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Sample records for double edged sword

  1. Neutrophil-Epithelial Interactions: A Double-Edged Sword.

    PubMed

    Parkos, Charles A

    2016-06-01

    In recent years, it has become clear that innate immune cells termed neutrophils act as double-edged swords by playing essential roles in clearing infection but also causing tissue damage, yet being critical for wound healing. Neutrophil recruitment to sites of injured tissue or infection has been well studied, and many of the molecular events that regulate passage of leukocytes out of the microcirculation are now understood. However, after exiting the circulation, the molecular details that regulate neutrophil passage to end targets, such mucosal surfaces, are just beginning to be appreciated. Given that migration of neutrophils across mucosal epithelia is associated with disease symptoms and disruption of critical barrier function in disorders such as inflammatory bowel disease, there has been long-standing interest in understanding the molecular basis and functional consequences of neutrophil-epithelial interactions. It is a great honor that my work was recognized by the Rous-Whipple Award this past year, giving me the opportunity to summarize what we have learned during the past few decades about leukocyte interactions with epithelial cells. PMID:27083514

  2. Targeting DUSPs in glioblastomas - wielding a double-edged sword?

    PubMed

    Prabhakar, Sheila; Asuthkar, Swapna; Lee, William; Chigurupati, Srinivasulu; Zakharian, Eleonora; Tsung, Andrew J; Velpula, Kiran Kumar

    2014-02-01

    Several dual-specificity phosphatases (DUSPs) that play key roles in the direct or indirect inactivation of different MAP kinases (MAPKs) have been implicated in human cancers over the past decade. This has led to a growing interest in identifying DUSPs and their specific inhibitors for further testing and validation as therapeutic targets in human cancers. However, the lack of understanding of the complex regulatory mechanisms and cross-talks between MAPK signaling pathways, combined with the fact that DUSPs can act as a double-edged sword in cancer progression, calls for a more careful and thorough investigation. Among the various types of brain cancer, glioblastoma multiforme (GBM) is notorious for its aggressiveness and resistance to current treatment modalities. This has led to the search for new molecular targets, particularly those involving various signaling pathways. DUSPs appear to be a promising target, but much more information on DUSP targets and their effects on GBM is needed before potential therapies can be developed, tested, and validated. This review identifies and summarize the specific roles of DUSP1, DUSP4, DUSP6 and DUSP26 that have been implicated in GBM. PMID:24155099

  3. Education Is a Double-Edged Sword: Thoughts on Indian and Non-Indian Education.

    ERIC Educational Resources Information Center

    Simonelli, Richard

    2001-01-01

    For Native people and others who feel the dangers of the dominant materialistic world view, education is a double-edged sword. Mainstream education and the skills it teaches are necessary to survive in contemporary life, but mainstream values may be destructive to humanity and must be balanced by learning activities that promote heart,…

  4. Exogenous antioxidants—Double-edged swords in cellular redox state

    PubMed Central

    Bohn, Torsten

    2010-01-01

    The balance between oxidation and antioxidation is believed to be critical in maintaining healthy biological systems. Under physiological conditions, the human antioxidative defense system including e.g., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH) and others, allows the elimination of excess reactive oxygen species (ROS) including, among others superoxide anions (O2.-), hydroxyl radicals (OH.), alkoxyl radicals (RO.) and peroxyradicals (ROO.). However, our endogenous antioxidant defense systems are incomplete without exogenous originating reducing compounds such as vitamin C, vitamin E, carotenoids and polyphenols, playing an essential role in many antioxidant mechanisms in living organisms. Therefore, there is continuous demand for exogenous antioxidants in order to prevent oxidative stress, representing a disequilibrium redox state in favor of oxidation. However, high doses of isolated compounds may be toxic, owing to prooxidative effects at high concentrations or their potential to react with beneficial concentrations of ROS normally present at physiological conditions that are required for optimal cellular functioning. This review aims to examine the double-edged effects of dietary originating antioxidants with a focus on the most abundant compounds, especially polyphenols, vitamin C, vitamin E and carotenoids. Different approaches to enrich our body with exogenous antioxidants such as via synthetic antioxidants, diets rich in fruits and vegetables and taking supplements will be reviewed and experimental and epidemiological evidences discussed, highlighting that antioxidants at physiological doses are generally safe, exhibiting interesting health beneficial effects. PMID:20972369

  5. Swords with Blunt Edges

    ERIC Educational Resources Information Center

    Popham, W. James

    2004-01-01

    Many U.S. educators now wonder whether they're teachers or targets. This mentality stems from the specter of their school being sanctioned for failing the state accountability tests mandated under No Child Left Behind (NCLB). According to this author, most of those tests are like blunt-edged swords: They function badly in two directions. While…

  6. DNA damage tolerance: a double-edged sword guarding the genome

    PubMed Central

    Ghosal, Gargi; Chen, Junjie

    2013-01-01

    Preservation of genome integrity is an essential process for cell homeostasis. During the course of life of a single cell, the genome is constantly damaged by endogenous and exogenous agents. To ensure genome stability, cells use a global signaling network, namely the DNA damage response (DDR) to sense and repair DNA damage. DDR senses different types of DNA damage and coordinates a response that includes activation of transcription, cell cycle control, DNA repair pathways, apoptosis, senescence, and cell death. Despite several repair mechanisms that repair different types of DNA lesions, it is likely that the replication machinery would still encounter lesions that are mis-repaired or not repaired. Replication of damaged genome would result in high frequency of fork collapse and genome instability. In this scenario, the cells employ the DNA damage tolerance (DDT) pathway that recruits a specialized low fidelity translesion synthesis (TLS) polymerase to bypass the lesions for repair at a later time point. Thus, DDT is not a repair pathway per se, but provides a mechanism to tolerate DNA lesions during replication thereby increasing survival and preventing genome instability. Paradoxically, DDT process is also associated with increased mutagenesis, which can in turn drive the cell to cancer development. Thus, DDT process functions as a double-edged sword guarding the genome. In this review, we will discuss the replication stress induced DNA damage-signaling cascade, the stabilization and rescue of stalled replication forks by the DDT pathway and the effect of the DDT pathway on cancer. PMID:24058901

  7. Grb2, a Double-Edged Sword of Receptor Tyrosine Kinase Signaling

    PubMed Central

    Belov, Artur A.; Mohammadi, Moosa

    2013-01-01

    Receptor tyrosine kinases (RTKs) exhibit basal tyrosine phosphorylation and activity in the absence of ligand stimulation, which has been attributed to the “leaky” nature of tyrosine kinase autoinhibition and stochastic collisions of receptors in the membrane bilayer. This basal phosphorylation does not produce a signal of sufficient amplitude and intensity to manifest in a biological response and hence is considered to be a passive, futile process that does not have any biological function. This paradigm has now been challenged by a study showing that the basal phosphorylation of RTKs is a physiologically relevant process that is actively inhibited by the intracellular adaptor protein growth factor receptor-bound 2 (Grb2) and serves to “prime” receptors for a rapid response to ligand stimulation. Grb2 is conventionally known for playing positive roles in RTK signaling. The discovery of a negative regulatory role for Grb2 reveals that this adaptor acts as a double-edged sword in the regulation of RTK signaling. PMID:23131845

  8. Peer pressure is a double-edged sword in vaccination dynamics

    NASA Astrophysics Data System (ADS)

    Wu, Zhi-Xi; Zhang, Hai-Feng

    2013-10-01

    Whether or not to change behavior depends not only on the personal success of each individual, but also on the success and/or behavior of others. Using this as motivation, we incorporate the impact of peer pressure into a susceptible-vaccinated-infected-recovered (SVIR) epidemiological model, where the propensity to adopt a particular vaccination strategy depends both on individual success as well as on the strategies of neighbors. We show that plugging into the peer pressure is a double-edged sword, which, on the one hand, strongly promotes vaccination when its cost is below a critical value, but, on the other hand, it can also strongly impede it if the critical value is exceeded. We explain this by revealing a facilitated cluster formation process that is induced by the peer pressure. Due to this, the vaccinated individuals are inclined to cluster together and therefore become unable to efficiently inhibit the spread of the infectious disease if the vaccination is costly. If vaccination is cheap, however, they reinforce each other in using it. Our results are robust to variations of the SVIR dynamics on different population structures.

  9. Economic empowerment and AIDS-related stigma in rural Kenya: a double-edged sword?

    PubMed

    Gnauck, Katherine; Ruiz, Jamie; Kellett, Nicole; Sussman, Andrew; Sullivan, Mary Ann; Montoya, Maria; Levin, Nick; Tomedi, Angelo; Mwanthi, Mutuku A

    2013-01-01

    Economic empowerment, HIV risk and AIDS-related stigma appear intricately intertwined for women in Kenya. Their interaction must be understood in order to implement effective economic interventions that also decrease HIV risk and stigma. We conducted a qualitative study amongst women in a rural Kamba-speaking community of southeastern Kenya to pursue whether engagement in an economic empowerment initiative (a basket weaving cooperative) influences women's perspectives and experiences with HIV risk and AIDS-related stigma. We conducted seven women's focus groups: participants in the local basket-weaving cooperative comprised four focus groups and non-participants comprised the remaining three groups. The HIV status of the women was not known. Three dominant themes emerged from the focus groups: empowerment, pervasive vulnerability and unanticipated social paradoxes. Contradictions found in these themes suggest that economic empowerment can become a double-edged sword. Economic empowerment enhanced perceived individual, domestic and social community status. However, this enhancement was not protective of domestic violence and perceived HIV risk. Social perceptions may have paradoxically contributed barriers to HIV testing and treatment putting women at greater HIV risk. In conclusion, economic empowerment initiatives for women in developing countries in the context of the HIV epidemic should be coupled with peer mediated support and HIV-risk education. PMID:23668536

  10. Education and income: double-edged swords in the epidemiologic transition of cardiovascular disease.

    PubMed

    Pearson, Thomas A

    2003-01-01

    The 2002 World Health Report warns that the allies of poverty and ignorance are joining forces with the new formidable enemies of health. This describes the epidemiologic transition of burden of disease from infectious and parasitic diseases to that of noncommunicable diseases. All parts of the world, with the possible exception of sub-Saharan Africa, have well-established epidemics of coronary heart disease and stroke. Hypertension contributes significantly to mortality everywhere and is a leading global problem. Education and wealth have strong influences on the epidemiologic transition and might serve as a double-edged sword of benefit and risk. While improved education and enhanced resources are necessary to reduce infectious, parasitic, and perinatal diseases, these factors are also associated with adoption of deleterious health behaviors, which lead to the atherosclerotic diseases. The diffusion of innovation theory describes the early adoption of unhealthy lifestyles in the educated and wealthy, who soon recognize the costs to their community and modify these lifestyles. The uneducated poor may adopt these unhealthy lifestyles later, but, once that occurs, are left with higher risk and burden of cardiovascular disease. One possible reason for this is that discretionary income and the desire for modern conveniences quickly attract unhealthy products (tobacco, high fat/high salt foods) and unhealthy behaviors (sedentary entertainment transportation without physical exertion). The commercial interests of these products have been efficient and effective in delivering their messages to developing societies. Heart health organizations must be more aggressive in their assessment of needs for programs, education of people over a broad range of education levels, assurance of access to heart health services, alteration of the environment to facilitate heart health, and the development of policies and laws to limit deleterious products and behaviors. These late

  11. Heat shock protein 90 inhibition: A potential double- or triple-edged sword in the treatment of mucous membrane pemphigoid.

    PubMed

    Kasperkiewicz, Michael; Płatkowska, Anna; Zalewska, Anna; Zillikens, Detlef

    2015-10-01

    Mucous membrane pemphigoid (MMP) is a subtype of autoimmune subepidermal blistering diseases characterized by autoantibodies to structural components of the hemidesmosome primarily affecting mucous membranes. Inflammation-related progressive scarring can lead to serious complications, including blindness, and the disease may be associated with malignancy. Conventional immunosuppressive treatment is often insufficiently effective and limited due to side effects, warranting new therapeutic options ideally targeting both inflammation and extensively recalcitrant cicatrization. Heat shock protein 90 (Hsp90) is a cell stress-inducible chaperone required for the function of a large number of client proteins, and its pharmacological inhibition has proven to be effective and relatively safe in patients with cancer. Recent observations also suggest a promising role of Hsp90 as drug target in preclinical in vivo murine models of autoimmune diseases such as subepidermal bullous and fibrotic autoimmune disorders comprising epidermolysis bullosa acquisita and systemic sclerosis, respectively, which exhibit some pathophysiological features reminiscent of MMP. This article thus hypothesizes that Hsp90 blockade could represent a double-edged sword in MMP treatment by targeting pathogenic factors of inflammatory blister and fibrosis formation. Moreover, Hsp90 inhibitors could even be proclaimed as a triple-edged sword in case of an underlying malignancy. Future studies investigating the role of Hsp90 in MMP are needed to clarify whether Hsp90 inhibition could become a novel treatment approach for patients with this potentially devastating disease. PMID:26152650

  12. The double-edged sword of grandiose narcissism: implications for successful and unsuccessful leadership among U.S. Presidents.

    PubMed

    Watts, Ashley L; Lilienfeld, Scott O; Smith, Sarah Francis; Miller, Joshua D; Campbell, W Keith; Waldman, Irwin D; Rubenzer, Steven J; Faschingbauer, Thomas J

    2013-12-01

    Recent research and theorizing suggest that narcissism may predict both positive and negative leadership behaviors. We tested this hypothesis with data on the 42 U.S. presidents up to and including George W. Bush, using (a) expert-derived narcissism estimates, (b) independent historical surveys of presidential performance, and (c) largely or entirely objective indicators of presidential performance. Grandiose, but not vulnerable, narcissism was associated with superior overall greatness in an aggregate poll; it was also positively associated with public persuasiveness, crisis management, agenda setting, and allied behaviors, and with several objective indicators of performance, such as winning the popular vote and initiating legislation. Nevertheless, grandiose narcissism was also associated with several negative outcomes, including congressional impeachment resolutions and unethical behaviors. We found that presidents exhibit elevated levels of grandiose narcissism compared with the general population, and that presidents' grandiose narcissism has been rising over time. Our findings suggest that grandiose narcissism may be a double-edged sword in the leadership domain. PMID:24104503

  13. Immune checkpoint blockade in cancer treatment: a double-edged sword cross-targeting the host as an "innocent bystander".

    PubMed

    Gelao, Lucia; Criscitiello, Carmen; Esposito, Angela; Goldhirsch, Aron; Curigliano, Giuseppe

    2014-03-01

    Targeted immune checkpoint blockade augments anti-tumor immunity and induces durable responses in patients with melanoma and other solid tumors. It also induces specific "immune-related adverse events" (irAEs). IrAEs mainly include gastrointestinal, dermatological, hepatic and endocrinological toxicities. Off-target effects that arise appear to account for much of the toxicity of the immune checkpoint blockade. These unique "innocent bystander" effects are likely a direct result of breaking immune tolerance upon immune check point blockade and require specific treatment guidelines that include symptomatic therapies or systemic corticosteroids. What do we need going forward to limit immune checkpoint blockade-induced toxicity? Most importantly, we need a better understanding of the roles played by these agents in normal tissues, so that we can begin to predict potentially problematic side effects on the basis of their selectivity profile. Second, we need to focus on the predictive factors of the response and toxicity of the host rather than serially focusing on individual agents. Third, rigorous biomarker-driven clinical trials are needed to further elucidate the mechanisms of both the benefit and toxicity. We will summarize the double-edged sword effect of immunotherapeutics in cancer treatment. PMID:24594636

  14. Facebook and its effects on users' empathic social skills and life satisfaction: a double-edged sword effect.

    PubMed

    Chan, Terri H

    2014-05-01

    This study examines how Facebook usage affects individual's empathic social skills and life satisfaction. Following the self-presentational theory, the study explores a key component of the Internet paradox-whether Facebook suppresses or enhances users' interpersonal competence (specifically empathic social skills), given their respective personality makeup. Going further, the study assesses these events' subsequent impacts on users' psychological well-being. Analogous to a double-edged sword, Facebook activities are hypothesized to suppress the positive effect of a user's extraversion orientation on empathic social skills but lessen the negative effect of neuroticism on these skills. The study examines a sample of college-aged Facebook users (n=515), who responded to a large-scale online survey. The findings from a structural equation modeling analysis indicate that while empathic social skills are positively associated with life satisfaction, Facebook activities mainly exert suppression effects. Only upon low usage can Facebook activities lessen the negative effect of neuroticism on empathic social skills, suggesting that Facebook may appear as a less threatening platform for social interactions among neurotics. Yet, results in general suggest that undesirable effects may occur at high levels of Facebook usage whereby both extroverted and neurotic users displace real world social ties to online ones. The findings point to the complex ways in which social media usage may impact the livelihood of users. PMID:24606026

  15. Galectins: Double-edged Swords in the Cross-roads of Pregnancy Complications and Female Reproductive Tract Inflammation and Neoplasia

    PubMed Central

    Than, Nandor Gabor; Romero, Roberto; Balogh, Andrea; Karpati, Eva; Mastrolia, Salvatore Andrea; Staretz-Chacham, Orna; Hahn, Sinuhe; Erez, Offer; Papp, Zoltan; Kim, Chong Jai

    2015-01-01

    Galectins are an evolutionarily ancient and widely expressed family of lectins that have unique glycan-binding characteristics. They are pleiotropic regulators of key biological processes, such as cell growth, proliferation, differentiation, apoptosis, signal transduction, and pre-mRNA splicing, as well as homo- and heterotypic cell-cell and cell-extracellular matrix interactions. Galectins are also pivotal in immune responses since they regulate host-pathogen interactions, innate and adaptive immune responses, acute and chronic inflammation, and immune tolerance. Some galectins are also central to the regulation of angiogenesis, cell migration and invasion. Expression and functional data provide convincing evidence that, due to these functions, galectins play key roles in shared and unique pathways of normal embryonic and placental development as well as oncodevelopmental processes in tumorigenesis. Therefore, galectins may sometimes act as double-edged swords since they have beneficial but also harmful effects for the organism. Recent advances facilitate the use of galectins as biomarkers in obstetrical syndromes and in various malignancies, and their therapeutic applications are also under investigation. This review provides a general overview of galectins and a focused review of this lectin subfamily in the context of inflammation, infection and tumors of the female reproductive tract as well as in normal pregnancies and those complicated by the great obstetrical syndromes. PMID:26018511

  16. NR2B subunit in the prefrontal cortex: A double-edged sword for working memory function and psychiatric disorders.

    PubMed

    Monaco, Sarah A; Gulchina, Yelena; Gao, Wen-Jun

    2015-09-01

    The prefrontal cortex (PFC) is a brain region featured with working memory function. The exact mechanism of how working memory operates within the PFC circuitry is unknown, but persistent neuronal firing recorded from prefrontal neurons during a working memory task is proposed to be the neural correlate of this mnemonic encoding. The PFC appears to be specialized for sustaining persistent firing, with N-methyl-D-aspartate (NMDA) receptors, especially slow-decay NR2B subunits, playing an essential role in the maintenance of sustained activity and normal working memory function. However, the NR2B subunit serves as a double-edged sword for PFC function. Because of its slow kinetics, NR2B endows the PFC with not only "neural psychic" properties, but also susceptibilities for neuroexcitotoxicity and psychiatric disorders. This review aims to clarify the interplay among working memory, the PFC, and NMDA receptors; demonstrate the importance of NR2B in the maintenance of persistent activity; understand the risks and vulnerabilities of how NR2B is related to the development of neuropsychiatric disorders; identify gaps that currently exist in our understanding of these processes; and provide insights regarding future directions that may clarify these issues. We conclude that the PFC is a specialized brain region with distinct delayed maturation, unique neuronal circuitry, and characteristic NMDA receptor function. The unique properties and development of NMDA receptors, especially enrichment of NR2B subunits, endow the PFC with not only the capability to generate sustained activity for working memory, but also serves as a major vulnerability to environmental insults and risk factors for psychiatric disorders. PMID:26143512

  17. Comparative Phylogeography Highlights the Double-Edged Sword of Climate Change Faced by Arctic- and Alpine-Adapted Mammals

    PubMed Central

    Lanier, Hayley C.; Gunderson, Aren M.; Weksler, Marcelo; Fedorov, Vadim B.; Olson, Link E.

    2015-01-01

    Recent studies suggest that alpine and arctic organisms may have distinctly different phylogeographic histories from temperate or tropical taxa, with recent range contraction into interglacial refugia as opposed to post-glacial expansion out of refugia. We use a combination of phylogeographic inference, demographic reconstructions, and hierarchical Approximate Bayesian Computation to test for phylodemographic concordance among five species of alpine-adapted small mammals in eastern Beringia. These species (Collared Pikas, Hoary Marmots, Brown Lemmings, Arctic Ground Squirrels, and Singing Voles) vary in specificity to alpine and boreal-tundra habitat but share commonalities (e.g., cold tolerance and nunatak survival) that might result in concordant responses to Pleistocene glaciations. All five species contain a similar phylogeographic disjunction separating eastern and Beringian lineages, which we show to be the result of simultaneous divergence. Genetic diversity is similar within each haplogroup for each species, and there is no support for a post-Pleistocene population expansion in eastern lineages relative to those from Beringia. Bayesian skyline plots for four of the five species do not support Pleistocene population contraction. Brown Lemmings show evidence of late Quaternary demographic expansion without subsequent population decline. The Wrangell-St. Elias region of eastern Alaska appears to be an important zone of recent secondary contact for nearctic alpine mammals. Despite differences in natural history and ecology, similar phylogeographic histories are supported for all species, suggesting that these, and likely other, alpine- and arctic-adapted taxa are already experiencing population and/or range declines that are likely to synergistically accelerate in the face of rapid climate change. Climate change may therefore be acting as a double-edged sword that erodes genetic diversity within populations but promotes divergence and the generation of

  18. Comparative phylogeography highlights the double-edged sword of climate change faced by arctic- and alpine-adapted mammals.

    PubMed

    Lanier, Hayley C; Gunderson, Aren M; Weksler, Marcelo; Fedorov, Vadim B; Olson, Link E

    2015-01-01

    Recent studies suggest that alpine and arctic organisms may have distinctly different phylogeographic histories from temperate or tropical taxa, with recent range contraction into interglacial refugia as opposed to post-glacial expansion out of refugia. We use a combination of phylogeographic inference, demographic reconstructions, and hierarchical Approximate Bayesian Computation to test for phylodemographic concordance among five species of alpine-adapted small mammals in eastern Beringia. These species (Collared Pikas, Hoary Marmots, Brown Lemmings, Arctic Ground Squirrels, and Singing Voles) vary in specificity to alpine and boreal-tundra habitat but share commonalities (e.g., cold tolerance and nunatak survival) that might result in concordant responses to Pleistocene glaciations. All five species contain a similar phylogeographic disjunction separating eastern and Beringian lineages, which we show to be the result of simultaneous divergence. Genetic diversity is similar within each haplogroup for each species, and there is no support for a post-Pleistocene population expansion in eastern lineages relative to those from Beringia. Bayesian skyline plots for four of the five species do not support Pleistocene population contraction. Brown Lemmings show evidence of late Quaternary demographic expansion without subsequent population decline. The Wrangell-St. Elias region of eastern Alaska appears to be an important zone of recent secondary contact for nearctic alpine mammals. Despite differences in natural history and ecology, similar phylogeographic histories are supported for all species, suggesting that these, and likely other, alpine- and arctic-adapted taxa are already experiencing population and/or range declines that are likely to synergistically accelerate in the face of rapid climate change. Climate change may therefore be acting as a double-edged sword that erodes genetic diversity within populations but promotes divergence and the generation of

  19. Breaking the double-edged sword of effort/trying hard: Developmental equilibrium and longitudinal relations among effort, achievement, and academic self-concept.

    PubMed

    Marsh, Herbert W; Pekrun, Reinhard; Lichtenfeld, Stephanie; Guo, Jiesi; Arens, A Katrin; Murayama, Kou

    2016-08-01

    Ever since the classic research of Nicholls (1976) and others, effort has been recognized as a double-edged sword: while it might enhance achievement, it undermines academic self-concept (ASC). However, there has not been a thorough evaluation of the longitudinal reciprocal effects of effort, ASC, and achievement, in the context of modern self-concept theory and statistical methodology. Nor have there been developmental equilibrium tests of whether these effects are consistent across the potentially volatile early-to-middle adolescence. Hence, focusing on mathematics, we evaluate reciprocal effects models (REMs) over the first 4 years of secondary school (grades 5-8), relating effort, achievement (test scores and school grades), ASC, and ASC × Effort interactions for a representative sample of 3,144 German students (Mage = 11.75 years at Wave 1). ASC, effort, and achievement were positively correlated at each wave, and there was a clear pattern of positive reciprocal positive effects among ASC, test scores, and school grades-each contributing to the other, after controlling for the prior effects of all others. There was an asymmetrical pattern of effects for effort that is consistent with the double-edged sword premise: prior school grades had positive effects on subsequent effort, but prior effort had nonsignificant or negative effects on subsequent grades and ASC. However, on the basis of a synergistic application of new theory and methodology, we predicted and found a significant ASC × Effort interaction, such that prior effort had more positive effects on subsequent ASC and school grades when prior ASC was high-thus providing a key to breaking the double-edged sword. (PsycINFO Database Record PMID:27455188

  20. DNA Polymerases λ and β: The Double-Edged Swords of DNA Repair.

    PubMed

    Mentegari, Elisa; Kissova, Miroslava; Bavagnoli, Laura; Maga, Giovanni; Crespan, Emmanuele

    2016-01-01

    DNA is constantly exposed to both endogenous and exogenous damages. More than 10,000 DNA modifications are induced every day in each cell's genome. Maintenance of the integrity of the genome is accomplished by several DNA repair systems. The core enzymes for these pathways are the DNA polymerases. Out of 17 DNA polymerases present in a mammalian cell, at least 13 are specifically devoted to DNA repair and are often acting in different pathways. DNA polymerases β and λ are involved in base excision repair of modified DNA bases and translesion synthesis past DNA lesions. Polymerase λ also participates in non-homologous end joining of DNA double-strand breaks. However, recent data have revealed that, depending on their relative levels, the cell cycle phase, the ratio between deoxy- and ribo-nucleotide pools and the interaction with particular auxiliary proteins, the repair reactions carried out by these enzymes can be an important source of genetic instability, owing to repair mistakes. This review summarizes the most recent results on the ambivalent properties of these enzymes in limiting or promoting genetic instability in mammalian cells, as well as their potential use as targets for anticancer chemotherapy. PMID:27589807

  1. Perspective: Engineering Education's Three-Edged Sword.

    ERIC Educational Resources Information Center

    LeBold, William K.

    1983-01-01

    Engineering and engineering education have continually faced a problem regarding quantity, quality, and equity (the traditional three-edged sword). Each of these three areas is defined and discussed. Suggests that these areas can be controlled only by anticipating the challenges of the next two decades. (JN)

  2. The HIV/AIDS caregiver identity as a double-edged sword: a discourse analysis on HIV/AIDS caregiving in South Africa.

    PubMed

    Ranjbar, Vania

    2014-09-01

    This article discusses the identity of HIV/AIDS caregivers as constructed by a group of HIV/AIDS caregivers at a non-profit organisation in South Africa. During a 12-month period data were collected through interviews with the organisation's staff and volunteers. Using discourse analysis, the study identified a caregiver identity constructed by participants. This caregiving identity acts as a double-edged sword: while the rewards of caregiving act as a buffer against stressful experiences, the prescriptive nature of the caregiver identity is taxing, and may explain burnout among HIV/AIDS caregivers. The study concludes that for support systems for HIV/AIDS caregivers to be effective, the social culture and identity of HIV/AIDS caregivers must be considered. PMID:25388980

  3. The double-edged sword of genetic accounts of criminality: causal attributions from genetic ascriptions affect legal decision making.

    PubMed

    Cheung, Benjamin Y; Heine, Steven J

    2015-12-01

    Much debate exists surrounding the applicability of genetic information in the courtroom, making the psychological processes underlying how people consider this information important to explore. This article addresses how people think about different kinds of causal explanations in legal decision-making contexts. Three studies involving a total of 600 Mechanical Turk and university participants found that genetic, versus environmental, explanations of criminal behavior lead people to view the applicability of various defense claims differently, perceive the perpetrator's mental state differently, and draw different causal attributions. Moreover, mediation and path analyses highlight the double-edged nature of genetic attributions-they simultaneously reduce people's perception of the perpetrator's sense of control while increasing people's tendencies to attribute the cause to internal factors and to expect the perpetrator to reoffend. These countervailing relations, in turn, predict sentencing in opposite directions, although no overall differences in sentencing or ultimate verdicts were found. PMID:26498975

  4. Uncoupling and reactive oxygen species (ROS)--a double-edged sword for β-cell function? "Moderation in all things".

    PubMed

    Collins, Sheila; Pi, Jingbo; Yehuda-Shnaidman, Einav

    2012-12-01

    The ability of the mitochondrion to (a) manage fuel import to oxidize for adenosine tri-phosphate (ATP) generation while (b) protecting itself and the cellular environment from electron leak, which can generate highly reactive oxygen species (ROS) is a delicate balancing act. ATP is the currency of the cell and as such serves a signaling function as a substrate partner to many kinases and ion channels. While various ROS species have been viewed as a dangerous and toxic group of molecules, it also has a role as a signal derived from mitochondria, as well as other enzymatic sources: a double-edged sword. Current efforts to understand the biochemical mechanisms affected by ROS as a signal--usually noted to be hydrogen peroxide (H(2)O(2))--are exciting, but this duality of ROS effects also pose challenges in managing its levels to protect cells. The mitochondrial uncoupling protein-2 (UCP2), UCP3, and the permeability transition pore have been integral to efforts to try to understand what role mitochondrial-derived ROS have in cells. In this piece we reflect on mitochondrial ROS and uncoupling proteins as signaling regulators. It seems that when it comes to ROS and uncoupling the proverb "Moderation in all things" is apt. PMID:23168277

  5. The double-edged sword of ovarian cancer information for women at increased risk who have previously taken part in screening

    PubMed Central

    Smits, Stephanie; Boivin, Jacky; Menon, Usha; Brain, Kate

    2016-01-01

    Background Women at increased risk who decide not to have, or to delay, risk-reducing salpingo-oophorectomy have to rely on early diagnosis through symptom awareness and presenting to primary care as soon as possible in the absence of screening. However, little is known about the acceptability to women of this strategy. We aimed to gain an in-depth understanding of women’s perceptions and previous experiences of ovarian cancer symptom management, and the influences on ovarian cancer awareness and anticipated symptom presentation. Method Qualitative interviews were conducted with eight women at increased risk of ovarian cancer who had previously taken part in ovarian cancer screening and analysed using interpretative phenomenological analysis (IPA). Results Familial experience of ovarian cancer and perceived personal risk shaped women’s perceptions and behavioural responses to disease threat. Ovarian cancer information was perceived to be a double-edged sword, regarded as either useful for increasing knowledge and confidence in discussing symptom concerns with health professionals or to be avoided due to fears about cancer. Conclusion Women may be cautious about searching for information independently and in the absence of routine ovarian screening. Practice implications Thought needs to be given to how best to create and disseminate credible ovarian cancer symptom information materials. PMID:27433283

  6. Thiolate ligands as a double-edged sword for CO oxidation on CeO2-supported Au25(SR)18 nanoclusters

    SciTech Connect

    Wu, Zili; Jiang, Deen; Mann, Amanda K; Mullins, David R; Qiao, Zhen-an; Allard Jr, Lawrence Frederick; Zeng, Chenjie; Jin, Rongchao; Overbury, Steven {Steve} H

    2014-01-01

    The effect of thiolate ligands was explored on the catalysis of CeO2-rod supported Au25(SR)18 (SR = -SCH2-CH2-Ph) by using CO oxidation as a probe reaction. Reaction kinetic tests, in situ IR and X-ray absorption spectroscopy, and density functional theory (DFT) were employed to understand how the thiolate ligands affect the nature of active sites, activation of CO and O2, as well as the reaction mechanism and kinetics. The intact Au25(SR)18 on CeO2-rod is found not able to adsorb CO. Only when the thiolate ligands are partially removed, starting from the interface between Au25(SR)18 and CeO2 at temperatures of 423 K and above, can the adsorption of CO be observed by IR. DFT calculations suggest that CO adsorbs favorably on the exposed gold atoms. Accordingly, the CO oxidation light-off temperature shifts to lower temperature. Several types of Au sites are probed by IR of CO adsorption during the ligand removal process. The cationic Au sites (charged between 0 and +1) are found to play the major role for low temperature CO oxidation. Similar activation energy and reaction rate are found for CO oxidation on differently treated Au25(SR)18/CeO2-rod, suggesting a simple site-blocking effect of the thiolate ligands in Au nanoclusters catalysis. Isotopic labelling experiments clearly indicate that CO oxidation on Au25(SR)18/CeO2-rod proceeds predominantly via the redox mechanism where CeO2 activates O2 while CO is activated on the de-thiolated gold sites. These results points to a double-edged sword role played by the thiolate ligands on Au25 nanoclusters for CO oxidation.

  7. Hexokinase II: cancer's double-edged sword acting as both facilitator and gatekeeper of malignancy when bound to mitochondria.

    PubMed

    Mathupala, S P; Ko, Y H; Pedersen, P L

    2006-08-01

    A key hallmark of many cancers, particularly the most aggressive, is the capacity to metabolize glucose at an elevated rate, a phenotype detected clinically using positron emission tomography (PET). This phenotype provides cancer cells, including those that participate in metastasis, a distinct competitive edge over normal cells. Specifically, after rapid entry of glucose into cancer cells on the glucose transporter, the highly glycolytic phenotype is supported by hexokinase (primarily HK II) that is overexpressed and bound to the outer mitochondrial membrane via the porin-like protein voltage-dependent anion channel (VDAC). This protein and the adenine nucleotide transporter move ATP, newly synthesized by the inner membrane located ATP synthase, to active sites on HK II. The abundant amounts of HK II bind both the ATP and the incoming glucose producing the product glucose-6-phosphate, also at an elevated rate. This critical metabolite then serves both as a biosynthetic precursor to support cell proliferation and as a precursor for lactic acid, the latter exiting cancer cells causing an unfavorable environment for normal cells. Although helping facilitate this chemical warfare, HK II via its mitochondrial location also suppresses the death of cancer cells, thus increasing their possibility for metastasis and the ultimate death of the human host. For these reasons, targeting this key enzyme is currently being investigated in several laboratories in a strategy to develop novel therapies that may turn the tide on the continuing struggle to find effective cures for cancer. One such candidate is 3-bromopyruvate that has been shown recently to eradicate advanced stage, PET positive hepatocellular carcinomas in an animal model without apparent harm to the animals. PMID:16892090

  8. Double-Edge Sword of Sustained ROCK Activation in Prion Diseases through Neuritogenesis Defects and Prion Accumulation

    PubMed Central

    Alleaume-Butaux, Aurélie; Nicot, Simon; Pietri, Mathéa; Baudry, Anne; Dakowski, Caroline; Tixador, Philippe; Ardila-Osorio, Hector; Haeberlé, Anne-Marie; Bailly, Yannick; Peyrin, Jean-Michel; Launay, Jean-Marie; Kellermann, Odile; Schneider, Benoit

    2015-01-01

    In prion diseases, synapse dysfunction, axon retraction and loss of neuronal polarity precede neuronal death. The mechanisms driving such polarization defects, however, remain unclear. Here, we examined the contribution of RhoA-associated coiled-coil containing kinases (ROCK), key players in neuritogenesis, to prion diseases. We found that overactivation of ROCK signaling occurred in neuronal stem cells infected by pathogenic prions (PrPSc) and impaired the sprouting of neurites. In reconstructed networks of mature neurons, PrPSc-induced ROCK overactivation provoked synapse disconnection and dendrite/axon degeneration. This overactivation of ROCK also disturbed overall neurotransmitter-associated functions. Importantly, we demonstrated that beyond its impact on neuronal polarity ROCK overactivity favored the production of PrPSc through a ROCK-dependent control of 3-phosphoinositide-dependent kinase 1 (PDK1) activity. In non-infectious conditions, ROCK and PDK1 associated within a complex and ROCK phosphorylated PDK1, conferring basal activity to PDK1. In prion-infected neurons, exacerbated ROCK activity increased the pool of PDK1 molecules physically interacting with and phosphorylated by ROCK. ROCK-induced PDK1 overstimulation then canceled the neuroprotective α-cleavage of normal cellular prion protein PrPC by TACE α-secretase, which physiologically precludes PrPSc production. In prion-infected cells, inhibition of ROCK rescued neurite sprouting, preserved neuronal architecture, restored neuronal functions and reduced the amount of PrPSc. In mice challenged with prions, inhibition of ROCK also lowered brain PrPSc accumulation, reduced motor impairment and extended survival. We conclude that ROCK overactivation exerts a double detrimental effect in prion diseases by altering neuronal polarity and triggering PrPSc accumulation. Eventually ROCK emerges as therapeutic target to combat prion diseases. PMID:26241960

  9. Computational fluid dynamics: A two-edged sword

    SciTech Connect

    Baker, A.J.; Kelso, R.M.; Gordon, E.B.; Roy, S.; Schaub, E.G.

    1997-08-01

    This article examines computational fluid dynamics (CFD) limitations as a design tool. Two decades have passed since the first paper was published in the ASHRAE Transactions suggesting the use of CFD for quantitative prediction of room air motion. CFD is an emerging methodology, with roots in the defense/aerospace industry, wherein a mathematical model of fluid flow is converted into a digital computational procedure, yielding numbers that approximate the solution of this modeled system, hence the genuine flow state. CFD methodology has indeed brought bright glimmers of an ability to establish firm quantitative data regarding how room air moves. In fact, CFD can predict fluid levels and pressure differences to very low levels, that are essentially impossible to experimentally measure. However, a CFD model constitutes the culmination of a large number of assumptions and approximations, such that the answers produced are essentially never correct. Further, it is the very approximation process in CFD theory that leads to intrinsic error mechanisms that can range from benign to pathological. The ASHRAE professional who seeks to use CFD to assist in system design needs to be fully aware of these two edges of the CFD sword.

  10. Mitochondrial UPR: A Double-Edged Sword.

    PubMed

    Tian, Ye; Merkwirth, Carsten; Dillin, Andrew

    2016-08-01

    The mitochondrial unfolded protein response (UPR(mt)) promotes the recovery of dysfunctional mitochondria. Surprisingly, UPR(mt) activation inadvertently maintains and propagates the deleterious mtDNA in a heteroplasmic Caenorhabditis elegans strain, with detrimental consequences. This study extends our understanding of the UPR(mt) and provides a possible therapeutic target for diseases associated with mtDNA mutations. PMID:27394966

  11. Double-edged sword called technology

    SciTech Connect

    Weisskopf, V.F.

    1980-04-01

    The growing awareness that technological achievements have shortcomings may be an indication of a maturing society developing higher values. Technology developed in response to specific questions about nature; science from the systematic study of the details of nature. The two became linked as scientific knowlege was applied to technological problems, and this altered the structure of society. The positive benefits of this symbiosis have been a longer and better life for much of the world. The negative sides are material and spiritual pollution. Material pollution can be solved only if nuclear war is avoided. By bringing purpose and meaning to individual lives, a popular control of technology could evolve to humanize the social-industrial structure and eliminate spiritual pollution. (DCK)

  12. The precautionary principle: a double edged sword?

    PubMed

    Kirkland, Mark

    2010-08-01

    There is no doubt that the introduction of quality system principles and regulation to blood and tissue services in the 1990's has brought about significant improvements in the control of processes and the quality of products being released for patient care. But, as regulation extends into new areas of cellular and tissue therapy, it is perhaps time to review the regulatory paradigm within which we work, and the principles that underpin it. At what point do the costs of regulation exceed the benefits to be gained? At what point to regulations cease to yield measurable benefits to patient care and safety at all, but instead become simply a burden on service providers and businesses, and ultimately the community as a whole? And is there a point at which regulation actually compromises patient care and safety, or the development of new technologies? In the early stages of regulation, there is demonstrable cost-benefit as assessed by product quality and patient outcomes. However, there is inevitably a "law of diminishing returns", whereby the degree of improvement that can be achieved decreases and the cost of achieving that benefit increases. What has not yet been determined is whether, as regulations and regulators become more precise and more demanding, there remains a measurable net cost benefit over time, or whether there is a point at which the cost of further improvement matches, or even exceeds, the benefits to be gained. A key underpinning of the regulatory philosophy is the "Precautionary Principle". This paper will focus on the application of the Precautionary Principle in the area of blood and tissues, which encompasses the burgeoning field of cellular therapies. PMID:20512629

  13. Calcium supplement: humanity's double-edged sword.

    PubMed

    Bunyaratavej, Narong; Buranasinsup, Shutipen

    2011-10-01

    The principle aim of the present study is to investigate the dark side of calcium, pollutions in calcium preparation especially lead (Pb), mercury (Hg) and cadmium (Cd). The collected samples were the different calcium salts in the market and 18 preparations which were classified into 3 groups: Calcium carbonate salts, Chelated calcium and natural-raw calcium. All samples were analyzed for lead, cadmium and mercury by inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique, in house method based on AOAC (2005) 999.10 by ICP-MS. The calcium carbonate and the natural-raw calcium in every sample contained lead at 0.023-0.407 mg/kg of calcium powder. Meanwhile, the natural-raw calcium such as oyster, coral and animal bone showed amount of lead at 0.106-0.384 mg/kg with small amounts of mercury and cadmium. The chelated calcium such as calcium gluconate, calcium lactate and calcium citrate are free of lead. PMID:22338928

  14. Characterization of a Messer – The late-Medieval single-edged sword of Central Europe

    SciTech Connect

    Fajfar, Peter; Medved, Jožef; Klančnik, Grega; Lazar, Tomaž; Nečemer, Marijan; Mrvar, Primož

    2013-12-15

    Metallurgical characterization of a sword blade fragments dating from the second half of the 15th century found in central Slovenia was performed in order to determine its chemical composition, microstructure, microhardness, and to obtain insight into the methods of manufacture of a late-medieval Messer sword. As the artefact was broken, examinations were limited to six very small fragments that were allowed to be removed from the cutting edge, core and the back of the blade. Light optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence spectrometry, differential scanning calorimetry, thermodynamics approach and Vickers micro-hardness tests were employed to analyze the microstructure and mechanical properties. The results show that the sword was manufactured from a single wrought iron billet. The surface of the sword was carburized. No evidence of quenching was found. The ferritic microstructure is concentrated in the core, and the pearlitic in the outer layer of the blade. All metal fragments contained non-metallic inclusions that were derived mostly from slag and some from hammer scale. - Highlights: • A metallurgical characterization of a medieval sword blade has been performed. • The carbon content decreased from the surface to the core of the blade. • The dominant microstructure in the outer layer is pearlite and in the core is ferrite. • The presence of lump shaped and elongated non-metallic inclusions was observed. • The sword was manufactured from a single wrought iron billet.

  15. Stem cells, a two-edged sword: Risks and potentials of regenerative medicine

    PubMed Central

    Piscaglia, Anna Chiara

    2008-01-01

    The recent advancements in stem cell (SC) biology have led to the concept of regenerative medicine, which is based on the potential of SC for therapies aimed to facilitate the repair of degenerating or injured tissues. Nonetheless, prior to large scale clinical applications, critical aspects need to be further addressed, including the long-term safety, tolerability, and efficacy of SC-based treatments. Most problematic among the risks of SC-based therapies, in addition to the possible rejection or loss of function of the infused cells, is their potential neoplastic transformation. Indeed, SCs may be used to cure devastating diseases, but their specific properties of self-renewal and clonogenicity may render them prone to generate cancers. In this respect, ‘Stemness’ might be seen as a two-edged sword, its bright side being represented by normal SCs, its dark side by cancer SCs. A better understanding of SC biology will help fulfill the promise of regenerative medicine aimed at curing human pathologies and fighting cancer from its roots. PMID:18666313

  16. Manipulation of BCG vaccine: a double-edged sword.

    PubMed

    Singh, V K; Srivastava, R; Srivastava, B S

    2016-04-01

    Mycobacterium bovis Bacillus Calmette-Guérin (BCG), an attenuated vaccine derived from M. bovis, is the only licensed vaccine against tuberculosis (TB). Despite its protection against TB in children, the protective efficacy in pulmonary TB is variable in adolescents and adults. In spite of the current knowledge of molecular biology, immunology and cell biology, infectious diseases such as TB and HIV/AIDS are still challenges for the scientific community. Genetic manipulation facilitates the construction of recombinant BCG (rBCG) vaccine that can be used as a highly immunogenic vaccine against TB with an improved safety profile, but, still, the manipulation of BCG vaccine to improve efficacy should be carefully considered, as it can bring in both favourable and unfavourable effects. The purpose of this review is not to comprehensively review the interaction between microorganisms and host cells in order to use rBCG expressing M. tuberculosis (Mtb) immunodominant antigens that are available in the public domain, but, rather, to also discuss the limitations of rBCG vaccine, expressing heterologous antigens, during manipulation that pave the way for a promising new vaccine approach. PMID:26810060

  17. Double-Edged Sword: Social Media Use in the Classroom

    ERIC Educational Resources Information Center

    Chromey, Kelli J.; Duchsherer, Amy; Pruett, Jennifer; Vareberg, Kyle

    2016-01-01

    The purpose of this research is to identify the students' perceptions of social media use in a classroom setting. Knowing students' perceptions of social media can help the instructor build a course that both student and teacher can find effective. Using focus groups this study found a model to determine if social media is an appropriate or…

  18. Reactive oxygen species a double-edged sword for mesothelioma

    PubMed Central

    Catalani, Simona; Galati, Rossella

    2015-01-01

    It is well known that oxidative stress can lead to chronic inflammation which, in turn, could mediate most chronic diseases including cancer. Oxidants have been implicated in the activity of crocidolite and amosite, the most powerful types of asbestos associated to the occurrence of mesothelioma. Currently rates of mesothelioma are rising and estimates indicate that the incidence of mesothelioma will peak within the next 10–15 years in the western world, while in Japan the peak is predicted not to occur until 40 years from now. Although the use of asbestos has been banned in many countries around the world, production of and the potentially hazardous exposure to asbestos is still present with locally high incidences of mesothelioma. Today a new man-made material, carbon nanotubes, has arisen as a concern; carbon nanotubes may display ‘asbestos-like’ pathogenicity with mesothelioma induction potential. Carbon nanotubes resulted in the greatest reactive oxygen species generation. How oxidative stress activates inflammatory pathways leading to the transformation of a normal cell to a tumor cell, to tumor cell survival, proliferation, invasion, angiogenesis, chemoresistance, and radioresistance, is the aim of this review. PMID:26078352

  19. Opioids and Viral Infections: A Double-Edged Sword

    PubMed Central

    Tahamtan, Alireza; Tavakoli-Yaraki, Masoumeh; Mokhtari-Azad, Talat; Teymoori-Rad, Majid; Bont, Louis; Shokri, Fazel; Salimi, Vahid

    2016-01-01

    Opioids and their receptors have received remarkable attention because they have the ability to alter immune function, which affects disease progression. In vitro and in vivo findings as well as observations in humans indicate that opioids and their receptors positively or negatively affect viral replication and virus-mediated pathology. The present study reviews recent insights in the role of opioids and their receptors in viral infections and discusses possible therapeutic opportunities. This review supports the emerging concept that opioids and their receptors have both favorable and unfavorable effects on viral disease, depending on the type of virus. Targeting of the opioid system is a potential option for developing effective therapies; however caution is required in relation to the beneficial functions of opioid systems. PMID:27446011

  20. Playing with a double-edged sword: Analogies in biochemistry

    NASA Astrophysics Data System (ADS)

    Orgill, Marykay

    Analogy pervades our everyday reasoning. No situation we encounter is exactly like a situation we have encountered previously, and our ability to learn and survive in the world is based on our ability to find similarities between past and present situations and use the knowledge we have gained from past situations to manage current situations. Analogies can be powerful teaching tools because they can make new material intelligible to students by comparing it to material that is already familiar. It is clear, though, that not all analogies are good and that not all good analogies are useful to all students. In this study, I have used textbook analysis, classroom observations, student interviews and instructor interviews to determine the role that analogies play in biochemistry learning. Analogies are an important teaching technique in biochemistry classes, being used more often in both biochemistry classes and textbooks than they are in high school chemistry classes and textbooks. Most biochemistry students like, pay particular attention to, and remember the analogies their instructors provide; and they use these analogies to understand, visualize, and recall information from class. Even though students like and use analogies, they do not understand what analogies are or the mechanism by which they improve learning. For the students, analogies are simply any teaching technique that eases understanding, visualization, or recall. Instructors, on the other hand, have a good understanding of what analogies are and of how they should be presented in class; but they do not use analogies as effectively as they should. They do not plan, explain or identify the limitations of the analogies they use in class. However, regardless of how effectively instructors present analogies in class, this study indicates that, in general, analogies are useful in promoting understanding, visualization, recall, and motivation in biochemistry students at all levels. They would be even more useful if students understood what analogies are and how they can be used to improve understanding of biochemical concepts.

  1. Concrete Instantiations of Mathematics: A Double-Edged Sword

    ERIC Educational Resources Information Center

    Kaminski, Jennifer A.; Sloutsky, Vladimir M.; Heckler, Andrew F.

    2009-01-01

    What factors affect transfer of knowledge is a complex question. In recent research, the authors demonstrated that concreteness of the learning domain is one such factor (Kaminski, Sloutsky, & Heckler, 2008). Even when prompted and given no time delay, participants who learned a concrete instantiation of a mathematical concept failed to transfer…

  2. White Adipose Tissue Browning: A Double-edged Sword.

    PubMed

    Abdullahi, Abdikarim; Jeschke, Marc G

    2016-08-01

    The study of white adipose tissue (WAT) 'browning' has become a 'hot topic' in various acute and chronic metabolic conditions, based on the idea that WAT browning might be able to facilitate weight loss and improve metabolic health. However, this view cannot be translated into all areas of medicine. Recent studies identified effects of browning associated with adverse outcomes, and as more studies are being conducted, a very different picture has emerged about WAT browning and its detrimental effect in acute and chronic hypermetabolic conditions. Therefore, the notion that browning is supposedly beneficial may be inadequate. In this review we analyze how and why browning in chronic hypermetabolic associated diseases can be detrimental and lead to adverse outcomes. PMID:27397607

  3. Nodulation outer proteins: double-edged swords of symbiotic rhizobia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizobia are nitrogen-fixing bacteria that establish a nodule symbiosis with legumes. Nodule formation is the result of a complex bacterial infection process, which depends on signals and surface determinants produced by both symbiotic partners. Among them, rhizobial nodulation outer proteins (Nops)...

  4. Enzyme cofactors: Double-edged sword for catalysis

    NASA Astrophysics Data System (ADS)

    Ivanov, Ivaylo

    2013-01-01

    The metal cofactors responsible for the activity of CDK2 -- a representative member of the kinase superfamily of enzymes -- have now been shown to also have inhibitory effects during the catalytic cycle.

  5. Endowment Spending--A Double-Edged Sword

    ERIC Educational Resources Information Center

    Basch, Donald L.

    2004-01-01

    The growing ability of private colleges and universities to use a high level of annual endowment spending in support of current operations has been a source of financial strength during much of the past two decades. More recently, however, declining endowments at most colleges have raised concerns about declines in the availability of …

  6. Autophagy: A double-edged sword in intervertebral disk degeneration.

    PubMed

    Zhang, Shu-Jun; Yang, Wei; Wang, Cheng; He, Wen-Si; Deng, Hai-Yang; Yan, Yi-Guo; Zhang, Jian; Xiang, Yong-Xiao; Wang, Wen-Jun

    2016-06-01

    Autophagy is a homeostatic mechanism through which intracellular damaged organelles and proteins are degraded and recycled in response to increased metabolic demands or stresses. Although primarily cytoprotective, dysfunction of autophagy is often associated with many degenerative diseases, including intervertebral disc (IVD) degeneration (IDD). As a main contributing factor to low back pain, IDD is the pathological basis for various debilitating spinal diseases. Either higher or lower levels of autophagy are observed in degenerative IVD cells. Despite the precise role of autophagy in disc degeneration that is still controversial, with difference from protection to aggravation, targeting autophagy has shown promise for mitigating disc degeneration. In the current review, we summarize the changes of autophagy in degenerative IVD cells and mainly discuss the relationship between autophagy and IDD. With continued efforts, modulation of the autophagic process could be a potential and attractive therapeutic strategy for degenerative disc disease. PMID:27018178

  7. Exercise and Arrhythmias: A Double-Edged Sword.

    PubMed

    Manolis, Antonis S; Manolis, Antonis A

    2016-07-01

    Ample evidence indicates that moderate regular exercise is beneficial for both normal individuals and patients with cardiovascular (CV) disease. However, intense and strenuous exercise in individuals with evident or occult underlying CV abnormalities may have adverse effects with provocation and exacerbation of arrhythmias that may lead to life-threatening situations. Both of these aspects of exercise-induced effects are herein reviewed. PMID:27120033

  8. The "Double-Edged Sword" of the Adult Learning Environment

    ERIC Educational Resources Information Center

    Murray, Sara; Mitchell, Jane

    2013-01-01

    The vocational education and training sector plays a critical role in the provision of educational opportunities for young adults who have left school prior to completing a qualification. Some research has found that a major factor that supports student re-engagement in formal education is the "adult learning environment" that characterises…

  9. [New therapy for AIDS: a double-edged sword].

    PubMed

    Foreman, M

    1996-01-01

    The main theme of the XI AIDS International Conference, held in Vancouver, was the new combination treatments using antiretroviral drugs to reduce the presence of the HIV virus. Clinical studies have shown a significant reduction in viral load due to using protease inhibitors. Although a promising treatment, its annual cost can reach $30,000. Activists voice their opinions on the high cost of these drugs. PMID:11364382

  10. Open abdomen in trauma patients: a double-edged sword.

    PubMed

    Huang, Yu-Hua; Li, You-Sheng

    2016-01-01

    The use of open abdomen (OA) as a technique in the treatment of exsanguinating trauma patients was first described in the mid-19(th) century. Since the 1980s, OA has become a relatively new and increasingly common strategy to manage massive trauma and abdominal catastrophes. OA has been proven to help reduce the mortality of trauma. Nevertheless, the OA method may be associated with terrible and devastating complications such as enteroatmospheric fistula (EAF). As a result, OA should not be overused, and attention should be given to critical care as well as special management. The temporary abdominal closure (TAC) technique after abbreviated laparotomy was used to improve wound healing and facilitate final fascial closure of OA. Negative pressure therapy (NPT) is the most commonly used TAC method. PMID:27042329

  11. Fluid Therapy: Double-Edged Sword during Critical Care?

    PubMed Central

    Benes, Jan; Kirov, Mikhail; Kuzkov, Vsevolod; Lainscak, Mitja; Molnar, Zsolt; Voga, Gorazd; Monnet, Xavier

    2015-01-01

    Fluid therapy is still the mainstay of acute care in patients with shock or cardiovascular compromise. However, our understanding of the critically ill pathophysiology has evolved significantly in recent years. The revelation of the glycocalyx layer and subsequent research has redefined the basics of fluids behavior in the circulation. Using less invasive hemodynamic monitoring tools enables us to assess the cardiovascular function in a dynamic perspective. This allows pinpointing even distinct changes induced by treatment, by postural changes, or by interorgan interactions in real time and enables individualized patient management. Regarding fluids as drugs of any other kind led to the need for precise indication, way of administration, and also assessment of side effects. We possess now the evidence that patient centered outcomes may be altered when incorrect time, dose, or type of fluids are administered. In this review, three major features of fluid therapy are discussed: the prediction of fluid responsiveness, potential harms induced by overzealous fluid administration, and finally the problem of protocol-led treatments and their timing. PMID:26798642

  12. Inflammasomes in cancer: a double-edged sword.

    PubMed

    Kolb, Ryan; Liu, Guang-Hui; Janowski, Ann M; Sutterwala, Fayyaz S; Zhang, Weizhou

    2014-01-01

    Chronic inflammatory responses have long been observed to be associated with various types of cancer and play decisive roles at different stages of cancer development. Inflammasomes, which are potent inducers of interleukin (IL)-1β and IL-18 during inflammation, are large protein complexes typically consisting of a Nod-like receptor (NLR), the adapter protein ASC, and Caspase-1. During malignant transformation or cancer therapy, the inflammasomes are postulated to become activated in response to danger signals arising from the tumors or from therapy-induced damage to the tumor or healthy tissue. The activation of inflammasomes plays diverse and sometimes contrasting roles in cancer promotion and therapy depending on the specific context. Here we summarize the role of different inflammasome complexes in cancer progression and therapy. Inflammasome components and pathways may provide novel targets to treat certain types of cancer; however, using such agents should be cautiously evaluated due to the complex roles that inflammasomes and pro-inflammatory cytokines play in immunity. PMID:24474192

  13. Autophagy in Health and Disease: A Double-Edged Sword

    PubMed Central

    Shintani, Takahiro; Klionsky, Daniel J.

    2006-01-01

    Autophagy, the process by which cells recycle cytoplasm and dispose of excess or defective organelles, has entered the research spotlight largely owing to the discovery of the protein components that drive this process. Identifying the autophagy genes in yeast and finding orthologs in other organisms reveals the conservation of the mechanism of autophagy in eukaryotes and allows the use of molecular genetics and biology in different model systems to study this process. By mostly morphological studies, autophagy has been linked to disease processes. Whether autophagy protects from or causes disease is unclear. Here, we summarize current knowledge about the role of autophagy in disease and health. PMID:15528435

  14. The Double-edged Sword of Autophagy Modulation in Cancer

    PubMed Central

    White, Eileen; DiPaola, Robert S.

    2009-01-01

    Macroautophagy (autophagy) is a lysosomal degradation pathway for the breakdown of intracellular proteins and organelles. Although, constitutive autophagy is a homeostatic mechanism for intracellular recycling and metabolic regulation, autophagy is also stress responsive where it is important for the removal of damaged proteins and organelles. Autophagy thereby confers stress tolerance, limits damage and sustains viability under adverse conditions. Autophagy is a tumor suppression mechanism yet it enables tumor cell survival in stress. Reconciling how loss of a prosurvival function can promote tumorigenesis, emerging evidence suggests that preservation of cellular fitness by autophagy may be key to tumor suppression. As autophagy is such a fundamental process, establishing how the functional status of autophagy influences tumorigenesis and treatment response is important. This is especially critical as many current cancer therapeutics activate autophagy. Therefore, efforts to understand and modulate the autophagy pathway will provide new approaches to cancer therapy and prevention. PMID:19706824

  15. The double-edged sword: Neurotoxicity of chemotherapy.

    PubMed

    Magge, Rajiv S; DeAngelis, Lisa M

    2015-03-01

    The number of available therapies for hematologic malignancies continues to grow at a rapid pace. Unfortunately, many of these treatments carry both central and peripheral nervous system toxicities, potentially limiting a patient's ability to tolerate a full course of treatment. Neurotoxicity with chemotherapy is common and second only to myelosuppression as a reason to limit dosing. This review addresses the neurotoxicity of newly available therapeutic agents including brentuximab vedotin and blinatumomab as well as classic ones such as methotrexate, vinca alkaloids and platinums. Although peripheral neuropathy is common with many drugs, other complications such as seizures and encephalopathy may require more immediate attention. Rapid recognition of adverse neurologic effects may lead to earlier treatment and appropriate adjustment of dosing regimens. In addition, knowledge of common toxicities may help differentiate chemotherapy-related symptoms from actual progression of cancer into the CNS. PMID:25445718

  16. Ibrutinib-A double-edge sword in cancer and autoimmune disorders.

    PubMed

    Kokhaei, Parviz; Jadidi-Niaragh, Farhad; Sotoodeh Jahromi, Abdolreza; Osterborg, Anders; Mellstedt, Håkan; Hojjat-Farsangi, Mohammad

    2016-06-01

    Targeted therapies have appeared as new treatment options for several disease types, including cancer and autoimmune disorders. Of several targets, tyrosine kinases (TKs) are among the most promising. Overexpression of TKs provides a target for novel therapeutic agents, including small molecule inhibitors of tyrosine kinases (TKI). Ibrutinib (PCI-32765) is a TKI of Bruton's tyrosine kinase (Btk), a key kinase of the B-cell receptor signaling pathway that plays a significant role in the proliferation, differentiation and survival of B cells. In addition to inhibitory effects, recent studies have shown that ibrutinib has multiple immunomodulatory effects. It binds covalently to IL-2 inducible tyrosine kinase (Itk) in T lymphocytes and suppresses the survival of T-helper (Th) 2 cells. This changes the balance of Th1/Th2 cells toward Th1 subset, which are the main immune cells targeting tumor cells. The dual activity of ibrutinib has paid a great attention and several studies are evaluating the anti-tumor and immunomodulatory effects in cancer, autoimmune disorders and infectious diseases. In this article we review the inhibitory and immunomodulatory effects of ibrutinib in B-cell malignancies, autoimmune diseases and infections, as well as the communication between the Ror1 receptor tyrosine kinase and BCR and effects of ibrutinib on this crosstalk. PMID:26362595

  17. Unintentional weakness of cancers: the MEK-ERK pathway as a double-edged sword.

    PubMed

    Suda, Kenichi; Mitsudomi, Tetsuya

    2013-10-01

    Recent advances in molecular targeted therapies have greatly improved treatment outcomes for cancers driven by oncogenic mutations. Despite initial and dramatic clinical responses, tumors eventually acquire resistance to these targeted therapies, showing flexible and diverse responses. Interestingly, cancer cells sometimes overadapt to the drug treatment environment, leading to a state in which cancer cells cannot survive without the drug. This interesting phenomenon (often called "drug dependency" or "drug addiction") is exemplified in preclinical acquired resistance models of BRAF-mutated melanoma treated with vemurafenib and EGFR-mutated lung cancer treated with EGFR tyrosine kinase inhibitors. A number of intriguing parallels in drug-addicted cancers became apparent in a comparison of the two models: (i) overexpression of driver oncogenes as causes of acquired resistance; (ii) overexpression of driver oncogenes causing MEK-ERK hyperactivation under drug-free conditions; (iii) hyperactivation of the MEK-ERK pathway as critical to this drug addiction phenomenon; (iv) ongoing dependence on the oncogenic driver; and (v) morphologic changes in resistant cells under drug-free conditions. This Perspective article not only focuses on this interesting and peculiar phenomenon but also discusses weapon strategies to exploit this unintentional weakness of cancers. PMID:23900694

  18. The Sensitivity of Precocious Child Writers: More Evidence of the Double-Edged Sword

    ERIC Educational Resources Information Center

    Edmunds, Alan L.; Edmunds, Gail

    2014-01-01

    This article provides further evidence of the often observed sensitive nature displayed by children who are gifted. It also addresses the positive and negative effects that this sensitivity can have on these individuals. Earlier, the authors explored this concept through an analysis of the works and life experiences of Geoffrey, aged 9, a prolific…

  19. Chinese Sex-Role Conceptions: A Double Edged Sword for Women.

    ERIC Educational Resources Information Center

    Korabik, Karen

    Although Chinese government policies officially support the equality of the sexes, stereotyped views about the nature of men and women often serve to perpetuate discrimination and to keep women in inferior positions. Women are often segregated into lower paying jobs because of stereotypical views about what is natural for women to do. Despite…

  20. Pattern Recognition Receptors and Cytokines in Mycobacterium tuberculosis Infection—The Double-Edged Sword?

    PubMed Central

    Hossain, Md. Murad; Norazmi, Mohd-Nor

    2013-01-01

    Tuberculosis, an infectious disease caused by Mycobacterium tuberculosis (Mtb), remains a major cause of human death worldwide. Innate immunity provides host defense against Mtb. Phagocytosis, characterized by recognition of Mtb by macrophages and dendritic cells (DCs), is the first step of the innate immune defense mechanism. The recognition of Mtb is mediated by pattern recognition receptors (PRRs), expressed on innate immune cells, including toll-like receptors (TLRs), complement receptors, nucleotide oligomerization domain like receptors, dendritic cell-specific intercellular adhesion molecule grabbing nonintegrin (DC-SIGN), mannose receptors, CD14 receptors, scavenger receptors, and FCγ receptors. Interaction of mycobacterial ligands with PRRs leads macrophages and DCs to secrete selected cytokines, which in turn induce interferon-γ- (IFNγ-) dominated immunity. IFNγ and other cytokines like tumor necrosis factor-α (TNFα) regulate mycobacterial growth, granuloma formation, and initiation of the adaptive immune response to Mtb and finally provide protection to the host. However, Mtb can evade destruction by antimicrobial defense mechanisms of the innate immune system as some components of the system may promote survival of the bacteria in these cells and facilitate pathogenesis. Thus, although innate immunity components generally play a protective role against Mtb, they may also facilitate Mtb survival. The involvement of selected PRRs and cytokines on these seemingly contradictory roles is discussed. PMID:24350246

  1. Teaching Mathematics by Comparison: Analog Visibility as a Double-Edged Sword

    ERIC Educational Resources Information Center

    Begolli, Kreshnik Nasi; Richland, Lindsey Engle

    2016-01-01

    Comparing multiple solutions to a single problem is an important mode for developing flexible mathematical thinking, yet instructionally leading this activity is challenging (Stein, Engle, Smith, & Hughes, 2008). We test 1 decision teachers must make after having students solve a problem: whether to only verbally discuss students' solutions or…

  2. Levodopa-induced plasticity: a double-edged sword in Parkinson's disease?

    PubMed Central

    Calabresi, Paolo; Ghiglieri, Veronica; Mazzocchetti, Petra; Corbelli, Ilenia; Picconi, Barbara

    2015-01-01

    The long-term replacement therapy with the dopamine (DA) precursor 3,4-dihydroxy-l-phenylalanine (L-DOPA) is a milestone in the treatment of Parkinson's disease (PD). Although this drug precursor can be metabolized into the active neurotransmitter DA throughout the brain, its therapeutic benefit is due to restoring extracellular DA levels within the dorsal striatum, which lacks endogenous DA as a consequence of the neurodegenerative process induced by the disease. In the early phases of PD, L-DOPA treatment is able to restore both long-term depression (LTD) and long-term potentiation (LTP), two major forms of corticostriatal synaptic plasticity that are altered by dopaminergic denervation. However, unlike physiological DA transmission, this therapeutic approach in the advanced phase of the disease leads to abnormal peaks of DA, non-synaptically released, which are supposed to trigger behavioural sensitization, namely L-DOPA-induced dyskinesia. This condition is characterized by a loss of synaptic depotentiation, an inability to reverse previously induced LTP. In the advanced stages of PD, L-DOPA can also induce non-motor fluctuations with cognitive dysfunction and neuropsychiatric symptoms such as compulsive behaviours and impulse control disorders. Although the mechanisms underlying the role of L-DOPA in both motor and behavioural symptoms are still incompletely understood, recent data from electrophysiological and imaging studies have increased our understanding of the function of the brain areas involved and of the mechanisms implicated in both therapeutic and adverse actions of L-DOPA in PD patients. PMID:26009763

  3. Spontaneous myopericarditis in a patient under dexamethasone: A double-edged sword?

    PubMed Central

    Tajdini, Masih

    2015-01-01

    A majority of acute pericarditis cases have some degree of myocarditis. Viruses are the common etiological factor of this disease. Corticosteroids are considered for treatment, especially in recurrent models of the disease. In this article, we report the case of a 47-year-old man with myopericarditis who was under daily intra-muscular dexamethasone injection for an unknown reason. This is a unique case of spontaneous myopericarditis under corticosteroid abuse that has not been reported previously. PMID:26557749

  4. Novel roles for protein disulphide isomerase in disease states: a double edged sword?

    PubMed Central

    Parakh, Sonam; Atkin, Julie D.

    2015-01-01

    Protein disulphide isomerase (PDI) is a multifunctional redox chaperone of the endoplasmic reticulum (ER). Since it was first discovered 40 years ago the functions ascribed to PDI have evolved significantly and recent studies have recognized its distinct functions, with adverse as well as protective effects in disease. Furthermore, post translational modifications of PDI abrogate its normal functional roles in specific disease states. This review focusses on recent studies that have identified novel functions for PDI relevant to specific diseases. PMID:26052512

  5. Dendritic Cells: A Double-Edged Sword in Immune Responses during Chagas Disease.

    PubMed

    Gil-Jaramillo, Natalia; Motta, Flávia N; Favali, Cecília B F; Bastos, Izabela M D; Santana, Jaime M

    2016-01-01

    Dendritic cells (DCs) are the most important member of the antigen presenting cells group due to their ability to recognize antigen at the infection site and their high specialized antigen internalization capacity. These cells have central role in connecting the innate and adaptive immune responses against Trypanosoma cruzi, the causative agent of Chagas disease. These first line defense cells modulate host immune response depending on type, maturation level, cytokine milieu and DC receptor involved in the interactions with T. cruzi, influencing the development of the disease clinic forms. Here, we present a review of DCs-T. cruzi interactions both in human and murine models, pointing out the parasite ability to manipulate DCs activity for the purpose of evading innate immune response and assuring its own survival and persistence. PMID:27471496

  6. A double-edged sword: Benefits and pitfalls of heterogeneous punishment in evolutionary inspection games

    NASA Astrophysics Data System (ADS)

    Perc, Matjaž; Szolnoki, Attila

    2015-06-01

    As a simple model for criminal behavior, the traditional two-strategy inspection game yields counterintuitive results that fail to describe empirical data. The latter shows that crime is often recurrent, and that crime rates do not respond linearly to mitigation attempts. A more apt model entails ordinary people who neither commit nor sanction crime as the third strategy besides the criminals and punishers. Since ordinary people free-ride on the sanctioning efforts of punishers, they may introduce cyclic dominance that enables the coexistence of all three competing strategies. In this setup ordinary individuals become the biggest impediment to crime abatement. We therefore also consider heterogeneous punisher strategies, which seek to reduce their investment into fighting crime in order to attain a more competitive payoff. We show that this diversity of punishment leads to an explosion of complexity in the system, where the benefits and pitfalls of criminal behavior are revealed in the most unexpected ways. Due to the raise and fall of different alliances no less than six consecutive phase transitions occur in dependence on solely the temptation to succumb to criminal behavior, leading the population from ordinary people-dominated across punisher-dominated to crime-dominated phases, yet always failing to abolish crime completely.

  7. "My Past Is a Double Edge Sword": Temporality and Reflexivity in Mature Learners

    ERIC Educational Resources Information Center

    Stevenson, Jacqueline; Clegg, Sue

    2013-01-01

    This paper discusses the ways in which mature students orientate themselves towards the future in making decisions to access higher education (HE). Their narratives connect their past, often difficult, educational and personal lives to their future aspirations and to their current experiences in further education (FE) and HE. The research was part…

  8. The Effects of α-Tocopherol on Bone: A Double-Edged Sword?

    PubMed Central

    Chin, Kok-Yong; Ima-Nirwana, Soelaiman

    2014-01-01

    Recent studies have found conflicting evidence on the role of α-tocopherol (αTF) on bone health. This nonsystematic review aimed to summarize the current evidence on the effects of αTF on bone health from cell culture, animal, and human studies in order to clarify the role of αTF on bone health. Our review found that αTF exerted beneficial, harmful or null effects on bone formation cells. Animal studies generally showed positive effects of αTF supplementation on bone in various models of osteoporosis. However, high-dose αTF was possibly detrimental to bone in normal animals. Human studies mostly demonstrated a positive relationship between αTF, as assessed using high performance liquid chromatography and/or dietary questionnaire, and bone health, as assessed using bone mineral density and/or fracture incidence. Three possible reasons high dosage of αTF can be detrimental to bone include its interference with Vitamin K function on bone, the blocking of the entry of other Vitamin E isomers beneficial to bone, and the role of αTF as a prooxidant. However, these adverse effects have not been shown in human studies. In conclusion, αTF may have a dual role in bone health, whereby in the appropriate doses it is beneficial but in high doses it may be harmful to bone. PMID:24727433

  9. A double-edged sword: Benefits and pitfalls of heterogeneous punishment in evolutionary inspection games

    PubMed Central

    Perc, Matjaž; Szolnoki, Attila

    2015-01-01

    As a simple model for criminal behavior, the traditional two-strategy inspection game yields counterintuitive results that fail to describe empirical data. The latter shows that crime is often recurrent, and that crime rates do not respond linearly to mitigation attempts. A more apt model entails ordinary people who neither commit nor sanction crime as the third strategy besides the criminals and punishers. Since ordinary people free-ride on the sanctioning efforts of punishers, they may introduce cyclic dominance that enables the coexistence of all three competing strategies. In this setup ordinary individuals become the biggest impediment to crime abatement. We therefore also consider heterogeneous punisher strategies, which seek to reduce their investment into fighting crime in order to attain a more competitive payoff. We show that this diversity of punishment leads to an explosion of complexity in the system, where the benefits and pitfalls of criminal behavior are revealed in the most unexpected ways. Due to the raise and fall of different alliances no less than six consecutive phase transitions occur in dependence on solely the temptation to succumb to criminal behavior, leading the population from ordinary people-dominated across punisher-dominated to crime-dominated phases, yet always failing to abolish crime completely. PMID:26046673

  10. Reading "the Word and the World": The Double-Edged Sword of Teaching Critical Literacy

    ERIC Educational Resources Information Center

    White, John Wesley

    2009-01-01

    White acknowledges that critical literacy is central to literacy instruction today, but warns that asking those untrained in critical literacy to "teach" critical literacy could have undesirable consequences. He suggests three potentially undesirable outcomes and offers advice for preventing them.

  11. A Double-Edged Sword: How Oncogenes and Tumor Suppressor Genes Can Contribute to Chromosomal Instability

    PubMed Central

    Orr, Bernardo; Compton, Duane A.

    2013-01-01

    Most solid tumors are characterized by abnormal chromosome numbers (aneuploidy) and karyotypic profiling has shown that the majority of these tumors are heterogeneous and chromosomally unstable. Chromosomal instability (CIN) is defined as persistent mis-segregation of whole chromosomes and is caused by defects during mitosis. Large-scale genome sequencing has failed to reveal frequent mutations of genes encoding proteins involved in mitosis. On the contrary, sequencing has revealed that most mutated genes in cancer fall into a limited number of core oncogenic signaling pathways that regulate the cell cycle, cell growth, and apoptosis. This led to the notion that the induction of oncogenic signaling is a separate event from the loss of mitotic fidelity, but a growing body of evidence suggests that oncogenic signaling can deregulate cell cycle progression, growth, and differentiation as well as cause CIN. These new results indicate that the induction of CIN can no longer be considered separately from the cancer-associated driver mutations. Here we review the primary causes of CIN in mitosis and discuss how the oncogenic activation of key signal transduction pathways contributes to the induction of CIN. PMID:23825799

  12. Inflammation and Inflammatory Cells in Myocardial Infarction and Reperfusion Injury: A Double-Edged Sword

    PubMed Central

    Liu, Jiaqi; Wang, Haijuan; Li, Jun

    2016-01-01

    Myocardial infarction (MI) is the most common cause of cardiac injury, and subsequent reperfusion further enhances the activation of innate and adaptive immune responses and cell death programs. Therefore, inflammation and inflammatory cell infiltration are the hallmarks of MI and reperfusion injury. Ischemic cardiac injury activates the innate immune response via toll-like receptors and upregulates chemokine and cytokine expressions in the infarcted heart. The recruitment of inflammatory cells is a dynamic and superbly orchestrated process. Sequential infiltration of the injured myocardium with neutrophils, monocytes and their descendant macrophages, dendritic cells, and lymphocytes contributes to the initiation and resolution of inflammation, infarct healing, angiogenesis, and ventricular remodeling. Both detrimental effects and a beneficial role in the pathophysiology of MI and reperfusion injury may be attributed to the subset heterogeneity and functional diversity of these inflammatory cells. PMID:27279755

  13. Effect of the Hydrogen Bond in Photoinduced Water Dissociation: A Double-Edged Sword.

    PubMed

    Yang, Wenshao; Wei, Dong; Jin, Xianchi; Xu, Chenbiao; Geng, Zhenhua; Guo, Qing; Ma, Zhibo; Dai, Dongxu; Fan, Hongjun; Yang, Xueming

    2016-02-18

    Photoinduced water dissociation on rutile-TiO2 was investigated using various methods. Experimental results reveal that the water dissociation occurs via transferring an H atom to a bridge bonded oxygen site and ejecting an OH radical to the gas phase during irradiation. The reaction is strongly suppressed as the water coverage increases. Further scanning tunneling microscopy study demonstrates that hydrogen bonds between water molecules have a dramatic effect on the reaction. Interestingly, a single hydrogen bond in water dimer enhances the water dissociation reaction, while one-dimensional hydrogen bonds in water chains inhibit the reaction. Density functional theory calculations indicate that the effect of hydrogen bonds on the OH dissociation energy is likely the origin of this remarkable behavior. The results suggest that avoiding a strong hydrogen bond network between water molecules is crucial for water splitting. PMID:26810945

  14. Iron supplementation during human immunodeficiency virus infection: a double-edged sword?

    PubMed

    Clark, T D; Semba, R D

    2001-10-01

    Although iron supplementation is considered beneficial for groups at risk for anemia, concern has been raised that it could be harmful during human immunodeficiency virus (HIV) infection. Studies suggest: (1) faster HIV disease progression in thalassemia major patients receiving inadequate doses of iron-chelating drug; (2) higher mortality among patients receiving iron supplementation with dapsone compared with aerosolized pentamidine for prophylaxis against Pneumocytis carinii pneumonia; (3) higher iron stores and mortality among patients with haptoglobin Hp 2-2 phenotype; and (4) shorter survival among patients with high bone marrow iron deposition. These studies largely involved men in developed countries. Among HIV-infected pregnant women in Africa with a high prevalence of iron deficiency, no relationship was found between indicators of iron status and HIV disease severity. The available data do not contraindicate the current practice of iron supplementation in developing countries where there is a high prevalence of both HIV infection and iron deficiency. PMID:11601873

  15. Autonomy, Attachment and Psychosocial Adjustment during Adolescence: A Double-Edged Sword.

    ERIC Educational Resources Information Center

    Noom, Marc J.; Dekovic, Maja; Meeus, Wim H. J.

    1999-01-01

    Examines the assumption that a high level of autonomy within a context of attachment provides the best constellation for psychosocial adjustments with adolescents (N=400). Results show that attitudinal, emotional, and functional autonomy were connected with attachment to father, mother, and peers to predict indices of psychosocial adjustment:…

  16. The double-edged sword: does biomechanism increase or decrease judges' sentencing of psychopaths?

    PubMed

    Aspinwall, Lisa G; Brown, Teneille R; Tabery, James

    2012-08-17

    We tested whether expert testimony concerning a biomechanism of psychopathy increases or decreases punishment. In a nationwide experiment, U.S. state trial judges (N = 181) read a hypothetical case (based on an actual case) where the convict was diagnosed with psychopathy. Evidence presented at sentencing in support of a biomechanical cause of the convict's psychopathy significantly reduced the extent to which psychopathy was rated as aggravating and significantly reduced sentencing (from 13.93 years to 12.83 years). Content analysis of judges' reasoning indicated that even though the majority of judges listed aggravating factors (86.7%), the biomechanical evidence increased the proportion of judges listing mitigating factors (from 29.7 to 47.8%). Our results contribute to the literature on how biological explanations of behavior figure into theories of culpability and punishment. PMID:22904010

  17. Wnt/β-catenin signaling in kidney injury and repair: a double-edged sword

    PubMed Central

    Zhou, Dong; Tan, Roderick J.; Fu, Haiyan; Liu, Youhua

    2015-01-01

    The Wnt/β-catenin signaling cascade is an evolutionarily conserved, highly complex pathway that is known to be involved in kidney injury and repair after a wide variety of insults. While the kidney displays an impressive ability to repair and recover after injury, these repair mechanisms can be overwhelmed, leading to maladaptive responses and eventual development of chronic kidney disease (CKD). Emerging evidence demonstrates that Wnt/β-catenin signaling possesses dual roles in promoting repair/regeneration or facilitating progression to CKD after acute kidney injury (AKI), depending on the magnitude and duration of its activation. In this review, we summarize the expression, intracellular modification, and secretion of Wnt family proteins and their regulation in a variety of kidney diseases. We also explore our current understanding of the potential mechanisms by which transient Wnt/β-catenin activation positively regulates adaptive responses of the kidney after AKI, and discuss how sustained activation of this signaling triggers maladaptive responses and causes destructive outcomes. A better understanding of these mechanisms may offer important opportunities for designing targeted therapy to promote adaptive kidney repair/recovery and prevent progression to CKD in patients. PMID:26692289

  18. The Double-Edged Sword: Conserved Functions of Extracellular Hsp90 in Wound Healing and Cancer

    PubMed Central

    Hance, Michael W.; Nolan, Krystal D.; Isaacs, Jennifer S.

    2014-01-01

    Heat shock proteins (Hsps) represent a diverse group of chaperones that play a vital role in the protection of cells against numerous environmental stresses. Although our understanding of chaperone biology has deepened over the last decade, the “atypical” extracellular functions of Hsps have remained somewhat enigmatic and comparatively understudied. The heat shock protein 90 (Hsp90) chaperone is a prototypic model for an Hsp family member exhibiting a duality of intracellular and extracellular functions. Intracellular Hsp90 is best known as a master regulator of protein folding. Cancers are particularly adept at exploiting this function of Hsp90, providing the impetus for the robust clinical development of small molecule Hsp90 inhibitors. However, in addition to its maintenance of protein homeostasis, Hsp90 has also been identified as an extracellular protein. Although early reports ascribed immunoregulatory functions to extracellular Hsp90 (eHsp90), recent studies have illuminated expanded functions for eHsp90 in wound healing and cancer. While the intended physiological role of eHsp90 remains enigmatic, its evolutionarily conserved functions in wound healing are easily co-opted during malignancy, a pathology sharing many properties of wounded tissue. This review will highlight the emerging functions of eHsp90 and shed light on its seemingly dichotomous roles as a benevolent facilitator of wound healing and as a sinister effector of tumor progression. PMID:24805867

  19. Erythropoietin 2nd cerebral protection after acute injuries: a double-edged sword?

    PubMed

    Velly, L; Pellegrini, L; Guillet, B; Bruder, N; Pisano, P

    2010-12-01

    Over the past 15 years, a large body of evidence has revealed that the cytokine erythropoietin exhibits non-erythropoietic functions, especially tissue-protective effects. The discovery of EPO and its receptors in the central nervous system and the evidence that EPO is made locally in response to injury as a protective factor in the brain have raised the possibility that recombinant human EPO (rhEPO) could be administered as a cytoprotective agent after acute brain injuries. This review highlights the potential applications of rhEPO as a neuroprotectant in experimental and clinical settings such as ischemia, traumatic brain injury, and subarachnoid and intracerebral hemorrhage. In preclinical studies, EPO prevented apoptosis, inflammation, and oxidative stress induced by injury and exhibited strong neuroprotective and neurorestorative properties. EPO stimulates vascular repair by facilitating endothelial progenitor cell migration into the brain and neovascularisation, and it promotes neurogenesis. In humans, small clinical trials have shown promising results but large prospective randomized studies failed to demonstrate a benefit of EPO for brain protection and showed unwanted side effects, especially thrombotic complications. Recently, regions have been identified within the EPO molecule that mediate tissue protection, allowing the development of non-erythropoietic EPO variants for neuroprotection conceptually devoid of side effects. The efficacy and the safety profile of these new compounds are still to be demonstrated to obtain, in patients, the benefits observed in experimental studies. PMID:20732352

  20. Microglia-blood vessel interactions: a double-edged sword in brain pathologies.

    PubMed

    Dudvarski Stankovic, Nevenka; Teodorczyk, Marcin; Ploen, Robert; Zipp, Frauke; Schmidt, Mirko H H

    2016-03-01

    Microglia are long-living resident immune cells of the brain, which secure a stable chemical and physical microenvironment necessary for the proper functioning of the central nervous system (CNS). These highly dynamic cells continuously scan their environment for pathogens and possess the ability to react to damage-induced signals in order to protect the brain. Microglia, together with endothelial cells (ECs), pericytes and astrocytes, form the functional blood-brain barrier (BBB), a specialized endothelial structure that selectively separates the sensitive brain parenchyma from blood circulation. Microglia are in bidirectional and permanent communication with ECs and their perivascular localization enables them to survey the influx of blood-borne components into the CNS. Furthermore, they may stimulate the opening of the BBB, extravasation of leukocytes and angiogenesis. However, microglia functioning requires tight control as their dysregulation is implicated in the initiation and progression of numerous neurological diseases. Disruption of the BBB, changes in blood flow, introduction of pathogens in the sensitive CNS niche, insufficient nutrient supply, and abnormal secretion of cytokines or expression of endothelial receptors are reported to prime and attract microglia. Such reactive microglia have been reported to even escalate the damage of the brain parenchyma as is the case in ischemic injuries, brain tumors, multiple sclerosis, Alzheimer's and Parkinson's disease. In this review, we present the current state of the art of the causes and mechanisms of pathological interactions between microglia and blood vessels and explore the possibilities of targeting those dysfunctional interactions for the development of future therapeutics. PMID:26711460

  1. Intravenous Lignocaine to Blunt Extubation Responses: A Double-Edged Sword.

    PubMed

    Haldar, Rudrashish; Dubey, Madhulika; Rastogi, Amit; Singh, Prabhat K

    2016-01-01

    Extubation after general anesthetic procedures is often accompanied by transient undesirable responses such as hypertension, tachycardia, coughing, bucking, and raised intracranial and intraocular pressures. In neurosurgical procedures, they need to be stringently controlled to prevent the rise in cerebral blood flow, increase in intracranial pressure, and intracranial bleeding. Intravenous (IV) lignocaine (1-1.5 mg/kg) administration is one such method to blunt extubation responses. We describe a case where IV lignocaine was administered within the recommended doses to inhibit the extubation response, but the same resulted in generalized convulsions because of the clinical and physiological status of the patient at that point of time. Intravenous lignocaine administered to obtund extubation responses can itself manifest in toxic reactions depending on the preexisting clinical and physiological state of the patients. Thus, extreme caution and vigilance is to be maintained whenever IV local anesthetics are used for such purposes. PMID:25807045

  2. Cognitive Load and Classroom Teaching: The Double-Edged Sword of Automaticity

    ERIC Educational Resources Information Center

    Feldon, David F.

    2007-01-01

    Research in the development of teacher cognition and teaching performance in K-12 classrooms has identified consistent challenges and patterns of behavior that are congruent with the predictions of dual-process models of cognition. However, cognitive models of information processing are not often used to synthesize these results. This article…

  3. "A Double-Edged Sword": College Student Perceptions of Required High School Service-Learning

    ERIC Educational Resources Information Center

    Jones, Susan R.; Segar, Thomas C.; Gasiorski, Anna L.

    2008-01-01

    This article presents the findings from a narrative inquiry exploring the perceived outcomes associated with a high school service-learning graduation requirement from a diverse group of college students. In particular, we were interested in participants' stories related to their experiences meeting the requirement, the meaning they made of the…

  4. The Double-Edged Sword of Pedagogy: Instruction Limits Spontaneous Exploration and Discovery

    ERIC Educational Resources Information Center

    Bonawitz, Elizabeth; Shafto, Patrick; Gweon, Hyowon; Goodman, Noah D.; Spelke, Elizabeth; Schulz, Laura

    2011-01-01

    Motivated by computational analyses, we look at how teaching affects exploration and discovery. In Experiment 1, we investigated children's exploratory play after an adult pedagogically demonstrated a function of a toy, after an interrupted pedagogical demonstration, after a naive adult demonstrated the function, and at baseline. Preschoolers in…

  5. Role of angiopoietin-2 in infection - A double-edged sword?

    PubMed

    Thamm, Kristina; David, Sascha

    2016-07-01

    The endothelial angiopoietin (Angpt)/Tie2 ligand receptor system maintains vascular quiescence and modulates the response to injury. Angpt-1 is considered the natural Tie2 agonist and receptor ligation leads to its phosphorylation inducing various protective downstream pathways. The natural antagonist - Angpt-2 - appears to inhibit these protective effects. In sepsis, the balance between both ligands is shifted in favor for Angpt-2 and the vasculature is highly dysfunctional, activated and leaky. Circulating levels of Angpt-2 strongly predict mortality in septic patients. Consistently, experimental strategies that target Angpt-2 (e.g. antibody, RNAi, etc.) can protect the vascular barrier and improve survival. However, in vitro is has also been shown that Angpt-2 can act as a dose-dependent Tie2 agonist/antagonist. Based on this, people have wondered if Angpt-2 is per se injurious or if it might have protective effects dependent on the scenario. A recent paper by Safioleas and colleagues showed survival benefits after a therapeutic injection of recombinant Angpt-2 in experimental pyelonephritis. Here, we discuss their counter-intuitive but interesting findings and put them into a global context with respect to the existent literature in the angiopoietin/Tie2 sepsis field. PMID:27038015

  6. Allocating More Experienced Teachers to Leadership Positions in Schools: A Double-Edged Sword?

    ERIC Educational Resources Information Center

    Camburn, Eric M.

    2009-01-01

    This article presents a critical discussion of the implications of allocating the most experienced and skilled teachers in schools to teacher leadership positions. Placing such teachers in leadership positions supports school improvement initiatives, but it can also pull valuable teaching resources from the classroom. The article examines this…

  7. Double-edged sword of radiotherapy: a cause of secondary angiosarcoma after breast conservation therapy.

    PubMed

    Iqbal, Fahad Mujtaba; Ahmed, Balen; Vidya, Raghavan

    2016-01-01

    Angiosarcomas are rare and aggressive malignant tumours of vascular or endothelial origin that can originate in the breast. They can be classified as primary or secondary, with the latter most commonly due to postoperative radiotherapy as part of breast conservation therapy (wide local excision and adjuvant radiotherapy) for breast cancer. We report a case of postirradiation secondary angiosarcoma in a 56-year-old woman, alongside a review of the current literature, to inform clinicians of its clinical presentation and characteristics as a high index of clinical suspicion is required for an accurate diagnosis. PMID:27113794

  8. The Double-edged Sword of Pedagogy: Instruction limits spontaneous exploration and discovery

    PubMed Central

    Shafto, Patrick; Gweon, Hyowon; Goodman, Noah D.; Spelke, Elizabeth; Schulz, Laura

    2012-01-01

    Motivated by computational analyses, we look at how teaching affects exploration and discovery. In Experiment 1, we investigated children’s exploratory play after an adult pedagogically demonstrated a function of a toy, after an interrupted pedagogical demonstration, after a naïve adult demonstrated the function, and at baseline. Preschoolers in the pedagogical condition focused almost exclusively on the target function; by contrast, children in the other conditions explored broadly. In Experiment 2, we show that children restrict their exploration both after direct instruction to themselves and after overhearing direct instruction given to another child; they do not show this constraint after observing direct instruction given to an adult or after observing a non-pedagogical intentional action. We discuss these findings as the result of rational inductive biases. In pedagogical contexts, a teacher’s failure to provide evidence for additional functions provides evidence for their absence; such contexts generalize from child to child (because children are likely to have comparable states of knowledge) but not from adult to child. Thus, pedagogy promotes efficient learning but at a cost: children are less likely to perform potentially irrelevant actions but also less likely to discover novel information. PMID:21216395

  9. Alendronate, a double-edged sword acting in the mevalonate pathway

    PubMed Central

    TRICARICO, PAOLA MAURA; GIRARDELLI, MARTINA; KLEINER, GIULIO; KNOWLES, ALESSANDRA; VALENCIC, ERICA; CROVELLA, SERGIO; MARCUZZI, ANNALISA

    2015-01-01

    Aminobisphosphonate aledronate is a compound commonly used clinically for the treatment of osteoporosis and other bone diseases, as a result of it preventing bone resorption. However, in previous years it has also been used to obtain cellular and animal models of a rare genetic disorder termed Mevalonate Kinase Deficiency (MKD). MKD is caused by mutations affecting the mevalonate kinase enzyme, in the cholesterol pathway and alendronate can be used to biochemically mimic the genetic defect as it inhibits farnesyl pyrophosphate synthase in the same pathway. Despite evidence in favor of the inhibition exerted on the mevalonate pathway, there is at least one clinical case of MKD in which alendronate improved not only skeletal and bone fractures, as expected, but also MKD clinical features. Based on this finding, the present study assessed the anti-inflammatory properties of this aminobisphosphonate in vitro. No anti-inflammatory effects of alendronate were observed in the in vitro experiments. Since MKD lacks specific treatments, these results may assist scientists and physicians in making the decision as to the most suitable choice of therapeutic compounds for this neglected disease. PMID:26096667

  10. Protecting chemistry inventions: the double-edged sword of being an unpredictable art.

    PubMed

    Tostmann, Holger

    2015-04-01

    Recent decisions by the highest courts in the US in regard to written description and enablement as well as parallel restrictions previously established in Europe emphasize that applicants in the fields of chemistry/pharma/life sciences should strive to include as many examples, data, and guidance about how to extrapolate from the example(s) in the description. This holds in particular whenever a broad genus and/or functional features is/are to be protected. It is important to keep in mind that these data and this guidance must be disclosed in the application at the time of filing. Data collected at a later stage can only be used to further support data and evidence already present in the application as filed. PMID:25941548

  11. Dendritic Cells: A Double-Edged Sword in Immune Responses during Chagas Disease

    PubMed Central

    Gil-Jaramillo, Natalia; Motta, Flávia N.; Favali, Cecília B. F.; Bastos, Izabela M. D.; Santana, Jaime M.

    2016-01-01

    Dendritic cells (DCs) are the most important member of the antigen presenting cells group due to their ability to recognize antigen at the infection site and their high specialized antigen internalization capacity. These cells have central role in connecting the innate and adaptive immune responses against Trypanosoma cruzi, the causative agent of Chagas disease. These first line defense cells modulate host immune response depending on type, maturation level, cytokine milieu and DC receptor involved in the interactions with T. cruzi, influencing the development of the disease clinic forms. Here, we present a review of DCs–T. cruzi interactions both in human and murine models, pointing out the parasite ability to manipulate DCs activity for the purpose of evading innate immune response and assuring its own survival and persistence. PMID:27471496

  12. The DLK signalling pathway--a double-edged sword in neural development and regeneration.

    PubMed

    Tedeschi, Andrea; Bradke, Frank

    2013-07-01

    Dual leucine zipper kinase (DLK), a mitogen-activated protein kinase kinase kinase, controls axon growth, apoptosis and neuron degeneration during neural development, as well as neurodegeneration after various insults to the adult nervous system. Interestingly, recent studies have also highlighted a role of DLK in promoting axon regeneration in diverse model systems. Invertebrates and vertebrates, cold- and warm-blooded animals, as well as central and peripheral mammalian nervous systems all differ in their ability to regenerate injured axons. Here, we discuss how DLK-dependent signalling regulates apparently contradictory functions during neural development and regeneration in different species. In addition, we outline strategies to fine-tune DLK function, either alone or together with other approaches, to promote axon regeneration in the adult mammalian central nervous system. PMID:23681442

  13. Increasing tomato fruit quality by enhancing fruit chloroplast function. A double-edged sword?

    PubMed

    Cocaliadis, Maria Florencia; Fernández-Muñoz, Rafael; Pons, Clara; Orzaez, Diego; Granell, Antonio

    2014-08-01

    Fruits are generally regarded as photosynthate sinks as they rely on energy provided by sugars transported from leaves to carry out the highly demanding processes of development and ripening; eventually these imported photosynthates also contribute to the fruit organoleptic properties. Three recent reports have revealed, however, that transcriptional factors enhancing chloroplast development in fruit may result in higher contents not only of tomato fruit-specialized metabolites but also of sugars. In addition to suggesting new ways to improve fruit quality by fortifying fruit chloroplasts and plastids, these results prompted us to re-evaluate the importance of the contribution of chloroplasts/photosynthesis to fruit development and ripening. PMID:24723405

  14. Temperate bacterial viruses as double-edged swords in bacterial warfare.

    PubMed

    Gama, João Alves; Reis, Ana Maria; Domingues, Iolanda; Mendes-Soares, Helena; Matos, Ana Margarida; Dionisio, Francisco

    2013-01-01

    It has been argued that bacterial cells may use their temperate viruses as biological weapons. For instance, a few bacterial cells among a population of lysogenic cells could release the virus and kill susceptible non-lysogenic competitors, while their clone mates would be immune. Because viruses replicate inside their victims upon infection, this process would amplify their number in the arena. Sometimes, however, temperate viruses spare recipient cells from death by establishing themselves in a dormant state inside cells. This phenomenon is called lysogenization and, for some viruses such as the λ virus, the probability of lysogenization increases with the multiplicity of infection. Therefore, the amplification of viruses leads to conflicting predictions about the efficacy of temperate viruses as biological weapons: amplification can increase the relative advantage of clone mates of lysogens but also the likelihood of saving susceptible cells from death, because the probability of lysogenization is higher. To test the usefulness of viruses as biological weapons, we performed competition experiments between lysogenic Escherichia coli cells carrying the λ virus and susceptible λ-free E. coli cells, either in a structured or unstructured habitat. In structured and sometimes in unstructured habitats, the λ virus qualitatively behaved as a "replicating toxin". However, such toxic effect of λ viruses ceased after a few days of competition. This was due to the fact that many of initially susceptible cells became lysogenic. Massive lysogenization of susceptible cells occurred precisely under the conditions where the amplification of the virus was substantial. From then on, these cells and their descendants became immune to the λ virus. In conclusion, if at short term bacterial cells may use temperate viruses as biological weapons, after a few days only the classical view of temperate bacterial viruses as parasitic agents prevails. PMID:23536852

  15. MG53 is a double-edged sword for human diseases.

    PubMed

    Zhang, Yan; Wu, Hong-Kun; Lv, Feng-Xiang; Xiao, Rui-Ping

    2016-08-25

    Mitsugumin 53 (MG53), also named Trim72, is a multi-functional TRIM-family protein, which is abundantly expressed in cardiac and skeletal muscle. It has been shown that MG53 not only plays important physiological roles but also acts as a crucial pathogenic factor of various diseases. First, MG53 preserves cardiac and skeletal muscle integrity via facilitating plasma membrane repair. Second, MG53 is essentially involved in cardiac ischemic preconditioning and postconditioning by activating PI3K-Akt-GSK3β and ERK1/2 cell survival signaling pathways. Moreover, systemic delivery of recombinant MG53 is able to abolish mechanic or ischemia-reperfusion (I/R)-induced injury of multiple organs, including heart, skeletal muscle, lung, kidney and skin. Importantly, MG53 acts as an E3 ligase to mediate the degradation of insulin receptor and insulin receptor substrate-1, and subsequently induces insulin resistance and metabolic diseases such as type-2 diabetes and its cardiovascular complications. In addition, MG53 negatively regulates myogenesis. As a potential therapeutic target of human diseases, multiple facets of MG53 biological function and mechanisms of action should be taken into the consideration to maximize its beneficial effects and minimize potential side-effects. Here in this review, we intend to comprehensively summarize the current progresses on the biological functions of MG53, focusing on its clinical value as a therapeutic target. PMID:27546510

  16. Protecting Chemistry Inventions: The Double-Edged Sword of Being an Unpredictable Art

    PubMed Central

    2015-01-01

    Recent decisions by the highest courts in the US in regard to written description and enablement as well as parallel restrictions previously established in Europe emphasize that applicants in the fields of chemistry/pharma/life sciences should strive to include as many examples, data, and guidance about how to extrapolate from the example(s) in the description. This holds in particular whenever a broad genus and/or functional features is/are to be protected. It is important to keep in mind that these data and this guidance must be disclosed in the application at the time of filing. Data collected at a later stage can only be used to further support data and evidence already present in the application as filed. PMID:25941548

  17. Stabilizing versus Destabilizing the Microtubules: A Double-Edge Sword for an Effective Cancer Treatment Option?

    PubMed Central

    Fanale, Daniele; Bronte, Giuseppe; Passiglia, Francesco; Calò, Valentina; Castiglia, Marta; Di Piazza, Florinda; Barraco, Nadia; Cangemi, Antonina; Catarella, Maria Teresa; Insalaco, Lavinia; Listì, Angela; Maragliano, Rossella; Massihnia, Daniela; Perez, Alessandro; Toia, Francesca; Cicero, Giuseppe; Bazan, Viviana

    2015-01-01

    Microtubules are dynamic and structural cellular components involved in several cell functions, including cell shape, motility, and intracellular trafficking. In proliferating cells, they are essential components in the division process through the formation of the mitotic spindle. As a result of these functions, tubulin and microtubules are targets for anticancer agents. Microtubule-targeting agents can be divided into two groups: microtubule-stabilizing, and microtubule-destabilizing agents. The former bind to the tubulin polymer and stabilize microtubules, while the latter bind to the tubulin dimers and destabilize microtubules. Alteration of tubulin-microtubule equilibrium determines the disruption of the mitotic spindle, halting the cell cycle at the metaphase-anaphase transition and, eventually, resulting in cell death. Clinical application of earlier microtubule inhibitors, however, unfortunately showed several limits, such as neurological and bone marrow toxicity and the emergence of drug-resistant tumor cells. Here we review several natural and synthetic microtubule-targeting agents, which showed antitumor activity and increased efficacy in comparison to traditional drugs in various preclinical and clinical studies. Cryptophycins, combretastatins, ombrabulin, soblidotin, D-24851, epothilones and discodermolide were used in clinical trials. Some of them showed antiangiogenic and antivascular activity and others showed the ability to overcome multidrug resistance, supporting their possible use in chemotherapy. PMID:26484003

  18. Clinical utilization of chemokines to combat cancer: the double-edged sword

    PubMed Central

    Dell’Agnola, Chiara; Biragyn, Arya

    2008-01-01

    Chemokines are a small group of related chemoattractant peptides that play an essential role in the homeostatic maintenance of the immune system. They control the recruitment of cells needed for the induction and activation of innate and adaptive immune responses. However, tumors also utilize chemokines to actively progress and evade immunosurveillance. In fact, chemokines are involved directly or indirectly in almost every aspect of tumorigenesis. They mediate survival and metastatic spread of tumors, promote new blood vessel formation (neovascularization) and induce an immunosuppressive microenvironment via recruitment of immunosuppressive cells. As a result, a number of therapeutic strategies have been proposed to target almost every step of the chemokine/chemokine receptor involvement in tumors. Yet, despite occasional success stories, most of them appear to be ineffective or impractical, presumably due to ‘nonspecific’ harm of cells needed for the elimination of tumor escapees and maintenance of immunological memory. The strategy would only be effective if it also promoted antitumor adaptive immune responses capable of combating a residual disease and tumor relapse. PMID:17408375

  19. The Double-Edged Sword of "Disaster Volunteerism": A Study of New Orleans Rebirth Movement Participants

    ERIC Educational Resources Information Center

    Heldman, Caroline; Israel-Trummel, Mackenzie

    2012-01-01

    We examine the political and personal effects of disaster volunteerism with participants of the New Orleans Rebirth Movement (NORM) using four waves of pre- and postsurveys and qualitative analysis of participant journals. Significant increases are found in internal political efficacy, desire to be active in politics, and value placed on social…

  20. Education Policy Reform in Sri Lanka: The Double-Edged Sword of Political Will

    ERIC Educational Resources Information Center

    Little, Angela W.

    2011-01-01

    In 1997, the Government of Sri Lanka launched a comprehensive set of education reforms designed to promote equitable access to basic education and improvements in learning outcomes. The package of reforms arose as a political response to widespread youth unrest in the late 1980s and attracted considerable "political will", a vague but much vaunted…

  1. The effects of α-tocopherol on bone: a double-edged sword?

    PubMed

    Chin, Kok-Yong; Ima-Nirwana, Soelaiman

    2014-04-01

    Recent studies have found conflicting evidence on the role of α-tocopherol (αTF) on bone health. This nonsystematic review aimed to summarize the current evidence on the effects of αTF on bone health from cell culture, animal, and human studies in order to clarify the role of αTF on bone health. Our review found that αTF exerted beneficial, harmful or null effects on bone formation cells. Animal studies generally showed positive effects of αTF supplementation on bone in various models of osteoporosis. However, high-dose αTF was possibly detrimental to bone in normal animals. Human studies mostly demonstrated a positive relationship between αTF, as assessed using high performance liquid chromatography and/or dietary questionnaire, and bone health, as assessed using bone mineral density and/or fracture incidence. Three possible reasons high dosage of αTF can be detrimental to bone include its interference with Vitamin K function on bone, the blocking of the entry of other Vitamin E isomers beneficial to bone, and the role of αTF as a prooxidant. However, these adverse effects have not been shown in human studies. In conclusion, αTF may have a dual role in bone health, whereby in the appropriate doses it is beneficial but in high doses it may be harmful to bone. PMID:24727433

  2. A Double-Edged Sword: Assessing the Impact of Tuition Discounting.

    ERIC Educational Resources Information Center

    Hubbell, Loren W. Loomis; Rush, Sean C.

    1991-01-01

    A discussion of the interrelationships between college tuition pricing, family resources, externally funded financial aid, and institutionally funded financial aid suggests that, as the range of tuition levels broadens, institutions must focus more closely on net tuition income in their forecasting or face erosion of revenues. (MSE)

  3. Temperate Bacterial Viruses as Double-Edged Swords in Bacterial Warfare

    PubMed Central

    Gama, João Alves; Reis, Ana Maria; Domingues, Iolanda; Mendes-Soares, Helena; Matos, Ana Margarida; Dionisio, Francisco

    2013-01-01

    It has been argued that bacterial cells may use their temperate viruses as biological weapons. For instance, a few bacterial cells among a population of lysogenic cells could release the virus and kill susceptible non-lysogenic competitors, while their clone mates would be immune. Because viruses replicate inside their victims upon infection, this process would amplify their number in the arena. Sometimes, however, temperate viruses spare recipient cells from death by establishing themselves in a dormant state inside cells. This phenomenon is called lysogenization and, for some viruses such as the λ virus, the probability of lysogenization increases with the multiplicity of infection. Therefore, the amplification of viruses leads to conflicting predictions about the efficacy of temperate viruses as biological weapons: amplification can increase the relative advantage of clone mates of lysogens but also the likelihood of saving susceptible cells from death, because the probability of lysogenization is higher. To test the usefulness of viruses as biological weapons, we performed competition experiments between lysogenic Escherichia coli cells carrying the λ virus and susceptible λ-free E. coli cells, either in a structured or unstructured habitat. In structured and sometimes in unstructured habitats, the λ virus qualitatively behaved as a “replicating toxin”. However, such toxic effect of λ viruses ceased after a few days of competition. This was due to the fact that many of initially susceptible cells became lysogenic. Massive lysogenization of susceptible cells occurred precisely under the conditions where the amplification of the virus was substantial. From then on, these cells and their descendants became immune to the λ virus. In conclusion, if at short term bacterial cells may use temperate viruses as biological weapons, after a few days only the classical view of temperate bacterial viruses as parasitic agents prevails. PMID:23536852

  4. Neutrophil extracellular traps (NETs): Double-edged swords of innate immunity1

    PubMed Central

    Kaplan, Mariana J.; Radic, Marko

    2012-01-01

    Spectacular images of neutrophils ejecting nuclear chromatin and bactericidal proteins, in response to microbes, were first reported in 2004. As externalized chromatin could entangle bacteria, these structures were named neutrophil extracellular traps (NETs). Subsequent studies identified microorganisms and sterile conditions that stimulate NETs, and additional cell types that release extracellular chromatin. NETs’ release is the most dramatic stage in a cell death process called NETosis. Experimental evidence suggests that NETs participate in pathogenesis of autoimmune and inflammatory disorders, with proposed involvement in glomerulonephritis, chronic lung disease, sepsis and vascular disorders. Exaggerated NETosis or diminished NET clearance likely increases risk of autoreactivity to NET components. The biological significance of NETs is just beginning to be explored. A more complete integration of NETosis within immunology and pathophysiology will require better understanding of NET properties associated with specific disease states and microbial infections. This may lead to the identification of important therapeutic targets. PMID:22956760

  5. Detail of double pole utility tower at the edge of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of double pole utility tower at the edge of the mesa. National Old Trails Road right-of-way crosses in foreground over a dry laid basaltic rock retaining wall. View south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  6. Immune Mechanism: A ‘Double-Edged Sword’

    PubMed Central

    Musa, Mustaffa

    2013-01-01

    Immunology has now developed into an independent discipline in medicine which covers not only germ infection which is related to immunity solely but also covers a lot of non-infectious diseases such as autoimmune disease, allergies, and others. Therefore, “The Immune Mechanism: “A Double-Edged Sword” means that the immune mechanism (consisted of antibody mediated mechanism and T cell mediated mechanism), just like one edge playing the role of giving benefit (immunity) as it destroys the agent of infection, and another one can be detrimental as it will cause tissue/cell damages and then give rise to immune diseases (immunopathology). Now, the prevalence of these immune diseases is on the rise and has become a new challenge to our country towards developed country in 2020. Therefore, we have to make ample preparation (laboratory facilities/services, main power, and research) from now on in order to face the problems and challenges. PMID:23966827

  7. Double-Edge Molecular Technique for Doppler Lidar Wind Measurement

    NASA Technical Reports Server (NTRS)

    Flesia, Cristina; Korb, C. Laurence

    1998-01-01

    The double-edge lidar technique for measuring the wind using molecular backscatter is described. Two high spectral resolution edge filters are located in the wings of the Rayleigh-Brillouin profile. This doubles the signal change per unit Doppler shift, the sensitivity, and gives nearly a factor of two improvement in measurement accuracy. The use of a crossover region is described where the sensitivity of a molecular and aerosol-based measurement are equal. This desensitizes the molecular measurement to the effects of aerosol scattering over a frequency range of +/- 100 m/s. We give methods for correcting for short-term frequency jitter and drift using a laser reference frequency measurement and methods for long-term frequency correction using a servo control system. The effects of Rayleigh-Brillouin scattering on the measurement are shown to be significant and are included in the analysis. Simulations for a conical scanning satellite-based lidar at 355 nm show an accuracy of 2-3 m/s for altitudes of 2 to 15 km for a 1 km vertical resolution, a satellite altitude of 400 km and a 200 km x 200 km spatial resolution. Results of ground based wind measurements are presented.

  8. Development of the Japanese Sword

    NASA Astrophysics Data System (ADS)

    Tanimura, Hiromu

    1980-02-01

    Both the beauty and the utility of the Japanese sword as a weapon depend on the characteristic metallic component structure of the sword blade steel. After briefly describing the characteristics of the sword blade and the history of the Japanese sword, this paper describes the forging process for making the composite structure of the sword blade steel, according to the author's experiences. Finally, andent ironmaking and steelmaking processes are briefly explained. The author concludes that the high purity of the iron and steel obtained to the beauty and artistry of the finished sword blade.

  9. Levodopa is a Double-Edged Sword for Balance and Gait in People with Parkinson’s Disease

    PubMed Central

    Curtze, Carolin; Nutt, John G.; Carlson-Kuhta, Patricia; Mancini, Martina; Horak, Fay B.

    2016-01-01

    Background The effects of levodopa on balance and gait function in people with Parkinson’s disease (PD) is controversial. This study compared the relative responsiveness to levodopa on six domains of balance and gait: postural sway in stance, gait pace, dynamic stability, gait initiation, arm swing, and turning in people with mild and severe PD, with and without dyskinesia. Methods We studied 104 subjects with idiopathic PD (Hohen & Yahr II (n=52) and III-IV (n=52)) and 64 age-matched controls. Subjects performed a mobility task in the practical OFF state and ON levodopa: standing quietly for 30 seconds, initiating gait, walking 7 meters, and turning 180 degrees. Thirty-four measures of mobility were computed from inertial sensors. Standardized response means were used to determine the relative responsiveness to levodopa. Results The largest improvements with levodopa were found for arm swing and pace-related gait measures. Gait dynamic stability was unaffected by PD and not responsive to levodopa. Levodopa reduced turning duration, but only in subjects with severe PD. In contrast to gait, postural sway in quiet standing increased with levodopa, especially in the more severely affected subjects. The increase in postural sway, as well as decrease in turning duration and exaggerated arm swing with levodopa was observed only for subjects with dyskinesia at the time of testing. Conclusions The observed spectrum of levodopa responsiveness in balance and gait measures suggests multiple neural circuits control balance and gait. Many of the negative effects of levodopa may be directly or indirectly caused by dyskinesia. PMID:26095928

  10. Microtubule-Targeting Agents Enter the Central Nervous System (CNS): Double-edged Swords for Treating CNS Injury and Disease

    PubMed Central

    2014-01-01

    Microtubules have been among the most successful targets in anticancer therapy and a large number of microtubule-targeting agents (MTAs) are in various stages of clinical development for the treatment of several malignancies. Given that injury and diseases in the central nervous system (CNS) are accompanied by acute or chronic disruption of the structural integrity of neurons and that microtubules provide structural support for the nervous system at cellular and intracellular levels, microtubules are emerging as potential therapeutic targets for treating CNS disorders. It has been postulated that exogenous application of MTAs might prevent the breakdown or degradation of microtubules after injury or during neurodegeneration, which will thereby aid in preserving the structural integrity and function of the nervous system. Here we review recent evidence that supports this notion and also discuss potential risks of targeting microtubules as a therapy for treating nerve injury and neurodegenerative diseases. PMID:25558415

  11. "Choice" as a double-edged sword: information, guilt and mother-blaming in a high-tech age.

    PubMed

    Gregg, R

    1993-01-01

    Women in the United States experience pregnancy in the context of more medical interventions than ever before. Procreative technologies can enhance both the range of choices for women and the possibility of greater social control of women's choices. Sometimes procreative technologies are a matter of routine, not choice. New developments in genomic research and prenatal diagnosis may lead to the routinization of further medical interventions in pregnancy. Women increasingly may lose the freedom to choose not to use prenatal tests or the information they provide. This article is drawn from a study of women's experiences of pregnancy. The women's stories and two examples of recent news reports demonstrate some of the pressures women face as they attempt to make choices about pregnancy and motherhood. The examples indicate that women face subtle and overt pressures on their "choices." PMID:8266708

  12. The Role of the Immune Response in Chlamydia trachomatis Infection of the Male Genital Tract: A Double-Edged Sword

    PubMed Central

    Redgrove, Kate A.; McLaughlin, Eileen A.

    2014-01-01

    Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection in the world, with more than 100 million cases reported annually. While there have been extensive studies into the adverse effects that CT infection has on the female genital tract, and on the subsequent ability of these women to conceive, studies into the consequences on male fertility have been limited and controversial. This is in part due to the asymptomatic nature of the infection, where it is estimated that 50% of men with Chlamydia fail to show any symptoms. It is accepted, however, that acute and/or persistent CT infection is the causative agent for conditions such as urethritis, epididymitis, epididymo-orchitis, and potentially prostatitis. As with most infections, the immune system plays a fundamental role in the body’s attempts to eradicate the infection. The first and most important immune response to Chlamydia infection is a local one, whereby immune cells such as leukocytes are recruited to the site of infections, and subsequently secrete pro-inflammatory cytokines and chemokines such as interferon gamma. Immune cells also work to initiate and potentiate chronic inflammation through the production of reactive oxygen species (ROS), and the release of molecules with degradative properties including defensins, elastase, collagenase, cathespins, and lysozyme. This long-term inflammation can lead to cell proliferation (a possible precursor to cancer), tissue remodeling, and scarring, as well as being linked to the onset of autoimmune responses in genetically disposed individuals. This review will focus on the ability of the immune system to recognize and clear acute and persistent chlamydial infections in the male genital tract, and on the paradoxical damage that chronic inflammation resulting from the infection can cause on the reproductive health of the individual. PMID:25386180

  13. The nociceptive and anti-nociceptive effects of bee venom injection and therapy: A double-edged sword

    PubMed Central

    Chen, Jun; Lariviere, William R.

    2010-01-01

    Bee venom injection as a therapy, like many other complementary and alternative medicine approaches, has been used for thousands of years to attempt to alleviate a range of diseases including arthritis. More recently, additional theraupeutic goals have been added to the list of diseases making this a critical time to evaluate the evidence for the beneficial and adverse effects of bee venom injection. Although reports of pain reduction (analgesic and antinociceptive) and anti-inflammatory effects of bee venom injection are accumulating in the literature, it is common knowledge that bee venom stings are painful and produce inflammation. In addition, a significant number of studies have been performed in the past decade highlighting that injection of bee venom and components of bee venom produce significant signs of pain or nociception, inflammation and many effects at multiple levels of immediate, acute and prolonged pain processes. This report reviews the extensive new data regarding the deleterious effects of bee venom injection in people and animals, our current understanding of the responsible underlying mechanisms and critical venom components, and provides a critical evaluation of reports of the beneficial effects of bee venom injection in people and animals and the proposed underlying mechanisms. Although further studies are required to make firm conclusions, therapeutic bee venom injection may be beneficial for some patients, but may also be harmful. This report highlights key patterns of results, critical shortcomings, and essential areas requiring further study. PMID:20558236

  14. Unreacted PbI2 as a Double-Edged Sword for Enhancing the Performance of Perovskite Solar Cells.

    PubMed

    Jacobsson, T Jesper; Correa-Baena, Juan-Pablo; Halvani Anaraki, Elham; Philippe, Bertrand; Stranks, Samuel D; Bouduban, Marine E F; Tress, Wolfgang; Schenk, Kurt; Teuscher, Joël; Moser, Jacques-E; Rensmo, Håkan; Hagfeldt, Anders

    2016-08-17

    Lead halide perovskites have over the past few years attracted considerable interest as photo absorbers in PV applications with record efficiencies now reaching 22%. It has recently been found that not only the composition but also the precise stoichiometry is important for the device performance. Recent reports have, for example, demonstrated small amount of PbI2 in the perovskite films to be beneficial for the overall performance of both the standard perovskite, CH3NH3PbI3, as well as for the mixed perovskites (CH3NH3)x(CH(NH2)2)(1-x)PbBryI(3-y). In this work a broad range of characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photo electron spectroscopy (PES), transient absorption spectroscopy (TAS), UV-vis, electroluminescence (EL), photoluminescence (PL), and confocal PL mapping have been used to further understand the importance of remnant PbI2 in perovskite solar cells. Our best devices were over 18% efficient, and had in line with previous results a small amount of excess PbI2. For the PbI2-deficient samples, the photocurrent dropped, which could be attributed to accumulation of organic species at the grain boundaries, low charge carrier mobility, and decreased electron injection into the TiO2. The PbI2-deficient compositions did, however, also have advantages. The record Voc was as high as 1.20 V and was found in PbI2-deficient samples. This was correlated with high crystal quality, longer charge carrier lifetimes, and high PL yields and was rationalized as a consequence of the dynamics of the perovskite formation. We further found the ion migration to be obstructed in the PbI2-deficient samples, which decreased the JV hysteresis and increased the photostability. PbI2-deficient synthesis conditions can thus be used to deposit perovskites with excellent crystal quality but with the downside of grain boundaries enriched in organic species, which act as a barrier toward current transport. Exploring ways to tune the synthesis conditions to give the high crystal quality obtained under PbI2-poor condition while maintaining the favorable grain boundary characteristics obtained under PbI2-rich conditions would thus be a strategy toward more efficiency devices. PMID:27437906

  15. Cooperative Learning--A Double-Edged Sword: A Cooperative Learning Model for Use with Diverse Student Groups

    ERIC Educational Resources Information Center

    Baker, Trish; Clark, Jill

    2010-01-01

    Although very little research has been done on cooperative learning (CL) in New Zealand, international research is positive about the educational benefits of working in culturally diverse groups. This paper presents the findings of a research project examining New Zealand experiences with CL in multicultural groups. Data were collected via surveys…

  16. The double-edged sword: How evolution can make or break a live-attenuated virus vaccine

    PubMed Central

    Hanley, Kathryn A.

    2012-01-01

    Even students who reject evolution are often willing to consider cases in which evolutionary biology contributes to, or undermines, biomedical interventions. Moreover the intersection of evolutionary biology and biomedicine is fascinating in its own right. This review offers an overview of the ways in which evolution has impacted the design and deployment of live-attenuated virus vaccines, with subsections that may be useful as lecture material or as the basis for case studies in classes at a variety of levels. Live- attenuated virus vaccines have been modified in ways that restrain their replication in a host, so that infection (vaccination) produces immunity but not disease. Applied evolution, in the form of serial passage in novel host cells, is a “classical” method to generate live-attenuated viruses. However many live-attenuated vaccines exhibit reversion to virulence through back-mutation of attenuating mutations, compensatory mutations elsewhere in the genome, recombination or reassortment, or changes in quasispecies diversity. Additionally the combination of multiple live-attenuated strains may result in competition or facilitation between individual vaccine viruses, resulting in undesirable increases in virulence or decreases in immunogenicity. Genetic engineering informed by evolutionary thinking has led to a number of novel approaches to generate live-attenuated virus vaccines that contain substantial safeguards against reversion to virulence and that ameliorate interference among multiple vaccine strains. Finally, vaccines have the potential to shape the evolution of their wild type counterparts in counter-productive ways; at the extreme vaccine-driven eradication of a virus may create an empty niche that promotes the emergence of new viral pathogens. PMID:22468165

  17. Intravenous iron supplementation in the anaemia of renal and cardiac failure--a double-edged sword?

    PubMed

    Slotki, Itzchak

    2005-07-01

    The anaemia of chronic kidney disease (CKD) is efficiently corrected with a combination of recombinant erythropoietin (rhEPO) and intravenous iron supplementation. Recently, patients with severe cardiac failure and anaemia have also been shown to benefit from this treatment. However, iron excess may lead to the production of free radicals and has been incriminated in the pathogenesis of atherosclerosis and increased risk of infection, the two major causes of death in end-stage renal disease. The exact risk of excess iron supplementation has not been defined and, in the absence of sensitive and specific indicators of iron overload, the risk remains difficult to quantify. There is increasing epidemiological evidence incriminating iron overload as a risk factor in CKD, but direct evidence is still hard to obtain. The precise role of iron is complicated further by the complex inter-relationships between iron metabolism and the inflammatory process characteristic of CKD. The recent discovery of the antimicrobial peptide, hepcidin, may shed light on these inter-relationships. New methods for quantifying non-transferrin-bound (or labile plasma) iron may help in the future to identify patients at risk for toxicity from excess iron supplementation. PMID:16024827

  18. The Regulatory Environment in Long Day Care: A "Double-Edged Sword" for Early Childhood Professional Practice

    ERIC Educational Resources Information Center

    Fenech, Marianne; Sumsion, Jennifer; Goodfellow, Joy

    2006-01-01

    While early childhood professionals in NSW are accountable to a substantial collection of regulatory requirements, little research has explored the outcomes of this regulatory environment, both intended and otherwise. This paper presents findings from a NSW study and shows how early childhood professionals working in long day care centres perceive…

  19. Extending Antecedents of Achievement Goals: The Double-Edged Sword Effect of Social-Oriented Achievement Motive and Gender Differences

    ERIC Educational Resources Information Center

    Nie, Youyan; Liem, Gregory Arief D.

    2013-01-01

    Underpinned by the hierarchical model of approach and avoidance motivation, the study examined the differential relations of individual-oriented and social-oriented achievement motives to approach and avoidance achievement goals (mastery-approach, performance-approach, mastery-avoidance, performance-avoidance). A total of 570 Chinese high school…

  20. Social Network as Double-Edged Sword to Exchange: Frictions and the Emerging of Intellectual Intermediary Service

    NASA Astrophysics Data System (ADS)

    Li, Li; Wu, Bangtao; Chen, Zhong; Zhao, Liangjie

    The value of complex social network and the optimization of it are determined by the structure and nodes’ characteristics. Direct friction and indirect friction are defined to describe the possible exchange difficulty each node meets with its neighbors in exchange network. Exogenous intermediary and endogenous intermediary can decrease these frictions by adding links. Agent-based Simulating results show that both frictions and the optimization of them are influenced by demander and supplier rate, the exchange network structure as well as the environment constrains and exogenous intermediation acts better than endogenous intermediation in decreasing both frictions. While assists exchange, the results of this paper also implies social network as origin of impefect market.

  1. Can We Afford These Affordances? GarageBand and the Double-Edged Sword of the Digital Audio Workstation

    ERIC Educational Resources Information Center

    Bell, Adam Patrick

    2015-01-01

    The proliferation of computers, tablets, and smartphones has resulted in digital audio workstations (DAWs) such as GarageBand in being some of the most widely distributed musical instruments. Positing that software designers are dictating the music education of DAW-dependent music-makers, I examine the fallacy that music-making applications such…

  2. Gendered Uncertainty and Variation in Physicians' Decisions for Coronary Heart Disease: The Double-Edged Sword of "Atypical Symptoms"

    ERIC Educational Resources Information Center

    Welch, Lisa C.; Lutfey, Karen E.; Gerstenberger, Eric; Grace, Matthew

    2012-01-01

    Nonmedical factors and diagnostic certainty contribute to variation in clinical decision making, but the process by which this occurs remains unclear. We examine how physicians' interpretations of patient sex-gender affect diagnostic certainty and, in turn, decision making for coronary heart disease. Data are from a factorial experiment of 256…

  3. Von Willebrand factor in patients on mechanical circulatory support – a double-edged sword between bleeding and thrombosis

    PubMed Central

    Kaczmarski, Jacek; Pacholewicz, Jerzy; Zakliczynski, Michal; Gasior, Mariusz; Zembala, Marian

    2015-01-01

    Mechanical circulatory support (MCS) is an umbrella term describing the various technologies used in both short- and long-term management of patients with either end-stage chronic heart failure (HF) or acute HF. Most often, MCS has emerged as a bridge to transplantation, but more recently it is also used as a destination therapy. Mechanical circulatory support includes left ventricular assist device (LVAD) or bi-ventricular assist device (Bi-VAD). Currently, 2- to 3-year survival in carefully selected patients is much better than with medical therapy. However, MCS therapy is hampered by sometimes life-threatening complications including bleeding and device thrombosis. Von Willebrand factor (vWF) has two major functions in haemostasis. First, it plays a crucial role in platelet-subendothelium adhesion and platelet-platelet interactions (aggregation). Second, it is the carrier of factor VIII (FVIII) in plasma. Von Willebrand factor prolongs FVIII half-time by protecting it from proteolytic degradation. It delivers FVIII to the site of vascular injury thus enhancing haemostatic process. On one hand, high plasma levels of vWF have been associated with an increased risk of thrombosis. On the other, defects or deficiencies of vWF underlie the inherited von Willebrand disease or acquired von Willebrand syndrome. Here we review the pathophysiology of thrombosis and bleeding associated with vWF. PMID:26702279

  4. Massing in high shear wet granulation can simultaneously improve powder flow and deteriorate powder compaction: a double-edged sword.

    PubMed

    Shi, Limin; Feng, Yushi; Sun, Changquan Calvin

    2011-05-18

    The influence of massing during high shear wet granulation (HSWG) process on granule properties and performance was investigated using microcrystalline cellulose (MCC). Massing time varied from 0 to 40 min while other factors were fixed. Granule physical properties, including morphology, size, porosity, and specific surface area (SSA), were characterized. Changes in powder properties were profound in the first 10 min of massing but negligible beyond 10 min. With 10 min of massing, granule tabletability decreased by 75% while flowability increased by 75%. The significantly deteriorated tabletability and improved flowability resulted from dramatic changes in granule morphology, porosity, and SSA. The results confirm that massing time is a key process parameter in HSWG, and it must be carefully evaluated and controlled during process development, scale up, and manufacturing. PMID:21443948

  5. MTF measurement of IRFPA based on double-knife edge scanning method

    NASA Astrophysics Data System (ADS)

    Ying, Cheng-ping; Wu, Bin; Wang, Heng-fei; Shi, Xue-shun; Liu, Hong-yuan

    2013-09-01

    Modulation transfer function (MTF) is one of the most important parameters of infrared focal plane array (IRFPA). A double-knife edge scanning method is proposed for MTF measurement of IRFPA. In this method, a double-knife edge was used as a target, and the IRFPA under test was positioned in the focal plane of the imaging optical system by a 3-axis translation stage. With an IRFPA data acquisition system, the image of the double-knife edge was restored. By scanning in the direction orthogonal to the double-knife edge image, edge spread function (ESF) curve of each pixel swept across the knife-edge image was obtained. MTF could be calculated from the subsequent fitting, differential and Fourier transformation procedures. With double-knife edge scanning, two ESF curves of double-knife edge were obtained simultaneously, and symmetry of the two ESF curves could be used to evaluate the verticality between photosensitive surface of IRFPA and optical axis of the double-knife edge imaging system. In addition, this method can be used to judge the existing of interference from outside such as vibration, stray light and electrical noise. A measurement facility for IRFPA's MTF based on double-knife edge scanning method was also established in this study. The facility is composed of double-knife edge imaging optical system, 3-axis translation stage and data acquisition system, et al. As the kernel of the facility, the double-knife edge imaging optical system mainly comprises two symmetrical parabolic mirrors coating with reflective material, and the magnification of the optical system is 1 with an operation wavelength range of (1˜14) μm.

  6. In-line digital holography with double knife edge

    NASA Astrophysics Data System (ADS)

    Ramirez, Claudio; Iemmi, Claudio; Campos, Juan

    2015-06-01

    We study and test a new technique for in-line digital holography which avoids the formation of the conjugate images. Inline digital holography is based in a common path configuration. In this case, the hologram is produced by the interference between the reference wave front and the diffracted wave front by an almost transparent object. Twin images are obtained with obscured rings that difficult the determination of the best focusing plane. To avoid the conjugated image, the information of the magnitude and phase of the wave front are needed. In a recent work a new in-line digital holography technique was proposed. In this method the object is illuminated with a collimated wave front. A plane, close to the particles distribution is imaged onto a CCD by means of a convergent lens and at the same time, a knife edge is placed in the focal plane of the lens in order to block half of spatial frequency spectrum. In this way, by means of a numerical processing performed on the Fourier plane, it is possible to eliminate one of the components (real or conjugate) of the reconstructed images nevertheless it is observed a tiny deformation of the resulting hologram image. To compensate this effect, we propose a new configuration in which we implement the knife edge technique on both parts of the spectrum at the same time. Finally in the computer, we process the holograms to build one complete without deformation. This hologram is used to recover the wave front at different planes without the influence of the conjugate image.

  7. Edge effects in vertically-oriented graphene based electric double-layer capacitors

    NASA Astrophysics Data System (ADS)

    Yang, Huachao; Yang, Jinyuan; Bo, Zheng; Zhang, Shuo; Yan, Jianhua; Cen, Kefa

    2016-08-01

    Vertically-oriented graphenes (VGs) have been demonstrated as a promising active material for electric double-layer capacitors (EDLCs), partially due to their edge-enriched structure. In this work, the 'edge effects', i.e., edges as the promoters of high capacitance, in VG based EDLCs are investigated with experimental research and numerical simulations. VGs with diverse heights (i.e., edge-to-basal ratios) and edge densities are prepared with varying the plasma-enabled growth time and employing different plasma sources. Electrochemical measurements show that the edges play a predominant role on the charge storage behavior of VGs. A simulation is further conducted to unveil the roles of the edges on the separation and adsorption of ions within VG channels. The initial charge distribution of a VG plane is obtained with density functional theory (DFT) calculations, which is subsequently applied to a molecular dynamics (MD) simulation system to gain the insights into the microscope EDLC structures. Compared with the basal planes, the edges present higher initial charge density (by 4.2 times), higher ion packing density (by 2.6 times), closer ion packing location (by 0.8 Å), and larger ion separation degree (by 14%). The as-obtained findings will be instructive in designing the morphology and structure of VGs for enhanced capacitive performances.

  8. Doppler Lidar Measurements of Tropospheric Wind Profiles Using the Aerosol Double Edge Technique

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Mathur, Savyasachee; Korb, C. Laurence; Chen, Huailin

    2000-01-01

    The development of a ground based direct detection Doppler lidar based on the recently described aerosol double edge technique is reported. A pulsed, injection seeded Nd:YAG laser operating at 1064 nm is used to make range resolved measurements of atmospheric winds in the free troposphere. The wind measurements are determined by measuring the Doppler shift of the laser signal backscattered from atmospheric aerosols. The lidar instrument and double edge method are described and initial tropospheric wind profile measurements are presented. Wind profiles are reported for both day and night operation. The measurements extend to altitudes as high as 14 km and are compared to rawinsonde wind profile data from Dulles airport in Virginia. Vertical resolution of the lidar measurements is 330 m and the rms precision of the measurements is a low as 0.6 m/s.

  9. Daniel Shays and Lafayette's Sword.

    ERIC Educational Resources Information Center

    Gross, Robert A.

    1987-01-01

    Reports on the story of Daniel Shays' sale of a sword given to him by General Lafayette. The story was used by Shays' contemporaries as a means of attacking the rebellion. Notes that while Shay died a poor and homeless man, we remember and honor him for devotion to principle and the responsibility he showed toward his neighbors. (JDH)

  10. The Sword of Orion

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] AnimationFigure 1

    This infrared image from NASA's Spitzer Space Telescope shows the Orion nebula, our closest massive star-making factory, 1,450 light-years from Earth. The nebula is close enough to appear to the naked eye as a fuzzy star in the sword of the popular hunter constellation.

    The nebula itself is located on the lower half of the image, surrounded by a ring of dust. It formed in a cold cloud of gas and dust and contains about 1,000 young stars. These stars illuminate the cloud, creating the beautiful nebulosity, or swirls of material, seen here in infrared.

    In the center of the nebula (bottom inset of figure 1) are four monstrously massive stars, up to 100,000 times as luminous as our sun, called the Trapezium (tiny yellow smudge to the lower left of green splotches. Radiation and winds from these stars are blasting gas and dust away, excavating a cavity walled in by the large ring of dust.

    Behind the Trapezium, still buried deeply in the cloud, a second generation of massive stars is forming (in the area with green splotches). The speckled green fuzz in this bright region is created when bullets of gas shoot out from the juvenile stars and ram into the surrounding cloud.

    Above this region of intense activity are networks of cold material that appear as dark veins against the pinkish nebulosity (upper inset pf figure 1). These dark veins contain embryonic stars. Some of the natal stars illuminate the cloud, creating small, aqua-colored wisps. In addition, jets of gas from the stars ram into the cloud, resulting in the green horseshoe-shaped globs.

    Spitzer surveyed a significant swath of the Orion constellation, beyond what is highlighted in this image. Within that region, called the Orion cloud complex, the telescope found 2,300 stars circled by disks of planet-forming dust and 200 stellar embryos too young to have developed

  11. A survey of the Saturnian ring edges: Results from double star occultations

    NASA Astrophysics Data System (ADS)

    Albers, Nicole

    2015-11-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS) High Speed Photometer (HSP) has recorded more than 150 stellar occultations of Saturn's rings. About one third are observations involving double stars, where each star contributes its own, independent light curve. For each light curve, its footprint, as projected into the ring plane and depending on observation geometry, samples a different region in the ring. Here, we focus on ring edges. Each occultation then yields two independent edge measurements at two different times and longitudes. We infer relative changes in optical depth and radial position over an azimuthal distance as short as 20 meters. These relative measurements require neither photometric nor geometric calibration and inform on the small-scale variability of structure/features with relative resolutions an order of magnitude higher than typically achieved.The Encke and Keeler gap edges as well as the outer B and A ring edges show radial excursions on the order of tens of meters. These radial variations are, in comparison to the common multi-mode analysis of edge kinematics, high-frequency components with corresponding m numbers of m>5000000. We note that spatial dimensions inferred here are 10-100 times smaller than those of features Region A and B at the B ring edge or "Peggy"-type objects at the A ring edge, and are comparable to individual self-gravity wakes or clumps/particles. The Titan and Huygens ringlets inner and outer edges, on the other hand, are, in comparison, highly regular and smooth with radial variations of only a few meters. Nevertheless they show changes in normal optical depth on the order of 0.4, well above the expected margin due to intrinsic stellar variability. We also identified three features in the C ring that show little radial variability and can thus be considered smooth. Interestingly, this irregularity or raggedness of the edges - manifestation of intrinsic small-scale structure of the ring - is stronger with

  12. Empirical Determination of Optimal Parameters for Sodium Double-Edge Magneto-Optic Filters

    NASA Astrophysics Data System (ADS)

    Barry, Ian F.; Huang, Wentao; Smith, John A.; Chu, Xinzhao

    2016-06-01

    A method is proposed for determining the optimal temperature and magnetic field strength used to condition a sodium vapor cell for use in a sodium Double-Edge Magneto-Optic Filter (Na-DEMOF). The desirable characteristics of these filters are first defined and then analyzed over a range of temperatures and magnetic field strengths, using an IDL Faraday filter simulation adapted for the Na-DEMOF. This simulation is then compared to real behavior of a Na-DEMOF constructed for use with the Chu Research Group's STAR Na Doppler resonance-fluorescence lidar for lower atmospheric observations.

  13. Compton-edge-based energy calibration of double-sided silicon strip detectors in Compton camera

    NASA Astrophysics Data System (ADS)

    Seo, Hee; Park, Jin Hyung; Kim, Chan Hyeong; Lee, Ju Hahn; Lee, Chun Sik; Sung Lee, Jae

    2011-05-01

    Accurate energy calibration of double-sided silicon strip detectors (DSSDs) is very important, but challenging for high-energy photons. In the present study, the calibration was improved by considering the Compton edge additionally to the existing low-energy calibration points. The result, indeed, was very encouraging. The energy-calibration errors were dramatically reduced, from, on average, 15.5% and 16.9% to 0.47% and 0.31% for the 356 (133Ba) and 662 keV (137Cs) peaks, respectively. The imaging resolution of a double-scattering-type Compton camera using DSSDs as the scatterer detectors, for a 22Na point-like source, also was improved, by ˜9%.

  14. DNA Repair—A Double-Edged Sword in the Genomic Stability of Cancer Cells—The Case of Chronic Myeloid Leukemia

    PubMed Central

    Pawlowska, Elzbieta; Blasiak, Janusz

    2015-01-01

    Genomic instability is a common feature of cancer cells, which can result from aberrant DNA damage reaction (DDR). We and others showed that the well-known BCR-ABL1 fusion oncogene, the cause of chronic myeloid leukemia, induced an increased production of reactive oxygen species (ROS) and conferred therapeutic drug resistance by suppression of apoptotic signaling, prolonged G2/M arrest and stimulation of several pathways of DNA repair. However, to protect from apoptosis, cancer cells may tolerate some DNA lesions, which may increase genomic instability. Moreover, BCR/ABL1-stimulated DNA repair might be faulty, especially non-homologous end joining in its alternative forms. Normal DNA repair can remove DNA damage and prevent mutations, reducing genome instability, but on the other hand, due to its imprecise nature, it may increase genomic instability by increasing the ratio of mutagenic DNA lesions. The example of BCR-ABL1-expressing cells shows that DNA repair can both increase and decrease genomic instability of cancer cells and understanding the mechanism of the regulation of these opposite effects would be helpful in anticancer strategies. PMID:26593906

  15. The double-edged sword of the mammalian oocyte--advantages, drawbacks and approaches for basic and clinical analysis at the single cell level.

    PubMed

    Brayboy, L M; Wessel, G M

    2016-03-01

    Oocytes are usually the largest cells in the body and as such offer unique opportunities for single-cell analysis. Unfortunately, these cells are also some of the rarest in the mammalian female, usually necessitating single-cell analysis. In cases of infertility in humans, determining the quality of the oocyte is often restricted to a morphological analysis or to the study of cellular behaviors in the developing embryo. Minimally invasive approaches could greatly assist the clinician to prioritize oocytes for fertilization or following fertilization, which embryo to transfer back into the woman. Transcriptomics of human and mouse oocytes may have great utility, and recently it was learned that the polar body faithfully reflects the transcript prevalence in the oocyte. The polar body may thus serve as a minimally invasive proxy for an oocyte in the clinic. In the mouse, the transcriptomes of oocytes from mice of the same strain are markedly similar; no significant differences are apparent in transcript prevalence or identity. In human oocytes however, the transcript pool is highly variable. This is likely the result of different histories of each oocyte, in the age of the donor woman, the different hormonal exposures and the prolonged time from specification of the primary oocyte to the fully grown and ovulated egg. This variability in human oocytes also emphasizes the need for cell-by-cell analysis of the oocytes in vitro; which oocytes have a better potential for fertilization and development? To this end, new imaging capabilities are being employed. For example, a single-cell analytical device for oocytes (the simple perfusion apparatus, or SPA) enables investigators to load multiple oocytes in individual wells, to visualize them on the microscope and to use controlled temperature and media flow by perfusion for optimal clinical applications. Recently, developed Raman microspectroscopy approaches suggest that this imaging modality may enable more in-depth analysis of the molecular characteristics of an oocyte that, in combination with the SPA and transcriptomic approaches, might assist the clinician to prioritize more effectively human oocytes and embryos for transfer into women. This review is intended to update the reader on the status of the examination of single oocytes from a variety of approaches and to emphasize areas that may be primed for advancement in the near future. PMID:26590170

  16. Mutations for Worse or Better: Low-Fidelity DNA Synthesis by SOS DNA Polymerase V Is a Tightly Regulated Double-Edged Sword.

    PubMed

    Jaszczur, Malgorzata; Bertram, Jeffrey G; Robinson, Andrew; van Oijen, Antoine M; Woodgate, Roger; Cox, Michael M; Goodman, Myron F

    2016-04-26

    1953, the year of Watson and Crick, bore witness to a less acclaimed yet highly influential discovery. Jean Weigle demonstrated that upon infection of Escherichia coli, λ phage deactivated by UV radiation, and thus unable to form progeny, could be reactivated by irradiation of the bacterial host. Evelyn Witkin and Miroslav Radman later revealed the presence of the SOS regulon. The more than 40 regulon genes are repressed by LexA protein and induced by the coproteolytic cleavage of LexA, catalyzed by RecA protein bound to single-stranded DNA, the RecA* nucleoprotein filament. Several SOS-induced proteins are engaged in repairing both cellular and extracellular damaged DNA. There's no "free lunch", however, because error-free repair is accompanied by error-prone translesion DNA synthesis (TLS), involving E. coli DNA polymerase V (UmuD'2C) and RecA*. This review describes the biochemical mechanisms of pol V-mediated TLS. pol V is active only as a mutasomal complex, pol V Mut = UmuD'2C-RecA-ATP. RecA* donates a single RecA subunit to pol V. We highlight three recent insights. (1) pol V Mut has an intrinsic DNA-dependent ATPase activity that governs polymerase binding and dissociation from DNA. (2) Active and inactive states of pol V Mut are determined at least in part by the distinct interactions between RecA and UmuC. (3) pol V is activated by RecA*, not at a blocked replisome, but at the inner cell membrane. PMID:27043933

  17. The Double Edged Sword: A Brief Comparison of IT and Internet Development in Malaysia and Some Few Neighboring Countries in the Context of Digital Divide.

    ERIC Educational Resources Information Center

    Samad, Ramli Abdul

    This paper shows that, although a digital divide exists between developed and developing countries, the development of information technology (IT) and the Internet has had a profound political, social, and economic impact on developing countries. IT and the Internet revolution are shaping the world into new polarized entities due to the uneven…

  18. Are Academic Discounting and Devaluing Double-Edged Swords? Their Relations to Global Self-Esteem, Achievement Goals, and Performance among Stigmatized Students

    ERIC Educational Resources Information Center

    Loose, Florence; Regner, Isabelle; Morin, Alexandre J. S.; Dumas, Florence

    2012-01-01

    Often taken for granted, the coexistence of benefits and costs of discounting and devaluing has never been tested. Yet, not only are there inconsistent findings about the relations between these processes and global self-esteem, but little is known about their relations to motivation and performance. Here we simultaneously examined how academic…

  19. The double-edged sword of high-precision U-Pb geochronology or be careful what you wish for. (Invited)

    NASA Astrophysics Data System (ADS)

    Bowring, S. A.

    2010-12-01

    Over the past two decades, U-Pb geochronology by ID-TIMS has been refined to achieve internal (analytical) uncertainties on a single grain analysis of ± ~ 0.1-0.2%, and 0.05% or better on weighted mean dates. This level of precision enables unprecedented evaluation of the rates and durations of geological processes, from magma chamber evolution to mass extinctions and recoveries. The increased precision, however, exposes complexity in magmatic/volcanic systems and highlights the importance of corrections related to disequilibrium partitioning of intermediate daughter products, and raises questions as to how best to interpret the complex spectrum of dates characteristic of many volcanic rocks. In addition, the increased precision requires renewed emphasis on the accuracy of U decay constants, the isotopic composition of U, the calibration of isotopic tracers, and the accurate propagation of uncertainties It is now commonplace in the high precision dating of volcanic ash-beds to analyze 5-20 single grains of zircon in an attempt to resolve the eruption/depositional age. Data sets with dispersion far in excess of analytical uncertainties are interpreted to reflect Pb-loss, inheritance, and protracted crystallization, often supported with zircon chemistry. In most cases, a weighted mean of the youngest reproducible dates is interpreted as the time of eruption/deposition. Crystallization histories of silicic magmatic systems recovered from plutonic rocks may also be protracted, though may not be directly applicable to silicic eruptions; each sample must be evaluated independently. A key to robust interpretations is the integration high-spatial resolution zircon trace element geochemistry with high-precision ID-TIMS analyses. The EARTHTIME initiative has focused on many of these issues, and the larger subject of constructing a timeline for earth history using both U-Pb and Ar-Ar chronometers. Despite continuing improvements in both, comparing dates for the same rock with both chronometers is not straightforward. Compelling issues range from pre-eruptive magma chamber residence, recognizing open system behavior, accurately correcting for disequilibrium amounts of 230Th and 231Pa, precise and accurate dates of fluence monitors for 40Ar/39Ar, and inter-laboratory biases. At present, despite the level of internal precision achievable by each technique, obstacles remain to combining both chronometers.

  20. Extracellular and Intracellular Polyphenol Oxidases Cause Opposite Effects on Sensitivity of Streptomyces to Phenolics: A Case of Double-Edged Sword

    PubMed Central

    Yang, Han-Yu; Chen, Carton W.

    2009-01-01

    Many but not all species of Streptomyces species harbour a bicistronic melC operon, in which melC2 encodes an extracellular tyrosinase (a polyphenol oxidase) and melC1 encodes a helper protein. On the other hand, a melC-homologous operon (melD) is present in all sequenced Streptomyces chromosomes and could be isolated by PCR from six other species tested. Bioinformatic analysis showed that melC and melD have divergently evolved toward different functions. MelD2, unlike tyrosinase (MelC2), is not secreted, and has a narrower substrate spectrum. Deletion of melD caused an increased sensitivity to several phenolics that are substrates of MelD2. Intracellularly, MelD2 presumably oxidizes the phenolics, thus bypassing spontaneous copper-dependent oxidation that generates DNA-damaging reactive oxygen species. Surprisingly, melC+ strains were more sensitive rather than less sensitive to phenolics than melC− strains. This appeared to be due to conversion of the phenolics by MelC2 to more hydrophobic and membrane-permeable quinones. We propose that the conserved melD operon is involved in defense against phenolics produced by plants, and the sporadically present melC operon probably plays an aggressive role in converting the phenolics to the more permeable quinones, thus fending off less tolerant competing microbes (lacking melD) in the phenolic-rich rhizosphere. PMID:19826489

  1. Recent results on 3D double sided detectors with slim edges

    NASA Astrophysics Data System (ADS)

    Pellegrini, G.; Baselga, M.; Christophersen, M.; Ely, S.; Fadeyev, V.; Fleta, C.; Gimenez, A.; Grinstein, S.; Lopez, I.; Lozano, M.; Micelli, A.; Phlips, B. F.; Quirion, D.; Sadrozinski, H. F.-W.; Tsiskaridze, S.

    2013-12-01

    This paper reports on the first characterization of double sided 3D silicon radiation pixel detectors with slim edges. These detectors consist of a three-dimensional array of electrodes that penetrate into the detector bulk with the anode and cathode electrodes etched from opposite sides of the substrate. Different detectors were post-processed using the scribe-cleave-passivate (SCP) technology to make “slim edge” sensors. These sensors have only a minimal amount of inactive peripheral region, for the benefit of the construction of large-area tracker and imaging systems. The target application for this work is the use of 3D slim edge detectors for the ATLAS Forward Physics (AFP) CERN Project, where pixel detectors for position resolution and timing detectors for removal of pile up protons, will be placed as close as possible to the beam to detect diffractive protons at 220 m on either side of the ATLAS interaction point. For this reason the silicon areas should feature the narrowest possible insensitive zone on the sensor edge closest to the beam and withstand high nonuniform irradiation fluences.

  2. Double-peaked edge-bead in drying film of solvent-resin mixtures

    NASA Astrophysics Data System (ADS)

    Shiratori, Suguru; Kubokawa, Toru

    2015-10-01

    A thick ridge of a film arising along the periphery of a substrate, which is the so-called edge-bead, is investigated experimentally and numerically for the case where the bead becomes double-peaked shape in direction away from the periphery of the substrate. It is clarified, by the optical measurement of thickness variations, that the double-peaked bead is separated from a single bead during the drying process, and after the separation, the inner bead moves inward. This motion of the bead is modeled by a lubrication-approximated flow equation, where the Laplace pressure and the solutocapillary effect are taken into account, coupled with the convective and diffusive mass transfer. The numerically simulated motion of the bead shows a good agreement with that obtained by the experiment, and it is revealed that the mechanism how the double-peaked edge-bead is formed. At the early stage of the drying process, a single bead is formed by the Laplace pressure due to the curvature along the substrate periphery. Along this single bead, the concentration gradient is caused by both the spatial distribution of the evaporation rate and the thickness effect on the change rate of the concentration, due to the fact that the resin concentration increases at a faster rate in the thin region. Consequently, the concentration distribution has a local minimum in the middle of the single bead, which drives oppositely directed solutocapillary flows and separates the bead. After the separation, the inner bead moves inward by a kind of a feed-forward mechanism, until the viscosity of the film becomes large enough to suppress the flow.

  3. Double-Edge Molecular Measurement of Lidar Wind Profiles in the VALID Campaign

    NASA Technical Reports Server (NTRS)

    Korb, C. Laurence; Flesia, Cristina; Lolli, Simone; Hirt, Christian

    2000-01-01

    We have developed a transportable container based direct detection Doppler lidar based on the double-edge molecular technique. The pulsed solid state system was built at the University of Geneva. It was used to make range resolved measurements of the atmospheric wind field as part of the VALID campaign at the Observatoire de Haute Provence in Provence, France in July 1999. Comparison of our lidar wind measurements, which were analyzed without knowledge of the results of rawinsonde measurements made under the supervision of ESA, show good agreement with these rawinsondes. These are the first Doppler lidar field measurements made with an eyesafe direct detection molecular-based system at 355 nm and serve as a demonstrator for future spaceborne direct detection wind systems such as the Atmospheric Dynamics mission. Winds are an important contributor to sea surface temperature measurements made with the Tropical Rainfall Measuring Mission (TRMM) and also affect the TRMM rainfall estimates.

  4. Elastic-plastic finite-element analyses of thermally cycled double-edge wedge specimens

    NASA Technical Reports Server (NTRS)

    Kaufman, A.; Hunt, L. E.

    1982-01-01

    Elastic-plastic stress-strain analyses were performed for double-edge wedge specimens subjected to thermal cycling in fluidized beds at 316 and 1088 C. Four cases involving different nickel-base alloys (IN 100, Mar M-200, NASA TAZ-8A, and Rene 80) were analyzed by using the MARC nonlinear, finite element computer program. Elastic solutions from MARC showed good agreement with previously reported solutions obtained by using the NASTRAN and ISO3DQ computer programs. Equivalent total strain ranges at the critical locations calculated by elastic analyses agreed within 3 percent with those calculated from elastic-plastic analyses. The elastic analyses always resulted in compressive mean stresses at the critical locations. However, elastic-plastic analyses showed tensile mean stresses for two of the four alloys and an increase in the compressive mean stress for the highest plastic strain case.

  5. Double-Edge Molecular Measurement of Lidar Wind Profiles at 355 nm

    NASA Technical Reports Server (NTRS)

    Flesia, Cristina; Korb, C. Laurence; Hirt, Christian; Einaudi, Franco (Technical Monitor)

    2000-01-01

    We built a direct detection Doppler lidar based on the double-edge molecular technique and made the first molecular based wind measurements using the eyesafe 355 nm wavelength. Three etalon bandpasses are obtained with Step etalons on a single pair of etalon plates. Long-term frequency drift of the laser and the capacitively stabilized etalon is removed by locking the etalon to the laser frequency. We use a low angle design to avoid polarization effects. Wind measurements of 1 to 2 m/s accuracy are obtained to 10 km altitude with 5 mJ of laser energy, a 750s integration, and a 25 cm telescope. Good agreement is obtained between the lidar and rawinsonde measurements.

  6. Investigation of leading-edge flap performance on delta and double-delta wings at supersonic speeds

    NASA Technical Reports Server (NTRS)

    Covell, Peter F.; Wood, Richard M.; Miller, David S.

    1987-01-01

    An investigation of the aerodynamic performance of leading-edge flaps on three clipped delta and three clipped double-delta wing planforms with aspect ratios of 1.75, 2.11, and 2.50 was conducted in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.90, and 2.16. A primary set of fullspan leading-edge flaps with similar root and tip chords were investigated on each wing, and several alternate flap planforms were investigated on the aspect-ratio-1.75 wings. All leading-edge flap geometries were effective in reducing the drag at lifting conditions over the range of wing aspect ratios and Mach numbers tested. Application of a primary flap resulted in better flap performance with the double-delta planform than with the delta planform. The primary flap geometry generally yielded better performance than the alternate flap geometries tested. Trim drag due to flap-induced pitching moments was found to reduce the leading-edge flap performance more for the delta planform than for the double-delta planform. Flow-visualization techniques showed that leading-edge flap deflection reduces crossflow shock-induced separation effects. Finally, it was found that modified linear theory consistently predicts only the effects of leading-edge flap deflection as related to pitching moment and lift trends.

  7. Fracture characteristics of HAZ-double edge notched weld joints with mechanical undermatching

    SciTech Connect

    Zarzour, J.F.; Kleinosky, M.J.

    1995-12-31

    Both experimental and finite element investigations were carried out on double edge notched weld joints in tension to determine the influence of material gradients across the heat affected zone (HAZ) on cracks located at three interface regions: (1) base plate and fine grain HAZ, (2) coarse grain HAZ and fine grain HAZ, (3) weld metal and coarse grain HAZ. For HY-100 steel with a 20 percent weld undermatch, it was concluded that for case (a), the different mechanical properties of both fine grain HAZ (FGHAZ) and coarse grain HAZ (CGHAZ), obtained with a novel indentation technique, greatly affect the near tip stress fields and promote yielding into the base plate. For case (b), the stress triaxiality at the crack tip is the highest and the plastic deformation is confined to the HAZ zone. Finally for case (c), the stress triaxiality is lowered by the presence of a softer weld metal. However, there is a possibility of gross section yielding through the weld area. The overall conclusion indicates that, in order to evaluate crack initiation in the HAZ, one needs to verify the relevant microstructure and determine the mechanical properties of each constituent, mainly, the CGHAZ and FGHAZ. In addition, the assumption of homogeneous HAZ properties may lead to erroneous conclusions.

  8. Specular Andreev reflection at the edge of an InAs/GaSb double quantum well with band inversion

    NASA Astrophysics Data System (ADS)

    Kononov, A.; Egorov, S. V.; Kostarev, V. A.; Semyagin, B. R.; Preobrazhenskii, V. V.; Putyato, M. A.; Emelyanov, E. A.; Deviatov, E. V.

    2016-07-01

    We experimentally investigate transport through the side junction between a niobium superconductor and the mesa edge of a two-dimensional system, realized in an InAs/GaSb double quantum well with band inversion. We demonstrate, that different transport regimes can be achieved by variation of the mesa step. We observe anomalous behavior of Andreev reflection within a finite low-bias interval, which is invariant for both transport regimes. We connect this behavior with the transition from retro- (at low biases) to specular (at high ones) Andreev reflection channels in an InAs/GaSb double quantum well with band inversion.

  9. UEDGE simulation of edge plasmas in DIII-D double null configurations

    SciTech Connect

    Porter, G. D.; Rognlien, T. D.; Rensink, M. E.; Petrie, T. W.

    2010-11-15

    Analysis of plasma flow in the edge of double null hybrid mode DIII-D plasmas is reported. The two dimension fluid plasma code UEDGE [T. Rognlien et al., J. Nucl. Mater. 196-198, 347 (1992)] is used for the analysis. The effect of impurity radiation from intrinsic carbon sputtered from plasma facing surfaces is included as is the effect of plasma drifts. Two discharges in which the flux surfaces through the poloidal field nulls (X-points) are separated by 1 cm at the outer midplane are analyzed. The discharges differ only in the direction of the ion {nabla}B drift. It is shown that the flow of both primary ions and intrinsic impurities is dominated by the effect of plasma drifts. Variations in the recycling of deuterium ions, as seen in D{sub {alpha}} emission profiles, are qualitatively consistent with experiment and are driven by the effect of ExB drifts associated with radial gradients of the electron temperature at the secondary separatrix. Trace argon impurity is introduced to simulate the transport of argon used in the experiment to enhance divertor radiation power. Penetration of the trace argon to the closed field lines depends on the direction of the ion {nabla}B drift, consistent with experiment. The analysis described here includes the effect of a deuterium gas puff to establish the ''puff and pump'' configuration. The poloidal flow of impurities is a balance between the projection of the parallel flow and poloidal drifts, primarily from ExB. It is shown that the effect of the gas puff is primarily to alter the electron temperature profile and thus affects impurity flow via alteration of ExB drifts, not via entrainment in deuterium ion parallel flow.

  10. Rational behavior is a ‘double-edged sword’ when considering voluntary vaccination

    NASA Astrophysics Data System (ADS)

    Zhang, Haifeng; Fu, Feng; Zhang, Wenyao; Wang, Binghong

    2012-10-01

    behavior of individuals plays a ‘double-edged-sword’ role on the social effects.

  11. Esophageal perforation in a sword swallower.

    PubMed

    Scheinin, S A; Wells, P R

    2001-01-01

    We present the case of a 59-year-old man who sustained an esophageal perforation as a result of sword swallowing. An esophagogram established the diagnosis, and surgical repair was attempted. However, 19 days later, a persistent leak and deterioration of the patient's condition necessitated a transhiatal esophagectomy with a left cervical esophagogastrostomy. The patient recovered and has resumed his daily activities at the circus, with the exception of sword swallowing. This case report presents an unusual mechanism for a potentially lethal injury. Our search of the English-language medical literature revealed no other report of esophageal perforation resulting from sword swallowing. Management of such an injury is often difficult, and a favorable outcome is dependent on prompt diagnosis and treatment. PMID:11330747

  12. Measurement of edge plasma parameters in IR-T1 Tokamak by double Langmuir probe

    SciTech Connect

    Ghoranneviss, M.; Khademian, A.; Masnavi, M.; Khorshid, P.; Salami, M.R.

    1996-12-31

    IR-T1 Tokamak is an air-core transformer type Tokamak. The vacuum chamber was made of 4 mm thick stainless steel with minor and major radii of 12.5 cm and 45 cm as respectively. Measurements of T{sub e} have been observed in IR-T1 with fabricated circuits of double pore design. This pore can be movable in the horizontal direction, therefore one can measure temperature along 1 cm distance. This note presents a theoretical and experimental explanation of double probe techniques. Details will be discussed in the full paper.

  13. Homicide attempt with a Japanese samurai sword.

    PubMed

    Raul, Jean-Sébastien; Berthelon, Laurent; Geraut, Annie; Tracqui, Antoine; Ludes, Bertrand

    2003-07-01

    The use of Japanese swords for homicidal attempts is rare. A Japanese samurai sword is a sharp and cutting object. When faced with the use of this weapon, one must distinguish between stabs and incised wounds. Incised wounds can rarely lead to death, but because of the size of the weapon, stabs usually cause much more serious injuries. Stabs also imply a penetrating movement, whereas incised wounds can be the consequence of protective circular blows. Therefore, it is important to distinguish clinically between these two kinds of wounds. We report a case where the perpetrator argued he had given a circular blow, unfortunately hitting the victim. The pieces of evidence are discussed. PMID:12877304

  14. Superconducting Edge-Mode Transport in InAs/GaSb Double Quantum Wells

    NASA Astrophysics Data System (ADS)

    Pribiag, Vlad

    2015-03-01

    In proximity to a superconductor, topological insulators are predicted to host topological superconductivity, an exotic state of matter that supports Majorana zero-modes. Localized Majorana modes are expected to obey non-Abelian exchange statistics, making them interesting building blocks for topological quantum computing. Here we report supercurrent in the edge modes of Type-II InAs/GaSb quantum wells, a two-dimensional topological insulator (2D TI). By electrostatically-gating the devices we observe superconducting transport in all three regimes of the 2D TI: bulk electrons, edge modes and bulk holes. From superconducting quantum interference measurements, we extract the spatial distribution of the supercurrent in each regime. A clear transition to edge-dominated supercurrent is observed under conditions of high bulk resistivity, which we associate with the 2D topological phase. These experiments establish InAs/GaSb as a promising platform for confinement of Majoranas into localized states, enabling future investigations of non-Abelian statistics. Current affiliation: School of Physics and Astronomy, University of Minnesota.

  15. The Pill vs. the Sword: Additional Considerations

    PubMed Central

    Lottes, Ilsa L.

    2015-01-01

    In this paper, I present additional information for policy-makers and researchers to consider in response to the view proposed by Potts et al that "the pill is mightier than the sword." I identify states with both high rates of terrorism and a youth bulge and discuss correlates of both these societal characteristics. The research examined supports the view that factors other than access to family planning are more important in facilitating terrorism. PMID:26673473

  16. The two-edged sword: how technology shapes medical practice.

    PubMed

    Patton, G A

    2001-01-01

    Technology is assuming an increasingly important role in medical practice and health care delivery, fueled by forces such as uncertainty, variability, error, and quality problems. While the benefits of technology are obvious, there are insidious costs that are harder to discern. Technology has a significant, but less appreciated, role in imposing standards and constraints upon medicine. These ancillary effects account for some of the physician reluctance to embrace technological innovations perceived as controlling. This article explores technology's wide-ranging effects in shaping medical care delivery. Technology is not a passive servant of the health care delivery system, but rather acts as a catalyst and shaper of that system. In the process of becoming more technological, medicine has been transformed from a profession with unmatched sovereignty into an industry shaped by technology amidst a context of social and political forces. PMID:11291220

  17. People vs. Collins: Statistics as a Two-Edged Sword

    ERIC Educational Resources Information Center

    McGivney-Burelle, Jean; McGivney, Katherine; McGivney, Ray

    2006-01-01

    Real-life applications of the use (and misuse) of mathematics invariably pique students' interest. This article describes a legal case in California that occurred in the 1960s in which a couple was convicted of robbery, in part, based on the expert testimony of a statistics instructor. On appeal, the judge noted several mathematical errors in this…

  18. Asymptotic theory of double layer and shielding of electric field at the edge of illuminated plasma

    SciTech Connect

    Benilov, M. S.; Thomas, D. M.

    2014-04-15

    The method of matched asymptotic expansions is applied to the problem of a collisionless plasma generated by UV illumination localized in a central part of the plasma in the limiting case of small Debye length λ{sub D}. A second-approximation asymptotic solution is found for the double layer positioned at the boundary of the illuminated region and for the un-illuminated plasma for the plane geometry. Numerical calculations for different values of λ{sub D} are reported and found to confirm the asymptotic results. The net integral space charge of the double layer is asymptotically small, although in the plane geometry it is just sufficient to shield the ambipolar electric field existing in the illuminated region and thus to prevent it from penetrating into the un-illuminated region. The double layer has the same mathematical nature as the intermediate transition layer separating an active plasma and a collisionless sheath, and the underlying physics is also the same. In essence, the two layers represent the same physical object: a transonic layer.

  19. Numerical simulation of the vortical flow over a round-edged double-delta wing

    NASA Technical Reports Server (NTRS)

    Hsu, C.-H.; Liu, C. H.

    1988-01-01

    Simulations of three-dimensional vortical flows over a thin double-delta wing with an aspect ratio of 2.05 have been performed. Steady-state solutions to the unsteady incompressible Navier-Stokes equations are obtained using a new implicit upwind-relaxation finite-difference scheme. The method is second-order accurate spatially and naturally dissipative. Numerical results indicate that key features of both vortical interaction and vortex breakdown are successfully simulated. The computed lift coefficients and lateral trajectories of the vortical cores are in good agreement with the experimental data.

  20. Estimation of Neutral Density in Edge Plasma with Double Null Configuration in EAST

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Xu, Guosheng; Ding, Siye; Gao, Wei; Wu, Zhenwei; Chen, Yingjie; Huang, Juan; Liu, Xiaoju; Zang, Qing; Chang, Jiafeng; Zhang, Wei; Li, Yingying; Qian, Jinping

    2011-08-01

    In this work, population coefficients of hydrogen's n = 3 excited state from the hydrogen collisional-radiative (CR) model, from the data file of DEGAS 2, are used to calculate the photon emissivity coefficients (PECs) of hydrogen Balmer-α (n = 3 → n = 2) (Hα). The results are compared with the PECs from Atomic Data and Analysis Structure (ADAS) database, and a good agreement is found. A magnetic surface-averaged neutral density profile of typical double-null (DN) plasma in EAST is obtained by using FRANTIC, the 1.5-D fluid transport code. It is found that the sum of integral Dα and Hα emission intensity calculated via the neutral density agrees with the measured results obtained by using the absolutely calibrated multi-channel poloidal photodiode array systems viewing the lower divertor at the last closed flux surface (LCFS). It is revealed that the typical magnetic surface-averaged neutral density at LCFS is about 3.5 × 1016 m-3.

  1. Double-difference traveltime tomography with edge-preserving regularization and a priori interfaces

    NASA Astrophysics Data System (ADS)

    Lin, Youzuo; Syracuse, Ellen M.; Maceira, Monica; Zhang, Haijiang; Larmat, Carene

    2015-05-01

    Conventional traveltime seismic tomography methods with Tikhonov regularization (L2 norm) typically produce smooth models, but these models may be inappropriate when subsurface structure contains discontinuous features, such as faults or fractures, indicating that tomographic models should contain sharp boundaries. For this reason, we develop a double-difference (DD) traveltime tomography method that uses a modified total-variation regularization scheme incorporated with a priori information on interfaces to preserve sharp property contrasts and obtain accurate inversion results. In order to solve the inversion problem, we employ an alternating minimization method to decouple the original DD tomography problem into two separate subproblems: a conventional DD tomography with Tikhonov regularization and a L2 total-variation inversion. We use the LSQR linear solver to solve the Tikhonov inversion and the split-Bregman iterative method to solve the total-variation inversion. Through our numerical examples, we show that our new DD tomography method yields more accurate results than the conventional DD tomography method at almost the same computational cost.

  2. System Administration Support/SWORDS G2

    NASA Technical Reports Server (NTRS)

    Dito, Scott Joseph

    2014-01-01

    The Soldier-Warfighter Operationally Responsive Deployer for Space (SWORDS) rocket is a dedicated small satellite launcher that will minimize danger and complexity in order to allow soldiers in the field to put payloads of up to 25kg into orbit from the field. The SWORDSG2 project is the development of a model, simulation, and ultimately a working application that will control and monitor the cryogenic fluid delivery to the SWORDS rocket for testing purposes. To accomplish this, the project is using the programming language environment Gensym G2. The environment is an all-inclusive application that allows development, testing, modeling, and finally operation of the unique application through graphical and programmatic methods. In addition, observation of the current cryogenic fluid delivery system in the Kennedy Space Center Cry Lab has allowed me to gain valuable experience of fluid systems and propelant delivery that is valuable to our team when developing amd modeling our own system.The ultimate goal of having a test-ready application to show to the heads of the project, and demonstrating G2's capabilities, by late 2014 will require hard work and intense study and understanding of not only the programming aspect but also the physical phenomena we want to model, observe, and control.

  3. CORE AND EDGE ASPECTS OF QUIESCENT DOUBLE BARRIER OPERATION ON DIII-D.WITH RELEVANCE TO CRITICAL ITB PHYSICS ISSUES

    SciTech Connect

    DOYLE,EJ; CASPER,TA; BURRELL,KH; GREENFIELD,CM; WEST,WP; BUDNY,RV; DeBOO,JC; GAROFALO,AM; GOHIL,P; GROEBNER,RJ; HYATT,AW; JACKSON,GL; JERINGAN,TC; KINSEY,JE; LAO,LL; LASNIER,CJ; LEBOEUF,JN; LUCE,TC; MAKOWSKI,MA; McKEE,GR

    2003-03-01

    OAK-B135 Recent results from DIII-D address critical internal transport barrier (ITB) research issues relating to sustainability, impurity accumulation and ITB control, and have also demonstrated successful application of general profile control tools. In addition, substantial progress has been made in understanding the physics of the Quiescent Double Barrier (QDB) regime, increasing the demonstrating operating space for the regime and improving performance. Highlights include: (1) a clear demonstration of q-profile modification using electron cyclotron current drive (ECCD); (2) successful use of localized profile control using electron cyclotron heating (ECH) or ECCD to reduce central high-Z impurity accumulation associated with density peaking; (3) theory-based modeling codes are now being used to design experiments; (4) the operating space for Quiescent H-mode (QH-mode) has been substantially broadened, in particular higher density operation has been achieved; (5) absolute ({beta} 3.8%, neutron rate S{sub n} {le} 5.5 x 10{sup 15} s{sup -1}) and relative ({beta}{sub N}H{sub 89} = 7 for 10 {tau}{sub E}) performance has been increased; (6) with regard to sustainment, QDB plasmas have been run for 3.8 s or 26 {tau}{sub E}. These results emphasize that it is possible to produce sustained high quality H-mode performance with an edge localized mode (ELM)-free edge, directly addressing a major issue in fusion research, of how to ameliorate or eliminate ELM induced pulsed divertor particle and heat loads.

  4. The Pill vs. the Sword: Additional Considerations Comment on "The Pill Is Mightier Than the Sword".

    PubMed

    Lottes, Ilsa L

    2015-01-01

    In this paper, I present additional information for policy-makers and researchers to consider in response to the view proposed by Potts et al that "the pill is mightier than the sword." I identify states with both high rates of terrorism and a youth bulge and discuss correlates of both these societal characteristics. The research examined supports the view that factors other than access to family planning are more important in facilitating terrorism. PMID:26673473

  5. Close view of statue showing the right side (with sword) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close view of statue showing the right side (with sword) and base - U.S. Capitol, Statue of Freedom, Intersection of North, South, & East Capitol Streets & Capitol Mall, Washington, District of Columbia, DC

  6. The Double-edged Impact of Platinum Nano-Deposits on the Durability of Polymer Electrolyte Membranes -- A Theoretical Study

    NASA Astrophysics Data System (ADS)

    Eslamibidgoli, Mohammad Javad; Melchy, Pierre-Éric Alix; Roudgar, Ata; Eikerling, Michael H.

    2014-03-01

    The attack of oxygen radicals is one of the main sources of chemical degradation in the polymer electrolyte membranes (PEM) of polymer electrolyte fuel cells. In this context, Pt in the membrane (PITM) that originates from Pt degradation in the cathode catalyst layer plays a double-edged role: surface reactions at PITM could facilitate the formation or quenching of radicals. The balance of these processes depends on the local electrochemical conditions, determined by thermodynamic parameters and local composition of the PEM. The objective of this work is to explore the equilibrium and kinetics of radical reactions at PITM as a function of local PEM conditions. We first determine the potential distribution of PITM based on a continuum model of crossover of reactant gases coupled with their local electrochemical reactions at Pt. Secondly, we determine the surface state of Pt for the given local potential using relevant experimental data and kinetic models of surface reactions at Pt. Lastly, we use this information as input for ab initio calculations at the DFT level of specific processes involved in the radical balance at the Pt | water interface. Ballard Power Systems, Automotive Partnership Canada.

  7. Double-edged-sword effect of IL-1β on the osteogenesis of periodontal ligament stem cells via crosstalk between the NF-κB, MAPK and BMP/Smad signaling pathways

    PubMed Central

    Mao, C-y; Wang, Y-g; Zhang, X; Zheng, X-y; Tang, T-t; Lu, E-y

    2016-01-01

    Microenvironmental conditions can interfere with the functional role and differentiation of mesenchymal stem cells (MSCs). Recent studies suggest that an inflammatory microenvironment can significantly impact the osteogenic potential of periodontal ligament stem cells (PDLSCs), but the precise effects and mechanisms involved remain unclear. Here, we show for the first time that interleukin-1β (IL-1β) has dual roles in the osteogenesis of PDLSCs at concentrations ranging from physiologically healthy levels to those found in chronic periodontitis. Low doses of IL-1β activate the BMP/Smad signaling pathway to promote the osteogenesis of PDLSCs, but higher doses of IL-1β inhibit BMP/Smad signaling through the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, inhibiting osteogenesis. These results demonstrate that crosstalk between NF-κB, MAPK and BMP/Smad signaling mediates this dual effect of IL-1β on PDLSCs. We also show that the impaired osteogenesis of PDLSCs results in more inflammatory cytokines and chemokines being released, inducing the chemotaxis of macrophages, which further clarifies the role of PDLSCs in the pathogenesis of periodontitis. PMID:27415426

  8. Double-edged-sword effect of IL-1β on the osteogenesis of periodontal ligament stem cells via crosstalk between the NF-κB, MAPK and BMP/Smad signaling pathways.

    PubMed

    Mao, C-Y; Wang, Y-G; Zhang, X; Zheng, X-Y; Tang, T-T; Lu, E-Y

    2016-01-01

    Microenvironmental conditions can interfere with the functional role and differentiation of mesenchymal stem cells (MSCs). Recent studies suggest that an inflammatory microenvironment can significantly impact the osteogenic potential of periodontal ligament stem cells (PDLSCs), but the precise effects and mechanisms involved remain unclear. Here, we show for the first time that interleukin-1β (IL-1β) has dual roles in the osteogenesis of PDLSCs at concentrations ranging from physiologically healthy levels to those found in chronic periodontitis. Low doses of IL-1β activate the BMP/Smad signaling pathway to promote the osteogenesis of PDLSCs, but higher doses of IL-1β inhibit BMP/Smad signaling through the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, inhibiting osteogenesis. These results demonstrate that crosstalk between NF-κB, MAPK and BMP/Smad signaling mediates this dual effect of IL-1β on PDLSCs. We also show that the impaired osteogenesis of PDLSCs results in more inflammatory cytokines and chemokines being released, inducing the chemotaxis of macrophages, which further clarifies the role of PDLSCs in the pathogenesis of periodontitis. PMID:27415426

  9. The role of T helper (TH)17 cells as a double-edged sword in the interplay of infection and autoimmunity with a focus on xenobiotic-induced immunomodulation.

    PubMed

    Hemdan, Nasr Y A; Abu El-Saad, Ahmed M; Sack, Ulrich

    2013-01-01

    Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity and cancer, especially when accompanied by inflammation-triggered persistent sensitization. This perception is learned from experimental models of infection and epidemiologic studies and clearly underscores the interplay of exposure to such immunomodulatory elements with pre- or postexposure infectious events. Further, the TH17 cell subset, known to be associated with a growing list of autoimmune manifestations, may be the "superstar" at the interface of xenobiotic exposure and autoimmunity. In this review, the most recently established links to this nomination are short-listed to create a framework to better understand new insights into TH17's contributions to autoimmunity. PMID:24151516

  10. Double conical crystal x-ray spectrometer for high resolution ultrafast x-ray absorption near-edge spectroscopy of Al K edge

    NASA Astrophysics Data System (ADS)

    Levy, A.; Dorchies, F.; Fourment, C.; Harmand, M.; Hulin, S.; Santos, J. J.; Descamps, D.; Petit, S.; Bouillaud, R.

    2010-06-01

    An x-ray spectrometer devoted to dynamical studies of transient systems using the x-ray absorption fine spectroscopy technique is presented in this article. Using an ultrafast laser-induced x-ray source, this optical device based on a set of two potassium acid phthalate conical crystals allows the extraction of x-ray absorption near-edge spectroscopy structures following the Al absorption K edge. The proposed experimental protocol leads to a measurement of the absorption spectra free from any crystal reflectivity defaults and shot-to-shot x-ray spectral fluctuation. According to the detailed analysis of the experimental results, a spectral resolution of 0.7 eV rms and relative fluctuation lower than 1% rms are achieved, demonstrated to be limited by the statistics of photon counting on the x-ray detector.

  11. Edward's sword? - A non-destructive study of a medieval king's sword

    SciTech Connect

    Segebade, Chr.

    2013-04-19

    Non-destructive and instrumental methods including photon activation analysis were applied in an examination of an ancient sword. It was tried to find indication of forgery or, if authentic, any later processing and alteration. Metal components of the hilt and the blade were analysed by instrumental photon activation. Non-destructive metallurgical studies (hardness measurements, microscopic microstructure analysis) are briefly described, too. The results of these investigations did not yield indication of non-authenticity. This stood in agreement with the results of stylistic and scientific studies by weapon experts.

  12. Edward's sword? - A non-destructive study of a medieval king's sword

    NASA Astrophysics Data System (ADS)

    Segebade, Chr.

    2013-04-01

    Non-destructive and instrumental methods including photon activation analysis were applied in an examination of an ancient sword. It was tried to find indication of forgery or, if authentic, any later processing and alteration. Metal components of the hilt and the blade were analysed by instrumental photon activation. Non-destructive metallurgical studies (hardness measurements, microscopic microstructure analysis) are briefly described, too. The results of these investigations did not yield indication of non-authenticity. This stood in agreement with the results of stylistic and scientific studies by weapon experts.

  13. Edge Stability and Performance of the ELM-Free Quiescent H-Mode and the Quiescent Double Barrier Mode on DIII-D

    SciTech Connect

    West, W P; Burrell, K H; Casper, T A; . Doyle, E J; Snyder, P B; Gohil, P; Lao, L L; Lasnier, C J; Leonard, A W; Nave, M F; Osborne, T H; Thomas, D M; Wang, G; Zeng, L

    2004-12-03

    The quiescent H (QH) mode, an edge localized mode (ELM)-free, high-confinement mode, combines well with an internal transport barrier to form quiescent double barrier (QDB) stationary state, high performance plasmas. The QH-mode edge pedestal pressure is similar to that seen in ELMing phases of the same discharge, with similar global energy confinement. The pedestal density in early ELMing phases of strongly pumped counter injection discharges drops and a transition to QH-mode occurs, leading to lower calculated edge bootstrap current. Plasmas current ramp experiment and ELITE code modeling of edge stability suggest that QH-modes lie near an edge current stability boundary. At high triangularity, QH-mode discharges operate at higher pedestal density and pressure, and have achieved ITER level values of {beta}{sub PED} and {nu}*. The QDB achieves performance of {alpha}{sub N}H{sub 89} {approx} 7 in quasi-stationary conditions for a duration of 10 tE, limited by hardware. Recently we demonstrated stationary state QDB discharges with little change in kinetic and q profiles (q{sub 0} > 1) for 2 s, comparable to ELMing ''hybrid scenarios'', yet without the debilitating effects of ELMs. Plasma profile control tools, including electron cyclotron heating and current drive and neutral beam heating, have been demonstrated to control simultaneously the q profile development, the density peaking, impurity accumulation and plasma beta.

  14. Crack growth behavior under creep-fatigue conditions using compact and double edge notch tension-compression specimens

    NASA Astrophysics Data System (ADS)

    Narasimha Chary, Santosh Balaji

    The American Society for Testing and Materials (ASTM) has recently developed a new standard for creep-fatigue crack growth testing, E 2760-10, that supports testing compact specimens, C(T), under load controlled conditions. C(T) specimens are commonly used for fatigue and creep-fatigue crack growth testing under constant-load-amplitude conditions. The use of these specimens is limited to positive load ratios. They are also limited in the amount of crack growth data that can be developed at high stress intensity values due to accumulation of plastic and/or creep strains leading to ratcheting in the specimen. Testing under displacement control can potentially address these shortcomings of the load-controlled tests for which the C(T) geometry is unsuitable. A double edge notch tension-compression, DEN(T-C), specimen to perform displacement controlled creep-fatigue crack growth testing is developed and optimized with the help of finite element and boundary element analyses. Accurate expressions for estimating the fracture mechanics crack tip parameters such as the stress intensity parameter, K, the crack mouth opening displacement (CMOD), and the load-line displacement (LLD) are developed over a wide range of crack sizes for the DEN(T-C) specimen. A new compliance relationship for use in experimental testing has been developed by using the compliance form available in ASTM E-647 standard. Experimentally determined compliance value compared well with the new relation for C15 steel (AISI 1015) and P91 steel tested at room and elevated temperature conditions respectively. Fatigue crack growth rate data generated using the DEN(T-C) specimens on the two metallic materials are in good agreement with the data generated using standard compact specimens; thus validating the stress-intensity factor and the compliance equation for the double edge notch tension-compression specimen. The testing has shown that the DEN(T-C) specimen is prone to crack asymmetry issues. Through

  15. Covenants with Weak Swords: ISO 14001 and Facilities' Environmental Performance

    ERIC Educational Resources Information Center

    Potoski, Matthew; Prakash, Aseem

    2005-01-01

    Voluntary environmental programs are codes of progressive environmental conduct that firms pledge to adopt. This paper investigates whether ISO 14001, a voluntary program with a weak sword--a weak monitoring and sanctioning mechanism--can mitigate shirking and improve participants' environmental performance. Sponsored by the International…

  16. Exponential Increase in Relative Biological Effectiveness Along Distal Edge of a Proton Bragg Peak as Measured by Deoxyribonucleic Acid Double-Strand Breaks

    PubMed Central

    Cuaron, John J.; Chang, Chang; Lovelock, Michael; Higginson, Daniel S.; Mah, Dennis; Cahlon, Oren; Powell, Simon

    2016-01-01

    Purpose To quantify the relative biological effectiveness (RBE) of the distal edge of the proton Bragg peak, using an in vitro assay of DNA double-strand breaks (DSBs). Methods and Materials U2OS cells were irradiated within the plateau of a spread-out Bragg peak and at each millimeter position along the distal edge using a custom slide holder, allowing for simultaneous measurement of physical dose. A reference radiation signal was generated using photons. The DNA DSBs at 3 hours (to assess for early damage) and at 24 hours (to assess for residual damage and repair) after irradiation were measured using the γH2AX assay and quantified via flow cytometry. Results were confirmed with clonogenic survival assays. A detailed map of the RBE as a function of depth along the Bragg peak was generated using γH2AX measurements as a biological endpoint. Results At 3 hours after irradiation, DNA DSBs were higher with protons at every point along the distal edge compared with samples irradiated with photons to similar doses. This effect was even more pronounced after 24 hours, indicating that the impact of DNA repair is less after proton irradiation relative to photons. The RBE demonstrated an exponential increase as a function of depth and was measured to be as high as 4.0 after 3 hours and as high as 6.0 after 24 hours. When the RBE-corrected dose was plotted as a function of depth, the peak effective dose was extended 2-3 mm beyond what would be expected with physical measurement. Conclusions We generated a highly comprehensive map of the RBE of the distal edge of the Bragg peak, using a direct assay of DNA DSBs in vitro. Our data show that the RBE of the distal edge increases with depth and is significantly higher than previously reported estimates. PMID:27084629

  17. Characterization of an Indian sword: classic and noninvasive methods of investigation in comparison

    NASA Astrophysics Data System (ADS)

    Barzagli, E.; Grazzi, F.; Williams, A.; Edge, D.; Scherillo, A.; Kelleher, J.; Zoppi, M.

    2015-04-01

    The evolution of metallurgy in history is one of the most interesting topics in Archaeometry. The production of steel and its forging methods to make tools and weapons are topics of great interest in the field of the history of metallurgy. In the production of weapons, we find almost always the highest level of technology. These were generally produced by skilled craftsmen who used the best quality materials available. Indian swords are an outstanding example in this field and one of the most interesting classes of objects for the study of the evolution of metallurgy. This work presents the study of a Shamsheer (a sword with a curved blade with single edge) made available by the Wallace Collection in London. The purpose of this study was to determine the composition, the microstructure, the level and the direction of residual strain and their distribution in the blade. We have used two different approaches: the classical one (metallography) and a nondestructive technique (neutron diffraction): In this way, we can test differences and complementarities of these two techniques. To obtain a good characterization of artifacts studied by traditional analytical methods, an invasive approach is required. However, the most ancient objects are scarce in number, and the most interesting ones are usually in an excellent state of conservation, so it is unthinkable to apply techniques with a destructive approach. The analysis of blades that has been performed by metallographic microscopy has demonstrated the specificity of the production of this type of steel. However, metallographic analysis can give only limited information about the structural characteristics of these artifacts of high quality, and it is limited to the sampled areas. The best approach for nondestructive analysis is therefore to use neutron techniques.

  18. Casting Simulation of an Austrian Bronze Age Sword Hilt

    NASA Astrophysics Data System (ADS)

    Pola, Annalisa; Mödlinger, Marianne; Piccardo, Paolo; Montesano, Lorenzo

    2015-07-01

    Bronze Age swords with a metal hilt can be considered the peak of Bronze Age casting technologies. To reconstruct the casting techniques used more than 3000 years ago, a metal hilted sword of the Schalenknauf type from Lower Austria was studied with the aid of macroscopic analyses and simulation of mold filling and casting solidification. A three-dimensional model of the hilt was created based on optical scanner measurements performed on a hilt recently discovered during archaeological excavations. Three different configurations of the gating system were considered, two on the pommel disk and one on the knob, and the effect of its location on the formation of casting defects was investigated. Three-dimensional computed tomography was used to detect internal defects, such as gas and shrinkage porosity, which were then compared with those calculated by simulation. The best match between actual and predicted hilt quality demonstrated the location of the gating system, which turned out to be on the pommel disk.

  19. Simulating Terrestrial Gamma-ray Flashes using SWORD (Invited)

    NASA Astrophysics Data System (ADS)

    Gwon, C.; Grove, J.; Dwyer, J. R.; Mattson, K.; Polaski, D.; Jackson, L.

    2013-12-01

    We report on simulations of the relativistic feedback discharges involved with the production of terrestrial gamma-ray flashes (TGFs). The simulations were conducted using Geant4 using the SoftWare for the Optimization of Radiation Detectors (SWORD) framework. SWORD provides a graphical interface for setting up simulations in select high-energy radiation transport engines. Using Geant4, we determine avalanche length, the energy spectrum of the electrons and gamma-rays as they leave the field region, and the feedback factor describing the degree to which the production of energetic particles is self-sustaining. We validate our simulations against previous work in order to determine the reliability of our results. This work is funded by the Office of Naval Research.

  20. Position and flux stabilization of X-ray beams produced by double-crystal monochromators for EXAFS scans at the titanium K-edge.

    PubMed

    van Silfhout, Roelof; Kachatkou, Anton; Groppo, Elena; Lamberti, Carlo; Bras, Wim

    2014-03-01

    The simultaneous and active feedback stabilization of X-ray beam position and monochromatic beam flux during EXAFS scans at the titanium K-edge as produced by a double-crystal monochromator beamline is reported. The feedback is generated using two independent feedback loops using separate beam flux and position measurements. The flux is stabilized using a fast extremum-searching algorithm that is insensitive to changes in the synchrotron ring current and energy-dependent monochromator output. Corrections of beam height are made using an innovative transmissive beam position monitor instrument. The efficacy of the feedback stabilization method is demonstrated by comparing the measurements of EXAFS spectra on inhomogeneous diluted Ti-containing samples with and without feedback applied. PMID:24562562

  1. Further aspects on J-evaluation demonstrated with EDM notched round bars and double-edged plates between 300 and 7 K

    NASA Astrophysics Data System (ADS)

    Nyilas, A.; Nishimura, A.; Obst, B.

    2002-05-01

    Based on recent experiences with respect to JETT (J_-E_valuation on T_ensile T_est) several materials were measured to investigate the potential of this novel technique with the aim to determine the fracture toughness of materials. The investigated materials covered a wide field of toughness levels ranging from ˜2 MPa√m to ˜300 MPa√m. These materials were as follows; OFHC annealed copper, CuNiSi, sintered NdFeB, FeCo, 9Ni steel, Al 6061-T6, wrought 316LN, and modified Type 316LN cast steels. The tests comprised measurements of EDM notched round bars as well as double edged flat tensile specimens between 300 K and 7 K. Wherever possible the tests were cross checked with ASTM standard compact tension or single edged notched specimens using the standard procedures. Main attention was paid to seek a solution towards a realistic integration path focusing the materials fracture point, comprising tests with high ductility and medium toughness materials represented by copper and copper alloys. Scanning electron microscopic investigations at the notch tip of loaded and subsequently unloaded specimens at the maximum load position could reveal the crack initiation at the notch tip immediately after the start of necking. A concept was driven for reliable evaluation and estimation of the materials critical J and the related fracture toughness.

  2. Precipitation of sword bean proteins by heating and addition of magnesium chloride in a crude extract.

    PubMed

    Nishizawa, Kaho; Masuda, Tetsuya; Takenaka, Yasuyuki; Masui, Hironori; Tani, Fumito; Arii, Yasuhiro

    2016-08-01

    Sword bean (Canavalia gladiata) seeds are a traditional food in Asian countries. In this study, we aimed to determine the optimal methods for the precipitation of sword bean proteins useful for the food development. The soaking time for sword beans was determined by comparing it with that for soybeans. Sword bean proteins were extracted from dried seeds in distilled water using novel methods. We found that most proteins could be precipitated by heating the extract at more than 90 °C. Interestingly, adding magnesium chloride to the extract at lower temperatures induced specific precipitation of a single protein with a molecular weight of approximately 48 kDa. The molecular weight and N-terminal sequence of the precipitated protein was identical to that of canavalin. These data suggested that canavalin was precipitated by the addition of magnesium chloride to the extract. Our results provide important insights into the production of processed foods from sword bean. PMID:27022983

  3. Presbyopia compensation with a light sword optical element

    NASA Astrophysics Data System (ADS)

    Ares Garcia, J.; Bará, S.; Gomez Garcia, M.; Jaroszewicz, Z.; Kołodziejczyk, A.; Petelczyc, K.

    2008-12-01

    This paper presents numerical analysis of imaging quality of a refractive light sword optical element (LSOE). For comparison other optical imaging elements with extended focal depth, such as the bifocal lens, the trifocal lens, the forward axicon and the backward axicon, were also checked. The parameters of all elements were assumed according to the human eye parameters in order to check possibilities of presbyopia compensation. Obtained results allow to state that the LSOE is a promising solution for compensation of insufficient human eye accommodation.

  4. Role of disulfide linkage in action of bis(dialkylaminethiocarbonyl)disulfides as potent double-Edged microbicidal spermicide: Design, synthesis and biology.

    PubMed

    Lal, Nand; Jangir, Santosh; Bala, Veenu; Mandalapu, Dhanaraju; Sarswat, Amit; Kumar, Lalit; Jain, Ashish; Kumar, Lokesh; Kushwaha, Bhavana; Pandey, Atindra K; Krishna, Shagun; Rawat, Tara; Shukla, Praveen K; Maikhuri, Jagdamba P; Siddiqi, Mohammad I; Gupta, Gopal; Sharma, Vishnu L

    2016-06-10

    Trichomoniasis and candidiasis are amongst the most common morbidity-causing reproductive tract infections, generally treated by Metronidazole and Fluconazole respectively. Poor vaginal efficacy, drug-resistance and non-spermicidal nature limit their use as topical microbicidal contraceptives. Bis(dialkylaminethiocarbonyl)disulfides (4-38) were designed as dually active, non-surfactant molecules capable of eliminating Trichomonas vaginalis and Candida strains as well as irreversibly immobilizing 100% human sperm instantly, at doses non-cytotoxic to human cervical epithelial cells and vaginal microflora in vitro. Compounds 12, 16, 17 were fifty times more active than nonoxynol-9, OTC vaginal spermicide, and compounds 12 and 17 have shown remarkable in vivo activity in rabbit model. Most promising compound 17 has shown promise for further development as a double-edged vaginal microbicide due to their improved activity and safety along with notable in vivo trichomonicidal activity. Role of disulfide group was established by loss of spermicidal activity on chemical modifications (39-56). These disulfides might be targeting thiol groups present over cell membrane of human sperm and Trichomonas as shown by fluorescence labeling of free thiols. PMID:27084496

  5. Non-specificity of ethylene inhibitors: 'double-edged' tools to find out new targets involved in the root morphogenetic programme.

    PubMed

    Le Deunff, E; Lecourt, J

    2016-05-01

    In the last decade, genetic and pharmacological approaches have been used to explore ethylene biosynthesis and perception in order to study the role of ethylene and ethylene/auxin interaction in root architecture development. However, recent findings with pharmacological approaches highlight the non-specificity of commonly used inhibitors. This suggests that caution is required for interpreting these studies and that the use of pharmacological agents is a 'double-edged' tool. On one hand, non-specific effects make interpretation difficult unless other experiments, such as with different mutants or with multiple diversely acting chemicals, are conducted. On the other hand, the non-specificity of inhibitors opens up the possibility of uncovering some ligands or modulators of new receptors such as plant glutamate-like receptors and importance of some metabolic hubs in carbon and nitrogen metabolism such as the pyridoxal phosphate biosynthesis involved in the regulation of the root morphogenetic programme. Identification of such targets is a critical issue to improve the efficiency of absorption of macronutrients in relation to root the morphogenetic programme. PMID:26434926

  6. External-RBS, PIXE and NRA analysis for ancient swords

    NASA Astrophysics Data System (ADS)

    Santos, Hellen C.; Added, Nemitala; Silva, Tiago F.; Rodrigues, C. L.

    2015-02-01

    Elemental composition of the steel of two ancient swords (Japanese and Damascus from a private collection) was characterized using in air IBA techniques. Our results contribute for the understanding the processes of manufacturing (hammering and quenching) and surface treatments applied in these swords. The Particle Induced X-ray Emission (PIXE) measurements along the Damascus blade allowed to identify and to trace a superficial concentration profile for the elements such Cr, Mn, Fe, Ni, Cu, Zn and As, while results for the Japanese blade showed only the presence of iron. The carbon content on the surface was also investigated using a resonant region in the Elastic Backscattering Spectrometry (EBS) measurements and the results have shown a slightly difference between the surfaces under investigation. In order to investigate the nitrogen content on surface, that could explain the hardening process, we used Nuclear Reaction Analysis (NRA) and the results shown that nitrogen content was under our detection limit for the technique (0.3% in mass). The measurements of PIXE, NRA and EBS were taken using the external beam setup installed at Lamfi - São Paulo/Brazil, the latter being successfully implemented for the first time in this facility.

  7. Female preference for swords in Xiphophorus helleri reflects a bias for large apparent size

    PubMed Central

    Rosenthal, Gil G.; Evans, Christopher S.

    1998-01-01

    Swordtail fish (Poeciliidae: genus Xiphophorus) are a paradigmatic case of sexual selection by sensory exploitation. Female preference for males with a conspicuous “sword” ornament is ancestral, suggesting that male morphology has evolved in response to a preexisting bias. The perceptual mechanisms underlying female mate choice have not been identified, complicating efforts to understand the selection pressures acting on ornament design. We consider two alternative models of receiver behavior, each consistent with previous results. Females could respond either to specific characteristics of the sword or to more general cues, such as the apparent size of potential mates. We showed female swordtails a series of computer-altered video sequences depicting a courting male. Footage of an intact male was preferred strongly to otherwise identical sequences in which portions of the sword had been deleted selectively, but a disembodied courting sword was less attractive than an intact male. There was no difference between responses to an isolated sword and to a swordless male of comparable length, or between an isolated sword and a homogenous background. Female preference for a sworded male was abolished by enlarging the image of a swordless male to compensate for the reduction in length caused by removing the ornament. This pattern of results is consistent with mate choice being mediated by a general preference for large males rather than by specific characters. Similar processes may account for the evolution of exaggerated traits in other systems. PMID:9539754

  8. Decoupling Edge Versus Bulk Conductance in the Trivial Regime of an InAs/GaSb Double Quantum Well Using Corbino Ring Geometry.

    PubMed

    Nguyen, Binh-Minh; Kiselev, Andrey A; Noah, Ramsey; Yi, Wei; Qu, Fanming; Beukman, Arjan J A; de Vries, Folkert K; van Veen, Jasper; Nadj-Perge, Stevan; Kouwenhoven, Leo P; Kjaergaard, Morten; Suominen, Henri J; Nichele, Fabrizio; Marcus, Charles M; Manfra, Michael J; Sokolich, Marko

    2016-08-12

    A Corbino ring geometry is utilized to analyze edge and bulk conductance of InAs/GaSb quantum well structures. We show that edge conductance exists in the trivial regime of this theoretically predicted topological system with a temperature-insensitive linear resistivity per unit length in the range of 2  kΩ/μm. A resistor network model of the device is developed to decouple the edge conductance from the bulk conductance, providing a quantitative technique to further investigate the nature of this trivial edge conductance, conclusively identified here as being of n type. PMID:27563999

  9. Decoupling Edge Versus Bulk Conductance in the Trivial Regime of an InAs /GaSb Double Quantum Well Using Corbino Ring Geometry

    NASA Astrophysics Data System (ADS)

    Nguyen, Binh-Minh; Kiselev, Andrey A.; Noah, Ramsey; Yi, Wei; Qu, Fanming; Beukman, Arjan J. A.; de Vries, Folkert K.; van Veen, Jasper; Nadj-Perge, Stevan; Kouwenhoven, Leo P.; Kjaergaard, Morten; Suominen, Henri J.; Nichele, Fabrizio; Marcus, Charles M.; Manfra, Michael J.; Sokolich, Marko

    2016-08-01

    A Corbino ring geometry is utilized to analyze edge and bulk conductance of InAs /GaSb quantum well structures. We show that edge conductance exists in the trivial regime of this theoretically predicted topological system with a temperature-insensitive linear resistivity per unit length in the range of 2 k Ω /μ m . A resistor network model of the device is developed to decouple the edge conductance from the bulk conductance, providing a quantitative technique to further investigate the nature of this trivial edge conductance, conclusively identified here as being of n type.

  10. Microstructural Features in Corroded Celtic Iron Age Sword Blades

    NASA Astrophysics Data System (ADS)

    Ghiara, G.; Piccardo, P.; Campodonico, S.; Carnasciali, M. M.

    2014-05-01

    Archaeological artefacts made from iron and steel are often of critical importance for archaeometallurgical studies, which aim to understand the process of manufacturing, as the nearly complete alloy mineralization does not allow for any type of metallographic interpretation. In this study, three Iron Age sword blades dated from the second century BC (LaTène B2/D1) found in the archaeological site of Tintignac (Commune de Naves, Corrèze, France), were investigated. A multianalytical approach was employed to acquire a complete range of data from the partially or totally corroded objects. Analyses were carried out with the use of light optical microscopy, micro Raman spectroscopy, and scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy (EDXS). Remnants of metallographic features—ghost microstructure—in the corrosion layers of the blades were observed, allowing for a partial reconstruction of the manufacturing process.

  11. A comparison of antioxidative and anti-inflammatory activities of sword beans and soybeans fermented with Bacillus subtilis.

    PubMed

    Han, Seon Su; Hur, Sun Jin; Lee, Si Kyung

    2015-08-01

    This study was conducted to determine the antioxidative and anti-inflammatory activities of non-fermented or Bacillus subtilis-fermented soybeans and sword beans (red and white). The total flavonoid content in both sword bean types was higher (1.9-2.5-fold) than that in soybeans. The total phenolic content in fermented red sword beans was 2.5-fold greater than that in non-fermented red sword beans. HPLC profiles revealed that gallic acid, methyl gallate, and ellagic acid were major phenolic components of non-fermented/fermented red sword beans. DPPH radical scavenging activity and ferric-reducing antioxidant power were higher in fermented red sword beans than in other beans. Non-fermented/fermented red sword beans had higher nitrite scavenging activity than butylated hydroxytoluene and non-fermented/fermented soybeans. The hyaluronidase inhibitory activity of non-fermented/fermented red sword beans was higher (1.5-2.6-fold) than that of non-fermented/fermented soybeans. These results suggest that B. subtilis-fermented sword beans are potential natural antioxidant sources and anti-inflammatory agents for the food industry. PMID:26149963

  12. Breaking Tolerance in Transgenic Mice Expressing the Human TSH Receptor A-Subunit: Thyroiditis, Epitope Spreading and Adjuvant as a ‘Double Edged Sword’

    PubMed Central

    McLachlan, Sandra M.; Aliesky, Holly A.; Chen, Chun-Rong; Chong, Gao; Rapoport, Basil

    2012-01-01

    Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a “double-edged sword”. On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the

  13. CHANG-ES. III. UGC 10288—An edge-on galaxy with a background double-lobed radio source

    SciTech Connect

    Irwin, Judith; Krause, Marita; Beck, Rainer; English, Jayanne; Murphy, Eric; Wiegert, Theresa; Heald, George; Walterbos, Rene; Rand, Richard J.; Porter, Troy E-mail: mkrause@mpifr-bonn.mpg.de E-mail: jayanne_english@umanitoba.ca E-mail: twiegert@astro.queensu.ca E-mail: rwalterb@nmsu.edu E-mail: tporter@stanford.edu

    2013-12-01

    This third paper in the Continuum Halos in Nearby Galaxies—an EVLA Survey (CHANG-ES) series shows the first results from our regular data taken with the Karl G. Jansky Very Large Array. The edge-on galaxy, UGC 10288, has been observed in the B, C, and D configurations at L band (1.5 GHz) and in the C and D configurations at C band (6 GHz) in all polarization products. We show the first spatially resolved images of this galaxy in these bands, the first polarization images, and the first composed image at an intermediate frequency (4.1 GHz) which has been formed from a combination of all data sets. A surprising new result is the presence of a strong, polarized, double-lobed extragalactic radio source (CHANG-ES A) almost immediately behind the galaxy and perpendicular to its disk. The core of CHANG-ES A has an optical counterpart (SDSS J161423.28–001211.8) at a photometric redshift of z {sub phot} = 0.39; the southern radio lobe is behind the disk of UGC 10288 and the northern lobe is behind the halo region. This background ''probe'' has allowed us to do a preliminary Faraday rotation analysis of the foreground galaxy, putting limits on the regular magnetic field and electron density in the halo of UGC 10288 in regions in which there is no direct detection of a radio continuum halo. We have revised the flux densities of the two sources individually as well as the star formation rate (SFR) for UGC 10288. The SFR is low (0.4-0.5 M {sub ☉} yr{sup –1}) and the galaxy has a high thermal fraction (44% at 6 GHz), as estimated using both the thermal and non-thermal SFR calibrations of Murphy et al. UGC 10288 would have fallen well below the CHANG-ES flux density cutoff, had it been considered without the brighter contribution of the background source. UGC 10288 shows discrete high-latitude radio continuum features, but it does not have a global radio continuum halo (exponential scale heights are typically ≈1 kpc averaged over regions with and without extensions

  14. The Blunt-Edged Sword: Genetic Explanations of Misbehavior Neither Mitigate Nor Aggravate Punishment

    PubMed Central

    Scurich, Nicholas; Appelbaum, Paul

    2015-01-01

    Links between genetic variants and negatively valenced behaviors have stimulated intense commentary about the implications for responsibility and punishment. Previous research has suggested that behavioral genetic evidence of a predisposition to negative behaviors has modest to no impact on mitigation of punishment, at least for serious crimes. Data are presented on the effect of such evidence in a representative sample of the general population (n=640) asked to consider 3 vignettes describing lesser offenses, dealt with in less-formal adjudicatory settings and in everyday life. Genetic explanations of behavior had no effect on the severity of the punishment selected in any case, in contrast to the egregiousness of the behavior and respondents’ beliefs in free-will. Public views of genetic influences on behavior may be less deterministic and more nuanced than is often thought, or genetic explanations may simply not have the salience for decision makers that is frequently attributed to them. PMID:27239327

  15. Scavenger Receptor-A (CD204): A Two-Edged Sword in Health and Disease

    PubMed Central

    Kelley, Jim L.; Ozment, Tammy R.; Li, Chuanfu; Schweitzer, John B.; Williams, David L.

    2014-01-01

    Scavenger receptor A (SR-A), also known as the macrophage scavenger receptor and cluster of differentiation 204 (CD204), plays roles in lipid metabolism, atherogenesis, and a number of metabolic processes. However, recent evidence points to important roles for SR-A in inflammation, innate immunity, host defense, sepsis, and ischemic injury. Herein, we review the role of SR-A in inflammation, innate immunity, host defense, sepsis, cardiac and cerebral ischemic injury, Alzheimer’s disease, virus recognition and uptake, bone metabolism, and pulmonary injury. Interestingly, SR-A is reported to be host protective in some disease states, but there is also compelling evidence that SR-A plays a role in the pathophysiology of other diseases. These observations of both harmful and beneficial effects of SR-A are discussed here in the framework of inflammation, innate immunity, and endoplasmic reticulum stress. PMID:24941076

  16. Dual Identity as a Two-Edged Sword: Identity Threat and Minority School Performance

    ERIC Educational Resources Information Center

    Baysu, Gulseli; Phalet, Karen; Brown, Rupert

    2011-01-01

    Some members of ethnic minority groups respond to identity threat in ways that are detrimental to their school career, while others persist despite an unwelcoming school environment. It was hypothesized that ethnic and national identities, as combined in "separated," "assimilated," or "dual identity" strategies, moderate consequences of identity…

  17. Hypothalamic Nitric Oxide in Hypoglycemia Detection and Counterregulation: A Two-Edged Sword

    PubMed Central

    Song, Zhentao; Vazirani, Reema P.; Beuve, Annie; Routh, Vanessa H.

    2011-01-01

    Abstract Hypoglycemia is the main complication for patients with type 1 diabetes mellitus receiving intensive insulin therapy. In addition to the obvious deleterious effects of acute hypoglycemia on brain function, recurrent episodes of hypoglycemia (RH) have an even more insidious effect. RH impairs the ability of the brain to detect and initiate an appropriate counterregulatory response (CRR) to restore euglycemia in response to subsequent hypoglycemia. Knowledge of mechanisms involved in hypoglycemia detection and counterregulation has significantly improved over the past 20 years. Glucose sensitive neurons (GSNs) in the ventromedial hypothalamus (VMH) may play a key role in the CRR. VMH nitric oxide (NO) production has recently been shown to be critical for both the CRR and glucose sensing by glucose-inhibited neurons. Interestingly, downstream effects of NO may also contribute to the impaired CRR after RH. In this review, we will discuss current literature regarding the molecular mechanisms by which VMH GSNs sense glucose. Putative roles of GSNs in the detection and initiation of the CRR will then be described. Finally, hypothetical mechanisms by which VMH NO production may both facilitate and subsequently impair the CRR will be discussed. Antioxid. Redox Signal. 14, 505–517. PMID:20518706

  18. Thyroid hormones: a triple-edged sword for life history transitions.

    PubMed

    Holzer, Guillaume; Laudet, Vincent

    2015-04-20

    Thyroid hormones have long been known for their metabolic role in humans and for triggering amphibian metamorphosis. More recently they have been uncovered as an important effector mechanism in seasonality. A recent study of salmon smoltification relates these various biological roles. PMID:25898108

  19. If SWORD Is the Answer, What Is the Question?: Use of the Simple Web-Service Offering Repository Deposit Protocol

    ERIC Educational Resources Information Center

    Lewis, Stuart; Hayes, Leonie; Newton-Wade, Vanessa; Corfield, Antony; Davis, Richard; Donohue, Tim; Wilson, Scott

    2009-01-01

    Purpose: The purpose of this paper is to describe the repository deposit protocol, Simple Web-service Offering Repository Deposit (SWORD), its development iteration, and some of its potential use cases. In addition, seven case studies of institutional use of SWORD are provided. Design/methodology/approach: The paper describes the recent…

  20. Stellar groups and clusters in the region of Orion's Sword

    NASA Astrophysics Data System (ADS)

    Vereshchagin, S. V.; Chupina, N. V.

    2010-09-01

    The region of Orion’s Sword with coordinates α = 83.79°, δ = -5.20° and a size of 1.0° × 2.5° is analyzed. We compiled a master catalog of stars observed in the optical, containing positions, proper motions, and UBV photometry for 1634 stars. Using the nearest-neighbor-distance technique, we subdivided the region into stellar groups with different numbers of members. The positions of five groups coincide with known clusters, and two groups coincide with aggregates of stars with Hα emission. We have identified groups with low membership that are moving away from the system. We also considered the kinematic structure of the groups using the AD-diagram method we developed earlier. Most of the stellar clusters and groups display similar kinematics, with the exception of the group OMC-2, which is moving toward its own apex. We also confirmed the existence of the kinematic star group 189 discovered earlier; its position is close to the cluster NGC 1977, and it is probably a component of its corona.

  1. Role of the double-strand break repair pathway in the maintenance of genomic stability

    PubMed Central

    Le Guen, Tangui; Ragu, Sandrine; Guirouilh-Barbat, Josée; Lopez, Bernard S

    2015-01-01

    DNA double-strand breaks (DSBs) are highly lethal lesions that jeopardize genome integrity. However, DSBs are also used to generate diversity during the physiological processes of meiosis or establishment of the immune repertoire. Therefore, DSB repair must be tightly controlled. Two main strategies are used to repair DSBs: homologous recombination (HR) and non-homologous end joining (NHEJ). HR is generally considered to be error-free, whereas NHEJ is considered to be error-prone. However, recent data challenge these assertions. Here, we present the molecular mechanisms involved in HR and NHEJ and the recently described alternative end-joining mechanism, which is exclusively mutagenic. Whereas NHEJ is not intrinsically error-prone but adaptable, HR has the intrinsic ability to modify the DNA sequence. Importantly, in both cases the initial structure of the DNA impacts the outcome. Finally, the consequences and applications of these repair mechanisms are discussed. Both HR and NHEJ are double-edged swords, essential for maintenance of genome stability and diversity but also able to generate genome instability. PMID:27308383

  2. Analysis of Crystallographic Structure of a Japanese Sword by the Pulsed Neutron Transmission Method

    NASA Astrophysics Data System (ADS)

    Kino, K.; Ayukawa, N.; Kiyanagi, Y.; Uchida, T.; Uno, S.; Grazzi, F.; Scherillo, A.

    We measured two-dimensional transmission spectra of pulsed neutron beams for a Japanese sword sample. Atom density, crystalline size, and preferred orientation of crystals were obtained using the RITS code. The position dependence of the atomic density is consistent with the shape of the sample. The crystalline size is very small and shows position dependence, which is understood by the unique structure of Japanese swords. The preferred orientation has strong position dependence. Our study shows the usefulness of the pulsed neutron transmission method for cultural metal artifacts.

  3. Tameshi-giri, or Japanese sword test-cutting: a historic overview.

    PubMed

    Kremer, Célia; Racette, Stéphanie; Schellenberg, Morgan; Chaltchi, Amir; Sauvageau, Anny

    2008-03-01

    The martial Japanese history is characterized by the development of a particular samurai sword known as the katana. It was believed that this sword was the reflection of the warrior's soul, and thus it had to be tested to estimate its sharpness, efficiency, and cutting ability. A variety of cutting tests was done on animals and bamboos, but some were also carried out on human beings. This technique was called tameshi-giri. Although the practice on human beings has since disappeared, the remaining cutting test records represent precious information about human body's resistance to sharp weapons. PMID:19749608

  4. The Orion Nebula: The Jewel in the Sword

    NASA Astrophysics Data System (ADS)

    2001-01-01

    Orion the Hunter is perhaps the best known constellation in the sky, well placed in the evening at this time of the year for observers in both the northern and southern hemispheres, and instantly recognisable. And for astronomers, Orion is surely one of the most important constellations, as it contains one of the nearest and most active stellar nurseries in the Milky Way, the galaxy in which we live. Here tens of thousands of new stars have formed within the past ten million years or so - a very short span of time in astronomical terms. For comparison: our own Sun is now 4,600 million years old and has not yet reached half-age. Reduced to a human time-scale, star formation in Orion would have been going on for just one month as compared to the Sun's 40 years. Just below Orion's belt, the hilt of his sword holds a great jewel in the sky, the beautiful Orion Nebula . Bright enough to be seen with the naked eye, a small telescope or even binoculars show the nebula to be a few tens of light-years' wide complex of gas and dust, illuminated by several massive and hot stars at its core, the famous Trapezium stars . However, the heart of this nebula also conceals a secret from the casual observer. There are in fact about one thousand very young stars about one million years old within the so-called Trapezium Cluster , crowded into a space less than the distance between the Sun and its nearest neighbour stars. The cluster is very hard to observe in visible light, but is clearly seen in the above spectacular image of this area ( ESO PR 03a/01 ), obtained in December 1999 by Mark McCaughrean (Astrophysical Institute Potsdam, Germany) and his collaborators [1] with the infrared multi-mode ISAAC instrument on the ESO Very Large Telescope (VLT) at Paranal (Chile). Many details are seen in the new ISAAC image ESO PR Photo 03b/01 ESO PR Photo 03b/01 [Preview - JPEG: 400 x 589 pix - 62k] [Normal - JPEG: 800 x 1178 pix - 648k] [Hires - JPEG: 1957 x 2881 pix - 2.7M] ESO PR Photo 03c

  5. Is the sword moss (Bryoxiphium) a preglacial Tertiary relict?

    PubMed

    Patiño, Jairo; Goffinet, Bernard; Sim-Sim, Manuela; Vanderpoorten, Alain

    2016-03-01

    The disjunction of floras between East Asia, Southeast North America, West North America, and Southwest Eurasia has been interpreted in terms of the fragmentation of a once continuous mixed mesophytic forest that occurred throughout the Northern Hemisphere due to the climatic and geological changes during the late Tertiary. The sword moss, Bryoxiphium, exhibits a distribution that strikingly resembles that of the mesophytic forest elements such as Liriodendron and is considered as the only living member of an early Tertiary flora in Iceland. These hypotheses are tested here using molecular dating analyses and ancestral area estimations. The results suggest that the extant range of Bryoxiphium results from the fragmentation of a formerly wider range encompassing North America and Southeast Asia about 10 million years ago. The split of continental ancestral populations is too recent to match with a continental drift scenario but is spatially and temporally remarkably congruent with that observed in Tertiary angiosperm relict species. The timing of the colonization of Iceland from Macaronesian ancestors, about two million years ago, is, however, incompatible with the hypothesis that Bryoxiphium is the only living member of an early Tertiary flora of the island. Alaska was recurrently colonized from East Asia. The ability of Bryoxiphium to overcome large oceanic barriers is further evidenced by its occurrence on remote oceanic archipelagos. In particular, Madeira was colonized twice independently from American and East Asian ancestors, respectively. The striking range disjunction of Bryoxiphium is interpreted in terms of its mating system, as the taxon exhibits a very singular pattern of spatial segregation of the sexes. PMID:26708122

  6. Study on the d state of platinum in Pt/SiO sub 2 and Na/Pt/SiO sub 2 catalysts under C double bond C hydrogenation conditions by X-ray absorption near-edge structure spectroscopy

    SciTech Connect

    Yoshitake, Hideaki; Iwasawa, Yasuhiro )

    1991-09-19

    The change in the d-electron density of platinum during D{sub 2} + CH{sub 2}{double bond}CHX reactions on Pt/SiO{sub 2} and Na/Pt/SiO{sub 2} catalysts and its influence on the catalysis were studied by X-ray absorption near-edge structure (XANES) spectroscopy, kinetics and FT-IR. It was demonstrated from the change of the white lines in XANES spectra at Pt L{sub 2} and L{sub 3} edges that CH{sub 2}{double bond}CHX (X = H, CH{sub 3}, COCH{sub 3}, CF{sub 3}, and CN) is adsorbed on the Pt surface and extracts the electrons of the d state. Hence, the deuterogenation rate is reduced as the value of Hammett's {sigma}{sub P} increases. The linear free energy relationship between the reaction rate and {sigma}{sub P} was observed for the deuterogenation of CH{sub 2}{double bond}CHX. The rate of ethene deuterogenation was promoted by Na{sub 2}O addition. The electron density of unoccupied d states of pt under vacuum decreased by Na{sub 2}O addition, indicating the electron donation from Na{sub 2}O addition. The electron density of unoccupied d states of Pt under vacuum decreased by Na{sub 2}O addition, indicating the electron donation from Na{sub 2}O addition. However, most of these additional electrons were observed to move to ethene under reaction conditions. The acceptor of the electrons was suggested by di-{sigma}-ethene by the shift of {upsilon}(C-H). The kinetic parameters are discussed in relation to the change in the d state of Pt as a function of {sigma}{sub P} and Na quantity.

  7. The Research Interview as Discourses Crossing Swords: The Researcher and Apprentice on Crossing Roads

    ERIC Educational Resources Information Center

    Tanggaard, Lene

    2007-01-01

    This article presents a conception of the qualitative research interview as discourses crossing swords. The article draws on examples showing how the researchers' view on learning is challenged by the interviewed apprentices. The apprentices do not assume learning in itself to be an important aspect of their lives. They consider the process of…

  8. Evelyn Waugh's "Sword of Honour": An Essay in the Philosophy of Art

    ERIC Educational Resources Information Center

    Link, Michael

    1978-01-01

    Evelyn Waugh, a controversial and notable author, wrote a war trilogy, Sword of Honour. Although the study of the philosophy of art is complicated, entailing serious problems for the philosopher, particularly with respect to literature, the aim of this essay is to evaluate Waugh's trilogy. Examines Waugh's use of literary elements and includes…

  9. Nb K-edge x-ray absorption investigation of the pressure induced amorphization in A-site deficient double perovskite La1/3NbO3.

    PubMed

    Marini, C; Noked, O; Kantor, I; Joseph, B; Mathon, O; Shuker, R; Kennedy, B J; Pascarelli, S; Sterer, E

    2016-02-01

    Nb K-edge x-ray absorption spectroscopy is utilized to investigate the changes in the local structure of the A-site deficient double perovskite La1/3NbO3 which undergoes a pressure induced irreversible amorphization. EXAFS results show that with increasing pressure up to 7.5 GPa, the average Nb-O bond distance decreases in agreement with the expected compression and tilting of the NbO6 octahedra. On the contrary, above 7.5 GPa, the average Nb-O bond distance show a tendency to increase. Significant changes in the Nb K-edge XANES spectrum with evident low energy shift of the pre-peak and the absorption edge is found to happen in La1/3NbO3 above 6.3 GPa. These changes evidence a gradual reduction of the Nb cations from Nb(5+) towards Nb(4+) above 6.3 GPa. Such a valence change accompanied by the elongation of the average Nb-O bond distances in the octahedra, introduces repulsion forces between non-bonding adjacent oxygen anions in the unoccupied A-sites. Above a critical pressure, the Nb reduction mechanism can no longer be sustained by the changing local structure and amorphization occurs, apparently due to the build-up of local strain. EXAFS and XANES results indicate two distinct pressure regimes having different local and electronic response in the La1/3NbO3 system before the occurence of the pressure induced amorphization at  ∼14.5 GPa. PMID:26742465

  10. Nb K-edge x-ray absorption investigation of the pressure induced amorphization in A-site deficient double perovskite La1/3NbO3

    NASA Astrophysics Data System (ADS)

    Marini, C.; Noked, O.; Kantor, I.; Joseph, B.; Mathon, O.; Shuker, R.; Kennedy, B. J.; Pascarelli, S.; Sterer, E.

    2016-02-01

    Nb K-edge x-ray absorption spectroscopy is utilized to investigate the changes in the local structure of the A-site deficient double perovskite La1/3NbO3 which undergoes a pressure induced irreversible amorphization. EXAFS results show that with increasing pressure up to 7.5 GPa, the average Nb-O bond distance decreases in agreement with the expected compression and tilting of the NbO6 octahedra. On the contrary, above 7.5 GPa, the average Nb-O bond distance show a tendency to increase. Significant changes in the Nb K-edge XANES spectrum with evident low energy shift of the pre-peak and the absorption edge is found to happen in La1/3NbO3 above 6.3 GPa. These changes evidence a gradual reduction of the Nb cations from Nb5+ towards Nb4+ above 6.3 GPa. Such a valence change accompanied by the elongation of the average Nb-O bond distances in the octahedra, introduces repulsion forces between non-bonding adjacent oxygen anions in the unoccupied A-sites. Above a critical pressure, the Nb reduction mechanism can no longer be sustained by the changing local structure and amorphization occurs, apparently due to the build-up of local strain. EXAFS and XANES results indicate two distinct pressure regimes having different local and electronic response in the La1/3NbO3 system before the occurence of the pressure induced amorphization at  ˜14.5 GPa.

  11. (De)localization and the mobility edges in a disordered double chain with long-range intrachain correlation and short-range interchain correlation

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Duan, Suqing; Zhang, Wei

    2012-06-01

    Correlation effects and phase transitions are central issues in current studies on disordered systems. In this paper, we study the electronic properties of a disordered double chain with long-range intrachain correlation and short-range interchain correlation. Based on detailed numerical calculations, finite size scaling analysis and empirical analytical calculations, we obtain a phase diagram containing rich physics due to the interplay among the disorder, short-range and long-range correlations. Besides the long-range correlation induced localization-delocalization transitions, we find both first-order and second-order quantum phase transitions on changing the short-range correlation. Interestingly, the localization may be suppressed by increasing the disorder strength in some parameter regime and the ‘anti-correlation’ leads to the most delocalized state. Our studies shine some light on the mechanism of the charge transport in DNA molecules, where both types of correlated disorders are present.

  12. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head

    PubMed Central

    Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  13. Sword-Like Trauma to the Shoulder with Open Head-Splitting Fracture of the Head.

    PubMed

    Panagopoulos, Andreas; Pantazis, Konstantinos; Iliopoulos, Ilias; Seferlis, Ioannis; Kokkalis, Zinon

    2016-01-01

    Head-splitting fractures occur as a result of violent compression of the head against the glenoid; the head splits and the tuberosities may remain attached to the fragments or split and separate. Isolated humeral head-splitting fractures are rare injuries. Favorable results with osteosynthesis can be difficult to achieve because of the very proximal location of the head fracture and associated poor vascularity. We present a case of a 67-year-old man who sustained a severe, sword-like trauma to his left shoulder after a road traffic accident with associated isolated open Gustilo-Anderson IIIA humeral head-splitting fracture. Bony union was achieved with minimal internal fixation but the clinical outcome deteriorated due to accompanying axillary nerve apraxia. To our knowledge, this type of sword-like injury with associated humeral head-split fracture has not previously been reported. PMID:27478665

  14. Edge Bioinformatics

    Energy Science and Technology Software Center (ESTSC)

    2015-08-03

    Edge Bioinformatics is a developmental bioinformatics and data management platform which seeks to supply laboratories with bioinformatics pipelines for analyzing data associated with common samples case goals. Edge Bioinformatics enables sequencing as a solution and forward-deployed situations where human-resources, space, bandwidth, and time are limited. The Edge bioinformatics pipeline was designed based on following USE CASES and specific to illumina sequencing reads. 1. Assay performance adjudication (PCR): Analysis of an existing PCR assay in amore » genomic context, and automated design of a new assay to resolve conflicting results; 2. Clinical presentation with extreme symptoms: Characterization of a known pathogen or co-infection with a. Novel emerging disease outbreak or b. Environmental surveillance« less

  15. Edge Bioinformatics

    SciTech Connect

    Lo, Chien-Chi

    2015-08-03

    Edge Bioinformatics is a developmental bioinformatics and data management platform which seeks to supply laboratories with bioinformatics pipelines for analyzing data associated with common samples case goals. Edge Bioinformatics enables sequencing as a solution and forward-deployed situations where human-resources, space, bandwidth, and time are limited. The Edge bioinformatics pipeline was designed based on following USE CASES and specific to illumina sequencing reads. 1. Assay performance adjudication (PCR): Analysis of an existing PCR assay in a genomic context, and automated design of a new assay to resolve conflicting results; 2. Clinical presentation with extreme symptoms: Characterization of a known pathogen or co-infection with a. Novel emerging disease outbreak or b. Environmental surveillance

  16. SoftWare for Optimization of Radiation Detectors, SWORD Version 5.0.

    SciTech Connect

    STRICKMAN, MARK S.

    2013-10-23

    Version 05 SoftWare for Optimization of Radiation Detectors (SWORD) is a framework to allow easy simulation and evaluation of radiation detection systems. It is targeted at system designers, who want to evaluate and optimize system parameters without actually building hardware first, at sponsors who need to evaluate proposed or actual system designs independent of the supplier, without having access to actual hardware, and at operators who want to use simulation to evaluate observed phenomena. SWORD is vertically integrated and modular. It allows users to define their own radiation detection instruments by building them from basic geometric “objects” and assigning those objects materials, detection, and/or radioactive emission properties. This process is accomplished by a CAD-like graphical user interface, in which objects may be defined, translated, rotated, grouped, arrayed, and/or nested to produce compound objects. In addition to providing the ability to build a detection system model from scratch, SWORD provides a library of “standard” detector design objects that can be used “as is” or modified by the user.

  17. Edge conduction in vacuum glazing

    SciTech Connect

    Simko, T.M.; Collins, R.E.; Beck, F.A.; Arasteh, D.

    1995-03-01

    Vacuum glazing is a form of low-conductance double glazing using in internal vacuum between the two glass sheets to eliminate heat transport by gas conduction and convection. An array of small support pillars separates the sheets; fused solder glass forms the edge seal. Heat transfer through the glazing occurs by radiation across the vacuum gap, conduction through the support pillars, and conduction through the bonded edge seal. Edge conduction is problematic because it affects stresses in the edge region, leading to possible failure of the glazing; in addition, excessive heat transfer because of thermal bridging in the edge region can lower overall window thermal performance and decrease resistance to condensation. Infrared thermography was used to analyze the thermal performance of prototype vacuum glazings, and, for comparison, atmospheric pressure superwindows. Research focused on mitigating the edge effects of vacuum glazings through the use of insulating trim, recessed edges, and framing materials. Experimentally validated finite-element and finite-difference modeling tools were used for thermal analysis of prototype vacuum glazing units and complete windows. Experimental measurements of edge conduction using infrared imaging were found to be in good agreement with finite-element modeling results for a given set of conditions. Finite-element modeling validates an analytic model developed for edge conduction.

  18. Sulfur and iron accumulation in three marine-archaeological shipwrecks in the Baltic Sea: The Ghost, the Crown and the Sword

    NASA Astrophysics Data System (ADS)

    Fors, Yvonne; Grudd, Håkan; Rindby, Anders; Jalilehvand, Farideh; Sandström, Magnus; Cato, Ingemar; Bornmalm, Lennart

    2014-02-01

    Sulfur and iron concentrations in wood from three 17th century shipwrecks in the Baltic Sea, the Ghost wreck, the Crown and the Sword, were obtained by X-ray fluorescence (XRF) scanning. In near anaerobic environments symbiotic microorganisms degrade waterlogged wood, reduce sulfate and promote accumulation of low-valent sulfur compounds, as previously found for the famous wrecks of the Vasa and Mary Rose. Sulfur K-edge X-ray absorption near-edge structure (XANES) analyses of Ghost wreck wood show that organic thiols and disulfides dominate, together with elemental sulfur probably generated by sulfur-oxidizing Beggiatoa bacteria. Iron sulfides were not detected, consistent with the relatively low iron concentration in the wood. In a museum climate with high atmospheric humidity oxidation processes, especially of iron sulfides formed in the presence of corroding iron, may induce post-conservation wood degradation. Subject to more general confirmation by further analyses no severe conservation concerns are expected for the Ghost wreck wood.

  19. Sulfur and iron accumulation in three marine-archaeological shipwrecks in the Baltic Sea: The Ghost, the Crown and the Sword

    PubMed Central

    Fors, Yvonne; Grudd, Håkan; Rindby, Anders; Jalilehvand, Farideh; Sandström, Magnus; Cato, Ingemar; Bornmalm, Lennart

    2014-01-01

    Sulfur and iron concentrations in wood from three 17th century shipwrecks in the Baltic Sea, the Ghost wreck, the Crown and the Sword, were obtained by X-ray fluorescence (XRF) scanning. In near anaerobic environments symbiotic microorganisms degrade waterlogged wood, reduce sulfate and promote accumulation of low-valent sulfur compounds, as previously found for the famous wrecks of the Vasa and Mary Rose. Sulfur K-edge X-ray absorption near-edge structure (XANES) analyses of Ghost wreck wood show that organic thiols and disulfides dominate, together with elemental sulfur probably generated by sulfur-oxidizing Beggiatoa bacteria. Iron sulfides were not detected, consistent with the relatively low iron concentration in the wood. In a museum climate with high atmospheric humidity oxidation processes, especially of iron sulfides formed in the presence of corroding iron, may induce post-conservation wood degradation. Subject to more general confirmation by further analyses no severe conservation concerns are expected for the Ghost wreck wood. PMID:24573214

  20. The Orion Nebula: The Jewel in the Sword

    NASA Astrophysics Data System (ADS)

    2001-01-01

    Orion the Hunter is perhaps the best known constellation in the sky, well placed in the evening at this time of the year for observers in both the northern and southern hemispheres, and instantly recognisable. And for astronomers, Orion is surely one of the most important constellations, as it contains one of the nearest and most active stellar nurseries in the Milky Way, the galaxy in which we live. Here tens of thousands of new stars have formed within the past ten million years or so - a very short span of time in astronomical terms. For comparison: our own Sun is now 4,600 million years old and has not yet reached half-age. Reduced to a human time-scale, star formation in Orion would have been going on for just one month as compared to the Sun's 40 years. Just below Orion's belt, the hilt of his sword holds a great jewel in the sky, the beautiful Orion Nebula . Bright enough to be seen with the naked eye, a small telescope or even binoculars show the nebula to be a few tens of light-years' wide complex of gas and dust, illuminated by several massive and hot stars at its core, the famous Trapezium stars . However, the heart of this nebula also conceals a secret from the casual observer. There are in fact about one thousand very young stars about one million years old within the so-called Trapezium Cluster , crowded into a space less than the distance between the Sun and its nearest neighbour stars. The cluster is very hard to observe in visible light, but is clearly seen in the above spectacular image of this area ( ESO PR 03a/01 ), obtained in December 1999 by Mark McCaughrean (Astrophysical Institute Potsdam, Germany) and his collaborators [1] with the infrared multi-mode ISAAC instrument on the ESO Very Large Telescope (VLT) at Paranal (Chile). Many details are seen in the new ISAAC image ESO PR Photo 03b/01 ESO PR Photo 03b/01 [Preview - JPEG: 400 x 589 pix - 62k] [Normal - JPEG: 800 x 1178 pix - 648k] [Hires - JPEG: 1957 x 2881 pix - 2.7M] ESO PR Photo 03c

  1. Edge detection

    NASA Astrophysics Data System (ADS)

    Hildreth, E. C.

    1985-09-01

    For both biological systems and machines, vision begins with a large and unwieldly array of measurements of the amount of light reflected from surfaces in the environment. The goal of vision is to recover physical properties of objects in the scene such as the location of object boundaries and the structure, color and texture of object surfaces, from the two-dimensional image that is projected onto the eye or camera. This goal is not achieved in a single step: vision proceeds in stages, with each stage producing increasingly more useful descriptions of the image and then the scene. The first clues about the physical properties of the scene are provided by the changes of intensity in the image. The importance of intensity changes and edges in early visual processing has led to extensive research on their detection, description and use, both in computer and biological vision systems. This article reviews some of the theory that underlies the detection of edges, and the methods used to carry out this analysis.

  2. The Pill Really Can Be Mightier Than the Sword: A Response to Recent Commentaries.

    PubMed

    Potts, Malcolm; Graves, Alisha

    2016-03-01

    We appreciate the four commentaries that add new material and fresh perspectives to our article "The pill is mightier than the sword." In emphasizing the role of voluntary family planning and girls' education as achievable strategies with a potential to make the world a more peaceable place, we did not mean to oversimplify or disregard the intrinsic complexity of human conflict. On the whole, the commentators support and add to our thesis, although we question Pillai and Ya-Chien Wang's suggestion that we may have overstated the unique human predisposition to kill our own species. We present additional data on male team aggression. PMID:26927598

  3. Achromatic imaging by means of the refractive light sword optical element

    NASA Astrophysics Data System (ADS)

    Ares Garcia, J.; Bará, S.; Gomez Garcia, M.; Jaroszewicz, Z.; Kolodziejczyk, A.; Petelczyc, K.

    2008-12-01

    The paper presents experiments with a refractive light sword optical element (LSOE). A refractive version of the LSOE was prepared in photoresist by gray scale photolithography. Then we examined chromatic aberrations of the produced element and compared them with those corresponding to a lens. For this purpose we performed two experiments, the first one where white light illumination was used and the latter one by the help of monochromatic illumination with three different wavelengths. The obtained results lead to the conclusion that the refractive LSOE does not exhibit significant chromatic aberrations and can be successfully used for imaging with extended depth of focus in polychromatic illumination.

  4. The Pill Really Can Be Mightier Than the Sword: A Response to Recent Commentaries

    PubMed Central

    Potts, Malcolm; Graves, Alisha

    2016-01-01

    We appreciate the four commentaries that add new material and fresh perspectives to our article "The pill is mightier than the sword." In emphasizing the role of voluntary family planning and girls’ education as achievable strategies with a potential to make the world a more peaceable place, we did not mean to oversimplify or disregard the intrinsic complexity of human conflict. On the whole, the commentators support and add to our thesis, although we question Pillai and Ya-Chien Wang’s suggestion that we may have overstated the unique human predisposition to kill our own species. We present additional data on male team aggression. PMID:26927598

  5. Use of a narrow-gap prewell for the optical study of charge buildup and the Fermi-energy edge singularity in a double-barrier resonant-tunneling structure

    NASA Astrophysics Data System (ADS)

    Fisher, T. A.; Buckle, P. D.; Simmonds, P. E.; Teissier, R. J.; Skolnick, M. S.; White, C. R. H.; Whittaker, D. M.; Eaves, L.; Usher, B.; Kemeny, P. C.; Grey, R.; Hill, G.; Pate, M. A.

    1994-12-01

    A strained InyGa1-yAs layer is incorporated adjacent to the emitter barrier of an AlxGa1-xAs/GaAs/AlxGa1-xAs double-barrier resonant-tunneling structure (DBRTS), so that it forms a prewell for the electrons that accumulate prior to tunneling into the GaAs quantum well (QW). Observation of photoluminescence (PL) and photoluminescence excitation (PLE) from the prewell then enables a direct optical determination of the charging behavior in the emitter-accumulation region to be achieved. We show in addition that an optical probe of the prewell can, by consideration of the electrostatics, provide a reliable determination of the charge distribution in the whole DBRTS at the peak of the tunneling resonance. These results are shown to be in agreement with separate determinations of the charge in the GaAs QW by direct PL measurements, and of the charge in the emitter-accumulation layer from magnetotransport studies. The electron density in the prewell can be varied continuously over a wide range, from 0 to 9×1011 cm-2. The second subband is populated at high applied bias, with the density varying from 0 to 1×1011 cm-2. This structure is then very well suited to the study of the many-body nature of the excitonic enhancement near the absorption threshold, over a much wider range of electron densities than previously studied on an individual sample. Utilizing temperature-dependent PLE measurements, we have monitored the variation from an atomic exciton in n=1, to a Fermi-energy edge singularity (FEES) in n=1, through to a FEES in n=2, in the same sample.

  6. Hospital security's two-edged sword: over-reliance on automation, under-reliance on experienced personnel.

    PubMed

    Kelty, J

    The article explores the current trend in the healthcare industry of cutting not only personnel--security directors, managers, and security officers--but also training programs in the name of budget cuts. What are the dangers to patient protection? What changes can be made to operate more effectively in this economic climate? Why does over-reliance on automation create problems of its own? PMID:11382995

  7. Electronic and chemical state of aluminum from the single- (K) and double-electron excitation (KLII&III, KLI) x-ray absorption near-edge spectra of α-alumina, sodium aluminate, aqueous Al³⁺•(H₂O)₆, and aqueous Al(OH)₄⁻

    SciTech Connect

    Fulton, John L.; Govind, Niranjan; Huthwelker, Thomas; Bylaska, Eric J.; Vjunov, Aleksei; Pin, Sonia; Smurthwaite, Tricia D.

    2015-07-02

    We probe, at high energy resolution, the double electron excitation (KLII&II) x-ray absorption region that lies approximately 115 eV above the main Al K-edge (1566 eV) of α-alumina and sodium aluminate. The two solid standards, α-alumina (octahedral) and sodium aluminate (tetrahedral) are compared to aqueous species that have the same Al coordination symmetries, Al³⁺•6H₂O (octahedral) and Al(OH)₄⁻ (tetrahedral). For the octahedral species, the edge height of the KLII&III-edge is approximately 10% of the main K-edge however the edge height is much weaker (3% of K-edge height) for Al species with tetrahedral symmetry. For the α-alumina and aqueous Al³⁺•6H₂O the KLII&III spectra contain white line features and extended absorption fine structure (EXAFS) that mimics the K-edge spectra. The KLII&III-edge feature interferes with an important region of the extended-XAFS region of the spectra for the K-edge of the crystalline and aqueous standards. The K-edge spectra and K-edge positions are predicted using time-dependent density functional theory (TDDFT). The TDDFT calculations for the K-edge XANES spectra reproduce the observed transitions in the experimental spectra of the four Al species. The KLII&III and KLI onsets and their corresponding chemical shifts for the four standards are estimated using the delta self-consistent field (ΔSCF) method. Research by JLF, NG, EJB, AV, TDS was supported by U.S. Department of Energy’s (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. NG thanks Amity Andersen for help with the α-Al₂O₃ and tetrahedral sodium aluminate (NaAlO₂) clusters. All the calculations were performed using the Molecular Science Computing Capability at EMSL, a national scientific user facility sponsored by the U.S. Department of Energy’s Office of Biological and Environmental Research and located at

  8. SoftWare for Optimization of Radiation Detectors, SWORD Version 5.0.

    Energy Science and Technology Software Center (ESTSC)

    2013-10-23

    Version 05 SoftWare for Optimization of Radiation Detectors (SWORD) is a framework to allow easy simulation and evaluation of radiation detection systems. It is targeted at system designers, who want to evaluate and optimize system parameters without actually building hardware first, at sponsors who need to evaluate proposed or actual system designs independent of the supplier, without having access to actual hardware, and at operators who want to use simulation to evaluate observed phenomena. SWORDmore » is vertically integrated and modular. It allows users to define their own radiation detection instruments by building them from basic geometric “objects” and assigning those objects materials, detection, and/or radioactive emission properties. This process is accomplished by a CAD-like graphical user interface, in which objects may be defined, translated, rotated, grouped, arrayed, and/or nested to produce compound objects. In addition to providing the ability to build a detection system model from scratch, SWORD provides a library of “standard” detector design objects that can be used “as is” or modified by the user.« less

  9. Operation Dominic, Shot Sword Fish. Project Officers report - project 1. 2 surface phenomena

    SciTech Connect

    Young, G.A.; Phillips, D.E.

    1985-04-01

    Shot Sword Fish was an operational test of the ASROC antisubmarine weapon system. The general objectives of the project were (1) to record and measure the formation, growth, and dissipation of the visible surface phenomena, including slicks, spray domes, plumes, fallout, base surge, and foam patch resulting from the underwater detonation of an ASROC weapon; (2) to use the data obtained to estimate the actual depth of burst, position of burst, yield, and bubble period; (3) to determine the location of ships and platforms in the experimental array before, during, and after the test; (4) to provide surface-phenomena time-of-arrival data at platforms and ships in the array for use by other projects; and 85) to make the results available for improving the surface-phenomena scaling and prediction techniques employed f,r establishing delivery and lethal ranges for fleet nuclear weapons. In general, there was good agreement between the observed dimensions of the Sword Fish phenomena and the predictions.

  10. The Edge

    NASA Technical Reports Server (NTRS)

    2006-01-01

    6 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the edge (running diagonally from the lower left to the upper right) of a trough, which is part of a large pit crater complex in Noachis Terra. This type of trough forms through the collapse of surface materials into the subsurface, and often begins as a series of individual pit craters. Over time, continued collapse increases the diameter of individual pits until finally, adjacent pits merge to form a trough such as the one captured in this image. The deep shadowed area is caused in part by an overhang; layered rock beneath this overhang is less resistant to erosion, and thus has retreated tens of meters backward, beneath the overhang. A person could walk up inside this 'cave' formed by the overhanging layered material.

    Location near: 47.0oS, 355.7oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  11. Unified EDGE

    SciTech Connect

    2007-06-18

    UEDGE is an interactive suite of physics packages using the Python or BASIS scripting systems. The plasma is described by time-dependent 2D plasma fluid equations that include equations for density, velocity, ion temperature, electron temperature, electrostatic potential, and gas density in the edge region of a magnetic fusion energy confinement device. Slab, cylindrical, and toroidal geometries are allowed, and closed and open magnetic field-line regions are included. Classical transport is assumed along magnetic field lines, and anomalous transport is assumed across field lines. Multi-charge state impurities can be included with the corresponding line-radiation energy loss. Although UEDGE is written in Fortran, for efficient execution and analysis of results, it utilizes either Python or BASIS scripting shells. Python is easily available for many platforms (http://www.Python.org/). The features and availability of BASIS are described in “Basis Manual Set” by P.F. Dubois, Z.C. Motteler, et al., Lawrence Livermore National Laboratory report UCRL-MA-1 18541, June, 2002 and http://basis.llnl.gov. BASIS has been reviewed and released by LLNL for unlimited distribution. The Python version utilizes PYBASIS scripts developed by D.P. Grote, LLNL. The Python version also uses MPPL code and MAC Perl script, available from the public-domain BASIS source above. The Forthon version of UEDGE uses the same source files, but utilizes Forthon to produce a Python-compatible source. Forthon has been developed by D.P. Grote at LBL (see http://hifweb.lbl.gov/Forthon/ and Grote et al. in the references below), and it is freely available. The graphics can be performed by any package importable to Python, such as PYGIST.

  12. Unified EDGE

    Energy Science and Technology Software Center (ESTSC)

    2007-06-18

    UEDGE is an interactive suite of physics packages using the Python or BASIS scripting systems. The plasma is described by time-dependent 2D plasma fluid equations that include equations for density, velocity, ion temperature, electron temperature, electrostatic potential, and gas density in the edge region of a magnetic fusion energy confinement device. Slab, cylindrical, and toroidal geometries are allowed, and closed and open magnetic field-line regions are included. Classical transport is assumed along magnetic field lines,more » and anomalous transport is assumed across field lines. Multi-charge state impurities can be included with the corresponding line-radiation energy loss. Although UEDGE is written in Fortran, for efficient execution and analysis of results, it utilizes either Python or BASIS scripting shells. Python is easily available for many platforms (http://www.Python.org/). The features and availability of BASIS are described in “Basis Manual Set” by P.F. Dubois, Z.C. Motteler, et al., Lawrence Livermore National Laboratory report UCRL-MA-1 18541, June, 2002 and http://basis.llnl.gov. BASIS has been reviewed and released by LLNL for unlimited distribution. The Python version utilizes PYBASIS scripts developed by D.P. Grote, LLNL. The Python version also uses MPPL code and MAC Perl script, available from the public-domain BASIS source above. The Forthon version of UEDGE uses the same source files, but utilizes Forthon to produce a Python-compatible source. Forthon has been developed by D.P. Grote at LBL (see http://hifweb.lbl.gov/Forthon/ and Grote et al. in the references below), and it is freely available. The graphics can be performed by any package importable to Python, such as PYGIST.« less

  13. Edge detection based on gradient ghost imaging.

    PubMed

    Liu, Xue-Feng; Yao, Xu-Ri; Lan, Ruo-Ming; Wang, Chao; Zhai, Guang-Jie

    2015-12-28

    We present an experimental demonstration of edge detection based on ghost imaging (GI) in the gradient domain. Through modification of a random light field, gradient GI (GGI) can directly give the edge of an object without needing the original image. As edges of real objects are usually sparser than the original objects, the signal-to-noise ratio (SNR) of the edge detection result will be dramatically enhanced, especially for large-area, high-transmittance objects. In this study, we experimentally perform one- and two-dimensional edge detection with a double-slit based on GI and GGI. The use of GGI improves the SNR significantly in both cases. Gray-scale objects are also studied by the use of simulation. The special advantages of GI will make the edge detection based on GGI be valuable in real applications. PMID:26832041

  14. Quality Coaching Counts

    ERIC Educational Resources Information Center

    Gould, Daniel

    2016-01-01

    Scholastic sport is a double-edged sword that can have positive or negative effects. Whether those effects are positive or negative depends on those who wield that sword--chiefly, the school's sports coach. While it is clear that coaches make a difference in ensuring that educational athletics lead to beneficial outcomes for student-athletes, a…

  15. Transcriptomics: a sword to cut the Gordian knot of traditional Chinese medicine.

    PubMed

    Liu, Yufeng; Ai, Ni; Liao, Jie; Fan, Xiaohui

    2015-01-01

    The systemic effects of traditional Chinese medicine (TCM) seem to be a Gordian knot, impossible to untie for decades. With the advent of transcriptomics, a useful sword is provided to cut the knot and shed some light on complex bioprocesses and intrinsic connections among them. Here, we revisit studies on TCM ZHENGs using this approach, highlight its applications on elucidating the potential scientific basis of ZHENG and investigating mechanisms of action for the TCM formula, and demonstrating its unique role in novel TCM drug design and discovery through active ingredient detection from TCM and compatibility theory study of TCM. The limitations and future perspectives of transcriptomics approaches to TCM study are also discussed. PMID:26501686

  16. Contrast transfer characteristics of the light sword optical element designed for presbyopia compensation

    NASA Astrophysics Data System (ADS)

    Petelczyc, K.; Bará, S.; Ciro López, A.; Jaroszewicz, Z.; Kakarenko, K.; Kolodziejczyk, A.; Sypek, M.

    2011-11-01

    The paper discusses the abilities of the light sword optical element (LSOE) for presbyopia compensation. The imaging properties are analyzed by means of the modulation transfer functions and output images of the star resolution test. All numerical calculations are performed assuming an optical set-up simulating the presbyopic human eye and based on the Gullstrand model. In order to have a meaningful comparison we expand our study and present adequate analysis for other elements potentially useful in ophthalmology as reading glasses, bifocal lenses and axicons. According to the obtained results the LSOE can successfully realize vision with an extended depth of field. The element makes possible the compensation of an assumed defocus up to 4 dioptres. The output images formed by the LSOE are well recognizable and have acceptable qualities for near as well as far object distances.

  17. Energetic ion excited long-lasting ``sword'' modes in tokamak plasmas with low magnetic shear

    NASA Astrophysics Data System (ADS)

    Wang, Xiaogang; Zhang, Ruibin; Deng, Wei; Liu, Yi

    2013-10-01

    An m/ n = 1 mode driven by trapped fast ions with a sword-shape envelope of long-lasting (for hundreds of milliseconds) magnetic perturbation signals, other than conventional fishbones, is studied in this paper. The mode is usually observed in low shear plasmas. Frequency and growth rate of the mode and its harmonics are calculated and in good agreements with observations. The radial mode structure is also obtained and compared with that of fishbones. It is found that due to fast ion driven the mode differs from magnetohydrodynamic long lived modes (LLMs) observed in MAST and NSTX. On the other hand, due to the feature of weak magnetic shear, the mode is also significantly different from fishbones. The nonlinear evolution of the mode and its comparison with fishbones are further investigated to analyze the effect of the mode on energetic particle transport and confinement.

  18. Application of the light sword optical element in a case of presbyopia

    NASA Astrophysics Data System (ADS)

    Jaroszewicz, Zbigniew; Kolodziejczyk, Andrzej; Makowski, Michał; Mikuła, Grzegorz; Pawlak, Iwona; Petelczyc, Krzysztof; Suszek, Jarosław; Sypek, Maciej

    2006-04-01

    The paper presents abilities of the Light Sword Optical Element (LSOE) for imaging with extended depth of focus. The LSOE belongs to the class of optical elements focusing incident light into a segment of the optical axis. The elements of this kind can be used as correctors of some defects of human eye accommodation, especially in a case of presbyopia. The paper illustrates imaging properties of the LSOE. In particular, the point spread functions of the LSOE are analysed numerically. Imaging properties of the LSOE are compared with properties of optical elements being potentially useful for presbyopia correction as axicons, bifocal lens and trifocal lens. The experimental results illustrating usefulness of the LSOE in a case of presbyopia are given.

  19. Hippocratic ideal, Faustian bargain and Damocles' sword: erosion of patient autonomy in obstetrics.

    PubMed

    Rybak, E A

    2009-11-01

    Respect for patient autonomy remains a foundational principle guiding the ethical practice of medicine-a mission first articulated by Hippocrates. Damocles, another figure from ancient Greece, provides a useful parable for describing performance under distress: Damocles loses his desire for opulence and power when he notices a sword dangling precariously above his head. Contemporary obstetricians deciding whether to forestall or impose major abdominal surgery on parturients entrusted to their care struggle valiantly in the chasm dividing Hippocratic idealism from the economic realism driven by the medicolegal sword of Damocles. Given the inherent risk of unforeseeable and unsalvageable fetal catastrophe during labor and vaginal delivery, and the often unsubstantiated, yet automatic, allegation of negligence that follows a labor-associated adversity, obstetricians-and their liability insurance carriers-have recalibrated obstetric practice in alignment with the increasingly risk-averse preferences of most patients. Indeed, less intrapartum risk for patients and less corresponding medicolegal exposure for obstetricians help explain the rising cesarean delivery rate and, more importantly, the steady disappearance of higher-risk interventions such as vaginal birth after cesarean (VBAC). Is this increasing reluctance to offer VBAC supervision ethically defensible? This paper argues that it is. Fiduciary professionalism mandates physician self-sacrifice, not self-destruction; a VBAC gone awry without negligence or substandard care may, nevertheless, render future affordable liability coverage unattainable. Yet, the unavailability of VBAC infringes on the autonomy of women who want to assume the intrapartum risks of a VBAC in lieu of a repeat cesarean delivery. The proposed solution is the regionalization of VBAC care provision in designated medical centers and/or the implementation of binding arbitration in an ethical trade-off to enhance patient autonomy regarding the

  20. Sword field, offshore California: challenges in making this giant oil field commercial

    SciTech Connect

    Ballard, J.H.

    1988-03-01

    The major obstacles and challenges involved in exploration and development of a giant deep-water low-gravity oil field are exemplified in the undeveloped Sword field of offshore southern California. In 1979, Conoco Exploration identified a northeast-southwest-trending basement high in 800-2000 ft deep federal waters 12 mi southwest of Pt. Conception at the western end of the Santa Barbara Channel. The intended reservoir was fractured Miocene Monterey chert, siliceous shales or siltstones, and dolomites that are draped over the axially faulted anticlinal structure. Drilling of the initial well in OCS P-0322 in 1982 resulted in discovering the giant Sword field. A confirmation well drilled in OCS P-0320 indicates in-place reserves of well over 1 billion bbl. Although the discovered potential is significant, the low gravity (8.5/sup 0/-10.5/sup 0/ API) of the oils discovered to date, along with water depths in excess of 1500 ft, currently pose economic challenges to successful field development. Conoco and its partners are addressing the current economic barriers on several fronts. A three-dimensional seismic survey has been conducted to delineate reservoir geometry and to define probable variations in pay thickness and fracturing. A market feasibility study will be undertaken to assess the demand for low gravity crude from offshore California. Finally, Conoco has developed proprietary technology called OCHOS (Offshore California Heavy Oil System), which uses an innovative oil and/or water emulsion technique to allow for more economic recovery of high-velocity or low-gravity crudes.

  1. James Sowerby: meteorites and his meteoritic sword made for the Emperor of Russia, Alexander I, in 1814

    PubMed Central

    Henderson, Paul

    2013-01-01

    James Sowerby included meteorites in his publications of British and exotic natural history and so raised interest in their nature and origins at a time of much debate and involving the President of the Royal Society, Sir Joseph Banks. The celebrations over the defeat of France in 1814 prompted Sowerby to make a sword from the Cape of Good Hope iron meteorite to present to the Russian Emperor, Alexander I, at the time of his state visit to London in June 1814 and in recognition of his achievements in bringing peace to Europe. The story of its attempted presentation, its final reception and the following response, including publications, all helped to increase interest in meteorites and their properties. The rediscovery of the sword after a lengthy disappearance probably brings an unusual saga to a fitting close.

  2. Edge States in Transitional Pipe Flow

    NASA Astrophysics Data System (ADS)

    Schneider, Tobias M.; Eckhardt, Bruno

    2006-11-01

    We study the boundary of the laminar region near the onset of turbulence. Approaching the boundary from the laminar side, the lifetime of perturbations increases, diverges when the boundary is reached, and varies chaotically for larger amplitudes. In the chaotic region, lifetimes vary sensitively with amplitude, consistent with the strange saddle picture of the turbulence proposed earlier. The trajectory on the edge between the laminar and chaotic regions is asymptotic to a single well defined state, essentially independent of the type of perturbation. The edge then becomes the stable manifold of this structure. In the case of a model shear flow, the edge states are simple or period doubled or chaotic trajectories. In the case of pipe flow the edge state seems to remain close to a state with simple vortical structure. Edge of Chaos in a Parallel Shear Flow, Joseph D. Skufca, James A. Yorke, and Bruno Eckhardt, Phys. Rev. Lett. 96, 174101 (2006)

  3. The edges of graphene.

    PubMed

    Zhang, Xiuyun; Xin, John; Ding, Feng

    2013-04-01

    The edge of two dimensional (2D) graphene, as the surface of a three dimensional (3D) crystal, plays a crucial role in the determination of its physical, electronic and chemical properties and thus has been extensively studied recently. In this review, we summarize the recent advances in the study of graphene edges, including edge formation energy, edge reconstruction, method of graphene edge synthesis and the recent progress on metal-passivated graphene edges and the role of edges in graphene CVD growth. We expect this review to provide a guideline for readers to gain a clear picture of graphene edges from several aspects, especially the catalyst-passivated graphene edges and their role in graphene CVD growth. PMID:23420074

  4. The edges of graphene

    NASA Astrophysics Data System (ADS)

    Zhang, Xiuyun; Xin, John; Ding, Feng

    2013-03-01

    The edge of two dimensional (2D) graphene, as the surface of a three dimensional (3D) crystal, plays a crucial role in the determination of its physical, electronic and chemical properties and thus has been extensively studied recently. In this review, we summarize the recent advances in the study of graphene edges, including edge formation energy, edge reconstruction, method of graphene edge synthesis and the recent progress on metal-passivated graphene edges and the role of edges in graphene CVD growth. We expect this review to provide a guideline for readers to gain a clear picture of graphene edges from several aspects, especially the catalyst-passivated graphene edges and their role in graphene CVD growth.

  5. More a plowshare than a sword: the legacy of US Cold War agricultural diplomacy.

    PubMed

    McGlade, Jacqueline

    2009-01-01

    Recently, agriculture has assumed an elevated role in world diplomacy due to pressing issues like international poverty relief, changing environmental conditions, farm trade imbalances, rising food prices, and the diversion of crops into bio-fuel production. Consequently, agricultural interests and production have become increasingly entwined with the politics of national protectionism and identity, domestic security, and the preservation of trading advantage in developed and developing countries alike. This study examines the current impasse in world agricultural negotiations as an outgrowth of US foreign aid and trade policymaking as it evolved during the Cold War. In particular, it chronicles the historic shift in US foreign policy away from "give-away" food aid and surplus sales and toward the championing of global agricultural redevelopment under such programs as the Marshall Plan and PL 480, the Food for Peace program. As more a plowshare than a sword, the American Cold War push for worldwide agricultural modernization led many countries to experience new levels of food self-efficiency and export capabilities. Along with production parity, however, has come escalating levels of trade competition and national protectionism, which challenges again the achievement of world agricultural stability and prosperity. PMID:19618529

  6. SWORD '99: surveillance of work-related and occupational respiratory disease in the UK.

    PubMed

    Meyer, J D; Holt, D L; Chen, Y; Cherry, N M; McDonald, J C

    2001-05-01

    Systematic reports from chest and occupational physicians under the SWORD and OPRA (Occupational Physicians Reporting Activity) surveillance schemes continue to provide a picture of the incidence of occupational respiratory disease in the UK. An estimated total of 4393 incident cases (comprising 4530 diagnoses) were reported during the 1999 calendar year, an increase of 1427 cases over the previous year. Benign pleural disease was the single most frequently reported condition (28% of all diagnoses reported). Occupational asthma cases (1168; 26%) remained high, as did mesothelioma (1032; 23%). Analysis of trends over the past 8 years shows an increase in mesothelioma cases, but little change in asthma. The annual incidence per 100,000 employed people, 1996-1999, for mesothelioma, lung cancer and pneumoconiosis was high amongst construction workers (28.7), miners and quarrymen (26.5), woodworkers (18.9) and gas, coal and chemical workers (15.2). Trends in mesothelioma incidence by birth cohort continue to show an increase in construction workers and a continuing decline in shipyard and insulation workers. The relative proportion of pneumoconiosis cases attributed to coal mining has fallen steadily in workers born since approximately 1920 and most cases are now in men who have been employed in quarrying and rock drilling. PMID:11385125

  7. Leather material found on a 6th B.C. Chinese bronze sword: A technical study

    NASA Astrophysics Data System (ADS)

    Luo, Wugan; Si, Yi; Wang, Hongmin; Qin, Ying; Huang, Fengchun; Wang, Changsui

    2011-09-01

    During July to November, 2006, an important archaeological excavation was conducted in Yun country, Hubei province, southern China. Chinese archaeologists found some remnant of leather materials, covered with red pigments, on a 6th century B.C. Chinese bronze sword. To understand the technology/ies that may have been utilized for manufacturing the leathers, a combined of Raman spectroscopy, FT-IR and XRF was thus applied to the remnant of leather materials. Raman analyses showed that red pigment on the leather was cinnabar (HgS). FT-IR and XRF analyses indicated that the content of some elements, such as Ca (existing as CaCO 3) and Fe (existing as Fe 2O 3), were much higher than those in the surrounding grave soil. The results inferred an application of lime depilation and retting, and the Fe-Al compound salt as tanning agent. And it was furthermore implicated that the Fe-Al salt tanning technique had been developed in the middle and late Spring and Autumn Period of China.

  8. Leather material found on a 6th B.C. Chinese bronze sword: a technical study.

    PubMed

    Luo, Wugan; Si, Yi; Wang, Hongmin; Qin, Ying; Huang, Fengchun; Wang, Changsui

    2011-09-01

    During July to November, 2006, an important archaeological excavation was conducted in Yun country, Hubei province, southern China. Chinese archaeologists found some remnant of leather materials, covered with red pigments, on a 6th century B.C. Chinese bronze sword. To understand the technology/ies that may have been utilized for manufacturing the leathers, a combined of Raman spectroscopy, FT-IR and XRF was thus applied to the remnant of leather materials. Raman analyses showed that red pigment on the leather was cinnabar (HgS). FT-IR and XRF analyses indicated that the content of some elements, such as Ca (existing as CaCO3) and Fe (existing as Fe2O3), were much higher than those in the surrounding grave soil. The results inferred an application of lime depilation and retting, and the Fe-Al compound salt as tanning agent. And it was furthermore implicated that the Fe-Al salt tanning technique had been developed in the middle and late Spring and Autumn Period of China. PMID:21703919

  9. VizieR Online Data Catalog: Stellar groups of Orion's Sword region (Vereshchangin+, 2010)

    NASA Astrophysics Data System (ADS)

    Vereshchangin, S. V.; Chupina, N. V.

    2010-09-01

    The region of Orion's Sword with coordinates RA=83.79°, DE=-5.20° and a size of 1.0°x2.5° is analyzed. We compiled a master catalog of stars observed in the optical, containing positions, proper motions, and UBV photometry for 1634 stars. Using the nearest-neighbor-distance technique, we subdivided the region into stellar groups with different numbers of members. The positions of five groups coincide with known clusters, and two groups coincide with aggregates of stars with Hα emission. We have identified groups with low membership that are moving away from the system. We also considered the kinematic structure of the groups using the AD-diagram method we developed earlier. Most of the stellar clusters and groups display similar kinematics, with the exception of the group OMC-2, which is moving toward its own apex. We also confirmed the existence of the kinematic star group 189 discovered earlier; its position is close to the cluster NGC 1977, and it is probably a component of its corona. (1 data file).

  10. Historical and Metallurgical Characterization of a "Falchion" Sword Manufactured in Caino (Brescia, Italy) in the Early 17th Century A.D.

    NASA Astrophysics Data System (ADS)

    Tonelli, G.; Faccoli, M.; Gotti, R.; Roberti, R.; Cornacchia, G.

    2016-04-01

    A historical and metallurgical characterization of a "falchion" sword manufactured in Caino (Brescia, northern Italy) and dating from the early 17th century was performed to understand the manufacture methods of a Renaissance sword. At first, a set of size measurements was carried out to look for the existence of constant and/or recurring macroscopic sizes, which would indicate a standardized production, or of any type of proportionality between different parts of a sword, which would prove an intentional design activity. Light optical microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, quantometer analyses, and Vickers microhardness tests were then employed to analyze the microstructure and obtain the mechanical properties. All the metallurgical work is supported by an accurate study on the chemical composition of both metal-matrix and nonmetallic inclusions, which allowed for rebuilding and evaluating the efficiency of the whole production process.