Systematic review of environmental risk factors for Obsessive-Compulsive Disorder: A proposed roadmap from association to causation.

PubMed

Brander, Gustaf; Pérez-Vigil, Ana; Larsson, Henrik; Mataix-Cols, David

2016-06-01

To synthesize the current knowledge on possible environmental risk factors for Obsessive-Compulsive Disorder (OCD). We conducted a systematic review following PRISMA guidelines. The Embase, PubMed and Scopus databases were searched up until October 6, 2015, employing relevant keywords and MeSH terms. 128 studies met inclusion criteria. Potential environmental risk factors for OCD have been identified in the broad areas of perinatal complications, reproductive cycle, and stressful life events. There is limited evidence regarding other potential risk factors, such as parental age, season of birth, socioeconomic status, parental rearing practices, infections, traumatic brain injury, substance use or vitamin deficiency. In general, studies were of limited methodological quality. At present, no environmental risk factors have convincingly been associated with OCD. We propose a roadmap for future studies, consisting of longitudinal, population-based research, employing quasi-experimental family and twin designs to identify risk factors that are not only associated with the disorder but also contribute to its causation either directly or moderating the effect of genes. Copyright © 2016 Elsevier Ltd. All rights reserved.

How large B-factors can be in protein crystal structures.

PubMed

Carugo, Oliviero

2018-02-23

Protein crystal structures are potentially over-interpreted since they are routinely refined without any restraint on the upper limit of atomic B-factors. Consequently, some of their atoms, undetected in the electron density maps, are allowed to reach extremely large B-factors, even above 100 square Angstroms, and their final positions are purely speculative and not based on any experimental evidence. A strategy to define B-factors upper limits is described here, based on the analysis of protein crystal structures deposited in the Protein Data Bank prior 2008, when the tendency to allow B-factor to arbitrary inflate was limited. This B-factor upper limit (B_max) is determined by extrapolating the relationship between crystal structure average B-factor and percentage of crystal volume occupied by solvent (pcVol) to pcVol =100%, when, ab absurdo, the crystal contains only liquid solvent, the structure of which is, by definition, undetectable in electron density maps. It is thus possible to highlight structures with average B-factors larger than B_max, which should be considered with caution by the users of the information deposited in the Protein Data Bank, in order to avoid scientifically deleterious over-interpretations.

The Impact of Smoking on Airflow Limitation in Subjects with History of Asthma and Inactive Tuberculosis

PubMed Central

Kim, Hyun Jung; Baek, Seunghee; Kim, Hee Jin; Lee, Jae Seung; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Sei Won

2015-01-01

Background Although smoking is the most important and modifiable cause of chronic obstructive pulmonary disease (COPD), other risk factors including asthma and tuberculosis (TB) are also associated. It is common for COPD patients to have more than one of these risk factors. The aims of this study were to determine the prevalence of airflow limitation (FEV1/FVC<0.7) according to the risk factors and to investigate their impact and interaction in airflow limitation. Methods From the Korean National Health and Nutrition Examination Survey between 2008 and 2012, we analyzed participants over 40 years of age by spirometry, chest radiograph and questionnaire about asthma and smoking history. Results Of 12,631 participants, 1,548 (12.3%) had airflow limitation. The prevalence of airflow limitation in smokers (≥10 pack-year), asthmatics, and those with inactive TB was 23.9%, 32.1%, and 33.6%. The prevalence increased with the number of risk factors: 86.1% had airflow limitation if they had all three risk factors. Impacts of inactive TB and asthma on airflow limitation were equivalent to 47 and 69 pack-years of smoking, respectively. Airflow limitation resulted from lower levels of smoking in those with inactive TB and asthma. A potential interaction between smoking and inactive tuberculosis in the development of airflow limitation was identified (p = 0.054). Conclusions Asthma and inactive TB lesions increase susceptibility to smoking in the development of airflow limitation. People with these risk factors should be seen as a major target population for anti-smoking campaigns to prevent COPD. PMID:25915938

Energy efficiency : potential fuel savings generated by a national speed limit would be influenced by many other factors.

DOT National Transportation Integrated Search

2008-11-07

"Congress expressed interest in obtaining information on using a national speed limit to reduce fuel consumption. In response to the request, we reviewed existing literature and consulted knowledgeable stakeholders on the following: (1) What is the r...

Factors limiting sulfolane biodegradation in contaminated subarctic aquifer substrate.

PubMed

Kasanke, Christopher P; Leigh, Mary Beth

2017-01-01

Sulfolane, a water-soluble organosulfur compound, is used industrially worldwide and is associated with one of the largest contaminated groundwater plumes in the state of Alaska. Despite being widely used, little is understood about the degradation of sulfolane in the environment, especially in cold regions. We conducted aerobic and anaerobic microcosm studies to assess the biological and abiotic sulfolane degradation potential of contaminated subarctic aquifer groundwater and sediment from Interior Alaska. We also investigated the impacts of nutrient limitations and hydrocarbon co-contamination on sulfolane degradation. We found that sulfolane underwent biodegradation aerobically but not anaerobically under nitrate, sulfate, or iron-reducing conditions. No abiotic degradation activity was detectable under either oxic or anoxic conditions. Nutrient addition stimulated sulfolane biodegradation in sediment slurries at high sulfolane concentrations (100 mg L-1), but not at low sulfolane concentrations (500 μg L-1), and nutrient amendments were necessary to stimulate sulfolane biodegradation in incubations containing groundwater only. Hydrocarbon co-contamination retarded aerobic sulfolane biodegradation rates by ~30%. Our study is the first to investigate the sulfolane biodegradation potential of subarctic aquifer substrate and identifies several important factors limiting biodegradation rates. We concluded that oxygen is an important factor limiting natural attenuation of this sulfolane plume, and that nutrient amendments are unlikely to accelerate biodegradation within in the plume, although they may biostimulate degradation in ex situ groundwater treatment applications. Future work should be directed at elucidating the identity of indigenous sulfolane-degrading microorganisms and determining their distribution and potential activity in the environment.

Factors limiting sulfolane biodegradation in contaminated subarctic aquifer substrate

PubMed Central

2017-01-01

Sulfolane, a water-soluble organosulfur compound, is used industrially worldwide and is associated with one of the largest contaminated groundwater plumes in the state of Alaska. Despite being widely used, little is understood about the degradation of sulfolane in the environment, especially in cold regions. We conducted aerobic and anaerobic microcosm studies to assess the biological and abiotic sulfolane degradation potential of contaminated subarctic aquifer groundwater and sediment from Interior Alaska. We also investigated the impacts of nutrient limitations and hydrocarbon co-contamination on sulfolane degradation. We found that sulfolane underwent biodegradation aerobically but not anaerobically under nitrate, sulfate, or iron-reducing conditions. No abiotic degradation activity was detectable under either oxic or anoxic conditions. Nutrient addition stimulated sulfolane biodegradation in sediment slurries at high sulfolane concentrations (100 mg L-1), but not at low sulfolane concentrations (500 μg L-1), and nutrient amendments were necessary to stimulate sulfolane biodegradation in incubations containing groundwater only. Hydrocarbon co-contamination retarded aerobic sulfolane biodegradation rates by ~30%. Our study is the first to investigate the sulfolane biodegradation potential of subarctic aquifer substrate and identifies several important factors limiting biodegradation rates. We concluded that oxygen is an important factor limiting natural attenuation of this sulfolane plume, and that nutrient amendments are unlikely to accelerate biodegradation within in the plume, although they may biostimulate degradation in ex situ groundwater treatment applications. Future work should be directed at elucidating the identity of indigenous sulfolane-degrading microorganisms and determining their distribution and potential activity in the environment. PMID:28727811

The WRKY transcription factor family and senescence in switchgrass

USDA-ARS?s Scientific Manuscript database

Background: Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. Methods: All potential WRKY genes present in the version 1.0 of the...

Genetic Technology and Agricultural Development

ERIC Educational Resources Information Center

Staub, William J.; Blase, Melvin G.

1971-01-01

Examines the nature, application, limits and potential of applied genetics in plant breeding as a factor in South Asian agricultural development. Concludes other factors were also present in recent agricultural growth, and indicates some economic implications of continued growth, including problems of employment of displaced rural workers. (AL)

Optimizing the performance and structure of the D0 Collie confidence limit evaluator

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

Fishchler, Mark; /Fermilab

2010-07-01

D0 Collie is a program used to perform limit calculations based on ensembles of pseudo-experiments ('PEs'). Since the application of this program to the crucial Higgs mass limit is quite CPU intensive, it has been deemed important to carefully review this program, with an eye toward identifying and implementing potential performance improvements. At the same time, we identify any coding errors or opportunities for potential structural (or algorithm) improvement discovered in the course of gaining sufficient understanding of the workings of Collie to sensibly explore for optimizations. Based on a careful analysis of the program, a series of code changesmore » with potential for improving performance has been identified. The implementation and evaluation of the most important parts of this series has been done, with gratifying speedup results. The bottom line: We have identified and implemented changes leading to a factor of 2.19 speedup in the example program provided, and expected to translate to a factor of roughly 4 speedup in typical realistic usage.« less

Generalizability of dietary patterns of the inverse association between alcohol consumption and type 2 diabetes risk

USDA-ARS?s Scientific Manuscript database

Epidemiology of dietary components and disease risk limits interpretability due to potential residual confounding by correlated dietary components. Dietary pattern analyses by factor analysis or partial least squares may overcome this limitation. To examine confounding by dietary pattern as well as ...

Confounding by dietary pattern of the inverse association between alcohol consumption and type 2 diabetes risk

USDA-ARS?s Scientific Manuscript database

Epidemiology of dietary components and disease risk limits interpretability due to potential residual confounding by correlated dietary components. Dietary pattern analyses by factor analysis or partial least squares may overcome the limitation. To examine confounding by dietary pattern as well as ...

Confounding by dietary patterns of the inverse association between alcohol consumption and type 2 diabetes risk

USDA-ARS?s Scientific Manuscript database

Epidemiology of dietary components and disease risk limits interpretability due to potential residual confounding by correlated dietary components. Dietary pattern analyses by factor analysis or partial least squares may overcome this limitation. To examine confounding by dietary pattern as well as ...

Potential impacts of ambient ozone on wheat rust diseases and the role of plant ozone sensitivity

USDA-ARS?s Scientific Manuscript database

The resurgence of rust diseases and the continued rise in tropospheric ozone (O3) levels have the potential to limit global wheat production. We conducted a series of experiments to understand the potential interactions between these two stress factors. Both stem rust and leaf rust were increased o...

[Assessment of the potential for urban facade greening in Xinjiekou District, Nanjing, China.

PubMed

Shi, Bao Gang; Yin, Hai Wei; Kong, Fan Hua

2018-05-01

Green facade is an important strategy to improve the urban eco-environment and reduce the negative effects of human activities in central districts of cities which are land-scarce and lack green spaces. We first summarized the limiting factors for the construction of green facades locally and internationally. Then, we used the Xinjiekou District of Nanjing City in China as a case study area, and selected the wind environment, solar environment, and physical build environment that might impact the potential development of green facades as key factors to quantitatively analyze singlely by geographic information systems (GIS) and computational fluid dynamics (CFD). Finally, the potential area to develop green facades was assessed through a multi-factor overlay analysis. The results showed that 17726 m 2 of wall spaces in the Xinjiekou District had a high potential for facade greening, accounting for 30.8% of all exterior wall space under a height of 12 m and 17.3% of the entire study area. Sunlight was a key limiting factor in determining whether a green facade should be developed. Irrigation was identified as another important factor that might strongly affect the growth of vertical vegetation in urban environment. The spatial distribution of walls suitable for facade greening was uneven, with an "inner-high and south-high" spatial pattern. Our results would help to guide the design and development of green facades in Xinjiekou, and also provide a reference for planning and utilizing green wall space projects in other built and dense urban areas.

Liposome production by microfluidics: potential and limiting factors

PubMed Central

Carugo, Dario; Bottaro, Elisabetta; Owen, Joshua; Stride, Eleanor; Nastruzzi, Claudio

2016-01-01

This paper provides an analysis of microfluidic techniques for the production of nanoscale lipid-based vesicular systems. In particular we focus on the key issues associated with the microfluidic production of liposomes. These include, but are not limited to, the role of lipid formulation, lipid concentration, residual amount of solvent, production method (including microchannel architecture), and drug loading in determining liposome characteristics. Furthermore, we propose microfluidic architectures for the mass production of liposomes with a view to potential industrial translation of this technology. PMID:27194474

Liposome production by microfluidics: potential and limiting factors.

PubMed

Carugo, Dario; Bottaro, Elisabetta; Owen, Joshua; Stride, Eleanor; Nastruzzi, Claudio

2016-05-19

This paper provides an analysis of microfluidic techniques for the production of nanoscale lipid-based vesicular systems. In particular we focus on the key issues associated with the microfluidic production of liposomes. These include, but are not limited to, the role of lipid formulation, lipid concentration, residual amount of solvent, production method (including microchannel architecture), and drug loading in determining liposome characteristics. Furthermore, we propose microfluidic architectures for the mass production of liposomes with a view to potential industrial translation of this technology.

Evaluation of the impact of frost resistances on potential altitudinal limit of trees.

PubMed

Charrier, Guillaume; Cochard, Hervé; Améglio, Thierry

2013-09-01

Winter physiology of woody plants is a key issue in temperate biomes. Here, we investigated different frost resistance mechanisms on 1-year-old branches of 11 European tree species from November until budburst: (i) frost hardiness of living cells (by electrolyte leakage method), (ii) winter embolism sensitivity (by percentage loss of conductivity: PLC) and (iii) phenological variation of budburst (by thermal time to budburst). These ecophysiological traits were analyzed according to the potential altitudinal limit, which is highly related to frost exposure. Seasonal frost hardiness and PLC changes are relatively different across species. Maximal PLC observed in winter (PLCMax) was the factor most closely related to potential altitudinal limit. Moreover, PLCMax was related to the mean hydraulic diameter of vessels (indicating embolism sensitivity) and to osmotic compounds (indicating ability of living cells to refill xylem conducting elements). Winter embolism formation seems to be counterbalanced by active refilling from living cells. These results enabled us to model potential altitudinal limit according to three of the physiological/anatomical parameters studied. Monitoring different frost resistance strategies brings new insights to our understanding of the altitudinal limits of trees.

Commentary Considerations for Recommending Extended Use and Limited Reuse of Filtering Facepiece Respirators in Health Care Settings

PubMed Central

Fisher, Edward M.; Shaffer, Ronald E.

2015-01-01

Public health organizations, such as the Centers for Disease Control and Prevention (CDC), are increasingly recommending the use of N95 filtering facepiece respirators (FFRs) in health care settings. For infection control purposes, the usual practice is to discard FFRs after close contact with a patient (“single use”). However, in some situations, such as during contact with tuberculosis patients, limited FFR reuse (i.e., repeated donning and doffing of the same FFR by the same person) is practiced. A related practice, extended use, involves wearing the same FFR for multiple patient encounters without doffing. Extended use and limited FFR reuse have been recommended during infectious disease outbreaks and pandemics to conserve FFR supplies. This commentary examines CDC recommendations related to FFR extended use and limited reuse and analyzes available data from the literature to provide a relative estimate of the risks of these practices compared to single use. Analysis of the available data and the use of disease transmission models indicate that decisions regarding whether FFR extended use or reuse should be recommended should continue to be pathogen- and event-specific. Factors to be included in developing the recommendations are the potential for the pathogen to spread via contact transmission, the potential that the event could result in or is currently causing a FFR shortage, the protection provided by FFR use, human factors, potential for self-inoculation, the potential for secondary exposures, and government policies and regulations. While recent findings largely support the previous recommendations for extended use and limited reuse in certain situations, some new cautions and limitations should be considered before issuing recommendations in the future. In general, extended use of FFRs is preferred over limited FFR reuse. Limited FFR reuse would allow the user a brief respite from extended wear times, but increases the risk of self-inoculation and preliminary data from one study suggest that some FFR models may begin to lose effectiveness after multiple donnings. PMID:24628658

Environmental determinants of polycystic ovary syndrome.

PubMed

Merkin, Sharon Stein; Phy, Jennifer L; Sites, Cynthia K; Yang, Dongzi

2016-07-01

In this review, we summarize existing research on a variety of environmental factors potentially involved in the etiology, prevalence, and modulation of polycystic ovary syndrome (PCOS), and we suggest avenues for future research. The main environmental factors we consider include environmental toxins, diet and nutrition, socioeconomic status, and geography. There is some evidence that environmental toxins play a role in disrupting reproductive health, but there is limited research as to how these toxins may affect the development of PCOS. Although research has also shown that PCOS symptoms are reduced with certain dietary supplements and with weight loss among obese women, additional research is needed to compare various approaches to weight loss, as well as nutritional factors that may play a role in preventing or mitigating the development of PCOS. Limited studies indicate some association of low socioeconomic status with certain PCOS phenotypes, and future research should consider socioeconomic conditions during childhood or adolescence that may be more relevant to the developmental onset of PCOS. Finally, the limited scope of comparable international studies on PCOS needs to be addressed, because global patterns of PCOS are potentially valuable indicators of cultural, environmental, and genetic factors that may contribute to excess risk in certain regions of the world. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis.

PubMed

Cheng, Feon W; Gao, Xiang; Bao, Le; Mitchell, Diane C; Wood, Craig; Sliwinski, Martin J; Smiciklas-Wright, Helen; Still, Christopher D; Rolston, David D K; Jensen, Gordon L

2017-07-01

To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. The conditional inference tree analysis, a data mining approach, was used to construct a risk stratification algorithm for developing functional limitation based on BMI and other potential risk factors for disability in 1,951 older adults without functional limitations at baseline (baseline age 73.1 ± 4.2 y). We also analyzed the data with multivariate stepwise logistic regression and compared the two approaches (e.g., cross-validation). Over a mean of 9.2 ± 1.7 years of follow-up, 221 individuals developed functional limitation. Higher BMI, age, and comorbidity were consistently identified as significant risk factors for functional decline using both methods. Based on these factors, individuals were stratified into four risk groups via the conditional inference tree analysis. Compared to the low-risk group, all other groups had a significantly higher risk of developing functional limitation. The odds ratio comparing two extreme categories was 9.09 (95% confidence interval: 4.68, 17.6). Higher BMI, age, and comorbid disease were consistently identified as significant risk factors for functional decline among older individuals across all approaches and analyses. © 2017 The Obesity Society.

Evidence Does Not Support Clinical Screening of Literacy

PubMed Central

Wolf, Michael S.

2007-01-01

Limited health literacy is a significant risk factor for adverse health outcomes. Despite controversy, many health care professionals have called for routine clinical screening of patients’ literacy skills. Whereas brief literacy screening tools exist that with further evaluation could potentially be used to detect limited literacy in clinical settings, no screening program for limited literacy has been shown to be effective. Yet there is a noted potential for harm, in the form of shame and alienation, which might be induced through clinical screening. There is fair evidence to suggest that possible harm outweighs any current benefits; therefore, clinical screening for literacy should not be recommended at this time. PMID:17992564

Addition of multiple limiting resources reduces grassland diversity.

PubMed

Harpole, W Stanley; Sullivan, Lauren L; Lind, Eric M; Firn, Jennifer; Adler, Peter B; Borer, Elizabeth T; Chase, Jonathan; Fay, Philip A; Hautier, Yann; Hillebrand, Helmut; MacDougall, Andrew S; Seabloom, Eric W; Williams, Ryan; Bakker, Jonathan D; Cadotte, Marc W; Chaneton, Enrique J; Chu, Chengjin; Cleland, Elsa E; D'Antonio, Carla; Davies, Kendi F; Gruner, Daniel S; Hagenah, Nicole; Kirkman, Kevin; Knops, Johannes M H; La Pierre, Kimberly J; McCulley, Rebecca L; Moore, Joslin L; Morgan, John W; Prober, Suzanne M; Risch, Anita C; Schuetz, Martin; Stevens, Carly J; Wragg, Peter D

2016-09-01

Niche dimensionality provides a general theoretical explanation for biodiversity-more niches, defined by more limiting factors, allow for more ways that species can coexist. Because plant species compete for the same set of limiting resources, theory predicts that addition of a limiting resource eliminates potential trade-offs, reducing the number of species that can coexist. Multiple nutrient limitation of plant production is common and therefore fertilization may reduce diversity by reducing the number or dimensionality of belowground limiting factors. At the same time, nutrient addition, by increasing biomass, should ultimately shift competition from belowground nutrients towards a one-dimensional competitive trade-off for light. Here we show that plant species diversity decreased when a greater number of limiting nutrients were added across 45 grassland sites from a multi-continent experimental network. The number of added nutrients predicted diversity loss, even after controlling for effects of plant biomass, and even where biomass production was not nutrient-limited. We found that elevated resource supply reduced niche dimensionality and diversity and increased both productivity and compositional turnover. Our results point to the importance of understanding dimensionality in ecological systems that are undergoing diversity loss in response to multiple global change factors.

Fast sparse recovery and coherence factor weighting in optoacoustic tomography

NASA Astrophysics Data System (ADS)

He, Hailong; Prakash, Jaya; Buehler, Andreas; Ntziachristos, Vasilis

2017-03-01

Sparse recovery algorithms have shown great potential to reconstruct images with limited view datasets in optoacoustic tomography, with a disadvantage of being computational expensive. In this paper, we improve the fast convergent Split Augmented Lagrangian Shrinkage Algorithm (SALSA) method based on least square QR (LSQR) formulation for performing accelerated reconstructions. Further, coherence factor is calculated to weight the final reconstruction result, which can further reduce artifacts arising in limited-view scenarios and acoustically heterogeneous mediums. Several phantom and biological experiments indicate that the accelerated SALSA method with coherence factor (ASALSA-CF) can provide improved reconstructions and much faster convergence compared to existing sparse recovery methods.

Plant nuclear factor Y (NF-Y) B subunits confer drought tolerance and lead to improved corn yields on water-limited acres.

PubMed

Nelson, Donald E; Repetti, Peter P; Adams, Tom R; Creelman, Robert A; Wu, Jingrui; Warner, David C; Anstrom, Don C; Bensen, Robert J; Castiglioni, Paolo P; Donnarummo, Meghan G; Hinchey, Brendan S; Kumimoto, Roderick W; Maszle, Don R; Canales, Roger D; Krolikowski, Katherine A; Dotson, Stanton B; Gutterson, Neal; Ratcliffe, Oliver J; Heard, Jacqueline E

2007-10-16

Commercially improved crop performance under drought conditions has been challenging because of the complexity of the trait and the multitude of factors that influence yield. Here we report the results of a functional genomics approach that identified a transcription factor from the nuclear factor Y (NF-Y) family, AtNF-YB1, which acts through a previously undescribed mechanism to confer improved performance in Arabidopsis under drought conditions. An orthologous maize transcription factor, ZmNF-YB2, is shown to have an equivalent activity. Under water-limited conditions, transgenic maize plants with increased ZmNF-YB2 expression show tolerance to drought based on the responses of a number of stress-related parameters, including chlorophyll content, stomatal conductance, leaf temperature, reduced wilting, and maintenance of photosynthesis. These stress adaptations contribute to a grain yield advantage to maize under water-limited environments. The application of this technology has the potential to significantly impact maize production systems that experience drought.

Plant nuclear factor Y (NF-Y) B subunits confer drought tolerance and lead to improved corn yields on water-limited acres

PubMed Central

Nelson, Donald E.; Repetti, Peter P.; Adams, Tom R.; Creelman, Robert A.; Wu, Jingrui; Warner, David C.; Anstrom, Don C.; Bensen, Robert J.; Castiglioni, Paolo P.; Donnarummo, Meghan G.; Hinchey, Brendan S.; Kumimoto, Roderick W.; Maszle, Don R.; Canales, Roger D.; Krolikowski, Katherine A.; Dotson, Stanton B.; Gutterson, Neal; Ratcliffe, Oliver J.; Heard, Jacqueline E.

2007-01-01

Commercially improved crop performance under drought conditions has been challenging because of the complexity of the trait and the multitude of factors that influence yield. Here we report the results of a functional genomics approach that identified a transcription factor from the nuclear factor Y (NF-Y) family, AtNF-YB1, which acts through a previously undescribed mechanism to confer improved performance in Arabidopsis under drought conditions. An orthologous maize transcription factor, ZmNF-YB2, is shown to have an equivalent activity. Under water-limited conditions, transgenic maize plants with increased ZmNF-YB2 expression show tolerance to drought based on the responses of a number of stress-related parameters, including chlorophyll content, stomatal conductance, leaf temperature, reduced wilting, and maintenance of photosynthesis. These stress adaptations contribute to a grain yield advantage to maize under water-limited environments. The application of this technology has the potential to significantly impact maize production systems that experience drought. PMID:17923671

Factors limiting the establishment of canopy-forming algae on artificial structures

NASA Astrophysics Data System (ADS)

Cacabelos, Eva; Martins, Gustavo M.; Thompson, Richard; Prestes, Afonso C. L.; Azevedo, José Manuel N.; Neto, Ana I.

2016-11-01

Macroalgal canopies are important ecosystem engineers, contributing to coastal productivity and supporting a rich assemblage of associated flora and fauna. However, they are often absent from infrastructures such as coastal defences and there has been a worldwide decline in their distribution in urbanised coastal areas. The macroalga Fucus spiralis is the only high-shore canopy forming species present in the Azores. It is widely distributed in the archipelago but is never found on coastal infrastructures. Here we evaluate factors that may potentially limit its establishment on artificial structures. A number of observational and manipulative experiments were used to test the hypotheses that: (i) limited-dispersal ability limits the colonisation of new plants onto artificial structures, (ii) vertical substratum slope negatively influences the survivorship of recruits, and (iii) vertical substratum slope also negatively influences the survivorship and fitness of adults. Results showed that the limited dispersal from adult plants may be a more important factor than slope in limiting the species ability to colonise coastal infrastructures, since the vertical substratum slope does not affect its fitness or survivorship.

Ohm's Law, Batteries, and the Clean Energy Landscape

NASA Astrophysics Data System (ADS)

Balsara, Nitash

The need for creating safe electrolytes for lithium batteries is significant given the continued safety problems associated with current lithium-ion batteries. Nonflammable polymer electrolytes offer a possible solution but the rate of lithium ion transport is too low for practical applications. In this talk, I will discuss some of the fundamental factors that limit ion transport in polymers. Polymer electrolytes obey Ohm's Law, i.e. in the limit of small applied potentials, the current generated at steady state is proportional to the applied potential. Factors that determine the current generated will be determined using the continuum theory of Newman. Independent measurements of ion diffusion by pulsed-field gradient NMR will also be presented. The talk will end with a discussion of the possibility of commercializing all-solid batteries with polymer electrolytes.

Effect of living cellular sheets on the angiogenic potential of human microvascular endothelial cells.

PubMed

Villar, Cristina C; Zhao, Xiang R; Livi, Carolina B; Cochran, David L

2015-05-01

A fundamental issue limiting the efficacy of surgical approaches designed to correct periodontal mucogingival defects is that new tissues rely on limited sources of blood supply from the adjacent recipient bed. Accordingly, therapies based on tissue engineering that leverage local self-healing potential may represent promising alternatives for the treatment of mucogingival defects by inducing local vascularization. The aim of this study is to evaluate the effect of commercially available living cellular sheets (LCS) on the angiogenic potential of neonatal dermal human microvascular endothelial cells (HMVEC-dNeo). The effect of LCS on HMVEC-dNeo proliferation, migration, capillary tube formation, gene expression, and production of angiogenic factors was evaluated over time. LCS positively influenced HMVEC-dNeo proliferation and migration. Moreover, HMVEC-dNeo incubated with LCS showed transcriptional profiles different from those of untreated cells. Whereas increased expression of angiogenic genes predominated early on in response to LCS, late-phase responses were characterized by up- and downregulation of angiostatic and angiogenic genes. However, this trend was not confirmed at the protein level, as LCS induced increased production of most of the angiogenic factors tested (i.e., epidermal growth factor [EGF], heparin-binding EGF-like growth factor, interleukin 6, angiopoietin, platelet-derived growth factor-BB, placental growth factor, and vascular endothelial growth factor) throughout the investigational period. Finally, although LCS induced HMVEC-dNeo proliferation, migration, and expression of angiogenic factors, additional factors and environmental pressures are likely to be required to promote the development of complex, mesh-like vascular structures. LCS favor initial mechanisms that govern angiogenesis but failed to enhance or accelerate HMVEC-dNeo morphologic transition to complex vascular structures.

Combating Osteoarthritis through Stem Cell Therapies by Rejuvenating Cartilage: A Review

PubMed Central

Dubey, Navneet Kumar; Mishra, Viraj Krishna; Dubey, Rajni; Syed-Abdul, Shabbir; Wang, Joseph R.; Wang, Peter D.

2018-01-01

Knee osteoarthritis (OA) is a chronic degenerative disorder which could be distinguished by erosion of articular cartilage, pain, stiffness, and crepitus. Not only aging-associated alterations but also the metabolic factors such as hyperglycemia, dyslipidemia, and obesity affect articular tissues and may initiate or exacerbate the OA. The poor self-healing ability of articular cartilage due to limited regeneration in chondrocytes further adversely affects the osteoarthritic microenvironment. Traditional and current surgical treatment procedures for OA are limited and incapable to reverse the damage of articular cartilage. To overcome these limitations, cell-based therapies are currently being employed to repair and regenerate the structure and function of articular tissues. These therapies not only depend upon source and type of stem cells but also on environmental conditions, growth factors, and chemical and mechanical stimuli. Recently, the pluripotent and various multipotent mesenchymal stem cells have been employed for OA therapy, due to their differentiation potential towards chondrogenic lineage. Additionally, the stem cells have also been supplemented with growth factors to achieve higher healing response in osteoarthritic cartilage. In this review, we summarized the current status of stem cell therapies in OA pathophysiology and also highlighted the potential areas of further research needed in regenerative medicine. PMID:29765416

Nanog reverses the effects of organismal aging on mesenchymal stem cell proliferation and myogenic differentiation potential

PubMed Central

Han, Juhee; Mistriotis, Panagiotis; Lei, Pedro; Wang, Dan; Liu, Song; Andreadis, Stelios T.

2012-01-01

Although the therapeutic potential of mesenchymal stem cells (MSC) is widely accepted, loss of cell function due to donor aging or culture senescence are major limiting factors hampering their clinical application. Our laboratory recently showed that MSC originating from older donors suffer from limited proliferative capacity and significantly reduced myogenic differentiation potential. This is a major concern, as the patients most likely to suffer from cardiovascular disease are elderly. Here we tested the hypothesis that a single pluripotency associated transcription factor, namely Nanog, may reverse the proliferation and differentiation potential of BM-MSC from adult donors. Microarray analysis showed that adult (a)BM-MSC expressing Nanog clustered close to Nanog-expressing neonatal cells. Nanog markedly upregulated genes involved in cell cycle, DNA replication and DNA damage repair and enhanced the proliferation rate and clonogenic capacity of aBM-MSC. Notably, Nanog reversed the myogenic differentiation potential and restored the contractile function of aBM-MSC to a similar level as that of neonatal (n)BM-MSC. The effect of Nanog on contractility was mediated – at least in part - through activation of the TGF-β pathway by diffusible factors secreted in the conditioned medium of Nanog-expressing BM-MSC. Overall, our results suggest that Nanog may be used to overcome the effects of organismal aging on aBM-MSC, thereby increasing the potential of MSC from aged donors for cellular therapy and tissue regeneration. PMID:22949105

Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet

PubMed Central

Liu, Xinsheng; Nie, Yuqin; Luo, Tianxiang; Yu, Jiehui; Shen, Wei; Zhang, Lin

2016-01-01

Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii) and juniper (Juniperus saltuaria) treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0°C. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change. PMID:27468289

Multilevel Examination of Burnout among High School Staff: Importance of Staff and School Factors

ERIC Educational Resources Information Center

O'Brennan, Lindsey; Pas, Elise; Bradshaw, Catherine

2017-01-01

Previous studies have linked teacher burnout with job performance, satisfaction, and retention; however, there has been limited exploration of potential individual and school contextual factors that may influence burnout. The current study examined high school staff members' reports of burnout as they relate to staff demographics and perceptions…

A basic fibroblast growth factor analog for protection and mitigation against acute radiation syndromes.

PubMed

Casey-Sawicki, Kate; Zhang, Mei; Kim, Sunghee; Zhang, Amy; Zhang, Steven B; Zhang, Zhenhuan; Singh, Ravi; Yang, Shanmin; Swarts, Steven; Vidyasagar, Sadasivan; Zhang, Lurong; Zhang, Aiguo; Okunieff, Paul

2014-06-01

The effects of fibroblast growth factors and their potential as broad-spectrum agents to treat and mitigate radiation injury have been studied extensively over the past two decades. This report shows that a peptide mimetic of basic fibroblast growth factor (FGF-P) protects and mitigates against acute radiation syndromes. FGF-P attenuates both sepsis and bleeding in a radiation-induced bone marrow syndrome model and reduces the severity of gastrointestinal and cutaneous syndromes; it should also mitigate combined injuries. FGF-2 and FGF-P induce little or no deleterious inflammation or vascular leakage, which distinguishes them from most other growth factors, angiogenic factors, and cytokines. Although recombinant FGFs have proven safe in several ongoing clinical trials, they are expensive to synthesize, can only be produced in limited quantity, and have limited shelf life. FGF-P mimics the advantageous features of FGF-2 without these disadvantages. This paper shows that FGF-P not only has the potential to be a potent yet safe broad-spectrum medical countermeasure that mitigates acute radiotoxicity but also holds promise for thermal burns, ischemic wound healing, tissue engineering, and stem-cell regeneration.

17 CFR 229.904 - (Item 904) Risk factors and other considerations.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-up transaction on investors in each partnership, including, but not limited to: (1) The potential... difference(s). Instruction to Item 904. The requirement to quantify the effects of the roll-up transaction... partnerships is identified as a potential benefit of the roll-up transaction, the amount of cost savings and a...

17 CFR 229.904 - (Item 904) Risk factors and other considerations.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-up transaction on investors in each partnership, including, but not limited to: (1) The potential... difference(s). Instruction to Item 904. The requirement to quantify the effects of the roll-up transaction... partnerships is identified as a potential benefit of the roll-up transaction, the amount of cost savings and a...

17 CFR 229.904 - (Item 904) Risk factors and other considerations.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-up transaction on investors in each partnership, including, but not limited to: (1) The potential... difference(s). Instruction to Item 904. The requirement to quantify the effects of the roll-up transaction... partnerships is identified as a potential benefit of the roll-up transaction, the amount of cost savings and a...

Report of an Army Workshop on Convergence Forecasting: Mechanochemical Transduction

DTIC Science & Technology

2012-07-01

Breakout Session 1, Group 1.........................................................................10  Figure 3. Potential Ultrasound -Mediated...Capabilities in Mechanochemical Transduction ..........10  Figure 4. Factors that Limit Potential Ultrasound -Mediated Mechanochemical Transduction... ultrasound as a mechanism to induce mechanochemical reactions. If ultrasound is to be used to provide the mechanical energy for subsequent chemical

Identification of cocoa trees combining high yield potential and resistance to diseases in segregating progenies In Ecuador

USDA-ARS?s Scientific Manuscript database

Diseases and low yielding planting material are the main factors limiting production of “fine” or “flavour” cocoa in Ecuador. This makes it necessary to develop modern varieties capable of overcoming these limitations. During the 1960s and 1970s INIAP tested several progenies from selected crosses...

Familiality of factor analysis-derived YBOCS dimensions in OCD-affected sibling pairs from the OCD Collaborative Genetics Study.

PubMed

Hasler, Gregor; Pinto, Anthony; Greenberg, Benjamin D; Samuels, Jack; Fyer, Abby J; Pauls, David; Knowles, James A; McCracken, James T; Piacentini, John; Riddle, Mark A; Rauch, Scott L; Rasmussen, Steven A; Willour, Virginia L; Grados, Marco A; Cullen, Bernadette; Bienvenu, O Joseph; Shugart, Yin-Yao; Liang, Kung-Yee; Hoehn-Saric, Rudolf; Wang, Ying; Ronquillo, Jonne; Nestadt, Gerald; Murphy, Dennis L

2007-03-01

Identification of familial, more homogenous characteristics of obsessive-compulsive disorder (OCD) may help to define relevant subtypes and increase the power of genetic and neurobiological studies of OCD. While factor-analytic studies have found consistent, clinically meaningful OCD symptom dimensions, there have been only limited attempts to evaluate the familiality and potential genetic basis of such dimensions. Four hundred eighteen sibling pairs with OCD were evaluated using the Structured Clinical Interview for DSM-IV and the Yale-Brown Obsessive Compulsive Scale (YBOCS) Symptom Checklist and Severity scales. After controlling for sex, age, and age of onset, robust sib-sib intraclass correlations were found for two of the four YBOCS factors: Factor IV (hoarding obsessions and compulsions (p = .001) and Factor I (aggressive, sexual, and religious obsessions, and checking compulsions; p = .002). Smaller, but still significant, familiality was found for Factor III (contamination/cleaning; p = .02) and Factor II (symmetry/ordering/arranging; p = .04). Limiting the sample to female subjects more than doubled the familiality estimates for Factor II (p = .003). Among potentially relevant comorbid conditions for genetic studies, bipolar I/II and major depressive disorder were strongly associated with Factor I (p < .001), whereas ADHD, alcohol dependence, and bulimia were associated with Factor II (p < .01). Factor-analyzed OCD symptom dimensions in sibling pairs with OCD are familial with some gender-dependence, exhibit relatively specific relationships to comorbid psychiatric disorders and thus may be useful as refined phenotypes for molecular genetic studies of OCD.

UG311, An Oncofetal Marker Lost with Prostate Cancer Progression

DTIC Science & Technology

2001-04-01

CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT Unclassified Unclassified...that the IGF2R facilitates the degradation of IGF-2 by transporting IGF-2 to lysozomes, thereby limiting the signal potentiated by the growth factor...integrin mediated migration. IGF-1 had no effect on this activity. IGFBP-1 is expressed in the placenta [105] where it may limit trophoblast invasion

Finite Element Analysis in Concurrent Processing: Computational Issues

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw; Watson, Brian; Vanderplaats, Garrett

2004-01-01

The purpose of this research is to investigate the potential application of new methods for solving large-scale static structural problems on concurrent computers. It is well known that traditional single-processor computational speed will be limited by inherent physical limits. The only path to achieve higher computational speeds lies through concurrent processing. Traditional factorization solution methods for sparse matrices are ill suited for concurrent processing because the null entries get filled, leading to high communication and memory requirements. The research reported herein investigates alternatives to factorization that promise a greater potential to achieve high concurrent computing efficiency. Two methods, and their variants, based on direct energy minimization are studied: a) minimization of the strain energy using the displacement method formulation; b) constrained minimization of the complementary strain energy using the force method formulation. Initial results indicated that in the context of the direct energy minimization the displacement formulation experienced convergence and accuracy difficulties while the force formulation showed promising potential.

Analysis of rainfall-induced slope instability using a field of local factor of safety

USGS Publications Warehouse

Lu, Ning; Şener-Kaya, Başak; Wayllace, Alexandra; Godt, Jonathan W.

2012-01-01

Slope-stability analyses are mostly conducted by identifying or assuming a potential failure surface and assessing the factor of safety (FS) of that surface. This approach of assigning a single FS to a potentially unstable slope provides little insight on where the failure initiates or the ultimate geometry and location of a landslide rupture surface. We describe a method to quantify a scalar field of FS based on the concept of the Coulomb stress and the shift in the state of stress toward failure that results from rainfall infiltration. The FS at each point within a hillslope is called the local factor of safety (LFS) and is defined as the ratio of the Coulomb stress at the current state of stress to the Coulomb stress of the potential failure state under the Mohr-Coulomb criterion. Comparative assessment with limit-equilibrium and hybrid finite element limit-equilibrium methods show that the proposed LFS is consistent with these approaches and yields additional insight into the geometry and location of the potential failure surface and how instability may initiate and evolve with changes in pore water conditions. Quantitative assessments applying the new LFS field method to slopes under infiltration conditions demonstrate that the LFS has the potential to overcome several major limitations in the classical FS methodologies such as the shape of the failure surface and the inherent underestimation of slope instability. Comparison with infinite-slope methods, including a recent extension to variably saturated conditions, shows further enhancement in assessing shallow landslide occurrence using the LFS methodology. Although we use only a linear elastic solution for the state of stress with no post-failure analysis that require more sophisticated elastoplastic or other theories, the LFS provides a new means to quantify the potential instability zones in hillslopes under variably saturated conditions using stress-field based methods.

Psychological Factors and Conditioned Pain Modulation: A Meta-Analysis.

PubMed

Nahman-Averbuch, Hadas; Nir, Rony-Reuven; Sprecher, Elliot; Yarnitsky, David

2016-06-01

Conditioned pain modulation (CPM) responses may be affected by psychological factors such as anxiety, depression, and pain catastrophizing; however, most studies on CPM do not address these relations as their primary outcome. The aim of this meta-analysis was to analyze the findings regarding the associations between CPM responses and psychological factors in both pain-free individuals and pain patients. After a comprehensive PubMed search, 37 articles were found to be suitable for inclusion. Analyses used DerSimonian and Laird's random-effects model on Fisher's z-transforms of correlations; potential publication bias was tested using funnel plots and Egger's regression test for funnel plot asymmetry. Six meta-analyses were performed examining the correlations between anxiety, depression, and pain catastrophizing, and CPM responses in healthy individuals and pain patients. No significant correlations between CPM responses and any of the examined psychological factors were found. However, a secondary analysis, comparing modality-specific CPM responses and psychological factors in healthy individuals, revealed the following: (1) pressure-based CPM responses were correlated with anxiety (grand mean correlation in original units r=-0.1087; 95% confidence limits, -0.1752 to -0.0411); (2) heat-based CPM was correlated with depression (r=0.2443; 95% confidence limits, 0.0150 to 0.4492); and (3) electrical-based CPM was correlated with pain catastrophizing levels (r=-0.1501; 95% confidence limits, -0.2403 to -0.0574). Certain psychological factors seem to be associated with modality-specific CPM responses in healthy individuals. This potentially supports the notion that CPM paradigms evoked by different stimulation modalities represent different underlying mechanisms.

WOMEN’S EMPOWERMENT AS A PROTECTIVE FACTOR AGAINST INTIMATE PARTNER VIOLENCE IN BANGLADESH: A QUALITATIVE EXPLORATION OF THE PROCESS AND LIMITATIONS OF ITS INFLUENCE

PubMed Central

Schuler, Sidney Ruth; Lenzi, Rachel; Badal, Shamsul Huda; Bates, Lisa M.

2016-01-01

Literature on the relationship between intimate partner violence (IPV) against women and women’s empowerment is contradictory. Findings from a recent survey in rural Bangladesh suggest that empowerment is becoming protective even though IPV rates remain high. We construct qualitative case studies exploring factors and social processes underlying relationships between empowerment and IPV in four villages. Empowerment may be protective against IPV in the aggregate, but this relationship can be subverted at the micro-level. Interventions are needed to reinforce the potential of empowerment to reduce IPV and counteract factors like geographic isolation and limited employment opportunities that inhibit empowerment. PMID:27486126

Electronic simulation of the supported liquid membrane in electromembrane extraction systems: Improvement of the extraction by precise periodical reversing of the field polarity.

PubMed

Moazami, Hamid Reza; Nojavan, Saeed; Zahedi, Pegah; Davarani, Saied Saeed Hosseiny

2014-09-02

In order to understand the limitations of electromebrane extraction procedure better, a simple equivalent circuit has been proposed for a supported liquid membrane consisting of a resistor and a low leakage capacitor in series. To verify the equivalent circuit, it was subjected to a simulated periodical polarity changing potential and the resulting time variation of the current was compared with that of a real electromembrane extraction system. The results showed a good agreement between the simulated current patterns and those of the real ones. In order to investigate the impact of various limiting factors, the corresponding values of the equivalent circuit were estimated for a real electromembrane extraction system and were attributed to the physical parameters of the extraction system. A dual charge transfer mechanism was proposed for electromembrane extraction by combining general migration equation and fundamental aspects derived from the simulation. Dual mechanism comprises a current dependent contribution of analyte in total current and could support the possibility of an improvement in performance of an electromembrane extraction by application of an asymmetric polarity changing potential. The optimization of frequency and duty cycle of the asymmetric polarity exchanging potential resulted in a higher recovery (2.17 times greater) in comparison with the conventional electromebrane extraction. The simulation also provided more quantitative approaches toward the investigation of the mechanism of extraction and contribution of different limiting factors in electromembrane extraction. Results showed that the buildup of the double layer is the main limiting factor and the Joule heating has lesser impact on the performance of an electromebrane extraction system. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of Spatially-Based Emission Factors from Real-Time Measurements of Gaseous Pollutants Using Cermet Sensors

DTIC Science & Technology

2005-03-01

produce a current-limited steady state output potential that follows the Nernst equation (Fraden 1993): E = Eo + ((RT)/nF)ln(CO/CR) (2) CO...temperature, EO: electrode potential at standard state. Nernst equation governs many half-cell reactions in electrochemical cells. The cell...voltammetric cell, the analytes react (oxidize or reduce) at very characteristic potentials according to the following simplified equation (Smyth

Calculation Method of Lateral Strengths and Ductility Factors of Constructions with Shear Walls of Different Ductility

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

Yamaguchi, Nobuyoshi; Nakao, Masato; Murakami, Masahide

2008-07-08

For seismic design, ductility-related force modification factors are named R factor in Uniform Building Code of U.S, q factor in Euro Code 8 and Ds (inverse of R) factor in Japanese Building Code. These ductility-related force modification factors for each type of shear elements are appeared in those codes. Some constructions use various types of shear walls that have different ductility, especially for their retrofit or re-strengthening. In these cases, engineers puzzle the decision of force modification factors of the constructions. Solving this problem, new method to calculate lateral strengths of stories for simple shear wall systems is proposed andmore » named 'Stiffness--Potential Energy Addition Method' in this paper. This method uses two design lateral strengths for each type of shear walls in damage limit state and safety limit state. Two lateral strengths of stories in both limit states are calculated from these two design lateral strengths for each type of shear walls in both limit states. Calculated strengths have the same quality as values obtained by strength addition method using many steps of load-deformation data of shear walls. The new method to calculate ductility factors is also proposed in this paper. This method is based on the new method to calculate lateral strengths of stories. This method can solve the problem to obtain ductility factors of stories with shear walls of different ductility.« less

The Nutraceutical Bioavailability Classification Scheme: Classifying Nutraceuticals According to Factors Limiting their Oral Bioavailability.

PubMed

McClements, David Julian; Li, Fang; Xiao, Hang

2015-01-01

The oral bioavailability of a health-promoting dietary component (nutraceutical) may be limited by various physicochemical and physiological phenomena: liberation from food matrices, solubility in gastrointestinal fluids, interaction with gastrointestinal components, chemical degradation or metabolism, and epithelium cell permeability. Nutraceutical bioavailability can therefore be improved by designing food matrices that control their bioaccessibility (B*), absorption (A*), and transformation (T*) within the gastrointestinal tract (GIT). This article reviews the major factors influencing the gastrointestinal fate of nutraceuticals, and then uses this information to develop a new scheme to classify the major factors limiting nutraceutical bioavailability: the nutraceutical bioavailability classification scheme (NuBACS). This new scheme is analogous to the biopharmaceutical classification scheme (BCS) used by the pharmaceutical industry to classify drug bioavailability, but it contains additional factors important for understanding nutraceutical bioavailability in foods. The article also highlights potential strategies for increasing the oral bioavailability of nutraceuticals based on their NuBACS designation (B*A*T*).

Stochastic quasi-Newton molecular simulations

NASA Astrophysics Data System (ADS)

Chau, C. D.; Sevink, G. J. A.; Fraaije, J. G. E. M.

2010-08-01

We report a new and efficient factorized algorithm for the determination of the adaptive compound mobility matrix B in a stochastic quasi-Newton method (S-QN) that does not require additional potential evaluations. For one-dimensional and two-dimensional test systems, we previously showed that S-QN gives rise to efficient configurational space sampling with good thermodynamic consistency [C. D. Chau, G. J. A. Sevink, and J. G. E. M. Fraaije, J. Chem. Phys. 128, 244110 (2008)10.1063/1.2943313]. Potential applications of S-QN are quite ambitious, and include structure optimization, analysis of correlations and automated extraction of cooperative modes. However, the potential can only be fully exploited if the computational and memory requirements of the original algorithm are significantly reduced. In this paper, we consider a factorized mobility matrix B=JJT and focus on the nontrivial fundamentals of an efficient algorithm for updating the noise multiplier J . The new algorithm requires O(n2) multiplications per time step instead of the O(n3) multiplications in the original scheme due to Choleski decomposition. In a recursive form, the update scheme circumvents matrix storage and enables limited-memory implementation, in the spirit of the well-known limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) method, allowing for a further reduction of the computational effort to O(n) . We analyze in detail the performance of the factorized (FSU) and limited-memory (L-FSU) algorithms in terms of convergence and (multiscale) sampling, for an elementary but relevant system that involves multiple time and length scales. Finally, we use this analysis to formulate conditions for the simulation of the complex high-dimensional potential energy landscapes of interest.

Trade-offs for food production, nature conservation and climate limit the terrestrial carbon dioxide removal potential.

PubMed

Boysen, Lena R; Lucht, Wolfgang; Gerten, Dieter

2017-10-01

Large-scale biomass plantations (BPs) are a common factor in climate mitigation scenarios as they promise double benefits: extracting carbon from the atmosphere and providing a renewable energy source. However, their terrestrial carbon dioxide removal (tCDR) potentials depend on important factors such as land availability, efficiency of capturing biomass-derived carbon and the timing of operation. Land availability is restricted by the demands of future food production depending on yield increases and population growth, by requirements for nature conservation and, with respect to climate mitigation, avoiding unfavourable albedo changes. We integrate these factors in one spatially explicit biogeochemical simulation framework to explore the tCDR opportunity space on land available after these constraints are taken into account, starting either in 2020 or 2050, and lasting until 2100. We find that assumed future needs for nature protection and food production strongly limit tCDR potentials. BPs on abandoned crop and pasture areas (~1,300 Mha in scenarios of either 8.0 billion people and yield gap reductions of 25% until 2020 or 9.5 billion people and yield gap reductions of 50% until 2050) could, theoretically, sequester ~100 GtC in land carbon stocks and biomass harvest by 2100. However, this potential would be ~80% lower if only cropland was available or ~50% lower if albedo decreases were considered as a factor restricting land availability. Converting instead natural forest, shrubland or grassland into BPs could result in much larger tCDR potentials ̶ but at high environmental costs (e.g. biodiversity loss). The most promising avenue for effective tCDR seems to be improvement of efficient carbon utilization pathways, changes in dietary trends or the restoration of marginal lands for the implementation of tCDR. © 2017 John Wiley & Sons Ltd.

Disentangling the effects of low pH and metal mixture toxicity on macroinvertebrate diversity

USGS Publications Warehouse

Fornaroli, Riccardo; Ippolito, Alessio; Tolkkinen, Mari J.; Mykrä, Heikki; Muotka, Timo; Balistrieri, Laurie S.; Schmidt, Travis S.

2018-01-01

One of the primary goals of biological assessment of streams is to identify which of a suite of chemical stressors is limiting their ecological potential. Elevated metal concentrations in streams are often associated with low pH, yet the effects of these two potentially limiting factors of freshwater biodiversity are rarely considered to interact beyond the effects of pH on metal speciation. Using a dataset from two continents, a biogeochemical model of the toxicity of metal mixtures (Al, Cd, Cu, Pb, Zn) and quantile regression, we addressed the relative importance of both pH and metals as limiting factors for macroinvertebrate communities. Current environmental quality standards for metals proved to be protective of stream macroinvertebrate communities and were used as a starting point to assess metal mixture toxicity. A model of metal mixture toxicity accounting for metal interactions was a better predictor of macroinvertebrate responses than a model considering individual metal toxicity. We showed that the direct limiting effect of pH on richness was of the same magnitude as that of chronic metal toxicity, independent of its influence on the availability and toxicity of metals. By accounting for the direct effect of pH on macroinvertebrate communities, we were able to determine that acidic streams supported less diverse communities than neutral streams even when metals were below no-effect thresholds. Through a multivariate quantile model, we untangled the limiting effect of both pH and metals and predicted the maximum diversity that could be expected at other sites as a function of these variables. This model can be used to identify which of the two stressors is more limiting to the ecological potential of running waters.

Disentangling the effects of low pH and metal mixture toxicity on macroinvertebrate diversity.

PubMed

Fornaroli, Riccardo; Ippolito, Alessio; Tolkkinen, Mari J; Mykrä, Heikki; Muotka, Timo; Balistrieri, Laurie S; Schmidt, Travis S

2018-04-01

One of the primary goals of biological assessment of streams is to identify which of a suite of chemical stressors is limiting their ecological potential. Elevated metal concentrations in streams are often associated with low pH, yet the effects of these two potentially limiting factors of freshwater biodiversity are rarely considered to interact beyond the effects of pH on metal speciation. Using a dataset from two continents, a biogeochemical model of the toxicity of metal mixtures (Al, Cd, Cu, Pb, Zn) and quantile regression, we addressed the relative importance of both pH and metals as limiting factors for macroinvertebrate communities. Current environmental quality standards for metals proved to be protective of stream macroinvertebrate communities and were used as a starting point to assess metal mixture toxicity. A model of metal mixture toxicity accounting for metal interactions was a better predictor of macroinvertebrate responses than a model considering individual metal toxicity. We showed that the direct limiting effect of pH on richness was of the same magnitude as that of chronic metal toxicity, independent of its influence on the availability and toxicity of metals. By accounting for the direct effect of pH on macroinvertebrate communities, we were able to determine that acidic streams supported less diverse communities than neutral streams even when metals were below no-effect thresholds. Through a multivariate quantile model, we untangled the limiting effect of both pH and metals and predicted the maximum diversity that could be expected at other sites as a function of these variables. This model can be used to identify which of the two stressors is more limiting to the ecological potential of running waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Blood Doping Improves Endurance and Heat Tolerance, Studies Say.

ERIC Educational Resources Information Center

Duda, Marty

1987-01-01

Recent research on blood doping is reviewed, focusing on how the practice may help to determine what factors limit human performance, particularly regarding its potential benefit as an aid in thermal regulation. (CB)

42 CFR 410.16 - Initial preventive physical examination: Conditions for and limitations on coverage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... potential (risk factors) for depression, including current or past experiences with depression or other mood... of depression, which the physician or other qualified nonphysician practitioner may select from...

42 CFR 410.16 - Initial preventive physical examination: Conditions for and limitations on coverage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... potential (risk factors) for depression, including current or past experiences with depression or other mood... of depression, which the physician or other qualified nonphysician practitioner may select from...

42 CFR 410.16 - Initial preventive physical examination: Conditions for and limitations on coverage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... potential (risk factors) for depression, including current or past experiences with depression or other mood... of depression, which the physician or other qualified nonphysician practitioner may select from...

Current limitations into the application of virtual reality to mental health research.

PubMed

Huang, M P; Alessi, N E

1998-01-01

Virtual Reality (VR) environments have significant potential as a tool in mental health research, but are limited by technical factors and by mental health research factors. Technical difficulties include cost and complexity of virtual environment creation. Mental health research difficulties include current inadequacy of standards to specify needed details for virtual environment design. Technical difficulties are disappearing with technological advances, but the mental health research difficulties will take a concerted effort to overcome. Some of this effort will need to be directed at the formation of collaborative projects and standards for how such collaborations should proceed.

A comparative analysis of longitudinal computed tomography and histopathology for evaluating the potential of mesenchymal stem cells in mitigating radiation-induced pulmonary fibrosis.

PubMed

Perez, Jessica R; Lee, Sangkyu; Ybarra, Norma; Maria, Ola; Serban, Monica; Jeyaseelan, Krishinima; Wang, Li Ming; Seuntjens, Jan; Naqa, Issam El

2017-08-22

Radiation-induced pulmonary fibrosis (RIPF) is a debilitating side effect that occurs in up to 30% of thoracic irradiations in breast and lung cancer patients. RIPF remains a major limiting factor to dose escalation and an obstacle to applying more promising new treatments for cancer cure. Limited treatment options are available to mitigate RIPF once it occurs, but recently, mesenchymal stem cells (MSCs) and a drug treatment stimulating endogenous stem cells (GM-CSF) have been investigated for their potential in preventing this disease onset. In a pre-clinical rat model, we contrasted the application of longitudinal computed tomography (CT) imaging and classical histopathology to quantify RIPF and to evaluate the potential of MSCs in mitigating RIPF. Our results on histology demonstrate promises when MSCs are injected endotracheally (but not intravenously). While our CT analysis highlights the potential of GM-CSF treatment. Advantages and limitations of both analytical methods are contrasted in the context of RIPF.

Potentially harmful microalgal distribution in an area of the NW Adriatic coastline: Sampling procedure and correlations with environmental factors

NASA Astrophysics Data System (ADS)

Penna, Antonella; Ingarao, Cristina; Ercolessi, Manuela; Rocchi, Marco; Penna, Nunzio

2006-10-01

In this study, the trend of potentially Harmful Algal (HA) taxa (genera and species), was analysed along a coastal area of the NW Adriatic Sea on a monthly scale. The study included the use of a phytoplankton net for sample collection. The investigation was carried out in four sampling stations characterised by different ecological features. The composition of potentially HA phytoplankton taxa and their succession were related to the environmental factors. The potentially HA group abundance accounted for 8% of all the phytoplankton taxa considered. Multivariate analyses of environmental factors suggested that potentially HA taxa are sensitive to phosphate content: potential DSP-YTX (Diarrhetic Shellfish Poisoning-Yessotoxin) producers were positively correlated with P content ( p = 0.023), while potential ASP (Amnesic Shellfish Poisoning) producers were negatively correlated with P content ( p = 0.006). Phosphorus could be considered to be the limiting factor for phytoplankton taxa density in the NW Adriatic Sea. There was a highly positive correlation between the occurrences of potentially HA taxa and low values of salinity ( p = 0.001 for potential producers of ASP, p = 0.029 for potential DSP-YTX producers). The counting of potential HA dinoflagellates in net samples represented a more accurate estimation of potential HA abundances in the water column making it possible to concentrate a greater number of potential HA dinoflagellate cells by net sampling along the entire water column rather than by sampling only at the surface as in routine monitoring procedures.

Regulating the advertising and promotion of stem cell therapies.

PubMed

von Tigerstrom, Barbara

2017-10-01

There are widespread concerns with the ways in which 'unproven' stem cell therapies are advertised to patients. This article explores the potential and limits of using laws that regulate advertising and promotion as a tool to address these concerns. It examines general consumer protection laws and laws and policies on advertising medical products and services, focusing on the USA, Canada and Australia. The content of existing laws and policies covers most of the marketing practices that cause concern, but several systemic factors are likely to limit enforcement efforts. Potential reforms in Australia that would prevent direct-to-consumer advertising of autologous cell therapies are justified in principle and should be considered by other jurisdictions, but again face important practical limits to their effectiveness.

Enhanced factoring with a bose-einstein condensate.

PubMed

Sadgrove, Mark; Kumar, Sanjay; Nakagawa, Ken'ichi

2008-10-31

We present a novel method to realize analog sum computation with a Bose-Einstein condensate in an optical lattice potential subject to controlled phase jumps. We use the method to implement the Gauss sum algorithm for factoring numbers. By exploiting higher order quantum momentum states, we are able to improve the algorithm's accuracy beyond the limits of the usual classical implementation.

Limitations and plausibility of the Pliocene lignite hypothesis in explaining the etiology of Balkan endemic nephropathy.

PubMed

Maharaj, S V M

2014-01-01

Balkan endemic nephropathy (BEN) is a chronic, tubulointerstitial renal disease often accompanied by urothelial cancer that has a lethality of nearly 100%. One of the many factors that have been proposed to play an etiological role in BEN is exposure to organic compounds from Pliocene lignite coal deposits via the drinking water in endemic areas. The objective of this study was to systematically evaluate the role of the tenets of the Pliocene lignite hypothesis in the etiology of BEN in order to provide an improved understanding of the hypothesis for colleagues and patients alike. A comprehensive compilation of the possible limitations of the hypothesis, with each limitation addressed in turn is presented. The Pliocene lignite hypothesis can best account for, is consistent with, or has the potential to explain the evidence associated with the myriad of factors related to BEN. Residents of endemic areas are exposed to complex mixtures containing hundreds of organic compounds at varying doses and their potentially more toxic (including nephrotoxic) and/or carcinogenic metabolites; however, a multifactorial etiology of BEN appears most likely.

Suitable Environmental Ranges for Potential Coral Reef Habitats in the Tropical Ocean

PubMed Central

Guan, Yi; Hohn, Sönke; Merico, Agostino

2015-01-01

Coral reefs are found within a limited range of environmental conditions or tolerance limits. Estimating these limits is a critical prerequisite for understanding the impacts of climate change on the biogeography of coral reefs. Here we used the diagnostic model ReefHab to determine the current environmental tolerance limits for coral reefs and the global distribution of potential coral reef habitats as a function of six factors: temperature, salinity, nitrate, phosphate, aragonite saturation state, and light. To determine these tolerance limits, we extracted maximum and minimum values of all environmental variables in corresponding locations where coral reefs are present. We found that the global, annually averaged tolerance limits for coral reefs are 21.7—29.6 °C for temperature, 28.7—40.4 psu for salinity, 4.51 μmol L-1 for nitrate, 0.63 μmol L-1 for phosphate, and 2.82 for aragonite saturation state. The averaged minimum light intensity in coral reefs is 450 μmol photons m-2 s-1. The global area of potential reef habitats calculated by the model is 330.5 × 103 km2. Compared with previous studies, the tolerance limits for temperature, salinity, and nutrients have not changed much, whereas the minimum value of aragonite saturation in coral reef waters has decreased from 3.28 to 2.82. The potential reef habitat area calculated with ReefHab is about 121×103 km2 larger than the area estimated from the charted reefs, suggesting that the growth potential of coral reefs is higher than currently observed. PMID:26030287

Suitable environmental ranges for potential coral reef habitats in the tropical ocean.

PubMed

Guan, Yi; Hohn, Sönke; Merico, Agostino

2015-01-01

Coral reefs are found within a limited range of environmental conditions or tolerance limits. Estimating these limits is a critical prerequisite for understanding the impacts of climate change on the biogeography of coral reefs. Here we used the diagnostic model ReefHab to determine the current environmental tolerance limits for coral reefs and the global distribution of potential coral reef habitats as a function of six factors: temperature, salinity, nitrate, phosphate, aragonite saturation state, and light. To determine these tolerance limits, we extracted maximum and minimum values of all environmental variables in corresponding locations where coral reefs are present. We found that the global, annually averaged tolerance limits for coral reefs are 21.7-29.6 °C for temperature, 28.7-40.4 psu for salinity, 4.51 μmol L-1 for nitrate, 0.63 μmol L-1 for phosphate, and 2.82 for aragonite saturation state. The averaged minimum light intensity in coral reefs is 450 μmol photons m-2 s-1. The global area of potential reef habitats calculated by the model is 330.5 × 103 km2. Compared with previous studies, the tolerance limits for temperature, salinity, and nutrients have not changed much, whereas the minimum value of aragonite saturation in coral reef waters has decreased from 3.28 to 2.82. The potential reef habitat area calculated with ReefHab is about 121×103 km2 larger than the area estimated from the charted reefs, suggesting that the growth potential of coral reefs is higher than currently observed.

Factors affecting the accumulation of phytoplankton biomass in Irish estuaries and nearshore coastal waters: A conceptual model

NASA Astrophysics Data System (ADS)

O'Boyle, Shane; Wilkes, Robert; McDermott, Georgina; Ní Longphuirt, Sorcha; Murray, Clare

2015-03-01

A multivariate statistical approach was used to investigate the response of phytoplankton in Irish estuaries and nearshore coastal waters to nutrient enrichment and to examine the factors which modulate this response. The analysis suggests that while many estuaries are nutrient-enriched, relatively few display phytoplankton-related symptoms of eutrophication as the response to nutrients is primarily affected by insufficient retention time, in some by inadequate light availability, and only rarely by both factors acting together. Nearshore coastal waters are nitrogen (N) and silica (Si) limited in summer, but in some nearshore waters along the south coast, where N is elevated, phosphorus (P) is potentially limiting. The reduction in P loadings to estuarine waters is likely to lead to an improvement in the eutrophication status of these mainly P-limited waters. The disproportionate reduction in loadings of P compared to N (52% versus 24%, since the early 1990s), and the potential weakening of the estuarine N filter, as eutrophication symptoms lessen, may result in the downstream movement of nitrogen to N-limited coastal waters. These findings support the view that an integrated dual-nutrient reduction strategy is required to address eutrophication along the freshwater-marine continuum. The outcome of the analysis is a conceptual model which is of direct value and use to water managers in determining the relative susceptibility of these waters to nutrient enrichment. This understanding can in turn be used to develop informed programmes of measures which are targeted and ultimately cost effective.

APPLICATIONS OF ELECTROCHEMICAL IMMUNOSENSORS TO ENVIRONMENTAL MONITORING

EPA Science Inventory

This paper discusses basic electrochemical immunoassay technology. Factors limiting the practical application of antibodies to anlaytical problems are also presented. It addresses the potential use of immunoassay methods based on electrochemical detection for the analysis of env...

Model evaluation of the phytoextraction potential of heavy metal hyperaccumulators and non-hyperaccumulators.

PubMed

Liang, Hong-Ming; Lin, Ting-Hsiang; Chiou, Jeng-Min; Yeh, Kuo-Chen

2009-06-01

Evaluation of the remediation ability of zinc/cadmium in hyper- and non-hyperaccumulator plant species through greenhouse studies is limited. To bridge the gap between greenhouse studies and field applications for phytoextraction, we used published data to examine the partitioning of heavy metals between plants and soil (defined as the bioconcentration factor). We compared the remediation ability of the Zn/Cd hyperaccumulators Thlaspi caerulescens and Arabidopsis halleri and the non-hyperaccumulators Nicotiana tabacum and Brassica juncea using a hierarchical linear model (HLM). A recursive algorithm was then used to evaluate how many harvest cycles were required to clean a contaminated site to meet Taiwan Environmental Protection Agency regulations. Despite the high bioconcentration factor of both hyperaccumulators, metal removal was still limited because of the plants' small biomass. Simulation with N. tabacum and the Cadmium model suggests further study and development of plants with high biomass and improved phytoextraction potential for use in environmental cleanup.

Biophysics and economic potential analysis of vertisols for maize in the humid tropics of Indonesia

NASA Astrophysics Data System (ADS)

Neswati, R.; Lopulisa, C.; Ahmad, A.; Nathan, M.

2018-05-01

The main objective of this study is to establish the potential of Vertisols both biophysical and economic found in the humid relatively dry tropics region in the southern part of Sulawesi to the development of maize. This study used a spatial approach for establishing research sites totalling in 3 observations units of soil profile and involved 30 farmers as respondents. Land potential analysis of was conducted using parametric approach while economic analysis using the benefit-cost (B-C) ratio. The results show that the growing period of the study sites was in November to June, or 240 days and classified as climate type E3. The locations potentially moderately suitable or S2s for maize with soil texture as limiting factors in the growing season from November to June. In the growing season from July to October, the locations are not suitable or Nc with limiting factors such as very limited rainfall in the period of crop ripening. Land suitability Index of study site during the growing season from November to June ranged from 52 to 72 with an average productivity of maize obtained by farmers ranged from 4.3 to 5.7 tons of dry grain per hectare. Analysis of B-C ratio indicates that cultivation of maize in the growing period at such study locations are feasible with the value of B-C ratio ranged from 1.8 to 2.5. These results show that Vertisols in the humid tropics of Indonesia are physically and economically potential for maize development.

An approach for using general soil physical condition-root growth relationships to predict seedling growth response to site preparation tillage in loblolly pine plantations

Treesearch

L.A. Morris; K.H. Ludovici; S.J. Torreano; E.A. Carter; M.C. Lincoln; R.E. Will

2006-01-01

Tree seedling root growth rate can be limited by any one of three soil physical factors: mechanical resistance, water potential or soil aeration. All three factors vary with soil water content and, under field conditions, root growth rate will depend on the soil water content as a result of its relationship to each factor. For a specific site, the relationship between...

Temporal and spatial variations in nutrient stoichiometry and regulation of phytoplankton biomass in Hong Kong waters: influence of the Pearl River outflow and sewage inputs.

PubMed

Xu, Jie; Ho, Alvin Y T; Yin, Kedong; Yuan, Xiangcheng; Anderson, Donald M; Lee, Joseph H W; Harrison, Paul J

2008-01-01

In 2001, the Hong Kong government implemented the Harbor Area Treatment Scheme (HATS) under which 70% of the sewage that had been formerly discharged into Victoria Harbor is now collected and sent to Stonecutters Island Sewage Works where it receives chemically enhanced primary treatment (CEPT), and is then discharged into waters west of the Harbor. The relocation of the sewage discharge will possibly change the nutrient dynamics and phytoplankton biomass in this area. Therefore, there is a need to examine the factors that regulate phytoplankton growth in Hong Kong waters in order to understand future impacts. Based on a historic nutrient data set (1986-2001), a comparison of ambient nutrient ratios with the Redfield ratio (N:P:Si=16:1:16) showed clear spatial variations in the factors that regulate phytoplankton biomass along a west (estuary) to east (coastal/oceanic) transect through Hong Kong waters. Algal biomass was constrained by a combination of low light conditions, a rapid change in salinity, and strong turbulent mixing in western waters throughout the year. Potential stoichiometric Si limitation (up to 94% of the cases in winter) occurred in Victoria Harbor due to the contribution of sewage effluent with high N and P enrichment all year, except for summer when the frequency of stoichiometric Si limitation (48%) was the same as P, owing to the influence of the high Si in the Pearl River discharge. In the eastern waters, potential N limitation and N and P co-limitation occurred in autumn and winter respectively, because of the dominance of coastal/oceanic water with low nutrients and low N:P ratios. In contrast, potential Si limitation occurred in spring and a switch to potential N, P and Si limitation occurred in eastern waters in summer. In southern waters, there was a shift from P limitation (80%) in summer due to the influence of the N-rich Pearl River discharge, to N limitation (68%) in autumn, and to N and P co-limitation in winter due to the dominance of N-poor oceanic water from the oligotrophic South China Sea. Our results show clear temporal and spatial variations in the nutrient stoichiometry which indicates potential regulation of phytoplankton biomass in HK waters due to the combination of the seasonal exchange of the Pearl River discharge and oceanic water, sewage effluent inputs, and strong hydrodynamic mixing from SW monsoon winds in summer and the NE monsoon winds in winter.

Temporal and Spatial Variations in Nutrient Stoichiometry and Regulation of Phytoplankton Biomass in Hong Kong waters: Influence of the Pearl River Outflow and Sewage Inputs

PubMed Central

Xu, Jie; Ho, Alvin Y. T.; Yin, Kedong; Yuan, Xiangcheng; Anderson, Donald M.; Lee, Joseph H.W.; Harrison, Paul J.

2017-01-01

In 2001, the Hong Kong government implemented the Harbor Area Treatment Scheme (HATS) under which 70% of the sewage that had been formerly discharged into Victoria Harbor is now collected and sent to Stonecutters Island Sewage Works where it receives chemically enhanced primary treatment (CEPT), and is then discharged into waters west of the Harbor. The relocation of the sewage discharge will possibly change the nutrient dynamics and phytoplankton biomass in this area. Therefore, there is a need to examine the factors that regulate phytoplankton growth in Hong Kong waters in order to understand future impacts. Based on a historic nutrient data set (1986–2001), a comparison of ambient nutrient ratios with the Redfield ratio (N:P:Si=16:1:16) showed clear spatial variations in the factors that regulate phytoplankton biomass along a west (estuary) to east (coastal/oceanic) transect through Hong Kong waters. Algal biomass was constrained by a combination of low light conditions, a rapid change in salinity, and strong turbulent mixing in western waters throughout the year. Potential stoichiometric Si limitation (up to 94% of the cases in winter) occurred in Victoria Harbor due to the contribution of sewage effluent with high N and P enrichment all year, except for summer when the frequency of stoichiometric Si limitation (48%) was the same as P, owing to the influence of the high Si in the Pearl River discharge. In the eastern waters, potential N limitation and N and P co-limitation occurred in autumn and winter respectively, because of the dominance of coastal/oceanic water with low nutrients and low N:P ratios. In contrast, potential Si limitation occurred in spring and a switch to potential N, P and Si limitation occurred in eastern waters in summer. In southern waters, there was a shift from P limitation (80%) in summer due to the influence of the N-rich Pearl River discharge, to N limitation (68%) in autumn, and to N and P co-limitation in winter due to the dominance of N-poor oceanic water from the oligotrophic South China Sea. Our results show clear temporal and spatial variations in the nutrient stoichiometry which indicates potential regulation of phytoplankton biomass in HK waters due to the combination of the seasonal exchange of the Pearl River discharge and oceanic water, sewage effluent inputs, and strong hydrodynamic mixing from SW monsoon winds in summer and the NE monsoon winds in winter. PMID:18313698

What can we learn from the existing evidence of the business case for investments in nursing care: importance of content, context, and policy environment.

PubMed

Yakusheva, Olga; Wholey, Douglas; Frick, Kevin D

2013-04-01

Decisions of health care institutions to invest in nursing care are often guided by mixed and conflicting evidence of effects of the investments on organizational function and sustainability. This paper uses new evidence generated through Interdisciplinary Nursing Quality Research Initiative (INQRI)-funded research and published in peer-reviewed journals, to illustrate where the business case for nursing investments stands and to discuss factors that may limit the existing evidence and its transferability into clinical practice. We conclude that there are 3 limiting factors: (1) the existing business case for nursing investments is likely understated due to the inability of most studies to capture spillover and long-run dynamic effects, thus causing organizations to forfeit potentially viable nursing investments that may improve long-term financial stability; (2) studies rarely devote sufficient attention to describing the content and the organization-specific contextual factors, thus limiting generalizability; and (3) fragmentation of the current health care delivery and payment systems often leads to the financial benefits of investments in nursing care accruing outside of the organization incurring the costs, thus making potentially quality-improving and cost-saving interventions financially unattractive from the organization's perspective. The payment reform, with its emphasis on high-quality affordable patient-centered care, is likely to strengthen the business case for investments in nursing care. Methodologically rigorous approaches that focus on broader societal implications of investments in nursing care, combined with a thorough understanding of potential barriers and facilitators of nursing change, should be an integral part of future research and policy efforts.

Climate limits across space and time on European forest structure

NASA Astrophysics Data System (ADS)

Moreno, A. L. S.; Neumann, M.; Hasenauer, H.

2017-12-01

The impact climate has on forests has been extensively studied. However, the large scale effect climate has on forest structures, such as average diameters, heights and basal area are understudied in a spatially explicit manner. The limits, tipping points and thresholds that climate places on forest structures dictate the services a forest may provide, the vulnerability of a forest to mortality and the potential value of the timber there within. The majority of current research either investigates climate impacts on forest pools and fluxes, on a tree physiological scale or on case studies that are used to extrapolate results and potential impacts. A spatially explicit study on how climate affects forest structure over a large region would give valuable information to stakeholders who are more concerned with ecosystem services that cannot be described by pools and fluxes but require spatially explicit information - such as biodiversity, habitat suitability, and market values. In this study, we quantified the limits that climate (maximum, minimum temperature and precipitation) places on 3 forest structures, diameter at breast height, height, and basal area throughout Europe. Our results show clear climatic zones of high and low upper limits for each forest structure variable studied. We also spatially analyzed how climate restricts the potential bio-physical upper limits and creates tipping points of each forest structure variable and which climate factors are most limiting. Further, we demonstrated how the climate change has affected 8 individual forests across Europe and then the continent as a whole. We find that diameter, height and basal area are limited by climate in different ways and that areas may have high upper limits in one structure and low upper limits in another limitted by different climate variables. We also found that even though individual forests may have increased their potential upper limit forest structure values, European forests as a whole have lost, on average, 5.0%, 1.7% and 6.5% in potential mean forest diameter, height and basal area, respectively.

Determining the potential productivity of food crops in controlled environments

NASA Technical Reports Server (NTRS)

Bugbee, Bruce

1992-01-01

The quest to determine the maximum potential productivity of food crops is greatly benefitted by crop growth models. Many models have been developed to analyze and predict crop growth in the field, but it is difficult to predict biological responses to stress conditions. Crop growth models for the optimal environments of a Controlled Environment Life Support System (CELSS) can be highly predictive. This paper discusses the application of a crop growth model to CELSS; the model is used to evaluate factors limiting growth. The model separately evaluates the following four physiological processes: absorption of PPF by photosynthetic tissue, carbon fixation (photosynthesis), carbon use (respiration), and carbon partitioning (harvest index). These constituent processes determine potentially achievable productivity. An analysis of each process suggests that low harvest index is the factor most limiting to yield. PPF absorption by plant canopies and respiration efficiency are also of major importance. Research concerning productivity in a CELSS should emphasize: (1) the development of gas exchange techniques to continuously monitor plant growth rates and (2) environmental techniques to reduce plant height in communities.

Tokamak Operation with Safety Factor q 95 < 2 via Control of MHD Stability

DOE PAGES

Piovesan, Paolo; Hanson, Jeremy M.; Martin, Piero; ...

2014-07-24

Magnetic feedback control of the resistive-wall mode has enabled DIII-D to access stable operation at safety factor q95 = 1:9 in divertor plasmas for 150 instability growth times. Magnetohydrodynamic stability sets a hard, disruptive limit on the minimum edge safety factor achievable in a tokamak, or on the maximum plasma current at given toroidal magnetic eld. In tokamaks with a divertor, the limit occurs at q95 = 2, as con rmed in DIII-D. Since the energy con cement time scales linearly with current, this also bounds the performance of a fusion reactor. DIII-D has overcome this limit, opening a wholemore » new high-current regime not accessible before. This result brings signi cant possible bene ts in terms of fusion performance, but it also extends resistive wall mode physics and its control to conditions never explored before. In present experiments, q95 < 2 operation is eventually halted by voltage limits reached in the feedback power supplies, not by intrinsic physics issues. Improvements to power supplies and to control algorithms have the potential to further extend this regime.« less

What limits the use of crop wild relatives for crop improvement? Contrasting case studies (Zea mays and Helianthus annuus L.) provide clues to identify and overcome limiting factors

USDA-ARS?s Scientific Manuscript database

The vast genetic potential present in crop wild relatives (CWR) is often difficult to tap, as identification and transfer of superior alleles into breeding pools to create new crop cultivars is challenging. Conservation of CWR has always been predicated on the promise of new and useful traits, and t...

Biological risk factors for suicidal behaviors: a meta-analysis

PubMed Central

Chang, B P; Franklin, J C; Ribeiro, J D; Fox, K R; Bentley, K H; Kleiman, E M; Nock, M K

2016-01-01

Prior studies have proposed a wide range of potential biological risk factors for future suicidal behaviors. Although strong evidence exists for biological correlates of suicidal behaviors, it remains unclear if these correlates are also risk factors for suicidal behaviors. We performed a meta-analysis to integrate the existing literature on biological risk factors for suicidal behaviors and to determine their statistical significance. We conducted a systematic search of PubMed, PsycInfo and Google Scholar for studies that used a biological factor to predict either suicide attempt or death by suicide. Inclusion criteria included studies with at least one longitudinal analysis using a biological factor to predict either of these outcomes in any population through 2015. From an initial screen of 2541 studies we identified 94 cases. Random effects models were used for both meta-analyses and meta-regression. The combined effect of biological factors produced statistically significant but relatively weak prediction of suicide attempts (weighted mean odds ratio (wOR)=1.41; CI: 1.09–1.81) and suicide death (wOR=1.28; CI: 1.13–1.45). After accounting for publication bias, prediction was nonsignificant for both suicide attempts and suicide death. Only two factors remained significant after accounting for publication bias—cytokines (wOR=2.87; CI: 1.40–5.93) and low levels of fish oil nutrients (wOR=1.09; CI: 1.01–1.19). Our meta-analysis revealed that currently known biological factors are weak predictors of future suicidal behaviors. This conclusion should be interpreted within the context of the limitations of the existing literature, including long follow-up intervals and a lack of tests of interactions with other risk factors. Future studies addressing these limitations may more effectively test for potential biological risk factors. PMID:27622931

Changes in a temperate estuary during the filling of the biggest European dam.

PubMed

Morais, Pedro; Chícharo, Maria Alexandra; Chícharo, Luís

2009-03-15

This study aimed to determine whether and how the disruption of river flow, during the filling of the Alqueva dam, influenced the variability of abiotic and biotic factors in the Guadiana estuary, particularly the abundance and distribution of anchovy eggs. River inflow was found to be the most important factor in determining abiotic and biotic variability in the Guadiana estuary. Seasonal patterns were obscured by long periods of low inflow (mid April to early December 2002), which caused marked changes in the estuary. The estuarine turbidity maximum zone was displaced towards the upper estuary, to at least 38 km from the river mouth, 8 to 16 km upstream from previous records. The dynamics of nutrient stoichiometry was also affected. In the upper and middle estuary, P was more potential limiting than N and potential Si limitation was only frequent on the coast, with direct and/or indirect influence in changing phytoplankton dynamics and composition. Previously, the upper estuary alternated between potential P limitation during winter, Si limitation during spring and mid summer and N limitation during mid summer and autumn. The flooding of vast areas in the catchment of the dam probably caused the increase of DSi concentrations, as well as maximal N and P loadings. The abundance of larval stages of anchovy decreased, putatively because estuarine productivity has also decreased. In April 2002 there was an uncontrolled discharge from the Alqueva dam, which reduced the abundance of anchovy eggs by 99.99%. It is suggested that dam managers should mimic, as much as possible, the natural river flow, in order to minimize the impact on downstream ecosystems. Management efforts should not be restricted to the areas upstream of the dam, but should also encompass the estuary and adjacent coastal area.

Charging of nonspherical macroparticles in a plasma

NASA Astrophysics Data System (ADS)

Holgate, J. T.; Coppins, M.

2016-03-01

The current theories of macroparticle charging in a plasma are limited to spheres, and are unsuitable for the multitude of nonspherical objects existing in astrophysical, atmospheric, laboratory, and fusion plasmas. This paper extends the most widely used spherical charging theory, orbit motion limited theory, to spheroids and, as such, provides a comprehensive study of the charging of nonspherical objects in a plasma. The spherical charging theory is shown to be a reasonable approximation for a considerable range of spheroids. However, the electric potential of highly elongated spheroids can be almost twice the spherical value. Furthermore, the total charge on the spheroids increases by a significantly larger factor than their potential.

Selective mutism: an update and suggestions for future research.

PubMed

Scott, Samantha; Beidel, Deborah C

2011-08-01

Speculation continues regarding the accurate classification of selective mutism and potential etiologic factors. Current research has shed some light on several factors that may predispose some children to this disorder, but conclusions are difficult to draw due to reliance on subjective measures, few comparison groups, and/or limited theoretical grounding. This article provides an update on recent efforts to elucidate the etiologic pathways of selective mutism and on the current debate regarding its strong overlap with anxiety disorders, most notably social phobia. An additional attempt is made to examine findings based on a developmental perspective that accounts for multiple pathways, context, and the developmental stage of the child. Emotion regulation theory is offered as a potential factor in why some children may be more vulnerable to the etiologic factors described. Suggestions for future research are offered based on this integration of information.

Bias-correction of PERSIANN-CDR Extreme Precipitation Estimates Over the United States

NASA Astrophysics Data System (ADS)

Faridzad, M.; Yang, T.; Hsu, K. L.; Sorooshian, S.

2017-12-01

Ground-based precipitation measurements can be sparse or even nonexistent over remote regions which make it difficult for extreme event analysis. PERSIANN-CDR (CDR), with 30+ years of daily rainfall information, provides an opportunity to study precipitation for regions where ground measurements are limited. In this study, the use of CDR annual extreme precipitation for frequency analysis of extreme events over limited/ungauged basins is explored. The adjustment of CDR is implemented in two steps: (1) Calculated CDR bias correction factor at limited gauge locations based on the linear regression analysis of gauge and CDR annual maxima precipitation; and (2) Extend the bias correction factor to the locations where gauges are not available. The correction factors are estimated at gauge sites over various catchments, elevation zones, and climate regions and the results were generalized to ungauged sites based on regional and climatic similarity. Case studies were conducted on 20 basins with diverse climate and altitudes in the Eastern and Western US. Cross-validation reveals that the bias correction factors estimated on limited calibration data can be extended to regions with similar characteristics. The adjusted CDR estimates also outperform gauge interpolation on validation sites consistently. It is suggested that the CDR with bias adjustment has a potential for study frequency analysis of extreme events, especially for regions with limited gauge observations.

Review: Balancing Limiting Factors and Economic Drivers to Achieve Sustainable Midwestern US Agricultural Residue Feedstock Supplies

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

Wally W. Wilhelm; J. Richard Hess; Douglas L. Karlen

2010-10-01

Advanced biofuels will be developed using cellulosic feedstock rather than grain or oilseed crops that can also be used for food and feed. To be sustainable, these new agronomic production systems must be economically viable without degrading soil resources. This review examines six agronomic factors that collectively define many of the limits and opportunities for harvesting crop residue for biofuel feedstock. These six “limiting factors” are discussed in relationship to economic drivers associated with harvesting corn (Zea mays L.) stover as a potential cellulosic feedstock. The limiting factors include soil organic carbon, wind and water erosion, plant nutrient balance, soilmore » water and temperature dynamics, soil compaction, and off-site environmental impacts. Initial evaluations using the Revised Universal Soil Loss Equation 2.0 (RUSLE2) show that a single factor analysis based on simply meeting tolerable soil loss might indicate stover could be harvested sustainably, but the same analysis based on maintaining soil organic carbon shows the practice to be non-sustainable. Modifying agricultural management to include either annual or perennial cover crops is shown to meet both soil erosion and soil carbon requirements. The importance of achieving high yields and planning in a holistic manner at the landscape scale are also shown to be crucial for balancing limitations and drivers associated with renewable bioenergy production.« less

Mannitol-Enhanced Delivery of Stem Cells and Their Growth Factors Across the Blood–Brain Barrier

PubMed Central

Gonzales-Portillo, Gabriel S.; Sanberg, Paul R.; Franzblau, Max; Gonzales-Portillo, Chiara; Diamandis, Theo; Staples, Meaghan; Sanberg, Cyndy D.; Borlongan, Cesar V.

2014-01-01

Ischemic brain injury in adults and neonates is a significant clinical problem with limited therapeutic interventions. Currently, clinicians have only tPA available for stroke treatment and hypothermia for cerebral palsy. Owing to the lack of treatment options, there is a need for novel treatments such as stem cell therapy. Various stem cells including cells from embryo, fetus, perinatal, and adult tissues have proved effective in preclinical and small clinical trials. However, a limiting factor in the success of these treatments is the delivery of the cells and their by-products (neurotrophic factors) into the injured brain. We have demonstrated that mannitol, a drug with the potential to transiently open the blood–brain barrier and facilitate the entry of stem cells and trophic factors, as a solution to the delivery problem. The combination of stem cell therapy and mannitol may improve therapeutic outcomes in adult stroke and neonatal cerebral palsy. PMID:24480552

Derivation of safe health-based exposure limits for potential consumer exposure to styrene migrating into food from food containers.

PubMed

Gelbke, Heinz-Peter; Banton, Marcy; Faes, Eric; Leibold, Edgar; Pemberton, Mark; Duhayon, Sophie

2014-02-01

Residual styrene present in polystyrene food packaging may migrate into food at low levels. To assure safe use, safe exposure levels are derived for consumers potentially exposed via food using No/Low Adverse Effect Levels from animal and human studies and assessment factors proposed by European organisations (EFSA, ECHA, ECETOC). Ototoxicity and developmental toxicity in rats and human ototoxicity and effects on colour discrimination have been identified as the most relevant toxicological properties for styrene health assessments. Safe exposure levels derived from animal studies with assessment factors of EFSA and ECHA were expectedly much lower than those using the ECETOC approach. Comparable safe exposure levels were obtained from human data with all sets of assessment factors while ototoxicity in rats led to major differences. The safe exposure levels finally selected based on criteria of science and health protection converged to the range of 90-120 mg/person/d. Assuming a consumption of 1 kg food/d for an adult, this translates to 90 mg styrene migration into 1 kg food as safe for consumers. This assessment supports a health based Specific Migration Limit of 90 ppm, a value somewhat higher than the current overall migration limit of 60 ppm in the European Union. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Factors associated with physical activity promotion by allied and other non-medical health professionals: A systematic review.

PubMed

Crisford, Paul; Winzenberg, Tania; Venn, Alison; Schultz, Martin; Aitken, Dawn; Cleland, Verity

2018-05-21

To identify factors associated with non-medical health professionals' engagement in physical activity (PA) promotion. Five electronic databases were searched for studies including practising health professionals (excluding medical doctors), a PA promotion practice measure, a test of association between potential influencing factors and PA promotion practice, and written in English. Two researchers independently screened studies and extracted data. Extracted data were synthesized in a tabular format with a narrative summary (thematic analysis). Thirty studies involving 7734 non-medical health professionals were included. Self-efficacy in PA promotion, positive beliefs in the benefits of PA, assessing patients' PA, and PA promotion training were the main factors associated with engaging in PA promotion. Lack of remuneration was not associated. Common study limitations included a lack of information on non-responders, data collection by survey only and limited reliability or validity testing of measurements. There are common factors influencing PA promotion, but the absence of studies from some health professions, limitations related to study measures, and the lack of randomised controlled intervention trials highlights the need for further research. The factors identified may prove useful for guiding the development of strategies to encourage greater engagement in PA promotion by health professionals. Copyright © 2018 Elsevier B.V. All rights reserved.

Risk factors associated with persistent airflow limitation in severe or difficult-to-treat asthma: insights from the TENOR study.

PubMed

Lee, June H; Haselkorn, Tmirah; Borish, Larry; Rasouliyan, Lawrence; Chipps, Bradley E; Wenzel, Sally E

2007-12-01

The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study is among the largest to assess persistent airflow limitation and the first to evaluate a wide range of potential risk factors in high-risk patients with severe or difficult-to-treat asthma. A better understanding is needed regarding factors associated with persistent airway obstruction; this study was performed to determine demographic and clinical characteristics associated with persistent airflow limitation. Data from adult patients (>or= 18 years old) with severe or difficult-to-treat asthma were evaluated. Patients with COPD, obesity with a restrictive respiratory pattern, or a >or= 30 pack-year history of smoking were excluded. Patients with persistent airflow limitation (postbronchodilator FEV1/FVC ratio

Factors affecting the extent of utilization of physiotherapy services by physicians in Saudi Arabia

PubMed Central

Alshehri, Mansour Abdullah; Alhasan, Hammad; Alayat, Mohamed; Al-subahi, Moayad; Yaseen, Khalid; Ismail, Ayah; Tobaigy, Abdullah; Almalki, Obaid; Alqahtani, Abdulfattah; Fallata, Basmah

2018-01-01

[Purpose] To investigate physicians’ attitudes, opinions and experiences towards physiotherapy services as well as to identify the potential factors that may affect the extent of utilization of physiotherapy services (based on physicians’ beliefs) in Saudi Arabia (SA). [Subjects and Methods] A cross-sectional study was conducted. [Results] A total of 108 respondents met the inclusion criteria. The respondents’ attitude towards physiotherapy was slightly low (53.5%), while their opinions and experiences of physiotherapy indicated some important issues. For example, 50% of them believed that physiotherapists did not create a good awareness about physiotherapy services and 55.5% admitted that they did not have enough information about physiotherapy services. The most potential factor reported by physicians that may affect the extent of utilization of physiotherapy services was the lack of physiotherapist’s skills and knowledge to assess and treat patients (55.3%), followed by the limited knowledge of physicians regarding the types of physiotherapy services (44.5%) and the lack of cooperation between physicians and physiotherapists (40.7%). [Conclusion] There were some factors that limited the extent of utilization of physiotherapy services in SA. Physiotherapy academics and clinicians should attempt to change physicians’ negative attitudes, promoting awareness to provide them with a better understanding of physiotherapy services. PMID:29545681

Assessment of water resource potential for common use of cow and goat by GIS (Case study: Boroujerd Rangeland, Sarab Sefid, Iran)

NASA Astrophysics Data System (ADS)

Ariapour, A.; Karami, K.; Sadr, A.

2014-06-01

One of the most important factors to sustainability utilization of natural potential by rangeland grazing suitability is water resources suitability. This study is a model for quantitative, qualitative and spatial distance assessment of water resource's propriety for goat and cow grazing based on geographic information systems (GIS) in Boroujerd Sarab Sefid rangeland, Lorestan province, Iran 2013. In this research from combining three factors such as quantity, quality and water resource's distances; the final model of degree of propriety of water resources for goat and cow grazing is characterized. Results showed that slope factor was the reason of limitation, and it is considered as a limiting factor in propriety of water resources, so in terms of access to water resources for goat grazing, 4856.4 ha (100%) located in S1 classes and for cow grazing, 4023.14 ha (68.6%) located in S1(suitability) classes, 1,187 ha (20.24%) in S2 classes and 654.8 ha (11.16%) located in S3 classes, respectively for both. So according to the results the rangelands in this region are most suitable for goat because of terrain and weather but this, in combination with, cow hasbandry will allow diversity of economic production and stability of incomes.

The Role of Education in Preventing Nuclear War.

ERIC Educational Resources Information Center

Markusen, Eric; Harris, John B.

1984-01-01

Examines the role of education in the Holocaust of Nazi Germany, discusses U.S. nuclear weapons policy and factors of psychological resistance that have limited citizen participation in decision making, and explores the potential of education to help prevent nuclear war. (Author/SK)

The Family Struggles of Sisters Makin' Music.

ERIC Educational Resources Information Center

Nurullah, Shanta

1979-01-01

In assessing how relationships with parents, husbands, male musicians, and society at large can work to limit a Black woman's musical expression, it is possible that the most crucial factor in whether her musical potential is nurtured or negated is the family. (Author/WI)

Risk and Resilience Factors Related to Parental Bereavement Following the Death of a Child with a Life-Limiting Condition

PubMed Central

Jaaniste, Tiina; Coombs, Sandra; Donnelly, Theresa J.; Kelk, Norm; Beston, Danielle

2017-01-01

This paper reviews the theoretical and empirical literature on risk and resilience factors impacting on parental bereavement outcomes following the death of a child with a life-limiting condition. Over the past few decades, bereavement research has focussed primarily on a risk-based approach. In light of advances in the literature on resilience, the authors propose a Risk and Resilience Model of Parental Bereavement, thus endeavouring to give more holistic consideration to a range of potential influences on parental bereavement outcomes. The literature will be reviewed with regard to the role of: (i) loss-oriented stressors (e.g., circumstances surrounding the death and multiple losses); (ii) inter-personal factors (e.g., marital factors, social support, and religious practices); (iii) intra-personal factors (e.g., neuroticism, trait optimism, psychological flexibility, attachment style, and gender); and (iv) coping and appraisal, on parental bereavement outcomes. Challenges facing this area of research are discussed, and research and clinical implications considered. PMID:29120367

Yield Potential of Sugar Beet – Have We Hit the Ceiling?

PubMed Central

Hoffmann, Christa M.; Kenter, Christine

2018-01-01

The yield of sugar beet has continuously increased in the past decades. The question arises, whether this progress will continue in the future. A key factor for increasing yield potential of the crop is breeding progress. It was related to a shift in assimilate partitioning in the plant toward more storage carbohydrates (sucrose), whereas structural carbohydrates (leaves, cell wall compounds) unintendedly declined. The yield potential of sugar beet was estimated at 24 t sugar ha-1. For maximum yield, sufficient growth factors have to be available and the crop has to be able to fully utilize them. In sugar beet, limitations result from the lacking coincidence of maximum irradiation rates and full canopy cover, sink strength for carbon assimilation and high water demand, which cannot be met by rainfall alone. After harvest, sugar losses during storage occur. The paper discusses options for a further increase in yield potential, like autumn sowing of sugar beet, increasing sink strength and related constraints. It is prospected that yield increase by further widening the ratio of storage and structural carbohydrates will come to its natural limit as a certain cell wall stability is necessary. New challenges caused by climate change and by prolonged processing campaigns will occur. Thus breeding for improved pathogen resistance and storage properties will be even more important for successful sugar beet production than a further increase in yield potential itself. PMID:29599787

Geographic variability in elevation and topographic constraints on the distribution of native and nonnative trout in the Great Basin

USGS Publications Warehouse

Warren, Dana R.; Dunham, Jason B.; Hockman-Wert, David

2014-01-01

Understanding local and geographic factors influencing species distributions is a prerequisite for conservation planning. Our objective in this study was to model local and geographic variability in elevations occupied by native and nonnative trout in the northwestern Great Basin, USA. To this end, we analyzed a large existing data set of trout presence (5,156 observations) to evaluate two fundamental factors influencing occupied elevations: climate-related gradients in geography and local constraints imposed by topography. We applied quantile regression to model upstream and downstream distribution elevation limits for each trout species commonly found in the region (two native and two nonnative species). With these models in hand, we simulated an upstream shift in elevation limits of trout distributions to evaluate potential consequences of habitat loss. Downstream elevation limits were inversely associated with latitude, reflecting regional gradients in temperature. Upstream limits were positively related to maximum stream elevation as expected. Downstream elevation limits were constrained topographically by valley bottom elevations in northern streams but not in southern streams, where limits began well above valley bottoms. Elevation limits were similar among species. Upstream shifts in elevation limits for trout would lead to more habitat loss in the north than in the south, a result attributable to differences in topography. Because downstream distributions of trout in the north extend into valley bottoms with reduced topographic relief, trout in more northerly latitudes are more likely to experience habitat loss associated with an upstream shift in lower elevation limits. By applying quantile regression to relatively simple information (species presence, elevation, geography, topography), we were able to identify elevation limits for trout in the Great Basin and explore the effects of potential shifts in these limits that could occur in response to changing climate conditions that alter streams directly (e.g., through changes in temperature and precipitation) or indirectly (e.g., through changing water use).

Beneficial Effect of Post-Deposition Treatment in High-Efficiency Cu(In,Ga)Se2 Solar Cells through Reduced Potential Fluctuations

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

Jensen, Soren A.; Glynn, Stephen; Kanevce, Ana

World-record power conversion efficiencies for Cu(In,Ga)Se2 (CIGS) solar cells have been achieved via a post-deposition treatment with alkaline metals, which increases the open-circuit voltage and fill factor. We explore the role of the potassium fluoride (KF) post-deposition treatment in CIGS by employing energy- and time-resolved photoluminescence spectroscopy and electrical characterization combined with numerical modeling. The bulk carrier lifetime is found to increase with post-deposition treatment from 255 ns to 388 ns, which is the longest charge carrier lifetime reported for CIGS, and within ~40% of the radiative limit. We find evidence that the post-deposition treatment causes a decrease in themore » electronic potential fluctuations. These potential fluctuations have previously been shown to reduce the open-circuit voltage and the device efficiency in CIGS. Additionally, numerical simulations based on the measured carrier lifetimes and mobilities show a diffusion length of ~10 um, which is ~4 times larger than the film thickness. Thus, carrier collection in the bulk is not a limiting factor for device efficiency. By considering differences in doping, bandgap, and potential fluctuations, we present a possible explanation for the voltage difference between KF-treated and untreated samples.« less

Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

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

Naus, Dan J; Mattus, Catherine H; Dole, Leslie Robert

The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a "primer" on factors that can affect the durability of concrete materials andmore » structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a "bench-scale" laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the "primer," a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures.« less

Opportunities for Automated Demand Response in California Wastewater Treatment Facilities

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

Aghajanzadeh, Arian; Wray, Craig; McKane, Aimee

Previous research over a period of six years has identified wastewater treatment facilities as good candidates for demand response (DR), automated demand response (Auto-­DR), and Energy Efficiency (EE) measures. This report summarizes that work, including the characteristics of wastewater treatment facilities, the nature of the wastewater stream, energy used and demand, as well as details of the wastewater treatment process. It also discusses control systems and automated demand response opportunities. Furthermore, this report summarizes the DR potential of three wastewater treatment facilities. In particular, Lawrence Berkeley National Laboratory (LBNL) has collected data at these facilities from control systems, submetered processmore » equipment, utility electricity demand records, and governmental weather stations. The collected data were then used to generate a summary of wastewater power demand, factors affecting that demand, and demand response capabilities. These case studies show that facilities that have implemented energy efficiency measures and that have centralized control systems are well suited to shed or shift electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. In summary, municipal wastewater treatment energy demand in California is large, and energy-­intensive equipment offers significant potential for automated demand response. In particular, large load reductions were achieved by targeting effluent pumps and centrifuges. One of the limiting factors to implementing demand response is the reaction of effluent turbidity to reduced aeration at an earlier stage of the process. Another limiting factor is that cogeneration capabilities of municipal facilities, including existing power purchase agreements and utility receptiveness to purchasing electricity from cogeneration facilities, limit a facility’s potential to participate in other DR activities.« less

Potential factors associated with knee pain in cyclists: a systematic review.

PubMed

Bini, Rodrigo Rico; Flores Bini, Alice

2018-01-01

The potential factors associated with overuse injuries and pain in cyclists that are supported by evidence remain unclear. Our study aimed at assessing, using a systematic search of the most updated evidence, the main factors related to overuse knee-related pain and/or injuries in cyclists. The search assessed any potential mechanism related to knee pain or injury that could be used in the clinical practice. Databases were searched (i.e., PubMed, Scopus, Web of Science, and EBSCO). Studies were included if they presented results from original studies. They had to include, preferably but not limited to, recreational and/or competitive cyclists with or without knee pain. Quality of articles was assessed. Eleven articles were deemed eligible for full text appraisal. Studies involved generally the assessment of biomechanical outcomes associated with knee pain in cyclists. Overall, studies showed that cyclists with knee pain present larger knee adduction and larger ankle dorsiflexion and differences in activation for hamstrings and quadriceps muscles. Unclear results were observed for knee moments and no differences were observed for knee flexion angle, tibiofemoral and patellofemoral forces. It is important to state that varied types of knee pain were mixed in most studies, with 2 focused on anterior-related pain. Cyclists with overuse-related pain or injuries on their knees presented an increased medial projection of their knees and an altered activation of the Vastus Medialis and Vastus Lateralis muscles. However, this limited evidence is based on retrospective studies comparing cyclists with and without pain, which limits the conclusion on how cyclists develop knee pain and what are the main options for treatment of knee pain.

Time-dependent spin-density-functional-theory description of He+-He collisions

NASA Astrophysics Data System (ADS)

Baxter, Matthew; Kirchner, Tom; Engel, Eberhard

2017-09-01

Theoretical total cross-section results for all ionization and capture processes in the He+-He collision system are presented in the approximate impact energy range of 10-1000 keV/amu. Calculations were performed within the framework of time-dependent spin-density functional theory. The Krieger-Li-Iafrate approximation was used to determine an accurate exchange-correlation potential in the exchange-only limit. The results of two models, one where electron translation factors in the orbitals used to calculate the potential are ignored and another where partial electron translation factors are included, are compared with available experimental data as well as a selection of previous theoretical calculations.

Limitations and plausibility of the Pliocene lignite hypothesis in explaining the etiology of Balkan endemic nephropathy

PubMed Central

Maharaj, S V M

2014-01-01

Background: Balkan endemic nephropathy (BEN) is a chronic, tubulointerstitial renal disease often accompanied by urothelial cancer that has a lethality of nearly 100%. Introduction: One of the many factors that have been proposed to play an etiological role in BEN is exposure to organic compounds from Pliocene lignite coal deposits via the drinking water in endemic areas. Objectives: The objective of this study was to systematically evaluate the role of the tenets of the Pliocene lignite hypothesis in the etiology of BEN in order to provide an improved understanding of the hypothesis for colleagues and patients alike. Methods: A comprehensive compilation of the possible limitations of the hypothesis, with each limitation addressed in turn is presented. Results: The Pliocene lignite hypothesis can best account for, is consistent with, or has the potential to explain the evidence associated with the myriad of factors related to BEN. Conclusions: Residents of endemic areas are exposed to complex mixtures containing hundreds of organic compounds at varying doses and their potentially more toxic (including nephrotoxic) and/or carcinogenic metabolites; however, a multifactorial etiology of BEN appears most likely. PMID:24075451

Peculiarities in Ankle Cartilage.

PubMed

Kraeutler, Matthew J; Kaenkumchorn, Tanyaporn; Pascual-Garrido, Cecilia; Wimmer, Markus A; Chubinskaya, Susanna

2017-01-01

Posttraumatic osteoarthritis (PTOA) is the most common form of osteoarthritis (OA) of the ankle joint. PTOA occurs as a result of several factors, including the poor regenerative capacity of hyaline articular cartilage as well as increased contact stresses following trauma. The purpose of this article is to review the epidemiology, pathogenesis, and potential targets for treatment of PTOA in the ankle joint. Previous reviews primarily addressed clinical approaches to ankle PTOA, while the focus of the current article will be specifically on the newly acquired knowledge of the cellular mechanisms that drive PTOA in the ankle joint and means for potential targeted therapeutics that might halt the progression of cartilage degeneration and/or improve the outcome of surgical interventions. Three experimental treatment strategies are discussed in this review: (1) increasing the anabolic potential of chondrocytes through treatment with growth factors such as bone morphogenetic protein-7; (2) limiting chondrocyte cell death either through the protection of cell membrane with poloxamer 188 or inhibiting activity of intracellular proteases, caspases, which are responsible for cell death by apoptosis; and (3) inhibiting catabolic/inflammatory responses of chondrocytes by treating them with anti-inflammatory agents such as tumor necrosis factor-α antagonists. Future studies should focus on identifying the appropriate timing for treatment and an appropriate combination of anti-inflammatory, chondro- and matrix-protective biologics to limit the progression of trauma-induced cartilage degeneration and prevent the development of PTOA in the ankle joint.

Maize yield gaps caused by non-controllable, agronomic, and socioeconomic factors in a changing climate of Northeast China.

PubMed

Liu, Zhijuan; Yang, Xiaoguang; Lin, Xiaomao; Hubbard, Kenneth G; Lv, Shuo; Wang, Jing

2016-01-15

Closing the gap between current and potential yields is one means of increasing agricultural production to feed the globally increasing population. Therefore, investigation of the geographic patterns, trends and causes of crop yield gaps is essential to identifying where yields might be increased and quantifying the contributions of yield-limiting factors that may provide us potentials to enhance crop productivity. In this study, the changes in potential yields, attainable yields, potential farmers' yields, and actual farmers' yields during the past five decades in Northeast China (NEC) were investigated. Additionally the yield gaps caused by non-controllable, agronomic, and socioeconomic factors were determined. Over the period 1961 to 2010 the estimated regional area-weighted mean maize potential yield, attainable yield, and potential farmers' yield were approximately 12.3 t ha(-1), 11.5 t ha(-1), and 6.4 t ha(-1) which showed a decreasing tendency. The actual farmers' yield over NEC was 4.5 t ha(-1), and showed a tendency to increase (p<0.01) by 1.27 t ha(-1) per decade. The regional mean total yield gap (YGt), weighted by the area in each county dedicated to maize crop, was 64% of potential yield. Moreover, 8, 40, and 16% reductions in potential yields were due to non-controllable factors (YGI), agronomic factors (YGII), and socioeconomic factors (YGIII), respectively. Therefore, the exploitable yield gap, considered here as the difference between the potential yield and what one can expect considering non-controllable factors (i.e. YGt-YGI), of maize in NEC was about 56%. The regional area-weighted averages of YGt, and YGIII were found to have significant decreases of 11.0, and 10.7% per decade. At the time horizon 2010, the exploitable yield gaps were estimated to equal 36% of potential yield. This led to the conclusion that the yield gap could be deeply reduced by improving local agronomic management and controlling socioeconomic factors. Copyright © 2015 Elsevier B.V. All rights reserved.

Climate matching as a tool for predicting potential North American spread of Brown Treesnakes

USGS Publications Warehouse

Rodda, Gordon H.; Reed, Robert N.; Jarnevich, Catherine S.; Witmer, G.W.; Pitt, W. C.; Fagerstone, K.A.

2007-01-01

Climate matching identifies extralimital destinations that could be colonized by a potential invasive species on the basis of similarity to climates found in the species’ native range. Climate is a proxy for the factors that determine whether a population will reproduce enough to offset mortality. Previous climate matching models (e.g., Genetic Algorithm for Rule-set Prediction [GARP]) for brown treesnakes (Boiga irregularis) were unsatisfactory, perhaps because the models failed to allow different combinations of climate attributes to influence a species’ range limits in different parts of the range. Therefore, we explored the climate space described by bivariate parameters of native range temperature and rainfall, allowing up to two months of aestivation in the warmer portions of the range, or four months of hibernation in temperate climes. We found colonization area to be minimally sensitive to assumptions regarding hibernation temperature thresholds. Although brown treesnakes appear to be limited by dry weather in the interior of Australia, aridity rarely limits potential distribution in most of the world. Potential colonization area in North America is limited primarily by cold. Climatically suitable portions of the United States (US) mainland include the Central Valley of California, mesic patches in the Southwest, and the southeastern coastal plain from Texas to Virginia.

Finding the Perfect Match: Factors That Influence Family Medicine Residency Selection.

PubMed

Wright, Katherine M; Ryan, Elizabeth R; Gatta, John L; Anderson, Lauren; Clements, Deborah S

2016-04-01

Residency program selection is a significant experience for emerging physicians, yet there is limited information about how applicants narrow their list of potential programs. This study examines factors that influence residency program selection among medical students interested in family medicine at the time of application. Medical students with an expressed interest in family medicine were invited to participate in a 37-item, online survey. Students were asked to rate factors that may impact residency selection on a 6-point Likert scale in addition to three open-ended qualitative questions. Mean values were calculated for each survey item and were used to determine a rank order for selection criteria. Logistic regression analysis was performed to identify factors that predict a strong interest in urban, suburban, and rural residency programs. Logistic regression was also used to identify factors that predict a strong interest in academic health center-based residencies, community-based residencies, and community-based residencies with an academic affiliation. A total of 705 medical students from 32 states across the country completed the survey. Location, work/life balance, and program structure (curriculum, schedule) were rated the most important factors for residency selection. Logistic regression analysis was used to refine our understanding of how each factor relates to specific types of residencies. These findings have implications for how to best advise students in selecting a residency, as well as marketing residencies to the right candidates. Refining the recruitment process will ensure a better fit between applicants and potential programs. Limited recruitment resources may be better utilized by focusing on targeted dissemination strategies.

The search for life on Europa: limiting environmental factors, potential habitats, and Earth analogues.

PubMed

Marion, Giles M; Fritsen, Christian H; Eicken, Hajo; Payne, Meredith C

2003-01-01

The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biological activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pressure, and time; (2) potential habitats for life on Europa; and (3) Earth analogues and their limitations for Europa. Based on empirical evidence, the limits for biological activity on Earth are: (1) the temperature range is from 253 to 394 K; (2) the salinity range is a(H2O) = 0.6-1.0; (3) the desiccation range is from 60% to 100% relative humidity; (4) the acidity range is from pH 0 to 13; (5) microbes such as Deinococcus are roughly 4,000 times more resistant to ionizing radiation than humans; (6) the range for hydrostatic pressure is from 0 to 1,100 bars; and (7) the maximum time for organisms to survive in the dormant state may be as long as 250 million years. The potential habitats for life on Europa are the ice layer, the brine ocean, and the seafloor environment. The dual stresses of lethal radiation and low temperatures on or near the icy surface of Europa preclude the possibility of biological activity anywhere near the surface. Only at the base of the ice layer could one expect to find the suitable temperatures and liquid water that are necessary for life. An ice layer turnover time of 10 million years is probably rapid enough for preserving in the surface ice layers dormant life forms originating from the ocean. Model simulations demonstrate that hypothetical oceans could exist on Europa that are too cold for biological activity (T < 253 K). These simulations also demonstrate that salinities are high, which would restrict life to extreme halophiles. An acidic ocean (if present) could also potentially limit life. Pressure, per se, is unlikely to directly limit life on Europa. But indirectly, pressure plays an important role in controlling the chemical environments for life. Deep ocean basins such as the Mariana Trench are good analogues for the cold, high-pressure ocean of Europa. Many of the best terrestrial analogues for potential Europan habitats are in the Arctic and Antarctica. The six factors likely to be most important in defining the environments for life on Europa and the focus for future work are liquid water, energy, nutrients, low temperatures, salinity, and high pressures.

DNA Methylation: An Epigenetic Risk Factor in Preterm Birth

PubMed Central

Menon, Ramkumar; Conneely, Karen N.; Smith, Alicia K.

2012-01-01

Spontaneous preterm birth (PTB; birth prior to 37 weeks of gestation) is a complex phenotype with multiple risk factors that complicate our understanding of its etiology. A number of recent studies have supported the hypothesis that epigenetic modifications such as DNA methylation induced by pregnancy-related risk factors may influence the risk of PTB or result in changes that predispose a neonate to adult-onset diseases. The critical role of timing of gene expression in the etiology of PTB makes it a highly relevant disorder in which to examine the potential role of epigenetic changes. Because changes in DNA methylation patterns can result in long-term consequences, it is of critical interest to identify the epigenetic patterns associated with adverse pregnancy outcomes. This review examines the potential role of DNA methylation as a risk factor for PTB and discusses several issues and limitations that should be considered when planning DNA methylation studies. PMID:22228737

Geographical Detector-Based Risk Assessment of the Under-Five Mortality in the 2008 Wenchuan Earthquake, China

PubMed Central

Hu, Yi; Wang, Jinfeng; Li, Xiaohong; Ren, Dan; Zhu, Jun

2011-01-01

On 12 May, 2008, a devastating earthquake registering 8.0 on the Richter scale occurred in Sichuan Province, China, taking tens of thousands of lives and destroying the homes of millions of people. Many of the deceased were children, particular children less than five years old who were more vulnerable to such a huge disaster than the adult. In order to obtain information specifically relevant to further researches and future preventive measures, potential risk factors associated with earthquake-related child mortality need to be identified. We used four geographical detectors (risk detector, factor detector, ecological detector, and interaction detector) based on spatial variation analysis of some potential factors to assess their effects on the under-five mortality. It was found that three factors are responsible for child mortality: earthquake intensity, collapsed house, and slope. The study, despite some limitations, has important implications for both researchers and policy makers. PMID:21738660

Geographical detector-based risk assessment of the under-five mortality in the 2008 Wenchuan earthquake, China.

PubMed

Hu, Yi; Wang, Jinfeng; Li, Xiaohong; Ren, Dan; Zhu, Jun

2011-01-01

On 12 May, 2008, a devastating earthquake registering 8.0 on the Richter scale occurred in Sichuan Province, China, taking tens of thousands of lives and destroying the homes of millions of people. Many of the deceased were children, particular children less than five years old who were more vulnerable to such a huge disaster than the adult. In order to obtain information specifically relevant to further researches and future preventive measures, potential risk factors associated with earthquake-related child mortality need to be identified. We used four geographical detectors (risk detector, factor detector, ecological detector, and interaction detector) based on spatial variation analysis of some potential factors to assess their effects on the under-five mortality. It was found that three factors are responsible for child mortality: earthquake intensity, collapsed house, and slope. The study, despite some limitations, has important implications for both researchers and policy makers.

Application of discriminant analysis-based model for prediction of risk of low back disorders due to workplace design in industrial jobs.

PubMed

Ganga, G M D; Esposto, K F; Braatz, D

2012-01-01

The occupational exposure limits of different risk factors for development of low back disorders (LBDs) have not yet been established. One of the main problems in setting such guidelines is the limited understanding of how different risk factors for LBDs interact in causing injury, since the nature and mechanism of these disorders are relatively unknown phenomena. Industrial ergonomists' role becomes further complicated because the potential risk factors that may contribute towards the onset of LBDs interact in a complex manner, which makes it difficult to discriminate in detail among the jobs that place workers at high or low risk of LBDs. The purpose of this paper was to develop a comparative study between predictions based on the neural network-based model proposed by Zurada, Karwowski & Marras (1997) and a linear discriminant analysis model, for making predictions about industrial jobs according to their potential risk of low back disorders due to workplace design. The results obtained through applying the discriminant analysis-based model proved that it is as effective as the neural network-based model. Moreover, the discriminant analysis-based model proved to be more advantageous regarding cost and time savings for future data gathering.

A vectorial capacity product to monitor changing malaria transmission potential in epidemic regions of Africa

USGS Publications Warehouse

Ceccato, Pietro; Vancutsem, Christelle; Klaver, Robert; Rowland, James; Connor, Stephen J.

2012-01-01

Rainfall and temperature are two of the major factors triggering malaria epidemics in warm semi-arid (desert-fringe) and high altitude (highland-fringe) epidemic risk areas. The ability of the mosquitoes to transmit Plasmodium spp. is dependent upon a series of biological features generally referred to as vectorial capacity. In this study, the vectorial capacity model (VCAP) was expanded to include the influence of rainfall and temperature variables on malaria transmission potential. Data from two remote sensing products were used to monitor rainfall and temperature and were integrated into the VCAP model. The expanded model was tested in Eritrea and Madagascar to check the viability of the approach. The analysis of VCAP in relation to rainfall, temperature and malaria incidence data in these regions shows that the expanded VCAP correctly tracks the risk of malaria both in regions where rainfall is the limiting factor and in regions where temperature is the limiting factor. The VCAP maps are currently offered as an experimental resource for testing within Malaria Early Warning applications in epidemic prone regions of sub-Saharan Africa. User feedback is currently being collected in preparation for further evaluation and refinement of the VCAP model.

The ecology of microorganisms in a small closed system: Potential benefits and problems for space station

NASA Technical Reports Server (NTRS)

Rodgers, E. B.

1986-01-01

The inevitble presence on the space station of microorganisms associated with crew members and their environment will have the potential for both benefits and a range of problems including illness and corrosion of materials. This report reviews the literature presenting information about microorganisms pertinent to Environmental Control and Life Support (ECLS) on the space station. The perspective of the report is ecological, viewing the space station as an ecosystem in which biological relationships are affected by factors such as zero gravity and by closure of a small volume of space. Potential sites and activities of microorganisms on the space station and their environmental limits, microbial standards for the space station, monitoring and control methods, effects of space factors on microorganisms, and extraterrestrial contamination are discussed.

Identifying factors for optimal development of health-related websites: a delphi study among experts and potential future users.

PubMed

Schneider, Francine; van Osch, Liesbeth; de Vries, Hein

2012-02-14

The Internet has become a popular medium for offering tailored and targeted health promotion programs to the general public. However, suboptimal levels of program use in the target population limit the public health impact of these programs. Optimizing program development is considered as one of the main processes to increase usage rates. To distinguish factors potentially related to optimal development of health-related websites by involving both experts and potential users. By considering and incorporating the opinions of experts and potential users in the development process, involvement in the program is expected to increase, consequently resulting in increased appreciation, lower levels of attrition, and higher levels of sustained use. We conducted a systematic three-round Delphi study through the Internet. Both national and international experts (from the fields of health promotion, health psychology, e-communication, and technical Web design) and potential users were invited via email to participate. During this study an extensive list of factors potentially related to optimal development of health-related websites was identified, by focusing on factors related to layout, general and risk information provision, questionnaire use, additional services, and ease of use. Furthermore, we assessed the extent to which experts and potential users agreed on the importance of these factors. Differences as well as similarities among experts and potentials users were deduced. In total, 20 of 62 contacted experts participated in the first round (32% response rate); 60 of 200 contacted experts (30% response rate) and 210 potential users (95% response rate) completed the second-round questionnaire, and 32 of 60 contacted experts completed the third round (53% response rate). Results revealed important factors consented upon by experts and potential users (eg, ease of use, clear structure, and detailed health information provision), as well as differences regarding important factors consented upon by experts (eg, visual aids, self-monitoring tool, and iterative health feedback) or by potential users only (eg, bread crumb navigation and prevention of receiving spam). This study is an important first step in determining the agreed-upon factors that should be taken into account when developing online health promotion programs. The public health impact of these programs will be improved by optimizing the development process in line with these factors.

Lung magnetic resonance imaging for pneumonia in children.

PubMed

Liszewski, Mark C; Görkem, Süreyya; Sodhi, Kushaljit S; Lee, Edward Y

2017-10-01

Technical factors have historically limited the role of MRI in the evaluation of pneumonia in children in routine clinical practice. As imaging technology has advanced, recent studies utilizing practical MR imaging protocols have shown MRI to be an accurate potential alternative to CT for the evaluation of pneumonia and its complications. This article provides up-to-date MR imaging techniques that can be implemented in most radiology departments to evaluate pneumonia in children. Imaging findings in pneumonia on MRI are also reviewed. In addition, the current literature describing the diagnostic performance of MRI for pneumonia is discussed. Furthermore, potential risks and limitations of MRI for the evaluation of pneumonia in children are described.

Planning and the Energy-Water Nexus

NASA Astrophysics Data System (ADS)

Tidwell, V. C.; Bailey, M.; Zemlick, K.; Moreland, B.

2015-12-01

While thermoelectric power generation accounts for only 3-5% of the nation's consumptive use of freshwater, its future potential to exert pressure on limited water supplies is of concern given projected growth in electric power generation. The corresponding thermoelectric water footprint could look significantly different depending on decisions concerning the mix of fuel type, cooling type, location, and capacity, which are influenced by such factors as fuel costs, technology evolution, demand growth, policies, and climate change. The complex interplay among these disparate factors makes it difficult to identify where water could limit siting choices for thermoelectric generation or alternatively, thermoelectric development could limit growth in other water use sectors. These arguments point to the need for joint coordination, analysis and planning between energy and water managers. Here we report on results from a variety of planning exercises spanning scales from the national, interconnection, to the utility. Results will highlight: lessons learned from the integrated planning exercises; the broad range in potential thermoelectric water use futures; regional differences in the thermoelectric-water nexus; and, opportunities for non-traditional waters to ease competition over limited freshwater supplies and to harden thermoelectric generation against drought vulnerability. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

A school-based resilience intervention to decrease tobacco, alcohol and marijuana use in high school students.

PubMed

Hodder, Rebecca K; Daly, Justine; Freund, Megan; Bowman, Jenny; Hazell, Trevor; Wiggers, John

2011-09-24

Despite schools theoretically being an ideal setting for accessing adolescents and preventing initiation of substance use, there is limited evidence of effective interventions in this setting. Resilience theory provides one approach to achieving such an outcome through improving adolescent mental well-being and resilience. A study was undertaken to examine the potential effectiveness of such an intervention approach in improving adolescent resilience and protective factor scores; and reducing the prevalence of adolescent tobacco, alcohol and marijuana use in three high schools. A non-controlled before and after study was undertaken. Data regarding student resilience and protective factors, and measures of tobacco, alcohol and marijuana use were collected from grade 7 to 10 students at baseline (n = 1449) and one year following a three year intervention (n = 1205). Significantly higher resilience and protective factors scores, and significantly lower prevalence of substance use were evident at follow up. The results suggest that the intervention has the potential to increase resilience and protective factors, and to decrease the use of tobacco, alcohol and marijuana by adolescents. Further more rigorous research is required to confirm this potential.

Shape-Independent Limits to Near-Field Radiative Heat Transfer

NASA Astrophysics Data System (ADS)

Miller, Owen D.; Johnson, Steven G.; Rodriguez, Alejandro W.

2015-11-01

We derive shape-independent limits to the spectral radiative heat transfer rate between two closely spaced bodies, generalizing the concept of a blackbody to the case of near-field energy transfer. Through conservation of energy and reciprocity, we show that each body of susceptibility χ can emit and absorb radiation at enhanced rates bounded by |χ |2/Im χ , optimally mediated by near-field photon transfer proportional to 1 /d2 across a separation distance d . Dipole-dipole and dipole-plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation (i.e., neglecting multiple scattering) exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and significantly greater at higher temperatures.

Electron transport limitation in P3HT:CdSe nanorods hybrid solar cells.

PubMed

Lek, Jun Yan; Xing, Guichuan; Sum, Tze Chien; Lam, Yeng Ming

2014-01-22

Hybrid solar cells have the potential to be efficient solar-energy-harvesting devices that can combine the benefits of solution-processable organic materials and the extended absorption offered by inorganic materials. In this work, an understanding of the factors limiting the performance of hybrid solar cells is explored. Through photovoltaic-device characterization correlated with transient absorption spectroscopy measurements, it was found that the interfacial charge transfer between the organic (P3HT) and inorganic (CdSe nanorods) components is not the factor limiting the performance of these solar cells. The insulating original ligands retard the charge recombination between the charge-transfer states across the CdSe-P3HT interface, and this is actually beneficial for charge collection. These cells are, in fact, limited by the subsequent electron collection via CdSe nanoparticles to the electrodes. Hence, the design of a more continuous electron-transport pathway should greatly improve the performance of hybrid solar cells in the future.

Factors that contribute to physician variability in decisions to limit life support in the ICU: a qualitative study.

PubMed

Wilson, Michael E; Rhudy, Lori M; Ballinger, Beth A; Tescher, Ann N; Pickering, Brian W; Gajic, Ognjen

2013-06-01

Our aim was to explore reasons for physician variability in decisions to limit life support in the intensive care unit (ICU) utilizing qualitative methodology. Single center study consisting of semi-structured interviews with experienced physicians and nurses. Seventeen intensivists from medical (n = 7), surgical (n = 5), and anesthesia (n = 5) critical care backgrounds, and ten nurses from medical (n = 5) and surgical (n = 5) ICU backgrounds were interviewed. Principles of grounded theory were used to analyze the interview transcripts. Eleven factors within four categories were identified that influenced physician variability in decisions to limit life support: (1) physician work environment-workload and competing priorities, shift changes and handoffs, and incorporation of nursing input; (2) physician experiences-of unexpected patient survival, and of limiting life support in physician's family; (3) physician attitudes-investment in a good surgical outcome, specialty perspective, values and beliefs; and (4) physician relationship with patient and family-hearing the patient's wishes firsthand, engagement in family communication, and family negotiation. We identified several factors which physicians and nurses perceived were important sources of physician variability in decisions to limit life support. Ways to raise awareness and ameliorate the potentially adverse effects of factors such as workload, competing priorities, shift changes, and handoffs should be explored. Exposing intensivists to long term patient outcomes, formalizing nursing input, providing additional training, and emphasizing firsthand knowledge of patient wishes may improve decision making.

Application of a framework for extrapolating chemical effects across species in pathways controlled by estrogen receptor-á

EPA Science Inventory

Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetic...

Limitations on orchid recruitment: not a simple picture

Treesearch

M.K. McCormick; D.L. Taylor; K Juhaszova; R.K Burnett; D.F. Whigham; J.P. O' Neill

2012-01-01

Mycorrhizal fungi have substantial potential to influence plant distribution, especially in specialized orchids and mycoheterotrophic plants. However, little is known about environmental factors that influence the distribution of mycorrhizal fungi. Previous studies using seed packets have been unable to distinguish whether germination patterns resulted from the...

Mammalian adaptation of influenza A(H7N9) virus is limited by a narrow genetic bottleneck

PubMed Central

Zaraket, Hassan; Baranovich, Tatiana; Kaplan, Bryan S.; Carter, Robert; Song, Min-Suk; Paulson, James C.; Rehg, Jerold E.; Bahl, Justin; Crumpton, Jeri C.; Seiler, Jon; Edmonson, Michael; Wu, Gang; Karlsson, Erik; Fabrizio, Thomas; Zhu, Huachen; Guan, Yi; Husain, Matloob; Schultz-Cherry, Stacey; Krauss, Scott; McBride, Ryan; Webster, Robert G.; Govorkova, Elena A.; Zhang, Jinghui; Russell, Charles J.; Webby, Richard J.

2015-01-01

Human infection with avian influenza A(H7N9) virus is associated mainly with the exposure to infected poultry. The factors that allow interspecies transmission but limit human-to-human transmission are unknown. Here we show that A/Anhui/1/2013(H7N9) influenza virus infection of chickens (natural hosts) is asymptomatic and that it generates a high genetic diversity. In contrast, diversity is tightly restricted in infected ferrets, limiting further adaptation to a fully transmissible form. Airborne transmission in ferrets is accompanied by the mutations in PB1, NP and NA genes that reduce viral polymerase and neuraminidase activity. Therefore, while A(H7N9) virus can infect mammals, further adaptation appears to incur a fitness cost. Our results reveal that a tight genetic bottleneck during avian-to-mammalian transmission is a limiting factor in A(H7N9) influenza virus adaptation to mammals. This previously unrecognized biological mechanism limiting species jumps provides a measure of adaptive potential and may serve as a risk assessment tool for pandemic preparedness. PMID:25850788

Limitations on scientific prediction and how they could affect repository licensing

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

Van Konynenburg, R.A.

The best possibility for gaining an understanding of the likely future behavior of a high level nuclear waste disposal system is to use the scientific method. However, the scientific approach has inherent limitations when it comes to making long-term predictions with confidence. This paper examines some of these limiting factors as well as the criteria for admissibility of scientific evidence in the legal arena, and concludes that the prospects are doubtful for successful licensing of a potential repository under the regulations that are now being reconsidered. Suggestions am made for remedying this situation.

Evaluation of the potential carcinogenicity of benzotrichloride (97-07-7). Final report

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

Not Available

1988-06-01

Benzotrichloride is a probable human carcinogen, classified as weight-of-evidence Group B1 under the EPA Guidelines for Carcinogen Risk Assessment. Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is Limited. The potency factor (F) for benzotrichloride is estimated to be 58.0 (mg/kg/day)(-1), placing it in potency group 2 according to the CAG's methodology for evaluating potential carcinogens. Combining the weight-of-evidence group and the potency group, benzotrichloride is assigned a MEDIUM hazard ranking.

Environmental limitation mapping of potential biomass resources across the conterminous United States

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

Daly, Christopher; Halbleib, Michael D.; Hannaway, David B.

Several crops have recently been identified as potential dedicated bioenergy feedstocks for the production of power, fuels, and bioproducts. Despite being identified as early as the 1980s, no systematic work has been undertaken to characterize the spatial distribution of their long-term production potentials in the United states. Such information is a starting point for planners and economic modelers, and there is a need for this spatial information to be developed in a consistent manner for a variety of crops, so that their production potentials can be intercompared to support crop selection decisions. As part of the Sun Grant Regional Feedstockmore » Partnership (RFP), an approach to mapping these potential biomass resources was developed to take advantage of the informational synergy realized when bringing together coordinated field trials, close interaction with expert agronomists, and spatial modeling into a single, collaborative effort. A modeling and mapping system called PRISM-ELM was designed to answer a basic question: How do climate and soil characteristics affect the spatial distribution and long-term production patterns of a given crop? This empirical/mechanistic/biogeographical hybrid model employs a limiting factor approach, where productivity is determined by the most limiting of the factors addressed in submodels that simulate water balance, winter low-temperature response, summer high-temperature response, and soil pH, salinity, and drainage. Yield maps are developed through linear regressions relating soil and climate attributes to reported yield data. The model was parameterized and validated using grain yield data for winter wheat and maize, which served as benchmarks for parameterizing the model for upland and lowland switchgrass, CRP grasses, Miscanthus, biomass sorghum, energycane, willow, and poplar. The resulting maps served as potential production inputs to analyses comparing the viability of biomass crops under various economic scenarios. The modeling and parameterization framework can be expanded to include other biomass crops.« less

Environmental limitation mapping of potential biomass resources across the conterminous United States

DOE PAGES

Daly, Christopher; Halbleib, Michael D.; Hannaway, David B.; ...

2017-12-22

Several crops have recently been identified as potential dedicated bioenergy feedstocks for the production of power, fuels, and bioproducts. Despite being identified as early as the 1980s, no systematic work has been undertaken to characterize the spatial distribution of their long-term production potentials in the United states. Such information is a starting point for planners and economic modelers, and there is a need for this spatial information to be developed in a consistent manner for a variety of crops, so that their production potentials can be intercompared to support crop selection decisions. As part of the Sun Grant Regional Feedstockmore » Partnership (RFP), an approach to mapping these potential biomass resources was developed to take advantage of the informational synergy realized when bringing together coordinated field trials, close interaction with expert agronomists, and spatial modeling into a single, collaborative effort. A modeling and mapping system called PRISM-ELM was designed to answer a basic question: How do climate and soil characteristics affect the spatial distribution and long-term production patterns of a given crop? This empirical/mechanistic/biogeographical hybrid model employs a limiting factor approach, where productivity is determined by the most limiting of the factors addressed in submodels that simulate water balance, winter low-temperature response, summer high-temperature response, and soil pH, salinity, and drainage. Yield maps are developed through linear regressions relating soil and climate attributes to reported yield data. The model was parameterized and validated using grain yield data for winter wheat and maize, which served as benchmarks for parameterizing the model for upland and lowland switchgrass, CRP grasses, Miscanthus, biomass sorghum, energycane, willow, and poplar. The resulting maps served as potential production inputs to analyses comparing the viability of biomass crops under various economic scenarios. The modeling and parameterization framework can be expanded to include other biomass crops.« less

Assessing risk factors for dental caries: a statistical modeling approach.

PubMed

Trottini, Mario; Bossù, Maurizio; Corridore, Denise; Ierardo, Gaetano; Luzzi, Valeria; Saccucci, Matteo; Polimeni, Antonella

2015-01-01

The problem of identifying potential determinants and predictors of dental caries is of key importance in caries research and it has received considerable attention in the scientific literature. From the methodological side, a broad range of statistical models is currently available to analyze dental caries indices (DMFT, dmfs, etc.). These models have been applied in several studies to investigate the impact of different risk factors on the cumulative severity of dental caries experience. However, in most of the cases (i) these studies focus on a very specific subset of risk factors; and (ii) in the statistical modeling only few candidate models are considered and model selection is at best only marginally addressed. As a result, our understanding of the robustness of the statistical inferences with respect to the choice of the model is very limited; the richness of the set of statistical models available for analysis in only marginally exploited; and inferences could be biased due the omission of potentially important confounding variables in the model's specification. In this paper we argue that these limitations can be overcome considering a general class of candidate models and carefully exploring the model space using standard model selection criteria and measures of global fit and predictive performance of the candidate models. Strengths and limitations of the proposed approach are illustrated with a real data set. In our illustration the model space contains more than 2.6 million models, which require inferences to be adjusted for 'optimism'.

Bioanode as a limiting factor to biocathode performance in microbial electrolysis cells.

PubMed

Lim, Swee Su; Yu, Eileen Hao; Daud, Wan Ramli Wan; Kim, Byung Hong; Scott, Keith

2017-08-01

The bioanode is important for a microbial electrolysis cell (MEC) and its robustness to maintain its catalytic activity affects the performance of the whole system. Bioanodes enriched at a potential of +0.2V (vs. standard hydrogen electrode) were able to sustain their oxidation activity when the anode potential was varied from -0.3 up to +1.0V. Chronoamperometric test revealed that the bioanode produced peak current density of 0.36A/m 2 and 0.37A/m 2 at applied potential 0 and +0.6V, respectively. Meanwhile hydrogen production at the biocathode was proportional to the applied potential, in the range from -0.5 to -1.0V. The highest production rate was 7.4L H 2 /(m 2 cathode area)/day at -1.0V cathode potential. A limited current output at the bioanode could halt the biocathode capability to generate hydrogen. Therefore maximum applied potential that can be applied to the biocathode was calculated as -0.84V without overloading the bioanode. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Diffusional conductance to CO2 is the key limitation to photosynthesis in salt-stressed leaves of rice (Oryza sativa).

PubMed

Wang, Xiaoxiao; Wang, Wencheng; Huang, Jianliang; Peng, Shaobing; Xiong, Dongliang

2018-05-01

Salinity significantly limits leaf photosynthesis but the factors causing the limitation in salt-stressed leaves remain unclear. In the present work, photosynthetic and biochemical traits were investigated in four rice genotypes under two NaCl concentration (0 and 150 mM) to assess the stomatal, mesophyll and biochemical contributions to reduced photosynthetic rate (A) in salt-stressed leaves. Our results indicated that salinity led to a decrease in A, leaf osmotic potential, electron transport rate and CO 2 concentrations in the chloroplasts (C c ) of rice leaves. Decreased A in salt-stressed leaves was mainly attributable to low C c , which was determined by stomatal and mesophyll conductance. The increased stomatal limitation was mainly related to the low leaf osmotic potential caused by soil salinity. However, the increased mesophyll limitation in salt-stressed leaves was related to both osmotic stress and ion stress. These findings highlight the importance of considering mesophyll conductance when developing salinity-tolerant rice cultivars. © 2017 Scandinavian Plant Physiology Society.

Biosurfactant gene clusters in eukaryotes: regulation and biotechnological potential.

PubMed

Roelants, Sophie L K W; De Maeseneire, Sofie L; Ciesielska, Katarzyna; Van Bogaert, Inge N A; Soetaert, Wim

2014-04-01

Biosurfactants (BSs) are a class of secondary metabolites representing a wide variety of structures that can be produced from renewable feedstock by a wide variety of micro-organisms. They have (potential) applications in the medical world, personal care sector, mining processes, food industry, cosmetics, crop protection, pharmaceuticals, bio-remediation, household detergents, paper and pulp industry, textiles, paint industries, etc. Especially glycolipid BSs like sophorolipids (SLs), rhamnolipids (RLs), mannosylerythritol lipids (MELs) and cellobioselipids (CBLs) have been described to provide significant opportunities to (partially) replace chemical surfactants. The major two factors currently limiting the penetration of BSs into the market are firstly the limited structural variety and secondly the rather high production price linked with the productivity. One of the keys to resolve the above mentioned bottlenecks can be found in the genetic engineering of natural producers. This could not only result in more efficient (economical) recombinant producers, but also in a diversification of the spectrum of available BSs as such resolving both limiting factors at once. Unraveling the genetics behind the biosynthesis of these interesting biological compounds is indispensable for the tinkering, fine tuning and rearrangement of these biological pathways with the aim of obtaining higher yields and a more extensive structural variety. Therefore, this review focuses on recent developments in the investigation of the biosynthesis, genetics and regulation of some important members of the family of the eukaryotic glycolipid BSs (MELs, CBLs and SLs). Moreover, recent biotechnological achievements and the industrial potential of engineered strains are discussed.

Drug-Induced Thrombophilic or Prothrombotic States: An Underestimated Clinical Problem That Involves Both Legal and Illegal Compounds.

PubMed

Girolami, A; Cosi, E; Tasinato, V; Santarossa, C; Ferrari, S; Girolami, B

2017-10-01

Vascular thrombosis, both arterial and venous, is a condition associated with significant morbidity and mortality. There are multiple risk factors for thrombosis, both congenital and acquired, and in the majority of cases, these risk factors are not modifiable. Over the past 2 decades, multiple drugs (both illegal and legal) have been associated with increased risk of thrombosis. However, due to limited scientific literature regarding the prothrombotic tendencies of these drugs, there is a concomitant limited understanding of the pathophysiology of drug-induced thrombosis. As drugs are one of the few modifiable risk factors for thrombosis, further study and dissemination of knowledge regarding drug-associated and drug-induced thrombosis are essential and have the potential to lead to decreased future incidence of thrombosis. The mechanisms at the basis of the thrombophilic activity of these drugs are variable and sometimes still ill recognized. Increased levels of clotting factors, reduction in coagulation natural inhibitors, decreased fibrinolysis, activated clotting factors, increased blood viscosity, endothelial damage, and increased platelet number and activation are the most frequent causes. Arterial steal or coronary arteries no flow has also been implicated. In some cases due to the intake of several drugs, more than one mechanism is present in a given patient. The purpose of the present review is to analyze all the drugs demonstrated to be potentially thrombotic. It is hoped that a prudent use or nonuse of these drugs might result in a reduction of thrombosis-associated diseases.

Mapping the global potential for marine aquaculture.

PubMed

Gentry, Rebecca R; Froehlich, Halley E; Grimm, Dietmar; Kareiva, Peter; Parke, Michael; Rust, Michael; Gaines, Steven D; Halpern, Benjamin S

2017-09-01

Marine aquaculture presents an opportunity for increasing seafood production in the face of growing demand for marine protein and limited scope for expanding wild fishery harvests. However, the global capacity for increased aquaculture production from the ocean and the relative productivity potential across countries are unknown. Here, we map the biological production potential for marine aquaculture across the globe using an innovative approach that draws from physiology, allometry and growth theory. Even after applying substantial constraints based on existing ocean uses and limitations, we find vast areas in nearly every coastal country that are suitable for aquaculture. The development potential far exceeds the space required to meet foreseeable seafood demand; indeed, the current total landings of all wild-capture fisheries could be produced using less than 0.015% of the global ocean area. This analysis demonstrates that suitable space is unlikely to limit marine aquaculture development and highlights the role that other factors, such as economics and governance, play in shaping growth trajectories. We suggest that the vast amount of space suitable for marine aquaculture presents an opportunity for countries to develop aquaculture in a way that aligns with their economic, environmental and social objectives.

The Relationship of Self-Efficacy and Complacency in Pilot-Automation Interaction

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III

2002-01-01

Pilot 'complacency' has been implicated as a contributing factor in numerous aviation accidents and incidents. The term has become more prominent with the increase in automation technology in modern cockpits and, therefore, research has been focused on understanding the factors that may mitigate its effect on pilot-automation interaction. The study examined self-efficacy of supervisory monitoring and the relationship between complacency on strategy of pilot use of automation for workload management under automation schedules that produce the potential for complacency. The results showed that self-efficacy can be a 'double-edged' sword in reducing potential for automation-induced complacency but limiting workload management strategies and increasing other hazardous states of awareness.

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

NASA Astrophysics Data System (ADS)

Schuback, N.; Flecken, M.; Maldonado, M. T.; Tortell, P. D.

2015-10-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation at PSII (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis, and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific, over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5 fold changes in the conversion factor coupling ETRRCII and carbon fixation (Φe:C / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light, and correlates with the expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and the conversion factor Φe:C / nPSII has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

An Aggregate IRT Procedure for Exploratory Factor Analysis

ERIC Educational Resources Information Center

Camilli, Gregory; Fox, Jean-Paul

2015-01-01

An aggregation strategy is proposed to potentially address practical limitation related to computing resources for two-level multidimensional item response theory (MIRT) models with large data sets. The aggregate model is derived by integration of the normal ogive model, and an adaptation of the stochastic approximation expectation maximization…

Do environmental factors affect male fathead minnow (Pimephales promelas) response to estrone? Part 2. Temperature and food availability

USDA-ARS?s Scientific Manuscript database

In nature, fish are subject to constantly changing environmental conditions and limitations on food availability, potentially impacting their response to endocrine disruptors. Outcome discrepancies between field studies and laboratory exposures of endocrine disruptors may be a result of these condi...

Indicators of Partnership Success among MICHIANA Coordinated School Health Teams

ERIC Educational Resources Information Center

Barnes, Priscilla A.; Lohrmann, David; Shipley, Meagan; O'Neill, Jim

2013-01-01

Coordinated school health (CSH) is an increasingly popular approach used by school and community stakeholders for implementing policy and programmatic changes. Because funding is limited, examination of factors that maximize the potential for schools to build sustainable partnerships is crucially important. This study assessed the extent to which…

Law-Related Education and Delinquency Prevention. ERIC Digest.

ERIC Educational Resources Information Center

Parrini, Michelle

Evidence from research/evaluation studies indicates that the principles underlying law-related education (LRE) programs address the factors that put youth at risk for delinquency. Although rigorous evaluations of LRE are limited, what evidence exists suggests that LRE has potential to prevent delinquency and problem behavior. This digest…

OVER-WINTER JUVENILE COHO SALMON GROWTH AND SURVIVAL IN A COASTAL OREGON STREAM NETWORK

EPA Science Inventory

Winter habitat has the potential to be a limiting factor for the production and condition of coho salmon (Oncorhynchus kisutch) smolts, but little is known about how the variation of habitat throughout whole stream networks influences coho smolts. Over a four year period (2002 - ...

Exploring Incomplete Rating Designs with Mokken Scale Analysis

ERIC Educational Resources Information Center

Wind, Stefanie A.; Patil, Yogendra J.

2018-01-01

Recent research has explored the use of models adapted from Mokken scale analysis as a nonparametric approach to evaluating rating quality in educational performance assessments. A potential limiting factor to the widespread use of these techniques is the requirement for complete data, as practical constraints in operational assessment systems…

44 CFR 9.8 - Public notice requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... provide adequate information to enable the public to have impact on the decision outcome for all actions... impact statement is being prepared, the Notice of Intent to File an EIS is adequate to constitute the... factors which include, but are not limited to: (i) Scale of the action; (ii) Potential for controversy...

44 CFR 9.8 - Public notice requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... provide adequate information to enable the public to have impact on the decision outcome for all actions... impact statement is being prepared, the Notice of Intent to File an EIS is adequate to constitute the... factors which include, but are not limited to: (i) Scale of the action; (ii) Potential for controversy...

Realizing the Potential of Ecosystem Services: A Framework for Relating Ecological Changes to Economic Benefits

EPA Science Inventory

An analysis framework to link ecological change to economic benefits for multiple stakeholders requires several key components. First, since we aim to support policy decisions, the framework should link a factor that can be controlled or influenced by policy (discharge limit, ca...

Cultural Schemata--Yardstick for Measuring Others: Implications for Teachers

ERIC Educational Resources Information Center

Plata, Maximino

2011-01-01

Classroom teachers' cultural schemata become important factors when they use them as the standard or yardstick to instruct culturally, linguistically, and economically diverse (CLED) students. However, when teachers' yardstick is comprised of limited cross-cultural knowledge and experiences, they cannot gauge the true learning potential of CLED…

Density and nest survival of golden-cheeked warblers: Spatial scale matters

Treesearch

Jennifer L. Reidy; Frank R., III Thompson; Lisa O' Donnell

2017-01-01

Conservation and management plans often rely on indicators such as species occupancy or density to define habitat quality, ignoring factors that influence reproductive success, and potentially limiting conservation achievements. We examined relationships between predicted density and nest survival with environmental features at multiple spatial scales for the golden-...

Social Media for Collaborative Learning: A Review of School Literature

ERIC Educational Resources Information Center

Henderson, Michael; Snyder, Ilana; Beale, Denise

2013-01-01

Social media are widely seen as having transformational potential in school education. However, there is a surprising lack of empirical research in schools about pedagogical designs using social media and particularly the factors that facilitate or hinder desirable outcomes. Consequently, this article offers a review of the limited empirical…

Towards low back support with a passive biomimetic exo-spine.

PubMed

Naf, Matthias B; De Rijcke, Laura; Guerrero, Carlos Rodriguez; Millard, Matthew; Vanderborght, Bram; Lefeber, Dirk

2017-07-01

Low-Back Pain (LBP) affects a large portion of the working population. Preventive exoskeletons have been proposed to reduce the moments on the lower back, specifically around the lumbosacral (L5/S1) joint. High correlation has been shown, between reducing the moments around the L5/S1 joint and intervertebral compression forces, which in turn have been identified as a risk factor for developing LBP. However, most passive back support exoskeletons use rigid plates or stiff beams to support the spine that limit the range of motion of the wearer. A large range of motion and versatility are especially desirable for industrial applications. To overcome these limitations, a passive biomimetic exo-spine has been designed, modelled and an initial prototype tested. Its potential to allow for a large range of motion, whilst at the same time limiting the most extreme and potentially harmful postures has been shown.

Conditions where random phase approximation becomes exact in the high-density limit

NASA Astrophysics Data System (ADS)

Morawetz, Klaus; Ashokan, Vinod; Bala, Renu; Pathak, Kare Narain

2018-04-01

It is shown that, in d -dimensional systems, the vertex corrections beyond the random phase approximation (RPA) or G W approximation scales with the power d -β -α of the Fermi momentum if the relation between Fermi energy and Fermi momentum is ɛf˜pfβ and the interacting potential possesses a momentum power law of ˜p-α . The condition d -β -α <0 specifies systems where RPA is exact in the high-density limit. The one-dimensional structure factor is found to be the interaction-free one in the high-density limit for contact interaction. A cancellation of RPA and vertex corrections render this result valid up to second order in contact interaction. For finite-range potentials of cylindrical wires a large-scale cancellation appears and is found to be independent of the width parameter of the wire. The proposed high-density expansion agrees with the quantum Monte Carlo simulations.

Under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear?

PubMed

Ye, Jian-Sheng; Pei, Jiu-Ying; Fang, Chao

2018-03-01

Understanding under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear is useful for accurately predicting the response of ecosystem function to global environmental change. Using long-term (2000-2016) net primary productivity (NPP)-precipitation datasets derived from satellite observations, we identify >5600pixels in the North Hemisphere landmass that fit either linear or nonlinear temporal NPP-precipitation relationships. Differences in climate (precipitation, radiation, ratio of actual to potential evapotranspiration, temperature) and soil factors (nitrogen, phosphorous, organic carbon, field capacity) between the linear and nonlinear types are evaluated. Our analysis shows that both linear and nonlinear types exhibit similar interannual precipitation variabilities and occurrences of extreme precipitation. Permutational multivariate analysis of variance suggests that linear and nonlinear types differ significantly regarding to radiation, ratio of actual to potential evapotranspiration, and soil factors. The nonlinear type possesses lower radiation and/or less soil nutrients than the linear type, thereby suggesting that nonlinear type features higher degree of limitation from resources other than precipitation. This study suggests several factors limiting the responses of plant productivity to changes in precipitation, thus causing nonlinear NPP-precipitation pattern. Precipitation manipulation and modeling experiments should combine with changes in other climate and soil factors to better predict the response of plant productivity under future climate. Copyright © 2017 Elsevier B.V. All rights reserved.

Europe. An analysis of changes in the consumption of alcoholic beverages: the interaction among consumption, related harms, contextual factors and alcoholic beverage control policies.

PubMed

Allamani, Allaman; Pepe, Pasquale; Baccini, Michela; Massini, Giulia; Voller, Fabio

2014-10-01

This AMPHORA study's aim was to investigate selected factors potentially affecting changes in consumption of alcoholic beverages in 12 European countries during the 1960s-2008 (an average increase in beer, decreases in wine and spirits, total alcohol drinking decrease). Both time series and artificial neural networks-based analyses were used. Results indicated that selected socio-demographic and economic factors showed an overall major impact on consumption changes; particularly urbanization, increased income, and older mothers' age at their childbirths were significantly associated with consumption increase or decrease, depending on the country. Alcoholic beverage control policies showed an overall minor impact on consumption changes: among them, permissive availability measures were significantly associated with consumption increases, while drinking and driving limits and availability restrictions were correlated with consumption decreases, and alcohol taxation and prices of the alcoholic beverages were not significantly correlated with consumption. Population ageing, older mother's age at childbirths, increased income and increases in female employment, as well as drink driving limitations were associated with the decrease of transport mortality. Study's limitations are noted.

Two distinct mechanisms silence chinmo in Drosophila neuroblasts and neuroepithelial cells to limit their self-renewal.

PubMed

Dillard, Caroline; Narbonne-Reveau, Karine; Foppolo, Sophie; Lanet, Elodie; Maurange, Cédric

2018-01-25

Whether common principles regulate the self-renewing potential of neural stem cells (NSCs) throughout the developing central nervous system is still unclear. In the Drosophila ventral nerve cord and central brain, asymmetrically dividing NSCs, called neuroblasts (NBs), progress through a series of sequentially expressed transcription factors that limits self-renewal by silencing a genetic module involving the transcription factor Chinmo. Here, we find that Chinmo also promotes neuroepithelium growth in the optic lobe during early larval stages by boosting symmetric self-renewing divisions while preventing differentiation. Neuroepithelium differentiation in late larvae requires the transcriptional silencing of chinmo by ecdysone, the main steroid hormone, therefore allowing coordination of neural stem cell self-renewal with organismal growth. In contrast, chinmo silencing in NBs is post-transcriptional and does not require ecdysone. Thus, during Drosophila development, humoral cues or tissue-intrinsic temporal specification programs respectively limit self-renewal in different types of neural progenitors through the transcriptional and post-transcriptional regulation of the same transcription factor. © 2018. Published by The Company of Biologists Ltd.

Neck, shoulder and low back pain in secondary schoolchildren in relation to schoolbag carriage: should the recommended weight limits be gender-specific?

PubMed

Dianat, Iman; Sorkhi, Nasibeh; Pourhossein, Aida; Alipour, Arezou; Asghari-Jafarabadi, Mohammad

2014-05-01

The occurrence of neck, shoulder and low back complaints in relation to schoolbag carriage and other potential risk factors were investigated in a cross-sectional study of 586 Iranian schoolchildren aged 12-14 years. The average load carried by schoolchildren was 2.8 kg. Neck, shoulder and low back complaints during the preceding month were reported by 35.3%, 26.1% and 33% of the students, respectively. Gender was an independent factor predicting musculoskeletal symptoms in schoolchildren. Girls were more likely than boys to suffer from neck, shoulder and low back complaints, although there was no significant difference between genders in terms of schoolbag carriage variables. The findings suggest that the recommended weight limit for schoolbag carriage may need to differ between boys and girls. The associations between schoolbag variables and reported symptoms are also discussed. The results provide evidence that the current weight limit should consider a broader combination of factors that influence the use of schoolbags. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Sit Up Straight

NASA Technical Reports Server (NTRS)

1998-01-01

BioMetric Systems has an exclusive license to the Posture Video Analysis Tool (PVAT) developed at Johnson Space Center. PVAT uses videos from Space Shuttle flights to identify limiting posture and other human factors in the workplace that could be limiting. The software also provides data that recommends appropriate postures for certain tasks and safe duration for potentially harmful positions. BioMetric Systems has further developed PVAT for use by hospitals, physical rehabilitation facilities, insurance companies, sports medicine clinics, oil companies, manufacturers, and the military.

Inhibition of epidermal growth factor receptor by ferulic acid and 4-vinylguaiacol in human breast cancer cells.

PubMed

Sudhagar, S; Sathya, S; Anuradha, R; Gokulapriya, G; Geetharani, Y; Lakshmi, B S

2018-02-01

To examine the potential of ferulic acid and 4-vinylguaiacol for inhibiting epidermal growth factor receptor (EGFR) in human breast cancer cells in vitro. Ferulic acid and 4-vinylguaiacol limit the EGF (epidermal growth factor)-induced breast cancer proliferation and new DNA synthesis. Western blot analysis revealed both ferulic acid and 4-vinylguaiacol exhibit sustained inhibition of EGFR activation through down-regulation of Tyr 1068 autophosphorylation. Molecular docking analysis shows ferulic acid forming hydrogen bond interaction with Lys 745 and Met 793 whereas, 4-vinylguaiacol forms two hydrogen bonds with Phe 856 and exhibits stronger hydrophobic interactions with multiple amino acid residues at the EGFR kinase domain. Ferulic acid and 4-vinylguaiacol could serve as a potential structure for the development of new small molecule therapeutics against EGFR.

Conflict resolution in insect societies.

PubMed

Ratnieks, Francis L W; Foster, Kevin R; Wenseleers, Tom

2006-01-01

Although best known for cooperation, insect societies also manifest many potential conflicts among individuals. These conflicts involve both direct reproduction by individuals and manipulation of the reproduction of colony members. Here we review five major areas of reproductive conflict in insect societies: (a) sex allocation, (b) queen rearing, (c) male rearing, (d) queen-worker caste fate, and (e) breeding conflicts among totipotent adults. For each area we discuss the basis for conflict (potential conflict), whether conflict is expressed (actual conflict), whose interests prevail (conflict outcome), and the factors that reduce colony-level costs of conflict (conflict resolution), such as factors that cause workers to work rather than to lay eggs. Reproductive conflicts are widespread, sometimes having dramatic effects on the colony. However, three key factors (kinship, coercion, and constraint) typically combine to limit the effects of reproductive conflict and often lead to complete resolution.

Delivery of small molecules for bone regenerative engineering: preclinical studies and potential clinical applications.

PubMed

Laurencin, Cato T; Ashe, Keshia M; Henry, Nicole; Kan, Ho Man; Lo, Kevin W-H

2014-06-01

Stimulation of bone regeneration using growth factors is a promising approach for musculoskeletal regenerative engineering. However, common limitations with protein growth factors, such as high manufacturing costs, protein instability, contamination issues, and unwanted immunogenic responses of the host reduce potential clinical applications. New strategies for bone regeneration that involve inexpensive and stable small molecules can obviate these problems and have a significant impact on the treatment of skeletal injury and diseases. Over the past decade, a large number of small molecules with the potential of regenerating skeletal tissue have been reported in the literature. Here, we review this literature, paying specific attention to the prospects for small molecule-based bone-regenerative engineering. We also review the preclinical study of small molecules associated with bone regeneration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of the reduction process of dopamine using paired pulse voltammetry

PubMed Central

Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.; Kim, In Young; Jang, Dong Pyo

2014-01-01

The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around −0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at −0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to −0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (−0.4V). These tests showed that relatively large amounts of DOQ are reduced to DA during the holding potential. The rate-limited reduction process was also confirmed with the increase of reduction in a lower pH environment. In addition to the mechanism of the reduction process of DA, we found that the differences between the responses of primary and secondary pulses in PPV were mainly dependent on the rate-limited reduction process during the holding potential. In conclusion, the reduction process may be one of the important factors to be considered in the kinetic analysis of DA and other electroactive species in brain tissue and in the design of new types of waveform in FSCV. PMID:24926227

Host-Directed Therapeutics as a Novel Approach for Tuberculosis Treatment.

PubMed

Kim, Ye-Ram; Yang, Chul-Su

2017-09-28

Despite significant efforts to improve the treatment of tuberculosis (TB), it remains a prevalent infectious disease worldwide owing to the limitations of current TB therapeutic regimens. Recent work on novel TB treatment strategies has suggested that directly targeting host factors may be beneficial for TB treatment. Such strategies, termed host-directed therapeutics (HDTs), focus on host-pathogen interactions. HDTs may be more effective than the currently approved TB drugs, which are limited by the long durations of treatment needed and the emergence of drug-resistant strains. Targets of HDTs include host factors such as cytokines, immune checkpoints, immune cell functions, and essential enzyme activities. This review article discusses examples of potentially promising HDTs and introduces novel approaches for their development.

Transmembrane transport of peptide type compounds: prospects for oral delivery

NASA Technical Reports Server (NTRS)

Lipka, E.; Crison, J.; Amidon, G. L.

1996-01-01

Synthesis and delivery of potential therapeutic peptides and peptidomimetic compounds has been the focus of intense research over the last 10 years. While it is widely recognized that numerous limitations apply to oral delivery of peptides, some of the limiting factors have been addressed and their mechanisms elucidated, which has lead to promising strategies. This article will briefly summarize the challenges, results and current approaches of oral peptide delivery and give some insight on future strategies. The barriers determining peptide bioavailability after oral administration are intestinal membrane permability, size limitations, intestinal and hepatic metabolism and in some cases solubility limitations. Poor membrane permeabilities of hydrophilic peptides might be overcome by structurally modifying the compounds, thus increasing their membrane partition characteristics and/or their affinity to carrier proteins. Another approach is the site-specific delivery of the peptide to the most permeable parts of the intestine. The current view on size limitation for oral drug delivery has neglected partition considerations. Recent studies suggest that compounds with a molecular weight up to 4000 might be significantly absorbed, assuming appropriate partition behavior and stability. Metabolism, probably the most significant factor in the absorption fate of peptides, might be controlled by coadministration of competitive enzyme inhibitors, structural modifications and administration of the compound as a well absorbed prodrug that is converted into the therapeutically active agent after its absorption. For some peptides poor solubility might present a limitation to oral absorption, an issue that has been addressed by mechanistically defining and therefore improving formulation parameters. Effective oral peptide delivery requires further development in understanding these complex mechanisms in order to maximize the therapeutic potential of this class of compounds.

Beneficial effect of post-deposition treatment in high-efficiency Cu(In,Ga)Se{sub 2} solar cells through reduced potential fluctuations

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

Jensen, S. A., E-mail: Soren.Jensen@nrel.gov, E-mail: Darius.Kuciauskas@nrel.gov; Glynn, S.; Kanevce, A.

World-record power conversion efficiencies for Cu(In,Ga)Se{sub 2} (CIGS) solar cells have been achieved via a post-deposition treatment with alkaline metals, which increases the open-circuit voltage and fill factor. We explore the role of the potassium fluoride (KF) post-deposition treatment in CIGS by employing energy- and time-resolved photoluminescence spectroscopy and electrical characterization combined with numerical modeling. The bulk carrier lifetime is found to increase with post-deposition treatment from 255 ns to 388 ns, which is the longest charge carrier lifetime reported for CIGS, and within ∼40% of the radiative limit. We find evidence that the post-deposition treatment causes a decrease in the electronicmore » potential fluctuations. These potential fluctuations have previously been shown to reduce the open-circuit voltage and the device efficiency in CIGS. Additionally, numerical simulations based on the measured carrier lifetimes and mobilities show a diffusion length of ∼10 μm, which is ∼4 times larger than the film thickness. Thus, carrier collection in the bulk is not a limiting factor for device efficiency. By considering differences in doping, bandgap, and potential fluctuations, we present a possible explanation for the voltage difference between KF-treated and untreated samples.« less

The Potential for Low-Temperature Abiotic Hydrogen Generation and a Hydrogen-Driven Deep Biosphere

PubMed Central

Huang, Shanshan; Thorseth, Ingunn H.

2011-01-01

Abstract The release and oxidation of ferrous iron during aqueous alteration of the mineral olivine is known to reduce aqueous solutions to such extent that molecular hydrogen, H2, forms. H2 is an efficient energy carrier and is considered basal to the deep subsurface biosphere. Knowledge of the potential for H2 generation is therefore vital to understanding the deep biosphere on Earth and on extraterrestrial bodies. Here, we provide a review of factors that may reduce the potential for H2 generation with a focus on systems in the core temperature region for thermophilic to hyperthermophilic microbial life. We show that aqueous sulfate may inhibit the formation of H2, whereas redox-sensitive compounds of carbon and nitrogen are unlikely to have significant effect at low temperatures. In addition, we suggest that the rate of H2 generation is proportional to the dissolution rate of olivine and, hence, limited by factors such as reactive surface areas and the access of water to fresh surfaces. We furthermore suggest that the availability of water and pore/fracture space are the most important factors that limit the generation of H2. Our study implies that, because of large heat flows, abundant olivine-bearing rocks, large thermodynamic gradients, and reduced atmospheres, young Earth and Mars probably offered abundant systems where microbial life could possibly have emerged. Key Words: Serpentinization—Olivine—Hydrogen—Deep biosphere—Water—Mars. Astrobiology 11, 711–724. PMID:21923409

Risk factors of postthrombotic syndrome before and after deep venous thrombosis treatment.

PubMed

Strijkers, Rob Hw; de Wolf, Mark Af; Wittens, Cees Ha

2017-07-01

Postthrombotic syndrome is the most common complication after deep venous thrombosis. Postthrombotic syndrome is a debilitating disease and associated with decreased quality of life and high healthcare costs. Postthrombotic syndrome is a chronic disease, and causative treatment options are limited. Prevention of postthrombotic syndrome is therefore very important. Not all patients develop postthrombotic syndrome. Risk factors have been identified to try to predict the risk of developing postthrombotic syndrome. Age, gender, and recurrent deep venous thrombosis are factors that cannot be changed. Deep venous thrombosis location and extent seem to predict severity of postthrombotic syndrome and are potentially suitable as patient selection criteria. Residual thrombosis and reflux are known to increase the incidence of postthrombotic syndrome, but are of limited use. More recently developed treatment options for deep venous thrombosis, such as new oral factor X inhibitors and catheter-directed thrombolysis, are available at the moment. Catheter-directed thrombolysis shows promising results in reducing the incidence of postthrombotic syndrome after deep venous thrombosis. The role of new oral factor X inhibitors in preventing postthrombotic syndrome is still to be determined.

HOX Genes as Potential Markers of Circulating Tumour Cells.

PubMed

Morgan, R; El-Tanani, M

2016-01-01

Circulating tumour cells (CTCs) have significant diagnostic potential as they can reflect both the presence and recurrence of a wide range of cancers. However, this potential continues to be limited by the lack of robust and accessible isolation technologies. An alternative to isolation might be their direct detection amongst other peripheral blood cells, although this would require markers that allow them to be distinguished from an exceptionally high background signal. This review assesses the potential role of HOX genes, a family of homeodomain containing transcription factors with key roles in both embryonic development and oncogenesis, as unique and possibly disease specific markers of CTCs.

Strength of the interatomic potential derived from angular scans in LEIS

NASA Astrophysics Data System (ADS)

Primetzhofer, D.; Markin, S. N.; Draxler, M.; Beikler, R.; Taglauer, E.; Bauer, P.

2008-09-01

Angular scans were performed for a Cu(1 0 0) single crystal and He + ions. The results were compared to MARLOWE, KALYPSO and FAN simulations to obtain information on the interaction potential. The influence of the used evaluation procedure on the deduced scattering potential was investigated. The scattering potential is found to be weaker than what is predicted by an uncorrected TFM potential. It was found that the use of a single screening correction factor is applicable in a wide range of impact parameters. It is further shown that selection of single scattering trajectories and a limitation of information depth to the surface layers is possible for neutral and charge integrated spectra.

An overview of cytokines and cytokine antagonists as therapeutic agents.

PubMed

Donnelly, Raymond P; Young, Howard A; Rosenberg, Amy S

2009-12-01

Cytokine-based therapies have the potential to provide novel treatments for cancer, autoimmune diseases, and many types of infectious disease. However, to date, the full clinical potential of cytokines as drugs has been limited by a number of factors. To discuss these limitations and explore ways to overcome them, the FDA partnered with the New York Academy of Sciences in March 2009 to host a two-day forum to discuss more effective ways to harness the clinical potential of cytokines and cytokine antagonists as therapeutic agents. The first day was focused primarily on the use of recombinant cytokines as therapeutic agents for treatment of human diseases. The second day focused largely on the use of cytokine antagonists as therapeutic agents for treatment of human diseases. This issue of the Annals includes more than a dozen papers that summarize much of the information that was presented during this very informative two-day conference.

Recruitment strategies should not be randomly selected: empirically improving recruitment success and diversity in developmental psychology research

PubMed Central

Sugden, Nicole A.; Moulson, Margaret C.

2015-01-01

Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: (1) recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy), (2) recruiters of particular races were more successful than recruiters of other races, and (3) differences in success were related to what the recruiter said to engage the potential participant (i.e., the script). The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: (1) some scripts were more successful than others and (2) we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families. PMID:25972829

Hyperdynamics boost factor achievable with an ideal bias potential

DOE PAGES

Huang, Chen; Perez, Danny; Voter, Arthur F.

2015-08-20

Hyperdynamics is a powerful method to significantly extend the time scales amenable to molecular dynamics simulation of infrequent events. One outstanding challenge, however, is the development of the so-called bias potential required by the method. In this work, we design a bias potential using information about all minimum energy pathways (MEPs) out of the current state. While this approach is not suitable for use in an actual hyperdynamics simulation, because the pathways are generally not known in advance, it allows us to show that it is possible to come very close to the theoretical boost limit of hyperdynamics while maintainingmore » high accuracy. We demonstrate this by applying this MEP-based hyperdynamics (MEP-HD) to metallic surface diffusion systems. In most cases, MEP-HD gives boost factors that are orders of magnitude larger than the best existing bias potential, indicating that further development of hyperdynamics bias potentials could have a significant payoff. Lastly, we discuss potential practical uses of MEP-HD, including the possibility of developing MEP-HD into a true hyperdynamics.« less

Applications of Optical Neuroimaging in Usability Research

PubMed Central

Hill, Audrey P.; Bohil, Corey J.

2016-01-01

FEATURE AT A GLANCE In this article we review recent and potential applications of optical neuroimaging to human factors and usability research. We focus specifically on functional near-infrared spectroscopy (fNIRS) because of its cost-effectiveness and ease of implementation. Researchers have used fNIRS to assess a range of psychological phenomena relevant to human factors, such as cognitive workload, attention, motor activity, and more. It offers the opportunity to measure hemodynamic correlates of mental activity during task completion in human factors and usability studies. We also consider some limitations and future research directions. PMID:28286404

Post-hit dynamics of price limit hits in the Chinese stock markets

NASA Astrophysics Data System (ADS)

Wu, Ting; Wang, Yue; Li, Ming-Xia

2017-01-01

Price limit trading rules are useful to cool off traders short-term trading mania on individual stocks. The price dynamics approaching the limit boards are known as the magnet effect. However, the price dynamics after opening price limit hits are not well investigated. Here, we provide a detailed analysis on the price dynamics after the hits of up-limit or down-limit is open based on all A-share stocks traded in the Chinese stock markets. A "W" shape is found in the expected return, which reveals high probability of a continuous price limit hit on the following day. We also find that price dynamics after opening limit hits are dependent on the market trends. The time span of continuously hitting the price limit is found to an influence factor of the expected profit after the limit hit is open. Our analysis provides a better understanding of the price dynamics around the limit boards and contributes potential practical values for investors.

Cell wall and enzyme changes during the graviresponse of the leaf-sheath pulvinus of oat (Avena sativa)

NASA Technical Reports Server (NTRS)

Gibeaut, David M.; Karuppiah, Nadarajah; Chang, S.-R.; Brock, Thomas G.; Vadlamudi, Babu; Kim, Donghern; Ghosheh, Najati S.; Rayle, David L.; Carpita, Nicholas C.; Kaufman, Peter B.

1990-01-01

The graviresponse of the leaf-sheath pulvinus of oat (Avena sativa) involves an asymmetric growth response and asymmetric processes involving degradation of starch and cell wall synthesis. Cellular and biochemical events were studied by investigation of the activities of related enzymes and changes in cell walls and their constituents. It is suggested that an osmotic potential gradient acts as the driving factor for growth, while wall extensibility is a limiting factor in pulvinus growth.

Biophysical and economic limits to negative CO2 emissions

NASA Astrophysics Data System (ADS)

Smith, Pete; Davis, Steven J.; Creutzig, Felix; Fuss, Sabine; Minx, Jan; Gabrielle, Benoit; Kato, Etsushi; Jackson, Robert B.; Cowie, Annette; Kriegler, Elmar; van Vuuren, Detlef P.; Rogelj, Joeri; Ciais, Philippe; Milne, Jennifer; Canadell, Josep G.; McCollum, David; Peters, Glen; Andrew, Robbie; Krey, Volker; Shrestha, Gyami; Friedlingstein, Pierre; Gasser, Thomas; Grübler, Arnulf; Heidug, Wolfgang K.; Jonas, Matthias; Jones, Chris D.; Kraxner, Florian; Littleton, Emma; Lowe, Jason; Moreira, José Roberto; Nakicenovic, Nebojsa; Obersteiner, Michael; Patwardhan, Anand; Rogner, Mathis; Rubin, Ed; Sharifi, Ayyoob; Torvanger, Asbjørn; Yamagata, Yoshiki; Edmonds, Jae; Yongsung, Cho

2016-01-01

To have a >50% chance of limiting warming below 2 °C, most recent scenarios from integrated assessment models (IAMs) require large-scale deployment of negative emissions technologies (NETs). These are technologies that result in the net removal of greenhouse gases from the atmosphere. We quantify potential global impacts of the different NETs on various factors (such as land, greenhouse gas emissions, water, albedo, nutrients and energy) to determine the biophysical limits to, and economic costs of, their widespread application. Resource implications vary between technologies and need to be satisfactorily addressed if NETs are to have a significant role in achieving climate goals.

The intricate relationship between a medical school and a teaching hospital: A case study in Uganda.

PubMed

Mubuuke, Aloysius Gonzaga; Businge, Francis; Mukule, Emmanuel

2014-01-01

The relationship between medical schools and teaching hospitals is full of opportunities but also challenges even though they have complementary goals that could enhance each other. Although medical schools and teaching hospitals may face some similar challenges around the world, there could be context-specific observations that differ in resource-rich versus resource-limited settings. The purpose of this study was to investigate factors that are perceived to have influenced the relationship between a medical school and a teaching hospital in Uganda, a resource-limited setting. This was a cross-sectional, descriptive study in which key informant individual interviews were conducted with senior administrators and senior staff members of the Mulago Hospital and Makerere University Medical School. The interviews explored factors perceived to have favoured the working relationship between the two institutions, challenges faced and likely future opportunities. Both quantitative and qualitative data were generated. Thematic analysis was used with the qualitative data. Respondents reported a strained relationship between the two institutions, with unfavourable factors far outweighing the favourable factors influencing the relationship. Key negative reported factors included having different administrative set-ups, limited opportunities to share funds and to forge research collaborations, unexploited potential of sharing human resources to address staff shortages, as well as a lack of a memorandum of understanding between the two institutions. This study identifies barriers in the existing relationship between a teaching hospital and medical college in a resource-poor country. It proposes a collaborative model, rather than competitive model, for the two institutions that may work in both resource-limited and resource-rich settings.

pH, redox potential and local biofilm potential microenvironments within Geobacter sulfurreducens biofilms and their roles in electron transfer.

PubMed

Babauta, Jerome T; Nguyen, Hung Duc; Harrington, Timothy D; Renslow, Ryan; Beyenal, Haluk

2012-10-01

The limitation of pH inside electrode-respiring biofilms is a well-known concept. However, little is known about how pH and redox potential are affected by increasing current inside biofilms respiring on electrodes. Quantifying the variations in pH and redox potential with increasing current is needed to determine how electron transfer is tied to proton transfer within the biofilm. In this research, we quantified pH and redox potential variations in electrode-respiring Geobacter sulfurreducens biofilms as a function of respiration rates, measured as current. We also characterized pH and redox potential at the counter electrode. We concluded that (1) pH continued to decrease in the biofilm through different growth phases, showing that the pH is not always a limiting factor in a biofilm and (2) decreasing pH and increasing redox potential at the biofilm electrode were associated only with the biofilm, demonstrating that G. sulfurreducens biofilms respire in a unique internal environment. Redox potential inside the biofilm was also compared to the local biofilm potential measured by a graphite microelectrode, where the tip of the microelectrode was allowed to acclimatize inside the biofilm. Copyright © 2012 Wiley Periodicals, Inc.

Opportunities for Reducing Nitrate Export from Drainage Systems through In-field Nitrogen Management, Cropping Practices, and Drainage Design and Management

NASA Astrophysics Data System (ADS)

Helmers, M.; Zhou, X.; Qi, Z.; Christianson, R.; Pederson, C.

2011-12-01

Subsurface drainage systems are widely used throughout the upper Midwest corn-belt. While the use of these drainage systems has greatly increased crop production, they have also increased nitrate-nitrogen export to downstream waterbodies. As a result, there is a need to evaluate and implement management practices that have potential to reduce nitrate-nitrogen loss. A twenty year study in Iowa has shown that major factors in nitrate-nitrogen loss are land use and hydrology. Studies from north-central Iowa have also indicated that nitrogen application rate and to a lesser degree timing of nitrogen application important factors for nitrate-nitrogen loss. A four-year (2007-2010) drainage management study in southeast Iowa indicates that shallow and controlled drainage systems have potential to decrease subsurface drainage and thereby reduce nitrate-N loss from drain water but the level of implementation of controlled drainage may be limited by topography. Cropping practices through cover crops or perennial biomass crops have also been documented to have potential to reduce downstream nitrate-nitrogen export but the level of implementation may be limited by management and economic considerations. To achieve reduction goals for protection of local and regional water quality will require a combination of these practices at the landscape scale.

Limitations and potentials of current motif discovery algorithms

PubMed Central

Hu, Jianjun; Li, Bin; Kihara, Daisuke

2005-01-01

Computational methods for de novo identification of gene regulation elements, such as transcription factor binding sites, have proved to be useful for deciphering genetic regulatory networks. However, despite the availability of a large number of algorithms, their strengths and weaknesses are not sufficiently understood. Here, we designed a comprehensive set of performance measures and benchmarked five modern sequence-based motif discovery algorithms using large datasets generated from Escherichia coli RegulonDB. Factors that affect the prediction accuracy, scalability and reliability are characterized. It is revealed that the nucleotide and the binding site level accuracy are very low, while the motif level accuracy is relatively high, which indicates that the algorithms can usually capture at least one correct motif in an input sequence. To exploit diverse predictions from multiple runs of one or more algorithms, a consensus ensemble algorithm has been developed, which achieved 6–45% improvement over the base algorithms by increasing both the sensitivity and specificity. Our study illustrates limitations and potentials of existing sequence-based motif discovery algorithms. Taking advantage of the revealed potentials, several promising directions for further improvements are discussed. Since the sequence-based algorithms are the baseline of most of the modern motif discovery algorithms, this paper suggests substantial improvements would be possible for them. PMID:16284194

Electrophysiological Indices of Brain Activity to Content and Function Words in Discourse

ERIC Educational Resources Information Center

Neumann, Yael; Epstein, Baila; Shafer, Valerie L.

2016-01-01

Background: An increase in positivity of event-related potentials (ERPs) at the lateral anterior sites has been hypothesized to be an index of semantic and discourse processing, with the right lateral anterior positivity (LAP) showing particular sensitivity to discourse factors. However, the research investigating the LAP is limited; it is unclear…

Comparison of arabidopsis stomatal density mutants indicates variation in water stress responses and potential epistatic effects

Treesearch

Shaneka S. Lawson; Paula M. Pijut; Charles H. Michler

2014-01-01

Recent physiological analysis of Arabidopsis stomatal density (SD) mutants indicated that SD was not the major factor controlling aboveground biomass accumulation. Despite the general theory that plants with fewer stomata have limited biomass acquisition capabilities, epf1 and several other Arabidopsis mutants varied significantly in leaf fresh...

Systematic review of the influence of foraging habitat on red-cockaded woodpecker reproductive success

Treesearch

James E. Garabedian; Christopher E. Moorman; M. Nils Peterson; John C. Kilgo

2014-01-01

Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides...

Evaluation of cover crops drill interseeded into corn across the mid-Atlantic region

USDA-ARS?s Scientific Manuscript database

Cover crop adoption remains low in the mid-Atlantic region despite the potential conservation and production benefits. The short growing season window after corn (Zea mays L.), is a primary factor limiting cover crop adoption in these regions. A high-clearance grain drill has been developed to allow...

Quantifying targets to manage invasion risk: light gradients dominate the early regeneration niche of naturalized and pre-commercial Miscanthus populations

USDA-ARS?s Scientific Manuscript database

Prospective bioenergy crops have caused concern about their invasive potential because they often share characteristics with known invasive species. Studies that examine the factors that limit regeneration of these crop species will be crucial for identifying vulnerable habitats and devising managem...

42 CFR 410.16 - Initial preventive physical examination: Conditions for and limitations on coverage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... preventive examination not more than 1 year after the effective date of his or her first Medicare Part B... potential (risk factors) for depression, including current or past experiences with depression or other mood... use of appropriate screening questions or a screening questionnaire, which the physician or other...

Discussing the Factors Contributing to Students' Involvement in an EFL Collaborative Wiki Project

ERIC Educational Resources Information Center

Lee, Hsiao-chien; Wang, Pei-ling

2013-01-01

A growing number of researchers have acknowledged the potential for using wikis in online collaborative language learning. While researchers appreciate the wikis platform for engaging students in virtual team work and authentic language learning, many also have recognized the limitations of using wikis to promote student collaboration (Alyousef…

Facilitating Teachers' Reuse of Mobile Assisted Language Learning Resources Using Educational Metadata

ERIC Educational Resources Information Center

Zervas, Panagiotis; Sampson, Demetrios G.

2014-01-01

Mobile assisted language learning (MALL) and open access repositories for language learning resources are both topics that have attracted the interest of researchers and practitioners in technology enhanced learning (TeL). Yet, there is limited experimental evidence about possible factors that can influence and potentially enhance reuse of MALL…

Phi 6 and Phi 8 as Potential Surrogates for Avian Influenza Viruses in Persistence Studies in Water-Abstract

EPA Science Inventory

Wild aquatic birds are the natural reservoir for avian influenza viruses, and water is known to play an important role in the transmission of virus within this reservoir system. Despite its recognized importance, we have very little understanding of what factors enhance or limit...

Phi 6 and Phi 8 as Potential Surrogates for Avian Influenza Viruses in Persistence Studies in Water - Poster

EPA Science Inventory

Wild aquatic birds are the natural reservoir for avian influenza viruses, and water is known to play an important role in the transmission of virus within this reservoir system. Despite its recognized importance, we have very little understanding of what factors enhance or limit...

Genome-wide association mapping of carbon isotope and oxygen isotope ratios in diverse soybean genotypes

USDA-ARS?s Scientific Manuscript database

Water deficit stress is a major factor limiting soybean [Glycine max (L.) Merr.] yield. High water use efficiency (WUE) offers a means to potentially ameliorate drought impact, but increased WUE is often associated with a reduction in transpiration (T) and an accompanied reduction in photosynthesis....

Aging Memory Is "Not" a Limiting Factor for Lifelong Learning

ERIC Educational Resources Information Center

Lalovic, Dejan; Gvozdenovic, Vasilije

2015-01-01

Efficient memory is one of the necessary cognitive potentials required for virtually every form of lifelong learning. In this contribution we first briefly review and summarize state of the art of knowledge on memory and related cognitive functions in normal aging. Then we critically discuss a relatively short inventory of clinical, psychometric,…

Teacher- and School-Level Predictors of Teacher Efficacy and Burnout: Identifying Potential Areas for Support

ERIC Educational Resources Information Center

Pas, Elise T.; Bradshaw, Catherine P.; Hershfeldt, Patricia A.

2012-01-01

Although several studies relate low teacher efficacy and high burnout to the quality of instruction and students' academic achievement, there has been limited research examining factors that predict teacher efficacy and burnout. The current study employed a longitudinal, multilevel modeling approach to examine the influence of teacher- and…

40 CFR 63.420 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-CE)+0.17 (TE)+0.08(TES)+0.038(TI)+8.5×10-6(C)+KQ]+0.04(OE) where: ET = emissions screening factor for... efficiency limitation on potential to emit for the vapor processing system used to control emissions from... of external floating roof gasoline storage vessels with only primary seals; TES = total number of...

40 CFR 63.420 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-CE)+0.17 (TE)+0.08(TES)+0.038(TI)+8.5×10-6(C)+KQ]+0.04(OE) where: ET = emissions screening factor for... efficiency limitation on potential to emit for the vapor processing system used to control emissions from... of external floating roof gasoline storage vessels with only primary seals; TES = total number of...

40 CFR 63.420 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-CE)+0.17 (TE)+0.08(TES)+0.038(TI)+8.5×10-6(C)+KQ]+0.04(OE) where: ET = emissions screening factor for... efficiency limitation on potential to emit for the vapor processing system used to control emissions from... of external floating roof gasoline storage vessels with only primary seals; TES = total number of...

40 CFR 63.420 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-CE)+0.17 (TE)+0.08(TES)+0.038(TI)+8.5×10-6(C)+KQ]+0.04(OE) where: ET = emissions screening factor for... efficiency limitation on potential to emit for the vapor processing system used to control emissions from... of external floating roof gasoline storage vessels with only primary seals; TES = total number of...

40 CFR 63.420 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

...)(1-CE)+0.17 (TE)+0.08(TES)+0.038(TI)+8.5×10-6(C)+KQ]+0.04(OE) where: ET = emissions screening factor... efficiency limitation on potential to emit for the vapor processing system used to control emissions from... of external floating roof gasoline storage vessels with only primary seals; TES = total number of...

Personal and couple level risk factors: Maternal and paternal parent-child aggression risk.

PubMed

Tucker, Meagan C; Rodriguez, Christina M; Baker, Levi R

2017-07-01

Previous literature examining parent-child aggression (PCA) risk has relied heavily upon mothers, limiting our understanding of paternal risk factors. Moreover, the extent to which factors in the couple relationship work in tandem with personal vulnerabilities to impact PCA risk is unclear. The current study examined whether personal stress and distress predicted PCA risk (child abuse potential, over-reactive discipline style, harsh discipline practices) for fathers as well as mothers and whether couple functioning mediated versus moderated the relation between personal stress and PCA risk in a sample of 81 couples. Additionally, the potential for risk factors in one partner to cross over and affect their partner's PCA risk was considered. Findings indicated higher personal stress predicted elevated maternal and paternal PCA risk. Better couple functioning did not moderate this relationship but partially mediated stress and PCA risk for both mothers and fathers. In addition, maternal stress evidenced a cross-over effect, wherein mothers' personal stress linked to fathers' couple functioning. Findings support the role of stress and couple functioning in maternal and paternal PCA risk, including potential cross-over effects that warrant further inquiry. Copyright © 2017 Elsevier Ltd. All rights reserved.

A school-based resilience intervention to decrease tobacco, alcohol and marijuana use in high school students

PubMed Central

2011-01-01

Background Despite schools theoretically being an ideal setting for accessing adolescents and preventing initiation of substance use, there is limited evidence of effective interventions in this setting. Resilience theory provides one approach to achieving such an outcome through improving adolescent mental well-being and resilience. A study was undertaken to examine the potential effectiveness of such an intervention approach in improving adolescent resilience and protective factor scores; and reducing the prevalence of adolescent tobacco, alcohol and marijuana use in three high schools. Methods A non-controlled before and after study was undertaken. Data regarding student resilience and protective factors, and measures of tobacco, alcohol and marijuana use were collected from grade 7 to 10 students at baseline (n = 1449) and one year following a three year intervention (n = 1205). Results Significantly higher resilience and protective factors scores, and significantly lower prevalence of substance use were evident at follow up. Conclusions The results suggest that the intervention has the potential to increase resilience and protective factors, and to decrease the use of tobacco, alcohol and marijuana by adolescents. Further more rigorous research is required to confirm this potential. PMID:21942951

Cyclic voltammetry of fast conducting electrocatalytic films.

PubMed

Costentin, Cyrille; Savéant, Jean-Michel

2015-07-15

In the framework of contemporary energy challenges, cyclic voltammetry is a particularly useful tool for deciphering the kinetics of catalytic films. The case of fast conducting films is analyzed, whether conduction is of the ohmic type or proceeds through rapid electron hopping. The rate-limiting factors are then the diffusion of the substrate in solution and through the film as well as the catalytic reaction itself. The dimensionless combination of the characteristics of these factors allows reducing the number of actual parameters to a maximum of two. The kinetics of the system may then be fully analyzed with the help of a kinetic zone diagram. Observing the variations of the current-potential responses with operational parameters such as film thickness, the potential scan rate and substrate concentration allows a precise assessment of the interplay between these factors and of the values of the rate controlling factors. A series of thought experiments is described in order to render the kinetic analysis more palpable.

Spiritual quality of life and spiritual coping: evidence for a two-factor structure of the WHOQOL spirituality, religiousness, and personal beliefs module.

PubMed

Krägeloh, Christian U; Billington, D Rex; Henning, Marcus A; Chai, Penny Pei Minn

2015-02-25

The WHOQOL-SRPB has been a useful module to measure aspects of QOL related to spirituality, religiousness, and personal beliefs, but recent research has pointed to potential problems with its proposed factor structure. Three of the eight facets of the WHOQOL-SRPB have been identified as potentially different from the others, and to date only a limited number of factor analyses of the instrument have been published. Analyses were conducted using data from a sample of 679 university students who had completed the WHOQOL-BREF quality of life questionnaire, the WHOQOL-SRPB module, the Perceived Stress scale, and the Brief COPE coping strategies questionnaire. Informed by these analyses, confirmatory factor analyses suitable for ordinal-level data explored the potential for a two-factor solution as opposed to the originally proposed one-factor solution. The facets WHOQOL-SRPB facets connected, strength, and faith were highly correlated with each other as well as with the religious coping sub-scale of the Brief COPE. Combining these three facets to one factor in a two-factor solution for the WHOQOL-SRPB yielded superior goodness-of-fit indices compared to the original one-factor solution. A two-factor solution for the WHOQOL-SRPB is more tenable, in which three of the eight WHOQOL-SRPB facets group together as a spiritual coping factor and the remaining facets form a factor of spiritual quality of life. While discarding the facets connectedness, strength, and faith without additional research would be premature, users of the scale need to be aware of this alternative two-factor structure, and may wish to analyze scores using this structure.

Synthetic biology regulation and governance: Lessons from TAPIC for the United States, European Union, and Singapore.

PubMed

Trump, Benjamin D

2017-11-01

Synthetic biology is an emerging technology with potential benefits to various fields, yet also contains potential risks to human and environmental health. The field remains in an emerging state with limited quantitative guidance and a small but growing population of international researchers that conduct work within this field. Given the uncertain nature of this technology, an adaptive and anticipatory governance framework may be necessary to balance the potential benefits that may accrue from the technology's continued research alongside a desire to reduce or eliminate potential risks that may arise. However, such developments must account for the unique political and institutional factors that form a government's risk culture - something that can facilitate or impede the development of adaptive synthetic biology governance moving forward. The TAPIC framework helps illustrate those factors that are essential to develop good governance for emerging technologies like synthetic biology. Specifically, an application of TAPIC to synthetic biology governance indicates that the factors of accountability, participation, and integrity must be bolstered to improve technology governance in governments like with the United States, European Union, and Singapore. Copyright © 2017. Published by Elsevier B.V.

Selection bias in rheumatic disease research.

PubMed

Choi, Hyon K; Nguyen, Uyen-Sa; Niu, Jingbo; Danaei, Goodarz; Zhang, Yuqing

2014-07-01

The identification of modifiable risk factors for the development of rheumatic conditions and their sequelae is crucial for reducing the substantial worldwide burden of these diseases. However, the validity of such research can be threatened by sources of bias, including confounding, measurement and selection biases. In this Review, we discuss potentially major issues of selection bias--a type of bias frequently overshadowed by other bias and feasibility issues, despite being equally or more problematic--in key areas of rheumatic disease research. We present index event bias (a type of selection bias) as one of the potentially unifying reasons behind some unexpected findings, such as the 'risk factor paradox'--a phenomenon exemplified by the discrepant effects of certain risk factors on the development versus the progression of osteoarthritis (OA) or rheumatoid arthritis (RA). We also discuss potential selection biases owing to differential loss to follow-up in RA and OA research, as well as those due to the depletion of susceptibles (prevalent user bias) and immortal time bias. The lesson remains that selection bias can be ubiquitous and, therefore, has the potential to lead the field astray. Thus, we conclude with suggestions to help investigators avoid such issues and limit the impact on future rheumatology research.

Selection bias in rheumatic disease research

PubMed Central

Choi, Hyon K.; Nguyen, Uyen-Sa; Niu, Jingbo; Danaei, Goodarz; Zhang, Yuqing

2014-01-01

The identification of modifiable risk factors for the development of rheumatic conditions and their sequelae is crucial for reducing the substantial worldwide burden of these diseases. However, the validity of such research can be threatened by sources of bias, including confounding, measurement and selection biases. In this Review, we discuss potentially major issues of selection bias—a type of bias frequently overshadowed by other bias and feasibility issues, despite being equally or more problematic—in key areas of rheumatic disease research. We present index event bias (a type of selection bias) as one of the potentially unifying reasons behind some unexpected findings, such as the ‘risk factor paradox’—a phenomenon exemplified by the discrepant effects of certain risk factors on the development versus the progression of osteoarthritis (OA) or rheumatoid arthritis (RA). We also discuss potential selection biases owing to differential loss to follow-up in RA and OA research, as well as those due to the depletion of susceptibles (prevalent user bias) and immortal time bias. The lesson remains that selection bias can be ubiquitous and, therefore, has the potential to lead the field astray. Thus, we conclude with suggestions to help investigators avoid such issues and limit the impact on future rheumatology research. PMID:24686510

Sampling bias in an internet treatment trial for depression.

PubMed

Donkin, L; Hickie, I B; Christensen, H; Naismith, S L; Neal, B; Cockayne, N L; Glozier, N

2012-10-23

Internet psychological interventions are efficacious and may reduce traditional access barriers. No studies have evaluated whether any sampling bias exists in these trials that may limit the translation of the results of these trials into real-world application. We identified 7999 potentially eligible trial participants from a community-based health cohort study and invited them to participate in a randomized controlled trial of an online cognitive behavioural therapy programme for people with depression. We compared those who consented to being assessed for trial inclusion with nonconsenters on demographic, clinical and behavioural indicators captured in the health study. Any potentially biasing factors were then assessed for their association with depression outcome among trial participants to evaluate the existence of sampling bias. Of the 35 health survey variables explored, only 4 were independently associated with higher likelihood of consenting-female sex (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.05-1.19), speaking English at home (OR 1.48, 95% CI 1.15-1.90) higher education (OR 1.67, 95% CI 1.46-1.92) and a prior diagnosis of depression (OR 1.37, 95% CI 1.22-1.55). The multivariate model accounted for limited variance (C-statistic 0.6) in explaining participation. These four factors were not significantly associated with either the primary trial outcome measure or any differential impact by intervention arm. This demonstrates that, among eligible trial participants, few factors were associated with the consent to participate. There was no indication that such self-selection biased the trial results or would limit the generalizability and translation into a public or clinical setting.

Effective bichromatic potential for ultra-high Q-factor photonic crystal slab cavities

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

Alpeggiani, Filippo, E-mail: filippo.alpeggiani01@ateneopv.it; Andreani, Lucio Claudio; Gerace, Dario

2015-12-28

We introduce a confinement mechanism in photonic crystal slab cavities, which relies on the superposition of two incommensurate one-dimensional lattices in a line-defect waveguide. It is shown that the resulting photonic profile realizes an effective quasi-periodic bichromatic potential for the electromagnetic field confinement yielding extremely high quality (Q) factor nanocavities, while simultaneously keeping the mode volume close to the diffraction limit. We apply these concepts to pillar- and hole-based photonic crystal slab cavities, respectively, and a Q-factor improvement by over an order of magnitude is shown over existing designs, especially in pillar-based structures. Thanks to the generality and easy adaptationmore » of such confinement mechanism to a broad class of cavity designs and photonic lattices, this work opens interesting routes for applications where enhanced light–matter interaction in photonic crystal structures is required.« less

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

PubMed

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

2013-12-01

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

Delivery of small molecules for bone regenerative engineering: preclinical studies and potential clinical applications

PubMed Central

Laurencin, Cato T.; Ashe, Keshia M.; Henry, Nicole; Kan, Ho Man; Lo, Kevin W-H.

2014-01-01

Stimulation of bone regeneration using growth factors is a promising approach for musculoskeletal regenerative engineering. Common limitations with protein growth factors are high manufacturing costs, protein instability, contamination issues, and unwanted immunogenic responses of the host. New strategies for bone regeneration that obviate these problems can have a significant impact on the treatment of skeletal injury and diseases. Over the past decade, a large number of small molecules with the potential of regenerating skeletal tissue have been reported in the literature. Here, we review this literature, paying specific attention to the prospects for small molecule-based bone-regenerative engineering. We also review the preclinical study of small molecules associated with bone regeneration. PMID:24508820

Evaluation of constricted affect in chronic pain: an attempt using the Toronto Alexythymia Scale.

PubMed

Millard, R W; Kinsler, B L

1992-09-01

The Toronto Alexythymia Scale (TAS) was applied as a potential measure of constricted affect among a sample of patients with chronic, non-malignant pain (n = 195). As previously demonstrated with non-clinical samples, the scale was found to possess moderate reliability with two principal internal factors. These factors seemed to reflect social introversion and a lack of proneness to fantasy. There was a moderate, negative association between them. The domain sampled by the TAS was apparently heterogeneous, with total scores showing no relationship to reported disability or pain intensity and a low relationship to reported distress. These results suggest potential limitations of the TAS and the alexythymia construct as means for evaluating constricted affect that accompanies chronic pain.

Macrobioerosion in Porites corals in subtropical northern South China Sea: a limiting factor for high-latitude reef framework development

NASA Astrophysics Data System (ADS)

Chen, Tianran; Li, Shu; Yu, Kefu

2013-03-01

Bioerosion is an important limiting factor in carbonate accretion and reef framework development; however, few studies have quantified the direct impact of macroborers on high-latitude coral communities, which are viewed as potential refuge during a period of global warming. In this study, internal macrobioerosion of Porites corals was examined at Daya Bay, subtropical northern South China Sea. The principal borers were the bivalve Lithophaga spp. and the sponges Cliona spp. and Cliothosa spp. (≥80 %), while sipunculid and polychaete worms and barnacles accounted for small amounts of bioerosion (≤20 %). Porites corals were heavily bioeroded in areas impacted by aquacultural and urban activities (10.34-27.55 %) compared with corals in relatively unpolluted areas (2.18-6.76 %). High levels of bioerosion, especially boring bivalve infestation, significantly weaken the corals and increase their susceptibility to dislodgement and fragmentation in typhoons, limiting accumulation of limestone framework. This study implies that carbonate accretion and reef development for high-latitude coral communities may be limited in future high-CO2 and eutrophication-stressed environments.

Piezoelectric scattering limited mobility of hybrid organic-inorganic perovskites CH3NH3PbI3

PubMed Central

Lu, Ying-Bo; Kong, Xianghua; Chen, Xiaobin; Cooke, David G.; Guo, Hong

2017-01-01

Carrier mobility is one of the most important parameters for semiconducting materials and their use in optoelectronic devices. Here we report a systematic first principles analysis of the acoustic phonon scattering mechanism that limits the mobility of CH3NH3PbI3 (MAPbI3) perovskites. Due to the unique hybrid organic-inorganic structure, the mechanical, electronic and transport properties are dominated by the same factor, i.e. the weak interatomic bond and the easy rotation of methylammonium (MA) molecules under strain. Both factors make MAPbI3 soft. Rotation of MA molecule induces a transverse shift between Pb and I atoms, resulting in a very low deformation potential and a strong piezoelectricity in MAPbI3. Hence the carrier mobility of pristine MAPbI3 is limited by the piezoelectric scattering, which is consistent to the form of its temperature dependence. Our calculations suggest that in the pristine limit, a high mobility of about several thousand cm2 V−1 S−1 is expected for MAPbI3. PMID:28150743

Global Characteristics of Childhood Acute Promyelocytic Leukemia

PubMed Central

Zhang, L; Samad, A; Pombo-de-Oliveira, MS; Scelo, G; Smith, MT; Feusner, J; Wiemels, JL; Metayer, C

2014-01-01

Acute promyelocytic leukemia (APL) comprises approximately 5–10% of childhood acute myeloid leukemia (AML) cases in the US. While variation in this percentage among other populations was noted previously, global patterns of childhood APL have not been thoroughly characterized. In this comprehensive review of childhood APL, we examined its geographic pattern and the potential contribution of environmental factors to observed variation. In 142 studies (spanning >60 countries) identified, variation was apparent—de novo APL represented from 2% (Switzerland) to >50% (Nicaragua) of childhood AML in different geographic regions. Because a limited number of previous studies addressed specific environmental exposures that potentially underlie childhood APL development, we gathered 28 childhood cases of therapy-related APL, which exemplified associations between prior exposures to chemotherapeutic drugs/radiation and APL diagnosis. Future population-based studies examining childhood APL patterns and the potential association with specific environmental exposures and other risk factors are needed. PMID:25445717

Designing Web-based GIS Application by CSF Method: A Case Study in Boven Digoel Papua

NASA Astrophysics Data System (ADS)

Letsoin, Hendrykus Saritangdan; JSantoso, Albertus Joko; Suyoto

2018-02-01

Since Boven Digoel Regency was established in 2003, to this day its infrastructures are very limited, the region is still not developed, Human Resources (SDM) and Information and Communication Technology are still manual. The development of Geographic Information System was expected to contribute to ICT development in Papua, particularly Boven Digoel Regency, in displaying data of existing local potentials, e.g. tourism, plantation and forestry. Critical Success Factor Method was the right method in considering factors determining the success of the implementation of a strategy, in good information management and in providing data of local potentials of geographic information system for people in Boven Digoel Regency and the people of Indonesia in general to introduce Boven Digoel Regency, Papua. Framework Laravel with PHP programming language was expected to support Geographic Information System well to determine the distribution of local potentials in Boven Digoel Regency‥

Fingerprinting of music scores

NASA Astrophysics Data System (ADS)

Irons, Jonathan; Schmucker, Martin

2004-06-01

Publishers of sheet music are generally reluctant in distributing their content via the Internet. Although online sheet music distribution's advantages are numerous the potential risk of Intellectual Property Rights (IPR) infringement, e.g. illegal online distributions, disables any innovation propensity. While active protection techniques only deter external risk factors, additional technology is necessary to adequately treat further risk factors. For several media types including music scores watermarking technology has been developed, which ebeds information in data by suitable data modifications. Furthermore, fingerprinting or perceptual hasing methods have been developed and are being applied especially for audio. These methods allow the identification of content without prior modifications. In this article we motivate the development of watermarking and fingerprinting technologies for sheet music. Outgoing from potential limitations of watermarking methods we explain why fingerprinting methods are important for sheet music and address potential applications. Finally we introduce a condept for fingerprinting of sheet music.

Work-Related Factors Considered by Sickness-Absent Employees When Estimating Timeframes for Returning to Work

PubMed Central

Choi, YoonSun

2016-01-01

Introduction Work-related factors have been found to be influential in shaping a number of return-to-work outcomes including return-to-work expectations. Based on the idea that work-related factors have the potential for modification through workplace-based initiatives, this study involved a detailed examination of work-related factors referenced by workers as being taken into consideration when estimating timeframes for returning to work. Methods Focus groups were conducted with 30 employees, currently off work (≤ 3 months) due to a musculoskeletal condition. During the focus groups, participants wrote and spoke about the factors that they considered when forming their expectations for returning to work. Data were subjected to thematic content analysis. Results Discussions revealed that participants’ considerations tended to differ depending on whether or not they had a job to return to. Those with jobs (n = 23) referenced specific influences such as working relationships, accommodations, physical and practical limitations, as well as concerns about their ability to do their job. Those without a job to return to (n = 7) talked about the ways they would go about finding work, and how long they thought this would take. Both groups mentioned the influence of wanting to find the “right” job, retraining and being limited due to the need for income. Conclusion Findings indicate that employees reference numerous work-related factors when estimating their timeframes for returning to work, and that many of these have been previously identified as relating to other return-to-work outcomes. Findings suggest the potential to improve return-to-work expectation through addressing work-related influences, and helping people work through the tasks they need to complete in order to move forward in the return-to-work process. PMID:27706194

Work-Related Factors Considered by Sickness-Absent Employees When Estimating Timeframes for Returning to Work.

PubMed

Young, Amanda E; Choi, YoonSun

2016-01-01

Work-related factors have been found to be influential in shaping a number of return-to-work outcomes including return-to-work expectations. Based on the idea that work-related factors have the potential for modification through workplace-based initiatives, this study involved a detailed examination of work-related factors referenced by workers as being taken into consideration when estimating timeframes for returning to work. Focus groups were conducted with 30 employees, currently off work (≤ 3 months) due to a musculoskeletal condition. During the focus groups, participants wrote and spoke about the factors that they considered when forming their expectations for returning to work. Data were subjected to thematic content analysis. Discussions revealed that participants' considerations tended to differ depending on whether or not they had a job to return to. Those with jobs (n = 23) referenced specific influences such as working relationships, accommodations, physical and practical limitations, as well as concerns about their ability to do their job. Those without a job to return to (n = 7) talked about the ways they would go about finding work, and how long they thought this would take. Both groups mentioned the influence of wanting to find the "right" job, retraining and being limited due to the need for income. Findings indicate that employees reference numerous work-related factors when estimating their timeframes for returning to work, and that many of these have been previously identified as relating to other return-to-work outcomes. Findings suggest the potential to improve return-to-work expectation through addressing work-related influences, and helping people work through the tasks they need to complete in order to move forward in the return-to-work process.

[Environmental factors and male fertility].

PubMed

Köhn, F-M; Schuppe, H C

2016-07-01

The identification of potential environmental hazards may have clinical relevance for diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders. Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproductive functions. With regard to the complex regulation of the male reproductive system, the available information concerning single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal studies remains difficult. Nevertheless, the assessment of relevant exposures to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.

Prevention of relapse in patients with congestive heart failure: the role of precipitating factors

PubMed Central

Feenstra, J; Grobbee, D; Jonkman, F; Hoes, A; Stricker, B

1998-01-01

Relapse of congestive heart failure (CHF) frequently occurs and has serious consequences in terms of morbidity, mortality, and health care expenditure. Many studies have investigated the aetiological and prognostic factors of CHF, but there are only limited data on the role of precipitating factors that trigger relapse of CHF. Knowledge of potential precipitating factors may help to optimise treatment and provide guidance for patients with CHF. The literature was reviewed to identify factors that may influence haemodynamic homeostasis in CHF. Precipitating factors that may offer opportunities for preventing relapse of CHF were selected. Potential precipitating factors are discussed in relation to the pathophysiology of CHF: alcohol, smoking, psychological stress, uncontrolled hypertension, cardiac arrhythmias, myocardial ischaemia, poor treatment compliance, and inappropriate medical treatment. Poor treatment compliance in particular is frequently encountered in patients with CHF. Furthermore, studies of medical treatment under everyday circumstances indicate that some aspects of the management of CHF can be improved. In conclusion, the identification of precipitating factors for relapse of CHF may strongly contribute to optimal treatment. Improvement of treatment compliance and optimalisation of medical treatment may offer important possibilities to clinicians to reduce the number of relapses in patients with CHF.

 Keywords: congestive heart failure;  precipitating factors;  prevention PMID:9930039

Vulnerability of larval lamprey to Columbia River hydropower system operations—effects of dewatering on larval lamprey movements and survival

USGS Publications Warehouse

Liedtke, Theresa L.; Weiland, Lisa K.; Mesa, Matthew G.

2015-08-27

Numbers of adult and juvenile Pacific lamprey ( Entosphenus tridentatus ) in the upper Columbia River Basin of the interior Pacific Northwest have decreased from historical levels (Close and others, 2002), raising concerns f rom State and Federal agencies and Tribal entities. In 1994, the U.S. Fish and Wildlife Service designated Pacific lamprey as a Category 2 candidate species and in 2003, the species was petitioned for listing under the Endangered Species Act. Listing consideration and potential recovery planning are significantly hindered by a lack of information on the basic biology and ecology of lampreys, including limiting factors. To date (2015), several factors that may limit lamprey production require study, including dam passage issues, contaminants, and effects on habitat.

Use of Anthropometry for the Prediction of Regional Body Tissue Distribution in Adults: Benefits and Limitations in Clinical Practice

PubMed Central

Scafoglieri, Aldo; Clarys, Jan Pieter; Cattrysse, Erik; Bautmans, Ivan

2014-01-01

Regional body composition changes with aging. Some of the changes in composition are considered major risk factors for developing obesity related chronic diseases which in turn may lead to increased mortality in adults. The role of anthropometry is well recognized in the screening, diagnosis and follow-up of adults for risk classification, regardless of age. Regional body composition is influenced by a number of intrinsic and extrinsic factors. Therapeutic measures recommended to lower cardiovascular disease risk include lifestyle changes. The aim of this review is to systematically summarize studies that assessed the relationships between anthropometry and regional body composition. The potential benefits and limitations of anthropometry for use in clinical practice are presented and suggestions for future research given. PMID:25489489

Groundwater availability as constrained by hydrogeology and environmental flows

USGS Publications Warehouse

Watson, Katelyn A.; Mayer, Alex S.; Reeves, Howard W.

2014-01-01

Groundwater pumping from aquifers in hydraulic connection with nearby streams has the potential to cause adverse impacts by decreasing flows to levels below those necessary to maintain aquatic ecosystems. The recent passage of the Great Lakes-St. Lawrence River Basin Water Resources Compact has brought attention to this issue in the Great Lakes region. In particular, the legislation requires the Great Lakes states to enact measures for limiting water withdrawals that can cause adverse ecosystem impacts. This study explores how both hydrogeologic and environmental flow limitations may constrain groundwater availability in the Great Lakes Basin. A methodology for calculating maximum allowable pumping rates is presented. Groundwater availability across the basin may be constrained by a combination of hydrogeologic yield and environmental flow limitations varying over both local and regional scales. The results are sensitive to factors such as pumping time, regional and local hydrogeology, streambed conductance, and streamflow depletion limits. Understanding how these restrictions constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions has important water resources policy and management implications.

Electrically-controlled near-field radiative thermal modulator made of graphene-coated silicon carbide plates

NASA Astrophysics Data System (ADS)

Yang, Yue; Wang, Liping

2017-08-01

In this work, we propose a hybrid near-field radiative thermal modulator made of two graphene-covered silicon carbide (SiC) plates separated by a nanometer vacuum gap. The near-field photon tunneling between the emitter and receiver is modulated by changing graphene chemical potentials with symmetrically or asymmetrically applied voltage biases. The radiative heat flux calculated from fluctuational electrodynamics significantly varies with graphene chemical potentials due to tunable near-field coupling strength between graphene plasmons across the vacuum gap. Thermal modulation and switching, which are the key functionalities required for a thermal modulator, are theoretically realized and analyzed. Newly introduced quantities of the modulation factor, the sensitivity factor and switching factor are studied quite extensively in a large parameter range for both graphene chemical potential and vacuum gap distance. This opto-electronic device with faster operating mode, which is in principle only limited by electronics and not by the thermal inertia, will facilitate the practical application of active thermal management, thermal circuits, and thermal computing with photon-based near-field thermal transport.

Elements and elasmobranchs: hypotheses, assumptions and limitations of elemental analysis.

PubMed

McMillan, M N; Izzo, C; Wade, B; Gillanders, B M

2017-02-01

Quantifying the elemental composition of elasmobranch calcified cartilage (hard parts) has the potential to answer a range of ecological and biological questions, at both the individual and population level. Few studies, however, have employed elemental analyses of elasmobranch hard parts. This paper provides an overview of the range of applications of elemental analysis in elasmobranchs, discussing the assumptions and potential limitations in cartilaginous fishes. It also reviews the available information on biotic and abiotic factors influencing patterns of elemental incorporation into hard parts of elasmobranchs and provides some comparative elemental assays and mapping in an attempt to fill knowledge gaps. Directions for future experimental research are highlighted to better understand fundamental elemental dynamics in elasmobranch hard parts. © 2016 The Fisheries Society of the British Isles.

Oxygen effects on senescence in chondrocytes and mesenchymal stem cells: consequences for tissue engineering.

PubMed

Moussavi-Harami, Farid; Duwayri, Yazan; Martin, James A; Moussavi-Harami, Farshid; Buckwalter, Joseph A

2004-01-01

Primary isolates of chondrocytes and mesenchymal stem cells are often insufficient for cell-based autologous grafting procedures, necessitating in vitro expansion of cell populations. However, the potential for expansion is limited by cellular senescence, a form of irreversible cell cycle arrest regulated by intrinsic and extrinsic factors. Intrinsic mechanisms common to most somatic cells enforce senescence at the so-called "Hayflick limit" of 60 population doublings. Termed "replicative senescence", this mechanism prevents cellular immortalization and suppresses oncogenesis. Although it is possible to overcome the Hayflick limit by genetically modifying cells, such manipulations are regarded as prohibitively dangerous in the context of tissue engineering. On the other hand, senescence associated with extrinsic factors, often called "stress-induced" senescence, can be avoided simply by modifying culture conditions. Because stress-induced senescence is "premature" in the sense that it can halt growth well before the Hayflick limit is reached, growth potential can be significantly enhanced by minimizing culture related stress. Standard culture techniques were originally developed to optimize the growth of fibroblasts but these conditions are inherently stressful to many other cell types. In particular, the 21% oxygen levels used in standard incubators, though well tolerated by fibroblasts, appear to induce oxidative stress in other cells. We reasoned that chondrocytes and MSCs, which are adapted to relatively low oxygen levels in vivo, might be sensitive to this form of stress. To test this hypothesis we compared the growth of MSC and chondrocyte strains in 21% and 5% oxygen. We found that incubation in 21% oxygen significantly attenuated growth and was associated with increased oxidant production. These findings indicated that sub-optimal standard culture conditions sharply limited the expansion of MSC and chondrocyte populations and suggest that cultures for grafting purposes should be maintained in a low-oxygen environment.

Oxygen Effects on Senescence in Chondrocytes and Mesenchymal Stem Cells: Consequences for Tissue Engineering

PubMed Central

Moussavi-Harami, Farid; Duwayri, Yazan; Martin, James A; Moussavi-Harami, Farshid; Buckwalter, Joseph A

2004-01-01

Primary isolates of chondrocytes and mesenchymal stem cells are often insufficient for cell-based autologous grafting procedures, necessitating in vitro expansion of cell populations. However, the potential for expansion is limited by cellular senescence, a form of irreversible cell cycle arrest regulated by intrinsic and extrinsic factors. Intrinsic mechanisms common to most somatic cells enforce senescence at the so-called "Hayflick limit" of 60 population doublings. Termed "replicative senescence", this mechanism prevents cellular immortalization and suppresses oncogenesis. Although it is possible to overcome the Hayflick limit by genetically modifying cells, such manipulations are regarded as prohibitively dangerous in the context of tissue engineering. On the other hand, senescence associated with extrinsic factors, often called "stress-induced" senescence, can be avoided simply by modifying culture conditions. Because stress-induced senescence is "premature" in the sense that it can halt growth well before the Hayflick limit is reached, growth potential can be significantly enhanced by minimizing culture related stress. Standard culture techniques were originally developed to optimize the growth of fibroblasts but these conditions are inherently stressful to many other cell types. In particular, the 21% oxygen levels used in standard incubators, though well tolerated by fibroblasts, appear to induce oxidative stress in other cells. We reasoned that chondrocytes and MSCs, which are adapted to relatively low oxygen levels in vivo, might be sensitive to this form of stress. To test this hypothesis we compared the growth of MSC and chondrocyte strains in 21% and 5% oxygen. We found that incubation in 21% oxygen significantly attenuated growth and was associated with increased oxidant production. These findings indicated that sub-optimal standard culture conditions sharply limited the expansion of MSC and chondrocyte populations and suggest that cultures for grafting purposes should be maintained in a low-oxygen environment. PMID:15296200

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion.

PubMed

Gorin, Caroline; Rochefort, Gael Y; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Muller, Laurent; Chaussain, Catherine; Germain, Stéphane

2016-03-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. ©AlphaMed Press.

Genetic improvement of leaf photosynthesis and intrinsic water use efficiency in C3 plants: Why so much little success?

PubMed

Flexas, J

2016-10-01

There is an urgent need for simultaneously increasing photosynthesis/yields and water use efficiency (WUE) in C3 crops. Potentially, this can be achieved by genetic manipulation of the key traits involved. However, despite significant efforts in the past two decades very limited success has been achieved. Here I argue that this is mostly due to the fact that single gene/single trait approaches have been used thus far. Photosynthesis models demonstrate that only limited improving of photosynthesis can be expected by large improvements of any of its single limiting factors, i.e. stomatal conductance, mesophyll conductance, and the biochemical capacity for photosynthesis, the latter co-limited by Rubisco and the orchestrated activity of thylakoid electron transport and the Calvin cycle enzymes. Accordingly, only limited improvements of photosynthesis have been obtained by genetic manipulation of any of these single factors. In addition, improving photosynthesis by genetic manipulation in general reduced WUE, and vice-versa, and in many cases pleiotropic effects appear that cancel out some of the expected benefits. I propose that success in genetic manipulation for simultaneous improvement of photosynthesis and WUE efficiency may take longer than suggested in previous reports, and that it can be achieved only by joint projects addressing multi-gene manipulation for simultaneous alterations of all the limiting factors of photosynthesis, including the often neglected phloem capacity for loading and transport the expected surplus of carbohydrates in plants with improved photosynthesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

What Affects Academic Functioning in Secondary Special Education Students with Serious Emotional and/or Behavioral Problems?

ERIC Educational Resources Information Center

Mattison, Richard E.; Blader, Joseph C.

2013-01-01

Concern is growing over the limited academic progress in special education students with emotional and/or behavioral disorders (EBD). We know little about how academic and behavioral factors interact in these students to affect their academic functioning. Therefore, potential associations were investigated over the course of one school year for…

Reactions to Dating Violence among Latino Teenagers: An Experiment Utilizing the Articulated Thoughts in Simulated Situations Paradigm

ERIC Educational Resources Information Center

Rayburn, Nadine Recker; Jaycox, Lisa H.; McCaffrey, Daniel F.; Ulloa, Emilio C.; Zander-Cotugno, Megan; Marshall, Grant N.; Shelley, Gene A.

2007-01-01

Dating violence is a serious problem among adolescents and young adults. Understanding teens' reactions to dating violence offers the potential to understand the factors that lead to perpetration of violent behavior and to elucidate prevention strategies. Knowledge concerning youth attitudes about dating violence is limited, and has largely come…

Personality Measurement with Mentally Retarded and Other Sub-Cultural Adults. Final Report.

ERIC Educational Resources Information Center

Eber, Herbert W.

Two 160-item experimental forms of multidimensional personality test to assess vocational potential of clients of limited literacy (third grade reading level) were developed and administered to clients at rehabilitation centers and at centers for the retarded. Using the 16 Personality Factors Test as a model, items were constructed to do the…

Induction of Rhizopus oryzae germination under starvation using host metabolites increases spore susceptibility to heat stress

USDA-ARS?s Scientific Manuscript database

Sweet potato is a nutritional source worldwide. Soft rot caused by Rhizopus spp. is a major limiting factor in the storage of produce, rendering it potentially unsafe for human consumption. In this study, Rhizopus oryzae was used to develop a concept of postharvest disease control by weakening the p...

Exploring flight crew behaviour

NASA Technical Reports Server (NTRS)

Helmreich, R. L.

1987-01-01

A programme of research into the determinants of flight crew performance in commercial and military aviation is described, along with limitations and advantages associated with the conduct of research in such settings. Preliminary results indicate significant relationships among personality factors, attitudes regarding flight operations, and crew performance. The potential theoretical and applied utility of the research and directions for further research are discussed.

Exploring flightcrew behaviour

NASA Technical Reports Server (NTRS)

Helmreich, Robert L.

1987-01-01

A program of research into the determinants of flightcrew performance in commercial and military aviation is described, along with limitations and advantages associated with the conduct of research in such settings. Preliminary results indicate significant relationships among personality factors, attitudes regarding flight operations, and crew performance. The potential theoretical and applied utility of the research and directions for further research are discussed.

Seasonal survival estimation for a long-distance migratory bird and the influence of winter precipitation

Treesearch

Sarah M. Rockwell; Joseph M. Wunderle; T. Scott Sillett; Carol I. Bocetti; David N. Ewert; Dave Currie; Jennifer D. White; Peter P. Marra

2017-01-01

Conservation of migratory animals requires information about seasonal survival rates. Identifying factors that limit populations, and the portions of the annual cycle in which they occur, are critical for recognizing and reducing potential threats. However, such data are lacking for virtually all migratory taxa. We investigated patterns and environmental correlates of...

40 CFR 265.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... stored or treated, and corrosion protection so that it will not collapse, rupture, or fail. The owner or... tank system is or will be in contact with the soil or with water, a determination by a corrosion expert of: (i) Factors affecting the potential for corrosion, including but not limited to: (A) Soil...

40 CFR 264.192 - Design and installation of new tank systems or components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... structural strength, compatibility with the waste(s) to be stored or treated, and corrosion protection to... component of the tank system will be in contact with the soil or with water, a determination by a corrosion expert of: (i) Factors affecting the potential for corrosion, including but not limited to: (A) Soil...

Counseling Sexual Assault Victims Who Become Pregnant after the Assault: Benefits and Limitations of First-Trimester Paternity Determination.

ERIC Educational Resources Information Center

Shulman, Lee P.; And Others

1992-01-01

Describes a patient with a history of infertility who, after becoming pregnant following a sexual assault, used chorionic villus sampling and DNA studies for paternity identification. Discusses risks and potential problems that accompany prenatal paternity testing. Ethical, moral, emotional, and religious factors should be considered in the…

Modifying climate change habitat models using tree species-specific assessments of model uncertainty and life history-factors

Treesearch

Stephen N. Matthews; Louis R. Iverson; Anantha M. Prasad; Matthew P. Peters; Paul G. Rodewald

2011-01-01

Species distribution models (SDMs) to evaluate trees' potential responses to climate change are essential for developing appropriate forest management strategies. However, there is a great need to better understand these models' limitations and evaluate their uncertainties. We have previously developed statistical models of suitable habitat, based on both...

Properties of cellulose micro/nanofibers obtained from eucalyptus pulp fiber treated with anaerobic digestate and high shear mixing

USDA-ARS?s Scientific Manuscript database

High production costs remain the single greatest factor limiting wider use of cellulose micro/nanofibers in the industry. The objective of the present study was to investigate the potential of using a low-cost bacteria-rich digestate (liquid anaerobic digestate – AD supernatant) on milled eucalyptus...

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion

PubMed Central

Gorin, Caroline; Rochefort, Gael Y.; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Germain, Stéphane

2016-01-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. Significance The results from the present study show that fibroblast growth factor-2 (FGF-2) priming is more efficient than hypoxia at increasing dental pulp stem cells derived from deciduous teeth (SHED)-induced vascularization compared with nonprimed controls. Together, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both hepatocyte growth factor and vascular endothelial growth factor. PMID:26798059

Open-Circuit Voltage Deficit, Radiative Sub-Bandgap States, and Prospects in Quantum Dot Solar Cells

PubMed Central

Chuang, Chia-Hao Marcus; Maurano, Andrea; Brandt, Riley E.; Hwang, Gyu Weon; Jean, Joel; Buonassisi, Tonio; Bulović, Vladimir; Bawendi, Moungi G.

2016-01-01

Quantum dot photovoltaics (QDPV) offer the potential for low-cost solar cells. To develop strategies for continued improvement in QDPVs, a better understanding of the factors that limit their performance is essential. Here, we study carrier recombination processes that limit the power conversion efficiency of PbS QDPVs. We demonstrate the presence of radiative sub-bandgap states and sub-bandgap state filling in operating devices by using photoluminescence (PL) and electroluminescence (EL) spectroscopy. These sub-bandgap states are most likely the origin of the high open-circuit-voltage (VOC) deficit and relatively limited carrier collection that have thus far been observed in QDPVs. Combining these results with our perspectives on recent progress in QDPV, we conclude that eliminating sub-bandgap states in PbS QD films has the potential to show a greater gain than may be attainable by optimization of interfaces between QDs and other materials. We suggest possible future directions that could guide the design of high-performance QDPVs. PMID:25927871

Performance-Based Versus Patient-Reported Physical Function: What Are the Underlying Predictors?

PubMed Central

Ölveczky, Daniele D.; Kiely, Dan K.; LaRose, Sharon I.; Jette, Alan M.

2011-01-01

Background Functional limitations have been operationally defined for studies of rehabilitation science through measures of physical performance and patient-reported function. Although conceived as representing similar concepts, differences between these 2 modes of measuring physical functioning have not been adequately characterized scientifically. Objective The purpose of this study was to compare the Short Physical Performance Battery (SPPB) with the function component of the Late-Life Function and Disability Instrument (LLFDI) with respect to their association with physiologic factors and other psychosocial and health factors potentially influencing rehabilitative care. Design This study was a cross-sectional analysis of baseline data from a sample of community-dwelling older adults (N=137) with mobility limitations enrolled in a randomized controlled trial of exercise. Methods A performance-based measure of function (the SPPB) and a self-report measure of function (the LLFDI) served as functional outcomes. Physiologic factors included measures of leg strength, leg velocity, and exercise tolerance test (ETT) duration, which served as a surrogate measure of aerobic capacity. Psychosocial and health factors included age, sex, height, body mass index, number of chronic conditions, depression, and falls efficacy. Results Separate multivariable regression models predicting SPPB and LLFDI scores described 33% and 42% of the variance in each outcome (R2), respectively. Leg velocity and ETT duration were positively associated with both performance-based and patient-reported functional measures. Leg strength and age were positively associated with SPPB scores, whereas number of chronic conditions, sex, and falls efficacy were associated with the LLFDI scores. Limitations This study included older adults with mobility limitations and may not generalize to other populations. Conclusions Performance-based and patient-reported measures of physical function appear to assess different aspects of an older person's functioning. The SPPB was associated with age and physiologic factors, whereas patient-reported function measured by the LLFDI was associated with these factors as well as with psychosocial and health factors. PMID:22003163

Physics of Limiting Phenomena in Superconducting Microwave Resonators: Vortex Dissipation, Ultimate Quench and Quality Factor Degradation Mechanisms

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

Checchin, Mattia

Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described inmore » detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the superheating field, which is intimately correlated to the penetration of magnetic flux vortices in the material. Experimental data for N-doped cavities suggest that uniform Ginzburg-Landau parameter cavities are statistically limited by the lower critical field, in terms of accelerating gradient. By introducing a Ginzburg-Landau parameter profile at the cavity rf surface--dirty layer--the accelerating gradient of superconducting resonators can be enhanced. The description of the physics behind the accelerating gradient enhancement as a consequence of the dirty layer is carried out by solving numerically the Ginzburg-Landau equations for the layered system. The enhancement is showed to be promoted by the higher energy barrier to vortex penetration, and by the enhanced lower critical field. Another serious threat to the quality factor during the cavity operation is the extra dissipation introduced by the quench. Such quality factor degradation mechanism due to the quench, is generated by the trapping of external magnetic flux at quench spot. The purely extrinsic origin of such extra dissipation is proven by the impossibility of decrease the quality factor by quenching in a magnetic field-free environment. Also, a clear relation of the dissipation introduced by quenching to the orientation of the applied magnetic field is observed. The full recover of the quality factor by re-quenching in compensated field is possible when the trapped flux at the quench spot is modest. On the contrary, when the trapped magnetic flux is too large, the quality factor degradation may become irreversible by this technique, likely due to the outward flux migration beyond the normal zone opening during the quench.« less

Physics of limiting phenomena in superconducting microwave resonators: Vortex dissipation, ultimate quench and quality factor degradation mechanisms

NASA Astrophysics Data System (ADS)

Checchin, Mattia

Superconducting niobium accelerating cavities are devices operating in radiofrequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associated to the superheating field, which is intimately correlated to the penetration of magnetic flux vortices in the material. Experimental data for N-doped cavities suggest that uniform Ginzburg-Landau parameter cavities are statistically limited by the lower critical field, in terms of accelerating gradient. By introducing a Ginzburg-Landau parameter profile at the cavity rf surface--dirty layer--the accelerating gradient of superconducting resonators can be enhanced. The description of the physics behind the accelerating gradient enhancement as a consequence of the dirty layer is carried out by solving numerically the Ginzburg-Landau equations for the layered system. The enhancement is showed to be promoted by the higher energy barrier to vortex penetration, and by the enhanced lower critical field. Another serious threat to the quality factor during the cavity operation is the extra dissipation introduced by the quench. Such quality factor degradation mechanism due to the quench, is generated by the trapping of external magnetic flux at the quench spot. The purely extrinsic origin of such extra dissipation is proven by the impossibility of decrease the quality factor by quenching in a magnetic field-free environment. Also, a clear relation of the dissipation introduced by quenching to the orientation of the applied magnetic field is observed. The full recover of the quality factor by re-quenching in compensated field is possible when the trapped flux at the quench spot is modest. On the contrary, when the trapped magnetic flux is too large, the quality factor degradation may become irreversible by this technique, likely due to the outward flux migration beyond the normal zone opening during the quench.

Effect of Trapped Ions on Shielding and Floating Potential of a Dust Grain in a Plasma

NASA Astrophysics Data System (ADS)

Lampe, Martin; Ganguli, Gurudas; Joyce, Glenn; Gavrishchaka, Valeriy

2001-10-01

The problem of electrostatic shielding around a small spherical collector immersed in plasma, and the related problem of electron and ion flow to the collector, date to the origins of plasma physics. Beginning with Mott-Smith and Langmuir (1926), calculations have typically neglected collisions, on the grounds that the mean free path is long compared to shielding length scales, i.e. the Debye length. However, investigators beginning with Bernstein and Rabinowitz (1959) have known that negative-energy trapped ions, created by occasional collisions, might be important. We present an analytic calculation of the density of trapped and untrapped ions, self-consistent with the potential. Under typical conditions for dust grains immersed in a discharge plasma, trapped ions dominate the shielding cloud in steady state, even in the limit of very long mean free path. As a result the shielded potential is different from the results of orbital motion limited theory. Collisions also greatly increase the ion current to the collector, thereby decreasing the floating potential and the grain charge by a factor as large as two to three.

Competition between autotrophic and heterotrophic microbial plankton for inorganic nutrients induced by variability in estuarine biophysicochemical conditions

NASA Astrophysics Data System (ADS)

Williams, A.; Quigg, A.

2016-02-01

Competition for inorganic nutrients between autotrophic and heterotrophic fractions of microbial plankton (0.2-20μm) was investigated at two stations in a sub-tropical estuary, Galveston Bay, Texas. Competition potential between these groups is enhanced because individuals are similar in size, reducing variability among their nutrient uptake efficiencies. Further, in estuaries, allochthonous supplements to autochthonous carbon may satisfy heterotrophic requirements, allowing alternative factors to limit abundance. The relative abundance of autotrophs and heterotrophs stained with SYBR Green I and enumerated on a Beckman Coulter Gallios flow cytometer were evaluated monthly during a year-long study. Shifts in the relative in situ abundance were significantly related to temperature, dissolved inorganic nitrogen (DIN), phosphorous (Pi), and total organic carbon (TOC) concentrations revealing opposing gradients of limitation by different abiotic factors. In corresponding in vitro nutrient enrichment bioassays the relative contribution of autotrophic or heterotrophic microbial plankton to significant enrichment responses varied. Only during macro- (>20μm) phytoplankton blooms do autotrophic microbial plankton respond to nutrient enrichment. Contrastingly, the heterotrophic microbial plankton responded to nutrient enrichment primarily when temperature limitation was alleviated. Therefore, the potential for autotrophic and heterotrophic microbial plankton competition for limiting nutrients is highest when autotrophic microbial plankton are also competing with larger phytoplankton during bloom events. Based on this evidence, we hypothesize that the autotrophic microbial fraction has a competitive advantage over the heterotrophs for inorganic nutrients in Galveston Bay. The observed microbial competition during estuarine phytoplankton blooms may have important consequences on biogeochemical processes including carbon and nutrient cycling.

[Limiting factors in the class III camouflage treatment: a potential protocol].

PubMed

Chaques Asensi, José

2016-06-01

The Class III skeletal malocclusion has been traditionally treated with a combined approach of orthodontics and orthognathic surgery or with a strategy of orthodontic camouflage. Some severe cases can be identified as ideal candidates for a surgical treatment whereas some others can be handled with orthodontics alone, with a reasonable expectation of an acceptable result. However, the problem remains for the borderline patient. In fact, limited information is available in the literature regarding the identification of the factors that can help in establishing the limits for one treatment modality or the other. Furthermore, the quantification of some of these factors, for practical purposes, is practically missing or very seldom suggested. Therefore, the decision making process remains a subjective reflection based on the "good clinical sense" of the orthodontist or just reduced to an "educated guess". In order to add some information, hopefully useful in deciding the most suitable treatment option for the individual patient, we propose a clinical protocol based on four different factors. Namely: the skeletal discrepancy, the occlusal discrepancy, the periodontal condition and facial aesthetics. For each one of these factors several parameters will be evaluated and, for some of them, an attempt to provide some reference numerical values will be made. Finally, clinical examples will be presented to illustrate the concepts discussed and the treatment alternatives, final treatment plan and treatment outcome will be analyzed for each one of them. © EDP Sciences, SFODF, 2016.

Polycystic ovary syndrome and adverse pregnancy outcomes: Current state of knowledge, challenges and potential implications for practice.

PubMed

Bahri Khomami, Mahnaz; Boyle, Jacqueline A; Tay, Chau T; Vanky, Eszter; Teede, Helena J; Joham, Anju E; Moran, Lisa J

2018-06-01

Although there is a growing body of literature reporting that pregnancies in women with polycystic ovary syndrome (PCOS) are associated with greater complications than those without PCOS, methodological differences across studies make these results difficult to consolidate. This narrative review outlines potential mechanisms involved in adverse pregnancy outcomes in PCOS and the nature of the complications. It covers limitations of current evidence and future research directions. Future research should include prospective studies with phenotypic stratification of PCOS and matching or consideration of specific PCOS manifestations and risk factors specific to each pregnancy complication. This review also emphasizes the importance of following a healthy lifestyle for women with PCOS and of individualized care according to overall risk factors for pregnancy complications. © 2018 John Wiley & Sons Ltd.

Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site

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

Truex, Michael J.; Lee, Brady D.; Johnson, Christian D.

The fate and transport of 129I in the environment and potential remediation technologies are currently being studied as part of environmental remediation activities at the Hanford Site. A conceptual model describing the nature and extent of subsurface contamination, factors that control plume behavior, and factors relevant to potential remediation processes is needed to support environmental remedy decisions. Because 129I is an uncommon contaminant, relevant remediation experience and scientific literature are limited. Thus, the conceptual model also needs to both describe known contaminant and biogeochemical process information and to identify aspects about which additional information needed to effectively support remedy decisions.more » this document summarizes the conceptual model of iodine behavior relevant to iodine in the subsurface environment at the Hanford site.« less

Risk factors for, and prevention of, shoulder injuries in overhead sports: a systematic review with best-evidence synthesis.

PubMed

Asker, Martin; Brooke, Hannah L; Waldén, Markus; Tranaeus, Ulrika; Johansson, Fredrik; Skillgate, Eva; Holm, Lena W

2018-03-26

To assess the evidence for risk factors and prevention measures for shoulder injuries in overhead sports. Systematic review with best-evidence synthesis. Medline (Ovid), PubMed (complementary search), Embase (Elsevier), Cochrane (Wiley), SPORTDiscus (Ebsco) and Web of Science Core Collection (Thomson Reuters), from 1 January 1990 to 15 May 2017. Randomised controlled trials, cohort studies and case-control studies on risk factors or prevention measures for shoulder injuries in overhead sports. The eligible studies were quality assessed using the Scottish Intercollegiate Guidelines Network criteria. Of 4778 studies identified, 38 were eligible for quality review and 17 met the quality criteria to be included in the evidence synthesis. One additional quality study presented a shoulder injury prevention programme. Most studies focused on baseball, lacrosse or volleyball (n=13). The risk factors examined included participation level (competition vs training) (n=10), sex (n=4), biomechanics (n=2) and external workload (n=2). The evidence for all risk factors was limited or conflicting. The effect of the prevention programme within the subgroup of uninjured players at baseline was modest and possibly lacked statistical power. All investigated potential risk factors for shoulder injury in overhead sports had limited evidence, and most were non-modifiable (eg, sex). There is also limited evidence for the effect of shoulder injury prevention measures in overhead sports. CRD42015026850. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Ground-based adaptive optics coronagraphic performance under closed-loop predictive control

NASA Astrophysics Data System (ADS)

Males, Jared R.; Guyon, Olivier

2018-01-01

The discovery of the exoplanet Proxima b highlights the potential for the coming generation of giant segmented mirror telescopes (GSMTs) to characterize terrestrial-potentially habitable-planets orbiting nearby stars with direct imaging. This will require continued development and implementation of optimized adaptive optics systems feeding coronagraphs on the GSMTs. Such development should proceed with an understanding of the fundamental limits imposed by atmospheric turbulence. Here, we seek to address this question with a semianalytic framework for calculating the postcoronagraph contrast in a closed-loop adaptive optics system. We do this starting with the temporal power spectra of the Fourier basis calculated assuming frozen flow turbulence, and then apply closed-loop transfer functions. We include the benefits of a simple predictive controller, which we show could provide over a factor of 1400 gain in raw point spread function contrast at 1 λ/D on bright stars, and more than a factor of 30 gain on an I=7.5 mag star such as Proxima. More sophisticated predictive control can be expected to improve this even further. Assuming a photon-noise limited observing technique such as high-dispersion coronagraphy, these gains in raw contrast will decrease integration times by the same large factors. Predictive control of atmospheric turbulence should therefore be seen as one of the key technologies that will enable ground-based telescopes to characterize terrestrial planets.

Anti-inflammatory drugs for Duchenne muscular dystrophy: focus on skeletal muscle-releasing factors.

PubMed

Miyatake, Shouta; Shimizu-Motohashi, Yuko; Takeda, Shin'ichi; Aoki, Yoshitsugu

2016-01-01

Duchenne muscular dystrophy (DMD), an incurable and a progressive muscle wasting disease, is caused by the absence of dystrophin protein, leading to recurrent muscle fiber damage during contraction. The inflammatory response to fiber damage is a compelling candidate mechanism for disease exacerbation. The only established pharmacological treatment for DMD is corticosteroids to suppress muscle inflammation, however this treatment is limited by its insufficient therapeutic efficacy and considerable side effects. Recent reports show the therapeutic potential of inhibiting or enhancing pro- or anti-inflammatory factors released from DMD skeletal muscles, resulting in significant recovery from muscle atrophy and dysfunction. We discuss and review the recent findings of DMD inflammation and opportunities for drug development targeting specific releasing factors from skeletal muscles. It has been speculated that nonsteroidal anti-inflammatory drugs targeting specific inflammatory factors are more effective and have less side effects for DMD compared with steroidal drugs. For example, calcium channels, reactive oxygen species, and nuclear factor-κB signaling factors are the most promising targets as master regulators of inflammatory response in DMD skeletal muscles. If they are combined with an oligonucleotide-based exon skipping therapy to restore dystrophin expression, the anti-inflammatory drug therapies may address the present therapeutic limitation of low efficiency for DMD.

Anti-inflammatory drugs for Duchenne muscular dystrophy: focus on skeletal muscle-releasing factors

PubMed Central

Miyatake, Shouta; Shimizu-Motohashi, Yuko; Takeda, Shin’ichi; Aoki, Yoshitsugu

2016-01-01

Duchenne muscular dystrophy (DMD), an incurable and a progressive muscle wasting disease, is caused by the absence of dystrophin protein, leading to recurrent muscle fiber damage during contraction. The inflammatory response to fiber damage is a compelling candidate mechanism for disease exacerbation. The only established pharmacological treatment for DMD is corticosteroids to suppress muscle inflammation, however this treatment is limited by its insufficient therapeutic efficacy and considerable side effects. Recent reports show the therapeutic potential of inhibiting or enhancing pro- or anti-inflammatory factors released from DMD skeletal muscles, resulting in significant recovery from muscle atrophy and dysfunction. We discuss and review the recent findings of DMD inflammation and opportunities for drug development targeting specific releasing factors from skeletal muscles. It has been speculated that nonsteroidal anti-inflammatory drugs targeting specific inflammatory factors are more effective and have less side effects for DMD compared with steroidal drugs. For example, calcium channels, reactive oxygen species, and nuclear factor-κB signaling factors are the most promising targets as master regulators of inflammatory response in DMD skeletal muscles. If they are combined with an oligonucleotide-based exon skipping therapy to restore dystrophin expression, the anti-inflammatory drug therapies may address the present therapeutic limitation of low efficiency for DMD. PMID:27621596

Garnering Civic Hope: Social Studies, Expectations, and the Lost Civic Potential of Immigrant Youth

PubMed Central

Callahan, Rebecca M.; Obenchain, Kathryn M.

2016-01-01

Social studies education is designed to provide a foundation for civic society. In this study we consider immigrant optimism theory within the context of U.S. secondary social studies to examine the civic potential of immigrant youth. Using a mixed-methods approach, we complement analyses of teacher and immigrant young adult interviews with national survey data to explore how adults’ expectations shape immigrant youths’ civic identity formation. Although immigrant parents consistently express high academic expectations of their children, teachers’ civic expectations emerged as a critical factor in immigrant youths’ civic development. While teachers and immigrant youth reported rich civic discourse in advanced social studies classes, we counter that limited social studies course taking may restrict exposure to teachers’ civic expectations, and result in the unrealized civic potential of immigrant youth. We close with a cautionary note regarding the limits of social studies to develop a transformative, emancipatory citizenry, especially among the increasingly diverse immigrant youth population. PMID:27065504

Kaon condensation in dense matter

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

Carlson, J.; Heiselberg, H.; Pandharipande, V. R.

The kaon energy in neutron matter is calculated analytically with the Klein-Gordon equation, by making a Wigner-Seitz cell approximation and employing a K{sup -}N square well potential. The transition from the low density Lenz potential, proportional to scattering length, to the high density Hartree potential is found to begin at fairly low densities. Exact nonrelativistic calculations of the kaon energy in a simple cubic crystal of neutrons are used to test the Wigner-Seitz and the Ericson-Ericson approximation methods. In this case the frequently used Erickson-Erickson approximation is found to be fairly accurate up to twice nuclear matter density. All themore » calculations indicate that by {approx}4 times nuclear matter density the Hartree limit is reached. We also show that in the Hartree limit the energy of zero momentum kaons does not have relativistic energy dependent factors present in the low density expansions. The results indicate that the density for kaon condensation is higher than previously estimated.« less

Garnering Civic Hope: Social Studies, Expectations, and the Lost Civic Potential of Immigrant Youth.

PubMed

Callahan, Rebecca M; Obenchain, Kathryn M

Social studies education is designed to provide a foundation for civic society. In this study we consider immigrant optimism theory within the context of U.S. secondary social studies to examine the civic potential of immigrant youth. Using a mixed-methods approach, we complement analyses of teacher and immigrant young adult interviews with national survey data to explore how adults' expectations shape immigrant youths' civic identity formation. Although immigrant parents consistently express high academic expectations of their children, teachers' civic expectations emerged as a critical factor in immigrant youths' civic development. While teachers and immigrant youth reported rich civic discourse in advanced social studies classes, we counter that limited social studies course taking may restrict exposure to teachers' civic expectations, and result in the unrealized civic potential of immigrant youth. We close with a cautionary note regarding the limits of social studies to develop a transformative, emancipatory citizenry, especially among the increasingly diverse immigrant youth population.

Estimates of RF-induced erosion at antenna-connected beryllium plasma-facing components in JET

DOE PAGES

Klepper, C. C.; Borodin, D.; Groth, M.; ...

2016-01-18

Radio-frequency (RF)-enhanced surface erosion of beryllium (Be) plasma-facing components is explored, for the first time, using the ERO code. We applied the code in order to measure the RF-enhanced edge Be line emission at JET Be outboard limiters, in the presence of high-power, ion cyclotronresonance heating (ICRH) in L-mode discharges. In this first modelling study, the RF sheath effect from an ICRH antenna on a magnetically connected, limiter region is simulated by adding a constant potential to the local sheath, in an attempt to match measured increases in local Be I and Be II emission of factors of 2 3.more » It was found that such increases are readily simulated with added potentials in the range of 100 200 V, which is compatible with expected values for potentials arising from rectification of sheath voltage oscillations from ICRH antennas in the scrape-off layer plasma. We also estimated absolute erosion values within the uncertainties in local plasma conditions.« less

Limited interface between physiotherapy primary care and people with severe mental illness: a qualitative study.

PubMed

Lee, Samantha; Waters, Flavie; Briffa, Kathy; Fary, Robyn E

2017-07-01

How do mental health professionals perceive the role of physiotherapists in the care of people with severe and persistent mental illness, and what factors do they perceive as influencing access to physiotherapy services? How do people with severe and persistent mental illness understand the potential role of physiotherapy in their healthcare, and what factors do they perceive as influencing access to physiotherapy services? Qualitative study. Twenty-four mental health professionals and 35 people with severe and persistent mental illness. Interview schedules were developed to explore participants' understanding of physiotherapy, as well as barriers and enablers to service access. Focus groups and interviews were conducted for each group of participants. Transcripts were analysed using an inductive approach to derive key themes. Both the mental health professionals and the people with severe and persistent mental illness expressed a limited understanding of the role and relevance of physiotherapy for physical health in mental healthcare. Common barriers to service access were cost, transport and lack of motivation. Likewise, enablers of reduced cost, provision of transport and education about physiotherapy to improve their understanding were identified. The health system structure and perceived lack of mental health knowledge by physiotherapists influenced referrals from mental health professionals. Consequently, education in mental health for physiotherapists and integration of the service within mental health were identified as potential enablers to physiotherapy access. Limited understanding about physiotherapy and its relevance to physical health in mental healthcare among mental health professionals and people with severe and persistent mental illness was found to be a key factor influencing service access. Limited physiotherapy presence and advocacy within mental health were also highlighted. There is a need for greater understanding about physiotherapy among stakeholders, and for physiotherapists to be well equipped with skills and knowledge in mental health to facilitate greater involvement. [Lee S, Waters F, Briffa K, Fary RE (2017) Limited interface between physiotherapy primary care and people with severe mental illness: a qualitative study. Journal of Physiotherapy 63: 168-174]. Copyright © 2017. Published by Elsevier B.V.

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

NASA Astrophysics Data System (ADS)

Schuback, Nina; Flecken, Mirkko; Maldonado, Maria T.; Tortell, Philippe D.

2016-02-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at an unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in reaction center II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5-fold changes in the conversion factor between ETRRCII and carbon fixation (Kc / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light and correlates with the increased expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and Kc / nPSII requires further validation but has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

Does consideration of larger study areas yield more accurate estimates of air pollution health effects? An illustration of the bias-variance trade-off in air pollution epidemiology.

PubMed

Pedersen, Marie; Siroux, Valérie; Pin, Isabelle; Charles, Marie Aline; Forhan, Anne; Hulin, Agnés; Galineau, Julien; Lepeule, Johanna; Giorgis-Allemand, Lise; Sunyer, Jordi; Annesi-Maesano, Isabella; Slama, Rémy

2013-10-01

Spatially-resolved air pollution models can be developed in large areas. The resulting increased exposure contrasts and population size offer opportunities to better characterize the effect of atmospheric pollutants on respiratory health. However the heterogeneity of these areas may also enhance the potential for confounding. We aimed to discuss some analytical approaches to handle this trade-off. We modeled NO2 and PM10 concentrations at the home addresses of 1082 pregnant mothers from EDEN cohort living in and around urban areas, using ADMS dispersion model. Simulations were performed to identify the best strategy to limit confounding by unmeasured factors varying with area type. We examined the relation between modeled concentrations and respiratory health in infants using regression models with and without adjustment or interaction terms with area type. Simulations indicated that adjustment for area limited the bias due to unmeasured confounders varying with area at the costs of a slight decrease in statistical power. In our cohort, rural and urban areas differed for air pollution levels and for many factors associated with respiratory health and exposure. Area tended to modify effect measures of air pollution on respiratory health. Increasing the size of the study area also increases the potential for residual confounding. Our simulations suggest that adjusting for type of area is a good option to limit residual confounding due to area-associated factors without restricting the area size. Other statistical approaches developed in the field of spatial epidemiology are an alternative to control for poorly-measured spatially-varying confounders. © 2013 Elsevier Ltd. All rights reserved.

Shifting Environmental Ranges and Biome Potential According to the Whittaker Relationship

NASA Astrophysics Data System (ADS)

de Jong, R.; Garonna, I.; Schaepman, M. E.

2015-12-01

Robert H. Whittaker classified biome types mainly as a function of Mean Annual Temperature (MAT) and Mean Annual Precipitation (MAP), resulting in the well-known Whittaker plot1. This relationship is still being used to map biomes globally2. The same inputs (MAT and MAP), augmented with a radiation proxy, are used in the resource-balance perspective for modeling large-scale vegetation productivity as a function of abiotic factors3. These two approaches, used in a temporally dynamic manner, provided us indicators of shifts in growth-limiting factors4 and associated environmental ranges of vegetation, which, in turn, are key indicators for the study of global change and biodiversity5. We present a study in which we used the Whittaker relationship and CRU TS 3.22 climatic data to map regions that showed variable biome potential. These regions are likely to indicate ecotones - i.e. interactions zones between biomes - that have been subject to abiotic change and where a change in the vegetation system can be anticipated. At the same time, we used remotely sensed data (GIMMS v3g 1982-2012) to study gradients in vegetation dynamics in these zones. Preliminary results show strongest environmental shifts in northern ecotones, e.g. on the tundra - boreal boundary, and associated changes in climatic growth-limiting factors4. [1] Whittaker RH (1975) Communities and Ecosystems, Macmillan, 385p.[2] Ricklefs RE (2008) The Economy of Nature, W. H. Freeman, 620p.[3] Field CB, Randerson JT, Malmström CM (1995) Global net primary production: Combining ecology and remote sensing. Remote Sensing of Environment, 51, 74-88.[4] Schenkel D, Garonna I, De Jong R, Schaepman ME (this conference) Linking Land Surface Phenology and Growth Limiting Factor Shifts over the Past 30 Years.[5] University of Zurich Research Priority Program on Global Change and Biodiversity, http://www.gcb.uzh.ch

Employment perspectives of patients with ankylosing spondylitis.

PubMed

Chorus, A M J; Boonen, A; Miedema, H S; van der Linden, Sj

2002-08-01

To assess the labour market position of patients with ankylosing spondylitis (AS) in relation to disease duration and to identify potential factors in relation to withdrawal from the labour force. A cross sectional mail survey was conducted among 658 patients with AS. Participation in the labour force was defined as having a paid job. The independent effect of duration of disease was examined by an indirect method of standardisation. A broad variety of risk factors were examined separately and in a combined analysis, including sociodemographic factors, disease related variables, coping styles, and work related factors. Attributable and preventable fractions were calculated from the combined analyses to assess the relative importance of the contributing factors. Probability of participation in the labour force was similarly reduced in patients with AS with different durations of disease. Pacing to cope with limitations was the most relevant factor in increasing the risk of withdrawal from the labour force, accounting for 73% of withdrawals. Coping with limitations by often seeking creative solutions, high disease activity, increased age, and insufficient support from colleagues or management were also positively associated with withdrawal from the labour force. Technical or ergonomic adjustments of the workplace, working in large companies, and coping with dependency style through frequent acceptance were negatively associated. Of these factors, technical or ergonomic adjustment was the most relevant in terms of reducing the risk. Sociodemographic factors, disease related factors, coping styles, and work related factors contribute simultaneously to withdrawal from the labour force.

A systematic review of grandparents’ influence on grandchildren’s cancer risk factors

PubMed Central

2017-01-01

Many lifestyle patterns are established when children are young. Research has focused on the potential role of parents as a risk factor for non communicable disease in children, but there is limited investigation of the role of other caregivers, such as grandparents. The aim of this review was to identify and synthesise evidence for any influence grandparents’ care practices may have on their grandchildren’s long term cancer risk factors. A systematic review was carried out with searches across four databases (MEDLINE, Embase, Web of Science, PsycINFO) as well as searches of reference lists and citing articles, and Google Scholar. Search terms were based on six areas of risk that family care could potentially influence–weight, diet, physical activity, tobacco, alcohol and sun exposure. All study designs were included, as were studies that provided an indication of the interaction of grandparents with their grandchildren. Studies were excluded if grandparents were primary caregivers and if children had serious health conditions. Study quality was assessed using National Institute for Health and Care Excellence checklists. Grandparent impact was categorised as beneficial, adverse, mixed or as having no impact. Due to study heterogeneity a meta-analysis was not possible. Qualitative studies underwent a thematic synthesis of their results. Results from all included studies indicated that there was a sufficient evidence base for weight, diet, physical activity and tobacco studies to draw conclusions about grandparents’ influence. One study examined alcohol and no studies examined sun exposure. Evidence indicated that, overall, grandparents had an adverse impact on their grandchildren’s cancer risk factors. The theoretical work in the included studies was limited. Theoretically underpinned interventions designed to reduce these risk factors must consider grandparents’ role, as well as parents’, and be evaluated robustly to inform the evidence base further. PMID:29135979

An epidemiological survey on the prevalence of equine peripheral dental caries in the United Kingdom and possible risk factors for its development.

PubMed

Borkent, D; Reardon, R J M; McLachlan, G; Smith, S; Dixon, P M

2017-07-01

Equine peripheral caries (PC) is an increasingly recognised disorder that causes premature wear of teeth and dental fractures and thus has major welfare implications. Little information is available on its prevalence or severity in UK horses and there are no proven associations with any risk factors. To document the prevalence of PC over a wide area of the UK, assess its intraoral distribution and severity in affected horses and examine for potential risk factors for its development. Cross sectional study. Experienced personnel were recruited for a UK wide dental survey on their patients during dental examinations. Established guidelines were used for grading PC. Frequency of PC occurrence was compared between teeth and dental arcades using McNemar's tests. Potential risk factors for PC were screened using univariable logistic regression prior to building a multivariable model. A total of 706 horses were examined by 25 participants, showing a 51.7% prevalence of PC (365/706). Some regional differences in prevalence were found. The PC primarily affected the cheek teeth with the 12 caudal being significantly more commonly affected than the 12 rostral cheek teeth. Most of the hypothesised risk factors including age, breed, sex, time at pasture and feeding of silage (haylage) were unproven. A limited association with moderate levels of concentrate feeding was observed. The presence of concurrent dental abnormalities were significantly associated with the likelihood of having PC. Not all regions in UK were included and there may be inconsistencies between examiners. Peripheral caries is common in British horses, primarily affecting the caudal cheek teeth. There was limited evidence of an association between feeding and PC. The association between PC and concurrent dental disorders indicates that these should be addressed in affected horses. © 2016 EVJ Ltd.

Hydrologic controls on nitrogen cycling processes and functional gene abundance in sediments of a groundwater flow-through lake

USGS Publications Warehouse

Stoliker, Deborah L.; Repert, Deborah A.; Smith, Richard L.; Song, Bongkeun; LeBlanc, Denis R.; McCobb, Timothy D.; Conaway, Christopher; Hyun, Sung Pil; Koh, Dong-Chan; Moon, Hee Sun; Kent, Douglas B.

2016-01-01

The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod, MA. These factors included water chemistry, seepage rates and direction of groundwater flow, and the abundance and potential rates of activity of N-cycling microbial communities. Genes coding for denitrification, anaerobic ammonium oxidation (anammox), and nitrification were identified at all sites regardless of flow direction or groundwater dissolved oxygen concentrations. Flow direction was, however, a controlling factor in the potential for N-attenuation via denitrification in the sediments. Potential rates of denitrification varied from 6 to 4500 pmol N/g/h from the inflow to the outflow side of the lake, owing to fundamental differences in the supply of labile organic matter. The results of laboratory incubations suggested that when anoxia and limiting labile organic matter prevailed, the potential existed for concomitant anammox and denitrification. Where oxic lake water was downwelling, potential rates of nitrification at shallow depths were substantial (1640 pmol N/g/h). Rates of anammox, denitrification, and nitrification may be linked to rates of organic N-mineralization, serving to increase N-mobility and transport downgradient.

Immunoproteomic identification of immunogenic proteins in Cronobacter sakazakii strain BAA-894.

PubMed

Wang, Jian; Du, Xin-Jun; Lu, Xiao-Nan; Wang, Shuo

2013-03-01

Cronobacter spp. are emerging opportunistic pathogens. Cronobacter sakazakii is considered as the predominant species in all infections. So far, our understanding of the species' immunogens and potential virulence factors of Cronobacter spp. remains limited. In this study, an immunoproteomic approach was used to investigate soluble and insoluble proteins from the genome-sequenced strain C. sakazakii ATCC BAA-894. Proteins were separated using two-dimensional electrophoresis, detected by Western blotting with polyclonal antibodies of C. sakazakii BAA-894, and identified using tandem mass spectrometry (MALDI-MS and MALDI-MS/MS, MS/MSMS). A total of 11 immunoreactive proteins were initially identified in C. sakazakii BAA-894, including two outer membrane proteins, four periplasmic proteins, and five cytoplasmic proteins. In silico functional analysis of the 11 identified proteins indicated three proteins that were initially described as immunogens of pathogenic bacteria. For the remaining eight proteins, one protein was categorized as a potential virulence factor involved in protection against reactive oxygen species, and seven proteins were considered to play potential roles in adhesion, invasion, and biofilm formation. To our knowledge, this is the first time that immunogenic proteins of C. sakazakii BAA-894 have been identified as immunogens and potential virulence factors by an immunoproteomics approach. Future studies should investigate the roles of these proteins in bacterial pathogenesis and modulation of host immune responses during infection to identify their potential as molecular therapeutic targets.

Hydrologic Controls on Nitrogen Cycling Processes and Functional Gene Abundance in Sediments of a Groundwater Flow-Through Lake.

PubMed

Stoliker, Deborah L; Repert, Deborah A; Smith, Richard L; Song, Bongkeun; LeBlanc, Denis R; McCobb, Timothy D; Conaway, Christopher H; Hyun, Sung Pil; Koh, Dong-Chan; Moon, Hee Sun; Kent, Douglas B

2016-04-05

The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod, MA. These factors included water chemistry, seepage rates and direction of groundwater flow, and the abundance and potential rates of activity of N-cycling microbial communities. Genes coding for denitrification, anaerobic ammonium oxidation (anammox), and nitrification were identified at all sites regardless of flow direction or groundwater dissolved oxygen concentrations. Flow direction was, however, a controlling factor in the potential for N-attenuation via denitrification in the sediments. Potential rates of denitrification varied from 6 to 4500 pmol N/g/h from the inflow to the outflow side of the lake, owing to fundamental differences in the supply of labile organic matter. The results of laboratory incubations suggested that when anoxia and limiting labile organic matter prevailed, the potential existed for concomitant anammox and denitrification. Where oxic lake water was downwelling, potential rates of nitrification at shallow depths were substantial (1640 pmol N/g/h). Rates of anammox, denitrification, and nitrification may be linked to rates of organic N-mineralization, serving to increase N-mobility and transport downgradient.

Connecting RNA Processing to Abiotic Environmental Response in Arabidopsis: the role of a polyadenylation factor

NASA Astrophysics Data System (ADS)

Li, Q. Q.; Xu, R.; Hunt, A. G.; Falcone, D. L.

Plants are constantly challenged by numerous environmental stresses both biotic and abiotic It is clear that plants have evolved to counter these stresses using all but limited means We recently discovered the potential role of a messenger RNA processing factor namely the Arabidopsis cleavage and polyadenylation specificity factor 30 kDa subunit AtCPSF30 when a mutant deficient in this factor displayed altered responses to an array of abiotic stresses This AtCPSF30 mutant named oxt6 exhibited an elevated tolerance to oxidative stress Microarray experiments of oxt6 and its complemented lines revealed an altered gene expression profile among which were antioxidative defense genes Interestingly the same gene encoding AtCPSF30 can also be transcribed into a large transcript that codes for a potential splicing factor Both protein products have a domain for RNA binding and a calmodulin binding domain activities of which have been confirmed by biochemical assays Surprisingly binding of AtCPSF30 to calmodulin inhibits the RNA-binding activity of the protein Mutational analysis shows that a small part of the protein is responsible for calmodulin binding and point mutations in this region abolished both RNA binding activity and the inhibition of this activity by calmodulin Analyses of the potential splicing factor are on going and the results will be presented The interesting possibilities for both the interplay between splicing and polyadenylation and the regulation of these processes by stimuli that act through

Air pollution, inflammation and preterm birth: a potential mechanistic link.

PubMed

Vadillo-Ortega, Felipe; Osornio-Vargas, Alvaro; Buxton, Miatta A; Sánchez, Brisa N; Rojas-Bracho, Leonora; Viveros-Alcaráz, Martin; Castillo-Castrejón, Marisol; Beltrán-Montoya, Jorge; Brown, Daniel G; O'Neill, Marie S

2014-02-01

Preterm birth is a public health issue of global significance, which may result in mortality during the perinatal period or may lead to major health and financial consequences due to lifelong impacts. Even though several risk factors for preterm birth have been identified, prevention efforts have failed to halt the increasing rates of preterm birth. Epidemiological studies have identified air pollution as an emerging potential risk factor for preterm birth. However, many studies were limited by study design and inadequate exposure assessment. Due to the ubiquitous nature of ambient air pollution and the potential public health significance of any role in causing preterm birth, a novel focus investigating possible causal mechanisms influenced by air pollution is therefore a global health priority. We hypothesize that air pollution may act together with other biological factors to induce systemic inflammation and influence the duration of pregnancy. Evaluation and testing of this hypothesis is currently being conducted in a prospective cohort study in Mexico City and will provide an understanding of the pathways that mediate the effects of air pollution on preterm birth. The important public health implication is that crucial steps in this mechanistic pathway can potentially be acted on early in pregnancy to reduce the risk of preterm birth. Copyright © 2013 Elsevier Ltd. All rights reserved.

AIR POLLUTION, INFLAMMATION AND PRETERM BIRTH: A POTENTIAL MECHANISTIC LINK

PubMed Central

Vadillo-Ortega, Felipe; Osornio-Vargas, Alvaro; Buxton, Miatta A.; Sánchez, Brisa N.; Rojas-Bracho, Leonora; Viveros-Alcaráz, Martin; Castillo-Castrejón, Marisol; Beltrán-Montoya, Jorge; Brown, Daniel G.; O´Neill, Marie S.

2014-01-01

Preterm birth is a public health issue of global significance, which may result in mortality during the perinatal period or may lead to major health and financial consequences due to lifelong impacts. Even though several risk factors for preterm birth have been identified, prevention efforts have failed to halt the increasing rates of preterm birth. Epidemiological studies have identified air pollution as an emerging potential risk factor for preterm birth. However, many studies were limited by study design and inadequate exposure assessment. Due to the ubiquitous nature of ambient air pollution and the potential public health significance of any role in causing preterm birth, a novel focus investigating possible causal mechanisms influenced by air pollution is therefore a global health priority. We hypothesize that air pollution may act together with other biological factors to induce systemic inflammation and influence the duration of pregnancy. Evaluation and testing of this hypothesis is currently being conducted in a prospective cohort study in Mexico City and will provide an understanding of the pathways that mediate the effects of air pollution on preterm birth. The important public health implication is that crucial steps in this mechanistic pathway can potentially be acted on early in pregnancy to reduce the risk of preterm birth. PMID:24382337

Potential Roles of Dental Pulp Stem Cells in Neural Regeneration and Repair

PubMed Central

Luo, Lihua; Wang, Xiaoyan; Key, Brian; Lee, Bae Hoon

2018-01-01

This review summarizes current advances in dental pulp stem cells (DPSCs) and their potential applications in the nervous diseases. Injured adult mammalian nervous system has a limited regenerative capacity due to an insufficient pool of precursor cells in both central and peripheral nervous systems. Nerve growth is also constrained by inhibitory factors (associated with central myelin) and barrier tissues (glial scarring). Stem cells, possessing the capacity of self-renewal and multicellular differentiation, promise new therapeutic strategies for overcoming these impediments to neural regeneration. Dental pulp stem cells (DPSCs) derive from a cranial neural crest lineage, retain a remarkable potential for neuronal differentiation, and additionally express multiple factors that are suitable for neuronal and axonal regeneration. DPSCs can also express immunomodulatory factors that stimulate formation of blood vessels and enhance regeneration and repair of injured nerve. These unique properties together with their ready accessibility make DPSCs an attractive cell source for tissue engineering in injured and diseased nervous systems. In this review, we interrogate the neuronal differentiation potential as well as the neuroprotective, neurotrophic, angiogenic, and immunomodulatory properties of DPSCs and its application in the injured nervous system. Taken together, DPSCs are an ideal stem cell resource for therapeutic approaches to neural repair and regeneration in nerve diseases. PMID:29853908

A risk modelling approach for setting microbiological limits using enterococci as indicator for growth potential of Salmonella in pork.

PubMed

Bollerslev, Anne Mette; Nauta, Maarten; Hansen, Tina Beck; Aabo, Søren

2017-01-02

Microbiological limits are widely used in food processing as an aid to reduce the exposure to hazardous microorganisms for the consumers. However, in pork, the prevalence and concentrations of Salmonella are generally low and microbiological limits are not considered an efficient tool to support hygiene interventions. The objective of the present study was to develop an approach which could make it possible to define potential risk-based microbiological limits for an indicator, enterococci, in order to evaluate the risk from potential growth of Salmonella. A positive correlation between the concentration of enterococci and the prevalence and concentration of Salmonella was shown for 6640 pork samples taken at Danish cutting plants and retail butchers. The samples were collected in five different studies in 2001, 2002, 2010, 2011 and 2013. The observations that both Salmonella and enterococci are carried in the intestinal tract, contaminate pork by the same mechanisms and share similar growth characteristics (lag phase and maximum specific growth rate) at temperatures around 5-10°C, suggest a potential of enterococci to be used as an indicator of potential growth of Salmonella in pork. Elevated temperatures during processing will lead to growth of both enterococci and, if present, also Salmonella. By combining the correlation between enterococci and Salmonella with risk modelling, it is possible to predict the risk of salmonellosis based on the level of enterococci. The risk model used for this purpose includes the dose-response relationship for Salmonella and a reduction factor to account for preparation of the fresh pork. By use of the risk model, it was estimated that the majority of salmonellosis cases, caused by the consumption of pork in Denmark, is caused by the small fraction of pork products that has enterococci concentrations above 5logCFU/g. This illustrates that our approach can be used to evaluate the potential effect of different microbiological limits and therefore, the perspective of this novel approach is that it can be used for definition of a risk-based microbiological limit for enterococci. The limit for enterococci can then be used for development of a process hygiene criterion in cutting plants and retail butcher shops, with the purpose of reducing the risk of Salmonella for the consumer. Copyright © 2016 Elsevier B.V. All rights reserved.

Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality.

PubMed

Filipiak, Michał; Kuszewska, Karolina; Asselman, Michel; Denisow, Bożena; Stawiarz, Ernest; Woyciechowski, Michał; Weiner, January

2017-01-01

The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees' need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using "dirty water". Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees.

Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality

PubMed Central

Kuszewska, Karolina; Asselman, Michel; Denisow, Bożena; Stawiarz, Ernest; Woyciechowski, Michał; Weiner, January

2017-01-01

The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees’ need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using “dirty water”. Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees. PMID:28829793

A uniform bacterial growth potential assay for different water types.

PubMed

Farhat, Nadia; Hammes, Frederik; Prest, Emmanuelle; Vrouwenvelder, Johannes

2018-06-06

The bacterial growth potential is important to understand and manage bacterial regrowth-related water quality concerns. Bacterial growth potential depends on growth promoting/limiting compounds, therefore, nutrient availability is the key factor governing bacterial growth potential. Selecting proper tools for bacterial growth measurement is essential for routine implementation of the growth potential measurement. This study proposes a growth potential assay that is universal and can be used for different water types and soil extract without restrictions of pure culture or cultivability of the bacterial strain. The proposed assay measures the sample bacterial growth potential by using the indigenous community as inocula. Flow cytometry (FCM) and adenosine tri-phosphate (ATP) were used to evaluate the growth potential of six different microbial communities indigenous to the sample being analyzed, with increasing carbon concentrations. Bottled mineral water, non-chlorinated tap water, seawater, river water, wastewater effluent and a soil organic carbon extract were analyzed. Results showed that indigenous bacterial communities followed normal batch growth kinetics when grown on naturally present organic carbon. Indigenous bacterial growth could detect spiked organic carbon concentrations as low as 10 μg/L. The indigenous community in all samples responded proportionally to the increase in acetate-carbon and proportional growth could be measured with both FCM and ATP. Bacterial growth was proportional to the carbon concentration but not the same proportion factor for the different water samples tested. The effect of inoculating the same water with different indigenous microbial communities on the growth potential was also examined. The FCM results showed that the highest increase in total bacterial cell concentration was obtained with bacteria indigenous to the water sample. The growth potential assay using indigenous bacterial community revealed consistent results of bacterial growth in all the different samples tested and therefore providing a fast, more stable, and accurate approach for monitoring the biological stability of waters compared to the previously developed assays. The growth potential assay can be used to aid in detecting growth limitations by compounds other than organic carbon. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combined early and adult life risk factor associations for mid-life obesity in a prospective birth cohort: assessing potential public health impact.

PubMed

Pinto Pereira, Snehal M; van Veldhoven, Karin; Li, Leah; Power, Chris

2016-04-12

The combined effect of life-course influences on obesity development and thus their potential public health impact is unclear. We evaluated combined associations and predicted probabilities for early and adult life risk factors with central and general obesity in mid-adulthood. 1958 British birth cohort. 4629 males and 4670 females with data on waist circumference. 45 year obesity measured via waist circumference, waist-hip ratio (WHR) and BMI. At 45 years, approximately a third of the population were centrally obese and a quarter were generally obese. Three factors (parental overweight, maternal smoking during pregnancy and adult inactivity) were consistently associated with central and general obesity. Predicted probabilities for waist obesity increased from those with none to all three risk factors (0.15-0.33 in men; 0.19-0.39 in women (ptrend<0.001)), with a similar trend for general obesity. Additional factors (adult smoking, low fibre and heavy alcohol consumption) were associated with WHR obesity, although varying by gender. Prevalence of risk factors was higher in manual than non-manual groups: for example, in men 38% versus 25%, respectively, had ≥2 risk factors for waist and general obesity. Early-life and adult factors that are amenable to change are highly prevalent and accumulate in association with central and general obesity in mid-adulthood. The increase in probabilities for mid-adult obesity associated with cumulative levels of risk factors suggests the potential for public health impact. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Sudden asphyxial death complicating infectious mononucleosis.

PubMed

Boglioli, L R; Taff, M L

1998-06-01

Infectious mononucleosis (IM) is a disease traditionally defined by a triad of clinical, laboratory, and serologic factors. It is typically a benign, self-limited disease of children and young adults. Upper airway obstruction is a rare but potentially fatal complication of IM resulting from massive tonsillar enlargement, pharyngeal edema, or both. We report a case of sudden death due to airway obstruction in IM.

Information Seeking and Intentions to Have Genetic Testing for Hereditary Cancers in Rural and Appalachian Kentuckians

ERIC Educational Resources Information Center

Kelly, Kimberly M.; Andrews, James E; Case, Donald O.; Allard, Suzanne L.; Johnson, J. David

2007-01-01

Context: Research is limited regarding the potential of genetic testing for cancer risk in rural Appalachia. Purpose: This study examined perceptions of genetic testing in a population sample of Kentuckians, with a focus on Appalachian and rural differences. The goals were to examine cultural and psychosocial factors that may predict intentions to…

Use of wood energy for lumber drying and community heating in southeast Alaska

Treesearch

David L. Nicholls; John I. Zerbe; Richard D. Bergman; Peter M. Crimp

2004-01-01

The inadequate transportation infrastructure and undeveloped markets for sawmill residues in southeast Alaska are among the factors that limit the use of this forest resource. This study considers the potential use of sawmill residues to supply two bioenergy systems that would produce thermal energy for (1) community heating and (2) a lumber dry kiln in Hoonah, Alaska...

An ecosystem approach to determining effects of prescribed fire on southwestern borderlands oak savannas: A baseline study

Treesearch

Gerald J. Gottfried; Daniel G. Neary; Peter F. Ffolliott

2007-01-01

Many traditional land management activities and supporting research have concentrated on one or two resources, with limited evaluations of interactions among other potential values. An ecosystem approach to land management requires an evaluation of the blend of physical and biological factors needed to assure productive, healthy ecosystems. Ideally, social and economic...

Barriers and Facilitators to Adoption of a Lay-Delivered Community-Based Strength Training Program for Women in Rural Areas

ERIC Educational Resources Information Center

Washburn, Lisa T.; Cornell, Carol E.; Traywick, LaVona; Felix, Holly C.; Phillips, Martha E.

2017-01-01

Background: Limited access to fitness programs for rural older adults make lay or volunteer delivery approaches potentially desirable to extend reach. However, factors affecting adoption of such approaches are not well explored. Purpose: This study sought to identify barriers and facilitators affecting adoption of a volunteer lay delivery approach…

Opening Doors to Success in Multilingual Classrooms: Bilingualism, Codeswitching and the Professional Identities of Ethnic Minority Primary Teachers

ERIC Educational Resources Information Center

Conteh, Jean

2007-01-01

In England, government initiatives to recruit more ethnic minority teachers into mainstream schools have met with only limited success. One important reason for this may be that the factors that contribute to their distinctive professional skills and identities, and their potential to help raise the achievements of ethnic minority pupils, are not…

Factors influencing soil aggregation and particulate organic matter responses to bioenergy crops across a topographic gradient

Treesearch

Todd A. Ontl; Cynthia A. Cambardella; Lisa A. Schulte; Randall K. Kolka

2015-01-01

Bioenergy crops have the potential to enhance soil carbon (C) pools from increased aggregation and the physical protection of organic matter; however, our understanding of the variation in these processes over heterogeneous landscapes is limited. In particular, little is known about the relative importance of soil properties and root characteristics for the physical...

Investigating the Roles of Perceived Playfulness, Resistance to Change and Self-Management of Learning in Mobile English Learning Outcome

ERIC Educational Resources Information Center

Huang, Rui-Ting; Jang, Syh-Jong; Machtmes, Krisanna; Deggs, David

2012-01-01

Although there is a growing interest in mobile learning, there are limited studies that focus on student knowledge acquisition. As applications and usages of mobile technology have become more and more accepted, it is important and meaningful that researchers and practitioners of mobile learning understand the potential factors that could…

Healing Africa? Reflections on the peace-building role of a health-based non governmental organization operating in eastern Democratic Republic of Congo.

PubMed

D'Errico, Nicole C; Wake, Christopher M; Wake, Rachel M

2010-01-01

Whilst there are convincing theoretical arguments about the peace-building potential of the health sector, case studies documenting its interventions remain limited. This article contributes to the existing 'Peace through Health' literature by considering the model of HEAL Africa, a health-based non-governmental organization operating in Eastern Congo. Several of HEAL Africa's projects seek to prevent and reduce key risk factors; for conflict, and to contribute to longer term rehabilitation. Many of these interventions are born out of HEAL's emphasis on providing emergency health care--and the neutrality, legitimacy, access and longevity which this generates. However, this focus also tends to act as a limiting factor on the application and resourcing of its conflict prevention and reconstruction efforts. Whilst this case study warns against overstating the potential role of the health sector in promoting peace, HEAL's activities provide evidence of the types of positive contributions that can be made in practice. The role of the health sector, equipped as it is with useful tools for conflict transformation, should therefore be considered more proactively by the peace-building community.

Genotypic distribution of a specialist model microorganism, Methanosaeta, along an estuarine gradient: does metabolic restriction limit niche differentiation potential?

PubMed

Carbonero, Franck; Oakley, Brian B; Hawkins, Robert J; Purdy, Kevin J

2012-05-01

A reductionist ecological approach of using a model genus was adopted in order to understand how microbial community structure is driven by metabolic properties. The distribution along an estuarine gradient of the highly specialised genus Methanosaeta was investigated and compared to the previously determined distribution of the more metabolically flexible Desulfobulbus. Methanosaeta genotypic distribution along the Colne estuary (Essex, UK) was determined by DNA- and RNA-based denaturing gradient gel electrophoresis and 16S rRNA gene sequence analyses. Methanosaeta distribution was monotonic, with a consistently diverse community and no apparent niche partitioning either in DNA or RNA analyses. This distribution pattern contrasts markedly with the previously described niche partitioning and sympatric differentiation of the model generalist, Desulfobulbus. To explain this difference, it is hypothesised that Methanosaeta's strict metabolic needs limit its adaptation potential, thus populations do not partition into spatially distinct groups and so do not appear to be constrained by gross environmental factors such as salinity. Thus, at least for these two model genera, it appears that metabolic flexibility may be an important factor in spatial distribution and this may be applicable to other microbes.

Wideband optical sensing using pulse interferometry.

PubMed

Rosenthal, Amir; Razansky, Daniel; Ntziachristos, Vasilis

2012-08-13

Advances in fabrication of high-finesse optical resonators hold promise for the development of miniaturized, ultra-sensitive, wide-band optical sensors, based on resonance-shift detection. Many potential applications are foreseen for such sensors, among them highly sensitive detection in ultrasound and optoacoustic imaging. Traditionally, sensor interrogation is performed by tuning a narrow linewidth laser to the resonance wavelength. Despite the ubiquity of this method, its use has been mostly limited to lab conditions due to its vulnerability to environmental factors and the difficulty of multiplexing - a key factor in imaging applications. In this paper, we develop a new optical-resonator interrogation scheme based on wideband pulse interferometry, potentially capable of achieving high stability against environmental conditions without compromising sensitivity. Additionally, the method can enable multiplexing several sensors. The unique properties of the pulse-interferometry interrogation approach are studied theoretically and experimentally. Methods for noise reduction in the proposed scheme are presented and experimentally demonstrated, while the overall performance is validated for broadband optical detection of ultrasonic fields. The achieved sensitivity is equivalent to the theoretical limit of a 6 MHz narrow-line width laser, which is 40 times higher than what can be usually achieved by incoherent interferometry for the same optical resonator.

14 CFR 27.337 - Limit maneuvering load factor.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 27.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5 for...

14 CFR 29.337 - Limit maneuvering load factor.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 29.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5 for...

Marital Status as a Moderating Factor in the Process of Disablement.

PubMed

Kail, Ben Lennox

2016-02-01

To test current marital status as a moderator on the influence of depressive symptoms and chronic conditions on subsequent functional limitations. Data come from the Health and Retirement Study (HRS; 1998-2010). Hierarchal linear modeling models tested differences in functional limitations among a sample of 20,215 people. At baseline, married people suffered from fewer subsequent functional limitations than the unmarried. Moreover, limited evidence suggests the influence of depressive symptoms was greater for the married than the unmarried; however, the influence of chronic conditions was consistently attenuated for married people. Accounting for differences in prior health, work, socioeconomic status, and health behaviors did not explain the moderating influence of marital status on the associations between symptoms of depression and chronic conditions with functional limitations. This research highlights the need to identify potential modifiers that may help disrupt the process of disablement among both the married and the unmarried alike. © The Author(s) 2015.

A cross-national exploration of societal-level factors associated with child physical abuse and neglect.

PubMed

Klevens, Joanne; Ports, Katie A; Austin, Chelsea; Ludlow, Ivan J; Hurd, Jacqueline

2017-11-28

Children around the world experience violence at the hands of their caregivers at alarming rates. A recent review estimates that a minimum of 50% of children in Asia, Africa, and North America experienced severe physical violence by caregivers in the past year, with large variations between countries. Identifying modifiable country-level factors driving these geographic variations has great potential for achieving population-level reductions in rates of child maltreatment. This study builds on previous research by focusing on caregiver-reported physical abuse and neglect victimisation, examining 22 societal factors representing 11 different constructs among 42 countries from 5 continents at different stages of development. Our findings suggest that gender inequity may be important for both child physical abuse and neglect. Indicators of literacy and development may also be important for child neglect. Given the limitations of the correlational findings and measurement issues, it is critical to continue to investigate societal-level factors of child maltreatment so that interventions and prevention efforts can incorporate strategies that have the greatest potential for population-level impact.

Guidelines of the National Comprehensive Cancer Network on the use of myeloid growth factors with cancer chemotherapy: a review of the evidence.

PubMed

Lyman, Gary H

2005-07-01

The prophylactic use of myeloid growth factors reduces the risk of chemotherapy-induced neutropenia and its complications, including febrile neutropenia and infection-related mortality. Perhaps most importantly, the prophylactic use of colony-stimulating factors (CSFs) has been shown to reduce the need for chemotherapy dose reductions and delays that may limit chemotherapy dose intensity, thereby increasing the potential for prolonged disease-free and overall survival in the curative setting. National surveys have shown that the majority of patients with potentially curable breast cancer or non-Hodgkin's lymphoma (NHL) do not receive prophylactic CSF support. In this issue, the National Comprehensive Cancer Network presents guidelines for the use of myeloid growth factors in patients with cancer. These guidelines recommend a balanced clinical evaluation of the potential benefits and harms associated with chemotherapy to define the treatment intention, followed by a careful assessment of the individual patient's risk for febrile neutropenia and its complications. The decision to use prophylactic CSFs is then based on the patient's risk and potential benefit from such treatment. The routine prophylactic use of CSFs in patients receiving systemic chemotherapy is recommended in patients at high risk (>20%) of developing febrile neutropenia or related complications that may compromise treatment. Where compelling clinical indications are absent, the potential for CSF prophylaxis to reduce or offset costs by preventing hospitalization for FN should be considered. The clinical, economic, and quality of life data in support of these recommendations are reviewed, and important areas of ongoing research are highlighted.

Pseudo hard-sphere potential for use in continuous molecular-dynamics simulation of spherical and chain molecules

NASA Astrophysics Data System (ADS)

Jover, J.; Haslam, A. J.; Galindo, A.; Jackson, G.; Müller, E. A.

2012-10-01

We present a continuous pseudo-hard-sphere potential based on a cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). Using this potential one can mimic the volumetric, structural, and dynamic properties of the discontinuous hard-sphere potential over the whole fluid range. The continuous pseudo potential has the advantage that it may be incorporated directly into off-the-shelf molecular-dynamics code, allowing the user to capitalise on existing hardware and software advances. Simulation results for the compressibility factor of the fluid and solid phases of our pseudo hard spheres are presented and compared both to the Carnahan-Starling equation of state of the fluid and published data, the differences being indistinguishable within simulation uncertainty. The specific form of the potential is employed to simulate flexible chains formed from these pseudo hard spheres at contact (pearl-necklace model) for mc = 4, 5, 7, 8, 16, 20, 100, 201, and 500 monomer segments. The compressibility factor of the chains per unit of monomer, mc, approaches a limiting value at reasonably small values, mc < 50, as predicted by Wertheim's first order thermodynamic perturbation theory. Simulation results are also presented for highly asymmetric mixtures of pseudo hard spheres, with diameter ratios of 3:1, 5:1, 20:1 over the whole composition range.

The Relationship between Elemental Carbon and Diesel Particulate Matter in Underground Metal/Nonmetal Mines in the United States and Coal Mines in Australia

PubMed Central

Noll, James; Gilles, Stewart; Wu, Hsin Wei; Rubinstein, Elaine

2015-01-01

In the United States, total carbon (TC) is used as a surrogate for determining diesel particulate matter (DPM) compliance exposures in underground metal/nonmetal mines. Since TC can be affected by interferences and elemental carbon (EC) is not, one method used to estimate the TC concentration is to multiply the EC concentration from the personal sample by a conversion factor to avoid the influence of potential interferences. Since there is no accepted single conversion factor for all metal/nonmetal mines, one is determined every time an exposure sample is taken by collecting an area sample that represents the TC/EC ratio in the miner's breathing zone and is away from potential interferences. As an alternative to this procedure, this article investigates the relationship between TC and EC from DPM samples to determine if a single conversion factor can be used for all metal/nonmetal mines. In addition, this article also investigates how well EC represents DPM concentrations in Australian coal mines since the recommended exposure limit for DPM in Australia is an EC value. When TC was predicted from EC values using a single conversion factor of 1.27 in 14 US metal/nonmetal mines, 95% of the predicted values were within 18% of the measured value, even at the permissible exposure limit (PEL) concentration of 160 μg/m3 TC. A strong correlation between TC and EC was also found in nine underground coal mines in Australia. PMID:25380085

A Methodology for Calculating EGS Electricity Generation Potential Based on the Gringarten Model for Heat Extraction From Fractured Rock

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

Augustine, Chad

Existing methodologies for estimating the electricity generation potential of Enhanced Geothermal Systems (EGS) assume thermal recovery factors of 5% or less, resulting in relatively low volumetric electricity generation potentials for EGS reservoirs. This study proposes and develops a methodology for calculating EGS electricity generation potential based on the Gringarten conceptual model and analytical solution for heat extraction from fractured rock. The electricity generation potential of a cubic kilometer of rock as a function of temperature is calculated assuming limits on the allowed produced water temperature decline and reservoir lifetime based on surface power plant constraints. The resulting estimates of EGSmore » electricity generation potential can be one to nearly two-orders of magnitude larger than those from existing methodologies. The flow per unit fracture surface area from the Gringarten solution is found to be a key term in describing the conceptual reservoir behavior. The methodology can be applied to aid in the design of EGS reservoirs by giving minimum reservoir volume, fracture spacing, number of fractures, and flow requirements for a target reservoir power output. Limitations of the idealized model compared to actual reservoir performance and the implications on reservoir design are discussed.« less

A new instrument for measuring anticoagulation-related quality of life: development and preliminary validation

PubMed Central

Samsa, Greg; Matchar, David B; Dolor, Rowena J; Wiklund, Ingela; Hedner, Ewa; Wygant, Gail; Hauch, Ole; Marple, Cheryl Beadle; Edwards, Roger

2004-01-01

Background Anticoagulation can reduce quality of life, and different models of anticoagulation management might have different impacts on satisfaction with this component of medical care. Yet, to our knowledge, there are no scales measuring quality of life and satisfaction with anticoagulation that can be generalized across different models of anticoagulation management. We describe the development and preliminary validation of such an instrument – the Duke Anticoagulation Satisfaction Scale (DASS). Methods The DASS is a 25-item scale addressing the (a) negative impacts of anticoagulation (limitations, hassles and burdens); and (b) positive impacts of anticoagulation (confidence, reassurance, satisfaction). Each item has 7 possible responses. The DASS was administered to 262 patients currently receiving oral anticoagulation. Scales measuring generic quality of life, satisfaction with medical care, and tendency to provide socially desirable responses were also administered. Statistical analysis included assessment of item variability, internal consistency (Cronbach's alpha), scale structure (factor analysis), and correlations between the DASS and demographic variables, clinical characteristics, and scores on the above scales. A follow-up study of 105 additional patients assessed test-retest reliability. Results 220 subjects answered all items. Ceiling and floor effects were modest, and 25 of the 27 proposed items grouped into 2 factors (positive impacts, negative impacts, this latter factor being potentially subdivided into limitations versus hassles and burdens). Each factor had a high degree of internal consistency (Cronbach's alpha 0.78–0.91). The limitations and hassles factors consistently correlated with the SF-36 scales measuring generic quality of life, while the positive psychological impact scale correlated with age and time on anticoagulation. The intra-class correlation coefficient for test-retest reliability was 0.80. Conclusions The DASS has demonstrated reasonable psychometric properties to date. Further validation is ongoing. To the degree that dissatisfaction with anticoagulation leads to decreased adherence, poorer INR control, and poor clinical outcomes, the DASS has the potential to help identify reasons for dissatisfaction (and positive satisfaction), and thus help to develop interventions to break this cycle. As an instrument designed to be applicable across multiple models of anticoagulation management, the DASS could be crucial in the scientific comparison between those models of care. PMID:15132746

Ferroelectricity in Ruddlesden-Popper Chalcogenide Perovskites for Photovoltaic Application: The Role of Tolerance Factor.

PubMed

Zhang, Yajun; Shimada, Takahiro; Kitamura, Takayuki; Wang, Jie

2017-12-07

Chalcogenide perovskites with optimal band gap and desirable light absorption are promising for photovoltaic devices, whereas the absence of ferroelectricity limits their potential in applications. On the basis of first-principles calculations, we reveal the underlying mechanism of the paraelectric nature of Ba 3 Zr 2 S 7 observed in experiments and demonstrate a general rule for the appearance of ferroelectricity in chalcogenide perovskites with Ruddlesden-Popper (RP) A 3 B 2 X 7 structures. Group theoretical analysis shows that the tolerance factor is the primary factor that dominates the ferroelectricity. Both Ba 3 Zr 2 S 7 and Ba 3 Hf 2 S 7 with large tolerance factor are paraelectric because of the suppression of in-phase rotation that is indispensable to hybrid improper ferroelectricity. In contrast, Ca 3 Zr 2 S 7 , Ca 3 Hf 2 S 7 , Ca 3 Zr 2 Se 7 , and Ca 3 Hf 2 S 7 with small tolerance factor exhibit in-phase rotation and can be stable in the ferroelectric Cmc2 1 ground state with nontrivial polarization. These findings not only provide useful guidance to engineering ferroelectricity in RP chalcogenide perovskites but also suggest potential ferroelectric semiconductors for photovoltaic applications.

Substance use and misuse among professional ballet dancers.

PubMed

Sekulic, Damir; Peric, Mia; Rodek, Jelena

2010-07-01

This study investigated substance use and misuse among 16 female and 9 male Croatian ballet professionals in 2008 using an original questionnaire. We analyzed social, personal, activity- and training-related, and educational factors, and criteria such as: binge alcohol drinking, cigarette smoking, appetite suppressant consumption, analgesic use, and actual and potential "doping" habits. Frequency tables and rank-order correlation were calculated. More than one third of the male dancers reported binge drinking, while 20% of the females smoked more than a box of cigarettes per day. Almost 25% of these dancers will use "doping" if it will ensure successful ballet performance, regardless of negative health consequences. In males, the risk of potential "doping" behavior increased with age. In females, education level was negatively related to cigarette smoking, but positively correlated to potential "doping" habits and behavior. In both genders, religiousness was the factor negatively related to the following: (1) potential "doping" behavior and (2) belief that "doping" exists in professional ballet. Results suggest that there is evident need for more specific medical and/or psychological services in professional ballet. The study's limitations are noted.

Emotional rigidity negatively impacts remission from anxiety and recovery of well-being.

PubMed

Wiltgen, Anika; Shepard, Christopher; Smith, Ryan; Fowler, J Christopher

2018-08-15

Emotional rigidity is described in clinical literature as a significant barrier to recovery; however, few there are few empirical measures of the construct. The current study had two aims: Study 1 aimed to identify latent factors that may bear on the construct of emotional rigidity while Study 2 assessed the potential impact of the latent factor(s) on anxiety remission rates and well-being. This study utilized data from 2472 adult inpatients (1176 females and 1296 males) with severe psychopathology. Study 1 utilized exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to identify latent factors of emotional rigidity. Study 2 utilized hierarchical logistic regression analyses to assess the relationships among emotional rigidity factors and anxiety remission and well-being recovery at discharge. Study 1 yielded a two-factor solution identified in EFA was confirmed with CFA. Factor 1 consisted of neuroticism, experiential avoidance, non-acceptance of emotions, impaired goal-directed behavior, impulse control difficulties and limited access to emotion regulation strategies when experiencing negative emotions. Factor 2 consisted of lack of emotional awareness and lack of emotional clarity when experiencing negative emotions. Results of Study 2 indicated higher scores on Factor 1 was associated with lower remission rates from anxiety and poorer well-being upon discharge. Factor 2 was not predictive of outcome. Emotional rigidity appears to be a latent construct that negatively impacts remission rates from anxiety. Limitations of the present study include its retrospective design, and inefficient methods of assessing emotional rigidity. Copyright © 2018. Published by Elsevier B.V.

Theoretical potential for low energy consumption phase change memory utilizing electrostatically-induced structural phase transitions in 2D materials

NASA Astrophysics Data System (ADS)

Rehn, Daniel A.; Li, Yao; Pop, Eric; Reed, Evan J.

2018-01-01

Structural phase-change materials are of great importance for applications in information storage devices. Thermally driven structural phase transitions are employed in phase-change memory to achieve lower programming voltages and potentially lower energy consumption than mainstream nonvolatile memory technologies. However, the waste heat generated by such thermal mechanisms is often not optimized, and could present a limiting factor to widespread use. The potential for electrostatically driven structural phase transitions has recently been predicted and subsequently reported in some two-dimensional materials, providing an athermal mechanism to dynamically control properties of these materials in a nonvolatile fashion while achieving potentially lower energy consumption. In this work, we employ DFT-based calculations to make theoretical comparisons of the energy required to drive electrostatically-induced and thermally-induced phase transitions. Determining theoretical limits in monolayer MoTe2 and thin films of Ge2Sb2Te5, we find that the energy consumption per unit volume of the electrostatically driven phase transition in monolayer MoTe2 at room temperature is 9% of the adiabatic lower limit of the thermally driven phase transition in Ge2Sb2Te5. Furthermore, experimentally reported phase change energy consumption of Ge2Sb2Te5 is 100-10,000 times larger than the adiabatic lower limit due to waste heat flow out of the material, leaving the possibility for energy consumption in monolayer MoTe2-based devices to be orders of magnitude smaller than Ge2Sb2Te5-based devices.

Obstructive urination problems after high-dose-rate brachytherapy boost treatment for prostate cancer are avoidable.

PubMed

Kragelj, Borut

2016-03-01

Aiming at improving treatment individualization in patients with prostate cancer treated with combination of external beam radiotherapy and high-dose-rate brachytherapy to boost the dose to prostate (HDRB-B), the objective was to evaluate factors that have potential impact on obstructive urination problems (OUP) after HDRB-B. In the follow-up study 88 patients consecutively treated with HDRB-B at the Institute of Oncology Ljubljana in the period 2006-2011 were included. The observed outcome was deterioration of OUP (DOUP) during the follow-up period longer than 1 year. Univariate and multivariate relationship analysis between DOUP and potential risk factors (treatment factors, patients' characteristics) was carried out by using binary logistic regression. ROC curve was constructed on predicted values and the area under the curve (AUC) calculated to assess the performance of the multivariate model. Analysis was carried out on 71 patients who completed 3 years of follow-up. DOUP was noted in 13/71 (18.3%) of them. The results of multivariate analysis showed statistically significant relationship between DOUP and anti-coagulation treatment (OR 4.86, 95% C.I. limits: 1.21-19.61, p = 0.026). Also minimal dose received by 90% of the urethra volume was close to statistical significance (OR = 1.23; 95% C.I. limits: 0.98-1.07, p = 0.099). The value of AUC was 0.755. The study emphasized the relationship between DOUP and anticoagulation treatment, and suggested the multivariate model with fair predictive performance. This model potentially enables a reduction of DOUP after HDRB-B. It supports the belief that further research should be focused on urethral sphincter as a critical structure for OUP.

Spatial Variability of Cyanobacteria and Heterotrophic Bacteria in Lake Taihu (China).

PubMed

Qian, Haifeng; Lu, Tao; Song, Hao; Lavoie, Michel; Xu, Jiahui; Fan, Xiaoji; Pan, Xiangliang

2017-09-01

Cyanobacterial blooms frequently occur in Lake Taihu (China), but the intertwined relationships between biotic and abiotic factors modulating the frequency and duration of the blooms remain enigmatic. To better understand the relationships between the key abiotic and biotic factors and cyanobacterial blooms, we measured the abundance and diversity of prokaryotic organisms by high-throughput sequencing, the abundance of key genes involved in microcystin production and nitrogen fixation or loss as well as several physicochemical parameters at several stations in Lake Taihu during a cyanobacterial bloom of Microcystis sp.. Measurements of the copy number of denitrification-related genes and 16S rRNA analyses show that denitrification potential and denitrifying bacteria abundance increased in concert with non-diazotrophic cyanobacteria (Microcystis sp.), suggesting limited competition between cyanobacteria and heterotrophic denitrifiers for nutrients, although potential bacteria-mediated N loss may hamper Microcystis growth. The present study provides insight into the importance of different abiotic and biotic factors in controlling cyanobacteria and heterotrophic bacteria spatial variability in Lake Taihu.

Risk factors for acute toxoplasmosis in England and Wales.

PubMed

Said, B; Halsby, K D; O'Connor, C M; Francis, J; Hewitt, K; Verlander, N Q; Guy, E; Morgan, D

2017-01-01

Over 300 cases of acute toxoplasmosis are confirmed by reference testing in England and Wales annually. We conducted a case-control study to identify risk factors for Toxoplasma gondii infection to inform prevention strategies. Twenty-eight cases and 27 seronegative controls participated. We compared their food history and environmental exposures using logistic regression to calculate odds ratios (OR) and 95% confidence intervals in a model controlling for age and sex. Univariable analysis showed that the odds of eating beef (OR 10·7, P < 0·001), poultry (OR 6·4, P = 0·01) or lamb/mutton (OR 4·9, P = 0·01) was higher for cases than controls. After adjustment for potential confounders a strong association between beef and infection remained (OR 5·6, P = 0·01). The small sample size was a significant limitation and larger studies are needed to fully investigate potential risk factors. The study findings emphasize the need to ensure food is thoroughly cooked and handled hygienically, especially for those in vulnerable groups.

Learning prosthetic vision: a virtual-reality study.

PubMed

Chen, Spencer C; Hallum, Luke E; Lovell, Nigel H; Suaning, Gregg J

2005-09-01

Acceptance of prosthetic vision will be heavily dependent on the ability of recipients to form useful information from such vision. Training strategies to accelerate learning and maximize visual comprehension would need to be designed in the light of the factors affecting human learning under prosthetic vision. Some of these potential factors were examined in a visual acuity study using the Landolt C optotype under virtual-reality simulation of prosthetic vision. Fifteen normally sighted subjects were tested for 10-20 sessions. Potential learning factors were tested at p < 0.05 with regression models. Learning was most evident across-sessions, though 17% of sessions did express significant within-session trends. Learning was highly concentrated toward a critical range of optotype sizes, and subjects were less capable in identifying the closed optotype (a Landolt C with no gap, forming a closed annulus). Training for implant recipients should target these critical sizes and the closed optotype to extend the limit of visual comprehension. Although there was no evidence that image processing affected overall learning, subjects showed varying personal preferences.

Physiology limits commercially viable photoautotrophic production of microalgal biofuels.

PubMed

Kenny, Philip; Flynn, Kevin J

2017-01-01

Algal biofuels have been offered as an alternative to fossil fuels, based on claims that microalgae can provide a highly productive source of compounds as feedstocks for sustainable transport fuels. Life cycle analyses identify algal productivity as a critical factor affecting commercial and environmental viability. Here, we use mechanistic modelling of the biological processes driving microalgal growth to explore optimal production scenarios in an industrial setting, enabling us to quantify limits to algal biofuels potential. We demonstrate how physiological and operational trade-offs combine to restrict the potential for solar-powered algal-biodiesel production in open ponds to a ceiling of ca. 8000 L ha -1 year -1 . For industrial-scale operations, practical considerations limit production to ca. 6000 L ha -1 year -1 . According to published economic models and life cycle analyses, such production rates cannot support long-term viable commercialisation of solar-powered cultivation of natural microalgae strains exclusively as feedstock for biofuels. The commercial viability of microalgal biofuels depends critically upon limitations in microalgal physiology (primarily in rates of C-fixation); we discuss the scope for addressing this bottleneck concluding that even deployment of genetically modified microalgae with radically enhanced characteristics would leave a very significant logistical if not financial burden.

Candidates for a possible third-generation gravitational wave detector: comparison of ring-Sagnac and sloshing-Sagnac speedmeter interferometers

NASA Astrophysics Data System (ADS)

Huttner, S. H.; Danilishin, S. L.; Barr, B. W.; Bell, A. S.; Gräf, C.; Hennig, J. S.; Hild, S.; Houston, E. A.; Leavey, S. S.; Pascucci, D.; Sorazu, B.; Spencer, A. P.; Steinlechner, S.; Wright, J. L.; Zhang, T.; Strain, K. A.

2017-01-01

Speedmeters are known to be quantum non-demolition devices and, by potentially providing sensitivity beyond the standard quantum limit, become interesting for third generation gravitational wave detectors. Here we introduce a new configuration, the sloshing-Sagnac interferometer, and compare it to the more established ring-Sagnac interferometer. The sloshing-Sagnac interferometer is designed to provide improved quantum noise limited sensitivity and lower coating thermal noise than standard position meter interferometers employed in current gravitational wave detectors. We compare the quantum noise limited sensitivity of the ring-Sagnac and the sloshing-Sagnac interferometers, in the frequency range, from 5 Hz to 100 Hz, where they provide the greatest potential benefit. We evaluate the improvement in terms of the unweighted noise reduction below the standard quantum limit, and by finding the range up to which binary black hole inspirals may be observed. The sloshing-Sagnac was found to give approximately similar or better sensitivity than the ring-Sagnac in all cases. We also show that by eliminating the requirement for maximally-reflecting cavity end mirrors with correspondingly-thick multi-layer coatings, coating noise can be reduced by a factor of approximately 2.2 compared to conventional interferometers.

Algorithms for the prediction of retinopathy of prematurity based on postnatal weight gain.

PubMed

Binenbaum, Gil

2013-06-01

Current ROP screening guidelines represent a simple risk model with two dichotomized factors, birth weight and gestational age at birth. Pioneering work has shown that tracking postnatal weight gain, a surrogate for low insulin-like growth factor 1, may capture the influence of many other ROP risk factors and improve risk prediction. Models including weight gain, such as WINROP, ROPScore, and CHOP ROP, have demonstrated accurate ROP risk assessment and a potentially large reduction in ROP examinations, compared to current guidelines. However, there is a need for larger studies, and generalizability is limited in countries with developing neonatal care systems. Copyright © 2013 Elsevier Inc. All rights reserved.

Browse evaluation of tall shrubs based on direct measurement of a management objective

USGS Publications Warehouse

Keigley, R.B.; Frisina, M.R.; Kitchen, Stanley G.; Pendleton, Rosemary L.; Monaco, Thomas A.; Vernon, Jason

2008-01-01

The monitoring of Geyer willow was based on the following management objective: Browsing will prevent fewer than 50 percent of Geyer willow shrubs from growing taller than 3 m . Three questions were addressed: (1) Is browsing a potential factor? (2) If so, can young plants grow taller than 3 meters? (3) If not, is browsing the dominant factor? All shrubs were intensely browsed. With a post-browsing growth rate of 5.0 cm per yr, no shrub could grow 3 m tall. Analyses of stem growth rate excluded dominant roles for climate and plant vigor. Browsing and stem age were the dominant factors that limited growth to 3 m tall.

Stability of DIII-D high-performance, negative central shear discharges

DOE PAGES

Hanson, Jeremy M.; Berkery, John W.; Bialek, James M.; ...

2017-03-20

Tokamak plasma experiments on the DIII-D device demonstrate high-performance, negative central shear (NCS) equilibria with enhanced stability when the minimum safety factor q min exceeds 2, qualitatively confirming theoretical predictions of favorable stability in the NCS regime. The discharges exhibit good confinement with an L-mode enhancement factor H 89 = 2.5, and are ultimately limited by the ideal-wall external kink stability boundary as predicted by ideal MHD theory, as long as tearing mode (TM) locking events, resistive wall modes (RWMs), and internal kink modes are properly avoided or controlled. Although the discharges exhibit rotating TMs, locking events are avoided asmore » long as a threshold minimum safety factor value q min > 2 is maintained. Fast timescale magnetic feedback control ameliorates RWM activity, expanding the stable operating space and allowing access to β N values approaching the ideal-wall limit. Quickly growing and rotating instabilities consistent with internal kink mode dynamics are encountered when the ideal-wall limit is reached. The RWM events largely occur between the no- and ideal-wall pressure limits predicted by ideal MHD. However, evaluating kinetic contributions to the RWM dispersion relation results in a prediction of passive stability in this regime due to high plasma rotation. In addition, the ideal MHD stability analysis predicts that the ideal-wall limit can be further increased to β N > 4 by broadening the current profile. Furthermore, this path toward improved stability has the potential advantage of being compatible with the bootstrap-dominated equilibria envisioned for advanced tokamak (AT) fusion reactors.« less

Stability of DIII-D high-performance, negative central shear discharges

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

Hanson, Jeremy M.; Berkery, John W.; Bialek, James M.

Tokamak plasma experiments on the DIII-D device demonstrate high-performance, negative central shear (NCS) equilibria with enhanced stability when the minimum safety factor q min exceeds 2, qualitatively confirming theoretical predictions of favorable stability in the NCS regime. The discharges exhibit good confinement with an L-mode enhancement factor H 89 = 2.5, and are ultimately limited by the ideal-wall external kink stability boundary as predicted by ideal MHD theory, as long as tearing mode (TM) locking events, resistive wall modes (RWMs), and internal kink modes are properly avoided or controlled. Although the discharges exhibit rotating TMs, locking events are avoided asmore » long as a threshold minimum safety factor value q min > 2 is maintained. Fast timescale magnetic feedback control ameliorates RWM activity, expanding the stable operating space and allowing access to β N values approaching the ideal-wall limit. Quickly growing and rotating instabilities consistent with internal kink mode dynamics are encountered when the ideal-wall limit is reached. The RWM events largely occur between the no- and ideal-wall pressure limits predicted by ideal MHD. However, evaluating kinetic contributions to the RWM dispersion relation results in a prediction of passive stability in this regime due to high plasma rotation. In addition, the ideal MHD stability analysis predicts that the ideal-wall limit can be further increased to β N > 4 by broadening the current profile. Furthermore, this path toward improved stability has the potential advantage of being compatible with the bootstrap-dominated equilibria envisioned for advanced tokamak (AT) fusion reactors.« less

Input and output constraints affecting irrigation development

NASA Astrophysics Data System (ADS)

Schramm, G.

1981-05-01

In many of the developing countries the expansion of irrigated agriculture is used as a major development tool for bringing about increases in agricultural output, rural economic growth and income distribution. Apart from constraints imposed by water availability, the major limitations considered to any acceleration of such programs are usually thought to be those of costs and financial resources. However, as is shown on the basis of empirical data drawn from Mexico, in reality the feasibility and effectiveness of such development programs is even more constrained by the lack of specialized physical and human factors on the input and market limitations on the output side. On the input side, the limited availability of complementary factors such as, for example, truly functioning credit systems for small-scale farmers or effective agricultural extension services impose long-term constraints on development. On the output side the limited availability, high risk, and relatively slow growth of markets for high-value crops sharply reduce the usually hoped-for and projected profitable crop mix that would warrant the frequently high costs of irrigation investments. Three conclusions are drawn: (1) Factors in limited supply have to be shadow-priced to reflect their high opportunity costs in alternative uses. (2) Re-allocation of financial resources from immediate construction of projects to longer-term increase in the supply of scarce, highly-trained manpower resources are necessary in order to optimize development over time. (3) Inclusion of high-value, high-income producing crops in the benefit-cost analysis of new projects is inappropriate if these crops could potentially be grown in already existing projects.

14 CFR 23.337 - Limit maneuvering load factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factors. 23.337... Flight Loads § 23.337 Limit maneuvering load factors. (a) The positive limit maneuvering load factor n... airplanes; or (3) 6.0 for acrobatic category airplanes. (b) The negative limit maneuvering load factor may...

Effect of pH and ionic strength on exposure and toxicity of encapsulated lambda-cyhalothrin to Daphnia magna.

PubMed

Son, Jino; Hooven, Louisa A; Harper, Bryan; Harper, Stacey L

2015-12-15

Encapsulation of pesticide active ingredients in polymers has been widely employed to control the release of poorly water-soluble active ingredients. Given the high dispersibility of these encapsulated pesticides in water, they are expected to behave differently compared to their active ingredients; however, our current understanding of the fate and effects of encapsulated pesticides is still limited. In this study, we employed a central composite design (CCD) to investigate how pH and ionic strength (IS) affect the hydrodynamic diameter (HDD) and zeta potential of encapsulated λ-cyhalothrin and how those changes affect the exposure and toxicity to Daphnia magna. R(2) values greater than 0.82 and 0.84 for HDD and zeta potential, respectively, irrespective of incubation time suggest those changes could be predicted as a function of pH and IS. For HDD, the linear factor of pH and quadratic factor of pH×pH were found to be the most significant factors affecting the change of HDD at the beginning of incubation, whereas the effects of IS and IS×IS became significant as incubation time increased. For zeta potential, the linear factor of IS and quadratic factor of IS×IS were found to be the most dominant factors affecting the change of zeta potential of encapsulated λ-cyhalothrin, irrespective of incubation time. The toxicity tests with D. magna under exposure conditions in which HDD or zeta potential of encapsulated λ-cyhalothrin was maximized or minimized in the overlying water also clearly showed the worst-case exposure condition to D. magna was when the encapsulated λ-cyhalothrin is either stable or small in the overlying water. Our results show that water quality could modify the fate and toxicity of encapsulated λ-cyhalothrin in aquatic environments, suggesting understanding their aquatic interactions are critical in environmental risk assessment. Herein, we discuss the implications of our findings for risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

Tocotrienols: The lesser known form of natural vitamin E

PubMed Central

Patel, Viren; Rink, Cameron; Khanna, Savita; Sen, Chandan K

2014-01-01

A recent and growing body of research has shown that members of this vitamin E family posses unique biologic functions. Tocotrienols have garnered much of this recent attention, and in particular α-tocotrienol has been shown to be the most potent neuroprotective form of vitamin E. Protection exclusively mediated through tocotrienols has been arbitrated to many mechanisms including inhibition of 12-LOX, c-Src, PLA2 and through up-regulation of MRP1. Further, tocotrienols have recently been shown to induce arteriogenesis through induction of TIMP1 and decreased activation of MMP2. However, the unique therapeutic potential of tocotrienols is not limited to neuroprotection. Tocotrienols have been shown to have molecular targets including: apoptotic regulators, cytokines, adhesion molecules, enzymes, kinases, receptors, transcription factors, and growth factors. In spite of this large and unique therapeutic potential, scientific literature on tocotrienols only accounts for approximately 1% of vitamin E research. Given the potential of tocotrienols and relatively scant literature, further investigation is warranted. PMID:22013739

[The benefits of rehabilitation in people with low potential for recuperation].

PubMed

Bisson, Janick; Cantin, Johanne; Lambert, Johanne; Beauregard, Line

2007-12-01

This article presents the story of a young man who sustained severe limitations following a traumatic brain injury. Considering his very slow recovery rate and a virtual absence of contact with the environment, hopes for rehabilitation were deemed very low. He was nevertheless admitted to a rehabilitation institute for a trial period in November of 2000. This trial revealed potential for rehabilitation and daily treatments were undertaken. This young man left the rehabilitation centre two years later capable of new social participation, including attending an adapted school and even taking small trips. The mobilisation of the rehabilitation team, the financial support of the insurance company, the contribution of assistive devices, the support of those around him, collaborations with his community and above all his own motivation were all factors that played a major role in his rehabilitation. This rehabilitation experience brought the team to reflect on factors that determine rehabilitation potential, the notion of significant progress, as well as concepts of quality of life and social participation.

White light Z-scan measurements of ultrafast optical nonlinearity in reduced graphene oxide nanosheets in the 400–700 nm region

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

Perumbilavil, Sreekanth; Sankar, Pranitha; Priya Rose, T.

Wavelength dispersion of optical power limiting is an important factor to be considered while designing potential optical limiters for laser safety applications. We report the observation of broadband, ultrafast optical limiting in reduced graphene oxide (rGO), measured by a single open aperture Z-scan using a white light continuum (WLC) source. WLC Z-scan is fast when the nonlinearity is to be measured over broad wavelength ranges, and it obviates the need for an ultrafast tunable laser making it cost-economic compared to conventional Z-scan. The nonlinearity arises from nondegenerate two-photon absorption, owing mostly to the crystallinity and extended π conjugation of rGO.

Carbon Sequestration in Unconventional Reservoirs: Advantages and Limitations

NASA Astrophysics Data System (ADS)

Zakharova, N. V.; Slagle, A. L.; Goldberg, D.

2014-12-01

To make a significant impact on anthropogenic CO2 emissions, geologic carbon sequestration would require thousands of CO2 repositories around the world. Unconventional reservoirs, such as igneous rocks and fractured formations, may add substantial storage capacity and diversify CO2 storage options. In particular, basaltic rocks represent a promising target due to their widespread occurrence, potentially suitable reservoir structure and high reactivity with CO2, but a comprehensive evaluation of worldwide CO2 sequestration capacity in unconventional reservoirs is lacking. In this presentation we summarize available data on storage potential of basaltic rocks and fractured formations illustrated by field examples from the Columbia River Basalt, the Newark Rift Basin and IODP Site 1256, and discuss potential limiting factors, such as effective porosity and the risk of inducing earthquakes by CO2 injections. Large Igneous Provinces (LIPs), low-volume flows and intrusions, and ocean floor basalt represent three general classes of basaltic reservoirs, each characterized by different structure and storage capacity. Oceanic plateaus and LIPs are projected to have the highest CO2 storage capacity, on the order of thousands gigatons (Gt) per site, followed by continental LIPs and ocean floor basalts (hundreds to thousands Gt per site). Isolated basalt flows and intrusions are likely to offer only low- to moderate-capacity options. An important limiting factor on CO2 injection volumes and rates is the risk of inducing earthquakes by increasing pore pressure in the subsurface. On continents, available in situ stress analysis suggests that local stress perturbations at depth may create relaxed stress conditions, allowing for pore pressure increase without reactivating fractures and faults. Remote storage sites on oceanic plateaus and below the seafloor are advantageous due to low impact of potential seismic and/or leakage events. Other effects, such as thermal stresses created by temperature difference between injected fluid and the host formation, may be particularly important for reservoir stability in high-temperature offshore locations. Overall, unconventional reservoirs in offshore locations offer the potential benefits of vast and safe storage for captured CO2 emissions.

Military Service, Deployments, and Exposures in Relation to Amyotrophic Lateral Sclerosis Etiology and Survival

PubMed Central

Beard, John D.; Kamel, Freya

2015-01-01

Rates of amyotrophic lateral sclerosis (ALS) have been reported to be higher among US military veterans, who currently number more than 21 million, but the causal factor(s) has not been identified. We conducted a review to examine the weight of evidence for associations between military service, deployments, and exposures and ALS etiology and survival. Thirty articles or abstracts published through 2013 were reviewed. Although the current evidence suggests a positive association with ALS etiology, it is too limited to draw firm conclusions regarding associations between military service and ALS etiology or survival. Some evidence suggests that deployment to the 1990–1991 Persian Gulf War may be associated with ALS etiology, but there is currently no strong evidence that any particular military exposure is associated with ALS etiology. Future studies should address the limitations of previous ones, such as reliance on mortality as a surrogate for incidence, a dearth of survival analyses, lack of clinical data, low statistical power, and limited exposure assessment. The Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis (GENEVA) Study is one such study, but additional research is needed to determine whether military-related factors are associated with ALS and to assess potential prevention strategies. PMID:25365170

Perspectives on New Synthetic Curcumin Analogs and their Potential Anticancer Properties

PubMed Central

Vyas, Alok; Dandawate, Prasad; Padhye, Subhash; Ahmad, Aamir; Sarkar, Fazlul

2013-01-01

Curcumin is the active component of dried rhizome of Curcuma longa, a perennial herb belonging to ginger family, cultivated extensively in south and southeastern tropical Asia. It is widely consumed in the Indian subcontinent, south Asia and Japan in traditional food recipes. Extensive research over last few decades has shown that curcumin is a potent anti-inflammatory agent with powerful therapeutic potential against a variety of cancers. It suppresses proliferation and metastasis of human tumors through regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases and other enzymes. It induces apoptotic cell death and also inhibits proliferation of cancer cells by cell cycle arrest. Pharmacokinetic data has shown that curcumin undergoes rapid metabolism leading to glucuronidation and sulfation in the liver and excretion in the feces, which accounts for its poor systemic bioavailability. The compound has, therefore, been formulated and administered using different drug delivery systems such as liposomes, micelles, polysaccharides, phospholipid complexes and nanoparticles that can overcome the limitation of bioavailability to some extent. Attempts to avoid rapid metabolism of curcumin until now have been met with limited success. This has prompted researchers to look for new synthetic curcumin analogs in order to overcome the drawbacks of limited bioavailability and rapid metabolism, and gain efficacy with reduced toxicity. In this review we provide a summarized account of novel synthetic curcumin formulations and analogs, and the recent progress in the field of cancer prevention and treatment. PMID:23116312

Perspectives on new synthetic curcumin analogs and their potential anticancer properties.

PubMed

Vyas, Alok; Dandawate, Prasad; Padhye, Subhash; Ahmad, Aamir; Sarkar, Fazlul

2013-01-01

Curcumin is the active component of dried rhizome of Curcuma longa, a perennial herb belonging to ginger family, cultivated extensively in south and southeastern tropical Asia. It is widely consumed in the Indian subcontinent, south Asia and Japan in traditional food recipes. Extensive research over last few decades has shown that curcumin is a potent anti-inflammatory agent with powerful therapeutic potential against a variety of cancers. It suppresses proliferation and metastasis of human tumors through regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases and other enzymes. It induces apoptotic cell death and also inhibits proliferation of cancer cells by cell cycle arrest. Pharmacokinetic data has shown that curcumin undergoes rapid metabolism leading to glucuronidation and sulfation in the liver and excretion in the feces, which accounts for its poor systemic bioavailability. The compound has, therefore, been formulated and administered using different drug delivery systems such as liposomes, micelles, polysaccharides, phospholipid complexes and nanoparticles that can overcome the limitation of bioavailability to some extent. Attempts to avoid rapid metabolism of curcumin until now have been met with limited success. This has prompted researchers to look for new synthetic curcumin analogs in order to overcome the drawbacks of limited bioavailability and rapid metabolism, and gain efficacy with reduced toxicity. In this review we provide a summarized account of novel synthetic curcumin formulations and analogs, and the recent progress in the field of cancer prevention and treatment.

Influence of postmortem time on the outcome of blood cultures among cadaveric tissue donors.

PubMed

Saegeman, V; Verhaegen, J; Lismont, D; Verduyckt, B; De Rijdt, T; Ectors, N

2009-02-01

Tissue banks provide tissues of human cadaver donors for transplantation. The maximal time limit for tissue retrieval has been set at 24 h postmortem. This study aimed at evaluating the evidence for this limit from a microbiological point of view. The delay of growth in postmortem blood cultures, the identification of the species isolated and clinical/environmental factors were investigated among 100 potential tissue donors. No significant difference was found in the rate of donors with grown blood cultures within (25/65=38%) compared with after (24/65=37%) 24 h of death. Coagulase-negative staphylococci and gastro-intestinal microorganisms were isolated within and after 24 h of death. Two factors--antimicrobial therapy and "delay before body cooling"--were significantly inversely related with donors' blood culture results. From a microbiological point of view, there is no evidence for avoiding tissue retrieval among donors after 24 h of death.

The hormone prolactin is a novel, endogenous trophic factor able to regulate reactive glia and to limit retinal degeneration.

PubMed

Arnold, Edith; Thebault, Stéphanie; Baeza-Cruz, German; Arredondo Zamarripa, David; Adán, Norma; Quintanar-Stéphano, Andrés; Condés-Lara, Miguel; Rojas-Piloni, Gerardo; Binart, Nadine; Martínez de la Escalera, Gonzalo; Clapp, Carmen

2014-01-29

Retinal degeneration is characterized by the progressive destruction of retinal cells, causing the deterioration and eventual loss of vision. We explored whether the hormone prolactin provides trophic support to retinal cells, thus protecting the retina from degenerative pressure. Inducing hyperprolactinemia limited photoreceptor apoptosis, gliosis, and changes in neurotrophin expression, and it preserved the photoresponse in the phototoxicity model of retinal degeneration, in which continuous exposure of rats to bright light leads to retinal cell death and retinal dysfunction. In this model, the expression levels of prolactin receptors in the retina were upregulated. Moreover, retinas from prolactin receptor-deficient mice exhibited photoresponsive dysfunction and gliosis that correlated with decreased levels of retinal bFGF, GDNF, and BDNF. Collectively, these data unveiled prolactin as a retinal trophic factor that may regulate glial-neuronal cell interactions and is a potential therapeutic molecule against retinal degeneration.

Health-Related Quality of Life Among US Workers: Variability Across Occupation Groups.

PubMed

Shockey, Taylor M; Zack, Matthew; Sussell, Aaron

2017-08-01

To examine the health-related quality of life among workers in 22 standard occupation groups using data from the 2013-2014 US Behavioral Risk Factor Surveillance System. We examined the health-related quality of life measures of self-rated health, frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days by occupation group for 155 839 currently employed adults among 17 states. We performed multiple logistic regression analyses that accounted for the Behavioral Risk Factor Surveillance System's complex survey design to obtain prevalence estimates adjusted for potential confounders. Among all occupation groups, the arts, design, entertainment, sports, and media occupation group reported the highest adjusted prevalence of frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days. The personal care and service occupation group had the highest adjusted prevalence for fair or poor self-rated health. Workers' jobs affect their health-related quality of life.

Naftidrofuryl affects neurite regeneration by injured adult auditory neurons.

PubMed

Lefebvre, P P; Staecker, H; Moonen, G; van de Water, T R

1993-07-01

Afferent auditory neurons are essential for the transmission of auditory information from Corti's organ to the central auditory pathway. Auditory neurons are very sensitive to acute insult and have a limited ability to regenerate injured neuronal processes. Therefore, these neurons appear to be a limiting factor in restoration of hearing function following an injury to the peripheral auditory receptor. In a previous study nerve growth factor (NGF) was shown to stimulate neurite repair but not survival of injured auditory neurons. In this study, we have demonstrated a neuritogenesis promoting effect of naftidrofuryl in an vitro model for injury to adult auditory neurons, i.e. dissociated cell cultures of adult rat spiral ganglia. Conversely, naftidrofuryl did not have any demonstrable survival promoting effect on these in vitro preparations of injured auditory neurons. The potential uses of this drug as a therapeutic agent in acute diseases of the inner ear are discussed in the light of these observations.

Hawaii's public mental health system.

PubMed

VanderVoort, Debra J

2005-03-01

The following article addresses the nature of and problems with the public mental health system in Hawaii. It includes a brief history of Hawaii's public mental health system, a description and analysis of this system, economic factors affecting mental health, as well as a needs assessment of the elderly, individuals with severe mental illness, children and adolescents, and ethnically diverse individuals. In addition to having the potential to increase suicide rates and unnecessarily prolong personal suffering, problems in the public mental health system such as inadequate services contribute to an increase in social problems including, but not limited to, an increase in crime rates (e.g., domestic violence, child abuse), divorce rates, school failure, and behavioral problems in children. The population in need of mental health services in Hawaii is under served, with this inadequacy of services due to economic limitations and a variety of other factors.

Lockheed Martin T-Rex: Preliminary report

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

NONE

1997-07-31

T-Rex is a robot which may be used in toxic or flammable environments. The assessment of the T-Rex conducted at the Lockheed Martin facility was limited in its scope. The scope of the assessment was directed by the type of equipment being used and the amount of accessibility to the equipment. Due to severe time constraints--the assessment was conducted in one day--human factors interface activities were limited. This should be considered a preliminary assessment. This report covers aspects of the technology that were available to the assessment team. Recommendations for future evaluation of this technology are also included. The contentsmore » are as follows: Electrical Considerations; General Electrical Consideration; Trailing Cables; Grounding; Surface High Voltage Distribution; Low and Medium Voltage Alternating Current Circuits; Potential for Harmful Human Factor Incidents and Enterprise Disablement; Exclusion Zone Emergency Maintenance; and Recommendations.« less

Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

PubMed

Wang, Ruobing; Sun, Qinglei; Xia, Fangzhou; Chen, Zeli; Wu, Jiangchun; Zhang, Yuelu; Xu, Jiajun; Liu, Lin

2017-06-01

Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3β, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase activity and ATP content, in retinas with ONC. Taken together, methane treatment promotes RGC survival and limits retinal mitochondrial dysfunction against ONC insult. Methane can be a potential neuroprotective agent for traumatic and glaucomatous neurodegeneration. Copyright © 2017. Published by Elsevier Ltd.

Nintedanib: evidence for its therapeutic potential in idiopathic pulmonary fibrosis

PubMed Central

Inomata, Minoru; Nishioka, Yasuhiko; Azuma, Arata

2015-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis. The molecular mechanisms involved in the progression of IPF are not fully understood; however, the platelet-derived growth factor (PDGF)/PDGF receptor pathway is thought to play a critical role in fibrogenesis of the lungs. Other growth factors, including fibroblast growth factor and vascular endothelial growth factor, are also thought to contribute to the pathogenesis of pulmonary fibrosis. Nintedanib is an inhibitor of multiple tyrosine kinases, including receptors for PDGF, fibroblast growth factor, and vascular endothelial growth factor. In the Phase II TOMORROW trial, treatment with 150 mg of nintedanib twice daily showed a trend to slow the decline in lung function and significantly decrease acute exacerbations in patients with IPF, while showing an acceptable safety profile. The Phase III INPULSIS trials demonstrated a significant decrease in the annual rate of decline in forced vital capacity in IPF patients treated with 150 mg nintedanib twice daily. In the INPULSIS-2 trial, the time to the first acute exacerbation significantly increased in IPF patients who were treated with 150 mg of nintedanib twice daily. Pirfenidone, another antifibrotic drug, was shown to limit the decline in pulmonary function in patients with IPF in the ASCEND trial. Combination therapy with nintedanib and pirfenidone is anticipated, although further evaluation of its long-term safety is needed. There is limited evidence for the safety of the combination therapy although a Phase II trial conducted in Japan demonstrated that combination therapy with nintedanib and pirfenidone was tolerable for 1 month. Available antifibrotic agents (ie, pirfenidone and N-acetylcysteine) have limited efficacy as single therapies for IPF; therefore, further study of combination therapy with antifibrotic agents is needed. PMID:26346347

Factors Associated With Exercise Behavior in People With Parkinson Disease

PubMed Central

Cavanaugh, James T.; Earhart, Gammon M.; Ford, Matthew P.; Foreman, K. Bo; Fredman, Lisa; Boudreau, Jennifer K.; Dibble, Leland E.

2011-01-01

Background The benefits of exercise for reducing disability in people with Parkinson disease (PD) are becoming more evident. Optimal benefit, however, requires regular and sustained participation. Factors associated with engaging in regular exercise have received little scientific scrutiny in people with PD. Objective The purpose of this study was to explore factors associated with exercise behavior in patients with PD using the International Classification of Functioning, Disability and Health (ICF) as a guiding framework. Design This was a cross-sectional study. Methods The participants in this study were 260 patients with PD from 4 institutions. Participants were designated as “exercisers” or “nonexercisers” based on responses to the Stages of Readiness to Exercise Questionnaire. Exercise status was validated using the Physical Activity Scale for the Elderly and an activity monitor. Factors potentially associated with exercise behavior included measures of body structure and function, activity, participation, environmental factors, and personal factors. Their relative contributions were analyzed using logistic regression and quantified with odds ratios. Results One hundred sixty-four participants (63%) were designated as exercisers. Participants with high self-efficacy were more than twice as likely to engage in regular exercise than those with low self-efficacy (adjusted odds ratio=2.34, 95% confidence interval=1.30–4.23). College educated and older participants also were more likely to exercise. Disabling influences of impairments, activity limitations, and participation restrictions were not associated with exercise behavior. Limitations The cross-sectional nature of the study limited the ability to make causal inferences. Conclusions Self-efficacy, rather than disability, appears to be strongly associated with whether ambulatory, community-dwelling people with PD exercise regularly. The results of this study suggest that physical therapists should include strategies to increase exercise self-efficacy when designing patient intervention programs for patients with PD. PMID:22003171

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

Checchin, Mattia

Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described inmore » detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the superheating field, which is intimately correlated to the penetration of magnetic flux vortices in the material. Experimental data for N-doped cavities suggest that uniform Ginzburg-Landau parameter cavities are statistically limited by the lower critical field, in terms of accelerating gradient. By introducing a Ginzburg-Landau parameter profile at the cavity rf surface--dirty layer--the accelerating gradient of superconducting resonators can be enhanced. The description of the physics behind the accelerating gradient enhancement as a consequence of the dirty layer is carried out by solving numerically the Ginzburg-Landau equations for the layered system. The enhancement is showed to be promoted by the higher energy barrier to vortex penetration, and by the enhanced lower critical field. Another serious threat to the quality factor during the cavity operation is the extra dissipation introduced by the quench. Such quality factor degradation mechanism due to the quench, is generated by the trapping of external magnetic flux at quench spot. The purely extrinsic origin of such extra dissipation is proven by the impossibility of decrease the quality factor by quenching in a magnetic field-free environment. Also, a clear relation of the dissipation introduced by quenching to the orientation of the applied magnetic field is observed. The full recover of the quality factor by re-quenching in compensated field is possible when the trapped flux at the quench spot is modest. On the contrary, when the trapped magnetic flux is too large, the quality factor degradation may become irreversible by this technique, likely due to the outward flux migration beyond the normal zone opening during the quench.« less

Mechanisms of resistance to irreversible epidermal growth factor receptor tyrosine kinase inhibitors and therapeutic strategies in non-small cell lung cancer

PubMed Central

Xu, Jing; Wang, Jinghui; Zhang, Shucai

2017-01-01

Epidermal growth factor receptor (EGFR) T790M mutation is the most frequent mechanism which accounts for about 60% of acquired resistance to first-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients harboring EGFR activating mutations. Irreversible EGFR-TKIs which include the second-generation and third-generation EGFR-TKIs are developed to overcome T790M mediated resistance. The second-generation EGFR-TKIs inhibit the wide type (WT) EGFR combined with dose-limiting toxicity which limits its application in clinics, while the development of third-generation EGFR-TKIs brings inspiring efficacy either in vitro or in vivo. The acquired resistance, however, will also occur and limit their response. Understanding the mechanisms of resistance to irreversible EGFR-TKIs plays an important role in the choice of subsequent treatment. In this review, we show the currently known mechanisms of resistance which can be summarized as EGFR dependent and independent mechanisms and potential therapeutic strategies to irreversible EGFR-TKIs. PMID:29163853

Electronic consent channels: preserving patient privacy without handcuffing researchers.

PubMed

Shelton, Robert H

2011-02-09

Advances in health information technology and electronic medical records have the tremendous potential to accelerate translational and clinical research. However, privacy concerns threaten to be a rate-limiting factor. By recognizing and responding to patient privacy concerns, policy-makers, researchers, and information technology leaders have the opportunity to transform trial recruitment and make it safer to electronically locate and convey sensitive health information.

Integrating Design Disciplines: Understanding the Potential for and Factors Affecting the Success of Interdisciplinary Design Education for Architecture and Landscape Architecture

ERIC Educational Resources Information Center

Koo, Tae Seo

2012-01-01

Interdisciplinary design education is becoming more important as design disciplines need various perspectives and solutions. However, only a limited amount of research has been done in regard to interdisciplinary design education. The goal of this study is to begin to answer the question about how designers and researchers develop and improve…

Quest to identify geochemical risk factors associated with chronic kidney disease of unknown etiology (CKDu) in an endemic region of Sri Lanka-a multimedia laboratory analysis of biological, food, and environmental samples.

PubMed

Levine, Keith E; Redmon, Jennifer Hoponick; Elledge, Myles F; Wanigasuriya, Kamani P; Smith, Kristin; Munoz, Breda; Waduge, Vajira A; Periris-John, Roshini J; Sathiakumar, Nalini; Harrington, James M; Womack, Donna S; Wickremasinghe, Rajitha

2016-10-01

The emergence of a new form of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka's North Central Province (NCP) has become a catastrophic health crisis. CKDu is characterized as slowly progressing, irreversible, and asymptomatic until late stages and, importantly, not attributed to diabetes, hypertension, or other known risk factors. It is postulated that the etiology of CKDu is multifactorial, involving genetic predisposition, nutritional and dehydration status, exposure to one or more environmental nephrotoxins, and lifestyle factors. The objective of this limited geochemical laboratory analysis was to determine the concentration of a suite of heavy metals and trace element nutrients in biological samples (human whole blood and hair) and environmental samples (drinking water, rice, soil, and freshwater fish) collected from two towns within the endemic NCP region in 2012 and 2013. This broad panel, metallomics/mineralomics approach was used to shed light on potential geochemical risk factors associated with CKDu. Based on prior literature documentation of potential nephrotoxins that may play a role in the genesis and progression of CKDu, heavy metals and fluoride were selected for analysis. The geochemical concentrations in biological and environmental media areas were quantified. Basic statistical measurements were subsequently used to compare media against applicable benchmark values, such as US soil screening levels. Cadmium, lead, and mercury were detected at concentrations exceeding US reference values in many of the biological samples, suggesting that study participants are subjected to chronic, low-level exposure to these elements. Within the limited number of environmental media samples, arsenic was determined to exceed initial risk screening and background concentration values in soil, while data collected from drinking water samples reflected the unique hydrogeochemistry of the region, including the prevalence of hard or very hard water, and fluoride, iron, manganese, sodium, and lead exceeding applicable drinking water standards in some instances. Current literature suggests that the etiology of CKDu is likely multifactorial, with no single biological or hydrogeochemical parameter directly related to disease genesis and progression. This preliminary screening identified that specific constituents may be present above levels of concern, but does not compare results against specific kidney toxicity values or cumulative risk related to a multifactorial disease process. The data collected from this limited investigation are intended to be used in the subsequent study design of a comprehensive and multifactorial etiological study of CKDu risk factors that includes sample collection, individual surveys, and laboratory analyses to more fully evaluate the potential environmental, behavioral, genetic, and lifestyle risk factors associated with CKDu.

Health status, activity limitations, and disability in work and housework among Latinos and non-Latinos with arthritis: an analysis of national data.

PubMed

Abraído-Lanza, Ana F; White, Kellee; Armbrister, Adria N; Link, Bruce G

2006-06-15

To document disparities in health status, activity limitations, and disability in work and housework between Latinos and non-Latino whites with arthritis. We examined whether sociodemographic factors (age, income, and education) account for the disparities between the ethnic groups, and whether comorbid conditions, disease duration, health care utilization, and functional abilities predict health status, activity limitations, and work and housework disability after controlling for sociodemographic variables. We analyzed data from the Condition file of the 1994 National Health Interview Survey on Disability, Phase I. The risk of worse health, activity limitations, and work and housework disability was >2 times greater among Latinos compared with non-Latino whites. In the regression models accounting for potential confounders, Latino ethnicity remained significantly associated with poorer health status, but not activity limitations or disability in work or housekeeping. Of the socioeconomic status variables, education had a significant protective effect on work disability and health status. Comorbid conditions and health care utilization increased the likelihood of worse health, activity limitations, and work disability. Limitations in physical function were associated with poorer health and disability in work and homemaking. Social status differences between Latinos and non-Latinos may account for disparities in activity limitations and disability in work and housework. Education may provide various health benefits, including access to a range of occupations that do not require physical demands. The findings help to address the great gap in knowledge concerning factors related to the health and disability status of Latinos with arthritis.

Drivers of spatial heterogeneity in nitrogen processing among three alpine plant communities in the Rocky Mountains

NASA Astrophysics Data System (ADS)

Churchill, A. C.; Beers, A.; Grinath, J.; Bowman, W. D.

2017-12-01

Nitrogen cycling across the globe has been fundamentally altered due to regional elevated N deposition and there is a cascade of ecosystem consequences including shifts in species composition, eutrophication, and soil acidification. Making predictions that encompass the factors that drive these ecosystem changes has frequently been limited to single ecosystem types, or areas with fairly homogenous abiotic conditions. The alpine is an ecosystem type that exhibits changes under relatively low levels of N depositions due to short growing seasons and shallow soils limiting N storage. While recent work provided estimates for the magnitude of N associated with ecosystem changes, less is known about the within-site factors that may interact to stabilize or amplify the differential response of N pools under future conditions of resource deposition. To examine numerous potential within-site and regional factors (both biotic and abiotic) affecting ecosystem N pools we examined the relationship between those factors and a suite of ecosystem pools of N followed by model selection procedures and structural equation modelling. Measurements were conducted at Niwot Ridge Long Term Ecological Research site and in Rocky Mountain National Park in three distinct alpine meadow ecosystems (dry, moist, and wet meadows). These meadows span a moisture gradient as well as plant community composition, thereby providing high variability of potential biotic and abiotic drivers across small spatial scales in the alpine. In general, regional scale abiotic factors such as site levels of annual average N deposition or precipitation were poor predictors of seasonal pools of N, while spring soil water pools of N were negatively correlated with elevation. Models containing multiple abiotic and biotic drivers, however, were best at predicting soil and plant pools of N across the two sites. Future analysis will include highlight interactions among with-site factors affecting N pools in the alpine using structural equation modelling to statistically examine the bidirectional relationship between plant communities and soil pools of N.

IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty.

PubMed

Maggio, Marcello; De Vita, Francesca; Lauretani, Fulvio; Buttò, Valeria; Bondi, Giuliana; Cattabiani, Chiara; Nouvenne, Antonio; Meschi, Tiziana; Dall'Aglio, Elisabetta; Ceda, Gian Paolo

2013-10-21

The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects.

Quantifying potential yield and water-limited yield of summer maize in the North China Plain

NASA Astrophysics Data System (ADS)

Jiang, Mingnuo; Liu, Chaoshun; Chen, Maosi

2017-09-01

The North China Plain is a major food producing region in China, and climate change could pose a threat to food production in the region. Based on China Meteorological Forcing Dataset, simulating the growth of summer maize in North China Plain from 1979 to 2015 with the regional implementation of crop growth model WOFOST. The results showed that the model can reflect the potential yield and water-limited yield of Summer Maize in North China Plain through the calibration and validation of WOFOST model. After the regional implementation of model, combined with the reanalysis data, the model can better reproduce the regional history of summer maize yield in the North China Plain. The yield gap in Southeastern Beijing, southern Tianjin, southern Hebei province, Northwestern Shandong province is significant, these means the water condition is the main factor to summer maize yield in these regions.

Uncertainty, learning, and the optimal management of wildlife

USGS Publications Warehouse

Williams, B.K.

2001-01-01

Wildlife management is limited by uncontrolled and often unrecognized environmental variation, by limited capabilities to observe and control animal populations, and by a lack of understanding about the biological processes driving population dynamics. In this paper I describe a comprehensive framework for management that includes multiple models and likelihood values to account for structural uncertainty, along with stochastic factors to account for environmental variation, random sampling, and partial controllability. Adaptive optimization is developed in terms of the optimal control of incompletely understood populations, with the expected value of perfect information measuring the potential for improving control through learning. The framework for optimal adaptive control is generalized by including partial observability and non-adaptive, sample-based updating of model likelihoods. Passive adaptive management is derived as a special case of constrained adaptive optimization, representing a potentially efficient suboptimal alternative that nonetheless accounts for structural uncertainty.

The cost of cancer care: Part II.

PubMed

Eagle, David

2012-11-01

The rising cost of cancer treatment competes with the availability of effective therapy as a limiting factor in our war on cancer. Specific programs are being developed that have the potential to slow the growth in spending on oncology care. The Affordable Care Act includes provisions for containing healthcare costs, such as accountable care organizations and the Independent Payment Advisory Board. Within oncology, specific programs have emerged, including clinical pathways, episode-of-care based payment arrangements, and the oncology medical home. All models of cost containment have strengths and weaknesses. Outside of the United States, explicit rationing exists' through national health technology assessment organizations. Excessive demands on physicians to limit spending at the bedside could potentially create conflicts with their professional responsibility to patients. While spending for cancer care in the US is high, its "worth" is ultimately a societal decision. Recent economic modeling suggests that we may be achieving value for the money we spend.

Mechanisms of resistance to anti-human epidermal growth factor receptor 2 agents in breast cancer.

PubMed

Mukohara, Toru

2011-01-01

Approximately 20% of breast cancers are characterized by overexpression of human epidermal growth factor receptor 2 (HER2) protein and associated gene amplification, and the receptor tyrosine kinase is believed to play a critical role in the pathogenesis of these tumors. The development and implementation of trastuzumab, a humanized monoclonal antibody against the extracellular domain of HER2 protein, has significantly improved treatment outcomes in patients with HER2-overexpressing breast cancer. However, despite this clinical usefulness, unmet needs for better prediction of trastuzumab's response and overcoming primary and acquired resistance remain. In this review, we discuss several potential mechanisms of resistance to trastuzumab that have been closely studied over the last decade. Briefly, these mechanisms include: impaired access of trastuzumab to HER2 by expression of extracellular domain-truncated HER2 (p95 HER2) or overexpression of MUC4; alternative signaling from insulin-like growth factor-1 receptor, other epidermal growth factor receptor family members, or MET; aberrant downstream signaling caused by loss of phosphatase and tensin homologs deleted from chromosome 10 (PTEN), PIK3CA mutation, or downregulation of p27; or FCGR3A polymorphisms. In addition, we discuss potential strategies for overcoming resistance to trastuzumab. Specifically, the epidermal growth factor receptor/HER2 tyrosine kinase inhibitor lapatinib partially overcame trastuzumab resistance in a clinical setting, so its efficacy results and limited data regarding potential mechanisms of resistance to the drug are also discussed. © 2010 Japanese Cancer Association.

Musculoskeletal pain and limitations in work ability in Swedish marines: a cross-sectional survey of prevalence and associated factors

PubMed Central

Monnier, Andreas; Larsson, Helena; Djupsjöbacka, Mats; Brodin, Lars-Åke; Äng, Björn O

2015-01-01

Objectives To estimate the prevalence of self-rated musculoskeletal pain and pain limiting work ability in Swedish Armed Forces (SAF) marines, and to study factors potentially associated with pain limiting work ability for the most prevalent pain regions reported. Design Population-based, cross-sectional survey. Participants There were 272 SAF marines from the main marine battalion in Sweden included in the study. Outcomes Self-assessed musculoskeletal pain and pain limiting the marines' work ability within a 6-month period, as obtained from structured questionnaires. The association of individual, health and work-related factors with musculoskeletal pain limiting work ability was systematically regressed with multiple logistic models, estimating OR and 95% CI. Results Musculoskeletal pain and pain limiting work ability were most common in the back, at 46% and 20%, and lower extremities at 51% and 29%, respectively. Physical training ≤1 day/week (OR 5.3, 95% CI 1.7 to 16.8); body height ≤1.80 m (OR 5.0, 95% CI 1.6 to 15.1) and ≥1.86 m (OR 4.4, 95% CI 1.4 to 14.1); computer work 1/4 of the working day (OR 3.2, 95% CI 1.0 to 10.0) and ≥1/2 (OR 3.3, 95% CI 1.1 to 10.1) of the working day were independently associated with back pain limiting work ability. None of the studied variables emerged significantly associated with such pain for the lower extremities. Conclusions Our findings show that musculoskeletal pain and resultant limitations in work ability are common in SAF marines. Low frequency of physical training emerged independently associated with back pain limiting work ability. This suggests that marines performing physical training 1 day per week or less are suitable candidates for further medical evaluation and secondary preventive actions. While also associated, body height and computer work need further exploration as underlying mechanisms for back pain limiting work ability. Further prospective studies are necessary to clarify the direction of causality. PMID:26443649

Life stage and species identity affect whether habitat subsidies enhance or simply redistribute consumer biomass.

PubMed

Keller, Danielle A; Gittman, Rachel K; Bouchillon, Rachel K; Fodrie, F Joel

2017-10-01

Quantifying the response of mobile consumers to changes in habitat availability is essential for determining the degree to which population-level productivity is habitat limited rather than regulated by other, potentially density-independent factors. Over landscape scales, this can be explored by monitoring changes in density and foraging as habitat availability varies. As habitat availability increases, densities may: (1) decrease (unit-area production decreases; weak habitat limitation); (2) remain stable (unit-area production remains stable; habitat limitation) or (3) increase (unit-area production increases; strong habitat limitation). We tested the response of mobile estuarine consumers over 5 months to changes in habitat availability in situ by comparing densities and feeding rates on artificial reefs that were or were not adjacent to neighbouring artificial reefs or nearby natural reefs. Using either constructed or natural reefs to manipulate habitat availability, we documented threefold density decreases among juvenile stone crabs as habitat increased (i.e. weak habitat imitation). However, for adult stone crabs, density remained stable across treatments, demonstrating that habitat limitation presents a bottleneck in this species' later life history. Oyster toadfish densities also did not change with increasing habitat availability (i.e. habitat limitation), but densities of other cryptic fishes decreased as habitat availability increased (i.e. weak limitation). Feeding and abundance data suggested that some mobile fishes experience habitat limitation, or, potentially in one case, strong limitation across our habitat manipulations. These findings of significant, community-level habitat limitation provide insight into how global declines in structurally complex estuarine habitats may have reduced the fishery production of coastal ecosystems. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Brain-derived neurotrophic factor (BDNF) serum basal levels is not affected by power training in mobility-limited older adults - A randomized controlled trial.

PubMed

Hvid, L G; Nielsen, M K F; Simonsen, C; Andersen, M; Caserotti, P

2017-07-01

Brain-derived neurotrophic factor (BDNF) is a potential important factor involved in neuroplasticity, and may be a mediator for eliciting adaptations in neuromuscular function and physical function in older individuals following physical training. As power training taxes the neural system to a very high extent, it may be particularly effective in terms of eliciting increases in systemic BDNF levels. We examined the effects of 12weeks of power training on mature BDNF (mBDNF) and total BDNF (tBDNF) in mobility-limited older adults from the Healthy Ageing Network of Competence (HANC) study. We included 47 older men and women: n=22 in the training group (TG: progressive high intensity power training, 2 sessions per week; age 82.7±5.4years, 55% women) and n=25 in the control group (CG: no interventions; age 82.2±4.5years, 76% women). Following overnight fasting, basal serum levels of mBDNF and tBDNF were assessed (human ELISA kits) at baseline and post-intervention. At baseline, mBDNF and tBDNF levels were comparable in the two groups, TG and CG. Post-intervention, no significant within-group or between-group changes were observed in mBDNF or tBDNF. Moreover, when divided into responder tertiles based upon changes in mBDNF and tBDNF (i.e. decliners, maintainers, improvers), respectively, comparable findings were observed for TG and CG. Altogether, basal systemic levels of serum mBDNF and tBDNF are not affected in mobility-limited older adults following 12-weeks of power training, and do not appear to be a major mechanistic factor mediating neuroplasticity in mobility-limited older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

Two-Stage Design Method for Enhanced Inductive Energy Transmission with Q-Constrained Planar Square Loops.

PubMed

Eteng, Akaa Agbaeze; Abdul Rahim, Sharul Kamal; Leow, Chee Yen; Chew, Beng Wah; Vandenbosch, Guy A E

2016-01-01

Q-factor constraints are usually imposed on conductor loops employed as proximity range High Frequency Radio Frequency Identification (HF-RFID) reader antennas to ensure adequate data bandwidth. However, pairing such low Q-factor loops in inductive energy transmission links restricts the link transmission performance. The contribution of this paper is to assess the improvement that is reached with a two-stage design method, concerning the transmission performance of a planar square loop relative to an initial design, without compromise to a Q-factor constraint. The first stage of the synthesis flow is analytical in approach, and determines the number and spacing of turns by which coupling between similar paired square loops can be enhanced with low deviation from the Q-factor limit presented by an initial design. The second stage applies full-wave electromagnetic simulations to determine more appropriate turn spacing and widths to match the Q-factor constraint, and achieve improved coupling relative to the initial design. Evaluating the design method in a test scenario yielded a more than 5% increase in link transmission efficiency, as well as an improvement in the link fractional bandwidth by more than 3%, without violating the loop Q-factor limit. These transmission performance enhancements are indicative of a potential for modifying proximity HF-RFID reader antennas for efficient inductive energy transfer and data telemetry links.

The mediating role of the home environment in relation to parental educational level and preschool children's screen time: a cross-sectional study.

PubMed

Määttä, Suvi; Kaukonen, Riikka; Vepsäläinen, Henna; Lehto, Elviira; Ylönen, Anna; Ray, Carola; Erkkola, Maijaliisa; Roos, Eva

2017-09-02

Previous studies suggest that preschoolers from low socioeconomic backgrounds engage in more screen time. Still, the factors in the social and physical home environment driving these differences in preschool children's screen time are poorly understood. This study examines potential home environment mediators in the associations between parental educational level and preschoolers' screen time. A total of 864 children aged 3-6 years and their parents participated in a cross-sectional DAGIS study in 2015-2016. Parents recorded their children's screen time in a diary (N = 823). For the analyses, the daily average screen time at home was calculated. Parental questionnaires (N = 808) assessed educational level and eight social and physical environment factors in the home (i.e., descriptive norm for children's screen time, parental screen use in front of children, parental importance for limiting children's screen time, parental attitude toward societal pressures for children's screen time, access to screens at home, parental self-efficacy for limiting children's screen time, satisfaction of children's screen time, and rules for limiting children's screen time). Parental education was grouped into low, middle, and high education. The associations were tested by conducting mediation analyses adjusted by season and children's sex and age. The significant mediators in the single-mediator models were included in the final multiple-mediator models. Of the potential eight mediators, the following four had a significant indirect association: descriptive norm for children's screen time, parental screen use in front of children, parental importance for limiting children's screen time, and parental attitude toward societal pressures for children's screen time. Parents with high education had lower descriptive norm and used fewer screens in front of children compared to parents with middle or low education, and in turn, these factors were associated with less screen time among children from parents with a higher education level. Parents with high education placed greater importance on limiting children's screen time and felt less societal pressures about children's screen time compared to parents with low education, and in turn, these factors were associated with less screen time among children from parents with a higher education level. Our study recognized multiple modifiable mediators in the associations between parental education and preschool children's screen time. When aiming to diminish socioeconomic status differences in preschool children's screen time, the focus should be on parental role models, attitudes, and norm related to children's screen time.

Linking FRRF Derived Photophysiology with Carbon-based Primary Productivity: Insights from Concepts of Cellular Energy Allocation

NASA Astrophysics Data System (ADS)

Schuback, N.; Schallenberg, C.; Duckham, C.; Flecken, M.; Maldonado, M. T.; Tortell, P. D.

2016-02-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in photosystem II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides important physiological insight into phytoplankton photosynthesis, and is critical for the application of FRRF as a primary productivity measurement tool. We present data from a series of experiments during which we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific. Our results show significant variability of the derived conversion factor (Ve:C/nPSII), with highest values observed under conditions of excess excitation pressure at the level of photosystem II, caused by high light and/or low iron. Our results will be discussed in the context of metabolic plasticity, which evolved in phytoplankton to simultaneously maximize growth and provide photoprotection under fluctuating light and limiting nutrient availabilities. Because the derived conversion factor is associated with conditions of excess light, it correlates with the expression of non-photochemical quenching (NPQ) in the pigment antenna, also derived from FRRF measurements. Our results demonstrate a significant correlation between NPQ and the conversion factor Ve:C/nPSII, and the potential of this relationship to improve FRRF-based estimates of phytoplankton carbon fixation rates is discussed.

[Application of root cause analysis in healthcare].

PubMed

Hsu, Tsung-Fu

2007-12-01

The main purpose of this study was to explore various aspects of root cause analysis (RCA), including its definition, rationale concept, main objective, implementation procedures, most common analysis methodology (fault tree analysis, FTA), and advantages and methodologic limitations in regard to healthcare. Several adverse events that occurred at a certain hospital were also analyzed by the author using FTA as part of this study. RCA is a process employed to identify basic and contributing causal factors underlying performance variations associated with adverse events. The rationale concept of RCA offers a systemic approach to improving patient safety that does not assign blame or liability to individuals. The four-step process involved in conducting an RCA includes: RCA preparation, proximate cause identification, root cause identification, and recommendation generation and implementation. FTA is a logical, structured process that can help identify potential causes of system failure before actual failures occur. Some advantages and significant methodologic limitations of RCA were discussed. Finally, we emphasized that errors stem principally from faults attributable to system design, practice guidelines, work conditions, and other human factors, which induce health professionals to make negligence or mistakes with regard to healthcare. We must explore the root causes of medical errors to eliminate potential RCA system failure factors. Also, a systemic approach is needed to resolve medical errors and move beyond a current culture centered on assigning fault to individuals. In constructing a real environment of patient-centered safety healthcare, we can help encourage clients to accept state-of-the-art healthcare services.

Identifying Links Between Sexual Violence and Youth Violence Perpetration: New Opportunities for Sexual Violence Prevention

PubMed Central

DeGue, Sarah; Massetti, Greta M.; Holt, Melissa K.; Tharp, Andra Teten; Valle, Linda Anne; Matjasko, Jennifer L.; Lippy, Caroline

2018-01-01

Objective One promising opportunity for advancing sexual violence (SV) research and identifying new avenues for prevention involves examining other forms of violence that may share risk factors with SV. Youth violence (YV) is ideal for consideration given evidence of overlap in SV and YV risk factors, a large set of established YV risk factors across the social ecology, and the number of evidence-based YV prevention strategies available. The current paper identifies shared and unique risk factors for SV and YV and highlights evidence-based YV prevention strategies that impact these shared risk factors. Conclusions Researchers and program developers should consider adapting and evaluating evidence-based YV prevention strategies to prevent SV. Modifying these programs to address SV’s unique risk factors may maximize their potential effectiveness. In addition, expanding SV research at the outer levels of the social ecology is critical to developing community-level prevention strategies. The YV literature suggests several potential risk factors at these levels in need of research for SV, including school connectedness, social disorganization, and availability of alcohol and drugs. Using the YV literature as a starting point for expanding SV research leverages prior investments in YV research, may help identify new SV prevention strategies at a limited cost, and moves the field more quickly toward implementation of cost-effective, multidomain violence prevention strategies in communities. PMID:29644117

Back-streaming ion emission and beam focusing on high power linear induction accelerator

NASA Astrophysics Data System (ADS)

Zhu, Jun; Chen, Nan; Yu, Haijun; Jiang, Xiaoguo; Wang, Yuan; Dai, Wenhua; Gao, Feng; Wang, Minhong; Li, Jin; Shi, Jinshui

2011-08-01

Ions released from target surfaces by impact of a high intensity and current electron beam can be accelerated and trapped in the beam potential, and further destroy the beam focus. By solving the 2D Poisson equation, we found that the charge neutralization factor of the ions to the beam under space charge limited condition is 1/3, which is large enough to disrupt the spot size. Therefore, the ion emission at the target in a single-pulse beam/target system must be source limited. Experimental results on the time-resolved beam profile measurement have also proven that. A new focus scheme is proposed in this paper to focus the beam to a small spot size with the existence of back-streaming ions. We found that the focal spot will move upstream as the charge neutralization factor increases. By comparing the theoretical and experimental focal length of the Dragon-I accelerator (20 MeV, 2.5 kA, 60 ns flattop), we found that the average neutralization factor is about 5% in the beam/target system.

Emerging molecular therapeutic targets for cholangiocarcinoma.

PubMed

Rizvi, Sumera; Gores, Gregory J

2017-09-01

Cholangiocarcinomas (CCAs) are diverse epithelial tumors arising from the liver or large bile ducts with features of cholangiocyte differentiation. CCAs are classified anatomically into intrahepatic (iCCA), perihilar (pCCA), and distal CCA (dCCA). Each subtype has distinct risk factors, molecular pathogenesis, therapeutic options, and prognosis. CCA is an aggressive malignancy with a poor overall prognosis and median survival of less than 2years in patients with advanced disease. Potentially curative surgical treatment options are limited to the subset of patients with early-stage disease. Presently, the available systemic medical therapies for advanced or metastatic CCA have limited therapeutic efficacy. Molecular alterations define the differences in biological behavior of each CCA subtype. Recent comprehensive genetic analysis has better characterized the genomic and transcriptomic landscape of each CCA subtype. Promising candidates for targeted, personalized therapy have emerged, including potential driver fibroblast growth factor receptor (FGFR) gene fusions and somatic mutations in isocitrate dehydrogenase (IDH)1/2 in iCCA, protein kinase cAMP-activated catalytic subunit alpha (PRKACA) or beta (PRKACB) gene fusions in pCCA, and ELF3 mutations in dCCA/ampullary carcinoma. A precision genomic medicine approach is dependent on an enhanced understanding of driver mutations in each subtype and stratification of patients according to their genetic drivers. We review the current genomic landscape of CCA, the potentially actionable molecular aberrations in each CCA subtype, and the role of immunotherapy in CCA. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Development of organ-specific donor risk indices.

PubMed

Akkina, Sanjeev K; Asrani, Sumeet K; Peng, Yi; Stock, Peter; Kim, W Ray; Israni, Ajay K

2012-04-01

Because of the shortage of deceased donor organs, transplant centers accept organs from marginal deceased donors, including older donors. Organ-specific donor risk indices have been developed to predict graft survival with various combinations of donor and recipient characteristics. Here we review the kidney donor risk index (KDRI) and the liver donor risk index (LDRI) and compare and contrast their strengths, limitations, and potential uses. The KDRI has a potential role in developing new kidney allocation algorithms. The LDRI allows a greater appreciation of the importance of donor factors, particularly for hepatitis C virus-positive recipients; as the donor risk index increases, the rates of allograft and patient survival among these recipients decrease disproportionately. The use of livers with high donor risk indices is associated with increased hospital costs that are independent of recipient risk factors, and the transplantation of livers with high donor risk indices into patients with Model for End-Stage Liver Disease scores < 15 is associated with lower allograft survival; the use of the LDRI has limited this practice. Significant regional variations in donor quality, as measured by the LDRI, remain in the United States. We also review other potential indices for liver transplantation, including donor-recipient matching and the retransplant donor risk index. Although substantial progress has been made in developing donor risk indices to objectively assess donor variables that affect transplant outcomes, continued efforts are warranted to improve these indices to enhance organ allocation policies and optimize allograft survival. Copyright © 2012 American Association for the Study of Liver Diseases.

On the role of structure-dynamic relationship in determining the excess entropy of mixing and chemical ordering in binary square-well liquid alloys

NASA Astrophysics Data System (ADS)

Lalneihpuii, R.; Shrivastava, Ruchi; Mishra, Raj Kumar

2018-05-01

Using statistical mechanical model with square-well (SW) interatomic potential within the frame work of mean spherical approximation, we determine the composition dependent microscopic correlation functions, interdiffusion coefficients, surface tension and chemical ordering in Ag-Cu melts. Further Dzugutov universal scaling law of normalized diffusion is verified with SW potential in binary mixtures. We find that the excess entropy scaling law is valid for SW binary melts. The partial and total structure factors in the attractive and repulsive regions of the interacting potential are evaluated and then Fourier transformed to get partial and total radial distribution functions. A good agreement between theoretical and experimental values for total structure factor and the reduced radial distribution function are observed, which consolidates our model calculations. The well-known Bhatia-Thornton correlation functions are also computed for Ag-Cu melts. The concentration-concentration correlations in the long wavelength limit in liquid Ag-Cu alloys have been analytically derived through the long wavelength limit of partial correlation functions and apply it to demonstrate the chemical ordering and interdiffusion coefficients in binary liquid alloys. We also investigate the concentration dependent viscosity coefficients and surface tension using the computed diffusion data in these alloys. Our computed results for structure, transport and surface properties of liquid Ag-Cu alloys obtained with square-well interatomic interaction are fully consistent with their corresponding experimental values.

Development of Organ-Specific Donor Risk Indices

PubMed Central

Akkina, Sanjeev K.; Asrani, Sumeet K.; Peng, Yi; Stock, Peter; Kim, Ray; Israni, Ajay K.

2012-01-01

Due to the shortage of deceased donor organs, transplant centers accept organs from marginal deceased donors, including older donors. Organ-specific donor risk indices have been developed to predict graft survival using various combinations of donor and recipient characteristics. We will review the kidney donor risk index (KDRI) and liver donor risk index (LDRI) and compare and contrast their strengths, limitations, and potential uses. The Kidney Donor Risk Index has a potential role in developing new kidney allocation algorithms. The Liver Donor Risk Index allows for greater appreciation of the importance of donor factors, particularly for hepatitis C-positive recipients; as the donor risk index increases, rates of allograft and patient survival among these recipients decrease disproportionately. Use of livers with high donor risk index is associated with increased hospital costs independent of recipient risk factors, and transplanting livers with high donor risk index into patients with Model for End-Stage Liver Disease scores < 15 is associated with lower allograft survival; use of the Liver Donor Risk Index has limited this practice. Significant regional variation in donor quality, as measured by the Liver Donor Risk Index, remains in the United States. We also review other potential indices for liver transplant, including donor-recipient matching and the retransplant donor risk index. While substantial progress has been made in developing donor risk indices to objectively assess donor variables that affect transplant outcomes, continued efforts are warranted to improve these indices to enhance organ allocation policies and optimize allograft survival. PMID:22287036

High-Throughput Models for Exposure-Based Chemical ...

EPA Pesticide Factsheets

The United States Environmental Protection Agency (U.S. EPA) must characterize potential risks to human health and the environment associated with manufacture and use of thousands of chemicals. High-throughput screening (HTS) for biological activity allows the ToxCast research program to prioritize chemical inventories for potential hazard. Similar capabilities for estimating exposure potential would support rapid risk-based prioritization for chemicals with limited information; here, we propose a framework for high-throughput exposure assessment. To demonstrate application, an analysis was conducted that predicts human exposure potential for chemicals and estimates uncertainty in these predictions by comparison to biomonitoring data. We evaluated 1936 chemicals using far-field mass balance human exposure models (USEtox and RAIDAR) and an indicator for indoor and/or consumer use. These predictions were compared to exposures inferred by Bayesian analysis from urine concentrations for 82 chemicals reported in the National Health and Nutrition Examination Survey (NHANES). Joint regression on all factors provided a calibrated consensus prediction, the variance of which serves as an empirical determination of uncertainty for prioritization on absolute exposure potential. Information on use was found to be most predictive; generally, chemicals above the limit of detection in NHANES had consumer/indoor use. Coupled with hazard HTS, exposure HTS can place risk earlie

The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act.

PubMed

Johnson, Matthew W; Griffiths, Roland R; Hendricks, Peter S; Henningfield, Jack E

2018-06-05

This review assesses the abuse potential of medically-administered psilocybin, following the structure of the 8 factors of the US Controlled Substances Act (CSA). Research suggests the potential safety and efficacy of psilocybin in treating cancer-related psychiatric distress and substance use disorders, setting the occasion for this review. A more extensive assessment of abuse potential according to an 8-factor analysis would eventually be required to guide appropriate schedule placement. Psilocybin, like other 5-HT2A agonist classic psychedelics, has limited reinforcing effects, supporting marginal, transient non-human self-administration. Nonetheless, mushrooms with variable psilocybin content are used illicitly, with a few lifetime use occasions being normative among users. Potential harms include dangerous behavior in unprepared, unsupervised users, and exacerbation of mental illness in those with or predisposed to psychotic disorders. However, scope of use and associated harms are low compared to prototypical abused drugs, and the medical model addresses these concerns with dose control, patient screening, preparation and follow-up, and session supervision in a medical facility. (1) psilocybin has an abuse potential appropriate for CSA scheduling if approved as medicine; (2) psilocybin can provide therapeutic benefits that may support the development of an approvable New Drug Application (NDA) but further studies are required which this review describes; (3) adverse effects of medical psilocybin are manageable when administered according to risk management approaches; and (4) although further study is required, this review suggests that placement in Schedule IV may be appropriate if a psilocybin-containing medicine is approved. Copyright © 2018. Published by Elsevier Ltd.

Are workplace health promotion programs effective at improving presenteeism in workers? a systematic review and best evidence synthesis of the literature

PubMed Central

2011-01-01

Background Presenteeism is highly prevalent and costly to employers. It is defined as being present at work, but limited in some aspect of job performance by a health problem. Workplace health promotion (WHP) is a common strategy used to enhance on-the-job productivity. The primary objective is to determine if WHP programs are effective in improving presenteeism. The secondary objectives are to identify characteristics of successful programs and potential risk factors for presenteeism. Methods The Cochrane Library, Medline, and other electronic databases were searched from 1990 to 2010. Reference lists were examined, key journals were hand-searched and experts were contacted. Included studies were original research that contained data on at least 20 participants (≥ 18 years of age), and examined the impacts of WHP programs implemented at the workplace. The Effective Public Health Practice Project Tool for Quantitative Studies was used to rate studies. 'Strong' and 'moderate' studies were abstracted into evidence tables, and a best evidence synthesis was performed. Interventions were deemed successful if they improved the outcome of interest. Their program components were identified, as were possible risk factors contributing to presenteeism. Results After 2,032 titles and abstracts were screened, 47 articles were reviewed, and 14 were accepted (4 strong and 10 moderate studies). These studies contained preliminary evidence for a positive effect of some WHP programs. Successful programs offered organizational leadership, health risk screening, individually tailored programs, and a supportive workplace culture. Potential risk factors contributing to presenteeism included being overweight, a poor diet, a lack of exercise, high stress, and poor relations with co-workers and management. Limitations: This review is limited to English publications. A large number of reviewed studies (70%) were inadmissible due to issues of bias, thus limiting the amount of primary evidence. The uncertainties surrounding presenteeism measurement is of significant concern as a source of bias. Conclusions The presenteeism literature is young and heterogeneous. There is preliminary evidence that some WHP programs can positively affect presenteeism and that certain risk factors are of importance. Future research would benefit from standard presenteeism metrics and studies conducted across a broad range of workplace settings. PMID:21615940

A case study evaluation of a Critical Care Information System adoption using the socio-technical and fit approach.

PubMed

Yusof, Maryati Mohd

2015-07-01

Clinical information systems have long been used in intensive care units but reports on their adoption and benefits are limited. This study evaluated a Critical Care Information System implementation. A case study summative evaluation was conducted, employing observation, interview, and document analysis in operating theatres and 16-bed adult intensive care units in a 400-bed Malaysian tertiary referral centre from the perspectives of users (nurses and physicians), management, and information technology staff. System implementation, factors influencing adoption, fit between these factors, and the impact of the Critical Care Information System were evaluated after eight months of operation. Positive influences on system adoption were associated with technical factors, including system ease of use, usefulness, and information relevancy; human factors, particularly user attitude; and organisational factors, namely clinical process-technology alignment and champions. Organisational factors such as planning, project management, training, technology support, turnover rate, clinical workload, and communication were barriers to system implementation and use. Recommendations to improve the current system problems were discussed. Most nursing staff positively perceived the system's reduction of documentation and data access time, giving them more time with patients. System acceptance varied among doctors. System use also had positive impacts on timesaving, data quality, and clinical workflow. Critical Care Information Systems is crucial and has great potentials in enhancing and delivering critical care. However, the case study findings showed that the system faced complex challenges and was underutilised despite its potential. The role of socio-technical factors and their fit in realizing the potential of Critical Care Information Systems requires continuous, in-depth evaluation and stakeholder understanding and acknowledgement. The comprehensive and specific evaluation measures of the Human-Organisation-Technology Fit framework can flexibly evaluate Critical Care Information Systems. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Towards setting credible speed limits: Identifying factors that affect driver compliance on urban roads.

PubMed

Gargoum, Suliman A; El-Basyouny, Karim; Kim, Amy

2016-10-01

Road geometry, vehicle characteristics, and weather conditions are all factors that impact a driver's perception of a safe or credible speed and, consequently, the driver's decision on whether or not to comply with the posted speed limit. In fact, the role a road's environment plays in a driver's perception of a credible speed limit is a topic that has attracted the interest of many researchers in recent years. Despite that, not many studies have considered using empirical data to investigate what features of the road environment influence a driver's compliance choice. This paper aims to address this matter by exploring the relationships between features of the road surroundings (geometric, temporal factors, and weather conditions) and driver compliance with speed limits. The paper uses data from almost 600 different urban roads in the city of Edmonton, at which over 35 million vehicle spot speeds were collected. Compliance was represented using a categorical ordered response variable, and mixed-effects-logistic-regression models were fitted. Two different models were built, one for arterials and another for collector roads. In general, the findings show that the more restricted drivers become, particularly on arterials, the more likely drivers are to comply with speed limits; potential restrictions include on-street parking and the absence of lateral shoulders. Furthermore, higher traffic activity during peak hours, and presumably on shoulder weekdays, both increase the likelihood of compliance on arterials. Similarly, posted speed limits and traffic volume are both positively correlated with compliance on both arterial and collector roads. The findings of this research provide evidence of the existence of an empirical relationship between road features and compliance, highlighting the importance of setting credible speed limits on roads and the possibility of achieving higher compliance rates through modifications to the road environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Altitudinal vs Latitudinal Climactic Drivers: A Comparison of a Relict Picea and Abies Forest in the Southern Appalachians versus the Hemi-Boreal Transition Zone off Southern Canada

NASA Astrophysics Data System (ADS)

Evans, A.; Lafon, C. W.

2015-12-01

Identification of biotic and abiotic determinants of tree species range limits is critical for understanding the effects of climate change on species distributions. Upward shifts of species distributions in montane areas have been widely reported but there have been few reports of latitudinal range retractions. Previous studies have indicated that southern latitudinal limits of a species range are dictated by biotic factors such as competition while others have suggested that abiotic factors, such as temperature, dictate these limits. We investigated the potential climatic gradients at the southern latitudinal limit of the Spruce (Picea) and Fir (Abies) species that dominate the Canadian boreal forest community as well as relict boreal forests containing similar species found in the high elevation areas of the Southern Appalachians. Existing research has suggested that relict ecosystems are more sensitive to climate change and can be indicative of future changes at latitudinal range limits. Expanding on this literature, we hypothesized that we would see similar gradients in climatic variables at the southern latitudinal limit of the Canadian boreal forest and those in the relict boreal forests southern Appalachians acting as controlling factors of these species distributions. We used forty years of climate data from weather stations along the southern edge of the boreal forest in the Canadian Shield provinces, species distribution data from the Canadian National Forest Inventory, (CNFI) geospatial data from the National Park Service (NPS), and historical weather data from the National Oceanic and Atmospheric Administration (NOAA) to perform our analysis. Our results indicate different climate variables act as controls of warm edge range limits of the Canadian boreal forest than those of the relict boreal forest of the southern Appalachians. However, we believe range retractions of the relict forest may be indicative of a more gradual response of similar species across a latitudinal gradient.

Stream primary producers relate positively to watershed natural gas measures in north-central Arkansas streams.

PubMed

Austin, Bradley J; Hardgrave, Natalia; Inlander, Ethan; Gallipeau, Cory; Entrekin, Sally; Evans-White, Michelle A

2015-10-01

Construction of unconventional natural gas (UNG) infrastructure (e.g., well pads, pipelines) is an increasingly common anthropogenic stressor that increases potential sediment erosion. Increased sediment inputs into nearby streams may decrease autotrophic processes through burial and scour, or sediment bound nutrients could have a positive effect through alleviating potential nutrient limitations. Ten streams with varying catchment UNG well densities (0-3.6 wells/km(2)) were sampled during winter and spring of 2010 and 2011 to examine relationships between landscape scale disturbances associated with UNG activity and stream periphyton [chlorophyll a (Chl a)] and gross primary production (GPP). Local scale variables including light availability and water column physicochemical variables were measured for each study site. Correlation analyses examined the relationships of autotrophic processes and local scale variables with the landscape scale variables percent pasture land use and UNG metrics (well density and well pad inverse flow path length). Both GPP and Chl a were primarily positively associated with the UNG activity metrics during most sample periods; however, neither landscape variables nor response variables correlated well with local scale factors. These positive correlations do not confirm causation, but they do suggest that it is possible that UNG development can alleviate one or more limiting factors on autotrophic production within these streams. A secondary manipulative study was used to examine the link between nutrient limitation and algal growth across a gradient of streams impacted by natural gas activity. Nitrogen limitation was common among minimally impacted stream reaches and was alleviated in streams with high UNG activity. These data provide evidence that UNG may stimulate the primary production of Fayetteville shale streams via alleviation of N-limitation. Restricting UNG activities from the riparian zone along with better enforcement of best management practices should help reduce these possible impacts of UNG activities on stream autotrophic processes. Copyright © 2015 Elsevier B.V. All rights reserved.

The influence of vertical disparity gradient and cue conflict on EEG omega complexity in Panum's limiting case.

PubMed

Li, Huayun; Jia, Huibin; Yu, Dongchuan

2018-03-01

Using behavioral measures and ERP technique, researchers discovered at least two factors could influence the final perception of depth in Panum's limiting case, which are the vertical disparity gradient and the degree of cue conflict between two- and three-dimensional shapes. Although certain event-related potential components have been proved to be sensitive to the different levels of these two factors, some methodological limitations existed in this technique. In this study, we proposed that the omega complexity of EEG signal may serve as an important supplement of the traditional event-related potential technique. We found that the trials with lower vertical gradient disparity have lower omega complexity (i.e., higher global functional connectivity) of the occipital region, especially that of the right-occipital hemisphere. Moreover, for occipital omega complexity, the trials with low-cue conflict have significantly larger omega complexity than those with medium- and high-cue conflict. It is also found that the electrodes located in the middle line of the occipital region (i.e., POz and Oz) are more crucial to the impact of different levels of cue conflict on omega complexity than the other electrodes located in the left- and right-occipital hemispheres. These evidences demonstrated that the EEG omega complexity could reflect distinct neural activities evoked by Panum's limiting case configurations, with different levels of vertical disparity gradient and cue conflict. Besides, the influence of vertical disparity gradient and cue conflict on omega complexity may be regional dependent. NEW & NOTEWORTHY The EEG omega complexity could reflect distinct neural activities evoked by Panum's limiting case configurations with different levels of vertical disparity gradient and cue conflict. The influence of vertical disparity gradient and cue conflict on omega complexity is regional dependent. The omega complexity of EEG signal can serve as an important supplement of the traditional ERP technique.

Sexually Transmitted Diseases and Infertility

PubMed Central

TSEVAT, Danielle G.; WIESENFELD, Harold C.; Parks, Caitlin; PEIPERT, Jeffrey F.

2016-01-01

Female infertility, including tubal factor infertility, is a major public health concern worldwide. Most cases of tubal factor infertility are attributable to untreated sexually transmitted diseases that ascend along the reproductive tract and are capable of causing tubal inflammation, damage, and scarring. Evidence has consistently demonstrated the effects of Chlamydia trachomatis and Neisseria gonorrhoeae as pathogenic bacteria involved in reproductive tract morbidities including tubal factor infertility and pelvic inflammatory disease. There is limited evidence in the medical literature that other sexually transmitted organisms, including Mycoplasma genitalium, Trichomonas vaginalis, and other microorganisms within the vaginal microbiome may be important factors involved in the pathology of infertility. Further investigation into the vaginal microbiome and other potential pathogens is necessary in order to identify preventable causes of tubal factor infertility. Improved clinical screening and prevention of ascending infection may provide a solution to the persistent burden of infertility. PMID:28007229

Bioavailability Challenges Associated with Development of Anti-Cancer Phenolics

PubMed Central

Gao, Song; Hu, Ming

2010-01-01

Phenolics including many polyphenols and flavonoids have the potentials to become chemoprevention and chemotherapy agents. However, poor bioavailability limits their biological effects in vivo. This paper reviews the factors that affect phenolics absorption and their bioavailabilities from the points of view of their physicochemical properties and disposition in the gastrointestinal tract. The up-to-date research data suggested that solubility and metabolism are the primary reasons that limit phenolic aglycones’ bioavailability although stability and poor permeation may also contribute to the poor bioavailabilities of the glycosides. Future investigations should further optimize phenolics’ bioavailabilities and realize their chemopreventive and chemotherapeutic effects in vivo. PMID:20370701

Using the Tax System to Promote Physical Activity: Critical Analysis of Canadian Initiatives

PubMed Central

Larre, Tamara; Sauder, JoAnne

2011-01-01

In Canada, tax incentives have been recently introduced to promote physical activity and reduce rates of obesity. The most prominent of these is the federal government's Children's Fitness Tax Credit, which came into effect in 2007. We critically assess the potential benefits and limitations of using tax measures to promote physical activity. Careful design could make these measures more effective, but any tax-based measures have inherent limitations, and the costs of such programs are substantial. Therefore, it is important to consider whether public funds are better spent on other strategies that could instead provide direct public funding to address environmental and systemic factors. PMID:21680912

Using the tax system to promote physical activity: critical analysis of Canadian initiatives.

PubMed

von Tigerstrom, Barbara; Larre, Tamara; Sauder, Joanne

2011-08-01

In Canada, tax incentives have been recently introduced to promote physical activity and reduce rates of obesity. The most prominent of these is the federal government's Children's Fitness Tax Credit, which came into effect in 2007. We critically assess the potential benefits and limitations of using tax measures to promote physical activity. Careful design could make these measures more effective, but any tax-based measures have inherent limitations, and the costs of such programs are substantial. Therefore, it is important to consider whether public funds are better spent on other strategies that could instead provide direct public funding to address environmental and systemic factors.

Potential of the Thermal Infrared Wavelength Region to predict semi-arid Soil Surface Properties for Remote Sensing Monitoring

NASA Astrophysics Data System (ADS)

Eisele, Andreas; Chabrillat, Sabine; Lau, Ian; Hecker, Christoph; Hewson, Robert; Carter, Dan; Wheaton, Buddy; Ong, Cindy; Cudahy, Thomas John; Kaufmann, Hermann

2014-05-01

Digital soil mapping with the means of passive remote sensing basically relies on the soils' spectral characteristics and an appropriate atmospheric window, where electromagnetic radiation transmits without significant attenuation. Traditionally the atmospheric window in the solar-reflective wavelength region (visible, VIS: 0.4 - 0.7 μm; near infrared, NIR: 0.7 - 1.1 μm; shortwave infrared, SWIR: 1.1 - 2.5 μm) has been used to quantify soil surface properties. However, spectral characteristics of semi-arid soils, typically have a coarse quartz rich texture and iron coatings that can limit the prediction of soil surface properties. In this study we investigated the potential of the atmospheric window in the thermal wavelength region (long wave infrared, LWIR: 8 - 14 μm) to predict soil surface properties such as the grain size distribution (texture) and the organic carbon content (SOC) for coarse-textured soils from the Australian wheat belt region. This region suffers soil loss due to wind erosion processes and large scale monitoring techniques, such as remote sensing, is urgently required to observe the dynamic changes of such soil properties. The coarse textured sandy soils of the investigated area require methods, which can measure the special spectral response of the quartz dominated mineralogy with iron oxide enriched grain coatings. By comparison, the spectroscopy using the solar-reflective region has limitations to discriminate such arid soil mineralogy and associated coatings. Such monitoring is important for observing potential desertification trends associated with coarsening of topsoil texture and reduction in SOC. In this laboratory study we identified the relevant LWIR wavelengths to predict these soil surface properties. The results showed the ability of multivariate analyses methods (PLSR) to predict these soil properties from the soil's spectral signature, where the texture parameters (clay and sand content) could be predicted well in the models using the LWIR-window (sand content: R2 = 0.84 and RMSECV = 1.09 %, and for clay content: R2 = 0.77 and RMSECV = 1.0 %, both with 3 factor models). In comparison, the quantification from the solar-reflective window showed its limitations in its relative complex PLSR models and a lower prediction accuracy (sand content: R2 = 0.69 and RMSECV = 1.5 % with 7 factors, and for clay content: R2 = 0.64 and RMSECV = 1.26 % with 9 factors). The prediction of the SOC content, on the other hand, showed minor disparity between the two atmospheric windows (LWIR: R2 = 0.73 and RMSECV = 0.1 % with 6 factors, VNIR-SWIR: R2 = 0.69 and RMSECV = 0.11 %, with 9 factors). The prospect of the LWIR for determining soil texture was demonstrated to be even more impressive when reduced to the spectral band specifications of airborne (TASI-600) and spaceborne (ASTER) sensors. The results demonstrate the high potential of the LWIR to detect and quantify soil surface properties in the future for a monitoring via LWIR hyperspectral remote sensing.

Radio-frequency Electrometry Using Rydberg Atoms in Vapor Cells: Towards the Shot Noise Limit

NASA Astrophysics Data System (ADS)

Kumar, Santosh; Fan, Haoquan; Jahangiri, Akbar; Kuebler, Harald; Shaffer, James P.; 5. Physikalisches Institut, Universitat Stuttgart, Germany Collaboration

2016-05-01

Rydberg atoms are a promising candidate for radio frequency (RF) electric field sensing. Our method uses electromagnetically induced transparency with Rydberg atoms in vapor cells to read out the effect that the RF electric field has on the Rydberg atoms. The method has the potential for high sensitivity (pV cm-1 Hz- 1 / 2) and can be self-calibrated. Some of the main factors limiting the sensitivity of RF electric field sensing from reaching the shot noise limit are the residual Doppler effect and the sensitivity of the optical read-out using the probe laser. We present progress on overcoming the residual Doppler effect by using a new multi-photon scheme and reaching the shot noise detection limit using frequency modulated spectroscopy. Our experiments also show promise for studying quantum optical effects such as superradiance in vapor cells using Rydberg atoms. This work is supported by DARPA, ARO, and NRO.

Pseudo hard-sphere potential for use in continuous molecular-dynamics simulation of spherical and chain molecules.

PubMed

Jover, J; Haslam, A J; Galindo, A; Jackson, G; Müller, E A

2012-10-14

We present a continuous pseudo-hard-sphere potential based on a cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). Using this potential one can mimic the volumetric, structural, and dynamic properties of the discontinuous hard-sphere potential over the whole fluid range. The continuous pseudo potential has the advantage that it may be incorporated directly into off-the-shelf molecular-dynamics code, allowing the user to capitalise on existing hardware and software advances. Simulation results for the compressibility factor of the fluid and solid phases of our pseudo hard spheres are presented and compared both to the Carnahan-Starling equation of state of the fluid and published data, the differences being indistinguishable within simulation uncertainty. The specific form of the potential is employed to simulate flexible chains formed from these pseudo hard spheres at contact (pearl-necklace model) for m(c) = 4, 5, 7, 8, 16, 20, 100, 201, and 500 monomer segments. The compressibility factor of the chains per unit of monomer, m(c), approaches a limiting value at reasonably small values, m(c) < 50, as predicted by Wertheim's first order thermodynamic perturbation theory. Simulation results are also presented for highly asymmetric mixtures of pseudo hard spheres, with diameter ratios of 3:1, 5:1, 20:1 over the whole composition range.

Parenting practices and adolescent sexual behavior: A longitudinal study

PubMed Central

Bersamin, Melina; Todd, Michael; Fisher, Deborah A.; Hill, Douglas L.; Grube, Joel W.; Walker, Samantha

2009-01-01

The effects of parental attitudes, practices, and television mediation on adolescent sexual behaviors were investigated in a study of adolescent sexuality and media (N=887). Confirmatory factor analyses supported an eight-factor parenting model with television mediation factors as constructs distinct from general parenting practices. Logistic regressions indicated that adolescents reporting greater parental disapproval and limits on viewing at Wave 1 were less likely to initiate oral sex between Waves 1 and 2. Adolescents who reported more sexual communication with parents were more likely to initiate oral sex. Results for vaginal intercourse were similar to those for oral sex. Co-viewing was a significant negative predictor of initiation of sexual behavior. Parental attitudes and television mediation can delay potentially risky adolescent sexual behaviors. PMID:19750131

Development of construction materials like concrete from lunar soils without water

NASA Technical Reports Server (NTRS)

Desai, Chandra S.; Saadatmanesh, H.; Frantziskonis, G.

1989-01-01

The development of construction materials such as concrete from lunar soils without the use of water requires a different methodology than that used for conventional terrestrial concrete. A unique approach is attempted that utilizes factors such as initial vacuum and then cyclic loading to enhance the mechanical properties of dry materials similar to those available on the moon. The application of such factors is expected to allow reorientation, and coming together, of particles of the materials toward the maximum theoretical density. If such a density can provide deformation and strength properties for even a limited type of construction, the approach can have significant application potential, although other factors such as heat and chemicals may be needed for specific construction objectives.

The use and misuse of journal metrics and other citation indicators.

PubMed

Pendlebury, David A

2009-01-01

This article reviews the nature and use of the journal impact factor and other common bibliometric measures for assessing research in the sciences and social sciences based on data compiled by Thomson Reuters. Journal impact factors are frequently misused to assess the influence of individual papers and authors, but such uses were never intended. Thomson Reuters also employs other measures of journal influence, which are contrasted with the impact factor. Finally, the author comments on the proper use of citation data in general, often as a supplement to peer review. This review may help government policymakers, university administrators, and individual researchers become better acquainted with the potential benefits and limitations of bibliometrics in the evaluation of research.

Potential and range of application of elastic backscatter lidar systems using polarization selection to minimize detected skylight noise

NASA Astrophysics Data System (ADS)

Ahmed, S. A.; Hassebo, Y. Y.; Gross, B.; Oo, M.; Moshary, F.

2006-09-01

We examine the potential, range of application, and limiting factors of a polarization selection technique, recently devised by us, which takes advantage of naturally occurring polarization properties of scattered sky light to minimize the detected sky background signal and which can be used in conjunction with linearly polarized elastic backscatter lidars to maximize lidar receiver SNR. In this approach, a polarization selective lidar receiver is aligned to minimize detected skylight, while the polarization of the transmitted lidar signal is rotated to maintain maximum lidar backscatter signal throughput to the receiver detector, consequently maximizing detected signal to noise ratio. Results presented include lidar elastic backscatter measurements, at 532 nm which show as much as a factor of √10 improvement in signal-to-noise ratio over conventional un-polarized schemes. For vertically pointing lidars, the largest improvements are limited to symmetric early morning and late afternoon hours. For non-vertical scanning lidars, significant improvements are achievable over much more extended time periods, depending on the specific angle between the lidar and solar axes. A theoretical model that simulates the background skylight within the single scattering approximation showed good agreement with measured SNR improvement factors. Diurnally asymmetric improvement factors, sometimes observed, are explained by measured increases in PWV and subsequent modification of aerosol optical depth by dehydration from morning to afternoon. Finally, since the polarization axis follows the solar azimuth angle even for high aerosol loading, as demonstrated using radiative transfer simulations, it is possible to conceive automation of the technique. In addition, it is shown that while multiple scattering reduces the SNR improvement, the orientation of the minimum noise state remains the same.

Social capital: theory, evidence, and implications for oral health.

PubMed

Rouxel, Patrick L; Heilmann, Anja; Aida, Jun; Tsakos, Georgios; Watt, Richard G

2015-04-01

In the last two decades, there has been increasing application of the concept of social capital in various fields of public health, including oral health. However, social capital is a contested concept with debates on its definition, measurement, and application. This study provides an overview of the concept of social capital, highlights the various pathways linking social capital to health, and discusses the potential implication of this concept for health policy. An extensive and diverse international literature has examined the relationship between social capital and a range of general health outcomes across the life course. A more limited but expanding literature has also demonstrated the potential influence of social capital on oral health. Much of the evidence in relation to oral health is limited by methodological shortcomings mainly related to the measurement of social capital, cross-sectional study designs, and inadequate controls for confounding factors. Further research using stronger methodological designs should explore the role of social capital in oral health and assess its potential application in the development of oral health improvement interventions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Current investigations into the genotoxicity of zinc oxide and silica nanoparticles in mammalian models in vitro and in vivo: carcinogenic/genotoxic potential, relevant mechanisms and biomarkers, artifacts, and limitations

PubMed Central

Kwon, Jee Young; Koedrith, Preeyaporn; Seo, Young Rok

2014-01-01

Engineered nanoparticles (NPs) are widely used in many sectors, such as food, medicine, military, and sport, but their unique characteristics may cause deleterious health effects. Close attention is being paid to metal NP genotoxicity; however, NP genotoxic/carcinogenic effects and the underlying mechanisms remain to be elucidated. In this review, we address some metal and metal oxide NPs of interest and current genotoxicity tests in vitro and in vivo. Metal NPs can cause DNA damage such as chromosomal aberrations, DNA strand breaks, oxidative DNA damage, and mutations. We also discuss several parameters that may affect genotoxic response, including physicochemical properties, widely used assays/end point tests, and experimental conditions. Although potential biomarkers of nanogenotoxicity or carcinogenicity are suggested, inconsistent findings in the literature render results inconclusive due to a variety of factors. Advantages and limitations related to different methods for investigating genotoxicity are described, and future directions and recommendations for better understanding genotoxic potential are addressed. PMID:25565845

A practical guide to self-sustaining point-of-care ultrasound education programs in resource-limited settings.

PubMed

Henwood, Patricia C; Mackenzie, David C; Rempell, Joshua S; Murray, Alice F; Leo, Megan M; Dean, Anthony J; Liteplo, Andrew S; Noble, Vicki E

2014-09-01

The value of point-of-care ultrasound education in resource-limited settings is increasingly recognized, though little guidance exists on how to best construct a sustainable training program. Herein we offer a practical overview of core factors to consider when developing and implementing a point-of-care ultrasound education program in a resource-limited setting. Considerations include analysis of needs assessment findings, development of locally relevant curriculum, access to ultrasound machines and related technological and financial resources, quality assurance and follow-up plans, strategic partnerships, and outcomes measures. Well-planned education programs in these settings increase the potential for long-term influence on clinician skills and patient care. Copyright © 2014 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

NEUROTROPHIC FACTORS IN COMBINATORIAL APPROACHES FOR SPINAL CORD REGENERATION

PubMed Central

McCall, Julianne; Weidner, Norbert; Blesch, Armin

2012-01-01

Axonal regeneration is inhibited by a plethora of different mechanisms in the adult central nervous system (CNS). While neurotrophic factors have been shown to stimulate axonal growth in numerous animal models of nervous system injury, a lack of suitable growth substrates, an insufficient activation of neuron-intrinsic regenerative programs and extracellular inhibitors of regeneration limit the efficacy of neurotrophic factor delivery for anatomical and functional recovery after spinal cord injury. Thus, growth-stimulating factors will likely have to be combined with other treatment approaches to tap into the full potential of growth factor therapy for axonal regeneration. In addition, the temporal and spatial distribution of growth factors have to be tightly controlled to achieve biologically active concentrations, to allow for the chemotropic guidance of axons and to prevent adverse effects related to the widespread distribution of neurotrophic factors. Here, we will review the rationale for combinatorial treatments in axonal regeneration and summarize some recent progress in promoting axonal regeneration in the injured CNS using such approaches. PMID:22526621

Examination of the Beck Depression Inventory-II Factor Structure Among Bariatric Surgery Candidates.

PubMed

Hayes, Sharon; Stoeckel, Nina; Napolitano, Melissa A; Collins, Charlotte; Wood, G Craig; Seiler, Jamie; Grunwald, Heidi E; Foster, Gary D; Still, Christopher D

2015-07-01

The Beck Depression Inventory-II (BDI-II) is frequently used to evaluate bariatric patients in clinical and research settings; yet, there are limited data regarding the factor structure of the BDI-II with a bariatric surgery population. Exploratory factor analysis (EFA) using principal axis factoring with oblimin rotation was employed with data from 1228 consecutive presurgical bariatric candidates. Independent t tests were used to examine potential differences between sexes. Confirmatory factor analysis (CFA) was conducted with the next 383 consecutive presurgical patients to evaluate the proposed model based on EFA results. EFA revealed three factors: negative perceptions, diminished vigor, and cognitive dysregulation, each with adequate internal consistency. Six BDI-II items did not load significantly on any of the three factors. CFA results largely supported the proposed model. Results suggest that dimensions of depression for presurgical bariatric candidates vary from other populations and raise important caveats regarding the utility of the BDI-II in bariatric research.

Stability of DIII-D high-performance, negative central shear discharges

NASA Astrophysics Data System (ADS)

Hanson, J. M.; Berkery, J. W.; Bialek, J.; Clement, M.; Ferron, J. R.; Garofalo, A. M.; Holcomb, C. T.; La Haye, R. J.; Lanctot, M. J.; Luce, T. C.; Navratil, G. A.; Olofsson, K. E. J.; Strait, E. J.; Turco, F.; Turnbull, A. D.

2017-05-01

Tokamak plasma experiments on the DIII-D device (Luxon et al 2005 Fusion Sci. Tech. 48 807) demonstrate high-performance, negative central shear (NCS) equilibria with enhanced stability when the minimum safety factor {{q}\\text{min}} exceeds 2, qualitatively confirming theoretical predictions of favorable stability in the NCS regime. The discharges exhibit good confinement with an L-mode enhancement factor H 89  =  2.5, and are ultimately limited by the ideal-wall external kink stability boundary as predicted by ideal MHD theory, as long as tearing mode (TM) locking events, resistive wall modes (RWMs), and internal kink modes are properly avoided or controlled. Although the discharges exhibit rotating TMs, locking events are avoided as long as a threshold minimum safety factor value {{q}\\text{min}}>2 is maintained. Fast timescale magnetic feedback control ameliorates RWM activity, expanding the stable operating space and allowing access to {β\\text{N}} values approaching the ideal-wall limit. Quickly growing and rotating instabilities consistent with internal kink mode dynamics are encountered when the ideal-wall limit is reached. The RWM events largely occur between the no- and ideal-wall pressure limits predicted by ideal MHD. However, evaluating kinetic contributions to the RWM dispersion relation results in a prediction of passive stability in this regime due to high plasma rotation. In addition, the ideal MHD stability analysis predicts that the ideal-wall limit can be further increased to {β\\text{N}}>4 by broadening the current profile. This path toward improved stability has the potential advantage of being compatible with the bootstrap-dominated equilibria envisioned for advanced tokamak (AT) fusion reactors.

The Dangers of Cassava (Tapioca) Consumption

PubMed Central

Hall, Michael J

1987-01-01

Cassava (Tapioca) is a worldwide staple food consumed by over 800 million people. It contains cyanide which may lead to acute toxicity or chronically may be an aetiological factor in tropical nutritional amblyopia, tropical neuropathy, endemic goitre, cretinism and tropical diabetes. It may also have carcinogenic potential. However, despite nutritional limitations it has many advantages as a crop to the subsistence farmer and would be difficult to replace. PMID:28906749

Physics of Artificial Gravity

NASA Technical Reports Server (NTRS)

Bukley, Angie; Paloski, William; Clement, Gilles

2006-01-01

This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

High Mobility Conjugated Polymers

DTIC Science & Technology

2007-10-20

will act as a trap for opposite charge carriers; the electron affinities were 4.0 eV (BBL) and 2.7 eV (PTHQx) and ionization potentials were 6.0 eV...transistors (OFETs), photovoltaic cells, and photodetectors, is limited primarily by the low charge carrier mobilities of current materials. To address this...showing a maximum mobility with hexyl. Fundamental insights into the structural factors that govern high mobility charge transport and recombination in

Current research on pharmacologic and regenerative therapies for osteoarthritis

PubMed Central

Zhang, Wei; Ouyang, Hongwei; Dass, Crispin R; Xu, Jiake

2016-01-01

Osteoarthritis (OA) is a degenerative joint disorder commonly encountered in clinical practice, and is the leading cause of disability in elderly people. Due to the poor self-healing capacity of articular cartilage and lack of specific diagnostic biomarkers, OA is a challenging disease with limited treatment options. Traditional pharmacologic therapies such as acetaminophen, non-steroidal anti-inflammatory drugs, and opioids are effective in relieving pain but are incapable of reversing cartilage damage and are frequently associated with adverse events. Current research focuses on the development of new OA drugs (such as sprifermin/recombinant human fibroblast growth factor-18, tanezumab/monoclonal antibody against β-nerve growth factor), which aims for more effectiveness and less incidence of adverse effects than the traditional ones. Furthermore, regenerative therapies (such as autologous chondrocyte implantation (ACI), new generation of matrix-induced ACI, cell-free scaffolds, induced pluripotent stem cells (iPS cells or iPSCs), and endogenous cell homing) are also emerging as promising alternatives as they have potential to enhance cartilage repair, and ultimately restore healthy tissue. However, despite currently available therapies and research advances, there remain unmet medical needs in the treatment of OA. This review highlights current research progress on pharmacologic and regenerative therapies for OA including key advances and potential limitations. PMID:26962464

Couldn't or wouldn't? The influence of privacy concerns and self-efficacy in privacy management on privacy protection.

PubMed

Chen, Hsuan-Ting; Chen, Wenghong

2015-01-01

Sampling 515 college students, this study investigates how privacy protection, including profile visibility, self-disclosure, and friending, are influenced by privacy concerns and efficacy regarding one's own ability to manage privacy settings, a factor that researchers have yet to give a great deal of attention to in the context of social networking sites (SNSs). The results of this study indicate an inconsistency in adopting strategies to protect privacy, a disconnect from limiting profile visibility and friending to self-disclosure. More specifically, privacy concerns lead SNS users to limit their profile visibility and discourage them from expanding their network. However, they do not constrain self-disclosure. Similarly, while self-efficacy in privacy management encourages SNS users to limit their profile visibility, it facilitates self-disclosure. This suggests that if users are limiting their profile visibility and constraining their friending behaviors, it does not necessarily mean they will reduce self-disclosure on SNSs because these behaviors are predicted by different factors. In addition, the study finds an interaction effect between privacy concerns and self-efficacy in privacy management on friending. It points to the potential problem of increased risk-taking behaviors resulting from high self-efficacy in privacy management and low privacy concerns.

Advances in Understanding of Penile Carcinogenesis: The Search for Actionable Targets

PubMed Central

Chaing, Sharon; Azizi, Mounsif; Kidd, Laura C.; Kim, Patricia; Spiess, Philippe E.

2017-01-01

Penile cancer (PeCa) is a rare malignancy with potentially devastating effects. Squamous cell carcinoma is the most common variant with distinct precancerous lesions before development into invasive disease. Involvement of the inguinal lymph nodes is the most important prognostic factor in PeCa, and once disease is present outside the groin, prognosis is poor. Metastatic PeCa is challenging to treat and often requires multidisciplinary approaches in management. Due to its rarity, molecular understanding of the disease continues to be limited with most studies based on small, single center series. Thus far, it appears PeCa has diverse mechanisms of carcinogenesis affecting similar molecular pathways. In this review, we evaluate the current landscape of the molecular carcinogenesis of PeCa and explore ongoing research on potential actionable targets of therapy. The emergence of anti-epidermal growth factor receptor (EGFR) and other immunotherapeutic strategies may improve outcomes for PeCa patients. PMID:28813024

Understanding the Key to Targeting the IGF Axis in Cancer: A Biomarker Assessment

PubMed Central

Lodhia, Kunal Amratlal; Tienchaiananda, Piyawan; Haluska, Paul

2015-01-01

Type 1 insulin like growth factor receptor (IGF-1R) targeted therapies showed compelling pre-clinical evidence; however, to date, this has failed to translate into patient benefit in Phase 2/3 trials in unselected patients. This was further complicated by the toxicity, including hyperglycemia, which largely results from the overlap between IGF and insulin signaling systems and associated feedback mechanisms. This has halted the clinical development of inhibitors targeting IGF signaling, which has limited the availability of biopsy samples for correlative studies to understand biomarkers of response. Indeed, a major factor contributing to lack of clinical benefit of IGF targeting agents has been difficulty in identifying patients with tumors driven by IGF signaling due to the lack of predictive biomarkers. In this review, we will describe the IGF system, rationale for targeting IGF signaling, the potential liabilities of targeting strategies, and potential biomarkers that may improve success. PMID:26217584

Data and methods for studying commercial motor vehicle driver fatigue, highway safety and long-term driver health.

PubMed

Stern, Hal S; Blower, Daniel; Cohen, Michael L; Czeisler, Charles A; Dinges, David F; Greenhouse, Joel B; Guo, Feng; Hanowski, Richard J; Hartenbaum, Natalie P; Krueger, Gerald P; Mallis, Melissa M; Pain, Richard F; Rizzo, Matthew; Sinha, Esha; Small, Dylan S; Stuart, Elizabeth A; Wegman, David H

2018-03-09

This article summarizes the recommendations on data and methodology issues for studying commercial motor vehicle driver fatigue of a National Academies of Sciences, Engineering, and Medicine study. A framework is provided that identifies the various factors affecting driver fatigue and relating driver fatigue to crash risk and long-term driver health. The relevant factors include characteristics of the driver, vehicle, carrier and environment. Limitations of existing data are considered and potential sources of additional data described. Statistical methods that can be used to improve understanding of the relevant relationships from observational data are also described. The recommendations for enhanced data collection and the use of modern statistical methods for causal inference have the potential to enhance our understanding of the relationship of fatigue to highway safety and to long-term driver health. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Predicting potentially plant-available lead in contaminated residential sites.

PubMed

Andra, Syam S; Sarkar, Dibyendu; Saminathan, Sumathi K M; Datta, Rupali

2011-04-01

Lead (Pb)-based paints pose a serious health problem to people living in residential settings constructed prior to 1978. Children are at a greater risk to Pb exposure resulting from hand-to-mouth activity in Pb-contaminated residential soils. For soil Pb, the most environmentally friendly, potentially cheap, and visually unobtrusive in situ technology is phytoremediation. However, the limiting factor in a successful phytoremediation strategy is the availability of Pb for plant uptake. The purpose of this study was to establish a relationship between soil properties and the plant-available/exchangeable Pb fraction in the selected Pb-based paint-contaminated residential sites. We selected 20 such sites from two different locations (San Antonio, Texas and Baltimore, Maryland) with varying soil properties and total soil Pb concentrations ranging between 256 and 4,182 mg kg(-1). Despite higher Pb levels in these soils that exceeds US EPA permissible limit of 400 mg kg(-1), it is known that the plant-available Pb pools are significantly lower because of their sorption to soil components such as organic matter, Fe-Mn oxides, and clays, and their precipitation in the form of carbonates, hydroxides, and phosphates. Principal component analysis and hierarchical clustering showed that the potentially plant-available Pb fraction is controlled by soil pH in the case of acidic Baltimore soils, while soil organic matter plays a major role in alkaline San Antonio soils. Statistical models developed suggest that Pb is likely to be more available for plant uptake in Baltimore soils and a chelant-assisted phytoextraction strategy will be potentially necessary for San Antonio soils in mobilizing Pb from complexed pool to the plant-available pool. A thorough knowledge of site-specific factors is therefore essential in developing a suitable and successful phytoremediation model.

Validation to Portuguese of the Scale of Student Satisfaction and Self-Confidence in Learning.

PubMed

Almeida, Rodrigo Guimarães dos Santos; Mazzo, Alessandra; Martins, José Carlos Amado; Baptista, Rui Carlos Negrão; Girão, Fernanda Berchelli; Mendes, Isabel Amélia Costa

2015-01-01

Translate and validate to Portuguese the Scale of Student Satisfaction and Self-Confidence in Learning. Methodological translation and validation study of a research tool. After following all steps of the translation process, for the validation process, the event III Workshop Brazil - Portugal: Care Delivery to Critical Patients was created, promoted by one Brazilian and another Portuguese teaching institution. 103 nurses participated. As to the validity and reliability of the scale, the correlation pattern between the variables, the sampling adequacy test (Kaiser-Meyer-Olkin) and the sphericity test (Bartlett) showed good results. In the exploratory factorial analysis (Varimax), item 9 behaved better in factor 1 (Satisfaction) than in factor 2 (Self-confidence in learning). The internal consistency (Cronbach's alpha) showed coefficients of 0.86 in factor 1 with six items and 0.77 for factor 2 with 07 items. In Portuguese this tool was called: Escala de Satisfação de Estudantes e Autoconfiança na Aprendizagem. The results found good psychometric properties and a good potential use. The sampling size and specificity are limitations of this study, but future studies will contribute to consolidate the validity of the scale and strengthen its potential use.

Going outdoors and cognitive function among community-dwelling older adults: Moderating role of physical function.

PubMed

Harada, Kazuhiro; Lee, Sangyoon; Park, Hyuntae; Shimada, Hiroyuki; Makizako, Hyuma; Doi, Takehiko; Yoshida, Daisuke; Tsutsumimoto, Kota; Anan, Yuya; Uemura, Kazuki; Suzuki, Takao

2016-01-01

Identifying the risk factors of cognitive impairment is essential for implementing effective prevention strategies for dementia. Previous studies have shown that the frequency of going outdoors is inversely associated with cognitive decline. Little research has examined whether the relationship between going outdoors and cognitive decline varies with physical functioning in older adults. The aim of the present study was to examine the relationship between going outdoors and cognitive function in older adults with and without physical function limitations. The present study analyzed the data of 4450 individuals (aged 65 years or older) who participated in the Obu Study of Health Promotion for the Elderly. The measures were the Mini-Mental State Examination (MMSE), going outdoors (at least once a week or not), self-reported physical function limitations (with or without), and demographic and health-related factors as potential confounders. Analysis of covariance and post-hoc comparisons showed that although going outdoors at least once a week was associated with higher MMSE scores among older adults with limited physical function, it was not significantly associated with the MMSE scores among older adults without limited physical function. Similarly, logistic regression analyses, stratified by physical function, showed a significant association between going outdoors and MMSE (<24 points or not) among older adults with limited physical function. The results show that going outdoors less than once a week is associated with decreased cognitive function among older adults with limited physical function, but it is not associated with cognitive function among older adults without limited physical function. © 2015 Japan Geriatrics Society.

An underdamped stochastic resonance method with stable-state matching for incipient fault diagnosis of rolling element bearings

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Qiao, Zijian; Xu, Xuefang; Lin, Jing; Niu, Shantao

2017-09-01

Most traditional overdamped monostable, bistable and even tristable stochastic resonance (SR) methods have three shortcomings in weak characteristic extraction: (1) their potential structures characterized by single stable-state type are insufficient to match with the complicated and diverse mechanical vibration signals; (2) they vulnerably suffer the interference from multiscale noise and largely depend on the help of highpass filters whose parameters are selected subjectively, probably resulting in false detection; and (3) their rescaling factors are fixed as constants generally, thereby ignoring the synergistic effect among vibration signals, potential structures and rescaling factors. These three shortcomings have limited the enhancement ability of SR. To explore the SR potential, this paper initially investigates the SR in a multistable system by calculating its output spectral amplification, further analyzes its output frequency response numerically, then examines the effect of both damping and rescaling factors on output responses and finally presents a promising underdamped SR method with stable-state matching for incipient bearing fault diagnosis. This method has three advantages: (1) the diversity of stable-state types in a multistable potential makes it easy to match with various vibration signals; (2) the underdamped multistable SR, equivalent to a moving nonlinear bandpass filter that is dependent on the rescaling factors, is able to suppress the multiscale noise; and (3) the synergistic effect among vibration signals, potential structures and rescaling and damping factors is achieved using quantum genetic algorithms whose fitness functions are new weighted signal-to-noise ratio (WSNR) instead of SNR. Therefore, the proposed method is expected to possess good enhancement ability. Simulated and experimental data of rolling element bearings demonstrate its effectiveness. The comparison results show that the proposed method is able to obtain higher amplitude at target frequency and larger output WSNR, and performs better than traditional SR methods.

Hypertension in the US Black population: risk factors, complications, and potential impact of central aortic pressure on effective treatment.

PubMed

Ferdinand, Keith C; Townsend, Raymond R

2012-04-01

The identification of specific factors that contribute to hypertension development and progression among blacks in the US is the focus of much ongoing research. The purpose of this paper is to review these factors and discuss how they present unique opportunities for improving the management of hypertension in this difficult-to-treat population. We searched the published literature for articles discussing the risk factors for hypertension and cardiovascular disease in blacks; the target-organ damage and cardiovascular complications associated with hypertension in this difficult-to-treat population; and the role of central blood pressure in predicting cardiovascular events. The prevalence of hypertension is higher in blacks than in other race/ethnic groups, with environmental and genetic risk factors likely playing an important role. The cardiovascular and renal consequences of hypertension (eg, left ventricular hypertrophy and renal failure) are also greater in blacks relative to their white counterparts. Preliminary data suggest that central blood pressure may be higher in blacks than in whites and has the potential for greater prognostic capability relative to peripheral blood pressure. There is an urgent need to successfully control hypertension in the black population. Although data are limited in blacks, evidence suggests that central blood pressure warrants more continued assessment in future clinical studies.

The Skin Picking Impact Scale: Factor structure, validity and development of a short version.

PubMed

Snorrason, Ivar; Olafsson, Ragnar P; Flessner, Christopher A; Keuthen, Nancy J; Franklin, Martin E; Woods, Douglas W

2013-08-01

In the present study, we examined the psychometric properties of the Skin Picking Impact Scale (SPIS; Keuthen, Deckersbach, Wilhelm et al., 2001), a 10 item self-report questionnaire designed to assess the psychosocial impact of skin picking disorder (SPD). Participants were 650 individuals who met criteria for SPD in an online survey. Exploratory and confirmatory factor analyses demonstrated a unitary factor structure with high internal consistency (α = 0.94). Consequently, we constructed an abbreviated 4-item version that retained good internal consistency (α = 0.87) and a robust factor structure. Both the short and the full versions demonstrated discriminant and convergent/concurrent validity. In conclusion, the findings indicate that both versions are psychometrically sound measures of SPD related psychosocial impact; however, some potential limitations of the full scale are discussed. © 2013 The Scandinavian Psychological Associations.

Pollen limitation and reduced reproductive success are associated with local genetic effects in Prunus virginiana, a widely distributed self-incompatible shrub.

PubMed

Suarez-Gonzalez, Adriana; Good, Sara V

2014-03-01

A vast quantity of empirical evidence suggests that insufficient quantity or quality of pollen may lead to a reduction in fruit set, in particular for self-incompatible species. This study uses an integrative approach that combines field research with marker gene analysis to understand the factors affecting reproductive success in a widely distributed self-incompatible species, Prunus virginiana (Rosaceae). Twelve patches of P. virginiana distributed within three populations that differed in degree of disturbance were examined. Two of the sites were small (7-35 km(2)) remnants of forest in an intensively used agricultural landscape, while the third was continuous (350 km(2)) and less disturbed. Field studies (natural and hand cross-pollinations) were combined with marker gene analyses (microsatellites and S-locus) in order to explore potential factors affecting pollen delivery and consequently reproductive success at landscape (between populations) and fine scales (within populations). Reductions in reproductive output were found in the two fragments compared with the continuous population, and suggest that pollen is an important factor limiting fruit production. Genetic analyses carried out in one of the fragments and in the continuous site suggest that even though S-allele diversity is high in both populations, the fragment exhibits an increase in biparental inbreeding and correlated paternity. The increase in biparental inbreeding in the fragment is potentially attributable to variation in the density of individuals and/or the spatial distribution of genotypes among populations, both of which could alter mating dynamics. By using a novel integrative approach, this study shows that even though P. virginiana is a widespread species, fragmented populations can experience significant reductions in fruit set and pollen limitation in the field. Deatiled examination of one fragmented population suggests that these linitations may be explained by an increase in biparental inbreeding, correlated paternity and fine-scale genetic structure. The consistency of the field and fine-scale genetic analyses, and the consistency of the results within patches and across years, suggest that these are important processes driving pollen limitation in the fragment.

Pollen limitation and reduced reproductive success are associated with local genetic effects in Prunus virginiana, a widely distributed self-incompatible shrub

PubMed Central

Suarez-Gonzalez, Adriana; Good, Sara V.

2014-01-01

Background and Aims A vast quantity of empirical evidence suggests that insufficient quantity or quality of pollen may lead to a reduction in fruit set, in particular for self-incompatible species. This study uses an integrative approach that combines field research with marker gene analysis to understand the factors affecting reproductive success in a widely distributed self-incompatible species, Prunus virginiana (Rosaceae). Methods Twelve patches of P. virginiana distributed within three populations that differed in degree of disturbance were examined. Two of the sites were small (7–35 km2) remnants of forest in an intensively used agricultural landscape, while the third was continuous (350 km2) and less disturbed. Field studies (natural and hand cross-pollinations) were combined with marker gene analyses (microsatellites and S-locus) in order to explore potential factors affecting pollen delivery and consequently reproductive success at landscape (between populations) and fine scales (within populations). Key Results Reductions in reproductive output were found in the two fragments compared with the continuous population, and suggest that pollen is an important factor limiting fruit production. Genetic analyses carried out in one of the fragments and in the continuous site suggest that even though S-allele diversity is high in both populations, the fragment exhibits an increase in biparental inbreeding and correlated paternity. The increase in biparental inbreeding in the fragment is potentially attributable to variation in the density of individuals and/or the spatial distribution of genotypes among populations, both of which could alter mating dynamics. Conclusions By using a novel integrative approach, this study shows that even though P. virginiana is a widespread species, fragmented populations can experience significant reductions in fruit set and pollen limitation in the field. Deatiled examination of one fragmented population suggests that these linitations may be explained by an increase in biparental inbreeding, correlated paternity and fine-scale genetic structure. The consistency of the field and fine-scale genetic analyses, and the consistency of the results within patches and across years, suggest that these are important processes driving pollen limitation in the fragment. PMID:24327534

Marital Quality and Cognitive Limitations in Late Life

PubMed Central

Thomas, Patricia A.; Umberson, Debra

2016-01-01

Objectives. Identifying factors associated with cognitive limitations among older adults has become a major public health objective. Given the importance of marital relationships for older adults’ health, this study examines the association between marital quality and change in cognitive limitations in late life, directionality of the relationship between marital quality and cognitive limitations, and potential gender differences in these associations. Method. Latent growth curve models were used to estimate the association of marital quality with change in cognitive limitations among older adults and the direction of the association between marital quality and cognitive limitations using 4 waves of the Americans’ Changing Lives survey (N = 841). Results. Results indicate that more frequent negative (but not positive) marital experiences are associated with a slower increase in cognitive limitations over time, and the direction of this association does not operate in the reverse (i.e., cognitive limitations did not lead to change in marital quality over time). The association between negative marital experiences and cognitive limitations is similar for men and women. Discussion. The discussion highlights possible explanations for the apparent protective effect of negative marital experiences for older adults’ cognitive health over time, regardless of gender. PMID:25765315

The potential for iron reduction in upland soils in Calhoun Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Thompson, A.; Chen, C.; Noor, N.; Hodges, C. A.; Barcellos, D.; Richter, D. D., Jr.

2017-12-01

Fe redox cycling plays an important role in organic matter preservation and degradation, and the fate of nutrients and contaminants. Despite its importance, Fe redox cycling in non-flooded upland soils has been underappreciated, although many upland terrestrial ecosystems have episodes of low redox events and an abundance of anoxic microsites. Soil Fe reduction is generally constrained by C availability, the reactivity of Fe(III) oxyhydroxides, and the abundance of Fe reducing bacteria. The goal of this study was to determine the potential for Fe reduction in upland soils under varying land-uses (Hardwood, Pine and Cultivated soils) from Calhoun Critical Zone Observatory. Fresh field soils from multiple depths were incubated in the lab without amendments under anoxic conditions for 3 weeks to determine the native potential for soil Fe reduction and to assess the limiting factors, the soils were amended with factorial mixtures of the following: (1) organic substrates (glucose and alanine); (2) bioavailable Fe (ferrihydrite); and (3) Fe reducing bacteria (Shewanella oneidensis strain MR-1). Results showed that Fe reduction potential generally decreased with soil depth. Fe reduction potential is very minimal below 1m of soil profile. The availability of Fe(III) minerals did not constrain pine and hardwood soil Fe reduction potential. Fe(III) availability only slightly limited the potential for Fe reduction the cultivated soils, which have the lowest extractable Fe by ascorbate-citrate. Labile C constrained Fe reduction in the hardwood and cultivated soils, but not in the pine soils, which had the highest extractable C by K2SO4. In addition, we found the more energetic C source (glucose) facilitated more Fe reduction in the subsurface soil than did Alanine. Finally, the abundance of Fe-reducing bacteria limited Fe reduction potential in almost all of these soils, particularly the pine soils.

Predicting the potential distribution of the amphibian pathogen Batrachochytrium dendrobatidis in East and Southeast Asia.

PubMed

Moriguchi, Sachiko; Tominaga, Atsushi; Irwin, Kelly J; Freake, Michael J; Suzuki, Kazutaka; Goka, Koichi

2015-04-08

Batrachochytrium dendrobatidis (Bd) is the pathogen responsible for chytridiomycosis, a disease that is associated with a worldwide amphibian population decline. In this study, we predicted the potential distribution of Bd in East and Southeast Asia based on limited occurrence data. Our goal was to design an effective survey area where efforts to detect the pathogen can be focused. We generated ecological niche models using the maximum-entropy approach, with alleviation of multicollinearity and spatial autocorrelation. We applied eigenvector-based spatial filters as independent variables, in addition to environmental variables, to resolve spatial autocorrelation, and compared the model's accuracy and the degree of spatial autocorrelation with those of a model estimated using only environmental variables. We were able to identify areas of high suitability for Bd with accuracy. Among the environmental variables, factors related to temperature and precipitation were more effective in predicting the potential distribution of Bd than factors related to land use and cover type. Our study successfully predicted the potential distribution of Bd in East and Southeast Asia. This information should now be used to prioritize survey areas and generate a surveillance program to detect the pathogen.

14 CFR 25.337 - Limit maneuvering load factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factors. 25.337... Conditions § 25.337 Limit maneuvering load factors. (a) Except where limited by maximum (static) lift... maneuvering load factors prescribed in this section. Pitching velocities appropriate to the corresponding pull...

Physiological tolerance and stoichiometric potential of cyanobacteria for hydrocarbon fuel production.

PubMed

Kämäräinen, Jari; Knoop, Henning; Stanford, Natalie J; Guerrero, Fernando; Akhtar, M Kalim; Aro, Eva-Mari; Steuer, Ralf; Jones, Patrik R

2012-11-30

Cyanobacteria are capable of directly converting sunlight, carbon dioxide and water into hydrocarbon fuel or precursors thereof. Many biological and non-biological factors will influence the ability of such a production system to become economically sustainable. We evaluated two factors in engineerable cyanobacteria which could potentially limit economic sustainability: (i) tolerance of the host to the intended end-product, and (ii) stoichiometric potential for production. Alcohols, when externally added, inhibited growth the most, followed by aldehydes and acids, whilst alkanes were the least inhibitory. The growth inhibition became progressively greater with increasing chain-length for alcohols, whilst the intermediate C6 alkane caused more inhibition than both C3 and C11 alkane. Synechocystis sp. PCC 6803 was more tolerant to some of the tested chemicals than Synechococcus elongatus PCC 7942, particularly ethanol and undecane. Stoichiometric evaluation of the potential yields suggested that there is no difference in the potential productivity of harvestable energy between any of the studied fuels, with the exception of ethylene, for which maximal stoichiometric yield is considerably lower. In summary, it was concluded that alkanes would constitute the best choice metabolic end-product for fuel production using cyanobacteria if high-yielding strains can be developed. Copyright © 2012 Elsevier B.V. All rights reserved.

Are workplace health promotion programs effective at improving presenteeism in workers? A systematic review and best evidence synthesis of the literature.

PubMed

Cancelliere, Carol; Cassidy, J David; Ammendolia, Carlo; Côté, Pierre

2011-05-26

Presenteeism is highly prevalent and costly to employers. It is defined as being present at work, but limited in some aspect of job performance by a health problem.Workplace health promotion (WHP) is a common strategy used to enhance on-the-job productivity. The primary objective is to determine if WHP programs are effective in improving presenteeism. The secondary objectives are to identify characteristics of successful programs and potential risk factors for presenteeism. The Cochrane Library, Medline, and other electronic databases were searched from 1990 to 2010. Reference lists were examined, key journals were hand-searched and experts were contacted. Included studies were original research that contained data on at least 20 participants (≥ 18 years of age), and examined the impacts of WHP programs implemented at the workplace. The Effective Public Health Practice Project Tool for Quantitative Studies was used to rate studies. 'Strong' and 'moderate' studies were abstracted into evidence tables, and a best evidence synthesis was performed. Interventions were deemed successful if they improved the outcome of interest. Their program components were identified, as were possible risk factors contributing to presenteeism. After 2,032 titles and abstracts were screened, 47 articles were reviewed, and 14 were accepted (4 strong and 10 moderate studies). These studies contained preliminary evidence for a positive effect of some WHP programs. Successful programs offered organizational leadership, health risk screening, individually tailored programs, and a supportive workplace culture. Potential risk factors contributing to presenteeism included being overweight, a poor diet, a lack of exercise, high stress, and poor relations with co-workers and management. This review is limited to English publications. A large number of reviewed studies (70%) were inadmissible due to issues of bias, thus limiting the amount of primary evidence. The uncertainties surrounding presenteeism measurement is of significant concern as a source of bias. The presenteeism literature is young and heterogeneous. There is preliminary evidence that some WHP programs can positively affect presenteeism and that certain risk factors are of importance. Future research would benefit from standard presenteeism metrics and studies conducted across a broad range of workplace settings.

Temperature drives abundance fluctuations, but spatial dynamics is constrained by landscape configuration: Implications for climate-driven range shift in a butterfly.

PubMed

Fourcade, Yoan; Ranius, Thomas; Öckinger, Erik

2017-10-01

Prediction of species distributions in an altered climate requires knowledge on how global- and local-scale factors interact to limit their current distributions. Such knowledge can be gained through studies of spatial population dynamics at climatic range margins. Here, using a butterfly (Pyrgus armoricanus) as model species, we first predicted based on species distribution modelling that its climatically suitable habitats currently extend north of its realized range. Projecting the model into scenarios of future climate, we showed that the distribution of climatically suitable habitats may shift northward by an additional 400 km in the future. Second, we used a 13-year monitoring dataset including the majority of all habitat patches at the species northern range margin to assess the synergetic impact of temperature fluctuations and spatial distribution of habitat, microclimatic conditions and habitat quality, on abundance and colonization-extinction dynamics. The fluctuation in abundance between years was almost entirely determined by the variation in temperature during the species larval development. In contrast, colonization and extinction dynamics were better explained by patch area, between-patch connectivity and host plant density. This suggests that the response of the species to future climate change may be limited by future land use and how its host plants respond to climate change. It is, thus, probable that dispersal limitation will prevent P. armoricanus from reaching its potential future distribution. We argue that models of range dynamics should consider the factors influencing metapopulation dynamics, especially at the range edges, and not only broad-scale climate. It includes factors acting at the scale of habitat patches such as habitat quality and microclimate and landscape-scale factors such as the spatial configuration of potentially suitable patches. Knowledge of population dynamics under various environmental conditions, and the incorporation of realistic scenarios of future land use, appears essential to provide predictions useful for actions mitigating the negative effects of climate change. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Cell reprogramming: Therapeutic potential and the promise of rejuvenation for the aging brain.

PubMed

López-León, Micaela; Outeiro, Tiago F; Goya, Rodolfo G

2017-11-01

Aging is associated with a progressive increase in the incidence of neurodegenerative diseases, with Alzheimer's (AD) and Parkinson's (PD) disease being the most conspicuous examples. Within this context, the absence of efficacious therapies for most age-related brain pathologies has increased the interest in regenerative medicine. In particular, cell reprogramming technologies have ushered in the era of personalized therapies that not only show a significant potential for the treatment of neurodegenerative diseases but also promise to make biological rejuvenation feasible. We will first review recent evidence supporting the emerging view that aging is a reversible epigenetic phenomenon. Next, we will describe novel reprogramming approaches that overcome some of the intrinsic limitations of conventional induced-pluripotent-stem-cell technology. One of the alternative approaches, lineage reprogramming, consists of the direct conversion of one adult cell type into another by transgenic expression of multiple lineage-specific transcription factors (TF). Another strategy, termed pluripotency factor-mediated direct reprogramming, uses universal TF to generate epigenetically unstable intermediates able to differentiate into somatic cell types in response to specific differentiation factors. In the third part we will review studies showing the potential relevance of the above approaches for the treatment of AD and PD. Copyright © 2017 Elsevier B.V. All rights reserved.

Good people who try their best can have problems: recognition of human factors and how to minimise error.

PubMed

Brennan, Peter A; Mitchell, David A; Holmes, Simon; Plint, Simon; Parry, David

2016-01-01

Human error is as old as humanity itself and is an appreciable cause of mistakes by both organisations and people. Much of the work related to human factors in causing error has originated from aviation where mistakes can be catastrophic not only for those who contribute to the error, but for passengers as well. The role of human error in medical and surgical incidents, which are often multifactorial, is becoming better understood, and includes both organisational issues (by the employer) and potential human factors (at a personal level). Mistakes as a result of individual human factors and surgical teams should be better recognised and emphasised. Attitudes and acceptance of preoperative briefing has improved since the introduction of the World Health Organization (WHO) surgical checklist. However, this does not address limitations or other safety concerns that are related to performance, such as stress and fatigue, emotional state, hunger, awareness of what is going on situational awareness, and other factors that could potentially lead to error. Here we attempt to raise awareness of these human factors, and highlight how they can lead to error, and how they can be minimised in our day-to-day practice. Can hospitals move from being "high risk industries" to "high reliability organisations"? Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Performance-based versus patient-reported physical function: what are the underlying predictors?

PubMed

Bean, Jonathan F; Olveczky, Daniele D; Kiely, Dan K; LaRose, Sharon I; Jette, Alan M

2011-12-01

Functional limitations have been operationally defined for studies of rehabilitation science through measures of physical performance and patient-reported function. Although conceived as representing similar concepts, differences between these 2 modes of measuring physical functioning have not been adequately characterized scientifically. The purpose of this study was to compare the Short Physical Performance Battery (SPPB) with the function component of the Late-Life Function and Disability Instrument (LLFDI) with respect to their association with physiologic factors and other psychosocial and health factors potentially influencing rehabilitative care. This study was a cross-sectional analysis of baseline data from a sample of community-dwelling older adults (N=137) with mobility limitations enrolled in a randomized controlled trial of exercise. A performance-based measure of function (the SPPB) and a self-report measure of function (the LLFDI) served as functional outcomes. Physiologic factors included measures of leg strength, leg velocity, and exercise tolerance test (ETT) duration, which served as a surrogate measure of aerobic capacity. Psychosocial and health factors included age, sex, height, body mass index, number of chronic conditions, depression, and falls efficacy. Separate multivariable regression models predicting SPPB and LLFDI scores described 33% and 42% of the variance in each outcome (R(2)), respectively. Leg velocity and ETT duration were positively associated with both performance-based and patient-reported functional measures. Leg strength and age were positively associated with SPPB scores, whereas number of chronic conditions, sex, and falls efficacy were associated with the LLFDI scores. This study included older adults with mobility limitations and may not generalize to other populations. Performance-based and patient-reported measures of physical function appear to assess different aspects of an older person's functioning. The SPPB was associated with age and physiologic factors, whereas patient-reported function measured by the LLFDI was associated with these factors as well as with psychosocial and health factors.

The effect of water temperature and flow on respiration in barnacles: patterns of mass transfer versus kinetic limitation.

PubMed

Nishizaki, Michael T; Carrington, Emily

2014-06-15

In aquatic systems, physiological processes such as respiration, photosynthesis and calcification are potentially limited by the exchange of dissolved materials between organisms and their environment. The nature and extent of physiological limitation is, therefore, likely to be dependent on environmental conditions. Here, we assessed the metabolic sensitivity of barnacles under a range of water temperatures and velocities, two factors that influence their distribution. Respiration rates increased in response to changes in temperature and flow, with an interaction where flow had less influence on respiration at low temperatures, and a much larger effect at high temperatures. Model analysis suggested that respiration is mass transfer limited under conditions of low velocity (<7.5 cm (-1)) and high temperature (20-25°C). In contrast, limitation by uptake reaction kinetics, when the biotic capacity of barnacles to absorb and process oxygen is slower than its physical delivery by mass transport, prevailed at high flows (40-150 cm s(-1)) and low temperatures (5-15°C). Moreover, there are intermediate flow-temperature conditions where both mass transfer and kinetic limitation are important. Behavioral monitoring revealed that barnacles fully extend their cirral appendages at low flows and display abbreviated 'testing' behaviors at high flows, suggesting some form of mechanical limitation. In low flow-high temperature treatments, however, barnacles displayed distinct 'pumping' behaviors that may serve to increase ventilation. Our results suggest that in slow-moving waters, respiration may become mass transfer limited as temperatures rise, whereas faster flows may serve to ameliorate the effects of elevated temperatures. Moreover, these results underscore the necessity for approaches that evaluate the combined effects of multiple environmental factors when examining physiological and behavioral performance. © 2014. Published by The Company of Biologists Ltd.

Beyond Correlates: A Review of Risk and Protective Factors for Adolescent Dating Violence Perpetration

PubMed Central

Vagi, Kevin J.; Rothman, Emily; Latzman, Natasha E.; Tharp, Andra Teten; Hall, Diane M.; Breiding, Matthew J.

2013-01-01

Dating violence is a serious public health problem. In recent years, the U.S. Centers for Disease Control and Prevention (CDC) and other entities have made funding available to community based agencies for dating violence prevention. Practitioners who are tasked with developing dating violence prevention strategies should pay particular attention to risk and protective factors for dating violence perpetration that have been established in longitudinal studies. This has been challenging to date because the scientific literature on the etiology of dating violence is somewhat limited, and because there have been no comprehensive reviews of the literature that clearly distinguish correlates of dating violence perpetration from risk or protective factors that have been established through longitudinal research. This is problematic because prevention programs may then target factors that are merely correlated with dating violence perpetration, and have no causal influence, which could potentially limit the effectiveness of the programs. In this article, we review the literature on risk and protective factors for adolescent dating violence perpetration and highlight those factors for which temporal precedence has been established by one or more studies. This review is intended as a guide for researchers and practitioners as they formulate prevention programs. We reviewed articles published between 2000–2010 that reported on adolescent dating violence perpetration using samples from the United States or Canada. In total, 53 risk factors and six protective factors were identified from 20 studies. Next steps for etiological research in adolescent dating violence are discussed, as well as future directions for prevention program developers. PMID:23385616

Ripple feedback for the resonant-filter unity-power-factor rectifier

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

Streng, S.A.; King, R.J.

1992-07-01

An unusual bucklike unity-power-factor rectifier with a resonant load-balancing network permits current-limited operation down to zero output voltage in a single-stage-topology. However, this rectifier has been found to be sensitive to ac-line voltage distortion and is potentially unstable with realistic values of ac-line impedance. In this paper, a new ripple feedback is proposed that solves both problems. A large-signal time-varying analysis is given along with incremental, quasi-static, and low-frequency approximations. Experimental verification is provided by a 500-W 50-kHz rectifier operating from the 120-V 60-Hz distribution system.

The Role of Lean Process Improvement in Implementation of Evidence-Based Practices in Behavioral Health Care.

PubMed

Steinfeld, Bradley; Scott, Jennifer; Vilander, Gavin; Marx, Larry; Quirk, Michael; Lindberg, Julie; Koerner, Kelly

2015-10-01

To effectively implement evidence-based practices (EBP) in behavioral health care, an organization needs to have operating structures and processes that can address core EBP implementation factors and stages. Lean, a widely used quality improvement process, can potentially address the factors crucial to successful implementation of EBP. This article provides an overview of Lean and the relationship between Lean process improvement steps, and EBP implementation models. Examples of how Lean process improvement methodologies can be used to help plan and carry out implementation of EBP in mental health delivery systems are presented along with limitations and recommendations for future research and clinical application.

Dependence of Coulomb Sum Rule on the Short Range Correlation by Using Av18 Potential

NASA Astrophysics Data System (ADS)

Modarres, M.; Moeini, H.; Moshfegh, H. R.

The Coulomb sum rule (CSR) and structure factor are calculated for inelastic electron scattering from nuclear matter at zero and finite temperature in the nonrelativistic limit. The effect of short-range correlation (SRC) is presented by using lowest order constrained variational (LOCV) method and the Argonne Av18 and Δ-Reid soft-core potentials. The effects of different potentials as well as temperature are investigated. It is found that the nonrelativistic version of Bjorken scaling approximately sets in at the momentum transfer of about 1.1 to 1.2 GeV/c and the increase of temperature makes it to decrease. While different potentials do not significantly change CSR, the SRC improves the Coulomb sum rule and we get reasonably close results to both experimental data and others theoretical predictions.

Neurophysiological effects of acute oxytocin administration: systematic review and meta-analysis of placebo-controlled imaging studies

PubMed Central

Wigton, Rebekah; Radua, Jocham; Allen, Paul; Averbeck, Bruno; Meyer-Lindenberg, Andreas; McGuire, Philip; Shergill, Sukhi S.; Fusar-Poli, Paolo

2015-01-01

Background Oxytocin (OXT) plays a prominent role in social cognition and may have clinical applications for disorders such as autism, schizophrenia and social anxiety. The neural basis of its mechanism of action remains unclear. Methods We conducted a systematic literature review of placebo-controlled imaging studies using OXT as a pharmacological manipulator of brain activity. Results We identified a total of 21 studies for inclusion in our review, and after applying additional selection criteria, 11 of them were included in our fMRI voxel-based meta-analysis. The results demonstrate consistent alterations in activation of brain regions, including the temporal lobes and insula, during the processing of social stimuli, with some variation dependent on sex and task. The meta-analysis revealed significant left insular hyperactivation after OXT administration, suggesting a potential modulation of neural circuits underlying emotional processing. Limitations This quantitative review included only a limited number of studies, thus the conclusions of our analysis should be interpreted cautiously. This limited sample size precluded a more detailed exploration of potential confounding factors, such as sex or other demographic factors, that may have affected our meta-analysis. Conclusion Oxytocin has a wide range of effects over neural activity in response to social and emotional processing, which is further modulated by sex and task specificity. The magnitude of this neural activation is largest in the temporal lobes, and a meta-analysis across all tasks and both sexes showed that the left insula demonstrated the most robust activation to OXT administration. PMID:25520163

Optical performance of hybrid porous silicon-porous alumina multilayers

NASA Astrophysics Data System (ADS)

Cencha, L. G.; Antonio Hernández, C.; Forzani, L.; Urteaga, R.; Koropecki, R. R.

2018-05-01

In this work, we study the optical response of structures involving porous silicon and porous alumina in a multi-layered hybrid structure. We performed a rational design of the optimal sequence necessary to produce a high transmission and selective filter, with potential applications in chemical and biosensors. The combination of these porous materials can be used to exploit its distinguishing features, i.e., high transparency of alumina and high refractive index of porous silicon. We assembled hybrid microcavities with a central porous alumina layer between two porous silicon Bragg reflectors. In this way, we constructed a Fabry-Perot resonator with high reflectivity and low absorption that improves the quality of the filter compared to a microcavity built only with porous silicon or porous alumina. We explored a simpler design in which one of the Bragg reflectors is replaced by the aluminium that remains bound to the alumina after its fabrication. We theoretically explored the potential of the proposal and its limitations when considering the roughness of the layers. We found that the quality of a microcavity made entirely with porous silicon shows a limit in the visible range due to light absorption. This limitation is overcome in the hybrid scheme, with the roughness of the layers determining the ultimate quality. Q-factors of 220 are experimentally obtained for microcavities supported on aluminium, while Q-factors around 600 are reached for microcavities with double Bragg reflectors, centred at 560 nm. This represents a four-fold increase with respect to the optimal porous silicon microcavity at this wavelength.

Capturing complexity in work disability research: application of system dynamics modeling methodology.

PubMed

Jetha, Arif; Pransky, Glenn; Hettinger, Lawrence J

2016-01-01

Work disability (WD) is characterized by variable and occasionally undesirable outcomes. The underlying determinants of WD outcomes include patterns of dynamic relationships among health, personal, organizational and regulatory factors that have been challenging to characterize, and inadequately represented by contemporary WD models. System dynamics modeling (SDM) methodology applies a sociotechnical systems thinking lens to view WD systems as comprising a range of influential factors linked by feedback relationships. SDM can potentially overcome limitations in contemporary WD models by uncovering causal feedback relationships, and conceptualizing dynamic system behaviors. It employs a collaborative and stakeholder-based model building methodology to create a visual depiction of the system as a whole. SDM can also enable researchers to run dynamic simulations to provide evidence of anticipated or unanticipated outcomes that could result from policy and programmatic intervention. SDM may advance rehabilitation research by providing greater insights into the structure and dynamics of WD systems while helping to understand inherent complexity. Challenges related to data availability, determining validity, and the extensive time and technical skill requirements for model building may limit SDM's use in the field and should be considered. Contemporary work disability (WD) models provide limited insight into complexity associated with WD processes. System dynamics modeling (SDM) has the potential to capture complexity through a stakeholder-based approach that generates a simulation model consisting of multiple feedback loops. SDM may enable WD researchers and practitioners to understand the structure and behavior of the WD system as a whole, and inform development of improved strategies to manage straightforward and complex WD cases.

BCS-Bose model of exotic superconductors: Generalized coherence length

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

Casas, M.; Getino, J.M.; de Llano, M.

1994-12-01

Analytic expressions are derived for the root-mean-square (rms) radius of a pair of fermions in a BCS many-fermion state in one, two, and three dimensions, in terms of the BCS gap energy and the associated chemical potential. These expressions are valid for any coupling strength of [ital any] pair interaction model implying a momentum-independent gap energy. The latter holds, e.g., for an attractive [delta] pair potential examined in the one-dimensional (1D) case (whose [ital N]-fermion ground state can be determined exactly) or for the BCS (electron-phonon) model interaction in any dimension. Weak-coupling and/or high-density limits for the rms radius aremore » identical in 1D, 2D, and 3D, and reduce to the familiar well-known Pippard result to within a factor of order unity. In contrast, strong-coupling and/or low-density limits coincide in 1D and 3D, but differ by a factor of order unity in the 2D limit, and in each case are essentially the size of a single, isolated pair. The 1D [delta] interaction McGuire-Yang-Gaudin many-fermion model is studied in detail. The interaction renormalization scheme of Miyake and of Randeria, Duan, and Shieh, and the BCS interaction model, both in 2D, are employed to analyze cuprate superconductor empirical results. Reasonable agreement between theoretical rms radii with experimental coherence lengths suggests that cuprates can be described moderately well as [ital weakly] [ital coupled] superconductors within the BCS-Bose formalism.« less

Factor structure and longitudinal measurement invariance of PHQ-9 for specialist mental health care patients with persistent major depressive disorder: Exploratory Structural Equation Modelling.

PubMed

Guo, Boliang; Kaylor-Hughes, Catherine; Garland, Anne; Nixon, Neil; Sweeney, Tim; Simpson, Sandra; Dalgleish, Tim; Ramana, Rajini; Yang, Min; Morriss, Richard

2017-09-01

The Patient Health Questionnaire-9 (PHQ-9) is a widely used instrument for measuring levels of depression in patients in clinical practice and academic research; its factor structure has been investigated in various samples, with limited evidence of measurement equivalence/invariance (ME/I) but not in patients with more severe depression of long duration. This study aims to explore the factor structure of the PHQ-9 and the ME/I between treatment groups over time for these patients. 187 secondary care patients with persistent major depressive disorder (PMDD) were recruited to a randomised controlled trial (RCT) with allocation to either a specialist depression team arm or a general mental health arm; their PHQ-9 score was measured at baseline, 3, 6, 9 and 12 months. Exploratory Structural Equational Modelling (ESEM) was performed to examine the factor structure for this specific patient group. ME/I between treatment arm at and across follow-up time were further explored by means of multiple-group ESEM approach using the best-fitted factor structure. A two-factor structure was evidenced (somatic and affective factor). This two-factor structure had strong factorial invariance between the treatment groups at and across follow up times. Participants were largely white British in a RCT with 40% attrition potentially limiting the study's generalisability. Not all two-factor modelling criteria were met at every time-point. PHQ-9 has a two-factor structure for PMDD patients, with strong measurement invariance between treatment groups at and across follow-up time, demonstrating its validity for RCTs and prospective longitudinal studies in chronic moderate to severe depression. Copyright © 2017. Published by Elsevier B.V.

Understanding participation by African Americans in cancer genetics research.

PubMed

McDonald, Jasmine A; Barg, Frances K; Weathers, Benita; Guerra, Carmen E; Troxel, Andrea B; Domchek, Susan; Bowen, Deborah; Shea, Judy A; Halbert, Chanita Hughes

2012-01-01

Understanding genetic factors that contribute to racial differences in cancer outcomes may reduce racial disparities in cancer morbidity and mortality. Achieving this goal will be limited by low rates of African American participation in cancer genetics research. We conducted a qualitative study with African American adults (n = 91) to understand attitudes about participating in cancer genetics research and to identify factors that are considered when making a decision about participating in this type of research. Participants would consider the potential benefits to themselves, family members, and their community when making a decision to participate in cancer genetics research. However, concerns about exploitation, distrust of researchers, and investigators' motives were also important to participation decisions. Individuals would also consider who has access to their personal information and what would happen to these data. Side effects, logistical issues, and the potential to gain knowledge about health issues were also described as important factors in decision making. African Americans may consider a number of ethical, legal, and social issues when making a decision to participate in cancer genetics research. These issues should be addressed as part of recruitment efforts.

Internet addiction, problematic internet use, nonproblematic internet use among Chinese adolescents: Individual, parental, peer, and sociodemographic correlates.

PubMed

Zhou, Nan; Cao, Hongjian; Li, Xiaomin; Zhang, Jintao; Yao, Yuanwei; Geng, Xiaomin; Lin, Xiuyun; Hou, Shumeng; Liu, Fenge; Chen, Xiaoli; Fang, Xiaoyi

2018-05-01

Internet addiction has been typically conceptualized as either a continuous construct or a dichotomous construct. Limited research has differentiated adolescents with problematic Internet use (PIU) from the Internet addiction group (IA) and/or nonproblematic Internet use group (NPIU) and examined the potential correlates. To fill this gap, based on data obtained from 956 Chinese adolescents (11-19 years, 47% male), this study examined if adolescents with PIU is a distinctive group from the IA and NPIU. This study also examined factors from different ecological levels that may differentiate among the three groups, including individual, parental, peer, and sociodemographic factors. Results indicated that IA, PIU, and NPIU differed significantly on scores of Young's Diagnostic Questionnaire (YDQ). Critical factors emerging from different ecological levels could differentiate between PIU and NPIU and between IA and NPIU. Such findings suggest that PIU may represent a distinct, intermediate group of Internet users. The potential theoretical and practical implications of identifying PIU were also discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A Review: Proteomics in Retinal Artery Occlusion, Retinal Vein Occlusion, Diabetic Retinopathy and Acquired Macular Disorders.

PubMed

Cehofski, Lasse Jørgensen; Honoré, Bent; Vorum, Henrik

2017-04-28

Retinal artery occlusion (RAO), retinal vein occlusion (RVO), diabetic retinopathy (DR) and age-related macular degeneration (AMD) are frequent ocular diseases with potentially sight-threatening outcomes. In the present review we discuss major findings of proteomic studies of RAO, RVO, DR and AMD, including an overview of ocular proteome changes associated with anti-vascular endothelial growth factor (VEGF) treatments. Despite the severe outcomes of RAO, the proteome of the disease remains largely unstudied. There is also limited knowledge about the proteome of RVO, but proteomic studies suggest that RVO is associated with remodeling of the extracellular matrix and adhesion processes. Proteomic studies of DR have resulted in the identification of potential therapeutic targets such as carbonic anhydrase-I. Proliferative diabetic retinopathy is the most intensively studied stage of DR. Proteomic studies have established VEGF, pigment epithelium-derived factor (PEDF) and complement components as key factors associated with AMD. The aim of this review is to highlight the major milestones in proteomics in RAO, RVO, DR and AMD. Through large-scale protein analyses, proteomics is bringing new important insights into these complex pathological conditions.

Gene polymorphisms associated with functional dyspepsia.

PubMed

Kourikou, Anastasia; Karamanolis, George P; Dimitriadis, George D; Triantafyllou, Konstantinos

2015-07-07

Functional dyspepsia (FD) is a constellation of functional upper abdominal complaints with poorly elucidated pathophysiology. However, there is increasing evidence that susceptibility to FD is influenced by hereditary factors. Genetic association studies in FD have examined genotypes related to gastrointestinal motility or sensation, as well as those related to inflammation or immune response. G-protein b3 subunit gene polymorphisms were first reported as being associated with FD. Thereafter, several gene polymorphisms including serotonin transporter promoter, interlukin-17F, migration inhibitory factor, cholecystocynine-1 intron 1, cyclooxygenase-1, catechol-o-methyltransferase, transient receptor potential vanilloid 1 receptor, regulated upon activation normal T cell expressed and secreted, p22PHOX, Toll like receptor 2, SCN10A, CD14 and adrenoreceptors have been investigated in relation to FD; however, the results are contradictory. Several limitations underscore the value of current studies. Among others, inconsistencies in the definitions of FD and controls, subject composition differences regarding FD subtypes, inadequate samples, geographical and ethnical differences, as well as unadjusted environmental factors. Further well-designed studies are necessary to determine how targeted genes polymorphisms, influence the clinical manifestations and potentially the therapeutic response in FD.

Risk factors affecting the severity of traffic accidents at Shanghai river-crossing tunnel.

PubMed

Lu, Jian John; Xing, Yingying; Wang, Chen; Cai, Xiaonan

2016-01-01

With increasing traffic volume and urban development, increasing numbers of underground tunnels have been constructed to relieve conflict between strained land and heavy traffic. However, as more long tunnels are constructed, tunnel traffic safety is becoming increasingly serious. Thus, it is necessary to acquire their implications and impacts. This study examined 4,539 traffic accidents that have occurred in 14 Shanghai river-crossing tunnels for the period 2011-2012 and analyze the correlation between potential factors and accident injury severity. An ordered logit model was developed to examine the correlation between potential factors and accident injury severity. Results show that increased injury severity is associated with male drivers, drivers aged 65 years or older, accident time from midnight to dawn, weekends, wet road surface, goods vehicles, 3 or more vehicles, 4 or more lanes, middle speed limits (50-79 km/h), zone 3, extra-long tunnels (over 3,000 m), and maximum longitudinal gradient. This article aims to provide useful information for engineers to develop interventions and countermeasures to improve tunnel safety in China.

Numerical Computation of Homogeneous Slope Stability

PubMed Central

Xiao, Shuangshuang; Li, Kemin; Ding, Xiaohua; Liu, Tong

2015-01-01

To simplify the computational process of homogeneous slope stability, improve computational accuracy, and find multiple potential slip surfaces of a complex geometric slope, this study utilized the limit equilibrium method to derive expression equations of overall and partial factors of safety. This study transformed the solution of the minimum factor of safety (FOS) to solving of a constrained nonlinear programming problem and applied an exhaustive method (EM) and particle swarm optimization algorithm (PSO) to this problem. In simple slope examples, the computational results using an EM and PSO were close to those obtained using other methods. Compared to the EM, the PSO had a small computation error and a significantly shorter computation time. As a result, the PSO could precisely calculate the slope FOS with high efficiency. The example of the multistage slope analysis indicated that this slope had two potential slip surfaces. The factors of safety were 1.1182 and 1.1560, respectively. The differences between these and the minimum FOS (1.0759) were small, but the positions of the slip surfaces were completely different than the critical slip surface (CSS). PMID:25784927

Numerical computation of homogeneous slope stability.

PubMed

Xiao, Shuangshuang; Li, Kemin; Ding, Xiaohua; Liu, Tong

2015-01-01

To simplify the computational process of homogeneous slope stability, improve computational accuracy, and find multiple potential slip surfaces of a complex geometric slope, this study utilized the limit equilibrium method to derive expression equations of overall and partial factors of safety. This study transformed the solution of the minimum factor of safety (FOS) to solving of a constrained nonlinear programming problem and applied an exhaustive method (EM) and particle swarm optimization algorithm (PSO) to this problem. In simple slope examples, the computational results using an EM and PSO were close to those obtained using other methods. Compared to the EM, the PSO had a small computation error and a significantly shorter computation time. As a result, the PSO could precisely calculate the slope FOS with high efficiency. The example of the multistage slope analysis indicated that this slope had two potential slip surfaces. The factors of safety were 1.1182 and 1.1560, respectively. The differences between these and the minimum FOS (1.0759) were small, but the positions of the slip surfaces were completely different than the critical slip surface (CSS).

Alternative sources of pluripotency: science, ethics, and stem cells.

PubMed

Kastenberg, Zachary J; Odorico, Jon S

2008-07-01

Despite many advances in human embryonic stem cell (hESC) technology the ethical dilemma involving the destruction of a human embryo is one factor that has limited the development of hESC based clinical therapies. Two recent reports describing the production of pluripotent stem cells following the in vitro reprogramming of human somatic cells with certain defined factors illustrate one potential method of bypassing the ethical debate surrounding hESCs (Yu J, Vodyanik MA, Smuga-Otto K, et al. Induced pluripotent stem cell lines derived from human somatic cells. Science. 2007 Dec;318(5858):1917-1920; Takahashi K, Tanabe K, Ohnuki M, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007 Nov;131(5): 861-872.). Other alternative methods include nuclear transfer, altered nuclear transfer, and parthenogenesis; each with its own set of advantages and disadvantages. This review discusses recent advances in these technologies with specific focus on the issues of embryo destruction, oocyte recovery, and the potential of each technology to produce large scale, patient specific cell transplantation therapies that would require little or no immunosuppression.

Cardiometabolic Risk and Female Sexuality-Part I. Risk Factors and Potential Pathophysiological Underpinnings for Female Vasculogenic Sexual Dysfunction Syndromes.

PubMed

Maseroli, Elisa; Scavello, Irene; Vignozzi, Linda

2018-05-02

Erectile dysfunction is recognized as an opportunity for preventing cardiovascular (CV) events, and assessing the impairment of penile vascular flow by Doppler ultrasound is an important tool to ascertain CV risk. Conversely, the role of genital vascular impairment in the pathophysiology of female sexual dysfunction (FSD) remains contentious. To focus on the current scientific support for an association between CV risk factors and female sexual health in the 1st part of a 2-part review. A thorough literature search of peer-reviewed publications on the associations between CV risk factors and FSD and their underlying mechanisms was performed using the PubMed database. We present a summary of the evidence from clinical studies and discuss the possible mechanisms providing the pathophysiologic bases of vasculogenic FSD syndromes. The peripheral sexual response in women is a vascular-dependent event, and evidence suggests that cardiometabolic-related perturbations in endothelial function can determine vascular insufficiency in female genital tissues. Although epidemiologic and observational studies demonstrate that the prevalence of FSD is higher in women with diabetes mellitus, a cause-effect relation between these clinical conditions cannot be assumed. Evidence on the effect of obesity, metabolic syndrome, and polycystic ovary syndrome on sexual function in women is controversial. Data on the associations of dyslipidemia and hypertension with FSD are limited. Common cardiometabolic alterations could affect vascular function in the female genital tract. Based on limited data, there is an association between CV risk factors and female sexual health in women; however, this association appears milder than in men. Maseroli E, Scavello I, Vignozzi L. Cardiometabolic Risk and Female Sexuality-Part I. Risk Factors and Potential Pathophysiological Underpinnings for Female Vasculogenic Sexual Dysfunction Syndromes. Sex Med Rev 2018;X:XXX-XXX. Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

TFOS DEWS II Epidemiology Report.

PubMed

Stapleton, Fiona; Alves, Monica; Bunya, Vatinee Y; Jalbert, Isabelle; Lekhanont, Kaevalin; Malet, Florence; Na, Kyung-Sun; Schaumberg, Debra; Uchino, Miki; Vehof, Jelle; Viso, Eloy; Vitale, Susan; Jones, Lyndon

2017-07-01

The subcommittee reviewed the prevalence, incidence, risk factors, natural history, morbidity and questionnaires reported in epidemiological studies of dry eye disease (DED). A meta-analysis of published prevalence data estimated the impact of age and sex. Global mapping of prevalence was undertaken. The prevalence of DED ranged from 5 to 50%. The prevalence of signs was higher and more variable than symptoms. There were limited prevalence studies in youth and in populations south of the equator. The meta-analysis confirmed that prevalence increases with age, however signs showed a greater increase per decade than symptoms. Women have a higher prevalence of DED than men, although differences become significant only with age. Risk factors were categorized as modifiable/non-modifiable, and as consistent, probable or inconclusive. Asian ethnicity was a mostly consistent risk factor. The economic burden and impact of DED on vision, quality of life, work productivity, psychological and physical impact of pain, are considerable, particularly costs due to reduced work productivity. Questionnaires used to evaluate DED vary in their utility. Future research should establish the prevalence of disease of varying severity, the incidence in different populations and potential risk factors such as youth and digital device usage. Geospatial mapping might elucidate the impact of climate, environment and socioeconomic factors. Given the limited study of the natural history of treated and untreated DED, this remains an important area for future research. Copyright © 2017 Elsevier Inc. All rights reserved.

Insulin-like growth factor 1: common mediator of multiple enterotrophic hormones and growth factors.

PubMed

Bortvedt, Sarah F; Lund, P Kay

2012-03-01

To summarize the recent evidence that insulin-like growth factor 1 (IGF1) mediates growth effects of multiple trophic factors and discuss clinical relevance. Recent reviews and original reports indicate benefits of growth hormone (GH) and long-acting glucagon-like peptide 2 (GLP2) analogs in short bowel syndrome and Crohn's disease. This review highlights the evidence that biomarkers of sustained small intestinal growth or mucosal healing and evaluation of intestinal epithelial stem cell biomarkers may improve clinical measures of intestinal growth or response to trophic hormones. Compelling evidence that IGF1 mediates growth effects of GH and GLP2 on intestine or linear growth in preclinical models of resection or Crohn's disease is presented, along with a concept that these hormones or IGF1 may enhance sustained growth if given early after bowel resection. Evidence that suppressor of cytokine signaling protein induction by GH or GLP2 in normal or inflamed intestine may limit IGF1-induced growth, but protect against risk of dysplasia or fibrosis, is reviewed. Whether IGF1 receptor mediates IGF1 action and potential roles of insulin receptors are addressed. IGF1 has a central role in mediating trophic hormone action in small intestine. Better understanding of benefits and risks of IGF1, receptors that mediate IGF1 action, and factors that limit undesirable growth are needed.

Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy

PubMed Central

Kong, Cin; Neoh, Hui-min; Nathan, Sheila

2016-01-01

Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins. PMID:26999200

Modelling landscape-scale erosion potential related to vehicle disturbances along the U.S.-Mexico border

USGS Publications Warehouse

Villarreal, Miguel; Webb, Robert H.; Norman, Laura M.; Psillas, Jennifer L.; Rosenberg, Abigail S.; Carmichael, Shinji; Petrakis, Roy E.; Sparks, Philip E.

2014-01-01

Decades of intensive off-road vehicle use for border security, immigration, smuggling, recreation, and military training along the USA–Mexico border have prompted concerns about long-term human impacts on sensitive desert ecosystems. To help managers identify areas susceptible to soil erosion from anthropogenic activities, we developed a series of erosion potential models based on factors from the Universal Soil Loss Equation (USLE). To better express the vulnerability of soils to human disturbances, we refined two factors whose categorical and spatial representations limit the application of the USLE for non-agricultural landscapes: the C-factor (vegetation cover) and the P-factor (support practice/management). A soil compaction index (P-factor) was calculated as the difference in saturated hydrologic conductivity (Ks) between disturbed and undisturbed soils, which was then scaled up to maps of vehicle disturbances digitized from aerial photography. The C-factor was improved using a satellite-based vegetation index, which was better correlated with estimated ground cover (r2 = 0·77) than data derived from land cover (r2 = 0·06). We identified 9,780 km of unauthorized off-road tracks in the 2,800-km2 study area. Maps of these disturbances, when integrated with soil compaction data using the USLE, provided landscape-scale information on areas vulnerable to erosion from both natural processes and human activities and are detailed enough for adaptive management and restoration planning. The models revealed erosion potential hotspots adjacent to the border and within areas managed as critical habitat for the threatened flat-tailed horned lizard and endangered Sonoran pronghorn.

Pathways to potentially preventable hospitalizations for diabetes and heart failure: a qualitative analysis of patient perspectives.

PubMed

Sentell, Tetine L; Seto, Todd B; Young, Malia M; Vawer, May; Quensell, Michelle L; Braun, Kathryn L; Taira, Deborah A

2016-07-26

Potentially preventable hospitalizations (PPH) for heart failure (HF) and diabetes mellitus (DM) cost the United States over $14 billion annually. Studies about PPH typically lack patient perspectives, especially across diverse racial/ethnic groups with known PPH health disparities. English-speaking individuals with a HF or DM-related PPH (n = 90) at the largest hospital in Hawai'i completed an in-person interview, including open-ended questions on precipitating factors to their PPH. Using the framework approach, two independent coders identified patient-reported factors and pathways to their PPH. Seventy-two percent of respondents were under 65 years, 30 % were female, 90 % had health insurance, and 66 % had previously been hospitalized for the same problem. Patients' stories identified immediate, precipitating, and underlying reasons for the admission. Underlying background factors were critical to understanding why patients had the acute problems necessitating their hospitalizations. Six, non-exclusive, underlying factors included: extreme social vulnerability (e.g., homeless, poverty, no social support, reported by 54 % of respondents); health system interaction issues (e.g., poor communication with providers, 44 %); limited health-related knowledge (42 %); behavioral health issues (e.g., substance abuse, mental illness, 36 %); denial of illness (27 %); and practical problems (e.g., too busy, 6 %). From these findings, we developed a model to understand an individual's pathways to a PPH through immediate, precipitating, and underlying factors, which could help identify potential intervention foci. We demonstrate the model's utility using five examples. In a young, predominately insured population, factors well outside the traditional purview of the hospital, or even clinical medicine, critically influenced many PPH. Patient perspectives were vital to understanding this issue. Innovative partnerships and policies should address these issues, including linkages to social services and behavioral health.

Engineering growth factors for regenerative medicine applications.

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

Mitchell, Aaron C.; Briquez, Priscilla S.; Hubbell, Jeffrey A.

Growth factors are important morphogenetic proteins that instruct cell behavior and guide tissue repair and renewal. Although their therapeutic potential holds great promise in regenerative medicine applications, translation of growth factors into clinical treatments has been hindered by limitations including poor protein stability, low recombinant expression yield, and suboptimal efficacy. This review highlights current tools, technologies, and approaches to design integrated and effective growth factor-based therapies for regenerative medicine applications. The first section describes rational and combinatorial protein engineering approaches that have been utilized to improve growth factor stability, expression yield, biodistribution, and serum half-life, or alter their cell traffickingmore » behavior or receptor binding affinity. The second section highlights elegant biomaterial-based systems, inspired by the natural extracellular matrix milieu, that have been developed for effective spatial and temporal delivery of growth factors to cell surface receptors. Although appearing distinct, these two approaches are highly complementary and involve principles of molecular design and engineering to be considered in parallel when developing optimal materials for clinical applications.« less

Bioinformatics approaches to predict target genes from transcription factor binding data.

PubMed

Essebier, Alexandra; Lamprecht, Marnie; Piper, Michael; Bodén, Mikael

2017-12-01

Transcription factors regulate gene expression and play an essential role in development by maintaining proliferative states, driving cellular differentiation and determining cell fate. Transcription factors are capable of regulating multiple genes over potentially long distances making target gene identification challenging. Currently available experimental approaches to detect distal interactions have multiple weaknesses that have motivated the development of computational approaches. Although an improvement over experimental approaches, existing computational approaches are still limited in their application, with different weaknesses depending on the approach. Here, we review computational approaches with a focus on data dependency, cell type specificity and usability. With the aim of identifying transcription factor target genes, we apply available approaches to typical transcription factor experimental datasets. We show that approaches are not always capable of annotating all transcription factor binding sites; binding sites should be treated disparately; and a combination of approaches can increase the biological relevance of the set of genes identified as targets. Copyright © 2017 Elsevier Inc. All rights reserved.

Environmental factors controlling phytoplankton productivity and phenology in the Southern Ocean

NASA Astrophysics Data System (ADS)

Ardyna, M.; Claustre, H.; Sallee, J. B.; Gentili, B.; D'Ortenzio, F.

2016-02-01

The Southern Ocean (SO), highly sensitive to climate change, is currently experiencing a rapid warming and freshening. Such drastic hydrographical changes may significantly alter the SO's biological carbon pump (i.e., the efficiency of primary production and its transfers to higher trophic levels and/or sequestration to depth). However, before making any predictions, a better understanding of the biogeography and environmental factors controlling phytoplankton processes (i.e., productivity and phenology) in the Southern Ocean is clearly needed. We present here a bio-regionalization of the SO from satellite-derived observations, where a range of three orders of magnitude of productivity is observed. A clear latitudinal gradient in the bloom initiation was underpinned following the light regime, with some exception in well-mixed and sea-ice edge areas. Environmental factors controlling the phytoplankton phenology and productivity appear to be completely decoupled. Phytoplankton productivity in the SO is clearly associated to both shallow areas and front locations, where iron limitation seems to be less pronounced. These findings will give us a more comprehensive understanding in both space and time of the limiting factors of PP (i.e., nutrients, light-mixing regime…), which are of fundamental interest for identifying and explaining potential ongoing changes in SO's marine ecosystems.

Effects of microgravity on renal stone risk assessment

NASA Technical Reports Server (NTRS)

Pietrzyk, R. A.; Pak, C. Y. C.; Cintron, N. M.; Whitson, P. A.

1992-01-01

Physiologic changes induced during human exposure to the microgravity environment of space may contribute to an increased potential for renal stone formation. Renal stone risk factors obtained 10 days before flight and immediately after return to earth indicated that calcium oxalate and uric acid stone-forming potential was increased after space flights of 4-10 days. These data describe the need for examining renal stone risk during in-flight phases of space missions. Because of limited availability of space and refrigerated storage on spacecraft, effective methods must be developed for collecting urine samples in-flight and for preserving (or storing) them at temperatures and under conditions commensurate with mission constraints.

Analysis of the Δ(X) - L intervalley mixing in group-IV heterostructures

NASA Astrophysics Data System (ADS)

Kiselev, A. A.; Kim, K. W.; Yablonovitch, E.

2005-06-01

We provide a treatment of the problem of Δ(X) - L intervalley mixing in differently oriented SiGe heterostructures in the transparent effective mass method. Mixing potentials can be calculated, considering changes in the constituent Concentrations of individual heterolayers from some "virtual crystal level" as a bunch of microscopic single-ion perturbations. Strong mixing between lowest localized Δ and L states can be achieved in (113) structures, making them favorable for the electrically controlled gigantic intervalley g factor modulation. We provide estimates for the mixing potential and further consider limitations related to the strength of the in-plane localization and quality of the interface.

Distribution and transfer of potentially toxic metal(loid)s in Juncus effusus from the indigenous zinc smelting area, northwest region of Guizhou Province, China.

PubMed

Peng, Yishu; Chen, Jun; Wei, Huairui; Li, Shibin; Jin, Tao; Yang, Ruidong

2018-05-15

We collected samples (i.e., the aerial parts and roots of Juncus effusus and their growth media) in the indigenous zinc smelting area in the northwest region of Guizhou Province, China, and we measured and analyzed potentially toxic metal(loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb and zinc, Zn) in these samples. The results include the following: First, there is a high concentration of one or more potentially toxic metal(loid)s in the slag and surrounding soil in the research area. This situation might be caused by metal(loid) damage or contamination due to the circumstances. Additionally, Juncus effusus in the indigenous zinc smelting area are contaminated by some potentially toxic metal(loid)s; since they are used for Chinese medical materials, it is especially significant that their As, Cd and Pb concentrations are greater than their limited standard values. Finally, both the bioconcentration factors and transfer factors for most potentially toxic metal(loid)s in Juncus effusus are less than 1 in the study area. Therefore, we suggest that Juncus effusus could be used for phytostabilization or as a pioneer plant for phytoremediation of potentially toxic metal(loid)s because it has a tolerance and exclusion mechanism for these metal(loid)s in the research district. Copyright © 2018 Elsevier Inc. All rights reserved.

Potential for the use of mHealth in the management of cardiovascular disease in Kerala: a qualitative study.

PubMed

Smith, Rebecca; Menon, Jaideep; Rajeev, Jaya G; Feinberg, Leo; Kumar, Raman Krishan; Banerjee, Amitava

2015-11-17

To assess the potential for using mHealth in cardiovascular disease (CVD) management in Kerala by exploring: (1) experiences and challenges of current CVD management; (2) current mobile phone use; (3) expectations of and barriers to mobile phone use in CVD management. Qualitative, semistructured, individual interviews. 5 primary health centres in Ernakulam district, Kerala, India. 15 participants in total from 3 stakeholder groups: 5 patients with CVD and/or its risk factors, 5 physicians treating CVD and 5 Accredited Social Health Activists (ASHAs). Patients were sampled for maximum variation on the basis of age, sex, CVD diagnoses and risk factors. All participants had access to a mobile phone. The main themes identified relating to the current challenges of CVD were poor patient disease knowledge, difficulties in implementing primary prevention and poor patient lifestyles. Participants noted phone calls as the main function of current mobile phone use. The expectations of mHealth use are to: improve accessibility to healthcare knowledge; provide reminders of appointments, medication and lifestyle changes; save time, money and travel; and improve ASHA job efficacy. All perceived barriers to mHealth were noted within physician interviews. These included fears of mobile phones negatively affecting physicians' roles, the usability of mobile phones, radiation and the need for physical consultations. There are three main potential uses of mHealth in this population: (1) as an educational tool, to improve health education and lifestyle behaviours; (2) to optimise the use of limited resources, by overcoming geographical barriers and financial constraints; (3) to improve use of healthcare, by providing appointment and treatment reminders in order to improve disease prevention and management. Successful mHealth design, which takes barriers into account, may complement current practice and optimise use of limited resources. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Harvested area gaps in China between 1981 and 2010: effects of climatic and land management factors

NASA Astrophysics Data System (ADS)

Yu, Qiangyi; van Vliet, Jasper; Verburg, Peter H.; You, Liangzhi; Yang, Peng; Wu, Wenbin

2018-04-01

Previous analyses have shown that cropland in China is intensifying, leading to an increase in crop production. However, these output measures leave the potential for further intensification largely unassessed. This study uses the harvested area gap (HAG), which expresses the amount of harvested area that can be gained if all existing cropland is harvested as frequently as possible, according to their potential limit for multi-cropping. Specifically, we calculate the HAG and changes in the HAG in China between 1981 and 2010. We further assess how climatic and land management factors affect these changes. We find that in China the HAG decreases between the 1980s and the 1990s, and subsequently increases between the 1990s and the 2000s, resulting in a small net increase for the entire study period. The initial decrease in the HAG is the result of an increase in the average multi-cropping index throughout the country, which is larger than the increase in the potential multi-cropping index as a result of the changed climatic factors. The subsequent increase in the HAG is the result of a decrease in average multi-cropping index throughout the country, in combination with a stagnant potential. Despite the overall increase in harvested area in China, many regions, e.g. Northeast and Lower Yangtze, are characterized by an increased HAG, indicating their potential for further increasing the multi-cropping index. The study demonstrates the application of the HAG as a method to identify areas where the harvested area can increase to increase crop production, which is currently underexplored in scientific literature.

Littoral Combat Ship: Deployment of USS Freedom Revealed Risks in Implementing Operational Concepts and Uncertain Costs

DTIC Science & Technology

2014-07-01

ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for...such as systems reliability and crew sleep hours . However, several factors limited the operational lessons learned. For example, mechanical problems...concepts. In February 2010, we reported several potential risks in implementing the new operational concepts for the LCS. 4 In its report

Recent results from the Japanese X-ray astronomy satellites

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

Tanaka, Y.

1986-01-01

Observations of neutron stars and their environments, and the emission and absorption of iron, obtained with the Hakucho and Tenma satellites, are examined. The characteristics of X-ray bursts, neutron stars, and accretion disks, in particular spectra, color and effective temperatures, blackbody temperature and radius, the emissivity factor, and the Eddington limit luminosity, are discussed. Consideration is given to the rapid burster discovered by Lewin et al. (1976) and potential blackhole sources. 43 references.

Cardiovascular Disease Among Transgender Adults Receiving Hormone Therapy: A Narrative Review.

PubMed

Streed, Carl G; Harfouch, Omar; Marvel, Francoise; Blumenthal, Roger S; Martin, Seth S; Mukherjee, Monica

2017-08-15

Recent reports estimate that 0.6% of adults in the United States, or approximately 1.4 million persons, identify as transgender. Despite gains in rights and media attention, the reality is that transgender persons experience health disparities, and a dearth of research and evidence-based guidelines remains regarding their specific health needs. The lack of research to characterize cardiovascular disease (CVD) and CVD risk factors in transgender populations receiving cross-sex hormone therapy (CSHT) limits appropriate primary and specialty care. As with hormone therapy in cisgender persons (that is, those whose sex assigned at birth aligns with their gender identity), existing research in transgender populations suggests that CVD risk factors are altered by CSHT. Currently, systemic hormone replacement for cisgender adults requires a nuanced discussion based on baseline risk factors and age of administration of exogenous hormones because of concern regarding an increased risk for myocardial infarction and stroke. For transgender adults, CSHT has been associated with the potential for worsening CVD risk factors (such as blood pressure elevation, insulin resistance, and lipid derangements), although these changes have not been associated with increases in morbidity or mortality in transgender men receiving CSHT. For transgender women, CSHT has known thromboembolic risk, and lower-dose transdermal estrogen formulations are preferred over high-dose oral formulations. In addition, many studies of transgender adults focus predominantly on younger persons, limiting the generalizability of CSHT in older transgender adults. The lack of randomized controlled trials comparing various routes and formulations of CSHT, as well as the paucity of prospective cohort studies, limits knowledge of any associations between CSHT and CVD.

Reduced carbon sequestration potential of biochar in acidic soil.

PubMed

Sheng, Yaqi; Zhan, Yu; Zhu, Lizhong

2016-12-01

Biochar application in soil has been proposed as a promising method for carbon sequestration. While factors affecting its carbon sequestration potential have been widely investigated, the number of studies on the effect of soil pH is limited. To investigate the carbon sequestration potential of biochar across a series of soil pH levels, the total carbon emission, CO 2 release from inorganic carbon, and phospholipid fatty acids (PLFAs) of six soils with various pH levels were compared after the addition of straw biochar produced at different pyrolysis temperatures. The results show that the acidic soils released more CO 2 (1.5-3.5 times higher than the control) after the application of biochar compared with neutral and alkaline soils. The degradation of both native soil organic carbon (SOC) and biochar were accelerated. More inorganic CO 2 release in acidic soil contributed to the increased degradation of biochar. Higher proportion of gram-positive bacteria in acidic soil (25%-36%) was responsible for the enhanced biochar degradation and simultaneously co-metabolism of SOC. In addition, lower substrate limitation for bacteria, indicated by higher C-O stretching after the biochar application in the acidic soil, also caused more CO 2 release. In addition to the soil pH, other factors such as clay contents and experimental duration also affected the phsico-chemical and biotic processes of SOC dynamics. Gram-negative/gram-positive bacteria ratio was found to be negatively related to priming effects, and suggested to serve as an indicator for priming effect. In general, the carbon sequestration potential of rice-straw biochar in soil reduced along with the decrease of soil pH especially in a short-term. Given wide spread of acidic soils in China, carbon sequestration potential of biochar may be overestimated without taking into account the impact of soil pH. Copyright © 2016 Elsevier B.V. All rights reserved.

N-acetylcysteine does not influence the activity of endothelium-derived relaxing factor in vivo.

PubMed

Creager, M A; Roddy, M A; Boles, K; Stamler, J S

1997-02-01

Nitric oxide forms complexes with an array of biomolecular carriers that retain biological activity. This reactivity of nitric oxide in physiological systems has led to some dispute as to whether endothelium-derived relaxing factors nitric oxide or a closely related adduct thereof, such as a nitrosothiol. In vitro bioassays used to address this question are limited by the exclusion of biological thiols that are requisite for nitrosothiol formation. Thus, the purpose of this study was to obtain insight into the identity of endothelium-derived relaxing factor in vivo. We reasoned that if endothelium-derived relaxing factor in nitric oxide, infusion of physiological concentrations of thiol would potentiate its bioactivity by analogy with effects seen in vitro, whereas nitrosothiol would be resistant to such modulation. We used venous-occlusion plethysmography to study forearm blood flow in normal subjects. Methacholine (0.3 to 10 micrograms/min) and nitroglycerin (1 to 30 micrograms/min) were infused via the brachial artery to elicit endothelium-dependent and endothelium-independent vasodilation, respectively. Dose-response determinations were made for each drug before and after an intra-arterial infusion of the reduced thiol, N-acetylcysteine, at rates estimated to achieve a physiological concentration of 1 mmol/L. Methacholine increased forearm blood flow in a dose-dependent manner. Infusion of N-acetylcysteine did not change the sensitivity (ED50, 1.7 versus 1.7 micrograms/min, P = NS) or maximal response to methacholine. In contrast, thiol increased the sensitivity to nitroglycerin (ED50, 4.7 versus 2.8 micrograms/min, P < .01). Thus, conflicting with reports in vitro, thiol does not modulate endothelium-derived relaxing factor responses in vivo. These data indicate that sulfhydryl groups are not a limiting factor for endothelium-derived relaxing factor responses in forearm resistance vessels in normal humans and are in keeping with reports that nitrosothiol contributes to endothelium-derived relaxing factor bioactivity in plasma and vascular smooth muscle. Potentiation of the effects of nitroglycerin by N-acetylcysteine can be attributed to its enhanced biotransformation to an endothelium-derived relaxing factor equivalent, such as nitrosothiol. These observations support the notion of an equilibrium between nitric oxide and nitrosothiol in biological systems that may be influenced by redox state.

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices.

PubMed

Yang, Da; Jennings, Anna D; Borrego, Evalynn; Retterer, Scott T; Männik, Jaan

2018-01-01

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquid culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.

Androstenediol inhibits the trauma-hemorrhage-induced increase in caspase-3 by downregulating the inducible nitric oxide synthase pathway.

PubMed

Kiang, Juliann G; Peckham, Russell M; Duke, Leah E; Shimizu, Tomoharu; Chaudry, Irshad H; Tsokos, George C

2007-03-01

Soft tissue trauma and hemorrhage (T-H) diminishes various aspects of liver function, while it increases hepatic nitrate/nitrite, inducible nitric oxide synthase (iNOS), and endothelin-1 levels. Treatment with androstenediol (AED) inhibits the T-H-induced alterations of the above parameters. We sought to identify the molecular events underlying the beneficial effect of AED. Exposure of rats to T-H significantly increased the caspase-3 activity and protein, whereas treatment with AED significantly limited these increases. AED treatment also suppressed the T-H-induced increase in iNOS by effectively altering the levels of key transcription factors involved in the regulation of iNOS expression. Immunoprecipitation and immunoblotting analyses indicate that T-H increased apoptosome formation, and AED treatment significantly decreased it. Modulating the iNOS protein by transfecting cells with iNOS gene or small interfering RNA further confirmed the correlation between iNOS and caspase-3. Our data indicate that AED limits caspase-3 expression by suppressing the expression of transcription factors involved in the production of iNOS, resulting in decreased apoptosome. AED can potentially be a useful adjuvant for limiting liver apoptosis following T-H shock.

Understanding public responses to chemical, biological, radiological and nuclear incidents--driving factors, emerging themes and research gaps.

PubMed

Krieger, Kristian; Amlôt, Richard; Rogers, M Brooke

2014-11-01

This paper discusses the management of public responses to incidents involving chemical, biological, radiological and nuclear materials (CBRN). Given the extraordinary technical and operational challenges of a response to a CBRN release including, but not limited to, hazard detection and identification, casualty decontamination and multi-agency co-ordination, it is not surprising that public psychological and behavioural responses to such incidents have received limited attention by scholars and practitioners alike. As a result, a lack of understanding about the role of the public in effective emergency response constitutes a major gap in research and practice. This limitation must be addressed as a CBRN release has the potential to have wide-reaching psychological and behavioural impacts which, in turn, impact upon public morbidity and mortality rates. This paper addresses a number of key issues: why public responses matter; how responses have been conceptualised by practitioners; what factors have been identified as influencing public responses to a CBRN release and similar extreme events, and what further analysis is needed in order to generate a better understanding of public responses to inform the management of public responses to a CBRN release. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices

DOE PAGES

Yang, Da; Jennings, Anna D.; Borrego, Evalynn; ...

2018-05-01

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquidmore » culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Lastly, our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.« less

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices

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

Yang, Da; Jennings, Anna D.; Borrego, Evalynn

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquidmore » culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Lastly, our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.« less

Enhancing crop resilience to combined abiotic and biotic stress through the dissection of physiological and molecular crosstalk

PubMed Central

Kissoudis, Christos; van de Wiel, Clemens; Visser, Richard G. F.; van der Linden, Gerard

2014-01-01

Plants growing in their natural habitats are often challenged simultaneously by multiple stress factors, both abiotic and biotic. Research has so far been limited to responses to individual stresses, and understanding of adaptation to combinatorial stress is limited, but indicative of non-additive interactions. Omics data analysis and functional characterization of individual genes has revealed a convergence of signaling pathways for abiotic and biotic stress adaptation. Taking into account that most data originate from imposition of individual stress factors, this review summarizes these findings in a physiological context, following the pathogenesis timeline and highlighting potential differential interactions occurring between abiotic and biotic stress signaling across the different cellular compartments and at the whole plant level. Potential effects of abiotic stress on resistance components such as extracellular receptor proteins, R-genes and systemic acquired resistance will be elaborated, as well as crosstalk at the levels of hormone, reactive oxygen species, and redox signaling. Breeding targets and strategies are proposed focusing on either manipulation and deployment of individual common regulators such as transcription factors or pyramiding of non- (negatively) interacting components such as R-genes with abiotic stress resistance genes. We propose that dissection of broad spectrum stress tolerance conferred by priming chemicals may provide an insight on stress cross regulation and additional candidate genes for improving crop performance under combined stress. Validation of the proposed strategies in lab and field experiments is a first step toward the goal of achieving tolerance to combinatorial stress in crops. PMID:24904607

The mechanism of metal nanoparticle formation in plants: limits on accumulation

NASA Astrophysics Data System (ADS)

Haverkamp, R. G.; Marshall, A. T.

2009-08-01

Metal nanoparticles have many potential technological applications. Biological routes to the synthesis of these particles have been proposed including production by vascular plants, known as phytoextraction. While many studies have looked at metal uptake by plants, particularly with regard to phytoremediation and hyperaccumulation, few have distinguished between metal deposition and metal salt accumulation. This work describes the uptake of AgNO3, Na3Ag(S2O3)2, and Ag(NH3)2NO3 solutions by hydroponically grown Brassica juncea and the quantitative measurement of the conversion of these salts to silver metal nanoparticles. Using X-ray absorption near edge spectroscopy (XANES) to determine the metal speciation within the plants, combined with atomic absorption spectroscopy (AAS) for total Ag, the quantity of reduction of AgI to Ag0 is reported. Transmission electron microscopy (TEM) showed Ag particles of 2-35 nm. The factors controlling the amount of silver accumulated are revealed. It is found that there is a limit on the amount of metal nanoparticles that may be deposited, of about 0.35 wt.% Ag on a dry plant basis, and that higher levels of silver are obtained only by the concentration of metal salts within the plant, not by deposition of metal. The limit on metal nanoparticle accumulation, across a range of metals, is proposed to be controlled by the total reducing capacity of the plant for the reduction potential of the metal species and limited to reactions occurring at an electrochemical potential greater than 0 V (verses the standard hydrogen electrode).

14 CFR 25.1531 - Maneuvering flight load factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering flight load factors. 25.1531... Operating Limitations § 25.1531 Maneuvering flight load factors. Load factor limitations, not exceeding the positive limit load factors determined from the maneuvering diagram in § 25.333(b), must be established. ...

New Chimeric Antigen Receptor Design for Solid Tumors

PubMed Central

Wang, Yuedi; Luo, Feifei; Yang, Jiao; Zhao, Chujun; Chu, Yiwei

2017-01-01

In recent years, chimeric antigen receptor (CAR) T-cell therapy has become popular in immunotherapy, particularly after its tremendous success in the treatment of lineage-restricted hematologic cancers. However, the application of CAR T-cell therapy for solid tumors has not reached its full potential because of the lack of specific tumor antigens and inhibitory factors in suppressive tumor microenvironment (TME) (e.g., programmed death ligand-1, myeloid-derived suppressor cells, and transforming growth factor-β). In this review, we include some limitations in CAR design, such as tumor heterogeneity, indefinite spatial distance between CAR T-cell and its target cell, and suppressive TME. We also summarize some new approaches to overcome these hurdles, including targeting neoantigens and/or multiple antigens at once and depleting some inhibitory factors. PMID:29312360

New Insights into the Operating Voltage of Aqueous Supercapacitors.

PubMed

Yu, Minghao; Lu, Yongzhuang; Zheng, Haibing; Lu, Xihong

2018-03-12

The main limitation of aqueous supercapacitors (SCs) lies in their narrow operating voltages, especially when compared with organic SCs. Fundamental understanding of factors relevant to the operating voltage helps providing guidance for the assembly of high-voltage aqueous SCs. In this regard, this concept analyzes the deciding factors for the operating voltage of aqueous SCs. Strategies applied to expand the operating voltage are summarized and discussed from the aspects of electrolyte, electrode, and asymmetric structure. Dynamic factors associated with water electrolysis and maximally using the available potential ranges of electrodes are particularly emphasized. Finally, other promising approaches that have not been explored and their challenges are also elaborated, hoping to provide more insights for the design of high-voltage aqueous SCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluating a medical error taxonomy.

PubMed

Brixey, Juliana; Johnson, Todd R; Zhang, Jiajie

2002-01-01

Healthcare has been slow in using human factors principles to reduce medical errors. The Center for Devices and Radiological Health (CDRH) recognizes that a lack of attention to human factors during product development may lead to errors that have the potential for patient injury, or even death. In response to the need for reducing medication errors, the National Coordinating Council for Medication Errors Reporting and Prevention (NCC MERP) released the NCC MERP taxonomy that provides a standard language for reporting medication errors. This project maps the NCC MERP taxonomy of medication error to MedWatch medical errors involving infusion pumps. Of particular interest are human factors associated with medical device errors. The NCC MERP taxonomy of medication errors is limited in mapping information from MEDWATCH because of the focus on the medical device and the format of reporting.

Functional limitations as potential mediators of the effects of self-reported vision status on fall risk of older adults.

PubMed

Steinman, Bernard A; Allen, Susan M; Chen, Jie; Pynoos, Jon

2015-02-01

To test whether limitations in mobility and large-muscle functioning mediate self-reported vision status to increase fall risk among respondents age 65 and above. This study used two waves from the Health and Retirement Study. We conducted binary logistic and negative binomial regression analyses to test indirect paths leading from self-reported vision status to falls, via indices of mobility and large-muscle functioning. Limited evidence was found for a mediating effect among women; however, large-muscle groups were implicated as partially mediating risk factors for falls among men with fair self-reported vision status. Implications of these findings are discussed including the need for prioritizing improved muscle strength of older men and women with poor vision as a preventive measure against falls. © The Author(s) 2014.

The impact of race on metabolic disease risk factors in women with and without posttraumatic stress disorder.

PubMed

Dedert, Eric A; Harper, Leia A; Calhoun, Patrick S; Dennis, Michelle F; Beckham, Jean C

2013-03-01

The literature on PTSD and metabolic disease risk factors has been limited by lacking investigation of the potential influence of commonly comorbid disorders and the role of race. In this study data were provided by a sample of 134 women (63 PTSD and 71 without PTSD). Separate sets of models examining associations of psychiatric disorder classifications with metabolic disease risk factors were used. Each model included race (African American or Caucasian), psychiatric disorder, and their interaction. There was an interaction of race and PTSD on body mass index, abdominal obesity, and triglycerides. While PTSD was not generally associated with deleterious health effects in African American participants, PTSD was related to worse metabolic disease risk factors in Caucasians. MDD was associated with metabolic disease risk factors, but there were no interactions with race. Results support the importance of race in the relationship between PTSD and metabolic disease risk factors. Future research would benefit from analysis of cultural factors to explain how race might influence metabolic disease risk factors in PTSD.

Finding Uncertainties that Cause the Age Dependence of Dose Limits to Be Immature

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.

2007-01-01

Space radiation permissible exposure limits (PEL) are intended to set acceptable levels of cancer risks, and avoid any clinical significant non-cancer effects. The 1989 recommendation of the National Council of Radiation Protection and Measurements (NCRP) recommended a strong age dependence of dose limits that departed drastically from the then mature 1970 dose limits recommendations from the National Academy of Science, which were independent of age. In 2000, the NCRP recommended revised limits that showed a similar trend of risk with age to the 1989 report. In this model, the cancer risk per Sv varies by more than 2-fold for ages between 30- and 50-yr. Therefore for galactic cosmic rays exposure, astronaut age has a larger influence on risk then radiation shielding mass or material composition, vehicle propulsion method, or position in the solar cycle. For considering the control of mission costs and resources, the possibility of using astronaut age as a trade variable in mission design could be considered. However, the uncertainties in describing the age dependence on risk have not been fully explored. We discuss biological factors that influence the age dependence of radiation risks, including susceptibility, expression and latency, and radiation quality. These factors depend not only on the individual s age, but also their genetic sensitivity and interaction with other environmental factors. Epidemiological data is limited in describing the age dependence on risk. The 2005, BEIR VII report recommends an age dependence for cancer risk attributable solely to the life-table disagreeing strongly with the NCRP model. However, BEIR VII also noted the limited power of human data for concomitantly describing both age and age after exposure dependences of cancer risks. Many experimental studies have shown that high LET radiation (e.g., high charge and energy (HZE) nuclei and neutrons) display reduced latency compared to low LET radiation, suggesting distinct biological factors are important. We discuss potential molecular mechanisms that would influence the age dependence of radiation risks. A probability distribution function for the uncertainties in age-dependence of risk models is described and predictions for Mars missions discussed. Our report suggests that theoretical considerations based on new experimental studies are needed to ensure the correct age dependence in space radiation risk models and the resulting Astronaut PEL.

Integrated Approach of Agri-nanotechnology: Challenges and Future Trends

PubMed Central

Mishra, Sandhya; Keswani, Chetan; Abhilash, P. C.; Fraceto, Leonardo F.; Singh, Harikesh Bahadur

2017-01-01

Nanotechnology representing a new frontier in modern agriculture is anticipated to become a major thrust in near future by offering potential applications. This integrating approach, i.e., agri-nanotechnology has great potential to cope with global challenges of food production/security, sustainability and climate change. However, despite the potential benefits of nanotechnology in agriculture so far, their relevance has not reached up to the field conditions. The elevating concerns about fate, transport, bioavailability, nanoparticles toxicity and inappropriateness of regulatory framework limit the complete acceptance and inclination to adopt nanotechnologies in agricultural sector. Moreover, the current research trends lack realistic approach that fail to attain comprehensive knowledge of risk assessment factors and further toxicity of nanoparticles toward agroecosystem components viz. plant, soil, soil microbiomes after their release into the environment. Hence in the present review we attempt to suggest certain key points to be addressed in the current and future agri-nanotechnology researches on the basis of recognized knowledge gaps with strong recommendation of incorporating biosynthesized nanoparticles to carry out analogous functions. In this perspective, the major points are as follows: (i) Mitigating risk assessment factors (responsible for fate, transport, behavior, bioavailability and toxicity) for alleviating the subsequent toxicity of nanoparticles. (ii) Optimizing permissible level of nanoparticles dose within the safety limits by performing dose dependent studies. (iii) Adopting realistic approach by designing the experiments in natural habitat and avoiding in vitro assays for accurate interpretation. (iv) Most importantly, translating environmental friendly and non-toxic biosynthesized nanoparticles from laboratory to field conditions for agricultural benefits. PMID:28421100

Developing integrated benchmarks for DOE performance measurement

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

Barancik, J.I.; Kramer, C.F.; Thode, Jr. H.C.

1992-09-30

The objectives of this task were to describe and evaluate selected existing sources of information on occupational safety and health with emphasis on hazard and exposure assessment, abatement, training, reporting, and control identifying for exposure and outcome in preparation for developing DOE performance benchmarks. Existing resources and methodologies were assessed for their potential use as practical performance benchmarks. Strengths and limitations of current data resources were identified. Guidelines were outlined for developing new or improved performance factors, which then could become the basis for selecting performance benchmarks. Data bases for non-DOE comparison populations were identified so that DOE performance couldmore » be assessed relative to non-DOE occupational and industrial groups. Systems approaches were described which can be used to link hazards and exposure, event occurrence, and adverse outcome factors, as needed to generate valid, reliable, and predictive performance benchmarks. Data bases were identified which contain information relevant to one or more performance assessment categories . A list of 72 potential performance benchmarks was prepared to illustrate the kinds of information that can be produced through a benchmark development program. Current information resources which may be used to develop potential performance benchmarks are limited. There is need to develop an occupational safety and health information and data system in DOE, which is capable of incorporating demonstrated and documented performance benchmarks prior to, or concurrent with the development of hardware and software. A key to the success of this systems approach is rigorous development and demonstration of performance benchmark equivalents to users of such data before system hardware and software commitments are institutionalized.« less

Alternative Level of Care: Canada's Hospital Beds, the Evidence and Options

PubMed Central

Sutherland, Jason M.; Crump, R. Trafford

2013-01-01

Patients designated as alternative level of care (ALC) are an ongoing concern for healthcare policy makers across Canada. These patients occupy valuable hospital beds and limit access to acute care services. The objective of this paper is to present policy alternatives to address underlying factors associated with ALC bed use. Three alternatives, and their respective limitations and structural challenges, are discussed. Potential solutions may require a mix of policy options proposed here. Inadequate policy jeopardizes new acute care activity-based funding schemes in British Columbia and Ontario. Failure to address this issue could exacerbate pressures on the existing bottlenecks in the community care system in these and other provinces. PMID:23968671

Gene Therapy for the Treatment of Diabetic Neuropathy

PubMed Central

Mata, Marina; Chattopadhyay, Munmun; Fink, David J

2009-01-01

Neuropathy is a common, untreatable complication of both type 1 and type 2 diabetes. In animal models peptide neurotrophic factors can be used to protect against the development of neuropathy, but the combination of short half-life and off-target effects of these potent pleiotropic peptides has limited translation to human therapy. Gene transfer is a promising strategy that might circumvent these limitations. In this essay we review the basic methods of gene transfer and the preclinical data in rodent models that support the utility of this approach in the treatment of diabetic neuropathy. The path to a clinical applications and potential pitfalls in developing gene therapy for the treatment of diabetic neuropathy are considered. PMID:18990298

The Private Market for Long-Term Care Insurance in the U.S.: A Review of the Evidence

PubMed Central

Brown, Jeffrey R.; Finkelstein, Amy

2009-01-01

This paper reviews the growing literature on the market for private long-term care insurance, a market notable for its small size despite the fact that long-term care expenses are potentially large and highly uncertain. After summarizing long-term care utilization and insurance coverage in the United States, the paper reviews research on the supply of and the demand for private long-term care insurance. It concludes that demand-side factors impose important limits on the size of the private market and that we currently have a limited understanding of how public policies could be designed to encourage the growth of this market. PMID:20046809

Smartphone applications: potential tools for use in preparing for CCRN certification examinations.

PubMed

Curran, Claire

2014-06-01

Recent advances in smartphone technology now allow clinicians to use commercially produced applications when studying for nursing certification examinations. The quality of currently available CCRN review applications varies in this first generation of products. Most are limited to multiple-choice practice questions, although a few have additional elements such as study guides and reference charts. Weaknesses found in the applications evaluated include poorly written and edited content, questions limited to rote memorization rather than application and analysis of knowledge, and content too basic or outside the scope of experienced critical care nursing practice. A list of important factors for consumers to consider before purchase is provided. ©2014 American Association of Critical-Care Nurses.

Accounting for Ethnicity-Related Differences in Ocular Surface Integrity as a Step Toward Understanding Contact Lens Discomfort.

PubMed

Chan, Stefanie M; Svitova, Tatyana F; Lin, Meng C

2017-01-01

Contact lens discomfort is a common problem that can lead to unsuccessful or limited contact lens wear. Although many factors may contribute to contact lens discomfort, limited research has explored the influence of ethnicity-related differences in the anatomy and physiology of the ocular surface. Therefore, we performed a search of the literature in PubMed using key words related to "ocular surface" paired with the terms "race" and "ethnicity." The goal of this review was to determine potential areas of research regarding ethnicity differences, particularly between Asian and non-Asian eyes, in ocular surface integrity to advance our understanding of contact lens discomfort.

Plants from the abandoned Nacozari mine tailings: evaluation of their phytostabilization potential.

PubMed

Santos, Alina E; Cruz-Ortega, Rocio; Meza-Figueroa, Diana; Romero, Francisco M; Sanchez-Escalante, Jose Jesus; Maier, Raina M; Neilson, Julia W; Alcaraz, Luis David; Molina Freaner, Francisco E

2017-01-01

Phytostabilization is a remediation technology that uses plants for in-situ stabilization of contamination in soils and mine tailings. The objective of this study was to identify native plant species with potential for phytostabilization of the abandoned mine tailings in Nacozari, Sonora in northern Mexico. A flora of 42 species in 16 families of angiosperms was recorded on the tailings site and the abundance of the most common perennial species was estimated. Four of the five abundant perennial species showed evidence of regeneration: the ability to reproduce and establish new seedlings. A comparison of selected physicochemical properties of the tailings in vegetated patches with adjacent barren areas suggests that pH, electrical conductivity, texture, and concentration of potentially toxic elements do not limit plant distribution. For the most abundant species, the accumulation factor for most metals was <1, with the exception of Zn in two species. A short-term experiment on adaptation revealed limited evidence for the formation of local ecotypes in Prosopis velutina and Amaranthus watsonii . Overall, the results of this study indicate that five native plant species might have potential for phytostabilization of the Nacozari tailings and that seed could be collected locally to revegetate the site. More broadly, this study provides a methodology that can be used to identify native plants and evaluate their phytostabilization potential for similar mine tailings.

Plants from the abandoned Nacozari mine tailings: evaluation of their phytostabilization potential

PubMed Central

Santos, Alina E.; Cruz-Ortega, Rocio; Meza-Figueroa, Diana; Romero, Francisco M.; Sanchez-Escalante, Jose Jesus; Maier, Raina M.; Neilson, Julia W.; Alcaraz, Luis David

2017-01-01

Phytostabilization is a remediation technology that uses plants for in-situ stabilization of contamination in soils and mine tailings. The objective of this study was to identify native plant species with potential for phytostabilization of the abandoned mine tailings in Nacozari, Sonora in northern Mexico. A flora of 42 species in 16 families of angiosperms was recorded on the tailings site and the abundance of the most common perennial species was estimated. Four of the five abundant perennial species showed evidence of regeneration: the ability to reproduce and establish new seedlings. A comparison of selected physicochemical properties of the tailings in vegetated patches with adjacent barren areas suggests that pH, electrical conductivity, texture, and concentration of potentially toxic elements do not limit plant distribution. For the most abundant species, the accumulation factor for most metals was <1, with the exception of Zn in two species. A short-term experiment on adaptation revealed limited evidence for the formation of local ecotypes in Prosopis velutina and Amaranthus watsonii. Overall, the results of this study indicate that five native plant species might have potential for phytostabilization of the Nacozari tailings and that seed could be collected locally to revegetate the site. More broadly, this study provides a methodology that can be used to identify native plants and evaluate their phytostabilization potential for similar mine tailings. PMID:28484675

Indigenous soil bacteria and low moisture may limit but allow faecal bacteria to multiply and become a minor population in tropical soils

USGS Publications Warehouse

Byappanahalli, M.; Fujioka, R.

2004-01-01

The soil environment in Hawaii is generally characterised as sub-optimal but permissive to support the in situ growth of E. coli and enterococci. However, soil desiccation and competition for nutrients by major indigenous soil microflora have been identified as potential factors that could limit a rapid and continual growth of faecal indicator bacteria in this soil environment. Despite these limitations, the genetic capacities of E. coli and enterococci are robust enough to enable these bacteria to become established as minor populations of Hawaii's soil microflora. Although the concentrations of E. coli and enterococci may have represented a fraction of the total soil microbiota, their presence in this habitat was very significant, for two important reasons: (a) soil was a major environmental source of E. coli and enterococci, and (b) the elevated counts of these bacteria in streams that routinely exceeded the EPA standards were due to run-off from soil. As a result, E. coli and enterococci were inadequate indicators to measure the degree of faecal contamination and potential presence of sewage-borne pathogens in Hawaiian streams. ?? IWA Publishing 2004.

Patient clusters in acute, work-related back pain based on patterns of disability risk factors.

PubMed

Shaw, William S; Pransky, Glenn; Patterson, William; Linton, Steven J; Winters, Thomas

2007-02-01

To identify subgroups of patients with work-related back pain based on disability risk factors. Patients with work-related back pain (N = 528) completed a 16-item questionnaire of potential disability risk factors before their initial medical evaluation. Outcomes of pain, functional limitation, and work disability were assessed 1 and 3 months later. A K-Means cluster analysis of 5 disability risk factors (pain, depressed mood, fear avoidant beliefs, work inflexibility, and poor expectations for recovery) resulted in 4 sub-groups: low risk (n = 182); emotional distress (n = 103); severe pain/fear avoidant (n = 102); and concerns about job accommodation (n = 141). Pain and disability outcomes at follow-up were superior in the low-risk group and poorest in the severe pain/fear avoidant group. Patients with acute back pain can be discriminated into subgroups depending on whether disability is related to pain beliefs, emotional distress, or workplace concerns.

Elemental analysis of mussels and possible health risks arising from their consumption as a food: The case of Boka Kotorska Bay, Adriatic Sea.

PubMed

Tanaskovski, Bojan; Jović, Mihajlo; Mandić, Milica; Pezo, Lato; Degetto, Sandro; Stanković, Slavka

2016-08-01

The present study investigated the essential and non-essential elements in cultivated and wild mussels and assessed the health risk arising from their consumption as an impact of rapid growth and intensive production of Mytilus galloprovincialis in the mussel farms of the Boka Kotorska Bay. The concentrations of macro, micro, nonessential and even the small amounts of potentially toxic elements in the cultivated and wild mussels were influenced by industry, tourism and the geohydrology of the Bay. In the case of cultivated mussels, the limiting factor, i.e., the element the elevated concentration of which restricts mussels consumption, was Zr, while in the case of wild mussels the limiting factors were Cr and As. The sites with cultivated mussels stand out as sites with the highest calculated element pollution index, the total hazard index and with higher estimated risk to the health of consumers. Copyright © 2016 Elsevier Inc. All rights reserved.

Engineering allostery.

PubMed

Raman, Srivatsan; Taylor, Noah; Genuth, Naomi; Fields, Stanley; Church, George M

2014-12-01

Allosteric proteins have great potential in synthetic biology, but our limited understanding of the molecular underpinnings of allostery has hindered the development of designer molecules, including transcription factors with new DNA-binding or ligand-binding specificities that respond appropriately to inducers. Such allosteric proteins could function as novel switches in complex circuits, metabolite sensors, or as orthogonal regulators for independent, inducible control of multiple genes. Advances in DNA synthesis and next-generation sequencing technologies have enabled the assessment of millions of mutants in a single experiment, providing new opportunities to study allostery. Using the classic LacI protein as an example, we describe a genetic selection system using a bidirectional reporter to capture mutants in both allosteric states, allowing the positions most crucial for allostery to be identified. This approach is not limited to bacterial transcription factors, and could reveal new mechanistic insights and facilitate engineering of other major classes of allosteric proteins such as nuclear receptors, two-component systems, G protein-coupled receptors, and protein kinases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lower lethal temperatures for nonnative freshwater fishes in Everglades National Park, Florida

USGS Publications Warehouse

Schofield, Pam; Kline, Jeffrey L.

2018-01-01

Temperature is an important factor that shapes biogeography and species composition. In southern Florida, the tolerance of nonnative freshwater fishes to low temperatures is a critical factor in delineating their geographic spread. In this study, we provide empirical information on experimentally derived low-temperature tolerance limits of Banded Cichlid Heros severus and Spotfin Spiny Eel Macrognathus siamensis, two nonnative Everglades fishes that were lacking data, and African Jewelfish Hemichromis letourneuxi and Mayan Cichlid Cichlasoma urophthalmus, species for which previous results were derived from studies with small sample sizes. We also provide a literature review summarizing the current state of knowledge of low-temperature tolerances for all 17 nonnative freshwater fishes that have been found in Everglades National Park. Mean lower lethal temperature tolerances ranged from 4°C (Orinoco Sailfin Catfish Pterygoplichthys multiradiatus) to 16.1°C (Butterfly Peacock Bass Cichla ocellaris). These low-temperature limits may inform the understanding of the ecological role or influence of nonnative fishes and may lead to potential management opportunities and applications.

CO2-vegetation feedbacks and other climate changes implicated in reducing base flow

NASA Astrophysics Data System (ADS)

Trancoso, Ralph; Larsen, Joshua R.; McVicar, Tim R.; Phinn, Stuart R.; McAlpine, Clive A.

2017-03-01

Changes in the hydrological cycle have a significant impact in water limited environments. Globally, some of these regions are experiencing declining precipitation yet are simultaneously becoming greener, partly due to vegetation feedbacks associated with increasing atmospheric CO2 concentrations. Reduced precipitation together with increasing rates of actual evapotranspiration diminishes streamflow, especially base flow, a critical freshwater dry-season resource. Here we assess recent changes in base flow in Australia from 1981-2013 and 1950-2013 and separate the contribution of precipitation, potential evapotranspiration, and other factors on base flow trends. Our findings reveal that these other factors influencing the base flow trends are best explained by an increase in photosynthetic activity. These results provide the first robust observational evidence that increasing atmospheric CO2 and its associated vegetation feedbacks are reducing base flow in addition to other climatic impacts. These findings have broad implications for water resource management, especially in the world's water limited regions.

Engineering allostery

DOE PAGES

Raman, Srivatsan; Taylor, Noah; Genuth, Naomi; ...

2014-10-08

Allosteric proteins have great potential in synthetic biology, but our limited understanding of the molecular underpinnings of allostery has hindered the development of designer molecules, including transcription factors with new DNA-binding or ligand-binding specificities that respond appropriately to inducers. Such allosteric proteins could function as novel switches in complex circuits, metabolite sensors, or as orthogonal regulators for independent, inducible control of multiple genes. Advances in DNA synthesis and next-generation sequencing technologies have enabled the assessment of millions of mutants in a single experiment, providing new opportunities to study allostery. Using the classic LacI protein as an example, in this papermore » we describe a genetic selection system using a bidirectional reporter to capture mutants in both allosteric states, allowing the positions most crucial for allostery to be identified. Finally, this approach is not limited to bacterial transcription factors, and could reveal new mechanistic insights and facilitate engineering of other major classes of allosteric proteins such as nuclear receptors, two-component systems, G protein-coupled receptors, and protein kinases.« less

[Limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou].

PubMed

Lin, Wen-Jie; Xiao, Tang-Fu; Ao, Zi-Qiang; Xing, Jun; Ma, Huan-Cheng; Hu, Ting-Xing

2007-03-01

With indigenous zinc smelting waste residue, contaminated soil and background soil as test substrates, a pot experiment was conducted to study the growth characteristics of Lolium perenne and Trifolium pretense on these substrates. The results showed that the major limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou were the salt-alkali stress and the lower contents of organic matter, total N, available N and total K. The heavy metals in waste residue had a high concentration, but their available forms only occupied a small proportion, with low toxicity to plant but having potential harmful risk. Contaminated soil had lower concentrations of heavy metals than waste residue, but its contained heavy metals were more in available form. The constraints of revegetation on contaminated soil were the toxicity of heavy metals and the low contents of available P and K. Mixing contaminated soil with zinc smelting waste residue could be one of the effective approaches for the substrate amendment in indigenous zinc smelting areas.

Addressing uncertainty in modelling cumulative impacts within maritime spatial planning in the Adriatic and Ionian region.

PubMed

Gissi, Elena; Menegon, Stefano; Sarretta, Alessandro; Appiotti, Federica; Maragno, Denis; Vianello, Andrea; Depellegrin, Daniel; Venier, Chiara; Barbanti, Andrea

2017-01-01

Maritime spatial planning (MSP) is envisaged as a tool to apply an ecosystem-based approach to the marine and coastal realms, aiming at ensuring that the collective pressure of human activities is kept within acceptable limits. Cumulative impacts (CI) assessment can support science-based MSP, in order to understand the existing and potential impacts of human uses on the marine environment. A CI assessment includes several sources of uncertainty that can hinder the correct interpretation of its results if not explicitly incorporated in the decision-making process. This study proposes a three-level methodology to perform a general uncertainty analysis integrated with the CI assessment for MSP, applied to the Adriatic and Ionian Region (AIR). We describe the nature and level of uncertainty with the help of expert judgement and elicitation to include all of the possible sources of uncertainty related to the CI model with assumptions and gaps related to the case-based MSP process in the AIR. Next, we use the results to tailor the global uncertainty analysis to spatially describe the uncertainty distribution and variations of the CI scores dependent on the CI model factors. The results show the variability of the uncertainty in the AIR, with only limited portions robustly identified as the most or the least impacted areas under multiple model factors hypothesis. The results are discussed for the level and type of reliable information and insights they provide to decision-making. The most significant uncertainty factors are identified to facilitate the adaptive MSP process and to establish research priorities to fill knowledge gaps for subsequent planning cycles. The method aims to depict the potential CI effects, as well as the extent and spatial variation of the data and scientific uncertainty; therefore, this method constitutes a suitable tool to inform the potential establishment of the precautionary principle in MSP.

Computer-Assisted Optimization of Electrodeposited Hydroxyapatite Coating Parameters on Medical Alloys

NASA Astrophysics Data System (ADS)

Coşkun, M. İbrahim; Karahan, İsmail H.; Yücel, Yasin; Golden, Teresa D.

2016-04-01

CoCrMo bio-metallic alloys were coated with a hydroxyapatite (HA) film by electrodeposition using various electrochemical parameters. Response surface methodology and central composite design were used to optimize deposition parameters such as electrolyte pH, deposition potential, and deposition time. The effects of the coating parameters were evaluated within the limits of solution pH (3.66 to 5.34), deposition potential (-1.13 to -1.97 V), and deposition time (6.36 to 73.64 minutes). A 5-level-3-factor experimental plan was used to determine ideal deposition parameters. Optimum conditions for the deposition parameters of the HA coating with high in vitro corrosion performance were determined as electrolyte pH of 5.00, deposition potential of -1.8 V, and deposition time of 20 minutes.

A Systematic Review of Social Factors and Suicidal Behavior in Older Adulthood

PubMed Central

Fässberg, Madeleine Mellqvist; van Orden, Kimberly A.; Duberstein, Paul; Erlangsen, Annette; Lapierre, Sylvie; Bodner, Ehud; Canetto, Silvia Sara; Leo, Diego De; Szanto, Katalin; Waern, Margda

2012-01-01

Suicide in later life is a global public health problem. The aim of this review was to conduct a systematic analysis of studies with comparison groups that examined the associations between social factors and suicidal behavior (including ideation, non-fatal suicidal behavior, or deaths) among individuals aged 65 and older. Our search identified only 16 articles (across 14 independent samples) that met inclusion criteria. The limited number of studies points to the need for further research. Included studies were conducted in Canada (n = 2), Germany (n = 1), Hong Kong (n = 1), Japan (n = 1), Singapore (n = 1), Sweden (n = 2), Taiwan (n = 1), the U.K. (n = 2), and the U.S. (n = 3). The majority of the social factors examined in this review can be conceptualized as indices of positive social connectedness—the degree of positive involvement with family, friends, and social groups. Findings indicated that at least in industrialized countries, limited social connectedness is associated with suicidal ideation, non-fatal suicidal behavior, and suicide in later life. Primary prevention programs designed to enhance social connections as well as a sense of community could potentially decrease suicide risk, especially among men. PMID:22690159

Modifiable Midlife Risk Factors for Late-Life Cognitive Impairment and Dementia

PubMed Central

Hughes, Tiffany F.; Ganguli, Mary

2009-01-01

The baby boom generation is approaching the age of greatest risk for cognitive impairment and dementia. There is growing interest in strategies to modify the environment in midlife to increase the probability of maintaining cognitive health in late life. Several potentially modifiable risk factors have been studied in relation to cognitive impairment and dementia in late life, but methodological limitations of observational research have resulted in some inconsistencies across studies. The most promising strategies are maintaining cardiovascular health, engagement in mental, physical, and social activities, using alcohol in moderation, abstaining from tobacco use, and following a heart-healthy diet. Other factors that may influence cognitive health are occupational attainment, depression, personality, exposure to general anesthesia, head injury, postmenopausal hormone therapy, non-steroidal anti-inflammatory medications, and nutritional supplements such as antioxidants. Some long-term observational studies initiated in midlife or earlier, and some randomized controlled trials, have examined the effects of specific cognitive health promotion behaviors in midlife on the risk of cognitive impairment in late life. Overall, these studies provide limited support for risk reduction at this time. Recommendations and challenges for developing effective strategies to reduce the burden of cognitive impairment and dementia in the future are discussed. PMID:19946443

Understanding Early Contextual and Parental Risk Factors for the Development of Limited Prosocial Emotions.

PubMed

Waller, Rebecca; Shaw, Daniel S; Forbes, Erika E; Hyde, Luke W

2015-08-01

A growing body of evidence suggests that parenting influences the development of youth callous unemotional (CU) behavior. However, less is known about the effects of parenting or contextual risk factors on 'limited prosocial emotions' (LPE), a recent conceptualization of CU behavior added to the DSM-5. We focused on LPE at ages 10-12 and age 20 among low income, urban males (N = 310), and examined potential developmental precursors, including contextual risk factors assessed during infancy and observed maternal warmth during the toddler period. We found unique direct associations between maternal warmth, maternal aggression, and low empathetic awareness on LPE at ages 10-12, controlling for concurrent self-reported antisocial behavior. Further, there were indirect effects of maternal aggression, low empathetic awareness, and difficult infant temperament assessed in infancy on LPE at ages 10-12 via their influence on maternal warmth at age 2. Finally, there were lasting indirect effects of parental warmth on LPE at age 20, via LPE at ages 10-12. We discuss the implications of these findings for ecological models of antisocial behavior and LPE development, and preventative interventions that target the broader early parenting environment.

Understanding early contextual and parental risk factors for the development of limited prosocial emotions

PubMed Central

Waller, Rebecca; Shaw, Daniel S.; Forbes, Erika E.; Hyde, Luke W.

2014-01-01

A growing body of evidence suggests that parenting influences the development of youth callous unemotional (CU) behavior. However, less is known about the effects of parenting or contextual risk factors on ‘limited prosocial emotions’ (LPE), a recent conceptualization of CU behavior added to the DSM-5. We focused on LPE at ages 10–12 and age 20 among low income, urban males (N = 310), and examined potential developmental precursors, including contextual risk factors assessed during infancy and observed maternal warmth during the toddler period. We found unique direct associations between maternal warmth, maternal aggression, and low empathetic awareness on LPE at ages 10–12, controlling for concurrent self-reported antisocial behavior. Further, there were indirect effects of maternal aggression, low empathetic awareness, and difficult infant temperament assessed in infancy on LPE at ages 10–12 via their influence on maternal warmth at age 2. Finally, there were lasting indirect effects of parental warmth on LPE at age 20, via LPE at ages 10–12. We discuss the implications of these findings for ecological models of antisocial behavior and LPE development, and preventative interventions that target the broader early parenting environment. PMID:25510355

Clinical significance of achieving a flexion limitation with a tension band system in grade 1 degenerative spondylolisthesis: a minimum 5-year follow-up.

PubMed

Lee, Sang-Ho; Lee, Ho-Yeon; Baek, Oon Ki; Bae, Jun Seok; Yoo, Seung-Hwa; Lee, June-Ho

2015-03-15

Retrospective clinical study. To evaluate the effect of the limitation of flexion rotation clinically and radiologically after interspinous soft stabilization using a tension band system in grade 1 degenerative spondylolisthesis. Although several studies have been published on the clinical effects of limiting rotatory motion using tension band systems, which mainly targets the limitation of flexion rather than that of extension, they were confined to the category of pedicle screw-based systems, revealing inconsistent long-term outcomes. Sixty-one patients with a mean age of 60.6 years (range, 28-76 yr) who underwent interspinous soft stabilization after decompression for grade 1 degenerative spondylolisthesis with stenosis between 2002 and 2004 were analyzed. At follow-up, the patients were divided into 2 groups on the basis of their achievement or failure to achieve flexion limitation. The clinical and radiological findings were analyzed. A multiple linear regression analysis was performed to determine the prognostic factors for surgical outcomes. At a mean follow-up duration of 72.5 months (range, 61-82 mo), 51 patients were classified into the flexion-limited group and 10 into the flexion-unlimited group. Statistically significant improvements were noted only in the flexion-limited group in all clinical scores. In the flexion-unlimited group, there were significant deteriorations in flexion angle (P = 0.009), axial thickness of the ligamentum flavum (P = 0.013), and the foraminal cross-sectional area (P = 0.011), resulting in significant intergroup differences. The preoperative extension angle was identified as the most influential variable for the flexion limitation and the clinical outcomes. The effects of the limitation of flexion rotation achieved through interspinous soft stabilization using a tension band system after decompression were related to the prevention of late recurrent stenosis and resultant radicular pain caused by flexion instability. The extension potential at the index level was recognized as a major prognostic factor that can predict the flexion limitation and the clinical results. 4.

Comparison of interpretation methods of thermocouple psychrometer readouts

NASA Astrophysics Data System (ADS)

Guz, Łukasz; Majerek, Dariusz; Sobczuk, Henryk; Guz, Ewa; Połednik, Bernard

2017-07-01

Thermocouple psychrometers allow to determine the water potential, which can be easily recalculated into relative humidity of air in cavity of porous materials. The available typical measuring range of probe is very narrow. The lower limit of water potential measurements is about -200 kPa. On the other hand, the upper limit is approximately equal to -7000 kPa and depends on many factors. These paper presents a comparison of two interpretation methods of thermocouple microvolt output regarding: i) amplitude of voltage during wet-bulb temperature depression, ii) field under microvolt output curve. Previous results of experiments indicate that there is a robust correlation between water potential and field under microvolt output curve. In order to obtain correct results of water potential, each probe should be calibrated. The range of NaCl salt solutions with molality from 0.75M to 2.25M was used for calibration, which enable to obtain the osmotic potential from -3377 kPa to -10865 kPa. During measurements was applied 5mA heating current over a span 5 s and 5 mA cooling current aver a span 30s. The conducted study proves that using only different interpretation method based on field under microvolt output it is possible to achieve about 1000 kPa wider range of water potential. The average relative mean square error (RMSE) of this interpretation method is 1199 kPa while voltage amplitude based method yields average RMSE equaling 1378 kPa during calibration in temperature not stabilized conditions.

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

Malek, Ali; Balawender, Robert, E-mail: rbalawender@ichf.edu.pl

The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not themore » second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor.« less

Toxicological safeguards in the manned Mars missions

NASA Technical Reports Server (NTRS)

Coleman, Martin E.

1986-01-01

Safeguards against toxic chemical exposures during manned Mars missions (MMMs) will be important for the maintenance of crew health and the accomplishment of mission objectives. Potential sources include offgassing, thermodegradation or combustion of materials, metabolic products of crew members, and escape of chemical from containment. Spacecraft maximum allowable concentration (SMAC) limits will have to be established for potential contaminants during the MMMs. The following factors will be used in establishing these limits: duration of mission, simultaneous exposure to other contaminants, deconditioning of crew members after long periods of reduced gravity, and simultaneous exposure to ionizing radiation. Atmospheric contaminant levels in all compartments of the transit spacecraft and Manned Mars Station (MMS) will be monitored at frequent intervals with a real time analyzer. This analyzer will be highly automated, requiring minimal crew time and expertise. The atmospheric analyzer will find other usages during the MMMs such as analyzing Martian atmospheres and soils, exhaled breath and body fluids of crew members, and reaction products in chemical processing facilities.

Barriers to Implementing a Reporting and Learning Patient Safety System: Pediatric Chiropractic Perspective.

PubMed

Pohlman, Katherine A; Carroll, Linda; Hartling, Lisa; Tsuyuki, Ross T; Vohra, Sunita

2016-04-01

A reporting and learning system is a method of monitoring the occurrence of incidents that affect patient safety. This cross-sectional survey asked pediatric chiropractors about factors that may limit their participation in such a system. The list of potential barriers for participation was developed using a systematic approach. All members of the 2 pediatric councils associated with US national chiropractic organizations were invited to complete the survey (N = 400). The cross-sectional survey was created using an online survey tool (REDCap) and sent directly to member emails addressed by the respective executive committees. Of the 400 potential respondents, 81 responded (20.3%). The most common limitations to participating were identified as time pressure (96%) and patient concerns (81%). Reporting and learning systems have been utilized to increase safety awareness in many high-risk industries. To be successful, future patient safety studies with pediatric chiropractors need to ensure these barriers are understood and addressed. © The Author(s) 2015.

Continuous flow nanoparticle concentration using alternating current-electroosmotic flow.

PubMed

Hoettges, Kai F; McDonnell, Martin B; Hughes, Michael P

2014-02-01

Achieving real-time detection of environmental pathogens such as viruses and bacterial spores requires detectors with both rapid action and a suitable detection threshold. However, most biosensors have detection limits of an order of magnitude or more above the potential infection threshold, limiting their usefulness. This can be improved through the use of automated sample preparation techniques such as preconcentration. In this paper, we describe the use of AC electroosmosis to concentrate nanoparticles from a continuous flow. Electrodes at an optimized angle across a flow cell, and energized by a 1 kHz signal, were used to push nanoparticles to one side of a flow cell, and to extract the resulting stream with a high particle concentration from that side of the flow cell. A simple model of the behavior of particles in the flow cell has been developed, which shows good agreement with experimental results. The method indicates potential for higher concentration factors through cascading devices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Excision of a viral reprogramming cassette by delivery of synthetic Cre mRNA

PubMed Central

Loh, Yuin-Han; Yang, Jimmy Chen; De Los Angeles, Alejandro; Guo, Chunguang; Cherry, Anne; Rossi, Derrick J.; Park, In-Hyun; Daley, George Q.

2012-01-01

The generation of patient-specific induced pluripotent stem (iPS) cells provides an invaluable resource for cell therapy, in vitro modeling of human disease, and drug screening. To date, most human iPS cells have been generated with integrating retro- and lenti-viruses and are limited in their potential utility because residual transgene expression may alter their differentiation potential or induce malignant transformation. Alternatively, transgene-free methods using adenovirus and protein transduction are limited by low efficiency. This report describes a protocol for the generation of transgene-free human induced pluripotent stem cells using retroviral transfection of a single vector, which includes the coding sequences of human OCT4, SOX2, KLF4, and cMYC linked with picornaviral 2A plasmids. Moreover, after reprogramming has been achieved, this cassette can be removed using mRNA transfection of Cre recombinase. The method described herein to excise reprogramming factors with ease and efficiency facilitates the experimental generation and use of transgene-free human iPS cells. PMID:22605648