Nanostructured Mineral Coatings Stabilize Proteins for Therapeutic Delivery.

PubMed

Yu, Xiaohua; Biedrzycki, Adam H; Khalil, Andrew S; Hess, Dalton; Umhoefer, Jennifer M; Markel, Mark D; Murphy, William L

2017-09-01

Proteins tend to lose their biological activity due to their fragile structural conformation during formulation, storage, and delivery. Thus, the inability to stabilize proteins in controlled-release systems represents a major obstacle in drug delivery. Here, a bone mineral inspired protein stabilization strategy is presented, which uses nanostructured mineral coatings on medical devices. Proteins bound within the nanostructured coatings demonstrate enhanced stability against extreme external stressors, including organic solvents, proteases, and ethylene oxide gas sterilization. The protein stabilization effect is attributed to the maintenance of protein conformational structure, which is closely related to the nanoscale feature sizes of the mineral coatings. Basic fibroblast growth factor (bFGF) released from a nanostructured mineral coating maintains its biological activity for weeks during release, while it maintains activity for less than 7 d during release from commonly used polymeric microspheres. Delivery of the growth factors bFGF and vascular endothelial growth factor using a mineral coated surgical suture significantly improves functional Achilles tendon healing in a rabbit model, resulting in increased vascularization, more mature collagen fiber organization, and a two fold improvement in mechanical properties. The findings of this study demonstrate that biomimetic interactions between proteins and nanostructured minerals provide a new, broadly applicable mechanism to stabilize proteins in the context of drug delivery and regenerative medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aetiological influences on stability and change in emotional and behavioural problems across development: a systematic review.

PubMed

Hannigan, L J; Walaker, N; Waszczuk, M A; McAdams, T A; Eley, T C

2017-01-01

Emotional and behavioural problems in childhood and adolescence can be chronic and are predictive of future psychiatric problems. Understanding what factors drive the development and maintenance of these problems is therefore crucial. Longitudinal behavioural genetic studies using twin, sibling or adoption data can be used to explore the developmental aetiology of stability and change in childhood and adolescent psychopathology. We present a systematic review of longitudinal, behavioural genetic analyses of emotional and behavioural problems between ages 0 to 18 years. We identified 58 studies, of which 19 examined emotional problems, 30 examined behavioural problems, and 9 examined both. In the majority of studies, stability in emotional and behavioural problems was primarily genetically influenced. Stable environmental factors were also widely found, although these typically played a smaller role. Both genetic and environmental factors were involved in change across development. We discuss the findings in the context of the wider developmental literature and make recommendations for future research.

Aetiological influences on stability and change in emotional and behavioural problems across development: a systematic review

PubMed Central

Hannigan, L.J.; Walaker, N.; Waszczuk, M.A.; McAdams, T.A.; Eley, T.C.

2016-01-01

Emotional and behavioural problems in childhood and adolescence can be chronic and are predictive of future psychiatric problems. Understanding what factors drive the development and maintenance of these problems is therefore crucial. Longitudinal behavioural genetic studies using twin, sibling or adoption data can be used to explore the developmental aetiology of stability and change in childhood and adolescent psychopathology. We present a systematic review of longitudinal, behavioural genetic analyses of emotional and behavioural problems between ages 0 to 18 years. We identified 58 studies, of which 19 examined emotional problems, 30 examined behavioural problems, and 9 examined both. In the majority of studies, stability in emotional and behavioural problems was primarily genetically influenced. Stable environmental factors were also widely found, although these typically played a smaller role. Both genetic and environmental factors were involved in change across development. We discuss the findings in the context of the wider developmental literature and make recommendations for future research. PMID:28337341

Plant ecology. Anthropogenic environmental changes affect ecosystem stability via biodiversity.

PubMed

Hautier, Yann; Tilman, David; Isbell, Forest; Seabloom, Eric W; Borer, Elizabeth T; Reich, Peter B

2015-04-17

Human-driven environmental changes may simultaneously affect the biodiversity, productivity, and stability of Earth's ecosystems, but there is no consensus on the causal relationships linking these variables. Data from 12 multiyear experiments that manipulate important anthropogenic drivers, including plant diversity, nitrogen, carbon dioxide, fire, herbivory, and water, show that each driver influences ecosystem productivity. However, the stability of ecosystem productivity is only changed by those drivers that alter biodiversity, with a given decrease in plant species numbers leading to a quantitatively similar decrease in ecosystem stability regardless of which driver caused the biodiversity loss. These results suggest that changes in biodiversity caused by drivers of environmental change may be a major factor determining how global environmental changes affect ecosystem stability. Copyright © 2015, American Association for the Advancement of Science.

Effects of antipsychotics, antidepressants and mood stabilizers on risk for physical diseases in people with schizophrenia, depression and bipolar disorder

PubMed Central

Correll, Christoph U; Detraux, Johan; De Lepeleire, Jan; De Hert, Marc

2015-01-01

People with severe mental illness have a considerably shorter lifespan than the general population. This excess mortality is mainly due to physical illness. Next to mental illness-related factors, unhealthy lifestyle, and disparities in health care access and utilization, psychotropic medications can contribute to the risk of physical morbidity and mortality. We systematically reviewed the effects of antipsychotics, antidepressants and mood stabilizers on physical health outcomes in people with schizophrenia, depression and bipolar disorder. Updating and expanding our prior systematic review published in this journal, we searched MEDLINE (November 2009 - November 2014), combining the MeSH terms of major physical disease categories (and/or relevant diseases within these categories) with schizophrenia, major depressive disorder and bipolar disorder, and the three major psychotropic classes which received regulatory approval for these disorders, i.e., antipsychotics, antidepressants and mood stabilizers. We gave precedence to results from (systematic) reviews and meta-analyses wherever possible. Antipsychotics, and to a more restricted degree antidepressants and mood stabilizers, are associated with an increased risk for several physical diseases, including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, hyponatremia; cardiovascular, respiratory tract, gastrointestinal, haematological, musculoskeletal and renal diseases, as well as movement and seizure disorders. Higher dosages, polypharmacy, and treatment of vulnerable (e.g., old or young) individuals are associated with greater absolute (elderly) and relative (youth) risk for most of these physical diseases. To what degree medication-specific and patient-specific risk factors interact, and how adverse outcomes can be minimized, allowing patients to derive maximum benefits from these medications, requires adequate clinical attention and further research. PMID:26043321

Comparison of slope stability in two Brazilian municipal landfills.

PubMed

Gharabaghi, B; Singh, M K; Inkratas, C; Fleming, I R; McBean, E

2008-01-01

The implementation of landfill gas to energy (LFGTE) projects has greatly assisted in reducing the greenhouse gases and air pollutants, leading to an improved local air quality and reduced health risks. The majority of cities in developing countries still dispose of their municipal waste in uncontrolled 'open dumps.' Municipal solid waste landfill construction practices and operating procedures in these countries pose a challenge to implementation of LFGTE projects because of concern about damage to the gas collection infrastructure (horizontal headers and vertical wells) caused by minor, relatively shallow slumps and slides within the waste mass. While major slope failures can and have occurred, such failures in most cases have been shown to involve contributory factors or triggers such as high pore pressures, weak foundation soil or failure along weak geosynthetic interfaces. Many researchers who have studied waste mechanics propose that the shear strength of municipal waste is sufficient such that major deep-seated catastrophic failures under most circumstances require such contributory factors. Obviously, evaluation of such potential major failures requires expert analysis by geotechnical specialists with detailed site-specific information regarding foundation soils, interface shearing resistances and pore pressures both within the waste and in clayey barrier layers or foundation soils. The objective of this paper is to evaluate the potential use of very simple stability analyses which can be used to study the potential for slumps and slides within the waste mass and which may represent a significant constraint on construction and development of the landfill, on reclamation and closure and on the feasibility of a LFGTE project. The stability analyses rely on site-specific but simple estimates of the unit weight of waste and the pore pressure conditions and use "generic" published shear strength envelopes for municipal waste. Application of the slope stability analysis method is presented in a case study of two Brazilian landfill sites; the Cruz das Almas Landfill in Maceio and the Muribeca Landfill in Recife. The Muribeca site has never recorded a slope failure and is much larger and better-maintained when compared to the Maceio site at which numerous minor slumps and slides have been observed. Conventional limit-equilibrium analysis was used to calculate factors of safety for stability of the landfill side slopes. Results indicate that the Muribeca site is more stable with computed factors of safety values in the range 1.6-2.4 compared with computed values ranging from 0.9 to 1.4 for the Maceio site at which slope failures have been known to occur. The results suggest that this approach may be useful as a screening-level tool when considering the feasibility of implementing LFGTE projects.

Stabilizing IkappaBalpha by "consensus" design.

PubMed

Ferreiro, Diego U; Cervantes, Carla F; Truhlar, Stephanie M E; Cho, Samuel S; Wolynes, Peter G; Komives, Elizabeth A

2007-01-26

IkappaBalpha is the major regulator of transcription factor NF-kappaB function. The ankyrin repeat region of IkappaBalpha mediates specific interactions with NF-kappaB dimers, but ankyrin repeats 1, 5 and 6 display a highly dynamic character when not in complex with NF-kappaB. Using chemical denaturation, we show here that IkappaBalpha displays two folding transitions: a non-cooperative conversion under weak perturbation, and a major cooperative folding phase upon stronger insult. Taking advantage of a native Trp residue in ankyrin repeat (AR) 6 and engineered Trp residues in AR2, AR4 and AR5, we show that the cooperative transition involves AR2 and AR3, while the non-cooperative transition involves AR5 and AR6. The major structural transition can be affected by single amino acid substitutions converging to the "consensus" ankyrin repeat sequence, increasing the native state stability significantly. We further characterized the structural and dynamic properties of the native state ensemble of IkappaBalpha and the stabilized mutants by H/(2)H exchange mass spectrometry and NMR. The solution experiments were complemented with molecular dynamics simulations to elucidate the microscopic origins of the stabilizing effect of the consensus substitutions, which can be traced to the fast conformational dynamics of the folded ensemble.

Effects of control laws and relaxed static stability on vertical ride quality of flexible aircraft

NASA Technical Reports Server (NTRS)

Roberts, P. A.; Swaim, R. L.; Schmidt, D. K.; Hinsdale, A. J.

1977-01-01

State variable techniques are utilized to generate the RMS vertical load factors for the B-52H and B-1 bombers at low level, mission critical, cruise conditions. A ride quality index is proposed to provide meaningful comparisons between different controls or conditions. Ride quality is shown to be relatively invariant under various popular control laws. Handling quality variations are shown to be major contributors to ride quality variations on both vehicles. Relaxed static stability is artificially implemented on the study vehicles to investigate its effects on ride quality. The B-52H ride quality is generally degraded when handling characteristics are automatically restored by a feedback control to the original values from relaxed stability conditions. The B-1 airplane shows little ride quality sensitivity to the same analysis due to the small rigid body contribution to load factors at the flight condition investigated.

INFILTRATION ON MOUNTAIN SLOPES: A COMPARISON OF THREE ENVIRONMENTS. (R825157)

EPA Science Inventory

Water is well established as a major driver of the geomorphic change that eventually reduces mountains to lower relief landscapes. Nonetheless, within the altitudinal limits of continuous vegetation in humid climates, water is also an essential factor in slope stability. In th...

[The psychological analysis of patients with tinnitus].

PubMed

Cai, Qing; Li, Jun; Tao, Zezhang; Huang, Zhiwu; Ma, Zhelan; Cao, Yongmao

2004-04-01

To investigate the psychological factor of tinnitus and assess the possible influenced aspects. To inspect the 95 cases with tinnitus by SCL-90, the 9 items were divided to 10 factors and compared to the Chinese normalizations. There were significant difference between 4 factors including: somatization, depression, anxiety, compel symptom and normalization (P<0.05). There were correlation between the emotion, age and educational level and psychological dysfunction of tinnitus. Psychoprophylaxis is the important factors to tinnitus, and the major influenced aspects are age, educational level and emotional stability.

Vitamin K antagonist use: evidence of the difficulty of achieving and maintaining target INR range and subsequent consequences.

PubMed

Schein, Jeff R; White, C Michael; Nelson, Winnie W; Kluger, Jeffrey; Mearns, Elizabeth S; Coleman, Craig I

2016-01-01

Vitamin K antagonists (VKAs) are effective oral anticoagulants that are titrated to a narrow therapeutic international normalized ratio (INR) range. We reviewed published literature assessing the impact of INR stability - getting into and staying in target INR range - on outcomes including thrombotic events, major bleeding, and treatment costs, as well as key factors that impact INR stability. A time in therapeutic range (TTR) of ≥65 % is commonly accepted as the definition of INR stability. In the real-world setting, this is seldom achieved with standard-of-care management, thus increasing the patients' risks of thrombotic or major bleeding events. There are many factors associated with poor INR control. Being treated in community settings, newly initiated on a VKA, younger in age, or nonadherent to therapy, as well as having polymorphisms of CYP2C9 or VKORC1, or multiple physical or mental co-morbid disease states have been associated with lower TTR. Clinical prediction tools are available, though they can only explain <10 % of the variance behind poor INR control. Clinicians caring for patients who require anticoagulation are encouraged to intensify diligence in INR management when using VKAs and to consider appropriate use of newer anticoagulants as a therapeutic option.

Stability analysis and hazard assessment of the northern slopes of San Vicente Volcano in central El Salvador

NASA Astrophysics Data System (ADS)

Smith, Daniel M.

Geologic hazards affect the lives of millions of people worldwide every year. El Salvador is a country that is regularly affected by natural disasters, including earthquakes, volcanic eruptions and tropical storms. Additionally, rainfall-induced landslides and debris flows are a major threat to the livelihood of thousands. The San Vicente Volcano in central El Salvador has a recurring and destructive pattern of landslides and debris flows occurring on the northern slopes of the volcano. In recent memory there have been at least seven major destructive debris flows on San Vicente volcano. Despite this problem, there has been no known attempt to study the inherent stability of these volcanic slopes and to determine the thresholds of rainfall that might lead to slope instability. This thesis explores this issue and outlines a suggested method for predicting the likelihood of slope instability during intense rainfall events. The material properties obtained from a field campaign and laboratory testing were used for a 2-D slope stability analysis on a recent landslide on San Vicente volcano. This analysis confirmed that the surface materials of the volcano are highly permeable and have very low shear strength and provided insight into the groundwater table behavior during a rainstorm. The biggest factors on the stability of the slopes were found to be slope geometry, rainfall totals and initial groundwater table location. Using the results from this analysis a stability chart was created that took into account these main factors and provided an estimate of the stability of a slope in various rainfall scenarios. This chart could be used by local authorities in the event of a known extreme rainfall event to help make decisions regarding possible evacuation. Recommendations are given to improve the methodology for future application in other areas as well as in central El Salvador.

Infiltration on mountain slopes: a comparison of three environments.

Treesearch

Carol P. Harden*; P. Delmas Scruggs

2003-01-01

Water is well established as a major driver of the geomorphic change that eventually reduces mountains to lower relief landscapes. Nonetheless, within the altitudinal limits of continuous vegetation in humid climates, water is also an essential factor in slope stability. In this paper, we present results from field experiments to determine infiltration rates at...

Zein nanoparticles and the strategies to improve the colloidal stability: a mini review

NASA Astrophysics Data System (ADS)

Pascoli, Mônica; de Lima, Renata; Fraceto, Leonardo F.

2018-01-01

Zein, a protein extracted from maize, can be employed to easily produce nanoscale particles suitable for use as carrier systems. This review investigates the main methods for obtaining zein nanoparticles, as well as the problems and options available in the development of stable colloidal suspensions. Considerable gaps were identified in the literature concerning this topic, with studies being unclear about the factors that affect the stability of zein particles. In the vast majority of cases, no data are presented in relation to the stability of the formulations over time. It could be concluded that in order to produce a high quality system, detailed evaluation is required, considering factors including the zein concentration, pH, ionic strength, thermal treatment of the protein prior to preparation of the nanoparticles, strategies employing other materials as coatings, and the storage conditions. It is extremely important that these aspects should be considered during product development, prior to commercial-scale manufacture.

Zein Nanoparticles and Strategies to Improve Colloidal Stability: A Mini-Review

PubMed Central

Pascoli, Mônica; de Lima, Renata; Fraceto, Leonardo F.

2018-01-01

Zein, a protein extracted from maize, can be employed to easily produce nanoscale particles suitable for use as carrier systems. This review investigates the main methods for obtaining zein nanoparticles, as well as the problems and options available in the development of stable colloidal suspensions. Considerable gaps were identified in the literature concerning this topic, with studies being unclear about the factors that affect the stability of zein particles. In the vast majority of cases, no data are presented in relation to the stability of the formulations over time. It could be concluded that in order to produce a high quality system, detailed evaluation is required, considering factors including the zein concentration, pH, ionic strength, thermal treatment of the protein prior to preparation of the nanoparticles, strategies employing other materials as coatings, and the storage conditions. It is extremely important that these aspects should be considered during product development, prior to commercial-scale manufacture. PMID:29473032

Freeze-drying of nanosuspensions, 1: freezing rate versus formulation design as critical factors to preserve the original particle size distribution.

PubMed

Beirowski, Jakob; Inghelbrecht, Sabine; Arien, Albertina; Gieseler, Henning

2011-05-01

It has been recently reported in the literature that using a fast freezing rate during freeze-drying of drug nanosuspensions is beneficial to preserve the original particle size distribution. All freezing rates studied were obtained by utilizing a custom-made apparatus and were then indirectly related to conventional vial freeze-drying. However, a standard freeze-dryer is only capable of achieving moderate freezing rates in the shelf fluid circulation system. Therefore, it was the purpose of the present study to evaluate the possibility to establish a typical freezing protocol applicable to a standard freeze-drying unit in combination with an adequate choice of cryoprotective excipients and steric stabilizers to preserve the original particle size distribution. Six different drug nanosuspensions containing itraconazole as a drug model were studied using freeze-thaw experiments and a full factorial design to reveal major factors for the stabilization of drug nanosuspensions and the corresponding interactions. In contrast to previous reports, the freezing regime showed no significant influence on preserving the original particle size distribution, suggesting that the concentrations of both the steric stabilizer and the cryoprotective agent are optimized. Moreover, it could be pinpointed that the combined effect of steric stabilizer and cryoprotectant clearly contribute to nanoparticle stability. Copyright © 2010 Wiley-Liss, Inc.

Development of side-chain NLO polymer materials with high electro-optic activity and long-term stability

NASA Astrophysics Data System (ADS)

Huang, Diyun; Parker, Timothy; Guan, Hann Wen; Cong, Shuxin; Jin, Danliang; Dinu, Raluca; Chen, Baoquan; Tolstedt, Don; Wolf, Nick; Condon, Stephen

2005-01-01

The electro-optic coefficient and long-term dipole alignment stability are two major factors in the development of high performance NLO materials for the application of high-speed EO devices. We have developed a high performance non-linear organic chromophore and incorporated it into a crosslinkable side-chain polyimide system. The polymer was synthesized through stepwise grafting of the crosslinker followed by the chromophore onto the polyimide backbone via esterification. Different chromophore loading levels were achieved by adjusting the crosslinker/chromophore feeding ratio. The polyimides films were contact-poled with second-harmonic generation monitoring. A large EO coefficient value was obtained and good long-term thermal stability at 85°C was observed.

Robust rotation of rotor in a thermally driven nanomotor

PubMed Central

Cai, Kun; Yu, Jingzhou; Shi, Jiao; Qin, Qing-Hua

2017-01-01

In the fabrication of a thermally driven rotary nanomotor with the dimension of a few nanometers, fabrication and control precision may have great influence on rotor’s stability of rotational frequency (SRF). To investigate effects of uncertainty of some major factors including temperature, tube length, axial distance between tubes, diameter of tubes and the inward radial deviation (IRD) of atoms in stators on the frequency’s stability, theoretical analysis integrating with numerical experiments are carried out. From the results obtained via molecular dynamics simulation, some key points are illustrated for future fabrication of the thermal driven rotary nanomotor. PMID:28393898

PATTERNS OF SOIL ORGANIC MATTER STABILIZATION IN A TRANSECT OF MATURE FORESTS IN THE PACIFIC NORTHWEST USA

EPA Science Inventory

Ecosystem soils influence the cycling of nutrients, movement and storage of water, and serve as an important global reservoir of carbon (C). The accumulation and storage of C in soils is a major factor in the global C cycle and is crucial for sustaining ecosystem health and func...

Mutational Effects on Protein Folding Stability and Antigenicity: The Case of Streptococcal Pyrogenic Exotoxin A

DTIC Science & Technology

2003-01-01

1]. SPEA1 is a major virulence factor released by Streptococcus pyogenes and is associated with scarlet fever and severe invasive infections [1–4...Selander, J.M. Musser, Character- ization and clonal distribution of four alleles of the speA gene en- coding pyrogenic exotoxin A ( scarlet fever toxin

USING RADIOCARBON TO ASSESS SOIL ORGANIC MATTER STABILIZATION IN A TRANSECT OF MATURE FORESTS IN THE PACIFIC NORTHWEST USA

EPA Science Inventory

Soils influence the cycling of nutrients, movement and storage of water, and serve as an important global reservoir of carbon (C). The accumulation and storage of C in soils is a major factor in the global C cycle and is crucial for sustaining ecosystem health and function, yet ...

New insights into structural determinants of prion protein folding and stability.

PubMed

Benetti, Federico; Legname, Giuseppe

2015-01-01

Prions are the etiological agent of fatal neurodegenerative diseases called prion diseases or transmissible spongiform encephalopathies. These maladies can be sporadic, genetic or infectious disorders. Prions are due to post-translational modifications of the cellular prion protein leading to the formation of a β-sheet enriched conformer with altered biochemical properties. The molecular events causing prion formation in sporadic prion diseases are still elusive. Recently, we published a research elucidating the contribution of major structural determinants and environmental factors in prion protein folding and stability. Our study highlighted the crucial role of octarepeats in stabilizing prion protein; the presence of a highly enthalpically stable intermediate state in prion-susceptible species; and the role of disulfide bridge in preserving native fold thus avoiding the misfolding to a β-sheet enriched isoform. Taking advantage from these findings, in this work we present new insights into structural determinants of prion protein folding and stability.

Effect of hydraulic hysteresis on the stability of infinite slopes under steady infiltration

USGS Publications Warehouse

Chen, Pan; Mirus, Benjamin B.; Lu, Ning; Godt, Jonathan W.

2017-01-01

Hydraulic hysteresis, including capillary soil water retention (SWR), air entrapment SWR, and hydraulic conductivity, is a common phenomenon in unsaturated soils. However, the influence of hydraulic hysteresis on suction stress, and subsequently slope stability, is generally ignored. This paper examines the influence of each of these three types of hysteresis on slope stability using an infinite slope stability analysis under steady infiltration conditions. First, hypothetical slopes for representative silty and sandy soils are examined. Then a monitored hillslope in the San Francisco Bay Area, California is assessed, using observed rainfall conditions and measured hydraulic and geotechnical properties of the colluvial soil. Results show that profiles of suction stress and the corresponding factor of safety are generally strongly affected by hydraulic hysteresis. Results suggest that each of the three types of hydraulic hysteresis may play a major role in the occurrence of slope failure, indicating that ignoring hydraulic hysteresis will likely lead to underestimates of failure potential and hence to inaccurate slope stability analysis.

Stability and change in etiological factors for alcohol use disorder and major depression.

PubMed

Torvik, Fartein Ask; Rosenström, Tom Henrik; Ystrom, Eivind; Tambs, Kristian; Røysamb, Espen; Czajkowski, Nikolai; Gillespie, Nathan; Knudsen, Gun Peggy; Kendler, Kenneth S; Reichborn-Kjennerud, Ted

2017-08-01

Alcohol use disorder (AUD) and major depressive disorder (MDD) are often comorbid. It is not understood how genetic risk factors for these disorders relate to each other over time and to what degree they are stable. Age-dependent characteristics of the disorders indicate that different genetic factors could be relevant at different stages of life, and MDD may become increasingly correlated with AUD over time. DSM-IV diagnoses of AUD and MDD were assessed by interviews of 2,801 young adult twins between 1999 and 2004 (T1) and 2,284 of the same twins between 2010 and 2011 (T2). Stability, change, and covariation were investigated in longitudinal biometric models. New genetic factors explained 56.4% of the genetic variance in AUD at T2. For MDD, there was full overlap between genetic influences at T1 and T2. Genetic risk factors for MDD were related to AUD, but their association with AUD did not increase over time. Thus, genetic risk factors for AUD, but not MDD, vary with age, suggesting that AUD has age-dependent heritable etiologies. Molecular genetic studies of AUD may therefore benefit from stratifying by age. The new genetic factors in AUD were not related to MDD. Environmental influences on the 2 disorders were correlated in middle, but not in young adulthood. The environmental components for AUD correlated over time (r = .27), but not for MDD. Environmental influences on AUD can have long-lasting effects, and the effects of preventive efforts may be enduring. Environment influences seem to be largely transient. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Telomeres and replicative senescence: Is it only length that counts?

PubMed

von Zglinicki, T

2001-07-26

Telomeres are well established as a major 'replicometer', counting the population doublings in primary human cell cultures and ultimately triggering replicative senescence. However, neither is the pace of this biological clock inert, nor is there a fixed threshold telomere length acting as the universal trigger of replicative senescence. The available data suggest that opening of the telomeric loop and unscheduled exposure of the single-stranded G-rich telomeric overhang might act like a semaphore to signal senescent cell cycle arrest. Short telomere length, telomeric single-strand breaks, low levels of loop-stabilizing proteins, or other factors may trigger this opening of the loop. Thus, both telomere shortening and the ultimate signalling into senescence are able to integrate different environmental and genetic factors, especially oxidative stress-mediated damage, which might otherwise become a thread to genomic stability.

Closed-loop optical stabilization and digital image registration in adaptive optics scanning light ophthalmoscopy

PubMed Central

Yang, Qiang; Zhang, Jie; Nozato, Koji; Saito, Kenichi; Williams, David R.; Roorda, Austin; Rossi, Ethan A.

2014-01-01

Eye motion is a major impediment to the efficient acquisition of high resolution retinal images with the adaptive optics (AO) scanning light ophthalmoscope (AOSLO). Here we demonstrate a solution to this problem by implementing both optical stabilization and digital image registration in an AOSLO. We replaced the slow scanning mirror with a two-axis tip/tilt mirror for the dual functions of slow scanning and optical stabilization. Closed-loop optical stabilization reduced the amplitude of eye-movement related-image motion by a factor of 10–15. The residual RMS error after optical stabilization alone was on the order of the size of foveal cones: ~1.66–2.56 μm or ~0.34–0.53 arcmin with typical fixational eye motion for normal observers. The full implementation, with real-time digital image registration, corrected the residual eye motion after optical stabilization with an accuracy of ~0.20–0.25 μm or ~0.04–0.05 arcmin RMS, which to our knowledge is more accurate than any method previously reported. PMID:25401030

A study of a steering system algorithm for pleasure boats based on stability analysis of a human-machine system model

NASA Astrophysics Data System (ADS)

Ikeda, Fujio; Toyama, Shigehiro; Ishiduki, Souta; Seta, Hiroaki

2016-09-01

Maritime accidents of small ships continue to increase in number. One of the major factors is poor manoeuvrability of the Manual Hydraulic Steering Mechanism (MHSM) in common use. The manoeuvrability can be improved by using the Electronic Control Steering Mechanism (ECSM). This paper conducts stability analyses of a pleasure boat controlled by human models in view of path following on a target course, in order to establish design guidelines for the ECSM. First, to analyse the stability region, the research derives the linear approximated model in a planar global coordinate system. Then, several human models are assumed to develop closed-loop human-machine controlled systems. These human models include basic proportional, derivative, integral and time-delay actions. The stability analysis simulations for those human-machine systems are carried out. The results show that the stability region tends to spread as a ship's velocity increases in the case of the basic proportional human model. The derivative action and time-delay action of human models are effective in spreading the stability region in their respective ranges of frontal gazing points.

Combined line-of-sight error and angular position to generate feedforward control for a charge-coupled device-based tracking loop

NASA Astrophysics Data System (ADS)

Tang, Tao; Cai, Huaxiang; Huang, Yongmei; Ren, Ge

2015-10-01

A feedforward control based on data fusion is proposed to enhance closed-loop performance. The target trajectory as the observed value of a Kalman filter is recovered by synthesizing line-of-sight error and angular position from the encoder. A Kalman filter based on a Singer acceleration model is employed to estimate the target velocity. In this control scheme, the control stability is influenced by the bandwidth of the Kalman filter and time misalignment. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability, which shows that the Kalman filter is the major factor that affects the control stability. The feedforward control proposed here is verified through simulations and experiments.

Personality Plasticity After Age 30

PubMed Central

Terracciano, Antonio; Costa, Paul T.; McCrae, Robert R.

2009-01-01

Rank-order consistency of personality traits increases from childhood to age 30. After that, different summaries of the literature predict a plateau at age 30, or at age 50, or a curvilinear peak in consistency at age 50. These predictions were evaluated at group and individual levels using longitudinal data from the Guilford-Zimmerman Temperament Survey and the Revised NEO Personality Inventory over periods of up to 42 years. Consistency declined toward a non-zero asymptote with increasing time-interval. Although some scales showed increasing stability after age 30, the rank-order consistencies of the major dimensions and most facets of the Five-Factor Model were unrelated to age. Ipsative stability, assessed with the California Adult Q-Set, was also unrelated to age. These data strengthen claims of predominant personality stability after age 30. PMID:16861305

Single Null Negative Triangularity Tokamak for Power Handling

NASA Astrophysics Data System (ADS)

Kikuchi, Mitsuru; Medvedev, S.; Takizuka, T.; Sauter, O.; Merle, A.; Coda, S.; Chen, D.; Li, J. X.

2017-10-01

Power and particle control in fusion reactor is challenge and we proposed the negative triangularity tokamak (NTT) to eliminate ELM by operating L-mode edge with improved core confinement. The SN configuration has more flexibility in shaping by adopting rectangular-shaped TF coils. The limiting normalized beta is 3.56 with wall stabilization and 3.14 without wall. The vertical stability is assured under a reasonable control system. The wetted area on the divertor plates becomes wider in proportion to the larger major radius at the divertor strike points due to the NT configuration. In addition to the major-radius effect, the ``Flux Tune Expansion (FTE)'' is adopted to further reduce the heat load on the divertor plate by factor of 2.6 with a coil current 3 MA. L-mode edge also allows further increase in wetted area. The fusion power of 3 GW is deliverable only at normalized beta 2.1. Therefore this reactor may be operable stably against the serious MHD activities. The CD power for SS operation is 175 MW at Q = 17. AC operation is also possible option. A required HH factor is relatively modest H = 1.12.

Optimization on Fc for Improvement of Stability and Aggregation Resistance.

PubMed

Chen, Xiaobo; Zeng, Fang; Huang, Tao; Cheng, Liang; Liu, Huan; Gong, Rui

2016-01-01

Fc-based therapeutics including therapeutic full-size monoclonal antibodies (mAbs) and Fcfusion proteins represent fastest-growing market in biopharmaceutical industrial. However, one major challenge during development of Fc-based therapeutics is how to maintain their efficacy in clinic use. Many factors may lead to failure in final marketing. For example, the stability and aggregation resistance might not be high enough for bearing the disadvantages during fermentation, purification, formulation, storage, shipment and other steps in manufacture and sale. Low stability and high aggregation tendency lead to decreased bioactivity and increased risk of immunogenicity resulting in serious side effect. Because Fc is one of the major parts in monoclonal antibodies and Fc-fusion proteins, engineering of Fc to increase its stability and reduce or eliminate aggregation due to incorrect association are of great importance and could further extend the potential of Fc-based therapeutics. Lots of studies focus on Fc optimization for better physical and chemical characteristics and function by structured-based computer-aid rational design, high-throughput screening expression system selection and other methods. The identification of optimized Fc mutants increases the clinic potential of currently existed therapeutics mAbs and Fc-fusion proteins, and accelerates the development of new Fc-based therapeutics. Here we provide an overview of the related field, and discuss recent advances and future directions in optimization of Fc-based therapeutics with modified stability and aggregation resistance. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Prevention of motor‐vehicle deaths by changing vehicle factors

PubMed Central

Robertson, Leon S

2007-01-01

Objective To estimate the effect of changing vehicle factors to reduce mortality in a comprehensive study. Design/methods Odds of death in the United States during 2000–2005 were analyzed, involving specific makes and models of 1999–2005 model year cars, minivans, and sport utility vehicles using logistic regression after selection of factors to be included by examination of least‐squares correlations of vehicle factors to maximize independence of predictors. Based on the regression coefficients, percentages of deaths preventable by changes in selected factors were calculated. Correlations of vehicle characteristics to environmental and behavioral risk factors were also examined to assess any potential confounding. Results Deaths in the studied vehicles would have been 42% lower had all had electronic stability control (ESC) systems. Improved crashworthiness as measured by offset frontal and side crash tests would have produced an additional 28% reduction, and static stability improvement would have reduced the deaths 11%. Although weight–power that reduces fuel economy is associated with lower risk to drivers, it increases risk of deaths to pedestrians and bicyclists but has an overall minor effect compared to the other factors. Conclusion A large majority of motor‐vehicle‐related fatalities could be avoided by universal adoption of the most effective technologies. PMID:17916886

Enhanced sensitivity in a butterfly gyroscope with a hexagonal oblique beam

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

Xiao, Dingbang; Cao, Shijie; Hou, Zhanqiang, E-mail: houzhanqiang@nudt.edu.cn

2015-04-15

A new approach to improve the performance of a butterfly gyroscope is developed. The methodology provides a simple way to improve the gyroscope’s sensitivity and stability, by reducing the resonant frequency mismatch between the drive and sense modes. This method was verified by simulations and theoretical analysis. The size of the hexagonal section oblique beam is the major factor that influences the resonant frequency mismatch. A prototype, which has the appropriately sized oblique beam, was fabricated using precise, time-controlled multilayer pre-buried masks. The performance of this prototype was compared with a non-tuned gyroscope. The scale factor of the prototype reachesmore » 30.13 mV/ °/s, which is 15 times larger than that obtained from the non-tuned gyroscope. The bias stability of the prototype is 0.8 °/h, which is better than the 5.2 °/h of the non-tuned devices.« less

Single Stance Stability and Proprioceptive Control in Older Adults Living at Home: Gender and Age Differences

PubMed Central

Riva, Dario; Mamo, Carlo; Fanì, Mara; Saccavino, Patrizia; Rocca, Flavio; Momenté, Manuel; Fratta, Marianna

2013-01-01

In developed countries, falls in older people represent a rising problem. As effective prevention should start before the risk becomes evident, an early predictor is needed. Single stance instability would appear as a major risk factor. Aims of the study were to describe single stance stability, its sensory components, and their correlation with age and gender. A random sample of 597 older adults (319 men, 278 women) living at home, aged 65–84, was studied. Stability tests were performed with an electronic postural station. The single stance test showed the impairment of single stance stability in older individuals (75–84 yrs). The significant decline of stability in the older subjects may be explained by the impairment of proprioceptive control together with the decrease in compensatory visual stabilization and emergency responses. Younger subjects (65–74 yrs) exhibited better, but still inadequate, proprioceptive control with compensatory visual stabilization. Gender differences appeared in older subjects: women were significantly less stable than men. The measurement of the sensory components of single stance stability could aid in the early detection of a decay in antigravity movements many years before the risk of falling becomes evident. Adequate proprioceptive control could mitigate the effects of all other risks of falling. PMID:23984068

Temporal Dynamics of the Human Vaginal Microbiota

PubMed Central

Gajer, Pawel; Brotman, Rebecca M.; Bai, Guoyun; Sakamoto, Joyce; Schütte, Ursel M.E.; Zhong, Xue; Koenig, Sara S.K.; Fu, Li; Ma, Zhanshan; Zhou, Xia; Abdo, Zaid; Forney, Larry J.; Ravel, Jacques

2012-01-01

Elucidating the factors that impinge on the stability of bacterial communities in the vagina may help in predicting the risk of diseases that affect women’s health. Here, we describe the temporal dynamics of the composition of vaginal bacterial communities in 32 reproductive age women over a 16-week period. The analysis revealed the dynamics of five major classes of bacterial communities and showed that some communities change markedly over short time periods, whereas others are relatively stable. Modeling community stability using new quantitative measures indicates that deviation from stability correlates with time in the menstrual cycle, bacterial community composition and sexual activity. The women studied are healthy, thus it appears that neither variation in community composition per se, nor higher levels of observed diversity (co-dominance) are necessarily indicative of dysbiosis, in which there is microbial imbalance accompanied by symptoms. PMID:22553250

Key issues in application of composites to transport aircraft

NASA Technical Reports Server (NTRS)

Stone, M.

1978-01-01

The application of composite materials to transport aircraft was identified and reviewed including the major contributing disciplines of design, manufacturing, and processing. Factors considered include: crashworthiness considerations (structural integrity, postcrash fires, and structural fusing), electrical/avionics subsystems integration, lightning, and P-static protection design; manufacturing development, evaluation, selection, and refining of tooling and curing procedures; and major joint design considerations. Development of the DC-10 rudder, DC-10 vertical stabilizer, and the DC-9 wing study project was reviewed. The Federal Aviation Administration interface and the effect on component design of compliance with Federal Aviation Regulation 25 Composite Guidelines are discussed.

The Deubiquitylase MATH-33 Controls DAF-16 Stability and Function in Metabolism and Longevity

PubMed Central

Heimbucher, Thomas; Liu, Zheng; Bossard, Carine; McCloskey, Richard; Carrano, Andrea C.; Riedel, Christian G.; Tanasa, Bogdan; Klammt, Christian; Fonslow, Bryan R.; Riera, Celine E.; Lillemeier, Bjorn F.; Kemphues, Kenneth; Yates, John R.; O'Shea, Clodagh; Hunter, Tony; Dillin, Andrew

2015-01-01

SUMMARY One of the major determinants of aging in organisms ranging from worms to man are FOXO family transcription factors, which are downstream effectors of Insulin/IGF-1 signaling (IIS). The molecular mechanisms that actively promote DAF16/FOXO stability and function are unknown. Here we identify the deubiquitylating enzyme MATH-33 as an essential DAF-16 regulator in IIS, which stabilizes active DAF-16 protein levels and, as a consequence, influences DAF-16 functions, such as metabolism, stress response and longevity in C. elegans. MATH-33 associates with DAF-16 in cellulo and in vitro. MATH-33 functions as a deubiquitylase by actively removing ubiquitin moieties from DAF-16, thus counteracting the action of the RLE-1 E3-ubiquitin ligase. Our findings support a model in which MATH-33 promotes DAF-16 stability in response to decreased IIS by directly modulating its ubiquitylation state, suggesting that regulated oscillations in the stability of DAF-16 protein play an integral role in controlling processes such as metabolism and longevity. PMID:26154057

Influence of formulation and processing factors on stability of levothyroxine sodium pentahydrate.

PubMed

Collier, Jarrod W; Shah, Rakhi B; Gupta, Abhay; Sayeed, Vilayat; Habib, Muhammad J; Khan, Mansoor A

2010-06-01

Stability of formulations over shelf-life is critical for having a quality product. Choice of excipients, manufacturing process, storage conditions, and packaging can either mitigate or enhance the degradation of the active pharmaceutical ingredient (API), affecting potency and/or stability. The purpose was to investigate the influence of processing and formulation factors on stability of levothyroxine (API). The API was stored at long-term (25 degrees C/60%RH), accelerated (40 degrees C/75%RH), and low-humidity (25 degrees C/0%RH and 40 degrees C/0%RH) conditions for 28 days. Effect of moisture loss was evaluated by drying it (room temperature, N(2)) and placed at 25 degrees C/0%RH and 40 degrees C/0%RH. The API was incubated with various excipients (based on package insert of marketed tablets) in either 1:1, 1:10, or 1:100 ratios with 5% moisture at 60 degrees C. Commonly used ratios for excipients were used. The equilibrium sorption data was collected on the API and excipients. The API was stable in solid state for the study duration under all conditions for both forms (potency between 90% and 110%). Excipients effect on stability varied and crospovidone, povidone, and sodium laurel sulfate (SLS) caused significant API degradation where deiodination and deamination occurred. Moisture sorption values were different across excipients. Crospovidone and povidone were hygroscopic whereas SLS showed deliquescence at high RH. The transient formulation procedures where temperature might go up or humidity might go down would not have major impact on the API stability. Excipients influence stability and if possible, those three should either be avoided or used in minimum quantity which could provide more stable tablet formulations with minimum potency loss throughout its shelf-life.

Inducible defenses in food webs: Chapter 3.4

USGS Publications Warehouse

Vos, Matthijs; Kooi, Bob W.; DeAngelis, Donald L.; Mooij, Wolf M.; de Ruiter, Peter; Wolters, Volkmar; Moore, John C.; Melville-Smith, Kimberly

2005-01-01

This chapter reviews the predicted effects of induced defenses on trophic structure and two aspects of stability, “local” stability and persistence, as well as presenting novel results on a third, resilience. Food webs are structures of populations in a given location organized according to their predator–prey interactions. Interaction strengths and, therefore, prey defenses are generally recognized as important ecological factors affecting food webs. Despite this, surprisingly, little light has been shed on the food web-level consequences of inducible defenses. Inducible defenses occur in many taxa in both terrestrial and aquatic food webs. They include refuge use, reduced activity, adaptive life history changes, the production of toxins, synomones and extrafloral nectar, and the formation of colonies, helmets, thorns, or spines. In the chapter, theoretical results for the effects of inducible defenses on trophic structure and the three aspects of stability are reviewed. This is done, in part, using bifurcation analysis—a type of analysis that is applied to nonlinear dynamic systems described by a set of ordinary differential or difference equations. The work presented in the chapter suggests that heterogeneity, as caused by induced defenses in prey species, has major effects on the functioning of food webs. Inducible defenses occur in many species in both aquatic and terrestrial systems, and theoretical work indicates they have major effects on important food web properties such as trophic structure, local stability, persistence, and resilience.

Trade-off study and computer simulation for assessing spacecraft pointing accuracy and stability capabilities

NASA Astrophysics Data System (ADS)

Algrain, Marcelo C.; Powers, Richard M.

1997-05-01

A case study, written in a tutorial manner, is presented where a comprehensive computer simulation is developed to determine the driving factors contributing to spacecraft pointing accuracy and stability. Models for major system components are described. Among them are spacecraft bus, attitude controller, reaction wheel assembly, star-tracker unit, inertial reference unit, and gyro drift estimators (Kalman filter). The predicted spacecraft performance is analyzed for a variety of input commands and system disturbances. The primary deterministic inputs are the desired attitude angles and rate set points. The stochastic inputs include random torque disturbances acting on the spacecraft, random gyro bias noise, gyro random walk, and star-tracker noise. These inputs are varied over a wide range to determine their effects on pointing accuracy and stability. The results are presented in the form of trade- off curves designed to facilitate the proper selection of subsystems so that overall spacecraft pointing accuracy and stability requirements are met.

The lucky image-motion prediction for simple scene observation based soft-sensor technology

NASA Astrophysics Data System (ADS)

Li, Yan; Su, Yun; Hu, Bin

2015-08-01

High resolution is important to earth remote sensors, while the vibration of the platforms of the remote sensors is a major factor restricting high resolution imaging. The image-motion prediction and real-time compensation are key technologies to solve this problem. For the reason that the traditional autocorrelation image algorithm cannot meet the demand for the simple scene image stabilization, this paper proposes to utilize soft-sensor technology in image-motion prediction, and focus on the research of algorithm optimization in imaging image-motion prediction. Simulations results indicate that the improving lucky image-motion stabilization algorithm combining the Back Propagation Network (BP NN) and support vector machine (SVM) is the most suitable for the simple scene image stabilization. The relative error of the image-motion prediction based the soft-sensor technology is below 5%, the training computing speed of the mathematical predication model is as fast as the real-time image stabilization in aerial photography.

Influence of encapsulated functional lipids on crystal structure and chemical stability in solid lipid nanoparticles: Towards bioactive-based design of delivery systems.

PubMed

Salminen, Hanna; Gömmel, Christina; Leuenberger, Bruno H; Weiss, Jochen

2016-01-01

We investigated the influence of physicochemical properties of encapsulated functional lipids--vitamin A, β-carotene and ω-3 fish oil--on the structural arrangement of solid lipid nanoparticles (SLN). The relationship between the crystal structure and chemical stability of the incorporated bioactive lipids was evaluated with different emulsifier compositions of a saponin-rich, food-grade Quillaja extract alone or combined with high-melting or low-melting lecithins. The major factors influencing the structural arrangement and chemical stability of functional lipids in solid lipid dispersions were their solubility in the aqueous phase and their crystallization temperature in relation to that of the carrier lipid. The results showed that the stabilization of the α-subcell crystals in the lattice of the carrier lipid is a key parameter for forming stable solid lipid dispersions. This study contributes to a better understanding of SLN as a function of the bioactive lipid. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structure of the Small Outer Capsid Protein, Soc: A Clamp for Stabilizing Capsids of T4-like Phages

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

Qin, Li; Fokine, Andrei; O'Donnell, Erin

2010-07-22

Many viruses need to stabilize their capsid structure against DNA pressure and for survival in hostile environments. The 9-kDa outer capsid protein (Soc) of bacteriophage T4, which stabilizes the virus, attaches to the capsid during the final stage of maturation. There are 870 Soc molecules that act as a 'glue' between neighboring hexameric capsomers, forming a 'cage' that stabilizes the T4 capsid against extremes of pH and temperature. Here we report a 1.9 {angstrom} resolution crystal structure of Soc from the bacteriophage RB69, a close relative of T4. The RB69 crystal structure and a homology model of T4 Soc weremore » fitted into the cryoelectron microscopy reconstruction of the T4 capsid. This established the region of Soc that interacts with the major capsid protein and suggested a mechanism, verified by extensive mutational and biochemical studies, for stabilization of the capsid in which the Soc trimers act as clamps between neighboring capsomers. The results demonstrate the factors involved in stabilizing not only the capsids of T4-like bacteriophages but also many other virus capsids.« less

Stability and predictors of change in salivary cortisol measures over six years: MESA.

PubMed

Wang, Xu; Sánchez, Brisa N; Golden, Sherita Hill; Shrager, Sandi; Kirschbaum, Clemens; Karlamangla, Arun S; Seeman, Teresa E; Roux, Ana V Diez

2014-11-01

A major challenge in characterizing features of the daily cortisol curve is variability in features over time. Few studies have examined the stability of daily features of the cortisol curve over long periods or the predictors of long term changes. Repeated salivary cortisol measures on 580 adults from the MESA Stress study were used to examine the stability of various features of the daily cortisol curve (wakeup value, the cortisol awakening response (CAR), the early and late decline slope and the area under the curve (AUC)), over short periods (several days) and long periods (approximately 6-years) and to investigate the association of demographic factors with the changes. Intraclass correlation coefficients (ICCs) were used to estimate the short and long term stability. Piecewise linear mixed models were used to assess factors associated with changes in features over time. For most features, short term stability (ICCs: 0.17-0.74) was higher than long term stability (ICCs: 0.05-0.42), and long term stability was highest when several days were averaged for each time point. The decline over the day showed the highest long term stability: when several days for each wave were averaged the stability of the daily decline slope across 6 years was similar (or higher) than the stability across short periods. AUC had high stability over short periods (ICCs: 0.65-0.74) but much lower stability across long periods (ICC: 0.05). All features of daily cortisol curve investigated changed significantly over the approximately 6 year follow-up period. The wakeup cortisol became higher; the CAR became smaller; both the early and late decline became flatter; and the AUC became larger. Hispanics experienced significantly larger increases in the wakeup value; and African-Americans and Hispanics showed less flattening over time of the early decline slope than Non-Hispanic Whites. Our findings have implications for characterization of features in studies linking cortisol to health outcomes. The presence of variability over time suggests opportunities for future investigation of the predictors of changes over time as well as the links between these changes and health outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

High stability of Stx2 phage in food and under food-processing conditions.

PubMed

Rode, Tone Mari; Axelsson, Lars; Granum, Per Einar; Heir, Even; Holck, Askild; L'abée-Lund, Trine M

2011-08-01

Bacteriophages (phages) carrying Shiga toxin genes constitute a major virulence attribute in enterohemorrhagic Escherichia coli (EHEC). Several EHEC outbreaks have been linked to food. The survival of such strains in different foods has received much attention, while the fate of the mobile Shiga toxin-converting phages (Stx phages) has been less studied. We have investigated the stability of an Stx phage in several food products and examined how storage, food processing, and disinfection influence the infectivity of phage particles. The study involved a recombinant Stx phage (Δstx::cat) of an E. coli O103:H25 strain from a Norwegian outbreak in 2006. Temperature, matrix, and time were factors of major importance for the stability of phage particles. Phages stored at cooling temperatures (4°C) showed a dramatic reduction in stability compared to those stored at room temperature. The importance of the matrix was evident at higher temperatures (60°C). Phages in ground beef were below the detection level when heated to 60°C for more than 10 min, while phages in broth exposed to the same heating conditions showed a 5-log-higher stability. The phages tolerated desiccation poorly but were infective for a substantial period of time in solutions. Under moist conditions, they also had a high ability to tolerate exposure to several disinfectants. In a dry-fermented sausage model, phages were shown to infect E. coli in situ. The results show that Stx phage particles can maintain their infectivity in foods and under food-processing conditions.

High Stability of Stx2 Phage in Food and under Food-Processing Conditions ▿

PubMed Central

Rode, Tone Mari; Axelsson, Lars; Granum, Per Einar; Heir, Even; Holck, Askild; L'Abée-Lund, Trine M.

2011-01-01

Bacteriophages (phages) carrying Shiga toxin genes constitute a major virulence attribute in enterohemorrhagic Escherichia coli (EHEC). Several EHEC outbreaks have been linked to food. The survival of such strains in different foods has received much attention, while the fate of the mobile Shiga toxin-converting phages (Stx phages) has been less studied. We have investigated the stability of an Stx phage in several food products and examined how storage, food processing, and disinfection influence the infectivity of phage particles. The study involved a recombinant Stx phage (Δstx::cat) of an E. coli O103:H25 strain from a Norwegian outbreak in 2006. Temperature, matrix, and time were factors of major importance for the stability of phage particles. Phages stored at cooling temperatures (4°C) showed a dramatic reduction in stability compared to those stored at room temperature. The importance of the matrix was evident at higher temperatures (60°C). Phages in ground beef were below the detection level when heated to 60°C for more than 10 min, while phages in broth exposed to the same heating conditions showed a 5-log-higher stability. The phages tolerated desiccation poorly but were infective for a substantial period of time in solutions. Under moist conditions, they also had a high ability to tolerate exposure to several disinfectants. In a dry-fermented sausage model, phages were shown to infect E. coli in situ. The results show that Stx phage particles can maintain their infectivity in foods and under food-processing conditions. PMID:21685156

Apoglobin Stability Is the Major Factor Governing both Cell-free and in Vivo Expression of Holomyoglobin*♦

PubMed Central

Samuel, Premila P.; Smith, Lucian P.; Phillips, George N.; Olson, John S.

2015-01-01

Expression levels in animal muscle tissues and in Escherichia coli vary widely for naturally occurring mammalian myoglobins (Mb). To explore this variation, we developed an in vitro transcription and wheat germ extract-based translation assay to examine quantitatively the factors that govern expression of holoMb. We constructed a library of naturally occurring Mbs from two terrestrial and four deep-diving aquatic mammals and three distal histidine mutants designed to enhance apoglobin stability but decrease hemin affinity. A strong linear correlation is observed between cell-free expression levels of holo-metMb variants and their corresponding apoglobin stabilities, which were measured independently by guanidine HCl-induced unfolding titrations using purified proteins. In contrast, there is little dependence of expression on hemin affinity. Our results confirm quantitatively that deep diving mammals have highly stable Mbs that express to higher levels in animal myocytes, E. coli, and the wheat germ cell-free system than Mbs from terrestrial mammals. Our theoretical analyses show that the rate of aggregation of unfolded apoMb is very large, and as a result, the key factor for high level expression of holoMb, and presumably other heme proteins, is an ultra high fraction of folded, native apoglobin that is capable of rapidly binding hemin. This fraction is determined by the overall equilibrium folding constant and not hemin affinity. These results also demonstrate that the cell-free transcription/translation system can be used as a high throughput platform to screen for apoglobin stability without the need to generate large amounts of protein for in vitro unfolding measurements. PMID:26205820

Vaccination with dendritic cell/tumor fusion cells results in cellular and humoral antitumor immune responses in patients with multiple myeloma

PubMed Central

Vasir, Baldev; Uhl, Lynne; Blotta, Simona; MacNamara, Claire; Somaiya, Poorvi; Wu, Zekui; Joyce, Robin; Levine, James D.; Dombagoda, Dilani; Yuan, Yan Emily; Francoeur, Karen; Fitzgerald, Donna; Richardson, Paul; Weller, Edie; Anderson, Kenneth; Kufe, Donald; Munshi, Nikhil; Avigan, David

2011-01-01

We have developed a tumor vaccine in which patient-derived myeloma cells are chemically fused with autologous dendritic cells (DCs) such that a broad spectrum of myeloma-associated antigens are presented in the context of DC-mediated costimulation. We have completed a phase 1 study in which patients with multiple myeloma underwent serial vaccination with the DC/multiple myeloma fusions in conjunction with granulocyte-macrophage colony-stimulating factor. DCs were generated from adherent mononuclear cells cultured with granulocyte-macrophage colony-stimulating factor, interleukin-4, and tumor necrosis factor-α and fused with myeloma cells obtained from marrow aspirates. Vaccine generation was successful in 17 of 18 patients. Successive cohorts were treated with 1 × 106, 2 × 106, and 4 × 106 fusion cells, respectively, with 10 patients treated at the highest dose level. Vaccination was well tolerated, without evidence of dose-limiting toxicity. Vaccination resulted in the expansion of circulating CD4 and CD8 lymphocytes reactive with autologous myeloma cells in 11 of 15 evaluable patients. Humoral responses were documented by SEREX (Serologic Analysis of Recombinant cDNA Expression Libraries) analysis. A majority of patients with advanced disease demonstrated disease stabilization, with 3 patients showing ongoing stable disease at 12, 25, and 41 months, respectively. Vaccination with DC/multiple myeloma fusions was feasible and well tolerated and resulted in antitumor immune responses and disease stabilization in a majority of patients. PMID:21030562

A new pharmacological agent (AKB-4924) stabilizes hypoxia inducible factor-1 (HIF-1) and increases skin innate defenses against bacterial infection.

PubMed

Okumura, Cheryl Y M; Hollands, Andrew; Tran, Dan N; Olson, Joshua; Dahesh, Samira; von Köckritz-Blickwede, Maren; Thienphrapa, Wdee; Corle, Courtney; Jeung, Seung Nam; Kotsakis, Anna; Shalwitz, Robert A; Johnson, Randall S; Nizet, Victor

2012-09-01

Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 increases HIF-1 levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinetobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections.

A New Pharmacological Agent (AKB-4924) Stabilizes Hypoxia Inducible Factor (HIF) and Increases Skin Innate Defenses Against Bacterial Infection

PubMed Central

Okumura, Cheryl Y.M.; Hollands, Andrew; Tran, Dan N.; Olson, Joshua; Dahesh, Samira; von Köckritz-Blickwede, Maren; Thienphrapa, Wdee; Corle, Courtney; Jeung, Seung Nam; Kotsakis, Anna; Shalwitz, Robert A.; Johnson, Randall S.; Nizet, Victor

2013-01-01

Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 (Akebia Therapeutics) increases HIF-1α levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and -resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinitobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections. PMID:22371073

Smooth seaward-dipping horizons - An important factor in sea-floor stability?

USGS Publications Warehouse

McGregor, B.A.

1981-01-01

Mass movement has influenced in varying degrees the morphology of the United States east coast continental margin seaward of the Baltimore Canyon trough as revealed by detailed geophysical studies using high-resolution 3.5-kHz, and seismic reflection data. Each of three areas studied is along the slope within a distance of 225 km, and is seaward of a nonglaciated shelf but near major land drainage systems. Thick sequences of material believed to be Pleistocene were deposited on the slope in all three areas. Sediment failure in the form of large block movement involving block thicknesses of more than 100 m, however, has taken place in only two of the areas. A factor common to the two areas where failure took place, but absent in the area where no failure took place, is smooth seaward-dipping sub-bottom horizons. Whatever the triggering mechanism, a smooth slip surface that has a seward slope may contribute to mass movement by reducing the internal friction. This may be one of several factors that should be considered in assessing slope stability. ?? 1981.

The evolution of conformist transmission in social learning when the environment changes periodically.

PubMed

Nakahashi, Wataru

2007-08-01

Conformity is often observed in human social learning. Social learners preferentially imitate the majority or most common behavior in many situations, though the strength of conformity varies with the situation. Why has such a psychological tendency evolved? I investigate this problem by extending a standard model of social learning evolution with infinite environmental states (Feldman, M.W., Aoki, K., Kumm, J., 1996. Individual versus social learning: evolutionary analysis in a fluctuating environment. Anthropol. Sci. 104, 209-231) to include conformity bias. I mainly focus on the relationship between the strength of conformity bias that evolves and environmental stability, which is one of the most important factors in the evolution of social learning. Using the evolutionarily stable strategy (ESS) approach, I show that conformity always evolves when environmental stability and the cost of adopting a wrong behavior are small, though environmental stability and the cost of individual learning both negatively affect the strength of conformity.

Waves on radial film flows

NASA Astrophysics Data System (ADS)

Cholemari, Murali R.; Arakeri, Jaywant H.

2005-08-01

We study the stability of surface waves on the radial film flow created by a vertical cylindrical water jet striking a horizontal plate. In such flows, surface waves have been found to be unstable and can cause transition to turbulence. This surface-wave-induced transition is different from the well-known Tollmien-Schlichting wave-induced transition. The present study aims at understanding the instability and the transition process. We do a temporal stability analysis by assuming the flow to be locally two-dimensional but including spatial variations to first order in the basic flow. The waves are found to be dispersive, mostly unstable, and faster than the mean flow. Spatial variation is the major destabilizing factor. Experiments are done to test the results of the linear stability analysis and to document the wave breakup and transition. Comparison between theory and experiments is fairly good and indicates the adequacy of the model.

Effect of pH on the stability of hemochromatosis factor E: a combined spectroscopic and molecular dynamics simulation-based study.

PubMed

Khan, Parvez; Shandilya, Ashutosh; Jayaram, B; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

2017-05-01

Hereditary hemochromatosis is an iron overburden condition, which is mainly governed by hereditary hemochromatosis factor E (HFE), a member of major histocompatibility complex class I. To understand the effect of pH on the structure and stability of HFE, we have cloned, expressed, and purified the HFE in the bacterial system and performed circular dichroism, fluorescence, and absorbance measurements at a wide pH range (pH 3.0-11.0). We found that HFE remains stable in the pH range 7.5-11.0 and gets completely acid denatured at low pH values. In this work, we also analyzed the contribution of salt bridges to the stability of HFE. We further performed molecular dynamics simulations for 80 ns at different pH values. An excellent agreement was observed between results from biophysical and MD simulation studies. At lower pH, HFE undergoes denaturation and may be driven toward a degradation pathway, such as ubiquitination. Hence, HFE is not available to bind again with transferrin receptor1 to negatively regulate iron homeostasis. Further we postulated that, might be low pH of cancerous cells helps them to meet their high iron requirement.

Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts

USGS Publications Warehouse

Bowker, M.A.; Belnap, J.; Bala, Chaudhary V.; Johnson, N.C.

2008-01-01

Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which rainfall can result in erosion), topography, soil erodibility, and land use/management. The soil erodibility factor (K) is primarily based upon inherent soil properties (those which change slowly or not at all) such as soil texture and organic matter content, while the cover/management factor (C) is based on several parameters including biological soil crust (BSC) cover. We examined the effect of two more precise indicators of BSC development, chlorophyll a and exopolysaccharides (EPS), upon soil stability, which is closely inversely related to soil loss in an erosion event. To examine the relative influence of these elements of the C factor to the K factor, we conducted our investigation across eight strongly differing soils in the 0.8 million ha Grand Staircase-Escalante National Monument. We found that within every soil group, chlorophyll a was a moderate to excellent predictor of soil stability (R2 = 0.21-0.75), and consistently better than EPS. Using a simple structural equation model, we explained over half of the variance in soil stability and determined that the direct effect of chlorophyll a was 3?? more important than soil group in determining soil stability. Our results suggest that, holding the intensity of erosive forces constant, the acceleration or reduction of soil erosion in arid landscapes will primarily be an outcome of management practices. This is because the factor which is most influential to soil erosion, BSC development, is also among the most manageable, implying that water erosion in drylands has a solution. ?? 2008 Elsevier Ltd.

Elucidation of stabilizing oil-in-water Pickering emulsion with different modified maize starch-based nanoparticles.

PubMed

Ye, Fan; Miao, Ming; Jiang, Bo; Campanella, Osvaldo H; Jin, Zhengyu; Zhang, Tao

2017-08-15

The aim of present study was to study the medium-chain triacylglycerol-in-water (O/W) Pickering emulsion stabilized using different modified starch-based nanoparticles (octenylsuccinylation treated soluble starch nanoparticle, OSA-SSNP, and insoluble starch nanoparticle, ISNP). The major factors for affecting the system stability, rheological behaviour and microstructure of the emulsions were also investigated. The parameters of the O/W emulsions stabilized by OSA-SSNP or ISNP were selected as follows: 3.0% of starch nanoparticles concentration, 50% of MCT fraction and 7.0 of system pH. The rheological properties indicated that both emulsions displayed shear-thinning behaviour as a non-Newtonian fluid. For OSA-SSNP, the viscosities of the emulsion were higher than those of ISNP throughout shear rate range for the same condition. The plot of droplet size distribution for emulsion stabilized OSA-SSNP appeared as a single narrow peak, whereas a broader droplet size distribution with bimodal pattern was observed for emulsion stabilized ISNP. The microscopy results showed that both OSA-SSNP and ISNP were adsorbed at oil-water interface to form a barrier film and retard the phase separation. When emulsion was stored for 30d, no phase separation was detected for O/W emulsion, revealing high stability of emulsion stabilized by both OSA-SSNP and ISNP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measuring the emulsification dynamics and stability of self-emulsifying drug delivery systems.

PubMed

Vasconcelos, Teófilo; Marques, Sara; Sarmento, Bruno

2018-02-01

Self-emulsifying drug delivery systems (SEDDS) are one of the most promising technologies in the drug delivery field, particularly for addressing solubility and bioavailability issues of drugs. The development of these drug carriers excessively relies in visual observations and indirect determinations. The present manuscript intended to describe a method able to measure the emulsification of SEDDS, both micro and nano-emulsions, able to measure the droplet size and to evaluate the physical stability of these formulations. Additionally, a new process to evaluate the physical stability of SEDDS after emulsification was also proposed, based on a cycle of mechanical stress followed by a resting period. The use of a multiparameter continuous evaluation during the emulsification process and stability was of upmost value to understand SEDDS emulsification process. Based on this method, SEDDS were classified as fast and slow emulsifiers. Moreover, emulsification process and stabilization of emulsion was subject of several considerations regarding the composition of SEDDS as major factor that affects stability to physical stress and the use of multicomponent with different properties to develop a stable and robust SEDDS formulation. Drug loading level is herein suggested to impact droplets size of SEDDS after dispersion and SEDDS stability to stress conditions. The proposed protocol allows an online measurement of SEDDS droplet size during emulsification and a rationale selection of excipients based on its emulsification and stabilization performance. Copyright © 2017. Published by Elsevier B.V.

Peptidyl Prolyl Isomerase PIN1 Directly Binds to and Stabilizes Hypoxia-Inducible Factor-1α

PubMed Central

Han, Hyeong-jun; Kwon, Nayoung; Choi, Min-A; Jung, Kyung Oh; Piao, Juan-Yu; Ngo, Hoang Kieu Chi; Kim, Su-Jung; Kim, Do-Hee; Chung, June-Key; Cha, Young-Nam; Youn, Hyewon; Choi, Bu Young; Min, Sang-Hyun; Surh, Young-Joon

2016-01-01

Peptidyl prolyl isomerase (PIN1) regulates the functional activity of a subset of phosphoproteins through binding to phosphorylated Ser/Thr-Pro motifs and subsequently isomerization of the phosphorylated bonds. Interestingly, PIN1 is overexpressed in many types of malignancies including breast, prostate, lung and colon cancers. However, its oncogenic functions have not been fully elucidated. Here, we report that PIN1 directly interacts with hypoxia-inducible factor (HIF)-1α in human colon cancer (HCT116) cells. PIN1 binding to HIF-1α occurred in a phosphorylation-dependent manner. We also found that PIN1 interacted with HIF-1α at both exogenous and endogenous levels. Notably, PIN1 binding stabilized the HIF-1α protein, given that their levels were significantly increased under hypoxic conditions. The stabilization of HIF-1α resulted in increased transcriptional activity, consequently upregulating expression of vascular endothelial growth factor, a major contributor to angiogenesis. Silencing of PIN1 or pharmacologic inhibition of its activity abrogated the angiogenesis. By utilizing a bioluminescence imaging technique, we were able to demonstrate that PIN1 inhibition dramatically reduced the tumor volume in a subcutaneous mouse xenograft model and angiogenesis as well as hypoxia-induced transcriptional activity of HIF-1α. These results suggest that PIN1 interacting with HIF-1α is a potential cancer chemopreventive and therapeutic target. PMID:26784107

Uncovering stability mechanisms in microbial ecosystems - combining microcosm experiments, computational modelling and ecological theory in a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Worrich, Anja; König, Sara; Banitz, Thomas; Centler, Florian; Frank, Karin; Kästner, Matthias; Miltner, Anja; Thullner, Martin; Wick, Lukas

2015-04-01

Although bacterial degraders in soil are commonly exposed to fluctuating environmental conditions, the functional performance of the biodegradation processes can often be maintained by resistance and resilience mechanisms. However, there is still a gap in the mechanistic understanding of key factors contributing to the stability of such an ecosystem service. Therefore we developed an integrated approach combining microcosm experiments, simulation models and ecological theory to directly make use of the strengths of these disciplines. In a continuous interplay process, data, hypotheses, and central questions are exchanged between disciplines to initiate new experiments and models to ultimately identify buffer mechanisms and factors providing functional stability. We focus on drying and rewetting-cycles in soil ecosystems, which are a major abiotic driver for bacterial activity. Functional recovery of the system was found to depend on different spatial processes in the computational model. In particular, bacterial motility is a prerequisite for biodegradation if either bacteria or substrate are heterogeneously distributed. Hence, laboratory experiments focussing on bacterial dispersal processes were conducted and confirmed this finding also for functional resistance. Obtained results will be incorporated into the model in the next step. Overall, the combination of computational modelling and laboratory experiments identified spatial processes as the main driving force for functional stability in the considered system, and has proved a powerful methodological approach.

The effects of surfactant and electrolyte concentrations on the size of nanochitosan during storage

NASA Astrophysics Data System (ADS)

Primaningtyas, Annisa; Budhijanto, Wiratni; Fahrurrozi, Mohammad; Kusumastuti, Yuni

2017-05-01

The nano-sized particle of chitosan (nanochitosan) is a potential natural preservative agent for fresh fish and fish product preservation. Theoretically, nano-sized particles exert strong van der Waals force to each other so that the problem associated with nanochitosan is agglomeration that leads to size instability during storage. Size stability is of importance in the application of nanochitosan as an antimicrobial agent because it considerably affects the antimicrobial activity of chitosan. In this study, the formulation of nanochitosan was optimized with respect to the two major factors in colloid dispersion theory, which were the presence of surfactant and electrolyte. Polysorbate-80 was chosen as the representative of food grade surfactant while NaCl was used as the electrolyte. The purposes of this study were to evaluate the effect of polysorbate-80 concentration and to determine the effect of NaCl ions on the particle size of nanochitosan for at least one month storage period. Data were analyzed using Analysis of Variance (ANOVA) to identify the factors significantly affect the size stability. The dynamics of particle size distribution during storage was measured by Particle Size Analyzer (PSA). The result showed that surfactant did not significantly affect the particle size stability. On the other hand, the addition of electrolyte into the colloidal dispersion of nanochitosan consistently stabilized and also narrowed the particle size distribution during storage in the range of 175-391 nm.

Implications of low great toe pressures in clinical practice.

PubMed

Varatharajan, Nandanan; Pillay, Sugendran; Hitos, Kerry; Fletcher, John P

2006-04-01

The aim of this study was to observe the outcome of patients with a great toe pressure (GTP) reading of less than 40 mmHg. Between 2002 and 2004, of 4,714 patients assessed in the Westmead Vascular Laboratory, 365 (7.7%) had GTP measurements for assessment of possible critical limb ischaemia. There were 56 limbs in 40 patients with a GTP measurement of less than 40 mmHg, and this group was studied to assess outcome factors of death, requirement for major or minor amputation, arterial reconstructive surgery, clinical stability, or documented improvement from the initial assessment. Patients requiring a major amputation had an average GTP of 13 mmHg and a toe brachial index (TBI) of 0.08, whereas those not undergoing a major amputation had an average GTP of 23.6 mmHg and TBI of 0.15. This association was weaker when an initial single evaluation was used as opposed to two or more serial assessments. Patients with and without a major amputation had an average ankle brachial index of 0.16 and 0.53, respectively. Diabetes mellitus requiring insulin and cerebrovascular disease were risk factors for major amputations. Low GTP was associated with a greater risk of major amputations. Two or more serial assessments were found to be of greater value than an initial single assessment.

Women and Men in Sport Performance: The Gender Gap has not Evolved since 1983.

PubMed

Thibault, Valérie; Guillaume, Marion; Berthelot, Geoffroy; Helou, Nour El; Schaal, Karine; Quinquis, Laurent; Nassif, Hala; Tafflet, Muriel; Escolano, Sylvie; Hermine, Olivier; Toussaint, Jean-François

2010-01-01

Sex is a major factor influencing best performances and world records. Here the evolution of the difference between men and women's best performances is characterized through the analysis of 82 quantifiable events since the beginning of the Olympic era. For each event in swimming, athletics, track cycling, weightlifting and speed skating the gender gap is fitted to compare male and female records. It is also studied through the best performance of the top 10 performers in each gender for swimming and athletics. A stabilization of the gender gap in world records is observed after 1983, at a mean difference of 10.0% ± 2.94 between men and women for all events. The gender gap ranges from 5.5% (800-m freestyle, swimming) to 18.8% (long jump). The mean gap is 10.7% for running performances, 17.5% for jumps, 8.9% for swimming races, 7.0% for speed skating and 8.7% in cycling. The top ten performers' analysis reveals a similar gender gap trend with a stabilization in 1982 at 11.7%, despite the large growth in participation of women from eastern and western countries, that coincided with later- published evidence of state-institutionalized or individual doping. These results suggest that women will not run, jump, swim or ride as fast as men. Key pointsSex is a major factor influencing best performances and world records.A stabilization of the gender gap in world records is observed after 1983, at a mean difference of 10.0% ± 2.94 between men and women for all events.The gender gap ranges from 5.5% (800-m freestyle, swimming) to 36.8% (weight lifting).The top ten performers' analysis reveals a similar gender gap trend with a stabilization in 1982 at 11.7%.Results suggest that women will not run, jump, swim or ride as fast as men.

Women and Men in Sport Performance: The Gender Gap has not Evolved since 1983

PubMed Central

Thibault, Valérie; Guillaume, Marion; Berthelot, Geoffroy; Helou, Nour El; Schaal, Karine; Quinquis, Laurent; Nassif, Hala; Tafflet, Muriel; Escolano, Sylvie; Hermine, Olivier; Toussaint, Jean-François.

2010-01-01

Sex is a major factor influencing best performances and world records. Here the evolution of the difference between men and women’s best performances is characterized through the analysis of 82 quantifiable events since the beginning of the Olympic era. For each event in swimming, athletics, track cycling, weightlifting and speed skating the gender gap is fitted to compare male and female records. It is also studied through the best performance of the top 10 performers in each gender for swimming and athletics. A stabilization of the gender gap in world records is observed after 1983, at a mean difference of 10.0% ± 2.94 between men and women for all events. The gender gap ranges from 5.5% (800-m freestyle, swimming) to 18.8% (long jump). The mean gap is 10.7% for running performances, 17.5% for jumps, 8.9% for swimming races, 7.0% for speed skating and 8.7% in cycling. The top ten performers’ analysis reveals a similar gender gap trend with a stabilization in 1982 at 11.7%, despite the large growth in participation of women from eastern and western countries, that coincided with later- published evidence of state-institutionalized or individual doping. These results suggest that women will not run, jump, swim or ride as fast as men. Key points Sex is a major factor influencing best performances and world records. A stabilization of the gender gap in world records is observed after 1983, at a mean difference of 10.0% ± 2.94 between men and women for all events. The gender gap ranges from 5.5% (800-m freestyle, swimming) to 36.8% (weight lifting). The top ten performers’ analysis reveals a similar gender gap trend with a stabilization in 1982 at 11.7%. Results suggest that women will not run, jump, swim or ride as fast as men. PMID:24149688

Factors Associated With Antidepressant Dosing in Asia: Findings From the Research on Asian Psychotropic Prescription Study.

PubMed

Rajaratnam, Kamini; Xiang, Yu-Tao; Tripathi, Adarsh; Chiu, Helen Fung Kum; Si, Tian-Mei; Chee, Kok-Yoon; Avasthi, Ajit; Grover, Sandeep; Chong, Mian-Yoon; Kuga, Hironori; Kanba, Shigenobu; He, Yan-Ling; Lee, Min-Soo; Yang, Shu-Yu; Udomratn, Pichet; Kallivayalil, Roy Abraham; Tanra, Andi J; Maramis, Margarita; Shen, Winston Wu-Dien; Sartorius, Norman; Kua, Ee-Heok; Tan, Chay-Hoon; Mahendran, Rathi; Shinfuku, Naotaka; Sum, Min Yi; Baldessarini, Ross J; Sim, Kang

2016-12-01

In this study, we sought to examine factors associated with dosing of antidepressants (ADs) in Asia. Based on reported data and clinical experience, we hypothesized that doses of ADs would be associated with demographic and clinical factors and would increase over time. This cross-sectional, pharmacoepidemiological study analyzed data collected within the Research Study on Asian Psychotropic Prescription Pattern for Antidepressants from 4164 participants in 10 Asian countries, using univariate and multivariate methods. The AD doses varied by twofold among countries (highest in PR China and RO Korea, lowest in Singapore and Indonesia), and averaged 124 (120-129) mg/d imipramine-equivalents. Average daily doses increased by 12% between 2004 and 2013. Doses were significantly higher among hospitalized patients and ranked by diagnosis: major depression > anxiety disorders > bipolar disorder, but were not associated with private/public or psychiatric/general-medical settings, nor with age, sex, or cotreatment with a mood stabilizer. In multivariate modeling, AD-dose remained significantly associated with major depressive disorder and being hospitalized. Doses of ADs have increased somewhat in Asia and were higher when used for major depression or anxiety disorders than for bipolar depression and for hospitalized psychiatric patients.

Hormonal and metabolic regulation of source-sink relations under salinity and drought: from plant survival to crop yield stability.

PubMed

Albacete, Alfonso A; Martínez-Andújar, Cristina; Pérez-Alfocea, Francisco

2014-01-01

Securing food production for the growing population will require closing the gap between potential crop productivity under optimal conditions and the yield captured by farmers under a changing environment, which is termed agronomical stability. Drought and salinity are major environmental factors contributing to the yield gap ultimately by inducing premature senescence in the photosynthetic source tissues of the plant and by reducing the number and growth of the harvestable sink organs by affecting the transport and use of assimilates between and within them. However, the changes in source-sink relations induced by stress also include adaptive changes in the reallocation of photoassimilates that influence crop productivity, ranging from plant survival to yield stability. While the massive utilization of -omic technologies in model plants is discovering hundreds of genes with potential impacts in alleviating short-term applied drought and salinity stress (usually measured as plant survival), only in relatively few cases has an effect on crop yield stability been proven. However, achieving the former does not necessarily imply the latter. Plant survival only requires water status conservation and delayed leaf senescence (thus maintaining source activity) that is usually accompanied by growth inhibition. However, yield stability will additionally require the maintenance or increase in sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves and to delayed stress-induced leaf senescence. This review emphasizes the role of several metabolic and hormonal factors influencing not only the source strength, but especially the sink activity and their inter-relations, and their potential to improve yield stability under drought and salinity stresses. © 2013.

Development of LRFD resistance factors for mechanically stabilized earth (MSE) walls.

DOT National Transportation Integrated Search

2013-12-01

Over 100 centrifuge tests were conducted to assess Load and Resistance Factor : Design (LRFD) resistance factors for external stability of Mechanically Stabilized Earth (MSE) walls : founded on granular soils. In the case of sliding stability, the te...

The Sources Of Protracted Conflict In The Western Sahara

DTIC Science & Technology

2016-03-01

potentially derail U.S. stability efforts in the region). A. MAJOR RESEARCH QUESTION The research asks, what are the factors or dynamics that have stalled ...one billion dollars annually.31U.S. investments in Morocco have nearly doubled since the enforcement of the U.S.–Moroccan free -trade agreement (the...only American free trade agreement in Africa), which provides U.S. investors with unparalleled access to African markets.32 The Western Sahara

Content and Color Stability of Anthocyanins Isolated from Schisandra chinensis Fruit

PubMed Central

Ma, Chunhui; Yang, Lei; Yang, Fengjian; Wang, Wenjie; Zhao, Chunjian; Zu, Yuangang

2012-01-01

In this work, a multivariate study based on Box-Behnken Design was used to evaluate the influence of three major variables affecting the performance of the extraction process of Schisandra chinensis anthocyanins. The optimum parameters were 5.5 h extraction time; 1:19 solid-liquid ratio and 260 r/min stirring rate, respectively. The extraction yield of anthocyanins was 29.06 mg/g under the optimum conditions. Moreover, many factors on the impact of heating, ultrasound, microwave treatment and ultraviolet irradiation on content and color stability of anthocyanins from Schisandra chinensis fruit were investigated. The results show that thermal degradation reaction of anthocyanins complies with the first order reaction kinetics, and the correlation coefficient is greater than 0.9950 at 40–80 °C. Ultrasound and microwave treatment has little effect on the stability of anthocyanins, and the extraction time of ultrasound and microwave should be no more than 60 min and 5 min, respectively. The anthocyanins degradation effect of UVC ultraviolet radiation is greater than UVA and UVB; after 9 h ultraviolet radiation, the anthocyanins content degradation of UVC is 23.9 ± 0.7%, and the ΔE* was changed from 62.81 to 76.52 ± 2.3. Through LC-MS analysis, the major composition of Schisandra chinensis anthocyanins was cyanidin-3-O-xylosylrutinoside. PMID:23203065

Regulation of Nur77 protein turnover through acetylation and deacetylation induced by p300 and HDAC1.

PubMed

Kang, Shin-Ae; Na, Hyelin; Kang, Hyun-Jin; Kim, Sung-Hye; Lee, Min-Ho; Lee, Mi-Ock

2010-09-15

Although the roles of Nur77, an orphan member of the nuclear hormone receptor superfamily, in the control of cellular proliferation, apoptosis, inflammation, and glucose metabolism, are well recognized, the molecular mechanism regulating the activity and expression of Nur77 is not fully understood. Acetylation of transcription factors has emerged recently as a major post-translational modification that regulates protein stability and transcriptional activity. Here, we examined whether Nur77 is acetylated, and we characterized potential associated factors. First, Nur77 was found to be an acetylated protein when examined by immunoprecipitation and western blotting using acetyl protein-specific antibodies. Second, expression of p300, which possesses histone acetyltransferase activity, enhanced the acetylation and protein stability of Nur77. Treatment with a histone deacetylase (HDAC) inhibitor, trichostatin A, also increased Nur77 acetylation. Among the several types of HDACs, HDAC1 was found as the major enzyme affecting protein level of Nur77. HDAC1 decreased the acetylation level, protein level, and transcriptional activity of Nur77. Interestingly, overexpression of Nur77 induced expression of both p300 and HDAC1. Finally, the expression of Nur77 increased along with that of p300, but decreased with induction of HDAC1 after treatment with epithelial growth factor, nerve growth factor, or 6-mercaptopurine, suggesting that the self-control of the acetylation status contributes to the transient induction of Nur77 protein. Taken together, these results demonstrate that acetylation of Nur77 is modulated by p300 and HDAC1, and suggest that acetylation is an important post-translational modification for the rapid turnover of Nur77 protein. Copyright 2010 Elsevier Inc. All rights reserved.

Effect of temperature and sunlight on the stability of human adenoviruses and MS2 as fecal contaminants on fresh produce surfaces.

PubMed

Carratalà, Anna; Rodriguez-Manzano, Jesús; Hundesa, Ayalkibet; Rusiñol, Marta; Fresno, Sandra; Cook, Nigel; Girones, Rosina

2013-06-17

Determining the stability, or persistence in an infectious state, of foodborne viral pathogens attached to surfaces of soft fruits and salad vegetables is essential to underpin risk assessment studies in food safety. Here, we evaluate the effect of temperature and sunlight on the stability of infectious human adenoviruses type 2 and MS2 bacteriophages on lettuce and strawberry surfaces as representative fresh products. Human adenoviruses have been selected because of their double role as viral pathogens and viral indicators of human fecal contamination. Stability assays were performed with artificially contaminated fresh samples kept in the dark or under sunlight exposure at 4 and 30°C over 24h. The results indicate that temperature is the major factor affecting HAdV stability in fresh produce surfaces, effecting decay between 3 and 4 log after 24h at 30°C. The inactivation times to achieve a reduction between 1 and 4-log are calculated for each experimental condition. This work provides useful information to be considered for improving food safety regarding the transmission of foodborne viruses through supply chains. Copyright © 2013 Elsevier B.V. All rights reserved.

Angiogenic therapy for cardiac repair based on protein delivery systems.

PubMed

Formiga, F R; Tamayo, E; Simón-Yarza, T; Pelacho, B; Prósper, F; Blanco-Prieto, M J

2012-05-01

Cardiovascular diseases remain the first cause of morbidity and mortality in the developed countries and are a major problem not only in the western nations but also in developing countries. Current standard approaches for treating patients with ischemic heart disease include angioplasty or bypass surgery. However, a large number of patients cannot be treated using these procedures. Novel curative approaches under investigation include gene, cell, and protein therapy. This review focuses on potential growth factors for cardiac repair. The role of these growth factors in the angiogenic process and the therapeutic implications are reviewed. Issues including aspects of growth factor delivery are presented in relation to protein stability, dosage, routes, and safety matters. Finally, different approaches for controlled growth factor delivery are discussed as novel protein delivery platforms for cardiac regeneration.

Amazonian freshwater habitats experiencing environmental and socioeconomic threats affecting subsistence fisheries.

PubMed

Alho, Cleber J R; Reis, Roberto E; Aquino, Pedro P U

2015-09-01

Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon's aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study's objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.

Line-of-sight pointing accuracy/stability analysis and computer simulation for small spacecraft

NASA Astrophysics Data System (ADS)

Algrain, Marcelo C.; Powers, Richard M.

1996-06-01

This paper presents a case study where a comprehensive computer simulation is developed to determine the driving factors contributing to spacecraft pointing accuracy and stability. The simulation is implemented using XMATH/SystemBuild software from Integrated Systems, Inc. The paper is written in a tutorial manner and models for major system components are described. Among them are spacecraft bus, attitude controller, reaction wheel assembly, star-tracker unit, inertial reference unit, and gyro drift estimators (Kalman filter). THe predicted spacecraft performance is analyzed for a variety of input commands and system disturbances. The primary deterministic inputs are desired attitude angles and rate setpoints. The stochastic inputs include random torque disturbances acting on the spacecraft, random gyro bias noise, gyro random walk, and star-tracker noise. These inputs are varied over a wide range to determine their effects on pointing accuracy and stability. The results are presented in the form of trade-off curves designed to facilitate the proper selection of subsystems so that overall spacecraft pointing accuracy and stability requirements are met.

[Study on the related factors of suicidal ideation in college undergraduates].

PubMed

Gao, Hong-sheng; Qu, Cheng-yi; Miao, Mao-hua

2003-09-01

To evaluate psychosocial factors and patterns on suicidal ideation of the undergraduates in Shanxi province. Four thousand eight hundred and eighty-two undergraduates in Shanxi province were investigated with multistage stratified random clustered samples. Factors associated with suicidal ideation were analyzed with logistic regression and Path analysis by scores of Beck Scale for Suicide Ideation (BSSI), Suicide Attitude Questionnaire (QSA), Adolescent Self-Rate Life Events Check List (ASLEC), DSQ, Social Support Rating Scale, SCL-90, Simple Coping Modes Questionnaire and EPQ. Tendency of psychological disorder was the major factor. Negative life events did not directly affect suicidal ideation, but personality did directly or indirectly affect suicidal ideation through coping and defensive response. Personality played a stabilized fundamental role while life events were minor but "triggering" agents. Mental disturbance disposition seemed to be the principal factor related to suicidal ideation. Above three factors were intergraded and resulted in suicidal ideation in chorus.

A Qualitative Investigation of Return to Sport After Arthroscopic Bankart Repair: Beyond Stability.

PubMed

Tjong, Vehniah K; Devitt, Brian M; Murnaghan, M Lucas; Ogilvie-Harris, Darrell J; Theodoropoulos, John S

2015-08-01

Arthroscopic shoulder stabilization is known to have excellent functional results, but many patients do not return to their preinjury level of sport, with return to play rates reported between 48% and 100% despite good outcome scores. To understand specific subjective psychosocial factors influencing a patient's decision to return to sport after arthroscopic shoulder stabilization. Case series; Level of evidence, 4. Semistructured qualitative interviews were conducted with patients aged 18 to 40 years who had undergone primary arthroscopic shoulder stabilization and had a minimum 2-year follow-up. All patients participated in sport before surgery without any further revision operations or shoulder injuries. Qualitative data analysis was performed in accordance with the Strauss and Corbin theory to derive codes, categories, and themes. Preinjury and current sport participation was defined by type, level of competition, and the Brophy/Marx shoulder activity score. Patient-reported pain and shoulder function were also obtained. A total of 25 patients were interviewed, revealing that fear of reinjury, shifts in priority, mood, social support, and self-motivation were found to greatly influence the decision to return to sport both in patients who had and had not returned to their preinjury level of play. Patients also described fear of sporting incompetence, self-awareness issues, recommendations from physical therapists, and degree of confidence as less common considerations affecting their return to sport. In spite of excellent functional outcomes, extrinsic and intrinsic factors such as competing interests, kinesiophobia, age, and internal stressors and motivators can have a major effect on a patient's decision to return to sport after arthroscopic shoulder stabilization. The qualitative methods used in this study provide a unique patient-derived perspective into postoperative recovery and highlight the necessity to recognize and address subjective and psychosocial factors rather than objective functional outcome scores alone as contributing to a patient's decision to return to play. © 2015 The Author(s).

Hydrophobic environment is a key factor for the stability of thermophilic proteins.

PubMed

Gromiha, M Michael; Pathak, Manish C; Saraboji, Kadhirvel; Ortlund, Eric A; Gaucher, Eric A

2013-04-01

The stability of thermophilic proteins has been viewed from different perspectives and there is yet no unified principle to understand this stability. It would be valuable to reveal the most important interactions for designing thermostable proteins for such applications as industrial protein engineering. In this work, we have systematically analyzed the importance of various interactions by computing different parameters such as surrounding hydrophobicity, inter-residue interactions, ion-pairs and hydrogen bonds. The importance of each interaction has been determined by its predicted relative contribution in thermophiles versus the same contribution in mesophilic homologues based on a dataset of 373 protein families. We predict that hydrophobic environment is the major factor for the stability of thermophilic proteins and found that 80% of thermophilic proteins analyzed showed higher hydrophobicity than their mesophilic counterparts. Ion pairs, hydrogen bonds, and interaction energy are also important and favored in 68%, 50%, and 62% of thermophilic proteins, respectively. Interestingly, thermophilic proteins with decreased hydrophobic environments display a greater number of hydrogen bonds and/or ion pairs. The systematic elimination of mesophilic proteins based on surrounding hydrophobicity, interaction energy, and ion pairs/hydrogen bonds, led to correctly identifying 95% of the thermophilic proteins in our analyses. Our analysis was also applied to another, more refined set of 102 thermophilic-mesophilic pairs, which again identified hydrophobicity as a dominant property in 71% of the thermophilic proteins. Further, the notion of surrounding hydrophobicity, which characterizes the hydrophobic behavior of residues in a protein environment, has been applied to the three-dimensional structures of elongation factor-Tu proteins and we found that the thermophilic proteins are enriched with a hydrophobic environment. The results obtained in this work highlight the importance of hydrophobicity as the dominating characteristic in the stability of thermophilic proteins, and we anticipate this will be useful in our attempts to engineering thermostable proteins. Copyright © 2013 Wiley Periodicals, Inc.

Using Trait-State Models to Evaluate the Longitudinal Consistency of Global Self-Esteem From Adolescence to Adulthood.

PubMed

Donnellan, M Brent; Kenny, David A; Trzesniewski, Kali H; Lucas, Richard E; Conger, Rand D

2012-12-01

The present research used a latent variable trait-state model to evaluate the longitudinal consistency of self-esteem during the transition from adolescence to adulthood. Analyses were based on ten administrations of the Rosenberg Self-Esteem scale (Rosenberg, 1965) spanning the ages of approximately 13 to 32 for a sample of 451 participants. Results indicated that a completely stable trait factor and an autoregressive trait factor accounted for the majority of the variance in latent self-esteem assessments, whereas state factors accounted for about 16% of the variance in repeated assessments of latent self-esteem. The stability of individual differences in self-esteem increased with age consistent with the cumulative continuity principle of personality development.

Using Trait-State Models to Evaluate the Longitudinal Consistency of Global Self-Esteem From Adolescence to Adulthood

PubMed Central

Donnellan, M. Brent; Kenny, David A.; Trzesniewski, Kali H.; Lucas, Richard E.; Conger, Rand D.

2012-01-01

The present research used a latent variable trait-state model to evaluate the longitudinal consistency of self-esteem during the transition from adolescence to adulthood. Analyses were based on ten administrations of the Rosenberg Self-Esteem scale (Rosenberg, 1965) spanning the ages of approximately 13 to 32 for a sample of 451 participants. Results indicated that a completely stable trait factor and an autoregressive trait factor accounted for the majority of the variance in latent self-esteem assessments, whereas state factors accounted for about 16% of the variance in repeated assessments of latent self-esteem. The stability of individual differences in self-esteem increased with age consistent with the cumulative continuity principle of personality development. PMID:23180899

Life-long stability of neurons: a century of research on neurogenesis, neuronal death and neuron quantification in adult CNS.

PubMed

Turlejski, Kris; Djavadian, Ruzanna

2002-01-01

In this chapter we provide an extensive review of 100 years of research on the stability of neurons in the mammalian brain, with special emphasis on humans. Although Cajal formulated the Neuronal Doctrine, he was wrong in his beliefs that adult neurogenesis did not occur and adult neurons are dying throughout life. These two beliefs became accepted "common knowledge" and have shaped much of neuroscience research and provided much of the basis for clinical treatment of age-related brain diseases. In this review, we consider adult neurogenesis from a historical and evolutionary perspective. It is concluded, that while adult neurogenesis is a factor in the dynamics of the dentate gyrus and olfactory bulb, it is probably not a major factor during the life-span in most brain areas. Likewise, the acceptance of neuronal death as an explanation for normal age-related senility is challenged with evidence collected over the last fifty years. Much of the problem in changing this common belief of dying neurons was the inadequacies of neuronal counting methods. In this review we discuss in detail implications of recent improvements in neuronal quantification. We conclude: First, age-related neuronal atrophy is the major factor in functional deterioration of existing neurons and could be slowed down, or even reversed by various pharmacological interventions. Second, in most cases neuronal degeneration during aging is a pathology that in principle may be avoided. Third, loss of myelin and of the white matter is more frequent and important than the limited neuronal death in normal aging.

Five-factor personality traits in patients with seasonal depression: treatment effects and comparisons with bipolar patients.

PubMed

Jain, U; Blais, M A; Otto, M W; Hirshfeld, D R; Sachs, G S

1999-09-01

Increasingly, the Five Factor Model (FFM) of personality is being used to assess personality characteristics of patients with Axis I disorders. Recent study indicates that patients with the seasonal subtype of major depression (SAD) may differ meaningfully from other depressed patients. In the present study, we further examined this finding, with attention to the stability of personality characteristics across treatment. We used the NEO-FFM to assess the personality characteristics of two samples of depressed outpatients: patients with SAD and patients with bipolar disorder. Assessment was repeated in the SAD patients after light therapy. Consistent with previous research, we found elevated scores on the Openness domain in the SAD patients. SAD patients also scored significantly lower on Neuroticism and significantly higher on the Conscientiousness and Extroversion domains than patients with bipolar disorder. Scores on the Openness domain remained elevated after treatment of SAD; this occurred in the context of significant decreases in Neuroticism and increases in Extroversion scores. These results were obtained in a relatively small-sample study. Although our sample of bipolar patients were taking mood stabilizers, it is unlikely that medication effects could explain our results. Our findings are consistent with those reported by Bagby et al. (Major depression and the five-factor model of personality. J. Pers. Disord. 1995;9:224-234) and suggests that Neuroticism and Extroversion are the FFM domains most responsive to treatment for depression. Our results also suggest that elevations on the Openness domain do not change with treatment and may be an enduring characteristic of patients with SAD.

The Challenge of Declining Enrolments. Critical Emerging Problems and Recommendations for Immediate Action. Interim Report No. 2. [La Baisse des Effectifs Scolaires. Problemes Critiques et Recommandations pour une Action Immediate. Rapport Preliminaire No. 2].

ERIC Educational Resources Information Center

Jackson, Robert W. B.

This second interim report on declining enrollment in Ontario identifies the major implications of the several factors associated with declining enrollments and makes recommendations for immediate action to contribute to the stability of the system while preparing and initiating long-term policies. The first part of the report deals with…

Stabilizing platinum in phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Remick, R. J.

1982-01-01

Platinum sintering on phosphoric acid fuel cell cathodes is discussed. The cathode of the phosphoric acid fuel cell uses a high surface area platinum catalyst dispersed on a conductive carbon support to minimize both cathode polarization and fabrication costs. During operation, however, the active surface area of these electrodes decreases, which in turn leads to decreased cell performance. This loss of active surface area is a major factor in the degradation of fuel cell performance over time.

Environmental Barrier Coatings for Ceramics and Ceramic Composites

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis; Eldridge, Jeffrey; Robinson, R. Craig; Bansal, Narottam

2004-01-01

One key factor that limits the performance of current gas turbine engines is the temperature capability of hot section structural components. Silicon-based ceramics, such as SiC/SiC composites and monolithic Si3N4, are leading candidates to replace superalloy hot section components in the next generation gas turbine engines due to their excellent high temperature properties. A major stumbling block to realizing Si-based ceramic hot section components is the recession of Si-based ceramics in combustion environments due to the volatilization of silica scale by water vapor. An external environmental barrier coating (EBC) is the most promising approach to preventing the recession. Current EBCs are based on silicon, mullite (3A12O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit the durability and temperature capability of current EBCs. Research is underway to develop EBCs with longer life and enhanced temperature capability. Understanding key issues affecting the performance of current EBCs is necessary for successful development of advanced EBCs. These issues include stress, chemical compatibility, adherence, and water vapor stability. Factors that affect stress are thermal expansion mismatch, phase stability, chemical stability, elastic modulus, etc. The current understanding on these issues will be discussed.

Increased coagulation and fibrinolytic potential of solvent-detergent plasma: a comparative study between Omniplasma and fresh frozen plasma.

PubMed

van Beers, J J B C; van Egmond, L T; Wetzels, R J H; Verhezen, P W M; Beckers, E A M; van Oerle, R; Spronk, H M H; Straat, R J M H E; Henskens, Y M C

2016-07-01

In this study, differences in levels of proteins involved in coagulation and fibrinolysis were compared between fresh frozen (quarantine plasma) and Omniplasma. Furthermore, thawing conditions and plasma stability after thawing were studied. 10 Omniplasma and 10 quarantine plasma units were used to study different procoagulation, anticoagulation and fibrinolytic parameters. Analysis took place at different time-points during plasma storage at 2-6°C. At baseline, significant reduced levels of factor V, free protein S, α2-antiplasmin and tPA-induced ROTEM lysis time were observed in Omniplasma as compared to quarantine plasma. Moreover, thrombin generation, IXa-AT complex levels and factor XIa were significantly increased in Omniplasma. The majority of the parameters studied remained stable in Omniplasma 48 h after thawing, with the exception of factor VIII (decrease) and IXa-AT (increase). Our results suggest an increased coagulation potential, presumingly as a result of contact activation during the production process and also, an increased fibrinolytic potential in Omniplasma. The stability of Omniplasma, based upon the different parameters studied, is comparable to Q-plasma. A maximum post-thawing time of 48 hfor Omniplasma can be suggested. © 2016 International Society of Blood Transfusion.

Pituitary apoplexy.

PubMed

Bi, Wenya Linda; Dunn, Ian F; Laws, Edward R

2015-02-01

Pituitary apoplexy is a clinical syndrome of sudden headache and visual decline associated with acute hemorrhagic or ischemic change of an intrasellar mass, and comprises only a subset of hemorrhagic pituitary lesions. The most common presenting symptoms include headache, nausea, diminished visual acuity or visual field, ophthalmoplegia/paresis, and impaired mental status. Multiple risk factors have been reported, although the majority of cases have no identifiable precipitants. MRI is the most sensitive diagnostic modality, with specific imaging findings dependent on the timing post-hemorrhage. Early clinical suspicion is imperative to allow for corticosteroid replacement and hemodynamic stabilization when indicated. Transsphenoidal surgical decompression improves outcome in a majority of cases, although conservative management may be appropriate in select scenarios.

Bulk antimony sulfide with excellent cycle stability as next-generation anode for lithium-ion batteries

PubMed Central

Yu, Denis Y. W.; Hoster, Harry E.; Batabyal, Sudip K.

2014-01-01

Nanomaterials as anode for lithium-ion batteries (LIB) have gained widespread interest in the research community. However, scaling up and processibility are bottlenecks to further commercialization of these materials. Here, we report that bulk antimony sulfide with a size of 10–20 μm exhibits a high capacity and stable cycling of 800 mAh g−1. Mechanical and chemical stabilities of the electrodes are ensured by an optimal electrode-electrolyte system design, with a polyimide-based binder together with fluoroethylene carbonate in the electrolyte. The polyimide binder accommodates the volume expansion during alloying process and fluoroethylene carbonate suppresses the increase in charge transfer resistance of the electrodes. We observed that particle size is not a major factor affecting the charge-discharge capacities, rate capability and stability of the material. Despite the large particle size, bulk antimony sulfide shows excellent rate performance with a capacity of 580 mAh g−1 at a rate of 2000 mA g−1. PMID:24691396

A novel lipoprotein nanoparticle system for membrane proteins

PubMed Central

Frauenfeld, Jens; Löving, Robin; Armache, Jean-Paul; Sonnen, Andreas; Guettou, Fatma; Moberg, Per; Zhu, Lin; Jegerschöld, Caroline; Flayhan, Ali; Briggs, John A.G.; Garoff, Henrik; Löw, Christian; Cheng, Yifan; Nordlund, Pär

2016-01-01

Membrane proteins are of outstanding importance in biology, drug discovery and vaccination. A common limiting factor in research and applications involving membrane proteins is the ability to solubilize and stabilize membrane proteins. Although detergents represent the major means for solubilizing membrane proteins, they are often associated with protein instability and poor applicability in structural and biophysical studies. Here, we present a novel lipoprotein nanoparticle system that allows for the reconstitution of membrane proteins into a lipid environment that is stabilized by a scaffold of Saposin proteins. We showcase the applicability of the method on two purified membrane protein complexes as well as the direct solubilization and nanoparticle-incorporation of a viral membrane protein complex from the virus membrane. We also demonstrate that this lipid nanoparticle methodology facilitates high-resolution structural studies of membrane proteins in a lipid environment by single-particle electron cryo-microscopy (cryo-EM) and allows for the stabilization of the HIV-envelope glycoprotein in a functional state. PMID:26950744

Enhancing stability and efficiency of perovskite solar cells with crosslinkable silane-functionalized and doped fullerene

DOE PAGES

Bai, Yang; Dong, Qingfeng; Shao, Yuchuan; ...

2016-10-05

The instability of hybrid perovskite materials due to water and moisture arises as one major challenge to be addressed before any practical application of the demonstrated high efficiency perovskite solar cells. Here we report a facile strategy that can simultaneously enhance the stability and efficiency of p-i-n planar heterojunction-structure perovskite devices. Crosslinkable silane molecules with hydrophobic functional groups are bonded onto fullerene to make the fullerene layer highly water-resistant. Methylammonium iodide is introduced in the fullerene layer for n-doping via anion-induced electron transfer, resulting in dramatically increased conductivity over 100-fold. With crosslinkable silane-functionalized and doped fullerene electron transport layer, themore » perovskite devices deliver an efficiency of 19.5% with a high fill factor of 80.6%. Furthermore, a crosslinked silane-modified fullerene layer also enhances the water and moisture stability of the non-sealed perovskite devices by retaining nearly 90% of their original efficiencies after 30 days’ exposure in an ambient environment.« less

Enhancing stability and efficiency of perovskite solar cells with crosslinkable silane-functionalized and doped fullerene

PubMed Central

Bai, Yang; Dong, Qingfeng; Shao, Yuchuan; Deng, Yehao; Wang, Qi; Shen, Liang; Wang, Dong; Wei, Wei; Huang, Jinsong

2016-01-01

The instability of hybrid perovskite materials due to water and moisture arises as one major challenge to be addressed before any practical application of the demonstrated high efficiency perovskite solar cells. Here we report a facile strategy that can simultaneously enhance the stability and efficiency of p–i–n planar heterojunction-structure perovskite devices. Crosslinkable silane molecules with hydrophobic functional groups are bonded onto fullerene to make the fullerene layer highly water-resistant. Methylammonium iodide is introduced in the fullerene layer for n-doping via anion-induced electron transfer, resulting in dramatically increased conductivity over 100-fold. With crosslinkable silane-functionalized and doped fullerene electron transport layer, the perovskite devices deliver an efficiency of 19.5% with a high fill factor of 80.6%. A crosslinked silane-modified fullerene layer also enhances the water and moisture stability of the non-sealed perovskite devices by retaining nearly 90% of their original efficiencies after 30 days' exposure in an ambient environment. PMID:27703136

DEFICIENT LIMB SUPPORT IS A MAJOR CONTRIBUTOR TO AGE-DIFFERENCES IN FALLING

PubMed Central

Pavol, Michael J.; Pai, Yi-Chung

2010-01-01

Older adults are more likely than young to fall upon a loss of balance, yet the factors responsible for this difference are not well understood. This study investigated whether age-related differences in movement stability, limb support, and reactive stepping contribute to the greater likelihood of falling among older adults. Sixty young and 41 older, safety-harnessed, healthy adults were exposed to a novel and unexpected forward slip during a sit-to-stand task. More older than young adults fell (76% vs. 30%). Falls in both age groups were related to lesser stability and lower hip height at first step touchdown, with 97.1% of slip outcomes correctly classified based on these variables. Decreases in hip height at touchdown had over 20 times greater effect on the odds of falling than equivalent decreases in stability. Three age-differences placed older adults at greater risk of falling: older adults had lower and more slowly rising hips at slip onset, they were less likely to respond to slipping with forceful limb extension, and they placed their stepping foot less posterior to their center of mass. The first two differences, each associated with deficient limb support, reduced hip ascent and increased hip descent. The third difference resulted in lesser stability at step touchdown. These results suggest that deficient limb support in normal movement patterns and in the reactive response to a perturbation is a major contributor to the high incidence of falls in older adults. Improving proactive and reactive limb support should be a focus of fall prevention efforts. PMID:16876174

Deficient limb support is a major contributor to age differences in falling.

PubMed

Pavol, Michael J; Pai, Yi-Chung

2007-01-01

Older adults are more likely than young to fall upon a loss of balance, yet the factors responsible for this difference are not well understood. This study investigated whether age-related differences in movement stability, limb support, and protective stepping contribute to the greater likelihood of falling among older adults. Sixty young and 41 older, safety-harnessed, healthy adults were exposed to a novel and unexpected forward slip during a sit-to-stand task. More older than young adults fell (76% vs. 30%). Falls in both age groups were related to lesser stability and lower hip height at first step touchdown, with 97.1% of slip outcomes correctly classified based on these variables. Decreases in hip height at touchdown had over 20 times greater effect on the odds of falling than equivalent decreases in stability. Three age differences placed older adults at greater risk of falling: older adults had lower and more slowly rising hips at slip onset, they were less likely to respond to slipping with ample limb support, and they placed their stepping foot less posterior to their center of mass. The first two differences, each associated with deficient limb support, reduced hip ascent and increased hip descent. The third difference resulted in lesser stability at step touchdown. These results suggest that deficient limb support in normal movement patterns and in the reactive response to a perturbation is a major contributor to the high incidence of falls in older adults. Improving proactive and reactive limb support should be a focus of fall prevention efforts.

Composting technology in waste stabilization: On the methods, challenges and future prospects.

PubMed

Onwosi, Chukwudi O; Igbokwe, Victor C; Odimba, Joyce N; Eke, Ifeanyichukwu E; Nwankwoala, Mary O; Iroh, Ikemdinachi N; Ezeogu, Lewis I

2017-04-01

Composting technology has become invaluable in stabilization of municipal waste due to its environmental compatibility. In this review, different types of composting methods reportedly applied in waste management were explored. Further to that, the major factors such as temperature, pH, C/N ratio, moisture, particle size that have been considered relevant in the monitoring of the composting process were elucidated. Relevant strategies to improve and optimize process effectiveness were also addressed. However, during composting, some challenges such as leachate generation, gas emission and lack of uniformity in assessing maturity indices are imminent. Here in, these challenges were properly addressed and some strategies towards ameliorating them were proffered. Finally, we highlighted some recent technologies that could improve composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Editorial Commentary: Evaluating the Epidemiology of Shoulder Stabilization Surgery: An Opinion on Causation.

PubMed

Nelson, Bradley

2018-03-01

Epidemiology originates from the Greek words "epi" meaning upon and "demos" meaning people. Hence, epidemiology is the study of what is "upon the people" or the analysis of the patterns of disease in a defined population. Epidemiological studies are important in defining "at-risk" patient populations so research can be directed toward these groups. It is important to understand that epidemiology does not determine causation. However, it is reasonable for clinicians (me) to opine on the reasons for these epidemiological trends. I believe that the major factors responsible for the changing incidence in shoulder stabilization are the use of the arthroscope and the surgical management of the first time dislocator. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Stability analysis of rockmass using a hydrogeologic model of groundwater flow at an underground limestone mine in Korea

NASA Astrophysics Data System (ADS)

Baek, H.; Kim, D.; Kim, G.; Kim, D.; Cheong, S.

2017-12-01

The safety and environmental issues should be addressed for sustainable mining operations. One of the key factors is the groundwater flow into underground mine workings, which will affect the overall workability and efficiency of the mining operation. Prediction of the groundwater inflow requires a detailed knowledge of the geologic conditions, including the presence of major faults and other geologic structures at the mine site. The hydrologic boundaries and depth of the phreatic surface of the mine area, as well as other relevant properties of the rockmass, are also provided. The stability of underground structures, in terms of the maximum stresses and deformations within the rockmass, can be analyzed using either the total stress or the effective stress approaches. Both the dried and saturated conditions should be considered with appropriate safety factors, as the distribution of the water pressure within the rockmass resulted from the groundwater flow directly affects the stability. In some cases, the rockmass rating systems such as the RMR and Q-systems are also applied. Various numerical codes have been used to construct the hydrogeologic models of mine sites, and the MINEDW by Itasca is one of those groundwater flow model codes developed to simulate groundwater flow related to mining. In this study, with a 3D hydrogeologic model constructed using the MINEDW for an underground limestone mine, the rate of mine water inflow and the porewater pressure were estimated. The stability of mine pillars and adits was analyzed adopting the porewater pressure and effective stress developed in the rockmass. The results were also compared with those from other 2D stability analysis procedures.

Stabilization and robustness of non-linear unity-feedback system - Factorization approach

NASA Technical Reports Server (NTRS)

Desoer, C. A.; Kabuli, M. G.

1988-01-01

The paper is a self-contained discussion of a right factorization approach in the stability analysis of the nonlinear continuous-time or discrete-time, time-invariant or time-varying, well-posed unity-feedback system S1(P, C). It is shown that a well-posed stable feedback system S1(P, C) implies that P and C have right factorizations. In the case where C is stable, P has a normalized right-coprime factorization. The factorization approach is used in stabilization and simultaneous stabilization results.

The conformational flexibility of the carboxy terminal residues 105–114 is a key modulator of the catalytic activity and stability of Macrophage Migration Inhibitory Factor (MIF)†

PubMed Central

El-Turk, Farah; Cascella, Michele; Ouertatani-Sakouhi, Hajer; Narayanan, Raghavendran Lakshmi; Leng, Lin; Bucala, Richard; Hweckstetter, Markus; Rothlisberger, Ursula; Lashuel, Hilal A.

2013-01-01

Macrophage migration inhibitory factor (MIF) is a multifunctional protein and a major mediator of innate immunity. Although X-ray crystallography revealed that MIF exists as a homotrimer, its oligomerization state in vivo as well as the factors governing its oligomerization and stability remain poorly understood. The C-terminal region of MIF is highly conserved and participates in several intramolecular interactions that suggest a role in modulating the stability and biochemical activity of MIF. To determine the importance of these interactions, point mutations (A48P, L46A), insertions (P107) at the monomer-monomer interfaces, and C-terminal deletion (Δ110-114NSTFA and Δ105–114NVGWNNSTFA) variants were designed and their structural properties, thermodynamic stability, oligomerization state, catalytic activity and receptor binding were characterized using a battery of biophysical methods. The C-terminal deletion mutants ΔC5 huMIF1-109 and ΔC10 huMIF1-104 were enzymatically inactive and thermodynamically less stable than wild type MIF. Analytical ultracentrifugation studies demonstrate that both C-terminal mutants sediment as trimers and exhibit similar binding to CD74 as the wild type protein. Disrupting the conformation of the C-terminal region 105–114 and increasing its conformational flexibility through the insertion of a proline residue at position 107 was sufficient to reproduce the structural, biochemical and thermodynamic properties of the deletion mutants. P107 MIF forms an enzymatically inactive trimer and exhibits reduced thermodynamic stability relative to the wild type protein. To provide a rationale for the changes induced by these mutations at the molecular level, we also performed molecular dynamics simulations on these mutants in comparison to the wild type MIF. Together, our studies demonstrate that inter-subunit interactions involving the C-terminal region 105–114, including a salt-bridge interaction between Arg73 of one monomer and the carboxy terminus of a neighbouring monomer, play critical roles in modulating tertiary structure stabilization, enzymatic activity, and thermodynamic stability of MIF, but not its oligomerization state and receptor binding properties. Our results suggest that targeting the C-terminal region could provide new strategies for allosteric modulation of MIF enzymatic activity and the development of novel inhibitors of MIF tautomerase activity. PMID:18795803

Crisis Stability and Nuclear Exchange Risks on the Subcontinent: Major Trends and the Iran Factor

DTIC Science & Technology

2013-11-01

nukes/ images/PakistanChart2011.jpg>. 10 Strategic Perspectives, No. 14 Islamabad’s perceived vulnerabilities and are not aimed at the actual initiation...would face a more complicated future for its nuclear deterrent than it has ever contem- plated . At the very least, New Delhi’s rather tepid pursuit of...Wonk—23 Comments, April 18, 2012, available at <http://krepon.armscontrolwonk.com/archive/3419/ tac -nukes-in-south-asia>. 46 Pakistan’s advances with

A dual-driver model of retention and turnover in the direct care workforce.

PubMed

Mittal, Vikas; Rosen, Jules; Leana, Carrie

2009-10-01

The purpose of this study was to understand the factors associated with turnover and retention of direct care workers. We hypothesize that a dual-driver model that includes individual factors, on-the-job factors, off-the-job factors, and contextual factors can be used to distinguish between reasons for direct care workforces (DCWs) staying on the job or leaving the job. We conducted 7 focus groups with 47 participants. We identified key themes they used to describe their experiences focusing on differences between stayers (had been in the same job for at least 3 years) and leavers (had changed jobs within the past 3 years). Five major themes associated with turnover were identified as follows: (a) lack of respect, (b) inadequate management, (c) work or family conflicts, (d) difficulty of the work, and (e) job openings. Themes associated with retention were as follows: (a) being "called" to service, (b) patient advocacy, (c) personal relationships with residents, (d) religion or spirituality, (e) haven from home problems, and (f) flexibility. Themes associated with turnover were different from those associated with retention. DCW turnover and retention are complex, multifactorial issues. Efforts to stabilize the DCW must address the issues associated with retention as well as those associated with turnover. Specifically, factors that promote retention may be qualitatively different than those that prevent turnover. Treating retention and turnover as simply the obverse of each other may be misleading in addressing the underlying problem of job stability among DCWs.

Inward Rectifier Potassium Channels Control Rotor Frequency in Ventricular Fibrillation

PubMed Central

Jalife, José

2009-01-01

Summary Ventricular fibrillation (VF) is the most important cause of sudden cardiac death. While traditionally thought to result from random activation of the ventricles by multiple independent wavelets, recent evidence suggests that VF may be determined by the sustained activation of a relatively small number of reentrant sources. In addition, recent experimental data in various species as well as computer simulations have provided important clues about its ionic and molecular mechanisms, particularly in regards to the role of potassium currents in such mechanisms. The results strongly argue that the inward rectifier current, Ik1, is an important current during functional reentry because it mediates the electrotonic interactions between the unexcited core and its immediate surroundings. In addition, IK1 is a stabilizer of reentry due to its ability to shorten action potential duration and reducing conduction velocity near the center of rotation. Increased I K1 prevents wavefront-wavetail interactions and thus averts rotor destabilization and breakup. Other studies have shown that while the slow component of the delayed rectifier potassium current, IKs, does not significantly modify rotor frequency or stability, it plays a major role in post-repolarization refractoriness and wavebreak formation. Therefore, the interplay between IK1 and the rapid sodium inward current (INa) is a major factor in the control of cardiac excitability and therefore the stability and frequency of reentry while IKs is an important determinant of fibrillatory conduction. PMID:19880073

Enhanced stability of a chimeric hepatitis B core antigen virus-like-particle (HBcAg-VLP) by a C-terminal linker-hexahistidine-peptide.

PubMed

Schumacher, Jens; Bacic, Tijana; Staritzbichler, René; Daneschdar, Matin; Klamp, Thorsten; Arnold, Philipp; Jägle, Sabrina; Türeci, Özlem; Markl, Jürgen; Sahin, Ugur

2018-04-13

Virus-like-particles (VLPs) are attractive nanoparticulate scaffolds for broad applications in material/biological sciences and medicine. Prior their functionalization, specific adaptations have to be carried out. These adjustments frequently lead to disordered particles, but the particle integrity is an essential factor for the VLP suitability. Therefore, major requirements for particle stabilization exist. The objective of this study was to evaluate novel stabilizing elements for functionalized chimeric hepatitis B virus core antigen virus-like particles (HBcAg-VLP), with beneficial characteristics for vaccine development, imaging or delivery. The effects of a carboxy-terminal polyhistidine-peptide and an intradimer disulfide-bridge on the stability of preclinically approved chimeric HBcAg-VLPs were assessed. We purified recombinant chimeric HBcAg-VLPs bearing different modified C-termini and compared their physical and chemical particle stability by quantitative protein-biochemical and biophysical techniques. We observed lower chemical resistance of T = 3- compared to T = 4-VLP (triangulation number) capsids and profound impairment of accessibility of hexahistidine-peptides in assembled VLPs. Histidines attached to the C-terminus were associated with superior mechanical and/or chemical particle stability depending on the number of histidine moieties. A molecular modeling approach based on cryo-electron microscopy and biolayer interferometry revealed the underlying structural mechanism for the strengthening of the integrity of VLPs. Interactions triggering capsid stabilization occur on a highly conserved residue on the basis of HBcAg-monomers as well as on hexahistidine-peptides of adjacent monomers. This new stabilization mechanism appears to mimic an evolutionary conserved stabilization concept for hepadnavirus core proteins. These findings establish the genetically simply transferable C-terminal polyhistidine-peptide as a general stabilizing element for chimeric HBcAg-VLPs to increase their suitability.

Perioperative alendronate, risedronate, calcitonin and indomethacin treatment alters femoral stem fixation and periprosthetic bone mineral density in ovariectomized rats.

PubMed

Cankaya, Deniz; Tabak, Yalcin; Ozturk, Akif Muhtar; Gunay, Muhammed Cuneyd

2015-07-01

Many factors affect implant stability and periprosthetic bone mineral density (BMD) following total joint arthroplasty. We asked whether perioperative alendronate, risedronate, calcitonin and indomethacine administration altered (1) femoral stem shear strength and periprosthetic bone mineral density BMD in ovariectomized rats and (2) whether there were differences in the effect of these drugs. Thirty overiectomized rats were divided into five groups and implanted with intramedullary mini-cortical screws in the femur. Four groups were treated with alendronate, risedronate, salmon calcitonin and indomethacin for 4 weeks preoperatively and 8 weeks postoperatively. Although alendronate and risedronate increased the periprosthetic BMD more than calcitonin, they did not alter implant fixation compared to calcitonin. Indomethacin significantly decreased the BMD around the stem and implant stability compared to all other groups. This study showed that perioperative treatment with bisphosphonates and calcitonin improved the BMD around the stems and implant stability. Although bisphosphonates increased the BMD more than calcitonin, there was no difference in implant stability. Indomethacin markedly decreased the periprosthetic BMD and implant stability. The main clinical significance of our study was the finding about the need to strictly avoid long-term use of high-dose nonsteroidal antiinflammatory drugs for patients who have major joint arthritis and a previous history of arthroplasty.

Conduit stability effects on intensity and steadiness of explosive eruptions.

PubMed

Aravena, Álvaro; Cioni, Raffaello; de'Michieli Vitturi, Mattia; Neri, Augusto

2018-03-07

Conduit geometry affects magma ascent dynamics and, consequently, the style and evolution of volcanic eruptions. However, despite geological evidences support the occurrence of conduit widening during most volcanic eruptions, the factors controlling conduit enlargement are still unclear, and the effects of syn-eruptive variations of conduit geometry have not been investigated in depth yet. Based on numerical modeling and the application of appropriate stability criteria, we found out a strong relationship between magma rheology and conduit stability, with significant effects on eruptive dynamics. Indeed, in order to be stable, conduits feeding dacitic/rhyolitic eruptions need larger diameters respect to their phonolitic/trachytic counterparts, resulting in the higher eruption rates commonly observed in dacitic/rhyolitic explosive events. Thus, in addition to magma source conditions and viscosity-dependent efficiency for outgassing, we suggest that typical eruption rates for different magma types are also controlled by conduit stability. Results are consistent with a compilation of volcanological data and selected case studies. As stability conditions are not uniform along the conduit, widening is expected to vary in depth, and three axisymmetric geometries with depth-dependent radii were investigated. They are able to produce major modifications in eruptive parameters, suggesting that eruptive dynamics is influenced by syn-eruptive changes in conduit geometry.

Biochemical and physical factors affecting discoloration characteristics of 19 bovine muscles.

PubMed

McKenna, D R; Mies, P D; Baird, B E; Pfeiffer, K D; Ellebracht, J W; Savell, J W

2005-08-01

Steaks from muscles (n=19 from nine beef carcasses) were evaluated over the course of retail display (0-, 1-, 2-, 3-, 4- or 5-d) for objective measures of discoloration (metmyoglobin, oxymyoglobin, L*-, a*-, and b*-values), reducing ability (metmyoglobin reductase activity (MRA), resistance to induced metmyoglobin formation (RIMF), and nitric oxide metmyoglobin reducing ability (NORA)), oxygen consumption rate (OCR), oxygen penetration depth, myoglobin content, oxidative rancidity, and pH. Muscles were grouped according to objective color measures of discoloration. M. longissimus lumborum, M. longissimus thoracis, M. semitendinosus, and M. tensor fasciae latae were grouped as "high" color stability muscles, M. semimembranosus, M. rectus femoris, and M. vastus lateralis were grouped as "moderate" color stability muscles, M. trapezius, M. gluteus medius, and M. latissimus dorsi were grouped as "intermediate" color stability muscles, M. triceps brachi - long head, M. biceps femoris, M. pectoralis profundus, M. adductor, M. triceps brachi - lateral head, and M. serratus ventralis were grouped as "low" color stability muscles, and M. supraspinatus, M. infraspinatus, and M. psoas major were grouped as "very low" color stability muscles. Generally, muscles of high color stability had high RIMF, nitric oxide reducing ability, and oxygen penetration depth and possessed low OCRs, myoglobin content, and oxidative rancidity. In contrast, muscles of low color stability had high MRA, OCRs, myoglobin content, and oxidative rancidity and low RIMF, NORA, and oxygen penetration depth. Data indicate that discoloration differences between muscles are related to the amount of reducing activity relative to the OCR.

Factors affecting the stability of reverse shoulder arthroplasty: a biomechanical study.

PubMed

Clouthier, Allison L; Hetzler, Markus A; Fedorak, Graham; Bryant, J Tim; Deluzio, Kevin J; Bicknell, Ryan T

2013-04-01

Despite the success of reverse shoulder arthroplasty (RSA) in treating patients with painful pseudoparalytic shoulders, instability is a common complication and currently the factors affecting stability are not well understood. The objective of this study was to investigate a number of factors as well as the interactions between factors to determine how they affect the stability of the prosthesis. These factors included: active arm posture (abduction and abduction plane angles), loading direction, glenosphere diameter and eccentricity, and humeral socket constraint. Force required to dislocate the joint, determined using a biomechanical shoulder simulator, was used as a measure of stability. A factorial design experiment was implemented to examine the factors and interactions. Actively increasing the abduction angle by 15° leads to a 30% increase in stability and use of an inferior-offset rather than a centered glenosphere improved stability by 17%. Use of a more constrained humeral socket also increased stability; but the effect was dependent on loading direction, with a 88% improvement for superior loading, 66% for posterior, 36% for anterior, and no change for inferior loading. Abduction plane angle and glenosphere diameter had no effect on stability. Increased glenohumeral abduction and the use of an inferior-offset glenosphere were found to increase the stability of RSA. Additionally, use of a more constrained humeral socket increased stability for anterior, posterior, and superior loading. These identified factor effects have the potential to decrease the risk of dislocation following RSA. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Stability and change in personality disorders.

PubMed

Morey, Leslie C; Hopwood, Christopher J

2013-01-01

Stability is thought to be one of the major distinguishing features between personality disorders (PDs) and other forms of psychopathology. The development of more reliable PD assessments and the implementation of four major longitudinal studies on PD stability have provided critical data with which to evaluate the stability of PD features. Results from these and other studies reveal significant complexity in the interpretation of PD stability because of several issues that can impact stability estimates. Such estimates will vary as a function of the type of constructs being assessed, the type of stability being considered, the modality and reliability of the assessments being used, and the impacts of sampling. In this article, longitudinal research on PD stability is reviewed in the context of these issues. It is concluded that no single answer can be given to the question, "How stable are PDs?" and that future research and classification need to consider carefully and account for the complexity of this question.

An Exploratory Study of the Five-Factor Personality Traits Model as Predictors among Women in Science, Technology, Engineering, and Mathematics Fields at Indiana State University

NASA Astrophysics Data System (ADS)

Challa, Sowmya

The purpose of this study is to identify any trends in personality traits of students at a mid-western university along with the influence of gender, choice of STEM or non-STEM academic major, and level of education on personality traits. The chosen mid-western university is Indiana State University (ISU) located in Terre Haute, Indiana. This study investigated the personality traits of student's through administering Goldberg's (1999) International Personality Item Pool of the Big Five Broad Domains of Personality. The personality profiles of students at ISU who have taken the questionnare are summarized. The personality profiles of female students were analyzed further with special focus to identify the role of level of education and choice of major among female students. Based on the responses of the study's subjects, there are significant relationships found between gender and all of the big five personality traits. Level of education, graduate or undergraduate, had significant impact on extraversion, agreeability, concientiousness, and emotional stability. Choice of STEM and non-STEM major impacted emotional stability for subjects in general but its influence is not significant among female subjects. Choice of STEM or non-STEM major had a significant influence on the intelligence/imagination trait for both male and female subjects. Level of education did not have any significant influence on intellegence/imagination. Overall, this study found a few significant relationships between Big-Five personality traits and identified categorizations.

Stability and Change of Social Goals in Adolescence

PubMed Central

Trucco, Elisa M.; Wright, Aidan G. C.; Colder, Craig R.

2013-01-01

Objective This study provides a comprehensive analysis of continuity and change in social goals using the interpersonal circumplex (IPC) model across adolescence (ages 11 – 16). Five complementary definitions of stability were examined: structural, rank-order, absolute, individual, and ipsative. Method Data were taken from a longitudinal study of early adolescent problem behavior. Social goals were assessed during each wave with data collection occurring at three annual intervals (Wave 1, ages 10-12). A community sample of adolescents (n = 387) was recruited. Adolescents were evenly split on gender and a majority (82.7%) was White. Results Results suggest a modest increase in stability across social goals; yet, significant interindividual heterogeneity. Although levels of Agentic and Communal factors increase over time, these patterns were driven by decreases in the Submissive and Separate octants. Conclusions This offers evidence for the utility of examining lower-order facets of interpersonal dispositions as it provides a nuanced picture of adolescent personality development. Furthermore, findings suggest that change and continuity in social goals may both be relevant in this developmental period. The difficulty is accounting for trait stability as well as change, and the IPC model may be particularly useful for meeting this challenge. PMID:23998889

ERK1/2/MAPK pathway-dependent regulation of the telomeric factor TRF2

PubMed Central

Picco, Vincent; Coste, Isabelle; Giraud-Panis, Marie-Josèphe; Renno, Toufic; Gilson, Eric; Pagès, Gilles

2016-01-01

Telomere stability is a hallmark of immortalized cells, including cancer cells. While the telomere length is maintained in most cases by the telomerase, the activity of a protein complex called Shelterin is required to protect telomeres against unsuitable activation of the DNA damage response pathway. Within this complex, telomeric repeat binding factor 2 (TRF2) plays an essential role by blocking the ataxia telangiectasia-mutated protein (ATM) signaling pathway at telomeres and preventing chromosome end fusion. We showed that TRF2 was phosphorylated in vitro and in vivo on serine 323 by extracellular signal-regulated kinase (ERK1/2) in both normal and cancer cells. Moreover, TRF2 and activated ERK1/2 unexpectedly interacted in the cytoplasm of tumor cells and human tumor tissues. The expression of non-phosphorylatable forms of TRF2 in melanoma cells induced the DNA damage response, leading to growth arrest and tumor reversion. These findings revealed that the telomere stability is under direct control of one of the major pro-oncogenic signaling pathways (RAS/RAF/MEK/ERK) via TRF2 phosphorylation. PMID:27366950

E2F1 interactions with hHR23A inhibit its degradation and promote DNA repair.

PubMed

Singh, Randeep K; Dagnino, Lina

2016-05-03

Nucleotide excision repair (NER) is a major mechanism for removal of DNA lesions induced by exposure to UV radiation in the epidermis. Recognition of damaged DNA sites is the initial step in their repair, and requires multiprotein complexes that contain XPC and hHR23 proteins, or their orthologues. A variety of transcription factors are also involved in NER, including E2F1. In epidermal keratinocytes, UV exposure induces E2F1 phosphorylation, which allows it to recruit various NER factors to sites of DNA damage. However, the relationship between E2F1 and hHR23 proteins vis-à-vis NER has remained unexplored. We now show that E2F1 and hHR23 proteins can interact, and this interaction stabilizes E2F1, inhibiting its proteasomal degradation. Reciprocally, E2F1 regulates hHR23A subcellular localization, recruiting it to sites of DNA photodamage. As a result, E2F1 and hHR23A enhance DNA repair following exposure to UV radiation, contributing to genomic stability in the epidermis.

An analysis of lateral stability in power-off flight with charts for use in design

NASA Technical Reports Server (NTRS)

Zimmerman, Charles H

1937-01-01

The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated. The effects of the various governing factors upon the stability characteristics are discussed in detail. It is pointed out that much additional research is necessary both to correlate stability characteristics with riding, flying, and handling qualities and to provide suitable data for accurate estimates of those characteristics of an airplane while it is in the design stage.

A psychometric study of complaints in chronic tinnitus.

PubMed

Hiller, W; Goebel, G

1992-05-01

Dimensions of psychological complaints due to chronic and disabling tinnitus were investigated by means of the Tinnitus Questionnaire (TQ), administered to a sample of 138 tinnitus sufferers who had been admitted to a psychosomatic hospital. Factor analysis revealed that tinnitus-related patterns of emotional and cognitive distress, intrusiveness, auditory perceptual difficulties, sleep disturbances, and somatic complaints can be differentiated. Cognitive distortions and inappropriate attitudes towards the tinnitus and it's personal consequences were found to be highly intercorrelated forming a subgroup within a broader and more general distress factor. The stability of the factor solution obtained was examined by systematically varying the number of factors to be extracted. Based on the results of this method, scales are proposed for the questionnaire which can be used in clinical and scientific work to specifically assess major areas of tinnitus-related distress and their degree of severity. Implications for a further evaluation of the instrument are discussed.

Emergency department overcrowding: the impact of resource scarcity on physician job satisfaction.

PubMed

Rondeau, Kent V; Francescutti, Louis H

2005-01-01

Emergency departments in most developed countries have been experiencing significant overcrowding under a regime of severe resource constraints. Physicians in emergency departments increasingly find themselves toiling in workplaces that are characterized by diminished availability of, limited access to, and decreased stability of critical resources. Severe resource constraints have the potential to greatly weaken the overall job satisfaction of emergency physicians. This article examines the impact of hospital resource constraints on the job satisfaction of a large sample of emergency physicians in Canada. After controlling for workflow and patient characteristics and for various institutional and physician characteristics, institutional resource constraints are found to be major contributors to emergency physician job dissatisfaction. Resource factors that have the greatest impact on job satisfaction include availability of emergency room physicians, access to hospital technology and emergency beds, and stability of financial (investment) resources.

Acetylation-mediated Siah2 stabilization enhances PHD3 degradation in Helicobacter pylori-infected gastric epithelial cancer cells.

PubMed

Kokate, Shrikant Babanrao; Dixit, Pragyesh; Das, Lopamudra; Rath, Suvasmita; Roy, Arjama Dhar; Poirah, Indrajit; Chakraborty, Debashish; Rout, Niranjan; Singh, Shivaram Prasad; Bhattacharyya, Asima

2018-04-24

Gastric epithelial cells infected with Helicobacter pylori acquire highly invasive and metastatic characteristics. The seven in absentia homolog (Siah)2, an E3 ubiquitin ligase, is one of the major proteins that induces invasiveness of infected gastric epithelial cells. We find that p300-driven acetylation of Siah2 at lysine 139 residue stabilizes the molecule in infected cells, thereby substantially increasing its efficiency to degrade prolyl hydroxylase (PHD)3 in the gastric epithelium. This enhances the accumulation of an oncogenic transcription factor hypoxia-inducible factor 1α (Hif1α) in H. pylori-infected gastric cancer cells in normoxic condition and promotes invasiveness of infected cells. Increased acetylation of Siah2, Hif1α accumulation, and the absence of PHD3 in the infected human gastric metastatic cancer biopsy samples and in invasive murine gastric cancer tissues further confirm that the acetylated Siah2 (ac-Siah2)-Hif1α axis is crucial in promoting gastric cancer invasiveness. This study establishes the importance of a previously unrecognized function of ac-Siah2 in regulating invasiveness of H. pylori-infected gastric epithelial cells.-Kokate, S. B., Dixit, P., Das, L., Rath, S., Roy, A. D., Poirah, I., Chakraborty, D., Rout, N., Singh, S. P., Bhattacharyya, A. Acetylation-mediated Siah2 stabilization enhances PHD3 degradation in Helicobacter pylori-infected gastric epithelial cancer cells.

Accelerating Vaccine Formulation Development Using Design of Experiment Stability Studies.

PubMed

Ahl, Patrick L; Mensch, Christopher; Hu, Binghua; Pixley, Heidi; Zhang, Lan; Dieter, Lance; Russell, Ryann; Smith, William J; Przysiecki, Craig; Kosinski, Mike; Blue, Jeffrey T

2016-10-01

Vaccine drug product thermal stability often depends on formulation input factors and how they interact. Scientific understanding and professional experience typically allows vaccine formulators to accurately predict the thermal stability output based on formulation input factors such as pH, ionic strength, and excipients. Thermal stability predictions, however, are not enough for regulators. Stability claims must be supported by experimental data. The Quality by Design approach of Design of Experiment (DoE) is well suited to describe formulation outputs such as thermal stability in terms of formulation input factors. A DoE approach particularly at elevated temperatures that induce accelerated degradation can provide empirical understanding of how vaccine formulation input factors and interactions affect vaccine stability output performance. This is possible even when clear scientific understanding of particular formulation stability mechanisms are lacking. A DoE approach was used in an accelerated 37(°)C stability study of an aluminum adjuvant Neisseria meningitidis serogroup B vaccine. Formulation stability differences were identified after only 15 days into the study. We believe this study demonstrates the power of combining DoE methodology with accelerated stress stability studies to accelerate and improve vaccine formulation development programs particularly during the preformulation stage. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Dexamethasone enhances agonist induction of tissue factor in monocytes but not in endothelial cells.

PubMed

Bottles, K D; Morrissey, J H

1993-06-01

Stimulation of monocytic cells by inflammatory agents such as bacterial lipopolysaccharide or tumour necrosis factor-alpha leads to the rapid and transient expression of tissue factor, the major cellular initiator of the extrinsic coagulation cascade in both haemostasis and tissue inflammation. In this study we investigated whether the synthetic anti-inflammatory glucocorticoid, dexamethasone, would inhibit agonist induction of tissue factor expression in both monocytes and endothelial cells. Surprisingly, dexamethasone significantly enhanced the induction of tissue factor expression by peripheral blood mononuclear cells and an established monocytic cell line, THP-1, in response to lipopolysaccharide or tumour necrosis factor-alpha. However, unlike monocytic cells, dexamethasone did not enhance agonist induction of tissue factor in endothelial cells. Synergistic enhancement of tissue factor expression by dexamethasone was also reflected in tissue factor mRNA levels in THP-1 cells, but was not the result of improved TF mRNA stability. Synergism between bacterial lipopolysaccharide and glucocorticoid in the induction of monocyte effector function is extremely unusual and may help to explain the variable outcome of glucocorticoid treatment of septic shock.

Molecular dynamics of Middle East Respiratory Syndrome Coronavirus (MERS CoV) fusion heptad repeat trimers.

PubMed

Kandeel, Mahmoud; Al-Taher, Abdulla; Li, Huifang; Schwingenschlogl, Udo; Al-Nazawi, Mohamed

2018-08-01

Structural studies related to Middle East Respiratory Syndrome Coronavirus (MERS CoV) infection process are so limited. In this study, molecular dynamics (MD) simulations were carried out to unravel changes in the MERS CoV heptad repeat domains (HRs) and factors affecting fusion state HR stability. Results indicated that HR trimer is more rapidly stabilized, having stable system energy and lower root mean square deviations (RMSDs). While trimers were the predominant active form of CoVs HRs, monomers were also discovered in both of viral and cellular membranes. In order to find the differences between S2 monomer and trimer molecular dynamics, S2 monomer was modelled and subjected to MD simulation. In contrast to S2 trimer, S2 monomer was unstable, having high RMSDs with major drifts above 8 Å. Fluctuation of HR residue positions revealed major changes in the C-terminal of HR2 and the linker coil between HR1 and HR2 in both monomer and trimer. Hydrophobic residues at the a and d positions of HR helices stabilize the whole system, with minimal changes in RMSD. The global distance test and contact area difference scores support instability of MERS CoV S2 monomer. Analysis of HR1-HR2 inter-residue contacts and interaction energy revealed three energy scales along HR helices. Two strong interaction energies were identified at the start of the HR2 helix and at the C-terminal of HR2. The identified critical residues by MD simulation and residues at the a and d positions of HR helix were strong stabilizers of HR recognition. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stability in and correlation between factors influencing genetic quality of seed lots in seed orchard of Pinus tabuliformis Carr. over a 12-year span.

PubMed

Li, Wei; Wang, Xiaoru; Li, Yue

2011-01-01

Coniferous seed orchards require a long period from initial seed harvest to stable seed production. Differential reproductive success and asynchrony are among the main factors for orchard crops year-to-year variation in terms of parental gametic contribution and ultimately the genetic gain. It is fundamental in both making predictions about the genetic composition of the seed crop and decisions about orchard roguing and improved seed orchard establishment. In this paper, a primary Chinese pine seed orchard with 49 clones is investigated for stability, variation and correlation analysis of factors which influence genetic quality of the seed lots from initial seed harvest to the stable seed production over a 12 years span. Results indicated that the reproductive synchrony index of pollen shedding has shown to be higher than that of the strobili receptivity, and both can be drastically influenced by the ambient climate factors. Reproductive synchrony index of the clones has certain relative stability and it could be used as an indication of the seed orchard status during maturity stage; clones in the studied orchard have shown extreme differences in terms of the gametic and genetic contribution to the seed crop at the orchard's early production phase specifically when they severe as either female or male parents. Those differences are closely related to clonal sex tendency at the time of orchard's initial reproduction. Clonal gamete contribution as male and female parent often has a negative correlation. Clone utilization as pollen, seed or both pollen and seed donors should consider the role it would play in the seed crop; due to numerous factors influencing on the mating system in seed orchards, clonal genetic contribution as male parent is uncertain, and it has major influence on the genetic composition in the seed orchard during the initial reproductive and seed production phase.

Synergistic interactions of blood-borne immune cells, fibroblasts and extracellular matrix drive repair in an in vitro peri-implant wound healing model

NASA Astrophysics Data System (ADS)

Burkhardt, Melanie A.; Waser, Jasmin; Milleret, Vincent; Gerber, Isabel; Emmert, Maximilian Y.; Foolen, Jasper; Hoerstrup, Simon P.; Schlottig, Falko; Vogel, Viola

2016-02-01

Low correlations of cell culture data with clinical outcomes pose major medical challenges with costly consequences. While the majority of biomaterials are tested using in vitro cell monocultures, the importance of synergistic interactions between different cell types on paracrine signalling has recently been highlighted. In this proof-of-concept study, we asked whether the first contact of surfaces with whole human blood could steer the tissue healing response. This hypothesis was tested using alkali-treatment of rough titanium (Ti) surfaces since they have clinically been shown to improve early implant integration and stability, yet blood-free in vitro cell cultures poorly correlated with in vivo tissue healing. We show that alkali-treatment, compared to native Ti surfaces, increased blood clot thickness, including platelet adhesion. Strikingly, blood clots with entrapped blood cells in synergistic interactions with fibroblasts, but not fibroblasts alone, upregulated the secretion of major factors associated with fast healing. This includes matrix metalloproteinases (MMPs) to break down extracellular matrix and the growth factor VEGF, known for its angiogenic potential. Consequently, in vitro test platforms, which consider whole blood-implant interactions, might be superior in predicting wound healing in response to biomaterial properties.

Shoulder joint loading and posture during medicine cart pushing task.

PubMed

Xu, Xu; Lin, Jia-Hua; Boyer, Jon

2013-01-01

Excessive physical loads and awkward shoulder postures during pushing and pulling are risk factors for shoulder pain. Pushing a medicine cart is a major component of a work shift for nurses and medical assistants in hospitals and other health care facilities. A laboratory experiment was conducted to examine the effects of common factors (e.g., lane congestion, cart load stability, floor surface friction) on shoulder joint moment and shoulder elevation angle of participants during cart pushing. Participants pushed a medicine cart on straight tracks and turning around right-angle corners. Peak shoulder joint moments reached 25.1 Nm, 20.3 Nm, and 26.8 Nm for initial, transition, and turning phases of the pushing tasks, indicating that shoulder joint loading while pushing a medical cart is comparable to levels previously reported from heavy manual activities encountered in industry (e.g., garbage collection). Also, except for user experience, all other main study factors, including congestion level, cart load stability, location of transition strip, shoulder tendency, surface friction, and handedness, significantly influenced shoulder joint moment and shoulder elevation angle. The findings provide a better understanding of shoulder exposures associated with medicine cart operations and may be helpful in designing and optimizing the physical environment where medicine carts are used.

Patterns in longitudinal growth of refraction in Southern Chinese children: cluster and principal component analysis.

PubMed

Chen, Yanxian; Chang, Billy Heung Wing; Ding, Xiaohu; He, Mingguang

2016-11-22

In the present study we attempt to use hypothesis-independent analysis in investigating the patterns in refraction growth in Chinese children, and to explore the possible risk factors affecting the different components of progression, as defined by Principal Component Analysis (PCA). A total of 637 first-born twins in Guangzhou Twin Eye Study with 6-year annual visits (baseline age 7-15 years) were available in the analysis. Cluster 1 to 3 were classified after a partitioning clustering, representing stable, slow and fast progressing groups of refraction respectively. Baseline age and refraction, paternal refraction, maternal refraction and proportion of two myopic parents showed significant differences across the three groups. Three major components of progression were extracted using PCA: "Average refraction", "Acceleration" and the combination of "Myopia stabilization" and "Late onset of refraction progress". In regression models, younger children with more severe myopia were associated with larger "Acceleration". The risk factors of "Acceleration" included change of height and weight, near work, and parental myopia, while female gender, change of height and weight were associated with "Stabilization", and increased outdoor time was related to "Late onset of refraction progress". We therefore concluded that genetic and environmental risk factors have different impacts on patterns of refraction progression.

Personality dimensions measured using the Temperament and Character Inventory (TCI) and NEO-FFI on a Polish sample.

PubMed

Mikołajczyk, Elzbieta; Zietek, Joanna; Samochowiec, Agnieszka; Samochowiec, Jerzy

2008-01-01

The results of two self-administered, paper-and-pencil tests based on biosocial theory of personality have been compared simultaneously: the Temperament and Character Inventory (TCI) and NEO Five Factor Inventory (NEO-FFI). The stability of the personality dimensions was assessed across age, sex and education level samples in a group of 406 Polish adults with major mental diseases excluded by use of PRIME-MD questionnaire. Significant effects of age, sex, and education have been found while comparing personality dimensions in both temperamental (novelty seeking, NS; harm avoidance, HA; reward dependence, RD; persistence, P) and character scales (cooperativeness, C; self-transcendence, ST) in TCI. Among subscales of temperament only NS1, RD4 were stable according to concerning factors. All converted to their age and sex norms NEO-FFI dimensions were stable according to sex. Extraversion scale was changeable depending on age (p = 0.04). Neuroticism dimension was a little higher in lower educated group (p = 0.035).To sum up, it was concluded that sex- and age-specific norms for the dimensions of the Polish version of TCI are necessary considering the established significant differences. Particular personality genetic studies should account for age, sex and also educational differences in their methods of associative studies. In the exploration of personality dimensions on healthy volunteers the Polish version of NEO-FFI corresponds better than TCI to theory of stability and genetic determinants of human personality. As the study included persons with excluded major mental diseases, the sample is appropriate to provide a control group in the research of psychiatric patients using both TCI and NEO-FFI. TCI scores for persons with excluded mental disease are highly changeable depending on age, sex and education. Adjusted to sex and age scores NEO-FFI corresponded better than TCI to stability and genetic determinants of human personality.

Assessing the effects of lumbar posterior stabilization and fusion to vertebral bone density in stabilized and adjacent segments by using Hounsfield unit

PubMed Central

Öksüz, Erol; Deniz, Fatih Ersay; Demir, Osman

2017-01-01

Background Computed tomography (CT) with Hounsfield unit (HU) is being used with increasing frequency for determining bone density. Established correlations between HU and bone density have been shown in the literature. The aim of this retrospective study was to determine the bone density changes of the stabilized and adjacent segment vertebral bodies by comparing HU values before and after lumbar posterior stabilization. Methods Sixteen patients who had similar diagnosis of lumbar spondylosis and stenosis were evaluated in this study. Same surgical procedures were performed to all of the patients with L2-3-4-5 transpedicular screw fixation, fusion and L3-4 total laminectomy. Bone mineral density measurements were obtained with clinical CT. Measurements were obtained from stabilized and adjacent segment vertebral bodies. Densities of vertebral bodies were evaluated with HU before the surgeries and approximately one year after the surgeries. The preoperative HU value of each vertebra was compared with postoperative HU value of the same vertebrae by using statistical analysis. Results The HU values of vertebra in the stabilized and adjacent segments consistently decreased after the operations. There were significant differences between the preoperative HU values and the postoperative HU values of the all evaluated vertebral bodies in the stabilized and adjacent segments. Additionally first sacral vertebra HU values were found to be significantly higher than lumbar vertebra HU values in the preoperative group and postoperative group. Conclusions Decrease in the bone density of the adjacent segment vertebral bodies may be one of the major predisposing factors for adjacent segment disease (ASD). PMID:29354730

Stream Channel Stability Assessment

DOT National Transportation Integrated Search

1982-01-01

Channel instability is manifested as lateral bank erosion, progressive degradation of the streambed, or natural scour and fill of the streambed. Lateral stability is related to stream type, and four major stream types having different stability chara...

Robust motion artefact resistant circuit for calculation of Mean Arterial Pressure from pulse transit time.

PubMed

Bhattacharya, Tinish; Gupta, Ankesh; Singh, Salam ThoiThoi; Roy, Sitikantha; Prasad, Anamika

2017-07-01

Cuff-less and non-invasive methods of Blood Pressure (BP) monitoring have faced a lot of challenges like stability, noise, motion artefact and requirement for calibration. These factors are the major reasons why such devices do not get approval from the medical community easily. One such method is calculating Blood Pressure indirectly from pulse transit time (PTT) obtained from electrocardiogram (ECG) and Photoplethysmogram (PPG). In this paper we have proposed two novel analog signal conditioning circuits for ECG and PPG that increase stability, remove motion artefacts, remove the sinusoidal wavering of the ECG baseline due to respiration and provide consistent digital pulses corresponding to blood pulses/heart-beat. We have combined these two systems to obtain the PTT and then correlated it with the Mean Arterial Pressure (MAP). The aim was to perform major part of the processing in analog domain to decrease processing load over microcontroller so as to reduce cost and make it simple and robust. We have found from our experiments that the proposed circuits can calculate the Heart Rate (HR) with a maximum error of ~3.0% and MAP with a maximum error of ~2.4% at rest and ~4.6% in motion.

Enterococcus faecium Biofilm Formation: Identification of Major Autolysin AtlAEfm, Associated Acm Surface Localization, and AtlAEfm-Independent Extracellular DNA Release

PubMed Central

Paganelli, Fernanda L.; Willems, Rob J. L.; Jansen, Pamela; Hendrickx, Antoni; Zhang, Xinglin; Bonten, Marc J. M.; Leavis, Helen L.

2013-01-01

ABSTRACT Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. PMID:23592262

Inward rectifier potassium channels control rotor frequency in ventricular fibrillation.

PubMed

Jalife, José

2009-11-01

Ventricular fibrillation (VF) is the most important cause of sudden cardiac death. While traditionally thought to result from random activation of the ventricles by multiple independent wavelets, recent evidence suggests that VF may be determined by the sustained activation of a relatively small number of reentrant sources. In addition, recent experimental data in various species as well as computer simulations have provided important clues about its ionic and molecular mechanisms, particularly in regards to the role of potassium currents in such mechanisms. The results strongly argue that the inward rectifier current, I(K1,) is an important current during functional reentry because it mediates the electrotonic interactions between the unexcited core and its immediate surroundings. In addition, I(K1) is a stabilizer of reentry due to its ability to shorten action potential duration and reduce conduction velocity near the center of rotation. Increased I(K1) prevents wave front-wave tail interactions and thus averts rotor destabilization and breakup. Other studies have shown that while the slow component of the delayed rectifier potassium current I(Ks) does not significantly modify rotor frequency or stability, it plays a major role in postrepolarization refractoriness and wave break formation. Therefore, the interplay between I(K1) and the rapid sodium inward current (I(Na)) is a major factor in the control of cardiac excitability and thus the stability and frequency of reentry, while I(Ks) is an important determinant of fibrillatory conduction.

On the measurement of stability in over-time data.

PubMed

Kenny, D A; Campbell, D T

1989-06-01

In this article, autoregressive models and growth curve models are compared. Autoregressive models are useful because they allow for random change, permit scores to increase or decrease, and do not require strong assumptions about the level of measurement. Three previously presented designs for estimating stability are described: (a) time-series, (b) simplex, and (c) two-wave, one-factor methods. A two-wave, multiple-factor model also is presented, in which the variables are assumed to be caused by a set of latent variables. The factor structure does not change over time and so the synchronous relationships are temporally invariant. The factors do not cause each other and have the same stability. The parameters of the model are the factor loading structure, each variable's reliability, and the stability of the factors. We apply the model to two data sets. For eight cognitive skill variables measured at four times, the 2-year stability is estimated to be .92 and the 6-year stability is .83. For nine personality variables, the 3-year stability is .68. We speculate that for many variables there are two components: one component that changes very slowly (the trait component) and another that changes very rapidly (the state component); thus each variable is a mixture of trait and state. Circumstantial evidence supporting this view is presented.

How can periodic orbits puzzle out the coexistence of terrestrial planets with giant eccentric ones?

NASA Astrophysics Data System (ADS)

Antoniadou, K. I.; Libert, A.-S.

2017-09-01

Hitherto unprecedented detections of exoplanets have been triggered by missions and ground based telescopes. The quest of ``exo-Earths'' has become intriguing and the long-term stability of planetary orbits is a crucial factor for the biosphere to evolve. Planets in mean-motion resonances (MMRs) prompt the investigation of the dynamics in the framework of the three-body problem, where the families of stable periodic orbits constitute the backbone of stability domains in phase space. In this talk, we address the question of the possible coexistence of terrestrial planets with a giant companion on circular or eccentric orbit and explore the extent of the stability regions, when both the eccentricity of the outer giant planet and the semi-major axis of the inner terrestrial one vary, i.e. we investigate both non-resonant and resonant configurations. The families of periodic orbits in the restricted three-body problem are computed for the 3/2, 2/1, 5/2, 3/1, 4/1 and 5/1 MMRs. We then construct maps of dynamical stability (DS-maps) to identify the boundaries of the stability domains where such a coexistence is allowed. Guided by the periodic orbits, we delve into regular motion in phase space and propose the essential values of the orbital elements, in order for such configurations to survive long time spans and hence, for observations to be complemented or revised.

An introduction to the physical aspects of helicopter stability

NASA Technical Reports Server (NTRS)

Gessow, Alfred; Amer, Kenneth B

1950-01-01

In order to provide engineers interested in rotating-wing aircraft, but with no specialized training in stability theory, some understanding of the factors that influence the flying qualities of the helicopter, an explanation is made of both the static stability and the stick-fixed oscillation in hovering and forward flight in terms of fundamental physical quantities. Three significant stability factors -- static stability with angle of attack, static stability with speed, and damping due to a pitching or rolling velocity -- are explained in detail.

Effect of packaging atmospheres on storage quality characteristics of heavily marbled beef longissimus steaks.

PubMed

Yang, Xiaoyin; Zhang, Yimin; Zhu, Lixian; Han, Mingshan; Gao, Shujuan; Luo, Xin

2016-07-01

The objective of this study was to investigate the effects of modified atmosphere packaging (MAP) systems on shelf-life and quality of beef steaks with high marbling. Four packaging types were used including 80% O2 MAP (80% O2+20% CO2), 50% O2 MAP (50% O2+30% CO2+20% N2), carbon monoxide MAP (0.4% CO+30% CO2+69.6% N2) and vacuum packaging (VP). Steaks were displayed under simulated retail conditions at 4°C for 12days. Purge loss, pH, color stability, oxidative stability and microbial counts were monitored. Aerobically packaged steaks exhibited a bright-red color at the first 4days. However, discoloration and oxidation became major factors limiting their shelf-life to 8days. Compared with aerobic packaging, anaerobic packaging extended shelf-life of heavily marbled beef steaks, due to better color stability, together with lower oxidation and microbial populations. Among all packaging methods, CO-MAP had the best preservation for steaks, with more red color than other packaging types. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

PubMed

Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

2017-05-01

Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

A Comprehensive Transcriptomic and Proteomic Analysis of Hydra Head Regeneration

PubMed Central

Petersen, Hendrik O.; Höger, Stefanie K.; Looso, Mario; Lengfeld, Tobias; Kuhn, Anne; Warnken, Uwe; Nishimiya-Fujisawa, Chiemi; Schnölzer, Martina; Krüger, Marcus; Özbek, Suat; Simakov, Oleg; Holstein, Thomas W.

2015-01-01

The cnidarian freshwater polyp Hydra sp. exhibits an unparalleled regeneration capacity in the animal kingdom. Using an integrative transcriptomic and stable isotope labeling by amino acids in cell culture proteomic/phosphoproteomic approach, we studied stem cell-based regeneration in Hydra polyps. As major contributors to head regeneration, we identified diverse signaling pathways adopted for the regeneration response as well as enriched novel genes. Our global analysis reveals two distinct molecular cascades: an early injury response and a subsequent, signaling driven patterning of the regenerating tissue. A key factor of the initial injury response is a general stabilization of proteins and a net upregulation of transcripts, which is followed by a subsequent activation cascade of signaling molecules including Wnts and transforming growth factor (TGF) beta-related factors. We observed moderate overlap between the factors contributing to proteomic and transcriptomic responses suggesting a decoupled regulation between the transcriptional and translational levels. Our data also indicate that interstitial stem cells and their derivatives (e.g., neurons) have no major role in Hydra head regeneration. Remarkably, we found an enrichment of evolutionarily more recent genes in the early regeneration response, whereas conserved genes are more enriched in the late phase. In addition, genes specific to the early injury response were enriched in transposon insertions. Genetic dynamicity and taxon-specific factors might therefore play a hitherto underestimated role in Hydra regeneration. PMID:25841488

Research on the Influence Factors of Emulsion Stability of Oil-in-water Drilling Fluid

NASA Astrophysics Data System (ADS)

Li, Xiaoxu; Sun, Yuxue; Chen, Xiangming; Wang, Zengkui; Xu, Jianjun

2018-01-01

The evaluation standard of emulsion stability of oil-in-water drilling fluid is determined in this paper, based on which an evaluation analysis is conducted for the influence factors of emulsion stability, including the addition of emulsifier, addition of stabilizer, stirring speed, weighing agent, clay, etc. to gain the corresponding regularity understanding.

Aircrew-aircraft integration: A summary of US Army research programs and plans

NASA Technical Reports Server (NTRS)

Key, D. L.; Aiken, E. W.

1984-01-01

A review of selected programs which illustrate the research efforts of the U.S. Army Aeromechanics Laboratory in the area of aircrew-aircraft integration is presented. Plans for research programs to support the development of future military rotorcraft are also described. The crew of a combat helicopter must, in general, perform two major functions during the conduct of a particular mission: flightpath control and mission management. Accordingly, the research programs described are being conducted in the same two major categories: (1) flightpath control, which encompasses the areas of handling qualities, stability and control, and displays for the pilot's control of the rotorcraft's flightpath, and (2) mission management, which includes human factors and cockpit integration research topics related to performance of navigation, communication, and aircraft systems management tasks.

Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop.

PubMed

Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

2016-06-25

A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm.

High performance aluminum–cerium alloys for high-temperature applications

DOE PAGES

Sims, Zachary C.; Rios, Orlando R.; Weiss, David; ...

2017-08-01

Light-weight high-temperature alloys are important to the transportation industry where weight, cost, and operating temperature are major factors in the design of energy efficient vehicles. Aluminum alloys fill this gap economically but lack high-temperature mechanical performance. Alloying aluminum with cerium creates a highly castable alloy, compatible with traditional aluminum alloy additions, that exhibits dramatically improved high-temperature performance. These compositions display a room temperature ultimate tensile strength of 400 MPa and yield strength of 320 MPa, with 80% mechanical property retention at 240 °C. A mechanism is identified that addresses the mechanical property stability of the Al-alloys to at least 300more » °C and their microstructural stability to above 500 °C which may enable applications without the need for heat treatment. Lastly, neutron diffraction under load provides insight into the unusual mechanisms driving the mechanical strength.« less

The self-concept and conjugal loss: evidence for structural change.

PubMed

Montpetit, Mignon A; Bergeman, C S; Bisconti, Toni L

2010-08-01

The self-concept is often considered to be a personal resource that individuals may use to cope with life stressors, but little is known about how this entity might itself change in response to profound stress. The present study examines structural change in self-concept following conjugal loss in later life. Analyses were conducted on data collected from 57 widows every 4 months over the first 2 years post-loss. The first objective was to explore the adequacy of an operational definition of the self-concept as a latent construct lying at the confluence of self-esteem, perceived environmental mastery, and optimism. Because confirmatory factor analysis (CFA) supported this theoretically based conceptualization, the second objective of the study was to model stability and change in the structure of the self-concept over the 2-year study period. Results suggested that there is both stability and change in the self-system during the adjustment to major life stress.

Soybean-derived biofuels and home heating fuels.

PubMed

Mushrush, George W; Wynne, James H; Willauer, Heather D; Lloyd, Christopher L

2006-01-01

It is environmentally enticing to consider replacing or blending petroleum derived heating fuels with biofuels for many reasons. Major considerations include the soaring worldwide price of petroleum products, especially home heating oil, the toxicity of the petroleum-derived fuels and the environmental damage that leaking petroleum tanks afford. For these reasons, it has been suggested that domestic renewable energy sources be considered as replacements, or at the least, as blending stocks for home heating fuels. If recycled soy restaurant cooking oils could be employed for this purpose, this would represent an environmental advantage. Renewable plant sources of energy tend to be less toxic than their petroleum counterparts. This is an important consideration when tank leakage occurs. Home fuel oil storage tanks practically always contain some bottom water. This water environment has a pH value that factors into heating fuel stability. Therefore, the question is: would the biofuel help or exacerbate fuel stability and furnace maintenance issues?

Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil.

PubMed

Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

2015-05-05

Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using (13)C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems.

Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil

PubMed Central

Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

2015-01-01

Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using 13C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems. PMID:25944542

Cognitive factors in subjective stabilization of the visual world.

PubMed

Bridgeman, B

1981-08-01

If an eye movement signal is fed through a galvanic mirror, to move a projected image which a subject is inspecting, prominent objects in the image may seem to jiggle or jump with the the eye when the gain is just below the threshold for detecting a jump of the entire image (Brune and Lücking 1969). We have refined and extended this observation with both naive and practiced subjects, finding results which contradict all of the current theories about the mechanism of stabilization of the visual world and suggest that cognitive factors in perception important influences on the stabilization process. Using this method with a paired photocell system to detect horizontal eye movements, some subjects saw a prominent object in the display jump slightly while the rest of the scene remained stable. The task was done first with landscape slides, then repeated with Escher prints where two sets of alternating figures completely filled the image. Subjects could concentrate on one set of forms as the "figure" and the other as the "ground", and reverse the two at will. In a majority of practiced subjects and in smaller proportion of naive subjects, motion of part of the "figure" was seen regardless of which alternative set of forms constituted it. Reversibility of the effect controlled for influence of object size, brightness, etc. in inducing the selective jump. These and related observations show that cognitive or attentional variables are as important as image properties or gain alone in determining subjective stabilization of the visual world, though current theories (inflow, outflow, cancellation, etc.) consider image position to be simple variable. Another experiment showed that image movement on the retina during saccades cannot explain saccadic suppression of displacement.

JP-8+100: The development of high-thermal-stability jet fuel

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

Heneghan, S.P.; Zabarnick, S.; Ballal, D.R.

1996-09-01

Jet fuel requirements have evolved over the years as a balance of the demands placed by advanced aircraft performance (technological need), fuel cost (economic factors), and fuel availability (strategic factors). In a modern aircraft, the jet fuel not only provides the propulsive energy for flight, but also is the primary coolant for aircraft and engine subsystems. To meet the evolving challenge of improving the cooling potential of jet fuel while maintaining the current availability at a minimal price increase, the US Air Force, industry, and academia have teamed to develop an additive package for JP-8 fuels. This paper describes themore » development of an additive package for JP-8, to produce JP-8+100. This new fuel offers a 55 C increase in the bulk maximum temperature (from 325 F to 425 F) and improves the heat sink capability by 50%. Major advances made during the development JP-8 + 100 fuel include the development of several new quantitative fuel analysis tests, a free radical theory of autooxidation, adaptation of new chemistry models to computational fluid dynamics programs, and a nonparametric statistical analysis to evaluate thermal stability. Hundreds of additives were tested for effectiveness, and a package of additives was then formulated for JP-8 fuel. This package has been tested for fuel system materials compatibility and general fuel applicability. To date, the flight testing ha shown an improvement in thermal stability of JP-8 fuel. This improvement has resulted in a significant reduction in fuel-related maintenance costs and a threefold increase in mean time between fuel-related failures. In this manner, a novel high-thermal-stability jet fuel for the 21st century has been successfully developed.« less

Long-term stability and properties of zirconia ceramics for heavy duty diesel engine components

NASA Technical Reports Server (NTRS)

Larsen, D. C.; Adams, J. W.

1985-01-01

Physical, mechanical, and thermal properties of commercially available transformation-toughened zirconia are measured. Behavior is related to the material microstructure and phase assemblage. The stability of the materials is assessed after long-term exposure appropriate for diesel engine application. Properties measured included flexure strength, elastic modulus, fracture toughness, creep, thermal shock, thermal expansion, internal friction, and thermal diffusivity. Stability is assessed by measuring the residual property after 1000 hr/1000C static exposure. Additionally static fatigue and thermal fatigue testing is performed. Both yttria-stabilized and magnesia-stabilized materials are compared and contrasted. The major limitations of these materials are short term loss of properties with increasing temperature as the metastable tetragonal phase becomes more stable. Fine grain yttria-stabilized material (TZP) is higher strength and has a more stable microstructure with respect to overaging phenomena. The long-term limitation of Y-TZP is excessive creep deformation. Magnesia-stabilized PSZ has relatively poor stability at elevated temperature. Overaging, decomposition, and/or destabilization effects are observed. The major limitation of Mg-PSZ is controlling unwanted phase changes at elevated temperature.

Rainfall thresholds for the initiation of shallow landslides in the Wiśnicz Foothills region (the Flysch Carpathians Mountain, Poland)

NASA Astrophysics Data System (ADS)

Demczuk, Piotr; Zydroń, Tymoteusz; Siłuch, Marcin

2017-04-01

Determination of the magnitude of the rainfall threshold is a complex task, as it depends on the properties of the engineering-geological formations deposited on slopes and lithological conditions; it is also a resultant of the intensity and duration of precipitation. Meteorological monitoring and knowledge of the geological structure and adequate engineering tools (models of the soil and rock substrate) can greatly contribute to identification of the magnitude of rainfall that can pose a threat to slope stability. Calculation programs, which include the physical description of changes in the stress state in the soil substrate, are widely used tools for assessment of the slope stability conditions. Such programs take into account only the impact of rainfall on slope stability conditions and disregard the role of other meteorological factors. Development of a model that would be able to estimate these values is difficult; hence, this paper presents an attempt to determine the impact of precipitation on slope stability of selected shallow landslide slopes located in the area of the Wiśnicz Foothills (Outer Carpathians, Poland) using physically-based model taking into account meteorological conditions. Firstly, based on the meteorological data from 2004-2013 calculations of slope stability were performed to verify the geotechnical parameters of the soils. The calculations also yielded the range of pore pressure changes in the analysed period of 2004-2013, which simultaneously facilitated determination of extreme slope stability conditions prevailing during the growing seasons in the analysed years. Further investigations were focused on determination of changes in slope stability induced in response to 120-day long rainfalls with increasing, constant, and decreasing intensities characterised by a 1-99% probability of occurrence. For the analysis, three systems of pore pressure distribution in the slope were employed. Two of them corresponded to the maximum and minimum soil wetness values at the beginning of the growing seasons in 2004-2013 (period between late March and late July, which substantially coincides with periods of intensification of mass movements in Polish Flysch Carpathians). The analyses were performed with the calculation modules of the GeoSlope Inc. package: - Vadose/W was used to determine the impact of meteorological conditions (temperature, humidity, wind speed, precipitation) on the pore pressure distribution in the slope, - Slope/W - calculations of slope stability. The stability calculations have confirmed that the rainfall threshold values are a function of many variables, primarily the hydraulic properties of slope covers and rock substratum, temporal distribution of precipitation, and wetness conditions (degree of slope cover saturation). The major mechanism of stability failure by the analysed slopes in the Wiśnicz Foothills is the saturation of slope covers. Given this mechanism, observations of the groundwater table can be an important factor in assessment of the susceptibility of slopes to mass movements, besides meteorological observations. It also seems that slope stability calculations can be an important tool for assessment of landslide hazards. Importantly, the calculations have to take into account not only precipitation data but also other meteorological factors, which have impact on the amount of water accumulated in slope covers.

Reliability analysis of InGaN/GaN multi-quantum-well solar cells under thermal stress

NASA Astrophysics Data System (ADS)

Huang, Xuanqi; Fu, Houqiang; Chen, Hong; Lu, Zhijian; Baranowski, Izak; Montes, Jossue; Yang, Tsung-Han; Gunning, Brendan P.; Koleske, Dan; Zhao, Yuji

2017-12-01

We investigate the thermal stability of InGaN solar cells under thermal stress at elevated temperatures from 400 °C to 500 °C. High Resolution X-Ray Diffraction analysis reveals that material quality of InGaN/GaN did not degrade after thermal stress. The external quantum efficiency characteristics of solar cells were well-maintained at all temperatures, which demonstrates the thermal robustness of InGaN materials. Analysis of current density-voltage (J-V) curves shows that the degradation of conversion efficiency of solar cells is mainly caused by the decrease in open-circuit voltage (Voc), while short-circuit current (Jsc) and fill factor remain almost constant. The decrease in Voc after thermal stress is attributed to the compromised metal contacts. Transmission line method results further confirmed that p-type contacts became Schottky-like after thermal stress. The Arrhenius model was employed to estimate the failure lifetime of InGaN solar cells at different temperatures. These results suggest that while InGaN solar cells have high thermal stability, the degradation in the metal contact could be the major limiting factor for these devices under high temperature operation.

E2F1 interactions with hHR23A inhibit its degradation and promote DNA repair

PubMed Central

Singh, Randeep K.; Dagnino, Lina

2016-01-01

Nucleotide excision repair (NER) is a major mechanism for removal of DNA lesions induced by exposure to UV radiation in the epidermis. Recognition of damaged DNA sites is the initial step in their repair, and requires multiprotein complexes that contain XPC and hHR23 proteins, or their orthologues. A variety of transcription factors are also involved in NER, including E2F1. In epidermal keratinocytes, UV exposure induces E2F1 phosphorylation, which allows it to recruit various NER factors to sites of DNA damage. However, the relationship between E2F1 and hHR23 proteins vis-à-vis NER has remained unexplored. We now show that E2F1 and hHR23 proteins can interact, and this interaction stabilizes E2F1, inhibiting its proteasomal degradation. Reciprocally, E2F1 regulates hHR23A subcellular localization, recruiting it to sites of DNA photodamage. As a result, E2F1 and hHR23A enhance DNA repair following exposure to UV radiation, contributing to genomic stability in the epidermis. PMID:27028861

O-GlcNAc Transferase/Host Cell Factor C1 Complex Regulates Gluconeogenesis by Modulating PGC-1α Stability

PubMed Central

Ruan, Hai-Bin; Han, Xuemei; Li, Min-Dian; Singh, Jay Prakash; Qian, Kevin; Azarhoush, Sascha; Zhao, Lin; Bennett, Anton M.; Samuel, Varman T.; Wu, Jing; Yates, John R.; Yang, Xiaoyong

2012-01-01

SUMMARY A major cause of hyperglycemia in diabetic patients is inappropriate hepatic gluconeogenesis. PGC-1α is a master regulator of gluconeogenesis, and its activity is controlled by various post-translational modifications. A small portion of glucose metabolizes through the hexosamine biosynthetic pathway, which leads to O-linked β-N-acetylglucosamine (O-GlcNAc) modification of cytoplasmic and nuclear proteins. Using a proteomic approach, we identified a broad variety of proteins associated with O-GlcNAc transferase (OGT), among which host cell factor C1 (HCF-1) is highly abundant. HCF-1 recruits OGT to O-GlcNAcylate PGC-1α and O-GlcNAcylation facilitates the binding of the deubiquitinase BAP1, thus protecting PGC-1α from degradation and promoting gluconeogenesis. Glucose availability modulates gluconeogenesis through the regulation of PGC-1α O-GlcNAcylation and stability by the OGT/HCF1 complex. Hepatic knockdown of OGT and HCF-1 improves glucose homeostasis in diabetic mice. These findings define the OGT/HCF-1 complex as a glucose sensor and key regulator of gluconeogenesis, shedding light on new strategies for treating diabetes. PMID:22883232

Noisy transcription factor NF-κB oscillations stabilize and sensitize cytokine signaling in space

NASA Astrophysics Data System (ADS)

Gangstad, Sirin W.; Feldager, Cilie W.; Juul, Jeppe; Trusina, Ala

2013-02-01

NF-κB is a major transcription factor mediating inflammatory response. In response to a pro-inflammatory stimulus, it exhibits a characteristic response—a pulse followed by noisy oscillations in concentrations of considerably smaller amplitude. NF-κB is an important mediator of cellular communication, as it is both activated by and upregulates production of cytokines, signals used by white blood cells to find the source of inflammation. While the oscillatory dynamics of NF-κB has been extensively investigated both experimentally and theoretically, the role of the noise and the lower secondary amplitude has not been addressed. We use a cellular automaton model to address these issues in the context of spatially distributed communicating cells. We find that noisy secondary oscillations stabilize concentric wave patterns, thus improving signal quality. Furthermore, both lower secondary amplitude as well as noise in the oscillation period might be working against chronic inflammation, the state of self-sustained and stimulus-independent excitations. Our findings suggest that the characteristic irregular secondary oscillations of lower amplitude are not accidental. On the contrary, they might have evolved to increase robustness of the inflammatory response and the system's ability to return to a pre-stimulated state.

Influence of watershed topographic and socio-economic attributes on the climate sensitivity of global river water quality

NASA Astrophysics Data System (ADS)

Khan, Afed U.; Jiang, Jiping; Wang, Peng; Zheng, Yi

2017-10-01

Surface waters exhibit regionalization due to various climatic conditions and anthropogenic activities. Here we assess the impact of topographic and socio-economic factors on the climate sensitivity of surface water quality, estimated using an elasticity approach (climate elasticity of water quality (CEWQ)), and identify potential risks of instability in different regions and climatic conditions. Large global datasets were used for 12 main water quality parameters from 43 water quality monitoring stations located at large major rivers. The results demonstrated that precipitation elasticity shows higher sensitivity to topographic and socio-economic determinants as compared to temperature elasticity. In tropical climate class (A), gross domestic product (GDP) played an important role in stabilizing the CEWQ. In temperate climate class (C), GDP played the same role in stability, while the runoff coefficient, slope, and population density fuelled the risk of instability. The results implied that watersheds with lower runoff coefficient, thick population density, over fertilization and manure application face a higher risk of instability. We discuss the socio-economic and topographic factors that cause instability of CEWQ parameters and conclude with some suggestions for watershed managers to bring sustainability in freshwater bodies.

Inositol polyphosphate multikinase is a coactivator for serum response factor-dependent induction of immediate early genes

PubMed Central

Kim, Eunha; Tyagi, Richa; Lee, Joo-Young; Park, Jina; Kim, Young-ran; Beon, Jiyoon; Chen, Po Yu; Cha, Jiyoung Y.; Snyder, Solomon H.; Kim, Seyun

2013-01-01

Inositol polyphosphate multikinase (IPMK) is a notably pleiotropic protein. It displays both inositol phosphate kinase and phosphatidylinositol kinase catalytic activities. Noncatalytically, IPMK stabilizes the mammalian target of rapamycin complex 1 and acts as a transcriptional coactivator for CREB-binding protein/E1A binding protein p300 and tumor suppressor protein p53. Serum response factor (SRF) is a major transcription factor for a wide range of immediate early genes. We report that IPMK, in a noncatalytic role, is a transcriptional coactivator for SRF mediating the transcription of immediate early genes. Stimulation by serum of many immediate early genes is greatly reduced by IPMK deletion. IPMK stimulates expression of these genes, an influence also displayed by catalytically inactive IPMK. IPMK acts by binding directly to SRF and thereby enhancing interactions of SRF with the serum response element of diverse genes. PMID:24248338

Impact of sludge layer geometry on the hydraulic performance of a waste stabilization pond.

PubMed

Ouedraogo, Faissal R; Zhang, Jie; Cornejo, Pablo K; Zhang, Qiong; Mihelcic, James R; Tejada-Martinez, Andres E

2016-08-01

Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is needed. One major factor determining the hydraulic performance of a WSP is sludge accumulation, which alters the volume of the pond. In this study, computational fluid dynamics (CFD) analysis was applied to investigate the impact of sludge layer geometry on hydraulic performance of a facultative pond, typically used in many small communities throughout the developing world. Four waste stabilization pond cases with different sludge volumes and distributions were investigated. Results indicate that sludge distribution and volume have a significant impact on wastewater treatment efficiency and capacity. Although treatment capacity is reduced with accumulation of sludge, the latter may induce a baffling effect which causes the flow to behave closer to that of plug flow reactor and thus increase treatment efficiency. In addition to sludge accumulation and distribution, the impact of water surface level is also investigated through two additional cases. Findings show that an increase in water level while keeping a constant flow rate can result in a significant decrease in the hydraulic performance by reducing the sludge baffling effect, suggesting a careful monitoring of sludge accumulation and water surface level in WSP systems. Published by Elsevier Ltd.

Hepatic Arterial Embolization and Chemoembolization in the Management of Patients with Large-Volume Liver Metastases

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

Kamat, Paresh P.; Gupta, Sanjay; Ensor, Joe E.

The purpose of this study was to assess the role of hepatic arterial embolization (HAE) and chemoembolization (HACE) in patients with large-volume liver metastases. Patients with metastatic neuroendocrine tumors, melanomas, or gastrointestinal stromal tumors (GISTs) with >75% liver involvement who underwent HAE or HACE were included in the study. Radiologic response, progression-free survival (PFS), overall survival (OS), and postprocedure complications were assessed. Sixty patients underwent 123 treatment sessions. Of the 48 patients for whom follow-up imaging was available, partial response was seen in 12 (25%) patients, minimal response in 6 (12%), stable disease in 22 (46%), and progressive disease inmore » 8 (17%). Median OS and PFS were 9.3 and 4.9 months, respectively. Treatment resulted in radiologic response or disease stabilization in 82% and symptomatic response in 65% of patients with neuroendocrine tumors. Patients with neuroendocrine tumors had higher response rates (44% vs. 27% and 0%; p = 0.31) and longer PFS (9.2 vs. 2.0 and 2.3 months; p < 0.0001) and OS (17.9 vs. 2.4 and 2.3 months; p < 0.0001) compared to patients with melanomas and GISTs. Major complications occurred in 21 patients after 23 (19%) of the 123 sessions. Nine of the 12 patients who developed major complications resulting in death had additional risk factors-carcinoid heart disease, sepsis, rapidly worsening performance status, or anasarca. In conclusion, in patients with neuroendocrine tumors with >75% liver involvement, HAE/HACE resulted in symptom palliation and radiologic response or disease stabilization in the majority of patients. Patients with hepatic metastases from melanomas and GISTs, however, did not show any appreciable benefit from this procedure. Patients with massive liver tumor burden, who have additional risk factors, should not be subjected to HAE/HACE because of the high risk of procedure-related mortality.« less

Delineating selection and mediation effects among childhood personality and environmental risk factors in the development of adolescent substance abuse.

PubMed

Hicks, Brian M; Johnson, Wendy; Durbin, C Emily; Blonigen, Daniel M; Iacono, William G; McGue, Matt

2014-01-01

Utilizing the large, longitudinal Minnesota Twin Family Study (N = 2510; 96 % European American ancestry), we examined the influence of several person-environment transactions on adolescent substance abuse. We focused on the two childhood personality traits found to be most predictive of substance abuse in this sample-socialization (willingness to follow rules and endorse conventional values) and boldness (social engagement and assurance, stress resilience, thrill seeking)-and the environmental variables of antisocial and prosocial peers, academic engagement, parent-child relationship quality, and stressful life events. Path analysis revealed that low socialization had a selection effect for each environmental risk factor, that is, socialization at age 11 predicted environmental risk at age 14, after controlling for the stability of the environmental variables from ages 11 to 14. Antisocial peers and academic engagement at age 14 then mediated some of the risk of low socialization on substance abuse at age 17, but the majority of risk for substance abuse was accounted for by the stability of socialization from age 11 to 14. Boldness at age 11 also increased risk for substance abuse, but did so primarily via a direct effect. The findings help to parse the nature of person-environment transactions across multiple personality traits and contextual risk factors that contribute to adolescent substance abuse.

Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior.

PubMed

Meier, Madeline H; Slutske, Wendy S; Heath, Andrew C; Martin, Nicholas G

2011-05-01

Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior were examined in a large community sample of 6,383 adult male, female, and opposite-sex twins. Retrospective reports of childhood conduct disorder (prior to 18 years of age) were obtained when participants were approximately 30 years old, and lifetime reports of adult antisocial behavior (antisocial behavior after 17 years of age) were obtained 8 years later. Results revealed that either the genetic or the shared environmental factors influencing childhood conduct disorder differed for males and females (i.e., a qualitative sex difference), but by adulthood, these sex-specific influences on antisocial behavior were no longer apparent. Further, genetic and environmental influences accounted for proportionally the same amount of variance in antisocial behavior for males and females in childhood and adulthood (i.e., there were no quantitative sex differences). Additionally, the stability of antisocial behavior from childhood to adulthood was slightly greater for males than females. Though familial factors accounted for more of the stability of antisocial behavior for males than females, genetic factors accounted for the majority of the covariation between childhood conduct disorder and adult antisocial behavior for both sexes. The genetic influences on adult antisocial behavior overlapped completely with the genetic influences on childhood conduct disorder for both males and females. Implications for future twin and molecular genetic studies are discussed.

Sex Differences in the Genetic and Environmental Influences on Childhood Conduct Disorder and Adult Antisocial Behavior

PubMed Central

Meier, Madeline H.; Slutske, Wendy S.; Heath, Andrew C.; Martin, Nicholas G.

2011-01-01

Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior were examined in a large community sample of 6,383 adult male, female, and opposite-sex twins. Retrospective reports of childhood conduct disorder (prior to age 18) were obtained when participants were approximately 30 years old, and lifetime reports of adult antisocial behavior (antisocial behavior after age 17) were obtained eight years later. Results revealed that either the genetic or shared environmental factors influencing childhood conduct disorder differed for males and females (i.e., a qualitative sex difference), but by adulthood, these sex-specific influences on antisocial behavior were no longer apparent. Further, genetic and environmental influences accounted for proportionally the same amount of variance in antisocial behavior for males and females in childhood and adulthood (i.e., no quantitative sex differences). Additionally, the stability of antisocial behavior from childhood to adulthood was slightly greater for males than females. Though familial factors accounted for more of the stability of antisocial behavior for males than females, genetic factors accounted for the majority of the covariation between childhood conduct disorder and adult antisocial behavior for both sexes. The genetic influences on adult antisocial behavior overlapped completely with the genetic influences on childhood conduct disorder for both males and females. Implications for future twin and molecular genetic studies are discussed. PMID:21319923

Delineating Selection and Mediation Effects among Childhood Personality and Environmental Risk Factors in the Development of Adolescent Substance Abuse

PubMed Central

Hicks, Brian M.; Johnson, Wendy; Durbin, C. Emily; Blonigen, Daniel M.; Iacono, William G.; McGue, Matt

2014-01-01

Utilizing the large, longitudinal Minnesota Twin Family Study (N = 2510; 96% European American ancestry), we examined the influence of several person-environment transactions on adolescent substance abuse. We focused on the two childhood personality traits found to be most predictive of substance abuse in this sample—socialization (willingness to follow rules and endorse conventional values) and boldness (social engagement and assurance, stress resilience, thrill seeking)—and the environmental variables of antisocial and prosocial peers, academic engagement, parent-child relationship quality, and stressful life events. Path analysis revealed that low socialization had a selection effect for each environmental risk factor, that is, socialization at age 11 predicted environmental risk at age 14, after controlling for the stability of the environmental variables from ages 11 to 14. Antisocial peers and academic engagement at age 14 then mediated some of the risk of low socialization on substance abuse at age 17, but the majority of risk for substance abuse was accounted for by the stability of socialization from age 11 to 14. Boldness at age 11 also increased risk for substance abuse, but did so primarily via a direct effect. The findings help to parse the nature of person-environment transactions across multiple personality traits and contextual risk factors that contribute to adolescent substance abuse. PMID:24337735

Nanotechnology in bone tissue engineering.

PubMed

Walmsley, Graham G; McArdle, Adrian; Tevlin, Ruth; Momeni, Arash; Atashroo, David; Hu, Michael S; Feroze, Abdullah H; Wong, Victor W; Lorenz, Peter H; Longaker, Michael T; Wan, Derrick C

2015-07-01

Nanotechnology represents a major frontier with potential to significantly advance the field of bone tissue engineering. Current limitations in regenerative strategies include impaired cellular proliferation and differentiation, insufficient mechanical strength of scaffolds, and inadequate production of extrinsic factors necessary for efficient osteogenesis. Here we review several major areas of research in nanotechnology with potential implications in bone regeneration: 1) nanoparticle-based methods for delivery of bioactive molecules, growth factors, and genetic material, 2) nanoparticle-mediated cell labeling and targeting, and 3) nano-based scaffold construction and modification to enhance physicochemical interactions, biocompatibility, mechanical stability, and cellular attachment/survival. As these technologies continue to evolve, ultimate translation to the clinical environment may allow for improved therapeutic outcomes in patients with large bone deficits and osteodegenerative diseases. Traditionally, the reconstruction of bony defects has relied on the use of bone grafts. With advances in nanotechnology, there has been significant development of synthetic biomaterials. In this article, the authors provided a comprehensive review on current research in nanoparticle-based therapies for bone tissue engineering, which should be useful reading for clinicians as well as researchers in this field. Copyright © 2015 Elsevier Inc. All rights reserved.

The Project for Developing Countermeasures against Landslides in the Abay River Gorge, Ethiopia

NASA Astrophysics Data System (ADS)

Guta, H. E.

2016-12-01

The Blue Nile Gorge of Ethiopia is characterized by high relief landscape. The stretch of major arterial road that connects Ethiopia to Sudan passes through the Gorge. The Gorge is plagued by swarms of landslides which makes it a tremendous obstacle for travel and communication. Therefore, landside study was carried out from 2010 to 2012 by JICA and Geological survey of Ethiopia to figure out the mechanisms that trigger the swarms of landslides that occur in the area and identify appropriate countermeasures that would be best implemented. The study included geomorphologic and geologic survey, drilling survey, displacement monitoring, ground water and precipitation monitoring, geophysical exploration, and stability analysis. About 42 landslide monitoring instruments namely extensometers (both surface and borehole), inclinometers and ground water level meters were installed in four highly landslide prone areas to detect slip surface, and determine amount and direction of movement. The amount of landslide movement at the four zones is 42.4, 57.6, 294.9 and 136mm during rainy season. Ground water level rising, nature of material and intense rainfall are found to be among the major triggering factors. Stability analysis using Simple Jambu and modified Fellenus methods was conducted resulting in safety factor Fs less than one and reasonably 0.98 by adopting shear parameters of soils by back analysis. By assuming cohesion (c') to be very close to 0 due to landslide blocks active movement when ground water rises during rainy season, Shear resistance angle, ɸ, was obtained to be 10.80, 26.30, 10.20 and 16.30 in the four areas using Modified Fellenius method and 10.70, 26.60, 10.00 and 16.10 using Simple Janbu method. Effect of countermeasures was checked by trial calculation. Accordingly the factory of safety increased from 0.98 to 1.2 when ɸ=60, ground water is lowered by 6m, and steel pipe pile of ɸ500mm x t40mm at an interval of 1.9m are implemented. consequently, buttress fill works and surface drainage works are designed countermeasures in the first stage. Furthermore, improvement of safety factor in the landslides by steep pile works or horizontal drainage borings are suitable countermeasures to be adopted in the second stage. Key words: Blue Nile Gorge, Landslide, Slope stability analysis, Countermeasure works

Personality Correlates of Midlife Cardiometabolic Risk: The Explanatory Role of Higher-Order Factors of the Five Factor Model

PubMed Central

Dermody, Sarah S.; Wright, Aidan G.C.; Cheong, JeeWon; Miller, Karissa G.; Muldoon, Matthew F.; Flory, Janine D.; Gianaros, Peter J.; Marsland, Anna L.; Manuck, Stephen B.

2015-01-01

Objective Varying associations are reported between Five Factor Model (FFM) personality traits and cardiovascular diseaabolic risk within a hierarchical model of personality that posits higherse risk. Here, we further examine dispositional correlates of cardiomet -order traits of Stability (shared variance of Agreeableness, Conscientiousness, inverse Neuroticism) and Plasticity (Extraversion, Openness), and test hypothesized mediation via biological and behavioral factors. Method In an observational study of 856 community volunteers aged 30–54 years (46% male, 86% Caucasian), latent variable FFM traits (using multiple-informant reports) and aggregated cardiometabolic risk (indicators: insulin resistance, dyslipidemia, blood pressure, adiposity) were estimated using confirmatory factor analysis (CFA). The cardiometabolic factor was regressed on each personality factor or higher-order trait. Cross-sectional indirect effects via systemic inflammation, cardiac autonomic control, and physical activity were tested. Results CFA models confirmed the Stability “meta-trait,” but not Plasticity. Lower Stability was associated with heightened cardiometabolic risk. This association was accounted for by inflammation, autonomic function, and physical activity. Among FFM traits, only Openness was associated with risk over and above Stability and, unlike Stablity, this relationship was unexplained by the intervening variables. Conclusions A Stability meta-trait covaries with midlife cardiometabolic risk, and this association is accounted for by three candidate biological and behavioral factors. PMID:26249259

Theoretical studies of surface enhanced hyper-Raman spectroscopy: The chemical enhancement mechanism

NASA Astrophysics Data System (ADS)

Valley, Nicholas; Jensen, Lasse; Autschbach, Jochen; Schatz, George C.

2010-08-01

Hyper-Raman spectra for pyridine and pyridine on the surface of a tetrahedral 20 silver atom cluster are calculated using static hyperpolarizability derivatives obtained from time dependent density functional theory. The stability of the results with respect to choice of exchange-correlation functional and basis set is verified by comparison with experiment and with Raman spectra calculated for the same systems using the same methods. Calculated Raman spectra were found to match well with experiment and previous theoretical calculations. The calculated normal and surface enhanced hyper-Raman spectra closely match experimental results. The chemical enhancement factors for hyper-Raman are generally larger than for Raman (102-104 versus 101-102). Integrated hyper-Raman chemical enhancement factors are presented for a set of substituted pyridines. A two-state model is developed to predict these chemical enhancement factors and this was found to work well for the majority of the molecules considered, providing a rationalization for the difference between hyper-Raman and Raman enhancement factors.

RNA major groove modifications improve siRNA stability and biological activity

PubMed Central

Terrazas, Montserrat; Kool, Eric T.

2009-01-01

RNA 5-methyl and 5-propynyl pyrimidine analogs were substituted into short interfering RNAs (siRNAs) to probe major groove steric effects in the active RNA-induced silencing complex (RISC). Synthetic RNA guide strands containing varied combinations of propynyl and methyl substitution revealed that all C-5 substitutions increased the thermal stability of siRNA duplexes containing them. Cellular gene suppression experiments using luciferase targets in HeLa cells showed that the bulky 5-propynyl modification was detrimental to RNA interference activity, despite its stabilization of the helix. Detrimental effects of this substitution were greatest at the 5′-half of the guide strand, suggesting close steric approach of proteins in the RISC complex with that end of the siRNA/mRNA duplex. However, substitutions with the smaller 5-methyl group resulted in gene silencing activities comparable to or better than that of wild-type siRNA. The major groove modifications also increased the serum stability of siRNAs. PMID:19042976

Off-pathway assembly of fimbria subunits is prevented by chaperone CfaA of CFA/I fimbriae from enterotoxigenic E. coli.

PubMed

Bao, Rui; Liu, Yang; Savarino, Stephen J; Xia, Di

2016-12-01

The assembly of the class 5 colonization factor antigen I (CFA/I) fimbriae of enterotoxigenic E. coli was proposed to proceed via the alternate chaperone-usher pathway. Here, we show that in the absence of the chaperone CfaA, CfaB, the major pilin subunit of CFA/I fimbriae, is able to spontaneously refold and polymerize into cyclic trimers. CfaA kinetically traps CfaB to form a metastable complex that can be stabilized by mutations. Crystal structure of the stabilized complex reveals distinctive interactions provided by CfaA to trap CfaB in an assembly competent state through donor-strand complementation (DSC) and cleft-mediated anchorage. Mutagenesis indicated that DSC controls the stability of the chaperone-subunit complex and the cleft-mediated anchorage of the subunit C-terminus additionally assist in subunit refolding. Surprisingly, over-stabilization of the chaperone-subunit complex led to delayed fimbria assembly, whereas destabilizing the complex resulted in no fimbriation. Thus, CfaA acts predominantly as a kinetic trap by stabilizing subunit to avoid its off-pathway self-polymerization that results in energetically favorable trimers and could serve as a driving force for CFA/I pilus assembly, representing an energetic landscape unique to class 5 fimbria assembly. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Molecular Microbiology published by John Wiley & Sons Ltd.

A theoretical study of complexes formed between cations and curved aromatic systems: electrostatics does not always control cation-π interaction.

PubMed

Carrazana-García, Jorge A; Cabaleiro-Lago, Enrique M; Rodríguez-Otero, Jesús

2017-04-19

The present work studies the interaction of two extended curved π-systems (corannulene and sumanene) with various cations (sodium, potassium, ammonium, tetramethylammonium, guanidinium and imidazolium). Polyatomic cations are models of groups found in important biomolecules in which cation-π interaction plays a fundamental role. The results indicate an important size effect: with extended π systems and cations of the size of potassium and larger, dispersion is much more important than has been generally recognized for cation-π interactions. In most of the systems studied here, the stability of the cation-π complexes is the result of a balanced combination of electrostatic, induction and dispersion contributions. None of the systems studied here owes its stability to the electrostatic interaction more than 42%. Induction dominates stabilization in complexes with sodium, and in some of the potassium and ammonium complexes. In complexes with large cations and with flat cations dispersion is the major stabilizing contribution and can provide more than 50% of the stabilization energy. This implies that theoretical studies of the cation-π interaction involving large or even medium-size fragments require a level of calculation capable of properly modelling dispersion. The separation between the cation and the π system is another important factor to take into account, especially when the fragments of the cation-π complex are bound (for example, to a protein backbone) and cannot interact at the most favourable distance.

Adolescent Determinants of Abortion Attitudes

PubMed Central

Pacheco, Julianna; Kreitzer, Rebecca

2016-01-01

The stability of abortion opinions suggests that pre-adult factors influence these attitudes more than contemporaneous political events. Surprisingly, however, we know little about the origins of abortion opinions, no doubt because the majority of research focuses on cross-sectional analyses of patterns across cohorts. We use a developmental model that links familial and contextual factors during adolescence to abortion attitudes years later when respondents are between 21 and 38 years old. Findings show that religious adherence and maternal gender role values are significant predictors of adult abortion opinions, even after controlling for contemporaneous religious adherence and the respondents’ own views on gender roles. Adolescent religious adherence matters more than religious denomination for adult abortion attitudes. The results have important implications for future trends in abortion attitudes in light of declining religiosity among Americans. PMID:27257307

The Impact of a Single Nucleotide Polymorphism in SIGMAR1 on Depressive Symptoms in Major Depressive Disorder and Bipolar Disorder.

PubMed

Mandelli, Laura; Wang, Sheng-Min; Han, Changsu; Lee, Soo-Jung; Patkar, Ashwin A; Masand, Prakash S; Pae, Chi-Un; Serretti, Alessandro

2017-03-01

Ample evidence suggested a role of sigma-1 receptor in affective disorders since the interaction of numerous antidepressants with sigma receptors was discovered. A recent study on Japanese subjects found a genetic variant within the encoding gene SIGMAR1 (rs1800866A>C) associated with major depressive disorder (MDD). We aimed to evaluate the same polymorphism in both MDD and bipolar disorder (BD) as well as its relationship to response to treatment with antidepressants and mood stabilizers. A total of 238 MDD patients treated for an acute episode of depression, 132 BD patients in treatment with mood stabilizers for a manic or mixed episode, and 324 controls were genotyped for rs1800866. At discharge, response to treatments was evaluated in MDD and BD patients by the Hamilton Rating Scale for Depression (HRSD) and the Young Mania Rating Score (YMRS), respectively. In our Korean sample, allele frequencies were different from those reported in other Asian and non-Asian populations. The CC genotype was associated with BD and, as a trend, with MDD. No significant effect was observed on response to antidepressants in MDD or mood stabilizers in BD, although the CC genotype was more frequent among BD patients experiencing a mixed episode. The present findings are the first to propose the putative role of genetic variants within SIGMAR1 and sigma-1 receptor in BD. Sigma-1 receptor can modulate a number of central neurotransmitter systems as well as some other signaling pathways (e.g., neurotrophin and growth factor signaling) which are seemingly involved in BD and other mood disorders.

Surgical options for lumbosacral fusion: biomechanical stability, advantage, disadvantage and affecting factors in selecting options.

PubMed

Yoshihara, Hiroyuki

2014-07-01

Numerous surgical procedures and instrumentation techniques for lumbosacral fusion (LSF) have been developed. This is probably because of its high mechanical demand and unique anatomy. Surgical options include anterior column support (ACS) and posterior stabilization procedures. Biomechanical studies have been performed to verify the stability of those options. The options have their own advantage but also disadvantage aspects. This review article reports the surgical options for lumbosacral fusion, their biomechanical stability, advantages/disadvantages, and affecting factors in option selection. Review of literature. LSF has lots of options both for ACS and posterior stabilization procedures. Combination of posterior stabilization procedures is an option. Furthermore, combinations of ACS and posterior stabilization procedures are other options. It is difficult to make a recommendation or treatment algorithm of LSF from the current literature. However, it is important to know all aspects of the options and decision-making of surgical options for LSF needs to be tailored for each patient, considering factors such as biomechanical stress and osteoporosis.

Global agricultural intensification during climate change: a role for genomics.

PubMed

Abberton, Michael; Batley, Jacqueline; Bentley, Alison; Bryant, John; Cai, Hongwei; Cockram, James; de Oliveira, Antonio Costa; Cseke, Leland J; Dempewolf, Hannes; De Pace, Ciro; Edwards, David; Gepts, Paul; Greenland, Andy; Hall, Anthony E; Henry, Robert; Hori, Kiyosumi; Howe, Glenn Thomas; Hughes, Stephen; Humphreys, Mike; Lightfoot, David; Marshall, Athole; Mayes, Sean; Nguyen, Henry T; Ogbonnaya, Francis C; Ortiz, Rodomiro; Paterson, Andrew H; Tuberosa, Roberto; Valliyodan, Babu; Varshney, Rajeev K; Yano, Masahiro

2016-04-01

Agriculture is now facing the 'perfect storm' of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Acidic Residues Control the Dimerization of the N-terminal Domain of Black Widow Spiders’ Major Ampullate Spidroin 1

NASA Astrophysics Data System (ADS)

Bauer, Joschka; Schaal, Daniel; Eisoldt, Lukas; Schweimer, Kristian; Schwarzinger, Stephan; Scheibel, Thomas

2016-09-01

Dragline silk is the most prominent amongst spider silks and comprises two types of major ampullate spidroins (MaSp) differing in their proline content. In the natural spinning process, the conversion of soluble MaSp into a tough fiber is, amongst other factors, triggered by dimerization and conformational switching of their helical amino-terminal domains (NRN). Both processes are induced by protonation of acidic residues upon acidification along the spinning duct. Here, the structure and monomer-dimer-equilibrium of the domain NRN1 of Latrodectus hesperus MaSp1 and variants thereof have been investigated, and the key residues for both could be identified. Changes in ionic composition and strength within the spinning duct enable electrostatic interactions between the acidic and basic pole of two monomers which prearrange into an antiparallel dimer. Upon naturally occurring acidification this dimer is stabilized by protonation of residue E114. A conformational change is independently triggered by protonation of clustered acidic residues (D39, E76, E81). Such step-by-step mechanism allows a controlled spidroin assembly in a pH- and salt sensitive manner, preventing premature aggregation of spider silk proteins in the gland and at the same time ensuring fast and efficient dimer formation and stabilization on demand in the spinning duct.

Stability and change in adult personality over 6 years: findings from the Victoria Longitudinal Study.

PubMed

Small, Brent J; Hertzog, Christopher; Hultsch, David F; Dixon, Roger A

2003-05-01

Data from the Victoria Longitudinal Study were used to examine the 6-year longitudinal stability of personality in older adults. Personality was measured with the NEO Personality Inventory. The longitudinal sample consisted of 223 adults initially ranging from 55 to 85 years of age. Longitudinal confirmatory factor analyses were used to examine the stability of individual differences in change over time, and the stability of the longitudinal factor structure. The results indicated both substantial stability at the level of individual differences in change, as well as significant individual differences in change that were related to age and gender. Finally, the factor structure of personality was invariant over time but did not approximate simple structure for the five dimensions of personality. Our study of 6-year personality development provided both (a). a confirmation of early significant stability findings and (b). unique evidence for significant individual differences in late adulthood.

A Comprehensive Transcriptomic and Proteomic Analysis of Hydra Head Regeneration.

PubMed

Petersen, Hendrik O; Höger, Stefanie K; Looso, Mario; Lengfeld, Tobias; Kuhn, Anne; Warnken, Uwe; Nishimiya-Fujisawa, Chiemi; Schnölzer, Martina; Krüger, Marcus; Özbek, Suat; Simakov, Oleg; Holstein, Thomas W

2015-08-01

The cnidarian freshwater polyp Hydra sp. exhibits an unparalleled regeneration capacity in the animal kingdom. Using an integrative transcriptomic and stable isotope labeling by amino acids in cell culture proteomic/phosphoproteomic approach, we studied stem cell-based regeneration in Hydra polyps. As major contributors to head regeneration, we identified diverse signaling pathways adopted for the regeneration response as well as enriched novel genes. Our global analysis reveals two distinct molecular cascades: an early injury response and a subsequent, signaling driven patterning of the regenerating tissue. A key factor of the initial injury response is a general stabilization of proteins and a net upregulation of transcripts, which is followed by a subsequent activation cascade of signaling molecules including Wnts and transforming growth factor (TGF) beta-related factors. We observed moderate overlap between the factors contributing to proteomic and transcriptomic responses suggesting a decoupled regulation between the transcriptional and translational levels. Our data also indicate that interstitial stem cells and their derivatives (e.g., neurons) have no major role in Hydra head regeneration. Remarkably, we found an enrichment of evolutionarily more recent genes in the early regeneration response, whereas conserved genes are more enriched in the late phase. In addition, genes specific to the early injury response were enriched in transposon insertions. Genetic dynamicity and taxon-specific factors might therefore play a hitherto underestimated role in Hydra regeneration. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Modelling and optimising of physicochemical features of walnut-oil beverage emulsions by implementation of response surface methodology: effect of preparation conditions on emulsion stability.

PubMed

Homayoonfal, Mina; Khodaiyan, Faramarz; Mousavi, Mohammad

2015-05-01

The major purpose of this study is to apply response surface methodology to model and optimise processing conditions for the preparation of beverage emulsions with maximum emulsion stability and viscosity, minimum particle size, turbidity loss rate, size index and peroxide value changes. A three-factor, five-level central composite design was conducted to estimate the effects of three independent variables: ultrasonic time (UT, 5-15 min), walnut-oil content (WO, 4-10% (w/w)) and Span 80 content (S80, 0.55-0.8). The results demonstrated the empirical models were satisfactorily (p < 0.0001) fitted to the experimental data. Evaluation of responses by analysis of variance indicated high coefficient determination values. The overall optimisation of preparation conditions was an UT of 14.630 min, WO content of 8.238% (w/w), and S80 content of 0.782% (w/w). Under this optimum region, responses were found to be 219.198, 99.184, 0.008, 0.008, 2.43 and 16.65 for particle size, emulsion stability, turbidity loss rate, size index, viscosity and peroxide value changes, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Bayesian phylogenetic approach to estimating the stability of linguistic features and the genetic biasing of tone.

PubMed

Dediu, Dan

2011-02-07

Language is a hallmark of our species and understanding linguistic diversity is an area of major interest. Genetic factors influencing the cultural transmission of language provide a powerful and elegant explanation for aspects of the present day linguistic diversity and a window into the emergence and evolution of language. In particular, it has recently been proposed that linguistic tone-the usage of voice pitch to convey lexical and grammatical meaning-is biased by two genes involved in brain growth and development, ASPM and Microcephalin. This hypothesis predicts that tone is a stable characteristic of language because of its 'genetic anchoring'. The present paper tests this prediction using a Bayesian phylogenetic framework applied to a large set of linguistic features and language families, using multiple software implementations, data codings, stability estimations, linguistic classifications and outgroup choices. The results of these different methods and datasets show a large agreement, suggesting that this approach produces reliable estimates of the stability of linguistic data. Moreover, linguistic tone is found to be stable across methods and datasets, providing suggestive support for the hypothesis of genetic influences on its distribution.

Genomic Approach to Understand the Association of DNA Repair with Longevity and Healthy Aging Using Genomic Databases of Oldest-Old Population

PubMed Central

Kim, Hyun Soo

2018-01-01

Aged population is increasing worldwide due to the aging process that is inevitable. Accordingly, longevity and healthy aging have been spotlighted to promote social contribution of aged population. Many studies in the past few decades have reported the process of aging and longevity, emphasizing the importance of maintaining genomic stability in exceptionally long-lived population. Underlying reason of longevity remains unclear due to its complexity involving multiple factors. With advances in sequencing technology and human genome-associated approaches, studies based on population-based genomic studies are increasing. In this review, we summarize recent longevity and healthy aging studies of human population focusing on DNA repair as a major factor in maintaining genome integrity. To keep pace with recent growth in genomic research, aging- and longevity-associated genomic databases are also briefly introduced. To suggest novel approaches to investigate longevity-associated genetic variants related to DNA repair using genomic databases, gene set analysis was conducted, focusing on DNA repair- and longevity-associated genes. Their biological networks were additionally analyzed to grasp major factors containing genetic variants of human longevity and healthy aging in DNA repair mechanisms. In summary, this review emphasizes DNA repair activity in human longevity and suggests approach to conduct DNA repair-associated genomic study on human healthy aging.

PRKCDBP (CAVIN3) and CRY2 associate with major depressive disorder.

PubMed

Kovanen, Leena; Donner, Kati; Kaunisto, Mari; Partonen, Timo

2017-01-01

Dysfunctions in the intrinsic clocks are suggested in patients with depressive disorders. The cryptochrome circadian clocks 1 and 2 (CRY1 and CRY2) proteins modulate circadian rhythms in a cell and influence emotional reactions and mood in an individual. The protein kinase C delta binding protein (PRKCDBP, or CAVIN3), similar to the serum deprivation response protein (SDPR, or CAVIN2), reduces metabolic stability of the PER2-CRY2 transcription factor complex that plays a role in the circadian rhythm synchronization. Our aim was to study SDPR, PRKCDBP, CRY1 and CRY2 genetic variants in depressive disorders. The sample included 5910 Finnish individuals assessed with the Munich-Composite International Diagnostic Interview (M-CIDI) in year 2000. In year 2011, 3424 individuals were assessed again. After genotype quality control, there were 383 subjects with major depressive disorder, 166 with dysthymia, and 479 with depressive disorders (major depressive disorder, dysthymia or both), and 4154 healthy controls. A total of 48 single-nucleotide polymorphisms from SDPR, PRKCDBP, CRY1 and CRY2 genes were analyzed using logistic regression models controlling for age and gender. The earlier reported association of CRY2 variants with dysthymia was confirmed and extended to major depressive disorder (q<0.05). In addition, novel associations of PRKCDBP rs1488864 with depressive disorders (q=0.02) and with major depressive disorder in specific (q=0.007) were found. The number of cases was moderate and coverage of PRKCDB was limited. CRY2 and PRKCDBP variants may be risk factors of major depressive disorder and provide information for diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Views of Health System Experts on Macro Factors of Induced Demand

PubMed Central

Khorasani, Elahe; Keyvanara, Mahmoud; Karimi, Saeed; Jazi, Marzie Jafarian

2014-01-01

Background: The probability and severity of effects of induced demand are because of the interaction between a range of factors that can affect physicians and patients behavior. It is also affected by the laws of the markets and organizational arrangements for medical services. This article studies major factors that affect the phenomenon of induced demand with the use of experts’ experiences of the Isfahan University of Medical Sciences. Methods: The research is applied a qualitative method. Semi-structured interview was used for data generation. Participants in this study were people who had been informed in this regard and had to be experienced and were known as experts. Purposive sampling was done for data saturation. Seventeen people were interviewed and criteria such as data “reliability of information” and stability were considered. The anonymity of the interviewees was preserved. The data are transcribed, categorized and then used the thematic analysis. Results: In this study, thematic analysis was conducted, and 77 sub-themes and 3 themes were extracted respectively. The three main themes include infrastructural factors, social factors, and organizational structural factors affecting induced demand. Each of these also has some sub-themes. Conclusions: Results of this research present a framework for analyzing the major causes of induced demand. The causes identified here include complexity of medicine, information mismatch between service providers and consumers, clinical uncertainty, false beliefs, advertisements, insufficient supervision, scarcity of clinical guidelines, weakness of education system, and ignorance of medical ethics. These findings help policymakers to investigate the induced demand phenomenon clear-sighted. PMID:25400888

Turbulent Plume Dispersion over Two-dimensional Idealized Urban Street Canyons

NASA Astrophysics Data System (ADS)

Wong, C. C. C.; Liu, C. H.

2012-04-01

Human activities are the primary pollutant sources which degrade the living quality in the current era of dense and compact cities. A simple and reasonably accurate pollutant dispersion model is helpful to reduce pollutant concentrations in city or neighborhood scales by refining architectural design or urban planning. The conventional method to estimate the pollutant concentration from point/line sources is the Gaussian plume model using empirical dispersion coefficients. Its accuracy is pretty well for applying to rural areas. However, the dispersion coefficients only account for the atmospheric stability and streamwise distance that often overlook the roughness of urban surfaces. Large-scale buildings erected in urban areas significantly modify the surface roughness that in turn affects the pollutant transport in the urban canopy layer (UCL). We hypothesize that the aerodynamic resistance is another factor governing the dispersion coefficient in the UCL. This study is thus conceived to study the effects of urban roughness on pollutant dispersion coefficients and the plume behaviors. Large-eddy simulations (LESs) are carried out to examine the plume dispersion from a ground-level pollutant source over idealized 2D street canyons in neutral stratification. Computations with a wide range of aspect ratios (ARs), including skimming flow to isolated flow regimes, are conducted. The vertical profiles of pollutant distribution for different values of friction factor are compared that all reach a self-similar Gaussian shape. Preliminary results show that the pollutant dispersion is closely related to the friction factor. For relatively small roughness, the factors of dispersion coefficient vary linearly with the friction factor until the roughness is over a certain level. When the friction factor is large, its effect on the dispersion coefficient is less significant. Since the linear region covers at least one-third of the full range of friction factor in our empirical analysis, urban roughness is a major factor for dispersion coefficient. The downstream air quality could then be a function of both atmospheric stability and urban roughness.

Enterococcus faecium biofilm formation: identification of major autolysin AtlAEfm, associated Acm surface localization, and AtlAEfm-independent extracellular DNA Release.

PubMed

Paganelli, Fernanda L; Willems, Rob J L; Jansen, Pamela; Hendrickx, Antoni; Zhang, Xinglin; Bonten, Marc J M; Leavis, Helen L

2013-04-16

Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. IMPORTANCE Nosocomial infections caused by Enterococcus faecium have rapidly increased, and treatment options have become more limited. This is due not only to increasing resistance to antibiotics but also to biofilm-associated infections. DNA is released in biofilm matrix via cell lysis, caused by autolysin, and acts as a matrix stabilizer. In this study, we identified and characterized the major autolysin in E. faecium, which we designated AtlAEfm. atlAEfm disruption resulted in resistance to lysis, reduced extracellular DNA (eDNA), deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and chaining. Furthermore, AtlAEfm is associated with Acm cell surface localization, resulting in less binding to collagen types I and IV in the atlAEfm mutant. We also identified AtlAEfm-independent eDNA release that contributes to cell-cell interactions in the atlAEfm mutant. These findings indicate that AtlAEfm is important in biofilm and collagen binding in E. faecium, making AtlAEfm a promising target for treatment of E. faecium infections.

Porosity and water activity effects on stability of crystalline β-carotene in freeze-dried solids.

PubMed

Harnkarnsujarit, Nathdanai; Charoenrein, Sanguansri; Roos, Yrjö H

2012-11-01

Stability of entrapped crystalline β-carotene as affected by water activity, solids microstructure, and composition of freeze-dried systems was investigated. Aliquots (1000 mm(3) , 20% w/w solids) of solutions of maltodextrins of various dextrose equivalents (M040:DE6, M100:DE11, and M250:DE25.5), M100-sugars (1:1 glucose, fructose and sucrose), and agar for gelation with dispersed β-carotene were frozen at -20, -40, or -80 °C and freeze-dried. Glass transition and α-relaxation temperatures were determined with differential scanning calorimetry and dynamic mechanical analysis, respectively. β-Carotene contents were monitored spectrophotometrically. In the glassy solids, pore microstructure had a major effect on β-carotene stability. Small pores with thin walls and large surface area allowed β-carotene exposure to oxygen which led to a higher loss, whereas structural collapse enhanced stability of β-carotene by decreasing exposure to oxygen. As water plasticized matrices, an increase in molecular mobility in the matrix enhanced β-carotene degradation. Stability of dispersed β-carotene was highest at around 0.2 a(w) , but decreasing structural relaxation times above the glass transition correlated well with the rate of β-carotene degradation at higher a(w) . Microstructure, a(w) , and component mobility are important factors in the control of stability of β-carotene in freeze-dried solids. β-Carotene expresses various nutritional benefits; however, it is sensitive to oxygen and the degradation contributes to loss of nutritional values as well as product color. To increase stability of β-carotene in freeze-dried foods, the amount of oxygen penetration need to be limited. The modification of freeze-dried food structures, for example, porosity and structural collapse, components, and humidity effectively enhance the stability of dispersed β-carotene in freeze-dried solids. © 2012 Institute of Food Technologists®

Molecular cloning and expression of a gene for a factor which stabilizes formation of inhibitor-mitochondrial ATPase complex from Saccharomyces cerevisiae.

PubMed

Akashi, A; Yoshida, Y; Nakagoshi, H; Kuroki, K; Hashimoto, T; Tagawa, K; Imamoto, F

1988-10-01

Stabilizing factor, a 9 kDa protein, stabilizes and facilitates formation of the complex between mitochondrial ATP synthase and its intrinsic inhibitor protein. A clone containing the gene encoding the 9 kDa protein was selected from a yeast genomic library to determine the structure of its precursor protein. As deduced from the nucleotide sequence, the precursor of the yeast 9 kDa stabilizing factor contains 86 amino acid residues and has a molecular weight of 10,062. From the predicted sequence we infer that the stabilizing factor precursor contains a presequence of 23 amino acid residues at its amino terminus. We also used S1 mapping to determine the initiation site of transcription under glucose-repressed or derepressed conditions. These experiments suggest that transcription of this gene starts at three different sites and that only one of them is not affected by the presence of glucose.

Expression, purification, and characterization of recombinant human and murine milk fat globule-epidermal growth factor-factor 8.

PubMed

Castellanos, Erick R; Ciferri, Claudio; Phung, Wilson; Sandoval, Wendy; Matsumoto, Marissa L

2016-08-01

Milk fat globule-epidermal growth factor-factor 8 (MFG-E8), as its name suggests, is a major glycoprotein component of milk fat globules secreted by the mammary epithelium. Although its role in milk fat production is unclear, MFG-E8 has been shown to act as a bridge linking apoptotic cells to phagocytes for removal of these dying cells. MFG-E8 is capable of bridging these two very different cell types via interactions through both its epidermal growth factor (EGF)-like domain(s) and its lectin-type C domains. The EGF-like domain interacts with αVβ3 and αVβ5 integrins on the surface of phagocytes, whereas the C domains bind phosphatidylserine found on the surface of apoptotic cells. In an attempt to purify full-length, recombinant MFG-E8 expressed in either insect cells or CHO cells, we find that it is highly aggregated. Systematic truncation of the domain architecture of MFG-E8 indicates that the C domains are mainly responsible for the aggregation propensity. Addition of Triton X-100 to the conditioned cell culture media allowed partial recovery of non-aggregated, full-length MFG-E8. A more comprehensive detergent screen identified CHAPS as a stabilizer of MFG-E8 and allowed purification of a significant portion of non-aggregated, full-length protein. The CHAPS-stabilized recombinant MFG-E8 retained its natural ability to bind both αVβ3 and αVβ5 integrins and phosphatidylserine suggesting that it is properly folded and active. Herein we describe an efficient purification method for production of non-aggregated, full-length MFG-E8. Copyright © 2016 Elsevier Inc. All rights reserved.

Landslides geotechnical analysis. Qualitative assessment by valuation factors

NASA Astrophysics Data System (ADS)

Cuanalo Oscar, Sc D.; Oliva Aldo, Sc D.; Polanco Gabriel, M. E.

2012-04-01

In general, a landslide can cause a disaster when it is combined a number of factors such as an extreme event related to a geological phenomenon, vulnerable elements exposed in a specific geographic area, and the probability of loss and damage evaluated in terms of lives and economic assets, in a certain period of time. This paper presents the qualitative evaluation of slope stability through of Valuation Factors, obtained from the characterization of the determinants and triggers factors that influence the instability; for the first the morphology and topography, geology, soil mechanics, hydrogeology and vegetation to the second, the rain, earthquakes, erosion and scour, human activity, and ultimately dependent factors of the stability analysis, and its influence ranges which greatly facilitate the selection of construction processes best suited to improve the behavior of a slope or hillside. The Valuation Factors are a set of parameters for assessing the influence of conditioning and triggering factors that influence the stability of slopes and hillsides. The characteristics of each factor must be properly categorized to involve its effect on behavior; a way to do this is by assigning a weighted value range indicating its effect on the stability of a slope. It is proposed to use Valuation Factors with weighted values between 0 and 1 (arbitrarily selected but common sense and logic), the first corresponds to no or minimal effect on stability (no effect or very little influence) and the second, the greatest impact on it (has a significant influence). The meddle effects are evaluated with intermediate values.

Control of erythropoietin gene expression and its use in medicine.

PubMed

Jelkmann, Wolfgang

2007-01-01

Erythropoietin (EPO) gene expression is under the control of inhibitory (GATA-2, NF-kappaB) and stimulatory (hypoxia-inducible transcription factor [HIF]-2, hepatocyte nuclear factor [HNF]-4alpha [alpha]) transcription factors. EPO deficiency is the main cause of the anemia in chronic kidney disease (CKD) and a contributing factor in the anemias of inflammation and cancer. Small, orally active compounds capable of stimulating endogenous EPO production are in preclinical or clinical trials for treatment of anemia. These agents include stabilizers of the HIFs that bind to the EPO enhancer and GATA inhibitors which prevent GATA from suppressing the EPO promoter. While HIF stabilizing drugs may prove useful as inexpensive second-line choices, at present, their side effects--particularly tumorigenicity--preclude their use as first-choice therapy. As an alternative, EPO gene therapy has been explored in animal studies and in trials on CKD patients. Here, a major problem is immunogenicity of ex vivo transfected implanted cells and of the recombinant protein produced after ex vivo or in vivo EPO complementary DNA (cDNA) transfer. Recombinant human EPO (rhEPO) engineered in Chinese hamster ovary (CHO) cell cultures (epoetin alpha and epoetin beta [beta]) and its hyperglycosylated analogue darbepoetin alpha are established and safe drugs to avoid allogeneic red blood cell transfusion. Gene-activated EPO (epoetin delta [delta]) from human fibrosarcoma cells (HT-1080) has recently been launched for use in CKD. It is important to know the basics of the technologies, production processes, and structural properties of the novel anti-anemic strategies and drugs.

Using three-dimensional plant root architecture in models of shallow-slope stability.

PubMed

Danjon, Frédéric; Barker, David H; Drexhage, Michael; Stokes, Alexia

2008-05-01

The contribution of vegetation to shallow-slope stability is of major importance in landslide-prone regions. However, existing slope stability models use only limited plant root architectural parameters. This study aims to provide a chain of tools useful for determining the contribution of tree roots to soil reinforcement. Three-dimensional digitizing in situ was used to obtain accurate root system architecture data for mature Quercus alba in two forest stands. These data were used as input to tools developed, which analyse the spatial position of roots, topology and geometry. The contribution of roots to soil reinforcement was determined by calculating additional soil cohesion using the limit equilibrium model, and the factor of safety (FOS) using an existing slope stability model, Slip4Ex. Existing models may incorrectly estimate the additional soil cohesion provided by roots, as the spatial position of roots crossing the potential slip surface is usually not taken into account. However, most soil reinforcement by roots occurs close to the tree stem and is negligible at a distance >1.0 m from the tree, and therefore global values of FOS for a slope do not take into account local slippage along the slope. Within a forest stand on a landslide-prone slope, soil fixation by roots can be minimal between uniform rows of trees, leading to local soil slippage. Therefore, staggered rows of trees would improve overall slope stability, as trees would arrest the downward movement of soil. The chain of tools consisting of both software (free for non-commercial use) and functions available from the first author will enable a more accurate description and use of root architectural parameters in standard slope stability analyses.

Using Three-dimensional Plant Root Architecture in Models of Shallow-slope Stability

PubMed Central

Danjon, Frédéric; Barker, David H.; Drexhage, Michael; Stokes, Alexia

2008-01-01

Background The contribution of vegetation to shallow-slope stability is of major importance in landslide-prone regions. However, existing slope stability models use only limited plant root architectural parameters. This study aims to provide a chain of tools useful for determining the contribution of tree roots to soil reinforcement. Methods Three-dimensional digitizing in situ was used to obtain accurate root system architecture data for mature Quercus alba in two forest stands. These data were used as input to tools developed, which analyse the spatial position of roots, topology and geometry. The contribution of roots to soil reinforcement was determined by calculating additional soil cohesion using the limit equilibrium model, and the factor of safety (FOS) using an existing slope stability model, Slip4Ex. Key Results Existing models may incorrectly estimate the additional soil cohesion provided by roots, as the spatial position of roots crossing the potential slip surface is usually not taken into account. However, most soil reinforcement by roots occurs close to the tree stem and is negligible at a distance >1·0 m from the tree, and therefore global values of FOS for a slope do not take into account local slippage along the slope. Conclusions Within a forest stand on a landslide-prone slope, soil fixation by roots can be minimal between uniform rows of trees, leading to local soil slippage. Therefore, staggered rows of trees would improve overall slope stability, as trees would arrest the downward movement of soil. The chain of tools consisting of both software (free for non-commercial use) and functions available from the first author will enable a more accurate description and use of root architectural parameters in standard slope stability analyses. PMID:17766845

Permeability test and slope stability analysis of municipal solid waste in Jiangcungou Landfill, Shaanxi, China.

PubMed

Yang, Rong; Xu, Zengguang; Chai, Junrui; Qin, Yuan; Li, Yanlong

2016-07-01

With the rapid increase of city waste, landfills have become a major method to deals with municipal solid waste. Thus, the safety of landfills has become a valuable research topic. In this paper, Jiangcungou Landfill, located in Shaanxi, China, was investigated and its slope stability was analyzed. Laboratory tests were used to obtain permeability coefficients of municipal solid waste. Based on the results, the distribution of leachate and stability in the landfill was computed and analyzed. These results showed: the range of permeability coefficient was from 1.0 × 10(-7) cm sec(-1) to 6.0 × 10(-3) cm sec(-1) on basis of laboratory test and some parameters of similar landfills. Owing to the existence of intermediate cover layers in the landfill, the perched water level appeared in the landfill with heavy rain. Moreover, the waste was filled with leachate in the top layer, and the range of leachate level was from 2 m to 5 m in depth under the waste surface in other layers. The closer it gets to the surface of landfill, the higher the perched water level of leachate. It is indicated that the minimum safety factors were 1.516 and 0.958 for winter and summer, respectively. Additionally, the slope failure may occur in summer. The research of seepage and stability in landfills may provide a less costly way to reduce accidents. Landslides often occur in the Jiangcungou Landfill because of the high leachate level. Some measures should be implemented to reduce the leachate level. This paper investigated seepage and slope stability of landfills by numerical methods. These results may provide the basis for increasing stability of landfills.

Some Static Oscillatory and Free Body Tests of Blunt Bodies at Low Subsonic Speeds

NASA Technical Reports Server (NTRS)

Lichtenstein, Jacob H.; Fisher, Lewis R.; Scher, Stanley H.; Lawrence, George F.

1959-01-01

Some blunt-body shapes considered suitable for entry into the earth's atmosphere were tested by both static and oscillatory methods in the Langley stability tunnel. In addition, free-fall tests of some similar models were made in the Langley 20-foot free-spinning tunnel. The results of the tests show that increasing the flare of the body shape increased the dynamic stability and that for flat-faced shapes increasing the corner radius increased the stability. The test data from the Langley stability tunnel were used to compute the damping factor for the models tested in the langley 20-foot free-spinning tunnel. For these cases in which the damping factor was low, -1/2 or less, the stability was critical and sensitive to disturbance. When the damping factor was about -2, damping was generally obtained.

Factors affecting the stability of viral vaccines.

PubMed

Peetermans, J

1996-01-01

The stability of viral vaccines is determined by the rate of loss of "integrity" of the viral antigen during storage. For live vaccines, such as measles, mumps, rubella, canine distemper, stability is equivalent to the preservation of the infectious titres. For inactivated and subunit vaccines, the preservation of the antigenic structure and the correct steric presentation of the relevant epitopes are the parameters which determine their stability. In general, the following factors may have a negative effect on stability: temperature, pH outside the physiological limits, organic solvents, repeated freezing and thawing, some antiseptics and inactivating agents, and light. However their negative effect is in most cases specific for the individual viruses. Approaches to stabilisation of most vaccines are based on the elimination or neutralisation of the negative factors. Practical examples for the most relevant existing vaccines are described.

[Evaluate the influence of psychosocial factors on sexuality soldiers participating in the Polish Military Contingent in Afghanistan].

PubMed

Brunowski, Jerzy; Florkowski, Antoni; Denys, Katarzyna; Zboralski, Krzysztof

2013-12-01

Sexual health problems of stabilization missions soldiers, contrary to other specific populations, have not been fully studied. However, effects of being in a war zone have been thoroughly investigated. Modern warfare soldier experiences stress related not only to life and health threat but also to separation from loved ones. Anxiety and depression as adaptive disorders, rarer posttraumatic disorder were diagnosed in participants of stabilization missions. These disorders as well as not diagnosed dysfunctions may have impact on sexual health. To assess the selected psychosocial factors on sexuality of veterans of Polish Military Contingent (PMC) in Afghanistan. The study was carried out on 68 soldiers, participants of stabilization mission in Afghanistan. The following diagnostic tools were used: sexual history related to military service specificity was taken, IIEF questionnaire, Mell-Krat Scale for Men, scale of sexual pathology in men, questionnaire: 'Self-esteem on relationship with a partner'. According to the investigated individuals, taking part in a military mission did not increase present or trigger new problems in sex life. The examined soldiers were satisfied with their sexual activity, assessed themselves as good lovers and claimed to be perceived so by their partners. The results of the study show that taking part in Polish Military Contingent seems to have had no negative effect on veterans sex life. Majority of the investigated veterans assessed well the relationship with a wife/partner as well as satisfaction from sexual activity and were aware of being well assessed by a wife/partner with reference to sexual activity.

Stability of Soil Organic Matter in Alpine Ecosystems: No Relationship with Vegetation

NASA Astrophysics Data System (ADS)

Matteodo, M.; Sebag, D.; Vittoz, P.; Verrecchia, E. P.

2016-12-01

There is an emerging understanding of mechanisms governing soil organic matter (SOM) stability, which is challenging the historical view of carbon persistence1. According to this alternative vision, SOM stability is not directly regulated by the molecular structure of plant inputs (i.e. the historical view), but the biotic and abiotic conditions of the surrounding environment which play a major role and mediate the influence of compound chemistry. The persistence of SOM is thus influenced by ecological conditions, controlling the access and activity of decomposers' enzymes and being ecosystem-dependent. In this study, we investigated differences of (1) carbon content, and (2) stability of organic matter in litter and organomineral layers from the most widespread plant communities at the subalpine-alpine level of the Swiss Alps. For this purpose, 230 samples from 47 soil profiles have been analysed across seven plant communities, along a subalpine-alpine elevation gradient. Both calcareous and siliceous grasslands were studied, as well as snowbed and ridge communities. Aboveground litter and A horizons were sampled and analysed using Rock-Eval Pyrolysis, a proxy-technique commonly used for the investigation of organic matter composition and stability2,3. Results show that the litter layers of the seven plant communities are significantly different in terms of total organic carbon (TOC) content, but slightly variable in terms of stability. The situation is radically different in the organomineral horizons where the amount of organic carbon is interestingly homogeneous, as well as the SOM stability. In mineral horizons, the amount and stability of SOM are mainly driven by the geological settings, and therefore vary in the different plant communities. These results show a clear disconnection between organic, organomineral, and mineral horizons in terms of factors governing soil organic matter stability. Consistent with the recent view of the carbon balance, plant input seems to influence the litter C dynamics (qualitatively and quantitatively) but not the SOM stability in A and mineral horizons. References 1Schmidt MWI, et al. (2011) Nature 478, 49-56. 2Disnar JR, et al. (2003) Org. Geochem. 34, 327-343. 3Sebag D, et al. (2006) Eur. J. of Soil Sci. 57, 344-355.

Aging, Atherosclerosis, and IGF-1

PubMed Central

Higashi, Yusuke; Sukhanov, Sergiy; Anwar, Asif; Shai, Shaw-Yung

2012-01-01

Insulin-like growth factor 1 (IGF-1) is an endocrine and autocrine/paracrine growth factor that circulates at high levels in the plasma and is expressed in most cell types. IGF-1 has major effects on development, cell growth and differentiation, and tissue repair. Recent evidence indicates that IGF-1 reduces atherosclerosis burden and improves features of atherosclerotic plaque stability in animal models. Potential mechanisms for this atheroprotective effect include IGF-1–induced reduction in oxidative stress, cell apoptosis, proinflammatory signaling, and endothelial dysfunction. Aging is associated with increased vascular oxidative stress and vascular disease, suggesting that IGF-1 may exert salutary effects on vascular aging processes. In this review, we will provide a comprehensive update on IGF-1's ability to modulate vascular oxidative stress and to limit atherogenesis and the vascular complications of aging. PMID:22491965

Current approach to liver traumas.

PubMed

Kaptanoglu, Levent; Kurt, Necmi; Sikar, Hasan Ediz

2017-03-01

Liver injuries remain major obstacle for successful treatment, due to size and location of the liver. Requirement for surgery should be determined by clinical factors, most notably hemodynamical state. In this present study we tried to declare our approach to liver traumas. We also tried to emphasize the importance of conservative treatment, since surgeries for liver traumas carry high mortality rates. Patients admitted to the Department of Emergency Surgery at Kartal Research and Education Hospital, due to liver trauma were retrospectively analyzed between 2003 and 2013. Patient demographics, hepatic panel, APTT (activated partial thromboplastin time), PT (prothrombin time), INR (international normalized ratio), fibrinogen, biochemistry panel were recorded. Hemodynamic instability was the most prominent factor for surgery decision, in the lead of current Advanced Trauma Life Support (ATLS) protocols. Operation records and imaging modalities revealed liver injuries according to the Organ Injury Scale of the American Association for the Surgery of Trauma. 300 patients admitted to emergency department were included in our study (187 males and 113 females). Mean age was 47 years (range, 12-87). The overall mortality rate was 13% (40 out of 300). Major factor responsible for mortality rates and outcome was stability of cases on admission. 188 (% 63) patients were counted as stable, whereas 112 (% 37) cases were found unstable (blood pressure ≤ 90, after massive resuscitation). 192 patients were observed conservatively, whereas 108 cases received abdominal surgery. High levels of AST, ALT, LDH, INR, creatinine and low levels of fibrinogen and low platelet counts on admission were found to be associated with mortality and these cases also had Grade 4 and 5 injuries. Hemodynamic instability on admission and the type and grade of injury played major role in mortality rates). Packing was performed in 35 patients, with Grade 4 and 5 injuries. Mortality rate was %13 (40 out of 300). A multidisciplinary approach to the management of hepatic injuries has evolved over the last few decades, but the basic principles of trauma continue to be observed. Diagnostic and therapeutic endeavors are chosen based mainly on the stability of the patient. Stable patients with reliable examinations and available resources can be managed nonoperatively. Unstable patients require surgery. Our current approach to liver traumas is non operative technique, if possible. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

The relationship of transversus abdominis and lumbar multifidus activation and prognostic factors for clinical success with a stabilization exercise program: a cross-sectional study.

PubMed

Hebert, Jeffrey J; Koppenhaver, Shane L; Magel, John S; Fritz, Julie M

2010-01-01

Hebert JJ, Koppenhaver SL, Magel JS, Fritz JM. The relationship of transversus abdominis and lumbar multifidus activation and prognostic factors for clinical success with a stabilization exercise program: a cross-sectional study. To examine the relationship between prognostic factors for clinical success with a stabilization exercise program and lumbar multifidus (LM) and transversus abdominis (TrA) muscle activation assessed using rehabilitative ultrasound imaging (RUSI). Cross-sectional study. Outpatient physical therapy clinic. Volunteers with current low back pain (N=40). Not applicable. We examined the relationship between prognostic factors associated with clinical success with a stabilization exercise program (positive prone instability test, age <40y, aberrant movements, straight leg raise >91 degrees , presence of lumbar hypermobility) and degree of TrA and LM muscle activation assessed by RUSI. Significant univariate relationships were identified between LM muscle activation and the number of prognostic factors present (Pearson correlation coefficient [r] =-.558, P=.001), as well as the individual factors of a positive prone instability test (point biserial correlation coefficient [r(pbis)]=.376, P=.018) and segmental hypermobility (r(pbis)=.358, P=.025). The multivariate analyses indicated that after controlling for other variables, the addition of the variable "number of prognostic factors present" resulted in a significant increase in R(2) (P=.006). No significant univariate or multivariate relationships were observed between the prognostic factors and TrA muscle activation. Decreased LM muscle activation, but not TrA muscle activation, is associated with the presence of factors predictive of clinical success with a stabilization exercise program. Our findings provide researchers and clinicians with evidence regarding the construct validity of the prognostic factors examined in this study, as well as the potential clinical importance of the LM muscle as a target for stabilization exercises. Copyright (c) 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Stability-Derivative Determination from Flight Data

NASA Technical Reports Server (NTRS)

Holowicz, Chester H.; Holleman, Euclid C.

1958-01-01

A comprehensive discussion of the various factors affecting the determination of stability and control derivatives from flight data is presented based on the experience of the NASA High-Speed Flight Station. Factors relating to test techniques, determination of mass characteristics, instrumentation, and methods of analysis are discussed. For most longitudinal-stability-derivative analyses simple equations utilizing period and damping have been found to be as satisfactory as more comprehensive methods. The graphical time-vector method has been the basis of lateral-derivative analysis, although simple approximate methods can be useful If applied with caution. Control effectiveness has been generally obtained by relating the peak acceleration to the rapid control input, and consideration must be given to aerodynamic contributions if reasonable accuracy is to be realized.. Because of the many factors involved In the determination of stability derivatives, It is believed that the primary stability and control derivatives are probably accurate to within 10 to 25 percent, depending upon the specific derivative. Static-stability derivatives at low angle of attack show the greatest accuracy.

Calculating the wind energy input to a system using a spatially explicit method that considers atmospheric stability

EPA Science Inventory

Atmospheric stability has a major effect in determining the wind energy doing work in the atmospheric boundary layer (ABL); however, it is seldom considered in determining this value in emergy analyses. One reason that atmospheric stability is not usually considered is that a sui...

Using foamed asphalt as a stabilizing agent in full depth reclamation of Route 8 in Belgrade : final report.

DOT National Transportation Integrated Search

2009-03-01

Maine has a variety of soil types throughout the state. A majority of these soil types degrade rapidly and : have poor stability. To eliminate the cost of supplying quality road base material from a distant source and : increase the stability of exis...

Investigating the effect of mutation on the thermo stability of GB1 protein

NASA Astrophysics Data System (ADS)

Sawitri, K. N.; Sumaryada, T.; Ambarsari, L.; Wahyudi, S. T.

2018-04-01

The thermo stability of wild-type and mutants of the B1 domain of Protein G (GB1 protein) have been studied using molecular dynamics simulation and free energy perturbation simulation. This research is aimed to examine what residue or what interaction that has a major role in the thermo stability of GB1 protein thermo stability by using the point mutation method. Based on the analysis, the unfolding of wild-type protein occurred in 500 K simulation at 704 ps. The mutations were chosen based on the changes in some analysis parameters and the calculated net solvation free energy change. It was found that a simple replacement of a positively charged residue in the β-sheet (K4S) decreases the stability of GB1 protein (unfolding at 452 ps), while the replacement of a negatively charged residue in the α-helix (E27G) increases the stability (unfolding at 846 ps). It was also found that the K4A mutation will break the α-helix and all β-sheet into the coil and turn. All those results suggest that the non-bonded interaction has the major role in the thermo stability of GB1 protein with the β-sheets were identified as the most important structure in the thermo stability of GB1 protein..

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

Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H.

Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts andmore » the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs.« less

Research on graphite reinforced glass matrix composites

NASA Technical Reports Server (NTRS)

Prewo, K. M.; Thompson, E. R.

1980-01-01

High levels of mechanical performance in tension, flexure, fatigue, and creep loading situations of graphite fiber reinforced glass matrix composites are discussed. At test temperatures of up to 813 K it was found that the major limiting factor was the oxidative instability of the reinforcing graphite fibers. Particular points to note include the following: (1) a wide variety of graphite fibers were found to be comparable with the glass matrix composite fabrication process; (2) choice of fiber, to a large extent, controlled resultant composite performance; (3) composite fatigue performance was found to be excellent at both 300 K and 703 K; (4) composite creep and stress rupture at temperatures of up to 813 K was limited by the oxidative stability of the fiber; (5) exceptionally low values of composite thermal expansion coefficient were attributable to the dimensional stability of both matrix and fiber; and (6) component fabricability was demonstrated through the hot pressing of hot sections and brazing using glass and metal joining phases.

Beam-beam interaction study of medium energy eRHIC

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

Hao,Y.; Litvinenko, V. N.; Ptitsyn, V.

Medium Energy eRHIC (MeRHIC), the first stage design of eRHIC, includes a multi-pass ERL that provides 4GeV high quality electron beam to collide with the ion beam of RHIC. It delivers a minimum luminosity of 10{sup 32} cm{sup -2}s{sup -1}. Beam-beam effects present one of major factors limiting the luminosity of colliders. In this paper, both beam-beam effects on the electron beam and the proton beam in MeRHIC are investigated. The beam-beam interaction can induce a head-tail type instability of the proton beam referred to as the kink instability. Thus, beam stability conditions should be established to avoid proton beammore » loss. Also, the electron beam transverse disruption by collisions has to be evaluated to ensure that the beam quality is good enough for the energy recovery pass. The relation of proton beam stability, electron disruption and consequential luminosity are carried out after thorough discussion.« less

Characterization of Arbequina virgin olive oils produced in different regions of Brazil and Spain: Physicochemical properties, oxidative stability and fatty acid profile.

PubMed

Borges, Thays H; Pereira, José Alberto; Cabrera-Vique, Carmen; Lara, Luis; Oliveira, Adelson F; Seiquer, Isabel

2017-01-15

Production of virgin olive oil is beginning in Brazil. This paper analyzes the characteristics of the EVOO Arbequina from Brazil in comparison with Spanish Arbequina from different regions. Quality parameters, oxidative stability, pigments, colour and fatty acid profile were assessed, and relationships with geographic and climatic conditions were studied. All the samples presented good quality and met EU standards for extra-virgin olive oil, but there were significant differences between regions and countries for many of the parameters evaluated. Major differences between Brazilian and Spanish samples were observed for free acidity and colour of the oils, as well as minor variations in the fatty acid profile. The colour differences were related to rainfall, whereas the fatty acid content was strongly influenced by altitude and temperature. These results highlight the fact that geographic area and environmental factors influence the characteristics of Arbequina oil and play an important role in newly introduced cultivars. Copyright © 2016 Elsevier Ltd. All rights reserved.

New procyanidin B3-human salivary protein complexes by mass spectrometry. Effect of salivary protein profile, tannin concentration, and time stability.

PubMed

Perez-Gregorio, Maria Rosa; Mateus, Nuno; De Freitas, Victor

2014-10-15

Several factors could influence the tannin-protein interaction such as the human salivary protein profile, the tannin tested, and the tannin/protein ratio. The goal of this study aims to study the effect of different salivas (A, B, and C) and different tannin concentrations (0.5 and 1 mg/mL) on the interaction process as well as the complex's stability over time. This study is focused on the identification of new procyanidin B3-human salivary protein complexes. Thus, 48 major B3-human salivary protein aggregates were identified regardless of the saliva and tannin concentration tested. A higher number of aggregates was found at lower tannin concentration. Moreover, the number of protein moieties involved in the aggregation process was higher when the tannin concentration was also higher. The selectivity of the different groups of proteins to bind tannin was also confirmed. It was also verified that the B3-human salivary protein complexes formed evolved over time.

Design of minocycline-containing starch nanocapsules for topical delivery.

PubMed

Marto, J; Gouveia, L F; Gonçalves, L M; Ribeiro, H M; Almeida, A J

2018-06-11

Pharmaceutical research has been focused on developing improved delivery systems while exploring new ways of using approved excipients. The present work investigated the potential of starch nanocapsules (StNC) as a topical delivery platform for hydrophilic antimicrobial drugs using minocycline hydrochloride (MH) as a model drug. Thus, a quality by design approach was used to assess the role of different factors that affect the main pharmaceutical properties of StNC prepared using an emulsification-solvent evaporation method. Full characterization was performed in terms of particle size, encapsulation efficiency, morphology and physical stability at 5 ± 3°C. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. The MH loading only promoted minor changes upon StNC properties. Formulations were stable without variations on physicochemical properties. All tested formulations presented a zeta potential of +33.6±6.7 mV, indicating a good physical stability and evidencing that StNC are suitable nanocarriers for topical use.

Three strategies to stabilise nearly monodispersed silver nanoparticles in aqueous solution

NASA Astrophysics Data System (ADS)

Stevenson, Amadeus PZ; Blanco Bea, Duani; Civit, Sergi; Antoranz Contera, Sonia; Iglesias Cerveto, Alberto; Trigueros, Sonia

2012-02-01

Silver nanoparticles are extensively used due to their chemical and physical properties and promising applications in areas such as medicine and electronics. Controlled synthesis of silver nanoparticles remains a major challenge due to the difficulty in producing long-term stable particles of the same size and shape in aqueous solution. To address this problem, we examine three strategies to stabilise aqueous solutions of 15 nm citrate-reduced silver nanoparticles using organic polymeric capping, bimetallic core-shell and bimetallic alloying. Our results show that these strategies drastically improve nanoparticle stability by distinct mechanisms. Additionally, we report a new role of polymer functionalisation in preventing further uncontrolled nanoparticle growth. For bimetallic nanoparticles, we attribute the presence of a higher valence metal on the surface of the nanoparticle as one of the key factors for improving their long-term stability. Stable silver-based nanoparticles, free of organic solvents, will have great potential for accelerating further environmental and nanotoxicity studies. PACS: 81.07.-b; 81.16.Be; 82.70.Dd.

Effective Factors in Marital Satisfaction in Perspective of Iranian Women and Men: A systematic review.

PubMed

Zaheri, Farzaneh; Dolatian, Mahrokh; Shariati, Mohammad; Simbar, Masoomeh; Ebadi, Abbas; Azghadi, Seyede Batool Hasanpoor

2016-12-01

One of the most important factors and determinants of mental health, emotional stability of couples and successful marriage is marital satisfaction, a state that in most cases, males and females are satisfied with each other and their marriage. This review was conducted to survey the effective factors on marital satisfaction in view of Iranian men and women. This systematic review surveys published articles from 2005 to 2015. First, scientific databases such as Pubmed/Medline, Scopus, Elsevier, Cochran library, Springer, Scientific Information Database (SID), IranMedex, Magiran and Medlib were searched using relevant key words and phrases. All published peer-reviewed articles studied exploring associations between marital satisfaction and effective factors were considered for inclusion. According to results, the spiritual and religious, sexual and interpersonal factors, communication and interaction factors and mental health had positive impact on marital satisfaction in the vast majority of studies. Also in most articles, impact of some socio-demographic factors such as occupation, length of marriage, age, Number of children, economic factor and income had been emphasized. In mate selection, it is necessary to note various criteria, including religious matters, moral, mental health, communication skills and sexual factor and action through education, counseling and treatment if there is problem.

Effective Factors in Marital Satisfaction in Perspective of Iranian Women and Men: A systematic review

PubMed Central

Zaheri, Farzaneh; Dolatian, Mahrokh; Shariati, Mohammad; Simbar, Masoomeh; Ebadi, Abbas; Azghadi, Seyede Batool Hasanpoor

2016-01-01

Introduction One of the most important factors and determinants of mental health, emotional stability of couples and successful marriage is marital satisfaction, a state that in most cases, males and females are satisfied with each other and their marriage. This review was conducted to survey the effective factors on marital satisfaction in view of Iranian men and women. Methods This systematic review surveys published articles from 2005 to 2015. First, scientific databases such as Pubmed/Medline, Scopus, Elsevier, Cochran library, Springer, Scientific Information Database (SID), IranMedex, Magiran and Medlib were searched using relevant key words and phrases. All published peer-reviewed articles studied exploring associations between marital satisfaction and effective factors were considered for inclusion. Results According to results, the spiritual and religious, sexual and interpersonal factors, communication and interaction factors and mental health had positive impact on marital satisfaction in the vast majority of studies. Also in most articles, impact of some socio-demographic factors such as occupation, length of marriage, age, Number of children, economic factor and income had been emphasized. Conclusion In mate selection, it is necessary to note various criteria, including religious matters, moral, mental health, communication skills and sexual factor and action through education, counseling and treatment if there is problem. PMID:28163850

Random matrix theory filters in portfolio optimisation: A stability and risk assessment

NASA Astrophysics Data System (ADS)

Daly, J.; Crane, M.; Ruskin, H. J.

2008-07-01

Random matrix theory (RMT) filters, applied to covariance matrices of financial returns, have recently been shown to offer improvements to the optimisation of stock portfolios. This paper studies the effect of three RMT filters on the realised portfolio risk, and on the stability of the filtered covariance matrix, using bootstrap analysis and out-of-sample testing. We propose an extension to an existing RMT filter, (based on Krzanowski stability), which is observed to reduce risk and increase stability, when compared to other RMT filters tested. We also study a scheme for filtering the covariance matrix directly, as opposed to the standard method of filtering correlation, where the latter is found to lower the realised risk, on average, by up to 6.7%. We consider both equally and exponentially weighted covariance matrices in our analysis, and observe that the overall best method out-of-sample was that of the exponentially weighted covariance, with our Krzanowski stability-based filter applied to the correlation matrix. We also find that the optimal out-of-sample decay factors, for both filtered and unfiltered forecasts, were higher than those suggested by Riskmetrics [J.P. Morgan, Reuters, Riskmetrics technical document, Technical Report, 1996. http://www.riskmetrics.com/techdoc.html], with those for the latter approaching a value of α=1. In conclusion, RMT filtering reduced the realised risk, on average, and in the majority of cases when tested out-of-sample, but increased the realised risk on a marked number of individual days-in some cases more than doubling it.

HSF1 phosphorylation by ERK/GSK3 suppresses RNF126 to sustain IGF-IIR expression for hypertension-induced cardiomyocyte hypertrophy.

PubMed

Huang, Chih-Yang; Lee, Fa-Lun; Peng, Shu-Fen; Lin, Kuan-Ho; Chen, Ray-Jade; Ho, Tsung-Jung; Tsai, Fu-Jen; Padma, Vijaya V; Kuo, Wei-Wen; Huang, Chih-Yang

2018-02-01

Hypertension-induced cardiac hypertrophy and apoptosis are major characteristics of early-stage heart failure (HF). Inhibition of extracellular signal-regulated kinases (ERK) efficaciously suppressed angiotensin II (ANG II)-induced cardiomyocyte hypertrophy and apoptosis by blocking insulin-like growth factor II receptor (IGF-IIR) signaling. However, the detailed mechanism by which ANG II induces ERK-mediated IGF-IIR signaling remains elusive. Here, we found that ANG II activated ERK to upregulate IGF-IIR expression via the angiotensin II type I receptor (AT 1 R). ERK activation subsequently phosphorylates HSF1 at serine 307, leading to a secondary phosphorylation by glycogen synthase kinase III (GSK3) at serine 303. Moreover, we found that ANG II mediated ERK/GSK3-induced IGF-IIR protein stability by downregulating the E3 ubiquitin ligase of IGF-IIR RING finger protein CXXVI (RNF126). The expression of RNF126 decreased following ANG II-induced HSF1 S303 phosphorylation, resulting in IGF-IIR protein stability and increased cardiomyocyte injury. Inhibition of GSK3 significantly alleviated ANG II-induced cardiac hypertrophy in vivo and in vitro. Taken together, these results suggest that HSF1 phosphorylation stabilizes IGF-IIR protein stability by downregulating RNF126 during cardiac hypertrophy. ANG II activates ERK/GSK3 to phosphorylate HSF1, resulting in RNF126 degradation, which stabilizes IGF-IIR protein expression and eventually results in cardiac hypertrophy. HSF1 could be a valuable therapeutic target for cardiac diseases among hypertensive patients. © 2017 Wiley Periodicals, Inc.

[Impacts of hydroelectric cascade exploitation on river ecosystem and landscape: a review].

PubMed

Yang, Kun; Deng, Xi; Li, Xue-Ling; Wen, Ping

2011-05-01

Hydroelectric cascade exploitation, one of the major ways for exploiting water resources and developing hydropower, not only satisfies the needs of various national economic sectors, but also promotes the socio-economic sustainable development of river basin. unavoidable anthropogenic impacts on the entire basin ecosystem. Based on the process of hydroelectric cascade exploitation and the ecological characteristics of river basins, this paper reviewed the major impacts of hydroelectric cascade exploitation on dam-area ecosystems, river reservoirs micro-climate, riparian ecosystems, river aquatic ecosystems, wetlands, and river landscapes. Some prospects for future research were offered, e.g., strengthening the research of chain reactions and cumulative effects of ecological factors affected by hydroelectric cascade exploitation, intensifying the study of positive and negative ecological effects under the dam networks and their joint operations, and improving the research of successional development and stability of basin ecosystems at different temporal and spatial scales.

[Haiti, new immigrant community in Chile].

PubMed

Sánchez P, Katherin; Valderas J, Jaime; Messenger C, Karen; Sánchez G, Carolina; Barrera Q, Francisco

2018-04-01

Migration is a growing phenomenon in Latin America influenced by several factors such as economic stability, employment, social welfare, education and health system. Currently Chile has a positive migration flow rate. Particularly, a significant number of Haitian immigrants has been observed du ring the last years, especially after earthquake of 2010. These immigrants present a different cultural background expressed in relevant aspects of living including parenting and healthcare. Knowing the Haitian culture and its health situation is relevant for a better understanding of their health needs. Haitian people come to Chile looking for a cordial reception and willing to find a place with better perspectives of wellbeing in every sense. Immigration represents a major challenge for Chilean health system that must be embraced. Integration efforts in jobs, health, education system and community living should be enhanced to ensure a prosper settlement in our country. A new immigration law is crucial to solving major problems derived from current law created in 1975.

Temporal Stability of DSM-5 Posttraumatic Stress Disorder Criteria in a Problem Drinking Sample

PubMed Central

Keane, Terence M.; Rubin, Amy; Lachowicz, Mark; Brief, Deborah; Enggasser, Justin L.; Roy, Monica; Hermos, John; Helmuth, Eric; Rosenbloom, David

2014-01-01

The Diagnostic and Statistical Manual-5 (DSM-5) reformulated Posttraumatic Stress Disorder (PTSD) based partially on research showing there were four main factors that underlie the symptoms of the disorder. The primary aim of this study was to examine the temporal stability of the DSM-5 factors as measured by the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5; Weathers et al., 2010). Confirmatory factor analyses were conducted to examine the structure of DSM-5 PTSD, and temporal stability over three time points was examined to determine if the measure reflects a consistent construct over time. Our sample was 507 combat-exposed veterans of Iraq and Afghanistan who enrolled in an online intervention for problem drinking and combat-related stress (masked for review). We administered the PCL-5 at baseline, 8-week post intervention, and 3-month follow-up assessments. The DSM-5 model provided an adequate fit to the data at baseline. Tests of equality of form and equality of factor loadings demonstrated stability of the factor structure over time, indicating temporal stability. This study confirms the results of previous research supporting the DSM-5 model of PTSD symptoms (Elhai et al., 2012; Miller et al., 2012). This is the first study to demonstrate the temporal stability of the PCL-5, indicating its use in longitudinal studies will measure the same construct over time. PMID:24932642

Protective Factors for Youth Exposed to Violence in Their Communities: A Review of Family, School, and Community Moderators.

PubMed

Ozer, Emily J; Lavi, Iris; Douglas, Laura; Wolf, Jennifer Price

2017-01-01

This review provides a comprehensive investigation of the pattern and strength of findings in the literature regarding the environmental moderators of the relationship between exposure to community violence and mental health among children and adolescents. Twenty-nine studies met criteria for inclusion in our analysis of family, school, and community variables as moderators. Dependent variables included internalizing (e.g., anxiety, depression, posttraumatic stress disorder) and externalizing symptoms (e.g., aggression, substance use). Effect sizes for the interactions of exposure to violence and potential moderators were summarized by their patterns of protective processes. The majority of studies in the literature examined family characteristics as moderators of the exposure to violence-symptom relationship, rather than school- or community-level factors. Our results indicated more consistent patterns for (a) close family relationships and social support for internalizing symptoms and (b) close family relationships for externalizing symptoms. Overall, the most common type of protective pattern was protective-stabilizing, in which youth with higher levels of the environmental attribute demonstrate relative stability in mental health despite exposure to violence. We found no consistent evidence that parental monitoring-a dimension inversely associated with exposure to violence in prior studies-moderated the relationship between exposure to violence and symptoms. The study emphasizes the importance of strengthening family support for young people's exposure to community violence; more research is needed to provide a solid evidence base for the role of school and community-level protective factors for youth exposed to violence.

Stability of parental understanding of random assignment in childhood leukemia trials: an empirical examination of informed consent.

PubMed

Greenley, Rachel Neff; Drotar, Dennis; Zyzanski, Stephen J; Kodish, Eric

2006-02-20

To examine stability versus change in parental understanding of random assignment in randomized clinical trials (RCTs) for pediatric leukemia and to identify factors associated with changes in understanding. Eighty-four parents of children diagnosed with acute lymphoblastic leukemia or acute myeloid leukemia who were enrolled onto a pediatric leukemia RCT at one of six US children's hospitals participated. Parents were interviewed twice, once within 48 hours after the Informed Consent Conference (ICC; time 1 [T1]) and again 6 months later (time 2 [T2]). Interviews focused on parental understanding of key components of the RCT, including random assignment. Interviews were audiotaped, transcribed, and later analyzed. Changes in understanding of random assignment occurred in 19% of parents, with 17% of parents deteriorating in understanding from T1 to T2. Forty-nine percent of parents failed to understand random assignment at both times. Factors associated with understanding at both times included majority ethnicity, high socioeconomic status, parental reading of consent document, and presence of a nurse during the ICC. Physician discussion of specific components of the RCT was also associated with understanding at both times. Female caregivers and parents of low socioeconomic status were overrepresented among those who showed decay in understanding from T1 to T2. Parents showed little gain in understanding over time. Factors that predicted understanding at diagnosis as well as sustained understanding over time may be important intervention targets. Attention to both modifiable and nonmodifiable barriers is important for clinical practice.

The regulation of trefoil factor 2 expression by the transcription factor Sp3.

PubMed

Liu, Jingjing; Wang, Xu; Cai, Yiling; Zhou, Jingping; Guleng, Bayasi; Shi, Huaxiu; Ren, Jianlin

2012-10-19

Trefoil factor family 2 (TFF2) participates in mucus stabilization and repair, apoptosis, and inflammatory responses. Previously published reports have indicated that several growth factors and basal transcription factors are associated with the expression of TFF2. However, the detailed mechanisms that regulate TFF2 expression are not fully understood. The present study was designed to assess the essential role of the transcription factor SP3 with respect to TFF2 expression. We first demonstrated that there was a negative correlation between the expression levels of SP3 and TFF2. Thus, in the examined cells, the overexpression of SP3 decreased the expression level of TFF2, whereas the inhibition of SP3 increased the expression level of TFF2. Moreover, we discovered two GC boxes in the TFF2 promoter and confirmed the specific binding of SP3 to this promoter. On the whole, this study indicated that Sp3 was a major regulator of TFF2 expression. This knowledge should contribute to our understanding of the role that is played by SP3 in the regulation of TFF2 expression. Copyright © 2012 Elsevier Inc. All rights reserved.

Factors affecting fixation of heavy metals in solidified/stabilized matrix: a review.

PubMed

Malviya, Rachana; Chaudhary, Rubina

2010-07-01

In this paper, an effort has been made to understand the factors, which affect fixation of heavy metals in solidified/stabilized matrix. Various aspects related to the solidification/stabilization of different heavy metals (Ar, Ba, Cu, Cr, Pb, Zn, Hg) are reviewed. A comparative study of different binders for the fixation of each metal has also been carried out to suggest the most suitable binder, pretreatment required for the metal. Valence, speciation, pH and other factors are also considered while reviewing metal retention capacity of different matrix.

The Impact of Microbiota-Gut-Brain Axis on Diabetic Cognition Impairment

PubMed Central

Xu, Youhua; Zhou, Hua; Zhu, Quan

2017-01-01

Progressive cognitive dysfunction is a central characteristic of diabetic encephalopathy (DE). With an aging population, the incidence of DE is rising and it has become a major threat that seriously affects public health. Studies within this decade have indicated the important role of risk factors such as oxidative stress and inflammation on the development of cognitive impairment. With the recognition of the two-way communication between gut and brain, recent investigation suggests that “microbiota-gut-brain axis” also plays a pivotal role in modulating both cognition function and endocrine stability. This review aims to systemically elucidate the underlying impact of diabetes on cognitive impairment. PMID:28496408

From structure to mechanism—understanding initiation of DNA replication

PubMed Central

Riera, Alberto; Barbon, Marta; Noguchi, Yasunori; Reuter, L. Maximilian; Schneider, Sarah; Speck, Christian

2017-01-01

DNA replication results in the doubling of the genome prior to cell division. This process requires the assembly of 50 or more protein factors into a replication fork. Here, we review recent structural and biochemical insights that start to explain how specific proteins recognize DNA replication origins, load the replicative helicase on DNA, unwind DNA, synthesize new DNA strands, and reassemble chromatin. We focus on the minichromosome maintenance (MCM2–7) proteins, which form the core of the eukaryotic replication fork, as this complex undergoes major structural rearrangements in order to engage with DNA, regulate its DNA-unwinding activity, and maintain genome stability. PMID:28717046

Corrigendum

NASA Astrophysics Data System (ADS)

Faghihi, M.; Scheffel, J.

1988-12-01

A minor correction, having no major influence on our results, is reported here. The coefficients in the equations of state (16) and (17) should read The set of equations (13)-(20) now comprise the correct, linearized and Fourierdecomposed double adiabatic equations in cylindrical geometry. In addition, there is a printing error in (15): a factor bz should multiply the last term of the left-hand side. Our results are only slightly modified, and the discussion remains unchanged. We wish, however, to point out that the correct stability criterion for isotropic pressure, (26), should be This is the double adiabatic counterpart to the m ╪ 0 Kadomtsev criterion of ideal MHD.

Macrophage cell lines derived from major histocompatibility complex II-negative mice

NASA Technical Reports Server (NTRS)

Beharka, A. A.; Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1998-01-01

Two bone-marrow-derived macrophage cell lines, C2D and C2Dt, were isolated from major histocompatibility class II negative knock-out mice. The C2D cell line was stabilized by continuous culture in colony-stimulating factor-1 and the C2Dt cell line was transformed with SV40 virus large T antigen. These cells exhibited phenotypic properties of macrophages including morphology and expression of Mac 1 and Mac 2 cell surface molecules. These cells also had comparable growth to the bone-marrow-derived macrophage cell line B6MP102. These new cell lines were not spontaneously cytotoxic and were only capable of modest killing of F5b tumor cells when stimulated with LPS and interferon-gamma, but not when stimulated with LPS alone or with staphylococcal exotoxin. C2D and C2Dt cells phagocytosed labeled Staphylococcus aureus similarly to B6MP102 cells but less well than C2D peritoneal macrophages. These cell lines secreted interleukin-6, but not tumor necrosis factor or nitric oxide in response to LPS or staphlococcal enterotoxins A or B C2D(t) cells were tumorigenic in C2D and C57BL/6J mice but C2D cells were not. These data suggest that macrophage cell lines can be established from bone marrow cells of major histocompatibility complex II-negative mice.

Applying the methodology of Design of Experiments to stability studies: a Partial Least Squares approach for evaluation of drug stability.

PubMed

Jordan, Nika; Zakrajšek, Jure; Bohanec, Simona; Roškar, Robert; Grabnar, Iztok

2018-05-01

The aim of the present research is to show that the methodology of Design of Experiments can be applied to stability data evaluation, as they can be seen as multi-factor and multi-level experimental designs. Linear regression analysis is usually an approach for analyzing stability data, but multivariate statistical methods could also be used to assess drug stability during the development phase. Data from a stability study for a pharmaceutical product with hydrochlorothiazide (HCTZ) as an unstable drug substance was used as a case example in this paper. The design space of the stability study was modeled using Umetrics MODDE 10.1 software. We showed that a Partial Least Squares model could be used for a multi-dimensional presentation of all data generated in a stability study and for determination of the relationship among factors that influence drug stability. It might also be used for stability predictions and potentially for the optimization of the extent of stability testing needed to determine shelf life and storage conditions, which would be time and cost-effective for the pharmaceutical industry.

Optimal exploitation of spatially distributed trophic resources and population stability

USGS Publications Warehouse

Basset, A.; Fedele, M.; DeAngelis, D.L.

2002-01-01

The relationships between optimal foraging of individuals and population stability are addressed by testing, with a spatially explicit model, the effect of patch departure behaviour on individual energetics and population stability. A factorial experimental design was used to analyse the relevance of the behavioural factor in relation to three factors that are known to affect individual energetics; i.e. resource growth rate (RGR), assimilation efficiency (AE), and body size of individuals. The factorial combination of these factors produced 432 cases, and 1000 replicate simulations were run for each case. Net energy intake rates of the modelled consumers increased with increasing RGR, consumer AE, and consumer body size, as expected. Moreover, through their patch departure behaviour, by selecting the resource level at which they departed from the patch, individuals managed to substantially increase their net energy intake rates. Population stability was also affected by the behavioural factors and by the other factors, but with highly non-linear responses. Whenever resources were limiting for the consumers because of low RGR, large individual body size or low AE, population density at the equilibrium was directly related to the patch departure behaviour; on the other hand, optimal patch departure behaviour, which maximised the net energy intake at the individual level, had a negative influence on population stability whenever resource availability was high for the consumers. The consumer growth rate (r) and numerical dynamics, as well as the spatial and temporal fluctuations of resource density, which were the proximate causes of population stability or instability, were affected by the behavioural factor as strongly or even more strongly than by the others factors considered here. Therefore, patch departure behaviour can act as a feedback control of individual energetics, allowing consumers to optimise a potential trade-off between short-term individual fitness and long-term population stability. ?? 2002 Elsevier Science B.V. All rights reserved.

Evaluating the effects of buffer conditions and extremolytes on thermostability of granulocyte colony-stimulating factor using high-throughput screening combined with design of experiments.

PubMed

Ablinger, Elisabeth; Hellweger, Monika; Leitgeb, Stefan; Zimmer, Andreas

2012-10-15

In this study, we combined a high-throughput screening method, differential scanning fluorimetry (DSF), with design of experiments (DoE) methodology to evaluate the effects of several formulation components on the thermostability of granulocyte colony stimulating factor (G-CSF). First we performed a primary buffer screening where we tested thermal stability of G-CSF in different buffers, pH values and buffer concentrations. The significance of each factor and the two-way interactions between them were studied by multivariable regression analysis. pH was identified as most critical factor regarding thermal stability. The most stabilizing buffer, sodium glutamate, and sodium acetate were determined for further investigations. Second we tested the effect of 6 naturally occurring extremolytes (trehalose, sucrose, ectoine, hydroxyectoine, sorbitol, mannitol) on the thermal stability of G-CSF, using a central composite circumscribed design. At low pH (3.8) and low buffer concentration (5 mM) all extremolytes led to a significant increase in thermal stability except the addition of ectoine which resulted in a strong destabilization of G-CSF. Increasing pH and buffer concentration led to an increase in thermal stability with all investigated extremolytes. The described systematic approach allowed to create a ranking of stabilizing extremolytes at different buffer conditions. Copyright © 2012. Published by Elsevier B.V.

The sensitivity of tokamak magnetohydrodynamics stability on the edge equilibrium

NASA Astrophysics Data System (ADS)

Zheng, L. J.; Kotschenreuther, M. T.; Valanju, P.

2017-10-01

Due to the X-point singularity, the safety factor tends to infinity as approaching to the last closed flux surface. The numerical treatments of the near X-point behavior become challenging both for equilibrium and stability. The usual solution is to cut off a small fraction of edge region for system stability evaluation or simply use an up-down symmetric equilibrium without X-point as an approximation. In this work, we assess the sensitivity of this type of equilibrium treatments on the stability calculation. It is found that the system stability can depend strongly on the safety factor value (qa) at the edge after the cutting-off. When the edge safety factor value falls in the vicinity of a rational mode number (referred to as the resonant gap), the system becomes quite unstable due to the excitation of the peeling type modes. Instead, when the edge safety factor is outside the resonant gaps, the system is much more stable and the predominant modes become the usual external kink (or ballooning and infernal) type. It is also found that the resonant gaps become smaller and smaller as qa increases. The ideal magnetohydrodynamic peeling ballooning stability diagram is widely used to explain the experimental observations, and the current results indicate that the conventional peeling ballooning stability diagram based on the simplified equilibrium needs to be reexamined.

Development of LRFD resistance factors for mechanically stabilized earth (MSE) walls : [technical summary].

DOT National Transportation Integrated Search

2013-12-01

Bridge approach embankments and many other : transportation-related applications make use of : reinforced earth retaining structures. Mechanically : Stabilized Earth (MSE) walls are designed under : the Load and Resistance Factor Design (LRFD) : meth...

Real-time black carbon emission factor measurements from light duty vehicles.

PubMed

Forestieri, Sara D; Collier, Sonya; Kuwayama, Toshihiro; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D

2013-11-19

Eight light-duty gasoline low emission vehicles (LEV I) were tested on a Chassis dynamometer using the California Unified Cycle (UC) at the Haagen-Smit vehicle test facility at the California Air Resources Board in El Monte, CA during September 2011. The UC includes a cold start phase followed by a hot stabilized running phase. In addition, a light-duty gasoline LEV vehicle and ultralow emission vehicle (ULEV), and a light-duty diesel passenger vehicle and gasoline direct injection (GDI) vehicle were tested on a constant velocity driving cycle. A variety of instruments with response times ≥0.1 Hz were used to characterize how the emissions of the major particulate matter components varied for the LEVs during a typical driving cycle. This study focuses primarily on emissions of black carbon (BC). These measurements allowed for the determination of BC emission factors throughout the driving cycle, providing insights into the temporal variability of BC emission factors during different phases of a typical driving cycle.

The Role of Neurotrophins in Major Depressive Disorder.

PubMed

Jiang, Cheng; Salton, Stephen R

2013-03-01

Neurotrophins and other growth factors have been advanced as critical modulators of depressive behavior. Support for this model is based on analyses of knockout and transgenic mouse models, human genetic studies, and screens for gene products that are regulated by depressive behavior and/or antidepressants. Even subtle alteration in the regulated secretion of brain-derived neurotrophic factor (BDNF), for example, due to a single nucleotide polymorphism (SNP)-encoded Val-Met substitution in proBDNF that affects processing and sorting, impacts behavior and cognition. Alterations in growth factor expression result in changes in neurogenesis as well as structural changes in neuronal cytoarchitecture, including effects on dendritic length and spine density, in the hippocampus, nucleus accumbens, and prefrontal cortex. These changes have the potential to impact the plasticity and stability of synapses in the CNS, and the complex brain circuitry that regulates behavior. Here we review the role that neurotrophins play in the modulation of depressive behavior, and the downstream signaling targets they regulate that potentially mediate these behavioral pro-depressant and antidepressant effects.

The Role of Neurotrophins in Major Depressive Disorder

PubMed Central

Jiang, Cheng; Salton, Stephen R.

2013-01-01

Neurotrophins and other growth factors have been advanced as critical modulators of depressive behavior. Support for this model is based on analyses of knockout and transgenic mouse models, human genetic studies, and screens for gene products that are regulated by depressive behavior and/or antidepressants. Even subtle alteration in the regulated secretion of brain-derived neurotrophic factor (BDNF), for example, due to a single nucleotide polymorphism (SNP)-encoded Val-Met substitution in proBDNF that affects processing and sorting, impacts behavior and cognition. Alterations in growth factor expression result in changes in neurogenesis as well as structural changes in neuronal cytoarchitecture, including effects on dendritic length and spine density, in the hippocampus, nucleus accumbens, and prefrontal cortex. These changes have the potential to impact the plasticity and stability of synapses in the CNS, and the complex brain circuitry that regulates behavior. Here we review the role that neurotrophins play in the modulation of depressive behavior, and the downstream signaling targets they regulate that potentially mediate these behavioral pro-depressant and antidepressant effects. PMID:23691270

Estimation of Directional Stability Derivatives at Moderate Angles and Supersonic Speeds

NASA Technical Reports Server (NTRS)

Kaattari, George E.

1959-01-01

A study of some of the important aerodynamic factors affecting the directional stability of supersonic airplanes is presented. The mutual interference fields between the body, the lifting surfaces, and the stabilizing surfaces are analyzed in detail. Evaluation of these interference fields on an approximate theoretical basis leads to a method for predicting directional stability of supersonic airplanes. Body shape, wing position and plan form, vertical tail position and plan form, and ventral fins are taken into account. Estimates of the effects of these factors are in fair agreement with experiment.

Biologics formulation factors affecting metal leachables from stainless steel.

PubMed

Zhou, Shuxia; Schöneich, Christian; Singh, Satish K

2011-03-01

An area of increasing concern and scientific scrutiny is the potential contamination of drug products by leachables entering the product during manufacturing and storage. These contaminants may either have a direct safety impact on the patients or act indirectly through the alteration of the physicochemical properties of the product. In the case of biotherapeutics, trace amounts of metal contaminants can arise from various sources, but mainly from contact with stainless steel (ss). The effect of the various factors, buffer species, solution fill volume per unit contact surface area, metal chelators, and pH, on metal leachables from contact with ss over time were investigated individually. Three major metal leachables, iron, chromium, and nickel, were monitored by inductively coupled plasma-mass spectrometry because they are the major components of 316L ss. Iron was primarily used to evaluate the effect of each factor since it is the most abundant. It was observed that each studied factor exhibited its own effect on metal leachables from contact with ss. The effect of buffer species and pH exhibited temperature dependence over the studied temperature range. The metal leachables decreased with the increased fill volume (mL) per unit contact ss surface area (cm(2)) but a plateau was achieved at approximately 3 mL/cm(2). Metal chelators produced the strongest effect in facilitating metal leaching. In order to minimize the metal leachables and optimize biological product stability, each formulation factor must be evaluated for its impact, to balance its risk and benefit in achieving the target drug product shelf life. © 2011 American Association of Pharmaceutical Scientists

The Stability of General Foreign Language Classroom Anxiety across English and French.

ERIC Educational Resources Information Center

Rodriguez, Maximo; Abreu, Orangel

2003-01-01

Examined the stability of the general foreign language classroom anxiety construct across English and French. Subjects were preservice teachers from two western universities in Venezuela majoring in these languages. (Author/VWL)

Using foamed asphalt as a stabilizing agent in full depth reclamation of Route 8 in Belgrade : interim report - third and fourth year, October 2006.

DOT National Transportation Integrated Search

2006-10-01

Maine has a variety of soil types throughout the state. A majority of these soil types degrade rapidly and : have poor stability. To eliminate the cost of supplying quality road base material from a distant source and : increase the stability of exis...

Paternal and maternal factors in preimplantation embryogenesis: interaction with the biochemical environment.

PubMed

Ménézo, Yves J R

2006-05-01

Paternal effect on embryonic development occurs as early as fertilization. Incorrect formation of the spermatozoon due to centrosome defects and abnormal concentrations of any components involved in the activation process lead to failure immediately or in the subsequent cell cycles. Sperm chromosomal abnormalities result in early embryo developmental arrests. Generally poor spermatozoa lead to poor blastocyst formation. Sperm DNA fragmentation may impair even late post-implantation development. The DNA repair capacity of the oocytes is of major importance. Early preimplantation development, i.e. until maternal to zygotic transition, is maternally driven. Maternal mRNAs and proteins are of major importance, as there is an unavoidable turnover of these reserves. Polyadenylation of these mRNAs is precisely controlled, in order to avoid too early or too late transcription and translation of the housekeeping genes. An important set of maternal regulations, such as DNA stability, transcriptional regulation and protection against oxidative stress, are impaired by age. The embryo biochemical endogenous pool is very important and may depend upon the environment, i.e. the culture medium. Paternal, maternal and environmental factors are unavoidable parameters; they become evident when age impairs oocyte quality.

Motion compensation using a suctioning stabilizer for intravital microscopy

PubMed Central

Vinegoni, Claudio; Lee, Sungon; Gorbatov, Rostic; Weissleder, Ralph

2013-01-01

Motion artifacts continue to present a major challenge to single cell imaging in cardiothoracic organs such as the beating heart, blood vessels, or lung. In this study, we present a new water-immersion suctioning stabilizer that enables minimally invasive intravital fluorescence microscopy using water-based stick objectives. The stabilizer works by reducing major motion excursions and can be used in conjunction with both prospective or retrospective gating approaches. We show that the new approach offers cellular resolution in the beating murine heart without perturbing normal physiology. In addition, because this technique allows multiple areas to be easily probed, it offers the opportunity for wide area coverage at high resolution. PMID:24086796

Cis-acting factors modulate stability of intermediate alleles for Huntington disease

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

Goldberg, Y.P.; Zeisler, J.; Thielmann, J.

1994-09-01

The genetic basis of Huntington disease (HD), a late-onset autosomal dominant neurodegenerative disorder, has recently been defined as a CAG trinucleotide expansion in a novel gene on 4p16.3. The CAG length in clinically normal people ranges from 9 to 37, with the vast majority of alleles (99%) containing less than 30 repeats. In contrast, HD patients have CAG lengths greater than 36 with the largest repeat reported to date being 121. Molecular analysis of sporadic cases of HD revealed that new mutations are not rare (3%), and arise from intermediate alleles (IAs). IAs are CAG alleles greater than that usuallymore » seen in the general population (>30), but less than that seen in patients with HD and occur with a frequency of approximately 1.5% of the general population (12/797). An important question is whether these IAs are also susceptible to expansion. In new mutation families, these IAs are unstable in passage through the male germline and in sporadic cases expand to the full mutation associated with the HD phenotype. On the 41 meioses analyzed in new mutation families, 61% were unstable. In contrast to IAs in the new mutation families, the IAs in the general population were predominately stable from one generation to the next. Comparison of the frequency of intergenerational stability between the general population and the new mutation families showed that IAs in the general population are considerably more stable than those in the new mutation families. In contrast to SCA 1 where sequence interruption is thought to play a role in CAG trinucleotide stability, sequence analysis of IAs both from the general population and the new mutation families failed to reveal any interruption of the CAG tracts. These findings suggest that while CAG size is an important factor, other cis-acting factors present in new mutation families but not in the general population are likely to be critical in conferring instability upon the CAG trinucleotide repeat.« less

Freeze-drying of nanosuspensions, part 3: investigation of factors compromising storage stability of highly concentrated drug nanosuspensions.

PubMed

Beirowski, Jakob; Inghelbrecht, Sabine; Arien, Albertina; Gieseler, Henning

2012-01-01

On the basis of a previously developed formulation and process guideline for lyophilized, highly concentrated drug nanosuspensions for parenteral use, it was the purpose of this study to demonstrate that the original nanoparticle size distribution can be preserved over a minimum period of 3 months, even if aggressive primary drying conditions are used. Critical factors were evaluated that were originally believed to affect storage stability of freeze-dried drug nanoparticles. It was found that the nature and concentration of the steric stabilizer, such as Poloxamer 338 and Cremophor EL, are the most important factors for long-term stability of such formulations, independent of the used drug compound. The rational choice of an adequate steric stabilizer, namely Poloxamer 338, in combination with various lyoprotectants seems crucial to prevent physical instabilities of the lyophilized drug nanoparticles during short-term stability experiments at ambient and accelerated conditions. A 200 mg/mL concentration of nanoparticles could successfully be stabilized over the investigated time interval. In the course of the present experiments, polyvinylpyrrolidone, type K15 was found superior to trehalose or sucrose in preserving the original particle size distribution, presumably based on its surface-active properties. Lastly, it was demonstrated that lower water contents are generally beneficial to stabilize such systems. Copyright © 2011 Wiley-Liss, Inc.

Kinematic measures for assessing gait stability in elderly individuals: a systematic review

PubMed Central

Hamacher, D.; Singh, N.B.; Van Dieën, J.H.; Heller, M.O.; Taylor, W.R.

2011-01-01

Falls not only present a considerable health threat, but the resulting treatment and loss of working days also place a heavy economic burden on society. Gait instability is a major fall risk factor, particularly in geriatric patients, and walking is one of the most frequent dynamic activities of daily living. To allow preventive strategies to become effective, it is therefore imperative to identify individuals with an unstable gait. Assessment of dynamic stability and gait variability via biomechanical measures of foot kinematics provides a viable option for quantitative evaluation of gait stability, but the ability of these methods to predict falls has generally not been assessed. Although various methods for assessing gait stability exist, their sensitivity and applicability in a clinical setting, as well as their cost-effectiveness, need verification. The objective of this systematic review was therefore to evaluate the sensitivity of biomechanical measures that quantify gait stability among elderly individuals and to evaluate the cost of measurement instrumentation required for application in a clinical setting. To assess gait stability, a comparative effect size (Cohen's d) analysis of variability and dynamic stability of foot trajectories during level walking was performed on 29 of an initial yield of 9889 articles from four electronic databases. The results of this survey demonstrate that linear variability of temporal measures of swing and stance was most capable of distinguishing between fallers and non-fallers, whereas step width and stride velocity prove more capable of discriminating between old versus young (OY) adults. In addition, while orbital stability measures (Floquet multipliers) applied to gait have been shown to distinguish between both elderly fallers and non-fallers as well as between young and old adults, local stability measures (λs) have been able to distinguish between young and old adults. Both linear and nonlinear measures of foot time series during gait seem to hold predictive ability in distinguishing healthy from fall-prone elderly adults. In conclusion, biomechanical measurements offer promise for identifying individuals at risk of falling and can be obtained with relatively low-cost tools. Incorporation of the most promising measures in combined retrospective and prospective studies for understanding fall risk and designing preventive strategies is warranted. PMID:21880615

Kinematic measures for assessing gait stability in elderly individuals: a systematic review.

PubMed

Hamacher, D; Singh, N B; Van Dieën, J H; Heller, M O; Taylor, W R

2011-12-07

Falls not only present a considerable health threat, but the resulting treatment and loss of working days also place a heavy economic burden on society. Gait instability is a major fall risk factor, particularly in geriatric patients, and walking is one of the most frequent dynamic activities of daily living. To allow preventive strategies to become effective, it is therefore imperative to identify individuals with an unstable gait. Assessment of dynamic stability and gait variability via biomechanical measures of foot kinematics provides a viable option for quantitative evaluation of gait stability, but the ability of these methods to predict falls has generally not been assessed. Although various methods for assessing gait stability exist, their sensitivity and applicability in a clinical setting, as well as their cost-effectiveness, need verification. The objective of this systematic review was therefore to evaluate the sensitivity of biomechanical measures that quantify gait stability among elderly individuals and to evaluate the cost of measurement instrumentation required for application in a clinical setting. To assess gait stability, a comparative effect size (Cohen's d) analysis of variability and dynamic stability of foot trajectories during level walking was performed on 29 of an initial yield of 9889 articles from four electronic databases. The results of this survey demonstrate that linear variability of temporal measures of swing and stance was most capable of distinguishing between fallers and non-fallers, whereas step width and stride velocity prove more capable of discriminating between old versus young (OY) adults. In addition, while orbital stability measures (Floquet multipliers) applied to gait have been shown to distinguish between both elderly fallers and non-fallers as well as between young and old adults, local stability measures (λs) have been able to distinguish between young and old adults. Both linear and nonlinear measures of foot time series during gait seem to hold predictive ability in distinguishing healthy from fall-prone elderly adults. In conclusion, biomechanical measurements offer promise for identifying individuals at risk of falling and can be obtained with relatively low-cost tools. Incorporation of the most promising measures in combined retrospective and prospective studies for understanding fall risk and designing preventive strategies is warranted.

Incompressible boundary-layer stability analysis of LFC experimental data for sub-critical Mach numbers. M.S. Thesis

NASA Technical Reports Server (NTRS)

Berry, S. A.

1986-01-01

An incompressible boundary-layer stability analysis of Laminar Flow Control (LFC) experimental data was completed and the results are presented. This analysis was undertaken for three reasons: to study laminar boundary-layer stability on a modern swept LFC airfoil; to calculate incompressible design limits of linear stability theory as applied to a modern airfoil at high subsonic speeds; and to verify the use of linear stability theory as a design tool. The experimental data were taken from the slotted LFC experiment recently completed in the NASA Langley 8-Foot Transonic Pressure Tunnel. Linear stability theory was applied and the results were compared with transition data to arrive at correlated n-factors. Results of the analysis showed that for the configuration and cases studied, Tollmien-Schlichting (TS) amplification was the dominating disturbance influencing transition. For these cases, incompressible linear stability theory correlated with an n-factor for TS waves of approximately 10 at transition. The n-factor method correlated rather consistently to this value despite a number of non-ideal conditions which indicates the method is useful as a design tool for advanced laminar flow airfoils.

Muscle recruitment patterns of the subscapularis, serratus anterior and other shoulder girdle muscles during isokinetic internal and external rotations.

PubMed

Gaudet, Sylvain; Tremblay, Jonathan; Begon, Mickael

2018-05-01

The aims of this study were to investigate the differences in peak muscle activity and recruitment patterns during high- and low-velocity, concentric and eccentric, internal and external isokinetic shoulder rotations. Electromyographic activity of the rotator cuff and eight superficial muscles of the shoulder girdle was recorded on 25 healthy adults during isokinetic internal and external shoulder rotation at 60°/s and 240°/s. Peak muscle activity, electromyographic envelopes and peak isokinetic moments were analyzed using three-factor ANOVA and statistical parametric mapping. The subscapularis and serratus anterior showed moderate to high peak activity levels during each conditions, while the middle and posterior deltoids, upper, middle and lower trapezius, infraspinatus and supraspinatus showed higher peak activity levels during external rotations (+36.5% of maximum voluntary activation (MVA)). The pectoralis major and latissimus dorsi were more active during internal rotations (+40% of MVA). Only middle trapezius and pectoralis major electromyographic activity decreased with increasing velocity. Peak muscle activity was similar or lower during eccentric contractions, although the peak isokinetic moment increased by 35% on average. The subscapularis and serratus anterior appear to be important stabilizers of the glenohumeral joint and scapula. Isokinetic eccentric training at high velocities may allow for faster recruitment of the shoulder girdle muscles, which could improve joint stability during shoulder internal and external rotations.

[Impact of anchorage implant design factors on its primary stability].

PubMed

Zhang, J N; Lu, H P; Zhong, C

2017-08-09

During the past decade, the anchorage implants have been widely used in the orthodontic treatment. Many scholars have studied the influence of different factors on anchorage implant's primary stability, including anchorage implant's material properties, structural design, surgical procedure, bone condition, loading force's magnitude and direction. This article is to review the influence of anchorage implant's shape, dimension, neck design and thread design on its primary stability.

Mathematical Modeling Applied to Prediction of Landslides in Southern Brazil

NASA Astrophysics Data System (ADS)

Silva, Lúcia; Araújo, João; Braga, Beatriz; Fernandes, Nelson

2013-04-01

Mass movements are natural phenomena that occur on the slopes and are important agents working in landscape development. These movements have caused serious damage to infrastructure and properties. In addition to the mass movements occurring in natural slopes, there is also a large number of accidents induced by human action in the landscape. The change of use and land cover for the introduction of agriculture is a good example that have affected the stability of slopes. Land use and/or land cover changes have direct and indirect effects on slope stability and frequently represent a major factor controlling the occurrence of man-induced mass movements. In Brazil, especially in the southern and southeastern regions, areas of original natural rain forest have been continuously replaced by agriculture during the last decades, leading to important modifications in soil mechanical properties and to major changes in hillslope hydrology. In these regions, such effects are amplified due to the steep hilly topography, intense summer rainfall events and dense urbanization. In November 2008, a major landslide event took place in a rural area with intensive agriculture in the state of Santa Catarina (Morro do Baú) where many catastrophic landslides were triggered after a long rainy period. In this area, the natural forest has been replaced by huge banana and pine plantations. The state of Santa Catarina in recent decades has been the scene of several incidents of mass movements such as this catastrophic event. In this study, based on field mapping and modeling, we characterize the role played by geomorphological and geological factors in controlling the spatial distribution of landslides in the Morro do Baú area. In order to attain such objective, a digital elevation model of the basin was generated with a 10m grid in which the topographic parameters were obtained. The spatial distribution of the scars from this major event was mapped from another image, obtained immediately after the landslide event. Numerical simulations with the SHALSTAB model were carried out in the basin and the results compared to the original location of the scars in the field. The results suggest that the combination of field mapping with the numerical simulation scenarios may contribute to the definition of better land management practices in such environment. Besides this, the replacement of the natural rain forest by huge banana plantations in this environment may have played a major role in defining the spatial distribution of landslides scars and the magnitude of the landslides generated.

Gene expression studies of reference genes for quantitative real-time PCR: an overview in insects.

PubMed

Shakeel, Muhammad; Rodriguez, Alicia; Tahir, Urfa Bin; Jin, Fengliang

2018-02-01

Whenever gene expression is being examined, it is essential that a normalization process is carried out to eliminate non-biological variations. The use of reference genes, such as glyceraldehyde-3-phosphate dehydrogenase, actin, and ribosomal protein genes, is the usual method of choice for normalizing gene expression. Although reference genes are used to normalize target gene expression, a major problem is that the stability of these genes differs among tissues, developmental stages, species, and responses to abiotic factors. Therefore, the use and validation of multiple reference genes are required. This review discusses the reasons that why RT-qPCR has become the preferred method for validating results of gene expression profiles, the use of specific and non-specific dyes and the importance of use of primers and probes for qPCR as well as to discuss several statistical algorithms developed to help the validation of potential reference genes. The conflicts arising in the use of classical reference genes in gene normalization and their replacement with novel references are also discussed by citing the high stability and low stability of classical and novel reference genes under various biotic and abiotic experimental conditions by employing various methods applied for the reference genes amplification.

Laboratory and 3-D distinct element analysis of the failure mechanism of a slope under external surcharge

NASA Astrophysics Data System (ADS)

Li, N.; Cheng, Y. M.

2015-01-01

Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient detail. There is however increasing interest in the consequences after the initiation of failure that includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more detail and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and a laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanisms and the post-failure mechanisms of slopes will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure, which can give additional information not available from the classical methods of analysis.

Laboratory and 3-D-distinct element analysis of failure mechanism of slope under external surcharge

NASA Astrophysics Data System (ADS)

Li, N.; Cheng, Y. M.

2014-09-01

Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient details. There are however increasing interest on the consequences after the initiation of failure which includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more details and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanism and the post-failure mechanism of slope will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure which can give additional information not available from the classical methods of analysis.

Moderation of Harsh Parenting on Genetic and Environmental Contributions to Child and Adolescent Deviant Peer Affiliation: A Longitudinal Twin Study.

PubMed

Li, Mengjiao; Chen, Jie; Li, Xinying; Deater-Deckard, Kirby

2015-07-01

Affiliation with deviant peers is associated with biologically influenced personal attributes, and is itself a major contributor to growth in antisocial behavior over childhood and adolescence. Several studies have shown that variance in child and adolescent deviant peer affiliation includes genetic and non-genetic influences, but none have examined longitudinal genetic and environmental stability or change within the context of harsh parenting. To address this gap, we tested the moderating role of harsh parenting on genetic and environmental stability or change of deviant peer affiliation in a longitudinal (spanning one and a half years) study of Chinese child and adolescent twin pairs (N = 993, 52.0% female). Using multiple informants (child- and parent-reports) and measurement methods to minimize rater bias, we found that individual differences in deviant peer affiliation at each assessment were similarly explained by moderate genetic and nonshared environmental variance. The longitudinal stability and change of deviant peer affiliation were explained by genetic and nonshared environmental factors. The results also revealed that the genetic variance for deviant peer affiliation is higher in the families with harsher parenting. This amplified genetic risk underscores the role of harsh parenting in the selection and socialization process of deviant peer relationships.

Functional Stability of Plasminogen Activator Inhibitor-1

PubMed Central

Kuru, Pinar; Toksoy Oner, Ebru; Agirbasli, Mehmet

2014-01-01

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT) and myocardial infarction (MI). The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease. PMID:25386620

Suicidal and nonsuicidal adolescents: different factors contribute to self-esteem.

PubMed

Grøholt, Berit; Ekeberg, Oivind; Wichstrøm, Lars; Haldorsen, Tor

2005-10-01

Some risk and protective factors differ in their importance to suicidal and nonsuicidal people. In this research we explore the cross-sectional differences between risk factors among suicidal adolescents and nonsuicidal adolescents by focusing on self-esteem. Sixty-five suicidal and 390 nonsuicidal adolescents were compared on Harter's Self-Perceived Profile for Adolescents, self-concept stability, seeking support, loneliness, and depression. Self-concept stability, loneliness, and peer support correlated differently with self-esteem. In multivariate regression analyses, variance in self-esteem was explained by depression and loneliness, and among nonsuicidal adolescents also by self-concept stability, support, and competencies. Loneliness and self-concept stability related differently to self-esteem in suicidal and nonsuicidal adolescents. When the aim is to enhance self-esteem, this difference may delineate suicidal subgroups that need special interventions.

Salt Marsh development studies at Waquoit Bay, Massachusetts: Influence of geomorphology on long-term plant community structure

NASA Astrophysics Data System (ADS)

Orson, Richard A.; Howes, Brian L.

1992-11-01

Stochastic events relating to beach formation and inlet dynamics have been the major factors influencing the development of the Waquoit Bay tidal marshes. This results from the physical structure of the Waquoit Bay system where tidal exchange is limited to one or two small inlets and is in contrast to marsh development in nearby Barnstable Marsh where direct unrestricted exchange with Cape Cod Bay has smoothed the effects of stochastic events on vegetation development. We contend that vegetation development in salt marshes where connections to adjacent waters are restricted will be dominated by abiotic factors (e.g. storms, sedimentation rates, etc.) while those marshes directly linked to open bodies of water and where alterations to hydrodynamic factors are gradual, autecological processes (e.g. interspecific competition) will dominate long-term plant community development. The results from the five marsh systems within the Waquoit Bay complex suggest that once a vegetation change occurs the new community tended to persist for long periods of time (100's-1000's years). Stability of the 'new' community appeared to depend upon the stability of the physical structure of the system and/or time between perturbations necessary to allow the slower autecological processes to have a discernable effect. In order for the plant community to persist as long as observed, the vegetation must also be exerting an influence on the processes of development. Increased production of roots and rhizomes and growth characteristics (density of culms) are some of the factors which help to maintain long-term species dominance. It is clear from this investigation that the structure of the plant community at any one point in time is dependent upon numerous factors including historical developmental influences. To properly assess changes to the present plant community or determine recent rates of accretion, historic developmental trends must be considered. The factors that have influenced the development of marsh in the past will be important in understanding and formulating predictive models in the future.

An approach to value-based simulator selection: The creation and evaluation of the simulator value index tool.

PubMed

Rooney, Deborah M; Hananel, David M; Covington, Benjamin J; Dionise, Patrick L; Nykamp, Michael T; Pederson, Melvin; Sahloul, Jamal M; Vasquez, Rachael; Seagull, F Jacob; Pinsky, Harold M; Sweier, Domenica G; Cooke, James M

2018-04-01

Currently there is no reliable, standardized mechanism to support health care professionals during the evaluation of and procurement processes for simulators. A tool founded on best practices could facilitate simulator purchase processes. In a 3-phase process, we identified top factors considered during the simulator purchase process through expert consensus (n = 127), created the Simulator Value Index (SVI) tool, evaluated targeted validity evidence, and evaluated the practical value of this SVI. A web-based survey was sent to simulation professionals. Participants (n = 79) used the SVI and provided feedback. We evaluated the practical value of 4 tool variations by calculating their sensitivity to predict a preferred simulator. Seventeen top factors were identified and ranked. The top 2 were technical stability/reliability of the simulator and customer service, with no practical differences in rank across institution or stakeholder role. Full SVI variations predicted successfully the preferred simulator with good (87%) sensitivity, whereas the sensitivity of variations in cost and customer service and cost and technical stability decreased (≤54%). The majority (73%) of participants agreed that the SVI was helpful at guiding simulator purchase decisions, and 88% agreed the SVI tool would help facilitate discussion with peers and leadership. Our findings indicate the SVI supports the process of simulator purchase using a standardized framework. Sensitivity of the tool improved when factors extend beyond traditionally targeted factors. We propose the tool will facilitate discussion amongst simulation professionals dealing with simulation, provide essential information for finance and procurement professionals, and improve the long-term value of simulation solutions. Limitations and application of the tool are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Rock Slope Stability Evaluation in a Steep-Walled Canyon: Application to Elevator Construction in the Yunlong River Valley, Enshi, China

NASA Astrophysics Data System (ADS)

Xiao, Lili; Chai, Bo; Yin, Kunlong

2015-09-01

A passenger elevator is to be built on a nearly vertical slope in the National Geological Park in Enshi, Hubei province, China. Three steps comprise the construction: excavating the slope toe for the elevator platform, building the elevator on the platform, and affixing the elevator to the slope using anchors. To evaluate the rock slope stability in the elevator area and the safety of the elevator construction, we applied three techniques: qualitative analysis, formula calculation, and numerical simulation methods, based on field investigation and parameter selection, and considering both wet and dry conditions, pre- and post-construction. Qualitative stability factors for sliding and falling were calculated using the limit equilibrium method; the results show that the slope as a whole is stable, with a few unstable blocks, notably block BT1. Formula-based stability factors were calculated for four sections on block BT1, revealing the following: anchors will decrease the stability of certain rock pieces; the lowest average stability factor after anchoring will be K f = 1.36 in wet conditions; block BT1 should be reinforced during elevator construction, up to a first-class slope stability factor of K f = 1.40; and the slope as a whole is stable. Numerical simulation using FLAC3D indicated that the stress distribution will reach equilibrium for all steps before and after construction, and that the factor of safety (FOS) is within the general slope safety range (FOS > 1.05). We suggest that unstable pieces in block BT1 be reinforced during construction to a first-class slope safety range (FOS > 1.3), and that deformation monitoring on the slope surface be implemented.

The Fatal Five? Five Factors That Enhance Effectiveness of Stability Operations

DTIC Science & Technology

2014-05-22

Conflict METL Mission Essential Task List MSG Military Support Group NSS National Security Strategy OOTW Operations Other Than War PDF...Revolutionary War. However, despite the propensity for the military to conduct this type of operation, the U.S. Army has a mixed record of executing stability...the U.S. Army has a mixed record of executing stability tasks. This monograph identifies five factors that contribute to the effectiveness of

TIA-1 and TIAR interact with 5'-UTR of enterovirus 71 genome and facilitate viral replication.

PubMed

Wang, Xiaohui; Wang, Huanru; Li, Yixuan; Jin, Yu; Chu, Ying; Su, Airong; Wu, Zhiwei

2015-10-16

Enterovirus 71 is one of the major causative pathogens of HFMD in children. Upon infection, the viral RNA is translated in an IRES-dependent manner and requires several host factors for effective replication. Here, we found that T-cell-restricted intracellular antigen 1 (TIA-1), and TIA-1 related protein (TIAR) were translocated from nucleus to cytoplasm after EV71 infection and localized to the sites of viral replication. We found that TIA-1 and TIAR can facilitate EV71 replication by enhancing the viral genome synthesis in host cells. We demonstrated that both proteins bound to the stem-loop I of 5'-UTR of viral genome and improved the stability of viral genomic RNA. Our results suggest that TIA-1 and TIAR are two new host factors that interact with 5-UTR of EV71 genome and positively regulate viral replication. Copyright © 2015 Elsevier Inc. All rights reserved.

Mathematical model for the Bridgman-Stockbarger crystal growing system

NASA Technical Reports Server (NTRS)

Roberts, G. O.

1986-01-01

In a major technical breakthrough, a computer model for Bridgman-Stockbarger crystal growth was developed. The model includes melt convection, solute effects, thermal conduction in the ampule, melt, and crystal, and the determination of the curved moving crystal-melt interface. The key to the numerical method is the use of a nonuniform computational mesh which moves with the interface, so that the interface is a mesh surface. In addition, implicit methods are used for advection and diffusion of heat, concentration, and vorticity, for interface movement, and for internal gracity waves. This allows large time-steps without loss of stability or accuracy. Numerical results are presented for the interface shape, temperature distribution, and concentration distribution, in steady-state crystl growth. Solutions are presented for two test cases using water, with two different salts in solution. The two diffusivities differ by a factor of ten, and the concentrations differ by a factor of twenty.

Psychometric Properties of the International Personality Item Pool Big-Five Personality Questionnaire for the Greek population.

PubMed

Ypofanti, Maria; Zisi, Vasiliki; Zourbanos, Nikolaos; Mouchtouri, Barbara; Tzanne, Pothiti; Theodorakis, Yannis; Lyrakos, Georgios

2015-09-30

Goldberg's International Personality Item Pool (IPIP) big-five personality factor markers currently lack validating evidence. The structure of the 50-item IPIP was examined in two different adult samples (total N=811), in each case justifying a 5-factor solution, with only minor discrepancies. Age differences were comparable to previous findings using other inventories. One sample (N=193) also completed additionally another personality measure (the TIPI Short Form). Conscientiousness, extraversion and emotional stability/neuroticism scales of the IPIP were highly correlated with those of the TIPI (r=0.62 to 0.65, P=0.01). Agreeableness and Intellect/Openness scales correlated less strongly (r=0.54 and 0.58 respectively, P=0.01). The IPIP scales have good internal consistency (a=0.88) and relate strongly to major dimensions of personality assessed by the two questionnaires.

Isolation and characterization of a new clotting factor from Bothrops jararacussu (jararacuçu) venom.

PubMed

Andrião-Escarso, S H; Sampaio, S V; Cunha, O A; Marangoni, S; Oliveira, B; Giglio, J R

1997-07-01

A detailed procedure for the isolation of a new clotting enzyme from the venom of Bothrops jararacussu (common name jararacuçu) is described. The estimated mol. wt of the native protein was 30,100 but 37,500 after reduction by dithiothreitol. Two major close bands corresponding to pI 5.18 and 5.20 were detected by electrofocusing but, after methanolysis, a single band focused at pI 8.20. The mol. wt of the protein moiety of this glycoprotein was 28,500, showing V-V-G-A-D-N-C-N-F-N... as N-terminal sequence. The content of neutral sugar was 4.8% and that of total sugars 5.3%. This clotting factor degraded only the A alpha-chain of the fibrinogen molecule. The stability of the clot, when produced in the presence of aprotinin opens new uses for snake clotting enzymes in the production of fibrin glue.

The Structure and Temporal Stability of the Child and Adolescent Perfectionism Scale

ERIC Educational Resources Information Center

O'Connor, Rory C.; Dixon, Diane; Rasmussen, Susan

2009-01-01

In this study, the authors examined the factor structure and temporal stability of the Child and Adolescent Perfectionism Scale (CAPS; G. L. Flett, P. L. Hewitt, D. J. Boucher, L. A. Davidson, & Y. Munro, 1997) in 2 samples of adolescents (15-16 years old). In Sample 1 (n = 624), confirmatory factor analysis did not support a 2-factor structure…

Applying Factor Analysis Combined with Kriging and Information Entropy Theory for Mapping and Evaluating the Stability of Groundwater Quality Variation in Taiwan

PubMed Central

Shyu, Guey-Shin; Cheng, Bai-You; Chiang, Chi-Ting; Yao, Pei-Hsuan; Chang, Tsun-Kuo

2011-01-01

In Taiwan many factors, whether geological parent materials, human activities, and climate change, can affect the groundwater quality and its stability. This work combines factor analysis and kriging with information entropy theory to interpret the stability of groundwater quality variation in Taiwan between 2005 and 2007. Groundwater quality demonstrated apparent differences between the northern and southern areas of Taiwan when divided by the Wu River. Approximately 52% of the monitoring wells in southern Taiwan suffered from progressing seawater intrusion, causing unstable groundwater quality. Industrial and livestock wastewaters also polluted 59.6% of the monitoring wells, resulting in elevated EC and TOC concentrations in the groundwater. In northern Taiwan, domestic wastewaters polluted city groundwater, resulting in higher NH3-N concentration and groundwater quality instability was apparent among 10.3% of the monitoring wells. The method proposed in this study for analyzing groundwater quality inspects common stability factors, identifies potential areas influenced by common factors, and assists in elevating and reinforcing information in support of an overall groundwater management strategy. PMID:21695030

Caring for the patients with cervical spine injuries: what have we learned?

PubMed

Ghafoor, Abid U; Martin, Timothy W; Gopalakrishnan, Senthil; Viswamitra, Sanjaya

2005-12-01

Anesthesiologists are often involved in the early management and resuscitation of patients who have sustained cervical spine injuries (CSIs). The most crucial step in managing a patient with suspected CSI is the prevention of further insult to the cervical spine (C-spine). In this review, important factors related to initial management, diagnosis, airway and anesthetic management of patients with CSI are presented. Medline search was performed to seek out the English-language literature using the following phrases and keywords: spine trauma; cervical spine; airway management after CSI. Cervical spine injury occurs in up to 3% to 6% of all patients with trauma. The initial management of a patient with potential spine injury requires a high degree of suspicion for CSI so that early stabilization of the spine can be used to prevent further neurological damage. Diagnostic radiology has a critical role to play; however, clinical evaluation is equally important in excluding CSI in a conscious and cooperative patient. Although in-line stabilization reduces the movement at C-spine, traction causes clinically significant distraction and should be avoided. A high level of suspicion and anticipation are the major components of decision making and management in a patient with CSI. Endotracheal intubation using the Bullard laryngoscope may have some advantages over other techniques as it causes less head and C-spine extension than the conventional laryngoscope, and this results in a better view. However, the current opinion is that oral intubation using a Macintosh blade after intravenous induction of anesthesia and muscle relaxation along with inline stabilization is the safest and quickest way to achieve intubation in a patient with suspected CSI. In summation caution, close care and maintenance of spinal immobilization are more important factors in limiting the risk of secondary neurological injury than any particular technique.

Age-Related Variability in Tongue Pressure Patterns for Maximum Isometric and Saliva Swallowing Tasks

PubMed Central

Peladeau-Pigeon, Melanie

2017-01-01

Purpose The ability to generate tongue pressure plays a major role in bolus transport in swallowing. In studies of motor control, stability or variability of movement is a feature that changes with age, disease, task complexity, and perturbation. In this study, we explored whether age and tongue strength influence the stability of the tongue pressure generation pattern during isometric and swallowing tasks in healthy volunteers. Method Tongue pressure data, collected using the Iowa Oral Performance Instrument, were analyzed from 84 participants in sex-balanced and decade age-group strata. Tasks included maximum anterior and posterior isometric pressures and regular-effort saliva swallows. The cyclic spatiotemporal index (cSTI) was used to capture stability (vs. variability) in patterns of pressure generation. Mixed-model repeated measures analyses of covariance were performed separately for each task (anterior and posterior isometric pressures, saliva swallows) with between-participant factors of age group and sex, a within-participant factor of task repetition, and a continuous covariate of tongue strength. Results Neither age group nor sex effects were found. There was no significant relationship between tongue strength and the cSTI on the anterior isometric tongue pressure task (r = −.11). For the posterior isometric tongue pressure task, a significant negative correlation (r = −.395) was found between tongue strength and the cSTI. The opposite pattern of a significant positive correlation (r = .29) between tongue strength and the cSTI was seen for the saliva swallow task. Conclusions Tongue pressure generation patterns appear highly stable across repeated maximum isometric and saliva swallow tasks, despite advancing age. Greater pattern variability is seen with weaker posterior isometric pressures. Overall, saliva swallows had the lowest pressure amplitudes and highest pressure pattern variability as measured by the cSTI. PMID:29114767

Physics basis for an advanced physics and advanced technology tokamak power plant configuration: ARIES-ACT1

DOE PAGES

Kessel, C. E.; Poli, F. M.; Ghantous, K.; ...

2015-01-01

Here, the advanced physics and advanced technology tokamak power plant ARIES-ACT1 has a major radius of 6.25 m at an aspect ratio of 4.0, toroidal field of 6.0 T, strong shaping with elongation of 2.2, and triangularity of 0.63. The broadest pressure cases reached wall-stabilized β N ~ 5.75, limited by n = 3 external kink mode requiring a conducting shell at b/a = 0.3, requiring plasma rotation, feedback, and/or kinetic stabilization. The medium pressure peaking case reaches β N = 5.28 with B T = 6.75, while the peaked pressure case reaches β N < 5.15. Fast particle magnetohydrodynamicmore » stability shows that the alpha particles are unstable, but this leads to redistribution to larger minor radius rather than loss from the plasma. Edge and divertor plasma modeling shows that 75% of the power to the divertor can be radiated with an ITER-like divertor geometry, while >95% can be radiated in a stable detached mode with an orthogonal target and wide slot geometry. The bootstrap current fraction is 91% with a q95 of 4.5, requiring ~1.1 MA of external current drive. This current is supplied with 5 MW of ion cyclotron radio frequency/fast wave and 40 MW of lower hybrid current drive. Electron cyclotron is most effective for safety factor control over ρ~0.2 to 0.6 with 20 MW. The pedestal density is ~0.9×10 20/m 3, and the temperature is ~4.4 keV. The H98 factor is 1.65, n/n Gr = 1.0, and the ratio of net power to threshold power is 2.8 to 3.0 in the flattop.« less

Assessing the dynamics of the upper soil layer relative to soil management practices

NASA Astrophysics Data System (ADS)

Hatfield, J.; Wacha, K.; Dold, C.

2017-12-01

The upper layer of the soil is the critical interface between the soil and the atmosphere and is the most dynamic in response to management practices. One of the soil properties most reflective to changes in management is the stability of the aggregates because this property controls infiltration of water and exchange of gases. An aggregation model has been developed based on the factors that control how aggregates form and the forces which degrade aggregates. One of the major factors for this model is the storage of carbon into the soil and the interaction with the soil biological component. To increase soil biology requires a stable microclimate that provides food, water, shelter, and oxygen which in turn facilitates the incorporation of organic material into forms that can be combined with soil particles to create stable aggregates. The processes that increase aggregate size and stability are directly linked the continual functioning of the biological component which in turn changes the physical and chemical properties of the soil. Soil aggregates begin to degrade as soon as there is no longer a supply of organic material into the soil. These processes can range from removal of organic material and excessive tillage. To increase aggregation of the upper soil layer requires a continual supply of organic material and the biological activity that incorporates organic material into substances that create a stable aggregate. Soils that exhibit stable soil aggregates at the surface have a prolonged infiltration rate with less runoff and a gas exchange that ensures adequate oxygen for maximum biological activity. Quantifying the dynamics of the soil surface layer provides a quantitative understanding of how management practices affect aggregate stability.

[The functional state classification and evaluation of the stability level in mental loads based on the factor structure of heart rate variability parameters].

PubMed

Mashin, V A; Mashina, M N

2004-12-01

In the paper, outcomes of the researches devoted to factor analysis of heart rate variability parameters and definition of the most informative parameters for diagnostics of functional states and an evaluation of level of stability to mental loads, are presented. The factor structure of parameters, which unclude integral level of heart rate variability (1), balance between activity of vagus and brain cortical-limbic systems (2), integrated level of cardiovascular system functioning (3), is substantiated. Factor analysis outcomes have been used for construction of functional state classification, for their differential diagnostics, and for development and check of algorithm for evaluation of the stability level in mental loads.

Factors Affecting Lateral Stability and Controllability

NASA Technical Reports Server (NTRS)

Campbell, John P; Toll, Thomas A

1948-01-01

The effects on dynamic lateral stability and controllability of some of the important aerodynamic and mass characteristics are discussed and methods are presented for estimating the various stability parameters to be used in the calculation of the dynamic lateral stability of airplanes with swept and low-aspect-ratio wings.

Relationship between rotor-bearing system stability and supporting bearings

NASA Astrophysics Data System (ADS)

Xu, Longxiang; Zhu, Jun

1993-04-01

Results of an investigation of the relationship between the rotor-bearing system stability of a large rotating machinery and the supporting bearings are presented. The contribution factor of the bearings to the system stability is established. The bearing with the largest contribution factor yields the greatest contribution to the system stability. Rotor-bearing system stability depends mainly on the dynamic characteristic performance of the sensitive bearings. Appropriate readjustment in the type or design parameters of these bearings will result in a significant improvement in the stability margin. Numerical examples are carried out for a model rotor-bearing system with five bearings in a domestic 200-MW turbine generator set; they show that the calculated results are in good agreement with those measured for some actual rotating machinery. A scheme to reconstruct the domestic 200-MW turbine generator set is discussed.

Engineering Proteins for Thermostability with iRDP Web Server

PubMed Central

Ghanate, Avinash; Ramasamy, Sureshkumar; Suresh, C. G.

2015-01-01

Engineering protein molecules with desired structure and biological functions has been an elusive goal. Development of industrially viable proteins with improved properties such as stability, catalytic activity and altered specificity by modifying the structure of an existing protein has widely been targeted through rational protein engineering. Although a range of factors contributing to thermal stability have been identified and widely researched, the in silico implementation of these as strategies directed towards enhancement of protein stability has not yet been explored extensively. A wide range of structural analysis tools is currently available for in silico protein engineering. However these tools concentrate on only a limited number of factors or individual protein structures, resulting in cumbersome and time-consuming analysis. The iRDP web server presented here provides a unified platform comprising of iCAPS, iStability and iMutants modules. Each module addresses different facets of effective rational engineering of proteins aiming towards enhanced stability. While iCAPS aids in selection of target protein based on factors contributing to structural stability, iStability uniquely offers in silico implementation of known thermostabilization strategies in proteins for identification and stability prediction of potential stabilizing mutation sites. iMutants aims to assess mutants based on changes in local interaction network and degree of residue conservation at the mutation sites. Each module was validated using an extensively diverse dataset. The server is freely accessible at http://irdp.ncl.res.in and has no login requirements. PMID:26436543

Engineering Proteins for Thermostability with iRDP Web Server.

PubMed

Panigrahi, Priyabrata; Sule, Manas; Ghanate, Avinash; Ramasamy, Sureshkumar; Suresh, C G

2015-01-01

Engineering protein molecules with desired structure and biological functions has been an elusive goal. Development of industrially viable proteins with improved properties such as stability, catalytic activity and altered specificity by modifying the structure of an existing protein has widely been targeted through rational protein engineering. Although a range of factors contributing to thermal stability have been identified and widely researched, the in silico implementation of these as strategies directed towards enhancement of protein stability has not yet been explored extensively. A wide range of structural analysis tools is currently available for in silico protein engineering. However these tools concentrate on only a limited number of factors or individual protein structures, resulting in cumbersome and time-consuming analysis. The iRDP web server presented here provides a unified platform comprising of iCAPS, iStability and iMutants modules. Each module addresses different facets of effective rational engineering of proteins aiming towards enhanced stability. While iCAPS aids in selection of target protein based on factors contributing to structural stability, iStability uniquely offers in silico implementation of known thermostabilization strategies in proteins for identification and stability prediction of potential stabilizing mutation sites. iMutants aims to assess mutants based on changes in local interaction network and degree of residue conservation at the mutation sites. Each module was validated using an extensively diverse dataset. The server is freely accessible at http://irdp.ncl.res.in and has no login requirements.

Stability analysis and compensation of a boost regulator with two-loop control

NASA Technical Reports Server (NTRS)

Wester, G. W.

1974-01-01

A useful stability measure has been demonstrated by Wester (1973) for switching regulators with a single feedback loop by applying the Nyquist criterion to the approximate loop gain determined by a time-averaging technique. This approach is extended and applied to the characterization, stability analysis, and compensation design of a switching regulator with two-loop control. The role and relative significance of each control loop is clarified on the basis of a description of circuit operation, and the major and minor loops are identified. In view of the inapplicability of linear feedback theory, describing functions of the feedback loops and power stage are derived, using small-signal analysis. Several phenomena revealed from an analysis of the major loop gain are discussed.

Dynamical Studies of N-Body Gravity and Tidal Dissipation in the TRAPPIST-1 Star System

NASA Astrophysics Data System (ADS)

Nayak, Michael; Kuettel, Donald H.; Stebler, Shane T.; Udrea, Bogdan

2018-01-01

To date, we have discovered a total of 2,729 planetary systems that contain more than 3,639 known exoplanets [1]. A majority of these are defined as compact systems, containing multiple exoplanets within 0.25 AU of the central star. It has been shown that tightly packed exoplanets avoid colliding due to long-term resonance-induced orbit stability [2]. However, due to extreme proximity, these planets experience intense gravitational forces from each other that are unprecedented within our own solar system, which makes the existence of exomoons doubtful. We present the results of an initial study evaluating dynamical stability of potential exomoons within such highly compact systems.This work is baselined around TRAPPIST-1, an ultra-cool dwarf star that hosts seven temperate terrestrial planets, three of which are in the habitable zone, orbiting within 0.06 AU [3]. N-body simulations place a grid of test particles varying semi-major axis, eccentricity, and inclination around the three habitable zone planets. We find that most exomoons with semi-major axes less than half the Hill sphere of their respective planet are stable over 10 kyrs, with several stable over 300 kyrs.However, in compact systems, tidal influences from other planets can compete with tidal effects from the primary planet, resulting in possible instabilities and massive amounts of tidal dissipation. We investigate these effects with a large grid search that incorporates exomoon radius, tidal quality factor and a range of planet rigidities. Results of simulations that combine n-body gravity effects with both planetary and satellite tides are presented and contrasted with n-body results. Finally, we examine long-term stability (> 1Myrs) of the stable subset of test particles from the n-body simulation with the addition of tidal dissipation, to determine if exomoons can survive around planets e, f, and g in the TRAPPIST-1 system.[1] Schneider (2017). The Extrasolar Planets Encyclopedia. http://exoplanet.eu/catalog/.[2] Tamayo et al (2017). Convergent Migration Renders TRAPPIST-1 Long-lived. ApJL, 840(2), L19.[3] Gillon et al (2016). Temperate Earth-sized planets transiting a nearby ultracool dwarf star. Nature, 533 (7602), 221-224.

Differential stability of therapeutic peptides with different proteolytic cleavage sites in blood, plasma and serum.

PubMed

Böttger, Roland; Hoffmann, Ralf; Knappe, Daniel

2017-01-01

Proteolytic degradation of peptide-based drugs is often considered as major weakness limiting systemic therapeutic applications. Therefore, huge efforts are typically devoted to stabilize sequences against proteases present in serum or plasma, obtained as supernatants after complete blood coagulation or centrifugation of blood supplemented with anticoagulants, respectively. Plasma and serum are reproducibly obtained from animals and humans allowing consistent for clinical analyses and research applications. However, the spectrum of active or activated proteases appears to vary depending on the activation of proteases and cofactors during coagulation (serum) or inhibition of such enzymes by anticoagulants (plasma), such as EDTA (metallo- and Ca2+-dependent proteases) and heparin (e.g. thrombin, factor Xa). Here, we studied the presumed effects on peptide degradation by taking blood via cardiac puncture of CD-1 mice using a syringe containing a peptide solution. Due to absence of coagulation activators (e.g. glass surfaces and damaged cells), visible blood clotting was prevented allowing to study peptide degradation for one hour. The remaining peptide was quantified and the degradation products were identified using mass spectrometry. When the degradation rates (half-life times) were compared to serum derived freshly from the same animal and commercial serum and plasma samples, peptides of three different families showed indeed considerably different stabilities. Generally, peptides were faster degraded in serum than in plasma, but surprisingly all peptides were more stable in fresh blood and the order of degradation rates among the peptides varied among the six different incubation experiments. This indicates, that proteolytic degradation of peptide-based therapeutics may often be misleading stimulating efforts to stabilize peptides at degradation sites relevant only in vitro, i.e., for serum or plasma stability assays, but of lower importance in vivo.

Formulation and coating of microneedles with inactivated influenza virus to improve vaccine stability and immunogenicity

PubMed Central

Kim, Yeu-Chun; Quan, Fu-Shi; Compans, Richard W.; Kang, Sang-Moo; Prausnitz, Mark R.

2009-01-01

Microneedle patches coated with solid-state influenza vaccine have been developed to improve vaccine efficacy and patient coverage. However, dip coating microneedles with influenza vaccine can reduce antigen activity. In this study, we sought to determine the experimental factors and mechanistic pathways by which inactivated influenza vaccine can lose activity, as well as develop and assess improved microneedle coating formulations that protect the antigen from activity loss. After coating microneedles using a standard vaccine formulation, antigenicity was reduced to just 2%, as measured by hemagglutination activity. The presence of carboxymethylcellulose, which was added to increase viscosity of the coating formulation, was shown to contribute to vaccine activity loss. After screening a panel of candidate stabilizers, the addition of trehalose to the coating formulation was shown to protect the antigen and retain 48–82% antigen activity for all three major strains of seasonal influenza: H1N1, H3N2 and B. Influenza vaccine coated in this way also exhibited thermal stability, such that activity loss was independent of temperature over the range of 4 – 37°C for 24 h. Dynamic light scattering measurements showed that antigen activity loss was associated with virus particle aggregation, and that stabilization using trehalose largely blocked this aggregation. Finally, microneedles using an optimized vaccine coating formulation were applied to the skin to vaccinate mice. Microneedle vaccination induced robust systemic and functional antibodies and provided complete protection against lethal challenge infection similar to conventional intramuscular injection. Overall, these results show that antigen activity loss during microneedle coating can be largely prevented through optimized formulation and that stabilized microneedle patches can be used for effective vaccination. PMID:19840825

Structural rearrangement of β-lactoglobulin at different oil-water interfaces and its effect on emulsion stability.

PubMed

Zhai, Jiali; Wooster, Tim J; Hoffmann, Søren V; Lee, Tzong-Hsien; Augustin, Mary Ann; Aguilar, Marie-Isabel

2011-08-02

Understanding the factors that control protein structure and stability at the oil-water interface continues to be a major focus to optimize the formulation of protein-stabilized emulsions. In this study, a combination of synchrotron radiation circular dichroism spectroscopy, front-face fluorescence spectroscopy, and dual polarization interferometry (DPI) was used to characterize the conformation and geometric structure of β-lactoglobulin (β-Lg) upon adsorption to two oil-water interfaces: a hexadecane-water interface and a tricaprylin-water interface. The results show that, upon adsorption to both oil-water interfaces, β-Lg went through a β-sheet to α-helix transition with a corresponding loss of its globular tertiary structure. The degree of conformational change was also a function of the oil phase polarity. The hexadecane oil induced a much higher degree of non-native α-helix compared to the tricaprylin oil. In contrast to the β-Lg conformation in solution, the non-native α-helical-rich conformation of β-Lg at the interface was resistant to further conformational change upon heating. DPI measurements suggest that β-Lg formed a thin dense layer at emulsion droplet surfaces. The effects of high temperature and the presence of salt on these β-Lg emulsions were then investigated by monitoring changes in the ζ-potential and particle size. In the absence of salt, high electrostatic repulsion meant β-Lg-stabilized emulsions were resistant to heating to 90 °C. Adding salt (120 mM NaCl) before or after heating led to emulsion flocculation due to the screening of the electrostatic repulsion between colloidal particles. This study has provided insight into the structural properties of proteins adsorbed at the oil-water interface and has implications in the formulation and production of emulsions stabilized by globular proteins.

Coiled-coil destabilizing residues in the group A Streptococcus M1 protein are required for functional interaction.

PubMed

Stewart, Chelsea M; Buffalo, Cosmo Z; Valderrama, J Andrés; Henningham, Anna; Cole, Jason N; Nizet, Victor; Ghosh, Partho

2016-08-23

The sequences of M proteins, the major surface-associated virulence factors of the widespread bacterial pathogen group A Streptococcus, are antigenically variable but have in common a strong propensity to form coiled coils. Paradoxically, these sequences are also replete with coiled-coil destabilizing residues. These features are evident in the irregular coiled-coil structure and thermal instability of M proteins. We present an explanation for this paradox through studies of the B repeats of the medically important M1 protein. The B repeats are required for interaction of M1 with fibrinogen (Fg) and consequent proinflammatory activation. The B repeats sample multiple conformations, including intrinsically disordered, dissociated, as well as two alternate coiled-coil conformations: a Fg-nonbinding register 1 and a Fg-binding register 2. Stabilization of M1 in the Fg-nonbinding register 1 resulted in attenuation of Fg binding as expected, but counterintuitively, so did stabilization in the Fg-binding register 2. Strikingly, these register-stabilized M1 proteins gained the ability to bind Fg when they were destabilized by a chaotrope. These results indicate that M1 stability is antithetical to Fg interaction and that M1 conformational dynamics, as specified by destabilizing residues, are essential for interaction. A "capture-and-collapse" model of association accounts for these observations, in which M1 captures Fg through a dynamic conformation and then collapses into a register 2-coiled coil as a result of stabilization provided by binding energy. Our results support the general conclusion that destabilizing residues are evolutionarily conserved in M proteins to enable functional interactions necessary for pathogenesis.

Soil aggregate stability and wind erodible fraction in a semi-arid environment of White Nile State, Sudan

NASA Astrophysics Data System (ADS)

Elhaja, Mohamed Eltom; Ibrahim, Ibrahim Saeed; Adam, Hassan Elnour; Csaplovics, Elmar

2014-11-01

One of the most important recent issues facing White Nile State, Sudan, as well as Sub Saharan Africa, is the threat of continued land degradation and desertification as a result of climatic factors and human activities. Remote sensing and satellites imageries with multi-temporal and spectral and GIS capability, plays a major role in developing a global and local operational capability for monitoring land degradation and desertification in dry lands, as well as in White Nile State. The process of desertification in form of sand encroachment in White Nile State has increased rapidly, and much effort has been devoted to define and study its causes and impacts. This study depicts the capability afforded by remote sensing and GIS to analyze and map the aggregate stability as indicator for the ability of soil to wind erosion process in White Nile State by using Geo-statistical techniques. Cloud-free subset Landsat; Enhance Thematic Mapper plus (ETM +) scenes covering the study area dated 2008 was selected in order to identify the different features covering the study area as well as to make the soil sampling map. Wet-sieving method was applied to determine the aggregate stability. The geo-statistical methods in EARDAS 9.1 software was used for mapping the aggregate stability. The results showed that the percentage of aggregate stability ranged from (0 to 61%) in the study area, which emphasized the phenomena of sand encroachment from the western part (North Kordofan) to the eastern part (White Nile State), following the wind direction. The study comes out with some valuable recommendations and comments, which could contribute positively in reducing sand encroachments

Effect of Nickel Concentration on Bias Reliability and Thermal Stability of Thin-Film Transistors Fabricated by Ni-Metal-Induced Crystallization

NASA Astrophysics Data System (ADS)

Lai, Ming-Hui; Sermon Wu, YewChung; Huang, Jung-Jie

2012-01-01

Ni-metal-induced crystallization (MIC) of amorphous Si (α-Si) has been employed to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Although the high leakage current is a major issue in the performance of conventional MIC-TFTs since Ni contamination induces deep-level state traps, it can be greatly improved by using well-known technologies to reduce Ni contamination. However, for active-matrix organic light-emitting diode (AMOLED) display applications, the bias reliability and thermal stability are major concerns especially when devices are operated under a hot carrier condition and in a high-temperature environment. It will be interesting to determine how the bias reliability and thermal stability are affected by the reduction of Ni concentration. In the study, the effect of Ni concentration on bias reliability and thermal stability was investigated. We found that a device exhibited high immunity against hot-carrier stress and elevated temperatures. These findings demonstrated that reducing the Ni concentration in MIC films was also beneficial for bias reliability and thermal stability.

FACTORS AFFECTING DISINFECTION AND STABILIZATION OF SEWAGE SLUDGE

EPA Science Inventory

Effective disinfection and stabilization of sewage sludge prior to land application is essential to not only protect human health, but also to convince the public of its benefits and safety. A basic understanding of the key factors involved in producing a stable biosolid product ...

Photo, thermal and chemical degradation of riboflavin

PubMed Central

Kazi, Sadia Hafeez; Ahmed, Sofia; Anwar, Zubair; Ahmad, Iqbal

2014-01-01

Summary Riboflavin (RF), also known as vitamin B2, belongs to the class of water-soluble vitamins and is widely present in a variety of food products. It is sensitive to light and high temperature, and therefore, needs a consideration of these factors for its stability in food products and pharmaceutical preparations. A number of other factors have also been identified that affect the stability of RF. These factors include radiation source, its intensity and wavelength, pH, presence of oxygen, buffer concentration and ionic strength, solvent polarity and viscosity, and use of stabilizers and complexing agents. A detailed review of the literature in this field has been made and all those factors that affect the photo, thermal and chemical degradation of RF have been discussed. RF undergoes degradation through several mechanisms and an understanding of the mode of photo- and thermal degradation of RF may help in the stabilization of the vitamin. A general scheme for the photodegradation of RF is presented. PMID:25246959

Interaction between xanthan gum and cationic cellulose JR400 in aqueous solution.

PubMed

Li, Haiping; Hou, Wanguo; Li, Xiuzhi

2012-06-05

The electrostatic and hydrogen bonding interactions between xanthan gum (XG) and semisynthetic cationic cellulose (JR400) in aqueous solution are investigated via stability map, FT-IR spectra, thermogravimetric analysis, potentiometric measurement and rheological method. The stability map shows three regions, a stable region with XG as the major component, a flocculated region and another stable region with JR400 as the major component. The stability of mixing system depends on both the concentration fraction of JR400 (fJR) and the overlapping concentrations of these two polymers. In the region near the stoichiometric fJR, the mixture shows stoichiometric flocculation, which is independent of the total polymer concentration. However, in the regions away from the stoichiometric fJR, the mixtures are stable when the concentration of major polymer component is higher than its overlapping concentration. In stable regions, the electrostatic and hydrogen bonding interactions can enhance the viscosity of mixing system at appropriate fJR values. Copyright © 2012 Elsevier Ltd. All rights reserved.

Postural Stability in Older Adults With Alzheimer Disease.

PubMed

Mesbah, Normala; Perry, Meredith; Hill, Keith D; Kaur, Mandeep; Hale, Leigh

2017-03-01

The prevalence of adults with Alzheimer disease (AD) aged >65 years is increasing and estimated to quadruple by 2051. The aim of this study was to investigate postural stability in people with mild to moderate AD and factors contributing to postural instability compared with healthy peers (controls). A computerized systematic search of databases and a hand search of reference lists for articles published from 1984 onward (English-language articles only) were conducted on June 2, 2015, using the main key words "postural stability" and "Alzheimer's disease." Sixty-seven studies were assessed for eligibility (a confirmed diagnosis of AD, comparison of measured postural stability between participants with AD and controls, measured factors potentially contributing to postural instability). Data were extracted, and Downs and Black criteria were applied to evaluate study quality. Eighteen articles were analyzed using qualitative synthesis and reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Strength of evidence was guided by the Grading of Recommendations Assessment, Development and Evaluation. Strong evidence was found that: (1) older adults with mild to moderate AD have reduced static and functional postural stability compared with healthy peers (controls) and (2) attentional demand during dual-task activity and loss of visual input were key factors contributing to postural instability. Deta-analysis was not possible due to heterogeneity of the data. Postural stability is impaired in older adults with mild to moderate AD. Decreasing visual input and concentrating on multiple tasks decrease postural stability. To reduce falls risk, more research discerning appropriate strategies for the early identification of impairment of postural stability is needed. Standardization of population description and consensus on outcome measures and the variables used to measure postural -instability and its contributing factors are necessary to ensure meaningful synthesis of data. © 2017 American Physical Therapy Association

Technology Demonstration Summary Site Program Demonstration Test Soliditech Inc Solidification-stabilization Process

EPA Science Inventory

The major objective of the Soliditech, Inc., SITE demonstration was to develop reliable performance and cost information about the Soliditech solidification, stabilization technology. The Soliditech process mixes hazardous waste materials with Portland cement or pozzolanic m...

Design parameters and methodology for mechanically stabilized earth (MSE) walls.

DOT National Transportation Integrated Search

2014-10-01

Since its appearance in 1970s, mechanically stabilized earth (MSE) walls have become a majority among all types of retaining walls due to their economics and satisfactory performance. The Texas Department of Transportation (TxDOT) has primarily adopt...

Functional impairment in patients with major depressive disorder: the 2-year PERFORM study

PubMed Central

Hammer-Helmich, Lene; Haro, Josep Maria; Jönsson, Bengt; Tanguy Melac, Audrey; Di Nicola, Sylvie; Chollet, Julien; Milea, Dominique; Rive, Benoît; Saragoussi, Delphine

2018-01-01

Background The Prospective Epidemiological Research on Functioning Outcomes Related to Major depressive disorder (PERFORM) study describes the course of depressive symptoms, perceived cognitive symptoms, and functional impairment over 2 years in outpatients with major depressive disorder (MDD) and investigates the patient-related factors associated with functional impairment. Methods This was a 2-year observational study in 1,159 outpatients with MDD aged 18–65 years who were either initiating antidepressant monotherapy or undergoing their first switch of antidepressant. Functional impairment was assessed by the Sheehan Disability Scale and the Work Productivity and Activity Impairment questionnaire. Patients assessed depression severity using the nine-item Patient Health Questionnaire and severity of perceived cognitive symptoms using the five-item Perceived Deficit Questionnaire. To investigate which patient-related factors were associated with functional impairment, univariate analyses of variance were performed to identify relevant factors that were then included in multivariate analyses of covariance at baseline, month 2, months 6 and 12 combined, and months 18 and 24 combined. Results The greatest improvement in depressive symptoms, perceived cognitive symptoms, and functional impairment was seen immediately (within 2 months) following initiation or switch of antidepressant therapy, followed by more gradual improvement and long-term stabilization. Improvement in perceived cognitive symptoms was less marked than improvement in depressive symptoms during the acute treatment phase. Functional impairment in patients with MDD was not only associated with severity of depressive symptoms but also independently associated with severity of perceived cognitive symptoms when adjusted for depression severity throughout the 2 years of follow-up. Conclusion These findings highlight the burden of functional impairment in MDD and the importance of recognizing and managing cognitive symptoms in daily practice. PMID:29386897

Functional impairment in patients with major depressive disorder: the 2-year PERFORM study.

PubMed

Hammer-Helmich, Lene; Haro, Josep Maria; Jönsson, Bengt; Tanguy Melac, Audrey; Di Nicola, Sylvie; Chollet, Julien; Milea, Dominique; Rive, Benoît; Saragoussi, Delphine

2018-01-01

The Prospective Epidemiological Research on Functioning Outcomes Related to Major depressive disorder (PERFORM) study describes the course of depressive symptoms, perceived cognitive symptoms, and functional impairment over 2 years in outpatients with major depressive disorder (MDD) and investigates the patient-related factors associated with functional impairment. This was a 2-year observational study in 1,159 outpatients with MDD aged 18-65 years who were either initiating antidepressant monotherapy or undergoing their first switch of antidepressant. Functional impairment was assessed by the Sheehan Disability Scale and the Work Productivity and Activity Impairment questionnaire. Patients assessed depression severity using the nine-item Patient Health Questionnaire and severity of perceived cognitive symptoms using the five-item Perceived Deficit Questionnaire. To investigate which patient-related factors were associated with functional impairment, univariate analyses of variance were performed to identify relevant factors that were then included in multivariate analyses of covariance at baseline, month 2, months 6 and 12 combined, and months 18 and 24 combined. The greatest improvement in depressive symptoms, perceived cognitive symptoms, and functional impairment was seen immediately (within 2 months) following initiation or switch of antidepressant therapy, followed by more gradual improvement and long-term stabilization. Improvement in perceived cognitive symptoms was less marked than improvement in depressive symptoms during the acute treatment phase. Functional impairment in patients with MDD was not only associated with severity of depressive symptoms but also independently associated with severity of perceived cognitive symptoms when adjusted for depression severity throughout the 2 years of follow-up. These findings highlight the burden of functional impairment in MDD and the importance of recognizing and managing cognitive symptoms in daily practice.

Stability of cyanocobalamin in sugar-coated tablets.

PubMed

Ohmori, Shinji; Kataoka, Masumi; Koyama, Hiroyoshi

2007-06-07

The purpose of this study was to clarify the stability of cyanocobalamin (VB(12)-CN) in sugar-coated tablets containing fursultiamine hydrochloride (TTFD-HCl), riboflavin (VB(2)), and pyridoxine hydrochloride (VB(6)), and to identify the factors affecting the stability of VB(12)-CN in these sugar-coated tablets. The stability of VB(12)-CN was investigated using high-performance liquid chromatography while decomposition was evaluated kinetically. The decomposition of VB(12)-CN in sugar-coated tablets with high equilibrium relative humidity (more than 60%) under closed conditions showed complex kinetics and followed an Avrami-Erofe'ev equation, which expresses a random nucleation (two-dimensional growth of nuclei) model. We showed that equilibrium relative humidity, the incorporation of VB(2) and VB(6), and sugar coating, are the main factors influencing decomposition and that these factors cause the complex decomposition kinetics.

Effect of Surface Curvature and Chemistry on Protein Stability, Adsorption and Aggregation

NASA Astrophysics Data System (ADS)

Radhakrishna, Mithun

Enzyme immobilization has been of great industrial importance because of its use in various applications like bio-fuel cells, bio-sensors, drug delivery and bio-catalytic films. Although research on enzyme immobilization dates back to the 1970's, it has been only in the past decade that scientists have started to address the problems involved systematically. Most of the previous works on enzyme immobilization have been retrospective in nature i.e enzymes were immobilized on widely used substrates without a compatibility study between the enzyme and the substrate. Consequently, most of the enzymes lost their activity upon immobilization onto these substrates due to many governing factors like protein-surface and inter-protein interactions. These interactions also play a major role biologically in cell signaling, cell adhesion and inter-protein interactions specifically is believed to be the major cause for neurodegenerative diseases like Alzheimer's and Parkinson's disease. Therefore understanding the role of these forces on proteins is the need of the hour. In my current research, I have mainly focused on two factors a) Surface Curvature b) Surface Chemistry as both of these play a pivotal role in influencing the activity of the enzymes upon immobilization. I study the effect of these factors computationally using a stochastic method known as Monte Carlo simulations. My research work carried out in the frame work of a Hydrophobic-Polar (HP) lattice model for the protein shows that immobilizing enzymes inside moderately hydrophilic or hydrophobic pores results in an enhancement of the enzymatic activity compared to that in the bulk. Our results also indicate that there is an optimal value of surface curvature and hydrophobicity/hydrophilicity where this enhancement of enzymatic activity is highest. Further, our results also show that immobilization of enzymes inside hydrophobic pores of optimal sizes are most effective in mitigating protein-aggregation. These results provide us a rationale to understand the role of chaperonins in protein folding and disaggregation. Our results indicate that strong protein-surface interactions and confinement inducement stability inside pores makes it best suitable for enzyme immobilization.

Sensitivity of the transport and retention of stabilized silver nanoparticles to physicochemical factors

USDA-ARS?s Scientific Manuscript database

Saturated sand-packed column experiments were conducted to investigate the influence of physicochemical factors on the transport and retention of surfactant stabilized silver nanoparticles (AgNPs). The normalized concentration in breakthrough curves (BTCs) of AgNPs increased with a decrease in solut...

Stability of epitheliotrophic factors in autologous serum eye drops from chronic Stevens-Johnson syndrome dry eye compared to non-autoimmune dry eye.

PubMed

Phasukkijwatana, Nopasak; Lertrit, Patcharee; Liammongkolkul, Sompong; Prabhasawat, Pinnita

2011-09-01

To compare the concentrations of epitheliotrophic factors in autologous serum eye drops (ASE) prepared from sera of chronic Stevens-Johnson syndrome (SJS) patients with dry eyes to those prepared from non-autoimmune dry eye controls and to study the stability of the epitheliotrophic factors in different storage conditions. Twenty-percent ASE were prepared from 10 chronic SJS patients with dry eyes and 10 age-matched non-autoimmune dry eye controls. The concentrations of major epitheliotrophic factors comprising epidermal growth factor (EGF), transforming growth factor-beta1 (TGF-β1), transforming growth factor-beta2 (TGF-β2), and fibronectin in those ASE preparations were determined by enzyme-linked immunosorbent assay (ELISA) at baseline and after different storage conditions: at 4 °C for 1 week and 1 month; and at -20 °C for 1, 3 and 6 months. There were no significant differences in the concentrations of EGF, TGF-β1, TGF-β2 and fibronectin in 20% ASE between the SJS and control groups (EGF: 176.9 ± 40.9 vs. 185.5 ± 36.9 pg/mL, TGF-β1: 9.5 ± 2.1 vs. 9.5 ± 1.9 ng/mL, TGF-β2: 55.3 ± 30.0 vs. 63.91 ± 45.6 pg/mL and fibronectin: 70.5 ± 20.2 vs. 62.2 ± 21.3 µg/mL, respectively). These factors were stable at 4 °C for up to 1 month. Storage at -20 °C for up to 6 months resulted in a slight decrease in TGF-β1 (SJS: from 9.5-8.4 ng/mL, p < 0.01 and control: from 9.5-8.1 ng/mL, p < 0.01). The results suggested that the epitheliotrophic capacity of ASE from chronic SJS should be comparable to those from non-autoimmune dry eye patients, and that ASE should be sufficiently stable for up to 6 months, if stored properly at -20 °C.

Slope Stability Analysis for Shallow Landslides using TRIGRS: A Case Study for Sta. Cruz, Zambales, Philippines

NASA Astrophysics Data System (ADS)

Mendoza, J. P. A.

2016-12-01

The Philippines, being located in the circum-Pacific, bounded by multiple subduction zones, open seas and ocean, is one of the most hazard-prone countries in the world (Benson, 1997). This widespread recurrence of natural hazards in the country requires much attention for disaster management (Aurelio, 2006). On the average, 21 typhoons enter the Philippine area of responsibility annually with 6-9 making a landfall. Several rainfall-induced landslide events are reported annually particularly during and after the inundation of major typhoons which imposes hazards to communities and causes destruction of properties due to the moving mass and possible flash floods it may induce. Shallow landslides are the most commonly observed failure involving soil-mantled slopes and are considered major geohazards, often causing property damage and other economic loss. Hence numerous studies on landslide susceptibility including numerical models based on infinite slope equation are used in order to identify slopes prone to occurrences of shallow landslides. The study aims to determine the relationships between the slope and elevation to the factor of safety for laterite-mantled topography by incorporating precipitation values in the determination of landslide susceptibility. Using a DEM, flow direction map and slope map of the Sta Cruz (Zambales, Philippines), the FORTRAN based program TRIGRS, was used to generate the values for the factors of safety in the study area. Overlays with a generated slope map and elevation map were used to determine relationships of the mentioned factors and the factors of safety. A slope in a topography mantled with lateritic soil will fail at a slope angle higher than 20 degrees. Generally, the factor of safety decreases as the slope angle increases; this increases the probability and risk of slope failure. Elevation has no bearing on the computation for the factor of safety. The factor of safety is heavily dependent on the slope angle. The value of generated factor of safety coincides with the published geohazard map from Mines and Geosciences Bureau(MGB).

Map showing landslide susceptibility in Prince Georges County, Maryland

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

Pomeroy, J.S.

1989-01-01

Prince Georges County was identified during a statewide investigation of landslide susceptibility (MF-2048) as the county with the most serious slope-stability problems. This map uses a ranking system ranging from 1 (nil to very low susceptibility) to 4 (moderate to severe susceptibility). Geologic factors and precipitation are major elements in the initiation of landslides in the county. The Potomac Group and the Marlboro Clay are the most slideprone units. This map should enable users to make a rapid, generalized evaluation of the potential for mass movement. Planners, engineers, soil scientists, geologist, university faculty, and elected officials should find it usefulmore » in the assessment of slope hazards for county-wide analyses.« less

From structure to mechanism-understanding initiation of DNA replication.

PubMed

Riera, Alberto; Barbon, Marta; Noguchi, Yasunori; Reuter, L Maximilian; Schneider, Sarah; Speck, Christian

2017-06-01

DNA replication results in the doubling of the genome prior to cell division. This process requires the assembly of 50 or more protein factors into a replication fork. Here, we review recent structural and biochemical insights that start to explain how specific proteins recognize DNA replication origins, load the replicative helicase on DNA, unwind DNA, synthesize new DNA strands, and reassemble chromatin. We focus on the minichromosome maintenance (MCM2-7) proteins, which form the core of the eukaryotic replication fork, as this complex undergoes major structural rearrangements in order to engage with DNA, regulate its DNA-unwinding activity, and maintain genome stability. © 2017 Riera et al.; Published by Cold Spring Harbor Laboratory Press.

Rotor vibration reduction with polymeric sectors

NASA Astrophysics Data System (ADS)

Dutt, J. K.; Toi, T.

2003-05-01

This work has been undertaken principally with an idea to improving the dynamic performance of rotor-shaft systems, which often suffer from two major problems (a) resonance and (b) loss of stability, resulting in excessive vibration of such systems. Polymeric material in the form of sectors has been considered in this work as bearing supports. Polymeric material has been considered in this work as both stiffness and loss factor of such materials varies with the frequency of excitation. Stiffness and loss factor have been found out for the proposed support system comprising of polymeric sectors. Depending upon the frequency of excitation the system matrix, in this case, changes and dynamic performance of the rotor-shaft system also changes accordingly. Here in this work avoidance of resonance and application of optimum damping in the support have been investigated by finding out the optimum dimension, i.e., the optimum thickness and optimum length of the sectors. It has been theoretically found that use of such sectors reduces the rotor unbalanced response, increases the stability limit speed for simple rotor-shaft systems and thus improves the dynamic characteristics. Parameters of the system have been presented in terms of non-dimensional quantities. Many examples have been presented in support of the conclusion. The life of such supports, particularly in the presence of chemicals and other reagents has not been investigated.

Relationship between locked modes and thermal quenches in DIII-D

NASA Astrophysics Data System (ADS)

Sweeney, R.; Choi, W.; Austin, M.; Brookman, M.; Izzo, V.; Knolker, M.; La Haye, R. J.; Leonard, A.; Strait, E.; Volpe, F. A.; The DIII-D Team

2018-05-01

Locked modes are known to be one of the major causes of disruptions, but the physical mechanisms by which locking leads to disruptions are not well understood. Here we analyze the evolution of the temperature profile in the presence of multiple coexisting locked modes during partial and full thermal quenches. Partial quenches are often observed to be an initial, distinct stage in the full thermal quench. Near the onset of partial quenches, locked island O-points are observed to align with each other on the midplane, and their widths are sufficient to overlap each other, as indicated by the Chirikov parameter. Energy conservation analysis of one partial thermal quench shows that the energy lost is both radiated in the divertor region, and conducted or convected to the divertor. Nonlinear resistive magnetohydrodynamic simulations support the interpretation of stochastic fields causing a partial axisymmetric collapse, though the simulated temperature profile exhibits less degradation than the experimental profiles. In discharges with minimum values of the safety factor above  ∼1.2, locked modes are observed to self-stabilize by inducing, possibly via double tearing modes, a minor disruption that removes their neoclassical drive. These high q min discharges often exhibit relatively low ratios of the plasma internal inductance to the safety factor at 95% of the poloidal flux, which might imply classical stability, in agreement with the decay of the mode when the neoclassical drive is removed.

Targeted inactivation of the mouse locus encoding coagulation factor XIII-A: hemostatic abnormalities in mutant mice and characterization of the coagulation deficit.

PubMed

Lauer, Peter; Metzner, Hubert J; Zettlmeissl, Gerd; Li, Meng; Smith, Austin G; Lathe, Richard; Dickneite, Gerhard

2002-12-01

Blood coagulation factor XIII (FXIII) promotes cross-linking of fibrin during blood coagulation; impaired clot stabilization in human genetic deficiency is associated with marked pathologies of major clinical impact, including bleeding symptoms and deficient wound healing. To investigate the role of FXIII we employed homologous recombination to generate a targeted deletion of the inferred exon 7 of the FXIII-A gene. FXIII transglutaminase activity in plasma was reduced to about 50% in mice heterozygous for the mutant allele, and was abolished in homozygous null mice. Plasma fibrin gamma-dimerization was also indetectable in the homozygous deficient animals, confirming the absence of activatable FXIII. Homozygous mutant mice were fertile, although reproduction was impaired. Bleeding episodes, hematothorax, hematoperitoneum and subcutaneous hemorrhage in mutant mice were associated with reduced survival. Arrest of tail-tip bleeding in FXIII-A deficient mice was markedly and significantly delayed; replacement of mutant mice with human plasma FXIII (Fibrogammin P) restored bleeding time to within the normal range. Thrombelastography (TEG) experiments demonstrated impaired clot stabilization in FXIII-A mutant mice, replacement with human FXIII led to dose-dependent TEG normalization. The mutant mice thus reiterate some key features of the human genetic disorder: they will be valuable in assessing the role of FXIII in other associated pathologies and the development of new therapies.

Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

NASA Technical Reports Server (NTRS)

Quigley, Hervey C.; Anderson, Seth B.; Innis, Robert C.

1960-01-01

A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg.

Radical-cationic gaseous amino acids: a theoretical study.

PubMed

Sutherland, Kailee N; Mineau, Philippe C; Orlova, Galina

2007-08-16

Three major forms of gaseous radical-cationic amino acids (RCAAs), keto (COOH), enolic (C(OH)OH), and zwitterionic (COO(-)), as well as their tautomers, are examined for aliphatic Ala(.+), Pro(.+), and Ser(.+), sulfur-containing Cys(.+), aromatic Trp(.+), Tyr(.+), and Phe(.+), and basic His(.+). The hybrid B3LYP exchange-correlation functional with various basis sets along with the highly correlated CCSD(T) method is used. For all RCAAs considered, the main stabilizing factor is spin delocalization; for His(.+), protonation of the basic side chain is equally important. Minor stabilizing factors are hydrogen bonding and 3e-2c interactions. An efficient spin delocalization along the N-C(alpha)-C(O-)O moiety occurs upon H-transfer from C(alpha) to the carboxylic group to yield the captodative enolic form, which is the lowest-energy isomer for Ala(.+), Pro(.+), Ser(.+), Cys(.+), Tyr(.+), and Phe(.+). This H-transfer occurs in a single step as a 1,3-shift through the sigma-system. For His(.+), the lowest-energy isomer is formed upon H-transfer from C(alpha) to the basic side chain, which results in a keto form, with spin delocalized along the N-C(alpha)-C=O fragment. Trp(.+) is the only RCAA that favors spin delocalization over an aromatic system given the low ionization energy of indole. The lowest-energy isomer of Trp(.+) is a keto form, with no H-transfer.

Effect of deuteration on metabolism and clearance of Nerispirdine (HP184) and AVE5638.

PubMed

Schofield, Joseph; Derdau, Volker; Atzrodt, Jens; Zane, Patricia; Guo, Zuyu; van Horn, Robert; Czepczor, Valérie; Stoltz, Axelle; Pardon, Magalie

2015-07-01

Replacing hydrogen with deuterium as a means of altering ADME properties of drug molecules has recently enjoyed a renaissance, such that at least two deuterated chemical entities are currently in clinical development. Although most research in this area aims to increase the metabolic stability, and hence half-life of the active species, experience has shown that prediction of the in vivo behaviour of deuterated molecules is difficult and depends on multiple factors including the complexity of the metabolic scheme, the enzymes involved and hence the mechanism of the rate-determining step in the biotransformation. In an effort to elucidate some of these factors we examined the metabolic behaviour of two molecules from the Sanofi portfolio in a range of in vitro and in vivo systems. Although some key metabolic reactions of the acetylcholine release stimulator HP184 4 were slowed in vitro and in vivo when deuterium was present at the sites of metabolism, this did not translate to an increase in overall metabolic stability. By contrast, the tryptase inhibitor AVE5638 13 was much more metabolically stable in vitro in its deuterated form than when unlabelled. These results indicate that it could be of value to concentrate efforts in this area to molecules which are metabolised by a major pathway that involves enzymes of the amine oxidase family or other low-capacity enzyme families. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accelerated loading evaluation of stabilized BCS layers in pavement performance.

DOT National Transportation Integrated Search

2012-03-01

BCS is short for blended calcium sulfate, a recycled fluorogypsum mixture that has been used in Louisiana as a roadway base for more than a decade. : Without further chemical stabilization, the major concern of using raw BCS as a pavement structural ...

0-6716 : design parameters and methodology for mechanically stabilized earth (MSE) walls.

DOT National Transportation Integrated Search

2013-08-01

Since their appearance in the 1970s, mechanically : stabilized earth (MSE) walls have become a majority : among all types of retaining walls due to their economics : and satisfactory performance. The Texas Department of : Transportation (TxDOT) has p...

Beam Stability R&D for the APS MBA Upgrade

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

Sereno, Nicholas S.; Arnold, Ned D.; Bui, Hanh D.

2015-01-01

Beam diagnostics required for the APS Multi-bend acromat (MBA) are driven by ambitious beam stability requirements. The major AC stability challenge is to correct rms beam motion to 10% the rms beam size at the insertion device source points from0.01 to 1000 Hz. The vertical plane represents the biggest challenge forAC stability, which is required to be 400 nm rms for a 4-micron vertical beam size. In addition to AC stability, long-term drift over a period of seven days is required to be 1 micron or less. Major diagnostics R&D components include improved rf beam position processing using commercially availablemore » FPGA-based BPM processors, new X-ray beam position monitors based on hard X-ray fluorescence from copper and Compton scattering off diamond, mechanical motion sensing to detect and correct long-term vacuum chamber drift, a new feedback system featuring a tenfold increase in sampling rate, and a several-fold increase in the number of fast correctors and BPMs in the feedback algorithm. Feedback system development represents a major effort, and we are pursuing development of a novel algorithm that integrates orbit correction for both slow and fast correctors down to DC simultaneously. Finally, a new data acquisition system (DAQ) is being developed to simultaneously acquire streaming data from all diagnostics as well as the feedback processors for commissioning and fault diagnosis. Results of studies and the design effort are reported.« less

Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads.

PubMed

Lin, Shen-Fu; Chen, Ying-Chen; Chen, Ray-Neng; Chen, Ling-Chun; Ho, Hsiu-O; Tsung, Yu-Han; Sheu, Ming-Thau; Liu, Der-Zen

2016-01-01

There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads

PubMed Central

Lin, Shen-Fu; Chen, Ying-Chen; Chen, Ray-Neng; Chen, Ling-Chun; Ho, Hsiu-O; Tsung, Yu-Han; Sheu, Ming-Thau; Liu, Der-Zen

2016-01-01

There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds. PMID:27093175

Observed Personality in Childhood: Psychometric and Behavioral Genetic Evidence of Two Broad Personality Factors

PubMed Central

Wang, Zhe; Chen, Nan; Petrill, Stephen A.; Deater-Deckard, Kirby

2014-01-01

We examined broad dimensions of children’s personalities (total n = 1056; age = 3.5 to 12 years) based on observers’ perceptions following a few hours of structured interaction. Siblings’ behaviors during a two-hour cognitive assessment in the home were rated separately by two different observers. Exploratory and confirmatory factor analyses clearly revealed a two-factor solution in three different samples. There was correspondence between parent-rated temperament and the observer-rated factors. Cross-sectional analyses indicated lower Plasticity among older children and higher Stability among older children. Sex differences were negligible. Plasticity and Stability were correlated in the .2 to .3 range. Most of the sibling similarity in the Plasticity was due to additive genetic influences, whereas most sibling similarity in Stability was attributable to shared environmental influences. The findings implicate a biometric factor structure to childhood personality that fits well with emerging bio-social theories of personality development. PMID:24932065

Specific muscle stabilizing as home exercises for persistent pelvic girdle pain after pregnancy: a randomized, controlled clinical trial.

PubMed

Gutke, Annelie; Sjödahl, Jenny; Oberg, Birgitta

2010-11-01

To investigate the efficacy of home-based specific stabilizing exercises focusing on the local stabilizing muscles as the only intervention in the treatment of persistent postpartum pelvic girdle pain. A prospective, randomized, single-blinded, clinically controlled study. Eighty-eight women with pelvic girdle pain were recruited 3 months after delivery. The treatment consisted of specific stabilizing exercises targeting the local trunk muscles. The reference group had a single telephone contact with a physiotherapist. Primary outcome was disability measured with Oswestry Disability Index. Secondary outcomes were pain, health-related quality of life (EQ-5D), symptom satisfaction, and muscle function. No significant differences between groups could be found at 3- or 6-month follow-up regarding primary outcome in disability. Within-group comparisons showed some improvement in both groups in terms of disability, pain, symptom satisfaction and muscle function compared with baseline, although the majority still experienced pelvic girdle pain. Treatment with this home-training concept of specific stabilizing exercises targeting the local muscles was no more effective in improving consequences of persistent postpartum pelvic girdle pain than the clinically natural course. Regardless of whether treatment with specific stabilizing exercises was carried out, the majority of women still experienced some back pain almost one year after pregnancy.

Quantifying data retention of perpendicular spin-transfer-torque magnetic random access memory chips using an effective thermal stability factor method

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

Thomas, Luc, E-mail: luc.thomas@headway.com; Jan, Guenole; Le, Son

The thermal stability of perpendicular Spin-Transfer-Torque Magnetic Random Access Memory (STT-MRAM) devices is investigated at chip level. Experimental data are analyzed in the framework of the Néel-Brown model including distributions of the thermal stability factor Δ. We show that in the low error rate regime important for applications, the effect of distributions of Δ can be described by a single quantity, the effective thermal stability factor Δ{sub eff}, which encompasses both the median and the standard deviation of the distributions. Data retention of memory chips can be assessed accurately by measuring Δ{sub eff} as a function of device diameter andmore » temperature. We apply this method to show that 54 nm devices based on our perpendicular STT-MRAM design meet our 10 year data retention target up to 120 °C.« less

Alanine Scanning Mutagenesis Identifies an Asparagine–Arginine–Lysine Triad Essential to Assembly of the Shell of the Pdu Microcompartment

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

Sinha, Sharmistha; Cheng, Shouqiang; Sung, Yea Won

2014-06-01

Bacterial microcompartments (MCPs) are the simplest organelles known. They function to enhance metabolic pathways by confining several related enzymes inside an all-protein envelope called the shell. In this study, we investigated the factors that govern MCP assembly by performing scanning mutagenesis on the surface residues of PduA, a major shell protein of the MCP used for 1,2-propanediol degradation. Biochemical, genetic, and structural analysis of 20 mutants allowed us to determine that PduA K26, N29, and R79 are crucial residues that stabilize the shell of the 1,2-propanediol MCP. In addition, we identify two PduA mutants (K37A and K55A) that impair MCPmore » function most likely by altering the permeability of its protein shell. These are the first studies to examine the phenotypic effects of shell protein structural mutations in an MCP system. The findings reported here may be applicable to engineering protein containers with improved stability for biotechnology applications.« less

Chronic Obstructive Pulmonary Disease: From Injury to Genomic Stability.

PubMed

Sergio, Luiz Philippe da Silva; de Paoli, Flavia; Mencalha, Andre Luiz; da Fonseca, Adenilson de Souza

2017-08-01

Chronic obstructive pulmonary disease (COPD) is the fourth cause of death in the world and it is currently presenting a major global public health challenge, causing premature death from pathophysiological complications and rising economic and social burdens. COPD develops from a combination of factors following exposure to pollutants and cigarette smoke, presenting a combination of both emphysema and chronic obstructive bronchitis, which causes lung airflow limitations that are not fully reversible by bronchodilators. Oxidative stress plays a key role in the maintenance and amplification of inflammation in tissue injury, and also induces DNA damages. Once the DNA molecule is damaged, enzymatic mechanisms act in order to repair the DNA molecule. These mechanisms are specific to repair of oxidative damages, such as nitrogen base modifications, or larger DNA damages, such as double-strand breaks. In addition, there is an enzymatic mechanism for the control of telomere length. All these mechanisms contribute to cell viability and homeostasis. Thus, therapies based on modulation of DNA repair and genomic stability could be effective in improving repair and recovery of lung tissue in patients with COPD.

Evaluation of emulsion emulsified by starch nanocrystal: A preliminary study

NASA Astrophysics Data System (ADS)

Ahmad, Azfar Al Ariff; Lazim, Azwan Mat

2018-04-01

The starch nanocrystals (SNC) used in this study were made of sago starch and prepared by using sulfuric acid hydrolysis of sago starch. The aim of this study is to look at the potential of SNC as and emulsifier. Previously, the SNC underwent analytical analysis in order to understand and evaluate the isolated SNC. The ability of SNC as emulsifier was further investigated in this study. Emulsions with low, medium and high oil content has been prepared in function of different wt% of SNC. The emulsion stability against coalescence for two weeks has also been studied. Results showed that the emulsions prepared are steadily stable after one weeks of storage without any separation and changes. From the observation, there are two major factor contributed to the formation of emulsion and its stability, the SNC concentration and oil content. Relatively, higher percentage of SNC resulting a higher emulsion index, whereas no emulsion was formed if oil content exceeding 50% of the systems. The most suitable formulation to prepare Pickering Emulsion is the oil content around 45% and SNC concentration around 2 - 4%.

Physicochemical characterization of ultrasmall superparamagnetic iron oxide particles (USPIO) for biomedical application as MRI contrast agents

PubMed Central

Di Marco, Mariagrazia; Sadun, Claudia; Port, Marc; Guilbert, Irene; Couvreur, Patrick; Dubernet, Catherine

2007-01-01

Ultrasmall superparamagnetic iron oxide (USPIO) particles are maghemite or magnetite nanoparticles currently used as contrast agent in magnetic resonance imaging. The coatings surrounding the USPIO inorganic core play a major role in both the in vitro stability and, over all, USPIO’s in vivo fate. Different physicochemical properties such as final size, surface charge and coating density are key factors in this respect. Up to now no precise structure – activity relationship has been described to predict entirely the USPIOs stability, as well as their pharmacokinetics and their safety. This review is focused on both the classical and the latest available techniques allowing a better insight in the magnetic core structure and the organic surface of these particles. Concurrently, this work clearly shows the difficulty to obtain a complete physicochemical characterization of USPIOs particles owing to their small dimensions, reaching the analytical resolution limits of many commercial instruments. An extended characterization is therefore necessary to improve the understanding of the properties of USPIOs when dispersed in an aqueous environment and to set the specifications and limits for their conception. PMID:18203428

In-Situ Quantification of the Interfacial Rheological Response of Bacterial Biofilms to Environmental Stimuli

PubMed Central

Rühs, Patrick A.; Böni, Lukas; Fuller, Gerald G.; Inglis, R. Fredrik; Fischer, Peter

2013-01-01

Understanding the numerous factors that can affect biofilm formation and stability remain poorly understood. One of the major limitations is the accurate measurement of biofilm stability and cohesiveness in real-time when exposed to changing environmental conditions. Here we present a novel method to measure biofilm strength: interfacial rheology. By culturing a range of bacterial biofilms on an air-liquid interface we were able to measure their viscoelastic growth profile during and after biofilm formation and subsequently alter growth conditions by adding surfactants or changing the nutrient composition of the growth medium. We found that different bacterial species had unique viscoelastic growth profiles, which was also highly dependent on the growth media used. We also found that we could reduce biofilm formation by the addition of surfactants or changing the pH, thereby altering the viscoelastic properties of the biofilm. Using this technique we were able to monitor changes in viscosity, elasticity and surface tension online, under constant and varying environmental conditions, thereby providing a complementary method to better understand the dynamics of both biofilm formation and dispersal. PMID:24244319

Repetitive DNA loci and their modulation by the non-canonical nucleic acid structures R-loops and G-quadruplexes

PubMed Central

Hall, Amanda C.; Ostrowski, Lauren A.; Mekhail, Karim

2017-01-01

ABSTRACT Cells have evolved intricate mechanisms to maintain genome stability despite allowing mutational changes to drive evolutionary adaptation. Repetitive DNA sequences, which represent the bulk of most genomes, are a major threat to genome stability often driving chromosome rearrangements and disease. The major source of repetitive DNA sequences and thus the most vulnerable constituents of the genome are the rDNA (rDNA) repeats, telomeres, and transposable elements. Maintaining the stability of these loci is critical to overall cellular fitness and lifespan. Therefore, cells have evolved mechanisms to regulate rDNA copy number, telomere length and transposon activity, as well as DNA repair at these loci. In addition, non-canonical structure-forming DNA motifs can also modulate the function of these repetitive DNA loci by impacting their transcription, replication, and stability. Here, we discuss key mechanisms that maintain rDNA repeats, telomeres, and transposons in yeast and human before highlighting emerging roles for non-canonical DNA structures at these repetitive loci. PMID:28406751

Automated potentiometric titrations in KCl/water-saturated octanol: method for quantifying factors influencing ion-pair partitioning.

PubMed

Scherrer, Robert A; Donovan, Stephen F

2009-04-01

The knowledge base of factors influencing ion pair partitioning is very sparse, primarily because of the difficulty in determining accurate log P(I) values of desirable low molecular weight (MW) reference compounds. We have developed a potentiometric titration procedure in KCl/water-saturated octanol that provides a link to log P(I) through the thermodynamic cycle of ionization and partitioning. These titrations have the advantage of being independent of the magnitude of log P, while maintaining a reproducibility of a few hundredths of a log P in the calculated difference between log P neutral and log P ion pair (diff (log P(N - I))). Simple model compounds can be used. The titration procedure is described in detail, along with a program for calculating pK(a)'' values incorporating the ionization of water in octanol. Hydrogen bonding and steric factors have a greater influence on ion pairs than they do on neutral species, yet these factors are missing from current programs used to calculate log P(I) and log D. In contrast to the common assumption that diff (log P(N - I)) is the same for all amines, they can actually vary more than 3 log units, as in our examples. A major factor affecting log P(I) is the ability of water and the counterion to approach the charge center. Bulky substituents near the charge center have a negative influence on log P(I). On the other hand, hydrogen bonding groups near the charge center have the opposite effect by lowering the free energy of the ion pair. The use of this titration method to determine substituent ion pair stabilization values (IPS) should bring about more accurate log D calculations and encourage species-specific QSAR involving log D(N) and log D(I). This work also brings attention to the fascinating world of nature's highly stabilized ion pairs.

Automated Potentiometric Titrations in KCl/Water-Saturated Octanol: Method for Quantifying Factors Influencing Ion-Pair Partitioning

PubMed Central

2009-01-01

The knowledge base of factors influencing ion pair partitioning is very sparse, primarily because of the difficulty in determining accurate log PI values of desirable low molecular weight (MW) reference compounds. We have developed a potentiometric titration procedure in KCl/water-saturated octanol that provides a link to log PI through the thermodynamic cycle of ionization and partitioning. These titrations have the advantage of being independent of the magnitude of log P, while maintaining a reproducibility of a few hundredths of a log P in the calculated difference between log P neutral and log P ion pair (diff (log PN − I)). Simple model compounds can be used. The titration procedure is described in detail, along with a program for calculating pKa′′ values incorporating the ionization of water in octanol. Hydrogen bonding and steric factors have a greater influence on ion pairs than they do on neutral species, yet these factors are missing from current programs used to calculate log PI and log D. In contrast to the common assumption that diff (log PN − I) is the same for all amines, they can actually vary more than 3 log units, as in our examples. A major factor affecting log PI is the ability of water and the counterion to approach the charge center. Bulky substituents near the charge center have a negative influence on log PI. On the other hand, hydrogen bonding groups near the charge center have the opposite effect by lowering the free energy of the ion pair. The use of this titration method to determine substituent ion pair stabilization values (IPS) should bring about more accurate log D calculations and encourage species-specific QSAR involving log DN and log DI. This work also brings attention to the fascinating world of nature’s highly stabilized ion pairs. PMID:19265385

How to measure ecosystem stability? An evaluation of the reliability of stability metrics based on remote sensing time series across the major global ecosystems.

PubMed

De Keersmaecker, Wanda; Lhermitte, Stef; Honnay, Olivier; Farifteh, Jamshid; Somers, Ben; Coppin, Pol

2014-07-01

Increasing frequency of extreme climate events is likely to impose increased stress on ecosystems and to jeopardize the services that ecosystems provide. Therefore, it is of major importance to assess the effects of extreme climate events on the temporal stability (i.e., the resistance, the resilience, and the variance) of ecosystem properties. Most time series of ecosystem properties are, however, affected by varying data characteristics, uncertainties, and noise, which complicate the comparison of ecosystem stability metrics (ESMs) between locations. Therefore, there is a strong need for a more comprehensive understanding regarding the reliability of stability metrics and how they can be used to compare ecosystem stability globally. The objective of this study was to evaluate the performance of temporal ESMs based on time series of the Moderate Resolution Imaging Spectroradiometer derived Normalized Difference Vegetation Index of 15 global land-cover types. We provide a framework (i) to assess the reliability of ESMs in function of data characteristics, uncertainties and noise and (ii) to integrate reliability estimates in future global ecosystem stability studies against climate disturbances. The performance of our framework was tested through (i) a global ecosystem comparison and (ii) an comparison of ecosystem stability in response to the 2003 drought. The results show the influence of data quality on the accuracy of ecosystem stability. White noise, biased noise, and trends have a stronger effect on the accuracy of stability metrics than the length of the time series, temporal resolution, or amount of missing values. Moreover, we demonstrate the importance of integrating reliability estimates to interpret stability metrics within confidence limits. Based on these confidence limits, other studies dealing with specific ecosystem types or locations can be put into context, and a more reliable assessment of ecosystem stability against environmental disturbances can be obtained. © 2013 John Wiley & Sons Ltd.

The Latent Structure and Test-Retest Stability of Connected Language Measures in the Wisconsin Registry for Alzheimer's Prevention (WRAP).

PubMed

Mueller, Kimberly D; Koscik, Rebecca L; Clark, Lindsay R; Hermann, Bruce P; Johnson, Sterling C; Turkstra, Lyn S

2017-11-24

While it is well known that discourse-related language functions are impaired in the dementia phase of Alzheimer's Disease (AD), the presymptomatic temporal course of discourse dysfunction are not known earlier in the course of AD. To conduct discourse-related studies in this phase of AD, validated psychometric instruments are needed. This study investigates the latent structure, validity, and test-retest stability of discourse measures in a late-middle-aged normative group who are relatively free from sporadic AD risk factors. Using a normative sample of 399 participants (mean age = 61), exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) were conducted on 18 measures of connected language derived from picture descriptions. Factor invariance across sex and family history and longitudinal test-retest stability measures were calculated. The EFA revealed a four-factor solution, consisting of semantic, syntax, fluency, and lexical constructs. The CFA model substantiated the structure, and factors were invariant across sex and parental history of AD status. Test-retest stability measures were within acceptable ranges. Results confirm a factor structure that is invariant across sex and parental AD history. The factor structure could be useful in similar cohorts designed to detect early language decline in investigations of preclinical or clinical AD or as outcome measures in clinical prevention trials. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of pH adjustment, homogenization and diafiltration on physicochemical, reconstitution, functional and rheological properties of medium protein milk protein concentrates (MPC70).

PubMed

Meena, Ganga Sahay; Singh, Ashish Kumar; Gupta, Vijay Kumar; Borad, Sanket; Arora, Sumit; Tomar, Sudhir Kumar

2018-04-01

Poor solubility is the major limiting factor in commercial applications of milk protein concentrates (MPC) powders. Retentate treatments such as pH adjustment using disodium phosphate (Na 2 HPO 4 ), also responsible for calcium chelation with homogenization and; its diafiltration with 150 mM NaCl solution were hypothesized to improve the functional properties of treated MPC70 powders. These treatments significantly improved the solubility, heat stability, water binding, dispersibility, bulk density, flowability, buffer index, foaming and emulsifying capacity of treated powders over control. Rheological behaviour of reconstituted MPC solutions was best explained by Herschel Bulkley model. Compared to rough, large globular structures with dents in control; majorly intact, separate, smaller particles of smooth surface, without any aggregation were observed in SEM micrograph of treated powders. Applied treatments are easy, cost-effective and capable to improve functional properties of treated powders that could replace control MPC70 powder in various food applications where protein functionality is of prime importance.

Negative Emotionality and Disconstraint Influence PTSD Symptom Course via Exposure to New Major Adverse Life Events

PubMed Central

Sadeh, Naomi; Miller, Mark W.; Wolf, Erika J.; Harkness, Kate L.

2015-01-01

Identifying the factors that influence stability and change in chronic posttraumatic stress disorder (PTSD) is important for improving clinical outcomes. Using a cross-lagged design, we analyzed the reciprocal effects of personality and PTSD symptoms over time and their effects on stress exposure in a sample of 222 trauma-exposed veterans (ages 23 – 68; 90.5% male). Personality functioning and PTSD were measured approximately 4 years apart, and self-reported exposure to major adverse life events during the interim was also assessed. Negative emotionality positively predicted future PTSD symptoms, and this effect was partially mediated by exposure to new events. Constraint (negatively) indirectly affected PTSD via its association with exposure to new events. There were no significant effects of positive emotionality nor did PTSD symptom severity exert influences on personality over time. Results indicate that high negative affect and disconstraint influence the course of PTSD symptoms by increasing exposure to stressful life events. PMID:25659969

Negative emotionality and disconstraint influence PTSD symptom course via exposure to new major adverse life events.

PubMed

Sadeh, Naomi; Miller, Mark W; Wolf, Erika J; Harkness, Kate L

2015-04-01

Identifying the factors that influence stability and change in chronic posttraumatic stress disorder (PTSD) is important for improving clinical outcomes. Using a cross-lagged design, we analyzed the reciprocal effects of personality and PTSD symptoms over time and their effects on stress exposure in a sample of 222 trauma-exposed veterans (ages 23-68; 90.5% male). Personality functioning and PTSD were measured approximately 4 years apart, and self-reported exposure to major adverse life events during the interim was also assessed. Negative emotionality positively predicted future PTSD symptoms, and this effect was partially mediated by exposure to new events. Constraint (negatively) indirectly affected PTSD via its association with exposure to new events. There were no significant effects of positive emotionality nor did PTSD symptom severity exert influences on personality over time. Results indicate that high negative affect and disconstraint influence the course of PTSD symptoms by increasing exposure to stressful life events. Published by Elsevier Ltd.

[Systemic coronary surgery in the beating heart. Experience in 250 cases].

PubMed

Cartier, R; Bouchard, D; Martineau, R; Couturier, A

1999-01-01

To report our recent experience with off-pump coronary artery revascularization in multi-vessel disease. Between October 1996 and August 1998, 250 off-pump (OP) procedures were completed at the Montreal Heart Institute, representing more than 90% of all procedures done during the same time frame (97% for 1998). These patients have been compared to 1870 patients operated upon under cardiopulmonary bypass during the years 1995-1996 (CPB). Mean age, sexe distribution, and preoperative risk factors were comparable for both groups. On average 2.89 +/- 0.8 and 2.84 +/- 0.6 grafts/patient were completed in OP and CPB groups respectively. A majority (70%) of patients had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization". Ischemic time was shorter in the OP group (29.8 +/- 0.9 vs 45 +/- 0.4 min, p < 0.05). Similarly, need for transfusion was significantly less (OP: 34 vs CPB: 66%, p < 0.005). Use of postoperative intra-aortic counterpulsation as well as the raise of CK-MB were lesser in the OP group. Operative mortality (OP: 1.6%, vs CPB: 2%, p = ns) and perioperative myocardial infarction rate (OP: 3.6% vs CPB: 4.2) were comparable for both groups. Off-pump complete coronary artery revascularization is an acceptable alternative to conventional surgery in a majority of patients with good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

[Distribution characteristics of dissolved oxygen and its affecting factors in the Pearl River Estuary during the summer of the extremely drought hydrological year 2011].

PubMed

Ye, Feng; Huang, Xiao-ping; Shi, Zhen; Liu, Qing-xi

2013-05-01

More and more attention has focused on assessing impacts of extreme hydrologic events on estuarine ecosystem under the background of climate change. Based on a summer cruise conducted in the Pearl River Estuary in 2011 (extreme drought event), we have investigated the spatial distribution of dissolved oxygen (DO) and its relationships to water column stability, nutrient concentrations, and organic matter; besides, the major reason which caused the oxygen depletion was discussed. Under the influence of the extreme drought event, low bottom water dissolved oxygen was apparent in regions characterized by great depths, with an oxygen minimum value of 1.38 mg x L(-1). Statistical analysis shows significant correlations among deltaDO, deltaT, deltaS and deltaPOC. A comparison was conducted to show the mechanisms of oxygen depletion during the summers of 1999, 2009 and 2011, respectively. The result indicates that prolonged residence time of water due to the extremely low discharge and the subsequently decomposition of organic substance are major factors causing the formation of hypoxia during the summer drought in 2011. Despite the changing nutrient and organic matter regime in the Pearl River Estuary, there was no apparent trend in the minimum values of DO over the past 2 decades.

Longevity of major coenzymes allows minimal de novo synthesis in microorganisms.

PubMed

Hartl, Johannes; Kiefer, Patrick; Meyer, Fabian; Vorholt, Julia A

2017-05-15

Coenzymes are vital for cellular metabolism and act on the full spectrum of enzymatic reactions. Intrinsic chemical reactivity, enzyme promiscuity and high flux through their catalytic cycles make coenzymes prone to damage. To counteract such compromising factors and ensure stable levels of functional coenzymes, cells use a complex interplay between de novo synthesis, salvage, repair and degradation. However, the relative contribution of these factors is currently unknown, as is the overall stability of coenzymes in the cell. Here, we use dynamic 13 C-labelling experiments to determine the half-life of major coenzymes of Escherichia coli. We find that coenzymes such as pyridoxal 5-phosphate, flavins, nicotinamide adenine dinucleotide (phosphate) and coenzyme A are remarkably stable in vivo and allow biosynthesis close to the minimal necessary rate. In consequence, they are essentially produced to compensate for dilution by growth and passed on over generations of cells. Exceptions are antioxidants, which are short-lived, suggesting an inherent requirement for increased renewal. Although the growth-driven turnover of stable coenzymes is apparently subject to highly efficient end-product homeostasis, we exemplify that coenzyme pools are propagated in excess in relation to actual growth requirements. Additional testing of Bacillus subtilis and Saccharomyces cerevisiae suggests that coenzyme longevity is a conserved feature in biology.

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments.

PubMed

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-04-15

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability.

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments

PubMed Central

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-01-01

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability. PMID:27079657

Application of the thermofluor PaSTRy technique for improving foot-and-mouth disease virus vaccine formulation.

PubMed

Kotecha, Abhay; Zhang, Fuquan; Juleff, Nicholas; Jackson, Terry; Perez, Eva; Stuart, Dave; Fry, Elizabeth; Charleston, Bryan; Seago, Julian

2016-07-01

Foot-and-mouth disease (FMD) has a major economic impact throughout the world and is a considerable threat to food security. Current FMD virus (FMDV) vaccines are made from chemically inactivated virus and need to contain intact viral capsids to maximize efficacy. FMDV exists as seven serotypes, each made up by a number of constantly evolving subtypes. A lack of immunological cross-reactivity between serotypes and between some strains within a serotype greatly complicates efforts to control FMD by vaccination. Thus, vaccines for one serotype do not afford protection against the others, and multiple-serotype-specific vaccines are required for effective control. The FMDV serotypes exhibit variation in their thermostability, and the capsids of inactivated preparations of the O, C and SAT serotypes are particularly susceptible to dissociation at elevated temperature. Methods to quantify capsid stability are currently limited, lack sensitivity and cannot accurately reflect differences in thermostability. Thus, new, more sensitive approaches to quantify capsid stability would be of great value for the production of more stable vaccines and to assess the effect of production conditions on vaccine preparations. Here we have investigated the application of a novel methodology (termed PaSTRy) that utilizes an RNA-binding fluorescent dye and a quantitative (q)PCR machine to monitor viral genome release and hence dissociation of the FMDV capsid during a slow incremental increase in temperature. PaSTRy was used to characterize capsid stability of all FMDV serotypes. Furthermore, we have used this approach to identify stabilizing factors for the most labile FMDV serotypes.

Application of the thermofluor PaSTRy technique for improving foot-and-mouth disease virus vaccine formulation

PubMed Central

Kotecha, Abhay; Zhang, Fuquan; Juleff, Nicholas; Jackson, Terry; Perez, Eva; Stuart, Dave; Fry, Elizabeth; Charleston, Bryan

2016-01-01

Foot-and-mouth disease (FMD) has a major economic impact throughout the world and is a considerable threat to food security. Current FMD virus (FMDV) vaccines are made from chemically inactivated virus and need to contain intact viral capsids to maximize efficacy. FMDV exists as seven serotypes, each made up by a number of constantly evolving subtypes. A lack of immunological cross-reactivity between serotypes and between some strains within a serotype greatly complicates efforts to control FMD by vaccination. Thus, vaccines for one serotype do not afford protection against the others, and multiple-serotype-specific vaccines are required for effective control. The FMDV serotypes exhibit variation in their thermostability, and the capsids of inactivated preparations of the O, C and SAT serotypes are particularly susceptible to dissociation at elevated temperature. Methods to quantify capsid stability are currently limited, lack sensitivity and cannot accurately reflect differences in thermostability. Thus, new, more sensitive approaches to quantify capsid stability would be of great value for the production of more stable vaccines and to assess the effect of production conditions on vaccine preparations. Here we have investigated the application of a novel methodology (termed PaSTRy) that utilizes an RNA-binding fluorescent dye and a quantitative (q)PCR machine to monitor viral genome release and hence dissociation of the FMDV capsid during a slow incremental increase in temperature. PaSTRy was used to characterize capsid stability of all FMDV serotypes. Furthermore, we have used this approach to identify stabilizing factors for the most labile FMDV serotypes. PMID:27002540

The Stability of Medicinal Plant microRNAs in the Herb Preparation Process.

PubMed

Xie, Wenyan; Melzig, Matthias F

2018-04-16

Herbal medicine is now globally accepted as a valid alternative system of pharmaceutical therapies. Various studies around the world have been initiated to develop scientific evidence-based herbal therapies. Recently, the therapeutic potential of medicinal plant derived miRNAs has attracted great attraction. MicroRNAs have been indicated as new bioactive ingredients in medicinal plants. However, the stability of miRNAs during the herbal preparation process and their bioavailability in humans remain unclear. Viscum album L. (European mistletoe) has been widely used in folk medicine for the treatment of cancer and cardiovascular diseases. Our previous study has indicated the therapeutic potential of mistletoe miRNAs by using bioinformatics tools. To evaluate the stability of these miRNAs, various mistletoe extracts that mimic the clinical medicinal use as well as traditional folk medicinal use were prepared. The mistletoe miRNAs including miR166a-3p, miR159a, miR831-5p, val-miR218 and val-miR11 were quantified by stem-loop qRT-PCR. As a result, miRNAs were detectable in the majority of the extracts, indicating that consumption of medicinal plant preparations might introduce miRNAs into mammals. The factors that might cause miRNA degradation include ultrasonic treatment, extreme heat, especially RNase treatment, while to be associated with plant molecules (e.g., proteins, exosomes) might be an efficient way to protect miRNAs against degradation. Our study confirmed the stability of plant derived miRNAs during herb preparations, suggesting the possibility of functionally intact medicinal plant miRNAs in mammals.

Stressed Stability Techniques for Adjuvant Formulations.

PubMed

Hasija, Manvi; Sheung, Anthony; Rahman, Nausheen; Ausar, Salvador F

2017-01-01

Stressed stability testing is crucial to the understanding of mechanisms of degradation and the effects of external stress factors on adjuvant stability. These studies vastly help the development of stability indicating tests and the selection of stabilizing conditions for long term storage. In this chapter, we provide detailed protocols for the execution of forced degradation experiments that evaluate the robustness of adjuvant formulations against thermal, mechanical, freeze-thawing, and photo stresses.

Plasmonic fluorescent CdSe/Cu2S hybrid nanocrystals for multichannel imaging and cancer directed photo-thermal therapy

NASA Astrophysics Data System (ADS)

Sheikh Mohamed, M.; Poulose, Aby Cheruvathoor; Veeranarayanan, Srivani; Romero Aburto, Rebecca; Mitcham, Trevor; Suzuki, Yuko; Sakamoto, Yasushi; Ajayan, Pulickel M.; Bouchard, Richard R.; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D.

2016-04-01

A simple, crude Jatropha curcas (JC) oil-based synthesis approach, devoid of any toxic phosphine and pyrophoric ligands, to produce size and shape tuned CdSe QDs and a further copper sulfide (Cu2S) encasing is presented. The QDs exhibited excellent photoluminescent properties with narrow band gap emission. Furthermore, the Cu2S shell rendered additional cytocompatibility and stability to the hybrid nanomaterial, which are major factors for translational and clinical applications of QDs. The nanocomposites were PEGylated and folate conjugated to augment their cytoamiability and enhance their specificity towards cancer cells. The nanohybrids possess potentials for visible, near infrared (NIR), photoacoustic (PA) and computed tomography (μCT) imaging. The diverse functionality of the composite was derived from the multi-channel imaging abilities and thermal competence on NIR laser irradiation to specifically actuate the photo-thermal ablation of brain cancer cells.A simple, crude Jatropha curcas (JC) oil-based synthesis approach, devoid of any toxic phosphine and pyrophoric ligands, to produce size and shape tuned CdSe QDs and a further copper sulfide (Cu2S) encasing is presented. The QDs exhibited excellent photoluminescent properties with narrow band gap emission. Furthermore, the Cu2S shell rendered additional cytocompatibility and stability to the hybrid nanomaterial, which are major factors for translational and clinical applications of QDs. The nanocomposites were PEGylated and folate conjugated to augment their cytoamiability and enhance their specificity towards cancer cells. The nanohybrids possess potentials for visible, near infrared (NIR), photoacoustic (PA) and computed tomography (μCT) imaging. The diverse functionality of the composite was derived from the multi-channel imaging abilities and thermal competence on NIR laser irradiation to specifically actuate the photo-thermal ablation of brain cancer cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05225d

Modeling of the hypothalamic-pituitary-adrenal axis-mediated interaction between the serotonin regulation pathway and the stress response using a Boolean approximation: a novel study of depression

PubMed Central

2013-01-01

Major depressive disorder (MDD) is a multifactorial disorder known to be influenced by both genetic and environmental factors. MDD presents a heritability of 37%, and a genetic contribution has also been observed in studies of family members of individuals with MDD that imply that the probability of suffering the disorder is approximately three times higher if a first-degree family member is affected. Childhood maltreatment and stressful life events (SLEs) have been established as critical environmental factors that profoundly influence the onset of MDD. The serotonin pathway has been a strong candidate for genetic studies, but it only explains a small proportion of the heritability of the disorder, which implies the involvement of other pathways. The serotonin (5-HT) pathway interacts with the stress response pathway in a manner mediated by the hypothalamic-pituitary-adrenal (HPA) axis. To analyze the interaction between the pathways, we propose the use of a synchronous Boolean network (SBN) approximation. The principal aim of this work was to model the interaction between these pathways, taking into consideration the presence of selective serotonin reuptake inhibitors (SSRIs), in order to observe how the pathways interact and to examine if the system is stable. Additionally, we wanted to study which genes or metabolites have the greatest impact on model stability when knocked out in silico. We observed that the biological model generated predicts steady states (attractors) for each of the different runs performed, thereby proving that the system is stable. These attractors changed in shape, especially when anti-depressive drugs were also included in the simulation. This work also predicted that the genes with the greatest impact on model stability were those involved in the neurotrophin pathway, such as CREB, BDNF (which has been associated with major depressive disorder in a variety of studies) and TRkB, followed by genes and metabolites related to 5-HT synthesis. PMID:24093582

Overeating and Binge Eating in Emerging Adulthood: 10-Year Stability and Risk Factors

ERIC Educational Resources Information Center

Goldschmidt, Andrea B.; Wall, Melanie M.; Zhang, Jun; Loth, Katie A.; Neumark-Sztainer, Dianne

2016-01-01

Overeating (eating an unusually large amount of food) and binge eating (overeating with loss of control [LOC]) predict adverse health consequences in adolescence. We aimed to characterize the stability of and risk factors for these distinct but interrelated constructs during critical developmental transitions. We used a population-based sample (n…

Can plant-natural enemy communication withstand disruption by biotic and abiotic factors?

PubMed

Clavijo McCormick, Andrea

2016-12-01

The attraction of natural enemies towards herbivore-induced plant volatiles is a well-documented phenomenon. However, the majority of published studies are carried under optimal water and nutrient regimes and with just one herbivore. But what happens when additional levels of ecological complexity are added? Does the presence of a second herbivore, microorganisms, and abiotic stress interfere with plant-natural enemy communication? or is communication stable enough to withstand disruption by additional biotic and abiotic factors?Investigating the effects of these additional levels of ecological complexity is key to understanding the stability of tritrophic interactions in natural ecosystems and may aid to forecast the impact of environmental disturbances on these, especially in climate change scenarios, which are often associated with modifications in plant and arthropod species distribution and increased levels of abiotic stress.This review explores the literature on natural enemy attraction to herbivore-induced volatiles when, besides herbivory, plants are challenged by additional biotic and abiotic factors.The aim of this review was to establish the impact of different biotic and abiotic factors on plant-natural enemy communication and to highlight critical aspects to guide future research efforts.

Hydrogeologic factors in the selection of shallow land burial sites for the disposal of low-level radioactive waste

USGS Publications Warehouse

Fischer, John N.

1986-01-01

In the United States, low-level radioactive waste is disposed of by shallow land burial. Commercial low-level radioactive waste has been buried at six sites, and low-level radioactive waste generated by the Federal Government has been buried at nine major and several minor sites. Several existing low-level radioactive waste sites have not provided expected protection of the environment. These shortcomings are related, at least in part, to an inadequate understanding of site hydrogeology at the time the sites were selected. To better understand the natural systems and the effect of hydrogeologic factors on long-term site performance, the U.S. Geological Survey has conducted investigations at five of the six commercial low-level radioactive waste sites and at three Federal sites. These studies, combined with those of other Federal and State agencies, have identified and confirmed important hydrogeologic factors in the effective disposal of low-level radioactive waste by shallow land burial. These factors include precipitation, surface drainage, topography, site stability, geology, thickness of the host soil-rock horizon, soil and sediment permeability, soil and water chemistry, and depth to the water table.

Dynamical diagnostics of the SST annual cycle in the eastern equatorial Pacific: part I a linear coupled framework

NASA Astrophysics Data System (ADS)

Chen, Ying-Ying; Jin, Fei-Fei

2018-03-01

The eastern equatorial Pacific has a pronounced westward propagating SST annual cycle resulting from ocean-atmosphere interactions with equatorial semiannual solar forcing and off-equatorial annual solar forcing conveyed to the equator. In this two-part paper, a simple linear coupled framework is proposed to quantify the internal dynamics and external forcing for a better understanding of the linear part of the dynamics annual cycle. It is shown that an essential internal dynamical factor is the SST damping rate which measures the coupled stability in a similar way as the Bjerknes instability index for the El Niño-Southern Oscillation. It comprises three major negative terms (dynamic damping due to the Ekman pumping feedback, mean circulation advection, and thermodynamic feedback) and two positive terms (thermocline feedback and zonal advection). Another dynamical factor is the westward-propagation speed that is mainly determined by the thermodynamic feedback, the Ekman pumping feedback, and the mean circulation. The external forcing is measured by the annual and semiannual forcing factors. These linear internal and external factors, which can be estimated from data, determine the amplitude of the annual cycle.

Telomeres, Nutrition, and Longevity: Can We Really Navigate Our Aging?

PubMed

Vidacek, Nikolina Škrobot; Nanic, Lucia; Ravlic, Sanda; Sopta, Mary; Geric, Marko; Gajski, Goran; Garaj-Vrhovac, Vera; Rubelj, Ivica

2017-12-12

Telomeres are dynamic chromosome-end structures that serve as guardians of genome stability. They are known to be one of the major determinants of aging and longevity in higher mammals. Studies have demonstrated a direct correlation between telomere length and life expectancy, stress, DNA damage, and onset of aging-related diseases. This review discusses the most important factors that influence our telomeres. Various genetic and environmental factors such as diet, physical activity, obesity, and stress are known to influence health and longevity as well as telomere dynamics. Individuals currently have the opportunity to modulate the dynamics of their aging and health span, monitor these processes, and even make future projections by following their telomere dynamics. As telomeres react to positive as well as negative health factors, we should be able to directly influence our telomere metabolism, slow their deterioration, and diminish our aging and perhaps extend our life and health span. © The Author(s) 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Related Studies in Long Term Lithium Battery Stability

NASA Technical Reports Server (NTRS)

Horning, R. J.; Chua, D. L.

1984-01-01

The continuing growth of the use of lithium electrochemical systems in a wide variety of both military and industrial applications is primarily a result of the significant benefits associated with the technology such as high energy density, wide temperature operation and long term stability. The stability or long term storage capability of a battery is a function of several factors, each important to the overall storage life and, therefore, each potentially a problem area if not addressed during the design, development and evaluation phases of the product cycle. Design (e.g., reserve vs active), inherent material thermal stability, material compatibility and self-discharge characteristics are examples of factors key to the storability of a power source.

The gut microbiota and the emergence of autoimmunity: relevance to major psychiatric disorders

PubMed Central

Severance, EG; Tveiten, D; Lindström, LH; Yolken, RH; Reichelt, KL

2017-01-01

Background Autoimmune phenotypes are prevalent in major psychiatric disorders. Disequilibria of cellular processes occurring in the gastrointestinal (GI) tract likely contribute to immune dysfunction in psychiatric disorders. As the venue of a complex community of resident microbes, the gut in a homeostatic state equates with a functional digestive system, cellular barrier stability and properly regulated recognition of self and non-self antigens. When gut processes become disrupted as a result of environmental or genetic factors, autoimmunity may ensue. Methods Here, we review the issues pertinent to autoimmunity and the microbiome in psychiatric disorders and show that many of the reported immune risk factors for the development of these brain disorders are in fact related and consistent with dysfunctions occurring in the gut. We review the few human microbiome studies that have been done in people with psychiatric disorders and supplement this information with mechanistic data gleaned from experimental rodent studies. Results These investigations demonstrate changes in behavior and brain biochemistry directly attributable to alterations in the gut microbiome. We present a model by which autoantigens are produced by extrinsically-derived food and microbial factors bound to intrinsic components of the gut including receptors present in the enteric nervous system. Conclusion This new focus on examining activities outside of the CNS for relevance to the etiology and pathophysiology of psychiatric disorders may require new modalities or a re-evaluation of pharmaceutical targets found in peripheral systems. PMID:27634185

Vitamin D cell signalling in health and disease.

PubMed

Berridge, Michael J

2015-04-24

Vitamin D deficiency has been linked to many human diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), hypertension and cardiovascular disease. A Vitamin D phenotypic stability hypothesis, which is developed in this review, attempts to describe how this vital hormone acts to maintain healthy cellular functions. This role of Vitamin D as a guardian of phenotypic stability seems to depend on its ability to maintain the redox and Ca(2+) signalling systems. It is argued that its primary action is to maintain the expression of those signalling components responsible for stabilizing the low resting state of these two signalling pathways. This phenotypic stability role is facilitated through the ability of vitamin D to increase the expression of both Nrf2 and the anti-ageing protein Klotho, which are also major regulators of Ca(2+) and redox signalling. A decline in Vitamin D levels will lead to a decline in the stability of this regulatory signalling network and may account for why so many of the major diseases in man, which have been linked to vitamin D deficiency, are associated with a dysregulation in both ROS and Ca(2+) signalling. Copyright © 2015 Elsevier Inc. All rights reserved.

On the stability analysis of approximate factorization methods for 3D Euler and Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Demuren, A. O.; Ibraheem, S. O.

1993-01-01

The convergence characteristics of various approximate factorizations for the 3D Euler and Navier-Stokes equations are examined using the von-Neumann stability analysis method. Three upwind-difference based factorizations and several central-difference based factorizations are considered for the Euler equations. In the upwind factorizations both the flux-vector splitting methods of Steger and Warming and van Leer are considered. Analysis of the Navier-Stokes equations is performed only on the Beam and Warming central-difference scheme. The range of CFL numbers over which each factorization is stable is presented for one-, two-, and three-dimensional flow. Also presented for each factorization is the CFL number at which the maximum eigenvalue is minimized, for all Fourier components, as well as for the high frequency range only. The latter is useful for predicting the effectiveness of multigrid procedures with these schemes as smoothers. Further, local mode analysis is performed to test the suitability of using a uniform flow field in the stability analysis. Some inconsistencies in the results from previous analyses are resolved.

[Factor XIII-guided treatment algorithm reduces blood transfusion in burn surgery].

PubMed

Carneiro, João Miguel Gonçalves Valadares de Morais; Alves, Joana; Conde, Patrícia; Xambre, Fátima; Almeida, Emanuel; Marques, Céline; Luís, Mariana; Godinho, Ana Maria Mano Garção; Fernandez-Llimos, Fernando

Major burn surgery causes large hemorrhage and coagulation dysfunction. Treatment algorithms guided by ROTEM ® and factor VIIa reduce the need for blood products, but there is no evidence regarding factor XIII. Factor XIII deficiency changes clot stability and decreases wound healing. This study evaluates the efficacy and safety of factor XIII correction and its repercussion on transfusion requirements in burn surgery. Randomized retrospective study with 40 patients undergoing surgery at the Burn Unit, allocated into Group A those with factor XIII assessment (n = 20), and Group B, those without assessment (n = 20). Erythrocyte transfusion was guided by a hemoglobin trigger of 10g.dL -1 and the other blood products by routine coagulation and ROTEM ® tests. Analysis of blood product consumption included units of erythrocytes, fresh frozen plasma, platelets, and fibrinogen. The coagulation biomarker analysis compared the pre- and post-operative values. Group A (with factor XIII study) and Group B had identical total body surface area burned. All patients in Group A had a preoperative factor XIII deficiency, whose correction significantly reduced units of erythrocyte concentrate transfusion (1.95 vs. 4.05, p = 0.001). Pre- and post-operative coagulation biomarkers were similar between groups, revealing that routine coagulation tests did not identify factor XIII deficiency. There were no recorded thromboembolic events. Correction of factor XIII deficiency in burn surgery proved to be safe and effective for reducing perioperative transfusion of erythrocyte units. Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Insufficiently studied factors related to burnout in nursing: Results from an e-Delphi study

PubMed Central

2017-01-01

Objective This study aimed to identify potentially important factors in explaining burnout in nursing that have been insufficiently studied or ignored. Methods A three-round Delphi study via e-mail correspondence was conducted, with a group of 40 European experts. The e-Delphi questionnaire consisted of 52 factors identified from a literature review. Experts rated and scored the importance of factors in the occurrence of burnout and the degree of attention given by researchers to each of the variables listed, on a six-point Likert scale. We used the agreement percentage (>80%) to measure the level of consensus between experts. Furthermore, to confirm the level of consensus, we also calculated mean scores and modes. Regardless of the degree of consensus reached by the experts, we have calculated the mean of the stability of the answers for each expert (individual's qualitative stability) and the mean of the stability percentages of the experts (qualitative group stability). Results The response rate in the three rounds was 93.02% (n = 40). Eight new factors were suggested in the first round. After modified, the e-Delphi questionnaire in the second and third rounds had 60 factors. All the factors reached the third round with a consensus level above 80% in terms of the attention that researchers gave them in their studies. Moreover, the data show a total mean qualitative group stability of 96.21%. In the third round 9 factors were classified by experts as ‘studied very little’, 17 as ‘studied little’ and 34 as 'well studied' Conclusion Findings show that not all the factors that may influence nursing burnout have received the same attention from researchers. The panel of experts has identified factors that, although important in explaining burnout, have been poorly studied or even forgotten. Our results suggest that further study into factors such as a lack of recognition of part of the tasks that nurses perform, feminine stereotype or excessive bureaucracy is needed for a better understanding of this syndrome and improve the quality of life in nurses. PMID:28388660

Contribution of Hydrophobic Interactions to Protein Stability

PubMed Central

Pace, C. Nick; Fu, Hailong; Fryar, Katrina Lee; Landua, John; Trevino, Saul R.; Shirley, Bret A.; Hendricks, Marsha McNutt; Iimura, Satoshi; Gajiwala, Ketan; Scholtz, J. Martin; Grimsley, Gerald R.

2011-01-01

Our goal was to gain a better understanding of the contribution of hydrophobic interactions to protein stability. We measured the change in conformational stability, Δ(ΔG), for hydrophobic mutants of four proteins: villin head piece subdomain (VHP) with 36 residues, a surface protein from Borrelia burgdorferi (VlsE) with 341 residues, and two proteins previously studied in our laboratory, ribonucleases Sa and T1. We compare our results with previous studies and reach the following conclusions. 1. Hydrophobic interactions contribute less to the stability of a small protein, VHP (0.6 ± 0.3 kcal/mole per –CH2– group), than to the stability of a large protein, VlsE (1.6 ± 0.3 kcal/mol per –CH2– group). 2. Hydrophobic interactions make the major contribution to the stability of VHP (40 kcal/mol) and the major contributors are (in kcal/mol): Phe 18 (3.9), Met 13 (3.1), Phe 7 (2.9), Phe 11 (2.7), and Leu 21 (2.7). 3. Based on Δ(ΔG) values for 148 hydrophobic mutants in 13 proteins, burying a –CH2– group on folding contributes, on average, 1.1 ± 0.5 kcal/mol to protein stability. 4. The experimental Δ(ΔG) values for aliphatic side chains (Ala, Val, Ile, and Leu) are in good agreement with their ΔGtr values from water to cyclohexane. 5. For 22 proteins with 36 to 534 residues, hydrophobic interactions contribute 60 ± 4% and hydrogen bonds 40 ± 4% to protein stability. 6. Conformational entropy contributes about 2.4 kcal/mol per residue to protein instability. The globular conformation of proteins is stabilized predominately by hydrophobic interactions. PMID:21377472

[Stability of home based care arrangements for people with dementia : Development of a consensus definition of stability using expert focus groups].

PubMed

von Kutzleben, Milena; Köhler, Kerstin; Dreyer, Jan; Holle, Bernhard; Roes, Martina

2017-04-01

The majority of people with dementia in Germany live at home. These informal care arrangements, which are mostly coordinated by informal carers, are the backbone of home-based dementia care. Creating and maintaining stability is an underlying theme in informal care; however, a definition of the complex phenomenon of 'stability' in this context is still lacking. The aim was to develop a working definition of stability of home-based care arrangements for people with dementia, which can be applied in current and future research projects at the German Center for Neurodegenerative Diseases in Witten (DZNE Witten) and others. Ensuing from prior research a preliminary version of the definition was formulated. This definition was discussed in a focus group of scientific experts with expertise in dementia research and care (n = 8). After data analysis using content analysis, the definition was revised during a scientific colloquium (n = 18) and a consensus was finally reached. There were four major themes which were considered by the experts as being relevant for the definition of stability: (1) creating and maintaining stability as a continuous adaptation process, (2) a qualitative component of stability, (3) persons with dementia and informal carers as pivotal players and (4) transitions to residential care. The working definition introduced in this article reflects the authors' understanding of the phenomenon of stability of home-based care arrangements for people with dementia. In times of increasing need for evidence-based interventions it is necessary to develop elaborated definitions of complex phenomena in order to be able to systematically evaluate the efficacy of interventions on the basis of a common understanding.

Quantification of Urban Environment's Role in Slope Stability for Landslide Events.

NASA Astrophysics Data System (ADS)

Bozzolan, E.; Holcombe, E.; Wagener, T.; Pianosi, F.

2017-12-01

The combination of a rapid and unplanned urban development with a likely future climate change could significantly affect landslide occurrences in the humid tropics, where rainfall events of high intensity and duration are the dominant trigger for landslide risk. The attention of current landslide hazard studies is largely focussed on natural slope processes based on combinations of environmental factors, excluding the role of urbanisation on slope stability. This project aims to understand the relative influence of urbanisation features on local slope stability and to translate the findings to a wider region. Individual slopes are firstly analysed with the software CHASM, a physically based model which combines soil hydrology and slope stability assessment. Instead of relying on existing records, generally lacking for landslides, ranges of plausible preparatory (such as slope, cohesion, friction angles), triggering (rainfall) and aggravating factors (deforestation, house density and water network) are defined and possible combinations of these factors are created by sampling from those ranges. The influence of urban features on site hydrology and stability mechanisms are evaluated and then implemented in denser urban contexts, characteristic of unplanned settlements. The results of CHASMS can be transferred to regional maps in order to identify the areas belonging to the triggering combinations of factors previously found. In this way, areas susceptible to landslides can be detected not only in terms of natural factors but also in relation to the degree of urbanisation. Realistic scenarios can be extrapolated from the areas considered and then analysed again with CHASM. This permits to adapt (and improve) the initial variability ranges of the factors, creating a general-specific cycle able to identify the landslide susceptibility regions and outline a hazard map. Once the triggers are understood, possible consequences can be assessed and mitigation strategies can be evaluated. The ability to define local urban rainfall threshold for landslide slope stability helps the decision-making process to prioritize the areas of interest and locally define the main causes of instability.

47 CFR 76.1002 - Specific unfair practices prohibited.

Code of Federal Regulations, 2010 CFR

2010-10-01

... reasonable requirements for creditworthiness, offering of service, and financial stability and standards... classes of service in pricing based on credit considerations or financial stability, although any such... technology. Vendors are not permitted to manifest factors such as creditworthiness or financial stability in...

Soil Water Holding Capacity Mitigates Downside Risk and Volatility in US Rainfed Maize: Time to Invest in Soil Organic Matter?

PubMed Central

Williams, Alwyn; Hunter, Mitchell C.; Kammerer, Melanie; Kane, Daniel A.; Jordan, Nicholas R.; Mortensen, David A.; Smith, Richard G.; Snapp, Sieglinde

2016-01-01

Yield stability is fundamental to global food security in the face of climate change, and better strategies are needed for buffering crop yields against increased weather variability. Regional- scale analyses of yield stability can support robust inferences about buffering strategies for widely-grown staple crops, but have not been accomplished. We present a novel analytical approach, synthesizing 2000–2014 data on weather and soil factors to quantify their impact on county-level maize yield stability in four US states that vary widely in these factors (Illinois, Michigan, Minnesota and Pennsylvania). Yield stability is quantified as both ‘downside risk’ (minimum yield potential, MYP) and ‘volatility’ (temporal yield variability). We show that excessive heat and drought decreased mean yields and yield stability, while higher precipitation increased stability. Soil water holding capacity strongly affected yield volatility in all four states, either directly (Minnesota and Pennsylvania) or indirectly, via its effects on MYP (Illinois and Michigan). We infer that factors contributing to soil water holding capacity can help buffer maize yields against variable weather. Given that soil water holding capacity responds (within limits) to agronomic management, our analysis highlights broadly relevant management strategies for buffering crop yields against climate variability, and informs region-specific strategies. PMID:27560666

Stability of colloidal gold and determination of the Hamaker constant

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

Demirci, S.; Enuestuen, B.V.; Turkevich, J.

1978-12-14

Previous computation of stability factors of colloidal gold from coagulation data was found to be in systematic error due to an underestimation of the particle concentration by electron microscopy. A new experimental technique was developed for determination of this concentration. Stability factors were recalculated from the previous data using the correct concentration. While most of the previously reported conclusions remain unchanged, the absolute rate of fast coagulation is found to agree with that predicted by the theory. A value of the Hamaker constant was determined from the corrected data.

Propitious Therapeutic Modulators to Prevent Blood-Spinal Cord Barrier Disruption in Spinal Cord Injury.

PubMed

Kumar, Hemant; Ropper, Alexander E; Lee, Soo-Hong; Han, Inbo

2017-07-01

The blood-spinal cord barrier (BSCB) is a specialized protective barrier that regulates the movement of molecules between blood vessels and the spinal cord parenchyma. Analogous to the blood-brain barrier (BBB), the BSCB plays a crucial role in maintaining the homeostasis and internal environmental stability of the central nervous system (CNS). After spinal cord injury (SCI), BSCB disruption leads to inflammatory cell invasion such as neutrophils and macrophages, contributing to permanent neurological disability. In this review, we focus on the major proteins mediating the BSCB disruption or BSCB repair after SCI. This review is composed of three parts. Section 1. SCI and the BSCB of the review describes critical events involved in the pathophysiology of SCI and their correlation with BSCB integrity/disruption. Section 2. Major proteins involved in BSCB disruption in SCI focuses on the actions of matrix metalloproteinases (MMPs), tumor necrosis factor alpha (TNF-α), heme oxygenase-1 (HO-1), angiopoietins (Angs), bradykinin, nitric oxide (NO), and endothelins (ETs) in BSCB disruption and repair. Section 3. Therapeutic approaches discusses the major therapeutic compounds utilized to date for the prevention of BSCB disruption in animal model of SCI through modulation of several proteins.

Design of a 3T preamplifier which stability is insensitive to coil loading

NASA Astrophysics Data System (ADS)

Cao, Xueming; Fischer, Elmar; Korvink, Jan G.; Gruschke, Oliver; Hennig, Jürgen; Zaitsev, Maxim

2016-04-01

In MRI (magnetic resonance imaging), preamplifiers are needed to amplify signals obtained from MRI receiver coils. Under various loading conditions of the corresponding receiver coils, preamplifiers see different source impedance at their input and may become unstable. Therefore preamplifiers which stability is not sensitive to coil loading are desirable. In this article, a coil-loading-insensitive preamplifier for MRI is presented, derived from an unstable preamplifier. Different approaches to improve stability were used during this derivation. Since a very low noise factor is essential for MRI preamplifiers, noise contributions from passive components in the MRI preamplifier have to be considered during the stabilization process. As a result, the initially unstable preamplifier became stable with regard to coil loading, while other MRI requirements, as the extremely low noise factor, were still fulfilled. The newly designed preamplifier was manufactured, characterized and tested in the MRI spectrometer. Compared to a commercially available preamplifier, the newly designed preamplifier has similar imaging performance but other advantages like smaller size and better stability. Furthermore, presented stabilization approaches can be generalized to stabilize other unstable low-noise amplifiers.

Military Cooperation, Political Stability, CENTCOM: The Saudi Conundrum.

DTIC Science & Technology

Ras Banas were unobtainable. Therefore, appropriations for military construction have not been available. The political stability requirements of the...adopt policies which might undermine its political stability are an important factor contributing to this ambivalence. The advantages of specific...contingency arrangements must be weighed against other U.S. objectives. particularly domestic political stability . The history of the U.S. -Saudi bilateral

The ring residue proline 8 is crucial for the thermal stability of the lasso peptide caulosegnin II.

PubMed

Hegemann, Julian D; Fage, Christopher D; Zhu, Shaozhou; Harms, Klaus; Di Leva, Francesco Saverio; Novellino, Ettore; Marinelli, Luciana; Marahiel, Mohamed A

2016-04-01

Lasso peptides are fascinating natural products with a unique structural fold that can exhibit tremendous thermal stability. Here, we investigate factors responsible for the thermal stability of caulosegnin II. By employing X-ray crystallography, mutational analysis and molecular dynamics simulations, the ring residue proline 8 was proven to be crucial for thermal stability.

3D cell printing of in vitro stabilized skin model and in vivo pre-vascularized skin patch using tissue-specific extracellular matrix bioink: A step towards advanced skin tissue engineering.

PubMed

Kim, Byoung Soo; Kwon, Yang Woo; Kong, Jeong-Sik; Park, Gyu Tae; Gao, Ge; Han, Wonil; Kim, Moon-Bum; Lee, Hyungseok; Kim, Jae Ho; Cho, Dong-Woo

2018-06-01

3D cell-printing technique has been under spotlight as an appealing biofabrication platform due to its ability to precisely pattern living cells in pre-defined spatial locations. In skin tissue engineering, a major remaining challenge is to seek for a suitable source of bioink capable of supporting and stimulating printed cells for tissue development. However, current bioinks for skin printing rely on homogeneous biomaterials, which has several shortcomings such as insufficient mechanical properties and recapitulation of microenvironment. In this study, we investigated the capability of skin-derived extracellular matrix (S-dECM) bioink for 3D cell printing-based skin tissue engineering. S-dECM was for the first time formulated as a printable material and retained the major ECM compositions of skin as well as favorable growth factors and cytokines. This bioink was used to print a full thickness 3D human skin model. The matured 3D cell-printed skin tissue using S-dECM bioink was stabilized with minimal shrinkage, whereas the collagen-based skin tissue was significantly contracted during in vitro tissue culture. This physical stabilization and the tissue-specific microenvironment from our bioink improved epidermal organization, dermal ECM secretion, and barrier function. We further used this bioink to print 3D pre-vascularized skin patch able to promote in vivo wound healing. In vivo results revealed that endothelial progenitor cells (EPCs)-laden 3D-printed skin patch together with adipose-derived stem cells (ASCs) accelerates wound closure, re-epithelization, and neovascularization as well as blood flow. We envision that the results of this paper can provide an insightful step towards the next generation source for bioink manufacturing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Leveraging Venture Capital and Commercial Business: Enhancing Stability Operations

DTIC Science & Technology

2011-03-24

Economic Stability Operations have emerged as a new element of United States national strategic power. The creation of jobs, through commercial...examine the key strategic factors influencing long-term economic stability following the withdrawal of combat forces. This paper provides a model for

The Structural and Rank-Order Stability of Temperament in Young Children Based on a Laboratory-Observational Measure

PubMed Central

Dyson, Margaret W.; Olino, Thomas M.; Durbin, C. Emily; Goldsmith, H. Hill; Bufferd, Sara J.; Miller, Anna R.; Klein, Daniel N.

2015-01-01

It is generally assumed that temperament traits exhibit structural and rank-order stability over time. Most of the research on structural and rank-order stability has relied on parent-report measures. The present study used an alternative approach, a laboratory-observational measure (Laboratory Temperament Assessment Battery [Lab-TAB]), to examine the structural and rank-order stability of temperament traits in a community sample of young children (N = 447). Using structural equation modeling (SEM), we found that a similar five-factor structure consisting of the dimensions of Positive Affect/Interest, Sociability, Dysphoria, Fear/Inhibition, and Impulsivity vs. Constraint provided an adequate fit to the data at both age 3 and 6 years, suggesting good structural stability. Moreover, all five latent factors exhibited significant, albeit modest, rank-order stability from age 3 to 6. In addition, there were significant heterotypic associations of age 3 Sociability with age 6 PA/Interest, and age 3 Impulsivity vs. Constraint with age 6 Fear/Inhibition. PMID:25894709

Explaining IT Professionals' Organizational Commitment Based on Age, Gender, and Personality Trait Factor

ERIC Educational Resources Information Center

Syed, Javaid A.

2017-01-01

The purpose of the present study was to test the Emotional Stability dimension of the Big Five factors of personality traits theory to predict or explain a relationship with Employee Organizational Commitment, when the relationship between Emotional Stability (ES) and Employee Organizational Commitment (EOC) was moderated by Gender and AgeGroup.…

The Stability of Post Hoc Model Modifications in Covariance Structure Models.

ERIC Educational Resources Information Center

Hutchinson, Susan R.

The work of R. MacCallum et al. (1992) was extended by examining chance modifications through a Monte Carlo simulation. The stability of post hoc model modifications was examined under varying sample size, model complexity, and severity of misspecification using 2- and 4-factor oblique confirmatory factor analysis (CFA) models with four and eight…

Stability and change in personality assessment: the revised NEO Personality Inventory in the year 2000.

PubMed

Costa, P T; McCrae, R R

1997-02-01

The Revised NEO Personality Inventory (NEO-PI-R) consists of 30 facet scales that define the broad domains of the Five-Factor Model of personality. No major revisions of the basic model are anticipated in the near future. Despite their popularity, social desirability and inconsistency scales will not be added to the NEO-PI-R because their validity and utility have not yet been demonstrated. Among possible changes are minor modifications in wording and more extensive adaptations for adolescents and for populations with low reading levels. Contextualized (e.g., work-related) versions of the instrument will be further explored. Many changes are more easily implemented on the computer than the print version of the instrument.

The Work Preference Inventory: assessing intrinsic and extrinsic motivational orientations.

PubMed

Amabile, T M; Hill, K G; Hennessey, B A; Tighe, E M

1994-05-01

The Work Preference Inventory (WPI) is designed to assess individual differences in intrinsic and extrinsic motivational orientations. Both the college student and the working adult versions aim to capture the major elements of intrinsic motivation (self-determination, competence, task involvement, curiosity, enjoyment, and interest) and extrinsic motivation (concerns with competition, evaluation, recognition, money or other tangible incentives, and constraint by others). The instrument is scored on two primary scales, each subdivided into 2 secondary scales. The WPI has meaningful factor structures, adequate internal consistency, good short-term test-retest reliability, and good longer term stability. Moreover, WPI scores are related in meaningful ways to other questionnaire and behavioral measures of motivation, as well as personality characteristics, attitudes, and behaviors.

Synthesis and biology of cyclic imine toxins, an emerging class of potent, globally distributed marine toxins.

PubMed

Stivala, Craig E; Benoit, Evelyne; Aráoz, Rómulo; Servent, Denis; Novikov, Alexei; Molgó, Jordi; Zakarian, Armen

2015-03-01

From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulation in shellfish, and chemical stability are important considerations in assessing risk factors for human health. This review article aims to provide an account of chemistry, biology, and toxicology of CI toxins from their discovery to the present day.

Patterns of sleep behaviour.

NASA Technical Reports Server (NTRS)

Webb, W. B.

1972-01-01

Discussion of the electroencephalogram as the critical measurement procedure for sleep research, and survey of major findings that have emerged in the last decade on the presence of sleep within the twenty-four-hour cycle. Specifically, intrasleep processes, frequency of stage changes, sequence of stage events, sleep stage amounts, temporal patterns of sleep, and stability of intrasleep pattern in both man and lower animals are reviewed, along with some circadian aspects of sleep, temporal factors, and number of sleep episodes. It is felt that it is particularly critical to take the presence of sleep into account whenever performance is considered. When it is recognized that responsive performance is extremely limited during sleep, it is easy to visualize the extent to which performance is controlled by sleep itself.

Usual Dose of Caffeine Has a Positive Effect on Somatosensory Related Postural Stability in Hemiparetic Stroke Patients

PubMed Central

Kim, Woo Sub; Choi, Chang Kweon; Yoon, Sang Ho

2014-01-01

Objective To evaluate the effect of caffeine on balance control of hemiparetic stroke patients, we investigated the difference in postural stability before and after drinking coffee by observing changes in stability index (SI) from posturography. Methods Thirty patients with history of stroke and 15 age-matched healthy subjects participated in this study. Effect of group factor (of the control and stroke groups) and treatment factor (pre- and post-drinking of coffee) on SI were tested in three conditions: with eyes opened, with eyes closed, and with a pillow support. The effects of these factors on visual deprivation and somatosensory change of subjects were also tested. Results Under all conditions, SI was higher in the stroke group than in the control group. Under eyes-open condition, the treatment factor was not statistically significant. Under eyes-closed condition, the interaction between group and treatment factor was statistically significant. After the subjects drank coffee, SI in the control group was increased. However, SI in the stroke group was decreased. Under pillow-supported condition, the interaction between group and treatment factor appeared marginally significant. For visual deprivation effect, the interaction between treatment and group factor was statistically significant. After caffeine consumption, the visual deprivation effect was increased in control group but decreased in the stroke group. For somatosensory change effect, the interaction between group and treatment factor was not statistically significant. Conclusion Postural stability of hemiparetic stroke patients related to somatosensory information was improved after intake of usual dose of caffeine. PMID:25566476

A nomogram for interpreting slope stability of fine-grained deposits in modern and ancient-marine environments.

USGS Publications Warehouse

Booth, J.S.; Sangrey, D.A.; Fugate, J.K.

1985-01-01

This nomogram was designed to aid in interpreting the causes of mass movement in modern and ancient settings, to provide a basis for evaluating and predicting slope stability under given conditions and to further the understanding of the relationships among the several key factors that control slope stability. Design of the nomogram is based on effective stress and combines consolidation theory as applicable to depositional environments with the infinite-slope model of slope-stability analysis. If infinite-slope conditions are assumed to exist, the effective overburden stress can be used to derive a factor of safety against static slope failure by using the angle of internal friction and the slope angle. -from Authors

Computer-aided molecular modeling techniques for predicting the stability of drug cyclodextrin inclusion complexes in aqueous solutions

NASA Astrophysics Data System (ADS)

Faucci, Maria Teresa; Melani, Fabrizio; Mura, Paola

2002-06-01

Molecular modeling was used to investigate factors influencing complex formation between cyclodextrins and guest molecules and predict their stability through a theoretical model based on the search for a correlation between experimental stability constants ( Ks) and some theoretical parameters describing complexation (docking energy, host-guest contact surfaces, intermolecular interaction fields) calculated from complex structures at a minimum conformational energy, obtained through stochastic methods based on molecular dynamic simulations. Naproxen, ibuprofen, ketoprofen and ibuproxam were used as model drug molecules. Multiple Regression Analysis allowed identification of the significant factors for the complex stability. A mathematical model ( r=0.897) related log Ks with complex docking energy and lipophilic molecular fields of cyclodextrin and drug.

The European Health and Behaviour Survey: rationale, methods and initial results from the United Kingdom.

PubMed

Wardle, J; Steptoe, A

1991-01-01

The aim of this study was to assess a wide range of health-related behaviours, beliefs concerning the importance of behaviours for health, and health knowledge, using a standardized protocol suitable for translation and administration in different countries of Europe. An inventory was developed from previous literature for the assessment of substance use, positive health practices, diet and eating habits, driving behaviour and preventive health care, beliefs concerning the importance of 25 activities for health, and knowledge about the influence of seven factors (including smoking, alcohol and diet) on major diseases. The first phase of the study involved administration of the inventory to approximately 200 male and 200 female university students aged 18-30 in 20 European countries. This report concerns data collected from 419 students in the U.K., together with analyses of short-term response stability. The inventory showed adequate short-term stability. Sex differences were observed in a number of behaviours, including consumption of fats and cholesterol, salt and fibre, dieting, exercise, sun-protection, driving speed, regular dental check-ups, frequency of brushing teeth, access to doctor and blood pressure measurement. Beliefs about the importance of behaviours for health were closely associated with the occurrence or frequency of the behaviours both within and between health behaviour categories. Little relationship was observed between health behaviour and awareness of the role of these same factors in disease. Important gaps in health knowledge were identified. Data concerning the frequency of health-related behaviours is crucial to the planning of health education and primary prevention programmes. The close association between beliefs and behaviour emphasises the importance of cognitive factors, while health knowledge appears to play a less direct role.

Stability of Chitosan—A Challenge for Pharmaceutical and Biomedical Applications

PubMed Central

Szymańska, Emilia; Winnicka, Katarzyna

2015-01-01

Chitosan—one of the natural multifunctional polymers—due to its unique and versatile biological properties is regarded as a useful compound in medical and pharmaceutical technology. Recently, considerable research effort has been made in order to develop safe and efficient chitosan products. However, the problem of poor stability of chitosan-based systems restricts its practical applicability; thus, it has become a great challenge to establish sufficient shelf-life for chitosan formulations. Improved stability can be assessed by controlling the environmental factors, manipulating processing conditions (e.g., temperature), introducing a proper stabilizing compound, developing chitosan blends with another polymer, or modifying the chitosan structure using chemical or ionic agents. This review covers the influence of internal, environmental, and processing factors on the long-term stability of chitosan products. The aim of this paper is also to highlight the latest developments which enable the physicochemical properties of chitosan-based applications to be preserved upon storage. PMID:25837983

Longitudinal studies of anger and attention span: context and informant effects.

PubMed

Kim, Jungmeen; Mullineaux, Paula Y; Allen, Ben; Deater-Deckard, Kirby

2010-04-01

This study examined stabilities of informant and context (home vs. classroom) latent factors regarding anger and attention. Participants included children from the National Institute of Child Health and Development Study of Early Child Care and Youth Development who were measured at 54 months, first grade, and third grade. Latent factors of anger and attention span were structured using different indicators based on mothers', fathers', caregivers', teachers', and observers' reports. We used structural equation modeling to examine the autoregressive effects within a context (stability), the concurrent associations between home and classroom contexts, and informant effects. The results indicated that for both anger and attention (1) there were significant informant effects that influenced stability in a context, (2) there was higher stability in home context than nonhome context, and (3) stability within a context increased over time. The findings suggested that anger was more prone to context effects and informant effects than attention.

Hierarchy of stability factors in reverse shoulder arthroplasty.

PubMed

Gutiérrez, Sergio; Keller, Tony S; Levy, Jonathan C; Lee, William E; Luo, Zong-Ping

2008-03-01

Reverse shoulder arthroplasty is being used more frequently to treat irreparable rotator cuff tears in the presence of glenohumeral arthritis and instability. To date, however, design features and functions of reverse shoulder arthroplasty, which may be associated with subluxation and dislocation of these implants, have been poorly understood. We asked: (1) what is the hierarchy of importance of joint compressive force, prosthetic socket depth, and glenosphere size in relation to stability, and (2) is this hierarchy defined by underlying and theoretically predictable joint contact characteristics? We examined the intrinsic stability in terms of the force required to dislocate the humerosocket from the glenosphere of eight commercially available reverse shoulder arthroplasty devices. The hierarchy of factors was led by compressive force followed by socket depth; glenosphere size played a much lesser role in stability of the reverse shoulder arthroplasty device. Similar results were predicted by a mathematical model, suggesting the stability was determined primarily by compressive forces generated by muscles.

Stability of Beriplast P fibrin sealant: storage and reconstitution.

PubMed

Eberhard, Ulrich; Broder, Martin; Witzke, Günther

2006-04-26

This study was performed to investigate the stability of Beriplast P fibrin sealant (FS) across a range of storage conditions, both pre- and post-reconstitution. Storage stability of the FS was evaluated during long-term refrigeration (24 months) with or without interim storage at elevated temperatures (40 degrees C for 1 week and 25 degrees C for 1 and 3 months). Stability of individual FS components was assessed by measuring: fibrinogen content, Factor XIII activity (FXIII), thrombin activity and aprotinin potency. The package integrity of each component was also checked (sterility testing, moisture content and pH). Storage stability was also evaluated by testing the reconstituted product for adhesion (tearing force testing after mixing the solutions) and sterility. Reconstitution stability was evaluated following 3-months' storage, for up to 50 h post-reconstitution using the same tests as for the storage stability investigations. Pre-defined specifications were met for fibrinogen content, Factor XIII activity, and thrombin activity, demonstrating storage stability. Package integrity and the functionality and sterility of the reconstituted product were confirmed throughout. Reconstitution stability was demonstrated for up to 50 h following reconstitution, in terms of both tearing force and sterility tests. In conclusion, the storage stability of Beriplast P was demonstrated over a range of 24-month storage schedules including interim exposure to elevated temperature, and the reconstituted product was stable for up to 50 h.

Comparison of Factorization-Based Filtering for Landing Navigation

NASA Technical Reports Server (NTRS)

McCabe, James S.; Brown, Aaron J.; DeMars, Kyle J.; Carson, John M., III

2017-01-01

This paper develops and analyzes methods for fusing inertial navigation data with external data, such as data obtained from an altimeter and a star camera. The particular filtering techniques are based upon factorized forms of the Kalman filter, specifically the UDU and Cholesky factorizations. The factorized Kalman filters are utilized to ensure numerical stability of the navigation solution. Simulations are carried out to compare the performance of the different approaches along a lunar descent trajectory using inertial and external data sources. It is found that the factorized forms improve upon conventional filtering techniques in terms of ensuring numerical stability for the investigated landing navigation scenario.

Conformational stability of the epidermal growth factor (EGF) receptor as influenced by glycosylation, dimerization and EGF hormone binding.

PubMed

Taylor, Eric S; Pol-Fachin, Laercio; Lins, Roberto D; Lower, Steven K

2017-04-01

The epidermal growth factor receptor (EGFR) is an important transmembrane glycoprotein kinase involved the initiation or perpetuation of signal transduction cascades within cells. These processes occur after EGFR binds to a ligand [epidermal growth factor (EGF)], thus inducing its dimerization and tyrosine autophosphorylation. Previous publications have highlighted the importance of glycosylation and dimerization for promoting proper function of the receptor and conformation in membranes; however, the effects of these associations on the protein conformational stability have not yet been described. Molecular dynamics simulations were performed to characterize the conformational preferences of the monomeric and dimeric forms of the EGFR extracellular domain upon binding to EGF in the presence and absence of N-glycan moieties. Structural stability analyses revealed that EGF provides the most conformational stability to EGFR, followed by glycosylation and dimerization, respectively. The findings also support that EGF-EGFR binding takes place through a large-scale induced-fitting mechanism. Proteins 2017; 85:561-570. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

An investigation into the stability of commercial versus MG63-derived hepatocyte growth factor under flow cultivation conditions.

PubMed

Meneghello, Giulia; Storm, Michael P; Chaudhuri, Julian B; De Bank, Paul A; Ellis, Marianne J

2015-03-01

The scale-up of tissue engineering cell culture must ensure that conditions are maintained while also being cost effective. Here we analyse the stability of hepatocyte growth factor (HGF) to investigate whether concentrations change under dynamic conditions, and compare commercial recombinant human HGF as an additive in 'standard medium', to HGF secreted by the osteosarcoma cell line MG63 as a 'preconditioned medium'. After 3 h under flow conditions, HGF in the standard medium degraded to 40% of its original concentration but HGF in the preconditioned medium remained at 100%. The concentration of secreted HGF was 10 times greater than the working concentration of commercially-available HGF. Thus HGF within this medium has increased stability; MG63-derived HGF should therefore be investigated as a cost-effective alternative to current lyophilised powders for use in in vitro models. Furthermore, we recommend that those intending to use HGF (or other growth factors) should consider similar stability testing before embarking on experiments with media flow.

Myopia Stabilization and Associated Factors Among Participants in the Correction of Myopia Evaluation Trial (COMET)

PubMed Central

2013-01-01

Purpose. To use the Gompertz function to estimate the age and the amount of myopia at stabilization and to evaluate associated factors in the Correction of Myopia Evaluation Trial (COMET) cohort, a large ethnically diverse group of myopic children. Methods. The COMET enrolled 469 ethnically diverse children aged 6 to younger than 12 years with spherical equivalent refraction between −1.25 and −4.50 diopters (D). Noncycloplegic refraction was measured semiannually for 4 years and annually thereafter. Right eye data were fit to individual Gompertz functions in participants with at least 6 years of follow-up and at least seven refraction measurements over 11 years. Function parameters were estimated using a nonlinear least squares procedure. Associated factors were evaluated using linear regression. Results. In total, 426 participants (91%) had valid Gompertz curve fits. The mean (SD) age at myopia stabilization was 15.61 (4.17) years, and the mean (SD) amount of myopia at stabilization was −4.87 (2.01) D. Ethnicity (P < 0.0001) but not sex or the number of myopic parents was associated with the age at stabilization. Ethnicity (P = 0.02) and the number of myopic parents (P = 0.01) but not sex were associated with myopia magnitude at stabilization. At stabilization, African Americans were youngest (mean age, 13.82 years) and had the least myopia (mean, −4.36 D). Participants with two versus no myopic parents had approximately 1.00 D more myopia at stabilization. The age and the amount of myopia at stabilization were correlated (r = −0.60, P < 0.0001). Conclusions. The Gompertz function provides estimates of the age and the amount of myopia at stabilization in an ethnically diverse cohort. These findings should provide guidance on the time course of myopia and on decisions regarding the type and timing of interventions. PMID:24159085

The Russian Federation Islamic Republic of Dagestan: Curricular Decentralization, Social Cohesion, and Stability

ERIC Educational Resources Information Center

Eaton, Jana Sackman

2005-01-01

This article focuses on the curricular decentralization-sociopolitical stability nexus in the predominantly Muslim Russian Federation Republic of Dagestan, adjacent to war-torn Chechnya. Concomitant with the metamorphoses taking place in the economic and political sectors of society is the overhaul of institutionalized education. A major reform…

SYNTHESIS AND APPLICATION OF A NEW CLASS OF STABILIZED NANOSCALE IRON PARTICLES FOR RAPID DESTRUCTION OF CHLORINATED HYDROCARBONS IN SOIL AND GROUNDWATER

EPA Science Inventory

In accord with the research objectives, this project achieved the following major results:

1. Developed a new method for synthesizing a new class of starch- or carboxymethyl cellulose stabilized ZVI nanoparticles of controllable size and transportability. ...

2. Family Dysfunctions and Ways of Their Overcoming by Means of Social Work

   ERIC Educational Resources Information Center

   Astoyants, Margaret S.; Kovalev, Vitaly V.; Davljatova, Svetlana V.; Shevchenko, Olga N.

   2016-01-01

   The article presents the problem of stability of modern society. The issue is studied in terms of family as one of the major social institutions. Social stability of the family is due to constructive interpersonal relationships of its members. Cooperation and partnership, fellow feeling and freedom of choice, interesting work and…

3. The Use of Polymerized Genipin for the Stabilization of the Collagen Structure of Animal Hides

   USDA-ARS?s Scientific Manuscript database

   Animal hides are the major byproduct of meat industry and the collagen fibers is the main constituent. Crosslinkers play a key role in stabilizing the collagen structure for useful applications. Genipin is widely used as an ideal biological protein crosslinking agent due to its low toxicity compare...

4. Encapsulation of indole-3-carbinol and 3'3'-diindolylmethane in zein/carboxymethyl chitosan nanoparticles with controlled release property and improved stability

   USDA-ARS?s Scientific Manuscript database

   Indole-3-carbinol (I3C) and diindolylmethane (DIM) are two bioactive compounds from Cruciferous vegetables. Their stabilities are the major challenges for their pharmaceutical applications. In this study, zein and zein/carboxymethyl chitosan (zein/CMCS) nanoparticles have been prepared to encapsulat...

5. Improvement of water resistance and dimensional stability of wood through titanium dioxide coating

   Treesearch

   Qingfeng Sun; Haipeng Yu; Yixing Liu; Jian Li; Yun Lu; John F. Hunt

   2010-01-01

   Moisture absorption and dimensional distortion are the major drawbacks of wood utilization as building material. In this study, poplar wood coated with a thin layer of titanium dioxide (TiO2) was prepared by the cosolvent-controlled hydrothermal method. Subsequently, its moisture absorption and dimensional stability were examined. Scanning...

6. Color attributes and oxidative stability of longissimus lumborum and psoas major muscles from Nellore bulls.

   PubMed

   Canto, Anna C V C S; Costa-Lima, Bruno R C; Suman, Surendranath P; Monteiro, Maria Lucia G; Viana, Fernanda M; Salim, Ana Paula A A; Nair, Mahesh N; Silva, Teofilo J P; Conte-Junior, Carlos A

   2016-11-01

   The influence of muscle source on color stability of fresh beef from purebred Bos indicus cattle was investigated. Longissimus lumborum (LL) and psoas major (PM) muscles obtained from twelve (n=12) Nellore bull carcasses (24h post-mortem) were fabricated into 2.54-cm steaks, aerobically packaged, and stored at 4°C for nine days. Steaks were analyzed on day 0 for proximate composition and myoglobin concentration, whereas pH, instrumental color, metmyoglobin reducing activity (MRA), lipid oxidation, and protein oxidation were evaluated on days 0, 3, 6, and 9. LL steaks exhibited greater (P<0.05) redness, color stability, and MRA than PM counterparts. On the other hand, PM steaks demonstrated greater (P<0.05) myoglobin content, lipid oxidation, and protein oxidation than LL steaks. These results indicated the critical influence of muscle source on discoloration of fresh beef from Bos indicus animals and suggested the necessity to engineer muscle-specific strategies to improve color stability and marketability of beef from Bos indicus cattle. Copyright © 2016 Elsevier Ltd. All rights reserved.

7. Zn2+ selectively stabilizes FdU-substituted DNA through a unique major groove binding motif

   PubMed Central

   Ghosh, Supratim; Salsbury, Freddie R.; Horita, David A.; Gmeiner, William H.

   2011-01-01

   We report, based on semi-empirical calculations, that Zn2+ binds duplex DNA containing consecutive FdU–dA base pairs in the major groove with distorted trigonal bipyramidal geometry. In this previously uncharacterized binding motif, O4 and F5 on consecutive FdU are axial ligands while three water molecules complete the coordination sphere. NMR spectroscopy confirmed Zn2+ complexation occurred with maintenance of base pairing while a slight hypsochromic shift in circular dichroism (CD) spectra indicated moderate structural distortion relative to B-form DNA. Zn2+ complexation inhibited ethidium bromide (EtBr) intercalation and stabilized FdU-substituted duplex DNA (ΔTm > 15°C). Mg2+ neither inhibited EtBr complexation nor had as strong of a stabilizing effect. DNA sequences that did not contain consecutive FdU were not stabilized by Zn2+. A lipofectamine preparation of the Zn2+–DNA complex displayed enhanced cytotoxicity toward prostate cancer cells relative to the individual components prepared as lipofectamine complexes indicating the potential utility of Zn2+–DNA complexes for cancer treatment. PMID:21296761

8. Synthesis of 5-(1,2,3-triazol-4-yl)-2'-deoxyuridines by a click chemistry approach: stacking of triazoles in the major groove gives increased nucleic acid duplex stability.

   PubMed

   Kocalka, Petr; Andersen, Nicolai K; Jensen, Frank; Nielsen, Poul

   2007-11-23

   A general protocol for converting alkyl and aryl halides into azides and for converting these in situ into 1,4-disubstituted triazoles was applied with 5-ethynyl-2'-deoxyuridine. This afforded three modified 2'-deoxyuridine analogues with either unsubstituted or 1-phenyl-/1-benzyl-substituted triazoles in their 5-positions. Modelling demonstrates coplanarity of the two heteroaromatic rings, and UV spectroscopy showed the uracil pK(a) values to be almost unchanged. The three nucleosides were introduced into nonamer oligonucleotides by phosphoramidite chemistry. The heteroaromatic triazoles became positioned in the major grooves of the short dsDNA and DNA-RNA duplexes. While single modifications led to decreased duplex stability, the stacking of four consecutive modifications led to enhanced duplex stability, especially for DNA-RNA duplexes. The duplex structures were studied by CD spectroscopy and molecular dynamics simulations, which supported the conjecture that the duplex stabilizing effect is due to efficient stacking of the heteroaromatic triazoles.

9. High hydrostatic pressure inactivation of Lactobacillus plantarum cells in (O/W)-emulsions is independent from cell surface hydrophobicity and lipid phase parameters

   NASA Astrophysics Data System (ADS)

   Kafka, T. A.; Reitermayer, D.; Lenz, C. A.; Vogel, R. F.

   2017-07-01

   Inactivation efficiency of high hydrostatic pressure (HHP) processing of food is strongly affected by food matrix composition. We investigated effects of fat on HHP inactivation of spoilage-associated Lactobacillus (L.) plantarum strains using defined oil-in-water (O/W)-emulsion model systems. Since fat-mediated effects on HHP inactivation could be dependent on interactions between lipid phase and microbial cells, three major factors possibly influencing such interactions were considered, that is, cell surface hydrophobicity, presence and type of surfactants, and oil droplet size. Pressure tolerance varied noticeably among L. plantarum strains and was independent of cell surface hydrophobicity. We showed that HHP inactivation of all strains tended to be more effective in presence of fat. The observation in both, surfactant-stabilized and surfactant-free (O/W)-emulsion, indicates that cell surface hydrophobicity is no intrinsic pressure resistance factor. In contrast to the presence of fat per se, surfactant type and oil droplet size did not affect inactivation efficiency.

10. Inefficient DNA Repair Is an Aging-Related Modifier of Parkinson's Disease.

    PubMed

    Sepe, Sara; Milanese, Chiara; Gabriels, Sylvia; Derks, Kasper W J; Payan-Gomez, Cesar; van IJcken, Wilfred F J; Rijksen, Yvonne M A; Nigg, Alex L; Moreno, Sandra; Cerri, Silvia; Blandini, Fabio; Hoeijmakers, Jan H J; Mastroberardino, Pier G

    2016-05-31

    The underlying relation between Parkinson's disease (PD) etiopathology and its major risk factor, aging, is largely unknown. In light of the causative link between genome stability and aging, we investigate a possible nexus between DNA damage accumulation, aging, and PD by assessing aging-related DNA repair pathways in laboratory animal models and humans. We demonstrate that dermal fibroblasts from PD patients display flawed nucleotide excision repair (NER) capacity and that Ercc1 mutant mice with mildly compromised NER exhibit typical PD-like pathological alterations, including decreased striatal dopaminergic innervation, increased phospho-synuclein levels, and defects in mitochondrial respiration. Ercc1 mouse mutants are also more sensitive to the prototypical PD toxin MPTP, and their transcriptomic landscape shares important similarities with that of PD patients. Our results demonstrate that specific defects in DNA repair impact the dopaminergic system and are associated with human PD pathology and might therefore constitute an age-related risk factor for PD. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

11. An overview of structure, mechanical properties, and treatment for age-related tendinopathy.

    PubMed

    Zhou, B; Zhou, Y; Tang, K

    2014-04-01

    Tendons transfer tensile loads from muscle to bone, which enable joint motions and stabilize joints. Tendons sustain large mechanical loads in vivo and as a result, tendons were frequently injured. Aging has been confirmed as a predisposing factor of tendinopathy and bad recovery quality following tendon repair. Current treatment methods are generally not effective and involve either symptomatic relief with non-steroidal antiinflammatory drugs and physical therapy or surgery when conservative treatments failed. The limitation in treatment options is due to our incomplete knowledge of age-related tendinopathy. Studies over the past decades have uncovered a number of important mechanical and cellular changes of aging tendon. However, the basis of aging as a major risk factor for tendon injury and impaired tendon healing remained poorly understood. The objectives of this review are to provide an overview of the current knowledge about the aging-associated changes of structure, mechanical properties and treatment in tendon and highlight causes and therapies for age-related tendinopathy.

FANCD2 functions as a critical factor downstream of MiTF to maintain the proliferation and survival of melanoma cells.

PubMed

Bourseguin, Julie; Bonet, Caroline; Renaud, Emilie; Pandiani, Charlotte; Boncompagni, Marina; Giuliano, Sandy; Pawlikowska, Patrycja; Karmous-Benailly, Houda; Ballotti, Robert; Rosselli, Filippo; Bertolotto, Corine

2016-11-09

Proteins involved in genetic stability maintenance and safeguarding DNA replication act not only against cancer initiation but could also play a major role in sustaining cancer progression. Here, we report that the FANC pathway is highly expressed in metastatic melanoma harboring the oncogenic microphthalmia-associated transcription factor (MiTF). We show that MiTF downregulation in melanoma cells lowers the expression of several FANC genes and proteins. Moreover, we observe that, similarly to the consequence of MiTF downregulation, FANC pathway silencing alters proliferation, migration and senescence of human melanoma cells. We demonstrate that the FANC pathway acts downstream MiTF and establish the existence of an epistatic relationship between MiTF and the FANC pathway. Our findings point to a central role of the FANC pathway in cellular and chromosomal resistance to both DNA damage and targeted therapies in melanoma cells. Thus, the FANC pathway is a promising new therapeutic target in melanoma treatment.

FANCD2 functions as a critical factor downstream of MiTF to maintain the proliferation and survival of melanoma cells

PubMed Central

Bourseguin, Julie; Bonet, Caroline; Renaud, Emilie; Pandiani, Charlotte; Boncompagni, Marina; Giuliano, Sandy; Pawlikowska, Patrycja; Karmous-Benailly, Houda; Ballotti, Robert; Rosselli, Filippo; Bertolotto, Corine

2016-01-01

Proteins involved in genetic stability maintenance and safeguarding DNA replication act not only against cancer initiation but could also play a major role in sustaining cancer progression. Here, we report that the FANC pathway is highly expressed in metastatic melanoma harboring the oncogenic microphthalmia-associated transcription factor (MiTF). We show that MiTF downregulation in melanoma cells lowers the expression of several FANC genes and proteins. Moreover, we observe that, similarly to the consequence of MiTF downregulation, FANC pathway silencing alters proliferation, migration and senescence of human melanoma cells. We demonstrate that the FANC pathway acts downstream MiTF and establish the existence of an epistatic relationship between MiTF and the FANC pathway. Our findings point to a central role of the FANC pathway in cellular and chromosomal resistance to both DNA damage and targeted therapies in melanoma cells. Thus, the FANC pathway is a promising new therapeutic target in melanoma treatment. PMID:27827420

Examining Factors Associated with (In)Stability in Social Information Processing among Urban School Children: A Latent Transition Analytic Approach

ERIC Educational Resources Information Center

Goldweber, Asha; Bradshaw, Catherine P.; Goodman, Kimberly; Monahan, Kathryn; Cooley-Strickland, Michele

2011-01-01

There is compelling evidence for the role of social information processing (SIP) in aggressive behavior. However, less is known about factors that influence stability versus instability in patterns of SIP over time. Latent transition analysis was used to identify SIP patterns over one year and examine how community violence exposure, aggressive…

The Longitudinal Stability and Dynamics of Group Membership in the Dual-Factor Model of Mental Health: Psychosocial Predictors of Mental Health

ERIC Educational Resources Information Center

Kelly, Ryan M.; Hills, Kimberly J.; Huebner, E. Scott; McQuillin, Samuel D.

2012-01-01

This study examined the longitudinal stability and dynamics of group membership within the Greenspoon and Sakflofske's dual-factor model of mental health. This expanded model incorporates information about subjective well-being (SWB), in addition to psychopathological symptoms, to better identify the mental health status and current functioning of…

Relationship between locked modes and thermal quenches in DIII-D

DOE PAGES

Sweeney, R.; Choi, W.; Austin, M.; ...

2018-03-28

Locked modes are known to be one of the major causes of disruptions, but the physical mechanisms by which locking leads to disruptions are not well understood. For this study, we analyze the evolution of the temperature profile in the presence of multiple coexisting locked modes during partial and full thermal quenches. Partial quenches are often observed to be an initial, distinct stage in the full thermal quench. Near the onset of partial quenches, locked island O-points are observed to align with each other on the midplane, and their widths are sufficient to overlap each other, as indicated by themore » Chirikov parameter. Energy conservation analysis of one partial thermal quench shows that the energy lost is both radiated in the divertor region, and conducted or convected to the divertor. Nonlinear resistive magnetohydrodynamic simulations support the interpretation of stochastic fields causing a partial axisymmetric collapse, though the simulated temperature profile exhibits less degradation than the experimental profiles. In discharges with minimum values of the safety factor above ~1.2, locked modes are observed to self-stabilize by inducing, possibly via double tearing modes, a minor disruption that removes their neoclassical drive. These high q min discharges often exhibit relatively low ratios of the plasma internal inductance to the safety factor at 95% of the poloidal flux, which might imply classical stability, in agreement with the decay of the mode when the neoclassical drive is removed.« less

Major occurrences and reservoir concepts of marine clathrate hydrates: Implications of field evidence

USGS Publications Warehouse

Booth, J.S.; Winters, W.J.; Dillon, William P.; Clennell, M.B.; Rowe, M.M.

1998-01-01

This paper is part of the special publication Gas hydrates: relevance to world margin stability and climatic change (eds J.P. Henriet and J. Mienert). Questions concerning clathrate hydrate as an energy resource, as a factor in modifying global climate and as a triggering mechanism for mass movements invite consideration of what factors promote hydrate concentration, and what the quintessential hydrate-rich sediment may be. Gas hydrate field data, although limited, provide a starting point for identifying the environments and processes that lead to more massive concentrations. Gas hydrate zones are up to 30 m thick and the vertical range of occurrence at a site may exceed 200 m. Zones typically occur more than 100m above the phase boundary. Thicker zones are overwhelmingly associated with structural features and tectonism, and often contain sand. It is unclear whether an apparent association between zone thickness and porosity represents a cause-and-effect relationship. The primary control on the thickness of a potential gas hydrate reservoir is the geological setting. Deep water and low geothermal gradients foster thick gas hydrate stability zones (GHSZs). The presence of faults, fractures, etc. can favour migration of gas-rich fluids. Geological processes, such as eustacy or subsidence, may alter the thickness of the GHSZ or affect hydrate concentratiion. Tectonic forces may promote injection of gas into the GHSZ. More porous and permeable sediment, as host sediment properties, increase storage capacity and fluid conductivity, and thus also enhance reservoir potential.

Relationship between locked modes and thermal quenches in DIII-D

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

Sweeney, R.; Choi, W.; Austin, M.

Locked modes are known to be one of the major causes of disruptions, but the physical mechanisms by which locking leads to disruptions are not well understood. For this study, we analyze the evolution of the temperature profile in the presence of multiple coexisting locked modes during partial and full thermal quenches. Partial quenches are often observed to be an initial, distinct stage in the full thermal quench. Near the onset of partial quenches, locked island O-points are observed to align with each other on the midplane, and their widths are sufficient to overlap each other, as indicated by themore » Chirikov parameter. Energy conservation analysis of one partial thermal quench shows that the energy lost is both radiated in the divertor region, and conducted or convected to the divertor. Nonlinear resistive magnetohydrodynamic simulations support the interpretation of stochastic fields causing a partial axisymmetric collapse, though the simulated temperature profile exhibits less degradation than the experimental profiles. In discharges with minimum values of the safety factor above ~1.2, locked modes are observed to self-stabilize by inducing, possibly via double tearing modes, a minor disruption that removes their neoclassical drive. These high q min discharges often exhibit relatively low ratios of the plasma internal inductance to the safety factor at 95% of the poloidal flux, which might imply classical stability, in agreement with the decay of the mode when the neoclassical drive is removed.« less

Determinants of energy efficiency across countries

NASA Astrophysics Data System (ADS)

Yao, Guolin

With economic development, environmental concerns become more important. Economies cannot be developed without energy consumption, which is the major source of greenhouse gas emissions. Higher energy efficiency is one means of reducing emissions, but what determines energy efficiency? In this research we attempt to find answers to this question by using cross-sectional country data; that is, we examine a wide range of possible determinants of energy efficiency at the country level in an attempt to find the most important causal factors. All countries are divided into three income groups: high-income countries, middle-income countries, and low-income countries. Energy intensity is used as a measurement of energy efficiency. All independent variables belong to two categories: quantitative and qualitative. Quantitative variables are measures of the economic conditions, development indicators and energy usage situations. Qualitative variables mainly measure political, societal and economic strengths of a country. The three income groups have different economic and energy attributes. Each group has different sets of variables to explain energy efficiency. Energy prices and winter temperature are both important in high-income and middle-income countries. No qualitative variables appear in the model of high-income countries. Basic economic factors, such as institutions, political stability, urbanization level, population density, are important in low-income countries. Besides similar variables, such as macroeconomic stability and index of rule of law, the hydroelectricity share in total electric generation is also a driver of energy efficiency in middle-income countries. These variables have different policy implications for each group of countries.

The Physics of Basis For A Conservative Physics And Conservative Technology Tokamak Power Plant, ARIES-ACT2

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

Kessel, C. E.; Poli, F. M.

2014-03-04

The conservative physics and conservative technology tokamak power plant ARIES-ACT2 has a major radius of 9.75 m at aspect ratio of 4.0, strong shaping with elongation of 2.2 and triangularity of 0.63. The no wall βN reaches ~ 2.4, limited by n=1 external kink mode, and can be extended to 3.2 with a stabilizing shell behind the ring structure shield. The bootstrap current fraction is 77% with a q95 of 8.0, requiring about ~ 4.0 MA of external current drive. This current is supplied with 30 MW of ICRF/FW and 80 MW of negative ion NB. Up to 1.0 MAmore » can be driven with LH with no wall, and 1.5 or more MA can be driven with a stabilizing shell. EC was examined and is most effective for safety factor control over ρ ~ 0.2-0.6 with 20 MW. The pedestal density is ~ 0.65x10 20/m 3 and the temperature is ~ 9.0 keV. The H98 factor is 1.25, n/n Gr = 1.3, and the net power to LH threshold power is 1.3-1.4 in the flattop. Due to the high toroidal field and high central temperature the cyclotron radiation loss was found to be high depending on the first wall reflectivity.« less

Dimensional stabilization of southern pines

Treesearch

E.T. Choong; H.M. Barnes

1969-01-01

The effectiveness of five dimensional stabilizing agents and three impregnation methods on southern pine was determined. Four southern pine species were studies in order to determine the effect of wood factors. The best dimensional stability was obtained when the wood was preswollen and the chemical was impregnated by a diffusion process. In general, polyethylene...

Prediction and Stability of Mathematics Skill and Difficulty

ERIC Educational Resources Information Center

Martin, Rebecca B.; Cirino, Paul T.; Barnes, Marcia A.; Ewing-Cobbs, Linda; Fuchs, Lynn S.; Stuebing, Karla K.; Fletcher, Jack M.

2013-01-01

The present study evaluated the stability of math learning difficulties over a 2-year period and investigated several factors that might influence this stability (categorical vs. continuous change, liberal vs. conservative cut point, broad vs. specific math assessment); the prediction of math performance over time and by performance level was also…

Electromyographic activity of selected scapular stabilizers during glenohumeral internal and external rotation contractions.

PubMed

Schachter, Aaron K; McHugh, Malachy P; Tyler, Timothy F; Kreminic, Ian J; Orishimo, Karl F; Johnson, Christopher; Ben-Avi, Simon; Nicholas, Stephen J

2010-09-01

An important synergistic relationship exists between the scapular stabilizers and the glenohumeral rotators. Information on the relative contribution of the scapular stabilizers to glenohumeral rotation would be useful for exercise prescription for overhead athletes and for patients with shoulder pathology. We hypothesized that the scapular stabilizers would be highly active during both maximal and submaximal internal and external rotation. Eight healthy male volunteers (16 shoulders) performed internal and external glenohumeral rotation testing at maximal and submaximal intensities. They also performed a scapular retraction rowing exercise at maximal and submaximal levels. Electromyographic (EMG) signals were recorded from the infraspinatus, pectoralis major, serratus anterior, and middle trapezius. Values were compared among muscle groups, among individual muscles at different intensity levels, and among individual muscles at different points in the arc of motion. For submaximal glenohumeral internal rotation, activity in the scapular stabilizers was not different (P = .1-.83) from activity in the internal rotator throughout the range of motion. For the initial two-thirds of maximal internal rotation, middle trapezius activity and pectoralis major activity were higher (P < .05) than serratus anterior activity. For submaximal external rotation, activity in the scapular stabilizers during the middle phase of the motion was higher (P < .05) than activity in the external rotators. For maximal external rotation these differences were present throughout the motion with middle trapezius activity exceeding 100% maximal voluntary contraction. The scapular stabilizers functioned at a similar or higher intensity than the glenohumeral rotators during internal and external rotation. This highlights the importance of training the scapular stabilizers in upper extremity athletes and in patients with shoulder pathology. (c) 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Effects of iron-aluminium oxides and organic carbon on aggregate stability of bauxite residues.

PubMed

Zhu, Feng; Li, Yubing; Xue, Shengguo; Hartley, William; Wu, Hao

2016-05-01

In order to successfully establish vegetation on bauxite residue, properties such as aggregate structure and stability require improvement. Spontaneous plant colonization on the deposits in Central China over the last 20 years has revealed that natural processes may improve the physical condition of bauxite residues. Samples from three different stacking ages were selected to determine aggregate formation and stability and its relationship with iron-aluminium oxides and organic carbon. The residue aggregate particles became coarser in both dry and wet sieving processes. The mean weight diameter (MWD) and geometry mean diameter (GMD) increased significantly, and the proportion of aggregate destruction (PAD) decreased. Natural stacking processes could increase aggregate stability and erosion resistant of bauxite residues. Free iron oxides and amorphous aluminium oxides were the major forms in bauxite residues, but there was no significant correlation between the iron-aluminium oxides and aggregate stability. Aromatic-C, alkanes-C, aliphatic-C and alkenes-C were the major functional groups present in the residues. With increasing stacking age, total organic carbon content and aggregate-associated organic carbon both increased. Alkanes-C, aliphatic-C and alkenes-C increased and were mainly distributed in macro-aggregates, whereas aromatic-C was mainly distributed in <0.05-mm aggregates. Organic carbon stability in micro-aggregates was higher than that in macro-aggregates and became more stable. Organic carbon contents in total residues, and within different aggregate sizes, were all negatively correlated with PAD. It indicated that organic materials had a more significant effect on macro-aggregate stability and the effects of iron-aluminium oxides maybe more important for stability of micro-aggregates.

Characterizing executive functioning in older special populations: from cognitively elite to cognitively impaired.

PubMed

de Frias, Cindy M; Dixon, Roger A; Strauss, Esther

2009-11-01

The authors examined the structure and invariance of executive functions (EF) across (a) a continuum of cognitive status in 3 groups of older adults (cognitively elite [CE], cognitively normal [CN], and cognitively impaired [CI]) and (b) a 3-year longitudinal interval. Using latent variable analyses (LISREL 8.80), the authors tested 3-factor models ("Inhibition": Hayling [Burgess & Shallice, 1997], Stroop [Regard, 1981]; "Shifting": Brixton [Burgess & Shallice, 1997], Color Trails [D'Elia et al., 1996]; and "Updating": Reading and Computational Span [Salthouse & Babcock, 1991]) and 1-factor models within each group. Participants (initial N = 570; 53-90 years) were from the Victoria Longitudinal Study (Sample 3, Waves 1 and 2). Cross-sectionally, the authors observed a 3-factor EF structure especially for the CE group and 1-factor solutions for all 3 groups. Longitudinally, temporal invariance was supported for the 3-factor model (CE and CN groups) and the 1-factor model (CI and CN groups). Subgroups with higher cognitive status and greater 3-year stability performed better on EF factors than corresponding groups with lower cognitive status and less stability. Studies of EF structure, performance, dedifferentiation, and dysfunction will benefit from considering initial cognitive status and longitudinal stability.

Cognitive impairment, dementia, and personality stability among older adults

PubMed Central

Terracciano, Antonio; Stephan, Yannick; Luchetti, Martina; Sutin, Angelina R.

2017-01-01

There is contrasting evidence on personality stability in advanced age, and limited knowledge on the impact of cognitive impairment and dementia on trait stability. Group- and individual-level longitudinal analyses of the five major dimensions of personality assessed twice over 4-years (N = 9,935) suggest that rank-order stability was progressively lower with advancing age (from rtt = 0.68 for age 50–60 to rtt = 0.58 for age >80 years). Stability was low in the dementia group (rtt = 0.43), and this was not simply due to lower reliability given that internal consistency remained adequate in the dementia group. Among individuals with no cognitive impairment or dementia, there was no association between stability and age (rtt = 0.70 even for age >80). These results suggest that the lower personality stability in older adults is not due to age but cognitive impairment and dementia. PMID:29214858

The Causes and Dynamics of Conflict in Sub-Saharan Africa

DTIC Science & Technology

2009-05-10

economic stability gained from two trends: the spread of constitutional democracy and economic globalization. Two major occurrences, colonialism and the Cold War, prevented the Sub-Saharan states from following these two trends. The disruption in sovereignty caused by colonialism, which was then followed by hastily formed governments during the Cold War, spawned conditions of corruption, scarcity, and violent competition. These conditions make it difficult for African states to achieve lasting stability and advance economically. As a result, any stability gained is often

System and method of operating toroidal magnetic confinement devices

DOEpatents

Chance, Morrell S.; Jardin, Stephen C.; Stix, Thomas H.; Grimm, deceased, Ray C.; Manickam, Janardhan; Okabayashi, Michio

1987-01-01

For toroidal magnetic confinement devices the second region of stability against ballooning modes can be accessed with controlled operation. Under certain modes of operation, the first and second stability regions may be joined together. Accessing the second region of stability is accomplished by forming a bean-shaped plasma and increasing the indentation until a critical value of indentation is reached. A pusher coil, located at the inner-major-radius side of the device, is engaged to form a bean-shaped poloidal cross-section in the plasma.

A Cell Culture Approach to Optimized Human Corneal Endothelial Cell Function

PubMed Central

Bartakova, Alena; Kuzmenko, Olga; Alvarez-Delfin, Karen; Kunzevitzky, Noelia J.; Goldberg, Jeffrey L.

2018-01-01

Purpose Cell-based therapies to replace corneal endothelium depend on culture methods to optimize human corneal endothelial cell (HCEC) function and minimize endothelial-mesenchymal transition (EnMT). Here we explore contribution of low-mitogenic media on stabilization of phenotypes in vitro that mimic those of HCECs in vivo. Methods HCECs were isolated from cadaveric donor corneas and expanded in vitro, comparing continuous presence of exogenous growth factors (“proliferative media”) to media without those factors (“stabilizing media”). Identity based on canonical morphology and expression of surface marker CD56, and function based on formation of tight junction barriers measured by trans-endothelial electrical resistance assays (TEER) were assessed. Results Primary HCECs cultured in proliferative media underwent EnMT after three to four passages, becoming increasingly fibroblastic. Stabilizing the cells before each passage by switching them to a media low in mitogenic growth factors and serum preserved canonical morphology and yielded a higher number of cells. HCECs cultured in stabilizing media increased both expression of the identity marker CD56 and also tight junction monolayer integrity compared to cells cultured without stabilization. Conclusions HCECs isolated from donor corneas and expanded in vitro with a low-mitogenic media stabilizing step before each passage demonstrate more canonical structural and functional features and defer EnMT, increasing the number of passages and total canonical cell yield. This approach may facilitate development of HCEC-based cell therapies. PMID:29625488

Frequency stability of maser oscillators operated with cavity Q. [hydrogen and rubidium masers

NASA Technical Reports Server (NTRS)

Tetu, M.; Tremblay, P.; Lesage, P.; Petit, P.; Audoin, C.

1982-01-01

The short term frequency stability of masers equipped with an external feedback loop to increase the cavity quality factor was studied. The frequency stability of a hydrogen and a rubidium maser were measured and compared with theoretical evaluation. It is shown that the frequency stability passes through an optimum when the cavity Q is varied. Long term fluctuations are discussed and the optimum mid term frequency stability achievably by small size active and passive H-masers is considered.

Earthworms are associated with subpopulations of Gammaproteobacteria irrespective of the total soil microbiota composition and stability.

PubMed

Fjøsne, Trine; Myromslien, Frøydis D; Wilson, Robert C; Rudi, Knut

2018-05-01

Soil represents one of the most complex microbial ecosystems on earth. It is well-known that invertebrates such as earthworms have a major impact on transformations of organic material in soil, while their effect on the soil microbiota remains largely unknown. The aim of our work was therefore to investigate the association of earthworms with temporal stability, composition and diversity in two soil microbiota experimental series. We found that earthworms were consistently associated with an increase in subgroups of Gammaproteobacteria, despite major differences in microbiota composition and temporal stability across the experimental series. Our results therefore suggest that earthworms can affect subpopulation dynamics in the soil microbiota, irrespective of the total microbiota composition. If the soil microbiota is comprised of independent microbiota components, this can contribute to our general understanding of the complexity of the soil microbiota.

KEY INTERACTIONS FOR CLATHRIN COAT STABILITY

PubMed Central

Böcking, Till; Aguet, Francois; Rapoport, Iris; Banzhaf, Manuel; Yu, Anan; Zeeh, Jean Christophe; Kirchhausen, Tom

2014-01-01

SUMMARY Clathrin-coated vesicles are major carriers of vesicular traffic in eukaryotic cells. This endocytic pathway relies on cycles of clathrin coat assembly and Hsc70-mediated disassembly. Here we identify histidine residues as major determinants of lattice assembly and stability. They are located at the invariant interface between the proximal and distal segments of clathrin heavy chains, in triskelions centered on two adjacent vertices of the coated-vesicle lattice. Mutation of these histidine to glutamine alters the pH dependence of coat stability. We then describe single-particle fluorescence imaging experiments in which we follow the effect of these histidine mutations on susceptibility to Hsc70-dependent uncoating. Coats destabilized by these mutations require fewer Hsc70 molecules to initiate disassembly as predicted by a model in which Hsc70 traps conformational distortions during the auxilin- and Hsc70:ATP-mediated uncoating reaction. PMID:24815030

Aggregate stability as an indicator of soil erodibility and soil physical quality: review and perspectives

NASA Astrophysics Data System (ADS)

Le Bissonnais, Yves; Chenu, Claire; Darboux, Frédéric; Duval, Odile; Legout, Cédric; Leguédois, Sophie; Gumiere, Silvio

2010-05-01

Aggregate breakdown due to water and rain action may cause surface crusting, slumping, a reduction of infiltration and interrill erosion. Aggregate stability determines the capacity of aggregates to resist the effects of water and rainfall. In this paper, we evaluated and reviewed the relevance of an aggregate stability measurement to characterize soil physical properties as well as to analyse the processes involved in these properties. Stability measurement assesses the sensitivity of soil aggregates to various basic disaggregation mechanisms such as slaking, differential swelling, dispersion and mechanical breakdown. It has been showed that aggregate size distributions of structural stability tests matched the size distributions of eroded aggregates under rainfall simulations and that erosion amount was well predicted using aggregate stability indexes. It means stability tests could be used to estimate both the erodibility and the size fractions that are available for crust formation and erosion processes. Several studies showed that organic matter was one of the main soil properties affecting soil stability. However, it has also been showed that aggregate stability of a given soil could vary within a year or between years. The factors controlling such changes have still to be specified. Aggregate stability appears therefore as a complex property, depending both on permanent soil characteristics and on dynamic factors such as the crusting stage, the climate and the biological activity. Despite, and may be, because of this complexity, aggregate stability seems an integrative and powerful indicator of soil physical quality. Future research efforts should look at the causes of short-term changes of structural stability, in order to fully understand all its aspects.

High-throughput screening and stability optimization of anti-streptavidin IgG1 and IgG2 formulations.

PubMed

Alekseychyk, Larysa; Su, Cheng; Becker, Gerald W; Treuheit, Michael J; Razinkov, Vladimir I

2014-10-01

Selection of a suitable formulation that provides adequate product stability is an important aspect of the development of biopharmaceutical products. Stability of proteins includes not only resistance to chemical modifications but also conformational and colloidal stabilities. While chemical degradation of antibodies is relatively easy to detect and control, propensity for conformational changes and/or aggregation during manufacturing or long-term storage is difficult to predict. In many cases, the formulation factors that increase one type of stability may significantly decrease another type under the same or different conditions. Often compromise is necessary to minimize the adverse effects of an antibody formulation by careful optimization of multiple factors responsible for overall stability. In this study, high-throughput stress and characterization techniques were applied to 96 formulations of anti-streptavidin antibodies (an IgG1 and an IgG2) to choose optimal formulations. Stress and analytical methods applied in this study were 96-well plate based using an automated liquid handling system to prepare the different formulations and sample plates. Aggregation and clipping propensity were evaluated by temperature and mechanical stresses. Multivariate regression analysis of high-throughput data was performed to find statistically significant formulation factors that alter measured parameters such as monomer percentage or unfolding temperature. The results of the regression models were used to maximize the stabilities of antibodies under different formulations and to find the optimal formulation space for each molecule. Comparison of the IgG1 and IgG2 data indicated an overall greater stability of the IgG1 molecule under the conditions studied. The described method can easily be applied to both initial preformulation screening and late-stage formulation development of biopharmaceutical products. © 2014 Society for Laboratory Automation and Screening.

Allele-specific Characterization of Alanine: Glyoxylate Aminotransferase Variants Associated with Primary Hyperoxaluria

PubMed Central

Lage, Melissa D.; Pittman, Adrianne M. C.; Roncador, Alessandro; Cellini, Barbara; Tucker, Chandra L.

2014-01-01

Primary Hyperoxaluria Type 1 (PH1) is a rare autosomal recessive kidney stone disease caused by deficiency of the peroxisomal enzyme alanine: glyoxylate aminotransferase (AGT), which is involved in glyoxylate detoxification. Over 75 different missense mutations in AGT have been found associated with PH1. While some of the mutations have been found to affect enzyme activity, stability, and/or localization, approximately half of these mutations are completely uncharacterized. In this study, we sought to systematically characterize AGT missense mutations associated with PH1. To facilitate analysis, we used two high-throughput yeast-based assays: one that assesses AGT specific activity, and one that assesses protein stability. Approximately 30% of PH1-associated missense mutations are found in conjunction with a minor allele polymorphic variant, which can interact to elicit complex effects on protein stability and trafficking. To better understand this allele interaction, we functionally characterized each of 34 mutants on both the major (wild-type) and minor allele backgrounds, identifying mutations that synergize with the minor allele. We classify these mutants into four distinct categories depending on activity/stability results in the different alleles. Twelve mutants were found to display reduced activity in combination with the minor allele, compared with the major allele background. When mapped on the AGT dimer structure, these mutants reveal localized regions of the protein that appear particularly sensitive to interactions with the minor allele variant. While the majority of the deleterious effects on activity in the minor allele can be attributed to synergistic interaction affecting protein stability, we identify one mutation, E274D, that appears to specifically affect activity when in combination with the minor allele. PMID:24718375

An adaptive optics imaging system designed for clinical use.

PubMed

Zhang, Jie; Yang, Qiang; Saito, Kenichi; Nozato, Koji; Williams, David R; Rossi, Ethan A

2015-06-01

Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2-3 arc minutes, (arcmin) 2) ~0.5-0.8 arcmin and, 3) ~0.05-0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3-5 arcmin, 2) ~0.7-1.1 arcmin and 3) ~0.07-0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.

Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.

PubMed

Dror, Adi; Kanteev, Margarita; Kagan, Irit; Gihaz, Shalev; Shahar, Anat; Fishman, Ayelet

2015-11-01

Enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. Methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. However, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactivation of the biocatalyst. Therefore, a methanol-stable lipase is of great interest for the biodiesel industry. In this study, protein engineering was applied to substitute charged surface residues with hydrophobic ones to enhance the stability in methanol of a lipase from Geobacillus stearothermophilus T6. We identified a methanol-stable variant, R374W, and combined it with a variant found previously, H86Y/A269T. The triple mutant, H86Y/A269T/R374W, had a half-life value at 70 % methanol of 324 min which reflects an 87-fold enhanced stability compared to the wild type together with elevated thermostability in buffer and in 50 % methanol. This variant also exhibited an improved biodiesel yield from waste chicken oil compared to commercial Lipolase 100L® and Novozyme® CALB. Crystal structures of the wild type and the methanol-stable variants provided insights regarding structure-stability correlations. The most prominent features were the extensive formation of new hydrogen bonds between surface residues directly or mediated by structural water molecules and the stabilization of Zn and Ca binding sites. Mutation sites were also characterized by lower B-factor values calculated from the X-ray structures indicating improved rigidity.

Fabric phase sorptive extraction followed by UHPLC-MS/MS for the analysis of benzotriazole UV stabilizers in sewage samples.

PubMed

Montesdeoca-Esponda, Sarah; Sosa-Ferrera, Zoraida; Kabir, Abuzar; Furton, Kenneth G; Santana-Rodríguez, José Juan

2015-10-01

A fast and sensitive sample preparation strategy using fabric phase sorptive extraction followed by ultra-high-performance liquid chromatography and tandem mass spectrometry detection has been developed to analyse benzotriazole UV stabilizer compounds in aqueous samples. Benzotriazole UV stabilizer compounds are a group of compounds added to sunscreens and other personal care products which may present detrimental effects to aquatic ecosystems. Fabric phase sorptive extraction is a novel solvent minimized sample preparation approach that integrates the advantages of sol-gel derived hybrid inorganic-organic nanocomposite sorbents and the flexible, permeable and hydrophobic surface chemistry of polyester fabric. It is a highly sensitive, fast, efficient and inexpensive device that can be reused and does not suffer from coating damage, unlike SPME fibres or stir bars. In this paper, we optimized the extraction of seven benzotriazole UV filters evaluating the majority of the parameters involved in the extraction process, such as sorbent chemistry selection, extraction time, back-extraction solvent, back-extraction time and the impact of ionic strength. Under the optimized conditions, fabric phase sorptive extraction allows enrichment factors of 10 times with detection limits ranging from 6.01 to 60.7 ng L(-1) and intra- and inter-day % RSDs lower than 11 and 30 % for all compounds, respectively. The optimized sample preparation technique followed by ultra-high-performance liquid chromatography and tandem mass spectrometry detection was applied to determine the target analytes in sewage samples from wastewater treatment plants with different purification processes of Gran Canaria Island (Spain). Two UV stabilizer compounds were measured in ranges 17.0-60.5 ng mL(-1) (UV 328) and 69.3-99.2 ng mL(-1) (UV 360) in the three sewage water samples analysed.

Reduced transport potential of a palladium-doped zero valent iron nanoparticle in a water saturated loamy sand.

PubMed

Basnet, Mohan; Di Tommaso, Caroline; Ghoshal, Subhasis; Tufenkji, Nathalie

2015-01-01

Direct in situ injection of palladium-doped nanosized zero valent iron (Pd-NZVI) particles can contribute to remediation of various environmental contaminants. A major challenge encountered is rapid aggregation of Pd-NZVI and hence very limited mobility. To reduce aggregation and concurrently improve particle mobility, the surface of bare Pd-NZVI can be modified with stabilizing surface modifiers. Selected surface-modified Pd-NZVI has shown dramatically improved stability and transport. However, little is known regarding the effects of aquifer grain geochemical heterogeneity on the transport and deposition behavior of surface-modified Pd-NZVI. Herein, the mobility of surface stabilized Pd-NZVI in two granular matrices representative of model ground water environments (quartz sand and loamy sand) was assessed over a wide range of environmentally relevant ionic strengths (IS). Carboxymethyl cellulose (CMC), soybean flour and rhamnolipid biosurfactant were used as Pd-NZVI surface modifiers. Our results show that, both in quartz sand and loamy sand, an increase in solution IS results in reduced Pd-NZVI transport. Moreover, at a given water chemistry, Pd-NZVI transport is notably attenuated in loamy sand implying that geochemical heterogeneity associated with loamy sand is a key factor influencing Pd-NZVI transport potential. Experiments conducted at a higher Pd-NZVI particle concentration, to be more representative of field conditions, show that rhamnolipid and CMC are effective stabilizing agents even when 1 g/L Pd-NZVI is injected into quartz sand. Overall, this study emphasizes the extent to which variation in groundwater chemistry, coupled with changes in aquifer geochemistry, could dramatically alter the transport potential of Pd-NZVI in the subsurface environment.

Crystal structure of the alkaline proteinase Savinase from Bacillus lentus at 1.4 A resolution.

PubMed

Betzel, C; Klupsch, S; Papendorf, G; Hastrup, S; Branner, S; Wilson, K S

1992-01-20

Savinase (EC3.4.21.14) is secreted by the alkalophilic bacterium Bacillus lentus and is a representative of that subgroup of subtilisin enzymes with maximum stability in the pH range 7 to 10 and high activity in the range 8 to 12. It is therefore of major industrial importance for use in detergents. The crystal structure of the native form of Savinase has been refined using X-ray diffraction data to 1.4 A resolution. The starting model was that of subtilisin Carlsberg. A comparison to the structures of the closely related subtilisins Carlsberg and BPN' and to the more distant thermitase and proteinase K is presented. The structure of Savinase is very similar to those of homologous Bacillus subtilisins. There are two calcium ions in the structure, equivalent to the strong and the weak calcium-binding sites in subtilisin Carlsberg and subtilisin BPN', well known for their stabilizing effect on the subtilisins. The structure of Savinase shows novel features that can be related to its stability and activity. The relatively high number of salt bridges in Savinase is likely to contribute to its high thermal stability. The non-conservative substitutions and deletions in the hydrophobic binding pocket S1 result in the most significant structural differences from the other subtilisins. The different composition of the S1 binding loop as well as the more hydrophobic character of the substrate-binding region probably contribute to the alkaline activity profile of the enzyme. The model of Savinase contains 1880 protein atoms, 159 water molecules and two calcium ions. The crystallographic R-factor [formula; see text].

Study on the Influence of Elevation of Tailing Dam on Stability

NASA Astrophysics Data System (ADS)

Wan, Shuai; Wang, Kun; Kong, Songtao; Zhao, Runan; Lan, Ying; Zhang, Run

2017-12-01

This paper takes Yunnan as the object of a tailing, by theoretical analysis and numerical calculation method of the effect of seismic load effect of elevation on the stability of the tailing, to analyse the stability of two point driven safety factor and liquefaction area. The Bishop method is adopted to simplify the calculation of dynamic safety factor and liquefaction area analysis using comparison method of shear stress to analyse liquefaction, so we obtained the influence of elevation on the stability of the tailing. Under the earthquake, with the elevation increased, the safety coefficient of dam body decreases, shallow tailing are susceptible to liquefy. Liquefaction area mainly concentrated in the bank below the water surface, to improve the scientific basis for the design and safety management of the tailing.

Tumor protein D52 expression is post-transcriptionally regulated by T-cell intercellular antigen (TIA) 1 and TIA-related protein via mRNA stability.

PubMed

Motohashi, Hiromi; Mukudai, Yoshiki; Ito, Chihiro; Kato, Kosuke; Shimane, Toshikazu; Kondo, Seiji; Shirota, Tatsuo

2017-05-04

Although tumor protein D52 (TPD52) family proteins were first identified nearly 20 years ago, their molecular regulatory mechanisms remain unclear. Therefore, we investigated the post-transcriptional regulation of TPD52 family genes. An RNA immunoprecipitation (RIP) assay showed the potential binding ability of TPD52 family mRNAs to several RNA-binding proteins, and an RNA degradation assay revealed that TPD52 is subject to more prominent post-transcriptional regulation than are TPD53 and TPD54. We subsequently focused on the 3'-untranslated region (3'-UTR) of TPD52 as a cis -acting element in post-transcriptional gene regulation. Several deletion mutants of the 3'-UTR of TPD52 mRNA were constructed and ligated to the 3'-end of a reporter green fluorescence protein gene. An RNA degradation assay revealed that a minimal cis -acting region, located in the 78-280 region of the 5'-proximal region of the 3'-UTR, stabilized the reporter mRNA. Biotin pull-down and RIP assays revealed specific binding of the region to T-cell intracellular antigen 1 (TIA-1) and TIA-1-related protein (TIAR). Knockdown of TIA-1/TIAR decreased not only the expression, but also the stability of TPD52 mRNA; it also decreased the expression and stability of the reporter gene ligated to the 3'-end of the 78-280 fragment. Stimulation of transforming growth factor-β and epidermal growth factor decreased the binding ability of these factors, resulting in decreased mRNA stability. These results indicate that the 78-280 fragment and TIA-1/TIAR concordantly contribute to mRNA stability as a cis -acting element and trans -acting factor(s), respectively. Thus, we here report the specific interactions between these elements in the post-transcriptional regulation of the TPD52 gene. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Time stability of spring and superconducting gravimeters through the analysis of very long gravity records

NASA Astrophysics Data System (ADS)

Calvo, Marta; Hinderer, Jacques; Rosat, Severine; Legros, Hilaire; Boy, Jean-Paul; Ducarme, Bernard; Zürn, Walter

2014-10-01

Long gravity records are of great interest when performing tidal analyses. Indeed, long series enable to separate contributions of near-frequency waves and also to detect low frequency signals (e.g. long period tides and polar motion). In addition to the length of the series, the quality of the data and the temporal stability of the noise are also very important. We study in detail some of the longest gravity records available in Europe: 3 data sets recorded with spring gravimeters in Black Forest Observatory (Germany, 1980-2012), Walferdange (Luxemburg, 1980-1995) and Potsdam (Germany, 1974-1998) and several superconducting gravimeters (SGs) data sets, with at least 9 years of continuous records, at different European GGP (Global Geodynamics Project) sites (Bad Homburg, Brussels, Medicina, Membach, Moxa, Vienna, Wettzell and Strasbourg). The stability of each instrument is investigated using the temporal variations of tidal parameters (amplitude factor and phase difference) for the main tidal waves (O1, K1, M2 and S2) as well as the M2/O1 factor ratio, the later being insensitive to the instrumental calibration. The long term stability of the tidal observations is also dependent on the stability of the scale factor of the relative gravimeters. Therefore we also check the time stability of the scale factor for the superconducting gravimeter C026 installed at the J9 Gravimetric Observatory of Strasbourg (France), using numerous calibration experiments carried out by co-located absolute gravimeter (AG) measurements during the last 15 years. The reproducibility of the scale factor and the achievable precision are investigated by comparing the results of different calibration campaigns. Finally we present a spectrum of the 25 years of SG records at J9 Observatory, with special attention to small amplitude tides in the semi-diurnal and diurnal bands, as well as to the low frequency part.

Recent progress in degradation and stabilization of organic solar cells

NASA Astrophysics Data System (ADS)

Cao, Huanqi; He, Weidong; Mao, Yiwu; Lin, Xiao; Ishikawa, Ken; Dickerson, James H.; Hess, Wayne P.

2014-10-01

Stability is of paramount importance in organic semiconductor devices, especially in organic solar cells (OSCs). Serious degradation in air limits wide applications of these flexible, light-weight and low-cost power-generation devices. Studying the stability of organic solar cells will help us understand degradation mechanisms and further improve the stability of these devices. There are many investigations into the efficiency and stability of OSCs. The efficiency and stability of devices even of the same photoactive materials are scattered in different papers. In particular, the extrinsic degradation that mainly occurs near the interface between the organic layer and the cathode is a major stability concern. In the past few years, researchers have developed many new cathodes and cathode buffer layers, some of which have astonishingly improved the stability of OSCs. In this review article, we discuss the recent developments of these materials and summarize recent progresses in the study of the degradation/stability of OSCs, with emphasis on the extrinsic degradation/stability that is related to the intrusion of oxygen and water. The review provides detailed insight into the current status of research on the stability of OSCs and seeks to facilitate the development of highly-efficient OSCs with enhanced stability.

Comparing the Developmental Genetics of Cognition and Personality over the Life Span.

PubMed

Briley, Daniel A; Tucker-Drob, Elliot M

2017-02-01

Empirical studies of cognitive ability and personality have tended to operate in isolation of one another. We suggest that returning to a unified approach to considering the development of individual differences in both cognition and personality can enrich our understanding of human development. We draw on previous meta-analyses of longitudinal, behavior genetic studies of cognition and personality across the life span, focusing particular attention on age trends in heritability and differential stability. Both cognition and personality are moderately heritable and exhibit large increases in stability with age; however, marked differences are evident. First, the heritability of cognition increases substantially with child age, while the heritability of personality decreases modestly with age. Second, increasing stability of cognition with age is overwhelmingly mediated by genetic factors, whereas increasing stability of personality with age is entirely mediated by environmental factors. Third, the maturational time-course of stability differs: Stability of cognition nears its asymptote by the end of the first decade of life, whereas stability of personality takes three decades to near its asymptote. We discuss how proximal gene-environment dynamics, developmental processes, broad social contexts, and evolutionary pressures may intersect to give rise to these divergent patterns. © 2015 Wiley Periodicals, Inc.

Comparing the Developmental Genetics of Cognition and Personality over the Lifespan

PubMed Central

Briley, Daniel A.; Tucker-Drob, Elliot M.

2015-01-01

Objective Empirical studies of cognitive ability and personality have tended to operate in isolation of one another. We suggest that returning to a unified approach to considering the development of individual differences in both cognition and personality can enrich our understanding of human development. Method We draw on previous meta-analyses of longitudinal, behavior genetic studies of cognition and personality across the lifespan, focusing particular attention on age trends in heritability and differential stability. Results Both cognition and personality are moderately heritable and exhibit large increases in stability with age; however, marked differences are evident. First, the heritability of cognition increases substantially with child age, while the heritability of personality decreases modestly with age. Second, increasing stability of cognition with age is overwhelmingly mediated by genetic factors, whereas increasing stability of personality with age is entirely mediated by environmental factors. Third, the maturational time-course of stability differs: Stability of cognition nears its asymptote by the end of the first decade of life, whereas stability of personality takes three decades to near its asymptote. Conclusions We discuss how proximal gene-environment dynamics, developmental processes, broad social contexts, and evolutionary pressures may intersect to give rise to these divergent patterns. PMID:26045299

Beta-hairpin formation in aqueous solution and in the presence of trifluoroethanol: a (1)H and (13)C nuclear magnetic resonance conformational study of designed peptides.

PubMed

Santiveri, Clara M; Pantoja-Uceda, David; Rico, Manuel; Jiménez, M Angeles

2005-10-15

In order to check our current knowledge on the principles involved in beta-hairpin formation, we have modified the sequence of a 3:5 beta-hairpin forming peptide with two different purposes, first to increase the stability of the formed 3:5 beta-hairpin, and second to convert the 3:5 beta-hairpin into a 2:2 beta-hairpin. The conformational behavior of the designed peptides was investigated in aqueous solution and in 30% trifluoroethanol (TFE) by analysis of the following nuclear magnetic resonance (NMR) parameters: nuclear Overhauser effect (NOE) data, and C(alpha)H, (13)C(alpha), and (13)C(beta) conformational shifts. From the differences in the ability to adopt beta-hairpin structures in these peptides, we have arrived to the following conclusions: (i) beta-Hairpin population increases with the statistical propensity of residues to occupy each turn position. (ii) The loop length, and in turn, the beta-hairpin type, can be modified as a function of the type of turn favored by the loop sequence. These two conclusions reinforce previous results about the importance of beta-turn sequence in beta-hairpin folding. (iii) Side-chain packing on each face of the beta-sheet may play a major role in beta-hairpin stability; hence simplified analysis in terms of isolated pair interactions and intrinsic beta-sheet propensities is insufficient. (iv) Contributions to beta-hairpin stability of turn and strand sequences are not completely independent. (v) The burial of hydrophobic surface upon beta-hairpin formation that, in turn, depends on side-chain packing also contributes to beta-hairpin stability. (vi) As previously observed, TFE stabilizes beta-hairpin structures, but the extent of the contribution of different factors to beta-hairpin formation is sometimes different in aqueous solution and in 30% TFE. (c) 2005 Wiley Periodicals, Inc. Biopolymers 79: 150-162, 2005.

Side-chain-side-chain interactions and stability of the helical state

NASA Astrophysics Data System (ADS)

Zangi, Ronen

2014-01-01

Understanding the driving forces that lead to the stability of the secondary motifs found in proteins, namely α-helix and β-sheet, is a major goal in structural biology. The thermodynamic stability of these repetitive units is a result of a delicate balance between many factors, which in addition to the peptide chain involves also the solvent. Despite the fact that the backbones of all amino acids are the same (except of that of proline), there are large differences in the propensity of the different amino acids to promote the helical structure. In this paper, we investigate by explicit-solvent molecular dynamics simulations the role of the side chains (modeled as coarse-grained single sites) in stabilizing α helices in an aqueous solution. Our model systems include four (six-mer-nine-mer) peptide lengths in which the magnitude of the effective attraction between the side chains is systematically increased. We find that these interactions between the side chains can induce (for the nine-mer almost completely) a transition from a coil to a helical state. This transition is found to be characterized by three states in which the intermediate state is a partially folded α-helical conformation. In the absence of any interactions between the side chains the free energy change for helix formation has a small positive value indicating that favorable contributions from the side chains are necessary to stabilize the helical conformation. Thus, the helix-coil transition is controlled by the effective potentials between the side-chain residues and the magnitude of the required attraction per residue, which is on the order of the thermal energy, reduces with the length of the peptide. Surprisingly, the plots of the population of the helical state (or the change in the free energy for helix formation) as a function of the total effective interactions between the side chains in the helical state for all peptide lengths fall on the same curve.

Humidity versus photo-stability of metal halide perovskite films in a polymer matrix.

PubMed

Manshor, Nurul Ain; Wali, Qamar; Wong, Ka Kan; Muzakir, Saifful Kamaluddin; Fakharuddin, Azhar; Schmidt-Mende, Lukas; Jose, Rajan

2016-08-21

Despite the high efficiency of over 21% reported for emerging thin film perovskite solar cells, one of the key issues prior to their commercial deployment is to attain their long term stability under ambient and outdoor conditions. The instability in perovskite is widely conceived to be humidity induced due to the water solubility of its initial precursors, which leads to decomposition of the perovskite crystal structure; however, we note that humidity alone is not the major degradation factor and it is rather the photon dose in combination with humidity exposure that triggers the instability. In our experiment, which is designed to decouple the effect of humidity and light on perovskite degradation, we investigate the shelf-lifetime of CH3NH3PbI3 films in the dark and under illumination under high humidity conditions (Rel. H. > 70%). We note minor degradation in perovskite films stored in a humid dark environment whereas upon exposure to light, the films undergo drastic degradation, primarily owing to the reactive TiO2/perovskite interface and also the surface defects of TiO2. To enhance its air-stability, we incorporate CH3NH3PbI3 perovskite in a polymer (poly-vinylpyrrolidone, PVP) matrix which retained its optical and structural characteristics in the dark for ∼2000 h and ∼800 h in room light soaking, significantly higher than a pristine perovskite film, which degraded completely in 600 h in the dark and in less than 100 h when exposed to light. We attribute the superior stability of PVP incorporated perovskite films to the improved structural stability of CH3NH3PbI3 and also to the improved TiO2/perovskite interface upon incorporating a polymer matrix. Charge injection from the polymer embedded perovskite films has also been confirmed by fabricating solar cells using them, thereby providing a promising future research pathway for stable and efficient perovskite solar cells.

Density controls the kinetic stability of ultrastable glasses

NASA Astrophysics Data System (ADS)

Fullerton, Christopher J.; Berthier, Ludovic

2017-08-01

We use a swap Monte Carlo algorithm to numerically prepare bulk glasses with kinetic stability comparable to that of glass films produced experimentally by physical vapor deposition. By melting these systems into the liquid state, we show that some of our glasses retain their amorphous structures longer than 105 times the equilibrium structural relaxation time. This “exceptional” kinetic stability cannot be achieved for bulk glasses produced by slow cooling. We perform simulations at both constant volume and constant pressure to demonstrate that the density mismatch between the ultrastable glass and the equilibrium liquid accounts for a major part of the observed kinetic stability.

Long term in vitro stability of fully integrated wireless neural interfaces based on Utah slant electrode array

NASA Astrophysics Data System (ADS)

Sharma, Asha; Rieth, Loren; Tathireddy, Prashant; Harrison, Reid; Solzbacher, Florian

2010-02-01

We herein report in vitro functional stability and recording longevity of a fully integrated wireless neural interface (INI). The INI uses biocompatible Parylene-C as an encapsulation layer, and was immersed in phosphate buffered saline (PBS) for a period of over 150 days. The full functionality (wireless radio-frequency power, command, and signal transmission) and the ability of INI to record artificial action potentials even after 150 days of PBS soaking without any change in signal/noise amplitude constitutes a major milestone in long term stability, and evaluate the encapsulation reliability, functional stability, and potential usefulness for future chronic implants.

Role of organic and inorganic cations on thermal behavior of lead iodide perovskites

NASA Astrophysics Data System (ADS)

Singh, Rajan Kumar; Dash, Saumya R.; Kumar, Ranveer; Jain, Neha; Singh, Jai

2018-04-01

Recently, organic-inorganic perovskite materials have attracted much attention due to their enormous potential for use in future of new sustainable energy sources. However, fabrication of environmental friendly perovskite and achieving better stability is a major concern towards the commercialization. Here we study the role of cations in the perovskite powder and their influence upon thermodynamic stability. In this study we find, inorganic (cesium, Cs+) cation is shown to be more efficient in the thermal stabilization of the perovskite material than organic (methylamine, CH3NH2+) cation. This study reviles that stability of perovskite can be improved by incorporation of inorganic cation.

Therapeutics of postpartum depression.

PubMed

Thomson, Michael; Sharma, Verinder

2017-05-01

Postpartum depression is a prevalent disorder affecting many women of reproductive age. Despite increasing public awareness, it is frequently underdiagnosed and undertreated leading to significant maternal morbidity and adverse child outcomes. When identified, postpartum depression is usually treated as major depressive disorder. Many studies have identified the postpartum as a period of high risk for first presentations and relapses of bipolar disorder. Areas covered: This article reviews the acute and prophylactic treatment of postpartum major depressive disorder, bipolar depression and major depressive disorder with mixed features. The safety of antidepressant and mood stabilizing medications in pregnancy and breastfeeding will also be reviewed. Expert commentary: Differentiating postpartum major depressive disorder and postpartum bipolar depression can be difficult given their clinical similarities but accurate identification is vital for initiating proper treatment. Antidepressants are the mainstay of drug treatment for postpartum major depressive disorder, yet randomized controlled trials have shown conflicting results. A paucity of evidence exists for the effectiveness of antidepressant prophylaxis in the prevention of recurrences of major depressive disorder. Mood stabilizing medications reduce the risk of postpartum bipolar depression relapse but no randomized controlled trials have examined their use in the acute or prophylactic treatment of postpartum bipolar depression.

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

Results of revision anterior shoulder stabilization surgery in adolescent athletes.

PubMed

Blackman, Andrew J; Krych, Aaron J; Kuzma, Scott A; Chow, Roxanne M; Camp, Christopher; Dahm, Diane L

2014-11-01

The purpose of this study was to determine failure rates, functional outcomes, and risk factors for failure after revision anterior shoulder stabilization surgery in high-risk adolescent athletes. Adolescent athletes who underwent primary anterior shoulder stabilization were reviewed. Patients undergoing subsequent revision stabilization surgery were identified and analyzed. Failure rates after revision surgery were assessed by Kaplan-Meier analysis. Failure was defined as recurrent instability requiring reoperation. Functional outcomes included the Marx activity score; American Shoulder and Elbow Surgeons score; and University of California, Los Angeles score. The characteristics of patients who required reoperation for recurrent instability after revision surgery were compared with those of patients who required only a single revision to identify potential risk factors for failure. Of 90 patients who underwent primary anterior stabilization surgery, 15 (17%) had failure and underwent revision surgery (mean age, 16.6 years; age range, 14 to 18 years). The mean follow-up period was 5.5 years (range, 2 to 12 years). Of the 15 revision patients, 5 (33%) had recurrent dislocations and required repeat revision stabilization surgery at a mean of 50 months (range, 22 to 102 months) after initial revision. No risk factors for failure were identified. The Kaplan-Meier reoperation-free estimates were 86% (95% confidence interval, 67% to 100%) at 24 months and 78% (95% confidence interval, 56% to 100%) at 48 months after revision surgery. The mean final Marx activity score was 14.8 (range, 5 to 20); American Shoulder and Elbow Surgeons score, 82.1 (range, 33 to 100); and University of California, Los Angeles score, 30.8 (range, 16 to 35). At 5.5 years' follow-up, adolescent athletes had a high failure rate of revision stabilization surgery and modest functional outcomes. We were unable to convincingly identify specific risk factors for failure of revision surgery. Level IV, retrospective therapeutic case series. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Characteristics of Residual Symptoms in Korean Patients with Major Depressive Disorder: A Validation Study for the Korean Version of Depression Residual Symptom Scale.

PubMed

Park, Sol A; Jeon, Sang Won; Yoon, Ho-Kyoung; Yoon, Seo Young; Shin, Cheolmin; Ko, Young-Hoon

2018-02-01

Residual symptoms of depression are related to more severe and chronic course of functional impairment with higher risk of relapse. The objective of this study was to validate, and determine psychometric properties of the Korean version of Depression Residual Symptom Scale (KDRSS). A total of 203 outpatients with recent episode of major depression based on DSM-IV criteria were enrolled in this study. They had been treated with antidepressants and assessed by KDRSS, Hamilton Depression Rating Scale-24 (HDRS-24), and Montgomery-Åsberg Depression Rating Scale (MARDS). The validity and reliability of KDRSS were assessed, including internal consistency reliability, concurrent validity, temporal stability, factorial validity, and discriminative validity. Internal consistency (Cronbach's alpha=0.961), concurrent validity (MADRS: r=0.731, p<0.01, HDRS-24: r=0.663, p<0.01), and temporal stability (r=0.726, p<0.01) of KDRSS were all excellent. KDRSS showed good discriminative validity based on MARDS. KDRSS consisted of one-factor structure accounting for 63.8% of total variance. All subjects except two in full remission group had one or more residual symptoms. In 7 subscales of KDRSS consisting of similar items respectively, 'lack of energy' was the most commonly reported, followed by 'increased emotionalism' in this group. KDRSS is a useful and sensitive instrument for measuring residual depressive symptoms. Since some depressive symptoms including 'lack of energy' and 'increased emotionalism' in patients with full remission might be persistent during psychiatric intervention, these symptoms need to be focused on in clinical practice.

Behavior of radionuclides in sanitary landfills.

PubMed

Chang, K C; Chian, E S; Pohland, F G; Cross, W H; Roland, L; Kahn, B

1984-01-01

his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.

Systematic off-pump coronary artery revascularization in multivessel disease: experience of three hundred cases.

PubMed

Cartier, R; Brann, S; Dagenais, F; Martineau, R; Couturier, A

2000-02-01

We sought to report our recent experience with off-pump coronary artery revascularization in multivessel disease. Between October 1996 and December 1998, 300 off-pump beating heart operations were performed at the Montreal Heart Institute by a single surgeon, representing 94% of all procedures undertaken during this same time frame (97% for 1998). This cohort of patients was compared with 1870 patients operated on with cardiopulmonary bypass from 1995 to 1996. Mean age, sex distribution, and preoperative risk factors were comparable for the two groups. On average, 2.92 +/- 0.8 and 2.84 +/- 0.6 grafts per patient were completed in the beating heart and cardiopulmonary bypass groups, respectively. A majority of patients (70%) had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization." Ischemic time was shorter in the beating heart group (29.8 +/- 0.9 vs 45 +/- 0.4 minutes, P <.05). Similarly, the need for transfusion was significantly less in the beating heart group (beating heart operations, 34%; cardiopulmonary bypass, 66%; P <.005). Reduced use of postoperative intra-aortic counterpulsation, as well as a lower rise in creatine kinase MB isoenzyme, was observed in the beating heart group. Operative mortality rates (beating heart operations, 1. 3%; cardiopulmonary bypass, 2%) and perioperative myocardial infarction (beating heart operations, 3.6%; cardiopulmonary bypass, 4.2%) were comparable for the two groups. In a majority of patients, off-pump complete coronary artery revascularization is an acceptable alternative to conventional operations, yielding good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

N-phosphino-p-tolylsulfinamide ligands: synthesis, stability, and application to the intermolecular Pauson-Khand reaction.

PubMed

Revés, Marc; Achard, Thierry; Solà, Jordi; Riera, Antoni; Verdaguer, Xavier

2008-09-19

Here we synthesized a family of racemic and optically pure N-phosphino-p-tolylsulfinamide (PNSO) ligands. Their stability and coordination behavior toward dicobalt-alkyne complexes was evaluated. Selectivities of up to 3:1 were achieved in the ligand exchange process with (mu-TMSC2H)Co2(CO)6. The resulting optically pure major complexes were tested in the asymmetric intermolecular Pauson-Khand reaction and yielded up to 94% ee. X-ray studies of the major complex 18a indicated that the presence of an aryl group on the sulfinamide reduces the hemilabile character of the PNSO ligands.

Family Stability as a Protective Factor against Psychopathology for Urban Children Receiving Psychological Services

ERIC Educational Resources Information Center

Ivanova, Masha Y.; Israel, Allen C.

2006-01-01

Family stability, defined as the consistency of family activities and routines, was examined in a sample of urban families (n = 70) with children (ages 7 to 16) receiving psychological services. Parent-reported family stability was associated with lower parent-reported children's internalizing behavior problems. Child-reported family stability…

REGIONAL, BASIN, AND LOCAL FACTORS INFLUENCING THE USE OF SYNOPTIC SURVEY DATA TO ASSESS ANTHROPOGENIC CHANGES IN STREAMBED STABILITY AND FINE SEDIMENT

EPA Science Inventory

To evaluate anthropogenic changes in stream bed stability or texture from synoptic stream surveys, we calculated relative bed stability RBS* as the ratio of the geometric mean bed surface substrate diameter to the estimated bankfull critical diameter. RBS* decreased with increas...

Compositional stability of boreal understorey vegetation after overstorey harvesting across a riparian ecotone

Treesearch

Rebecca L. MacDonald; Han Y.H. Chen; Samuel F. Bartels; Brian J. Palik; Ellie E. Prepas; Frank Gilliam

2015-01-01

Questions: Understanding factors that contribute to the stability of an ecosystem following harvesting is central to predicting responses of boreal ecosystems to increasing human disturbances.While the response of understorey vegetation to harvesting is well understood for upland sites, little is known about compositional stability of riparian understorey vegetation....

Experimental analysis of multivariate female choice in gray treefrogs (Hyla versicolor): evidence for directional and stabilizing selection.

PubMed

Gerhardt, H Carl; Brooks, Robert

2009-10-01

Even simple biological signals vary in several measurable dimensions. Understanding their evolution requires, therefore, a multivariate understanding of selection, including how different properties interact to determine the effectiveness of the signal. We combined experimental manipulation with multivariate selection analysis to assess female mate choice on the simple trilled calls of male gray treefrogs. We independently and randomly varied five behaviorally relevant acoustic properties in 154 synthetic calls. We compared response times of each of 154 females to one of these calls with its response to a standard call that had mean values of the five properties. We found directional and quadratic selection on two properties indicative of the amount of signaling, pulse number, and call rate. Canonical rotation of the fitness surface showed that these properties, along with pulse rate, contributed heavily to a major axis of stabilizing selection, a result consistent with univariate studies showing diminishing effects of increasing pulse number well beyond the mean. Spectral properties contributed to a second major axis of stabilizing selection. The single major axis of disruptive selection suggested that a combination of two temporal and two spectral properties with values differing from the mean should be especially attractive.

Balancing activity, stability and conductivity of nanoporous core-shell iridium/iridium oxide oxygen evolution catalysts

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

Kim, Yong-Tae; Lopes, Pietro Papa; Park, Shin-Ae

The selection of oxide materials for catalyzing the Oxygen Evolution Reaction in acid-based electrolyzers must be guided by the proper balance between activity, stability and conductivity – a challenging mission of great importance for delivering affordable and environmentally friendly hydrogen. Here we report that the highly conductive nanoporous architecture of an iridium oxide shell on a metallic iridium core, formed through the fast dealloying of osmium from an Ir25Os75 alloy, exhibits an exceptional balance between oxygen evolution activity and stability as quantified by the Activity-Stability FactorASF. Based on this metric, the nanoporous Ir/IrO2 morphology of dealloyed Ir25Os75 shows a factormore » of ~30 improvement ASFrelative to conventional Ir-based oxide materials and a ~8 times improvement over dealloyed Ir25Os75 nanoparticles due to optimized stability and conductivity, respectively. We propose that the Activity-Stability FactorASF is the key “metric” for determining the technological relevance of oxide-based anodic water electrolyzer catalysts.« less

Risk analysis of gravity dam instability using credibility theory Monte Carlo simulation model.

PubMed

Xin, Cao; Chongshi, Gu

2016-01-01

Risk analysis of gravity dam stability involves complicated uncertainty in many design parameters and measured data. Stability failure risk ratio described jointly by probability and possibility has deficiency in characterization of influence of fuzzy factors and representation of the likelihood of risk occurrence in practical engineering. In this article, credibility theory is applied into stability failure risk analysis of gravity dam. Stability of gravity dam is viewed as a hybrid event considering both fuzziness and randomness of failure criterion, design parameters and measured data. Credibility distribution function is conducted as a novel way to represent uncertainty of influence factors of gravity dam stability. And combining with Monte Carlo simulation, corresponding calculation method and procedure are proposed. Based on a dam section, a detailed application of the modeling approach on risk calculation of both dam foundation and double sliding surfaces is provided. The results show that, the present method is feasible to be applied on analysis of stability failure risk for gravity dams. The risk assessment obtained can reflect influence of both sorts of uncertainty, and is suitable as an index value.

Study on stability of rake teeth inserting soil of chain rake type mulching film recovery machine based on Adams

NASA Astrophysics Data System (ADS)

Guo, Wensong; Jian, Jianming; San, Yunlong; Lui, Rui; Li, Gang; Hou, Shulin

2017-08-01

Traditional rake type mulching film recycling machine has the problem of difficulty in unloading and packing film, poor continuity of the work. In order to solve such problems, this paper designs a kind of chain rake type mulching film recycling machine which can realize continuous raking film, collecting film, transporting film, shaking off soil, unloading film. Rake teeth is the basic part of chain rake mulching recycling machine. The stability of rake teeth's inserting soil is an important factor to ensure recovery efficiency of the plastic film recovery. By virtual prototype simulation, this paper study the influence of different factors on the stability of rake teeth inserting soil. The results are as follows: The speed of chain rake has no significant effect on the stability of rake teeth inserting soil; Reducing resistance of rake teeth in the process of working, is conducive to improve the stability of rake teeth inserting soil; Appropriate increasing elastic modulus of chain rake, is helpful to enhance the stability of rake teeth inserting soil.

Origin of Slope Failure in the Ursa Region, Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Stigall, J.; Dugan, B.

2008-12-01

We use one-dimensional fluid flow and stability models to predict the evolution of overpressure and stability conditions of IODP Expedition Sites U1322 and U1324 in the Ursa region, northern Gulf of Mexico. Simulations of homogenous mud deposited at 3 and 12 mm/yr for Sites U1322 and U1324, with permeability (k) on the order of 10-17m2 and bulk compressibility of .4 /MPa, predict overpressures up to .45MPa and 1MPa in shallow sediments (<200m below sea floor). With limit equilibrium calculations for an infinite slope, these overpressures equate to a factor of safety (FS) greater than 10 and 4.5 for a internal friction angle of 26° and a seafloor slope of 2°. This implies stability throughout the last 50,000 years. Seismic and core observations, however, document major slope failures that span the entire Ursa region. Permeability in this region is well constrained by laboratory experiments, so we investigate how pulsed (high-to-low) sedimentation rates could have created unstable conditions, FS <1. Models with periods of high sedimentation generate overpressure that create unstable conditions while maintaining the time-averaged sedimentation rates. Other factors which are not possible to simulate in one dimension, such as a complex basin geometry, also influence the conditions that caused the past failures. A two-dimensional model linking lateral flow between the sites with the interpreted geometry from seismic stratigraphy gives a better picture of the flow field and instability within the basin. Asymmetrical loading of permeable sediments could have created a lateral difference in pore pressures which would have driven lateral flow from Site U1324 to Site U1322 where overpressures are higher than our one-dimensional models suggest. We anticipate that two-dimensional models with transient sedimentation patterns will enhance our understanding of flow in marginally stable environments and triggers of slope failures in passive margin systems.

Iron Redox Cycling Drives Decomposition of Mineral-Associated C in Humid Tropical Forest Soils

NASA Astrophysics Data System (ADS)

Hall, S. J.; Mcnicol, G.; Silver, W. L.

2013-12-01

The stabilization of soil carbon (C) by reactive minerals and an inhibition of decomposition due to oxygen (O2) limitation (reducing conditions) have been proposed as drivers of the high soil C concentrations characteristic of humid tropical forests, which constitute a major terrestrial C reservoir. Here, we examined relationships between these factors and spatial patterns of C concentrations and C turnover (using radiocarbon modeling) in surface soils of the Luquillo Experimental Forest, Puerto Rico. We used concentrations of reduced iron (Fe(II)) as an index of reducing conditions given the importance of Fe reduction to anaerobic metabolism in these soils. Concentrations of Fe(II), reactive iron and aluminum (Al) minerals, interactions between Fe(II) and Al, and live fine root biomass explained most variation in C concentrations across the landscape (pseudo R2 = 0.84). Carbon increased with chelatable "poorly crystalline" Fe, in agreement with previous research, but C decreased with citrate/ascorbate extractable Fe, an index of Fe oxides susceptible to microbial reduction. We suggest that availability of Fe oxides to sustain anaerobic respiration partially offsets soil C accumulation in these ecosystems, despite the role of a subset of reactive Fe in promoting C stabilization. We estimated decomposition rates of mineral-associated C using 14C content of the heavy soil density fraction from a subset of samples. Turnover times averaged 108 years but decreased with Fe(II) concentrations. Thus, our data suggest that Fe redox cycling in soil microsites is associated with increased turnover of mineral-associated C in this fluctuating-oxygen environment, implying that the capacity of reactive metals to stabilize C may be partially contingent on O2 dynamics. Our results suggest a multifaceted role for reactive minerals in soil C cycling, emphasizing the importance of ecosystem-scale interactions among geochemical, physical, and biological factors.

Food web structure in the recently flooded Sep Reservoir as inferred from phytoplankton population dynamics and living microbial biomass.

PubMed

Tadonléké, R D; Jugnia, L B; Sime-Ngando, T; Devaux, J; Romagoux, J C

2002-01-01

Phytoplankton dynamics, bacterial standing stocks and living microbial biomass (derived from ATP measurements, 0.7-200 mm size class) were examined in 1996 in the newly flooded (1995) Sep Reservoir ('Massif Central,' France), for evidence of the importance of the microbial food web relative to the traditional food chain. Phosphate concentrations were low, N:P ratios were high, and phosphate losses converted into carbon accounted for <50% of phytoplankton biomass and production, indicating that P was limiting phytoplankton development during the study. The observed low availability of P contrasts with the high release of "directly" assimilable P often reported in newly flooded reservoirs, suggesting that factors determining nutrient dynamics in such ecosystems are complex. The phosphate availability, but also the water column stability, seemed to be among the major factors determining phytoplankton dynamics, as (i) large-size phytoplankton species were prominent during the period of increasing water column stability, whereas small-size species dominated phytoplankton assemblages during the period of decreasing stability, and (ii) a Dinobryon divergens bloom occurred during a period when inorganic P was undetectable, coinciding with the lowest values of bacterial standing stocks. Indication of grazing limitation of bacterial populations by the mixotrophic chrysophyte D. divergens (in late spring) and by other potential grazers (mainly rotifers in summer) seemed to be confirmed by the Model II or functional slopes of the bacterial vs phytoplankton regressions, which were always <0.63. Phytoplankton biomass was not correlated with phosphorus sources and its contribution was remarkably low relative to the living microbial biomass which, in contrast, was positively correlated with total phosphorus in summer. We conclude that planktonic microheterotrophs are strongly implicated in the phosphorus dynamics in the Sep Reservoir, and thus support the idea that an important amount of matter and energy flows through the "microbial loop" and food web, shortly after the flooding of a reservoir.

Genotype-property patient-phenotype relations suggest that proteome exhaustion can cause amyotrophic lateral sclerosis.

PubMed

Kepp, Kasper P

2015-01-01

Late-onset neurodegenerative diseases remain poorly understood as search continues for the perceived pathogenic protein species. Previously, variants in Superoxide Dismutase 1 (SOD1) causing Amyotrophic Lateral Sclerosis (ALS) were found to destabilize and reduce net charge, suggesting a pathogenic aggregation mechanism. This paper reports analysis of compiled patient data and experimental and computed protein properties for variants of human SOD1, a major risk factor of ALS. Both stability and reduced net charge correlate significantly with disease, with larger significance than previously observed. Using two independent methods and two data sets, a probability < 3% (t-statistical test) is found that ALS-causing mutations share average stability with all possible 2907 SOD1 mutations. Most importantly, un-weighted patient survival times correlate strongly with the misfolded/unfolded protein copy number, expressed as an exponential function of the experimental stabilities (R2 = 0.31, p = 0.002), and this phenotype is further aggravated by charge (R2 = 0.51, p = 1.8 x 10-5). This finding suggests that disease relates to the copy number of misfolded proteins. Exhaustion of motor neurons due to expensive protein turnover of misfolded protein copies is consistent with the data but can further explain e.g. the expression-dependence of SOD1 pathogenicity, the lack of identification of a molecular toxic mode, elevated SOD1 mRNA levels in sporadic ALS, bioenergetic effects and increased resting energy expenditure in ALS patients, genetic risk factors affecting RNA metabolism, and recent findings that a SOD1 mutant becomes toxic when proteasome activity is recovered after washout of a proteasome inhibitor. Proteome exhaustion is also consistent with energy-producing mitochondria accumulating at the neuromuscular junctions where ALS often initiates. If true, this exhaustion mechanism implies a complete change of focus in treatment of ALS towards actively nursing the energy state and protein turnover of the motor neurons.

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.

A Study in West German Stabilization Policy, 1956-1974. German Studies Notes. First Draft.

ERIC Educational Resources Information Center

Neumann, Manfred J. M.

The dominant driving force of past movements in West German output and prices is investigated and a review of government policy undertaken to stabilize these movements is presented. Three alternative impulse hypotheses are tested: the monetary, the fiscal, and the foreign impulse hypothesis. The major results of the tests are that: (1) monetary…

Apollo experience report. Guidance and control systems: Command and service module stabilization and control system

NASA Technical Reports Server (NTRS)

Littleton, O. P.

1974-01-01

The concepts, design, development, testing, and flight results of the command and service module stabilization and control system are discussed. The period of time covered was from November 1961 to December 1972. Also included are a functional description of the system, a discussion of the major problems, and recommendations for future programs.

Two-Year Stability and Change of Schizotypal, Borderline, Avoidant, and Obsessive-Compulsive Personality Disorders

ERIC Educational Resources Information Center

Grilo, Carlos M.; Sanislow, Charles A.; Gunderson, John G.; Pagano, Maria E.; Yen, Shirley; Zanarini, Mary C.; Shea, Tracie M.; Skodol, Andrew E.; Stout, Robert L.; Morey, Leslie C.; McGlashan, Thomas H.

2004-01-01

The authors examined the stability of schizotypal (STPD), borderline (BPD), avoidant (AVPD) and obsessive-compulsive (OCPD) personality disorders (PDs) over 2 years of prospective multiwave follow-up. Six hundred thirty-three participants recruited at 4 collaborating sites who met criteria for 1 or more of the 4 PDs or for major depressive…

Factors Influencing Obstacle Crossing Performance in Patients with Parkinson's Disease

PubMed Central

Liao, Ying-Yi; Yang, Yea-Ru; Wu, Yih-Ru; Wang, Ray-Yau

2014-01-01

Background Tripping over obstacles is the major cause of falls in community-dwelling patients with Parkinson's disease (PD). Understanding the factors associated with the obstacle crossing behavior may help to develop possible training programs for crossing performance. This study aimed to identify the relationships and important factors determining obstacle crossing performance in patients with PD. Methods Forty-two idiopathic patients with PD (Hoehn and Yahr stages I to III) participated in this study. Obstacle crossing performance was recorded by the Liberty system, a three-dimensional motion capture device. Maximal isometric strength of the lower extremity was measured by a handheld dynamometer. Dynamic balance and sensory integration ability were assessed using the Balance Master system. Movement velocity (MV), maximal excursion (ME), and directional control (DC) were obtained during the limits of stability test to quantify dynamic balance. The sum of sensory organization test (SOT) scores was used to quantify sensory organization ability. Results Both crossing stride length and stride velocity correlated significantly with lower extremity muscle strength, dynamic balance control (forward and sideward), and sum of SOT scores. From the regression model, forward DC and ankle dorsiflexor strength were identified as two major determinants for crossing performance (R2 = .37 to.41 for the crossing stride length, R2 = .43 to.44 for the crossing stride velocity). Conclusions Lower extremity muscle strength, dynamic balance control and sensory integration ability significantly influence obstacle crossing performance. We suggest an emphasis on muscle strengthening exercises (especially ankle dorsiflexors), balance training (especially forward DC), and sensory integration training to improve obstacle crossing performance in patients with PD. PMID:24454723

Influence of gait speed on stability: recovery from anterior slips and compensatory stepping.

PubMed

Bhatt, T; Wening, J D; Pai, Y-C

2005-02-01

Falls precipitated by slipping are a major health concern, with the majority of all slip-related falls occurring during gait. Recent evidence shows that a faster and/or more anteriorly positioned center of mass (COM) is more stable against backward balance loss, and that compensatory stepping is the key to recovering stability upon balance loss. The purposes of this paper were to determine whether walking speed affected gait stability for backward balance loss at slip onset and touchdown of compensatory stepping, and whether compensatory stepping response resembled the regular gait pattern. Forty-seven young subjects were slipped unexpectedly either at a self-selected fast, natural or slow speed. Speed-related differences in stability at slip onset and touchdown of the subsequent compensatory step were analyzed using the COM position-velocity state. The results indicate that gait speed highly correlated with stability against backward balance loss at slip onset. The low COM velocity of the slow group was not sufficiently compensated for by a more anteriorly positioned COM associated with a shorter step length at slip onset. At touchdown of the compensatory step, the speed-related differences in stability diminished, due to the continued advantage of anterior COM positioning from a short compensatory step retained by the slow group, coupled with an increase in COM velocity. Compensatory step length and relative COM position altered as a function of gait speed, indicating the motor program for gait regulation may play a role in modulating the compensatory step.

Clinical Use of Mood Stabilizers With Antidepressants in Asia: Report From the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) Projects in 2004 and 2013.

PubMed

Rajaratnam, Kamini; Xiang, Yu-Tao; Tripathi, Adarsh; Chiu, Helen F K; Si, Tian-Mei; Chee, Kok-Yoon; Avasthi, Ajit; Grover, Sandeep; Chong, Mian-Yoon; Kuga, Hironori; Kanba, Shigenobu; He, Yan-Ling; Lee, Min-Soo; Yang, Shu-Yu; Udomratn, Pichet; Kallivayalil, Roy A; Tanra, Andi J; Maramis, Margarita M; Shen, Winston W; Sartorius, Norman; Kua, Ee-Heok; Tan, Chay-Hoon; Mahendran, Rathi; Shinfuku, Naotaka; Sum, Min Yi; Baldessarini, Ross J; Sim, Kang

2017-04-01

As most reports concerning treatment with combinations of mood stabilizer (MS) with antidepressant (AD) drugs are based in the West, we surveyed characteristics of such cotreatment in 42 sites caring for the mentally ill in 10 Asian countries. This cross-sectional, pharmacoepidemiologic study used 2004 and 2013 data from the REAP-AD (Research Study on Asian Psychotropic Prescription Patterns for Antidepressants) to evaluate the rates and doses of MSs given with ADs and associated factors in 4164 psychiatric patients, using standard bivariate methods followed by multivariable logistic regression modeling. Use of MS + AD increased by 104% (5.5% to 11.2%) between 2004 and 2013 and was much more associated with diagnosis of bipolar disorder than major depression or anxiety disorder, as well as with hospitalization > outpatient care, psychiatric > general-medical programs, and young age (all P < 0.001), but not with country, sex, or AD dose. The findings provide a broad picture of contemporary use of MSs with ADs in Asia, support predictions that such treatment increased in recent years, and was associated with diagnosis of bipolar disorder, treatment in inpatient and psychiatric settings, and younger age.

Impact of oxidation on protein therapeutics: Conformational dynamics of intact and oxidized acid-β-glucocerebrosidase at near-physiological pH

PubMed Central

Bobst, Cedric E; Thomas, John J; Salinas, Paul A; Savickas, Philip; Kaltashov, Igor A

2010-01-01

The solution dynamics of an enzyme acid-β-glucocerebrosidase (GCase) probed at a physiologically relevant (lysosomal) pH by hydrogen/deuterium exchange mass spectrometry (HDX-MS) reveals very uneven distribution of backbone amide protection across the polypeptide chain. Highly mobile segments are observed even within the catalytic cavity alongside highly protective segments, highlighting the importance of the balance between conformational stability and flexibility for enzymatic activity. Forced oxidation of GCase that resulted in a 40–60% reduction in in vitro biological activity affects the stability of some key structural elements within the catalytic site. These changes in dynamics occur on a longer time scale that is irrelevant for catalysis, effectively ruling out loss of structure in the catalytic site as a major factor contributing to the reduction of the catalytic activity. Oxidation also leads to noticeable destabilization of conformation in remote protein segments on a much larger scale, which is likely to increase the aggregation propensity of GCase and affect its bioavailability. Therefore, it appears that oxidation exerts its negative impact on the biological activity of GCase indirectly, primarily through accelerated aggregation and impaired trafficking. PMID:20945356

Effect of pH and interaction between egg white protein and hydroxypropymethylcellulose in bulk aqueous medium on foaming properties.

PubMed

Sadahira, Mitie S; Lopes, Fernanda C Rezende; Rodrigues, Maria I; Yamada, Aureo T; Cunha, Rosiane L; Netto, Flavia M

2015-07-10

Egg white protein (EW) is used as surface-active ingredient in aerated food and hydroxypropylmethylcellulose (HPMC) is a polysaccharide that behaves as a surfactant. This study aimed at investigating the effects of process parameters biopolymer concentration (2.0-5.0%, w/w), EW:HPMC ratio (2:1-18:1), pH (3.0-6.0), and the influence of biopolymers' behavior in aqueous solution at different pH on the foaming properties (overrun, drainage, and bubble growth rate). Process parameters had effect on foaming properties. The pH was the major factor influencing the type of EW/HPMC interaction and affected the foaming properties of biopolymer mixture. At pH 3.0, EW and HPMC showed thermodynamic compatibility leading to better foaming properties, higher foaming capacity, and stability than without HPMC addition whereas at pH 4.5 and 6.0, EW and HPMC are incompatible that causes lower stability concerning the disproportionation comparing to foam without HPMC. At pH between 3.0 and 4.5, HPMC improves foaming properties of aerated products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of unsteady aerodynamics on driving dynamics of passenger cars

NASA Astrophysics Data System (ADS)

Huemer, Jakob; Stickel, Thomas; Sagan, Erich; Schwarz, Martin; Wall, Wolfgang A.

2014-11-01

Recent approaches towards numerical investigations with computational fluid dynamics methods on unsteady aerodynamic loads of passenger cars identified major differences compared with steady-state aerodynamic excitations. Furthermore, innovative vehicle concepts such as electric-vehicles or hybrid drives further challenge the basic layout of passenger cars. Therefore, the relevance of unsteady aerodynamic loads on cross-wind stability of changing basic vehicle architectures should be analysed. In order to assure and improve handling and ride characteristics at high velocity of the actual range of vehicle layouts, the influence of unsteady excitations on the vehicle response was investigated. For this purpose, a simulation of the vehicle dynamics through multi-body simulation was used. The impact of certain unsteady aerodynamic load characteristics on the vehicle response was quantified and key factors were identified. Through a series of driving simulator tests, the identified differences in the vehicle response were evaluated regarding their significance on the subjective driver perception of cross-wind stability. Relevant criteria for the subjective driver assessment of the vehicle response were identified. As a consequence, a design method for the basic layout of passenger cars and chassis towards unsteady aerodynamic excitations was defined.

Compressional Alfven Eigenmode Similarity Study

NASA Astrophysics Data System (ADS)

Heidbrink, W. W.; Fredrickson, E. D.; Gorelenkov, N. N.; Rhodes, T. L.

2004-11-01

NSTX and DIII-D are nearly ideal for Alfven eigenmode (AE) similarity experiments, having similar neutral beams, fast-ion to Alfven speed v_f/v_A, fast-ion pressure, and shape of the plasma, but with a factor of 2 difference in the major radius. Toroidicity-induced AE with ˜100 kHz frequencies were compared in an earlier study [1]; this paper focuses on higher frequency AE with f ˜ 1 MHz. Compressional AE (CAE) on NSTX have a polarization, dependence on the fast-ion distribution function, frequency scaling, and low-frequency limit that are qualitatively consistent with CAE theory [2]. Global AE (GAE) are also observed. On DIII-D, coherent modes in this frequency range are observed during low-field (0.6 T) similarity experiments. Experiments will compare the CAE stability limits on DIII-D with the NSTX stability limits, with the aim of determining if CAE will be excited by alphas in a reactor. Predicted differences in the frequency splitting Δ f between excited modes will also be used. \\vspace0.25em [1] W.W. Heidbrink, et al., Plasmas Phys. Control. Fusion 45, 983 (2003). [2] E.D. Fredrickson, et al., Princeton Plasma Physics Laboratory Report PPPL-3955 (2004).

Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes

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

Zou, Chen; Huang, Chun-Ying; Sanehira, Erin M.

Recently, all-inorganic perovskites such as CsPbBr3 and CsPbI3, have emerged as promising materials for light-emitting applications. While encouraging performance has been demonstrated, the stability issue of the red-emitting CsPbI3 is still a major concern due to its small tolerance factor. Here we report a highly stable CsPbI3 quantum dot LED with red emission fabricated using an improved purification approach. The device achieved decent external quantum efficiency (EQE) of 0.21 % at a bias of 6 V and outstanding operational stability, with a L70 lifetime (EL intensity decreases to 70% of starting value) of 16 h and 1.5 h under amore » constant driving voltage of 5 V and 6 V (maximum EQE operation) respectively. Furthermore, the device can work under a higher voltage of 7 V (maximum luminance operation) and retain 50% of its initial EL intensity after 500 s. These findings demonstrate the promise of CsPbI3 quantum dots for stable red LEDs, and suggest the feasibility for electrically pumped perovskite lasers with further device optimizations.« less

Long-term lunar stations: Some ecological considerations

NASA Technical Reports Server (NTRS)

Maguire, Bassett, Jr.; Scott, Kelly W.

1992-01-01

A major factor for long-term success of a lunar station is the ability to keep an agroecosystem functioning at a desirable, stable steady-state with ecological stability and reliability. Design for a long-lived extraterrestrial manned station must take into account interactions among its subsystems to insure that overall functionality is enhanced (or at least not compromised). Physical isolation of feed production, human living areas, recycling, and other systems may be straightforward, however, microbiological isolation will be very difficult. While it is possible to eliminate plant-associated microbiological communities by growing the plants asepticallly, it is not practical to keep plants germ-free on a large scale if humans are working with them. Ecological theory strongly suggests that some kinds of communities or organisms effectively increase the stability of ecosystems and will protect the plants from potential pathogens. A carefully designed and maintained (lunar-derived) soil can provide a variety of habitats for effective microbial buffers while adding structure to the agroecosystem. A soil can also increase ecosystem reliability through buffering otherwise large element and compound fluctuations (of nutrients, wastes, etc.) as well as buffering temperature level and atmosphere composition. We are doing experiments in ecological dynamics and attempting to extend the relevant theories.

Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes

DOE PAGES

Zou, Chen; Huang, Chun-Ying; Sanehira, Erin M.; ...

2017-09-11

Recently, all-inorganic perovskites such as CsPbBr3 and CsPbI3, have emerged as promising materials for light-emitting applications. While encouraging performance has been demonstrated, the stability issue of the red-emitting CsPbI3 is still a major concern due to its small tolerance factor. Here we report a highly stable CsPbI3 quantum dot LED with red emission fabricated using an improved purification approach. The device achieved decent external quantum efficiency (EQE) of 0.21 % at a bias of 6 V and outstanding operational stability, with a L70 lifetime (EL intensity decreases to 70% of starting value) of 16 h and 1.5 h under amore » constant driving voltage of 5 V and 6 V (maximum EQE operation) respectively. Furthermore, the device can work under a higher voltage of 7 V (maximum luminance operation) and retain 50% of its initial EL intensity after 500 s. These findings demonstrate the promise of CsPbI3 quantum dots for stable red LEDs, and suggest the feasibility for electrically pumped perovskite lasers with further device optimizations.« less

Hyaluronic Acid in Vascular and Immune Homeostasis during Normal Pregnancy and Preeclampsia

PubMed Central

Ziganshina, M. M.; Pavlovich, S. V.; Bovin, N. V.; Sukhikh, G. T.

2016-01-01

Preeclampsia (PE) is a multisystem pathologic state that clinically manifests itself after the 20th week of pregnancy. It is characterized by high maternal and perinatal morbidity and mortality. According to modern concepts, the impairment of trophoblast invasion into maternal spiral arteries, leading to the development of ischemia in placenta, is considered to be the major pathogenetic factor of PE development. Ischemic lesions initiate the development of a systemic inflammatory response (SIR) and endothelial dysfunction, which is the main cause of the multiple organ failure in PE. Some data has appear indicating the importance of a glycans-forming endothelial glycocalyx and extracellular matrix (ECM) for placenta morphogenesis, as well as their role in the regulation of vascular permeability and vascular tone in hypertension disorders and, in particular, PE. Since intact glycocalyx and ECM are considered to be the major factors that maintain the physiological vascular tone and adequate intercellular interactions, their value in PE pathogenesis is underestimated. This review is focused on hyaluronic acid (HA) as the key glycan providing the organization and stabilization of the ECM and glycocalyx, its distribution in tissues in the case of presence or absence of placental pathology, as well as on the regulatory function of hyaluronic acids of various molecular weights in different physiological and pathophysiological processes. The summarized data will provide a better understanding of the PE pathogenesis, with the main focus on glycopathology. PMID:27795844

Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

PubMed

Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

2016-01-01

Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to maintain good drinking water microbial quality up to consumer's tap. A new definition and methodological approach for biological stability is proposed.

Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

PubMed Central

Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

2016-01-01

Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to maintain good drinking water microbial quality up to consumer’s tap. A new definition and methodological approach for biological stability is proposed. PMID:26870010

The study on length and diameter ratio of nail as preliminary design for slope stabilization

NASA Astrophysics Data System (ADS)

Gunawan, Indra; Silmi Surjandari, Niken; Muslih Purwana, Yusep

2017-11-01

Soil nailing technology has been widely applied in practice for reinforced slope. The number of studies for the effective design of nail-reinforced slopes has also increased. However, most of the previous study was focused on a safety factor of the slope; the ratio of length and diameter itself has likely never been studied before. The aim of this study is to relate the length and diameter ratio of the nail with the safety factor of the 20 m height of sand slope in the various angle of friction and steepness of the slope. Simplified Bishop method was utilized to analyze the safety factor of the slope. This study is using data simulation to calculate the safety factor of the slope with soil nailing reinforcement. The results indicate that safety factor of slope stability increases with the increase of length and diameter ratio of the nail. At any angle of friction and steepness of the slope, certain effective length and diameter ratio was obtain. These results may be considered as a preliminary design for slope stabilization.

Reinforcing mechanism of anchors in slopes: a numerical comparison of results of LEM and FEM

NASA Astrophysics Data System (ADS)

Cai, Fei; Ugai, Keizo

2003-06-01

This paper reports the limitation of the conventional Bishop's simplified method to calculate the safety factor of slopes stabilized with anchors, and proposes a new approach to considering the reinforcing effect of anchors on the safety factor. The reinforcing effect of anchors can be explained using an additional shearing resistance on the slip surface. A three-dimensional shear strength reduction finite element method (SSRFEM), where soil-anchor interactions were simulated by three-dimensional zero-thickness elasto-plastic interface elements, was used to calculate the safety factor of slopes stabilized with anchors to verify the reinforcing mechanism of anchors. The results of SSRFEM were compared with those of the conventional and proposed approaches for Bishop's simplified method for various orientations, positions, and spacings of anchors, and shear strengths of soil-grouted body interfaces. For the safety factor, the proposed approach compared better with SSRFEM than the conventional approach. The additional shearing resistance can explain the influence of the orientation, position, and spacing of anchors, and the shear strength of soil-grouted body interfaces on the safety factor of slopes stabilized with anchors.

Plant diversity drives soil microbial biomass carbon in grasslands irrespective of global environmental change factors.

PubMed

Thakur, Madhav Prakash; Milcu, Alexandru; Manning, Pete; Niklaus, Pascal A; Roscher, Christiane; Power, Sally; Reich, Peter B; Scheu, Stefan; Tilman, David; Ai, Fuxun; Guo, Hongyan; Ji, Rong; Pierce, Sarah; Ramirez, Nathaly Guerrero; Richter, Annabell Nicola; Steinauer, Katja; Strecker, Tanja; Vogel, Anja; Eisenhauer, Nico

2015-11-01

Soil microbial biomass is a key determinant of carbon dynamics in the soil. Several studies have shown that soil microbial biomass significantly increases with plant species diversity, but it remains unclear whether plant species diversity can also stabilize soil microbial biomass in a changing environment. This question is particularly relevant as many global environmental change (GEC) factors, such as drought and nutrient enrichment, have been shown to reduce soil microbial biomass. Experiments with orthogonal manipulations of plant diversity and GEC factors can provide insights whether plant diversity can attenuate such detrimental effects on soil microbial biomass. Here, we present the analysis of 12 different studies with 14 unique orthogonal plant diversity × GEC manipulations in grasslands, where plant diversity and at least one GEC factor (elevated CO2 , nutrient enrichment, drought, earthworm presence, or warming) were manipulated. Our results show that higher plant diversity significantly enhances soil microbial biomass with the strongest effects in long-term field experiments. In contrast, GEC factors had inconsistent effects with only drought having a significant negative effect. Importantly, we report consistent non-significant effects for all 14 interactions between plant diversity and GEC factors, which indicates a limited potential of plant diversity to attenuate the effects of GEC factors on soil microbial biomass. We highlight that plant diversity is a major determinant of soil microbial biomass in experimental grasslands that can influence soil carbon dynamics irrespective of GEC. © 2015 John Wiley & Sons Ltd.

From Negative to Positive Stability: How the Syrian Refugee Crisis Can Improve Jordan’s Outlook

DTIC Science & Technology

2015-01-01

Syrian Refugees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Forecast: The Impact of Syrian Refugees on Jordan’s Economic Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22...Syrians find economic stability , they will be less vulnerable to the loss of aid, and therefore less likely to present a drain on Jordanian society...with Syrian refugees, and presents a forecast of Syrian refugee impacts on Jordan’s economy and such economic stability factors as unem- ployment and

Effect of inertia properties on attitude stability of nonrigid spin-stabilized spacecraft

NASA Technical Reports Server (NTRS)

Lang, W. E.; Young, J. P.

1974-01-01

The phenomenon of energy dissipation in spinning spacecraft is discussed with particular reference to its dependence on spacecraft inertia properties. Specific dissipation mechanisms are identified. The effect of external environmental factors on spin stability is also discussed. Generalized curves are presented relating system stability to the principal inertia ratio for various forms of energy dissipation. Dual-spin systems and the effect of lateral inertia asymmetry are also reviewed.

pH Modulates the Binding of EGR1 Transcription Factor to DNA

PubMed Central

Mikles, David C.; Bhat, Vikas; Schuchardt, Brett J.; Deegan, Brian J.; Seldeen, Kenneth L.; McDonald, Caleb B.; Farooq, Amjad

2013-01-01

EGR1 transcription factor orchestrates a plethora of signaling cascades involved in cellular homeostasis and its down-regulation has been implicated in the development of prostate cancer. Herein, using a battery of biophysical tools, we show that the binding of EGR1 to DNA is tightly regulated by solution pH. Importantly, the binding affinity undergoes an enhancement of more than an order of magnitude with increasing pH from 5 to 8, implying that the deprotonation of an ionizable residue accounts for such behavior. This ionizable residue is identified as H382 by virtue of the fact that its substitution to non-ionizable residues abolishes pH-dependence of the binding of EGR1 to DNA. Notably, H382 inserts into the major groove of DNA and stabilizes the EGR1-DNA interaction via both hydrogen bonding and van der Waals contacts. Remarkably, H382 is predominantly conserved across other members of EGR1 family, implying that histidine protonation-deprotonation may serve as a molecular switch for modulating protein-DNA interactions central to this family of transcription factors. Collectively, our findings uncover an unexpected but a key step in the molecular recognition of EGR1 family of transcription factors and suggest that they may act as sensors of pH within the intracellular environment. PMID:23718776

PIF3 is a negative regulator of the CBF pathway and freezing tolerance in Arabidopsis

PubMed Central

Jiang, Bochen; Shi, Yiting; Zhang, Xiaoyan; Xin, Xiaoyun; Qi, Lijuan; Guo, Hongwei; Li, Jigang; Yang, Shuhua

2017-01-01

Light and temperature are major environmental factors that coordinately control plant growth and survival. However, how plants integrate light and temperature signals to better adapt to environmental stresses is poorly understood. PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), a key transcription factor repressing photomorphogenesis, has been shown to play a pivotal role in mediating plants’ responses to various environmental signals. In this study, we found that PIF3 functions as a negative regulator of Arabidopsis freezing tolerance by directly binding to the promoters of C-REPEAT BINDING FACTOR (CBF) genes to down-regulate their expression. In addition, two F-box proteins, EIN3-BINDING F-BOX 1 (EBF1) and EBF2, directly target PIF3 for 26S proteasome-mediated degradation. Consistently, ebf1 and ebf2 mutants were more sensitive to freezing than were the wild type, and the pif3 mutation suppressed the freezing-sensitive phenotype of ebf1. Furthermore, cold treatment promoted the degradation of EBF1 and EBF2, leading to increased stability of the PIF3 protein and reduced expression of the CBF genes. Together, our study uncovers an important role of PIF3 in Arabidopsis freezing tolerance by negatively regulating the expression of genes in the CBF pathway. PMID:28739888

Core stability: implications for dance injuries.

PubMed

Rickman, Ashley M; Ambegaonkar, Jatin P; Cortes, Nelson

2012-09-01

Dancers experience a high incidence of injury due to the extreme physical demands of dancing. The majority of dance injuries are chronic in nature and occur in the lower extremities and low back. Researchers have indicated decreased core stability (CS) as a risk factor for these injuries. Although decreased CS is suggested to negatively affect lower extremity joint motion and lumbar control during activity, this relationship has not been extensively discussed in previous dance literature. Understanding the relationship between CS and injury risk is important to help reduce dance injury incidence and improve performance. The purposes of this review were to discuss: 1. the core and components of CS, 2. the relationship between CS and injury, 3. CS assessment techniques, and 4. future dance CS research areas. CS is the integration of passive (non-contractile), active (contractile), and neural structures to minimize the effects of external forces and maintain stability. CS is maintained by a combination of muscle power, strength, endurance, and sensory-motor control of the lumbopelvic-hip complex. CS assessments include measuring muscle strength and power using maximal voluntary isometric and isokinetic contractions and measuring endurance using the Biering-Sorensen, plank, and lateral plank tests. Measuring sensory-motor control requires specialized equipment (e.g., balance platforms). Overall, limited research has comprehensively examined all components of CS together and their relationships to injury. Rather, previous researchers have separately examined core power, strength, endurance, or sensory-motor control. Future researchers should explore the multifactorial role of CS in reducing injury risk and enhancing performance in dancers.

The stability of a novel weakly alkaline slurry of copper interconnection CMPfor GLSI

NASA Astrophysics Data System (ADS)

Yao, Caihong; Wang, Chenwei; Niu, Xinhuan; Wang, Yan; Tian, Shengjun; Jiang, Zichao; Liu, Yuling

2018-02-01

Chemical mechanical polishing (CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency, low surface roughness. The effect of slurry components such as abrasive (colloidal silica), complexing agent (glycine), inhibitor (BTA) and oxidizing agent (H2O2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper. First, the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward. Then 1 wt% colloidal silica, 2.5 wt% glycine, 200 ppm BTA, 20 mL/L H2O2 had been selected as the appropriate concentration to prepare copper slurry, and using such slurry the copper blanket wafer was polished. From the variations of copper removal rate, root-mean square roughness (Sq) value with the setting time, it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days, which satisfies the requirement of microelectronics further development. Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Professional Degree Teaching Case Foundation of Hebei Province, China (No. KCJSZ2017008), the Natural Science Foundation of Hebei Province, China (No. F2015202267), and the Natural Science Foundation of Tianjin, China (No. 16JCYBJC16100).

WW Domains of the Yes-Kinase-Associated-Protein (YAP) Transcriptional Regulator Behave as Independent Units with Different Binding Preferences for PPxY Motif-Containing Ligands

PubMed Central

Iglesias-Bexiga, Manuel; Castillo, Francisco; Cobos, Eva S.; Oka, Tsutomu; Sudol, Marius; Luque, Irene

2015-01-01

YAP is a WW domain-containing effector of the Hippo tumor suppressor pathway, and the object of heightened interest as a potent oncogene and stemness factor. YAP has two major isoforms that differ in the number of WW domains they harbor. Elucidating the degree of co-operation between these WW domains is important for a full understanding of the molecular function of YAP. We present here a detailed biophysical study of the structural stability and binding properties of the two YAP WW domains aimed at investigating the relationship between both domains in terms of structural stability and partner recognition. We have carried out a calorimetric study of the structural stability of the two YAP WW domains, both isolated and in a tandem configuration, and their interaction with a set of functionally relevant ligands derived from PTCH1 and LATS kinases. We find that the two YAP WW domains behave as independent units with different binding preferences, suggesting that the presence of the second WW domain might contribute to modulate target recognition between the two YAP isoforms. Analysis of structural models and phage-display studies indicate that electrostatic interactions play a critical role in binding specificity. Together, these results are relevant to understand of YAP function and open the door to the design of highly specific ligands of interest to delineate the functional role of each WW domain in YAP signaling. PMID:25607641

Diagnostic Utility of Craving in Predicting Nicotine Dependence: Impact of Craving Content and Item Stability

PubMed Central

2013-01-01

Introduction: Craving is useful in the diagnosis of drug dependence, but it is unclear how various items used to assess craving might influence the diagnostic performance of craving measures. This study determined the diagnostic performance of individual items and item subgroups of the 32-item Questionnaire on Smoking Urges (QSU) as a function of item wording, level of craving intensity, and item stability. Methods: Nondaily and daily smokers (n = 222) completed the QSU on 6 separate occasions, and item responses were averaged across the administrations. Nicotine dependence was assessed with the Wisconsin Inventory of Smoking Dependence Motives. The discriminative performance of the QSU items was evaluated with receiver-operating characteristic curves and area under the curve statistics. Results: Although each of the QSU items and selected subgroups of items significantly discriminated dependent from nondependent smokers, certain item subgroups outperformed others. There was no difference in discriminative performance between use of the specific terms urge and crave or between items assessing intention to smoke relative to those assessing desire to smoke, but there were significant differences in the two major factors represented on the QSU and in craving items reflecting more intense relative to less intense craving. Stability of the item scores was strongly related to the discriminative performance of craving. Conclusions: Items indexing stable, high-intensity aspects of craving that reflect the negative reinforcing effects of smoking will likely be most useful for diagnostic purposes. Future directions and implications are discussed. PMID:23817585

Diagnostic utility of craving in predicting nicotine dependence: impact of craving content and item stability.

PubMed

Germeroth, Lisa J; Wray, Jennifer M; Gass, Julie C; Tiffany, Stephen T

2013-12-01

Craving is useful in the diagnosis of drug dependence, but it is unclear how various items used to assess craving might influence the diagnostic performance of craving measures. This study determined the diagnostic performance of individual items and item subgroups of the 32-item Questionnaire on Smoking Urges (QSU) as a function of item wording, level of craving intensity, and item stability. Nondaily and daily smokers (n = 222) completed the QSU on 6 separate occasions, and item responses were averaged across the administrations. Nicotine dependence was assessed with the Wisconsin Inventory of Smoking Dependence Motives. The discriminative performance of the QSU items was evaluated with receiver-operating characteristic curves and area under the curve statistics. Although each of the QSU items and selected subgroups of items significantly discriminated dependent from nondependent smokers, certain item subgroups outperformed others. There was no difference in discriminative performance between use of the specific terms urge and crave or between items assessing intention to smoke relative to those assessing desire to smoke, but there were significant differences in the two major factors represented on the QSU and in craving items reflecting more intense relative to less intense craving. Stability of the item scores was strongly related to the discriminative performance of craving. Items indexing stable, high-intensity aspects of craving that reflect the negative reinforcing effects of smoking will likely be most useful for diagnostic purposes. Future directions and implications are discussed.

The polymeric stability of the Escherichia coli F4 (K88) fimbriae enhances its mucosal immunogenicity following oral immunization.

PubMed

Verdonck, Frank; Joensuu, Jussi Joonas; Stuyven, Edith; De Meyer, Julie; Muilu, Mikko; Pirhonen, Minna; Goddeeris, Bruno Maria; Mast, Jan; Niklander-Teeri, Viola; Cox, Eric

2008-10-23

Only a few vaccines are commercially available against intestinal infections since the induction of a protective intestinal immune response is difficult to achieve. For instance, oral administration of most proteins results in oral tolerance instead of an antigen-specific immune response. We have shown before that as a result of oral immunization of piglets with F4 fimbriae purified from pathogenic enterotoxigenic Escherichia coli (ETEC), the fimbriae bind to the F4 receptor (F4R) in the intestine and induce a protective F4-specific immune response. F4 fimbriae are very stable polymeric structures composed of some minor subunits and a major subunit FaeG that is also the fimbrial adhesin. In the present study, the mutagenesis experiments identified FaeG amino acids 97 (N to K) and 201 (I to V) as determinants for F4 polymeric stability. The interaction between the FaeG subunits in mutant F4 fimbriae is reduced but both mutant and wild type fimbriae behaved identically in F4R binding and showed equal stability in the gastro-intestinal lumen. Oral immunization experiments indicated that a higher degree of polymerisation of the fimbriae in the intestine was correlated with a better F4-specific mucosal immunogenicity. These data suggest that the mucosal immunogenicity of soluble virulence factors can be increased by the construction of stable polymeric structures and therefore help in the development of effective mucosal vaccines.

Factorized Runge-Kutta-Chebyshev Methods

NASA Astrophysics Data System (ADS)

O'Sullivan, Stephen

2017-05-01

The second-order extended stability Factorized Runge-Kutta-Chebyshev (FRKC2) explicit schemes for the integration of large systems of PDEs with diffusive terms are presented. The schemes are simple to implement through ordered sequences of forward Euler steps with complex stepsizes, and easily parallelised for large scale problems on distributed architectures. Preserving 7 digits for accuracy at 16 digit precision, the schemes are theoretically capable of maintaining internal stability for acceleration factors in excess of 6000 with respect to standard explicit Runge-Kutta methods. The extent of the stability domain is approximately the same as that of RKC schemes, and a third longer than in the case of RKL2 schemes. Extension of FRKC methods to fourth-order, by both complex splitting and Butcher composition techniques, is also discussed. A publicly available implementation of FRKC2 schemes may be obtained from maths.dit.ie/frkc

Smad Ubiquitylation Regulatory Factor 1/2 (Smurf1/2) Promotes p53 Degradation by Stabilizing the E3 Ligase MDM2*

PubMed Central

Nie, Jing; Xie, Ping; Liu, Lin; Xing, Guichun; Chang, Zhijie; Yin, Yuxin; Tian, Chunyan; He, Fuchu; Zhang, Lingqiang

2010-01-01

The tumor suppressor p53 protein is tightly regulated by a ubiquitin-proteasomal degradation mechanism. Several E3 ubiquitin ligases, including MDM2 (mouse double minute 2), have been reported to play an essential role in the regulation of p53 stability. However, it remains unclear how the activity of these E3 ligases is regulated. Here, we show that the HECT-type E3 ligase Smurf1/2 (Smad ubiquitylation regulatory factor 1/2) promotes p53 degradation by enhancing the activity of the E3 ligase MDM2. We provide evidence that the role of Smurf1/2 on the p53 stability is not dependent on the E3 activity of Smurf1/2 but rather is dependent on the activity of MDM2. We find that Smurf1/2 stabilizes MDM2 by enhancing the heterodimerization of MDM2 with MDMX, during which Smurf1/2 interacts with MDM2 and MDMX. We finally provide evidence that Smurf1/2 regulates apoptosis through p53. To our knowledge, this is the first report to demonstrate that Smurf1/2 functions as a factor to stabilize MDM2 protein rather than as a direct E3 ligase in regulation of p53 degradation. PMID:20484049

Design and synthesis of a novel multifunctional stabilizer for highly stable uc(dl)-tetrahydropalmatine nanosuspensions and in vitro study

NASA Astrophysics Data System (ADS)

Yan, Beibei; Wang, Yancai; Wang, Lulu; Zhou, Yuqi; Shang, Xueyun; Zhao, Juan; Liu, Yangyang; Du, Juan

2018-05-01

The present study aimed to prepare stable uc(dl)-tetrahydropalmatine (uc(dl)-THP) nanosuspensions of optimized formulation with PEGylated chitosan as a multifunctional stabilizer using the antisolvent precipitation method. A central composite design project of three factors and five-level full factorial (53) was applied to design the experimental program, and response surface methodology analysis was used to optimize the experimental conditions. The effects of critical influencing factors such as PEGylated chitosan concentration, operational temperature, and ultrasonic energy on particle size and zeta potential were investigated. Under the optimization nanosuspension formulation, the particle size was 269 nm and zeta potential was at 37.4 mV. Also, the uc(dl)-THP nanosuspensions maintained good physical stability after 2 months, indicating the potential ability of the multifunctional stabilizer for stable nanosuspension formulation. Hence, the present findings indicated that PEGylated chitosan could be used as the ideal stabilizer to form a physically stable nanosuspension formulation.

Orthogonal optimization of a water hydraulic pilot-operated pressure-reducing valve

NASA Astrophysics Data System (ADS)

Mao, Xuyao; Wu, Chao; Li, Bin; Wu, Di

2017-12-01

In order to optimize the comprehensive characteristics of a water hydraulic pilot-operated pressure-reducing valve, numerical orthogonal experimental design was adopted. Six parameters of the valve, containing diameters of damping plugs, volume of spring chamber, half cone angle of main spool, half cone angle of pilot spool, mass of main spool and diameter of main spool, were selected as the orthogonal factors, and each factor has five different levels. An index of flowrate stability, pressure stability and pressure overstrike stability (iFPOS) was used to judge the merit of each orthogonal attempt. Embedded orthogonal process turned up and a final optimal combination of these parameters was obtained after totally 50 numerical orthogonal experiments. iFPOS could be low to a fairly low value which meant that the valve could have much better stabilities. During the optimization, it was also found the diameters of damping plugs and main spool played important roles in stability characteristics of the valve.

Physical Analysis Work for Slope Stability at Shah Alam, Selangor

NASA Astrophysics Data System (ADS)

Ishak, M. F.; Zaini, M. S. I.

2018-04-01

Slope stability analysis is performed to assess the equilibrium conditions and the safe design of a human-made or natural slope to find the endangered areas. Investigation of potential failure and determination of the slope sensitivity with regard to safety, reliability and economics were parts of this study. Ground anchor is designed to support a structure in this study. Ground anchor were implemented at the Mechanically Stabilized Earth (MSE) wall along Anak Persiaran Jubli Perak to overcome the further cracking of pavement parking, concrete deck and building of the Apartments. A result from the laboratory testing of soil sample such as index test and shear strength test were applied to the Slope/W software with regard to the ground anchors that were implemented. The ground anchors were implemented to increase the value of the factor of safety (FOS) of the MSE Wall. The value of the factor of safety (FOS) before implementing the ground anchor was 0.800 and after the ground anchor was implemented the value increase to 1.555. The increase percentage of factor of safety by implementing on stability of slope was 94.38%.

An application of the LC-LSTM framework to the self-esteem instability case.

PubMed

Alessandri, Guido; Vecchione, Michele; Donnellan, Brent M; Tisak, John

2013-10-01

The present research evaluates the stability of self-esteem as assessed by a daily version of the Rosenberg (Society and the adolescent self-image, Princeton University Press, Princeton, 1965) general self-esteem scale (RGSE). The scale was administered to 391 undergraduates for five consecutive days. The longitudinal data were analyzed using the integrated LC-LSTM framework that allowed us to evaluate: (1) the measurement invariance of the RGSE, (2) its stability and change across the 5-day assessment period, (3) the amount of variance attributable to stable and transitory latent factors, and (4) the criterion-related validity of these factors. Results provided evidence for measurement invariance, mean-level stability, and rank-order stability of daily self-esteem. Latent state-trait analyses revealed that variances in scores of the RGSE can be decomposed into six components: stable self-esteem (40 %), ephemeral (or temporal-state) variance (36 %), stable negative method variance (9 %), stable positive method variance (4 %), specific variance (1 %) and random error variance (10 %). Moreover, latent factors associated with daily self-esteem were associated with measures of depression, implicit self-esteem, and grade point average.

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

Luke Chen; Hsu-Cheng Chang

An air pollutant (CO) distribution in a typical street canyon is simulated to evaluate pedestrian exposure. In this study, we consider factors those may affect the pollutant distribution in a typical street canyon. The considered factors include aspect ratio of a street canyon, atmospheric stability, traffic load and turbulent buoyancy effect. A two-dimensional domain that includes suburban roughness and urban street canyon is considered. The factors such as atmospheric stability, traffic load and turbulent buoyancy are imposed through the associated boundary conditions. With numerical simulation, the critical aspect ration of a street canyon the includes two vortices and results inmore » pollutant accumulation are found. The buoyant effect is found to raise the same pollutant concentration up to the position higher than the results come out from the case without buoyancy. The pedestrian exposure to the street air pollutant under various traffic loads and atmospheric stability are evaluated. This study conclude that the local building regulations that specify the building height/street width ratio will not cause significant pedestrian exposure to the street air pollution in most of traffic loads and atmospheric stability conditions.« less

Cooperative Education. Cosmetic Science: A Career Option for Majors in Chemistry.

ERIC Educational Resources Information Center

Lichtin, J. Leon; Radd, Billie L.

1987-01-01

Discusses the growing field of cosmetic science as a career option for chemistry majors. Outlines the design, formulation, manufacture, stabilization, evaluation, control management, safety, mechanism of action, and claim substantiation of cosmetic products. Provides information on the concerns and professional responsibilities of the cosmetic…

Habitat connectivity and in-stream vegetation control temporal variability of benthic invertebrate communities.

PubMed

Huttunen, K-L; Mykrä, H; Oksanen, J; Astorga, A; Paavola, R; Muotka, T

2017-05-03

One of the key challenges to understanding patterns of β diversity is to disentangle deterministic patterns from stochastic ones. Stochastic processes may mask the influence of deterministic factors on community dynamics, hindering identification of the mechanisms causing variation in community composition. We studied temporal β diversity (among-year dissimilarity) of macroinvertebrate communities in near-pristine boreal streams across 14 years. To assess whether the observed β diversity deviates from that expected by chance, and to identify processes (deterministic vs. stochastic) through which different explanatory factors affect community variability, we used a null model approach. We observed that at the majority of sites temporal β diversity was low indicating high community stability. When stochastic variation was unaccounted for, connectivity was the only variable explaining temporal β diversity, with weakly connected sites exhibiting higher community variability through time. After accounting for stochastic effects, connectivity lost importance, suggesting that it was related to temporal β diversity via random colonization processes. Instead, β diversity was best explained by in-stream vegetation, community variability decreasing with increasing bryophyte cover. These results highlight the potential of stochastic factors to dampen the influence of deterministic processes, affecting our ability to understand and predict changes in biological communities through time.

The patellofemoral joint: from dysplasia to dislocation

PubMed Central

Zaffagnini, Stefano; Grassi, Alberto; Zocco, Gianluca; Rosa, Michele Attilo; Signorelli, Cecilia; Muccioli, Giulio Maria Marcheggiani

2017-01-01

Patellofemoral dysplasia is a major predisposing factor for instability of the patellofemoral joint. However, there is no consensus as to whether patellofemoral dysplasia is genetic in origin, caused by imbalanced forces producing maltracking and remodelling of the trochlea during infancy and growth, or due to other unknown and unexplored factors. The biomechanical effects of patellofemoral dysplasia on patellar stability and on surgical procedures have not been fully investigated. Also, different anatomical and demographic risk factors have been suggested, in an attempt to identify the recurrent dislocators. Therefore, a comprehensive evaluation of all the radiographic, MRI and CT parameters can help the clinician to assess patients with primary and recurrent patellar dislocation and guide management. Patellofemoral dysplasia still represents an extremely challenging condition to manage. Its controversial aetiology and its complex biomechanical behaviour continue to pose more questions than answers to the research community, which reflects the lack of universally accepted guidelines for the correct treatment. However, due to the complexity of this condition, an extremely personalised approach should be reserved for each patient, in considering and addressing the anatomical abnormalities responsible for the symptoms. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160081. Originally published online at www.efortopenreviews.org PMID:28630757