WorldWideScience

Sample records for long-term mechanical behavior

  1. The Influence of NaCl Crystallization on the Long-Term Mechanical Behavior of Sandstone

    Science.gov (United States)

    Zheng, Hong; Feng, Xia-Ting; Jiang, Quan

    2015-01-01

    Salt precipitation can occur in saline aquifers when the pore-fluid concentration exceeds saturation during carbon dioxide sequestration, especially in the dry-out region closest to the wellbore. Results from uniaxial and triaxial compression tests, creep tests, and poromechanical tests indicate that NaCl crystallization in pores enhances the compressive strength and bulk modulus under the given confining pressure, and reduces creep. In addition, it makes the pore liquid pressure in the sandstone less sensitive to changes in the hydrostatic stress under undrained conditions. A poro-viscoelastic model with crystals in the pores is proposed to quantitatively estimate the influence of in-pore NaCl crystallization on the long-term mechanical behavior of sandstone. By considering the thermodynamics of crystallization, a geometrical model of a crystal in a pore space is applied to the quasi-static equilibrium state of the crystallization. The solid-liquid interfacial energy is introduced to provide a convenient approach to couple the mechanical properties of sandstone (as a porous material) and the thermochemistry of the in-pore NaCl crystallization. By adding the solid-liquid interfacial energy, the Clausius-Duhem inequality for the skeleton is established for the viscoelasticity based on the proposed geometrical model of a crystal in the pore space. The constitutive equations are deduced from the free energy balance relationship to evaluate the influence of crystallization on the effective stress in terms of the solid-liquid interfacial energies and the pore-size distribution. By comparing the model's output with the test results, it is found that the poro-viscoelastic model describes the influence of in-pore NaCl crystallization on the long-term mechanical behavior of the sandstone reasonably well.

  2. Long-term in vivo corrosion behavior, biocompatibility and bioresorption mechanism of a bioresorbable nitrided iron scaffold.

    Science.gov (United States)

    Lin, Wenjiao; Qin, Li; Qi, Haiping; Zhang, Deyuan; Zhang, Gui; Gao, Runlin; Qiu, Hong; Xia, Ying; Cao, Ping; Wang, Xiang; Zheng, Wei

    2017-03-15

    Pure iron as a potential bioresorbable material for bioresorbable coronary scaffold has major disadvantages of slow corrosion and bioresorption. However, so far, there are neither quantitative data of long-term in vivo corrosion nor direct experimental evidence for bioresorption of pure iron and its alloys, which are fundamental and vital for developing novel Fe-based alloys overcoming the intrinsic drawbacks of pure iron. This work systemically investigated scaffold performance, long-term in vivo corrosion behavior and biocompatibility of a nitrided iron coronary scaffold and explored its bioresorption mechanism. It was found that the 70μm Fe-based scaffold was superior to a state of the art Co-Cr alloy stent (Xience Prime™) in terms of crossing profile, recoil and radial strength. Mass loss was 76.0±8.5wt% for the nitrided iron scaffold and 44.2±11.4wt% for the pure iron scaffold after 36months implantation in rabbit abdominal aorta (pscaffold showed good long-term biocompatibility in both rabbit and porcine model. Its insoluble corrosion products were demonstrated biosafe and could be cleared away by macrophages from in situ to adventitia to be indiscernible by Micro Computed Tomography and probably finally enter the lymphatics and travel to lymph nodes after 53months implantion in porcine coronary artery. The results indicate that the nitrided iron scaffold with further improvements shall be promising for coronary application.

  3. Long term chemo-hydro-mechanical behavior of compacted soil bentonite polymer complex submitted to synthetic leachate.

    Science.gov (United States)

    Razakamanantsoa, Andry Rico; Djeran-Maigre, Irini

    2016-07-01

    An experimental program is carried out to investigate the long term hydro-mechanical behavior correlated with chemical one of compacted soils with low concentration of Ca-bentonite and Ca-bentonite polymer mixture. The effect of prehydration on the hydraulic performance is compared to the polymer adding effect. All specimens are submitted to synthetic leachate (LS) under different permeation conditions. Several issues are studied: mechanical stability, hydraulic performance, chemical exchange of cations validated with microstructure observations. Scanning Electron Microscope (SEM) observations demonstrate two distinct behaviors: dispersive for Bentonite (B) and B with Polymer P1 (BP1) and flocculated for B with Polymer P2 (BP2). Direct shear tests show that bentonite adding increases the Soil (S) cohesion and decreases the friction angle. Polymer adding behaves similarly by maintaining the soil cohesion and increasing the friction angle. Hydraulic conductivity of prehydrated soil bentonite (SB) and direct permeation of polymer added soil bentonite are studied (SBP1 and SBP2). Hydraulic test duration are in range of 45days to 556days long. Prehydration allows to delay the aggressive effect of the LS in short term but seems to increase its negative effect on the hydraulic conductivity value in long term exposure. SB and SBP1 behave similarly and seem to act in the long term as a granular filler effect. SBP2 presents positive results comparing to the other mixtures: it maintains the hydraulic conductivity and the chemical resistance. Chemical analysis confirms that all specimens are subjected to Na(+) dissolution and Ca(2+) retention which are more pronounced for prehydrated specimen. The short term effect of prehydration and the positive effect of SBP2 are also confirmed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Long-Term Mechanical Behavior of Yucca Mountain Tuff and its Variability, Final Technical Report for Task ORD-FY04-021

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, Jaak J.K.; Ma, Lumin; Zhao, Guohua

    2006-03-20

    The study of the long term mechanical behavior of Yucca Mountain tuffs is important for several reasons. Long term stability of excavations will affect accessibility (e.g. for inspection purposes), and retrievability. Long term instabilities may induce loading of drip shields and/or emplaced waste, thus affecting drip shield and/or waste package corrosion. Failure of excavations will affect airflow, may affect water flow, and may affect temperature distributions. The long term mechanical behavior of rocks remains an elusive topic, loaded with uncertainties. A variety of approaches have been used to improve the understanding of this complex subject, but it is doubtful that it has reached a stage where firm predictions can be considered feasible. The long term mechanical behavior of "soft" rocks, especially evaporites, and in particular rock salt, has been the subject of numerous investigations (e.g. Cristescu and Hunsche, 1998, Cristescu et al, 2002), and basic approaches towards engineering taking into account the long term behavior of such materials have long been well established (e.g. Dreyer, 1972, 1982). The same is certainly not true of "hard" rocks. While it long has been recognized that the long term strength of ?hard? rocks almost certainly is significantly less than that measured during "short", i.e. standard (ASTM D 2938), ISRM suggested (Bieniawski et al, 1978) and conventionally used test procedures (e.g. Bieniawski, 1970, Wawersik, 1972, Hoek and Brown, 1980, p. 150), what limited approaches have been taken to develop strategies toward determining the long term mechanical behavior of "hard" rock remain in the early research and investigation stage, at best. One early model developed specifically for time dependent analysis of underground "hard" rock structures is the phenomenological model by Kaiser and Morgenstern (1981). Brady and Brown (1985, p. 93) state that over a wide range of strain rates, from 10^-8 to 10^2/s the difference in strength is only

  5. Emotional behavior in long-term marriage.

    Science.gov (United States)

    Carstensen, L L; Gottman, J M; Levenson, R W

    1995-03-01

    In exploring the emotional climate of long-term marriages, this study used an observational coding system to identify specific emotional behaviors expressed by middle-aged and older spouses during discussions of a marital problem. One hundred and fifty-six couples differing in age and marital satisfaction were studied. Emotional behaviors expressed by couples differed as a function of age, gender, and marital satisfaction. In older couples, the resolution of conflict was less emotionally negative and more affectionate than in middle-aged marriages. Differences between husbands and wives and between happy and unhappy marriages were also found. Wives were more affectively negative than husbands, whereas husbands were more defensive than wives, and unhappy marriages involved greater exchange of negative affect than happy marriages.

  6. Long term structural dynamics of mechanical systems with local nonlinearities

    NARCIS (Netherlands)

    Fey, R.H.B.; Campen, D.H. van; Kraker, A. de

    1996-01-01

    This paper deals with the long term behavior of periodically excited mechanical systems consisting of linear components and local nonlinearities. The number of degrees of freedom of the linear components is reduced by applying a component mode synthesis technique. Lyapunov exponents are used to iden

  7. Prediction models of long-term leaching behavior and leaching mechanism of glass components and surrogated nuclides in radioactive vitrified waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C.; Lee, K. S. [Department of Industrial Environment and Health, Yonsei University, Wonju (Korea, Republic of); Kim, I. T.; Kim, H. T.; Kim, J. H. [Korea Atomic Energy Research Institute (KAERI), Taejon (Korea, Republic of)

    1999-07-01

    Melting solidification is considered to be a perspective technology for stabilizing incineration ash remaining after incineration of combustible radioactive waste since it has the advantage of improving the physicochemical properties of waste forms. Final waste forms should be characterized to determine the degree to which they fulfills the acceptance criteria of the disposal facility. Chemical durability (leaching resistance) is known to be the most important factor in the assessment of waste forms. In this study, vitrified waste forms are manufactured and characterized. Feed materials consist of simulated radioactive incineration ash and base-glass with different mixing ratios. To assess the chemical durability of vitrified waste forms, the International Standard Organization (ISO) leach test has been conducted at 70 degree C with deionized distilled water as a leachant for 820 days, and the concentrations of glass components and surrogates in the leachates are then analyzed. Two models for predicting long-term leaching behavior of glass components and radionuclides in a glass form are applied to the leached data after 820 days. The model including a fitted parameter from the longer experimental data shows more accuracy, however, the model with shorter leaching test results offers the advantage of being able to predict the long-term behavior from the short-term experimental data. The leaching mechanisms of surrogates and glass components were also investigated by using two semi-empirical kinetic models and were found to be dissolution with diffusion. (author)

  8. Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Jageman, Robert J

    2009-09-12

    Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by

  9. A Long-term Mechanism Needed to Safeguard Financial Stability

    Institute of Scientific and Technical Information of China (English)

    何德旭

    2007-01-01

    In the post-WTO era, China has encountered new difficulties in maintaining financial stability. Quick fix and emergency measures can no longer be relied on in the long run, and therefore, a long-term mechanism of financial stability must be put in place. This article recommends that China should focus on furthering financial reform, accelerating financial innovation and improving the legal system to promote a strong and competitive finance industry that is less vulnerable to financial hazards.

  10. Effect of mold temperature on short and long-term mechanical properties of PBT

    Directory of Open Access Journals (Sweden)

    2008-02-01

    Full Text Available In this work, the effect of mold temperature variation on the short-term mechanical properties obtained from the tensile and Charpy impact tests, and the long-term mechanical properties obtained from dynamic mechanical loading and flexural creep of injection molded polybutylene terepthalate (PBT are reported. It has been observed that the effect of changing the processing condition viz. mold temperature on the viscoelastic properties are more pronounced when their long-term behavior is tested. The tensile and impact properties showed only a negligible effect to the change in mold temperature. Further, analysis of the creep curves by applying a four-element Burger model presented a comprehensive understanding of their long-term viscoelastic behavior with respect to the change in mold temperature.

  11. Accumulation and long term behavior of radiocesium in tropical plants

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, R.M.; Carvalho, C.; Mosquera, B.; Macario, K.; Veiga, R.; Sanches, N.; Bastos, J.; Saavedra, R.; Iguatemy, M. [Universidade Federal Fluminense, Niteroi (Brazil)

    2006-07-01

    Full text of publication follows: In recent years, there has been a growing interest in the evaluation of nutrient fluxes and radioactive contaminants in forest and agricultural ecosystems. Several studies on forest ecosystems have been carried out, mostly in Europe, after the Chernobyl accident. Japanese forest sites and native plant species of the Marshall Islands have also been extensively investigated. These studies have been used for various purposes, including the development of models for predicting plant concentrations from soil concentration measurements or the long term of dietary contamination by radiocesium following a fallout nuclear. Cesium is an alkali metal just like potassium and its behavior in nature, as well as in the human body, is similar to that of potassium. Uptake of 137 Cs from contaminated soil represents a significant pathway of human radiation exposure, either due to the direct consumption of cereals, fruits and vegetables or, indirectly, following consumption of milk and meat from animals fed on contaminated vegetable matter. The decline of 137 Cs levels as function of time of fruit trees is of interest given its long life in the field. Therefore, the cesium behavior is important in the design of management strategies to mitigate any negative health effects of radioactivity on the environment. It is also important to apply the current knowledge of the transport and distribution of salts derived from forest ecosystems in agricultural ecosystems, especially for tropical fruit trees. So far, in the South hemisphere there have been only a few studies on this subject, without conclusive results. With this aim, the Laboratory of Radioecology (L.A.R.A.) of the Universidade Federal Fluminense has been performing analyzes of 137 Cs and 40 K concentrations in several tropical plants (guava, mango, avocado, pomegranate, papaya, manioc and chili pepper trees) in order to determine the accumulation of these radionuclides throughout these trees and

  12. Long term behavior of self-compacting reinforced concrete beams

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-jie; YU Zhi-wu; JIANG Li-zhong

    2008-01-01

    Tests were carded out on 8 self-compacting reinforced concrete(SCC) beams and 4 normal reinforced concrete beams. The effects of mode of consolidation, load level, reinforcing ratio and structural type on long term behavior of SCC were investigated. Under the same environmental conditions, the shrinkage-time curve of self-compacting concrete beam is very similar to that of normal concrete beam. For both self-compacting reinforced concrete beams and normal reinforced concrete beams, the rate of shrinkage at early stages is higher, the shrinkage strain at 2 months is about 60% of the maximum value at one year. The shrinkage strain of self-compacting reinforced concrete beam after one year is about 450×10-6. Creep deflection of self-compacting reinforced concrete beam decreases as the tensile reinforcing ratio increases. The deflection creep coefficient of self-compacting reinforced concrete beam after one and a half year is about 1.6, which is very close to that of normal reinforced concrete beams cast with vibration. Extra cautions considering shrinkage and creep behavior are not needed for the use of SCC in engineering practices.

  13. Seafloor Weathering As a Long-Term Climate Regulation Mechanism

    Science.gov (United States)

    Farahat, N. X.; Abbot, D. S.; Archer, D. E.

    2014-12-01

    The global carbon cycle determines the distribution of carbon between the atmosphere, ocean, and solid earth. Carbon from the mantle enters the Earth's surficial environment as CO2 by volcanic outgassing, and carbon is buried in the oceanic crust as carbonate rocks during silicate rock weathering. The subduction of carbonate-rich oceanic plates returns carbon to the mantle, closing the cycle. Subtle adjustments in continental silicate weathering, widely held to consume atmospheric CO2 at a rate controlled by climate, are believed to have maintained habitable conditions throughout Earth's history. This long term climate regulation mechanism is known as a climate-weathering feedback. Seafloor weathering, low-temperature basalt alteration and carbonate precipitation in the permeable upper oceanic crust, has been proposed as a climate-weathering feedback as well, but the link to climate is presently poorly understood. Such a climate regulation mechanism would be particularly important on waterworld planets where continental silicate weathering cannot regulate climate. It has so far not been possible to determine whether changes in seafloor weathering could contribute to climate regulation on Earth or in a waterworld scenario because the necessary modeling framework has not yet been developed. However, advances in porous media flow modeling and reactive transport modeling, as well as the availability of inexpensive computational power, allow the seafloor weathering problem to be looked at in greater detail. We have developed a spatially resolved two-dimmensional (2D) numerical model of seafloor weathering in the permeable upper oceanic crust. This model simulates 2D off-axis hydrothermal flow coupled to geochemical alteration of seafloor basalt by modeling reactive transport of chemical species in seawater-derived hydrothermal fluids. The focus of this research is to use the model to determine the effect of geological and climatic factors on seafloor weathering, which

  14. Long-term Photometric Behavior of Outbursting AM CVn Systems

    CERN Document Server

    Levitan, David; Prince, Thomas A; Kulkarni, Shrinivas R; Laher, Russ; Ofek, Eran O; Sesar, Branimir; Surace, Jason

    2014-01-01

    The AM CVn systems are a class of He-rich, post-period minimum, semi-detached, ultra-compact binaries. Their long-term light curves have been poorly understood due to the few systems known and the long (hundreds of days) recurrence times between outbursts. We present combined photometric light curves from the LINEAR, CRTS, and PTF synoptic surveys to study the photometric variability of these systems over an almost 10 yr period. These light curves provide a much clearer picture of the outburst phenomena that these systems undergo. We characterize the photometric behavior of most known outbursting AM CVn systems and establish a relation between their outburst properties and the systems' orbital periods. We also explore why some systems have only shown a single outburst so far and expand the previously accepted phenomenological states of AM CVn systems. We conclude that the outbursts of these systems show evolution with respect to the orbital period, which can likely be attributed to the decreasing mass transfe...

  15. Probabilistic simulation of long term behavior in polymer matrix composites

    Science.gov (United States)

    Shah, A. R.; Singhal, S. N.; Murthy, P. L. N.; Chamis, C. C.

    1995-04-01

    A methodology to compute cumulative probability distribution functions (CDF) of fatigue life for different ratios, r of applied stress to the laminate strength based on first ply failure criteria has been developed and demonstrated. Degradation effects due to long term environmental exposure and mechanical cyclic loads are considered in the simulation process. A unified time-stress dependent multi-factor interaction equation model developed at NASA Lewis Research Center has been used to account for the degradation/aging of material properties due to cyclic loads. Fast probability integration method is used to perform probabilistic simulation of uncertainties. Sensitivity of fatigue life reliability to uncertainties in the primitive random variables are computed and their significance in the reliability based design for maximum life is discussed. The results show that the graphite/epoxy (0/+45/90) deg laminate with ply thickness 0.125 in. has 500,000 cycles life for applied stress to laminate strength ratio of 0.6 and a reliability of 0.999. Also, the fatigue life reliability has been found to be most sensitive to the ply thickness and matrix tensile strength. Tighter quality controls must therefore be enforced on ply thickness and matrix strength in order to achieve high reliability of the structure.

  16. Long Term Fatigue Behavior of Zirconia Based Dental Ceramics

    Directory of Open Access Journals (Sweden)

    Moustafa N. Aboushelib

    2010-04-01

    Full Text Available This study evaluated the influence of cyclic loading on zirconia bar-shaped specimens after being subjected to three different surface treatments: particle abrasion with either 50 μm or 110 μm alumina and grinding with diamond points, while polished specimens served as a control. Statistical analysis revealed significant reduction (38-67% in flexure strength (P < 0.001 after three million cycles of dynamic loading for all surface treatments. Scanning electron imaging revealed grain boundary thickening, grain pull-out, and micro-cracking as the main structural defects. The results suggest that various surface treatments of zirconia based dental ceramics may significantly influence their long term fatigue resistance in the oral environment.

  17. Comprehensive assessment of depression and behavioral problems in long-term care.

    NARCIS (Netherlands)

    Koopmans, R.T.C.M.; Zuidema, S.U.; Leontjevas, R.; Gerritsen, D.L.

    2010-01-01

    BACKGROUND: The IPA Taskforce on Mental Health Issues in Long-Term Care Homes seeks to improve mental health care in long-term care (LTC) homes. The aim of this paper is to provide recommendations on comprehensive assessment of depression and behavioral problems in order to further stimulate countri

  18. Comprehensive assessment of depression and behavioral problems in long-term care

    NARCIS (Netherlands)

    Koopmans, Raymond T C M; Zuidema, Sytse U; Leontjevas, Roeslan; Gerritsen, Debby L

    2010-01-01

    BACKGROUND: The IPA Taskforce on Mental Health Issues in Long-Term Care Homes seeks to improve mental health care in long-term care (LTC) homes. The aim of this paper is to provide recommendations on comprehensive assessment of depression and behavioral problems in order to further stimulate countri

  19. Prosocial Behavior: Long-Term Trajectories and Psychosocial Outcomes.

    Science.gov (United States)

    Flynn, Elinor; Ehrenreich, Samuel E; Beron, Kurt J; Underwood, Marion K

    2015-08-01

    This study investigated developmental trajectories for prosocial behavior for a sample followed from age 10 - 18 and examined possible adjustment outcomes associated with membership in different trajectory groups. Participants were 136 boys and 148 girls, their teachers, and their parents (19.4% African American, 2.4% Asian, 51.9% Caucasian, 19.5% Hispanic, and 5.8% other). Teachers rated children's prosocial behavior yearly in grades 4 - 12. At the end of the 12(th) grade year, teachers, parents, and participants reported externalizing behaviors and participants reported internalizing symptoms, narcissism, and features of borderline personality disorder. Results suggested that prosocial behavior remained stable from middle childhood through late adolescence. Group-based mixture modeling revealed three prosocial trajectory groups: low (18.7%), medium (52.8%), and high (29.6%). Membership in the high prosocial trajectory group predicted lower levels of externalizing behavior as compared to the low prosocial trajectory group, and for girls, lower levels of internalizing symptoms. Membership in the medium prosocial trajectory group also predicted being lower on externalizing behaviors. Membership in the high prosocial trajectory group predicted lower levels of borderline personality features for girls only.

  20. Long-Term Association between Developmental Assets and Health Behaviors

    Science.gov (United States)

    Bleck, Jennifer; DeBate, Rita

    2016-01-01

    Introduction: Based on internal and external assets, the positive youth development approach aims to increase the capacity among adolescents to overcome challenges as they transition to adulthood. Developmental assets have been found to be positively associated with academic achievement, a variety of health promoting behaviors, and improved…

  1. Long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals

    Science.gov (United States)

    Grand, Laszlo; Ftomov, Sergiu; Timofeev, Igor

    2012-01-01

    Parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. In this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (LFP, MUA, EOG, EMG) and activity data (accelerometer, video) from freely moving cats. The method is based on the integration of commercially available components into a simple monitoring system and is complete with accelerometers and the needed signal processing tools. LFP activities of freely moving group-housed cats were recorded from multiple intracortical areas and from the hippocampus. EMG, EOG, accelerometer and video were simultaneously acquired with LFP activities 24-h a day for 3 months. These recordings confirm the possibility of using our wireless method for 24-h long-term monitoring of neurophysiological and behavioral data of freely moving experimental animals such as cats, ferrets, rabbits and other large animals. PMID:23099345

  2. The properties and mechanism of long-term memory in nonparametric volatility

    Science.gov (United States)

    Li, Handong; Cao, Shi-Nan; Wang, Yan

    2010-08-01

    Recent empirical literature documents the presence of long-term memory in return volatility. But the mechanism of the existence of long-term memory is still unclear. In this paper, we investigate the origin and properties of long-term memory with nonparametric volatility, using high-frequency time series data of the Chinese Shanghai Composite Stock Price Index. We perform Detrended Fluctuation Analysis (DFA) on three different nonparametric volatility estimators with different sampling frequencies. For the same volatility series, the Hurst exponents reduce as the sampling time interval increases, but they are still larger than 1/2, which means that no matter how the interval changes, it still cannot change the existence of long memory. RRV presents a relatively stable property on long-term memory and is less influenced by sampling frequency. RV and RBV have some evolutionary trends depending on time intervals, which indicating that the jump component has no significant impact on the long-term memory property. This suggests that the presence of long-term memory in nonparametric volatility can be contributed to the integrated variance component. Considering the impact of microstructure noise, RBV and RRV still present long-term memory under various time intervals. We can infer that the presence of long-term memory in realized volatility is not affected by market microstructure noise. Our findings imply that the long-term memory phenomenon is an inherent characteristic of the data generating process, not a result of microstructure noise or volatility clustering.

  3. Insulin induces long-term depression of VTA dopamine neurons via an endocannabinoid-mediated mechanism

    Science.gov (United States)

    Labouèbe, Gwenaël; Liu, Shuai; Dias, Carine; Zou, Haiyan; Wong, Jovi C.Y.; Karunakaran, Subashini; Clee, Susanne M.; Phillips, Anthony; Boutrel, Benjamin; Borgland, Stephanie L.

    2014-01-01

    The prevalence of obesity has drastically increased over the last few decades. Exploration into how hunger and satiety signals influence the reward system can help us to understand non-homeostatic mechanisms of feeding. Evidence suggests that insulin may act in the ventral tegmental area (VTA), a critical site for reward-seeking behavior, to suppress feeding. However, the neural mechanisms underlying insulin effects in the VTA remain unknown. We demonstrate that insulin, a circulating catabolic peptide that inhibits feeding, can induce a long-term depression (LTD) of excitatory synapses onto VTA dopamine neurons. This effect requires endocannabinoid-mediated presynaptic inhibition of glutamate release. Furthermore, after a sweetened high fat meal, which elevates endogenous insulin levels, insulin-induced LTD is occluded. Finally, insulin in the VTA reduces food anticipatory behavior and conditioned place preference for food. Taken together, these results suggest that insulin in the VTA suppresses excitatory synaptic transmission and reduces salience of food-related cues. PMID:23354329

  4. Commitment and Lapse Behavior in Long-Term Insurance: A Case Study

    OpenAIRE

    Pinquet, Jean; Guillén, Montserrat; Ayuso, Mercedes

    2011-01-01

    International audience; This paper presents a case study of a portfolio of individual long-term insurance contracts sold by a Spanish mutual company. We describe the risk levels, the rating structure and the implied cross-subsidies on a portfolio of policies providing health, life and long-term care insurance. We show evidence of reclassification risk through the history of disability spells. We also analyze the lapse behavior and seek to provide a rationale for the portfolio's dynamics. Last...

  5. Long-term tillage effects on soil metolachlor sorption and desorption behavior.

    Science.gov (United States)

    Ding, Guangwei; Novak, Jeffrey M; Herbert, Stephen; Xing, Baoshan

    2002-09-01

    Sorption and desorption are two important processes that influence the amount of pesticides retained by soils. However, the detailed sorption mechanisms as influenced by soil tillage management are unclear. This study examined the sorption and desorption characteristics of metolachlor [2-chloro-N-(2-ethyl-6-methyphenyl)-N-(2-methoxy-1-methylethyl)-acetamide] using the soil samples collected from the long-term conservation tillage (CnT) and conventional tillage (CT) research plots established in 1979 in Darlinton, SC. Humic acid (HA) and humin were extracted from the soils and used in the sorption experiments along with the whole soil samples. The sorption experiments were conducted using a batch-equilibration method. Three sequential desorption rinses were carried out following the sorption experiments. By comparing metolachlor sorption and desorption results we observed hysteresis for all soil samples and their organic matter fractions. Sorption nonlinearity (N) and hysteresis were dependent on the structure and composition of soil organic matter (SOM), e.g., Freundlich isotherm exponents (N) of HA and humin from CnT were higher than those of CT treatment, which may be related to high aromaticity of SOM fractions in CT treatment. Sorption capacity (K'f) was positively correlated with soil organic carbon (SOC) content. These results show that long-term tillage management can greatly affect metolachlor sorption and desorption behavior probably by qualitative differences in the structural characteristics of the humic substances.

  6. A novel conceptual framework for understanding the mechanism of adherence to long term therapies.

    Science.gov (United States)

    Reach, Gérard

    2008-02-02

    The World Health Organization claimed recently that improving patient adherence to long term therapies would be more beneficial than any biomedical progress. First, however, we must understand its mechanisms. In this paper I propose a novel approach using concepts elaborated in a field rarely explored in medicine, the philosophy of mind. While conventional psychological models (eg, the Health Belief Model) provide explanations and predictions which have only a statistical value, the philosophical assumption that mental states (eg, beliefs) are causally efficient (mental causation) can provide the basis for a causal theory of health behaviors. This paper shows that nonadherence to long term therapies can be described as the medical expression of a philosophical concept, that is, weakness of will. I use philosophical explanations of this concept to suggest a mechanistic explanation of nonadherence. I propose that it results from the failure of two principles of rationality. First, a principle of continence, described by the philosopher Donald Davidson in his explanation of weakness of will. This principle exhorts us to act after having considered all available arguments and according to which option we consider best. However, patients conforming to this principle of continence should rationally be nonadherent. Indeed, when patients face a choice between adherence and nonadherence, they must decide, in general, between a large, but delayed reward (eg, health) and a small, but immediate reward (eg, smoking a cigarette). According to concepts elaborated by George Ainslie and Jon Elster, the force of our desires is strongly influenced by the proximity of reward. This inter-temporal choice theory on one hand, and the mere principle of continence on the other, should therefore lead to nonadherence. Nevertheless, adherence to long term therapies is possible, as a result of the intervention of an additional principle, the principle of foresight, which tells us to give

  7. Rehabilitation Considerations for Children Dependent on Long-Term Mechanical Ventilation

    OpenAIRE

    Dumas, Helene M.

    2012-01-01

    The purposes of this paper are as follows (1) to describe the prevalence, etiology, and care settings for children dependent on long-term mechanical ventilation (MV); (2) to provide a brief introduction to MV and weaning; (3) to explore health care utilization and cost of care; and, primarily, (4) to discuss the rehabilitation needs of children dependent on long-term MV including activities of daily living, mobility, communication, psychosocial needs, and recreation and leisure. Children with...

  8. Applying Psychological Theories to Promote Long-Term Maintenance of Health Behaviors

    Science.gov (United States)

    Joseph, Rodney P.; Daniel, Casey L.; Thind, Herpreet; Benitez, Tanya J.; Pekmezi, Dori

    2014-01-01

    Behavioral health theory provides a framework for researchers to design, implement, and evaluate the effects of health promotion programs. However, limited research has examined theories used in interventions to promote long-term maintenance of health behaviors. The purpose of this review was to evaluate the available literature and identify prominent behavioral health theories used in intervention research to promote maintenance of health behaviors. We reviewed theories used in intervention research assessing long-term maintenance (≥ 6 months post-intervention) of physical activity, weight loss, and smoking cessation. Five prominent behavioral theories were referenced by the 34 studies included in the review: Self-Determination Theory, Theory of Planned Behavior, Social Cognitive Theory, Transtheoretical Model, and Social Ecological Model. Descriptions and examples of applications of these theories are provided. Implications for future research are discussed. PMID:28217036

  9. Short-term cognitive-behavioral therapy for binge eating disorder: long-term efficacy and predictors of long-term treatment success.

    Science.gov (United States)

    Fischer, Sophia; Meyer, Andrea H; Dremmel, Daniela; Schlup, Barbara; Munsch, Simone

    2014-07-01

    The present study evaluates the long-term efficacy (four years after treatment) of a short-term Cognitive-Behavioral Treatment (CBT) of Binge Eating Disorder (BED). We examined patient characteristics, mostly measured at the end of treatment, for their predictive value of long-term success. Forty-one BED-patients between 18 and 70 years took part in a randomized controlled trial (RCT) for a short-term treatment and were evaluated until 4 years after treatment. Assessments comprised structured interviews on comorbid mental disorder/eating disorder pathology and questionnaires on eating disorder pathology/general psychopathology. BED core symptoms and associated psychopathology improved substantially during treatment phase and further improved or at least remained stable during the follow-up period. End of treatment predictors for long term success were elevated weight and eating concern and higher frequency of objective binges. Tailoring additional interventions to patients' individual needs could further improve treatment efficacy.

  10. Thermal stability of the French nuclear waste glass - long term behavior modeling; Etude de la stabilite thermique du verre nucleaire. Modelisation de son evolution a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Orlhac, X

    2000-07-01

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO{sub 4}, CeCO{sub 2}, ZnCr{sub 2}O{sub 4}). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO{sub 2}SiO{sub 2}) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  11. Long-term use of electrical aversion treatment with self-injurious behavior

    NARCIS (Netherlands)

    Duker, P.C.C.; Seys, D.M.

    1996-01-01

    Twelve severely and profoundly mentally retarded individuals with life-threatening self-injurious behaviors were exposed to electrical aversion treatment using a remotely controlled device. Long-term effectiveness was assessed for periods ranging from 2 to 47 months for the 12 individuals,

  12. Behavioral Specifications of Reward-Associated Long-Term Memory Enhancement in Humans

    Science.gov (United States)

    Wittmann, Bianca C.; Dolan, Raymond J.; Duzel, Emrah

    2011-01-01

    Recent functional imaging studies link reward-related activation of the midbrain substantia nigra-ventral tegmental area (SN/VTA), the site of origin of ascending dopaminergic projections, with improved long-term episodic memory. Here, we investigated in two behavioral experiments how (1) the contingency between item properties and reward, (2) the…

  13. An Evaluation of Persistence of Treatment Effects during Long-Term Treatment of Destructive Behavior

    Science.gov (United States)

    Wacker, David P.; Harding, Jay W.; Berg, Wendy K.; Lee, John F.; Schieltz, Kelly M.; Padilla, Yaniz C.; Nevin, John A.; Shahan, Timothy A.

    2011-01-01

    Eight young children who displayed destructive behavior maintained, at least in part, by negative reinforcement received long-term functional communication training (FCT). During FCT, the children completed a portion of a task and then touched a communication card attached to a microswitch to obtain brief breaks. Prior to and intermittently…

  14. Long-term performance and behavior of sows fed high levels of non-starch polysaccharides

    NARCIS (Netherlands)

    Peet-Schwering, van der C.M.C.

    2004-01-01

    The main objective of this thesis was to investigate the long-term effects of feeding sows high levels of dietary fermentable non-starch polysaccharides CNSP) (i.e., NSP from sugar beet pulp) restrictedly or ad libitum during gestation or ad libitum during lactation on behavior, reproductive perform

  15. Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia

    OpenAIRE

    Chen, Shanping; Cai, Diancai; Pearce, Kaycey; Sun, Philip Y-W; Roberts, Adam C.; Glanzman, David L.

    2014-01-01

    eLife digest Cells called neurons allow information to travel quickly around the body so that we can rapidly respond to any changes that we sense in our environment. This includes non-conscious reactions, such as the knee-jerk reflex in humans. Reflexes and other behaviors can be influenced by long-term memory, and it is thought that long-term memory is stored by changes in the synapses that connect neurons to each other. The reflexes of a sea slug known as Aplysia are often used to study mem...

  16. Long Term Behavior of Composite Material Polyester-Wood Reinforced Glass Fiber

    Directory of Open Access Journals (Sweden)

    E.T. Olodo

    2013-06-01

    Full Text Available If the industry generally considers composite materials as potentially interesting, the lack of durability makes their often limited employment. Indeed, the design of composite structures often requires taking account of the long-term behaviour under various types of complex solicitations. This study is based on the development of a methodology for modeling the long term behavior under constant load for multilayer composite structures subjected to complex solicitations. This study is on the evaluation of the long-term behaviour of tri-layers glass/polyester-wood composite material. The objective is the evaluation of the long term strength of this material by the Goldenblat-Kopnov criterion. The studied model is an orthotropic tri layer plate of sandwich type with upper and lower flanges (skins are in composite material glass/polyester KACT-B and the intermediate layer (soul is pine wood. The character of loading of the plate is reflected in the model by the functions &sigmaik(&xi, &sigmamn(&xi which can be of different natures. For example, to load in the long term by constant constraints in time (the weight own element for example, we will have: &sigmaik = const &sigmamn = const. The results of the calculations show that, for this type of material, the conditions of strength to the dangerous points of the plate are met.

  17. Contribution of recovery mechanisms of microstructure during long-term creep of Gr.91 steels

    Science.gov (United States)

    Ghassemi-Armaki, H.; Chen, R. P.; Maruyama, K.; Igarashi, M.

    2013-02-01

    Creep rupture life and microstructural degradation have been studied in two heats of Gr.91 steels. The coarsening of subgrains and precipitates, mainly M23C6 and MX, has been evaluated during static aging and creep. Hardness of head (static aging) and gauge (creep) portions of crept samples were measured to know their relation with microstructural degradation during long-term exposure. The correlation between subgrain size and spacing of precipitates and hardness has been equated. As an example, there is a close correlation between hardness value and inverse subgrains size in Gr.91 steels, regardless of aging or creep conditions. The appearance of three recovery mechanisms was found during long-term creep, namely: strain-induced recovery, pure static recovery and strain-assisted static recovery. By equated correlations between subgrain size, precipitates and hardness, the contribution of three recovery mechanisms to subgrain coarsening and hardness drop were calculated for two creep conditions at 700 °C in long-term creep region, where breakdown of creep strength has happen. The calculated data accord well with experimental data obtained from aged and crept samples. The contribution of static recovery to the subgrain coarsening and consequent hardness drop during long-term creep increases with increasing creep time. The significant contribution of both static recovery mechanisms can result in the breakdown of creep strength in long-term creep region.

  18. An Evaluation of Persistence of Treatment Effects During Long-Term Treatment of Destructive Behavior

    OpenAIRE

    Wacker, David P.; Harding, Jay W.; Berg, Wendy K; Lee, John F.; Schieltz, Kelly M.; Padilla, Yaniz C; Nevin, John A.; Shahan, Timothy A

    2011-01-01

    Eight young children who displayed destructive behavior maintained, at least in part, by negative reinforcement received long-term functional communication training (FCT). During FCT, the children completed a portion of a task and then touched a communication card attached to a microswitch to obtain brief breaks. Prior to and intermittently throughout FCT, extinction probes were conducted within a withdrawal design in which task completion, manding, and destructive behavior were placed on ext...

  19. The maintenance of behavioral change: the case for long-term follow-ups.

    Science.gov (United States)

    Foxx, Richard M

    2013-11-01

    This article discusses response maintenance, the durability of behavior change after therapy, treatment, or training ends. Response maintenance is one of the three forms of generalized behavior change, with the others being setting/situation generalization and response generalization. Long-term maintenance of treatment effects is an important issue after behavior change has taken place and is the goal of most programs. Areas discussed include factors affecting the study of maintenance, techniques for programming it, and analyzing and evaluating strategies for promoting it. This article presents a number of long-term follow-ups of programs designed to treat the addictive behaviors of typical adults (Foxx, 1982; Foxx, Brown, & Katz, 1981) and to teach social skills (Foxx & Faw, 1992) and language (Foxx & Faw, 1990) to individuals with intellectual disabilities and autism as well as to decrease their severe maladaptive behaviors (Foxx, 1990; Foxx & Livesay, 1984). In the process, various factors that appeared to contribute to long-term maintenance are identified. The article concludes with some recommendations regarding the study of maintenance.

  20. NLRP3 INFLAMMASOME ACTIVATION CONTRIBUTES TO LONG-TERM BEHAVIORAL ALTERATIONS IN MICE INJECTED WITH LIPOPOLYSACCHARIDE

    Science.gov (United States)

    ZHU, WEI; CAO, FENG-SHENG; FENG, JUN; CHEN, HUA-WENG; WAN, JIE-RU; LU, QING; WANG, JIAN

    2017-01-01

    Lipopolysaccharide (LPS) might affect the central nervous system by causing neuroinflammation, which subsequently leads to brain damage and dysfunction. In this study, we evaluated the role of nod-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome activation in long-term behavioral alterations of 8-week-old male C57BL/6 mice injected intraperitoneally with LPS (5 mg/kg). At different time points after injection, we assessed locomotor function with a 24-point neurologic deficit scoring system and the rotarod test; assessed recognition memory with the novel object recognition test; and assessed emotional abnormality (anhedonia and behavioral despair) with the tail suspension test, forced swim test, and sucrose preference test. We also assessed protein expression of NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1 p10 in hippocampus by Western blotting; measured levels of interleukin (IL)-1β, IL-18, tumor necrosis factor α (TNFα), and IL-10 in hippocampus; measured TNFα and IL-1β in serum by ELISA; and evaluated microglial activity in hippocampus by Iba1 immunofluorescence. We found that LPS-injected mice displayed long-term depression-like behaviors and recognition memory deficit; elevated expression of NLRP3, ASC, and caspase-1 p10; increased levels of IL-1β, IL-18, and TNFα; decreased levels of IL-10; and increased microglial activation. These effects were blocked by the NLRP3 inflammasome inhibitor Ac-Tyr-Val-Ala-Asp-chloromethylketone. The results demonstrate proof of concept that NLRP3 inflammasome activation contributes to long-term behavioral alterations in LPS-exposed mice, probably through enhanced inflammation, and that NLRP3 inflammasome inhibition might alleviate peripheral and brain inflammation and thereby ameliorate long-term behavioral alterations in LPS-exposed mice. PMID:27923741

  1. Long-term oxytocin administration improves social behaviors in a girl with autistic disorder

    Directory of Open Access Journals (Sweden)

    Kosaka Hirotaka

    2012-08-01

    Full Text Available Abstract Background Patients with autism spectrum disorders (ASDs exhibit core autistic symptoms including social impairments from early childhood and mostly show secondary disabilities such as irritability and aggressive behavior based on core symptoms. However, there are still no radical treatments of social impairments in these patients. Oxytocin has been reported to play important roles in multiple social behaviors dependent on social recognition, and has been expected as one of the effective treatments of social impairments of patients with ASDs. Case presentation We present a case of a 16-year-old girl with autistic disorder who treated by long-term administration of oxytocin nasal spray. Her autistic symptoms were successfully treated by two month administration; the girl’s social interactions and social communication began to improve without adverse effects. Her irritability and aggressive behavior also improved dramatically with marked decreases in aberrant behavior checklist scores from 69 to 7. Conclusion This case is the first to illustrate long-term administration of oxytocin nasal spray in the targeted treatment of social impairments in a female with autistic disorder. This case suggests that long-term nasal oxytocin spray is promising and well-tolerated for treatment of social impairments of patients with ASDs.

  2. Long-Term Behaviors of Stochastic Interest Rate Models with Jumps and Memory

    CERN Document Server

    Bao, Jianhai

    2011-01-01

    In this paper we show the convergence of the long-term return $t^{-\\mu}\\int_0^tX(s)\\d s$ for some $\\mu\\geq1$, where $X$ is the short-term interest rate which follows an extension of Cox-Ingersoll-Ross type model with jumps and memory, and, as an application, we also investigate the corresponding behavior of two-factor Cox-Ingersoll-Ross model with jumps and memory

  3. Medium to long term behavior of MR dampers for structural control

    Science.gov (United States)

    Caterino, N.; Azmoodeh, B. M.; Occhiuzzi, A.

    2014-10-01

    The medium to long term behavior of a prototype magnetorheological (MR) damper for structural control of earthquake induced vibrations is investigated herein. Unlike some applications for which MR devices experience frequent dynamic loads, seismic dampers might not be used for most of their life, staying dormant for a long period until an earthquake hits the hosting structure. This work aims to evaluate the effectiveness of a MR damper after years of inactivity. A MR device has been tested twice, first in 2008 and then in 2013, after five years of absolute inactivity. The comparison between the results of the two tests is made in terms of force-displacement loops. It is shown that, after a 5-year rest, only part of the first stroke of the damper is characterized by an unexpected response of the damper. After half a stroke, the damper quickly returned to behave like in 2008, even if a slight non-reversible decrease of the reacting force has been recorded. The latter is found to be more evident (5-7%) for larger currents, less visible in the case of zero magnetic field. From the point of view of civil engineering, this decay of performance is definitely acceptable, being largely bounded within the limits of the uncertainties typically involved and taken into account in the structural design. Finally, starting from a literature review, the paper discusses the possible causes of the observed changes in the mechanical response of the damper over time.

  4. SPIN90 Modulates Long-Term Depression and Behavioral Flexibility in the Hippocampus

    Directory of Open Access Journals (Sweden)

    Dae Hwan Kim

    2017-09-01

    Full Text Available The importance of actin-binding proteins (ABPs in the regulation of synapse morphology and plasticity has been well established. SH3 protein interacting with Nck, 90 kDa (SPIN90, an Nck-interacting protein highly expressed in synapses, is essential for actin remodeling and dendritic spine morphology. Synaptic targeting of SPIN90 to spine heads or dendritic shafts depends on its phosphorylation state, leading to blockage of cofilin-mediated actin depolymerization and spine shrinkage. However, the physiological role of SPIN90 in long-term plasticity, learning and memory are largely unknown. In this study, we demonstrate that Spin90-knockout (KO mice exhibit substantial deficits in synaptic plasticity and behavioral flexibility. We found that loss of SPIN90 disrupted dendritic spine density in CA1 neurons of the hippocampus and significantly impaired long-term depression (LTD, leaving basal synaptic transmission and long-term potentiation (LTP intact. These impairments were due in part to deficits in AMPA receptor endocytosis and its pre-requisites, GluA1 dephosphorylation and postsynaptic density (PSD 95 phosphorylation, but also by an intrinsic activation of Akt-GSK3β signaling as a result of Spin90-KO. In accordance with these defects, mice lacking SPIN90 were found to carry significant deficits in object-recognition and behavioral flexibility, while learning ability was largely unaffected. Collectively, these findings demonstrate a novel modulatory role for SPIN90 in hippocampal LTD and behavioral flexibility.

  5. Long term bending behavior of ultra-high performance concrete (UHPC beams

    Directory of Open Access Journals (Sweden)

    Gheorghe-Alexandru BARBOS

    2015-12-01

    Full Text Available Unlike normal concrete (NC the behavior of ultra-high performance concrete (UHPC is different under long-term efforts, if we refer to creep, shrinkage or long-term deflections. It is well known that UHPC has special properties, like compressive strength higher than 150 MPa and tensile strength higher than 20 MPa - in case of UHPC reinforced with steel-fibers. Nevertheless, UHPC behavior is not completely elucidated in what concerns creep straining or serviceability behavior in case of structural elements. Some studies made on UHPC samples shown that creep is significantly reduced if the concrete is subjected to heat treatment and if it contains steel-fiber reinforcement. Relating thereto, it is important to know how does structural elements made of this type of concrete works in service life under long-term loadings. The results obtained on UHPC samples, regarding creep straining from tension or compression efforts may not be generalized in case of structural elements (e.g. beams, slabs, columns subjected to bending. By performing this study, it was aimed to understand the influence of heat treatment and steel-fiber addition on the rheological phenomena of UHPC bended beams.

  6. Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia.

    Science.gov (United States)

    Chen, Shanping; Cai, Diancai; Pearce, Kaycey; Sun, Philip Y-W; Roberts, Adam C; Glanzman, David L

    2014-11-17

    Long-term memory (LTM) is believed to be stored in the brain as changes in synaptic connections. Here, we show that LTM storage and synaptic change can be dissociated. Cocultures of Aplysia sensory and motor neurons were trained with spaced pulses of serotonin, which induces long-term facilitation. Serotonin (5HT) triggered growth of new presynaptic varicosities, a synaptic mechanism of long-term sensitization. Following 5HT training, two antimnemonic treatments-reconsolidation blockade and inhibition of PKM--caused the number of presynaptic varicosities to revert to the original, pretraining value. Surprisingly, the final synaptic structure was not achieved by targeted retraction of the 5HT-induced varicosities but, rather, by an apparently arbitrary retraction of both 5HT-induced and original synapses. In addition, we find evidence that the LTM for sensitization persists covertly after its apparent elimination by the same antimnemonic treatments that erase learning-related synaptic growth. These results challenge the idea that stable synapses store long-term memories.

  7. FEATURES OF LONG-TERM MECHANICAL CIRCULATORY SUPPORT WITH CONTINUOUS-FLOW PUMP

    Directory of Open Access Journals (Sweden)

    G. P. Itkin

    2012-01-01

    Full Text Available In a review of the comparative analysis of methods and tools for long-term mechanical circulatory support with continuous flow and pulsatile flow implantable pumps. Particular attention is paid to the choice of the optimal modes of the operation of pumps based on the physical principles of the interaction between a the steady flow of blood to the pulsatile mechanics of the heart chambers. 

  8. Expression mechanisms underlying long-term potentiation: a postsynaptic view, 10 years on

    OpenAIRE

    2014-01-01

    This review focuses on the research that has occurred over the past decade which has solidified a postsynaptic expression mechanism for long-term potentiation (LTP). However, experiments that have suggested a presynaptic component are also summarized. It is argued that the pairing of glutamate uncaging onto single spines with postsynaptic depolarization provides the final and most elegant demonstration of a postsynaptic expression mechanism for NMDA receptor-dependent LTP. The fact that the m...

  9. Mechanisms of long-term weight regain in patients undergoing sleeve gastrectomy.

    Science.gov (United States)

    Alvarez, Veronica; Carrasco, Fernando; Cuevas, Ada; Valenzuela, Barbara; Muñoz, Giselle; Ghiardo, Daniela; Burr, Maria; Lehmann, Yael; Leiva, Maria J; Berry, Marcos; Maluenda, Fernando

    2016-03-01

    Weight regain after bariatric surgery may be associated with behavioral, metabolic, or mechanical factors alone or in combination. The aim of this study was to investigate which factors are related to weight regain in the long-term after sleeve gastrectomy (SG). A retrospective case-control study with 40 patients undergoing SG (32 women, 8 men; age 42.9 ± 10.7 y; preoperative body mass index 35 ± 2.8 kg/m(2)), was performed. Patients were grouped according percentile->50% (cases) or weight regain (%WR cutoff: 25% of weight loss). Weight history, anthropometry, glucose, insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), thyroid-stimulating hormone, resting energy expenditure, body composition, dietary survey, psychological test, and physical activity were recorded. Residual gastric capacity was estimated using a radiologic method. RESULTS (MEDIAN [P25-P75]): The evaluation was conducted 38.5 mo (34-41 mo) after SG. Percent weight regain ranged from 2.7% to 129.2% (25.4% [13-37.1]). Patients in the higher %WR group had a greater residual gastric volume (252.7 ± 108.4 versus 148.5 ± 25.3; P weight regain after SG was residual gastric volume. Additional prospective studies with larger numbers of patients are necessary to confirm our results. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale

    Directory of Open Access Journals (Sweden)

    Minna Haavisto

    2014-01-01

    Full Text Available Stable polarization of permanent magnets over the lifetime of the application is an important aspect in electrical machine design. Specification of the long-term stability of magnet material is difficult, since knowledge of the phenomenon is incomplete. To be able to optimize magnet material selection, the long-term magnetic behavior of the material must also be understood. This study shows that material with a very square JH curve is stable until a certain critical operating temperature is reached. Major losses are detected as the critical temperature is exceeded. Material with a rounder JH curve does not show a well-defined critical temperature, but increasing losses over a large temperature range. The critical temperature of a material is also dependent on the field conditions. Results differ whether the tests are performed in an open or closed magnetic circuit. In open-circuit tests, the opposing field is not homogeneously distributed throughout the volume of the magnet and thus the long-term behavior is different than that in closed-circuit conditions. Open-circuit tests seem to give bigger losses than closed-circuit tests in cases where the permeance coefficient of the open-circuit sample is considered to be the average permeance coefficient, calculated according to the dimensions of the magnet.

  11. An expectancy-value theory approach to the long-term modification of smoking behavior.

    Science.gov (United States)

    Rogers, R W; Deckner, C W; Mewborn, C R

    1978-04-01

    Despite the research interest in modifying smoking behavior, therapeutic treatments that can produce long-term cessation have not been demonstrated rigorously. A follow-up study of two attitude change experiments (N = 173) examined the effects of a fear appeal, that is, increasing smokers' awareness and appreciation of the highly noxious consequences of smoking. Although this familiar type of information may be an integral component of many smoking treatment programs, its long-term suppressive effect has not been demonstrated in well-controlled experiments. The results disclosed that 3 months and also 1 year after treatment, a high-fear manipulation had increased significantly the percentage of smokers who were able to stop smoking completely.

  12. Decoupling the short- and long-term behavior of stochastic volatility

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Lunde, Asger; Pakkanen, Mikko

    behavior) from long memory and persistence (long-term behavior) in a simple and parsimonious way, which allows us to successfully model volatility at all intraday time scales. Our prime model is based on the so-called Brownian semistationary process and we derive a number of theoretical properties...... measures of close to two thousand individual US equities, we find that both roughness and persistence appear to be universal properties of volatility. Inspired by the empirical findings, we introduce a new class of continuous-time stochastic volatility models, capable of decoupling roughness (short-term...

  13. Long-term effects of prevention and treatment on youth antisocial behavior: A meta-analysis.

    Science.gov (United States)

    Sawyer, Aaron M; Borduin, Charles M; Dopp, Alex R

    2015-12-01

    Youth antisocial behavior exacts a tremendous toll on society and often persists into adulthood. Although researchers have identified a number of psychosocial interventions that prevent or reduce youth antisocial behavior in the short term, evidence of long-term intervention benefits has only recently become available. In addition, research on such interventions spans two substantial but largely separate bodies of literature: prevention and therapy. The present study used meta-analysis to integrate research on the long-term effects of preventive and therapeutic interventions for youth antisocial behavior and examined potential moderators of these effects. Results from 66 intervention trials (i.e., 34 prevention, 32 therapy) indicated that a broad range of youth psychosocial interventions demonstrated modest effects on antisocial behavior (mean d=0.31, 95% confidence interval=0.23-0.39) for at least one year beyond the end of interventions relative to control conditions. Among other findings, moderator analyses revealed that inclusion of a peer group intervention component was associated with reduced intervention effects for samples consisting predominantly of boys or older youths. The results of this study have important implications for service providers, administrators, and policymakers involved in the implementation of preventive and therapeutic interventions targeting youth antisocial behavior.

  14. Perinatal nutrition programs neuroimmune function long-term: mechanisms and implications

    Directory of Open Access Journals (Sweden)

    Sarah J Spencer

    2013-08-01

    Full Text Available Our early life nutritional environment can influence several aspects of physiology, including our propensity to become obese. There is now evidence to suggest perinatal diet can also independently influence development of our innate immune system. This review will address three not-necessarily-exclusive mechanisms by which perinatal nutrition can program neuroimmune function long-term: by predisposing the individual to obesity, by altering the gut microbiota, and by inducing epigenetic modifications that alter gene transcription throughout life.

  15. Effect of Long Term Service at Elevated Temperatures on Mechanical Properties of Manaurite XM Reformer Tubes

    Directory of Open Access Journals (Sweden)

    Łabanowski J.

    2016-12-01

    Full Text Available Microstructure transformations occur in the Manaurite XM cast steel tubes during long-term operation in the reformer furnace were revealed and described. The relationship between mechanical properties, an increase of internal diameter of the tube and microstructure degradation is discussed. Static tensile test was performed on two types of samples with different shapes. It has been shown differences in the results of tests and an explanation of this phenomenon.

  16. Effect of Long Term Service at Elevated Temperatures on Mechanical Properties of Manaurite XM Reformer Tubes

    OpenAIRE

    Łabanowski J.; Jurkowski M.; Landowski M.

    2016-01-01

    Microstructure transformations occur in the Manaurite XM cast steel tubes during long-term operation in the reformer furnace were revealed and described. The relationship between mechanical properties, an increase of internal diameter of the tube and microstructure degradation is discussed. Static tensile test was performed on two types of samples with different shapes. It has been shown differences in the results of tests and an explanation of this phenomenon.

  17. Assessment of factors that influence weaning from long-term mechanical ventilation after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Emília Nozawa

    2003-03-01

    Full Text Available OBJECTIVE: To analyze parameters of respiratory system mechanics and oxygenation and cardiovascular alterations involved in weaning tracheostomized patients from long-term mechanical ventilation after cardiac surgery. METHODS: We studied 45 patients in their postoperative period of cardiac surgery, who required long-term mechanical ventilation for more than 10 days and had to undergo tracheostomy due to unsuccessful weaning from mechanical ventilation. The parameters of respiratory system mechanics, oxigenation and the following factors were analyzed: type of surgical procedure, presence of cardiac dysfunction, time of extracorporeal circulation, and presence of neurologic lesions. RESULTS: Of the 45 patients studied, successful weaning from mechanical ventilation was achieved in 22 patients, while the procedure was unsuccessful in 23 patients. No statistically significant difference was observed between the groups in regard to static pulmonary compliance (p=0.23, airway resistance (p=0.21, and the dead space/tidal volume ratio (p=0.54. No difference was also observed in regard to the variables PaO2/FiO2 ratio (p=0.86, rapid and superficial respiration index (p=0.48, and carbon dioxide arterial pressure (p=0.86. Cardiac dysfunction and time of extracorporeal circulation showed a significant difference. CONCLUSION: Data on respiratory system mechanics and oxygenation were not parameters for assessing the success or failure. Cardiac dysfunction and time of cardiopulmonary bypass, however, significantly interfered with the success in weaning patients from mechanical ventilation.

  18. Synthesis on the long term behavior of spent nuclear fuel. Vol.1,2; Synthese sur l'evolution a long terme des colis de combustibles irradies. Tome 1,2

    Energy Technology Data Exchange (ETDEWEB)

    Poinssot, Ch.; Toulhoat, P.; Grouiller, J.P.; Pavageau, J.; Piron, J.P.; Pelletier, M.; Dehaudt, Ph.; Cappelaere, Ch.; Limon, R.; Desgranges, L.; Jegou, Ch.; Corbel, C.; Maillard, S.; Faure, M.H.; Cicariello, J.C.; Masson, M. [CEA Saclay, DEN/DDIN/DPRGD, 91 - Gif sur Yvette (France)

    2001-07-01

    The aim of this report is to present the major objectives, the key scientific issues, and the preliminary results of the research conducted in France in the framework of the third line of the 1991 Law, on the topic of the long term behavior of spent nuclear fuel in view of long term storage or geological disposal. Indeed, CEA launched in 1998 the Research Program on the Long Term Behavior of Spent Nuclear Fuel (abbreviated and referred to as PRECCI in French; Poinssot, 1998) the aim of which is to study and assess the ability of spent nuclear fuel packages to keep their initially allocated functions in interim storage and geological disposal: total containment and recovery functions for duration up to hundreds of years (long term or short-term interim storage and/or first reversible stages of geological disposal) and partial confinement function (controlled fluxes of RN) for thousands of years in geological disposal. This program has to allow to obtain relevant and reliable data concerning the long term behavior of the spent fuel packages so that feasibility of interim storage and/or geological disposal can be assessed and demonstrated as well as optimized. Within this framework, this report presents for every possible scenario of evolution (closed system, in Presence of water in presence of gases) what are estimated to be the most relevant evolution mechanism. For the most relevant scientific issues hence defined, a complete scientific review of the best state of knowledge is subsequently here given thus allowing to draw a clear guideline of the major R and D issues for the next years. (authors)

  19. Long-Term Cognitive and Behavioral Outcomes following Resolution of Sleep Disordered Breathing in Preschool Children.

    Directory of Open Access Journals (Sweden)

    Sarah N Biggs

    Full Text Available This study aimed to determine the long term effects of resolution of SDB in preschool children, either following treatment or spontaneous recovery, on cognition and behavior. Children diagnosed with SDB at 3-5y (N = 35 and non-snoring controls (N = 25, underwent repeat polysomnography (PSG and cognitive and behavioral assessment 3 years following a baseline study. At follow-up, children with SDB were grouped into Resolved and Unresolved. Resolution was defined as: obstructive apnea hypopnea index (OAHI ≤1 event/h; no snoring detected on PSG; and no parental report of habitual snoring. 57% (20/35 of children with SDB received treatment, with SDB resolving in 60% (12/20. 43% (15/35 were untreated, of whom 40% (6/15 had spontaneous resolution of SDB. Cognitive reduced between baseline and follow-up, however this was not related to persistent disease, with no difference in cognitive outcomes between Resolved, Unresolved or Control groups. Behavioral functioning remained significantly worse in children originally diagnosed with SDB compared to control children, regardless of resolution. Change in OAHI did not predict cognitive or behavioral outcomes, however a reduction in nocturnal arousals, irrespective of full resolution, was associated with improvement in attention and aggressive behavior. These results suggest that resolution of SDB in preschool children has little effect on cognitive or behavioral outcomes over the long term. The association between sleep fragmentation and behavior appears independent of SDB, however may be moderated by concomitant SDB. This challenges the assumption that treatment of SDB will ameliorate associated cognitive and behavioural deficits and supports the possibility of a SDB phenotype.

  20. Long-Term Cognitive and Behavioral Outcomes following Resolution of Sleep Disordered Breathing in Preschool Children

    Science.gov (United States)

    Biggs, Sarah N.; Walter, Lisa M.; Jackman, Angela R.; Nisbet, Lauren C.; Weichard, Aidan J.; Hollis, Samantha L.; Davey, Margot J.; Anderson, Vicki; Nixon, Gillian M.; Horne, Rosemary S. C.

    2015-01-01

    This study aimed to determine the long term effects of resolution of SDB in preschool children, either following treatment or spontaneous recovery, on cognition and behavior. Children diagnosed with SDB at 3-5y (N = 35) and non-snoring controls (N = 25), underwent repeat polysomnography (PSG) and cognitive and behavioral assessment 3 years following a baseline study. At follow-up, children with SDB were grouped into Resolved and Unresolved. Resolution was defined as: obstructive apnea hypopnea index (OAHI) ≤1 event/h; no snoring detected on PSG; and no parental report of habitual snoring. 57% (20/35) of children with SDB received treatment, with SDB resolving in 60% (12/20). 43% (15/35) were untreated, of whom 40% (6/15) had spontaneous resolution of SDB. Cognitive reduced between baseline and follow-up, however this was not related to persistent disease, with no difference in cognitive outcomes between Resolved, Unresolved or Control groups. Behavioral functioning remained significantly worse in children originally diagnosed with SDB compared to control children, regardless of resolution. Change in OAHI did not predict cognitive or behavioral outcomes, however a reduction in nocturnal arousals, irrespective of full resolution, was associated with improvement in attention and aggressive behavior. These results suggest that resolution of SDB in preschool children has little effect on cognitive or behavioral outcomes over the long term. The association between sleep fragmentation and behavior appears independent of SDB, however may be moderated by concomitant SDB. This challenges the assumption that treatment of SDB will ameliorate associated cognitive and behavioural deficits and supports the possibility of a SDB phenotype. PMID:26418065

  1. Short-term and long-term behavior of PP-polymer nanocomposites produced by injection molding compounding

    Science.gov (United States)

    Battisti, M. G.; Guttmann, P.; Chitu, L.; Friesenbichler, W.

    2015-05-01

    There are only few investigations considering the impact of nanoscale fillers on the mechanical und thermo-mechanical properties of polymers. Particularly there is a lack of results regarding long term creep behavior of Polypropylene-based polymer nanocomposites (PNCs). Therefore, the objective of this study is to determine the influence of nanofiller content on the mechanical and thermo-mechanical behavior of Polypropylene-based PNCs. Processing of the test specimens was carried out using the Polymer NanoComposite Injection Molding Compounder (PNC-IMC). In comparison to the conventional compounding process, in which the compound must be pelletized and fed into the injection molding machine for the second plasticizing process, injection molding compounding combines these two processing steps. Material compounding and subsequent injection molding are done directly with only one plasticizing process, using a heated melt pipe and a melt accumulator for melt transfer from the compounder to the injection molding machine. The PNCs were produced in the 3-in-1 process at the PNC-IMC, where all components (polymer, compatibilizer, nanofiller) were added simultaneously into the compounder. Furthermore, the polymer melt was treated using elongational flow generating devices for better intercalation and exfoliation of the nanofillers. Tensile tests were made to characterize the short-term-mechanical properties. Tensile creep tests show the influence of nanofillers on the long-term-creep-performance and dynamic mechanical tests (DMA) were performed to investigate the thermo-mechanical behavior. Both, the improvements in the mechanical and thermo-mechanical properties in comparison to the pure polypropylene are shown and give an excellent overview of possibilities and limitations of the PNCs. Further research will focus on the detailed understanding of the different mechanisms of property improvement of layered silicates in polymer. By using small angle X-ray scattering

  2. Long term results of mechanical prostheses for treatment of active infective endocarditis

    Science.gov (United States)

    Guerra, J; Tornos, M; Permanyer-Miralda, G; Almirante, B; Murtra, M; Soler-Soler, J

    2001-01-01

    OBJECTIVE—To analyse the long term results of mechanical prostheses for treating active infective endocarditis.
DESIGN—Prospective cohort study of a consecutive series of patients diagnosed with infective endocarditis and operated on in the active phase of the infection for insertion of a mechanical prosthesis.
SETTING—Tertiary referral centre in a metropolitan area.
RESULTS—Between 1975 and 1997, 637 cases of infective endocarditis were diagnosed in the centre. Of these, 436 were left sided (with overall mortality of 20.3%). Surgical treatment in the active phase of the infection was needed in 141 patients (72% native, 28% prosthetic infective endocarditis). Mechanical prostheses were used in 131 patients. Operative mortality was 30.5% (40 patients). Ninety one survivors were followed up prospectively for (mean (SD)) 5.4 (4.5) years. Thirteen patients developed prosthetic valve dysfunction. Nine patients suffered reinfection: four of these (4%) were early and five were late. The median time from surgery for late reinfection was 1.4 years. During follow up, 12 patients died. Excluding operative mortality, actuarial survival was 86.6% at five years and 83.7% at 10 years; actuarial survival free from death, reoperation, and reinfection was 73.1% at five years and 59.8% at 10 years.
CONCLUSIONS—In patients surviving acute infective endocarditis and receiving mechanical prostheses, the rate of early reinfection compares well with reported results of homografts. In addition, prosthesis dysfunction rate is low and long term survival is good. These data should prove useful for comparison with long term studies, when available, using other types of valve surgery in active infective endocarditis.


Keywords: infective endocarditis; surgery; mechanical prosthesis PMID:11410564

  3. Modeling and characterization of long term material behavior in polymer composites with woven fiber architecture

    Science.gov (United States)

    Gupta, Vikas

    The purpose of this research is to develop an analytical tool which, when coupled with accelerated material characterization, is capable of predicting long-term durability of polymers and their composites. Conducting creep test on each composite laminate with different fibers, fiber volume fractions, and weave architectures is impractical. Moreover, in case of thin laminates, accurately characterizing the out-of-plane matrix dominated viscoelastic response is not easily achievable. Therefore, the primary objective of this paper is to present a multi-scale modeling methodology to simulate the long-term interlaminar properties in polymer matrix woven composites and then predict the critical regions where failure is most likely to occur. A micromechanics approach towards modeling the out-of-plane viscoelastic behavior of a five-harness satin woven-fiber cross-ply composite laminate is presented, taking into consideration the weave architecture and time-dependent effects. Short-term creep tests were performed on neat resin at different test temperatures and stress levels to characterize physical aging of the resin matrix. In addition, creep and recovery experiments were conducted on un-aged resin specimens in order to characterize the pronounced stress-dependent nonlinear viscoelastic response of the PR500 resin. Two-dimensional micromechanics analysis was carried out using a test-bed finite element code, NOVA-3D, including interactions between non-linear material constitutive behavior, geometric nonlinearity, aging and environmental effects.

  4. Long-term evaluation of the degradation behavior of three apatite-forming calcium phosphate cements.

    Science.gov (United States)

    An, Jie; Liao, Hongbing; Kucko, Nathan W; Herber, Ralf-Peter; Wolke, Joop G C; van den Beucken, Jeroen J J P; Jansen, John A; Leeuwenburgh, Sander C G

    2016-05-01

    Calcium phosphate cements (CPCs) are injectable bone substitutes with a long clinical history because of their biocompatibility and osteoconductivity. Nevertheless, their cohesion upon injection into perfused bone defects as well as their long-term degradation behavior remain major clinical challenges. Therefore, the long-term degradation behavior of two types of α-tricalcium phosphate-based, apatite-forming CPCs was compared to a commercially available apatite-forming cement, that is HydroSet™ . Carboxyl methylcellulose (CMC) was used as cohesion promotor to improve handling properties of the two experimental cements, whereas poly (d, l-lactic-co-glycolic) acid (PLGA) microparticles were added to introduce macroporosity and stimulate CPC degradation. All three CPCs were injected into defects drilled into rabbit femoral condyles and explanted after 4, 12, or 26 weeks, after which the bone response was assessed both qualitatively and quantitatively. CPCs without PLGA microparticles degraded only at the periphery of the implants, while the residual CPC volume was close to 90%. On the contrary, bone ingrowth was observed not only at the periphery of the CPC, but also throughout the center of the implants after 26 weeks of implantation for the PLGA-containing CPCs with a residual CPC volume of approximately 55%. In conclusion, it was shown that CPC containing CMC and PLGA was able to induce partial degradation of apatite-forming CPCs and concomitant replacement by bone tissue.

  5. An international initiative on long-term behavior of high-level nuclear waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Gin, Stephane [CEA Marcoule DTCD SECM LCLT, Bagnols/Ceze (France); Abdelouas, Abdessalam [SUBATECH, Nantes (France); Criscenti, Louise J. [Sandia National Laboratories, Albuquerque, NM (United States); Ebert, W. L. [Argonne National Laboratory (ANL), Argonne, IL (United States); Ferrand, Karine [SCK·CEN, Mol (Belgium); Geisler, Thorsten [Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany); Harrison, Mike T. [National Nuclear Laboratory, Sellafield, Cumbria (United Kingdom); Inagaki, Yaohiro [Kyushu Univ. (Japan). Dept. Appl. Quantum Physics and Nuclear Engineering; Mitsui, Seiichiro [Japan Atomic Energy Agency, Ibaraki (Japan); Mueller, Karl T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Environmental and Molecular Science Lab.; Marra, James C. [Savannah River National Laboratory, Aiken, SC (United States); Pantano, Carlo G. [Penn State Univ., State College, PA (United States); Pierce, Eric M. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Schofield, James M. [AMEC, Harwell Oxford (United Kingdom); Steefel, Carl I. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Vienna, John D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2013-06-01

    Nations producing borosilicate glass as an immobilization material for radioactive wastes resulting from spent nuclear fuel reprocessing have reinforced scientific collaboration to obtain consensus on mechanisms controlling the long-term dissolution rate of glass. This goal is deemed to be crucial for the development of reliable performance assessment models for geological disposal. The collaborating laboratories all conduct fundamental and/or applied research with modern materials science techniques. The paper briefly reviews the radioactive waste vitrification programmes of the six participant nations and summarizes the state-of-the-art of glass corrosion science, emphasizing common scientific needs and justifications for on-going initiatives.

  6. An international initiative on long-term behavior of high-level nuclear waste glass

    Directory of Open Access Journals (Sweden)

    S. Gin

    2013-06-01

    Full Text Available Nations using borosilicate glass as an immobilization material for radioactive waste have reinforced the importance of scientific collaboration to obtain a consensus on the mechanisms controlling the long-term dissolution rate of glass. This goal is deemed to be crucial for the development of reliable performance assessment models for geological disposal. The collaborating laboratories all conduct fundamental and/or applied research using modern materials science techniques. This paper briefly reviews the radioactive waste vitrification programs of the six participant nations and summarizes the current state of glass corrosion science, emphasizing the common scientific needs and justifications for on-going initiatives.

  7. The effects of long-term dopaminergic treatment on locomotor behavior in rats

    Directory of Open Access Journals (Sweden)

    Welinton Alessandro Oliveira de Almeida

    2014-12-01

    Full Text Available Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL and drug (Pramipexole—PPX groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions.

  8. The effects of long-term dopaminergic treatment on locomotor behavior in rats

    Science.gov (United States)

    Oliveira de Almeida, Welinton Alessandro; Maculano Esteves, Andrea; Leite de Almeida-Júnior, Canuto; Lee, Kil Sun; Kannebley Frank, Miriam; Oliveira Mariano, Melise; Frussa-Filho, Roberto; Tufik, Sergio; Tulio de Mello, Marco

    2014-01-01

    Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder) symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL) and drug (Pramipexole—PPX) groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions. PMID:26483930

  9. Chronic dietary chlorpyrifos causes long-term spatial memory impairment and thigmotaxic behavior.

    Science.gov (United States)

    López-Granero, Caridad; Ruiz-Muñoz, Ana M; Nieto-Escámez, Francisco A; Colomina, María T; Aschner, Michael; Sánchez-Santed, Fernando

    2016-03-01

    Little is known about the long-term effects of chronic exposure to low-level organophosphate (OP) pesticides, and the role of neurotransmitter systems, other than the cholinergic system, in mediating OP neurotoxicity. In this study, rats were administered 5mg/kg/day of chlorpyrifos (CPF) for 6 months commencing at 3-months-of-age. The animals were examined 7 months later (at 16-months-of-age) for spatial learning and memory in the Morris water maze (MWM) and locomotor activity. In addition, we assessed the chronic effects of CPF on glutamatergic and gamma-aminobutyric acid (GABAergic) function using pharmacological challenges with dizocilpine (MK801) and diazepam. Impaired performance related to altered search patterns, including thigmotaxis and long-term spatial memory was noted in the MWM in animals exposed to CPF, pointing to dietary CPF-induced behavioral disturbances, such as anxiety. Twenty-four hours after the 31st session of repeated acquisition task, 0.1mg/kg MK801, an N-methyl-d-aspartate (NMDA) antagonist was intraperitoneally (i.p.) injected for 4 consecutive days. Decreased latencies in the MWM in the control group were noted after two sessions with MK801 treatment. Once the MWM assessment was completed, animals were administered 0.1 or 0.2mg/kg of MK801 and 1 or 3mg/kg of diazepam i.p., and tested for locomotor activity. Both groups, the CPF dietary and control, displayed analogous performance in motor activity. In conclusion, our data point to a connection between the long-term spatial memory, thigmotaxic response and CPF long after the exposure ended. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Magnetic approaches to study collective three-dimensional cell mechanics in long-term cultures (invited).

    Science.gov (United States)

    Zhao, Ruogang; Boudou, Thomas; Wang, Wei-Gang; Chen, Christopher S; Reich, Daniel H

    2014-05-07

    Contractile forces generated by cells and the stiffness of the surrounding extracellular matrix are two central mechanical factors that regulate cell function. To characterize the dynamic evolution of these two mechanical parameters during tissue morphogenesis, we developed a magnetically actuated micro-mechanical testing system in which fibroblast-populated collagen microtissues formed spontaneously in arrays of microwells that each contains a pair of elastomeric microcantilevers. We characterized the magnetic actuation performance of this system and evaluated its capacity to support long-term cell culture. We showed that cells in the microtissues remained viable during prolonged culture periods of up to 15 days, and that the mechanical properties of the microtissues reached and maintained at a stable state after a fast initial increase stage. Together, these findings demonstrate the utility of this microfabricated bio-magneto-mechanical system in extended mechanobiological studies in a physiologically relevant 3D environment.

  11. Making synapses strong: metaplasticity prolongs associativity of long-term memory by switching synaptic tag mechanisms.

    Science.gov (United States)

    Li, Qin; Rothkegel, Martin; Xiao, Zhi Cheng; Abraham, Wickliffe C; Korte, Martin; Sajikumar, Sreedharan

    2014-02-01

    One conceptual mechanism for the induction of associative long-term memory is that a synaptic tag, set by a weak event, can capture plasticity-related proteins from a nearby strong input, thus enabling associativity between the 2 (synaptic tagging and capture, STC). So far, STC has been observed for only a limited time of 60 min. Nevertheless, association of weak memory forms can occur beyond this period and its mechanism is not well understood. Here we report that metaplasticity induced by ryanodine receptor activation or synaptic activation of metabotropic glutamate receptors prolongs the durability of the synaptic tag, thus extending the time window for associative interactions mediating storage of long-term memory. We provide evidence that such metaplasticity alters the mechanisms of STC from a CaMKII-mediated (in non-primed STC) to a protein kinase Mzeta (PKMζ)-mediated process (in primed STC). Thus the association of weak synapses with strong synapses in the "late" stage of associative memory formation occurs only through metaplasticity. The results also reveal that the short-lived, CaMKII-mediated tag may contribute to a mechanism for a fragile form of memory while metaplasticity enables a PKMζ-mediated synaptic tag capable of prolonged interactions that induce a more stable form of memory that is resistant to reversal.

  12. Prediction of long-term creep behavior and lifetime of PPC pipe materials by linear extrapolation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The universal creep equation relates creep behavior(ε/εo)to aging time(ta),coefficient of retardation time(β),and intrinsic time(to).The relation was used to treat the creep experimental data for pipe specimens of polypropylene block copelymer(PPC),which were aged for different days(short-term)and tested under different stress levels at a certain temperature.Then unified master lines were constructed with the treated data and curves according to the universal equation.The master straight lines can be used for extrapolation to predict the long-term creep behavior and lifetime of the pipe materials of PPC in the same way as plate materials.

  13. Characterization of short- and long-term mechanical sensitisation following surgical tail amputation in pigs

    DEFF Research Database (Denmark)

    Di Giminiani, Pierpaolo; Edwards, Sandra A.; Malcolm, Emma M.

    2017-01-01

    -term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, ‘short tail’, ‘long tail’). A significant reduction in MNTs one week following surgery suggests...... the occurrence of acute sensitisation. Long-term hypersensitivity was also observed in tail-resected pigs at either two or four months following surgery. Tail amputation in pigs appears to evoke acute and sustained changes in peripheral mechanical sensitivity, which resemble features of neuropathic pain reported...

  14. Metabotropic glutamate receptor-mediated long-term depression: molecular mechanisms.

    Science.gov (United States)

    Gladding, Clare M; Fitzjohn, Stephen M; Molnár, Elek

    2009-12-01

    The ability to modify synaptic transmission between neurons is a fundamental process of the nervous system that is involved in development, learning, and disease. Thus, synaptic plasticity is the ability to bidirectionally modify transmission, where long-term potentiation and long-term depression (LTD) represent the best characterized forms of plasticity. In the hippocampus, two main forms of LTD coexist that are mediated by activation of either N-methyl-d-aspartic acid receptors (NMDARs) or metabotropic glutamate receptors (mGluRs). Compared with NMDAR-LTD, mGluR-LTD is less well understood, but recent advances have started to delineate the underlying mechanisms. mGluR-LTD at CA3:CA1 synapses in the hippocampus can be induced either by synaptic stimulation or by bath application of the group I selective agonist (R,S)-3,5-dihydroxyphenylglycine. Multiple signaling mechanisms have been implicated in mGluR-LTD, illustrating the complexity of this form of plasticity. This review provides an overview of recent studies investigating the molecular mechanisms underlying hippocampal mGluR-LTD. It highlights the role of key molecular components and signaling pathways that are involved in the induction and expression of mGluR-LTD and considers how the different signaling pathways may work together to elicit a persistent reduction in synaptic transmission.

  15. Building Long-term Mechanism of Water Conservancy Development Based on Trust in Rural Communities

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Current situations of water conservancy development in China include:there is serious water shortage and pollution;total water reservoir capacity is large but most are dangerous reservoirs;water is widely distributed and directly serves the masses;business is comprehensive and many fields are involved;projects include public welfare and operating types;great regional difference and problems are varied;utilization methods are extensive and water environment is vulnerable.Based on these situations,this paper analyzes the public goods feature of water resource facilities and management mechanism,and points out that water conservancy development should not merely depend on the market force.Then,it discusses that the influence and trust of transformation period on the whole social members are requirements of new harmonious rural communities,and expounds the necessity of trust for building long-term mechanism for water conservancy development.Finally,it presents policy suggestions:trust is closely connected with benefits of every person,thus developing community trust should begin with every individual;building long-term mechanism for water conservancy development should rely on cultivating highly trust-based rural community shared values.

  16. An opportunistic routing mechanism combined with long-term and short-term metrics for WMN.

    Science.gov (United States)

    Sun, Weifeng; Wang, Haotian; Piao, Xianglan; Qiu, Tie

    2014-01-01

    WMN (wireless mesh network) is a useful wireless multihop network with tremendous research value. The routing strategy decides the performance of network and the quality of transmission. A good routing algorithm will use the whole bandwidth of network and assure the quality of service of traffic. Since the routing metric ETX (expected transmission count) does not assure good quality of wireless links, to improve the routing performance, an opportunistic routing mechanism combined with long-term and short-term metrics for WMN based on OLSR (optimized link state routing) and ETX is proposed in this paper. This mechanism always chooses the highest throughput links to improve the performance of routing over WMN and then reduces the energy consumption of mesh routers. The simulations and analyses show that the opportunistic routing mechanism is better than the mechanism with the metric of ETX.

  17. Reconciling long-term cultural diversity and short-term collective social behavior.

    Science.gov (United States)

    Valori, Luca; Picciolo, Francesco; Allansdottir, Agnes; Garlaschelli, Diego

    2012-01-24

    An outstanding open problem is whether collective social phenomena occurring over short timescales can systematically reduce cultural heterogeneity in the long run, and whether offline and online human interactions contribute differently to the process. Theoretical models suggest that short-term collective behavior and long-term cultural diversity are mutually excluding, since they require very different levels of social influence. The latter jointly depends on two factors: the topology of the underlying social network and the overlap between individuals in multidimensional cultural space. However, while the empirical properties of social networks are intensively studied, little is known about the large-scale organization of real societies in cultural space, so that random input specifications are necessarily used in models. Here we use a large dataset to perform a high-dimensional analysis of the scientific beliefs of thousands of Europeans. We find that interopinion correlations determine a nontrivial ultrametric hierarchy of individuals in cultural space. When empirical data are used as inputs in models, ultrametricity has strong and counterintuitive effects. On short timescales, it facilitates a symmetry-breaking phase transition triggering coordinated social behavior. On long timescales, it suppresses cultural convergence by restricting it within disjoint groups. Moreover, ultrametricity implies that these results are surprisingly robust to modifications of the dynamical rules considered. Thus the empirical distribution of individuals in cultural space appears to systematically optimize the coexistence of short-term collective behavior and long-term cultural diversity, which can be realized simultaneously for the same moderate level of mutual influence in a diverse range of online and offline settings.

  18. Mechanical properties and microstructure of long term thermal aged WWER 440 RPV steel

    Science.gov (United States)

    Kolluri, M.; Kryukov, A.; Magielsen, A. J.; Hähner, P.; Petrosyan, V.; Sevikyan, G.; Szaraz, Z.

    2017-04-01

    The integrity assessment of the Reactor Pressure Vessel (RPV) is essential for the safe and Long Term Operation (LTO) of a Nuclear Power Plant (NPP). Hardening and embrittlement of RPV caused by neutron irradiation and thermal ageing are main reasons for mechanical properties degradation during the operation of an NPP. The thermal ageing-induced degradation of RPV steels becomes more significant with extended operational lives of NPPs. Consequently, the evaluation of thermal ageing effects is important for the structural integrity assessments required for the lifetime extension of NPPs. As a part of NRG's research programme on Structural Materials for safe-LTO of Light Water Reactor (LWR) RPVs, WWER-440 surveillance specimens, which have been thermal aged for 27 years (∼200,000 h) at 290 °C in a surveillance channel of Armenian-NPP, are investigated. Results from the mechanical and microstructural examination of these thermal aged specimens are presented in this article. The results indicate the absence of significant long term thermal ageing effect of 15Cr2MoV-A steel. No age hardening was detected in aged tensile specimens compared with the as-received condition. There is no difference between the impact properties of as-received and thermal aged weld metals. The upper shelf energy of the aged steel remains the same as for the as-received material at a rather high level of about 120 J. The T41 value did not change and was found to be about 10 °C. The microstructure of thermal aged weld, consisting carbides, carbonitrides and manganese-silicon inclusions, did not change significantly compared to as-received state. Grain-boundary segregation of phosphorus in long term aged weld is not significant either which has been confirmed by the absence of intergranular fracture increase in the weld. Negligible hardening and embrittlement observed after such long term thermal ageing is attributed to the optimum chemical composition of 15Cr2MoV-A for high thermal stability.

  19. Long-Term Association Between Developmental Assets and Health Behaviors: An Exploratory Study.

    Science.gov (United States)

    Bleck, Jennifer; DeBate, Rita

    2016-10-01

    Introduction Based on internal and external assets, the positive youth development approach aims to increase the capacity among adolescents to overcome challenges as they transition to adulthood. Developmental assets have been found to be positively associated with academic achievement, a variety of health promoting behaviors, and improved physical and mental health. The purpose of this exploratory study was to assess the long-term association between positive youth developmental assets with health risk and promoting behaviors. Method A continuous scale of developmental assets was created using 30 items from Wave I of the National Longitudinal Study of Adolescent to Adult Health, when participants were in 7th to 12th grades. Health behavior outcomes including cigarette use, substance use, fast food consumption, and physical activity were measured at both Wave III (age 18-26) and Wave IV (age 24-32). Path analysis was employed to assess the relationship between these observed measures. Results The well-fitted path model revealed associations between developmental assets with each health behavior at Wave III. Developmental assets indirectly influenced each health behavior and direct associations were observed between assets with substance use and physical activity at Wave IV. Conclusion Findings provide additional support for the developmental assets approach to adolescent health. Implications include Healthy People 2020 objectives related to tobacco and alcohol use and nutrition and physical activity.

  20. Mechanisms underlying the long-term survival of the monocot Dracaena marginata under drought conditions.

    Science.gov (United States)

    Jupa, Radek; Plichta, Roman; Paschová, Zuzana; Nadezhdina, Nadezhda; Gebauer, Roman

    2017-09-01

    Efficient water management is essential for the survival of vascular plants under drought stress. While interrelations among drought stress, plant anatomy and physiological functions have been described in woody dicots, similar research is very limited for non-palm arborescent and shrubby monocots despite their generally high drought tolerance. In this study, potted transplants of Dracaena marginata Lam. in primary growth stage were exposed to several short- and long-term drought periods. Continuous measurements of sap flow and stem diameter, the evaluation of capacitance and leaf conductance, the quantification of non-structural carbohydrates (NSC), and organ-specific anatomical analyses were performed to reveal the mechanisms promoting plant resistance to limited soil moisture. The plants showed sensitive stomata regulation in the face of drying soil, but only intermediate resistance to water loss through cuticular transpiration. The water losses were compensated by water release from stem characterized by densely interconnected, parenchyma-rich ground tissue and considerable hydraulic capacitance. Our results suggest that the high concentration of osmotically active NSC in aboveground organs combined with the production of root pressures supported water uptake and the restoration of depleted reserves after watering. The described anatomical features and physiological mechanisms impart D. marginata with high resistance to irregular watering and long-term water scarcity. These findings should help to improve predictions with respect to the impacts of droughts on this plant group. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Calibrating and validating a FE model for long-term behavior of RC beams

    Directory of Open Access Journals (Sweden)

    Tošić Nikola D.

    2014-01-01

    Full Text Available This study presents the research carried out in finding an optimal finite element (FE model for calculating the long-term behavior of reinforced concrete (RC beams. A multi-purpose finite element software DIANA was used. A benchmark test in the form of a simply supported beam loaded in four point bending was selected for model calibration. The result was the choice of 3-node beam elements, a multi-directional fixed crack model with constant stress cut-off, nonlinear tension softening and constant shear retention and a creep and shrinkage model according to CEB-FIP Model Code 1990. The model was then validated on 14 simply supported beams and 6 continuous beams. Good agreement was found with experimental results (within ±15%.

  2. Long-term transport behavior of psychoactive compounds in sewage-affected groundwater

    Science.gov (United States)

    Nham, Hang Thuy Thi; Greskowiak, Janek; Hamann, Enrico; Meffe, Raffaella; Hass, Ulrike; Massmann, Gudrun

    2016-11-01

    The present study provides a model-based characterization of the long-term transport behavior of five psychoactive compounds (meprobamate, pyrithyldione, primidone, phenobarbital and phenylethylmalonamide) introduced into groundwater via sewage irrigation in Berlin, Germany. Compounds are still present in the groundwater despite the sewage farm closure in the year 1980. Due to the limited information on (i) compound concentrations in the source water and (ii) substance properties, a total of 180 cross-sectional model realizations for each compound were carried out, covering a large range of possible parameter combinations. Results were compared with the present-day contamination patterns in the aquifer and the most likely scenarios were identified based on a number of model performance criteria. The simulation results show that (i) compounds are highly persistent under the present field conditions, and (ii) sorption is insignificant. Thus, back-diffusion from low permeability zones appears as the main reason for the compound retardation.

  3. Long-term behavior of a cyclic max-type system of difference equations

    Directory of Open Access Journals (Sweden)

    Tatjana Stevic

    2015-09-01

    Full Text Available We study the long-term behavior of positive solutions of the cyclic system of difference equations $$ x^{(i}_{n+1}=\\max\\Big\\{\\alpha,\\frac{(x^{(i+1}_n^p}{(x^{(i+2}_{n-1}^q}\\Big\\}, \\quad i=1,\\ldots,k,\\; n\\in\\mathbb{N}_0, $$ where $k\\in\\mathbb{N}$, $\\min\\{\\alpha, p, q\\}>0$ and where we regard that $x^{(i_1}_n=x^{(i_2}_n$ when $i_1\\equiv i_2$ (mod $k$. We determine the set of parameters $\\alpha$, p and q in $(0,\\infty^3$ for which all such solutions are bounded. In the other cases we show that the system has unbounded solutions. For the case p=q we give some sufficient conditions which guaranty the convergence of all positive solutions. The main results in this paper generalize and complement some recent ones.

  4. Reconciling long-term cultural diversity and short-term collective social behavior

    CERN Document Server

    Valori, Luca; Allansdottir, Agnes; Garlaschelli, Diego

    2011-01-01

    An outstanding open problem is whether collective social phenomena occurring over short timescales can systematically reduce cultural heterogeneity in the long run, and whether offline and online human interactions contribute differently to the process. Theoretical models suggest that short-term collective behavior and long-term cultural diversity are mutually excluding, since they require very different levels of social influence. The latter jointly depends on two factors: the topology of the underlying social network and the overlap between individuals in multidimensional cultural space. However, while the empirical properties of social networks are well understood, little is known about the large-scale organization of real societies in cultural space, so that random input specifications are necessarily used in models. Here we use a large dataset to perform a high-dimensional analysis of the scientific beliefs of thousands of Europeans. We find that inter-opinion correlations determine a nontrivial ultramet...

  5. [The deformation behavior of human lumbar intervertebral discs subjected to long term axial dynamic compressive forces (author's transl)].

    Science.gov (United States)

    Köller, W; Funke, F; Hartmann, F

    1981-04-01

    49 specimens were studied in 67 axial compression tests; the duration test varied between 2 and 6 hours. All discs showed marked creep; after a big decrease in the first minutes the rate of creep decreases still slightly. Additional the results reveal a decreasing axial deformability with time. In the beginning of a test quickly the viscoelastic behavior alters to such a steady state that the disc behaves more like an elastic body. Loss of mass normally observed after compression tests is due to loss of liquid, but liquid absorption during mechanical load is possible too. The long term biochmechanical behavior is reproducible very well; a second experiment done with the same disc yields nearly the same results.

  6. Long-Term Cyclic Oxidation Behavior of Wrought Commercial Alloys at High Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bingtao Li

    2003-08-05

    The oxidation resistance of a high-temperature alloy is dependent upon sustaining the formation of a protective scale, which is strongly related to the alloying composition and the oxidation condition. The protective oxide scale only provides a finite period of oxidation resistance owing to its eventual breakdown, which is especially accelerated under thermal cycling conditions. This current study focuses on the long-term cyclic oxidation behavior of a number of commercial wrought alloys. The alloys studied were Fe- and Ni-based, containing different levels of minor elements, such as Si, Al, Mn, and Ti. Oxidation testing was conducted at 1000 and 1100 C in still air under both isothermal and thermal cycling conditions (1-day and 7-days). The specific aspects studied were the oxidation behavior of chromia-forming alloys that are used extensively in industry. The current study analyzed the effects of alloying elements, especially the effect of minor element Si, on cyclic oxidation resistance. The behavior of oxide scale growth, scale spallation, subsurface changes, and chromium interdiffusion in the alloy were analyzed in detail. A novel model was developed in the current study to predict the life-time during cyclic oxidation by simulating oxidation kinetics and chromium interdiffusion in the subsurface of chromia-forming alloys.

  7. Comparison of the long-term behavioral effects of neonatal exposure to retigabine or phenobarbital in rats.

    Science.gov (United States)

    Frankel, Sari; Medvedeva, Natalia; Gutherz, Samuel; Kulick, Catherine; Kondratyev, Alexei; Forcelli, Patrick A

    2016-04-01

    Anticonvulsant drugs, when given during vulnerable periods of brain development, can have long-lasting consequences on nervous system function. In rats, the second postnatal week approximately corresponds to the late third trimester of gestation/early infancy in humans. Exposure to phenobarbital during this period has been associated with deficits in learning and memory, anxiety-like behavior, and social behavior, among other domains. Phenobarbital is the most common anticonvulsant drug used in neonatology. Several other drugs, such as lamotrigine, phenytoin, and clonazepam, have also been reported to trigger behavioral changes. A new generation anticonvulsant drug, retigabine, has not previously been evaluated for long-term effects on behavior. Retigabine acts as an activator of KCNQ channels, a mechanism that is unique among anticonvulsants. Here, we examined the effects retigabine exposure from postnatal day (P)7 to P14 on behavior in adult rats. We compared these effects with those produced by phenobarbital (as a positive control) and saline (as a negative control). Motor behavior was assessed by using the open field and rotarod, anxiety-like behavior by the open field, elevated plus maze, and light-dark transition task, and learning/memory by the passive avoidance task; social interactions were assessed in same-treatment pairs, and nociceptive sensitivity was assessed via the tail-flick assay. Motor behavior was unaltered by exposure to either drug. We found that retigabine exposure and phenobarbital exposure both induced increased anxiety-like behavior in adult animals. Phenobarbital, but not retigabine, exposure impaired learning and memory. These drugs also differed in their effects on social behavior, with retigabine-exposed animals displaying greater social interaction than phenobarbital-exposed animals. These results indicate that neonatal retigabine induces a subset of behavioral alterations previously described for other anticonvulsant drugs and extend

  8. Long-Term Fluoride Release from Dental Resins Affects STRO-1+ Cell Behavior.

    Science.gov (United States)

    Calarco, A; Di Salle, A; Tammaro, L; De Luca, I; Mucerino, S; Petillo, O; Riccitiello, F; Vittoria, V; Peluso, G

    2015-08-01

    Fluoride-releasing restorative dental materials can be beneficial to remineralize dentin and help prevent secondary caries. However, the effects of fluoride release from dental materials on the activity of dental pulp stem cells are not known. Here we investigate whether different fluoride release kinetics from dental resins supplemented with modified hydrotalcite (RK-F10) or fluoride-glass filler (RK-FG10) could influence the behavior of a human dental pulp stem cell subpopulation (STRO-1(+) cells) known for its ability to differentiate toward an odontoblast-like phenotype. The 2 resins, characterized by similar physicochemical properties and fluoride content, exhibited different long-term fluoride release kinetics. Our data demonstrate that long-term exposure of STRO-1(+) cells to a continuous release of a low amount of fluoride by RK-F10 increases their migratory response to transforming growth factor β1 (TGF-β1) and stromal cell-derived factor 1 (SDF-1), both important promoters of pulp stem cell recruitment. Moreover, the expression patterns of dentin sialoprotein (dspp), dentin matrix protein 1 (dmp1), osteocalcin (ocn), and matrix extracellular phosphoglycoprotein (mepe) indicate a complete odontoblast-like cell differentiation only when STRO-1(+) cells were cultured on RK-F10. On the contrary, RK-FG10, characterized by an initial fluoride release burst and reduced lifetime of the delivery, did not elicit any significant effect on both STRO-1(+) cell migration and differentiation. Taken together, our results highlight the importance of taking into account fluoride release kinetics in addition to fluoride concentration when designing new fluoride-restorative materials. © International & American Associations for Dental Research 2015.

  9. An empirical approach to predicting long term behavior of metal particle based recording media

    Science.gov (United States)

    Hadad, Allan S.

    1991-01-01

    Alpha iron particles used for magnetic recording are prepared through a series of dehydration and reduction steps of alpha-Fe2O3-H2O resulting in acicular, polycrystalline, body centered cubic (bcc) alpha-Fe particles that are single magnetic domains. Since fine iron particles are pyrophoric by nature, stabilization processes had to be developed in order for iron particles to be considered as a viable recording medium for long term archival (i.e., 25+ years) information storage. The primary means of establishing stability is through passivation or controlled oxidation of the iron particle's surface. Since iron particles used for magnetic recording are small, additional oxidation has a direct impact on performance especially where archival storage of recorded information for long periods of time is important. Further stabilization chemistry/processes had to be developed to guarantee that iron particles could be considered as a viable long term recording medium. In an effort to retard the diffusion of iron ions through the oxide layer, other elements such as silicon, aluminum, and chromium have been added to the base iron to promote more dense scale formation or to alleviate some of the non-stoichiometric behavior of the oxide or both. The presence of water vapor has been shown to disrupt the passive layer, subsequently increasing the oxidation rate of the iron. A study was undertaken to examine the degradation in magnetic properties as a function of both temperature and humidity on silicon-containing iron particles between 50-120 deg C and 3-89 percent relative humidity. The methodology to which experimental data was collected and analyzed leading to predictive capability is discussed.

  10. Response of Simulated Drinking Water Biofilm Mechanical and Structural Properties to Long-Term Disinfectant Exposure.

    Science.gov (United States)

    Shen, Yun; Huang, Conghui; Monroy, Guillermo L; Janjaroen, Dao; Derlon, Nicolas; Lin, Jie; Espinosa-Marzal, Rosa; Morgenroth, Eberhard; Boppart, Stephen A; Ashbolt, Nicholas J; Liu, Wen-Tso; Nguyen, Thanh H

    2016-02-16

    Mechanical and structural properties of biofilms influence the accumulation and release of pathogens in drinking water distribution systems (DWDS). Thus, understanding how long-term residual disinfectants exposure affects biofilm mechanical and structural properties is a necessary aspect for pathogen risk assessment and control. In this study, elastic modulus and structure of groundwater biofilms was monitored by atomic force microscopy (AFM) and optical coherence tomography (OCT) during three months of exposure to monochloramine or free chlorine. After the first month of disinfectant exposure, the mean stiffness of monochloramine- or free-chlorine-treated biofilms was 4 to 9 times higher than those before treatment. Meanwhile, the biofilm thickness decreased from 120 ± 8 μm to 93 ± 6-107 ± 11 μm. The increased surface stiffness and decreased biofilm thickness within the first month of disinfectant exposure was presumably due to the consumption of biomass. However, by the second to third month during disinfectant exposure, the biofilm mean stiffness showed a 2- to 4-fold decrease, and the biofilm thickness increased to 110 ± 7-129 ± 8 μm, suggesting that the biofilms adapted to disinfectant exposure. After three months of the disinfectant exposure process, the disinfected biofilms showed 2-5 times higher mean stiffness (as determined by AFM) and 6-13-fold higher ratios of protein over polysaccharide, as determined by differential staining and confocal laser scanning microscopy (CLSM), than the nondisinfected groundwater biofilms. However, the disinfected biofilms and nondisinfected biofilms showed statistically similar thicknesses (t test, p > 0.05), suggesting that long-term disinfection may not significantly remove net biomass. This study showed how biofilm mechanical and structural properties vary in response to a complex DWDS environment, which will contribute to further research on the risk assessment and control of biofilm-associated-pathogens in DWDS.

  11. Long-term Mechanical Circulatory Support System reliability recommendation by the National Clinical Trial Initiative subcommittee.

    Science.gov (United States)

    Lee, James

    2009-01-01

    The Long-Term Mechanical Circulatory Support (MCS) System Reliability Recommendation was published in the American Society for Artificial Internal Organs (ASAIO) Journal and the Annals of Thoracic Surgery in 1998. At that time, it was stated that the document would be periodically reviewed to assess its timeliness and appropriateness within 5 years. Given the wealth of clinical experience in MCS systems, a new recommendation has been drafted by consensus of a group of representatives from the medical community, academia, industry, and government. The new recommendation describes a reliability test methodology and provides detailed reliability recommendations. In addition, the new recommendation provides additional information and clinical data in appendices that are intended to assist the reliability test engineer in the development of a reliability test that is expected to give improved predictions of clinical reliability compared with past test methods. The appendices are available for download at the ASAIO journal web site at www.asaiojournal.com.

  12. Preadoption adversity and long-term clinical-range behavior problems in adopted Chinese girls.

    Science.gov (United States)

    Tan, Tony Xing; Camras, Linda A; Kim, Eun Sook

    2016-04-01

    In this study, we report findings on the role of preadoption adversity on long-term clinical-range problems in adopted Chinese girls. Four waves (2005, 2007, 2009 and 2011) of problem behavior data on 1,223 adopted Chinese girls (M = 4.86 years, SD = 2.82 in 2005) were collected from the adoptive mothers with the Child Behavior Checklist (CBCL). At Wave 1 (2005), data on the following indicators of preadoption adversity was collected: age at adoption, physical signs/symptoms (e.g., sores) of preadoption adversity, developmental delays at arrival, refusal/avoidance behaviors and crying/clinging behaviors toward adoptive parents during the first 3 weeks of adoption. We found that the percentage of clinical-range internalizing problems was 11.1%, 16.5%, 11.3%, and 16.1% at Wave 1, Wave 2, Wave 3, and Wave 4, respectively; the corresponding percentage of clinical-range externalizing problems was 8.4%, 10.5%, 8.4% and 9.9% respectively; and the corresponding percentage of clinical-range total CBCL problems was 9.3%, 13.0%, 9.8% and 12.6% respectively. Analyses with Mplus showed that controlling for demographic variables, indicators of preadoption adversity, except age at adoption, increased the odds for clinical-range behavior problems. Longitudinal path models revealed that controlling for demographic variables and the children's adjustment status in the previous wave, refusal/avoidance remained significant in predicting clinical-range internalizing, externalizing and total CBCL problems at Wave 2, delays at arrival and signs/symptoms were significant in predicting clinical-range internalizing problems at Wave 3. Overall, adoptees with clinical-range CBCL problems in earlier waves were 9-28 times as likely to show clinical-range CBCL problems in subsequent waves.

  13. Long-Term Refugee Health: Health Behaviors and Outcomes of Cambodian Refugee and Immigrant Women

    Science.gov (United States)

    Nelson-Peterman, Jerusha L.; Toof, Robin; Liang, Sidney L.; Grigg-Saito, Dorcas C.

    2015-01-01

    Refugees in the United States have high rates of chronic disease. Both long-term effects of the refugee experience and adjustment to the U.S. health environment may contribute. While there is significant research on health outcomes of newly resettled refugees and long-term mental health experiences of established refugees, there is currently…

  14. A smart homecage system with 3D tracking for long-term behavioral experiments.

    Science.gov (United States)

    Byunghun Lee; Kiani, Mehdi; Ghovanloo, Maysam

    2014-01-01

    A wirelessly-powered homecage system, called the EnerCage-HC, that is equipped with multi-coil wireless power transfer, closed-loop power control, optical behavioral tracking, and a graphic user interface (GUI) is presented for long-term electrophysiology experiments. The EnerCage-HC system can wirelessly power a mobile unit attached to a small animal subject and also track its behavior in real-time as it is housed inside a standard homecage. The EnerCage-HC system is equipped with one central and four overlapping slanted wire-wound coils (WWCs) with optimal geometries to form 3-and 4-coil power transmission links while operating at 13.56 MHz. Utilizing multi-coil links increases the power transfer efficiency (PTE) compared to conventional 2-coil links and also reduces the number of power amplifiers (PAs) to only one, which significantly reduces the system complexity, cost, and dissipated heat. A Microsoft Kinect installed 90 cm above the homecage localizes the animal position and orientation with 1.6 cm accuracy. An in vivo experiment was conducted on a freely behaving rat by continuously delivering 24 mW to the mobile unit for > 7 hours inside a standard homecage.

  15. Long-Term Flexural Behaviors of GFRP Reinforced Concrete Beams Exposed to Accelerated Aging Exposure Conditions

    Directory of Open Access Journals (Sweden)

    Yeonho Park

    2014-06-01

    Full Text Available This study investigates the impact of accelerated aging conditions on the long-term flexural behavior and ductility of reinforced concrete (RC members with glass fiber-reinforced polymer (GFRP bars (RC-GFRP specimen and steel bars (RC-steel specimen. A total of thirty six specimens were designed with different amounts of reinforcement with three types of reinforcing bars (i.e., helically wrapped GFRP, sand-coated surface GFRP and steel. Eighteen specimens were subjected to sustained loads and accelerated aging conditions (i.e., 47 °C and 80% relative humidity in a chamber. The flexural behavior of specimens under 300-day exposure was compared to that of the companion specimens without experiencing accelerated aging conditions. Results indicate that the accelerated aging conditions reduced flexural capacity in not only RC-steel, but also RC-GFRP specimens, with different rates of reduction. Different types of GFRP reinforcement exhibited different rates of degradation of the flexural capacity when embedded in concrete under the same exposure conditions. Several existing models were compared with experimental results for predicting the deflection and deformability index for specimens. Bischoff and Gross’s model exhibited an excellent prediction of the time-dependent deflections. Except for the deformability index proposed by Jaeger, there was no general trend related to the aging duration. This study recommends the need for further investigation on the prediction of the deformability index.

  16. Modeling the complex and long term swelling behavior of argillaceous rocks

    Institute of Scientific and Technical Information of China (English)

    Doostmohammadi R.; Mutschler Th.; Osan C.

    2011-01-01

    The swelling behavior of argillaceous rocks is a complex phenomenon and has been determined using a lot of indexes in the literature.Determining the required modeling indexes that need to be performed requires expensive tests and extensive time in different laboratories.In some of the cases,it is too difficult to find a relation between the effective variables and swelling potential.This paper suggests a method for modeling the time dependent swelling pressure of argillaceous rocks.The trend of short term swelling potential during the first 3 days of the swelling pressure testing is used for modeling the long term swelling pressure of mudstone that is recorded during months.The artificial neural network (ANN) as a power tool is used for modeling this nonlinear and complex behavior.This method enables predicting the swelling potential of argillaceous rocks when the required indexes and also correlation between them is unattainable.This method facilitates the model of all studied samples under a unique formulation.

  17. Creep characteristic simulation of deep soft rock roadway and long-term mechanical analysis of lining support

    Energy Technology Data Exchange (ETDEWEB)

    Tong-bin Zhao; Yan-hua Ma; Yun-liang Tan; Yun-juan Chen [Shandong University of Science and Technology, Qingdao (China). College of Resource and Environmental Engineering

    2009-06-15

    By the generalized Kelvin creep model, rheological characteristics of deep soft rock and long-term mechanical behaviors of support structures were simulated. Mechanical deformation characteristics of support structures under different lining circumstances were also analyzed on the basis of deducing the relationship between the generalized Kelvin creep model and implicit creep equations in ANSYS FEM software. The results show that high stress of deep tunnels is the main factor in creep damage; the surrounding rock's deformation binding effect due to lining increases as the thickness increases but the effect becomes very weak when it increases to a certain value; contact pressure on the lining decreases as its thickness decreases. 11 refs., 5 figs., 1 tab.

  18. Long-term anisotropic mechanical response of surgical meshes used to repair abdominal wall defects.

    Science.gov (United States)

    Hernández-Gascón, B; Peña, E; Pascual, G; Rodríguez, M; Bellón, J M; Calvo, B

    2012-01-01

    Routine hernia repair surgery involves the implant of synthetic mesh. However, this type of procedure may give rise to pain and bowel incarceration and strangulation, causing considerable patient disability. The purpose of this study was to compare the long-term behaviour of three commercial meshes used to repair the partially herniated abdomen in New Zealand White rabbits: the heavyweight (HW) mesh, Surgipro(®) and lightweight (LW) mesh, Optilene(®), both made of polypropylene (PP), and a mediumweight (MW) mesh, Infinit(®), made of polytetrafluoroethylene (PTFE). The implanted meshes were mechanical and histological assessed at 14, 90 and 180 days post-implant. This behaviour was compared to the anisotropic mechanical behaviour of the unrepaired abdominal wall in control non-operated rabbits. Both uniaxial mechanical tests conducted in craneo-caudal and perpendicular directions and histological findings revealed substantial collagen growth over the repaired hernial defects causing stiffness in the repair zone, and thus a change in the original properties of the meshes. The mechanical behaviour of the healthy tissue in the craneo-caudal direction was not reproduced by any of the implanted meshes after 14 days or 90 days of implant, whereas in the perpendicular direction, SUR and OPT achieved similar behaviour. From a mechanical standpoint, the anisotropic PP-lightweight meshes may be considered a good choice in the long run, which correlates with the structure of the regenerated tissue. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Long-term behavior of glass-ceramic zirconolite; Etude du comportement a long terme des vitrocristallins a base de zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ch

    2003-07-01

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi{sub 2}O{sub 7}) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  20. Evaluation of limiting mechanisms for long-term spent fuel dry storage

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, J. [ANATECH Research Corp., San Diego, CA (United States); Machiels, A. [EPRI, Palo Alto, CA (United States)

    2001-07-01

    Several failure mechanisms have been postulated that could become limiting for spent fuel in dry storage. These are: stress Corrosion Cracking (SCC), Delayed Hydride Cracking (DHC) and Creep Rupture (CR). These mechanisms are examined in some detail from two perspectives: their initial environments in which they were developed and applied, and in relation to their applicability to dry storage. Extrapolation techniques are used to transfer the mechanisms from their initial in-reactor and laboratory domains to out-of-reactor spent fuel dry storage environments. This transfer is accomplished both qualitatively where necessary and quantitatively when possible, with fracture toughness used as the transfer function. In this regard, the paper provides useful information on cladding fracture toughness estimates that recognize the specific physical conditions of the cladding, which would not be found elsewhere in the literature. The arguments presented in this paper confirm the general technical consensus that creep is the governing mechanism for spent fuel in long-term dry storage. (author)

  1. Neural mechanisms underlying the impact of visual distraction on retrieval of long-term memory.

    Science.gov (United States)

    Wais, Peter E; Rubens, Michael T; Boccanfuso, Jacqueline; Gazzaley, Adam

    2010-06-23

    Filtering information on the basis of what is relevant to accomplish our goals is a critical process supporting optimal cognitive performance. However, it is not known whether exposure to irrelevant environmental stimuli impairs our ability to accurately retrieve long-term memories. We hypothesized that visual processing of irrelevant visual information would interfere with mental visualization engaged during recall of the details of a prior experience, despite goals to direct full attention to the retrieval task. In the current study, we compared performance on a cued-recall test of previously studied visual items when participants' eyes were closed to performance when their eyes were open and irrelevant visual stimuli were presented. A behavioral experiment revealed that recollection of episodic details was diminished in the presence of the irrelevant information. A functional magnetic resonance imaging experiment using the same paradigm replicated the behavioral results and found that diminished recollection was associated with the disruption of functional connectivity in a network involving the left inferior frontal gyrus, hippocampus and visual association cortex. Network connectivity supported recollection of contextual details based on visual imagery when eyes were closed, but declined in the presence of irrelevant visual information. We conclude that bottom-up influences from irrelevant visual information interfere with top-down selection of episodic details mediated by a capacity-limited frontal control region, resulting in impaired recollection.

  2. Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

    Science.gov (United States)

    Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

    2011-01-01

    This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

  3. Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

    Science.gov (United States)

    Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

    2011-01-01

    This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

  4. Mechanical properties and microstructure changes after long-term aging at 700℃ for a nickel-base superalloy

    Institute of Scientific and Technical Information of China (English)

    Shuangqun Zhao; Jianxin Dong; Xishan Xie

    2003-01-01

    Mechanical properties and microstructure changes have been investigated on a new nickel-base superalloy after long-term aging at 700℃. It is found that the major precipitates of the tested alloy are MC, M23C6, M6C and γ' in the course of long-term aging at 700℃. The carbides maintain good thermal stability with the aging time up to 5008 h. The growth rate of gamma prime precipitates is relatively high in the early aging period and then slows down. The coarsening behavior of gamma prime follows a diffusion-controlled growth procedure. The room temperature Rockwell hardness of the alloy aged at 700℃ increases slightly at the initial stage of aging, but it decreases with the prolonged time. It mainly depends on the size of gamma prime. In comparison with Nimonic lloy 263, the new alloy characterizes with higher tensile and stress-rupture strengths at high temperatures. The new nickel-base superalloy offers a combination of microstructure stability, strength, ductility and toughness at 700℃.

  5. Long-term management of the fearful adult patient using behavior modification and other modalities.

    Science.gov (United States)

    Berggren, U

    2001-12-01

    This paper reviews reports on the treatment of fearful adult dental patients with special emphasis on behavioral and cognitive methods and long-term followup. A number of such treatment methods are available that can be used by dentists for the alleviation of fear and anxiety in their patients. At an "intuitive" level, many dentists probably use these methods frequently as a comprehensive part of everyday praxis. Considering the high number of fearful individuals visiting dentists regularly, a better knowledge of such methods would improve dental care for the majority of these patients. It would also help prevent aggravation of fears among individuals at risk. However, despite the success of treatment methods performed by specially trained dentists, it seems reasonable that there should be limits to what can be expected of a dentist in terms of psychological, diagnostic, and therapeutic competence. Dental phobia may constitute a complex psychological and odontological problem with far-reaching consequences for a relatively large proportion of fearful individuals. It therefore seems likely that optimal care of such patients can best be achieved by cross-disciplinary efforts involving both dentists and psychologists.

  6. Long-term behavior of refractory thorium-plutonium dioxide solid solutions

    Science.gov (United States)

    Claparede, Laurent; Guigue, Mireille; Jouan, Gauthier; Nadah, Nassima; Dacheux, Nicolas; Moisy, Philippe

    2017-01-01

    The long-term behavior of Th0.87Pu0.13O2 was examined in nitric acid concentrations. The normalized dissolution rates after 3380 days, range from (1.4 ± 0.2) × 10-6 g m-2 d-1 in 5 M HNO3 down to (3.2 ± 0.4) × 10-8 g m-2 d-1 in 10-3 M HNO3, which confirms the high chemical durability of this solid solution. The amounts of plutonium measured in solution lead to 0.9% and 2.1% of dissolved solid in 1 M and 5 M HNO3, respectively. In such conditions, the time required to reach the full dissolution of the material varies from 430 years (5 M HNO3) to 18,000 years (10-3 M HNO3). Moreover, the partial order related to the proton activity (n = 0.45 ± 0.03) suggests that the dissolution is mainly driven by surface reactions occurring at the solid/liquid interface. The characterization of the leached samples by SEM shows small microstructural modifications (i.e. detachment of crystallites) and the absence of neoformed phase while from PXRD, the unit cell parameter and crystallite size are not significantly affected.

  7. Long-term nano-mechanical properties of biomodified dentin-resin interface components.

    Science.gov (United States)

    Dos Santos, Paulo Henrique; Karol, Sachin; Bedran-Russo, Ana Karina

    2011-06-03

    Failures of dental composite restorative procedures are largely attributed to the degradation of dentin-resin interface components. Biomodification of dentin using bioactive agents may improve the quality and durability of the dentin-resin bonds. The aim of this study was to nanomechanically assess the reduced modulus of elasticity (Er) and nano-hardness (H) of major components of the dentin-resin interface (hybrid layer, adhesive layer and underlying dentin) biomodified by collagen cross-linkers at 24h, 3 and 6 months following restorative procedure. Demineralized dentin surfaces were biomodified with 5% glutaraldehyde (GD) or 6.5% grape seed extract (GSE) prior to placement of adhesive systems and composite resin. Nano-measurements of the interface components in a fluid cell showed that both agents increased the Er and H of underlying dentin after 3 and 6 months when compared to a control. The mechanical properties of the adhesive and hybrid layers decreased over time. Biomodification of the dentin-resin interface structures using GD and GSE can increase the mechanical properties of the interface over time and may contribute to the long-term quality of adhesive restorations.

  8. Obesity and pregnancy: mechanisms of short term and long term adverse consequences for mother and child.

    Science.gov (United States)

    Catalano, Patrick M; Shankar, Kartik

    2017-02-08

    Obesity is the most common medical condition in women of reproductive age. Obesity during pregnancy has short term and long term adverse consequences for both mother and child. Obesity causes problems with infertility, and in early gestation it causes spontaneous pregnancy loss and congenital anomalies. Metabolically, obese women have increased insulin resistance in early pregnancy, which becomes manifest clinically in late gestation as glucose intolerance and fetal overgrowth. At term, the risk of cesarean delivery and wound complications is increased. Postpartum, obese women have an increased risk of venous thromboembolism, depression, and difficulty with breast feeding. Because 50-60% of overweight or obese women gain more than recommended by Institute of Medicine gestational weight guidelines, postpartum weight retention increases future cardiometabolic risks and prepregnancy obesity in subsequent pregnancies. Neonates of obese women have increased body fat at birth, which increases the risk of childhood obesity. Although there is no unifying mechanism responsible for the adverse perinatal outcomes associated with maternal obesity, on the basis of the available data, increased prepregnancy maternal insulin resistance and accompanying hyperinsulinemia, inflammation, and oxidative stress seem to contribute to early placental and fetal dysfunction. We will review the pathophysiology underlying these data and try to shed light on the specific underlying mechanisms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. A novel whole-cell mechanism for long-term memory enhancement.

    Directory of Open Access Journals (Sweden)

    Iris Reuveni

    Full Text Available Olfactory-discrimination learning was shown to induce a profound long-lasting enhancement in the strength of excitatory and inhibitory synapses of pyramidal neurons in the piriform cortex. Notably, such enhancement was mostly pronounced in a sub-group of neurons, entailing about a quarter of the cell population. Here we first show that the prominent enhancement in the subset of cells is due to a process in which all excitatory synapses doubled their strength and that this increase was mediated by a single process in which the AMPA channel conductance was doubled. Moreover, using a neuronal-network model, we show how such a multiplicative whole-cell synaptic strengthening in a sub-group of cells that form a memory pattern, sub-serves a profound selective enhancement of this memory. Network modeling further predicts that synaptic inhibition should be modified by complex learning in a manner that much resembles synaptic excitation. Indeed, in a subset of neurons all GABAA-receptors mediated inhibitory synapses also doubled their strength after learning. Like synaptic excitation, Synaptic inhibition is also enhanced by two-fold increase of the single channel conductance. These findings suggest that crucial learning induces a multiplicative increase in strength of all excitatory and inhibitory synapses in a subset of cells, and that such an increase can serve as a long-term whole-cell mechanism to profoundly enhance an existing Hebbian-type memory. This mechanism does not act as synaptic plasticity mechanism that underlies memory formation but rather enhances the response of already existing memory. This mechanism is cell-specific rather than synapse-specific; it modifies the channel conductance rather than the number of channels and thus has the potential to be readily induced and un-induced by whole-cell transduction mechanisms.

  10. Institutional Care for Long-Term Mechanical Ventilation in Canada: A National Survey

    Directory of Open Access Journals (Sweden)

    Louise Rose

    2014-01-01

    Full Text Available INTRODUCTION: No national Canadian data define resource requirements and care delivery for ventilator-assisted individuals (VAIs requiring long-term institutional care. Such data will assist in planning health care services to this population.

  11. Metabotropic Glutamate Receptor-Mediated Long-Term Depression: Molecular Mechanisms

    OpenAIRE

    Gladding, Clare M.; Fitzjohn, Stephen M; Molnár, Elek

    2009-01-01

    The ability to modify synaptic transmission between neurons is a fundamental process of the nervous system that is involved in development, learning, and disease. Thus, synaptic plasticity is the ability to bidirectionally modify transmission, where long-term potentiation and long-term depression (LTD) represent the best characterized forms of plasticity. In the hippocampus, two main forms of LTD coexist that are mediated by activation of either N-methyl-d-aspartic acid receptors (NMDARs) or ...

  12. Repeated mild lateral fluid percussion brain injury in the rat causes cumulative long-term behavioral impairments, neuroinflammation, and cortical loss in an animal model of repeated concussion.

    Science.gov (United States)

    Shultz, Sandy R; Bao, Feng; Omana, Vanessa; Chiu, Charlotte; Brown, Arthur; Cain, Donald Peter

    2012-01-20

    There is growing evidence that repeated brain concussion can result in cumulative and long-term behavioral symptoms, neuropathological changes, and neurodegeneration. Little is known about the factors and mechanisms that contribute to these effects. The current study addresses the need to investigate and better understand the effects of repeated concussion through the development of an animal model. Male Long-Evans rats received 1, 3, or 5 mild lateral fluid percussion injuries or sham injuries spaced 5 days apart. After the final injury, rats received either a short (24 h) or long (8 weeks) post-injury recovery period, followed by a detailed behavioral analysis consisting of tests for rodent anxiety-like behavior, cognition, social behavior, sensorimotor function, and depression-like behavior. Brains were examined immunohistochemically to assess neuroinflammation and cortical damage. Rats given 1, 3, or 5 mild percussion injuries displayed significant short-term cognitive impairments. Rats given repeated mild percussion injuries displayed significantly worse short- and long-term cognitive impairments. Rats given 5 mild percussion injuries also displayed increased anxiety- and depression-like behaviors. Neuropathological analysis revealed short-term neuroinflammation in 3-injury rats, and both short- and long-term neuroinflammation in 5-injury rats. There was also evidence that repeated injuries induced short- and long-term cortical damage. These cumulative and long-term changes are consistent with findings in human patients suffering repeated brain concussion, provide support for the use of repeated mild lateral fluid percussion injuries to study repeated concussion in the rat, and suggest that neuroinflammation may be important for understanding the cumulative and chronic effects of repeated concussion.

  13. Effect of Long-Term Service on Microstructure and Mechanical Properties of Martensitic 9% Cr Steel

    Science.gov (United States)

    Golański, Grzegorz; Zielińska-Lipiec, Anna; Zieliński, Adam; Sroka, Marek

    2017-02-01

    The paper presents the results of research on the X10CrMoVNbN9-1 (T91) steel after long-term service. The material for testing was taken from a pipe section of a boiler superheater coil serviced for around 105,000 h at the temperature of 540 °C, at the pressure of 12.5 MPa. A quantitative analysis including the measurement of mean diameter of subgrains and precipitates as well as the density of dislocations of the examined steel was performed by means of TEM. The microscopic tests of T91 steel were complemented with the results of tests on mechanical properties which included also the short creep tests. After service, the investigated steel was characterized by a retained lath microstructure of tempered martensite with fine subgrain and quite large density of dislocations as well as numerous precipitates. In the microstructure, apart from the particles of M23C6 and MX (VX, NbC, V-wings), the precipitates of Laves phase and single particles of Z phase were revealed. It has been shown that the extent of degradation of the T91 steel microstructure was minor, which resulted from its low temperature of service. Performed tests of mechanical properties showed that these properties fulfilled the minimum requirements for this steel in the as-received condition. A favorable influence of fine precipitates of Laves phase on mechanical properties was observed. Moreover, an insignificant influence of single precipitates of Z phase on the creep resistance of the examined steel was stated.

  14. Effect of Long-Term Service on Microstructure and Mechanical Properties of Martensitic 9% Cr Steel

    Science.gov (United States)

    Golański, Grzegorz; Zielińska-Lipiec, Anna; Zieliński, Adam; Sroka, Marek

    2017-03-01

    The paper presents the results of research on the X10CrMoVNbN9-1 (T91) steel after long-term service. The material for testing was taken from a pipe section of a boiler superheater coil serviced for around 105,000 h at the temperature of 540 °C, at the pressure of 12.5 MPa. A quantitative analysis including the measurement of mean diameter of subgrains and precipitates as well as the density of dislocations of the examined steel was performed by means of TEM. The microscopic tests of T91 steel were complemented with the results of tests on mechanical properties which included also the short creep tests. After service, the investigated steel was characterized by a retained lath microstructure of tempered martensite with fine subgrain and quite large density of dislocations as well as numerous precipitates. In the microstructure, apart from the particles of M23C6 and MX (VX, NbC, V-wings), the precipitates of Laves phase and single particles of Z phase were revealed. It has been shown that the extent of degradation of the T91 steel microstructure was minor, which resulted from its low temperature of service. Performed tests of mechanical properties showed that these properties fulfilled the minimum requirements for this steel in the as-received condition. A favorable influence of fine precipitates of Laves phase on mechanical properties was observed. Moreover, an insignificant influence of single precipitates of Z phase on the creep resistance of the examined steel was stated.

  15. Long-term Dynamical Behavior of Highly Perturbed Natural and Artificial Celestial Bodies

    Science.gov (United States)

    Rosengren, Aaron J.

    This thesis explores the dynamical evolution of celestial bodies, both natural and artificial, which are strongly perturbed by solar radiation pressure---a non-gravitational force that has played an increasingly important role in celestial mechanics since the early 1900s. The particular focus is on the high area-to-mass ratio (HAMR) space debris discovered in near geosynchronous Earth orbit (GEO) through optical observations in 2004, and on micron-sized circumplanetary dust particles in the outer Saturnian system. The formalism developed can also be applied to---and, indeed, was unquestionably influenced by---the orbital motion of spacecraft about small bodies (asteroids and comets). The chief difficulties which arise in getting an accurate understanding of the motion of such bodies in highly perturbed dynamical environments come, in part, from the nonlinearity of the dynamical system, but more so from the inadequacy of the classical approaches and methods. While modern formulations based on numerical integrations can give "precise" solutions for specific initial conditions, these afford little insight into the nature of the problem or the essential dependence of the perturbed motion on the system parameters. The predominant perturbations acting on HAMR objects and circumplanetary dust grains are solar radiation pressure, planetary oblateness, and third-body gravitational interactions induced by the Sun and nearby natural satellites. We developed first-order averaged models, based on the Milankovitch formulation of perturbation theory, which govern the long-term evolution of orbits subject to these perturbing forces. The unexpectedly rich results obtained by the use of this vector formalism are due to certain important circumstances in celestial and quantum mechanics which gave rise to its origin and development. An attempt has been made to trace these historical developments and to put them into the perspective of the present. The averaged equations of motion hold

  16. Cognitive Behavioral Treatment for Childhood Anxiety Disorders: Long-Term Effects on Anxiety and Secondary Disorders in Young Adulthood

    Science.gov (United States)

    Saavedra, Lissette M.; Silverman, Wendy K.; Morgan-Lopez, Antonio A.; Kurtines, William M.

    2010-01-01

    Background: The present study's aim was to examine the long-term effects (8 to 13 years post-treatment; M = 9.83 years; SD = 1.71) of the most widely used treatment approaches of exposure-based cognitive behavioral treatment for phobic and anxiety disorders in children and adolescents (i.e., group treatment and two variants of individual…

  17. Cognitive Behavioral Treatment for Childhood Anxiety Disorders: Long-Term Effects on Anxiety and Secondary Disorders in Young Adulthood

    Science.gov (United States)

    Saavedra, Lissette M.; Silverman, Wendy K.; Morgan-Lopez, Antonio A.; Kurtines, William M.

    2010-01-01

    Background: The present study's aim was to examine the long-term effects (8 to 13 years post-treatment; M = 9.83 years; SD = 1.71) of the most widely used treatment approaches of exposure-based cognitive behavioral treatment for phobic and anxiety disorders in children and adolescents (i.e., group treatment and two variants of individual…

  18. Long-Term Effects of Ammonia on the Behavioral Activity of the Aquatic Snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)

    NARCIS (Netherlands)

    Alonso, A.; Camargo, J.A.

    2009-01-01

    An appropriate approach to assess the effect of toxicants on aquatic animals is to monitor behavioral endpoints, as they are a link between physiological and ecological processes. A group that can be exposed long-term to low toxic concentrations is benthic macroinvertebrates, as their mobility in aq

  19. Long term behavior of radiocaesium in moose: conclusions from 25 years of monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Weimer, R.; Sonesten, L.; Goedkoop, W. [Department of Aquatic Sciences and Assessment (Sweden); Sundell-Bergman, S.; Rosen, K. [Department of Soil and Environment (Sweden); Wikenros, C. [Department of Ecology (Sweden)

    2014-07-01

    Radiocesium ({sup 137}Cs) deposited after the Chernobyl nuclear disaster in 1986, still persist in forest ecosystems in parts of Sweden at relatively high concentrations. In the forest, radiocaesium is assumed to be reversibly bound to the soil, which facilitates its uptake by plant roots and fungal mycelia thus making it available, as fodder, to wild animals. Even today this leads to contaminated meat from moose (Alces alces) and other game species. Around 100 000 moose, approximately 1/3 of the whole population, are shot each year in Sweden which makes moose the main source of consumed game meat. Hence understanding the long-term behavior of radiocaesium in forest ecosystems is important for the evaluation of future potential health risks to consumers. The two municipalities of Heby and Uppsala, in east-central Sweden, experienced relatively large deposition in 1986 (5 - 100 kBq/m{sup 2}). Monitoring of the {sup 137}Cs activity concentrations in meat from moose hunted in these areas was initiated already in autumn 1986 and is still continuing. Muscle samples from front leg of the slaughtered moose are received from local hunters during the hunting season and more than 3500 samples have been collected during the years. The samples are adjoined with a sampling protocol containing information on estimated age, sex and weight, as well as where and when each moose was shot. Gamma spectrometry of the {sup 137}Cs- activities is performed on fresh or frozen moose muscle samples using HPGe detectors. The main part of all the samples analyzed since 1986 are from the northern part of Heby municipality. This study area covers approximately 400 km{sup 2} and received a mean ground deposition of approximately 35 kBq/m{sup 2} of {sup 137}Cs in 1986. The area is dominated by managed coniferous forests, but also includes large parts of agricultural land. A database of > 3 500 moose samples collected from hunts between 1986 and 2010 was used in this study. The results of the

  20. Prediction of Individual Social-Demographic Role Based on Travel Behavior Variability Using Long-Term GPS Data

    Directory of Open Access Journals (Sweden)

    Lei Zhu

    2017-01-01

    Full Text Available With the development of and advances in smartphones and global positioning system (GPS devices, travelers’ long-term travel behaviors are not impossible to obtain. This study investigates the pattern of individual travel behavior and its correlation with social-demographic features. For different social-demographic groups (e.g., full-time employees and students, the individual travel behavior may have specific temporal-spatial-mobile constraints. The study first extracts the home-based tours, including Home-to-Home and Home-to-Non-Home, from long-term raw GPS data. The travel behavior pattern is then delineated by home-based tour features, such as departure time, destination location entropy, travel time, and driving time ratio. The travel behavior variability describes the variances of travelers’ activity behavior features for an extended period. After that, the variability pattern of an individual’s travel behavior is used for estimating the individual’s social-demographic information, such as social-demographic role, by a supervised learning approach, support vector machine. In this study, a long-term (18-month recorded GPS data set from Puget Sound Regional Council is used. The experiment’s result is very promising. The sensitivity analysis shows that as the number of tours thresholds increases, the variability of most travel behavior features converges, while the prediction performance may not change for the fixed test data.

  1. Prediction of Individual Social-Demographic Role Based on Travel Behavior Variability Using Long-Term GPS Data

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Lei [Transportation and Hydrogen Systems Center, National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, CO 80401, USA; Gonder, Jeffrey [Transportation and Hydrogen Systems Center, National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, CO 80401, USA; Lin, Lei [Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, NY 14260, USA

    2017-01-01

    With the development of and advances in smartphones and global positioning system (GPS) devices, travelers’ long-term travel behaviors are not impossible to obtain. This study investigates the pattern of individual travel behavior and its correlation with social-demographic features. For different social-demographic groups (e.g., full-time employees and students), the individual travel behavior may have specific temporal-spatial-mobile constraints. The study first extracts the home-based tours, including Home-to-Home and Home-to-Non-Home, from long-term raw GPS data. The travel behavior pattern is then delineated by home-based tour features, such as departure time, destination location entropy, travel time, and driving time ratio. The travel behavior variability describes the variances of travelers’ activity behavior features for an extended period. After that, the variability pattern of an individual’s travel behavior is used for estimating the individual’s social-demographic information, such as social-demographic role, by a supervised learning approach, support vector machine. In this study, a long-term (18-month) recorded GPS data set from Puget Sound Regional Council is used. The experiment’s result is very promising. The sensitivity analysis shows that as the number of tours thresholds increases, the variability of most travel behavior features converges, while the prediction performance may not change for the fixed test data.

  2. Experimental observations on long-term behavior of migrating alternate bars

    NARCIS (Netherlands)

    Crosato, A.; Desta, F.B.; Cornelisse, J.; Uijttewaal, W.S.J.

    2011-01-01

    Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether they eventually reach an equ

  3. The long-term mechanically ventilated patient. An outcomes management approach.

    Science.gov (United States)

    Burns, S M

    1998-03-01

    -management model, we recognize that other models may also result in comparable, favorable outcomes. It is important that those who adopt similar models of care delivery for managing patients requiring prolonged ventilation be scientific in their approach. Long-term studies of the efficacy of these models are essential if we are to truly provide quality care for our patients in the future. Unfortunately, as noted earlier, bias will be hard to overcome. Hospitals vested in rapidly establishing a stable financial bottom-line are likely to embrace quick applications. Projects with a true experimental design to evaluate efficacy, such as this one, will be rare in these organizations. Finally, it is critical that variables of interest be inclusive of specific quality indicators such as ventilator duration and complications rather than global institutional markers such as LOS. Standardization of variables of interest is imperative if outcomes are to be compared. For example, patients requiring long-term mechanical ventilation are identified by the AACN's Third National Study Group on weaning as those who require mechanical ventilation for more than 3 days. If we are to compare other variables of interest such as total ventilator duration, such as definition is essential or we will be comparing apples and oranges in the future. Provision of quality, cost-effective care for patients requiring prolonged ventilation is a true clinical challenge. Outcomes management is a multidisciplinary method of care delivery that is systematic and comprehensive in approach. Although little science exists related to the application of the model for patients requiring prolonged ventilation, preliminary reports are promising and warrant future applications and evaluation of the same.

  4. Long-term imipramine treatment increases N-methyl-d-aspartate receptor activity and expression via epigenetic mechanisms.

    Science.gov (United States)

    Nghia, Nguyen An; Hirasawa, Takae; Kasai, Hirotake; Obata, Chie; Moriishi, Kohji; Mochizuki, Kazuki; Koizumi, Schuichi; Kubota, Takeo

    2015-04-05

    Imipramine, a major antidepressant, is known to inhibit reuptake of serotonin and norepinephrine, which contributes to recovery from major depressive disorder. It has recently been reported that acute imipramine treatment inhibits N-methyl-d-aspartate (NMDA) receptor activity. However, the mechanisms underlying long-term effects of imipramine have not been identified. We tested these distinct effects in mouse cortical neurons and found that acute (30s) imipramine treatment decreased Ca(2+) influx through NMDA receptors, whereas long-term treatment (48h) increased Ca(2+) influx via the same receptors. Furthermore, long-term treatment increased NMDA receptor 2B (NR2B) subunit expression via epigenetic changes, including increased acetylation of histones H3K9 and H3K27 in the NR2B promoter and decreased activity of histone deacetylase 3 (HDAC3) and HDAC4. These results suggest that the long-term effects of imipramine on NMDA receptors are quite different from its acute effects. Furthermore, increased NR2B expression via epigenetic alterations might be a part of the mechanism responsible for this long-term effect.

  5. The role of short- and long-term cognitive empathy activation in preventing cyberbystander reinforcing cyberbullying behavior.

    Science.gov (United States)

    Barlińska, Julia; Szuster, Anna; Winiewski, Mikołaj

    2015-04-01

    The long- versus short-term effectiveness of empathy activation on reducing bystander behavior reinforcing cyberbullying was tested. The focus was on limiting the frequency of forwarding a message ridiculing a peer. Experimental research on adolescent students was conducted in conditions simulating online contact. The results confirmed the significance of cognitive empathy activated immediately prior to decision making on limiting involvement in reinforcing cyberbullying behavior. The long-term impact of empathy was markedly limited.

  6. Obesity and pregnancy: Mechanisms of short term and long term adverse consequences for mother and child

    Science.gov (United States)

    Obesity is the most common medical condition in women of reproductive age. Obesity during pregnancy has short term and long term adverse consequences for both mother and child. Obesity causes problems with infertility, and in early gestation it causes spontaneous pregnancy loss and congenital anomal...

  7. In-Plant Fission Product Behavior in SGTR Accident with Long-Term SBO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Han, Seok Jung; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The off-site AC power was recovered in 9 days after the accident in the NPS. Therefore safety injection by fire pump truck with fresh water or seawater is only available in the Fukushima accident. However, safety injection by fire pump truck is not always effective due to the high pressure of RPV inside or leakages of alternative water injection flow paths. In the SBO situations in pressurized water reactor plant (PWR), turbine driven auxiliary feedwater (TD-AFW) pump can inject water to the secondary side of steam generator. However, turbine inlet steam flow control valve cannot work properly when loss of vital DC power occurs. Vital DC power is designed to be maintained during 4 or 8 hours in the SBO conditions. In this paper motor-driven and turbine driven AFW pumps are all assumed to be not working at time 0 sec as a worst case assumption. Iodine pool-scrubbing can occur in the secondary side of the faulted steam generator. However, iodine pool-scrubbing in the secondary side of the faulted steam generator is assumed not to be working, due to the assumption of the loss of DC battery for turbine inlet flow control valve. Iodine pool-scrubbing is one of the long-term research issues in safety assessment of nuclear power plant severe accident. PHEBUS FPT series and THAI experiment projects are typical projects on the resolving source term issues in severe accident of nuclear power plants. However, iodine retention by pool scrubbing is still a debating issue. In such containment bypass sequences, fission products can be released out to environment directly from RCS without retention or deposition in containment structures. SGTR is one of the hazardous accident scenarios in the typical PSA, because SGTR induces a large release amount of source term to environment directly. A key operation strategy was the isolation of the broken reactor coolant system loop from the intact loop. Typical core degradation in SGTR scenarios occurs with multiple failures of the isolation

  8. Long-Term Prediction of Large Earthquakes: When Does Quasi-Periodic Behavior Occur?

    Science.gov (United States)

    Sykes, L. R.

    2003-12-01

    every great earthquake. The 2002 Working Group on large earthquakes in the San Francisco Bay region followed Ellsworth et al. (1999) in adopting much larger values of CV for several critical fault segments and underestimating their likelihood of rupture in the next 30 years. The Working Group also gives considerable weight to a Poisson model, which is in conflict with both renewal processes involving slow stress accumulation and with values of CV near 0.2. The failure of the Parkfield prediction has greatly influenced views in the U.S. about long-term forecasts. The model of the repeated breaking of a single asperity is incorrect since past Parkfield shocks of about magnitude 6 likely did not rupture the same part of the San Andreas fault.

  9. The mechanisms underlying long-term potentiation of C-fiber evoked field potentials in spinal dorsal horn

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-Guo

    2008-01-01

    Long-term potentiation (LTP) of C-fiber evoked feld potentials in spinal dorsal horn is first reported in 1995. Since then, the mechanisms underlying the long-lasting enhancement in synaptic transmission between primary afferent C-fibers and neurons in spinal dorsal horn have been investigated by different laboratories. In this article, the related data were summarized and discussed.

  10. Impact of Prosthesis-Patient Mismatch on Long-term Functional Capacity After Mechanical Aortic Valve Replacement

    NARCIS (Netherlands)

    Petit-Eisenmann, H.; Epailly, E.; Velten, M.; Radojevic, J.; Eisenmann, B.; Kremer, H.; Kindo, M.

    2016-01-01

    BACKGROUND: The impact of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) for aortic stenosis on exercise capacity remains controversial. The aim of this study was to analyze the long-term impact of PPM after mechanical AVR on maximal oxygen uptake (VO2max). METHODS: The study

  11. Perinatal acquisition of drug-resistant HIV-1 infection: mechanisms and long-term outcome

    Directory of Open Access Journals (Sweden)

    Dollfus Catherine

    2009-09-01

    Full Text Available Abstract Background Primary-HIV-1-infection in newborns that occurs under antiretroviral prophylaxis that is a high risk of drug-resistance acquisition. We examine the frequency and the mechanisms of resistance acquisition at the time of infection in newborns. Patients and Methods We studied HIV-1-infected infants born between 01 January 1997 and 31 December 2004 and enrolled in the ANRS-EPF cohort. HIV-1-RNA and HIV-1-DNA samples obtained perinatally from the newborn and mother were subjected to population-based and clonal analyses of drug resistance. If positive, serial samples were obtained from the child for resistance testing. Results Ninety-two HIV-1-infected infants were born during the study period. Samples were obtained from 32 mother-child pairs and from another 28 newborns. Drug resistance was detected in 12 newborns (20%: drug resistance to nucleoside reverse transcriptase inhibitors was seen in 10 cases, non-nucleoside reverse transcriptase inhibitors in two cases, and protease inhibitors in one case. For 9 children, the detection of the same resistance mutations in mothers' samples (6 among 10 available and in newborn lymphocytes (6/8 suggests that the newborn was initially infected by a drug-resistant strain. Resistance variants were either transmitted from mother-to-child or selected during subsequent temporal exposure under suboptimal perinatal prophylaxis. Follow-up studies of the infants showed that the resistance pattern remained stable over time, regardless of antiretroviral therapy, suggesting the early cellular archiving of resistant viruses. The absence of resistance in the mother of the other three children (3/10 and neonatal lymphocytes (2/8 suggests that the newborns were infected by a wild-type strain without long-term persistence of resistance when suboptimal prophylaxis was stopped. Conclusion This study confirms the importance of early resistance genotyping of HIV-1-infected newborns. In most cases (75%, drug

  12. Computer-assisted direct observation of behavioral agitation, engagement, and affect in long-term care residents.

    Science.gov (United States)

    Casey, Anne-Nicole; Low, Lee-Fay; Goodenough, Belinda; Fletcher, Jennifer; Brodaty, Henry

    2014-07-01

    The objectives of the current research were (1) to test and evaluate the investigator-designed Behavior, Engagement, and Affect Measure (BEAM) touchpad direct observational data collection tool, and (2) to implement this tool to investigate residents' patterns of behavioral agitation, engagement, affect, behaviors associated with positive mood, general time-activity use, and social interactions within long-term care. Raters collected cross-sectional observational data and conducted semistructured interviews with participants of the Sydney Multisite Intervention of LaughterBosses and ElderClowns (SMILE) Study. Researchers tested the BEAM's reliability and validity and evaluated the instrument's discriminate validity for sampling resident behaviors. Data were collected in 36 long-term care homes. The sample included low-care hostels, high-care nursing homes, and residential facilities offering aging-in-place. Participants were 406 residents aged 52 to 105 years, with and without dementia. Researchers collected direct observational data using the BEAM and operationalized behavioral domains based largely on concepts from Kitwood's model of person-centered care. Care staff reported on resident behavior using standardized measures of agitation, depression, quality of life, and social engagement. The BEAM showed moderate-to-substantial interrater reliability and slight-to-moderate correlations with staff-report data gathered through standardized questionnaire measures. Observations showed that residents spent the greatest amount of time stationary and expressing little emotion, although actively engaged with their environment. Residents were observed to be coping adequately and experiencing a positive social and/or positive care interaction in approximately half of observations; however, close to a third of ratings identified "ill-being." Residents showed more positive behavior, appeared happier and less anxious, and exhibited higher "well-being" during structured

  13. Echocardiographic Assessment of Ischaemic Mitral Regurgitation, Mechanism, Severity, Impact on Treatment Strategy and Long Term Outcome

    Science.gov (United States)

    Naser, Nabil; Dzubur, Alen; Kusljugic, Zumreta; Kovacevic, Katarina; Kulic, Mehmed; Sokolovic, Sekib; Terzic, Ibrahim; Haxihibeqiri-Karabdic, Ilirijana; Hondo, Zorica; Brdzanovic, Snjezana; Miseljic, Sanja

    2016-01-01

    Introduction: The commonest mitral regurgitation etiologies are degenerative (60%), rheumatic post-inflammatory, 12%) and functional (25%). Due to the large number of patients with acute MI, the incidence of ischaemic MR is also high. Ischaemic mitral regurgitation is a complex multifactorial disease that involves left ventricular geometry, the mitral annulus, and the valvular/subvalvular apparatus. Ischaemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction. Research Objectives: The objective of this study is to determine the role of echocardiography in detecting and assessment of mitral regurgitation mechanism, severity, impact on treatment strategy and long term outcome in patients with myocardial infarction during the follow up period of 5 years. Also one of objectives to determine if the absence or presence of ischaemic MR is associated with increased morbidity and mortality in patients with myocardial infarction. Patients and methods: The study covered 138 adult patients. All patients were subjected to echocardiography evaluation after acute myocardial infarction during the period of follow up for 5 years. The patients were examined on an ultrasound machine Philips iE 33 xMatrix, Philips HD 11 XE, and GE Vivid 7 equipped with all cardiologic probes for adults and multi-plan TEE probes. We evaluated mechanisms and severity of mitral regurgitation which includes the regurgitant volume (RV), effective regurgitant orifice area (EROA), the regurgitant fraction (RF), Jet/LA area, also we measured the of vena contracta width (VC width cm) for assessment of IMR severity, papillary muscles anatomy and displacement, LV systolic function ± dilation, LV regional wall motion abnormality WMA, LV WMI, Left ventricle LV remodeling, impact on treatment strategy and long term mortality. Results: We analyzed and follow up 138 patients with previous (>16 days) Q-wave myocardial infarction by ECG who underwent TTE and TEE

  14. Sevoflurane exposure during the neonatal period induces long-term memory impairment but not autism-like behaviors.

    Science.gov (United States)

    Chung, Woosuk; Park, Saegeun; Hong, Jiso; Park, Sangil; Lee, Soomin; Heo, Junyoung; Kim, Daesoo; Ko, Youngkwon

    2015-10-01

    To examine whether neonatal exposure to sevoflurane induces autism-like behaviors in mice. There are continuing reports regarding the potential negative effects of anesthesia on the developing brain. Recently, several studies suggest that neurotoxicity caused by anesthesia may lead to neurodevelopmental impairments. However, unlike reports focusing on learning and memory, there are only a few animal studies focusing on neurodevelopmental disorders after general anesthesia. Therefore, we have focused on autism, a representative neurodevelopmental disorder. Neonatal mice (P6-7) were exposed to a titrated dose of sevoflurane for 6 h. Apoptosis was evaluated by assessing the expression level of cleaved (activated) caspase-3. Autism-like behaviors, general activity, anxiety level, and long-term memory were evaluated with multiple behavioral assays. Western blotting confirmed that neonatal exposure to sevoflurane increased the expression level of activated caspase-3, indicative of apoptosis. Mice exposed to sevoflurane also showed impaired long-term memory in fear tests. However, sevoflurane-exposed mice did not exhibit autism-like features in all of the following assays: social interaction (three-chamber test, caged social interaction), social communication (ultrasonic vocalization test), or repetitive behavior (self-grooming test, digging). There were also no differences in general activity (open field test, home cage activity) and anxiety (open field test, light-dark box) after sevoflurane exposure. Our results confirm previous studies that neonatal sevoflurane exposure causes neurodegeneration and long-term memory impairment in mice. However, sevoflurane did not induce autism-like features. Our study suggests that mice are more vulnerable to long-term memory deficits than autism-like behaviors after exposure to sevoflurane. © 2015 John Wiley & Sons Ltd.

  15. The Study on the Mechanical Properties of Optical Fiber With Long-Term Time Aging

    Institute of Scientific and Technical Information of China (English)

    Sung Koog Oh; Young Seok Kim; Jae Ho Lee

    2003-01-01

    The fiber properties depending on the coating thickness and long-term time aging were investigated. The coating strip forces of optical fiber were strongly increased with secondary coating thickness. But it did not change with time aging up to 90 days. The tensile strength and stress corrosion parameters of coated fiber were increased with time aging also but the increasing rate was quite different depending on the coating thickness

  16. Long-term effects of environmental endocrine disruptors on reproductive physiology and behavior

    Directory of Open Access Journals (Sweden)

    Heather B Patisaul

    2009-06-01

    Full Text Available It is well established that, over the course of development, hormones shape the vertebrate brain such that sex specific physiology and behaviors emerge. Much of this occurs in discrete developmental windows that span gestation through the prenatal period, although it is now becoming clear that at least some of this process continues through puberty. Perturbation of this developmental progression can permanently alter the capacity for reproductive success. Wildlife studies have revealed that exposure to endocrine disrupting compounds (EDCs, either naturally occurring or man made, can profoundly alter reproductive physiology and ultimately impact entire populations. Laboratory studies in rodents and other species have elucidated some of the mechanisms by which this occurs and strongly indicate that humans are also vulnerable to disruption. Use of hormonally active compounds in human medicine has also unfortunately revealed that the developing fetus can be exposed to and affected by endocrine disruptors, and that it might take decades for adverse effects to manifest. Research within the field of environmental endocrine disruption has also contributed to the general understanding of how early life experiences can alter reproductive physiology and behavior through non-genomic, epigenetic mechanisms such as DNA methylation and histone acetylation. These types of effects have the potential to impact future generations if the germ line is affected. This review provides an overview of how exposure to EDCs, particularly those that interfere with estrogen action, impacts reproductive physiology and behaviors in vertebrates.

  17. Mode Analysis for Long-Term Behavior in a Resonant Earth-Moon Trajectory

    Science.gov (United States)

    Short, Cody; Howell, Kathleen; Haapala, Amanda; Dichmann, Donald

    2016-11-01

    Trajectory design in chaotic regimes allows for the exploitation of system dynamics to achieve certain behaviors. For example, for the Transiting Exoplanet Survey Satellite (TESS) mission, the selected science orbit represents a stable option well-suited to meet the mission objectives. Extended analysis of particular solutions nearby in the phase space reveals transitions into desirable terminal modes induced by natural dynamics. This investigation explores the trajectory behavior and borrows from flow-based analysis strategies to characterize modes of such a motion. Perturbed initial states from a TESS-like orbit are evolved to supply motion suitable for contingency analysis. Through the associated analysis, mechanisms are identified that drive the spacecraft into particular modes and supply conditions necessary for such transitions.

  18. Long-term reproductive and behavioral toxicity of anthracene to fish in the presence of solar ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, A.T. [Sandoz Agro, Inc., Des Plaines, IL (United States); Oris, J.T. [Miami Univ. Oxford, OH (United States)

    1994-12-31

    The long-term, low-level effects of anthracene in the presence of solar ultraviolet radiation (SUVR) were examined in the fathead minnow (Pimephales promelas). Adult fish exposed to anthracene exhibited reduced egg laying capacity, with altered oocyte maturation as a potential mechanism of action. Eggs and larvae maternally exposed to anthracene exhibited reduced hatching success and severe developmental abnormalities when incubated under SUVR. The combination of reduced egg output and developmental effects resulted in an inhibition in reproductive capacity in the range of 70--100%. Maternal transfer of anthracene to eggs was efficient; the BCF was 717 for maternally exposed eggs. However, anthracene deputation from eggs after oviposition with only maternal PAH exposure was rapid; anthracene half-life from eggs equaled 1.3 days. Exposure to anthracene under SUVR altered locomotor activity patterns in fathead minnows by inducing hyperactivity or hypoactivity during the light or dark phases of the photoperiod, respectively. Altered activity patterns indicated potential effects of anthracene on the nervous system and/or pineal gland. These alterations disrupted normal activity patterns and reproductive behaviors, and thus have major implications on a fish`s ability to survive and reproduce. Anthracene, a model phototoxic PAH, has many potential sites of toxic action, and any organism exposed to such contaminants will be an considerable SUVR-enhanced risk in the environment.

  19. Acute and long-term effects of intracerebroventricular administration of α-ketoisocaproic acid on oxidative stress parameters and cognitive and noncognitive behaviors.

    Science.gov (United States)

    Taschetto, Luciane; Scaini, Giselli; Zapelini, Hugo G; Ramos, Ândrea C; Strapazzon, Giulia; Andrade, Vanessa M; Réus, Gislaine Z; Michels, Monique; Dal-Pizzol, Felipe; Quevedo, João; Schuck, Patrícia F; Ferreira, Gustavo C; Streck, Emilio L

    2017-05-27

    Maple Syrup Urine Disease (MSUD) is biochemically characterized by elevated levels of leucine, isoleucine and valine, as well as their corresponding transaminated branched-chain α-keto acids in tissue and biological fluids. Neurological symptoms and cerebral abnormalities, whose mechanisms are still unknown, are typical of this metabolic disorder. In the present study, we evaluated the early effects (1 h after injection) and long-term effects (15 days after injection) of a single intracerebroventricular administration of α-ketoisocaproic acid (KIC) on oxidative stress parameters and cognitive and noncognitive behaviors. Our results showed that KIC induced early and long-term effects; we found an increase in TBARS levels, protein carbonyl content and DNA damage in the hippocampus, striatum and cerebral cortex both one hour and 15 days after KIC administration. Moreover, SOD activity increased in the hippocampus and striatum one hour after injection, whereas after 15 days, SOD activity decreased only in the striatum. On the other hand, KIC significantly decreased CAT activity in the striatum one hour after injection, but 15 days after KIC administration, we found a decrease in CAT activity in the hippocampus and striatum. Finally, we showed that long-term cognitive deficits follow the oxidative damage; KIC induced impaired habituation memory and long-term memory impairment. From the biochemical and behavioral findings, it we presume that KIC provokes oxidative damage, and the persistence of brain oxidative stress is associated with long-term memory impairment and prepulse inhibition.

  20. Long-Term Evolution of Email Networks: Statistical Regularities, Predictability and Stability of Social Behaviors.

    Science.gov (United States)

    Godoy-Lorite, Antonia; Guimerà, Roger; Sales-Pardo, Marta

    2016-01-01

    In social networks, individuals constantly drop ties and replace them by new ones in a highly unpredictable fashion. This highly dynamical nature of social ties has important implications for processes such as the spread of information or of epidemics. Several studies have demonstrated the influence of a number of factors on the intricate microscopic process of tie replacement, but the macroscopic long-term effects of such changes remain largely unexplored. Here we investigate whether, despite the inherent randomness at the microscopic level, there are macroscopic statistical regularities in the long-term evolution of social networks. In particular, we analyze the email network of a large organization with over 1,000 individuals throughout four consecutive years. We find that, although the evolution of individual ties is highly unpredictable, the macro-evolution of social communication networks follows well-defined statistical patterns, characterized by exponentially decaying log-variations of the weight of social ties and of individuals' social strength. At the same time, we find that individuals have social signatures and communication strategies that are remarkably stable over the scale of several years.

  1. Long-term lumen depreciation behavior and failure modes of multi-die array LEDs

    Science.gov (United States)

    Jayawardena, Asiri; Marcus, Daniel; Prugue, Ximena; Narendran, Nadarajah

    2013-09-01

    One of the main advantages of multi-die array light-emitting diodes (LEDs) is their high flux density. However, a challenge for using such a product in lighting fixture applications is the heat density and the need for thermal management to keep the junction temperatures of all the dies low for long-term reliable performance. Ten multi-die LED array samples for each product from four different manufacturers were subjected to lumen maintenance testing (as described in IES-LM-80-08), and their resulting lumen depreciation and failure modes were studied. The products were tested at the maximum case (or pin) temperature reported by the respective manufacturer by appropriately powering the LEDs. In addition, three samples for each product from two different manufacturers were subjected to rapid thermal cycling, and the resulting lumen depreciation and failure modes were studied. The results showed that the exponential lumen decay model using long-term lumen maintenance data as recommended in IES TM-21 does not fit for all package types. The failure of a string of dies and single die failure in a string were observed in some of the packages.

  2. Structural evolution and the capacity fade mechanism upon long-term cycling in Li-rich cathode material.

    Science.gov (United States)

    Song, Bohang; Liu, Zongwen; Lai, Man On; Lu, Li

    2012-10-01

    High capacity Li-rich layered cathode Li(Li(0.2)Mn(0.54)Ni(0.13)Co(0.13))O(2) and doped one are investigated to understand mechanisms of capacity fade as well as voltage decrease upon long-term cycling. Detailed electrochemical analysis reveals a phase-separation-like behavior with increase in the cycle number, which is responsible for gradual reduction in discharge voltage. X-ray photoelectron spectroscopy (XPS), transmission electron microscope coupled with energy dispersive X-ray spectroscopy (TEM-EDS) and inductively coupled plasma emission spectrometry (ICP) analysis results show increase in valence of transition metals on the surface of powder at a fully discharged state in addition to surface dissolution of Ni, leading to rapid capacity loss. High resolution transmission electron microscopy (HR-TEM) shows a phase transformation from original layered structure into spinel-like nano-domains in local structure. Though such an unexpected structural change is unfavorable because of lower output voltage, it is observed to be beneficial for high-rate performance.

  3. Long-term faulting behavior of eastern Altyn Tagh fault, north Tibetan Plateau

    Science.gov (United States)

    Xu, X.; Klinger, Y.; Tapponnier, P.; Chen, G.; Li, K.; Tan, X. B.

    2015-12-01

    The Altyn Tagh Fault (ATF) bounds the Tibetan Plateau to the north and is the longest continental active strike-slip fault at lithospheric scale within the India-Eurasia collision zone (Wittlinger et al., 1998). Together with other mega strike-slip faults, e.g., the Kunlun, Haiyuan, Xianshuihe and Jiali faults, it plays an important role in both the two end member models, eastward block-like motion and distributed deformation or channel flow, to accommodate the India-Eurasia convergence. However, how much amount of northward motion, from convergence between Indian and Eurasian plates to the south, has been transferred by localized slip on the ATF into eastward motion of the Plateau relative to the Tarim basin is still unclear. Its main reason may be originated from disagreements over quite scattered Quaternary left-slip rates from 2 mm/yr up to 30 mm/yr and also difference in slip rate over time scales of 10 yr from GPS and InSAR to 10 kyr from Quaternary offset-landforms. However, accurate Quaternary long-term average slip rate is the first step for quantitatively evaluating the role of the ATF in transferring northward convergence of the India-Eurasia collision into eastward escape and then for understanding the kinematic model of the Tibetan Plateau. Here we present a synthetic approach to well constrain long-term left-slip rate by identifying paleo-earthquake sequence as precise chronologic bounds for the associated measured cumulative displacements at two sites on the Aksay segment of the ATF. This result is very important not only to establish surface-rupturing earthquake recurrence model to reduce its potential earthquake hazards along the ATF, but also to solve the long-standing dispute over the high or low Quaternary slip rates by using diferent terrace models and geodetic strain rate. Analysis of the paleo-earthquakes from trenches and recent cumulative offsets reveals a Holocene surface-rupturing faulting process, which well constrains the long-term slip

  4. Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.

    Science.gov (United States)

    Santini, Emanuela; Huynh, Thu N; Klann, Eric

    2014-01-01

    The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. © 2014 Elsevier Inc. All rights reserved.

  5. Effects of Aging-Time Reference on the Long Term Behavior of the IM7/K3B Composite

    Science.gov (United States)

    Veazie, David R.; Gates, Thomas S.

    1998-01-01

    An analytical study was undertaken to investigate the effects of the time-based shift reference on the long term behavior of the graphite reinforced thermoplastic polyimide composite IM7/K3B at elevated temperature. Creep compliance and the effects of physical aging on the time dependent response was measured for uniaxial loading at several isothermal conditions below the glass transition temperature (T(sub g). Two matrix dominated loading modes, shear and transverse, were investigated in tension and compression. The momentary sequenced creep/aging curves were collapsed through a horizontal (time) shift using the shortest, middle and longest aging time curve as the reference curve. Linear viscoelasticity was used to characterize the creep/recovery behavior and superposition techniques were used to establish the physical aging related material constants. The use of effective time expressions in a laminated plate model allowed for the prediction of long term creep compliance. The effect of using different reference curves with time/aging-time superposition was most sensitive to the physical aging shift rate at lower test temperatures. Depending on the loading mode, the reference curve used can result in a more accurate long term prediction, especially at lower test temperatures.

  6. Long-term desorption behavior of uranium and neptunium in heterogeneous volcanic tuff materials /

    Energy Technology Data Exchange (ETDEWEB)

    Dean, Cynthia A.

    2010-05-01

    Uranium and neptunium desorption were studied in long-term laboratory experiments using four well-characterized volcanic tuff cores collected from southeast of Yucca Mountain, Nevada. The objectives of the experiments were to 1. Demonstrate a methodology aimed at characterizing distributions of sorption parameters (attributes of multiple sorption sites) that can be applied to moderately-sorbing species in heterogeneous systems to provide more realistic reactive transport parameters and a more realistic approach to modeling transport in heterogeneous systems. 2. Focus on uranium and neptunium because of their high solubility, relatively weak sorption, and high contributions to predicted dose in Yucca Mountain performance assessments. Also, uranium is a contaminant of concern at many DOE legacy sites and uranium mining sites.

  7. Grain Growth and Precipitation Behavior of Iridium Alloy DOP-26 During Long Term Aging

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Dean T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Muralidharan, Govindarajan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fox, Ethan E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cox, Victoria A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Geer, Tom [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-01

    The influence of long term aging on grain growth and precipitate sizes and spatial distribution in iridium alloy DOP-26 was studied. Samples of DOP-26 were fabricated using the new process, recrystallized for 1 hour (h) at 1375 C, then aged at either 1300, 1400, or 1500 C for times ranging from 50 to 10,000 h. Grain size measurements (vertical and horizontal mean linear intercept and horizontal and vertical projection) and analyses of iridium-thorium precipitates (size and spacing) were made on the longitudinal, transverse, and rolling surfaces of the as-recrystallized and aged specimens from which the two-dimensional spatial distribution and mean sizes of the precipitates were obtained. The results obtained from this study are intended to provide input to grain growth models.

  8. Short- and long-term behavioral analysis of social interaction, ultrasonic vocalizations and social motivation in a chronic phencyclidine model.

    Science.gov (United States)

    Peters, Suzanne M; Tuffnell, Joe A; Pinter, Ilona J; van der Harst, Johanneke E; Spruijt, Berry M

    2017-05-15

    Phencyclidine (PCP) has been suggested to induce symptoms of schizophrenia. However, animal models using PCP administration have produced ambiguous results thus far. It seems that acute effects are similar to symptoms of schizophrenia, however, it is not clear if PCP can induce permanent behavioral changes that reflect schizophrenic-like symptoms. Therefore, we assessed the ability of chronic PCP administration (3mg/kg, 14 days) to induce short or long lasting behavioral changes in rats. Social behavior, including ultrasonic vocalizations and motivation for social contact were investigated at different time points, up to 29-36 days, after cessation of PCP treatment. During a social separation test, performed at 5 and 36 days, PCP treated rats spent less time near the divider that separates them from their familiar cage mate compared with saline (SAL) treated rats. Further, at short term, PCP was able to induce a decrease in social behavior. In contrast, at long-term, PCP treated animals spent more time in contact when exposed to an unfamiliar partner as compared to SAL treated rats. But, this difference was not observed when exposed to a familiar partner. We did not find any difference in ultrasonic vocalizations at all time points. The results of our study indicate that PCP is unable to induce overt long term deficits in social interaction behavior. Rather, it seems that PCP diminishes motivation for social contact. The long-term consequences of chronic PCP administration on social behavior in rodent models remain complex, and future studies addressing this are still needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Multiple dynamo modes as a mechanism for long-term solar activity variations

    CERN Document Server

    Käpylä, Maarit J; Olspert, Nigul; Brandenburg, Axel; Warnecke, Jörn; Karak, Bidya B; Pelt, Jaan

    2015-01-01

    Solar magnetic activity shows both smooth secular changes, such as the Grand Modern Maximum, and quite abrupt drops that are denoted as Grand Minima. Direct numerical simulations (DNS) of convection drivendynamos offer one way of examining the mechanisms behind these events. In this work, we analyze a solution of a solar-like DNS that has been evolved for roughly 80 magnetic cycles of 5.4 years, during which epochs of irregular behavior are detected. The emphasis of our analysis is to find physical causes for such behavior. The DNS employed is a semi-global (wedge) magnetoconvection model. For data analysis we use Ensemble Empirical Mode Decomposition (EEMD) and phase dispersion (D^2) methods. A special property of the DNS is the existence of multiple dynamo modes at different depths and latitudes. The dominant mode is solar-like. This mode is accompanied by a higher frequency mode near the surface and a low-frequency mode in the bottom of the convection zone. The overall behavior of the dynamo solution is ve...

  10. Stress and glucocorticoid receptor-dependent mechanisms in long-term memory: from adaptive responses to psychopathologies.

    Science.gov (United States)

    Finsterwald, Charles; Alberini, Cristina M

    2014-07-01

    A proper response against stressors is critical for survival. In mammals, the stress response is primarily mediated by secretion of glucocorticoids via the hypothalamic-pituitary-adrenocortical (HPA) axis and release of catecholamines through adrenergic neurotransmission. Activation of these pathways results in a quick physical response to the stress and, in adaptive conditions, mediates long-term changes in the brain that lead to the formation of long-term memories of the experience. These long-term memories are an essential adaptive mechanism that allows an animal to effectively face similar demands again. Indeed, a moderate stress level has a strong positive effect on memory and cognition, as a single arousing or moderately stressful event can be remembered for up to a lifetime. Conversely, exposure to extreme, traumatic, or chronic stress can have the opposite effect and cause memory loss, cognitive impairments, and stress-related psychopathologies such as anxiety disorders, depression and post-traumatic stress disorder (PTSD). While more effort has been devoted to the understanding of the negative effects of chronic stress, much less has been done thus far on the identification of the mechanisms engaged in the brain when stress promotes long-term memory formation. Understanding these mechanisms will provide critical information for use in ameliorating memory processes in both normal and pathological conditions. Here, we will review the role of glucocorticoids and glucocorticoid receptors (GRs) in memory formation and modulation. Furthermore, we will discuss recent findings on the molecular cascade of events underlying the effect of GR activation in adaptive levels of stress that leads to strong, long-lasting memories. Our recent data indicate that the positive effects of GR activation on memory consolidation critically engage the brain-derived neurotrophic factor (BDNF) pathway. We propose and will discuss the hypothesis that stress promotes the formation of

  11. Stress and glucocorticoid receptor-dependent mechanisms in long-term memory: from adaptive responses to psychopathologies

    Science.gov (United States)

    Finsterwald, Charles; Alberini, Cristina M.

    2013-01-01

    A proper response against stressors is critical for survival. In mammals, the stress response is primarily mediated by secretion of glucocorticoids via the hypothalamic-pituitaryadrenocortical (HPA) axis and release of catecholamines through adrenergic neurotransmission. Activation of these pathways results in a quick physical response to the stress and, in adaptive conditions, mediates long-term changes in the brain that lead to the formation of long-term memories of the experience. These long-term memories are an essential adaptive mechanism that allows an animal to effectively face similar demands again. Indeed, a moderate stress level has a strong positive effect on memory and cognition, as a single arousing or moderately stressful event can be remembered for up to a lifetime. Conversely, exposure to extreme, traumatic, or chronic stress can have the opposite effect and cause memory loss, cognitive impairments, and stress-related psychopathologies such as anxiety disorders, depression and post-traumatic stress disorder (PTSD). While more effort has been devoted to the understanding of the effects of the negative effects of chronic stress, much less has been done thus far on the identification of the mechanisms engaged in the brain when stress promotes long-term memory formation. Understanding these mechanisms will provide critical information for use in ameliorating memory processes in both normal and pathological conditions. Here, we will review the role of glucocorticoids and glucocorticoid receptors (GRs) in memory formation and modulation. Furthermore, we will discuss recent findings on the molecular cascade of events underlying the effect of GR activation in adaptive levels of stress that leads to strong, long-lasting memories. Our recent data indicate that the positive effects of GR activation on memory consolidation critically engage the brain-derived neurotrophic factor (BDNF) pathway. We propose and will discuss the hypothesis that stress promotes the

  12. Synergistic Effects of Physical Aging and Damage on Long-Term Behavior of Polymer Matrix Composites

    Science.gov (United States)

    Brinson, L. Cate

    1999-01-01

    The research consisted of two major parts, first modeling and simulation of the combined effects of aging and damage on polymer composites and secondly an experimental phase examining composite response at elevated temperatures, again activating both aging and damage. For the simulation, a damage model for polymeric composite laminates operating at elevated temperatures was developed. Viscoelastic behavior of the material is accounted for via the correspondence principle and a variational approach is adopted to compute the temporal stresses within the laminate. Also, the effect of physical aging on ply level stress and on overall laminate behavior is included. An important feature of the model is that damage evolution predictions for viscoelastic laminates can be made. This allows us to track the mechanical response of the laminate up to large load levels though within the confines of linear viscoelastic constitutive behavior. An experimental investigation of microcracking and physical aging effects in polymer matrix composites was also pursued. The goal of the study was to assess the impact of aging on damage accumulation, in ten-ns of microcracking, and the impact of damage on aging and viscoelastic behavior. The testing was performed both at room and elevated temperatures on [+/- 45/903](sub s) and [02/903](sub s) laminates, both containing a set of 90 deg plies centrally located to facilitate investigation of microcracking. Edge replication and X-ray-radiography were utilized to quantify damage. Sequenced creep tests were performed to characterize viscoelastic and aging parameters. Results indicate that while the aging times studied have limited ]Influence on damage evolution, elevated temperature and viscoelastic effects have a profound effect on the damage mode seen. Some results are counterintuitive, including the lower strain to failure for elevated temperature tests and the catastrophic failure mode observed for the [+/- 45/9O3](sub s), specimens. The

  13. Long-term memory: a natural mechanism for the clustering of extreme events and anomalous residual times in climate records.

    Science.gov (United States)

    Bunde, Armin; Eichner, Jan F; Kantelhardt, Jan W; Havlin, Shlomo

    2005-02-04

    We study the statistics of the return intervals between extreme events above a certain threshold in long-term persistent records. We find that the long-term memory leads (i) to a stretched exponential distribution of the return intervals, (ii) to a pronounced clustering of extreme events, and (iii) to an anomalous behavior of the mean residual time to the next event that depends on the history and increases with the elapsed time in a counterintuitive way. We present an analytical scaling approach and demonstrate that all these features can be seen in long climate records. The phenomena should also occur in heartbeat records, Internet traffic, and stock market volatility and have to be taken into account for an efficient risk evaluation.

  14. The Long-Term Effective Mechanism of Rural Poverty Alleviation in China from the Perspective of Ecological Management

    OpenAIRE

    Liang, Jun-Si

    2010-01-01

    Based on the ecological environmental situation of poverty-stricken areas in China and the domestic and foreign research results, the long-term effective mechanism of sustainable poverty alleviation in China is established(the ideological premise is ecological culture, the material base is ecological economy and the basic guarantee is ecological system ) from the perspective of ecological management. To be specific, ecological culture, the ideological premise of rural sustainable poverty alle...

  15. Stiffening hydrogels to probe short- and long-term cellular responses to dynamic mechanics.

    Science.gov (United States)

    Guvendiren, Murat; Burdick, Jason A

    2012-04-24

    Biological processes are dynamic in nature, and growing evidence suggests that matrix stiffening is particularly decisive during development, wound healing and disease; yet, nearly all in vitro models are static. Here we introduce a step-wise approach, addition then light-mediated crosslinking, to fabricate hydrogels that stiffen (for example, ~3-30 kPa) in the presence of cells, and investigated the short-term (minutes-to-hours) and long-term (days-to-weeks) cell response to dynamic stiffening. When substrates are stiffened, adhered human mesenchymal stem cells increase their area from ~500 to 3,000 μm(2) and exhibit greater traction from ~1 to 10 kPa over a timescale of hours. For longer cultures up to 14 days, human mesenchymal stem cells selectively differentiate based on the period of culture, before or after stiffening, such that adipogenic differentiation is favoured for later stiffening, whereas osteogenic differentiation is favoured for earlier stiffening.

  16. Short and long term neuro-behavioral alterations in type 1diabetes mellitus pediatric population

    Institute of Scientific and Technical Information of China (English)

    Edna Litmanovitch; Ronny Geva; Marianna Rachmiel

    2015-01-01

    Type 1 diabetes mellitus (T1DM) is one of the mostprevalent chronic conditions affecting individualsunder the age of 18 years, with increasing incidenceworldwide, especially among very young age groups,younger than 5. There is still no cure for the disease,and therapeutic goals and guidelines are a challenge.Currently, despite T1DM intensive management andtechnological interventions in therapy, the majorityof pediatric patients do not achieve glycemic controlgoals. This leads to a potential prognosis of longterm diabetic complications, nephrological, cardiac,ophthalmological and neurological. Unfortunately, theneurological manifestations, including neurocognitiveand behavioral complications, may present soon afterdisease onset, during childhood and adolescence.These manifestations may be prominent, but at timessubtle, thus they are often not reported by patients orphysicians as related to the diabetes. Furthermore, themetabolic mechanism for such manifestations has beeninconsistent and difficult to interpret in practical clinicalcare, as reported in several reviews on the topic ofbrain and T1DM. However, new technological methodsfor brain assessment, as well as the introduction ofcontinuous glucose monitoring, provide new insightsand information regarding brain related manifestationsand glycemic variability and control parameters, whichmay impact the clinical care of children and youth withT1DM. This paper provides a comprehensive reviewof the most recently reported behavioral, cognitivedomains, sleep related, electrophysiological, andstructural alterations in children and adolescences froma novel point of view. The review focuses on reportedimpairments based on duration of T1DM, its timeline,and modifiable disease related risk parameters. Thesefindings are not without controversy, and limitations ofdata are presented in addition to recommendations forfuture research direction.

  17. Modeling of long-term defect evolution in heavy-ion irradiated 3C-SiC: Mechanism for thermal annealing and influences of spatial correlation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Daxi; He, Chaohui, E-mail: ignacio.martin@imdea.org, E-mail: hechaohui@mail.xjtu.edu.cn; Zang, Hang; Zhang, Peng [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Martin-Bragado, Ignacio, E-mail: ignacio.martin@imdea.org, E-mail: hechaohui@mail.xjtu.edu.cn [IMDEA Materiales, C/ Eric Kandel, 2, Tecnogetafe, 28906 Getafe, Madrid (Spain)

    2014-11-28

    Based on the parameters from published ab-initio theoretical and experimental studies, and combining molecular dynamics and kinetic Monte Carlo simulations, a framework of multi-scale modeling is developed to investigate the long-term evolution of displacement damage induced by heavy-ion irradiation in cubic silicon carbide. The isochronal annealing after heavy ion irradiation is simulated, and the annealing behaviors of total interstitials are found consistent with previous experiments. Two annealing stages below 600 K and one stage above 900 K are identified. The mechanisms for those recovery stages are interpreted by the evolution of defects. The influence of the spatial correlation in primary damage on defect recovery has been studied and found insignificant when the damage dose is high enough, which sheds light on the applicability of approaches with mean-field approximation to the long-term evolution of damage by heavy ions in SiC.

  18. Associations Between Long-Term Gang Membership and Informal Social Control Processes, Drug Use, and Delinquent Behavior Among Mexican American Youth.

    Science.gov (United States)

    Cepeda, Alice; Saint Onge, Jarron M; Nowotny, Kathryn M; Valdez, Avelardo

    2016-10-01

    Research has found that among juveniles weak ties to informal social control entities such as parents, school, and conventional peers increase the probability of the initiation and continuation of deviant behaviors such as drug use and crime. Given the weak ties of formal social control mechanisms in highly disadvantaged communities, informal social control mechanisms are often an important deterrent that reduce or moderate engagement in deviant behaviors among serious and persistent offenders. This analysis examines the association between long-term gang membership and adolescent informal social control processes, drug use, and delinquency. This research is based on data from a study of 160 Mexican American male gang members between the ages of 16 and 20. Findings suggest that among gang members in this context, commonly studied informal control mechanisms such as the family and schools do not function to deter long-term gang membership that is associated with serious criminal and violent behavior and drug use. The implications for future research on desistance or continuation of antisocial behavior across the life course are discussed.

  19. Rapid and Delayed Effects of Pulsed Radiofrequency on Neuropathic Pain: Electrophysiological, Molecular, and Behavioral Evidence Supporting Long-Term Depression.

    Science.gov (United States)

    Huang, Ren-Yu; Liao, Chia-Chi; Tsai, Shih-Ying; Yen, Chen-Tung; Lin, Chii-Wann; Chen, Tsung-Chi; Lin, Wei-Tso; Chang, Chi-Heng; Wen, Yeong-Ray

    2017-02-01

    Pulsed radiofrequency (PRF) has been widely employed for ameliorating clinical neuropathic pain. How PRF alters electrophysiological transmission and modulates biomolecular functions in neural tissues has yet to be clarified. We previously demonstrated that an early application of low-voltage bipolar PRF adjacent to the dorsal root ganglion (DRG) reduced acute neuropathic pain in animals. By contrast, the present study investigated how PRF alters postsynaptic sensitization to produce early and delayed effects on neuropathic pain. Our objective was to test the hypothesis that a 5-minute session of PRF could rapidly produce selective long-term depression (LTD) on C-fiber-mediated spinal sensitization and sustain the effect through the long-lasting inhibition of injury-induced ERK-MAPK activation. This may explain the prolonged analgesic effect of PRF on chronic neuropathic pain. Experiments were conducted on both normal rats and neuropathic pain rats that received spinal nerve ligation (SNL) 8 days prior. An animal laboratory in a medical center of a university in Taiwan. We first compared changes in field potentials in the L5 superficial spinal dorsal horn (SDH) that were evoked by conditioning electrical stimuli in the sciatic nerve in male adult rats before (as the baseline) and after PRF stimulation for at least 2 hours. Bipolar PRF was applied adjacent to the L5 DRG at an intensity of 5 V for 5 minutes, whereas the control rats were treated with sham applications. The electrophysiological findings were tested for any correlation with induction of spinal phospho-ERK (p-ERK) in normal and neuropathic pain rats. We then investigated the delayed effect of PRF on SNL-maintained pain behaviors for 2 weeks as well as p-ERK in SDH among the control, SNL, and PRF groups. Finally, potential injury in the DRGs after PRF stimulation was evaluated through behavioral observations and ATF-3, a neuronal stress marker. In the evoked field-potential study, the recordings mediated

  20. Long-term leaching mechanisms of ashes and slags; Combining laboratory experiments with computer simulations

    Energy Technology Data Exchange (ETDEWEB)

    Baeverman, C.

    1997-12-31

    The leaching properties of slags and ashes have been studied on four waste materials: municipal solid waste incineration, MSWI, bottom ash, wood ash, electric arc furnace slag and blast furnace slag. The aim of the study has been to investigate properties that influence the long-term leaching of these materials. The results of the laboratory experiments have been used in computer simulations using CHEMFRONTS. CHEMFRONTS is a coupled geochemical and transport computer program developed by the author within this work. The main variable influencing the leaching of metal from solid waste is the final pH of the solution. This can be controlled by several factors, but if the contact time between the water and the waste material is sufficient, the waste itself often controls the pH by buffering reactions. The buffering capacity of a material is, therefore, one of the most important factors to investigate when the long-term leaching behaviour is to be predicted. A pH titration curve has been made for each material within this work, using a pH batch experimental series. The change in pH with time has also been studied. The materials have been studied by X-ray diffraction analysis and Scanning Electron Microscopy / Energy Dispersive Spectroscopy to assess the mineralogy and morphology of the materials. The mineralogy is important for computer simulations. A number of leaching experiments have been performed. A batch flow-through method has been developed which is a serial batch experiment, in which the contact time can be controlled. This technique makes it possible to have oxygen access in all the {sup c}olumns{sup ,} to simulate partly saturated conditions. Sampling is also possible in the {sup c}olumns{sup .} The influence of particle size has been studied, and surprisingly no influence of the particle size could be noted after 24 hours of leaching. The substitution of sand in concrete with steel slag has been studied by both physical and chemical tests. The steel slag

  1. Long-Term Effects, Pathophysiological Mechanisms, and Risk Factors of Chemotherapy-Induced Peripheral Neuropathies: A Comprehensive Literature Review

    Science.gov (United States)

    Kerckhove, Nicolas; Collin, Aurore; Condé, Sakahlé; Chaleteix, Carine; Pezet, Denis; Balayssac, David

    2017-01-01

    Neurotoxic anticancer drugs, such as platinum-based anticancer drugs, taxanes, vinca alkaloids, and proteasome/angiogenesis inhibitors are responsible for chemotherapy-induced peripheral neuropathy (CIPN). The health consequences of CIPN remain worrying as it is associated with several comorbidities and affects a specific population of patients already impacted by cancer, a strong driver for declines in older adults. The purpose of this review is to present a comprehensive overview of the long-term effects of CIPN in cancer patients and survivors. Pathophysiological mechanisms and risk factors are also presented. Neurotoxic mechanisms leading to CIPNs are not yet fully understood but involve neuronopathy and/or axonopathy, mainly associated with DNA damage, oxidative stress, mitochondria toxicity, and ion channel remodeling in the neurons of the peripheral nervous system. Classical symptoms of CIPNs are peripheral neuropathy with a “stocking and glove” distribution characterized by sensory loss, paresthesia, dysesthesia and numbness, sometimes associated with neuropathic pain in the most serious cases. Several risk factors can promote CIPN as a function of the anticancer drug considered, such as cumulative dose, treatment duration, history of neuropathy, combination of therapies and genetic polymorphisms. CIPNs are frequent in cancer patients with an overall incidence of approximately 38% (possibly up to 90% of patients treated with oxaliplatin). Finally, the long-term reversibility of these CIPNs remain questionable, notably in the case of platinum-based anticancer drugs and taxanes, for which CIPN may last several years after the end of anticancer chemotherapies. These long-term effects are associated with comorbidities such as depression, insomnia, falls and decreases of health-related quality of life in cancer patients and survivors. However, it is noteworthy that these long-term effects remain poorly studied, and only limited data are available such as in

  2. Solar irradiance at the earth's surface: long-term behavior observed at the South Pole

    Directory of Open Access Journals (Sweden)

    J. E. Frederick

    2011-02-01

    Full Text Available This research examines a 17-year database of UV-A (320–400 nm and visible (400–600 nm solar irradiance obtained by a scanning spectroradiometer located at the South Pole. The goal is to define the variability in solar irradiance reaching the polar surface, with emphasis on the influence of cloudiness and on identifying systematic trends and possible links to the solar cycle. To eliminate changes associated with the varying solar elevation, the analysis focuses on data averaged over 30–35 day periods centered on each year's austral summer solstice. The long-term average effect of South Polar clouds is a small attenuation, with the mean measured irradiances being about 5–6% less than the clear-sky values, although at any specific time clouds may reduce or enhance the signal that reaches the sensor. The instantaneous fractional attenuation or enhancement is wavelength dependent, where the percent deviation from the clear-sky irradiance at 400–600 nm is typically 2.5 times that at 320–340 nm. When averaged over the period near each year's summer solstice, significant correlations appear between irradiances at all wavelengths and the solar cycle as measured by the 10.7 cm solar radio flux. An approximate 1.8 ± 1.0% decrease in ground-level irradiance occurs from solar maximum to solar minimum for the wavelength band 320–400 nm. The corresponding decrease for 400–600 nm is 2.4 ± 1.9%. The best-estimate declines appear too large to originate in the sun. If the correlations have a geophysical origin, they suggest a small variation in atmospheric attenuation with the solar cycle over the period of observation, with the greatest attenuation occurring at solar minimum.

  3. Long-term influence of divorce and single parenting on adolescent family- and work-related values, behaviors, and aspirations.

    Science.gov (United States)

    Barber, B L; Eccles, J S

    1992-01-01

    Following a summary of the relevant divorce research, this article examines possible long-term influences of both divorce and living with a single mother on the development of adolescents' values and plans. We examine how divorce affects children both directly and indirectly through its impact on the mother's resources, attitudes, and socialization goals. Particular focus is placed on those aspects of family interaction that impact on identity formation as it is linked to educational and occupational goals and to gender-role related behaviors associated with marriage, family, and job plans. Possible benefits as well as potential costs of living with a single mother are discussed.

  4. New Rapid Evaluation for Long-Term Behavior in Deep Geological Repository by Geotechnical Centrifuge—Part 2: Numerical Simulation of Model Tests in Isothermal Condition

    Science.gov (United States)

    Sawada, Masataka; Nishimoto, Soshi; Okada, Tetsuji

    2017-01-01

    In high-level radioactive waste disposal repositories, there are long-term complex thermal, hydraulic, and mechanical (T-H-M) phenomena that involve the generation of heat from the waste, the infiltration of ground water, and swelling of the bentonite buffer. The ability to model such coupled phenomena is of particular importance to the repository design and assessments of its safety. We have developed a T-H-M-coupled analysis program that evaluates the long-term behavior around the repository (called "near-field"). We have also conducted centrifugal model tests that model the long-term T-H-M-coupled behavior in the near-field. In this study, we conduct H-M-coupled numerical simulations of the centrifugal near-field model tests. We compare numerical results with each other and with results obtained from the centrifugal model tests. From the comparison, we deduce that: (1) in the numerical simulation, water infiltration in the rock mass was in agreement with the experimental observation. (2) The constant-stress boundary condition in the centrifugal model tests may cause a larger expansion of the rock mass than in the in situ condition, but the mechanical boundary condition did not affect the buffer behavior in the deposition hole. (3) The numerical simulation broadly reproduced the measured bentonite pressure and the overpack displacement, but did not reproduce the decreasing trend of the bentonite pressure after 100 equivalent years. This indicates the effect of the time-dependent characteristics of the surrounding rock mass. Further investigations are needed to determine the effect of initial heterogeneity in the deposition hole and the time-dependent behavior of the surrounding rock mass.

  5. Maternal Behavior Modifications during Pretense and Their Long-Term Effects on Toddlers' Understanding of Pretense

    Science.gov (United States)

    Nakamichi, Naoko

    2015-01-01

    Recent studies indicate the need to investigate the sources of toddlers' understanding of another person's pretense. The present study is a cultural and longitudinal extension of the work of Lillard and Witherington (2004), who claimed that mothers modify their behaviors during pretense and that the some of these behavior modifications help their…

  6. Long Term Effectiveness of Cognitive Behavioral Group Therapy for Treatment of Major Depressive Disorder: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Ceren Gokdag

    2016-03-01

    Full Text Available The aim of the study was to conduct systematic review the articles on long term effectiveness of cognitive-behavioral group therapy for treatment of major depressive disorder. Articles in English and Turkish published between the years of 2000 and 2015 (January were searched in national and international databases. The articles that did not include follow-up studies were excluded. Although the main aim of this study is to evaluate permanent effect of the cognitive behavioral group therapy, 21 articles that met the criteria were examined also in terms of some other variables such as research method, therapy characteristics and post test results. The findings of the articles revealed that cognitive-behavioral group therapy is effective for major depressive disorder and post therapy gains are maintained for a long time. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(Supplement 1: 23-38

  7. Brief embryonic strychnine exposure in zebrafish causes long-term adult behavioral impairment with indications of embryonic synaptic changes.

    Science.gov (United States)

    Roy, Nicole M; Arpie, Brianna; Lugo, Joseph; Linney, Elwood; Levin, Edward D; Cerutti, Daniel

    2012-01-01

    Zebrafish provide a powerful model of the impacts of embryonic toxicant exposure on neural development that may result in long-term behavioral dysfunction. In this study, zebrafish embryos were treated with 1.5mM strychnine for short embryonic time windows to induce transient changes in inhibitory neural signaling, and were subsequently raised in untreated water until adulthood. PCR analysis showed indications that strychnine exposure altered expression of some genes related to glycinergic, GABAergic and glutamatergic neuronal synapses during embryonic development. In adulthood, treated fish showed significant changes in swimming speed and tank diving behavior compared to controls. Taken together, these data show that a short embryonic exposure to a neurotoxicant can alter development of neural synapses and lead to changes in adult behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Mechanisms for success after long-term nutrient enrichment in a boreal forest understory.

    Directory of Open Access Journals (Sweden)

    Tess Nahanni Grainger

    Full Text Available Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest

  9. Mechanisms for success after long-term nutrient enrichment in a boreal forest understory.

    Science.gov (United States)

    Grainger, Tess Nahanni; Turkington, Roy

    2013-01-01

    Global levels of reactive nitrogen are predicted to rise in the coming decades as a result of increased deposition from the burning of fossil fuels and the large-scale conversion of nitrogen into a useable form for agriculture. Many plant communities respond strongly to increases in soil nitrogen, particularly in northern ecosystems where nitrogen levels are naturally very low. An experiment in northern Canada that was initiated in 1990 has been investigating the effects of long-term nutrient enrichment (fertilizer added annually) on a boreal forest understory community. We used this experiment to investigate why some species increase in abundance under nutrient enrichment whereas others decline. We focused on four species that differed in their responses to fertilization: Mertensia paniculata and Epilobium angustifolium increased in abundance, Achillea millefolium remained relatively constant and Festuca altaica declined. We hypothesized that the two species that were successful in the new high-nutrient, light-limited environment would be taller, have higher specific leaf area, change phenology by growing earlier in the season and be more morphologically plastic than their less successful counterparts. We compared plant height, specific leaf area, growth spurt date and allocation to leaves in plants grown in control and fertilized plots. We demonstrated that each of the two species that came to dominate fertilized plots has a different combination of traits and responses that likely gave them a competitive advantage; M. paniculata has the highest specific leaf area of the four species whereas E. angustifolium is tallest and exhibits morphological plasticity when fertilized by increasing biomass allocation to leaves. These results indicate that rather than one strategy determining success when nutrients become available, a variety of traits and responses may contribute to a species' ability to persist in a nutrient-enriched boreal forest understory.

  10. Security Behavior Observatory: Infrastructure for Long-term Monitoring of Client Machines

    Science.gov (United States)

    2014-07-14

    desired privacy settings. Another example of planned analysis consists of measuring how often users’ actu- ally make purchases derived from behavioral ...phishing attacks,’’ Communications of the ACM, vol 55, no. 1, 2012. [7] M. Jak.obsson, ’’The human factor in phishing," Privacy & Security of Consumer ...FC). Springer, 2011. [16] D. Van Broggen, S. Liu, M. Kajzer, A. Striegel, C. Crowell, and J. D’ Arey, ’’Modifying smartphone user locking behavior

  11. Effect of long-term hydrogen exposure on the mechanical properties of polymers used for pipes and tested in pressurized hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Castagnet, Sylvie, E-mail: sylvie.castagnet@ensma.fr [Institut P' (UPR CNRS 3346), CNRS-ENSMA-Universite de Poitiers, Departement de Physique et Mecanique des Materiaux, ENSMA, 1 Avenue Clement Ader, BP40109, 86961 Futuroscope cedex (France); Grandidier, Jean-Claude; Comyn, Mathieu; Benoit, Guillaume [Institut P' (UPR CNRS 3346), CNRS-ENSMA-Universite de Poitiers, Departement de Physique et Mecanique des Materiaux, ENSMA, 1 Avenue Clement Ader, BP40109, 86961 Futuroscope cedex (France)

    2012-01-15

    The influence of long-term exposure to hydrogen on the mechanical properties of polymers needs to be characterized for a reliable design of storage or transport facilities. However, mechanical tests in hydrogen atmosphere have been rarely reported. In the present study, two possible effects of hydrogen on tensile properties have been investigated in two polymers currently used for gas transport i.e. polyethylene (PE) and polyamide 11 (PA11): the mechanics-diffusion coupling and the influence of long-term exposure to hydrogen. Tensile tests in hydrogen atmosphere (30 bars) and atmospheric air at room temperature were compared, in the as-received materials as well as after aging in various conditions (pressure, temperature and duration). Results showed that the influence of hydrogen was prevalent neither on the tensile behavior nor on microstructure changes. This suggested that the design of hydrogen-dedicated parts could be based on data obtained in atmospheric air, even for long-term use. - Highlights: Black-Right-Pointing-Pointer Coupling between hydrogen diffusion and mechanics was addressed in polymers currently used for piping. Black-Right-Pointing-Pointer As-received and 13-month hydrogen-exposed polyethylene and polyamide 11 were tested. Black-Right-Pointing-Pointer Tensile tests in pressurized hydrogen and atmospheric air at ambient temperature were compared. Black-Right-Pointing-Pointer Microstructure changes during aging were tracked by standard calorimetry. Black-Right-Pointing-Pointer The influence of hydrogen was found to be prevalent neither on the tensile behavior nor on microstructure changes.

  12. Long-Term Post-Intensive Behavioral Intervention Outcomes for Five Children with Autism Spectrum Disorder

    Science.gov (United States)

    O'Connor, Anne B.; Healy, Olive

    2010-01-01

    Research clearly indicates that early intensive behavioral intervention is an effective intervention for young children with Autism Spectrum Disorder (ASD). However little is known about the longitudinal development of these children. The purpose of this study was to examine the outcomes for a number of children with ASD following intensive…

  13. [Long-term changes in adaptive behavior of rats after neonatal inflammatory pain].

    Science.gov (United States)

    Mikhailenko, V A; Butkevich, I P; Vershinina, E A; Ulanova, N A

    2015-01-01

    In this study we addressed the tonic nociceptive system functional activity in the formalin test, anxiety- and depression-like behaviors and spatial learning in adolescent male rats exposed in the neonatal development to repeated inflammatory pain peripheral stimulation. The following groups of 25-day-old rats were used after being exposed on days 7 and 8 to: 1) formalin-induced inflammatory pain with maternal separation for 60 min (FS), 2) the same inflammatory pain stimulation without maternal separation (FWS), 3) physiological saline injection with maternal separation for 1 h (SS), 4) physiological saline injection without maternal separation (SWS) and 5) no stimulation (intact rats). The data obtained indicate that pain caused in 7-8-day-old rat pups by formalin injection into the plantar pad of the hind paw manifests by adolescence (day 25 as a strengthened inflammatory response under the analogous painful stimulation in the formalin test, adaptive behavior disorder in the forced swimming test and spatial learning disability. Our findings that a short-term repeated maternal deprivation of the 7-8-day-old rat pups without inflammatory pain increases the depression-like behavior are also of particular interest. Thus, a repeated inflammatory pain during the neonatal development brings about significant changes in the adaptive behaviors studied as well as in spatial learning in adolescent rats.

  14. The Impact of Long-Term Dental Health Education on Oral Hygiene Behavior.

    Science.gov (United States)

    Houle, Bonnie A.

    1982-01-01

    A study evaluated the impact of five years' exposure to a dental health curriculum on the oral hygiene of fifth-grade students. Findings of the study indicate that a well-designed dental health curriculum based on cognitive and behavioral objectives can result in a greater accumulation of dental health knowledge. (JN)

  15. The Hidden Cost of Tourism: Detecting Long-term Effects of Tourism Using Behavioral Information

    Directory of Open Access Journals (Sweden)

    David Lusseau

    2004-06-01

    Full Text Available Increasingly, whales and dolphins are the focus of tourism activities in many coastal locations. Although these activities can affect individuals and populations of cetaceans, the biological significance and hence the cost of these impacts are as yet largely unknown. This study assessed the effects of boat interactions on the behavioral budget of two populations of bottlenose dolphins (Tersiops truncatus living in similar fjords but exposed to different levels of tourism activities. This comparison makes it possible to assess the costs of short-term avoidance strategies and the threshold at which those strategies are no longer effective. The effects of boat interactions were the same in both fjords. The resting state was the most sensitive to interactions; socializing was less sensitive. Short-term displacement was a typical response to boat exposure: dolphins were more likely to travel after an interaction with a vessel. Although the behavioral budgets of these populations were significantly altered during interactions with boats, their overall behavioral budgets were unchanged. Dolphins in Milford Sound actively avoided boat interactions, possibly to maintain their overall behavioral budget unchanged. This active avoidance led to avoidance of the area. Characteristics of dolphin-boat interactions in Milford Sound suggest that the advantages gained by short-term avoidance are lost if, on average, fewer than 68 min elapse between successive interactions with boats. If dolphin-boat interactions were more frequent than this, the dolphins switched to a longer-term response: area avoidance.

  16. Arm injury produces long-term behavioral and neural hypersensitivity in octopus.

    Science.gov (United States)

    Alupay, Jean S; Hadjisolomou, Stavros P; Crook, Robyn J

    2014-01-13

    Cephalopod molluscs are the most neurally and behaviorally complex invertebrates, with brains rivaling those of some vertebrates in size and complexity. This has fostered the opinion that cephalopods, particularly octopuses, may experience vertebrate-like pain when injured. However, it is not known whether octopuses possess nociceptors or if their somatic sensory neurons exhibit sensitization after injury. Here we show that the octopus Abdopus aculeatus expresses nocifensive behaviors including arm autotomy, and displays marked neural hyperexcitability both in injured and uninjured arms for at least 24h after injury. These findings do not demonstrate that octopuses experience pain-like states; instead they add to the minimal existing literature on how cephalopods receive, process, and integrate noxious sensory information, potentially informing and refining regulations governing use of cephalopods in scientific research.

  17. Long-Term Effects of Self-Control on Alcohol Use and Sexual Behavior among Urban Minority Young Women

    Directory of Open Access Journals (Sweden)

    Gilbert J. Botvin

    2011-12-01

    Full Text Available High risk alcohol use and sexual behaviors peak in young adulthood and often occur in the same individuals. Alcohol use has been found to impair decision-making and contribute to high risk sexual activity. However, the association between alcohol use and risky sexual behavior may also reflect enduring individual differences in risk taking, sociability, self-control, and related variables. Both behaviors can serve similar functions related to recreation, interpersonal connection, and the pursuit of excitement or pleasure. The present study examined the extent to which high risk drinking and sexual behavior clustered together in a sample of urban minority young adult women, a demographic group at elevated risk for negative outcomes related to sexual health. We tested whether psychosocial functioning measured at the beginning of high school predicted classes of risk behaviors when girls were tracked longitudinally into young adulthood. Latent class analysis indicated three distinct profiles based on high risk drinking and sexual behavior (i.e., multiple sex partners in young adulthood. The largest class (73% of the sample reported low levels of risky drinking and sexual behavior. The next largest class (19% reported high risk drinking and low risk sexual behavior, and the smallest class (8% reported high levels of both behaviors. Compared to women from other racial/ethnic groups, black women were more likely to be categorized in the high risk drinking/low risk sex class. Multinomial logistic regression indicated that self-control in adolescence had a broad and enduring protective effect on risk behaviors eight years later and was associated with a greater probability of being in the low risk drinking/low risk sex class. Findings are discussed in terms of understanding the phenotypic expressions of risk behavior as they relate to early psychosocial development and the long-term protective function of self-control in reducing high risk drinking and

  18. Long-term effects of self-control on alcohol use and sexual behavior among urban minority young women.

    Science.gov (United States)

    Griffin, Kenneth W; Scheier, Lawrence M; Acevedo, Bianca; Grenard, Jerry L; Botvin, Gilbert J

    2012-01-01

    High risk alcohol use and sexual behaviors peak in young adulthood and often occur in the same individuals. Alcohol use has been found to impair decision-making and contribute to high risk sexual activity. However, the association between alcohol use and risky sexual behavior may also reflect enduring individual differences in risk taking, sociability, self-control, and related variables. Both behaviors can serve similar functions related to recreation, interpersonal connection, and the pursuit of excitement or pleasure. The present study examined the extent to which high risk drinking and sexual behavior clustered together in a sample of urban minority young adult women, a demographic group at elevated risk for negative outcomes related to sexual health. We tested whether psychosocial functioning measured at the beginning of high school predicted classes of risk behaviors when girls were tracked longitudinally into young adulthood. Latent class analysis indicated three distinct profiles based on high risk drinking and sexual behavior (i.e., multiple sex partners) in young adulthood. The largest class (73% of the sample) reported low levels of risky drinking and sexual behavior. The next largest class (19%) reported high risk drinking and low risk sexual behavior, and the smallest class (8%) reported high levels of both behaviors. Compared to women from other racial/ethnic groups, black women were more likely to be categorized in the high risk drinking/low risk sex class. Multinomial logistic regression indicated that self-control in adolescence had a broad and enduring protective effect on risk behaviors eight years later and was associated with a greater probability of being in the low risk drinking/low risk sex class. Findings are discussed in terms of understanding the phenotypic expressions of risk behavior as they relate to early psychosocial development and the long-term protective function of self-control in reducing high risk drinking and sexual behaviors.

  19. The long-term behavior of glasses for wastes containment purposes; Le comportement a long terme des verres pour le confinement des dechets

    Energy Technology Data Exchange (ETDEWEB)

    Gin, S. [Division de l' energie nucleaire, CEA Centre de Valrho-Marcoule (France)

    2010-07-01

    In the presence of water, nuclear glasses undergo reactions that may be attributed, in part, to the nature of the chemical bonds set up within the glass structure, and - as regards other reactions - owing to the properties of the solute species. The main reactions involved include ion exchanges, these chiefly involving alkali metals, weakly bonded as these are to the glass network, silicon hydrolysis-condensation reactions, resulting in the formation of a porous hydrated layer, gradually taking on a passivating role, along with the precipitation of crystallized secondary phases. At the temperatures of interest in the disposal context (25 - 90 C degrees), such secondary phases mainly involve clay minerals. Fundamental research studies, conducted to gain an understanding of the mechanisms involved, have highlighted the existence of a strong coupling, at the mesoscopic scale, between the aforementioned chemical reactions, and solute transport, the hydrated layer having the ability to take on a passivating role, as its porosity closes. A new model named GRAAL (for Glass Reactivity with Allowance for the Alteration Layer), includes an explicit description of the four chief alteration mechanisms acting on glass: formation of the passivating layer by glass hydration, diffusion of water across that layer, dissolution of that layer over its outside surface, and precipitation of crystallized secondary phases. The equations may either be solved analytically, for simple cases, or be integrated into a geochemical code, to cater for chemistry-transport couplings, and simulate complex systems

  20. Exploring Behavioral Markers of Long-Term Physical Activity Maintenance: A Case Study of System Identification Modeling within a Behavioral Intervention

    Science.gov (United States)

    Hekler, Eric B.; Buman, Matthew P.; Poothakandiyil, Nikhil; Rivera, Daniel E.; Dzierzewski, Joseph M.; Aiken Morgan, Adrienne; McCrae, Christina S.; Roberts, Beverly L.; Marsiske, Michael; Giacobbi, Peter R., Jr.

    2013-01-01

    Efficacious interventions to promote long-term maintenance of physical activity are not well understood. Engineers have developed methods to create dynamical system models for modeling idiographic (i.e., within-person) relationships within systems. In behavioral research, dynamical systems modeling may assist in decomposing intervention effects…

  1. A Smart Wirelessly Powered Homecage for Long-Term High-Throughput Behavioral Experiments.

    Science.gov (United States)

    Lee, Byunghun; Kiani, Mehdi; Ghovanloo, Maysam

    2015-09-01

    A wirelessly powered homecage system, called the EnerCage-HC, that is equipped with multicoil wireless power transfer, closed-loop power control, optical behavioral tracking, and a graphic user interface is presented for longitudinal electrophysiology and behavioral neuroscience experiments. The EnerCage-HC system can wirelessly power a mobile unit attached to a small animal subject and also track its behavior in real-time as it is housed inside a standard homecage. The EnerCage-HC system is equipped with one central and four overlapping slanted wire-wound coils with optimal geometries to form three- and four-coil power transmission links while operating at 13.56 MHz. Utilizing multicoil links increases the power transfer efficiency (PTE) compared with conventional two-coil links and also reduces the number of power amplifiers to only one, which significantly reduces the system complexity, cost, and heat dissipation. A Microsoft Kinect installed 90 cm above the homecage localizes the animal position and orientation with 1.6-cm accuracy. Moreover, a power management ASIC, including a high efficiency active rectifier and automatic coil resonance tuning, was fabricated in a 0.35-μm 4M2P standard CMOS process for the mobile unit. The EnerCage-HC achieves a max/min PTE of 36.3%/16.1% at the nominal height of 7 cm. In vivo experiments were conducted on freely behaving rats by continuously delivering 24 mW to the mobile unit for >7 h inside a standard homecage.

  2. Alteration of Cingulate Long-Term Plasticity and Behavioral Sensitization to Inflammation by Environmental Enrichment

    Science.gov (United States)

    Shum, Fanny W. F.; Wu, Long-Jun; Zhao, Ming-Gao; Toyoda, Hiroki; Xu, Hui; Ren, Ming; Pinaud, Raphael; Ko, Shanelle W.; Lee, Yong-Seok; Kaang, Bong-Kiun; Zhuo, Min

    2007-01-01

    Exposure to an enriched environment (EE) has been shown to induce cortical plasticity. Considerable amount of research is focused on the effects of EE in the hippocampus; however, effects of EE on other brain regions and the mechanisms involved are not well known. To investigate this, we induced cortical plasticity by placing mice in an EE for one…

  3. Canonical modeling of anticipatory vaccination behavior and long term epidemic recurrence.

    Science.gov (United States)

    Flaig, Julien; Houy, Nicolas; Michel, Philippe

    2017-09-28

    Vaccination is one of humanity's main tools to fight epidemics. In most countries and for most diseases, vaccination is offered on a voluntary basis. Hence, the spread of a disease can be described as two interacting opposite dynamic systems: contagion is determined by past vaccination, while individuals decide whether to vaccinate based on beliefs regarding future disease prevalence. In this study, we show how the interplay between such anticipating behavior and the otherwise biological dynamics of a disease may lead to the emergence of recurrent patterns. We provide simulation results for (i) a Measles-like outbreak, (ii) canonical fully rational and far-sighted individuals, (iii) waning vaccine efficacy and vital dynamics, and (iv) long periods of time, i.e. long enough to observe several vaccination peaks. For comparison, we conducted a similar analysis for individuals with adaptive behavior. As an extension, we investigated the case where part of the population has an anti-vaccination stance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Mechanisms of soil organic carbon accumulation from long-term fertilization strategies in two soils: Evidence from nuclear magnetic resonance spectroscopy analysis

    Science.gov (United States)

    Long-term fertilization strategies have been proven to significantly influence soil organic carbon (SOC) accumulation, while the underlying mechanism remains unclear. Using two long-term (>20 y) field experiments of a double-cropped maize-wheat rotation on a Calcaric Fluvisol and paddy rice on a Hyd...

  5. Long-term relations among prosocial-media use, empathy, and prosocial behavior.

    Science.gov (United States)

    Prot, Sara; Gentile, Douglas A; Anderson, Craig A; Suzuki, Kanae; Swing, Edward; Lim, Kam Ming; Horiuchi, Yukiko; Jelic, Margareta; Krahé, Barbara; Liuqing, Wei; Liau, Albert K; Khoo, Angeline; Petrescu, Poesis Diana; Sakamoto, Akira; Tajima, Sachi; Toma, Roxana Andreea; Warburton, Wayne; Zhang, Xuemin; Lam, Ben Chun Pan

    2014-02-01

    Despite recent growth of research on the effects of prosocial media, processes underlying these effects are not well understood. Two studies explored theoretically relevant mediators and moderators of the effects of prosocial media on helping. Study 1 examined associations among prosocial- and violent-media use, empathy, and helping in samples from seven countries. Prosocial-media use was positively associated with helping. This effect was mediated by empathy and was similar across cultures. Study 2 explored longitudinal relations among prosocial-video-game use, violent-video-game use, empathy, and helping in a large sample of Singaporean children and adolescents measured three times across 2 years. Path analyses showed significant longitudinal effects of prosocial- and violent-video-game use on prosocial behavior through empathy. Latent-growth-curve modeling for the 2-year period revealed that change in video-game use significantly affected change in helping, and that this relationship was mediated by change in empathy.

  6. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem.

    Science.gov (United States)

    Smith, G M; Smith, K L; Kowe, R; Pérez-Sánchez, D; Thorne, M; Thiry, Y; Read, D; Molinero, J

    2014-05-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, www.bioprota.org.

  7. Long-Term Creep Behavior of the Intervertebral Disc: Comparison between Bioreactor Data and Numerical Results

    Directory of Open Access Journals (Sweden)

    APG eCastro

    2014-11-01

    Full Text Available The Loaded Disc Culture System (LDCS is an Intervertebral Disc (IVD-oriented bioreactor developed by the VU Medical Center (VUmc, Amsterdam, The Netherlands, which has the capacity of maintaining up to 12 IVDs in culture, for approximately 3 weeks after extraction. Using this system, 8 goat IVDs were provided with the essential nutrients and submitted to compression tests without losing their biomechanical and physiological properties, for 22 days. Based on previous reports (Detiger et al., 2013; Paul et al., 2013, 2012, 4 of these IVDs were kept in physiological condition (control and the other 4 were previously injected with chondroitinase ABC (CABC, in order to promote Degenerative Disc Disease (DDD. The loading profile intercalated 16h of activity loading with 8h of loading recovery to express the standard circadian variations.The displacement behavior of these 8 IVDs along the first 2 days of the experiment was numerically reproduced, using an IVD osmo-poro-hyper-viscoelastic and fiber-reinforced Finite Element (FE model. The simulations were run on a custom FE solver (Castro et al., 2014.The analysis of the experimental results allowed concluding that the effect of the CABC injection was only significant in 2 of the 4 IVDs. The 4 control IVDs showed no signs of degeneration, as expected. In what concerns to the numerical simulations, the IVD FE model was able to reproduce the generic behavior of the two groups of goat IVDs (control and injected. However, some discrepancies were still noticed on the comparison between the injected IVDs and the numerical simulations, namely on the recovery periods. This may be justified by the complexity of the pathways for DDD, associated with the multiplicity of physiological responses to each direct or indirect stimulus. Nevertheless, one could conclude that ligaments, muscles and IVD covering membranes could be added to the FE model, in order to improve its accuracy and properly describe the recovery

  8. Weaver mutant mice exhibit long-term learning deficits under several measures of instrumental behavior.

    Science.gov (United States)

    Derenne, Adam; Arsenault, Matthew L; Austin, David P; Weatherly, Jeffrey N

    2007-12-01

    Homozygous weaver mutant mice (wv/wv) exhibit symptoms that parallel Parkinson's disease, including motor deficits and the destruction of dopaminergic neurons as well as degeneration in the cerebellum and hippocampus. To develop a more complete behavioral profile of these organisms, groups of wv/wv, wv/+ mice and C57BL/6 mice were observed on a within-subjects basis under a fixed-interval schedule of reinforcement, a differential-reinforcement-of-low-rate-of-responding schedule, and a discrimination task in which a saccharin solution and tap water were concurrently available from two food cups. Under both reinforcement schedules, the wv/wv mice responded as frequently as the comparison subjects, but they responded in a manner that was inappropriate to the contingencies. Rather than respond with increasing frequency as the upcoming reinforcer became temporally proximate, wv/wv mice responded with decreasing probability as a function of the time since the previous reinforcer. Under the discrimination task, the wv/wv mice, unlike the controls, obtained saccharin over tap water at the level of chance. The findings suggest that weaver mutant mice express learning deficits similar to those found in other dopamine-deficient organisms.

  9. Estimating long-term behavior of periodically driven flows without trajectory integration

    Science.gov (United States)

    Froyland, Gary; Koltai, Péter

    2017-05-01

    Periodically driven flows are fundamental models of chaotic behavior and the study of their transport properties is an active area of research. A well-known analytic construction is the augmentation of phase space with an additional time dimension; in this augmented space, the flow becomes autonomous or time-independent. We prove several results concerning the connections between the original time-periodic representation and the time-extended representation, focusing on transport properties. In the deterministic setting, these include single-period outflows and time-asymptotic escape rates from time-parameterized families of sets. We also consider stochastic differential equations with time-periodic advection term. In this stochastic setting one has a time-periodic generator (the differential operator given by the right-hand-side of the corresponding time-periodic Fokker-Planck equation). We define in a natural way an autonomous generator corresponding to the flow on time-extended phase space. We prove relationships between these two generator representations and use these to quantify decay rates of observables and to determine time-periodic families of sets with slow escape rate. Finally, we use the generator on the time-extended phase space to create efficient numerical schemes to implement the various theoretical constructions. These ideas build on the work of Froyland et al (2013 SIAM J. Numer. Anal. 51 223-47), and no expensive time integration is required. We introduce an efficient new hybrid approach, which treats the space and time dimensions separately.

  10. Long-Term Seismicity Behavior of the Zagros Region in Iran

    Science.gov (United States)

    Madahizadeh, Rohollah; Mostafazadeh, Mehrdad; Ansari, Anooshiravan

    2016-08-01

    To achieve a comprehensive attitude about seismicity, it is necessary to consider spatial and magnitude distributions of earthquakes. Earthquake distributions in space and magnitude can be quantified by means of spatial fractal dimension D( s) and Gutenberg-Richter b value. In this paper, b value and D( s) are used to evaluate seismicity of the Zagros zone (Iran) in time interval 1964 to 2012. Seismic catalog of the Zagros zone is extracted from unified seismic catalog of the Iranian Plateau. The b value and D( s) are estimated using frequency-magnitude distribution, Kijko-Sellevoll (Bull Seism Soc Am 79(3):645-654, 1989) and correlation integral methods. Correlations between spatial variations in b value and D( s) along individual profiles across the North Zagros and the Central Zagros indicate different stress release regimes for North and Central parts of the Zagros zone. Evaluation of b value with respect to depth along the profiles indicates larger b values at shallower depths. Temporal variations in b value and D( s) are also obtained from background seismicity to evaluate seismicity behavior of the Zagros zone. Our results indicate high b values and moderate D( s) for seismicity of the North Zagros, while seismicity of the Central Zagros has low b values and high D( s) during time interval 1964-2012. Asperities of the Main Zagros Thrust are also located by investigating ratio D( s)/ b along the Main Zagros Thrust.

  11. Methylphenidate Amplifies Long-Term Plasticity in the Hippocampus via Noradrenergic Mechanisms

    Science.gov (United States)

    Dommett, Eleanor J.; Henderson, Emma L.; Westwell, Martin S.; Greenfield, Susan A.

    2008-01-01

    Methylphenidate treatment is used for Attention Deficit Hyperactivity Disorder and can improve learning and memory. Previously, improvements were considered a by-product of increased attention; however, we hypothesize that methylphenidate directly alters mechanisms underlying learning and memory, and therefore examined its effects on hippocampal…

  12. Mechanical performance of integrally bonded copper coatings for the long term disposal of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, Christopher H., E-mail: cboyle@nwmo.ca [Nuclear Waste Management Organization, 22 St. Clair Ave East, Toronto (Canada); Meguid, Shaker A. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto (Canada)

    2015-11-15

    Highlights: • A novel Used Fuel Container with an integrally bonded copper coating is proposed. • Two developed coating processes successfully produced prototype container components. • We created a validated finite element model to predict coating structural performance. • Mechanical testing confirms coating suitably for repository use. - Abstract: The preferred method for disposal of used nuclear fuel is underground emplacement in a Deep Geological Repository (DGR). Many countries have light water reactor fuels which require large Used Fuel Container or Canister (UFC) designs weighing up to 25 ton for containment. In contrast, Canada exclusively uses heavy water reactor fuel, which is substantially smaller. This has led the Nuclear Waste Management Organization (NWMO) to create a novel UFC, which uses standard pressure vessel grade steel for structural containment and a thick, integrally bonded copper coating applied to the exterior surface for corrosion protection. Currently, the coating is applied using two different methods: electrodeposition and gas dynamic cold spray. This novel copper coating needs to be fully validated to ensure adequate mechanical strength and chemical resistance for use under repository conditions. Detailed mechanical and corrosion testing programs were undertaken. Mechanical tests indicated that adhesion strengths exceeded 45 MPa and tensile properties were comparable to wrought copper. A Finite Element Model (FEM) of the copper–steel composite was created and validated using three point bend tests. This model accurately predicts the response of the composite, including large deformation and debonding failure mechanisms. Now validated, this model will be used to assess the performance of the coating on the full-scale UFC under simulated DGR loading conditions.

  13. Are long-term cancer survivors and physicians discussing health promotion and healthy behaviors?

    Science.gov (United States)

    Kenzik, Kelly M; Fouad, Mona N.; Pisu, Maria; Martin, Michelle Y.

    2017-01-01

    Purpose This study aimed to 1) describe the proportion of survivors reporting that a physician discussed strategies to improve health and 2) identify which groups are more likely to report these discussions Methods Lung and colorectal cancer (CRC) survivors (>5 years from diagnosis) (n=874) completed questionnaires, including questions on whether in the previous year a physician discussed 1) strategies to improve health, 2) exercise, and 3) diet habits. Chi-square tests and logistic regression models were used to examine whether the likelihood of these discussions varied by demographic and clinical characteristics. Results Approximately 59% reported a physician discussed strategies to improve health and exercise, 44% discussed diet, and 24% reported no discussions. Compared to their counterparts, survivors with lower education were less likely report discussing all three areas, while survivors with diabetes were more likely. Survivors ≥65 were less likely to report discussing strategies to improve health and diet. Males and CRC survivors reported discussing diet more than their female and lung cancer counterparts, respectively Conclusion The frequency of health promotion discussions varies across survivor characteristics. While discussions were more frequently reported by some groups, e.g., survivors with diabetes, or among individuals less likely to engage in healthy behaviors, e.g., males, older and less educated survivors were less likely to have these discussions. Implications for survivors Decreasing physician barriers and activating patients to discuss health promotion especially in the context of clinical care for older survivors and those with low education, is critical to promoting the overall well-being of cancer survivors. PMID:26210659

  14. Uncertainty of the Numerical Solution of a Nonlinear System's Long-term Behavior and Global Convergence of the Numerical Pattern

    Institute of Scientific and Technical Information of China (English)

    胡淑娟; 丑纪范

    2004-01-01

    The computational uncertainty principle in nonlinear ordinary differential equations makes the numerical solution of the long-term behavior of nonlinear atmospheric equations have no meaning. The main reason is that, in the error analysis theory of present-day computational mathematics, the non-linear process between truncation error and rounding erroris treated as a linear operation. In this paper, based on the operator equations of large-scale atmospheric movement, the above limitation is overcome by using the notion of cell mapping. Through studying the global asymptotic characteristics of the numerical pattern of the large-scale atmospheric equations, the definitions of the global convergence and an appropriate discrete algorithm of the numerical pattern are put forward. Three determinant theorems about the global convergence of the numerical pattern are presented, which provide the theoretical basis for constructing the globally convergent numerical pattern. Further, it is pointed out that only a globally convergent numerical pattern can improve the veracity of climatic prediction.

  15. Behavioral data of thin-film single junction amorphous silicon (a-Si) photovoltaic modules under outdoor long term exposure.

    Science.gov (United States)

    Kichou, Sofiane; Silvestre, Santiago; Nofuentes, Gustavo; Torres-Ramírez, Miguel; Chouder, Aissa; Guasch, Daniel

    2016-06-01

    Four years׳ behavioral data of thin-film single junction amorphous silicon (a-Si) photovoltaic (PV) modules installed in a relatively dry and sunny inland site with a Continental-Mediterranean climate (in the city of Jaén, Spain) are presented in this article. The shared data contributes to clarify how the Light Induced Degradation (LID) impacts the output power generated by the PV array, especially in the first days of exposure under outdoor conditions. Furthermore, a valuable methodology is provided in this data article permitting the assessment of the degradation rate and the stabilization period of the PV modules. Further discussions and interpretations concerning the data shared in this article can be found in the research paper "Characterization of degradation and evaluation of model parameters of amorphous silicon photovoltaic modules under outdoor long term exposure" (Kichou et al., 2016) [1].

  16. Reforming Management of Behavior Symptoms and Psychiatric Conditions in Long-Term Care Facilities: A Different Perspective.

    Science.gov (United States)

    Levenson, Steven A; Desai, Abhilash K

    2017-02-24

    Despite much attention including national initiatives, concerns remain about the approaches to managing behavior symptoms and psychiatric conditions across all settings, including in long-term care settings such as nursing homes and assisted living facilities. One key reason why problems persist is because most efforts to "reform" and "correct" the situation have failed to explore or address root causes and instead have promoted inadequate piecemeal "solutions." Further improvement requires jumping off the bandwagon and rethinking the entire issue, including recognizing and applying key concepts of clinical reasoning and the care delivery process to every situation. The huge negative impact of cognitive biases and rote approaches on related clinical problem solving and decision making and patient outcomes also must be addressed.

  17. Contribution of Monte-Carlo modeling for understanding long-term behavior of nuclear glasses

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Y.; Ledieu, A.; Devreux, F.; Barboux, P.; Frugier, P.; Gin, S

    2004-07-01

    Monte-Carlo methods have been developed at CEA and Ecole Polytechnique to improve our understanding of the basic mechanisms that control glass dissolution kinetics. The models, based on dissolution and recondensation rates of the atoms, can reproduce the observed alteration rates and the evolutions of the alteration layers on simplified borosilicate glasses (based on SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O) over a large range of compositions and alteration conditions. The basic models are presented, as well as their current evolutions to describe more complex glasses (introduction of Al, Zr, Ca oxides) and to take into account phenomena which may be predominant in the long run (such as diffusion in the alteration layer or secondary phase precipitation). The predictions are compared with the observations performed by techniques giving structural or textural information on the alteration layer (e.g. NMR, Small Angle X-ray Scattering). The paper concludes with proposals for further evolutions of Monte-Carlo models towards integration into a predictive modeling framework. (authors)

  18. Long-term behavior of granular chains held between walls is really equilibrium

    Science.gov (United States)

    Przedborski, Michelle; Sen, Surajit; Harroun, Thad

    Granular chains have been the focus of a number of studies, in part due to their numerous applications, ranging from shock absorption and vibration reduction to energy localization. Force impulses to an unloaded granular chain result in a propagating solitary wave (SW), analogous to a soliton of the Korteweg-de Vries equation. When SWs collide with a boundary or another SW, secondary solitary waves (SSWs) are produced as grains break contact. A consequence of this process is the transition from a non-ergodic, SW dominant, phase to the stable ``quasi-equilibrium'' (QEQ) phase, thought to be distinct from true thermodynamic equilibrium due to the absence of equipartitioning of energy. We show that, in the absence of energy dissipation, when granular systems are allowed to evolve to extremely long times, the number of SSWs becomes sufficiently large that the system actually approaches a true equilibrium phase. In this extreme-time limit, energy in fact becomes equipartitioned among all grains, and we illustrate how the specific heat and kinetic energy fluctuations can be predicted by the generalized equipartition theorem, regardless of the degree of the interaction potential. This opens up the possibility that granular systems should be treated by equilibrium statistical mechanics. This work was supported by a Vanier Canada Graduate Scholarship.

  19. Trained innate immunity as underlying mechanism for the long-term, nonspecific effects of vaccines

    DEFF Research Database (Denmark)

    Blok, Bastiaan A; Arts, Rob J W; van Crevel, Reinout

    2015-01-01

    provide protection against certain infections in vaccination models independently of lymphocytes. This process is regulated through epigenetic reprogramming of innate immune cells and has been termed "trained immunity." It has been hypothesized that induction of trained immunity is responsible...... for the protective, nonspecific effects induced by vaccines, such as BCG, measles vaccination, and other whole-microorganism vaccines. In this review, we will present the mechanisms of trained immunity responsible for the long-lasting effects of vaccines on the innate immune system....

  20. Bridge to recovery in two cases of dilated cardiomyopathy after long-term mechanical circulatory support

    OpenAIRE

    Pacholewicz, Jerzy; Zakliczyński, Michał; Kowalik, Violetta; Nadziakiewicz, Paweł; Kowalski, Oskar; Kalarus, Zbigniew; Zembala, Marian

    2014-01-01

    Ventricular assist devices (VADs) have become an established therapeutic option for patients with end-stage heart failure. Achieving the potential for recovery of native heart function using VADs is an established form of treatment in a selected group of patients with HF. We report two cases of VAD patients with different types of pump used for mechanical circulatory support, a continuous flow pump (Heart-Ware®) and a pulsatile pump (POLVAD MEV®), which allow regeneration of the native heart....

  1. Rape-related symptoms in adolescents: short- and long-term outcome after cognitive behavior group therapy

    Directory of Open Access Journals (Sweden)

    Iva Bicanic

    2014-06-01

    Full Text Available Background: Efficacy studies on treatment in adolescent victims of single rape are lacking, even though sexual victimization is most likely to occur during adolescence and despite the fact that adolescents are at risk to develop subsequent posttraumatic stress disorder. Aim: The aim of this prospective observational study was to evaluate the short- and long-term outcomes of a nine-session cognitive behavior group therapy (STEPS, including a parallel six-session parents’ group on rape-related symptomatology in female adolescents (13–18 years. STEPS includes psychoeducation, exposure in sensu as well as in vivo, cognitive restructuring, and relapse prevention. Methods: Fifty-five female adolescents with mental health problems due to single rape, but without prior sexual trauma, received STEPS while their parents participated in a support group. Subjects were assessed on posttraumatic stress (PTS and comorbid symptoms using self-report questionnaires prior to and directly after treatment, and at 6 and 12 months follow-up. Results: Repeated measures analysis showed a significant and large decrease in symptoms of PTS, anxiety, depression, anger, dissociation, sexual concerns, and behavior problems directly after treatment, which maintained at 12 months follow-up. Time since trauma did not influence the results. Dropout during STEPS was 1.8%. Conclusions: The results potentially suggest that the positive treatment outcomes at short- and long-term may be caused by STEPS. The encouraging findings need confirmation in future controlled studies on the effectiveness of STEPS because it may be possible that the treatment works especially well for more chronic symptoms, while the less chronic part of the sample showed considerable improvement on its own.

  2. Microstructure and Mechanical Properties of CrMoV Steel after Long-Term Service

    Directory of Open Access Journals (Sweden)

    Golański G.

    2016-03-01

    Full Text Available The paper presents the results of research on the microstructure and mechanical properties of 12HMF steel after longterm service. The investigated material was taken from a pipeline with circumferential welded joint after 419 988 hours of service at the temperature of 490°C, steam pressure 8 MPa. Performed research has shown that the 12HMF steel after service was characterized by a typical microstructure for this grade of steel, that is a ferritic-bainitic microstructure without any visible advanced processes of its degradation. The investigation of mechanical properties has shown that the examined steel after service was characterized by a very low impact energy KV, and yield strength lower than the required minimum. Whilst tensile strength and yield strength determined at elevated temperature was higher and similar to the standard requirements, respectively. It has been proved that the main cause of an increase in brittleness and a decrease in yield strength of the examined steel should be seen in the segregation of phosphorus to grain boundaries and the formation of precipitate free zones near the boundaries.

  3. The long-term effects of superovulation on fertility and sexual behavior of male offspring in mice.

    Science.gov (United States)

    Wei, Zeng-Tao; Lu, Xi-Lan; Zhang, Gang; Yu, Jing; Li, Hua; Jia, Gui-Hua; Li, Jun-Tao; Zhang, Jian-Min

    2014-05-01

    To evaluate the long-term effects of superovulation on fertility and sexual behavior of male offspring in mice. The mice were superovaluted, and the fertility of male offspring (F1 generation and F2 generation) were evaluated in terms of the percentage of plugs and pregnancies, serum testosterone concentrations, and sperm motility. Furthermore, the sexual behavior of male offspring and sex ratio (F1 generation and F2 generation) were measured. There were no significant differences in the percentage of plug and pregnancies, serum testosterone concentrations, sperm motilities and sex ratio between the offspring in naturally conceived group and superovulation groups (both F1 generation and F2 generation). The sperm hyperactivity at 90 min after incubation of F1 generation in naturally conceived group were higher than that of F1 generation in superovulation group, but the differences did not reach statistical significance. The offspring produced by superovaluted oocytes (both F1 generation and F2 generation) did not exhibit significant alterations in sexual behavior. No significant alterations were found in fertility and sexual behavior of male offspring in mice produced by superovaluted oocytes compared with those of naturally conceived offspring.

  4. Long-term corrosion of rebars embedded in aerial and hydraulic binders - Mechanisms and crucial physico-chemical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Chitty, Walter-John; Berger, Pascal [Laboratoire Pierre Suee, CEA/CNRS, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Dillmann, Philippe [Laboratoire Pierre Suee, CEA/CNRS, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Institut de Recherches sur les Archeomateriaux, LMC, UMR 5060, CNRS (France)], E-mail: philippe.dillmann@cea.fr; L' Hostis, Valerie [Laboratoire d' Etude du Comportement des Betons et Argiles, CEA Saclay, 91191 Gif-sur-Yvette cedex (France)

    2008-08-15

    The prediction of long-term behaviour of reinforced concrete structures involved in the nuclear industry requires the comprehension of the mechanism involved in long-term corrosion. Yet, studies on archeological artefacts allowed to identify a typical layout constituted of four layers: the metal, the dense product layer (DPL), the transformed medium (TM) and the binder. Oxygen reaction sites were labelled using oxygen 18 ({sup 18}O) and it was evidenced that the cathodic sites are located at the metal/dense product layer interface. So, oxygen has to crossed the DPL to react at the M/DPL interface or inside the marblings, and measurements of the effective tritiated water (2.6 {+-} 0.1 x 10{sup -11} m{sup 2}/s) and iodide (1.0 {+-} 0.3 x 10{sup -11} m{sup 2}/s) diffusivity of this layer saturated with water were made. Indeed, these two molecules have a diffusivity in water very closed to oxygen diffusivity.

  5. Long-term effects of early life stress exposure: Role of epigenetic mechanisms.

    Science.gov (United States)

    Silberman, Dafne M; Acosta, Gabriela B; Zorrilla Zubilete, María A

    2016-07-01

    Stress is an adaptive response to demands of the environment and thus essential for survival. Exposure to stress during the first years of life has been shown to have profound effects on the growth and development of an adult individual. There are evidences demonstrating that stressful experiences during gestation or in early life can lead to enhanced susceptibility to mental disorders. Early-life stress triggers hypothalamic-pituitary-adrenocortical (HPA) axis activation and the associated neurochemical reactions following glucocorticoid release are accompanied by a rapid physiological response. An excessive response may affect the developing brain resulting in neurobehavioral and neurochemical changes later in life. This article reviews the data from experimental studies aimed to investigate hormonal, functional, molecular and epigenetic mechanisms involved in the stress response during early-life programming. We think these studies might prove useful for the identification of novel pharmacological targets for more effective treatments of mental disorders.

  6. Mechanical Flexibility Reduces the Foreign Body Response to Long-Term Implanted Microelectrodes in Rabbit Cortex

    Science.gov (United States)

    Sohal, Harbaljit S.; Clowry, Gavin J.

    2016-01-01

    Micromotion between the brain and implanted electrodes is a major contributor to the failure of invasive microelectrodes. Movements of the electrode tip cause recording instabilities while spike amplitudes decline over the weeks/months post-implantation due to glial cell activation caused by sustained mechanical trauma. We compared the glial response over a 26–96 week period following implantation in the rabbit cortex of microwires and a novel flexible electrode. Horizontal sections were used to obtain a depth profile of the radial distribution of microglia, astrocytes and neurofilament. We found that the flexible electrode was associated with decreased gliosis compared to the microwires over these long indwelling periods. This was in part due to a decrease in overall microgliosis and enhanced neuronal density around the flexible probe, especially at longer periods of implantation. PMID:27788240

  7. Challenges in long-term mechanical circulatory support and biological replacement of the failing heart.

    Science.gov (United States)

    Lala, Anuradha; Joyce, Emer; Groarke, John D; Mehra, Mandeep R

    2014-01-01

    The burden of advanced heart failure is reaching epidemic proportions. Generally considered for cardiac transplantation, patients often cannot receive this therapy because of their advanced age, comorbidity or the scarcity of donors. Most transplants are concentrated in North America and Europe, with the average center performing fewer than 20 annual transplants. A search for nonbiological means of cardiac support has led to the advent of mechanical circulatory support (MCS), a concept now entrenched as a bridge to transplantation or, for those ineligible for transplantation, as lifetime therapy. In this review we discuss contemporary challenges posed by the changing epidemiology of cardiac transplant and MCS and outline the basis for an understanding of the future of this important therapeutic stance.  

  8. Role of long-term mechanical circulatory support in patients with advanced heart failure.

    Science.gov (United States)

    Stokes, M B; Bergin, P; McGiffin, D

    2016-05-01

    Advanced heart failure represents a small proportion of patients with heart failure that possess high-risk features associated with high hospital readmission rates, significant functional impairment and mortality. Identification of those who have progressed to, or are near a state of advanced heart failure should prompt referral to a service that offers therapies in mechanical circulatory support (MCS) and cardiac transplantation. MCS has grown as a management strategy in the care of these patients, most commonly as a bridge to cardiac transplantation. The predominant utilisation of MCS is implantation of left ventricular assist devices (LVAD), which have evolved significantly in their technology and application over the past 15-20 years. The technology has evolved to such an extent that Destination Therapy is now being utilised as a strategy in management of advanced heart failure in appropriately selected patients. Complication rates have decreased with VAD implantation, but remain a significant consideration in the decision to implant a device, and in the follow up of these patients.

  9. Modulation of learning and memory by cytokines: signaling mechanisms and long term consequences.

    Science.gov (United States)

    Donzis, Elissa J; Tronson, Natalie C

    2014-11-01

    This review describes the role of cytokines and their downstream signaling cascades on the modulation of learning and memory. Immune proteins are required for many key neural processes and dysregulation of these functions by systemic inflammation can result in impairments of memory that persist long after the resolution of inflammation. Recent research has demonstrated that manipulations of individual cytokines can modulate learning, memory, and synaptic plasticity. The many conflicting findings, however, have prevented a clear understanding of the precise role of cytokines in memory. Given the complexity of inflammatory signaling, understanding its modulatory role requires a shift in focus from single cytokines to a network of cytokine interactions and elucidation of the cytokine-dependent intracellular signaling cascades. Finally, we propose that whereas signal transduction and transcription may mediate short-term modulation of memory, long-lasting cellular and molecular mechanisms such as epigenetic modifications and altered neurogenesis may be required for the long lasting impact of inflammation on memory and cognition. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Biochemical and behavioral effects of long-term citalopram administration and discontinuation in rats Role of serotonin synthesis

    NARCIS (Netherlands)

    Bosker, Fokko J.; Tanke, Marit A. C.; Jongsma, Minke E.; Cremers, Thomas I. F. H.; Jagtman, Evelien; Pietersen, Charmaine Y.; van der Hart, Marieke G. C.; Gladkevich, Anatoliy V.; Kema, Ido P.; Westerink, Ben H. C.; Korf, Jakob; den Boer, Johan A.

    2010-01-01

    We have investigated effects of continuous SSRI administration and abrupt discontinuation on biochemical and behavioral indices of rat brain serotonin function and attempted to identify underlying mechanisms Biochemistry of serotonin was assessed with brain tissue assays and microdialysis behavior w

  11. Long-term and real-time monitoring of chondrocyte behavior synthesizing extracellular matrix with biologically coupled field effect transistor

    Science.gov (United States)

    Satake, Hiroto; Saito, Akiko; Mizuno, Shuichi; Kajisa, Taira; Sakata, Toshiya

    2017-04-01

    In this study, we report the differential measurement method of accurately monitoring cellular metabolism with a semiconductor-based field effect transistor (FET), focusing on the proliferation potency of chondrocytes utilized in the field of orthopedics. By adding growth factors to chondrocytes on the gate, cellular activity was induced and continuously monitored as a change in pH during a cellular respiration for ten days using the FET biosensor. Moreover, the electrical signal of the FET device reflected the reproduction property of chondrocytes to synthesize extracellular matrix (ECM). A platform based on the FET device is suitable as a noninvasive, real-time and long-term monitoring system for cellular functions; it will contribute to the elucidation of the mechanism of ECM synthesis by chondrocytes.

  12. Expression of HSPs: an adaptive mechanism during long-term heat stress in goats ( Capra hircus)

    Science.gov (United States)

    Dangi, Satyaveer Singh; Gupta, Mahesh; Dangi, Saroj K.; Chouhan, Vikrant Singh; Maurya, V. P.; Kumar, Puneet; Singh, Gyanendra; Sarkar, Mihir

    2015-08-01

    Menacing global rise in surface temperature compelled more focus of research over understanding heat stress response mechanism of animals and mitigation of heat stress. Twenty-four goats divided into four groups ( n = 6) such as NHS (non-heat-stressed), HS (heat-stressed), HS + VC (heat-stressed administered with vitamin C), and HS + VE + Se (heat-stressed administered with vitamin E and selenium). Except NHS group, other groups were exposed to repeated heat stress (42 °C) for 6 h on 16 consecutive days. Blood samples were collected at the end of heat exposure on days 1, 6, 11, and 16. When groups compared between days, expression of all heat shock proteins (HSPs) showed a similar pattern as first peak on day 1, reached to basal level on the sixth day, and followed by second peak on day 16. The relative messenger RNA (mRNA) and protein expression of HSP 60, HSP70, and HSP90 was observed highest ( P < 0.05) in HS group, followed by antioxidant-administered group on days 1 and 16, which signifies that antioxidants have dampening effect on HSP expression. HSP105/110 expression was highest ( P < 0.05) on day 16. We conclude that HSP expression pattern is at least two-peak phenomenon, i.e., primary window of HSP protection on the first day followed by second window of protection on day 16. HSP60, HSP70, and HSP90 play an important role during the initial phase of heat stress acclimation whereas HSP105/110 joins this cascade at later phase. Antioxidants may possibly attenuate the HSP expression by reducing the oxidative stress.

  13. Bridge to recovery in two cases of dilated cardiomyopathy after long-term mechanical circulatory support.

    Science.gov (United States)

    Pacholewicz, Jerzy; Zakliczyński, Michał; Kowalik, Violetta; Nadziakiewicz, Paweł; Kowalski, Oskar; Kalarus, Zbigniew; Zembala, Marian

    2014-06-01

    Ventricular assist devices (VADs) have become an established therapeutic option for patients with end-stage heart failure. Achieving the potential for recovery of native heart function using VADs is an established form of treatment in a selected group of patients with HF. We report two cases of VAD patients with different types of pump used for mechanical circulatory support, a continuous flow pump (Heart-Ware(®)) and a pulsatile pump (POLVAD MEV(®)), which allow regeneration of the native heart. Patients were qualified as INTERMACS level 3-4 for elective implantation of an LVAD. Implantations were performed without complications. The postoperative course was uncomplicated. In the HeartWare patient the follow-up was complicated by episodes of epistaxis and recurrent GIB as well as driveline infection. The follow-up of the POLVAD MEV patient was uneventful. Recurrent GIB forced us to withdraw aspirin and warfarin therapy and maintain only clopidogrel in the HeartWare patient.. In mid-February 2013 the patient was admitted due to dysfunction of the centrifugal pump with a continuous low-flow alarm and increase power consumption. Under close monitoring of the patient a decision was made to stop the pump immediately and evaluate cardiac function. The serial echocardiography studies showed significant improvement in LVEF up to 45% and no significant valvular pathology. In February 2013 LVAD explant was performed by left thoracotomy without complications. At six-month follow-up the patient was in a good clinical condition, in NYHA class I/II, and on pharmacological treatment.

  14. Compound stimulus presentation and the norepinephrine reuptake inhibitor atomoxetine enhance long-term extinction of cocaine-seeking behavior.

    Science.gov (United States)

    Janak, Patricia H; Bowers, M Scott; Corbit, Laura H

    2012-03-01

    Drug abstinence is frequently compromised when addicted individuals are re-exposed to environmental stimuli previously associated with drug use. Research with human addicts and in animal models has demonstrated that extinction learning (non-reinforced cue-exposure) can reduce the capacity of such stimuli to induce relapse, yet extinction therapies have limited long-term success under real-world conditions (Bouton, 2002; O'Brien, 2008). We hypothesized that enhancing extinction would reduce the later ability of drug-predictive cues to precipitate drug-seeking behavior. We, therefore, tested whether compound stimulus presentation and pharmacological treatments that augment noradrenergic activity (atomoxetine; norepinephrine reuptake inhibitor) during extinction training would facilitate the extinction of drug-seeking behaviors, thus reducing relapse. Rats were trained that the presentation of a discrete cue signaled that a lever press response would result in cocaine reinforcement. Rats were subsequently extinguished and spontaneous recovery of drug-seeking behavior following presentation of previously drug-predictive cues was tested 4 weeks later. We find that compound stimulus presentations or pharmacologically increasing noradrenergic activity during extinction training results in less future recovery of responding, whereas propranolol treatment reduced the benefit seen with compound stimulus presentation. These data may have important implications for understanding the biological basis of extinction learning, as well as for improving the outcome of extinction-based therapies.

  15. Creep Behavior of Glass/Ceramic Sealant and its Effect on Long-term Performance of Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenning N.; Sun, Xin; Koeppel, Brian J.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2009-10-14

    The creep behavior of glass or glass-ceramic sealant materials used in solid oxide fuel cells (SOFCs) becomes relevant under SOFC operating temperatures. In this paper, the creep of glass-ceramic sealants was experimentally examined, and a standard linear solid model was applied to capture the creep behavior of glass ceramic sealant materials developed for planar SOFCs at high temperatures. The parameters of this model were determined based on the creep test results. Furthermore, the creep model was incorporated into finite-element software programs SOFC-MP and Mentat-FC developed at Pacific Northwest National Laboratory for multi-physics simulation of SOFCs. The effect of creep of glass ceramic sealant materials on the long-term performance of SOFC stacks was investigated by studying the stability of the flow channels and the stress redistribution in the glass seal and on the various interfaces of the glass seal with other layers. Finite element analyses were performed to quantify the stresses in various parts. The stresses in glass seals were released because of creep behavior during operations.

  16. Community-based behavioral weight-loss treatment: long-term maintenance of weight loss, physiological, and psychological outcomes.

    Science.gov (United States)

    Latner, Janet D; Ciao, Anna C; Wendicke, Annemarie U; Murakami, Jessica M; Durso, Laura E

    2013-08-01

    Obesity is a significant public health problem, and sustainable long-term treatments are needed. This study examined a community-based model of weight-loss treatment. Ninety participants were recruited from eight community organizations (mean age: 49.65 years, mean body mass index: 35.80 kg/m(2); 64% female). Treatment groups were randomly assigned to two maintenance conditions: 1) self-help continuing care, or 2) assessment-only. Both received the same initial 20-session group behavioral treatment. Those randomized to continuing care were additionally instructed to meet as self-sustaining groups for 18 months post-treatment. Weight, physiological, behavioral, and psychological outcomes were assessed at baseline, post-treatment, and at six-month and 18-month follow-up. Eighty-seven percent of participants completed treatment. Participant treatment satisfaction and therapist adherence to treatment protocol were high. No group differences or time by group interaction effects emerged. Participants achieved significant weight losses at post-treatment, with no significant weight regain at six-month or 18-month follow-up. Treatment produced sustained changes in waist circumference, cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, insulin, eating patterns, physical activity, quality of life, and body image. A community-based treatment program may be an effective form of behavioral-weight-loss treatment for overweight/obese adults. Weight losses, along with physiological and psychological benefits, were sustained over time. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Improving effects of long-term growth hormone treatment on monoaminergic neurotransmission and related behavioral tests in aged rats.

    Science.gov (United States)

    Esteban, Susana; Garau, Celia; Aparicio, Sara; Moranta, David; Barceló, Pere; Ramis, Margarita; Tresguerres, Jesús A F; Rial, Rubén

    2010-12-01

    An age-related decline in cognitive functions and physical performance has been associated with reductions in growth hormone (GH) secretion and brain neurotransmitter function. In vivo experiments were performed to study the long-term effects of exogenously administered GH on the central monoaminergic neurotransmitters serotonin, dopamine, and noradrenaline and behavioral tests in old Wistar rats. The accumulation of 5-hydroxytryptophan (5-HTP) and L-3,4-dihydroxyphenylalanine (DOPA) after decarboxylase inhibition was used as a measure of the rate of tryptophan and tyrosine hydroxylation in vivo. Also, the content of the neurotransmitters serotonin, dopamine, and noradrenaline and some metabolites was measured by high-pressure liquid chromatography (HPLC) in the hippocampus and striatum, brain regions involved in adult memory processing and motor coordination. The age-related decline observed in all the neurochemical parameters in control rats was significantly reversed after repeated subcutaneous administration of GH (2 mg/kg per day, 4 weeks). Thus, GH treatment exerted a long-term effect on serotonin, dopamine, and noradrenaline neurotransmission by enhancing neurotransmitter synthesis and metabolism in aged rats. The results obtained after examining working memory tasks in the eight-radial maze and motor ability in the Rotarod treadmill in aged rats were consistent with these neurochemical data; both tests were significantly improved after chronic GH treatment. Overall, these in vivo findings suggest that the positive effects induced by GH on serotonin, dopamine, and noradrenaline neurotransmitters might explain, at least in part, the effects of chronic GH treatment in improving cognitive and motor ability in aged rats, and could aid in preventing or delaying deficits in monoamines associated with learning or motor disabilities.

  18. Relationship between Physical Disabilities or Long-Term Health Problems and Health Risk Behaviors or Conditions among US High School Students

    Science.gov (United States)

    Jones, Sherry Everett; Lollar, Donald J.

    2008-01-01

    Background: This study explores the relationship between self-reported physical disabilities or long-term health problems and health risk behaviors or adverse health conditions (self-reported engagement in violent behaviors, attempted suicide, cigarette smoking, alcohol and other drug use, sexual activity, physical activity, dietary behaviors,…

  19. Sharpened cortical tuning and enhanced cortico-cortical communication contribute to the long-term neural mechanisms of visual motion perceptual learning.

    Science.gov (United States)

    Chen, Nihong; Bi, Taiyong; Zhou, Tiangang; Li, Sheng; Liu, Zili; Fang, Fang

    2015-07-15

    Much has been debated about whether the neural plasticity mediating perceptual learning takes place at the sensory or decision-making stage in the brain. To investigate this, we trained human subjects in a visual motion direction discrimination task. Behavioral performance and BOLD signals were measured before, immediately after, and two weeks after training. Parallel to subjects' long-lasting behavioral improvement, the neural selectivity in V3A and the effective connectivity from V3A to IPS (intraparietal sulcus, a motion decision-making area) exhibited a persistent increase for the trained direction. Moreover, the improvement was well explained by a linear combination of the selectivity and connectivity increases. These findings suggest that the long-term neural mechanisms of motion perceptual learning are implemented by sharpening cortical tuning to trained stimuli at the sensory processing stage, as well as by optimizing the connections between sensory and decision-making areas in the brain.

  20. A model of the mechanism of cooperativity and associativity of long-term potentiation in the hippocampus: a fundamental mechanism of associative memory and learning.

    Science.gov (United States)

    Kitajima, T; Hara, K

    1991-01-01

    Long-Term Potentiation (LTP) has three properties: (1) input specificity, (2) cooperativity and (3) associativity. In a previous paper, we proposed an integrated model of the mechanisms of the induction and maintenance of LTP with input specificity. In this paper, a model of the mechanism of cooperative and associative LTP is described. According to computer simulations of the model, its mechanism is based on the spread of synaptic potentials.

  1. Mechanisms of induction and expression of long-term depression at GABAergic synapses in the neonatal rat hippocampus.

    Science.gov (United States)

    Caillard, O; Ben-Ari, Y; Gaïarsa, J L

    1999-09-01

    Synaptic plasticity at excitatory glutamatergic synapses is believed to be instrumental in the maturation of neuronal networks. Using whole-cell patch-clamp recordings, we have studied the mechanisms of induction and expression of long-term depression at excitatory GABAergic synapses in the neonatal rat hippocampus (LTD(GABA-A)). We report that the induction of LTD(GABA-A) requires a GABA(A) receptor-mediated membrane depolarization, which is necessary to remove the Mg(2+) block from postsynaptic NMDA receptors. LTD(GABA-A) is associated with an increase in the coefficient of variation of evoked GABA(A) receptor-mediated synaptic currents and a decrease in the frequency, but not amplitude, of Sr(2+)-induced asynchronous GABA(A) quantal events. We conclude that LTD(GABA-A) induction requires the activation of both GABA(A) and NMDA postsynaptic receptors and that its expression is likely presynaptic.

  2. A relationship between reduced nucleus accumbens shell and enhanced lateral hypothalamic orexin neuronal activation in long-term fructose bingeing behavior.

    Directory of Open Access Journals (Sweden)

    Jacki M Rorabaugh

    Full Text Available Fructose accounts for 10% of daily calories in the American diet. Fructose, but not glucose, given intracerebroventricularly stimulates homeostatic feeding mechanisms within the hypothalamus; however, little is known about how fructose affects hedonic feeding centers. Repeated ingestion of sucrose, a disaccharide of fructose and glucose, increases neuronal activity in hedonic centers, the nucleus accumbens (NAc shell and core, but not the hypothalamus. Rats given glucose in the intermittent access model (IAM display signatures of hedonic feeding including bingeing and altered DA receptor (R numbers within the NAc. Here we examined whether substituting fructose for glucose in this IAM produces bingeing behavior, alters DA Rs and activates hedonic and homeostatic feeding centers. Following long-term (21-day exposure to the IAM, rats given 8-12% fructose solutions displayed fructose bingeing but unaltered DA D1R or D2R number. Fructose bingeing rats, as compared to chow bingeing controls, exhibited reduced NAc shell neuron activation, as determined by c-Fos-immunoreactivity (Fos-IR. This activation was negatively correlated with orexin (Orx neuron activation in the lateral hypothalamus/perifornical area (LH/PeF, a brain region linking homeostatic to hedonic feeding centers. Following short-term (2-day access to the IAM, rats exhibited bingeing but unchanged Fos-IR, suggesting only long-term fructose bingeing increases Orx release. In long-term fructose bingeing rats, pretreatment with the Ox1R antagonist SB-334867 (30 mg/kg; i.p. equally reduced fructose bingeing and chow intake, resulting in a 50% reduction in calories. Similarly, in control rats, SB-334867 reduced chow/caloric intake by 60%. Thus, in the IAM, Ox1Rs appear to regulate feeding based on caloric content rather than palatability. Overall, our results, in combination with the literature, suggest individual monosaccharides activate distinct neuronal circuits to promote feeding behavior

  3. Mechanical properties and structure of the Cr-Mo-V low-alloyed steel after long-term service in creep condition

    OpenAIRE

    J. Dobrzański; A. Zieliński; H. Krztoń

    2007-01-01

    Purpose: of this paper is to present the changes of the mechanical properties and structure in material components of the power station boiler after long-term creep service made of Cr-Mo-V low-alloyed steel.Design/methodology/approach: The investigated material has been obtained from the Polish power stations. All examined elements have exceeded their assessed life of 100 000 hours. Mechanical properties and structure examinations were carried out on materials after long-term service in creep...

  4. Effects of long-term administration of omeprazole on bone mineral density and the mechanical properties of the bone☆

    Science.gov (United States)

    Yanagihara, Gabriela Rezende; de Paiva, Aline Goulart; Neto, Maurílio Pacheco; Torres, Larissa Helena; Shimano, Antônio Carlos; Louzada, Mário Jefferson Quirino; Annoni, Raquel; de Oliveira Penoni, Álvaro César

    2015-01-01

    Objectives Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD) of rats that were subjected to long-term omeprazole use. Methods Fifty Wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 μmoL/kg/day); OMP200 (200 μmoL/kg/day); OMP40 (40 μmoL/kg/day); OMP10 (10 μmoL/kg/day); and Cont (control group; intake of dilution vehicle). The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed. Results The BMD of the OMP300 group was lower than that of the controls (p = 0.006). There was no difference on comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049), but the other groups did not show any difference in relation to the controls. Conclusion Daily intake of 300 μmoL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats. PMID:26229922

  5. Effects of long-term administration of omeprazole on bone mineral density and the mechanical properties of the bone

    Directory of Open Access Journals (Sweden)

    Gabriela Rezende Yanagihara

    2015-04-01

    Full Text Available OBJECTIVES: Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD of rats that were subjected to long-term omeprazole use.METHODS: Fifty Wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 µmoL/kg/day; OMP200 (200 µmoL/kg/day; OMP40 (40 µmoL/kg/day; OMP10 (10 µmoL/kg/day; and Cont (control group; intake of dilution vehicle. The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed.RESULTS: The BMD of the OMP300 group was lower than that of the controls (p = 0.006. There was no difference on comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049, but the other groups did not show any difference in relation to the controls.CONCLUSION: Daily intake of 300 µmoL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats.

  6. Cognitive-behavioral therapy for obsessive–compulsive disorder: access to treatment, prediction of long-term outcome with neuroimaging

    Directory of Open Access Journals (Sweden)

    O’Neill J

    2015-07-01

    Full Text Available Joseph O'Neill,1 Jamie D Feusner,2 1Division of Child Psychiatry, 2Division of Adult Psychiatry, UCLA Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA, USA Abstract: This article reviews issues related to a major challenge to the field for obsessive–compulsive disorder (OCD: improving access to cognitive-behavioral therapy (CBT. Patient-related barriers to access include the stigma of OCD and reluctance to take on the demands of CBT. Patient-external factors include the shortage of trained CBT therapists and the high costs of CBT. The second half of the review focuses on one partial, yet plausible aid to improve access – prediction of long-term response to CBT, particularly using neuroimaging methods. Recent pilot data are presented revealing a potential for pretreatment resting-state functional magnetic resonance imaging and magnetic resonance spectroscopy of the brain to forecast OCD symptom severity up to 1 year after completing CBT. Keywords: follow-up, access to treatment, relapse, resting-state fMRI, magnetic resonance spectroscopy

  7. Lack of long-term behavioral alterations after early postnatal treatment with tropisetron: implications for developmental psychobiology.

    Science.gov (United States)

    Inta, Dragos; Vogt, Miriam A; Lima-Ojeda, Juan M; Pfeiffer, Natascha; Schneider, Miriam; Gass, Peter

    2011-07-01

    The early postnatal period represents a critical time window for brain development. Transient Cajal-Retzius cells in layer I of the cortex play an important role in cortical lamination by modulating neuronal migration and maturation. Recent data have demonstrated that the 5-HT(3) receptor antagonist and alpha7 nicotinic receptor partial agonist tropisetron, acting via 5-HT(3) receptors expressed on Cajal-Retzius cells, can disturb the formation of cortical columns at perinatal stages. This process is thought to be involved in several neuropsychiatric disorders. Here we investigated the possible long-term behavioral effects of exposure to tropisetron at early postnatal stages in mice. We found that the administration of 1mg/kg, intraperitoneal (i.p.) tropisetron from postnatal days 2-12 (P2-P12) did not induce significant cognitive, schizophrenia-like or emotional alterations in tropisetron-treated animals as compared to controls, when tested in multiple behavioral assays. These results may be of relevance regarding the possible protracted deleterious neuropsychiatric effects of tropisetron during early life.

  8. Long-term leaching behavior of phenol in cement/activated-carbon solidified/stabilized hazardous waste.

    Science.gov (United States)

    Liu, Jianguo; Nie, Xiaoqin; Zeng, Xianwei; Su, Zhaoji

    2013-01-30

    The long-term leaching behavior of phenol in solidified/stabilized (S/S) hazardous wastes cured for 28 d with different amounts of activated carbon (AC) was investigated using synthetic inorganic acid (H(2)SO(4):HNO(3) = 2:1, pH = 3.2), acetic acid buffer (HAc/NaAc, pH = 4.93), and deionized water as leachants to simulate the leaching of phenol in three exposure scenarios: acid-precipitation, co-disposal, and neutral-precipitation. Phenol immobilization was enhanced by AC adsorption and impaired by the growth of micropores with increasing amount of AC; thus the optimal added amount of AC to be to added S/S wastes was 2%. The leaching behavior of phenol in co-disposal scenario was unpredictable due to inadequate ionization of HAc in the HAc-NaAc buffer solution. The findings indicated that S/S products should be disposed of in hazardous waste landfills rather than municipal solid waste landfills.

  9. Long-term survival in elderly patients with a do-not-intubate order treated with noninvasive mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Riario-Sforza GG

    2011-04-01

    Full Text Available Paolo Scarpazza1, Cristoforo Incorvaia2, Paolo Amboni3, Giuseppe di Franco1, Stefania Raschi1, Pierfranco Usai1, Monica Bernareggi1, Cristiano Bonacina1, Chiara Melacini1, Roberta Cattaneo1, Serena Bencini1, Chiara Pravettoni2, Gian Galeazzo Riario-Sforza2, Gianni Passalacqua4, Walter Casali11Divisione di Broncopneumotisiologia, Ospedale Civile, Vimercate, Italy; 2Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy; 3Clinical Chemistry Laboratory, Ospedali Riuniti, Bergamo, Italy; 4Allergy and Respiratory Diseases, University Of Genoa, Genoa, ItalyBackground: Noninvasive mechanical ventilation (NIMV is an effective tool in treating patients with acute respiratory failure (ARF, since it reduces both the need for endotracheal intubation and the mortality in comparison with nonventilated patients. A particular issue is represented by the outcome of NIMV in patients referred to the emergency department for ARF and with a do-not-intubate (DNI status because of advanced age or excessively critical conditions. This study evaluated long-term survival in a group of elderly patients with acute hypercapnic ARF who had a DNI order and who were successfully treated by NIMV.Methods: The population consisted of 54 patients with a favorable outcome after NIMV for ARF. They were followed up for 3 years by regular control visits, with at least one visit every 4 months, or as needed according to the patient’s condition. Of these, 31 continued NIMV at home and 23 were on long-term oxygen therapy (LTOT alone.Results: A total of 16 of the 52 patients had not survived at the 1-year follow-up, and another eight patients died during the 3-year observation, with an overall mortality rate of 30.8% after 1 year and 46.2% after 3 years. Comparing patients who continued NIMV at home with those who were on LTOT alone, 9 of the 29 patients on home NIMV died (6 after 1 year and 3 after 3 years and 15 of the 23 patients on LTOT alone died (10 after 1

  10. Improvement in Long-Term Memory following Chronic Administration of Eryngium planum Root Extract in Scopolamine Model: Behavioral and Molecular Study

    Directory of Open Access Journals (Sweden)

    Marcin Ozarowski

    2015-01-01

    Full Text Available Eryngium planum L. (EP is as a rare medicinal plant with a lot of potentials as pharmaceutical crops. The aim of our study was to assess the effect of subchronic (28-fold administration of a 70% ethanol extract of EP roots (200 mg/kg, p.o. on behavioral and cognitive responses in Wistar rats linked with acetylcholinesterase (AChE, butyrylcholinesterase (BuChE, and beta-secretase (BACE-1 mRNA levels and AChE and BuChE activities in the hippocampus and frontal cortex. On the last day of experiment, 30 min after the last dose of EP or Huperzine A (HU, scopolamine (SC was given at a dose of 0.5 mg/kg b.w. intraperitoneally. The results of a passive avoidance test showed an improvement in long-term memory produced by the EP extract in both scopolamine-induced rats and control group. EP caused an insignificant inhibition of AChE and BuChE activities in the frontal cortex and the hippocampus. EP decreased mRNA AChE, BuChE, and BACE-1 levels, especially in the cortex. Our results suggest that the EP extract led to the improvement of the long-term memory in rats coupled with total saponin content. The mechanism of EP action is probably complicated, since HPLC-MS analysis showed 64 chemical compounds (phenolics, saponins in the extract of EP roots.

  11. Pairing behavior and reproduction in Hyalella azteca as sensitive endpoints for detecting long-term consequences of pesticide pulses.

    Science.gov (United States)

    Pedersen, Signe; Palmqvist, Annemette; Thorbek, Pernille; Hamer, Mick; Forbes, Valery

    2013-11-15

    The aim of the present study was to examine acute and delayed effects of pulse exposure of the pyrethroid pesticide, permethrin, on precopulatory pairs of Hyalella azteca. Pairs of H. azteca were exposed to a single 1h pulse of different nominal concentrations of permethrin: 0, 0.3, 0.9 or 2.7 μg/L. During exposure, pairing behavior was observed, and during a 56 day post-exposure period the treatments were monitored for pairing behavior, survival and reproductive output. All permethrin-exposed pairs separated within minutes during exposure and shortly thereafter became immobile; however they regained mobility after transfer to clean water. The time to re-form pairs was significantly longer in all tested concentrations compared to the control, although all surviving pairs re-formed within the 56 day test period. Nevertheless not all pairs exposed to 0.9 and 2.7 μg/L reproduced. Furthermore the numbers of juveniles produced by pairs exposed to 0.9 and 2.7 μg/L, but not 0.3 μg/L, were lower throughout the entire post-exposure period compared to the control groups, and the total numbers of juveniles produced during 56 days were significantly lower in organisms exposed to 0.9 and 2.7 μg/L, but not 0.3 μg/L, compared to the control groups. The long-term effects of short-term exposure on reproductive behavior of pairs could potentially have consequences for the population dynamics of H. azteca. However, since individual-level responses can both overestimate and underestimate effects at the population level, appropriate population models are needed to reduce the uncertainty in extrapolating between these levels of biological organization.

  12. Prior Exposure to Interpersonal Violence and Long-term Treatment Response for Boys with a Disruptive Behavior Disorder

    Science.gov (United States)

    Shenk, Chad E.; Dorn, Lorah D.; Kolko, David J.; Rausch, Joseph R.; Insana, Salvatore P.

    2016-01-01

    Interpersonal violence (IPV) is common in children with a disruptive behavior disorder (DBD) and increases the risk for greater DBD symptom severity, callous-unemotional (CU) traits, and neuroendocrine disruption. Thus, IPV may make it difficult to change symptom trajectories for families receiving DBD interventions given these relationships. The current study examined whether IPV prior to receiving treatment for a DBD predicted trajectories of a variety of associated outcomes, specifically DBD symptoms, CU traits, and cortisol concentrations. Boys with a DBD diagnosis (N = 66; age range = 6-11 years; 54.5% of whom experienced IPV prior to treatment) of either oppositional defiant disorder or conduct disorder participated in a randomized clinical trial and were assessed 3 years following treatment. Multilevel modeling demonstrated that prior IPV predicted smaller rates of change in DBD symptoms, CU traits, and cortisol trajectories, indicating less benefit from intervention. The effect size magnitudes of IPV were large for each outcome (d = 0.88 – 1.07). These results suggest that IPV is a predictor of the long-term treatment response for boys with a DBD. Including trauma-focused components into existing DBD interventions may be worth testing to improve treatment effectiveness for boys with a prior history of IPV. PMID:25270151

  13. Long-term behavioral change as a result of acute ethanol exposure in zebrafish: Evidence for a role for sonic hedgehog but not retinoic acid signaling.

    Science.gov (United States)

    Burton, Derek F; Zhang, Chengjin; Boa-Amponsem, Oswald; Mackinnon, Shanta; Cole, Gregory J

    2017-05-01

    Developmental exposure to ethanol is recognized to produce long-term neurobehavioral impairment in multiple animal models. However, the molecular mechanisms underlying these deficits remain poorly understood. The present study was undertaken to ascertain whether two well-characterized targets of prenatal alcohol exposure, sonic hedgehog (Shh) and retinoic acid (RA), that induce the hallmark morphological phenotypes of fetal alcohol spectrum disorders (FASD), are involved in the generation of behavioral alterations as a result of alcohol exposure. Zebrafish embryos were exposed to ethanol (0%, 1%, 3%) at either 8-10 or 24-27h post-fertilization (hpf) and then evaluated during adolescence in the novel tank dive test to assess anxiety and risk-taking behavior. Overt signs of dysmorphogenesis were also scored and behavioral and morphological changes were compared for embryos treated with alcohol alone or in combination with subthreshold doses of shh or alhh1a3 morpholinos (MOs). Ethanol treated fish displayed altered tank diving behavior that was not exacerbated by combined MO treatment. While treatment of embryos with either shha mRNA or RA prior to ethanol exposure only ameliorated the altered tank diving response in the case of shha mRNA overexpression, dysmorphogenesis was rescued by both treatments. These results suggest that the effects of ethanol exposure on changes in anxiety and risk-taking behavior in adolescent zebrafish is manifested by a blunting of Shh, but not RA, signaling during early development. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Long-Term Home Noninvasive Mechanical Ventilation Increases Systemic Inflammatory Response in Chronic Obstructive Pulmonary Disease: A Prospective Observational Study

    Directory of Open Access Journals (Sweden)

    Gregorino Paone

    2014-01-01

    Full Text Available Background. Long-term home noninvasive mechanical ventilation (NIV is beneficial in COPD but its impact on inflammation is unknown. We assessed the hypothesis that NIV modulates systemic and pulmonary inflammatory biomarkers in stable COPD. Methods. Among 610 patients referred for NIV, we shortlisted those undergoing NIV versus oxygen therapy alone, excluding subjects with comorbidities or non-COPD conditions. Sputum and blood samples were collected after 3 months of clinical stability and analyzed for levels of human neutrophil peptides (HNP, interleukin-6 (IL-6, interleukin-10 (IL-10, and tumor necrosis factor-alpha (TNF-alpha. Patients underwent a two-year follow-up. Unadjusted, propensity-matched, and pH-stratified analyses were performed. Results. Ninety-three patients were included (48 NIV, 45 oxygen, with analogous baseline features. Sputum analysis showed similar HNP, IL-6, IL-10, and TNF-alpha levels (P>0.5. Conversely, NIV group exhibited higher HNP and IL-6 systemic levels (P<0.001 and lower IL-10 concentrations (P<0.001. Subjects undergoing NIV had a significant reduction of rehospitalizations during follow-up compared to oxygen group (P=0.005. These findings were confirmed after propensity matching and pH stratification. Conclusions. These findings challenge prior paradigms based on the assumption that pulmonary inflammation is per se detrimental. NIV beneficial impact on lung mechanics may overcome the potential unfavorable effects of an increased inflammatory state.

  15. Long-term investigation of erosion behaviors on metal surfaces by impingement of liquid droplet with high-speed

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Duk Hyun; Kim, Kyung Hoon [Kyunghee University, Yongin (Korea, Republic of); Kim, Hyung Joon [Seoul National University, Seoul (Korea, Republic of)

    2015-03-15

    Understanding wall-thinning erosion of pipelines in nuclear or steam power plants is critically important for predicting and preventing human and material accidents. Wall thinning of pipelines in power plants occurs mainly by flow acceleration corrosion (FAC), cavitation erosion (C/E), and liquid droplet impingement erosion (LIE). Wall thinning by FAC and C/E has been well-investigated; however, LIE in plant industries has rarely been studied due to the experimental difficulty of setting up a long injection of highly pressurized air. We designed a long-term experimental system for LIE and investigated the behavior of LIE for three kinds of materials (A106B, SS400, A6061). The main control parameter was the air-water ratio (α), which was defined as the volumetric ratio of water to air (0.79, 1.00, 1.72). To clearly understand LIE, the spraying velocity (v) of liquid droplets was controlled larger than 160 m/s and the experiments were performed for 15 days. The surface morphology and hardness of the materials were examined every five days. Since the spraying velocity of liquid droplets and their contact area (A{sub c}) on specimens were changed according to the air-water ratio, we analyzed the behavior of LIE for the materials using the impulse (I), which was defined as I = (α × v) / A{sub c} . Finally, the prediction equations (the erosion rate) for the LIE of the materials were determined for the air-water ratios.

  16. Short- and long-term biomarkers for bacterial robustness: a framework for quantifying correlations between cellular indicators and adaptive behavior.

    Directory of Open Access Journals (Sweden)

    Heidy M W den Besten

    Full Text Available The ability of microorganisms to adapt to changing environments challenges the prediction of their history-dependent behavior. Cellular biomarkers that are quantitatively correlated to stress adaptive behavior will facilitate our ability to predict the impact of these adaptive traits. Here, we present a framework for identifying cellular biomarkers for mild stress induced enhanced microbial robustness towards lethal stresses. Several candidate-biomarkers were selected by comparing the genome-wide transcriptome profiles of our model-organism Bacillus cereus upon exposure to four mild stress conditions (mild heat, acid, salt and oxidative stress. These candidate-biomarkers--a transcriptional regulator (activating general stress responses, enzymes (removing reactive oxygen species, and chaperones and proteases (maintaining protein quality--were quantitatively determined at transcript, protein and/or activity level upon exposure to mild heat, acid, salt and oxidative stress for various time intervals. Both unstressed and mild stress treated cells were also exposed to lethal stress conditions (severe heat, acid and oxidative stress to quantify the robustness advantage provided by mild stress pretreatment. To evaluate whether the candidate-biomarkers could predict the robustness enhancement towards lethal stress elicited by mild stress pretreatment, the biomarker responses upon mild stress treatment were correlated to mild stress induced robustness towards lethal stress. Both short- and long-term biomarkers could be identified of which their induction levels were correlated to mild stress induced enhanced robustness towards lethal heat, acid and/or oxidative stress, respectively, and are therefore predictive cellular indicators for mild stress induced enhanced robustness. The identified biomarkers are among the most consistently induced cellular components in stress responses and ubiquitous in biology, supporting extrapolation to other microorganisms

  17. Long-term experience with implanted intrathecal drug administration systems for failed back syndrome and chronic mechanical low back pain

    Directory of Open Access Journals (Sweden)

    Treharne GJ

    2002-06-01

    Full Text Available Abstract Background Continuous intrathecal drug delivery has been shown in open studies to improve pain and quality of life in those with intractable back pain who have had spinal surgery. There is limited data on long term effects and and even less for patients with mechanical back pain without prior spinal surgery. Methods We have investigated spinal drug administration systems for patients with failed back syndrome and chronic mechanical low back pain by patient questionnaire study of the efficacy of this therapy and a case notes review. Results 36 patients (97% of 37 approached completed questionnaires, 24 with failed back syndrome and 12 with chronic mechanical low back pain. Recalled pre-treatment levels with current post-treatment levels of pain and a range of quality of life measures (recorded on 11-point numerical rating scales were compared. Pain improved significantly in both groups (Wilcoxan signed ranks test, p 0.005, Wilcoxan signed ranks test with Bonferroni correction. Diamorphine was used in all 37 patients, bupivacaine in 32, clonidine in 27 and baclofen in 3. The mean dose of diamorphine increased for the first 2 years but did not change 2–6 years post implant, averaging 4.5 mg/day. Revision surgery was required in 24% of cases, but reduced to 12% in the later years of our experience. Conclusions We conclude that spinal drug administration systems appear to be of benefit in alleviating pain in the failed back syndrome and chronic mechanical low back pain but need to be examined prospectively.

  18. Short-lived tectonic switch mechanism for long-term pulses of volcanic activity after mega-thrust earthquakes

    Directory of Open Access Journals (Sweden)

    M. Lupi

    2013-06-01

    Full Text Available Eruptive rates in volcanic arcs increase significantly after mega-thrust earthquakes in subduction zones. Over short to intermediate time periods the link between mega-thrust earthquakes and arc response can be attributed to dynamic triggering processes or static stress changes, but a fundamental mechanism that controls long-term pulses of volcanic activity after mega-thrust earthquakes has not been proposed yet. Using geomechanical, geological, and geophysical arguments, we propose that increased eruption rates over longer timescales are due to the relaxation of the compressional regime that accompanies mega-thrust subduction zone earthquakes. More specifically, the reduction of the horizontal stress σh promotes the occurrence of short-lived strike-slip kinematics rather than reverse faulting in the volcanic arc. The relaxation of the pre-earthquake compressional regime facilitates magma mobilization by providing a short-circuit pathway to shallow depths by significantly increasing the hydraulic properties of the system. The timescale for the onset of strike-slip faulting depends on the degree of shear stress accumulated in the arc during inter-seismic periods, which in turn is connected to the degree of strain-partitioning at convergent margins. We performed Coulomb stress transfer analysis to determine the order of magnitude of the stress perturbations in present-day volcanic arcs in response to five actual mega-thrust earthquakes; the 2005 M8.6, 2007 M8.5, and 2007 M7.9 Sumatra earthquakes; the 2010 M8.8 Maule, Chile earthquake; and the 2011 M9.0 Tohoku, Japan earthquake. We find that all, but one, the shallow earthquakes that occurred in the arcs of Sumatra, Chile and Japan show a marked lateral component. Our hypothesis suggests that the long-term response of volcanic arcs to subduction zone mega-thrust earthquakes will be manifested as predominantly strike-slip seismic events, and that these future earthquakes will be followed closely by

  19. Long-term behavioral sensitization to apomorphine is independent of conditioning and increases conditioned pecking, but not preference, in pigeons.

    Science.gov (United States)

    Anselme, Patrick; Edeş, Neslihan; Tabrik, Sepideh; Güntürkün, Onur

    2017-08-30

    When rodents are given a free choice between a variable option and a constant option, they may prefer variability. This preference is even sometimes increased following repeated administration of a dopamine agonist. The present study was the first to examine preference for variability under the systemic administration of a dopamine agonist, apomorphine (Apo), in birds. Experiment 1 tested the drug-free preference and the propensity to choose of pigeons for a constant over a variable delay. It appeared that they preferred and decided more quickly to peck at the optimal delay option. Experiment 2 assessed the effects of a repeated injection of Apo on delay preference, in comparison with previous control tests within the same individuals. Apo treatment might have decreased the number of pecks at the constant option across the different experimental phases, but failed to induce a preference for the variable option. In Experiment 3, two groups of pigeons (Apo-sensitized and saline) were used in order to avoid inhomogeneity in treatments. They had to choose between a 50% probability option and a 5-s delay option. Conditioned pecking and the propensity to choose were higher in the Apo-sensitized pigeons, but, in each group, the pigeons showed indifference between the two options. This experiment also showed that long-term behavioral sensitization to Apo can occur independently of a conditioning process. These results suggest that Apo sensitization can enhance the attractiveness of conditioned cues, while having no effect on the development of a preference for variable-delay and probabilistic schedules of reinforcement. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Precipitation behavior of Z phase after long-term creep in high chromium ferritic heat resistant steels

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, K.; Kushima, H.; Kimura, K. [National Institute for Materials Science, Tsukuba (Japan). Materials Reliability Center

    2006-07-01

    The precipitation behavior of the Z phase was investigated after long-term creep exposure in ASME-T91, T92, T122 without {delta}-ferrite, and T122 with {delta}-ferrite through elemental mapping using EF-TEM. The Z phase was identified by comparing the Cr map with the V map. Most of the Z phase was observed around prior austenite grain boundaries and/or packet boundaries in all of the steels examined. In T122 with {delta}-ferrite, the Z phase also precipitates around the {delta}-ferrite. In particular, the number of MX carbonitrides was very small in T122 with a large amount of the Z phase. The main metallic composition of the Z phase in T91 was the same as that in T92. In T122, the Z phase contained a lower Nb content. The main metallic composition of the Z phase around the {delta}-ferrite was the same as that in the other areas. There was no large difference in the size distribution of the Z phase among the steels. The mean diameter of the Z phases for T122 with {delta}-ferrite was relatively large in spite of a shorter creep exposure in contrast with T91 and T92. The number density of the Z phases increased with increasing creep exposure time except in the case of T91. The order of the number density was T122 with {delta}-ferrite, T91, T122 without {delta}-ferrite, and T92. In crept samples, the amount of Z phase in the gauge portion was higher than that in the grip portion, meaning that stress and/or strain promotes the formation of a Z phase during creep exposure. (orig.)

  1. Using Psychodynamic, Cognitive Behavioral, and Control Mastery Prototypes to Predict Change: A New Look at an Old Paradigm for Long-Term Single-Case Research

    Science.gov (United States)

    Pole, Nnamdi; Ablon, J. Stuart; O'Connor, Lynn E.

    2008-01-01

    This article illustrates a method of testing models of change in individual long-term psychotherapy cases. A depressed client was treated with 208 sessions of control mastery therapy (CMT), an unmanualized approach that integrates elements of psychodynamic therapy (PDT) and cognitive behavioral therapy (CBT). Panels of experts developed prototypes…

  2. An Immediate and Long-Term Study of a Temperament and Parent-Child Interaction Therapy Based Community Program for Preschoolers with Behavior Problems

    Science.gov (United States)

    Pade, Hadas; Taube, Daniel O.; Aalborg, Annette E.; Reiser, Paul J.

    2006-01-01

    The immediate and long-term effects of a Parent Child Interaction Therapy (PCIT) derived program offered at a Kaiser Permanente facility were evaluated. There were 73 participants in the initial sample and 23 in the 5-6 year follow-up sample. Child behaviors improved significantly immediately following treatment and some improvements were…

  3. Preventive Intervention for Preschoolers at High Risk for Antisocial Behavior: Long-Term Effects on Child Physical Aggression and Parenting Practices

    Science.gov (United States)

    Brotman, Laurie Miller; Gouley, Kathleen Kiely; Huang, Keng-Yen; Rosenfelt, Amanda; O'Neal, Colleen; Klein, Rachel G.; Shrout, Patrick

    2008-01-01

    This article presents long-term effects of a preventive intervention for young children at high risk for antisocial behavior. Ninety-two children (M age = 4 years) were randomly assigned to an 8-month family intervention or no-intervention control condition and assessed 4 times over a 24-month period. Intent-to-treat analyses revealed significant…

  4. The Short- and Long-term Effects of Simple Behavioral Interventions for Nocturnal Enuresis in Young Children : A Randomized Controlled Trial

    NARCIS (Netherlands)

    Dommelen, P. van; Kamphuis, M.; Leerdam, F.J.M. van; Wilde, J.A. de; Rijpstra, A.; Campagne, A.E.; Verkerk, P.H.

    2009-01-01

    Objective: To assess the short- and long-term effects of 3 simple behavioral interventions to overcome nocturnal enuresis in young children. Study design: We performed a randomized controlled trial in children aged four to five years with mono-symptomatic nocturnal enuresis (n = 570). The children w

  5. The Long-Term Effective Mechanism of Rural Poverty Alleviation in China from the Perspective of Ecological Management

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the ecological environmental situation of poverty-stricken areas in China and the domestic and foreign research results,the long-term effective mechanism of sustainable poverty alleviation in China is established(the ideological premise is ecological culture,the material base is ecological economy and the basic guarantee is ecological system) from the perspective of ecological management.To be specific,ecological culture,the ideological premise of rural sustainable poverty alleviation in China,includes two aspects:the first one is upholding the Marxism,passing on the Chinese traditional ecological wisdom and fostering ecological consciousness;the second one is mirroring the thought of western modern ecological ethics,emphasizing ecological criticism and redoubling the ecological education.As for ecological economy,the material guarantee for sustainable poverty alleviation in Chinese rural poverty-stricken areas,also contents two aspects.The first one is promoting the way of "clean production" and developing ecological industry;the second one is building ecological concept of consumption and establishing the ecological lifestyle.In addition,ecological system,the basic guarantee of sustainable poverty alleviation in Chinese rural poverty-stricken areas,covers three terms.The first one is implementing the ecological policies and stipulating ecological plan;the second one is establishing perfect ecological legislation and ecological system and intensifying their implementation;the third one is enforcing ecological management in the process of sustainable poverty alleviation.Through the establishment of the above mechanism,we look forward to realizing sustainability of economic development and poverty alleviation effects in the process of poverty alleviation in Chinese rural areas,as well as ecological management of the poverty-stricken areas.

  6. Long term corrosion of iron in concrete and in atmospheric conditions: a contribution of archaeological analogues to mechanism comprehension

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.; Demoulin, A.; Dillman, Ph.; Neff, D.; Berge, P. [CEA Saclay, DSM/IRAMIS, Lab. Pierre Sue, 91 - Gif-sur-Yvette (France); Burger, E.; Perrin, St. [CEA Saclay, DEN/DPC/SCCME, Lab. d' Etude de la Corrosion Aqueuse, 91 - Gif-sur-Yvette (France); L' hostis, V. [CEA Saclay, DEN/DPC/SCCME, Lab. d' Etude du Comportement des Betons et Argiles, 91 - Gif-sur-Yvette (France); Dillman, Ph. [IRAMAT-CNRS UMR 5060, 33 - Pessac (France); Millard, A. [CEA Saclay, DEN/DM2S/SEMT, Lab. de Mecanique Systemes et Simulation, 91 - Gif-sur-Yvette (France)

    2009-07-01

    Full text of publication follows: The prediction of iron (or low alloy steel) corrosion on very long term period is necessary in two different purposes: (i) the preservation and conservation of cultural heritage and (ii) the French storage and repository concept for the radioactive wastes. In order to determine the evolution of corrosion processes for very long period, mechanistic models have been developed. In these models that are based on a phenomenological approach to evaluate the average corrosion rates, two different environments are considered: concrete (steel reinforcements) and atmospheric. The study of archaeological analogues is a very pertinent tool for the validation of these models. First, physico-chemical analysis on old corrosion layers lead to a precise localisation and identification of the phases present in the corrosion system. Moreover, experimental reinduced corrosions of ancient samples under controlled parameters (temperature, relative humidity) bring new insight on the mechanisms involved. In particular, one crucial question related to the wet-dry cycle is the localisation of oxygen reduction sites in the rust layer. For this purpose, specific experiments have been set up to re-corrode the ancient samples in marked medium (using {sup 18}O{sub 2}). Samples were exposed to cycling between high and low relative humidity, produced by saline saturated solutions. Then cross-sections of samples obtained were investigated by nuclear reaction analysis (NRA) {sup 18}O(p,{alpha}){sup 15}N on the Pierre Sue Laboratory nuclear microprobe. In this presentation the {sup 18}O distribution profiles are discussed and interpreted in order to bring new insight on corrosion mechanisms. A comparative interpretation is made for each medium (concrete and atmosphere)

  7. Long-term measurements of NO3 radical at a semiarid urban site: 2. Seasonal trends and loss mechanisms.

    Science.gov (United States)

    Asaf, David; Tas, Eran; Pedersen, Daniel; Peleg, Mordechai; Luria, Menachem

    2010-08-01

    This study is the first to present long-term measurements of the nitrate radical in an urban location. Extensive nitrate radical measurements were conducted together with ancillary parameters during a continuous two year campaign (2005-2007) in the semiarid location of Jerusalem. The average nighttime NO3 concentration was 27.3+/-43.5 ppt, the highest ever reported, with a seasonal average peak during summer (33.3+/-55.8 pptv) with maximum levels exceeding 800 pptv. Significant diurnal changes in NO3 concentrations were observed, caused by an unusual nighttime increase in ozone concentrations. The NO3 loss processes exhibited strong seasonal variability. Homogeneous gas-phase losses were the main removal processes during summer and spring. The heterogeneous losses of N2O5, averaged over the entire campaign, contributed to less than half of the direct losses even though they dominated the winter seasons and part of the autumn months. Statistical regression analysis showed that NO3 was inversely correlated with relative humidity and positively correlated with temperature and to a lesser extent with NO2 and O3, indicating that the heterogeneous removal processes were also important. The diurnal behavior of NO3 was examined using a one-dimensional chemical transport model. The simulations showed that NO3 trends and concentrations were influenced mainly by changes in ozone and nitrogen oxide levels and that the very high levels of NO3 can be explained by the entrainment of fresh ozone from the upper atmospheric levels. After sunset and in the early morning, the homogeneous processes are the major loss pathways, while the heterogeneous N2O5 removal pathway dominates the intermediate times.

  8. Cyclical Long-term Unemployment, Skill Loss, and Monetary Policy

    OpenAIRE

    2012-01-01

    Movements in long-term unemployment (LTU) exhibit a substantial cyclical component. I develop a business cycle model featuring labor market frictions and skill loss during unemployment to capture various stylized facts about the cyclical behavior of long-term unemployment. I find that the skill loss mechanism helps reproduce negative duration dependence, high persistence in unemployment and output, volatility patterns across macroeconomic variables and the behavior of the incidence of LTU aro...

  9. Long-Term Outcomes of Cognitive-Behavioral Treatments for Posttraumatic Stress Disorder among Female Rape Survivors

    Science.gov (United States)

    Resick, Patricia A.; Williams, Lauren F.; Suvak, Michael K.; Monson, Candice M.; Gradus, Jaimie L.

    2012-01-01

    Objective: We conducted a long-term follow-up (LTFU) assessment of participants from a randomized controlled trial comparing cognitive processing therapy (CPT) with prolonged exposure (PE) for posttraumatic stress disorder (PTSD). Competing hypotheses for positive outcomes (i.e., additional therapy, medication) were examined. Method:…

  10. Modeling generation expansion in the context of a security of supply mechanism based on long-term auctions. Application to the Colombian case

    Energy Technology Data Exchange (ETDEWEB)

    Rodilla, P.; Batlle, C. [Institute for Research in Technology, University Pontificia Comillas, Sta. Cruz de Marcenado 26, 28015 Madrid (Spain); Salazar, J. [Empresas Publicas de Medellin, Carrera 58 No. 42-125 Edificio Inteligente, Medellin (Colombia); Sanchez, J.J. [Secretaria de Estado de Cambio Climatico, Ministerio de Medio Ambiente, Rural y Marino. Plaza San Juan de la Cruz, 28071 Madrid (Spain)

    2011-01-15

    In an attempt to provide electricity generation investors with appropriate economic incentives so as to maintain quality of supply at socially optimal levels, a growing number of electricity market regulators have opted for implementing a security of supply mechanism based on long-term auctions. In this context, the ability to analyze long-term investment dynamics is a key issue not only for market agents, but also for regulators. This paper describes a model developed to serve this purpose. A general system-dynamics-inspired methodology has been designed to be able to simulate these long-term auction mechanisms in the formats presently in place. A full-scale simulation based on the Colombian system was conducted to illustrate model capabilities. (author)

  11. Long-term behavior of the concentration of the minor constituents in the mesosphere – a model study

    Directory of Open Access Journals (Sweden)

    M. Grygalashvyly

    2009-04-01

    of the upper atmosphere. The long-term behavior of water vapor is discussed in particular with respect to its impact on the NLC region.

  12. Long-Term Impact of Community-Based Information, Education and Communication Activities on Food Hygiene and Food Safety Behaviors in Vietnam: A Longitudinal Study

    OpenAIRE

    Kumiko Takanashi; Dao To Quyen; Nguyen Thi Le Hoa; Nguyen Cong Khan; Junko Yasuoka; Masamine Jimba

    2013-01-01

    BACKGROUND: Ingestion of contaminated water or food is a major contributor to childhood diarrhea in developing countries. In Vietnam, the use of community-based information, education and communication (IEC) activities could be a sustainable strategy to improve food hygiene and food safety behaviors. This study thus examined the long-term impact of community-based IEC activities on food hygiene and food safety behaviors. METHODS: In this longitudinal study, we interviewed caregivers of childr...

  13. Effect of composition variations on the long-term wasteform behavior of vitrified domestic waste incineration fly-ash purification residues; Influence des variations de composition des vitrifiats de refiom - residus d'epuration des fumees d'incineration d'ordures menageres - sur leur comportement a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Frugier, P.

    2000-07-01

    The effect of variations in the composition of fly-ash purification residue from incinerated domestic waste on the quality of the containment achieved by vitrification was investigated. Three main factors determine the long-term containment quality: the production of a vitrified wasteform, the occurrence of possible crystallization, and the key parameters of long-term alteration in aqueous media. Each of these aspects is described within a composition range defined by variations in the three major elements. (silicon, calcium and aluminum) and two groups of constituents (alkali metals and toxic elements). The silicon fraction in the fly-ash residue was found to be decisive: it is impossible to obtain a satisfactory vitrified wasteform below a given silicon concentration. Compounds with the lowest silica content also exhibited the greatest tendency to crystallize under the cooling conditions prevailing in industrial processes (the dominant crystallized phase is a melilite that occupies a significant fraction of the material and considerably modifies the alteration mechanisms). The initial alteration rate in pure water and the altered glass thickness measured in a closed system at an advanced stage of the dissolution reaction are both inversely related to the silicon concentration in the glass. Several types of long-term behavior were identified according to the composition range, the process conditions and the vitrified waste disposal scenario. Four distinct 'classes' of vitrified wasteform were defined for direct application in industrial processes. (author)

  14. Long-term evolution of techno-social networks: Statistical regularities, predictability and stability of social behaviors

    CERN Document Server

    Godoy-Lorite, Antonia; Sales-Pardo, Marta

    2016-01-01

    In social networks, individuals constantly drop ties and replace them by new ones in a highly unpredictable fashion. This highly dynamical nature of social ties has important implications for processes such as the spread of information or of epidemics. Several studies have demonstrated the influence of a number of factors on the intricate microscopic process of tie replacement, but the macroscopic long-term effects of such changes remain largely unexplored. Here we investigate whether, despite the inherent randomness at the microscopic level, there are macroscopic statistical regularities in the long-term evolution of social networks. In particular, we analyze the email network of a large organization with over 1,000 individuals throughout four consecutive years. We find that, although the evolution of individual ties is highly unpredictable, the macro-evolution of social communication networks follows well-defined statistical laws, characterized by exponentially decaying log-variations of the weight of socia...

  15. Low-dose penicillin in early life induces long-term changes in murine gut microbiota, brain cytokines and behavior

    Science.gov (United States)

    Leclercq, Sophie; Mian, Firoz M.; Stanisz, Andrew M.; Bindels, Laure B.; Cambier, Emmanuel; Ben-Amram, Hila; Koren, Omry; Forsythe, Paul; Bienenstock, John

    2017-01-01

    There is increasing concern about potential long-term effects of antibiotics on children's health. Epidemiological studies have revealed that early-life antibiotic exposure can increase the risk of developing immune and metabolic diseases, and rodent studies have shown that administration of high doses of antibiotics has long-term effects on brain neurochemistry and behaviour. Here we investigate whether low-dose penicillin in late pregnancy and early postnatal life induces long-term effects in the offspring of mice. We find that penicillin has lasting effects in both sexes on gut microbiota, increases cytokine expression in frontal cortex, modifies blood–brain barrier integrity and alters behaviour. The antibiotic-treated mice exhibit impaired anxiety-like and social behaviours, and display aggression. Concurrent supplementation with Lactobacillus rhamnosus JB-1 prevents some of these alterations. These results warrant further studies on the potential role of early-life antibiotic use in the development of neuropsychiatric disorders, and the possible attenuation of these by beneficial bacteria. PMID:28375200

  16. Mechanical dyssynchrony evaluated by tissue Doppler cross-correlation analysis is associated with long-term survival in patients after cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Williams, Eric S; Khouri, Michel G

    2013-01-01

    Aims Pre-implant assessment of longitudinal mechanical dyssynchrony using cross-correlation analysis (XCA) was tested for association with long-term survival and compared with other tissue Doppler imaging (TDI)-derived indices. Methods and results In 131 patients referred for cardiac resynchroniz...

  17. Rapid and reversible impairments of short- and long-term social recognition memory are caused by acute isolation of adult rats via distinct mechanisms.

    Science.gov (United States)

    Shahar-Gold, Hadar; Gur, Rotem; Wagner, Shlomo

    2013-01-01

    Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM) can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM of male and female rats. Moreover, SRM consolidation into long-term memory was blocked following only one day of social isolation. Both impairments were reversible, but with different time courses. Furthermore, only the impairment in SRM consolidation was reversed by systemic administration of arginine-vasopressin (AVP). In contrast to SRM, object recognition memory was not affected by social isolation. We conclude that acute social isolation rapidly induces reversible changes in the brain neuronal and molecular mechanisms underlying SRM, which hamper its acquisition and completely block its consolidation. These changes occur via distinct, AVP sensitive and insensitive mechanisms. Thus, acute social isolation of rats swiftly causes changes in their brain and interferes with their normal social behavior.

  18. Long-Term Effects of Chronic Buspirone during Adolescence Reduce the Adverse Influences of Neonatal Inflammatory Pain and Stress on Adaptive Behavior in Adult Male Rats.

    Science.gov (United States)

    Butkevich, Irina P; Mikhailenko, Viktor A; Vershinina, Elena A; Aloisi, Anna M; Barr, Gordon A

    2017-01-01

    Neonatal pain and stress induce long-term changes in pain sensitivity and behavior. Previously we found alterations in pain sensitivity in adolescent rats exposed to early-life adverse events. We tested whether these alterations have long-lasting effects and if those effects can be improved by the 5-hydroxytryptamine 1A (5-HT1A) receptor agonist buspirone injected chronically during the adolescent period. This study investigates: (1) effects of inflammatory pain (the injection of formalin into the pad of a hind paw) or stress (short maternal deprivation-isolation, MI), or their combination in 1-2-day-old rats on the adult basal pain, formalin-induced pain, anxiety and depression; (2) effects of adolescent buspirone in adult rats that experienced similar early-life insults. Changes in nociceptive thresholds were evaluated using the hot plate (HP) and formalin tests; levels of anxiety and depression were assessed with the elevated plus maze and forced swim tests respectively. Both neonatal painful and stressful treatments induced long-term alterations in the forced swim test. Other changes in adult behavioral responses were dependent on the type of neonatal treatment. There was a notable lack of long-term effects of the combination of early inflammatory pain and stress of MI on the pain responses, anxiety levels or on the effects of adolescent buspirone. This study provides the first evidence that chronic injection of buspirone in adolescent rats alters antinociceptive and anxiolytic effects limited to adult rats that showed behavioral alterations induced by early-life adverse treatments. These data highlight the role of 5-HT1A receptors in long-term effects of neonatal inflammatory pain and stress of short MI on adaptive behavior and possibility of correction of the pain and psychoemotional behavior that were altered by adverse pain/stress intervention using buspirone during critical adolescent period.

  19. Just in time for late-LTP: A mechanism for the role of PKMzeta in long-term memory.

    Science.gov (United States)

    Vlachos, Andreas; Maggio, Nicola; Jedlicka, Peter

    2008-01-01

    It is a fundamental question in neuroscience how long-term memory formation is regulated at the molecular level. Although widely considered a highly complex process requiring numerous molecular players, it also has been speculated that a single protein could play a pivotal role. This "astonishing hypothesis" has made a significant impact on memory research and has led to a reevaluation of concepts regarding memory formation.1,2.

  20. Cortical and trabecular bone benefits of mechanical loading are maintained long-term in mice independent of ovariectomy

    Science.gov (United States)

    Warden, Stuart J.; Galley, Matthew R.; Hurd, Andrea L.; Richard, Jeffrey S.; George, Lydia A.; Guildenbecher, Elizabeth A.; Barker, Rick G.; Fuchs, Robyn K.

    2014-01-01

    Skeletal loading enhances cortical and trabecular bone properties. How long these benefits last following loading cessation remains an unresolved, clinically-relevant question. This study investigated long-term maintenance of loading-induced cortical and trabecular bone benefits in female C57BL/6 mice and the influence of a surgically-induced menopause on the maintenance. 16-week-old animals had their right tibia extrinsically loaded 3 days/week for 4 weeks using the mouse tibial axial compression loading model. Left tibias were not loaded and served as internal controls. Animals were subsequently detrained (restricted to cage activities) for 0, 4, 8, 26 or 52 weeks, with ovariectomy (OVX) or sham-OVX surgery being performed at 0 weeks detraining. Loading increased midshaft tibia cortical bone mass, size and strength, and proximal tibia bone volume fraction. The cortical bone mass, area and thickness benefits of loading were lost by 26 weeks of detraining due to heightened medullary expansion. However, loading-induced benefits on bone total area and strength were maintained at each detraining time point. Similarly, the benefits of loading on bone volume fraction persisted at all detraining time points. The long-term benefits of loading on both cortical and trabecular bone were not influenced by a surgically-induced menopause as there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone properties at early (4 and 8 weeks) detraining time points and trabecular bone properties at all detraining time points. These cumulative data indicate loading has long-term benefits on cortical bone size and strength (but not mass) and trabecular bone morphology which are not influenced by a surgically-induced menopause. This suggests skeletal loading associated with physical activity may provide long-term benefits by preparing the skeleton to offset both the cortical and trabecular bone changes associated with aging and menopause

  1. The Effects of a Self-Efficacy Intervention on Exercise Behavior of Fitness Club Members in 52 Weeks and Long-Term Relationships of Transtheoretical Model Constructs

    Directory of Open Access Journals (Sweden)

    Jan Middelkamp, Maaike van Rooijen, Peter Wolfhagen, Bert Steenbergen

    2017-06-01

    Full Text Available The transtheoretical model of behavior change (TTM is often used to understand changes in health-related behavior, like exercise. Exercise behavior in fitness clubs is an understudied topic, but preliminary studies showed low frequencies and large numbers of drop-out. An initial 12-week self-efficacy intervention reported significant effects on exercise behavior. The objective of this follow up study is testing effects on exercise behavior over 52 weeks and the long-term relationships of all TTM constructs. In total 122 participants (Mage 42.02 yr.; SD 12.29; 67% females were recruited and randomly assigned to group 1 (control, group 2 (self-set activities and group 3 (self-set goals coaching. All participants were monitored 52-weeks. Measurements at baseline, 4, 8, 12, 26 and 52 weeks, using validated scales for stages of change, self-efficacy, decisional balance and processes of change. Exercise behavior and drop-outs were registered. An ANOVA revealed that group 3 significantly (p < 0.05 differed in exercise sessions from group 1 and 2 during the 12 weeks. A chi-square test indicated significant differences for continuing exercising after the intervention: 7 of group 1; 6 of group 2; 19 of group 3. In total 5 demonstrated regular exercise behavior at 26 weeks, and 3 at 52 weeks. Self-efficacy, decisional balance, and processes of change showed limited long-term changes over the later stages of change. At all measurements, participants reported more pros than cons and used more behavioral than cognitive processes. Exercise behavior of members in fitness clubs demonstrated dramatic developments in 52 weeks. The frequencies of sessions were so low that health effects will be minimal. The integrative character of the TTM appears to be weak; the data indicated limited relationships. More research is needed to understand exercise behavior and define optimal strategies to increase exercise attendance and decrease drop-outs in the long term.

  2. The stability of hydrogen evolution activity and corrosion behavior of NiCu coatings with long-term electrolysis in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Solmaz, Ramazan; Doener, Ali; Kardas, Guelfeza [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330, Balcali, Adana (Turkey)

    2009-03-15

    In this study, NiCu composite coating was electrochemically deposited on a copper electrode (Cu/NiCu) and tested for hydrogen evolution reaction (HER) in 1 M KOH solution for long-term electrolysis with the help of cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. The bulk and surface composition of the coating was determined using atomic absorption spectroscopy (AAS) and energy dispersive X-ray (EDX) analysis. The surface morphology was investigated by scanning electron microscopy (SEM). The effect of electrolysis on the corrosion behavior of the Cu/NiCu electrode was also reported. It was found that the NiCu coating had a compact and porous structure with good time stability. The HER activity of the coating was stable over 120 h electrolysis and the HER mechanism was not modified during the operation. The corrosion tests showed that the corrosion resistance of the Cu/NiCu electrode changed when a cathodic current was applied to the electrolysis system. (author)

  3. Long-term effectiveness and prediction of treatment outcome in cognitive behavioral therapy and sertraline for late-life anxiety disorders.

    Science.gov (United States)

    Schuurmans, Josien; Comijs, Hannie; Emmelkamp, Paul M G; Weijnen, Ingrid J C; van den Hout, Marcel; van Dyck, Richard

    2009-12-01

    Although anxiety disorders are prevalent in older adults, randomized controlled trials of treatment effectiveness for late-life anxiety are scarce and have focused primarily on the effectiveness of psychotherapeutic interventions. However, recent findings suggest that in some cases, pharmacological treatment may be more beneficial for late-life anxiety disorders. As yet, there have been no systematic studies investigating prognostic factors for the outcome of cognitive behavioral therapy (CBT) and pharmacotherapy for late-life anxiety. The objective of the present study was to study long-term treatment outcomes and to explore differential predictors for both short-term and long-term treatment outcomes of sertraline and CBT for late-life anxiety disorders. Participants of a randomized controlled trial (RCT) comparing sertraline and CBT for the treatment of late-life anxiety were contacted one year after completing their treatment, so that predictors for both short-term and long-term treatment outcome could be established. Sertraline showed a greater reduction of symptoms than CBT on anxiety (Hamilton Anxiety Rating Scale; HARS) and worry (Worry Domain Questionnaire) ratings at one-year follow-up. The strongest predictor for short-term CBT outcome was poor perceived health, explaining 40% of the variance in post-treatment residual gain scores on the HARS. The strongest predictor for long-term CBT outcome was neuroticism, explaining 20% of the variance in residual gain scores at one-year follow-up. Analyses revealed no significant predictors for treatment outcome in sertraline participants. Our study suggests that long-term use of sertraline might be more beneficial for late-life anxiety than a 15-week CBT program. Poor perceived health and neuroticism are predictive of less improvement after CBT in anxious older adults. Implications of these findings are discussed.

  4. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes: Monitoring Hair Cortisol and Behaviors.

    Directory of Open Access Journals (Sweden)

    Yumi Yamanashi

    Full Text Available Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC. Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1 and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS, Kyoto University (Study 2. We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals' experiences of aggression and sex may be more important contributors to long-term stress than

  5. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes): Monitoring Hair Cortisol and Behaviors.

    Science.gov (United States)

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Inoue-Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC). Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1) and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS), Kyoto University (Study 2). We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals' experiences of aggression and sex may be more important contributors to long-term stress than relocation alone.

  6. Influence of the Melissa officinalis Leaf Extract on Long-Term Memory in Scopolamine Animal Model with Assessment of Mechanism of Action

    Directory of Open Access Journals (Sweden)

    Marcin Ozarowski

    2016-01-01

    Full Text Available Melissa officinalis (MO, English: lemon balm, Lamiaceae, one of the oldest and still most popular aromatic medicinal plants, is used in phytomedicine for the prevention and treatment of nervous disturbances. The aim of our study was to assess the effect of subchronic (28-fold administration of a 50% ethanol extract of MO leaves (200 mg/kg, p.o. compared with rosmarinic acid (RA, 10 mg/kg, p.o. and huperzine A (HU, 0.5 mg/kg, p.o. on behavioral and cognitive responses in scopolamine-induced rats. The results were linked with acetylcholinesterase (AChE, butyrylcholinesterase (BuChE, and beta-secretase (BACE-1 mRNA levels and AChE and BuChE activities in the hippocampus and frontal cortex of rats. In our study, MO and HU, but not RA, showed an improvement in long-term memory. The results were in line with mRNA levels, since MO produced a decrease of AChE mRNA level by 52% in the cortex and caused a strong significant inhibition of BACE1 mRNA transcription (64% in the frontal cortex; 50% in the hippocampus. However, the extract produced only an insignificant inhibition of AChE activity in the frontal cortex. The mechanisms of MO action are probably more complicated, since its role as a modulator of beta-secretase activity should be taken into consideration.

  7. Influence of the Melissa officinalis Leaf Extract on Long-Term Memory in Scopolamine Animal Model with Assessment of Mechanism of Action

    Science.gov (United States)

    Ozarowski, Marcin; Mikolajczak, Przemyslaw L.; Piasecka, Anna; Kachlicki, Piotr; Kujawski, Radoslaw; Bogacz, Anna; Bartkowiak-Wieczorek, Joanna; Szulc, Michal; Kaminska, Ewa; Kujawska, Malgorzata; Jodynis-Liebert, Jadwiga; Gryszczynska, Agnieszka; Opala, Bogna; Lowicki, Zdzislaw; Seremak-Mrozikiewicz, Agnieszka; Czerny, Boguslaw

    2016-01-01

    Melissa officinalis (MO, English: lemon balm, Lamiaceae), one of the oldest and still most popular aromatic medicinal plants, is used in phytomedicine for the prevention and treatment of nervous disturbances. The aim of our study was to assess the effect of subchronic (28-fold) administration of a 50% ethanol extract of MO leaves (200 mg/kg, p.o.) compared with rosmarinic acid (RA, 10 mg/kg, p.o.) and huperzine A (HU, 0.5 mg/kg, p.o.) on behavioral and cognitive responses in scopolamine-induced rats. The results were linked with acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and beta-secretase (BACE-1) mRNA levels and AChE and BuChE activities in the hippocampus and frontal cortex of rats. In our study, MO and HU, but not RA, showed an improvement in long-term memory. The results were in line with mRNA levels, since MO produced a decrease of AChE mRNA level by 52% in the cortex and caused a strong significant inhibition of BACE1 mRNA transcription (64% in the frontal cortex; 50% in the hippocampus). However, the extract produced only an insignificant inhibition of AChE activity in the frontal cortex. The mechanisms of MO action are probably more complicated, since its role as a modulator of beta-secretase activity should be taken into consideration. PMID:27239217

  8. Long-term collections

    CERN Multimedia

    Collectes à long terme

    2007-01-01

    The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.

  9. Thermally Activated Deformation Behavior of ufg-Au: Environmental Issues During Long-Term and High-Temperature Nanoindentation Testing

    Science.gov (United States)

    Maier, Verena; Leitner, Alexander; Pippan, Reinhard; Kiener, Daniel

    2015-12-01

    For testing time-dependent material properties by nanoindentation, in particular for long-term creep or relaxation experiments, thermal drift influences on the displacement signal are of prime concern. To address this at room and elevated temperatures, we tested fused quartz at various contact depths at room temperature and ultra-fine grained (ufg) Au at various temperatures. We found that the raw data for fused quartz are strongly affected by thermal drift, but corrected by use of dynamic stiffness measurements all the datasets collapse. The situation for the ufg Au shows again that the data are only useful with drift correction, but with this applied it turns out that there is a significant change of elastic and plastic properties when exceeding 200°C, which is also reflected by an increasing strain rate sensitivity.

  10. Staff Member Reactions to Same-Gender, Resident-to-Resident Sexual Behavior Within Long-Term Care Facilities.

    Science.gov (United States)

    Ahrendt, Andrew; Sprankle, Eric; Kuka, Alex; McPherson, Keagan

    2017-01-01

    The current study assesses ageism and heterosexism relating to older adult sexual activity within long-term care facilities. To assess caregiver reactions, 153 residential care facility staff members read one of three vignettes. Each vignette described a scenario in which a staff member walks in on two residents (male/female, male/male, or female/female) engaging in sexual activity. Although no main effects were discovered for vignette type, exploratory analyses revealed that the facility where participants were employed was significantly related to their ratings of approval. Furthermore, an interaction effect between vignette and facility types was also discovered for caregivers' approval of sexual activity among residents. Additionally, a strong overall approval rating of older adult sexuality was reported by staff members. The results of this study warrant that further research is necessary regarding older adults' perception of caregiver bias, as well as further investigation of caregivers' perceptions of older adults' sexual activity.

  11. Long-term postpartum anxiety and depression-like behavior in mother rats subjected to maternal separation are ameliorated by palatable high fat diet.

    Science.gov (United States)

    Maniam, Jayanthi; Morris, Margaret J

    2010-03-17

    While the effects of maternal separation on pups are well studied, the impact on dams has attracted little attention. The consumption of palatable food is known to dampen stress responses in animals, and emotions influence food choice in humans. Here we examined the early- and long-term impacts of maternal separation on behavioral profile of the dams, and the effects of palatable cafeteria high-fat diet (HFD). After littering, Sprague-Dawley female rats were subjected to prolonged separation, S180 (180 min) or brief separation, S15 (15 min/day) from postnatal days (PND) 2-14. At 4 weeks postpartum, half the dams were assigned to HFD. Anxiety and depression-like behaviors were assessed pre- and post-diet. Compared to S15 dams, S180 dams consuming chow demonstrated increased anxiety and depression-like behaviors assessed by elevated plus maze (EPM) and forced swim (FST) tests, respectively. These behavioral deficits were observed at 4 weeks, and persisted until 17 weeks postpartum. The S180 dams also had increased plasma corticosterone concentration compared to S15 dams, which coincided with increased hypothalamic CRH mRNA and reduced hippocampal GR mRNA expression, suggesting possible dysregulation of hypothalamic-pituitary-adrenal axis activity. Interestingly, continuous provision of HFD improved the behavioral deficits observed in S180 dams with significant reduction of hypothalamic CRH mRNA expression. These data are the first to describe long-term detrimental behavioral impacts of separation in dams, suggesting this may provide a model of postpartum depression. Moreover, they support the notion of long-term beneficial effects of 'comfort food' on stress responses.

  12. Social phobia: individual response patterns and the long-term effects of behavioral and cognitive interventions. A follow-up study.

    Science.gov (United States)

    Mersch, P P; Emmelkamp, P M; Lips, C

    1991-01-01

    In this study the long-term effectiveness of Social Skills Training (SST) and Rational Emotive Therapy (RET), on social phobia was studied, as well as the differential influence of patient characteristics on treatment effectiveness. Fifty-seven patients were assessed 14 months after the post-test. Results showed that long-term effectiveness was independent of the response-pattern of the patients. Comparisons between methods, irrespective of the response-pattern of the patients, showed no differences in effectiveness in favor of either SST or RET. Explorative analysis indicated the potential predictive power for treatment-outcome of confederate ratings of overt behavior on the SSIT. Patients who needed additional treatment appeared to perform significantly worse on this measure at the pretest. No factors could be traced that predict relapse after a relatively successful treatment.

  13. Physical activity, sedentary behavior, and long-term cardiovascular risk in young people:A review and discussion of methodology in prospective studies

    Institute of Scientific and Technical Information of China (English)

    Jakob Tarp; Jan Christian Brønd; Lars Bo Andersen; Niels Christian Møller; Karsten Froberg; Anders Grøntved

    2016-01-01

    The long-term effects of physical activity (PA) or sedentary behavior on cardiovascular health in young people are not well understood. In this study, we use a narrative format to review the evidence for a prospective association with adiposity and other well-established biological cardiovascular risk factors in healthy young people, considering only studies with at least 2 years of follow-up. PA appears to elicit a long-term beneficial effect on adiposity and particularly markers of cardiovascular health. With adiposity, however, a few studies also reported that higher levels of PA were associated with higher levels of adiposity. Time spent sedentary does not appear to be related to adiposity or markers of cardiovascular health independent of PA. We then discuss the uncertainties in the underlying causal chain and consider a number of alternative modeling strategies, which could improve our understanding of the relationship in future studies. Finally, we consider the current methodology for assessing PA and sedentary time.

  14. Long-term corrosion behavior of ODS-Eurofer in flowing Pb-15.7Li at 550°C

    Directory of Open Access Journals (Sweden)

    W. Krauss

    2016-12-01

    In this paper results from long-term corrosion testing of ODS-Eurofer will be reported for exposure times up to 1.5 years at a flow velocity of 0.1m/s. The evaluated data for ODS-Eurofer corrosion will be compared with values of ‘single’ phase ’classical‘ Eurofer. The observed corrosion attack and mechanisms will be discussed in detail considering the testing conditions and the microstructure of the RAFM-steels.

  15. Long-term effects of early adolescent methamphetamine exposure on depression-like behavior and the hypothalamic vasopressin system in mice.

    Science.gov (United States)

    Joca, Lauren; Zuloaga, Damian G; Raber, Jacob; Siegel, Jessica A

    2014-01-01

    Methamphetamine (MA) has neurotoxic effects on the adult human brain that can lead to deficits in behavior and cognition. However, relatively little research has examined the behavioral or neurotoxic effects of MA in adolescents. The rising rates of adolescent MA use make it imperative that we understand the long-term effects of MA exposure on the adolescent brain and how these effects may differ from those seen in adults. In this study, the long-term effects of MA exposure during early adolescence on behavior and the vasopressin system in the paraventricular nucleus of the hypothalamus in late adolescent and adult male and female C57BL/6J mice were examined. MA exposure increased depression-like behavior in the Porsolt forced swim test in both late adolescent and adult male and female mice. Late adolescent male mice exposed to MA also showed a decrease in the number of vasopressin-immunoreactive neurons in the paraventricular nucleus compared to sex-matched saline-treated controls. Thus, similar to humans exposed to MA during adolescence, mice exposed to MA during adolescence show increased depression-like behavior later in life. These changes in behavior may be related to MA-induced alterations in vasopressin and the hypothalamic-pituitary-adrenal axis, especially in males.

  16. Remarks on the possible universal mechanism of the non-linear long-term autocorrelations in financial time-series

    Science.gov (United States)

    Kutner, Ryszard; Świtała, Filip

    2004-12-01

    The paper consists of two parts: (i) the empirical one where the non-linear, long-term autocorrelations present in high-frequency data extracting from the Warsaw Stock Exchange were analyzed and (ii) theoretical one where predictions of our model (Quantitative Finance 3 (2003) 201; Physica A (2003); Chem. Phys. 284 (2002) 481; Phys. Comm. 147 (2002) 565; Physica A 264 (1999) 84; Physica A 264 (1999) 107; Lecture Notes in Computer Science 2657 (2003) 407; Eur. Phys. J. B 33 (2003) 495) were shown and discussed. This model introduces the possibility that the Weierstrass (hierarchical) random walk can be occasionally intermitted by momentary localizations; the localizations themselves are again described by the Weierstrass process. In other words, this combined walk is a kind of the non-separable, generalized continuous-time random walk formalism. To adapt the model to the description of empirical data recorded at time horizon Δt=1 min, we applied a discretization procedure into the continuous-time series produced by the model. We observed that such a procedure generates the non-linear, long-term autocorrelations even in the Gaussian regime, as turning points of the random walk trajectory are, most often, incommensurable with discretization time-step. These autocorrelations appear to be similar to those observed in the financial time series (Physica A 287 (2000) 396; Physica A 299 (2001) 1; Physica A 299 (2001) 16; Physica A 299 (2001) 28), although single steps of the walker within continuous time are, by definition, uncorrelated. Our approach suggests a surprising origin of the non-linear, long-term autocorrelations alternative to the one proposed very recently (cf. Phys. Rev. E 67 (2003) 021112 and refs. therein) although both approaches involve related variants of the well-known CTRW formalism applied in yet many different branches of knowledge (Phys. Rep. 158 (1987) 263; Phys. Rep. 195 (1990) 127; in: A. Bunde, S. Havlin (Eds.), Fractals in Science, Springer

  17. The middle Pleistocene transition: characteristics, mechanisms, and implications for long-term changes in atmospheric pCO 2

    Science.gov (United States)

    Clark, Peter U.; Archer, David; Pollard, David; Blum, Joel D.; Rial, Jose A.; Brovkin, Victor; Mix, Alan C.; Pisias, Nicklas G.; Roy, Martin

    2006-12-01

    The emergence of low-frequency, high-amplitude, quasi-periodic (˜100-kyr) glacial variability during the middle Pleistocene in the absence of any significant change in orbital forcing indicates a fundamental change internal to the climate system. This middle Pleistocene transition (MPT) began 1250 ka and was complete by 700 ka. Its onset was accompanied by decreases in sea surface temperatures (SSTs) in the North Atlantic and tropical-ocean upwelling regions and by an increase in African and Asian aridity and monsoonal intensity. During the MPT, long-term average ice volume gradually increased by ˜50 m sea-level equivalent, whereas low-frequency ice-volume variability experienced a 100-kyr lull centered on 1000 ka followed by its reappearance ˜900 ka, although as a broad band of power rather than a narrow, persistent 100-kyr cycle. Additional changes at 900 ka indicate this to be an important time during the MPT, beginning with an 80-kyr event of extreme SST cooling followed by the partial recovery and subsequent stabilization of long-term North Atlantic and tropical ocean SSTs, increasing Southern Ocean SST variability primarily associated with warmer interglacials, the loss of permanent subpolar sea-ice cover, and the emergence of low-frequency variability in Pacific SSTs and global deep-ocean circulation. Since 900 ka, ice sheets have been the only component of the climate system to exhibit consistent low-frequency variability. With the exception of a near-universal organization of low-frequency power associated with marine isotope stages 11 and 12, all other components show an inconsistent distribution of power in frequency-time space, suggesting a highly nonlinear system response to orbital and ice-sheet forcing. Most hypotheses for the origin of the MPT invoke a response to a long-term cooling, possibly induced by decreasing atmospheric pCO 2. None of these hypotheses, however, accounts for the geological constraint that the earliest Northern Hemisphere

  18. Long-term Behaviors of Two Versions of FGOALS2 in Preindustrial Control Simulations with Implications for 20th Century Simulations

    Institute of Scientific and Technical Information of China (English)

    LIN Pengfei; LIU Hailong; YU Yongqiang; ZHOU Tianjun

    2013-01-01

    Climate drift in preindustrial control (PICTL) simulations can lead to spurious climate trends and large uncertainties in historical and future climate simulations in coupled models.This study examined the longterm behaviors and stabilities of the PICTL simulations in the two versions of FGOALS2 (the Flexible Global Ocean-Atmosphere-Land System model Version 2),which have been submitted to the Coupled Model Intercomparison Project Phase 5 (CMIP5).As verified by examining time series of thermal fields and their linear trends,the PICTL simulations showed stable long-term integration behaviors and no obvious climate drift [the magnitudes of linear trends of SST were both less than 0.04℃ (100 yr)-1] over multiple centuries.The changed SSTs in a century (that corresponded to the linear trends) were less than the standard deviations of annual mean values,which implied the internal variability was not affected.These trend values were less than 10% of those of global averaged SST from observations and historical runs during the periods of slow and rapid warming.Such stable long-term integration behaviors reduced the uncertainty of the estimation of global warming rates in the historical and future climate projections in the two versions of FGOALS2.Compared with the trends in the Northern Hemisphere,larger trends existed in the SST and sea ice extents at the middle to high latitudes of the Southern Hemisphere (SH).To estimate the historical and future climate trends in the SH or at some specific regions in FGOALS2,corrections needed to be carried out.The similar long-term behaviors in the two versions of FGOALS2 may be attributed to proper physical processes in the ocean model.

  19. A numerical investigation into the long-term behaviors of Fukushima-derived137Cs in the ocean

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chang; WANG Gang; QIAO Fangli; WANG Guansuo; JUNG Kyung-Tae; XIA Changshui

    2015-01-01

    The Fukushima nuclear accident in 2011 released large amounts of radionuclides, including137Cs, into the Pacific Ocean. A quasi-global ocean radioactive transport model with horizontal grid spacing of 0.5°×0.5° and 21 vertical layers was thereafter established to study the long-term transport of the Fukushima-derived137Cs in the ocean. The simulation shows that the plume of137Cs would be rapidly transported eastward alongside the Kuroshio Current and its extensions. Contaminated waters with concentrations lower than 2 Bq/m3 would reach the west coast of North America 4 or 5 years after the accident. The137Cs tends to be carried, despite its very low concentration, into the Indian and South Pacific Oceans by 2016 via various branches of ocean currents. Meanwhile, the137Cs concentrations in the western part of the North Pacific Ocean decrease rapidly with time. Up to now the highly contaminated waters have remained in the upper 400 m, showing no evidence of significant penetration to deeper layers.

  20. Long-term habituation (LTH in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory

    Directory of Open Access Journals (Sweden)

    H. Maldonado

    1997-07-01

    Full Text Available A decade of studies on long-term habituation (LTH in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP (³15 trials, intertrial interval (ITI of 171 s invariably yielded LTH, while a weak training protocol (WTP (£10 trials, ITI = 171 s invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining. The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

  1. Evaluation of long-term behavior of concretes in high level waste repositories. An accelerated leaching test

    Directory of Open Access Journals (Sweden)

    Hidalgo, A.

    2004-04-01

    Full Text Available The present work describes an accelerated leaching method that with a rapid process allows to develop and evaluate cements for use in a nuclear disposal, and the understanding of the long term effects. The method has been developed to study the stability of cementitious materials in contact with bentonite, to be used in high level radioactivity waste repositories. Nitric acid has been selected to simulate in an accelerated way the pH decreasing produced when concrete is in contact with groundwaters.

    El presente trabajo describe un ensayo acelerado de lixiviación, que mediante un proceso rápido, permite desarrollar y evaluar cementos para su uso en instalaciones nucleares, y la comprensión de su comportamiento a largo plazo. El método se ha desarrollado para estudiar la estabilidad de materiales de base cemento, en contacto con bentonita, que serán utilizados en almacenamientos de resíduos radiactivos de alta actividad. Como agente lixiviante se seleccionó el ácido nítrico, con objeto de simular de forma acelerada, la disminución del pH que se produce cuando el hormigón entra en contacto con aguas subterráneas.

  2. Long-term outcome of cognitive functions, emotional behavior, and quality of life in a family with familial hemiplegic migraine.

    Science.gov (United States)

    Karner, Elfriede; Nachbauer, Wolfgang; Bodner, Thomas; Benke, Thomas; Boesch, Sylvia; Delazer, Margarete

    2012-06-01

    To investigate long-term cognitive outcome, mood, and quality of life in a family with genetically proven familial hemiplegic migraine (FHM). FHM is a rare autosomal-dominant subtype of migraine with aura, characterized by some degree of hemiparesis during the aura. In a previous study, we showed preserved and impaired cognitive functions in patients with FHM. Until now, the progression of cognitive dysfunctions has not been known. However, the ability to predict progression is important for counseling patients about education, career, and family life. Seven years after extensive baseline neuropsychological testing, we retested 6 members of a family with FHM, including questionnaires about mood and quality of life. The follow-up assessment revealed no global cognitive decline. All the patients' linguistic abilities and verbal memory remained intact; however, their figural memory, attention, and some aspects of executive function were impaired. Half the patients had a slight deterioration in their visuoconstructional functions. Half had higher scores on the trait and state anxiety measures. Cognitive deficits in a family with FHM persisted, but without marked progression. Worsening of visuoconstructional abilities may be related to executive dysfunction, confirming a disturbance of cerebrocerebellar circuits.

  3. System biology analysis of long-term effect and mechanism of Bufei Yishen on COPD revealed by system pharmacology and 3-omics profiling

    Science.gov (United States)

    Li, Jiansheng; Zhao, Peng; Yang, Liping; Li, Ya; Tian, Yange; Li, Suyun

    2016-01-01

    System pharmacology identified 195 potential targets of Bufei Yishen formula (BYF), and BYF was proven to have a short-term therapeutic effect on chronic obstructive pulmonary disease (COPD) rats previously. However, the long-term effect and mechanism of BYF on COPD is still unclear. Herein, we explored its long-term effect and underlying mechanism at system level. We administered BYF to COPD rats from week 9 to 20, and found that BYF could prevent COPD by inhibiting the inflammatory cytokines expression, protease-antiprotease imbalance and collagen deposition on week 32. Then, using transcriptomics, proteomics and metabolomics analysis, we identified significant regulated genes, proteins and metabolites in lung tissues of COPD and BYF-treated rats, which could be mainly attributed to oxidoreductase-antioxidant activity, focal adhesion, tight junction or lipid metabolism. Finally, based on the comprehensive analysis of system pharmacology target, transcript, protein and metabolite data sets, we found a number of genes, proteins, metabolites regulated in BYF-treated rats and the target proteins of BYF were involved in lipid metabolism, inflammatory response, oxidative stress and focal adhension. In conclusion, BYF exerts long-term therapeutic action on COPD probably through modulating the lipid metabolism, oxidative stress, cell junction and inflammatory response pathways at system level. PMID:27146975

  4. Spectral kinetic modeling and long-term behavior assessment of Arthrospira platensis growth in photobioreactor under red (620 nm) light illumination.

    Science.gov (United States)

    Farges, Bérangère; Laroche, Céline; Cornet, Jean-François; Dussap, Claude-Gilles

    2009-01-01

    The ability to cultivate the cyanobacterium Arhtrospira platensis in artificially lightened photobioreactors using high energetic efficiency (quasi-monochromatic) red LED was investigated. To reach the same maximal productivities as with the polychromatic lightening control conditions (red + blue, P/2e(-) = 1.275), the need to work with an optimal range of wavelength around 620 nm was first established on batch and continuous cultures. The long-term physiological and kinetic behavior was then verified in a continuous photobioreactor illuminated only with red (620 nm) LED, showing that the maximum productivities can be maintained over 30 residence times with only minor changes in the pigment content of the cells corresponding to a well-known adaptation mechanism of the photosystems, but without any effect on growth and stoichiometry. For both poly and monochromatic incident light inputs, a predictive spectral knowledge model was proposed and validated for the first time, allowing the calculation of the kinetics and stoichiometry observed in any photobioreactor cultivating A. platensis, or other cyanobacteria if the parameters were updated. It is shown that the photon flux (with a specified wavelength) must be used instead of light energy flux as a relevant control variable for the growth. The experimental and theoretical results obtained in this study demonstrate that it is possible to save the energy consumed by the lightening device of photobioreactors using red LED, the spectral range of which is defined according to the action spectrum of photosynthesis. This appears to be crucial information for applications in which the energy must be rationalized, as it is the case for life support systems in closed environments like a permanent spatial base or a submarine.

  5. Automated analysis of long-term bridge behavior and health using a cyber-enabled wireless monitoring system

    Science.gov (United States)

    O'Connor, Sean M.; Zhang, Yilan; Lynch, Jerome; Ettouney, Mohammed; van der Linden, Gwen

    2014-04-01

    A worthy goal for the structural health monitoring field is the creation of a scalable monitoring system architecture that abstracts many of the system details (e.g., sensors, data) from the structure owner with the aim of providing "actionable" information that aids in their decision making process. While a broad array of sensor technologies have emerged, the ability for sensing systems to generate large amounts of data have far outpaced advances in data management and processing. To reverse this trend, this study explores the creation of a cyber-enabled wireless SHM system for highway bridges. The system is designed from the top down by considering the damage mechanisms of concern to bridge owners and then tailoring the sensing and decision support system around those concerns. The enabling element of the proposed system is a powerful data repository system termed SenStore. SenStore is designed to combine sensor data with bridge meta-data (e.g., geometric configuration, material properties, maintenance history, sensor locations, sensor types, inspection history). A wireless sensor network deployed to a bridge autonomously streams its measurement data to SenStore via a 3G cellular connection for storage. SenStore securely exposes the bridge meta- and sensor data to software clients that can process the data to extract information relevant to the decision making process of the bridge owner. To validate the proposed cyber-enable SHM system, the system is implemented on the Telegraph Road Bridge (Monroe, MI). The Telegraph Road Bridge is a traditional steel girder-concrete deck composite bridge located along a heavily travelled corridor in the Detroit metropolitan area. A permanent wireless sensor network has been installed to measure bridge accelerations, strains and temperatures. System identification and damage detection algorithms are created to automatically mine bridge response data stored in SenStore over an 18-month period. Tools like Gaussian Process (GP

  6. Solar irradiance at the Earth's surface: long-term behavior observed at the South Pole

    Directory of Open Access Journals (Sweden)

    J. E. Frederick

    2010-11-01

    Full Text Available This research examines a 17-year database of UV-A (320–400 nm and visible (400–600 nm solar irradiance obtained by a scanning spectroradiometer located at the South Pole. The goal is to define the variability in solar irradiance reaching the polar surface, with emphasis on the influence of cloudiness and on identifying systematic trends and possible links to the solar cycle. To eliminate changes associated with the varying solar elevation, the analysis focuses on data averaged over 30–35 day periods centered on each year's austral summer solstice. The long-term average effect of South Polar clouds is a small attenuation, with the mean measured irradiances being about 5–6% less than the clear-sky values, although at any specific time clouds may reduce or enhance the signal that reaches the sensor. The instantaneous fractional attenuation or enhancement is wavelength dependent, where the percent deviation from the clear-sky irradiance at 400–600 nm is typically 2.5 times that at 320–340 nm. When averaged over the period near each year's summer solstice, significant correlations appear between irradiances at all wavelengths and the solar cycle as measured by the 10.7 cm solar radio flux. An approximate 1.8 ± 1.0% decrease in ground-level irradiance occurs from solar maximum to solar minimum for the wavelength band 320–400 nm. The corresponding decrease for 400–600 nm is 2.4 ± 1.9%. The best-estimate declines appear too large to originate in the sun. If the correlations have a geophysical origin, they suggest a small variation in atmospheric attenuation with the solar cycle over the period of observation, with the greatest attenuation occurring at solar minimum.

  7. Post-ischaemic long-term synaptic potentiation in the striatum: a putative mechanism for cell type-specific vulnerability.

    Science.gov (United States)

    Calabresi, Paolo; Saulle, Emilia; Centonze, Diego; Pisani, Antonio; Marfia, Girolama A; Bernardi, Giorgio

    2002-04-01

    In the present in vitro study of rat brain, we report that transient oxygen and glucose deprivation (in vitro ischaemia) induced a post-ischaemic long-term synaptic potentiation (i-LTP) at corticostriatal synapses. We compared the physiological and pharmacological characteristics of this pathological form of synaptic plasticity with those of LTP induced by tetanic stimulation of corticostriatal fibres (t-LTP), which is thought to represent a cellular substrate of learning and memory. Activation of N-methyl-D-aspartate (NMDA) receptors was required for the induction of both forms of synaptic plasticity. The intraneuronal injection of the calcium chelator BAPTA [bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate] and inhibitors of the mitogen-activated protein kinase pathway blocked both forms of synaptic plasticity. However, while t-LTP showed input specificity, i-LTP occurred also at synaptic pathways inactive during the ischaemic period. In addition, scopolamine, a muscarinic receptor antagonist, prevented the induction of t-LTP but not of i-LTP, indicating that endogenous acetylcholine is required for physiological but not for pathological synaptic potentiation. Finally, we found that striatal cholinergic interneurones, which are resistant to in vivo ischaemia, do not express i-LTP while they express t-LTP. We suggest that i-LTP represents a pathological form of synaptic plasticity that may account for the cell type-specific vulnerability observed in striatal spiny neurones following ischaemia and energy deprivation.

  8. Long-term eclipse timing of white dwarf binaries: an observational hint of a magnetic mechanism at work

    CERN Document Server

    Bours, M C P; Parsons, S G; Dhillon, V S; Ashley, R P; Bento, J P; Breedt, E; Butterley, T; Caceres, C; Copperwheat, C M; Hardy, L K; Hermes, J J; Irawati, P; Kerry, P; Kilkenny, D; Littlefair, S P; McAllister, M J; Rattanasoon, S; Sahman, D I; Vuckovic, M; Wilson, R W

    2016-01-01

    We present a long-term programme for timing the eclipses of white dwarfs in close binaries to measure apparent and/or real variations in their orbital periods. Our programme includes 67 close binaries, both detached and semi-detached and with M-dwarfs, K-dwarfs, brown dwarfs or white dwarfs secondaries. In total, we have observed more than 650 white dwarf eclipses. We use this sample to search for orbital period variations and aim to identify the underlying cause of these variations. We find that the probability of observing orbital period variations increases significantly with the observational baseline. In particular, all binaries with baselines exceeding 10 yrs, with secondaries of spectral type K2 -- M5.5, show variations in the eclipse arrival times that in most cases amount to several minutes. In addition, among those with baselines shorter than 10 yrs, binaries with late spectral type (>M6), brown dwarf or white dwarf secondaries appear to show no orbital period variations. This is in agreement with t...

  9. Comparison of long-term effects of cognitive-behavioral therapy versus mindfulness-based therapy on reduction of symptoms among patients suffering from irritable bowel syndrome

    OpenAIRE

    Zomorodi, Saeedeh; Abdi, Saeed; Tabatabaee, Seyed Kazem Rasulzadeh

    2014-01-01

    Aim The aim of this study was to compare the long-term effects of cognitive-behavioral treatment and mindfulness-based treatment on decreasing symptoms of patients suffering from irritable bowel syndrome (IBS). Background One of the most modern therapies put forward in therapy of IBS is mindfulness-based metacognitive therapy. Patients and methods In this quasi-experimental study, 36 people with mean age of 32 years old, including 24 patients with IBS and 12 healthy normal subjects as control...

  10. Provision or Good Genes? Menstrual Cycle Shifts in Women's Preferences for Short-Term and Long-Term Mates' Altruistic Behavior

    Directory of Open Access Journals (Sweden)

    Ryo Oda

    2014-04-01

    Full Text Available Men's altruism may have evolved, via female choice, as a signal of either their genetic quality or their willingness to allocate resources to offspring. The possibility that men display altruism to signal their genetic quality may be tested by examining women's preference for men's altruism across the stages of the menstrual cycle. Because women can maximize reproductive benefits by mating with men who have “good genes” on high-fertility versus low-fertility days, women should show a heightened preference for male altruism on high-fertility days compared to low-fertility days, and this heightened preference should be more apparent when women evaluate men for short-term sexual relationships than for long-term committed relationships. The possibility that men display altruism to signal their willingness to provision, as opposed to their genetic quality, may be tested by examining women's preference for men's altruism toward different recipients. More specifically, altruistic behavior toward family members may reflect a willingness to provide resources for kin and, hence, willingness to provision, whereas altruistic behavior toward strangers may function as an honest signal of genetic quality. In two samples of young women (TVs = 131 and 481, we found no differences between high- and low-fertility participants in preference for men's altruism, and women preferred men's altruism more in long-term than short-term relationships. The findings suggest that men's altruistic behavior functions as a signal of willingness to provide resources rather than genetic quality.

  11. Arterial blood gas derangement and level of comorbidity are not predictors of long-term mortality of COPD patients treated with mechanical ventilation.

    Science.gov (United States)

    Christensen, S; Rasmussen, L; Horváth-Puhó, E; Lenler-Petersen, P; Rhode, M; Johnsen, S P

    2008-07-01

    Limited and inconsistent data exist on simple, readily available predictors of long-term mortality of critically ill chronic obstructive pulmonary disease patients requiring invasive mechanical ventilation. We therefore examined the influence of arterial blood gas derangement and burden of comorbidities on 90-day and 1-yr mortality of chronic obstructive pulmonary disease patients treated with invasive mechanical ventilation. We identified all chronic obstructive pulmonary disease patients (n = 230) treated with invasive mechanical ventilation between 1994 and 2004 at a Danish primary-level hospital. Data on arterial blood gas specimens and comorbidity were obtained from medical records and Hospital Discharge Registries. We used Cox's regression analysis to estimate mortality ratios according to arterial blood gas values and level of comorbidity. Ninety-day and 1-yr mortality among chronic obstructive pulmonary disease patients requiring invasive mechanical ventilation was 30.8% and 40.5%, respectively. All 90-day and 1-yr mortality ratios according to arterial blood gas values were close to one and one was included in all 95% CI. Among patients with a high level of comorbidity 90-day mortality ratio was 1.3 (95% CI: 0.6-2.7) when compared with patients without comorbidity. The corresponding 1-yr mortality ratio was 1.4 (95% CI: 0.7-2.9). Chronic obstructive pulmonary disease patients treated with invasive mechanical ventilation have substantial long-term mortality. Neither the levels of arterial blood gas values measured immediately before invasive mechanical ventilation was initiated nor the burden of comorbidity were strong determinants of long-term mortality among these patients.

  12. Short- and Long-Term Biomarkers for Bacterial Robustness: A Framework for Quantifying Correlations between Cellular Indicators and Adaptive Behavior

    NARCIS (Netherlands)

    Besten, den H.M.W.; Arvind, A.; Gaballo, H.M.S.; Moezelaar, R.; Zwietering, M.H.; Abee, T.

    2010-01-01

    The ability of microorganisms to adapt to changing environments challenges the prediction of their history-dependent behavior. Cellular biomarkers that are quantitatively correlated to stress adaptive behavior will facilitate our ability to predict the impact of these adaptive traits. Here, we prese

  13. Long-term follow-up of home-based behavioral management training provided by migraine patients

    NARCIS (Netherlands)

    Voerman, J.S.; de Klerk, C.; Mérelle, S.Y.M.; Aartsen, E.; Timman, R.; Sorbi, M.J.; Passchier, J.

    2014-01-01

    Background Behavioral migraine approaches are effective in reducing headache attacks. Availability of treatment might be increased by using migraine patients as trainers. Therefore, Mérelle and colleagues developed and evaluated a home-based behavioral management training (BMT) by lay trainers (1).

  14. Long-Term Evaluation of Abnormal Behavior in Adult Ex-laboratory Chimpanzees (Pan troglodytes Following Re-socialization

    Directory of Open Access Journals (Sweden)

    Karl Crailsheim

    2013-01-01

    Full Text Available Adverse rearing conditions are considered a major factor in the development of abnormal behavior. We investigated the overall levels, the prevalence and the diversity of abnormal behavior of 18 adult former laboratory chimpanzees, who spent about 20 years single caged, over a two-year period following re-socialization. According to the onset of deprivation, the individuals were classified as early deprived (EDs, mean: 1.2 years or late deprived (LDs, mean: 3.6 years. The results are based on 187.5 hours of scan sampling distributed over three sample periods: subsequent to re-socialization and during the first and second year of group-living. While the overall levels and the diversity of abnormal behavior remained stable over time in this study population, the amplifying effects of age at onset of deprivation became apparent as the overall levels of abnormal behavior of EDs were far above those of LDs in the first and second year of group-living, but not immediately after re-socialization. The most prevalent abnormal behaviors, including eating disorders and self-directed behaviors, however, varied in their occurrence within subjects across the periods. Most important, the significance of social companionship became obvious as the most severe forms of abnormal behavior, such as dissociative and self-injurious behaviors declined.

  15. Long-Term Collections

    CERN Multimedia

    Comité des collectes à long terme

    2011-01-01

    It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.

  16. Surface Engineering of Polycrystalline Silicon for Long-term Mechanical Stress Endurance Enhancement in Flexible Low Temperature Poly-Si Thin-Film Transistors.

    Science.gov (United States)

    Chen, Bo-Wei; Chang, Ting-Chang; Hung, Yu-Ju; Huang, Shin-Ping; Chen, Hua-Mao; Liao, Po-Yung; Lin, Yu-Ho; Huang, Hui-Chun; Chiang, Hsiao-Cheng; Yang, Chung-I; Zheng, Yu-Zhe; Chu, Ann-Kuo; Li, Hung-Wei; Tsai, Chih-Hung; Lu, Hsueh-Hsing; Wang, Terry Tai-Jui; Chang, Tsu-Chiang

    2017-02-08

    Surface morphology in polycrystalline silicon (poly-Si) film is an issue regardless of whether conventional excimer laser annealing (ELA) or the newer metal-induced lateral crystallization (MILC) process is used. This paper investigates the stress distribution while undergoing long-term mechanical stress and the influence of stress on electrical characteristics. Our simulated results show that the non-uniform stress in the gate insulator is more pronounced near the polysilicon/gate insulator edge and at the two sides of the polysilicon protrusion. This stress results in defects in the gate insulator and leads to a non-uniform degradation phenomenon, which affects both the performance and reliability in thin-film transistors (TFTs). The degree of degradation is similar regardless of bending axis (channel-length axis, channel-width axis) or bending type (compression, tension), which means that the degradation is dominated by the protrusion effects. Furthermore, by utilizing long-term electrical bias stresses after undergoing long-tern bending stress, it is apparent that the carrier injection is severe in the sub-channel region, which confirms that the influence of protrusions is crucial. To eliminate the influence of surface morphology in poly-Si, three kinds of laser energy density were used during crystallization to control the protrusion height. The device with lowest protrusions demonstrates the smallest degradation after undergoing long-term bending.

  17. Long term patterns in dissolved organic carbon, major elements and trace metals in boreal headwater catchments: trends, mechanisms and heterogeneity

    Directory of Open Access Journals (Sweden)

    S. K. Oni

    2012-12-01

    Full Text Available The boreal landscape is a complex, spatio-temporally varying mosaic of forest and mire landscape elements that control surface water hydrology and chemistry. Here, we assess long-term water quality time-series from three nested headwater streams draining upland forest (C2, peat/mire (C4 and mixed (C7 (forest and mire catchments. Temporal trends in weather and runoff (1981–2008; dissolved organic carbon concentration [DOC] (1993–2010 and other water quality parameters (1987–2011 were assessed. There was no significant annual trend in precipitation or runoff but a significant monotonic increasing trend existed in air temperature and length of growing season. Stream [DOC] was positively correlated with some trace metals (copper, iron and zinc and negatively with several other chemical parameters (e.g. sulfate, conductivity, calcium. Both sulfate and conductivity showed declining trends, while a significant increase was observed in pH during winter and spring. Calcium and magnesium showed monotonic decreasing trends. The declining trajectories of stream base cation and sulfate concentrations during other times of the year were not accompanied by changes in pH and alkalinity. Water temperature increased significantly both annually and in most months while iron and DOC concentrations showed significant increases in autumn months. Though all streams showed significant positive trends in [DOC] in autumn, only C2 had a significant annual increasing trend. There was also a shift in the magnitude of variability in spring [DOC] and increasing trend of summer baseflow [DOC] in C2 and C7.

  18. Effects of Chronic Vitamin D3 Hormone Administration on Anxiety-Like Behavior in Adult Female Rats after Long-Term Ovariectomy

    Directory of Open Access Journals (Sweden)

    Julia Fedotova

    2017-01-01

    Full Text Available The present preclinical study was created to determine the therapeutic effects of vitamin D hormone treatment as an adjunctive therapy alone or in a combination with low dose of 17β-estradiol (17β-E2 on anxiety-like behavior in female rats with long-term absence of estrogen. Accordingly, the aim of the current study was to examine the effects of chronic cholecalciferol administration (1.0, 2.5 or 5.0 mg/kg subcutaneously, SC, once daily, for 14 days on the anxiety-like state after long-term ovariectomy in female rats. Twelve weeks postovariectomy, cholecalciferol was administered to ovariectomized (OVX rats and OVX rats treated with 17β-E2 (0.5 µg/rat SC, once daily, for 14 days. Anxiety-like behavior was assessed in the elevated plus maze (EPM and the light/dark test (LDT, and locomotor and grooming activities were tested in the open field test (OFT. Cholecalciferol at two doses of 1.0 and 2.5 mg/kg alone or in combination with 17β-E2 produced anxiolytic-like effects in OVX rats as evidenced in the EPM and the LDT, as well as increased grooming activity in the OFT. Our results indicate that cholecalciferol, at two doses of 1.0 and 2.5 mg/kg, has a profound anxiolytic-like effects in the experimental rat model of long-term estrogen deficiency.

  19. Long term dietary methoxychlor exposure in rats increases sodium solution consumption but has few effects on other sexually dimorphic behaviors.

    Science.gov (United States)

    Flynn, K M; Delclos, K B; Newbold, R R; Ferguson, S A

    2005-09-01

    Methoxychlor is an insecticide with estrogen-like activity, thus exposure during development might cause sexually dimorphic behavioral alterations. To evaluate this, pregnant rats consumed diets containing 0, 10, 100 or 1000 ppm methoxychlor from gestational day 7, and offspring continued on these diets until postnatal day (PND) 77. Assessments of sexually dimorphic behaviors in offspring indicated that intake of a 3.0% sodium chloride solution was significantly increased (41%) in males and females of the 1000 ppm group. No treatment group differed from controls in open field nor running wheel activity, play behavior, nor 0.3% saccharin solution intake. Offspring of the 1000 ppm group showed significantly decreased body weight, reaching 17% less than controls at PND 77, but not clearly related to their salt solution intake. During pregnancy, 1000 ppm dams consumed 23% less food and weighed 10% less than controls, but this did not affect litter outcomes. These results indicate that in rodents, developmental and chronic exposure to dietary methoxychlor alters the sexually dimorphic behavior of salt-solution intake in young adults of both sexes. Similar behavioral alterations with other xenoestrogens, and the potential for interactions among xenoestrogens, suggest that this report may minimize the true effects of dietary methoxychlor exposure.

  20. Effects of Physical Environment on Health and Behaviors of Residents With Dementia in Long-Term Care Facilities: A Longitudinal Study.

    Science.gov (United States)

    Lee, Sook Young; Chaudhury, Habib; Hung, Lillian

    2016-01-01

    The challenges in investigating the effects of the physical environment on residents with dementia include having a sample of comparable study groups and a lack of long-term follow-up evaluation. The current study attempted to address these two challenges by carefully matching residents and analyzing long-term measurement data. The aim of the study was to examine whether residents with dementia (N = 12) living in a traditional large-scale setting or a small-scale, home-like setting exhibit any difference in health and behaviors over time. Physical environmental assessment of the two care facilities was conducted using the Therapeutic Environment Screening Survey for Nursing Homes. Residents' behavioral assessments were performed using three tools at three assessments over a period of 1 year: (a) Multidimensional Observation Scale for Elderly Subjects, (b) Minimum Data Set, and (c) Dementia Care Mapping. The results suggest that older adults with dementia can have increased social interaction and engagement with the support of an optimal physical environment.

  1. Long-term neprilysin gene transfer is associated with reduced levels of intracellular Abeta and behavioral improvement in APP transgenic mice

    Directory of Open Access Journals (Sweden)

    Patrick Christina

    2008-11-01

    Full Text Available Abstract Background Proteolytic degradation has emerged as a key pathway involved in controlling levels of the Alzheimer's disease (AD-associated amyloid-β (Aβ peptide in the brain. The endopeptidase, neprilysin, has been implicated as a major Aβ degrading enzyme in mice and humans. Previous short and intermediate term studies have shown the potential therapeutic application of neprilysin by delivering this enzyme into the brain of APP transgenic mice using gene transfer with viral vectors. However the effects of long-term neprilysin gene transfer on other aspects of Aβ associated pathology have not been explored yet in APP transgenic mice. Results We show that the sustained expression of neprilysin for up to 6 months lowered not only the amyloid plaque load but also reduced the levels of intracellular Aβ immunoreactivity. This was associated with improved behavioral performance in the water maze and ameliorated the dendritic and synaptic pathology in the APP transgenic mice. Conclusion These data support the possibility that long-term neprilysin gene therapy improves behavioral and neurodegenerative pathology by reducing intracellular Aβ.

  2. Expectation value analysis of wave packet solutions for the quantum bouncer: Short-term classical and long-term revival behaviors

    Science.gov (United States)

    Doncheski, M. A.; Robinett, R. W.

    2001-10-01

    We discuss the time development of Gaussian wave packet solutions of the "quantum bouncer" (a quantum mechanical particle subject to a uniform downward force, above an impermeable flat surface). We focus on the evaluation and visualization of the expectation values and uncertainties of position and momentum variables during a single quasi-classical period as well as during the long-term collapsed phase and several revivals. This approach complements existing analytic and numerical analyses of this system, as well as being useful for comparison with similar results for the harmonic oscillator and infinite well cases.

  3. Expectation value analysis of wave packet solutions for the quantum bouncer: short-term classical and long-term revival behavior

    CERN Document Server

    Doncheski, M A

    2001-01-01

    We discuss the time development of Gaussian wave packet solutions of the quantum bouncer' (a quantum mechanical particle subject to a uniform downward force, above an impermeable flat surface). We focus on the evaluation and visualization of the expectation values and uncertainties of position and momentum variables during a single quasi-classical period as well as during the long term collapsed phase and several revivals. This approach complements existing analytic and numerical analyses of this system, as well as being useful for comparison with similar results for the harmonic oscillator and infinite well cases.

  4. First Long-Term Behavioral Records from Cuvier’s Beaked Whales (Ziphius cavirostris) Reveal Record-Breaking Dives

    Science.gov (United States)

    Schorr, Gregory S.; Falcone, Erin A.; Moretti, David J.; Andrews, Russel D.

    2014-01-01

    Cuvier’s beaked whales (Ziphius cavirostris) are known as extreme divers, though behavioral data from this difficult-to-study species have been limited. They are also the species most often stranded in association with Mid-Frequency Active (MFA) sonar use, a relationship that remains poorly understood. We used satellite-linked tags to record the diving behavior and locations of eight Ziphius off the Southern California coast for periods up to three months. The effort resulted in 3732 hr of dive data with associated regional movements – the first dataset of its kind for any beaked whale – and included dives to 2992 m depth and lasting 137.5 min, both new mammalian dive records. Deep dives had a group mean depth of 1401 m (s.d. = 137.8, n = 1142) and duration of 67.4 min (s.d. = 6.9). The group mean time between deep dives was 102.3 min (s.d. = 30.8, n = 783). While the previously described stereotypic pattern of deep and shallow dives was apparent, there was considerable inter- and intra-individual variability in most parameters. There was significant diel behavioral variation, including increased time near the surface and decreased shallow diving at night. However, maximum depth and the proportion of time spent on deep dives (presumed foraging), varied little from day to night. Surprisingly, tagged whales were present within an MFA sonar training range for 38% of days locations were received, and though comprehensive records of sonar use during tag deployments were not available, we discuss the effects frequent acoustic disturbance may have had on the observed behaviors. These data better characterize the true behavioral range of this species, and suggest caution should be exercised when drawing conclusions about behavior using short-term datasets. PMID:24670984

  5. First long-term behavioral records from Cuvier's beaked whales (Ziphius cavirostris) reveal record-breaking dives.

    Science.gov (United States)

    Schorr, Gregory S; Falcone, Erin A; Moretti, David J; Andrews, Russel D

    2014-01-01

    Cuvier's beaked whales (Ziphius cavirostris) are known as extreme divers, though behavioral data from this difficult-to-study species have been limited. They are also the species most often stranded in association with Mid-Frequency Active (MFA) sonar use, a relationship that remains poorly understood. We used satellite-linked tags to record the diving behavior and locations of eight Ziphius off the Southern California coast for periods up to three months. The effort resulted in 3732 hr of dive data with associated regional movements--the first dataset of its kind for any beaked whale--and included dives to 2992 m depth and lasting 137.5 min, both new mammalian dive records. Deep dives had a group mean depth of 1401 m (s.d. = 137.8, n = 1142) and duration of 67.4 min (s.d. = 6.9). The group mean time between deep dives was 102.3 min (s.d. = 30.8, n = 783). While the previously described stereotypic pattern of deep and shallow dives was apparent, there was considerable inter- and intra-individual variability in most parameters. There was significant diel behavioral variation, including increased time near the surface and decreased shallow diving at night. However, maximum depth and the proportion of time spent on deep dives (presumed foraging), varied little from day to night. Surprisingly, tagged whales were present within an MFA sonar training range for 38% of days locations were received, and though comprehensive records of sonar use during tag deployments were not available, we discuss the effects frequent acoustic disturbance may have had on the observed behaviors. These data better characterize the true behavioral range of this species, and suggest caution should be exercised when drawing conclusions about behavior using short-term datasets.

  6. First long-term behavioral records from Cuvier's beaked whales (Ziphius cavirostris reveal record-breaking dives.

    Directory of Open Access Journals (Sweden)

    Gregory S Schorr

    Full Text Available Cuvier's beaked whales (Ziphius cavirostris are known as extreme divers, though behavioral data from this difficult-to-study species have been limited. They are also the species most often stranded in association with Mid-Frequency Active (MFA sonar use, a relationship that remains poorly understood. We used satellite-linked tags to record the diving behavior and locations of eight Ziphius off the Southern California coast for periods up to three months. The effort resulted in 3732 hr of dive data with associated regional movements--the first dataset of its kind for any beaked whale--and included dives to 2992 m depth and lasting 137.5 min, both new mammalian dive records. Deep dives had a group mean depth of 1401 m (s.d. = 137.8, n = 1142 and duration of 67.4 min (s.d. = 6.9. The group mean time between deep dives was 102.3 min (s.d. = 30.8, n = 783. While the previously described stereotypic pattern of deep and shallow dives was apparent, there was considerable inter- and intra-individual variability in most parameters. There was significant diel behavioral variation, including increased time near the surface and decreased shallow diving at night. However, maximum depth and the proportion of time spent on deep dives (presumed foraging, varied little from day to night. Surprisingly, tagged whales were present within an MFA sonar training range for 38% of days locations were received, and though comprehensive records of sonar use during tag deployments were not available, we discuss the effects frequent acoustic disturbance may have had on the observed behaviors. These data better characterize the true behavioral range of this species, and suggest caution should be exercised when drawing conclusions about behavior using short-term datasets.

  7. Effects of Aβ exposure on long-term associative memory and its neuronal mechanisms in a defined neuronal network.

    Science.gov (United States)

    Ford, Lenzie; Crossley, Michael; Williams, Thomas; Thorpe, Julian R; Serpell, Louise C; Kemenes, György

    2015-05-29

    Amyloid beta (Aβ) induced neuronal death has been linked to memory loss, perhaps the most devastating symptom of Alzheimer's disease (AD). Although Aβ-induced impairment of synaptic or intrinsic plasticity is known to occur before any cell death, the links between these neurophysiological changes and the loss of specific types of behavioral memory are not fully understood. Here we used a behaviorally and physiologically tractable animal model to investigate Aβ-induced memory loss and electrophysiological changes in the absence of neuronal death in a defined network underlying associative memory. We found similar behavioral but different neurophysiological effects for Aβ 25-35 and Aβ 1-42 in the feeding circuitry of the snail Lymnaea stagnalis. Importantly, we also established that both the behavioral and neuronal effects were dependent upon the animals having been classically conditioned prior to treatment, since Aβ application before training caused neither memory impairment nor underlying neuronal changes over a comparable period of time following treatment.

  8. Addressing Relapse in Cognitive Behavioral Therapy for Panic Disorder: Methods for Optimizing Long-Term Treatment Outcomes

    Science.gov (United States)

    Arch, Joanna J.; Craske, Michelle G.

    2011-01-01

    In this paper, we present a client with panic disorder and agoraphobia who relapses following a full course of cognitive behavioral therapy (CBT). To frame the client's treatment, the major components of CBT for panic disorder with or without agoraphobia (PD/A) are reviewed. Likely reasons for the treatment's failure and strategies for improving…

  9. Eating behavior, weight problems and eating disorders in 101 long-term survivors of childhood-onset craniopharyngioma

    NARCIS (Netherlands)

    Hoffmann, Anika; Postma, Frank P.; Sterkenburg, Anthe S.; Gebhardt, Ursel; Mueller, Hermann L.

    Background: As a result of hypothalamic involvement and/or treatment-related hypothalamic damage, up to 75% of childhood craniopharyngioma patients develop hypothalamic obesity. Methods: Eating behavior was analyzed in 101 survivors of childhood craniopharyngioma, recruited from 1980 to 2001 in the

  10. The Long-Term Consequences of Vietnam-Era Conscription and Genotype on Smoking Behavior and Health.

    Science.gov (United States)

    Schmitz, Lauren; Conley, Dalton

    2016-01-01

    Research is needed to understand the extent to which environmental factors moderate links between genetic risk and the development of smoking behaviors. The Vietnam-era draft lottery offers a unique opportunity to investigate whether genetic susceptibility to smoking is influenced by risky environments in young adulthood. Access to free or reduced-price cigarettes coupled with the stress of military life meant conscripts were exposed to a large, exogenous shock to smoking behavior at a young age. Using data from the Health and Retirement Study (HRS), we interact a genetic risk score for smoking initiation with instrumented veteran status in an instrumental variables (IV) framework to test for genetic moderation (i.e. heterogeneous treatment effects) of veteran status on smoking behavior and smoking-related morbidities. We find evidence that veterans with a high genetic predisposition for smoking were more likely to have been smokers, smoke heavily, and are at a higher risk of being diagnosed with cancer or hypertension at older ages. Smoking behavior was significantly attenuated for high-risk veterans who attended college after the war, indicating post-service schooling gains from veterans' use of the GI Bill may have reduced tobacco consumption in adulthood.

  11. Long-Term, Multimodal Treatment of a Child with Asperger's Syndrome and Comorbid Disruptive Behavior Problems: A Case Illustration

    Science.gov (United States)

    Wymbs, Brian T.; Robb, Jessica A.; Chronis, Andrea M.; Massetti, Greta M.; Fabiano, Gregory A.; Arnold, Frances W.; Brice, Anne-Christina; Gnagy, Elizabeth M.; Pelham, William E., Jr.; Burrows-MacLean, Lisa; Hoffman, Martin T.

    2005-01-01

    Despite Asperger's Syndrome (AS) becoming a widely recognized disorder on the pervasive developmental spectrum, surprisingly few studies have assessed the utility of psychosocial and/or pharmacological treatments for children with AS. Further, studies have not examined the effects of treatment on disruptive behavior problems commonly exhibited by…

  12. Eating behavior, weight problems and eating disorders in 101 long-term survivors of childhood-onset craniopharyngioma

    NARCIS (Netherlands)

    Hoffmann, Anika; Postma, Frank P.; Sterkenburg, Anthe S.; Gebhardt, Ursel; Mueller, Hermann L.

    2015-01-01

    Background: As a result of hypothalamic involvement and/or treatment-related hypothalamic damage, up to 75% of childhood craniopharyngioma patients develop hypothalamic obesity. Methods: Eating behavior was analyzed in 101 survivors of childhood craniopharyngioma, recruited from 1980 to 2001 in the

  13. CARDIAC AND BEHAVIORAL-RESPONSES OF LONG-TERM OBESE AND LEAN ZUCKER RATS TO EMOTIONAL-STRESS

    NARCIS (Netherlands)

    NYAKAS, C; BALKAN, B; STEFFENS, AB; BOHUS, B

    1995-01-01

    Obesity is known as a risk factor in stress-related cardiovascular pathology in man. The length of obesity can be an important interacting variable. Therefore, cardiac and behavioral responses to emotional stress were studied in 1-year-old, genetically obese (fa/fa) and lean (Fa/-) male Zucker rats,

  14. Neural rhythms of change: Long-term improvement after successful treatment in children with disruptive behavior problems

    NARCIS (Netherlands)

    Woltering, S.; Liao, V.; Liu, Z.X.; Granic, I.

    2015-01-01

    Neural changes were investigated for children with disruptive behavior problems one year after a treatment program ended. Thirty-nine children and their parents visited the research lab before, after, and a year after treatment ended. During those lab visits, electroencephalography (EEG) was recorde

  15. CARDIAC AND BEHAVIORAL-RESPONSES OF LONG-TERM OBESE AND LEAN ZUCKER RATS TO EMOTIONAL-STRESS

    NARCIS (Netherlands)

    NYAKAS, C; BALKAN, B; STEFFENS, AB; BOHUS, B

    1995-01-01

    Obesity is known as a risk factor in stress-related cardiovascular pathology in man. The length of obesity can be an important interacting variable. Therefore, cardiac and behavioral responses to emotional stress were studied in 1-year-old, genetically obese (fa/fa) and lean (Fa/-) male Zucker rats,

  16. Effect of resin charged functional group, porosity, and chemical matrix on the long-term pharmaceutical removal mechanism by conventional ion exchange resins.

    Science.gov (United States)

    Wang, Wei; Li, Xiaofeng; Yuan, Shengliu; Sun, Jian; Zheng, Shaokui

    2016-10-01

    This study attempted to clarify the long-term pharmaceutical removal mechanism from sewage treatment plant effluent during the cyclical adsorption-regeneration operation of 5 commercial resin-based fixed-bed reactors with the simultaneous occurrence of electrostatic interactions and complex non-electrostatic interactions. It examined 12 pharmaceuticals belonging to 10 therapeutic classes with different predominant existing forms and hydrophobicities. Furthermore, the effect of the resin charged functional group (strong-base vs. strong-acid vs. non-ionic), porosity (macroporous vs. gel), and chemical matrix (polystyrenic vs. polyacrylic) on the mechanism was investigated to optimize resin properties and achieve higher pharmaceutical removal. The results reported herein indicate the importance of non-electrostatic interactions between pharmaceuticals and the resin backbone during short-term cyclical operation (i.e., the 1st adsorption-regeneration cycle). With the development of cyclical operation, however, non-electrostatic interaction-induced pharmaceutical removal generally decreased and even disappeared when equilibrium was achieved between the influent and the resin. Despite pharmaceutical therapeutic class or hydrophilicity, anion (or cation) exchange resin preferentially removed those pharmaceuticals that were predominantly present as organic anions (or cations) by ion exchange process during long-term cyclical operation (i.e., ≥6 adsorption-regeneration cycles). Besides pharmaceuticals predominantly present as undissociated molecules, some amphoteric pharmaceuticals containing large amounts of zwitterions were also difficult to remove by ion exchange resin. Additionally, neither resin porosity nor chemical matrix had any significant effect on the long-term pharmaceutical removal mechanism.

  17. Long-Term Maintenance of Therapeutic Gains Associated With Cognitive-Behavioral Therapy for Insomnia Delivered Alone or Combined With Zolpidem.

    Science.gov (United States)

    Beaulieu-Bonneau, Simon; Ivers, Hans; Guay, Bernard; Morin, Charles M

    2017-03-01

    To document the long-term sleep outcomes at 12 and 24 months after patients with chronic insomnia were treated with cognitive-behavioral therapy (CBT), either singly or combined with zolpidem medication. Participants were 160 adults with chronic insomnia. They were first randomized for a six-week acute treatment phase involving CBT alone or CBT combined with nightly zolpidem, and randomized for a six-month extended treatment phase involving CBT, no additional treatment, CBT combined with zolpidem as needed, or CBT with zolpidem tapered. This paper reports results of the 12- and 24-month follow-ups on the main outcome measures derived from the Insomnia Severity Index and sleep diaries. Clinical improvements achieved 6 months following the end of treatment were well-maintained in all four conditions, with insomnia remission rates ranging from 48% to 74% at the 12-month follow-up, and from 44% to 63% at the 24-month follow-up. Participants receiving CBT with zolpidem taper in the extended treatment phase had significantly better results than those receiving CBT with continued zolpidem as needed. The magnitude of improvements on sleep diary parameters was similar between conditions, with a slight advantage for the CBT with zolpidem taper condition. The addition of extended CBT did not alter the long-term outcome over improvements obtained during the initial 6-week CBT. The results suggest that CBT for insomnia, when delivered alone or in combination with medication, produce durable sleep improvements up to two years after completion of treatment. These long-term results indicate that even if a combined CBT plus medication approach provide an added benefit immediately after treatment, extending CBT while tapering medication produce better sustained improvements compared to continued use of medication as needed.

  18. The effects of quality of life on behavioral and psychological symptoms in elderly people with dementia residing at long-term care facilities.

    Science.gov (United States)

    Suzuki, Mizue; Hattori, Hideyuki; Fukuda, Koji; Ooshiro, Hajime; Saruhara, Takayuki; Furuta, Yoshie; Abe, Kunihiko; Kanamori, Masao

    2017-01-01

    The purpose of the present study was to clarify how quality of life (QOL) affects the behavioral and psychological symptoms of dementia (BPSDs) among elderly individuals with dementia within long-term care facilities (e.g., long-term healthcare facilities, sanatorium-type medical facilities, and special nursing homes for the elderly). Elderly individuals with dementia were evaluated to determine their activities of daily living (ADL; Katz), Mini-mental State Examination (MMSE), Neuropsychiatric Inventory (NPI), and Quality of life inventory for the elderly with dementia (QOLD) scores. The subjects were recruited from intermediate welfare facilities (n = 226, 43.7%), hospitals with supportive care (n=91, 17.6%), and intermediate care facilities (n = 200, 38.7%). The mean age of the subjects was 85.18±7.13 years. The NPI scores revealed that Agitation/Aggression was high among subjects who resided in healthcare health facilities and sanatorium-type medical facilities, while Apathy/Indifference was high in those who resided in special nursing homes. Additionally, a multiple regression analysis found that most of the NPI items, when set as independent variables, displayed a significant association with the same subscale of the QOLD. When each item of the NPI was set as a dependent variable in a multiple regression analysis, the scores were significantly related to both subscales of the QOLD. It is suggested that QOL should be maintained or improved in an effort to reduce the incidence of the associated BPSDs in long-term care facilities.

  19. Ethical dilemma: offering short-term extracorporeal membrane oxygenation support for terminally ill children who are not candidates for long-term mechanical circulatory support or heart transplantation.

    Science.gov (United States)

    Shankar, Venkat; Costello, John P; Peer, Syed M; Klugman, Darren; Nath, Dilip S

    2014-04-01

    The use of extracorporeal membrane oxygenation (ECMO) in terminally ill pediatric patients who are not candidates for long-term mechanical circulatory support or heart transplantation requires careful deliberation. We present the case of a 16-year-old female with a relapse of acute lymphoid leukemia and acute-on-chronic cardiomyopathy who received short-term ECMO therapy. In addition, we highlight several ethical considerations that were crucial to this patient's family-centered care and demonstrate that this therapy can be accomplished in a manner that respects patient autonomy and family wishes.

  20. Long-term Behavior of Serous Borderline Tumors Subdivided Into Atypical Proliferative Tumors and Noninvasive Low-grade Carcinomas

    DEFF Research Database (Denmark)

    Vang, Russell; Hannibal, Charlotte Gerd; Junge, Jette

    2017-01-01

    Ovarian serous borderline tumors (SBTs) have been the subject of considerable controversy, particularly with regard to terminology and behavior. It has been proposed that they constitute a heterogenous group of tumors composed, for the most part, of typical SBTs that are benign and designated...... "atypical proliferative serous tumor (APST)" and a small subset of SBTs with micropapillary architecture that have a poor outcome and are designated "noninvasive low-grade serous carcinoma (niLGSC)". It also has been argued that the difference in behavior between the 2 groups is not due to the subtype...... of the primary tumor but rather the presence of extraovarian disease, specifically invasive implants. According to the terminology of the 2014 WHO Classification, typical SBTs are equivalent to APSTs and SBTs displaying micropapillary architecture are synonymous with niLGSC. In addition, "invasive implants" were...

  1. Evidence for the long-term stability of HIV transmission-associated sexual behavior after HIV diagnosis.

    Science.gov (United States)

    Dombrowski, Julia C; Harrington, Robert D; Golden, Matthew R

    2013-01-01

    Most persons diagnosed as having HIV alter their sexual behavior in a way that reduces the risk of HIV transmission, but the durability of such behavior change is unknown. We conducted annual anonymous cross-sectional surveys in randomly selected patients with appointments at a large, public hospital HIV clinic in Seattle, Washington, from 2005 to 2009. We used logistic regression to assess the association between time since HIV diagnosis and self-report of unprotected anal or vaginal intercourse (UAVI) with partners of negative or unknown HIV status (nonconcordant UAVI), and quantile regression to evaluate the association between time since HIV diagnosis and number of anal or vaginal sex partners. We analyzed 845 surveys collected for 5 years. Men who have sex with men (MSM) had been diagnosed as having HIV a mean (standard deviation) of 12 (7) years and non-MSM a mean of 11 (6) years. Among 597 MSM, longer time since HIV diagnosis was associated with lower age-adjusted odds of reporting nonconcordant UAVI (odds ratio, 0.96 [95% confidence interval, 0.92-0.99]) and a lower age-adjusted number of sex partners (β coefficient = -0.03, P = 0.007). Among 248 women and heterosexual men, time since HIV diagnosis was not significantly associated with age-adjusted odds of nonconcordant UAVI (odds ratio 0.99 [95% confidence interval, 0.93-1.04]) or number of sex partners (β coefficient = -0.01, P = 0.48). These results indicate that HIV transmission-associated behavior is relatively stable following the first year after HIV diagnosis. Our findings suggest that behavior change in the first year after HIV diagnosis, reported in other studies, is durable.

  2. Modelling of long term geochemical evolution and study of mechanical perturbation of bentonite buffer of a KBS-3 repository

    Energy Technology Data Exchange (ETDEWEB)

    Marsal, Francois; Pellegrini, Delphine; Deleruyelle, Frederic; Serres, Christophe (French Institute for Radiological Protection and Nuclear Safety (IRSN) (FR)); Windt, Laurent de (Paris School of Mines (ENSMP) (FR))

    2008-03-15

    The Swedish Nuclear Fuel and Waste Management Co. (SKB) has recently completed a safety assessment project named SR-Can, related to the KBS-3 disposal concept. In this concept, the waste packages are surrounded by a buffer made of either MX-80 or Deponit CA-N bentonite. Interactions between the buffer and groundwater may modify the buffer composition and thus its containment properties. The Swedish Radiation Protection Authorities (SSI) requested the French Institute for Radiological Protection and Nuclear Safety (IRSN) to perform the present study in support of SSI review of the SR-Can report. The purpose is to assess the geochemical evolution of both potential buffer materials due to the intrusion of different types of groundwater, with a similar modelling layout to that reported in SR-Can. Three main categories of water inflows via a fracture intersecting a deposition hole are considered: the Forsmark reference groundwater, a high-salinity groundwater to account for up-rise of deep-seated brines and a diluted water representing ice-melting derived groundwater. In addition to this, the redox buffering capacity of Deponit CA-N bentonite and the thermal effect on MX-80 bentonite geochemistry have been assessed. This modelling work has been performed using the reactive transport modelling code HYTEC. The main outcome of the present study is that the intrusion of the considered groundwaters should not affect drastically the geochemistry of neither the Deponit CA-N nor the MX-80 bentonite on the long-term (100,000 y). Bentonite pH may reach high values (up to 10.5) in some cases but does not reach SKB criterion value related to bentonite chemical stability. Dissolution-precipitation of accessory minerals is not significant enough to induce important porosity changes (rise by maximum 2 %). Globally, the montmorillonite exchanger undergoes Na by Ca partial replacement, which may decrease the swelling pressure of the bentonite. The simulated intrusion of oxidizing waters

  3. Long-term betamethasone 21-phosphate disodium treatment has distinct effects in CD1 and DBA/2 mice on animal behavior accompanied by opposite effects on neurogenesis.

    Science.gov (United States)

    Aiello, Rossana; Crupi, Rosalia; Leo, Antonio; Chimirri, Serafina; Rispoli, Vincenzo; Marra, Rosario; Citraro, Rita; Cuzzocrea, Salvatore; De Sarro, Giovambattista; Russo, Emilio

    2015-02-01

    One of the most peculiar characteristics of the stress response is the pronounced inter-individual and inter-strain variability both in behavioral and neurochemical outcomes. Several studies confirm that rodents belonging to the same or different strain and/or gender, when exposed to a stressor, may show behavioral and cognitive differences. We compared the effects of long-term betamethasone 21-phosphate disodium (BTM), a widely clinically used corticosteroid, on animal behavior and neurogenesis in CD1 and DBA/2 mice. BTM treatment, in CD1 mice, increased body weight gain and anxiety parameters while having pro-depressant effects. Furthermore, BTM significantly reduced neurogenesis in the dentate gyrus of the hippocampus. Finally, BTM treatment induced a significant impairment in memory and learning performance in the Morris water maze. At odds, BTM administration, in DBA/2 mice, caused a significant reduction in the body weight while not modifying anxiety parameters. In addition, both an increased synaptogenesis and neurogenesis were found. Similarly to CD1 mice, also in DBA/2 mice, memory and learning were impaired. Our data confirm that long-term exposure to corticosteroids can generate or aggravate psychiatric/neurologic disorders such as depression, anxiety, memory and learning. Our study did not reveal significant differences between corticosterone and BTM treatment in CD1 mice. In contrast, BTM treatment in mice with an anxious phenotype (DBA/2 mice) revealed some contrasting results indicating that genetic factors can influence corticosteroids dependent effects. Finally, our data further underline the need for a re-evaluation of neurogenesis role; the increased neurogenesis observed in DBA/2 mice and behavioral effects might be distinguished phenomena.

  4. Early and long-term effects of low- and high-LET radiation on rat behavior and monoamine metabolism in different brain regions

    Science.gov (United States)

    Belov, Oleg

    Space radiation is one of the factors representing a significant health risk to the astronauts during deep-space missions. A most harmful component of space radiation beyond the Earth's magnetosphere is the galactic cosmic rays which are composed of high-energy protons, α particles, and high charge and energy (HZE) nuclei. Recent studies performed at particle accelerators have revealed a significant impact of HZE nuclei on the central nervous system and, in particular, on the cognitive functions. However the exact molecular mechanisms behind the observed impairments remain mostly unclear. This research is focused on study of early and long-term effects of low- and high-linear-energy-transfer (LET) radiation on the rat behavior and monoamine metabolism in the brain regions involved in behavior and motor control and form emotional and motivational states. Different groups of rats were whole-body exposed to 500 MeV/u (12) C particles (LET 10.6 keV/µm) available at the Nuclotron accelerator of the Joint Institute for Nuclear Research (Dubna, Russia) and to gamma rays at the equivalent dose of 1 Gy. An additional group of animals was sham-irradiated and considered as a control. The isolated brain regions have included the prefrontal cortex, nucleus accumbens, hypothalamus, hippocampus, and striatum where we determined the concentrations of noradrenalin, dopamine and its metabolites 3,4-doxyphenylacetic acid, homovanillic acid, and 3-methoxytyramine and serotonin and its metabolite 5-hydroxyindoleacetic acid. The following effects were observed in the different periods after irradiation. 1 day after exposure to (12) C particles strong changes in the concentration of monoamines and their metabolites were observed in three structures, namely, the prefrontal cortex, nucleus accumbens, and hippocampus. However, significant changes were found in the prefrontal cortex and weaker changes were seen in the nucleus accumbens, whereas changes were insignificant in the hippocampus

  5. Long-term prevention of Alzheimer's disease-like behavioral deficits in PDAPP mice carrying a mutation in Asp664.

    Science.gov (United States)

    Galvan, Veronica; Zhang, Junli; Gorostiza, Olivia F; Banwait, Surita; Huang, Wei; Ataie, Marina; Tang, Huidong; Bredesen, Dale E

    2008-08-22

    The deficits of Alzheimer's disease (AD) are believed to result, at least in part, from neurotoxicity of beta-amyloid (Abeta), a set of 38-43 amino acid fragments derived from the beta-amyloid precursor protein (APP). In addition, APP generates the APP-C31 and Jcasp toxic fragments intracellularly by cleavage at Asp664. We reported that mutation of Asp664 to Ala in a FAD-human APP transgene prevented AD-like deficits but did not affect Abeta production or deposition in PDAPP mice, arguing that D664A plays a crucial role in the generation of AD-like deficits. Whether D664A simply delays or completely prevents AD-like deficits, however, remained undefined. To address this question, we performed behavioral studies longitudinally on a pretrained mouse cohort at 9 and 13 months (mo) of age. While behavioral deficits were present in PDAPP mice, performance of Tg PDAPP(D664A) mice was not significantly different from non-Tg littermates' across all ages tested. Moreover, aberrant patterns in non-cognitive components of behavior in PDAPP mice were ameliorated in PDAPP(D664A) animals as well. A trend towards poorer retention at 9 mo and poorer learning at 13 mo that did not reach statistical significance was observed in PDAPP(D664A) mice. These results support and extend recent studies showing that cleavage of APP at Asp664 (or protein-protein interactions dependent on Asp664) is a crucial event in the generation of AD-like deficits in PDAPP mice. Our results thus further demonstrate that the D664A mutation either completely precludes, or markedly delays (beyond 13 mo) the appearance of AD-like deficits in this mouse model of AD.

  6. Brief predator sound exposure elicits behavioral and neuronal long-term sensitization in the olfactory system of an insect

    DEFF Research Database (Denmark)

    Anton, S.; Evengaard, K.; Barrozo, R. B.

    2011-01-01

    these processes have been described. However, the influence of sensory signals on the sensitivity of a different modality is largely unknown. In males of the noctuid moth, Spodoptera littoralis, the sensitivity to the female-produced sex pheromone increases 24 h after a brief preexposure with pheromone...... at the behavioral and central nervous level. Here we show that this effect is not confined to the same sensory modality: the sensitivity of olfactory neurons can also be modulated by exposure to a different sensory stimulus, i.e., a pulsed stimulus mimicking echolocating sounds from attacking insectivorous bats. We......, but also on the central nervous level, in an insect....

  7. Long-term exposure to paraquat alters behavioral parameters and dopamine levels in adult zebrafish (Danio rerio).

    Science.gov (United States)

    Bortolotto, Josiane W; Cognato, Giana P; Christoff, Raissa R; Roesler, Laura N; Leite, Carlos E; Kist, Luiza W; Bogo, Mauricio R; Vianna, Monica R; Bonan, Carla D

    2014-04-01

    Chronic exposure to paraquat (Pq), a toxic herbicide, can result in Parkinsonian symptoms. This study evaluated the effect of the systemic administration of Pq on locomotion, learning and memory, social interaction, tyrosine hydroxylase (TH) expression, dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels, and dopamine transporter (DAT) gene expression in zebrafish. Adult zebrafish received an i.p. injection of either 10 mg/kg (Pq10) or 20 mg/kg (Pq20) of Pq every 3 days for a total of six injections. Locomotion and distance traveled decreased at 24 h after each injection in both treatment doses. In addition, both Pq10- and Pq20-treated animals exhibited differential effects on the absolute turn angle. Nonmotor behaviors were also evaluated, and no changes were observed in anxiety-related behaviors or social interactions in Pq-treated zebrafish. However, Pq-treated animals demonstrated impaired acquisition and consolidation of spatial memory in the Y-maze task. Interestingly, dopamine levels increased while DOPAC levels decreased in the zebrafish brain after both treatments. However, DAT expression decreased in the Pq10-treated group, and there was no change in the Pq20-treated group. The amount of TH protein showed no significant difference in the treated group. Our study establishes a new model to study Parkinson-associated symptoms in zebrafish that have been chronically treated with Pq.

  8. Corporal punishment and long-term behavior problems: the moderating role of positive parenting and psychological aggression.

    Science.gov (United States)

    Gámez-Guadix, Manuel; Straus, Murray A; Carrobles, José Antonio; Muñoz-Rivas, Marina J; Almendros, Carmen

    2010-11-01

    The aims of this study were: (a) to examine the prevalence of corporal punishment (CP) of children in Spain; (b) to analyze the extent to which CP is used in combination with psychological aggression and positive parenting among Spanish parents; and (c) to investigate whether the relation between CP and behavior problems is moderated by a positive parenting context in which CP may be used, and by the co-occurrence of psychological aggression. The sample comprised 1,071 Spanish university students (74.8% female; 25.2% male). Findings indicate a high prevalence of CP of Spanish students, revealing that significantly more mothers than fathers used CP. Furthermore, more CP is related to more use of psychological aggression and less of positive parenting. Regression analyses revealed that CP was associated with an increased probability of antisocial traits and behaviors regardless of whether there was positive parenting and psychological aggression. These results highlight that, though many Spanish parents use CP as a disciplinary strategy, it appears to be related to negative outcomes for children regardless the parental context in which it is used.

  9. Long-term follow-up of a randomized controlled trial comparing acceptance and commitment therapy and standard cognitive behavior therapy for anxiety and depression.

    Science.gov (United States)

    Forman, Evan M; Shaw, Jena A; Goetter, Elizabeth M; Herbert, James D; Park, Jennie A; Yuen, Erica K

    2012-12-01

    The present study represents one of the first comparisons of the long-term effectiveness of traditional cognitive behavior therapy (i.e., Beckian cognitive therapy; CT) and acceptance and commitment therapy (ACT). One hundred thirty-two anxious or depressed outpatients were randomly assigned to receive either CT or ACT, and were assessed at posttreatment (n=90) and at 1.5-year (n=91) follow-up. As previously reported, the two treatments were equivalently effective at posttreatment according to measures of depression, anxiety, overall (social/occupational/symptom-related) functioning, and quality of life. However, current results suggest that treatment gains were better maintained at follow-up in the CT condition. Clinical significance analyses revealed that, at follow-up, one-third more CT patients were in the clinically normative range in terms of depressive symptoms and more than twice as many CT patients were in the normative range in terms of functioning levels. The possible long-term advantage of CT relative to ACT in this population is discussed. Copyright © 2012. Published by Elsevier Ltd.

  10. Investigation of structure-property relationships of polyisobutylene-based biomaterials: Morphology, thermal, quasi-static tensile and long-term dynamic fatigue behavior.

    Science.gov (United States)

    Götz, C; Lim, G T; Puskas, J E; Altstädt, V

    2012-06-01

    This study examines the morphology, thermal, quasi-static and long-term dynamic creep properties of one linear and three arborescent polyisobutylene-based block copolymers (L_SIBS31, D_IBS16, D_IBS27 and D_IBS33). Silicone rubber, a common biopolymer, was considered as a benchmark material for comparison. A unique hysteretic testing methodology of Stepwise Increasing Load Test (SILT) and Single Load Test (SLT) was used in this study to evaluate the long-term dynamic fatigue performance of these materials. Our experimental findings revealed that the molecular weight of polyisobutylene (PIB) and polystyrene (PS) arms [M(n)(PIB(arm)) and M(n)(PS(arm))], respectively had a profound influence on the nano-scaled phase separation, quasi-static tensile, thermal transition, and dynamic creep resistance behaviors of these PIB-based block copolymers. However, silicone rubber outperformed the PIB-based block copolymers in terms of dynamic creep properties due to its chemically crosslinked structure. This indicates a need for a material strategy to improve the dynamic fatigue and creep of this class of biopolymers to be considered as alternative to silicone rubber for biomedical devices.

  11. Physical activity, sedentary behavior, and long-term cardiovascular risk in young people: A review and discussion of methodology in prospective studies

    Directory of Open Access Journals (Sweden)

    Jakob Tarp

    2016-06-01

    Full Text Available The long-term effects of physical activity (PA or sedentary behavior on cardiovascular health in young people are not well understood. In this study, we use a narrative format to review the evidence for a prospective association with adiposity and other well-established biological cardiovascular risk factors in healthy young people, considering only studies with at least 2 years of follow-up. PA appears to elicit a long-term beneficial effect on adiposity and particularly markers of cardiovascular health. With adiposity, however, a few studies also reported that higher levels of PA were associated with higher levels of adiposity. Time spent sedentary does not appear to be related to adiposity or markers of cardiovascular health independent of PA. We then discuss the uncertainties in the underlying causal chain and consider a number of alternative modeling strategies, which could improve our understanding of the relationship in future studies. Finally, we consider the current methodology for assessing PA and sedentary time.

  12. Long-term impact of community-based information, education and communication activities on food hygiene and food safety behaviors in Vietnam: a longitudinal study.

    Directory of Open Access Journals (Sweden)

    Kumiko Takanashi

    Full Text Available BACKGROUND: Ingestion of contaminated water or food is a major contributor to childhood diarrhea in developing countries. In Vietnam, the use of community-based information, education and communication (IEC activities could be a sustainable strategy to improve food hygiene and food safety behaviors. This study thus examined the long-term impact of community-based IEC activities on food hygiene and food safety behaviors. METHODS: In this longitudinal study, we interviewed caregivers of children aged between six months and four years in suburban Hanoi. Baseline data were collected in January 2006 (n = 125. After conducting IEC interventions, we collected a 1(st set of evaluation data in January 2007 (n = 132. To examine the long-term impact of the interventions, we then collected a 2(nd set of evaluation data in January 2008 (n = 185. Changes in childhood diarrhea prevalence, IEC coverage, and food hygiene and food safety behaviors were assessed over a two-year period using bivariate and logistic regression analyses. Effective IEC channels were determined through multiple linear regression analysis. RESULTS: Childhood diarrhea was significantly reduced from 21.6% at baseline to 7.6% at the 1(st post-intervention evaluation (P = 0.002, and to 5.9% at the 2(nd evaluation. Among 17 food hygiene and food safety behaviors measured, a total of 11 behaviors were improved or maintained by the 2(nd evaluation. Handwashing after toilet use was significantly improved at both evaluation points. Overall, 3 food safety behaviors and 7 food hygiene behaviors were found to have significantly improved at the 1(st and at the 2(nd evaluations, respectively. Flip chart communication administered by community groups was identified to be the most effective IEC channel for effecting behavior change (P = 0.018. CONCLUSIONS: Flip chart communication administered by community groups is effective for improving multiple food hygiene and food safety

  13. Long-term impact of community-based information, education and communication activities on food hygiene and food safety behaviors in Vietnam: a longitudinal study.

    Science.gov (United States)

    Takanashi, Kumiko; Quyen, Dao To; Le Hoa, Nguyen Thi; Khan, Nguyen Cong; Yasuoka, Junko; Jimba, Masamine

    2013-01-01

    Ingestion of contaminated water or food is a major contributor to childhood diarrhea in developing countries. In Vietnam, the use of community-based information, education and communication (IEC) activities could be a sustainable strategy to improve food hygiene and food safety behaviors. This study thus examined the long-term impact of community-based IEC activities on food hygiene and food safety behaviors. In this longitudinal study, we interviewed caregivers of children aged between six months and four years in suburban Hanoi. Baseline data were collected in January 2006 (n = 125). After conducting IEC interventions, we collected a 1(st) set of evaluation data in January 2007 (n = 132). To examine the long-term impact of the interventions, we then collected a 2(nd) set of evaluation data in January 2008 (n = 185). Changes in childhood diarrhea prevalence, IEC coverage, and food hygiene and food safety behaviors were assessed over a two-year period using bivariate and logistic regression analyses. Effective IEC channels were determined through multiple linear regression analysis. Childhood diarrhea was significantly reduced from 21.6% at baseline to 7.6% at the 1(st) post-intervention evaluation (P = 0.002), and to 5.9% at the 2(nd) evaluation. Among 17 food hygiene and food safety behaviors measured, a total of 11 behaviors were improved or maintained by the 2(nd) evaluation. Handwashing after toilet use was significantly improved at both evaluation points. Overall, 3 food safety behaviors and 7 food hygiene behaviors were found to have significantly improved at the 1(st) and at the 2(nd) evaluations, respectively. Flip chart communication administered by community groups was identified to be the most effective IEC channel for effecting behavior change (P = 0.018). Flip chart communication administered by community groups is effective for improving multiple food hygiene and food safety behaviors in sustainable ways, and should be included in

  14. The predominant mechanism of intercellular calcium wave propagation changes during long-term culture of human osteoblast-like cells

    DEFF Research Database (Denmark)

    Henriksen, Zanne; Hiken, Jeffrey F; Steinberg, Thomas H;

    2006-01-01

    Intercellular calcium waves (ICW) are calcium transients that spread from cell to cell in response to different stimuli. We previously demonstrated that human osteoblast-like cells in culture propagate ICW in response to mechanical stimulation by two mechanisms. One mechanism involves autocrine...... assessed by video imaging of Fura-2 loaded cells after 1, 2 and 4 months culture. The P2Y2 receptor and the gap junction protein Cx43 were assessed by Western blot and real-time PCR. In resting conditions, P2Y mediated ICW prevailed and spread rapidly to about 13 cells. P2Y receptor desensitization by ATP......, but as cells differentiate in culture, gap-junction-mediated ICW become more prominent. These results suggest that P2Y receptor-mediated and gap junction-mediated mechanisms of intercellular calcium signaling may play different roles during differentiation of bone-forming cells....

  15. The impact of chronic mild stress on long-term depressive behavior in rats which have survived sepsis.

    Science.gov (United States)

    Steckert, Amanda V; Dominguini, Diogo; Michels, Monique; Abelaira, Helena M; Tomaz, Débora B; Sonai, Beatriz; de Moura, Airam B; Matos, Danyela; da Silva, Júlia B I; Réus, Gislaine Z; Barichello, Tatiana; Quevedo, João; Dal-Pizzol, Felipe

    2017-11-01

    The present study was created to investigate the effects of chronic mild stress (CMS) on the depressive behavior and neurochemical parameters of rats that were subjected to sepsis. Wistar rats were subjected to a CMS protocol, and sepsis was induced by cecal ligation and perforation (CLP). The animals were then divided into 4 separate groups; Control + Sham (n = 20), Control + CLP (n = 30), CMS + Sham (n = 20) and CMS + CLP (n = 30). Body weight, food and water intake and mortality were measured on a daily basis for a period of 10 days after the induction of sepsis. Locomotor activity, splash and forced swimming tests were performed ten days after CLP. At the end of the test period, the animals were euthanized, and the prefrontal cortex and hippocampus were removed to determine the levels of cytokines and oxidative damage. Our results show that there was no significant interaction between CMS and CLP in relation to locomotor activity and the forced swimming test. However, we did observe a significant decrease in total grooming time in the Control + CLP and CMS + Sham groups, with the CMS + CLP group showing behavior similar to that of the control animals. This was found to be related to a decrease in the levels of brain cytokines, and not to oxidative damage parameters. Collectively, our results suggest that a previous stress caused by CMS can protect the brain against the systemic acute and severe stress elicited by sepsis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Long-term running alleviates some behavioral and molecular abnormalities in Down syndrome mouse model Ts65Dn.

    Science.gov (United States)

    Kida, Elizabeth; Rabe, Ausma; Walus, Marius; Albertini, Giorgio; Golabek, Adam A

    2013-02-01

    Running may affect the mood, behavior and neurochemistry of running animals. In the present study, we investigated whether voluntary daily running, sustained over several months, might improve cognition and motor function and modify the brain levels of selected proteins (SOD1, DYRK1A, MAP2, APP and synaptophysin) in Ts65Dn mice, a mouse model for Down syndrome (DS). Ts65Dn and age-matched wild-type mice, all females, had free access to a running wheel either from the time of weaning (post-weaning cohort) or from around 7 months of age (adult cohort). Sedentary female mice were housed in similar cages, without running wheels. Behavioral testing and evaluation of motor performance showed that running improved cognitive function and motor skills in Ts65Dn mice. However, while a dramatic improvement in the locomotor functions and learning of motor skills was observed in Ts65Dn mice from both post-weaning and adult cohorts, improved object memory was seen only in Ts65Dn mice that had free access to the wheel from weaning. The total levels of APP and MAP2ab were reduced and the levels of SOD1 were increased in the runners from the post-weaning cohort, while only the levels of MAP2ab and α-cleaved C-terminal fragments of APP were reduced in the adult group in comparison with sedentary trisomic mice. Hence, our study demonstrates that Ts65Dn females benefit from sustained voluntary physical exercise, more prominently if running starts early in life, providing further support to the idea that a properly designed physical exercise program could be a valuable adjuvant to future pharmacotherapy for DS.

  17. Forebrain overexpression of CaMKII abolishes cingulate long term depression and reduces mechanical allodynia and thermal hyperalgesia

    Directory of Open Access Journals (Sweden)

    Tsien Joe Z

    2006-06-01

    Full Text Available Abstract Activity-dependent synaptic plasticity is known to be important in learning and memory, persistent pain and drug addiction. Glutamate NMDA receptor activation stimulates several protein kinases, which then trigger biochemical cascades that lead to modifications in synaptic efficacy. Genetic and pharmacological techniques have been used to show a role for Ca2+/calmodulin-dependent kinase II (CaMKII in synaptic plasticity and memory formation. However, it is not known if increasing CaMKII activity in forebrain areas affects behavioral responses to tissue injury. Using genetic and pharmacological techniques, we were able to temporally and spatially restrict the over expression of CaMKII in forebrain areas. Here we show that genetic overexpression of CaMKII in the mouse forebrain selectively inhibits tissue injury-induced behavioral sensitization, including allodynia and hyperalgesia, while behavioral responses to acute noxious stimuli remain intact. CaMKII overexpression also inhibited synaptic depression induced by a prolonged repetitive stimulation in the ACC, suggesting an important role for CaMKII in the regulation of cingulate neurons. Our results suggest that neuronal CaMKII activity in the forebrain plays a role in persistent pain.

  18. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  19. Resin Systems and Chemistry-Degradation Mechanisms and Durability in Long-Term Durability of Polymeric Matrix Composites. Chapter 1

    Science.gov (United States)

    Hinkley, Jeffrey A.; Connell, John W.

    2012-01-01

    In choosing a polymer-matrix composite material for a particular application, a number of factors need to be weighed. Among these are mechanical requirements, fabrication method (e.g. press-molding, resin infusion, filament winding, tape layup), and use conditions. Primary among the environmental exposures encountered in aerospace structures are moisture and elevated temperatures, but certain applications may require resistance to other fluids and solvents, alkaline agents, thermal cycling, radiation, or rapid, localized heating (for example, lightning strike). In this chapter, the main classes of polymer resin systems found in aerospace composites will be discussed. Within each class, their responses to environmental factors and the associated degradation mechanisms will be reviewed.

  20. SPECIFIC DEGRADATION STRUCTURE FEATURES AND MECHANICAL PROPERTIES OF FURNACE AND HEAT POWER EQUIPMENT ELEMENTS AFTER LONG-TERM OPERATION

    Directory of Open Access Journals (Sweden)

    F. Panteleenko

    2012-01-01

    Full Text Available The paper presents results of investigations on structure and mechanical properties of technological equipment elements made of heat-resistant steels. A scale of chrome and molybdenum steel microstructure degradation based on evaluation of  coagulated carbide size and material mechanical properties (a point from 0-operation without time limits, up to 4-operation prohibition has been proposed in the paper. It has been  established that an analysis of  steel microstructure directly on equipment elements by means of a portable microscope is an efficient express method for evaluation of equipment condition and structures due to control of material structure degradation rate of a diagnosed object.

  1. Experimental study of kinetic and mechanism of dissolution of apatite structured minerals. Application to the prediction of the long term behavior of an actinides storage host matrix; Etude experimentale de la cinetique et des mecanismes d'alteration de mineraux apatitiques. Application au comportement d'une ceramique de confinement d'actinides mineurs

    Energy Technology Data Exchange (ETDEWEB)

    Chairat, C

    2005-11-15

    The motivation for this study is to assess the potential of using apatite structured ceramics as long-lived actinide storage hosts. To assess their ability to resist aqueous corrosion, the dissolution of natural fluoro-apatite and synthetic Nd-britholite (neodymium is a proxy for the trivalent actinides) was studied. Mineral surfaces were characterized using a combined spectrometric, electrokinetic and potentiometric approach and dissolution rates were measured in closed and open system reactors as a function of solution composition. Experimental results suggest apatitic minerals dissolve via distinct step sequence: 1) fluoride release, 2) release of the calcium situated in the M1, and 3) the simultaneous removal of phosphate and calcium II via the breaking of only Ca-O bonds. TST based rate equations based in this mechanism accurately describe fluoro-apatite and synthetic britholite dissolution rates as a function of solution composition. Nd release rates are limited by precipitation of Nd-rhabdophane. (author)

  2. Long-Term Electrophysiological and Behavioral Analysis on the Improvement of Visual Working Memory Load, Training Gains, and Transfer Benefits.

    Science.gov (United States)

    Kuo, Ching-Chang; Zhang, Cheng; Rissman, Robert A; Chiu, Alan W L

    2014-05-01

    Recent evidence demonstrates that with training, one can enhance visual working memory (VWM) capacity and attention over time in the near transfer tasks. Not only do these studies reveal the characteristics of VWM load and the influences of training, they may also provide insights into developing effective rehabilitation for patients with VWM deficiencies. However, few studies have investigated VWM over extended periods of time and evaluated transfer benefits on non-trained tasks. Here, we combined behavioral and electroencephalographical approaches to investigate VWM load, training gains, and transfer benefits. Our results reveal that VWM capacity is directly correlated to the difference of event-related potential waveforms. In particular, the "magic number 4" can be observed through the contralateral delay amplitude and the average capacity is 3.25-item over 15 participants. Furthermore, our findings indicate that VWM capacity can be improved through training; and after training exercises, participants from the training group are able to dramatically improve their performance. Likewise, the training effects on non-trained tasks can also be observed at the 12th week after training. Therefore, we conclude that participants can benefit from training gains, and augmented VWM capacity sustained over long periods of time on specific variety of tasks.

  3. Long-term effects of psychotherapy on moderate depression: a comparative study of narrative therapy and cognitive-behavioral therapy.

    Science.gov (United States)

    Lopes, Rodrigo T; Gonçalves, Miguel M; Fassnacht, Daniel B; Machado, Paulo P P; Sousa, Inês

    2014-01-01

    In a previous clinical controlled trial (Lopes et al., 2014), narrative therapy (NT) showed promising results in ameliorating depressive symptoms with comparable outcomes to cognitive-behavioral therapy (CBT) when patients completed treatment. This paper aims to assess depressive symptoms and interpersonal problems in this clinical sample at follow-up. Using the Beck Depression Inventory-II and Outcome Questionnaire-45.2 Interpersonal Relations Scale, naturalistic prospective follow-up assessment was conducted at 21 and 31 months after the last treatment session. At follow-up, patients kept improving in terms of depressive symptoms and interpersonal problems. The odds that a patient maintained recovery from depressive symptoms at follow-up were five times higher than the odds that a patient maintained recovery from interpersonal problems. In the same way, the odds of a patient never recovering from interpersonal problems were five times higher than the odds of never recovering from depressive symptoms. The study did not control for the natural course of depression or treatment continuation. For depressed patients with greater interpersonal disabilities, longer treatment plans and alternative continuation treatments should be considered. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Acutely applied MDMA enhances long-term potentiation in rat hippocampus involving D1/D5 and 5-HT2 receptors through a polysynaptic mechanism.

    Science.gov (United States)

    Rozas, C; Loyola, S; Ugarte, G; Zeise, M L; Reyes-Parada, M; Pancetti, F; Rojas, P; Morales, B

    2012-08-01

    3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a drug of abuse that induces learning and memory deficit. However, there are no experimental data that correlate the behavioral evidence with models of synaptic plasticity such as long-term potentiation (LTP) or long-term depression (LTD). Using field potential recordings in rat hippocampal slices of young rats, we found that acute application of MDMA enhances LTP in CA3-CA1 synapses without affecting LTD. Using specific antagonists and paired-pulse facilitation protocols we observed that the MDMA-dependent increase of LTP involves presynaptic 5-HT₂ serotonin receptors and postsynaptic D1/D5 dopamine receptors. In addition, the inhibition of PKA suppresses the MDMA-dependent increase in LTP, suggesting that dopamine receptor agonism activates cAMP-dependent intracellular pathways. We propose that MDMA exerts its LTP-altering effect involving a polysynaptic interaction between serotonergic and dopaminergic systems in hippocampal synapses. Our results are compatible with the view that the alterations in hippocampal LTP could be responsible for MDMA-dependent cognitive deficits observed in humans and animals.

  5. Adolescent mice show anxiety- and aggressive-like behavior and the reduction of long-term potentiation in mossy fiber-CA3 synapses after neonatal maternal separation.

    Science.gov (United States)

    Shin, S Y; Han, S H; Woo, R-S; Jang, S H; Min, S S

    2016-03-01

    Exposure to maternal separation (MS) during early life is an identified risk factor for emotional disorders such as anxiety and depression later in life. This study investigated the effects of neonatal MS on the behavior and long-term potentiation (LTP) as well as basic synaptic transmission at hippocampal CA3-CA1 and mossy fiber (MF)-CA3 synapses in adolescent mice for 19days. When mice were adolescents, we measured depression, learning, memory, anxious and aggressive behavior using the forced swimming test (FST), Y-maze, Morris water maze (MWM), elevated plus maze (EPM), three consecutive days of the open field test, the social interaction test, the tube-dominance test and the resident-intruder test. The results showed that there was no difference in FST, Y-maze, and MWM performance. However, MS mice showed more anxiety-like behavior in the EPM test and aggressive-like behavior in the tube-dominance and resident-intruder tests. In addition, the magnitude of LTP and release probability in the MF-CA3 synapses was reduced in the MS group but not in the CA3-CA1 synapse. Our results indicate that early life stress due to MS may induce anxiety- and aggressive-like behavior during adolescence, and these effects are associated with synaptic plasticity at the hippocampal MF-CA3 synapses.

  6. Midazolam and propofol used alone or sequentially for long-term sedation in critically ill, mechanically ventilated patients: a prospective, randomized study

    Science.gov (United States)

    2014-01-01

    Introduction Midazolam and propofol used alone for long-term sedation are associated with adverse effects. Sequential use may reduce the adverse effects, and lead to faster recovery, earlier extubation and lower costs. This study evaluates the effects, safety, and cost of midazolam, propofol, and their sequential use for long-term sedation in critically ill mechanically ventilated patients. Methods A total of 135 patients who required mechanical ventilation for >3 days were randomly assigned to receive midazolam (group M), propofol (group P), or sequential use of both (group M-P). In group M-P, midazolam was switched to propofol until the patients passed the spontaneous breathing trial (SBT) safety screen. The primary endpoints included recovery time, extubation time and mechanical ventilation time. The secondary endpoints were pharmaceutical cost, total cost of ICU stay, and recollection to mechanical ventilation-related events. Results The incidence of agitation following cessation of sedation in group M-P was lower than group M (19.4% versus 48.7%, P = 0.01). The mean percentage of adequate sedation and duration of sedation were similar in the three groups. The recovery time, extubation time and mechanical ventilation time of group M were 58.0 (interquartile range (IQR), 39.0) hours, 45.0 (IQR, 24.5) hours, and 192.0 (IQR, 124.0) hours, respectively; these were significantly longer than the other groups, while they were similar between the other two groups. In the treatment-received analysis, ICU duration was longer in group M than group M-P (P = 0.016). Using an intention-to-treat analysis and a treatment-received analysis, respectively, the pharmaceutical cost of group M-P was lower than group P (P 0.05). The incidence of hypotension in group M-P was lower than group (P = 0.01). Conclusion Sequential use of midazolam and propofol was a safe and effective sedation protocol, with higher clinical effectiveness and better cost-benefit ratio than

  7. Reconstructing the Migratory Behavior and Long-Term Survivorship of Juvenile Chinook Salmon under Contrasting Hydrologic Regimes.

    Directory of Open Access Journals (Sweden)

    Anna M Sturrock

    Full Text Available The loss of genetic and life history diversity has been documented across many taxonomic groups, and is considered a leading cause of increased extinction risk. Juvenile salmon leave their natal rivers at different sizes, ages and times of the year, and it is thought that this life history variation contributes to their population sustainability, and is thus central to many recovery efforts. However, in order to preserve and restore diversity in life history traits, it is necessary to first understand how environmental factors affect their expression and success. We used otolith (87Sr/(86Sr in adult Chinook salmon (Oncorhynchus tshawytcha returning to the Stanislaus River in the California Central Valley (USA to reconstruct the sizes at which they outmigrated as juveniles in a wetter (2000 and drier (2003 year. We compared rotary screw trap-derived estimates of outmigrant timing, abundance and size with those reconstructed in the adults from the same cohort. This allowed us to estimate the relative survival and contribution of migratory phenotypes (fry, parr, smolts to the adult spawning population under different flow regimes. Juvenile abundance and outmigration behavior varied with hydroclimatic regime, while downstream survival appeared to be driven by size- and time-selective mortality. Although fry survival is generally assumed to be negligible in this system, >20% of the adult spawners from outmigration year 2000 had outmigrated as fry. In both years, all three phenotypes contributed to the spawning population, however their relative proportions differed, reflecting greater fry contributions in the wetter year (23% vs. 10% and greater smolt contributions in the drier year (13% vs. 44%. These data demonstrate that the expression and success of migratory phenotypes vary with hydrologic regime, emphasizing the importance of maintaining diversity in a changing climate.

  8. Long-Term Collections

    CERN Multimedia

    Staff Association

    2016-01-01

    45 years helping in developing countries! CERN personnel have been helping the least fortunate people on the planet since 1971. How? With the Long-Term Collections! Dear Colleagues, The Staff Association’s Long-Term Collections (LTC) Committee is delighted to share this important milestone in the life of our Laboratory with you. Indeed, whilst the name of CERN is known worldwide for scientific discoveries, it also shines in the many humanitarian projects which have been supported by the LTC since 1971. Several schools and clinics, far and wide, carry its logo... Over the past 45 years, 74 projects have been supported (9 of which are still ongoing). This all came from a group of colleagues who wanted to share a little of what life offered them here at CERN, in this haven of mutual understanding, peace and security, with those who were less fortunate elsewhere. Thus, the LTC were born... Since then, we have worked as a team to maintain the dream of these visionaries, with the help of regular donat...

  9. Long-Term Collection

    CERN Document Server

    Staff Association

    2016-01-01

    Dear Colleagues, As previously announced in Echo (No. 254), your delegates took action to draw attention to the projects of the Long-Term Collections (LTC), the humanitarian body of the CERN Staff Association. On Tuesday, 11 October, at noon, small Z-Cards were widely distributed at the entrances of CERN restaurants and we thank you all for your interest. We hope to have achieved an important part of our goal, which was to inform you, convince you and find new supporters among you. We will find out in the next few days! An exhibition of the LTC was also set up in the Main Building for the entire week. The Staff Association wants to celebrate the occasion of the Long-Term Collection’s 45th anniversary at CERN because, ever since 1971, CERN personnel have showed great support in helping the least fortunate people on the planet in a variety of ways according to their needs. On a regular basis, joint fundraising appeals are made with the Directorate to help the victims of natural disasters around th...

  10. Collectes à long terme

    CERN Document Server

    Collectes à long terme

    2014-01-01

    En cette fin d’année 2014 qui approche à grands pas, le Comité des Collectes à Long Terme remercie chaleureusement ses fidèles donatrices et donateurs réguliers pour leurs contributions à nos actions en faveur des plus démunis de notre planète. C’est très important, pour notre Comité, de pouvoir compter sur l’appui assidu que vous nous apportez. Depuis plus de 40 ans maintenant, le modèle des CLT est basé principalement sur des actions à long terme (soit une aide pendant 4-5 ans par projet, mais plus parfois selon les circonstances), et sa planification demande une grande régularité de ses soutiens financiers. Grand MERCI à vous ! D’autres dons nous parviennent au cours de l’année, et ils sont aussi les bienvenus. En particulier, nous tenons à remercier...

  11. New experimental data reveal possible relation of chaotic behavior of the long-term geoelectric potential difference to seismic activity in Western Greece

    Energy Technology Data Exchange (ETDEWEB)

    Ifantis, Apostolos [Control Systems and Signals Laboratory, Department of Electrical Engineering, Technological Educational Institute of Patras, Patras 26334 (Greece) and Seismological Laboratory, Department of Geology, University of Patras, Patras 26500 (Greece)]. E-mail: ifantisa@teipat.gr; Giannakopoulos, Konstantine [Electronics Laboratory, Department of Physics, University of Patras, Patras 26500 (Greece)]. E-mail: kgian1@physics.upatras.gr

    2007-11-15

    In this paper, observations of the long-term geoelectric potential difference are presented based on data collected during a six-year (1998-2003) investigating period. Moreover, this paper constitutes a continuation of a previously published work with five-year (1993-1997) experimental data. For data logging purposes, an automatic system for collection of geoelectric measurements operates at the Seismological Laboratory of the University of Patras. The analysis of these data using Lyapunov exponents and Takens estimator confirm their quite chaotic behavior. The Lyapunov exponents have also been calculated for short periods of fifteen days, ten days before and five days after the earthquakes occurred during this six-year period. By thorough examination of the resulting Lyapunov spectrums, it seems that these are subject to possible changes prior to an earthquake.

  12. Enteric Neuronal Damage, Intramuscular Denervation and Smooth Muscle Phenotype Changes as Mechanisms of Chagasic Megacolon: Evidence from a Long-Term Murine Model of Tripanosoma cruzi Infection.

    Directory of Open Access Journals (Sweden)

    Camila França Campos

    hypothesize that the long-term inflammatory process mediates neuronal damage and intramuscular and intramural denervation, leading to phenotypic changes in smooth muscle cells associated with fibrosis. These long-term structural changes may represent the basic mechanism for the formation of the Chagasic megacolon.

  13. Enteric Neuronal Damage, Intramuscular Denervation and Smooth Muscle Phenotype Changes as Mechanisms of Chagasic Megacolon: Evidence from a Long-Term Murine Model of Tripanosoma cruzi Infection

    Science.gov (United States)

    Duz, Ana Luiza Cassin; Cartelle, Christiane Teixeira; Noviello, Maria de Lourdes; Veloso, Vanja Maria; Bahia, Maria Terezinha; Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

    2016-01-01

    inflammatory process mediates neuronal damage and intramuscular and intramural denervation, leading to phenotypic changes in smooth muscle cells associated with fibrosis. These long-term structural changes may represent the basic mechanism for the formation of the Chagasic megacolon. PMID:27045678

  14. Long-term omega-3 supplementation modulates behavior, hippocampal fatty acid concentration, neuronal progenitor proliferation and central TNF-α expression in 7 month old unchallenged mice.

    Science.gov (United States)

    Grundy, Trent; Toben, Catherine; Jaehne, Emily J; Corrigan, Frances; Baune, Bernhard T

    2014-01-01

    Dietary polyunsaturated fatty acid (PUFA) manipulation is being investigated as a potential therapeutic supplement to reduce the risk of developing age-related cognitive decline (ARCD). Animal studies suggest that high omega (Ω)-3 and low Ω-6 dietary content reduces cognitive decline by decreasing central nervous system (CNS) inflammation and modifying neuroimmune activity. However, no previous studies have investigated the long term effects of Ω-3 and Ω-6 dietary levels in healthy aging mice leaving the important question about the preventive effects of Ω-3 and Ω-6 on behavior and underlying molecular pathways unaddressed. We aimed to investigate the efficacy of long-term Ω-3 and Ω-6 PUFA dietary supplementation in mature adult C57BL/6 mice. We measured the effect of low, medium, and high Ω-3:Ω-6 dietary ratio, given from the age of 3-7 months, on anxiety and cognition-like behavior, hippocampal tissue expression of TNF-α, markers of neuronal progenitor proliferation and gliogenesis and serum cytokine concentration. Our results show that a higher Ω-3:Ω-6 PUFA diet ratio increased hippocampal PUFA, increased anxiety, improved hippocampal dependent spatial memory and reduced hippocampal TNF-α levels compared to a low Ω-3:Ω-6 diet. Furthermore, serum TNF-α concentration was reduced in the higher Ω-3:Ω-6 PUFA ratio supplementation group while expression of the neuronal progenitor proliferation markers KI67 and doublecortin (DCX) was increased in the dentate gyrus as opposed to the low Ω-3:Ω-6 group. Conversely, Ω-3:Ω-6 dietary PUFA ratio had no significant effect on astrocyte or microglia number or cell death in the dentate gyrus. These results suggest that supplementation of PUFAs may delay aging effects on cognitive function in unchallenged mature adult C57BL/6 mice. This effect is possibly induced by increasing neuronal progenitor proliferation and reducing TNF-α.

  15. Long-term omega-3 supplementation modulates behavior, hippocampal fatty acid concentration, neuronal progenitor proliferation and central TNF-α expression in 7 month old unchallenged mice

    Directory of Open Access Journals (Sweden)

    Trent eGrundy

    2014-11-01

    Full Text Available Dietary polyunsaturated fatty acid (PUFA manipulation is being investigated as a potential therapeutic supplement to reduce the risk of developing age-related cognitive decline (ARCD. Animal studies suggest that high omega (Ω-3 and low Ω-6 dietary content reduces cognitive decline by decreasing central nervous system (CNS inflammation and modifying neuroimmune activity. However, no previous studies have investigated the long term effects of Ω-3 and Ω-6 dietary levels in healthy aging mice leaving the important question about the preventive effects of Ω-3 and Ω-6 on behavior and underlying molecular pathways unaddressed. We aimed to investigate the efficacy of long-term Ω-3 and Ω-6 PUFA dietary supplementation in mature adult C57BL/6 mice. We measured the effect of low, medium and high Ω-3:Ω-6 dietary ratio, given from the age of 3 to 7 months, on anxiety and cognition-like behavior, hippocampal tissue expression of TNF-α, markers of neuronal progenitor proliferation and gliogenesis and serum cytokine concentration. Our results show that a higher Ω-3:Ω-6 PUFA diet ratio increased hippocampal PUFA, increased anxiety, improved hippocampal dependent spatial memory and reduced hippocampal TNF-α levels compared to a low Ω-3:Ω-6 diet. Furthermore, serum TNF-α concentration was reduced in the higher Ω-3:Ω-6 PUFA ratio supplementation group while expression of the neuronal progenitor proliferation markers KI67 and doublecortin (DCX was increased in the dentate gyrus as opposed to the low Ω-3:Ω-6 group. Conversely, Ω-3:Ω-6 dietary PUFA ratio had no significant effect on astrocyte or microglia number or cell death in the dentate gyrus. These results suggest that supplementation of PUFAs may delay ageing effects on cognitive function in unchallenged mature adult C57BL/6 mice. This effect is possibly induced by increasing neuronal progenitor proliferation and reducing TNF-α.

  16. Randomized controlled clinical trial of long-term chemo-mechanical caries removal using PapacarieTM gel

    Directory of Open Access Journals (Sweden)

    Lara Jansiski MOTTA

    2014-07-01

    Full Text Available Objectives: Compare the effectiveness of PapacarieTM gel for the chemo-mechanical removal of carious lesions on primary teeth to conventional caries removal with a low-speed bur with regard to execution time, clinical aspects and radiographic findings. Material and Methods: A randomized controlled clinical trial with a split-mouth design was carried out. The sample was composed of 20 children aged four to seven years, in whom 40 deciduous teeth were randomly divided into two groups: chemo-mechanical caries removal with PapacarieTM and removal of carious dentin with a low-speed bur. Each child underwent both procedures and served as his/her own control. Restorations were performed with glass ionomer cement. The time required to perform the procedure was also analyzed. The patients underwent longitudinal clinical and radiographic follow-up of the restorations. Results: No statistically significant difference between groups was found regarding the time required to perform the procedures and the radiographic follow up. Statistically significant differences between groups were found in the clinical evaluation at 6 and 18 months after treatment. Conclusion: PapacarieTM is as effective as the traditional method for the removal of carious dentin on deciduous teeth, but offers the advantages of the preservation of sound dental tissue as well as the avoidance of sharp rotary instruments and local anesthesia.

  17. Effect of short-time external short circuiting on the capacity fading mechanism during long-term cycling of LiCoO2/mesocarbon microbeads battery

    Science.gov (United States)

    Zhang, Lingling; Cheng, Xinqun; Ma, Yulin; Guan, Ting; Sun, Shun; Cui, Yingzhi; Du, Chunyu; Zuo, Pengjian; Gao, Yunzhi; Yin, Geping

    2016-06-01

    Commercial LiCoO2/mesocarbon microbeads (MCMB) batteries (CP475148AR) are short circuited by different contact resistances (0.6 mΩ and 5.0 mΩ) for short times. The short circuited battery is cycled for 1000 times, and the effect of the short-time external short circuiting on the capacity fading mechanism during long-term cycling of LiCoO2/MCMB battery is studied by analyzing the morphology, structure, and electrochemical performance. The results of SEM indicates that the morphology of LiCoO2 material is almost unchanged, except that the particle surface becomes smooth, and the solid electrolyte interphase (SEI) film on the surface of MCMB electrode becomes nonuniform due to the high temperature caused by short circuiting. The lithium ions are more difficult to de-intercalate from the anode and the lattice structure of LiCoO2 degrades according to the results of X-ray diffraction (XRD). The high discharge current caused by short circuiting can damage electrodes, leaving vacancies in structure. The damage of electrode structure can lead to a decrease of diffusion coefficient of lithium (D), so polarization increases and mainly caused by the LiCoO2 electrode. The capacity deterioration of short circuited battery during long-term cycling is mainly caused by the increase of polarization and capacity loss of electrodes.

  18. Microcystin release and Microcystis cell damage mechanism by alum treatment with long-term and large dose as in-lake treatment.

    Science.gov (United States)

    Han, Jisun; Jeon, Bong-Seok; Park, Ho-Dong

    2016-01-01

    Most of our previous studies reported aluminum causes no cell damage or lysis, and no subsequent toxin release in conventional treatment of drinking water or in the laboratory, on the contrary, we investigated the effect of long-term and large-dose alum treatment, because the environmental conditions in lakes and treatment plants are widely different. The microcosm experiments were designed to simulate the effect of adding alum under the similar conditions of common lakes and reservoirs, and the bottle experiments were conducted to examine the budget or dynamics of microcystin after adding alum. In precipitate analyses, we also confirm the release and dynamics of microcystin and the damage mechanisms of Microcystis cells under alum treatment. In microcosms treated with alum alone, the extracellular microcystin-LR (MC-LR) concentration increased to approximately 82% in 7 days. Similar results were obtained in bottle experiments. By plotting the concentration of released microcystin over time, we inferred that the extracellular MC-LR concentration exponentially rose toward an asymptotic maximum. Moreover, in scanning electron microscope images, some cells exhibited torn membranes with miniscule traces of aluminum hydroxide coating. We conclude that alum treatment, particularly at maximum dosage administered over long periods, seriously damages Microcystis cells and induces microcystin release. Therefore, long-term application of large alum doses is not recommended as an in-lake treatment.

  19. Analysis of long-term mechanical grooming on large-scale test panels coated with an antifouling and a fouling-release coating.

    Science.gov (United States)

    Hearin, John; Hunsucker, Kelli Z; Swain, Geoffrey; Stephens, Abraham; Gardner, Harrison; Lieberman, Kody; Harper, Michael

    2015-01-01

    Long-term grooming tests were conducted on two large-scale test panels, one coated with a fluorosilicone fouling-release (FR) coating, and one coated with a copper based ablative antifouling (AF) coating. Mechanical grooming was performed weekly or bi-weekly using a hand operated, electrically powered, rotating brush tool. The results indicate that weekly grooming was effective at removing loose or heavy biofilm settlement from both coatings, but could not prevent the permanent establishment of low-profile tenacious biofilms. Weekly grooming was very effective at preventing macrofouling establishment on the AF coating. The effectiveness of weekly grooming at preventing macrofouling establishment on the FR coating varied seasonally. The results suggest that frequent mechanical grooming is a viable method to reduce the fouling rating of ships' hulls with minimal impact to the coating. Frequent grooming could offer significant fuel savings while reducing hull cleaning frequencies and dry dock maintenance requirements.

  20. Lamb wave characterization of the effects of long-term thermal-mechanical aging on composite stiffness

    Science.gov (United States)

    Seale, M. D.; Madaras, E. I.

    1999-01-01

    Lamb waves offer a promising method of evaluating damage in composite materials. The Lamb wave velocity is directly related to the material parameters, so an effective tool exists to monitor damage in composites by measuring the velocity of these waves. The Lamb Wave Imager (LWI) uses a pulse/receive technique that excites an antisymmetric Lamb mode and measures the time-of-flight over a wide frequency range. Given the material density and plate thickness, the bending and out-of-plane shear stiffnesses are calculated from a reconstruction of the dispersion curve. In this study, the time-of-flight as well as the elastic stiffnesses D11, D22, A44, and A55 for composite samples which have undergone combined thermal and mechanical aging are obtained. The samples examined include a baseline specimen with 0 cycles, specimens which have been aged 2350 and 3530 cycles at high strain levels, and one specimen aged 3530 cycles at low strain levels.

  1. New Insights in the Long-Term Atmospheric Corrosion Mechanisms of Low Alloy Steel Reinforcements of Cultural Heritage Buildings.

    Science.gov (United States)

    Bouchar, Marie; Dillmann, Philippe; Neff, Delphine

    2017-06-19

    Reinforcing clamps made of low alloy steel from the Metz cathedral and corroded outdoors during 500 years were studied by OM, FESEM/EDS, and micro-Raman spectroscopy. The corrosion product layer is constituted of a dual structure. The outer layer is mainly constituted of goethite and lepidocrocite embedding exogenous elements such as Ca and P. The inner layer is mainly constituted of ferrihydrite. The behaviour of the inner layer under conditions simulating the wetting stage of the RH wet/dry atmospheric corrosion cycle was observed by in situ micro-Raman spectroscopy. The disappearance of ferrihydrite near the metal/oxide interface strongly suggests a mechanism of reductive dissolution caused by the oxidation of the metallic substrate and was observed for the first time in situ on an archaeological system.

  2. Renal Effects and Underlying Molecular Mechanisms of Long-Term Salt Content Diets in Spontaneously Hypertensive Rats

    Science.gov (United States)

    Berger, Rebeca Caldeira Machado; Vassallo, Paula Frizera; Crajoinas, Renato de Oliveira; Oliveira, Marilene Luzia; Martins, Flávia Letícia; Nogueira, Breno Valentim; Motta-Santos, Daisy; Araújo, Isabella Binotti; Forechi, Ludimila; Girardi, Adriana Castello Costa; Santos, Robson Augusto Souza; Mill, José Geraldo

    2015-01-01

    Several evidences have shown that salt excess is an important determinant of cardiovascular and renal derangement in hypertension. The present study aimed to investigate the renal effects of chronic high or low salt intake in the context of hypertension and to elucidate the molecular mechanisms underlying such effects. To this end, newly weaned male SHR were fed with diets only differing in NaCl content: normal salt (NS: 0.3%), low salt (LS: 0.03%), and high salt diet (HS: 3%) until 7 months of age. Analysis of renal function, morphology, and evaluation of the expression of the main molecular components involved in the renal handling of albumin, including podocyte slit-diaphragm proteins and proximal tubule endocytic receptors were performed. The relationship between diets and the balance of the renal angiotensin-converting enzyme (ACE) and ACE2 enzymes was also examined. HS produced glomerular hypertrophy and decreased ACE2 and nephrin expressions, loss of morphological integrity of the podocyte processes, and increased proteinuria, characterized by loss of albumin and high molecular weight proteins. Conversely, severe hypertension was attenuated and renal dysfunction was prevented by LS since proteinuria was much lower than in the NS SHRs. This was associated with a decrease in kidney ACE/ACE2 protein and activity ratio and increased cubilin renal expression. Taken together, these results suggest that LS attenuates hypertension progression in SHRs and preserves renal function. The mechanisms partially explaining these findings include modulation of the intrarenal ACE/ACE2 balance and the increased cubilin expression. Importantly, HS worsens hypertensive kidney injury and decreases the expression nephrin, a key component of the slit diaphragm. PMID:26495970

  3. Renal Effects and Underlying Molecular Mechanisms of Long-Term Salt Content Diets in Spontaneously Hypertensive Rats.

    Directory of Open Access Journals (Sweden)

    Rebeca Caldeira Machado Berger

    Full Text Available Several evidences have shown that salt excess is an important determinant of cardiovascular and renal derangement in hypertension. The present study aimed to investigate the renal effects of chronic high or low salt intake in the context of hypertension and to elucidate the molecular mechanisms underlying such effects. To this end, newly weaned male SHR were fed with diets only differing in NaCl content: normal salt (NS: 0.3%, low salt (LS: 0.03%, and high salt diet (HS: 3% until 7 months of age. Analysis of renal function, morphology, and evaluation of the expression of the main molecular components involved in the renal handling of albumin, including podocyte slit-diaphragm proteins and proximal tubule endocytic receptors were performed. The relationship between diets and the balance of the renal angiotensin-converting enzyme (ACE and ACE2 enzymes was also examined. HS produced glomerular hypertrophy and decreased ACE2 and nephrin expressions, loss of morphological integrity of the podocyte processes, and increased proteinuria, characterized by loss of albumin and high molecular weight proteins. Conversely, severe hypertension was attenuated and renal dysfunction was prevented by LS since proteinuria was much lower than in the NS SHRs. This was associated with a decrease in kidney ACE/ACE2 protein and activity ratio and increased cubilin renal expression. Taken together, these results suggest that LS attenuates hypertension progression in SHRs and preserves renal function. The mechanisms partially explaining these findings include modulation of the intrarenal ACE/ACE2 balance and the increased cubilin expression. Importantly, HS worsens hypertensive kidney injury and decreases the expression nephrin, a key component of the slit diaphragm.

  4. Microbial Carbon Pump ---A New Mechanism for Long-Term Carbon Storage in the Global Ocean (Invited)

    Science.gov (United States)

    Jiao, N.; Azam, F.; McP Working Group; Scor Wg134

    2010-12-01

    Marine dissolved organic matter (DOM) reservoir, containing carbon equivalent to the total carbon inventory of atmospheric CO2, is an important issue in understanding the role of the ocean in climate change. The known biological mechanism for oceanic carbon sequestration is the biological pump, which depends on vertical transportation of carbon either through particulate organic matter (POM) sedimentation or DOM export by mixing and downwelling. Both the POM and the DOM are subject to microbial mineralization and most of the organic carbon will be returned to dissolved inorganic carbon within a few decades. Only a small fraction of the POM escapes mineralization and reaches the sediment where organic carbon can be buried and stored for thousands and even millions of years. The efficiency of the biological pump is currently the basic measure of the ocean’s ability to store biologically fixed carbon. However, the production and fate of the large pool of recalcitrant DOM with an averaged turnover time of 4000-6000 thousands of years in the water column has not been adequately considered to date. Marine microbes essentially monopolize the utilization of DOM. Although their diverse adaptive strategies for using newly fixed carbon are well known, major gaps exist in our knowledge on how they interact with the large pool of DOM that appears to be recalcitrant. This is an important problem, as DOM molecules that are not degraded for extended periods of time constitute carbon storage in the ocean. A newly proposed concept - the “microbial carbon pump (MCP)” (NATURE REVIEWS Microbiology 2010.8:593-599) (also see diagram below) provides a formalized focus on the significance of microbial processes in carbon storage in the recalcitrant DOM reservoir, and a framework for testing hypotheses on the sources and sinks of DOM and the underlying biogeochemical mechanisms. The MCP, through concessive processing of DOM, transforms some organic carbon from the reactive DOM pools

  5. Long-term changes in brain cholinergic system and behavior in rats following gestational exposure to lead: protective effect of calcium supplement

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    Basha Chand D.

    2015-12-01

    Full Text Available Our earlier studies showed that lactational exposure to lead (Pb caused irreversible neurochemical alterations in rats. The present study was carried out to examine whether gestational exposure to Pb can cause long-term changes in the brain cholinergic system and behavior of rats. The protective effect of calcium (Ca supplementation against Pb toxicity was also examined. Pregnant rats were exposed to 0.2% Pb (Pb acetate in drinking water from gestational day (GD 6 to GD 21. The results showed decrease in body weight gain (GD 6–21 of dams, whereas no changes were observed in offspring body weight at different postnatal days following Pb exposure. Male offspring treated with Pb showed marginal alterations in developmental landmarks such as unfolding of pinnae, lower and upper incisor eruption, fur development, eye slit formation and eye opening on postnatal day (PND 1, whereas significant alterations were found in the righting reflex (PNDs 4–7, slant board behavior (PNDs 8–10 and forelimb hang performance (PNDs 12–16. Biochemical analysis showed decrease in synaptosomal acetylcholinesterase (AChE activity and an increase in acetylcholine (ACh levels in the cortex, cerebellum and hippocampus on PND 14, PND 21, PND 28 and in the four-month age group of rats following Pb exposure. Significant deficits were also observed in total locomotor activity, exploratory behavior and open field behavior in selected age groups of Pb-exposed rats. These alterations were found to be maximal on PND 28, corresponding with the greater blood lead levels observed on PND 28. Addition of 0.02% Ca to Pb reversed the Pb-induced impairments in the cholinergic system as well as in behavioral parameters of rats. In conclusion, these data suggest that gestational exposure to Pb is able to induce long-term changes in neurological functions of offspring. Maternal Ca administration reversed these neurological effects of Pb later in life, suggesting a protective effect of

  6. A mechanical microconnector system for restoration of tissue continuity and long-term drug application into the injured spinal cord.

    Science.gov (United States)

    Brazda, Nicole; Voss, Christian; Estrada, Veronica; Lodin, Homaira; Weinrich, Nils; Seide, Klaus; Müller, Jörg; Müller, Hans W

    2013-12-01

    Complete transection of the spinal cord leaves a gap of several mm which fills with fibrous scar tissue. Several approaches in rodent models have used tubes, foams, matrices or tissue implants to bridge this gap. Here, we describe a mechanical microconnector system (mMS) to re-adjust the retracted spinal cord stumps. The mMS is a multi-channel system of polymethylmethacrylate (PMMA), designed to fit into the spinal cord tissue gap after transection, with an outlet tubing system to apply negative pressure to the mMS thus sucking the spinal cord stumps into the honeycomb-structured holes. The stumps adhere to the microstructure of the mMS walls and remain in the mMS after removal of the vacuum. We show that the mMS preserves tissue integrity and allows axonal regrowth at 2, 5 and 19 weeks post lesion with no adverse tissue effects like in-bleeding or cyst formation. Preliminary assessment of locomotor function in the open field suggested beneficial effects of the mMS. Additional inner micro-channels enable local substance delivery into the lesion center via an attached osmotic minipump. We suggest that the mMS is a suitable device to adapt and stabilize the injured spinal cord after surgical resection of scar tissue (e.g., for chronic patients) or traumatic injuries with large tissue and bone damages.

  7. Toxic organic micro-pollutants removal mechanisms in long-term operated membrane bioreactor treating municipal solid waste leachate.

    Science.gov (United States)

    Boonyaroj, Varinthorn; Chiemchaisri, Chart; Chiemchaisri, Wilai; Theepharaksapan, Suthida; Yamamoto, Kazuo

    2012-06-01

    The performance of two-stage membrane bioreactor (MBR) in term of toxic organic micro-pollutants removal was continuously monitored for 300 days under long sludge age condition. The phenolic compounds and phthalic acid esters (PAEs) in landfill leachate and treated water from MBR unit were quantified by solid phase extraction and gas chromatography-mass spectrometry. Priority pollutants in landfill leachate were phenolics and their degradation products i.e. 4-methyl-2,6-di-tert-butylphenol, bisphenol A at higher concentrations above 100 μg/l, PAEs i.e. dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, and di (2-ethylhexyl) phthalate. It was found that MBR could remove phenolic compounds and PAEs by 77-96%. Biodegradation and adsorption mechanisms were responsible for their removals in MBR. Additionally, the retention of compounds during filtration through the fouled membrane was also found significant. This research shows that the removal of organic micro-pollutants in landfill leachate was improved under higher biomass concentration and longer sludge age conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. [Early and long term results of mechanical aortic valve replacement at the Instituto Nacional del Torax in Chile].

    Science.gov (United States)

    Villavicencio, Mauricio; Turner, Eduardo; Naranjo, Lorenzo

    2005-10-01

    Mechanical aortic valve replacement (AVR) results have been published extensively in industrialized countries. To assess our immediate and late results in patients subjected to AVR. We retrospectively studied 194 patients subjected to isolated AVR between 1995 and 2003. Mean age was 57 +/- 13 years and 119 (61%) were male. One hundred thirty nine (73%) were in functional class III-IV, 20 (10%) had a previous cardiac operation and 25 (13%) were operated as an emergency. Surgical indication was stenosis in 110 (58%), regurgitation in 49 (26%) and stenosis/regurgitation in 31 (16%). Etiology was bicuspid valve 56 (29%), degenerative lesions 55 (28%), rheumatic valve disease 38 (20%) and endocarditis 27 (14%). Medtronic Hall was the most common prosthesis used in 157 patients (81%). Mean cardiopulmonary bypass time 97 +/- 29 min and mean cross clamp time was 69 +/- 21 min. Operative mortality was 4.6% (3% in elective surgery, 16% in emergency surgery and 0% in reoperations). Follow-up was complete in 100% of cases, totalizing 636 patients-year. Survival was 91 +/- 2%, 80 +/- 4% and 73 +/- 6%, at 1, 5 and 7 years, respectively. Multivariate risk analysis identified renal failure and endocarditis as predictors of early and late mortality. During follow up, the linear incidence rate for hemorrhage was 3.29% /patients-year, thromboembolism 2.04% patients-year and endocarditis 1.1% patients-year. AVR has low overall and elective mortality. Midterm survival is good but linear event rates related to anticoagulant treatment are higher than those previously published in industrialized countries. Renal failure and endocarditis were risk factors for early and late death.

  9. Long term ex vivo culturing of Drosophila brain as a method to live image pupal brains: insights into the cellular mechanisms of neuronal remodeling.

    Science.gov (United States)

    Rabinovich, Dana; Mayseless, Oded; Schuldiner, Oren

    2015-01-01

    Holometabolous insects, including Drosophila melanogaster, undergo complete metamorphosis that includes a pupal stage. During metamorphosis, the Drosophila nervous system undergoes massive remodeling and growth, that include cell death and large-scale axon and synapse elimination as well as neurogenesis, developmental axon regrowth, and formation of new connections. Neuronal remodeling is an essential step in the development of vertebrate and invertebrate nervous systems. Research on the stereotypic remodeling of Drosophila mushroom body (MB) γ neurons has contributed to our knowledge of the molecular mechanisms of remodeling but our knowledge of the cellular mechanisms remain poorly understood. A major hurdle in understanding various dynamic processes that occur during metamorphosis is the lack of time-lapse resolution. The pupal case and opaque fat bodies that enwrap the central nervous system (CNS) make live-imaging of the central brain in-vivo impossible. We have established an ex vivo long-term brain culture system that supports the development and neuronal remodeling of pupal brains. By optimizing culture conditions and dissection protocols, we have observed development in culture at kinetics similar to what occurs in vivo. Using this new method, we have obtained the first time-lapse sequence of MB γ neurons undergoing remodeling in up to a single cell resolution. We found that axon pruning is initiated by blebbing, followed by one-two nicks that seem to initiate a more widely spread axon fragmentation. As such, we have set up some of the tools and methodologies needed for further exploration of the cellular mechanisms of neuronal remodeling, not limited to the MB. The long-term ex vivo brain culture system that we report here could be used to study dynamic aspects of neurodevelopment of any Drosophila neuron.

  10. Mechanical support with venoarterial extracorporeal membrane oxygenation (ECMO-VA): Short-term and long-term prognosis after a successful weaning.

    Science.gov (United States)

    García-Gigorro, R; Renes-Carreño, E; Pérez-Vela, J L; Marín-Mateos, H; Gutiérrez, J; Corrés-Peiretti, M A; Delgado, J F; Pérez-de la Sota, E; Cortina-Romero, J M; Montejo-González, J C

    2017-03-02

    Extracorporeal membrane oxygenation (ECMO) affords mechanical circulatory assistance associated to high mortality. However, weaning from such mechanical support may not imply improved short- or long-term survival. This study describes the characteristics and evolution of patients with refractory cardiogenic shock (RCS) subjected to venoarterial ECMO (VA-ECMO) in a hospital with a heart transplant program. A single-center, retrospective cohort study was carried out. The cardiovascular ICU of a tertiary hospital. Forty-six patients consecutively subjected to VA-ECMO over 6 years. Hospital mortality after weaning from ECMO and overall survival (OS) were analyzed. Fifteen patients (33%) died with VA-ECMO and 31 (67%) were weaned after 8 days of support (IQR: 5-15). Fourteen patients under went transplantation. Hospital mortality in these patients was 32% (10/31), and was associated to age (P=.001), SAPS II score (P=.009), cannulation bleeding (P=.01) and post-acute myocardial infarction RCS (P=.001). After a median follow-up of 27 months (IQR: 11-49), 91% of the patients discharged from hospital were still alive. Overall survival after weaning from assistance was associated to the type of cardiac disease (P=.002). Patients with RCS after acute myocardial infarction had a poorer prognosis. In our experience, VA-ECMO can be used as mechanical assistance in the management of RCS. The technique is associated to high early mortality, though the long-term survival rate after hospital discharge is good. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  11. Early decrease in dietary protein:energy ratio by fat addition and ontogenetic changes in muscle growth mechanisms of rainbow trout: short- and long-term effects.

    Science.gov (United States)

    Alami-Durante, Hélène; Cluzeaud, Marianne; Duval, Carine; Maunas, Patrick; Girod-David, Virginia; Médale, Françoise

    2014-09-14

    As the understanding of the nutritional regulation of muscle growth mechanisms in fish is fragmentary, the present study aimed to (1) characterise ontogenetic changes in muscle growth-related genes in parallel to changes in muscle cellularity; (2) determine whether an early decrease in dietary protein:energy ratio by fat addition affects the muscle growth mechanisms of rainbow trout (Oncorhynchus mykiss) alevins; and (3) determine whether this early feeding of a high-fat (HF) diet to alevins had a long-term effect on muscle growth processes in juveniles fed a commercial diet. Developmental regulation of hyperplasia and hypertrophy was evidenced at the molecular (expression of myogenic regulatory factors, proliferating cell nuclear antigen and myosin heavy chains (MHC)) and cellular (number and diameter of white muscle fibres) levels. An early decrease in dietary protein:energy ratio by fat addition stimulated the body growth of alevins but led to a fatty phenotype, with accumulation of lipids in the anterior part, and less caudal muscle when compared at similar body weights, due to a decrease in both the white muscle hyperplasia and maximum hypertrophy of white muscle fibres. These HF diet-induced cellular changes were preceded by a very rapid down-regulation of the expression of fast-MHC. The present study also demonstrated that early dietary composition had a long-term effect on the subsequent muscle growth processes of juveniles fed a commercial diet for 3 months. When compared at similar body weights, initially HF diet-fed juveniles indeed had a lower mean diameter of white muscle fibres, a smaller number of large white muscle fibres, and lower expression levels of MyoD1 and myogenin. These findings demonstrated the strong effect of early feed composition on the muscle growth mechanisms of trout alevins and juveniles.

  12. Evaluation Effects of the Short- and Long-Term Freeze-Thaw Exposure on the Axial Behavior of Concrete-Filled Glass Fiber-Reinforced-Polymer Tubes

    Directory of Open Access Journals (Sweden)

    Hend El-Zefzafy

    2013-01-01

    Full Text Available Previous studies have demonstrated the high performance of the concrete-filled fiber-reinforced polymer (FRP tubes (CFFTs as a stay-in-place formwork and confining material for concrete structures. However, there are several concerns related to the behavior of CFFT as a protective jacket against harsh environmental effects. The environmental effects such as freeze-thaw cycles and deicing salt solutions may affect materials properties, which may affect the structural response of CFFT members as well. This paper presents the test results of experimental investigation on the durability of short- and long-term behaviors of CFFT members. Test variables included the effect of confining using GFRP tubes, freeze-thaw cycles exposure in salt water, and the number of freeze-thaw cycles. CFFT cylinders (150 × 300 mm were prepared and exposed to 100 and 300 freeze-thaw cycles in salt water condition. Then, pure axial compression tests were conducted in order to evaluate the performance of specimens due to freeze-thaw exposure, by comparing the stress-strain behavior and their ultimate load capacities. Test results indicated that the confinement using CFFT technique significantly protected the concrete when subjected to freeze-thaw exposure.

  13. Effects of long-term 50Hz power-line frequency electromagnetic field on cell behavior in Balb/c 3T3 cells.

    Science.gov (United States)

    An, Guang-Zhou; Xu, Hui; Zhou, Yan; Du, Le; Miao, Xia; Jiang, Da-Peng; Li, Kang-Chu; Guo, Guo-Zhen; Zhang, Chen; Ding, Gui-Rong

    2015-01-01

    Power-line frequency electromagnetic field (PF-EMF) was reported as a human carcinogen by some epidemiological research, but the conclusion is lack of robust experiment evidence. To identify the effects of long-term PF-EMF exposure on cell behavior, Balb/c 3T3 cells in exponential growth phase were exposed or sham-exposed to 50 Hertz (Hz) PF-EMF at 2.3 mT for 2 hours (h) one day, 5 days every week. After 11 weeks exposure, cells were collected instantly. Cell morphology was observed under invert microscope and Giemsa staining, cell viability was detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, cell cycle and apoptosis was examined by flow cytometry, the protein level of Proliferating Cell Nuclear Antigen (PCNA) and CyclinD1 was detected by western blot, cell transformation was examined by soft agar clone assay and plate clone forming test, and cell migration ability was observed by scratch adhesion test. It was found that after PF-EMF exposure, cell morphology, apoptosis, cell migration ability and cell transformation didn't change. However, compared with sham group, cell viability obviously decreased and cell cycle distribution also changed after 11 weeks PF-EMF exposure. Meanwhile, the protein level of PCNA and CyclinD1 significantly decreased after PF-EMF exposure. These data suggested that although long-term 50Hz PF-EMF exposure under this experimental condition had no effects on apoptosis, cell migration ability and cell transformation, it could affect cell proliferation and cell cycle by down-regulation the expression of PCNA and CyclinD1 protein.

  14. The Steady State Great Ape? Long Term Isotopic Records Reveal the Effects of Season, Social Rank and Reproductive Status on Bonobo Feeding Behavior

    Science.gov (United States)

    Oelze, Vicky M.; Douglas, Pamela Heidi; Stephens, Colleen R.; Surbeck, Martin; Behringer, Verena; Richards, Michael P.; Fruth, Barbara; Hohmann, Gottfried

    2016-01-01

    Dietary ecology of extant great apes is known to respond to environmental conditions such as climate and food availability, but also to vary depending on social status and life history characteristics. Bonobos (Pan paniscus) live under comparatively steady ecological conditions in the evergreen rainforests of the Congo Basin. Bonobos are an ideal species for investigating influences of sociodemographic and physiological factors, such as female reproductive status, on diet. We investigate the long term dietary pattern in wild but fully habituated bonobos by stable isotope analysis in hair and integrating a variety of long-term sociodemographic information obtained through observations. We analyzed carbon and nitrogen stable isotopes in 432 hair sections obtained from 101 non-invasively collected hair samples. These samples represented the dietary behavior of 23 adult bonobos from 2008 through 2010. By including isotope and crude protein data from plants we could establish an isotope baseline and interpret the results of several general linear mixed models using the predictors climate, sex, social rank, reproductive state of females, adult age and age of infants. We found that low canopy foliage is a useful isotopic tracer for tropical rainforest settings, and consumption of terrestrial herbs best explains the temporal isotope patterns we found in carbon isotope values of bonobo hair. Only the diet of male bonobos was affected by social rank, with lower nitrogen isotope values in low-ranking young males. Female isotope values mainly differed between different stages of reproduction (cycling, pregnancy, lactation). These isotopic differences appear to be related to changes in dietary preference during pregnancy (high protein diet) and lactation (high energy diet), which allow to compensate for different nutritional needs during maternal investment. PMID:27626279

  15. Effects of long-term 50Hz power-line frequency electromagnetic field on cell behavior in Balb/c 3T3 cells.

    Directory of Open Access Journals (Sweden)

    Guang-Zhou An

    Full Text Available Power-line frequency electromagnetic field (PF-EMF was reported as a human carcinogen by some epidemiological research, but the conclusion is lack of robust experiment evidence. To identify the effects of long-term PF-EMF exposure on cell behavior, Balb/c 3T3 cells in exponential growth phase were exposed or sham-exposed to 50 Hertz (Hz PF-EMF at 2.3 mT for 2 hours (h one day, 5 days every week. After 11 weeks exposure, cells were collected instantly. Cell morphology was observed under invert microscope and Giemsa staining, cell viability was detected by 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT assay, cell cycle and apoptosis was examined by flow cytometry, the protein level of Proliferating Cell Nuclear Antigen (PCNA and CyclinD1 was detected by western blot, cell transformation was examined by soft agar clone assay and plate clone forming test, and cell migration ability was observed by scratch adhesion test. It was found that after PF-EMF exposure, cell morphology, apoptosis, cell migration ability and cell transformation didn't change. However, compared with sham group, cell viability obviously decreased and cell cycle distribution also changed after 11 weeks PF-EMF exposure. Meanwhile, the protein level of PCNA and CyclinD1 significantly decreased after PF-EMF exposure. These data suggested that although long-term 50Hz PF-EMF exposure under this experimental condition had no effects on apoptosis, cell migration ability and cell transformation, it could affect cell proliferation and cell cycle by down-regulation the expression of PCNA and CyclinD1 protein.

  16. Lateral Variations of Interplate Coupling along the Mexican Subduction Interface: Relationships with Long-Term Morphology and Fault Zone Mechanical Properties

    Science.gov (United States)

    Rousset, Baptiste; Lasserre, Cécile; Cubas, Nadaya; Graham, Shannon; Radiguet, Mathilde; DeMets, Charles; Socquet, Anne; Campillo, Michel; Kostoglodov, Vladimir; Cabral-Cano, Enrique; Cotte, Nathalie; Walpersdorf, Andrea

    2015-12-01

    Although patterns of interseismic strain accumulation above subduction zones are now routinely characterised using geodetic measurements, their physical origin, persistency through time, and relationships to seismic hazard and long-term deformation are still debated. Here, we use GPS and morphological observations from southern Mexico to explore potential mechanical links between variations in inter-SSE (in between slow slip events) coupling along the Mexico subduction zone and the long-term topography of the coastal regions from Guerrero to Oaxaca. Inter-SSE coupling solutions for two different geometries of the subduction interface are derived from an inversion of continuous GPS time series corrected from slow slip events. They reveal strong along-strike variations in the shallow coupling (i.e. at depths down to 25 km), with high-coupling zones (coupling >0.7) alternating with low-coupling zones (coupling 0.7) and transitions to uncoupled, steady slip at a relatively uniform ˜ 175-km inland from the trench. Along-strike variations in the coast-to-trench distances are strongly correlated with the GPS-derived forearc coupling variations. To explore a mechanical explanation for this correlation, we apply Coulomb wedge theory, constrained by local topographic, bathymetric, and subducting-slab slopes. Critical state areas, i.e. areas where the inner subduction wedge deforms, are spatially correlated with transitions at shallow depth between uncoupled and coupled areas of the subduction interface. Two end-member models are considered to explain the correlation between coast-to-trench distances and along-strike variations in the inter-SSE coupling. The first postulates that the inter-SSE elastic strain is partitioned between slip along the subduction interface and homogeneous plastic permanent deformation of the upper plate. In the second, permanent plastic deformation is postulated to depend on frictional transitions along the subduction plate interface. Based on the

  17. Lateral Variations of Interplate Coupling along the Mexican Subduction Interface: Relationships with Long-Term Morphology and Fault Zone Mechanical Properties

    Science.gov (United States)

    Rousset, Baptiste; Lasserre, Cécile; Cubas, Nadaya; Graham, Shannon; Radiguet, Mathilde; DeMets, Charles; Socquet, Anne; Campillo, Michel; Kostoglodov, Vladimir; Cabral-Cano, Enrique; Cotte, Nathalie; Walpersdorf, Andrea

    2016-10-01

    Although patterns of interseismic strain accumulation above subduction zones are now routinely characterised using geodetic measurements, their physical origin, persistency through time, and relationships to seismic hazard and long-term deformation are still debated. Here, we use GPS and morphological observations from southern Mexico to explore potential mechanical links between variations in inter-SSE (in between slow slip events) coupling along the Mexico subduction zone and the long-term topography of the coastal regions from Guerrero to Oaxaca. Inter-SSE coupling solutions for two different geometries of the subduction interface are derived from an inversion of continuous GPS time series corrected from slow slip events. They reveal strong along-strike variations in the shallow coupling (i.e. at depths down to 25 km), with high-coupling zones (coupling >0.7) alternating with low-coupling zones (coupling 0.7) and transitions to uncoupled, steady slip at a relatively uniform ˜ 175-km inland from the trench. Along-strike variations in the coast-to-trench distances are strongly correlated with the GPS-derived forearc coupling variations. To explore a mechanical explanation for this correlation, we apply Coulomb wedge theory, constrained by local topographic, bathymetric, and subducting-slab slopes. Critical state areas, i.e. areas where the inner subduction wedge deforms, are spatially correlated with transitions at shallow depth between uncoupled and coupled areas of the subduction interface. Two end-member models are considered to explain the correlation between coast-to-trench distances and along-strike variations in the inter-SSE coupling. The first postulates that the inter-SSE elastic strain is partitioned between slip along the subduction interface and homogeneous plastic permanent deformation of the upper plate. In the second, permanent plastic deformation is postulated to depend on frictional transitions along the subduction plate interface. Based on the

  18. Interfacial, mechanical properties of Al{sub 2}O{sub 3}-NiAl composites respective to long term thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jia; Hu, Weiping; Gottstein, Guenter [RWTH Aachen Univ. (Germany). Inst. of Physical Metallurgy and Metal Physics

    2010-07-01

    The long term thermal stability of NiAl-Al{sub 2}O{sub 3} composites was investigated. During annealing of the composites at 973 K and 1373 K for 2000 hours, the NiAl-Al{sub 2}O{sub 3} system showed excellent chemical stability. However, grain growth and embrittlement progressed in the polycrystalline NiAl matrix. The interfacial shear strength decreased from 222{+-}50 MPa for the as-fabricated sample to 197{+-}48 MPa and 150{+-}38 MPa for the samples annealed at 973 K and 1373 K, respectively. The microstructure change during annealing at 973K and 1373 K affected the tensile strength differently. The potential causes of microstructure and interface structure change and their impact on mechanical properties are discussed. (orig.)

  19. Long-Term Behavioral Outcomes after a Randomized, Clinical Trial of Counselor-Assisted Problem Solving for Adolescents with Complicated Mild-to-Severe Traumatic Brain Injury.

    Science.gov (United States)

    Wade, Shari L; Taylor, H Gerry; Cassedy, Amy; Zhang, Nanhua; Kirkwood, Michael W; Brown, Tanya M; Stancin, Terry

    2015-07-01

    Family problem-solving therapy (FPST) has been shown to reduce behavior problems after pediatric traumatic brain injury (TBI). It is unclear whether treatment gains are maintained. We sought to evaluate the maintenance of improvements in behavior problems after a Web-based counselor-assisted FPST (CAPS) intervention compared to an Internet resource comparison (IRC) intervention provided to adolescents within the initial year post-TBI. We hypothesized that family socioeconomic status, child educational status, and baseline levels of symptoms would moderate the efficacy of the treatment over time. Participants included 132 adolescents ages 12-17 years who sustained a complicated mild-to-severe TBI 1-6 months before study enrollment. Primary outcomes were the Child Behavior Checklist Internalizing and Externalizing Totals. Mixed-models analyses, using random intercepts and slopes, were conducted to examine group differences over time. There was a significant group×time×grade interaction (F(1,304)=4.42; p=0.03) for internalizing problems, with high school-age participants in CAPS reporting significantly lower symptoms at 18 months postbaseline than those in the IRC. Post-hoc analyses to elucidate the nature of effects on internalizing problems revealed significant group×time×grade interactions for the anxious/depressed (p=0.03) and somatic complaints subscales (p=0.04). Results also indicated significant improvement over time for CAPS participants who reported elevated externalizing behavior problems at baseline (F(1, 310)=7.17; p=0.008). Findings suggest that CAPS may lead to long-term improvements in behavior problems among older adolescents and those with pretreatment symptoms.

  20. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media; Comprehension de l'alteration a long terme des colis de verre R7T7: etude du couplage chimie transport dans un milieu fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chomat, L

    2008-04-15

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH{>=}11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  1. Enhanced treatment for depression in primary care: long-term outcomes of a psycho-educational prevention program alone and enriched with psychiatric consultation or cognitive behavioral therapy

    NARCIS (Netherlands)

    Conradi, H.J; De Jonge, P.; Kluiter, H; Smit, A.; Van Der Meer, K.; Jenner, J.A; van Os, T.W.D.P.; Emmelkamp, P.M G; Ormel, J.

    2007-01-01

    Background. The long-term outcome of major depression is often unfavorable, and because most cases of depression are managed by general practitioners (GPs), this places stress on the need to improve treatment in primary care. This study evaluated the long-term effects of enhancing the GP's usual

  2. LONG TERM COLLECTIONS

    CERN Multimedia

    STAFF ASSOCIATION

    2010-01-01

    ACKNOWLEDGMENTS The Long-Term Collections (CLT) committee would like to warmly thank its faithful donors who, year after year, support our actions all over the world. Without you, all this would not be possible. We would like to thank, in particular, the CERN Firemen’s Association who donated 5000 CHF in the spring thanks to the sale of their traditional calendar, and the generosity of the CERN community. A huge thank you to the firemen for their devotion to our cause. And thank you to all those who have opened their door, their heart, and their purses! Similarly, we warmly thank the CERN Yoga Club once again for its wonderful donation of 2000 CHF we recently received. We would also like to tell you that all our projects are running well. Just to remind you, we are currently supporting the activities of the «Réflexe-Partage» Association in Mali; the training centre of «Education et Développement» in Abomey, Benin; and the orphanage and ...

  3. Anticipating Long-Term Stock Market Volatility

    OpenAIRE

    Conrad, Christian; Loch, Karin

    2012-01-01

    We investigate the relationship between long-term U.S. stock market risks and the macroeconomic environment using a two component GARCH-MIDAS model. Our results provide strong evidence in favor of counter-cyclical behavior of long-term stock market volatility. Among the various macro variables in our dataset the term spread, housing starts, corporate profits and the unemployment rate have the highest predictive ability for stock market volatility . While the term spread and housing starts are...

  4. Imbalance between pro and anti-oxidant mechanisms in perivascular adipose tissue aggravates long-term high-fat diet-derived endothelial dysfunction.

    Directory of Open Access Journals (Sweden)

    Marta Gil-Ortega

    Full Text Available BACKGROUND: The hypothesis of this study is that long-term high-fat diets (HFD induce perivascular adipose tissue (PVAT dysfunction characterized by a redox imbalance, which might contribute to aggravate endothelial dysfunction in obesity. METHODS AND RESULTS: C57BL/6J mice were fed either control or HFD (45% kcal from fat for 32 weeks. Body weight, lumbar and mesenteric adipose tissue weights were significantly higher in HFD animals compared to controls. The anticontractile effect of PVAT in mesenteric arteries (MA was lost after 32 week HFD and mesenteric endothelial-dependent relaxation was significantly impaired in presence of PVAT in HFD mice (Emax = 71.0±5.1 vs Emax = 58.5±4.2, p<0.001. The inhibitory effect of L-NAME on Ach-induced relaxation was less intense in the HFD group compared with controls suggesting a reduction of endothelial NO availability. Expression of eNOS and NO bioavailability were reduced in MA and almost undetectable in mesenteric PVAT of the HFD group. Superoxide levels and NOX activity were higher in PVAT of HFD mice. Apocynin only reduced contractile responses to NA in HFD animals. Expression of ec-SOD and total SOD activity were significantly reduced in PVAT of HFD mice. No changes were observed in Mn-SOD, Cu/Zn-SOD or catalase. The ratio [GSSG]/([GSH]+[GSSG] was 2-fold higher in the mesenteric PVAT from HFD animals compared to controls. CONCLUSIONS: We suggest that the imbalance between pro-oxidant (NOX, superoxide anions, hydrogen peroxide and anti-oxidant (eNOS, NO, ecSOD, GSSG mechanisms in PVAT after long-term HFD might contribute to the aggravation of endothelial dysfunction.

  5. Long-Term Treatment with Losartan Attenuates Seizure Activity and Neuronal Damage Without Affecting Behavioral Changes in a Model of Co-morbid Hypertension and Epilepsy.

    Science.gov (United States)

    Tchekalarova, Jana D; Ivanova, Natasha; Atanasova, Dimitrina; Pechlivanova, Daniela M; Lazarov, Nikolai; Kortenska, Lidia; Mitreva, Rumiana; Lozanov, Valentin; Stoynev, Alexander

    2016-08-01

    Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy.

  6. Ability of palatable food consumption to buffer against the short- and long-term behavioral consequences of social defeat exposure during juvenility in rats.

    Science.gov (United States)

    MacKay, J C; Kent, P; James, J S; Cayer, C; Merali, Z

    2017-08-01

    In adult rats, access to a palatable diet can buffer against the effects of stressors. Approximately 10% of all adolescents are repeatedly victimized by their peers raising the possibility that palatable food consumption may be relevant to this developmental window. This study assessed the long-term impact of juvenile social defeat exposure on anxiety and depressive-like behavior and whether daily limited access to a palatable diet moderated these behavioral consequences. We also investigated the impact of the palatable diet on behavior during the defeat sessions. Juvenile rats were exposed to either a different adult resident rat (Stress) or handling (Control) from postnatal day (PD) 28-34. All rats had ad libitum access to either chow alone or both chow and limited access (4h/day) to palatable food commencing on PD 21. Results showed that during the defeat sessions, juvenile rats with access to the palatable diet spent less time in submissive postures and displayed significantly longer latencies to submit to the resident. In adulthood, previous exposure to juvenile social defeat resulted in a mild anxiogenic profile in the open field among rats with access to Chow only. Furthermore, defeated rats, regardless of diet, displayed reduced locomotor activity and increased social interaction as adults. These findings suggested only minimal enduring negative consequences from juvenile social defeat exposure which made it challenging to assess potential stress-buffering effects of the palatable diet. This was not the case during the defeat sessions where previous exposure to palatable food appeared protective against the acute stressor effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Long-term treatment with L-DOPA or pramipexole affects adult neurogenesis and corresponding non-motor behavior in a mouse model of Parkinson's disease.

    Science.gov (United States)

    Chiu, W-H; Depboylu, C; Hermanns, G; Maurer, L; Windolph, A; Oertel, W H; Ries, V; Höglinger, G U

    2015-08-01

    Non-motor symptoms such as hyposmia and depression are often observed in Parkinson's disease (PD) and can precede the onset of motor symptoms for years. The underlying pathological alterations in the brain are not fully understood so far. Dysregulation of adult neurogenesis in the dentate gyrus of the hippocampus and the olfactory bulb has been recently suggested to be implicated in non-motor symptoms of PD. However, there is so far no direct evidence to support the relationship of non-motor symptoms and the modulation of adult neurogenesis following dopamine depletion and/or dopamine replacement. In this study, we investigated the long-term effects of l-DOPA and pramipexole, a dopamine agonist, in a mouse model of bilateral intranigral 6-OHDA lesion, in order to assess the impact of adult neurogenesis on non-motor behavior. We found that l-DOPA and pramipexole can normalize decreased neurogenesis in the hippocampal dentate gyrus and the periglomerular layer of the olfactory bulb caused by a 6-OHDA lesion. Interestingly, pramipexole showed an antidepressant and anxiolytic effect in the forced swim test and social interaction test. However, there was no significant change in learning and memory function after dopamine depletion and dopamine replacement, respectively.

  8. Psychotherapy for social anxiety disorder: long-term effectiveness of resource-oriented cognitive-behavioral therapy and cognitive therapy in social anxiety disorder.

    Science.gov (United States)

    Willutzki, Ulrike; Teismann, Tobias; Schulte, Dietmar

    2012-06-01

    Resource-oriented cognitive-behavioral therapy (ROCBT) and cognitive therapy (CT) have been shown to be effective treatments for social anxiety disorder. However, so far few studies have examined the long-term effectiveness of these treatments. Thus, there is little information available about the durability of change in treated patients with social anxiety disorder. This study examined the effectiveness of both treatments at 2-year and 10-year follow-up assessments. Patients who received ROCBT or CT were re-contacted after 2 (n = 51), and 10 years (n = 27), respectively, and completed a battery of self-report questionnaires. Treatment gains were maintained over the 2-year follow-up on all measures. Furthermore, there was a significant improvement on 2 social anxiety measures between posttreatment and the 10-year follow-up. ROCBT and CT did not differ in overall effectiveness. The results suggest that both treatments are effective and durable approaches in the treatment of social anxiety disorder. © 2012 Wiley Periodicals, Inc.

  9. Assessment of long-term effects of exposure to toluene based on the analysis of selected behavioral responses with particular reference to the ability to trigger behavioral hypersensitivity in rats.

    Science.gov (United States)

    Wiaderna, Dorota; Tomas, Tadeusz

    2002-01-01

    Toluene is a major component of numerous commercial organic solvent formulations. It is often listed among the chemicals capable of producing the organic solvent syndrome and a neurobehavioral hypersensitivity condition. The hypersensitivity condition (continued long-term intensification of some behavioral reactions in response to pharmacological or environmental stressors) is usually associated with the increased tonus of the functional dopaminergic system. The aim of our current research was to determine whether, under conditions of inhalation exposure, toluene can produce long-term behavioral changes or modify the intensity of the behavioral response to apomorphine, a dopaminergic receptor agonist. In our experiment, male rats were exposed to 25, 100 and 250 ppm toluene for 4 weeks (5 days/week, 6h/day). The following behaviors were tested: finding water in a radial maze; open field motor activity, acquiring the conditional response of passive avoidance; sensitivity to a thermal pain stimulus (hot plate test) and changes in this sensitivity caused by stress; and acquiring the conditional response of two-directional active avoidance. The behavioral response to apomorphine, i.e. the increased spontaneous locomotor activity, was assessed on day 10 after the termination of the exposure in the rotary drum test. In the behavioral experiment, significant differences between groups were recorded only for the hot plate test; in the 100 and 250 ppm rats, electric-shock-related anxiety response was stronger than in the control group. In the experiment using pharmacological provocation, the behavioral response to apomorphine in the rats exposed to 100 ppm or 250 ppm toluene was significantly lower. Our results indicate that low concentrations of toluene may produce long-term behavioral changes in rats. However, these changes seem to be linked with reduced rather than increased functional tonus of the dopaminergic system.

  10. Long-term dietary strawberry, spinach, or vitamin E supplementation retards the onset of age-related neuronal signal-transduction and cognitive behavioral deficits.

    Science.gov (United States)

    Joseph, J A; Shukitt-Hale, B; Denisova, N A; Prior, R L; Cao, G; Martin, A; Taglialatela, G; Bickford, P C

    1998-10-01

    Recent research has indicated that increased vulnerability to oxidative stress may be the major factor involved in CNS functional declines in aging and age-related neurodegenerative diseases, and that antioxidants, e.g., vitamin E, may ameliorate or prevent these declines. Present studies examined whether long-term feeding of Fischer 344 rats, beginning when the rats were 6 months of age and continuing for 8 months, with diets supplemented with a fruit or vegetable extract identified as being high in antioxidant activity, could prevent the age-related induction of receptor-mediated signal transduction deficits that might have a behavioral component. Thus, the following parameters were examined: (1) oxotremorine-enhanced striatal dopamine release (OX-K+-ERDA), (2) cerebellar beta receptor augmentation of GABA responding, (3) striatal synaptosomal 45Ca2+ clearance, (4) carbachol-stimulated GTPase activity, and (5) Morris water maze performance. The rats were given control diets or those supplemented with strawberry extracts (SE), 9.5 gm/kg dried aqueous extract (DAE), spinach (SPN 6.4 gm/kg DAE), or vitamin E (500 IU/kg). Results indicated that SPN-fed rats demonstrated the greatest retardation of age-effects on all parameters except GTPase activity, on which SE had the greatest effect, whereas SE and vitamin E showed significant but equal protection against these age-induced deficits on the other parameters. For example, OX-K+-ERDA enhancement was four times greater in the SPN group than in controls. Thus, phytochemicals present in antioxidant-rich foods such as spinach may be beneficial in retarding functional age-related CNS and cognitive behavioral deficits and, perhaps, may have some benefit in neurodegenerative disease.

  11. Long-term post-stroke changes include myelin loss, specific deficits in sensory and motor behaviors and complex cognitive impairment detected using active place avoidance.

    Directory of Open Access Journals (Sweden)

    Jin Zhou

    Full Text Available Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1 sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2 complex active place avoidance learning (APA and simple passive avoidance retention (PA. Electroretinogram (ERG, hemispheric loss (infarction, hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001, sensory (p<0.001, beam balance performance (p<0.01 and hindlimb placement behavior (p<0.01. tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05 but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining. No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01 in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and

  12. Improving Women’s Preconceptional Health: Long-Term Effects of the Strong Healthy Women Behavior Change Intervention in the Central Pennsylvania Women’s Health Study

    Science.gov (United States)

    Weisman, Carol S.; Hillemeier, Marianne M.; Downs, Danielle Symons; Feinberg, Mark E.; Chuang, Cynthia H.; Botti, John J.; Dyer, Anne-Marie

    2013-01-01

    Purpose To investigate the long-term (6- and 12-month) effects of the Strong Healthy Women intervention on health-related behaviors, weight and body mass index (BMI), and weight gain during pregnancy. Strong Healthy Women is a small-group behavioral intervention for pre- and interconceptional women designed to modify key risk factors for adverse pregnancy outcomes; pretest–posttest findings from a randomized, controlled trial have been previously reported. The following questions are addressed: 1) were significant pretest–posttest changes in health-related behaviors (previously reported) maintained over the 12-month follow-up period; 2) did the intervention impact weight and BMI over the 12-month follow-up period; and 3) did the intervention impact pregnancy weight gain for those who gave birth during the follow-up period? Methods Data are from 6- and 12-month follow-up telephone interviews of women in the original trial of the Strong Healthy Women intervention (n = 362) and from birth records for singleton births (n = 45) during the 12-month follow-up period. Repeated measures regression was used to evaluate intervention effects. Main Findings At the 12-month follow-up, participants in the Strong Healthy Women intervention were significantly more likely than controls to use a daily multivitamin with folic acid and to have lower weight and BMI. The intervention’s effect on reading food labels for nutritional values dropped off between the 6- and 12-month follow-up. Among those who gave birth to singletons during the follow-up period, women who participated in the intervention had lower average pregnancy weight gain compared with controls. Although the intervention effect was no longer significant when controlling for pre-pregnancy obesity, the adjusted means show a trend toward lower weight gain in the intervention group. Conclusion These findings provide important evidence that the Strong Healthy Women behavior change intervention is effective in modifying

  13. Long-Term Effects of Prenatal Exposure to Undernutrition on Cannabinoid Receptor-Related Behaviors: Sex and Tissue-Specific Alterations in the mRNA Expression of Cannabinoid Receptors and Lipid Metabolic Regulators

    Science.gov (United States)

    Ramírez-López, María T.; Arco, Rocío; Decara, Juan; Vázquez, Mariam; Rivera, Patricia; Blanco, Rosario Noemi; Alén, Francisco; Gómez de Heras, Raquel; Suárez, Juan; Rodríguez de Fonseca, Fernando

    2016-01-01

    Maternal malnutrition causes long-lasting alterations in feeding behavior and energy homeostasis in offspring. It is still unknown whether both, the endocannabinoid (eCB) machinery and the lipid metabolism are implicated in long-term adaptive responses to fetal reprogramming caused by maternal undernutrition. We investigated the long-term effects of maternal exposure to a 20% standard diet restriction during preconceptional and gestational periods on the metabolically-relevant tissues hypothalamus, liver, and perirenal fat (PAT) of male and female offspring at adulthood. The adult male offspring from calorie-restricted dams (RC males) exhibited a differential response to the CB1 antagonist AM251 in a chocolate preference test as well as increased body weight, perirenal adiposity, and plasma levels of triglycerides, LDL, VLDL, bilirubin, and leptin. The gene expression of the cannabinoid receptors Cnr1 and Cnr2 was increased in RC male hypothalamus, but a down-expression of most eCBs-metabolizing enzymes (Faah, Daglα, Daglβ, Mgll) and several key regulators of fatty-acid β-oxidation (Cpt1b, Acox1), mitochondrial respiration (Cox4i1), and lipid flux (Pparγ) was found in their PAT. The female offspring from calorie-restricted dams exhibited higher plasma levels of LDL and glucose as well as a reduction in chocolate and caloric intake at post-weaning periods in the feeding tests. Their liver showed a decreased gene expression of Cnr1, Pparα, Pparγ, the eCBs-degrading enzymes Faah and Mgll, the de novo lipogenic enzymes Acaca and Fasn, and the liver-specific cholesterol biosynthesis regulators Insig1 and Hmgcr. Our results suggest that the long-lasting adaptive responses to maternal caloric restriction affected cannabinoid-regulated mechanisms involved in feeding behavior, adipose β-oxidation, and hepatic lipid and cholesterol biosynthesis in a sex-dependent manner. PMID:28082878

  14. Erythropoietin Restores Long-Term Neurocognitive Function Involving Mechanisms of Neuronal Plasticity in a Model of Hyperoxia-Induced Preterm Brain Injury

    Directory of Open Access Journals (Sweden)

    Daniela Hoeber

    2016-01-01

    Full Text Available Cerebral white and grey matter injury is the leading cause of an adverse neurodevelopmental outcome in prematurely born infants. High oxygen concentrations have been shown to contribute to the pathogenesis of neonatal brain damage. Here, we focused on motor-cognitive outcome up to the adolescent and adult age in an experimental model of preterm brain injury. In search of the putative mechanisms of action we evaluated oligodendrocyte degeneration, myelination, and modulation of synaptic plasticity-related molecules. A single dose of erythropoietin (20,000 IU/kg at the onset of hyperoxia (24 hours, 80% oxygen in 6-day-old Wistar rats improved long-lasting neurocognitive development up to the adolescent and adult stage. Analysis of white matter structures revealed a reduction of acute oligodendrocyte degeneration. However, erythropoietin did not influence hypomyelination occurring a few days after injury or long-term microstructural white matter abnormalities detected in adult animals. Erythropoietin administration reverted hyperoxia-induced reduction of neuronal plasticity-related mRNA expression up to four months after injury. Thus, our findings highlight the importance of erythropoietin as a neuroregenerative treatment option in neonatal brain injury, leading to improved memory function in adolescent and adult rats which may be linked to increased neuronal network connectivity.

  15. Erythropoietin Restores Long-Term Neurocognitive Function Involving Mechanisms of Neuronal Plasticity in a Model of Hyperoxia-Induced Preterm Brain Injury.

    Science.gov (United States)

    Hoeber, Daniela; Sifringer, Marco; van de Looij, Yohan; Herz, Josephine; Sizonenko, Stéphane V; Kempe, Karina; Serdar, Meray; Palasz, Joanna; Hadamitzky, Martin; Endesfelder, Stefanie; Fandrey, Joachim; Felderhoff-Müser, Ursula; Bendix, Ivo

    2016-01-01

    Cerebral white and grey matter injury is the leading cause of an adverse neurodevelopmental outcome in prematurely born infants. High oxygen concentrations have been shown to contribute to the pathogenesis of neonatal brain damage. Here, we focused on motor-cognitive outcome up to the adolescent and adult age in an experimental model of preterm brain injury. In search of the putative mechanisms of action we evaluated oligodendrocyte degeneration, myelination, and modulation of synaptic plasticity-related molecules. A single dose of erythropoietin (20,000 IU/kg) at the onset of hyperoxia (24 hours, 80% oxygen) in 6-day-old Wistar rats improved long-lasting neurocognitive development up to the adolescent and adult stage. Analysis of white matter structures revealed a reduction of acute oligodendrocyte degeneration. However, erythropoietin did not influence hypomyelination occurring a few days after injury or long-term microstructural white matter abnormalities detected in adult animals. Erythropoietin administration reverted hyperoxia-induced reduction of neuronal plasticity-related mRNA expression up to four months after injury. Thus, our findings highlight the importance of erythropoietin as a neuroregenerative treatment option in neonatal brain injury, leading to improved memory function in adolescent and adult rats which may be linked to increased neuronal network connectivity.

  16. The impact of dialysis-requiring acute kidney injury on long-term prognosis of patients requiring prolonged mechanical ventilation: nationwide population-based study.

    Directory of Open Access Journals (Sweden)

    Chia-Ter Chao

    Full Text Available BACKGROUND: Prolonged mechanical ventilation (PMV is increasingly common worldwide, consuming enormous healthcare resources. Factors that modify PMV outcome are still obscure. METHODS: We selected patients without preceding mechanical ventilation within the one past year and who developed PMV during index admission in Taiwan's National Health Insurance (NHI system during 1998-2007 for comparison of mortality and resource use. They were divided into three groups: (1 patients with end-stage renal diseases (ESRD before the index admission for PMV onset; (2 patients with dialysis-requiring acute kidney injury (AKI-dialysis during the hospitalization course; and (3 patients without AKI or with non dialysis-requiring AKI during the hospitalization course (non-AKI. We used a random-effects logistic regression model to identify factors associated with mortality. RESULTS: Compared with the other two groups, patients with AKI-dialysis had significantly longer mechanical ventilation, more frequent use of vasopressors, longer intensive care unit/hospital stay and higher inpatient expenditures during the index admission. Relative to non-AKI patients, patients with AKI-dialysis had an elevated mortality hazard; the adjusted relative risk ratios were 1.51 (95% confidence interval [CI]:1.46-1.56, 1.27 (95% CI: 1.23-1.32, and 1.10 (95% CI: 1.08-1.12 for mortality rates at discharge, 3 months, and 4 years after PMV, respectively. Patients with AKI-dialysis also consumed significantly higher total in-patient expenditure than the other two patient groups (p<0.001. CONCLUSIONS: Among patients that need PMV care during an admission, the presence of de novo AKI requiring dialysis significantly increased short and long term mortality, and demand for health care resources.

  17. Evaluation of guanfacine as a potential medication for alcohol use disorder in long-term drinking rats: behavioral and electrophysiological findings.

    Science.gov (United States)

    Fredriksson, Ida; Jayaram-Lindström, Nitya; Wirf, Malin; Nylander, Erik; Nyström, Erica; Jardemark, Kent; Steensland, Pia

    2015-03-13

    One of the main treatment challenges in alcohol use disorder (AUD) is the high rate of craving in combination with decreased cognitive functioning including impaired decision making and impulse control that often lead to relapse. Recent studies show that guanfacine, an α-2-adrenoceptor agonist and FDA-approved ADHD medication, attenuates stress-induced relapse of several drugs of abuse including alcohol. Here we evaluated guanfacine's effects on voluntary alcohol intake, the alcohol deprivation effect (ADE), alcohol seeking behavior, and cue/priming-induced reinstatement in Wistar rats that had voluntarily consumed alcohol for at least 2 months before treatment. In addition, guanfacine's ability to regulate glutamatergic neurotransmission was evaluated through electrophysiological recordings in medial prefrontal cortex (mPFC) slices prepared from long-term drinking rats (and alcohol-naive controls) that had received three daily guanfacine (0.6 mg/kg/day) or vehicle injections in vivo. Guanfacine decreased alcohol intake in high, but not low, alcohol-consuming rats and the effects were generally more long lasting than that of the AUD medication naltrexone. Repeated guanfacine treatment induced a long-lasting decrease in alcohol intake, persistent up to five drinking sessions after the last injection. In addition, guanfacine attenuated the ADE as well as alcohol seeking and cue/priming-induced reinstatement of alcohol seeking. Finally, subchronic guanfacine treatment normalized an alcohol-induced dysregulated glutamatergic neurotransmission in the mPFC. These results support previous studies showing that guanfacine has the ability to improve prefrontal connectivity through modulation of the glutamatergic system. Together with the fact that guanfacine appears to be clinically safe, these results merit evaluation of guanfacine's clinical efficacy in AUD individuals.

  18. Long-term urethral catheterisation.

    Science.gov (United States)

    Turner, Bruce; Dickens, Nicola

    This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

  19. Sociometric and ethological approach to the assessment of individual and group behavior in extra long-term isolation during simulated interplanetary mission

    Science.gov (United States)

    Gushin, Vadim; Tafforin, Carole; Kuznetsova, Polina; Vinokhodova, Alla; Chekalina, Angelina

    Several factors, such as hazard to life, reduced social communications, isolation, high workload, monotony, etc., can cause deconditioning of individual status and group dynamics in long-term spaceflight. New approaches to the assessment of group behavior are being developed in order to create necessary counter-measures and to keep optimal psychological climate in the crew. Psychological methods combined with ethological approach to dynamic monitoring of the isolated crew had been tested and validated in Mars-500 experiment. The experiment (duration of 520 days) was designed to simulate the living and working conditions of a piloted mission to Mars. The Mars-500 crew was composed of three Russians, two Europeans and one Chinese. We used psychological tests: sociometric questionnaire to assess group status (popularity) of the crewmembers (monthly), color choice test to assess the level of frustration and anxiety (twice a month). We performed observations from video recordings of group discussions (monthly) and during breakfast time (twice a month). The video analysis was supplied with a software based-solution: The Observer XT®. The results showed that occurrence of collateral acts may indicate psychological stress and fatigue in crewmembers under isolation and that facial expressions may indicate less anxiety. The data of psychological tests allowed to define two subgroups in the crew. The first one consisted of the subjects with high group status and lower level of frustration (not anxious), the second one consisted of less popular subjects, having respectively higher anxiety level. The video analysis showed two times more manifestations of facial expressions and interpersonal communications for the first subgroup. We also identified the subgroups on the basis of their verbal expressions in Russian and in English. Video observation of individual and group behavior, combined with other psychological tests gives opportunity to emphasize more objectively the signs

  20. Controls on the long term earthquake behavior of an intraplate fault revealed by U-Th and stable isotope analyses of syntectonic calcite veins

    Science.gov (United States)

    Williams, Randolph; Goodwin, Laurel; Sharp, Warren; Mozley, Peter

    2017-04-01

    U-Th dates on calcite precipitated in coseismic extension fractures in the Loma Blanca normal fault zone, Rio Grande rift, NM, USA, constrain earthquake recurrence intervals from 150-565 ka. This is the longest direct record of seismicity documented for a fault in any tectonic environment. Combined U-Th and stable isotope analyses of these calcite veins define 13 distinct earthquake events. These data show that for more than 400 ka the Loma Blanca fault produced earthquakes with a mean recurrence interval of 40 ± 7 ka. The coefficient of variation for these events is 0.40, indicating strongly periodic seismicity consistent with a time-dependent model of earthquake recurrence. Stochastic statistical analyses further validate the inference that earthquake behavior on the Loma Blanca was time-dependent. The time-dependent nature of these earthquakes suggests that the seismic cycle was fundamentally controlled by a stress renewal process. However, this periodic cycle was punctuated by an episode of clustered seismicity at 430 ka. Recurrence intervals within the earthquake cluster were as low as 5-11 ka. Breccia veins formed during this episode exhibit carbon isotope signatures consistent with having formed through pronounced degassing of a CO2 charged brine during post-failure, fault-localized fluid migration. The 40 ka periodicity of the long-term earthquake record of the Loma Blanca fault is similar in magnitude to recurrence intervals documented through paleoseismic studies of other normal faults in the Rio Grande rift and Basin and Range Province. We propose that it represents a background rate of failure in intraplate extension. The short-term, clustered seismicity that occurred on the fault records an interruption of the stress renewal process, likely by elevated fluid pressure in deeper structural levels of the fault, consistent with fault-valve behavior. The relationship between recurrence interval and inferred fluid degassing suggests that pore fluid pressure

  1. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating

    Science.gov (United States)

    The transport, retention, and long-term fate of zinc oxide nanoparticles (ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and t...

  2. The ten-year course of depression in primary care and long-term effects of psychoeducation, psychiatric consultation and cognitive behavioral therapy

    NARCIS (Netherlands)

    Conradi, Henk Jan; Bos, Elisabeth H; Kamphuis, Jan H; de Jonge, Peter

    BACKGROUND: While the majority of depressed patients are treated in primary care, long-term follow-up data on the naturalistic course of depression and treatment effectiveness in this setting are scarce. This study examined the ten-year course of depression in primary care patients who had

  3. Natural history of chronic hepatitis B virus infection from infancy to adult life - the mechanism of inflammation triggering and long-term impacts.

    Science.gov (United States)

    Wu, Jia-Feng; Chang, Mei-Hwei

    2015-10-20

    Chronic hepatitis B virus (HBV) infection in endemic areas usually starts since infancy and early childhood and persists lifelong. The clinical course varies among different chronic infected subjects. Majority of chronic HBV infected children present with immune-tolerant status initially, experience the immune clearance phase with various degree of liver injury during or beyond puberty, and then enter the inactive phase after hepatitis B e antigen (HBeAg) seroconversion. Part of them may have HBV DNA titers elevation with hepatitis flare after HBeAg seroconversion, the so call HBeAg-negative hepatitis flare. Liver cirrhosis, and even hepatocellular carcinoma may develop afterward.The complex course of chronic HBV infection is associated with the age/route of viral acquisition, host factors such as immune and endocrine factors, viral factors, and host-viral interactions. The adrenarche and puberty onset modulate the start of immune clearance and the severity of liver inflammation in chronic HBV infected children. The genotype and phenotype of human cytokines, innate immunity, and human leukocyte antigens are also associated with the onset of immune clearance of HBV and severity of inflammation. Immune escape HBV mutant strains, emerged during the immune clearance phase under host immune surveillance, may cause different impacts on viral biosynthesis, host immune responses, and clinical course.Early events in childhood during chronic HBV infection may serve as important predictors for the later outcome in adulthood. Understanding the mechanisms triggering liver inflammation and their long-term impacts may enhance the development of better and earlier therapeutic strategies for patients with chronic HBV infection.

  4. Changes in health risk behaviors of elementary school students in northern Taiwan from 2001 to 2003: results from the child and adolescent behaviors in long-term evolution study

    Directory of Open Access Journals (Sweden)

    Yen Lee-Lan

    2007-11-01

    Full Text Available Abstract Background Previous research has indicated that children's behaviors have long-term effects on later life. Hence it is important to monitor the development of health risk behaviors in childhood. This study examined the changes in health risk behaviors in fourth- to sixth-grade students in northern Taiwan from 2001 to 2003. Methods The Child and Adolescent Behaviors in Long-Term Evolution (CABLE study collected data from 1,820 students from 2001 to 2003 (students were 9 or 10 years old in 2001. Exploratory factor analysis was used to determine the aggregation of health risk behaviors. A linear growth curve model was used to determine whether health risk behaviors changed over time. Results Of the 13 behaviors, staying up late and eating snacks late at night were the most prevalent (82.3% of subjects in 2001, 81.8% in 2002, 88.5% in 2003 and second most prevalent (68.7%, 67.4%, 71.6% behaviors, respectively, from 2001 to 2003. The three least prevalent health risk behaviors were chewing betel nut (1.0%, 0.4%, 0.2%, smoking (1.4%, 1.0%, 0.8%, and drinking alcohol (8.5%, 6.0%, 5.2%. The frequencies of swearing and staying up late showed the greatest significant increases with time. On the other hand, suppressing urination and drinking alcohol decreased over time. Using exploratory factor analysis, we aggregated the health risk behaviors into three categories: unhealthy habits, aggressive behaviors, and substance use. Although students did not display high levels of aggressive behavior or experimentation with substances, the development of these behaviors in a small proportion of students should not be ignored. The results of the linear growth curve model indicated that unhealthy habits and aggressive behaviors increased over time. However, substance use slightly decreased over time. Conclusion We found that some health risk behaviors increased with time while others did not. Unhealthy habits and aggressive behaviors increased, whereas

  5. [Fetal pain: immediate and long term consequences].

    Science.gov (United States)

    Houfflin Debarge, Véronique; Dutriez, Isabelle; Pusniak, Benoit; Delarue, Eléonore; Storme, Laurent

    2010-06-01

    Several situations are potentially painful for fetuses, such as malformations and invasive procedures. Nociceptive pathways are known to be functional at 26 weeks. Even if it is not possible to evaluate the fetal experience of pain, it is essential to examine its immediate and long-term consequences. As early as the beginning of the second trimester, hemodynamic and hormonal responses are observed following fetal nociceptive stimulation, In experimental studies, long-term changes have been noted in the corticotrop axis, subsequent responses to pain, and behavior after perinatal nociceptive stimulation.

  6. Long-term Multiwavelength Observations of Polars

    Science.gov (United States)

    Santana, Joshua; Mason, Paul A.

    2016-06-01

    Polars are cataclysmic variables with the highest magnetic field strengths (10-250 MG). Matter is accreted after being funneled by the strong magnetic field of the white dwarf. We perform a meta-study of multi-wavelength data of polars. Many polars have been observed in surveys, such as SDSS, 2MASS, ROSAT, just to name a few. Some polars have now been detected by the JVLA, part of an expanding class of radio CVs. A large subset of polars have long-term optical light curves from CRTS and AAVSO. We suggest that the long term light curves of polars display a variety of signature behaviors and may be grouped accordingly. Additional characteristics such a binary period, magnetic field strengths, X-ray properties, and distance estimates are examined in context with long-term observations.

  7. Gratitude in Long Term Care

    Directory of Open Access Journals (Sweden)

    Brooke Abrams Sunding

    2015-04-01

    Full Text Available An exploratory study was conducted to examine the effectiveness of a group gratitude intervention with 29 permanent residents at a long term care/skilled nursing facility in improving elder mood, behavior and well- being over a 3 week time period. The sample included individuals diagnosed with dementia, other cognitive impairment, major depressive disorder, insomnia and generalized anxiety disorder. The gratitude intervention consisted of asking elders to share what they are thankful for at the dinner table each day. Measures included the Elder Well Being Scale and The Dinner Rating Scale. On both measures, higher scores indicated better functioning. To test the hypothesis that post treatment elder well-being will be significantly higher than pretreatment elder well-being ratings, a one-way ANOVA was conducted. Post-hoc tests revealed a statistically significant increase in Elder Well Being Scale scores. An ANOVA of comparing Dinner Ratings demonstrated a nonsignificant increase over the 3 week experiment. Implications are discussed.

  8. HIV-infected viremic long-term non-progressors and controllers display different immunological mechanisms for preserved CD4+cell counts

    Directory of Open Access Journals (Sweden)

    A Andersen

    2012-11-01

    Full Text Available Purpose: Most HIV-infected patients develop immunodeficiency without treatment. However, Long-Term Non Progressors (LTNP and Viremic Controllers (VC maintain normal CD4 counts and do not progress in the absence of treatment. While VC are able to control viral replication LTNP are not. Thus, lack of viral replication cannot explain non-progression in LTNP. Therefore we hypothesized that the immunological mechanism responsible for preserved CD4 counts in LTNP is different from that in VC. Methods: 69 treatment naïve HIV-infected patients were included in a cross-sectional study. A total of 14 LTNP (viral load, VL>5000 copies/ml, CD4+ cell count>350 cells/ul, infected>10 years, 30 VC (VL<5000 copies/ml, CD4 count>350 cells/ul, and 25 progressors (PR (VL>5.000 copies/ml, CD4 count>350 cells/ul were included. Immune activation (CD4+ and CD8+cells co-expressing CD38+HLA-DR+, apoptosis (CD8+CD28-CD95+, Th17 cells (CD4+CD161+, and regulatory T cells (Tregs, CD4+CD25+CD127lowFoxP3+ were evaluated using flow cytometry. For statistics Kruskal-Wallis test followed by Mann-Whitney U test were used. Data are given as medians. Summary of results: LTNP had higher frequency of activated CD4+ and CD8+cells compared to VC (3.4% vs. 1.6%, P=0.007, 21.7% vs. 12.0%, P=0.051 and similar levels to PR (4.2%, 22.4%, P>0.05. Likewise, LTNP had higher frequency of apoptotic cells compared to VC (63.7% vs. 48.6%, P=0.0408 and similar levels to PR (63.8%, P>0.05. Interestingly, borderline significant trends towards lower Th17/Treg ratio in LTNP compared to VC were found (3.8 vs. 5.5, P=0.068 while ratios in LTNP and PR were similar (4.0, P>0.05. Conclusion: LTNP displayed high levels of immune activation, apoptotic cells and reduced Th17/Treg ratio compared to VC, while LTNP were similar to PR. Thus, the immunological mechanism responsible for preserved CD4 counts in LTNP is still unclear but seems to be different from that in VC.

  9. Analysis of the Long-Term Corrosion Behavior of X80 Pipeline Steel in Acidic Red Soil Using Electrical Resistance Test Technique

    Directory of Open Access Journals (Sweden)

    Shuaixing Wang

    2015-01-01

    Full Text Available The long-term corrosion rate of X80 steel in an acidic red soil was monitored in situ by using a precise electrical resistance (ER test system. The corrosion characteristics of X80 steel were examined via SEM, EDS, and XRD. The results indicated that the corrosion rate determined from ER test was very similar to that obtained from the mass loss test. The ER test technique made it possible to predict the long-term corrosion rate of steel in soil in situ. The corrosion rate of X80 steel in acidic red soil was about 0.0902 mm/a at 38 weeks, but the corrosion rate was dropped to 0.0226 mm/a after 5 years. The final corrosion product layer was composed mainly of FeOOH, γ-Fe2O3, and FeCO3.

  10. Effect of enamel coating on long-term oxidation and hot corrosion behavior of Ti-24Al-17Nb-0.5Mo alloys

    Institute of Scientific and Technical Information of China (English)

    ZHENG De-you; XIONG Yu-ming; ZHU Sheng-long; WANG Fu-hui

    2004-01-01

    The effect of enamel coating on long-term isothermal oxidation at 700 ℃ and cyclic oxidation at 800 ℃ in air and hot corrosion resistance of Ti-24Al-17Nb-0. 5Mo in 75% (Na2SO4 + K2SO4 ) + 25% NaCl (mass fraction) molten mixed salts at 700 ℃ was investigated. The results indicate that Ti-24Al-17Nb-0.5Mo alloy exhibits relatively poor long-term oxidation resistance due to the formation of Al2O3 + TiO2 + Nb2O5 mixed scales and poor hot corrosion resistance due to the spallation of scales formed in molten (Ns, K)2 SO4 +NaCl. Enamel coating can effectively protect Ti-24Al-17Nb-0.5Mo alloy from long-term oxidation at high temperature in air and remarkably improve the hot corrosion resistance of Ti-24Al-17Nb-0. 5Mo alloy, and can act as the barrier to suppress the migration of oxygen and corrosive ions into the substrate.

  11. Mechanical cardiac remodeling and new-onset atrial fibrillation in long-term follow-up of subjects with chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    P.R. Benchimol-Barbosa

    2009-03-01

    Full Text Available Atrial fibrillation (AF affects subjects with Chagas' disease and is an indicator of poor prognosis. We investigated clinical, echocardiographic and electrocardiographic variables of Chagas' disease in a long-term longitudinal study as predictors of a new-onset AF episode lasting >24 h, nonfatal embolic stroke and cardiac death. Fifty adult outpatients (34 to 74 years old, 62% females staged according to the Los Andes classification were enrolled. During a follow-up of (mean ± SD 84.2 ± 39.0 months, 9 subjects developed AF (incidence: 3.3 ± 1.0%/year, 5 had nonfatal stroke (incidence: 1.3 ± 1.0%/year, and nine died (mortality rate: 2.3 ± 0.8%/year. The progression rate of left ventricular mass and left ventricular ejection fraction was significantly greater in subjects who experienced AF (16.4 ± 20.0 g/year and -8.6 ± 7.6%/year, respectively than in those who did not (8.2 ± 8.4 g/year; P = 0.03, and -3.0 ± 2.5%/year; P = 0.04, respectively. In univariate analysis, left atrial diameter ≥3.2 cm (P = 0.002, pulmonary arterial hypertension (P = 0.035, frequent premature supraventricular and ventricular contraction counts/24 h (P = 0.005 and P = 0.007, respectively, ventricular couplets/24 h (P = 0.002, and ventricular tachycardia (P = 0.004 were long-term predictors of AF. P-wave signal-averaged ECG revealed a limited long-term predictive value for AF. In chronic Chagas' disease, large left atrial diameter, pulmonary arterial hypertension, frequent supraventricular and ventricular premature beats, and ventricular tachycardia are long-term predictors of AF. The rate of left ventricular mass enlargement and systolic function deterioration impact AF incidence in this population.

  12. Long-term photometric behavior of the PMS stars V977 Cep and V982 Cep in the vicinity of NGC 7129

    CERN Document Server

    Ibryamov, Sunay I; Milanov, Teodor R; Peneva, Stoyanka P

    2016-01-01

    Long-term BVRI photometric light curves of the pre-main sequence stars V977 Cep and V982 Cep during the period from 2000 October to 2016 August are presented. The stars are located in the vicinity of the reflection nebula NGC 7129. Our photometric data shows that both stars exhibit strong photometric variability in all optical passbands, which is typical for Classical T Tauri stars. Using our observational data we defined the reasons for the observed brightness variations. In the case of V977 Cep we registered previously unknown periodicity in its light curve.

  13. The effect of a nutritional education program on the nutritional status of elderly patients in a long-term care hospital in Jeollanamdo province: health behavior, dietary behavior, nutrition risk level and nutrient intake.

    Science.gov (United States)

    Kim, Bok Hee; Kim, Mi-Ju; Lee, Yoonna

    2012-02-01

    This study was conducted to assess improvements in nutritional status following the application of nutrition education to elderly patients in a long-term care hospital. The study was carried out from January to May 2009, during which a preliminary survey, a pretest, the application of nutrition education, and a post-test were applied in stages. The number of subjects at pretest was 81, and the number of participants included in the final analysis was 61 (18 men, 43 women), all of whom participated in both the nutrition education program and the post-test. The survey consisted of general demographic items, health behaviors, dietary behaviors, the Nutrition Screening Initiative checklist, and nutrient intake assessment (24 hour recall method). The nutrition education program lasted for four weeks. It included a basic education program, provided once a week, and mini-education program, which was offered daily during lunch times. The survey was conducted before and after the education program using the same assessment method, although some items were included only at pretest. When analyzing the changes in elderly patients after the nutritional education program, we found that, among subjective dietary behaviors, self-rated perceptions of health (P nutritional risk levels decreased. In terms of nutrient intake, subjects' intake of energy, protein, fat, carbohydrate, calcium, phosphorus, iron, vitamin A, thiamin, riboflavin, niacin, and vitamin C all increased significantly (P nutritional education is effective in improving the nutritional status of elderly patients. We hope that the results of this study can be used as preliminary data for establishing guidelines for nutrition management tailored to elderly patients in long-term care hospitals.

  14. The effects of long-term administration of tadalafil on STZ-induced diabetic rats with erectile dysfunction via a local antioxidative mechanism

    Institute of Scientific and Technical Information of China (English)

    Yun Chen; Xiao-Xin Li; Hao-Cheng Lin; Xue-Feng Qiu; Jing Gao; Yu-Tian Dai; Run Wang

    2012-01-01

    Type 5 phosphodiesterase inhibitors (PDE51s) are well known being effective viathe nitric oxide and cyclic guanosine monophosphate (NO-cGMP) pathway and are widely used in the treatment of diabetic erectile dysfunction (ED).However,it is unclear whether other pathways may be involved in the treatment of diabetic ED with PDE51s.The purpose of this study was to clarify the role of antioxidants in diabetic ED treatment through the long-term administration of PDE51s.Three groups of Sprague-Dawley rats were utilized:Group N,the normal control; Group D,streptozotocin (STZ)-induced diabetic rats as a control; and Group D+T,STZ-induced diabetic rats who received oral administration of tadalafil for 8 weeks.Erectile function was assessed by intracavernous pressure (ICP) and mean arterial pressure (MAP) during electrical stimulation of the cavernous nerve before euthanasia.The levels of malondialdehyde (MDA),superoxide dismutase (SOD) and mitochondrial membrane potential (MMP) of cavernous tissue were assessed by biochemical analysis.The morphology of mitochondria was observed by electron microscopy.The ICP/MAP ratio was higher in Group D+T than in Group D (P<0.05).The levels of MDA decreased and the activities of SOD increased in Group D+T in comparison with Group D (P<0.05).The mitochondrial membrane potential level of cavernous tissue in diabetic rats was partially recovered by tadalafil treatment for 8 weeks.The morphology changes of mitochondria were also remarkably ameliorated in Group D+T.Collectively,the long-term administration of tadalafil in diabetic rats partially reduced oxidative stress lesions of the penis viaa local antioxidative stress pathway.Long-term dosages of tadalafil given once daily beginning soon after the onset of diabetes may aid in preventing rats from developing diabetic ED.

  15. Mechanical behaviors of nanowires

    Science.gov (United States)

    Chen, Yujie; An, Xianghai; Liao, Xiaozhou

    2017-09-01

    The mechanical behaviors of nanowires (NWs) are significantly different from those of their bulk materials because of their small dimensions. Determining the mechanical performance of NWs and understanding their deformation behavior are crucial for designing and manufacturing NW-based devices with predictable and reproducible operation. Owing to the difficulties to manipulate these nanoscale materials, nanomechanical testing of NWs is always challenging, and errors can be readily introduced in the measured mechanical data. Here, we survey the techniques that have been developed to quantify the mechanical properties and to understand the deformation mechanisms of NWs. We also provide a general review of the mechanical properties and deformation behaviors of NWs and discuss possible sources responsible for the discrepancy of measured mechanical properties. The effects of planar defects on the mechanical behavior of NWs are also reviewed.

  16. Further development, quality assurance and long-term behaviour of vacuum insulation panels with mechanical protection; Weiterentwicklung, QS und Langzeitverhalten von Vakuumisolationspaneelen mit mechanischem Schutz

    Energy Technology Data Exchange (ETDEWEB)

    Simmler, H.

    2008-12-15

    This report for the Swiss Federal Office of Energy (SFOE) takes a look at the results obtained for two long-term studies on the use of vacuum insulation panels. Along with temperature and humidity measurements, the vacuum in the panels in two installations - one as part of the floor insulation in a deep-freeze room and another as insulation for a flat roof - were monitored with special integrated sensors. The ageing and the (slight) deterioration of insulation values are commented on. The measurement methods used and the results obtained are compared with laboratory values. The further development of VIP vacuum insulation panels for facades is examined.

  17. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating.

    Science.gov (United States)

    Han, Yosep; Hwang, Gukhwa; Kim, Donghyun; Bradford, Scott A; Lee, Byoungcheun; Eom, Igchun; Kim, Pil Je; Choi, Siyoung Q; Kim, Hyunjung

    2016-03-01

    The transport, retention, and long-term release of zinc oxide nanoparticle aggregates (denoted below as ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and the ionic strength (IS) was 0.1 or 10 mM NaCl, and the retention profiles were always hyper-exponential. Increasing the solution IS and biofilm coating produced enhanced retention of ZnO-NPs near the column inlet. The enhanced NPs retention at high IS was attributed to more favorable NP-silica and NP-NP interactions; this was consistent with the interaction energy calculations. Meanwhile, the greater NPs retention in the presence of biofilm was attributed to larger roughness heights which alter the mass transfer rate, the interaction energy profile, and lever arms associated with the torque balance; e.g., scanning electron and atomic force microscopy was used to determine roughness heights of 33.4 nm and 97.8 nm for bare sand and biofilm-coated sand, respectively. Interactions between NPs and extracellular polymeric substances may have also contributed to enhanced NP retention in biofilm-coated sand at low IS. The long-term release of retained ZnO-NPs was subsequently investigated by continuously injecting NP-free solution at pH 6, 9, or 10 and keeping the IS constant at 10 mM. The amount and rate of retained ZnO-NP removal was strongly dependent on the solution pH. Specifically, almost complete removal of retained ZnO-NPs was observed after 627 pore volumes when the solution pH was 6, whereas much less Zn was recovered when the eluting solution pH was buffered to pH = 9 and especially 10. This long-term removal was attributed to pH-dependent dissolution of retained ZnO-NPs because: (i) the solubility of ZnO-NPs increases with decreasing pH; and (ii) ZnO-NPs were not detected in the effluent. The presence of biofilm also decreased the

  18. F-centers mechanism of long-term relaxation in lead zirconate-titanate based piezoelectric ceramics. 2. After-field relaxation

    Science.gov (United States)

    Ishchuk, V. M.; Kuzenko, D. V.

    2016-08-01

    The paper presents results of experimental study of the dielectric constant relaxation during aging process in Pb(Zr,Ti)O3 based solid solutions (PZT) after action of external DC electric field. The said process is a long-term one and is described by the logarithmic function of time. Reversible and nonreversible relaxation process takes place depending on the field intensity. The relaxation rate depends on the field strength also, and the said dependence has nonlinear and nonmonotonic form, if external field leads to domain disordering. The oxygen vacancies-based model for description of the long-term relaxation processes is suggested. The model takes into account the oxygen vacancies on the sample's surface ends, their conversion into F+- and F0-centers under external effects and subsequent relaxation of these centers into the simple oxygen vacancies after the action termination. F-centers formation leads to the violation of the original sample's electroneutrality, and generate intrinsic DC electric field into the sample. Relaxation of F-centers is accompanied by the reduction of the electric field, induced by them, and relaxation of the dielectric constant, as consequent effect.

  19. Creep-rupture behavior of candidate Stirling engine alloys after long-term aging at 760 deg C in low-pressure hydrogen

    Science.gov (United States)

    Titran, R. H.

    1984-01-01

    Nine candidate Stirling automotive engine alloys were aged at 760 C for 3500 hr in low pressure hydrogen or argon to determine the resulting effects on mechanical behavior. Candidate heater head tube alloys were CG-27, W545, 12RN72, INCONEL-718, and HS-188 while candidate cast cylinder-regenerator housing alloys were SA-F11, CRM-6D, XF-818, and HS-31. Aging per se is detrimental to the creep rupture and tensile strengths of the iron base alloys. The presence of hydrogen does not significantly contribute to strength degradation. Based percent highway driving cycle; CG-27 has adequate 3500 hr - 870 C creep rupture strength and SA-Fll, CRM-6D, and XF-818 have adequate 3500 hr - 775 C creep rupture strength.

  20. Long-term aerobic exercise and omega-3 supplementation modulate osteoporosis through inflammatory mechanisms in post-menopausal women: a randomized, repeated measures study

    Directory of Open Access Journals (Sweden)

    Kanaley Jill

    2011-10-01

    Full Text Available Abstract Background Evidence indicates that dietary fats and physical activity influence bone health. The purpose of this study was to examine the effects of long-term aerobic exercise and omega-3 (N-3 supplementation on serum inflammatory markers, bone mineral density (BMD, and bone biomarkers in post-menopausal women. Methods Seventy-nine healthy sedentary post-menopausal women aged 58-78 years participated in this study. Subjects were randomized to one of 4 groups: exercise + supplement (E+S, n = 21, exercise (E, n = 20, supplement (S, n = 20, and control (Con, n = 18 groups. The subjects in the E+S and E groups performed aerobic exercise training (walking and jogging up to 65% of HRmax, three times a week for 24 weeks. Subjects in the E+S and S groups consumed 1000 mg/d N-3 for 24 weeks. The lumbar spine (L2-L4 and femoral neck BMD, serum tumor necrosis factor (TNF α, interleukin (IL 6, prostaglandin (PG E2, estrogen, osteocalcin, 1, 25-dihydroxyvitamin D3 (1, 25 Vit D, C-telopeptide (CTX, parathyroid hormone (PTH and calcitonin (CT were measured at baseline, the end of week 12 and 24. Results Serum estrogen, osteocalcin, 1, 25 Vit D, CT, L2-L4 and femoral neck BMD measures increased (P 2 decreased (P 2-L4 and femoral neck BMD, estrogen, osteocalcin, and CT were negatively (P 2. PTH and CT were correlated positively and negatively with IL-6, respectively (P Conclusions The present study demonstrates that long-term aerobic exercise training plus N-3 supplementation have a synergistic effect in attenuating inflammation and augmenting BMD in post-menopausal osteoporosis.

  1. Case presentation: long-term treatment.

    Science.gov (United States)

    Glucksman, Myron L

    2013-01-01

    The long-term (14 years) psychodynamic psychotherapy and pharmacotherapy of a depressed, suicidal, self-mutilating female patient is described. Her diagnoses included Chronic Posttraumatic Stress Disorder, Borderline Personality Disorder, and Recurrent Major Depression. Treatment was punctuated with repeated hospitalizations for self-mutilation (cutting) and suicidal ideation. A major determinant for her psychopathology was sexual abuse by her father from ages 6 to 14. This resulted in feelings of guilt and rage that she repressed and acted out through self-mutilating and suicidal behavior. A prolonged negative transference gradually became ambivalent, then positive. This was associated with her internalization of the healing qualities of the therapeutic relationship. She also gained insight into the reasons for her need to punish herself. Her initial self-representation as unworthy and bad was transformed into perceiving herself as a worthwhile, loving person. This case illustrates the role of long-term treatment for a complex, life-threatening, psychiatric disorder.

  2. Analysing long term discursive processes

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    What do timescales - the notion that processes take place or can be viewed within a shorter or longer temporal range (Lemke 2005) - mean for the analysis of discourse? What are the methodological consequences of analyzing discourse at different timescales? It may be argued that discourse analysis...... in general has favored either the analysis of short term processes such as interviews, discussions, and lessons, or the analysis of non-processual entities such as (multimodal) texts, arguments, discursive repertoires, and discourses (in a Foucaultian sense). In contrast, analysis of long term processes...... which extend beyond the single interaction, for instance negotiations or planning processes, seems to have played a less important role, with studies such as Iedema 2001 and Wodak 2000 as exceptions. These long term processes, however, are central to the constitution and workings of organizations...

  3. Long term evolution 4G and beyond

    CERN Document Server

    Yacoub, Michel; Figueiredo, Fabrício; Tronco, Tania

    2016-01-01

    This book focus on Long Term Evolution (LTE) and beyond. The chapters describe different aspects of research and development in LTE, LTE-Advanced (4G systems) and LTE-450 MHz such as telecommunications regulatory framework, voice over LTE, link adaptation, power control, interference mitigation mechanisms, performance evaluation for different types of antennas, cognitive mesh network, integration of LTE network and satellite, test environment, power amplifiers and so on. It is useful for researchers in the field of mobile communications.

  4. Cambio de conductas en tratamientos de larga duracion: Relacion medico-paciente Behavior changes in long-term treatment: Physician-patient relationship

    Directory of Open Access Journals (Sweden)

    Monica Facchini

    2004-12-01

    Full Text Available Las enfermedades crónicas como la diabetes, la obesidad y la hipertensión arterial, entre otras, requieren de tratamientos prolongados. El establecimiento de un vínculo básico se constituye en la piedra fundamental de toda acción terapéutica. En el enfoque centrado en el paciente se busca entrar en su mundo para comprender la vivencia subjetiva de la enfermedad en un marco más amplio. Es relevante integrar al paciente como un participante activo, valorado y esencial para el proceso de cambio. La manera en que se prescribe es tan valiosa como el tratamiento mismo; el objetivo es enseñar al paciente a seguirlo, las recaídas no deben ser vistas como fracasos sino como una oportunidad más de aprender. Los pacientes necesitan encontrar sus propias soluciones y motivaciones, y hacerse responsables de su salud; los profesionales de la salud necesitamos darles el poder para hacerlo. Las intervenciones exitosas y más efectivas en el largo plazo requieren de un enfoque terapéutico que haga hincapié en la adherencia al mismo y en el autocuidado.Chronic diseases such as diabetes, obesity and hypertension, among others, need long term treatments. The constitution of a basic alliance is the cornerstone of any therapeutic action. In the patient-centered approach, the aim is to enter their world in order to understand the subjective experience of the disease in a broader frame. It is relevant to involve the patient as an active, respected and fundamental participant of the changing process. The way a treatment is prescribed is as important as the treatment itself; the aim is to teach the patient how to follow his/her own treatment, relapses must not be considered failures but opportunities for learning. Patients need to find their own solutions and motivations and be responsible for their health on a daily basis. We need to empower them to do so. Long-term, successful and effective interventions require a treatment which focuses on compliance and

  5. Long-term behavior of the Kelvin waves revealed by CHAMP/GPS RO measurements and their effects on the tropopause structure

    Directory of Open Access Journals (Sweden)

    M. Venkat Ratnam

    2006-07-01

    Full Text Available The vertical and temporal variations of Kelvin waves and the associated effects on the tropical tropopause were studied using long-term (from May 2001 to October 2005 CHAMP/GPS (CHAllenging Mini satellite Payload/Global Positioning System radio occultation (RO measurements. The periods of these waves were found to be varying in between 10 and 15 days, with vertical wavelengths 5–8 km. These variations clearly show eastward phase propagation in the time-longitude section and eastward phase tilts with height in altitude-longitude, displaying the characteristics of Kelvin waves. The peak variance in the temperature is found over the Indian Ocean and into the western Pacific within the broad region of the equator. Kelvin wave amplitudes were found significantly enhanced in the eastward shear of the quasi-biennial oscillation (QBO and are confined in and around the tropopause during westward phase of QBO, where it extends between 17 and 25 km during the eastward phase of QBO and is damped away above, consistent with earlier reported results. The amplitudes are increasing during the months of Northern Hemisphere winter and sometimes they are highly sporadic in nature. Seasonal and inter-annual variations in the Kelvin wave amplitudes near the tropical tropopause coincide exactly with the tropopause height and temperature, with a sharp tropopause during maximum Kelvin wave activity. A clear annual oscillation, along with a month-to-month coincidence is evident most of the time in both the tropopause height and Kelvin wave activity, with maximum and minimum Kelvin wave amplitudes during the Northern Hemisphere winter and summer, respectively. In addition, a signature of quasi-biennial oscillation (QBO in the tropopause structure is also seen in long-term tropopause variations, although the amplitudes are less when compared to the annual oscillation. In the westward phase of QBO (during strong Kelvin wave activity at 20km (in 2001–2002 winter and

  6. Protective Effects of Hydrogen against Low-Dose Long-Term Radiation-Induced Damage to the Behavioral Performances, Hematopoietic System, Genital System, and Splenic Lymphocytes in Mice

    Science.gov (United States)

    Lei, Xiao; Zhao, Hainan; Liu, Pengfei; Xu, Yang; Chen, Yuanyuan; Chuai, Yunhai

    2016-01-01

    Molecular hydrogen (H2) has been previously reported playing an important role in ameliorating damage caused by acute radiation. In this study, we investigated the effects of H2 on the alterations induced by low-dose long-term radiation (LDLTR). All the mice in hydrogen-treated or radiation-only groups received 0.1 Gy, 0.5 Gy, 1.0 Gy, and 2.0 Gy whole-body gamma radiation, respectively. After the last time of radiation exposure, all the mice were employed for the determination of the body mass (BM) observation, forced swim test (FST), the open field test (OFT), the chromosome aberration (CA), the peripheral blood cells parameters analysis, the sperm abnormality (SA), the lymphocyte transformation test (LTT), and the histopathological studies. And significant differences between the treatment group and the radiation-only groups were observed, showing that H2 could diminish the detriment induced by LDLTR and suggesting the protective efficacy of H2 in multiple systems in mice against LDLTR. PMID:27774116

  7. Protective Effects of Hydrogen against Low-Dose Long-Term Radiation-Induced Damage to the Behavioral Performances, Hematopoietic System, Genital System, and Splenic Lymphocytes in Mice

    Directory of Open Access Journals (Sweden)

    Jiaming Guo

    2016-01-01

    Full Text Available Molecular hydrogen (H2 has been previously reported playing an important role in ameliorating damage caused by acute radiation. In this study, we investigated the effects of H2 on the alterations induced by low-dose long-term radiation (LDLTR. All the mice in hydrogen-treated or radiation-only groups received 0.1 Gy, 0.5 Gy, 1.0 Gy, and 2.0 Gy whole-body gamma radiation, respectively. After the last time of radiation exposure, all the mice were employed for the determination of the body mass (BM observation, forced swim test (FST, the open field test (OFT, the chromosome aberration (CA, the peripheral blood cells parameters analysis, the sperm abnormality (SA, the lymphocyte transformation test (LTT, and the histopathological studies. And significant differences between the treatment group and the radiation-only groups were observed, showing that H2 could diminish the detriment induced by LDLTR and suggesting the protective efficacy of H2 in multiple systems in mice against LDLTR.

  8. Long-Term Dynamics of Autonomous Fractional Differential Equations

    Science.gov (United States)

    Liu, Tao; Xu, Wei; Xu, Yong; Han, Qun

    This paper aims to investigate long-term dynamic behaviors of autonomous fractional differential equations with effective numerical method. The long-term dynamic behaviors predict where systems are heading after long-term evolution. We make some modification and transplant cell mapping methods to autonomous fractional differential equations. The mapping time duration of cell mapping is enlarged to deal with the long memory effect. Three illustrative examples, i.e. fractional Lotka-Volterra equation, fractional van der Pol oscillator and fractional Duffing equation, are studied with our revised generalized cell mapping method. We obtain long-term dynamics, such as attractors, basins of attraction, and saddles. Compared with some existing stability and numerical results, the validity of our method is verified. Furthermore, we find that the fractional order has its effect on the long-term dynamics of autonomous fractional differential equations.

  9. Enlightenment of Construcing Long-term Administration Mechanism for Nursing Ouality%护理质量长效管理机制的构建与启示

    Institute of Scientific and Technical Information of China (English)

    王晓霞; 赵璧; 李妮; 陈璟; 岳素琴

    2011-01-01

    目的 探讨长效管理机制在护理质量管理中的应用.方法 对8项护理质量进行现场实时调查评估,应用长效管理的方法进行考核评价.结果 医院护理服务质量和技术质量等显著提高,护理人员对安全风险防范的意识大大增强.结论 应用长效管理机制对护理质量进行管理效果明显.%Objective To explore the application of long-term administration mechanism in the manage-ment of nursing quality. Methods A real-time & on-site assessment was conducted on the 8 nursing items of nursing quality, which was followed by an evaluation using long-term effective management. Results The qualities of hospital nursing service and technology were significantly improved and the awareness of risk prevention was increased greatly for the paramedic as well. Conclusion The nursing quality of is sig-nificantly improved by long-term management mechanism.

  10. Long Term Study of Protective Mechanisms of Human Adipose Derived Mesenchymal Stem Cells on Cisplatin Induced Kidney injury in Sprague-Daweley Rats

    Directory of Open Access Journals (Sweden)

    Elhusseini FM

    2016-05-01

    Full Text Available Background/Aims: Long-term evaluation of cisplatin induced nephrotoxicity and the probable renal protective activities of stem cells are lacking up until now. We evaluated the early and long-term role of human adipose derived mesenchymal stem cells (ADMSCs in prevention or amelioration of cisplatin induced acute kidney injury (AKI in Sprague-Dawley rats. For this, we determined the kidney tissue level of oxidative stress markers in conjugation with a renal histopathological scoring system of both acute and chronic renal changes. Methods: This study used eighty Sprague-Dawley (SD rats weighing 250-300g. They were assigned into four equal groups (each group n=20: (I Negative control group, rats injected with single dose of 1 ml normal saline. (II Positive control cisplatin, rats injected with a single dose of 5 mg/kg I.P in 1 ml saline. (III Cisplatin and culture media group, rats injected with 0.5 ml of culture media single dose into the tail vein and (IV Cisplatin and ADMSCs group, rats injected with a single dose of 0.5 ml of culture media containing 5 x106ADMSCs into the tail vein one day after cisplatin administration. Each main group was further divided according to the timing of sacrifice into four subgroups (each subgroup n=5. Rats in the subgroup A were sacrificed after 4 days; subgroup B were sacrificed after 7 days; subgroup C were sacrificed after 11 days; and subgroup D were sacrificed after 30 days. Before sacrifice, 24 hrs.-urine was collected using a metabolic cage. Renal function was evaluated through blood urea nitrogen (BUN, serum creatinine and creatinine clearance. Kidney tissue homogenate oxidative stress parameters, Malondialdehyde (MDA, Superoxide dismutase (SOD and Glutathione (GSH were determined. In addition, histopathological analysis for active injury, regenerative and chronic changes was performed. Results: ADMSCs were characterized and their capability of differentiation was proved. Cisplatin induced a significant

  11. Phytolith-occluded organic carbon as a mechanism for long-term carbon sequestration in a typical steppe: The predominant role of belowground productivity.

    Science.gov (United States)

    Qi, Limin; Li, Frank Yonghong; Huang, Zhangting; Jiang, Peikun; Baoyin, Taogetao; Wang, Hailong

    2017-01-15

    Phytolith-occluded organic carbon (phytOC) has recently been demonstrated to be an important terrestrial carbon (C) fraction resistant to decomposition and thus has potential for long-term C sequestration. Existing studies show that plant leaves and sheath normally have high phytOC concentration, thus most of phytOC studies are limited to the aboveground plant parts. Grassland communities comprise herbaceous species, especially grasses and sedges which have relatively high concentrations of phytoliths, but the phytOC production from grassland, especially from its belowground part, is unknown. Here we determined the phytOC concentration in different parts of major plant species in a typical steppe grassland on the Mongolian Plateau, and estimated the phytolith C sequestration potential. We found that the phytOC concentration of major steppe species was significantly (pphytolith C sequestration of grasslands may be at least one order of magnitude greater than the previous estimation based on ANPP only. Our results emphasize the need for more research on phytolith and phytOC distribution and flux in both above and below ground plant parts for quantifying the phytolith C sequestration. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Respiratory failure due to morbid obesity in a patient with Prader-Willi syndrome: an experience of long-term mechanical ventilation.

    Science.gov (United States)

    Nishikawa, Masashi; Mizutani, Taro; Nakao, Tomohei; Kamoda, Tomohiro; Takahashi, Shinji; Toyooka, Hidenori

    2006-01-01

    Prader-Willi syndrome (PWS) is characterized by obesity, mild mental retardation or learning disability, and behavior problems, especially in association with food and eating. A 19 year-old man, 150 cm, 140 kg (body mass index [BMI], 62.2 kg.m(-2)), whose condition had been diagnosed as PWS, received 41-day mechanical ventilation because of respiratory failure, chiefly due to morbid obesity. Because the patient frequently developed bronchoconstriction, metered-dose inhalers of a corticosteroid (beclomethasone dipropionate) and a beta2 agonist (salbutamol) were needed. To achieve adequate sedation, which was also crucial to control the bronchoconstriction, the concurrent use of midazolam, fentanyl, ketamine, and propofol was required. Pressure-control ventilation was useful to avoid high airway pressure due to low respiratory system compliance associated with the morbid obesity. Because it appeared that the basic problem leading to respiratory failure in this patient was morbid obesity, body weight reduction was considered to be mandatory. Thus, caloric intake was limited to 1000 kcal.day(-1), resulting in body weight reduction by 50 kg during the patient's stay in the intensive care unit (ICU). The patient was successfully extubated on ICU day 35.

  13. Long-term consequences of membership in trajectory groups of delinquent behavior in an urban sample: violence, drug use, interpersonal, and neighborhood attributes.

    Science.gov (United States)

    Brook, Judith S; Lee, Jung Yeon; Finch, Stephen J; Brown, Elaine N; Brook, David W

    2013-01-01

    Research on stability and change in delinquent behavior over time has important implications for both the individual and the criminal justice system. The present research looks at this issue by examining the associations between the trajectories of delinquent behavior in adolescence and adult functioning. Data for the present study are from a four-wave longitudinal study of African American and Hispanic participants. Participants provided information at mean ages 14, 19, 24, and 29. We used growth mixture modeling to extract trajectory groups of delinquent behavior in adolescence and young adulthood. Regression analyses were conducted to examine whether memberships in the trajectory groups of delinquent behavior from mean age 14 to mean age 24 were associated with violence, substance abuse and dependence, partner discord, peer substance use, and residence in a high-crime neighborhood at mean age 29 when compared with the reference trajectory group of participants with low or no delinquent behavior. Four trajectory groups of delinquent behavior were identified: the no/low, the decreasing, the moderate, and the high persistent trajectory groups. Memberships in the trajectory groups were significantly correlated with variations in adult functioning. Memberships in some trajectory groups of delinquent behavior are significant predictors of later violent behavior, substance abuse and dependence, partner discord, peer substance use, and residence in a high-crime neighborhood. The findings reinforce the importance of investing in interventions to address different patterns of delinquent behavior. Findings are discussed in relation to previous investigations with non-Hispanic White samples.

  14. Perceived Work Ability in the Light of Long-Term and Stress-Related Unhealthy Behaviors-a Prospective Cohort Study.

    Science.gov (United States)

    Nevanperä, Nina; Seitsamo, Jorma; Ala-Mursula, Leena; Remes, Jouko; Hopsu, Leila; Auvinen, Juha; Tammelin, Tuija; Järvelin, Marjo-Riitta; Laitinen, Jaana

    2016-04-01

    Most of the few studies that exist on the longitudinal associations between health behaviors and work ability target to single health behaviors. To investigate how lifetime clusters of unhealthy behaviors associate with perceived work ability in early midlife. The study population consisted of 46-year-old men and women (n = 3107) born in Northern Finland in 1966. Their current perceived work ability compared to lifetime best, and their unhealthy behaviors (physical inactivity, smoking, and alcohol consumption) were assessed by questionnaires. We determined clusters of unhealthy behaviors at the ages of 14, 31, and 46 and created lifetime development trajectories of health behaviors. We also assessed stress-related eating and drinking at the ages of 31 and 46. Cross-tabulations and multivariate logistic regression models were used to investigate the associations between clusters of health behaviors, stress-related eating and drinking, and work ability at 46 years. The analyses were controlled for basic education and physical strenuousness of work, psychosocial job characteristics, perceived work ability, and BMI (kg/m(2)) at 31 years. Four health behavior trajectories emerged: always healthy, moderate (reference group), deteriorated. and always unhealthy. Among men, always unhealthy behaviors [OR (95 % confidence interval) 2.81 (1.35, 5.86)], and among women, deteriorated health behaviors [1.67 (1.07, 2.58)] associated with poor perceived work ability at 46 years. In addition, stress-related eating and drinking associated independently with poor perceived work ability at 46 years [men 2.58 (1.62, 4.12) and women 2.48 (1.70, 3.61)]. Long-lasting and stress-related unhealthy behaviors increase the risk of poor work ability in midlife.

  15. New Rapid Evaluation for Long-Term Behavior in Deep Geological Repository by Geotechnical Centrifuge. Part 1: Test of Physical Modeling in Near Field Under Isotropic Stress-Constraint Conditions

    Science.gov (United States)

    Nishimoto, Soshi; Sawada, Masataka; Okada, Tetsuji

    2016-08-01

    The objective of this study is to evaluate the long-term geomechanical behavior of a geological repository for high-level radioactive waste disposal, using the centrifugal near-field model test. The model consisted of a sedimentary rock mass, bentonite buffer, and model overpack, and was enclosed within a pressure vessel. Tests were conducted with a centrifugal force field of 30 G under isotropic stress-constraint conditions with confining pressures of 5-10 MPa and injection of pore water up through a time period equivalent to about 165 years in the field. Our results showed that the measured values and the temporal changes in the displacement of the overpack, the soil pressure of the bentonite, and the strain of the rock mass were clearly dependent on the confining pressure. These data were not convergent during the test. Our data experimentally revealed that long-term behavior in the near field was changed by the geomechanical interaction between the deformation stress of the bedrock/disposal hole and the swelling behavior of the bentonite buffer.

  16. Significance Analysis of Building Long-term Mechanism of Social Stability in Ethnic Minority%构建少数民族地区社会稳定长效机制的战略意义

    Institute of Scientific and Technical Information of China (English)

    高翔

    2011-01-01

    构建少数民族地区社会稳定长效机制,是根据少数民族地区社会关系发展规律和维稳工作规律,探索维护少数民族地区社会稳定长期效应的工作机理及其制度体系的一项重要工作。对保持少数民族地区长治久安、民族团结、经济发展与社会和谐具有重要意义。%building a long-term mechanism of social stability in ethnic minority areas is an important work, and it has to explore the laws and long-term effects of social stability in accordance with social relations in the areas. Therefore, the research will be significant for maintaining long-term stability, national unity, economic development and social harmony in ethnic minority areas.

  17. Long term stability of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Kundur, P.; Gao, B. [Powertech Labs. Inc., Surrey, BC (Canada)

    1994-12-31

    Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

  18. Long-term repetitive mechanical loading of the knee joint by in vivo muscle stimulation accelerates cartilage degeneration and increases chondrocyte death in a rabbit model.

    Science.gov (United States)

    Horisberger, Monika; Fortuna, Rafael; Valderrabano, Victor; Herzog, Walter

    2013-06-01

    Excessive chronic loading is thought to be one factor responsible for the onset of osteoarthritis. For example, studies using treadmill running have shown an increased risk for osteoarthritis, thereby suggesting that muscle-induced joint loading may play a role in osteoarthritis onset and progression. However, in these studies, muscle-induced loading was not carefully quantified. Here, we present a model of controlled muscular loading which allows for the accurate quantification of joint loading. The aim of this study was to evaluate the effects of long-term, cyclic, isometric and dynamic, muscle-induced joint loading of physiologic magnitude but excessive intensity on cartilage integrity and cell viability in the rabbit knee. 24 rabbits were divided into an (i) eccentric, (ii) concentric, or (iii) isometric knee extensor contraction group (50 min of cyclic, submaximal stimulation 3 times/week for four weeks=19,500 cycles) controlled by the stimulation of a femoral nerve cuff electrode on the right hind limb. The contralateral knee was used as a non-loaded control. The knee articular cartilages were analysed by confocal microscopy for chondrocyte death, and histologically for Mankin Score, cartilage thickness and cell density. All loaded knees had significantly increased cell death rates and Mankin Scores compared to the non-loaded joints. Cartilage thicknesses did not systematically differ between loaded and control joints. Chondrocyte death and Mankin Scores were significantly increased in the loaded joints, thereby linking muscular exercise of physiologic magnitude but excessive intensity to cartilage degeneration and cell death in the rabbit knee. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Mechanisms of chemotherapy-induced behavioral toxicities.

    Science.gov (United States)

    Vichaya, Elisabeth G; Chiu, Gabriel S; Krukowski, Karen; Lacourt, Tamara E; Kavelaars, Annemieke; Dantzer, Robert; Heijnen, Cobi J; Walker, Adam K

    2015-01-01

    While chemotherapeutic agents have yielded relative success in the treatment of cancer, patients are often plagued with unwanted and even debilitating side-effects from the treatment which can lead to dose reduction or even cessation of treatment. Common side effects (symptoms) of chemotherapy include (i) cognitive deficiencies such as problems with attention, memory and executive functioning; (ii) fatigue and motivational deficit; and (iii) neuropathy. These symptoms often develop during treatment but can remain even after cessation of chemotherapy, severely impacting long-term quality of life. Little is known about the underlying mechanisms responsible for the development of these behavioral toxicities, however, neuroinflammation is widely considered to be one of the major mechanisms responsible for chemotherapy-induced symptoms. Here, we critically assess what is known in regards to the role of neuroinflammation in chemotherapy-induced symptoms. We also argue that, based on the available evidence, neuroinflammation is unlikely the only mechanism involved in the pathogenesis of chemotherapy-induced behavioral toxicities. We evaluate two other putative candidate mechanisms. To this end we discuss the mediating role of damage-associated molecular patterns (DAMPs) activated in response to chemotherapy-induced cellular damage. We also review the literature with respect to possible alternative mechanisms such as a chemotherapy-induced change in the bioenergetic status of the tissue involving changes in mitochondrial function in relation to chemotherapy-induced behavioral toxicities. Understanding the mechanisms that underlie the emergence of fatigue, neuropathy, and cognitive difficulties is vital to better treatment and long-term survival of cancer patients.

  20. Mechanisms of chemotherapy-induced behavioral toxicities

    Directory of Open Access Journals (Sweden)

    Elisabeth G Vichaya

    2015-04-01

    Full Text Available While chemotherapeutic agents have yielded relative success in the treatment of cancer, patients are often plagued with unwanted and even debilitating side-effects from the treatment which can lead to dose reduction or even cessation of treatment. Common side effects (symptoms of chemotherapy include (i cognitive deficiencies such as problems with attention, memory and executive functioning; (ii fatigue and motivational deficit; and (iii neuropathy. These symptoms often develop during treatment but can remain even after cessation of chemotherapy, severely impacting long-term quality of life. Little is known about the underlying mechanisms responsible for the development of these behavioral toxicities, however, neuroinflammation is widely considered to be one of the major mechanisms responsible for chemotherapy-induced symptoms. Here, we critically assess what is known in regards to the role of neuroinflammation in chemotherapy-induced symptoms. We also argue that, based on the available evidence neuroinflammation is unlikely the only mechanism involved in the pathogenesis of chemotherapy-induced behavioral toxicities. We evaluate two other putative candidate mechanisms. To this end we discuss the mediating role of damage-associated molecular patterns (DAMPs activated in response to chemotherapy-induced cellular damage. We also review the literature with respect to possible alternative mechanisms such as a chemotherapy-induced change in the bioenergetic status of the tissue involving changes in mitochondrial function in relation to chemotherapy-induced behavioral toxicities. Understanding the mechanisms that underlie the emergence of fatigue, neuropathy, and cognitive difficulties is vital to better treatment and long-term survival of cancer patients.

  1. Long-Term Cathodoluminescent Characterization of Thin-Film Oxide Phosphors in a Wide Range of Electron Excitation Densities

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, V D; Felter, T E; Hunt, C E; Dubov, Y G; Chakhovskoi, A G

    2001-05-06

    Long-term processes of cathodoluminescence degradation of thin film phosphors Zn{sub 2}SiO{sub 4}:Ti and Zn{sub 2}GeO{sub 4}:Mn were investigated in a wide range of e-beam energies, current and power densities. The time dependencies describing decreasing of emission intensity have been found. At high-level densities of e-beam irradiation the specific behavior of long-term degradation processes was observed, which is characteristic with rapid degradation at initial stage and slow consequent decrease of intensity. The most probable mechanisms responsible for long-term processes of degradation in investigated phosphors are proposed.

  2. Long-Term Cathodoluminescent Characterization of Thin-Film Oxide Phosphors in a Wide Range of Electron Excitation Densities

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, V D; Felter, T E; Hunt, C E; Dubov, Y G; Chakhovskoy, A G

    2001-04-09

    Long-term processes of cathodoluminescence degradation of thin film phosphors Zn{sub 2}SiO{sub 4}:Ti and Zn{sub 2}GeO{sub 4}:Mn were investigated in a wide range of e-beam energies, current and power densities. The time dependencies describing decreasing of emission intensity have been found. At high-level densities of e-beam irradiation the specific behavior of long-term degradation processes was observed, which is characteristic with rapid degradation at initial stage and slow consequent decrease of intensity. The most probable mechanisms responsible for long-term processes of degradation in investigated phosphors are proposed.

  3. A study of the reported long-term attitudinal and behavioral effects of an eighth-grade environmental education project and the development of an innovation configuration to promote environmental education

    Science.gov (United States)

    Lomino, Jean A.

    Problem. Increasing scientific evidence reveals that this planet is in serious environmental jeopardy. Since 1977, when an international group of K--12 educators met in the USSR and established goals for teaching environmental education worldwide, many schools have endeavored to fulfill these goals through the use of various curricula and teaching strategies. Although some progress has been made, most K--12 public schools have not done enough to meet the demands of environmental problems. In 1996, my co-teacher and I designed and implemented an environmental project, called Mission Environment, that we hoped would help our students develop long-term positive environmental attitudes and behaviors. Purpose. This study is an attempt to discover how effective the Mission Environment project (ME) was in contributing to long-term, positive environmental attitudes and behaviors among the participating students. Methodology. The study used quantitative and qualitative methods. Data were collected by surveying the members of a high-school senior class to determine their current environmental attitudes, behavior, affect, and knowledge. Of the 71 students surveyed, 28 indicated that they had been ME participants during their eighth-grade year (1996--97). The survey data were analyzed using the students' independent samples t test and chi square. Additionally, through student interviews, the study investigated the hypothesis that the teaching methods used during the course of the project contributed to producing these long-term effects. As a result of reflective interviews about the ME project and data from the literature review, a model has been created for a middle-school environmental education project in the form of an Innovation Configuration. This model is presented as part of the results of this study. Findings and conclusions. The results of the statistical analysis of the environmental survey data showed statistically significant differences between the ME

  4. Evidence that limbic neural plasticity in the right hemisphere mediates partial kindling induced lasting increases in anxiety-like behavior: effects of low frequency stimulation (quenching?) on long term potentiation of amygdala efferents and behavior following kindling.

    Science.gov (United States)

    Adamec, R E

    1999-08-21

    Behavioral and physiological effects of partial kindling of the right ventral hippocampus by perforant path (PP) stimulation were investigated in the cat. Partial kindling produced lasting changes in affect (increased defensive response to rats) and predatory attack (decreased pawing and biting attack). Partial kindling also induced long term potentiation (LTP) of amygdala efferent transmission to ventromedial hypothalamus (VMH) and periaqueductal gray (PAG) in left and right hemispheres. LTP of field population spikes evoked in area CA3 by PP stimulation was also observed. LTP was detected using evoked potential methods. These findings parallel previous studies of left PP-CA3 partial kindling. Analysis of covariance removing effects of LTP from behavioral changes suggests that initiation of increased defensiveness at 2 days after completion of partial kindling depended on LTP of left and right amygdalo-VMH and right amygdalo-PAG transmission. From 6 days after kindling onward, increased defensiveness depended on LTP of right amygdalo-PAG transmission. Depotentiation of amygdala efferent LTP by bilateral low frequency amygdala stimulation (LFS) (900 pulses at 1 Hz, once daily for 7 days) selectively reduced LTP in right amygdala efferents. At the same time, defensive, but not predatory attack behavior, was returned to levels seen prior to partial kindling. Both depotentiation and reduction of defensiveness were transient. Defensiveness increased to post-kindling levels by 76 days after LFS. At the same time, LTP was restored in the right amygdalo-PAG pathway. In contrast LTP in the right amygdalo-VMH pathway remained depotentiated. Effects of LFS were not due to damage, as thresholds to evoke amygdala efferent response were unchanged. These findings suggest that lasting change in affect following partial hippocampal kindling depends on LTP of right amygdala efferent transmission to PAG. The findings parallel studies of non-convulsant pharmacological induction of

  5. 构建当代大学生信仰教育长效机制探析%Constructing Long-term Effective Mechanism of Contemporary College Students' Belief Education

    Institute of Scientific and Technical Information of China (English)

    范大平; 陈灿芬; 段振榜

    2012-01-01

    在当今时代背景下,加强大学生信仰教育,构建当代大学生信仰教育长效机制,成为高校思想政治教育的重要课题。目前,我国大学生信仰教育缺乏系统性、前瞻性;民族文化意识不强,没有厚重的历史感和使命感;追求短期效应,没有形成大学生信仰教育长效机制。构建当代大学生信仰教育长效机制,必须立足历史与现实,着眼于实效与长远,综合运用多种方式方法,多维立体地解决当代大学生信仰危机问题。%Under the background of modem era, it has been the significant issue of college ideological and political education to strengthen the belief education of undergraduate and construct long-term effective mechanism of belief educational for contempo- rary undergraduates. At present our country college students' belief education lacks system and prospect; cultural consciousness is not strong, there is not the heavy sense of history and a sense; pursuiting the short-term effect, without the formation of college students' belief education mechanism. Constructing the long-term effective mechanism of belief educational for contemporary un- dergraduates must be based on the history and reality, focus on the effectiveness and long-term, comprehensively use various meth- ods and multidimensionally solute contemporary university students belief crisis.

  6. A Cognitive- Behavioral Therapeutic Program for Patients with Obesity and Binge Eating Disorder: Short- and Long- Term Follow-Up Data of a Prospective Study

    Science.gov (United States)

    Vanderlinden, Johan; Adriaensen, An; Vancampfort, Davy; Pieters, Guido; Probst, Michel; Vansteelandt, Kristof

    2012-01-01

    The goal of this study is to investigate the efficacy of a manualized cognitive-behavioral therapeutic (CBT) approach for patients with obesity and binge eating disorder (BED) on the short and longer term. A prospective study without a control group consisting of three measurements (a baseline measurement and two follow-up assessments up to 5…

  7. Inositol-deficient food augments a behavioral effect of long-term lithium treatment mediated by inositol monophosphatase inhibition: an animal model with relevance for bipolar disorder.

    Science.gov (United States)

    Shtein, Liza; Agam, Galila; Belmaker, R H; Bersudsky, Yuly

    2015-04-01

    Lithium treatment in rodents markedly enhances cholinergic agonists such as pilocarpine. This effect can be reversed in a stereospecific manner by administration of inositol, suggesting that the effect of lithium is caused by inositol monophosphatase inhibition and consequent inositol depletion. If so, inositol-deficient food would be expected to enhance lithium effects. Inositol-deficient food was prepared from inositol-free ingredients. Mice with a homozygote knockout of the inositol monophosphatase 1 gene unable to synthesize inositol endogenously and mimicking lithium-treated animals were fed this diet or a control diet. Lithium-treated wild-type animals were also treated with the inositol-deficient diet or control diet. Pilocarpine was administered after 1 week of treatment, and behavior including seizures was assessed using rating scale. Inositol-deficient food-treated animals, both lithium treated and with inositol monophosphatase 1 knockout, had significantly elevated cholinergic behavior rating and significantly increased or earlier seizures compared with the controls. The effect of inositol-deficient food supports the role of inositol depletion in the effects of lithium on pilocarpine-induced behavior. However, the relevance of this behavior to other more mood-related effects of lithium is not clear.

  8. Multiple Factors in the Long-Term Effectiveness of Contingent Electric Shock Treatment for Self-Injurious Behavior: A Case Example.

    Science.gov (United States)

    Linscheid, Thomas R.; Reichenbach, Heidi

    2002-01-01

    Data are presented to document the initial dramatic reduction in self-injurious behavior and the ongoing effectiveness of contingent electric shock treatment of an adolescent. Positive effects of the intervention are documented, as is information on the interaction of a medical condition, psychoactive mediation status, and staff changes. (Contains…

  9. A Cognitive- Behavioral Therapeutic Program for Patients with Obesity and Binge Eating Disorder: Short- and Long- Term Follow-Up Data of a Prospective Study

    Science.gov (United States)

    Vanderlinden, Johan; Adriaensen, An; Vancampfort, Davy; Pieters, Guido; Probst, Michel; Vansteelandt, Kristof

    2012-01-01

    The goal of this study is to investigate the efficacy of a manualized cognitive-behavioral therapeutic (CBT) approach for patients with obesity and binge eating disorder (BED) on the short and longer term. A prospective study without a control group consisting of three measurements (a baseline measurement and two follow-up assessments up to 5…

  10. Long-term effects of synthetic fibers on concrete pipes

    Science.gov (United States)

    Farrokhi Gozarchi, Sasan

    The studies undertaken by this research were to evaluate the long-term performance and durability of synthetic fiber-reinforced concrete pipes. The target long-term performance is for 9000 hours. Two sets of pipes 8 ft. (2400 mm) long with inside diameters of 24 in. (600 mm) and 36 in. (1200 mm) were manufactured, with a wall thickness of 3 and 4 in., respectively. The pipes were produced based on ASTM C76, for a Class III type with a Wall B. The two set of pipes included RCP's (as control) and SYN-FRCP's. The SYN-FRCP's had several fiber dosages ranging from 6 lb/yd3 (3.5 kg/m 3) to 12 lb/yd3 (7.0 kg/m3) in order to evaluate the long-term performance of synthetic fiber-reinforced concrete pipes. The pipes were pre-cracked until the first visible crack was observed in the three-edge bearing test. As a result, the sustained load simulated, was calculated from the Peak D-load observed; and also the appropriate fiber dosages required for the 24. in (600 mm) and 36 in. (900 mm) pipes were obtained. Three of the 24 in. and three of the 36 in. pipes were installed in 7 ft. (2100 mm) and 8 ft. (2400 mm) wide trenches with 16 ft. (4800 mm) and 18 ft. (5500 mm) of cover respectively. The pipe was initially backfilled with native soil up to 2 ft. (600 mm) and 4 ft. (1200 mm) over the top of the pipe then backfilled again with pea-gravel weighing 100 lb/ft3, to a height of 14ft. to simulate the sustained loading. A type two installation was used during the development of the test setup. Once the long-term test set up was complete, the data was immediately recorded, and vertical deflections were observed from the time-dependent behavior of the pipes. It was observed from results obtained from the three-edge bearing test, that synthetic fibers improve the mechanical properties of concrete pipes, in dry-cast manufacturing. Also, it was observed from the time-dependent deformation, that there was no significant deformation of SYN-FRCP, while the shear capacity was enhanced. Based

  11. Long-term correlates of childhood abuse among adults with severe mental illness: adult victimization, substance abuse, and HIV sexual risk behavior.

    Science.gov (United States)

    Meade, Christina S; Kershaw, Trace S; Hansen, Nathan B; Sikkema, Kathleen J

    2009-04-01

    The prevalence of childhood sexual and physical abuse among persons with severe mental illness (SMI) is disproportionately high. Adults with SMI also engage in high rates of HIV risk behaviors. This study examined the association between childhood abuse and adult victimization, substance abuse, and lifetime HIV sexual risk in a sample of 152 adults with SMI receiving community mental health services. Structured interviews assessed psychiatric, psychosocial, and behavioral risk factors. Seventy percent reported childhood physical and/or sexual abuse, and 32% reported both types of abuse. Participants with childhood abuse were more likely to report adult victimization and greater HIV risk. A structural equation model found that childhood abuse was directly and indirectly associated with HIV risk through drug abuse and adult vicitimization. Integrated treatment approaches that address interpersonal violence and substance abuse may be necessary for HIV risk reduction in this population.

  12. Long-term (15 mo) dietary supplementation with pomegranates from Oman attenuates cognitive and behavioral deficits in a transgenic mice model of Alzheimer's disease.

    Science.gov (United States)

    Subash, Selvaraju; Braidy, Nady; Essa, Musthafa Mohamed; Zayana, Al-Buraiki; Ragini, Vaishnav; Al-Adawi, Samir; Al-Asmi, Abdullah; Guillemin, Gilles J

    2015-01-01

    Transgenic (Tg) mice, which possess an amyloid precursor protein (APP) gene mutation, develop extracellular amyloid β (Aβ) deposition in the brain, and severe memory and behavioral deficits with age. These mice serve as an important animal model for testing the efficacy of novel drug candidates for the treatment and management of symptoms of Alzheimer's disease (AD). Several reports have suggested that oxidative stress is the underlying cause of Aβ neurotoxicity in AD. Pomegranates contain very high levels of antioxidants and several medicinal properties that may be useful for improving quality of life in individuals with AD. The aim of this study was to investigate the effect of dietary supplementation of Omani pomegranate extract on memory, anxiety, and learning skills in an AD mouse model possessing the double Swedish APP mutation (APPsw/Tg2576). The experimental groups of APP-Tg mice from the age of 4 mo were fed a custom mixed diet (pellets) containing 4% pomegranate. We assessed spatial memory and learning ability, psychomotor coordination, and anxiety-related behavior in Tg and wild-type mice at the age of 4 to 5 mo and 18 to 19 mo using the Morris water maze test, rotarod performance test, elevated plus-maze test, and open field test. APPsw/Tg2576 mice that were fed a standard chow diet without pomegranates showed significant memory deficits, increased anxiety-related behavior, and severe impairment in spatial learning ability, position discrimination learning ability, and motor coordination compared with the wild-type mice on the same diet, at the age of 18 to 19 mo. In contrast, APPsw/Tg2576 mice that were fed a diet containing 4% pomegranates showed significant improvements in memory, learning, locomotor function, as well as reduction in anxiety, compared with APPsw/Tg2576 mice fed the standard chow diet. Our results suggest that dietary supplementation with pomegranates may slow the progression of cognitive and behavioral impairments in AD. Copyright

  13. Solid State Characterizations of Long-Term Leached Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Asmussen, Robert M.; Pearce, Carolyn I.; Parker, Kent E.; Miller, Brian W.; Lee, Brady D.; Buck, Edgar C.; Washton, Nancy M.; Bowden, Mark E.; Lawter, Amanda R.; McElroy, Erin M.; Serne, R Jeffrey

    2016-09-30

    This report describes the results from the solid phase characterization of six Cast Stone monoliths from the extended leach tests recently reported on (Serne et al 2016),that were selected for characterization using multiple state-of-the-art approaches. The Cast Stone samples investigated were leached for > 590 d in the EPA Method 1315 test then archived for > 390 d in their final leachate. After reporting the long term leach behavior of the monoliths, it was suggested that physical changes to the waste form samples and a depleting inventory of contaminants of potential concern may mean that effective diffusivity calculations past 63 d should not be used to t accurately represent long-term waste form behavior. Understanding the physical and chemical mechanisms that occur in the Cast Stone during the long-term leaching process is thus imperative to support long term modelling of cementitious waste form performance. These novel investigations provide an initial arsenal of techniques which can be utilized to perform such Cast Stone solid phase characterization work, which in turn can support upcoming performance assessment maintenance. The work was performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to characterize several properties of the long term leached Cast Stone monolith samples:

  14. Long-term psychosocial behavioral outcomes in children following anesthesia: A comparison of the effects of general versus regional anesthesia on term infants delivered by elective cesarean section

    Directory of Open Access Journals (Sweden)

    Aouni Alameddine

    2013-01-01

    Full Text Available Background: Data on the effects of general anesthesia on the fetal and neonatal brain are limited. Animal studies demonstrated that anesthetic agents leave their consequences in the form of learning and memory deficits. The effects of propofol on the fetal neurodevelopment are not clear yet. Materials and Methods: This is a telephone-based questionnaire survey that addressed the effect of general anesthesia by propofol during cesarean section at term with no perinatal complications on the psychosocial behavior of children at 8-10 years of age compared with children having same characteristics except for delivery under neuraxial anesthesia using the Pediatric Symptom Checklist as a score. Results: A total of 187 children were born at term between January 1, 2002 and December 31, 2004 with no perinatal distress under induction of general anesthesia by propofol. 66 children (35.3% were lost to follow-up and parents of two children (1.1% refused to participate. A total of 189 children were included in the study: 119 were born by cesarean section under general anesthesia and 70 were born by cesarean section under neuraxial block. The incidence of psychosocial behavior impairment at 8-10 years of age was not found to be affected by the mode of anesthesia during delivery by cesarean section nor by neonatal nor parental characteristics. Conclusion: Exposure to propofol as an induction agent for general anesthesia or cesarean section does not seem to increase the psychosocial behavior disorder development risk at 8-10 years of age.

  15. Long-term prevention of Alzheimer’s disease-like behavioral deficits in PDAPP mice carrying a mutation in Asp664

    Science.gov (United States)

    Galvan, Veronica; Zhang, Junli; Gorostiza, Olivia F.; Banwait, Surita; Huang, Wei; Ataie, Marina; Tang, Huidong; Bredesen, Dale E.

    2009-01-01

    The deficits of Alzheimer’s disease (AD) are believed to result, at least in part, from neurotoxicity of β-amyloid (Aβ), a set of 38–43 amino acid fragments derived from the β-amyloid precursor protein (APP). In addition, APP generates the APP-C31 and Jcasp toxic fragments intracellularly by cleavage at Asp664. We reported that mutation of Asp664 to A in a FAD-human APP transgene prevented AD-like deficits but did not affect Aβ production or deposition in PDAPP mice, arguing that D664A plays a crucial role in the generation of AD-like deficits. Whether D664A simply delays or completely prevents AD-like deficits, however, remained undefined. To address this question, we performed behavioral studies longitudinally on a pretrained mouse cohort at 9 and 13 months of age. While behavioral deficits were present in PDAPP mice, performance of Tg PDAPP(D664A) mice was not significantly different from non-Tg littermates’ across all ages tested. Moreover, aberrant patterns in non-cognitive components of behavior in PDAPP mice were ameliorated in PDAPP(D664A) animals as well. A trend towards poorer retention at 9 mo and poorer learning at 13 mo that did not reach statistical significance was observed in PDAPP(D664A) mice. These results support and extend recent studies showing that cleavage of APP at Asp664 (or protein-protein interactions dependent on Asp664) is a crucial event in the generation of AD-like deficits in PDAPP mice. Our results thus further demonstrate that the D664A mutation either completely precludes, or markedly delays (beyond 13 mo) the appearance of AD-like deficits in this mouse model of AD. PMID:18485495

  16. Long-term potentiation and long-term depression: a clinical perspective

    Directory of Open Access Journals (Sweden)

    Timothy V.P. Bliss

    2011-01-01

    Full Text Available Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke.

  17. Long term perfusion system supporting adipogenesis.

    Science.gov (United States)

    Abbott, Rosalyn D; Raja, Waseem K; Wang, Rebecca Y; Stinson, Jordan A; Glettig, Dean L; Burke, Kelly A; Kaplan, David L

    2015-08-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogenesis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight.

  18. Effect of Tungsten on Long-Term Microstructural Evolution and Impression Creep Behavior of 9Cr Reduced Activation Ferritic/Martensitic Steel

    Science.gov (United States)

    Thomas Paul, V.; Vijayanand, V. D.; Sudha, C.; Saroja, S.

    2017-01-01

    The present study describes the changes in the creep properties associated with microstructural evolution during thermal exposures to near service temperatures in indigenously developed reduced activation ferritic-martensitic steels with varying tungsten (1 and 1.4 wt pct W) contents. The creep behavior has been studied employing impression creep (IC) test, and the changes in impression creep behavior with tungsten content have been correlated with the observed microstructures. The results of IC test showed that an increase in 0.4 pct W decreases the creep rate to nearly half the value. Creep strength of 1.4 pct W steel showed an increase in steels aged for short durations which decreased as aging time increased. The microstructural changes include coarsening of precipitates, reduction in dislocation density, changes in microchemistry, and formation of new phases. The formation of various phases and their volume fractions have been predicted using the JMatPro software for the two steels and validated by experimental methods. Detailed transmission electron microscopy analysis shows coarsening of precipitates and formation of a discontinuous network of Laves phase in 1.4 W steel aged for 10,000 hours at 823 K (550 °C) which is in agreement with the JMatPro simulation results.

  19. Effect of Tungsten on Long-Term Microstructural Evolution and Impression Creep Behavior of 9Cr Reduced Activation Ferritic/Martensitic Steel

    Science.gov (United States)

    Thomas Paul, V.; Vijayanand, V. D.; Sudha, C.; Saroja, S.

    2016-10-01

    The present study describes the changes in the creep properties associated with microstructural evolution during thermal exposures to near service temperatures in indigenously developed reduced activation ferritic-martensitic steels with varying tungsten (1 and 1.4 wt pct W) contents. The creep behavior has been studied employing impression creep (IC) test, and the changes in impression creep behavior with tungsten content have been correlated with the observed microstructures. The results of IC test showed that an increase in 0.4 pct W decreases the creep rate to nearly half the value. Creep strength of 1.4 pct W steel showed an increase in steels aged for short durations which decreased as aging time increased. The microstructural changes include coarsening of precipitates, reduction in dislocation density, changes in microchemistry, and formation of new phases. The formation of various phases and their volume fractions have been predicted using the JMatPro software for the two steels and validated by experimental methods. Detailed transmission electron microscopy analysis shows coarsening of precipitates and formation of a discontinuous network of Laves phase in 1.4 W steel aged for 10,000 hours at 823 K (550 °C) which is in agreement with the JMatPro simulation results.

  20. 论少数民族地区社会稳定长效机制体系构建%On the Construction of Long-term Mechanism for the Social Stability of Ethnic Minority Areas

    Institute of Scientific and Technical Information of China (English)

    高翔

    2012-01-01

    The long-term mechanism for the social stability of ethnic minority areas is constituted by four mechanism systems: mechanism of stability promotion by national harmony, mechanism of stability promotion by development, mechanism of stability promotion by innovation of social management, and mechanism of sta- bility preservation by the rule of law. These mechanism systems are a series of comprehensive governancemechanisms that fundamentally addresses the main elements that affect the social stability ol the ethmc minori- ty areas, and important mechanisms that maintain the ethnic people's fundamental interests, ensure the long- term stability of ethnic areas and safeguard national security and border security. They can optimize the envi- ronmental function of economical and social development of ethnic areas for the long term and promote harmo- nious socialism construction of ethnic areas.%少数民族地区社会稳定长效机制体系由四个机制系统构成:一是以民族和谐促稳定机制,二是以发展促稳定机制,三是以社会管理创新促稳定机制,四是以法治保稳定机制。这一机制体系是从源头上、从根本上解决影响民族地区社会稳定的主要因素的综合治理机制,是维护民族地区人民群众根本利益和确保民族地区长治久安、维护国家安全以及边疆安全的重要机制,从而长期优化民族地区经济与社会发展环境功能、促进民族地区社会主义和谐社会建设。

  1. Asthma Medicines: Long-Term Control

    Science.gov (United States)

    ... Size Email Print Share Asthma Medicines: Long-term Control Page Content Article Body Corticosteroids Synthetic versions of ... form, they are used exclusively for long-term control; they are not very effective for acute symptoms. ...

  2. Long term complications after radical cystoprostatectomy with ...

    African Journals Online (AJOL)

    Long term complications after radical cystoprostatectomy with orthotopic diversion in male ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING ... Objective: To evaluate the long-term outcomes beyond 1 year, both ...

  3. Long-term plasticity in interneurons of the dentate gyrus

    OpenAIRE

    Ross, Stephen T.; Soltesz, Ivan

    2001-01-01

    Single interneurons influence thousands of postsynaptic principal cells, and the control of interneuronal excitability is an important regulator of the computational properties of the hippocampus. However, the mechanisms underlying long-term alterations in the input–output functions of interneurons are not fully understood. We report a mechanism of interneuronal plasticity that leads to the functional enhancement of the gain of glutamatergic inputs in the absence of long-term potentiation of ...

  4. Nutrition, weight gain and eating behavior in pregnancy: a review of experimental evidence for long-term effects on the risk of obesity in offspring.

    Science.gov (United States)

    Sen, Sarbattama; Carpenter, Arielle H; Hochstadt, Jessica; Huddleston, Juli Y; Kustanovich, Vladimir; Reynolds, Ashley A; Roberts, Susan

    2012-08-20

    Obesity has reached near epidemic proportions in the developed world. As reproductive age women are a part of this trend, the effect of maternal obesity on the developing fetus must be investigated. In this review, we evaluated the experimental evidence relating maternal nutritional status and eating behavior before and during pregnancy on the risk of obesity in the offspring. The studies were compiled and selected based on their methodologies, study design and relevance. The analyzed studies were compiled to quantify, if possible, the relationship between maternal and offspring weight. Descriptive and observational studies were also included if they were seminal in the field. Based on the current data, maternal obesity is a critical factor exacerbating multigenerational obesity. Mechanistic studies, mainly in animals, have identified potential areas for intervention which might limit transmission of adverse risk factors for obesity from mothers to infants during pregnancy.

  5. How domain growth is implemented determines the long-term behavior of a cell population through its effect on spatial correlations

    Science.gov (United States)

    Ross, Robert J. H.; Baker, R. E.; Yates, C. A.

    2016-07-01

    Domain growth plays an important role in many biological systems, and so the inclusion of domain growth in models of these biological systems is important to understanding how these systems function. In this work we present methods to include the effects of domain growth on the evolution of spatial correlations in a continuum approximation of a lattice-based model of cell motility and proliferation. We show that, depending on the way in which domain growth is implemented, different steady-state densities are predicted for an agent population. Furthermore, we demonstrate that the way in which domain growth is implemented can result in the evolution of the agent density depending on the size of the domain. Continuum approximations that ignore spatial correlations cannot capture these behaviors, while those that account for spatial correlations do. These results will be of interest to researchers in developmental biology, as they suggest that the nature of domain growth can determine the characteristics of cell populations.

  6. Phase behavior of fluorocarbon and hydrocarbon double-chain hydroxylated and galactosylated amphiphiles and bolaamphiphiles. Long-term shelf-stability of their liposomes.

    Science.gov (United States)

    Clary, L; Gadras, C; Greiner, J; Rolland, J P; Santaella, C; Vierling, P; Gulik, A

    1999-06-01

    This paper describes the morphological characterization, by freeze-fracture electron microscopy, and the thermotropic phase behavior, by differential scanning calorimetry and/or X-ray scattering, of aqueous dispersions of various hydroxylated and galactosylated double-chain amphiphiles and bolaamphiphiles, several of them containing one or two hydrophobic fluorocarbon chains. Colloidal systems are observed in water with the hydroxylated hydrocarbon or fluorocarbon bolaamphiphiles only when they are dispersed with a co-amphiphile such as rac-1,2-dimyristoylphosphatidylcholine (DMPC) or rac-1,2-distearoylphosphatidylcholine (DSPC). Liposomes are formed providing the relative content of bolaamphiphiles does not exceed 20% mol. Most of these liposomes can be thermally sterilized and stored at room temperature for several months without any significant modification of their size and size distribution. The hydrocarbon galactosylated bolaamphiphile HO[C24][C12]Gal forms in water a lamellar phase (the gel to liquid-crystal phase transition is complete at 45 degrees C) and a Im3m cubic phase above 47 degrees C. The fluorocarbon HO[C24][F6C5]Gal analog displays a more complex and metastable phase behavior. The fluorinated non-bolaform galactosylated [F8C7][C16]AEGal and SerGal amphiphiles form lamellar phases in water. Low amounts (10% molar ratio) of the HO[C24][F6C5]Gal or HO[C24][C12]Gal bolaamphiphiles or of the single-headed [F8C7][C16]AEGal improve substantially the shelf-stability of reference phospholipon/cholesterol 2/1 liposomes. These liposomes when co-formulated with a single-headed amphiphile from the SerGal series are by far less stable.

  7. Practice and Experience of the Establishment of Long Term Mechanism of Continuous Quality Improvement%建立医疗质量持续改进长效机制的实践与体会

    Institute of Scientific and Technical Information of China (English)

    谭天林; 欧兵玺; 廖世川; 罗力; 李雪

    2011-01-01

    探讨建立医疗质量持续改进长效机制,确保患者医疗安全,提高患者满意度.坚持将健全组织、完善制度、优化流程、全员培训、全面监控、加强沟通、整改到位等措施,贯穿于基础质量控制、环节质量控制和终末质量控3个环节,是建立医疗质量持续改进长效机制的有效方法.%The establishment of long-term mechanism for continuous improvement of health care quality is explored to ensure the safety of patients, and to improve patient satisfaction. Adhering to a sound organization, improving the system, streamlining business process, training all staff, and enhancing comprehensive monitoring and communication are needed in place corrective measures, such as quality control throughout the base, part of quality control and quality control of the three terminal links, and are effective ways of continuous quality improvement of establishing long-term mechanism.

  8. Non-sedation versus sedation with a daily wake-up trial in critically ill patients recieving mechanical ventilation - effects on long-term cognitive function

    DEFF Research Database (Denmark)

    Nedergaard, Helene Korvenius; Jensen, Hanne Irene; Stylsvig, Mette;

    2016-01-01

    , including 200 patients. Inclusion criteria will be adult patients who are intubated and on mechanical ventilation with an expected duration of more than 24 hours. Exclusion criteria will be patients who are comatose at admission and patients with conditions requiring therapeutic coma (i.e., severe head...... trauma, status epilepticus, patients treated with therapeutic hypothermia and patients with severe hypoxia). The experimental intervention will be non-sedation supplemented with pain management during mechanical ventilation. The control intervention will be sedation with a daily wake-up attempt...

  9. Testosterone has a long-term effect on primary sex ratio of first eggs in pigeons-in search of a mechanism

    NARCIS (Netherlands)

    Goerlich, V. C.; Dijkstra, C.; Schaafsma, S. M.; Groothuis, T. G. G.

    2009-01-01

    Despite accumulating evidence that birds, in which females are the heterogametic sex, are able to manipulate primary offspring sex ratio, the underlying mechanism remains elusive. Steroid hormones. which govern female reproduction and are also accumulated by the developing follicle could potentially

  10. Paddy Soil Stability and Mechanical Properties as Affected by Long-Term Application of Chemical Fertilizer and Animal Manure in Subtropical China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wet stability, penetration resistance (PR), and tensile strength (TS) of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil stabilization. The treatments included no fertilization (CK), normal chemical fertilization (NPK), double the NPK application rates (2NPK), and NPK mixed with organic manure (NPK+OM). Compared with CK, fertilization increased soil organic carbon (SOC) and soil porosity. The results of soil aggregate fragmentation degree (SAFD) showed that fast wetting by water was the key fragmentation mechanism. Among the treatments, the NPK+OM treatment had the largest size of water-stable aggregates and greatest normal mean weight diameter (NMWD) (P ≤ 0.05), but the lowest PR and TS in both cultivated horizon (Ap) and plow pan. The CK and 2NPK treatments were measured with PR > 2.0 MPa and friability index < 0.20,respectively, in the Ap horizon, suggesting that the soils was mechanically unfavourable to root growth and tillage. In the plow pan, the fertilization treatments had greater TS and PR than in CK. TS and PR of the tested soil aggregates were negatively correlated to SOC content and soil porosity. This study suggested that chemical fertilization could cause deterioration of mechanical properties while application of organic manure could improve soil stability and mechanical properties.

  11. Long term testing of PSI-membranes

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J.; Brack, H.P.; Geiger, F.; Buechi, F.N.; Tsukada, A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

  12. Sleep facilitates long-term face adaptation.

    Science.gov (United States)

    Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

    2013-10-22

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation--which are usually not considered to play a relevant role in mnemonic processes--with learning and memory, and at the same time reveal a new function of sleep in cognition.

  13. Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis.

    Science.gov (United States)

    Wang, Yin; Chen, Si; Shi, Jiawei; Li, Geng; Dong, Nianguo

    2016-03-01

    This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age. © The Author 2015. Published by

  14. The Effect of Long-Term Impact of Elevated Temperature on Changes in Microstructure and Mechanical Properties of HR3C Steel

    Directory of Open Access Journals (Sweden)

    Zieliński A.

    2016-06-01

    Full Text Available The HR3C is a new steel for pressure components used in the construction of boilers with supercritical working parameters. In the HR3C steel, due to adding Nb and N, the compounds such as MX, CrNbN and M23C6 precipitate during service at elevated temperature, resulting in changes in mechanical properties. This paper presents the results of microstructure investigations after ageing at 650, 700 and 750 °C for 5,000 h. The microstructure investigations were carried out using scanning and transmission electron microscopy. The qualitative and quantitative identification of the existing precipitates was carried out using X-ray analysis of phase composition. The effect elevated temperature on microstructure and mechanical properties of the examined steel was described.

  15. Long-Term Recency in Anterograde Amnesia.

    Directory of Open Access Journals (Sweden)

    Deborah Talmi

    Full Text Available Amnesia is usually described as an impairment of a long-term memory (LTM despite an intact short-term memory (STM. The intact recency effect in amnesia had supported this view. Although dual-store models of memory have been challenged by single-store models based on interference theory, this had relatively little influence on our understanding and treatment of amnesia, perhaps because the debate has centred on experiments in the neurologically intact population. Here we tested a key prediction of single-store models for free recall in amnesia: that people with amnesia will exhibit a memory advantage for the most recent items even when all items are stored in and retrieved from LTM, an effect called long-term recency. People with amnesia and matched controls studied, and then free-recalled, word lists with a distractor task following each word, including the last (continual distractor task, CDFR. This condition was compared to an Immediate Free Recall (IFR, no distractors and a Delayed Free Recall (DFR, end-of-list distractor only condition. People with amnesia demonstrated the full long-term recency pattern: the recency effect was attenuated in DFR and returned in CDFR. The advantage of recency over midlist items in CDFR was comparable to that of controls, confirming a key prediction of single-store models. Memory deficits appeared only after the first word recalled in each list, suggesting the impairment in amnesia may emerge only as the participant's recall sequence develops, perhaps due to increased susceptibility to output interference. Our findings suggest that interference mechanisms are preserved in amnesia despite the overall impairment to LTM, and challenge strict dual-store models of memory and their dominance in explaining amnesia. We discuss the implication of our findings for rehabilitation.

  16. Long-Term Recency in Anterograde Amnesia.

    Science.gov (United States)

    Talmi, Deborah; Caplan, Jeremy B; Richards, Brian; Moscovitch, Morris

    2015-01-01

    Amnesia is usually described as an impairment of a long-term memory (LTM) despite an intact short-term memory (STM). The intact recency effect in amnesia had supported this view. Although dual-store models of memory have been challenged by single-store models based on interference theory, this had relatively little influence on our understanding and treatment of amnesia, perhaps because the debate has centred on experiments in the neurologically intact population. Here we tested a key prediction of single-store models for free recall in amnesia: that people with amnesia will exhibit a memory advantage for the most recent items even when all items are stored in and retrieved from LTM, an effect called long-term recency. People with amnesia and matched controls studied, and then free-recalled, word lists with a distractor task following each word, including the last (continual distractor task, CDFR). This condition was compared to an Immediate Free Recall (IFR, no distractors) and a Delayed Free Recall (DFR, end-of-list distractor only) condition. People with amnesia demonstrated the full long-term recency pattern: the recency effect was attenuated in DFR and returned in CDFR. The advantage of recency over midlist items in CDFR was comparable to that of controls, confirming a key prediction of single-store models. Memory deficits appeared only after the first word recalled in each list, suggesting the impairment in amnesia may emerge only as the participant's recall sequence develops, perhaps due to increased susceptibility to output interference. Our findings suggest that interference mechanisms are preserved in amnesia despite the overall impairment to LTM, and challenge strict dual-store models of memory and their dominance in explaining amnesia. We discuss the implication of our findings for rehabilitation.

  17. Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

    Science.gov (United States)

    Dent, Paul; Deng, Bin; Goodisman, Jerry; Peterson, Charles M.; Narsipur, Sriram; Chaiken, J.

    2016-04-01

    A new device incorporating a new algorithm and measurement process allows simultaneous noninvasive in vivo monitoring of intravascular plasma volume and red blood cell volume. The purely optical technique involves probing fingertip skin with near infrared laser light and collecting the wavelength shifted light, that is, the inelastic emission (IE) which includes the unresolved Raman and fluorescence, and the un-shifted emission, that is, the elastic emission (EE) which includes both the Rayleigh and Mie scattered light. Our excitation and detection geometry is designed so that from these two simultaneous measurements we can calculate two parameters within the single scattering regime using radiation transfer theory, the intravascular plasma volume fraction and the red blood cell volume fraction. Previously calibrated against a gold standard FDA approved device, 2 hour monitoring sessions on three separate occasions over a three week span for a specific, motionless, and mostly sleeping individual produced 3 records containing a total of 5706 paired measurements of hematocrit and plasma volume. The average over the three runs, relative to the initial plasma volume taken as 100%, of the plasma volume±1σ was 97.56+/-0.55 or 0.56%.For the same three runs, the average relative hematocrit (Hct), referenced to an assumed initial value of 28.35 was 29.37+/-0.12 or stable to +/-0.4%.We observe local deterministic circulation effects apparently associated with the pressure applied by the finger probe as well as longer timescale behavior due to normal ebb and flow of internal fluids due to posture changes and tilt table induced gravity gradients.

  18. The long-term mechanical integrity of non-reinforced PEEK-OPTIMA polymer for demanding spinal applications: experimental and finite-element analysis.

    Science.gov (United States)

    Ferguson, Stephen J; Visser, Judith M A; Polikeit, Anne

    2006-02-01

    Polyetheretherketone (PEEK) is a novel polymer with potential advantages for its use in demanding orthopaedic applications (e.g. intervertebral cages). However, the influence of a physiological environment on the mechanical stability of PEEK has not been reported. Furthermore, the suitability of the polymer for use in highly stressed spinal implants such as intervertebral cages has not been investigated. Therefore, a combined experimental and analytical study was performed to address these open questions. A quasi-static mechanical compression test was performed to compare the initial mechanical properties of PEEK-OPTIMA polymer in a dry, room-temperature and in an aqueous, 37 degrees C environment (n=10 per group). The creep behaviour of cylindrical PEEK polymer specimens (n=6) was measured in a simulated physiological environment at an applied stress level of 10 MPa for a loading duration of 2000 hours (12 weeks). To compare the biomechanical performance of different intervertebral cage types made from PEEK and titanium under complex loading conditions, a three-dimensional finite element model of a functional spinal unit was created. The elastic modulus of PEEK polymer specimens in a physiological environment was 1.8% lower than that of specimens tested at dry, room temperature conditions (Pcreep test showed an average creep strain of less than 0.1% after 2000 hours of loading. The finite element analysis demonstrated high strain and stress concentrations at the bone/implant interface, emphasizing the importance of cage geometry for load distribution. The stress and strain maxima in the implants were well below the material strength limits of PEEK. In summary, the experimental results verified the mechanical stability of the PEEK-OPTIMA polymer in a simulated physiological environment, and over extended loading periods. Finite element analysis supported the use of PEEK-OPTIMA for load-bearing intervertebral implants.

  19. Short and long-term strength of shale rocks

    Science.gov (United States)

    Rybacki, Erik; Dresen, Georg

    2016-04-01

    Stimulation of oil and gas bearing shales commonly utilizes advanced hydraulic fracturing techniques to enhance the production rate. Successful hydrofrac campaigns depend on the geomechanical properties of the reservoir. For example, the short term strength and brittleness may control the hydraulic breakdown pressure and borehole stability. The long term creep properties may determine the closure rate of hydraulically induced fractures, for example by proppant embedment. We performed a series of mechanical tests on shales with different mineral content, porosity and maturity. Cylindrical samples of 1-5 cm in diameter and 2-10 cm in length were deformed at confining pressures of 0.1 - 400 MPa and temperatures of 25°-400°C in constant strain rate and constant stress mode in order to evaluate the influence of loading conditions and composition on their strength and ductility. Short-term constant strain rate tests show that, at fixed loading direction with respect to bedding orientation, the peak strength and Young's modulus vary with mineral content, humidity and porosity, but depend also on applied pressure, temperatu