Understanding Organizational Culture.

ERIC Educational Resources Information Center

Burkhart, Jennifer

This guide, which is intended for workplace education providers, defines organizational culture, reviews selected techniques for reading a company's culture, and presents examples of ways in which organizations' culture can affect workplace education programs. An organization's culture is determined by: recognizing the company's philosophy…

Balancing selection on immunity genes: review of the current literature and new analysis in Drosophila melanogaster.

PubMed

Croze, Myriam; Živković, Daniel; Stephan, Wolfgang; Hutter, Stephan

2016-08-01

Balancing selection has been widely assumed to be an important evolutionary force, yet even today little is known about its abundance and its impact on the patterns of genetic diversity. Several studies have shown examples of balancing selection in humans, plants or parasites, and many genes under balancing selection are involved in immunity. It has been proposed that host-parasite coevolution is one of the main forces driving immune genes to evolve under balancing selection. In this paper, we review the literature on balancing selection on immunity genes in several organisms, including Drosophila. Furthermore, we performed a genome scan for balancing selection in an African population of Drosophila melanogaster using coalescent simulations of a demographic model with and without selection. We find very few genes under balancing selection and only one novel candidate gene related to immunity. Finally, we discuss the possible causes of the low number of genes under balancing selection. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Life imitating art: depictions of the hidden curriculum in medical television programs.

PubMed

Stanek, Agatha; Clarkin, Chantalle; Bould, M Dylan; Writer, Hilary; Doja, Asif

2015-09-26

The hidden curriculum represents influences occurring within the culture of medicine that indirectly alter medical professionals' interactions, beliefs and clinical practices throughout their training. One approach to increase medical student awareness of the hidden curriculum is to provide them with readily available examples of how it is enacted in medicine; as such the purpose of this study was to examine depictions of the hidden curriculum in popular medical television programs. One full season of ER, Grey's Anatomy and Scrubs were selected for review. A summative content analysis was performed to ascertain the presence of depictions of the hidden curriculum, as well as to record the type, frequency and quality of examples. A second reviewer also viewed a random selection of episodes from each series to establish coding reliability. The most prevalent themes across all television programs were: the hierarchical nature of medicine; challenges during transitional stages in medicine; the importance of role modeling; patient dehumanization; faking or overstating one's capabilities; unprofessionalism; the loss of idealism; and difficulties with work-life balance. The hidden curriculum is frequently depicted in popular medical television shows. These examples of the hidden curriculum could serve as a valuable teaching resource in undergraduate medical programs.

Survey of International Trade/Economics Textbooks.

ERIC Educational Resources Information Center

Lucier, Richard L.

1992-01-01

Reviews 14 international economics textbooks to help instructors with selection. Includes organization and structure, topics covered, and characteristics of the texts. Suggests considerations such as course length, level of abstraction desired, opinion of numerically based graphical analysis, extensiveness of examples and applications, and whether…

From designer Lewis acid to designer Brønsted acid towards more reactive and selective acid catalysis

PubMed Central

YAMAMOTO, Hisashi

2008-01-01

This review focuses on the development of acid catalysis for selective organic transformations conducted in our laboratories for the past 30 years. Several important concepts in designing of catalysts are described with some examples. Further, recent developments in super Brønsted acid and their applications in a one-pot procedure to construct complex molecules with high diastereoselectivities are described. PMID:18941293

On the importance of balancing selection in plants

PubMed Central

Delph, Lynda F.; Kelly, John K.

2013-01-01

Summary Balancing selection refers to a variety of selective regimes that maintain advantageous genetic diversity within populations. We review the history of the ideas regarding the types of selection that maintain such polymorphism in flowering plants, notably heterozygote advantage, negative frequency-dependent selection, and spatial heterogeneity. One shared feature of these mechanisms is that whether an allele is beneficial or detrimental is conditional on its frequency in the population. We highlight examples of balancing selection on a variety of discrete traits. These include the well-referenced case of self-incompatibility and recent evidence from species with nuclear-cytoplasmic gynodioecy, both of which exhibit trans-specific polymorphism, a hallmark of balancing selection. We also discuss and give examples of how spatial heterogeneity in particular, which is often thought unlikely to allow protected polymorphism, can maintain genetic variation in plants (which are rooted in place) as a result of microhabitat selection. Lastly, we discuss limitations of the protected polymorphism concept for quantitative traits, where selection can inflate the genetic variance without maintaining specific alleles indefinitely. We conclude that while discrete-morph variation provides the most unambiguous cases of protected polymorphism, they represent only a fraction of the balancing selection at work in plants. PMID:23952298

Artificial Intelligence in Cardiology.

PubMed

Johnson, Kipp W; Torres Soto, Jessica; Glicksberg, Benjamin S; Shameer, Khader; Miotto, Riccardo; Ali, Mohsin; Ashley, Euan; Dudley, Joel T

2018-06-12

Artificial intelligence and machine learning are poised to influence nearly every aspect of the human condition, and cardiology is not an exception to this trend. This paper provides a guide for clinicians on relevant aspects of artificial intelligence and machine learning, reviews selected applications of these methods in cardiology to date, and identifies how cardiovascular medicine could incorporate artificial intelligence in the future. In particular, the paper first reviews predictive modeling concepts relevant to cardiology such as feature selection and frequent pitfalls such as improper dichotomization. Second, it discusses common algorithms used in supervised learning and reviews selected applications in cardiology and related disciplines. Third, it describes the advent of deep learning and related methods collectively called unsupervised learning, provides contextual examples both in general medicine and in cardiovascular medicine, and then explains how these methods could be applied to enable precision cardiology and improve patient outcomes. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Retirement and Health Insurance: Finding New Solutions to the Benefits Puzzle.

ERIC Educational Resources Information Center

Stanley, Ron

1993-01-01

Presents guidelines for colleges on selecting employee health insurance carriers and retirement investment programs. Reviews types of insurance programs, presenting examples from several states. Discusses mechanisms for reducing insurance premiums, including claim reduction, self-funding, mail-order pharmaceuticals, and forming consortia with…

Equipment Efficiency for Healthy School Meals. [Videotape].

ERIC Educational Resources Information Center

National Food Service Management Inst., University, MS.

A satellite seminar on large-scale food production equipment discusses ways child nutrition personnel can maximize use of existing equipment, considers research related to use of existing equipment, explains plan reviews for equipment selection and purchase, and explores new equipment options. Examples illustrate use of planning or modernizing…

A Review and Annotated Bibliography of the Literature Pertaining to Team and Small Group Performance (1989 to 1999)

DTIC Science & Technology

1999-12-01

good interventions. This literature could be helpful to those who are planning changes or interventions concerning a wide variety of team-related...factors. Examples of input variables that can potentially be influenced by changes or interventions include the organizational reward system...through local resources or inter -library loans, the number of articles we reviewed was 200. From those 200, we selected approximately 80 articles

Current use was established and Cochrane guidance on selection of social theories for systematic reviews of complex interventions was developed.

PubMed

Noyes, Jane; Hendry, Maggie; Booth, Andrew; Chandler, Jackie; Lewin, Simon; Glenton, Claire; Garside, Ruth

2016-07-01

To identify examples of how social theories are used in systematic reviews of complex interventions to inform production of Cochrane guidance. Secondary analysis of published/unpublished examples of theories of social phenomena for use in reviews of complex interventions identified through scoping searches, engagement with key authors and methodologists supplemented by snowballing and reference searching. Theories were classified (low-level, mid-range, grand). Over 100 theories were identified with evidence of proliferation over the last 5 years. New low-level theories (tools, taxonomies, etc) have been developed for classifying and reporting complex interventions. Numerous mid-range theories are used; one example demonstrated how control theory had changed the review's findings. Review-specific logic models are increasingly used, but these can be challenging to develop. New low-level and mid-range psychological theories of behavior change are evolving. No reviews using grand theory (e.g., feminist theory) were identified. We produced a searchable Wiki, Mendeley Inventory, and Cochrane guidance. Use of low-level theory is common and evolving; incorporation of mid-range theory is still the exception rather than the norm. Methodological work is needed to evaluate the contribution of theory. Choice of theory reflects personal preference; application of theory is a skilled endeavor. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Screening tests: a review with examples

PubMed Central

Niebo, Ron; Utell, Mark J.

2014-01-01

Screening tests are widely used in medicine to assess the likelihood that members of a defined population have a particular disease. This article presents an overview of such tests including the definitions of key technical (sensitivity and specificity) and population characteristics necessary to assess the benefits and limitations of such tests. Several examples are used to illustrate calculations, including the characteristics of low dose computed tomography as a lung cancer screen, choice of an optimal PSA cutoff and selection of the population to undergo mammography. The importance of careful consideration of the consequences of both false positives and negatives is highlighted. Receiver operating characteristic curves are explained as is the need to carefully select the population group to be tested. PMID:25264934

Selective breeding in fish and conservation of genetic resources for aquaculture.

PubMed

Lind, C E; Ponzoni, R W; Nguyen, N H; Khaw, H L

2012-08-01

To satisfy increasing demands for fish as food, progress must occur towards greater aquaculture productivity whilst retaining the wild and farmed genetic resources that underpin global fish production. We review the main selection methods that have been developed for genetic improvement in aquaculture, and discuss their virtues and shortcomings. Examples of the application of mass, cohort, within family, and combined between-family and within-family selection are given. In addition, we review the manner in which fish genetic resources can be lost at the intra-specific, species and ecosystem levels and discuss options to best prevent this. We illustrate that fundamental principles of genetic management are common in the implementation of both selective breeding and conservation programmes, and should be emphasized in capacity development efforts. We highlight the value of applied genetics approaches for increasing aquaculture productivity and the conservation of fish genetic resources. © 2012 Blackwell Verlag GmbH.

Next-Generation Sequencing of Antibody Display Repertoires

PubMed Central

Rouet, Romain; Jackson, Katherine J. L.; Langley, David B.; Christ, Daniel

2018-01-01

In vitro selection technology has transformed the development of therapeutic monoclonal antibodies. Using methods such as phage, ribosome, and yeast display, high affinity binders can be selected from diverse repertoires. Here, we review strategies for the next-generation sequencing (NGS) of phage- and other antibody-display libraries, as well as NGS platforms and analysis tools. Moreover, we discuss recent examples relating to the use of NGS to assess library diversity, clonal enrichment, and affinity maturation. PMID:29472918

Internal Control Weaknesses Contributed to the Mismanagement and Misuse of Federal Funds at Selected Community Action Agencies.

DTIC Science & Technology

1981-07-10

reimbursement of expenses. --Inadequate control over fixed assets. Excess cash GAO reviewed several community action agencies and found that millions...buildings. (See pp. 10-13.) Duplicate reimbursement of expenses Some community action agencies and their dele- gates GAO reviewed have charged nearly...1 million of expenses to more than one Federal grant. For example, one agency received nearly $855,000 in dual reimbursements between July 1974 and

Water Quality and Brain Function

PubMed Central

Campbell, Arezoo

2017-01-01

In the United States, regulations are in place to ensure the quality of drinking water. Such precautions are intended to safeguard the health of the population. However, regulatory guidelines may at times fail to achieve their purpose. This may be due to lack of sufficient data regarding the health hazards of chronic low dose exposure to contaminants or the introduction of new substances that pose a health hazard risk that has yet to be identified. In this review, examples of different sources of contaminants in drinking water will be discussed, followed by an evaluation of some select individual toxicants with known adverse neurological impact. The ability of mixtures to potentially cause additive, synergistic, or antagonistic neurotoxic responses will be briefly addressed. The last section of the review will provide examples of select mechanisms by which different classes of contaminants may lead to neurological impairments. The main objective of this review is to bring to light the importance of considering trace amounts of chemicals in the drinking water and potential brain abnormalities. There is continued need for toxicology studies to better understand negative consequences of trace amounts of toxins and although it is beyond the scope of this brief overview it is hoped that the review will underscore the paucity of studies focused on determining how long-term exposure to minute levels of contaminants in drinking water may pose a significant health hazard. PMID:29267198

Antibiotic-Free Selection in Biotherapeutics: Now and Forever

PubMed Central

Mignon, Charlotte; Sodoyer, Régis; Werle, Bettina

2015-01-01

The continuously improving sophistication of molecular engineering techniques gives access to novel classes of bio-therapeutics and new challenges for their production in full respect of the strengthening regulations. Among these biologic agents are DNA based vaccines or gene therapy products and to a lesser extent genetically engineered live vaccines or delivery vehicles. The use of antibiotic-based selection, frequently associated with genetic manipulation of microorganism is currently undergoing a profound metamorphosis with the implementation and diversification of alternative selection means. This short review will present examples of alternatives to antibiotic selection and their context of application to highlight their ineluctable invasion of the bio-therapeutic world. PMID:25854922

Annual Report of the Commission on Physical Sciences, Mathematics, and Resources.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Physical Sciences, Mathematics, and Resources.

This report highlights and presents examples of the Commission on Physical Science, Mathematics, and Resources' (CPSMR) recent activities and future plans. Selected programs and activities from the 224 boards and committees that operate within CPSMR are reviewed. These range from studies of basic science to examinations of applied science and…

Aromatic Substitution Reactions: When You've Said Ortho, Meta, and Para, You Haven't Said It All.

ERIC Educational Resources Information Center

Traynham, James G.

1983-01-01

Recent investigations show that the ipso position competes effectively with unsubstituted positions in many aromatic substitution reactions, regardless of charge type of reaction. Selected examples available for nucleophilic, electrophilic, and free radical reactions are reviewed to suggest the range of ipso reactions. (JN)

Applications of Participatory Action Research with Students Who Have Disabilities. ERIC/OSEP Digest.

ERIC Educational Resources Information Center

Warger, Cynthia; Burnette, Jane

This brief paper defines participatory action research, reviews the literature on its use, and offers examples of how researchers and practitioners are applying principles of participatory action research data to select effective practices and support change and innovation in schools. Generation of data-based strategies in natural environments is…

Meta-Ethnography of Autoethnographies: A Worked Example of the Method Using Educational Studies

ERIC Educational Resources Information Center

Hughes, Sherick; Noblit, George

2017-01-01

Despite questions about autoethnography in the ethnography and education research family, autoethnography is published in selective peer-reviewed journals in education and in the social and health sciences. Even critics of autoethnographic studies note their "rising acceptance in the past 15 years" [Delamont, S. 2009. "The Only…

Plastic scintillators modifications for a selective radiation detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamel, Matthieu; Bertrand, Guillaume H.V.; Carrel, Frederick

2015-07-01

Recent developments of plastic scintillators are reviewed, from January 2000 to June 2015. All examples are distributed into the main application, i.e. how the plastic scintillator was modified to enhance the detection towards a given radiation particle. The main characteristics of these newly created scintillators and their detection properties are given. (authors)

Just What Are We Reading? Books on CD-ROM.

ERIC Educational Resources Information Center

Hammett, Roberta F.

1997-01-01

Discusses things for teachers to think about when selecting interactive books for their students, for example: whether the review was written by those in the software business or by educators; whether diverse possibilities for school use exist; whether the books are free of gender, racial, and class stereotypes; and whether the interactive book…

Rational decision-making in mental health: the role of systematic reviews.

PubMed

Gilbody, Simon M.; Petticrew, Mark

1999-09-01

BACKGROUND: "Systematic reviews" have come to be recognized as the most rigorous method of summarizing confusing and often contradictory primary research in a transparent and reproducible manner. Their greatest impact has been in the summarization of epidemiological literature - particularly that relating to clinical effectiveness. Systematic reviews also have a potential to inform rational decision-making in healthcare policy and to form a component of economic evaluation. AIMS OF THE STUDY: This article aims to introduce the rationale behind systematic reviews and, using examples from mental health, to introduce the strengths and limitations of systematic reviews, particularly in informing mental health policy and economic evaluation. METHODS: Examples are selected from recent controversies surrounding the introduction of new psychiatric drugs (anti-depressants and anti-schizophrenia drugs) and methods of delivering psychiatric care in the community (case management and assertive community treatment). The potential for systematic reviews to (i) produce best estimates of clinical efficacy and effectiveness, (ii) aid economic evaluation and policy decision-making and (iii) highlight gaps in the primary research knowledge base are discussed. Lastly examples are selected from outside mental health to show how systematic reviews have a potential to be explicitly used in economic and health policy evaluation. RESULTS: Systematic reviews produce the best estimates of clinical efficacy, which can form an important component of economic evaluation. Importantly, serious methodological flaws and areas of uncertainty in the primary research literature are identified within an explicit framework. Summary indices of clinical effectiveness can be produced, but it is difficult to produce such summary indices of cost effectiveness by pooling economic data from primary studies. Modelling is commonly used in economic and policy evaluation. Here, systematic reviews can provide the best estimates of effectiveness and, importantly, highlight areas of uncertainty that can be used in "sensitivity analysis". DISCUSSION: Systematic reviews are an important recent methodological advance, the potential for which has only begun to be realized in mental health. This use of systematic reviews is probably most advanced in producing critical summaries of clinical effectiveness data. Systematic reviews cannot produce valid and believable conclusions when the primary research literature is of poor quality. An important function of systematic reviews will be in highlighting this poor quality research which is of little use in mental health decision making. IMPLICATIONS FOR HEALTH PROVISION: Health care provision should be both clinically and cost effective. Systematic reviews are a key component in ensuring that this goal is achieved. IMPLICATIONS FOR HEALTH POLICIES: Systematic reviews have potential to inform health policy. Examples presented show that health policy is often made without due consideration of the research evidence. Systematic reviews can provide robust and believable answers, which can help inform rational decision-making. Importantly, systematic reviews can highlight the need for important primary research and can inform the design of this research such that it provides answers that will help in forming healthcare policy. IMPLICATIONS FOR FURTHER RESEARCH: Systematic reviews should precede costly (and often unnecessary) primary research. Many areas of health policy and practice have yet to be evaluated using systematic review methodology. Methods for the summarization of economic data are methodologically complex and deserve further research

Incorporation of Graphene-Related Carbon Nanosheets in Membrane Fabrication for Water Treatment: A Review

PubMed Central

Lawler, Jenny

2016-01-01

The minimization of the trade-off between the flux and the selectivity of membranes is a key area that researchers are continually working to optimise, particularly in the area of fabrication of novel membranes. Flux versus selectivity issues apply in many industrial applications of membranes, for example the unwanted diffusion of methanol in fuel cells, retention of valuable proteins in downstream processing of biopharmaceuticals, rejection of organic matter and micro-organisms in water treatment, or salt permeation in desalination. The incorporation of nanosheets within membrane structures can potentially lead to enhancements in such properties as the antifouling ability, hydrophilicy and permeability of membranes, with concomitant improvements in the flux/selectivity balance. Graphene nanosheets and derivatives such as graphene oxide and reduced graphene oxide have been investigated for this purpose, for example inclusion of nanosheets within the active layer of Reverse Osmosis or Nanofiltration membranes or the blending of nanosheets as fillers within Ultrafiltration membranes. This review summarizes the incorporation of graphene derivatives into polymeric membranes for water treatment with a focus on a number of industrial applications, including desalination and pharmaceutical removal, where enhancement of productivity and reduction in fouling characteristics have been afforded by appropriate incorporation of graphene derived nanosheets during membrane fabrication. PMID:27999364

Enhancing High Value Care in Gastroenterology Practice.

PubMed

Camilleri, Michael; Katzka, David A

2016-10-01

The objective of this review is to identify common areas in gastroenterology practice where studies performed provide an opportunity for enhancing value or lowering costs. We provide examples of topics in gastroenterology where clinicians could enhance value by either using less invasive testing, choosing a single best test, or by using patient symptoms to guide additional testing. The topics selected for review are selected in esophageal, pancreatic, and colorectal cancer; functional gastrointestinal diseases (irritable bowel syndrome, bacterial overgrowth, constipation); immune-mediated gastrointestinal diseases; and pancreaticobiliary pathology. We propose guidance to alter practice based on current evidence. These studies support the need to review current practice and to continue performing research to further validate the proposed guidance to enhance value of care in gastroenterology and hepatology. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Estimating Alarm Thresholds for Process Monitoring Data under Different Assumptions about the Data Generating Mechanism

DOE PAGES

Burr, Tom; Hamada, Michael S.; Howell, John; ...

2013-01-01

Process monitoring (PM) for nuclear safeguards sometimes requires estimation of thresholds corresponding to small false alarm rates. Threshold estimation dates to the 1920s with the Shewhart control chart; however, because possible new roles for PM are being evaluated in nuclear safeguards, it is timely to consider modern model selection options in the context of threshold estimation. One of the possible new PM roles involves PM residuals, where a residual is defined as residual = data − prediction. This paper reviews alarm threshold estimation, introduces model selection options, and considers a range of assumptions regarding the data-generating mechanism for PM residuals.more » Two PM examples from nuclear safeguards are included to motivate the need for alarm threshold estimation. The first example involves mixtures of probability distributions that arise in solution monitoring, which is a common type of PM. The second example involves periodic partial cleanout of in-process inventory, leading to challenging structure in the time series of PM residuals.« less

Promising Parenting Programs for Reducing Adolescent Problem Behaviors

PubMed Central

Haggerty, Kevin P.; McGlynn-Wright, Anne; Klima, Tali

2013-01-01

Purpose Adolescent problem behaviors (substance use, delinquency, school dropout, pregnancy, and violence) are costly not only for individuals, but for entire communities. Policymakers and practitioners that are interested in preventing these problem behaviors are faced with many programming options. In this review, we discuss two criteria for selecting relevant parenting programs, and provide five examples of such programs. Design/methodology/approach The first criterion for program selection is theory based. Well-supported theories, such as the social development model, have laid out key family-based risk and protective factors for problem behavior. Programs that target these risk and protective factors are more likely to be effective. Second, programs should have demonstrated efficacy; these interventions have been called “evidence-based programs” (EBP). This review highlights the importance of evidence from rigorous research designs, such as randomized clinical trials, in order to establish program efficacy. Findings Nurse-Family Partnership, The Incredible Years, Positive Parenting Program, Strengthening Families 10–14, and Staying Connected with Your Teen are examined. The unique features of each program are briefly presented. Evidence showing impact on family risk and protective factors, as well as long-term problem behaviors, is reviewed. Finally, a measure of cost effectiveness of each program is provided. Originality/value We propose that not all programs are of equal value, and suggest two simple criteria for selecting a parenting program with a high likelihood for positive outcomes. Furthermore, although this review is not exhaustive, the five examples of EBPs offer a good start for policymakers and practitioners seeking to implement effective programs in their communities. Thus, this paper offers practical suggestions for those grappling with investments in child and adolescent programs on the ground. PMID:24416068

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

PubMed Central

2011-01-01

Summary This review presents a comprehensive overview on selected synthetic routes towards commercial drug compounds as published in both journal and patent literature. Owing to the vast number of potential structures, we have concentrated only on those drugs containing five-membered heterocycles and focused principally on the assembly of the heterocyclic core. In order to target the most representative chemical entities the examples discussed have been selected from the top 200 best selling drugs of recent years. PMID:21647262

Directed evolution of stereoselective enzymes based on genetic selection as opposed to screening systems.

PubMed

Acevedo-Rocha, Carlos G; Agudo, Ruben; Reetz, Manfred T

2014-12-10

Directed evolution of stereoselective enzymes provides a means to generate useful biocatalysts for asymmetric transformations in organic chemistry and biotechnology. Almost all of the numerous examples reported in the literature utilize high-throughput screening systems based on suitable analytical techniques. Since the screening step is the bottleneck of the overall procedure, researchers have considered the use of genetic selection systems as an alternative to screening. In principle, selection would be the most elegant and efficient approach because it is based on growth advantage of host cells harboring stereoselective mutants, but devising such selection systems is very challenging. They must be designed so that the host organism profits from the presence of an enantioselective variant. Progress in this intriguing research area is summarized in this review, which also includes some examples of display systems designed for enantioselectivity as assayed by fluorescence-activated cell sorting (FACS). Although the combination of display systems and FACS is a powerful approach, we also envision innovative ideas combining metabolic engineering and genetic selection systems with protein directed evolution for the development of highly selective and efficient biocatalysts. Copyright © 2014 Elsevier B.V. All rights reserved.

Charting the Nation’s Course: Strategic Planning Processes in the 1952-53 New Look and the 1996-97 Quadrennial Defense Review

DTIC Science & Technology

1998-06-01

the Nation’s Course : Strategic Planning Processes in the 1952-53 " New Look" and the 1996-97 Quadrennial...sequences into a cohesive whole. Two examples ( the New Look of 1953 and the Quadrennial Defense Review of 1997) are selected for comparison due to the many...By 1953, atomic weapons were becoming more numerous and hydrogen weapons were about to be tested for the first time. 17 Bombers, cruise missiles,

Jackknifing Techniques for Evaluation of Equating Accuracy. Research Report. ETS RR-09-39

ERIC Educational Resources Information Center

Haberman, Shelby J.; Lee, Yi-Hsuan; Qian, Jiahe

2009-01-01

Grouped jackknifing may be used to evaluate the stability of equating procedures with respect to sampling error and with respect to changes in anchor selection. Properties of grouped jackknifing are reviewed for simple-random and stratified sampling, and its use is described for comparisons of anchor sets. Application is made to examples of item…

Within-host competitive interactions as a mechanism for the maintenance of parasite diversity

PubMed Central

Bashey, Farrah

2015-01-01

Variation among parasite strains can affect the progression of disease or the effectiveness of treatment. What maintains parasite diversity? Here I argue that competition among parasites within the host is a major cause of variation among parasites. The competitive environment within the host can vary depending on the parasite genotypes present. For example, parasite strategies that target specific competitors, such as bacteriocins, are dependent on the presence and susceptibility of those competitors for success. Accordingly, which parasite traits are favoured by within-host selection can vary from host to host. Given the fluctuating fitness landscape across hosts, genotype by genotype (G×G) interactions among parasites should be prevalent. Moreover, selection should vary in a frequency-dependent manner, as attacking genotypes select for resistance and genotypes producing public goods select for cheaters. I review competitive coexistence theory with regard to parasites and highlight a few key examples where within-host competition promotes diversity. Finally, I discuss how within-host competition affects host health and our ability to successfully treat infectious diseases. PMID:26150667

Selective crystallization with preferred lithium-ion storage capability of inorganic materials

PubMed Central

2012-01-01

Lithium-ion batteries are supposed to be a key method to make a more efficient use of energy. In the past decade, nanostructured electrode materials have been extensively studied and have presented the opportunity to achieve superior performance for the next-generation batteries which require higher energy and power densities and longer cycle life. In this article, we reviewed recent research activities on selective crystallization of inorganic materials into nanostructured electrodes for lithium-ion batteries and discuss how selective crystallization can improve the electrode performance of materials; for example, selective exposure of surfaces normal to the ionic diffusion paths can greatly enhance the ion conductivity of insertion-type materials; crystallization of alloying-type materials into nanowire arrays has proven to be a good solution to the electrode pulverization problem; and constructing conversion-type materials into hollow structures is an effective approach to buffer the volume variation during cycling. The major goal of this review is to demonstrate the importance of crystallization in energy storage applications. PMID:22353373

TLS from fundamentals to practice

PubMed Central

Urzhumtsev, Alexandre; Afonine, Pavel V.; Adams, Paul D.

2014-01-01

The Translation-Libration-Screw-rotation (TLS) model of rigid-body harmonic displacements introduced in crystallography by Schomaker & Trueblood (1968) is now a routine tool in macromolecular studies and is a feature of most modern crystallographic structure refinement packages. In this review we consider a number of simple examples that illustrate important features of the TLS model. Based on these examples simplified formulae are given for several special cases that may occur in structure modeling and refinement. The derivation of general TLS formulae from basic principles is also provided. This manuscript describes the principles of TLS modeling, as well as some select algorithmic details for practical application. An extensive list of applications references as examples of TLS in macromolecular crystallography refinement is provided. PMID:25249713

Practical physics behind growing crystals of biological macromolecules.

PubMed

Candoni, Nadine; Grossier, Romain; Hammadi, Zoubida; Morin, Roger; Veesler, Stéphane

2012-07-01

The aim of this review is to provide biocrystallographers who intend to tackle protein-crystallization with theory and practical examples. Crystallization involves two separate processes, nucleation and growth, which are rarely completely unconnected. Here we give theoretical background and concrete examples illustrating protein crystallization. We describe the nucleation of a new phase, solid or liquid, and the growth and transformation of existing crystals obtained by primary or secondary nucleation or by seeding. Above all, we believe that a thorough knowledge of the phase diagram is vital to the selection of starting position and path for any crystallization experiment.

Selective progesterone receptor modulators 3: use in oncology, endocrinology and psychiatry.

PubMed

Benagiano, Giuseppe; Bastianelli, Carlo; Farris, Manuela

2008-10-01

A number of synthetic steroids are capable of modulating progesterone receptors with a spectrum of activities ranging from pure antagonism to a mixture of agonism and antagonism. The best known of these are mifepristone (RU 486), asoprisnil (J 867), onapristone (ZK 98299), ulipristal (CDB 2914), Proellex() (CDB 4124), ORG 33628 and ORG 31710. Outside reproduction selective modulators of progesterone receptors have been under investigation for a large variety of indications, for example in oncology as adjuvants in breast, cervical, endometrial, ovarian and prostate cancer, as well as inoperable meningioma and leiomyosarcoma. In addition, they have been used as antiglucocorticoids. It is therefore useful to review the results obtained in these conditions. A careful evaluation of existing major review papers and of recently published articles was carried out for the indications under review, focusing not only on mifepristone but also on those other selective modulators of progesterone receptors for which data are available. In preliminary studies selective modulators of progesterone receptors had some activity on a number of neoplasias. Their antiglucocorticoid activity has been tested with some success in Cushing's syndrome, several psychiatric conditions (e.g., mood disorders and Alzheimer's disease) and acute renal failure. Finally they are being used in a gene regulator system.

Exploring selection and recruitment processes for newly qualified nurses: a sequential-explanatory mixed-method study.

PubMed

Newton, Paul; Chandler, Val; Morris-Thomson, Trish; Sayer, Jane; Burke, Linda

2015-01-01

To map current selection and recruitment processes for newly qualified nurses and to explore the advantages and limitations of current selection and recruitment processes. The need to improve current selection and recruitment practices for newly qualified nurses is highlighted in health policy internationally. A cross-sectional, sequential-explanatory mixed-method design with 4 components: (1) Literature review of selection and recruitment of newly qualified nurses; and (2) Literature review of a public sector professions' selection and recruitment processes; (3) Survey mapping existing selection and recruitment processes for newly qualified nurses; and (4) Qualitative study about recruiters' selection and recruitment processes. Literature searches on the selection and recruitment of newly qualified candidates in teaching and nursing (2005-2013) were conducted. Cross-sectional, mixed-method data were collected from thirty-one (n = 31) individuals in health providers in London who had responsibility for the selection and recruitment of newly qualified nurses using a survey instrument. Of these providers who took part, six (n = 6) purposively selected to be interviewed qualitatively. Issues of supply and demand in the workforce, rather than selection and recruitment tools, predominated in the literature reviews. Examples of tools to measure values, attitudes and skills were found in the nursing literature. The mapping exercise found that providers used many selection and recruitment tools, some providers combined tools to streamline process and assure quality of candidates. Most providers had processes which addressed the issue of quality in the selection and recruitment of newly qualified nurses. The 'assessment centre model', which providers were adopting, allowed for multiple levels of assessment and streamlined recruitment. There is a need to validate the efficacy of the selection tools. © 2014 John Wiley & Sons Ltd.

A selective review of selective attention research from the past century.

PubMed

Driver, Jon

2001-02-01

Research on attention is concerned with selective processing of incoming sensory information. To some extent, our awareness of the world depends on what we choose to attend, not merely on the stimulation entering our senses. British psychologists have made substantial contributions to this topic in the past century. Celebrated examples include Donald Broadbent's filter theory of attention, which set the agenda for most subsequent work; and Anne Treisman's revisions of this account, and her later feature-integration theory. More recent contributions include Alan Allport's prescient emphasis on the relevance of neuroscience data, and John Duncan's integration of such data with psychological theory. An idiosyncratic but roughly chronological review of developments is presented, some practical and clinical implications are briefly sketched, and future directions suggested. One of the biggest changes in the field has been the increasing interplay between psychology and neuroscience, which promises much for the future. A related change has been the realization that selection attention is best thought of as a broad topic, encompassing a range of selective issues, rather than as a single explanatory process.

GENDER DIFFERENCES IN PERCEPTIONS OF SEXUAL INTENT: A QUALITATIVE REVIEW AND INTEGRATION

PubMed Central

Lindgren, Kristen P.; Parkhill, Michele R.; George, William H.; Hendershot, Christian S.

2009-01-01

Men appear to interpret people’s behaviors more sexually than do women. This finding, which has been replicated in scores of studies using a variety of methodological approaches, has been linked to important social concerns, including sexual assault and sexual harassment. This article provides a critical review of the published literature on gender differences in sexual intent perception, using selective examples to illustrate and summarize the field’s major constructs, methodologies, and empirical findings. Theoretical explanations for gender differences in sexual intent perceptions are reviewed. Finally, we highlight the field’s remaining issues and make several recommendations for future research directions. PMID:19763282

Catalysts for CO2/epoxide ring-opening copolymerization

PubMed Central

Trott, G.; Saini, P. K.; Williams, C. K.

2016-01-01

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to control the composition, properties and applications of the resultant polymers. This review highlights and exemplifies some key recent findings and hypotheses, in particular using examples drawn from our own research. PMID:26755758

Assessing cooperativity in supramolecular systems.

PubMed

von Krbek, Larissa K S; Schalley, Christoph A; Thordarson, Pall

2017-05-09

This tutorial review summarises different aspects of cooperativity in supramolecular complexes. We propose a systematic categorisation of cooperativity into cooperative aggregation, intermolecular (allosteric) cooperativity, intramolecular (chelate) cooperativity and interannular cooperativity and discuss approaches to quantify them thermodynamically using cooperativity factors. A brief summary of methods to determine the necessary thermodynamic data is given with emphasis on isothermal titration calorimetry (ITC), a method still underrepresented in supramolecular chemistry, which however offers some advantages over others. Finally, a discussion of very few selected examples, which highlight different aspects to illustrate why such an analysis is useful, rounds up this review.

Study of Strategies Used in Online Searching: 2. Positional Logic--an Example of the Importance of Selecting the Right Boolean Operator.

ERIC Educational Resources Information Center

Oldroyd, Betty K.; Schroder, J. J.

1982-01-01

Reviews the advantages and disadvantages of different types of term combination using the positional logic capability of online information retrieval systems and describes a study in which searches for material on "microwave integrated circuits" were conducted in order to find the most economical way of generating the most relevant…

Manipulating measurement scales in medical statistical analysis and data mining: A review of methodologies

PubMed Central

Marateb, Hamid Reza; Mansourian, Marjan; Adibi, Peyman; Farina, Dario

2014-01-01

Background: selecting the correct statistical test and data mining method depends highly on the measurement scale of data, type of variables, and purpose of the analysis. Different measurement scales are studied in details and statistical comparison, modeling, and data mining methods are studied based upon using several medical examples. We have presented two ordinal–variables clustering examples, as more challenging variable in analysis, using Wisconsin Breast Cancer Data (WBCD). Ordinal-to-Interval scale conversion example: a breast cancer database of nine 10-level ordinal variables for 683 patients was analyzed by two ordinal-scale clustering methods. The performance of the clustering methods was assessed by comparison with the gold standard groups of malignant and benign cases that had been identified by clinical tests. Results: the sensitivity and accuracy of the two clustering methods were 98% and 96%, respectively. Their specificity was comparable. Conclusion: by using appropriate clustering algorithm based on the measurement scale of the variables in the study, high performance is granted. Moreover, descriptive and inferential statistics in addition to modeling approach must be selected based on the scale of the variables. PMID:24672565

Supramolecular chemistry-general principles and selected examples from anion recognition and metallosupramolecular chemistry.

PubMed

Albrecht, Markus

2007-12-01

This review gives an introduction into supramolecular chemistry describing in the first part general principles, focusing on terms like noncovalent interaction, molecular recognition, self-assembly, and supramolecular function. In the second part those will be illustrated by simple examples from our laboratories. Supramolecular chemistry is the science that bridges the gap between the world of molecules and nanotechnology. In supramolecular chemistry noncovalent interactions occur between molecular building blocks, which by molecular recognition and self-assembly form (functional) supramolecular entities. It is also termed the "chemistry of the noncovalent bond." Molecular recognition is based on geometrical complementarity based on the "key-and-lock" principle with nonshape-dependent effects, e.g., solvatization, being also highly influential. Self-assembly leads to the formation of well-defined aggregates. Hereby the overall structure of the target ensemble is controlled by the symmetry features of the certain building blocks. Finally, the aggregates can possess special properties or supramolecular functions, which are only found in the ensemble but not in the participating molecules. This review gives an introduction on supramolecular chemistry and illustrates the fundamental principles by recent examples from our group.

A comprehensive review of select smart polymeric and gel actuators for soft mechatronics and robotics applications: fundamentals, freeform fabrication, and motion control

NASA Astrophysics Data System (ADS)

Carrico, James D.; Tyler, Tom; Leang, Kam K.

2017-10-01

Smart polymeric and gel actuators change shape or size in response to stimuli like electricity, heat, or light. These smart polymeric- and gel-based actuators are compliant and well suited for development of soft mechatronic and robotic devices. This paper provides a thorough review of select smart polymeric and gel actuator materials where an automated and freeform fabrication process, like 3D printing, is exploited to create custom shaped monolithic devices. In particular, the advantages and limitations, examples of applications, manufacturing and fabrication techniques, and methods for actuator control are discussed. Finally, a rigorous comparison and analysis of some of the advantages and limitations, as well as manufacturing processes, for these materials, are presented.

Reporting Guidelines: Optimal Use in Preventive Medicine and Public Health

PubMed Central

Popham, Karyn; Calo, William A.; Carpentier, Melissa Y.; Chen, Naomi E.; Kamrudin, Samira A.; Le, Yen-Chi L.; Skala, Katherine A.; Thornton, Logan R.; Mullen, Patricia Dolan

2012-01-01

Numerous reporting guidelines are available to help authors write higher quality manuscripts more efficiently. Almost 200 are listed on the EQUATOR (Enhancing the Quality and Transparency of Health Research) Network’s website and they vary in authority, usability, and breadth, making it difficult to decide which one(s) to use. This paper provides consistent information about guidelines for preventive medicine and public health and a framework and sequential approach for selecting them. EQUATOR guidelines were reviewed for relevance to target audiences; selected guidelines were classified as “core” (frequently recommended) or specialized, and the latter were grouped by their focus. Core and specialized guidelines were coded for indicators of authority (simultaneous publication in multiple journals, rationale, scientific background supporting each element, expertise of designers, permanent website/named group), usability (presence of checklists and examples of good reporting), and breadth (manuscript sections covered). Discrepancies were resolved by consensus. Selected guidelines are presented in four tables arranged to facilitate selection: core guidelines, all of which pertain to major research designs; guidelines for additional study designs, topical guidelines, and guidelines for particular manuscript sections. A flow diagram provides an overview. The framework and sequential approach will enable authors as well as editors, peer reviewers, researchers, and systematic reviewers to make optimal use of available guidelines to improve the transparency, clarity, and rigor of manuscripts and research protocols and the efficiency of conducing systematic reviews and meta-analyses. PMID:22992369

Fracture control procedures for aircraft structural integrity

NASA Technical Reports Server (NTRS)

Wood, H. A.

1972-01-01

The application of applied fracture mechanics in the design, analysis, and qualification of aircraft structural systems are reviewed. Recent service experiences are cited. Current trends in high-strength materials application are reviewed with particular emphasis on the manner in which fracture toughness and structural efficiency may affect the material selection process. General fracture control procedures are reviewed in depth with specific reference to the impact of inspectability, structural arrangement, and material on proposed analysis requirements for safe crack growth. The relative impact on allowable design stress is indicated by example. Design criteria, material, and analysis requirements for implementation of fracture control procedures are reviewed together with limitations in current available data techniques. A summary of items which require further study and attention is presented.

Structures of membrane proteins

PubMed Central

Vinothkumar, Kutti R.; Henderson, Richard

2010-01-01

In reviewing the structures of membrane proteins determined up to the end of 2009, we present in words and pictures the most informative examples from each family. We group the structures together according to their function and architecture to provide an overview of the major principles and variations on the most common themes. The first structures, determined 20 years ago, were those of naturally abundant proteins with limited conformational variability, and each membrane protein structure determined was a major landmark. With the advent of complete genome sequences and efficient expression systems, there has been an explosion in the rate of membrane protein structure determination, with many classes represented. New structures are published every month and more than 150 unique membrane protein structures have been determined. This review analyses the reasons for this success, discusses the challenges that still lie ahead, and presents a concise summary of the key achievements with illustrated examples selected from each class. PMID:20667175

Single-Chain Folding of Synthetic Polymers: A Critical Update.

PubMed

Altintas, Ozcan; Barner-Kowollik, Christopher

2015-11-23

The current contribution serves as a critical update to a previous feature article from us (Macromol. Rapid Commun. 2012, 33, 958-971), and highlights the latest advances in the preparation of single chain polymeric nanoparticles and initial-yet promising-attempts towards mimicking the structure of natural biomacromolecules via single-chain folding of well-defined linear polymers via so-called single chain selective point folding and repeat unit folding. The contribution covers selected examples from the literature published up to ca. September 2015. Our aim is not to provide an exhaustive review but rather highlight a selection of new and exciting examples for single-chain folding based on advanced macromolecular precision chemistry. Initially, the discussion focuses on the synthesis and characterization of single-chain folded structures via selective point folding. The second part of the feature article addresses the folding of well-defined single-chain polymers by means of repeat unit folding. The current state of the art in the field of single-chain folding indicates that repeat unit folding-driven nanoparticle preparation is well-advanced, while initial encouraging steps towards building selective point folding systems have been taken. In addition, a summary of the-in our view-open key questions is provided that may guide future biomimetic design efforts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hospital closure: a review of current and proposed research.

PubMed Central

Hernandez, S R; Kaluzny, A D

1983-01-01

This paper reviews available data describing issues and research findings with implications for hospital closings. Factors contributing to fiscal problems of hospitals (e.g., inadequate reimbursement, inflation, management problems, organizational structure, societal factors) are discussed. Selected studies offering examples of hospital and community characteristics associated with closure are presented. This review suggests that future directions for research should focus not only on hospital cost control but also on insuring equity in the distribution of hospital services. Specifically, research is needed that further describes the hospital closure phenomenon, the effects of closure, and the policy choices that might be pursued to insure equity in the continuation of hospital services to disadvantaged populations. PMID:6360954

Physical models of collective cell motility: from cell to tissue

NASA Astrophysics Data System (ADS)

Camley, B. A.; Rappel, W.-J.

2017-03-01

In this article, we review physics-based models of collective cell motility. We discuss a range of techniques at different scales, ranging from models that represent cells as simple self-propelled particles to phase field models that can represent a cell’s shape and dynamics in great detail. We also extensively review the ways in which cells within a tissue choose their direction, the statistics of cell motion, and some simple examples of how cell-cell signaling can interact with collective cell motility. This review also covers in more detail selected recent works on collective cell motion of small numbers of cells on micropatterns, in wound healing, and the chemotaxis of clusters of cells.

Methodology of oral formulation selection in the pharmaceutical industry.

PubMed

Kuentz, Martin; Holm, René; Elder, David P

2016-05-25

Pharmaceutical formulations have to fulfil various requirements with respect to their intended use, either in the development phase or as a commercial product. New drug candidates with their specific properties confront the formulation scientist with industrial challenges for which a strategy is needed to cope with limited resources, stretched timelines as well as regulatory requirements. This paper aims at reviewing different methodologies to select a suitable formulation approach for oral delivery. Exclusively small-molecular drugs are considered and the review is written from an industrial perspective. Specific cases are discussed starting with an emphasis on poorly soluble compounds, then the topics of chemically labile drugs, low-dose compounds, and modified release are reviewed. Due to the broad scope of this work, a primary focus is on explaining basic concepts as well as recent trends. Different strategies are discussed to approach industrial formulation selection, which includes a structured product development. Examples for such structured development aim to provide guidance to formulators and finally, the recent topic of a manufacturing classification system is presented. It can be concluded that the field of oral formulation selection is particularly complex due to both multiple challenges as well as opportunities so that industrial scientists have to employ tailored approaches to design formulations successfully. Copyright © 2015 Elsevier B.V. All rights reserved.

Making literature reviews more reliable through application of lessons from systematic reviews.

PubMed

Haddaway, N R; Woodcock, P; Macura, B; Collins, A

2015-12-01

Review articles can provide valuable summaries of the ever-increasing volume of primary research in conservation biology. Where findings may influence important resource-allocation decisions in policy or practice, there is a need for a high degree of reliability when reviewing evidence. However, traditional literature reviews are susceptible to a number of biases during the identification, selection, and synthesis of included studies (e.g., publication bias, selection bias, and vote counting). Systematic reviews, pioneered in medicine and translated into conservation in 2006, address these issues through a strict methodology that aims to maximize transparency, objectivity, and repeatability. Systematic reviews will always be the gold standard for reliable synthesis of evidence. However, traditional literature reviews remain popular and will continue to be valuable where systematic reviews are not feasible. Where traditional reviews are used, lessons can be taken from systematic reviews and applied to traditional reviews in order to increase their reliability. Certain key aspects of systematic review methods that can be used in a context-specific manner in traditional reviews include focusing on mitigating bias; increasing transparency, consistency, and objectivity, and critically appraising the evidence and avoiding vote counting. In situations where conducting a full systematic review is not feasible, the proposed approach to reviewing evidence in a more systematic way can substantially improve the reliability of review findings, providing a time- and resource-efficient means of maximizing the value of traditional reviews. These methods are aimed particularly at those conducting literature reviews where systematic review is not feasible, for example, for graduate students, single reviewers, or small organizations. © 2015 Society for Conservation Biology.

Protein Complex Production from the Drug Discovery Standpoint.

PubMed

Moarefi, Ismail

2016-01-01

Small molecule drug discovery critically depends on the availability of meaningful in vitro assays to guide medicinal chemistry programs that are aimed at optimizing drug potency and selectivity. As it becomes increasingly evident, most disease relevant drug targets do not act as a single protein. In the body, they are instead generally found in complex with protein cofactors that are highly relevant for their correct function and regulation. This review highlights selected examples of the increasing trend to use biologically relevant protein complexes for rational drug discovery to reduce costly late phase attritions due to lack of efficacy or toxicity.

Enantioselective determination by capillary electrophoresis with cyclodextrins as chiral selectors.

PubMed

Fanali, S

2000-04-14

This review surveys the separation of enantiomers by capillary electrophoresis using cyclodextrins as chiral selector. Cyclodextrins or their derivatives have been widely employed for the direct chiral resolution of a wide number of enantiomers, mainly of pharmaceutical interest, selected examples are reported in the tables. For method optimisation, several parameters influencing the enantioresolution, e.g., cyclodextrin type and concentration, buffer pH and composition, presence of organic solvents or complexing additives in the buffer were considered and discussed. Finally, selected applications to real samples such as pharmaceutical formulations, biological and medical samples are also discussed.

Applications of Piezoelectric Materials in Structural Health Monitoring and Repair: Selected Research Examples

PubMed Central

Duan, Wen Hui; Wang, Quan; Quek, Ser Tong

2010-01-01

The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined. PMID:28883375

Resolving ethical issues in stem cell clinical trials: the example of Parkinson disease.

PubMed

Lo, Bernard; Parham, Lindsay

2010-01-01

Clinical trials of stem cell transplantation raise ethical issues that are intertwined with scientific and design issues, including choice of control group and intervention, background interventions, endpoints, and selection of subjects. We recommend that the review and IRB oversight of stem cell clinical trials should be strengthened. Scientific and ethics review should be integrated in order to better assess risks and potential benefits. Informed consent should be enhanced by assuring that participants comprehend key aspects of the trial. For the trial to yield generalizable knowledge, negative findings and serious adverse events must be reported.

The NASA Electronic Parts and Packaging (NEPP) Program: Results and Direction

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2007-01-01

The NASA Electronic Parts and Packaging (NEPP) Program's mission is to provide guidance to NASA for the selection and application of microelectronic technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission assurance needs. This viewgraph presentation reviews the NEPP program's goals and objectives, and reviews many of the missions that the NEPP program has impacted, both in and out of NASA. Also included are examples of the evaluation that the program performed.

Disappearing Polymorphs Revisited

PubMed Central

Bučar, Dejan-Krešimir; Lancaster, Robert W; Bernstein, Joel

2015-01-01

Nearly twenty years ago, Dunitz and Bernstein described a selection of intriguing cases of polymorphs that disappear. The inability to obtain a crystal form that has previously been prepared is indeed a frustrating and potentially serious problem for solid-state scientists. This Review discusses recent occurrences and examples of disappearing polymorphs (as well as the emergence of elusive crystal forms) to demonstrate the enduring relevance of this troublesome, but always captivating, phenomenon in solid-state research. A number of these instances have been central issues in patent litigations. This Review, therefore, also highlights the complex relationship between crystal chemistry and the law. PMID:26031248

Wear of seal materials used in aircraft propulsion systems

NASA Technical Reports Server (NTRS)

Bill, R. C.; Ludwig, L. P.

1978-01-01

The various types of seal locations in a gas turbine engine are described, and the significance of wear to each type is reviewed. Starting with positive contact shaft seals, existing material selection guidelines are reviewed, and the existing PV (contact pressure X sliding velocity) criteria for selecting seal materials are discussed, along with the theoretical background for these criteria. Examples of wear mechanisms observed to operate in positive contact seals are shown. Design features that can extend the operating capabilities of positive contact seals, including pressure balancing and incorporation of hydrodynamic lift are briefly discussed. It is concluded that, despite the benefits arising from these design features, improved positive contact seal materials from the standpoint of wear, erosion and oxidation resistance will be necessary for further improvements in seal performance and durability, and to meet stringent future challenges.

Scientific Progress or Regress in Sports Physiology?

PubMed

Böning, Dieter

2016-11-01

In modern societies there is strong belief in scientific progress, but, unfortunately, a parallel partial regress occurs because of often avoidable mistakes. Mistakes are mainly forgetting, erroneous theories, errors in experiments and manuscripts, prejudice, selected publication of "positive" results, and fraud. An example of forgetting is that methods introduced decades ago are used without knowing the underlying theories: Basic articles are no longer read or cited. This omission may cause incorrect interpretation of results. For instance, false use of actual base excess instead of standard base excess for calculation of the number of hydrogen ions leaving the muscles raised the idea that an unknown fixed acid is produced in addition to lactic acid during exercise. An erroneous theory led to the conclusion that lactate is not the anion of a strong acid but a buffer. Mistakes occur after incorrect application of a method, after exclusion of unwelcome values, during evaluation of measurements by false calculations, or during preparation of manuscripts. Co-authors, as well as reviewers, do not always carefully read papers before publication. Peer reviewers might be biased against a hypothesis or an author. A general problem is selected publication of positive results. An example of fraud in sports medicine is the presence of doped subjects in groups of investigated athletes. To reduce regress, it is important that investigators search both original and recent articles on a topic and conscientiously examine the data. All co-authors and reviewers should read the text thoroughly and inspect all tables and figures in a manuscript.

Forensic genetic analyses in isolated populations with examples of central European Valachs and Roma.

PubMed

Ehler, Edvard; Vanek, Daniel

2017-05-01

Isolated populations present a constant threat to the correctness of forensic genetic casework. In this review article we present several examples of how analyzing samples from isolated populations can bias the results of the forensic statistics and analyses. We select our examples from isolated populations from central and southeastern Europe, namely the Valachs and the European Roma. We also provide the reader with general strategies and principles to improve the laboratory practice (best practice) and reporting of samples from supposedly isolated populations. These include reporting the precise population data used for computing the forensic statistics, using the appropriate θ correction factor for calculating allele frequencies, typing ancestry informative markers in samples of unknown or uncertain ethnicity and establishing ethnic-specific forensic databases. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Inadvertent P-hacking among trials and systematic reviews of the effect of progestogens in pregnancy? A systematic review and meta-analysis.

PubMed

Prior, M; Hibberd, R; Asemota, N; Thornton, J G

2017-06-01

Progestogens have been evaluated in numerous trials and meta-analyses, many of which concluded they were effective. However, two large trials PROMISE and OPPTIMUM have recently concluded that progesterone was ineffective. This raises the possibility that earlier studies and reviews had been biased by either selective publication or selective choice of outcomes, so called "P-hacking". To compare the findings all progestogen trials and systematic reviews with those of trials with pre-registered primary outcomes which avoided selective outcome reporting. Search of PubMed, the Cochrane Library and trial registries. Registration PROSPERO CRD42016035303. Systematic reviews of randomised trials comparing progestogen with placebo in pregnancy and the individual trials included in those reviews. The subset of trials reporting a pre-registered primary outcome were compared with the totality of trials and reviews. For reviews all outcomes were included. For individual trials all outcomes reported in the systematic reviews were included. For the comparison group we recorded the registered primary outcome from trials that were either registered before they started, or registered during the recruitment phase and also double blind. Nineteen of twenty-nine meta-analyses concluded that progestogens were effective. Twenty-two trials reported their pre-registered primary outcomes. There was no effect of progesterone on primary registered dichotomous outcome RR 1.00 (95% CI 0.94-1.07). Only one of the 22 showed a nominally statistically significant benefit. When evaluated in registered double-blind trials with analysis restricted to predefined primary outcomes, progestational agents in pregnancy are ineffective. Progestogens to prevent pregnancy loss, an example of P-hacking. © 2017 Royal College of Obstetricians and Gynaecologists.

Clinical information modeling processes for semantic interoperability of electronic health records: systematic review and inductive analysis.

PubMed

Moreno-Conde, Alberto; Moner, David; Cruz, Wellington Dimas da; Santos, Marcelo R; Maldonado, José Alberto; Robles, Montserrat; Kalra, Dipak

2015-07-01

This systematic review aims to identify and compare the existing processes and methodologies that have been published in the literature for defining clinical information models (CIMs) that support the semantic interoperability of electronic health record (EHR) systems. Following the preferred reporting items for systematic reviews and meta-analyses systematic review methodology, the authors reviewed published papers between 2000 and 2013 that covered that semantic interoperability of EHRs, found by searching the PubMed, IEEE Xplore, and ScienceDirect databases. Additionally, after selection of a final group of articles, an inductive content analysis was done to summarize the steps and methodologies followed in order to build CIMs described in those articles. Three hundred and seventy-eight articles were screened and thirty six were selected for full review. The articles selected for full review were analyzed to extract relevant information for the analysis and characterized according to the steps the authors had followed for clinical information modeling. Most of the reviewed papers lack a detailed description of the modeling methodologies used to create CIMs. A representative example is the lack of description related to the definition of terminology bindings and the publication of the generated models. However, this systematic review confirms that most clinical information modeling activities follow very similar steps for the definition of CIMs. Having a robust and shared methodology could improve their correctness, reliability, and quality. Independently of implementation technologies and standards, it is possible to find common patterns in methods for developing CIMs, suggesting the viability of defining a unified good practice methodology to be used by any clinical information modeler. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Androgen deprivation treatment of sexual behavior.

PubMed

Houts, Frederick W; Taller, Inna; Tucker, Douglas E; Berlin, Fred S

2011-01-01

Gonadotropin-releasing hormone agonists are underutilized in patients seeking diminution of problematic sexual drives. This chapter reviews the literature on surgical castration of sex offenders, anti-androgen use and the rationale for providing androgen deprivation therapy, rather than selective serotonin reuptake inhibitors or more conservative interventions, for patients with paraphilias and excessive sexual drive. Discussions of informed consent, side effects, contraindications and case examples are provided. Copyright © 2011 S. Karger AG, Basel.

The Intersection of Structural and Chemical Biology - An Essential Synergy.

PubMed

Zuercher, William J; Elkins, Jonathan M; Knapp, Stefan

2016-01-21

The continual improvement in our ability to generate high resolution structural models of biological molecules has stimulated and supported innovative chemical biology projects that target increasingly challenging ligand interaction sites. In this review we outline some of the recent developments in chemical biology and rational ligand design and show selected examples that illustrate the synergy between these research areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Examination of Real Property Tax Exemptions: An Example of Land Use Planning for Fiscal Gain. Exchange Bibliography No. 172.

ERIC Educational Resources Information Center

Martin, Larry R. G.

This selected bibliography focuses on property tax exemptions in urban areas and on the ability of cities to generate property tax revenues. It begins with a review of some relationships between the property tax and land use planning. Then, the role of the property tax as one of several devices employed in fiscally-oriented planning is examined.…

Supercritical Fluid Extraction of Metal Chelate: A Review.

PubMed

Ding, Xin; Liu, Qinli; Hou, Xiongpo; Fang, Tao

2017-03-04

Supercritical fluid extraction (SFE), as a new green extraction technology, has been used in extracting various metal species. The solubilities of chelating agents and corresponding metal chelates are the key factors which influence the efficiency of SFE. Other main properties of them such as stability and selectivity are also reviewed. The extraction mechanisms of mainly used chelating agents are explained by typical examples in this paper. This is the important aspect of SFE of metal ions. Moreover, the extraction efficiencies of metal species also depend on other factors such as temperature, pressure, extraction time and matrix effect. The two main complexation methods namely in-situ and on-line chelating SFE are described in detail. As an efficient chelating agent, tributyl phosphate-nitric acid (TBP-HNO 3 ) complex attracts much attention. The SFE of metal ions, lanthanides and actinides as well as organometallic compounds are also summarized. With the proper selection of ligands, high efficient extraction of metal species can be obtained. As an efficient sample analysis method, supercritical fluid chromatography (SFC) is introduced in this paper. Recently, the extraction method combining ionic liquids (ILs) with supercritical fluid has been becoming a novel technology for treating metal ions. The kinetics related to SFE of metal species is discussed with some specific examples.

Analysis of Local Structure, Chemistry and Bonding by Electron Energy Loss Spectroscopy

NASA Astrophysics Data System (ADS)

Mayer, Joachim

In the present chapter, the reader will first be introduced briefly to the basic principles of analytical transmission electron microscopy (ATEM) with special emphasis on electron energy-loss spectroscopy (EELS) and energy-filtering TEM. The quantification of spectra to obtain chemical information and the origin and interpretation of near-edge fine structures in EELS (ELNES) are discussed. Special attention will be given to the characterization of internal interfaces and the literature in this area will be reviewed. Selected examples of the application of ATEM in the investigation of internal interfaces will be given. These examples include both EELS in the energy-filtering TEM and in the scanning transmission electron microscope (STEM).

Review of Portable and Low-Cost Sensors for the Ambient Air Monitoring of Benzene and Other Volatile Organic Compounds

PubMed Central

Kok, Gertjan; Persijn, Stefan; Sauerwald, Tilman

2017-01-01

This article presents a literature review of sensors for the monitoring of benzene in ambient air and other volatile organic compounds. Combined with information provided by stakeholders, manufacturers and literature, the review considers commercially available sensors, including PID-based sensors, semiconductor (resistive gas sensors) and portable on-line measuring devices as for example sensor arrays. The bibliographic collection includes the following topics: sensor description, field of application at fixed sites, indoor and ambient air monitoring, range of concentration levels and limit of detection in air, model descriptions of the phenomena involved in the sensor detection process, gaseous interference selectivity of sensors in complex VOC matrix, validation data in lab experiments and under field conditions. PMID:28657595

Review of Portable and Low-Cost Sensors for the Ambient Air Monitoring of Benzene and Other Volatile Organic Compounds.

PubMed

Spinelle, Laurent; Gerboles, Michel; Kok, Gertjan; Persijn, Stefan; Sauerwald, Tilman

2017-06-28

This article presents a literature review of sensors for the monitoring of benzene in ambient air and other volatile organic compounds. Combined with information provided by stakeholders, manufacturers and literature, the review considers commercially available sensors, including PID-based sensors, semiconductor (resistive gas sensors) and portable on-line measuring devices as for example sensor arrays. The bibliographic collection includes the following topics: sensor description, field of application at fixed sites, indoor and ambient air monitoring, range of concentration levels and limit of detection in air, model descriptions of the phenomena involved in the sensor detection process, gaseous interference selectivity of sensors in complex VOC matrix, validation data in lab experiments and under field conditions.

Flow chemistry vs. flow analysis.

PubMed

Trojanowicz, Marek

2016-01-01

The flow mode of conducting chemical syntheses facilitates chemical processes through the use of on-line analytical monitoring of occurring reactions, the application of solid-supported reagents to minimize downstream processing and computerized control systems to perform multi-step sequences. They are exactly the same attributes as those of flow analysis, which has solid place in modern analytical chemistry in several last decades. The following review paper, based on 131 references to original papers as well as pre-selected reviews, presents basic aspects, selected instrumental achievements and developmental directions of a rapidly growing field of continuous flow chemical synthesis. Interestingly, many of them might be potentially employed in the development of new methods in flow analysis too. In this paper, examples of application of flow analytical measurements for on-line monitoring of flow syntheses have been indicated and perspectives for a wider application of real-time analytical measurements have been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

A review of active learning approaches to experimental design for uncovering biological networks

PubMed Central

2017-01-01

Various types of biological knowledge describe networks of interactions among elementary entities. For example, transcriptional regulatory networks consist of interactions among proteins and genes. Current knowledge about the exact structure of such networks is highly incomplete, and laboratory experiments that manipulate the entities involved are conducted to test hypotheses about these networks. In recent years, various automated approaches to experiment selection have been proposed. Many of these approaches can be characterized as active machine learning algorithms. Active learning is an iterative process in which a model is learned from data, hypotheses are generated from the model to propose informative experiments, and the experiments yield new data that is used to update the model. This review describes the various models, experiment selection strategies, validation techniques, and successful applications described in the literature; highlights common themes and notable distinctions among methods; and identifies likely directions of future research and open problems in the area. PMID:28570593

Emerging interpretations of quantum mechanics and recent progress in quantum measurement

NASA Astrophysics Data System (ADS)

Clarke, M. L.

2014-01-01

The focus of this paper is to provide a brief discussion on the quantum measurement process, by reviewing select examples highlighting recent progress towards its understanding. The areas explored include an outline of the measurement problem, the standard interpretation of quantum mechanics, quantum to classical transition, types of measurement (including weak and projective measurements) and newly emerging interpretations of quantum mechanics (decoherence theory, objective reality, quantum Darwinism and quantum Bayesianism).

Drug discovery strategies to outer membrane targets in Gram-negative pathogens.

PubMed

Brown, Dean G

2016-12-15

This review will cover selected recent examples of drug discovery strategies which target the outer membrane (OM) of Gram-negative bacteria either by disruption of outer membrane function or by inhibition of essential gene products necessary for outer membrane assembly. Significant advances in pathway elucidation, structural biology and molecular inhibitor designs have created new opportunities for drug discovery within this target-class space. Copyright © 2016 Elsevier Ltd. All rights reserved.

Opportunistic Constructive Induction: Using Fragments of Domain Knowledge to Guide Construction

DTIC Science & Technology

1991-01-01

contribute to its success in ways which they are often unaware of and, unfortunately, which go by unacknowledged. At the risk of omitting some people I am...ference on Machine Learning, pages 322 -329, Austin, TX, June 1990. [Blumer e_1 al... 19871 Anselm Blurner, Andrzej Ehrenfeucht, David Haussler, and...and Ryszard S. Michalki. A Comparative Review of Selected Methods fur Learning from Examples. In- Machine Learning: An A rtificialIntelligence

Targeted Nanomaterials for Phototherapy

PubMed Central

Chitgupi, Upendra; Qin, Yiru; Lovell, Jonathan F.

2017-01-01

Phototherapies involve the irradiation of target tissues with light. To further enhance selectivity and potency, numerous molecularly targeted photosensitizers and photoactive nanoparticles have been developed. Active targeting typically involves harnessing the affinity between a ligand and a cell surface receptor for improved accumulation in the targeted tissue. Targeting ligands including peptides, proteins, aptamers and small molecules have been explored for phototherapy. In this review, recent examples of targeted nanomaterials used in phototherapy are summarized. PMID:29071178

Federal Source Selection Procedures in Competitive Negotiated Acquisitions.

DTIC Science & Technology

1982-05-01

together. A classic example of the range of that discretion can be found in a 1971 protest involving the National Aeronautics and Space Administration.1...than those proposed in technically inferior proposals. 52 Coup. Gen. 358 (1972)1 8-171696, July 20, 1971 ; 3-170633, May 3, 1971 . Similarly, on a...8, 1971 . Our review of the subject award, therefore, is limited to deciding whether the record reasonably supports a conclusion that the award was

Literature Review on Anti-Terrorism and Selected Bibliography on Terrorism.

DTIC Science & Technology

1988-04-01

quickly outdated because of the frequency with which new events must be listed, catalogued, and analyzed. For example, in the first months of this b...likely, the 4P terrorist group) attempts to make the target government appear unable to respond credibly to threats to the public security. Because pure...usually outdated by publication time. While a historical perspective can be gained from the chronologies of specific target groups and areas, such as

How geoarchaeology and landscape archaeology contribute to niche construction theory (NCT).

PubMed

Kluiving, Sjoerd J

In this paper a review is given of examples of geoarchaeological and landscape archaeological research from four locations throughout Europe. Case-studies from the North Sea coastal zone in the Netherlands and the Eastern Mediterranean are presented to illustrate the potential contribution of geoarchaeology and landscape archaeology to niche construction theory (NCT) studies. Typical landscapes as coast lines, lake shores and rivers as example of small and large scale use of the natural landscape and/or topography are discussed with implications for NCT, mainly over the Holocene period. Through environmental reconstruction, we provide relative dates for starting points when humans (a) were altering their own selective environment as an inceptive change, or (b) responded to a (deteriorated) selective environment in a counteractive change. Geoarchaeology and landscape archaeology valuable contribution to NCT studies is the focus of the disciplines on landscape gradients. NCT phase transitions from inceptive to counteractive changes are proposed as useful alternative in the debate about the onset of the Anthropocene.

Linear regression analysis: part 14 of a series on evaluation of scientific publications.

PubMed

Schneider, Astrid; Hommel, Gerhard; Blettner, Maria

2010-11-01

Regression analysis is an important statistical method for the analysis of medical data. It enables the identification and characterization of relationships among multiple factors. It also enables the identification of prognostically relevant risk factors and the calculation of risk scores for individual prognostication. This article is based on selected textbooks of statistics, a selective review of the literature, and our own experience. After a brief introduction of the uni- and multivariable regression models, illustrative examples are given to explain what the important considerations are before a regression analysis is performed, and how the results should be interpreted. The reader should then be able to judge whether the method has been used correctly and interpret the results appropriately. The performance and interpretation of linear regression analysis are subject to a variety of pitfalls, which are discussed here in detail. The reader is made aware of common errors of interpretation through practical examples. Both the opportunities for applying linear regression analysis and its limitations are presented.

Personalizing behavioral interventions: the case of late-life depression

PubMed Central

Arean, Patricia A

2013-01-01

SUMMARY This article reviews the potential utility of behavioral interventions in personalized depression treatment. The paper begins with a definition of personalized treatment, moves to current thinking regarding the various causes of depression, and proposes how those causes can be used to inform the selection of behavioral interventions. Two examples from the late-life depression field will illustrate how a team of researchers at Cornell University (NY, USA) and University of California, San Francisco (CA, USA) created a research partnership to select and study behavioral interventions for older adults with risk factors associated with poor response to selective serotonin reuptake inhibitor medications. The paper ends with a discussion of how the process used by the Cornell University–University of California, San Francisco team can be applied to the selection and development of behavioral interventions for other psychiatric disorders. PMID:23646065

In Vitro Reconstitution of Metabolic Pathways: Insights into Nature’s Chemical Logic

PubMed Central

Lowry, Brian; Walsh, Christopher T.

2015-01-01

In vitro analysis of metabolic pathways is becoming a powerful method to gain a deeper understanding of Nature’s core biochemical transformations. With astounding advancements in biotechnology, purification of a metabolic pathway’s constitutive enzymatic components is becoming a tractable problem, and such in vitro studies allow scientists to capture the finer details of enzymatic reaction mechanisms, kinetics, and the identity of organic product molecules. In this review, we present eleven metabolic pathways that have been the subject of in vitro reconstitution studies in the literature in recent years. In addition, we have selected and analyzed subset of four case studies within these eleven examples that exemplify remarkable organic chemistry occurring within biology. These examples serves as tangible reminders that Nature’s biochemical routes obey the fundamental principles of organic chemistry, and the chemical mechanisms are reminiscent of those featured in traditional synthetic organic routes. The illustrations of biosynthetic chemistry depicted in this review may inspire the development of biomimetic chemistries via abiotic chemical techniques. PMID:26207083

Comparative Physiology of Fatigue.

PubMed

Jones, James H

2016-11-01

This review attempts to provide insights into factors associated with fatigue in human and nonhuman animals by using the two fundamental approaches of comparative physiology: determining common principles that govern structure and function in animals that are relatively invariant between animals and evaluating animals that have been highly adapted by natural selection to demonstrate extreme performance. In this review, I approach the topic of fatigue by considering factors that are associated with its reciprocal or inverse or duration of sustained performance before fatigue sets in to end the performance. The two general factors that I consider that affect endurance time more than any other are body temperature and body mass. The former affects endurance time because of thermodynamic effects on chemical reaction rates and metabolism; the latter acts through the mechanism of allometry or scaling. The examples of extreme animal performance that I discuss are two examples of bird migration, the diving performance of marine mammals, and the unique relationship that governs energy cost of locomotion in hopping kangaroos.

Linking sensory biology and fisheries bycatch reduction in elasmobranch fishes: a review with new directions for research

PubMed Central

Jordan, Laura K.; Mandelman, John W.; McComb, D. Michelle; Fordham, Sonja V.; Carlson, John K.; Werner, Timothy B.

2013-01-01

Incidental capture, or bycatch, in fisheries represents a substantial threat to the sustainability of elasmobranch populations worldwide. Consequently, researchers are increasingly investigating elasmobranch bycatch reduction methods, including some focused on these species' sensory capabilities, particularly their electrosensory systems. To guide this research, we review current knowledge of elasmobranch sensory biology and feeding ecology with respect to fishing gear interactions and include examples of bycatch reduction methods used for elasmobranchs as well as other taxonomic groups. We discuss potential elasmobranch bycatch reduction strategies for various fishing gear types based on the morphological, physiological, and behavioural characteristics of species within this diverse group. In select examples, we indicate how an understanding of the physiology and sensory biology of vulnerable, bycatch-prone, non-target elasmobranch species can help in the identification of promising options for bycatch reduction. We encourage collaboration among researchers studying bycatch reduction across taxa to provide better understanding of the broad effects of bycatch reduction methods. PMID:27293586

Application of Machine Learning Approaches for Protein-protein Interactions Prediction.

PubMed

Zhang, Mengying; Su, Qiang; Lu, Yi; Zhao, Manman; Niu, Bing

2017-01-01

Proteomics endeavors to study the structures, functions and interactions of proteins. Information of the protein-protein interactions (PPIs) helps to improve our knowledge of the functions and the 3D structures of proteins. Thus determining the PPIs is essential for the study of the proteomics. In this review, in order to study the application of machine learning in predicting PPI, some machine learning approaches such as support vector machine (SVM), artificial neural networks (ANNs) and random forest (RF) were selected, and the examples of its applications in PPIs were listed. SVM and RF are two commonly used methods. Nowadays, more researchers predict PPIs by combining more than two methods. This review presents the application of machine learning approaches in predicting PPI. Many examples of success in identification and prediction in the area of PPI prediction have been discussed, and the PPIs research is still in progress. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A comparative review of cutaneous pH.

PubMed

Matousek, Jennifer L; Campbell, Karen L

2002-12-01

This review describes the role of pH in cutaneous structure and function. We first describe the molecules that contribute to the acidity or alkalinity of the skin. Next, differences in cutaneous pH among species, among individuals of the same species and within individuals are described. The potential functions of cutaneous pH in normal and diseased skin are analysed. For example, cutaneous pH has a role in the selection and maintenance of the normal cutaneous microbiota. In addition, cutaneous acidity may protect the skin against infection by microbes. Finally, there is evidence that a cutaneous pH gradient activates pH-dependent enzymes involved in the process of keratinization.

Air-to-air combat analysis - Review of differential-gaming approaches

NASA Technical Reports Server (NTRS)

Ardema, M. D.

1981-01-01

The problem of evaluating the combat performance of fighter/attack aircraft is discussed, and the mathematical nature of the problem is examined. The following approaches to air combat analysis are reviewed: (1) differential-turning differential game and (2) coplanar differential game. Selected numerical examples of these approaches are presented. The relative advantages and disadvantages of each are analyzed, and it is concluded that air combat analysis is an extremely difficult mathematical problem and that no one method of approach is best for all purposes. The paper concludes with a discussion of how the two approaches might be used in a complementary manner.

Essential and Nonessential Micronutrients and Sport

NASA Astrophysics Data System (ADS)

Beavers, Kristen M.; Serra, Monica C.

The purpose of this chapter is to review the role of micronutrients in sport. Attention is given to the function of micronutrients in the body, examples of quality dietary sources of each micronutrient, and an assessment of the literature examining how the recommended daily intake of a micronutrient may or may not change with exercise. The discussion includes plausible biological mechanisms of proposed performance enhancement and current research to support or negate these claims. Water-soluble vitamins, fat-soluble vitamins, macrominerals, and select microminerals are discussed in detail, and a comprehensive table reviewing all micronutrients recommendations for the athlete is provided. Practical applications for professionals working with athletes conclude the chapter.

Dish systems for CSP

DOE PAGES

Coventry, Joe; Andraka, Charles

2017-03-22

Parabolic dish technology, for concentrating solar power (CSP) applications, has been continuously modified and improved since the pioneering work in the 1970s. Best practice dishes now have features such as lightweight structure, balanced design, high-quality, low-cost mirror panels, and can be deployed rapidly with little in-field labour. This review focuses on the evolution of dish design, by examining features such as mode of tracking, structure and mirror design, for a wide selection of CSP dish examples. Finally, the review includes a brief summary of power generation options – both on-dish and central plant – as well as a discussion aboutmore » options for storage and hybridisation.« less

Topological surface states in nodal superconductors.

PubMed

Schnyder, Andreas P; Brydon, Philip M R

2015-06-24

Topological superconductors have become a subject of intense research due to their potential use for technical applications in device fabrication and quantum information. Besides fully gapped superconductors, unconventional superconductors with point or line nodes in their order parameter can also exhibit nontrivial topological characteristics. This article reviews recent progress in the theoretical understanding of nodal topological superconductors, with a focus on Weyl and noncentrosymmetric superconductors and their protected surface states. Using selected examples, we review the bulk topological properties of these systems, study different types of topological surface states, and examine their unusual properties. Furthermore, we survey some candidate materials for topological superconductivity and discuss different experimental signatures of topological surface states.

Participatory Arts for Older Adults: A Review of Benefits and Challenges

PubMed Central

Noice, Tony; Noice, Helga; Kramer, Arthur F.

2014-01-01

This article reviews the scientific literature on the enhancement of healthy aging in older adults through active participation in the arts. Methodologies and conclusions are described for studies of dance, expressive writing, music (singing and instrumental), theatre arts, and visual arts including documentation of mental/physical improvements in memory, creativity, problem solving, everyday competence, reaction time, balance/gait, and quality of life. In addition to these gains in measures of successful aging, the article also provides (in a Supplementary Appendix) some selected examples of arts engagement for remedial purposes. Finally, it offers suggestions for expanding inquiry into this underinvestigated corner of aging research. PMID:24336875

Research on dental implant and its industrialization stage

NASA Astrophysics Data System (ADS)

Dongjoon, Yang; Sukyoung, Kim

2017-02-01

Bone cell attachment to Ti implant surfaces is the most concerned issue in the clinical implant dentistry. Many attempts to achieve the fast and strong integration between bone and implant have been tried in many ways, such as selection of materials (for example, Ti, ZrO2), shape design of implant (for example, soft tissue level, bone level, taped or conical, etc), and surface modification of implants (for example, roughed. coated, hybrid), etc. Among them, a major consideration is the surface design of dental implants. The surface with proper structural characteristics promotes or induces the desirable responses of cells and tissues. To obtain such surface which has desirable cell and tissue response, a variety of surface modification techniques has been developed and employed for many years. In this review, the method and trend of surface modification will be introduced and explained in terms of the surface topography and chemistry of dental implants.

Quality of systematic reviews: an example of studies comparing artificial disc replacement with fusion in the cervical spine.

PubMed

Tashani, Osama A; El-Tumi, Hanan; Aneiba, Khaled

2015-01-01

Cervical artificial disc replacement (C-ADR) is now an alternative to anterior cervical discectomy and fusion (ACDF). Many studies have evaluated the efficacy of C-ADR compared with ACDF. This led to a series of systematic reviews and meta-analyses to evaluate the evidence of the superiority of one intervention against the other. The aim of the study presented here was to evaluate the quality of these reviews and meta-analyses. Medline via Ovid, Embase, and Cochrane Library were searched using the keywords: (total disk replacement, prosthesis, implantation, discectomy, and arthroplasty) AND (cervical vertebrae, cervical spine, and spine) AND (systematic reviews, reviews, and meta-analysis). Screening and data extraction were conducted by two reviewers independently. Two reviewers then assessed the quality of the selected reviews and meta-analysis using 11-item AMSTAR score which is a validated measurement tool to assess the methodological quality of systematic reviews. Screening of full reports of 46 relevant abstracts resulted in the selection of 15 systematic reviews and/or meta-analyses as eligible for this study. The two reviewers' inter-rater agreement level was high as indicated by kappa of >0.72. The AMSTAR score of the reviews ranged from 3 to 11. Only one study (a Cochrane review) scored 100% (AMSTAR 11). Five studies scored below (AMSTAR 5) indicating low-quality reviews. The most significant drawbacks of reviews of a score below 5 were not using an extensive search strategy, failure to use the scientific quality of the included studies appropriately in formulating a conclusion, not assessing publication bias, and not reporting the excluded studies. With a significant exception of a Cochrane review, the methodological quality of systematic reviews evaluating the evidence of C-ADR versus ACDF has to be improved.

Endoscopic endonasal approaches for the management of skull base meningiomas. Selection criteria and clinical outcomes.

PubMed

Todeschini, Alexandre B; Otto, Bradley A; Carrau, Ricardo L; Prevedello, Daniel M

2018-05-28

Meningiomas are the most common primary intracranial tumor, arising from different locations, including the skull base. Despite advances in adjuvant treatments, surgical resection remains the main and best treatment for meningiomas. New surgical strategies, such as the endoscopic endonasal approach, have greatly contributed in achieving maximum and total safe resection, preserving the patient's neurological function. Based on the senior authors large experience and a review of the current literature, we have compiled this chapter. We review the surgical technique used at our institution and the most relevant aspects of patient selection when considering resecting a skull base meningioma using the the EEA. Further consideration is given to some skull base meningiomas arising from specific locations with some case examples. The EEA is not an ideal approach for every skull base meningioma. Careful evaluation of the surrounding neurovascular structures surrounding the tumor is imperative to select the appropriate surgical corridor for a safe resection. Nevertheless, for appropriately selected cases, the endoscopic technique is a very valuable tool with some evidences of being superior to the microscopic transcranial approach. A dual-trained surgeon, in both endoscopic and transcranial approaches, is the best alternative to achieve the best patient outcome.

Evidence-based guidelines for use of probiotics in preterm neonates.

PubMed

Deshpande, Girish C; Rao, Shripada C; Keil, Anthony D; Patole, Sanjay K

2011-08-02

Current evidence indicates that probiotic supplementation significantly reduces all-cause mortality and definite necrotising enterocolitis without significant adverse effects in preterm neonates. As the debate about the pros and cons of routine probiotic supplementation continues, many institutions are satisfied with the current evidence and wish to use probiotics routinely. Because of the lack of detail on many practical aspects of probiotic supplementation, clinician-friendly guidelines are urgently needed to optimise use of probiotics in preterm neonates. To develop evidence-based guidelines for probiotic supplementation in preterm neonates. To develop core guidelines on use of probiotics, including strain selection, dose and duration of supplementation, we primarily used the data from our recent updated systematic review of randomised controlled trials. For equally important issues including strain identification, monitoring for adverse effects, product format, storage and transport, and regulatory hurdles, a comprehensive literature search, covering the period 1966-2010 without restriction on the study design, was conducted, using the databases PubMed and EMBASE, and the proceedings of scientific conferences; these data were used in our updated systematic review. In this review, we present guidelines, including level of evidence, for the practical aspects (for example, strain selection, dose, duration, clinical and laboratory surveillance) of probiotic supplementation, and for dealing with non-clinical but important issues (for example, regulatory requirements, product format). Evidence was inadequate in some areas, and these should be a target for further research. We hope that these evidence-based guidelines will help to optimise the use of probiotics in preterm neonates. Continued research is essential to provide answers to the current gaps in knowledge about probiotics.

The prospects of selection for social genetic effects to improve welfare and productivity in livestock

PubMed Central

Ellen, Esther D.; Rodenburg, T. Bas; Albers, Gerard A. A.; Bolhuis, J. Elizabeth; Camerlink, Irene; Duijvesteijn, Naomi; Knol, Egbert F.; Muir, William M.; Peeters, Katrijn; Reimert, Inonge; Sell-Kubiak, Ewa; van Arendonk, Johan A. M.; Visscher, Jeroen; Bijma, Piter

2014-01-01

Social interactions between individuals living in a group can have both positive and negative effects on welfare, productivity, and health of these individuals. Negative effects of social interactions in livestock are easier to observe than positive effects. For example, laying hens may develop feather pecking, which can cause mortality due to cannibalism, and pigs may develop tail biting or excessive aggression. Several studies have shown that social interactions affect the genetic variation in a trait. Genetic improvement of socially-affected traits, however, has proven to be difficult until relatively recently. The use of classical selection methods, like individual selection, may result in selection responses opposite to expected, because these methods neglect the effect of an individual on its group mates (social genetic effects). It has become clear that improvement of socially-affected traits requires selection methods that take into account not only the direct effect of an individual on its own phenotype but also the social genetic effects, also known as indirect genetic effects, of an individual on the phenotypes of its group mates. Here, we review the theoretical and empirical work on social genetic effects, with a focus on livestock. First, we present the theory of social genetic effects. Subsequently, we evaluate the evidence for social genetic effects in livestock and other species, by reviewing estimates of genetic parameters for direct and social genetic effects. Then we describe the results of different selection experiments. Finally, we discuss issues concerning the implementation of social genetic effects in livestock breeding programs. This review demonstrates that selection for socially-affected traits, using methods that target both the direct and social genetic effects, is a promising, but sometimes difficult to use in practice, tool to simultaneously improve production and welfare in livestock. PMID:25426136

The prospects of selection for social genetic effects to improve welfare and productivity in livestock.

PubMed

Ellen, Esther D; Rodenburg, T Bas; Albers, Gerard A A; Bolhuis, J Elizabeth; Camerlink, Irene; Duijvesteijn, Naomi; Knol, Egbert F; Muir, William M; Peeters, Katrijn; Reimert, Inonge; Sell-Kubiak, Ewa; van Arendonk, Johan A M; Visscher, Jeroen; Bijma, Piter

2014-01-01

Social interactions between individuals living in a group can have both positive and negative effects on welfare, productivity, and health of these individuals. Negative effects of social interactions in livestock are easier to observe than positive effects. For example, laying hens may develop feather pecking, which can cause mortality due to cannibalism, and pigs may develop tail biting or excessive aggression. Several studies have shown that social interactions affect the genetic variation in a trait. Genetic improvement of socially-affected traits, however, has proven to be difficult until relatively recently. The use of classical selection methods, like individual selection, may result in selection responses opposite to expected, because these methods neglect the effect of an individual on its group mates (social genetic effects). It has become clear that improvement of socially-affected traits requires selection methods that take into account not only the direct effect of an individual on its own phenotype but also the social genetic effects, also known as indirect genetic effects, of an individual on the phenotypes of its group mates. Here, we review the theoretical and empirical work on social genetic effects, with a focus on livestock. First, we present the theory of social genetic effects. Subsequently, we evaluate the evidence for social genetic effects in livestock and other species, by reviewing estimates of genetic parameters for direct and social genetic effects. Then we describe the results of different selection experiments. Finally, we discuss issues concerning the implementation of social genetic effects in livestock breeding programs. This review demonstrates that selection for socially-affected traits, using methods that target both the direct and social genetic effects, is a promising, but sometimes difficult to use in practice, tool to simultaneously improve production and welfare in livestock.

Electron-density descriptors as predictors in quantitative structure--activity/property relationships and drug design.

PubMed

Matta, Chérif F; Arabi, Alya A

2011-06-01

The use of electron density-based molecular descriptors in drug research, particularly in quantitative structure--activity relationships/quantitative structure--property relationships studies, is reviewed. The exposition starts by a discussion of molecular similarity and transferability in terms of the underlying electron density, which leads to a qualitative introduction to the quantum theory of atoms in molecules (QTAIM). The starting point of QTAIM is the topological analysis of the molecular electron-density distributions to extract atomic and bond properties that characterize every atom and bond in the molecule. These atomic and bond properties have considerable potential as bases for the construction of robust quantitative structure--activity/property relationships models as shown by selected examples in this review. QTAIM is applicable to the electron density calculated from quantum-chemical calculations and/or that obtained from ultra-high resolution x-ray diffraction experiments followed by nonspherical refinement. Atomic and bond properties are introduced followed by examples of application of each of these two families of descriptors. The review ends with a study whereby the molecular electrostatic potential, uniquely determined by the density, is used in conjunction with atomic properties to elucidate the reasons for the biological similarity of bioisosteres.

Optimality and stability of symmetric evolutionary games with applications in genetic selection.

PubMed

Huang, Yuanyuan; Hao, Yiping; Wang, Min; Zhou, Wen; Wu, Zhijun

2015-06-01

Symmetric evolutionary games, i.e., evolutionary games with symmetric fitness matrices, have important applications in population genetics, where they can be used to model for example the selection and evolution of the genotypes of a given population. In this paper, we review the theory for obtaining optimal and stable strategies for symmetric evolutionary games, and provide some new proofs and computational methods. In particular, we review the relationship between the symmetric evolutionary game and the generalized knapsack problem, and discuss the first and second order necessary and sufficient conditions that can be derived from this relationship for testing the optimality and stability of the strategies. Some of the conditions are given in different forms from those in previous work and can be verified more efficiently. We also derive more efficient computational methods for the evaluation of the conditions than conventional approaches. We demonstrate how these conditions can be applied to justifying the strategies and their stabilities for a special class of genetic selection games including some in the study of genetic disorders.

Solar-Powered Plasmon-Enhanced Heterogeneous Catalysis

NASA Astrophysics Data System (ADS)

Naldoni, Alberto; Riboni, Francesca; Guler, Urcan; Boltasseva, Alexandra; Shalaev, Vladimir M.; Kildishev, Alexander V.

2016-06-01

Photocatalysis uses semiconductors to convert sunlight into chemical energy. Recent reports have shown that plasmonic nanostructures can be used to extend semiconductor light absorption or to drive direct photocatalysis with visible light at their surface. In this review, we discuss the fundamental decay pathway of localized surface plasmons in the context of driving solar-powered chemical reactions. We also review different nanophotonic approaches demonstrated for increasing solar-to-hydrogen conversion in photoelectrochemical water splitting, including experimental observations of enhanced reaction selectivity for reactions occurring at the metalsemiconductor interface. The enhanced reaction selectivity is highly dependent on the morphology, electronic properties, and spatial arrangement of composite nanostructures and their elements. In addition, we report on the particular features of photocatalytic reactions evolving at plasmonic metal surfaces and discuss the possibility of manipulating the reaction selectivity through the activation of targeted molecular bonds. Finally, using solar-to-hydrogen conversion techniques as an example, we quantify the efficacy metrics achievable in plasmon-driven photoelectrochemical systems and highlight some of the new directions that could lead to the practical implementation of solar-powered plasmon-based catalytic devices.

Can Untargeted Metabolomics Be Utilized in Drug Discovery/Development?

PubMed

Caldwell, Gary W; Leo, Gregory C

2017-01-01

Untargeted metabolomics is a promising approach for reducing the significant attrition rate for discovering and developing drugs in the pharmaceutical industry. This review aims to highlight the practical decision-making value of untargeted metabolomics for the advancement of drug candidates in drug discovery/development including potentially identifying and validating novel therapeutic targets, creating alternative screening paradigms, facilitating the selection of specific and translational metabolite biomarkers, identifying metabolite signatures for the drug efficacy mechanism of action, and understanding potential drug-induced toxicity. The review provides an overview of the pharmaceutical process workflow to discover and develop new small molecule drugs followed by the metabolomics process workflow that is involved in conducting metabolomics studies. The pros and cons of the major components of the pharmaceutical and metabolomics workflows are reviewed and discussed. Finally, selected untargeted metabolomics literature examples, from primarily 2010 to 2016, are used to illustrate why, how, and where untargeted metabolomics can be integrated into the drug discovery/preclinical drug development process. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation.

PubMed

Shamseer, Larissa; Moher, David; Clarke, Mike; Ghersi, Davina; Liberati, Alessandro; Petticrew, Mark; Shekelle, Paul; Stewart, Lesley A

2015-01-02

Protocols of systematic reviews and meta-analyses allow for planning and documentation of review methods, act as a guard against arbitrary decision making during review conduct, enable readers to assess for the presence of selective reporting against completed reviews, and, when made publicly available, reduce duplication of efforts and potentially prompt collaboration. Evidence documenting the existence of selective reporting and excessive duplication of reviews on the same or similar topics is accumulating and many calls have been made in support of the documentation and public availability of review protocols. Several efforts have emerged in recent years to rectify these problems, including development of an international register for prospective reviews (PROSPERO) and launch of the first open access journal dedicated to the exclusive publication of systematic review products, including protocols (BioMed Central's Systematic Reviews). Furthering these efforts and building on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, an international group of experts has created a guideline to improve the transparency, accuracy, completeness, and frequency of documented systematic review and meta-analysis protocols--PRISMA-P (for protocols) 2015. The PRISMA-P checklist contains 17 items considered to be essential and minimum components of a systematic review or meta-analysis protocol.This PRISMA-P 2015 Explanation and Elaboration paper provides readers with a full understanding of and evidence about the necessity of each item as well as a model example from an existing published protocol. This paper should be read together with the PRISMA-P 2015 statement. Systematic review authors and assessors are strongly encouraged to make use of PRISMA-P when drafting and appraising review protocols. © BMJ Publishing Group Ltd 2014.

Sexual Selection and the differences between the sexes in Mandrills (Mandrillus sphinx).

PubMed

Setchell, Joanna M

2016-01-01

Sexual selection has become a major focus in evolutionary and behavioral ecology. It is also a popular research topic in primatology. I use studies of mandrills (Mandrillus sphinx), a classic example of extravagant armaments and ornaments in animals, to exemplify how a long-term, multidisciplinary approach that integrates field observations with laboratory methods can contribute to on-going theoretical debates in the field of sexual selection. I begin with a brief summary of the main concepts of sexual selection theory and the differences between the sexes. I then introduce mandrills and the study population and review mandrill life history, the ontogeny of sex differences, and maternal effects. Next, I focus on male-male competition and female choice, followed by the less well-studied questions of female-female competition and male choice. This review shows how different reproductive priorities lead to very different life histories and divergent adaptations in males and females. It demonstrates how broadening traditional perspectives on sexual selection beyond the ostentatious results of intense sexual selection on males leads to an understanding of more subtle and cryptic forms of competition and choice in both sexes and opens many productive avenues in the study of primate reproductive strategies. These include the potential for studies of postcopulatory selection, female intrasexual competition, and male choice. These studies of mandrills provide comparison and, I hope, inspiration for studies of both other polygynandrous species and species with mating systems less traditionally associated with sexual selection. © 2016 Wiley Periodicals, Inc.

Lost in Translation: The Unintended Consequences of Advance Directive Law on Clinical Care

PubMed Central

Castillo, Lesley S.; Williams, Brie A.; Hooper, Sarah M.; Sabatino, Charles P.; Weithorn, Lois A.; Sudore, Rebecca L.

2011-01-01

Background Advance directive law may compromise the clinical effectiveness of advance directives. Purpose To identify unintended legal consequences of advance directive law that may prevent patients from communicating end-of-life preferences. Data Sources Advance directive legal statutes for all 50 U.S. states and the District of Columbia and English-language searches of LexisNexis, Westlaw, and MEDLINE from 1966 to August 2010. Study Selection Two independent reviewers selected 51 advance directive statutes and 20 articles. Three independent legal reviewers selected 105 legal proceedings. Data Extraction Two reviewers independently assessed data sources and used critical content analysis to determine legal barriers to the clinical effectiveness of advance directives. Disagreements were resolved by consensus. Data Synthesis Legal and content-related barriers included poor readability (that is, laws in all states were written above a 12th-grade reading level), health care agent or surrogate restrictions (for example, 40 states did not include same-sex or domestic partners as default surrogates), and execution requirements needed to make forms legally valid (for example, 35 states did not allow oral advance directives, and 48 states required witness signatures, a notary public, or both). Vulnerable populations most likely to be affected by these barriers included patients with limited literacy, limited English proficiency, or both who cannot read or execute advance directives; same-sex or domestic partners who may be without legally valid and trusted surrogates; and unbefriended, institutionalized, or homeless patients who may be without witnesses and suitable surrogates. Limitation Only appellate-level legal cases were available, which may have excluded relevant cases. Conclusion Unintended negative consequences of advance directive legal restrictions may prevent all patients, and particularly vulnerable patients, from making and communicating their end-of-life wishes and having them honored. These restrictions have rendered advance directives less clinically useful. Recommendations include improving readability, allowing oral advance directives, and eliminating witness or notary requirements. Primary Funding Source U.S. Department of Veterans Affairs and the Pfizer Foundation. PMID:21242368

[Drug vectorization or how to modulate tissular and cellular distribution of biologically active compounds].

PubMed

Couvreur, P

2001-07-01

Drug vectorization has undergone considerable development over the last few years. This review focuses on the intravenous route of administration. Colloid formulations allow a modulation of drug tissue distribution. Using liposomes and nanoparticles with unmodified surfaces, drugs can be targeted to macrophages of the reticulum endothelium system. When the liposomes or nanoparticles are covered with hydrophilic or flexible polymers, the vascular phase can be favored in order, for example, to facilitate selective extravasation at a tumor site. Therapeutic applications of these systems are presented. The development of "intelligent" vectors capable of modulating intracellular distribution of an active compounds is an equally interesting approach, for example pH-sensitive liposomes or nanoparticles decorated with folic acid capable of targeting intracellular cytoplasm.

Hooked on α-d-galactosidases: from biomedicine to enzymatic synthesis.

PubMed

Bakunina, Irina Yu; Balabanova, Larissa A; Pennacchio, Angela; Trincone, Antonio

2016-01-01

α-d-Galactosidases (EC 3.2.1.22) are enzymes employed in a number of useful bio-based applications. We have depicted a comprehensive general survey of α-d-galactosidases from different origin with special emphasis on marine example(s). The structures of natural α-galactosyl containing compounds are described. In addition to 3D structures and mechanisms of action of α-d-galactosidases, different sources, natural function and genetic regulation are also covered. Finally, hydrolytic and synthetic exploitations as free or immobilized biocatalysts are reviewed. Interest in the synthetic aspects during the next years is anticipated for access to important small molecules by green technology with an emphasis on alternative selectivity of this class of enzymes from different sources.

The role of fracture mechanics in the design of fuel tanks in space vehicles

NASA Technical Reports Server (NTRS)

Denton, S. J.; Liu, C. K.

1976-01-01

With special reference to design of fuel tanks in space vehicles, the principles of fracture mechanics are reviewed. An approximate but extremely simple relationship is derived among the operating stress level, the length of crack, and the number of cycles of failure. Any one of the variables can be computed approximately from the knowledge of the other two, if the loading schedule (mission of the tank) is not greatly altered. Two sample examples illustrating the procedures of determining the allowable safe operating stress corresponding to a set of assumed loading schedule are included. The selection of sample examples is limited by the relatively meager available data on the candidate material for various stress ratios in the cycling.

A review of acetylene, ethylene and ethane molecular spectroscopy for planetary applications

NASA Technical Reports Server (NTRS)

Maguire, W. C.

1982-01-01

Spectroscopic work in acetylene, ethylene and ethane, are of particular interest since the Voyager IRIS observations of Jupiter. Acetylene and ethane but not ethylene were observed in the Jovian spectrum. Two fundamental bands of the observed gases are used to determine the spatial distribution of these hydrocarbons on Jupiter and to illuminate the photochemistry of these species. The 100 to 1000 cm region is discussed and selected examples of current laboratory work are given.

The Application of Selected Network Methods for Reliable and Safe Transport by Small Commercial Vehicles

NASA Astrophysics Data System (ADS)

Matuszak, Zbigniew; Bartosz, Michał; Barta, Dalibor

2016-09-01

In the article are characterized two network methods (critical path method - CPM and program evaluation and review technique - PERT). On the example of an international furniture company's product, it presented the exemplification of methods to transport cargos (furniture elements). Moreover, the study showed diagrams for transportation of cargos from individual components' producers to the final destination - the showroom. Calculations were based on the transportation of furniture elements via small commercial vehicles.

NMR crystallography: structure and properties of materials from solid-state nuclear magnetic resonance observables

PubMed Central

Bryce, David L.

2017-01-01

This topical review provides a brief overview of recent developments in NMR crystallography and related NMR approaches to studying the properties of molecular and ionic solids. Areas of complementarity with diffraction-based methods are underscored. These include the study of disordered systems, of dynamic systems, and other selected examples where NMR can provide unique insights. Highlights from the literature as well as recent work from my own group are discussed. PMID:28875022

The National Research Service Award: strategies for developing a successful proposal.

PubMed

Parker, Barbara; Steeves, Richard

2005-01-01

An important experience for doctoral students is developing and submitting an application for a National Research Service Award (NRSA) from the National Institutes of Health (NIH). This article provides an overview of the process of developing and submitting an NRSA proposal from the perspective of a sponsor of successful proposals as well as a member of the Scientific Review Section. Topics included are suggestions for writing and rewriting the proposal, developing a training plan specific to the proposal, selection of sponsors consultants and references, the review process, and revising and resubmitting a proposal. Tables give examples of (a) applicants identifying strengths and areas for growth, (b) activities to address areas for growth (c), and responses to a previous review. The intended audience is beginning doctoral students and novice sponsors.

Antiviral Lectins: Selective Inhibitors of Viral Entry

PubMed Central

Mitchell, Carter A.; Ramessar, Koreen; O’Keefe, Barry R.

2017-01-01

Many natural lectins have been reported to have antiviral activity. As some of these have been put forward as potential development candidates for preventing or treating viral infections, we have set out in this review to survey the literature on antiviral lectins. The review groups lectins by structural class and class of source organism we also detail their carbohydrate specificity and their reported antiviral activities. The review concludes with a brief discussion of several of the pertinent hurdles that heterologous proteins must clear to be useful clinical candidates and cites examples where such studies have been reported for antiviral lectins. Though the clearest path currently being followed is the use of antiviral lectins as anti-HIV microbicides via topical mucosal administration, some investigators have also found systemic efficacy against acute infections following subcutaneous administration. PMID:28322922

Computerized Clinical Decision Support: Contributions from 2015

PubMed Central

Bouaud, J.

2016-01-01

Summary Objective To summarize recent research and select the best papers published in 2015 in the field of computerized clinical decision support for the Decision Support section of the IMIA yearbook. Method A literature review was performed by searching two bibliographic databases for papers related to clinical decision support systems (CDSSs) and computerized provider order entry (CPOE) systems. The aim was to identify a list of candidate best papers from the retrieved papers that were then peer-reviewed by external reviewers. A consensus meeting between the two section editors and the IMIA editorial team was finally conducted to conclude in the best paper selection. Results Among the 974 retrieved papers, the entire review process resulted in the selection of four best papers. One paper reports on a CDSS routinely applied in pediatrics for more than 10 years, relying on adaptations of the Arden Syntax. Another paper assessed the acceptability and feasibility of an important CPOE evaluation tool in hospitals outside the US where it was developed. The third paper is a systematic, qualitative review, concerning usability flaws of medication-related alerting functions, providing an important evidence-based, methodological contribution in the domain of CDSS design and development in general. Lastly, the fourth paper describes a study quantifying the effect of a complex, continuous-care, guideline-based CDSS on the correctness and completeness of clinicians’ decisions. Conclusions While there are notable examples of routinely used decision support systems, this 2015 review on CDSSs and CPOE systems still shows that, despite methodological contributions, theoretical frameworks, and prototype developments, these technologies are not yet widely spread (at least with their full functionalities) in routine clinical practice. Further research, testing, evaluation, and training are still needed for these tools to be adopted in clinical practice and, ultimately, illustrate the benefits that they promise. PMID:27830247

Chiral reagents in glycosylation and modification of carbohydrates.

PubMed

Wang, Hao-Yuan; Blaszczyk, Stephanie A; Xiao, Guozhi; Tang, Weiping

2018-02-05

Carbohydrates play a significant role in numerous biological events, and the chemical synthesis of carbohydrates is vital for further studies to understand their various biological functions. Due to the structural complexity of carbohydrates, the stereoselective formation of glycosidic linkages and the site-selective modification of hydroxyl groups are very challenging and at the same time extremely important. In recent years, the rapid development of chiral reagents including both chiral auxiliaries and chiral catalysts has significantly improved the stereoselectivity for glycosylation reactions and the site-selectivity for the modification of carbohydrates. These new tools will greatly facilitate the efficient synthesis of oligosaccharides, polysaccharides, and glycoconjugates. In this tutorial review, we will summarize these advances and highlight the most recent examples.

Review of controlled fusion research using laser heating.

NASA Technical Reports Server (NTRS)

Hertzberg, A.

1973-01-01

Development of methods for generating high laser pulse energy has stimulated research leading to new ideas for practical controlled thermonuclear fusion machines. A review is presented of some important efforts in progress, and two different approaches have been selected as examples for discussion. One involves the concept of very short pulse lasers with power output tailored, in time, to obtain a nearly isentropic compression of a deuterium-tritium pellet to very high densities and temperatures. A second approach utilizing long wavelength, long pulse, efficient gas lasers to heat a column of plasma contained in a solenoidal field is also discussed. The working requirements of the laser and various magnetic field geometries of this approach are described.

Coherent X-ray imaging across length scales

NASA Astrophysics Data System (ADS)

Munro, P. R. T.

2017-04-01

Contemporary X-ray imaging techniques span a uniquely wide range of spatial resolutions, covering five orders of magnitude. The evolution of X-ray sources, from the earliest laboratory sources through to highly brilliant and coherent free-electron lasers, has been key to the development of these imaging techniques. This review surveys the predominant coherent X-ray imaging techniques with fields of view ranging from that of entire biological organs, down to that of biomolecules. We introduce the fundamental principles necessary to understand the image formation for each technique as well as briefly reviewing coherent X-ray source development. We present example images acquired using a selection of techniques, by leaders in the field.

Some composite bearing and seal materials for gas turbine applications: A review

NASA Technical Reports Server (NTRS)

Sliney, Harold E.

1989-01-01

A review is made of the selection and tribological testing of materials for high-temperature bearings and seals. The goal is to achieve good tribological properties over a wide range of temperatures because bearings and seals must be functional from low temperature start-up conditions on up to the maximum temperatures encountered during engine operation. Plasma sprayed composite coatings with favorable tribological properties from 25 to 900 C are discussed. The performance of these coatings in simple tribological bench tests is described. Examples are also given of their performance in high-speed sliding contact seals and as Stirling cylinder liner materials, and as back up lubricants for compliant foil gas bearings.

Sexual selection and allometry: a critical reappraisal of the evidence and ideas.

PubMed

Bonduriansky, Russell

2007-04-01

One of the most pervasive ideas in the sexual selection literature is the belief that sexually selected traits almost universally exhibit positive static allometries (i.e., within a sample of conspecific adults, larger individuals have disproportionally larger traits). In this review, I show that this idea is contradicted by empirical evidence and theory. Although positive allometry is a typical attribute of some sexual traits in certain groups, the preponderance of positively allometric sexual traits in the empirical literature apparently results from a sampling bias reflecting a fascination with unusually exaggerated (bizarre) traits. I review empirical examples from a broad range of taxa illustrating the diversity of allometric patterns exhibited by signal, weapon, clasping and genital traits, as well as nonsexual traits. This evidence suggests that positive allometry may be the exception rather than the rule in sexual traits, that directional sexual selection does not necessarily lead to the evolution of positive allometry and, conversely, that positive allometry is not necessarily a consequence of sexual selection, and that many sexual traits exhibit sex differences in allometric intercept rather than slope. Such diversity in the allometries of secondary sexual traits is to be expected, given that optimal allometry should reflect resource allocation trade-offs, and patterns of sexual and viability selection on both trait size and body size. An unbiased empirical assessment of the relation between sexual selection and allometry is an essential step towards an understanding of this diversity.

Methodological issues and recommendations for systematic reviews of prognostic studies: an example from cardiovascular disease.

PubMed

Dretzke, Janine; Ensor, Joie; Bayliss, Sue; Hodgkinson, James; Lordkipanidzé, Marie; Riley, Richard D; Fitzmaurice, David; Moore, David

2014-12-03

Prognostic factors are associated with the risk of future health outcomes in individuals with a particular health condition. The prognostic ability of such factors is increasingly being assessed in both primary research and systematic reviews. Systematic review methodology in this area is continuing to evolve, reflected in variable approaches to key methodological aspects. The aim of this article was to (i) explore and compare the methodology of systematic reviews of prognostic factors undertaken for the same clinical question, (ii) to discuss implications for review findings, and (iii) to present recommendations on what might be considered to be 'good practice' approaches. The sample was comprised of eight systematic reviews addressing the same clinical question, namely whether 'aspirin resistance' (a potential prognostic factor) has prognostic utility relative to future vascular events in patients on aspirin therapy for secondary prevention. A detailed comparison of methods around study identification, study selection, quality assessment, approaches to analysis, and reporting of findings was undertaken and the implications discussed. These were summarised into key considerations that may be transferable to future systematic reviews of prognostic factors. Across systematic reviews addressing the same clinical question, there were considerable differences in the numbers of studies identified and overlap between included studies, which could only partially be explained by different study eligibility criteria. Incomplete reporting and differences in terminology within primary studies hampered study identification and selection process across reviews. Quality assessment was highly variable and only one systematic review considered a checklist for studies of prognostic questions. There was inconsistency between reviews in approaches towards analysis, synthesis, addressing heterogeneity and reporting of results. Different methodological approaches may ultimately affect the findings and interpretation of systematic reviews of prognostic research, with implications for clinical decision-making.

Traditional anthropology and geographical information systems in the collaborative study of Cassava in Africa

NASA Technical Reports Server (NTRS)

Romanoff, Steven

1991-01-01

Cross-cultural, village-level, and farmer surveys have been used with a geographical information system to describe the distribution and relative importance of cassava (manioc, yuca, Manihot esculenta) in its cultural, economic, and ecological contexts. It presents examples of data management for mapping, sample selection, cross-tabulation of characteristics, combination of data types for indices and hypothesis testing. The methods used are reviewed, and some of the main conclusions of the study are presented.

Speed challenge: a case for hardware implementation in soft-computing

NASA Technical Reports Server (NTRS)

Daud, T.; Stoica, A.; Duong, T.; Keymeulen, D.; Zebulum, R.; Thomas, T.; Thakoor, A.

2000-01-01

For over a decade, JPL has been actively involved in soft computing research on theory, architecture, applications, and electronics hardware. The driving force in all our research activities, in addition to the potential enabling technology promise, has been creation of a niche that imparts orders of magnitude speed advantage by implementation in parallel processing hardware with algorithms made especially suitable for hardware implementation. We review our work on neural networks, fuzzy logic, and evolvable hardware with selected application examples requiring real time response capabilities.

The effects and consequences of selected club drugs.

PubMed

Freese, Thomas E; Miotto, Karen; Reback, Cathy J

2002-09-01

Ecstasy (MDMA), gamma-hydroxybutyrate (GHB), ketamine, and methamphetamine are 4 examples of club drugs that are increasing in popularity. Although the pharmacological classifications of these drugs vary, MDMA has structural similarities to both amphetamine and the hallucinogen mescaline. Ketamine and GHB are anesthetic agents and methamphetamine is a long-acting psychostimulant. Medical visits for club drug-related toxicity have sharply increased across the country. This article provides a brief review of the literature on club drugs. Copyright 2002 Elsevier Science Inc.

Special opportunities in helicopter aerodynamics

NASA Technical Reports Server (NTRS)

Mccroskey, W. J.

1983-01-01

Aerodynamic research relating to modern helicopters includes the study of three dimensional, unsteady, nonlinear flow fields. A selective review is made of some of the phenomenon that hamper the development of satisfactory engineering prediction techniques, but which provides a rich source of research opportunities: flow separations, compressibility effects, complex vortical wakes, and aerodynamic interference between components. Several examples of work in progress are given, including dynamic stall alleviation, the development of computational methods for transonic flow, rotor-wake predictions, and blade-vortex interactions.

Forty years of Clar's aromatic π-sextet rule

PubMed Central

Solà, Miquel

2013-01-01

In 1972 Erich Clar formulated his aromatic π-sextet rule that allows discussing qualitatively the aromatic character of benzenoid species. Now, 40 years later, Clar's aromatic π-sextet rule is still a source of inspiration for many chemists. This simple rule has been validated both experimentally and theoretically. In this review, we select some particular examples to highlight the achievement of Clar's aromatic π-sextet rule in many situations and we discuss two recent successful cases of its application. PMID:24790950

Chiral phosphoric acid catalysis: from numbers to insights.

PubMed

Maji, Rajat; Mallojjala, Sharath Chandra; Wheeler, Steven E

2018-02-19

Chiral phosphoric acids (CPAs) have emerged as powerful organocatalysts for asymmetric reactions, and applications of computational quantum chemistry have revealed important insights into the activity and selectivity of these catalysts. In this tutorial review, we provide an overview of computational tools at the disposal of computational organic chemists and demonstrate their application to a wide array of CPA catalysed reactions. Predictive models of the stereochemical outcome of these reactions are discussed along with specific examples of representative reactions and an outlook on remaining challenges in this area.

[Problem areas and examples of best practice in intersectoral medication treatment--a literature review].

PubMed

Mehrmann, Lena; Ollenschläger, Günter

2014-01-01

Transitions between the outpatient and inpatient sector are a critical phase in medication treatment. This article provides an overview of published problem areas and examples of best practice in the intersectoral medication treatment. Data with regard to related problem areas and examples of best practice was collected in August 2011 by a systematic literature research. The relevant literature was identified using the following databases and search engines: MEDLINE, The Cochrane Library, EMBASE, Google, and Google Scholar. Additionally, a hand search was done on the websites of SpringerLink and Thieme Connect. The initial search yielded a total of 4,409 records which were further selected in two screening steps and analysed according to their relevance. Of the remaining 63 records, 3 exclusively described problem areas, 11 of them examples of best practice, and 49 provided information on both problem areas and examples of best practice with regard to intersectoral medication treatment. Among other things, problem areas include varying legal regulations in inpatient and outpatient medication treatment, drug therapy interruptions after hospital discharge, or deficits in communication and continuity of care. Examples of best practice are projects, programmes, initiatives, recommendations, and points to consider with respect to medication reconciliation, pharmaceutical support, or transitions of care. Problem areas as well as examples of best practice are mainly focused on the transition from inpatient to outpatient care. Copyright © 2013. Published by Elsevier GmbH.

Evolution, appearance, and occupational success.

PubMed

Little, Anthony C; Roberts, Craig S

2012-01-01

Visual characteristics, including facial appearance, are thought to play an important role in a variety of judgments and decisions that have real occupational outcomes in many settings. Indeed, there is growing evidence suggesting that appearance influences hiring decisions and even election results. For example, attractive individuals are more likely to be hired, taller men earn more, and the facial appearance of candidates has been linked to real election outcomes. In this article, we review evidence linking physical appearance to occupational success and evaluate the hypothesis that appearance based biases are consistent with predictions based on evolutionary theories of coalition formation and leadership choice. We discuss why appearance based effects are so pervasive, addressing ideas about a "kernel of truth" in attributions and about coalitional psychology. We additionally highlight that appearance may be differently related to success at work according to the types of job or task involved. For example, leaders may be chosen because the characteristics they possess are seen as best suited to lead in particular situations. During a time of war, a dominant-appearing leader may inspire confidence and intimidate enemies while during peace-time, when negotiation and diplomacy are needed, interpersonal skills may outweigh the value of a dominant leader. In line with these ideas, masculine-faced leaders are favored in war-time scenarios while feminine-faced leaders are favored in peace-time scenarios. We suggest that such environment or task specific competencies may be prevalent during selection processes, whereby individuals whose appearance best matches perceived task competences are most likely selected, and propose the general term "task-congruent selection" to describe these effects. Overall, our review highlights how potentially adaptive biases could influence choices in the work place. With respect to certain biases, understanding their origin and current prevalence is important in order to potentially reduce discrimination in the work place.

Evidence-based guidelines for use of probiotics in preterm neonates

PubMed Central

2011-01-01

Background Current evidence indicates that probiotic supplementation significantly reduces all-cause mortality and definite necrotising enterocolitis without significant adverse effects in preterm neonates. As the debate about the pros and cons of routine probiotic supplementation continues, many institutions are satisfied with the current evidence and wish to use probiotics routinely. Because of the lack of detail on many practical aspects of probiotic supplementation, clinician-friendly guidelines are urgently needed to optimise use of probiotics in preterm neonates. Aim To develop evidence-based guidelines for probiotic supplementation in preterm neonates. Methods To develop core guidelines on use of probiotics, including strain selection, dose and duration of supplementation, we primarily used the data from our recent updated systematic review of randomised controlled trials. For equally important issues including strain identification, monitoring for adverse effects, product format, storage and transport, and regulatory hurdles, a comprehensive literature search, covering the period 1966-2010 without restriction on the study design, was conducted, using the databases PubMed and EMBASE, and the proceedings of scientific conferences; these data were used in our updated systematic review. Results In this review, we present guidelines, including level of evidence, for the practical aspects (for example, strain selection, dose, duration, clinical and laboratory surveillance) of probiotic supplementation, and for dealing with non-clinical but important issues (for example, regulatory requirements, product format). Evidence was inadequate in some areas, and these should be a target for further research. Conclusion We hope that these evidence-based guidelines will help to optimise the use of probiotics in preterm neonates. Continued research is essential to provide answers to the current gaps in knowledge about probiotics. PMID:21806843

Quantification provides a conceptual basis for convergent evolution.

PubMed

Speed, Michael P; Arbuckle, Kevin

2017-05-01

While much of evolutionary biology attempts to explain the processes of diversification, there is an important place for the study of phenotypic similarity across life forms. When similar phenotypes evolve independently in different lineages this is referred to as convergent evolution. Although long recognised, evolutionary convergence is receiving a resurgence of interest. This is in part because new genomic data sets allow detailed and tractable analysis of the genetic underpinnings of convergent phenotypes, and in part because of renewed recognition that convergence may reflect limitations in the diversification of life. In this review we propose that although convergent evolution itself does not require a new evolutionary framework, none the less there is room to generate a more systematic approach which will enable evaluation of the importance of convergent phenotypes in limiting the diversity of life's forms. We therefore propose that quantification of the frequency and strength of convergence, rather than simply identifying cases of convergence, should be considered central to its systematic comprehension. We provide a non-technical review of existing methods that could be used to measure evolutionary convergence, bringing together a wide range of methods. We then argue that quantification also requires clear specification of the level at which the phenotype is being considered, and argue that the most constrained examples of convergence show similarity both in function and in several layers of underlying form. Finally, we argue that the most important and impressive examples of convergence are those that pertain, in form and function, across a wide diversity of selective contexts as these persist in the likely presence of different selection pressures within the environment. © 2016 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.

Current state of ethics literature synthesis: a systematic review of reviews.

PubMed

Mertz, Marcel; Kahrass, Hannes; Strech, Daniel

2016-10-03

Modern standards for evidence-based decision making in clinical care and public health still rely solely on eminence-based input when it comes to normative ethical considerations. Manuals for clinical guideline development or health technology assessment (HTA) do not explain how to search, analyze, and synthesize relevant normative information in a systematic and transparent manner. In the scientific literature, however, systematic or semi-systematic reviews of ethics literature already exist, and scholarly debate on their opportunities and limitations has recently bloomed. A systematic review was performed of all existing systematic or semi-systematic reviews for normative ethics literature on medical topics. The study further assessed how these reviews report on their methods for search, selection, analysis, and synthesis of ethics literature. We identified 84 reviews published between 1997 and 2015 in 65 different journals and demonstrated an increasing publication rate for this type of review. While most reviews reported on different aspects of search and selection methods, reporting was much less explicit for aspects of analysis and synthesis methods: 31 % did not fulfill any criteria related to the reporting of analysis methods; for example, only 25 % of the reviews reported the ethical approach needed to analyze and synthesize normative information. While reviews of ethics literature are increasingly published, their reporting quality for analysis and synthesis of normative information should be improved. Guiding questions are: What was the applied ethical approach and technical procedure for identifying and extracting the relevant normative information units? What method and procedure was employed for synthesizing normative information? Experts and stakeholders from bioethics, HTA, guideline development, health care professionals, and patient organizations should work together to further develop this area of evidence-based health care.

Hydrothermal synthesis for new multifunctional materials: A few examples of phosphates and phosphonate-based hybrid materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rueff, Jean-Michel, E-mail: jean-michel.rueff@ensicaen.fr; Poienar, Maria; Guesdon, Anne

Novel physical or chemical properties are expected in a great variety of materials, in connection with the dimensionality of their structures and/or with their nanostructures, hierarchical superstructures etc. In the search of new advanced materials, the hydrothermal technique plays a crucial role, mimicking the nature able to produce fractal, hyperbranched, urchin-like or snow flake structures. In this short review including new results, this will be illustrated by examples selected in two types of materials, phosphates and phosphonates, prepared by this method. The importance of the synthesis parameters will be highlighted for a magnetic iron based phosphates and for hybrids containingmore » phosphonates organic building units crystallizing in different structural types. - Graphical abstract: Phosphate dendrite like and phosphonate platelet crystals.« less

Particle Radiation Sources, Propagation and Interactions in Deep Space, at Earth, the Moon, Mars, and Beyond: Examples of Radiation Interactions and Effects

NASA Astrophysics Data System (ADS)

Schwadron, Nathan A.; Cooper, John F.; Desai, Mihir; Downs, Cooper; Gorby, Matt; Jordan, Andrew P.; Joyce, Colin J.; Kozarev, Kamen; Linker, Jon A.; Mikíc, Zoran; Riley, Pete; Spence, Harlan E.; Török, Tibor; Townsend, Lawrence W.; Wilson, Jody K.; Zeitlin, Cary

2017-11-01

Particle radiation has significant effects for astronauts, satellites and planetary bodies throughout the Solar System. Acute space radiation hazards pose risks to human and robotic exploration. This radiation also naturally weathers the exposed surface regolith of the Moon, the two moons of Mars, and other airless bodies, and contributes to chemical evolution of planetary atmospheres at Earth, Mars, Venus, Titan, and Pluto. We provide a select review of recent areas of research covering the origin of SEPs from coronal mass ejections low in the corona, propagation of events through the solar system during the anomalously weak solar cycle 24 and important examples of radiation interactions for Earth, other planets and airless bodies such as the Moon.

Multilevel processes and cultural adaptation: Examples from past and present small-scale societies.

PubMed

Reyes-García, V; Balbo, A L; Gomez-Baggethun, E; Gueze, M; Mesoudi, A; Richerson, P; Rubio-Campillo, X; Ruiz-Mallén, I; Shennan, S

2016-12-01

Cultural adaptation has become central in the context of accelerated global change with authors increasingly acknowledging the importance of understanding multilevel processes that operate as adaptation takes place. We explore the importance of multilevel processes in explaining cultural adaptation by describing how processes leading to cultural (mis)adaptation are linked through a complex nested hierarchy, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviours. After a brief review of the concept of "cultural adaptation" from the perspective of cultural evolutionary theory and resilience theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social and political scales. We do so by examining small-scale societies' case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. We end the paper discussing the potential of modelling and computer simulation for studying multilevel processes in cultural adaptation.

Transcranial Magnetic Stimulation: Decomposing the Processes Underlying Action Preparation.

PubMed

Bestmann, Sven; Duque, Julie

2016-08-01

Preparing actions requires the operation of several cognitive control processes that influence the state of the motor system to ensure that the appropriate behavior is ultimately selected and executed. For example, some form of competition resolution ensures that the right action is chosen among alternatives, often in the presence of conflict; at the same time, impulse control ought to be deployed to prevent premature responses. Here we review how state-changes in the human motor system during action preparation can be studied through motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the contralateral primary motor cortex (M1). We discuss how the physiological fingerprints afforded by MEPs have helped to decompose some of the dynamic and effector-specific influences on the motor system during action preparation. We focus on competition resolution, conflict and impulse control, as well as on the influence of higher cognitive decision-related variables. The selected examples demonstrate the usefulness of MEPs as physiological readouts for decomposing the influence of distinct, but often overlapping, control processes on the human motor system during action preparation. © The Author(s) 2015.

Mechanistic Insight on the Activity and Substrate Selectivity of Nonheme Iron Dioxygenases.

PubMed

de Visser, Sam P

2018-06-07

Nonheme iron dioxygenases catalyze vital reactions for human health particularly related to aging processes. They are involved in the biosynthesis of amino acids, but also the biodegradation of toxic compounds. Typically they react with their substrate(s) through oxygen atom transfer, although often with the assistance of a co-substrate like α-ketoglutarate that is converted to succinate and CO 2 . Many reaction processes catalyzed by the nonheme iron dioxygenases are stereoselective or regiospecific and hence understanding the mechanism and protein involvement in the selectivity is important for the design of biotechnological applications of these enzymes. To this end, I will review recent work of our group on nonheme iron dioxygenases and include background information on their general structure and catalytic cycle. Examples of stereoselective and regiospecific reaction mechanisms we elucidated are for the AlkB repair enzyme, prolyl-4-hydroxylase and the ergothioneine biosynthesis enzyme. Finally, I cover an example where we bioengineered S-p-hydroxymandelate synthase into the R-p-hydroxymandelate synthase. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multilevel processes and cultural adaptation: Examples from past and present small-scale societies

PubMed Central

Reyes-García, V.; Balbo, A. L.; Gomez-Baggethun, E.; Gueze, M.; Mesoudi, A.; Richerson, P.; Rubio-Campillo, X.; Ruiz-Mallén, I.; Shennan, S.

2016-01-01

Cultural adaptation has become central in the context of accelerated global change with authors increasingly acknowledging the importance of understanding multilevel processes that operate as adaptation takes place. We explore the importance of multilevel processes in explaining cultural adaptation by describing how processes leading to cultural (mis)adaptation are linked through a complex nested hierarchy, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviours. After a brief review of the concept of “cultural adaptation” from the perspective of cultural evolutionary theory and resilience theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social and political scales. We do so by examining small-scale societies’ case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. We end the paper discussing the potential of modelling and computer simulation for studying multilevel processes in cultural adaptation. PMID:27774109

Transport mechanisms in nanopores and nanochannels: Can we mimic nature?

DOE PAGES

Tagliazucchi, Mario; Szleifer, Igal

2014-11-03

The last few years have witnessed major advancements in the synthesis, modification, characterization and modeling of nanometer-size solid-state channels and pores. Future applications in sensing, energy conversion and purification technologies will critically rely on qualitative improvements in the control over the selectivity, directionality and responsiveness of these nanochannels and nanopores. It is not surprising, therefore, that researchers in the field seek inspiration in biological ion channels and ion pumps, paradigmatic examples of transport selectivity. This work reviews our current fundamental understanding of the mechanisms of transport of ions and larger cargoes through nanopores and nanochannels by examining recent experimental andmore » theoretical work. It is argued that that structure and transport in biological channels and polyelectrolyte-modified synthetic nanopores are strongly coupled: the structure dictates transport and transport affects the structure. We compare synthetic and biological systems throughout this review to conclude that while they present interesting similarities, they also have striking differences.« less

Hormones and the blood-brain barrier.

PubMed

Hampl, Richard; Bičíková, Marie; Sosvorová, Lucie

2015-03-01

Hormones exert many actions in the brain, and brain cells are also hormonally active. To reach their targets in brain structures, hormones must overcome the blood-brain barrier (BBB). The BBB is a unique device selecting desired/undesired molecules to reach or leave the brain, and it is composed of endothelial cells forming the brain vasculature. These cells differ from other endothelial cells in their almost impermeable tight junctions and in possessing several membrane structures such as receptors, transporters, and metabolically active molecules, ensuring their selection function. The main ways how compounds pass through the BBB are briefly outlined in this review. The main part concerns the transport of major classes of hormones: steroids, including neurosteroids, thyroid hormones, insulin, and other peptide hormones regulating energy homeostasis, growth hormone, and also various cytokines. Peptide transporters mediating the saturable transport of individual classes of hormones are reviewed. The last paragraph provides examples of how hormones affect the permeability and function of the BBB either at the level of tight junctions or by various transporters.

Thinking outside the box - novel antibacterials to tackle the resistance crisis.

PubMed

Lakemeyer, Markus; Zhao, Weining; Mandl, Franziska A; Hammann, Peter; Sieber, Stephan Axel

2018-06-25

The public view on antibiotics as reliable medicine has changed when reports about "resistant superbugs" shattered the news. While reasons for this development are easily spotted, solutions for re-establishing effective antibiotics are still in their infancy. This review encompasses several aspects of the antibiotic development pipeline from very early strategies to mature drugs. We provide an interdisciplinary overview of methods suitable for mining novel antibiotics and discuss strategies to unravel their modes of action. Select examples of antibiotics recently identified using these platforms not only illustrate the efficiency of these measures, but also highlight promising clinical candidates with therapeutic potential. Furthermore, the concept of molecules that disarm pathogens by addressing gatekeepers of virulence will be covered. We conclude with an evaluation of antibacterials currently in clinical development. Overall, this review aims to connect select innovative antimicrobial approaches to stimulate interdisciplinary partnerships between chemists from academia and industry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanowire Chemical/Biological Sensors: Status and a Roadmap for the Future.

PubMed

Fennell, John F; Liu, Sophie F; Azzarelli, Joseph M; Weis, Jonathan G; Rochat, Sébastien; Mirica, Katherine A; Ravnsbæk, Jens B; Swager, Timothy M

2016-01-22

Chemiresistive sensors are becoming increasingly important as they offer an inexpensive option to conventional analytical instrumentation, they can be readily integrated into electronic devices, and they have low power requirements. Nanowires (NWs) are a major theme in chemosensor development. High surface area, interwire junctions, and restricted conduction pathways give intrinsically high sensitivity and new mechanisms to transduce the binding or action of analytes. This Review details the status of NW chemosensors with selected examples from the literature. We begin by proposing a principle for understanding electrical transport and transduction mechanisms in NW sensors. Next, we offer the reader a review of device performance parameters. Then, we consider the different NW types followed by a summary of NW assembly and different device platform architectures. Subsequently, we discuss NW functionalization strategies. Finally, we propose future developments in NW sensing to address selectivity, sensor drift, sensitivity, response analysis, and emerging applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rituals in nursing: intramuscular injections.

PubMed

Greenway, Kathleen

2014-12-01

To consider to what extent intramuscular injection technique can be described to remain entrenched in ritualistic practice and how evidence-based practice should be considered and applied to the nursing practice of this essential skill. The notion of rituals within nursing and the value or futile impact they afford to this essential nursing skill will be critically reviewed. Discursive paper. Literature review from 2002-2013 to review the current position of intramuscular injection injections. Within the literature review, it became clear that there are several actions within the administration of an intramuscular injection that could be perceived as ritualistic and require consideration for contemporary nursing practice. The essential nursing skill of intramuscular injection often appears to fit into the description of a ritualised practice. By providing evidence-based care, nurses will find themselves empowered to make informed decisions based on clinical need and using their clinical judgement. For key learning, it will outline with rationale how site selection, needle selection, insertion technique and aspiration can be cited as examples of routinised or ritualistic practice and why these should be rejected in favour of an evidence-based approach. The effect on some student nurses of experiencing differing practices between what is taught at university and what is often seen in clinical practice will also be discussed. © 2014 John Wiley & Sons Ltd.

Psy-feld: An Innovative Didactic Using the TV Show Seinfeld to Teach Delusional Disorder Subtypes.

PubMed

Tobia, Anthony; Bisen, Viwek; Zimmerman, Aphrodite; Trenton, Adam; Dix, Ebony; Dobkin, Roseanne

2015-08-01

The primary purpose of this article is to introduce Psy-feld, an innovative didactic used to review mental disorders through discussion of the interpersonal relationships of the fictional characters created in Larry David's situational comedy, Seinfeld. To introduce this novel didactic, several peripheral Seinfeld characters were selected, who while not afflicted with a psychotic disorder, demonstrate traits that serve to facilitate discussion to review the different subtypes of Delusional Disorder. Psy-feld is a 30-min faculty-facilitated didactic where a selected episode of the sitcom allows for review of multidisciplinary content areas considered germane to the practice of psychiatry. At Rutgers-Robert Wood Johnson Medical School, 104 third-year medical students rotated on the Consultation-Liaison Service from July 2011-March 2014 and participated in Psy-feld. Of the 104 students who participated in Psy-feld, 99 completed surveys on the didactic. Students found the didactic to be of high quality, believed it enhanced their learning, and thought that it prepared them for their final SHELF exam. Students also found it enjoyable and preferred the didactic to more traditional forms of teaching such as large group lectures. Psy-feld is an example of an innovative teaching method that medical students found informative in reviewing teaching points of Delusional Disorder.

A model-based correction for outcome reporting bias in meta-analysis.

PubMed

Copas, John; Dwan, Kerry; Kirkham, Jamie; Williamson, Paula

2014-04-01

It is often suspected (or known) that outcomes published in medical trials are selectively reported. A systematic review for a particular outcome of interest can only include studies where that outcome was reported and so may omit, for example, a study that has considered several outcome measures but only reports those giving significant results. Using the methodology of the Outcome Reporting Bias (ORB) in Trials study of (Kirkham and others, 2010. The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews. British Medical Journal 340, c365), we suggest a likelihood-based model for estimating the effect of ORB on confidence intervals and p-values in meta-analysis. Correcting for bias has the effect of moving estimated treatment effects toward the null and hence more cautious assessments of significance. The bias can be very substantial, sometimes sufficient to completely overturn previous claims of significance. We re-analyze two contrasting examples, and derive a simple fixed effects approximation that can be used to give an initial estimate of the effect of ORB in practice.

Review of SPECT collimator selection, optimization, and fabrication for clinical and preclinical imaging

PubMed Central

Van Audenhaege, Karen; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian; Metzler, Scott D.; Moore, Stephen C.

2015-01-01

In single photon emission computed tomography, the choice of the collimator has a major impact on the sensitivity and resolution of the system. Traditional parallel-hole and fan-beam collimators used in clinical practice, for example, have a relatively poor sensitivity and subcentimeter spatial resolution, while in small-animal imaging, pinhole collimators are used to obtain submillimeter resolution and multiple pinholes are often combined to increase sensitivity. This paper reviews methods for production, sensitivity maximization, and task-based optimization of collimation for both clinical and preclinical imaging applications. New opportunities for improved collimation are now arising primarily because of (i) new collimator-production techniques and (ii) detectors with improved intrinsic spatial resolution that have recently become available. These new technologies are expected to impact the design of collimators in the future. The authors also discuss concepts like septal penetration, high-resolution applications, multiplexing, sampling completeness, and adaptive systems, and the authors conclude with an example of an optimization study for a parallel-hole, fan-beam, cone-beam, and multiple-pinhole collimator for different applications. PMID:26233207

Targeting therapeutics to the glomerulus with nanoparticles.

PubMed

Zuckerman, Jonathan E; Davis, Mark E

2013-11-01

Nanoparticles are an enabling technology for the creation of tissue-/cell-specific therapeutics that have been investigated extensively as targeted therapeutics for cancer. The kidney, specifically the glomerulus, is another accessible site for nanoparticle delivery that has been relatively overlooked as a target organ. Given the medical need for the development of more potent, kidney-targeted therapies, the use of nanoparticle-based therapeutics may be one such solution to this problem. Here, we review the literature on nanoparticle targeting of the glomerulus. Specifically, we provide a broad overview of nanoparticle-based therapeutics and how the unique structural characteristics of the glomerulus allow for selective, nanoparticle targeting of this area of the kidney. We then summarize literature examples of nanoparticle delivery to the glomerulus and elaborate on the appropriate nanoparticle design criteria for glomerular targeting. Finally, we discuss the behavior of nanoparticles in animal models of diseased glomeruli and review examples of nanoparticle therapeutic approaches that have shown promise in animal models of glomerulonephritic disease. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Large Mammalian Animal Models of Heart Disease

PubMed Central

Camacho, Paula; Fan, Huimin; Liu, Zhongmin; He, Jia-Qiang

2016-01-01

Due to the biological complexity of the cardiovascular system, the animal model is an urgent pre-clinical need to advance our knowledge of cardiovascular disease and to explore new drugs to repair the damaged heart. Ideally, a model system should be inexpensive, easily manipulated, reproducible, a biological representative of human disease, and ethically sound. Although a larger animal model is more expensive and difficult to manipulate, its genetic, structural, functional, and even disease similarities to humans make it an ideal model to first consider. This review presents the commonly-used large animals—dog, sheep, pig, and non-human primates—while the less-used other large animals—cows, horses—are excluded. The review attempts to introduce unique points for each species regarding its biological property, degrees of susceptibility to develop certain types of heart diseases, and methodology of induced conditions. For example, dogs barely develop myocardial infarction, while dilated cardiomyopathy is developed quite often. Based on the similarities of each species to the human, the model selection may first consider non-human primates—pig, sheep, then dog—but it also depends on other factors, for example, purposes, funding, ethics, and policy. We hope this review can serve as a basic outline of large animal models for cardiovascular researchers and clinicians. PMID:29367573

Assessment selection in human-automation interaction studies: The Failure-GAM2E and review of assessment methods for highly automated driving.

PubMed

Grane, Camilla

2018-01-01

Highly automated driving will change driver's behavioural patterns. Traditional methods used for assessing manual driving will only be applicable for the parts of human-automation interaction where the driver intervenes such as in hand-over and take-over situations. Therefore, driver behaviour assessment will need to adapt to the new driving scenarios. This paper aims at simplifying the process of selecting appropriate assessment methods. Thirty-five papers were reviewed to examine potential and relevant methods. The review showed that many studies still relies on traditional driving assessment methods. A new method, the Failure-GAM 2 E model, with purpose to aid assessment selection when planning a study, is proposed and exemplified in the paper. Failure-GAM 2 E includes a systematic step-by-step procedure defining the situation, failures (Failure), goals (G), actions (A), subjective methods (M), objective methods (M) and equipment (E). The use of Failure-GAM 2 E in a study example resulted in a well-reasoned assessment plan, a new way of measuring trust through feet movements and a proposed Optimal Risk Management Model. Failure-GAM 2 E and the Optimal Risk Management Model are believed to support the planning process for research studies in the field of human-automation interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relevant, irredundant feature selection and noisy example elimination.

PubMed

Lashkia, George V; Anthony, Laurence

2004-04-01

In many real-world situations, the method for computing the desired output from a set of inputs is unknown. One strategy for solving these types of problems is to learn the input-output functionality from examples in a training set. However, in many situations it is difficult to know what information is relevant to the task at hand. Subsequently, researchers have investigated ways to deal with the so-called problem of consistency of attributes, i.e., attributes that can distinguish examples from different classes. In this paper, we first prove that the notion of relevance of attributes is directly related to the consistency of attributes, and show how relevant, irredundant attributes can be selected. We then compare different relevant attribute selection algorithms, and show the superiority of algorithms that select irredundant attributes over those that select relevant attributes. We also show that searching for an "optimal" subset of attributes, which is considered to be the main purpose of attribute selection, is not the best way to improve the accuracy of classifiers. Employing sets of relevant, irredundant attributes improves classification accuracy in many more cases. Finally, we propose a new method for selecting relevant examples, which is based on filtering the so-called pattern frequency domain. By identifying examples that are nontypical in the determination of relevant, irredundant attributes, irrelevant examples can be eliminated prior to the learning process. Empirical results using artificial and real databases show the effectiveness of the proposed method in selecting relevant examples leading to improved performance even on greatly reduced training sets.

What methods do reviews of normative ethics literature use for search, selection, analysis, and synthesis? In-depth results from a systematic review of reviews.

PubMed

Mertz, Marcel; Strech, Daniel; Kahrass, Hannes

2017-12-19

(Semi-)systematic approaches to finding, analysing, and synthesising ethics literature on medical topics are still in their infancy. However, our recent systematic review showed that the rate of publication of such (semi-)systematic reviews has increased in the last two decades. This is not only true for reviews of empirical ethics literature, but also for reviews of normative ethics literature. In the latter case, there is currently little in the way of standards and guidance available. Therefore, the methods and reporting strategies of such reviews vary greatly. The purpose of the follow-up study we present was to obtain deeper methodological insight into the ways reviews of normative literature are actually conducted and to analyse the methods used. Our search in the PubMed, PhilPapers, and Google Scholar databases led to the identification of 183 reviews of ethics literature published between 1997 and 2015, of which 84 were identified as reviews of normative and mixed literature. Qualitative content analysis was used to extract and synthesise descriptions of search, selection, quality appraisal, analysis, and synthesis methods. We further assessed quantitatively how often certain methods (e.g. search strategies, data analysis procedures) were used by the reviews. The overall reporting quality varies among the analysed reviews and was generally poor even for major criteria regarding the search and selection of literature. For example, only 24 (29%) used a PRISMA flowchart. Also, only 55 (66%) reviews mentioned the information unit they sought to extract, and 12 (14%) stated an ethical approach as the theoretical basis for the analysis. Interpretable information on the synthesis method was given by 47 (60%); the most common methods applied were qualitative methods commonly used in social science research (83%). Reviews which fail to provide sufficient relevant information to readers have reduced methodological transparency regardless of actual methodological quality. In order to increase the internal validity (i.e. reproducibility) as well as the external validity (i.e. utility for the intended audience) of future reviews of normative literature, we suggest more accurate reporting regarding the goal of the review, the definition of the information unit, the ethical approach used, and technical aspects.

Integrating Electromagnetic Data with Other Geophysical Observations for Enhanced Imaging of the Earth: A Tutorial and Review

NASA Astrophysics Data System (ADS)

Moorkamp, Max

2017-09-01

In this review, I discuss the basic principles of joint inversion and constrained inversion approaches and show a few instructive examples of applications of these approaches in the literature. Starting with some basic definitions of the terms joint inversion and constrained inversion, I use a simple three-layered model as a tutorial example that demonstrates the general properties of joint inversion with different coupling methods. In particular, I investigate to which extent combining different geophysical methods can restrict the set of acceptable models and under which circumstances the results can be biased. Some ideas on how to identify such biased results and how negative results can be interpreted conclude the tutorial part. The case studies in the second part have been selected to highlight specific issues such as choosing an appropriate parameter relationship to couple seismic and electromagnetic data and demonstrate the most commonly used approaches, e.g., the cross-gradient constraint and direct parameter coupling. Throughout the discussion, I try to identify topics for future work. Overall, it appears that integrating electromagnetic data with other observations has reached a level of maturity and is starting to move away from fundamental proof-of-concept studies to answering questions about the structure of the subsurface. With a wide selection of coupling methods suited to different geological scenarios, integrated approaches can be applied on all scales and have the potential to deliver new answers to important geological questions.

Review of the progress toward achieving heat confinement-the holy grail of photothermal therapy

NASA Astrophysics Data System (ADS)

Sheng, Wangzhong; He, Sha; Seare, William J.; Almutairi, Adah

2017-08-01

Photothermal therapy (PTT) involves the application of normally benign light wavelengths in combination with efficient photothermal (PT) agents that convert the absorbed light to heat to ablate selected cancers. The major challenge in PTT is the ability to confine heating and thus direct cellular death to precisely where PT agents are located. The dominant strategy in the field has been to create large libraries of PT agents with increased absorption capabilities and to enhance their delivery and accumulation to achieve sufficiently high concentrations in the tissue targets of interest. While the challenge of material confinement is important for achieving "heat and lethality confinement," this review article suggests another key prospective strategy to make this goal a reality. In this approach, equal emphasis is placed on selecting parameters of light exposure, including wavelength, duration, power density, and total power supplied, based on the intrinsic properties and geometry of tissue targets that influence heat dissipation, to truly achieve heat confinement. This review highlights significant milestones researchers have achieved, as well as examples that suggest future research directions, in this promising technique, as it becomes more relevant in clinical cancer therapy and other noncancer applications.

Review, evaluation, and discussion of the challenges of missing value imputation for mass spectrometry-based label-free global proteomics

DOE PAGES

Webb-Robertson, Bobbie-Jo M.; Wiberg, Holli K.; Matzke, Melissa M.; ...

2015-04-09

In this review, we apply selected imputation strategies to label-free liquid chromatography–mass spectrometry (LC–MS) proteomics datasets to evaluate the accuracy with respect to metrics of variance and classification. We evaluate several commonly used imputation approaches for individual merits and discuss the caveats of each approach with respect to the example LC–MS proteomics data. In general, local similarity-based approaches, such as the regularized expectation maximization and least-squares adaptive algorithms, yield the best overall performances with respect to metrics of accuracy and robustness. However, no single algorithm consistently outperforms the remaining approaches, and in some cases, performing classification without imputation sometimes yieldedmore » the most accurate classification. Thus, because of the complex mechanisms of missing data in proteomics, which also vary from peptide to protein, no individual method is a single solution for imputation. In summary, on the basis of the observations in this review, the goal for imputation in the field of computational proteomics should be to develop new approaches that work generically for this data type and new strategies to guide users in the selection of the best imputation for their dataset and analysis objectives.« less

A systematic review of visual image theory, assessment, and use in skin cancer and tanning research.

PubMed

McWhirter, Jennifer E; Hoffman-Goetz, Laurie

2014-01-01

Visual images increase attention, comprehension, and recall of health information and influence health behaviors. Health communication campaigns on skin cancer and tanning often use visual images, but little is known about how such images are selected or evaluated. A systematic review of peer-reviewed, published literature on skin cancer and tanning was conducted to determine (a) what visual communication theories were used, (b) how visual images were evaluated, and (c) how visual images were used in the research studies. Seven databases were searched (PubMed/MEDLINE, EMBASE, PsycINFO, Sociological Abstracts, Social Sciences Full Text, ERIC, and ABI/INFORM) resulting in 5,330 citations. Of those, 47 met the inclusion criteria. Only one study specifically identified a visual communication theory guiding the research. No standard instruments for assessing visual images were reported. Most studies lacked, to varying degrees, comprehensive image description, image pretesting, full reporting of image source details, adequate explanation of image selection or development, and example images. The results highlight the need for greater theoretical and methodological attention to visual images in health communication research in the future. To this end, the authors propose a working definition of visual health communication.

The Synthesis of Fragrant Natural Products from Santalum album L.: (+)-(Z)-α-Santalol and (-)-(Z)-β-Santalol.

PubMed

Birkbeck, Anthony A

2017-12-01

The synthetic challenges associated with the selective synthesis of α-Santalene (1), (Z)-α-Santalol (2), β-Santalene (3), and most importantly (Z)-β-Santalol (4) have interested the world's synthetic chemists for decades. These molecules, lovely examples of nature's exquisite creations, have been isolated from East Indian Sandalwood Oil (Santalum album L.) and have stimulated chemists to develop new and efficient methodologies to synthesize them. The synthesis and evolution of various approaches to the [2.2.1]bicycloheptane ring system present in β-Santalene (3) and the even more challenging selective synthesis of the (Z)-allylic alcohol sidechain present in both (Z)-α-Santalol (2) and ((Z)-β-Santalol (4) will be covered in this review.

Towards mild metal-catalyzed C-H bond activation.

PubMed

Wencel-Delord, Joanna; Dröge, Thomas; Liu, Fan; Glorius, Frank

2011-09-01

Functionalizing traditionally inert carbon-hydrogen bonds represents a powerful transformation in organic synthesis, providing new entries to valuable structural motifs and improving the overall synthetic efficiency. C-H bond activation, however, often necessitates harsh reaction conditions that result in functional group incompatibilities and limited substrate scope. An understanding of the reaction mechanism and rational design of experimental conditions have led to significant improvement in both selectivity and applicability. This critical review summarizes and discusses endeavours towards the development of mild C-H activation methods and wishes to trigger more research towards this goal. In addition, we examine select examples in complex natural product synthesis to demonstrate the synthetic utility of mild C-H functionalization (84 references). This journal is © The Royal Society of Chemistry 2011

Methods to Improve the Selection and Tailoring of Implementation Strategies

PubMed Central

Powell, Byron J.; Beidas, Rinad S.; Lewis, Cara C.; Aarons, Gregory A.; McMillen, J. Curtis; Proctor, Enola K.; Khinduka, Shanti K.; Mandell, David S.

2015-01-01

Implementing behavioral health interventions is a complicated process. It has been suggested that implementation strategies should be selected and tailored to address the contextual needs of a given change effort; however, there is limited guidance as to how to do this. This article proposes four methods (concept mapping, group model building, conjoint analysis, and intervention mapping) that could be used to match implementation strategies to identified barriers and facilitators for a particular evidence-based practice or process change being implemented in a given setting. Each method is reviewed, examples of their use are provided, and their strengths and weaknesses are discussed. The discussion includes suggestions for future research pertaining to implementation strategies and highlights these methods' relevance to behavioral health services and research. PMID:26289563

The Analysis of Emission Lines; A Meeting in Honour of the 70th Birthdays of D. E. Osterbrock and M. J. Seaton

NASA Technical Reports Server (NTRS)

Williams, Robert (Editor); Livio, Mario (Editor); Dufour, Reginald J.

1994-01-01

A review of the field of astronomical spectroscopy with emphasis on emission lines in astrophysical plasmas is presented. A brief history of UV spectroscopy instruments is given, following by a discussion and tabulation of major atlases of UV emission-line objects to date (mid-1994). A discussion of the major diagnostic UV emission lines in the approx. 912-3200 A spectral region that are useful for determining electron densities, temperatures, abundances, and extinction in low- to moderate density plasmas is given, with examples of applications to selected objects. The review concludes by presenting some recent results from HST, HUT, and IUE on UV emission-line spectroscopy of nebulae and active galaxies.

Applications of Nonenzymatic Catalysts to the Alteration of Natural Products.

PubMed

Shugrue, Christopher R; Miller, Scott J

2017-09-27

The application of small molecules as catalysts for the diversification of natural product scaffolds is reviewed. Specifically, principles that relate to the selectivity challenges intrinsic to complex molecular scaffolds are summarized. The synthesis of analogues of natural products by this approach is then described as a quintessential "late-stage functionalization" exercise wherein natural products serve as the lead scaffolds. Given the historical application of enzymatic catalysts to the site-selective alteration of complex molecules, the focus of this Review is on the recent studies of nonenzymatic catalysts. Reactions involving hydroxyl group derivatization with a variety of electrophilic reagents are discussed. C-H bond functionalizations that lead to oxidations, aminations, and halogenations are also presented. Several examples of site-selective olefin functionalizations and C-C bond formations are also included. Numerous classes of natural products have been subjected to these studies of site-selective alteration including polyketides, glycopeptides, terpenoids, macrolides, alkaloids, carbohydrates, and others. What emerges is a platform for chemical remodeling of naturally occurring scaffolds that targets virtually all known chemical functionalities and microenvironments. However, challenges for the design of very broad classes of catalysts, with even broader selectivity demands (e.g., stereoselectivity, functional group selectivity, and site-selectivity) persist. Yet, a significant spectrum of powerful, catalytic alterations of complex natural products now exists such that expansion of scope seems inevitable. Several instances of biological activity assays of remodeled natural product derivatives are also presented. These reports may foreshadow further interdisciplinary impacts for catalytic remodeling of natural products, including contributions to SAR development, mode of action studies, and eventually medicinal chemistry.

Reviewing methodologically disparate data: a practical guide for the patient safety research field.

PubMed

Brown, Katrina F; Long, Susannah J; Athanasiou, Thanos; Vincent, Charles A; Kroll, J Simon; Sevdalis, Nick

2012-02-01

This article addresses key questions frequently asked by researchers conducting systematic reviews in patient safety. This discipline is relatively young, and asks complex questions about complex aspects of health care delivery and experience, therefore its studies are typically methodologically heterogeneous, non-randomized and complex; but content rich and highly relevant to practice. Systematic reviews are increasingly necessary to drive forward practice and research in this area, but the data do not always lend themselves to 'standard' review methodologies. This accessible 'how-to' article demonstrates that data diversity need not preclude high-quality systematic reviews. It draws together information from published guidelines and experience within our multidisciplinary patient safety research group to provide entry-level advice for the clinician-researcher new to systematic reviewing, to non-biomedical research data or to both. It offers entry-level advice, illustrated with detailed practical examples, on defining a research question, creating a comprehensive search strategy, selecting articles for inclusion, assessing study quality, extracting data, synthesizing data and evaluating the impact of your review. The article concludes with a comment on the vital role of robust systematic reviews in the continuing advancement of the patient safety field. © 2010 Blackwell Publishing Ltd.

Structural insights into ligand recognition and selectivity for class A, B, and C GPCRs

PubMed Central

Lee, Sang-Min; Booe, Jason M.; Pioszak, Augen A.

2015-01-01

The G protein-coupled receptor (GPCR) superfamily constitutes the largest collection of cell surface signaling proteins with approximately 800 members in the human genome. GPCRs regulate virtually all aspects of physiology and they are an important class of drug targets with ~30% of drugs on the market targeting a GPCR. Breakthroughs in GPCR structural biology in recent years have significantly expanded our understanding of GPCR structure and function and ushered in a new era of structure-based drug design for GPCRs. Crystal structures for nearly thirty distinct GPCRs are now available including receptors from each of the major classes, A, B, C, and F. These structures provide a foundation for understanding the molecular basis of GPCR pharmacology. Here, we review structural mechanisms of ligand recognition and selectivity of GPCRs with a focus on selected examples from classes A, B, and C, and we highlight major unresolved questions for future structural studies. PMID:25981303

Microsystems for the Capture of Low-Abundance Cells

NASA Astrophysics Data System (ADS)

Dharmasiri, Udara; Witek, Małgorzata A.; Adams, Andre A.; Soper, Steven A.

2010-07-01

Efficient selection and enumeration of low-abundance biological cells are highly important in a variety of applications. For example, the clinical utility of circulating tumor cells (CTCs) in peripheral blood is recognized as a viable biomarker for the management of various cancers, in which the clinically relevant number of CTCs per 7.5 ml of blood is two to five. Although there are several methods for isolating rare cells from a variety of heterogeneous samples, such as immunomagnetic-assisted cell sorting and fluorescence-activated cell sorting, they are fraught with challenges. Microsystem-based technologies are providing new opportunities for selecting and isolating rare cells from complex, heterogeneous samples. Such approaches involve reductions in target-cell loss, process automation, and minimization of contamination issues. In this review, we introduce different application areas requiring rare cell analysis, conventional techniques for their selection, and finally microsystem approaches for low-abundance-cell isolation and enumeration.

Set selection dynamical system neural networks with partial memories, with applications to Sudoku and KenKen puzzles.

PubMed

Boreland, B; Clement, G; Kunze, H

2015-08-01

After reviewing set selection and memory model dynamical system neural networks, we introduce a neural network model that combines set selection with partial memories (stored memories on subsets of states in the network). We establish that feasible equilibria with all states equal to ± 1 correspond to answers to a particular set theoretic problem. We show that KenKen puzzles can be formulated as a particular case of this set theoretic problem and use the neural network model to solve them; in addition, we use a similar approach to solve Sudoku. We illustrate the approach in examples. As a heuristic experiment, we use online or print resources to identify the difficulty of the puzzles and compare these difficulties to the number of iterations used by the appropriate neural network solver, finding a strong relationship. Copyright © 2015 Elsevier Ltd. All rights reserved.

The history of the human female inferiority ideas in evolutionary biology.

PubMed

Bergman, Gerald

2002-01-01

A review of the prominent late 19th-century biological writings reveals that a major plank of early evolution theory was the belief that women were intellectually and physically inferior to men. Female inferiority was a logical conclusion of the Darwinian world view because males were believed to be exposed to far greater selective pressures than females, especially in war, competition for mates, food and clothing. Conversely, women were protected from selection by norms that required adult males provide for and protect women and children. Darwinists taught that as a result of this protection, natural selection operated far more actively on males than on females, producing male superiority in virtually all intellectual and skill areas. As a result, males became "more evolved" than women. The women inferiority doctrine is an excellent example of the fact that armchair logic often has been more important in building Darwinism than fossil and other empirical evidence.

Monitoring Ion Activities In and Around Cells Using Ion-Selective Liquid-Membrane Microelectrodes

PubMed Central

Lee, Seong-Ki; Boron, Walter F.; Parker, Mark D.

2013-01-01

Determining the effective concentration (i.e., activity) of ions in and around living cells is important to our understanding of the contribution of those ions to cellular function. Moreover, monitoring changes in ion activities in and around cells is informative about the actions of the transporters and/or channels operating in the cell membrane. The activity of an ion can be measured using a glass microelectrode that includes in its tip a liquid-membrane doped with an ion-selective ionophore. Because these electrodes can be fabricated with tip diameters that are less than 1 μm, they can be used to impale single cells in order to monitor the activities of intracellular ions. This review summarizes the history, theory, and practice of ion-selective microelectrode use and brings together a number of classic and recent examples of their usefulness in the realm of physiological study. PMID:23322102

Molecular recognition of organic ammonium ions in solution using synthetic receptors

PubMed Central

Späth, Andreas

2010-01-01

Summary Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation–π interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications. PMID:20502608

Logarithmic conformal field theory: beyond an introduction

NASA Astrophysics Data System (ADS)

Creutzig, Thomas; Ridout, David

2013-12-01

This article aims to review a selection of central topics and examples in logarithmic conformal field theory. It begins with the remarkable observation of Cardy that the horizontal crossing probability of critical percolation may be computed analytically within the formalism of boundary conformal field theory. Cardy’s derivation relies on certain implicit assumptions which are shown to lead inexorably to indecomposable modules and logarithmic singularities in correlators. For this, a short introduction to the fusion algorithm of Nahm, Gaberdiel and Kausch is provided. While the percolation logarithmic conformal field theory is still not completely understood, there are several examples for which the formalism familiar from rational conformal field theory, including bulk partition functions, correlation functions, modular transformations, fusion rules and the Verlinde formula, has been successfully generalized. This is illustrated for three examples: the singlet model \\mathfrak {M} (1,2), related to the triplet model \\mathfrak {W} (1,2), symplectic fermions and the fermionic bc ghost system; the fractional level Wess-Zumino-Witten model based on \\widehat{\\mathfrak {sl}} \\left( 2 \\right) at k=-\\frac{1}{2}, related to the bosonic βγ ghost system; and the Wess-Zumino-Witten model for the Lie supergroup \\mathsf {GL} \\left( 1 {\\mid} 1 \\right), related to \\mathsf {SL} \\left( 2 {\\mid} 1 \\right) at k=-\\frac{1}{2} and 1, the Bershadsky-Polyakov algebra W_3^{(2)} and the Feigin-Semikhatov algebras W_n^{(2)}. These examples have been chosen because they represent the most accessible, and most useful, members of the three best-understood families of logarithmic conformal field theories. The logarithmic minimal models \\mathfrak {W} (q,p), the fractional level Wess-Zumino-Witten models, and the Wess-Zumino-Witten models on Lie supergroups (excluding \\mathsf {OSP} \\left( 1 {\\mid} 2n \\right)). In this review, the emphasis lies on the representation theory of the underlying chiral algebra and the modular data pertaining to the characters of the representations. Each of the archetypal logarithmic conformal field theories is studied here by first determining its irreducible spectrum, which turns out to be continuous, as well as a selection of natural reducible, but indecomposable, modules. This is followed by a detailed description of how to obtain character formulae for each irreducible, a derivation of the action of the modular group on the characters, and an application of the Verlinde formula to compute the Grothendieck fusion rules. In each case, the (genuine) fusion rules are known, so comparisons can be made and favourable conclusions drawn. In addition, each example admits an infinite set of simple currents, hence extended symmetry algebras may be constructed and a series of bulk modular invariants computed. The spectrum of such an extended theory is typically discrete and this is how the triplet model \\mathfrak {W} (1,2) arises, for example. Moreover, simple current technology admits a derivation of the extended algebra fusion rules from those of its continuous parent theory. Finally, each example is concluded by a brief description of the computation of some bulk correlators, a discussion of the structure of the bulk state space, and remarks concerning more advanced developments and generalizations. The final part gives a very short account of the theory of staggered modules, the (simplest class of) representations that are responsible for the logarithmic singularities that distinguish logarithmic theories from their rational cousins. These modules are discussed in a generality suitable to encompass all the examples met in this review and some of the very basic structure theory is proven. Then, the important quantities known as logarithmic couplings are reviewed for Virasoro staggered modules and their role as fundamentally important parameters, akin to the three-point constants of rational conformal field theory, is discussed. An appendix is also provided in order to introduce some of the necessary, but perhaps unfamiliar, language of homological algebra.

Sample Preparation for Mass Spectrometry Imaging of Plant Tissues: A Review

PubMed Central

Dong, Yonghui; Li, Bin; Malitsky, Sergey; Rogachev, Ilana; Aharoni, Asaph; Kaftan, Filip; Svatoš, Aleš; Franceschi, Pietro

2016-01-01

Mass spectrometry imaging (MSI) is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining agents. These advantages make it an attractive molecular histology tool in medical, pharmaceutical, and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of MSI techniques in plants are reviewed according to different classes of plant metabolites. PMID:26904042

Hydrophobic and Hydrophilic Au and Ag Nanoparticles. Breakthroughs and Perspectives

PubMed Central

2017-01-01

This review provides a broad look on the recent investigations on the synthesis, characterization and physico-chemical properties of noble metal nanoparticles, mainly gold and silver nanoparticles, stabilized with ligands of different chemical nature. A comprehensive review of the available literature in this field may be far too large and only some selected representative examples will be reported here, together with some recent achievements from our group, that will be discussed in more detail. Many efforts in finding synthetic routes have been performed so far to achieve metal nanoparticles with well-defined size, morphology and stability in different environments, to match the large variety of applications that can be foreseen for these materials. In particular, the synthesis and stabilization of gold and silver nanoparticles together with their properties in different emerging fields of nanomedicine, optics and sensors are reviewed and briefly commented. PMID:29280980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bell, Nelson S.; Sarobol, Pylin; Cook, Adam

There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

Adaptive seamless designs: selection and prospective testing of hypotheses.

PubMed

Jennison, Christopher; Turnbull, Bruce W

2007-01-01

There is a current trend towards clinical protocols which involve an initial "selection" phase followed by a hypothesis testing phase. The selection phase may involve a choice between competing treatments or different dose levels of a drug, between different target populations, between different endpoints, or between a superiority and a non-inferiority hypothesis. Clearly there can be benefits in elapsed time and economy in organizational effort if both phases can be designed up front as one experiment, with little downtime between phases. Adaptive designs have been proposed as a way to handle these selection/testing problems. They offer flexibility and allow final inferences to depend on data from both phases, while maintaining control of overall false positive rates. We review and critique the methods, give worked examples and discuss the efficiency of adaptive designs relative to more conventional procedures. Where gains are possible using the adaptive approach, a variety of logistical, operational, data handling and other practical difficulties remain to be overcome if adaptive, seamless designs are to be effectively implemented.

The Importance of Method Selection in Determining Product Integrity for Nutrition Research1234

PubMed Central

Mudge, Elizabeth M; Brown, Paula N

2016-01-01

The American Herbal Products Association estimates that there as many as 3000 plant species in commerce. The FDA estimates that there are about 85,000 dietary supplement products in the marketplace. The pace of product innovation far exceeds that of analytical methods development and validation, with new ingredients, matrixes, and combinations resulting in an analytical community that has been unable to keep up. This has led to a lack of validated analytical methods for dietary supplements and to inappropriate method selection where methods do exist. Only after rigorous validation procedures to ensure that methods are fit for purpose should they be used in a routine setting to verify product authenticity and quality. By following systematic procedures and establishing performance requirements for analytical methods before method development and validation, methods can be developed that are both valid and fit for purpose. This review summarizes advances in method selection, development, and validation regarding herbal supplement analysis and provides several documented examples of inappropriate method selection and application. PMID:26980823

SIGNALING EFFICACY DRIVES THE EVOLUTION OF LARGER SEXUAL ORNAMENTS BY SEXUAL SELECTION

PubMed Central

Tazzyman, Samuel J; Iwasa, Yoh; Pomiankowski, Andrew

2014-01-01

Why are there so few small secondary sexual characters? Theoretical models predict that sexual selection should lead to reduction as often as exaggeration, and yet we mainly associate secondary sexual ornaments with exaggerated features such as the peacock's tail. We review the literature on mate choice experiments for evidence of reduced sexual traits. This shows that reduced ornamentation is effectively impossible in certain types of ornamental traits (behavioral, pheromonal, or color-based traits, and morphological ornaments for which the natural selection optimum is no trait), but that there are many examples of morphological traits that would permit reduction. Yet small sexual traits are very rarely seen. We analyze a simple mathematical model of Fisher's runaway process (the null model for sexual selection). Our analysis shows that the imbalance cannot be wholly explained by larger ornaments being less costly than smaller ornaments, nor by preferences for larger ornaments being less costly than preferences for smaller ornaments. Instead, we suggest that asymmetry in signaling efficacy limits runaway to trait exaggeration. PMID:24099137

Spacecraft flight control system design selection process for a geostationary communication satellite

NASA Technical Reports Server (NTRS)

Barret, C.

1992-01-01

The Earth's first artificial satellite, Sputnik 1, slowly tumbled in orbit. The first U.S. satellite, Explorer 1, also tumbled out of control. Now, as we launch the Mars observer and the Cassini spacecraft, stability and control have become higher priorities. The flight control system design selection process is reviewed using as an example a geostationary communication satellite which is to have a life expectancy of 10 to 14 years. Disturbance torques including aerodynamic, magnetic, gravity gradient, solar, micrometeorite, debris, collision, and internal torques are assessed to quantify the disturbance environment so that the required compensating torque can be determined. Then control torque options, including passive versus active, momentum control, bias momentum, spin stabilization, dual spin, gravity gradient, magnetic, reaction wheels, control moment gyros, nutation dampers, inertia augmentation techniques, three-axis control, reactions control system (RCS), and RCS sizing, are considered. A flight control system design is then selected and preliminary stability criteria are met by the control gains selection.

Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural perspective

PubMed Central

Zion Golumbic, Elana M.; Poeppel, David; Schroeder, Charles E.

2012-01-01

The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘active sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

The Importance of Method Selection in Determining Product Integrity for Nutrition Research.

PubMed

Mudge, Elizabeth M; Betz, Joseph M; Brown, Paula N

2016-03-01

The American Herbal Products Association estimates that there as many as 3000 plant species in commerce. The FDA estimates that there are about 85,000 dietary supplement products in the marketplace. The pace of product innovation far exceeds that of analytical methods development and validation, with new ingredients, matrixes, and combinations resulting in an analytical community that has been unable to keep up. This has led to a lack of validated analytical methods for dietary supplements and to inappropriate method selection where methods do exist. Only after rigorous validation procedures to ensure that methods are fit for purpose should they be used in a routine setting to verify product authenticity and quality. By following systematic procedures and establishing performance requirements for analytical methods before method development and validation, methods can be developed that are both valid and fit for purpose. This review summarizes advances in method selection, development, and validation regarding herbal supplement analysis and provides several documented examples of inappropriate method selection and application. © 2016 American Society for Nutrition.

Use of game-theoretical methods in biochemistry and biophysics.

PubMed

Schuster, Stefan; Kreft, Jan-Ulrich; Schroeter, Anja; Pfeiffer, Thomas

2008-04-01

Evolutionary game theory can be considered as an extension of the theory of evolutionary optimisation in that two or more organisms (or more generally, units of replication) tend to optimise their properties in an interdependent way. Thus, the outcome of the strategy adopted by one species (e.g., as a result of mutation and selection) depends on the strategy adopted by the other species. In this review, the use of evolutionary game theory for analysing biochemical and biophysical systems is discussed. The presentation is illustrated by a number of instructive examples such as the competition between microorganisms using different metabolic pathways for adenosine triphosphate production, the secretion of extracellular enzymes, the growth of trees and photosynthesis. These examples show that, due to conflicts of interest, the global optimum (in the sense of being the best solution for the whole system) is not always obtained. For example, some yeast species use metabolic pathways that waste nutrients, and in a dense tree canopy, trees grow taller than would be optimal for biomass productivity. From the viewpoint of game theory, the examples considered can be described by the Prisoner's Dilemma, snowdrift game, Tragedy of the Commons and rock-scissors-paper game.

Hot spot-based design of small-molecule inhibitors for protein-protein interactions.

PubMed

Guo, Wenxing; Wisniewski, John A; Ji, Haitao

2014-06-01

Protein-protein interactions (PPIs) are important targets for the development of chemical probes and therapeutic agents. From the initial discovery of the existence of hot spots at PPI interfaces, it has been proposed that hot spots might provide the key for developing small-molecule PPI inhibitors. However, there has been no review on the ways in which the knowledge of hot spots can be used to achieve inhibitor design, nor critical examination of successful examples. This Digest discusses the characteristics of hot spots and the identification of druggable hot spot pockets. An analysis of four examples of hot spot-based design reveals the importance of this strategy in discovering potent and selective PPI inhibitors. A general procedure for hot spot-based design of PPI inhibitors is outlined. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dynamic combinatorial libraries: from exploring molecular recognition to systems chemistry.

PubMed

Li, Jianwei; Nowak, Piotr; Otto, Sijbren

2013-06-26

Dynamic combinatorial chemistry (DCC) is a subset of combinatorial chemistry where the library members interconvert continuously by exchanging building blocks with each other. Dynamic combinatorial libraries (DCLs) are powerful tools for discovering the unexpected and have given rise to many fascinating molecules, ranging from interlocked structures to self-replicators. Furthermore, dynamic combinatorial molecular networks can produce emergent properties at systems level, which provide exciting new opportunities in systems chemistry. In this perspective we will highlight some new methodologies in this field and analyze selected examples of DCLs that are under thermodynamic control, leading to synthetic receptors, catalytic systems, and complex self-assembled supramolecular architectures. Also reviewed are extensions of the principles of DCC to systems that are not at equilibrium and may therefore harbor richer functional behavior. Examples include self-replication and molecular machines.

A review of the volatile metabolites of fungi found on wood substrates.

PubMed

McAfee, B J; Taylor, A

1999-01-01

The holdings of eight collections of fungi have been examined for organisms isolated from wood and/or trees. Further selection of these fungi has been made according to their reported ability to produce volatile, biologically active metabolites. It is emphasized that the isolates in the collections do not necessarily produce such metabolites. The list of fungi fulfilling these conditions is slightly augmented by reports we have found in the literature, where the fungi concerned have not yet been deposited. The biochemistry of these compounds is considered with particular emphasis on their biosynthesis including that by Homo sapiens. The physiological and toxicological activity of these metabolites is reviewed especially with reference to their potential role in the complex symbioses existent in, for example, a tree. The review concludes with a discussion of areas of botany deserving increased attention in the hope that this will stimulate further work. The statements in the review are based on 173 references.

Multivariate Analysis, Retrieval, and Storage System (MARS). Volume 6: MARS System - A Sample Problem (Gross Weight of Subsonic Transports)

NASA Technical Reports Server (NTRS)

Hague, D. S.; Woodbury, N. W.

1975-01-01

The Mars system is a tool for rapid prediction of aircraft or engine characteristics based on correlation-regression analysis of past designs stored in the data bases. An example of output obtained from the MARS system, which involves derivation of an expression for gross weight of subsonic transport aircraft in terms of nine independent variables is given. The need is illustrated for careful selection of correlation variables and for continual review of the resulting estimation equations. For Vol. 1, see N76-10089.

Programmable DNA switches and their applications.

PubMed

Harroun, Scott G; Prévost-Tremblay, Carl; Lauzon, Dominic; Desrosiers, Arnaud; Wang, Xiaomeng; Pedro, Liliana; Vallée-Bélisle, Alexis

2018-03-08

DNA switches are ideally suited for numerous nanotechnological applications, and increasing efforts are being directed toward their engineering. In this review, we discuss how to engineer these switches starting from the selection of a specific DNA-based recognition element, to its adaptation and optimisation into a switch, with applications ranging from sensing to drug delivery, smart materials, molecular transporters, logic gates and others. We provide many examples showcasing their high programmability and recent advances towards their real life applications. We conclude with a short perspective on this exciting emerging field.

Preliminary assessment of industrial needs for an advanced ocean technology

NASA Technical Reports Server (NTRS)

Mourad, A. G.; Maher, K. M.; Balon, J. E.; Coyle, A. G.; Henkener, J. A.

1979-01-01

A quick-look review of selected ocean industries is presented for the purpose of providing NASA OSTA with an assessment of technology needs and market potential. The size and growth potential, needs and problem areas, technology presently used and its suppliers, are given for industries involved in deep ocean mining, petrochemicals ocean energy conversion. Supporting services such as ocean bottom surveying; underwater transportation, data collection, and work systems; and inspection and diving services are included. Examples of key problem areas that are amenable to advanced technology solutions are included. Major companies are listed.

Gene-environment interactions in mental disorders

PubMed Central

Tsuang, Ming T; Bar, Jessica L; Stone, William S; Faraone, Stephen V

2004-01-01

Research clearly shows that both nature and nurture play important roles in the genesis of psychopathology. In this paper, we focus on 'gene-environment interaction' in mental disorders, using genetic control of sensitivity to the environment as our definition of that term. We begin with an examination of methodological issues involving gene-environment interactions, with examples concerning psychiatric and neurological conditions. Then we review the interactions in psychiatric disorders using twin, adoption and association designs. Finally, we consider gene-environment interactions in selected neurodevelopmental disorders (autism and schizophrenia). PMID:16633461

Physical approaches to biomaterial design

PubMed Central

Mitragotri, Samir; Lahann, Joerg

2009-01-01

The development of biomaterials for drug delivery, tissue engineering and medical diagnostics has traditionally been based on new chemistries. However, there is growing recognition that the physical as well as the chemical properties of materials can regulate biological responses. Here, we review this transition with regard to selected physical properties including size, shape, mechanical properties, surface texture and compartmentalization. In each case, we present examples demonstrating the significance of these properties in biology. We also discuss synthesis methods and biological applications for designer biomaterials, which offer unique physical properties. PMID:19096389

Recent developments in the hammerhead ribozyme field.

PubMed Central

Vaish, N K; Kore, A R; Eckstein, F

1998-01-01

Developments in the hammerhead ribozyme field during the last two years are reviewed here. New results on the specificity of this ribozyme, the mechanism of its action and on the question of metal ion involvement in the cleavage reaction are discussed. To demonstrate the potential of ribozyme technology examples of the application of this ribozyme for the inhibition of gene expression in cell culture, in animals, as well as in plant models are presented. Particular emphasis is given to critical steps in the approach, including RNA site selection, delivery, vector development and cassette construction. PMID:9826743

Samarium Diiodide-Mediated Reactions in Total Synthesis

PubMed Central

Nicolaou, K. C.; Ellery, Shelby P.; Chen, Jason S.

2009-01-01

Introduced by Henri Kagan more than three decades ago, samarium diiodide (SmI2) has found increasing applications in chemical synthesis. This single-electron reducing agent has been particularly useful in C–C bond formations, including those found in total synthesis endeavors. This Review highlights selected applications of SmI2 in total synthesis, with special emphasis on novel transformations and mechanistic considerations. The examples discussed are both illustrative of the power of this reagent in complex molecule construction and inspirational for the design of synthetic strategies toward such targets, both natural and designed. PMID:19714695

Whither motoneurons?

PubMed

Brownstone, Robert M; Stuart, Douglas G

2011-08-29

In the preceding series of articles, the history of vertebrate motoneuron and motor unit neurobiological studies has been discussed. In this article, we select a few examples of recent advances in neuroscience and discuss their application or potential application to the study of motoneurons and the control of movement. We conclude, like Sherrington, that in order to understand normal, traumatized, and diseased human behavior, it is critical to continue to study motoneuron biology using all available and emerging tools. This article is part of a Special Issue entitled Historical Review. 2011 Elsevier B.V. All rights reserved.

A Toolbox for Imaging Stellar Surfaces

NASA Astrophysics Data System (ADS)

Young, John

2018-04-01

In this talk I will review the available algorithms for synthesis imaging at visible and infrared wavelengths, including both gray and polychromatic methods. I will explain state-of-the-art approaches to constraining the ill-posed image reconstruction problem, and selecting an appropriate regularisation function and strength of regularisation. The reconstruction biases that can follow from non-optimal choices will be discussed, including their potential impact on the physical interpretation of the results. This discussion will be illustrated with example stellar surface imaging results from real VLTI and COAST datasets.

Hearings Before the Select Committee on Nutrition and Human Needs of the United States Senate, Ninety-Second Congress, First Session, on Nutrition and Human Needs. Part 1--Review of the Results of the White House Conference on Food, Nutrition, and Health; Part 2--Kansas City, Kansas.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Select Committee on Nutrition and Human Needs.

Contents of Part One include, in addition to the testimony of the witnesses called, such materials as: examples of citizen complaints, about the operation of school lunch programs; a report on the nutritional status of preschool Mexican-American farm children; a report on the Demonstration Migrant Nutrition Education Project, Edinburg, Texas; a…

Selected examples of intelligent (micro) sensor systems: state-of-the-art and tendencies

NASA Astrophysics Data System (ADS)

Hauptmann, Peter R.

2006-03-01

The capability of intelligent sensors to have more intelligence built into them continues to drive their application in areas including automotive, aerospace and defense, industrial, intelligent house and wear, medical and homeland security. In principle it is difficult to overestimate the importance of intelligent (micro) sensors or sensor systems within advanced societies but one characteristic feature is the global market for sensors, which is now about 20 billion annually. Therefore sensors or sensor systems play a dominant role in many fields from the macro sensor in manufacturing industry down to the miniaturized sensor for medical applications. The diversity of sensors precludes a complete description of the state-of-the-art; selected examples will illustrate the current situation. MEMS (microelectromechanical systems) devices are of special interest in the context of micro sensor systems. In past the main requirements of a sensor were in terms of metrological performance. The electrical (or optical) signal produced by the sensor needed to match the measure relatively accurately. Such basic functionality is no longer sufficient. Data processing near the sensor, the extraction of more information than just the direct sensor information by signal analysis, system aspects and multi-sensor information are the new demands. A shifting can be observed away from aiming to design perfect single-function transducers and towards the utilization of system-based sensors as system components. In the ideal case such systems contain sensors, actuators and electronics. They can be realized in monolithic, hybrid or discrete form—which kind is used depends on the application. In this article the state-of-the-art of intelligent sensors or sensor systems is reviewed using selected examples. Future trends are deduced.

Patient-centered innovation in health care organizations: a conceptual framework and case study application.

PubMed

Hernandez, Susan E; Conrad, Douglas A; Marcus-Smith, Miriam S; Reed, Peter; Watts, Carolyn

2013-01-01

Patient-centered innovation is spreading at the federal and state levels. A conceptual framework can help frame real-world examples and extract systematic learning from an array of innovative applications currently underway. The statutory, economic, and political environment in Washington State offers a special contextual laboratory for observing the interplay of these factors. We propose a framework for understanding the process of initiating patient-centered innovations-particularly innovations addressing patient-centered goals of improved access, continuity, communication and coordination, cultural competency, and family- and person-focused care over time. The framework to a case study of a provider organization in Washington State actively engaged in such innovations was applied in this article. We conducted a selective review of peer-reviewed evidence and theory regarding determinants of organizational change. On the basis of the literature review and the particular examples of patient-centric innovation, we developed a conceptual framework. Semistructured key informant interviews were conducted to illustrate the framework with concrete examples of patient-centered innovation. The primary determinants of initiating patient-centered innovation are (a) effective leadership, with the necessary technical and professional expertise and creative skills; (b) strong internal and external motivation to change; (c) clear and internally consistent organizational mission; (d) aligned organizational strategy; (e) robust organizational capability; and (f) continuous feedback and organizational learning. The internal hierarchy of actors is important in shaping patient-centered innovation. External financial incentives and government regulations also significantly shape innovation. Patient-centered care innovation is a complex process. A general framework that could help managers and executives organize their thoughts around innovation within their organization is presented.

What do we know about the effects of exposure to 'Low alcohol' and equivalent product labelling on the amounts of alcohol, food and tobacco people select and consume? A systematic review.

PubMed

Shemilt, Ian; Hendry, Vivien; Marteau, Theresa M

2017-01-12

Explicit labelling of lower strength alcohol products could reduce alcohol consumption by attracting more people to buy and drink such products instead of higher strength ones. Alternatively, it may lead to more consumption due to a 'self-licensing' mechanism. Equivalent labelling of food or tobacco (for example "Low fat" or "Low tar") could influence consumption of those products by similar mechanisms. This systematic review examined the effects of 'Low alcohol' and equivalent labelling of alcohol, food and tobacco products on selection, consumption, and perceptions of products among adults. A systematic review was conducted based on Cochrane methods. Electronic and snowball searches identified 26 eligible studies. Evidence from 12 randomised controlled trials (all on food) was assessed for risk of bias, synthesised using random effects meta-analysis, and interpreted in conjunction with evidence from 14 non-randomised studies (one on alcohol, seven on food and six on tobacco). Outcomes assessed were: quantities of the product (i) selected or (ii) consumed (primary outcomes - behaviours), (iii) intentions to select or consume the product, (iv) beliefs associated with it consumption, (v) product appeal, and (vi) understanding of the label (secondary outcomes - cognitions). Evidence for impacts on the primary outcomes (i.e. amounts selected or consumed) was overall of very low quality, showing mixed effects, likely to vary by specific label descriptors, products and population characteristics. Overall very low quality evidence suggested that exposure to 'Low alcohol' and equivalent labelling on alcohol, food and tobacco products can shift consumer perceptions of products, with the potential to 'self-licence' excess consumption. Considerable uncertainty remains about the effects of labels denoting low alcohol, and equivalent labels, on alcohol, food and tobacco selection and consumption. Independent, high-quality studies are urgently needed to inform policies on labelling regulations.

Histone deacetylases in monocyte/macrophage development, activation and metabolism: refining HDAC targets for inflammatory and infectious diseases.

PubMed

Das Gupta, Kaustav; Shakespear, Melanie R; Iyer, Abishek; Fairlie, David P; Sweet, Matthew J

2016-01-01

Macrophages have central roles in danger detection, inflammation and host defense, and consequently, these cells are intimately linked to most disease processes. Major advances in our understanding of the development and function of macrophages have recently come to light. For example, it is now clear that tissue-resident macrophages can be derived from either blood monocytes or through local proliferation of phagocytes that are originally seeded during embryonic development. Metabolic state has also emerged as a major control point for macrophage activation phenotypes. Herein, we review recent literature linking the histone deacetylase (HDAC) family of enzymes to macrophage development and activation, particularly in relation to these recent developments. There has been considerable interest in potential therapeutic applications for small molecule inhibitors of HDACs (HDACi), not only for cancer, but also for inflammatory and infectious diseases. However, the enormous range of molecular and cellular processes that are controlled by different HDAC enzymes presents a potential stumbling block to clinical development. We therefore present examples of how classical HDACs control macrophage functions, roles of specific HDACs in these processes and approaches for selective targeting of drugs, such as HDACi, to macrophages. Development of selective inhibitors of macrophage-expressed HDACs and/or selective delivery of pan HDACi to macrophages may provide avenues for enhancing efficacy of HDACi in therapeutic applications, while limiting unwanted side effects.

Histone deacetylases in monocyte/macrophage development, activation and metabolism: refining HDAC targets for inflammatory and infectious diseases

PubMed Central

Das Gupta, Kaustav; Shakespear, Melanie R; Iyer, Abishek; Fairlie, David P; Sweet, Matthew J

2016-01-01

Macrophages have central roles in danger detection, inflammation and host defense, and consequently, these cells are intimately linked to most disease processes. Major advances in our understanding of the development and function of macrophages have recently come to light. For example, it is now clear that tissue-resident macrophages can be derived from either blood monocytes or through local proliferation of phagocytes that are originally seeded during embryonic development. Metabolic state has also emerged as a major control point for macrophage activation phenotypes. Herein, we review recent literature linking the histone deacetylase (HDAC) family of enzymes to macrophage development and activation, particularly in relation to these recent developments. There has been considerable interest in potential therapeutic applications for small molecule inhibitors of HDACs (HDACi), not only for cancer, but also for inflammatory and infectious diseases. However, the enormous range of molecular and cellular processes that are controlled by different HDAC enzymes presents a potential stumbling block to clinical development. We therefore present examples of how classical HDACs control macrophage functions, roles of specific HDACs in these processes and approaches for selective targeting of drugs, such as HDACi, to macrophages. Development of selective inhibitors of macrophage-expressed HDACs and/or selective delivery of pan HDACi to macrophages may provide avenues for enhancing efficacy of HDACi in therapeutic applications, while limiting unwanted side effects. PMID:26900475

Advances in antivirals for non-influenza respiratory virus infections.

PubMed

Hayden, Frederick G

2013-11-01

Progress in the development of antivirals for non-influenza respiratory viruses has been slow with the result that many unmet medical needs and few approved agents currently exist. This commentary selectively reviews examples of where specific agents have provided promising clinical benefits in selected target populations and also considers potential therapeutics for emerging threats like the SARS and Middle East respiratory syndrome coronaviruses. Recent studies have provided encouraging results in treating respiratory syncytial virus infections in lung transplant recipients, serious parainfluenza virus and adenovirus infections in immunocompromised hosts, and rhinovirus colds in outpatient asthmatics. While additional studies are needed to confirm the efficacy and safety of the specific agents tested, these observations offer the opportunity to expand therapeutic studies to other patient populations. © 2013 Blackwell Publishing Ltd.

Optical coating technology for the EUV

NASA Astrophysics Data System (ADS)

Osantowski, J. F.; Keski-Kuha, R. A. M.; Herzig, H.; Toft, A. R.; Gum, J. S.; Fleetwood, C. M.

Adavaces in optical coating and materials technology are one of the key motivators for the development of missions such as the Far Ultraviolet Spectroscopic Explorer recently selected by NASA for an Explorer class mission in the mid 1990's. The performance of a range of candidate coatings are reviewed for normal-incidence and glancing-incidence applications, and attention is given to strengths and problem areas for their use in space. The importance of recent developments in multilayer films, chemical-vapor deposited SiC (CVD-SiC) mirrors, and SiC films are discussed in the context of EUV instrumentation design. For example, the choice of optical coatings is a design driver for the selection of the average glancing angle for the FUSE telescope, and impacts efficiency, short-wavelength cut-off, and physical size.

Optical coating technology for the EUV

NASA Technical Reports Server (NTRS)

Osantowski, J. F.; Keski-Kuha, R. A. M.; Herzig, H.; Toft, A. R.; Gum, J. S.; Fleetwood, C. M.

1991-01-01

Advances in optical coating and materials technology are one of the key motivators for the development of missions such as the Far Ultraviolet Spectroscopic Explorer recently selected by NASA for an Explorer class mission in the mid 1990's. The performance of a range of candidate coatings are reviewed for normal-incidence and glancing-incidence applications, and attention is given to strengths and problem areas for their use in space. The importance of recent developments in multilayer films, chemical-vapor deposited SiC (CVD-SiC) mirrors, and SiC films are discussed in the context of EUV instrumentation design. For example, the choice of optical coatings is a design driver for the selection of the average glancing angle for the FUSE telescope, and impacts efficiency, short-wavelength cut-off, and physical size.

Genome-Wide Association Studies of Drug-Resistance Determinants.

PubMed

Volkman, Sarah K; Herman, Jonathan; Lukens, Amanda K; Hartl, Daniel L

2017-03-01

Population genetic strategies that leverage association, selection, and linkage have identified drug-resistant loci. However, challenges and limitations persist in identifying drug-resistance loci in malaria. In this review we discuss the genetic basis of drug resistance and the use of genome-wide association studies, complemented by selection and linkage studies, to identify and understand mechanisms of drug resistance and response. We also discuss the implications of nongenetic mechanisms of drug resistance recently reported in the literature, and present models of the interplay between nongenetic and genetic processes that contribute to the emergence of drug resistance. Throughout, we examine artemisinin resistance as an example to emphasize challenges in identifying phenotypes suitable for population genetic studies as well as complications due to multiple-factor drug resistance. Copyright © 2016. Published by Elsevier Ltd.

Homogeneous Biosensing Based on Magnetic Particle Labels

PubMed Central

Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang J.; Lentijo-Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Guenther, Annegret; Tschöpe, Andreas; Schotter, Joerg

2016-01-01

The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation. PMID:27275824

Developments in coupled solid-phase extraction-capillary electrophoresis 2013-2015.

PubMed

Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

2016-01-01

An overview of the design and application of coupled solid-phase extraction-capillary electrophoresis (SPE-CE) systems reported in the literature between July 2013 and June 2015 is provided in this paper. The present article is a continuation of our previous review papers on this topic which covered the time period 2000-2013 (Electrophoresis 2008, 29, 108-128; Electrophoresis 2010, 31, 44-54; Electrophoresis 2012, 33, 243-250; Electrophoresis 2014, 35, 128-137). The use of in-line and on-line SPE-CE approaches is treated and outlined in this review. Recent advancements, such as, for example, the use of aptamers as affinity material for in-line SPE-CE, the use of a bead string design for in-line fritless SPE-CE, and new interfacing techniques for the on-line coupling of SPE to CE, are outlined. Selected examples demonstrate the applicability of the coupled SPE-CE systems for biomedical, pharmaceutical, environmental, and food studies. A complete overview of the recent SPE-CE studies is given in table format, providing information on sample type, SPE sorbent, coupling mode, detection mode, and LOD. Finally, some general conclusions and perspectives are provided. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Basics of Antibody Phage Display Technology.

PubMed

Ledsgaard, Line; Kilstrup, Mogens; Karatt-Vellatt, Aneesh; McCafferty, John; Laustsen, Andreas H

2018-06-09

Antibody discovery has become increasingly important in almost all areas of modern medicine. Different antibody discovery approaches exist, but one that has gained increasing interest in the field of toxinology and antivenom research is phage display technology. In this review, the lifecycle of the M13 phage and the basics of phage display technology are presented together with important factors influencing the success rates of phage display experiments. Moreover, the pros and cons of different antigen display methods and the use of naïve versus immunized phage display antibody libraries is discussed, and selected examples from the field of antivenom research are highlighted. This review thus provides in-depth knowledge on the principles and use of phage display technology with a special focus on discovery of antibodies that target animal toxins.

Review: Semiconductor Piezoresistance for Microsystems.

PubMed

Barlian, A Alvin; Park, Woo-Tae; Mallon, Joseph R; Rastegar, Ali J; Pruitt, Beth L

2009-01-01

Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers.

Creating a literature database of low-calorie sweeteners and health studies: evidence mapping.

PubMed

Wang, Ding Ding; Shams-White, Marissa; Bright, Oliver John M; Parrott, J Scott; Chung, Mei

2016-01-05

Evidence mapping is an emerging tool used to systematically identify, organize and summarize the quantity and focus of scientific evidence on a broad topic, but there are currently no methodological standards. Using the topic of low-calorie sweeteners (LCS) and selected health outcomes, we describe the process of creating an evidence-map database and demonstrate several example descriptive analyses using this database. The process of creating an evidence-map database is described in detail. The steps include: developing a comprehensive literature search strategy, establishing study eligibility criteria and a systematic study selection process, extracting data, developing outcome groups with input from expert stakeholders and tabulating data using descriptive analyses. The database was uploaded onto SRDR™ (Systematic Review Data Repository), an open public data repository. Our final LCS evidence-map database included 225 studies, of which 208 were interventional studies and 17 were cohort studies. An example bubble plot was produced to display the evidence-map data and visualize research gaps according to four parameters: comparison types, population baseline health status, outcome groups, and study sample size. This plot indicated a lack of studies assessing appetite and dietary intake related outcomes using LCS with a sugar intake comparison in people with diabetes. Evidence mapping is an important tool for the contextualization of in-depth systematic reviews within broader literature and identifies gaps in the evidence base, which can be used to inform future research. An open evidence-map database has the potential to promote knowledge translation from nutrition science to policy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb-Robertson, Bobbie-Jo M.; Wiberg, Holli K.; Matzke, Melissa M.

In this review, we apply selected imputation strategies to label-free liquid chromatography–mass spectrometry (LC–MS) proteomics datasets to evaluate the accuracy with respect to metrics of variance and classification. We evaluate several commonly used imputation approaches for individual merits and discuss the caveats of each approach with respect to the example LC–MS proteomics data. In general, local similarity-based approaches, such as the regularized expectation maximization and least-squares adaptive algorithms, yield the best overall performances with respect to metrics of accuracy and robustness. However, no single algorithm consistently outperforms the remaining approaches, and in some cases, performing classification without imputation sometimes yieldedmore » the most accurate classification. Thus, because of the complex mechanisms of missing data in proteomics, which also vary from peptide to protein, no individual method is a single solution for imputation. In summary, on the basis of the observations in this review, the goal for imputation in the field of computational proteomics should be to develop new approaches that work generically for this data type and new strategies to guide users in the selection of the best imputation for their dataset and analysis objectives.« less

Diagnostics Strategies with Electrochemical Affinity Biosensors Using Carbon Nanomaterials as Electrode Modifiers

PubMed Central

Campuzano, Susana; Yáñez-Sedeño, Paloma; Pingarrón, José M.

2016-01-01

Early diagnosis is often the key to successful patient treatment and survival. The identification of various disease signaling biomarkers which reliably reflect normal and disease states in humans in biological fluids explain the burgeoning research field in developing new methodologies able to determine the target biomarkers in complex biological samples with the required sensitivity and selectivity and in a simple and rapid way. The unique advantages offered by electrochemical sensors together with the availability of high affinity and specific bioreceptors and their great capabilities in terms of sensitivity and stability imparted by nanostructuring the electrode surface with different carbon nanomaterials have led to the development of new electrochemical biosensing strategies that have flourished as interesting alternatives to conventional methodologies for clinical diagnostics. This paper briefly reviews the advantages of using carbon nanostructures and their hybrid nanocomposites as electrode modifiers to construct efficient electrochemical sensing platforms for diagnosis. The review provides an updated overview of some selected examples involving attractive amplification and biosensing approaches which have been applied to the determination of relevant genetic and protein diagnostics biomarkers. PMID:28035946

Side Streams of Plant Food Processing As a Source of Valuable Compounds: Selected Examples.

PubMed

Schieber, Andreas

2017-02-28

Industrial processing of plant-derived raw materials generates enormous amounts of by-products. On one hand, these by-products constitute a serious disposal issue because they often emerge seasonally and are prone to microbial decay. On the other hand, they are an abundant source of valuable compounds, in particular secondary plant metabolites and cell wall materials, which may be recovered and used to functionalize foods and replace synthetic additives with ingredients of natural origin. This review covers 150 references and presents select studies performed between 2001 and 2016 on the recovery, characterization, and application of valuable constituents from grape pomace, apple pomace, potato peels, tomato pomace, carrot pomace, onion peels, by-products of citrus, mango, banana, and pineapple processing, side streams of olive oil production, and cereal by-products. The criteria used were economic importance, amounts generated, relevance of side streams as a source of valuable compounds, and reviews already published. Despite a plethora of studies carried out on the utilization of side streams, relatively few processes have yet found industrial application.

Primary prevention of psychiatric illness in special populations.

PubMed

Sajatovic, Martha; Sanders, Renata; Alexeenko, Lada; Madhusoodanan, Subramoniam

2010-11-01

Some populations appear to be particularly vulnerable to the development of psychiatric symptomatology related to life events and biologic or social/cultural factors. Such groups include individuals who have experienced traumatic events, military personnel, individuals with serious medical conditions, postpartum women, and immigrants. This study reviews the literature regarding primary prevention of psychiatric disorders in special populations and identifies a variety of universal, selective, and indicated prevention measures aimed at minimizing the psychiatric sequelae in these groups. The authors reviewed the literature regarding the prevention of psychiatric symptoms in trauma/abuse victims, individuals in the military, oncology patients, patients with diabetes, pregnant/postpartum women, and immigrants. The literature on primary prevention of psychiatric illness in the special populations identified is rather limited. Universal prevention may be beneficial in some instances through public awareness campaigns and disaster planning. In other instances, more specific and intensive interventions for individuals at high risk of psychiatric illness may improve outcomes, for example, crisis counseling for those who have experienced severe trauma. Primary prevention of psychiatric illness may be an attainable goal via implementation of specific universal, selected, and indicated primary prevention measures in special populations.

Statistical flaws in design and analysis of fertility treatment studies on cryopreservation raise doubts on the conclusions

PubMed Central

van Gelder, P.H.A.J.M.; Nijs, M.

2011-01-01

Decisions about pharmacotherapy are being taken by medical doctors and authorities based on comparative studies on the use of medications. In studies on fertility treatments in particular, the methodological quality is of utmost importance in the application of evidence-based medicine and systematic reviews. Nevertheless, flaws and omissions appear quite regularly in these types of studies. Current study aims to present an overview of some of the typical statistical flaws, illustrated by a number of example studies which have been published in peer reviewed journals. Based on an investigation of eleven studies at random selected on fertility treatments with cryopreservation, it appeared that the methodological quality of these studies often did not fulfil the required statistical criteria. The following statistical flaws were identified: flaws in study design, patient selection, and units of analysis or in the definition of the primary endpoints. Other errors could be found in p-value and power calculations or in critical p-value definitions. Proper interpretation of the results and/or use of these study results in a meta analysis should therefore be conducted with care. PMID:24753877

Statistical flaws in design and analysis of fertility treatment -studies on cryopreservation raise doubts on the conclusions.

PubMed

van Gelder, P H A J M; Nijs, M

2011-01-01

Decisions about pharmacotherapy are being taken by medical doctors and authorities based on comparative studies on the use of medications. In studies on fertility treatments in particular, the methodological quality is of utmost -importance in the application of evidence-based medicine and systematic reviews. Nevertheless, flaws and omissions appear quite regularly in these types of studies. Current study aims to present an overview of some of the typical statistical flaws, illustrated by a number of example studies which have been published in peer reviewed journals. Based on an investigation of eleven studies at random selected on fertility treatments with cryopreservation, it appeared that the methodological quality of these studies often did not fulfil the -required statistical criteria. The following statistical flaws were identified: flaws in study design, patient selection, and units of analysis or in the definition of the primary endpoints. Other errors could be found in p-value and power calculations or in critical p-value definitions. Proper -interpretation of the results and/or use of these study results in a meta analysis should therefore be conducted with care.

Critical appraisal of systematic reviews on the effect of a history of periodontitis on dental implant loss.

PubMed

Faggion, Clovis Mariano; Giannakopoulos, Nikolaos Nikitas

2013-05-01

To perform a systematic critical appraisal of the methodological quality of systematic reviews on the effect of a history of periodontitis on dental implant loss. PubMed, the Cochrane database for systematic reviews, the DARE, Biosis Preview, CINAHL, Web of Science, and LILACS electronic databases were searched on 16th June 2012, independently and in duplicate, for systematic reviews and meta-analyses related to dental implants for patients with and without a history of periodontitis. Manual searching of the reference lists of included papers was also conducted. The methodological quality of these systematic reviews was assessed by use of the AMSTAR and R-AMSTAR checklists. Before quality assessment was initiated, the reviewers were calibrated until they achieved excellent agreement. Sixty-eight papers were initially retrieved. Of these, nine systematic reviews and three meta-analyses were included. Some domains, for example, "characteristics of the included studies" were satisfied in both checklists. In contrast, domains such as "comprehensive literature search" and "assessment of likelihood of publication bias" were rarely met. Much methodological variability was encountered in the selected reviews. To furnish readers with a more comprehensive assessment of the evidence, authors should observe higher standards when conducting and reporting their reviews. © 2013 John Wiley & Sons A/S.

[Rapid assessment of critical quality attributes of Chinese materia medica (II): strategy of NIR assignment].

PubMed

Pei, Yan-Ling; Wu, Zhi-Sheng; Shi, Xin-Yuan; Zhou, Lu-Wei; Qiao, Yan-Jiang

2014-09-01

The present paper firstly reviewed the research progress and main methods of NIR spectral assignment coupled with our research results. Principal component analysis was focused on characteristic signal extraction to reflect spectral differences. Partial least squares method was concerned with variable selection to discover characteristic absorption band. Two-dimensional correlation spectroscopy was mainly adopted for spectral assignment. Autocorrelation peaks were obtained from spectral changes, which were disturbed by external factors, such as concentration, temperature and pressure. Density functional theory was used to calculate energy from substance structure to establish the relationship between molecular energy and spectra change. Based on the above reviewed method, taking a NIR spectral assignment of chlorogenic acid as example, a reliable spectral assignment for critical quality attributes of Chinese materia medica (CMM) was established using deuterium technology and spectral variable selection. The result demonstrated the assignment consistency according to spectral features of different concentrations of chlorogenic acid and variable selection region of online NIR model in extract process. Although spectral assignment was initial using an active pharmaceutical ingredient, it is meaningful to look forward to the futurity of the complex components in CMM. Therefore, it provided methodology for NIR spectral assignment of critical quality attributes in CMM.

In defense of the passive voice in medical writing.

PubMed

Minton, Timothy D

2015-01-01

Few medical journals specifically instruct authors to use the active voice and avoid the passive voice, but advice to that effect is common in the large number of stylebooks and blogs aimed at medical and scientific writers. Such advice typically revolves around arguments that the passive voice is less clear, less direct, and less concise than the active voice, that it conceals the identity of the person(s) performing the action(s) described, that it obscures meaning, that it is pompous, and that the high rate of passive-voice usage in scientific writing is a result of conformity to an established and old-fashioned style of writing. Some of these arguments are valid with respect to specific examples of passive-voice misuse by some medical (and other) writers, but as arguments for avoiding passive-voice use in general, they are seriously flawed. In addition, many of the examples that stylebook writers give of inappropriate use are actually much more appropriate in certain contexts than the active-voice alternatives they provide. In this review, I examine the advice offered by anti-passive writers, along with some of their examples of "inappropriate" use, and argue that the key factor in voice selection is sentence word order as determined by the natural tendency in English for the topic of discourse ("old" information) to take subject position and for "new" information to come later. Authors who submit to this natural tendency will not have to worry much about voice selection, because it will usually be automatic.

STARE-HI – Statement on Reporting of Evaluation Studies in Health Informatics

PubMed Central

Brender, J.; Talmon, J.; de Keizer, N.; Nykänen, P.; Rigby, M.; Ammenwerth, E.

2013-01-01

Summary Background Improving the quality of reporting of evaluation studies in health informatics is an important requirement towards the vision of evidence-based health informatics. The STARE-HI – Statement on Reporting of Evaluation Studies in health informatics, published in 2009, provides guidelines on the elements to be contained in an evaluation study report. Objectives To elaborate on and provide a rationale for the principles of STARE-HI and to guide authors and readers of evaluation studies in health informatics by providing explanatory examples of reporting. Methods A group of methodologists, researchers and editors prepared the present elaboration of the STARE-HI statement and selected examples from the literature. Results The 35 STARE-HI items to be addressed in evaluation papers describing health informatics interventions are discussed one by one and each is extended with examples and elaborations. Conclusion The STARE-HI statement and this elaboration document should be helpful resources to improve reporting of both quantitative and qualitative evaluation studies. Evaluation manuscripts adhering to the principles will enable readers of such papers to better place the studies in a proper context and judge their validity and generalizability, and thus in turn optimize the exploitation of the evidence contained therein. Limitations This paper is based on experiences of a group of editors, reviewers, authors of systematic reviews and readers of the scientific literature. The applicability of the details of these principles has to evolve as a function of their use in practice. PMID:24155788

Endosymbiotic associations within protists

PubMed Central

Nowack, Eva C. M.; Melkonian, Michael

2010-01-01

The establishment of an endosymbiotic relationship typically seems to be driven through complementation of the host's limited metabolic capabilities by the biochemical versatility of the endosymbiont. The most significant examples of endosymbiosis are represented by the endosymbiotic acquisition of plastids and mitochondria, introducing photosynthesis and respiration to eukaryotes. However, there are numerous other endosymbioses that evolved more recently and repeatedly across the tree of life. Recent advances in genome sequencing technology have led to a better understanding of the physiological basis of many endosymbiotic associations. This review focuses on endosymbionts in protists (unicellular eukaryotes). Selected examples illustrate the incorporation of various new biochemical functions, such as photosynthesis, nitrogen fixation and recycling, and methanogenesis, into protist hosts by prokaryotic endosymbionts. Furthermore, photosynthetic eukaryotic endosymbionts display a great diversity of modes of integration into different protist hosts. In conclusion, endosymbiosis seems to represent a general evolutionary strategy of protists to acquire novel biochemical functions and is thus an important source of genetic innovation. PMID:20124339

Support vector machines and generalisation in HEP

NASA Astrophysics Data System (ADS)

Bevan, Adrian; Gamboa Goñi, Rodrigo; Hays, Jon; Stevenson, Tom

2017-10-01

We review the concept of Support Vector Machines (SVMs) and discuss examples of their use in a number of scenarios. Several SVM implementations have been used in HEP and we exemplify this algorithm using the Toolkit for Multivariate Analysis (TMVA) implementation. We discuss examples relevant to HEP including background suppression for H → τ + τ - at the LHC with several different kernel functions. Performance benchmarking leads to the issue of generalisation of hyper-parameter selection. The avoidance of fine tuning (over training or over fitting) in MVA hyper-parameter optimisation, i.e. the ability to ensure generalised performance of an MVA that is independent of the training, validation and test samples, is of utmost importance. We discuss this issue and compare and contrast performance of hold-out and k-fold cross-validation. We have extended the SVM functionality and introduced tools to facilitate cross validation in TMVA and present results based on these improvements.

Design of lightning protection for a full-authority digital engine control

NASA Technical Reports Server (NTRS)

Dargi, M.; Rupke, E.; Wiles, K.

1991-01-01

The steps and procedures are described which are necessary to achieve a successful lightning-protection design for a state-of-the-art Full-Authority Digital Engine Control (FADEC) system. The engine and control systems used as examples are fictional, but the design and verification methods are real. Topics discussed include: applicable airworthiness regulation, selection of equipment transient design and control levels for the engine/airframe and intra-engine segments of the system, the use of cable shields, terminal-protection devices and filter circuits in hardware protection design, and software approaches to minimize upset potential. Shield terminations, grounding, and bonding are also discussed, as are the important elements of certification and test plans, and the role of tests and analyses. Also included are examples of multiple-stroke and multiple-burst testing. A review of design pitfalls and challenges, and status of applicable test standards such as RTCA DO-160, Section 22, are presented.

A “SMART” Design for Building Individualized Treatment Sequences

PubMed Central

Lei, H.; Nahum-Shani, I.; Lynch, K.; Oslin, D.; Murphy, S.A.

2013-01-01

Interventions often involve a sequence of decisions. For example, clinicians frequently adapt the intervention to an individual’s outcomes. Altering the intensity and type of intervention over time is crucial for many reasons, such as to obtain improvement if the individual is not responding or to reduce costs and burden when intensive treatment is no longer necessary. Adaptive interventions utilize individual variables (severity, preferences) to adapt the intervention and then dynamically utilize individual outcomes (response to treatment, adherence) to readapt the intervention. The Sequential Multiple Assignment Randomized Trial (SMART)provides high-quality data that can be used to construct adaptive interventions. We review the SMART and highlight its advantages in constructing and revising adaptive interventions as compared to alternative experimental designs. Selected examples of SMART studies are described and compared. A data analysis method is provided and illustrated using data from the Extending Treatment Effectiveness of Naltrexone SMART study. PMID:22224838

Forensic engineering: applying materials and mechanics principles to the investigation of product failures.

PubMed

Hainsworth, S V; Fitzpatrick, M E

2007-06-01

Forensic engineering is the application of engineering principles or techniques to the investigation of materials, products, structures or components that fail or do not perform as intended. In particular, forensic engineering can involve providing solutions to forensic problems by the application of engineering science. A criminal aspect may be involved in the investigation but often the problems are related to negligence, breach of contract, or providing information needed in the redesign of a product to eliminate future failures. Forensic engineering may include the investigation of the physical causes of accidents or other sources of claims and litigation (for example, patent disputes). It involves the preparation of technical engineering reports, and may require giving testimony and providing advice to assist in the resolution of disputes affecting life or property.This paper reviews the principal methods available for the analysis of failed components and then gives examples of different component failure modes through selected case studies.

Expert panel reviews of research centers: the site visit process.

PubMed

Lawrenz, Frances; Thao, Mao; Johnson, Kelli

2012-08-01

Site visits are used extensively in a variety of settings within the evaluation community. They are especially common in making summative value decisions about the quality and worth of research programs/centers. However, there has been little empirical research and guidance about how to appropriately conduct evaluative site visits of research centers. We review the processes of two site visit examples using an expert panel review: (1) a process to evaluate four university research centers and (2) a process to review a federally sponsored research center. A set of 14 categories describing the expert panel review process was obtained through content analysis and participant observation. Most categories were addressed differently through the two processes highlighting the need for more research about the most effective processes to use within different contexts. Decisions about how to structure site visits appear to depend on the research context, practical considerations, the level at which the review is being conducted and the intended impact of the report. Future research pertaining to the selection of site visitors, the autonomy of the visitors in data collection and report writing, and the amount and type of information provided would be particularly valuable. Copyright © 2012 Elsevier Ltd. All rights reserved.

SH-SY5Y human neuroblastoma cell line: in vitro cell model of dopaminergic neurons in Parkinson's disease.

PubMed

Xie, Hong-rong; Hu, Lin-sen; Li, Guo-yi

2010-04-20

To evaluate the human neuroblastoma SH-SY5Y cell line as an in vitro model of dopaminergic (DAergic) neurons for Parkinson's disease (PD) research and to determine the effect of differentiation on this cell model. The data of this review were selected from the original reports and reviews related to SH-SY5Y cells published in Chinese and foreign journals (Pubmed 1973 to 2009). After searching the literature, 60 articles were selected to address this review. The SH-SY5Y cell line has become a popular cell model for PD research because this cell line posses many characteristics of DAergic neurons. For example, these cells express tyrosine hydroxylase and dopamine-beta-hydroxylase, as well as the dopamine transporter. Moreover, this cell line can be differentiated into a functionally mature neuronal phenotype in the presence of various agents. Upon differentiation, SH-SY5Y cells stop proliferating and a constant cell number is subsequently maintained. However, different differentiating agents induce different neuronal phenotypes and biochemical changes. For example, retinoic acid induces differentiation toward a cholinergic neuronal phenotype and increases the susceptibility of SH-SY5Y cells to neurotoxins and neuroprotective agents, whereas treatment with retinoic acid followed by phorbol ester 12-O-tetradecanoylphorbol-13-acetate results in a DAergic neuronal phenotype and decreases the susceptibility of cells to neurotoxins and neuroprotective agents. Some differentiating agents also alter kinetics of 1-methyl-4-phenyl-pyridinium (MPP(+)) uptake, making SH-SY5Y cells more similar to primary mesencephalic neurons. Differentiated and undifferentiated SH-SY5Y cells have been widely used as a cell model of DAergic neurons for PD research. Some differentiating agents afford SH-SY5Y cells with more potential for studying neurotoxicity and neuroprotection and are thus more relevant to experimental PD research.

Computational Modelling of Materials for Wind Turbine Blades: Selected DTU Wind Energy Activities.

PubMed

Mikkelsen, Lars Pilgaard; Mishnaevsky, Leon

2017-11-08

Computational and analytical studies of degradation of wind turbine blade materials at the macro-, micro-, and nanoscale carried out by the modelling team of the Section Composites and Materials Mechanics, Department of Wind Energy, DTU, are reviewed. Examples of the analysis of the microstructural effects on the strength and fatigue life of composites are shown. Computational studies of degradation mechanisms of wind blade composites under tensile and compressive loading are presented. The effect of hybrid and nanoengineered structures on the performance of the composite was studied in computational experiments as well.

The role of military medicine in military civic action.

PubMed

Luz, G A; De Pauw, J W; Gaydos, J C; Hooper, R R; Legters, L J

1993-06-01

We are moving into an era when U.S. military forces will be called upon frequently to perform military civic action (MCA) projects. Such projects, have been used successfully and unsuccessfully, primarily in the areas of medicine and engineering, to enhance the standing of military forces with indigenous populations. However, the available criteria for planning and assessing MCA projects are not widely known. These related and overlapping criteria are supported by facts, interpretative data, anecdotes, and common sense, but none can be considered absolute. Selected criteria are defined, reviewed, and illustrated with examples of past successes and failures.

Typical examples of classical novae

NASA Technical Reports Server (NTRS)

Hack, Margherita; Selvelli, Pierluigi; Bianchini, Antonio; Duerbeck, Hilmar W.

1993-01-01

Because of the very complicated individualistic behavior of each nova, we think it necessary to review the observations of a few well-observed individuals. We have selected a few objects of different speed classes, which have been extensively observed. They are: V1500 Cygni 1975, a very fast nova; V603 Aql 1918, fast nova; CP Pup 1942, fast nova; GK Per 1901, fast nova; V 1668 Cyg 1979, moderately fast nova; FH Ser 1970, slow nova; DQ Her 1934, slow nova; T Aur 1891, slow nova; RR Pic 1925, slow nova; and HR Del 1967, very slow nova.

Time-lapse imaging of neural development: zebrafish lead the way into the fourth dimension.

PubMed

Rieger, Sandra; Wang, Fang; Sagasti, Alvaro

2011-07-01

Time-lapse imaging is often the only way to appreciate fully the many dynamic cell movements critical to neural development. Zebrafish possess many advantages that make them the best vertebrate model organism for live imaging of dynamic development events. This review will discuss technical considerations of time-lapse imaging experiments in zebrafish, describe selected examples of imaging studies in zebrafish that revealed new features or principles of neural development, and consider the promise and challenges of future time-lapse studies of neural development in zebrafish embryos and adults. Copyright © 2011 Wiley-Liss, Inc.

Introduction to molecular topology: basic concepts and application to drug design.

PubMed

Gálvez, Jorge; Gálvez-Llompart, María; García-Domenech, Ramón

2012-09-01

In this review it is dealt the use of molecular topology (MT) in the selection and design of new drugs. After an introduction of the actual methods used for drug design, the basic concepts of MT are defined, including examples of calculation of topological indices, which are numerical descriptors of molecular structures. The goal is making this calculation familiar to the potential students and allowing a straightforward comprehension of the topic. Finally, the achievements obtained in this field are detailed, so that the reader can figure out the great interest of this approach.

Stereoselective heterocycle synthesis through oxidative carbon-hydrogen bond activation.

PubMed

Liu, Lei; Floreancig, Paul E

2010-01-01

Heterocycles are ubiquitous structures in both drugs and natural products, and efficient methods for their construction are being pursued constantly. Carbon-hydrogen bond activation offers numerous advantages for the synthesis of heterocycles with respect to minimizing the length of synthetic routes and reducing waste. As interest in chiral medicinal leads increases, stereoselective methods for heterocycle synthesis must be developed. The use of carbon-hydrogen bond activation reactions for stereoselective heterocycle synthesis has produced a range of creative transformations that provide a wide array of structural motifs, selected examples of which are described in this review.

Technology transfer in New York City - The NASA/NYC Applications Project.

NASA Technical Reports Server (NTRS)

Karen, A.; Orrick, D.; Anuskiewicz, T.

1973-01-01

New York City faces many varied and complex problems ranging from truck hijacking to graffiti. In answer to a request from NYC officials NASA is sponsoring the efforts of a project aimed at applying aerospace-derived solutions to a series of city technical problems. An immediate result has been a pilot experiment to improve security in the City's schools. Other problem areas for NASA review have been selected from the Fire, Police and Air Resources Departments. The Project offers a significant example of a viable approach to the crucial process of bridging the communications gap between urban officials and technologists.

Tumor microenvironment: Sanctuary of the devil.

PubMed

Hui, Lanlan; Chen, Ye

2015-11-01

Tumor cells constantly interact with the surrounding microenvironment. Increasing evidence indicates that targeting the tumor microenvironment could complement traditional treatment and improve therapeutic outcomes for these malignancies. In this paper, we review new insights into the tumor microenvironment, and summarize selected examples of the cross-talk between tumor cells and their microenvironment, which have enhanced our understanding of pathophysiology of the microenvironment. We believe that this rapidly moving field promises many more to come, and they will guide the rational design of combinational therapies for success in cancer eradication. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Beyond the bulk: disclosing the life of single microbial cells

PubMed Central

Rosenthal, Katrin; Oehling, Verena

2017-01-01

Abstract Microbial single cell analysis has led to discoveries that are beyond what can be resolved with population-based studies. It provides a pristine view of the mechanisms that organize cellular physiology, unbiased by population heterogeneity or uncontrollable environmental impacts. A holistic description of cellular functions at the single cell level requires analytical concepts beyond the miniaturization of existing technologies, defined but uncontrolled by the biological system itself. This review provides an overview of the latest advances in single cell technologies and demonstrates their potential. Opportunities and limitations of single cell microbiology are discussed using selected application-related examples. PMID:29029257

Typical examples of classical novae

NASA Astrophysics Data System (ADS)

Hack, Margherita; Selvelli, Pierluigi; Bianchini, Antonio; Duerbeck, Hilmar W.

1993-09-01

Because of the very complicated individualistic behavior of each nova, we think it necessary to review the observations of a few well-observed individuals. We have selected a few objects of different speed classes, which have been extensively observed. They are: V1500 Cygni 1975, a very fast nova; V603 Aql 1918, fast nova; CP Pup 1942, fast nova; GK Per 1901, fast nova; V 1668 Cyg 1979, moderately fast nova; FH Ser 1970, slow nova; DQ Her 1934, slow nova; T Aur 1891, slow nova; RR Pic 1925, slow nova; and HR Del 1967, very slow nova.

Computational Modelling of Materials for Wind Turbine Blades: Selected DTU Wind Energy Activities

PubMed Central

2017-01-01

Computational and analytical studies of degradation of wind turbine blade materials at the macro-, micro-, and nanoscale carried out by the modelling team of the Section Composites and Materials Mechanics, Department of Wind Energy, DTU, are reviewed. Examples of the analysis of the microstructural effects on the strength and fatigue life of composites are shown. Computational studies of degradation mechanisms of wind blade composites under tensile and compressive loading are presented. The effect of hybrid and nanoengineered structures on the performance of the composite was studied in computational experiments as well. PMID:29117138

Self-immolation: cause and culture.

PubMed

Romm, Sharon; Combs, Heidi; Klein, Matthew B

2008-01-01

Accounts of self-inflicted death by fire are numerous and are found from antiquity to present times. We review selected examples of self-immolation from historical record, in mythology and as part of religious and cultural tradition. We discuss the use of self-immolation as a literary device in the arts including fiction, opera, movies, and song. We offer motives for this horrifying act and discuss how it has been used as a form of protest for political reasons or for individual maltreatment or as a means to end intense personal suffering. Finally, we explore what setting oneself alight may represent from a psychodynamic perspective.

10 CFR 170.21 - Schedule of fees for production and utilization facilities, review of standard referenced design...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., Certification Full cost. Amendment, Renewal, Other Approvals Full cost. C. Test Facility/Research Reactor... of components requiring Commission and Executive Branch review, for example, actions under 10 CFR 110... export of reactor and other components requiring Executive Branch review, for example, those actions...

Generic Example Proving Criteria for All

ERIC Educational Resources Information Center

Yopp, David; Ely, Rob; Johnson­-Leung, Jennifer

2015-01-01

We review literature that discusses generic example proving and highlight ambiguities that pervade our research community's discourse about generic example arguments. We distinguish between pedagogical advice for choosing good examples that can serve as generic examples when teaching and advice for developing generic example arguments. We provide…

Directed evolution: tailoring biocatalysts for industrial applications.

PubMed

Kumar, Ashwani; Singh, Suren

2013-12-01

Current challenges and promises of white biotechnology encourage protein engineers to use a directed evolution approach to generate novel and useful biocatalysts for various sets of applications. Different methods of enzyme engineering have been used in the past in an attempt to produce enzymes with improved functions and properties. Recent advancement in the field of random mutagenesis, screening, selection and computational design increased the versatility and the rapid development of enzymes under strong selection pressure with directed evolution experiments. Techniques of directed evolution improve enzymes fitness without understanding them in great detail and clearly demonstrate its future role in adapting enzymes for use in industry. Despite significant advances to date regarding biocatalyst improvement, there still remains a need to improve mutagenesis strategies and development of easy screening and selection tools without significant human intervention. This review covers fundamental and major development of directed evolution techniques, and highlights the advances in mutagenesis, screening and selection methods with examples of enzymes developed by using these approaches. Several commonly used methods for creating molecular diversity with their advantages and disadvantages including some recently used strategies are also discussed.

Genomic data as the “hitchhiker's guide” to cattle adaptation: tracking the milestones of past selection in the bovine genome

PubMed Central

Utsunomiya, Yuri T.; Pérez O'Brien, Ana M.; Sonstegard, Tad S.; Sölkner, Johann; Garcia, José F.

2015-01-01

The bovine species have witnessed and played a major role in the drastic socio-economical changes that shaped our culture over the last 10,000 years. During this journey, cattle “hitchhiked” on human development and colonized the world, facing strong selective pressures such as dramatic environmental changes and disease challenge. Consequently, hundreds of specialized cattle breeds emerged and spread around the globe, making up a rich spectrum of genomic resources. Their DNA still carry the scars left from adapting to this wide range of conditions, and we are now empowered with data and analytical tools to track the milestones of past selection in their genomes. In this review paper, we provide a summary of the reconstructed demographic events that shaped cattle diversity, offer a critical synthesis of popular methodologies applied to the search for signatures of selection (SS) in genomic data, and give examples of recent SS studies in cattle. Then, we outline the potential and challenges of the application of SS analysis in cattle, and discuss the future directions in this field. PMID:25713583

[The methods within the evaluation of disease management programmes in control-group designs using the example of diabetes mellitus - a systematic literature review].

PubMed

Drabik, A; Sawicki, P T; Müller, D; Passon, A; Stock, S

2012-08-01

Disease management programmes (DMPs) were implemented in Germany in 2002. Their evaluation is required by law. Beyond the mandatory evaluation, a growing number of published studies evaluate the DMP for diabetes mellitus type 2 in a control-group design. As patients opt into the programme on a voluntary basis it is necessary to adjust the inherent selection bias between groups. The aim of this study is to review published studies which evaluate the diabetes DMP using a control-group design with respect to the methods used. A systematic literature review of electronic databases (PUBMED, Cochrane Library, EMBASE, MEDPILOT) and a hand search of reference lists of the relevant publications was conducted to identify studies evaluating the DMP diabetes mellitus in a control-group design. 8 studies were included in the systematic literature review. 4 studies gathered retrospective claims data from sickness funds, one from physician's records, one study used prospective data from ambulatory care, and 2 studies were based on one patient survey. Methods used for adjustment of selection bias included exact matching, matching using propensity score methods, age-adjusted and sex-separated analysis, and adjustment in a regression model/analysis of covariance. One study did not apply adjustment methods. The intervention period ranged from 1 day to 4 years. Considered outcomes of studies (surrogate parameter, diabetes complications, mortality, quality of life, and claim data) depended on the database. In the evaluation of the DMP diabetes mellitus based on a control-group design neither the database nor the methods used for selection bias adjustment were consistent in the available studies. Effectiveness of DMPs cannot be judged based on this review due to heterogeneity of study designs. To allow for a comprehensive programme evaluation standardised minimum requirements for the evaluation of DMPs in the control group design are required. © Georg Thieme Verlag KG Stuttgart · New York.

Climate change and evolution: disentangling environmental and genetic responses.

PubMed

Gienapp, P; Teplitsky, C; Alho, J S; Mills, J A; Merilä, J

2008-01-01

Rapid climate change is likely to impose strong selection pressures on traits important for fitness, and therefore, microevolution in response to climate-mediated selection is potentially an important mechanism mitigating negative consequences of climate change. We reviewed the empirical evidence for recent microevolutionary responses to climate change in longitudinal studies emphasizing the following three perspectives emerging from the published data. First, although signatures of climate change are clearly visible in many ecological processes, similar examples of microevolutionary responses in literature are in fact very rare. Second, the quality of evidence for microevolutionary responses to climate change is far from satisfactory as the documented responses are often - if not typically - based on nongenetic data. We reinforce the view that it is as important to make the distinction between genetic (evolutionary) and phenotypic (includes a nongenetic, plastic component) responses clear, as it is to understand the relative roles of plasticity and genetics in adaptation to climate change. Third, in order to illustrate the difficulties and their potential ubiquity in detection of microevolution in response to natural selection, we reviewed the quantitative genetic studies on microevolutionary responses to natural selection in the context of long-term studies of vertebrates. The available evidence points to the overall conclusion that many responses perceived as adaptations to changing environmental conditions could be environmentally induced plastic responses rather than microevolutionary adaptations. Hence, clear-cut evidence indicating a significant role for evolutionary adaptation to ongoing climate warming is conspicuously scarce.

Using positive youth development constructs to design a money management curriculum for junior secondary school students in Hong Kong.

PubMed

Lau, Patrick S Y; Lam, C M; Law, Ben M F; Poon, Y H

2011-01-01

This paper aims to discuss the relationships between the selected positive youth development constructs and the enhancement of Hong Kong junior secondary school students' money management skills, values, and attitudes. Various issues of money management of adolescents are reviewed. These issues include the need for money management programs for adolescents, the content and coverage of an appropriate money management program, and its relationships with the selected positive youth development constructs. The curriculum units for secondary 3 students are taken as examples to illustrate the design of the program. It is believed that promoting cognitive competence, self-efficacy, and spirituality could be an effective way to enhance students' money management skills, values, and attitudes, thus preparing them better for facing the finance-related issues in life.

Polymorph selection: the role of nucleation, crystal growth and molecular modeling.

PubMed

Erdemir, Deniz; Lee, Alfred Y; Myerson, Allan S

2007-11-01

Solution crystallization is an important separation and purification process used in the chemical, pharmaceutical and food industries. The quality of a crystalline product is generally judged by four main criteria: purity, crystal habit, particle size and solid form. Consistent production of the desired polymorph is crucial as the unanticipated emergence of a different crystal form may have severe consequences. Thus, the selection of a solid-state form for a crystalline product is vital and is ultimately based on knowledge of the properties of the other polymorphs. This review discusses the role of nucleation, crystal growth and molecular modeling on polymorphism in molecular crystals. Examples are presented demonstrating how the first two factors can govern the appearance of a particular crystalline form, and how the latter factor can be used as a tool for understanding polymorphism.

Adapting the balanced scorecard for mental health and addictions: an inpatient example.

PubMed

Lin, Elizabeth; Durbin, Janet

2008-05-01

The Balanced Scorecard (BSC) is a performance-monitoring framework that originated in the business sector but has more recently been applied to health services. The province of Ontario is using the BSC approach to monitor quality of inpatient care in five service areas. Feasibility of the scorecard framework for each area has been assessed using a standard approach. This paper reports results of the feasibility study for the mental health sector, focusing on three issues: framework relevance, underlying strategic goals and indicator selection. Based on a literature review and extensive stakeholder input, the BSC quadrant structure was recommended with some modifications, and indicators were selected that aligned with provincial mental health reform policy goals. The mental health report has completed two cycles of reporting, and has received good support from the field. Copyright © 2008 Longwoods Publishing.

Using Positive Youth Development Constructs to Design a Money Management Curriculum for Junior Secondary School Students in Hong Kong

PubMed Central

Lau, Patrick S. Y.; Lam, C. M.; Law, Ben M. F.; Poon, Y. H.

2011-01-01

This paper aims to discuss the relationships between the selected positive youth development constructs and the enhancement of Hong Kong junior secondary school students' money management skills, values, and attitudes. Various issues of money management of adolescents are reviewed. These issues include the need for money management programs for adolescents, the content and coverage of an appropriate money management program, and its relationships with the selected positive youth development constructs. The curriculum units for secondary 3 students are taken as examples to illustrate the design of the program. It is believed that promoting cognitive competence, self-efficacy, and spirituality could be an effective way to enhance students' money management skills, values, and attitudes, thus preparing them better for facing the finance-related issues in life. PMID:22125469

Candidate immune biomarkers for radioimmunotherapy.

PubMed

Levy, Antonin; Nigro, Giulia; Sansonetti, Philippe J; Deutsch, Eric

2017-08-01

Newly available immune checkpoint blockers (ICBs), capable to revert tumor immune tolerance, are revolutionizing the anticancer armamentarium. Recent evidence also established that ionizing radiation (IR) could produce antitumor immune responses, and may as well synergize with ICBs. Multiple radioimmunotherapy combinations are thenceforth currently assessed in early clinical trials. Past examples have highlighted the need for treatment personalization, and there is an unmet need to decipher immunological biomarkers that could allow selecting patients who could benefit from these promising but expensive associations. Recent studies have identified potential predictive and prognostic immune assays at the cellular (tumor microenvironment composition), genomic (mutational/neoantigen load), and peripheral blood levels. Within this review, we collected the available evidence regarding potential personalized immune biomarker-directed radiation therapy strategies that might be used for patient selection in the era of radioimmunotherapy. Copyright © 2017. Published by Elsevier B.V.

A practical guide to assessing clinical decision-making skills using the key features approach.

PubMed

Farmer, Elizabeth A; Page, Gordon

2005-12-01

This paper in the series on professional assessment provides a practical guide to writing key features problems (KFPs). Key features problems test clinical decision-making skills in written or computer-based formats. They are based on the concept of critical steps or 'key features' in decision making and represent an advance on the older, less reliable patient management problem (PMP) formats. The practical steps in writing these problems are discussed and illustrated by examples. Steps include assembling problem-writing groups, selecting a suitable clinical scenario or problem and defining its key features, writing the questions, selecting question response formats, preparing scoring keys, reviewing item quality and item banking. The KFP format provides educators with a flexible approach to testing clinical decision-making skills with demonstrated validity and reliability when constructed according to the guidelines provided.

Minimal access surgery for repair of congenital diaphragmatic hernia: is it advantageous?--An open review.

PubMed

Vijfhuize, S; Deden, A C; Costerus, S A; Sloots, C E J; Wijnen, R M H

2012-10-01

Congenital diaphragmatic hernia (CDH) is a congenital life-threatening condition requiring surgical repair in the neonatal period. Minimal access surgery (MAS) is gaining ground on the classical open approach by laparotomy or thoracotomy as it minimizes damage to the abdominal or thoracic wall. Using an open review of the literature, we aimed to determine whether MAS is safe and effective in treating CDH. Furthermore, we provide selection criteria for the optimal surgical approach, laid down in a decision algorithm. An online search of MEDLINE was performed (May 2012), followed by a citations search. All study types except case reports describing open and/or MAS repair of Bochdalek CDH were eligible. Primary outcome data, for example, surgical complications and mortality, were recorded, as well as secondary outcome measures, for example, operative time, duration of postoperative ventilation, tolerance of enteral nutrition, and total length of stay (LOS) in hospital. Analysis was performed in accordance with the standards of the Cochrane Handbook for Systematic Reviews of Interventions. We identified 15 relevant studies, 5 of them describing MAS only and 10 comparing MAS to open repair of CDH. Numbers of included patients and selection criteria for MAS varied widely. Most studies have methodological limitations, such as the use of retrospective data or historical control groups. ECMO treatment and patch use were more frequent in the open repair group (both p < 0.0001). Recurrence risk seemed to be increased in the MAS group. The need for conversion in MAS series ranged widely, from 3.4 to 75.0%. The risk of general surgical complications did not vary between groups. Mortality seemed to be less in the MAS group. Operative time seemed to be longer in the MAS group. Duration of postoperative ventilation and total LOS appeared to be reduced in this group and patients returned quicker to enteral nutrition. We demonstrate that MAS for diaphragmatic hernia appears to be safe in terms of complications and mortality. Besides, it is associated with faster postoperative recovery. Growing experience with this technique is expected to lower the recurrence risk and to shorten the operative time. These findings should be interpreted cautiously because of methodological limitations of the studies included. Selection criteria used in various studies are associated with an important risk of selection bias. Nonetheless, these criteria can be used to identify patients who will benefit most from MAS. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Molecularly Imprinted Polymers for Ochratoxin A Extraction and Analysis

PubMed Central

Yu, Jorn C. C.; Lai, Edward P. C.

2010-01-01

Molecularly imprinted polymers (MIPs) are considered as polymeric materials that mimic the functionality of antibodies. MIPs have been utilized for a wide variety of applications in chromatography, solid phase extraction, immunoassays, and sensor recognition. In this article, recent advances of MIPs for the extraction and analysis of ochratoxins are discussed. Selection of functional monomers to bind ochratoxin A (OTA) with high affinities, optimization of extraction procedures, and limitations of MIPs are compared from different reports. The most relevant examples in the literature are described to clearly show how useful these materials are. Strategies on MIP preparation and schemes of analytical methods are also reviewed in order to suggest the next step that would make better use of MIPs in the field of ochratoxin research. The review ends by outlining the remaining issues and impediments. PMID:22069649

Practical aspects of instrumentation system installation, volume 13

NASA Technical Reports Server (NTRS)

Borek, R. W.; Pool, A. (Editor); Sanderson, K. C. (Editor)

1981-01-01

A review of factors influencing installation of aircraft flight test instrumentation is presented. Requirements, including such factors as environment, reliability, maintainability, and system safety are discussed. The assessment of the mission profile is followed by an overview of electrical and mechanical installation factors with emphasis on shock/vibration isolation systems and standardization of the electric wiring installation, two factors often overlooked by instrumentation engineers. A discussion of installation hardware reviews the performance capabilities of wiring, connectors, fuses and circuit breakers, and a guide to proper selections is provided. The discussion of the installation is primarily concerned with the electrical wire routing, shield terminations and grounding. Also inclued are some examples of installation mistakes that could affect system accuracy. System verification procedures and special considerations such as sneak circuits, pyrotechnics, aircraft antenna patterns, and lightning strikes are discussed.

Review: Semiconductor Piezoresistance for Microsystems

PubMed Central

Barlian, A. Alvin; Park, Woo-Tae; Mallon, Joseph R.; Rastegar, Ali J.; Pruitt, Beth L.

2010-01-01

Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers. PMID:20198118

Vision and Control for UAVs: A Survey of General Methods and of Inexpensive Platforms for Infrastructure Inspection

PubMed Central

Máthé, Koppány; Buşoniu, Lucian

2015-01-01

Unmanned aerial vehicles (UAVs) have gained significant attention in recent years. Low-cost platforms using inexpensive sensor payloads have been shown to provide satisfactory flight and navigation capabilities. In this report, we survey vision and control methods that can be applied to low-cost UAVs, and we list some popular inexpensive platforms and application fields where they are useful. We also highlight the sensor suites used where this information is available. We overview, among others, feature detection and tracking, optical flow and visual servoing, low-level stabilization and high-level planning methods. We then list popular low-cost UAVs, selecting mainly quadrotors. We discuss applications, restricting our focus to the field of infrastructure inspection. Finally, as an example, we formulate two use-cases for railway inspection, a less explored application field, and illustrate the usage of the vision and control techniques reviewed by selecting appropriate ones to tackle these use-cases. To select vision methods, we run a thorough set of experimental evaluations. PMID:26121608

Systematic literature reviews and meta-analyses: part 6 of a series on evaluation of scientific publications.

PubMed

Ressing, Meike; Blettner, Maria; Klug, Stefanie J

2009-07-01

Because of the rising number of scientific publications, it is important to have a means of jointly summarizing and assessing different studies on a single topic. Systematic literature reviews, meta-analyses of published data, and meta-analyses of individual data (pooled reanalyses) are now being published with increasing frequency. We here describe the essential features of these methods and discuss their strengths and weaknesses. This article is based on a selective literature search. The different types of review and meta-analysis are described, the methods used in each are outlined so that they can be evaluated, and a checklist is given for the assessment of reviews and meta-analyses of scientific articles. Systematic literature reviews provide an overview of the state of research on a given topic and enable an assessment of the quality of individual studies. They also allow the results of different studies to be evaluated together when these are inconsistent. Meta-analyses additionally allow calculation of pooled estimates of an effect. The different types of review and meta-analysis are discussed with examples from the literature on one particular topic. Systematic literature reviews and meta-analyses enable the research findings and treatment effects obtained in different individual studies to be summed up and evaluated.

[Reconsidering children's dreams. A critical review of methods and results in developmental dream research from Freud to contemporary works].

PubMed

Sándor, Piroska; Bódizs, Róbert

2014-01-01

Examining children's dream development is a significant challenge for researchers. Results from studies on children's dreaming may enlighten us on the nature and role of dreaming as well as broaden our knowledge of consciousness and cognitive development. This review summarizes the main questions and historical progress in developmental dream research, with the aim of shedding light on the advantages, disadvantages and effects of different settings and methods on research outcomes. A typical example would be the dreams of 3 to 5 year-olds: they are simple and static, with a relative absence of emotions and active self participation according to laboratory studies; studies using different methodology however found them to be vivid, rich in emotions, with the self as an active participant. Questions about the validity of different methods arise, and are considered within this review. Given that methodological differences can result in highly divergent outcomes, it is strongly recommended for future research to select methodology and treat results more carefully.

Porous Inorganic Drug Delivery Systems-a Review.

PubMed

Sayed, E; Haj-Ahmad, R; Ruparelia, K; Arshad, M S; Chang, M-W; Ahmad, Z

2017-07-01

Innovative methods and materials have been developed to overcome limitations associated with current drug delivery systems. Significant developments have led to the use of a variety of materials (as excipients) such as inorganic and metallic structures, marking a transition from conventional polymers. Inorganic materials, especially those possessing significant porosity, are emerging as good candidates for the delivery of a range of drugs (antibiotics, anticancer and anti-inflammatories), providing several advantages in formulation and engineering (encapsulation of drug in amorphous form, controlled delivery and improved targeting). This review focuses on key selected developments in porous drug delivery systems. The review provides a short broad overview of porous polymeric materials for drug delivery before focusing on porous inorganic materials (e.g. Santa Barbara Amorphous (SBA) and Mobil Composition of Matter (MCM)) and their utilisation in drug dosage form development. Methods for their preparation and drug loading thereafter are detailed. Several examples of porous inorganic materials, drugs used and outcomes are discussed providing the reader with an understanding of advances in the field and realistic opportunities.

Additive manufacturing of hybrid circuits

DOE PAGES

Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; ...

2016-03-26

There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

Intrasexual competition in females: evidence for sexual selection?

PubMed

Rosvall, Kimberly A

2011-11-01

In spite of recent interest in sexual selection in females, debate exists over whether traits that influence female-female competition are sexually selected. This review uses female-female aggressive behavior as a model behavioral trait for understanding the evolutionary mechanisms promoting intrasexual competition, focusing especially on sexual selection. I employ a broad definition of sexual selection, whereby traits that influence competition for mates are sexually selected, whereas those that directly influence fecundity or offspring survival are naturally selected. Drawing examples from across animal taxa, including humans, I examine 4 predictions about female intrasexual competition based on the abundance of resources, the availability of males, and the direct or indirect benefits those males provide. These patterns reveal a key sex difference in sexual selection: Although females may compete for the number of mates, they appear to compete more so for access to high-quality mates that provide direct and indirect (genetic) benefits. As is the case in males, intrasexual selection in females also includes competition for essential resources required for access to mates. If mate quality affects the magnitude of mating success, then restricting sexual selection to competition for quantity of mates may ignore important components of fitness in females and underestimate the role of sexual selection in shaping female phenotype. In the future, understanding sex differences in sexual selection will require further exploration of the extent of mutual intrasexual competition and the incorporation of quality of mating success into the study of sexual selection in both sexes.

Intrasexual competition in females: evidence for sexual selection?

PubMed Central

2011-01-01

In spite of recent interest in sexual selection in females, debate exists over whether traits that influence female–female competition are sexually selected. This review uses female–female aggressive behavior as a model behavioral trait for understanding the evolutionary mechanisms promoting intrasexual competition, focusing especially on sexual selection. I employ a broad definition of sexual selection, whereby traits that influence competition for mates are sexually selected, whereas those that directly influence fecundity or offspring survival are naturally selected. Drawing examples from across animal taxa, including humans, I examine 4 predictions about female intrasexual competition based on the abundance of resources, the availability of males, and the direct or indirect benefits those males provide. These patterns reveal a key sex difference in sexual selection: Although females may compete for the number of mates, they appear to compete more so for access to high-quality mates that provide direct and indirect (genetic) benefits. As is the case in males, intrasexual selection in females also includes competition for essential resources required for access to mates. If mate quality affects the magnitude of mating success, then restricting sexual selection to competition for quantity of mates may ignore important components of fitness in females and underestimate the role of sexual selection in shaping female phenotype. In the future, understanding sex differences in sexual selection will require further exploration of the extent of mutual intrasexual competition and the incorporation of quality of mating success into the study of sexual selection in both sexes. PMID:22479137

From concepts, theory, and evidence of heterogeneity of treatment effects to methodological approaches: a primer.

PubMed

Willke, Richard J; Zheng, Zhiyuan; Subedi, Prasun; Althin, Rikard; Mullins, C Daniel

2012-12-13

Implicit in the growing interest in patient-centered outcomes research is a growing need for better evidence regarding how responses to a given intervention or treatment may vary across patients, referred to as heterogeneity of treatment effect (HTE). A variety of methods are available for exploring HTE, each associated with unique strengths and limitations. This paper reviews a selected set of methodological approaches to understanding HTE, focusing largely but not exclusively on their uses with randomized trial data. It is oriented for the "intermediate" outcomes researcher, who may already be familiar with some methods, but would value a systematic overview of both more and less familiar methods with attention to when and why they may be used. Drawing from the biomedical, statistical, epidemiological and econometrics literature, we describe the steps involved in choosing an HTE approach, focusing on whether the intent of the analysis is for exploratory, initial testing, or confirmatory testing purposes. We also map HTE methodological approaches to data considerations as well as the strengths and limitations of each approach. Methods reviewed include formal subgroup analysis, meta-analysis and meta-regression, various types of predictive risk modeling including classification and regression tree analysis, series of n-of-1 trials, latent growth and growth mixture models, quantile regression, and selected non-parametric methods. In addition to an overview of each HTE method, examples and references are provided for further reading.By guiding the selection of the methods and analysis, this review is meant to better enable outcomes researchers to understand and explore aspects of HTE in the context of patient-centered outcomes research.

Integrating genomic selection into dairy cattle breeding programmes: a review.

PubMed

Bouquet, A; Juga, J

2013-05-01

Extensive genetic progress has been achieved in dairy cattle populations on many traits of economic importance because of efficient breeding programmes. Success of these programmes has relied on progeny testing of the best young males to accurately assess their genetic merit and hence their potential for breeding. Over the last few years, the integration of dense genomic information into statistical tools used to make selection decisions, commonly referred to as genomic selection, has enabled gains in predicting accuracy of breeding values for young animals without own performance. The possibility to select animals at an early stage allows defining new breeding strategies aimed at boosting genetic progress while reducing costs. The first objective of this article was to review methods used to model and optimize breeding schemes integrating genomic selection and to discuss their relative advantages and limitations. The second objective was to summarize the main results and perspectives on the use of genomic selection in practical breeding schemes, on the basis of the example of dairy cattle populations. Two main designs of breeding programmes integrating genomic selection were studied in dairy cattle. Genomic selection can be used either for pre-selecting males to be progeny tested or for selecting males to be used as active sires in the population. The first option produces moderate genetic gains without changing the structure of breeding programmes. The second option leads to large genetic gains, up to double those of conventional schemes because of a major reduction in the mean generation interval, but it requires greater changes in breeding programme structure. The literature suggests that genomic selection becomes more attractive when it is coupled with embryo transfer technologies to further increase selection intensity on the dam-to-sire pathway. The use of genomic information also offers new opportunities to improve preservation of genetic variation. However, recent simulation studies have shown that putting constraints on genomic inbreeding rates for defining optimal contributions of breeding animals could significantly reduce achievable genetic gain. Finally, the article summarizes the potential of genomic selection to include new traits in the breeding goal to meet societal demands regarding animal health and environmental efficiency in animal production.

Text mining for search term development in systematic reviewing: A discussion of some methods and challenges.

PubMed

Stansfield, Claire; O'Mara-Eves, Alison; Thomas, James

2017-09-01

Using text mining to aid the development of database search strings for topics described by diverse terminology has potential benefits for systematic reviews; however, methods and tools for accomplishing this are poorly covered in the research methods literature. We briefly review the literature on applications of text mining for search term development for systematic reviewing. We found that the tools can be used in 5 overarching ways: improving the precision of searches; identifying search terms to improve search sensitivity; aiding the translation of search strategies across databases; searching and screening within an integrated system; and developing objectively derived search strategies. Using a case study and selected examples, we then reflect on the utility of certain technologies (term frequency-inverse document frequency and Termine, term frequency, and clustering) in improving the precision and sensitivity of searches. Challenges in using these tools are discussed. The utility of these tools is influenced by the different capabilities of the tools, the way the tools are used, and the text that is analysed. Increased awareness of how the tools perform facilitates the further development of methods for their use in systematic reviews. Copyright © 2017 John Wiley & Sons, Ltd.

Genetic compatibility, mate choice and patterns of parentage: invited review.

PubMed

Tregenza, T; Wedell, N

2000-08-01

There is growing interest in the possibility that genetic compatibility may drive mate choice, including gamete choice, particularly from the perspective of understanding why females frequently mate with more than one male. Mate choice for compatibility differs from other forms of choice for genetic benefits (such as 'good genes') because individuals are expected to differ in their mate preferences, changing the evolutionary dynamics of sexual selection. Recent experiments designed to investigate genetic benefits of polyandry suggest that mate choice on the basis of genetic compatibility may be widespread. However, in most systems the mechanisms responsible for variation in compatibility are unknown. We review potential sources of variation in genetic compatibility and whether there is any evidence for mate choice driven by these factors. Selfish genetic elements appear to have the potential to drive mate compatibility mate choice, though as yet there is only one convincing example. There is abundant evidence for assortative mating between populations in hybrid zones, but very few examples where this is clearly a result of selection against mating with genetically less compatible individuals. There are also numerous cases of inbreeding avoidance, but little evidence that mate choice or differential fertilization success driven by genetic compatibility occurs between unrelated individuals. The exceptions to this are a handful of situations where both the alleles causing incompatibility and the alleles involved in mate choice are located in a chromosome region where recombination is suppressed. As yet there are only a few potential sources of genetic compatibility which have clearly been shown to drive mate choice. This may reflect limitations in the potential for the evolution of mate choice for genetic compatibility within populations, although the most promising sources of such incompatibilities have received relatively little research.

Context-Aware Reviewer Assignment for Trust Enhanced Peer Review

PubMed Central

Li, Lei; Wang, Yan; Liu, Guanfeng; Wang, Meng; Wu, Xindong

2015-01-01

Reviewer assignment is critical to peer review systems, such as peer-reviewed research conferences or peer-reviewed funding applications, and its effectiveness is a deep concern of all academics. However, there are some problems in existing peer review systems during reviewer assignment. For example, some of the reviewers are much more stringent than others, leading to an unfair final decision, i.e., some submissions (i.e., papers or applications) with better quality are rejected. In this paper, we propose a context-aware reviewer assignment for trust enhanced peer review. More specifically, in our approach, we first consider the research area specific expertise of reviewers, and the institution relevance and co-authorship between reviewers and authors, so that reviewers with the right expertise are assigned to the corresponding submissions without potential conflict of interest. In addition, we propose a novel cross-assignment paradigm, and reviewers are cross-assigned in order to avoid assigning a group of stringent reviewers or a group of lenient reviewers to the same submission. More importantly, on top of them, we propose an academic CONtext-aware expertise relevanCe oriEnted Reviewer cross-assignmenT approach (CONCERT), which aims to effectively estimate the “true” ratings of submissions based on the ratings from all reviewers, even though no prior knowledge exists about the distribution of stringent reviewers and lenient reviewers. The experiments illustrate that compared with existing approaches, our proposed CONCERT approach can less likely assign more than one stringent reviewers or lenient reviewers to a submission simultaneously and significantly reduce the influence of ratings from stringent reviewers and lenient reviewers, leading to trust enhanced peer review and selection, no matter what kind of distributions of stringent reviewers and lenient reviewers are. PMID:26090849

The need for transparency and reproducibility in documenting values for regulatory decision making and evaluating causality: The example of formaldehyde.

PubMed

Van Landingham, Cynthia; Mundt, Kenneth A; Allen, Bruce C; Gentry, P Robinan

2016-11-01

Reproducibility and transparency in scientific reporting is paramount to advancing science and providing the foundation required for sound regulation. Recent examples demonstrate that pivotal scientific findings cannot be replicated, due to poor documentation or methodological bias, sparking debate across scientific and regulatory communities. However, there is general agreement that improvements in communicating and documenting research and risk assessment methods are needed. In the case of formaldehyde, the peer-review conducted by a National Academy of Sciences (NAS) Committee questioned the approaches used by the Integrated Risk Information System (IRIS) in developing draft unit risk values. Using the original data from the key study (Beane Freeman et al., 2009) and documentation provided in the draft IRIS profile, we attempted to duplicate the reported inhalation unit risk values and address the NAS Committee's questions regarding application of the appropriate dose-response model. Overall, documentation of the methods lacked sufficient detail to allow for replication of the unit risk estimates, specifically for Hodgkin lymphoma and leukemias, the key systemic endpoints selected by IRIS. The lack of apparent exposure-response relationships for selected endpoints raises the question whether quantitative analyses are appropriate for these endpoints, and if so, how results are to be interpreted. Copyright © 2016. Published by Elsevier Inc.

Pre-examination factors affecting molecular diagnostic test results and interpretation: A case-based approach.

PubMed

Payne, Deborah A; Baluchova, Katarina; Peoc'h, Katell H; van Schaik, Ron H N; Chan, K C Allen; Maekawa, Masato; Mamotte, Cyril; Russomando, Graciela; Rousseau, François; Ahmad-Nejad, Parviz

2017-04-01

Multiple organizations produce guidance documents that provide opportunities to harmonize quality practices for diagnostic testing. The International Organization for Standardization ISO 15189 standard addresses requirements for quality in management and technical aspects of the clinical laboratory. One technical aspect addresses the complexities of the pre-examination phase prior to diagnostic testing. The Committee for Molecular Diagnostics of the International Federation for Clinical Chemistry and Laboratory Medicine (also known as, IFCC C-MD) conducted a survey of international molecular laboratories and determined ISO 15189 to be the most referenced guidance document. In this review, the IFCC C-MD provides case-based examples illustrating the value of select pre-examination processes as these processes relate to molecular diagnostic testing. Case-based examples in infectious disease, oncology, inherited disease and pharmacogenomics address the utility of: 1) providing information to patients and users, 2) designing requisition forms, 3) obtaining informed consent and 4) maintaining sample integrity prior to testing. The pre-examination phase requires extensive and consistent communication between the laboratory, the healthcare provider and the end user. The clinical vignettes presented in this paper illustrate the value of applying select ISO 15189 recommendations for general laboratory to the more specialized area of Molecular Diagnostics. Copyright © 2016 Elsevier B.V. All rights reserved.

Variability in sex-determining mechanisms influences genome complexity in reptilia.

PubMed

Janes, D E; Organ, C L; Edwards, S V

2009-01-01

In this review, we describe the history of amniote sex determination as a classic example of Darwinian evolution. We suggest that evolutionary changes in sex determination provide a foundation for understanding important aspects of chromosome and genome organization that otherwise appear haphazard in their origins and contents. Species with genotypic sex determination often possess heteromorphic sex chromosomes, whereas species with environmental sex determination lack them. Through a series of mutations followed by selection at key genes, sex-determining mechanisms have turned over many times throughout the amniote lineage. As a consequence, amniote genomes have undergone gains or losses of sex chromosomes. We review the genomic and ecological contexts in which either temperature-dependent or genotypic sex determination has evolved. Once genotypic sex determination emerges in a lineage, viviparity and heteromorphic sex chromosomes become more likely to evolve. For example, in extinct marine reptiles, genotypic sex determination apparently led to viviparity, which in turn facilitated their pelagic radiation. Sex chromosomes comprise genome regions that differ from autosomes in recombination rate, mutation rate, levels of polymorphism, and the presence of sex-determining and sexually antagonistic genes. In short, many aspects of amniote genome complexity, life history, and adaptive radiation appear contingent on evolutionary changes in sex-determining mechanisms. Copyright 2010 S. Karger AG, Basel.

Variability in Sex-Determining Mechanisms Influences Genome Complexity in Reptilia

PubMed Central

Janes, D.E.; Organ, C.L.; Edwards, S.V.

2010-01-01

In this review, we describe the history of amniote sex determination as a classic example of Darwinian evolution. We suggest that evolutionary changes in sex determination provide a foundation for understanding important aspects of chromosome and genome organization that otherwise appear haphazard in their origins and contents. Species with genotypic sex determination often possess heteromorphic sex chromosomes, whereas species with environmental sex determination lack them. Through a series of mutations followed by selection at key genes, sex-determining mechanisms have turned over many times throughout the amniote lineage. As a consequence, amniote genomes have undergone gains or losses of sex chromosomes. We review the genomic and ecological contexts in which either temperature-dependent or genotypic sex determination has evolved. Once genotypic sex determination emerges in a lineage, viviparity and heteromorphic sex chromosomes become more likely to evolve. For example, in extinct marine reptiles, genotypic sex determination apparently led to viviparity, which in turn facilitated their pelagic radiation. Sex chromosomes comprise genome regions that differ from autosomes in recombination rate, mutation rate, levels of polymorphism, and the presence of sex-determining and sexually antagonistic genes. In short, many aspects of amniote genome complexity, life history, and adaptive radiation appear contingent on evolutionary changes in sex-determining mechanisms. PMID:20203474

Towards the next generation of simplified Dark Matter models

NASA Astrophysics Data System (ADS)

Albert, Andreas; Bauer, Martin; Brooke, Jim; Buchmueller, Oliver; Cerdeño, David G.; Citron, Matthew; Davies, Gavin; de Cosa, Annapaola; De Roeck, Albert; De Simone, Andrea; Du Pree, Tristan; Flaecher, Henning; Fairbairn, Malcolm; Ellis, John; Grohsjean, Alexander; Hahn, Kristian; Haisch, Ulrich; Harris, Philip C.; Khoze, Valentin V.; Landsberg, Greg; McCabe, Christopher; Penning, Bjoern; Sanz, Veronica; Schwanenberger, Christian; Scott, Pat; Wardle, Nicholas

2017-06-01

This White Paper is an input to the ongoing discussion about the extension and refinement of simplified Dark Matter (DM) models. It is not intended as a comprehensive review of the discussed subjects, but instead summarises ideas and concepts arising from a brainstorming workshop that can be useful when defining the next generation of simplified DM models (SDMM). In this spirit, based on two concrete examples, we show how existing SDMM can be extended to provide a more accurate and comprehensive framework to interpret and characterise collider searches. In the first example we extend the canonical SDMM with a scalar mediator to include mixing with the Higgs boson. We show that this approach not only provides a better description of the underlying kinematic properties that a complete model would possess, but also offers the option of using this more realistic class of scalar mixing models to compare and combine consistently searches based on different experimental signatures. The second example outlines how a new physics signal observed in a visible channel can be connected to DM by extending a simplified model including effective couplings. In the next part of the White Paper we outline other interesting options for SDMM that could be studied in more detail in the future. Finally, we review important aspects of supersymmetric models for DM and use them to propose how to develop more complete SDMMs. This White Paper is a summary of the brainstorming meeting "Next generation of simplified Dark Matter models" that took place at Imperial College, London on May 6, 2016, and corresponding follow-up studies on selected subjects.

A systems-level approach for metabolic engineering of yeast cell factories.

PubMed

Kim, Il-Kwon; Roldão, António; Siewers, Verena; Nielsen, Jens

2012-03-01

The generation of novel yeast cell factories for production of high-value industrial biotechnological products relies on three metabolic engineering principles: design, construction, and analysis. In the last two decades, strong efforts have been put on developing faster and more efficient strategies and/or technologies for each one of these principles. For design and construction, three major strategies are described in this review: (1) rational metabolic engineering; (2) inverse metabolic engineering; and (3) evolutionary strategies. Independent of the selected strategy, the process of designing yeast strains involves five decision points: (1) choice of product, (2) choice of chassis, (3) identification of target genes, (4) regulating the expression level of target genes, and (5) network balancing of the target genes. At the construction level, several molecular biology tools have been developed through the concept of synthetic biology and applied for the generation of novel, engineered yeast strains. For comprehensive and quantitative analysis of constructed strains, systems biology tools are commonly used and using a multi-omics approach. Key information about the biological system can be revealed, for example, identification of genetic regulatory mechanisms and competitive pathways, thereby assisting the in silico design of metabolic engineering strategies for improving strain performance. Examples on how systems and synthetic biology brought yeast metabolic engineering closer to industrial biotechnology are described in this review, and these examples should demonstrate the potential of a systems-level approach for fast and efficient generation of yeast cell factories. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Future perspectives of resin-based dental materials.

PubMed

Jandt, Klaus D; Sigusch, Bernd W

2009-08-01

This concise review and outlook paper gives a view of selected potential future developments in the area of resin-based biomaterials with an emphasis on dental composites. A selection of key publications (1 book, 35 scientific original publications and 1 website source) covering the areas nanotechnology, antimicrobial materials, stimuli responsive materials, self-repairing materials and materials for tissue engineering with direct or indirect relations and/or implications to resin-based dental materials is critically reviewed and discussed. Connections between these fields and their potential for resin-based dental materials are highlighted and put in perspective. The need to improve shrinkage properties and wear resistance is obvious for dental composites, and a vast number of attempts have been made to accomplish these aims. Future resin-based materials may be further improved in this respect if, for example nanotechnology is applied. Dental composites may, however, reach a completely new quality by utilizing new trends from materials science, such as introducing nanostructures, antimicrobial properties, stimuli responsive capabilities, the ability to promote tissue regeneration or repair of dental tissues if the composites were able to repair themselves. This paper shows selected potential future developments in the area of resin-based dental materials, gives basic and industrial researchers in dental materials science, and dental practitioners a glance into the potential future of these materials, and should stimulate discussion about needs and future developments in the area.

Measuring cognition in teams: a cross-domain review.

PubMed

Wildman, Jessica L; Salas, Eduardo; Scott, Charles P R

2014-08-01

The purpose of this article is twofold: to provide a critical cross-domain evaluation of team cognition measurement options and to provide novice researchers with practical guidance when selecting a measurement method. A vast selection of measurement approaches exist for measuring team cognition constructs including team mental models, transactive memory systems, team situation awareness, strategic consensus, and cognitive processes. Empirical studies and theoretical articles were reviewed to identify all of the existing approaches for measuring team cognition. These approaches were evaluated based on theoretical perspective assumed, constructs studied, resources required, level of obtrusiveness, internal consistency reliability, and predictive validity. The evaluations suggest that all existing methods are viable options from the point of view of reliability and validity, and that there are potential opportunities for cross-domain use. For example, methods traditionally used only to measure mental models may be useful for examining transactive memory and situation awareness. The selection of team cognition measures requires researchers to answer several key questions regarding the theoretical nature of team cognition and the practical feasibility of each method. We provide novice researchers with guidance regarding how to begin the search for a team cognition measure and suggest several new ideas regarding future measurement research. We provide (1) a broad overview and evaluation of existing team cognition measurement methods, (2) suggestions for new uses of those methods across research domains, and (3) critical guidance for novice researchers looking to measure team cognition.

Wildlife forensic science: A review of genetic geographic origin assignment.

PubMed

Ogden, Rob; Linacre, Adrian

2015-09-01

Wildlife forensic science has become a key means of enforcing legislation surrounding the illegal trade in protected and endangered species. A relatively new dimension to this area of forensic science is to determine the geographic origin of a seized sample. This review focuses on DNA testing, which relies on assignment of an unknown sample to its genetic population of origin. Key examples of this are the trade in timber, fish and ivory and these are used only to illustrate the large number of species for which this type of testing is potentially available. The role of mitochondrial and nuclear DNA markers is discussed, alongside a comparison of neutral markers with those exhibiting signatures of selection, which potentially offer much higher levels of assignment power to address specific questions. A review of assignment tests is presented along with detailed methods for evaluating error rates and considerations for marker selection. The availability and quality of reference data are of paramount importance to support assignment applications and ensure reliability of any conclusions drawn. The genetic methods discussed have been developed initially as investigative tools but comment is made regarding their use in courts. The potential to compliment DNA markers with elemental assays for greater assignment power is considered and finally recommendations are made for the future of this type of testing. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sex allocation and investment into pre- and post-copulatory traits in simultaneous hermaphrodites: the role of polyandry and local sperm competition.

PubMed

Schärer, Lukas; Pen, Ido

2013-03-05

Sex allocation theory predicts the optimal allocation to male and female reproduction in sexual organisms. In animals, most work on sex allocation has focused on species with separate sexes and our understanding of simultaneous hermaphrodites is patchier. Recent theory predicts that sex allocation in simultaneous hermaphrodites should strongly be affected by post-copulatory sexual selection, while the role of pre-copulatory sexual selection is much less clear. Here, we review sex allocation and sexual selection theory for simultaneous hermaphrodites, and identify several strong and potentially unwarranted assumptions. We then present a model that treats allocation to sexually selected traits as components of sex allocation and explore patterns of allocation when some of these assumptions are relaxed. For example, when investment into a male sexually selected trait leads to skews in sperm competition, causing local sperm competition, this is expected to lead to a reduced allocation to sperm production. We conclude that understanding the evolution of sex allocation in simultaneous hermaphrodites requires detailed knowledge of the different sexual selection processes and their relative importance. However, little is currently known quantitatively about sexual selection in simultaneous hermaphrodites, about what the underlying traits are, and about what drives and constrains their evolution. Future work should therefore aim at quantifying sexual selection and identifying the underlying traits along the pre- to post-copulatory axis.

Sex allocation and investment into pre- and post-copulatory traits in simultaneous hermaphrodites: the role of polyandry and local sperm competition

PubMed Central

Schärer, Lukas; Pen, Ido

2013-01-01

Sex allocation theory predicts the optimal allocation to male and female reproduction in sexual organisms. In animals, most work on sex allocation has focused on species with separate sexes and our understanding of simultaneous hermaphrodites is patchier. Recent theory predicts that sex allocation in simultaneous hermaphrodites should strongly be affected by post-copulatory sexual selection, while the role of pre-copulatory sexual selection is much less clear. Here, we review sex allocation and sexual selection theory for simultaneous hermaphrodites, and identify several strong and potentially unwarranted assumptions. We then present a model that treats allocation to sexually selected traits as components of sex allocation and explore patterns of allocation when some of these assumptions are relaxed. For example, when investment into a male sexually selected trait leads to skews in sperm competition, causing local sperm competition, this is expected to lead to a reduced allocation to sperm production. We conclude that understanding the evolution of sex allocation in simultaneous hermaphrodites requires detailed knowledge of the different sexual selection processes and their relative importance. However, little is currently known quantitatively about sexual selection in simultaneous hermaphrodites, about what the underlying traits are, and about what drives and constrains their evolution. Future work should therefore aim at quantifying sexual selection and identifying the underlying traits along the pre- to post-copulatory axis. PMID:23339243

A comparison of biological and cultural evolution.

PubMed

Portin, Petter

2015-03-01

This review begins with a definition of biological evolution and a description of its general principles. This is followed by a presentation of the biological basis of culture, specifically the concept of social selection. Further, conditions for cultural evolution are proposed, including a suggestion for language being the cultural replicator corresponding to the concept of the gene in biological evolution. Principles of cultural evolution are put forward and compared to the principles of biological evolution. Special emphasis is laid on the principle of selection in cultural evolution, including presentation of the concept of cultural fitness. The importance of language as a necessary condition for cultural evolution is stressed. Subsequently, prime differences between biological and cultural evolution are presented, followed by a discussion on interaction of our genome and our culture. The review aims at contributing to the present discussion concerning the modern development of the general theory of evolution, for example by giving a tentative formulation of the necessary and sufficient conditions for cultural evolution, and proposing that human creativity and mind reading or theory of mind are motors specific for it. The paper ends with the notion of the still ongoing coevolution of genes and culture.

Drug repurposing in kidney disease.

PubMed

Panchapakesan, Usha; Pollock, Carol

2018-07-01

Drug repurposing, is the re-tasking of known medications for new clinical indications. Advantages, compared to de novo drug development, include reduced cost and time to market plus the added benefit of a known pharmacokinetic and safety profiles. Suitable drug candidates are identified through serendipitous observations, data mining, or increased understanding of disease mechanisms. This review highlights drugs suited for repurposing in kidney disease. The main cause of mortality in patients with chronic kidney disease is cardiovascular disease. Hence, we have included CV endpoints for the drugs. This review begins with candidates in acute kidney injury: vasodilators levosimendan and vitamin D, followed by candidates in CKD, with particular focus on diabetic kidney disease, autosomal dominant polycystic kidney disease, and focal segmental glomerulosclerosis. Examples include glucose-lowering drugs (sodium glucose co-transporter 2 inhibitors, glucagon-like peptide 1 agonists, and metformin), which have mechanistic potential for cardiac and/or renal protection beyond glucose lowering, with broader applicability to the nondiabetic population; xanthine oxidase inhibitors (allopurinol, febuxostat), selective endothelin receptor A antagonist (atrasentan), Janus kinase inhibitor (baricitinib), selective costimulation modulator (abatacept), pentoxyfylline, and the DNA demethylating agent/vasodilator (hydralazine). Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Mediterranean blue tits as a case study of local adaptation.

PubMed

Charmantier, Anne; Doutrelant, Claire; Dubuc-Messier, Gabrielle; Fargevieille, Amélie; Szulkin, Marta

2016-01-01

While the study of the origins of biological diversity across species has provided numerous examples of adaptive divergence, the realization that it can occur at microgeographic scales despite gene flow is recent, and scarcely illustrated. We review here evidence suggesting that the striking phenotypic differentiation in ecologically relevant traits exhibited by blue tits Cyanistes caeruleus in their southern range-edge putatively reflects adaptation to the heterogeneity of the Mediterranean habitats. We first summarize the phenotypic divergence for a series of life history, morphological, behavioural, acoustic and colour ornament traits in blue tit populations of evergreen and deciduous forests. For each divergent trait, we review the evidence obtained from common garden experiments regarding a possible genetic origin of the observed phenotypic differentiation as well as evidence for heterogeneous selection. Second, we argue that most phenotypically differentiated traits display heritable variation, a fundamental requirement for evolution to occur. Third, we discuss nonrandom dispersal, selective barriers and assortative mating as processes that could reinforce local adaptation. Finally, we show how population genomics supports isolation - by - environment across landscapes. Overall, the combination of approaches converges to the conclusion that the strong phenotypic differentiation observed in Mediterranean blue tits is a fascinating case of local adaptation.

The Math You Need at Baylor University: Improving Quantitative Skills in an Introductory Geology Lab Course

NASA Astrophysics Data System (ADS)

Browning, S.

2014-12-01

The Math You Need (TMYN) modules were introduced at Baylor University in fall 2012 to address issues of math anxiety common among freshmen non-majors completing their lab science requirement, and to reduce lab time spent reviewing basic math concepts. Modules and associated assessment questions commonly use geoscience examples to illustrate the mathematical principles involved, reinforcing topics addressed in lab. Large enrollments in the course selected for these modules necessitate multiple graduate teaching assistants in the lab, making the online nature of the modules and minimal required involvement of the teaching assistants even more valuable. Students completed three selected modules before encountering associated topics in lab, as well as a pre and post-test to gauge improvement. This presentation will review lessons learned and changes made in the first two years of TMYN at Baylor. Results indicate continued increases in mean pre to post test scores (e.g. 3.2% in fall 2012 to 11.9% in spring 2014), percentage of student pre to post- test improvement (59% in fall 2012 to 72% in spring 2014) and student participation (95 in fall 2012 to 186 in spring 2014). Continued use of these modules is anticipated.

Microfluidic Lab-on-a-Chip Platforms: Requirements, Characteristics and Applications

NASA Astrophysics Data System (ADS)

Mark, D.; Haeberle, S.; Roth, G.; Von Stetten, F.; Zengerle, R.

This review summarizes recent developments in microfluidic platform approaches. In contrast to isolated application-specific solutions, a microfluidic platform provides a set of fluidic unit operations, which are designed for easy combination within a well-defined fabrication technology. This allows the implementation of different application-specific (bio-) chemical processes, automated by microfluidic process integration [1]. A brief introduction into technical advances, major market segments and promising applications is followed by a detailed characterization of different microfluidic platforms, comprising a short definition, the functional principle, microfluidic unit operations, application examples as well as strengths and limitations. The microfluidic platforms in focus are lateral flow tests, linear actuated devices, pressure driven laminar flow, microfluidic large scale integration, segmented flow microfluidics, centrifugal microfluidics, electro-kinetics, electrowetting, surface acoustic waves, and systems for massively parallel analysis. The review concludes with the attempt to provide a selection scheme for microfluidic platforms which is based on their characteristics according to key requirements of different applications and market segments. Applied selection criteria comprise portability, costs of instrument and disposable, sample throughput, number of parameters per sample, reagent consumption, precision, diversity of microfluidic unit operations and the flexibility in programming different liquid handling protocols.

[Perception scales of validated food insecurity: the experience of the countries in Latin America and the Caribbean].

PubMed

Sperandio, Naiara; Morais, Dayane de Castro; Priore, Silvia Eloiza

2018-02-01

The scope of this systematic review was to compare the food insecurity scales validated and used in the countries in Latin America and the Caribbean, and analyze the methods used in validation studies. A search was conducted in the Lilacs, SciELO and Medline electronic databases. The publications were pre-selected by titles and abstracts, and subsequently by a full reading. Of the 16,325 studies reviewed, 14 were selected. Twelve validated scales were identified for the following countries: Venezuela, Brazil, Colombia, Bolivia, Ecuador, Costa Rica, Mexico, Haiti, the Dominican Republic, Argentina and Guatemala. Besides these, there is the Latin American and Caribbean scale, the scope of which is regional. The scales ranged from the standard reference used, number of questions and diagnosis of insecurity. The methods used by the studies for internal validation were calculation of Cronbach's alpha and the Rasch model; for external validation the authors calculated association and /or correlation with socioeconomic and food consumption variables. The successful experience of Latin America and the Caribbean in the development of national and regional scales can be an example for other countries that do not have this important indicator capable of measuring the phenomenon of food insecurity.

Rapid and Automated Analytical Methods for Redox Species Based on Potentiometric Flow Injection Analysis Using Potential Buffers

PubMed Central

Ohura, Hiroki; Imato, Toshihiko

2011-01-01

Two analytical methods, which prove the utility of a potentiometric flow injection technique for determining various redox species, based on the use of some redox potential buffers, are reviewed. The first is a potentiometric flow injection method in which a redox couple such as Fe(III)-Fe(II), Fe(CN)6 3−-Fe(CN)(CN)6 4−, and bromide-bromine and a redox electrode or a combined platinum-bromide ion selective electrode are used. The analytical principle and advantages of the method are discussed, and several examples of its application are reported. Another example is a highly sensitive potentiometric flow injection method, in which a large transient potential change due to bromine or chlorine as an intermediate, generated during the reaction of the oxidative species with an Fe(III)-Fe(II) potential buffer containing bromide or chloride, is utilized. The analytical principle and details of the proposed method are described, and examples of several applications are described. The determination of trace amounts of hydrazine, based on the detection of a transient change in potential caused by the reaction with a Ce(IV)-Ce(III) potential buffer, is also described. PMID:21584280

Biomolecular engineering of intracellular switches in eukaryotes

PubMed Central

Pastuszka, M.K.; Mackay, J.A.

2010-01-01

Tools to selectively and reversibly control gene expression are useful to study and model cellular functions. When optimized, these cellular switches can turn a protein's function “on” and “off” based on cues designated by the researcher. These cues include small molecules, drugs, hormones, and even temperature variations. Here we review three distinct areas in gene expression that are commonly targeted when designing cellular switches. Transcriptional switches target gene expression at the level of mRNA polymerization, with examples including the tetracycline gene induction system as well as nuclear receptors. Translational switches target the process of turning the mRNA signal into protein, with examples including riboswitches and RNA interference. Post-translational switches control how proteins interact with one another to attenuate or relay signals. Examples of post-translational modification include dimerization and intein splicing. In general, the delay times between switch and effect decreases from transcription to translation to post-translation; furthermore, the fastest switches may offer the most elegant opportunities to influence and study cell behavior. We discuss the pros and cons of these strategies, which directly influence their usefulness to study and implement drug targeting at the tissue and cellular level. PMID:21209849

Extraordinary capabilities of optical devices incorporating guided-mode resonance gratings: application summary and recent examples

NASA Astrophysics Data System (ADS)

Magnusson, Robert; Yoon, Jae Woong; Amin, Mohammad Shyiq; Khaleque, Tanzina; Uddin, Mohammad Jalal

2014-03-01

For selected device concepts that are members of an evolving class of photonic devices enabled by guided-mode resonance (GMR) effects, we review physics of operation, design, fabrication, and characterization. We summarize the application potential of this field and provide new and emerging aspects. Our chosen examples include resonance elements with extremely wide reflection bands. Thus, in a multilevel structure with conformal germanium (Ge) films, reflectance exceeds 99% for spectral widths approaching 1100 nm. A simpler design, incorporating a partially etched single Ge layer on a glass substrate, exhibits a high-reflectance bandwidth close to 900 nm. We present a couple of interesting new device concepts enabled by GMRs coexisting with the Rayleigh anomaly. Our example Rayleigh reflector exhibits a wideband high-efficiency flattop spectrum and extremely rapid angular transitions. Moreover, we show that it is possible to fashion transmission filters by excitation of leaky resonant modes at the Rayleigh anomaly in a subwavelength nanograting. A unique transmission spectrum results, which is tightly delimited in angle and wavelength as experimentally demonstrated. We update our application list with new developments including GMR-based coherent perfect absorbers, multiparametric biosensors, and omnidirectional wideband absorbers.

Feature-based fusion of medical imaging data.

PubMed

Calhoun, Vince D; Adali, Tülay

2009-09-01

The acquisition of multiple brain imaging types for a given study is a very common practice. There have been a number of approaches proposed for combining or fusing multitask or multimodal information. These can be roughly divided into those that attempt to study convergence of multimodal imaging, for example, how function and structure are related in the same region of the brain, and those that attempt to study the complementary nature of modalities, for example, utilizing temporal EEG information and spatial functional magnetic resonance imaging information. Within each of these categories, one can attempt data integration (the use of one imaging modality to improve the results of another) or true data fusion (in which multiple modalities are utilized to inform one another). We review both approaches and present a recent computational approach that first preprocesses the data to compute features of interest. The features are then analyzed in a multivariate manner using independent component analysis. We describe the approach in detail and provide examples of how it has been used for different fusion tasks. We also propose a method for selecting which combination of modalities provides the greatest value in discriminating groups. Finally, we summarize and describe future research topics.

[Efficiency indicators to assess the organ donation and transplantation process: systematic review of the literature].

PubMed

Siqueira, Marina Martins; Araujo, Claudia Affonso; de Aguiar Roza, Bartira; Schirmer, Janine

2016-08-01

To search the literature and identify indicators used to monitor and control the organ donation and transplantation process and to group these indicators into categories. In November 2014, a systematic review of the literature was carried out in the following databases: Biblioteca Virtual em Saúde (BVS), EBSCO, Emerald, Proquest, Science Direct, and Web of Science. The following search terms (and the corresponding terms in Brazilian Portuguese) were employed: "efficiency," "indicators," "organ donation," "tissue and organ procurement," and "organ transplantation." Of the 344 articles retrieved, 23 original articles published between 1992 and 2013 were selected and reviewed for analysis of efficiency indicators. The review revealed 117 efficiency indicators, which were grouped according to similarity of content and divided into three categories: 1) 71 indicators related to organ donation, covering mortality statistics, communication of brain death, clinical status of donors and exclusion of donors for medical reasons, attitude of families, confirmation of donations, and extraction of organs and tissues; 2) 22 indicators related to organ transplantation, covering the surgical procedure per se and post-transplantation follow-up; and 3) 24 indicators related to the demand for organs and the resources of hospitals involved in the process. Even if organ transplantation is a recent phenomenon, the high number of efficiency indicators described in the literature suggests that scholars interested in this field have been searching for ways to measure performance. However, there is little standardization of the indicators used. Also, most indicators focus on the donation step, suggesting gaps in the measurement of efficiency at others points in the process. Additional indicators are needed to monitor important stages, such as organ distribution (for example, organ loss indicators) and post-transplantation aspects (for example, survival and quality of life).

Multiclass Continuous Correspondence Learning

NASA Technical Reports Server (NTRS)

Bue, Brian D,; Thompson, David R.

2011-01-01

We extend the Structural Correspondence Learning (SCL) domain adaptation algorithm of Blitzer er al. to the realm of continuous signals. Given a set of labeled examples belonging to a 'source' domain, we select a set of unlabeled examples in a related 'target' domain that play similar roles in both domains. Using these 'pivot samples, we map both domains into a common feature space, allowing us to adapt a classifier trained on source examples to classify target examples. We show that when between-class distances are relatively preserved across domains, we can automatically select target pivots to bring the domains into correspondence.

Microbial secondary metabolites and their impacts on insect symbioses.

PubMed

Klassen, Jonathan L

2014-10-01

All insects host communities of microbes that interact both with the insect and each other. Secondary metabolites are understood to mediate many of these interactions, although examples having robust genetic, chemical and/or ecological evidence are relatively rare. Here, I review secondary metabolites mediating community interactions in the beewolf, entomopathogenic nematode and fungus-growing ant symbioses, using the logic of Koch's postulates to emphasize well-validated symbiotic functions mediated by these metabolites. I especially highlight how these interaction networks are structured by both ecological and evolutionary processes, and how selection acting on secondary metabolite production can be multidimensional. Copyright © 2014 Elsevier Inc. All rights reserved.

Techniques for extraction and isolation of natural products: a comprehensive review.

PubMed

Zhang, Qing-Wen; Lin, Li-Gen; Ye, Wen-Cai

2018-01-01

Natural medicines were the only option for the prevention and treatment of human diseases for thousands of years. Natural products are important sources for drug development. The amounts of bioactive natural products in natural medicines are always fairly low. Today, it is very crucial to develop effective and selective methods for the extraction and isolation of those bioactive natural products. This paper intends to provide a comprehensive view of a variety of methods used in the extraction and isolation of natural products. This paper also presents the advantage, disadvantage and practical examples of conventional and modern techniques involved in natural products research.

[Supramolecular Agents for Theranostics].

PubMed

Deyev, S M; Lebedenko, E N

2015-01-01

This mini-review summarizes recent data obtained in the process of creation of a versatile module platform suitable for construction of supramolecular theranostic agents. As an example, we consider multifunctional hybrid agents for imaging and elimination of cancer cells. The use of an adapter protein system barnase:barstar for producing targeted multifunctional hybrid structures on the basis of highly specific peptides and mini-antibodies as addressing modules and recombinant proteins and/or nanoparticles of different nature (quantum dots, nanogold, magnetic nanoparticles, nanodiamonds, upconverting nanophosphores, polymer nanoparticles) as agents visualizing and damaging cancer cells is described. New perspectives for creation of selective and highly effective compounds for theranostics and personified medicine are contemplated.

Human Centred Design Considerations for Connected Health Devices for the Older Adult

PubMed Central

Harte, Richard P.; Glynn, Liam G.; Broderick, Barry J.; Rodriguez-Molinero, Alejandro; Baker, Paul M. A.; McGuiness, Bernadette; O’Sullivan, Leonard; Diaz, Marta; Quinlan, Leo R.; ÓLaighin, Gearóid

2014-01-01

Connected health devices are generally designed for unsupervised use, by non-healthcare professionals, facilitating independent control of the individuals own healthcare. Older adults are major users of such devices and are a population significantly increasing in size. This group presents challenges due to the wide spectrum of capabilities and attitudes towards technology. The fit between capabilities of the user and demands of the device can be optimised in a process called Human Centred Design. Here we review examples of some connected health devices chosen by random selection, assess older adult known capabilities and attitudes and finally make analytical recommendations for design approaches and design specifications. PMID:25563225

Nanoscale chirality in metal and semiconductor nanoparticles

PubMed Central

Thomas, K. George

2016-01-01

The field of chirality has recently seen a rejuvenation due to the observation of chirality in inorganic nanomaterials. The advancements in understanding the origin of nanoscale chirality and the potential applications of chiroptical nanomaterials in the areas of optics, catalysis and biosensing, among others, have opened up new avenues toward new concepts and design of novel materials. In this article, we review the concept of nanoscale chirality in metal nanoclusters and semiconductor quantum dots, then focus on recent experimental and theoretical advances in chiral metal nanoparticles and plasmonic chirality. Selected examples of potential applications and an outlook on the research on chiral nanomaterials are additionally provided. PMID:27752651

Nanoscale chirality in metal and semiconductor nanoparticles.

PubMed

Kumar, Jatish; Thomas, K George; Liz-Marzán, Luis M

2016-10-18

The field of chirality has recently seen a rejuvenation due to the observation of chirality in inorganic nanomaterials. The advancements in understanding the origin of nanoscale chirality and the potential applications of chiroptical nanomaterials in the areas of optics, catalysis and biosensing, among others, have opened up new avenues toward new concepts and design of novel materials. In this article, we review the concept of nanoscale chirality in metal nanoclusters and semiconductor quantum dots, then focus on recent experimental and theoretical advances in chiral metal nanoparticles and plasmonic chirality. Selected examples of potential applications and an outlook on the research on chiral nanomaterials are additionally provided.

NASA aviation safety reporting system

NASA Technical Reports Server (NTRS)

1978-01-01

Reports describing various types of communication problems are presented along with summaries dealing with judgment and decision making. Concerns relating to the ground proximity warning system are summarized and several examples of true terrain proximity warnings are provided. An analytic study of reports relating to profile descents was performed. Problems were found to be associated with charting and graphic presentation of the descents, with lack of uniformity of the descent procedures among facilities using them, and with the flight crew workload engendered by profile descents, particularly when additional requirements are interposed by air traffic control during the execution of the profiles. A selection of alert bulletins and responses to them were reviewed.

Disinhibition, an emerging pharmacology of learning and memory.

PubMed

Möhler, Hanns; Rudolph, Uwe

2017-01-01

Learning and memory are dependent on interactive excitatory and inhibitory mechanisms. In this review, we discuss a mechanism called disinhibition, which is the release of an inhibitory constraint that effectively results in an increased activity in the target neurons (for example, principal or projection neurons). We focus on discussing the role of disinhibition in learning and memory at a basic level and in disease models with cognitive deficits and highlight a strategy to reverse cognitive deficits caused by excess inhibition, through disinhibition of α5-containing GABA A receptors mediating tonic inhibition in the hippocampus, based on subtype-selective negative allosteric modulators as a novel class of drugs.

Polymer separations by liquid interaction chromatography: principles - prospects - limitations.

PubMed

Radke, Wolfgang

2014-03-28

Most heterogeneities of polymers with respect to different structural features cannot be resolved by only size exclusion chromatography (SEC), the most frequently applied mode of polymer chromatography. Instead, methods of interaction chromatography became increasingly important. However, despite the increasing applications the principles and potential of polymer interaction chromatography are still often unknown to a large number of polymer scientists. The present review will explain the principles of the different modes of polymer chromatography. Based on selected examples it will be shown which separation techniques can be successfully applied for separations with respect to the different structural features of polymers. Copyright © 2013 Elsevier B.V. All rights reserved.

Pheromone communication in amphibians and reptiles.

PubMed

Houck, Lynne D

2009-01-01

This selective review considers herpetological papers that feature the use of chemical cues, particularly pheromones involved in reproductive interactions between potential mates. Primary examples include garter snake females that attract males, lacertid lizards and the effects of their femoral gland secretions, aquatic male newts that chemically attract females, and terrestrial salamander males that chemically persuade a female to mate. Each case study spans a number of research approaches (molecular, biochemical, behavioral) and is related to sensory processing and the physiological effects of pheromone delivery. These and related studies show that natural pheromones can be identified, validated with behavioral tests, and incorporated in research on vomeronasal functional response.

Systems biology and livestock production.

PubMed

Headon, D

2013-12-01

The mapping of complete sets of genes, transcripts and proteins from many organisms has prompted the development of new '-omic' technologies for collecting and analysing very large amounts of data. Now that the tools to generate and interrogate such complete data sets are widely used, much of the focus of biological research has begun to turn towards understanding systems as a whole, rather than studying their components in isolation. This very broadly defined systems approach is being deployed across a range of problems and scales of organisation, including many aspects of the animal sciences. Here I review selected examples of this systems approach as applied to poultry and livestock production, product quality and welfare.

Building and testing models with extended Higgs sectors

NASA Astrophysics Data System (ADS)

Ivanov, Igor P.

2017-07-01

Models with non-minimal Higgs sectors represent a mainstream direction in theoretical exploration of physics opportunities beyond the Standard Model. Extended scalar sectors help alleviate difficulties of the Standard Model and lead to a rich spectrum of characteristic collider signatures and astroparticle consequences. In this review, we introduce the reader to the world of extended Higgs sectors. Not pretending to exhaustively cover the entire body of literature, we walk through a selection of the most popular examples: the two- and multi-Higgs-doublet models, as well as singlet and triplet extensions. We will show how one typically builds models with extended Higgs sectors, describe the main goals and the challenges which arise on the way, and mention some methods to overcome them. We will also describe how such models can be tested, what are the key observables one focuses on, and illustrate the general strategy with a subjective selection of results.

Rapid bursts and slow declines: on the possible evolutionary trajectories of enzymes

PubMed Central

Newton, Matilda S.; Arcus, Vickery L.; Patrick, Wayne M.

2015-01-01

The evolution of enzymes is often viewed as following a smooth and steady trajectory, from barely functional primordial catalysts to the highly active and specific enzymes that we observe today. In this review, we summarize experimental data that suggest a different reality. Modern examples, such as the emergence of enzymes that hydrolyse human-made pesticides, demonstrate that evolution can be extraordinarily rapid. Experiments to infer and resurrect ancient sequences suggest that some of the first organisms present on the Earth are likely to have possessed highly active enzymes. Reconciling these observations, we argue that rapid bursts of strong selection for increased catalytic efficiency are interspersed with much longer periods in which the catalytic power of an enzyme erodes, through neutral drift and selection for other properties such as cellular energy efficiency or regulation. Thus, many enzymes may have already passed their catalytic peaks. PMID:25926697

Insights about Striatal Circuit Function and Schizophrenia from a Mouse Model of D2 Receptor Upregulation

PubMed Central

Simpson, Eleanor H.; Kellendonk, Christoph

2016-01-01

The dopamine hypothesis of schizophrenia is supported by a large number of imaging studies that have identified an increase in dopamine binding at the D2 receptor selectively in the striatum. Here we review a decade of work using a regionally restricted and temporally regulated transgenic mouse model to investigate the behavioral, molecular, electrophysiological, and anatomical consequences of selective D2 receptor upregulation in the striatum. These studies have identified new and potentially important biomarkers at the circuit and molecular level that can now be explored in patients with schizophrenia. They provide an example of how animal models and their detailed level of neurobiological analysis allow a deepening of our understanding of the relationship between neuronal circuit function and symptoms of schizophrenia, and as a consequence generate new hypotheses that are testable in patients. PMID:27720388

Portable Nanoparticle-Based Sensors for Food Safety Assessment

PubMed Central

Bülbül, Gonca; Hayat, Akhtar; Andreescu, Silvana

2015-01-01

The use of nanotechnology-derived products in the development of sensors and analytical measurement methodologies has increased significantly over the past decade. Nano-based sensing approaches include the use of nanoparticles (NPs) and nanostructures to enhance sensitivity and selectivity, design new detection schemes, improve sample preparation and increase portability. This review summarizes recent advancements in the design and development of NP-based sensors for assessing food safety. The most common types of NPs used to fabricate sensors for detection of food contaminants are discussed. Selected examples of NP-based detection schemes with colorimetric and electrochemical detection are provided with focus on sensors for the detection of chemical and biological contaminants including pesticides, heavy metals, bacterial pathogens and natural toxins. Current trends in the development of low-cost portable NP-based technology for rapid assessment of food safety as well as challenges for practical implementation and future research directions are discussed. PMID:26690169

Regulated Proteolysis in Bacteria.

PubMed

Mahmoud, Samar A; Chien, Peter

2018-06-20

Regulated proteolysis is a vital process that affects all living things. Bacteria use energy-dependent AAA+ proteases to power degradation of misfolded and native regulatory proteins. Given that proteolysis is an irreversible event, specificity and selectivity in degrading substrates are key. Specificity is often augmented through the use of adaptors that modify the inherent specificity of the proteolytic machinery. Regulated protein degradation is intricately linked to quality control, cell-cycle progression, and physiological transitions. In this review, we highlight recent work that has shed light on our understanding of regulated proteolysis in bacteria. We discuss the role AAA+ proteases play during balanced growth as well as how these proteases are deployed during changes in growth. We present examples of how protease selectivity can be controlled in increasingly complex ways. Finally, we describe how coupling a core recognition determinant to one or more modifying agents is a general theme for regulated protein degradation.

Application of Nuclear Magnetic Resonance and Hybrid Methods to Structure Determination of Complex Systems.

PubMed

Prischi, Filippo; Pastore, Annalisa

2016-01-01

The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.

Bio-Inspired Networking — Self-Organizing Networked Embedded Systems

NASA Astrophysics Data System (ADS)

Dressler, Falko

The turn to nature has brought us many unforeseen great concepts and solutions. This course seems to hold on for many research domains. In this article, we study the applicability of biological mechanisms and techniques in the domain of communications. In particular, we study the behavior and the challenges in networked embedded systems that are meant to self-organize in large groups of nodes. Application examples include wireless sensor networks and sensor/actuator networks. Based on a review of the needs and requirements in such networks, we study selected bio-inspired networking approaches that claim to outperform other methods in specific domains. We study mechanisms in swarm intelligence, the artificial immune system, and approaches based on investigations on the cellular signaling pathways. As a major conclusion, we derive that bio-inspired networking techniques do have advantages compared to engineering methods. Nevertheless, selection and employment must be done carefully to achieve the desired performance gains.

Unknown components of the plastidial permeome

PubMed Central

Pick, Thea R.; Weber, Andreas P. M.

2014-01-01

Beyond their role in photosynthesis plastids provide a plethora of additional metabolic functions to plant cells. For example, they harbor complete biosynthetic pathways for the de novo synthesis of carotenoids, fatty acids, and amino acids. Furthermore plastids contribute important reactions to multi-compartmentalized pathways, such as photorespiration or plant hormone syntheses, and they depend on the import of essential molecules that they cannot synthesize themselves, such as ascorbic acid. This causes a high traffic of metabolites across the plastid envelope. Although it was recently shown that non-polar substrates could be exchanged between the plastid and the ER without involving transporters, various essential transport processes are mediated by highly selective but still unknown metabolite transporters. This review focuses on selected components of the plastidial permeome that are predicted to exist but that have not yet been identified as molecular entities, such as the transporters for isopentenyl diphosphate (IPP) or ascorbic acid. PMID:25191333

NASTRAN as an analytical research tool for composite mechanics and composite structures

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Sinclair, J. H.; Sullivan, T. L.

1976-01-01

Selected examples are described in which NASTRAN is used as an analysis research tool for composite mechanics and for composite structural components. The examples were selected to illustrate the importance of using NASTRAN as an analysis tool in this rapidly advancing field.

Passive and active mechanical properties of biotemplated ceramics revisited.

PubMed

Van Opdenbosch, Daniel; Fritz-Popovski, Gerhard; Plank, Johann; Zollfrank, Cordt; Paris, Oskar

2016-10-13

Living nature and human technology apply different principles to create hard, strong and tough materials. In this review, we compare and discuss prominent aspects of these alternative strategies, and demonstrate for selected examples that nanoscale-precision biotemplating is able to produce uncommon mechanical properties as well as actuating behavior, resembling to some extent the properties of the original natural templates. We present and discuss mechanical testing data showing for the first time that nanometer-precision biotemplating can lead to porous ceramic materials with deformation characteristics commonly associated with either biological or highly advanced technical materials. We also review recent findings on the relation between hierarchical structuring and humidity-induced directional motion. Finally, we discuss to which extent the observed behavior is in agreement with previous results and theories on the mechanical properties of multiscale hierarchical materials, as well as studies of highly disperse technical materials, together with an outlook for further lines of investigation.

Analysis of Alerting System Failures in Commercial Aviation Accidents

NASA Technical Reports Server (NTRS)

Mumaw, Randall J.

2017-01-01

The role of an alerting system is to make the system operator (e.g., pilot) aware of an impending hazard or unsafe state so the hazard can be avoided or managed successfully. A review of 46 commercial aviation accidents (between 1998 and 2014) revealed that, in the vast majority of events, either the hazard was not alerted or relevant hazard alerting occurred but failed to aid the flight crew sufficiently. For this set of events, alerting system failures were placed in one of five phases: Detection, Understanding, Action Selection, Prioritization, and Execution. This study also reviewed the evolution of alerting system schemes in commercial aviation, which revealed naive assumptions about pilot reliability in monitoring flight path parameters; specifically, pilot monitoring was assumed to be more effective than it actually is. Examples are provided of the types of alerting system failures that have occurred, and recommendations are provided for alerting system improvements.

Light and colour as analytical detection tools: a journey into the periodic table using polyamines to bio-inspired systems as chemosensors.

PubMed

Lodeiro, Carlos; Capelo, José Luis; Mejuto, Juan Carlos; Oliveira, Elisabete; Santos, Hugo M; Pedras, Bruno; Nuñez, Cristina

2010-08-01

This critical review describes some developments on the chemistry of fluorescent and colorimetric molecular probes or chemosensors, based on polyamines and associated compounds having oxygen and/or sulfur as donor atoms. The reported systems are essentially based on some selected published work in this field in the last five years, and in the work developed by the authors from 2000 onwards. Some interesting properties beyond sensing molecules, ions or/and cations by fluorescence, colorimetry as well as by MALDI-TOF MS spectrometry can arise from these systems. A short brief on different examples activated by PET (photoinduced electron transfer), ICT (internal charge transfer) and EET (electronic energy transfer) phenomena will be provided. Finally the introduction of bio-inspired compounds derived from emissive amino acid or short peptide systems and nanoparticle devices to detect metal ions will be reviewed (202 references).

Carbon–hydrogen (C–H) bond activation at PdIV: a Frontier in C–H functionalization catalysis

PubMed Central

Topczewski, Joseph J.

2015-01-01

The direct functionalization of carbon–hydrogen (C–H) bonds has emerged as a versatile strategy for the synthesis and derivatization of organic molecules. Among the methods for C–H bond activation, catalytic processes that utilize a PdII/PdIV redox cycle are increasingly common. The C–H activation step in most of these catalytic cycles is thought to occur at a PdII centre. However, a number of recent reports have suggested the feasibility of C–H cleavage occurring at PdIV complexes. Importantly, these latter processes often result in complementary reactivity and selectivity relative to analogous transformations at PdII. This mini review highlights proposed examples of C–H activation at PdIV centres. Applications of this transformation in catalysis as well as mechanistic details obtained from stoichiometric model studies are discussed. Furthermore, challenges and future perspectives for the field are reviewed. PMID:25544882

Carbon-Hydrogen (C-H) Bond Activation at PdIV: A Frontier in C-H Functionalization Catalysis.

PubMed

Topczewski, Joseph J; Sanford, Melanie S

2015-01-01

The direct functionalization of carbon-hydrogen (C-H) bonds has emerged as a versatile strategy for the synthesis and derivatization of organic molecules. Among the methods for C-H bond activation, catalytic processes that utilize a Pd II /Pd IV redox cycle are increasingly common. The C-H activation step in most of these catalytic cycles is thought to occur at a Pd II centre. However, a number of recent reports have suggested the feasibility of C-H cleavage occurring at Pd IV complexes. Importantly, these latter processes often result in complementary reactivity and selectivity relative to analogous transformations at Pd II . This Mini Review highlights proposed examples of C-H activation at Pd IV centres. Applications of this transformation in catalysis as well as mechanistic details obtained from stoichiometric model studies are discussed. Furthermore, challenges and future perspectives for the field are reviewed.

Sleep Disorders Among Holocaust Survivors: A Review of Selected Publications.

PubMed

Lurie, Ido

2017-09-01

After World War II, traumatic after effects often caused persistent sleep disorders for Holocaust survivors (HSs). This is a review of studies reporting on sleep disturbances and nightmares (as primary or secondary outcomes) among HSs between 1939 and 2015, conducted in various countries and contexts (clinical settings, pension claims, community surveys, sleep laboratories). Most studies revealed various sleep disturbances among HSs. Some studies found those disturbances in the absence of clinical disorders. Both men and women reported similar frequencies of sleep disturbances, although posttraumatic stress disorder and depression were more frequent in women. Sleep laboratory studies provided the single most direct and detailed sources of information. Findings included a) long-standing changes in sleep architecture, for example, decreased rapid eye movement (REM) sleep, and b) contrasting patterns of dreaming and recall among better versus poorly adjusted survivors. These results are of importance to both HSs and their families and for medical and mental health professionals.

Emerging infection and sepsis biomarkers: will they change current therapies?

PubMed Central

Jacobs, Lauren

2016-01-01

Introduction Sepsis is a heterogeneous syndrome characterized by both immune hyperactivity and relative immune suppression. Biomarkers have the potential to improve recognition and management of sepsis through three main applications: diagnosis, monitoring response to treatment, and stratifying patients based on prognosis or underlying biological response. Areas Covered This review focuses on specific examples of well-studied, evidence-supported biomarkers, and discusses their role in clinical practice with special attention to antibiotic stewardship and cost-effectiveness. Biomarkers were selected based on availability of robust prospective trials and meta-analyses which supported their role as emerging tools to improve the clinical management of sepsis. Expert Commentary Great strides have been made in candidate sepsis biomarker discovery and testing, with the biomarkers in this review showing promise. Yet sepsis remains a dynamic illness with a great degree of biological heterogeneity – heterogeneity which may be further resolved by recently discovered gene expression-based endotypes in septic shock. PMID:27533847

Heterogeneity of obsessive-compulsive disorder: a literature review.

PubMed

Lochner, Christine; Stein, Dan J

2003-01-01

Significant advances have been made in characterizing the phenomenology and psychobiology of obsessive-compulsive disorder (OCD) in recent years. In many ways, such advances suggest a conceptualization of OCD as a relatively homogeneous neuropsychiatric entity, underpinned by particular mechanisms that manifest in universal symptoms. Nevertheless, some data have pointed to the heterogeneity of this disorder. A computerized literature search (MEDLINE: 1964-2001) was used to collect studies addressing the heterogeneity of OCD. In addition, reviews of the phenomenology, psychobiology, family studies, and treatment of OCD were examined in an attempt to collate data addressing this issue. There is a growing consensus that some subtypes of OCD are valid and provide a useful means of integrating data on its symptomatology, neurobiology, and treatment response; for example, OCD with comorbid tics is characterized by earlier onset, a particular range of OCD symptoms, and worse response to selective serotonin reuptake inhibitors. The heterogeneity of OCD has important clinical and research implications.

The sweet tooth of biopharmaceuticals: importance of recombinant protein glycosylation analysis.

PubMed

Lingg, Nico; Zhang, Peiqing; Song, Zhiwei; Bardor, Muriel

2012-12-01

Biopharmaceuticals currently represent the fastest growing sector of the pharmaceutical industry, mainly driven by a rapid expansion in the manufacture of recombinant protein-based drugs. Glycosylation is the most prominent post-translational modification occurring on these protein drugs. It constitutes one of the critical quality attributes that requires thorough analysis for optimal efficacy and safety. This review examines the functional importance of glycosylation of recombinant protein drugs, illustrated using three examples of protein biopharmaceuticals: IgG antibodies, erythropoietin and glucocerebrosidase. Current analytical methods are reviewed as solutions for qualitative and quantitative measurements of glycosylation to monitor quality target product profiles of recombinant glycoprotein drugs. Finally, we propose a framework for designing the quality target product profile of recombinant glycoproteins and planning workflow for glycosylation analysis with the selection of available analytical methods and tools. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent advances in combination of capillary electrophoresis with mass spectrometry: methodology and theory.

PubMed

Klepárník, Karel

2015-01-01

This review focuses on the latest development of microseparation electromigration methods in capillaries and microfluidic devices with MS detection and identification. A wide selection of 183 relevant articles covers the literature published from June 2012 till May 2014 as a continuation of the review article on the same topic by Kleparnik [Electrophoresis 2013, 34, 70-86]. Special attention is paid to the new improvements in the theory of instrumentation and methodology of MS interfacing with capillary versions of zone electrophoresis, ITP, and IEF. Ionization methods in MS include ESI, MALDI, and ICP. Although the main attention is paid to the development of instrumentation and methodology, representative examples illustrate also applications in the proteomics, glycomics, metabolomics, biomarker research, forensics, pharmacology, food analysis, and single-cell analysis. The combinations of MS with capillary versions of electrochromatography and micellar electrokinetic chromatography are not included. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Resistance to bio-insecticides or how to enhance their sustainability: a review.

PubMed

Siegwart, Myriam; Graillot, Benoit; Blachere Lopez, Christine; Besse, Samantha; Bardin, Marc; Nicot, Philippe C; Lopez-Ferber, Miguel

2015-01-01

After more than 70 years of chemical pesticide use, modern agriculture is increasingly using biological control products. Resistances to conventional insecticides are wide spread, while those to bio-insecticides have raised less attention, and resistance management is frequently neglected. However, a good knowledge of the limitations of a new technique often provides greater sustainability. In this review, we compile cases of resistance to widely used bio-insecticides and describe the associated resistance mechanisms. This overview shows that all widely used bio-insecticides ultimately select resistant individuals. For example, at least 27 species of insects have been described as resistant to Bacillus thuringiensis toxins. The resistance mechanisms are at least as diverse as those that are involved in resistance to chemical insecticides, some of them being common to bio-insecticides and chemical insecticides. This analysis highlights the specific properties of bio-insecticides that the scientific community should use to provide a better sustainability of these products.

Ionic liquid syntheses via click chemistry: expeditious routes toward versatile functional materials.

PubMed

Mirjafari, Arsalan

2018-03-25

Since the introduction of click chemistry by K. B. Sharpless in 2001, its exploration and exploitation has occurred in countless fields of materials sciences in both academic and industrial spheres. Click chemistry is defined as an efficient, robust, and orthogonal synthetic platform for the facile formation of new carbon-heteroatom bonds, using readily available starting materials. Premier examples of click reactions are copper(i)-catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) and the thiol-X (X = ene and yne) coupling reactions to form C-N and C-S bonds, respectively. The emphasis of this review is centered on the rapidly expanding area of click chemistry-mediated synthesis of functional ionic liquids via CuAAC, thiol-X and oxime formation, and selected examples of nucleophilic ring-opening reactions, while offering some thoughts on emerging challenges, opportunities and ultimately the evolution of this field. Click chemistry offers tremendous opportunities, and introduces intriguing perspectives for efficient and robust generation of tailored task-specific ionic liquids - an important class of soft materials.

Salt disproportionation: A material science perspective.

PubMed

Thakral, Naveen K; Kelly, Ron C

2017-03-30

While screening the counter-ions for salt selection for an active pharmaceutical substance, there is often an uncertainty about disproportionation of the salt and hence physical stability of the final product formulation to provide adequate shelf life. Several examples of disproportionation reactions are reviewed to explain the concepts of pHmax, microenvironmental pH, and buffering capacity of excipients and APIs to gain mechanistic understanding of disproportionation reaction. Miscellaneous factors responsible for disproportionation are examined. In addition to the dissolution failure due to the formation of less soluble unionized form, various implications of the disproportionation are evaluated with specific examples. During lead optimization and early stages of development, when only a limited amount of material is available, use of predictive tools like mathematical models and model free kinetics to rank order the various counter-ions are discussed in detail. Finally, analytical methods and mitigation strategies are discussed to prevent the disproportionation by detecting it during early stages of drug development. Copyright © 2017 Elsevier B.V. All rights reserved.

3D printing of soft robotic systems

NASA Astrophysics Data System (ADS)

Wallin, T. J.; Pikul, J.; Shepherd, R. F.

2018-06-01

Soft robots are capable of mimicking the complex motion of animals. Soft robotic systems are defined by their compliance, which allows for continuous and often responsive localized deformation. These features make soft robots especially interesting for integration with human tissues, for example, the implementation of biomedical devices, and for robotic performance in harsh or uncertain environments, for example, exploration in confined spaces or locomotion on uneven terrain. Advances in soft materials and additive manufacturing technologies have enabled the design of soft robots with sophisticated capabilities, such as jumping, complex 3D movements, gripping and releasing. In this Review, we examine the essential soft material properties for different elements of soft robots, highlighting the most relevant polymer systems. Advantages and limitations of different additive manufacturing processes, including 3D printing, fused deposition modelling, direct ink writing, selective laser sintering, inkjet printing and stereolithography, are discussed, and the different techniques are investigated for their application in soft robotic fabrication. Finally, we explore integrated robotic systems and give an outlook for the future of the field and remaining challenges.

Semiconductor nanowires: A platform for nanoscience and nanotechnology

PubMed Central

Lieber, Charles M.

2012-01-01

Advances in nanoscience and nanotechnology critically depend on the development of nanostructures whose properties are controlled during synthesis. We focus on this critical concept using semiconductor nanowires, which provide the capability through design and rational synthesis to realize unprecedented structural and functional complexity in building blocks as a platform material. First, a brief review of the synthesis of complex modulated nanowires in which rational design and synthesis can be used to precisely control composition, structure, and, most recently, structural topology is discussed. Second, the unique functional characteristics emerging from our exquisite control of nanowire materials are illustrated using several selected examples from nanoelectronics and nano-enabled energy. Finally, the remarkable power of nanowire building blocks is further highlighted through their capability to create unprecedented, active electronic interfaces with biological systems. Recent work pushing the limits of both multiplexed extracellular recording at the single-cell level and the first examples of intracellular recording is described, as well as the prospects for truly blurring the distinction between nonliving nanoelectronic and living biological systems. PMID:22707850

Using Different Examples of Natural Selection When Teaching Biology.

ERIC Educational Resources Information Center

Perry, Robert T.

1993-01-01

Describes the following examples of natural selection for use in science instruction: sickle-cell anemia and human beings, clogged crabs, the rounding of the human head, shell color in land snails, pollinator behavior and flower color, copper tolerance in a grass, lizards and quick change, and Darwin's finches. (PR)

Learning from Comparing Multiple Examples: On the Dilemma of "Similar" or "Different"

ERIC Educational Resources Information Center

Guo, Jian-Peng; Pang, Ming Fai; Yang, Ling-Yan; Ding, Yi

2012-01-01

Although researchers have demonstrated that studying multiple examples is more effective than studying one example to facilitate learning, the principles found in the literature for designing multiple examples remain ambiguous. This paper reviews variation theory research on example design which sheds light on unclear issues regarding the effects…

Bilabiate Flowers: The Ultimate Response to Bees?

PubMed Central

Westerkamp, Christian; Claßen-Bockhoff, Regine

2007-01-01

Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combined with personal observations collected during the last 25 years, coupled with knowledge from the literature. New functional terms are introduced that are independent of morphological and taxonomic associations. Key Results Bilabiate constructions occur in at least 38 angiosperm families. They are characterized by dorsiventral organization and dorsal pollen transfer. They are most often realised on the level of a single flower, but may also be present in an inflorescence or as part of a so-called ‘walk-around flower’. Interestingly, in functional terms all nototribic blossoms represent bilabiate constructions. The great majority of specialized bee-flowers can thus be included under bilabiate and keel blossoms. The syndrome introduced here, however, also paves the way for the inclusion of larger animals such as birds and bats. The most important evolutionary trends appear to be in the saving of pollen and the precision of its transfer. With special reference to the Lamiales, selected examples of bilabiate flowers are presented and their functional significance is discussed. Conclusions Bilabiate blossoms protect their pollen against pollen-collecting bees and at the same time render their pollination more precisely. The huge diversity of realised forms indicate the high selection pressure towards the bilabiate syndrome. As bees are very inventive, however, bilabiate constructions will not represent the ultimate response to bees. PMID:17652341

From concepts, theory, and evidence of heterogeneity of treatment effects to methodological approaches: a primer

PubMed Central

2012-01-01

Implicit in the growing interest in patient-centered outcomes research is a growing need for better evidence regarding how responses to a given intervention or treatment may vary across patients, referred to as heterogeneity of treatment effect (HTE). A variety of methods are available for exploring HTE, each associated with unique strengths and limitations. This paper reviews a selected set of methodological approaches to understanding HTE, focusing largely but not exclusively on their uses with randomized trial data. It is oriented for the “intermediate” outcomes researcher, who may already be familiar with some methods, but would value a systematic overview of both more and less familiar methods with attention to when and why they may be used. Drawing from the biomedical, statistical, epidemiological and econometrics literature, we describe the steps involved in choosing an HTE approach, focusing on whether the intent of the analysis is for exploratory, initial testing, or confirmatory testing purposes. We also map HTE methodological approaches to data considerations as well as the strengths and limitations of each approach. Methods reviewed include formal subgroup analysis, meta-analysis and meta-regression, various types of predictive risk modeling including classification and regression tree analysis, series of n-of-1 trials, latent growth and growth mixture models, quantile regression, and selected non-parametric methods. In addition to an overview of each HTE method, examples and references are provided for further reading. By guiding the selection of the methods and analysis, this review is meant to better enable outcomes researchers to understand and explore aspects of HTE in the context of patient-centered outcomes research. PMID:23234603

Phage display and molecular imaging: expanding fields of vision in living subjects.

PubMed

Cochran, R; Cochran, Frank

2010-01-01

In vivo molecular imaging enables non-invasive visualization of biological processes within living subjects, and holds great promise for diagnosis and monitoring of disease. The ability to create new agents that bind to molecular targets and deliver imaging probes to desired locations in the body is critically important to further advance this field. To address this need, phage display, an established technology for the discovery and development of novel binding agents, is increasingly becoming a key component of many molecular imaging research programs. This review discusses the expanding role played by phage display in the field of molecular imaging with a focus on in vivo applications. Furthermore, new methodological advances in phage display that can be directly applied to the discovery and development of molecular imaging agents are described. Various phage library selection strategies are summarized and compared, including selections against purified target, intact cells, and ex vivo tissue, plus in vivo homing strategies. An outline of the process for converting polypeptides obtained from phage display library selections into successful in vivo imaging agents is provided, including strategies to optimize in vivo performance. Additionally, the use of phage particles as imaging agents is also described. In the latter part of the review, a survey of phage-derived in vivo imaging agents is presented, and important recent examples are highlighted. Other imaging applications are also discussed, such as the development of peptide tags for site-specific protein labeling and the use of phage as delivery agents for reporter genes. The review concludes with a discussion of how phage display technology will continue to impact both basic science and clinical applications in the field of molecular imaging.

Rapid recent human evolution and the accumulation of balanced genetic polymorphisms.

PubMed

Wills, Christopher

2011-01-01

All evolutionary change can be traced to alterations in allele frequencies in populations over time. DNA sequencing on a massive scale now permits us to follow the genetic consequences as our species has diverged from our close relatives and as we have colonized different parts of the world and adapted to them. But it has been difficult to disentangle natural selection from many other factors that alter frequencies. These factors include mutation and intragenic reciprocal recombination, gene conversion, segregation distortion, random drift, and gene flow between populations (these last two are greatly influenced by splits and coalescences of populations over time). The first part of this review examines recent studies that have had some success in dissecting out the role of natural selection, especially in humans and Drosophila. Among many examples, these studies include those that have followed the rapid evolution of traits that may permit adaptation to high altitude in Tibetan and Andean populations. In some cases, directional selection has been so strong that it may have swept alleles close to fixation in the span of a few thousand years, a rapidity of change that is also sometimes encountered in other organisms. The second part of the review summarizes data showing that remarkably few alleles have been carried completely to fixation during our recent evolution. Some of the alleles that have not reached fixation may be approaching new internal equilibria, which would indicate polymorphisms that are maintained by balancing selection. Finally, the review briefly examines why genetic polymorphisms, particularly those that are maintained by negative frequency dependence, are likely to have played an important role in the evolution of our species. A method is suggested for measuring the contribution of these polymorphisms to our gene pool. Such polymorphisms may add to the ability of our species to adapt to our increasingly complex and challenging environment. © Mary Ann Liebert, Inc.

The use of lactic acid-producing, malic acid-producing, or malic acid-degrading yeast strains for acidity adjustment in the wine industry.

PubMed

Su, Jing; Wang, Tao; Wang, Yun; Li, Ying-Ying; Li, Hua

2014-03-01

In an era of economic globalization, the competition among wine businesses is likely to get tougher. Biotechnological innovation permeates the entire world and intensifies the severity of the competition of the wine industry. Moreover, modern consumers preferred individualized, tailored, and healthy and top quality wine products. Consequently, these two facts induce large gaps between wine production and wine consumption. Market-orientated yeast strains are presently being selected or developed for enhancing the core competitiveness of wine enterprises. Reasonable biological acidity is critical to warrant a high-quality wine. Many wild-type acidity adjustment yeast strains have been selected all over the world. Moreover, mutation breeding, metabolic engineering, genetic engineering, and protoplast fusion methods are used to construct new acidity adjustment yeast strains to meet the demands of the market. In this paper, strategies and concepts for strain selection or improvement methods were discussed, and many examples based upon selected studies involving acidity adjustment yeast strains were reviewed. Furthermore, the development of acidity adjustment yeast strains with minimized resource inputs, improved fermentation, and enological capabilities for an environmentally friendly production of healthy, top quality wine is presented.

Selective forces on origin, adaptation and reduction of tympanal ears in insects.

PubMed

Strauß, Johannes; Stumpner, Andreas

2015-01-01

Insect ears evolved many times independently. As a consequence, a striking diversity exists in the location, construction and behavioural implementation of ears. In this review, we first summarise what is known about the evolutionary origin of ears and the presumed precursor organs in the various insect groups. Thereafter, we focus on selective forces for making and keeping an ear: we discuss detecting and localising predators and conspecifics, including establishing new "private" channels for intraspecific communication. More advanced aspects involve judging the distance of conspecifics, or assessing individual quality from songs which makes auditory processing a means for exerting sexual selection on mating partners. We try to identify negative selective forces, mainly in the context of energy expenditure for developing and keeping an ear, but also in conjunction with acoustic communication, which incorporates risks like eavesdropping by predators and parasitoids. We then discuss balancing pressures, which might oppose optimising an ear for a specific task (when it serves different functions, for example). Subsequently, we describe various scenarios that might have led to a reduction or complete loss of ears in evolution. Finally, we describe cases of sex differences in ears and potential reasons for their appearance.

Why do some animals mate with one partner rather than many? A review of causes and consequences of monogamy.

PubMed

Kvarnemo, Charlotta

2018-04-23

Why do some animals mate with one partner rather than many? Here, I investigate factors related to (i) spatial constraints (habitat limitation, mate availability), (ii) time constraints (breeding synchrony, length of breeding season), (iii) need for parental care, and (iv) genetic compatibility, to see what support can be found in different taxa regarding the importance of these factors in explaining the occurrence of monogamy, whether shown by one sex (monogyny or monandry) or by both sexes (mutual monogamy). Focusing on reproductive rather than social monogamy whenever possible, I review the empirical literature for birds, mammals and fishes, with occasional examples from other taxa. Each of these factors can explain mating patterns in some taxa, but not in all. In general, there is mixed support for how well the factors listed above predict monogamy. The factor that shows greatest support across taxa is habitat limitation. By contrast, while a need for parental care might explain monogamy in freshwater fishes and birds, there is clear evidence that this is not the case in marine fishes and mammals. Hence, reproductive monogamy does not appear to have a single overriding explanation, but is more taxon specific. Genetic compatibility is a promising avenue for future work likely to improve our understanding of monogamy and other mating patterns. I also discuss eight important consequences of reproductive monogamy: (i) parentage, (ii) parental care, (iii) eusociality and altruism, (iv) infanticide, (v) effective population size, (vi) mate choice before mating, (vii) sexual selection, and (viii) sexual conflict. Of these, eusociality and infanticide have been subject to debate, briefly summarised herein. A common expectation is that monogamy leads to little sexual conflict and no or little sexual selection. However, as reviewed here, sexual selection can be substantial under mutual monogamy, and both sexes can be subject to such selection. Under long-term mutual monogamy, mate quality is obviously more important than mate numbers, which in turn affects the need for pre-mating mate choice. Overall, I conclude that, despite much research on genetic mating patterns, reproductive monogamy is still surprisingly poorly understood and further experimental and comparative work is needed. This review identifies several areas in need of more data and also proposes new hypotheses to test. © 2018 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.

Using Ensemble Decisions and Active Selection to Improve Low-Cost Labeling for Multi-View Data

NASA Technical Reports Server (NTRS)

Rebbapragada, Umaa; Wagstaff, Kiri L.

2011-01-01

This paper seeks to improve low-cost labeling in terms of training set reliability (the fraction of correctly labeled training items) and test set performance for multi-view learning methods. Co-training is a popular multiview learning method that combines high-confidence example selection with low-cost (self) labeling. However, co-training with certain base learning algorithms significantly reduces training set reliability, causing an associated drop in prediction accuracy. We propose the use of ensemble labeling to improve reliability in such cases. We also discuss and show promising results on combining low-cost ensemble labeling with active (low-confidence) example selection. We unify these example selection and labeling strategies under collaborative learning, a family of techniques for multi-view learning that we are developing for distributed, sensor-network environments.

Safety in surgery: is selection the missing link?

PubMed

Paice, Alistair G; Aggarwal, Rajesh; Darzi, Ara

2010-09-01

Health care providers comprise an example of a "high risk organization." Safety failings within these organizations have the potential to cause significant public harm. Significant safety improvements in other high risk organizations such as the aviation industry have led to the concept of a high reliability organization (HRO)--a high risk organization that has enjoyed a prolonged safety record. A strong organizational culture is common to all successful HROs, encompassing powerful systems of selection and training. Aircrew selection processes provide a good example of this and are examined in detail in this article using the Royal Air Force process as an example. If the lessons of successful HROs are to be applied to health care organizations, candidate selection to specialties such as surgery must become more objective and robust. Other HROs can provide valuable lessons in how this may be approached.

A short guide to peer-reviewed, MEDLINE-indexed complementary and alternative medicine journals.

PubMed

Morgan, Sherry; Littman, Lynn; Palmer, Christina; Singh, Gurneet; LaRiccia, Patrick J

2012-01-01

Complementary and alternative medicine (CAM) comprises a multitude of disciplines, for example, acupuncture, ayurvedic medicine, biofeedback, herbal medicine, and homeopathic medicine. While research on CAM interventions has increased and the CAM literature has proliferated since the mid-1990s, a number of our colleagues have expressed difficulties in deciding where to publish CAM articles. In response, we created a short guide to peer-reviewed MEDLINE-indexed journals that publish CAM articles. We examined numerous English-language sources to identify titles that met our criteria, whether specific to or overlapping CAM. A few of the resources in which we found the journal titles that we included are Alternative Medicine Foundation, American Holistic Nurses Association, CINAHL/Nursing Database, Journal Citation Reports database, MEDLINE, PubMed, and Research Council for Complementary Medicine. We organized the 69 selected titles for easy use by creating 2 user-friendly tables, one listing titles in alphabetical order and one listing them in topical categories. A few examples of the topical categories are Acupuncture, CAM (general), Chinese Medicine, Herbal/Plant/Phytotherapy, Neuroscience/Psychology, Nursing/Clinical Care. Our study is the first to list general CAM journals, specialty CAM journals, and overlapping mainstream journals that are peer reviewed, in English, and indexed in MEDLINE. Our goal was to assist both authors seeking publication and mainstream journal editors who receive an overabundance of publishable articles but must recommend that authors seek publication elsewhere due to space and priority issues. Publishing in journals indexed by and included in MEDLINE (or PubMed) ensures that citations to articles will be found easily. Copyright © 2012 Lippincott Williams & Wilkins.

Funding Intensive Care - Approaches in Systems Using Diagnosis-Related Groups.

PubMed

Ettelt, Stefanie; Nolte, Ellen

2012-01-01

This article summarizes a review of approaches to funding intensive care in health systems that use activity-based payment mechanisms based on diagnosis-related groups (DRGs) to reimburse hospital care in Australia (Victoria), Denmark, France, Germany, Italy, Spain, Sweden and the United States (Medicare). The study aims to inform the current debate about options for funding intensive care services for adults, children and newborns in England. Mechanisms of funding intensive care services tend to fall into three broad categories: (1) those that fund intensive care through DRGs as part of one episode of hospital care only (US Medicare, Germany, selected regions in Sweden and Italy; (2) those that use DRGs in combination with co-payments (Victoria, France); and (3) those that exclude intensive care from DRG funding and use an alternative form of payment, for example global budgets (Spain) or per diems (South Australia). The review suggests that there is no obvious example of "best practice" or dominant approach used by a majority of systems. Each approach has advantages and disadvantages, particularly in relation to the financial risk involved in providing intensive care. While the risk of underfunding intensive care may be highest in systems that apply DRGs to the entire episode of hospital care, including intensive care, concerns about potential underfunding were voiced in all systems reviewed here. Arrangements for additional funding in the form of co-payments or surcharges may reduce the risk of underfunding. However, these approaches also face the difficulty of determining the appropriate level of (additional) payment and balancing the incentive effect arising from higher payment.

How Imaging Can Impact Clinical Trial Design: Molecular Imaging as a Biomarker for Targeted Cancer Therapy.

PubMed

Mankoff, David A; Farwell, Michael D; Clark, Amy S; Pryma, Daniel A

2015-01-01

The ability to measure biochemical and molecular processes to guide cancer treatment represents a potentially powerful tool for trials of targeted cancer therapy. These assays have traditionally been performed by analysis of tissue samples. However, more recently, functional and molecular imaging has been developed that is capable of in vivo assays of cancer biochemistry and molecular biology and is highly complementary to tissue-based assays. Cancer imaging biomarkers can play a key role in increasing the efficacy and efficiency of therapeutic clinical trials and also provide insight into the biologic mechanisms that bring about a therapeutic response. Future progress will depend on close collaboration between imaging scientists and cancer physicians and on public and commercial sponsors, to take full advantage of what imaging has to offer for clinical trials of targeted cancer therapy. This review will provide examples of how molecular imaging can inform targeted cancer clinical trials and clinical decision making by (1) measuring regional expression of the therapeutic target, (2) assessing early (pharmacodynamic) response to treatment, and (3) predicting therapeutic outcome. The review includes a discussion of basic principles of molecular imaging biomarkers in cancer, with an emphasis on those methods that have been tested in patients. We then review clinical trials designed to evaluate imaging tests as integrated markers embedded in a therapeutic clinical trial with the goal of validating the imaging tests as integral markers that can aid patient selection and direct response-adapted treatment strategies. Examples of recently completed multicenter trials using imaging biomarkers are highlighted.

The EULAR Outcome Measures Library: development and an example from a systematic review for systemic lupus erythematous instruments.

PubMed

Castrejon, I; Carmona, L; Agrinier, N; Andres, M; Briot, K; Caron, M; Christensen, R; Consolaro, A; Curbelo, R; Ferrer, Montserrat; Foltz, Violaine; Gonzalez, C; Guillemin, F; Machado, P M; Prodinger, Birgit; Ravelli, A; Scholte-Voshaar, M; Uhlig, T; van Tuyl, L H D; Zink, A; Gossec, L

2015-01-01

Patient reported outcomes (PROs) are relevant in rheumatology. Variable accessibility and validity of commonly used PROs are obstacles to homogeneity in evidence synthesis. The objective of this project was to provide a comprehensive library of "validated PROs". A launch meeting with rheumatologists, PROs methodological experts, and patients, was held to define the library's aims and scope, and basic requirements. To feed the library we performed systematic reviews on selected diseases and domains. Relevant information on PROs was collected using standardised data collection forms based on the COSMIN checklist. The EULAR Outcomes Measures Library (OML), whose aims are to provide and to advise on PROs on a user-friendly manner albeit based on scientific grounds, has been launched and made accessible to all. PROs currently included cover any domain and, are generic or specifically target to the following diseases: rheumatoid arthritis, osteoarthritis, spondyloarthritis, low back pain, systemic lupus erythematosus, gout, osteoporosis, juvenile idiopathic arthritis, and fibromyalgia. Up to 236 instruments (106 generic and 130 specific) have been identified, evaluated, and included. The systematic review for SLE, which yielded 10 specific instruments, is presented here as an example. The OML website includes, for each PRO, information on the construct being measured and the extent of validation, recommendations for use, and available versions; it also contains a glossary on common validation terms. The OML is an in progress library led by rheumatologists, related professionals and patients, that will help to better understand and apply PROs in rheumatic and musculoskeletal diseases.

When Does an Argument Use a Generic Example?

ERIC Educational Resources Information Center

Yopp, David A.; Ely, Rob

2016-01-01

We offer criteria that an observer can use to determine whether an argument that uses an example to argue for a general claim appeals to that example generically. We review existing literature on generic example and note the strengths of each contribution, as well as inconsistencies among uses of the term. We offer several examples from the…

How sexual selection can drive the evolution of costly sperm ornamentation

NASA Astrophysics Data System (ADS)

Lüpold, Stefan; Manier, Mollie K.; Puniamoorthy, Nalini; Schoff, Christopher; Starmer, William T.; Luepold, Shannon H. Buckley; Belote, John M.; Pitnick, Scott

2016-05-01

Post-copulatory sexual selection (PSS), fuelled by female promiscuity, is credited with the rapid evolution of sperm quality traits across diverse taxa. Yet, our understanding of the adaptive significance of sperm ornaments and the cryptic female preferences driving their evolution is extremely limited. Here we review the evolutionary allometry of exaggerated sexual traits (for example, antlers, horns, tail feathers, mandibles and dewlaps), show that the giant sperm of some Drosophila species are possibly the most extreme ornaments in all of nature and demonstrate how their existence challenges theories explaining the intensity of sexual selection, mating-system evolution and the fundamental nature of sex differences. We also combine quantitative genetic analyses of interacting sex-specific traits in D. melanogaster with comparative analyses of the condition dependence of male and female reproductive potential across species with varying ornament size to reveal complex dynamics that may underlie sperm-length evolution. Our results suggest that producing few gigantic sperm evolved by (1) Fisherian runaway selection mediated by genetic correlations between sperm length, the female preference for long sperm and female mating frequency, and (2) longer sperm increasing the indirect benefits to females. Our results also suggest that the developmental integration of sperm quality and quantity renders post-copulatory sexual selection on ejaculates unlikely to treat male-male competition and female choice as discrete processes.

Selection of examples in case-based computer-aided decision systems

PubMed Central

Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.

2013-01-01

Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system’s diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system’s performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2–4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system. PMID:18854606

Quasi-experimental study designs series-paper 8: identifying quasi-experimental studies to inform systematic reviews.

PubMed

Glanville, Julie; Eyers, John; Jones, Andrew M; Shemilt, Ian; Wang, Grace; Johansen, Marit; Fiander, Michelle; Rothstein, Hannah

2017-09-01

This article reviews the available evidence and guidance on methods to identify reports of quasi-experimental (QE) studies to inform systematic reviews of health care, public health, international development, education, crime and justice, and social welfare. Research, guidance, and examples of search strategies were identified by searching a range of databases, key guidance documents, selected reviews, conference proceedings, and personal communication. Current practice and research evidence were summarized. Four thousand nine hundred twenty-four records were retrieved by database searches, and additional documents were obtained by other searches. QE studies are challenging to identify efficiently because they have no standardized nomenclature and may be indexed in various ways. Reliable search filters are not available. There is a lack of specific resources devoted to collecting QE studies and little evidence on where best to search. Searches to identify QE studies should search a range of resources and, until indexing improves, use strategies that focus on the topic rather than the study design. Better definitions, better indexing in databases, prospective registers, and reporting guidance are required to improve the retrieval of QE studies and promote systematic reviews of what works based on the evidence from such studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Apoptosis in the homeostasis of the immune system and in human immune mediated diseases.

PubMed

Giovannetti, A; Pierdominici, M; Di Iorio, A; Cianci, R; Murdaca, G; Puppo, F; Pandolfi, F; Paganelli, R

2008-01-01

The immune system has evolved sophisticated mechanisms controlling the development of responses to dangerous antigens while avoiding unnecessary attacks to innocuous, commensal or self antigens. The risk of autoimmunity is continuously checked and balanced against the risk of succumbing to exogenous infectious agents. It is therefore of paramount importance to understand the molecular events linking the breakdown of tolerance and the development of immunodeficiency. Apoptotic mechanisms are used to regulate the development of thymocytes, the shaping of T cell repertoire, its selection and the coordinate events leading to immune responses in the periphery. Moreover, they are at the heart of the homeostatic controls restoring T cell numbers and establishing T cell memory. T lymphocytes shift continuously from survival to death signals to ensure immune responsiveness without incurring in autoimmune damage. In this review we shall consider some key facts on the relationship of lymphopenia to autoreactivity, the mechanisms controlling positive and negative selection in the thymus, the role of apoptosis in selected primary immunodeficiency states and in systemic and organ-specific autoimmunity, with examples from human diseases and their animal models.

Darwin and Genetics

PubMed Central

Charlesworth, Brian; Charlesworth, Deborah

2009-01-01

Darwin's theory of natural selection lacked an adequate account of inheritance, making it logically incomplete. We review the interaction between evolution and genetics, showing how, unlike Mendel, Darwin's lack of a model of the mechanism of inheritance left him unable to interpret his own data that showed Mendelian ratios, even though he shared with Mendel a more mathematical and probabilistic outlook than most biologists of his time. Darwin's own “pangenesis” model provided a mechanism for generating ample variability on which selection could act. It involved, however, the inheritance of characters acquired during an organism's life, which Darwin himself knew could not explain some evolutionary situations. Once the particulate basis of genetics was understood, it was seen to allow variation to be passed intact to new generations, and evolution could then be understood as a process of changes in the frequencies of stable variants. Evolutionary genetics subsequently developed as a central part of biology. Darwinian principles now play a greater role in biology than ever before, which we illustrate with some examples of studies of natural selection that use DNA sequence data and with some recent advances in answering questions first asked by Darwin. PMID:19933231

Toward a clarification of the taxonomy of "bias" in epidemiology textbooks.

PubMed

Schwartz, Sharon; Campbell, Ulka B; Gatto, Nicolle M; Gordon, Kirsha

2015-03-01

Epidemiology textbooks typically divide biases into 3 general categories-confounding, selection bias, and information bias. Despite the ubiquity of this categorization, authors often use these terms to mean different things. This hinders communication among epidemiologists and confuses students who are just learning about the field. To understand the sources of this problem, we reviewed current general epidemiology textbooks to examine how the authors defined and categorized biases. We found that much of the confusion arises from different definitions of "validity" and from a mixing of 3 overlapping organizational features in defining and differentiating among confounding, selection bias, and information bias: consequence, the result of the problem; cause, the processes that give rise to the problem; and cure, how these biases can be addressed once they occur. By contrast, a consistent taxonomy would provide (1) a clear and consistent definition of what unites confounding, selection bias, and information bias and (2) a clear articulation and consistent application of the feature that distinguishes these categories. Based on a distillation of these textbook discussions, we provide an example of a taxonomy that we think meets these criteria.

Measuring social science concepts in pharmacy education research: From definition to item analysis of self-report instruments.

PubMed

Cor, M Ken

Interpreting results from quantitative research can be difficult when measures of concepts are constructed poorly, something that can limit measurement validity. Social science steps for defining concepts, guidelines for limiting construct-irrelevant variance when writing self-report questions, and techniques for conducting basic item analysis are reviewed to inform the design of instruments to measure social science concepts in pharmacy education research. Based on a review of the literature, four main recommendations emerge: These include: (1) employ a systematic process of conceptualization to derive nominal definitions; (2) write exact and detailed operational definitions for each concept, (3) when creating self-report questionnaires, write statements and select scales to avoid introducing construct-irrelevant variance (CIV); and (4) use basic item analysis results to inform instrument revision. Employing recommendations that emerge from this review will strengthen arguments to support measurement validity which in turn will support the defensibility of study finding interpretations. An example from pharmacy education research is used to contextualize the concepts introduced. Copyright © 2017 Elsevier Inc. All rights reserved.

Methods for Generating Complex Networks with Selected Structural Properties for Simulations: A Review and Tutorial for Neuroscientists

PubMed Central

Prettejohn, Brenton J.; Berryman, Matthew J.; McDonnell, Mark D.

2011-01-01

Many simulations of networks in computational neuroscience assume completely homogenous random networks of the Erdös–Rényi type, or regular networks, despite it being recognized for some time that anatomical brain networks are more complex in their connectivity and can, for example, exhibit the “scale-free” and “small-world” properties. We review the most well known algorithms for constructing networks with given non-homogeneous statistical properties and provide simple pseudo-code for reproducing such networks in software simulations. We also review some useful mathematical results and approximations associated with the statistics that describe these network models, including degree distribution, average path length, and clustering coefficient. We demonstrate how such results can be used as partial verification and validation of implementations. Finally, we discuss a sometimes overlooked modeling choice that can be crucially important for the properties of simulated networks: that of network directedness. The most well known network algorithms produce undirected networks, and we emphasize this point by highlighting how simple adaptations can instead produce directed networks. PMID:21441986

Developmental Origins of Health and Disease: Environmental Exposures

PubMed Central

Swanson, James M.; Entringer, Sonja; Buss, Claudia; Wadhwa, Pathik D.

2010-01-01

The developmental origins of health and disease (DOHaD) approach has evolved over the past 20 years, and the current hypothesis proposes that fetal adaptations to intrauterine and maternal conditions during development shape structure and function of organs. Here we present a review of some environmental exposures that may trigger fetal maladaptations in these processes, including three examples: exposures to tobacco smoke, antidepressant medication, and folic acid deficits in the food supply. We provide a selected review of current research on the effects of each of these exposures on fetal development and birth outcomes, and use the DOHaD approach to suggest how these exposures may alter long-term outcomes. In the interpretation of this literature, we review the evidence of gene–environment interactions based on evaluation of biological pathways and evidence that some exposures to the fetus may be moderated by maternal and fetal genotypes. Finally, we use the design of the National Children’s Study (now in progress) to propose how the DOHaD approach could be used to address questions that have emerged in this area that are relevant to reproductive medicine and subsequent health outcomes. PMID:19711249

Applicability of bioanalysis of multiple analytes in drug discovery and development: review of select case studies including assay development considerations.

PubMed

Srinivas, Nuggehally R

2006-05-01

The development of sound bioanalytical method(s) is of paramount importance during the process of drug discovery and development culminating in a marketing approval. Although the bioanalytical procedure(s) originally developed during the discovery stage may not necessarily be fit to support the drug development scenario, they may be suitably modified and validated, as deemed necessary. Several reviews have appeared over the years describing analytical approaches including various techniques, detection systems, automation tools that are available for an effective separation, enhanced selectivity and sensitivity for quantitation of many analytes. The intention of this review is to cover various key areas where analytical method development becomes necessary during different stages of drug discovery research and development process. The key areas covered in this article with relevant case studies include: (a) simultaneous assay for parent compound and metabolites that are purported to display pharmacological activity; (b) bioanalytical procedures for determination of multiple drugs in combating a disease; (c) analytical measurement of chirality aspects in the pharmacokinetics, metabolism and biotransformation investigations; (d) drug monitoring for therapeutic benefits and/or occupational hazard; (e) analysis of drugs from complex and/or less frequently used matrices; (f) analytical determination during in vitro experiments (metabolism and permeability related) and in situ intestinal perfusion experiments; (g) determination of a major metabolite as a surrogate for the parent molecule; (h) analytical approaches for universal determination of CYP450 probe substrates and metabolites; (i) analytical applicability to prodrug evaluations-simultaneous determination of prodrug, parent and metabolites; (j) quantitative determination of parent compound and/or phase II metabolite(s) via direct or indirect approaches; (k) applicability in analysis of multiple compounds in select disease areas and/or in clinically important drug-drug interaction studies. A tabular representation of select examples of analysis is provided covering areas of separation conditions, validation aspects and applicable conclusion. A limited discussion is provided on relevant aspects of the need for developing bioanalytical procedures for speedy drug discovery and development. Additionally, some key elements such as internal standard selection, likely issues of mass detection, matrix effect, chiral aspects etc. are provided for consideration during method development.

Brazilian and Mexican experiences in the study of incipient domestication.

PubMed

Lins Neto, Ernani Machado de Freitas; Peroni, Nivaldo; Casas, Alejandro; Parra, Fabiola; Aguirre, Xitlali; Guillén, Susana; Albuquerque, Ulysses Paulino

2014-04-02

Studies of domestication enables a better understanding of human cultures, landscape changes according to peoples' purposes, and evolutionary consequences of human actions on biodiversity. This review aimed at discussing concepts, hypotheses, and current trends in studies of domestication of plants, using examples of cases studied in regions of Mesoamerica and Brazil. We analyzed trends of ethnobiological studies contributing to document processes of domestication and to establish criteria for biodiversity conservation based on traditional ecological knowledge. Based on reviewing our own and other authors' studies we analyzed management patterns and evolutionary trends associated to domestication occurring at plant populations and landscape levels. Particularly, we systematized information documenting: ethnobotanical aspects about plant management and artificial selection mechanisms, morphological consequences of plant management, population genetics of wild and managed plant populations, trends of change in reproduction systems of plants associated to management, and other ecological and physiological aspects influenced by management and domestication. Based on the analysis of study cases of 20 native species of herbs, shrubs and trees we identified similar criteria of artificial selection in different cultural contexts of Mexico and Brazil. Similar evolutionary trends were also identified in morphology (selection in favor of gigantism of useful and correlated parts); organoleptic characteristics such as taste, toxicity, color, texture; reproductive biology, mainly breeding system, phenological changes, and population genetics aspects, maintenance or increasing of genetic diversity in managed populations, high gene flow with wild relatives and low structure maintained by artificial selection. Our review is a first attempt to unify research methods for analyzing a high diversity of processes. Further research should emphasize deeper analyses of contrasting and diverse cultural and ecological contexts for a better understanding of evolution under incipient processes of domestication. Higher research effort is particularly required in Brazil, where studies on this topic are scarcer than in Mexico but where diversity of human cultures managing their also high plant resources diversity offer high potential for documenting the diversity of mechanisms of artificial selection and evolutionary trends. Comparisons and evaluations of incipient domestication in the regions studied as well as the Andean area would significantly contribute to understanding origins and diffusion of the experience of managing and domesticating plants.

Stimuli-responsive polymeric nanocarriers for the controlled transport of active compounds: concepts and applications.

PubMed

Fleige, Emanuel; Quadir, Mohiuddin A; Haag, Rainer

2012-06-15

The use of polymeric nanocarriers to transport active compounds like small-molecular drugs, peptides, or genes found an increased attention throughout the different fields of natural sciences. Not only that these nanocarriers enhance the properties of already existing drugs in terms of solubility, bioavailability, and prolonged circulation times, furthermore they can be tailor-made in such a manner that they selectively release their cargo at the desired site of action. For the triggered release, these so-called smart drug delivery systems are designed to react on certain stimuli like pH, temperature, redox potential, enzymes, light, and ultrasound. Some of these stimuli are naturally occurring in vivo, for example the difference in pH in different cellular compartments while others are caused by the disease, which is to be treated, like differences in pH and temperature in some tumor tissues. Other external applied stimuli, like light and ultrasound, allow the temporal and spatial control of the release, since they are not triggered by any biological event. This review gives a brief overview about some types of stimuli-responsive nanocarriers with the main focus on organic polymer-based systems. Furthermore, the different stimuli and the design of corresponding responsive nanocarriers will be discussed with the help of selected examples from the literature. Copyright © 2012 Elsevier B.V. All rights reserved.

Developmental Pathways Are Blueprints for Designing Successful Crops

PubMed Central

Trevaskis, Ben

2018-01-01

Genes controlling plant development have been studied in multiple plant systems. This has provided deep insights into conserved genetic pathways controlling core developmental processes including meristem identity, phase transitions, determinacy, stem elongation, and branching. These pathways control plant growth patterns and are fundamentally important to crop biology and agriculture. This review describes the conserved pathways that control plant development, using Arabidopsis as a model. Historical examples of how plant development has been altered through selection to improve crop performance are then presented. These examples, drawn from diverse crops, show how the genetic pathways controlling development have been modified to increase yield or tailor growth patterns to suit local growing environments or specialized crop management practices. Strategies to apply current progress in genomics and developmental biology to future crop improvement are then discussed within the broader context of emerging trends in plant breeding. The ways that knowledge of developmental processes and understanding of gene function can contribute to crop improvement, beyond what can be achieved by selection alone, are emphasized. These include using genome re-sequencing, mutagenesis, and gene editing to identify or generate novel variation in developmental genes. The expanding scope for comparative genomics, the possibility to engineer new developmental traits and new approaches to resolve gene–gene or gene–environment interactions are also discussed. Finally, opportunities to integrate fundamental research and crop breeding are highlighted. PMID:29922318

Developmental Pathways Are Blueprints for Designing Successful Crops.

PubMed

Trevaskis, Ben

2018-01-01

Genes controlling plant development have been studied in multiple plant systems. This has provided deep insights into conserved genetic pathways controlling core developmental processes including meristem identity, phase transitions, determinacy, stem elongation, and branching. These pathways control plant growth patterns and are fundamentally important to crop biology and agriculture. This review describes the conserved pathways that control plant development, using Arabidopsis as a model. Historical examples of how plant development has been altered through selection to improve crop performance are then presented. These examples, drawn from diverse crops, show how the genetic pathways controlling development have been modified to increase yield or tailor growth patterns to suit local growing environments or specialized crop management practices. Strategies to apply current progress in genomics and developmental biology to future crop improvement are then discussed within the broader context of emerging trends in plant breeding. The ways that knowledge of developmental processes and understanding of gene function can contribute to crop improvement, beyond what can be achieved by selection alone, are emphasized. These include using genome re-sequencing, mutagenesis, and gene editing to identify or generate novel variation in developmental genes. The expanding scope for comparative genomics, the possibility to engineer new developmental traits and new approaches to resolve gene-gene or gene-environment interactions are also discussed. Finally, opportunities to integrate fundamental research and crop breeding are highlighted.

A new competency model for general practice: implications for selection, training, and careers.

PubMed

Patterson, Fiona; Tavabie, Abdol; Denney, MeiLing; Kerrin, Máire; Ashworth, Vicki; Koczwara, Anna; MacLeod, Sheona

2013-05-01

Recent structural and policy changes in the UK health service have significantly changed the job responsibilities for the GP role. To replicate a previous job analysis study to examine the relevance of current competency domains and selection criteria for doctors entering training. A multisource, multimethod approach comprising three phases: (1) stakeholder consultation (n = 205) using interviews, focus groups and behavioural observation of practising GPs; (2) a validation questionnaire based on results from phase 1 (n = 1082); followed by (3) an expert panel (n = 6) to review and confirm the final competency domains. Eleven competency domains were identified, which extends previous research findings. A new domain was identified called Leading for Continuing Improvement. Results show that, Empathy and Perspective Taking, Communication Skills, Clinical Knowledge and Expertise, and Professional Integrity are currently rated the most important domains. Results indicate a significant increase in ratings of importance for each domain in the future (P<0.001), except for Communication Skills and Empathy and Perspective Taking, which consistently remain high. The breadth of competencies required for GPs has increased significantly. GPs are now required to resolve competing tensions to be effective in their role, such as maintaining a patient focus while overseeing commissioning, with a potential ethical conflict between these aspects. Selection criteria remain largely unchanged but with increased priority in some domains (for example, Effective Teamworking). However, there is an urgent need to review the training provision arrangements to reflect the greater breadth of competencies now required.

Nonlinear Acoustics in Ultrasound Metrology and other Selected Applications.

PubMed

Lewin, Peter A

2010-01-01

A succinct background explaining why, initially, both the scientific community and industry were skeptical about the existence of the nonlinear (NL) wave propagation in tissue will be given and the design of an adequately wideband piezoelectric polymer hydrophone probe that was eventually used to verify that the 1-5 MHz probing wave then used in diagnostic ultrasound imaging was undergoing nonlinear distortion and generated harmonics in tissue will be discussed. The far-reaching implications of the advent of the piezoelectric PVDF polymer material will be reviewed and the advances in ultrasound metrology prompted by the regulatory agencies such as US Food and Drug Administration (FDA) and International Electrotechnical Commission (IEC) will be presented. These advances include the development of absolute calibration techniques for hydrophones along with the methods of accounting for spatial averaging corrections up to 100 MHz and the development of "point-receiver" hydrophone probes utilizing acousto-optic sensors. Next, selected therapeutic applications of nonlinear ultrasonics (NLU), including lithotripters will be briefly discussed. Also, the use of shock waves as pain relief tool and in abating penicillin resistant bacteria that develop rock hard "biofilm" that can be shattered by the finite amplitude wave will also be mentioned. The growing applications of NLU in cosmetic industry where it is used for redistribution and reduction of fatty tissue within the body will be briefly reviewed, and, finally, selected examples of NLU applications in retail and entertainment industry will also be pointed out.

Behaviors of cavefish offer insight into developmental evolution

PubMed Central

2015-01-01

SUMMARY Many developmental processes have evolved through natural selection, yet in only a few cases do we understand if and how a change of developmental process produces a benefit. For example, many studies in evolutionary biology have investigated the developmental mechanisms that lead to novel structures in an animal, but only a few have addressed if these structures actually benefit the animal at the behavioral level of prey hunting and mating. As such, this review discusses an animal's behavior as the integrated functional output of its evolved morphological and physiological traits. Specifically, we focus on recent findings about the blind Mexican cavefish, Astyanax mexicanus, for which clear relationships exist between its physical traits and ecosystem. This species includes two morphotypes: an eyed surface dweller versus many conspecific types of blind cave dwellers, some of which evolved independently; all of the blind subtypes derived from eyed surface dwellers. The blind cavefish evolved under clear selection pressures: food is sparse and darkness is perpetual. Simulating the major aspects of a cave ecosystem in the laboratory is relatively easy, so we can use this species to begin resolving the relationships between evolved traits and selection pressures—relationships which are more complex for other animals models. This review discusses the recent advances in cavefish research that have helped us establish some key relationships between morphological evolution and environmental shifts. Mol. Reprod. Dev. 82: 268–280, 2015. © 2015 Wiley Periodicals, Inc. PMID:25728684

Novel metals and metal complexes as platforms for cancer therapy.

PubMed

Frezza, Michael; Hindo, Sarmad; Chen, Di; Davenport, Andrew; Schmitt, Sara; Tomco, Dajena; Dou, Q Ping

2010-06-01

Metals are essential cellular components selected by nature to function in several indispensable biochemical processes for living organisms. Metals are endowed with unique characteristics that include redox activity, variable coordination modes, and reactivity towards organic substrates. Due to their reactivity, metals are tightly regulated under normal conditions and aberrant metal ion concentrations are associated with various pathological disorders, including cancer. For these reasons, coordination complexes, either as drugs or prodrugs, become very attractive probes as potential anticancer agents. The use of metals and their salts for medicinal purposes, from iatrochemistry to modern day, has been present throughout human history. The discovery of cisplatin, cis-[Pt(II) (NH(3))(2)Cl(2)], was a defining moment which triggered the interest in platinum(II)- and other metal-containing complexes as potential novel anticancer drugs. Other interests in this field address concerns for uptake, toxicity, and resistance to metallodrugs. This review article highlights selected metals that have gained considerable interest in both the development and the treatment of cancer. For example, copper is enriched in various human cancer tissues and is a co-factor essential for tumor angiogenesis processes. However the use of copper-binding ligands to target tumor copper could provide a novel strategy for cancer selective treatment. The use of nonessential metals as probes to target molecular pathways as anticancer agents is also emphasized. Finally, based on the interface between molecular biology and bioinorganic chemistry the design of coordination complexes for cancer treatment is reviewed and design strategies and mechanisms of action are discussed.

Nonlinear acoustics in ultrasound metrology and other selected applications

NASA Astrophysics Data System (ADS)

Lewin, Peter A.

2010-01-01

A succinct background explaining why, initially, both the scientific community and industry were skeptical about the existence of the nonlinear (NL) wave propagation in tissue will be given and the design of an adequately wideband piezoelectric polymer hydrophone probe that was eventually used to verify that the 1-5 MHz probing wave then used in diagnostic ultrasound imaging was undergoing nonlinear distortion and generated harmonics in tissue will be discussed. The far-reaching implications of the advent of the piezoelectric PVDF polymer material will be reviewed and the advances in ultrasound metrology prompted by the regulatory agencies such as US Food and Drug Administration (FDA) and International Electrotechnical Commission (IEC) will be presented. These advances include the development of absolute calibration techniques for hydrophones along with the methods of accounting for spatial averaging corrections up to 100 MHz and the development of 'point-receiver' hydrophone probes utilizing acousto-optic sensors. Next, selected therapeutic applications of nonlinear ultrasonics (NLU), including lithotripters will be briefly discussed. Also, the use of shock waves as pain relief tool and in abating penicillin resistant bacteria that develop rock hard 'biofilm' that can be shattered by the finite amplitude wave will also be mentioned. The growing applications of NLU in cosmetic industry where it is used for redistribution and reduction of fatty tissue within the body will be briefly reviewed, and, finally, selected examples of NLU applications in retail and entertainment industry will also be pointed out.

Whole-cell based hybrid materials for green energy production, environmental remediation and smart cell-therapy.

PubMed

Léonard, Alexandre; Dandoy, Philippe; Danloy, Emeric; Leroux, Grégory; Meunier, Christophe F; Rooke, Joanna C; Su, Bao-Lian

2011-02-01

This critical review highlights the advances that have been made over recent years in the domain of whole-cell immobilisation and encapsulation for applications relating to the environment and human health, particularly focusing on examples of photosynthetic plant cells, bacteria and algae as well as animal cells. Evidence that encapsulated photosynthetic cells remain active in terms of CO(2) sequestration and biotransformation (solar driven conversion of CO(2) into biofuels, drugs, fine chemicals etc.), coupled with the most recent advances made in the field of cell therapy, reveals the need to develop novel devices based on the preservation of living cells within abiotic porous frameworks. This review shall corroborate this statement by selecting precise examples that unambiguously demonstrate the necessity and the benefits of such smart materials. As will be described, the handling and exploitation of photosynthetic cells are enhanced by entrapment or encapsulation since the cells are physically separated from the liquid medium, thereby facilitating the recovery of the metabolites produced. In the case of animal cells, their encapsulation within a matrix is essential in order to create a physical barrier that can protect the cells auto-immune defenders upon implantation into a living body. For these two research axes, the key parameters that have to be kept in mind when designing hybrid materials will be identified, concentrating on essential aspects such as biocompatibility, mechanical strength and controlled porosity (264 references).

More Analytical Tools for Fluids Management in Space

NASA Astrophysics Data System (ADS)

Weislogel, Mark

Continued advances during the 2000-2010 decade in the analysis of a class of capillary-driven flows relevant to materials processing and fluids management aboard spacecraft have been made. The class of flows addressed concern combined forced and spontaneous capillary flows in complex containers with interior edges. Such flows are commonplace in space-based fluid systems and arise from the particular container geometry and wetting properties of the system. Important applications for this work include low-g liquid fill and/or purge operations and passive fluid phase separation operations, where the container (i.e. fuel tank, water processer, etc.) geometry possesses interior edges, and where quantitative information of fluid location, transients, flow rates, and stability is critical. Examples include the storage and handling of liquid propellants and cryogens, water conditioning for life support, fluid phase-change thermal systems, materials processing in the liquid state, on-orbit biofluids processing, among others. For a growing number of important problems, closed-form expressions to transient three-dimensional flows are possible that, as design tools, replace difficult, time-consuming, and rarely performed numerical calculations. An overview of a selection of solutions in-hand is presented with example problems solved. NASA drop tower, low-g aircraft, and ISS flight ex-periment results are employed where practical to buttress the theoretical findings. The current review builds on a similar review presented at COSPAR, 2002, for the approximate decade 1990-2000.

Atlas of Radiographic Features of Osteoarthritis of the Ankle and Hindfoot

PubMed Central

Kraus, Virginia Byers; Kilfoil, Terrence M; Hash, Thomas W.; McDaniel, Gary; Renner, Jordan B; Carrino, John A.; Adams, Samuel

2015-01-01

Objective To develop a radiographic atlas of osteoarthritis (OA) for use as a template and guide for standardized scoring of radiographic features of OA of the ankle and hindfoot joints. Method Under Institutional Review Board approval, ankle and hindfoot images were selected from a cohort study and from among cases that underwent ankle radiography during a 6-month period at Duke University Medical Center. Missing OA pathology was obtained through supplementation of cases with the assistance of a foot and ankle specialist in Orthopaedic surgery and a musculoskeletal radiologist. Images were obtained and reviewed without patient identifying information. Images went through multiple rounds of review and final images were selected by consensus of the study team. For intra-rater and inter-rater reliability, the kappa statistic was calculated for two readings by 3 musculoskeletal radiologists, a minimum of two weeks apart, of ankle and hindfoot radiographs from 30 anonymized subjects. Results The atlas demonstrates individual radiographic features (osteophyte and joint space narrowing) and Kellgren Lawrence grade for all aspects of the talocrural (ankle joint proper) and talocalcaneal (subtalar) joints. Reliability of scoring based on the atlas was quite good to excellent for most features indicated. Additional examples of ankle joint findings are illustrated including sclerosis, os trigonum, subchondral cysts and talar tilt. Conclusions It is anticipated that this atlas will assist with standardization of scoring of ankle and hindfoot OA by basic and clinical OA researchers. PMID:26318654

Atlas of radiographic features of osteoarthritis of the ankle and hindfoot.

PubMed

Kraus, V B; Kilfoil, T M; Hash, T W; McDaniel, G; Renner, J B; Carrino, J A; Adams, S

2015-12-01

To develop a radiographic atlas of osteoarthritis (OA) for use as a template and guide for standardized scoring of radiographic features of OA of the ankle and hindfoot joints. Under Institutional Review Board approval, ankle and hindfoot images were selected from a cohort study and from among cases that underwent ankle radiography during a 6-month period at Duke University Medical Center. Missing OA pathology was obtained through supplementation of cases with the assistance of a foot and ankle specialist in Orthopaedic surgery and a musculoskeletal radiologist. Images were obtained and reviewed without patient identifying information. Images went through multiple rounds of review and final images were selected by consensus of the study team. For intra-rater and inter-rater reliability, the kappa statistic was calculated for two readings by three musculoskeletal radiologists, a minimum of two weeks apart, of ankle and hindfoot radiographs from 30 anonymized subjects. The atlas demonstrates individual radiographic features (osteophyte and joint space narrowing (JSN)) and Kellgren-Lawrence grade for all aspects of the talocrural (ankle joint proper) and talocalcaneal (subtalar) joints. Reliability of scoring based on the atlas was quite good to excellent for most features indicated. Additional examples of ankle joint findings are illustrated including sclerosis, os trigonum, subchondral cysts and talar tilt. It is anticipated that this atlas will assist with standardization of scoring of ankle and hindfoot OA by basic and clinical OA researchers. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Using rapid reviews: an example from a study conducted to inform policy-making.

PubMed

O'Leary, Denise F; Casey, Mary; O'Connor, Laserina; Stokes, Diarmuid; Fealy, Gerard M; O'Brien, Denise; Smith, Rita; McNamara, Martin S; Egan, Claire

2017-03-01

A discussion of the potential use of rapid review approaches in nursing and midwifery research which presents a worked example from a study conducted to inform policy decision-making. Rapid reviews, which can be defined as outputs of a knowledge synthesis approach that involves modifying or omitting elements of a systematic review process due to limited time or resources, are becoming increasingly popular in health research. This paper provides guidance on how a rapid review can be undertaken and discusses the strengths and challenges of the approach. Data from a rapid review of the literature undertaken in 2015 is used as a worked example to highlight one method of undertaking a rapid review. Seeking evidence to inform health policy-making or evidence based practice is a process that can be limited by time constraints, making it difficult to conduct comprehensive systematic reviews. Rapid reviews provide a solution as they are a systematic method of synthesizing evidence quickly. There is no single best way to conduct a rapid review but researchers can ensure they are adhering to best practice by being systematic, having subject and methodological expertise on the review team, reporting the details of the approach they took, highlighting the limitations of the approach, engaging in good evidence synthesis and communicating regularly with end users, other team members and experts. © 2016 John Wiley & Sons Ltd.

NegGOA: negative GO annotations selection using ontology structure.

PubMed

Fu, Guangyuan; Wang, Jun; Yang, Bo; Yu, Guoxian

2016-10-01

Predicting the biological functions of proteins is one of the key challenges in the post-genomic era. Computational models have demonstrated the utility of applying machine learning methods to predict protein function. Most prediction methods explicitly require a set of negative examples-proteins that are known not carrying out a particular function. However, Gene Ontology (GO) almost always only provides the knowledge that proteins carry out a particular function, and functional annotations of proteins are incomplete. GO structurally organizes more than tens of thousands GO terms and a protein is annotated with several (or dozens) of these terms. For these reasons, the negative examples of a protein can greatly help distinguishing true positive examples of the protein from such a large candidate GO space. In this paper, we present a novel approach (called NegGOA) to select negative examples. Specifically, NegGOA takes advantage of the ontology structure, available annotations and potentiality of additional annotations of a protein to choose negative examples of the protein. We compare NegGOA with other negative examples selection algorithms and find that NegGOA produces much fewer false negatives than them. We incorporate the selected negative examples into an efficient function prediction model to predict the functions of proteins in Yeast, Human, Mouse and Fly. NegGOA also demonstrates improved accuracy than these comparing algorithms across various evaluation metrics. In addition, NegGOA is less suffered from incomplete annotations of proteins than these comparing methods. The Matlab and R codes are available at https://sites.google.com/site/guoxian85/neggoa gxyu@swu.edu.cn Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Training Self-Regulated Learning Skills with Video Modeling Examples: Do Task-Selection Skills Transfer?

ERIC Educational Resources Information Center

Raaijmakers, Steven F.; Baars, Martine; Schaap, Lydia; Paas, Fred; van Merriënboer, Jeroen; van Gog, Tamara

2018-01-01

Self-assessment and task-selection skills are crucial in self-regulated learning situations in which students can choose their own tasks. Prior research suggested that training with video modeling examples, in which another person (the model) demonstrates and explains the cyclical process of problem-solving task performance, self-assessment, and…

Inertia: the discrepancy between individual and common good in dispersal and prospecting behaviour.

PubMed

Delgado, María del Mar; Ratikainen, Irja I; Kokko, Hanna

2011-08-01

The group selection debate of the 1960s made it clear that evolution does not necessarily increase population performance. Individuals can be selected to have traits that diminish a common good and make population persistence difficult. At the extreme, the discrepancy between levels of selection is predicted to make traits evolve towards values at which a population can no longer persist (evolutionary suicide). Dispersal and prospecting are prime examples of traits that have a strong influence on population persistence under environmental and demographic stochasticity. Theory predicts that an 'optimal' dispersal strategy from a population point of view can differ considerably from that produced by individual-level selection. Because dispersal is frequently risky or otherwise costly, individuals are often predicted to disperse less than would be ideal for population performance (persistence or size). We define this discrepancy as 'inertia' and examine current knowledge of its occurrence and effects on population dynamics in nature. We argue that inertia is potentially widespread but that a framework is currently lacking for predicting precisely the extent to which it has a real influence on population persistence. The opposite of inertia, 'hypermobility' (more dispersal by individuals than would maximize population performance) remains a possibility: it is known that highest dispersal rates do not lead to best expected population performance, and examples of such high dispersal evolving exist at least in the theoretical literature. We also show, by considering prospecting behaviour, that similar issues arise in species with advanced cognitive and learning abilities. Individual prospecting strategies and the information acquired during dispersal are known to influence the decisions and therefore the fate of individuals and, as a corollary, populations. Again, the willingness of individuals to sample environments might evolve to levels that are not optimal for populations. This conflict can take intriguing forms. For example, better cognitive abilities of individuals may not always lead to better population-level performance. Simulation studies have found that 'blind' dispersal can lead to better connected metapopulations than cognitively more advanced habitat choice rules: the latter can lead to too many individuals sticking to nearby safe habitat. The study of the mismatch between individual and population fitness should not be a mere intellectual exercise. Population managers typically need to take a population-level view of performance, which may necessitate human intervention if it differs from what is selected for. We conclude that our knowledge of inertia and hypermobility would advance faster if theoretical studies--without much additional effort--quantified the population consequences of the evolving traits and compared this with hypothetical (not selectively favoured) dispersal rules, and if empirical studies were similarly conducted with the differing levels of selection in mind. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.

Scaffolding Meta-Cognitive Skills for Effective Analogical Problem Solving via Tailored Example Selection

ERIC Educational Resources Information Center

Muldner, Kasia; Conati, Cristina

2010-01-01

Although worked-out examples play a key role in cognitive skill acquisition, research demonstrates that students have various levels of meta-cognitive abilities for using examples effectively. The Example Analogy (EA)-Coach is an Intelligent Tutoring System that provides adaptive support to foster meta-cognitive behaviors relevant to a specific…

Examples in the Teaching of Mathematics: Teachers' Perceptions

ERIC Educational Resources Information Center

Ng, Lay Keow; Dindyal, Jaguthsing

2015-01-01

As part of a study examining how teachers in Singapore select and use examples for teaching mathematics, 121 teachers from 24 secondary schools responded to three open-ended questions about the use of examples in teaching. The results show that students' abilities and the difficulty level of the examples were among the topmost considerations…

A Guide to Writing a Qualitative Systematic Review Protocol to Enhance Evidence-Based Practice in Nursing and Health Care.

PubMed

Butler, Ashleigh; Hall, Helen; Copnell, Beverley

2016-06-01

The qualitative systematic review is a rapidly developing area of nursing research. In order to present trustworthy, high-quality recommendations, such reviews should be based on a review protocol to minimize bias and enhance transparency and reproducibility. Although there are a number of resources available to guide researchers in developing a quantitative review protocol, very few resources exist for qualitative reviews. To guide researchers through the process of developing a qualitative systematic review protocol, using an example review question. The key elements required in a systematic review protocol are discussed, with a focus on application to qualitative reviews: Development of a research question; formulation of key search terms and strategies; designing a multistage review process; critical appraisal of qualitative literature; development of data extraction techniques; and data synthesis. The paper highlights important considerations during the protocol development process, and uses a previously developed review question as a working example. This paper will assist novice researchers in developing a qualitative systematic review protocol. By providing a worked example of a protocol, the paper encourages the development of review protocols, enhancing the trustworthiness and value of the completed qualitative systematic review findings. Qualitative systematic reviews should be based on well planned, peer reviewed protocols to enhance the trustworthiness of results and thus their usefulness in clinical practice. Protocols should outline, in detail, the processes which will be used to undertake the review, including key search terms, inclusion and exclusion criteria, and the methods used for critical appraisal, data extraction and data analysis to facilitate transparency of the review process. Additionally, journals should encourage and support the publication of review protocols, and should require reference to a protocol prior to publication of the review results. © 2016 Sigma Theta Tau International.

Applications of Palladium-Catalyzed C-N Cross-Coupling Reactions.

PubMed

Ruiz-Castillo, Paula; Buchwald, Stephen L

2016-10-12

Pd-catalyzed cross-coupling reactions that form C-N bonds have become useful methods to synthesize anilines and aniline derivatives, an important class of compounds throughout chemical research. A key factor in the widespread adoption of these methods has been the continued development of reliable and versatile catalysts that function under operationally simple, user-friendly conditions. This review provides an overview of Pd-catalyzed N-arylation reactions found in both basic and applied chemical research from 2008 to the present. Selected examples of C-N cross-coupling reactions between nine classes of nitrogen-based coupling partners and (pseudo)aryl halides are described for the synthesis of heterocycles, medicinally relevant compounds, natural products, organic materials, and catalysts.

Carpool incentives: evaluation of operational experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-03-01

The report reviews both the published and unpublished literature with respect to various incentives that could increase carpooling and to determine, where possible, the effects of these incentives on carpooling. The coverage included theoretical and analytical work, as well as empirical observations of programs in operation both in this country and abroad. The primary focus is on the identification of actual examples of possible carpooling incentives, their description and implementation characteristics, applicability, institutional/legal barriers, public acceptability, and their effects on travel behavior and energy use. The relevant literature, applications, and existing data sources were canvassed and used to evaluate bothmore » the technical potential and the feasibility of implementation of the various policies selected for study.« less

Developing a UAS Program for Electric Utilities

NASA Astrophysics Data System (ADS)

Keltgen, James

New innovations and technologies using unmanned aerial systems (UAS), or drones, have created unique opportunities for commercial applications. Electric utilities, likewise, realize the benefits of using UAS as a tool in electric utility operations. Although the opportunities exist, establishing a UAS program for electric utilities is largely an endeavor of trial and error or research and development with no clear path defined on how to establish a UAS program. By reviewing UAS use case examples and integrating lessons learned with Federal Aviation Administration (FAA) regulations, UAS best practices, unique electric utility values, legal and insurance perspectives, equipment selection, and thoughtful planning and preparation; a solution model is developed to establish a UAS program for electric utilities.

Optimizing oncology therapeutics through quantitative translational and clinical pharmacology: challenges and opportunities.

PubMed

Venkatakrishnan, K; Friberg, L E; Ouellet, D; Mettetal, J T; Stein, A; Trocóniz, I F; Bruno, R; Mehrotra, N; Gobburu, J; Mould, D R

2015-01-01

Despite advances in biomedical research that have deepened our understanding of cancer hallmarks, resulting in the discovery and development of targeted therapies, the success rates of oncology drug development remain low. Opportunities remain for objective dose selection informed by exposure-response understanding to optimize the benefit-risk balance of novel therapies for cancer patients. This review article discusses the principles and applications of modeling and simulation approaches across the lifecycle of development of oncology therapeutics. Illustrative examples are used to convey the value gained from integration of quantitative clinical pharmacology strategies from the preclinical-translational phase through confirmatory clinical evaluation of efficacy and safety. © 2014 American Society for Clinical Pharmacology and Therapeutics.

The influence of the microenvironment on the malignant phenotype

NASA Technical Reports Server (NTRS)

Park, C. C.; Bissell, M. J.; Barcellos-Hoff, M. H.

2000-01-01

Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. As tissue becomes cancerous, there are reciprocal interactions between neoplastic cells, adjacent normal cells such as stroma and endothelium, and their microenvironments. The current dominant paradigm wherein multiple genetic lesions provide both the impetus for, and the Achilles heel of, cancer might be inadequate to understand cancer as a disease process. In the following brief review, we will use selected examples to illustrate the influence of the microenvironment in the evolution of the malignant phenotype. We will also discuss recent studies that suggest novel therapeutic interventions might be derived from focusing on microenvironment and tumor cells interactions.

Niche construction through phenological plasticity: life history dynamics and ecological consequences.

PubMed

Donohue, Kathleen

2005-04-01

The ability of an organism to alter the environment that it experiences has been termed 'niche construction'. Plants have several ways whereby they can determine the environment to which they are exposed at different life stages. This paper discusses three of these: plasticity in dispersal, flowering timing and germination timing. It reviews pathways through which niche construction alters evolutionary and ecological trajectories by altering the selective environment to which organisms are exposed, the phenotypic expression of plastic characters, and the expression of genetic variation. It provides examples whereby niche construction creates positive or negative feedbacks between phenotypes and environments, which in turn cause novel evolutionary constraints and novel life-history expression. Copyright New Phytologist (2005).

Studying real-world perceptual expertise

PubMed Central

Shen, Jianhong; Mack, Michael L.; Palmeri, Thomas J.

2014-01-01

Significant insights into visual cognition have come from studying real-world perceptual expertise. Many have previously reviewed empirical findings and theoretical developments from this work. Here we instead provide a brief perspective on approaches, considerations, and challenges to studying real-world perceptual expertise. We discuss factors like choosing to use real-world versus artificial object domains of expertise, selecting a target domain of real-world perceptual expertise, recruiting experts, evaluating their level of expertise, and experimentally testing experts in the lab and online. Throughout our perspective, we highlight expert birding (also called birdwatching) as an example, as it has been used as a target domain for over two decades in the perceptual expertise literature. PMID:25147533

Applications of Palladium-Catalyzed C–N Cross-Coupling Reactions

PubMed Central

2016-01-01

Pd-catalyzed cross-coupling reactions that form C–N bonds have become useful methods to synthesize anilines and aniline derivatives, an important class of compounds throughout chemical research. A key factor in the widespread adoption of these methods has been the continued development of reliable and versatile catalysts that function under operationally simple, user-friendly conditions. This review provides an overview of Pd-catalyzed N-arylation reactions found in both basic and applied chemical research from 2008 to the present. Selected examples of C–N cross-coupling reactions between nine classes of nitrogen-based coupling partners and (pseudo)aryl halides are described for the synthesis of heterocycles, medicinally relevant compounds, natural products, organic materials, and catalysts. PMID:27689804

Data Sharing: Convert Challenges into Opportunities.

PubMed

Figueiredo, Ana Sofia

2017-01-01

Initiatives for sharing research data are opportunities to increase the pace of knowledge discovery and scientific progress. The reuse of research data has the potential to avoid the duplication of data sets and to bring new views from multiple analysis of the same data set. For example, the study of genomic variations associated with cancer profits from the universal collection of such data and helps in selecting the most appropriate therapy for a specific patient. However, data sharing poses challenges to the scientific community. These challenges are of ethical, cultural, legal, financial, or technical nature. This article reviews the impact that data sharing has in science and society and presents guidelines to improve the efficient sharing of research data.

Pancreatic cancer biology and genetics from an evolutionary perspective

PubMed Central

Makohon-Moore, Alvin; Iacobuzio-Donahue, Christine A.

2017-01-01

Cancer is an evolutionary disease, containing the hallmarks of an asexually reproducing unicellular organism subject to evolutionary paradigms. Pancreatic ductal adenocarcinoma (hereafter referred to as pancreatic cancer) is a particularly robust example of this phenomenon. Genomic features indicate that pancreatic cancer cells are selected for fitness advantages when encountering the geographic and resource-depleted constraints of the microenvironment. Phenotypic adaptations to these pressures help disseminated cells to survive in secondary sites, a major clinical problem for patients with this disease. In this Review we gather the wide-ranging aspects of pancreatic cancer research into a single concept rooted in Darwinian evolution, with the goal of identifying novel insights and opportunities for study. PMID:27444064

Data Sharing: Convert Challenges into Opportunities

PubMed Central

Figueiredo, Ana Sofia

2017-01-01

Initiatives for sharing research data are opportunities to increase the pace of knowledge discovery and scientific progress. The reuse of research data has the potential to avoid the duplication of data sets and to bring new views from multiple analysis of the same data set. For example, the study of genomic variations associated with cancer profits from the universal collection of such data and helps in selecting the most appropriate therapy for a specific patient. However, data sharing poses challenges to the scientific community. These challenges are of ethical, cultural, legal, financial, or technical nature. This article reviews the impact that data sharing has in science and society and presents guidelines to improve the efficient sharing of research data. PMID:29270401

Evaluation of the effectiveness of color attributes for video indexing

NASA Astrophysics Data System (ADS)

Chupeau, Bertrand; Forest, Ronan

2001-10-01

Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, 12 combinations of color space and quantization were selected, together with 12 histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-by-example scenario. For that purpose, a set of still-picture databases was built by extracting key frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

Evaluation of the effectiveness of color attributes for video indexing

NASA Astrophysics Data System (ADS)

Chupeau, Bertrand; Forest, Ronan

2001-01-01

Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, twelve combinations of color space and quantization were selected, together with twelve histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-be-example scenario. For that purpose, a set of still-picture databases was built by extracting key-frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

Evaluation of the effectiveness of color attributes for video indexing

NASA Astrophysics Data System (ADS)

Chupeau, Bertrand; Forest, Ronan

2000-12-01

Color features are reviewed and their effectiveness assessed in the application framework of key-frame clustering for abstracting unconstrained video. Existing color spaces and associated quantization schemes are first studied. Description of global color distribution by means of histograms is then detailed. In our work, twelve combinations of color space and quantization were selected, together with twelve histogram metrics. Their respective effectiveness with respect to picture similarity measurement was evaluated through a query-be-example scenario. For that purpose, a set of still-picture databases was built by extracting key-frames from several video clips, including news, documentaries, sports and cartoons. Classical retrieval performance evaluation criteria were adapted to the specificity of our testing methodology.

Chaotic coordinates for the Large Helical Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudson, S. R., E-mail: shudson@pppl.gov; Suzuki, Y.

The theory of quadratic-flux-minimizing (QFM) surfaces is reviewed, and numerical techniques that allow high-order QFM surfaces to be efficiently constructed for experimentally relevant, non-integrable magnetic fields are described. As a practical example, the chaotic edge of the magnetic field in the Large Helical Device (LHD) is examined. A precise technique for finding the boundary surface is implemented, the hierarchy of partial barriers associated with the near-critical cantori is constructed, and a coordinate system, which we call chaotic coordinates, that is based on a selection of QFM surfaces is constructed that simplifies the description of the magnetic field, so that fluxmore » surfaces become “straight” and islands become “square.”.« less

Analyzing lease/purchase options.

PubMed

Ciolek, D; Mace, J D

1998-01-01

The authors' previous article, "Equipment Acquisition Using Various Forms of Leasing," covers information necessary for selecting among the different kinds of leases. This article explains how to reach a proper financial analysis, preferably using two phases. Using a representative example, the article guides the reader through the first phase and introduces the elements needing review in the second phase. Key elements include pretax aftertax and cash flow analyses. Different organizations use different yardsticks to measure the financials of a transaction, but in general, cash is king. Therefore, the most widely used comparison is the purchase versus lease IRR (internal rate of return) produced by measuring the cash flow of the purchase case compared to the cash flow of the lease case.

Applications of Pharmacometrics in the Clinical Development and Pharmacotherapy of Anti-Infectives

PubMed Central

Trivedi, Ashit; Lee, Richard E; Meibohm, Bernd

2013-01-01

With the increased emergence of anti-infective resistance in recent years, much focus has recently been drawn to the development of new anti-infectives and the optimization of treatment regimens and combination therapies for established antimicrobials. In this context, the field of pharmacometrics using quantitative numerical modeling and simulation techniques has in recent years emerged as an invaluable tool in the pharmaceutical industry, academia and regulatory agencies to facilitate the integration of preclinical and clinical development data and to provide a scientifically based framework for rationale dosage regimen design and treatment optimization. This review highlights the usefulness of pharmacometric analyses in anti-infective drug development and applied pharmacotherapy with select examples. PMID:23473593

Arranging computer architectures to create higher-performance controllers

NASA Technical Reports Server (NTRS)

Jacklin, Stephen A.

1988-01-01

Techniques for integrating microprocessors, array processors, and other intelligent devices in control systems are reviewed, with an emphasis on the (re)arrangement of components to form distributed or parallel processing systems. Consideration is given to the selection of the host microprocessor, increasing the power and/or memory capacity of the host, multitasking software for the host, array processors to reduce computation time, the allocation of real-time and non-real-time events to different computer subsystems, intelligent devices to share the computational burden for real-time events, and intelligent interfaces to increase communication speeds. The case of a helicopter vibration-suppression and stabilization controller is analyzed as an example, and significant improvements in computation and throughput rates are demonstrated.

Advances in Mid-Infrared Spectroscopy for Chemical Analysis

NASA Astrophysics Data System (ADS)

Haas, Julian; Mizaikoff, Boris

2016-06-01

Infrared spectroscopy in the 3-20 μm spectral window has evolved from a routine laboratory technique into a state-of-the-art spectroscopy and sensing tool by benefitting from recent progress in increasingly sophisticated spectra acquisition techniques and advanced materials for generating, guiding, and detecting mid-infrared (MIR) radiation. Today, MIR spectroscopy provides molecular information with trace to ultratrace sensitivity, fast data acquisition rates, and high spectral resolution catering to demanding applications in bioanalytics, for example, and to improved routine analysis. In addition to advances in miniaturized device technology without sacrificing analytical performance, selected innovative applications for MIR spectroscopy ranging from process analysis to biotechnology and medical diagnostics are highlighted in this review.

Applications of aerospace technology in industry, a technology transfer profile: Fire safety

NASA Technical Reports Server (NTRS)

Kottenstette, J. P.; Freeman, J. E.; Heins, C. R.; Hildred, W. M.; Johnson, F. D.; Staskin, E. R.

1971-01-01

The fire safety field is considered as being composed of three parts: an industry, a technology base, and a user base. An overview of the field is presented, including a perspective on the magnitude of the national fire safety problem. Selected NASA contributions to the technology of fire safety are considered. Communication mechanisms, particularly conferences and publications, used by NASA to alert the community to new developments in the fire safety field, are reviewed. Several examples of nonaerospace applications of NASA-generated fire safety technology are also presented. Issues associated with attempts to transfer this technology from the space program to other sectors of the American economy are outlined.

[Quality assurance in occupational health services].

PubMed

Michalak, J

1996-01-01

The general conditions influencing the quality assurance and audit in Polish occupational health services are presented. The factors promoting or hampering the implementation of quality assurance and audits are also discussed. The major influence on the transformation of Polish occupational health services in exorted by employers who are committed to cover the costs of the obligatory prophylactic examination of their employees. This is the factor which also contributes to the improvement of quality if services. The definitions of the most important terms are reviewed to highlight their accordance with the needs of occupational health services in Poland. The examples of audit are presented and the elements of selected methods of auditing are suggested to be adopted in Poland.

Boronic acid-based chemical sensors for saccharides.

PubMed

Zhang, Xiao-Tai; Liu, Guang-Jian; Ning, Zhang-Wei; Xing, Guo-Wen

2017-11-27

During the past decades, the interaction between boronic acids-functionalized sensors and saccharides is of great interest in the frontier domain of the interdiscipline concerning both biology and chemistry. Various boronic acid-based sensing systems have been developed to detect saccharides and corresponding derivatives in vitro as well as in vivo, which embrace unimolecular sensors, two-component sensing ensembles, functional assemblies, and boronic acid-loaded nanomaterials or surfaces. New sensing strategies emerge in endlessly with excellent selectivity and sensitivity. In this review, several typical sensing systems were introduced and some promising examples were highlighted to enable the deep insight of saccharides sensing on the basis of boronic acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Peptide neuromodulation in invertebrate model systems

PubMed Central

Taghert, Paul H.; Nitabach, Michael N.

2012-01-01

Neuropeptides modulate neural circuits controlling adaptive animal behaviors and physiological processes, such as feeding/metabolism, reproductive behaviors, circadian rhythms, central pattern generation, and sensorimotor integration. Invertebrate model systems have enabled detailed experimental analysis using combined genetic, behavioral, and physiological approaches. Here we review selected examples of neuropeptide modulation in crustaceans, mollusks, insects, and nematodes, with a particular emphasis on the genetic model organisms Drosophila melanogaster and Caenorhabditis elegans, where remarkable progress has been made. On the basis of this survey, we provide several integrating conceptual principles for understanding how neuropeptides modulate circuit function, and also propose that continued progress in this area requires increased emphasis on the development of richer, more sophisticated behavioral paradigms. PMID:23040808

Design Principles of Worked Examples: A Review of the Empirical Studies

ERIC Educational Resources Information Center

Shen, Chun-Yi; Tsai, Hui-Chun

2009-01-01

Many researchers investigated the efficacy of using worked examples in classroom instruction and provided evidence in the effectiveness of worked example instruction in mathematics, computer programming, physics, and etc. However, there are limited studies in worked example design. The purpose of this study is to generate the instructional design…

Primer in Genetics and Genomics, Article 2-Advancing Nursing Research With Genomic Approaches.

PubMed

Lee, Hyunhwa; Gill, Jessica; Barr, Taura; Yun, Sijung; Kim, Hyungsuk

2017-03-01

Nurses investigate reasons for variable patient symptoms and responses to treatments to inform how best to improve outcomes. Genomics has the potential to guide nursing research exploring contributions to individual variability. This article is meant to serve as an introduction to the novel methods available through genomics for addressing this critical issue and includes a review of methodological considerations for selected genomic approaches. This review presents essential concepts in genetics and genomics that will allow readers to identify upcoming trends in genomics nursing research and improve research practice. It introduces general principles of genomic research and provides an overview of the research process. It also highlights selected nursing studies that serve as clinical examples of the use of genomic technologies. Finally, the authors provide suggestions about how to apply genomic technology in nursing research along with directions for future research. Using genomic approaches in nursing research can advance the understanding of the complex pathophysiology of disease susceptibility and different patient responses to interventions. Nurses should be incorporating genomics into education, clinical practice, and research as the influence of genomics in health-care research and practice continues to grow. Nurses are also well placed to translate genomic discoveries into improved methods for patient assessment and intervention.

Development of Ion Chemosensors Based on Porphyrin Analogues.

PubMed

Ding, Yubin; Zhu, Wei-Hong; Xie, Yongshu

2017-02-22

Sensing of metal ions and anions is of great importance because of their widespread distribution in environmental systems and biological processes. Colorimetric and fluorescent chemosensors based on organic molecular species have been demonstrated to be effective for the detection of various ions and possess the significant advantages of low cost, high sensitivity, and convenient implementation. Of the available classes of organic molecules, porphyrin analogues possess inherently many advantageous features, making them suitable for the design of ion chemosensors, with the targeted sensing behavior achieved and easily modulated based on their following characteristics: (1) NH moieties properly disposed for binding of anions through cooperative hydrogen-bonding interactions; (2) multiple pyrrolic N atoms or other heteroatoms for selectively chelating metal ions; (3) variability of macrocycle size and peripheral substitution for modulation of ion selectivity and sensitivity; and (4) tunable near-infrared emission and good biocompatibility. In this Review, design strategies, sensing mechanisms, and sensing performance of ion chemosensors based on porphyrin analogues are described by use of extensive examples. Ion chemosensors based on normal porphyrins and linear oligopyrroles are also briefly described. This Review provides valuable information for researchers of related areas and thus may inspire the development of more practical and effective approaches for designing high-performance ion chemosensors based on porphyrin analogues and other relevant compounds.

Holocaust and strategic bombing: case studies in the psychology, organization, and technology of mass killing in the twentieth century

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markusen, E.R.

After preliminary discussion of the unprecedented scale of mass killing in the twentieth century, the threat of nuclear war, and the widespread neglect of these issues, the literature on two major types of government sanctioned mass killing is reviewed; genocide, in which a government slaughters its own citizens or subjects, and total war, in which two or more governments slaughter each other's civilian citizens or subjects. This literature review reaches two basic conclusions: (1) there is considerable inconsistency and ambiguity among definitions of genocide and total war; and (2) there is a controversy regarding how distinct or similar the twomore » forms of mass killing actually are. A comparative historical analysis was undertaken in which the Nazi Holocaust was selected as an example of genocide, and the Allied strategic bombing campaigns during World War II were selected to exemplify total war. The two cases are compared in terms of a conceptual framework of five hypothesized facilitating factors. On the basis of this comparative analysis, four or the five hypothesized facilitating factors are found to have played important roles in both cases. The findings of the study are discussed, and their implications for the threat of nuclear holocaust are explored.« less

Influence of macrosocial policies on women's health and gender inequalities in health.

PubMed

Borrell, Carme; Palència, Laia; Muntaner, Carles; Urquía, Marcelo; Malmusi, Davide; O'Campo, Patricia

2014-01-01

Gender inequalities in health have been widely described, but few studies have examined the upstream sources of these inequalities in health. The objectives of this review are 1) to identify empirical papers that assessed the effect of gender equality policies on gender inequalities in health or on women's health by using between-country (or administrative units within a country) comparisons and 2) to provide an example of published evidence on the effects of a specific policy (parental leave) on women's health. We conducted a literature search covering the period from 1970 to 2012, using several bibliographical databases. We assessed 1,238 abstracts and selected 19 papers that considered gender equality policies, compared several countries or different states in 1 country, and analyzed at least 1 health outcome among women or compared between genders. To illustrate specific policy effects, we also selected articles that assessed associations between parental leave and women's health. Our review partially supports the hypothesis that Nordic social democratic welfare regimes and dual-earner family models best promote women's health. Meanwhile, enforcement of reproductive policies, mainly studied across US states, is associated with better mental health outcomes, although less with other outcomes. Longer paid maternity leave was also generally associated with better mental health and longer duration of breastfeeding.

PUMAS (Practical Uses of Math And Science) - Low Cost, High Impact

NASA Astrophysics Data System (ADS)

Kahn, R. A.

2004-12-01

PUMAS is an on-line journal, aimed at giving pre-college teachers brief examples showing how math and science topics taught in K-12 classes can be used in interesting settings, including everyday life. The concept is a simple one - (1) ask scientists, engineers, and other content experts to write up their favorite examples of practical uses, (2) ask the authors to key their examples to the National Standards and Benchmarks, so the material is grade-appropriate and useful in the classroom, (3) have each example peer-reviewed by at least one scientist with a relevant background, and at least one teacher at an appropriate grade level, helping keep an emphasis on quality, and (4) disseminate the examples widely and inexpensively through the PUMAS Web Site (http://pumas.jpl.nasa.gov). PUMAS examples may be activities, anecdotes, descriptions of "neat ideas," formal exercises, puzzles, or demonstrations; each one is a gem, written in the voice of its author. The PUMAS site also provides opportunities for feedback on individual examples and on the journal as a whole. As with most scientific journals, the writing, reviewing, and editing efforts are volunteered; they leverage the "community service" offered by so many teachers and scientists. We have streamlined all aspects of the example submission, review, and search processes so participants can contribute at a high level, with a minimum of extraneous effort. The primary PUMAS operating expenses cover Web Site technical maintenance and computer security. The PUMAS site receives several thousand unique queries per week, and publishes an average of about one new example per month. Maintaining a strong user base has been helped by endorsements from such organizations as the NSTA and NCTM. To contributors we offer an avenue for making a real impact on pre-college education with a relatively small time commitment, and the opportunity for peer-reviewed publication. We are always looking for good examples of the Practical Uses of Math And Science. This work is performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Genomic prediction in animals and plants: simulation of data, validation, reporting, and benchmarking.

PubMed

Daetwyler, Hans D; Calus, Mario P L; Pong-Wong, Ricardo; de Los Campos, Gustavo; Hickey, John M

2013-02-01

The genomic prediction of phenotypes and breeding values in animals and plants has developed rapidly into its own research field. Results of genomic prediction studies are often difficult to compare because data simulation varies, real or simulated data are not fully described, and not all relevant results are reported. In addition, some new methods have been compared only in limited genetic architectures, leading to potentially misleading conclusions. In this article we review simulation procedures, discuss validation and reporting of results, and apply benchmark procedures for a variety of genomic prediction methods in simulated and real example data. Plant and animal breeding programs are being transformed by the use of genomic data, which are becoming widely available and cost-effective to predict genetic merit. A large number of genomic prediction studies have been published using both simulated and real data. The relative novelty of this area of research has made the development of scientific conventions difficult with regard to description of the real data, simulation of genomes, validation and reporting of results, and forward in time methods. In this review article we discuss the generation of simulated genotype and phenotype data, using approaches such as the coalescent and forward in time simulation. We outline ways to validate simulated data and genomic prediction results, including cross-validation. The accuracy and bias of genomic prediction are highlighted as performance indicators that should be reported. We suggest that a measure of relatedness between the reference and validation individuals be reported, as its impact on the accuracy of genomic prediction is substantial. A large number of methods were compared in example simulated and real (pine and wheat) data sets, all of which are publicly available. In our limited simulations, most methods performed similarly in traits with a large number of quantitative trait loci (QTL), whereas in traits with fewer QTL variable selection did have some advantages. In the real data sets examined here all methods had very similar accuracies. We conclude that no single method can serve as a benchmark for genomic prediction. We recommend comparing accuracy and bias of new methods to results from genomic best linear prediction and a variable selection approach (e.g., BayesB), because, together, these methods are appropriate for a range of genetic architectures. An accompanying article in this issue provides a comprehensive review of genomic prediction methods and discusses a selection of topics related to application of genomic prediction in plants and animals.

Genomic Prediction in Animals and Plants: Simulation of Data, Validation, Reporting, and Benchmarking

PubMed Central

Daetwyler, Hans D.; Calus, Mario P. L.; Pong-Wong, Ricardo; de los Campos, Gustavo; Hickey, John M.

2013-01-01

The genomic prediction of phenotypes and breeding values in animals and plants has developed rapidly into its own research field. Results of genomic prediction studies are often difficult to compare because data simulation varies, real or simulated data are not fully described, and not all relevant results are reported. In addition, some new methods have been compared only in limited genetic architectures, leading to potentially misleading conclusions. In this article we review simulation procedures, discuss validation and reporting of results, and apply benchmark procedures for a variety of genomic prediction methods in simulated and real example data. Plant and animal breeding programs are being transformed by the use of genomic data, which are becoming widely available and cost-effective to predict genetic merit. A large number of genomic prediction studies have been published using both simulated and real data. The relative novelty of this area of research has made the development of scientific conventions difficult with regard to description of the real data, simulation of genomes, validation and reporting of results, and forward in time methods. In this review article we discuss the generation of simulated genotype and phenotype data, using approaches such as the coalescent and forward in time simulation. We outline ways to validate simulated data and genomic prediction results, including cross-validation. The accuracy and bias of genomic prediction are highlighted as performance indicators that should be reported. We suggest that a measure of relatedness between the reference and validation individuals be reported, as its impact on the accuracy of genomic prediction is substantial. A large number of methods were compared in example simulated and real (pine and wheat) data sets, all of which are publicly available. In our limited simulations, most methods performed similarly in traits with a large number of quantitative trait loci (QTL), whereas in traits with fewer QTL variable selection did have some advantages. In the real data sets examined here all methods had very similar accuracies. We conclude that no single method can serve as a benchmark for genomic prediction. We recommend comparing accuracy and bias of new methods to results from genomic best linear prediction and a variable selection approach (e.g., BayesB), because, together, these methods are appropriate for a range of genetic architectures. An accompanying article in this issue provides a comprehensive review of genomic prediction methods and discusses a selection of topics related to application of genomic prediction in plants and animals. PMID:23222650

Systematic reviews, overviews of reviews and comparative effectiveness reviews: a discussion of approaches to knowledge synthesis.

PubMed

Hartling, Lisa; Vandermeer, Ben; Fernandes, Ricardo M

2014-06-01

The Cochrane Collaboration has been at the forefront of developing methods for knowledge synthesis internationally. We discuss three approaches to synthesize evidence for healthcare interventions: systematic reviews (SRs), overviews of reviews and comparative effectiveness reviews. We illustrate these approaches with examples from knowledge syntheses on interventions for bronchiolitis, a common acute paediatric condition. Some of the differences among these approaches are subtle and methods are not necessarily mutually exclusive to a single review type. Systematic reviews bring together evidence from multiple studies in a rigorous fashion for a single intervention or group of interventions. Systematic reviews, as they have developed within healthcare, often focus on single or select interventions and direct pairwise comparisons; therefore, end-users may need to read several individual SRs to inform decision making. Overviews of reviews compile information from multiple SRs relevant to a single health problem. Overviews provide the end-user with a quick overview of the available evidence; however, overviews are dependent on the methods and decisions employed at the SR level. Furthermore, overviews do not often integrate evidence from different SRs quantitatively. Comparative effectiveness reviews, as we define them here, synthesize relevant evidence from individual studies to describe the relative benefits (or harms) of a range of interventions. Comparative effectiveness reviews may use statistical methods (network meta-analysis) to incorporate direct and indirect evidence; therefore, they can provide stronger inferences about the relative effectiveness (or safety) of interventions. While potentially more expensive and time-consuming to produce, a comparative effectiveness review provides a synthesis of a range of interventions for a given condition and the relative efficacy across interventions using consistent and standardized methodology. Copyright © 2014 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

How individual participant data meta-analyses have influenced trial design, conduct, and analysis.

PubMed

Tierney, Jayne F; Pignon, Jean-Pierre; Gueffyier, Francois; Clarke, Mike; Askie, Lisa; Vale, Claire L; Burdett, Sarah

2015-11-01

To demonstrate how individual participant data (IPD) meta-analyses have impacted directly on the design and conduct of trials and highlight other advantages IPD might offer. Potential examples of the impact of IPD meta-analyses on trials were identified at an international workshop, attended by individuals with experience in the conduct of IPD meta-analyses and knowledge of trials in their respective clinical areas. Experts in the field who did not attend were asked to provide any further examples. We then examined relevant trial protocols, publications, and Web sites to verify the impacts of the IPD meta-analyses. A subgroup of workshop attendees sought further examples and identified other aspects of trial design and conduct that may inform IPD meta-analyses. We identified 52 examples of IPD meta-analyses thought to have had a direct impact on the design or conduct of trials. After screening relevant trial protocols and publications, we identified 28 instances where IPD meta-analyses had clearly impacted on trials. They have influenced the selection of comparators and participants, sample size calculations, analysis and interpretation of subsequent trials, and the conduct and analysis of ongoing trials, sometimes in ways that would not possible with systematic reviews of aggregate data. We identified additional potential ways that IPD meta-analyses could be used to influence trials. IPD meta-analysis could be better used to inform the design, conduct, analysis, and interpretation of trials. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

How individual participant data meta-analyses have influenced trial design, conduct, and analysis

PubMed Central

Tierney, Jayne F.; Pignon, Jean-Pierre; Gueffyier, Francois; Clarke, Mike; Askie, Lisa; Vale, Claire L.; Burdett, Sarah; Alderson, P.; Askie, L.; Bennett, D.; Burdett, S.; Clarke, M.; Dias, S.; Emberson, J.; Gueyffier, F.; Iorio, A.; Macleod, M.; Mol, B.W.; Moons, C.; Parmar, M.; Perera, R.; Phillips, R.; Pignon, J.P.; Rees, J.; Reitsma, H.; Riley, R.; Rovers, M.; Rydzewska, L.; Schmid, C.; Shepperd, S.; Stenning, S.; Stewart, L.; Tierney, J.; Tudur Smith, C.; Vale, C.; Welge, J.; White, I.; Whiteley, W.

2015-01-01

Objectives To demonstrate how individual participant data (IPD) meta-analyses have impacted directly on the design and conduct of trials and highlight other advantages IPD might offer. Study Design and Setting Potential examples of the impact of IPD meta-analyses on trials were identified at an international workshop, attended by individuals with experience in the conduct of IPD meta-analyses and knowledge of trials in their respective clinical areas. Experts in the field who did not attend were asked to provide any further examples. We then examined relevant trial protocols, publications, and Web sites to verify the impacts of the IPD meta-analyses. A subgroup of workshop attendees sought further examples and identified other aspects of trial design and conduct that may inform IPD meta-analyses. Results We identified 52 examples of IPD meta-analyses thought to have had a direct impact on the design or conduct of trials. After screening relevant trial protocols and publications, we identified 28 instances where IPD meta-analyses had clearly impacted on trials. They have influenced the selection of comparators and participants, sample size calculations, analysis and interpretation of subsequent trials, and the conduct and analysis of ongoing trials, sometimes in ways that would not possible with systematic reviews of aggregate data. We identified additional potential ways that IPD meta-analyses could be used to influence trials. Conclusions IPD meta-analysis could be better used to inform the design, conduct, analysis, and interpretation of trials. PMID:26186982

48 CFR 1.603-2 - Selection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ACQUISITION REGULATIONS SYSTEM Career Development, Contracting Authority, and Responsibilities 1.603-2 Selection. In selecting contracting officers, the appointing official shall consider the complexity and..., business acumen, judgment, character, and reputation. Examples of selection criteria include— (a...

Land management: data availability and process understanding for global change studies.

PubMed

Erb, Karl-Heinz; Luyssaert, Sebastiaan; Meyfroidt, Patrick; Pongratz, Julia; Don, Axel; Kloster, Silvia; Kuemmerle, Tobias; Fetzel, Tamara; Fuchs, Richard; Herold, Martin; Haberl, Helmut; Jones, Chris D; Marín-Spiotta, Erika; McCallum, Ian; Robertson, Eddy; Seufert, Verena; Fritz, Steffen; Valade, Aude; Wiltshire, Andrew; Dolman, Albertus J

2017-02-01

In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land-cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one-tenth of the ice-free land surface is under intense human management, half under medium and one-fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling. © 2016 John Wiley & Sons Ltd.

Patient reported outcomes (PROs) in clinical trials: is 'in-trial' guidance lacking? a systematic review.

PubMed

Kyte, Derek G; Draper, Heather; Ives, Jonathan; Liles, Clive; Gheorghe, Adrian; Calvert, Melanie

2013-01-01

Patient reported outcomes (PROs) are increasingly assessed in clinical trials, and guidelines are available to inform the design and reporting of such trials. However, researchers involved in PRO data collection report that specific guidance on 'in-trial' activity (recruitment, data collection and data inputting) and the management of 'concerning' PRO data (i.e., data which raises concern for the well-being of the trial participant) appears to be lacking. The purpose of this review was to determine the extent and nature of published guidelines addressing these areas. Systematic review of 1,362 articles identified 18 eligible papers containing 'in-trial' guidelines. Two independent authors undertook a qualitative content analysis of the selected papers. Guidelines presented in each of the articles were coded according to an a priori defined coding frame, which demonstrated reliability (pooled Kappa 0.86-0.97), and validity (<2% residual category coding). The majority of guidelines present were concerned with 'pre-trial' activities (72%), for example, outcome measure selection and study design issues, or 'post-trial' activities (16%) such as data analysis, reporting and interpretation. 'In-trial' guidelines represented 9.2% of all guidance across the papers reviewed, with content primarily focused on compliance, quality control, proxy assessment and reporting of data collection. There were no guidelines surrounding the management of concerning PRO data. The findings highlight there are minimal in-trial guidelines in publication regarding PRO data collection and management in clinical trials. No guidance appears to exist for researchers involved with the handling of concerning PRO data. Guidelines are needed, which support researchers to manage all PRO data appropriately and which facilitate unbiased data collection.

Patient Reported Outcomes (PROs) in Clinical Trials: Is ‘In-Trial’ Guidance Lacking? A Systematic Review

PubMed Central

Kyte, Derek G.; Draper, Heather; Ives, Jonathan; Liles, Clive; Gheorghe, Adrian; Calvert, Melanie

2013-01-01

Background Patient reported outcomes (PROs) are increasingly assessed in clinical trials, and guidelines are available to inform the design and reporting of such trials. However, researchers involved in PRO data collection report that specific guidance on ‘in-trial’ activity (recruitment, data collection and data inputting) and the management of ‘concerning’ PRO data (i.e., data which raises concern for the well-being of the trial participant) appears to be lacking. The purpose of this review was to determine the extent and nature of published guidelines addressing these areas. Methods and Findings Systematic review of 1,362 articles identified 18 eligible papers containing ‘in-trial’ guidelines. Two independent authors undertook a qualitative content analysis of the selected papers. Guidelines presented in each of the articles were coded according to an a priori defined coding frame, which demonstrated reliability (pooled Kappa 0.86–0.97), and validity (<2% residual category coding). The majority of guidelines present were concerned with ‘pre-trial’ activities (72%), for example, outcome measure selection and study design issues, or ‘post-trial’ activities (16%) such as data analysis, reporting and interpretation. ‘In-trial’ guidelines represented 9.2% of all guidance across the papers reviewed, with content primarily focused on compliance, quality control, proxy assessment and reporting of data collection. There were no guidelines surrounding the management of concerning PRO data. Conclusions The findings highlight there are minimal in-trial guidelines in publication regarding PRO data collection and management in clinical trials. No guidance appears to exist for researchers involved with the handling of concerning PRO data. Guidelines are needed, which support researchers to manage all PRO data appropriately and which facilitate unbiased data collection. PMID:23560103

Protocol for a systematic review and economic evaluation of the clinical and cost-effectiveness of non-hospital-based non-invasive ventilation (NIV) in patients with stable end-stage COPD with hypercapnic respiratory failure.

PubMed

Dave, Chirag; Turner, Alice; Dretzke, Janine; Bayliss, Sue; O'Brien, Deirdre; Jowett, Sue; Moore, David

2014-03-27

Chronic obstructive pulmonary disease (COPD) remains a significant public health burden. Non-invasive ventilation (NIV) is a method of supported breathing used as standard care for acutely unwell patients in hospital with COPD, but there is uncertainty around the potential benefits of using NIV in the treatment of stable patients in a non-hospital setting. This is a protocol for systematic reviews of the clinical and cost-effectiveness of NIV in this context, being undertaken in support of a model based economic evaluation. Standard systematic review methods aimed at minimising bias will be employed for study identification, selection and data extraction for both the clinical and economic systematic reviews. Bibliographic databases (for example MEDLINE, EMBASE) and ongoing trials registers will be searched from 1980 onwards. The search strategy will combine terms for the population with those for the intervention. Studies will be selected for review if the population includes adult patients with COPD and hypercapnic respiratory failure, however defined. Systematic reviews, randomised controlled trials and observational studies (with n >1) will be included, and quality assessment will be tailored to the different study designs. The primary outcome measures of interest are survival, quality of life, and healthcare utilisations (hospitalisation and Accident and Emergency attendances). Meta-analyses will be undertaken where clinical and methodological homogeneity exists, supported by predefined subgroup analyses where appropriate. A systematic review of the evidence on the cost-effectiveness of non-hospital NIV will be completed, and a model-based cost-utility analysis undertaken to determine the cost-effectiveness of non-hospital-based NIV compared with standard care. These reviews will attempt to clarify the clinical effectiveness of non-hospital NIV in COPD patients as well as the cost-effectiveness. The findings may indicate whether NIV in a non-hospital setting should be considered more routinely in this patient group, and what the likely cost implications will be. 2012:CRD42012003286.

The Pedagogical Examples of Groups and Rings That Algebraists Think Are Most Important in an Introductory Course

ERIC Educational Resources Information Center

Cook, John Paul; Fukawa-Connelly, Tim

2015-01-01

This article reports on an exploratory study designed to investigate the reasoning behind algebraists' selection of examples. Variation theory provided a lens to analyze their collections of examples. Our findings include the classes of examples of groups and rings that algebraists believe to be most pedagogically useful. Chief among their…

Using Process Data to Understand Outcomes in Sexual Health Promotion: An Example from a Review of School-Based Programmes to Prevent Sexually Transmitted Infections

ERIC Educational Resources Information Center

Shepherd, J.; Harden, A.; Barnett-Page, E.; Kavanagh, J.; Picot, J.; Frampton, G. K.; Cooper, K.; Hartwell, D.; Clegg, A.

2014-01-01

This article discusses how process indicators can complement outcomes as part of a comprehensive explanatory evaluation framework, using the example of skills-based behavioural interventions to prevent sexually transmitted infections and promote sexual health among young people in schools. A systematic review was conducted, yielding 12 eligible…

28 CFR 34.108 - Selection of reviewers.

Code of Federal Regulations, 2010 CFR

2010-07-01

....108 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.108 Selection of reviewers. The Program Manager, through the Director of the OJJDP program... by the Administrator. The selection process for peer reviewers is detailed in the OJJDP “Peer Review...

Predicting novel microRNA: a comprehensive comparison of machine learning approaches.

PubMed

Stegmayer, Georgina; Di Persia, Leandro E; Rubiolo, Mariano; Gerard, Matias; Pividori, Milton; Yones, Cristian; Bugnon, Leandro A; Rodriguez, Tadeo; Raad, Jonathan; Milone, Diego H

2018-05-23

The importance of microRNAs (miRNAs) is widely recognized in the community nowadays because these short segments of RNA can play several roles in almost all biological processes. The computational prediction of novel miRNAs involves training a classifier for identifying sequences having the highest chance of being precursors of miRNAs (pre-miRNAs). The big issue with this task is that well-known pre-miRNAs are usually few in comparison with the hundreds of thousands of candidate sequences in a genome, which results in high class imbalance. This imbalance has a strong influence on most standard classifiers, and if not properly addressed in the model and the experiments, not only performance reported can be completely unrealistic but also the classifier will not be able to work properly for pre-miRNA prediction. Besides, another important issue is that for most of the machine learning (ML) approaches already used (supervised methods), it is necessary to have both positive and negative examples. The selection of positive examples is straightforward (well-known pre-miRNAs). However, it is difficult to build a representative set of negative examples because they should be sequences with hairpin structure that do not contain a pre-miRNA. This review provides a comprehensive study and comparative assessment of methods from these two ML approaches for dealing with the prediction of novel pre-miRNAs: supervised and unsupervised training. We present and analyze the ML proposals that have appeared during the past 10 years in literature. They have been compared in several prediction tasks involving two model genomes and increasing imbalance levels. This work provides a review of existing ML approaches for pre-miRNA prediction and fair comparisons of the classifiers with same features and data sets, instead of just a revision of published software tools. The results and the discussion can help the community to select the most adequate bioinformatics approach according to the prediction task at hand. The comparative results obtained suggest that from low to mid-imbalance levels between classes, supervised methods can be the best. However, at very high imbalance levels, closer to real case scenarios, models including unsupervised and deep learning can provide better performance.

"Crowdsourcing" ten years in: A review.

PubMed

Wazny, Kerri

2017-12-01

First coined by Howe in 2006, the field of crowdsourcing has grown exponentially. Despite its growth and its transcendence across many fields, the definition of crowdsourcing has still not been agreed upon, and examples are poorly indexed in peer-reviewed literature. Many examples of crowdsourcing have not been scaled-up past the pilot phase. In spite of this, crowdsourcing has great potential, especially in global health where resources are lacking. This narrative review seeks to review both indexed and grey crowdsourcing literature broadly in order to explore the current state of the field. This is a review of reviews of crowdsourcing. Semantic searches were conducted using Google Scholar rather than indexed databases due to poor indexing of the topic. 996 articles were retrieved, of which 69 were initially identified as being reviews or theoretically-based. 21 of these were found to be irrelevant and 48 articles were reviewed. This narrative review focuses on defining crowdsourcing, taxonomies of crowdsourcing, who constitutes the crowd, research that is amenable to crowdsourcing, regulatory and ethical aspects of crowdsourcing and some notable examples of crowdsourcing. Crowdsourcing has the potential to be hugely promising, especially in global health, due to its ability to collect information rapidly, inexpensively and accurately. Rigorous ethical and regulatory controls are needed to ensure data are collected and analysed appropriately and crowdsourcing should be considered complementary to traditional research methods.

“Crowdsourcing” ten years in: A review

PubMed Central

Wazny, Kerri

2017-01-01

Background First coined by Howe in 2006, the field of crowdsourcing has grown exponentially. Despite its growth and its transcendence across many fields, the definition of crowdsourcing has still not been agreed upon, and examples are poorly indexed in peer–reviewed literature. Many examples of crowdsourcing have not been scaled–up past the pilot phase. In spite of this, crowdsourcing has great potential, especially in global health where resources are lacking. This narrative review seeks to review both indexed and grey crowdsourcing literature broadly in order to explore the current state of the field. Methods This is a review of reviews of crowdsourcing. Semantic searches were conducted using Google Scholar rather than indexed databases due to poor indexing of the topic. 996 articles were retrieved, of which 69 were initially identified as being reviews or theoretically–based. 21 of these were found to be irrelevant and 48 articles were reviewed. Results This narrative review focuses on defining crowdsourcing, taxonomies of crowdsourcing, who constitutes the crowd, research that is amenable to crowdsourcing, regulatory and ethical aspects of crowdsourcing and some notable examples of crowdsourcing. Conclusions Crowdsourcing has the potential to be hugely promising, especially in global health, due to its ability to collect information rapidly, inexpensively and accurately. Rigorous ethical and regulatory controls are needed to ensure data are collected and analysed appropriately and crowdsourcing should be considered complementary to traditional research methods. PMID:29302322

Evolution of the hormonal control of animal performance: Insights from the seaward migration of salmon.

PubMed

McCormick, Stephen D

2009-10-01

The endocrine system is the key mediator of environmental and developmental (internal) information, and is likely to be involved in altering the performance of animals when selection has favored phenotypic plasticity. The endocrine control of performance should be especially pronounced in animals that undergo a developmental shift in niche, such as occurs in migratory species. By way of example, I review the developmental and environmental control of the preparatory changes for seawater entry of juvenile salmon (known as smolting) and its hormonal regulation. There is a size threshold for smolt development in juvenile Atlantic salmon that results in greater sensitivity of the growth hormone and cortisol axes to changes in daylength. These hormones, in turn, have broad effects on survival, ion homeostasis, growth and swimming performance during entry into seawater. Migratory niche shifts and metamorphic events are extreme examples of the role of hormones in animal performance and represent one end of a continuum. A framework for predicting when hormones will be involved in performance of animals is presented. Endocrine involvement in performance will be more substantial when (1) selection differentials on traits underlying performance are high and temporally discontinuous over an animal's lifetime, (2) the energetic and fitness costs of maintaining performance plasticity are less than those of constant performance, (3) cues for altering performance are reliable indicators of critical environmental conditions, require neurosensory input, and minimize effects of lag, and (4) the need for coordination of organs, tissues and cells to achieve increased performance is greater. By examining these impacts of selection, endocrinologists have an opportunity to contribute to the understanding of performance, phenotypic plasticity, and the evolution of life-history traits.

Enzyme and membrane markers in leukaemia: recent developments.

PubMed Central

Hoffbrand, A V; Janossy, G

1981-01-01

Terminal deoxynucleotidyl transferase (TdT) assay has proved a valuable test for distinguishing lymphoblastic from myeloblastic leukaemias, particularly in adults whose blast cells are often negative for the c-ALL antigen. The immunofluorescence assay, particularly when used in combination with antisera to surface membrane antigens, has proved a sensitive technique for detecting small numbers of lymphoblasts in extramedullary sites, for example, testis or cerebrospinal fluid, or of residual Thy-ALL blasts in the marrow, which might otherwise be difficult to recognise. Differences in concentration of several enzymes concerned in purine metabolism have been detected between the blast cells in the various acute leukaemias. Adenosine deaminase (ADA) concentrations tend to be higher in Thy-ALL than in other forms of leukaemia, but the wide overlap reduces the diagnostic value of this assay. Thy-ALL blasts, however, appear to be selectively and exquisitely susceptible to inhibition of ADA by the drug deoxycoformycin, which has now been used sucessfully in a number of other wise resistant patients with Thy-ALL to obtain a complete remission. The recently introduced technique for the production of monoclonal antibodies has substantially widened the reagents available for analysing the membrane characteristics of bone marrow stem cells and of cell lineages derived from them. These have revealed previously unsuspected heterogeneity among different cases of acute lymphoblastic leukaemia, for example, among Thy-ALL blasts from different patients, and they have also delineated minor populations of immature thymocytes from which these leukaemic cells are derived. The potential use of these antibodies to prevent graft-versus-host disease by selective removal of T-lymphocytes from donor bone marrow before allogeneic bone marrow transplantation, or to prevent recurrence of Thy-ALL and other lymphoblastic leukaemias or lymphomas by selective removal of leukaemic or lymphoma malignant cells before autologous transplantation, is reviewed. Images Fig. 2 PMID:6785321

Evolution of the hormonal control of animal performance: insights from the seaward migration of salmon

USGS Publications Warehouse

McCormick, S.D.

2009-01-01

The endocrine system is the key mediator of environmental and developmental (internal) information, and is likely to be involved in altering the performance of animals when selection has favored phenotypic plasticity. The endocrine control of performance should be especially pronounced in animals that undergo a developmental shift in niche, such as occurs in migratory species. By way of example, I review the developmental and environmental control of the preparatory changes for seawater entry of juvenile salmon (known as smolting) and its hormonal regulation. There is a size threshold for smolt development in juvenile Atlantic salmon that results in greater sensitivity of the growth hormone and cortisol axes to changes in daylength. These hormones, in turn, have broad effects on survival, ion homeostasis, growth and swimming performance during entry into seawater. Migratory niche shifts and metamorphic events are extreme examples of the role of hormones in animal performance and represent one end of a continuum. A framework for predicting when hormones will be involved in performance of animals is presented. Endocrine involvement in performance will be more substantial when (1) selection differentials on traits underlying performance are high and temporally discontinuous over an animal's lifetime, (2) the energetic and fitness costs of maintaining performance plasticity are less than those of constant performance, (3) cues for altering performance are reliable indicators of critical environmental conditions, require neurosensory input, and minimize effects of lag, and (4) the need for coordination of organs, tissues and cells to achieve increased performance is greater. By examining these impacts of selection, endocrinologists have an opportunity to contribute to the understanding of performance, phenotypic plasticity, and the evolution of life-history traits.

Development of Benchmark Examples for Quasi-Static Delamination Propagation and Fatigue Growth Predictions

NASA Technical Reports Server (NTRS)

Krueger, Ronald

2012-01-01

The development of benchmark examples for quasi-static delamination propagation and cyclic delamination onset and growth prediction is presented and demonstrated for Abaqus/Standard. The example is based on a finite element model of a Double-Cantilever Beam specimen. The example is independent of the analysis software used and allows the assessment of the automated delamination propagation, onset and growth prediction capabilities in commercial finite element codes based on the virtual crack closure technique (VCCT). First, a quasi-static benchmark example was created for the specimen. Second, based on the static results, benchmark examples for cyclic delamination growth were created. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Fourth, starting from an initially straight front, the delamination was allowed to grow under cyclic loading. The number of cycles to delamination onset and the number of cycles during delamination growth for each growth increment were obtained from the automated analysis and compared to the benchmark examples. Again, good agreement between the results obtained from the growth analysis and the benchmark results could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Selecting the appropriate input parameters, however, was not straightforward and often required an iterative procedure. Overall the results are encouraging, but further assessment for mixed-mode delamination is required.

Development of Benchmark Examples for Static Delamination Propagation and Fatigue Growth Predictions

NASA Technical Reports Server (NTRS)

Kruger, Ronald

2011-01-01

The development of benchmark examples for static delamination propagation and cyclic delamination onset and growth prediction is presented and demonstrated for a commercial code. The example is based on a finite element model of an End-Notched Flexure (ENF) specimen. The example is independent of the analysis software used and allows the assessment of the automated delamination propagation, onset and growth prediction capabilities in commercial finite element codes based on the virtual crack closure technique (VCCT). First, static benchmark examples were created for the specimen. Second, based on the static results, benchmark examples for cyclic delamination growth were created. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Fourth, starting from an initially straight front, the delamination was allowed to grow under cyclic loading. The number of cycles to delamination onset and the number of cycles during stable delamination growth for each growth increment were obtained from the automated analysis and compared to the benchmark examples. Again, good agreement between the results obtained from the growth analysis and the benchmark results could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with the input parameters of the particular implementation. Selecting the appropriate input parameters, however, was not straightforward and often required an iterative procedure. Overall, the results are encouraging but further assessment for mixed-mode delamination is required.

Development and Application of Benchmark Examples for Mode II Static Delamination Propagation and Fatigue Growth Predictions

NASA Technical Reports Server (NTRS)

Krueger, Ronald

2011-01-01

The development of benchmark examples for static delamination propagation and cyclic delamination onset and growth prediction is presented and demonstrated for a commercial code. The example is based on a finite element model of an End-Notched Flexure (ENF) specimen. The example is independent of the analysis software used and allows the assessment of the automated delamination propagation, onset and growth prediction capabilities in commercial finite element codes based on the virtual crack closure technique (VCCT). First, static benchmark examples were created for the specimen. Second, based on the static results, benchmark examples for cyclic delamination growth were created. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Fourth, starting from an initially straight front, the delamination was allowed to grow under cyclic loading. The number of cycles to delamination onset and the number of cycles during delamination growth for each growth increment were obtained from the automated analysis and compared to the benchmark examples. Again, good agreement between the results obtained from the growth analysis and the benchmark results could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Selecting the appropriate input parameters, however, was not straightforward and often required an iterative procedure. Overall the results are encouraging, but further assessment for mixed-mode delamination is required.

Interpreting patient-reported outcomes from clinical trials in COPD: a discussion

PubMed Central

Jones, Paul W; Rennard, Stephen; Tabberer, Maggie; Riley, John H; Vahdati-Bolouri, Mitra; Barnes, Neil C

2016-01-01

One of the challenges faced by the practising physician is the interpretation of patient-reported outcomes (PROs) in clinical trials and the relevance of such data to their patients. This is especially true when caring for patients with progressive diseases such as COPD. In an attempt to incorporate the patient perspective, many clinical trials now include assessments of PROs. These are formalized methods of capturing patient-centered information. Given the importance of PROs in evaluating the potential utility of an intervention for a patient with COPD, it is important that physicians are able to critically interpret (and critique) the results derived from them. Therefore, in this paper, a series of questions is posed for the practising physician to consider when reviewing the treatment effectiveness as assessed by PROs. The focus is on the St George’s Respiratory Questionnaire for worked examples, but the principles apply equally to other symptom-based questionnaires. A number of different ways of presenting PRO data are discussed, including the concept of the minimum clinically important difference, whether there is a ceiling effect to PRO results, and the strengths and weaknesses of responder analyses. Using a worked example, the value of including a placebo arm in a study is illustrated, and the influence of the study on PRO results is considered, in terms of the design, patient withdrawal, and the selection of the study population. For the practising clinician, the most important consideration is the importance of individualization of treatment (and of treatment goals). To inform such treatment, clinicians need to critically review PRO data. The hope is that the questions posed here will help to build a framework for this critical review. PMID:27994447

Interpreting patient-reported outcomes from clinical trials in COPD: a discussion.

PubMed

Jones, Paul W; Rennard, Stephen; Tabberer, Maggie; Riley, John H; Vahdati-Bolouri, Mitra; Barnes, Neil C

2016-01-01

One of the challenges faced by the practising physician is the interpretation of patient-reported outcomes (PROs) in clinical trials and the relevance of such data to their patients. This is especially true when caring for patients with progressive diseases such as COPD. In an attempt to incorporate the patient perspective, many clinical trials now include assessments of PROs. These are formalized methods of capturing patient-centered information. Given the importance of PROs in evaluating the potential utility of an intervention for a patient with COPD, it is important that physicians are able to critically interpret (and critique) the results derived from them. Therefore, in this paper, a series of questions is posed for the practising physician to consider when reviewing the treatment effectiveness as assessed by PROs. The focus is on the St George's Respiratory Questionnaire for worked examples, but the principles apply equally to other symptom-based questionnaires. A number of different ways of presenting PRO data are discussed, including the concept of the minimum clinically important difference, whether there is a ceiling effect to PRO results, and the strengths and weaknesses of responder analyses. Using a worked example, the value of including a placebo arm in a study is illustrated, and the influence of the study on PRO results is considered, in terms of the design, patient withdrawal, and the selection of the study population. For the practising clinician, the most important consideration is the importance of individualization of treatment (and of treatment goals). To inform such treatment, clinicians need to critically review PRO data. The hope is that the questions posed here will help to build a framework for this critical review.

Active learning strategies for the deduplication of electronic patient data using classification trees.

PubMed

Sariyar, M; Borg, A; Pommerening, K

2012-10-01

Supervised record linkage methods often require a clerical review to gain informative training data. Active learning means to actively prompt the user to label data with special characteristics in order to minimise the review costs. We conducted an empirical evaluation to investigate whether a simple active learning strategy using binary comparison patterns is sufficient or if string metrics together with a more sophisticated algorithm are necessary to achieve high accuracies with a small training set. Based on medical registry data with different numbers of attributes, we used active learning to acquire training sets for classification trees, which were then used to classify the remaining data. Active learning for binary patterns means that every distinct comparison pattern represents a stratum from which one item is sampled. Active learning for patterns consisting of the Levenshtein string metric values uses an iterative process where the most informative and representative examples are added to the training set. In this context, we extended the active learning strategy by Sarawagi and Bhamidipaty (2002). On the original data set, active learning based on binary comparison patterns leads to the best results. When dropping four or six attributes, using string metrics leads to better results. In both cases, not more than 200 manually reviewed training examples are necessary. In record linkage applications where only forename, name and birthday are available as attributes, we suggest the sophisticated active learning strategy based on string metrics in order to achieve highly accurate results. We recommend the simple strategy if more attributes are available, as in our study. In both cases, active learning significantly reduces the amount of manual involvement in training data selection compared to usual record linkage settings. Copyright © 2012 Elsevier Inc. All rights reserved.

Meso-Mechanics and Meso-Structures: A Matter of Scale

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Gotsis, P. K.; Mital, S. K.

1998-01-01

Meso-mechanics and meso-structures are described in terms of the scales at which they are observed and formulated. Select composite examples are presented to illustrate that meso-mechanics and/or meso-structures are meaningful only when they refer to a specific scale in a hierarchical scale observation/simulation. These examples include different types of composite unit cells, woven fabric unit cells, and progressive fracture as a composite enhanced infrastructure made from reinforced concrete. The results from the select examples indicate that meso-mechanics and meso-structures are elusive terms and depend mainly on the investigators' knowledge and available information.

Flat-panel display solutions for ground-environment military displays (Invited Paper)

NASA Astrophysics Data System (ADS)

Thomas, J., II; Roach, R.

2005-05-01

Displays for military vehicles have very distinct operational and cost requirements that differ from other military applications. These requirements demand that display suppliers to Army and Marine ground-environments provide low cost equipment that is capable of operation across environmental extremes. Inevitably, COTS components form the foundation of these "affordable" display solutions. This paper will outline the major display requirements and review the options that satisfy conflicting and difficult operational demands, using newly developed equipment as an example. Recently, a new supplier was selected for the Drivers Vision Enhancer (DVE) equipment, including the Display Control Module (DCM). The paper will outline the DVE and describe development of a new DCM solution. The DVE programme, with several thousand units presently in service and operational in conflicts such as "Operation Iraqi Freedom", represents a critical balance between cost and performance. We shall describe design considerations that include selection of COTS sources, the need to minimise display modification; video interfaces, power interfaces, operator interfaces and new provisions to optimise displayed video content.

Symbiosis and development: the hologenome concept.

PubMed

Rosenberg, Eugene; Zilber-Rosenberg, Ilana

2011-03-01

All animals and plants establish symbiotic relationships with microorganisms; often the combined genetic information of the diverse microbiota exceeds that of the host. How the genetic wealth of the microbiota affects all aspects of the holobiont's (host plus all of its associated microorganisms) fitness (adaptation, survival, development, growth and reproduction) and evolution is reviewed, using selected coral, insect, squid, plant, and human/mouse published experimental results. The data are discussed within the framework of the hologenome theory of evolution, which demonstrates that changes in environmental parameters, for example, diet, can cause rapid changes in the diverse microbiota, which not only can benefit the holobiont in the short term but also can be transmitted to offspring and lead to long lasting cooperations. As acquired characteristics (microbes) are heritable, consideration of the holobiont as a unit of selection in evolution leads to neo-Lamarckian principles within a Darwinian framework. The potential application of these principles can be seen in the growing fields of prebiotics and probiotics. Copyright © 2011 Wiley-Liss, Inc.

Fluorescent in vivo imaging of reactive oxygen species and redox potential in plants.

PubMed

Ortega-Villasante, Cristina; Burén, Stefan; Blázquez-Castro, Alfonso; Barón-Sola, Ángel; Hernández, Luis E

2018-04-05

Reactive oxygen species (ROS) are by-products of aerobic metabolism, and excessive production can result in oxidative stress and cell damage. In addition, ROS function as cellular messengers, working as redox regulators in a multitude of biological processes. Understanding ROS signalling and stress responses requires methods for precise imaging and quantification to monitor local, subcellular and global ROS dynamics with high selectivity, sensitivity and spatiotemporal resolution. In this review, we summarize the present knowledge for in vivo plant ROS imaging and detection, using both chemical probes and fluorescent protein-based biosensors. Certain characteristics of plant tissues, for example high background autofluorescence in photosynthetic organs and the multitude of endogenous antioxidants, can interfere with ROS and redox potential detection, making imaging extra challenging. Novel methods and techniques to measure in vivo plant ROS and redox changes with better selectivity, accuracy, and spatiotemporal resolution are therefore desirable to fully acknowledge the remarkably complex plant ROS signalling networks. Copyright © 2018 Elsevier Inc. All rights reserved.

The control of stoichiometry in Epitaxial semiconductor structures. Interfacial Chemistry: Property relations. A workshop review

NASA Technical Reports Server (NTRS)

Bachmann, Klaus J.

1995-01-01

A workshop on the control of stoichiometry in epitaxial semiconductor structures was held on August 21-26, 1995 in the hotel Stutenhaus at Vesser in Germany. The secluded location of the workshop in the forest of Thuringia and its informal style stimulated extensive private discussions among the participants and promoted new contacts between young scientists from Eastern and Western Europe and the USA. Topics addressed by the presentations were interactions of precursors to heteroepitaxy and doping with the substrate surface, the control of interfacial properties under the conditions of heteroepitaxy for selected materials systems, methods of characterization of interfaces and native point defects in semiconductor heterostructures and an in depth evaluation of the present status of the control and characterization of the point defect chemistry for one specific semiconductor (ZnGeP2), including studies of both heterostructures and bulk single crystals. The selected examples of presentations and comments given here represent individual choices - made by the author to highlight major points of the discussions.

Rapid bursts and slow declines: on the possible evolutionary trajectories of enzymes.

PubMed

Newton, Matilda S; Arcus, Vickery L; Patrick, Wayne M

2015-06-06

The evolution of enzymes is often viewed as following a smooth and steady trajectory, from barely functional primordial catalysts to the highly active and specific enzymes that we observe today. In this review, we summarize experimental data that suggest a different reality. Modern examples, such as the emergence of enzymes that hydrolyse human-made pesticides, demonstrate that evolution can be extraordinarily rapid. Experiments to infer and resurrect ancient sequences suggest that some of the first organisms present on the Earth are likely to have possessed highly active enzymes. Reconciling these observations, we argue that rapid bursts of strong selection for increased catalytic efficiency are interspersed with much longer periods in which the catalytic power of an enzyme erodes, through neutral drift and selection for other properties such as cellular energy efficiency or regulation. Thus, many enzymes may have already passed their catalytic peaks. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Marker-assisted selection: an approach for precision plant breeding in the twenty-first century.

PubMed

Collard, Bertrand C Y; Mackill, David J

2008-02-12

DNA markers have enormous potential to improve the efficiency and precision of conventional plant breeding via marker-assisted selection (MAS). The large number of quantitative trait loci (QTLs) mapping studies for diverse crops species have provided an abundance of DNA marker-trait associations. In this review, we present an overview of the advantages of MAS and its most widely used applications in plant breeding, providing examples from cereal crops. We also consider reasons why MAS has had only a small impact on plant breeding so far and suggest ways in which the potential of MAS can be realized. Finally, we discuss reasons why the greater adoption of MAS in the future is inevitable, although the extent of its use will depend on available resources, especially for orphan crops, and may be delayed in less-developed countries. Achieving a substantial impact on crop improvement by MAS represents the great challenge for agricultural scientists in the next few decades.

From Oedipus to PACE, using the concepts of shame and guilt as golden thread.

PubMed

Beckmann, Klaus Martin

2016-02-01

To demonstrate that antiquity's concepts of shame and guilt developed in their meaning over the centuries and can still have practical applicability in psychological therapies these days. To review shame and guilt in philosophy, history, ethics and psychiatry contexts. Within limitations, a narrative is presented, starting with Oedipus in antiquity, visiting several important philosophical theories and ending in the present time with, for example, Dan Hughes' PACE model for therapy. The first part expands on selected ideas presented in Melvyn Bragg's 2007 BBC radio programme entitled 'Guilt'; the second part adds selected therapeutic models where concepts of shame and guilt play a role. Shame and guilt are archaic but quintessential concepts that already occupied thinkers in antiquity. Shame and guilt are concepts that preoccupied science and art over the millennia and continue as useful concepts to the present day. Moreover, shame and guilt, as concepts, continue to play a salient role in recent and contemporary psychiatry. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Copper metallothioneins.

PubMed

Calvo, Jenifer; Jung, Hunmin; Meloni, Gabriele

2017-04-01

Metallothioneins (MTs) are a class of low molecular weight and cysteine-rich metal binding proteins present in all the branches of the tree of life. MTs efficiently bind with high affinity several essential and toxic divalent and monovalent transition metals by forming characteristic polynuclear metal-thiolate clusters within their structure. MTs fulfil multiple biological functions related to their metal binding properties, with essential roles in both Zn(II) and Cu(I) homeostasis as well as metal detoxification. Depending on the organism considered, the primary sequence, and the specific physiological and metabolic status, Cu(I)-bound MT isoforms have been isolated, and their chemistry and biology characterized. Besides the recognized role in the biochemistry of divalent metals, it is becoming evident that unique biological functions in selectively controlling copper levels, its reactivity as well as copper-mediated biochemical processes have evolved in some members of the MT superfamily. Selected examples are reviewed to highlight the peculiar chemical properties and biological functions of copper MTs. © 2016 IUBMB Life, 69(4):236-245, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Evolving phenotypic networks in silico.

PubMed

François, Paul

2014-11-01

Evolved gene networks are constrained by natural selection. Their structures and functions are consequently far from being random, as exemplified by the multiple instances of parallel/convergent evolution. One can thus ask if features of actual gene networks can be recovered from evolutionary first principles. I review a method for in silico evolution of small models of gene networks aiming at performing predefined biological functions. I summarize the current implementation of the algorithm, insisting on the construction of a proper "fitness" function. I illustrate the approach on three examples: biochemical adaptation, ligand discrimination and vertebrate segmentation (somitogenesis). While the structure of the evolved networks is variable, dynamics of our evolved networks are usually constrained and present many similar features to actual gene networks, including properties that were not explicitly selected for. In silico evolution can thus be used to predict biological behaviours without a detailed knowledge of the mapping between genotype and phenotype. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

Magnetic resonance imaging of chemistry.

PubMed

Britton, Melanie M

2010-11-01

Magnetic resonance imaging (MRI) has long been recognized as one of the most important tools in medical diagnosis and research. However, MRI is also well placed to image chemical reactions and processes, determine the concentration of chemical species, and look at how chemistry couples with environmental factors, such as flow and heterogeneous media. This tutorial review will explain how magnetic resonance imaging works, reviewing its application in chemistry and its ability to directly visualise chemical processes. It will give information on what resolution and contrast are possible, and what chemical and physical parameters can be measured. It will provide examples of the use of MRI to study chemical systems, its application in chemical engineering and the identification of contrast agents for non-clinical applications. A number of studies are presented including investigation of chemical conversion and selectivity in fixed-bed reactors, temperature probes for catalyst pellets, ion mobility during tablet dissolution, solvent dynamics and ion transport in Nafion polymers and the formation of chemical waves and patterns.

Metal-Mediated Halogen Exchange in Aryl and Vinyl Halides: A Review

PubMed Central

Evano, Gwilherm; Nitelet, Antoine; Thilmany, Pierre; Dewez, Damien F.

2018-01-01

Halogenated arenes and alkenes are of prime importance in many areas of science, especially in the pharmaceutical, agrochemical, and chemical industries. While the simplest ones are commercially available, some of them are still hardly accessible depending on their substitution patterns and the nature of the halogen atom. Reactions enabling the selective and efficient replacement of the halogen atom of an aryl or alkenyl halide by another one, lighter, or heavier, are therefore of major importance since they can be used for example to turn a less reactive aryl/alkenyl chloride into the more reactive iodinated derivatives or, in a reversed sense, to block an undesired reactivity, for late-stage modifications or for the introduction of a radionuclide. If some halogen exchange reactions are possible with activated substrates, they usually require catalysis with metal complexes. Remarkably efficient processes have been developed for metal-mediated halogen exchange in aryl and vinyl halides: they are overviewed, in a comprehensive manner, in this review article. PMID:29755967

Impact damage resistance and damage suppression properties of shape memory alloys in hybrid composites—a review

NASA Astrophysics Data System (ADS)

Angioni, S. L.; Meo, M.; Foreman, A.

2011-01-01

Composite materials are known to have a poor resistance to through-the-thickness impact loading. There are various methods for improving their impact damage tolerance, such as fiber toughening, matrix toughening, interface toughening, through-the-thickness reinforcements, and selective interlayers and hybrids. Hybrid composites with improved impact resistance are particularly useful in military and commercial civil applications. Hybridizing composites using shape memory alloys (SMA) is one solution since SMA materials can absorb the energy of the impact through superelastic deformation or recovery stress, reducing the effects of the impact on the composite structure. The SMA material may be embedded in the hybrid composites (SMAHC) in many different forms and also the characteristics of the fiber reinforcements may vary, such as SMA wires in woven laminates or SMA foils in unidirectional laminates, only to cite two examples. We will review the state of the art of SMAHC for the purpose of damage suppression. Both the active and passive damage suppression mechanisms will be considered.

Electron microscopy for ultrastructural analysis and protein localization in Saccharomyces cerevisiae

PubMed Central

Frankl, Andri; Mari, Muriel; Reggiori, Fulvio

2015-01-01

The yeast Saccharomyces cerevisiae is a key model system for studying of a multitude of cellular processes because of its amenability to genetics, molecular biology and biochemical procedures. Ultrastructural examinations of this organism, though, are traditionally difficult because of the presence of a thick cell wall and the high density of cytoplasmic proteins. A series of recent methodological and technical developments, however, has revived interest in morphological analyses of yeast (e.g. 123). Here we present a review of established and new methods, from sample preparation to imaging, for the ultrastructural analysis of S. cerevisiae. We include information for the use of different fixation methods, embedding procedures, approaches for contrast enhancement, and sample visualization techniques, with references to successful examples. The goal of this review is to guide researchers that want to investigate a particular process at the ultrastructural level in yeast by aiding in the selection of the most appropriate approach to visualize a specific structure or subcellular compartment. PMID:28357267

Functions of intrinsic disorder in transmembrane proteins.

PubMed

Kjaergaard, Magnus; Kragelund, Birthe B

2017-09-01

Intrinsic disorder is common in integral membrane proteins, particularly in the intracellular domains. Despite this observation, these domains are not always recognized as being disordered. In this review, we will discuss the biological functions of intrinsically disordered regions of membrane proteins, and address why the flexibility afforded by disorder is mechanistically important. Intrinsically disordered regions are present in many common classes of membrane proteins including ion channels and transporters; G-protein coupled receptors (GPCRs), receptor tyrosine kinases and cytokine receptors. The functions of the disordered regions are many and varied. We will discuss selected examples including: (1) Organization of receptors, kinases, phosphatases and second messenger sources into signaling complexes. (2) Modulation of the membrane-embedded domain function by ball-and-chain like mechanisms. (3) Trafficking of membrane proteins. (4) Transient membrane associations. (5) Post-translational modifications most notably phosphorylation and (6) disorder-linked isoform dependent function. We finish the review by discussing the future challenges facing the membrane protein community regarding protein disorder.

Morphology engineering of high performance binary oxide electrodes.

PubMed

Chen, Kunfeng; Sun, Congting; Xue, Dongfeng

2015-01-14

Advances in materials have preceded almost every major technological leap since the beginning of civilization. On the nanoscale and microscale, mastery over the morphology, size, and structure of a material enables control of its properties and enhancement of its usefulness for a given application, such as energy storage. In this review paper, our aim is to present a review of morphology engineering of high performance oxide electrode materials for electrochemical energy storage. We begin with the chemical bonding theory of single crystal growth to direct the growth of morphology-controllable materials. We then focus on the growth of various morphologies of binary oxides and their electrochemical performances for lithium ion batteries and supercapacitors. The morphology-performance relationships are elaborated by selecting examples in which there is already reasonable understanding for this relationship. Based on these comprehensive analyses, we proposed colloidal supercapacitor systems beyond morphology control on the basis of system- and ion-level design. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Developing a quality assurance program for online services.

PubMed Central

Humphries, A W; Naisawald, G V

1991-01-01

A quality assurance (QA) program provides not only a mechanism for establishing training and competency standards, but also a method for continuously monitoring current service practices to correct shortcomings. The typical QA cycle includes these basic steps: select subject for review, establish measurable standards, evaluate existing services using the standards, identify problems, implement solutions, and reevaluate services. The Claude Moore Health Sciences Library (CMHSL) developed a quality assurance program for online services designed to evaluate services against specific criteria identified by research studies as being important to customer satisfaction. These criteria include reliability, responsiveness, approachability, communication, and physical factors. The application of these criteria to the library's existing online services in the quality review process is discussed with specific examples of the problems identified in each service area, as well as the solutions implemented to correct deficiencies. The application of the QA cycle to an online services program serves as a model of possible interventions. The use of QA principles to enhance online service quality can be extended to other library service areas. PMID:1909197

Resistance to bio-insecticides or how to enhance their sustainability: a review

PubMed Central

Siegwart, Myriam; Graillot, Benoit; Blachere Lopez, Christine; Besse, Samantha; Bardin, Marc; Nicot, Philippe C.; Lopez-Ferber, Miguel

2015-01-01

After more than 70 years of chemical pesticide use, modern agriculture is increasingly using biological control products. Resistances to conventional insecticides are wide spread, while those to bio-insecticides have raised less attention, and resistance management is frequently neglected. However, a good knowledge of the limitations of a new technique often provides greater sustainability. In this review, we compile cases of resistance to widely used bio-insecticides and describe the associated resistance mechanisms. This overview shows that all widely used bio-insecticides ultimately select resistant individuals. For example, at least 27 species of insects have been described as resistant to Bacillus thuringiensis toxins. The resistance mechanisms are at least as diverse as those that are involved in resistance to chemical insecticides, some of them being common to bio-insecticides and chemical insecticides. This analysis highlights the specific properties of bio-insecticides that the scientific community should use to provide a better sustainability of these products. PMID:26150820

Developing a quality assurance program for online services.

PubMed

Humphries, A W; Naisawald, G V

1991-07-01

A quality assurance (QA) program provides not only a mechanism for establishing training and competency standards, but also a method for continuously monitoring current service practices to correct shortcomings. The typical QA cycle includes these basic steps: select subject for review, establish measurable standards, evaluate existing services using the standards, identify problems, implement solutions, and reevaluate services. The Claude Moore Health Sciences Library (CMHSL) developed a quality assurance program for online services designed to evaluate services against specific criteria identified by research studies as being important to customer satisfaction. These criteria include reliability, responsiveness, approachability, communication, and physical factors. The application of these criteria to the library's existing online services in the quality review process is discussed with specific examples of the problems identified in each service area, as well as the solutions implemented to correct deficiencies. The application of the QA cycle to an online services program serves as a model of possible interventions. The use of QA principles to enhance online service quality can be extended to other library service areas.

Measuring Mindreading: A Review of Behavioral Approaches to Testing Cognitive and Affective Mental State Attribution in Neurologically Typical Adults.

PubMed

Turner, Rose; Felisberti, Fatima M

2017-01-01

Mindreading refers to the ability to attribute mental states, including thoughts, intentions and emotions, to oneself and others, and is essential for navigating the social world. Empirical mindreading research has predominantly featured children, groups with autism spectrum disorder and clinical samples, and many standard tasks suffer ceiling effects with neurologically typical (NT) adults. We first outline a case for studying mindreading in NT adults and proceed to review tests of emotion perception, cognitive and affective mentalizing, and multidimensional tasks combining these facets. We focus on selected examples of core experimental paradigms including emotion recognition tests, social vignettes, narrative fiction (prose and film) and participative interaction (in real and virtual worlds), highlighting challenges for studies with NT adult cohorts. We conclude that naturalistic, multidimensional approaches may be productively applied alongside traditional tasks to facilitate a more nuanced picture of mindreading in adulthood, and to ensure construct validity whilst remaining sensitive to variation at the upper echelons of the ability.

How Genetically Engineered Mouse Tumor Models Provide Insights Into Human Cancers

PubMed Central

Politi, Katerina; Pao, William

2011-01-01

Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review. PMID:21263096

[Fall prevention counselling for patients with hearing and balance disorders].

PubMed

Ptok, M; Ptok, A; Jungheim, M; Kühn, D; Miller, S

2014-09-01

Otolaryngologists caring for patients with hearing and balance disorders are also responsible for advising patients about their increased risk of falling and informing them of fall prevention measures. This review will give a brief overview of appropriate programs. This systematic review is based on a selective literature search. Intrinsic and extrinsic fall risk factors can be distinguished. The former include not only hearing and balance disorders, but also increasing age, nocturia, dementia, limited mobility and poor nutritional status. Extrinsic factors include, for example, unfixed carpet edges, poor lighting and poor footwear. Fall prevention can be achieved through appropriate counselling about risk factors and fall prevention courses. The frequency of falls--with potentially very adverse consequences--increases continuously beyond the age of 60 years. Furthermore, the risk of falling is significantly increased in patients with hearing and balance disorders. Otolaryngologists caring for this patient group should inform them about their fall risk and advise appropriate countermeasures during counselling. A basal knowledge of fall prevention measures is therefore helpful.

Combustion Research Aboard the ISS Utilizing the Combustion Integrated Rack and Microgravity Science Glovebox

NASA Technical Reports Server (NTRS)

Sutliff, Thomas J.; Otero, Angel M.; Urban, David L.

2002-01-01

The Physical Sciences Research Program of NASA sponsors a broad suite of peer-reviewed research investigating fundamental combustion phenomena and applied combustion research topics. This research is performed through both ground-based and on-orbit research capabilities. The International Space Station (ISS) and two facilities, the Combustion Integrated Rack and the Microgravity Science Glovebox, are key elements in the execution of microgravity combustion flight research planned for the foreseeable future. This paper reviews the Microgravity Combustion Science research planned for the International Space Station implemented from 2003 through 2012. Examples of selected research topics, expected outcomes, and potential benefits will be provided. This paper also summarizes a multi-user hardware development approach, recapping the progress made in preparing these research hardware systems. Within the description of this approach, an operational strategy is presented that illustrates how utilization of constrained ISS resources may be maximized dynamically to increase science through design decisions made during hardware development.

Measuring Mindreading: A Review of Behavioral Approaches to Testing Cognitive and Affective Mental State Attribution in Neurologically Typical Adults

PubMed Central

Turner, Rose; Felisberti, Fatima M.

2017-01-01

Mindreading refers to the ability to attribute mental states, including thoughts, intentions and emotions, to oneself and others, and is essential for navigating the social world. Empirical mindreading research has predominantly featured children, groups with autism spectrum disorder and clinical samples, and many standard tasks suffer ceiling effects with neurologically typical (NT) adults. We first outline a case for studying mindreading in NT adults and proceed to review tests of emotion perception, cognitive and affective mentalizing, and multidimensional tasks combining these facets. We focus on selected examples of core experimental paradigms including emotion recognition tests, social vignettes, narrative fiction (prose and film) and participative interaction (in real and virtual worlds), highlighting challenges for studies with NT adult cohorts. We conclude that naturalistic, multidimensional approaches may be productively applied alongside traditional tasks to facilitate a more nuanced picture of mindreading in adulthood, and to ensure construct validity whilst remaining sensitive to variation at the upper echelons of the ability. PMID:28174552

Least squares polynomial chaos expansion: A review of sampling strategies

NASA Astrophysics Data System (ADS)

Hadigol, Mohammad; Doostan, Alireza

2018-04-01

As non-institutive polynomial chaos expansion (PCE) techniques have gained growing popularity among researchers, we here provide a comprehensive review of major sampling strategies for the least squares based PCE. Traditional sampling methods, such as Monte Carlo, Latin hypercube, quasi-Monte Carlo, optimal design of experiments (ODE), Gaussian quadratures, as well as more recent techniques, such as coherence-optimal and randomized quadratures are discussed. We also propose a hybrid sampling method, dubbed alphabetic-coherence-optimal, that employs the so-called alphabetic optimality criteria used in the context of ODE in conjunction with coherence-optimal samples. A comparison between the empirical performance of the selected sampling methods applied to three numerical examples, including high-order PCE's, high-dimensional problems, and low oversampling ratios, is presented to provide a road map for practitioners seeking the most suitable sampling technique for a problem at hand. We observed that the alphabetic-coherence-optimal technique outperforms other sampling methods, specially when high-order ODE are employed and/or the oversampling ratio is low.

Metal-Mediated Halogen Exchange in Aryl and Vinyl Halides: a Review

NASA Astrophysics Data System (ADS)

Evano, Gwilherm; Nitelet, Antoine; Thilmany, Pierre; Dewez, Damien F.

2018-04-01

Halogenated arenes and alkenes are of prime importance in many areas of science, especially in the pharmaceutical, agrochemical and chemical industries. While the simplest ones are commercially available, some of them are still hardly accessible depending on their substitution patterns and the nature of the halogen atom. Reactions enabling the selective and efficient replacement of the halogen atom of an aryl or alkenyl halide by another one, lighter or heavier, are therefore of major importance since they can be used for example to turn a less reactive aryl/alkenyl chloride into the more reactive iodinated derivatives or, in a reversed sense, to block an undesired reactivity, for late-stage modifications or for the introduction of a radionuclide. If some halogen exchange reactions are possible with activated substrates, they usually require catalysis with metal complexes. Remarkably efficient processes have been developed for metal-mediated halogen exchange in aryl and vinyl halides: they are overviewed, in a comprehensive manner, in this review article.

Recent advances in CE-MS coupling: Instrumentation, methodology, and applications.

PubMed

Týčová, Anna; Ledvina, Vojtěch; Klepárník, Karel

2017-01-01

This review focuses on the latest development of microseparation electromigration methods in capillaries and microfluidic devices coupled with MS for detection and identification of important analytes. It is a continuation of the review article on the same topic by Kleparnik (Electrophoresis 2015, 36, 159-178). A wide selection of 161 relevant articles covers the literature published from June 2014 till May 2016. New improvements in the instrumentation and methodology of MS interfaced with capillary or microfluidic versions of zone electrophoresis, isotachophoresis, and isoelectric focusing are described in detail. The most frequently implemented MS ionization methods include electrospray ionization, matrix-assisted desorption/ionization and inductively coupled plasma ionization. Although the main attention is paid to the development of instrumentation and methodology, representative examples illustrate also applications in the proteomics, glycomics, metabolomics, biomarker research, forensics, pharmacology, food analysis, and single-cell analysis. The combinations of MS with capillary versions of electrochromatography, and micellar electrokinetic chromatography are not included. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-extinction through optimizing selection.

PubMed

Parvinen, Kalle; Dieckmann, Ulf

2013-09-21

Evolutionary suicide is a process in which selection drives a viable population to extinction. So far, such selection-driven self-extinction has been demonstrated in models with frequency-dependent selection. This is not surprising, since frequency-dependent selection can disconnect individual-level and population-level interests through environmental feedback. Hence it can lead to situations akin to the tragedy of the commons, with adaptations that serve the selfish interests of individuals ultimately ruining a population. For frequency-dependent selection to play such a role, it must not be optimizing. Together, all published studies of evolutionary suicide have created the impression that evolutionary suicide is not possible with optimizing selection. Here we disprove this misconception by presenting and analyzing an example in which optimizing selection causes self-extinction. We then take this line of argument one step further by showing, in a further example, that selection-driven self-extinction can occur even under frequency-independent selection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Soft 2D nanoarchitectonics

NASA Astrophysics Data System (ADS)

Ariga, Katsuhiko; Watanabe, Shun; Mori, Taizo; Takeya, Jun

2018-04-01

Nanoarchitectonics is a new paradigm to combine and unify nanotechnology with other sciences and technologies, such as supramolecular chemistry, self-assembly, self-organization, materials technology for manipulation of the size of material objects, and even biotechnology for hybridization with bio-components. The nanoarchitectonic concept leads to the synergistic combination of various methodologies in materials production, including atomic/molecular-level control, self-organization, and field-controlled organization. The focus of this review is on soft 2D nanoarchitectonics. Scientific views on soft 2D nanomaterials are not fully established compared with those on rigid 2D materials. Here, we collect recent examples of 2D nanoarchitectonic constructions of functional materials and systems with soft components. These examples are selected according to the following three categories on the basis of 2D spatial density and motional freedom: (i) well-packed and oriented organic 2D materials with rational design of component molecules and device applications, (ii) well-defined assemblies with 2D porous structures as 2D network materials, and (iii) 2D control of molecular machines and receptors on the basis of certain motional freedom confined in two dimensions.

The role of lipids in host microbe interactions.

PubMed

Lang, Roland; Mattner, Jochen

2017-06-01

Lipids are one of the major subcellular constituents and serve as signal molecules, energy sources, metabolic precursors and structural membrane components in various organisms. The function of lipids can be modified by multiple biochemical processes such as (de-)phosphorylation or (de-)glycosylation, and the organization of fatty acids into distinct cellular pools and subcellular compartments plays a pivotal role for the morphology and function of various cell populations. Thus, lipids regulate, for example, phagosome formation and maturation within host cells and thus, are critical for the elimination of microbial pathogens. Vice versa, microbial pathogens can manipulate the lipid composition of phagosomal membranes in host cells, and thus avoid their delivery to phagolysosomes. Lipids of microbial origin belong also to the strongest and most versatile inducers of mammalian immune responses upon engagement of distinct receptors on myeloid and lymphoid cells. Furthermore, microbial lipid toxins can induce membrane injuries and cell death. Thus, we will review here selected examples for mutual host-microbe interactions within the broad and divergent universe of lipids in microbial defense, tissue injury and immune evasion.

Future Directions for Hypothermia following Severe Traumatic Brian Injury.

PubMed

Chiu, Annie W; Hinson, Holly E

2017-12-01

Traumatic brain injury (TBI) is a serious health care problem on both individual and public health levels. As a major cause of death and disability in the United States, it is associated with a significant economic and public health burden. Although the evidence to support the use of induced hypothermia on neurologic outcome after cardiac arrest is well established, its use in treating TBI remains controversial. Hypothermia has the potential to mitigate some of the destructive processes that occur as part of secondary brain injury after TBI. Hypothermia can be helpful in lowering intracranial pressure, for example, but its influence on functional outcome is unclear. There is insufficient evidence to support the broad use of prophylactic hypothermia for neuroprotection after TBI. Investigators are beginning to more carefully select patients for temperature modulating therapies, in a more personalized approach. Examples include targeting immunomodulation and scaling hypothermia to achieve metabolic targets. This review will summarize the clinical evidence for the use of hypothermia to limit secondary brain injury following acute TBI. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Macroergonomics in Healthcare Quality and Patient Safety

PubMed Central

Carayon, Pascale; Karsh, Ben-Tzion; Gurses, Ayse P.; Holden, Richard; Hoonakker, Peter; Hundt, Ann Schoofs; Montague, Enid; Rodriguez, Joy; Wetterneck, Tosha B.

2014-01-01

The US Institute of Medicine and healthcare experts have called for new approaches to manage healthcare quality problems. In this chapter, we focus on macroergonomics, a branch of human factors and ergonomics that is based on the systems approach and considers the organizational and sociotechnical context of work activities and processes. Selected macroergonomic approaches to healthcare quality and patient safety are described such as the SEIPS model of work system and patient safety and the model of healthcare professional performance. Focused reviews on job stress and burnout, workload, interruptions, patient-centered care, health IT and medical devices, violations, and care coordination provide examples of macroergonomics contributions to healthcare quality and patient safety. Healthcare systems and processes clearly need to be systematically redesigned; examples of macroergonomic approaches, principles and methods for healthcare system redesign are described. Further research linking macroergonomics and care processes/patient outcomes is needed. Other needs for macroergonomics research are highlighted, including understanding the link between worker outcomes (e.g., safety and well-being) and patient outcomes (e.g., patient safety), and macroergonomics of patient-centered care and care coordination. PMID:24729777

Engineering microbial chemical factories to produce renewable "biomonomers".

PubMed

Adkins, Jake; Pugh, Shawn; McKenna, Rebekah; Nielsen, David R

2012-01-01

By applying metabolic engineering tools and strategies to engineer synthetic enzyme pathways, the number and diversity of commodity and specialty chemicals that can be derived directly from renewable feedstocks is rapidly and continually expanding. This of course includes a number of monomer building-block chemicals that can be used to produce replacements to many conventional plastic materials. This review aims to highlight numerous recent and important advancements in the microbial production of these so-called "biomonomers." Relative to naturally-occurring renewable bioplastics, biomonomers offer several important advantages, including improved control over the final polymer structure and purity, the ability to synthesize non-natural copolymers, and allowing products to be excreted from cells which ultimately streamlines downstream recovery and purification. To highlight these features, a handful of biomonomers have been selected as illustrative examples of recent works, including polyamide monomers, styrenic vinyls, hydroxyacids, and diols. Where appropriate, examples of their industrial penetration to date and end-product uses are also highlighted. Novel biomonomers such as these are ultimately paving the way toward new classes of renewable bioplastics that possess a broader diversity of properties than ever before possible.

Biomimetics--using nature to inspire human innovation.

PubMed

Bar-Cohen, Yoseph

2006-03-01

Evolution has resolved many of nature's challenges leading to lasting solutions. Nature has always inspired human achievements and has led to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits (Bar-Cohen Y (ed) 2005 Biomimetics-Biologically Inspired Technologies (Boca Raton, FL: CRC Press) pp 1-552). This field, which is known as biomimetics, offers enormous potential for inspiring new capabilities for exciting future technologies. There are numerous examples of biomimetic successes that involve making simple copies, such as the use of fins for swimming. Others examples involved greater mimicking complexity including the mastery of flying that became possible only after the principles of aerodynamics were better understood. Some commercial implementations of biomimetics, including robotic toys and movie subjects, are increasingly appearing and behaving like living creatures. More substantial benefits of biomimetics include the development of prosthetics that closely mimic real limbs and sensory-enhancing microchips that are interfaced with the brain to assist in hearing, seeing and controlling instruments. A review is given of selected areas that were inspired by nature, and an outlook for potential development in biomimetics is presented.

Environmental injustice: case studies from the South

NASA Astrophysics Data System (ADS)

Cifuentes, Enrique; Frumkin, Howard

2007-10-01

We selected three case studies to illustrate environmental injustice issues in the South. These examples relate to migrant agricultural workers, the maquiladora industry and artisanal mining, while reviewing some of the major mechanisms involved, e.g. multinational corporations, the development of free trade zones, multilateral free trade agreements and the export of hazards. A series of strategies are discussed in order to address environmental injustice and health disparities that exist on a global scale. Some of the recommendations involve policy initiatives; others, such as research and mentorship, fall within the traditional domain of public health practice. In this paper, special attention is given to concerned environmental and occupational health professionals using evidence-based data for advocacy. For lasting changes to be made, however, stronger institutions and legislation are required. Those who have the 'right to know' about environmental injustice issues include communities of concern, workers' representatives and lawyers. Government officials and company officials may eventually work on the basis of conflict resolution, compensation and remediation, to quote some examples. Systematic approaches to protect both the environment and public health must be updated.

Pathophysiology of isoprostanes in the cardiovascular system: implications of isoprostane-mediated thromboxane A2 receptor activation

PubMed Central

Bauer, Jochen; Ripperger, Anne; Frantz, Stefan; Ergün, Süleyman; Schwedhelm, Edzard; Benndorf, Ralf A

2014-01-01

Isoprostanes are free radical-catalysed PG-like products of unsaturated fatty acids, such as arachidonic acid, which are widely recognized as reliable markers of systemic lipid peroxidation and oxidative stress in vivo. Moreover, activation of enzymes, such as COX-2, may contribute to isoprostane formation. Indeed, formation of isoprostanes is considerably increased in various diseases which have been linked to oxidative stress, such as cardiovascular disease (CVD), and may predict the atherosclerotic burden and the risk of cardiovascular complications in the latter patients. In addition, several isoprostanes may directly contribute to the functional consequences of oxidant stress via activation of the TxA2 prostanoid receptor (TP), for example, by affecting endothelial cell function and regeneration, vascular tone, haemostasis and ischaemia/reperfusion injury. In this context, experimental and clinical data suggest that selected isoprostanes may represent important alternative activators of the TP receptor when endogenous TxA2 levels are low, for example, in aspirin-treated individuals with CVD. In this review, we will summarize the current understanding of isoprostane formation, biochemistry and (patho) physiology in the cardiovascular context. PMID:24646155

Recycling of polymers: a review.

PubMed

Ignatyev, Igor A; Thielemans, Wim; Vander Beke, Bob

2014-06-01

Plastics are inexpensive, easy to mold, and lightweight. These and many other advantages make them very promising candidates for commercial applications. In many areas, they have substantially suppressed traditional materials. However, the problem of recycling still is a major challenge. There are both technological and economic issues that restrain the progress in this field. Herein, a state-of-art overview of recycling is provided together with an outlook for the future by using popular polymers such as polyolefins, poly(vinyl chloride), polyurethane, and poly(ethylene terephthalate) as examples. Different types of recycling, primary, secondary, tertiary, quaternary, and biological recycling, are discussed together with related issues, such as compatibilization and cross-linking. There are various projects in the European Union on research and application of these recycling approaches; selected examples are provided in this article. Their progress is mirrored by granted patents, most of which have a very limited scope and narrowly cover certain technologies. Global introduction of waste utilization techniques to the polymer market is currently not fully developed, but has an enormous potential. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

NASA's Astronomy Education Program: Reaching Diverse Audiences

NASA Astrophysics Data System (ADS)

Hasan, Hashima; Smith, Denise Anne; Hertz, Paul; Meinke, Bonnie

2015-08-01

An overview will be given of the rich programs developed by NASA to inject the science from it's Astrophysics missions into STEM activities targeted to diverse audiences. For example, Astro4Girls was started as a pilot program during IYA2009. This program partners NASA astrophysics education programs with public libraries to provide NASA-themed hands-on education activities for girls and their families, and has been executed across the country. School curricula and NASA websites have been translated in Spanish; Braille books have been developed for the visually impaired; programs have been developed for the hearing impaired. Special effort has been made to reach underrepresented minorities. Audiences include students, teachers, and the general public through formal and informal education settings, social media and other outlets. NASA Astrophysics education providers include teams embedded in its space flight missions; professionals selected though peer reviewed programs; as well as the Science Mission Directorate Astrophysics Education forum. Representative examples will be presented to demonstrate the reach of NASA education programs, as well as an evaluation of the effectiveness of these programs.

Do terrestrial gastropods use olfactory cues to locate and select food actively?

PubMed

Kiss, Tibor

2017-09-01

Having been investigated for over 40 years, some aspects of the biology of terrestrial gastropod's olfactory system have been challenging and highly contentious, while others still remain unresolved. For example, a number of terrestrial gastropod species can track the odor of food, while others have no strong preferences toward food odor; rather they find it by random encounter. Here, while assessing the most recent findings and comparing them with earlier studies, the aspects of the food selection based on olfactory cues are examined critically to highlight the speculations and controversies that have arisen. We analyzed and compared the potential role of airborne odors in the feeding behavior of several terrestrial gastropod species. The available results indicate that in the foraging of most of the terrestrial gastropod species odor cues contribute substantially to food finding and selection. The results also suggest, however, that what they will actually consume largely depends on where they live and the species of gastropod that they are. Due to the voluminous literature relevant to this object, this review is not intended to be exhaustive. Instead, I selected what I consider to be the most important or critical in studies regarding the role of the olfaction in feeding of terrestrial gastropods.

Mechanisms and Evidence of Genital Coevolution: The Roles of Natural Selection, Mate Choice, and Sexual Conflict

PubMed Central

Brennan, Patricia L.R.; Prum, Richard O.

2015-01-01

Genital coevolution between the sexes is expected to be common because of the direct interaction between male and female genitalia during copulation. Here we review the diverse mechanisms of genital coevolution that include natural selection, female mate choice, male–male competition, and how their interactions generate sexual conflict that can lead to sexually antagonistic coevolution. Natural selection on genital morphology will result in size coevolution to allow for copulation to be mechanically possible, even as other features of genitalia may reflect the action of other mechanisms of selection. Genital coevolution is explicitly predicted by at least three mechanisms of genital evolution: lock and key to prevent hybridization, female choice, and sexual conflict. Although some good examples exist in support of each of these mechanisms, more data on quantitative female genital variation and studies of functional morphology during copulation are needed to understand more general patterns. A combination of different approaches is required to continue to advance our understanding of genital coevolution. Knowledge of the ecology and behavior of the studied species combined with functional morphology, quantitative morphological tools, experimental manipulation, and experimental evolution have been provided in the best-studied species, all of which are invertebrates. Therefore, attention to vertebrates in any of these areas is badly needed. PMID:26134314

Use of Social Media in the Assessment of Relative Effectiveness: Explorative Review With Examples From Oncology.

PubMed

Kalf, Rachel Rj; Makady, Amr; Ten Ham, Renske Mt; Meijboom, Kim; Goettsch, Wim G

2018-06-08

An element of health technology assessment constitutes assessing the clinical effectiveness of drugs, generally called relative effectiveness assessment. Little real-world evidence is available directly after market access, therefore randomized controlled trials are used to obtain information for relative effectiveness assessment. However, there is growing interest in using real-world data for relative effectiveness assessment. Social media may provide a source of real-world data. We assessed the extent to which social media-generated health data has provided insights for relative effectiveness assessment. An explorative literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify examples in oncology where health data were collected using social media. Scientific and grey literature published between January 2010 and June 2016 was identified by four reviewers, who independently screened studies for eligibility and extracted data. A descriptive qualitative analysis was performed. Of 1032 articles identified, eight were included: four articles identified adverse events in response to cancer treatment, three articles disseminated quality of life surveys, and one study assessed the occurrence of disease-specific symptoms. Several strengths of social media-generated health data were highlighted in the articles, such as efficient collection of patient experiences and recruiting patients with rare diseases. Conversely, limitations included validation of authenticity and presence of information and selection bias. Social media may provide a potential source of real-world data for relative effectiveness assessment, particularly on aspects such as adverse events, symptom occurrence, quality of life, and adherence behavior. This potential has not yet been fully realized and the degree of usefulness for relative effectiveness assessment should be further explored. ©Rachel R.J. Kalf, Amr Makady, Renske M.T. ten Ham, Kim Meijboom, Wim G. Goettsch, On Behalf Of IMI-GetReal Workpackage 1. Originally published in JMIR Cancer (http://cancer.jmir.org), 08.06.2018.

Dental Implant Systems

PubMed Central

Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

2010-01-01

Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

Modelling individual difference in visual categorization.

PubMed

Shen, Jianhong; Palmeri, Thomas J

Recent years has seen growing interest in understanding, characterizing, and explaining individual differences in visual cognition. We focus here on individual differences in visual categorization. Categorization is the fundamental visual ability to group different objects together as the same kind of thing. Research on visual categorization and category learning has been significantly informed by computational modeling, so our review will focus both on how formal models of visual categorization have captured individual differences and how individual difference have informed the development of formal models. We first examine the potential sources of individual differences in leading models of visual categorization, providing a brief review of a range of different models. We then describe several examples of how computational models have captured individual differences in visual categorization. This review also provides a bit of an historical perspective, starting with models that predicted no individual differences, to those that captured group differences, to those that predict true individual differences, and to more recent hierarchical approaches that can simultaneously capture both group and individual differences in visual categorization. Via this selective review, we see how considerations of individual differences can lead to important theoretical insights into how people visually categorize objects in the world around them. We also consider new directions for work examining individual differences in visual categorization.

Modelling individual difference in visual categorization

PubMed Central

Shen, Jianhong; Palmeri, Thomas J.

2016-01-01

Recent years has seen growing interest in understanding, characterizing, and explaining individual differences in visual cognition. We focus here on individual differences in visual categorization. Categorization is the fundamental visual ability to group different objects together as the same kind of thing. Research on visual categorization and category learning has been significantly informed by computational modeling, so our review will focus both on how formal models of visual categorization have captured individual differences and how individual difference have informed the development of formal models. We first examine the potential sources of individual differences in leading models of visual categorization, providing a brief review of a range of different models. We then describe several examples of how computational models have captured individual differences in visual categorization. This review also provides a bit of an historical perspective, starting with models that predicted no individual differences, to those that captured group differences, to those that predict true individual differences, and to more recent hierarchical approaches that can simultaneously capture both group and individual differences in visual categorization. Via this selective review, we see how considerations of individual differences can lead to important theoretical insights into how people visually categorize objects in the world around them. We also consider new directions for work examining individual differences in visual categorization. PMID:28154496

Association between Upper Extremity Musculoskeletal Disorders and Psychosocial Factors at Work: A Review on the Job DCS Model's Perspective.

PubMed

Park, Jung-Keun; Jang, Seung-Hee

2010-09-01

Over years it has been increasingly concerned with how upper extremity musculoskeletal disorders (UEMSDs) are attributed to psychosocial job stressors. A review study was conducted to examine associations between UEMSDs and psychosocial work factors, and to recommend what to consider for the associations. For studies in which the job demand-control-support (DCS) model or its variables were specifically employed, published papers were selected and reviewed. A number of studies have reported relationships between UEMSDs symptoms and psychosocial exposure variables. For example, the findings are: higher numbness in the upper extremity was significantly attributed to by less decision latitude at work; work demands were significantly associated with neck and shoulder symptoms while control over time was associated with neck symptoms; and the combination of high psychosocial demands and low decision latitude was a significant predictor for shoulder and neck pain in a female working population. Sources of bias, such as interaction or study design, were discussed. UEMSDs were shown to be associated with psychosocial work factors in various studies where the job DCS model was addressed. Nonetheless, this review suggests that further studies should be conducted to much more clarify the association between UEMSDs and psychosocial factors.

Quantifying selection in evolving populations using time-resolved genetic data

NASA Astrophysics Data System (ADS)

Illingworth, Christopher J. R.; Mustonen, Ville

2013-01-01

Methods which uncover the molecular basis of the adaptive evolution of a population address some important biological questions. For example, the problem of identifying genetic variants which underlie drug resistance, a question of importance for the treatment of pathogens, and of cancer, can be understood as a matter of inferring selection. One difficulty in the inference of variants under positive selection is the potential complexity of the underlying evolutionary dynamics, which may involve an interplay between several contributing processes, including mutation, recombination and genetic drift. A source of progress may be found in modern sequencing technologies, which confer an increasing ability to gather information about evolving populations, granting a window into these complex processes. One particularly interesting development is the ability to follow evolution as it happens, by whole-genome sequencing of an evolving population at multiple time points. We here discuss how to use time-resolved sequence data to draw inferences about the evolutionary dynamics of a population under study. We begin by reviewing our earlier analysis of a yeast selection experiment, in which we used a deterministic evolutionary framework to identify alleles under selection for heat tolerance, and to quantify the selection acting upon them. Considering further the use of advanced intercross lines to measure selection, we here extend this framework to cover scenarios of simultaneous recombination and selection, and of two driver alleles with multiple linked neutral, or passenger, alleles, where the driver pair evolves under an epistatic fitness landscape. We conclude by discussing the limitations of the approach presented and outlining future challenges for such methodologies.

Medicus Deus: a review of factors affecting hospital library services to patients between 1790–1950

PubMed Central

Perryman, Carol

2006-01-01

Question: What are some of the historical societal, medical, and public health trends leading to today's provision of hospital library services to patients? Data Sources: Literature from the archives of the Bulletin of the Medical Library Association and other library sources, medical journals, primary historical documents, and texts from the history of medicine form the core of this review. Study Selection: The period of review extends from about 1790 through 1950 and focuses solely on trends in the United States. Of primary concern are explicitly documented examples that appear to illustrate the patient-physician relationship and those between librarians and their patient-patrons during the earliest years of the profession's development. Data Extraction: An historical timeline was created to allow the identification of major trends that may have affected library services. Multiple literature searches were conducted using library, medical, and health anthropology resources. When possible, primary sources were preferred over reviews. Main Results: Juxtapositioning historical events allows the reader to obtain an overview of the roots of consumer health services in medical libraries and to consider their potential legacy in today's health care libraries. Conclusion: This review article highlights early developments in hospital library service to patients. Further research is needed to verify a preliminary conclusion that in some medical library settings, services to the general public are shaped by the broader health care environment as it has evolved. PMID:16888658

Do Current Recommendations for Upper Instrumented Vertebra Predict Shoulder Imbalance? An Attempted Validation of Level Selection for Adolescent Idiopathic Scoliosis.

PubMed

Bjerke, Benjamin T; Cheung, Zoe B; Shifflett, Grant D; Iyer, Sravisht; Derman, Peter B; Cunningham, Matthew E

2015-10-01

Shoulder balance for adolescent idiopathic scoliosis (AIS) patients is associated with patient satisfaction and self-image. However, few validated systems exist for selecting the upper instrumented vertebra (UIV) post-surgical shoulder balance. The purpose is to examine the existing UIV selection criteria and correlate with post-surgical shoulder balance in AIS patients. Patients who underwent spinal fusion at age 10-18 years for AIS over a 6-year period were reviewed. All patients with a minimum of 1-year radiographic follow-up were included. Imbalance was determined to be radiographic shoulder height |RSH| ≥ 15 mm at latest follow-up. Three UIV selection methods were considered: Lenke, Ilharreborde, and Trobisch. A recommended UIV was determined using each method from pre-surgical radiographs. The recommended UIV for each method was compared to the actual UIV instrumented for all three methods; concordance between these levels was defined as "Correct" UIV selection, and discordance was defined as "Incorrect" selection. One hundred seventy-one patients were included with 2.3 ± 1.1 year follow-up. For all methods, "Correct" UIV selection resulted in more shoulder imbalance than "Incorrect" UIV selection. Overall shoulder imbalance incidence was improved from 31.0% (53/171) to 15.2% (26/171). New shoulder imbalance incidence for patients with previously level shoulders was 8.8%. We could not identify a set of UIV selection criteria that accurately predicted post-surgical shoulder balance. Further validated measures are needed in this area. The complexity of proximal thoracic curve correction is underscored in a case example, where shoulder imbalance occurred despite "Correct" UIV selection by all methods.

Molecular plant breeding: methodology and achievements.

PubMed

Varshney, Rajeev K; Hoisington, Dave A; Nayak, Spurthi N; Graner, Andreas

2009-01-01

The progress made in DNA marker technology has been remarkable and exciting in recent years. DNA markers have proved valuable tools in various analyses in plant breeding, for example, early generation selection, enrichment of complex F(1)s, choice of donor parent in backcrossing, recovery of recurrent parent genotype in backcrossing, linkage block analysis and selection. Other main areas of applications of molecular markers in plant breeding include germplasm characterization/fingerprinting, determining seed purity, systematic sampling of germplasm, and phylogenetic analysis. Molecular markers, thus, have proved powerful tools in replacing the bioassays and there are now many examples available to show the efficacy of such markers. We have illustrated some basic concepts and methodology of applying molecular markers for enhancing the selection efficiency in plant breeding. Some successful examples of product developments of molecular breeding have also been presented.

Approaches to sampling and case selection in qualitative research: examples in the geography of health.

PubMed

Curtis, S; Gesler, W; Smith, G; Washburn, S

2000-04-01

This paper focuses on the question of sampling (or selection of cases) in qualitative research. Although the literature includes some very useful discussions of qualitative sampling strategies, the question of sampling often seems to receive less attention in methodological discussion than questions of how data is collected or is analysed. Decisions about sampling are likely to be important in many qualitative studies (although it may not be an issue in some research). There are varying accounts of the principles applicable to sampling or case selection. Those who espouse 'theoretical sampling', based on a 'grounded theory' approach, are in some ways opposed to those who promote forms of 'purposive sampling' suitable for research informed by an existing body of social theory. Diversity also results from the many different methods for drawing purposive samples which are applicable to qualitative research. We explore the value of a framework suggested by Miles and Huberman [Miles, M., Huberman,, A., 1994. Qualitative Data Analysis, Sage, London.], to evaluate the sampling strategies employed in three examples of research by the authors. Our examples comprise three studies which respectively involve selection of: 'healing places'; rural places which incorporated national anti-malarial policies; young male interviewees, identified as either chronically ill or disabled. The examples are used to show how in these three studies the (sometimes conflicting) requirements of the different criteria were resolved, as well as the potential and constraints placed on the research by the selection decisions which were made. We also consider how far the criteria Miles and Huberman suggest seem helpful for planning 'sample' selection in qualitative research.

Optimized approaches for quantification of drug transporters in tissues and cells by MRM proteomics.

PubMed

Prasad, Bhagwat; Unadkat, Jashvant D

2014-07-01

Drug transporter expression in tissues (in vivo) usually differs from that in cell lines used to measure transporter activity (in vitro). Therefore, quantification of transporter expression in tissues and cell lines is important to develop scaling factor for in vitro to in vivo extrapolation (IVIVE) of transporter-mediated drug disposition. Since traditional immunoquantification methods are semiquantitative, targeted proteomics is now emerging as a superior method to quantify proteins, including membrane transporters. This superiority is derived from the selectivity, precision, accuracy, and speed of analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode. Moreover, LC-MS/MS proteomics has broader applicability because it does not require selective antibodies for individual proteins. There are a number of recent research and review papers that discuss the use of LC-MS/MS for transporter quantification. Here, we have compiled from the literature various elements of MRM proteomics to provide a comprehensive systematic strategy to quantify drug transporters. This review emphasizes practical aspects and challenges in surrogate peptide selection, peptide qualification, peptide synthesis and characterization, membrane protein isolation, protein digestion, sample preparation, LC-MS/MS parameter optimization, method validation, and sample analysis. In particular, bioinformatic tools used in method development and sample analysis are discussed in detail. Various pre-analytical and analytical sources of variability that should be considered during transporter quantification are highlighted. All these steps are illustrated using P-glycoprotein (P-gp) as a case example. Greater use of quantitative transporter proteomics will lead to a better understanding of the role of drug transporters in drug disposition.

Novel Metals and Metal Complexes as Platforms for Cancer Therapy

PubMed Central

Frezza, Michael; Hindo, Sarmad; Chen, Di; Davenport, Andrew; Schmitt, Sara; Tomco, Dajena; Dou, Q. Ping

2013-01-01

Metals are essential cellular components selected by nature to function in several indispensable biochemical processes for living organisms. Metals are endowed with unique characteristics that include redox activity, variable coordination modes, and reactivity towards organic substrates. Due to their reactivity, metals are tightly regulated under normal conditions and aberrant metal ion concentrations are associated with various pathological disorders, including cancer. For these reasons, coordination complexes, either as drugs or prodrugs, become very attractive probes as potential anticancer agents. The use of metals and their salts for medicinal purposes, from iatrochemistry to modern day, has been present throughout human history. The discovery of cisplatin, cis-[PtII(NH3)2Cl2], was a defining moment which triggered the interest in platinum(II)- and other metal-containing complexes as potential novel anticancer drugs. Other interests in this field address concerns for uptake, toxicity, and resistance to metallodrugs. This review article highlights selected metals that have gained considerable interest in both the development and the treatment of cancer. For example, copper is enriched in various human cancer tissues and is a co-factor essential for tumor angiogenesis processes. However the use of copper-binding ligands to target tumor copper could provide a novel strategy for cancer selective treatment. The use of nonessential metals as probes to target molecular pathways as anticancer agents is also emphasized. Finally, based on the interface between molecular biology and bioinorganic chemistry the design of coordination complexes for cancer treatment is reviewed and design strategies and mechanisms of action are discussed. PMID:20337575

Beyond directed evolution - semi-rational protein engineering and design

PubMed Central

Lutz, Stefan

2010-01-01

Over the last two decades, directed evolution has transformed the field of protein engineering. The advances in understanding protein structure and function, in no insignificant part a result of directed evolution studies, are increasingly empowering scientists and engineers to device more effective methods for manipulating and tailoring biocatalysts. Abandoning large combinatorial libraries, the focus has shifted to small, functionally-rich libraries and rational design. A critical component to the success of these emerging engineering strategies are computational tools for the evaluation of protein sequence datasets and the analysis of conformational variations of amino acids in proteins. Highlighting the opportunities and limitations of such approaches, this review focuses on recent engineering and design examples that require screening or selection of small libraries. PMID:20869867

Aptamer-incorporated hydrogels for visual detection, controlled drug release, and targeted cancer therapy

PubMed Central

Liu, Jun; Kang, Huaizhi; Donovan, Michael; Zhu, Zhi

2017-01-01

Hydrogels are water-retainable materials, made from cross-linked polymers, that can be tailored to applications in bioanalysis and biomedicine. As technology advances, an increasing number of molecules have been used as the components of hydrogel systems. However, the shortcomings of these systems have prompted researchers to find new materials that can be incorporated into them. Among all of these emerging materials, aptamers have recently attracted substantial attention because of their unique properties, for example biocompatibility, selective binding, and molecular recognition, all of which make them promising candidates for target-responsive hydrogel engineering. In this work, we will review how aptamers have been incorporated into hydrogel systems to enable colorimetric detection, controlled drug release, and targeted cancer therapy. PMID:22052153

Microorganisms in inorganic chemical analysis.

PubMed

Godlewska-Zyłkiewicz, Beata

2006-01-01

There are innumerable strains of microbes (bacteria, yeast and fungi) that degrade or transform chemicals and compounds into simpler, safer or less toxic substances. These bioprocesses have been used for centuries in the treatment of municipal wastes, in wine, cheese and bread making, and in bioleaching and metal recovery processes. Recent literature shows that microorganisms can be also used as effective sorbents for solid phase extraction procedures. This review reveals that fundamental nonanalytical studies on the parameters and conditions of biosorption processes and on metal-biomass interactions often result in efficient analytical procedures and biotechnological applications. Some selected examples illustrate the latest developments in the biosorption of metals by microbial biomass, which have opened the door to the application of microorganisms to analyte preconcentration, matrix separation and speciation analysis.

Amides in Nature and Biocatalysis.

PubMed

Pitzer, Julia; Steiner, Kerstin

2016-10-10

Amides are widespread in biologically active compounds with a broad range of applications in biotechnology, agriculture and medicine. Therefore, as alternative to chemical synthesis the biocatalytic amide synthesis is a very interesting field of research. As usual, Nature can serve as guide in the quest for novel biocatalysts. Several mechanisms for carboxylate activation involving mainly acyl-adenylate, acyl-phosphate or acyl-enzyme intermediates have been discovered, but also completely different pathways to amides are found. In addition to ribosomes, selected enzymes of almost all main enzyme classes are able to synthesize amides. In this review we give an overview about amide synthesis in Nature, as well as biotechnological applications of these enzymes. Moreover, several examples of biocatalytic amide synthesis are given. Copyright © 2016 Elsevier B.V. All rights reserved.

Bite angle effects of diphosphines in C-C and C-X bond forming cross coupling reactions.

PubMed

Birkholz, Mandy-Nicole; Freixa, Zoraida; van Leeuwen, Piet W N M

2009-04-01

Catalytic reactions of C-C and C-X bond formation are discussed in this critical review with particular emphasis on cross coupling reactions catalyzed by palladium and wide bite angle bidentate diphosphine ligands. Especially those studies have been collected that allow comparison of the ligand bite angles for the selected ligands: dppp, BINAP, dppf, DPEphos and Xantphos. Similarities with hydrocyanation and CO/ethene/MeOH reactions have been highlighted, while rhodium hydroformylation has been mentioned as a contrasting example, in which predictability is high and steric and electronic effects follow smooth trends. In palladium catalysis wide bite angles and bulkiness of the ligands facilitate generally the reductive elimination thus giving more efficient cross coupling catalysis (174 references).

Prodrug strategy for cancer cell-specific targeting: A recent overview.

PubMed

Zhang, Xian; Li, Xiang; You, Qidong; Zhang, Xiaojin

2017-10-20

The increasing development of targeted cancer therapy provides extensive possibilities in clinical trials, and numerous strategies have been explored. The prodrug is one of the most promising strategies in targeted cancer therapy to improve the selectivity and efficacy of cytotoxic compounds. Compared with normal tissues, cancer cells are characterized by unique aberrant markers, thus inactive prodrugs targeting these markers are excellent therapeutics to release active drugs, killing cancer cells without damaging normal tissues. In this review, we explore an integrated view of potential prodrugs applied in targeted cancer therapy based on aberrant cancer specific markers and some examples are provided for inspiring new ideas of prodrug strategy for cancer cell-specific targeting. Copyright © 2017. Published by Elsevier Masson SAS.

New Approaches to Radiation Protection

PubMed Central

Rosen, Eliot M.; Day, Regina; Singh, Vijay K.

2015-01-01

Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development. PMID:25653923

Convective dynamics - Panel report

NASA Technical Reports Server (NTRS)

Carbone, Richard; Foote, G. Brant; Moncrieff, Mitch; Gal-Chen, Tzvi; Cotton, William; Heymsfield, Gerald

1990-01-01

Aspects of highly organized forms of deep convection at midlatitudes are reviewed. Past emphasis in field work and cloud modeling has been directed toward severe weather as evidenced by research on tornadoes, hail, and strong surface winds. A number of specific issues concerning future thrusts, tactics, and techniques in convective dynamics are presented. These subjects include; convective modes and parameterization, global structure and scale interaction, convective energetics, transport studies, anvils and scale interaction, and scale selection. Also discussed are analysis workshops, four-dimensional data assimilation, matching models with observations, network Doppler analyses, mesoscale variability, and high-resolution/high-performance Doppler. It is also noted, that, classical surface measurements and soundings, flight-level research aircraft data, passive satellite data, and traditional photogrammetric studies are examples of datasets that require assimilation and integration.