfluorooctane sulfonamide (PFOSA), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA)] were associated with 17 semen quality end points before Box-Cox transformation. PFOSA was associated with smaller sperm head area and perimeter, a lower percentage of DNA stainability, and a higher percentage of bicephalic and immature sperm. PFDeA, PFNA, PFOA, and PFOS were associated with a lower percentage of sperm with coiled tails. Conclusions: Select PFCs were associated with certain semen end points, with the most significant associations observed for PFOSA but with results in varying directions. Citation: Buck Louis GM, Chen Z, Schisterman EF, Kim S, Sweeney AM, Sundaram R, Lynch CD, Gore-Langton RE, Barr DB. 2015. Perfluorochemicals and human semen quality: the LIFE Study. Environ Health Perspect 123:57–63;?http://dx.doi.org/10.1289/ehp.1307621 PMID:25127343

Chen, Zhen; Schisterman, Enrique F.; Kim, Sungduk; Sweeney, Anne M.; Sundaram, Rajeshwari; Lynch, Courtney D.; Gore-Langton, Robert E.; Barr, Dana Boyd

2014-01-01

260

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

PubMed Central

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

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

2013-01-01

261

GogB Is an Anti-Inflammatory Effector that Limits Tissue Damage during Salmonella Infection through Interaction with Human FBXO22 and Skp1  

PubMed Central

Bacterial pathogens often manipulate host immune pathways to establish acute and chronic infection. Many Gram-negative bacteria do this by secreting effector proteins through a type III secretion system that alter the host response to the pathogen. In this study, we determined that the phage-encoded GogB effector protein in Salmonella targets the host SCF E3 type ubiquitin ligase through an interaction with Skp1 and the human F-box only 22 (FBXO22) protein. Domain mapping and functional knockdown studies indicated that GogB-containing bacteria inhibited I?B degradation and NF?B activation in macrophages, which required Skp1 and a eukaryotic-like F-box motif in the C-terminal domain of GogB. GogB-deficient Salmonella were unable to limit NF?B activation, which lead to increased proinflammatory responses in infected mice accompanied by extensive tissue damage and enhanced colonization in the gut during long-term chronic infections. We conclude that GogB is an anti-inflammatory effector that helps regulate inflammation-enhanced colonization by limiting tissue damage during infection. PMID:22761574

Pilar, Ana Victoria C.; Reid-Yu, Sarah A.; Cooper, Colin A.; Mulder, David T.; Coombes, Brian K.

2012-01-01

262

Fraud Detection by Human Agents: A Pilot Study  

NASA Astrophysics Data System (ADS)

Fraud is a constant problem for online auction sites. Besides failures in detecting fraudsters, the currently employed methods yield many false positives: bona fide sellers that end up harassed by the auction site as suspects. We advocate the use of human computation (also called crowdsourcing) to improve precision and recall of current fraud detection techniques. To examine the feasibility of our proposal, we did a pilot study with a set of human subjects, testing whether they could distinguish fraudsters from common sellers before negative feedback arrived and looking just at a snapshot of seller profiles. Here we present the methodology used and the obtained results, in terms of precision and recall of human classifiers, showing positive evidence that detecting fraudsters with human computation is viable.

Almendra, Vinicius; Schwabe, Daniel

263

Insights from human studies into the host defense against candidiasis.  

PubMed

Candida spp. are the most common cause of mucosal and disseminated fungal infections in humans. Studies using mutant strains of mice have provided initial information about the roles of dectin-1, CARD9, and Th17 cytokines in the host defense against candidiasis. Recent technological advances have resulted in the identification of mutations in specific genes that predispose humans to develop candidal infection. The analysis of individuals with these mutations demonstrates that dectin-1 is critical for the host defense against vulvovaginal candidiasis and candidal colonization of the gastrointestinal tract. They also indicate that CARD9 is important for preventing both mucosal and disseminated candidiasis, whereas the Th17 response is necessary for the defense against mucocutaneous candidiasis. This article reviews the recent studies of genetic defects in humans that result in an increased susceptibility to candidiasis and discusses how these studies provide new insight into the host defense against different types of candidal infections. PMID:22015104

Filler, Scott G

2012-04-01

264

The Institute for the Interdisciplinary Study of Human & Machine Cognition  

NSDL National Science Digital Library

The Institute for the Interdisciplinary Study of Human & Machine Cognition (IHMC) is an interdisciplinary research unit of the University of West Florida. Researchers and staff at the IHMC investigate "a broad range of topics related to understanding cognition in both humans and machines with a particular emphasis on building computational tools to leverage and amplify human cognitive and perceptual capacities." Their work advances the study of human-centered computing, which takes a â??systems viewâ?ť to link human thought and action and technological systems. They are primarily interested in the analysis, design, and evaluation of computational aids or "cognitive prostheses." The website provides an overview of each of their current research areas, which include: knowledge modeling and sharing, adjustable autonomy, advanced interfaces and displays, communication and collaboration, computer-mediated learning systems, intelligent data understanding, software agents, expertise studies, work practice simulation, knowledge representation, and other related areas. They also provide Cmap Tools, a knowledge modeling software kit, which is free to download and "empowers users to construct, navigate, share, and criticize knowledge models represented as Concept Models." This site is also reviewed in the June 3, 2005.

265

Study of target heating induced by fast electrons in mass limited targets  

SciTech Connect

We studied the induced plasma heating in three different kind of targets: mass limited, foam targets and large mass targets. The experiment was performed at Alise laser facility of CEA/CESTA. The laser system emitted a {approx}1-ps pulse with {approx}10 J energy at a wavelength of {approx}1 {mu}m. Mass limited targets had three layers with thickness 10 {mu}m C{sub 8}H{sub 8}, 1 {mu}m C{sub 8}H{sub 7}Cl, 10 {mu}m C{sub 8}H{sub 8} with size 100 {mu}mx100 {mu}m. Detailed spectroscopic analysis of X-rays emitted from the Cl tracer showed that it was possible to heat up the plasma mass limited targets to a temperature {approx}250 eV with density {approx}10{sup 21} cm{sup -3}. The plasma heating is only produced by fast electron transport in the target, being the 10 {mu}m C{sub 8}H{sub 8} overcoating thick enough to prevent any possible direct irradiation of the tracer layer even taking into account mass-ablation due to the pre-pulse. These results demonstrate that with mass limited targets is possible to generate a plasma heated up to several hundreds eV. It is also very important for research concerning high energy density phenomena and for fast ignition (in particular for the study of fast electrons transport and induced heating).

Alessio, Morace; Dimitri, Batani; Renato, Redaelli [University of Milano Bicocca (Italy); Alexander, Magunov [General Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Claude, Fourment; Jorge, Santos Joao; Gerard, Malka [Universite de Bordeaux-CNRS-CEA, CELIA, Talence (France); Alain, Boscheron [CEA/CESTA Le BARP (France); Alexis, Casner [CEA-DAM, Bruyres-le-Chatel (France); Wigen, Nazarov [University of St. Andrews (United Kingdom); Tommaso, Vinci [CEA, Bruyeres le Chatel (France); Yasuaki, Okano; Yuichi, Inubushi; Hiroaki, Nishimura [Institute of Laser Engineering , Osaka University (Japan); Alessandro, Flacco [LOA, Ecole Polytechnique, Palaiseau (France); Chris, Spindloe; Martin, Tolley [RUTHERFORD Appleton Laboratory (United Kingdom)

2010-02-02

266

Paediatric palliative care: development and pilot study of a ‘Directory’ of life-limiting conditions  

PubMed Central

Background Children’s palliative care services are developing. Rational service development requires sound epidemiological data that are difficult to obtain owing to ambiguity in the definitions both of the population who needs palliative care and of palliative care itself. Existing definitions are of trajectory archetypes. The aim of this study was to develop and pilot a directory of the commonest specific diagnoses that map on to those archetypes. Methods The diagnoses of patients under the care of five children hospices and a tertiary specialist palliative medicine service in the UK were recorded. Duplicates and diagnoses that were not life-limiting conditions according to the ACT/RCPCH criteria or were not primary were removed. The resulting Directory of life-limiting conditions was piloted by analysing Death Certificate data of children in Wales between 2002 and 2007. Results 1590 diagnoses from children’s hospices and 105 from specialist palliative medicine were combined. After removals there were 376 diagnostic label. All ICD10 chapter headings were represented by at least one condition. The pilot study showed that 569 (54%) deaths in Wales were caused by LLC. Only four LLC resulted in ten or more deaths. Among deaths from LLC, the ten commonest diagnoses accounted for 32%, while the 136 diagnoses that caused one or two deaths accounted for 25%. The majority occurred from a small number of life-limiting conditions. Conclusion The Directory is a practical tool for identifying most life-limiting conditions using ICD10 codes that facilitates extraction and analysis of data from existing sources in respect of life-limiting conditions in children such as death certificate data, offering the potential for rapid and precise studies in paediatric palliative care. PMID:24330676

2013-01-01

267

Large prospective birth cohort studies on environmental contaminants and child health – Goals, challenges, limitations and needs  

PubMed Central

SUMMARY The adverse health effects of environmental contaminants (ECs) are a rising public health concern, and a major threat to sustainable socioeconomic development. The developing fetuses and growing children are particularly vulnerable to the adverse effects of ECs. However, assessing the health impact of ECs presents a major challenge, given that multiple outcomes may arise from one exposure, multiple exposures may result in one outcome, and the complex interactions between ECs, and between ECs, nutrients and genetic factors, and the dynamic temporal changes in EC exposures during the life course. Large-scale prospective birth cohort studies collecting extensive data and specimen starting from the prenatal or pre-conception period, although costly, hold promise as a means to more clearly quantify the health effects of ECs, and to unravel the complex interactions between ECs, nutrients and genotypes. A number of such large-scale studies have been launched in some developed counties. We present an overview of “why”, “what” and “how” behind these efforts with an objective to uncover major unidentified limitations and needs. Three major limitations were identified: (1) limited data and bio-specimens regarding early life EC exposure assessments in some birth cohort studies; (2) heavy participant burdens in some birth cohort studies may bias participant recruitment, and risk substantial loss to follow-up, protocol deviations limiting the quality of data and specimens collection, with an overall potential bias towards the null effect; (3) lack of concerted efforts in building comparable birth cohorts across countries to take advantage of natural “experiments” (large EC exposure level differences between countries) for more in-depth assessments of dose–response relationships, threshold exposure levels, and positive and negative effect modifiers. Addressing these concerns in current or future large-scale birth cohort studies may help to produce better evidence on the health effects of ECs. PMID:19765909

Luo, Zhong-Cheng; Liu, Jian-Meng; Fraser, William D.

2011-01-01

268

Different forms of human odor memory: a developmental study.  

PubMed

Recognizing odors is an important biological function, both in the animal kingdom as well as for humans. It has been debated whether there exist different forms of human odor memory. For verbal memory, the concept of recollection and familiarity for conscious and unconscious recognition is widely accepted. Here we introduce a similar model for human odor memory. We use a combination of an odor naming and odor recognition memory task to estimate the relationship between depth of processing and retention of olfactory information. A developmental approach with children, young adults, middle aged adults and elderly subjects was chosen in order to study the influence of age. Our results indicate the existence of two separable forms of odor memory depending on whether the odors were correctly or incorrectly named during the naming task. These two forms of odor memory were differently represented across the human age range. Intact familiarity-based memory was found in all age groups, whereas memory based on recollection was impaired in the elderly and not yet fully developed in children. Our data show, for the first time, two different forms of human odor memory across the human life span. PMID:10507532

Lehrner, J P; Walla, P; Laska, M; Deecke, L

1999-09-01

269

Lack of blood formate accumulation in humans following exposure to methanol vapor at the current permissible exposure limit of 200 ppm  

SciTech Connect

Accumulation of formate, the putative toxic metabolite of methanol, in the blood and the relationship between pulmonary intake and blood methanol concentration were investigated in six human volunteers following a 6-hr exposure to 200 ppm methanol (the current Occupational Safety and Health Administration 8-hr time-weighted average permissible exposure limit). At the end of a 6-hr exposure to 200 ppm methanol at rest, the blood methanol concentration was increased from a mean of 1.8 micrograms/mL to 7.0 micrograms/mL. Under light exercise, the total amount of methanol inhaled during the 6-hr exposure period was 1.8 times that inhaled at rest. However, no statistically significant increase in blood methanol concentration was observed under exercise: the concentrations averaged 8.1 micrograms/mL. Formate did not accumulate in the blood above its background level following the 6-hr exposures to 200 ppm methanol whether subjects were exposed at rest or during exercise. Unlike the data collected from epidemiologic studies, the authors' results were obtained under well-controlled methanol exposure conditions and by using appropriate dietary restrictions. The data show that (1) the biological load of methanol would be the same regardless of whether workers are engaged in light physical activity when they are exposed to methanol vapors below 200 ppm and (2) the formate that is associated with acute methanol toxicities in humans does not accumulate in blood when methanol exposure concentrations are below 200 ppm.

Lee, E.W.; Terzo, T.S.; D'Arcy, J.B.; Gross, K.B.; Schreck, R.M. (Biomedical Science Department, General Motors Research Laboratories, Warren, MI (United States))

1992-02-01

270

Intracellular Restraint: A New Basis for the Limitation in Response to Oxidative Stress in Human Erythrocytes Containing Low-Activity Variants of Glucose-6-Phosphate Dehydrogenase  

PubMed Central

Several mechanisms recently proposed for regulation of the hexose monophosphate shunt require the concentration of NADP to be low or that of NADPH to be high. The present study indicates that the first enzyme of the hexose monophosphate shunt of human erythrocytes is under severe restraint even when these conditions do not exist. In human erythrocytes containing low-activity variants of this enzyme, glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP+ 1-oxidoreductase; EC 1.1.1.49), measurements of the rate of oxidation of C-1 labeled glucose show that the enzyme is operating at a rate much closer to its maximum than in normal cells. This requires that the ratio of inhibitory NADPH to NADP be much lower in the variant cells than in normal cells. A small increase in oxidative rate, induced by naphthol, then causes a disappearance in reduced glutathione in the variant cells, presumably because a significant further decrease in NADPH occurs in these cells, whereas the same oxidative stress in normal cells would not lower the NADPH level appreciably. A low NADPH/NADP ratio in unstressed cells deficient in glucose-6-phosphate dehydrogenase is confirmed by direct measurement. The maximum activity of the variant enzyme in the cell, as measured with methylene blue to keep most of the NADP in the oxidized form, is only about 1/60 of that found in hemolysates, thus accounting for the failure to compensate for a relatively small oxidative stress in vivo in spite of an apparent sufficiency of enzyme. The reason for the limitation on maximum intracellular activity is unknown. A similar limitation is seen with normal cells incubated with methylene blue, where the maximum intracellular rate is also only about 1/60 of that found in hemolysates. PMID:4154443

Gaetani, Gianfranco D.; Parker, John C.; Kirkman, Henry N.

1974-01-01

271

Load transmission characteristics of limited carpal fusions: a two-dimensional finite element study.  

PubMed

Although limited carpal fusion is a choice of treatment in several wrist disorders, little is known about the biomechanics of these procedures, especially the loads carried by the ligaments. In a finite element study, four types of limited carpal fusions (scaphotrapeziotrapezoid, capitohamate, four corner fusion with and without scaphoid excision) were simulated and the loads carried by the ligaments were recorded. Measurements were repeated with and without implantation. The load transmission through the ligaments varied by the type of the fusion but, radioscaphoid and long radiolunate ligaments carried significantly more loads if not excised during the operation. Implantation did not affect the results in most cases. The model of the present study may be useful in preoperative planning. PMID:24974194

Bicen, A C; Gokdemir, H; Seber, S; Aydin, R; Gunal, I

2015-02-01

272

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

273

Studies on the tolerance limit of fluoride in food in China  

Microsoft Academic Search

To estimate the appropriate tolerance limit of fluoride in food in China, fluoride-related endemic diseases, background levels of fluoride in foods, and daily total intake of fluoride per capita were studied in addition to the subchronic toxicity test of fluoride in rats. In the general population, the daily total intake of fluoride from food, water, and air is 1.45-3.15 mg

S. L. Chen; Y. J. Gong; Y. G. Fu

1988-01-01

274

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

ERIC Educational Resources Information Center

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…

Man, Yiu-Kwong; Poon, Kin-Keung

2014-01-01

275

Meta-analyses of studies of the human microbiota  

PubMed Central

Our body habitat-associated microbial communities are of intense research interest because of their influence on human health. Because many studies of the microbiota are based on the same bacterial 16S ribosomal RNA (rRNA) gene target, they can, in principle, be compared to determine the relative importance of different disease/physiologic/developmental states. However, differences in experimental protocols used may produce variation that outweighs biological differences. By comparing 16S rRNA gene sequences generated from diverse studies of the human microbiota using the QIIME database, we found that variation in composition of the microbiota across different body sites was consistently larger than technical variability across studies. However, samples from different studies of the Western adult fecal microbiota generally clustered by study, and the 16S rRNA target region, DNA extraction technique, and sequencing platform produced systematic biases in observed diversity that could obscure biologically meaningful compositional differences. In contrast, systematic compositional differences in the fecal microbiota that occurred with age and between Western and more agrarian cultures were great enough to outweigh technical variation. Furthermore, individuals with ileal Crohn's disease and in their third trimester of pregnancy often resembled infants from different studies more than controls from the same study, indicating parallel compositional attributes of these distinct developmental/physiological/disease states. Together, these results show that cross-study comparisons of human microbiota are valuable when the studied parameter has a large effect size, but studies of more subtle effects on the human microbiota require carefully selected control populations and standardized protocols. PMID:23861384

Lozupone, Catherine A.; Stombaugh, Jesse; Gonzalez, Antonio; Ackermann, Gail; Wendel, Doug; Vázquez-Baeza, Yoshiki; Jansson, Janet K.; Gordon, Jeffrey I.; Knight, Rob

2013-01-01

276

Studying synapses in human brain with array tomography and electron microscopy  

PubMed Central

Postmortem studies of synapses in human brain are problematic due to the axial resolution limit of light microscopy and the difficulty preserving and analyzing ultrastructure with electron microscopy. Array tomography overcomes these problems by embedding autopsy tissue in resin and cutting ribbons of ultrathin serial sections. Ribbons are imaged with immunofluorescence, allowing high-throughput imaging of tens of thousands of synapses to assess synapse density and protein composition. The protocol takes approximately 3 days per case, excluding image analysis, which is done at the end of the study. Parallel processing for transmission electron microscopy (TEM) using a protocol modified to preserve structure in human samples allows complimentary ultrastructural studies. Incorporation of array tomography and TEM into brain banking is a potent way of phenotyping synapses in well-characterized clinical cohorts to develop clinico-pathological correlations at the synapse level. This will be important for research in neurodegenerative disease, developmental diseases, and psychiatric illness. PMID:23787894

Kay, Kevin R.; Smith, Colin; Wright, Ann K.; Serrano-Pozo, Alberto; Pooler, Amy M.; Koffie, Robert; Bastin, Mark E.; Bak, Thomas H.; Abrahams, Sharon; Kopeikina, Katherine J.; McGuone, Declan; Frosch, Matthew P.; Gillingwater, Thomas H.; Hyman, Bradley T.; Spires-Jones, Tara L.

2013-01-01

277

The Watershed as A Conceptual Framework for the Study of Environmental and Human Health  

PubMed Central

The watershed provides a physical basis for establishing linkages between aquatic contaminants, environmental health and human health. Current attempts to establish such linkages are limited by environmental and epidemiological constraints. Environmental limitations include difficulties in characterizing the temporal and spatial dynamics of agricultural runoff, in fully understanding the degradation and metabolism of these compounds in the environment, and in understanding complex mixtures. Epidemiological limitations include difficulties associated with the organization of risk factor data and uncertainty about which measurable endpoints are most appropriate for an agricultural setting. Nevertheless, it is our contention that an adoption of the watershed concept can alleviate some of these difficulties. From an environmental perspective, the watershed concept helps identify differences in land use and application of agrichemicals at a level of resolution relevant to human health outcomes. From an epidemiological perspective, the watershed concept places data into a construct with environmental relevance. In this perspectives paper, we discuss how the watershed can provide a conceptual framework for studies in environmental and human health. PMID:20508751

Kolok, Alan S.; Beseler, Cheryl L.; Chen, Xun-Hong; Shea, Patrick J.

2009-01-01

278

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

PubMed Central

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

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

1992-01-01

279

Studies of Inorganic Crystals in Biological Tissue: Magnetite in Human  

E-print Network

bacteria, polyplacophoran mollusks (chitons), salmons, tuna and recently tissues of the human brain bacteria and the chitons. Many studies have described that ferritin were related with cell proliferation crystals are extracted and identified include chitons (Mollucsan class: Polyplacophora) whose teeth consist

280

Sociology--the scientific study of society and human  

E-print Network

SOCIOLOGY Sociology--the scientific study of society and human interaction--is an opportunity to learn a great deal about yourself and the society around you. The Department of Sociology at Wichita. As a sociology major, you are required to take research methods, statistics and theory, plus 15 hours

281

Philosophic Processes and the Study of Human Moving.  

ERIC Educational Resources Information Center

A theoretical framework describing second-order philosophical processes that can be productive for human movement studies is presented. The processes of edification and theory building can clarify issues, expand viewpoints, and establish systematic ways of dealing with a phenomenon, leading to the more mature forms of dialogues and theories. (MT)

Bressan, Elizabeth S.; Pieter, Willy

1985-01-01

282

Study on Adaptive Kalman Filtering Algorithms in Human Movement Tracking  

E-print Network

Study on Adaptive Kalman Filtering Algorithms in Human Movement Tracking Yi Zhang Huosheng Hu to recover and improve their mobility toward normal life. This paper presents an adaptive Kalman filter and efficiency of the proposed adaptive algorithm is verified by simulation results. Index Terms - Kalman Filter

Hu, Huosheng

283

Preparing Global Citizens through the Study of Human Rights  

ERIC Educational Resources Information Center

The preparation of students for global citizenship represents a central challenge to social studies educators in the twenty-first century. Two-thirds of the world's poor are steeped in abject poverty and its grim consequences. The world refugee problem has reached staggering proportions. There is an international epidemic of human trafficking, and…

Kirkwood-Tucker, Toni Fuss

2012-01-01

284

Defibrination of Normal Human Blood for in vitro Cell Studies  

Microsoft Academic Search

DURING in vitro studies of drug action on purified red cells and lymphocytes, it became necessary to defibrinate normal human blood in a reproducible manner with minimal trauma. Two methods are commonly used for defibrination. The first involves mixing blood with glass beads in an airtight container, a procedure which may cause cell damage. When extended for 60 min at

J. D. Wilson; A. J. Grimes

1968-01-01

285

Asian Studies The School of Humanities and the School of  

E-print Network

Smith -- Fall Tani E. Barlow -- Spring AssociAte Directors Steven W. Lewis Richard J. Smith Professors106 Asian Studies The School of Humanities and the School of Social Sciences Directors Richard Tani E. Barlow Anne C. Klein Jeffrey J. Kripal Masayoshi Shibatani Richard J. Smith Stephen A. Tyler

Richards-Kortum, Rebecca

286

The Dating Game A Case Study in Human Evolution  

NSDL National Science Digital Library

In this role-playing case study, students attempt to determine the identity of a variety of human fossils based on characteristics described during a “quiz show.”  The case was designed to be used in a general biology class for freshman students where the focus is on evolution. It could also be used in an anthropology or paleontology course.

Shoshana Tobias

1999-01-01

287

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...

288

MAJOR: HUMAN DEVELOPMENT & FAMILY STUDIES (HDFS) EMPHASIS: CHILD LIFE  

E-print Network

MAJOR: HUMAN DEVELOPMENT & FAMILY STUDIES (HDFS) EMPHASIS: CHILD LIFE Minimum HDFS-CL Major Hours prerequisites: 1- FCS 2610 Understanding Children: Behavior & Guidance 2- FCS 2620 Child Development Practicum Development in Infancy and Early Childhood (BF) FCS 5230 Adolescent Development Pre-req: FCS 1500 or FCS 3215

Tipple, Brett

289

Roadmap: Human Development and Family Studies -Gerontology -Bachelor of Science  

E-print Network

Credit Hours] HDFS 24012 Child Development 3 See note 1 on page 2 BSCI 20020 Biological Structure only HDFS 44020 Adolescent Development 3 SOC 32210 Researching Society 3 Major Elective (lowerRoadmap: Human Development and Family Studies - Gerontology - Bachelor of Science [EH

Sheridan, Scott

290

Roadmap: Human Development and Family Studies -Gerontology -Bachelor of Science  

E-print Network

: [14 Credit Hours] HDFS 24012 Child Development 3 See note 1 on page 2 BSCI 20020 Biological Structure of Aging 3 Offered in fall only HDFS 44020 Adolescent Development 3 SOC 32210 Researching Society 3Roadmap: Human Development and Family Studies - Gerontology - Bachelor of Science [EH

Sheridan, Scott

291

Roadmap: Human Development and Family Studies Child and Youth Development -  

E-print Network

Child Development 3 See note 1 on page 2 HDFS 24013 Early Adolescence 3 Kent Core Requirements 3 SeeRoadmap: Human Development and Family Studies ­ Child and Youth Development - Bachelor of Science Semester Five: [15 Credit Hours] HDFS 44020 Adolescent Development 3 HDFS 44035 Assessment and Strategies

Sheridan, Scott

292

Mass Transfer Limited Enhanced Bioremediation at Dnapl Source Zones: a Numerical Study  

NASA Astrophysics Data System (ADS)

The success of enhanced bioremediation of dense non-aqueous phase liquids (DNAPLs) relies on accelerating contaminant mass transfer from the organic to the aqueous phase, thus enhancing the depletion of DNAPL source zones compared to natural dissolution. This is achieved by promoting biological activity that reduces the contaminant's aqueous phase concentration. Although laboratory studies have demonstrated that high reaction rates are attainable by specialized microbial cultures in DNAPL source zones, field applications of the technology report lower reaction rates and prolonged remediation times. One possible explanation for this phenomenon is that the reaction rates are limited by the rate at which the contaminant partitions from the DNAPL to the aqueous phase. In such cases, slow mass transfer to the aqueous phase reduces the bioavailability of the contaminant and consequently decreases the potential source zone depletion enhancement. In this work, the effect of rate limited mass transfer on bio-enhanced dissolution of DNAPL chlorinated ethenes is investigated through a numerical study. A multi-phase, multi-component groundwater transport model is employed to simulate DNAPL mass depletion for a range of source zone scenarios. Rate limited mass transfer is modeled by a linear driving force model, employing a thermodynamic approach for the calculation of the DNAPL - water interfacial area. Metabolic reductive dechlorination is modeled by Monod kinetics, considering microbial growth and self-inhibition. The model was utilized to identify conditions in which mass transfer, rather than reaction, is the limiting process, as indicated by the bioavailability number. In such cases, reaction is slower than expected, and further increase in the reaction rate does not enhance mass depletion. Mass transfer rate limitations were shown to affect both dechlorination and microbial growth kinetics. The complex dynamics between mass transfer, DNAPL transport and distribution, and dechlorination kinetics were reflected in a transient, spatially heterogeneous bioavailability number and dissolution enhancement. In agreement with the literature, source zone architecture largely determined the impact of mass transfer on potential dissolution enhancement, with bioavailability decreasing the most at high ganglia to pool ratios. The results of this study suggest that if mass transfer rate limitations are not considered in designing bioremediation applications at DNAPL source zones, the enhancement of DNAPL depletion and the overall effectiveness of enhanced bioremediation may be significantly overestimated.

Kokkinaki, A.; Sleep, B. E.

2011-12-01

293

Parametric studies of human thermal mechanisms and measurements.  

PubMed

A systematic methodology is proposed for mathematically quantifying the effects of measurement inaccuracies due to instrument uncertainty in a human calorimetry project. Human thermal mechanisms are poorly understood at the systems level and this study investigates the importance of these mechanisms quantitatively. The proposed methodology uses sensitivity derivatives combined with sensor accuracies to quantify the effect of each heat transfer mechanism contributing to the errors in the system equations. The method is applicable to any differentiable model to be validated by experimentation. To illustrate the methodology, two example cases, a reclining nude resting subject and a reclining clothed working subject, are analyzed. The calculated expected errors clearly suggest specific modifications. PMID:10763290

Thornton, S B; Nair, S S

2000-04-01

294

Simplified detection system for neuroreceptor studies in the human brain  

SciTech Connect

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.

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

295

13C MRS studies of neuroenergetics and neurotransmitter cycling in humans  

PubMed Central

In the last 25 years 13C MRS has been established as the only non invasive method for measuring glutamate neurotransmission and cell specific neuroenergetics. Although technically and experimentally challenging 13C MRS has already provided important new information on the relationship between neuroenergetics and neuronal function, energy cost of brain function, the high neuronal activity in the resting brain state, and how neuroenergetics and neurotransmitter cycling are altered in neurological and psychiatric disease. In this paper the current state of 13C MRS as it is applied to study neuroenergetics and neurotransmitter cycling in humans is reviewed. The focus is predominantly on recent findings in humans regarding metabolic pathways, applications to clinical research, and the technical status of the method. Results from in vivo 13C MRS studies in animals are discussed from the standpoint of validation of MRS measurements of neuroenergetics and neurotransmitter cycling and where they have helped identify key questions to address in human research. Controversies concerning the relation of neuroenergetics and neurotransmitter cycling and factors impacting accurate determination of fluxes through mathematical modeling are addressed. We further touch upon different 13C labeled substrates used to study brain metabolism, before reviewing a number of human brain diseases studied using 13C MRS. Future technological developments are discussed that will help to overcome limitations of 13C MRS with special attention on recent developments in hyperpolarized 13C MRS. PMID:21882281

Rothman, Douglas L.; De Feyter, Henk M.; de Graaf, Robin A.; Mason, Graeme F.; Behar, Kevin L.

2011-01-01

296

A study on human errors related to NPP maintenance activities  

Microsoft Academic Search

This experience-based study on human errors in nuclear power plant (NPP) maintenance used about 4400 maintenance history records and licensee event reports of an NPP from the years 1992-94 as its material. The aims of the study were to identify common cause failure mechanisms, allow statistical treatment and generate numerical safety indicators. About 30 dependent failures were identified for in-depth

P. Pyy; K. Laakso; L. Reiman

1997-01-01

297

Human factors study conducted in conjunction with a Mini-Round Robin assessment of ultrasonic technician performance  

Microsoft Academic Search

This report describes the findings from a limited human factors (HF) study conducted in conjunction with a Mini-Round Robin (MRR) held at the Pacific Northwest Laboratory. The purpose of the HF evaluation was to acquire preliminary data on performance shaping factors that affect ultrasonic testing (UT) reliability; to test the efficacy of relative operating characteristic analysis for representing UT accuracy;

W. A. Wheeler; W. L. Rankin; J. C. Spanner; R. V. Badalamente; T. T. Taylor

1986-01-01

298

Reconciling Human Smoking Behavior and Machine Smoking Patterns: Implications for Understanding Smoking Behavior and the Impact on Laboratory Studies  

PubMed Central

Introduction Recent Food and Drug Administration legislation enables the mandating of product performance standards for cigarette smoke and the evaluation of manufacturers’ health claims for modified tobacco products. Laboratory studies used for these evaluations, and also to understand tobacco smoke toxicology, use machines to generate smoke. The goal of this review is to critically evaluate methods to assess human smoking behavior and replicate this in the laboratory. Methods Smoking behavior and smoking machine studies were identified using PubMed and publically available databases for internal tobacco company documents. Results The smoking machine was developed to generate smoke to allow for comparing cigarette tar and nicotine yields. The intent was to infer relative human disease risk, but this concept was flawed because humans tailor their smoking to the product and chemical yields and toxicological effects change with different smoking profiles. While smoking machines also allow for mechanistic assessments of smoking-related diseases, the interpretations also are limited. However, available methods to assess how humans puff could be used to provide better laboratory assessments, but these need to be validated. Separately, the contribution of smoke mouth-holding and inhalation to dose need to be assessed, because these parts of smoking are not captured by the smoking machine. Better comparisons of cigarettes might be done by tailoring human puff profiles to the product based on human studies and comparing results across regimens. Conclusions There are major research gaps that limit the use of smoking machine studies for informing tobacco control regulation and mechanistic studies. PMID:19959678

Marian, Catalin; O'Connor, Richard J.; Djordjevic, Mirjana; Rees, Vaughan W.; Hatsukami, Dorothy K.; Shields, Peter G.

2009-01-01

299

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

E-print Network

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

Olsen, Stephen L.

300

Periodontitis is related to lung volumes and airflow limitation: a cross-sectional study.  

PubMed

This study aimed to assess the potential association of periodontal diseases with lung volumes and airflow limitation in a general adult population. Based on a representative population sample of the Study of Health in Pomerania (SHIP), 1463 subjects aged 25-86 years were included. Periodontal status was assessed by clinical attachment loss (CAL), probing depth and number of missing teeth. Lung function was measured using spirometry, body plethysmography and diffusing capacity of the lung for carbon monoxide. Linear regression models using fractional polynomials were used to assess associations between periodontal disease and lung function. Fibrinogen and high-sensitivity C-reactive protein (hs-CRP) were evaluated as potential intermediate factors. After full adjustment for potential confounders mean CAL was significantly associated with variables of mobile dynamic and static lung volumes, airflow limitation and hyperinflation (p<0.05). Including fibrinogen and hs-CRP did not change coefficients of mean CAL; associations remained statistically significant. Mean CAL was not associated with total lung capacity and diffusing capacity of the lung for carbon monoxide. Associations were confirmed for mean probing depth, extent measures of CAL/probing depth and number of missing teeth. Periodontal disease was significantly associated with reduced lung volumes and airflow limitation in this general adult population sample. Systemic inflammation did not provide a mechanism linking both diseases. PMID:23222882

Holtfreter, Birte; Richter, Stefanie; Kocher, Thomas; Dörr, Marcus; Völzke, Henry; Ittermann, Till; Obst, Anne; Schäper, Christoph; John, Ulrich; Meisel, Peter; Grotevendt, Anne; Felix, Stephan B; Ewert, Ralf; Gläser, Sven

2013-12-01

301

Synthesis and optical limiting studies of Au-doped TiO2 nanoparticles  

NASA Astrophysics Data System (ADS)

A series of Au-doped TiO2 nanoparticles with different Au concentrations were prepared by the sol–gel method using titanium (IV) isopropoxide and tetrachloroaurate (III) trihydrate as precursors. The framework substitution of Au in TiO2 nanoparticles was established by x-ray diffraction (XRD) and Fourier transform infrared (FT-IR) techniques. X-ray diffraction (XRD) and transmission electron microscopy (TEM) image results confirmed the anatase phase and nanocrystalline nature of TiO2–Au. The optical properties revealed an extended tailing of the absorption edge toward the visible region upon Au doping. The incorporation of Au in TiO2 was also confirmed by fluorescence quenching. The increase in Au doping enhanced the 'red-shift' in the UV-Vis absorption spectra. The spectral and nonlinear optical properties were studied using fluence-dependent transmittance measurements in order to reveal the optical limiting mechanism. The nonlinear optical response and optical limiting effects of TiO2–Au nanocomposites dispersed in ethylene glycol were studied at 532?nm using 5?ns Nd:YAG laser pulses. Effective three-photon absorption mechanisms play a major role for good optical limiting characteristics in these nanoparticles and it is seen that the optical nonlinearity enhances with lower threshold as the volume fraction of the Au concentration increased.

Mani Rahulan, K.; Ganesan, S.; Aruna, P.

2011-06-01

302

A Comparative Study Between Strain And Stress Based Forming Limit Analysis By Applying Several Phenomenological Yield Criteria  

SciTech Connect

The present work aims at analyzing a comparative study between the strain-based forming limit criterion (FLD) and the stress-based forming limit criterion (FLSD), under linear and complex strain paths. The selected material is an AA5182-0 aluminium alloy. Some relevant remarks about stress-based forming limit criterion concept are presented.

Butuc, Marilena C.; Vincze, Gabriela T.; Gracio, Jose J. [Centro de Tecnologia Mecanica e Automacao, Departamento de Engenharia Mecanica, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Barata da Rocha, A. [Departamento de Engenharia Mecanica, Universidade do Porto, Rua Dr. Roberto Frias, s/n 4200-465 Porto (Portugal)

2005-08-05

303

Studies of WW and WZ production and limits on anomalous WW? and WWZ couplings  

NASA Astrophysics Data System (ADS)

Evidence of anomalous WW and WZ production was sought in ppŻ collisions at a center-of-mass energy of s=1.8 TeV. The final states WW(WZ)-->?? jet jet+X, WZ-->??ee+X and WZ-->e?ee+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 WW? and WWZ couplings and were combined with our previous results. The combined 95% confidence level anomalous coupling limits for ?=2 TeV are -0.25<=??<=0.39 (?=0) and -0.18<=?<=0.19 (??=0), assuming the WW? couplings are equal to the WWZ couplings.

Abbott, B.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Akimov, V.; Alves, G. A.; Amos, N.; Anderson, E. W.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Baden, A.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Boswell, C.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chekulaev, S. V.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Coney, L.; Cooper, W. E.; Coppage, D.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Fatyga, M. K.; Feher, S.; Fein, D.; Ferbel, T.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Gavrilov, V.; Geld, T. L.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gibbard, B.; Gobbi, B.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J. A.; Greenlee, H.; Grinstein, S.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Tong; Ito, A. S.; Jerger, S. A.; Jesik, R.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kim, S. K.; Klima, B.; Klopfenstein, C.; Ko, W.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Landry, F.; Landsberg, G.; Leflat, A.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magańa-Mendoza, L.; Manankov, V.; Mani, S.; Mao, H. S.; Markeloff, R.; Marshall, T.; Martin, M. I.; Martin, R. D.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; Mostafa, M.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Norman, D.; Oesch, L.; Oguri, V.; Oshima, N.; Owen, D.; Padley, P.; Para, A.; Parashar, N.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Pawlik, B.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Reay, N. W.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sosebee, M.; Sotnikova, N.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stevenson, M. L.; Stichelbaut, F.; Stoker, D.; Stolin, V.; Stoyanova, D. A.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Toback, D.; Trippe, T. G.; Tuts, P. M.; Vaniev, V.; Varelas, N.; Varnes, E. W.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Wood, D. R.; Yamada, R.; Yamin, P.; Yasuda, T.

1999-10-01

304

A radiographic study of the detection limits of bone-cement remnants in total joint arthroplasty.  

PubMed

Management of an infected hip prosthesis typically requires that all associated cement be removed. In the absence of gross mantle loosening, the surgeon frequently resorts to intraoperative radiographs to assess the completeness of removal. For this reason, we undertook a study to determine limits of detection of retained cement by routine radiography. Polymethyl methacrylate bone-cement beads (Simplex-P; Stryker-Howmedica-Osteonics, Allendale, NJ) were fashioned into graduated sizes and placed within cadaver medullary canals using 2 different methods. Standard radiographic images were obtained. Individually and independently, we viewed these images and proposed the limit of resolution to be 2.4 to 3.2 mm. It is difficult to remove all cement based on radiographs alone. These results suggest a need to use techniques that permit visualization of the canal to ensure adequate cement removal. PMID:12478508

Rauh, Michael A; Bayers-Thering, Mary; Madanagopal, Sudhakar; Krackow, Kenneth A

2002-12-01

305

Transition state and rate-limiting step of the reaction catalyzed by the human dual-specificity phosphatase, VHR.  

PubMed

The dual-specificity phosphatases are unusual catalysts in that they can utilize protein substrates containing phosphotyrosine as well as phosphoserine/threonine. The dual-specificity phosphatases and the protein-tyrosine phosphatases (PTPases) share the active site motif (H/V)C(X)5R(S/T), but display little amino acid sequence identity outside of the active site. Although the dual-specificity phosphatases and the PTPases appear to bring about phosphate monoester hydrolysis through a similar mechanism, it is not clear what causes the difference in the active-site specificity between the two groups of enzymes. In this paper, we show that the human dual-specificity phosphatase, VHR [for VH1-Related; Ishibashi et al. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 12170-12174], is rather promiscuous toward small phosphate monoesters (including both aryl and alkyl phosphates of primary alcohols) with effectively identical kcat/Km and kcat values while the pKa values of the leaving groups (phenols or alcohols) varied from 7 to 16. Linear free-energy relationship analysis of kcat and kcat/Km of the enzyme-catalyzed hydrolysis reaction suggests that a uniform mechanism is utilized for both the aryl and alkyl substrates. The very small dependency of kcat/Km on the leaving group pKa can be accounted for by the protonation of the leaving group. Pre-steady-state burst kinetic analysis of the VHR-catalyzed hydrolysis of p-nitrophenyl phosphate provides direct kinetic evidence for the involvement of a phosphoenzyme intermediate in the dual specificity phosphatase-catalyzed reaction. The rate-limiting step for the VHR-catalyzed hydrolysis of p-nitrophenyl phosphate corresponds to the decomposition of the phosphoenzyme intermediate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8519766

Zhang, Z Y; Wu, L; Chen, L

1995-12-12

306

Life and Microgravity Sciences Spacelab Mission: Human Research Pilot Study  

NASA Technical Reports Server (NTRS)

The Life Sciences, Microgravity Science and Spacelab Mission contains a number of human experiments directed toward identifying the functional, metabolic and neurological characteristics of muscle weakness and atrophy during space flight. To ensure the successful completion of the flight experiments, a ground-based pilot study, designed to mimic the flight protocols as closely as possible, was carried out in the head-down tilt bed rest model. This report records the rationales, procedures, preliminary results and estimated value of the pilot study, the first of its kind, for 12 of the 13 planned experiments in human research. The bed rest study was conducted in the Human Research Facility at Ames Research Center from July 11 - August 28, 1995. Eight healthy male volunteers performed the experiments before, during and after 17 days bed rest. The immediate purposes of this simulation were to integrate the experiments, provide data in a large enough sample for publication of results, enable investigators to review individual experiments in the framework of a multi-disciplinary study and relay the experience of the pilot study to the mission specialists prior to launch.

Arnaud, Sara B. (Editor); Walker, Karen R. (Editor); Hargens, Alan (Editor)

1996-01-01

307

Uses of Remnant Human Lung Tissue for Mechanical Stretch Studies  

PubMed Central

Human lung tissue donated for research purposes is a precious resource which can enhance the exploration of mechanisms involved in ventilator-induced lung injury (VILI). The goal of this work was to establish methods and demonstrate the feasibility of obtaining viable primary human type I-like alveolar epithelial cells (AECs) from remnant tissue, even after a significant lapse in post-mortem time, as well as human precision-cut lung slices (PCLSs), and stretch them at magnitudes correlated with mechanical ventilation volumes. Although after 3 days in culture many of the isolated cells stained for the type II AEC marker pro-surfactant Protein C (pro-SPC), after 6 days in culture the monolayer stained only weakly and non-specifically for pro-SPC, and stained brightly for the type I AEC marker aquaporin-5. A strong zona-occludin 1 stain demonstrated the formation of tight junctions between the cells in the epithelial monolayer after only 3 days in culture. To demonstrate the utility of the preparations for the study of lung injury, we stretched the cells and the PCLSs cyclically, uniformly, and equibiaxially and quantified their viability. Our data show that the described methods allow the utilization of human tissue in in vitro stretch studies investigating VILI. PMID:23833689

Davidovich, N.; Chhour, P.; Margulies, S. S.

2013-01-01

308

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

ERIC Educational Resources Information Center

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…

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

2006-01-01

309

A validation study of a stochastic model of human interaction  

NASA Astrophysics Data System (ADS)

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.

Burchfield, Mitchel Talmadge

310

Longitudinal analysis of T cell receptor (TCR) gene usage by human immunodeficiency virus 1 envelope-specific cytotoxic T lymphocyte clones reveals a limited TCR repertoire  

PubMed Central

Human immunodeficiency virus 1 (HIV-1) infection is associated with a vigorous cellular immune response that allows detection of cytotoxic T lymphocyte (CTL) activity using freshly isolated peripheral blood mononuclear cells (PBMC). Although restricting class I antigens and epitopes recognized by HIV-1-specific CTL have been defined, the effector cells mediating this vigorous response have been characterized less well. Specifically, no studies have addressed the breadth and duration of response to a defined epitope. In the present study, a longitudinal analysis of T cell receptor (TCR) gene usage by CTL clones was performed in a seropositive person using TCR gene sequences as a means of tracking responses to a well-defined epitope in the glycoprotein 41 transmembrane protein. 10 CTL clones specific for this human histocompatibility leukocyte antigen-B14-restricted epitope were isolated at multiple time points over a 31-mo period. All clones were derived from a single asymptomatic HIV-1-infected individual with a vigorous response to this epitope that was detectable using unstimulated PBMC. Polymerase chain reaction amplification using V alpha and V beta family-specific primers was performed on each clone, followed by DNA sequencing of the V-D-J regions. All 10 clones utilized V alpha 14 and V beta 4 genes. Sequence analysis of the TCR revealed the first nine clones isolated to also be identical at the nucleotide level. The TCR-alpha junctional region sequence of the tenth clone was identical to the junctional region sequences of the other nine, but this clone utilized distinct D beta and J beta gene segments. This study provides evidence that the observed high degree of HIV-1-specific CTL activity may be due to monoclonal or oligoclonal expansion of specific effector cells, and that progeny of a particular CTL clone may persist for prolonged periods in vivo in the presence of a chronic productive viral infection. The observed limited TCR diversity against an immunodominant epitope may limit recognition of virus variants with mutations in regions interacting with the TCR, thereby facilitating immune escape. PMID:8145043

1994-01-01

311

Simulation study of melanoma detection in human skin tissues by laser-generated surface acoustic waves.  

PubMed

Air pollution has been correlated to an increasing number of cases of human skin diseases in recent years. However, the investigation of human skin tissues has received only limited attention, to the point that there are not yet satisfactory modern detection technologies to accurately, noninvasively, and rapidly diagnose human skin at epidermis and dermis levels. In order to detect and analyze severe skin diseases such as melanoma, a finite element method (FEM) simulation study of the application of the laser-generated surface acoustic wave (LSAW) technique is developed. A three-layer human skin model is built, where LSAW’s are generated and propagated, and their effects in the skin medium with melanoma are analyzed. Frequency domain analysis is used as a main tool to investigate such issues as minimum detectable size of melanoma, filtering spectra from noise and from computational irregularities, as well as on how the FEM model meshing size and computational capabilities influence the accuracy of the results. Based on the aforementioned aspects, the analysis of the signals under the scrutiny of the phase velocity dispersion curve is verified to be a reliable, a sensitive, and a promising approach for detecting and characterizing melanoma in human skin. PMID:25057963

Chen, Kun; Fu, Xing; Dorantes-Gonzalez, Dante J; Lu, Zimo; Li, Tingting; Li, Yanning; Wu, Sen; Hu, Xiaotang

2014-07-01

312

HUMAN BIOLOGYHUMAN BIOLOGYHUMAN BIOLOGY This major is designed for students seeking a focused course of study in human  

E-print Network

HUMAN BIOLOGYHUMAN BIOLOGYHUMAN BIOLOGY This major is designed for students seeking a focused course of study in human anatomy, physiology, metabolism, and/or evolution. The BS degree includes: Applied Physiology, Biomedical Sciences, Nutrition and Metabolism, and Human Evolutionary Biology. The BA

Rohs, Remo

313

The Influences of Genetic and Environmental Factors on Methylome-wide Association Studies for Human Diseases.  

PubMed

DNA methylation (DNAm) is an essential epigenetic mechanism for normal development, and its variation may be associated with diseases. High-throughput technology allows robust measurement of DNA methylome in population studies. Methylome-wide association studies (MWAS) scan DNA methylome to detect new epigenetic loci affecting disease susceptibility. MWAS is an emerging approach to unraveling the mechanism linking genetics, environment, and human diseases. Here I review the recent studies of genetic determinants and environmental modifiers of DNAm, and the concept for partitioning genetic and environmental contribution to DNAm. These studies establish the correlation maps between genome and methylome, and enable the interpretation of epigenetic association with disease traits. Recent findings suggested that MWAS was a promising genomic method to identify epigenetic predictors accounting for unexplained disease risk. However, new study designs, analytical methods and shared resources need to be implemented to address the limitations and challenges in future epigenomic epidemiologic studies. PMID:25422794

Sun, Yan V

2014-12-01

314

The role of O6-alkylguanine DNA alkyltransferase in limiting nitrosourea-induced sister chromatid exchanges in proliferating human lymphocytes.  

PubMed

Although induction of sister chromatid exchanges (SCEs) following nitrosourea exposure may be greater during cell proliferation, the increase could be offset by the action of the DNA repair protein O6-alkylguanine DNA alkyltransferase (alkyltransferase). To evaluate these factors in resting and proliferating (phytohemagglutinin stimulated) human lymphocytes, we studied the effect of changes in alkyltransferase activity on 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU)-induced SCEs. Phytohemagglutinin stimulation resulted in induction of alkyltransferase activity (5.9 +/- 0.3 units, resting, versus 9.2 +/- 0.2 units, proliferating). In both resting and proliferating lymphocytes the alkyltransferase activity was inactivated by 85-88% after an 18-h exposure to 0.5 mM of the modified base O6methylguanine (O6mGua). However, 48 h after removal of O6mGua, proliferating lymphocytes recovered alkyltransferase activity while resting cells did not. In the absence of O6mGua, both resting and proliferating lymphocytes were equally sensitive to BCNU-induced SCEs. Following inactivation of the alkyltransferase by O6mGua, BCNU-induced SCEs were markedly increased, but the increase was much greater in resting than proliferating cells, 4-fold vs. 2.6-fold at each dose of BCNU (P less than 0.001). The factors providing partial protection against BCNU-induced SCEs in proliferating lymphocytes appear to include the proliferation-dependent increase in alkyltransferase activity and the ability of proliferating lymphocytes to rapidly recover alkyltransferase activity after its inactivation. Thus, the alkyltransferase appears to provide an important mechanism of resistance to SCE induction in human lymphocytes. PMID:2702633

Trey, J E; Gerson, S L

1989-04-15

315

40 CFR 26.1605 - Operation of the Human Studies Review Board.  

... 2014-07-01 false Operation of the Human Studies Review Board. 26.1605 Section...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and Completed Human Research § 26.1605 Operation of...

2014-07-01

316

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

Code of Federal Regulations, 2011 CFR

... 2011-07-01 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...

2011-07-01

317

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

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

318

40 CFR 26.1605 - Operation of the Human Studies Review Board.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Operation of the Human Studies Review Board. 26.1605 Section...PROTECTION AGENCY GENERAL PROTECTION OF HUMAN SUBJECTS Review of Proposed and Completed Human Research § 26.1605 Operation of...

2013-07-01

319

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

Code of Federal Regulations, 2012 CFR

... 2012-07-01 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...

2012-07-01

320

Drosophila as a genetic model for studying pathogenic human viruses  

PubMed Central

Viruses are infectious particles whose viability is dependent on the cells of living organisms, such as bacteria, plants, and animals. It is of great interest to discover how viruses function inside host cells in order to develop therapies to treat virally infected organisms. The fruit fly Drosophila melanogaster is an excellent model system for studying the molecular mechanisms of replication, amplification, and cellular consequences of human viruses. In this review, we describe the advantages of using Drosophila as a model system to study human viruses, and highlight how Drosophila has been used to provide unique insight into the gene function of several pathogenic viruses. We also propose possible directions for future research in this area. PMID:22177780

Hughes, Tamara T.; Allen, Amanda L.; Bardin, Joseph E.; Christian, Megan N.; Daimon, Kansei; Dozier, Kelsey D.; Hansen, Caom L.; Holcomb, Lisa M.; Ahlander, Joseph

2011-01-01

321

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

PubMed Central

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

Elwood, J M

1999-01-01

322

Tamoxifen experimental carcinogenicity studies: Implications for human effects  

SciTech Connect

Tamoxifen is an effective antiestrogen in the treatment of breast cancer and is considered highly safe. In recent years, several trials have been initiated in women to evaluate its potential for the prevention of breast cancer. Such long-term administration of a medication to healthy people requires a substantial degree of safety. This review examines experimental carcinogenicity and mechanistic studies on tamoxifen and the implications for human effects. 25 refs.

Williams, G.M. [American Health Foundation, Valhalla, NY (United States)

1995-02-01

323

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

PubMed

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 370nm 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)cm(2)/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 (532nm, 50mW) Nd:YAG laser and the limiting threshold values are found to be 22.7mW for 0.01M and 24.9mW for 0.03 and 0.05M LTB:Cu nanoparticles. PMID:25615676

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

2015-04-01

324

Distribution limits of Batrachochytrium dendrobatidis: a case study in the Rocky Mountains, USA.  

USGS Publications Warehouse

Knowledge of the environmental constraints on a pathogen is critical to predicting its dynamics and effects on populations. Batrachochytrium dendrobatidis (Bd), an aquatic fungus that has been linked with widespread amphibian declines, is ubiquitous in the Rocky Mountains. As part of assessing the distribution limits of Bd in our study area, we sampled the water column and sediments for Bd zoospores in 30 high-elevation water bodies that lacked amphibians. All water bodies were in areas where Bd has been documented from neighboring, lower-elevation areas. We targeted areas lacking amphibians because existence of Bd independent of amphibians would have both ecologic and management implications. We did not detect Bd, which supports the hypothesis that it does not live independently of amphibians. However, assuming a detection sensitivity of 59.5% (based on sampling of water where amphibians tested positive for Bd), we only had 95% confidence of detecting Bd if it was in > or =16% of our sites. Further investigation into potential abiotic reservoirs is needed, but our results provide a strategic step in determining the distributional and environmental limitations of Bd in our study region.

Hossack, B.R.; Muths, E.; Anderson, C.W.; Kirshtein, J.D.; Corn, P.S.

2009-01-01

325

Ten-dimensional anthropomorphic arm control in a human brain?machine interface: difficulties, solutions, and limitations  

NASA Astrophysics Data System (ADS)

Objective. In a previous study we demonstrated continuous translation, orientation and one-dimensional grasping control of a prosthetic limb (seven degrees of freedom) by a human subject with tetraplegia using a brain?machine interface (BMI). The current study, in the same subject, immediately followed the previous work and expanded the scope of the control signal by also extracting hand-shape commands from the two 96-channel intracortical electrode arrays implanted in the subject’s left motor cortex. Approach. Four new control signals, dictating prosthetic hand shape, replaced the one-dimensional grasping in the previous study, allowing the subject to control the prosthetic limb with ten degrees of freedom (three-dimensional (3D) translation, 3D orientation, four-dimensional hand shaping) simultaneously. Main results. Robust neural tuning to hand shaping was found, leading to ten-dimensional (10D) performance well above chance levels in all tests. Neural unit preferred directions were broadly distributed through the 10D space, with the majority of units significantly tuned to all ten dimensions, instead of being restricted to isolated domains (e.g. translation, orientation or hand shape). The addition of hand shaping emphasized object-interaction behavior. A fundamental component of BMIs is the calibration used to associate neural activity to intended movement. We found that the presence of an object during calibration enhanced successful shaping of the prosthetic hand as it closed around the object during grasping. Significance. Our results show that individual motor cortical neurons encode many parameters of movement, that object interaction is an important factor when extracting these signals, and that high-dimensional operation of prosthetic devices can be achieved with simple decoding algorithms. ClinicalTrials.gov Identifier: NCT01364480.

Wodlinger, B.; Downey, J. E.; Tyler-Kabara, E. C.; Schwartz, A. B.; Boninger, M. L.; Collinger, J. L.

2015-02-01

326

Ten-dimensional anthropomorphic arm control in a human brain-machine interface: difficulties, solutions, and limitations.  

PubMed

Objective. In a previous study we demonstrated continuous translation, orientation and one-dimensional grasping control of a prosthetic limb (seven degrees of freedom) by a human subject with tetraplegia using a brain-machine interface (BMI). The current study, in the same subject, immediately followed the previous work and expanded the scope of the control signal by also extracting hand-shape commands from the two 96-channel intracortical electrode arrays implanted in the subject's left motor cortex. Approach. Four new control signals, dictating prosthetic hand shape, replaced the one-dimensional grasping in the previous study, allowing the subject to control the prosthetic limb with ten degrees of freedom (three-dimensional (3D) translation, 3D orientation, four-dimensional hand shaping) simultaneously. Main results. Robust neural tuning to hand shaping was found, leading to ten-dimensional (10D) performance well above chance levels in all tests. Neural unit preferred directions were broadly distributed through the 10D space, with the majority of units significantly tuned to all ten dimensions, instead of being restricted to isolated domains (e.g. translation, orientation or hand shape). The addition of hand shaping emphasized object-interaction behavior. A fundamental component of BMIs is the calibration used to associate neural activity to intended movement. We found that the presence of an object during calibration enhanced successful shaping of the prosthetic hand as it closed around the object during grasping. Significance. Our results show that individual motor cortical neurons encode many parameters of movement, that object interaction is an important factor when extracting these signals, and that high-dimensional operation of prosthetic devices can be achieved with simple decoding algorithms. ClinicalTrials.gov Identifier: NCT01364480. PMID:25514320

Wodlinger, B; Downey, J E; Tyler-Kabara, E C; Schwartz, A B; Boninger, M L; Collinger, J L

2015-02-01

327

Benefit-sharing: an inquiry regarding the meaning and limits of the concept in human genetic research  

Microsoft Academic Search

The Human Genome Project and the related research and development activities have raised heated discussions around some very basic ethical and social issues. A much debated concern is that of justice in human genetic research and in possible applications, especially pertaining to questions of just benefit-sharing - who and based on what sort of argumentation has the right to require

KADRI SIMM

328

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

PubMed Central

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

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

2014-01-01

329

Studying the Human Immunome: The Complexity of Comprehensive Leukocyte Immunophenotyping  

PubMed Central

A comprehensive study of the cellular components of the immune system requires both deep and broad immunophenotyping of numerous cell populations in an efficient and practical manner. In this chapter, we describe the technical aspects of studying the human immunome using high-dimensional (15 color) fluorescence-based immunophenotyping. We focus on the technical aspects of polychromatic flow cytometry and the initial stages in developing a panel for comprehensive leukocyte immunophenotyping (CLIP). We also briefly discuss how this panel is being used and the challenges of encyclopedic analysis of these rich data sets. PMID:23975032

Biancotto, Angélique

2014-01-01

330

Modification of digital music files for use in human temporary threshold shift studies.  

PubMed

An exposure that is reproducible across clinical/laboratory environments, and appealing to subjects, is described here. Digital music files are level-equated within and across songs such that playlists deliver an exposure that is consistent across time. Modified music is more pleasant to listen to than pure tones or shaped noise, and closely follows music exposures subjects may normally experience. Multiple therapeutics reduce noise-induced hearing loss in animals but human trial design is complicated by limited access to noise-exposed subject populations. The development of standard music exposure parameters for temporary threshold shift studies would allow comparison of protection across agents with real-world relevant stimuli in human subjects. PMID:21974483

Le Prell, C G; Yang, Q; Harris, J G

2011-10-01

331

Wearable Networked Sensing for Human Mobility and Activity Analytics: A Systems Study  

PubMed Central

This paper presents implementation details, system characterization, and the performance of a wearable sensor network that was designed for human activity analysis. Specific machine learning mechanisms are implemented for recognizing a target set of activities with both out-of-body and on-body processing arrangements. Impacts of energy consumption by the on-body sensors are analyzed in terms of activity detection accuracy for out-of-body processing. Impacts of limited processing abilities in the on-body scenario are also characterized in terms of detection accuracy, by varying the background processing load in the sensor units. Through a rigorous systems study, it is shown that an efficient human activity analytics system can be designed and operated even under energy and processing constraints of tiny on-body wearable sensors.

Dong, Bo; Biswas, Subir

2014-01-01

332

FT-Raman spectroscopy study of human breast tissue  

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

333

Human V?2V?2 T cells limit breast cancer growth by modulating cell survival-, apoptosis-related molecules and microenvironment in tumors.  

PubMed

Innate immune system has been known to play an important role in inhibiting the malignant transformation, tumor progression and invasion. However, the mechanistic basis remains ambiguous. Despite polyclonality of human ?? T cells, V?2V?2 T cell subset was shown to recognize and limit the growth of various tumors at various degrees. The differential recognition of the tumor cells by V?2V?2 T cells are yet to be defined. Our study reveals that ?? T cells limit in vitro growth of most breast tumor cells, such as SkBr7 (HER2+), MCF7 (ER+) and MDA-MB-231 (ER-) by inhibiting their survival and inducing apoptosis, except BrCa-MZ01 (PR+) cells. To investigate detail mechanisms of antineoplastic effects, we found that cell death was associated with the surface expression levels of MICA/B and ICAM1. Molecular signaling analysis demonstrated that inhibition of cell growth by ?? T cells was associated with the lower expression levels of cell survival-related molecules such as AKT, ERK and concomitant upregulation of apoptosis-related molecules, such as PARP, cleaved caspase 3 and tumor suppressor genes PTEN and P53. However, opposite molecular signaling was observed in the resistant cell line after coculture with ?? T cells. In vivo, antineoplastic effects of ?? T cells were also documented, where tumor growth was inhibited due to the downregulation of survival signals, strong induction of apoptotic molecules, disruption of microvasculature and increased infiltration of tumor associated macrophages. These findings reveal that a complex molecular signaling is involved in ?? T cell-mediated antineoplastic effects. PMID:23595559

Aggarwal, Reeva; Lu, Jingwei; Kanji, Suman; Das, Manjusri; Joseph, Matthew; Lustberg, Maryam B; Ray, Alo; Pompili, Vincent J; Shapiro, Charles L; Das, Hiranmoy

2013-11-01

334

OBATOCLAX and ABT-737 Induce ER Stress Responses in Human Melanoma Cells that Limit Induction of Apoptosis  

PubMed Central

Anti-apoptotic Bcl-2 family proteins, in particular, Mcl-1, are known to play a critical role in resistance of human melanoma cells to induction of apoptosis by endoplasmic reticulum stress and other agents. The present study examined whether the BH3 mimetics, Obatoclax and ABT-737, which inhibit multiple anti-apoptotic Bcl-2 family proteins, would overcome resistance to apoptosis. We report that both agents induced a strong unfolded protein response (UPR) and that RNAi knockdown of UPR signalling proteins ATF6, IRE1? and XBP-1 inhibited Mcl-1 upregulation and increased sensitivity to the agents. These results demonstrate that inhibition of anti-apoptotic Bcl-2 proteins by Obatoclax and ABT-737 appears to elicit a protective feedback response in melanoma cells, by upregulation of Mcl-1 via induction of the UPR. We also report that Obatoclax, but not ABT-737, strongly induces autophagy, which appears to play a role in determining melanoma sensitivity to the agents. PMID:24367627

Wroblewski, David; Jiang, Chen Chen; Croft, Amanda; Farrelly, Margaret L.; Zhang, Xu Dong; Hersey, Peter

2013-01-01

335

Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion  

PubMed Central

Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs) related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA) increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion. PMID:22291969

Atkinson, Stuart P.; Quińonero, Alicia; Martínez, Sebastián; Pellicer, Antonio; Simón, Carlos

2012-01-01

336

Life Sciences Division and Center for Human Genome Studies  

SciTech Connect

This report summarizes the research and development activities of Los Alamos National Laboratories Life Sciences Division and biological aspects of the Center for Human Genome Studies for the calendar year 1991. Selected research highlights include: yeast artificial chromosome libraries from flow sorted human chromosomes 16 and 21; distances between the antigen binding sites of three murine antibody subclasses measured using neutron and x-ray scattering; NFCR 10th anniversary highlights; kinase-mediated differences found in the cell cycle regulation of normal and transformed cells; and detecting mutations that cause Gaucher's disease by denaturing gradient gel electrophoresis. Project descriptions include: genomic structure and regulation, molecular structure, cytometry, cell growth and differentiation, radiation biology and carcinogenesis, and pulmonary biology.

Spitzmiller, D.; Bradbury, M.; Cram, S. (comps.)

1992-05-01

337

An electron microscopic study of human olfactory mucosa.  

PubMed Central

Two intranasal biopsies of human olfactory mucosa were studied with the electron microscope, after confirming with the light microscope that they were in fact from the olfactory region. It was noted that the end of the dendrite of the human olfactory cell is flat or dome-shaped, and is not a bulb-like projection (olfactory vesicle). Moreover, the cilia are in the long axis of the olfactory cell, perpendicular to the epithelial surface, and do not lie parallel to it as described in some species. The supporting cells had multiple long microvilli, and definite points of contact with the olfactory cells; they appeared to spread their secretion over the microvilli in a novel manner, producing a layer of regularly spaced, spike-like granules. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:422486

Polyzonis, B M; Kafandaris, P M; Gigis, P I; Demetriou, T

1979-01-01

338

Simple instrument for biochemical studies of the living human brain  

SciTech Connect

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.

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

1986-09-01

339

Resveratrol: A review of preclinical studies for human cancer prevention  

SciTech Connect

The search for novel and effective cancer chemopreventive agents has led to the identification of various naturally occurring compounds one of which is resveratrol (trans-3,4',5-trihydroxystilbene), a phytoalexin derived from the skin of grapes and other fruits. Resveratrol is known to have potent anti-inflammatory and antioxidant effects and to inhibit platelet aggregation and the growth of a variety of cancer cells. Its potential chemopreventive and chemotherapeutic activities have been demonstrated in all three stages of carcinogenesis (initiation, promotion, and progression), in both chemically and UVB-induced skin carcinogenesis in mice, as well as in various murine models of human cancers. Evidence from numerous in vitro and in vivo studies has confirmed its ability to modulate various targets and signaling pathways. This review discusses the current preclinical and mechanistic data available and assesses resveratrol's anticancer effects to support its potential as an anticancer agent in human populations.

Athar, Mohammad; Back, Jung Ho; Tang Xiuwei [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States); Kim, Kwang Ho [Department of Dermatology, Hallym University College of Medicine (Korea, Republic of); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892 (United States); Bickers, David R. [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States); Kim, Arianna L. [Department of Dermatology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street VC15-204, New York, NY 10032 (United States)], E-mail: ak309@columbia.edu

2007-11-01

340

Federal Reserve Bank of Atlanta: Center for Human Capital Studies  

NSDL National Science Digital Library

Based at the Federal Reserve Bank of Atlanta, the Center for Human Capital Studies "intends to enhance the understanding of human capital development and labor market issues." On its page, visitors can learn about the centerâÂÂs annual reports, its Jobs Calculator, and various events and symposia. The Jobs Calculator calculates the net employment change needed to achieve a target unemployment rate after a specified number of months. Visitors can start by entering their own metrics to view statewide numbers or consult a list of FAQs for using the calculator. The centerâÂÂs newsletter and working papers can be found in the Publications area and the podcasts offer another great feature to the site. Podcast topics include "Economic Gardening: A Homegrown Approach to Growth" and "Help for Difficult to Employ Populations: Colocating Jobs and Training Opportunities.âÂÂ

341

Resveratrol and clinical trials: the crossroad from in vitro studies to human evidence.  

PubMed

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of foodstuffs such as grapes and red wine. Resveratrol has been reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol- based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of 'potential' benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called 'Resveratrol Paradox', i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently available evidence regarding resveratrol's effects on humans obtained from randomized clinical trials. In addition, we will provide a critical outlook for further research on this molecule that is evolving from a minor dietary compound to a possible multi-target therapeutic drug. PMID:23448440

Tomé-Carneiro, Joao; Larrosa, Mar; González-Sarrías, Antonio; Tomás-Barberán, Francisco A; García-Conesa, María Teresa; Espín, Juan Carlos

2013-01-01

342

Resveratrol and Clinical Trials: The Crossroad from In Vitro Studies to Human Evidence  

PubMed Central

Resveratrol (3,5,4’-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of food-stuffs such as grapes and red wine. Resveratrol has been reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol-based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of ‘potential’ benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called ‘Resveratrol Paradox’, i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently available evidence regarding resveratrol’s effects on humans obtained from randomized clinical trials. In addition, we will provide a critical outlook for further research on this molecule that is evolving from a minor dietary compound to a possible multi-target therapeutic drug. PMID:23448440

Tomé-Carneiro, Joao; Larrosa, Mar; González-Sarrías, Antonio; Tomás-Barberán, Francisco A.; García-Conesa, María Teresa; Espín, Juan Carlos

2013-01-01

343

Comparison of polychlorinated biphenyl levels across studies of human neurodevelopment.  

PubMed Central

Polychlorinated biphenyls (PCBs) are persistent pollutants that are ubiquitous in the food chain, and detectable amounts are in the blood of almost every person in most populations that have been examined. Extensive evidence from animal studies shows that PCBs are neurotoxins, even at low doses. Interpretation of human data regarding low-level, early-life PCB exposure and subsequent neurodevelopment is problematic because levels of exposure were not similarly quantified across studies. We expressed the exposure levels from 10 studies of PCB and neurodevelopment in a uniform manner using a combination of data from original investigators, laboratory reanalyses, calculations based on published data, and expert opinion. The mainstay of our comparison was the median level of PCB 153 in maternal pregnancy serum. The median concentration of PCB 153 in the 10 studies ranged from 30 to 450 ng/g serum lipid, and the median of the 10 medians was 110 ng/g. We found that (a)) the distribution of PCB 153 exposure in most studies overlapped substantially, (b)) exposure levels in the Faroe Islands study were about 3-4-fold higher than in most other studies, and (c)) the exposure levels in the two recent U.S. studies were about one-third of those in the four earlier U.S. studies or recent Dutch, German, and northern Québec studies. Our results will facilitate a direct comparison of the findings on PCBs and neurodevelopment when they are published for all 10 studies. PMID:12515680

Longnecker, Matthew P; Wolff, Mary S; Gladen, Beth C; Brock, John W; Grandjean, Philippe; Jacobson, Joseph L; Korrick, Susan A; Rogan, Walter J; Weisglas-Kuperus, Nynke; Hertz-Picciotto, Irva; Ayotte, Pierre; Stewart, Paul; Winneke, Gerhard; Charles, M Judith; Jacobson, Sandra W; Dewailly, Eric; Boersma, E Rudy; Altshul, Larisa M; Heinzow, Birger; Pagano, James J; Jensen, Allan A

2003-01-01

344

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

SciTech Connect

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.

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

1997-12-31

345

Improved Neuropsychological and Neurological Functioning Across Three Antiretroviral Regimens in Diverse Resource-Limited Settings: AIDS Clinical Trials Group Study A5199, the International Neurological Study  

PubMed Central

Background.?AIDS Clinical Trials Group (ACTG) A5199 compared the neurological and neuropsychological (NP) effects of 3 antiretroviral regimens in participants infected with human immunodeficiency virus type 1 (HIV-1) in resource-limited settings. Methods.?Participants from Brazil, India, Malawi, Peru, South Africa, Thailand, and Zimbabwe were randomized to 3 antiretroviral treatment arms: A (lamivudine-zidovudine plus efavirenz, n = 289), B (atazanavir, emtricitabine, and didanosine-EC, n = 293), and C (emtricitabine-tenofovir-disoproxil fumarate plus efavirenz, n = 278) as part of the ACTG PEARLS study (A5175). Standardized neurological and neuropsychological (NP) screening examinations (grooved pegboard, timed gait, semantic verbal fluency, and finger tapping) were administered every 24 weeks from February 2006 to May 2010. Associations with neurological and neuropsychological function were estimated from linear and logistic regression models using generalized estimating equations. Results.?The median weeks on study was 168 (Q1 = 96, Q3 = 192) for the 860 participants. NP test scores improved (P < .05) with the exception of semantic verbal fluency. No differences in neurological and neuropsychological functioning between treatment regimens were detected (P > .10). Significant country effects were noted on all NP tests and neurological outcomes (P < .01). Conclusions.?The study detected no significant differences in neuropsychological and neurological outcomes between randomized ART regimens. Significant improvement occurred in neurocognitive and neurological functioning over time after initiation of ARTs. The etiology of these improvements is likely multifactorial, reflecting reduced central nervous system HIV infection, better general health, and practice effects. This study suggests that treatment with either of the World Health Organization –recommended first-line antiretroviral regimens in resource-limited settings will improve neuropsychological functioning and reduce neurological dysfunction. Clinical trials registration. ?NCT00096824. PMID:22661489

Robertson, K.; Jiang, H.; Kumwenda, J.; Supparatpinyo, K.; Evans, S.; Campbell, T. B.; Price, R.; Tripathy, S.; Kumarasamy, N.; La Rosa, A.; Santos, B.; Silva, M. T.; Montano, S.; Kanyama, C.; Faesen, S.; Murphy, R.; Hall, C.; Marra, C. M.; Marcus, C.; Berzins, B.; Allen, R.; Housseinipour, M.; Amod, F.; Sanne, I.; Hakim, J.; Walawander, A.; Nair, A.

2012-01-01

346

Crowdsourcing and Human Computation: Systems, Studies and Platforms  

E-print Network

Crowdsourcing and human computation are transforming human-computer interaction, and CHI has led the way. The seminal publication in human computation was initially published in CHI in 2004 [1], and the first paper ...

Bernstein, Michael

2011-01-01

347

Disposition of Cremophor EL in humans limits the potential for modulation of the multidrug resistance phenotype in vivo.  

PubMed

The purpose of the present study was to characterize the distribution and elimination kinetics of the paclitaxel vehicle Cremophor EL (CrEL), a polyoxyethylated castor oil that can modulate P-glycoprotein-mediated multidrug resistance in vitro. The pharmacokinetics of CrEL were studied using noncompartmental models in 23 patients with histological proof of malignant solid tumors, receiving paclitaxel as a 3-h i.v. infusion at dose levels ranging from 100-225 mg/m2 (corresponding to CrEL doses of 8.33-18.8 ml/m2). Serial plasma samples were obtained before and up to 72 h after drug administration, and were analyzed for the presence of CrEL by a novel colorimetric dye-binding microassay. The area under the plasma concentration versus time curves and the peak plasma levels of CrEL increased from 253+/-36.8 (mean+/-SD) to 680+/- 180 microl.h/ml, and from 3.40+/-0.10 to 6.58+/-0.52 microl/ml, respectively, consistent with linear pharmacokinetics. Disappearance of CrEL from the central plasma compartment was characterized by a terminal elimination half-life of 84.1+/-20.4 h, resulting in extended persistence of substantial levels even at 1 week after paclitaxel treatment. The observed volume of distribution was extremely low and averaged 3.70+/-0.49 liters/m2, implying that the tumor delivery of CrEL is insignificant. Our results indicate that CrEL is a relatively slow clearance compound and that its distribution is limited to the central plasma compartment. Hence, CrEL is not likely to play a role in reversing P-glycoprotein-mediated multidrug resistance to paclitaxel in vivo. PMID:9717822

Sparreboom, A; Verweij, J; van der Burg, M E; Loos, W J; Brouwer, E; Viganň, L; Locatelli, A; de Vos, A I; Nooter, K; Stoter, G; Gianni, L

1998-08-01

348

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

PubMed Central

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

2013-01-01

349

Stratosphere and troposphere (S-T) studies at Millstone Hill. Recent results, capabilities and limitations  

NASA Technical Reports Server (NTRS)

The 440-MHz incoherent-scatter radar at Millstone Hill has been used in recent years for studies of the troposphere and lower stratosphere with a fully steerable 150' antenna. The configuration of the radar system is briefly outlined. Clear-air returns are received over an altitude range 4 to 25 km. The power spectra of these returns can be measured with a range resolution of up to 300 m and a Doppler resolution of up to 4 cm/sec. Due to the lack of a natural shield around the radar, the ground clutter at Millstone is more severe than at other installations. With the use of a fine Doppler resolution, however, the atmospheric returns are readily discriminated from the clutter. Observations of turbulence structures, spatial inhomogeneity of turbulence, and enhanced turbulence associated with convective phenomena are described. Capabilities and limitations of the Millstone S-T radar are pointed out.

Rastogi, P. K.

1983-01-01

350

Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides  

NASA Technical Reports Server (NTRS)

The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

1989-01-01

351

Preventable anesthesia mishaps: a study of human factors*  

PubMed Central

?? A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82%), with breathing-circuit disconnections, inadvertent changes in gas flow, and drug syringe errors being frequent problems. Overt equipment failures constituted only 14% of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia. PMID:12486995

Cooper, J.; Newbower, R.; Long, C.; McPeek, B.

2002-01-01

352

Interaction of pentylsarin analogues with human acetylcholinesterase: a kinetic study.  

PubMed

Previous kinetic studies investigating the interactions between human acetylcholinesterase (AChE), structurally different organophosphorus compounds (OP) and oximes did not reveal a conclusive structure-activity relationship of the different reactions. The only exception was for a homologous series of methylphosphonofluoridates bearing C1-C4 O-n- or O-i-alkyl residues. Hence, it was tempting to investigate the kinetic interactions between different pentylsarin analogues, human AChE and two oximes, obidoxime and HI 6, in order to increase the understanding of structure-activity relationship between highly toxic OP and human AChE. The rate constants for the inhibition of human erythrocyte AChE by four pentylsarin compounds (k(i)), for the spontaneous dealkylation (aging, k(a)) and reactivation (k(s)) of inhibited AChE as well as for the oxime-induced reactivation of inhibited AChE by obidoxime and HI 6 reflected by the dissociation constant (K(D)) and the reactivity constant (k(r)) were determined. All pentylsarin analogues had a high inhibitory potency towards AChE. Inhibited AChE was subject to spontaneous reactivation which outweighed aging substantially. Pentylsarin-inhibited AChE could be reactivated by oximes, HI 6 being more potent than obidoxime. The determination of inhibition, reactivation and aging kinetics of pentylsarin analogues with human AChE extends the database on interactions between AChE and methylphosphonofluoridate homologues with C1-C4 n- and i-alkyl residues demonstrating a structure-activity relationship depending on the chain length with certain differences regarding inhibition and post-inhibitory reactions. Unfortunately, no structure-activity relationship could be observed for the oxime-induced reactivation of inhibited AChE. In view of previous results with numerous structurally different organophosphates, organophosphonates and phosphoramidates it has to be concluded that up to now kinetic studies did not provide decisive information for the development of more effective oxime-based reactivators. PMID:19429253

Worek, F; Herkert, N M; Koller, M; Aurbek, N; Thiermann, H

2009-06-01

353

Mössbauer studies of electrophoretically purified monoferric and diferric human transferrin  

Microsoft Academic Search

Summary Electrophoretically purified57Fe-enriched monoferric and diferric human transferrins and selectively labeled complexes ([C-56Fe,N-57Fe]transferrin and [C-57Fe,N-56Fe]transferrin) were studied by Mössbauer spectroscopy. The data were recorded at 4.2 K over a wide range of applied magnetic fields (0.05–6 T) and were analyzed by a spin-Hamiltonian formalism. Characteristic hyperfine parameters were found and the obtained zero-field splitting parameters (D=0.25±0.05 cm-1 andE\\/D = 0.30

Suzanne A. Kretchmar; Miguel Teixeira; Boi-Hank Huynh; Kenneth N. Raymond

1988-01-01

354

Fructose metabolism in humans – what isotopic tracer studies tell us  

PubMed Central

Fructose consumption and its implications on public health are currently under study. This work reviewed the metabolic fate of dietary fructose based on isotope tracer studies in humans. The mean oxidation rate of dietary fructose was 45.0%?±?10.7 (mean?±?SD) in non-exercising subjects within 3–6?hours and 45.8%?±?7.3 in exercising subjects within 2–3?hours. When fructose was ingested together with glucose, the mean oxidation rate of the mixed sugars increased to 66.0%?±?8.2 in exercising subjects. The mean conversion rate from fructose to glucose was 41%?±?10.5 (mean?±?SD) in 3–6?hours after ingestion. The conversion amount from fructose to glycogen remains to be further clarified. A small percentage of ingested fructose (<1%) appears to be directly converted to plasma TG. However, hyperlipidemic effects of larger amounts of fructose consumption are observed in studies using infused labeled acetate to quantify longer term de novo lipogenesis. While the mechanisms for the hyperlipidemic effect remain controversial, energy source shifting and lipid sparing may play a role in the effect, in addition to de novo lipogenesis. Finally, approximately a quarter of ingested fructose can be converted into lactate within a few of hours. The reviewed data provides a profile of how dietary fructose is utilized in humans. PMID:23031075

2012-01-01

355

Human Liver Transplantation As A Model To Study HCV Pathogenesis  

PubMed Central

Hepatitis C is a leading etiology of liver cancer and cause for liver transplantation. Although new therapies have improved the rates of sustained response, a large proportion of patients (~50%) fail to respond to antiviral treatment, thus remaining at risk for disease progression. While chimpanzees have been used to study HCV biology and treatments, their cost is quite high and their use is strictly regulated; indeed, the NIH no longer supports the breeding of chimpanzees for study. The development of HCV therapies has been hindered by the relative paucity of small animal models to study HCV pathogenesis. This review presents the strengths of the human liver transplant, highlighting the advances derived from this model, including insights into viral kinetics and quasispecies, viral receptor binding and entry, innate and adaptive immunity. Moreover, consideration is made of current and emerging antiviral therapeutic approaches based on translational research results. PMID:19877210

Hughes, Michael G.; Rosen, Hugo R.

2010-01-01

356

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

PubMed Central

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

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

357

Musculoskeletal comorbidities in cardiovascular disease, diabetes and respiratory disease: the impact on activity limitations; a representative population-based study  

Microsoft Academic Search

BACKGROUND: The purpose of this study was to quantify the contribution of comorbidity to activity limitations in populations with chronic cardiovascular disease, diabetes or respiratory disease (index conditions), with emphasis on musculoskeletal comorbidity (arthritis or back problems). METHODS: Analysis of the 2005 Canadian Community Health Survey 3.1 (age 20+ years, n = 115,915). Prevalence ratios for activity limitations in people

Morgan Slater; Anthony V Perruccio; Elizabeth M Badley

2011-01-01

358

Energy Engineering Analysis Program, limited energy study of steam distribution systems, Hawthorne Army Ammunition Depot, Hawthorne, Nevada. Energy report  

SciTech Connect

This report summarizes all work of the Limited Energy Study of Steam Distribution Systems, Energy Engineering Analysis Program, Hawthorne Army Ammunition Depot (HWAAD), Nevada. The purpose of this limited energy study is to evaluate steam distribution and condensate collection systems in both the Industrial Area and Ordnance Area of HWAAD to develop a set of replacement actions that will reduce energy consumption and operating costs. These efforts consist of corrections and revisions to previously submitted funding requests. A number of facilities covering over 140,000 acres constitute HWAAD; however, this study was limited to the Industrial and Ordnance Areas.

NONE

1995-07-01

359

Informed consent for human genetic and genomic studies: a systematic review.  

PubMed

As genetic and genomic studies grow in scale, there are ethical concerns related to the collection and use of genetic information. The emergence of large public databases potentially redefine the terms of participation in genetic and genomic research, and suggests the changing application of traditional ethical principles such as privacy or consent. For this study, we wanted to see whether such developments are reflected in the informed consent processes in human genetic and genomic studies. Therefore, we performed a systematic review of the empirical studies that examined informed consent involving large genetic databases in human genetic and genomic studies, grouped the identified issues related to the different stakeholders (including subjects, researchers, and institutional review boards) and discussed the limitations and implications of these findings. Major themes related to the place of bioethical considerations, procured tissues, people involved, process of informed consent and study procedures. Frequently raised issues included confidentiality of participants, documentation of informed consent, public attitudes, future use of participant samples or data, and disclosure of results. Awareness and attention to these bioethical issues as well as assiduousness in managing these concerns in genetic/genomic research would further strengthen and safeguard the rights, safety and well-being of genetic research participants. PMID:24646408

Khan, A; Capps, B J; Sum, M Y; Kuswanto, C N; Sim, K

2014-09-01

360

On the study of human-robot collaboration  

Microsoft Academic Search

Human-robot interaction (HRI) is being explored with the aim of creating rich, effective and satisfying interactions between humans and robots. Human-robot collaboration for learning, in which the measurable outcomes are information gain on the part of the humans in the system, is specifically focused upon. In the context of this focus on collaboration for learning, rich means a cognitively sophisticated

Illah Nourbakhsh

2006-01-01

361

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

PubMed Central

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

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

2014-01-01

362

Virus-Free Human Placental Cell Lines To Study Genetic Functions  

Cancer.gov

These immortalized virus-free human placental cell lines expressing major proteins of human trophoblasts provide efficient in vitro models to study placental functions, control of tissue-specific gene expression, and other studies.

363

76 FR 17121 - Human Studies Review Board (HSRB); Notification of a Public Meeting  

Federal Register 2010, 2011, 2012, 2013

...A published report by Gulson et al (2010) of an intentional exposure human study measuring dermal absorption of zinc oxides contained in sunscreen. d. A reevaluation of an intentional human dosing study with chlorpyrifos (Kisicki)...

2011-03-28

364

Roadmap: Criminology and Justice Studies Justice and Human Relations Bachelor of Arts  

E-print Network

Roadmap: Criminology and Justice Studies ­ Justice and Human Relations ­ Bachelor of Arts [AS: Criminology and Justice Studies ­ Justice and Human Relations ­ Bachelor of Arts [AS-BA-CRJU-JAHR] College

Sheridan, Scott

365

Comparison of methods for imputing limited-range variables: a simulation study  

PubMed Central

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

2014-01-01

366

Controls on Hyporheic Nitrate Removal: Assessing Transport and Substrate Limitations with 15N Tracer Studies (Invited)  

NASA Astrophysics Data System (ADS)

We examined transport time and substrate controls on hyporheic (HZ) nitrification and denitrification in an upland agricultural stream with a series of 15N tracer studies - whole-stream and in situ well-to-well steady-state 15NO3- and conservative tracer (Cl-) addition experiments. For the whole-stream experiment, we measured relevant solute, 15N isotope, and hydraulic transport conditions of the reach and along HZ flowpaths of an instrumented gravel bar. HZ exchange was observed across the entire gravel bar with flowpath lengths up to 4.2m and corresponding median residence times greater than 28.5h. The HZ transitioned from a net nitrification environment at its head (small residence times, <6.9h) to a net denitrification environment at its tail (large residence times, 6.9-28.5h). HZ denitrification was confirmed as 15N2 was produced across the entire gravel bar. Production of 15N2 across all observed flowpaths and residence times indicated that denitrification microsites are present even where net nitrification occurred. At large residence times, the rate of denitrification decreased despite persistent anoxic conditions, indicating substrate (NO3- and carbon) limitations. Consequently, we conducted in situ 15NO3-, conservative tracers (Cl- and Br), and acetate injection experiments to determine how the availability of labile dissolved organic carbon (DOC) as acetate influences microbial denitrification in the HZ, especially along anoxic flowpaths with large residence times. The acetate addition to the HZ stimulated significant increases in 15N2 production by factors of 2.7 to 26.1 in all receiving wells, and significant decreases of NO3- and DOC aromaticity in the wells most hydrologically connected to the injection. Further, 100% of acetate was retained in the HZ, a portion of which is due to biological consumption. These studies demonstrate that: 1. the HZ is an active nitrogen sink in this study system, 2. the distinction between net nitrification and denitrification in the HZ is a function of residence time and exhibits threshold behavior, and 3. microbial denitrification in anaerobic portions of the HZ can be limited by labile DOC supply.

Zarnetske, J. P.; Haggerty, R.; Wondzell, S. M.; Baker, M. A.

2010-12-01

367

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

PubMed Central

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

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

2013-01-01

368

Human transcriptome array for high-throughput clinical studies  

PubMed Central

A 6.9 million-feature oligonucleotide array of the human transcriptome [Glue Grant human transcriptome (GG-H array)] has been developed for high-throughput and cost-effective analyses in clinical studies. This array allows comprehensive examination of gene expression and genome-wide identification of alternative splicing as well as detection of coding SNPs and noncoding transcripts. The performance of the array was examined and compared with mRNA sequencing (RNA-Seq) results over multiple independent replicates of liver and muscle samples. Compared with RNA-Seq of 46 million uniquely mappable reads per replicate, the GG-H array is highly reproducible in estimating gene and exon abundance. Although both platforms detect similar expression changes at the gene level, the GG-H array is more sensitive at the exon level. Deeper sequencing is required to adequately cover low-abundance transcripts. The array has been implemented in a multicenter clinical program and has generated high-quality, reproducible data. Considering the clinical trial requirements of cost, sample availability, and throughput, the GG-H array has a wide range of applications. An emerging approach for large-scale clinical genomic studies is to first use RNA-Seq to the sufficient depth for the discovery of transcriptome elements relevant to the disease process followed by high-throughput and reliable screening of these elements on thousands of patient samples using custom-designed arrays. PMID:21317363

Xu, Weihong; Seok, Junhee; Mindrinos, Michael N.; Schweitzer, Anthony C.; Jiang, Hui; Wilhelmy, Julie; Clark, Tyson A.; Kapur, Karen; Xing, Yi; Faham, Malek; Storey, John D.; Moldawer, Lyle L.; Maier, Ronald V.; Tompkins, Ronald G.; Wong, Wing Hung; Davis, Ronald W.; Xiao, Wenzhong; Toner, Mehmet; Warren, H. Shaw; Schoenfeld, David A.; Rahme, Laurence; McDonald-Smith, Grace P.; Hayden, Douglas; Mason, Philip; Fagan, Shawn; Yu, Yong-Ming; Cobb, J. Perren; Remick, Daniel G.; Mannick, John A.; Lederer, James A.; Gamelli, Richard L.; Silver, Geoffrey M.; West, Michael A.; Shapiro, Michael B.; Smith, Richard; Camp, David G.; Qian, Weijun; Tibshirani, Rob; Lowry, Stephen; Calvano, Steven; Chaudry, Irshad; Cohen, Mitchell; Moore, Ernest E.; Johnson, Jeffrey; Baker, Henry V.; Efron, Philip A.; Balis, Ulysses G. J.; Billiar, Timothy R.; Ochoa, Juan B.; Sperry, Jason L.; Miller-Graziano, Carol L.; De, Asit K.; Bankey, Paul E.; Herndon, David N.; Finnerty, Celeste C.; Jeschke, Marc G.; Minei, Joseph P.; Arnoldo, Brett D.; Hunt, John L.; Horton, Jureta; Cobb, J. Perren; Brownstein, Bernard; Freeman, Bradley; Nathens, Avery B.; Cuschieri, Joseph; Gibran, Nicole; Klein, Matthew; O'Keefe, Grant

2011-01-01

369

Alkylating agent resistance: in vitro studies with human cell lines.  

PubMed Central

Development of in vitro resistance to HN2 (also called mustargen or mechlorethamine hydrochloride), N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), and cisplatin [cis-diamminedichloroplatinum(II)] was achieved in two human cell lines, the Raji/Burkitt lymphoma and a squamous cell carcinoma of the tongue. A 10- to 20-fold increase in resistance relative to the parental line was achieved in 3-4 months of continuous selection pressure. At this time, further increase in selection pressure resulted in cell death, while removal of drug led to rapid loss of resistance. However, by holding selection pressure constant over 8-12 months, semistable clones ranging in resistance up to 8- to 12-fold were obtained. The half-life for resistance loss upon removal of drug was 2-3 months. In the presence of intermittent low concentrations of the alkylating agent, resistance has been maintained in excess of 9 months. With one exception, the growth kinetics of the resistant clones were slightly slower than those of the parental lines. Cross-resistance studies were performed against HN2, BCNU, cisplatin, phenylalanine mustard, and hydroperoxycyclophosphamide. There was, in general, a lack of cross-resistance. We conclude that stable resistance to alkylating agents is produced with difficulty. We propose that these semistable cloned human tumor lines represent clinically relevant models for the study of alkylating agent resistance and that the cross-resistance patterns among these cells have important therapeutic and mechanistic implications. PMID:3856890

Frei, E; Cucchi, C A; Rosowsky, A; Tantravahi, R; Bernal, S; Ervin, T J; Ruprecht, R M; Haseltine, W A

1985-01-01

370

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.

371

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.

372

Study of the beam-beam limit in e{sup +}e{sup -} circular colliders  

SciTech Connect

Beam-beam effects limit the luminosity of circular colliders. Once the bunch population exceeds a threshold, the luminosity increases at a slower rate. This phenomenon is called the beam-beam limit. Onset of the beam-beam limit has been analyzed with various simulation methods based on the weak-strong and strong-strong models. We have observed that an incoherent phenomenon is mainly concerned in the beam-beam limit. The simulation have shown that equilibrium distributions of the two colliding beams are distorted from Gaussians when the luminosity is limited. The beam-beam limit is estimated to be (xi) {approx} 0.1 for a B factory with damping time of several thousand turns.

Ohmi, K.; Tawada, M.; Cai, Y.; Kamada, S.; Oide, K.; Qiang, J.

2004-04-02

373

[Problems and limitations of conventional and innovative methods for the diagnosis of Toxoplasmosis in humans and animals].  

PubMed

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

Piergili Fioretti, D

2004-06-01

374

SUGGESTED THREE-YEAR GRADUATION PLAN Physical Education Human Movement Studies Bachelor of Science  

E-print Network

: [14 Credit Hours] ATTR 25057 Human Anatomy and Physiology I or EXSC 25057 Human Anatomy and PhysiologySUGGESTED THREE-YEAR GRADUATION PLAN Physical Education ­ Human Movement Studies ­ Bachelor of Science [EH-BS-PEP-HMS] College of Education, Health and Human Services School of Teaching, Learning

Sheridan, Scott

375

10 http //www.kyoto-u.ac.jp/en. Integrated Human Studies  

E-print Network

Management, Urban and Environmental Engineering, Architecture and Architectural Engineering, Mechanical#12; 10 http //www.kyoto-u.ac.jp/en. Faculty of Integrated Human Studies Bachelor of Integrated Human Studies Integrated Human Studies Faculty of Letters Bachelor of Arts Letters Faculty

Takada, Shoji

376

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

E-print Network

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

Sheridan, Scott

377

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

E-print Network

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

Sheridan, Scott

378

Roadmap: Human Development and Family Studies Case Management for Individuals and Families -Bachelor of Science  

E-print Network

Roadmap: Human Development and Family Studies ­ Case Management for Individuals and Families only HDFS 44192 Internship in Human Development and Family Studies: Case Management I 3-6 Offered Internship in Human Development and Family Studies: Case Management II 3-6 Offered in spring only; fulfills

Sheridan, Scott

379

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

E-print Network

Communication Through Physical Interaction: A Study of Human Collaborative Manipulation of a Planar in human-robot interaction to develop further experiments and studies. I. INTRODUCTION Personal robot be endowed with such a capability. While physical interaction between robots and humans has been well studied

380

Human papillomavirus vaccination: a case study in translational science.  

PubMed

Each year 610,000 cases of anogenital and oropharyngeal cancers caused by human papillomavirus (HPV) occur worldwide. HPV vaccination represents a promising opportunity to prevent cancer on a global scale. The vaccine's story dates back to discoveries in chickens at the beginning of the 20th century with evidence that a cell-free filtrate could transmit the propensity to grow cancers. Later, studies with similarly derived filtrates from mammalian tumors showed that hosts could develop immunity to subsequent exposures. Epidemiologic studies linked cervical cancer to members of a family of viruses that cause papillomatosis and common warts. This led to work with DNA hybridization demonstrating a causal relationship. The formation of virus-like particles from viral capsid proteins led to the development of models for safe and effective vaccines. While much work remains with the acceptance of universal vaccination, the HPV vaccines Gardasil and Cervarix thus represent a century of successful translational research. PMID:24841923

Palmer, Allyson K; Harris, Antoneicka L; Jacobson, Robert M

2014-10-01

381

Reverse genetics system for studying human rhinovirus infections.  

PubMed

Human rhinovirus (HRV) contains a 7.2 kb messenger-sense RNA genome which is the template for reproducing progeny viruses after it enters the cytoplasm of a host cell. Reverse genetics refers to the regeneration of progeny viruses from an artificial cDNA copy of the RNA genome of an RNA virus. It has been a powerful molecular genetic tool for studying HRV and other RNA viruses because the artificial DNA stage makes it practical to introduce specific mutations into the viral RNA genome. This chapter uses HRV-16 as the model virus to illustrate the strategy and methods for constructing and cloning the artificial cDNA copy of a full-length HRV genome, identifying the infectious cDNA clone isolates, and selecting the most vigorous cDNA clone isolate to serve as the standard parental clone for future molecular genetic study of the virus. PMID:25261313

Lee, Wai-Ming; Wang, Wensheng; Bochkov, Yury A; Lee, Iris

2015-01-01

382

Using natural disasters to study prenatal maternal stress in humans.  

PubMed

Animal studies of prenatal maternal stress permit random assignment of pregnant animals to stress and no-stress groups, and allow total control of the type, severity, and timing of the stressor in utero. Human studies have obvious constraints that make the use of experimental methods nearly impossible. Studying pregnant women who experience natural disasters during pregnancy, however, approximates the random assignment to groups enjoyed by animal studies, and can characterize the timing of the stressor in utero with great precision. In this chapter, we briefly describe our three ongoing prospective longitudinal studies of children exposed to prenatal maternal stress from natural disasters. We present results from Project Ice Storm in detail, showing effects of prenatal maternal stress on cognitive and neurodevelopment. We contrast these results with preliminary findings from the Iowa Flood Study and introduce the QF2011 Queensland Flood Project. In the "Discussion" section, we present conclusions to date and discuss the relative effects of the severity of maternal objective disaster exposure and maternal subjective distress levels, the moderating effects of fetal sex and the timing of the stressor in utero, and the longevity of the effects. Finally, we discuss some possible mechanisms that may mediate the effects of prenatal maternal stress on the neurodevelopment of children. PMID:25287546

King, Suzanne; Laplante, David P

2015-01-01

383

A prospective study of floor surface, shoes, floor cleaning and slipping in US limited-service restaurant workers  

Microsoft Academic Search

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

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

384

Polarization and charge limit studies of strained GaAs photocathodes  

SciTech Connect

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.

Saez, P.J.

1997-03-01

385

Welcome to Medical Humanities Medical Humanities is an expanding area of study which aims to provide an  

E-print Network

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

Stell, John

386

Study on Factors Determining Limits of Minimum Machinable Size in Micro EDM  

Microsoft Academic Search

This paper describes an investigation on factors determining the limits of the minimum machinable diameter of micro rods obtained by micro EDM. Possible factors which influence the limits are discharge crater size, depth of heat affected zone, residual stress, and material micro-structure. In this paper, the influences of residual stress and material micro-structure were especially examined. For the negative effects

T. Kawakami; M. Kunieda

2005-01-01

387

Limits on quark-lepton compositeness and studies of W asymmetry at the Tevatron collider  

SciTech Connect

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.

Bodek, A.

1996-10-01

388

A Comparative Study of Definitions on Limit and Continuity of Functions  

ERIC Educational Resources Information Center

Differences in definitions of limit and continuity of functions as treated in courses on calculus and in rigorous undergraduate analysis yield contradictory outcomes and unexpected language. There are results about limits in calculus that are false by the definitions of analysis, functions not continuous by one definition and continuous by…

Shipman, Barbara A.

2012-01-01

389

Integrative Review of the Literature on Adults with Limited Education and Skills and the Implications for Human Resource Development  

ERIC Educational Resources Information Center

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…

Hamilton, David W.; Torraco, Richard J.

2013-01-01

390

Photoacoustic FTIR spectroscopic study of undisturbed human cortical bone  

NASA Astrophysics Data System (ADS)

Chemical pretreatment has been the prevailing sample preparation procedure for infrared (IR) spectroscopic studies on bone. However, experiments have indicated that chemical pretreatment can potentially affect the interactions between the components. Typically the IR techniques have involved transmission experiments. Here we report experimental studies using photoacoustic Fourier transform infrared spectroscopy (PA-FTIR). As a nondestructive technique, PA-FTIR can detect absorbance spectrum from a sample at controllable sampling depth and with little or no sample preparation. Additionally, the coupling inert gas, helium, which is utilized in the PA-FTIR system, can inhibit bacteria growth of bone by displacing oxygen. Therefore, we used this technique to study the undisturbed human cortical bone. It is found that photoacoustic mode (linear-scan, LS-PA-FTIR) can obtain basically similar spectra of bone as compared to the traditional transmission mode, but it seems more sensitive to amide III and ?2 carbonate bands. The ?3 phosphate band is indicative of detailed mineral structure and symmetry of native bone. The PA-FTIR depth profiling experiments on human cortical bone also indicate the influence of water on OH band and the cutting effects on amide I and mineral bands. Our results indicate that phosphate ion geometry appears less symmetric in its undisturbed state as detected by the PA-FTIR as compared to higher symmetry observed using transmission techniques on disturbed samples. Moreover, the PA-FTIR spectra indicate a band at 1747 cm-1 possibly resulting from Cdbnd O stretching of lipids, cholesterol esters, and triglycerides from the arteries. Comparison of the spectra in transverse and longitudinal cross-sections demonstrates that, the surface area of the longitudinal section bone appears to have more organic matrix exposed and with higher mineral stoichiometry.

Gu, Chunju; Katti, Dinesh R.; Katti, Kalpana S.

2013-02-01

391

Treatment-limiting toxicities associated withnucleoside analogue reverse transcriptase inhibitor therapy: A prospective, observational study**  

PubMed Central

Background: The Recover Study is an ongoing, prospective study designed 10 to assess toxicity associated with the use of nucleoside analogue reverse transcriptase inhibitors (NRTIs) (stavudine, zidovudine, lamivudine, didanosine, abacavir) in HIV-1-infected patients receiving highly active antiretroviral therapy (HAART) in routine clinical practice. This project is being conducted at 120 HIV units at teaching hospitals across Spain. Objective: The aim of this study was to identify the most common treatment-limiting 10 moderate to severe clinical and laboratory adverse effects (AEs), and the individual NRTIs involved in the development of these effects, in HIV-1-infected patients receiving HAART who discontinued use of an NRTI in the Recover Study. Methods: Patients eligible for participation in the Recover Study are aged10 ?18 years; have virologically documented HIV-1 infection; have sustained viral suppression (viral load <200 cells/mL or stable, heavily experienced [ie, have received ?3 antiretroviral regimens] patients with viral load <5000 cells/mL) for ?6 months; are receiving HAART; are undergoing active follow-up; and have developed 2:1 NRTI-associated AE that, in the opinion of a study investigator and under the conditions of routine clinical practice, justified discontinuation of treatment with the offending drug (principal AE/offending NRTI). The present study included patients recruited for the Recover Study between September 2002 and May 2003. Results: A total of 1391 patients were enrolled (966 men, 425 women; mean 1 age, 42 years [range, 18–67 years]). Five hundred six patients (36.4%) had been diagnosed with AIDS. The mean duration of treatment with the offending NRTI was 74 months (range, 6–156 months). Seven hundred nine patients (51.0%) were receiving fourth-line (or more) therapy. Eight hundred twenty-one patients (59.0%) were receiving nonnucleoside analogues, and 552 patients (39.7%), protease inhibitors, as components of their HAART regimens. The NRTIs with the highest discontinuation rates were stavudine (914 patients [65.7%]) and zidovudine (177 [12.7%]). The most frequent NRTI-related AEs were lipoatrophy (550 patients [39.5%]) and peripheral neuropathy (170 [12.2%]). Lipoatrophy was most commonly associated with stavudine (480/550 cases [87.3%]); periph eral neuropathy, with stavudine and didanosine (107/170 [62.9%] and 48/170 [28.2%] cases, respectively); and anemia, with zidovudine (70/77 cases [90.9%]). Conclusions: The results of this study in patients with HIV-1 recruited in the10 Recover Study and undergoing HAART suggest that long-term treatment with NRTIs is associated with AEs (lipoatrophy, peripheral neuropathy, and lipodystrophy), with morphologic disorders (lipoatrophy, lipodystrophy) being the most common AEs leading to discontinuation. Minimizing these AEs by switching to an NRTI not associated with these AEs (eg, tenofovir) would contribute to adherence and hence efficacy of long-term HAART. PMID:24672118

Palacios, Rosario; Santos, Jesús; Camino, Xavier; Arazo, Piedad; Torres Perea, Rafael; Echevarrfa, Santiago; Ribera, Esteban; Sánchez de la Rosa, Rainel; Moreno Guillen, Santiago

2005-01-01

392

A study of localization limiters and mesh dependency in earthquake rupture.  

PubMed

No complete physically consistent model of earthquake rupture exists that can fully describe the rich hierarchy of scale dependencies and nonlinearities associated with earthquakes. We study mesh sensitivity in numerical models of earthquake rupture and demonstrate that this mesh sensitivity may provide hidden clues to the underlying physics generating the rich dynamics associated with earthquake rupture. We focus on unstable slip events that occur in earthquakes when rupture is associated with frictional weakening of the fault. Attempts to simulate these phenomena directly by introducing the relevant constitutive behaviour leads to mesh-dependent results, where the deformation localizes in one element, irrespective of size. Interestingly, earthquake models with oversized mesh elements that are ill-posed in the continuum limit display more complex and realistic physics. Until now, the mesh-dependency problem has been regarded as a red herring-but have we overlooked an important clue arising from the mesh sensitivity? We analyse spatial discretization errors introduced into models with oversized meshes to show how the governing equations may change because of these error terms and give rise to more interesting physics. PMID:19948546

Olsen-Kettle, Louise; Mühlhaus, Hans; Baillard, Christian

2010-01-13

393

Studying the inspection limits in detecting buried objects by using infrared thermography  

NASA Astrophysics Data System (ADS)

In Japan it happens that building parts made of concrete suddenly collapse to create obstacles to the traffic in tunnels, on highways and bridges. Thus, the safety issue has become a serious social problem. Therefore, the detection of hidden defects in concrete building constructions in order to prevent an accidental damage is the important application area for nondestructive testing (NDT) techniques. Until now, the inspection is typically performed by using a hammer that is subjective and takes too much time. Infrared thermography is a promising NDT technique that might help in the fast detection of invisible (hidden) defects. Transient, or active, thermal NDT requires external thermal stimulation of the defects under test by warming up or cooling down the defect surface. However, low-power and long heating is significantly affected by environmental conditions. Recent Japanese research in this area has been rather qualitative, i.e. without putting the accent on evaluating parameters of hidden defects. In this study, the experimental results are modeled and processed by using the thermal NDT package developed at the Tomsk Institute of Introscopy. This has allowed not only optimizing test parameters but also obtaining reasonable estimates of defect parameters for air-filled voids and inclusions in concrete. It is shown that MRTD values experimented by us are of a little help while evaluating detection limits.

Kamoi, Arao; Okamoto, Yoshizo; Vavilov, Vladimir P.

2003-04-01

394

Use of human lung tissue for studies of structural changes associated with chronic ozone exposure: Opportunities and critical issues  

SciTech Connect

Definitive information on the chronic effects of exposure to ozone (O{sub 3}) in humans is not available. There is a strong concern that ozone could produce chronic lung damage in humans on the basis that exposures are ubiquitous at levels that produce transient symptoms, function deficits, and lung inflammation in humans and chronic lung damage in laboratory animals. Both prospective and national population surveys suggest an association between chronic O{sub 3} exposure and reduced lung function, and a pilot investigation of autopsied lungs of accident victims in Los Angeles reported an unexpectedly high incidence of disease in the centriacinar region, the lung region known to receive the highest dose of inhaled O{sub 3}. This paper discusses the advantages and limitations of further studies of structural changes in human lung tissue in relation to chronic O{sub 3} exposure. The major advantages of such studies are that (a) measurable effects may be related to realistic chronic exposures, (b) the effects may be described quantitatively and compared directly to those obtained in chronic animal inhalation exposures, and (c) evidence for chronic effects may be obtained much more rapidly than in prospective studies. The major limitations are the difficulties in obtaining sufficient reliable information on residential history, physical activity out-of-doors, and smoking and other confounding exposures to lung irritants from next of kin, and limited availability of adequate air quality data for determining ambient concentrations at places of residence and/or outdoor exercise. The paper also discusses approaches to minimizing these limitations in the design of specific studies. 15 refs.

Lippmann, M. [New York Univ. Medical Center, Tuxedo, NY (United States)

1993-12-01

395

Glycoconjugates of the human trabecular meshwork: a lectin histochemical study.  

PubMed

Twelve specimens of resin-embedded human trabecular meshwork were probed with a panel of 21 biotinylated lectins, using an avidin-biotin peroxidase revealing system, in order to determine the normal pattern of saccharide expression in this tissue. High-mannose, intermediate and hybrid N-linked glycans, and complex N-linked bisected and non-bisected bi/tri-antennate glycans, as shown by the binding of Canavalia ensiformis (ConA), Pisum sativum (PSA), Lens culinaris (LCA) agglutinins and Phaseolus vulgaris erythroagglutinin (ePHA), were strongly expressed by the canal of Schlemm endothelium and juxtacanalicular tissue, but less so by the corneoscleal meshwork. Highly branced complex glycans were not found, as there was no binding by Phaseolus vulgaris leukoagglutinin (IPHA). Sialyl residues, especially those alpha 2,6-linked as demonstrated by strong Sambucus nigra (SNA) lectin staining, were also abundant in this area. N-acetyllactosamine sequences and some O-linked glycans were present in the trabecular meshwork, as shown by Solanum tuberosum (STA), Datura stramonium (DSA), and Jacalin (Jac) lectin binding, while fucose residues were not detected by Tetragonolobus purpureas (LTA) or Ulex europaeus-1 (UEA-1) agglutinins. These results indicate similarities with renal glomerular and vascular endothelium, although the lack of binding with UEA-1 agglutinin suggests differences which may relate to the specialized function of the trabecular meshwork. This study provides a baseline for comparative analysis of the glycans of human trabecular meshwork in pathological conditions such as primary open-angle glaucoma. PMID:8787965

Chapman, S A; Bonshek, R E; Stoddart, R W; Jones, C J; Mackenzie, K R; O'Donoghue, E; Mcleod, D

1995-11-01

396

Resveratrol and diabetes: from animal to human studies.  

PubMed

Diabetes mellitus is a serious disease affecting about 5% of people worldwide. Diabetes is characterized by hyperglycemia and impairment in insulin secretion and/or action. Moreover, diabetes is associated with metabolic abnormalities and serious complications. Resveratrol is a natural, biologically active polyphenol present in different plant species and known to have numerous health-promoting effects in both animals and humans. Anti-diabetic action of resveratrol has been extensively studied in animal models and in diabetic humans. In animals with experimental diabetes, resveratrol has been demonstrated to induce beneficial effects that ameliorate diabetes. Resveratrol, among others, improves glucose homeostasis, decreases insulin resistance, protects pancreatic ?-cells, improves insulin secretion and ameliorates metabolic disorders. Effects induced by resveratrol are strongly related to the capability of this compound to increase expression/activity of AMPK and SIRT1 in various tissues of diabetic subjects. Moreover, anti-oxidant and anti-inflammatory effects of resveratrol were shown to be also involved in its action in diabetic animals. Preliminary clinical trials show that resveratrol is also effective in type 2 diabetic patients. Resveratrol may, among others, improve glycemic control and decrease insulin resistance. These results show that resveratrol holds great potential to treat diabetes and would be useful to support conventional therapy. This article is part of a Special Issue entitled: Resveratol: Challenges in translating pre-clincial findigns to iproved patient outcomes, guest edited by J. Dyck and P. Schrauwen. PMID:25445538

Szkudelski, Tomasz; Szkudelska, Katarzyna

2014-10-27

397

A study in human attention to guide computational action recognition  

E-print Network

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 ...

Sinai, Sam

2014-01-01

398

Insights into the evolution of human bipedalism from experimental studies of humans and other primates  

Microsoft Academic Search

An understanding of the evolution of human bipedalism can provide valuable insights into the biomechanical and physiological characteristics of locomotion in modern humans. The walking gaits of humans, other bipeds and most quadrupedal mammals can best be described by using an inverted-pendulum model, in which there is minimal change in flexion of the limb joints during stance phase. As a

Daniel Schmitt

2003-01-01

399

Human neuroimaging studies on the hippocampal CA3 region – integrating evidence for pattern separation and completion  

PubMed Central

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

Deuker, Lorena; Doeller, Christian F.; Fell, Juergen; Axmacher, Nikolai

2014-01-01

400

Evaluation of dengue virus strains for human challenge studies.  

PubMed

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-naďve 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-naďve 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

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

401

Study of Mitral Valve in Human Cadaveric Hearts  

PubMed Central

Objectives: The mitral valve is a complex structure that is altered by disease states. The classical image of the mitral valve is a bicuspid valve with two leaflets and two papillary muscles. The reason for the present study is to study the morphology and morphometry of the mitral valve. Materials and Methods: This study was carried out on 116 human cadaveric hearts. Hearts were opened along the left border through the atrioventricular valve. The diameter and circumference of the annulus was measured and the number of valve leaflets was observed. Results: The mean annular diameter was 2.22 cm. The mean circumference of mitral valve annulus was 9.12 cm. The standard description of the mitral valve is bicuspid. In the present study, we found the number of cusps to be variable, from monocuspid to hexacuspid and classified them accordingly. Conclusions: The mitral valve is not always a bicuspid valve. The number of cusps varies greatly. An increase in the number of the cusp and their improper approximation most likely causes various valvular disorders. PMID:23439693

Gunnal, S. A.; Farooqui, M. S.; Wabale, R. N.

2012-01-01

402

Induction and autoinduction properties of rifamycin derivatives: a review of animal and human studies.  

PubMed Central

Animal studies have demonstrated that the mouse and rabbit are far more responsive to the inductive properties of rifamycin derivatives than the rat and guinea pig. The rat hepatic cytochrome P450 system seems to be resistant to the action of rifampicin unless very high doses are used. Mouse hepatic microsomal mixed-function oxidase activity is markedly increased by repeated dosing with rifampicin, whereas administration of rifabutin may be ineffective. In humans, both rifampicin and rifabutin are extensively metabolized and induce their own metabolism. The induced metabolic pathways remain essentially unknown. Under autoinduction conditions, the elimination half-life of rifampicin decreases, whereas that of rifabutin is not altered. Although the effects of repeated administration of rifampicin and rifabutin on the various forms of cytochrome P450 in humans have not been extensively examined, there is convincing evidence that the P4503A subfamily is induced by either drug, whereas the P4501A subfamily and P4502D6 do not appear to be affected by rifampicin. Limited reliable information is available concerning the induction of human glucuronyltransferase activities by rifampicin and rifabutin which, however, do not seem to influence zidovudine glucuronide formation in healthy subjects. PMID:7698069

Strolin Benedetti, M; Dostert, P

1994-01-01

403

Life Sciences Division and Center for Human Genome Studies  

SciTech Connect

This report summarizes the research and development activities of Los Alamos National Laboratory's Life Sciences Division and biological aspects of the Center for Human Genome Studies for the calendar year 1990. The technical portion of the report is divided into two parts: (1) selected research highlights, and (2) project descriptions and accomplishments. Research highlights provide a more detailed description of a select set of projects. A technical description of all projects is presented in sufficient detail to permit the informed reader to assess their scope and significance. Summaries useful to the casual reader desiring general information have been prepared by the group leaders and appear in each group overview. Investigators on the staff of the Life Sciences Division will be pleased to provide further information.

Spitzmiller, D.; Bradbury, M.; Cram, S. (comps.)

1991-07-01

404

Model systems for the study of human norovirus Biology  

PubMed Central

The relative contribution of norovirus to disease burden on society has only recently been established and they are now established as a major cause of gastroenteritis in the developed world. However, despite the medical relevance of these viruses, an efficient in vitro cell culture system for human noroviruses has yet to be developed. As a result, much of our knowledge on the basic mechanisms of norovirus biology has come from studies using other members of the Caliciviridae family of small positive stranded RNA viruses. Here we aim to summarise the recent advances in the field, highlighting how model systems have played a key role in increasing our knowledge of this prevalent pathogen. PMID:21516251

Vashist, S; Bailey, D; Putics, A; Goodfellow, I

2011-01-01

405

The limits of technological optimism  

Microsoft Academic Search

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

Andrew D. Basiago

1994-01-01

406

Studying semblances of a true killer: experimental model of human ventricular fibrillation.  

PubMed

It is unknown whether ventricular fibrillation (VF) studied in experimental models represents in vivo human VF. First, we examined closed chest in vivo VF induced at defibrillation threshold testing (DFT) in four patients with ischemic cardiomyopathy pretransplantation. We examined VF in these same four hearts in an ex vivo human Langendorff posttransplantation. VF from DFT was compared with VF from the electrodes from a similar region in the right ventricular endocardium in the Langendorff using two parameters: the scale distribution width (extracted from continuous wavelet transform) and VF mean cycle length (CL). In a second substudy group where multielectrode phase mapping could be performed, we examined early VF intraoperatively (in vivo open chest condition) in three patients with left ventricular cardiomyopathy. We investigated early VF in the hearts of three patients in an ex vivo Langendorff and compared findings with intraoperative VF using two metrics: dominant frequency (DF) assessed by the Welch periodogram and the number of phase singularities (lasting >480 ms). Wavelet analysis (P = 0.9) and VF CL were similar between the Langendorff and the DFT groups (225 ± 13, 218 ± 24 ms; P = 0.9), indicating that wave characteristics and activation rate of VF was comparable between the two models. Intraoperative DF was slower but comparable with the Langendorff DF over the endocardium (4.6 ± 0.1, 5.0 ± 0.4 Hz; P = 0.9) and the epicardium (4.5 ± 0.2, 5.2 ± 0.4 Hz; P = 0.9). Endocardial phase singularity number (9.6 ± 5, 12.1 ± 1; P = 0.6) was lesser in number but comparable between in vivo and ex vivo VF. VF dynamics in the limited experimental human studies approximates human in vivo VF. PMID:22268105

Nair, K; Farid, T; Masse, S; Umapathy, K; Watkins, S; Poku, K; Asta, J; Kusha, M; Sevaptsidis, E; Jacob, J; Floras, J S; Nanthakumar, K

2012-04-01

407

Studying semblances of a true killer: experimental model of human ventricular fibrillation  

PubMed Central

It is unknown whether ventricular fibrillation (VF) studied in experimental models represents in vivo human VF. First, we examined closed chest in vivo VF induced at defibrillation threshold testing (DFT) in four patients with ischemic cardiomyopathy pretransplantation. We examined VF in these same four hearts in an ex vivo human Langendorff posttransplantation. VF from DFT was compared with VF from the electrodes from a similar region in the right ventricular endocardium in the Langendorff using two parameters: the scale distribution width (extracted from continuous wavelet transform) and VF mean cycle length (CL). In a second substudy group where multielectrode phase mapping could be performed, we examined early VF intraoperatively (in vivo open chest condition) in three patients with left ventricular cardiomyopathy. We investigated early VF in the hearts of three patients in an ex vivo Langendorff and compared findings with intraoperative VF using two metrics: dominant frequency (DF) assessed by the Welch periodogram and the number of phase singularities (lasting >480 ms). Wavelet analysis (P = 0.9) and VF CL were similar between the Langendorff and the DFT groups (225 ± 13, 218 ± 24 ms; P = 0.9), indicating that wave characteristics and activation rate of VF was comparable between the two models. Intraoperative DF was slower but comparable with the Langendorff DF over the endocardium (4.6 ± 0.1, 5.0 ± 0.4 Hz; P = 0.9) and the epicardium (4.5 ± 0.2, 5.2 ± 0.4 Hz; P = 0.9). Endocardial phase singularity number (9.6 ± 5, 12.1 ± 1; P = 0.6) was lesser in number but comparable between in vivo and ex vivo VF. VF dynamics in the limited experimental human studies approximates human in vivo VF. PMID:22268105

Nair, K.; Farid, T.; Masse, S.; Umapathy, K.; Watkins, S.; Poku, K.; Asta, J.; Kusha, M.; Sevaptsidis, E.; Jacob, J.; Floras, J. S.

2012-01-01

408

Preclinical safety studies on autologous cultured human skin fibroblast transplantation.  

PubMed

Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts. PMID:23211390

Zeng, Wei; Zhang, Shuying; Liu, Dai; Chai, Mi; Wang, Jiaqi; Zhao, Yuming

2014-01-01

409

International study of factors affecting human chromosome translocations  

PubMed Central

Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of gender, race, and cigarette smoking on background translocation yields have not been examined systematically. Further, the shape of the relationship between age and translocation frequency (TF) has not been definitively determined. We collected existing data from sixteen laboratories in North America, Europe, and Asia on TFs measured in peripheral blood lymphocytes by fluorescence in situ hybridization whole chromosome painting among 1933 individuals. In Poisson regression models, age, ranging from newborns (cord blood) to 85 years, was strongly associated with TF and this relationship showed significant upward curvature at older ages vs. a linear relationship (p <0.001). Ever smokers had significantly higher TFs than non-smokers (rate ratio (RR) = 1.19, 95% confidence interval (CI), 1.09–1.30) and smoking modified the effect of age on TFs with a steeper age-related increase among ever smokers compared to non-smokers (p<0.001). TFs did not differ by gender. Interpreting an independent effect of race was difficult owing to laboratory variation. Our study is three times larger than any pooled effort to date, confirming a suspected curvilinear relationship of TF with age. The significant effect of cigarette smoking has not been observed with previous pooled studies of TF in humans. Our data provide stable estimates of background TF by age, gender, race, and smoking status and suggest an acceleration of chromosome damage above age 60 and among those with a history of smoking cigarettes. PMID:18337160

Sigurdson, Alice J.; Ha, Mina; Hauptmann, Michael; Bhatti, Parveen; Sram, Radim J.; Beskid, Olena; Tawn, E. Janet; Whitehouse, Caroline A.; Lindholm, Carita; Nakano, Mimako; Kodama, Yoshiaki; Nakamura, Nori; Vorobtsova, Irena; Oestreicher, Ursula; Stephan, Günther; Yong, Lee C.; Bauchinger, Manfred; Schmid, Ernst; Chung, Hai Won; Darroudi, Firouz; Roy, Laurence; Voisin, Phillipe; Barquinero, Joan F.; Livingston, Gordon; Blakey, David; Hayata, Isamu; Zhang, Wei; Wang, Chunyan; Bennett, L. Michelle; Littlefield, L. Gayle; Edwards, Alan A.; Kleinerman, Ruth A.; Tucker, James D.

2009-01-01

410

Citation Analysis for Collection Development: A Comparative Study of Eight Humanities Fields  

ERIC Educational Resources Information Center

This study analyzes 9,131 citations from the 2002 volumes of journals in eight humanities fields: art, classics, history, linguistics, literature, music, philosophy, and religion. This study found that citation patterns varied widely among humanities disciplines. Due to these differences, it is important for librarians with humanities collection…

Knievel, Jennifer E.; Kellsey, Charlene

2005-01-01

411

[A morphological study of human hair tips by scanning electronic microscope (SEM)].  

PubMed

Morphological characteristics of human hair tip was studied by SEM. It was concluded that human hair tips could be classified into eight types. The tip formation, distribution and changes after being trimmed were explored. This study can be used in the mechanism research of human hair growth and the forensic hair examination. PMID:11938877

Ding, M

1998-01-01

412

Development and validation of a highly sensitive LC-MS/MS method for quantitation of dexlansoprazole in human plasma: application to a human pharmacokinetic study.  

PubMed

A highly sensitive, specific and simple LC-MS/MS method was developed for the simultaneous estimation of dexlansoprazole (DEX) with 50 ?L of human plasma using omeprazole as an internal standard (IS). The API-4000 LC-MS/MS was operated under multiple reaction-monitoring mode using electrospray ionization. A simple liquid-liquid extraction process was used to extract DEX and IS from human plasma. The total run time was 2.00 min and the elution of DEX and IS occurred at 1.20 min. This was achieved with a mobile phase consisting of 0.2% ammonia-acetonitrile (20:80, v/v) at a flow rate of 0.50 mL/min on an X-terra RP 18 (50 × 4.6 mm, 5 µm) column. The developed method was validated in human plasma with a lower limit of quantitation of 2 ng/mL for DEX. A linear response function was established for the range of concentrations 2.00-2500.0 ng/mL (r > 0.998) for DEX. The intra- and inter-day precision values for DEX met the acceptance criteria as per FDA guidelines. DEX was stable in the battery of stability studies, viz. bench-top, auto-sampler and freeze-thaw cycles. The developed assay method was applied to an oral bioequivalence study in humans. PMID:21618562

Hotha, Kishore Kumar; Vijaya Bharathi, D; Jagadeesh, B; Ravindranath, L K; Jaya Veera, K N; Venkateswarulu, V

2012-02-01

413

Experimental study of a transformer with superconducting elements for fault current limitation and energy redistribution  

NASA Astrophysics Data System (ADS)

Numerous proposed and developed superconducting fault current limiters and self-limiting transformers limit successfully fault currents but do not provide uninterrupted supplying of consumers. A design investigated in the work combines the functions of a conventional transformer with the functions of fast energy redistribution and fault protection. The device constitutes a transformer containing an additional high-temperature superconducting (HTS) coil short-circuited by a thin film HTS switching element. Fault current limitation and redistribution of the power flow to a standby line are achieved as a result of a fast transition of the superconducting switching element from the superconducting into the normal state. Transient and steady-state characteristics were experimentally investigated. A mathematical model of the device operation was proposed, and the calculated results were found to be in good agreement with the experimental data. The application field and basic requirements to such devices were discussed and it was shown that the proposed device meets these requirements.

Meerovich, V.; Sokolovsky, V.

2005-08-01

414

Illness perceptions and activity limitations in osteoarthritis of the knee: a case report intervention study.  

PubMed

This case report describes the process and outcome of an intervention where illness perceptions (IPs) were targeted in order to reduce limitations in daily activities. The patient was a 45-year-old woman diagnosed with posttraumatic secondary osteoarthritis of the lateral patella-femoral cartilage of the right knee. At baseline, the patient reported maladaptive IPs on the Brief Illness Perception Questionnaire Dutch Language Version and limitations in walking stairs, cycling and walking. Fewer limitations in daily activities are hypothesized by changing maladaptive IPs into more favourable IPs. In this case report, discussing maladaptive IPs with the patient was the main intervention. A participatory decision making model was used as a design by which the maladaptive IP were discussed. Six out of eight maladaptive IPs changed favourably and there was a clinically relevant decrease in limitations of daily activities. The Global Perceived Effect was rated as much improved. PMID:24011782

de Raaij, Edwin J; Pool, Jan; Maissan, François; Wittink, Harriët

2014-04-01

415

A statistical study of the geological limits to Advanced Piston Coring: ODP Legs 101-149  

E-print Network

The Advanced Piston Corer (APC), a soft sediment coring system developed from the hydraulic piston corer (HPC), allows recovery of ocean sediments with minimal coring disturbance. As a coring too[, the APC system is subject to limitations imposed...

Lee, Yir-Der Eddy

1995-01-01

416

Seedling establishment in an epiphytic orchid: an experimental study of seed limitation  

Microsoft Academic Search

Will increased fruit and seed production in a severely pollination-limited orchid stimulate population growth? We tested whether safe sites for germination and seedling establishment are limiting for the twig epiphyte, Tolumnia variegata, by manipulating fruit set and monitoring subsequent seedling establishment for two seasons (1991–1992, 1992–1993). In the Cambalache Forest Reserve of Puerto Rico, we established 36 plots along a

J. D. Ackerman; A. Sabat; J. K. Zimmerman

1996-01-01

417

A comparative study of limited-angle cone-beam reconstruction methods for breast tomosynthesis  

Microsoft Academic Search

Digital tomosynthesis mammography (DTM) is a promising new modality for breast cancer detection. In DTM, projection-view images are acquired at a limited number of angles over a limited angular range and the imaged volume is reconstructed from the two-dimensional projections, thus providing three-dimensional structural information of the breast tissue. In this work, we investigated three representative reconstruction methods for this

Yiheng Zhang; Heang-Ping Chan; Berkman Sahiner; Jun Wei; Mitchell M. Goodsitt; Lubomir M. Hadjiiski; Jun Ge; Chuan Zhou

2006-01-01

418

A comparative study of recombinant mouse and human apurinic/apyrimidinic endonuclease.  

PubMed

Mammalian apurinic/apyrimidinic endonuclease (APE1) initiates the repair of abasic sites (AP-sites), which are highly toxic, mutagenic, and implicated in carcinogenesis. Also, reducing the activity of APE1 protein in cancer cells and tumors sensitizes mammalian tumor cells to a variety of laboratory and clinical chemotherapeutic agents. In general, mouse models are used in studies of basic mechanisms of carcinogenesis, as well as pre-clinical studies before transitioning into humans. Human APE1 (hAPE1) has previously been cloned, expressed, and extensively characterized. However, the knowledge regarding the characterization of mouse APE1 (mAPE1) is very limited. Here we have expressed and purified full-length hAPE1 and mAPE1 in and from E. coli to near homogeneity. mAPE1 showed comparable fast reaction kinetics to its human counterpart. Steady-state enzyme kinetics showed an apparent K(m) of 91 nM and k(cat) of 4.2 s(-1) of mAPE1 for the THF cleavage reaction. For hAPE1 apparent K(m) and k(cat) were 82 nM and 3.2 s(-1), respectively, under similar reaction conditions. However, k(cat)/K(m) were in similar range for both APE1s. The optimum pH was in the range of 7.5-8 for both APE1s and had an optimal activity at 50-100 mM KCl, and they showed Mg(2+) dependence and abrogation of activity at high salt. Circular dichroism spectroscopy revealed that increasing the Mg(2+) concentration altered the ratio of "turns" to "?-strands" for both proteins, and this change may be associated with the conformational changes required to achieve an active state. Overall, compared to hAPE1, mAPE1 has higher K(m) and k(cat) values. However, overall results from this study suggest that human and mouse APE1s have mostly similar biochemical and biophysical properties. Thus, the conclusions of mouse studies to elucidate APE1 biology and its role in carcinogenesis may be extrapolated to apply to human biology. This includes the development and validation of effective APE1 inhibitors as chemosensitizers in clinical studies. PMID:22042551

Adhikari, Sanjay; Manthena, Praveen Varma; Kota, Krishna Kiran; Karmahapatra, Soumendra Krishna; Roy, Gargi; Saxena, Rahul; Uren, Aykut; Roy, Rabindra

2012-03-01

419

Theranostic Studies of Human Sodium Iodide Symporter Imaging and Therapy Using 188Re: A Human Glioma Study in Mice  

PubMed Central

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

Guo, Rui; Zhang, M.; Xi, Yun; Ma, Yufei; Liang, Sheng; Shi, Shuo; Miao, Ying; Li, Biao

2014-01-01

420

Binding of amifostine to human serum albumin: A biophysical study.  

PubMed

The aim of this present work is to investigate the interaction between amifostine and human serum albumin (HSA) in simulated physiological conditions by spectroscopic methods to reveal potential toxic effects of the drug. The results reflected that amifostine caused fluorescence quenching of HSA through a static quenching process, which was further confirmed by the electrochemical experiments. The binding constants at 290, 297 and 304?K were obtained as 2.53?×?10(5) /M, 8.13?×?10(4) /M and 3.59?×?10(4) /M, respectively. There may be one binding site of amifostine on HSA. The thermodynamic parameters indicated that the interaction between amifostine and HSA was driven mainly by hydrogen bonding and electrostatic forces. Synchronous fluorescence spectra, circular dichroism and Fourier transform infrared spectroscopy results showed amifostine binding slightly changed the conformation of HSA with secondary structural content changes. Förster resonance energy transfer study revealed high possibility of energy transfer with amifostine-Trp-214 distance of 3.48?nm. The results of the present study may provide valuable information for studying the distribution, toxicological and pharmacological mechanisms of amifostine in vivo. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24962599

Sun, Yifu; Wu, Han; Zhao, Guoqing; Shi, Ying

2015-02-01

421

Methods for studying drug effects on superficial human veins.  

PubMed

Direct effects of vasoactive substances on superficial human veins in vivo can be investigated by measuring changes in the diameter of a superficial vein at a standardized congestion pressure which reflect changes in venous tone before and after local infusion of the drugs. The diameter of a superficial hand vein is measured with the aid of a linear variable differential transformer mounted directly on the back of the hand. The central core of the transformer positioned over the summit of the vein moves simultaneously with changes in venous diameter and allows continuous recording of these alterations. A series of ergot alkaloids were investigated with this technique and found to elicit a direct constrictor action when infused locally. Studies on the mode of action of the venoconstrictor effects of ergot alkaloids suggest that they are mediated by stimulation of alpha- and 5-HT-receptors. Similarly, guanfacine, a centrally-acting antihypertensive drug, reduces venous compliance after direct local administration as a result of alpha-adrenoceptor stimulation. The venodilator effect of isoprenaline can be shown in veins preconstricted with noradrenaline, whereas with nitroglycerine, venodilatation is observed by local infusions in veins not preconstricted. This method is therefore useful for studying the direct effects of venoconstrictor and venodilator drugs in man. The technique can also be used to study interactions between different agents and thus to investigate the mode of action of drugs. Drugs can be infused locally at doses which do not elicit systemic effects. PMID:3840550

Aellig, W H

1985-06-01

422

Netupitant PET imaging and ADME studies in humans  

PubMed Central

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

Spinelli, Tulla; Calcagnile, Selma; Giuliano, Claudio; Rossi, Giorgia; Lanzarotti, Corinna; Mair, Stuart; Stevens, Lloyd; Nisbet, Ian

2014-01-01

423

Studies of alpha-granule proteins in cultured human megakaryocytes.  

PubMed

alpha-Granule protein storage is important for producing platelets with normal haemostatic function. The low to undetectable levels of several megakaryocyte-synthesized alpha-granule proteins in normal plasma suggest megakaryocytes are important to sequester these proteins in vivo. alpha-Granule protein storage in vitro has been studied using other cell types, with differences observed in how some proteins are processed compared to platelets. Human megakaryocytes, cultured from cord blood CD34(+) cells and grown in serum-free media containing thrombopoietin, were investigated to determine if they could be used as a model for studying normal alpha-granule protein processing and storage. ELISA indicated that cultured megakaryocytes contained the alpha-granule proteins multimerin, von Willebrand factor, thrombospondin-1, beta-thromboglobulin and platelet factor 4, but no detectable fibrinogen and factor V. A significant proportion of the alpha-granule protein in megakaryocyte cultures was contained within the cells (averages: 41-71 %), consistent with storage. Detailed analyses of multimerin and von Willebrand factor confirmed that alpha-granule proteins were processed to mature forms and were predominantly located in the alpha-granules of cultured megakaryocytes.Thrombopoietin-stimulated cultured megakaryocytes provide a useful model for studying alpha-granule protein processing and storage. PMID:14597980

Veljkovic, Dragoslava Kika; Cramer, Elisabeth M; Alimardani, Gulie; Fichelson, Serge; Massé, Jean-Marc; Hayward, Catherine P M

2003-11-01

424

Limited utility despite accuracy of the national SEER dataset for the study of craniopharyngioma.  

PubMed

Craniopharyngioma is histologically benign and associated with high survival rates but poor quality of life. The SEER Program is among the most cited data sources regarding malignancies in the United States. SEER began collecting data regarding craniopharyngiomain 2004. SEER-STAT v7.0.5 was utilized to identify patients (January 1, 2004-December 31, 2008) with ICD-O-3 codes for craniopharyngioma. Age was categorized into 3 groups: ?19, 20-34, and ?35 years, as was surgical intervention: none, subtotal resection, and gross total/radical resection. Demographic, initial treatment, and follow-up data were collected. 635/662 (95.9 %) patients had complete data. Incidence per million patient-years by age group was 1.9, 1.1, and 1.9, respectively (p < 0.0001). There was bimodal incidence, with peaks at 5-9 and 60-74 years. Surgery occurred in 528 patients (83.1 %), without association between age group and extent of surgery (p = 0.14). Radiation was delivered in 139 (21.9 %) cases, with no association between treatment and extent of surgery (p = 0.73) or age group (p = 0.14). Median follow-up was 23 months. Overall and Cause-specific Survival were 87.9 and 94.5 %, respectively. Neither was associated with extent of surgery but both were positively associated with radiation (p = 0.0003 and 0.0007, respectively). There was no difference in OS or CSS when comparing STR ± RT versus GTR alone (p = 0.38 and 0.56, respectively). SEER provides reliable demographic and survival data regarding craniopharyngioma. SEER's focus on mortality statistics limits utility for outcomes studies in tumors with high survival rates, such as craniopharyngioma. Initial treatment data from SEER varies somewhat from current literature, meriting further investigation. PMID:22915191

Hankinson, Todd C; Fields, Emma C; Torok, Michelle R; Beaty, Brenda L; Handler, Michael H; Foreman, Nicholas K; O'neill, Brent R; Liu, Arthur K

2012-11-01

425

The Trans/National Study of Culture and The Institutions of Human Speciation  

E-print Network

Speciation Jon SOLOMON Université Jean Moulin, Lyon 3 "The Trans/National Study of Culture and the Institutions of Human Speciation."2011. Outis. Milan: Mimesis edizioni. 87-104. The Institutions of Human Speciation The teleology of post

Boyer, Edmond

426

Limitations on the use of ion implantation for the study of the reactive element effect in [beta]NiAl  

Microsoft Academic Search

Numerous investigations have used the ion implantation of reactive elements (RE) such as Y or Ce, to study their effect on the growth of external oxide scales on alloys. Ion implantation has, nevertheless, some specific limitations, especially in Al[sub 2]O[sub 3]-forming alloys. The most notable limitation occurs at temperatures > 1,000 C where, owing to the shallowness of implantation, any

B. A. Pint; L. W. Hobbs

1994-01-01

427

A numerical study of the small dispersion limit of the Korteweg-de Vries equation and asymptotic solutions  

NASA Astrophysics Data System (ADS)

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.

Grava, T.; Klein, C.

2012-12-01

428

Modeling aspects of human memory for scientific study.  

SciTech Connect

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.

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.