Identifying facilitators and barriers to physical activity for adults with Down syndrome.

PubMed

Mahy, J; Shields, N; Taylor, N F; Dodd, K J

2010-09-01

Adults with Down syndrome are typically sedentary, and many do not participate in the recommended levels of physical activity per week. The aim of this study was to identify the facilitators and barriers to physical activity for this group. Semi-structured interviews were conducted to elicit the views of adults with Down syndrome and their support people about what factors facilitate physical activity and what factors are barriers to activity. A sample of 18 participants (3 men, 15 women) was recruited through two agencies providing services for adults with disabilities; six participants were adults with Down syndrome and 12 participants were support people (four were parents of adults with Down syndrome and eight participants were employed by day programmes attended by the adults with Down syndrome). The interviews were recorded, transcribed verbatim and independently coded by two researchers. Three themes around facilitators to physical activity were identified: (1) support from others; (2) that the physical activity was fun or had an interesting purpose; and (3) routine and familiarity. Three themes around barriers were also identified: (1) lack of support; (2) not wanting to engage in physical activity; and (3) medical and physiological factors. The results suggest that support people play a key role, both as facilitators and barriers, in the participation by adults with Down syndrome in physical activity. Many of the barriers and facilitators of activity for adults with Down syndrome indentified are similar to those reported for adults without impairment. Our findings are also consistent with established theories in the field of health behaviour change.

The gamma cycle.

PubMed

Fries, Pascal; Nikolić, Danko; Singer, Wolf

2007-07-01

Activated neuronal groups typically engage in rhythmic synchronization in the gamma-frequency range (30-100 Hz). Experimental and modeling studies demonstrate that each gamma cycle is framed by synchronized spiking of inhibitory interneurons. Here, we review evidence suggesting that the resulting rhythmic network inhibition interacts with excitatory input to pyramidal cells such that the more excited cells fire earlier in the gamma cycle. Thus, the amplitude of excitatory drive is recoded into phase values of discharges relative to the gamma cycle. This recoding enables transmission and read out of amplitude information within a single gamma cycle without requiring rate integration. Furthermore, variation of phase relations can be exploited to facilitate or inhibit exchange of information between oscillating cell assemblies. The gamma cycle could thus serve as a fundamental computational mechanism for the implementation of a temporal coding scheme that enables fast processing and flexible routing of activity, supporting fast selection and binding of distributed responses. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Phenazine redox cycling enhances anaerobic survival in Pseudomonas aeruginosa by facilitating generation of ATP and a proton-motive force

PubMed Central

Glasser, Nathaniel R.; Kern, Suzanne E.

2014-01-01

Summary While many studies have explored the growth of Pseudomonas aeruginosa, comparatively few have focused on its survival. Previously, we reported that endogenous phenazines support the anaerobic survival of P. aeruginosa, yet the physiological mechanism underpinning survival was unknown. Here, we demonstrate that phenazine redox cycling enables P. aeruginosa to oxidize glucose and pyruvate into acetate, which promotes survival by coupling acetate and ATP synthesis through the activity of acetate kinase. By measuring intracellular NAD(H) and ATP concentrations, we show that survival is correlated with ATP synthesis, which is tightly coupled to redox homeostasis during pyruvate fermentation but not during arginine fermentation. We also show that ATP hydrolysis is required to generate a proton-motive force using the ATP synthase complex during fermentation. Together, our results suggest that phenazines enable maintenance of the proton-motive force by promoting redox homeostasis and ATP synthesis. This work demonstrates the more general principle that extracellular redox-active molecules, such as phenazines, can broaden the metabolic versatility of microorganisms by facilitating energy generation. PMID:24612454

The Effect of "Rogue" Active Regions on the Solar Cycle

NASA Astrophysics Data System (ADS)

Nagy, Melinda; Lemerle, Alexandre; Labonville, François; Petrovay, Kristóf; Charbonneau, Paul

2017-11-01

The origin of cycle-to-cycle variations in solar activity is currently the focus of much interest. It has recently been pointed out that large individual active regions with atypical properties can have a significant impact on the long-term behavior of solar activity. We investigate this possibility in more detail using a recently developed 2×2D dynamo model of the solar magnetic cycle. We find that even a single "rogue" bipolar magnetic region (BMR) in the simulations can have a major effect on the further development of solar activity cycles, boosting or suppressing the amplitude of subsequent cycles. In extreme cases, an individual BMR can completely halt the dynamo, triggering a grand minimum. Rogue BMRs also have the potential to induce significant hemispheric asymmetries in the solar cycle. To study the effect of rogue BMRs in a more systematic manner, a series of dynamo simulations were conducted, in which a large test BMR was manually introduced in the model at various phases of cycles of different amplitudes. BMRs emerging in the rising phase of a cycle can modify the amplitude of the ongoing cycle, while BMRs emerging in later phases will only affect subsequent cycles. In this model, the strongest effect on the subsequent cycle occurs when the rogue BMR emerges around cycle maximum at low latitudes, but the BMR does not need to be strictly cross-equatorial. Active regions emerging as far as 20° from the equator can still have a significant effect. We demonstrate that the combined effect of the magnetic flux, tilt angle, and polarity separation of the BMR on the dynamo is via their contribution to the dipole moment, δ D_{BMR}. Our results indicate that prediction of the amplitude, starting epoch, and duration of a cycle requires an accurate accounting of a broad range of active regions emerging in the previous cycle.

Long-Range Solar Activity Predictions: A Reprieve from Cycle #24's Activity

NASA Technical Reports Server (NTRS)

Richon, K.; Schatten, K.

2003-01-01

We discuss the field of long-range solar activity predictions and provide an outlook into future solar activity. Orbital predictions for satellites in Low Earth Orbit (LEO) depend strongly on exospheric densities. Solar activity forecasting is important in this regard, as the solar ultra-violet (UV) and extreme ultraviolet (EUV) radiations inflate the upper atmospheric layers of the Earth, forming the exosphere in which satellites orbit. Rather than concentrate on statistical, or numerical methods, we utilize a class of techniques (precursor methods) which is founded in physical theory. The geomagnetic precursor method was originally developed by the Russian geophysicist, Ohl, using geomagnetic observations to predict future solar activity. It was later extended to solar observations, and placed within the context of physical theory, namely the workings of the Sun s Babcock dynamo. We later expanded the prediction methods with a SOlar Dynamo Amplitude (SODA) index. The SODA index is a measure of the buried solar magnetic flux, using toroidal and poloidal field components. It allows one to predict future solar activity during any phase of the solar cycle, whereas previously, one was restricted to making predictions only at solar minimum. We are encouraged that solar cycle #23's behavior fell closely along our predicted curve, peaking near 192, comparable to the Schatten, Myers and Sofia (1996) forecast of 182+/-30. Cycle #23 extends from 1996 through approximately 2006 or 2007, with cycle #24 starting thereafter. We discuss the current forecast of solar cycle #24, (2006-2016), with a predicted smoothed F10.7 radio flux of 142+/-28 (1-sigma errors). This, we believe, represents a reprieve, in terms of reduced fuel costs, etc., for new satellites to be launched or old satellites (requiring reboosting) which have been placed in LEO. By monitoring the Sun s most deeply rooted magnetic fields; long-range solar activity can be predicted. Although a degree of uncertainty

Rest-Activity Cycles in Childhood and Adolescent Depression.

ERIC Educational Resources Information Center

Armitage, Roseanne; Hoffmann, Robert; Emslie, Graham; Rintelman, Jeanne; Moore, Jarrette; Lewis, Kelly

2004-01-01

Objective: To quantify circadian rhythms in rest-activity cycles in depressed children and adolescents. Method: Restactivity cycles were evaluated by actigraphy over five consecutive 24-hour periods in 100 children and adolescents, including 59 outpatients with major depressive disorder (MDD) and 41 healthy normal controls. Total activity, total…

Physical Limitations, Walkability, Perceived Environmental Facilitators and Physical Activity of Older Adults in Finland

PubMed Central

Portegijs, Erja; Keskinen, Kirsi E.; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2017-01-01

The aim was to study objectively assessed walkability of the environment and participant perceived environmental facilitators for outdoor mobility as predictors of physical activity in older adults with and without physical limitations. 75–90-year-old adults living independently in Central Finland were interviewed (n = 839) and reassessed for self-reported physical activity one or two years later (n = 787). Lower-extremity physical limitations were defined as Short Physical Performance Battery score ≤9. Number of perceived environmental facilitators was calculated from a 16-item checklist. Walkability index (land use mix, street connectivity, population density) of the home environment was calculated from geographic information and categorized into tertiles. Accelerometer-based step counts were registered for one week (n = 174). Better walkability was associated with higher numbers of perceived environmental facilitators (p < 0.001) and higher physical activity (self-reported p = 0.021, step count p = 0.010). Especially among those with physical limitations, reporting more environmental facilitators was associated with higher odds for reporting at least moderate physical activity (p < 0.001), but not step counts. Perceived environmental facilitators only predicted self-reported physical activity at follow-up. To conclude, high walkability of the living environment provides opportunities for physical activity in old age, but among those with physical limitations especially, awareness of environmental facilitators may be needed to promote physical activity. PMID:28327543

Physical Limitations, Walkability, Perceived Environmental Facilitators and Physical Activity of Older Adults in Finland.

PubMed

Portegijs, Erja; Keskinen, Kirsi E; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2017-03-22

The aim was to study objectively assessed walkability of the environment and participant perceived environmental facilitators for outdoor mobility as predictors of physical activity in older adults with and without physical limitations. 75-90-year-old adults living independently in Central Finland were interviewed ( n = 839) and reassessed for self-reported physical activity one or two years later ( n = 787). Lower-extremity physical limitations were defined as Short Physical Performance Battery score ≤9. Number of perceived environmental facilitators was calculated from a 16-item checklist. Walkability index (land use mix, street connectivity, population density) of the home environment was calculated from geographic information and categorized into tertiles. Accelerometer-based step counts were registered for one week ( n = 174). Better walkability was associated with higher numbers of perceived environmental facilitators ( p < 0.001) and higher physical activity (self-reported p = 0.021, step count p = 0.010). Especially among those with physical limitations, reporting more environmental facilitators was associated with higher odds for reporting at least moderate physical activity ( p < 0.001), but not step counts. Perceived environmental facilitators only predicted self-reported physical activity at follow-up. To conclude, high walkability of the living environment provides opportunities for physical activity in old age, but among those with physical limitations especially, awareness of environmental facilitators may be needed to promote physical activity.

Supporting Active Mobility and Green Jobs through the Promotion of Cycling

PubMed Central

Scotini, Rodrigo; Skinner, Ian; Racioppi, Francesca; Fusé, Virginia; Bertucci, Jonas de Oliveira; Tsutsumi, Rie

2017-01-01

This article is a summary of the main findings of the study “Riding towards the green economy: cycling and green jobs”, which was developed in the context of the Transport, Health and Environment pan-European Programme (THE PEP). It builds on previous work under THE PEP, which demonstrated the job creation potential of cycling and of green and healthy transport more generally. The report summarized in this article collected data on jobs associated with cycling directly from city authorities and analysed these to re-assess previous estimates of the job creation potential of cycling. It concluded that the number of cycling-related jobs in the pan-European Region could increase by 435,000 in selected major cities if they increased their cycling share to that of the Danish capital Copenhagen. The implications and potential role of municipal and sub-national authorities in facilitating cycling while supporting economic development are then discussed. These findings indicate that investment in policies that promote cycling could deliver not only important benefits for health, the environment and the quality of urban life, but could also contribute to a sizable creation of job opportunities. Authorities need to be proactive in promoting cycling in order to deliver these benefits. PMID:29257121

Supporting Active Mobility and Green Jobs through the Promotion of Cycling.

PubMed

Scotini, Rodrigo; Skinner, Ian; Racioppi, Francesca; Fusé, Virginia; Bertucci, Jonas de Oliveira; Tsutsumi, Rie

2017-12-19

This article is a summary of the main findings of the study "Riding towards the green economy: cycling and green jobs", which was developed in the context of the Transport, Health and Environment pan-European Programme (THE PEP). It builds on previous work under THE PEP, which demonstrated the job creation potential of cycling and of green and healthy transport more generally. The report summarized in this article collected data on jobs associated with cycling directly from city authorities and analysed these to re-assess previous estimates of the job creation potential of cycling. It concluded that the number of cycling-related jobs in the pan-European Region could increase by 435,000 in selected major cities if they increased their cycling share to that of the Danish capital Copenhagen. The implications and potential role of municipal and sub-national authorities in facilitating cycling while supporting economic development are then discussed. These findings indicate that investment in policies that promote cycling could deliver not only important benefits for health, the environment and the quality of urban life, but could also contribute to a sizable creation of job opportunities. Authorities need to be proactive in promoting cycling in order to deliver these benefits.

Perceived barriers and facilitators to physical activity for children with disability: a systematic review.

PubMed

Shields, Nora; Synnot, Anneliese Jane; Barr, Megan

2012-11-01

The aim of this systematic review was to investigate the perceived barriers and facilitators to physical activity among children with disability. 10 electronic databases were searched from the earliest time available to September 2010 to identify relevant articles. Articles were included if they examined the barriers or facilitators to physical activity for children with disability and were written in English. Articles were excluded if they included children with an acute, transient or chronic medical condition, examined sedentary leisure activities, or societal participation in general. Two reviewers independently assessed the search yields, extracted the data and assessed trial quality. Data were analysed descriptively. 14 articles met the inclusion criteria. Barriers included lack of knowledge and skills, the child's preferences, fear, parental behaviour, negative attitudes to disability, inadequate facilities, lack of transport, programmes and staff capacity, and cost. Facilitators included the child's desire to be active, practising skills, involvement of peers, family support, accessible facilities, proximity of location, better opportunities, skilled staff and information. Personal, social, environmental, and policy and programme-related barriers and facilitators influence the amount of activity children with disability undertake. The barriers to physical activity have been studied more comprehensively than the facilitators.

A qualitative theory guided analysis of stroke survivors' perceived barriers and facilitators to physical activity.

PubMed

Nicholson, Sarah L; Donaghy, Marie; Johnston, Marie; Sniehotta, Falko F; van Wijck, Frederike; Johnston, Derek; Greig, Carolyn; McMurdo, Marion E T; Mead, Gillian

2014-01-01

After stroke, physical activity and physical fitness levels are low, impacting on health, activity and participation. It is unclear how best to support stroke survivors to increase physical activity. Little is known about the barriers and facilitators to physical activity after stroke. Thus, our aim was to explore stroke survivors' perceived barriers and facilitators to physical activity. Semi-structured interviews with 13 ambulatory stroke survivors exploring perceived barriers and facilitators to physical activity post stroke were conducted in participants' homes, audio-recorded and transcribed verbatim. The Theoretical Domains Framework (TDF) informed content analysis of the interview transcripts. Data saturation was reached after interviews with 13 participants (median age of 76 years (inter-quartile range (IQR) = 69-83 years). The median time since stroke was 345 d (IQR = 316-366 d). The most commonly reported TDF domains were "beliefs about capabilities", "environmental context and resources" and "social influence". The most commonly reported perceived motivators were: social interaction, beliefs of benefits of exercise, high self-efficacy and the necessity of routine behaviours. The most commonly reported perceived barriers were: lack of professional support on discharge from hospital and follow-up, transport issues to structured classes/interventions, lack of control and negative affect. Stroke survivors perceive several different barriers and facilitators to physical activity. Stroke services need to address barriers to physical activity and to build on facilitators to promote physical activity after stroke. Physical activity post stroke can improve physical fitness and function, yet physical activity remains low among stroke survivors. Understanding stroke survivors' perceived barriers and facilitators to physical activity is essential to develop targeted interventions to increase physical activity. Beliefs about capabilities, environmental

POSSIBLE CHROMOSPHERIC ACTIVITY CYCLES IN AD LEO

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

Buccino, Andrea P.; Petrucci, Romina; Mauas, Pablo J. D.

2014-01-20

AD Leo (GJ 388) is an active dM3 flare star that has been extensively observed both in the quiescent and flaring states. Since this active star is near the fully convective boundary, studying its long-term chromospheric activity in detail could be an appreciable contribution to dynamo theory. Here, using the Lomb-Scargle periodogram, we analyze the Ca II K line-core fluxes derived from CASLEO spectra obtained between 2001 and 2013 and the V magnitude from the ASAS database between 2004 and 2010. From both of these totally independent time series, we obtain a possible activity cycle with a period of approximately seven yearsmore » and a less significant shorter cycle of approximately two years. A tentative interpretation is that a dynamo operating near the surface could be generating the longer cycle, while a second dynamo operating in the deep convection zone could be responsible for the shorter one. Based on the long duration of our observing program at CASLEO and the fact that we observe different spectral features simultaneously, we also analyze the relation between simultaneous measurements of the Na I index (R{sub D}{sup ′}), Hα, and Ca II K fluxes at different activity levels of AD Leo, including flares.« less

The Hydrologic Cycle Distributed Active Archive Center

NASA Technical Reports Server (NTRS)

Hardin, Danny M.; Goodman, H. Michael

1995-01-01

The Marshall Space Flight Center Distributed Active Archive Center in Huntsville, Alabama supports the acquisition, production, archival and dissemination of data relevant to the study of the global hydrologic cycle. This paper describes the Hydrologic Cycle DAAC, surveys its principle data holdings, addresses future growth, and gives information for accessing the data sets.

Activity Cycles in Stars

NASA Technical Reports Server (NTRS)

Hathaway, David H.

2009-01-01

Starspots and stellar activity can be detected in other stars using high precision photometric and spectrometric measurements. These observations have provided some surprises (starspots at the poles - sunspots are rarely seen poleward of 40 degrees) but more importantly they reveal behaviors that constrain our models of solar-stellar magnetic dynamos. The observations reveal variations in cycle characteristics that depend upon the stellar structure, convection zone dynamics, and rotation rate. In general, the more rapidly rotating stars are more active. However, for stars like the Sun, some are found to be inactive while nearly identical stars are found to be very active indicating that periods like the Sun's Maunder Minimum (an inactive period from 1645 to 1715) are characteristic of Sun-like stars.

The onset of the solar active cycle 22

NASA Technical Reports Server (NTRS)

Ahluwalia, H. S.

1989-01-01

There is a great deal of interest in being able to predict the main characteristics of a solar activity cycle (SAC). One would like to know, for instance, how large the amplitude (R sub m) of a cycle is likely to be, i.e., the annual mean of the sunspot numbers at the maximum of SAC. Also, how long a cycle is likely to last, i.e., its period. It would also be interesting to be able to predict the details, like how steep the ascending phase of a cycle is likely to be. Questions like these are of practical importance to NASA in planning the launch schedule for the low altitude, expensive spacecrafts like the Hubble Space Telescope, the Space Station, etc. Also, one has to choose a proper orbit, so that once launched the threat of an atmospheric drag on the spacecraft is properly taken into account. Cosmic ray data seem to indicate that solar activity cycle 22 will surpass SAC 21 in activity. The value of R sub m for SAC 22 may approach that of SAC 19. It would be interesting to see whether this prediction is borne out. Researchers are greatly encouraged to proceed with the development of a comprehensive prediction model which includes information provided by cosmic ray data.

Large Starspot Groups on HAT-P-11 in Activity Cycle 1

NASA Astrophysics Data System (ADS)

Morris, Brett M.; Hawley, Suzanne L.; Hebb, Leslie

2018-02-01

HAT-P-11 is a planet-hosting K4V star in the Kepler field, with an activity cycle that bear similarities to the Sun's. The chromospheric activity of HAT-P-11 indicates that a new activity cycle is beginning. We report ground-based observations with holographic diffuser photometry to measure the starspots of HAT-P-11 in its second observed magnetic activity cycle (Cycle 1). We find the area coverage of starspots within the transit chord for UTC 2017-10-30 is 14% --- which makes this transit the most spotted HAT-P-11 transit observed to date. We suggest that we are likely observing occultations of large spot groups appearing at the beginning of Cycle 1.

Cell cycle-coupled expansion of AR activity promotes cancer progression.

PubMed

McNair, C; Urbanucci, A; Comstock, C E S; Augello, M A; Goodwin, J F; Launchbury, R; Zhao, S G; Schiewer, M J; Ertel, A; Karnes, J; Davicioni, E; Wang, L; Wang, Q; Mills, I G; Feng, F Y; Li, W; Carroll, J S; Knudsen, K E

2017-03-23

The androgen receptor (AR) is required for prostate cancer (PCa) survival and progression, and ablation of AR activity is the first line of therapeutic intervention for disseminated disease. While initially effective, recurrent tumors ultimately arise for which there is no durable cure. Despite the dependence of PCa on AR activity throughout the course of disease, delineation of the AR-dependent transcriptional network that governs disease progression remains elusive, and the function of AR in mitotically active cells is not well understood. Analyzing AR activity as a function of cell cycle revealed an unexpected and highly expanded repertoire of AR-regulated gene networks in actively cycling cells. New AR functions segregated into two major clusters: those that are specific to cycling cells and retained throughout the mitotic cell cycle ('Cell Cycle Common'), versus those that were specifically enriched in a subset of cell cycle phases ('Phase Restricted'). Further analyses identified previously unrecognized AR functions in major pathways associated with clinical PCa progression. Illustrating the impact of these unmasked AR-driven pathways, dihydroceramide desaturase 1 was identified as an AR-regulated gene in mitotically active cells that promoted pro-metastatic phenotypes, and in advanced PCa proved to be highly associated with development of metastases, recurrence after therapeutic intervention and reduced overall survival. Taken together, these findings delineate AR function in mitotically active tumor cells, thus providing critical insight into the molecular basis by which AR promotes development of lethal PCa and nominate new avenues for therapeutic intervention.

Evidence for photometric activity cycles in 3203 Kepler stars

NASA Astrophysics Data System (ADS)

Reinhold, Timo; Cameron, Robert H.; Gizon, Laurent

2017-07-01

Context. In recent years it has been claimed that the length of stellar activity cycles is determined by the stellar rotation rate. It has been observed that the cycle period increases with rotation period along two distinct sequences, known as the active and inactive sequences. In this picture the Sun occupies a solitary position between the two sequences. Whether the Sun might undergo a transitional evolutionary stage is currently under debate. Aims: Our goal is to measure cyclic variations of the stellar light curve amplitude and the rotation period using four years of Kepler data. Periodic changes in the light curve amplitude or the stellar rotation period are associated with an underlying activity cycle. Methods: Using a recent sample of active stars we compute the rotation period and the variability amplitude for each individual Kepler quarter and search for periodic variations of both time series. To test for periodicity in each stellar time series we consider Lomb-Scargle periodograms and use a selection based on a false alarm probability (FAP). Results: We detect amplitude periodicities in 3203 stars between 0.5 < Pcyc < 6 yr covering rotation periods between 1 < Prot < 40 days. Given our sample size of 23 601 stars and our selection criteria that the FAP is less than 5%, this number is almost three times higher than that expected from pure noise. We do not detect periodicities in the rotation period beyond those expected from noise. Our measurements reveal that the cycle period shows a weak dependence on rotation rate, slightly increasing for longer rotation periods. We further show that the shape of the variability deviates from a pure sine curve, consistent with observations of the solar cycle. The cycle shape does not show a statistically significant dependence on effective temperature. Conclusions: We detect activity cycles in more than 13% of our final sample with a FAP of 5% (calculated by randomly shuffling the measured 90-day variability

Facilitating Active Engagement of the University Student in a Large-Group Setting Using Group Work Activities

ERIC Educational Resources Information Center

Kinsella, Gemma K.; Mahon, Catherine; Lillis, Seamus

2017-01-01

It is envisaged that small-group exercises as part of a large-group session would facilitate not only group work exercises (a valuable employability skill), but also peer learning. In this article, such a strategy to facilitate the active engagement of the student in a large-group setting was explored. The production of student-led resources was…

Physical Activity among Somali Men in Minnesota: Barriers, Facilitators and Recommendations

PubMed Central

Mohamed, Ahmed A.; Hassan, Abdullahi M.; Weis, Jennifer A.; Sia, Irene G.; Wieland, Mark L.

2014-01-01

Immigrants and refugees arrive to the US healthier than the general population, but this advantage declines with increasing duration of residence. One factor contributing to this decline is sub-optimal physical activity, but reasons for this are poorly understood. Persons from Somalia represent the largest African refugee population to the United States, yet little is known about perceptions of physical activity among Somali men. Somali members of a community-based participatory research partnership implemented three age-stratified focus groups and three semi-structured interviews among 20 Somali men in Rochester, MN. Team-based inductive analysis generated themes for barriers and facilitators to physical activity. Barriers to physical activity included less walking opportunities in the US, embarrassment about exercise clothing and lack of familiarity with exercise equipment/modalities, fear of harassment, competing priorities, facility costs, transportation, and winter weather. Facilitators to physical activity included high knowledge about how to be active, success stories from others in their community as inspiration, and community cohesion. Findings may be used to derive interventions aimed to promote physical activity among Somali men in the US. PMID:23697961

Periodic cycles of social outbursts of activity

NASA Astrophysics Data System (ADS)

Berestycki, H.; Rossi, L.; Rodríguez, N.

2018-01-01

We study the long-time behavior of a 2 × 2 continuous dynamical system with a time-periodic source term which is either of cooperative-type or activator-inhibitor type. This system was recently introduced in the literature [2] to model the dynamics of social outbursts and consists of an explicit field measuring the level of activity and an implicit field measuring the effective tension. The system can be used to represent a general type of phenomena in which one variable exhibits self-excitement once the other variable has reached a critical value. The time-periodic source term allows one to analyze the effect that periodic external shocks to the system play in the dynamics of the outburst of activity. For cooperative systems we prove that for small shocks the level of activity dies down whereas, as the intensity of the shocks increases, the level of activity converges to a positive periodic solution (excited cycle). We further show that in some cases there is multiplicity of excited cycles. We derive a subset of these results for the activator-inhibitor system.

Stellar activity cycles from long-term data by robotic telescopes

NASA Astrophysics Data System (ADS)

Oláh, K.

2014-03-01

All results about stellar activity cycles stem from decades-long systematic observations that were done by small telescopes. Without these equipments we would not know much, if anything, about stellar activity cycles, like those we see and observe easily on the nearest star, the Sun. In the early 80's of the last century systematic photometric monitoring of active stars began with automated photometric telescopes (APTs), some of which continue the observations to date. The Vienna-Potsdam APT now works for about two decades (Strassmeier et al. 1997), similarly to the 4-College Consortium APT (Dukes et al. 1995), while the Catania APT (Rodono et al. 2001) was closed down a few years ago. These small tools with the same setups for decades do not cost much and are relatively cheap to maintain. The longest continuous photometric datasets of a few objects from APTs span now over 30 years, which, together with earlier, manually-obtained data allow to study those activity cycles of stars which are in the order of 10 years or shorter: to be sure in the timescale of a cycle it should be observed repeatedly at least 2-3 times. The spectroscopic automated telescope STELLA (Strassmeier et al. 2004), built in the first decade of this century, measured already a few dozens of radial velocity curves for long-period binary stars and measured their activity levels (Strassmeier et al. 2012); these results can be gathered only by robotic telescopes. Only with STELLA it is possible to study the decades-long behavior of starspots on active giants with long rotational periods via Doppler Imaging. As the databases were growing it became clear that stars, just as the Sun, had multiple cycles. It was also found that stellar cycles showed systematic changes and that the cycle lengths correlated with the rotational periods of the stars. Extensive summaries of stellar activity cycles are found in Baliunas et al. (1995) using the Mt. Wilson Ca-index survey, and Oláh et al. (2009) based on

Radio Imaging Observations of Solar Activity Cycle and Its Anomaly

NASA Astrophysics Data System (ADS)

Shibasaki, K.

2011-12-01

The 24th solar activity cycle has started and relative sunspot numbers are increasing. However, their rate of increase is rather slow compared to previous cycles. Active region sizes are small, lifetime is short, and big (X-class) flares are rare so far. We study this anomalous situation using data from Nobeyama Radioheliograph (NoRH). Radio imaging observations have been done by NoRH since 1992. Nearly 20 years of daily radio images of the Sun at 17 GHz are used to synthesize a radio butterfly diagram. Due to stable operation of the instrument and a robust calibration method, uniform datasets are available covering the whole period of observation. The radio butterfly diagram shows bright features corresponding to active region belts and their migration toward low latitude as the solar cycle progresses. In the present solar activity cycle (24), increase of radio brightness is delayed and slow. There are also bright features around both poles (polar brightening). Their brightness show solar cycle dependence but peaks around solar minimum. Comparison between the last minimum and the previous one shows decrease of its brightness. This corresponds to weakening of polar magnetic field activity between them. In the northern pole, polar brightening is already weakened in 2011, which means it is close to solar maximum in the northern hemisphere. Southern pole does not show such feature yet. Slow rise of activity in active region belt, weakening of polar activity during the minimum, and large north-south asymmetry in polar activity imply that global solar activity and its synchronization are weakening.

RSPOs facilitated HSC activation and promoted hepatic fibrogenesis

PubMed Central

Yin, Xinguang; Yi, Huixing; Wang, Linlin; Wu, Wanxin; Wu, Xiaojun; Yu, Linghua

2016-01-01

Roof plate-specific spondin (RSPO) proteins are potent Wnt pathway agonists and involve in a broad range of developmental and physiological processes. This study investigated the activities and mechanisms of RSPOs in liver fibrogenesis, especially in hepatic stellate cell (HSC) activation. HSC activation was assessed by fibrosis biomarker (α-smooth muscle actin and Collagen-I), phenotypic change (accumulation of lipid droplets), and increased proliferation. Similarly, Wnt pathway activity was evaluated by the expression of nuclear β-catenin and T cell-specific transcription factors (TCF) activity. We found RSPOs were overexpressed in human fibrotic liver tissue and the expressions were correlated with liver fibrosis stages. In vitro studies showed RSPOs level increased during HSC activation, and stimuli with RSPOs enhanced Wnt pathway activity and promoted HSC activation subsequently. Furthermore, in vivo experiments demonstrated that the knockdown of RSPOs suppressed both Wnt pathway activity and HSC activation. Interestingly, the inhibitor of the Wnt signaling pathway Dickkopf1 impairs RSPOs effects on HSCs. Taken together, our results revealed that RSPOs facilitated HSC activation and promote liver fibrogenesis by enhancing the Wnt pathway. PMID:27572318

RSPOs facilitated HSC activation and promoted hepatic fibrogenesis.

PubMed

Yin, Xinguang; Yi, Huixing; Wang, Linlin; Wu, Wanxin; Wu, Xiaojun; Yu, Linghua

2016-09-27

Roof plate-specific spondin (RSPO) proteins are potent Wnt pathway agonists and involve in a broad range of developmental and physiological processes. This study investigated the activities and mechanisms of RSPOs in liver fibrogenesis, especially in hepatic stellate cell (HSC) activation. HSC activation was assessed by fibrosis biomarker (α-smooth muscle actin and Collagen-I), phenotypic change (accumulation of lipid droplets), and increased proliferation. Similarly, Wnt pathway activity was evaluated by the expression of nuclear β-catenin and T cell-specific transcription factors (TCF) activity. We found RSPOs were overexpressed in human fibrotic liver tissue and the expressions were correlated with liver fibrosis stages. In vitro studies showed RSPOs level increased during HSC activation, and stimuli with RSPOs enhanced Wnt pathway activity and promoted HSC activation subsequently. Furthermore, in vivo experiments demonstrated that the knockdown of RSPOs suppressed both Wnt pathway activity and HSC activation. Interestingly, the inhibitor of the Wnt signaling pathway Dickkopf1 impairs RSPOs effects on HSCs. Taken together, our results revealed that RSPOs facilitated HSC activation and promote liver fibrogenesis by enhancing the Wnt pathway.

Development of biology student worksheets to facilitate science process skills of student

NASA Astrophysics Data System (ADS)

Rahayu, Y. S.; Pratiwi, R.; Indana, S.

2018-01-01

This research aims to describe development of Biology student worksheets to facilitate science process skills of student, at the same time to facilitate thinking skills of students in senior high school are equipped with Assesment Sheets. The worksheets development refers to cycle which includes phase analysis (analysis), planning (planning), design (design), development (development), implementation (implementation), evaluation and revision (evaluation and revision). Phase evaluation and revision is an ongoing activity conducted in each phase of the development cycle. That is, after the evaluation of the results of these activities and make revisions at any phase, then continue to the next phase. Based on the test results for grade X, XI, and XII in St. Agnes Surabaya high school, obtained some important findings. The findings are as follows. (1) Developed biology student worksheets could be used to facilitate thinking ability of students in particular skills integrated process that includes components to formulate the problem, formulate hypotheses, determine the study variables, formulate an operational definition of variables, determine the steps in the research, planning data tables, organizing Data in the form of tables/charts, drawing conclusions, (2) Developed biology student worksheets could also facilitate the development of social interaction of students such as working together, listening/respect the opinions of others, assembling equipment and materials, discuss and share information and facilitate the upgrading of skills hands-on student activity. (3) Developed biology worksheets basically could be implemented with the guidance of the teacher step by step, especially for students who have never used a similar worksheet. Guidance at the beginning of this need, especially for worksheets that require special skills or understanding of specific concepts as a prerequisite, such as using a microscope, determine the heart rate, understand the mechanism of

Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes

NASA Technical Reports Server (NTRS)

Hathaway, David H.; Upton, Lisa

2013-01-01

We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow can modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields.

Evidence that displacement activities facilitate behavioural transitions in ring-tailed lemurs.

PubMed

Buckley, Victoria; Semple, Stuart

2012-07-01

Displacement activities are behavioural patterns defined by their apparent irrelevance to an animal's ongoing actions. Despite being identified in diverse taxa, their function remains poorly understood. One hypothesis posits that displacement activities facilitate transitions between different behaviours by mediating changes in animals' motivational state. Under this hypothesis, it is predicted that displacement activities will occur more frequently around changes in behaviour than at other times, and also that rates of displacement activities will be higher before than after such behavioural transitions. We tested these two predictions in wild ring-tailed lemurs (Lemur catta). During focal observations, animals' behavioural state was continuously recorded, as were all occurrences of self-scratching, a common displacement activity in this species. Self-scratching rates were found to be significantly elevated both before and after behavioural transitions. Furthermore, self-scratching rates were significantly higher before behavioural transitions occurred than after. These results, therefore, provide support for the hypothesis that displacement activities facilitate behavioural transitions in L. catta. Copyright © 2012 Elsevier B.V. All rights reserved.

Activity cycles in members of young loose stellar associations

NASA Astrophysics Data System (ADS)

Distefano, E.; Lanzafame, A. C.; Lanza, A. F.; Messina, S.; Spada, F.

2017-10-01

Context. Magnetic cycles analogous to the solar cycle have been detected in tens of solar-like stars by analyzing long-term time series of different magnetic activity indexes. The relationship between the cycle properties and global stellar parameters is not fully understood yet. One reason for this is the lack of long-term time series for stars covering a wide range of stellar parameters. Aims: We searched for activity cycles in a sample of 90 young solar-like stars with ages between 4 and 95 Myr with the aim to investigate the properties of activity cycles in this age range. Methods: We measured the length Pcyc of a given cycle by analyzing the long-term time series of three different activity indexes: the period of rotational modulation, the amplitude of the rotational modulation and the median magnitude in the V band. For each star, we also computed the global magnetic activity index ⟨ IQR ⟩ that is proportional to the amplitude of the rotational modulation and can be regarded as a proxy of the mean level of the surface magnetic activity. Results: We detected activity cycles in 67 stars. Secondary cycles were also detected in 32 stars of the sample. The lack of correlation between Pcyc and Prot and the position of our targets in the Pcyc/Prot-Ro-1 diagram suggest that these stars belong to the so-called transitional branch and that the dynamo acting in these stars is different from the solar dynamo and from that acting in the older Mt. Wilson stars. This statement is also supported by the analysis of the butterfly diagrams whose patterns are very different from those seen in the solar case. We computed the Spearman correlation coefficient rS between Pcyc, ⟨ IQR ⟩ and various stellar parameters. We found that Pcyc in our sample is uncorrelated with all the investigated parameters. The ⟨ IQR ⟩ index is positively correlated with the convective turnover timescale, the magnetic diffusivity timescale τdiff, and the dynamo number DN, whereas it is anti

Aerosol-delivered programmed cell death 4 enhanced apoptosis, controlled cell cycle and suppressed AP-1 activity in the lungs of AP-1 luciferase reporter mice.

PubMed

Hwang, S-K; Jin, H; Kwon, J T; Chang, S-H; Kim, T H; Cho, C-S; Lee, K H; Young, M R; Colburn, N H; Beck, G R; Yang, H-S; Cho, M-H

2007-09-01

The long-term survival of lung cancer patients treated with conventional therapies remains poor and therefore the need for novel approaches remains high. This has led to the re-emergence of aerosol delivery as a therapeutic intervention. In this study, glucosylated polyethylenimine (GPEI) was used as carrier to investigate programmed cell death 4 (PDCD4) and PDCD4 mutant (D418A), an eIF4A-binding mutant, on PDCD4-related signaling and activator protein-1 (AP-1) activity in the lungs of AP-1 luciferase reporter mice. After confirming the efficiency of GPEI as a carrier in lungs, the effects of aerosol-delivered PDCD4 were investigated in AP-1 luciferase reporter mice. Aerosol delivery of GPEI/PDCD4 through a nose-only inhalation facilitated the apoptosis of lungs whereas aerosol PDCD4 mutant did not. Also, such aerosol delivery regulated proteins relevant to cell-cycle control and suppressed AP-1 activity. Results obtained by western blot analysis, immunohistochemistry, luciferase assay and deoxynucleotidyl-transferase-mediated nick end labeling study suggest that combined actions such as facilitating apoptosis, controlling cell cycle and suppression of AP-1 activity by PDCD4 may provide useful tool for designing lung tumor prevention and treatment by which PDCD4 functions as a transformation suppressor in the future.

Forecast for solar cycle 23 activity: a progress report

NASA Astrophysics Data System (ADS)

Ahluwalia, H. S.

2001-08-01

At the 25th International Cosmic Ray Conference (ICRC) at Durban, South Africa, I announced the discovery of a three cycle quasi-periodicity in the ion chamber data string assembled by me, for the 1937 to 1994 period (Conf. Pap., v. 2, p. 109, 1997). It corresponded in time with a similar quasi-periodicity observed in the dataset for the planetary index Ap. At the 26th ICRC at Salt Lake City, UT, I reported on our analysis of the Ap data to forecast the amplitude of solar cycle 23 activity (Conf. Pap., v. 2, pl. 260, 1999). I predicted that cycle 23 will be moderate (a la cycle 17), notwithstanding the early exuberant forecasts of some solar astronomers that cycle 23, "may be one of the greatest cycles in recent times, if not the greatest." Sunspot number data up to April 2001 indicate that our forecast appears to be right on the mark. We review the solar, interplanetary and geophysical data and describe the important lessons learned from this experience. 1. Introduction Ohl (1971) was the first to realize that Sun may be sending us a subliminal message as to its intent for its activity (Sunspot Numbers, SSN) in the next cycle. He posited that the message was embedded in the geomagnetic activity (given by sum Kp). Schatten at al (1978) suggested that Ohl hypothesis could be understood on the basis of the model proposed by Babcock (1961) who suggested that the high latitude solar poloidal fields, near a minimum, emerge as the toroidal fields on opposite sides of the solar equator. This is known as the Solar Dynamo Model. One can speculate that the precursor poloidal solar field is entrained in the high speed solar wind streams (HSSWS) from the coronal holes which are observed at Earth's orbit during the descending phase of the previous cycle. The interaction

Medial Prefrontal Cortex Activation Facilitates Re-Extinction of Fear in Rats

ERIC Educational Resources Information Center

Chang, Chun-hui; Maren, Stephen

2011-01-01

It has been suggested that reduced infralimbic (IL) cortical activity contributes to impairments of fear extinction. We therefore explored whether pharmacological activation of the IL would facilitate extinction under conditions it normally fails (i.e., immediate extinction). Rats received auditory fear conditioning 1 h before extinction training.…

Accounting for the biogeochemical cycle of nitrogen in input-output life cycle assessment.

PubMed

Singh, Shweta; Bakshi, Bhavik R

2013-08-20

Nitrogen is indispensable for sustaining human activities through its role in the production of food, animal feed, and synthetic chemicals. This has encouraged significant anthropogenic mobilization of reactive nitrogen and its emissions into the environment resulting in severe disruption of the nitrogen cycle. This paper incorporates the biogeochemical cycle of nitrogen into the 2002 input-output model of the U.S. economy. Due to the complexity of this cycle, this work proposes a unique classification of nitrogen flows to facilitate understanding of the interaction between economic activities and various flows in the nitrogen cycle. The classification scheme distinguishes between the mobilization of inert nitrogen into its reactive form, use of nitrogen in various products, and nitrogen losses to the environment. The resulting inventory and model of the US economy can help quantify the direct and indirect impacts or dependence of economic sectors on the nitrogen cycle. This paper emphasizes the need for methods to manage the N cycle that focus not just on N losses, which has been the norm until now, but also include other N flows for a more comprehensive view and balanced decisions. Insight into the N profile of various sectors of the 2002 U.S. economy is presented, and the inventory can also be used for LCA or Hybrid LCA of various products. The resulting model is incorporated in the approach of Ecologically-Based LCA and available online.

Barriers and facilitators to being physically active on a rural U.S. Northern Plains American Indian reservation.

PubMed

Jahns, Lisa; McDonald, Leander R; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-11-21

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual's engagement in physical activity.

Solar-Cycle Variation of Subsurface-Flow Divergence: A Proxy of Magnetic Activity?

NASA Astrophysics Data System (ADS)

Komm, R.; Howe, R.; Hill, F.

2017-09-01

We study the solar-cycle variation of subsurface flows from the surface to a depth of 16 Mm. We have analyzed Global Oscillation Network Group (GONG) Dopplergrams with a ring-diagram analysis covering about 15 years and Helioseismic and Magnetic Imager (HMI) Dopplergrams covering more than 6 years. After subtracting the average rotation rate and meridional flow, we have calculated the divergence of the horizontal residual flows from the maximum of Solar Cycle 23 through the declining phase of Cycle 24. The subsurface flows are mainly divergent at quiet regions and convergent at locations of high magnetic activity. The relationship is essentially linear between divergence and magnetic activity at all activity levels at depths shallower than about 10 Mm. At greater depths, the relationship changes sign at locations of high activity; the flows are increasingly divergent at locations with a magnetic activity index (MAI) greater than about 24 G. The flows are more convergent by about a factor of two during the rising phase of Cycle 24 than during the declining phase of Cycle 23 at locations of medium and high activity (about 10 to 40 G MAI) from the surface to at least 10 Mm. The subsurface divergence pattern of Solar Cycle 24 first appears during the declining phase of Cycle 23 and is present during the extended minimum. It appears several years before the magnetic pattern of the new cycle is noticeable in synoptic maps. Using linear regression, we estimate the amount of magnetic activity that would be required to generate the precursor pattern and find that it should be almost twice the amount of activity that is observed.

Ribonuclease 5 facilitates corneal endothelial wound healing via activation of PI3-kinase/Akt pathway

PubMed Central

Kim, Kyoung Woo; Park, Soo Hyun; Lee, Soo Jin; Kim, Jae Chan

2016-01-01

To maintain corneal transparency, corneal endothelial cells (CECs) exert a pump function against aqueous inflow. However, human CECs are arrested in the G1-phase and non-proliferative in vivo. Thus, treatment of corneal endothelial decompensation is limited to corneal transplantation, and grafts are vulnerable to immune rejection. Here, we show that ribonuclease (RNase) 5 is more highly expressed in normal human CECs compared to decompensated tissues. Furthermore, RNase 5 up-regulated survival of CECs and accelerated corneal endothelial wound healing in an in vitro wound of human CECs and an in vivo cryo-damaged rabbit model. RNase 5 treatment rapidly induced accumulation of cytoplasmic RNase 5 into the nucleus, and activated PI3-kinase/Akt pathway in human CECs. Moreover, inhibition of nuclear translocation of RNase 5 using neomycin reversed RNase 5-induced Akt activation. As a potential strategy for proliferation enhancement, RNase 5 increased the population of 5-bromo-2′-deoxyuridine (BrdU)-incorporated proliferating CECs with concomitant PI3-kinase/Akt activation, especially in CECs deprived of contact-inhibition. Specifically, RNase 5 suppressed p27 and up-regulated cyclin D1, D3, and E by activating PI3-kinase/Akt in CECs to initiate cell cycle progression. Together, our data indicate that RNase 5 facilitates corneal endothelial wound healing, and identify RNase 5 as a novel target for therapeutic exploitation. PMID:27526633

Perceived barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities.

PubMed

Buffart, Laurien M; Westendorp, Tessa; van den Berg-Emons, Rita J; Stam, Henk J; Roebroeck, Marij E

2009-11-01

To explore the main barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities. Qualitative study using focus groups. Sixteen persons (12 men and 4 women) aged 22.4 (standard deviation 3.4) years, of whom 50% were wheelchair-dependent, participated in the study. Eight were diagnosed with myelomeningocele, 4 with cerebral palsy, 2 with acquired brain injury and 2 with rheumatoid arthritis. Three focus group sessions of 1.5 h were conducted using a semi-structured question route to assess perceived barriers to and facilitators of physical activity. Tape recordings were transcribed verbatim and content analysed. According to the Physical Activity for People with a Physical Disability model, barriers and facilitators were subdivided into personal factors and environmental factors. Participants reported several barriers related to attitude and motivation. In addition, lack of energy, existing injury or fear of developing injuries or complications, limited physical activity facilities, and lack of information and knowledge, appeared to be barriers to physical activity. Fun and social contacts were mentioned as facilitators of engaging in physical activity, as well as improved health and fitness. Young adults with childhood-onset physical disabilities perceived various personal and environmental factors as barriers to or facilitators of physical activity. These should be taken into account when developing interventions to promote physical activity in this population.

CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE

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

Jang, Minhwan; Choe, G. S.; Woods, T. N.

2016-12-10

It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this Letter, we investigate the high solar dynamic activity in the declining phase of the sunspot cycle by examining the evolution of polar and low-latitude coronal hole (CH) areas, splitting and merging events of CHs, and coronal mass ejections (CMEs) detected by SOHO /LASCO C3 in solar cycle 23. Although the total CH area is at its maximum near the sunspot minimum, in which polar CHs prevail, it shows a comparable secondmore » maximum in the declining phase of the cycle, in which low-latitude CHs are dominant. The events of CH splitting or merging, which are attributed to surface motions of magnetic fluxes, are also mostly populated in the declining phase of the cycle. The far-reaching C3 CMEs are also overpopulated in the declining phase of the cycle. From these results we suggest that solar dynamic activities due to the horizontal surface motions of magnetic fluxes extend far in the declining phase of the sunspot cycle.« less

Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes

NASA Technical Reports Server (NTRS)

Hathaway, David H.; Upton, Lisa

2013-01-01

We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow should also modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields. The observational evidence and the theoretical consequences (similar to those of Cameron and Schussler (2012)) will be described.

ERP evidence of distinct processes underlying semantic facilitation and interference in word production.

PubMed

Python, Grégoire; Fargier, Raphaël; Laganaro, Marina

2018-02-01

In everyday conversations, we take advantage of lexical-semantic contexts to facilitate speech production, but at the same time, we also have to reduce interference and inhibit semantic competitors. The blocked cyclic naming paradigm (BCNP) has been used to investigate such context effects. Typical results on production latencies showed semantic facilitation (or no effect) during the first presentation cycle, and interference emerging in subsequent cycles. Even if semantic contexts might be just as facilitative as interfering, previous BCNP studies focused on interference, which was interpreted as reflecting lemma selection and self-monitoring processes. Facilitation in the first cycle was rarely considered/analysed, although it potentially informs on word production to the same extent as interference. Here we contrasted the event-related potential (ERP) signatures of both semantic facilitation and interference in a BCNP. ERPs differed between homogeneous and heterogeneous blocks from about 365 msec post picture onset in the first cycle (facilitation) and in an earlier time-window (270 msec post picture onset) in the third cycle (interference). Three different analyses of the ERPs converge towards distinct processes underlying semantic facilitation and interference (post-lexical vs lexical respectively). The loci of semantic facilitation and interference are interpreted in the context of different theoretical frameworks of language production: the post-lexical locus of semantic facilitation involves interactive phonological-semantic processes and/or self-monitoring, whereas the lexical locus of semantic interference is in line with selection through increased lexical competition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Glutamine metabolism and cycling in Neurospora crassa.

PubMed Central

Mora, J

1990-01-01

Evidence for the existence of a glutamine cycle in Neurospora crassa is reviewed. Through this cycle glutamine is converted into glutamate by glutamate synthase and catabolized by the glutamine transaminase-omega-amidase pathway, the products of which (2-oxoglutarate and ammonium) are the substrates for glutamate dehydrogenase-NADPH, which synthesizes glutamate. In the final step ammonium is assimilated into glutamine by the action of a glutamine synthetase (GS), which is formed by two distinct polypeptides, one catalytically very active (GS beta), and the other (GS alpha) less active but endowed with the capacity to modulate the activity of GS alpha. Glutamate synthase uses the amide nitrogen of glutamine to synthesize glutamate; glutamate dehydrogenase uses ammonium, and both are required to maintain the level of glutamate. The energy expended in the synthesis of glutamine drives the cycle. The glutamine cycle is not futile, because it is necessary to drive an effective carbon flow to support growth; in addition, it facilitates the allocation of nitrogen or carbon according to cellular demands. The glutamine cycle which dissipates energy links catabolism and anabolism and, in doing so, buffers variations in the nutrient supply and drives energy generation and carbon flow for optimal cell function. PMID:2145504

Barriers and Facilitators to Being Physically Active on a Rural U.S. Northern Plains American Indian Reservation

PubMed Central

Jahns, Lisa; McDonald, Leander R.; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-01-01

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual’s engagement in physical activity. PMID:25421064

The Heliosphere Through the Solar Activity Cycle

NASA Technical Reports Server (NTRS)

Balogh, A.; Lanzerotti, L. J.; Suess, S. T.

2006-01-01

Understanding how the Sun changes though its 11-year sunspot cycle and how these changes affect the vast space around the Sun the heliosphere has been one of the principal objectives of space research since the advent of the space age. This book presents the evolution of the heliosphere through an entire solar activity cycle. The last solar cycle (cycle 23) has been the best observed from both the Earth and from a fleet of spacecraft. Of these, the joint ESA-NASA Ulysses probe has provided continuous observations of the state of the heliosphere since 1990 from a unique vantage point, that of a nearly polar orbit around the Sun. Ulysses results affect our understanding of the heliosphere from the interior of the Sun to the interstellar medium - beyond the outer boundary of the heliosphere. Written by scientists closely associated with the Ulysses mission, the book describes and explains the many different aspects of changes in the heliosphere in response to solar activity. In particular, the authors describe the rise in solar ESA and NASA have now unamiously agreed a third extension to operate the highly successful Ulysses spacecraft until March 2008 and, in 2007 and 2008, the European-built space probe will fly over the poles of the Sun for a third time. This will enable Ulysses to add an important chapter to its survey of the high-latitude heliosphere and this additional material would be included in a 2nd edition of this book.

OECD/NEA Ongoing activities related to the nuclear fuel cycle

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

Cornet, S.M.; McCarthy, K.; Chauvin, N.

2013-07-01

As part of its role in encouraging international collaboration, the OECD Nuclear Energy Agency is coordinating a series of projects related to the Nuclear Fuel Cycle. The Nuclear Science Committee (NSC) Working Party on Scientific Issues of the Nuclear Fuel Cycle (WPFC) comprises five different expert groups covering all aspects of the fuel cycle from front to back-end. Activities related to fuels, materials, physics, separation chemistry, and fuel cycles scenarios are being undertaken. By publishing state-of-the-art reports and organizing workshops, the groups are able to disseminate recent research advancements to the international community. Current activities mainly focus on advanced nuclearmore » systems, and experts are working on analyzing results and establishing challenges associated to the adoption of new materials and fuels. By comparing different codes, the Expert Group on Advanced Fuel Cycle Scenarios is aiming at gaining further understanding of the scientific issues and specific national needs associated with the implementation of advanced fuel cycles. At the back end of the fuel cycle, separation technologies (aqueous and pyrochemical processing) are being assessed. Current and future activities comprise studies on minor actinides separation and post Fukushima studies. Regular workshops are also organized to discuss recent developments on Partitioning and Transmutation. In addition, the Nuclear Development Committee (NDC) focuses on the analysis of the economics of nuclear power across the fuel cycle in the context of changes of electricity markets, social acceptance and technological advances and assesses the availability of the nuclear fuel and infrastructure required for the deployment of existing and future nuclear power. The Expert Group on the Economics of the Back End of the Nuclear Fuel Cycle (EBENFC), in particular, is looking at assessing economic and financial issues related to the long term management of spent nuclear fuel. (authors)« less

Torque, power and muscle activation of eccentric and concentric isokinetic cycling.

PubMed

Green, David J; Thomas, Kevin; Ross, Emma Z; Green, Steven C; Pringle, Jamie S M; Howatson, Glyn

2018-06-01

This study aimed to establish the effect of cycling mode and cadence on torque, external power output, and lower limb muscle activation during maximal, recumbent, isokinetic cycling. After familiarisation, twelve healthy males completed 6 × 10 s of maximal eccentric (ECC) and concentric (CON) cycling at 20, 40, 60, 80, 100, and 120 rpm with five minutes recovery. Vastus lateralis, medial gastrocnemius, rectus femoris, and biceps femoris surface electromyography was recorded throughout. As cadence increased, peak torque linearly decreased during ECC (350-248 N·m) and CON (239-117 N·m) and peak power increased in a parabolic manner. Crank angle at peak torque increased with cadence in CON (+13°) and decreased in ECC (-9.0°). At all cadences, peak torque (mean +129 N·m, range 111-143 N·m), and power (mean +871 W, range 181-1406 W), were greater during ECC compared to CON. For all recorded muscles the crank angle at peak muscle activation was greater during ECC compared to CON. This difference increased with cadence in all muscles except the vastus lateralis. Additionally, peak vastus laterallis and biceps femoris activation was greater during CON compared to ECC. Eccentric cycling offers a greater mechanical stimulus compared to concentric cycling but the effect of cadence is similar between modalities. Markers of technique (muscle activation, crank angle at peak activation and torque) were different between eccentric and concentric cycling and respond differently to changes in cadence. Such data should be considered when comparing between, and selecting cadences for, recumbent, isokinetic, eccentric and concentric cycling. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

The Effect of Cycling Intensity on Cycling Economy During Seated and Standing Cycling.

PubMed

Arkesteijn, Marco; Jobson, Simon; Hopker, James; Passfield, Louis

2016-10-01

Previous research has shown that cycling in a standing position reduces cycling economy compared with seated cycling. It is unknown whether the cycling intensity moderates the reduction in cycling economy while standing. The aim was to determine whether the negative effect of standing on cycling economy would be decreased at a higher intensity. Ten cyclists cycled in 8 different conditions. Each condition was either at an intensity of 50% or 70% of maximal aerobic power at a gradient of 4% or 8% and in the seated or standing cycling position. Cycling economy and muscle activation level of 8 leg muscles were recorded. There was an interaction between cycling intensity and position for cycling economy (P = .03), the overall activation of the leg muscles (P = .02), and the activation of the lower leg muscles (P = .05). The interaction showed decreased cycling economy when standing compared with seated cycling, but the difference was reduced at higher intensity. The overall activation of the leg muscles and the lower leg muscles, respectively, increased and decreased, but the differences between standing and seated cycling were reduced at higher intensity. Cycling economy was lower during standing cycling than seated cycling, but the difference in economy diminishes when cycling intensity increases. Activation of the lower leg muscles did not explain the lower cycling economy while standing. The increased overall activation, therefore, suggests that increased activation of the upper leg muscles explains part of the lower cycling economy while standing.

The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

ERIC Educational Resources Information Center

Scherer, Yvette D.

2014-01-01

In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

Constraints and Facilitators for Physical Activity in Family Day Care

ERIC Educational Resources Information Center

O'Connor, Justen P.; Temple, Viviene A.

2005-01-01

Movement-seeking behaviours should be fostered in young children to maximise their potential to adopt and maintain a physically active lifestyle. This study examined the constraints and facilitators to meaningful movement for children in family day care. The views of key stakeholders (caregivers, parents, and coordination unit staff) were examined…

A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

PubMed

Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

2016-04-04

How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation. Copyright © 2016 Elsevier Inc. All rights reserved.

Relationship between skin temperature and muscle activation during incremental cycle exercise.

PubMed

Priego Quesada, Jose I; Carpes, Felipe P; Bini, Rodrigo R; Salvador Palmer, Rosario; Pérez-Soriano, Pedro; Cibrián Ortiz de Anda, Rosa M

2015-02-01

While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four body regions of interest corresponding to the muscles where neuromuscular activations were monitored. Frequency band analysis was conducted to assess spectral properties of EMG signals in order to infer on priority in recruitment of motor units. Significant inverse relationship between changes in skin temperature and changes in overall neuromuscular activation for vastus lateralis was observed (r<-0.5 and p<0.04). Significant positive relationship was observed between skin temperature and low frequency components of neuromuscular activation from vastus lateralis (r>0.7 and p<0.01). Participants with larger overall activation and reduced low frequency component for vastus lateralis activation presented a better adaptive response of their thermoregulatory system by showing fewer changes in skin temperature after incremental cycling test. Copyright © 2014 Elsevier Ltd. All rights reserved.

Colloid-facilitated mobilization of metals by freeze-thaw cycles.

PubMed

Mohanty, Sanjay K; Saiers, James E; Ryan, Joseph N

2014-01-21

The potential of freeze-thaw cycles to release colloids and colloid-associated contaminants into water is unknown. We examined the effect of freeze-thaw cycles on the mobilization of cesium and strontium in association with colloids in intact cores of a fractured soil, where preferential flow paths are prevalent. Two intact cores were contaminated with cesium and strontium. To mobilize colloids and metal cations sequestered in the soil cores, each core was subjected to 10 intermittent wetting events separated by 66 h pauses. During the first five pauses, the cores were dried at room temperature, and during last five pauses, the cores were subjected to 42 h of freezing followed by 24 h of thawing. In comparison to drying, freeze-thaw cycles created additional preferential flow paths through which colloids, cesium, and strontium were mobilized. The wetting events following freeze-thaw intervals mobilized about twice as many colloids as wetting events following drying at room temperature. Successive wetting events following 66 h of drying mobilized similar amounts of colloids; in contrast, successive wetting events after 66 h of freeze-thaw intervals mobilized greater amounts of colloids than the previous one. Drying and freeze-thaw treatments, respectively, increased and decreased the dissolved cesium and strontium, but both treatments increased the colloidal cesium and strontium. Overall, the freeze-thaw cycles increased the mobilization of metal contaminants primarily in association with colloids through preferential flow paths. These findings suggest that the mobilization of colloid and colloid-associated contaminants could increase when temperature variations occur around the freezing point of water. Thus, climate extremes have the potential to mobilize contaminants that have been sequestered in the vadose zone for decades.

Physically active academic lessons: acceptance, barriers and facilitators for implementation.

PubMed

Dyrstad, Sindre M; Kvalø, Silje E; Alstveit, Marianne; Skage, Ingrid

2018-03-06

To improve health and academic learning in schoolchildren, the Active School programme in Stavanger, Norway has introduced physically active academic lessons. This is a teaching method combining physical activity with academic content. The purpose of this paper was to evaluate the response to the physically active lessons and identify facilitators and barriers for implementation of such an intervention. Five school leaders (principals or vice-principals), 13 teachers and 30 children from the five intervention schools were interviewed about their experiences with the 10-month intervention, which consisted of weekly minimum 2 × 45 minutes of physically active academic lessons, and the factors affecting its implementation. All interviews were transcribed and analysed using the qualitative data analysis program NVivo 10 (QSR international, London, UK). In addition, weekly teacher's intervention delivery logs were collected and analysed. On average, the physically active academic lessons in 18 of the 34 weeks (53%) were reported in the teacher logs. The number of delivered physically active academic lessons covered 73% of the schools' planned activity. Physically active lessons were well received among school leaders, teachers and children. The main facilitators for implementation of the physically active lessons were active leadership and teacher support, high self-efficacy regarding mastering the intervention, ease of organizing physically active lessons, inclusion of physically active lessons into the lesson curricula, and children's positive reception of the intervention. The main barriers were unclear expectations, lack of knowledge and time to plan the physiclly active lessons, and the length of the physically active lessons (15-20 min lessons were preferred over the 45 min lessons). Physically active academic lessons were considered an appropriate pedagogical method for creating positive variation, and were highly appreciated among both teachers and

The activity of salivary aldehyde dehydrogenase during the menstrual cycle and pregnancy.

PubMed

Giebułtowicz, Joanna; Wroczyński, Piotr; Kosiński, Przemysław; Pietrzak, Bronisława

2013-03-01

The aim of the present study was to describe the changes in the activity of ALDH3A1 in saliva in relation to the menstrual cycle and pregnancy. We also measured major salivary antioxidants, salivary peroxidase (SPO) activity and uric acid (UA) concentration. Fasting saliva samples were collected from 63 women with uncomplicated pregnancies and from 39 healthy women of reproductive age, but not pregnant. Saliva samples were also collected from 10 healthy women with regular menstrual cycles in the early follicular, the mid-cycle and the mid-luteal phase during one menstrual cycle. SPO and ALDH3A1 activity was determined fluorimetrically, whereas UA concentration photometrically. The ALDH3A1 did not vary significantly among phases of menstrual cycle. However, the enzyme activity decreased with the length of pregnancy and in the third trimester is significantly lower than that in the saliva of non-pregnant women. Lower concentration of UA and in the third trimester the activity of ALDH3A1 in saliva of pregnant women could be a risk factor of, e.g. oral pathologies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Activities of Tricarboxylic Acid Cycle Enzymes, Glyoxylate Cycle Enzymes, and Fructose Diphosphatase in Bakers' Yeast During Adaptation to Acetate Oxidation

PubMed Central

Gosling, J. P.; Duggan, P. F.

1971-01-01

Bakers' yeast oxidizes acetate at a high rate only after an adaptation period during which the capacity of the glyoxylate cycle is found to increase. There was apparently no necessity for the activity of acetyl-coenzyme A synthetase, the capacity of the tricarboxylic acid cycle, or the concentrations of the cytochromes to increase for this adaptation to occur. Elevation of fructose 1,6 diphosphatase occurred only when acetate oxidation was nearly maximal. Cycloheximide almost completely inhibited adaptation as well as increases in the activities of isocitrate lyase and aconitate hydratase, the only enzymes assayed. p-Fluorophenylalanine was partially effective and chloramphenicol did not inhibit at all. The presence of ammonium, which considerably delayed adaptation of the yeast to acetate oxidation, inhibited the increases in the activities of the glyoxylate cycle enzymes to different degrees, demonstrating noncoordinate control of these enzymes. Under the various conditions, the only enzyme activity increase consistently related to the rising oxygen uptake rate was that of isocitrate lyase which apparently limited the activity of the cycle. PMID:5557595

Perceived barriers and facilitators to physical activity in men with prostate cancer: possible influence of androgen deprivation therapy.

PubMed

Keogh, J W L; Patel, A; MacLeod, R D; Masters, J

2014-03-01

While physical activity is beneficial for men with prostate cancer, too few perform sufficient activity for such benefit. This study examined perceptions of men with prostate cancer of their barriers and facilitators to physical activity, and how androgen deprivation therapy (ADT) may influence these perceptions. Two focus groups were conducted, involving six ADT and eight non-ADT patients respectively. Data were transcribed verbatim and themes developed using a general inductive thematic approach. Facilitators to physical activity common to both groups of cancer survivors included clinician and spousal involvement, with pre-existing co-morbidities and increased age cited as barriers by both groups. The ADT subgroup cited personal involvement as a facilitator to physical activity, with fatigue, reduced motivation and a relative lack of specific advice from their clinician as additional barriers. The non-ADT subgroup had no additional facilitators to physical activity but cited time constraints as a barrier. These results highlight the important role that cancer clinicians and spouses play in promoting physical activity for men with prostate cancer and how ADT may influence their other facilitators and barriers. As physical activity is beneficial for prostate cancer survivors, especially those on ADT, cancer clinicians should regularly discuss physical activity with their patients. © 2013 John Wiley & Sons Ltd.

A solar cycle timing predictor - The latitude of active regions

NASA Technical Reports Server (NTRS)

Schatten, Kenneth H.

1990-01-01

A 'Spoerer butterfly' method is used to examine solar cycle 22. It is shown from the latitude of active regions that the cycle can now be expected to peak near November 1989 + or - 8 months, basically near the latter half of 1989.

MAGNETIC ACTIVITY CYCLES IN THE EXOPLANET HOST STAR {epsilon} ERIDANI

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

Metcalfe, T. S.; Mathur, S.; Buccino, A. P.

2013-02-01

The active K2 dwarf {epsilon} Eri has been extensively characterized both as a young solar analog and more recently as an exoplanet host star. As one of the nearest and brightest stars in the sky, it provides an unparalleled opportunity to constrain stellar dynamo theory beyond the Sun. We confirm and document the 3-year magnetic activity cycle in {epsilon} Eri originally reported by Hatzes and coworkers, and we examine the archival data from previous observations spanning 45 years. The data show coexisting 3-year and 13-year periods leading into a broad activity minimum that resembles a Maunder minimum-like state, followed bymore » the resurgence of a coherent 3-year cycle. The nearly continuous activity record suggests the simultaneous operation of two stellar dynamos with cycle periods of 2.95 {+-} 0.03 years and 12.7 {+-} 0.3 years, which, by analogy with the solar case, suggests a revised identification of the dynamo mechanisms that are responsible for the so-called 'active' and 'inactive' sequences as proposed by Boehm-Vitense. Finally, based on the observed properties of {epsilon} Eri, we argue that the rotational history of the Sun is what makes it an outlier in the context of magnetic cycles observed in other stars (as also suggested by its Li depletion), and that a Jovian-mass companion cannot be the universal explanation for the solar peculiarities.« less

Understanding barriers and facilitators to healthy eating and physical activity from patients either before and after knee arthroplasty.

PubMed

Pellegrini, Christine A; Ledford, Gwendolyn; Chang, Rowland W; Cameron, Kenzie A

2017-05-05

We sought to identify patient-reported barriers and facilitators to healthy eating and physical activity among patients before or after knee arthroplasty. Twenty patients with knee osteoarthritis aged 40-79 years who had knee arthroplasty surgery scheduled or completed within 3 months were interviewed. Interview topics included perceived barriers and facilitators to healthy eating and activity before or after surgery. Interviews were coded and analyzed using constant comparative analysis. Interviews were completed with 11 pre-operative (67.1 ± 7.6 years, 45.5% female, BMI 31.2 ± 6.3) and nine post-operative patients (61.7 ± 11.7 years, 44.4% female, BMI 30.2 ± 4.7 kg/m 2 ). The most commonly identified personal barriers to healthy eating identified were desire for high-fat/high-calorie foods, managing overconsumption and mood. Factors related to planning, portion control and motivation to improve health were identified as healthy eating facilitators. Identified personal barriers for activity included pain, physical limitations and lack of motivation, whereas facilitators included having motivation to improve knee symptoms/outcomes, personal commitment to activity and monitoring activity levels. Identifying specific eating and activity barriers and facilitators, such as mood and motivation to improve outcomes, provides critical insight from the patient perspective, which will aid in developing weight management programs during rehabilitation for knee arthroplasty patients. Implications for rehabilitation This study provides insight into the identified barriers and facilitators to healthy eating and physical activity in knee arthroplasty patients, both before and after surgery. Intrapersonal barriers that may hinder engagement in physical activity and rehabilitation include pain, physical limitations and lack of motivation; factors that may help to improve activity and the rehabilitation process include being motivated to improve knee outcomes

Identifying Facilitators and Barriers to Physical Activity for Adults with Down Syndrome

ERIC Educational Resources Information Center

Mahy, J.; Shields, N.; Taylor, N. F.; Dodd, K. J.

2010-01-01

Background: Adults with Down syndrome are typically sedentary, and many do not participate in the recommended levels of physical activity per week. The aim of this study was to identify the facilitators and barriers to physical activity for this group. Method: Semi-structured interviews were conducted to elicit the views of adults with Down…

Activity-Dependent Calpain Activation Plays a Critical Role in Synaptic Facilitation and Post-Tetanic Potentiation

ERIC Educational Resources Information Center

Khoutorsky, Arkady; Spira, Micha E.

2009-01-01

Synaptic facilitation and post-tetanic potentiation (PTP) are believed to necessitate active regeneration of the release machinery and supply of synaptic vesicles to a ready-releasable site. The prevailing hypothesis assumes that synapsins play pivotal roles in these processes. Using a cholinergic synapse formed between cultured "Aplysia" neurons…

Barriers to and Facilitators of Healthful Eating and Physical Activity in Low-Income Schools

ERIC Educational Resources Information Center

Hammerschmidt, Patricia; Tackett, Wendy; Golzynski, Matthew; Golzynski, Diane

2011-01-01

Objective: To identify barriers to and facilitators of healthful eating and physical activity in low-income schools as perceived by school-affiliated staff. Methods: Perceptions of barriers and facilitators were measured in low-income schools through two online surveys (Kindergarten-8th grade and high school). Sixty-nine (Kindergarten-8th grade)…

Human Enterovirus 68 Interferes with the Host Cell Cycle to Facilitate Viral Production

PubMed Central

Wang, Zeng-yan; Zhong, Ting; Wang, Yue; Song, Feng-mei; Yu, Xiao-feng; Xing, Li-ping; Zhang, Wen-yan; Yu, Jing-hua; Hua, Shu-cheng; Yu, Xiao-fang

2017-01-01

Enterovirus D68 (EV-D68) is an emerging pathogen that recently caused a large outbreak of severe respiratory disease in the United States and other countries. Little is known about the relationship between EV-D68 virus and host cells. In this study, we assessed the effect of the host cell cycle on EV-D68 viral production, as well as the ability of EV-D68 to manipulate host cell cycle progression. The results suggest that synchronization in G0/G1 phase, but not S phase, promotes viral production, while synchronization in G2/M inhibits viral production. Both an early EV-D68 isolate and currently circulating strains of EV-D68 can manipulate the host cell cycle to arrest cells in the G0/G1 phase, thus providing favorable conditions for virus production. Cell cycle regulation by EV-D68 was associated with corresponding effects on the expression of cyclins and CDKs, which were observed at the level of the protein and/or mRNA. Furthermore, the viral non-structural protein 3D of EV-D68 prevents progression from G0/G1 to S. Interestingly, another member of the Picornaviridae family, EV-A71, differs from EV-D68 in that G0/G1 synchronization inhibits, rather than promotes, EV-A71 viral replication. However, these viruses are similar in that G2/M synchronization inhibits the production and activity of both viruses, which is suggestive of a common therapeutic target for both types of enterovirus. These results further clarify the pathogenic mechanisms of enteroviruses and provide a potential strategy for the treatment and prevention of EV-D68-related disease. PMID:28229049

Transcription and the IELTS Speaking Test: Facilitating Development

ERIC Educational Resources Information Center

Stones, Thomas P.

2013-01-01

This article describes a transcription task cycle that was designed to facilitate the development of skills for the IELTS (International English Language Testing System) speaking test at a language school in Japan. The cycle involved practice test, transcription, student correction, teacher correction, and retrial of the original test and…

Perceptions of barriers and facilitators in physical activity participation among women in Thiruvananthapuram City, India.

PubMed

Mathews, Elezebeth; Lakshmi, J K; Ravindran, T K Sundari; Pratt, Michael; Thankappan, K R

2016-12-01

Despite the known benefits of physical activity, very few people, especially women, are found to engage in regular physical activity. This study explored the perceptions, barriers and facilitators related to physical activity among women in Thiruvananthapuram City, India. Four focus group discussions were conducted among individuals between 25 and 60 years of age, in a few areas of Thiruvananthapuram City Corporation limits in Kerala, preparatory to the design of a physical activity intervention trial. An open-ended approach was used and emergent findings were analyzed and interpreted. Women associated physical activity mostly with household activities. The majority of the women considered their activity level adequate, although they engaged in what the researchers concluded were quite low levels of activity. Commonly reported barriers were lack of time, motivation, and interest; stray dogs; narrow roads; and not being used to the culture of walking. Facilitators of activity were seeing others walking, walking in pairs, and pleasant walking routes. Walking was reported as the most feasible physical activity by women. Physical activity promotion strategies among women should address the prevailing cultural norms in the community, and involve social norming and overcoming cultural barriers. They should also target the modifiable determinants of physical activity, such as improving self-efficacy, improving knowledge on the adequacy of physical activity and its recommendations, facilitating goal-setting, and enhancing social support through peer support and group-based activities. © The Author(s) 2015.

Facilitators and barriers to physical activity as perceived by older adults with intellectual disability.

PubMed

van Schijndel-Speet, Marieke; Evenhuis, Heleen M; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A

2014-06-01

Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID for specific physical activities, and to gain insight into facilitators and barriers to engaging into PA. Fourteen in-depth interviews and four focus groups were undertaken, with a total of 40 older adults with mild and moderate ID included in the analysis. NVivo software was used for analysing the transcribed verbatim interviews. In total, 30 codes for facilitators and barriers were identified. Themes concerning facilitators to PA were enjoyment, support from others, social contact and friendship, reward, familiarity, and routine of activities. Themes concerning barriers to PA were health and physiological factors, lack of self-confidence, lack of skills, lack of support, transportation problems, costs, and lack of appropriate PA options and materials. The results of the present study suggest that older adults with ID may benefit from specific PA programs, adapted to their individual needs and limitations. Results can be used for developing feasible health promotion programs for older adults with ID.

Dose–response associations between cycling activity and risk of hypertension in regular cyclists: The UK Cycling for Health Study

PubMed Central

Hollingworth, M; Harper, A; Hamer, M

2015-01-01

Most population studies on physical activity and health have involved largely inactive men and women, thus making it difficult to infer if health benefits occur at exercise levels above the current minimum guidelines. The aim was to examine associations between cycling volume and classical cardiovascular risk markers, including hypertension and hypercholesterolemia, in a population sample of habitual cyclists. A nationwide sample comprising 6949 men and women (aged 47.6 years on average) completed questions about their cycling levels, demographics and health. Nearly the entire sample (96.3%) achieved the current minimum physical activity recommendation through cycling alone. There was a dose–response association between cycling volume and risk of diagnosed hypertension (P-trend =0.001), with odds ratios of 0.98 (95% confidence interval (CI), 0.80–1.21), 0.86 (0.70, 1.06), 0.67 (95% CI, 0.53–0.83) across categories of 23–40, 40–61 and >61 metabolic equivalent hours/week (MET-h/week) compared with <23 MET-h/week. These associations persisted in models adjusted for age, sex, smoking, alcohol, body mass index (BMI) and other moderatevigorous physical activities. We also observed inverse associations between cycling volume and other risk factors including BMI and hypercholesterolemia. In summary, results from a population sample of cyclists suggest that additional cardiovascular health benefits can be achieved beyond the current minimum physical activity recommendation. PMID:25273856

Barriers and facilitators to the implementation of physical activity policies in schools: A systematic review.

PubMed

Nathan, Nicole; Elton, Ben; Babic, Mark; McCarthy, Nicole; Sutherland, Rachel; Presseau, Justin; Seward, Kirsty; Hodder, Rebecca; Booth, Debbie; Yoong, Sze Lin; Wolfenden, Luke

2018-02-01

Research consistently indicates that schools fail to implement mandatory physical activity policies. This review aimed to describe factors (barriers and facilitators) that may influence the implementation of school physical activity policies which specify the time or intensity that physical activity should be implemented and to map these factors to a theoretical framework. A systematic search was undertaken in six databases for quantitative or qualitative studies published between 1995-March 2016 that examined teachers', principals' or school administrators' reported barriers and/or facilitators to implementing mandated school physical activity policies. Two independent reviewers screened texts, extracted and coded data from identified articles using the Theoretical Domains Framework (TDF). Of the 10,346 articles identified, 17 studies met the inclusion criteria (8 quantitative, 9 qualitative). Barriers and facilitators identified in qualitative studies covered 9 and 10 TDF domains respectively. Barriers and facilitators reported in quantitative studies covered 8 TDF domains each. The most common domains identified were: 'environmental context and resources' (e.g., availability of equipment, time or staff), 'goals' (e.g., the perceived priority of the policy in the school), 'social influences' (e.g., support from school boards), and 'skills' (e.g., teachers' ability to implement the policy). Implementation support strategies that target these factors may represent promising means to improve implementation of physical activity policies and increase physical activity among school-aged children. Future studies assessing factors that influence school implementation of physical activity policies would benefit from using a comprehensive framework to help identify if any domains have been overlooked in the current literature. This review was prospectively registered with PROSPERO (CRD42016051649) on the 8th December 2016. Copyright © 2017 Elsevier Inc. All rights

Disentangling Facilitation Along the Life Cycle: Impacts of Plant-Plant Interactions at Vegetative and Reproductive Stages in a Mediterranean Forb.

PubMed

García-Cervigón, Ana I; Iriondo, José M; Linares, Juan C; Olano, José M

2016-01-01

Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant-plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels, and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant-plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower, and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant-plant interactions.

Sudomotor and vasomotor activity during the menstrual cycle with global heating.

PubMed

Petrofsky, Jerrold; Lee, Haneul; Khowailed, Iman Akef

2017-07-01

Many studies have reported that there are changes in sympathetic activity throughout the menstrual cycle as there are oestrogen receptor in the hypothalamus and all other parts of the sympathetic nervous system. The purpose of this study was to see whether there were variations in sympathetic activity, skin vasomotor and sweat gland sudomotor rhythms during the menstrual cycle. Eight young female subjects with a regular menstrual cycle participated in the study. Subjects were tested once during the follicular phase and once during the luteal phase. Skin blood flow and sweat rate were significantly higher in the luteal phase compared with the follicular phase (p < .05), but the frequency and magnitude of sudomotor and vasomotor rhythms were significantly greater in the follicular phase (p < .05). In contrast, spectral data showed less sympathetic activity in the luteal phase. A significant finding here is that the sudomotor rhythm of sweat glands is altered by the menstrual cycle. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Facilitated extracellular electron transfer of Shewanella loihica PV-4 by antimony-doped tin oxide nanoparticles as active microelectrodes.

PubMed

Zhang, Xiaojian; Liu, Huan; Wang, Jinrong; Ren, Guangyuan; Xie, Beizhen; Liu, Hong; Zhu, Ying; Jiang, Lei

2015-11-28

Dissimilatory metal reducing bacteria are capable of extracellular electron transfer (EET) to insoluble metal oxides as external electron acceptors for their anaerobic respiration, which is recognized as an important energy-conversion process in natural and engineered environments, such as in mineral cycling, bioremediation, and microbial fuel/electrolysis cells. However, the low EET efficiency remains one of the major bottlenecks for its practical application. We report firstly that the microbial current generated by Shewanella loihica PV-4 (S. loihica PV-4) could be greatly improved that is up to ca. 115 fold, by adding antimony-doped tin oxide (ATO) nanoparticles in the electrochemical reactor. The results demonstrate that the biocompatible, electrically conductive ATO nanoparticles acted as active microelectrodes could facilitate the formation of a cells/ATO composite biofilm and the reduction of the outer membrane c-type cytochromes (OM c-Cyts) that are beneficial for the electron transfer from cells to electrode. Meanwhile, a synergistic effect between the participation of OM c-Cyts and the accelerated EET mediated by cell-secreted flavins may play an important role for the enhanced current generation in the presence of ATO nanoparticles. Moreover, it is worth noting that the TCA cycle in S. loihica PV-4 cells is activated by adding ATO nanoparticles, even if the potential is poised at +0.2 V, thereby also improving the EET process. The results presented here may provide a simple and effective strategy to boost the EET of S. loihica PV-4 cells, which is conducive to providing potential applications in bioelectrochemical systems.

Muscular activation during reverse and non-reverse chewing cycles in unilateral posterior crossbite.

PubMed

Piancino, Maria Grazia; Farina, Dario; Talpone, Francesca; Merlo, Andrea; Bracco, Pietro

2009-04-01

The aim of this study was to characterize the kinematics and masseter muscle activation in unilateral posterior crossbite. Eighty-two children (8.6 +/- 1.3 yr of age) with unilateral posterior crossbite and 12 children (8.9 +/- 0.6 yr of age) with normal occlusion were selected for the study. Electromyography (EMG) and kinematics were concurrently recorded during mastication of a soft bolus and a hard bolus. The percentage of reverse cycles in the group of patients was 59.0 +/- 33.1% (soft bolus) and 69.7 +/- 29.7% (hard bolus) when chewing on the crossbite side. When chewing on the non-affected side, the number of reverse cycles was 16.7 +/- 24.5% (soft bolus) and 16.7 +/- 22.3% (hard bolus). The reverse cycles on the crossbite side were narrower with respect to the cycles on the non-affected side. Although both types of cycles in patients resulted in lower EMG activity of the masseter of the crossbite side than of the contralateral masseter, the activity of the non-affected side was larger for reverse than for non-reverse cycles. It was concluded that when chewing on the crossbite side, the masseter activity is reduced on the mastication side (crossbite) and is unaltered (non-reverse cycles) or increased (reverse) on the non-affected side.

Impact of New Transport Infrastructure on Walking, Cycling, and Physical Activity.

PubMed

Panter, Jenna; Heinen, Eva; Mackett, Roger; Ogilvie, David

2016-02-01

Walking and cycling bring health and environmental benefits, but there is little robust evidence that changing the built environment promotes these activities in populations. This study evaluated the effects of new transport infrastructure on active commuting and physical activity. Quasi-experimental analysis nested within a cohort study. Four hundred and sixty-nine adult commuters, recruited through a predominantly workplace-based strategy, who lived within 30 kilometers of Cambridge, United Kingdom and worked in areas of the city to be served by the new transport infrastructure. The Cambridgeshire Guided Busway opened in 2011 and comprised a new bus network and a traffic-free walking and cycling route. Exposure to the intervention was defined using the shortest distance from each participant's home to the busway. Change in weekly time spent in active commuting between 2009 and 2012, measured by validated 7-day recall instrument. Secondary outcomes were changes in total weekly time spent walking and cycling and in recreational and overall physical activity, measured using the validated Recent Physical Activity Questionnaire. Data were analyzed in 2014. In multivariable multinomial regression models--adjusted for potential sociodemographic, geographic, health, and workplace confounders; baseline active commuting; and home or work relocation-exposure to the busway was associated with a significantly greater likelihood of an increase in weekly cycle commuting time (relative risk ratio=1.34, 95% CI=1.03, 1.76) and with an increase in overall time spent in active commuting among the least active commuters at baseline (relative risk ratio=1.76, 95% CI=1.16, 2.67). The study found no evidence of changes in recreational or overall physical activity. Providing new sustainable transport infrastructure was effective in promoting an increase in active commuting. These findings provide new evidence to support reconfiguring transport systems as part of public health improvement

DATA ASSIMILATION APPROACH FOR FORECAST OF SOLAR ACTIVITY CYCLES

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

Kitiashvili, Irina N., E-mail: irina.n.kitiashvili@nasa.gov

Numerous attempts to predict future solar cycles are mostly based on empirical relations derived from observations of previous cycles, and they yield a wide range of predicted strengths and durations of the cycles. Results obtained with current dynamo models also deviate strongly from each other, thus raising questions about criteria to quantify the reliability of such predictions. The primary difficulties in modeling future solar activity are shortcomings of both the dynamo models and observations that do not allow us to determine the current and past states of the global solar magnetic structure and its dynamics. Data assimilation is a relativelymore » new approach to develop physics-based predictions and estimate their uncertainties in situations where the physical properties of a system are not well-known. This paper presents an application of the ensemble Kalman filter method for modeling and prediction of solar cycles through use of a low-order nonlinear dynamo model that includes the essential physics and can describe general properties of the sunspot cycles. Despite the simplicity of this model, the data assimilation approach provides reasonable estimates for the strengths of future solar cycles. In particular, the prediction of Cycle 24 calculated and published in 2008 is so far holding up quite well. In this paper, I will present my first attempt to predict Cycle 25 using the data assimilation approach, and discuss the uncertainties of that prediction.« less

Medical students' and facilitators' experiences of an Early Professional Contact course: active and motivated students, strained facilitators.

PubMed

von Below, Bernhard; Hellquist, Gunilla; Rödjer, Stig; Gunnarsson, Ronny; Björkelund, Cecilia; Wahlqvist, Mats

2008-12-02

Today, medical students are introduced to patient contact, communication skills, and clinical examination in the preclinical years of the curriculum with the purpose of gaining clinical experience. These courses are often evaluated from the student perspective. Reports with an additional emphasis on the facilitator perspective are scarce. According to constructive alignment, an influential concept from research in higher education, the learning climate between students and teachers is also of great importance. In this paper, we approach the learning climate by studying both students' and facilitators' course experiences.In 2001, a new "Early Professional Contact" longitudinal strand through term 1-4, was introduced at the Sahlgrenska Academy, University of Gothenburg, Sweden. General practitioners and hospital specialists were facilitators.The aim of this study was to assess and analyse students' and clinical facilitators' experiences of the Early Professional Contact course and to illuminate facilitators' working conditions. Inspired by a Swedish adaptation of the Course Experience Questionnaire, an Early Professional Contact Questionnaire was constructed. In 2003, on the completion of the first longitudinal strand, a student and facilitator version was distributed to 86 students and 21 facilitators. In the analysis, both Chi-square and the Mann-Whitney tests were used. Sixty students (70%) and 15 facilitators (71%) completed the questionnaire. Both students and facilitators were satisfied with the course. Students reported gaining iiration for their future work as doctors along with increased confidence in meeting patients. They also reported increased motivation for biomedical studies. Differences in attitudes between facilitators and students were found. Facilitators experienced a greater workload, less reasonable demands and less support, than students. In this project, a new Early Professional Contact course was analysed from both student and facilitator

The use of actimetry to assess changes to the rest-activity cycle.

PubMed

Carvalho Bos, Sandra; Waterhouse, Jim; Edwards, Ben; Simons, Ries; Reilly, Thomas

2003-11-01

The endogenous circadian oscillator (the body clock) is slow to adjust to altered rest-activity patterns. As a result, several negative consequences arise during night work and after time-zone transitions. The process of adjustment can be assessed by measurements of the sleep electroencephalogram (EEG), core temperature or melatonin secretion, for example, but these techniques are very difficult to apply in field studies, and make very great demands upon both experimenters and subjects. We have sought to establish if the activity record, measured conveniently and unobtrusively by a monitor attached to the wrist, can be treated in ways that enable estimates to be made of the disruption caused by changes to the rest-activity cycle, and the process of adjustment to them. In Part A, we describe the calculation and assessment of a series of "activity indices" that measure the overall activity pattern, activity when out of bed or in bed, or the activity in the hours adjacent to going to bed or getting up. The value of the indices was assessed by measuring changes to them in subjects undergoing night work or undergoing time-zone transitions. In both cases, there is a large body of literature describing the changes that would be expected. First, night workers (working 2 to 4 successive night shifts) were investigated during rest days and night shifts. The indices indicated that night work was associated with lower activity when the subjects were out of bed and higher activity when in bed. Some indices also measured when subjects took an afternoon nap before starting a series of night shifts and gave information about the process of adjustment to night work and recovery from it. Second, in studies from travelers crossing six or more time zones to the east or west, the indices indicated that there were changes to the rest-activity cycle immediately after the flights, both in its overall profile and when activity of the subjects in bed or out of bed was considered, and that

The solar cycle variation of the rates of CMEs and related activity

NASA Technical Reports Server (NTRS)

Webb, David F.

1991-01-01

Coronal mass ejections (CMEs) are an important aspect of the physics of the corona and heliosphere. This paper presents results of a study of occurrence frequencies of CMEs and related activity tracers over more than a complete solar activity cycle. To properly estimate occurrence rates, observed CME rates must be corrected for instrument duty cycles, detection efficiencies away from the skyplane, mass detection thresholds, and geometrical considerations. These corrections are evaluated using CME data from 1976-1989 obtained with the Skylab, SMM and SOLWIND coronagraphs and the Helios-2 photometers. The major results are: (1) the occurrence rate of CMEs tends to track the activity cycle in both amplitude and phase; (2) the corrected rates from different instruments are reasonably consistent; and (3) over the long term, no one class of solar activity tracer is better correlated with CME rate than any other (with the possible exception of type II bursts).

Developing the Developers: Supporting and Researching the Learning of Professional Development Facilitators

ERIC Educational Resources Information Center

Perry, Emily; Boylan, Mark

2018-01-01

Research on teacher professional development is extensive but there are fewer studies about the practitioners who facilitate professional development. Here we report on a pilot programme for professional development facilitators rooted in a cycle of action research. Informed by a categorisation of professional knowledge and skills of facilitators,…

Forecasting the peak of the present solar activity cycle 24

NASA Astrophysics Data System (ADS)

Hamid, R. H.; Marzouk, B. A.

2018-06-01

Solar forecasting of the level of sun Activity is very important subject for all space programs. Most predictions are based on the physical conditions prevailing at or before the solar cycle minimum preceding the maximum in question. Our aim is to predict the maximum peak of cycle 24 using precursor techniques in particular those using spotless event, geomagnetic aamin. index and solar flux F10.7. Also prediction of exact date of the maximum (Tr) is taken in consideration. A study of variation over previous spotless event for cycles 7-23 and that for even cycles (8-22) are carried out for the prediction. Linear correlation between maximum of solar cycles (RM) and spotless event around the preceding minimum gives R24t = 88.4 with rise time Tr = 4.6 years. For the even cycles R24E = 77.9 with rise time Tr = 4.5 y's. Based on the average aamin. index for cycles (12-23), we estimate the expected amplitude for cycle 24 to be Raamin = 99.4 and 98.1 with time rise of Traamin = 4.04 & 4.3 years for both the total and even cycles in consecutive. The application of the data of solar flux F10.7 which cover only cycles (19-23) was taken in consideration and gives predicted maximum amplitude R24 10.7 = 126 with rise time Tr107 = 3.7 years, which are over estimation. Our result indicating to somewhat weaker of cycle 24 as compared to cycles 21-23.

Validity of Wearable Activity Monitors during Cycling and Resistance Exercise.

PubMed

Boudreaux, Benjamin D; Hebert, Edward P; Hollander, Daniel B; Williams, Brian M; Cormier, Corinne L; Naquin, Mildred R; Gillan, Wynn W; Gusew, Emily E; Kraemer, Robert R

2018-03-01

The use of wearable activity monitors has seen rapid growth; however, the mode and intensity of exercise could affect the validity of heart rate (HR) and caloric (energy) expenditure (EE) readings. There is a lack of data regarding the validity of wearable activity monitors during graded cycling regimen and a standard resistance exercise. The present study determined the validity of eight monitors for HR compared with an ECG and seven monitors for EE compared with a metabolic analyzer during graded cycling and resistance exercise. Fifty subjects (28 women, 22 men) completed separate trials of graded cycling and three sets of four resistance exercises at a 10-repetition-maximum load. Monitors included the following: Apple Watch Series 2, Fitbit Blaze, Fitbit Charge 2, Polar H7, Polar A360, Garmin Vivosmart HR, TomTom Touch, and Bose SoundSport Pulse (BSP) headphones. HR was recorded after each cycling intensity and after each resistance exercise set. EE was recorded after both protocols. Validity was established as having a mean absolute percent error (MAPE) value of ≤10%. The Polar H7 and BSP were valid during both exercise modes (cycling: MAPE = 6.87%, R = 0.79; resistance exercise: MAPE = 6.31%, R = 0.83). During cycling, the Apple Watch Series 2 revealed the greatest HR validity (MAPE = 4.14%, R = 0.80). The BSP revealed the greatest HR accuracy during resistance exercise (MAPE = 6.24%, R = 0.86). Across all devices, as exercise intensity increased, there was greater underestimation of HR. No device was valid for EE during cycling or resistance exercise. HR from wearable devices differed at different exercise intensities; EE estimates from wearable devices were inaccurate. Wearable devices are not medical devices, and users should be cautious when using these devices for monitoring physiological responses to exercise.

The potential role of postsynaptic phospholipase C activity in synaptic facilitation and behavioral sensitization in Aplysia.

PubMed

Fulton, Daniel; Condro, Michael C; Pearce, Kaycey; Glanzman, David L

2008-07-01

Previous findings indicate that synaptic facilitation, a cellular mechanism underlying sensitization of the siphon withdrawal response (SWR) in Aplysia, depends on a cascade of postsynaptic events, including activation of inositol triphosphate (IP3) receptors and release of Ca2+ from postsynaptic intracellular stores. These findings suggest that phospholipase C (PLC), the enzyme that catalyzes IP3 formation, may play an important role in postsynaptic signaling during facilitation and learning in Aplysia. Using the PLC inhibitor U73122, we found that PLC activity is required for synaptic facilitation following a 10-min treatment with 5-HT, as measured at 20 min after 5-HT washout. Prior work has indicated that facilitation at this time is supported primarily by postsynaptic processes. To determine whether postsynaptic PLC activity is involved in 5-HT-mediated facilitatory actions, we examined the effect of U73122 on enhancement of the response of motor neurons isolated in cell culture to glutamate, the sensory neuron transmitter. A 10-min application of 5-HT induced persistent (>40 min) enhancement of glutamate-evoked potentials (Glu-EPs) recorded from isolated motor neurons, and this enhancement was blocked by U73122. Finally, we showed that injecting U73122 into intact animals before behavioral training impaired intermediate-term sensitization, indicating that PLC activity contributes to this form of nonassociative learning.

Solar Activity Across the Scales: From Small-Scale Quiet-Sun Dynamics to Magnetic Activity Cycles

NASA Technical Reports Server (NTRS)

Kitiashvili, Irina N.; Collins, Nancy N.; Kosovichev, Alexander G.; Mansour, Nagi N.; Wray, Alan A.

2017-01-01

Observations as well as numerical and theoretical models show that solar dynamics is characterized by complicated interactions and energy exchanges among different temporal and spatial scales. It reveals magnetic self-organization processes from the smallest scale magnetized vortex tubes to the global activity variation known as the solar cycle. To understand these multiscale processes and their relationships, we use a two-fold approach: 1) realistic 3D radiative MHD simulations of local dynamics together with high resolution observations by IRIS, Hinode, and SDO; and 2) modeling of solar activity cycles by using simplified MHD dynamo models and mathematical data assimilation techniques. We present recent results of this approach, including the interpretation of observational results from NASA heliophysics missions and predictive capabilities. In particular, we discuss the links between small-scale dynamo processes in the convection zone and atmospheric dynamics, as well as an early prediction of Solar Cycle 25.

Solar activity across the scales: from small-scale quiet-Sun dynamics to magnetic activity cycles

NASA Astrophysics Data System (ADS)

Kitiashvili, I.; Collins, N.; Kosovichev, A. G.; Mansour, N. N.; Wray, A. A.

2017-12-01

Observations as well as numerical and theoretical models show that solar dynamics is characterized by complicated interactions and energy exchanges among different temporal and spatial scales. It reveals magnetic self-organization processes from the smallest scale magnetized vortex tubes to the global activity variation known as the solar cycle. To understand these multiscale processes and their relationships, we use a two-fold approach: 1) realistic 3D radiative MHD simulations of local dynamics together with high-resolution observations by IRIS, Hinode, and SDO; and 2) modeling of solar activity cycles by using simplified MHD dynamo models and mathematical data assimilation techniques. We present recent results of this approach, including the interpretation of observational results from NASA heliophysics missions and predictive capabilities. In particular, we discuss the links between small-scale dynamo processes in the convection zone and atmospheric dynamics, as well as an early prediction of Solar Cycle 25.

Adolescents' perspectives on the barriers and facilitators of physical activity: a systematic review of qualitative studies.

PubMed

Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

2015-10-01

This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of 'Web of Science', 'EBSCO', 'Psychinfo' and 'ERIC' databases was performed according to Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines. The following keywords were used: 'physical activity' and 'physical education', each one individually associated with 'correlate', 'determinant', 'facilitator', 'barrier', 'factor influen*', and with 'qualitative', 'focus group', 'interview', "narrative'. Out of 3815 studies initially identified, due to inclusion and quality criteria, only 12 were fully reviewed. Studies' outcomes were analyzed through thematic analysis. The majority of these reported research with young adolescent girls. Few studies have considered the socioeconomic status influence. According to young people's perspectives, the main facilitators and hampering factors to their participation in physical activity were the following: attitude toward physical activity; motivation; perceptions of competence and body image; fun; influence of friends, family and physical education teachers and environmental physical activity opportunities. Specific life transition periods were referred only as a barrier to physical activity. Strategies of pedagogical actions and for developing physical activity intervention programs were discussed, in order to effectively promote the adoption of active lifestyles among youth. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Identifying the barriers and facilitators to participation in physical activity for children with Down syndrome.

PubMed

Barr, M; Shields, N

2011-11-01

Many children with Down syndrome do not undertake the recommended amount of daily physical activity. The aim of this study was to explore the barriers and facilitators to physical activity for this group. Eighteen in-depth interviews were conducted with 20 parents (16 mothers, 4 fathers) of children with Down syndrome aged between 2 and 17 years to examine what factors facilitate physical activity and what factors are barriers to activity for their children. The participants were recruited through a community disability organisation that advocates for people with Down syndrome and their families. Interviews were recorded, transcribed and independently coded and analysed by two researchers using thematic analysis. Four themes on facilitators of physical activity were identified: (1) the positive role of the family; (2) opportunity for social interaction with peers; (3) structured accessible programmes that make adaptations for children with Down syndrome; and (4) children who were determined to succeed and physically skilled. Four themes on the barriers to physical activity were also identified: (1) characteristics commonly associated with Down syndrome; (2) competing family responsibilities; (3) reduced physical or behavioural skills; and (4) a lack of accessible programmes. The results highlight the important role of families in determining how much physical activity children with Down syndrome undertake and the effect that common characteristics associated with Down syndrome can have on maintaining an active lifestyle. Future research needs to concentrate on successful methods of encouraging physical activity, such as ensuring social interaction is part of the activity, and eliminating barriers to physical activity such as the a lack of appropriate programmes for children with Down syndrome. Implementing these strategies may encourage children with Down syndrome to participate more frequently in a physically active lifestyle. © 2011 The Authors. Journal of

Characteristics of Lower Leg Muscle Activity in Patients with Cerebral Palsy during Cycling on an Ergometer.

PubMed

Roy, Susmita; Alves-Pinto, Ana; Lampe, Renée

2018-01-01

Cycling on ergometer is often part of rehabilitation programs for patients with cerebral palsy (CP). The present study analyzed activity patterns of individual lower leg muscle during active cycling on ergometer in patients with CP and compared them to similar recordings in healthy participants. Electromyographic (EMG) recordings of lower leg muscle activity were collected from 14 adult patients and 10 adult healthy participants. Activity of the following muscles was recorded: Musculus tibialis anterior, Musculus gastrocnemius, Musculus rectus femoris, and Musculus biceps femoris. Besides qualitative analysis also quantitative analysis of individual muscle activity was performed by computing the coefficient of variation of EMG signal amplitude. More irregular EMG patterns were observed in patients in comparison to healthy participants: agonist-antagonist cocontractions were more frequent, muscle activity measured at specific points of the cycle path was more variable, and dynamic range of muscle activity along the cycle path was narrower in patients. Hypertonicity was also more frequent in patients. Muscle activity patterns during cycling differed substantially across patients. It showed irregular nature and occasional sharp high peaks. Dynamic range was also narrower than in controls. Observations underline the need for individualized cycling training to optimize rehabilitation effects.

Cycling for Students with ASD: Self-Regulation Promotes Sustained Physical Activity

ERIC Educational Resources Information Center

Todd, Teri; Reid, Greg; Butler-Kisber, Lynn

2010-01-01

Individuals with autism often lack motivation to engage in sustained physical activity. Three adolescents with severe autism participated in a 16-week program and each regularly completed 30 min of cycling at the end of program. This study investigated the effect of a self-regulation instructional strategy on sustained cycling, which included…

Computational Simulation of the Activation Cycle of Gα Subunit in the G Protein Cycle Using an Elastic Network Model

PubMed Central

Kim, Min Hyeok; Kim, Young Jin; Kim, Hee Ryung; Jeon, Tae-Joon; Choi, Jae Boong; Chung, Ka Young; Kim, Moon Ki

2016-01-01

Agonist-activated G protein-coupled receptors (GPCRs) interact with GDP-bound G protein heterotrimers (Gαβγ) promoting GDP/GTP exchange, which results in dissociation of Gα from the receptor and Gβγ. The GTPase activity of Gα hydrolyzes GTP to GDP, and the GDP-bound Gα interacts with Gβγ, forming a GDP-bound G protein heterotrimer. The G protein cycle is allosterically modulated by conformational changes of the Gα subunit. Although biochemical and biophysical methods have elucidated the structure and dynamics of Gα, the precise conformational mechanisms underlying the G protein cycle are not fully understood yet. Simulation methods could help to provide additional details to gain further insight into G protein signal transduction mechanisms. In this study, using the available X-ray crystal structures of Gα, we simulated the entire G protein cycle and described not only the steric features of the Gα structure, but also conformational changes at each step. Each reference structure in the G protein cycle was modeled as an elastic network model and subjected to normal mode analysis. Our simulation data suggests that activated receptors trigger conformational changes of the Gα subunit that are thermodynamically favorable for opening of the nucleotide-binding pocket and GDP release. Furthermore, the effects of GTP binding and hydrolysis on mobility changes of the C and N termini and switch regions are elucidated. In summary, our simulation results enabled us to provide detailed descriptions of the structural and dynamic features of the G protein cycle. PMID:27483005

Tamoxifen and ICI 182, 780 activate hypothalamic G protein-coupled estrogen receptor 1 to rapidly facilitate lordosis in female rats

PubMed Central

Long, Nathan; Long, Bertha; Mana, Asma; Le, Dream; Nguyen, Lam; Chokr, Sima; Sinchak, Kevin

2017-01-01

In the female rat, sexual receptivity (lordosis) can be facilitated by sequential activation of estrogen receptor (ER) α and G protein-coupled estrogen receptor 1 (GPER) by estradiol. In the estradiol benzoate (EB) primed ovariectomized (OVX) rat, EB initially binds to ERα in the plasma membrane that complexes with and transactivates metabotropic glutamate receptor 1a to activate β-endorphin neurons in the arcuate nucleus of the hypothalamus (ARH) that project to the medial preoptic nucleus (MPN). This activates MPN μ-opioid receptors (MOP), inhibiting lordosis. Infusion of non-esterified 17β-estradiol into the ARH rapidly reduces MPN MOP activation and facilitates lordosis via GPER. Tamoxifen (TAM) and ICI 182,780 (ICI) are selective estrogen receptor modulators that activate GPER. Therefore, we tested the hypothesis that TAM and ICI rapidly facilitate lordosis via activation of GPER in the ARH. Our first experiment demonstrated that injection of TAM intraperitoneal, or ICI into the lateral ventricle, deactivated MPN MOP and facilitated lordosis in EB-primed rats. We then tested whether TAM and ICI were acting rapidly through a GPER dependent pathway in the ARH. In EB-primed rats, ARH infusion of either TAM or ICI facilitated lordosis and reduced MPN MOP activation within 30 minutes compared to controls. These effects were blocked by pretreatment with the GPER antagonist, G15. Our findings demonstrate that TAM and ICI deactivate MPN MOP and facilitate lordosis in a GPER dependent manner. Thus, TAM and ICI may activate GPER in the CNS to produce estrogenic actions in neural circuits that modulate physiology and behavior. PMID:28063803

Tamoxifen and ICI 182,780 activate hypothalamic G protein-coupled estrogen receptor 1 to rapidly facilitate lordosis in female rats.

PubMed

Long, Nathan; Long, Bertha; Mana, Asma; Le, Dream; Nguyen, Lam; Chokr, Sima; Sinchak, Kevin

2017-03-01

In the female rat, sexual receptivity (lordosis) can be facilitated by sequential activation of estrogen receptor (ER) α and G protein-coupled estrogen receptor 1 (GPER) by estradiol. In the estradiol benzoate (EB) primed ovariectomized (OVX) rat, EB initially binds to ERα in the plasma membrane that complexes with and transactivates metabotropic glutamate receptor 1a to activate β-endorphin neurons in the arcuate nucleus of the hypothalamus (ARH) that project to the medial preoptic nucleus (MPN). This activates MPN μ-opioid receptors (MOP), inhibiting lordosis. Infusion of non-esterified 17β-estradiol into the ARH rapidly reduces MPN MOP activation and facilitates lordosis via GPER. Tamoxifen (TAM) and ICI 182,780 (ICI) are selective estrogen receptor modulators that activate GPER. Therefore, we tested the hypothesis that TAM and ICI rapidly facilitate lordosis via activation of GPER in the ARH. Our first experiment demonstrated that injection of TAM intraperitoneal, or ICI into the lateral ventricle, deactivated MPN MOP and facilitated lordosis in EB-primed rats. We then tested whether TAM and ICI were acting rapidly through a GPER dependent pathway in the ARH. In EB-primed rats, ARH infusion of either TAM or ICI facilitated lordosis and reduced MPN MOP activation within 30min compared to controls. These effects were blocked by pretreatment with the GPER antagonist, G15. Our findings demonstrate that TAM and ICI deactivate MPN MOP and facilitate lordosis in a GPER dependent manner. Thus, TAM and ICI may activate GPER in the CNS to produce estrogenic actions in neural circuits that modulate physiology and behavior. Published by Elsevier Inc.

Perceived barriers and facilitators to participation in physical activity for children with disability: a qualitative study.

PubMed

Shields, Nora; Synnot, Anneliese

2016-01-19

Children with disability engage in less physical activity compared to their typically developing peers. Our aim was to explore the barriers and facilitators to participation in physical activity for this group. Ten focus groups, involving 63 participants (23 children with disability, 20 parents of children with disability and 20 sport and recreation staff), were held to explore factors perceived as barriers and facilitators to participation in physical activity by children with disability. Data were analysed thematically by two researchers. Four themes were identified: (1) similarities and differences, (2) people make the difference, (3) one size does not fit all, and (4) communication and connections. Key facilitators identified were the need for inclusive pathways that encourage ongoing participation as children grow or as their skills develop, and for better partnerships between key stakeholders from the disability, sport, education and government sectors. Children with disabilities' need for the early attainment of motor and social skills and the integral role of their families in supporting them were considered to influence their participation in physical activity. Children with disability were thought to face additional barriers to participation compared to children with typical development including a lack of instructor skills and unwillingness to be inclusive, negative societal attitudes towards disability, and a lack of local opportunities. The perspectives gathered in this study are relevant to the many stakeholders involved in the design and implementation of effective interventions, strategies and policies to promote participation in physical activity for children with disability. We outline ten strategies for facilitating participation.

A vigorous activity cycle mimicking a planetary system in HD 200466

NASA Astrophysics Data System (ADS)

Carolo, E.; Desidera, S.; Gratton, R.; Martinez Fiorenzano, A. F.; Marzari, F.; Endl, M.; Mesa, D.; Barbieri, M.; Cecconi, M.; Claudi, R. U.; Cosentino, R.; Scuderi, S.

2014-07-01

Stellar activity can be a source of radial velocity (RV) noise and can reproduce periodic RV variations similar to those produced by an exoplanet. We present the vigorous activity cycle in the primary of the visual binary HD 200466, a system made of two almost identical solar-type stars with an apparent separation of 4.6 arcsec at a distance of 44 ± 2 pc. High precision RV over more than a decade, adaptive optics (AO) images, and abundances have been obtained for both components. A linear trend in the RV is found for the secondary. We assumed that it is due to the binary orbit and once coupled with the astrometric data, it strongly constrains the orbital solution of the binary at high eccentricities (e ~ 0.85) and quite small periastron of ~21 AU. If this orbital motion is subtracted from the primary radial velocity curve, a highly significant (false alarm probability <0.1%) period of about 1300 d is obtained, suggesting in a first analysis the presence of a giant planet, but it turned out to be due to the stellar activity cycle. Since our spectra do not include the Ca II resonance lines, we measured a chromospheric activity indicator based on the Hα line to study the correlation between activity cycles and long-term activity variations. While the bisector analysis of the line profile does not show a clear indication of activity, the correlation between the Hα line indicator and the RV measurements identify the presence of a strong activity cycle. Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the Istituto Nazionale di Astrofisica (INAF) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.Tables 5 and 6 are available in electronic form at http://www.aanda.org

Understanding the challenges to facilitating active learning in the resident conferences: a qualitative study of internal medicine faculty and resident perspectives

PubMed Central

Sawatsky, Adam P.; Zickmund, Susan L.; Berlacher, Kathryn; Lesky, Dan; Granieri, Rosanne

2015-01-01

Background In the Next Accreditation System, the Accreditation Council for Graduate Medical Education outlines milestones for medical knowledge and requires regular didactic sessions in residency training. There are many challenges to facilitating active learning in resident conferences, and we need to better understand resident learning preferences and faculty perspectives on facilitating active learning. The goal of this study was to identify challenges to facilitating active learning in resident conferences, both through identifying specific implementation barriers and identifying differences in perspective between faculty and residents on effective teaching and learning strategies. Methods The investigators invited core residency faculty to participate in focus groups. The investigators used a semistructured guide to facilitate discussion about learning preferences and teaching perspectives in the conference setting and used an ‘editing approach’ within a grounded theory framework to qualitative analysis to code the transcripts and analyze the results. Data were compared to previously collected data from seven resident focus groups. Results Three focus groups with 20 core faculty were conducted. We identified three domains pertaining to facilitating active learning in resident conferences: barriers to facilitating active learning formats, similarities and differences in faculty and resident learning preferences, and divergence between faculty and resident opinions about effective teaching strategies. Faculty identified several setting, faculty, and resident barriers to facilitating active learning in resident conferences. When compared to residents, faculty expressed similar learning preferences; the main differences were in motivations for conference attendance and type of content. Resident preferences and faculty perspectives differed on the amount of information appropriate for lecture and the role of active participation in resident conferences

Understanding the challenges to facilitating active learning in the resident conferences: a qualitative study of internal medicine faculty and resident perspectives.

PubMed

Sawatsky, Adam P; Zickmund, Susan L; Berlacher, Kathryn; Lesky, Dan; Granieri, Rosanne

2015-01-01

Background In the Next Accreditation System, the Accreditation Council for Graduate Medical Education outlines milestones for medical knowledge and requires regular didactic sessions in residency training. There are many challenges to facilitating active learning in resident conferences, and we need to better understand resident learning preferences and faculty perspectives on facilitating active learning. The goal of this study was to identify challenges to facilitating active learning in resident conferences, both through identifying specific implementation barriers and identifying differences in perspective between faculty and residents on effective teaching and learning strategies. Methods The investigators invited core residency faculty to participate in focus groups. The investigators used a semistructured guide to facilitate discussion about learning preferences and teaching perspectives in the conference setting and used an 'editing approach' within a grounded theory framework to qualitative analysis to code the transcripts and analyze the results. Data were compared to previously collected data from seven resident focus groups. Results Three focus groups with 20 core faculty were conducted. We identified three domains pertaining to facilitating active learning in resident conferences: barriers to facilitating active learning formats, similarities and differences in faculty and resident learning preferences, and divergence between faculty and resident opinions about effective teaching strategies. Faculty identified several setting, faculty, and resident barriers to facilitating active learning in resident conferences. When compared to residents, faculty expressed similar learning preferences; the main differences were in motivations for conference attendance and type of content. Resident preferences and faculty perspectives differed on the amount of information appropriate for lecture and the role of active participation in resident conferences. Conclusion

Understanding the challenges to facilitating active learning in the resident conferences: a qualitative study of internal medicine faculty and resident perspectives.

PubMed

Sawatsky, Adam P; Zickmund, Susan L; Berlacher, Kathryn; Lesky, Dan; Granieri, Rosanne

2015-01-01

In the Next Accreditation System, the Accreditation Council for Graduate Medical Education outlines milestones for medical knowledge and requires regular didactic sessions in residency training. There are many challenges to facilitating active learning in resident conferences, and we need to better understand resident learning preferences and faculty perspectives on facilitating active learning. The goal of this study was to identify challenges to facilitating active learning in resident conferences, both through identifying specific implementation barriers and identifying differences in perspective between faculty and residents on effective teaching and learning strategies. The investigators invited core residency faculty to participate in focus groups. The investigators used a semistructured guide to facilitate discussion about learning preferences and teaching perspectives in the conference setting and used an 'editing approach' within a grounded theory framework to qualitative analysis to code the transcripts and analyze the results. Data were compared to previously collected data from seven resident focus groups. Three focus groups with 20 core faculty were conducted. We identified three domains pertaining to facilitating active learning in resident conferences: barriers to facilitating active learning formats, similarities and differences in faculty and resident learning preferences, and divergence between faculty and resident opinions about effective teaching strategies. Faculty identified several setting, faculty, and resident barriers to facilitating active learning in resident conferences. When compared to residents, faculty expressed similar learning preferences; the main differences were in motivations for conference attendance and type of content. Resident preferences and faculty perspectives differed on the amount of information appropriate for lecture and the role of active participation in resident conferences. This study highlights several

Using Group Drawings Activities to Facilitate the Understanding of the Systemic Aspects of Projects

ERIC Educational Resources Information Center

Arantes do Amaral, João Alberto; Hess, Aurélio; Gonçalves, Paulo; Rodrigues, Vinícius Picanço

2017-01-01

In this article, we present our findings regarding promoting group drawing activities in order to facilitate the learning of systemic aspects of projects. We discuss the approach we used to engage the students and foster learning in our classes. We used group drawing activities in two project management undergraduate courses. The courses, which…

Patients with schizophrenia activate behavioural intentions facilitated by counterfactual reasoning

PubMed Central

Tebé, Cristian; Benejam, Bessy; Caño, Agnes; Menchón, José Manuel

2017-01-01

Previous research has associated schizophrenia with an inability to activate behavioural intentions facilitated by counterfactual thinking (CFT) as a step to improving performance. Consequently, these findings suggest that rehabilitation strategies will be entirely ineffective. To extend previous research, we evaluated the influence of CFT in the activation of behavioural intentions using a novel sequential priming paradigm in the largest sample of subjects explored to date. Method The main variables assessed were: answer to complete a target task (wrong or correctly), and percentage gain in the reaction time (RT) to complete a target task correctly depending on whether the prime was a counterfactual or a neutral-control cue. These variables were assessed in 37 patients with schizophrenia and 37 healthy controls. Potential associations with clinical status and socio-demographic characteristics were also explored. Results When a counterfactual prime was presented, the probability of giving an incorrect answer was lower for the entire sample than when a neutral prime was presented (OR 0.58; CI 95% 0.42 to 0.79), but the schizophrenia patients showed a higher probability than the controls of giving an incorrect answer (OR 3.89; CI 95% 2.0 to 7.6). Both the schizophrenia patients and the controls showed a similar percentage gain in RT to a correct answer of 8%. Conclusions Challenging the results of previous research, our findings suggest a normal activation of behavioural intentions facilitated by CFT in schizophrenia. Nevertheless, the patients showed more difficulty than the controls with the task, adding support to the concept of CFT as a potential new target for consideration in future therapeutic approaches for this illness. PMID:28586400

Ethanol-mediated facilitation of AMPA receptor function in the dorsomedial striatum: implications for alcohol drinking behavior.

PubMed

Wang, Jun; Ben Hamida, Sami; Darcq, Emmanuel; Zhu, Wenheng; Gibb, Stuart L; Lanfranco, Maria Fe; Carnicella, Sebastien; Ron, Dorit

2012-10-24

We found previously that acute ex vivo as well as repeated cycles of in vivo ethanol exposure and withdrawal, including excessive voluntary consumption of ethanol, produces a long-lasting increase in the activity of NR2B-containing NMDA receptors (NR2B-NMDARs) in the dorsomedial striatum (DMS) of rats (Wang et al., 2010a). Activation of NMDARs is required for the induction of long-term potentiation (LTP) of AMPA receptor (AMPAR)-mediated synaptic response. We therefore examined whether the ethanol-mediated upregulation of NMDAR activity alters the induction of LTP in the DMS. We found that ex vivo acute exposure of striatal slices to, and withdrawal from, ethanol facilitates the induction of LTP in DMS neurons, which is abolished by the inhibition of NR2B-NMDARs. We also report that repeated systemic administration of ethanol causes an NR2B-NMDAR-dependent facilitation of LTP in the DMS. LTP is mediated by the insertion of AMPAR subunits into the synaptic membrane, and we found that repeated systemic administration of ethanol, as well as cycles of excessive ethanol consumption and withdrawal, produced a long-lasting increase in synaptic localization of the GluR1 and GluR2 subunits of AMPARs in the DMS. Importantly, we report that inhibition of AMPARs in the DMS attenuates operant self-administration of ethanol, but not of sucrose. Together, our data suggest that aberrant synaptic plasticity in the DMS induced by repeated cycles of ethanol exposure and withdrawal contributes to the molecular mechanisms underlying the development and/or maintenance of excessive ethanol consumption.

Lower Extremity Muscle Activity during Cycling in Adolescents with and without Cerebral Palsy

PubMed Central

Lauer, Richard T.; Johnston, Therese E.; Smith, Brian T.; Lee, Samuel C.K.

2008-01-01

Background In individuals with cerebral palsy (CP), adaptation and plasticity in the neuromuscular system can lead to detrimental changes affecting gait. Cycling may be an effective method to improve mobility. The biomechanics of cycling in adolescents with CP have been studied, but further analysis of the frequency and amplitude characteristics of the electromyographic (EMG) signals can assist with interpretation of the cycling kinematics. Methods Data were analyzed from ten adolescents with typical development (TD) (mean = 14.9 SD = 1.4 years) and ten adolescents with CP (mean = 15.6 SD = 1.8 years) as they cycled at two different cadences. Analyses of the lower extremity EMG signals involved frequency and amplitude analysis across the cycling revolution. Findings Examination of cycling cadence revealed that adolescents with CP had altered EMG characteristics in comparison to adolescents with typical development across the entire crank revolution for all muscles. Analyses of individual muscles indicated both inappropriate muscle activation and weakness. Interpretation A more comprehensive analysis of EMG activity has the potential to provide insight into how a task is accomplished. In this study, the control of the several muscles, especially the rectus femoris, was significantly different in adolescents with cerebral palsy. This, combined with muscle weakness, may have contributed to the observed deviations in joint kinematics. Interventions that increase muscle strength with feedback to the nervous system about appropriate activation timing may be beneficial to allow individuals with CP to cycle more efficiently. PMID:18082920

Facilitators and Barriers to Performing Activities and Participation in Children With Cerebral Palsy: Caregivers' Perspective.

PubMed

Earde, Pinailug Tantilipikorn; Praipruk, Aina; Rodpradit, Phanlerd; Seanjumla, Parichad

2018-01-01

To investigate contextual factors that were facilitators and barriers to performing activity and participation for children with cerebral palsy from the caregivers' perspective. Qualitative in-depth interview with primary caregivers of children with cerebral palsy aged 4 to 12 years was conducted in the metropolitan area of Thailand. Semistructured questions related to environmental and personal factors were recorded. Interviews were transcribed verbatim and analyzed for main themes on the basis of the International Classification of Functioning, Disability, and Health-Children and Youth Version (ICF-CY) classification. Twenty-seven caregivers participated. Facilitators were appropriateness of assistive devices, support and acceptance from family, friends, and society, health services, willingness, and self-acceptance. Barriers were inappropriate design and facilities, overprotection of family, nonacceptance from family, friends, and society, inconvenient transportation, financial problems, limited health services, limited access to education, frustration, and being an introvert. Contextual factors that can be facilitators and barriers to perform activities and participation should be considered for improving lives of children with cerebral palsy.

Stochastic cycle selection in active flow networks

NASA Astrophysics Data System (ADS)

Woodhouse, Francis; Forrow, Aden; Fawcett, Joanna; Dunkel, Jorn

2016-11-01

Active biological flow networks pervade nature and span a wide range of scales, from arterial blood vessels and bronchial mucus transport in humans to bacterial flow through porous media or plasmodial shuttle streaming in slime molds. Despite their ubiquity, little is known about the self-organization principles that govern flow statistics in such non-equilibrium networks. By connecting concepts from lattice field theory, graph theory and transition rate theory, we show how topology controls dynamics in a generic model for actively driven flow on a network. Through theoretical and numerical analysis we identify symmetry-based rules to classify and predict the selection statistics of complex flow cycles from the network topology. Our conceptual framework is applicable to a broad class of biological and non-biological far-from-equilibrium networks, including actively controlled information flows, and establishes a new correspondence between active flow networks and generalized ice-type models.

Non-Critical-Care Nurses' Perceptions of Facilitators and Barriers to Rapid Response Team Activation.

PubMed

Jenkins, Sheryl Henry; Astroth, Kim Schafer; Woith, Wendy Mann

2015-01-01

Rapid response teams can save lives but are only effective when activated. We surveyed 50 nurses for their perceptions of facilitators and barriers to activation. Findings showed that participants need more education on their role and when to activate the rapid response team. Nurses who comprise the team need help building their communication skills. We recommend nursing professional development specialists increase the frequency of offerings and expand the focus on roles, activation criteria, and communication skills.

Beliefs, Barriers and Facilitators to Physical Activity in Bariatric Surgery Candidates.

PubMed

Zabatiero, Juliana; Hill, Kylie; Gucciardi, Daniel F; Hamdorf, Jeffrey M; Taylor, Susan F; Hagger, Martin S; Smith, Anne

2016-05-01

Bariatric surgery candidates engage in less physical activity (PA) and spend longer periods in sedentary behaviour (SB) when compared to the general adult population. The aim of this study was to explore the beliefs about PA and perceived barriers and facilitators to PA in obese adults scheduled for bariatric surgery. Nineteen obese adults (15 females), with a mean (SD) age of 41.6 (12.1) years, weight of 119.2 (20.5) kg and body mass index of 41.6 (6.7) kg/m(2) participated in a one-on-one in-depth qualitative interview before undergoing bariatric surgery. Data were analysed using inductive thematic analysis. Most participants believed that engaging in regular PA confers important health benefits, however reported insufficient PA levels to obtain those benefits. The perceived barriers to PA reported by participants were both obesity related (e.g. bodily pain, physical limitation and self-presentational concerns) and non-obesity related (e.g. lack of motivation, environment and restricted resources). All participants stated weight loss to be the main perceived facilitator to PA, together with social factors, better time management and access to financial resources. In bariatric surgery candidates, many of the perceived barriers and facilitators to PA are not obesity related and are therefore unlikely to change as a result of bariatric surgery. This may explain why earlier research shows little change in PA or SB following surgery. It is likely that an approach that aims to address the barriers and facilitators identified in this study is needed to change the inactive lifestyle adopted in this population.

OpenSim-Supported Virtual Learning Environment: Transformative Content Representation, Facilitation, and Learning Activities

ERIC Educational Resources Information Center

Kim, Heesung; Ke, Fengfeng

2016-01-01

The pedagogical and design considerations for the use of a virtual reality (VR) learning environment are important for prospective and current teachers. However, empirical research investigating how preservice teachers interact with transformative content representation, facilitation, and learning activities in a VR educational simulation is still…

Co-creating Emotionally Safe Environments at Camp: Training Staff To Facilitate Adventure Activities.

ERIC Educational Resources Information Center

Brownlee, Matt; Yerkes, Rita

2003-01-01

An emotionally safe environment helps campers participate in adventure activities. Staff development tips for creating a safe environment include using cooperative goal setting; using parallel training processes; developing working lesson plans that outline facilitation techniques for creating emotionally safe environments; and using co-created…

Centriole maturation requires regulated Plk1 activity during two consecutive cell cycles.

PubMed

Kong, Dong; Farmer, Veronica; Shukla, Anil; James, Jana; Gruskin, Richard; Kiriyama, Shigeo; Loncarek, Jadranka

2014-09-29

Newly formed centrioles in cycling cells undergo a maturation process that is almost two cell cycles long before they become competent to function as microtubule-organizing centers and basal bodies. As a result, each cell contains three generations of centrioles, only one of which is able to form cilia. It is not known how this long and complex process is regulated. We show that controlled Plk1 activity is required for gradual biochemical and structural maturation of the centrioles and timely appendage assembly. Inhibition of Plk1 impeded accumulation of appendage proteins and appendage formation. Unscheduled Plk1 activity, either in cycling or interphase-arrested cells, accelerated centriole maturation and appendage and cilia formation on the nascent centrioles, erasing the age difference between centrioles in one cell. These findings provide a new understanding of how the centriole cycle is regulated and how proper cilia and centrosome numbers are maintained in the cells.

Centriole maturation requires regulated Plk1 activity during two consecutive cell cycles

PubMed Central

Kong, Dong; Farmer, Veronica; Shukla, Anil; James, Jana; Gruskin, Richard; Kiriyama, Shigeo

2014-01-01

Newly formed centrioles in cycling cells undergo a maturation process that is almost two cell cycles long before they become competent to function as microtubule-organizing centers and basal bodies. As a result, each cell contains three generations of centrioles, only one of which is able to form cilia. It is not known how this long and complex process is regulated. We show that controlled Plk1 activity is required for gradual biochemical and structural maturation of the centrioles and timely appendage assembly. Inhibition of Plk1 impeded accumulation of appendage proteins and appendage formation. Unscheduled Plk1 activity, either in cycling or interphase-arrested cells, accelerated centriole maturation and appendage and cilia formation on the nascent centrioles, erasing the age difference between centrioles in one cell. These findings provide a new understanding of how the centriole cycle is regulated and how proper cilia and centrosome numbers are maintained in the cells. PMID:25246616

IGF-1 facilitates thrombopoiesis primarily through Akt activation.

PubMed

Chen, Shilei; Hu, Mengjia; Shen, Mingqiang; Wang, Song; Wang, Cheng; Chen, Fang; Tang, Yong; Wang, Xinmiao; Zeng, Hao; Chen, Mo; Gao, Jining; Wang, Fengchao; Su, Yongping; Xu, Yang; Wang, Junping

2018-05-25

It is known that insulin-like growth factor-1 (IGF-1) also functions as a hematopoietic factor, while its direct effect on thrombopoiesis remains unclear. In this study, we show that IGF-1 is able to promote CD34+ cell differentiation toward megakaryocytes (MKs), as well as the facilitation of proplatelet formation (PPF) and platelet production from cultured MKs. The in vivo study demonstrates that IGF-1 administration accelerates platelet recovery in mice after 6.0Gy of irradiation and in mice that received bone marrow transplantation (BMT) following 10.0Gy of lethal irradiation. Subsequent investigations reveal that ERK1/2 and Akt activation mediate the effect of IGF-1 on thrombopoiesis. Notably, Akt activation induced by IGF-1 is more apparent than that of ERK1/2, compared with that of thrombopoietin (TPO) treatment. Moreover, the effect of IGF-1 on thrombopoiesis is independent of TPO signaling, because IGF-1 treatment can also lead to a significant increase of platelet counts in homozygous TPO receptor mutant mice. Further analysis indicates that the activation of Akt triggered by IGF-1 requires the assistance of steroid receptor coactivator-3 (SRC-3). Therefore, our data reveal a distinct role of IGF-1 in regulating thrombopoiesis, providing new insights into TPO-independent regulation of platelet generation. Copyright © 2018 American Society of Hematology.

Motivators, Facilitators, and Barriers to Physical Activity in Older Adults: A Qualitative Study.

PubMed

Miller, Wendy; Brown, Patrick R

In this descriptive, qualitative research study, the researchers used semistructured interviews with older adults who engaged in regular physical activity to identify common motivators, facilitators, and barriers to participating in regular exercise. The authors used these interviews to identify major themes and discuss implications for population health.

Stochastic cycle selection in active flow networks.

PubMed

Woodhouse, Francis G; Forrow, Aden; Fawcett, Joanna B; Dunkel, Jörn

2016-07-19

Active biological flow networks pervade nature and span a wide range of scales, from arterial blood vessels and bronchial mucus transport in humans to bacterial flow through porous media or plasmodial shuttle streaming in slime molds. Despite their ubiquity, little is known about the self-organization principles that govern flow statistics in such nonequilibrium networks. Here we connect concepts from lattice field theory, graph theory, and transition rate theory to understand how topology controls dynamics in a generic model for actively driven flow on a network. Our combined theoretical and numerical analysis identifies symmetry-based rules that make it possible to classify and predict the selection statistics of complex flow cycles from the network topology. The conceptual framework developed here is applicable to a broad class of biological and nonbiological far-from-equilibrium networks, including actively controlled information flows, and establishes a correspondence between active flow networks and generalized ice-type models.

Stochastic cycle selection in active flow networks

PubMed Central

Woodhouse, Francis G.; Forrow, Aden; Fawcett, Joanna B.; Dunkel, Jörn

2016-01-01

Active biological flow networks pervade nature and span a wide range of scales, from arterial blood vessels and bronchial mucus transport in humans to bacterial flow through porous media or plasmodial shuttle streaming in slime molds. Despite their ubiquity, little is known about the self-organization principles that govern flow statistics in such nonequilibrium networks. Here we connect concepts from lattice field theory, graph theory, and transition rate theory to understand how topology controls dynamics in a generic model for actively driven flow on a network. Our combined theoretical and numerical analysis identifies symmetry-based rules that make it possible to classify and predict the selection statistics of complex flow cycles from the network topology. The conceptual framework developed here is applicable to a broad class of biological and nonbiological far-from-equilibrium networks, including actively controlled information flows, and establishes a correspondence between active flow networks and generalized ice-type models. PMID:27382186

A movie of the RNA polymerase nucleotide addition cycle.

PubMed

Brueckner, Florian; Ortiz, Julio; Cramer, Patrick

2009-06-01

During gene transcription, RNA polymerase (Pol) passes through repetitive cycles of adding a nucleotide to the growing mRNA chain. Here we obtained a movie of the nucleotide addition cycle by combining structural information on different functional states of the Pol II elongation complex (EC). The movie illustrates the two-step loading of the nucleoside triphosphate (NTP) substrate, closure of the active site for catalytic nucleotide incorporation, and the presumed two-step translocation of DNA and RNA, which is accompanied by coordinated conformational changes in the polymerase bridge helix and trigger loop. The movie facilitates teaching and a mechanistic analysis of transcription and can be downloaded from http://www.lmb.uni-muenchen.de/cramer/pr-materials.

Integration of a 'proton antenna' facilitates transport activity of the monocarboxylate transporter MCT4.

PubMed

Noor, Sina Ibne; Pouyssegur, Jacques; Deitmer, Joachim W; Becker, Holger M

2017-01-01

Monocarboxylate transporters (MCTs) mediate the proton-coupled transport of high-energy metabolites like lactate and pyruvate and are expressed in nearly every mammalian tissue. We have shown previously that transport activity of MCT4 is enhanced by carbonic anhydrase II (CAII), which has been suggested to function as a 'proton antenna' for the transporter. In the present study, we tested whether creation of an endogenous proton antenna by introduction of a cluster of histidine residues into the C-terminal tail of MCT4 (MCT4-6xHis) could facilitate MCT4 transport activity when heterologously expressed in Xenopus oocytes. Our results show that integration of six histidines into the C-terminal tail does indeed increase transport activity of MCT4 to the same extent as did coexpression of MCT4-WT with CAII. Transport activity of MCT4-6xHis could be further enhanced by coexpression with extracellular CAIV, but not with intracellular CAII. Injection of an antibody against the histidine cluster into MCT4-expressing oocytes decreased transport activity of MCT4-6xHis, while leaving activity of MCT4-WT unaltered. Taken together, these findings suggest that transport activity of the proton-coupled monocarboxylate transporter MCT4 can be facilitated by integration of an endogenous proton antenna into the transporter's C-terminal tail. © 2016 Federation of European Biochemical Societies.

Constitutively active 5-HT2/α1 receptors facilitate muscle spasms after human spinal cord injury

PubMed Central

D'Amico, Jessica M.; Murray, Katherine C.; Li, Yaqing; Chan, K. Ming; Finlay, Mark G.; Bennett, David J.

2013-01-01

In animals, the recovery of motoneuron excitability in the months following a complete spinal cord injury is mediated, in part, by increases in constitutive serotonin (5-HT2) and norepinephrine (α1) receptor activity, which facilitates the reactivation of calcium-mediated persistent inward currents (CaPICs) without the ligands serotonin and norepinephrine below the injury. In this study we sought evidence for a similar role of constitutive monoamine receptor activity in the development of spasticity in human spinal cord injury. In chronically injured participants with partially preserved sensory and motor function, the serotonin reuptake inhibitor citalopram facilitated long-lasting reflex responses (spasms) previously shown to be mediated by CaPICs, suggesting that in incomplete spinal cord injury, functional descending sources of monoamines are present to activate monoamine receptors below the lesion. However, in participants with motor or motor/sensory complete injuries, the inverse agonist cyproheptadine, which blocks both ligand and constitutive 5-HT2/α1 receptor activity, decreased long-lasting reflexes, whereas the neutral antagonist chlorpromazine, which only blocks ligand activation of these receptors, had no effect. When tested in noninjured control participants having functional descending sources of monoamines, chlorpromazine was effective in reducing CaPIC-mediated motor unit activity. On the basis of these combined results, it appears that in severe spinal cord injury, facilitation of persistent inward currents and muscle spasms is mainly mediated by the activation of constitutive 5-HT2 and α1 receptor activity. Drugs that more selectively block these constitutively active monoamine receptors may provide better oral control of spasticity, especially in motor complete spinal cord injury where reducing motoneuron excitability is the primary goal. PMID:23221402

The Solar Cycle.

PubMed

Hathaway, David H

The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24. Supplementary material is available for this article at 10.1007/lrsp-2015-4.

An exploratory study of how sports and recreation industry personnel perceive the barriers and facilitators of physical activity in children with disability.

PubMed

Shields, Nora; Synnot, Anneliese J

2014-01-01

To explore the perceived barriers and facilitators to participation in physical activity among children with disability in physical activity and community sports from the perspective of sports and recreation industry personnel. A convenient sample of 24 participants was recruited from delegates attending a symposium on physical activity for organisations in the sport and recreation sector in Victoria, Australia. The participants completed a brief questionnaire. Data were analysed by content analysis using an inductive approach. The participants reported 25 facilitators and 20 barriers to participation for children with disability. The top five reported facilitators were: welcoming providers, support and encouragement from parents or others, inclusive providers, adaptable approaches and accessibility of facilities. The top five reported barriers were: inaccessible facilities, non-inclusive providers, transport, lack of relevant opportunities and cost. Sports industry personnel share a similar perspective to families of potential barriers and facilitators to engagement by children with disability in physical activity and community sports. Policy change was not considered as a facilitator of physical activity, even though four of the top five facilitators identified could be implemented through local policy change. Implications for Rehabilitation There are multiple factors that interact with each other which influence the participation by children with disability in physical activity and community sports. The sports and recreation industry should consider policy change as a relevant way to facilitate participation by children with disability in physical activity. More professional development and disability engagement opportunities for sports and recreation industry personnel may help address some of the barriers to participation for children with disability experience.

A new simple dynamo model for solar activity cycle

NASA Astrophysics Data System (ADS)

Yokoi, Nobumitsu; Schmitt, Dieter

2015-04-01

The solar magnetic activity cycle has been investigated in an elaborated manner with several types of dynamo models [1]. In most of the current mean-field approaches, the inhomogeneity of the large-scale flow is treated as an essential ingredient in the mean magnetic field equation whereas it is completely neglected in the turbulence equation. In this work, a new simple model for the solar activity cycle is proposed. The present model differs from the previous ones mainly in two points. First, in addition to the helicity coefficient α, we consider a term related to the cross helicity, which represents the effect of the inhomogeneous mean flow, in the turbulent electromotive force [2, 3]. Second, this transport coefficient (γ) is not treated as an adjustable parameter, but the evolution equation for γ is simultaneously solved. The basic scenario for the solar activity cycle in this approach is as follows: The toroidal field is induced by the toroidal rotation in mediation by the turbulent cross helicity. Then due to the α or helicity effect, the poloidal field is generated from the toroidal field. The poloidal field induced by the α effect produces a turbulent cross helicity whose sign is opposite to the original one (negative cross-helicity production). The cross helicity with this opposite sign induces a reversed toroidal field. Results of the eigenvalue analysis of the model equations are shown, which confirm the above scenario. References [1] Charbonneau, Living Rev. Solar Phys. 7, 3 (2010). [2] Yoshizawa, A. Phys. Fluids B 2, 1589 (1990). [3] Yokoi, N. Geophys. Astrophys. Fluid Dyn. 107, 114 (2013).

Sunspot Activity Near Cycle Minimum and What it Might Suggest for Cycle 24, the Next Sunspot Cycle

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2009-01-01

In late 2008, 12-month moving averages of sunspot number, number of spotless days, number of groups, area of sunspots, and area per group were reflective of sunspot cycle minimum conditions for cycle 24, these values being of or near record value. The first spotless day occurred in January 2004 and the first new-cycle, high-latitude spot was reported in January 2008, although old-cycle, low-latitude spots have continued to be seen through April 2009, yielding an overlap of old and new cycle spots of at least 16 mo. New-cycle spots first became dominant over old-cycle spots in September 2008. The minimum value of the weighted mean latitude of sunspots occurred in May 2007, measuring 6.6 deg, and the minimum value of the highest-latitude spot followed in June 2007, measuring 11.7 deg. A cycle length of at least 150 mo is inferred for cycle 23, making it the longest cycle of the modern era. Based on both the maximum-minimum and amplitude-period relationships, cycle 24 is expected to be only of average to below-average size, peaking probably in late 2012 to early 2013, unless it proves to be a statistical outlier.

The role of circulating sex hormones in menstrual cycle dependent modulation of pain-related brain activation

PubMed Central

Veldhuijzen, Dieuwke S.; Keaser, Michael L.; Traub, Deborah S.; Zhuo, Jiachen; Gullapalli, Rao P.; Greenspan, Joel D.

2013-01-01

Sex differences in pain sensitivity have been consistently found but the basis for these differences is incompletely understood. The present study assessed how pain-related neural processing varies across the menstrual cycle in normally cycling, healthy females, and whether menstrual cycle effects are based on fluctuating sex hormone levels. Fifteen subjects participated in four test sessions during their menstrual, mid-follicular, ovulatory, and midluteal phases. Brain activity was measured while nonpainful and painful stimuli were applied with a pressure algometer. Serum hormone levels confirmed that scans were performed at appropriate cycle phases in 14 subjects. No significant cycle phase differences were found for pain intensity or unpleasantness ratings of stimuli applied during fMRI scans. However, lower pressure pain thresholds were found for follicular compared to other phases. Pain-specific brain activation was found in several regions traditionally associated with pain processing, including the medial thalamus, anterior and mid-insula, mid-cingulate, primary and secondary somatosensory cortices, cerebellum, and frontal regions. The inferior parietal lobule, occipital gyrus, cerebellum and several frontal regions demonstrated interaction effects between stimulus level and cycle phase, indicating differential processing of pain-related responses across menstrual cycle phases. Correlational analyses indicated that cycle-related changes in pain sensitivity measures and brain activation were only partly explained by varying sex hormone levels. These results show that pain-related cerebral activation varies significantly across the menstrual cycle, even when perceived pain intensity and unpleasantness remain constant. The involved brain regions suggest that cognitive pain or more general bodily awareness systems are most susceptible to menstrual cycle effects. PMID:23528204

Cdk1 activity acts as a quantitative platform for coordinating cell cycle progression with periodic transcription

PubMed Central

Banyai, Gabor; Baïdi, Feriel; Coudreuse, Damien; Szilagyi, Zsolt

2016-01-01

Cell proliferation is regulated by cyclin-dependent kinases (Cdks) and requires the periodic expression of particular gene clusters in different cell cycle phases. However, the interplay between the networks that generate these transcriptional oscillations and the core cell cycle machinery remains largely unexplored. In this work, we use a synthetic regulable Cdk1 module to demonstrate that periodic expression is governed by quantitative changes in Cdk1 activity, with different clusters directly responding to specific activity levels. We further establish that cell cycle events neither participate in nor interfere with the Cdk1-driven transcriptional program, provided that cells are exposed to the appropriate Cdk1 activities. These findings contrast with current models that propose self-sustained and Cdk1-independent transcriptional oscillations. Our work therefore supports a model in which Cdk1 activity serves as a quantitative platform for coordinating cell cycle transitions with the expression of critical genes to bring about proper cell cycle progression. PMID:27045731

Wrist activity in a woman: daily, weekly, menstrual, lunar, annual cycles?

PubMed

Binkley, S

1992-09-01

Wrist activity was monitored continuously for one year in a woman who went about her normal life. The year of data were analyzed for changes and rhythms--daily, weekly, menstrual, lunar, annual. For each day, average motions/5 minutes, activity onset, activity offset, alpha (duration of activity), and acrophase were measured. Periodograms and average daily wave forms were calculated. Well-defined, entrained, daily rest-activity cycles were observed throughout the year with periods close to 24 hours. There was weekend delay (0.7 hours) in onset, weekend decrease in alpha (1.0 hours), and weekend advance of acrophase (0.4 hours). Motions/5 minutes decreased 9%, onsets were 0.3 hours later, and alphas were 0.4 hours shorter on menstrual cycle days 8 through 18 which should have encompassed the time of ovulation. Lunar phase had no effect. Annual changes in onset (1.1 hours), offset (1.2 hours), and acrophase (1.1 hours) were attributed to the 1-hour change between standard and daylight savings time.

Aluminum-Activated Malate Transporters Can Facilitate GABA Transport.

PubMed

Ramesh, Sunita A; Kamran, Muhammad; Sullivan, Wendy; Chirkova, Larissa; Okamoto, Mamoru; Degryse, Fien; McLaughlin, Michael; Gilliham, Matthew; Tyerman, Stephen D

2018-05-01

Plant aluminum-activated malate transporters (ALMTs) are currently classified as anion channels; they are also known to be regulated by diverse signals, leading to a range of physiological responses. Gamma-aminobutyric acid (GABA) regulation of anion flux through ALMT proteins requires a specific amino acid motif in ALMTs that shares similarity with a GABA binding site in mammalian GABA A receptors. Here, we explore why TaALMT1 activation leads to a negative correlation between malate efflux and endogenous GABA concentrations ([GABA] i ) in both wheat ( Triticum aestivum ) root tips and in heterologous expression systems. We show that TaALMT1 activation reduces [GABA] i because TaALMT1 facilitates GABA efflux but GABA does not complex Al 3+ TaALMT1 also leads to GABA transport into cells, demonstrated by a yeast complementation assay and via 14 C-GABA uptake into TaALMT1 -expressing Xenopus laevis oocytes; this was found to be a general feature of all ALMTs we examined. Mutation of the GABA motif (TaALMT1 F213C ) prevented both GABA influx and efflux, and resulted in no correlation between malate efflux and [GABA] i We conclude that ALMTs are likely to act as both GABA and anion transporters in planta. GABA and malate appear to interact with ALMTs in a complex manner to regulate each other's transport, suggestive of a role for ALMTs in communicating metabolic status. © 2018 American Society of Plant Biologists. All rights reserved.

Innovative leasing engineering as tool for synchronization of innovative, leasing and buying cycles

NASA Astrophysics Data System (ADS)

Yaskova, Natalia; Alekseeva, Tatyana

2017-10-01

This article suggests a new principle of cyclic synchronization of innovative, leasing and buying cycles in construction “innovative leasing engineering” which facilitates the accelerated transition of the national economy to the innovative way of development. Cyclical nature of economic phenomena is not only their immanent property, but also the subject of economic analysis. Modern format of decision making management requires analysis of the many cycles which fill any kind of activity. Accounting and reconciliation of construction, design, investment, buying, reproduction, leasing and other cycles is important for investment and construction sphere from the point of view of necessity for synchronization and position of determining the nature of trends in sectoral development.

Antiproliferative, DNA intercalation and redox cycling activities of dioxonaphtho[2,3-d]imidazolium analogs of YM155: A structure-activity relationship study.

PubMed

Ho, Si-Han Sherman; Sim, Mei-Yi; Yee, Wei-Loong Sherman; Yang, Tianming; Yuen, Shyi-Peng John; Go, Mei-Lin

2015-11-02

The anticancer agent YM155 is widely investigated as a specific survivin suppressant. More recently, YM155 was found to induce DNA damage and this has raised doubts as to whether survivin is its primary target. In an effort to assess the contribution of DNA damage to the anticancer activity of YM155, several analogs were prepared and evaluated for antiproliferative activity on malignant cells, participation in DNA intercalation and free radical generation by redox cycling. The intact positively charged scaffold was found to be essential for antiproliferative activity and intercalation but was less critical for redox cycling where the minimal requirement was a pared down bicyclic quinone. Side chain requirements at the N(1) and N(3) positions of the scaffold were more alike for redox cycling and intercalation than antiproliferative activity, underscoring yet again, the limited structural overlaps for these activities. Furthermore, antiproliferative activities were poorly correlated to DNA intercalation and redox cycling. Potent antiproliferative activity (IC50 9-23 nM), exceeding that of YM155, was found for a minimally substituted methyl analog AB7. Like YM155 and other dioxonaphthoimidazoliums, AB7 was a modest DNA intercalator but with weak redox cycling activity. Thus, the capacity of this scaffold to inflict direct DNA damage leading to cell death may not be significant and YM155 should not be routinely classified as a DNA damaging agent. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

An understanding of Japanese children's perceptions of fun, barriers, and facilitators of active free play.

PubMed

Lee, YingHua; Takenaka, Koji; Kanosue, Kazuyuki

2015-09-01

Physical activity contributes to children's physical and mental well-being. Research suggests that active free play helps to maintain and increase physical activity in children and also contributes to social and emotional well-being. To date, these studies have focused on Western countries. Thus, this study was conducted to gain insights into the factors of perceptions of fun, barriers, and facilitators affecting active free play from the perspective of Japanese children using focus group interviews. In Japan, 12 focus groups were conducted with 60 children aged 9-11 years. Children's perceptions of fun in active free play were categorized into socializing, achievement, emotions, and freedom. Additionally, active boys' groups were interested in free play and adventure play; girls' groups were interested in free play with less physical movement and challenges; inactive boys' groups were interested in relaxing and competitive play with bodily contact. However, children mentioned that busy schedules, weather, and health-related factors acted as main barriers. Lastly, children noted facilitators include setting schedules, having access to equipment and playgrounds, and holding special events. The findings provide insights into active free play-related factors for active and inactive Japanese children and also clarify the differences between Japanese and Western children. Such findings will contribute to designing interventions to increase active free play. © The Author(s) 2013.

Early Estimation of Solar Activity Cycle: Potential Capability and Limits

NASA Technical Reports Server (NTRS)

Kitiashvili, Irina N.; Collins, Nancy S.

2017-01-01

The variable solar magnetic activity known as the 11-year solar cycle has the longest history of solar observations. These cycles dramatically affect conditions in the heliosphere and the Earth's space environment. Our current understanding of the physical processes that make up global solar dynamics and the dynamo that generates the magnetic fields is sketchy, resulting in unrealistic descriptions in theoretical and numerical models of the solar cycles. The absence of long-term observations of solar interior dynamics and photospheric magnetic fields hinders development of accurate dynamo models and their calibration. In such situations, mathematical data assimilation methods provide an optimal approach for combining the available observational data and their uncertainties with theoretical models in order to estimate the state of the solar dynamo and predict future cycles. In this presentation, we will discuss the implementation and performance of an Ensemble Kalman Filter data assimilation method based on the Parker migratory dynamo model, complemented by the equation of magnetic helicity conservation and longterm sunspot data series. This approach has allowed us to reproduce the general properties of solar cycles and has already demonstrated a good predictive capability for the current cycle, 24. We will discuss further development of this approach, which includes a more sophisticated dynamo model, synoptic magnetogram data, and employs the DART Data Assimilation Research Testbed.

Identifying the Barriers and Facilitators to Participation in Physical Activity for Children with Down Syndrome

ERIC Educational Resources Information Center

Barr, M.; Shields, N.

2011-01-01

Background: Many children with Down syndrome do not undertake the recommended amount of daily physical activity. The aim of this study was to explore the barriers and facilitators to physical activity for this group. Methods: Eighteen in-depth interviews were conducted with 20 parents (16 mothers, 4 fathers) of children with Down syndrome aged…

A spontaneous change in the oxidation states of Pd/WO3 toward an active phase during catalytic cycles of CO oxidation

NASA Astrophysics Data System (ADS)

Jeon, Byungwook; Kim, Ansoon; Lee, Young-Ahn; Seo, Hyungtak; Kim, Yu Kwon

2017-11-01

CO oxidation over Pd/WO3 films prepared on a glass substrate has been examined at the substrate temperature of 150 - 250 °C and pressures less than 1 Torr with a stoichiometric mixture of CO and O2. Under the given reaction condition, the chemical states of the Pd/WO3 film gradually change into the most catalytically active form with the highest saturation reaction rate regardless of the initial oxidation states. The measured CO oxidation rate over the Pd/WO3 is strongly dependent on the chemical states of Pd and W. Either metallic Pd or fully oxidized PdO phase is not as catalytically active as the active form with mixed metallic Pd and thin PdO layers supported on WO3 with partially reduced W5+ state which is spontaneously obtained during the catalytic reaction cycles. Our results indicate that the facile oxygen transfer between Pd and WO3 layers not only facilitate the spontaneous changes into the active form, but also act as a promotional role in CO oxidation over the Pd layer.

Cell cycle effect on the activity of deoxynucleoside analogue metabolising enzymes

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

Fyrberg, Anna; Albertioni, Freidoun; Lotfi, Kourosh

Deoxynucleoside analogues (dNAs) are cytotoxic towards both replicating and indolent malignancies. The impact of fluctuations in the metabolism of dNAs in relation to cell cycle could have strong implications regarding the activity of dNAs. Deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK) are important enzymes for phosphorylation/activation of dNAs. These drugs can be dephosphorylated/deactivated by 5'-nucleotidases (5'-NTs) and elevated activities of 5'-NTs and decreased dCK and/or dGK activities represent resistance mechanisms towards dNAs. The activities of dCK, dGK, and three 5'-NTs were investigated in four human leukemic cell lines in relationship to cell cycle progression and cytotoxicity of dNAs. Synchronization ofmore » cell cultures to arrest in G0/G1 by serum-deprivation was performed followed by serum-supplementation for cell cycle progression. The activities of dCK and dGK increased up to 3-fold in CEM, HL60, and MOLT-4 cells as they started to proliferate, while the activity of cytosolic nucleotidase I was reduced in proliferating cells. CEM, HL60, and MOLT-4 cells were also more sensitive to cladribine, cytarabine, 9-{beta}-D-arabinofuranosylguanine and clofarabine than K562 cells which demonstrated lower levels and less alteration of these enzymes and were least susceptible to the cytotoxic effects of most dNAs. The results suggest that, in the cell lines studied, the proliferation process is associated with a general shift in the direction of activation of dNAs by inducing activities of dCK/dGK and reducing the activity of cN-I which is favourable for the cytotoxic effects of cladribine, cytarabine and, 9-{beta}-D-arabinofuranosylguanine. These results emphasize the importance of cellular proliferation and dNA metabolism by both phosphorylation and dephosphorylation for susceptibility to dNAs. It underscores the need to understand the mechanisms of action and resistance to dNAs in order to increase efficacy of dNAs treatment by new

Fasting launches CRTC to facilitate long-term memory formation in Drosophila.

PubMed

Hirano, Yukinori; Masuda, Tomoko; Naganos, Shintaro; Matsuno, Motomi; Ueno, Kohei; Miyashita, Tomoyuki; Horiuchi, Junjiro; Saitoe, Minoru

2013-01-25

Canonical aversive long-term memory (LTM) formation in Drosophila requires multiple spaced trainings, whereas appetitive LTM can be formed after a single training. Appetitive LTM requires fasting prior to training, which increases motivation for food intake. However, we found that fasting facilitated LTM formation in general; aversive LTM formation also occurred after single-cycle training when mild fasting was applied before training. Both fasting-dependent LTM (fLTM) and spaced training-dependent LTM (spLTM) required protein synthesis and cyclic adenosine monophosphate response element-binding protein (CREB) activity. However, spLTM required CREB activity in two neural populations--mushroom body and DAL neurons--whereas fLTM required CREB activity only in mushroom body neurons. fLTM uses the CREB coactivator CRTC, whereas spLTM uses the coactivator CBP. Thus, flies use distinct LTM machinery depending on their hunger state.

Institutional Context of Carbon Cycle Science Research in the U.S. and North America - A SOCCR perspective

NASA Astrophysics Data System (ADS)

Shrestha, G.; Cavallaro, N.; Ste-Marie, C.

2016-12-01

Carbon cycle science has been a research priority in the U.S. for decades. Interagency coordination interests and research needs in U.S. carbon cycle science led to the establishment of the U.S. Carbon Cycle Science Program, the North American Carbon Program (NACP), the Ocean Carbon and Biogeochemistry Program (OCB) and other intergovernmental collaboration platforms such as CarboNA, involving the U.S., Mexico and Canada. This presentation highlights some of these activities, and the historical context, the institutional frameworks and the operational mechanisms that have helped to facilitate and advance large scale collaborative research in carbon cycle in the U.S. and North America.

IMP3 Stabilization of WNT5B mRNA Facilitates TAZ Activation in Breast Cancer.

PubMed

Samanta, Sanjoy; Guru, Santosh; Elaimy, Ameer L; Amante, John J; Ou, Jianhong; Yu, Jun; Zhu, Lihua J; Mercurio, Arthur M

2018-05-29

Insulin-like growth factor-2 mRNA-binding protein 3 (IMP3) is an oncofetal protein associated with many aggressive cancers and implicated in the function of breast cancer stem cells (CSCs). The mechanisms involved, however, are poorly understood. We observed that IMP3 facilitates the activation of TAZ, a transcriptional co-activator of Hippo signaling that is necessary for the function of breast CSCs. The mechanism by which IMP3 activates TAZ involves both mRNA stability and transcriptional regulation. IMP3 stabilizes the mRNA of an alternative WNT ligand (WNT5B) indirectly by repressing miR145-5p, which targets WNT5B, resulting in TAZ activation by alternative WNT signaling. IMP3 also facilitates the transcription of SLUG, which is necessary for TAZ nuclear localization and activation, by a mechanism that is also mediated by WNT5B. These results demonstrate that TAZ can be regulated by an mRNA-binding protein and that this regulation involves the integration of Hippo and alternative WNT-signaling pathways. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Activation of Supraoptic Oxytocin Neurons by Secretin Facilitates Social Recognition.

PubMed

Takayanagi, Yuki; Yoshida, Masahide; Takashima, Akihide; Takanami, Keiko; Yoshida, Shoma; Nishimori, Katsuhiko; Nishijima, Ichiko; Sakamoto, Hirotaka; Yamagata, Takanori; Onaka, Tatsushi

2017-02-01

Social recognition underlies social behavior in animals, and patients with psychiatric disorders associated with social deficits show abnormalities in social recognition. Oxytocin is implicated in social behavior and has received attention as an effective treatment for sociobehavioral deficits. Secretin receptor-deficient mice show deficits in social behavior. The relationship between oxytocin and secretin concerning social behavior remains to be determined. Expression of c-Fos in oxytocin neurons and release of oxytocin from their dendrites after secretin application were investigated. Social recognition was examined after intracerebroventricular or local injection of secretin, oxytocin, or an oxytocin receptor antagonist in rats, oxytocin receptor-deficient mice, and secretin receptor-deficient mice. Electron and light microscopic immunohistochemical analysis was also performed to determine whether oxytocin neurons extend their dendrites into the medial amygdala. Supraoptic oxytocin neurons expressed the secretin receptor. Secretin activated supraoptic oxytocin neurons and facilitated oxytocin release from dendrites. Secretin increased acquisition of social recognition in an oxytocin receptor-dependent manner. Local application of secretin into the supraoptic nucleus facilitated social recognition, and this facilitation was blocked by an oxytocin receptor antagonist injected into, but not outside of, the medial amygdala. In the medial amygdala, dendrite-like thick oxytocin processes were found to extend from the supraoptic nucleus. Furthermore, oxytocin treatment restored deficits of social recognition in secretin receptor-deficient mice. The results of our study demonstrate that secretin-induced dendritic oxytocin release from supraoptic neurons enhances social recognition. The newly defined secretin-oxytocin system may lead to a possible treatment for social deficits. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights

Barriers, facilitators and attitudes influencing health promotion activities in general practice: an explorative pilot study

PubMed Central

2013-01-01

Background The number of chronically ill patients increases every year. This is partly due to an unhealthy lifestyle. However, the frequency and quality of (evidence-based) health promotion activities conducted by Dutch general practitioners (GPs) and practice nurses (PNs) are limited. The aim of this pilot study was to explore which lifestyle interventions Dutch GPs and PNs carry out in primary care, which barriers and facilitators can be identified and what main topics are with respect to attitudes towards health promoting activities. These topic areas will be identified for a future, larger scale study. Method This qualitative study consisted of 25 semi-structured interviews with sixteen GPs and nine PNs. ATLAS.ti was used to analyse the transcripts of the interviews. Results All GPs and PNs said they discuss lifestyle with their patients. Next to this, GPs and PNs counsel patients, and/or refer them to other disciplines. Only few said they refer patients to specific lifestyle programs or interventions in their own practice or in the neighbourhood. Several barriers and facilitators were identified. The main topics as barriers are: a lack of patients’ motivation to make lifestyle changes, insufficient reimbursement, a lack of proven effectiveness of interventions and a lack of overview of health promoting programs in their neighbourhood. The most cited facilitators are availability of a PN, collaboration with other disciplines and availability of interventions in their own practice. With respect to attitudes, six different types of GPs were identified reflecting the main topics that relate to attitudes, varying from ‘ignorer’ to ‘nurturer’. The topics relating to PNs attitudes towards health promotion activities, were almost unanimously positive. Conclusion GPs and PNs all say they discuss lifestyle issues with their patients, but the health promotion activities that are organized in their practice vary. Main topics that hinder or facilitate

The strategic use of lecture recordings to facilitate an active and self-directed learning approach.

PubMed

Topale, Luminica

2016-08-12

New learning technologies have the capacity to dramatically impact how students go about learning and to facilitate an active, self-directed learning approach. In U. S. medical education, students encounter a large volume of content, which must be mastered at an accelerated pace. The added pressure to excel on the USMLE Step 1 licensing exam and competition for residency placements, require that students adopt an informed approach to the use of learning technologies so as to enhance rather than to detract from the learning process. The primary aim of this study was to gain a better understanding of how students were using recorded lectures in their learning and how their study habits have been influenced by the technology. Survey research was undertaken using a convenience sample. Students were asked to voluntarily participate in an electronic survey comprised of 27 closed ended, multiple choice questions, and one open ended item. The survey was designed to explore students' perceptions of how recorded lectures affected their choices regarding class participation and impacted their learning and to gain an understanding of how recorded lectures facilitated a strategic, active learning process. Findings revealed that recorded lectures had little influence on students' choices to participate, and that the perceived benefits of integrating recorded lectures into study practices were related to their facilitation of and impact on efficient, active, and self-directed learning. This study was a useful investigation into how the availability of lecture capture technology influenced medical students' study behaviors and how students were making valuable use of the technology as an active learning tool.

Muscle sympathetic nerve responses to passive and active one-legged cycling: insights into the contributions of central command.

PubMed

Doherty, Connor J; Incognito, Anthony V; Notay, Karambir; Burns, Matthew J; Slysz, Joshua T; Seed, Jeremy D; Nardone, Massimo; Burr, Jamie F; Millar, Philip J

2018-01-01

The contribution of central command to the peripheral vasoconstrictor response during exercise has been investigated using primarily handgrip exercise. The purpose of the present study was to compare muscle sympathetic nerve activity (MSNA) responses during passive (involuntary) and active (voluntary) zero-load cycling to gain insights into the effects of central command on sympathetic outflow during dynamic exercise. Hemodynamic measurements and contralateral leg MSNA (microneurography) data were collected in 18 young healthy participants at rest and during 2 min of passive and active zero-load one-legged cycling. Arterial baroreflex control of MSNA burst occurrence and burst area were calculated separately in the time domain. Blood pressure and stroke volume increased during exercise ( P < 0.0001) but were not different between passive and active cycling ( P > 0.05). In contrast, heart rate, cardiac output, and total vascular conductance were greater during the first and second minute of active cycling ( P < 0.001). MSNA burst frequency and incidence decreased during passive and active cycling ( P < 0.0001), but no differences were detected between exercise modes ( P > 0.05). Reductions in total MSNA were attenuated during the first ( P < 0.0001) and second ( P = 0.0004) minute of active compared with passive cycling, in concert with increased MSNA burst amplitude ( P = 0.02 and P = 0.005, respectively). The sensitivity of arterial baroreflex control of MSNA burst occurrence was lower during active than passive cycling ( P = 0.01), while control of MSNA burst strength was unchanged ( P > 0.05). These results suggest that central feedforward mechanisms are involved primarily in modulating the strength, but not the occurrence, of a sympathetic burst during low-intensity dynamic leg exercise. NEW & NOTEWORTHY Muscle sympathetic nerve activity burst frequency decreased equally during passive and active cycling, but reductions in total muscle sympathetic nerve

Levels of Ycg1 Limit Condensin Function during the Cell Cycle

PubMed Central

Arsenault, Heather E.; Benanti, Jennifer A.

2016-01-01

During mitosis chromosomes are condensed to facilitate their segregation, through a process mediated by the condensin complex. Although several factors that promote maximal condensin activity during mitosis have been identified, the mechanisms that downregulate condensin activity during interphase are largely unknown. Here, we demonstrate that Ycg1, the Cap-G subunit of budding yeast condensin, is cell cycle-regulated with levels peaking in mitosis and decreasing as cells enter G1 phase. This cyclical expression pattern is established by a combination of cell cycle-regulated transcription and constitutive degradation. Interestingly, overexpression of YCG1 and mutations that stabilize Ycg1 each result in delayed cell-cycle entry and an overall proliferation defect. Overexpression of no other condensin subunit impacts the cell cycle, suggesting that Ycg1 is limiting for condensin complex formation. Consistent with this possibility, we find that levels of intact condensin complex are reduced in G1 phase compared to mitosis, and that increased Ycg1 expression leads to increases in both levels of condensin complex and binding to chromatin in G1. Together, these results demonstrate that Ycg1 levels limit condensin function in interphase cells, and suggest that the association of condensin with chromosomes must be reduced following mitosis to enable efficient progression through the cell cycle. PMID:27463097

Facilitators and barriers to physical activity following pulmonary rehabilitation in COPD: a systematic review of qualitative studies.

PubMed

Robinson, Hayley; Williams, Veronika; Curtis, Ffion; Bridle, Christopher; Jones, Arwel W

2018-06-04

Pulmonary rehabilitation has short-term benefits on dyspnea, exercise capacity and quality of life in COPD, but evidence suggests these do not always translate to increased daily physical activity on a patient level. This is attributed to a limited understanding of the determinants of physical activity maintenance following pulmonary rehabilitation. This systematic review of qualitative research was conducted to understand COPD patients' perceived facilitators and barriers to physical activity following pulmonary rehabilitation. Electronic databases of published data, non-published data, and trial registers were searched to identify qualitative studies (interviews, focus groups) reporting the facilitators and barriers to physical activity following pulmonary rehabilitation for people with COPD. Thematic synthesis of qualitative data was adopted involving line-by-line coding of the findings of the included studies, development of descriptive themes, and generation of analytical themes. Fourteen studies including 167 COPD patients met the inclusion criteria. Seven sub-themes were identified as influential to physical activity following pulmonary rehabilitation. These included: intentions, self-efficacy, feedback of capabilities and improvements, relationship with health care professionals, peer interaction, opportunities following pulmonary rehabilitation and routine. These encapsulated the facilitators and barriers to physical activity following pulmonary rehabilitation and were identified as sub-themes within the three analytical themes, which were beliefs, social support, and the environment. The findings highlight the challenge of promoting physical activity following pulmonary rehabilitation in COPD and provide complementary evidence to aid evaluations of interventions already attempted in this area, but also adds insight into future development of interventions targeting physical activity maintenance in COPD.

Cell cycle activation in p21 dependent pathway: An alternative mechanism of organophosphate induced dopaminergic neurodegeneration.

PubMed

Wani, Willayat Yousuf; Kandimalla, Ramesh J L; Sharma, Deep Raj; Kaushal, Alka; Ruban, Anand; Sunkaria, Aditya; Vallamkondu, Jayalakshmi; Chiarugi, Alberto; Reddy, P Hemachandra; Gill, Kiran Dip

2017-07-01

In the previous study, we demonstrated that dichlorvos induces oxidative stress in dopaminergic neuronal cells and subsequent caspase activation mediates apoptosis. In the present study, we evaluated the effect and mechanism of dichlorvos induced oxidative stress on cell cycle activation in NGF-differentiated PC12 cells. Dichlorvos exposure resulted in oxidative DNA damage along with activation of cell cycle machinery in differentiated PC12 cells. Dichlorvos exposed cells exhibited an increased expression of p53, cyclin-D1, pRb and decreased expression of p21suggesting a re-entry of differentiated cells into the cell cycle. Cell cycle analysis of dichlorvos exposed cells revealed a reduction of cells in the G 0 /G 1 phase of the cell cycle (25%), and a concomitant increase of cells in S phase (30%) and G2/M phase (43.3%) compared to control PC12 cells. Further, immunoblotting of cytochrome c, Bax, Bcl-2 and cleaved caspase-3 revealed that dichlorvos induces a caspase-dependent cell death in PC12 cells. These results suggest that Dichlorvos exposure has the potential to generate oxidative stress which evokes activation of cell cycle machinery leading to apoptotic cell death via cytochrome c release from mitochondria and subsequent caspase-3 activation in differentiated PC12 cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of menstrual cycle phase on corticolimbic brain activation by visual food cues.

PubMed

Frank, Tamar C; Kim, Ginah L; Krzemien, Alicja; Van Vugt, Dean A

2010-12-02

Food intake is decreased during the late follicular phase and increased in the luteal phase of the menstrual cycle. While a changing ovarian steroid milieu is believed to be responsible for this behavior, the specific mechanisms involved are poorly understood. Brain activity in response to visual food stimuli was compared during the estrogen dominant peri-ovulatory phase and the progesterone dominant luteal phase of the menstrual cycle. Twelve women underwent functional magnetic resonance imaging during the peri-ovulatory and luteal phases of the menstrual cycle in a counterbalanced fashion. Whole brain T2* images were collected while subjects viewed pictures of high calorie (HC) foods, low calorie (LC) foods, and control (C) pictures presented in a block design. Blood oxygen level dependent (BOLD) signal in the late follicular phase and luteal phase was determined for the contrasts HC-C, LC-C, HC-LC, and LC-HC. Both HC and LC stimuli activated numerous corticolimbic brain regions in the follicular phase, whereas only HC stimuli were effective in the luteal phase. Activation of the nucleus accumbens (NAc), amygdala, and hippocampus in response to the HC-C contrast and the hippocampus in response to the LC-C contrast was significantly increased in the late follicular phase compared to the luteal phase. Activation of the orbitofrontal cortex and mid cingulum in response to the HC-LC contrast was greater during the luteal phase. These results demonstrate for the first time that brain responses to visual food cues are influenced by menstrual cycle phase. We postulate that ovarian steroid modulation of the corticolimbic brain contributes to changes in ingestive behavior during the menstrual cycle. Copyright © 2010 Elsevier B.V. All rights reserved.

Seismic cycle feedbacks in a mid-crustal shear zone

NASA Astrophysics Data System (ADS)

Melosh, Benjamin L.; Rowe, Christie D.; Gerbi, Christopher; Smit, Louis; Macey, Paul

2018-07-01

Mid-crustal fault rheology is controlled by alternating brittle and plastic deformation mechanisms, which cause feedback cycles that influence earthquake behavior. Detailed mapping and microstructural observations in the Pofadder Shear Zone (Namibia and South Africa) reveal a lithologically heterogeneous shear zone core with quartz-rich mylonites and ultramylonites, plastically overprinted pseudotachylyte and active shear folds. We present evidence for a positive feedback cycle in which coseismic grain size reduction facilitates active shear folding by enhancing competency contrasts and promoting crystal plastic flow. Shear folding strengthens a portion of a shear zone by limb rotation, focusing deformation and promoting plastic flow or brittle slip in resulting areas of localized high stress. Using quartz paleopiezometry, we estimate strain and slip rates consistent with other studies of exhumed shear zones and modern plate boundary faults, helping establish the Pofadder Shear Zone as an ancient analogue to modern, continental-scale, strike-slip faults. This feedback cycle influences seismicity patterns at the scale of study (10s of meters) and possibly larger scales as well, and contributes to bulk strengthening of the brittle-plastic transition on modern plate boundary faults.

EEG activity during estral cycle in the rat.

PubMed

Corsi-Cabrera, M; Juárez, J; Ponce-de-León, M; Ramos, J; Velázquez, P N

1992-10-01

EEG activity was recorded from right and left parietal cortex in adult female rats daily during 6 days. Immediately after EEG recording vaginal smears were taken and were microscopically analyzed to determine the estral stage. Absolute and relative powers and interhemispheric correlation of EEG activity were calculated and compared between estral stages. Interhemispheric correlation was significantly lower during diestrous as compared to proestrous and estrous. Absolute and relative powers did not show significant differences between estral stages. Absolute powers of alpha1, alpha2, beta1 and beta2 bands were significantly higher at the right parietal cortex. Comparisons of the same EEG records with estral stages randomly grouped showed no significant differences for any of the EEG parameters. EEG activity is a sensitive tool to study functional changes related to the estral cycle.

Glutathione cycle activity and pyridine nucleotide levels in oxidant-induced injury of cells.

PubMed Central

Schraufstätter, I U; Hinshaw, D B; Hyslop, P A; Spragg, R G; Cochrane, C G

1985-01-01

Exposure of target cells to a bolus of H2O2 induced cell lysis after a latent period of several hours, which was prevented only when the H2O2 was removed within the first 30 min of injury by addition of catalase. This indicated that early metabolic events take place that are important in the fate of the cell exposed to oxidants. In this study, we described two early and independent events of H2O2-induced injury in P388D1 macrophagelike tumor cells: activation of the glutathione cycle and depletion of cellular NAD. Glutathione cycle and hexose monophosphate shunt (HMPS) were activated within seconds after the addition of H2O2. High HMPS activity maintained glutathione that was largely reduced. However, when HMPS activity was inhibited--by glucose depletion or by incubation at 4 degrees C--glutathione remained in the oxidized state. Total pyridine nucleotide levels were diminished when cells were exposed to H2O2, and the breakdown product, nicotinamide, was recovered in the extracellular medium. Intracellular NAD levels fell by 80% within 20 min of exposure of cells to H2O2. The loss of NADP(H) and stimulation of the HMPS could be prevented when the glutathione cycle was inhibited by either blocking glutathione synthesis with buthionine sulfoximine (BSO) or by inhibiting glutathione reductase with (1,3-bis) 2 chlorethyl-1-nitrosourea. The loss of NAD developed independently of glutathione cycle and HMPS activity, as it also occurred in BSO-treated cells. PMID:3840176

Mangiferin Facilitates Islet Regeneration and β-Cell Proliferation through Upregulation of Cell Cycle and β-Cell Regeneration Regulators

PubMed Central

Wang, Hai-Lian; Li, Chun-Yang; Zhang, Bin; Liu, Yuan-De; Lu, Bang-Min; Shi, Zheng; An, Na; Zhao, Liang-Kai; Zhang, Jing-Jing; Bao, Jin-Ku; Wang, Yi

2014-01-01

Mangiferin, a xanthonoid found in plants including mangoes and iris unguicularis, was suggested in previous studies to have anti-hyperglycemic function, though the underlying mechanisms are largely unknown. This study was designed to determine the therapeutic effect of mangiferin by the regeneration of β-cells in mice following 70% partial pancreatectomy (PPx), and to explore the mechanisms of mangiferin-induced β-cell proliferation. For this purpose, adult C57BL/6J mice after 7–14 days post-PPx, or a sham operation were subjected to mangiferin (30 and 90 mg/kg body weight) or control solvent injection. Mangiferin-treated mice exhibited an improved glycemia and glucose tolerance, increased serum insulin levels, enhanced β-cell hyperplasia, elevated β-cell proliferation and reduced β-cell apoptosis. Further dissection at the molecular level showed several key regulators of cell cycle, such as cyclin D1, D2 and cyclin-dependent kinase 4 (Cdk4) were significantly up-regulated in mangiferin-treated mice. In addition, critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (PDX-1), neurogenin 3 (Ngn3), glucose transporter 2 (GLUT-2), Forkhead box protein O1 (Foxo-1), and glucokinase (GCK), were found to be promoted by mangiferin at both the mRNA and protein expression level. Thus, mangiferin administration markedly facilitates β-cell proliferation and islet regeneration, likely by regulating essential genes in the cell cycle and the process of islet regeneration. These effects therefore suggest that mangiferin bears a therapeutic potential in preventing and/or treating the diabetes. PMID:24853132

Mangiferin facilitates islet regeneration and β-cell proliferation through upregulation of cell cycle and β-cell regeneration regulators.

PubMed

Wang, Hai-Lian; Li, Chun-Yang; Zhang, Bin; Liu, Yuan-De; Lu, Bang-Min; Shi, Zheng; An, Na; Zhao, Liang-Kai; Zhang, Jing-Jing; Bao, Jin-Ku; Wang, Yi

2014-05-20

Mangiferin, a xanthonoid found in plants including mangoes and iris unguicularis, was suggested in previous studies to have anti-hyperglycemic function, though the underlying mechanisms are largely unknown. This study was designed to determine the therapeutic effect of mangiferin by the regeneration of β-cells in mice following 70% partial pancreatectomy (PPx), and to explore the mechanisms of mangiferin-induced β-cell proliferation. For this purpose, adult C57BL/6J mice after 7-14 days post-PPx, or a sham operation were subjected to mangiferin (30 and 90 mg/kg body weight) or control solvent injection. Mangiferin-treated mice exhibited an improved glycemia and glucose tolerance, increased serum insulin levels, enhanced β-cell hyperplasia, elevated β-cell proliferation and reduced β-cell apoptosis. Further dissection at the molecular level showed several key regulators of cell cycle, such as cyclin D1, D2 and cyclin-dependent kinase 4 (Cdk4) were significantly up-regulated in mangiferin-treated mice. In addition, critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (PDX-1), neurogenin 3 (Ngn3), glucose transporter 2 (GLUT-2), Forkhead box protein O1 (Foxo-1), and glucokinase (GCK), were found to be promoted by mangiferin at both the mRNA and protein expression level. Thus, mangiferin administration markedly facilitates β-cell proliferation and islet regeneration, likely by regulating essential genes in the cell cycle and the process of islet regeneration. These effects therefore suggest that mangiferin bears a therapeutic potential in preventing and/or treating the diabetes.

Exploring Perceptions of Barriers, Facilitators, and Motivators to Physical Activity Among Female Bariatric Patients: Implications for Physical Activity Programming.

PubMed

Dikareva, A; Harvey, W J; Cicchillitti, M A; Bartlett, S J; Andersen, R E

2016-09-01

To explore barriers, facilitators, and motivators to adopting and maintaining regular physical activity among women with obesity who have undergone bariatric surgery. Individual interviews with women 3 to 24 months post-bariatric surgery. Participants were recruited from a bariatric clinic in Montreal, Canada. Twelve women were recruited (mean age = 47 ± 9 years) using poster advertisements and word of mouth. Participants were on average 15 months postsurgery. Each woman was interviewed once using a semistructured interview protocol. Recruitment was conducted until data saturation (i.e., no new information emerged). The interviews were transcribed, coded, and analyzed using inductive thematic analysis. Three interrelated themes emerged: the physical body, appraisal of the physical and social self, and the exercise environment. Barriers included weight-restricted mobility, side effects of surgery, body dissatisfaction, compromised psychological health, competing responsibilities, a lack of exercise self-efficacy and social support, reduced access to accommodating facilities, lack of exercise knowledge, and northern climate. Participants reported postsurgical weight loss, weight and health maintenance, enjoyment, body image, and supportive active relationships, as well as access to accommodating facilities and exercise knowledge, as facilitators and motivators. Suggested physical activity programming strategies for health care professionals working with this unique population are discussed. Physical activity and health promotion initiatives can also benefit from a cultural paradigm shift away from weight-based representations of health. © 2016 by American Journal of Health Promotion, Inc.

Comparing Two Forms of Concept Map Critique Activities to Facilitate Knowledge Integration Processes in Evolution Education

ERIC Educational Resources Information Center

Schwendimann, Beat A.; Linn, Marcia C.

2016-01-01

Concept map activities often lack a subsequent revision step that facilitates knowledge integration. This study compares two collaborative critique activities using a Knowledge Integration Map (KIM), a form of concept map. Four classes of high school biology students (n?=?81) using an online inquiry-based learning unit on evolution were assigned…

Effectiveness and Student Perceptions of an Active Learning Activity Using a Headline News Story to Enhance In-Class Learning of Cell Cycle Regulation

ERIC Educational Resources Information Center

Dirks-Naylor, Amie J.

2016-01-01

An active learning activity was used to engage students and enhance in-class learning of cell cycle regulation in a PharmD level integrated biological sciences course. The aim of the present study was to determine the effectiveness and perception of the in-class activity. After completion of a lecture on the topic of cell cycle regulation,…

SOLAR CYCLE 25: ANOTHER MODERATE CYCLE?

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

Cameron, R. H.; Schüssler, M.; Jiang, J., E-mail: cameron@mps.mpg.de

2016-06-01

Surface flux transport simulations for the descending phase of Cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipole moment around 2020 (2.5 ± 1.1 G) is comparable to that observed at the end of Cycle 23 (about 2 G). The empirical correlation between the dipole moment during solar minimum and the strength of the subsequent cycle thus suggests that Cycle 25 will be of moderate amplitude, not muchmore » higher than that of the current cycle. However, the intrinsic uncertainty of such predictions resulting from the random scatter of the source properties is considerable and fundamentally limits the reliability with which such predictions can be made before activity minimum is reached.« less

Status of Cycle 23 Forecasts

NASA Technical Reports Server (NTRS)

Hathaway, D. H.

2000-01-01

A number of techniques for predicting solar activity on a solar cycle time scale are identified, described, and tested with historical data. Some techniques, e.g,, regression and curve-fitting, work well as solar activity approaches maximum and provide a month- by-month description of future activity, while others, e.g., geomagnetic precursors, work well near solar minimum but provide an estimate only of the amplitude of the cycle. A synthesis of different techniques is shown to provide a more accurate and useful forecast of solar cycle activity levels. A combination of two uncorrelated geomagnetic precursor techniques provides the most accurate prediction for the amplitude of a solar activity cycle at a time well before activity minimum. This precursor method gave a smoothed sunspot number maximum of 154+21 for cycle 23. A mathematical function dependent upon the time of cycle initiation and the cycle amplitude then describes the level of solar activity for the complete cycle. As the time of cycle maximum approaches a better estimate of the cycle activity is obtained by including the fit between recent activity levels and this function. This Combined Solar Cycle Activity Forecast now gives a smoothed sunspot maximum of 140+20 for cycle 23. The success of the geomagnetic precursors in predicting future solar activity suggests that solar magnetic phenomena at latitudes above the sunspot activity belts are linked to solar activity, which occurs many years later in the lower latitudes.

Unexpected Voltage Fade in LMR-NMC Oxides Cycled below the "Activation" Plateau

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

Li, Y.; Bareno, J.; Bettge, M.

A common feature of lithium-excess layered oxides, nominally of composition xLi(2)MnO(3)center dot(1-x)LiMO2 (M = transition metal) is a high-voltage plateau (similar to 4.5 V vs. Li/Li+) in their capacity-voltage profile during the first delithiation cycle. This plateau is believed to result from activation of the Li2MnO3 component, which makes additional lithium available for electrochemical cycling. However, oxides cycled beyond this activation plateau are known to display voltage fade which is a continuous reduction in their equilibrium potential. In this article we show that these oxides display gradual voltage fade even on electrochemical cycling in voltage ranges well below the activationmore » plateau. The average fade is similar to 0.08 mV-cycle(-1) for Li(1.2)Ni(0.1)5Mn(0.5)5Co(0.1)O(2) vs. Li cells after 20 cycles in the 2-4.1 V range at 55 degrees C; a similar to 54 mV voltage hysteresis, expressed as the difference in average cell voltage between charge and discharge cycles, is also observed. The voltage fade results from a gradual accumulation of local spinel environments in the crystal structure. Some of these spinel sites result from lithium deficiencies during oxide synthesis and are likely to be at the particle surfaces; other sites result from the migration of transition metal atoms in the partially-delithiated LiMO2 component into the lithium planes during electrochemical cycling. The observed rate of voltage fade depends on a combination of factors that includes the phase equilibrium between the layered and spinel components and the kinetics of transition metal migration. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.« less

Facilitation handlings induce increase in electromyographic activity of muscles involved in head control of cerebral palsy children.

PubMed

Simon, Anelise de Saldanha; do Pinho, Alexandre Severo; Grazziotin Dos Santos, Camila; Pagnussat, Aline de Souza

2014-10-01

This study aimed to investigate the electromyographic (EMG) activation of the main cervical muscles involved in the head control during two postures widely used for the facilitation of head control in children with Cerebral Palsy (CP). A crossover trial involving 31 children with clinical diagnosis of CP and spastic quadriplegia was conducted. Electromyography was used to measure muscular activity in randomized postures. Three positions were at rest: (a) lateral decubitus, (b) ventral decubitus on the floor and (c) ventral decubitus on the wedge. Handlings for facilitating the head control were performed using the hip joint as key point of control in two postures: (a) lateral decubitus and (b) ventral decubitus on wedge. All children underwent standardized handlings, performed by the same researcher with experience in the neurodevelopmental treatment. EMG signal was recorded from muscles involved in the head control (paraspinal and sternocleidomastoid muscles) in sagittal, frontal and transverse planes, at the fourth cervical vertebra (C4), tenth thoracic vertebra (T10) and sternocleidomastoid muscle (SCM) levels. The results showed a significant increase in muscle activation when handling was performed in the lateral decubitus at C4 (P<0.001), T10 (P<0.001) and SCM (P=0.02) levels. A significant higher muscle activation was observed when handling was performed in lateral decubitus when compared to ventral decubitus at C4 level (P<0.001). Handling in ventral decubitus also induced an increase in EMG activation at T10 (P=0.018) and SCM (P=0.004) levels but not at C4 level (P=0.38). In conclusion, handlings performed in both positions may induce the facilitation of head control, as evaluated by the activity of cervical and upper trunk muscles. Handling performed in lateral decubitus may induce a slightly better facilitation of head control. These findings contribute to evidence-based physiotherapy practice for the rehabilitation of severely spastic quadriplegic CP

THE WATER-WATER CYCLE IN CHLOROPLASTS: Scavenging of Active Oxygens and Dissipation of Excess Photons.

PubMed

Asada, Kozi

1999-06-01

Photoreduction of dioxygen in photosystem I (PSI) of chloroplasts generates superoxide radicals as the primary product. In intact chloroplasts, the superoxide and the hydrogen peroxide produced via the disproportionation of superoxide are so rapidly scavenged at the site of their generation that the active oxygens do not inactivate the PSI complex, the stromal enzymes, or the scavenging system itself. The overall reaction for scavenging of active oxygens is the photoreduction of dioxygen to water via superoxide and hydrogen peroxide in PSI by the electrons derived from water in PSII, and the water-water cycle is proposed for these sequences. An overview is given of the molecular mechanism of the water-water cycle and microcompartmentalization of the enzymes participating in it. Whenever the water-water cycle operates properly for scavenging of active oxygens in chloroplasts, it also effectively dissipates excess excitation energy under environmental stress. The dual functions of the water-water cycle for protection from photoinihibition are discussed.

Bicycle Trains, Cycling, and Physical Activity: A Pilot Cluster RCT.

PubMed

Mendoza, Jason A; Haaland, Wren; Jacobs, Maya; Abbey-Lambertz, Mark; Miller, Josh; Salls, Deb; Todd, Winifred; Madding, Rachel; Ellis, Katherine; Kerr, Jacqueline

2017-10-01

Increasing children's cycling to school and physical activity are national health goals. The objective was to conduct an RCT of a bicycle train program to assess impact on students' school travel mode and moderate-to-vigorous physical activity (MVPA). Pilot cluster RCT with randomization at the school level and N=54 participants. Fourth-fifth graders from four public schools serving low-income families in Seattle, WA in 2014 with analyses in 2015-2016. All participants were provided and fitted with bicycles, safety equipment (helmets, locks, and lights), and a 2- to 3-hour bicycle safety course. The intervention was a bicycle train offered daily (i.e., students volunteered to cycle with study staff to and from school). Time 1 assessments occurred prior to randomization. Time 2 assessments occurred after 3-5 weeks of the intervention (i.e., during Weeks 4-6 of the intervention period). The primary outcome was the percentage of daily commutes to school by cycling measured by validated survey. MVPA, measured by accelerometry and GPS units and processed by machine learning algorithms, was a secondary outcome. For two separate adjusted repeated measures linear mixed effects models in which students (N=54) were nested within schools (N=4), intervention participants had: (1) an absolute increase in mean percentage of daily commutes by cycling of 44.9%, (95% CI=26.8, 63.0) and (2) an increase in mean MVPA of 21.6 minutes/day, (95% CI=8.7, 34.6) from Time 1 to Time 2 compared with controls. A pilot bicycle train intervention increased cycling to school and daily MVPA in the short term among diverse, inner-city elementary school students. The bicycle train intervention appears promising and warrants further experimental trials among large, diverse samples with longer follow-up. This study is registered at www.clinicaltrials.gov NCT02006186. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Recovery of functionally-active protein from inclusion bodies using a thermal-cycling method.

PubMed

Sadavarte, Rahul; Filipe, Carlos D M; Ghosh, Raja

2017-01-01

Heterologous overexpression of genes in Escherichia coli has made it possible to obtain high titers of recombinant proteins. However, this can result in the formation of aggregated protein particles known as 'inclusion bodies'. Protein sequestered as inclusion body is inactive and needs to be converted back to its functional form by refolding using appropriate techniques. In the current study inclusion bodies of the enzyme aminoglycoside nucleotidyl transferase (or ANT(2″)-Ia) were first solubilized in urea and subsequently subjected to thermal cycling under controlled conditions as part of the refolding strategy. Thermal cycling led to disaggregation of the individual protein chains and simultaneously refolding the released protein molecules to their native state. The optimum condition was identified as 10-80°C thermal cycling at 3°C s -1 for 2 h. Enzyme activity measurements showed that thermal cycling under optimized conditions resulted in 257% activity recovery when compared with nonrefolded protein. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:133-139, 2017. © 2016 American Institute of Chemical Engineers.

Repeated pulses of serotonin required for long-term facilitation activate mitogen-activated protein kinase in sensory neurons of Aplysia

PubMed Central

Michael, Dan; Martin, Kelsey C.; Seger, Rony; Ning, Ming-Ming; Baston, Rene; Kandel, Eric R.

1998-01-01

Long-term facilitation of the connections between the sensory and motor neurons of the gill-withdrawal reflex in Aplysia requires five repeated pulses of serotonin (5-HT). The repeated pulses of 5-HT initiate a cascade of gene activation that leads ultimately to the growth of new synaptic connections. Several genes in this process have been identified, including the transcriptional regulators apCREB-1, apCREB-2, apC/EBP, and the cell adhesion molecule apCAM, which is thought to be involved in the formation of new synaptic connections. Here we report that the transcriptional regulators apCREB-2 and apC/EBP, as well as a peptide derived from the cytoplasmic domain of apCAM, are phosphorylated in vitro by Aplysia mitogen-activated protein kinase (apMAPK). We have cloned the cDNA encoding apMAPK and show that apMAPK activity is increased in sensory neurons treated with repeated pulses of 5-HT and by the cAMP pathway. These results suggest that apMAPK may participate with cAMP-dependent protein kinase during long-term facilitation in sensory cells by modifying some of the key elements involved in the consolidation of short- to long-lasting changes in synaptic strength. PMID:9465108

Barriers, motivators, and facilitators of physical activity in dementia patients: A systematic review.

PubMed

van Alphen, Helena J M; Hortobágyi, Tibor; van Heuvelen, Marieke J G

2016-01-01

Physical activity (PA) has the potential to slow the progression of dementia patients' cognitive and physical decline. A better understanding of the factors that facilitate or hamper dementia patients' PA participation will increase the success rate of implementing PA in dementia patients' daily care. We systematically screened the barriers, motivators, and facilitators of PA participation in dementia patients, complementing previous analyses of quantitative correlates of PA in community-dwelling dementia patients. Systematic searches yielded 78 potential studies of which seven met the eligibility criteria including 39 dementia patients and 36 caregivers (33 spouses and three daughters). We identified 35 barriers, 26 motivators, and 21 facilitators related to PA. We reduced these factors to six themes within the social-ecological model. Prominent barriers to PA were physical and mental limitations and difficulties with guidance and organization of PA by caregivers. Motivators included the motivation to maintain physical and mental health and participate in preferred PA options. Facilitators included strategies to avoid health problems, providing support and guidance for PA, and access to convenient and personalized PA options. The emerging picture suggests that dementia patients' PA participation will increase if service providers become familiar with the health benefits of PA, the characteristics of PA programs, methods of delivery, and the concepts of how such programs can be personalized to and synchronized with patients' individual needs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Observations of hysteresis in solar cycle variations among seven solar activity indicators

NASA Technical Reports Server (NTRS)

Bachmann, Kurt T.; White, Oran R.

1994-01-01

We show that smoothed time series of 7 indices of solar activity exhibit significant solar cycle dependent differences in their relative variations during the past 20 years. In some cases these observed hysteresis patterns start to repeat over more than one solar cycle, giving evidence that this is a normal feature of solar variability. Among the indices we study, we find that the hysteresis effects are approximately simple phase shifts, and we quantify these phase shifts in terms of lag times behind the leading index, the International Sunspot Number. Our measured lag times range from less than one month to greater than four months and can be much larger than lag times estimated from short-term variations of these same activity indices during the emergence and decay of major active regions. We argue that hysteresis represents a real delay in the onset and decline of solar activity and is an important clue in the search for physical processes responsible for changing solar emission at various wavelengths.

The relationship between facilitators' questions and the level of reflection in postsimulation debriefing.

PubMed

Husebø, Sissel Eikeland; Dieckmann, Peter; Rystedt, Hans; Søreide, Eldar; Friberg, Febe

2013-06-01

Simulation-based education is a learner-active method that may enhance teamwork skills such as leadership and communication. The importance of postsimulation debriefing to promote reflection is well accepted, but many questions concerning whether and how faculty promote reflection remain largely unanswered in the research literature. The aim of this study was therefore to explore the depth of reflection expressed in questions by facilitators and responses from nursing students during postsimulation debriefings. Eighty-one nursing students and 4 facilitators participated. The data were collected in February and March 2008, the analysis being conducted on 24 video-recorded debriefings from simulated resuscitation teamwork involving nursing students only. Using Gibbs' reflective cycle, we graded the facilitators' questions and nursing students' responses into stages of reflection and then correlated these. Facilitators asked most evaluative and fewest emotional questions, whereas nursing students answered most evaluative and analytic responses and fewest emotional responses. The greatest difference between facilitators and nursing students was in the analytic stage. Only 23 (20%) of 117 questions asked by the facilitators were analytic, whereas 45 (35%) of 130 students' responses were rated as analytic. Nevertheless, the facilitators' descriptive questions also elicited student responses in other stages such as evaluative and analytic responses. We found that postsimulation debriefings provide students with the opportunity to reflect on their simulation experience. Still, if the debriefing is going to pave the way for student reflection, it is necessary to work further on structuring the debriefing to facilitate deeper reflection. Furthermore, it is important that facilitators consider what kind of questions they ask to promote reflection. We think future research on debriefing should focus on developing an analytical framework for grading reflective questions. Such

The immediate effect of neuromuscular joint facilitation on the rotation of the tibia during walking.

PubMed

Li, Desheng; Huang, Qiuchen; Huo, Ming; Hiiragi, Yukinobu; Maruyama, Hitoshi

2017-01-01

[Purpose] The aim of this study was to investigate the change in tibial rotation during walking among young adults after neuromuscular joint facilitation therapy. [Subjects and Methods] The subjects were twelve healthy young people (6 males, 6 females). A neuromuscular joint facilitation intervention and nonintervention were performed. The interventions were performed one after the other, separated by a 1-week interval. The order of the interventions was completely randomized. The rotation of the tibia during walking was evaluated before and after treatment. [Results] The neuromuscular joint facilitation group demonstrated increased lateral rotation of the tibia in the overall gait cycle and stance phase, and decreased medial rotation of the tibia in the overall gait cycle, stance phase, and swing phase after the neuromuscular joint facilitation intervention. In the control group, there were no significant differences. [Conclusion] These results suggest neuromuscular joint facilitation intervention has an immediate effect on the rotational function of the knee.

Anatomically remote muscle contraction facilitates patellar tendon reflex reinforcement while mental activity does not: a within-participants experimental trial.

PubMed

Passmore, Steven R; Bruno, Paul A

2012-09-07

The Jendrassik maneuver (JM) is a remote facilitation muscular contraction shown to affect amplitude and temporal components of the human stretch reflex. Conflicting theoretical models exist regarding the neurological mechanism related to its ability to reinforce reflex parameters. One mechanism involves the gamma motoneurons of the fusimotor system, which are subject to both physical and mental activity. A second mechanism describes reduced alpha motoneuron presynaptic inhibition, which is not subject to mental activity. In the current study, we determined if mental activity could be used to create a reflex facilitation comparable to a remote muscle contraction. Using a within-participants design, we investigated the relative effect of the JM and a successfully employed mental task (Stroop task) on the amplitude and temporal components of the patellar tendon reflex. We found that the addition of mental activity had no influence on the patellar tendon reflex parameters measured, while the JM provided facilitation (increased reflex amplitude, decreased total reflex time). The findings from this study support the view that the mechanism for the JM is a reduction in presynaptic inhibition of alpha motoneurons as it is influenced by physical and not mental activity.

TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

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

Ding, Li; College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158; Huang, Yong

2014-03-07

Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressedmore » cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.« less

A Walk (or Cycle) to the Park: Active Transit to Neighborhood Amenities, the CARDIA Study

PubMed Central

Boone-Heinonen, Janne; Jacobs, David R.; Sidney, Stephen; Sternfeld, Barbara; Lewis, Cora E.; Gordon-Larsen, Penny

2009-01-01

Background Building on known associations between active commuting and reduced cardiovascular disease (CVD) risk, this study examines active transit to neighborhood amenities and differences between walking versus cycling for transportation. Method Year 20 data from the Coronary Artery Risk Development in Young Adults (CARDIA) study (3549 black and white adults aged 38–50 years in 2005–06) were analyzed in 2008–2009. Sociodemographic correlates of transportation mode (car-only, walk-only, any cycling, other) to neighborhood amenities were examined in multivariable multinomial logistic models. Gender-stratified, multivariable linear or multinomial regression models compared CVD risk factors across transit modes. Results Active transit was most common to parks and public transit stops; walking was more common than cycling. Among those who used each amenity, active transit (walk-only and any cycling versus car-only transit) was more common in men and those with no live-in partner and less than full-time employment [significant OR's (95% CI) ranging from 1.56 (1.08, 2.27) to 4.52 (1.70, 12.14)], and less common in those with children. Active transit to any neighborhood amenity was associated with more favorable BMI, waist circumference, and fitness [largest coefficient (95% CI) −1.68 (−2.81, −0.55) for BMI, −3.41 (−5.71, −1.11) for waist circumference (cm), and 36.65 (17.99, 55.31) for treadmill test duration (sec)]. Only cycling was associated with lower lifetime CVD risk classification. Conclusion Active transit to neighborhood amenities was related to sociodemographics and CVD risk factors. Variation in health-related benefits by active transit mode, if validated in prospective studies, may have implications for transportation planning and research. PMID:19765499

Parental perceptions of facilitators and barriers to physical activity for children with intellectual disabilities: A mixed methods systematic review.

PubMed

McGarty, Arlene M; Melville, Craig A

2018-02-01

There is a need increase our understanding of what factors affect physical activity participation in children with intellectual disabilities (ID) and develop effective methods to overcome barriers and increase activity levels. This study aimed to systematically review parental perceptions of facilitators and barriers to physical activity for children with ID. A systematic search of Embase, Medline, ERIC, Web of Science, and PsycINFO was conducted (up to and including August, 2017) to identify relevant papers. A meta-ethnography approach was used to synthesise qualitative and quantitative results through the generation of third-order themes and a theoretical model. Ten studies were included, which ranged from weak to strong quality. Seventy-one second-order themes and 12 quantitative results were extracted. Five third-order themes were developed: family, child factors, inclusive programmes and facilities, social motivation, and child's experiences of physical activity. It is theorised that these factors can be facilitators or barriers to physical activity, depending on the information and education of relevant others, e.g. parents and coaches. Parents have an important role in supporting activity in children with ID. Increasing the information and education given to relevant others could be an important method of turning barriers into facilitators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Will Solar Cycles 25 and 26 Be Weaker than Cycle 24?

NASA Astrophysics Data System (ADS)

Javaraiah, J.

2017-11-01

The study of variations in solar activity is important for understanding the underlying mechanism of solar activity and for predicting the level of activity in view of the activity impact on space weather and global climate. Here we have used the amplitudes (the peak values of the 13-month smoothed international sunspot number) of Solar Cycles 1 - 24 to predict the relative amplitudes of the solar cycles during the rising phase of the upcoming Gleissberg cycle. We fitted a cosine function to the amplitudes and times of the solar cycles after subtracting a linear fit of the amplitudes. The best cosine fit shows overall properties (periods, maxima, minima, etc.) of Gleissberg cycles, but with large uncertainties. We obtain a pattern of the rising phase of the upcoming Gleissberg cycle, but there is considerable ambiguity. Using the epochs of violations of the Gnevyshev-Ohl rule (G-O rule) and the `tentative inverse G-O rule' of solar cycles during the period 1610 - 2015, and also using the epochs where the orbital angular momentum of the Sun is steeply decreased during the period 1600 - 2099, we infer that Solar Cycle 25 will be weaker than Cycle 24. Cycles 25 and 26 will have almost same strength, and their epochs are at the minimum between the current and upcoming Gleissberg cycles. In addition, Cycle 27 is expected to be stronger than Cycle 26 and weaker than Cycle 28, and Cycle 29 is expected to be stronger than both Cycles 28 and 30. The maximum of Cycle 29 is expected to represent the next Gleissberg maximum. Our analysis also suggests a much lower value (30 - 40) for the maximum amplitude of the upcoming Cycle 25.

Modulation of corticospinal input to the legs by arm and leg cycling in people with incomplete spinal cord injury.

PubMed

Zhou, R; Alvarado, L; Kim, S; Chong, S L; Mushahwar, V K

2017-10-01

The spinal cervico-lumbar interaction during rhythmic movements in humans has recently been studied; however, the role of arm movements in modulating the corticospinal drive to the legs is not well understood. The goals of this study were to investigate the effect of active rhythmic arm movements on the corticospinal drive to the legs ( study 1 ) and assess the effect of simultaneous arm and leg training on the corticospinal pathway after incomplete spinal cord injury (iSCI) ( study 2). In study 1 , neurologically intact (NI) participants or participants with iSCI performed combinations of stationary and rhythmic cycling of the arms and legs while motor evoked potentials (MEPs) were recorded from the vastus lateralis (VL) muscle. In the NI group, arm cycling alone could facilitate the VL MEP amplitude, suggesting that dynamic arm movements strongly modulate the corticospinal pathway to the legs. No significant difference in VL MEP between conditions was found in participants with iSCI. In study 2 , participants with iSCI underwent 12 wk of electrical stimulation-assisted cycling training: one group performed simultaneous arm and leg (A&L) cycling and the other legs-only cycling. MEPs in the tibialis anterior (TA) muscle were compared before and after training. After training, only the A&L group had a significantly larger TA MEP, suggesting increased excitability in the corticospinal pathway. The findings demonstrate the importance of arm movements in modulating the corticospinal drive to the legs and suggest that active engagement of the arms in lower limb rehabilitation may produce better neural regulation and restoration of function. NEW & NOTEWORTHY This study aimed to demonstrate the importance of arm movements in modulating the corticospinal drive to the legs. It provides direct evidence in humans that active movement of the arms could facilitate corticospinal transmission to the legs and, for the first time, shows that facilitation is absent after spinal cord

Goal conflict, goal facilitation, and health professionals' provision of physical activity advice in primary care: an exploratory prospective study.

PubMed

Presseau, Justin; Francis, Jill J; Campbell, Neil C; Sniehotta, Falko F

2011-07-15

The theory of planned behaviour has well-evidenced utility in predicting health professional behaviour, but focuses on a single behaviour isolated from the numerous potentially conflicting and facilitating goal-directed behaviours performed alongside. Goal conflict and goal facilitation may influence whether health professionals engage in guideline-recommended behaviours, and may supplement the predictive power of the theory of planned behaviour. We hypothesised that goal facilitation and goal conflict contribute to predicting primary care health professionals' provision of physical activity advice to patients with hypertension, over and above predictors of behaviour from the theory of planned behaviour. Using a prospective predictive design, at baseline we invited a random sample of 606 primary care health professionals from all primary care practices in NHS Grampian and NHS Tayside (Scotland) to complete postal questionnaires. Goal facilitation and goal conflict were measured alongside theory of planned behaviour constructs at baseline. At follow-up six months later, participants self-reported the number of patients, out of those seen in the preceding two weeks, to whom they provided physical activity advice. Forty-four primary care physicians and nurses completed measures at both time points (7.3% response rate). Goal facilitation and goal conflict improved the prediction of behaviour, accounting for substantial additional variance (5.8% and 8.4%, respectively) in behaviour over and above intention and perceived behavioural control. Health professionals' provision of physical activity advice in primary care can be predicted by perceptions about how their conflicting and facilitating goal-directed behaviours help and hinder giving advice, over and above theory of planned behaviour constructs. Incorporating features of multiple goal pursuit into the theory of planned behaviour may help to better understand health professional behaviour.

Dynamo-based scheme for forecasting the magnitude of solar activity cycles

NASA Technical Reports Server (NTRS)

Layden, A. C.; Fox, P. A.; Howard, J. M.; Sarajedini, A.; Schatten, K. H.

1991-01-01

This paper presents a general framework for forecasting the smoothed maximum level of solar activity in a given cycle, based on a simple understanding of the solar dynamo. This type of forecasting requires knowledge of the sun's polar magnetic field strength at the preceding activity minimum. Because direct measurements of this quantity are difficult to obtain, the quality of a number of proxy indicators already used by other authors is evaluated, which are physically related to the sun's polar field. These indicators are subjected to a rigorous statistical analysis, and the analysis technique for each indicator is specified in detail in order to simplify and systematize reanalysis for future use. It is found that several of these proxies are in fact poorly correlated or uncorrelated with solar activity, and thus are of little value for predicting activity maxima. Also presented is a scheme in which the predictions of the individual proxies are combined via an appropriately weighted mean to produce a compound prediction. The scheme is then applied to the current cycle 22, and a maximum smoothed international sunspot number of 171 + or - 26 is estimated.

Female Fear: Influence of Estrus Cycle on Behavioral Response and Neuronal Activation

PubMed Central

Chen, Wei; Shields, Jessica; Huang, Wei; King, Jean A

2009-01-01

Our observation that male rats innate fear response differed with hormonal status, as well as the higher prevalence of fear and anxiety disorders in human females led to the current investigation of the impact of phases of the estrous cycle on innate fear responding. Female rats in different phases of the cycle were exposed to an innate fear-inducing stimulus (2,5-dihydro- 2,4,5-trimethylthiazoline, TMT odor) and monitored for changes in behavior and brain activation. Behavioral data showed freezing responses to TMT were significantly enhanced during estrus as compared to other phases of the cycle. This data was supported by significant increases in pixel intensity in cortical and sub-cortical regions in estrus compared to proestrus and diestrus. Imaging results demonstrated significant increases in brain activation in the somatosensory and insular cortices when comparing estrus to diestrus. There were significant increases in neural activity in the BNST and septum in estrus as compared to proestrus. Additionally, the hippocampus, hypothalamus, olfactory system, and cingulate cortex show significant increases in the estrus phase when compared to both diestrus and proestrus. Taken together, these results suggest that the female's hormonal status may be correlated with alterations in both neuronal and behavioral indices of fear. PMID:19428610

Carbon-neutral energy cycles using alcohols.

PubMed

Fukushima, Takashi; Kitano, Sho; Hata, Shinichi; Yamauchi, Miho

2018-01-01

We demonstrated carbon-neutral (CN) energy circulation using glycolic acid ( GC )/oxalic acid ( OX ) redox couple. Here, we report fundamental studies on both catalyst search for power generation process, i.e. GC oxidation, and elemental steps for fuel generation process, i.e. OX reduction, in CN cycle. The catalytic activity test on various transition metals revealed that Rh, Pd, Ir, and Pt have preferable features as a catalyst for electrochemical oxidation of GC . A carbon-supported Pt catalyst in alkaline conditions exhibited higher activity, durability, and product selectivity for electrooxidation of GC rather than those in acidic media. The kinetic study on OX reduction clearly indicated that OX reduction undergoes successive two-electron reductions to form GC . Furthermore, application of TiO 2 catalysts with large specific area for electrochemical reduction of OX facilitates the selective formation of GC .

Carbon-neutral energy cycles using alcohols

PubMed Central

Fukushima, Takashi; Kitano, Sho; Hata, Shinichi; Yamauchi, Miho

2018-01-01

Abstract We demonstrated carbon-neutral (CN) energy circulation using glycolic acid (GC)/oxalic acid (OX) redox couple. Here, we report fundamental studies on both catalyst search for power generation process, i.e. GC oxidation, and elemental steps for fuel generation process, i.e. OX reduction, in CN cycle. The catalytic activity test on various transition metals revealed that Rh, Pd, Ir, and Pt have preferable features as a catalyst for electrochemical oxidation of GC. A carbon-supported Pt catalyst in alkaline conditions exhibited higher activity, durability, and product selectivity for electrooxidation of GC rather than those in acidic media. The kinetic study on OX reduction clearly indicated that OX reduction undergoes successive two-electron reductions to form GC. Furthermore, application of TiO2 catalysts with large specific area for electrochemical reduction of OX facilitates the selective formation of GC. PMID:29511392

Biomarkers in rheumatic diseases: how can they facilitate diagnosis and assessment of disease activity?

PubMed

Mohan, Chandra; Assassi, Shervin

2015-11-26

Serological and proteomic biomarkers can help clinicians diagnose rheumatic diseases earlier and assess disease activity more accurately. These markers have been incorporated into the recently revised classification criteria of several diseases to enable early diagnosis and timely initiation of treatment. Furthermore, they also facilitate more accurate subclassification and more focused monitoring for the detection of certain disease manifestations, such as lung and renal involvement. These biomarkers can also make the assessment of disease activity and treatment response more reliable. Simultaneously, several new serological and proteomic biomarkers have become available in the routine clinical setting--for example, a protein biomarker panel for rheumatoid arthritis and a myositis antibody panel for dermatomyositis and polymyositis. This review will focus on commercially available antibody and proteomic biomarkers in rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis (scleroderma), dermatomyositis and polymyositis, and axial spondyloarthritis (including ankylosing spondylitis). It will discuss how these markers can facilitate early diagnosis as well as more accurate subclassification and assessment of disease activity in the clinical setting. The ultimate goal of current and future biomarkers in rheumatic diseases is to enable early detection of these diseases and their clinical manifestations, and to provide effective monitoring and treatment regimens that are tailored to each patient's needs and prognosis. © BMJ Publishing Group Ltd 2015.

Solar activity cycles: indication of the existence of fundamental symmetry?

NASA Astrophysics Data System (ADS)

Dreschhoff, Gisela; Wong, Kai Wai; Curatolo, Susana; Jungner, Hogne; Perry, Charles

Previous work has shown that there is a consistent pattern that seems to be underlying the various known solar activity cycles, which is fundamentally based on the nuclear magnetic resonance frequencies (NMR) of some of the main isotopic constituents within the solar core, hydrogen-1 F(H-1)NMR and helium-3 F(He-3)NMR [1], and resulting in a so-called "beat-frequency", thereby suggesting that this mechanism may involve the entire Sun. Furthermore, it was found that the energy generating region of the Sun may be governed by an optimum condition where F(He-3)NMR = F(H-1)NMR associated with an internal magnetic field of 7 Gauss, and the beat-frequency Fbeat representing the Schwabe periodicity [2]. Using the Schwabe cycle as the basic cycle length (C2), the astronomical and geophysical data (solar activity cycles C1) are represented by a fundamental harmonic progression of the form C1 = C2 x 2n. We will attempt to show that this type of harmonic progression can be viewed as being part of fundamental principles of nature, as they are evident in the mathematical expression of 2n matrices in group representations SU(n), or the superposition of two states of one particle 21, two states of two (or n) particles leading to 22 (or 2n ) possible combinations. We may show that these fundamental principles are linked to the newly developed 5D projection field theory and the realization of matter as proposed by Wong [3]. [1] C.A. Perry, Thesis 1989, University of Kansas [2] G. Dreschhoff, Adv. Space Res., 40, p. 1015-1020, 2007 [3] K.W. Wong, Nova Science, 2009, in press

Using the Solar Polar Magnetic Field for Longterm Predictions of Solar Activity, Solar Cycles 21-25

NASA Astrophysics Data System (ADS)

Pesnell, W. D.; Schatten, K. H.

2017-12-01

We briefly review the dynamo and geomagnetic precursor methods of long-term solar activity forecasting. These methods depend upon the most basic aspect of dynamo theory to predict future activity, future magnetic field arises directly from the amplification of pre-existing magnetic field. We then generalize the dynamo technique, allowing the method to be used at any phase of the solar cycle, to the Solar Dynamo Amplitude (SODA) index. This index is sensitive to the magnetic flux trapped within the Sun's convection zone but insensitive to the phase of the solar cycle. Since magnetic fields inside the Sun can become buoyant, one may think of the acronym SODA as describing the amount of buoyant flux. We will show how effective the SODA Index has been in predicting Solar Cycles 23 and 24, and present a unified picture of earlier estimates of the polar magnetic configuration in Solar Cycle 21 and 22. Using the present value of the SODA index, we estimate that the next cycle's smoothed peak activity will be about 125 ± 30 solar flux units for the 10.7 cm radio flux and a sunspot number of 70 ± 25. This suggests that Solar Cycle 25 will be comparable to Solar Cycle 24. Since the current approach uses data prior to solar minimum, these estimates may improve when the upcoming solar minimum is reached.

Age-Associated Perceptions of Physical Activity Facilitators and Barriers Among Women in Rural Southernmost Illinois

PubMed Central

Carnahan, Leslie R.; Peacock, Nadine R.

2016-01-01

Introduction Women living in rural areas in the United States experience disproportionately high rates of diseases such as obesity and heart disease and are less likely than women living in urban areas to meet daily physical activity (PA) recommendations. The purpose of our research was to understand age-specific perceptions of barriers and facilitators to rural women engaging in PA and to identify strategies to promote PA among these women. Methods As part of a community health assessment to learn about women’s health issues, 110 adult women participated in 14 focus groups. The women were divided into 4 age groups, and focus groups were held in various community settings. We used qualitative analysis methods to explore themes in the women’s narratives, including themes related to PA knowledge, PA behavior, and access to PA facilities. Results Participants described multiple and often conflicting individual, social, and environmental barriers and facilitators to PA. Several barriers and facilitators were shared across age groups (eg, competing priorities and inadequate knowledge about PA’s role in disease prevention and disease management). Other barriers (eg, illness and injury) and facilitators (eg, PA as a social opportunity) differed by age group. Conclusion Rural women in southernmost Illinois have often contradictory barriers and facilitators to PA, and those barriers and facilitators are different at different points in a woman’s life. Our findings suggest the need for multilevel, multisector approaches to promote PA. Additionally, this research supports the need for tailored PA promotion programs for rural women to address the barriers these women face across their lifespan. PMID:27685431

Perceived Benefits, Facilitators, Disadvantages, and Barriers for Physical Activity Amongst South Asian Adolescents in India and Canada.

PubMed

Rajaraman, Divya; Correa, Natasha; Punthakee, Zubin; Lear, Scott A; Jayachitra, Krishnaswamy G; Vaz, Mario; Swaminathan, Sumathi

2015-07-01

The purpose of this study was to understand perceived benefits, facilitators, disadvantages, and barriers for physical activity among South Asian adolescents in India and Canada. Thirteen focus group discussions with South Asian (origin) adolescent boys and girls of different nutritional status and socioeconomic status in rural and urban India and urban Canada. Across the groups, fitness and 'energy' were perceived to be major benefits of physical activity. In India, better academic performance was highlighted, while health benefits were well detailed in Canadian groups. In all settings, friends, family, and teachers were perceived as facilitators of as well as barriers to physical activity. Lack of a safe space to play was a major concern for urban adolescents, while academic pressures and preference for other sedentary recreational activities were common barriers across all groups. Girls were less likely than boys to be interested in physical activity, with girls' participation in India further limited by societal restrictions. The study suggests key areas for promotion of physical activity among South Asian adolescents: balance between academic pressure and opportunities for physical activity, especially in India; urban planning for a built environment conducive to physical activity; and gender-sensitive programming to promote girls' activity which also addresses culture-specific barriers.

Physical activity in South Asians: an in-depth qualitative study to explore motivations and facilitators.

PubMed

Jepson, Ruth; Harris, Fiona M; Bowes, Alison; Robertson, Roma; Avan, Ghizala; Sheikh, Aziz

2012-01-01

People of South Asian backgrounds living in the UK have a five-fold increased risk of diabetes and a two-fold increased risk of heart disease when compared to the general population. Physical activity can reduce the risk of premature death from a range of conditions. The aim of the study was to explore the motivating and facilitating factors likely to increase physical activity for South Asian adults and their families, in order to develop successful interventions and services. This was a qualitative study using focus groups and in-depth interviews. Participants were 59 purposively selected Bangladeshi-, Indian- and Pakistani-origin men and women with an additional 10 key informants. The setting was three urban areas of Scotland: Aberdeen, Glasgow and Edinburgh. We undertook a theoretically informed thematic analysis of data. Study participants described engaging in a range of physical activities, particularly football and the gym for men, and walking and swimming for women. The main motivators for taking part in physical activity were external motivators--i.e. undertaking physical activity as a means to an end, which included the opportunities that physical activity provided for social activity and enjoyment. The goals of weight reduction and improving mental and physical health and were also mentioned. Role models were seen as important to inspire and motivate people to undertake activities that they may otherwise lack confidence in. Few people undertook physical activity for its own sake (intrinsic motivation). Attempts at promoting physical activity in people of South Asian origin need to take account of the social context of people's lives and the external motivators that encourage them to engage in physical activity. Undertaking group based physical activity is important and can be facilitated through religious, community, friendship or family networks. Role models may also prove particularly helpful.

Clustered localization of STAT3 during the cell cycle detected by super-resolution fluorescence microscopy

NASA Astrophysics Data System (ADS)

Gao, Jing; Chen, Junling; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Tong, Ti; Wang, Hongda

2017-06-01

Signal transducer and activator of transcription 3 (STAT3) plays a key role in various cellular processes such as cell proliferation, differentiation, apoptosis and immune responses. In particular, STAT3 has emerged as a potential molecular target for cancer therapy. The functional role and standard activation mechanism of STAT3 have been well studied, however, the spatial distribution of STAT3 during the cell cycle is poorly known. Therefore, it is indispensable to study STAT3 spatial arrangement and nuclear-cytoplasimic localization at the different phase of cell cycle in cancer cells. By direct stochastic optical reconstruction microscopy imaging, we find that STAT3 forms various number and size of clusters at the different cell-cycle stage, which could not be clearly observed by conventional fluorescent microscopy. STAT3 clusters get more and larger gradually from G1 to G2 phase, during which time transcription and other related activities goes on consistently. The results suggest that there is an intimate relationship between the clustered characteristic of STAT3 and the cell-cycle behavior. Meanwhile, clustering would facilitate STAT3 rapid response to activating signals due to short distances between molecules. Our data might open a new door to develop an antitumor drug for inhibiting STAT3 signaling pathway by destroying its clusters.

Retrieval of the photochemical reflectance index for assessing xanthophyll cycle activity: a comparison of near-surface optical sensors

NASA Astrophysics Data System (ADS)

Harris, A.; Gamon, J.; Pastorello, G. Z.; Wong, C.

2014-08-01

Unattended optical sensors are increasingly being deployed on eddy covariance flux towers and are often used to complement existing vegetation and micrometeorological measurements to enable assessment of biophysical states and biogeochemical processes over a range of spatial scales. Of particular interest are sensors that can measure the photochemical reflectance index (PRI), which can provide information pertaining to leaf pigments and photosynthetic activity. This interest has facilitated the production of a new range of lower-cost sensors specifically designed to measure temporal changes in the PRI signal. However, little is known about the characteristics (spectral, radiometric and temporal) of many of these PRI sensors, making it difficult to compare data obtained from these sensors across time, geographical locations and instruments. Furthermore, direct testing of the capability of these sensors to actually detect the conversion of the xanthophyll cycle, which is the original biological basis of the PRI diurnal signal, is largely absent, which often results in an unclear interpretation of the signal, particularly given the wide range of factors now known to influence PRI. Through a series of experiments, we assess the sensitivity of one of the leading brands of PRI sensor (Skye SKR 1800) to changes in vegetation photosynthetic activity in response to changing irradiance. We compare the results with those obtained using a more expensive industry-standard spectrometer (PP-systems UniSpec) and determine the radiometric compatibility of measurements made by the different instruments. Results suggest that the lower cost SKR 1800 instrument is able to track rapid (seconds to minutes) and more gradual diurnal changes in photosynthetic activity associated with xanthophyll cycle pigment conversion. Measurements obtained from both the high and lower cost instrument were significantly linearly correlated but were subject to a large systematic bias, illustrating that

Effects of Space Weather on Biomedical Parameters during the Solar Activity Cycles 23-24.

PubMed

Ragul'skaya, M V; Rudenchik, E A; Chibisov, S M; Gromozova, E N

2015-06-01

The results of long-term (1998-2012) biomedical monitoring of the biotropic effects of space weather are discussed. A drastic change in statistical distribution parameters in the middle of 2005 was revealed that did not conform to usual sinusoidal distribution of the biomedical data reflecting changes in the number of solar spots over a solar activity cycle. The dynamics of space weather of 2001-2012 is analyzed. The authors hypothesize that the actual change in statistical distributions corresponds to the adaptation reaction of the biosphere to nonstandard geophysical characteristics of the 24th solar activity cycle and the probable long-term decrease in solar activity up to 2067.

Regulation to Create Environments Conducive to Physical Activity: Understanding the Barriers and Facilitators at the Australian State Government Level

PubMed Central

Shill, Jane; Mavoa, Helen; Crammond, Brad; Loff, Bebe; Peeters, Anna; Lawrence, Mark; Allender, Steven; Sacks, Gary; Swinburn, Boyd A.

2012-01-01

Introduction Policy and regulatory interventions aimed at creating environments more conducive to physical activity (PA) are an important component of strategies to improve population levels of PA. However, many potentially effective policies are not being broadly implemented. This study sought to identify potential policy/regulatory interventions targeting PA environments, and barriers/facilitators to their implementation at the Australian state/territory government level. Methods In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organisations (n = 40) to examine participants': 1) suggestions for regulatory interventions to create environments more conducive to PA; 2) support for preselected regulatory interventions derived from a literature review. Thematic and constant comparative analyses were conducted. Results Policy interventions most commonly suggested by participants fell into two areas: 1) urban planning and provision of infrastructure to promote active travel; 2) discouraging the use of private motorised vehicles. Of the eleven preselected interventions presented to participants, interventions relating to walkability/cycling and PA facilities received greatest support. Interventions involving subsidisation (of public transport, PA-equipment) and the provision of more public transport infrastructure received least support. These were perceived as not economically viable or unlikely to increase PA levels. Dominant barriers were: the powerful ‘road lobby’, weaknesses in the planning system and the cost of potential interventions. Facilitators were: the provision of evidence, collaboration across sectors, and synergies with climate change/environment agendas. Conclusion This study points to how difficult it will be to achieve policy change when there is a powerful ‘road lobby’ and government investment prioritises road infrastructure over PA

Postnatal telomere dysfunction induces cardiomyocyte cell-cycle arrest through p21 activation

PubMed Central

Aix, Esther; Gutiérrez-Gutiérrez, Óscar; Sánchez-Ferrer, Carlota; Aguado, Tania

2016-01-01

The molecular mechanisms that drive mammalian cardiomyocytes out of the cell cycle soon after birth remain largely unknown. Here, we identify telomere dysfunction as a critical physiological signal for cardiomyocyte cell-cycle arrest. We show that telomerase activity and cardiomyocyte telomere length decrease sharply in wild-type mouse hearts after birth, resulting in cardiomyocytes with dysfunctional telomeres and anaphase bridges and positive for the cell-cycle arrest protein p21. We further show that premature telomere dysfunction pushes cardiomyocytes out of the cell cycle. Cardiomyocytes from telomerase-deficient mice with dysfunctional telomeres (G3 Terc−/−) show precocious development of anaphase-bridge formation, p21 up-regulation, and binucleation. In line with these findings, the cardiomyocyte proliferative response after cardiac injury was lost in G3 Terc−/− newborns but rescued in G3 Terc−/−/p21−/− mice. These results reveal telomere dysfunction as a crucial signal for cardiomyocyte cell-cycle arrest after birth and suggest interventions to augment the regeneration capacity of mammalian hearts. PMID:27241915

Goal conflict, goal facilitation, and health professionals' provision of physical activity advice in primary care: An exploratory prospective study

PubMed Central

2011-01-01

Background The theory of planned behaviour has well-evidenced utility in predicting health professional behaviour, but focuses on a single behaviour isolated from the numerous potentially conflicting and facilitating goal-directed behaviours performed alongside. Goal conflict and goal facilitation may influence whether health professionals engage in guideline-recommended behaviours, and may supplement the predictive power of the theory of planned behaviour. We hypothesised that goal facilitation and goal conflict contribute to predicting primary care health professionals' provision of physical activity advice to patients with hypertension, over and above predictors of behaviour from the theory of planned behaviour. Methods Using a prospective predictive design, at baseline we invited a random sample of 606 primary care health professionals from all primary care practices in NHS Grampian and NHS Tayside (Scotland) to complete postal questionnaires. Goal facilitation and goal conflict were measured alongside theory of planned behaviour constructs at baseline. At follow-up six months later, participants self-reported the number of patients, out of those seen in the preceding two weeks, to whom they provided physical activity advice. Results Forty-four primary care physicians and nurses completed measures at both time points (7.3% response rate). Goal facilitation and goal conflict improved the prediction of behaviour, accounting for substantial additional variance (5.8% and 8.4%, respectively) in behaviour over and above intention and perceived behavioural control. Conclusions Health professionals' provision of physical activity advice in primary care can be predicted by perceptions about how their conflicting and facilitating goal-directed behaviours help and hinder giving advice, over and above theory of planned behaviour constructs. Incorporating features of multiple goal pursuit into the theory of planned behaviour may help to better understand health professional

Global Account of Barriers and Facilitators of Physical Activity Among Patients with Diabetes Mellitus: A Narrative Review of the Literature.

PubMed

Adeniyi, Ade F; Anjana, Ranjit M; Weber, Mary B

2016-01-01

With diabetes rates escalating globally, there is the need for a better integration of all aspects of diabetes care for improved population outcomes. An understanding, not only of regional but global literature on physical activity barriers and its facilitators is important if healthcare providers and policy makers are to create programs tailored to their populations. Herein, we report the results of a narrative review of the global barriers and facilitators of physical activity for patients with diabetes mellitus. An in-depth literature search was conducted to identify English-language studies that examined physical activity barriers and associated facilitators among patients with diabetes mellitus. Major electronic literature databases that were searched included Google Scholar, PubMed, Hub-Med, and Highwire. Studies were available from Africa, Asia, Australia, Europe, and, predominantly North America. A total of 34 predominantly internal barriers emerged globally. The most commonly reported were time constrains, fear of provoking additional disorders, exercise venue and weather related barriers. Facilitators of physical activity were reported for most of the internal barriers (e.g. time constraints, lack of knowledge etc) while the external barriers (e.g. weather, environmental pollution etc) received only a minimal attention. Globally, patients with diabetes are confronted with an enormous number of physical activity barriers. Unlike the robust solutions proffered for the internal barriers, the literature is largely silent about solutions to the external barriers, which though fewer, may be highly influential. Additional data is needed to better understand physical activity behaviors in populations outside of North America.

Crayfish neuromuscular facilitation activated by constant presynaptic action potentials and depolarizing pulses

PubMed Central

Zucker, Robert S.

1974-01-01

1. Experiments were conducted to test the hypothesis that facilitation of transmitter release in response to repetitive stimulation of the exciter motor axon to the crayfish claw opener muscle is due to an increase in the amplitude or duration of the action potential in presynaptic terminals. No consistent changes were found in the nerve terminal potential (n.t.p.) recorded extracellularly at synaptic sites on the surface of muscle fibres. 2. Apparent changes in n.t.p. are attributed to three causes. (i) Some recordings are shown to be contaminated by non-specific muscle responses which grow during facilitation. (ii) Some averaged n.t.p.s exhibit opposite changes in amplitude and duration which suggest a change in the synchrony of presynaptic nerve impulses at different frequencies. (iii) Some changes in n.t.p. are blocked by γ-methyl glutamate, an antagonist of the post-synaptic receptor, which suggests that these changes are caused by small muscle movements. 3. The only change in n.t.p. believed to represent an actual change in the intracellular signal is a reduction in n.t.p. amplitude to the second of two stimuli separated by a brief interval. 4. Tetra-ethyl ammonium ions increase synaptic transmission about 20% and prolong the n.t.p. about 15%. This result suggests that an increase in n.t.p. large enough to increase transmission by the several hundred per cent occurring during facilitation would be detected. 5. The nerve terminals are electrically excitable, and most synaptic sites have a diphasic or triphasic n.t.p., which suggests that the motor neurone terminals are actively invaded by nerve impulses. 6. When nerve impulses are blocked in tetrodotoxin, depolarization of nerve terminals increases the frequency of miniature excitatory junctional potentials (e.j.p.s), and a phasic e.j.p. can be evoked by large, brief depolarizing pulses. Responses to repetitive or paired depolarizations of constant amplitude and duration exhibit a facilitation similar to that

Crayfish neuromuscular facilitation activated by constant presynaptic action potentials and depolarizing pulses.

PubMed

Zucker, R S

1974-08-01

1. Experiments were conducted to test the hypothesis that facilitation of transmitter release in response to repetitive stimulation of the exciter motor axon to the crayfish claw opener muscle is due to an increase in the amplitude or duration of the action potential in presynaptic terminals. No consistent changes were found in the nerve terminal potential (n.t.p.) recorded extracellularly at synaptic sites on the surface of muscle fibres.2. Apparent changes in n.t.p. are attributed to three causes.(i) Some recordings are shown to be contaminated by non-specific muscle responses which grow during facilitation.(ii) Some averaged n.t.p.s exhibit opposite changes in amplitude and duration which suggest a change in the synchrony of presynaptic nerve impulses at different frequencies.(iii) Some changes in n.t.p. are blocked by gamma-methyl glutamate, an antagonist of the post-synaptic receptor, which suggests that these changes are caused by small muscle movements.3. The only change in n.t.p. believed to represent an actual change in the intracellular signal is a reduction in n.t.p. amplitude to the second of two stimuli separated by a brief interval.4. Tetra-ethyl ammonium ions increase synaptic transmission about 20% and prolong the n.t.p. about 15%. This result suggests that an increase in n.t.p. large enough to increase transmission by the several hundred per cent occurring during facilitation would be detected.5. The nerve terminals are electrically excitable, and most synaptic sites have a diphasic or triphasic n.t.p., which suggests that the motor neurone terminals are actively invaded by nerve impulses.6. When nerve impulses are blocked in tetrodotoxin, depolarization of nerve terminals increases the frequency of miniature excitatory junctional potentials (e.j.p.s), and a phasic e.j.p. can be evoked by large, brief depolarizing pulses. Responses to repetitive or paired depolarizations of constant amplitude and duration exhibit a facilitation similar to that of e

Inducing myoblast re-entry into the cell cycle: a potential mechanism for laser-enhanced skeletal muscle regeneration

NASA Astrophysics Data System (ADS)

Liu, T.; Fang, Y.; Zhang, C. P.; Chen, P.; Wang, C. Z.; Kang, H. X.; Shen, B. J.; Liang, J.; Fu, X. B.

2014-09-01

This study investigated the effect of low-level laser irradiation (LLLI) on the cell cycle and proliferative activity of cultured myoblasts, and sought to elucidate the possible cellular mechanism by which LLLI promotes the regeneration of skeletal muscle in vivo. Primary myoblasts isolated from rat hindlegs were irradiated with helium-neon laser light at different energy densities. Distributions of cell-cycle subpopulations and the expression of cell-cycle regulatory proteins in myoblasts were assessed using flow cytometric analysis and western blot assay. It was found that laser irradiation stimulated cell-cycle entry; induced the expression of cyclin A and cyclin D; and increased cell proliferation index and bromodeoxyuridine incorporation as compared to the unirradiated control cells, indicating LLLI augmented the number of proliferative myoblasts in the S phase and G2/M phase of the cell cycle. These results suggest that LLLI at certain fluxes and wavelengths could activate quiescent myoblasts, leading to cell division and facilitating new myofiber formation. This could contribute to the improvement of skeletal muscle regeneration following trauma and myopathic diseases.

Cannabinoid receptor activation inhibits cell cycle progression by modulating 14-3-3β.

PubMed

Jung, Hye-Won; Park, Inae; Ghil, Sungho

2014-09-01

Cannabinoids display various pharmacological activities, including tumor regression, anti-inflammatory and neuroprotective effects. To investigate the molecular mechanisms underlying the pharmacological effects of cannabinoids, we used a yeast two-hybrid system to screen a mouse brain cDNA library for proteins interacting with type 1 cannabinoid receptor (CB1R). Using the intracellular loop 3 of CB1R as bait, we identified 14-3-3β as an interacting partner of CB1R and confirmed their interaction using affinity-binding assays. 14-3-3β has been reported to induce a cell cycle delay at the G2/M phase. We tested the effects of cannabinoids on cell cycle progression in HeLa cells synchronized using a double-thymidine block-and-release protocol and found an increase in the population of G2/M phase cells. We further found that CB1R activation augmented the interaction of 14-3-3β with Wee1 and Cdc25B, and promoted phosphorylation of Cdc2 at Tyr-15. These results suggest that cannabinoids induce cell cycle delay at the G2/M phase by activating 14-3-3β.

Effectiveness and student perceptions of an active learning activity using a headline news story to enhance in-class learning of cell cycle regulation.

PubMed

Dirks-Naylor, Amie J

2016-06-01

An active learning activity was used to engage students and enhance in-class learning of cell cycle regulation in a PharmD level integrated biological sciences course. The aim of the present study was to determine the effectiveness and perception of the in-class activity. After completion of a lecture on the topic of cell cycle regulation, students completed a 10-question multiple-choice quiz before and after engaging in the activity. The activity involved reading of a headline news article published by ScienceDaily.com entitled "One Gene Lost Equals One limb Regained." The name of the gene was deleted from the article and, thus, the end goal of the activity was to determine the gene of interest by the description in the story. The activity included compiling a list of all potential gene candidates before sufficient information was given to identify the gene of interest (p21). A survey was completed to determine student perceptions of the activity. Quiz scores improved by an average of 20% after the activity (40.1 ± 1.95 vs. 59.9 ± 2.14,P< 0.0001,n= 96). Students enjoyed the activity, found the news article interesting, and believed that the activity improved their understanding of cell cycle regulation. The majority of students agreed that the in-class activity piqued their interest for learning the subject matter and also agreed that if they understand a concept during class, they are more likely to want to study that concept outside of class. In conclusion, the activity improved in-class understanding and enhanced interest in cell cycle regulation. Copyright © 2016 The American Physiological Society.

Increasing active travel: results of a quasi-experimental study of an intervention to encourage walking and cycling.

PubMed

Keall, Michael; Chapman, Ralph; Howden-Chapman, Philippa; Witten, Karen; Abrahamse, Wokje; Woodward, Alistair

2015-12-01

There is increased interest in the effectiveness and co-benefits of measures to promote walking and cycling, including health gains from increased physical activity and reductions in fossil fuel use and vehicle emissions. This paper analyses the changes in walking and cycling in two New Zealand cities that accompanied public investment in infrastructure married with programmes to encourage active travel. Using a quasi-experimental two-group pre-post study design, we estimated changes in travel behaviour from baseline in 2011 to mid-programme in 2012, and postprogramme in 2013. The intervention and control cities were matched in terms of sociodemographic variables and baseline levels of walking and cycling. A face-to-face survey obtained information on walking and cycling. We also drew from the New Zealand Travel Survey, a national ongoing survey of travel behaviour, which was conducted in the study areas. Estimates from the two surveys were combined using meta-analysis techniques. The trips and physical activity were evaluated. Relative to the control cities, the odds of trips being by active modes (walking or cycling) increased by 37% (95% CI 8% to 73%) in the intervention cities between baseline and postintervention. The net proportion of trips made by active modes increased by about 30%. In terms of physical activity levels, there was little evidence of an overall change. Comparing the intervention cities with the matched controls, we found substantial changes in walking and cycling, and conclude that the improvements in infrastructure and associated programmes appear to have successfully arrested the general decline in active mode use evident in recent years. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Metabolic interaction between urea cycle and citric acid cycle shunt: A guided approach.

PubMed

Pesi, Rossana; Balestri, Francesco; Ipata, Piero L

2018-03-01

This article is a guided pedagogical approach, devoted to postgraduate students specializing in biochemistry, aimed at presenting all single reactions and overall equations leading to the metabolic interaction between ureagenesis and citric acid cycle to be incorporated into a two-three lecture series about the interaction of urea cycle with other metabolic pathways. We emphasize that citrate synthetase, aconitase, and isocitrate dehydrogenase, three enzymes of the citric acid cycle are not involved, thus creating a shunt in citric acid cycle. In contrast, the glutamic-oxaloacetate transaminase, which does not belong to citric acid cycle, has a paramount importance in the metabolic interaction of the two cycles, because it generates aspartate, one of the two fuel molecules of urea cycle, and a-ketoglutarate, an intermediate of the citric acid cycle. Finally, students should appreciate that balancing equations for all atoms and charges is not only a stoichiometric task, but strongly facilitates the discussion of the physiological roles of metabolic pathways. Indeed, this exercise has been used in the classroom, to encourage a deeper level of understanding of an important biochemical issue. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):182-185, 2018. © 2017 The International Union of Biochemistry and Molecular Biology.

STAT3-activated CD36 facilitates fatty acid uptake in chronic lymphocytic leukemia cells

PubMed Central

Rozovski, Uri; Harris, David M.; Li, Ping; Liu, Zhiming; Jain, Preetesh; Ferrajoli, Alessandra; Burger, Jan; Thompson, Phillip; Jain, Nitin; Wierda, William; Keating, Michael J.; Estrov, Zeev

2018-01-01

Although several studies established that unlike normal B cells chronic lymphocytic leukemia (CLL) cells metabolize fatty acids (FA), how CLL cells internalize FA is poorly understood. Because in various cell types CD36 facilitates FA uptake, we wondered whether a similar mechanism is operative CLL. We found that CD36 levels are higher in CLL cells than in normal B cells, and that small interfering RNA, CD36 neutralizing antibodies or sulfosuccinimidyl oleate (SSO) that inhibits CD36 significantly reduced the oxygen consumption of CLL cells incubated with FA. Because CD36 is oeverexpressed and STAT3 is constitutively activated in CLL cells, we wondered whether STAT3 induces CD36 expression. Sequence analysis identified putative STAT3 binding sites in the CD36 gene promoter. Chromatin immunoprecipitation and an electrophoretic mobility shift assay revealed that STAT3 binds to the CD36 gene promoter. A luciferase assay and STAT3-small hairpin RNA, that significantly decreased the levels of CD36 in CLL cells, established that STAT3 activates the transcription of the CD36 gene. Furthermore, SSO induced a dose-dependent apoptosis of CLL cells. Taken together, our data suggest that STAT3 activates CD36 and that CD36 facilitates FA uptake in CLL cells. Whether CD36 inhibition would provide clinical benefits in CLL remains to be determined. PMID:29765537

Demonstration of active vibration control on a stirling-cycle cryocooler testbed

NASA Technical Reports Server (NTRS)

Johnson, Bruce G.; Flynn, Frederick J.; Gaffney, Monique S.; Johnson, Dean L.; Ross, Ronald G., Jr.

1992-01-01

SatCon Technology Corporation has demonstrated excellent vibration reduction performance using active control on the JPL Stirling-cycle cryocooler testbed. The authors address the use of classical narrowband feedback control to meet the cryocooler vibration specifications using one cryocooler in a self-cancellation configuration. Similar vibration reduction performance was obtained using a cryocooler back-to-back configuration by actively controlling a reaction mass actuator that was used to mimic the second cooler.

Barriers to and Facilitators of Physical Activity Program Use Among Older Adults

PubMed Central

Bethancourt, Hilary J.; Rosenberg, Dori E.; Beatty, Tara; Arterburn, David E.

2014-01-01

Objective Regular physical activity (PA) is important for maintaining long-term physical, cognitive, and emotional health. However, few older adults engage in routine PA, and even fewer take advantage of programs designed to enhance PA participation. Though most managed Medicare members have free access to the Silver Sneakers and EnhanceFitness PA programs, the vast majority of eligible seniors do not utilize these programs. The goal of this qualitative study was to better understand the barriers to and facilitators of PA and participation in PA programs among older adults. Design This was a qualitative study using focus group interviews. Setting Focus groups took place at three Group Health clinics in King County, Washington. Participants Fifty-two randomly selected Group Health Medicare members between the ages of 66 to 78 participated. Methods We conducted four focus groups with 13 participants each. Focus group discussions were audio-recorded, transcribed, and analyzed using an inductive thematic approach and a social-ecological framework. Results Men and women were nearly equally represented among the participants, and the sample was largely white (77%), well-educated (69% college graduates), and relatively physically active. Prominent barriers to PA and PA program participation were physical limitations due to health conditions or aging, lack of professional guidance, and inadequate distribution of information on available and appropriate PA options and programs. Facilitators included the motivation to maintain physical and mental health and access to affordable, convenient, and stimulating PA options. Conclusion Older adult populations may benefit from greater support and information from their providers and health care systems on how to safely and successfully improve or maintain PA levels through later adulthood. Efforts among health care systems to boost PA among older adults may need to consider patient-centered adjustments to current PA programs, as

Sub- and Quasi-Centurial Cycles in Solar and Geomagnetic Activity Data Series

NASA Astrophysics Data System (ADS)

Komitov, B.; Sello, S.; Duchlev, P.; Dechev, M.; Penev, K.; Koleva, K.

2016-07-01

The subject of this paper is the existence and stability of solar cycles with durations in the range of 20-250 years. Five types of data series are used: 1) the Zurich series (1749-2009 AD), the mean annual International sunspot number Ri, 2) the Group sunspot number series Rh (1610-1995 AD), 3) the simulated extended sunspot number from Extended time series of Solar Activity Indices (ESAI) (1090-2002 AD), 4) the simulated extended geomagnetic aa-index from ESAI (1099-2002 AD), 5) the Meudon filament series (1919-1991 AD). Two principally independent methods of time series analysis are used: the T-R periodogram analysis (both in standard and ``scanning window'' regimes) and the wavelet-analysis. The obtained results are very similar. A strong cycle with a mean duration of 55-60 years is found to exist in all series. On the other hand, a strong and stable quasi 110-120 years and ˜200-year cycles are obtained in all of these series except in the Ri one. The high importance of the long term solar activity dynamics for the aims of solar dynamo modeling and predictions is especially noted.

Adolescents' Perspectives on the Barriers and Facilitators of Physical Activity: A Systematic Review of Qualitative Studies

ERIC Educational Resources Information Center

Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

2015-01-01

This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of "Web of Science", "EBSCO", "Psychinfo" and "ERIC" databases was performed according to Preferred Reporting Items for Systematic…

Spinal atypical protein kinase C activity is necessary to stabilize inactivity-induced phrenic motor facilitation

PubMed Central

Strey, K.A.; Nichols, N.L.; Baertsch, N.A.; Broytman, O.; Baker-Herman, T.L.

2012-01-01

The neural network controlling breathing must establish rhythmic motor output at a level adequate to sustain life. Reduced respiratory neural activity elicits a novel form of plasticity in circuits driving the diaphragm known as inactivity-induced phrenic motor facilitation (iPMF), a rebound increase in phrenic inspiratory output observed once respiratory neural drive is restored. The mechanisms underlying iPMF are unknown. Here, we demonstrate in anesthetized rats that spinal mechanisms give rise to iPMF, and that iPMF consists of at least two mechanistically distinct phases: 1) an early, labile phase that requires atypical PKC (PKCζ and/or PKCΙ/λ) activity to transition to a 2) late, stable phase. Early (but not late) iPMF is associated with increased interactions between PKCζ/Ι and the scaffolding protein ZIP/p62 in spinal regions associated with the phrenic motor pool. Although PKCζ/Ι activity is necessary for iPMF, spinal aPKC activity is not necessary for phrenic long-term facilitation (pLTF) following acute intermittent hypoxia, an activity-independent form of spinal respiratory plasticity. Thus, while iPMF and pLTF both manifest as prolonged increases in phrenic burst amplitude, they arise from distinct spinal cellular pathways. Our data are consistent with the hypotheses that: 1) local mechanisms sense and respond to reduced respiratory-related activity in the phrenic motor pool, and 2) inactivity-induced increases in phrenic inspiratory output require local PKCζ/Ι activity to stabilize into a long-lasting iPMF. Although the physiological role of iPMF is unknown, we suspect that iPMF represents a compensatory mechanism, assuring adequate motor output in a physiological system where prolonged inactivity ends life. PMID:23152633

A Blended Approach to Active Learning in a Physiology Laboratory-Based Subject Facilitated by an e-Learning Component

ERIC Educational Resources Information Center

Dantas, Arianne M.; Kemm, Robert E.

2008-01-01

Learning via online activities (e-learning) was introduced to facilitate existing face-to-face teaching to encourage more effective student preparation and then informed participation in an undergraduate physiology laboratory-based course. Active learning was encouraged by hypothesis formation and predictions prior to classes, with opportunities…

Exploring Potential of Crowdsourced Geographic Information in Studies of Active Travel and Health: Strava Data and Cycling Behaviour

NASA Astrophysics Data System (ADS)

Sun, Y.

2017-09-01

In development of sustainable transportation and green city, policymakers encourage people to commute by cycling and walking instead of motor vehicles in cities. One the one hand, cycling and walking enables decrease in air pollution emissions. On the other hand, cycling and walking offer health benefits by increasing people's physical activity. Earlier studies on investigating spatial patterns of active travel (cycling and walking) are limited by lacks of spatially fine-grained data. In recent years, with the development of information and communications technology, GPS-enabled devices are popular and portable. With smart phones or smart watches, people are able to record their cycling or walking GPS traces when they are moving. A large number of cyclists and pedestrians upload their GPS traces to sport social media to share their historical traces with other people. Those sport social media thus become a potential source for spatially fine-grained cycling and walking data. Very recently, Strava Metro offer aggregated cycling and walking data with high spatial granularity. Strava Metro aggregated a large amount of cycling and walking GPS traces of Strava users to streets or intersections across a city. Accordingly, as a kind of crowdsourced geographic information, the aggregated data is useful for investigating spatial patterns of cycling and walking activities, and thus is of high potential in understanding cycling or walking behavior at a large spatial scale. This study is a start of demonstrating usefulness of Strava Metro data for exploring cycling or walking patterns at a large scale.

Development of engine activity cycles for the prime movers of unconventional natural gas well development.

PubMed

Johnson, Derek; Heltzel, Robert; Nix, Andrew; Barrow, Rebekah

2017-03-01

With the advent of unconventional natural gas resources, new research focuses on the efficiency and emissions of the prime movers powering these fleets. These prime movers also play important roles in emissions inventories for this sector. Industry seeks to reduce operating costs by decreasing the required fuel demands of these high horsepower engines but conducting in-field or full-scale research on new technologies is cost prohibitive. As such, this research completed extensive in-use data collection efforts for the engines powering over-the-road trucks, drilling engines, and hydraulic stimulation pump engines. These engine activity data were processed in order to make representative test cycles using a Markov Chain, Monte Carlo (MCMC) simulation method. Such cycles can be applied under controlled environments on scaled engines for future research. In addition to MCMC, genetic algorithms were used to improve the overall performance values for the test cycles and smoothing was applied to ensure regression criteria were met during implementation on a test engine and dynamometer. The variations in cycle and in-use statistics are presented along with comparisons to conventional test cycles used for emissions compliance. Development of representative, engine dynamometer test cycles, from in-use activity data, is crucial in understanding fuel efficiency and emissions for engine operating modes that are different from cycles mandated by the Code of Federal Regulations. Representative cycles were created for the prime movers of unconventional well development-over-the-road (OTR) trucks and drilling and hydraulic fracturing engines. The representative cycles are implemented on scaled engines to reduce fuel consumption during research and development of new technologies in controlled laboratory environments.

The Relationship between Leisure Constraints, Constraint Negotiation Strategies and Facilitators with Recreational Sport Activity Participation of College Students

ERIC Educational Resources Information Center

Kocak, Funda

2017-01-01

The aim of this study is to determine the constraints in participating the leisure activities for college students, the strategies of negotiation regarding these constraints and the relationship between the facilitators and activity participation. The population of the study consists of currently registered students from Ankara University.…

Diary of a Wimpy Cycle

NASA Technical Reports Server (NTRS)

Hathaway, David; Upton, Lisa

2013-01-01

The cause of the low and extended minimum in solar activity between Sunspot Cycles 23 and 24 was the small size of Sunspot Cycle 24 itself - small cycles start late and leave behind low minima. Cycle 24 is small because the polar fields produced during Cycle 23 were substantially weaker than those produced during the previous cycles and those (weak) polar fields are the seeds for the activity of the following cycle. Here we discuss the observed characteristics of Cycle 24 and contrast them to the characteristics of previous cycles. We present observations and Magnetic Flux Transport simulations with data assimilated from SOHO/MDI and SDO/HMI that help to explain these differences and point the way to predictions of future activity levels.

Tidal, daily, and lunar-day activity cycles in the marine polychaete Nereis virens.

PubMed

Last, Kim S; Bailhache, Thierry; Kramer, Cas; Kyriacou, Charalambos P; Rosato, Ezio; Olive, Peter J W

2009-02-01

The burrow emergence activity of the wild caught ragworm Nereis virens Sars associated with food prospecting was investigated under various photoperiodic (LD) and simulated tidal cycles (STC) using a laboratory based actograph. Just over half (57%) of the animals under LD with STC displayed significant tidal (approximately 12.4 h) and/or lunar-day (approximately 24.8 h) activity patterns. Under constant light (LL) plus a STC, 25% of all animals were tidal, while one animal responded with a circadian (24.2 h) activity rhythm suggestive of cross-modal entrainment where the environmental stimulus of one period entrains rhythmic behavior of a different period. All peaks of activity under a STC, apart from that of the individual cross-modal entrainment case, coincided with the period of tank flooding. Under only LD without a STC, 49% of the animals showed nocturnal (approximately 24 h) activity. When animals were maintained under free-running LL conditions, 15% displayed significant rhythmicity with circatidal and circadian/circalunidian periodicities. Although activity cycles in N. virens at the population level are robust, at the individual level they are particularly labile, suggesting complex biological clock-control with multiple clock output pathways.

Four-month chromospheric and coronal activity cycle in τ Boötis

NASA Astrophysics Data System (ADS)

Mittag, M.; Robrade, J.; Schmitt, J. H. M. M.; Hempelmann, A.; González-Pérez, J. N.; Schröder, K.-P.

2017-04-01

We have used our robotic TIGRE facility to closely monitor the star τ Boo during the last three observing seasons 2013-2016 and to determine its S-index variability from the strength of its Ca II H and K line cores in order to study its characteristic cyclic chromospheric variations and determine its rotation period. We furthermore reanalyze archival X-ray data of τ Boo taken with the XMM-Newton satellite. Using Lomb-Scargle periodograms, we find a strong periodic signal in our data with a period of about 122 days with extremely high significance, which is also consistent with the observed long-term X-ray variability. Furthermore, the epochs of magnetic field reversals observed in τ Boo with the technique of Zeeman Doppler imaging are consistent with the hypothesis that they are produced at activity maximum. In line with previous studies of τ Boo, we therefore interpret our data as evidence of a very short activity cycle in analogy to the solar cycle, but the cycle period of τ Boo may also show some slight variability and may show substantial phase shifts. The chromospheric signal of τ Boo is found to vary on the rotational timescale of somewhat more than three days only during one out of the available three observing seasons. The available data suggest that persistent cyclic magnetic activity can occur on timescales much shorter than the decadal timescale observed for the Sun and many other late-type stars.

Enriching step-based product information models to support product life-cycle activities

NASA Astrophysics Data System (ADS)

Sarigecili, Mehmet Ilteris

The representation and management of product information in its life-cycle requires standardized data exchange protocols. Standard for Exchange of Product Model Data (STEP) is such a standard that has been used widely by the industries. Even though STEP-based product models are well defined and syntactically correct, populating product data according to these models is not easy because they are too big and disorganized. Data exchange specifications (DEXs) and templates provide re-organized information models required in data exchange of specific activities for various businesses. DEXs show us it would be possible to organize STEP-based product models in order to support different engineering activities at various stages of product life-cycle. In this study, STEP-based models are enriched and organized to support two engineering activities: materials information declaration and tolerance analysis. Due to new environmental regulations, the substance and materials information in products have to be screened closely by manufacturing industries. This requires a fast, unambiguous and complete product information exchange between the members of a supply chain. Tolerance analysis activity, on the other hand, is used to verify the functional requirements of an assembly considering the worst case (i.e., maximum and minimum) conditions for the part/assembly dimensions. Another issue with STEP-based product models is that the semantics of product data are represented implicitly. Hence, it is difficult to interpret the semantics of data for different product life-cycle phases for various application domains. OntoSTEP, developed at NIST, provides semantically enriched product models in OWL. In this thesis, we would like to present how to interpret the GD & T specifications in STEP for tolerance analysis by utilizing OntoSTEP.

Facilitators and Barriers to HIV Activities in Religious Congregations: Perspectives of Clergy and Lay Leaders from a Diverse Urban Sample

PubMed Central

Derose, Kathryn Pitkin; Werber, Laura; Palar, Kartika; Kanouse, David E.; Mata, Michael

2013-01-01

This paper examines facilitators and barriers to HIV activities within religious congregations, the relative internal or external sources of these influences, and suggestive differences across congregational types. Results are based on in-depth interviews with clergy and lay leaders (n = 57) from 14 congregations in Los Angeles County, California, purposively selected to reflect diversity in racial-ethnic composition, denomination, size, and HIV activity level. Many common facilitators and barriers were related to norms and attitudes, only a few of which appeared overtly associated with theological orientations. Clergy support was a facilitator particularly prevalent among congregations having higher HIV activity levels, indicating its importance in sustaining and expanding HIV programs. Resource issues were also prominent, with material resource barriers more frequently mentioned by smaller congregations and human resource barriers more among larger congregations. Organizational structure issues were mostly centered on external linkages with various social service, public health, and faith-based entities. Analysis of internal versus external sources highlights the roles of different stakeholders within and outside congregations in promoting HIV activities. Potential differences across congregational types represent fruitful areas for future research. PMID:23990037

Local palmitoylation cycles define activity-regulated postsynaptic subdomains

PubMed Central

Fukata, Yuko; Dimitrov, Ariane; Boncompain, Gaelle; Vielemeyer, Ole

2013-01-01

Distinct PSD-95 clusters are primary landmarks of postsynaptic densities (PSDs), which are specialized membrane regions for synapses. However, the mechanism that defines the locations of PSD-95 clusters and whether or how they are reorganized inside individual dendritic spines remains controversial. Because palmitoylation regulates PSD-95 membrane targeting, we combined a conformation-specific recombinant antibody against palmitoylated PSD-95 with live-cell super-resolution imaging and discovered subsynaptic nanodomains composed of palmitoylated PSD-95 that serve as elementary units of the PSD. PSD-95 in nanodomains underwent continuous de/repalmitoylation cycles driven by local palmitoylating activity, ensuring the maintenance of compartmentalized PSD-95 clusters within individual spines. Plasma membrane targeting of DHHC2 palmitoyltransferase rapidly recruited PSD-95 to the plasma membrane and proved essential for postsynaptic nanodomain formation. Furthermore, changes in synaptic activity rapidly reorganized PSD-95 nano-architecture through plasma membrane–inserted DHHC2. Thus, the first genetically encoded antibody sensitive to palmitoylation reveals an instructive role of local palmitoylation machinery in creating activity-responsive PSD-95 nanodomains, contributing to the PSD (re)organization. PMID:23836932

Activation of Ras-ERK Signaling and GSK-3 by Amyloid Precursor Protein and Amyloid Beta Facilitates Neurodegeneration in Alzheimer's Disease.

PubMed

Kirouac, Lisa; Rajic, Alexander J; Cribbs, David H; Padmanabhan, Jaya

2017-01-01

It is widely accepted that amyloid β (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in Alzheimer's disease (AD), yet little is known about the contribution of APP to intracellular signaling events preceding AD pathogenesis. The data presented here demonstrate that APP expression and neuronal exposure to oligomeric Aβ42 enhance Ras/ERK signaling cascade and glycogen synthase kinase 3 (GSK-3) activation. We find that RNA interference (RNAi)-directed knockdown of APP in B103 rat neuroblastoma cells expressing APP inhibits Ras-ERK signaling and GSK-3 activation, indicating that APP acts upstream of these signal transduction events. Both ERK and GSK-3 are known to induce hyperphosphorylation of tau and APP at Thr668, and our findings suggest that aberrant signaling by APP facilitates these events. Supporting this notion, analysis of human AD brain samples showed increased expression of Ras, activation of GSK-3, and phosphorylation of APP and tau, which correlated with Aβ levels in the AD brains. Furthermore, treatment of primary rat neurons with Aβ recapitulated these events and showed enhanced Ras-ERK signaling, GSK-3 activation, upregulation of cyclin D1, and phosphorylation of APP and tau. The finding that Aβ induces Thr668 phosphorylation on APP, which enhances APP proteolysis and Aβ generation, denotes a vicious feedforward mechanism by which APP and Aβ promote tau hyperphosphorylation and neurodegeneration in AD. Based on these results, we hypothesize that aberrant proliferative signaling by APP plays a fundamental role in AD neurodegeneration and that inhibition of this would impede cell cycle deregulation and neurodegeneration observed in AD.

Galactic Cosmic Ray Intensity in the Upcoming Minimum of the Solar Activity Cycle

NASA Astrophysics Data System (ADS)

Krainev, M. B.; Bazilevskaya, G. A.; Kalinin, M. S.; Svirzhevskaya, A. K.; Svirzhevskii, N. S.

2018-03-01

During the prolonged and deep minimum of solar activity between cycles 23 and 24, an unusual behavior of the heliospheric characteristics and increased intensity of galactic cosmic rays (GCRs) near the Earth's orbit were observed. The maximum of the current solar cycle 24 is lower than the previous one, and the decline in solar and, therefore, heliospheric activity is expected to continue in the next cycle. In these conditions, it is important for an understanding of the process of GCR modulation in the heliosphere, as well as for applied purposes (evaluation of the radiation safety of planned space flights, etc.), to estimate quantitatively the possible GCR characteristics near the Earth in the upcoming solar minimum ( 2019-2020). Our estimation is based on the prediction of the heliospheric characteristics that are important for cosmic ray modulation, as well as on numeric calculations of GCR intensity. Additionally, we consider the distribution of the intensity and other GCR characteristics in the heliosphere and discuss the intercycle variations in the GCR characteristics that are integral for the whole heliosphere (total energy, mean energy, and charge).

Relationships between solar activity and climate change. [sunspot cycle effects on lower atmosphere

NASA Technical Reports Server (NTRS)

Roberts, W. O.

1974-01-01

Recurrent droughts are related to the double sunspot cycle. It is suggested that high solar activity generally increases meridional circulations and blocking patterns at high and intermediate latitudes, especially in winter. This effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission.

Prediction of solar activity from solar background magnetic field variations in cycles 21-23

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

Shepherd, Simon J.; Zharkov, Sergei I.; Zharkova, Valentina V., E-mail: s.j.shepherd@brad.ac.uk, E-mail: s.zharkov@hull.ac.uk, E-mail: valentina.zharkova@northumbria.ac.uk

2014-11-01

A comprehensive spectral analysis of both the solar background magnetic field (SBMF) in cycles 21-23 and the sunspot magnetic field in cycle 23 reported in our recent paper showed the presence of two principal components (PCs) of SBMF having opposite polarity, e.g., originating in the northern and southern hemispheres, respectively. Over a duration of one solar cycle, both waves are found to travel with an increasing phase shift toward the northern hemisphere in odd cycles 21 and 23 and to the southern hemisphere in even cycle 22. These waves were linked to solar dynamo waves assumed to form in differentmore » layers of the solar interior. In this paper, for the first time, the PCs of SBMF in cycles 21-23 are analyzed with the symbolic regression technique using Hamiltonian principles, allowing us to uncover the underlying mathematical laws governing these complex waves in the SBMF presented by PCs and to extrapolate these PCs to cycles 24-26. The PCs predicted for cycle 24 very closely fit (with an accuracy better than 98%) the PCs derived from the SBMF observations in this cycle. This approach also predicts a strong reduction of the SBMF in cycles 25 and 26 and, thus, a reduction of the resulting solar activity. This decrease is accompanied by an increasing phase shift between the two predicted PCs (magnetic waves) in cycle 25 leading to their full separation into the opposite hemispheres in cycle 26. The variations of the modulus summary of the two PCs in SBMF reveals a remarkable resemblance to the average number of sunspots in cycles 21-24 and to predictions of reduced sunspot numbers compared to cycle 24: 80% in cycle 25 and 40% in cycle 26.« less

Parvovirus Minute Virus of Mice Induces a DNA Damage Response That Facilitates Viral Replication

PubMed Central

Adeyemi, Richard O.; Landry, Sebastien; Davis, Meredith E.; Weitzman, Matthew D.; Pintel, David J.

2010-01-01

Infection by DNA viruses can elicit DNA damage responses (DDRs) in host cells. In some cases the DDR presents a block to viral replication that must be overcome, and in other cases the infecting agent exploits the DDR to facilitate replication. We find that low multiplicity infection with the autonomous parvovirus minute virus of mice (MVM) results in the activation of a DDR, characterized by the phosphorylation of H2AX, Nbs1, RPA32, Chk2 and p53. These proteins are recruited to MVM replication centers, where they co-localize with the main viral replication protein, NS1. The response is seen in both human and murine cell lines following infection with either the MVMp or MVMi strains. Replication of the virus is required for DNA damage signaling. Damage response proteins, including the ATM kinase, accumulate in viral-induced replication centers. Using mutant cell lines and specific kinase inhibitors, we show that ATM is the main transducer of the signaling events in the normal murine host. ATM inhibitors restrict MVM replication and ameliorate virus-induced cell cycle arrest, suggesting that DNA damage signaling facilitates virus replication, perhaps in part by promoting cell cycle arrest. Thus it appears that MVM exploits the cellular DNA damage response machinery early in infection to enhance its replication in host cells. PMID:20949077

Identification of fuel cycle simulator functionalities for analysis of transition to a new fuel cycle

DOE PAGES

Brown, Nicholas R.; Carlsen, Brett W.; Dixon, Brent W.; ...

2016-06-09

Dynamic fuel cycle simulation tools are intended to model holistic transient nuclear fuel cycle scenarios. As with all simulation tools, fuel cycle simulators require verification through unit tests, benchmark cases, and integral tests. Model validation is a vital aspect as well. Although compara-tive studies have been performed, there is no comprehensive unit test and benchmark library for fuel cycle simulator tools. The objective of this paper is to identify the must test functionalities of a fuel cycle simulator tool within the context of specific problems of interest to the Fuel Cycle Options Campaign within the U.S. Department of Energy smore » Office of Nuclear Energy. The approach in this paper identifies the features needed to cover the range of promising fuel cycle options identified in the DOE-NE Fuel Cycle Evaluation and Screening (E&S) and categorizes these features to facilitate prioritization. Features were categorized as essential functions, integrating features, and exemplary capabilities. One objective of this paper is to propose a library of unit tests applicable to each of the essential functions. Another underlying motivation for this paper is to encourage an international dialog on the functionalities and standard test methods for fuel cycle simulator tools.« less

Geomagnetic activity during 10 - 11 solar cycles that has been observed by old Russian observatories.

NASA Astrophysics Data System (ADS)

Seredyn, Tomasz; Wysokinski, Arkadiusz; Kobylinski, Zbigniew; Bialy, Jerzy

2016-07-01

A good knowledge of solar-terrestrial relations during past solar activity cycles could give the appropriate tools for a correct space weather forecast. The paper focuses on the analysis of the historical collections of the ground based magnetic observations and their operational indices from the period of two sunspot solar cycles 10 - 11, period 1856 - 1878 (Bartels rotations 324 - 635). We use hourly observations of H and D geomagnetic field components registered at Russian stations: St. Petersburg - Pavlovsk, Barnaul, Ekaterinburg, Nertshinsk, Sitka, and compare them to the data obtained from the Helsinki observatory. We compare directly these records and also calculated from the data of the every above mentioned station IHV indices introduced by Svalgaard (2003), which have been used for further comparisons in epochs of assumed different polarity of the heliospheric magnetic field. We used also local index C9 derived by Zosimovich (1981) from St. Petersburg - Pavlovsk data. Solar activity is represented by sunspot numbers. The correlative and continuous wavelet analyses are applied for estimation of the correctness of records from different magnetic stations. We have specially regard to magnetic storms in the investigated period and the special Carrington event of 1-2 Sep 1859. Generally studied magnetic time series correctly show variability of the geomagnetic activity. Geomagnetic activity presents some delay in relation to solar one as it is seen especially during descending and minimum phase of the even 11-year cycle. This pattern looks similarly in the case of 16 - 17 solar cycles.

Perceived Barriers, Facilitators and Benefits for Regular Physical Activity and Exercise in Patients with Rheumatoid Arthritis: A Review of the Literature.

PubMed

Veldhuijzen van Zanten, Jet J C S; Rouse, Peter C; Hale, Elizabeth D; Ntoumanis, Nikos; Metsios, George S; Duda, Joan L; Kitas, George D

2015-10-01

Rheumatoid arthritis (RA) is an autoimmune disease, which not only affects the joints but can also impact on general well-being and risk for cardiovascular disease. Regular physical activity and exercise in patients with RA have numerous health benefits. Nevertheless, the majority of patients with RA are physically inactive. This indicates that people with RA might experience additional or more severe barriers to physical activity or exercise than the general population. This narrative review provides an overview of perceived barriers, benefits and facilitators of physical activity and exercise in RA. Databases were searched for articles published until September 2014 using the terms 'rheumatoid arthritis', 'physical activity', 'exercise', 'barriers', 'facilitators', 'benefits', 'motivation', 'motivators' and 'enablers'. Similarities were found between disease-specific barriers and benefits of physical activity and exercise, e.g. pain and fatigue are frequently mentioned as barriers, but reductions in pain and fatigue are perceived benefits of physical activity and exercise. Even though exercise does not influence the existence of barriers, physically active patients appear to be more capable of overcoming them. Therefore, exercise programmes should enhance self-efficacy for exercise in order to achieve long-term physical activity and exercise behaviour. Encouragement from health professionals and friends/family are facilitators for physical activity and exercise. There is a need for interventions that support RA patients in overcoming barriers to physical activity and exercise and help sustain this important health behaviour.

Retrieval of the photochemical reflectance index for assessing xanthophyll cycle activity: a comparison of near-surface optical sensors

NASA Astrophysics Data System (ADS)

Harris, A.; Gamon, J. A.; Pastorello, G. Z.; Wong, C. Y. S.

2014-11-01

Unattended optical sensors are increasingly being deployed on eddy covariance flux towers and are often used to complement existing vegetation and micrometeorological measurements to enable assessment of biophysical states and biogeochemical processes over a range of spatial scales. Of particular interest are sensors that can measure the photochemical reflectance index (PRI), which can provide information pertaining to leaf pigments and photosynthetic activity. This interest has facilitated the production of a new range of lower-cost multispectral sensors specifically designed to measure temporal changes in the PRI signal. However, little is known about the characteristics (spectral, radiometric and temporal) of many of these PRI sensors, making it difficult to compare data obtained from these sensors across time, geographical locations and instruments. Furthermore, direct testing of the capability of these sensors to actually detect the conversion of the xanthophyll cycle, which is the original biological basis of the PRI diurnal signal, is largely absent, often resulting in an unclear interpretation of the signal, particularly given the wide range of factors now known to influence PRI. Through a series of experiments, we assess the sensitivity of one of the leading brands of PRI sensor (Skye SKR 1800) to changes in vegetation photosynthetic activity in response to changing irradiance. We compare the results with those obtained using a more expensive industry-standard visible to near-infrared hyperspectral spectrometer (PP Systems UniSpec) and determine the radiometric compatibility of measurements made by the different instruments. Results suggest that the SKR 1800 instrument is able to track rapid (seconds to minutes) and more gradual diurnal changes in photosynthetic activity associated with xanthophyll cycle pigment conversion. Measurements obtained from both the high and lower cost instrument were significantly linearly correlated but were subject to a large

Results of Spectral Corona Observations in Solar Activity Cycles 17-24

NASA Astrophysics Data System (ADS)

Aliev, A. Kh.; Guseva, S. A.; Tlatov, A. G.

2017-12-01

The results of the work of the global observation network are considered, and a comparative analysis of the data of various coronal observatories is performed. The coronal activity index has been reconstructed for the period 1939-2016 based on the data of various observatories in Kislovodsk system. For this purpose, the corona daily intensity maps from the Sacramento Peak and Lomnický Štít observatories according to the Solar-Geophysical Data journal have been digitized; they supplement the data of other observatories. The homogeneity and continuity of the corona observations at the Kislovodsk station, including activity cycle 24, is confirmed. Unfortunately, the only observatory at present that continues observation of the spectral corona in Fe XIV 5303 Å and Fe XIV 6374 Å lines is the Kislovodsk astronomical station Mountain Astronomical Station (MAS) of the Central Astronomical Observatory, Russian Academy of Sciences (Pulkovo). The data on the combined corona in 5303 Å line are analyzed. It is shown that there is a high correlation of the intensity index of green corona with solar radiation measurements in the vacuum UV region. Data on the beginning of the new 25th activity cycle in the corona at high latitudes are presented.

Impact of DCS-facilitated cue exposure therapy on brain activation to cocaine cues in cocaine dependence.

PubMed

Prisciandaro, James J; Myrick, Hugh; Henderson, Scott; McRae-Clark, Aimee L; Santa Ana, Elizabeth J; Saladin, Michael E; Brady, Kathleen T

2013-09-01

The development of addiction is marked by a pathological associative learning process that imbues incentive salience to stimuli associated with drug use. Recent efforts to treat addiction have targeted this learning process using cue exposure therapy augmented with d-cycloserine (DCS), a glutamatergic agent hypothesized to enhance extinction learning. To better understand the impact of DCS-facilitated extinction on neural reactivity to drug cues, the present study reports fMRI findings from a randomized, double-blind, placebo-controlled trial of DCS-facilitated cue exposure for cocaine dependence. Twenty-five participants completed two MRI sessions (before and after intervention), with a cocaine-cue reactivity fMRI task. The intervention consisted of 50mg of DCS or placebo, combined with two sessions of cocaine cue exposure and skills training. Participants demonstrated cocaine cue activation in a variety of brain regions at baseline. From the pre- to post-study scan, participants experienced decreased activation to cues in a number of regions (e.g., accumbens, caudate, frontal poles). Unexpectedly, placebo participants experienced decreases in activation to cues in the left angular and middle temporal gyri and the lateral occipital cortex, while DCS participants did not. Three trials of DCS-facilitated cue exposure therapy for cocaine dependence have found that DCS either increases or does not significantly impact response to cocaine cues. The present study adds to this literature by demonstrating that DCS may prevent extinction to cocaine cues in temporal and occipital brain regions. Although consistent with past research, results from the present study should be considered preliminary until replicated in larger samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

5-ASA affects cell cycle progression in colorectal cells by reversibly activating a replication checkpoint.

PubMed

Luciani, M Gloria; Campregher, Christoph; Fortune, John M; Kunkel, Thomas A; Gasche, Christoph

2007-01-01

Individuals with inflammatory bowel disease are at risk of developing colorectal cancer (CRC). Epidemiologic, animal, and laboratory studies suggest that 5-amino-salicylic acid (5-ASA) protects from the development of CRC by altering cell cycle progression and by inducing apoptosis. Our previous results indicate that 5-ASA improves replication fidelity in colorectal cells, an effect that is active in reducing mutations. In this study, we hypothesized that 5-ASA restrains cell cycle progression by activating checkpoint pathways in colorectal cell lines, which would prevent tumor development and improve genomic stability. CRC cells with different genetic backgrounds such as HT29, HCT116, HCT116(p53-/-), HCT116+chr3, and LoVo were treated with 5-ASA for 2-96 hours. Cell cycle progression, phosphorylation, and DNA binding of cell cycle checkpoint proteins were analyzed. We found that 5-ASA at concentrations between 10 and 40 mmol/L affects cell cycle progression by inducing cells to accumulate in the S phase. This effect was independent of the hMLH1, hMSH2, and p53 status because it was observed to a similar extent in all cell lines under investigation. Moreover, wash-out experiments demonstrated reversibility within 48 hours. Although p53 did not have a causative role, p53 Ser15 was strongly phosphorylated. Proteins involved in the ATM-and-Rad3-related kinase (ATR)-dependent S-phase checkpoint response (Chk1 and Rad17) were also phosphorylated but not ataxia telengectasia mutated kinase. Our data demonstrate that 5-ASA causes cells to reversibly accumulate in S phase and activate an ATR-dependent checkpoint. The activation of replication checkpoint may slow down DNA replication and improve DNA replication fidelity, which increases the maintenance of genomic stability and counteracts carcinogenesis.

5-ASA Affects Cell Cycle Progression in Colorectal Cells by Reversibly Activating a Replication Checkpoint

PubMed Central

LUCIANI, M. GLORIA; CAMPREGHER, CHRISTOPH; FORTUNE, JOHN M.; KUNKEL, THOMAS A.; GASCHE, CHRISTOPH

2007-01-01

Background & Aims Individuals with inflammatory bowel disease are at risk of developing colorectal cancer (CRC). Epidemiologic, animal, and laboratory studies suggest that 5-amino-salicylic acid (5-ASA) protects from the development of CRC by altering cell cycle progression and by inducing apoptosis. Our previous results indicate that 5-ASA improves replication fidelity in colorectal cells, an effect that is active in reducing mutations. In this study, we hypothesized that 5-ASA restrains cell cycle progression by activating checkpoint pathways in colorectal cell lines, which would prevent tumor development and improve genomic stability. Methods CRC cells with different genetic backgrounds such as HT29, HCT116, HCT116p53−/−, HCT116+chr3, and LoVo were treated with 5-ASA for 2–96 hours. Cell cycle progression, phosphorylation, and DNA binding of cell cycle checkpoint proteins were analyzed. Results We found that 5-ASA at concentrations between 10 and 40 mmol/L affects cell cycle progression by inducing cells to accumulate in the S phase. This effect was independent of the hMLH1, hMSH2, and p53 status because it was observed to a similar extent in all cell lines under investigation. Moreover, wash-out experiments demonstrated reversibility within 48 hours. Although p53 did not have a causative role, p53 Ser15 was strongly phosphorylated. Proteins involved in the ATM-and-Rad3-related kinase (ATR)-dependent S-phase checkpoint response (Chk1 and Rad17) were also phosphorylated but not ataxia telengectasia mutated kinase. Conclusions Our data demonstrate that 5-ASA causes cells to reversibly accumulate in S phase and activate an ATR-dependent checkpoint. The activation of replication checkpoint may slow down DNA replication and improve DNA replication fidelity, which increases the maintenance of genomic stability and counteracts carcinogenesis. PMID:17241873

Lipotoxicity in steatohepatitis occurs despite an increase in tricarboxylic acid cycle activity

PubMed Central

Patterson, Rainey E.; Kalavalapalli, Srilaxmi; Williams, Caroline M.; Nautiyal, Manisha; Mathew, Justin T.; Martinez, Janie; Reinhard, Mary K.; McDougall, Danielle J.; Rocca, James R.; Yost, Richard A.; Cusi, Kenneth; Garrett, Timothy J.

2016-01-01

The hepatic tricarboxylic acid (TCA) cycle is central to integrating macronutrient metabolism and is closely coupled to cellular respiration, free radical generation, and inflammation. Oxidative flux through the TCA cycle is induced during hepatic insulin resistance, in mice and humans with simple steatosis, reflecting early compensatory remodeling of mitochondrial energetics. We hypothesized that progressive severity of hepatic insulin resistance and the onset of nonalcoholic steatohepatitis (NASH) would impair oxidative flux through the hepatic TCA cycle. Mice (C57/BL6) were fed a high-trans-fat high-fructose diet (TFD) for 8 wk to induce simple steatosis and NASH by 24 wk. In vivo fasting hepatic mitochondrial fluxes were determined by 13C-nuclear magnetic resonance (NMR)-based isotopomer analysis. Hepatic metabolic intermediates were quantified using mass spectrometry-based targeted metabolomics. Hepatic triglyceride accumulation and insulin resistance preceded alterations in mitochondrial metabolism, since TCA cycle fluxes remained normal during simple steatosis. However, mice with NASH had a twofold induction (P < 0.05) of mitochondrial fluxes (μmol/min) through the TCA cycle (2.6 ± 0.5 vs. 5.4 ± 0.6), anaplerosis (9.1 ± 1.2 vs. 16.9 ± 2.2), and pyruvate cycling (4.9 ± 1.0 vs. 11.1 ± 1.9) compared with their age-matched controls. Induction of the TCA cycle activity during NASH was concurrent with blunted ketogenesis and accumulation of hepatic diacylglycerols (DAGs), ceramides (Cer), and long-chain acylcarnitines, suggesting inefficient oxidation and disposal of excess free fatty acids (FFA). Sustained induction of mitochondrial TCA cycle failed to prevent accretion of “lipotoxic” metabolites in the liver and could hasten inflammation and the metabolic transition to NASH. PMID:26814015

Barriers and facilitators to participation in workplace health promotion (WHP) activities: results from a cross-sectional survey of public-sector employees in Tasmania, Australia.

PubMed

Kilpatrick, Michelle; Blizzard, Leigh; Sanderson, Kristy; Teale, Brook; Jose, Kim; Venn, Alison

2017-12-01

Issue addressed Workplaces are promising settings for health promotion, yet employee participation in workplace health promotion (WHP) activities is often low or variable. This study explored facilitating factors and barriers associated with participation in WHP activities that formed part of a comprehensive WHP initiative run within the Tasmanian State Service (TSS) between 2009 and 2013. Methods TSS employee (n=3228) completed surveys in 2013. Data included sociodemographic characteristics, employee-perceived availability of WHP activities, employee-reported participation in WHP activities, and facilitators and barriers to participation. Ordinal log-link regression was used in cross-sectional analyses. Results Significant associations were found for all facilitating factors and participation. Respondents who felt their organisation placed a high priority on WHP, who believed that management supported participation or that the activities could improve their health were more likely to participate. Time- and health-related barriers were associated with participation in fewer activities. All associations were independent of age, sex, work schedule and employee-perceived availability of programs. Part-time and shift-work patterns, and location of activities were additionally identified barriers. Conclusion Facilitating factors relating to implementation, peer and environmental support, were associated with participation in more types of activities, time- and health-related barriers were associated with less participation. So what? Large and diverse organisations should ensure WHP efforts have manager support and adopt flexible approaches to maximise employee engagement.

Identification of Novel Saccharomyces cerevisiae Proteins with Nuclear Export Activity: Cell Cycle-Regulated Transcription Factor Ace2p Shows Cell Cycle-Independent Nucleocytoplasmic Shuttling

PubMed Central

Jensen, Torben Heick; Neville, Megan; Rain, Jean Christophe; McCarthy, Terri; Legrain, Pierre; Rosbash, Michael

2000-01-01

Nuclear export of proteins containing leucine-rich nuclear export signals (NESs) is mediated by the NES receptor CRM1/Crm1p. We have carried out a yeast two-hybrid screen with Crm1p as a bait. The Crm1p-interacting clones were subscreened for nuclear export activity in a visual assay utilizing the Crm1p-inhibitor leptomycin B (LMB). This approach identified three Saccharomyces cerevisiae proteins not previously known to have nuclear export activity. These proteins are the 5′ RNA triphosphatase Ctl1p, the cell cycle-regulated transcription factor Ace2p, and a protein encoded by the previously uncharacterized open reading frame YDR499W. Mutagenesis analysis show that YDR499Wp contains an NES that conforms to the consensus sequence for leucine-rich NESs. Mutagenesis of Ctl1p and Ace2p were unable to identify specific NES residues. However, a 29-amino-acid region of Ace2p, rich in hydrophobic residues, contains nuclear export activity. Ace2p accumulates in the nucleus at the end of mitosis and activates early-G1-specific genes. We now provide evidence that Ace2p is nuclear not only in late M-early G1 but also during other stages of the cell cycle. This feature of Ace2p localization explains its ability to activate genes such as CUP1, which are not expressed in a cell cycle-dependent manner. PMID:11027275

Cycling induced by electrical stimulation improves muscle activation and symmetry during pedaling in hemiparetic patients.

PubMed

Ambrosini, Emilia; Ferrante, Simona; Ferrigno, Giancarlo; Molteni, Franco; Pedrocchi, Alessandra

2012-05-01

A randomized controlled trial, involving 35 post-acute hemiparetic patients, demonstrated that a four-week treatment of cycling induced by functional electrical stimulation (FES-cycling) promotes motor recovery. Analyzing additional data acquired during that study, the present work investigated whether these improvements were associated to changes in muscle strength and motor coordination. Participants were randomized to receive FES-cycling or placebo FES-cycling. Clinical outcome measures were: the Motricity Index (MI), the gait speed, the electromyography activation of the rectus femoris and biceps femoris, and the mechanical work produced by each leg during voluntary pedaling. To provide a comparison with normal values, healthy adults also carried out the pedaling test. Patients were evaluated before, after training, and at follow-up visits. A significant treatment effect in favor of FES-treated patients was found in terms of MI scores and unbalance in mechanical works, while differences in gait speed were not significant (ANCOVA). Significant improvements in the activation of the paretic muscles were highlighted in the FES group, while no significant change was found in the placebo group (Friedman test). Our findings suggested that improvements in motor functions induced by FES-cycling training were associated with a more symmetrical involvement of the two legs and an improved motor coordination.

US Activities in Making Life Cycle Inventory Data More Available to Users

EPA Science Inventory

The demand for LCA studies continues to grow, although, the lack of reliable, transparent Life Cycle Inventory (LCI) data is hampering the wide-spread application of LCA. This paper will present activities related to the development and accessibility of process LCI data in the U...

"I don't have the heart": a qualitative study of barriers to and facilitators of physical activity for people with coronary heart disease and depressive symptoms.

PubMed

Rogerson, Michelle C; Murphy, Barbara M; Bird, Stephen; Morris, Tony

2012-11-30

Physical activity has been shown to reduce depression in people with coronary heart disease (CHD), however many people with CHD do not engage in sufficient levels of physical activity to reap its positive effects. People with depression and CHD are at particular risk of non-adherence to physical activity. Little is known about the barriers to and facilitators of physical activity for people with CHD and depressive symptoms. Using qualitative interviews, the aim of this study was to explore the barriers to and facilitators of physical activity for cardiac patients with depressive symptoms. Fifteen participants with CHD and depressive symptoms (assessed using the Cardiac Depression Scale) participated in in-depth semi-structured interviews. The interviews were focussed on investigating participants' experiences of physical activity since their cardiac event. Interviews were content analysed to determine major themes. Participants identified a number of barriers to and facilitators of physical activity. Barriers included having negative perceptions towards health and life changes as a result of the cardiac event, having low mood and low motivation to exercise, feeling physically restricted towards or fearful of exercise, lacking knowledge regarding exercise and perceiving external barriers. Facilitators included having a reason for exercising, being able to identify the psychological benefits of exercise, having positive social support and using psychological strategies. 'Inactive' participants reported more barriers and fewer facilitators than did 'active' participants. The barriers reported in this study were highly salient for a number of participants. Health professionals and researchers can use this information to assist people with CHD and depressive symptoms to identify and possibly overcome barriers to physical activity. Relevant barriers and facilitators could be taken into account to increase their effectiveness when designing interventions to encourage

Increased resiliency and activity of microbial mediated carbon cycling enzymes in diversified bioenergy cropping systems

NASA Astrophysics Data System (ADS)

Upton, R.; Bach, E.; Hofmockel, K. S.

2017-12-01

Microbes are mediators of soil carbon (C) and are influenced in membership and activity by nitrogen (N) fertilization and inter-annual abiotic factors. Microbial communities and their extracellular enzyme activities (EEA) are important parameters that influence ecosystem C cycling properties and are often included in microbial explicit C cycling models. In an effort to generate model relevant, empirical findings, we investigated how both microbial community structure and C degrading enzyme activity are influenced by inter-annual variability and N inputs in bioenergy crops. Our study was performed at the Comparison of Biofuel Systems field-site from 2011 to 2014, in three bioenergy cropping systems, continuous corn (CC) and two restored prairies, both fertilized (FP) and unfertilized (P). We hypothesized microbial community structure would diverge during the prairie restoration, leading to changes in C cycling enzymes over time. Using a sequencing approach (16S and ITS) we determined the bacterial and fungal community structure response to the cropping system, fertilization, and inter-annual variability. Additionally, we used EEA of β-glucosidase, cellobiohydrolase, and β-xylosidase to determine inter-annual and ecosystem impacts on microbial activity. Our results show cropping system was a main effect for microbial community structure, with corn diverging from both prairies to be less diverse. Inter-annual changes showed that a drought occurring in 2012 significantly impacted microbial community structure in both the P and CC, decreasing microbial richness. However, FP increased in microbial richness, suggesting the application of N increased resiliency to drought. Similarly, the only year in which C cycling enzymes were impacted by ecosystem was 2012, with FP supporting higher potential enzymatic activity then CC and P. The highest EEA across all ecosystems occurred in 2014, suggesting the continued root biomass and litter build-up in this no till system

Data Standardization for Carbon Cycle Modeling: Lessons Learned

NASA Astrophysics Data System (ADS)

Wei, Y.; Liu, S.; Cook, R. B.; Post, W. M.; Huntzinger, D. N.; Schwalm, C.; Schaefer, K. M.; Jacobson, A. R.; Michalak, A. M.

2012-12-01

Terrestrial biogeochemistry modeling is a crucial component of carbon cycle research and provides unique capabilities to understand terrestrial ecosystems. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) aims to identify key differences in model formulation that drive observed differences in model predictions of biospheric carbon exchange. To do so, the MsTMIP framework provides standardized prescribed environmental driver data and a standard model protocol to facilitate comparisons of modeling results from nearly 30 teams. Model performance is then evaluated against a variety of carbon-cycle related observations (remote sensing, atmospheric, and flux tower-based observations) using quantitative performance measures and metrics in an integrated evaluation framework. As part of this effort, we have harmonized highly diverse and heterogeneous environmental driver data, model outputs, and observational benchmark data sets to facilitate use and analysis by the MsTMIP team. In this presentation, we will describe the lessons learned from this data-intensive carbon cycle research. The data harmonization activity itself can be made more efficient with the consideration of proper tools, version control, workflow management, and collaboration within the whole team. The adoption of on-demand and interoperable protocols (e.g. OPeNDAP and Open Geospatial Consortium) makes data visualization and distribution more flexible. Users can customize and download data in specific spatial extent, temporal period, and different resolutions. The effort to properly organize data in an open and standard format (e.g. Climate & Forecast compatible netCDF) allows the data to be analysed by a dispersed set of researchers more efficiently, and maximizes the longevity and utilization of the data. The lessons learned from this specific experience can benefit efforts by the broader community to leverage diverse data resources more efficiently in scientific research.

Loss of l(3)mbt leads to acquisition of the ping-pong cycle in Drosophila ovarian somatic cells

PubMed Central

Sumiyoshi, Tetsutaro; Sato, Kaoru; Yamamoto, Hitomi; Iwasaki, Yuka W.; Siomi, Haruhiko; Siomi, Mikiko C.

2016-01-01

In Drosophila germ cells, PIWI-interacting RNAs (piRNAs) are amplified through a PIWI slicer-dependent feed-forward loop termed the ping-pong cycle, yielding secondary piRNAs. However, the detailed mechanism remains poorly understood, largely because an ex vivo model system amenable to biochemical analyses has not been available. Here, we show that CRISPR-mediated loss of function of lethal (3) malignant brain tumor [l(3)mbt] leads to ectopic activation of the germ-specific ping-pong cycle in ovarian somatic cells. Perinuclear foci resembling nuage, the ping-pong center, appeared following l(3)mbt mutation. This activation of the ping-pong machinery in cultured cells will greatly facilitate elucidation of the mechanism underlying secondary piRNA biogenesis in Drosophila. PMID:27474440

A Synthesis of Solar Cycle Prediction Techniques

NASA Technical Reports Server (NTRS)

Hathaway, David H.; Wilson, Robert M.; Reichmann, Edwin J.

1999-01-01

A number of techniques currently in use for predicting solar activity on a solar cycle timescale are tested with historical data. Some techniques, e.g., regression and curve fitting, work well as solar activity approaches maximum and provide a month-by-month description of future activity, while others, e.g., geomagnetic precursors, work well near solar minimum but only provide an estimate of the amplitude of the cycle. A synthesis of different techniques is shown to provide a more accurate and useful forecast of solar cycle activity levels. A combination of two uncorrelated geomagnetic precursor techniques provides a more accurate prediction for the amplitude of a solar activity cycle at a time well before activity minimum. This combined precursor method gives a smoothed sunspot number maximum of 154 plus or minus 21 at the 95% level of confidence for the next cycle maximum. A mathematical function dependent on the time of cycle initiation and the cycle amplitude is used to describe the level of solar activity month by month for the next cycle. As the time of cycle maximum approaches a better estimate of the cycle activity is obtained by including the fit between previous activity levels and this function. This Combined Solar Cycle Activity Forecast gives, as of January 1999, a smoothed sunspot maximum of 146 plus or minus 20 at the 95% level of confidence for the next cycle maximum.

Is It Me or My Hormones? Neuroendocrine Activation Profiles to Visual Food Stimuli Across the Menstrual Cycle.

PubMed

Arnoni-Bauer, Yardena; Bick, Atira; Raz, Noa; Imbar, Tal; Amos, Shoshana; Agmon, Orly; Marko, Limor; Levin, Netta; Weiss, Ram

2017-09-01

Homeostatic energy balance is controlled via the hypothalamus, whereas regions controlling reward and cognitive decision-making are critical for hedonic eating. Eating varies across the menstrual cycle peaking at the midluteal phase. To test responses of females with regular cycles during midfollicular and midluteal phase and of users of monophasic oral contraception pills (OCPs) to visual food cues. Participants performed a functional magnetic resonance imaging while exposed to visual food cues in four time points: fasting and fed conditions in midfollicular and midluteal phases. Twenty females with regular cycles and 12 on monophasic OCP, aged 18 to 35 years. Activity in homeostatic (hypothalamus), reward (amygdala, putamen and insula), frontal (anterior cingulate cortex, dorsolateral prefrontal cortex), and visual regions (calcarine and lateral occipital cortex). Tertiary hospital. In females with regular cycles, brain regions associated with homeostasis but also the reward system, executive frontal areas, and afferent visual areas were activated to a greater degree during the luteal compared with the follicular phase. Within the visual areas, a dual effect of hormonal and prandial state was seen. In females on monophasic OCPs, characterized by a permanently elevated progesterone concentration, activity reminiscent of the luteal phase was found. Androgen, cortisol, testosterone, and insulin levels were significantly correlated with reward and visual region activation. Hormonal mechanisms affect the responses of women's homeostatic, emotional, and attentional brain regions to food cues. The relation of these findings to eating behavior throughout the cycle needs further investigation. Copyright © 2017 Endocrine Society

Inhibition of Krebs cycle and activation of glyoxylate cycle in the course of chronological aging of Saccharomyces cerevisiae. Compensatory role of succinate oxidation.

PubMed

Samokhvalov, V; Ignatov, V; Kondrashova, M

2004-01-01

We investigated oxidative processes in mitochondria of Saccharomyces cerevisiae grown on ethanol in the course of chronological aging. We elaborated a model of chronological aging that avoids the influence of exhaustion of medium, as well as the accumulation of toxic metabolites during aging. A decrease in total respiration of cells and, even more, of the contribution of respiration coupled with ATP-synthesis was observed during aging. Aging is also related with the decrease of the contribution of malonate-insensitive respiration. Activities of citrate-synthase (CS), alpha-ketoglutarate dehydrogenase (KGDH) and malate dehydrogenase (MDH) were threefold decreased. The activity of NADP-dependent isocitrate dehydrogenase (NADP-ICDH) decreased more significantly, while the activity of NAD-dependent isocitrate dehydrogenase (NAD-ICDH) fell even greater, being completely inactivated on the third week of aging. In contrast, succinate dehydrogenase (SDH), enzymes of glyoxylate cycle (GCL) (isocitrate lyase (ICL) and malate synthase (MLS)), and enzymes of ethanol oxidation (alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ACDH)), were activated by 50% or more. The behavior of oxidative enzymes and metabolic pathways are apparently inherent to a more viable, long-lived cells in population, selected in the course of chronological aging. This selection allows cells to reveal the mechanism of their higher viability as caused by shunting of complete Krebs cycle by glyoxylate cycle, with a concomitant increased rate of the most efficient energy source, namely succinate formation and oxidation. Thiobarbituric-reactive species (TAR species) increased during aging. We supposed that to be the immediate cause of damage of a part of yeast population. These data show that a greater succinate contribution to respiration in more active cells is a general property of yeast and animal tissues.

A novel quantitative model of cell cycle progression based on cyclin-dependent kinases activity and population balances.

PubMed

Pisu, Massimo; Concas, Alessandro; Cao, Giacomo

2015-04-01

Cell cycle regulates proliferative cell capacity under normal or pathologic conditions, and in general it governs all in vivo/in vitro cell growth and proliferation processes. Mathematical simulation by means of reliable and predictive models represents an important tool to interpret experiment results, to facilitate the definition of the optimal operating conditions for in vitro cultivation, or to predict the effect of a specific drug in normal/pathologic mammalian cells. Along these lines, a novel model of cell cycle progression is proposed in this work. Specifically, it is based on a population balance (PB) approach that allows one to quantitatively describe cell cycle progression through the different phases experienced by each cell of the entire population during its own life. The transition between two consecutive cell cycle phases is simulated by taking advantage of the biochemical kinetic model developed by Gérard and Goldbeter (2009) which involves cyclin-dependent kinases (CDKs) whose regulation is achieved through a variety of mechanisms that include association with cyclins and protein inhibitors, phosphorylation-dephosphorylation, and cyclin synthesis or degradation. This biochemical model properly describes the entire cell cycle of mammalian cells by maintaining a sufficient level of detail useful to identify check point for transition and to estimate phase duration required by PB. Specific examples are discussed to illustrate the ability of the proposed model to simulate the effect of drugs for in vitro trials of interest in oncology, regenerative medicine and tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

An involvement of yeast peroxisomal channels in transmembrane transfer of glyoxylate cycle intermediates.

PubMed

Antonenkov, Vasily D; Mindthoff, Sabrina; Grunau, Silke; Erdmann, Ralf; Hiltunen, J Kalervo

2009-12-01

The separate localization of glyoxylate cycle enzymes in the peroxisomes and the cytosol of the yeast Saccharomyces cerevisiae indicates that the peroxisomal membrane must permit the flow of metabolites between the two compartments. The transfer of these metabolites may require peroxisomal membrane channel(s). We used an electrophysiological approach (reconstitution assay in lipid bilayers) to assess the ability of peroxisomal membrane channels to conduct different solutes including metabolites of the glyoxylate cycle. At least two distinct channel-forming activities were detected in peroxisomal preparations. One of these activities was highly inducible by dithiothreitol and showed large-amplitude current increments when 1M KCl was used as a bath solution. Single-channel analysis revealed that the inducible channel is anion-selective (P(Cl(-)) / P(K(+)) = 2.6; P(citrate)/P(K(+)) = 1.6) and displays flickering at holding potentials over + or - 30mV directed upward or downward relative to the main open state of the channel. The channel inducible by DTT facilitates the transfer of solutes with a molecular mass up to 400Da, sufficient to allow the transmembrane trafficking of glyoxylate cycle intermediates between the peroxisomal lumen and the cytoplasm.

With a little help from my goals: integrating intergoal facilitation with the theory of planned behaviour to predict physical activity.

PubMed

Presseau, Justin; Sniehotta, Falko F; Francis, Jill J; Gebhardt, Winifred A

2010-11-01

Integration of a multiple goal theory approach into the theory of planned behaviour (TPB) to investigate how the perceived facilitating and conflicting relationships in multiple goal pursuit predict performance of a health-related behaviour. Prospective design with 8-week follow-up. At baseline, perceived intergoal facilitation and intergoal conflict were measured using personal projects analysis supplemented with standard TPB measures for physical activity (PA). Self-reported PA was measured at follow-up 8 weeks later. N=137 participants completed measures at both time points (55.4% response rate at follow-up). Hierarchical regression showed that perceived intergoal facilitation, but not intergoal conflict, directly predicted PA beyond intention and perceived behavioural control (PBC), accounting for more than 4% of additional variance in PA. Intergoal facilitation had an indirect effect on intention through attitude and PBC, and intention partially mediated the effect of intergoal facilitation on behaviour. The perceived facilitating effect of pursuing other personal goals predicts the performance of a health-related behaviour over and above single behaviour-focused social cognitions.

The maintenance of elevated active chlorine levels in the Antarctic lower stratosphere through HCl null cycles

NASA Astrophysics Data System (ADS)

Müller, Rolf; Grooß, Jens-Uwe; Mannan Zafar, Abdul; Robrecht, Sabine; Lehmann, Ralph

2018-03-01

The Antarctic ozone hole arises from ozone destruction driven by elevated levels of ozone destroying (active) chlorine in Antarctic spring. These elevated levels of active chlorine have to be formed first and then maintained throughout the period of ozone destruction. It is a matter of debate how this maintenance of active chlorine is brought about in Antarctic spring, when the rate of formation of HCl (considered to be the main chlorine deactivation mechanism in Antarctica) is extremely high. Here we show that in the heart of the ozone hole (16-18 km or 85-55 hPa, in the core of the vortex), high levels of active chlorine are maintained by effective chemical cycles (referred to as HCl null cycles hereafter). In these cycles, the formation of HCl is balanced by immediate reactivation, i.e. by immediate reformation of active chlorine. Under these conditions, polar stratospheric clouds sequester HNO3 and thereby cause NO2 concentrations to be low. These HCl null cycles allow active chlorine levels to be maintained in the Antarctic lower stratosphere and thus rapid ozone destruction to occur. For the observed almost complete activation of stratospheric chlorine in the lower stratosphere, the heterogeneous reaction HCl + HOCl is essential; the production of HOCl occurs via HO2 + ClO, with the HO2 resulting from CH2O photolysis. These results are important for assessing the impact of changes of the future stratospheric composition on the recovery of the ozone hole. Our simulations indicate that, in the lower stratosphere, future increased methane concentrations will not lead to enhanced chlorine deactivation (through the reaction CH4 + Cl → HCl + CH3) and that extreme ozone destruction to levels below ≈ 0.1 ppm will occur until mid-century.

Determinants of sports, cycling, walking and overall leisure-time physical activity among postmenopausal women in Germany.

PubMed

Steindorf, Karen; Chang-Claude, Jenny; Flesch-Janys, Dieter; Schmidt, Martina E

2010-11-01

Convincing evidence exists for a beneficial effect of physical activity (PA) on health and well-being for elderly women. Nevertheless, many women in Germany are insufficiently physically active. Activity promotion programmes should target women in particular need. Thus, we examined subject-related determinants of PA for postmenopausal women in Germany. Associations of sociodemographic, anthropometric, lifestyle and health-related factors with activity since the age of 50 years were assessed with multiple linear and logistic regression models, regarding overall leisure-time PA (LPA) in metabolic equivalent hours per week, engagement in sports (ever v. never), cycling (yes v. no) and walking (≥3·5 v. <3·5 h/week). All controls from a population-based case-control study carried out in 2002-2005 in Germany (MARIE study). A total of 6569 postmenopausal women. We found significant associations of overall LPA, sports, cycling and walking in postmenopausal years with several characteristics, among others: obese v. normal BMI (adjusted OR: ORsports = 0·73; ORcycling = 0·60; ORwalking = 0·63), tall v. short (ORsports = 1·49), worker v. medium employee (ORsports = 0·47), working full time v. unemployed/retired (ORsports = 0·80; ORwalking = 0·56), current v. non-smoker (ORsports = 0·62; ORcycling = 0·62; ORwalking = 0·82), non-German nationality (ORsports = 0·58; ORcycling = 0·41). Parity seemed more relevant than marital status for sports or cycling activity. Further, CVD, hypertension and diabetes were significantly associated with lower activity (ORsports = 0·77, 0·79 and 0·80; ORcycling = 0·80, 0·75 and 0·85, respectively). Our results suggest potential target groups for promoting sports, cycling or walking activity. Postmenopausal women with chronic diseases may need to be stronger encouraged by their physicians to engage in adequate PA for the management of their diseases.

LIFE CYCLE ASSESSMENT: INVENTORY GUIDELINES AND PRINCIPLES

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) is describing the process, the underlying data, and the Inherent assumptions Involved in conducting the Inventory component of a life-cycle assessment (LCA) In order to facilitate understanding by potential users. This Inventory...

The impacts of climate change and human activities on biogeochemical cycles on the Qinghai-Tibetan Plateau.

PubMed

Chen, Huai; Zhu, Qiuan; Peng, Changhui; Wu, Ning; Wang, Yanfen; Fang, Xiuqing; Gao, Yongheng; Zhu, Dan; Yang, Gang; Tian, Jianqing; Kang, Xiaoming; Piao, Shilong; Ouyang, Hua; Xiang, Wenhua; Luo, Zhibin; Jiang, Hong; Song, Xingzhang; Zhang, Yao; Yu, Guirui; Zhao, Xinquan; Gong, Peng; Yao, Tandong; Wu, Jianghua

2013-10-01

With a pace of about twice the observed rate of global warming, the temperature on the Qinghai-Tibetan Plateau (Earth's 'third pole') has increased by 0.2 °C per decade over the past 50 years, which results in significant permafrost thawing and glacier retreat. Our review suggested that warming enhanced net primary production and soil respiration, decreased methane (CH(4)) emissions from wetlands and increased CH(4) consumption of meadows, but might increase CH(4) emissions from lakes. Warming-induced permafrost thawing and glaciers melting would also result in substantial emission of old carbon dioxide (CO(2)) and CH(4). Nitrous oxide (N(2)O) emission was not stimulated by warming itself, but might be slightly enhanced by wetting. However, there are many uncertainties in such biogeochemical cycles under climate change. Human activities (e.g. grazing, land cover changes) further modified the biogeochemical cycles and amplified such uncertainties on the plateau. If the projected warming and wetting continues, the future biogeochemical cycles will be more complicated. So facing research in this field is an ongoing challenge of integrating field observations with process-based ecosystem models to predict the impacts of future climate change and human activities at various temporal and spatial scales. To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus biogeochemical cycles as well as about the role of microbes in these cycles. © 2013 John Wiley & Sons Ltd.

Evaluating the role of sulfur and hyporheic exchange in biogeochemical cycling in riparian wetlands

NASA Astrophysics Data System (ADS)

Ng, G. H. C.; O'Hara, P. A.; Santelli, C. M.; Rosenfeld, C.; Yourd, A.

2017-12-01

Although the mixing of surface water and groundwater is well-recognized to support hotspots of redox activities such as denitrification, few hyporheic zone studies have examined sulfur reactions. Because sulfate concentrations in wetlands, lake beds, and stream beds are low compared to in marine settings, the hierarchical redox tower dictates that sulfate reduction should play a substantially lesser role in biogeochemical cycling than nitrate or iron reduction when these sediments become anoxic. However, recent experiments challenge the classically held redox sequence by revealing "cryptic" sulfur cycling that can support unexpectedly high sulfate reduction rates and could be driving iron and carbon cycling through coupled reactions. Sulfur biogeochemical processes remain poorly understood in field settings, where little is known about the impact of hydrologic fluxes. Our study examines how hyporheic flux can "kick" forward cryptic sulfur cycling and related iron and carbon reactions by perturbing geochemical gradients to which microbial communities respond. We evaluate field-scale cycling of iron, sulfur, and carbon through a combination of hydrologic monitoring, microbial and geochemical analyses, and reactive-transport modeling at a riparian wetland site in northeastern Minnesota that is impacted by mining practices. In particular, we assess how varying fluxes between high sulfate concentration surface water and lower sulfate concentration groundwater over a season could be (1) facilitating intensified sulfur cycling coupled to abiotic iron reduction and (2) altering methane release possibly through anaerobic methane oxidation. Our findings can help clarify the importance of sulfur in non-marine biogeochemical cycling and provide better understanding of how anthropogenic activities can impact critical freshwater systems.

Facilitative glucose transporter Glut1 is actively excluded from rod outer segments.

PubMed

Gospe, Sidney M; Baker, Sheila A; Arshavsky, Vadim Y

2010-11-01

Photoreceptors are among the most metabolically active cells in the body, relying on both oxidative phosphorylation and glycolysis to satisfy their high energy needs. Local glycolysis is thought to be particularly crucial in supporting the function of the photoreceptor's light-sensitive outer segment compartment, which is devoid of mitochondria. Accordingly, it has been commonly accepted that the facilitative glucose transporter Glut1 responsible for glucose entry into photoreceptors is localized in part to the outer segment plasma membrane. However, we now demonstrate that Glut1 is entirely absent from the rod outer segment and is actively excluded from this compartment by targeting information present in its cytosolic C-terminal tail. Our data indicate that glucose metabolized in the outer segment must first enter through other parts of the photoreceptor cell. Consequently, the entire energy supply of the outer segment is dependent on diffusion of energy-rich substrates through the thin connecting cilium that links this compartment to the rest of the cell.

CHANGES OF THE SOLAR MERIDIONAL VELOCITY PROFILE DURING CYCLE 23 EXPLAINED BY FLOWS TOWARD THE ACTIVITY BELTS

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

Cameron, R. H.; Schuessler, M., E-mail: cameron@mps.mpg.d

The solar meridional flow is an important ingredient in Babcock-Leighton type models of the solar dynamo. Global variations of this flow have been suggested to explain the variations in the amplitudes and lengths of the activity cycles. Recently, cycle-related variations in the amplitude of the P{sup 1}{sub 2} term in the Legendre decomposition of the observed meridional flow have been reported. The result is often interpreted in terms of an overall variation in the flow amplitude during the activity cycle. Using a semi-empirical model based upon the observed distribution of magnetic flux on the solar surface, we show that themore » reported variations of the P{sup 1}{sub 2} term can be explained by the observed localized inflows into the active region belts. No variation of the overall meridional flow amplitude is required.« less

Brown adipose tissue thermogenesis, the basic rest-activity cycle, meal initiation, and bodily homeostasis in rats.

PubMed

Blessing, William; Mohammed, Mazher; Ootsuka, Youichirou

2013-09-10

Laboratory rats alternate between behaviorally active and inactive states every 1-2h throughout the 24hour day, the ultradian basic rest-activity cycle (BRAC). During the behaviorally active phases of the BRAC, brown adipose tissue (BAT) temperature, body and brain temperature, and arterial pressure and heart rate increase in an integrated manner. Since the BAT temperature increases are substantially greater than the corresponding body and brain temperature increases, BAT thermogenesis contributes to the body and brain temperature increases. When food is available ad libitum, eating commences approximately 15min after the onset of an episodic increase in BAT temperature, and not at other times. If no food is available, the rat still disturbs the empty food container approximately 15min after the onset of an episodic increase in BAT temperature, and not at other times. The increase in brain temperature that precedes eating may facilitate the cognitive processing that occurs during the search for food, when the rat engages with the external environment. Rather than being triggered by changes in levels of body fuels or other meal-associated factors, in sedentary laboratory rats with ad libitum access to food, meal initiation normally occurs as part of the centrally-programmed ultradian BRAC. BRAC-associated BAT temperature increases occur in a thermoneutral environment and they are not preceded by falls in body or brain temperature, so they are not homeostatic thermoregulatory responses. The pattern of integrated behaviors and physiological functions associated with the BRAC presumably reflects Darwinian natural selection, and homeostatic thermoregulatory explanations of the BRAC-associated changes in temperature should be considered in this context. Copyright © 2013 Elsevier Inc. All rights reserved.

Mg II Chromospheric Emission Line Bisectors Of HD39801 And Its Relation With The Activity Cycle

NASA Astrophysics Data System (ADS)

García García, Leonardo Enrique; Pérez Martínez, M. Isabel

2016-07-01

Betelgeuse is a cool star of spectral type M and luminosity class I. In the present work, the activity cycle of Betelgeuse was obtained from the integrated emission flux of the Mg II H and K lines, using more than 250 spectra taken from the International Ultraviolet Explorer (IUE) online database. Of which it was found, based on a Lomb Scargle periodogram, a cycle of 16 years, along with 2 sub-cycles with a period of the order of 0.60 and 0.65 years, which may be due to turbulence or possible stellar flares. In addition, an analysis of line asymmetry was made by means of the chromospheric emission line bisectors, due to the strong self-absorption observed in this lines, the blue and red wings were analyzed independently. In order to measure such asymmetry, a "line shift" was calculated, from which several cycles of variability were obtained from a Lomb Scargle periodogram, spanning from few months to 4 years. In the sense, the most significant cycle is about 0.44 and 0.33 years in the blue and red wing respectively. It is worth noting, that the rotation period of the star doesn't play an important role in the variability of the Mg II lines. This technique provides us with a new way to study activity cycles of evolved stars.

Cell Cycle Deregulation in Ewing's Sarcoma Pathogenesis

PubMed Central

Kowalewski, Ashley A.; Randall, R. Lor; Lessnick, Stephen L.

2011-01-01

Ewing's sarcoma is a highly aggressive pediatric tumor of bone that usually contains the characteristic chromosomal translocation t(11;22)(q24;q12). This translocation encodes the oncogenic fusion protein EWS/FLI, which acts as an aberrant transcription factor to deregulate target genes necessary for oncogenesis. One key feature of oncogenic transformation is dysregulation of cell cycle control. It is therefore likely that EWS/FLI and other cooperating mutations in Ewing's sarcoma modulate the cell cycle to facilitate tumorigenesis. This paper will summarize current published data associated with deregulation of the cell cycle in Ewing's sarcoma and highlight important questions that remain to be answered. PMID:21052502

Can FES-Augmented Active Cycling Training Improve Locomotion in Post-Acute Elderly Stroke Patients?

PubMed

Peri, Elisabetta; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Nava, Claudia; Longoni, Valentina; Monticone, Marco; Ferrante, Simona

2016-06-13

Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only). This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results.

Facilitating Transfer in College Reading Programs.

ERIC Educational Resources Information Center

Nist, Sherrie; Simpson, Michele L.

1987-01-01

Gives three activities--journal writing, microteaching partners, and the PLAE model (planning, listing, activating, and evaluating)--that can facilitate learner independence and transfer of efficient and effective study strategies in college developmental reading programs. (NKA)

Language Mediated Concept Activation in Bilingual Memory Facilitates Cognitive Flexibility

PubMed Central

Kharkhurin, Anatoliy V.

2017-01-01

This is the first attempt of empirical investigation of language mediated concept activation (LMCA) in bilingual memory as a cognitive mechanism facilitating divergent thinking. Russian–English bilingual and Russian monolingual college students were tested on a battery of tests including among others Abbreviated Torrance Tests for Adults assessing divergent thinking traits and translingual priming (TLP) test assessing the LMCA. The latter was designed as a lexical decision priming test, in which a prime and a target were not related in Russian (language of testing), but were related through their translation equivalents in English (spoken only by bilinguals). Bilinguals outperformed their monolingual counterparts on divergent thinking trait of cognitive flexibility, and bilinguals’ performance on this trait could be explained by their TLP effect. Age of second language acquisition and proficiency in this language were found to relate to the TLP effect, and therefore were proposed to influence the directionality and strength of connections in bilingual memory. PMID:28701981

Sports participation after rehabilitation: Barriers and facilitators.

PubMed

Jaarsma, Eva A; Dekker, Rienk; Geertzen, Jan H B; Dijkstra, Pieter U

2016-01-01

To analyse barriers to, and facilitators of, sports participation among people with physical disabilities after rehabilitation and to compare differences between inactive and active participants regarding these experienced barriers and facilitators. Participants were 1,223 adults (mean age 51.6 years, standard deviation 15.1 years) treated in the Rehabilitation Centre of the University Medical Center Groningen, who completed a questionnaire. The questionnaire consisted of a self-constructed questionnaire regarding barriers and facilitators. Fifty-eight percent of the participants were active in sports after their rehabilitation. Younger age and a higher level of education were positively associated with sports participation, whereas using assistive devices and experiencing environmental barriers were negatively associated. Facilitators of sports participation were health, fun and increasing physical strength, and advice from rehabilitation professionals. Rehabilitation professionals should emphasize the health benefits of, and enjoyment from, sports participation for people with physical disabilities. They should repeatedly remind people with physical disabilities to stay/become active after completing their rehabilitation programme. Rehabilitation professionals should also provide information about strategies to reduce environmental barriers to sports participation, which could help people using assistive devices to overcome these barriers.

Managing Data and Facilitating Science: A spectrum of activities in the Centre for Environmental Data Archival. (Invited)

NASA Astrophysics Data System (ADS)

Lawrence, B.; Bennett, V.; Callaghan, S.; Juckes, M. N.; Pepler, S.

2013-12-01

The UK Centre for Environmental Data Archival (CEDA) hosts a number of formal data centres, including the British Atmospheric Data Centre (BADC), and is a partner in a range of national and international data federations, including the InfraStructure for the European Network for Earth system Simulation, the Earth System Grid Federation, and the distributed IPCC Data Distribution Centres. The mission of CEDA is to formally curate data from, and facilitate the doing of, environmental science. The twin aims are symbiotic: data curation helps facilitate science, and facilitating science helps with data curation. Here we cover how CEDA delivers this strategy by established internal processes supplemented by short-term projects, supported by staff with a range of roles. We show how CEDA adds value to data in the curated archive, and how it supports science, and show examples of the aforementioned symbiosis. We begin by discussing curation: CEDA has the formal responsibility for curating the data products of atmospheric science and earth observation research funded by the UK Natural Environment Research Council (NERC). However, curation is not just about the provider community, the consumer communities matter too, and the consumers of these data cross the boundaries of science, including engineers, medics, as well as the gamut of the environmental sciences. There is a small, and growing cohort of non-science users. For both producers and consumers of data, information about data is crucial, and a range of CEDA staff have long worked on tools and techniques for creating, managing, and delivering metadata (as well as data). CEDA "science support" staff work with scientists to help them prepare and document data for curation. As one of a spectrum of activities, CEDA has worked on data Publication as a method of both adding value to some data, and rewarding the effort put into the production of quality datasets. As such, we see this activity as both a curation and a

Practice-tailored facilitation to improve pediatric preventive care delivery: a randomized trial.

PubMed

Meropol, Sharon B; Schiltz, Nicholas K; Sattar, Abdus; Stange, Kurt C; Nevar, Ann H; Davey, Christina; Ferretti, Gerald A; Howell, Diana E; Strosaker, Robyn; Vavrek, Pamela; Bader, Samantha; Ruhe, Mary C; Cuttler, Leona

2014-06-01

Evolving primary care models require methods to help practices achieve quality standards. This study assessed the effectiveness of a Practice-Tailored Facilitation Intervention for improving delivery of 3 pediatric preventive services. In this cluster-randomized trial, a practice facilitator implemented practice-tailored rapid-cycle feedback/change strategies for improving obesity screening/counseling, lead screening, and dental fluoride varnish application. Thirty practices were randomized to Early or Late Intervention, and outcomes assessed for 16 419 well-child visits. A multidisciplinary team characterized facilitation processes by using comparative case study methods. Baseline performance was as follows: for Obesity: 3.5% successful performance in Early and 6.3% in Late practices, P = .74; Lead: 62.2% and 77.8% success, respectively, P = .11; and Fluoride: <0.1% success for all practices. Four months after randomization, performance rose in Early practices, to 82.8% for Obesity, 86.3% for Lead, and 89.1% for Fluoride, all P < .001 for improvement compared with Late practices' control time. During the full 6-month intervention, care improved versus baseline in all practices, for Obesity for Early practices to 86.5%, and for Late practices 88.9%; for Lead for Early practices to 87.5% and Late practices 94.5%; and for Fluoride, for Early practices to 78.9% and Late practices 81.9%, all P < .001 compared with baseline. Improvements were sustained 2 months after intervention. Successful facilitation involved multidisciplinary support, rapid-cycle problem solving feedback, and ongoing relationship-building, allowing individualizing facilitation approach and intensity based on 3 levels of practice need. Practice-tailored Facilitation Intervention can lead to substantial, simultaneous, and sustained improvements in 3 domains, and holds promise as a broad-based method to advance pediatric preventive care. Copyright © 2014 by the American Academy of Pediatrics.

Practice-Tailored Facilitation to Improve Pediatric Preventive Care Delivery: A Randomized Trial

PubMed Central

Schiltz, Nicholas K.; Sattar, Abdus; Stange, Kurt C.; Nevar, Ann H.; Davey, Christina; Ferretti, Gerald A.; Howell, Diana E.; Strosaker, Robyn; Vavrek, Pamela; Bader, Samantha; Ruhe, Mary C.; Cuttler, Leona

2014-01-01

OBJECTIVE: Evolving primary care models require methods to help practices achieve quality standards. This study assessed the effectiveness of a Practice-Tailored Facilitation Intervention for improving delivery of 3 pediatric preventive services. METHODS: In this cluster-randomized trial, a practice facilitator implemented practice-tailored rapid-cycle feedback/change strategies for improving obesity screening/counseling, lead screening, and dental fluoride varnish application. Thirty practices were randomized to Early or Late Intervention, and outcomes assessed for 16 419 well-child visits. A multidisciplinary team characterized facilitation processes by using comparative case study methods. RESULTS: Baseline performance was as follows: for Obesity: 3.5% successful performance in Early and 6.3% in Late practices, P = .74; Lead: 62.2% and 77.8% success, respectively, P = .11; and Fluoride: <0.1% success for all practices. Four months after randomization, performance rose in Early practices, to 82.8% for Obesity, 86.3% for Lead, and 89.1% for Fluoride, all P < .001 for improvement compared with Late practices’ control time. During the full 6-month intervention, care improved versus baseline in all practices, for Obesity for Early practices to 86.5%, and for Late practices 88.9%; for Lead for Early practices to 87.5% and Late practices 94.5%; and for Fluoride, for Early practices to 78.9% and Late practices 81.9%, all P < .001 compared with baseline. Improvements were sustained 2 months after intervention. Successful facilitation involved multidisciplinary support, rapid-cycle problem solving feedback, and ongoing relationship-building, allowing individualizing facilitation approach and intensity based on 3 levels of practice need. CONCLUSIONS: Practice-tailored Facilitation Intervention can lead to substantial, simultaneous, and sustained improvements in 3 domains, and holds promise as a broad-based method to advance pediatric preventive care. PMID:24799539

An exploration of barriers and facilitators to older adults' participation in higher impact physical activity and bone health: a qualitative study.

PubMed

Simmonds, B A J; Hannam, K J; Fox, K R; Tobias, J H

2016-03-01

This qualitative study explored the acceptability of high-impact physical activity for increasing bone strength in later life. Thematic analysis established the barriers and facilitators to this physical activity. They prioritised joint over skeletal health, of which they had little concept. Interventions need to clearly communicate the rationale and benefits. The aim of this study was to explore the acceptability of doing high-impact physical activity in later life. This qualitative study was embedded within a large-scale observational study and was designed to address specific objectives and feed into a subsequent intervention. Five focus groups with physically active men and women (over 50 years) were used to develop an interview topic guide to explore the acceptability of high-impact physical activity in older men and women (over 65 years) in South West England. A total of 28 semi-structured interviews with 31 participants were then conducted and transcripts analysed thematically. Three main barriers emerged: conceptualising bone, damage to joints and falling/safety concerns. Two main facilitators were also identified: the need to understand clear tangible benefits and incorporation of activity into everyday habits. Older adults were interested how high-impact physical activity would help to maintain their mobility, independence or social relationships. Some participants wanted tangible feedback from accelerometers, health care professionals and/or bone scans in order to develop a more intimate knowledge of their bone health. Interventions incorporating high-impact physical activity for older adults need to communicate how this activity can impact more broadly on health and lives; that physical activity will be safe, beneficial and not damaging to their joints will need to be clearly conveyed. Ways in which high-impact physical activity can be habitualised into everyday activities, be fun and interactive may help facilitate longer term adoption.

The Fantastic Facilitator: Engaging Activities for Leading Groups.

ERIC Educational Resources Information Center

Duttweiler, Patricia Cloud

This document is designed to help facilitators with the formation and development of effective teams of people who have no previous history as a team and no training in group processes. Part 1 provides a narrative explanation of the stages of group development (investing in membership, forming attachments to subgroups, confronting/debating issues,…

Solar magnetic cycle

NASA Technical Reports Server (NTRS)

Harvey, Karen L.

1993-01-01

Using NSO/KP magnetograms, the pattern and rate of the emergence of magnetic flux and the development of the large-scale patterns of unipolar fields are considered in terms of the solar magnetic cycle. Magnetic flux emerges in active regions at an average rate of 2 x 10(exp 21) Mx/day, approximately 10 times the estimated rate in ephemeral regions. Observations are presented that demonstrate that the large-scale unipolar fields originate in active regions and activity nests. For cycle 21, the net contribution of ephemeral regions to the axial dipole moment of the Sun is positive, and is of opposite sign to that of active regions. Its amplitude is smaller by a factor of 6, assuming an average lifetime of ephemeral regions of 8 hours. Active regions larger than 4500 Mm(sup 2) are the primary contributor to the cycle variation of Sun's axial dipole moment.

Online interprofessional education facilitation: A scoping review.

PubMed

Evans, Sherryn Maree; Ward, Catherine; Reeves, Scott

2018-04-22

The use of online media to deliver interprofessional education (IPE) is becoming more prevalent across health professions education settings. Facilitation of IPE activities is known to be critical to the effective delivery of IPE, however, specifics about the nature of online IPE facilitation remains unclear. To explore the health professions education literature to understand the extent, range and nature of research on online IPE facilitation. Scoping review methodology was used to guide a search of four electronic databases for relevant papers. Of the 2095 abstracts initially identified, after screening of both abstracts and full-text papers, 10 studies were selected for inclusion in this review. Following abstraction of key information from each study, a thematic analysis was undertaken. Three key themes emerged to describe the nature of the IPE facilitation literature: (1) types of online IPE facilitation contributions, (2) the experience of online IPE facilitation and (3) personal outcomes of online IPE facilitation. These IPE facilitation themes were particularly focused on facilitation of interprofessional student teams on an asynchronous basis. While the included studies provide some insight into the nature of online IPE facilitation, future research is needed to better understand facilitator contributions, and the facilitation experience and associated outcomes, both relating to synchronous and asynchronous online environments.

Facilitator training program: The Université Laval Interprofessional Initiative.

PubMed

Milot, Élise; Museux, Anne-Claire; Careau, Emmanuelle

2017-03-01

A facilitator training program (FTP) for interprofessional learning (IPL) facilitators has been developed at Université Laval. This article describes the impacts of this program as perceived by the 22 IPL facilitators involved and outlines recommendations. Two qualitative data collection strategies were used to document the facilitators' pedagogical needs and views of the program's impacts. Results suggest that the FTP's pedagogical approach was effective. The IPL facilitators became more aware of their challenges and identified concrete strategies to use. Training initiatives should equip IPL facilitators to cope with uncertainty, create a climate supporting active learning, and facilitate positive interactions between students.

Spatial and temporal characterization of endometrial mesenchymal stem-like cells activity during the menstrual cycle

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

Shan, Xu; Chan, Rachel W.S., E-mail: rwschan@hku.hk; Centre of Reproduction, Development of Growth, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR

The human endometrium is a highly dynamic tissue with the ability to cyclically regenerate during the reproductive life. Endometrial mesenchymal stem-like cells (eMSCs) located throughout the endometrium have shown to functionally contribute to endometrial regeneration. In this study we examine whether the menstrual cycle stage and the location in the endometrial bilayer (superficial and deep portions of the endometrium) has an effect on stem cell activities of eMSCs (CD140b{sup +}CD146{sup +} cells). Here we show the percentage and clonogenic ability of eMSCs were constant in the various stages of the menstrual cycle (menstrual, proliferative and secretory). However, eMSCs from themore » menstrual endometrium underwent significantly more rounds of self-renewal and enabled a greater total cell output than those from the secretory phase. Significantly more eMSCs were detected in the deeper portion of the endometrium compared to the superficial layer but their clonogenic and self-renewal activities remained similar. Our findings suggest that eMSCs are activated in the menstrual phase for the cyclical regeneration of the endometrium. - Highlights: • The percentages of endometrial mesenchymal-like stem cells (eMSCs) were constant across the menstrual cycle. • Menstruation eMSCs display superior self-renewal and long-term proliferative activities. • More eMSCs reside in the deeper portion of the endometrium than the superficial layer.« less

Can FES-Augmented Active Cycling Training Improve Locomotion in Post-Acute Elderly Stroke Patients?

PubMed Central

Peri, Elisabetta; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Nava, Claudia; Longoni, Valentina; Monticone, Marco; Ferrante, Simona

2016-01-01

Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only). This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results. PMID:27990234

Caring and Sharing: Becoming a Peer Facilitator.

ERIC Educational Resources Information Center

Myrick, Robert D.; Erney, Tom

This book contains information and skill-building activities designed to train adolescents as peer facilitators. The first chapter describes peer facilitation and provides an overview of the book. The second chapter discusses principles, concepts, and ideas to help better understand how people learn, make decisions, change, and develop their own…

Study the gradient characteristics of the ionosphere at equatorial latitude during the latest cycle of solar activity

NASA Astrophysics Data System (ADS)

Nguyen Thai, Chinh; Temitope Seun, Oluwadare; Le Thi, Nhung; Schuh, Harald

2017-04-01

The sun has its own seasons with an average duration of about 11 years. In this time, the sun enters a period of increased activity called the solar maximum and a period of decreased activity called the solar minimum. Cycles span from one minimum to the next. The current solar cycle is 24, which began on January 4, 2008 and is expected to be ended in 2019. During this period, the ionosphere changes its thickness and its characteristics as well. The change is most complicated and unpredictable at the equatorial latitudes in a band around 150 northward and 150 southward from the equator. Thailand is located in these regions is known as one of the countries most affected by the ionosphere change. Ionospheric information such as the vertical total electron content (VTEC) and scintillation indices can be extracted from the measurements of GNSS dual-frequency receivers. In this study, a Matlab tool is programmed to calculate some ionosphere parameters from the normal RINEX observation file including VTEC value, amplitude scintillation S4 index and others. The value of VTEC at one IGS station in Thailand (13.740N, 100.530E) is computed for almost one full solar cycle, that is 8 years, from 2009 to 2016. From these results, we are able to derive the rules of TEC variation over time and its dependence on solar activity in the equatorial regions. The change of VTEC is estimated in diurnal, seasonal and annual variation for the latest solar cycle. The solar cycle can be represented in several ways, in this paper we use the sunspot number and the F10.7 cm radio flux to describe the solar activity. The correlation coefficients between these solar indices and the monthly maximum of VTEC value are around 0.87, this indicates a high dependence of the ionosphere on solar activity. Besides, a scintillation map derived from GNSS data is displayed to indicate the intensity of scintillation activity.

In vivo monitoring of urea cycle activity with (13)C-acetate as a tracer of ureagenesis.

PubMed

Opladen, Thomas; Lindner, Martin; Das, Anibh M; Marquardt, Thorsten; Khan, Aneal; Emre, Sukru H; Burton, Barbara K; Barshop, Bruce A; Böhm, Thea; Meyburg, Jochen; Zangerl, Kathrin; Mayorandan, Sebene; Burgard, Peter; Dürr, Ulrich H N; Rosenkranz, Bernd; Rennecke, Jörg; Derbinski, Jens; Yudkoff, Marc; Hoffmann, Georg F

2016-01-01

The hepatic urea cycle is the main metabolic pathway for detoxification of ammonia. Inborn errors of urea cycle function present with severe hyperammonemia and a high case fatality rate. Long-term prognosis depends on the residual activity of the defective enzyme. A reliable method to estimate urea cycle activity in-vivo does not exist yet. The aim of this study was to evaluate a practical method to quantify (13)C-urea production as a marker for urea cycle function in healthy subjects, patients with confirmed urea cycle defect (UCD) and asymptomatic carriers of UCD mutations. (13)C-labeled sodium acetate was applied orally in a single dose to 47 subjects (10 healthy subjects, 28 symptomatic patients, 9 asymptomatic carriers). The oral (13)C-ureagenesis assay is a safe method. While healthy subjects and asymptomatic carriers did not differ with regards to kinetic variables for urea cycle flux, symptomatic patients had lower (13)C-plasma urea levels. Although the (13)C-ureagenesis assay revealed no significant differences between individual urea cycle enzyme defects, it reflected the heterogeneity between different clinical subgroups, including male neonatal onset ornithine carbamoyltransferase deficiency. Applying the (13)C-urea area under the curve can differentiate between severe from more mildly affected neonates. Late onset patients differ significantly from neonates, carriers and healthy subjects. This study evaluated the oral (13)C-ureagenesis assay as a sensitive in-vivo measure for ureagenesis capacity. The assay has the potential to become a reliable tool to differentiate UCD patient subgroups, follow changes in ureagenesis capacity and could be helpful in monitoring novel therapies of UCD. Copyright © 2015 Elsevier Inc. All rights reserved.

Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

PubMed Central

Pearcey, Gregory E. P.; Noble, Steven A.; Munro, Bridget; Zehr, E. Paul

2017-01-01

Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM), sprints with sensory stimulation (SPRINT + STIM) and sprints without stimulation (SPRINT). Seven participants also performed a fourth session (CONTROL), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared to

Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

PubMed

Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

2017-01-01

Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

A NEW SIMPLE DYNAMO MODEL FOR STELLAR ACTIVITY CYCLE

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

Yokoi, N.; Hamba, F.; Schmitt, D.

2016-06-20

A new simple dynamo model for stellar activity cycle is proposed. By considering an inhomogeneous flow effect on turbulence, it is shown that turbulent cross helicity (velocity–magnetic-field correlation) enters the expression of turbulent electromotive force as the coupling coefficient for the mean absolute vorticity. This makes the present model different from the current α –Ω-type models in two main ways. First, in addition to the usual helicity ( α ) and turbulent magnetic diffusivity ( β ) effects, we consider the cross-helicity effect as a key ingredient of the dynamo process. Second, the spatiotemporal evolution of cross helicity is solvedmore » simultaneously with the mean magnetic fields. The basic scenario is as follows. In the presence of turbulent cross helicity, the toroidal field is induced by the toroidal rotation. Then, as in usual models, the α effect generates the poloidal field from the toroidal one. This induced poloidal field produces a turbulent cross helicity whose sign is opposite to the original one (negative production). With this cross helicity of the reversed sign, a reversal in field configuration starts. Eigenvalue analyses of the simplest possible model give a butterfly diagram, which confirms the above scenario and the equatorward migrations, the phase relationship between the cross helicity and magnetic fields. These results suggest that the oscillation of the turbulent cross helicity is a key for the activity cycle. The reversal of the cross helicity is not the result of the magnetic-field reversal, but the cause of the latter. This new model is expected to open up the possibility of the mean-field or turbulence closure dynamo approaches.« less

Barriers, facilitators and preferences for the physical activity of school children. Rationale and methods of a mixed study

PubMed Central

2012-01-01

Background Physical activity interventions in schools environment seem to have shown some effectiveness in the control of the current obesity epidemic in children. However the complexity of behaviors and the diversity of influences related to this problem suggest that we urgently need new lines of insight about how to support comprehensive population strategies of intervention. The aim of this study was to know the perceptions of the children from Cuenca, about their environmental barriers, facilitators and preferences for physical activity. Methods/Design We used a mixed-method design by combining two qualitative methods (analysis of individual drawings and focus groups) together with the quantitative measurement of physical activity through accelerometers, in a theoretical sample of 121 children aged 9 and 11 years of schools in the province of Cuenca, Spain. Conclusions Mixed-method study is an appropriate strategy to know the perceptions of children about barriers and facilitators for physical activity, using both qualitative methods for a deeply understanding of their points of view, and quantitative methods for triangulate the discourse of participants with empirical data. We consider that this is an innovative approach that could provide knowledges for the development of more effective interventions to prevent childhood overweight. PMID:22978490

RPA facilitates telomerase activity at chromosome ends in budding and fission yeasts

PubMed Central

Luciano, Pierre; Coulon, Stéphane; Faure, Virginie; Corda, Yves; Bos, Julia; Brill, Steven J; Gilson, Eric; Simon, Marie-Noelle; Géli, Vincent

2012-01-01

In Saccharomyces cerevisiae, the telomerase complex binds to chromosome ends and is activated in late S-phase through a process coupled to the progression of the replication fork. Here, we show that the single-stranded DNA-binding protein RPA (replication protein A) binds to the two daughter telomeres during telomere replication but only its binding to the leading-strand telomere depends on the Mre11/Rad50/Xrs2 (MRX) complex. We further demonstrate that RPA specifically co-precipitates with yKu, Cdc13 and telomerase. The interaction of RPA with telomerase appears to be mediated by both yKu and the telomerase subunit Est1. Moreover, a mutation in Rfa1 that affects both the interaction with yKu and telomerase reduces the dramatic increase in telomere length of a rif1Δ, rif2Δ double mutant. Finally, we show that the RPA/telomerase association and function are conserved in Schizosaccharomyces pombe. Our results indicate that in both yeasts, RPA directly facilitates telomerase activity at chromosome ends. PMID:22354040

RPA facilitates telomerase activity at chromosome ends in budding and fission yeasts.

PubMed

Luciano, Pierre; Coulon, Stéphane; Faure, Virginie; Corda, Yves; Bos, Julia; Brill, Steven J; Gilson, Eric; Simon, Marie-Noelle; Géli, Vincent

2012-04-18

In Saccharomyces cerevisiae, the telomerase complex binds to chromosome ends and is activated in late S-phase through a process coupled to the progression of the replication fork. Here, we show that the single-stranded DNA-binding protein RPA (replication protein A) binds to the two daughter telomeres during telomere replication but only its binding to the leading-strand telomere depends on the Mre11/Rad50/Xrs2 (MRX) complex. We further demonstrate that RPA specifically co-precipitates with yKu, Cdc13 and telomerase. The interaction of RPA with telomerase appears to be mediated by both yKu and the telomerase subunit Est1. Moreover, a mutation in Rfa1 that affects both the interaction with yKu and telomerase reduces the dramatic increase in telomere length of a rif1Δ, rif2Δ double mutant. Finally, we show that the RPA/telomerase association and function are conserved in Schizosaccharomyces pombe. Our results indicate that in both yeasts, RPA directly facilitates telomerase activity at chromosome ends.

Essential features of long-term changes of areas and diameters of sunspot groups in solar activity cycles 12-24

NASA Astrophysics Data System (ADS)

Efimenko, V. M.; Lozitsky, V. G.

2018-06-01

We analyze the Greenwich catalog data on areas of sunspot groups of last thirteen solar cycles. Various parameters of sunspots are considered, namely: average monthly smoothed areas, maximum area for each year and equivalent diameters of groups of sunspots. The first parameter shows an exceptional power of the 19th cycle of solar activity, which appears here more contrastively than in the numbers of spots (that is, in Wolf's numbers). It was found that in the maximum areas of sunspot groups for a year there is a unique phenomenon: a short and high jump in the 18th cycle (in 1946-1947) that has no analogues in other cycles. We also studied the integral distributions for equivalent diameters and found the following: (a) the average value of the index of power-law approximation is 5.4 for the last 13 cycles and (b) there is reliable evidence of Hale's double cycle (about 44 years). Since this indicator reflects the dispersion of sunspot group diameters, the results obtained show that the convective zone of the Sun generates embryos of active regions in different statistical regimes which change with a cycle of about 44 years.

Comparison of solar activity during last two minima on turn of Activity Cycles 22/23 and 23/24

NASA Astrophysics Data System (ADS)

Gryciuk, Magdalena; Gburek, Szymon; Siarkowski, Marek; Podgorski, Piotr; Sylwester, Janusz; Farnik, Frantisek

2013-07-01

The subject of our work is the review and comparison of solar activity during the last two solar minima that occurred between recent activity cycles. We use the soft X-ray global solar corona observations covering the two nine-months long time intervals in 1997/98 and 2009. Data from RF15-I multichannel photometer are used for the penultimate minimum. For the last unusually deep and prolonged solar activity minimum in 2009 the data from SphinX spectrophotometer are used. Comparison of measurements from both minima takes place in the overlapping energy range 2-15 keV. We focus on the active region formation, evolution and flaring productivity during respective minima.

Hepatitis C virus stimulates low-density lipoprotein receptor expression to facilitate viral propagation.

PubMed

Syed, Gulam Hussain; Tang, Huihui; Khan, Mohsin; Hassanein, Tarek; Liu, Jingwen; Siddiqui, Aleem

2014-03-01

Lipids play a crucial role in multiple aspects of hepatitis C virus (HCV) life cycle. HCV modulates host lipid metabolism to enrich the intracellular milieu with lipids to facilitate its proliferation. However, very little is known about the influence of HCV on lipid uptake from bloodstream. Low-density lipoprotein receptor (LDLR) is involved in uptake of cholesterol rich low-density lipoprotein (LDL) particles from the bloodstream. The association of HCV particles with lipoproteins implicates their role in HCV entry; however, the precise role of LDLR in HCV entry still remains controversial. Here, we investigate the effect of HCV infection on LDLR expression and the underlying mechanism(s) involved. We demonstrate that HCV stimulates LDLR expression in both HCV-infected Huh7 cells and in liver tissue from chronic hepatitis C patients. Fluorescence activated cell sorting and immunofluorescence analysis revealed enhanced cell surface and total expression of LDLR in HCV-infected cells. Increased LDLR expression resulted in the enhanced uptake of lipoprotein particles by HCV-infected cells. Analysis of LDLR gene promoter identified a pivotal role of sterol-regulatory element binding proteins (SREBPs), in the HCV-mediated stimulation of LDLR transcription. In addition, HCV negatively modulated the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), a protein that facilitates LDLR degradation. Ectopic expression of wild-type PCSK9 or gain-of-function PCSK9 mutant negatively affected HCV replication. Overall, our results demonstrate that HCV regulates LDLR expression at transcriptional and posttranslational level via SREBPs and PCSK9 to promote lipid uptake and facilitate viral proliferation. HCV modulates host lipid metabolism to promote enrichment of lipids in intracellular environment, which are essential in multiple aspects of HCV life cycle. However, very little is known about the influence of HCV on lipid uptake from the bloodstream. LDLR is

Estimate of the effect of the 11-year solar activity cycle on the ozone content in the stratosphere

NASA Astrophysics Data System (ADS)

Gruzdev, A. N.

2014-09-01

Using spectral, cross-spectral, and regression methods, we analyzed the effect of the 11-year cycle of solar activity on the ozone content in the stratosphere and lower mesosphere via satellite measurement data obtained with the help of SBUV/SBUV2 instruments in 1978-2003. We revealed a high coherence between the ozone content and solar activity level on the solar cycle scale. In much of this area, the ozone content varies approximately in phase with the solar cycle; however, in areas of significant gradients of ozone mixing ratio in the middle stratosphere, the phase shift between ozone and solar oscillations can be considerable, up to π/2. This can be caused by dynamical processes. The altitude maxima of ozone sensitivity to the 11-year solar cycle were found in the upper vicinity of the stratopause (50-55 km), in the middle stratosphere (35-40 km), and the lower stratosphere (below 25 km). Maximal changes in ozone content in the solar cycle (up to 10% and more) were found in winter and spring in polar regions.

Active and Inactive Leg Hemodynamics during Sequential Single-Leg Interval Cycling.

PubMed

Gordon, Nicole; Abbiss, Chris R; Ihsan, Mohammed; Maiorana, Andrew J; Peiffer, Jeremiah J

2018-06-01

Leg order during sequential single-leg cycling (i.e., exercising both legs independently within a single session) may affect local muscular responses potentially influencing adaptations. This study examined the cardiovascular and skeletal muscle hemodynamic responses during double-leg and sequential single-leg cycling. Ten young healthy adults (28 ± 6 yr) completed six 1-min double-leg intervals interspersed with 1 min of passive recovery and, on a separate occasion, 12 (six with one leg followed by six with the other leg) 1-min single-leg intervals interspersed with 1 min of passive recovery. Oxygen consumption, heart rate, blood pressure, muscle oxygenation, muscle blood volume, and power output were measured throughout each session. Oxygen consumption, heart rate, and power output were not different between sets of single-leg intervals, but the average of both sets was lower than the double-leg intervals. Mean arterial pressure was higher during double-leg compared with sequential single-leg intervals (115 ± 9 vs 104 ± 9 mm Hg, P < 0.05) and higher during the initial compared with second set of single-leg intervals (108 ± 10 vs 101 ± 10 mm Hg, P < 0.05). The increase in muscle blood volume from baseline was similar between the active single leg and the double leg (267 ± 150 vs 214 ± 169 μM·cm, P = 0.26). The pattern of change in muscle blood volume from the initial to second set of intervals was significantly different (P < 0.05) when the leg was active in the initial (-52.3% ± 111.6%) compared with second set (65.1% ± 152.9%). These data indicate that the order in which each leg performs sequential single-leg cycling influences the local hemodynamic responses, with the inactive muscle influencing the stimulus experienced by the contralateral leg.

Self-oocyte activation and parthenogenesis: an unusual outcome of a misconducted IVF cycle.

PubMed

Socolov, Razvan; Ebner, Thomas; Gorduza, Vlad; Martiniuc, Violeta; Angioni, Stefano; Socolov, Demetra

2015-07-01

A rare cause of infertility is the lack of fertilisation with the spontaneous activation of oocytes, leading to parthenogenesis. We present such a case. The patient was a G1P0 38-year-old woman of African ethnicity, who requested an in vitro fertilisation (IVF) with donor sperm. She received a stimulation protocol of 75 IU of FSH/LH from day 3 of the cycle, which she interrupted after 2 d, and restarted with the same dosage for another 3 d from day 7, plus one administration of GnRH antagonist in day 10 of the cycle. With a follicle reaching 19 mm on day 11, estradiol of 325 ng/ml, ovulation was induced with hMG 5000 UI, and oocyte pick-up performed at 30 h. One oocyte was retrieved, and good-quality sperms were added to the insemination procedure. No fecundation occurred at 20 h, with the extruded oocyte separated from the granulosa wall. At 40 h and 64 h the aspect was of three cells, one cell with one nucleus, the others with high granulation and no visible nuclei. This case shows an unusual self-activation oocyte in a poorly managed IVF cycle. The patient will be further evaluated, to decide if a better managed stimulation protocol would prevent recurrence.

A map of protein dynamics during cell-cycle progression and cell-cycle exit

PubMed Central

Gookin, Sara; Min, Mingwei; Phadke, Harsha; Chung, Mingyu; Moser, Justin; Miller, Iain; Carter, Dylan

2017-01-01

The cell-cycle field has identified the core regulators that drive the cell cycle, but we do not have a clear map of the dynamics of these regulators during cell-cycle progression versus cell-cycle exit. Here we use single-cell time-lapse microscopy of Cyclin-Dependent Kinase 2 (CDK2) activity followed by endpoint immunofluorescence and computational cell synchronization to determine the temporal dynamics of key cell-cycle proteins in asynchronously cycling human cells. We identify several unexpected patterns for core cell-cycle proteins in actively proliferating (CDK2-increasing) versus spontaneously quiescent (CDK2-low) cells, including Cyclin D1, the levels of which we find to be higher in spontaneously quiescent versus proliferating cells. We also identify proteins with concentrations that steadily increase or decrease the longer cells are in quiescence, suggesting the existence of a continuum of quiescence depths. Our single-cell measurements thus provide a rich resource for the field by characterizing protein dynamics during proliferation versus quiescence. PMID:28892491

The Development of a New Practical Activity: Using Microorganisms to Model Gas Cycling

ERIC Educational Resources Information Center

Redfern, James; Burdass, Dariel; Verran, Joanna

2014-01-01

For many in the school science classroom, the term "microbiology" has become synonymous with "bacteriology". By overlooking other microbes, teachers may miss out on powerful practical tools. This article describes the development of an activity that uses algae and yeast to demonstrate gas cycling, and presents full instructions…

Facilitating Facilitators: Enhancing PBL through a Structured Facilitator Development Program

ERIC Educational Resources Information Center

Salinitri, Francine D.; Wilhelm, Sheila M.; Crabtree, Brian L.

2015-01-01

With increasing adoption of the problem-based learning (PBL) model, creative approaches to enhancing facilitator training and optimizing resources to maintain effective learning in small groups is essential. We describe a theoretical framework for the development of a PBL facilitator training program that uses the constructivist approach as the…

Becoming and staying physically active in adolescents with cerebral palsy: protocol of a qualitative study of facilitators and barriers to physical activity.

PubMed

Claassen, Aniek A O M; Gorter, Jan Willem; Stewart, Debra; Verschuren, Olaf; Galuppi, Barbara E; Shimmell, Lorie J

2011-01-07

Adolescents with cerebral palsy (CP) show a reduced physical activity (PA). Currently there are no interventions for adolescents with CP in this critical life phase that optimise and maintain the individuals' physical activity in the long term. To develop such a program it is important to fully understand the factors that influence physical activity behaviours in adolescents with CP. The aim of this study is to explore what makes it easy or hard for adolescents with CP to be and to become physically active. A qualitative research method is chosen to allow adolescents to voice their own opinion. Because we will investigate the lived experiences this study has a phenomenological approach. Thirty ambulatory and non-ambulatory adolescents (aged 10-18 years) with CP, classified as level I to IV on the Gross Motor Function Classification System and 30 parents of adolescents with CP will be invited to participate in one of the 6 focus groups or an individual interview. Therapists from all Children's Treatment Centres in Ontario, Canada, will be asked to fill in a survey. Focus groups will be audio- and videotaped and will approximately take 1.5 hours. The focus groups will be conducted by a facilitator and an assistant. In preparation of the focus groups, participants will fill in a demographic form with additional questions on physical activity. The information gathered from these questions and recent research on barriers and facilitators to physical activity will be used as a starting point for the content of the focus groups. Recordings of the focus groups will be transcribed and a content analysis approach will be used to code the transcripts. A preliminary summary of the coded data will be shared with the participants before themes will be refined. This study will help us gain insight and understanding of the participants' experiences and perspectives in PA, which can be of great importance when planning programs aimed at helping them to stay or to become physically

Becoming and staying physically active in adolescents with cerebral palsy: protocol of a qualitative study of facilitators and barriers to physical activity

PubMed Central

2011-01-01

Background Adolescents with cerebral palsy (CP) show a reduced physical activity (PA). Currently there are no interventions for adolescents with CP in this critical life phase that optimise and maintain the individuals' physical activity in the long term. To develop such a program it is important to fully understand the factors that influence physical activity behaviours in adolescents with CP. The aim of this study is to explore what makes it easy or hard for adolescents with CP to be and to become physically active. Methods/Design A qualitative research method is chosen to allow adolescents to voice their own opinion. Because we will investigate the lived experiences this study has a phenomenological approach. Thirty ambulatory and non-ambulatory adolescents (aged 10-18 years) with CP, classified as level I to IV on the Gross Motor Function Classification System and 30 parents of adolescents with CP will be invited to participate in one of the 6 focus groups or an individual interview. Therapists from all Children's Treatment Centres in Ontario, Canada, will be asked to fill in a survey. Focus groups will be audio- and videotaped and will approximately take 1.5 hours. The focus groups will be conducted by a facilitator and an assistant. In preparation of the focus groups, participants will fill in a demographic form with additional questions on physical activity. The information gathered from these questions and recent research on barriers and facilitators to physical activity will be used as a starting point for the content of the focus groups. Recordings of the focus groups will be transcribed and a content analysis approach will be used to code the transcripts. A preliminary summary of the coded data will be shared with the participants before themes will be refined. Discussion This study will help us gain insight and understanding of the participants' experiences and perspectives in PA, which can be of great importance when planning programs aimed at helping

Supporting Online AP Students: The Rural Facilitator and Considerations for Training

ERIC Educational Resources Information Center

Hendrix, Nicole; Degner, Katherine

2016-01-01

Online courses supplemented by on-site facilitators help many rural students pursue advanced coursework, but research is warranted to better understand facilitator role and training needs. This study examined facilitation experiences, demographic characteristics, and professional development activities of rural on-site facilitators associated with…

An EP2 Agonist Facilitates NMDA-Induced Outward Currents and Inhibits Dendritic Beading through Activation of BK Channels in Mouse Cortical Neurons

PubMed Central

Hayashi, Yoshinori; Morinaga, Saori; Liu, Xia; Zhang, Jing; Wu, Zhou; Yokoyama, Takeshi; Nakanishi, Hiroshi

2016-01-01

Prostaglandin E2 (PGE2), a major metabolite of arachidonic acid produced by cyclooxygenase pathways, exerts its bioactive responses by activating four E-prostanoid receptor subtypes, EP1, EP2, EP3, and EP4. PGE2 enables modulating N-methyl-D-aspartate (NMDA) receptor-mediated responses. However, the effect of E-prostanoid receptor agonists on large-conductance Ca2+-activated K+ (BK) channels, which are functionally coupled with NMDA receptors, remains unclear. Here, we showed that EP2 receptor-mediated signaling pathways increased NMDA-induced outward currents (I NMDA-OUT), which are associated with the BK channel activation. Patch-clamp recordings from the acutely dissociated mouse cortical neurons revealed that an EP2 receptor agonist activated I NMDA-OUT, whereas an EP3 receptor agonist reduced it. Agonists of EP1 or EP4 receptors showed no significant effects on I NMDA-OUT. A direct perfusion of 3,5′-cyclic adenosine monophosphate (cAMP) through the patch pipette facilitated I NMDA-OUT, which was abolished by the presence of protein kinase A (PKA) inhibitor. Furthermore, facilitation of I NMDA-OUT caused by an EP2 receptor agonist was significantly suppressed by PKA inhibitor. Finally, the activation of BK channels through EP2 receptors facilitated the recovery phase of NMDA-induced dendritic beading in the primary cultured cortical neurons. These results suggest that a direct activation of BK channels by EP2 receptor-mediated signaling pathways plays neuroprotective roles in cortical neurons. PMID:27298516

The barriers, benefits and facilitators of leisure time physical activity among people with spinal cord injury: a meta-synthesis of qualitative findings.

PubMed

Williams, Toni Louise; Smith, Brett; Papathomas, Anthony

2014-01-01

Physical activity (PA) can have a positive impact upon health and well-being for people with spinal cord injury (SCI). Despite these benefits, people with SCI are within the most physically inactive segment of society that comprises disabled people. This original meta-synthesis of qualitative research was undertaken to explore the barriers, benefits and facilitators of leisure time physical activity (LTPA) among people with SCI. Articles published since 2000 were identified through a rigorous search of electronic databases, supported with a hand search of relevant journals and papers. In total, 64 papers were read in full, and based on inclusion criteria, 18 were relevant for review. The key themes constructed from the data were summarised, compared and synthesised. Eight interrelated concepts were identified as barriers, benefits and/or facilitators of LTPA: (i) well-being (WB); (ii) environment; (iii) physical body; (iv) body-self relationship; (v) physically active identity; (vi) knowledge; (vii) restitution narrative; (viii) perceived absences. Based on the synthesised evidence, healthcare professionals need to appreciate the relationships between the barriers, benefits and facilitators of LTPA in order to successfully promote a physically active lifestyle. Equally, a more critical attitude to PA promotion is called for in terms of possible adverse consequences.

Honeybee Colony Vibrational Measurements to Highlight the Brood Cycle

PubMed Central

Bencsik, Martin; Le Conte, Yves; Reyes, Maritza; Pioz, Maryline; Whittaker, David; Crauser, Didier; Simon Delso, Noa; Newton, Michael I.

2015-01-01

Insect pollination is of great importance to crop production worldwide and honey bees are amongst its chief facilitators. Because of the decline of managed colonies, the use of sensor technology is growing in popularity and it is of interest to develop new methods which can more accurately and less invasively assess honey bee colony status. Our approach is to use accelerometers to measure vibrations in order to provide information on colony activity and development. The accelerometers provide amplitude and frequency information which is recorded every three minutes and analysed for night time only. Vibrational data were validated by comparison to visual inspection data, particularly the brood development. We show a strong correlation between vibrational amplitude data and the brood cycle in the vicinity of the sensor. We have further explored the minimum data that is required, when frequency information is also included, to accurately predict the current point in the brood cycle. Such a technique should enable beekeepers to reduce the frequency with which visual inspections are required, reducing the stress this places on the colony and saving the beekeeper time. PMID:26580393

Inhibition of E2F1 activity and cell cycle progression by arsenic via retinoblastoma protein.

PubMed

Sheldon, Lynn A

2017-01-01

The regulation of cell cycle progression by steroid hormones and growth factors is important for maintaining normal cellular processes including development and cell proliferation. Deregulated progression through the G1/S and G2/M cell cycle transitions can lead to uncontrolled cell proliferation and cancer. The transcription factor E2F1, a key cell cycle regulator, targets genes encoding proteins that regulate cell cycle progression through the G1/S transition as well as proteins important in DNA repair and apoptosis. E2F1 expression and activity is inhibited by inorganic arsenic (iAs) that has a dual role as a cancer therapeutic and as a toxin that leads to diseases including cancer. An understanding of what underlies this dichotomy will contribute to understanding how to use iAs as a more effective therapeutic and also how to treat cancers that iAs promotes. Here, we show that quiescent breast adenocarcinoma MCF-7 cells treated with 17-β estradiol (E2) progress through the cell cycle, but few cells treated with E2 + iAs progress from G1 into S-phase due to a block in cell cycle progression. Our data support a model in which iAs inhibits the dissociation of E2F1 from the tumor suppressor, retinoblastoma protein (pRB) due to changes in pRB phosphorylation which leads to decreased E2F1 transcriptional activity. These findings present an explanation for how iAs can disrupt cell cycle progression through E2F1-pRB and has implications for how iAs acts as a cancer therapeutic as well as how it may promote tumorigenesis through decreased DNA repair.

Nitric oxide is involved in hydrogen gas-induced cell cycle activation during adventitious root formation in cucumber.

PubMed

Zhu, Yongchao; Liao, Weibiao; Niu, Lijuan; Wang, Meng; Ma, Zhanjun

2016-06-28

Adventitious root development is a complex process regulated through a variety of signaling molecules. Hydrogen gas (H2) and nitric oxide (NO), two new signaling molecules are both involved in plant development and stress tolerance. To investigate the mechanism of adventitious root development induced by hydrogen-rich water (HRW), a combination of fluorescence microscopy and molecular approaches was used to study cell cycle activation and cell cycle-related gene expression in cucumber (Cucumis sativus 'Xinchun 4') explants. The results revealed that the effect of HRW on adventitious root development was dose-dependent, with maximal biological responses at 50 % HRW. HRW treatment increased NO content in a time-dependent fashion. The results also indicated that HRW and NO promoted the G1-to-S transition and up-regulated cell cycle-related genes: CycA (A-type cyclin), CycB (B-type cyclin), CDKA (cyclin-dependent kinase A) and CDKB (cyclin-dependent kinase B) expression. Additionally, target genes related to adventitious rooting were up-regulated by HRW and NO in cucumber explants. While, the responses of HRW-induced adventitious root development and increase of NO content were partially blocked by a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt, NO synthase (NOS)-like enzyme inhibitor N(G) -nitro-L-arginine methylester hydrochloride, or nitrate reductase inhibitors tungstate and NaN3. These chemicals also partially reversed the effect of HRW on cell cycle activation and the transcripts of cell cycle regulatory genes and target genes related adventitious root formation. Together, NO may emerge as a downstream signaling molecule in H2-induced adventitious root organogenesis. Additionally, H2 mediated cell cycle activation via NO pathway during adventitious root formation.

Cell Cycle-Dependent Rho GTPase Activity Dynamically Regulates Cancer Cell Motility and Invasion In Vivo

PubMed Central

Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

2013-01-01

The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers. PMID:24386239

Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

PubMed

Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

2013-01-01

The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

Activation of β-adrenoceptor facilitates active avoidance learning through enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Lv, Jing; Feng, Hao; Chen, Ling; Wang, Wei-Yao; Yue, Xue-Ling; Jin, Qing-Hua

2017-10-18

Long-term potentiation (LTP) is widely accepted as the best studied model for neurophysiological mechanisms that could underlie learning and memory formation. Despite a number of studies indicating that β-adrenoceptors in the hippocampal dentate gyrus (DG) is involved in the modulation of learning and memory as well as LTP, few studies have used glutamate release as a visual indicator in awake animals to explore the role of β-adrenoceptors in learning-dependent LTP. Therefore, in the present study, the effects of propranolol (an antagonist of β-adrenoceptor) and isoproterenol (an agonist of β-adrenoceptor) on extracellular concentrations of glutamate and amplitudes of field excitatory postsynaptic potential were measured in the DG region during active avoidance learning in freely moving conscious rats. In the control group, the glutamate level in the DG was significantly increased during the acquisition of active avoidance behavior and returned to basal level following extinction training. In propranolol group, antagonism of β-adrenoceptors in the DG significantly reduced the change in glutamate level, and the acquisition of the active avoidance behavior was significantly inhibited. In contrast, the change in glutamate level was significantly enhanced by isoproterenol, and the acquisition of the active avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in glutamate level were accompanied by corresponding changes in field excitatory postsynaptic potential amplitude and active avoidance behavior. Our results suggest that activation of β-adrenoceptors in the hippocampal DG facilitates active avoidance learning by modulations of glutamate level and synaptic efficiency in rats.

Influence of time, storage temperature and freeze/thaw cycles on the activity of digestive enzymes from gilthead sea bream (Sparus aurata).

PubMed

Solovyev, Mikhail; Gisbert, Enric

2016-10-01

In this study, we tested the effects of long-term storage (2 years) at -20 °C and short-term storage (several hours) in ice and freeze/thaw cycles on the activities of pancreatic, gastric and intestinal (brush border and cytosolic) digestive enzymes in a teleost fish species. The results revealed a significant lose in activity of pancreatic (trypsin, chymotrypsin, total alkaline proteases and α-amylase) and intestinal cytosolic (leucine-alanine peptidase) enzymes between 140 and 270 days of storage at -20 °C, whereas in contrast, the activity of all the assayed brush border enzymes remained constant during the first 2 years of storage at -20 °C. During short-term storage conditions, the most stable enzymes assayed were those of the enterocytes of the brush border, which did not show any change in activity after being held for 5 h in ice. Five freezing and thawing cycles did not affect the activity of the intestinal brush border enzymes and the cytosolic ones, whereas the activity of trypsin, α-amylase and bile-salt-activated lipase was significantly affected by the number of freezing and thawing cycles. No changes in pepsin activity were found in samples exposed to 1 and 2 freezing and thawing cycles.

The Sequence of Learning Cycle Activities in High School Chemistry.

ERIC Educational Resources Information Center

Abraham, Michael R.; Renner, John W.

1986-01-01

Different learning cycle sequences were investigated to determine factors accounting for success of the cycle, compared learning with conventional instruction, and examined relationships between Piaget's theory and learning cycles. Results show that the normal learning cycle sequence is the optimum sequence for achievement of content knowledge in…

Contextualizing Solar Cycle 24: Report on the Development of a Homogenous Database of Bipolar Active Regions Spanning Four Cycles

NASA Astrophysics Data System (ADS)

Munoz-Jaramillo, A.; Werginz, Z. A.; DeLuca, M. D.; Vargas-Acosta, J. P.; Longcope, D. W.; Harvey, J. W.; Martens, P.; Zhang, J.; Vargas-Dominguez, S.; DeForest, C. E.; Lamb, D. A.

2015-12-01

The solar cycle can be understood as a process that alternates the large-scale magnetic field of the Sun between poloidal and toroidal configurations. Although the process that transitions the solar cycle between toroidal and poloidal phases is still not fully understood, theoretical studies, and observational evidence, suggest that this process is driven by the emergence and decay of bipolar magnetic regions (BMRs) at the photosphere. Furthermore, the emergence of BMRs at the photosphere is the main driver behind solar variability and solar activity in general; making the study of their properties doubly important for heliospheric physics. However, in spite of their critical role, there is still no unified catalog of BMRs spanning multiple instruments and covering the entire period of systematic measurement of the solar magnetic field (i.e. 1975 to present).In this presentation we discuss an ongoing project to address this deficiency by applying our Bipolar Active Region Detection (BARD) code on full disk magnetograms measured by the 512 (1975-1993) and SPMG (1992-2003) instruments at the Kitt Peak Vacuum Telescope (KPVT), SOHO/MDI (1996-2011) and SDO/HMI (2010-present). First we will discuss the results of our revitalization of 512 and SPMG KPVT data, then we will discuss how our BARD code operates, and finally report the results of our cross-callibration.The corrected and improved KPVT magnetograms will be made available through the National Solar Observatory (NSO) and Virtual Solar Observatory (VSO), including updated synoptic maps produced by running the corrected KPVT magnetograms though the SOLIS pipeline. The homogeneous active region database will be made public by the end of 2017 once it has reached a satisfactory level of quality and maturity. The Figure shows all bipolar active regions present in our database (as of Aug 2015) colored according to the sign of their leading polarity. Marker size is indicative of the total active region flux. Anti

An early solar dynamo prediction: Cycle 23 is approximately cycle 22

NASA Technical Reports Server (NTRS)

Schatten, Kenneth H.; Pesnell, W. Dean

1993-01-01

In this paper, we briefly review the 'dynamo' and 'geomagnetic precursor' methods of long-term solar activity forecasting. These methods depend upon the most basic aspect of dynamo theory to predict future activity, future magnetic field arises directly from the magnification of pre-existing magnetic field. We then generalize the dynamo technique, allowing the method to be used at any phase of the solar cycle, through the development of the 'Solar Dynamo Amplitude' (SODA) index. This index is sensitive to the magnetic flux trapped within the Sun's convection zone but insensitive to the phase of the solar cycle. Since magnetic fields inside the Sun can become buoyant, one may think of the acronym SODA as describing the amount of buoyant flux. Using the present value of the SODA index, we estimate that the next cycle's smoothed peak activity will be about 210 +/- 30 solar flux units for the 10.7 cm radio flux and a sunspot number of 170 +/- 25. This suggests that solar cycle #23 will be large, comparable to cycle #22. The estimated peak is expected to occur near 1999.7 +/- 1 year. Since the current approach is novel (using data prior to solar minimum), these estimates may improve when the upcoming solar minimum is reached.

Tracking the MJO Convection and its Impact on the Diurnal Cycle over the Maritime Continent Using Satellite Observations

NASA Astrophysics Data System (ADS)

Kerns, B. W.; Chen, S. S.

2017-12-01

The Indo-Pacific Maritime Continent (MC) is the most active convection center in the tropics, and the most important modes of variability are the diurnal cycle and the Madden-Julian Oscillation (MJO). Previous studies have shown that the MC has strong diurnal variability compared with the rest of the tropics, and the diurnal cycle of convection over the MC is amplified during the passage of an MJO. One outstanding science question is how the passage of the active MJO affects the diurnal cycle. The atmospheric, upper ocean, and land surface forcing factors contributing to the diurnal cycle need to be clarified. In order to address this, large scale precipitation tracking (LPT) is used to identify MJO active and suppressed periods for 2000-2015. To document the diurnal cycle of convection during the active and suppressed periods, TRMM/GPM and mesoscale cloud cluster tracking are used. Finally, the LPT tracking is used to composite the satellite-estimated surface wind, humidity, temperature, cloud cover, and soil moisture over the islands for active versus suppressed MJO periods. In active MJO periods, the diurnal convection in the surrounding marginal seas is enhanced and the diurnal convection over land is decreased. The islands of the MC have greater soil moisture, more cloud cover, and do not warm up as much during the day, leading to a weaker afternoon maximum over land. But how is nocturnal convection over the sea increased? The largest, most mature convective cloud systems are found over the marginal seas in the early morning. This is hypothesized to mainly be a consequence of the longer life cycle of convective systems in the favorable large-scale active MJO. The propagation of the MJO across the MC is facilitated by the enhanced nocturnal deep convection over the sea. In contrast, In the suppressed period the convection is mostly daytime forced convection over land which is locked to the terrain.

Barriers and facilitators to the implementation of a school-based physical activity policy in Canada: application of the theoretical domains framework.

PubMed

Weatherson, Katie A; McKay, Rhyann; Gainforth, Heather L; Jung, Mary E

2017-10-23

In British Columbia Canada, a Daily Physical Activity (DPA) policy was mandated that requires elementary school teachers to provide students with opportunities to achieve 30 min of physical activity during the school day. However, the implementation of school-based physical activity policies is influenced by many factors. A theoretical examination of the factors that impede and enhance teachers' implementation of physical activity policies is necessary in order to develop strategies to improve policy practice and achieve desired outcomes. This study used the Theoretical Domains Framework (TDF) to understand teachers' barriers and facilitators to the implementation of the DPA policy in one school district. Additionally, barriers and facilitators were examined and compared according to how the teacher implemented the DPA policy during the instructional school day. Interviews were conducted with thirteen teachers and transcribed verbatim. One researcher performed barrier and facilitator extraction, with double extraction occurring across a third of the interview transcripts by a second researcher. A deductive and inductive analytical approach in a two-stage process was employed whereby barriers and facilitators were deductively coded using TDF domains (content analysis) and analyzed for sub-themes within each domain. Two researchers performed coding. A total of 832 items were extracted from the interview transcripts. Some items were coded into multiple TDF domains, resulting in a total of 1422 observations. The most commonly coded TDF domains accounting for 75% of the total were Environmental context and resources (ECR; n = 250), Beliefs about consequences (n = 225), Social influences (n = 193), Knowledge (n = 100), and Intentions (n = 88). Teachers who implemented DPA during instructional time differed from those who relied on non-instructional time in relation to Goals, Behavioural regulation, Social/professional role and identity, Beliefs about

Phrenic Long-Term Facilitation Requires PKCθ Activity within Phrenic Motor Neurons

PubMed Central

Devinney, Michael J.; Fields, Daryl P.; Huxtable, Adrianne G.; Peterson, Timothy J.; Dale, Erica A.

2015-01-01

Acute intermittent hypoxia (AIH) induces a form of spinal motor plasticity known as phrenic long-term facilitation (pLTF); pLTF is a prolonged increase in phrenic motor output after AIH has ended. In anesthetized rats, we demonstrate that pLTF requires activity of the novel PKC isoform, PKCθ, and that the relevant PKCθ is within phrenic motor neurons. Whereas spinal PKCθ inhibitors block pLTF, inhibitors targeting other PKC isoforms do not. PKCθ is highly expressed in phrenic motor neurons, and PKCθ knockdown with intrapleural siRNAs abolishes pLTF. Intrapleural siRNAs targeting PKCζ, an atypical PKC isoform expressed in phrenic motor neurons that underlies a distinct form of phrenic motor plasticity, does not affect pLTF. Thus, PKCθ plays a critical role in spinal AIH-induced respiratory motor plasticity, and the relevant PKCθ is localized within phrenic motor neurons. Intrapleural siRNA delivery has considerable potential as a therapeutic tool to selectively manipulate plasticity in vital respiratory motor neurons. PMID:26019328

Strategic Origins of Early Semantic Facilitation in the Blocked-Cyclic Naming Paradigm

ERIC Educational Resources Information Center

Belke, Eva; Shao, Zeshu; Meyer, Antje S.

2017-01-01

In the blocked-cyclic naming paradigm, participants repeatedly name small sets of objects that do or do not belong to the same semantic category. A standard finding is that, after a first presentation cycle where one might find semantic facilitation, naming is slower in related (homogeneous) than in unrelated (heterogeneous) sets. According to…

The vastus lateralis neuromuscular activity during all-out cycling exercise.

PubMed

Bercier, Stephane; Halin, Renaud; Ravier, Philippe; Kahn, Jean-Francois; Jouanin, Jean-Claude; Lecoq, Anne-Marie; Buttelli, Olivier

2009-10-01

The objective of this work was to study modifications in motor control through surface electromyographic (sEMG) activity during a very short all-out cycling exercise. Twelve male cyclists (age 23+/-4 years) participated in this study. After a warm-up period, each subject performed three all-out cycling exercises of 6s separated by 2 min of complete rest. This protocol was repeated three times with a minimum of 2 days between each session. The braking torque imposed on cycling motion was 19 Nm. The sEMG of the vastus lateralis was recorded during the first seven contractions of the sprint. Time-frequency analysis of sEMG was performed using continuous wavelet transform. The mean power frequency (MPF, qualitative modifications in the recruitment of motor units) and signal energy (a quantitative indicator of modifications in the motor units recruitment) were computed for the frequency range 10-500 Hz. sEMG energy increased (P0.05) between contraction number 1 and 2, decreased (P < or =0.05) between contraction number 2 and 3 then stabilized between contraction number 3 and 7 during the all-out test. MPF increased (P < or =0.05) during the all-out test. This increase was more marked during the first two contractions. The decrease in energy and the increase in the sEMG MPF suggest a large spatial recruitment of motor units (MUs) at the beginning of the sprint followed by a preferential recruitment of faster MUs at the end of the sprint, respectively.

Understanding Solar Cycle Variability

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

Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de

The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to amore » generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.« less

Barriers and facilitators to young children's physical activity and sedentary behaviour: a systematic review and synthesis of qualitative literature

PubMed Central

Lakshman, R.; van Sluijs, E. M. F.

2017-01-01

Summary Positive activity behaviours (i.e. higher physical activity [PA]/lower sedentary behaviour [SB]) are beneficial from infancy, yet evidence suggests that young children (0‐ to 6‐year‐olds) are relatively inactive. To better understand the perceived influences on these behaviours and to aid intervention development, this paper systematically synthesizes the extensive qualitative literature regarding perceived barriers and facilitators to PA and SB in young children (0–6 years old). A search of eight electronic databases (July 2016) identified 43 papers for inclusion. Data extraction and evidence synthesis were conducted using thematic content analysis, underpinned by the socio‐ecological model (i.e. individual, interpersonal, community, organizational and policy levels). Parents, childcare providers and children perceived seven broad themes to be important for PA and SB, including the child; the home; out‐of‐home childcare; parent–childcare provider interactions; environmental factors; safety; and weather. Each theme mapped onto between one and five levels of the socio‐ecological model; barriers and facilitators at the interpersonal level (e.g. parents, care providers and family) were most frequently cited, reflecting the important (perceived) role adults/peers play in shaping young children's behaviours. We provide an overarching framework to explain PA and SB in early childhood. We also highlight where gaps in the current literature exist (e.g. from male carers; in developing countries; and barriers and facilitators in the environmental and policy domains) and where future quantitative work may focus to provide novel insights about children's activity behaviours (e.g. safety and weather). PMID:28589678

Serpin Facilitates Tumor-Suppressive Cell Competition by Blocking Toll-Mediated Yki Activation in Drosophila.

PubMed

Katsukawa, Mitsuko; Ohsawa, Shizue; Zhang, Lina; Yan, Yan; Igaki, Tatsushi

2018-06-04

Normal epithelial tissue exerts an intrinsic tumor-suppressive effect against oncogenically transformed cells. In Drosophila imaginal epithelium, clones of oncogenic polarity-deficient cells mutant for scribble (scrib) or discs large (dlg) are eliminated by cell competition when surrounded by wild-type cells. Here, through a genetic screen in Drosophila, we identify Serpin5 (Spn5), a secreted negative regulator of Toll signaling, as a crucial factor for epithelial cells to eliminate scrib mutant clones from epithelium. Downregulation of Spn5 in wild-type cells leads to elevation of Toll signaling in neighboring scrib cells. Strikingly, forced activation of Toll signaling or Toll-related receptor (TRR) signaling in scrib clones transforms scrib cells from losers to supercompetitors, resulting in tumorous overgrowth of mutant clones. Mechanistically, Toll activation in scrib clones leads to c-Jun N-terminal kinase (JNK) activation and F-actin accumulation, which cause strong activation of the Hippo pathway effector Yorkie that blocks cell death and promotes cell proliferation. Our data suggest that Spn5 secreted from normal epithelial cells acts as a component of the extracellular surveillance system that facilitates elimination of pre-malignant cells from epithelium. Copyright © 2018 Elsevier Ltd. All rights reserved.

New insights into the Vav1 activation cycle in lymphocytes.

PubMed

Barreira, María; Rodríguez-Fdez, Sonia; Bustelo, Xosé R

2018-05-01

Vav1 is a hematopoietic-specific Rho GDP/GTP exchange factor and signaling adaptor. Although these activities are known to be stimulated by direct Vav1 phosphorylation, little information still exists regarding the regulatory layers that influence the overall Vav1 activation cycle. Using a collection of cell models and activation-mimetic Vav1 mutants, we show here that the dephosphorylated state of Vav1 in nonstimulated T cells requires the presence of a noncatalytic, phospholipase Cγ1-Slp76-mediated inhibitory pathway. Upon T cell stimulation, Vav1 becomes rapidly phosphorylated via the engagement of Lck and, to a much lesser extent, other Src family kinases and Zap70. In this process, Lck, Zap70 and the adaptor protein Lat contribute differently to the dynamics and amplitude of the Vav1 phosphorylated pool. Consistent with a multiphosphosite activation mechanism, the optimal stimulation of Vav1 can only be recapitulated by the combination of several activation-mimetic phosphosite mutants. The analysis of these mutants has also unveiled the presence of different Vav1 signaling competent states that are influenced by phosphosites present in the N- and C-terminal domains of the protein. Copyright © 2018 Elsevier Inc. All rights reserved.

Accumulation of Succinate in Cardiac Ischemia Primarily Occurs via Canonical Krebs Cycle Activity.

PubMed

Zhang, Jimmy; Wang, Yves T; Miller, James H; Day, Mary M; Munger, Joshua C; Brookes, Paul S

2018-05-29

Succinate accumulates during ischemia, and its oxidation at reperfusion drives injury. The mechanism of ischemic succinate accumulation is controversial and is proposed to involve reversal of mitochondrial complex II. Herein, using stable-isotope-resolved metabolomics, we demonstrate that complex II reversal is possible in hypoxic mitochondria but is not the primary succinate source in hypoxic cardiomyocytes or ischemic hearts. Rather, in these intact systems succinate primarily originates from canonical Krebs cycle activity, partly supported by aminotransferase anaplerosis and glycolysis from glycogen. Augmentation of canonical Krebs cycle activity with dimethyl-α-ketoglutarate both increases ischemic succinate accumulation and drives substrate-level phosphorylation by succinyl-CoA synthetase, improving ischemic energetics. Although two-thirds of ischemic succinate accumulation is extracellular, the remaining one-third is metabolized during early reperfusion, wherein acute complex II inhibition is protective. These results highlight a bifunctional role for succinate: its complex-II-independent accumulation being beneficial in ischemia and its complex-II-dependent oxidation being detrimental at reperfusion. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Activation of PPARγ mediates icaritin-induced cell cycle arrest and apoptosis in glioblastoma multiforme.

PubMed

Liu, Yongji; Shi, Ling; Liu, Yuan; Li, Peng; Jiang, Guoping; Gao, Xiaoning; Zhang, Yongbin; Jiang, Chuanwu; Zhu, Weiping; Han, Hongxing; Ju, Fang

2018-04-01

Glioblastoma multiforme (GBM) is the most prevalent primary malignancy of the brain. This study was designed to investigate whether icaritin exerts anti-neoplastic activity against GBM in vitro. Cell Counting Kit-8 (CCK-8) assay was utilized to examine the viability of GBM cells. The apoptotic cell population was measured by flow cytometry analysis. Cell cycle distribution was detected by flow cytometry as well. Western blot analysis was performed to examine the level of biomarker proteins in GBM cells. Levels of PPARγ mRNA and protein were detected by qPCR and western blot analysis, respectively. To examine the role of PPARγ in the anti-neoplastic activity of icaritin, PPARγ antagonist GW9662 or PPARγ siRNA was used. The activity of PPARγ was determined by DNA binding and luciferase assays. Our findings revealed that icaritin markedly suppresses cell growth in a dose-dependent and time-dependent fashion. The cell population at the G0/G1 phase of the cell cycle was significantly increased following icaritin treatment. Meanwhile, icaritin promoted apoptotic cell death in T98G and U87MG cells. Further investigation showed upregulation of PPARγ played a key role in the anti-neoplastic activities of icaritin. Moreover, our result demonstrated activation of AMPK signaling by icaritin mediated the modulatory effect of icaritin on PPARγ. Our results suggest the PPARγ may mediate anti-neoplastic activities against GBM. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Autophagy Facilitates IFN-γ-induced Jak2-STAT1 Activation and Cellular Inflammation*

PubMed Central

Chang, Yu-Ping; Tsai, Cheng-Chieh; Huang, Wei-Ching; Wang, Chi-Yun; Chen, Chia-Ling; Lin, Yee-Shin; Kai, Jui-In; Hsieh, Chia-Yuan; Cheng, Yi-Lin; Choi, Pui-Ching; Chen, Shun-Hua; Chang, Shih-Ping; Liu, Hsiao-Sheng; Lin, Chiou-Feng

2010-01-01

Autophagy is regulated for IFN-γ-mediated antimicrobial efficacy; however, its molecular effects for IFN-γ signaling are largely unknown. Here, we show that autophagy facilitates IFN-γ-activated Jak2-STAT1. IFN-γ induces autophagy in wild-type but not in autophagy protein 5 (Atg5−/−)-deficient mouse embryonic fibroblasts (MEFs), and, autophagy-dependently, IFN-γ induces IFN regulatory factor 1 and cellular inflammatory responses. Pharmacologically inhibiting autophagy using 3-methyladenine, a known inhibitor of class III phosphatidylinositol 3-kinase, confirms these effects. Either Atg5−/− or Atg7−/− MEFs are, independent of changes in IFN-γ receptor expression, resistant to IFN-γ-activated Jak2-STAT1, which suggests that autophagy is important for IFN-γ signal transduction. Lentivirus-based short hairpin RNA for Atg5 knockdown confirmed the importance of autophagy for IFN-γ-activated STAT1. Without autophagy, reactive oxygen species increase and cause SHP2 (Src homology-2 domain-containing phosphatase 2)-regulated STAT1 inactivation. Inhibiting SHP2 reversed both cellular inflammation and the IFN-γ-induced activation of STAT1 in Atg5−/− MEFs. Our study provides evidence that there is a link between autophagy and both IFN-γ signaling and cellular inflammation and that autophagy, because it inhibits the expression of reactive oxygen species and SHP2, is pivotal for Jak2-STAT1 activation. PMID:20592027

Fifteen years in the high-energy life of the solar-type star HD 81809. XMM-Newton observations of a stellar activity cycle

NASA Astrophysics Data System (ADS)

Orlando, S.; Favata, F.; Micela, G.; Sciortino, S.; Maggio, A.; Schmitt, J. H. M. M.; Robrade, J.; Mittag, M.

2017-09-01

Context. The modulation of the activity level of solar-like stars is commonly revealed by cyclic variations in their chromospheric indicators, such as the Ca II H&K S-index, similarly to what is observed in our Sun. However, while the variation of solar activity is also reflected in the cyclical modulation of its coronal X-ray emission, similar behavior has only been discovered in a few stars other than the Sun. Aims: The data set of the long-term XMM-Newton monitoring program of HD 81809 is analyzed to study its X-ray cycle, investigate if the latter is related to the chromospheric cycle, infer the structure of the corona of HD 81809, and explore if the coronal activity of HD 81809 can be ascribed to phenomena similar to solar activity and, therefore, considered an extension of the solar case. Methods: We analyzed the observations of HD 81809 performed with XMM-Newton with a regular cadence of six months from 2001 to 2016, which represents one of the longest available observational baseline ( 15 yr) for a solar-like star with a well-studied chromospheric cycle (with a period of 8 yr). We investigated the modulation of coronal luminosity and temperature and its relation with the chromospheric cycle. We interpreted the data in terms of a mixture of solar-like coronal regions, adopting a method originally proposed to study the Sun as an X-ray star. Results: The observations show a well-defined regular cyclic modulation of the X-ray luminosity that reflects the activity level of HD 81809. The data covers approximately two cycles of coronal activity; the modulation has an amplitude of a factor of 5 (excluding evident flares, as in the June 2002 observation) and a period of 7.3 ± 1.5 yr, which is consistent with that of the chromospheric cycle. We demonstrate that the corona of HD 81809 can be interpreted as an extension of the solar case and can be modeled with a mixture of solar-like coronal regions along the whole cycle. The activity level is mainly determined by

Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae

PubMed Central

Ioannou, Petros; Andrianaki, Aggeliki; Akoumianaki, Tonia; Kyrmizi, Irene; Albert, Nathaniel; Perlin, David; Samonis, George

2015-01-01

The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P < 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery to Aspergillus hyphae. PMID:26643329

Alternative Oxidase Isoforms Are Differentially Activated by Tricarboxylic Acid Cycle Intermediates.

PubMed

Selinski, Jennifer; Hartmann, Andreas; Deckers-Hebestreit, Gabriele; Day, David A; Whelan, James; Scheibe, Renate

2018-02-01

The cyanide-insensitive alternative oxidase (AOX) is a non-proton-pumping ubiquinol oxidase that catalyzes the reduction of oxygen to water and is posttranslationally regulated by redox mechanisms and 2-oxo acids. Arabidopsis ( Arabidopsis thaliana ) possesses five AOX isoforms (AOX1A-AOX1D and AOX2). AOX1D expression is increased in aox1a knockout mutants from Arabidopsis (especially after restriction of the cytochrome c pathway) but cannot compensate for the lack of AOX1A, suggesting a difference in the regulation of these isoforms. Therefore, we analyzed the different AOX isoenzymes with the aim to identify differences in their posttranslational regulation. Seven tricarboxylic acid cycle intermediates (citrate, isocitrate, 2-oxoglutarate, succinate, fumarate, malate, and oxaloacetate) were tested for their influence on AOX1A, AOX1C, and AOX1D wild-type protein activity using a refined in vitro system. AOX1C is insensitive to all seven organic acids, AOX1A and AOX1D are both activated by 2-oxoglutarate, but only AOX1A is additionally activated by oxaloacetate. Furthermore, AOX isoforms cannot be transformed to mimic one another by substituting the variable cysteine residues at position III in the protein. In summary, we show that AOX isoforms from Arabidopsis are differentially fine-regulated by tricarboxylic acid cycle metabolites (most likely depending on the amino-terminal region around the highly conserved cysteine residues known to be involved in regulation by the 2-oxo acids pyruvate and glyoxylate) and propose that this is the main reason why they cannot functionally compensate for each other. © 2018 American Society of Plant Biologists. All Rights Reserved.

Interventions to promote cycling: systematic review

PubMed Central

Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J

2010-01-01

Objectives To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Design Systematic review. Data sources Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled “before and after” experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Results Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of “environmentally friendly” modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Conclusions Community-wide promotional activities and improving infrastructure for cycling have the potential to

Interventions to promote cycling: systematic review.

PubMed

Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J; Ogilvie, David

2010-10-18

To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Systematic review. Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled "before and after" experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of "environmentally friendly" modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Community-wide promotional activities and improving infrastructure for cycling have the potential to increase cycling by modest amounts, but further controlled

Global changes in biogeochemical cycles in response to human activities

NASA Technical Reports Server (NTRS)

Moore, Berrien, III; Melillo, Jerry

1994-01-01

The main objective of our research was to characterize biogeochemical cycles at continental and global scales in both terrestrial and aquatic ecosystems. This characterization applied to both natural ecosystems and those disturbed by human activity. The primary elements of interest were carbon and nitrogen and the analysis sought to quantify standing stocks and dynamic cycling processes. The translocation of major nutrients from the terrestrial landscape to the atmosphere (via trace gases) and to fluvial systems (via leaching, erosional losses, and point source pollution) were of particular importance to this study. Our aim was to develop the first generation of Earth System Models. Our research was organized around the construction and testing of component biogeochemical models which treated terrestrial ecosystem processes, aquatic nutrient transport through drainage basins, and trace gas exchanges at the continental and global scale. A suite of three complementary models were defined within this construct. The models were organized to operate at a 1/2 degree latitude by longitude level of spatial resolution and to execute at a monthly time step. This discretization afforded us the opportunity to understand the dynamics of the biosphere down to subregional scales, while simultaneously placing these dynamics into a global context.

Human frataxin activates Fe-S cluster biosynthesis by facilitating sulfur transfer chemistry.

PubMed

Bridwell-Rabb, Jennifer; Fox, Nicholas G; Tsai, Chi-Lin; Winn, Andrew M; Barondeau, David P

2014-08-05

Iron-sulfur clusters are ubiquitous protein cofactors with critical cellular functions. The mitochondrial Fe-S assembly complex, which consists of the cysteine desulfurase NFS1 and its accessory protein (ISD11), the Fe-S assembly protein (ISCU2), and frataxin (FXN), converts substrates l-cysteine, ferrous iron, and electrons into Fe-S clusters. The physiological function of FXN has received a tremendous amount of attention since the discovery that its loss is directly linked to the neurodegenerative disease Friedreich's ataxia. Previous in vitro results revealed a role for human FXN in activating the cysteine desulfurase and Fe-S cluster biosynthesis activities of the Fe-S assembly complex. Here we present radiolabeling experiments that indicate FXN accelerates the accumulation of sulfur on ISCU2 and that the resulting persulfide species is viable in the subsequent synthesis of Fe-S clusters. Additional mutagenesis, enzyme kinetic, UV-visible, and circular dichroism spectroscopic studies suggest conserved ISCU2 residue C104 is critical for FXN activation, whereas C35, C61, and C104 are all essential for Fe-S cluster formation on the assembly complex. These results cannot be fully explained by the hypothesis that FXN functions as an iron donor for Fe-S cluster biosynthesis, and further support an allosteric regulator role for FXN. Together, these results lead to an activation model in which FXN accelerates persulfide formation on NFS1 and favors a helix-to-coil interconversion on ISCU2 that facilitates the transfer of sulfur from NFS1 to ISCU2 as an initial step in Fe-S cluster biosynthesis.

Human Frataxin Activates Fe–S Cluster Biosynthesis by Facilitating Sulfur Transfer Chemistry

PubMed Central

2015-01-01

Iron–sulfur clusters are ubiquitous protein cofactors with critical cellular functions. The mitochondrial Fe–S assembly complex, which consists of the cysteine desulfurase NFS1 and its accessory protein (ISD11), the Fe–S assembly protein (ISCU2), and frataxin (FXN), converts substrates l-cysteine, ferrous iron, and electrons into Fe–S clusters. The physiological function of FXN has received a tremendous amount of attention since the discovery that its loss is directly linked to the neurodegenerative disease Friedreich’s ataxia. Previous in vitro results revealed a role for human FXN in activating the cysteine desulfurase and Fe–S cluster biosynthesis activities of the Fe–S assembly complex. Here we present radiolabeling experiments that indicate FXN accelerates the accumulation of sulfur on ISCU2 and that the resulting persulfide species is viable in the subsequent synthesis of Fe–S clusters. Additional mutagenesis, enzyme kinetic, UV–visible, and circular dichroism spectroscopic studies suggest conserved ISCU2 residue C104 is critical for FXN activation, whereas C35, C61, and C104 are all essential for Fe–S cluster formation on the assembly complex. These results cannot be fully explained by the hypothesis that FXN functions as an iron donor for Fe–S cluster biosynthesis, and further support an allosteric regulator role for FXN. Together, these results lead to an activation model in which FXN accelerates persulfide formation on NFS1 and favors a helix-to-coil interconversion on ISCU2 that facilitates the transfer of sulfur from NFS1 to ISCU2 as an initial step in Fe–S cluster biosynthesis. PMID:24971490

Stochastic E2F activation and reconciliation of phenomenological cell-cycle models.

PubMed

Lee, Tae J; Yao, Guang; Bennett, Dorothy C; Nevins, Joseph R; You, Lingchong

2010-09-21

The transition of the mammalian cell from quiescence to proliferation is a highly variable process. Over the last four decades, two lines of apparently contradictory, phenomenological models have been proposed to account for such temporal variability. These include various forms of the transition probability (TP) model and the growth control (GC) model, which lack mechanistic details. The GC model was further proposed as an alternative explanation for the concept of the restriction point, which we recently demonstrated as being controlled by a bistable Rb-E2F switch. Here, through a combination of modeling and experiments, we show that these different lines of models in essence reflect different aspects of stochastic dynamics in cell cycle entry. In particular, we show that the variable activation of E2F can be described by stochastic activation of the bistable Rb-E2F switch, which in turn may account for the temporal variability in cell cycle entry. Moreover, we show that temporal dynamics of E2F activation can be recast into the frameworks of both the TP model and the GC model via parameter mapping. This mapping suggests that the two lines of phenomenological models can be reconciled through the stochastic dynamics of the Rb-E2F switch. It also suggests a potential utility of the TP or GC models in defining concise, quantitative phenotypes of cell physiology. This may have implications in classifying cell types or states.

Temperature oscillations drive cycles in the activity of MMP-2,9 secreted by a human trabecular meshwork cell line.

PubMed

Li, Stanley Ka-Lok; Banerjee, Juni; Jang, Christopher; Sehgal, Amita; Stone, Richard A; Civan, Mortimer M

2015-02-05

Aqueous humor inflow falls 50% during sleeping hours without proportional fall in IOP, partly reflecting reduced outflow facility. The mechanisms underlying outflow facility cycling are unknown. One outflow facility regulator is matrix metalloproteinase (MMP) release from trabecular meshwork (TM) cells. Because anterior segment temperature must oscillate due to core temperature cycling and eyelid closure during sleep, we tested whether physiologically relevant temperature oscillations drive cycles in the activity of secreted MMP. Temperature of transformed normal human TM cells (hTM5 line) was fixed or alternated 12 hours/12 hours between 33°C and 37°C. Activity of secreted MMP-2 and MMP-9 was measured by zymography, and gene expression by RT-PCR and quantitative PCR. Raising temperature to 37°C increased, and lowering to 33°C reduced, activity of secreted MMP. Switching between 37°C and 33°C altered MMP-9 by 40% ± 3% and MMP-2 by 22% ± 2%. Peripheral circadian clocks did not mediate temperature-driven cycling of MMP secretion because MMP-release oscillations did not persist at constant temperature after 3 to 6 days of alternating temperatures, and temperature cycles did not entrain clock-gene expression in these cells. Furthermore, inhibiting heat shock transcription factor 1, which links temperature and peripheral clock-gene oscillations, inhibited MMP-9 but not MMP-2 temperature-driven MMP cycling. Inhibition of heat-sensitive TRPV1 channels altered total MMP secretion but not temperature-induced modulations. Inhibiting cold-sensitive TRPM-8 channels had no effect. Physiologically relevant temperature oscillations drive fluctuations of secreted MMP-2 and MMP-9 activity in hTM5 cells independent of peripheral clock genes and temperature-sensitive TRP channels. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Ribulose bisphosphate carboxylase activity and a Calvin cycle gene cluster in Sulfobacillus species.

PubMed

Caldwell, Paul E; MacLean, Martin R; Norris, Paul R

2007-07-01

The Calvin-Benson-Bassham (CBB) cycle has been extensively studied in proteobacteria, cyanobacteria, algae and plants, but hardly at all in Gram-positive bacteria. Some characteristics of ribulose bisphosphate carboxylase/oxygenase (RuBisCO) and a cluster of potential CBB cycle genes in a Gram-positive bacterium are described in this study with two species of Sulfobacillus (Gram-positive, facultatively autotrophic, mineral sulfide-oxidizing acidophiles). In contrast to the Gram-negative, iron-oxidizing acidophile Acidithiobacillus ferrooxidans, Sulfobacillus thermosulfidooxidans grew poorly autotrophically unless the CO(2) concentration was enhanced over that in air. However, the RuBisCO of each organism showed similar affinities for CO(2) and for ribulose 1,5-bisphosphate, and similar apparent derepression of activity under CO(2) limitation. The red-type, form I RuBisCO of Sulfobacillus acidophilus was confirmed as closely related to that of the anoxygenic phototroph Oscillochloris trichoides. Eight genes potentially involved in the CBB cycle in S. acidophilus were clustered in the order cbbA, cbbP, cbbE, cbbL, cbbS, cbbX, cbbG and cbbT.

An exploration of Early Childhood Education students’ knowledge and preparation to facilitate physical activity for preschoolers: a cross-sectional study

PubMed Central

2014-01-01

Background Early childhood educators play an important role in influencing preschoolers’ physical activity levels. The current study sought to explore Early Childhood Education (ECE) students’ physical activity-related knowledge and educational experience during their formal training in Ontario. Methods A total of 1,113 ECE students from 20 Ontario Colleges completed the study survey (online or on paper), which examined students’ physical activity course content; awareness of physical activity guidelines; understanding of health-related benefits of physical activity; self-efficacy to facilitate physical activity for preschoolers; self-reported physical activity levels; as well as physical activity-related resource needs. Descriptive statistics and independent samples t-tests were used to analyze the quantitative findings. Results Survey results identified that 72.1% of ECE students had not completed any physical activity/physical education specific courses, while only 28.7% were familiar with, and 2.0% accurately reported, the Canadian Physical Activity Guidelines for the Early Years. Only 10.5% of ECE students reported personal physical activity behaviors consistent with national recommendations for adults (150 minutes/week). ECE students’ mean overall task self-efficacy to facilitate physical activity was 7.37 (SD = 1.64). Self-efficacy was significantly higher (p < .05) when students had taken one or more courses devoted to physical activity/physical education, as well as when students engaged in sufficient physical activity to meet the national guidelines for adults (p < .05). Conclusions The results indicate that the current ECE college curriculum represents an excellent opportunity to provide future childcare providers with enriched physical activity-related training and support, such as physical activity guidelines, workshops, and new ideas for activities. Emphasizing the health benefits of physical activity for adults might be important

Facilitating LOS Debriefings: A Training Manual

NASA Technical Reports Server (NTRS)

McDonnell, Lori K.; Jobe, Kimberly K.; Dismukes, R. Key

1997-01-01

This manual is a practical guide to help airline instructors effectively facilitate debriefings of Line Oriented Simulations (LOS). It is based on a recently completed study of Line Oriented Flight Training (LOFT) debriefings at several U.S. airlines. This manual presents specific facilitation tools instructors can use to achieve debriefing objectives. The approach of the manual is to be flexible so it can be tailored to the individual needs of each airline. Part One clarifies the purpose and objectives of facilitation in the LOS setting. Part Two provides recommendations for clarifying roles and expectations and presents a model for organizing discussion. Part Tree suggests techniques for eliciting active crew participation and in-depth analysis and evaluation. Finally, in Part Four, these techniques are organized according to the facilitation model. Examples of how to effectively use the techniques are provided throughout, including strategies to try when the debriefing objectives are not being fully achieved.

Life cycle study of different constructive solutions for building enclosures.

PubMed

Garcia-Ceballos, Luz; de Andres-Díaz, Jose Ramon; Contreras-Lopez, Miguel A

2018-06-01

The construction sector must advance in a more sustainable way and to achieve this goal, the application of global methodologies is needed. These methodologies should take into account all life stages of a building: planning, design, construction, use and demolition. The quantity and variety of the materials used in building construction condition the buildings' environmental and energy impacts. Life Cycle Assessment offers a standardized framework to evaluate the environmental loads of a product, process or activity. This work aims to demonstrate the feasibility of using Life Cycle Assessment (LCA) to select facilities in the construction sector, which minimize environmental and energy impacts. To facilitate the understanding of the proposed methodology, a comparative LCA is performed, to determine the type of thermal insulating material in a double sheet ceramic façade and its thickness, which allows reducing the environmental impacts associated to the enclosure. The three most used enclosure types used in the city of Malaga (Spain) have been selected for this study. The results show the adequacy of the procedure used. Copyright © 2018 Elsevier B.V. All rights reserved.

Oxygen and the light-dark cycle of nitrogenase activity in two unicellular cyanobacteria.

PubMed

Compaoré, Justine; Stal, Lucas J

2010-01-01

Cyanobacteria capable of fixing dinitrogen exhibit various strategies to protect nitrogenase from inactivation by oxygen. The marine Crocosphaera watsonii WH8501 and the terrestrial Gloeothece sp. PCC6909 are unicellular diazotrophic cyanobacteria that are capable of aerobic nitrogen fixation. These cyanobacteria separate the incompatible processes of oxygenic photosynthesis and nitrogen fixation temporally, confining the latter to the dark. Although these cyanobacteria thrive in fully aerobic environments and can be cultivated diazotrophically under aerobic conditions, the effect of oxygen is not precisely known due to methodological limitations. Here we report the characteristics of nitrogenase activity with respect to well-defined levels of oxygen to which the organisms are exposed, using an online and near real-time acetylene reduction assay combined with sensitive laser-based photoacoustic ethylene detection. The cultures were grown under an alternating 12-12 h light-dark cycle and acetylene reduction was recorded continuously. Acetylene reduction was assayed at 20%, 15%, 10%, 7.5%, 5% and 0% oxygen and at photon flux densities of 30 and 76 mumol m(-2) s(-1) provided at the same light-dark cycle as during cultivation. Nitrogenase activity was predominantly but not exclusively confined to the dark. At 0% oxygen nitrogenase activity in Gloeothece sp. was not detected during the dark and was shifted completely to the light period, while C. watsonii did not exhibit nitrogenase activity at all. Oxygen concentrations of 15% and higher did not support nitrogenase activity in either of the two cyanobacteria. The highest nitrogenase activities were at 5-7.5% oxygen. The highest nitrogenase activities in C. watsonii and Gloeothece sp. were observed at 29 degrees C. At 31 degrees C and above, nitrogenase activity was not detected in C. watsonii while the same was the case at 41 degrees C and above in Gloeothece sp. The differences in the behaviour of nitrogenase activity

The Cycles of Math and Science.

ERIC Educational Resources Information Center

Sumrall, William J.; Rock, David

2002-01-01

Introduces lesson plans on cycles designed for middle school students. Activities include: (1) "Boiling and Evaporation"; (2) "Experimenting with Evaporation"; (3) "Condensation and the Water Cycle"; and (4) "Understanding Cycles". Explains the mathematical applications of cycles. (YDS)

Improved solubilization of activated sludge by ozonation in pressure cycles.

PubMed

Cheng, Chia-Jung; Hong, P K Andy; Lin, Cheng-Fang

2012-05-01

The generation of a large volume of activated sludge (AS) from wastewater treatment has increasingly become a great burden on the environment. Anaerobic digestion is routinely practiced for excess waste sludge; however, the process retention time is long because of kinetic limitation in the hydrolysis step. We tested the feasibility of applying ozone in pressure cycles to enhance the disintegration and solubilization of AS with the goal to prepare them for digestion using reduced ozone dose and contact time. The AS was subjected to repetitive pressure cycles in a closed vessel in which an ozone gas mixture was compressed into the slurry to reach 1040 kPa in the headspace to be followed by rapid venting. For a returned AS with total COD (tCOD) of 8200 mg L(-1), a dose of 0.01 gO(3)g(-1) total suspended solids (TSS) delivered via 20 pressure cycles within 16 min resulted in a 37-fold increase of the sCOD/tCOD ratio (due to increased soluble COD, i.e. sCOD) and a 25% reduction of TSS, in comparison to a dose of 0.08 gO(3)g(-1) TSS via bubbling contact over 15 min that resulted in a 15-fold increase of the sCOD/tCOD ratio and a 12% reduction of TSS. Sludge solubilization was evidenced by increased dissolved contents of total phosphorous (from 10 to 64 mg L(-1)), total nitrogen (from 14 to 120 mg L(-1)), and protein (from <15 to 39 mg L(-1)) in the sludge suspension after treatment, indicating significant solubilization of AS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modifying the hip abduction angle during bridging exercise can facilitate gluteus maximus activity.

PubMed

Kang, Sun-Young; Choung, Sung-Dae; Jeon, Hye-Seon

2016-04-01

To investigate how the erector spinae (ES) and gluteus maximus (GM) muscle activity and the anterior pelvic tilt angle change with different hip abduction angles during a bridging exercise. Twenty healthy participants (10 males and 10 females, aged 21.6 ± 1.6) voluntarily participated in this study. Surface electromyography (EMG) signals were recorded from the ES and GM during bridging at three hip abduction angles: 0°, 15°, and 30°. Simultaneously, the anterior pelvic tilt angle was measured using Image J software. The EMG amplitude of the GM muscle and the GM/ES EMG ratio were greatest at 30° hip abduction, followed by 15° and then 0° hip abduction during the bridging exercise. In contrast, the ES EMG amplitude at 30° hip abduction was significantly lesser than that at 0° and 15° abduction. Additionally, the anterior pelvic tilt angle was significantly lower at 30° hip abduction than at 0° or 15°. Bridging with 30° hip abduction can be recommended as an effective method to selectively facilitate GM muscle activity, minimize compensatory ES muscle activity, and decrease the anterior pelvic tilt angle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Variations in synoptic-scale eddy activity during the life cycles of persistent flow anomalies

NASA Technical Reports Server (NTRS)

Dole, Randall M.; Neilley, Peter P.

1991-01-01

The objective of the study was to identify how synoptic-scale eddy activity varies throughout the life cycles of major scale flow anomalies. In particular, composite analyses of various measures of synoptic-scale eddy activity are constructed, with the composites obtained relative to the onset and termination times of cases typically associated with either blocking or abnormally intense zonal flows. The potential mechanisms that are likely to contribute to the observed changes in eddy behavior are discussed.

A New Real-Time Cycle Slip Detection and Repair Method under High Ionospheric Activity for a Triple-Frequency GPS/BDS Receiver.

PubMed

Liu, Wanke; Jin, Xueyuan; Wu, Mingkui; Hu, Jie; Wu, Yun

2018-02-01

Cycle slip detection and repair is a prerequisite for high-precision global navigation satellite system (GNSS)-based positioning. With the modernization and development of GNSS systems, more satellites are available to transmit triple-frequency signals, which allows the introduction of additional linear combinations and provides new opportunities for cycle slip detection and repair. In this paper, we present a new real-time cycle slip detection and repair method under high ionospheric activity for undifferenced Global Positioning System (GPS)/BeiDou Navigation Satellite System (BDS) triple-frequency observations collected with a single receiver. First, three optimal linearly independent geometry-free pseudorange minus phase combinations are selected to correctly and uniquely determine the cycle slips on the original triple-frequency carrier phase observations. Then, a second-order time-difference algorithm is employed for the pseudorange minus phase combinations to mitigate the impact of between-epoch ionospheric residuals on cycle slip detection, which is especially beneficial under high ionospheric activity. The performance of the approach is verified with static GPS/BDS triple-frequency observations that are collected with a 30 s sampling interval under active ionospheric conditions, and observations are manually inserted with simulated cycle slips. The results show that the method can correctly detect and repair cycle slips at a resolution as small as 1 cycle. Moreover, kinematic data collected from car-driven and airborne experiments are also processed to verify the performance of the method. The experimental results also demonstrate that the method is effective in processing kinematic data.

A New Real-Time Cycle Slip Detection and Repair Method under High Ionospheric Activity for a Triple-Frequency GPS/BDS Receiver

PubMed Central

Liu, Wanke; Wu, Mingkui; Hu, Jie; Wu, Yun

2018-01-01

Cycle slip detection and repair is a prerequisite for high-precision global navigation satellite system (GNSS)-based positioning. With the modernization and development of GNSS systems, more satellites are available to transmit triple-frequency signals, which allows the introduction of additional linear combinations and provides new opportunities for cycle slip detection and repair. In this paper, we present a new real-time cycle slip detection and repair method under high ionospheric activity for undifferenced Global Positioning System (GPS)/BeiDou Navigation Satellite System (BDS) triple-frequency observations collected with a single receiver. First, three optimal linearly independent geometry-free pseudorange minus phase combinations are selected to correctly and uniquely determine the cycle slips on the original triple-frequency carrier phase observations. Then, a second-order time-difference algorithm is employed for the pseudorange minus phase combinations to mitigate the impact of between-epoch ionospheric residuals on cycle slip detection, which is especially beneficial under high ionospheric activity. The performance of the approach is verified with static GPS/BDS triple-frequency observations that are collected with a 30 s sampling interval under active ionospheric conditions, and observations are manually inserted with simulated cycle slips. The results show that the method can correctly detect and repair cycle slips at a resolution as small as 1 cycle. Moreover, kinematic data collected from car-driven and airborne experiments are also processed to verify the performance of the method. The experimental results also demonstrate that the method is effective in processing kinematic data. PMID:29389879

Copper-facilitated Suzuki reactions: application to 2-heterocyclic boronates.

PubMed

Deng, James Z; Paone, Daniel V; Ginnetti, Anthony T; Kurihara, Hideki; Dreher, Spencer D; Weissman, Steven A; Stauffer, Shaun R; Burgey, Christopher S

2009-01-15

The palladium-catalyzed Suzuki-Miyaura reaction has been utilized as one of the most powerful methods for C-C bond formation. However, Suzuki reactions of electron-deficient 2-heterocyclic boronates generally give low conversions and remain challenging. The successful copper(I) facilitated Suzuki coupling of 2-heterocyclic boronates that is broad in scope is reported. Use of this methodology affords greatly enhanced yields of these notoriously difficult couplings. Furthermore, mechanistic investigations suggest a possible role of copper in the catalytic cycle.

Septal serotonin depletion in rats facilitates working memory in the radial arm maze and increases hippocampal high-frequency theta activity.

PubMed

López-Vázquez, Miguel Ángel; López-Loeza, Elisa; Lajud Ávila, Naima; Gutiérrez-Guzmán, Blanca Erika; Hernández-Pérez, J Jesús; Reyes, Yoana Estrada; Olvera-Cortés, María Esther

2014-07-05

Hippocampal theta activity, which is strongly modulated by the septal medial/Broca׳s diagonal band neurons, has been linked to information processing of the hippocampus. Serotonin from the medial raphe nuclei desynchronises hippocampal theta activity, whereas inactivation or a lesion of this nucleus induces continuous and persistent theta activity in the hippocampus. Hippocampal serotonin depletion produces an increased expression of high-frequency theta activity concurrent with the facilitation of place learning in the Morris maze. The medial septum-diagonal band of Broca complex (MS/DBB) has been proposed as a key structure in the serotonin modulation of theta activity. We addressed whether serotonin depletion of the MS/DBB induces changes in the characteristics of hippocampal theta activity and whether the depletion is associated with learning in a working memory spatial task in the radial arm maze. Sprague Dawley rats were depleted of 5HT with the infusion of 5,7-dihydroxytriptamine (5,7-DHT) in MS/DBB and were subsequently trained in the standard test (win-shift) in the radial arm, while the CA1 EEG activity was simultaneously recorded through telemetry. The MS/DBB serotonin depletion induced a low level of expression of low-frequency (4.5-6.5Hz) and a higher expression of high-frequency (6.5-9.5Hz) theta activity concomitant to a minor number of errors committed by rats on the working memory test. Thus, the depletion of serotonin in the MS/DBB caused a facilitator effect on working memory and a predominance of high-frequency theta activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Magnetic activity of red secondaries: clues from the outburst cycle variations of dwarf novae

NASA Astrophysics Data System (ADS)

Chinarova, L. L.

Photometric variations of 6 dwarf novae stars are studied based on the photographic observations from the Odessa, Moscow and Sonneberg plate collections and published visual monitoring data from the AFOEV database (Schweitzer E.: 1993, Bull. AFOEV, 64, 14). The moments of maxima are determined by using the "running parabola" fit (Andronov I.L., 1990, Kinematika Fizika Nebesn. Tel., v.6,,N 6, 87) with automatically determined filter half-width (Andronov I.L., 1997, As.Ap. Suppl., in press). All investigated stars exhibit significant changes not only from cycle-to-cycle, but from season-to-season as well. Secondary decade-scale cycles of smooth variations (Bianchini A., 1990, AJ 99, 1941) and abrupt switchings (Andronov I.L., Shakun L.I., 1990, ASS 169, 237) were interpreted by a solar-type activity of the red dwarf secondary in a binary system and may argue for existence of two different subgroups of the dwarf novae.

Predicting the Sunspot Cycle

NASA Technical Reports Server (NTRS)

Hathaway, David H.

2009-01-01

The 11-year sunspot cycle was discovered by an amateur astronomer in 1844. Visual and photographic observations of sunspots have been made by both amateurs and professionals over the last 400 years. These observations provide key statistical information about the sunspot cycle that do allow for predictions of future activity. However, sunspots and the sunspot cycle are magnetic in nature. For the last 100 years these magnetic measurements have been acquired and used exclusively by professional astronomers to gain new information about the nature of the solar activity cycle. Recently, magnetic dynamo models have evolved to the stage where they can assimilate past data and provide predictions. With the advent of the Internet and open data policies, amateurs now have equal access to the same data used by professionals and equal opportunities to contribute (but, alas, without pay). This talk will describe some of the more useful prediction techniques and reveal what they say about the intensity of the upcoming sunspot cycle.

Impact of repeated dry-wet cycles on soil greenhouse gas emissions, extracellular enzyme activity and nutrient cycling in a temperate forest

NASA Astrophysics Data System (ADS)

Leitner, Sonja; Zimmermann, Michael; Bockholt, Jan; Schartner, Markus; Brugner, Paul; Holtermann, Christian; Zechmeister-Boltenstern, Sophie

2014-05-01

Climate change research predicts that both frequency and intensity of weather extremes such as long drought periods and heavy rainfall events will increase in mid Europe over the next decades. Soil moisture is one of the major factors controlling microbial soil processes, and it has been widely agreed that feedback effects between altered precipitation and changed soil fluxes of the greenhouse gases CO2, CH4 and N2O could intensify climate change. In a field experiment in an Austrian beech forest, we established a precipitation manipulation experiment, which will be conducted for 3 years. We use roofs to exclude rainfall from reaching the forest soil and simulate drought periods, and a sprinkler system to simulate heavy rainfall events. We applied repeated dry-wet cycles in two intensities: one treatment received 6 cycles of 1 month drought followed by 75mm irrigation within 2 hours, and a parallel treatment received 3 cycles of 2 months drought followed by 150mm irrigation within 3 hours. We took soil samples 1 day before, 1 day after and 1 week after rewetting events and analyzed them for soil nutrients and extracellular enzyme activities. Soil fluxes of CO2, N2O and CH4 were constantly monitored with an automated flux chamber system, and environmental parameters were recorded via dataloggers. In addition, we determined fluxes and nutrient concentrations of bulk precipitation, throughfall, stemflow, litter percolate and soil water. Next we plan to analyze soil microbial community composition via PLFAs to investigate microbial stress resistance and resilience, and we will use ultrasonication to measure soil aggregate stability and protection of soil organic matter in stressed and control plots. The results of the first year show that experimental rainfall manipulation has influenced soil extracellular enzymes. Potential phenoloxidase activity was significantly reduced in stressed treatments compared to control plots. All measured hydrolytic enzymes (cellulase

Influence of exercise, walking, cycling, and overall nonexercise physical activity on mortality in Chinese women.

PubMed

Matthews, Charles E; Jurj, Adriana L; Shu, Xiao-Ou; Li, Hong-Lan; Yang, Gong; Li, Qi; Gao, Yu-Tang; Zheng, Wei

2007-06-15

This investigation described the effects of exercise, walking, and cycling for transportation, as well as the effect of overall nonexercise physical activity, on mortality in the Shanghai Women's Health Study (1997-2004). Women without heart disease, stroke, or cancer were followed for an average of 5.7 years (n = 67,143), and there were 1,091 deaths from all causes, 537 deaths from cancer, and 251 deaths from cardiovascular diseases. Information about physical activity and relevant covariates was obtained by interview. Proportional hazards models were used to estimate adjusted hazard ratios and 95% confidence intervals. Exercise and cycling for transportation were both inversely and independently associated with all-cause mortality (p(trend) < 0.05), but walking for transportation was less strongly associated with reduced risk (p(trend) = 0.07). Women reporting no regular exercise but who reported 10 or more metabolic equivalent (MET)-hours/day of nonexercise activity were at 25-50% reduced risk (p(trend) < 0.01) relative to less active women (0-9.9 MET-hours/day). Among women reporting the least nonexercise activity (0-9.9 MET-hours/day) but reporting regular exercise participation, exercise was associated with reduced mortality (hazard ratio = 0.78, 95% confidence interval: 0.62, 0.99). These findings add new evidence that overall physical activity levels are an important determinant of longevity, and that health benefit can be obtained through an active lifestyle, exercise, or combinations of both.

Work-related barriers, facilitators, and strategies of breast cancer survivors working during curative treatment

PubMed Central

Sun, Wenjun; Chen, Karen; Terhaar, Abigail; Wiegmann, Douglas A.; Heidrich, Susan M.; Tevaarwerk, Amye J.; Sesto, Mary E.

2017-01-01

BACKGROUND Research has identified barriers and facilitators affecting cancer survivors’ return to work (RTW) following the end of active treatment (surgery, chemotherapy and/or radiation therapy). However, few studies have focused on barriers and facilitators that cancer survivors experience while working during active treatment. Strategies used by cancer survivors to solve work-related problems during active treatment are underexplored. OBJECTIVE The aim of this study was to describe factors that impact, either positively or negatively, breast cancer survivors’ work activities during active treatment. METHODS Semi-structured, recorded interviews were conducted with 35 breast cancer survivors who worked during active treatment. Transcripts of interviews were analyzed using inductive content analysis to identify themes regarding work-related barriers, facilitators and strategies. RESULTS Barriers identified included symptoms, emotional distress, appearance change, time constraints, work characteristics, unsupportive supervisors and coworkers, family issues and other illness. Facilitators included positive aspects of work, support outside of work, and coworker and supervisor support. Strategies included activities to improve health-related issues and changes to working conditions and tasks. CONCLUSIONS Breast cancer survivors encounter various barriers during active treatment. Several facilitators and strategies can help survivors maintain productive work activities. PMID:28059814

Planetary resonances, bi-stable oscillation modes, and solar activity cycles

NASA Technical Reports Server (NTRS)

Sleeper, H. P., Jr.

1972-01-01

The natural resonance structure of the planets in the solar system yields resonance periods of 11.08 and 180 years. The 11.08 year period is due to resonance of the sidereal periods of the three inner planets. The 180-year period is due to synodic resonances of the four major planets. These periods are also observed in the sunspot time series. The 11-year sunspot cycles from 1 to 19 are separated into categories of positive and negative cycles, Mode 1 and Mode 2 cycles, and typical and anomalous cycles. Each category has a characteristic shape, magnitude, or duration, so that statistical prediction techniques are improved when a cycle can be classified in a given category. These categories provide evidence for bistable modes of solar oscillation. The next minimum is expected in 1977 and the next maximum in 1981 or later. These epoch values are 2.5 years later than those based on typical cycle characteristics.

Long-period intensity pulsations in the solar corona during activity cycle 23

NASA Astrophysics Data System (ADS)

Auchère, F.; Bocchialini, K.; Solomon, J.; Tison, E.

2014-03-01

We report on the detection (10σ) of 917 events of long-period (3 to 16 h) intensity pulsations in the 19.5 nm passband of the SOHO Extreme ultraviolet Imaging Telescope. The data set spans from January 1997 to July 2010, i.e. the entire solar cycle 23 and the beginning of cycle 24. The events can last for up to six days and have relative amplitudes up to 100%. About half of the events (54%) are found to happen in active regions, and 50% of these have been visually associated with coronal loops. The remaining 46% are localized in the quiet Sun. We performed a comprehensive analysis of the possible instrumental artefacts and we conclude that the observed signal is of solar origin. We discuss several scenarios that could explain the main characteristics of the active region events. The long periods and the amplitudes observed rule out any explanation in terms of magnetohydrodynamic waves. Thermal non-equilibrium could produce the right periods, but it fails to explain all the observed properties of coronal loops and the spatial coherence of the events. We propose that moderate temporal variations of the heating term in the energy equation, so as to avoid a thermal non-equilibrium state, could be sufficient to explain those long-period intensity pulsations. The large number of detections suggests that these pulsations are common in active regions. This would imply that the measurement of their properties could provide new constraints on the heating mechanisms of coronal loops. Movies are available in electronic form at http://www.aanda.org

Physiological response to firefighting activities of various work cycles using extended duration and prototype SCBA.

PubMed

Kesler, Richard M; Ensari, Ipek; Bollaert, Rachel E; Motl, Robert W; Hsiao-Wecksler, Elizabeth T; Rosengren, Karl S; Fernhall, Bo; Smith, Denise L; Horn, Gavin P

2018-03-01

Firefighters' self-contained breathing apparatus (SCBA) protects the respiratory system during firefighting but increases the physiological burden. Extended duration SCBA (>30 min) have increased air supply, potentially increasing the duration of firefighting work cycles. To examine the effects of SCBA configuration and work cycle (length and rest), 30 firefighters completed seven trials using different SCBA and one or two bouts of simulated firefighting following work cycles common in the United States. Heart rate, core temperature, oxygen consumption, work output and self-reported perceptions were recorded during all activities. Varying SCBA resulted in few differences in these parameters. However, during a second bout, work output significantly declined while heart rates and core temperatures were elevated relative to a single bout. Thirty seven per cent of the subjects were unable to complete the second bout in at least one of the two-bout conditions. These firefighters had lower fitness and higher body mass than those who completed all assigned tasks. Practitioner Summary: The effects of extended duration SCBA and work/rest cycles on physiological parameters and work output have not been examined. Cylinder size had minimal effects, but extended work cycles with no rest resulted in increased physiological strain and decreased work output. This effect was more pronounced in firefighters with lower fitness.

On the possible relations between solar activities and global seismicity in the solar cycle 20 to 23

NASA Astrophysics Data System (ADS)

Herdiwijaya, Dhani; Arif, Johan; Nurzaman, Muhamad Zamzam; Astuti, Isna Kusuma Dewi

2015-09-01

Solar activities consist of high energetic particle streams, electromagnetic radiation, magnetic and orbital gravitational forces. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle, allow for the above fluctuations. Solar activities are also related to the space weather affecting all planetary atmospheric variability, moreover to the Earth's climate variability. Large extreme space and geophysical events (high magnitude earthquakes, explosive volcanic eruptions, magnetic storms, etc.) are hazards for humankind, infrastructure, economies, technology and the activities of civilization. With a growing world population, and with modern reliance on delicate technological systems, human society is becoming increasingly vulnerable to natural hazardous events. The big question arises to the relation between solar forcing energy to the Earth's global seismic activities. Estimates are needed for the long term occurrence-rate probabilities of these extreme natural hazardous events. We studied connectivity from yearly seismic activities that refer to and sunspot number within the solar cycle 20 to 23 of year 1960 to 2013 (53 years). We found clear evidences that in general high magnitude earthquake events and their depth were related to the low solar activity.

Comprehensive Mass Cytometry Analysis of Cell Cycle, Activation, and Coinhibitory Receptors Expression in CD4 T Cells from Healthy and HIV-Infected Individuals.

PubMed

Corneau, Aurélien; Cosma, Antonio; Even, Sophie; Katlama, Christine; Le Grand, Roger; Frachet, Véronique; Blanc, Catherine; Autran, Brigitte

2017-01-01

Mass cytometry allows large multiplex analysis of cell cycle stages together with differentiation, activation, and exhaustion markers, allowing further assessment of the quiescence status of resting CD4 T cells. Peripheral blood CD4 T lymphocytes from 8 individuals, 4 healthy donors, and 4 HIV-infected on antiretroviral treatment (T) were stained with the same 26 monoclonal antibodies and dyes targeting surface and intracellular markers of differentiation, activation, exhaustion, and cell cycle stages. Samples were run on a CYTOF-2. Patterns of naïve [TN] CD4 T cells strongly differed from all other memory subsets central-memory (CM), transitional-memory (TM), effector-memory (EM), and terminally differentiated RA-expressing (TEMRA) subsets, while stem-cell memory (SCM) and T follicular-helper cells (TfH) were close to CM and TM cells with the highest percentages in cell cycle. EM and TEMRA were the most altered by HIV infection, with an increased frequency of activated and cycling cells. Activation markers and coinhibitory receptor expression differed among cell cycle stages, with HLA-DR fitting better than CD25 or CD38 with cycle, and opposite PD-1 gradients along differentiation and cell cycle. "Resting" DR-CD25- CD4+ T cells contained similar amounts of cells in G1 than the activated DR ± CD25± ones but three fold lower cells in S-G2-M. This broad multiplex mass cytometry analysis demonstrates some subsets of the so-called "resting" CD25-DR- CD4+ T cells contain noticeable amounts of cells into cycle or expressing coinhibitory receptors, opening new avenues for a redefinition of resting peripheral blood CD4 T cells harboring the HIV reservoirs. © 2016 International Clinical Cytometry Society. © 2016 International Clinical Cytometry Society.

Examination of Solar Cycle Statistical Model and New Prediction of Solar Cycle 23

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Wilson, John W.

2000-01-01

Sunspot numbers in the current solar cycle 23 were estimated by using a statistical model with the accumulating cycle sunspot data based on the odd-even behavior of historical sunspot cycles from 1 to 22. Since cycle 23 has progressed and the accurate solar minimum occurrence has been defined, the statistical model is validated by comparing the previous prediction with the new measured sunspot number; the improved sunspot projection in short range of future time is made accordingly. The current cycle is expected to have a moderate level of activity. Errors of this model are shown to be self-correcting as cycle observations become available.

Following a natural experiment of guideline adaptation and early implementation: a mixed-methods study of facilitation

PubMed Central

2012-01-01

Background Facilitation is emerging as an important strategy in the uptake of evidence. However, it is not entirely clear from a practical perspective how facilitation occurs to help move research evidence into nursing practice. The Canadian Partnership Against Cancer, also known as the 'Partnership,' is a Pan-Canadian initiative supporting knowledge translation activity for improved care through guideline use. In this case-series study, five self-identified groups volunteered to use a systematic methodology to adapt existing clinical practice guidelines for Canadian use. With 'Partnership' support, local and external facilitators provided assistance for groups to begin the process by adapting the guidelines and planning for implementation. Methods To gain a more comprehensive understanding of the nature of facilitation, we conducted a mixed-methods study. Specifically, we examined the role and skills of individuals actively engaged in facilitation as well as the actual facilitation activities occurring within the 'Partnership.' The study was driven by and builds upon a focused literature review published in 2010 that examined facilitation as a role and process in achieving evidence-based practice in nursing. An audit tool outlining 46 discrete facilitation activities based on results of this review was used to examine the facilitation noted in the documents (emails, meeting minutes, field notes) of three nursing-related cases participating in the 'Partnership' case-series study. To further examine the concept, six facilitators were interviewed about their practical experiences. The case-audit data were analyzed through a simple content analysis and triangulated with participant responses from the focus group interview to understand what occurred as these cases undertook guideline adaptation. Results The analysis of the three cases revealed that almost all of the 46 discrete, practical facilitation activities from the literature were evidenced. Additionally, case

Impaired in vivo mitochondrial Krebs cycle activity after myocardial infarction assessed using hyperpolarized magnetic resonance spectroscopy.

PubMed

Dodd, Michael S; Atherton, Helen J; Carr, Carolyn A; Stuckey, Daniel J; West, James A; Griffin, Julian L; Radda, George K; Clarke, Kieran; Heather, Lisa C; Tyler, Damian J

2014-11-01

Myocardial infarction (MI) is one of the leading causes of heart failure. An increasing body of evidence links alterations in cardiac metabolism and mitochondrial function with the progression of heart disease. The aim of this work was to, therefore, follow the in vivo mitochondrial metabolic alterations caused by MI, thereby allowing a greater understanding of the interplay between metabolic and functional abnormalities. Using hyperpolarized carbon-13 ((13)C)-magnetic resonance spectroscopy, in vivo alterations in mitochondrial metabolism were assessed for 22 weeks after surgically induced MI with reperfusion in female Wister rats. One week after MI, there were no detectable alterations in in vivo cardiac mitochondrial metabolism over the range of ejection fractions observed (from 28% to 84%). At 6 weeks after MI, in vivo mitochondrial Krebs cycle activity was impaired, with decreased (13)C-label flux into citrate, glutamate, and acetylcarnitine, which correlated with the degree of cardiac dysfunction. These changes were independent of alterations in pyruvate dehydrogenase flux. By 22 weeks, alterations were also seen in pyruvate dehydrogenase flux, which decreased at lower ejection fractions. These results were confirmed using in vitro analysis of enzyme activities and metabolomic profiles of key intermediates. The in vivo decrease in Krebs cycle activity in the 6-week post-MI heart may represent an early maladaptive phase in the metabolic alterations after MI in which reductions in Krebs cycle activity precede a reduction in pyruvate dehydrogenase flux. Changes in mitochondrial metabolism in heart disease are progressive and proportional to the degree of cardiac impairment. © 2014 American Heart Association, Inc.

Impaired In Vivo Mitochondrial Krebs Cycle Activity After Myocardial Infarction Assessed Using Hyperpolarized Magnetic Resonance Spectroscopy

PubMed Central

Carr, Carolyn A.; Stuckey, Daniel J.; West, James A.; Griffin, Julian L.; Radda, George K.; Clarke, Kieran; Heather, Lisa C.; Tyler, Damian J.

2015-01-01

Background Myocardial infarction (MI) is one of the leading causes of heart failure. An increasing body of evidence links alterations in cardiac metabolism and mitochondrial function with the progression of heart disease. The aim of this work was to, therefore, follow the in vivo mitochondrial metabolic alterations caused by MI, thereby allowing a greater understanding of the interplay between metabolic and functional abnormalities. Methods and Results Using hyperpolarized carbon-13 (13C)-magnetic resonance spectroscopy, in vivo alterations in mitochondrial metabolism were assessed for 22 weeks after surgically induced MI with reperfusion in female Wister rats. One week after MI, there were no detectable alterations in in vivo cardiac mitochondrial metabolism over the range of ejection fractions observed (from 28% to 84%). At 6 weeks after MI, in vivo mitochondrial Krebs cycle activity was impaired, with decreased 13C-label flux into citrate, glutamate, and acetylcarnitine, which correlated with the degree of cardiac dysfunction. These changes were independent of alterations in pyruvate dehydrogenase flux. By 22 weeks, alterations were also seen in pyruvate dehydrogenase flux, which decreased at lower ejection fractions. These results were confirmed using in vitro analysis of enzyme activities and metabolomic profiles of key intermediates. Conclusions The in vivo decrease in Krebs cycle activity in the 6-week post-MI heart may represent an early maladaptive phase in the metabolic alterations after MI in which reductions in Krebs cycle activity precede a reduction in pyruvate dehydrogenase flux. Changes in mitochondrial metabolism in heart disease are progressive and proportional to the degree of cardiac impairment. PMID:25201905

Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae.

PubMed

Ioannou, Petros; Andrianaki, Aggeliki; Akoumianaki, Tonia; Kyrmizi, Irene; Albert, Nathaniel; Perlin, David; Samonis, George; Kontoyiannis, Dimitrios P; Chamilos, Georgios

2015-12-07

The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P < 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery to Aspergillus hyphae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

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

Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O., E-mail: pustylnyak@ngs.ru

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CARmore » and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their

High-frequency thermal-electrical cycles for pyroelectric energy conversion

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

Bhatia, Bikram; Damodaran, Anoop R.; Cho, Hanna

2014-11-21

We report thermal to electrical energy conversion from a 150 nm thick BaTiO{sub 3} film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10{sup 5 }kV/cm-s, and temperature change rates as high as 6 × 10{sup 5 }K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cyclesmore » are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems.« less

The Relative Abundance and Transcriptional Activity of Marine Sponge-Associated Microorganisms Emphasizing Groups Involved in Sulfur Cycle.

PubMed

Jensen, Sigmund; Fortunato, Sofia A V; Hoffmann, Friederike; Hoem, Solveig; Rapp, Hans Tore; Øvreås, Lise; Torsvik, Vigdis L

2017-04-01

During the last decades, our knowledge about the activity of sponge-associated microorganisms and their contribution to biogeochemical cycling has gradually increased. Functional groups involved in carbon and nitrogen metabolism are well documented, whereas knowledge about microorganisms involved in the sulfur cycle is still limited. Both sulfate reduction and sulfide oxidation has been detected in the cold water sponge Geodia barretti from Korsfjord in Norway, and with specimens from this site, the present study aims to identify extant versus active sponge-associated microbiota with focus on sulfur metabolism. Comparative analysis of small subunit ribosomal RNA (16S rRNA) gene (DNA) and transcript (complementary DNA (cDNA)) libraries revealed profound differences. The transcript library was predominated by Chloroflexi despite their low abundance in the gene library. An opposite result was found for Acidobacteria. Proteobacteria were detected in both libraries with representatives of the Alpha- and Gammaproteobacteria related to clades with presumably thiotrophic bacteria from sponges and other marine invertebrates. Sequences that clustered with sponge-associated Deltaproteobacteria were remotely related to cultivated sulfate-reducing bacteria. The microbes involved in sulfur cycling were identified by the functional gene aprA (adenosine-5'-phosphosulfate reductase) and its transcript. Of the aprA sequences (DNA and cDNA), 87 % affiliated with sulfur-oxidizing bacteria. They clustered with Alphaproteobacteria and with clades of deep-branching Gammaproteobacteria. The remaining sequences clustered with sulfate-reducing Archaea of the phylum Euryarchaeota. These results indicate an active role of yet uncharacterized Bacteria and Archaea in the sponge's sulfur cycle.

GPR30 activation improves memory and facilitates DHPG-induced LTD in the hippocampal CA3 of middle-aged mice.

PubMed

Xu, Wen; Cao, Jian; Zhou, Yan; Wang, Lina; Zhu, Guoqi

2018-03-01

Reduced estrogen levels and decreased expression of related receptors are typical cerebral features of aging. The G protein-coupled estrogen receptor 1 (GPER1, also known as GPR30) is considered a novel therapeutic target for neurodegenerative diseases. In this study, we demonstrated that hippocampal GPR30 expression was reduced in middle-aged mice compared with young adult mice. GPR30 agonist G1 improved both fear and spatial memory in both male and female middle-aged mice, but not in young adult mice, which were blocked by the GPR30 antagonist G15. Interestingly, a group I metabotropic glutamate receptor (mGluR) agonist, 3,5-dihydroxyphenylglycine (DHPG)-induced long-term depression (LTD) in mossy fiber-cornu ammonis 3 (MF-CA3) synapses but not Schaffer collateral-CA1 (SC-CA1) synapses was facilitated in brain slices from G1-treated middle-aged mice. Long-term potentiation (LTP) in SC-CA1 synapses was not affected in slices from G1-treated mice. The effects of GPR30 activation on memory and DHPG-LTD in MF-CA3 synapses were further confirmed by viral expression of GPR30 in the CA3. The regulation of hippocampal synaptic plasticity by G1 treatment might be related to brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling, as G15 also blocked G1-induced activation of the BDNF-TrkB pathway. Moreover, we found that DHPG triggered GluA internalization in slices from G1-treated mice but not control mice. Pharmacological experiments showed that G1-mediated facilitation of DHPG-induced LTD in MF-CA3 synapses was dependent on protein kinase B (Akt), mammalian target of rapamycin (mTor), and TrkB signaling. In conclusion, our results indicate that GPR30 activation improves memory in middle-aged mice, likely through facilitating synaptic plasticity in the CA3. This study provides novel evidence that GPR30 activation can improve memory in middle-aged animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Patients with schizophrenia activate behavioural intentions facilitated by counterfactual reasoning.

PubMed

Contreras, Fernando; Albacete, Auria; Tebé, Cristian; Benejam, Bessy; Caño, Agnes; Menchón, José Manuel

2017-01-01

The main variables assessed were: answer to complete a target task (wrong or correctly), and percentage gain in the reaction time (RT) to complete a target task correctly depending on whether the prime was a counterfactual or a neutral-control cue. These variables were assessed in 37 patients with schizophrenia and 37 healthy controls. Potential associations with clinical status and socio-demographic characteristics were also explored. When a counterfactual prime was presented, the probability of giving an incorrect answer was lower for the entire sample than when a neutral prime was presented (OR 0.58; CI 95% 0.42 to 0.79), but the schizophrenia patients showed a higher probability than the controls of giving an incorrect answer (OR 3.89; CI 95% 2.0 to 7.6). Both the schizophrenia patients and the controls showed a similar percentage gain in RT to a correct answer of 8%. Challenging the results of previous research, our findings suggest a normal activation of behavioural intentions facilitated by CFT in schizophrenia. Nevertheless, the patients showed more difficulty than the controls with the task, adding support to the concept of CFT as a potential new target for consideration in future therapeutic approaches for this illness.

Research and Technology Activities Supporting Closed-Brayton-Cycle Power Conversion System Development

NASA Technical Reports Server (NTRS)

Barrett, Michael J.

2004-01-01

The elements of Brayton technology development emphasize power conversion system risk mitigation. Risk mitigation is achieved by demonstrating system integration feasibility, subsystem/component life capability (particularly in the context of material creep) and overall spacecraft mass reduction. Closed-Brayton-cycle (CBC) power conversion technology is viewed as relatively mature. At the 2-kWe power level, a CBC conversion system Technology Readiness Level (TRL) of six (6) was achieved during the Solar Dynamic Ground Test Demonstration (SD-GTD) in 1998. A TRL 5 was demonstrated for 10 kWe-class CBC components during the development of the Brayton Rotating Unit (BRU) from 1968 to 1976. Components currently in terrestrial (open cycle) Brayton machines represent TRL 4 for similar uses in 100 kWe-class CBC space systems. Because of the baseline component and subsystem technology maturity, much of the Brayton technology task is focused on issues related to systems integration. A brief description of ongoing technology activities is given.

Rock Cycle Roulette.

ERIC Educational Resources Information Center

Schmidt, Stan M.; Palmer, Courtney

2000-01-01

Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

Time course of serum inhibitory activity for facilitated allergen-IgE binding during bee venom immunotherapy in children.

PubMed

Varga, E-M; Francis, J N; Zach, M S; Klunker, S; Aberer, W; Durham, S R

2009-09-01

Immunotherapy for bee venom allergy is effective and provides long-term protection. Venom-specific IgG4 levels are increased but with no correlation with clinical improvement. Following grass pollen immunotherapy, elevation of antigen-specific IgG4 is accompanied by increases in IgG-dependent serum inhibitory activity for IgE-facilitated binding of allergen-IgE complexes to B cells. As this 'functional' assay of inhibitory antibodies may be more predictive of clinical efficacy, we investigated the time course of serum inhibitory activity for IgE-facilitated antigen binding during venom immunotherapy (VIT) in children and following 2 years of VIT withdrawal. Ten bee venom-allergic children (mean age: 9.3 years; m/f, 7/3) with moderate to severe allergic reactions to bee stings received VIT. A separate group of seven children (mean age: 14 years; m/f, 5/2) were investigated 2 years after VIT withdrawal. Ten age- and gender-matched children served as non-allergic controls. Allergen-specific serum IgG4 and IgE levels were measured by ELISA at baseline, after 2 years of VIT and 2 years after VIT withdrawal. Serum inhibitory activity was assessed using the facilitated-allergen binding (FAB) assay. Sera obtained during VIT significantly inhibited allergen-IgE binding to B-cells (pre-treatment=104+/-23%; 2 years=46+/-15%; P<0.001) when compared with sera obtained after treatment withdrawal and sera from normal controls. In parallel to FAB inhibition during VIT, significantly higher IgG4 levels were noted after immunotherapy (pre-treatment=8.6+/-2.3 AU; 2 years=26.7+/-3.5 AU; P<0.001) compared with those observed after withdrawal and in the controls. In contrast, progressively lower IgE concentrations were observed compared with pre-treatment (44+/-7 AU) in sera obtained after 2 years of VIT (25+/-5 AU; P<0.01) and 2 years following the withdrawal of VIT (10+/-3 AU; P<0.05). In contrast to grass pollen immunotherapy, the persistent decline in venom-specific IgE levels

Methotrexate increases expression of cell cycle checkpoint genes via Jun-N-terminal kinase activation

PubMed Central

Spurlock, Charles F.; Tossberg, John T.; Fuchs, Howard A.; Olsen, Nancy J.; Aune, Thomas M.

2011-01-01

Objective To assess defects in expression of critical cell cycle checkpoint genes and proteins in subjects with rheumatoid arthritis relative to presence or absence of methotrexate medication and assess the role of Jun N-terminal kinase in methotrexate induction of these genes. Methods Flow cytometry analysis was used to quantify changes in intracellular proteins, measure reactive oxygen species (ROS), and determine apoptosis in different lymphoid populations. Quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR) was employed to determine changes in cell cycle checkpoint target genes. Results RA subjects express lower baseline levels of MAPK9, TP53, CDKN1A, CDKN1B, CHEK2, and RANGAP1 messenger RNA (mRNA) and total JNK protein. MAPK9, TP53, CDKN1A, and CDKN1B mRNA expression, but not CHEK2, and RANGAP1, is higher in patients on low-dose MTX therapy. Further, JNK levels inversely correlate with CRP levels in RA patients. In tissue culture, MTX induces expression of both p53 and p21 by JNK2 and JNK1-dependent mechanisms, respectively, while CHEK2 and RANGAP1 are not induced by MTX. MTX also induces ROS production, JNK activation, and sensitivity to apoptosis in activated T cells. Supplementation with tetrahydrobiopterin blocks these MTX-mediated effects. Conclusions Our findings support the notion that MTX restores some, but not all of the proteins contributing to cell cycle checkpoint deficiencies in RA T cells by a JNK dependent pathway. PMID:22183962

Substrate-Induced Facilitated Dissociation of the Competitive Inhibitor from the Active Site of O-Acetyl Serine Sulfhydrylase Reveals a Competitive-Allostery Mechanism.

PubMed

Singh, Appu Kumar; Ekka, Mary Krishna; Kaushik, Abhishek; Pandya, Vaibhav; Singh, Ravi P; Banerjee, Shrijita; Mittal, Monica; Singh, Vijay; Kumaran, S

2017-09-19

By classical competitive antagonism, a substrate and competitive inhibitor must bind mutually exclusively to the active site. The competitive inhibition of O-acetyl serine sulfhydrylase (OASS) by the C-terminus of serine acetyltransferase (SAT) presents a paradox, because the C-terminus of SAT binds to the active site of OASS with an affinity that is 4-6 log-fold (10 4 -10 6 ) greater than that of the substrate. Therefore, we employed multiple approaches to understand how the substrate gains access to the OASS active site under physiological conditions. Single-molecule and ensemble approaches showed that the active site-bound high-affinity competitive inhibitor is actively dissociated by the substrate, which is not consistent with classical views of competitive antagonism. We employed fast-flow kinetic approaches to demonstrate that substrate-mediated dissociation of full length SAT-OASS (cysteine regulatory complex) follows a noncanonical "facilitated dissociation" mechanism. To understand the mechanism by which the substrate induces inhibitor dissociation, we resolved the crystal structures of enzyme·inhibitor·substrate ternary complexes. Crystal structures reveal a competitive allosteric binding mechanism in which the substrate intrudes into the inhibitor-bound active site and disengages the inhibitor before occupying the site vacated by the inhibitor. In summary, here we reveal a new type of competitive allosteric binding mechanism by which one of the competitive antagonists facilitates the dissociation of the other. Together, our results indicate that "competitive allostery" is the general feature of noncanonical "facilitated/accelerated dissociation" mechanisms. Further understanding of the mechanistic framework of "competitive allosteric" mechanism may allow us to design a new family of "competitive allosteric drugs/small molecules" that will have improved selectivity and specificity as compared to their competitive and allosteric counterparts.

Induction of Apoptosis and Antiproliferative Activity of Naringenin in Human Epidermoid Carcinoma Cell through ROS Generation and Cell Cycle Arrest

PubMed Central

Jafri, Asif; Ahmad, Sheeba; Afzal, Mohammad; Arshad, Md

2014-01-01

A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS) initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (p<0.01) with a concomitant increase in nuclear condensation and DNA fragmentation in a dose dependent manner. The intracellular ROS generation assay showed statistically significant (p<0.001) dose-related increment in ROS production for naringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation. PMID:25330158

A dual transcriptional reporter and CDK-activity sensor marks cell cycle entry and progression in C. elegans

PubMed Central

van Rijnberk, Lotte M.; van der Horst, Suzanne E. M.; van den Heuvel, Sander; Ruijtenberg, Suzan

2017-01-01

Development, tissue homeostasis and tumor suppression depend critically on the correct regulation of cell division. Central in the cell division process is the decision whether to enter the next cell cycle and commit to going through the S and M phases, or to remain temporarily or permanently arrested. Cell cycle studies in genetic model systems could greatly benefit from visualizing cell cycle commitment in individual cells without the need of fixation. Here, we report the development and characterization of a reporter to monitor cell cycle entry in the nematode C. elegans. This reporter combines the mcm-4 promoter, to reveal Rb/E2F-mediated transcriptional control, and a live-cell sensor for CDK-activity. The CDK sensor was recently developed for use in human cells and consists of a DNA Helicase fragment fused to eGFP. Upon phosphorylation by CDKs, this fusion protein changes in localization from the nucleus to the cytoplasm. The combined regulation of transcription and subcellular localization enabled us to visualize the moment of cell cycle entry in dividing seam cells during C. elegans larval development. This reporter is the first to reflect cell cycle commitment in C. elegans and will help further genetic studies of the mechanisms that underlie cell cycle entry and exit. PMID:28158315

[Suppression of cycling activity in sheep using parenteral progestagen treatment].

PubMed

Janett, F; Camponovo, L; Lanker, U; Hässig, M; Thun, R

2004-03-01

The objective of this study was to evaluate the effect of two synthetic progestagen preparations Chlormadinone acetate (CAP, Chronosyn, Veterinaria AG Zürich) and Medroxyprogesterone acetate (MPA, Nadigest, G Streuli & Co. Uznach) on cycling activity and fertility in sheep. A flock of 28 non pregnant white alpine sheep was randomly divided into three groups, A (n = 10), B (n = 9) and C (n = 9). During a period of 4 weeks the cycling activity was confirmed by blood progesterone analysis. Thereafter, the animals of group A were treated with 50 mg CAP, those of group B with 140 mg MPA and those of group C with physiological saline solution. All injections were given intramuscularly. Suppression of endogenous progesterone secretion lasted from 28 to 49 days (mean = 39 days) in group A and from 42 to 70 days (mean = 50 days) in group B. The synchronization effect of both preparations was unsatisfactory as the occurrence of first estrus was distributed over a period of 3 weeks in group A and 4 weeks in group B. These findings could also be confirmed by the lambing period which lasted 52 days in group A and 36 days in group B. Control animals lambed within 9 days due to the synchronizing effect of the ram. The first fertile estrus was observed 36 days (group A) and 45 days (group B) after the treatment. In group A all 10 animals and in groups B and C 8 of 9 ewes each became pregnant. Parenteral progestagen application with CAP and MPA is a simple, safe and reversible method of estrus suppression in the sheep. The minimal suppressive duration of 4 (CAP) and 5 weeks (MPA) is not sufficient when a period of 3 months (alpine pasture period) is desired.

ENZYME ACTIVITIES DURING THE ASEXUAL CYCLE OF NEUROSPORA CRASSA

PubMed Central

Stine, G. J.

1968-01-01

Three enzymes, (a) nicotinamide adenine diphosphate-dependent glutamic dehydrogenase (NAD enzyme), (b) nictoinamide adenine triphosphate-dependent glutamic dehydrogenase (NADP enzyme), and (c) nicotinamide-adenine dinucleotidase (NADase), were measured in separate extracts of Neurospora crassa grown in Vogel's medium N and medium N + glutamate. Specific activities and total units per culture of each enzyme were determined at nine separate intervals phased throughout the asexual cycle. The separate dehydrogenases were lowest in the conidia, increased slowly during germination, and increased rapidly during logarithmic mycelial growth. The amounts of these enzymes present during germination were small when compared with those found later during the production of the conidiophores. The NAD enzyme may be necessary for pregermination synthesis. The NADP-enzyme synthesis was associated with the appearance of the germ tube. Although higher levels of the dehydrogenases in the conidiophores resulted in more enzyme being found in the differentiated conidia, the rate of germination was uneffected. The greatest activity for the NADase enzyme was associated with the conidia, early phases of germination, and later production of new conidia. NADase decreased significantly with the onset of logarithmic growth, remained low during the differentiation of conidiophores, and increased considerably as the conidiophores aged. PMID:4384627

Longitudinal associations of active commuting with body mass index.

PubMed

Mytton, Oliver Tristan; Panter, Jenna; Ogilvie, David

2016-09-01

To investigate the longitudinal associations between active commuting (walking and cycling to work) and body mass index (BMI). We used self-reported data on height, weight and active commuting from the Commuting and Health in Cambridge study (2009 to 2012; n=809). We used linear regression to test the associations between: a) maintenance of active commuting over one year and BMI at the end of that year; and b) change in weekly time spent in active commuting and change in BMI over one year. After adjusting for sociodemographic variables, other physical activity, physical wellbeing and maintenance of walking, those who maintained cycle commuting reported a lower BMI on average at one year follow-up (1.14kg/m(2), 95% CI: 0.30 to 1.98, n=579) than those who never cycled to work. No significant association remained after adjustment for baseline BMI. No significant associations were observed for maintenance of walking. An increase in walking was associated with a reduction in BMI (0.32kg/m(2), 95% CI: 0.03 to 0.62, n=651, after adjustment for co-variates and baseline BMI) only when restricting the analysis to those who did not move. No other significant associations between changes in weekly time spent walking or cycling on the commute and changes in BMI were observed. This work provides further evidence of the contribution of active commuting, particularly cycling, to preventing weight gain or facilitating weight loss. The findings may be valuable for employees choosing how to commute and engaging employers in the promotion of active travel. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Structure and function of Hip, an attenuator of the Hsp70 chaperone cycle.

PubMed

Li, Zhuo; Hartl, F Ulrich; Bracher, Andreas

2013-08-01

The Hsp70-interacting protein, Hip, cooperates with the chaperone Hsp70 in protein folding and prevention of aggregation. Hsp70 interacts with non-native protein substrates in an ATP-dependent reaction cycle regulated by J-domain proteins and nucleotide exchange factors (NEFs). Hip is thought to delay substrate release by slowing ADP dissociation from Hsp70. Here we present crystal structures of the dimerization domain and the tetratricopeptide repeat (TPR) domain of rat Hip. As shown in a cocrystal structure, the TPR core of Hip interacts with the Hsp70 ATPase domain through an extensive interface, to form a bracket that locks ADP in the binding cleft. Hip and NEF binding to Hsp70 are mutually exclusive, and thus Hip attenuates active cycling of Hsp70-substrate complexes. This mechanism explains how Hip enhances aggregation prevention by Hsp70 and facilitates transfer of specific proteins to downstream chaperones or the proteasome.

Helicobacter pylori Induced Phosphatidylinositol-3-OH Kinase/mTOR Activation Increases Hypoxia Inducible Factor-1α to Promote Loss of Cyclin D1 and G0/G1 Cell Cycle Arrest in Human Gastric Cells.

PubMed

Canales, Jimena; Valenzuela, Manuel; Bravo, Jimena; Cerda-Opazo, Paulina; Jorquera, Carla; Toledo, Héctor; Bravo, Denisse; Quest, Andrew F G

2017-01-01

Helicobacter pylori ( H. pylori ) is a human gastric pathogen that has been linked to the development of several gastric pathologies, such as gastritis, peptic ulcer, and gastric cancer. In the gastric epithelium, the bacterium modifies many signaling pathways, resulting in contradictory responses that favor both proliferation and apoptosis. Consistent with such observations, H. pylori activates routes associated with cell cycle progression and cell cycle arrest. H. pylori infection also induces the hypoxia-induced factor HIF-1α, a transcription factor known to promote expression of genes that permit metabolic adaptation to the hypoxic environment in tumors and angiogenesis. Recently, however, also roles for HIF-1α in the repair of damaged DNA and inhibition of gene expression were described. Here, we investigated signaling pathways induced by H. pylori in gastric cells that favor HIF-1α expression and the consequences thereof in infected cells. Our results revealed that H. pylori promoted PI3K/mTOR-dependent HIF-1α induction, HIF-1α translocation to the nucleus, and activity as a transcription factor as evidenced using a reporter assay. Surprisingly, however, transcription of known HIF-1α effector genes evaluated by qPCR analysis, revealed either no change (LDHA and GAPDH), statistically insignificant increases SLC2A1 (GLUT-1) or greatly enhance transcription (VEGFA), but in an HIF-1α-independent manner, as quantified by PCR analysis in cells with shRNA-mediated silencing of HIF-1α. Instead, HIF-1α knockdown facilitated G1/S progression and increased Cyclin D1 protein half-life, via a post-translational pathway. Taken together, these findings link H. pylori -induced PI3K-mTOR activation to HIF-1α induced G0/G1 cell cycle arrest by a Cyclin D1-dependent mechanism. Thus, HIF-1α is identified here as a mediator between survival and cell cycle arrest signaling activated by H. pylori infection.

Remarkable cycle-activated capacity increasing in onion-like carbon nanospheres as lithium battery anode material

NASA Astrophysics Data System (ADS)

Dong, Jiajun; Zhang, Tong; Zhang, Dong; Zhang, Weiwei; Zhang, Huafang; Liu, Ran; Yao, Mingguang; Liu, Bingbing

2017-01-01

Onion-like carbon nanospheres (OCNSs) with an average diameter of 43 nm were produced on a large scale via a combustion method and examined as an anode material for lithium ion batteries. The OCNSs exhibit a remarkable electrochemical cycling behavior and a capacity much higher than that of graphite. The capacity increases significantly with increasing charge-discharge cycles and reaches a value of 178% of the initial value (from 586 mA h g-1to 1045 mA h g-1) after 200 cycles. Further investigation provides unambiguous experimental evidence that such a remarkable capacity increase is related to the stable onion-like structure of the OCNSs and to the existence of large numbers of disordered/short graphitic fragments, which gradually provide more active sites for Li ion storage. The unique electrochemical performance of OCNSs provides a new way to design a high-performance anode material for rechargeable batteries.

On the nature of extraversion: variation in conditioned contextual activation of dopamine-facilitated affective, cognitive, and motor processes

PubMed Central

Depue, Richard A.; Fu, Yu

2013-01-01

Research supports an association between extraversion and dopamine (DA) functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP) with a particular laboratory context (Paired group), a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context) served as controls. Conditioned contextual facilitation was assessed by (i) presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii) measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups). Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that predict reward

Autonomy and integration in complex parasite life cycles.