Characterization and effect of light on the plasma membrane H(+) -ATPase of bean leaves

NASA Technical Reports Server (NTRS)

Linnemeyer, P. A.; Van Volkenburgh, E.; Cleland, R. E.

1990-01-01

Proton excretion from bean (Phaseolus vulgaris L.) leaf cells is increased by bright white light. To test whether this could be due, at least in part, to an increase in plasma membrane (PM) ATPase activity, PM vesicles were isolated from primary leaves by phase partitioning and used to characterize PM ATPase activity and changes in response to light. ATPase activity was characterized as magnesium ion dependent, vanadate sensitive, and slightly stimulated by potassium chloride. The pH optimum was 6.5, the Km was approximately 0.30 millimolar ATP, and the activity was about 60% latent. PM vesicles were prepared from leaves of plants grown for 11 days in dim red light (growing slowly) or grown for 10 days in dim red light and then transferred to bright white-light for 1 day (growing rapidly). For both light treatments, ATPase specific activity was approximately 600 to 700 nanomoles per milligram protein per minute, and the latency, Km, and sensitivity to potassium chloride were also similar. PM vesicles from plants grown in complete darkness, however, exhibited a twofold greater specific activity. We conclude that the promotion of leaf growth and proton excretion by bright white light is not due to an increase in ATPase specific activity. Light does influence ATPase activity, however; both dim red light and bright white light decreased the ATPase specific activity by nearly 50% as compared with dark-grown leaves.

Consequences of partial and severe dopaminergic lesion on basal ganglia oscillatory activity and akinesia.

PubMed

Tseng, Kuei Y; Kargieman, Lucila; Gacio, Sebastian; Riquelme, Luis A; Murer, M Gustavo

2005-11-01

Severe chronic dopamine (DA) depletion increases the proportion of neurons in the basal ganglia that fire rhythmic bursts of action potential (LFO units) synchronously with the cortical oscillations. Here we report on how different levels of mesencephalic DA denervation affect substantia nigra pars reticulata (SNpr) neuronal activity in the rat and its relationship to akinesia (stepping test). Chronic nigrostriatal lesion induced with 0 (control group), 4, 6 or 8 microg of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle resulted in a dose-dependent decrease of tyrosine hydroxylase positive (TH+) neurons in the SN and ventral tegmental area (VTA). Although 4 microg of 6-OHDA reduced the number of TH+ neurons in the SN by approximately 60%, both stepping test performance and SNpr neuronal activity remained indistinguishable from control animals. By contrast, animals that received 6 microg of 6-OHDA showed a marked reduction of TH+ cells in the SN ( approximately 75%) and VTA ( approximately 55%), a significant stepping test deficit and an increased proportion of LFO units. These changes were not dramatically enhanced with 8 microg 6-OHDA, a dose that induced an extensive DA lesion (> 95%) in the SN and approximately 70% reduction of DA neurons in the VTA. These results suggest a threshold level of DA denervation for both the appearance of motor deficits and LFO units. Thus, the presence of LFO activity in the SNpr is not related to a complete nigrostriatal DA neuron depletion (ultimate stage parkinsonism); instead, it may reflect a functional disruption of cortico-basal ganglia dynamics associated with clinically relevant stages of the disease.

Atomic force microscope studies of the fusion of floating lipid bilayers.

PubMed

Abdulreda, Midhat H; Moy, Vincent T

2007-06-15

This study investigated the fusion of apposing floating bilayers of egg L-alpha-phosphatidylcholine (egg PC) or 1,2-dimyristoyl-sn-glycero-3-phosphocholine. Atomic force microscope measurements of fusion forces under different compression rates were acquired to reveal the energy landscape of the fusion process under varied lipid composition and temperature. Between compression rates of approximately 1000 and approximately 100,000 pN/s, applied forces in the range from approximately 100 to approximately 500 pN resulted in fusion of floating bilayers. Our atomic force microscope measurements indicated that one main energy barrier dominated the fusion process. The acquired dynamic force spectra were fit with a simple model based on the transition state theory with the assumption that the fusion activation potential is linear. A significant shift in the energy landscape was observed when bilayer fluidity and composition were modified, respectively, by temperature and different cholesterol concentrations (15% < or = chol < or = 25%). Such modifications resulted in a more than twofold increase in the width of the fusion energy barrier for egg PC and 1,2-dimyristoyl-sn-glycero-3-phosphocholine floating bilayers. The addition of 25% cholesterol to egg PC bilayers increased the activation energy by approximately 1.0 k(B)T compared with that of bilayers with egg PC alone. These results reveal that widening of the energy barrier and consequently reduction in its slope facilitated membrane fusion.

Neural correlates of genetically abnormal social cognition in Williams syndrome.

PubMed

Meyer-Lindenberg, Andreas; Hariri, Ahmad R; Munoz, Karen E; Mervis, Carolyn B; Mattay, Venkata S; Morris, Colleen A; Berman, Karen Faith

2005-08-01

Williams-Beuren syndrome (WBS), caused by a microdeletion of approximately 21 genes on chromosome 7q11.23, is characterized by unique hypersociability combined with increased non-social anxiety. Using functional neuroimaging, we found reduced amygdala activation in individuals with WBS for threatening faces but increased activation for threatening scenes, relative to matched normal controls. Activation and interactions of prefrontal regions linked to amygdala, especially orbitofrontal cortex, were abnormal, suggesting a genetically controlled neural circuitry for regulating human social behavior.

Engineering Students at Typically Invisible Transition Points: A Focus on Admissions and the Sophomore Year

ERIC Educational Resources Information Center

Holloway, Elizabeth M.

2013-01-01

As of 2012, women are approximately 19% of all engineering undergraduate students nationally (American Society for Engineering Education, 2012). Women's representation in engineering has not changed significantly over the last 20 years, despite increased attention, increased funding, and increased programmatic activities intended to encourage more…

Tracking microbial impact on crop production

USDA-ARS?s Scientific Manuscript database

One of the benefits of no-till systems is that activity of the soil microbial community increases. Producers gain an array of improvements in their production systems due to enhanced microbial functioning. For example, corn yield can increase approximately 25% with the same inputs with more microb...

Characteristics of travel to and from school among adolescents in NSW, Australia.

PubMed

Booth, Michael L; Okely, Anthony D; Denney-Wilson, Elizabeth; Hardy, Louise L; Dobbins, Timothy; Wen, Li-Ming; Rissel, Christopher

2007-11-01

Active transport to and from school is frequently identified as an opportunity to increase energy expenditure among young people. The epidemiology of travel behaviours among Grade 6, 8 and 10 students in NSW is reported. A representative population survey of students in NSW, Australia was conducted during February to May 2004 (n = 2750) and the prevalence of travelling to and from school by walking, car and public transport was determined for Grade 6, 8 and 10 students. Among Grade 6 students, approximately 30% travelled by car, 30% walked and 20% used public transport to travel to school (the travel habits of 20% could not be accurately characterised). Among secondary school students, approximately 50% used public transport, 15-20% travelled by car and 15-20% walked. Among those who walked or used public transport, the median times spent walking were 10-15 min and 5 min per trip, respectively. While there is little scope to increase the prevalence of active transport among secondary school students, there is potential to do so among primary school students. Primary school students who replace travelling to and from school by car with walking will experience an increase in activity energy expenditure of up to 10% and those who change to public transport will experience an increase in activity energy expenditure of up to 3%.

Self-Reported and Observed Punitive Parenting Prospectively Predicts Increased Error-Related Brain Activity in Six-Year-Old Children.

PubMed

Meyer, Alexandria; Proudfit, Greg Hajcak; Bufferd, Sara J; Kujawa, Autumn J; Laptook, Rebecca S; Torpey, Dana C; Klein, Daniel N

2015-07-01

The error-related negativity (ERN) is a negative deflection in the event-related potential (ERP) occurring approximately 50 ms after error commission at fronto-central electrode sites and is thought to reflect the activation of a generic error monitoring system. Several studies have reported an increased ERN in clinically anxious children, and suggest that anxious children are more sensitive to error commission--although the mechanisms underlying this association are not clear. We have previously found that punishing errors results in a larger ERN, an effect that persists after punishment ends. It is possible that learning-related experiences that impact sensitivity to errors may lead to an increased ERN. In particular, punitive parenting might sensitize children to errors and increase their ERN. We tested this possibility in the current study by prospectively examining the relationship between parenting style during early childhood and children's ERN approximately 3 years later. Initially, 295 parents and children (approximately 3 years old) participated in a structured observational measure of parenting behavior, and parents completed a self-report measure of parenting style. At a follow-up assessment approximately 3 years later, the ERN was elicited during a Go/No-Go task, and diagnostic interviews were completed with parents to assess child psychopathology. Results suggested that both observational measures of hostile parenting and self-report measures of authoritarian parenting style uniquely predicted a larger ERN in children 3 years later. We previously reported that children in this sample with anxiety disorders were characterized by an increased ERN. A mediation analysis indicated that ERN magnitude mediated the relationship between harsh parenting and child anxiety disorder. Results suggest that parenting may shape children's error processing through environmental conditioning and thereby risk for anxiety, although future work is needed to confirm this hypothesis.

The effects of temperature on metabolic interaction between digestion and locomotion in juveniles of three cyprinid fish (Carassius auratus, Cyprinus carpio and Spinibarbus sinensis).

PubMed

Pang, Xu; Cao, Zhen-Dong; Fu, Shi-Jian

2011-07-01

To test whether the effects of temperature on the metabolic mode changed among different fish species, we investigated the specific dynamic action (SDA) and swimming performance of fasting and fed fish at 15 and 25°C in three juvenile Cyprinidae fish species: goldfish (Carassius auratus), common carp (Cyprinus carpio) and qingbo (Spinibarbus sinensis). Both taxon and temperature had significant effects on the resting oxygen consumption rate (M˙O(rest)), SDA and swimming performance (p<0.05). In addition, the effect of temperature differed significantly among the different species (interaction effect, p<0.05). Under the low temperature condition, digestion had no effect on either critical swimming speed (U(crit)) or the active MO(2) (MO(active)) for all fish species (additive metabolic mode). When the temperature was increased from 15 to 25°C, the metabolic scope (MS) for digestion increased approximately 182, 49 and 17%, and the MS for locomotion increased approximately 129, 58 and 138% in goldfish, common carp and qingbo, respectively. The total metabolic demands for both digestion and locomotion (i.e., the sum of digestive MS and locomotive MS) increased approximately 143, 56 and 112% in goldfish, common carp and qingbo, respectively. The total MS for both digestion and locomotion (the difference between MO(active) in fed fish and MO(rest) in fasting fish) increased approximately 106, 58 and 78% in goldfish, common carp and qingbo, respectively. Thus, the MS for locomotion in fed goldfish decreased due to the large increase in digestive function at the high temperature, and the U(crit) of fed goldfish decreased by 11% compared to that of fasting fish (p<0.05) (digestion-priory metabolic mode). The metabolic mode of qingbo changed to locomotion-priority mode, as illustrated by the large increase in locomotive MS in response to the increase in temperature. In the common carp, temperature had no effect on metabolic mode as illustrated by the parallel increases in cardio-respiratory capacity and metabolic capacity of digestive and locomotive organs. A discussion on the changes in metabolic mode in response to temperature and its possible relationship with the metabolic characteristics of a given fish species was also documented in this paper. Copyright © 2011 Elsevier Inc. All rights reserved.

Active-learning instruction on emergency contraception counseling.

PubMed

Young, Shardae; Griffin, Brooke; Vest, Kathleen

2013-06-12

To increase pharmacy students' knowledge of and confidence in counseling patients regarding emergency contraception and to identify any barriers to counseling patients about emergency contraception. Approximately 200 third-year pharmacy students participated in the Women's Health Therapeutics workshop at Midwestern University Chicago College of Pharmacy. Students observed a 5-minute skit of a counseling session on emergency contraception and then were asked to pair up with a classmate and practice counseling each other regarding the use of emergency contraception following a checklist of key points. One hundred eighty-nine students completed pre- and post-workshop survey instruments. Students' knowledge scores increased from 86% to 93% (p<0.001). Approximately 25% of the students stated they were confident in counseling patients on emergency contraception before completing the active-learning exercise compared to 58.5% after (p<0.001). The most common barrier to counseling that students identified on the pre- and post-workshop survey was lack of knowledge. Participation in an active-learning exercise significantly increased pharmacy students' knowledge of and confidence in counseling patients regarding emergency contraception and significantly reduced several barriers to counseling identified prior to participation.

An activation switch in the rhodopsin family of G protein-coupled receptors: the thyrotropin receptor.

PubMed

Urizar, Eneko; Claeysen, Sylvie; Deupí, Xavier; Govaerts, Cedric; Costagliola, Sabine; Vassart, Gilbert; Pardo, Leonardo

2005-04-29

We aimed at understanding molecular events involved in the activation of a member of the G protein-coupled receptor family, the thyrotropin receptor. We have focused on the transmembrane region and in particular on a network of polar interactions between highly conserved residues. Using molecular dynamics simulations and site-directed mutagenesis techniques we have identified residue Asn-7.49, of the NPxxY motif of TM 7, as a molecular switch in the mechanism of thyrotropin receptor (TSHr) activation. Asn-7.49 appears to adopt two different conformations in the inactive and active states. These two states are characterized by specific interactions between this Asn and polar residues in the transmembrane domain. The inactive gauche+ conformation is maintained by interactions with residues Thr-6.43 and Asp-6.44. Mutation of these residues into Ala increases the constitutive activity of the receptor by factors of approximately 14 and approximately 10 relative to wild type TSHr, respectively. Upon receptor activation Asn-7.49 adopts the trans conformation to interact with Asp-2.50 and a putatively charged residue that remains to be identified. In addition, the conserved Leu-2.46 of the (N/S)LxxxD motif also plays a significant role in restraining the receptor in the inactive state because the L2.46A mutation increases constitutive activity by a factor of approximately 13 relative to wild type TSHr. As residues Leu-2.46, Asp-2.50, and Asn-7.49 are strongly conserved, this molecular mechanism of TSHr activation can be extended to other members of the rhodopsin-like family of G protein-coupled receptors.

Development of neural networks for exact and approximate calculation: a FMRI study.

PubMed

Kucian, Karin; von Aster, Michael; Loenneker, Thomas; Dietrich, Thomas; Martin, Ernst

2008-01-01

Neuroimaging findings in adults suggest exact and approximate number processing relying on distinct neural circuits. In the present study we are investigating whether this cortical specialization is already established in 9- and 12-year-old children. Using fMRI, brain activation was measured in 10 third- and 10 sixth-grade school children and 20 adults during trials of symbolic approximate (AP) and exact (EX) calculation, as well as non-symbolic magnitude comparison (MC) of objects. Children activated similar networks like adults, denoting an availability and a similar spatial extent of specified networks as early as third grade. However, brain areas related to number processing become further specialized with schooling. Children showed weaker activation in the intraparietal sulcus during all three tasks, in the left inferior frontal gyrus during EX and in occipital areas during MC. In contrast, activation in the anterior cingulate gyrus, a region associated with attentional effort and working memory load, was enhanced in children. Moreover, children revealed reduced or absent deactivation of regions involved in the so-called default network during symbolic calculation, suggesting a rather general developmental effect. No difference in brain activation patterns between AP and EX was found. Behavioral results indicated major differences between children and adults in AP and EX, but not in MC. Reaction time and accuracy rate were not correlated to brain activation in regions showing developmental changes suggesting rather effects of development than performance differences between children and adults. In conclusion, increasing expertise with age may lead to more automated processing of mental arithmetic, which is reflected by improved performance and by increased brain activation in regions related to number processing and decreased activation in supporting areas.

Fatalities among oil and gas extraction workers--United States, 2003-2006.

PubMed

2008-04-25

Oil and gas extraction (i.e., removing oil and natural gas from the ground) is a growing industry in the United States, employing approximately 380,000 workers in 2006. In recent years, activity in this industry has increased substantially, from an average of 800 actively drilling rigs in the United States during the 1990s to approximately 1,300 during 2003-2006. In August 2005, the U.S. Department of Labor's Bureau of Labor Statistics (BLS) asked CDC to investigate a 15% increase in fatalities among oil and gas extraction workers (from 85 fatalities in 2003 to 98 in 2004). CDC analyzed data from the BLS Census of Fatal Occupational Injuries (CFOI) for the period 2003-2006. This report describes the results of that analysis, which indicated that increases in oil and gas extraction activity were correlated with an increase in the rate of fatal occupational injuries in this industry, with an annual fatality rate of 30.5 per 100,000 workers (404 fatalities) during 2003-2006, approximately seven times the rate for all workers (4.0 per 100,000 workers). Nearly half of all fatal injuries among these workers were attributed to highway motor-vehicle crashes and workers being struck by machinery or equipment. Employers should work with existing industry groups and federal, state, and local government agencies to promote seatbelt use. In addition, researchers and public health officials should collaborate with industry groups to establish engineering and process controls that remove workers from potentially dangerous machinery while drilling and servicing oil and gas wells.

Nonlinear coupling between cerebral blood flow, oxygen consumption, and ATP production in human visual cortex.

PubMed

Lin, Ai-Ling; Fox, Peter T; Hardies, Jean; Duong, Timothy Q; Gao, Jia-Hong

2010-05-04

The purpose of this study was to investigate activation-induced hypermetabolism and hyperemia by using a multifrequency (4, 8, and 16 Hz) reversing-checkerboard visual stimulation paradigm. Specifically, we sought to (i) quantify the relative contributions of the oxidative and nonoxidative metabolic pathways in meeting the increased energy demands [i.e., ATP production (J(ATP))] of task-induced neuronal activation and (ii) determine whether task-induced cerebral blood flow (CBF) augmentation was driven by oxidative or nonoxidative metabolic pathways. Focal increases in CBF, cerebral metabolic rate of oxygen (CMRO(2); i.e., index of aerobic metabolism), and lactate production (J(Lac); i.e., index of anaerobic metabolism) were measured by using physiologically quantitative MRI and spectroscopy methods. Task-induced increases in J(ATP) were small (12.2-16.7%) at all stimulation frequencies and were generated by aerobic metabolism (approximately 98%), with %DeltaJ(ATP) being linearly correlated with the percentage change in CMRO(2) (r = 1.00, P < 0.001). In contrast, task-induced increases in CBF were large (51.7-65.1%) and negatively correlated with the percentage change in CMRO(2) (r = -0.64, P = 0.024), but positively correlated with %DeltaJ(Lac) (r = 0.91, P < 0.001). These results indicate that (i) the energy demand of task-induced brain activation is small (approximately 15%) relative to the hyperemic response (approximately 60%), (ii) this energy demand is met through oxidative metabolism, and (iii) the CBF response is mediated by factors other than oxygen demand.

Nitrate concentration effects on NO3-N uptake and reduction, growth, and fruit yield in strawberry

NASA Technical Reports Server (NTRS)

Darnell, R. L.; Stutte, G. W.; Sager, J. C. (Principal Investigator)

2001-01-01

Strawberries (Fragaria xananassa Duch. 'Osogrande') were grown hydroponically with three NO3-N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO3-N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO3-N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO3-N concentration in the hydroponics system increased. Tissue NO3- concentration also increased as external NO3-N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO3-N concentration on NR activities in leaves or roots during either stage of development. Leaf NR activity averaged approximately 360 nmol NO2 formed/g fresh weight (FW)/h over both developmental stages, while NR activity in roots was much lower, averaging approximately 115 nmol NO2 formed/g FW/h. Vegetative organ FW, dry weight (DW), and total fruit yield were unaffected by NO3-N concentration. These data suggest that the inability of strawberry to increase growth and fruit yield in response to increasing NO3-N concentrations is not due to limitations in NO3-N uptake rates, but rather to limitations in NO3- reduction and/or assimilation in both roots and leaves.

Conservation practices to mitigate and adapt to the effects of climate change

USDA-ARS?s Scientific Manuscript database

Greenhouse gases (GHGs) emitted into the atmosphere by human activities have increased radiative forcing and caused an increase in the global mean temperature of approximately 0.74°C over the past century. In terms of soil conservation, expected consequences of future climate change include changes ...

Reinforcement Learning with Orthonormal Basis Adaptation Based on Activity-Oriented Index Allocation

NASA Astrophysics Data System (ADS)

Satoh, Hideki

An orthonormal basis adaptation method for function approximation was developed and applied to reinforcement learning with multi-dimensional continuous state space. First, a basis used for linear function approximation of a control function is set to an orthonormal basis. Next, basis elements with small activities are replaced with other candidate elements as learning progresses. As this replacement is repeated, the number of basis elements with large activities increases. Example chaos control problems for multiple logistic maps were solved, demonstrating that the method for adapting an orthonormal basis can modify a basis while holding the orthonormality in accordance with changes in the environment to improve the performance of reinforcement learning and to eliminate the adverse effects of redundant noisy states.

Hepatitis C virus NS3 helicase forms oligomeric structures that exhibit optimal DNA unwinding activity in vitro.

PubMed

Sikora, Bartek; Chen, Yingfeng; Lichti, Cheryl F; Harrison, Melody K; Jennings, Thomas A; Tang, Yong; Tackett, Alan J; Jordan, John B; Sakon, Joshua; Cameron, Craig E; Raney, Kevin D

2008-04-25

HCV NS3 helicase exhibits activity toward DNA and RNA substrates. The DNA helicase activity of NS3 has been proposed to be optimal when multiple NS3 molecules are bound to the same substrate molecule. NS3 catalyzes little or no measurable DNA unwinding under single cycle conditions in which the concentration of substrate exceeds the concentration of enzyme by 5-fold. However, when NS3 (100 nm) is equimolar with the substrate, a small burst amplitude of approximately 8 nm is observed. The burst amplitude increases as the enzyme concentration increases, consistent with the idea that multiple molecules are needed for optimal unwinding. Protein-protein interactions may facilitate optimal activity, so the oligomeric properties of the enzyme were investigated. Chemical cross-linking indicates that full-length NS3 forms higher order oligomers much more readily than the NS3 helicase domain. Dynamic light scattering indicates that full-length NS3 exists as an oligomer, whereas NS3 helicase domain exists in a monomeric form in solution. Size exclusion chromatography also indicates that full-length NS3 behaves as an oligomer in solution, whereas the NS3 helicase domain behaves as a monomer. When NS3 was passed through a small pore filter capable of removing protein aggregates, greater than 95% of the protein and the DNA unwinding activity was removed from solution. In contrast, only approximately 10% of NS3 helicase domain and approximately 20% of the associated DNA unwinding activity was removed from solution after passage through the small pore filter. The results indicate that the optimally active form of full-length NS3 is part of an oligomeric species in vitro.

Practical approximation method for firing-rate models of coupled neural networks with correlated inputs

NASA Astrophysics Data System (ADS)

Barreiro, Andrea K.; Ly, Cheng

2017-08-01

Rapid experimental advances now enable simultaneous electrophysiological recording of neural activity at single-cell resolution across large regions of the nervous system. Models of this neural network activity will necessarily increase in size and complexity, thus increasing the computational cost of simulating them and the challenge of analyzing them. Here we present a method to approximate the activity and firing statistics of a general firing rate network model (of the Wilson-Cowan type) subject to noisy correlated background inputs. The method requires solving a system of transcendental equations and is fast compared to Monte Carlo simulations of coupled stochastic differential equations. We implement the method with several examples of coupled neural networks and show that the results are quantitatively accurate even with moderate coupling strengths and an appreciable amount of heterogeneity in many parameters. This work should be useful for investigating how various neural attributes qualitatively affect the spiking statistics of coupled neural networks.

Antioxidant Properties of Crude Extract, Partition Extract, and Fermented Medium of Dendrobium sabin Flower

PubMed Central

Abu, Farahziela; Mohd Akhir, Sobri

2017-01-01

Antioxidant properties of crude extract, partition extract, and fermented medium from Dendrobium sabin (DS) flower were investigated. The oven-dried DS flower was extracted using 100% methanol (w/v), 100% ethanol (w/v), and 100% water (w/v). The 100% methanolic crude extract showed the highest total phenolic content (40.33 ± mg GAE/g extract) and the best antioxidant properties as shown by DPPH, ABTS, and FRAP assays. A correlation relationship between antioxidant activity and total phenolic content showed that phenolic compounds were the dominant antioxidant components in this flower extract. The microbial fermentation on DS flower medium showed a potential in increasing the phenolic content and DPPH scavenging activity. The TPC of final fermented medium showed approximately 18% increment, while the DPPH of fermented medium increased significantly to approximately 80% at the end of the fermentation. Dendrobium sabin (DS) flower showed very good potential properties of antioxidant in crude extract and partition extract as well as better antioxidant activity in the flower fermented medium. PMID:28761496

Trends in Sports- and Recreation-Related Traumatic Brain Injuries Treated in US Emergency Departments: The National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP) 2001-2012.

PubMed

Coronado, Victor G; Haileyesus, Tadesse; Cheng, Tabitha A; Bell, Jeneita M; Haarbauer-Krupa, Juliet; Lionbarger, Michael R; Flores-Herrera, Javier; McGuire, Lisa C; Gilchrist, Julie

2015-01-01

Sports- and recreation-related traumatic brain injuries (SRR-TBIs) are a growing public health problem affecting persons of all ages in the United States. To describe the trends of SRR-TBIs treated in US emergency departments (EDs) from 2001 to 2012 and to identify which sports and recreational activities and demographic groups are at higher risk for these injuries. Data on initial ED visits for an SRR-TBI from the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP) for 2001-2012 were analyzed. NEISS-AIP data are drawn from a nationally representative sample of hospital-based EDs. Cases of TBI were identified from approximately 500,000 annual initial visits for all causes and types of injuries treated in EDs captured by NEISS-AIP. Numbers and rates by age group, sex, and year were estimated. Aggregated numbers and percentages by discharge disposition were produced. Approximately 3.42 million ED visits for an SRR-TBI occurred during 2001-2012. During this period, the rates of SRR-TBIs treated in US EDs significantly increased in both males and females regardless of age (all Ps < .001). For males, significant increases ranged from a low of 45.8% (ages 5-9) to a high of 139.8% (ages 10-14), and for females, from 25.1% (ages 0-4) to 211.5% (ages 15-19) (all Ps < .001). Every year males had about twice the rates of SRR-TBIs than females. Approximately 70% of all SRR-TBIs were reported among persons aged 0 to 19 years. The largest number of SRR-TBIs among males occurred during bicycling, football, and basketball. Among females, the largest number of SRR-TBIs occurred during bicycling, playground activities, and horseback riding. Approximately 89% of males and 91% of females with an SRR-TBI were treated and released from EDs. The rates of ED-treated SRR-TBIs increased during 2001-2012, affecting mainly persons aged 0 to 19 years and males in all age groups. Increases began to appear in 2004 for females and 2006 for males. Activities associated with the largest number of TBIs varied by sex and age. Reasons for the reported increases in ED visits are unknown but may be associated with increased awareness of TBI through increased media exposure and from campaigns, such as the Centers for Disease Control and Prevention's Heads Up. Prevention efforts should be targeted by sports and recreational activity, age, and sex.

Fabrication of silicon-on-diamond substrate with an ultrathin SiO2 bonding layer

NASA Astrophysics Data System (ADS)

Nagata, Masahiro; Shirahama, Ryouya; Duangchan, Sethavut; Baba, Akiyoshi

2018-06-01

We proposed and demonstrated a sputter etching method to prepare both a flat surface (root-mean-square surface roughness of approximately 0.2–0.3 nm) and an ultrathin SiO2 bonding layer at an accuracy of approximately 5 nm in thickness to fabricate a silicon-on-diamond substrate (SOD). We also investigated a plasma activation method on a SiO2 surface using various gases. We found that O2 plasma activation is more suitable for the bonding between SiO2 and Si than N2 or Ar plasma activation. We speculate that the concentration of hydroxyl groups on the SiO2 surface was increased by O2 plasma activation. We fabricated the SOD substrate with an ultrathin (15 nm in thickness) SiO2 bonding layer using the sputter etching and O2 plasma activation methods.

Rigidity sensing explained by active matter theory.

PubMed

Marcq, Philippe; Yoshinaga, Natsuhiko; Prost, Jacques

2011-09-21

The magnitude of traction forces exerted by living animal cells on their environment is a monotonically increasing and approximately sigmoidal function of the stiffness of the external medium. We rationalize this observation using active matter theory, and propose that adaptation to substrate rigidity results from an interplay between passive elasticity and active contractility. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The social costs of tobacco advertising and promotions.

PubMed

Emery, S; Choi, W S; Pierce, J P

1999-01-01

Recent longitudinal evidence suggests that approximately 34% of all new tobacco experimentation occurs because of tobacco advertising and promotions. Based on this figure, in this paper we estimate the long-term impact on mortality and morbidity, as well as the economic and medical costs associated with smoking that is attributable to cigarette advertising and promotions in the United States. This study used several data sources, including the Teenage Attitudes and Practices Survey (TAPS), the 1993 and 1996 Adolescent California Tobacco Surveys (CTS), and the Food and Drug Administration's estimates of annual illness-related benefits of alternative effectiveness rates of banning tobacco advertising. Our resulting estimates are that in each year between 1988 and 1998, tobacco advertising and promotional activities generated approximately 193000 additional adult smokers who began smoking as adolescents because of advertisements and promotions. That decade of tobacco advertising and promotions will also result in approximately 46400 smoking-attributable deaths per year and 698400 years of potential life lost, which translates into costs of approximately $21.7 billion to $33.3 billion in total medical, productivity, and mortality-related costs. Even accounting for quitting behavior, each year of advertising-attributable smoking increases the number of smokers in the population. We conclude that annual costs can be expected to continue to increase if tobacco advertising and promotional activities are not effectively eliminated. If all tobacco industry advertising and promotional activities were banned for the next 25 years, nearly 60000 smoking-attributable deaths per year could be avoided, saving nearly 900000 life-years, $2.6 billion in excess medical expenses, and between $28 billion and $43 billion in mortality costs.

Dyscalculia and the Calculating Brain.

PubMed

Rapin, Isabelle

2016-08-01

Dyscalculia, like dyslexia, affects some 5% of school-age children but has received much less investigative attention. In two thirds of affected children, dyscalculia is associated with another developmental disorder like dyslexia, attention-deficit disorder, anxiety disorder, visual and spatial disorder, or cultural deprivation. Infants, primates, some birds, and other animals are born with the innate ability, called subitizing, to tell at a glance whether small sets of scattered dots or other items differ by one or more item. This nonverbal approximate number system extends mostly to single digit sets as visual discrimination drops logarithmically to "many" with increasing numerosity (size effect) and crowding (distance effect). Preschoolers need several years and specific teaching to learn verbal names and visual symbols for numbers and school agers to understand their cardinality and ordinality and the invariance of their sequence (arithmetic number line) that enables calculation. This arithmetic linear line differs drastically from the nonlinear approximate number system mental number line that parallels the individual number-tuned neurons in the intraparietal sulcus in monkeys and overlying scalp distribution of discrete functional magnetic resonance imaging activations by number tasks in man. Calculation is a complex skill that activates both visual and spatial and visual and verbal networks. It is less strongly left lateralized than language, with approximate number system activation somewhat more right sided and exact number and arithmetic activation more left sided. Maturation and increasing number skill decrease associated widespread non-numerical brain activations that persist in some individuals with dyscalculia, which has no single, universal neurological cause or underlying mechanism in all affected individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

Streamlining of medical relief to areas affected by the Great East Japan earthquake with the "area-based/line-linking support system".

PubMed

Yamanouchi, Satoshi; Ishii, Tadashi; Morino, Kazuma; Furukawa, Hajime; Hozawa, Atsushi; Ochi, Sae; Kushimoto, Shigeki

2014-12-01

When disasters that affect a wide area occur, external medical relief teams play a critical role in the affected areas by helping to alleviate the burden caused by surging numbers of individuals requiring health care. Despite this, no system has been established for managing deployed medical relief teams during the subacute phase following a disaster. After the Great East Japan Earthquake and tsunami, the Ishinomaki Medical Zone was the most severely-affected area. Approximately 6,000 people died or were missing, and the immediate evacuation of approximately 120,000 people to roughly 320 shelters was required. As many as 59 medical teams came to participate in relief activities. Daily coordination of activities and deployment locations became a significant burden to headquarters. The Area-based/Line-linking Support System (Area-Line System) was thus devised to resolve these issues for medical relief and coordinating activities. A retrospective analysis was performed to examine the effectiveness of the medical relief provided to evacuees using the Area-Line System with regards to the activities of the medical relief teams and the coordinating headquarters. The following were compared before and after establishment of the Area-Line System: (1) time required at the coordinating headquarters to collect and tabulate medical records from shelters visited; (2) time required at headquarters to determine deployment locations and activities of all medical relief teams; and (3) inter-area variation in number of patients per team. The time required to collect and tabulate medical records was reduced from approximately 300 to 70 minutes/day. The number of teams at headquarters required to sort through data was reduced from 60 to 14. The time required to determine deployment locations and activities of the medical relief teams was reduced from approximately 150 hours/month to approximately 40 hours/month. Immediately prior to establishment of the Area-Line System, the variation of the number of patients per team was highest. Variation among regions did not increase after establishment of the system. This descriptive analysis indicated that implementation of the Area-Line System, a systematic approach for long-term disaster medical relief across a wide area, can increase the efficiency of relief provision to disaster-stricken areas.

Distress of Routine Activities and Perceived Safety Associated with Post-Traumatic Stress, Depression, and Alcohol Use: 2002 Washington, DC, Sniper Attacks.

PubMed

Fullerton, Carol S; Herberman Mash, Holly B; Benevides, K Nikki; Morganstein, Joshua C; Ursano, Robert J

2015-10-01

For over 3 weeks in October 2002, a series of sniper attacks in the Washington, DC, area left 10 people dead and 3 wounded. This study examined the relationship of distress associated with routine activities and perceived safety to psychological and behavioral responses. Participants were 1238 residents of the Washington, DC, metropolitan area (aged 18 to 90 years, mean=41.7 years) who completed an Internet survey including the Impact of Event Scale-Revised, Patient Health Questionnaire-9, and items pertaining to distress related to routine activities, perceived safety, and alcohol use. Data were collected at one time point approximately 3 weeks after the first sniper shooting and before apprehension of the suspects. Relationships of distress and perceived safety to post-traumatic stress, depressive symptoms, and increased alcohol use were examined by using linear and logistic regression analyses. Approximately 8% of the participants met the symptom criteria for probable post-traumatic stress disorder, 22% reported mild to severe depression, and 4% reported increased alcohol use during the attacks. Distress related to routine activities and perceived safety were associated with increased post-traumatic stress and depressive symptoms and alcohol use. Distress and perceived safety are associated with specific routine activities and both contribute to psychological and behavioral responses during a terrorist attack. These findings have implications for targeted information dissemination and risk communication by community leaders.

Mechanism of allosteric inhibition of N-acetyl-L-glutamate synthase by L-arginine.

PubMed

Min, Li; Jin, Zhongmin; Caldovic, Ljubica; Morizono, Hiroki; Allewell, Norma M; Tuchman, Mendel; Shi, Dashuang

2009-02-20

N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in l-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by l-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with l-arginine bound and in the active R-state complexed with CoA and l-glutamate. Under all of the conditions examined, the enzyme consists of two stacked trimers. Each monomer has two domains: an amino acid kinase (AAK) domain with an AAK-like fold but lacking kinase activity and an N-acetyltransferase (NAT) domain homologous to other GCN5-related transferases. Binding of l-arginine to the AAK domain induces a global conformational change that increases the diameter of the hexamer by approximately 10 A and decreases its height by approximately 20A(.) AAK dimers move 5A outward along their 2-fold axes, and their tilt relative to the plane of the hexamer decreases by approximately 4 degrees . The NAT domains rotate approximately 109 degrees relative to AAK domains enabling new interdomain interactions. Interactions between AAK and NAT domains on different subunits also change. Local motions of several loops at the l-arginine-binding site enable the protein to close around the bound ligand, whereas several loops at the NAT active site become disordered, markedly reducing enzymatic specific activity.

Narciclasine as well as other Amaryllidaceae isocarbostyrils are promising GTP-ase targeting agents against brain cancers.

PubMed

Van Goietsenoven, Gwendoline; Mathieu, Véronique; Lefranc, Florence; Kornienko, Alexander; Evidente, Antonio; Kiss, Robert

2013-03-01

The anticancer activity of Amaryllidaceae isocarbostyrils is well documented. At pharmacological concentrations, that is, approximately 1 μM in vitro and approximately 10 mg/kg in vivo, narciclasine displays marked proapoptotic and cytotoxic activity, as does pancratistatin, and significant in vivo anticancer effects in various experimental models, but it is also associated with severe toxic side effects. At physiological doses, that is, approximately 50 nM in vitro and approximately 1 mg/kg in vivo, narciclasine is not cytotoxic but cytostatic and displays marked anticancer activity in vivo in experimental models of brain cancer (including gliomas and brain metastases), but it is not associated with toxic side effects. The cytostatic activity of narciclasine involves the impairment of actin cytoskeleton organization by targeting GTPases, including RhoA and the elongation factor eEF1A. We have demonstrated that chronic treatments of narciclasine (1 mg/kg) significantly increased the survival of immunodeficient mice orthotopically xenografted with highly invasive human glioblastomas and apoptosis-resistant brain metastases, including melanoma- and non-small-cell-lung cancer- (NSCLC) related brain metastases. Thus, narciclasine is a potentially promising agent for the treatment of primary brain cancers and various brain metastases. To date, efforts to develop synthetic analogs with anticancer properties superior to those of narciclasine have failed; thus, research efforts are now focused on narciclasine prodrugs. © 2012 Wiley Periodicals, Inc.

Contribution of intestinal- and cereal-derived phytase activity on phytate degradation in young broilers.

PubMed

Morgan, N K; Walk, C L; Bedford, M R; Burton, E J

2015-07-01

There is little consensus as to the capability of poultry to utilize dietary phytate without supplemental phytase. Therefore, an experiment was conducted to examine the extent to which endogenous phytase of intestinal and cereal origin contributes to phytate degradation in birds aged 0 to 14 d posthatch. Ross 308 broilers (n = 720) were fed one of 4 experimental diets with differing dietary ingredient combinations and approximate total phytate levels of 10 g/kg, dietary phytase activity analyzed at 460 U/kg, dietary calcium (Ca) levels of 11 g/kg, and nonphytate-phosphorus (P) levels of 4 g/kg. Broiler performance, gizzard, duodenum, jejunum and ileum pH, Ca and P digestibility and solubility, amount of dietary phytate hydrolyzed in the gizzard, jejunum, and ileal digesta phytase activity were analyzed at d 4, 6, 8, 10, 12, and 14 posthatch. Intestinal endogenous phytase activity increased significantly (P < 0.001) between d 4 and 6, resulting in increased phytate hydrolysis in the gizzard (P = 0.003), jejunum (P < 0.001), and ileum (P < 0.001). Phytase activity and phytate hydrolysis continued to increase with age, with a greater phytase activity and associated increase in phytate hydrolysis and mineral utilization between d 10 and 12. Gizzard and jejunum Ca and P solubility and ileal Ca and P digestibility increased significantly (P < 0.001), and gastrointestinal pH decreased significantly (P < 0.001) between d 4 and 6. By d 14, phytase activity recovered in the ileum was approximately 45 U/kg. There were strong correlations between phytase activity measured in the ileum and phytate hydrolyzed in the gizzard (r = 0.905, P < 0.001), jejunum (r = 0.901, P = 0.023), and ileum (r = 0.938, P = 0.042). This study shows intestinal- and dietary-derived endogenous phytase activity is responsible for phytate-P hydrolysis in broilers. © 2015 Poultry Science Association Inc.

Teen Sexual Activity, Pregnancy and Childbearing among Latinos in the United States. Fact Sheet.

ERIC Educational Resources Information Center

National Campaign To Prevent Teen Pregnancy, Washington, DC.

The Latino population is the fastest-growing major racial/ethnic group in the United States. By 2020, approximately 16 percent of the population will be Latino. This increase will be even more pronounced among teens. This fact sheet summarizes data from the National Vital Statistics Reports on reported sexual activity, pregnancy rates, and…

"Drunkorexia": Understanding Eating and Physical Activity Behaviors of Weight Conscious Drinkers in a Sample of College Students

ERIC Educational Resources Information Center

Wilkerson, Amanda H.; Hackman, Christine L.; Rush, Sarah E.; Usdan, Stuart L.; Smith, Corinne S.

2017-01-01

Objective: Behaviors of weight conscious drinkers (BWCD) include disordered eating, excessive physical activity (PA), and heavy episodic drinking. Considering that approximately 25% of the college students report BWCD, it is important to investigate what characteristics increase the likelihood of college students engaged in BWCD for both moderate…

Exercise-induced changes in local cerebral glucose utilization in the rat.

PubMed

Vissing, J; Andersen, M; Diemer, N H

1996-07-01

In exercise, little is known about local cerebral glucose utilization (LCGU), which is an index of functional neurogenic activity. We measured LCGU in resting and running (approximately 85% of maximum O2 uptake) rats (n = 7 in both groups) previously equipped with a tail artery catheter. LCGU was measured quantitatively from 2-deoxy-D-[1-14C]glucose autoradiographs. During exercise, total cerebral glucose utilization (TCGU) increased by 38% (p < 0.005). LCGU increased (p < 0.05) in areas involved in motor function (motor cortex 39%, cerebellum approximately 110%, basal ganglia approximately 30%, substantia nigra approximately 37%, and in the following nuclei: subthalamic 47%, posterior hypothalamic 74%, red 61%, ambiguous 43%, pontine 61%), areas involved in sensory function (somatosensory 27%, auditory 32%, and visual cortex 42%, thalamus approximately 75%, and in the following nuclei: Darkschewitsch 22%, cochlear 51%, vestibular 30%, superior olive 23%, cuneate 115%), areas involved in autonomic function (dorsal raphe nucleus 30%, and areas in the hypothalamus approximately 35%, amygdala approximately 35%, and hippocampus 29%), and in white matter of the corpus callosum (36%) and cerebellum (52%). LCGU did not change with exercise in prefrontal and frontal cortex, cingulum, inferior olive, nucleus of solitary tract and median raphe, lateral septal and interpenduncular nuclei, or in areas of the hippocampus, amygdala, and hypothalamus. Glucose utilization did not decrease during exercise in any of the studied cerebral regions. In summary, heavy dynamic exercise increases TCGU and evokes marked differential changes in LCGU. The findings provide clues to the cerebral areas that participate in the large motor, sensory, and autonomic adaptation occurring in exercise.

Active-Learning Instruction on Emergency Contraception Counseling

PubMed Central

Young, Shardae; Vest, Kathleen

2013-01-01

Objective. To increase pharmacy students’ knowledge of and confidence in counseling patients regarding emergency contraception and to identify any barriers to counseling patients about emergency contraception. Design. Approximately 200 third-year pharmacy students participated in the Women’s Health Therapeutics workshop at Midwestern University Chicago College of Pharmacy. Students observed a 5-minute skit of a counseling session on emergency contraception and then were asked to pair up with a classmate and practice counseling each other regarding the use of emergency contraception following a checklist of key points. Assessment. One hundred eighty-nine students completed pre- and post-workshop survey instruments. Students’ knowledge scores increased from 86% to 93% (p<0.001). Approximately 25% of the students stated they were confident in counseling patients on emergency contraception before completing the active-learning exercise compared to 58.5% after (p<0.001). The most common barrier to counseling that students identified on the pre- and post-workshop survey was lack of knowledge. Conclusion. Participation in an active-learning exercise significantly increased pharmacy students’ knowledge of and confidence in counseling patients regarding emergency contraception and significantly reduced several barriers to counseling identified prior to participation. PMID:23788815

Diagnosis and management of post-traumatic stress disorder.

PubMed

Grinage, Bradley D

2003-12-15

Although post-traumatic stress disorder (PTSD) is a debilitating anxiety disorder that may cause significant distress and increased use of health resources, the condition often goes undiagnosed. The lifetime prevalence of PTSD in the United States is 8 to 9 percent, and approximately 25 to 30 percent of victims of significant trauma develop PTSD. The emotional and physical symptoms of PTSD occur in three clusters: re-experiencing the trauma, marked avoidance of usual activities, and increased symptoms of arousal. Before a diagnosis of PTSD can be made, the patient's symptoms must significantly disrupt normal activities and last for more than one month. Approximately 80 percent of patients with PTSD have at least one comorbid psychiatric disorder. The most common comorbid disorders include depression, alcohol and drug abuse, and other anxiety disorders. Treatment relies on a multidimensional approach, including supportive patient education, cognitive behavior therapy, and psychopharmacology. Selective serotonin reuptake inhibitors are the mainstay of pharmacologic treatment.

Pushing the glass transition towards random close packing using self-propelled hard spheres

NASA Astrophysics Data System (ADS)

Ni, Ran; Stuart, Martien A. Cohen; Dijkstra, Marjolein

2013-10-01

Although the concept of random close packing with an almost universal packing fraction of approximately 0.64 for hard spheres was introduced more than half a century ago, there are still ongoing debates. The main difficulty in searching the densest packing is that states with packing fractions beyond the glass transition at approximately 0.58 are inherently non-equilibrium systems, where the dynamics slows down with a structural relaxation time diverging with density; hence, the random close packing is inaccessible. Here we perform simulations of self-propelled hard spheres, and we find that with increasing activity the relaxation dynamics can be sped up by orders of magnitude. The glass transition shifts to higher packing fractions upon increasing the activity, allowing the study of sphere packings with fluid-like dynamics at packing fractions close to RCP. Our study opens new possibilities of investigating dense packings and the glass transition in systems of hard particles.

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.

Glycogen supercompensation masks the effect of a traininginduced increase in GLUT-4 on muscle glucose transport.

PubMed

Host, H H; Hansen, P A; Nolte, L A; Chen, M M; Holloszy, J O

1998-07-01

Endurance exercise training induces a rapid increase in the GLUT-4 isoform of the glucose transporter in muscle. In fasted rats, insulin-stimulated muscle glucose transport is increased in proportion to the increase in GLUT-4. There is evidence that high muscle glycogen may decrease insulin-stimulated glucose transport. This study was undertaken to determine whether glycogen supercompensation interferes with the increase in glucose transport associated with an exercise-induced increase in GLUT-4. Rats were trained by means of swimming for 6 h/day for 2 days. Rats fasted overnight after the last exercise bout had an approximately twofold increase in epitrochlearis muscle GLUT-4 and an associated approximately twofold increase in maximally insulin-stimulated glucose transport activity. Epitrochlearis muscles of rats fed rodent chow after exercise were glycogen supercompensated (86.4 +/- 4.8 micromol/g wet wt) and showed no significant increase in maximally insulin-stimulated glucose transport above the sedentary control value despite an approximately twofold increase in GLUT-4. Fasting resulted in higher basal muscle glucose transport rates in both sedentary and trained rats but did not significantly increase maximally insulin-stimulated transport in the sedentary group. We conclude that carbohydrate feeding that results in muscle glycogen supercompensation prevents the increase in maximally insulin-stimulated glucose transport associated with an exercise training-induced increase in muscle GLUT-4.

Gaseous oxygen uptake in porous media at different moisture contents and airflow velocities.

PubMed

Sharma, Prabhakar; Poulsen, Tjalfe G; Kalluri, Prasad N V

2009-06-01

The presence and distribution of water in the pore space is a critical factor for flow and transport of gases through unsaturated porous media. The water content also affects the biological activity necessary for treatment of polluted gas streams in biofilters. In this research, microbial activity and quantity of inactive volume in a porous medium as a function of moisture content and gas flow rate were investigated. Yard waste compost was used as a test medium, and oxygen uptake rate measurements were used to quantify microbial activity and effective active compost volume using batch and column flow-through systems. Compost water contents were varied from air-dry to field capacity and gas flows ranged from 0.2 to 2 L x min(-1). The results showed that overall microbial activity and the relative fraction of active compost medium volume increased with airflow velocity for all levels of water content up to a certain flow rate above which the oxygen uptake rate assumed a constant value independent of gas flow. The actual value of the maximum oxygen uptake rate was controlled by the water content. The oxygen uptake rate also increased with increasing water content and reached a maximum between 42 and 48% volumetric water content, above which it decreased, again likely because of formation of inactive zones in the compost medium. Overall, maximum possible oxygen uptake rate as a function of gas flow rate across all water contents and gas flows could be approximated by a linear expression. The relative fraction of active volume also increased with gas flow rate and reached approximately 80% for the highest gas flows used.

How many steps/day are enough? For older adults and special populations

PubMed Central

2011-01-01

Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and including these background activities, the evidence suggests that 30 minutes of daily MVPA accumulated in addition to habitual daily activities in healthy older adults is equivalent to taking approximately 7,000-10,000 steps/day. Those living with disability and/or chronic illness (that limits mobility and or/physical endurance) display lower levels of background daily activity, and this will affect whole-day estimates of recommended physical activity. PMID:21798044

Recovery of rat alveolar macrophages by bronchoalveolar lavage under normal and activated conditions.

PubMed Central

Rehn, B; Bruch, J; Zou, T; Hobusch, G

1992-01-01

When rat (female Wistar) lungs were lavaged (bronchoalveolar lavage, BAL) six times with physiological saline, approximately the same number of alveolar macrophages (AM) were found in the first and second BAL, whereas in the third fourth, fifth, and sixth BAL, the number of AM decreased exponentially. Morphometric counting of the number of AM in histological sections of lung tissue showed that only 14% of the AM population had been recovered by BAL. Although additives to the BAL fluid such as lidocaine and/or fetal calf serum increased the AM count in the first washing considerably, the total number of AM washed out remained unaltered. Addition of the phagocytosis stimulant zymosan increased the AM count in BAL by a factor of more than 2. On stimulation of the lungs with an inert dust (silicon carbide), the AM count in the BAL and the lung was only slightly increased 8 weeks after intratracheal instillation. In contrast, after exposure to fibrogenic and cytotoxic quartz, the AM count in BAL and lung was significantly increased, and the recovery of AM had also increased by a factor of approximately 2. The experiments show that it is the micromilieu of the alveoli and the condition of the AM (certain physiological activation states, such as phagocytic activity) that essentially determine the degree of recovery. PMID:1396444

Assimilation of elements and digestion in grass shrimp pre-exposed to dietary mercury.

PubMed

Seebaugh, David R; Wallace, William G; L'amoreaux, William J; Stewart, Gillian M

2012-08-01

Grass shrimp Palaemonetes pugio were fed mercury (Hg)-contaminated oligochaetes for 15 days and analyzed for Hg, cadmium (Cd), and carbon assimilation efficiencies (AE) as well as toxicological end points related to digestion. Disproportionate increases in stable Hg concentrations in shrimp did not appear to be related to partitioning to trophically available Hg in worms. Hg AE by pre-exposed shrimp reached a plateau (approximately 53 %), whereas Cd AE varied (approximately 40-60 %) in a manner that was not dose-dependent. Carbon AE did not differ among treatments (approximately 69 %). Gut residence time was not impacted significantly by Hg pre-exposure (grand median approximately 465 min), however, there was a trend between curves showing percentages of individuals with markers in feces over time versus treatment. Feces-elimination rate did not vary with dietary pre-exposure. Extracellular protease activity varied approximately 1.9-fold but did not exhibit dose-dependency. pH increased over the range of Hg pre-exposures within the anterior (pH approximately 5.33-6.51) and posterior (pH approximately 5.29-6.25) regions of the cardiac proventriculus and Hg assimilation exhibited a negative relationship to hydrogen ion concentrations. The results of this study indicate that previous Hg ingestion can elicit post-assimilatory impacts on grass shrimp digestive physiology, which may, in turn, influence Hg assimilation during subsequent digestive cycles.

Endogenous circadian rhythm in human motor activity uncoupled from circadian influences on cardiac dynamics.

PubMed

Ivanov, Plamen Ch; Hu, Kun; Hilton, Michael F; Shea, Steven A; Stanley, H Eugene

2007-12-26

The endogenous circadian pacemaker influences key physiologic functions, such as body temperature and heart rate, and is normally synchronized with the sleep/wake cycle. Epidemiological studies demonstrate a 24-h pattern in adverse cardiovascular events with a peak at approximately 10 a.m. It is unknown whether this pattern in cardiac risk is caused by a day/night pattern of behaviors, including activity level and/or influences from the internal circadian pacemaker. We recently found that a scaling index of cardiac vulnerability has an endogenous circadian peak at the circadian phase corresponding to approximately 10 a.m., which conceivably could contribute to the morning peak in cardiac risk. Here, we test whether this endogenous circadian influence on cardiac dynamics is caused by circadian-mediated changes in motor activity or whether activity and heart rate dynamics are decoupled across the circadian cycle. We analyze high-frequency recordings of motion from young healthy subjects during two complementary protocols that decouple the sleep/wake cycle from the circadian cycle while controlling scheduled behaviors. We find that static activity properties (mean and standard deviation) exhibit significant circadian rhythms with a peak at the circadian phase corresponding to 5-9 p.m. ( approximately 9 h later than the peak in the scale-invariant index of heartbeat fluctuations). In contrast, dynamic characteristics of the temporal scale-invariant organization of activity fluctuations (long-range correlations) do not exhibit a circadian rhythm. These findings suggest that endogenous circadian-mediated activity variations are not responsible for the endogenous circadian rhythm in the scale-invariant structure of heartbeat fluctuations and likely do not contribute to the increase in cardiac risk at approximately 10 a.m.

210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

NASA Astrophysics Data System (ADS)

Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.

Self-reported and observed punitive parenting prospectively predicts increased error-related brain activity in six-year-old children

PubMed Central

Meyer, Alexandria; Proudfit, Greg Hajcak; Bufferd, Sara J.; Kujawa, Autumn J.; Laptook, Rebecca S.; Torpey, Dana C.; Klein, Daniel N.

2017-01-01

The error-related negativity (ERN) is a negative deflection in the event-related potential (ERP) occurring approximately 50 ms after error commission at fronto-central electrode sites and is thought to reflect the activation of a generic error monitoring system. Several studies have reported an increased ERN in clinically anxious children, and suggest that anxious children are more sensitive to error commission—although the mechanisms underlying this association are not clear. We have previously found that punishing errors results in a larger ERN, an effect that persists after punishment ends. It is possible that learning-related experiences that impact sensitivity to errors may lead to an increased ERN. In particular, punitive parenting might sensitize children to errors and increase their ERN. We tested this possibility in the current study by prospectively examining the relationship between parenting style during early childhood and children’s ERN approximately three years later. Initially, 295 parents and children (approximately 3 years old) participated in a structured observational measure of parenting behavior, and parents completed a self-report measure of parenting style. At a follow-up assessment approximately three years later, the ERN was elicited during a Go/No-Go task, and diagnostic interviews were completed with parents to assess child psychopathology. Results suggested that both observational measures of hostile parenting and self-report measures of authoritarian parenting style uniquely predicted a larger ERN in children 3 years later. We previously reported that children in this sample with anxiety disorders were characterized by an increased ERN. A mediation analysis indicated that ERN magnitude mediated the relationship between harsh parenting and child anxiety disorder. Results suggest that parenting may shape children’s error processing through environmental conditioning and thereby risk for anxiety, although future work is needed to confirm this hypothesis. PMID:25092483

Error-Related Brain Activity in Young Children: Associations with Parental Anxiety and Child Temperamental Negative Emotionality

ERIC Educational Resources Information Center

Torpey, Dana C.; Hajcak, Greg; Kim, Jiyon; Kujawa, Autumn J.; Dyson, Margaret W.; Olino, Thomas M.; Klein, Daniel N.

2013-01-01

Background: There is increasing interest in error-related brain activity in anxiety disorders. The error-related negativity (ERN) is a negative deflection in the event-related potential approximately 50 [milliseconds] after errors compared to correct responses. Recent studies suggest that the ERN may be a biomarker for anxiety, as it is positively…

Survey of upper band chorus and ECH waves: Implications for the diffuse aurora

NASA Astrophysics Data System (ADS)

Meredith, Nigel; Horne, Richard; Thorne, Richard; Anderson, Roger

2010-05-01

The origin of the diffuse aurora has been a source of controversy for many years. More recently the question has taken a new significance in view of the associated changes in atmospheric chemistry which may affect the middle atmosphere. Here we use CRRES data to assess the importance of upper band chorus and electron cyclotron harmonic (ECH) waves in the production of the diffuse aurora. Both wave modes increase with increasing geomagnetic activity, suggesting they are related to periods of enhanced convection and/or substorm activity. They are confined to the near-equatorial region which excludes the pre-noon sector from the wave survey. During active conditions intense ECH waves and upper band chorus, with amplitudes exceeding 1 mVm-1, are observed in the region 4 < L < 7 from 2100 to 0600 MLT approximately 20% and 6% of the time respectively. This suggests that both wave modes can put electrons on strong diffusion, but only during active conditions and not at all local times. Scattering rates fall below the strong diffusion limit at other times when the wave amplitudes are weaker. Fluxes of low energy electrons (100 eV < E < 30 keV) also increase with increasing geomagnetic activity in approximately the same region of geospace as the waves, suggesting that these electrons are responsible for the generation of the waves. The patterns of the upper band chorus, ECH waves and low energy electrons are similar to the global morphology of the diffuse aurora, suggesting that both wave modes play significant roles in the production of the diffuse aurora.

Prospective observation of physical activity in critically ill patients who were intubated for more than 48 hours.

PubMed

Berney, Susan C; Rose, Joleen W; Bernhardt, Julie; Denehy, Linda

2015-08-01

Critical illness can result in impaired physical function. Increased physical activity, additional to rehabilitation, has demonstrated improved functional independence at hospital discharge. The purpose of this study was to measure patterns of physical activity in a group of critically ill patients. This was a single-center, open, observational behavioral mapping study performed in a quaternary intensive care unit (ICU) in Melbourne, Australia. Observations were collected every 10 minutes for 8 hours between 8:00 am and 5:00 pm with the highest level of physical activity, patient location, and persons present at the bedside recorded. Two thousand fifty observations were collected across 8 days. Patients spent more than 7 hours in bed (median [interquartile range] of 100% [69%-100%]) participating in little or no activity for approximately 7 hours of the day (median [interquartile range] 96% [76%-96%]). Outside rehabilitation, no activities associated with ambulation were undertaken. Patients who were ventilated at the time of observation compared with those who were not were less likely to be out of bed (98% reduction in odds). Patients spent up to 30% of their time alone. Outside rehabilitation, patients in ICU are inactive and spend approximately one-third of the 8-hour day alone. Strategies to increase physical activity levels in ICU are required. Copyright © 2015 Elsevier Inc. All rights reserved.

Brain hyperthermia and temperature fluctuations during sexual interaction in female rats.

PubMed

Mitchum, Robert D; Kiyatkin, Eugene A

2004-03-12

Since the metabolic activity of neural cells is accompanied by heat release, brain temperature monitoring provides insight into behavior-associated changes in neural activity. In the present study, local temperatures were continuously recorded in several brain structures (nucleus accumbens, medial-preoptic hypothalamus and hippocampus) and a non-locomotor head muscle (musculus temporalis) in a receptive female rat during sexually arousing stimulation and subsequent copulatory behavior with an experienced male. Placement of the male into a neighboring compartment increased the female's temperature (approximately 0.8 degrees C) and additional, transient increases (approximately 0.2 degrees C) occurred when the rats were allowed to see and smell each other through a transparent barrier. Temperatures gradually increased further as the male repeatedly mounted and achieved intromissions, peaked 2-3 min after male's ejaculation (0.2-0.4 degrees C), and abruptly dropped until the male initiated a new copulatory cycle. Similar biphasic fluctuations accompanied subsequent copulatory cycles. Although both arousal-related temperature increases and biphasic fluctuations associated with copulatory cycles were evident in each recording location, brain sites showed consistently faster and stronger increases than the muscle, suggesting metabolic brain activation as the primary source of brain temperature fluctuations and a force behind associated changes in brain temperature. Robust brain hyperthermia and the generally similar pattern of phasic temperature fluctuations associated with individual events of sexual interaction found in males and females suggest widespread neural activation (motivational arousal) as a driving force underlying this cooperative motivated behavior in animals of both sexes. Females, however, showed different temperature changes in association with the initial (first mount or intromission) and final (ejaculation) events of each copulatory cycle, suggesting sex-specific differences in neural activity associated with the initiation and regulation of sexual behavior.

Increased PI3-kinase in presympathetic brain areas of the spontaneously hypertensive rat.

PubMed

Veerasingham, Shereeni J; Yamazato, Masanobu; Berecek, Kathleen H; Wyss, J Michael; Raizada, Mohan K

2005-02-18

Existing evidence led us to hypothesize that increases in p85alpha, a regulatory subunit of PI3-kinase, in presympathetic brain areas contribute to hypertension. PI3-kinase p85alpha, p110alpha, and p110delta mRNA was 1.5- to 2-fold higher in the paraventricular nucleus (PVN) of spontaneously hypertensive rats (SHR) compared with their controls, Wistar Kyoto rats (WKY). The increase in p85alpha/p110delta was attenuated in SHR treated with captopril, an angiotensin (Ang)-converting enzyme inhibitor, from in utero to 6 months of age. In the rostral ventrolateral medulla (RVLM), p110delta mRNA was approximately 2-fold higher in SHR than in WKY. Moreover, the increases in mRNA were associated with higher PI3-kinase activity in both nuclei. The functional relevance was studied in neuronal cultures because SHR neurons reflect the augmented p85alpha mRNA and PI3-kinase activity. Expression of a p85 dominant-negative mutant decreased norepinephrine (NE) transporter mRNA and [3H]NE uptake by approximately 60% selectively in SHR neurons. In summary, increased p85alpha/p110delta expression in the PVN and RVLM is associated with increased PI3-kinase activity in the SHR. Furthermore, normalized PI3-kinase p85alpha/p110delta expression within the PVN might contribute to the overall effect of captopril, perhaps attributable to a consequent decrease in NE availability.

Signaling via the CD2 receptor enhances HTLV-1 replication in T lymphocytes.

PubMed

Guyot, D J; Newbound, G C; Lairmore, M D

1997-07-21

Human T lymphotropic virus type 1 (HTLV-1) is considered the etiologic agent of adult T cell leukemia/lymphoma and several chronic progressive immune-mediated diseases. Approximately 1-4% of infected individuals develop disease, generally decades following infection. Increased proviral transcription, mediated by the viral 40-kDa trans-activating protein, Tax, has been implicated in the pathogenesis of HTLV-1-associated diseases. Since the HTLV-1 promoter contains sequences responsive to cyclic AMP and protein kinase C, we hypothesized that lymphocyte activation signals initiated through the TCR/CD3 complex or CD2 receptor promote viral replication in HTLV-1-infected lymphocytes. We demonstrate that mAbs directed against the CD2, but not the CD3 receptor increase viral p24 capsid protein 1.5- to 5.7-fold in CD2/CD3+ HTLV-1-infected cell culture supernatants. Northern blot analysis demonstrated a 2.5- to 4-fold increase in all species of viral mRNA following CD2 cross-linking of OSP2/4 cells, an immortalized HTLV-1 cell line. Consistent with transcriptional regulation, reporter gene activity increased approximately 11-fold in CD2-stimulated Jurkat T cells cotransfected with a Tax-expressing plasmid and a CAT reporter gene construct under control of the HTLV-1 promoter. These data suggest a possible physiologic mechanism, whereby CD2-mediated cell adhesion and lymphocyte activation may promote viral transcription in infected lymphocytes.

Charcoal as a capture material for silver nanoparticles in the aquatic environment

NASA Astrophysics Data System (ADS)

McGillicuddy, Eoin; Morrison, Liam; Cormican, Martin; Morris, Dearbháile

2017-04-01

Background: The reported antibacterial activity of silver nanoparticles (AgNPs) has led to their incorporation into numerous consumer products including; textiles, domestic appliances, food containers, cosmetics, paints, medical and medicinal products. The AgNPs incorporated into these products can be released into the environment and aquatic system during their production, use and end of life disposal. In the aquatic environment, uncertainties surround the concentration, fate and effects of AgNPs. The aim of this project is to examine charcoal as a potential material for capture of silver nanoparticles from the aquatic environment. Material/methods: Activated charcoal is a commonly used filter material and was selected for this project to determine its suitability as a capture material for AgNPs in water samples. Activated charcoal (Norit® CA1 (Sigma-Aldrich)) was exposed to 100 ppb, 25 nm PVP coated AgNPs (nanoComposix) prepared in Milli-Q water. These solutions were exposed to unaltered charcoal granules for 20 hours after which the decrease of silver in the solution was measured using ICP-MS. In order to improve the removal, the surface area of the charcoal was increased firstly by grinding with a pestle and mortar and secondly by milling the charcoal. The milled charcoal was prepared using an agate ball mill running at 500 rpm for 5 minutes. The activated charcoal was then exposed to samples containing 10 ppb AgNPs. Results: In the initial tests, approximately 10% of the silver was removed from the water samples using the unaltered activated charcoal granules. Further experiments were carried out to compare the unaltered granules with the ground and milled charcoal. These tests were carried out similarly to the previous test however lower concentration of 10 ppb was used. After 20 hours of exposure the granule samples, as previously, showed approximately a 10% reduction in silver content with the ground charcoal giving approximately 30% reduction in silver concentration and in the sample exposed to milled charcoal, approximately 60% reduction in silver concentration was observed. These tests found that increasing the surface area of the charcoal increased the silver reduction in the solution. Conclusions: Data suggest that charcoal may be a suitable material for use in the capture of AgNPs from water samples

Development of tolerance to the effects of vigabatrin (gamma-vinyl-GABA) on GABA release from rat cerebral cortex, spinal cord and retina.

PubMed Central

Neal, M. J.; Shah, M. A.

1990-01-01

1. The effects of acute and chronic vigabatrin (gamma-vinyl-GABA) (GVG) administration on gamma-aminobutyric acid (GABA) levels and release in rat cortical slices, spinal cord slices and retinas were studied. 2. GVG (250 mgkg-1 i.p.) administered to rats 18 h before death (acute administration) produced an almost 3 fold increase in GABA levels of the cortex and spinal cord and a 6 fold increase in retinal GABA. The levels of glutamate, aspartate, glycine and taurine were unaffected. 3. When GVG (250 mgkg-1 i.p.) was administered daily for 17 days (chronic administration) a similar (almost 3 fold) increase in cortical GABA occurred but the increases in spinal and retinal GABA were reduced by approximately 40%. 4. Acute administration of GVG strikingly increased the potassium-evoked release (KCl 50 mM) of GABA from all three tissues. This enhanced evoked release was reduced by about 50% in tissues taken from rats that had been chronically treated with GVG. 5. Acute administration of GVG reduced GABA-transaminase (GABA-T) activity by approximately 80% in cortex and cord and by 98% in the retina. Following the chronic administration of GVG, there was a trend for GABA-T activities to recover (significant only in cortex). Acute administration of GVG had no effect on glutamic acid decarboxylase (GAD) activity in cortex or spinal cord. However, chronic treatment resulted in significant decreases in GAD activity in both the cortex and cord (35% and 50% reduction respectively).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2379037

Responses of alkaline phosphatase activity to phosphorus stress in Daphnia magna.

PubMed

McCarthy, S D S; Rafferty, S P; Frost, P C

2010-01-15

We examined how alkaline phosphatase (AP) activity within the bodies and in the materials released by the crustacean Daphnia magna responds to variable algal food phosphorus (P)-content. We found that Daphnia eating P-poor food (C:P approximately 700) had significantly higher AP activity in their bodies on a mass-specific basis compared with individuals eating P-rich food (C:P approximately 100). This dietary P effect on AP activity was not altered by Daphnia starvation but was partially related to differences in the P concentration of animal body homogenates. By contrast, poor P-nutrition of Daphnia lowered AP activity in released materials compared with that measured from their P-sufficient conspecifics. Moreover, AP activity in Daphnia release was lowest in animals consuming P-poor food for longer time periods. Our results support the hypothesis that AP activity increases inside P-limited Daphnia as a mechanism to increase P-acquisition and retention from ingested algae in these nutritionally stressed animals. The lower level of AP activity present in the water of P-deprived animals could reflect a change from largely free to membrane-bound AP isotypes in the digestive tracts of P-starved animals or a decrease in the shedding of membrane-anchored AP from their intestinal lining. These results supplement accumulating evidence that P-poor algal food reduces the dietary mineral P available to Daphnia. In addition, animal body AP activity measurements, with some refinement, may prove useful as an in situ indicator of P-stress in aquatic consumers.

Channeling by Proximity: The Catalytic Advantages of Active Site Colocalization Using Brownian Dynamics.

PubMed

Bauler, Patricia; Huber, Gary; Leyh, Thomas; McCammon, J Andrew

2010-05-06

Nature often colocalizes successive steps in a metabolic pathway. Such organization is predicted to increase the effective concentration of pathway intermediates near their recipient active sites and to enhance catalytic efficiency. Here, the pathway of a two-step reaction is modeled using a simple spherical approximation for the enzymes and substrate particles. Brownian dynamics are used to simulate the trajectory of a substrate particle as it diffuses between the active site zones of two different enzyme spheres. The results approximate distances for the most effective reaction pathways, indicating that the most effective reaction pathway is one in which the active sites are closely aligned. However, when the active sites are too close, the ability of the substrate to react with the first enzyme was hindered, suggesting that even the most efficient orientations can be improved for a system that is allowed to rotate or change orientation to optimize the likelihood of reaction at both sites.

Enhanced expression of rat hepatic CYP2B1/2B2 and 2E1 by pyridine: differential induction kinetics and molecular basis of expression.

PubMed

Kim, H; Putt, D; Reddy, S; Hollenberg, P F; Novak, R F

1993-11-01

Expression of the cytochrome P450 (CYP) 2B subfamily in rat and rabbit hepatic tissues after pyridine (PY) treatment has been examined, and the molecular basis for enhanced 2B1/2B2 expression has been determined. P450 expression was monitored using metabolic activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses, and the identity of the proteins was confirmed through N-terminus microsequence analysis. PY caused a dose-dependent elevation of hepatic CYP2B1/B2B levels in rats, which ranged from 4- to 22-fold over the dosing regimen of 100 to 400 mg PY/kg/day, for 3 days, respectively. PY at low dose failed to induce CYP2B in rabbit hepatic tissue, suggesting a species-dependent response in 2B expression. Anti-2B1 IgG addition to PY-induced microsomes inhibited benzphetamine N-demethylase activity by only approximately 15%, in sharp contrast to the approximately 73% inhibition observed for phenobarbital-induced microsomes, suggesting the induction of other form(s) of P450 having benzphetamine N-demethylase activity. Northern blot analysis revealed that PY treatment increased 2B1 and 2B2 poly(A)+ RNA levels approximately 69- and approximately 34-fold, respectively, whereas the 2E1 poly(A)+ RNA levels failed to increase. The results of this study show that PY induces CYP2B1/2B2 and that induction is species-dependent and kinetically distinguishable from 2E1 induction. Moreover, 2B1/2B2 induction occurs as a result of elevated mRNA levels associated with either transcriptional activation or mRNA stabilization, and it differs from the mechanism of hepatic 2E1 induction by PY.

The pH Requirement for in Vivo Activity of the Iron-Deficiency-Induced "Turbo" Ferric Chelate Reductase (A Comparison of the Iron-Deficiency-Induced Iron Reductase Activities of Intact Plants and Isolated Plasma Membrane Fractions in Sugar Beet).

PubMed Central

Susin, S.; Abadia, A.; Gonzalez-Reyes, J. A.; Lucena, J. J.; Abadia, J.

1996-01-01

The characteristics of the Fe reduction mechanisms induced by Fe deficiency have been studied in intact plants of Beta vulgaris and in purified plasma membrane vesicles from the same plants. In Fe-deficient plants the in vivo Fe(III)-ethylenediaminetetraacetic complex [Fe(III)-EDTA] reductase activity increased over the control values 10 to 20 times when assayed at a pH of 6.0 or below ("turbo" reductase) but increased only 2 to 4 times when assayed at a pH of 6.5 or above. The Fe(III)-EDTA reductase activity of root plasma membrane preparations increased 2 and 3.5 times over the controls, irrespective of the assay pH. The Km for Fe(III)-EDTA of the in vivo ferric chelate reductase in Fe-deficient plants was approximately 510 and 240 [mu]M in the pH ranges 4.5 to 6.0 and 6.5 to 8.0, respectively. The Km for Fe(III)-EDTA of the ferric chelate reductase in intact control plants and in plasma membrane preparations isolated from Fe-deficient and control plants was approximately 200 to 240 [mu]M. Therefore, the turbo ferric chelate reductase activity of Fe-deficient plants at low pH appears to be different from the constitutive ferric chelate reductase. PMID:12226175

The pH Requirement for in Vivo Activity of the Iron-Deficiency-Induced "Turbo" Ferric Chelate Reductase (A Comparison of the Iron-Deficiency-Induced Iron Reductase Activities of Intact Plants and Isolated Plasma Membrane Fractions in Sugar Beet).

PubMed

Susin, S.; Abadia, A.; Gonzalez-Reyes, J. A.; Lucena, J. J.; Abadia, J.

1996-01-01

The characteristics of the Fe reduction mechanisms induced by Fe deficiency have been studied in intact plants of Beta vulgaris and in purified plasma membrane vesicles from the same plants. In Fe-deficient plants the in vivo Fe(III)-ethylenediaminetetraacetic complex [Fe(III)-EDTA] reductase activity increased over the control values 10 to 20 times when assayed at a pH of 6.0 or below ("turbo" reductase) but increased only 2 to 4 times when assayed at a pH of 6.5 or above. The Fe(III)-EDTA reductase activity of root plasma membrane preparations increased 2 and 3.5 times over the controls, irrespective of the assay pH. The Km for Fe(III)-EDTA of the in vivo ferric chelate reductase in Fe-deficient plants was approximately 510 and 240 [mu]M in the pH ranges 4.5 to 6.0 and 6.5 to 8.0, respectively. The Km for Fe(III)-EDTA of the ferric chelate reductase in intact control plants and in plasma membrane preparations isolated from Fe-deficient and control plants was approximately 200 to 240 [mu]M. Therefore, the turbo ferric chelate reductase activity of Fe-deficient plants at low pH appears to be different from the constitutive ferric chelate reductase.

Associations Between Sedentary Behavior, Physical Activity, and Out-of-Pocket Health Care Expenditure: Evidence From Chinese Older Adults.

PubMed

Yu, Hongjun; Schwingel, Andiara

2018-06-12

This study examined the associations between sedentary behavior, physical activity, and health care expenditures among Chinese older adults. We conducted a survey on 4,165 older men and women living in major cities in China. Sedentary behavior and physical activity were measured by the Physical Activity Scale for the Elderly (PASE) questionnaire. Healthcare costs were assessed by self-reported out-of-pocket health care expenditures across outpatient care, inpatient care, medication, and formal caregiver expenses. Sedentary behavior was associated with an increase in annual out-of-pocket health care expenditures by approximately USD$37 for each additional sedentary hour (p < 0.001). Physical activity was associated with a decrease in annual health care expenditures by approximately USD$1.2 for each 1 PASE score (p < 0.001). Physical activity was a less salient indicator of health care expenditure for men than women. Reducing sedentary behavior among older men and women and promoting physical activity, especially among men, may be important strategies to reduce out-of-pocket health care expenditures in China.

Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices

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

Stratton, K.R.; Worley, P.F.; Huganir, R.L.

The authors have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipidmore » system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation.« less

LDL oxidation by platelets propagates platelet activation via an oxidative stress-mediated mechanism.

PubMed

Carnevale, Roberto; Bartimoccia, Simona; Nocella, Cristina; Di Santo, Serena; Loffredo, Lorenzo; Illuminati, Giulio; Lombardi, Elisabetta; Boz, Valentina; Del Ben, Maria; De Marco, Luigi; Pignatelli, Pasquale; Violi, Francesco

2014-11-01

Platelets generate oxidized LDL (ox-LDL) via NOX2-derived oxidative stress. We investigated if once generated by activated platelets ox-LDL can propagate platelet activation. Experiments were performed in platelets from healthy subjects (HS), hyper-cholesterolemic patients and patients with NOX2 hereditary deficiency. Agonist-stimulated platelets from HS added with LDL were associated with a dose-dependent increase of reactive oxidant species and ox-LDL. Agonist-stimulated platelets from HS added with a fixed dose of LDL (57.14 μmol/L) or added with homogenized human atherosclerotic plaque showed enhanced ox-LDL formation (approximately +50% and +30% respectively), which was lowered by a NOX2 inhibitor (approximately -35% and -25% respectively). Compared to HS, ox-LDL production was more pronounced in agonist-stimulated platelet rich plasma (PRP) from hyper-cholesterolemic patients but was almost absent in PRP from NOX2-deficient patients. Platelet aggregation and 8-iso-PGF2α-ΙΙΙ formation increased in LDL-treated washed platelets (+42% and +53% respectively) and PRP (+31% and +53% respectively). Also, LDL enhanced platelet-dependent thrombosis at arterial shear rate (+33%) but did not affect platelet activation in NOX2-deficient patients. Platelet activation by LDL was significantly inhibited by CD36 or LOX1 blocking peptides, two ox-LDL receptor antagonists, or by a NOX2 inhibitor. LDL-added platelets showed increased p38MAPK (+59%) and PKC (+51%) phosphorylation, p47(phox) translocation to platelet membrane (+34%) and NOX2 activation (+30%), which were inhibited by ox-LDL receptor antagonists. Platelets oxidize LDL, which in turn amplify platelet activation via specific ox-LDL receptors; both effects are mediated by NOX2 activation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Expression of the nifBfdxNnifOQ region of Azotobacter vinelandii and its role in nitrogenase activity.

PubMed Central

Rodríguez-Quiñones, F; Bosch, R; Imperial, J

1993-01-01

The nifBQ transcriptional unit of Azotobacter vinelandii has been previously shown to be required for activity of the three nitrogenase systems, Mo nitrogenase, V nitrogenase, and Fe nitrogenase, present in this organism. We studied regulation of expression and the role of the nifBQ region by means of translational beta-galactosidase fusions to each of the five open reading frames: nifB, orf2 (fdxN), orf3 (nifO), nifQ, and orf5. Expression of the first three open reading frames was observed under all three diazotrophic conditions; expression of orf5 was never observed. Genes nifB and fdxN were expressed at similar levels. With Mo, expression of nifO and nifQ was approximately 20- and approximately 400-fold lower than that of fdxN, respectively. Without Mo, expression of nifB dropped three- to fourfold and that of nifQ dropped to the detection limit. However, expression of nifO increased threefold. The products of nifB, fdxN, nifO, and nifQ have been visualized in A. vinelandii as beta-galactosidase fusion proteins with the expected molecular masses. The NifB- fusion lacked activity for any of the three nitrogenase systems and showed an iron-molybdenum cofactor-deficient phenotype in the presence of Mo. The FdxN- mutation resulted in reduced nitrogenase activities, especially when V was present. Dinitrogenase activity in extracts was similarly affected, suggesting a role of FdxN in iron-molybdenum cofactor synthesis. The NifO(-)-producing mutation did not affect any of the nitrogenases under standard diazotrophic conditions. The NifQ(-)-producing mutation resulted in an increased (approximately 1,000-fold) Mo requirement for Mo nitrogenase activity, a phenotype already observed with Klebsiella pneumoniae. No effect of the NifQ(-)-producing mutation on V or Fe nitrogenase was found; this is consistent with its very low expression under those conditions. Mutations in orf5 had no effect on nitrogenase activity. Images PMID:8491713

Systematic Review of Theory-Based Interventions Aimed at Increasing Physical Activity in Individuals with Spinal Cord Injury

ERIC Educational Resources Information Center

Wilroy, Jereme; Knowlden, Adam

2016-01-01

Background: Approximately 200,000 individuals have a spinal cord injury (SCI) and more than 12,000 new cases are diagnosed each year in the United States. Lowered physical functioning caused by SCI often leads to a sedentary lifestyle, increasing risk for chronic diseases, secondary medical conditions, and lower quality of life. Purpose: The aim…

Increasing the Participation of Parents of Elementary School Students in Parent Education Activities through Development and Implementation of an Alternative Delivery System.

ERIC Educational Resources Information Center

Walker, Thomas

This practicum report describes a program intended to increase parent participation by improved information delivery at an elementary school. Background study of the school and community indicated approximately a 25% turnover rate of new families and students. Attendance at parent education workshops and school orientation tours before program…

Gain of function AMP-activated protein kinase γ3 mutation (AMPKγ3R200Q) in pig muscle increases glycogen storage regardless of AMPK activation.

PubMed

Scheffler, Tracy L; Park, Sungkwon; Roach, Peter J; Gerrard, David E

2016-06-01

Chronic activation of AMP-activated protein kinase (AMPK) increases glycogen content in skeletal muscle. Previously, we demonstrated that a mutation in the ryanodine receptor (RyR1(R615C)) blunts AMPK phosphorylation in longissimus muscle of pigs with a gain of function mutation in the AMPKγ3 subunit (AMPKγ3(R200Q)); this may decrease the glycogen storage capacity of AMPKγ3(R200Q) + RyR1(R615C) muscle. Therefore, our aim in this study was to utilize our pig model to understand how AMPKγ3(R200Q) and AMPK activation contribute to glycogen storage and metabolism in muscle. We selected and bred pigs in order to generate offspring with naturally occurring AMPKγ3(R200Q), RyR1(R615C), and AMPKγ3(R200Q) + RyR1(R615C) mutations, and also retained wild-type littermates (control). We assessed glycogen content and parameters of glycogen metabolism in longissimus muscle. Regardless of RyR1(R615C), AMPKγ3(R200Q) increased the glycogen content by approximately 70%. Activity of glycogen synthase (GS) without the allosteric activator glucose 6-phosphate (G6P) was decreased in AMPKγ3(R200Q) relative to all other genotypes, whereas both AMPKγ3(R200Q) and AMPKγ3(R200Q) + RyR1(R615C) muscle exhibited increased GS activity with G6P. Increased activity of GS with G6P was not associated with increased abundance of GS or hexokinase 2. However, AMPKγ3(R200Q) enhanced UDP-glucose pyrophosphorylase 2 (UGP2) expression approximately threefold. Although UGP2 is not generally considered a rate-limiting enzyme for glycogen synthesis, our model suggests that UGP2 plays an important role in increasing flux to glycogen synthase. Moreover, we have shown that the capacity for glycogen storage is more closely related to the AMPKγ3(R200Q) mutation than activity. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Neurolinguistic approach to natural language processing with applications to medical text analysis.

PubMed

Duch, Włodzisław; Matykiewicz, Paweł; Pestian, John

2008-12-01

Understanding written or spoken language presumably involves spreading neural activation in the brain. This process may be approximated by spreading activation in semantic networks, providing enhanced representations that involve concepts not found directly in the text. The approximation of this process is of great practical and theoretical interest. Although activations of neural circuits involved in representation of words rapidly change in time snapshots of these activations spreading through associative networks may be captured in a vector model. Concepts of similar type activate larger clusters of neurons, priming areas in the left and right hemisphere. Analysis of recent brain imaging experiments shows the importance of the right hemisphere non-verbal clusterization. Medical ontologies enable development of a large-scale practical algorithm to re-create pathways of spreading neural activations. First concepts of specific semantic type are identified in the text, and then all related concepts of the same type are added to the text, providing expanded representations. To avoid rapid growth of the extended feature space after each step only the most useful features that increase document clusterization are retained. Short hospital discharge summaries are used to illustrate how this process works on a real, very noisy data. Expanded texts show significantly improved clustering and may be classified with much higher accuracy. Although better approximations to the spreading of neural activations may be devised a practical approach presented in this paper helps to discover pathways used by the brain to process specific concepts, and may be used in large-scale applications.

Physical fitness and performance. Cardiorespiratory fitness in girls-change from middle to high school.

PubMed

Pfeiffer, Karin A; Dowda, Marsha; Dishman, Rod K; Sirard, John R; Pate, Russell R

2007-12-01

To determine how factors are related to change in cardiorespiratory fitness (CRF) across time in middle school girls followed through high school. Adolescent girls (N = 274, 59% African American, baseline age = 13.6 +/- 0.6 yr) performed a submaximal fitness test (PWC170) in 8th, 9th, and 12th grades. Height, weight, sports participation, and physical activity were also measured. Moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were determined by the number of blocks reported on the 3-Day Physical Activity Recall (3DPAR). Individual differences and developmental change in CRF were assessed simultaneously by calculating individual growth curves for each participant, using growth curve modeling. Both weight-relative and absolute CRF increased from 8th to 9th grade and decreased from 9th to 12th grade. On average, girls lost 0.16 kg.m.min.kg.yr in weight-relative PWC170 scores (P < 0.01) and gained 10.3 kg.m.min.yr in absolute PWC170 scores. Girls reporting two or more blocks of MVPA or one or more blocks of VPA at baseline showed an average increase in PWC170 scores of 0.40-0.52 kg.m.min.kg.yr (weight relative) and 22-28 kg.m.min.yr (absolute) in CRF. In weight-relative models, girls with higher BMI showed lower CRF (approximately 0.37 g.m.min.kg.yr), but this was not shown in absolute models. In absolute models, white girls (approximately 40 kg.m.min.yr) and sport participants (approximately 28 kg.m.min.yr) showed an increase in CRF over time. Although there were fluctuations in PWC170 scores across time, average scores decreased during 4 yr. Physical activity was related to change in CRF over time; BMI, race, and sport participation were also important factors related to change over time in CRF (depending on expression of CRF-weight-relative vs absolute). Subsequent research should focus on explaining the complex longitudinal interactions between CRF, physical activity, race, BMI, and sports participation.

Activation of MAP kinase kinase (MEK) and Ras by cholecystokinin in rat pancreatic acini.

PubMed

Duan, R D; Zheng, C F; Guan, K L; Williams, J A

1995-06-01

Cholecystokinin (CCK) has recently been shown to activate mitogen-activated protein (MAP) kinase in rat pancreatic acini [Duan and Williams, Am. J. Physiol. 267 (Gastrointest. Liver Physiol. 30): G401-G408, 1994]. To evaluate the mechanism of MAP kinase activation, we studied the effects of CCK on MAP kinase kinase (MEK) in rat pancreatic acini. Two forms of MEK were identified by immunoblotting, using antibodies specific to MEK1 and MEK2. MEK activity in acinar extracts and after immunoprecipitation with anti-MEK was detected using a recombinant fusion protein, glutathione S-transferase-MAP kinase, as a substrate. MEK activity rapidly increased after stimulation of acini by CCK, with significant stimulation at 1 min and a maximal effect at 5 min, followed by a slow decline to slightly above control levels after 30 min. The threshold concentration of CCK was approximately 10 pM, and the maximal effect was induced by 1 nM CCK, which increased MEK activity by 120%. In addition to CCK, bombesin and carbachol, but not secretin or vasoactive intestinal peptide, enhanced MEK activity. Phorbol ester mimicked the effect of CCK, whereas ionomycin and thapsigargin failed to activate MEK. We further studied the activation of Ras, an important component leading to activation of MEK by growth factors. Ras in acini was immunoprecipitated and identified by Western blotting. CCK and 12-O-tetradecanoylphorbol-13-acetate stimulated the incorporation of GTP into Ras, a requirement for its activation, reaching a maximum at 10 min of approximately 120% over control. In conclusion, the activation of MAP kinase by CCK can be explained by activation of MEK and may involve the activation of Ras by a protein kinase C-dependent mechanism.

Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

2016-01-01

Fire history within the northern larch forests of Central Siberia was studied (65 + deg N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase and observed to be about 80 years at 64 deg N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approximately 71 deg + N). Northward FRI increase correlated with incoming solar radiation (r = -0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase.

Electromyographic activity and 6RM strength in bench press on stable and unstable surfaces.

PubMed

Saeterbakken, Atle H; Fimland, Marius S

2013-04-01

The purpose of the study was to compare 6-repetition maximum (6RM) loads and muscle activity in bench press on 3 surfaces, namely, stable bench, balance cushion, and Swiss ball. Sixteen healthy, resistance-trained men (age 22.5 ± 2.0 years, stature 1.82 ± 6.6 m, and body mass 82.0 ± 7.8 kg) volunteered for 3 habituation/strength testing sessions and 1 experimental session. In randomized order on the 3 surfaces, 6RM strength and electromyographic activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were assessed. Relative to stable bench, the 6RM strength was approximately 93% for balance cushion (p ≤ 0.001) and approximately 92% for Swiss ball (p = 0.008); the pectoralis major electromyographic (EMG) activity was approximately 90% using the balance cushion (p = 0.080) and approximately 81% using Swiss ball (p = 0.006); the triceps EMG was approximately 79% using the balance cushion (p = 0.028) and approximately 69% using the Swiss ball (p = 0.002). Relative to balance cushion, the EMG activity in pectoralis, triceps, and erector spinae using Swiss ball was approximately 89% (p = 0.016), approximately 88% (p = 0.014) and approximately 80% (p = 0.020), respectively. In rectus abdominis, the EMG activity relative to Swiss ball was approximately 69% using stable bench (p = 0.042) and approximately 65% using the balance cushion (p = 0.046). Similar EMG activities between stable and unstable surfaces were observed for deltoid anterior, biceps brachii, and oblique external. In conclusion, stable bench press had greater 6RM strength and triceps and pectoralis EMG activity compared with the unstable surfaces. These findings have implications for athletic training and rehabilitation, because they demonstrate an inferior effect of unstable surfaces on muscle activation of prime movers and strength in bench press. If an unstable surface in bench press is desirable, a balance cushion should be chosen instead of a Swiss ball.

Activity of aspargate (cathepsin D), cysteine proteases (cathepsins B, B + L, and H), and matrix metallopeptidase (collagenase) and their influence on protein and water-holding capacity of muscle in commercially farmed atlantic halibut (Hippoglossus hippoglossus L.).

PubMed

Hagen, Orjan; Solberg, Christel; Johnston, Ian A

2008-07-23

Atlantic halibut (Hippoglossus hippoglossus L.) were commercially farmed in Helgeland, Norway (May 2004-May 2005). The average weight (Mb) of fish increased over the 12 month production cycle by approximately 73% for females and approximately 50% for males, although during the winter months (November-early May) Mb was unchanged in females and declined by 18% in males because of sexual maturation and sperm release. Periods of zero or negative growth were associated with up to 5.7% (females) and 17.9% (males) decline in fast muscle protein content. The activities of cathepsins B, B + L, H, and D showed a reciprocal relationship and were highly correlated with the changes in protein content. Water-holding capacity was measured as the liquid loss increased from 3-5% in November to 11-13% in May. Two general additive models (GAMs) showed that cathepsin B + L, cathepsin D, and collagenase explained 73.1% of the total variance in protein content, while cathepsin H was the largest contributor to liquid loss, explaining approximately 48.8% of the total variance. The results indicate that to obtain the best flesh quality Atlantic halibut should be harvested in the fall or early winter when the liquid loss and cathepsin activities are low and less likely to cause problems during secondary processing and storage.

Reproductive health issues in Greece.

PubMed

Hassan, E; Creatsas, G

1999-06-01

To evaluate reproductive health issues in Greece. Analysis of hospital data and national registry reports. The rate of population growth in Greece is declining and is now 0.99% p.a. The maternal mortality ratio is approximately 3.6 per 100,000 live births, and perinatal and infant mortality are approximately 10/1,000 and 16/1,000 respectively. However, only 28-30% of sexually active women use contraception and approximately 300,000 terminations are performed each year. Sexually transmitted diseases are less common than in 1985: the incidence of syphilis is less than 4 per 100,000 population and that of gonorrhoea is less than 25/100,000. Between 1984 and September 1996, 1,421 cases of AIDS were reported; of these, 1,252 (88.1%) were in men and 169 (11.9%) in women. The incidence of human papilloma virus infection increased and at least 30% of sexually active women are infected. Good reproductive health is of major importance to women and health agencies but there are still significant obstacles to overcome in some regions.

Seasonal changes in serum gonadal steroids associated with migration, mating, and nesting in the loggerhead sea turtle (Caretta caretta).

PubMed

Wibbels, T; Owens, D W; Limpus, C J; Reed, P C; Amoss, M S

1990-07-01

Adult male loggerhead sea turtles, Caretta caretta, exhibited a "prenuptial" spermatogenic cycle that was coincident with increased concentrations of serum testosterone (T). Serum T was high during the months when migration and mating have been recorded for males. In contrast to females, males appear to be annual breeders. Nine reproductively active female C. caretta (as verified through laparoscopy) were tagged with sonic transmitters and were repeatedly bled prior to migration. Four months prior to the nesting season, the ovaries of reproductively active females had hundreds of vitellogenic follicles of approximately 1.5 cm in diameter (i.e., half the size of ovulatory follicles). Approximately 4-6 weeks prior to migration from feeding grounds to mating and nesting areas, serum estradiol-17 beta (E2) concentrations increased significantly and remained high for approximately 4 weeks, suggesting a period of increased vitellogenesis. During a 1- to 2-week period prior to migration, serum E2 decreased significantly, while serum T concentrations increased (at least) until the time of migration. Serum T, E2, and progesterone (PRO) were elevated during nesting if a turtle was going to nest again during that nesting season. During the last nesting of a season, turtles had low serum concentrations of T, E2, and Pro. The prenuptial pattern of gonadal recrudescence and gonadal steroid production in both male and female C. caretta contrasts with those of many temperate freshwater turtles, and this type of reproductive pattern may have been facilitated by adaptation to a tropical marine environment.

The effects of simultaneous hyperlipemia-hyperglycemia on the resistance arteries, myocardium and kidney glomeruli.

PubMed

Costache, G; Popov, D; Georgescu, A; Cenuse, M; Jinga, V V; Simionescu, M

2000-01-01

The experimental model of Golden Syrian hamster subjected to concomitant hyperlipemia (diet-induced) and diabetes (by streptozotocin injection) for 24 weeks is characterised by the prevalence of micro- and macroangiopathies. We have used the hyperlipemic-diabetic (HD) hamsters to investigate: a) whether there is an alteration in the reactivity of the resistance arteries (mean internal diameter: 210-250 microm), b) if present, which are the structural and biochemical changes that accompany the functional modifications, and c) to examine the pathomorphological changes induced by the association of hyperlipemia and diabetes on vital organs such as myocardium and kidney glomeruli. To these aims, biochemical assays of plasma components, light- and electronmicroscopy, myographic, morphometric and spectrofluorimetric techniques were used. The mesenteric resistance arteries of HD hamsters exhibited (as compared to similar arteries in normals) a decreased contractile response to noradrenaline (1.86+/-0.35 vs. 2.43+/-0.21), and an impeded endothelium dependent relaxation to acetylcholine (approximately 61.40% vs. approximately 79.80%). The association of hyperlipemia with diabetes induced changes in morphology of the resistance arteries consisting in approximately 10% increase of the intima plus media cross-sectional area, approximately 20% decrease of the vascular lumen area, and approximately 2.85 fold augmentation of the wall to lumen ratio. The resistance arteries exhibited structural modifications of the endothelium (up to 8 copies of Weibel-Palade bodies/endothelial cell), and smooth muscle cells (secretory phenotype), and in the vessels media small calcification cores appeared embedded in a hyperplasic extracellular matrix. The vascular mesenteric bed of the HD hamsters contained approximately 2.30 and approximately 1.30 fold increased concentrations of AGE-collagen and pentosidine, respectively, above the normal values. The HD hamsters displayed also modifications that may be dependent on or may lead to an increase in blood pressure, such as: a) approximately 2 fold increase in the activity of serum angiotensin converting enzyme; b) approximately 4.8 fold enhancement of erythrocytes fragility (as a measure of the oxidative stress); c) left ventricular hypertrophy associated with a progressive disarray of cardiomyocyte contractile fibers, interruptions of the Z bands, and accumulation of collagen-rich extracellular matrix indicative of interstitial fibrosis; d) the kidney glomerular capillaries appeared partially or totally collapsed, with a thickened basement membrane which appeared polymorphic, and in some locations made up of successive layers connected by fine bridges and intercalated nodules; in addition, an increase (approximately 1.50 fold) of the mesangial volume was indicative of glomerulosclerosis.

Determinants of relaxation rate in rabbit skinned skeletal muscle fibres

PubMed Central

Luo, Ye; Davis, Jonathan P; Smillie, Lawrence B; Rall, Jack A

2002-01-01

The influence of Ca2+-activated force, the rate of dissociation of Ca2+ from troponin C (TnC) and decreased crossbridge detachment rate on the time course of relaxation induced by flash photolysis of diazo-2 in rabbit skinned psoas fibres was investigated at 15 °C. The rate of relaxation increased as the diazo-2 chelating capacity (i.e. free [diazo-2]/free [Ca2+]) increased. At a constant diazo-2 chelating capacity, the rate of relaxation was independent of the pre-photolysis Ca2+-activated force in the range 0.3-0.8 of maximum isometric force. A TnC mutant that exhibited increased Ca2+ sensitivity caused by a decreased Ca2+ dissociation rate in solution (M82Q TnC) also increased the Ca2+ sensitivity of steady-state force and decreased the rate of relaxation in fibres by approximately twofold. In contrast, a TnC mutant with decreased Ca2+ sensitivity caused by an increased Ca2+ dissociation rate in solution (NHdel TnC) decreased the Ca2+ sensitivity of steady-state force but did not accelerate relaxation. Decreasing the rate of crossbridge kinetics by reducing intracellular inorganic phosphate concentration ([Pi]) slowed relaxation by approximately twofold and led to two phases of relaxation, a slow linear phase followed by a fast exponential phase. In fibres, M82Q TnC further slowed relaxation in low [Pi] conditions by approximately twofold, whereas NHdel TnC had no significant effect on relaxation. These results are consistent with the interpretation that the Ca2+-dissociation rate and crossbridge detachment rate are similar in fast-twitch skeletal muscle, such that decreasing either rate slows relaxation, but accelerating Ca2+ dissociation has little effect on relaxation. PMID:12482894

Identification of cholinergic and non-cholinergic neurons in the pons expressing phosphorylated cyclic adenosine monophosphate response element-binding protein as a function of rapid eye movement sleep.

PubMed

Datta, S; Siwek, D F; Stack, E C

2009-09-29

Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of rapid eye movement (REM) sleep. In the present study performed on rats, phosphorylated cyclic AMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high rapid eye movement sleep (HR, approximately 27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With HR, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low rapid eye movement sleep (LR, approximately 2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr=0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr=0.88), PnO (Rsqr=0.87), and SubCD (Rsqr=0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr=0.70) and DRN (Rsqr=0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are inactive. More importantly, the regression analysis indicated that pCREB activation in approximately 98% of PPT cholinergic neurons, was caused by REM sleep. Moreover the results indicate that during REM sleep, PPT intracellular PKA activation and a transcriptional cascade involving pCREB occur exclusively in the cholinergic neurons.

Differential effects of dopamine and opioid receptor blockade on motivated Coca-Cola drinking behavior and associated changes in brain, skin and muscle temperatures.

PubMed

Kiyatkin, E A

2010-05-05

Although pharmacological blockade of both dopamine (DA) and opiate receptors has an inhibiting effect on appetitive motivated behaviors, it is still unclear which physiological mechanisms affected by these treatments underlie the behavioral deficit. To clarify this issue, we examined how pharmacological blockade of either DA (SCH23390+eticlopride at 0.2 mg/kg each) or opioid receptors (naloxone 1 mg/kg) affects motor activity and temperature fluctuations in the nucleus accumbens (NAcc), temporal muscle, and facial skin associated with motivated Coca-Cola drinking behavior in rats. In drug-free conditions, presentation of a cup containing 5 ml of Coca-Cola induced locomotor activation and rapid NAcc temperature increases, which both transiently decreased during drinking, and phasically increased again after the cup was emptied. Muscle temperatures followed this pattern, but increases were weaker and more delayed than those in the NAcc. Skin temperature rapidly dropped after cup presentation, remained at low levels during consumption, and slowly restored during post-consumption behavioral activation. By itself, DA receptor blockade induced robust decrease in spontaneous locomotion, moderate increases in brain and muscle temperatures, and a relative increase in skin temperatures, suggesting metabolic activation coupled with adynamia. Following this treatment (approximately 180 min), motor activation to cup presentation and Coca-Cola consumption were absent, but rats showed NAcc and muscle temperature increases following cup presentation comparable to control. Therefore, DA receptor blockade does not affect significantly central and peripheral autonomic responses to appetitive stimuli, but eliminates their behavior-activating effects, thus disrupting appetitive behavior and blocking consumption. Naloxone alone slightly decreased brain and muscle temperatures and increased skin temperatures, pointing at the enhanced heat loss and possible minor inhibition of basal metabolic activity. This treatment (approximately 60 min) had minimal effects on the latencies of drinking, but increased its total duration, with licking interrupted by pauses and retreats. This behavioral attenuation was coupled with weaker than in control locomotor activation and diminished temperature fluctuations in each recording location. Therefore, attenuation of normal behavioral and physiological responses to appetitive stimuli appears to underlie modest inhibiting effects of opiate receptor blockade on motivated behavior and consumption. (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

gamma-Glutamyl transpeptidase overexpression increases metastatic growth of B16 melanoma cells in the mouse liver.

PubMed

Obrador, Elena; Carretero, Julian; Ortega, Angel; Medina, Ignacio; Rodilla, Vicente; Pellicer, José A; Estrela, José M

2002-01-01

B16 melanoma (B16M) cells with high glutathione (GSH) content show rapid proliferation in vitro and high metastatic activity in the liver in vivo. gamma-Glutamyl transpeptidase (GGT)-mediated extracellular GSH cleavage and intracellular GSH synthesis were studied in vitro in B16M cells with high (F10) and low (F1) metastatic potential. GGT activity was modified by transfection with the human GGT gene (B16MF1/Tet-GGT cells) or by acivicin-induced inhibition. B16MF1/Tet-GGT and B16MF10 cells exhibited higher GSH content (35 +/- 6 and 40 +/- 5 nmol/10(6) cells, respectively) and GGT activity (89 +/- 9 and 37 +/- 7 mU/10(6) cells, respectively) as compared (P <.05) with B16MF1 cells (10 +/- 3 nmol GSH and 4 mU GGT/10(6) cells). Metastasis (number of foci/100 mm(3) of liver) increased in B16MF1 cells pretreated with GSH ester ( approximately 3-fold, P <.01), and decreased in B16MF1/Tet-GGT and B16MF10 cells pretreated with the GSH synthesis inhibitor L-buthionine (S,R)-sulphoximine ( approximately 5-fold and 2-fold, respectively, P <.01). Liver, kidney, brain, lung, and erythrocyte GSH content in B16MF1/Tet-GGT- or B16MF10-bearing mice decreased as compared with B16MF1- and non-tumor-bearing mice. Organic anion transporting polypeptide 1-independent sinusoidal GSH efflux from hepatocytes increased in B16MF1/Tet-GGT- or B16MF10-bearing mice ( approximately 2-fold, P <.01) as compared with non-tumor-bearing mice. Our results indicate that tumor GGT activity and an intertissue flow of GSH can regulate GSH content of melanoma cells and their metastatic growth in the liver.

Association between obesity and depressive symptoms among U.S. Military active duty service personnel, 2002.

PubMed

Kress, Amii M; Peterson, Michael R; Hartzell, Michael C

2006-03-01

The association between obesity and depression remains equivocal. The purpose of this study was to describe the prevalence and association of obesity and depressive symptoms among military personnel. A cross-sectional analysis was performed using data (N=10,040) from the U.S. Department of Defense (DoD) Survey of Health-Related Behaviors. Prevalence odds ratios were calculated to describe the association between obesity and depressive symptoms. Approximately 10% of active duty men and 4% of active duty women were obese. The prevalence of depressive symptoms ranged from approximately 16% of overweight men to 49% of obese women. Obese men and women and underweight men had increased odds of depressive symptoms as compared with normal-weight individuals. The DoD should emphasize prevention and regular screening for obesity and depressive symptoms to improve readiness and reduce health care costs and disease burden in this cohort.

Change in frozen soils and its effect on regional hydrology, upper Heihe basin, northeastern Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Gao, Bing; Yang, Dawen; Qin, Yue; Wang, Yuhan; Li, Hongyi; Zhang, Yanlin; Zhang, Tingjun

2018-02-01

Frozen ground has an important role in regional hydrological cycles and ecosystems, particularly on the Qinghai-Tibetan Plateau (QTP), which is characterized by high elevations and a dry climate. This study modified a distributed, physically based hydrological model and applied it to simulate long-term (1971-2013) changes in frozen ground its the effects on hydrology in the upper Heihe basin, northeastern QTP. The model was validated against data obtained from multiple ground-based observations. Based on model simulations, we analyzed spatio-temporal changes in frozen soils and their effects on hydrology. Our results show that the area with permafrost shrank by 8.8 % (approximately 500 km2), predominantly in areas with elevations between 3500 and 3900 m. The maximum depth of seasonally frozen ground decreased at a rate of approximately 0.032 m decade-1, and the active layer thickness over the permafrost increased by approximately 0.043 m decade-1. Runoff increased significantly during the cold season (November-March) due to an increase in liquid soil moisture caused by rising soil temperatures. Areas in which permafrost changed into seasonally frozen ground at high elevations showed especially large increases in runoff. Annual runoff increased due to increased precipitation, the base flow increased due to changes in frozen soils, and the actual evapotranspiration increased significantly due to increased precipitation and soil warming. The groundwater storage showed an increasing trend, indicating that a reduction in permafrost extent enhanced the groundwater recharge.

On the Star Formation-AGN Connection at zeta (is) approximately greater than 0.3

NASA Technical Reports Server (NTRS)

LaMassa, Stephanie M.; Heckman, T. M.; Ptak, Andrew; Urry, C. Megan

2013-01-01

Using the spectra of a sample of approximately 28,000 nearby obscured active galaxies from Data Release 7 of the Sloan Digital Sky Survey (SDSS), we probe the connection between active galactic nucleus (AGN) activity and star formation over a range of radial scales in the host galaxy. We use the extinction-corrected luminosity of the [O iii] 5007A line as a proxy of intrinsic AGN power and supermassive black hole (SMBH) accretion rate. The star formation rates (SFRs) are taken from the MPA-JHU value-added catalog and are measured through the 3 inch SDSS aperture. We construct matched samples of galaxies covering a range in redshifts. With increasing redshift, the projected aperture size encompasses increasing amounts of the host galaxy. This allows us to trace the radial distribution of star formation as a function of AGN luminosity. We find that the star formation becomes more centrally concentrated with increasing AGN luminosity and Eddington ratio. This implies that such circumnuclear star formation is associated with AGN activity, and that it increasingly dominates over omnipresent disk star formation at higher AGN luminosities, placing critical constraints on theoretical models that link host galaxy star formation and SMBH fueling. We parameterize this relationship and find that the star formation on radial scales (is) less than 1.7 kpc, when including a constant disk component, has a sub-linear dependence on SMBH accretion rate: SFR in proportion to solar mass(sup 0.36), suggesting that angular momentum transfer through the disk limits accretion efficiency rather than the supply from stellar mass loss.

Purification of a d-Mannose Isomerase from Mycobacterium smegmatis1

PubMed Central

Hey-Ferguson, Ann; Elbein, Alan D.

1970-01-01

An enzyme, d-mannose ketol isomerase, catalyzing the isomerization of d-mannose and d-fructose was purified approximately 60-fold from cells of Mycobacterium smegmatis grown on mannose as the sole carbon source. This enzyme was shown to catalyze the conversion of d-mannose and d-lyxose to ketoses. The ketose produced from mannose was identified as fructose by chemical and chromatographic methods. The reaction was shown to be reversible, the equilibrium ratio of fructose to mannose being approximately 65 to 35. The pH optimum was about 7.5, and the Km for mannose was estimated to be 7 × 10−3m. Mannose isomerase activity was greatest in cells grown on mannose, whereas cells grown on fructose had about 30% as much activity. Very low levels of activity were detected in cells grown on other substrates. There was an immediate increase in enzyme activity on transfer of cells from nutrient broth to a mannose mineral salts medium. PMID:5438047

Simulating effects of fire disturbance and climate change on boreal forest productivity and evapotranspiration.

PubMed

Kang, Sinkyu; Kimball, John S; Running, Steven W

2006-06-01

We used a terrestrial ecosystem process model, BIOME-BGC, to investigate historical climate change and fire disturbance effects on regional carbon and water budgets within a 357,500 km(2) portion of the Canadian boreal forest. Historical patterns of increasing atmospheric CO2, climate change, and regional fire activity were used as model drivers to evaluate the relative effects of these impacts to spatial patterns and temporal trends in forest net primary production (NPP) and evapotranspiration (ET). Historical trends of increasing atmospheric CO2 resulted in overall 13% and 5% increases in annual NPP and ET from 1994 to 1996, respectively. NPP was found to be relatively sensitive to changes in air temperature (T(a)), while ET was more sensitive to precipitation (P) change within the ranges of observed climate variability (e.g., +/-2 degrees C for T(a) and +/-20% for P). In addition, the potential effect of climate change related warming on NPP is exacerbated or offset depending on whether these changes are accompanied by respective decreases or increases in precipitation. Historical fire activity generally resulted in reductions of both NPP and ET, which consumed an average of approximately 6% of annual NPP from 1959 to 1996. Areas currently occupied by dry conifer forests were found to be subject to more frequent fire activity, which consumed approximately 8% of annual NPP. The results of this study show that the North American boreal ecosystem is sensitive to historical patterns of increasing atmospheric CO2, climate change and regional fire activity. The relative impacts of these disturbances on NPP and ET interact in complex ways and are spatially variable depending on regional land cover and climate gradients.

Lactic acid bacteria affect serum cholesterol levels, harmful fecal enzyme activity, and fecal water content.

PubMed

Lee, Do Kyung; Jang, Seok; Baek, Eun Hye; Kim, Mi Jin; Lee, Kyung Soon; Shin, Hea Soon; Chung, Myung Jun; Kim, Jin Eung; Lee, Kang Oh; Ha, Nam Joo

2009-06-11

Lactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as lower cholesterol. Although present in many foods, most trials have been in spreads or dairy products. Here we tested whether Bifidobacteria isolates could lower cholesterol, inhibit harmful enzyme activities, and control fecal water content. In vitro culture experiments were performed to evaluate the ability of Bifidobacterium spp. isolated from healthy Koreans (20 approximately 30 years old) to reduce cholesterol-levels in MRS broth containing polyoxyethanylcholesterol sebacate. Animal experiments were performed to investigate the effects on lowering cholesterol, inhibiting harmful enzyme activities, and controlling fecal water content. For animal studies, 0.2 ml of the selected strain cultures (108 approximately 109 CFU/ml) were orally administered to SD rats (fed a high-cholesterol diet) every day for 2 weeks. B. longum SPM1207 reduced serum total cholesterol and LDL levels significantly (p < 0.05), and slightly increased serum HDL. B. longum SPM1207 also increased fecal LAB levels and fecal water content, and reduced body weight and harmful intestinal enzyme activities. Daily consumption of B. longum SPM1207 can help in managing mild to moderate hypercholesterolemia, with potential to improve human health by helping to prevent colon cancer and constipation.

Association of the Duration of Active Pushing With Obstetric Outcomes.

PubMed

Grobman, William A; Bailit, Jennifer; Lai, Yinglei; Reddy, Uma M; Wapner, Ronald J; Varner, Michael W; Caritis, Steve N; Prasad, Mona; Tita, Alan T N; Saade, George; Sorokin, Yoram; Rouse, Dwight J; Blackwell, Sean C; Tolosa, Jorge E

2016-04-01

To estimate the associations between the duration of active pushing during the second stage of labor and maternal and neonatal outcomes. We performed an observational study in which data were obtained by trained abstractors from maternal and neonatal charts of deliveries at 25 hospitals over a 3-year period. In this secondary analysis, women with no prior cesarean delivery who had a term, singleton, cephalic gestation and reached complete dilation were analyzed. The duration of pushing, defined as the time from initiation of pushing to either vaginal delivery or the decision to proceed with a cesarean delivery, was determined. The primary maternal outcome was cesarean delivery and the primary neonatal outcome was a composite that included: mechanical ventilation, proven sepsis, brachial plexus palsy, clavicular fracture, skull fracture, other fracture, seizures, hypoxic-ischemic encephalopathy, or death. Nulliparous and parous women were analyzed separately in univariable and then multivariable analyses. A total of 53,285 women were analyzed. In both nulliparous and parous women, longer duration of pushing was associated with increased odds of both cesarean delivery and the neonatal adverse outcome composite. Nevertheless, even after 4 hours of pushing, approximately 78% of nulliparous women who continued with active pushing had a vaginal delivery and more than 97% did not have the composite adverse neonatal outcome. Similarly, after more than 2 hours of pushing, approximately 82% of parous women who continued active pushing delivered vaginally and more than 97% did not have the adverse neonatal outcome. A longer duration of pushing is associated with an increased relative risk, but small absolute difference in risk, of neonatal complications. Approximately 78% of nulliparous women delivered vaginally even after 4 hours of pushing.

Association of the Duration of Active Pushing With Obstetric Outcomes

PubMed Central

Grobman, William A.; Bailit, Jennifer; Lai, Yinglei; Reddy, Uma M.; Wapner, Ronald J.; Varner, Michael W.; Caritis, Steve N.; Prasad, Mona; Tita, Alan T.N.; Saade, George; Sorokin, Yoram; Rouse, Dwight J.; Blackwell, Sean C.; Tolosa, Jorge E.

2016-01-01

Objective To estimate the associations between the duration of active pushing during the second stage of labor and maternal and neonatal outcomes. Methods We performed an observational study in which data were obtained by trained abstractors from maternal and neonatal charts of deliveries at 25 hospitals over a 3-year period. In this secondary analysis, women with no prior cesarean delivery who had a term, singleton, cephalic gestation and reached complete dilation were analyzed. The duration of pushing, defined as the time from initiation of pushing to either vaginal delivery or the decision to proceed with a cesarean, was determined. The primary maternal outcome was cesarean delivery and the primary neonatal outcome was a composite that included: mechanical ventilation, proven sepsis, brachial plexus palsy, clavicular fracture, skull fracture, other fracture, seizures, hypoxic ischemic encephalopathy, or death. Nulliparous and parous women were analyzed separately in univariable and then multivariable analyses. Results Fifty three thousand two hundred eighty five women were analyzed. In both nulliparous and parous women, longer duration of pushing was associated with increased odds of both cesarean delivery and the neonatal adverse outcome composite. Nevertheless, even after 4 hours of pushing, approximately 78% of nulliparous women who continued with active pushing had a vaginal delivery and over 97% did not have the composite adverse neonatal outcome. Similarly, after more than 2 hours of pushing, approximately 82% of parous women who continued active pushing delivered vaginally and over 97% did not have the adverse neonatal outcome. Conclusion A longer duration of pushing is associated with an increased relative risk, but small absolute difference in risk, of neonatal complications. Approximately 78% of nulliparous women delivered vaginally even after 4 hours of pushing. PMID:26959213

Electrodeposition of Nickel Nanoparticles for the Alkaline Hydrogen Evolution Reaction: Correlating Electrocatalytic Behavior and Chemical Composition.

PubMed

Tao, Shasha; Yang, Florent; Schuch, Jona; Jaegermann, Wolfram; Kaiser, Bernhard

2018-03-09

Ni nanoparticles (NPs) consisting of Ni, NiO, and Ni(OH) 2 were formed on Ti substrates by electrodeposition as electrocatalysts for the hydrogen evolution reaction (HER) in alkaline solution. Additionally, the deposition parameters including the potential range and the scan rate were varied, and the resulting NPs were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy. The chemical composition of the NPs changed upon using different conditions, and it was found that the catalytic activity increased with an increase in the amount of NiO. From these data, optimized NPs were synthesized; the best sample showed an onset potential of approximately 0 V and an overpotential of 197 mV at a cathodic current density of 10 mA cm -2 as well as a small Tafel slope of 88 mV dec -1 in 1 m KOH, values that are comparable to those of Pt foil. These NPs consist of approximately 25 % Ni and Ni(OH) 2 each, as well as approximately 50 % NiO. This implies that to obtain a successful HER electrocatalyst, active sites with differing compositions have to be close to each other to promote the different reaction steps. Long-time measurements (30 h) showed almost complete transformation of the highly active catalyst compound consisting of Ni 0 , NiO, and Ni(OH) 2 into the less active Ni(OH) 2 phase. Nevertheless, the here-employed electrodeposition of nonprecious metal/metal-oxide combination compounds represents a promising alternative to Pt-based electrocatalysts for water reduction to hydrogen. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 66347 - Agency Information Collection Activities; Requests for Comments: Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... Certification Procedures for Changed Products AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... determining the certification basis for aeronautical products. This process is intended to increase safety by... Certification Office by an aircraft/product manufacturer/modifier. Respondents: Approximately 2,558...

A Futile Redox Cycle Involving Neuroglobin Observed at Physiological Temperature.

PubMed

Liu, Anyang; Brittain, Thomas

2015-08-24

Previous studies identifying the potential anti-apoptotic role of neuroglobin raise the question as to how cells might employ neuroglobin to avoid the apoptotic impact of acute hypoxia whilst also avoiding chronic enhancement of tumour formation. We show that under likely physiological conditions neuroglobin can take part in a futile redox cycle. Determination of the rate constants for each of the steps in the cycle allows us to mathematically model the steady state concentration of the active anti-apoptotic ferrous form of neuroglobin under various conditions. Under likely normal physiological conditions neuroglobin is shown to be present in the ferrous state at approximately 30% of its total cellular concentration. Under hypoxic conditions this rapidly rises to approximately 80%. Temporal analysis of this model indicates that the transition from low concentrations to high concentration of ferrous neuroglobin occurs on the seconds time scale. These findings indicate a potential control model for the anti-apoptotic activity of neuroglobin, under likely physiological conditions, whereby, in normoxic conditions, the anti-apoptotic activity of neuroglobin is maintained at a low level, whilst immediately a transition occurs to a hypoxic situation, as might arise during stroke, the anti-apoptotic activity is drastically increased. In this way the cell avoids unwanted increased oncogenic potential under normal conditions, but the rapid activation of neuroglobin provides anti-apoptotic protection in times of acute hypoxia.

Multivalency of Sonic hedgehog conjugated to linear polymer chains modulates protein potency.

PubMed

Wall, Samuel T; Saha, Krishanu; Ashton, Randolph S; Kam, Kimberly R; Schaffer, David V; Healy, Kevin E

2008-04-01

A potently active multivalent form of the protein Sonic hedgehog (Shh) was produced by bioconjugation of a modified recombinant form of Shh to the linear polymers poly(acrylic acid) (pAAc) and hyaluronic acid (HyA) via a two-step reaction exploiting carboimiide and maleimide chemistry. Efficiency of the conjugation was approximately 75% even at stoichiometric ratios of 30 Shh molecules per linear HyA chain (i.e., 30:1 Shh/HyA). Bioactivity of the conjugates was tested via a cellular assay across a range of stoichiometric ratios of Shh molecules to HyA linear chains, which was varied from 0.6:1 Shh/HyA to 22:1 Shh/HyA. Results indicate that low conjugation ratios decrease Shh bioactivity and high ratios increase this activity beyond the potency of monomeric Shh, with approximately equal activity between monomeric soluble Shh and conjugated Shh at 7:1 Shh/HyA. In addition, high-ratio constructs increased angiogenesis determined by the in vivo chick chorioallantoic membrane (CAM) assay. These results are captured by a kinetic model of multiple interactions between the Shh/HyA conjugates and cell surface receptors resulting in higher cell signaling at lower bulk Shh concentrations.

Rapid upregulation of GLUT-4 and MCT-4 expression during 16 h of heavy intermittent cycle exercise.

PubMed

Green, H J; Duhamel, T A; Holloway, G P; Moule, J W; Ranney, D W; Tupling, A R; Ouyang, J

2008-02-01

In this study, we have investigated the hypothesis that an exercise protocol designed to repeatedly induce a large dependence on carbohydrate and large increases in glycolytic flux rate would result in rapid increases in the principal glucose and lactate transporters in working muscle, glucose transporter (GLUT)-4 and monocarboxylate transporter (MCT)4, respectively, and in activity of hexokinase (Hex), the enzyme used to phosphorylate glucose. Transporter abundance and Hex activity were assessed in homogenates by Western blotting and quantitative chemiluminescence and fluorometric techniques, respectively, in samples of tissue obtained from the vastus lateralis in 12 untrained volunteers [peak aerobic power (.VO(2peak)) = 44.3 +/- 2.3 ml.kg(-1).min(-1)] before cycle exercise at repetitions 1 (R1), 2 (R2), 9 (R9), and 16 (R16). The 16 repetitions of the exercise were performed for 6 min at approximately 90% .VO(2peak), once per hour. Compared with R1, GLUT-4 increased (P < 0.05) by 28% at R2 and remained elevated (P < 0.05) at R9 and R16. For MCT-4, increases (P < 0.05) of 24% were first observed at R9 and persisted at R16. No changes were observed in GLUT-1 and MCT-1 or in Hex activity. The approximately 17- to 24-fold increase (P < 0.05) in muscle lactate observed at R1 and R2 was reduced (P < 0.05) to an 11-fold increase at R9 and R16. It is concluded that an exercise protocol designed to strain muscle carbohydrate reserves and to result in large increases in lactic acid results in a rapid upregulation of both GLUT-4 and MCT-4.

Neurolinguistic Approach to Natural Language Processing with Applications to Medical Text Analysis

PubMed Central

Matykiewicz, Paweł; Pestian, John

2008-01-01

Understanding written or spoken language presumably involves spreading neural activation in the brain. This process may be approximated by spreading activation in semantic networks, providing enhanced representations that involve concepts that are not found directly in the text. Approximation of this process is of great practical and theoretical interest. Although activations of neural circuits involved in representation of words rapidly change in time snapshots of these activations spreading through associative networks may be captured in a vector model. Concepts of similar type activate larger clusters of neurons, priming areas in the left and right hemisphere. Analysis of recent brain imaging experiments shows the importance of the right hemisphere non-verbal clusterization. Medical ontologies enable development of a large-scale practical algorithm to re-create pathways of spreading neural activations. First concepts of specific semantic type are identified in the text, and then all related concepts of the same type are added to the text, providing expanded representations. To avoid rapid growth of the extended feature space after each step only the most useful features that increase document clusterization are retained. Short hospital discharge summaries are used to illustrate how this process works on a real, very noisy data. Expanded texts show significantly improved clustering and may be classified with much higher accuracy. Although better approximations to the spreading of neural activations may be devised a practical approach presented in this paper helps to discover pathways used by the brain to process specific concepts, and may be used in large-scale applications. PMID:18614334

Leptin protects cardiomyocytes from serum-deprivation-induced apoptosis by increasing anti-oxidant defence.

PubMed

Zheng, Juan; Fang, Ji; Yin, Yuan-Jun; Wang, Xiao-Chen; Ren, An-Jing; Bai, Jie; Sun, Xue-Jun; Yuan, Wen-Jun; Lin, Li

2010-10-01

1. Leptin, an important adipose-derived hormone, can be associated with cardiac pathophysiology; however, the role of leptin in cardiomyocyte apoptosis is poorly understood. The present study examines serum-deprivation-induced apoptosis in primary cultured cardiomyocytes treated with leptin. 2. Cardiomyocytes were subjected to serum deprivation in the presence or absence of leptin (5 or 50 nmol/L) for 48 h. Apoptosis was determined by Hoechst 33258 and Annexin V-FITC/propidium iodide dual staining. Cell viability, malondialdehyde (MDA) content, caspase 3 activation, and the expression and enzyme activity of superoxide dismutase (SOD) were measured. Small interference RNA (siRNA) targeting SOD1 and SOD2 were used to knockdown their expression and measure apoptosis. 3. Serum deprivation caused nearly 30% of apoptosis in cardiomyocytes, and an approximately 60% decrease in cell viability. The mRNA levels and the activated form of caspase 3 were greatly increased. In the presence of leptin, the apoptotic rate was reduced to approximately 15%, cell viability was increased and the activation of caspase 3 was partially inhibited. Additionally, the augmented lipid peroxidation (MDA formation) was abolished, and the impaired activities of SOD1 and SOD2 were restored by leptin. The mRNA expression of SOD2, but not SOD1, was stimulated by leptin. Transfection with siRNA that cause deficiency of either SOD1 or SOD2 attenuated the anti-apoptotic effects of leptin. 4. The results suggest that leptin inhibits serum-deprivation-induced apoptosis in cardiomyocytes by activating SOD. The present study outlines the direct actions of leptin in cardiac disorders that are related to elevated leptin levels. © 2010 The Authors. Clinical and Experimental Pharmacology and Physiology © 2010 Blackwell Publishing Asia Pty Ltd.

Patterning of somatosympathetic reflexes

NASA Technical Reports Server (NTRS)

Kerman, I. A.; Yates, B. J.

1999-01-01

In a previous study, we reported that vestibular nerve stimulation in the cat elicits a specific pattern of sympathetic nerve activation, such that responses are particularly large in the renal nerve. This patterning of vestibulosympathetic reflexes was the same in anesthetized and decerebrate preparations. In the present study, we report that inputs from skin and muscle also elicit a specific patterning of sympathetic outflow, which is distinct from that produced by vestibular stimulation. Renal, superior mesenteric, and lumbar colonic nerves respond most strongly to forelimb and hindlimb nerve stimulation (approximately 60% of maximal nerve activation), whereas external carotid and hypogastric nerves were least sensitive to these inputs (approximately 20% of maximal nerve activation). In contrast to vestibulosympathetic reflexes, the expression of responses to skin and muscle afferent activation differs in decerebrate and anesthetized animals. In baroreceptor-intact animals, somatosympathetic responses were strongly attenuated (to <20% of control in every nerve) by increasing blood pressure levels to >150 mmHg. These findings demonstrate that different types of somatic inputs elicit specific patterns of sympathetic nerve activation, presumably generated through distinct neural circuits.

Coordinate induction of both cytochrome P4503A and MDR1 by St John's wort in healthy subjects.

PubMed

Dresser, George K; Schwarz, Ute I; Wilkinson, Grant R; Kim, Richard B

2003-01-01

Many drugs are cosubstrates of cytochrome P450 (CYP) 3A and MDR1; furthermore, their disposition is markedly affected by pretreatment with inducing agents, including St John's wort. Such drug interactions reflect induction of both proteins through a common mechanism involving the steroid X receptor/pregnane X receptor. However, the relative contributions of enhanced metabolism and efflux transport to the overall induction process are unknown. The effects of 12 days' pretreatment with St John's wort on the disposition of selected in vivo probe drugs were determined in 21 young healthy subjects. Midazolam after oral and intravenous administration was used to assess CYP3A activity in both the intestinal epithelium and the liver, whereas the disposition of fexofenadine after an oral dose was assumed to be a measure of MDR1 function, and the oral plasma concentration-time profile of cyclosporine (INN, ciclosporin) was considered to reflect both CYP3A and MDR1 activities. St John's wort markedly affected the plasma concentration-time profiles of all of the drugs, with associated increases in their clearance. With midazolam, the enhancement was considerably less after intravenous administration (approximately 1.5-fold) than after oral administration (approximately 2.7-fold), and estimated intestinal and hepatic extraction ratios were higher by approximately 1.2- to 1.4-fold. By contrast, the oral clearances of fexofenadine and cyclosporine were equally increased by approximately 1.6-fold and 1.9-fold, respectively; these changes were both statistically less than for midazolam's oral clearance and greater than its estimated intestinal extraction. Although the disposition of all 3 drugs was altered by St John's wort, the extent of induction measured by oral clearance was different with CYP3A activity (midazolam), apparently increasing more than MDR1 function (fexofenadine), whereas with cyclosporine the change in oral clearance appeared to be more closely associated with the increase in MDR1 rather than CYP3A, despite the fact that both proteins are importantly involved in its disposition. These discordances indicate that, although a common molecular mechanism may be involved, the quantitative aspects of induction are complex and depend on the particular drug and the relative contributions of CYP3A and MDR1 in its disposition.

Variation in microbial activity in histosols and its relationship to soil moisture.

PubMed

Tate, R L; Terry, R E

1980-08-01

Microbial biomass, dehydrogenase activity, carbon metabolism, and aerobic bacterial populations were examined in cropped and fallow Pahokee muck (a lithic medisaprist) of the Florida Everglades. Dehydrogenase activity was two- to sevenfold greater in soil cropped to St. Augustinegrass (Stenotaphrum secundatum (Walt) Kuntz) compared with uncropped soil, whereas biomass ranged from equivalence in the two soils to a threefold stimulation in the cropped soil. Biomass in soil cropped to sugarcane (Saccharum spp. L) approximated that from the grass field, whereas dehydrogenase activities of the cane soil were nearly equivalent to those of the fallow soil. Microbial biomass, dehydrogenase activity, aerobic bacterial populations, and salicylate oxidation rates all correlated with soil moisture levels. These data indicate that within the moisture ranges detected in the surface soils, increased moisture stimulated microbial activity, whereas within the soil profile where moisture ranges reached saturation, increased moisture inhibited aerobic activities and stimulated anaerobic processes.

Variation in Microbial Activity in Histosols and Its Relationship to Soil Moisture †

PubMed Central

Tate, Robert L.; Terry, Richard E.

1980-01-01

Microbial biomass, dehydrogenase activity, carbon metabolism, and aerobic bacterial populations were examined in cropped and fallow Pahokee muck (a lithic medisaprist) of the Florida Everglades. Dehydrogenase activity was two- to sevenfold greater in soil cropped to St. Augustinegrass (Stenotaphrum secundatum (Walt) Kuntz) compared with uncropped soil, whereas biomass ranged from equivalence in the two soils to a threefold stimulation in the cropped soil. Biomass in soil cropped to sugarcane (Saccharum spp. L) approximated that from the grass field, whereas dehydrogenase activities of the cane soil were nearly equivalent to those of the fallow soil. Microbial biomass, dehydrogenase activity, aerobic bacterial populations, and salicylate oxidation rates all correlated with soil moisture levels. These data indicate that within the moisture ranges detected in the surface soils, increased moisture stimulated microbial activity, whereas within the soil profile where moisture ranges reached saturation, increased moisture inhibited aerobic activities and stimulated anaerobic processes. PMID:16345610

Making the Fitness Connection

ERIC Educational Resources Information Center

Brock, Sheri J.; Fittipaldi-Wert, Jeanine

2005-01-01

Children's fitness levels are decreasing at an alarming rate. The Centers for Disease Control has determined that approximately 33% of children do not regularly engage in vigorous physical activity (CDC, 2002). As a result, childhood obesity has increased 100% since 1980 in the United States due to physical inactivity (CDC, 2004). A well-planned…

Interdisciplinary Traffic Safety Instructional System: Series VI.

ERIC Educational Resources Information Center

Maryland State Dept. of Education, Baltimore.

Approximately 120 lessons for increasing sixth grade students' safety knowledge and skills as pedestrians in traffic and at school, as auto and school bus passengers, and as operators of bicycles are provided in this traffic curriculum. One third of the curriculum focuses on perceptual safety activities for young pedestrians, including lessons on…

Statistical Deconvolution for Superresolution Fluorescence Microscopy

PubMed Central

Mukamel, Eran A.; Babcock, Hazen; Zhuang, Xiaowei

2012-01-01

Superresolution microscopy techniques based on the sequential activation of fluorophores can achieve image resolution of ∼10 nm but require a sparse distribution of simultaneously activated fluorophores in the field of view. Image analysis procedures for this approach typically discard data from crowded molecules with overlapping images, wasting valuable image information that is only partly degraded by overlap. A data analysis method that exploits all available fluorescence data, regardless of overlap, could increase the number of molecules processed per frame and thereby accelerate superresolution imaging speed, enabling the study of fast, dynamic biological processes. Here, we present a computational method, referred to as deconvolution-STORM (deconSTORM), which uses iterative image deconvolution in place of single- or multiemitter localization to estimate the sample. DeconSTORM approximates the maximum likelihood sample estimate under a realistic statistical model of fluorescence microscopy movies comprising numerous frames. The model incorporates Poisson-distributed photon-detection noise, the sparse spatial distribution of activated fluorophores, and temporal correlations between consecutive movie frames arising from intermittent fluorophore activation. We first quantitatively validated this approach with simulated fluorescence data and showed that deconSTORM accurately estimates superresolution images even at high densities of activated fluorophores where analysis by single- or multiemitter localization methods fails. We then applied the method to experimental data of cellular structures and demonstrated that deconSTORM enables an approximately fivefold or greater increase in imaging speed by allowing a higher density of activated fluorophores/frame. PMID:22677393

Influence of estradiol and androstenedione on ACTH and cortisol secretion in the ovine fetus.

PubMed

Wood, C E; Saoud, C J

1997-01-01

To test the hypothesis that physiologic increases in fetal plasma 17 beta-estradiol and androstenedione modulate the activity of the fetal hypothalamic-pituitary-adrenal (HPA) axis. Seventeen pregnant ewes and their fetuses were chronically catheterized. At the time of surgery, the fetuses received implants that released 17 beta-estradiol (n = 5) alone or 17 beta-estradiol and androstenedione (n = 6), each at a rate of approximately 250 micrograms/day for each steroid. The control group (n = 6) received either no pellet (n = 2) or a "placebo" pellet, which contained no steroid (n = 4). Fetal blood samples were drawn for hormone and blood gas analysis at 1-3-day intervals until the time of spontaneous parturition. Fetal plasma ACTH and cortisol concentrations were fit to semilogarithmic equations and analyzed by stepwise multiple linear regression analysis for statistically significant effects of 17 beta-estradiol and androstenedione. Estradiol significantly increased and androstenedione significantly decreased the ACTH and cortisol concentrations. Treatment with both 17 beta-estradiol and androstenedione resulted in parturition approximately 4 days earlier than in the other groups (P < .05). Physiologic increases in fetal plasma estradiol and androstenedione modify the activity of the HPA axis.

APPROXIMATE ENZYMIC METHOD OF MICROANALYSIS FOR IDENTIFYING RESIDUAL AMOUNTS OF ORGANOPHOSPHORUS INSECTICIDES,

DTIC Science & Technology

plant extracts gradually increases. This is evidently explained by a conversion of the insecticide into a compound possessing high anticholinesterase activity . (Author)...possible to determine from 1 to 100 micrograms of insecticide per 1 ml. It was established that the anticholinesterase activity of chlorphos when...inherent anticholinesterase action, was developed. In order to realize this method a portable kit was constructed which contains a rack for the storage

A new animal model for modulating myosin isoform expression by altered mechanical activity

NASA Technical Reports Server (NTRS)

Caiozzo, V. J.; Ma, E.; McCue, S. A.; Smith, E.; Herrick, R. E.; Baldwin, K. M.

1992-01-01

The purpose of this study was to develop a new rodent model that is capable of delineating the importance of mechanical loading on myosin heavy chain (MHC) isoform expression of the plantar and dorsi flexor muscles of the ankle. The essential components of this system include 1) stimulating electrodes that are chronically implanted into a muscle, allowing for the control of the activation pattern of the target muscle(s); 2) a training apparatus that translates the moment of the ankle into a linear force; and 3) a computer-controlled Cambridge 310 ergometer. The isovelocity profile of the ergometer ensured that the medial gastrocnemius (MG) produced forces that were > 90% of maximal isometric force (Po), and the eccentric contractions of the tibialis anterior (TA) were typically 120% of Po. Both the concentric and eccentric training programs produced statistically significant increases in the muscle mass of the MG (approximately 15%) and TA (approximately 7%) as well as a decrease in myofibrillar adenosinetriphosphatase activity. Both the white and red regions of the MG and TA exhibited significant increases in the relative content of the type IIa MHC and concomitant decreases in type IIb MHC expression. Although the red regions of the MG and red TA contained approximately 10% type I MHC, the training programs did not affect this isoform. It appears that when a fast-twitch muscle is stimulated at a high frequency (100 Hz) and required to contract either concentrically or eccentrically under high loading conditions, the expression of the type IIa MHC isoform will be upregulated, whereas that of the type IIb MHC will be concomitantly downregulated.

Spatio-temporal dynamics of brain mechanisms in aversive classical conditioning: high-density event-related potential and brain electrical tomography analyses.

PubMed

Pizzagalli, Diego A; Greischar, Lawrence L; Davidson, Richard J

2003-01-01

Social cognition, including complex social judgments and attitudes, is shaped by individual learning experiences, where affect often plays a critical role. Aversive classical conditioning-a form of associative learning involving a relationship between a neutral event (conditioned stimulus, CS) and an aversive event (unconditioned stimulus, US)-represents a well-controlled paradigm to study how the acquisition of socially relevant knowledge influences behavior and the brain. Unraveling the temporal unfolding of brain mechanisms involved appears critical for an initial understanding about how social cognition operates. Here, 128-channel ERPs were recorded in 50 subjects during the acquisition phase of a differential aversive classical conditioning paradigm. The CS+ (two fearful faces) were paired 50% of the time with an aversive noise (CS upward arrow + /Paired), whereas in the remaining 50% they were not (CS upward arrow + /Unpaired); the CS- (two different fearful faces) were never paired with the noise. Scalp ERP analyses revealed differences between CS upward arrow + /Unpaired and CS- as early as approximately 120 ms post-stimulus. Tomographic source localization analyses revealed early activation modulated by the CS+ in the ventral visual pathway (e.g. fusiform gyrus, approximately 120 ms), right middle frontal gyrus (approximately 176 ms), and precuneus (approximately 240 ms). At approximately 120 ms, the CS- elicited increased activation in the left insula and left middle frontal gyrus. These findings not only confirm a critical role of prefrontal, insular, and precuneus regions in aversive conditioning, but they also suggest that biologically and socially salient information modulates activation at early stages of the information processing flow, and thus furnish initial insight about how affect and social judgments operate.

Long-term increase in Karenia brevis abundance along the Southwest Florida Coast

PubMed Central

Brand, Larry E.; Compton, Angela

2008-01-01

Data collected along the southwest coast of Florida between Tampa Bay and Sanibel Island on the abundance of the toxic dinoflagellate Karenia brevis from 1954 to 2002 were examined for spatial and temporal patterns. K. brevis was found to be approximately 20-fold more abundant within 5 km of the shoreline than 20-30 km offshore. Overall, K. brevis was approximately 13-18-fold more abundant in 1994-2002 than in 1954-1963. In 1954-1963, K. brevis occurred primarily in the fall months. In 1994-2002, it was more abundant not only in the fall, but also in the winter and spring months. It is hypothesized that greater nutrient availability in the ecosystem is the most likely cause of this increase in K. brevis biomass, and the large increase in the human population and its activities in South Florida over the past half century is a major factor. PMID:18437245

Variability of lightning activity over India on ENSO time scales

NASA Astrophysics Data System (ADS)

Ahmad, Adnan; Ghosh, Mili

2017-12-01

ENSO, the reliable indicator of inter-annual climate variation of the ocean-atmosphere system in the tropical Pacific region, can affect the overall lightning activity which is another atmospheric phenomenon. In the present study, the impact of the ENSO on the total lightning activity over India has been studied for the period 2004-2014. During the El-Nino period (July 2004-April 2005 and July 2009-April 2010), total number of lightning flashes increased by 10% and 18% respectively and during La-Nina period (July 2010-April 2011 and August 2011 to March 2012), the total number of lightning flashes decreased approximately by 19% and 28% respectively as compared to the mean of corresponding period (2004-14) of the Non-ENSO. Seasonal variation of flash density is also examined for the El-Nino and La-Nina period. The result shows that in the El-Nino period of the pre-monsoon and monsoon seasons, there is an increment in the flash density approximately by 48% and 9% respectively than the Non-ENSO and the spatial variation also having high flash density along the foot of Himalayas region. In the post-monsoon season, there is a marginal change in the flash density between El-Nino and the Non-ENSO. In the winter season, there is an increment in flash density in the El-Nino period approximately by 45% than the Non-ENSO. In the La-Nina period of the pre-monsoon and monsoon seasons, there is the decrement in the flash density approximately by the 44% and 24% respectively than the Non-ENSO. In the Post-monsoon season and winter season of La-Nina, the flash density is increased by about 24% and 33% over India. These findings can be applied to do proper planning of lightning induced hazard mitigation as lightning is of one of the major natural disasters of India.

Association between late-life social activity and motor decline in older adults.

PubMed

Buchman, Aron S; Boyle, Patricia A; Wilson, Robert S; Fleischman, Debra A; Leurgans, Sue; Bennett, David A

2009-06-22

Loss of motor function is a common consequence of aging, but little is known about the factors that predict idiopathic motor decline. Our objective was to test the hypothesis that late-life social activity is related to the rate of change in motor function in old age. Longitudinal cohort study with a mean follow-up of 4.9 years with 906 persons without stroke, Parkinson disease, or dementia participating in the Rush Memory and Aging Project. At baseline, participants rated the frequency of their current participation in common social activities from which a summary measure of social activity was derived. The main outcome measure was annual change in a composite measure of global motor function, based on 9 measures of muscle strength and 9 motor performances. Mean (SD) social activity score at baseline was 2.6 (0.58), with higher scores indicating more frequent participation in social activities. In a generalized estimating equation model, controlling for age, sex, and education, global motor function declined by approximately 0.05 U/y (estimate, 0.016; 95% confidence interval [CI], -0.057 to 0.041 [P = .02]). Each 1-point decrease in social activity was associated with approximately a 33% more rapid rate of decline in motor function (estimate, 0.016; 95% CI, 0.003 to 0.029 [P = .02]). The effect of each 1-point decrease in the social activity score at baseline on the rate of change in global motor function was the same as being approximately 5 years older at baseline (age estimate, -0.003; 95% CI, -0.004 to -0.002 [P<.001]). Furthermore, this amount of motor decline per year was associated with a more than 40% increased risk of death (hazard ratio, 1.44; 95% CI, 1.30 to 1.60) and a 65% increased risk of incident Katz disability (hazard ratio, 1.65; 95% CI, 1.48 to 1.83). The association of social activity with the rate of global motor decline did not vary along demographic lines and was unchanged (estimate, 0.025; 95% CI, 0.005 to 0.045 [P = .01]) after controlling for potential confounders including late-life physical and cognitive activity, disability, global cognition depressive symptoms, body composition, and chronic medical conditions. Less frequent participation in social activities is associated with a more rapid rate of motor function decline in old age.

Development of a Body Shield for Small Animal PET System to Reduce Random and Scatter Coincidences

NASA Astrophysics Data System (ADS)

Wada, Yasuhiro; Yamamoto, Seiichi; Watanabe, Yasuyoshi

2015-02-01

For small animal positron emission tomography (PET) research using high radioactivity, such as dynamic studies, the resulting high random coincidence rate of the system degrades image quality. The random coincidence rate is increased not only by the gamma photons from inside the axial-field-of-view (axial-FOV) of the PET system but also by those from outside the axial-FOV. For brain imaging in small animal studies, significant interference is observed from gamma photons emitted from the body. Single gamma photons from the body enter the axial-FOV and increase the random and scatter coincidences. Shielding against the gamma photons from outside the axial-FOV would improve the image quality. For this purpose, we developed a body shield for a small animal PET system, the microPET Primate 4-ring system, and evaluated its performance. The body shield is made of 9-mm-thick lead and it surrounds most of a rat's body. We evaluated the effectiveness of the body shield using a head phantom and a body phantom with a radioactivity concentration ratio of 1:2 and a maximum total activity of approximately 250 MBq. The random coincidence rate was dramatically decreased to 1/10, and the noise equivalent count rate (NECR) was increased 6 times with an activity of 7 MBq in the head phantom. The true count rate was increased to 35% due to the decrease in system deadtime. The average scatter fraction was decreased to 1/2.5 with the body shield. Count rate measurements of rat were also conducted with an injection activity of approximately 25 MBq of [C-11]N,N-dimethyl-2-(2-amino-4-cyanophenylthio) benzylamine ([C-11]DASB) and approximately 70 and 310 MBq of 2-deoxy-2-(F-18)fluoro-D-glucose ([F-18]FDG). Using the body shield, [F-18]FDG images of rats were improved by increasing the amount of radioactivity injected. The body shield designed for small animal PET systems is a promising tool for improving image quality and quantitation accuracy in small animal molecular imaging research.

Text Messaging: An Intervention to Increase Physical Activity among African American Participants in a Faith-Based, Competitive Weight Loss Program.

PubMed

McCoy, Pamela; Leggett, Sophia; Bhuiyan, Azad; Brown, David; Frye, Patricia; Williams, Bryman

2017-03-29

African American adults are less likely to meet the recommended physical activity guidelines for aerobic and muscle-strengthening activity than Caucasian adults. The purpose of this study was to assess whether a text message intervention would increase physical activity in this population. This pilot study used a pre-/post-questionnaire non-randomized design. Participants in a faith-based weight loss competition who agreed to participate in the text messaging were assigned to the intervention group ( n = 52). Participants who declined to participate in the intervention, but agreed to participate in the study, were assigned to the control group ( n = 30). The text messages provided strategies for increasing physical activity and were based on constructs of the Health Belief Model and the Information-Motivation-Behavioral Skills Model. Chi square tests determined the intervention group participants increased exercise time by approximately eight percent ( p = 0.03), while the control group's exercise time remained constant. The intervention group increased walking and running. The control group increased running. Most participants indicated that the health text messages were effective. The results of this pilot study suggest that text messaging may be an effective method for providing options for motivating individuals to increase physical activity.

Text Messaging: An Intervention to Increase Physical Activity among African American Participants in a Faith-Based, Competitive Weight Loss Program

PubMed Central

McCoy, Pamela; Leggett, Sophia; Bhuiyan, Azad; Brown, David; Frye, Patricia; Williams, Bryman

2017-01-01

African American adults are less likely to meet the recommended physical activity guidelines for aerobic and muscle-strengthening activity than Caucasian adults. The purpose of this study was to assess whether a text message intervention would increase physical activity in this population. This pilot study used a pre-/post-questionnaire non-randomized design. Participants in a faith-based weight loss competition who agreed to participate in the text messaging were assigned to the intervention group (n = 52). Participants who declined to participate in the intervention, but agreed to participate in the study, were assigned to the control group (n = 30). The text messages provided strategies for increasing physical activity and were based on constructs of the Health Belief Model and the Information-Motivation-Behavioral Skills Model. Chi square tests determined the intervention group participants increased exercise time by approximately eight percent (p = 0.03), while the control group’s exercise time remained constant. The intervention group increased walking and running. The control group increased running. Most participants indicated that the health text messages were effective. The results of this pilot study suggest that text messaging may be an effective method for providing options for motivating individuals to increase physical activity. PMID:28353650

Tension responses to rapid pressure release in glycerinated rabbit muscle fibers.

PubMed Central

Fortune, N S; Geeves, M A; Ranatunga, K W

1991-01-01

We have previously shown that the isometric tension of a fully calcium-activated skinned rabbit psoas muscle fiber is reversibly depressed by increased hydrostatic pressure. We report here the characterization of tension transients induced by a rapid (less than 1-ms) release of increased pressure at 12 degrees C. The tension transient consists of three clear phases, an initial further decrease of tension in phase with pressure change followed by two phases of tension increase back to the level recorded at ambient pressure. The mean reciprocal relaxation time for phase 2 (1/tau 2) was approximately 17 s-1 and that for phase 3 (1/tau 3) was 3 s-1. The presence of 20 mM inorganic phosphate markedly increased 1/tau 2 to approximately 52 s-1 and decreased 1/tau 3 to approximately 1.7 s-1. These observations are interpreted in terms of a pressure-sensitive transition between two attached crossbridge states of low (or zero) and higher force. This is compatible with the pressure-sensitive isomerization of actomyosin previously observed in solution. The results presented allow us to propose a coupling between a specific pressure-sensitive isomerization of purified actomyosin, the phosphate release step of the ATPase pathway, and the force-generating event of the cross-bridge cycle. PMID:1871140

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

Venkatraman, A.; Walawender, W.P.; Fan, L.T.

The term, activated carbon, is a generic name for a family of carbonaceous materials with well-developed porosities and consequently, large adsorptive capacities. Activated carbons are increasingly being consumed worldwide for environmental applications such as separation of volatiles from bulk gases and purification of water and waste-water streams. The global annual production is estimated to be around 300 million kilograms, with a rate of increase of 7% each year. Activated carbons can be prepared from a variety of raw materials. Approximately, 60% of the activated carbons generated in the United States is produced from coal; 20%, from coconut shells; and themore » remaining 20% from wood and other sources of biomass. The pore structure and properties of activated carbons are influenced by the nature of the starting material and the initial physical and chemical conditioning as well as the process conditions involved in its manufacture. The porous structures of charcoals and activated carbons obtained by the carbonization of kernels have been characterized.« less

Evidence for changes in the nucleotide conformation in the active site of H(+)-ATPase as determined by pulsed EPR spectroscopy.

PubMed

Schneider, B; Sigalat, C; Amano, T; Zimmermann, J L

2000-12-19

The conformation of di- and triphosphate nucleosides in the active site of ATPsynthase (H(+)-ATPase) from thermophilic Bacillus PS3 (TF1) and their interaction with Mg(2+)/Mn(2+) cations have been investigated using EPR, ESEEM, and HYSCORE spectroscopies. For a ternary complex formed by a stoichiometric mixture of TF1, Mn(2+), and ADP, the ESEEM and HYSCORE data reveal a (31)P hyperfine interaction with Mn(2+) (|A((31)P)| approximately 5.20 MHz), significantly larger than that measured for the complex formed by Mn(2+) and ADP in solution (|A((31)P)| approximately 4.50 MHz). The Q-band EPR spectrum of the Mn.TF1.ADP complex indicates that the Mn(2+) binds in a slightly distorted environment with |D| approximately 180 x 10(-4) cm(-1) and |E| approximately 50 x 10(-4) cm(-1). The increased hyperfine coupling with (31)P in the presence of TF1 reflects the specific interaction between the central Mn(2+) and the ADP beta-phosphate, illustrating the role of the enzyme active site in positioning the phosphate chain of the substrate for efficient catalysis. Results with the ternary Mn.TF1.ATP and Mn.TF1.AMP-PNP complexes are interpreted in a similar way with two hyperfine couplings being resolved for each complex (|A((31)P(beta))| approximately 4.60 MHz and |A((31)P(gamma))| approximately 5.90 MHz with ATP, and |A((31)P(beta))| approximately 4.20 MHz and |A((31)P(gamma))| approximately 5.40 MHz with AMP-PNP). In these complexes, the increased hyperfine coupling with (31)P(gamma) compared with (31)P(beta) reflects the smaller Mn.P distance with the gamma-phosphate compared with the beta-phosphate as found in the crystal structure of the analogous enzyme from mitochondria [3.53 vs 3.70 A (Abrahams, J. P., Leslie, A. G. W., Lutter, R., and Walker, J. E. (1994) Nature 370, 621-628)] and the different binding modes of the two phosphate groups. The ESEEM and HYSCORE data of a complex formed with Mn(2+), ATP, and the isolated beta subunit show that the (31)P hyperfine coupling is close to that measured in the absence of the protein, indicating a poorly structured nucleotide site in the isolated beta subunit in the presence of ATP. The inhibition data obtained for TF1 incubated in the presence of Mg(2+), ADP, Al(NO(3))(3), and NaF indicate the formation of the inhibited complex with the transition state analogue namely Mg.TF1.ADP.AlF(x) with the equilibrium dissociation constant K(D) = 350 microM and rate constant k = 0.02 min(-1). The ESEEM and HYSCORE data obtained for an inhibited TF1 sample, Mn.TF1.ADP.AlF(x), confirm the formation of the transition state analogue with distinct spectroscopic footprints that can be assigned to Mn.(19)F and Mn.(27)Al hyperfine interactions. The (31)P(beta) hyperfine coupling that is measured in the inhibited complex with the transition state analogue (|A((31)P(beta))| approximately 5.10 MHz) is intermediate between those measured in the presence of ADP and ATP and suggests an increase in the bond between Mn and the P(beta) from ADP upon formation of the transition state.

How will the future warming climate impact the river discharge in the alpine mountain region of upper Heihe River Basin?

NASA Astrophysics Data System (ADS)

Wang, Y.; Yang, H.; Yang, D.; Gao, B.; Qin, Y.

2017-12-01

The Tibetan Plateau is more sensitive to the global climate change than other areas due to its special geography. Previous studies have shown that, besides the changes of temperature and precipitation, the changes in the cryosphere such as glacier and frozen ground also have important and far-reaching effects on the ecological and hydrological processes in the basin. In order to reliably predict the future runoff changing trend in the future, it's important to estimate the responses of cryosphere to the future climate change, as well as its impacts on the hydrological processes. Based on typical future climate scenarios (under emission scenario RCP4.5) from five general circulation models (GCMs) and one regional climate model (RCM), as well as a distributed eco-hydrological model (GBEHM), this study analyzes the possible future climate change (from 2011 to 2060) and its impacts on cryospheric and hydrological processes in upper Heihe River Basin, a typical cold mountain region located in the Northeast Tibetan Plateau. The results suggest that air temperature is expected to rise in the future by approximately 0.32 °C/10a, and precipitation is expected to rise slightly by about 3 mm/10a. Under the rising air temperature, the maximum frozen depth of seasonally frozen ground will decrease by about 4.1 cm/10a and the active layer depth of the frozen ground will increase by about 6.2 cm/10a. The runoff is expected to reduce by approximately 6 mm/10a and the evapotranspiration is expected to increase by approximately 9 mm/10a. These changes in hydrological processes are mainly caused by the air temperature rise. The impacts of air temperature change on the hydrological processes are mainly due to the changes of frozen ground. The thickening of active layer of the frozen ground increases the soil storage capacity, leading to the decrease of runoff and increase of evapotranspiration. Results show that, when the active layer depth increase by 1 cm, the runoff will decrease by about 1 2 mm and the evapotranspiration will increase by about 0.7 2 mm. Additionally, the changes from permafrost to seasonal frozen ground increase the groundwater infiltration, which also leads to the decrease of surface runoff.

Pectinesterase inhibitor from jelly-fig (Ficus awkeotsang Makino) achenes reduces methanol content in carambola wine.

PubMed

Wu, James Swi-Bea; Wu, Ming-Chang; Jiang, Chii-Ming; Hwang, Ya-Ping; Shen, Szu-Chuan; Chang, Hung-Min

2005-11-30

Crude pectinesterase (PE) inhibitor (PEI) extracted from jelly-fig achenes (JFA) (Ficus awakeosang Makino) was added to carambola (Averrhoa carambola L.) puree to determine the change in methanol production during fermentation. Addition of pectin or microbial pectic enzyme to puree increased dose-dependently the methanol content in fermented products. Decreasing ratio (from 1:0 to 1:19, v:v) of pectic enzyme to diluted crude PEI solution in the puree-enzyme mixture decreased the PE activity remarkably. Except for transmittance (%T), addition of crude PEI to puree did not affect apparently the physical and chemical properties of wine; however, it reduced methanol content in the control from 256 to 58 ppm. The degree of esterification (DE) of pectin in starting puree was approximately 70%. It decreased to approximately 27% in the control group and reduced slightly to approximately 67% in fermented puree with crude PEI added after 14 days of fermentation. This reveals that crude PEI solution was potent in inhibiting intrinsic carambola PE activity and appeared to be a potential alternative for methanol reduction in wines.

Expanding the study of internet gambling behavior: trends within the Icelandic lottery and sportsbetting platform.

PubMed

Gray, Heather M; Jónsson, Guðberg K; LaPlante, Debi A; Shaffer, Howard J

2015-06-01

As rates of Internet gambling participation increase worldwide, so too does the need to understand how people engage in this form of gambling. This study represents the first examination of actual Internet gambling records within Iceland, a Nordic country with an active Internet lottery market that imposes strict regulations on gambling operator licenses. We summarized electronic betting records of a cohort of subscribers to the Internet betting service provider Íslensk Getspá. We observed that the typical subscriber bet approximately 3 days per month and made fewer than two bets per gambling day, each worth approximately the equivalent of $4 US. Subscribers lost the bulk (96%) of the amount they wagered, for a total loss of approximately $40 across the 2-year window of observation. Although these observations do not support the view of Internet gambling as an activity that is inherently risky for the typical subscriber, we did observe discontinuity across the distributions of gambling behavior, with the top 1% of subscribers making more than three bets per day.

Thermophysical properties of enzyme clarified Lime (Citrus aurantifolia L) juice at different moisture contents.

PubMed

Manjunatha, S S; Raju, P S; Bawa, A S

2014-11-01

Thermophysical properties of enzyme clarified lime (Citrus aurantifolia L.) juice were evaluated at different moisture contents ranging from 30.37 % to 89.30 % (wet basis) corresponding to a water activity range of 0.835 to 0.979. The thermophysical properties evaluated were density, Newtonian viscosity, thermal conductivity, specific heat and thermal diffusivity. The investigation showed that density and Newtonian viscosity of enzyme clarified lime juice decreased significantly (p < 0.05) with increase in moisture content and water activity, whereas thermal conductivity and specific heat increased significantly (p < 0.05) with increase in moisture content and water activity and the thermal diffusivity increased marginally. Empirical mathematical models were established relating to thermophysical properties of enzyme clarified lime juice with moisture content/water activity employing regression analysis by the method of least square approximation. Results indicated the existence of strong correlation between thermophysical properties and moisture content/water activity of enzyme clarified lime juice, a significant (p < 0.0001) negative correlation between physical and thermal properties was observed.

Effect of an ADP analog on isometric force and ATPase activity of active muscle fibers.

PubMed

Karatzaferi, Christina; Myburgh, Kathryn H; Chinn, Marc K; Franks-Skiba, Kathleen; Cooke, Roger

2003-04-01

The role played by ADP in modulating cross-bridge function has been difficult to study, because it is hard to buffer ADP concentration in skinned muscle preparations. To solve this, we used an analog of ADP, spin-labeled ADP (SL-ADP). SL-ADP binds tightly to myosin but is a very poor substrate for creatine kinase or pyruvate kinase. Thus ATP can be regenerated, allowing well-defined concentrations of both ATP and SL-ADP. We measured isometric ATPase rate and isometric tension as a function of both [SL-ADP], 0.1-2 mM, and [ATP], 0.05-0.5 mM, in skinned rabbit psoas muscle, simulating fresh or fatigued states. Saturating levels of SL-ADP increased isometric tension (by P'), the absolute value of P' being nearly constant, approximately 0.04 N/mm(2), in variable ATP levels, pH 7. Tension decreased (50-60%) at pH 6, but upon addition of SL-ADP, P' was still approximately 0.04 N/mm(2). The ATPase was inhibited competitively by SL-ADP with an inhibition constant, K(i), of approximately 240 and 280 microM at pH 7 and 6, respectively. Isometric force and ATPase activity could both be fit by a simple model of cross-bridge kinetics.

75 FR 42489 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Limnanthes...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

... increase species' richness and native plant cover in this edge habitat. In a grazing report prepared for... Lomatium cookii. Excluding overlapping critical habitat units for the two species, a total of approximately... of mining activities can result in direct habitat loss for the species and limit recovery. Indirect...

Monitoring Eruptive Activity at Mount St. Helens with TIR Image Data

NASA Technical Reports Server (NTRS)

Vaughan, R. G.; Hook, S. J.; Ramsey, M. S.; Realmuto, V. J.; Schneider, D. J.

2005-01-01

Thermal infrared (TIR) data from the MASTER airborne imaging spectrometer were acquired over Mount St. Helens in Sept and Oct, 2004, before and after the onset of recent eruptive activity. Pre-eruption data showed no measurable increase in surface temperatures before the first phreatic eruption on Oct 1. MASTER data acquired during the initial eruptive episode on Oct 14 showed maximum temperatures of similar to approximately 330 C and TIR data acquired concurrently from a Forward Looking Infrared (FLIR) camera showed maximum temperatures similar to approximately 675 C, in narrow (approximately 1-m) fractures of molten rock on a new resurgent dome. MASTER and FLIR thermal flux calculations indicated a radiative cooling rate of approximately 714 J/m(exp 2)/s over the new dome, corresponding to a radiant power of approximately 24 MW. MASTER data indicated the new dome was dacitic in composition, and digital elevation data derived from LIDAR acquired concurrently with MASTER showed that the dome growth correlated with the areas of elevated temperatures. Low SO2 concentrations in the plume combined with sub-optimal viewing conditions prohibited quantitative measurement of plume SO2. The results demonstrate that airborne TIR data can provide information on the temperature of both the surface and plume and the composition of new lava during eruptive episodes. Given sufficient resources, the airborne instrumentation could be deployed rapidly to a newly-awakening volcano and provide a means for remote volcano monitoring.

Anthropogenic osmium in rain and snow reveals global-scale atmospheric contamination.

PubMed

Chen, Cynthia; Sedwick, Peter N; Sharma, Mukul

2009-05-12

Osmium is one of the rarer elements in seawater, with typical concentration of approximately 10 x 10(-15) g g(-1) (5.3 x 10(-14) mol kg(-1)). The osmium isotope composition ((187)Os/(188)Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (approximately 1.3) and mantle/cosmic dust (approximately 0.13). Here, we show that the (187)Os/(188)Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (approximately 0.2) that are processed to extract platinum and other metals to be used primarily in automobile catalytic converters. Present-day surface seawater has a lower (187)Os/(188)Os ratio (approximately 0.95) than deep waters, suggesting that human activities have altered the isotope composition of the world's oceans and impacted the global geochemical cycle of osmium. The contamination of the surface ocean is particularly remarkable given that osmium has few industrial uses. The pollution may increase with growing demand for platinum-based catalysts.

Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men

NASA Technical Reports Server (NTRS)

Nakamitsu, S.; Sagawa, S.; Miki, K.; Wada, F.; Nagaya, K.; Keil, L. C.; Drummer, C.; Gerzer, R.; Greenleaf, J. E.; Hong, S. K.

1994-01-01

Effects of water temperature on diuresis, natriuresis, and associated endocrine responses during head-out immersion were studied in eight men during four 5-h experimental conditions: air control at 28 C and immersion at 34.5 C (thermoneutral (Tnt)), 36 C (above Tnt (aTnt)), and 32 C (below Tnt (bTnt). Esophageal temperature decreased by approximately 0.4 C in bTnt and increased by approximately 0.5 C in aTnt. Cardiac output increased by approximately 80% in aTnt and approximately 40% in bTnt while thoracic impedance, an index of central blood pooling, decreased by 7.5 ohms in bTnt (NS vs. Tnt) and 8.8 ohms in aTnt. Total peripheral resistance decreased at all temperatures (50% in aTnt, 20% in bTnt). Urine flow and Na(+) excretion increased by sixfold in bTnt and Tnt but by only threefold in aTnt. Creatinine clearance was unchanged while osmolal clearance (but not free water clearance) increased two-fold with all immersions. Plasma atrial natriuretic peptide (ANP), urinary urodilatin, and urinary guanosine 3',5'-cyclic monophosphate increased while plasma renin activity, aldosterone, and arginine vasopressin (AVP) decreased similarly at all temperatures. bTnt did not potentiate diuresis by selective attenuation of AVP. The overall natriuretic response exhibited a higher correlation with urodilatin than with ANP. Because diuresis and natriuresis were significantly attenuated in aTnt where central blood pooling was greater, we conclude that mechanisms other than the atrial stretch receptor reflex, i.e., urodilatin and effective arterial blood volume, may play more predominant roles in the mechanism of immersion-induced diuresis and natriuresis.

Assessing worldwide research activity on probiotics in pediatrics using Scopus database: 1994-2014.

PubMed

Sweileh, Waleed M; Shraim, Naser Y; Al-Jabi, Samah W; Sawalha, Ansam F; Rahhal, Belal; Khayyat, Rasha A; Zyoud, Sa'ed H

2016-01-01

A wide variety of probiotic products has been introduced into the market in the past decade. Research trends and activity on probiotics help understand how these products were evolved and their potential future role in medicine. The objective of this study was to assess the research activity on probiotics in pediatrics using bibliometric indicators and network visualization. Original and review articles on probiotics in pediatrics published worldwide were retrieved from SciVerse, Scopus (1994-2014) and analyzed. VOSviewer was used for network visualization. The total number of documents published on probiotics in pediatrics was 2817. Research activity on probiotics in pediatrics showed approximately 90- fold increase during the study period. Approximately 22 % of published articles originated from USA and has the greatest share, however, Finland ranked first when data were stratified by population or income. The most productive institution in this field was Turku University in Finland with 82 (2.91 %) articles. Half of the prolific authors were also from Finland. Most of the published research activity appeared in Journal of Pediatric Gastroenterology and Nutrition. Most frequently encountered title terms include nutrition, infant formula, necrotizing enetrocolitis, allergy, and diarrhea. The total number of citations for the retreived documents documents was 70991, and the average citation per article was 25.20. Interest in probiotic research and its potential benefits in pediatric ailments is relatively recent but significantly increasing. Bibliometric analysis can be used as an indicator of the importance and growth of probiotic use in pediatrics.

SOD-1 expression in pig coronary arterioles is increased by exercise training.

PubMed

Rush, J W; Laughlin, M H; Woodman, C R; Price, E M

2000-11-01

Coronary arterioles of exercise-trained (EX) pigs have enhanced nitric oxide (NO.)-dependent dilation. Evidence suggests that the biological half-life of NO. depends in part on the management of the superoxide anion. The purpose of this study was to test the hypothesis that expression of cytosolic copper/zinc-dependent superoxide dismutase (SOD)-1 is increased in coronary arterioles as a result of exercise training. Male Yucatan pigs either remained sedentary (SED, n = 4) or were EX (n = 4) on a motorized treadmill for 16-20 wk. Individual coronary arterioles ( approximately 100-microm unpressurized internal diameter) were dissected and frozen. Coronary arteriole SOD-1 protein (via immunoblots) increased as a result of exercise training (2.16 +/- 0.35 times SED levels) as did SOD-1 enzyme activity (measured via inhibition of pyrogallol autooxidation; approximately 75% increase vs. SED). In addition, SOD-1 mRNA levels (measured via RT-PCR) were higher in EX arterioles (1.68 +/- 0.16 times the SED levels). There were no effects of exercise training on the levels of SOD-2 (mitochondrial), catalase, or p67(phox) proteins. Thus chronic aerobic exercise training selectively increases the levels of SOD-1 mRNA, protein, and enzymatic activity in porcine coronary arterioles. Increased SOD-1 could contribute to the enhanced NO.-dependent dilation previously observed in EX porcine coronary arterioles by improving management of superoxide in the vascular cell environment, thus prolonging the biological half-life of NO.

Increased growth inhibitory effects on human cancer cells and anti-inflammatory potency of shogaols from Zingiber officinale relative to gingerols.

PubMed

Sang, Shengmin; Hong, Jungil; Wu, Hou; Liu, Jing; Yang, Chung S; Pan, Min-Hsiung; Badmaev, Vladimir; Ho, Chi-Tang

2009-11-25

Ginger, the rhizome of the plant Zingiber officinale , has received extensive attention because of its antioxidant, anti-inflammatory, and antitumor activities. Most researchers have considered gingerols as the active principles and have paid little attention to shogaols, the dehydration products of corresponding gingerols during storage or thermal processing. In this study, we have purified and identified eight major components, including three major gingerols and corresponding shogaols, from ginger extract and compared their anticarcinogenic and anti-inflammatory activities. Our results showed that shogaols ([6], [8], and [10]) had much stronger growth inhibitory effects than gingerols ([6], [8], and [10]) on H-1299 human lung cancer cells and HCT-116 human colon cancer cells, especially when comparing [6]-shogaol with [6]-gingerol (IC50 of approximately 8 versus approximately 150 microM). In addition, we found that [6]-shogaol had much stronger inhibitory effects on arachidonic acid release and nitric oxide (NO) synthesis than [6]-gingerol.

G proteins in rat prefrontal cortex (PFC) are differentially activated as a function of oxygen status and PFC region.

PubMed

Hambrecht, V S; Vlisides, P E; Row, B W; Gozal, D; Baghdoyan, H A; Lydic, R

2009-03-01

This study tested the hypothesis that activation of guanine nucleotide binding (G) proteins in rat prefrontal cortex (PFC) is altered by hypoxia. G protein activation by the cholinergic agonist carbachol and the opioid agonist DAMGO was quantified using [(35)S]GTPgammaS autoradiography. G protein activation was expressed as nCi/g tissue in the PFC of 18 rats exposed for 14 consecutive days to sustained hypoxia (10% O(2)), intermittent hypoxia (10% and 21% O(2) alternating every 90 s), or room air (21% O(2)). Relative to basal levels of G protein activation, carbachol and DAMGO increased G protein activation by approximately 70% across all oxygen concentrations. Compared to the room air condition, sustained hypoxia caused a significant increase in G protein activation in frontal association (FrA) region of the PFC. Region-specific comparisons revealed that intermittent and sustained hypoxia caused greater DAMGO-stimulated G protein activation in the FrA than in the pre-limbic (PrL). The data show for the first time that hypoxia increased G protein activation in PFC. The results suggest the potential for hypoxia-induced enhancements in G protein activation to alter PFC function.

Induction of ornithine decarboxylase activity in weanling rat pancreas by an orally administered soy protein isolate.

PubMed

Caldwell, K A

1987-03-15

The induction of ornithine decarboxylase activity in weanling rat pancreas by a trypsin inhibitor-containing soy protein isolate has been studied. Oral administration of the isolate at 0.8, 1.6, 4.0, 6.0, and 8.0 mg/g body wt produced marked elevations in enzyme activity, a response which was proportional to the amount of isolate administered. Ornithine decarboxylase activity was measured at 2, 4, 6, 8, 12, and 24 hr after the isolate was given. A statistically significant increase in enzyme activity was evident as early as 2 hr after treatment; maximal activity occurred at 6 hr and was approximately 140 times greater than the

Pharmacokinetics and pharmacodynamics of vildagliptin in healthy Chinese volunteers.

PubMed

Hu, Pei; Yin, Qi; Deckert, Fabienne; Jiang, Ji; Liu, Dongyang; Kjems, Lise; Dole, William P; He, Yan-Ling

2009-01-01

Vildagliptin is an orally effective, potent, and selective inhibitor of dipeptidyl peptidase IV (DPP-4) that improves glycemic control in patients with type 2 diabetes. This was a randomized, double-blind, placebo-controlled, time-lagged, parallel-group study in a total of 60 healthy Chinese participants. Single- and multiple-dose pharmacokinetics and pharmacodynamics, and safety and tolerability of vildagliptin were assessed following administration of 25, 50, 100, or 200 mg qd, or 50 mg bid. Vildagliptin was rapidly absorbed (tmax 1.5-2.0 hours) across the dose range of 25 to 200 mg and was quickly eliminated with a terminal elimination half-life (t1/2) of approximately 2 hours. Consistent with the short t1/2, no accumulation of vildagliptin was observed following the administration of multiple doses (accumulation factors were 1.00-1.05 across the 25- to 200-mg dose range). Vildagliptin AUC and Cmax values increased in an approximately dose-proportional fashion (dose proportionality constant beta 1.00-1.16). Administration of vildagliptin 25 to 200 mg led to rapid and near-complete (>95%) inhibition of DPP-4 activity for at least 4 hours after dosing, which was associated with increases in plasma active glucagon-like peptide-1 of up to 2- to 3-fold compared with placebo. The duration of DPP-4 inhibition increased with dose. Glucose and insulin levels were not affected by vildagliptin in healthy participants, consistent with the fact that the glucose-lowering effects of vildagliptin occur in a glucose-dependent fashion. Vildagliptin was well tolerated at the highest tested dose of 200 mg qd. Vildagliptin 25 to 200 mg qd exhibits approximately dose-proportional pharmacokinetics with no evidence of accumulation after multiple dosing in healthy Chinese participants. Vildagliptin demonstrates potent inhibition of DPP-4 activity with excellent tolerability at doses of up to and including 200 mg qd.

Shoulder Injuries in US Astronauts Related to EVA Suit Design

NASA Technical Reports Server (NTRS)

Scheuring, R. A.; McCulloch, P.; Van Baalen, Mary; Minard, Charles; Watson, Richard; Blatt, T.

2011-01-01

Introduction: For every one hour spent performing extravehicular activity (EVA) in space, astronauts in the US space program spend approximately six to ten hours training in the EVA spacesuit at NASA-Johnson Space Center's Neutral Buoyancy Lab (NBL). In 1997, NASA introduced the planar hard upper torso (HUT) EVA spacesuit which subsequently replaced the existing pivoted HUT. An extra joint in the pivoted shoulder allows increased mobility but also increased complexity. Over the next decade a number of astronauts developed shoulder problems requiring surgical intervention, many of whom performed EVA training in the NBL. This study investigated whether changing HUT designs led to shoulder injuries requiring surgical repair. Methods: US astronaut EVA training data and spacesuit design employed were analyzed from the NBL data. Shoulder surgery data was acquired from the medical record database, and causal mechanisms were obtained from personal interviews Analysis of the individual HUT designs was performed as it related to normal shoulder biomechanics. Results: To date, 23 US astronauts have required 25 shoulder surgeries. Approximately 48% (11/23) directly attributed their injury to training in the planar HUT, whereas none attributed their injury to training in the pivoted HUT. The planar HUT design limits shoulder abduction to 90 degrees compared to approximately 120 degrees in the pivoted HUT. The planar HUT also forces the shoulder into a forward flexed position requiring active retraction and extension to increase abduction beyond 90 degrees. Discussion: Multiple factors are associated with mechanisms leading to shoulder injury requiring surgical repair. Limitations to normal shoulder mechanics, suit fit, donning/doffing, body position, pre-existing injury, tool weight and configuration, age, in-suit activity, and HUT design have all been identified as potential sources of injury. Conclusion: Crewmembers with pre-existing or current shoulder injuries or certain anthropometric body types should conduct NBL EVA training in the pivoted HUT.

On a Solar Origin for the Cosmogenic Nuclide Event of 775 A.D.

NASA Technical Reports Server (NTRS)

Cliver, E. W.; Tylka, A. J.; Dietrich, W. F.; Ling, A. G.

2014-01-01

We explore requirements for a solar particle event (SPE) and flare capable of producing the cosmogenic nuclide event of 775 A.D., and review solar circumstances at that time. A solar source for 775 would require a greater than 1 GV spectrum approximately 45 times stronger than that of the intense high-energy SPE of 1956 February 23. This implies a greater than 30 MeV proton fluence (F(sub 30)) of approximately 8 × 10(exp 10) proton cm(exp -2), approximately 10 times larger than that of the strongest 3 month interval of SPE activity in the modern era. This inferred F(sub 30) value for the 775 SPE is inconsistent with the occurrence probability distribution for greater than 30 MeV solar proton events. The best guess value for the soft X-ray classification (total energy) of an associated flare is approximately X230 (approximately 9 × 10(exp 33) erg). For comparison, the flares on 2003 November 4 and 1859 September 1 had observed/inferred values of approximately X35 (approximately 10(exp 33) erg) and approximately X45 (approximately 2 × 10(exp 33) erg), respectively. The estimated size of the source active region for a approximately 10(exp 34) erg flare is approximately 2.5 times that of the largest region yet recorded. The 775 event occurred during a period of relatively low solar activity, with a peak smoothed amplitude about half that of the second half of the 20th century. The approximately 1945-1995 interval, the most active of the last approximately 2000 yr, failed to witness a SPE comparable to that required for the proposed solar event in 775. These considerations challenge a recent suggestion that the 775 event is likely of solar origin.

Light-activated protein inhibition through photoinduced electron transfer of a ruthenium(II)–cobalt(III) bimetallic complex

DOE PAGES

Holbrook, Robert J.; Weinberg, David J.; Peterson, Mark D.; ...

2015-02-11

In this paper, we describe a mechanism of light activation that initiates protein inhibitory action of a biologically inert Co(III) Schiff base (Co(III)-sb) complex. Photoinduced electron transfer (PET) occurs from a Ru(II) bipyridal complex to a covalently attached Co(III) complex and is gated by conformational changes that occur in tens of nanoseconds. Reduction of the Co(III)-sb by PET initiates displacement of the inert axial imidazole ligands, promoting coordination to active site histidines of α-thrombin. Upon exposure to 455 nm light, the rate of ligand exchange with 4-methylimidazole, a histidine mimic, increases by approximately 5-fold, as observed by NMR spectroscopy. Similarly,more » the rate of α-thrombin inhibition increases over 5-fold upon irradiation. Finally, these results convey a strategy for light activation of inorganic therapeutic agents through PET utilizing redox-active metal centers.« less

Differential induction of peroxisomal beta-oxidation enzymes by clofibric acid and aspirin in piglet tissues.

PubMed

Yu, X X; Odle, J; Drackley, J K

2001-11-01

Peroxisomal beta-oxidation (POX) of fatty acids is important in lipid catabolism and thermogenesis. To investigate the effects of peroxisome proliferators on peroxisomal and mitochondrial beta-oxidation in piglet tissues, newborn pigs (1-2 days old) were allowed ad libitum access to milk replacer supplemented with 0.5% clofibric acid (CA) or 1% aspirin for 14 days. CA increased ratios of liver weight to body weight (P < 0.07), kidney weight to body weight (P < 0.05), and heart weight to body weight (P < 0.001). Aspirin decreased daily food intake and final body weight but increased the ratio of heart weight to body weight (P < 0.01). In liver, activities of POX, fatty acyl-CoA oxidase (FAO), total carnitine palmitoyltransferase (CPT), and catalase were 2.7-, 2.2-, 1.5-fold, and 33% greater, respectively, for pigs given CA than for control pigs. In heart, these variables were 2.2-, 4.1-, 1.9-, and 1.8-fold greater, respectively, for pigs given CA than for control pigs. CA did not change these variables in either kidney or muscle, except that CPT activity was increased approximately 110% (P < 0.01) in kidney. Aspirin increased only hepatic FAO and CPT activities. Northern blot analysis revealed that CA increased the abundance of catalase mRNA in heart by approximately 2.2-fold. We conclude that 1) POX and CPT in newborn pigs can be induced by peroxisomal proliferators with tissue specificity and 2) the relatively smaller induction of POX in piglets (compared with that in young or adult rodents) may be related to either age or species differences.

Prediabetic nephropathy as an early consequence of the high-calorie/high-fat diet: relation to oxidative stress.

PubMed

Shevalye, Hanna; Lupachyk, Sergey; Watcho, Pierre; Stavniichuk, Roman; Khazim, Khaled; Abboud, Hanna E; Obrosova, Irina G

2012-03-01

This study evaluated early renal functional, structural, and biochemical changes in high-calorie/high-fat diet fed mice, a model of prediabetes and alimentary obesity. Male C57BL6/J mice were fed normal (11 kcal% fat) or high-fat (58 kcal% fat) diets for 16 wk. Renal changes were evaluated by histochemistry and immunohistochemistry, Western blot analysis, ELISA, enzymatic assays, and chemiluminometry. High-fat diet consumption led to increased body and kidney weights, impaired glucose tolerance, hyperinsulinemia, polyuria, a 2.7-fold increase in 24-h urinary albumin excretion, 20% increase in renal glomerular volume, 18% increase in renal collagen deposition, and 8% drop of glomerular podocytes. It also resulted in a 5.3-fold increase in urinary 8-isoprostane excretion and a 38% increase in renal cortex 4-hydroxynonenal adduct accumulation. 4-hydroxynonenal adduct level and immunoreactivity or Sirtuin 1 expression in renal medulla were not affected. Studies of potential mechanisms of the high-fat diet induced renal cortex oxidative injury revealed that whereas nicotinamide adenine dinucleotide phosphate reduced form oxidase activity only tended to increase, 12/15-lipoxygenase was significantly up-regulated, with approximately 12% increase in the enzyme protein expression and approximately 2-fold accumulation of 12(S)-hydroxyeicosatetraenoic acid, a marker of 12/15-lipoxygenase activity. Accumulation of periodic acid-Schiff -positive material, concentrations of TGF-β, sorbitol pathway intermediates, and expression of nephrin, CAAT/enhancer-binding protein homologous protein, phosphoeukaryotic initiation factor-α, and total eukaryotic initiation factor-α in the renal cortex were indistinguishable between experimental groups. Vascular endothelial growth factor concentrations were reduced in high-fat diet fed mice. In conclusion, systemic and renal cortex oxidative stress associated with 12/15-lipoxygenase overexpression and activation is an early phenomenon caused by high-calorie/high-fat diet consumption and a likely contributor to kidney disease associated with prediabetes and alimentary obesity.

Structural Characterizations of Glycerol Kinase: Unraveling Phosphorylation-Induced Long-Range Activation

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

Yeh, Joanne I.; Kettering, Regina; Saxl, Ruth

2009-09-11

Glycerol metabolism provides a central link between sugar and fatty acid catabolism. In most bacteria, glycerol kinase plays a crucial role in regulating channel/facilitator-dependent uptake of glycerol into the cell. In the firmicute Enterococcus casseliflavus, this enzyme's activity is enhanced by phosphorylation of the histidine residue (His232) located in its activation loop, approximately 25 A from its catalytic cleft. We reported earlier that some mutations of His232 altered enzyme activities; we present here the crystal structures of these mutant GlpK enzymes. The structure of a mutant enzyme with enhanced enzymatic activity, His232Arg, reveals that residues at the catalytic cleft aremore » more optimally aligned to bind ATP and mediate phosphoryl transfer. Specifically, the position of Arg18 in His232Arg shifts by approximately 1 A when compared to its position in wild-type (WT), His232Ala, and His232Glu enzymes. This new conformation of Arg18 is more optimally positioned at the presumed gamma-phosphate location of ATP, close to the glycerol substrate. In addition to structural changes exhibited at the active site, the conformational stability of the activation loop is decreased, as reflected by an approximately 35% increase in B factors ('thermal factors') in a mutant enzyme displaying diminished activity, His232Glu. Correlating conformational changes to alteration of enzymatic activities in the mutant enzymes identifies distinct localized regions that can have profound effects on intramolecular signal transduction. Alterations in pairwise interactions across the dimer interface can communicate phosphorylation states over 25 A from the activation loop to the catalytic cleft, positioning Arg18 to form favorable interactions at the beta,gamma-bridging position with ATP. This would offset loss of the hydrogen bonds at the gamma-phosphate of ATP during phosphoryl transfer to glycerol, suggesting that appropriate alignment of the second substrate of glycerol kinase, the ATP molecule, may largely determine the rate of glycerol 3-phosphate production.« less

Redistribution Principle Approach for Evaluation of Seismic Active Earth Pressure Behind Retaining Wall

NASA Astrophysics Data System (ADS)

Maskar, A. D.; Madhekar, S. N.; Phatak, D. R.

2017-11-01

The knowledge of seismic active earth pressure behind the rigid retaining wall is very essential in the design of retaining wall in earthquake prone regions. Commonly used Mononobe-Okabe (MO) method considers pseudo-static approach. Recently there are many pseudo-dynamic methods used to evaluate the seismic earth pressure. However, available pseudo-static and pseudo-dynamic methods do not incorporate the effect of wall movement on the earth pressure distribution. Dubrova (Interaction between soils and structures, Rechnoi Transport, Moscow, 1963) was the first, who considered such effect and till date, it is used for cohesionless soil, without considering the effect of seismicity. In this paper, Dubrova's model based on redistribution principle, considering the seismic effect has been developed. It is further used to compute the distribution of seismic active earth pressure, in a more realistic manner, by considering the effect of wall movement on the earth pressure, as it is displacement based method. The effects of a wide range of parameters like soil friction angle (ϕ), wall friction angle (δ), horizontal and vertical seismic acceleration coefficients (kh and kv); on seismic active earth pressure (Kae) have been studied. Results are presented for comparison of pseudo-static and pseudo-dynamic methods, to highlight the realistic, non-linearity of seismic active earth pressure distribution. The current study results in the variation of Kae with kh in the same manner as that of MO method and Choudhury and Nimbalkar (Geotech Geol Eng 24(5):1103-1113, 2006) study. To increase in ϕ, there is a reduction in static as well as seismic earth pressure. Also, by keeping constant ϕ value, as kh increases from 0 to 0.3, earth pressure increases; whereas as δ increases, active earth pressure decreases. The seismic active earth pressure coefficient (Kae) obtained from the present study is approximately same as that obtained by previous researchers. Though seismic earth pressure obtained by pseudo-dynamic approach and seismic earth pressure obtained by redistribution principle have different background of formulation, the final earth pressure distribution is approximately same.

From neurons to circuits: linear estimation of local field potentials.

PubMed

Rasch, Malte; Logothetis, Nikos K; Kreiman, Gabriel

2009-11-04

Extracellular physiological recordings are typically separated into two frequency bands: local field potentials (LFPs) (a circuit property) and spiking multiunit activity (MUA). Recently, there has been increased interest in LFPs because of their correlation with functional magnetic resonance imaging blood oxygenation level-dependent measurements and the possibility of studying local processing and neuronal synchrony. To further understand the biophysical origin of LFPs, we asked whether it is possible to estimate their time course based on the spiking activity from the same electrode or nearby electrodes. We used "signal estimation theory" to show that a linear filter operation on the activity of one or a few neurons can explain a significant fraction of the LFP time course in the macaque monkey primary visual cortex. The linear filter used to estimate the LFPs had a stereotypical shape characterized by a sharp downstroke at negative time lags and a slower positive upstroke for positive time lags. The filter was similar across different neocortical regions and behavioral conditions, including spontaneous activity and visual stimulation. The estimations had a spatial resolution of approximately 1 mm and a temporal resolution of approximately 200 ms. By considering a causal filter, we observed a temporal asymmetry such that the positive time lags in the filter contributed more to the LFP estimation than the negative time lags. Additionally, we showed that spikes occurring within approximately 10 ms of spikes from nearby neurons yielded better estimation accuracies than nonsynchronous spikes. In summary, our results suggest that at least some circuit-level local properties of the field potentials can be predicted from the activity of one or a few neurons.

Transcriptional activation of the suppressor of cytokine signaling-3 (SOCS-3) gene via STAT3 is increased in F9 REX1 (ZFP-42) knockout teratocarcinoma stem cells relative to wild-type cells.

PubMed

Xu, Juliana; Sylvester, Renia; Tighe, Ann P; Chen, Siming; Gudas, Lorraine J

2008-03-14

Rex1 (Zfp42), first identified as a gene that is transcriptionally repressed by retinoic acid (RA), encodes a zinc finger transcription factor expressed at high levels in F9 teratocarcinoma stem cells, embryonic stem cells, and other stem cells. Loss of both alleles of Rex1 by homologous recombination alters the RA-induced differentiation of F9 cells, a model of pluripotent embryonic stem cells. We identified Suppressor of Cytokine Signaling-3 (SOCS-3) as a gene that exhibits greatly increased transcriptional activation in RA, cAMP, and theophylline (RACT)-treated F9 Rex1(-/-) cells (approximately 25-fold) as compared to wild-type (WT) cells ( approximately 2.5-fold). By promoter deletion, mutation, and transient transfection analyses, we have shown that this transcriptional increase is mediated by the STAT3 DNA-binding elements located between -99 to -60 in the SOCS-3 promoter. Overexpression of STAT3 dominant-negative mutants greatly diminishes this SOCS-3 transcriptional increase in F9 Rex1(-/-) cells. This increase in SOCS-3 transcription is associated with a four- to fivefold higher level of tyrosine-phosphorylated STAT3 in the RACT-treated F9 Rex1(-/-) cells as compared to WT. Dominant-negative Src tyrosine kinase, Jak2, and protein kinase A partially reduce the transcriptional activation of the SOCS 3 gene in RACT-treated F9 Rex1 null cells. In contrast, parathyroid hormone peptide enhances the effect of RA in F9 Rex1(-/-) cells, but not in F9 WT. Thus, Rex1, which is highly expressed in stem cells, inhibits signaling via the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, thereby modulating the differentiation of F9 cells.

Stated Uptake of Physical Activity Rewards Programmes Among Active and Insufficiently Active Full-Time Employees.

PubMed

Ozdemir, Semra; Bilger, Marcel; Finkelstein, Eric A

2017-10-01

Employers are increasingly relying on rewards programmes in an effort to promote greater levels of activity among employees; however, if enrolment in these programmes is dominated by active employees, then they are unlikely to be a good use of resources. This study uses a stated-preference survey to better understand who participates in rewards-based physical activity programmes, and to quantify stated uptake by active and insufficiently active employees. The survey was fielded to a national sample of 950 full-time employees in Singapore between 2012 and 2013. Participants were asked to choose between hypothetical rewards programmes that varied along key dimensions and whether or not they would join their preferred programme if given the opportunity. A mixed logit model was used to analyse the data and estimate predicted uptake for specific programmes. We then simulated employer payments based on predictions for the percentage of each type of employee likely to meet the activity goal. Stated uptake ranged from 31 to 67% of employees, depending on programme features. For each programme, approximately two-thirds of those likely to enrol were insufficiently active. Results showed that insufficiently active employees, who represent the majority, are attracted to rewards-based physical activity programmes, and at approximately the same rate as active employees, even when enrolment fees are required. This suggests that a programme with generous rewards and a modest enrolment fee may have strong employee support and be within the range of what employers may be willing to spend.

Lexical statistics of competition in L2 versus L1 listening

NASA Astrophysics Data System (ADS)

Cutler, Anne

2005-09-01

Spoken-word recognition involves multiple activation of alternative word candidates and competition between these alternatives. Phonemic confusions in L2 listening increase the number of potentially active words, thus slowing word recognition by adding competitors. This study used a 70,000-word English lexicon backed by frequency statistics from a 17,900,000-word corpus to assess the competition increase resulting from two representative phonemic confusions, one vocalic (ae/E) and one consonantal (r/l), in L2 versus L1 listening. The first analysis involved word embedding. Embedded words (cat in cattle, rib in ribbon) cause competition, which phonemic confusion can increase (cat in kettle, rib in liberty). The average increase in number of embedded words was 59.6 and 48.3 temporary ambiguity. Even when no embeddings are present, multiple alternatives are possible: para- can become parrot, paradise, etc., but also pallet, palace given /r/-/l/ confusion. Phoneme confusions (vowel or consonant) in first or second position in the word approximately doubled the number of activated candidates; confusions later in the word increased activation by on average 53 third, 42 confusions significantly increase competition for L2 compared with L1 listeners.

Establishing a before School Activity Program

ERIC Educational Resources Information Center

Mozen, Diana; Cradic, Sharon; Lehwald, Harry

2010-01-01

America is in the midst of an obesity epidemic. Obesity rates among adults have increased by more than 60% in the last 10 years to where approximately 25% of American adults are obese today. According to Dr. Duane Alexander, Director of the National Institute of Child Health and Human Development (NIH, 2003), the number of obese children is…

Urban ecosystems and the North American carbon cycle

Treesearch

D.E. Pataki; R.J. Alig; A.S. Fung; E. Golubiewski; C.A. Kennedy; E.G. McPherson; D.J. Nowak; R.V. Pouyat; P. Romero Lankao

2006-01-01

Approximately 75-80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in...

Vital Signs: Prevalence of Doctor-Diagnosed Arthritis and Arthritis-Attributable Activity Limitation - United States, 2013-2015.

PubMed

Barbour, Kamil E; Helmick, Charles G; Boring, Michael; Brady, Teresa J

2017-03-10

In the United States, doctor-diagnosed arthritis is a common and disabling chronic condition. Arthritis can lead to severe joint pain and poor physical function, and it can negatively affect quality of life. CDC analyzed 2013-2015 data from the National Health Interview Survey, an annual, nationally representative, in-person interview survey of the health status and behaviors of the noninstitutionalized civilian U.S. adult population, to update previous prevalence estimates of arthritis and arthritis-attributable activity limitations. On average, during 2013-2015, 54.4 million (22.7%) adults had doctor-diagnosed arthritis, and 23.7 million (43.5% of those with arthritis) had arthritis-attributable activity limitations (an age-adjusted increase of approximately 20% in the proportion of adults with arthritis reporting activity limitations since 2002 [p-trend <0.001]). Among adults with heart disease, diabetes, and obesity, the prevalences of doctor-diagnosed arthritis were 49.3%, 47.1%, and 30.6%, respectively; the prevalences of arthritis-attributable activity limitations among adults with these conditions and arthritis were 54.5% (heart disease), 54.0% (diabetes), and 49.0% (obesity). The prevalence of arthritis is high, particularly among adults with comorbid conditions, such as heart disease, diabetes, and obesity. Furthermore, the prevalence of arthritis-attributable activity limitations is high and increasing over time. Approximately half of adults with arthritis and heart disease, arthritis and diabetes, or arthritis and obesity are limited by their arthritis. Greater use of evidence-based physical activity and self-management education interventions can reduce pain and improve function and quality of life for adults with arthritis and also for adults with other chronic conditions who might be limited by their arthritis.

Vital Signs: Prevalence of Doctor-Diagnosed Arthritis and Arthritis-Attributable Activity Limitation — United States, 2013–2015

PubMed Central

Helmick, Charles G.; Boring, Michael; Brady, Teresa J.

2017-01-01

Background In the United States, doctor-diagnosed arthritis is a common and disabling chronic condition. Arthritis can lead to severe joint pain and poor physical function, and it can negatively affect quality of life. Methods CDC analyzed 2013–2015 data from the National Health Interview Survey, an annual, nationally representative, in-person interview survey of the health status and behaviors of the noninstitutionalized civilian U.S. adult population, to update previous prevalence estimates of arthritis and arthritis-attributable activity limitations. Results On average, during 2013–2015, 54.4 million (22.7%) adults had doctor-diagnosed arthritis, and 23.7 million (43.5% of those with arthritis) had arthritis-attributable activity limitations (an age-adjusted increase of approximately 20% in the proportion of adults with arthritis reporting activity limitations since 2002 [p-trend <0.001]). Among adults with heart disease, diabetes, and obesity, the prevalences of doctor-diagnosed arthritis were 49.3%, 47.1%, and 30.6%, respectively; the prevalences of arthritis-attributable activity limitations among adults with these conditions and arthritis were 54.5% (heart disease), 54.0% (diabetes), and 49.0% (obesity). Conclusions and Comments The prevalence of arthritis is high, particularly among adults with comorbid conditions, such as heart disease, diabetes, and obesity. Furthermore, the prevalence of arthritis-attributable activity limitations is high and increasing over time. Approximately half of adults with arthritis and heart disease, arthritis and diabetes, or arthritis and obesity are limited by their arthritis. Greater use of evidence-based physical activity and self-management education interventions can reduce pain and improve function and quality of life for adults with arthritis and also for adults with other chronic conditions who might be limited by their arthritis. PMID:28278145

Where they live, how they play: Neighborhood greenness and outdoor physical activity among preschoolers

PubMed Central

2011-01-01

Background Emerging empirical evidence suggests exposure to "green" environments may encourage higher levels of physical activity among children. Few studies, however, have explored this association exclusively in pre-school aged children in the United States. We examined whether residing in neighborhoods with higher levels of greenness was associated with higher levels of outdoor physical activity among preschoolers. In addition, we also explored whether outdoor playing behaviors (e.g., active vs. quiet) were influenced by levels of neighborhood greenness independent of demographic and parental support factors. Results Higher levels of neighborhood greenness as measured by the Normalized Difference Vegetation Index (NDVI) was associated with higher levels of outdoor playing time among preschool-aged children in our sample. Specifically, a one unit increase in neighborhood greenness increased a child's outdoor playing time by approximately 3 minutes. A dose-response relationship was observed between increasing levels of parental support for physical activity (e.g., time spent playing with children) and child outdoor physical activity (p < 0.01). Conclusions Consistent with previous studies, neighborhood greenness influences physical activity behavior. However, for preschoolers, parental involvement may be more critical for improving physical activity levels. PMID:22165919

Insulin-sensitizing effect of rosiglitazone (BRL-49653) by regulation of glucose transporters in muscle and fat of Zucker rats.

PubMed

Kramer, D; Shapiro, R; Adler, A; Bush, E; Rondinone, C M

2001-11-01

Thiazolidinediones (TZDs), a class of antidiabetic agents, are specific agonists of peroxisome proliferator activator receptor (PPARgamma). However, their mechanisms of action, and the in vivo target tissues that mediate insulin sensitization are not well understood. The aim of this study was to investigate the role of glucose transporters (GLUT-1 and GLUT-4) in the TZD insulin-sensitizer action. The effects of rosiglitazone treatment were studied using Zucker (fa/fa) rats after 7 days of oral dosing (3.6 mg/kg/d). Rosiglitazone lowered (approximate 80%) basal plasma insulin levels in obese rats and substantially corrected (approximately 50%) insulin resistance based upon results from hyperinsulinemic euglycemic clamp studies. GLUT-4 protein levels were reduced (approximately 75%) in adipose tissue of obese rats and treatment with rosiglitazone normalized them. Interestingly, GLUT-1 protein content was increased in adipose tissue ( thick approximate 150%) and skeletal muscle (approximately 50%) of obese rats and treatment with rosiglitazone increased it even more by 5.5-fold in fat and by 2.5-fold in muscle. Consistent with these results, basal (GLUT-1-mediated) transport rate of 3-O-methyl-D-glucose into isolated epitrochlearis muscle was elevated in response to rosiglitazone. Incubation of fully differentiated 3T3-L1 adipocytes with the drug for 7 days increased the levels of GLUT-1 protein, but did not affect GLUT-4 levels. In conclusion, rosiglitazone may improve insulin resistance in vivo by normalizing GLUT-4 protein content in adipose tissue and increasing GLUT-1 in skeletal muscle and fat. While the drug has a direct effect on GLUT-1 protein expression in vitro without a direct effect on GLUT-4 suggests that direct and indirect effects of rosiglitazone on glucose transporters may have an important role in improving insulin resistance in vivo. Copyright 2001 by W.B. Saunders Company

Isolation and characterization of a cDNA clone coding for a glutathione S-transferase class delta enzyme from the biting midge Culicoides variipennis sonorensis Wirth and Jones.

PubMed

Abdallah, M A; Pollenz, R S; Droog, F N; Nunamaker, R A; Tabachnick, W J; Murphy, K E

2000-12-01

Culicoides variipennis sonorensis is the primary vector of bluetongue viruses in North America. Glutathione S-transferases (GSTs) are enzymes that catalyze nucleophilic substitutions, converting reactive lipophilic molecules into soluble conjugates. Increased GST activity is associated with development of insecticide resistance. Described here is the isolation of the first cDNA encoding a C. variipennis GST. The clone consists of 720 translated bases encoding a protein with a M(r) of approximately 24,800 composed of 219 amino acids. The deduced amino acid sequence is similar (64%-74%) to class Delta (previously named Theta) GSTs from the dipteran genera Musca, Drosophila, Lucilia and Anopheles. The cDNA was subcloned into pET-11b, expressed in Epicurian coli BL21 (DE3) and has a specific activity of approximately 28,000 units/mg for the substrate 1-chloro-2,4-dinitrobenzene.

Evaluating the features of the brain waves to quantify ADHD improvement by neurofeedback.

PubMed

Dehghanpour, Peyman; Einalou, Zahra

2017-10-23

Attention-deficit/hyperactivity disorder (ADHD), as one of the most common neurological disorders in children and adolescents, is characterized by decentralization, slow learning, distraction and hyperactivity. Studies have shown that in addition to medication, neurofeedback training can also be used to partially control the brain activity of these patients. In this study, using the brain signals processing before and after the treatment in 10 children treated by neurofeedback, the changes were evaluated by non-parametric statistical analysis and impact of neurofeedback on brain frequency bands was investigated. Finally, the results were compared with the protocols introduced in this paper and before researches. The results of Kruskal-Wallis test showed an approximately significant increase in the relative power of gamma and an approximately significant reduction in the ratio of relative power of alpha/beta. It represents the emotional response, elicited by the successful learning and diminished ratio of slow learning to active learning respectively.

Muscle architecture and fibre characteristics of rat gastrocnemius and semimembranosus muscles during isometric contractions.

PubMed

Huijing, P A; van Lookeren Campagne, A A; Koper, J F

1989-01-01

Rat gastrocnemius medialis (GM) and semimembranosus (SM) muscles have a very different morphology. GM is a very pennate muscle, combining relatively short muscle fibre length with sizable fibre angles and long muscle and aponeurosis lengths. SM is a more parallel-fibred muscle, combining a relatively long fibre length with a small fibre angle and short aponeurosis length. The mechanisms of fibre shortening as well as angle increase are operational in GM as well as SM. However, as a consequence of isometric contraction, changes of fibre length and angle are greater for GM than for SM at any relative muscle length. These differences are particularly notable at short muscle lengths: at 80% of optimum muscle length, fibre length changes of approximately 30% are coupled to fibre angle changes of 15 degrees in GM, while for SM these changes are 4% and 0.6 degrees, respectively. A considerable difference was found for normalized active slack muscle length (GM approximately 80 and SM approximately 45%). This is explained by differences of degree of pennation as well as factors related to differences found for estimated fibre length-force characteristics. Estimated normalized active fibre slack length was considerably smaller for SM than for GM (approximately 40 and 60%, respectively). The most likely explanation of these findings are differences of distribution of optimum fibre lengths, possibly in combination with differences of myofilament lengths and/or fibre length distributions.

Enhanced HTS hit selection via a local hit rate analysis.

PubMed

Posner, Bruce A; Xi, Hualin; Mills, James E J

2009-10-01

The postprocessing of high-throughput screening (HTS) results is complicated by the occurrence of false positives (inactive compounds misidentified as active by the primary screen) and false negatives (active compounds misidentified as inactive by the primary screen). An activity cutoff is frequently used to select "active" compounds from HTS data; however, this approach is insensitive to both false positives and false negatives. An alternative method that can minimize the occurrence of these artifacts will increase the efficiency of hit selection and therefore lead discovery. In this work, rather than merely using the activity of a given compound, we look at the presence and absence of activity among all compounds in its "chemical space neighborhood" to give a degree of confidence in its activity. We demonstrate that this local hit rate (LHR) analysis method outperforms hit selection based on ranking by primary screen activity values across ten diverse high throughput screens, spanning both cell-based and biochemical assay formats of varying biology and robustness. On average, the local hit rate analysis method was approximately 2.3-fold and approximately 1.3-fold more effective in identifying active compounds and active chemical series, respectively, than selection based on primary activity alone. Moreover, when applied to finding false negatives, this method was 2.3-fold better than ranking by primary activity alone. In most cases, novel hit series were identified that would have otherwise been missed. Additional uses of and observations regarding this HTS analysis approach are also discussed.

Long-term Trends in Interplanetary Magnetic Field Strength and Solar Wind Structure during the 20th Century

NASA Technical Reports Server (NTRS)

Richardson, I. G.; Cliver, E. W.; Cane, H. V.; White, Nicholas E. (Technical Monitor)

2002-01-01

Lockwood et al have recently reported an approximately 40% increase in the radial component of the interplanetary magnetic field (IMF) at Earth between 1964 and 1996. We argue that this increase does not constitute a secular trend but is largely the consequence of lower than average fields during solar cycle 20 (1964-1976) in comparison with surrounding cycles. For times after 1976 the average IMF strength has actually decreased slightly. Examination of the cosmic ray intensity, an indirect measure of the IMF strength, over the last five solar cycles (19-23) also indicates that cycle averages of the IMF strength have been relatively constant since approximately 1954. We also consider the origin of the well-documented increase in the geomagnetic alphaalpha index that occurred primarily during the first half of the twentieth century. We surmise that the coronal mass ejection (CME) rate for recent solar cycles was approximately twice as high as that for solar cycles 100 years ago. However, this change in the CME rate and the accompanying increase in 27-day recurrent storm activity reported by others are unable to account completely for the increase in alphaalpha. Rather, the CMEs and recurrent high-speed streams at the beginning of the twentieth century must have been embedded in a background of slow solar wind that was less geoeffective (having, for example, lower IMF strength and/or flow speed) than its modern counterpart.

A Phase-Locked Loop Epilepsy Network Emulator.

PubMed

Watson, P D; Horecka, K M; Cohen, N J; Ratnam, R

2016-10-15

Most seizure forecasting employs statistical learning techniques that lack a representation of the network interactions that give rise to seizures. We present an epilepsy network emulator (ENE) that uses a network of interconnected phase-locked loops (PLLs) to model synchronous, circuit-level oscillations between electrocorticography (ECoG) electrodes. Using ECoG data from a canine-epilepsy model (Davis et al. 2011) and a physiological entropy measure (approximate entropy or ApEn, Pincus 1995), we demonstrate the entropy of the emulator phases increases dramatically during ictal periods across all ECoG recording sites and across all animals in the sample. Further, this increase precedes the observable voltage spikes that characterize seizure activity in the ECoG data. These results suggest that the ENE is sensitive to phase-domain information in the neural circuits measured by ECoG and that an increase in the entropy of this measure coincides with increasing likelihood of seizure activity. Understanding this unpredictable phase-domain electrical activity present in ECoG recordings may provide a target for seizure detection and feedback control.

Norepinephrine transporter blocker atomoxetine increases salivary alpha amylase.

PubMed

Warren, Christopher M; van den Brink, Ruud L; Nieuwenhuis, Sander; Bosch, Jos A

2017-04-01

It has been suggested that central norepinephrine (NE) activity may be inferred from increases in salivary alpha-amylase (SAA), but data in favor of this proposition are limited. We administered 40mg of atomoxetine, a selective NE transporter blocker that increases central NE levels, to 24 healthy adult participants in a double-blind, placebo-controlled cross-over design. Atomoxetine administration significantly increased SAA secretion and concentrations at 75-180min after treatment (more than doubling baseline levels). Consistent with evidence that elevation in central NE is a co-determinant of hypothalamic-pituitary-adrenal axis activity, salivary cortisol also approximately doubled at the same time points. Moreover, changes in salivary cortisol positively correlated with SAA (0.44

The dose-response effects of aerobic exercise on musculoskeletal injury: a post hoc analysis of a randomized trial.

PubMed

Brown, Justin C; Schmitz, Kathryn H

2017-01-01

In a post hoc analysis, we quantified the risk of musculoskeletal injury (MSI) associated with different volumes of aerobic exercise in a randomized trial. Premenopausal women (n = 119) were randomized to one of three groups: low-dose aerobic exercise (150 min·per week), high-dose aerobic exercise (300 min·per week) or control (usual activity) for 5 months. Compared to the control group, the risk of reporting an acute MSI increased with higher volumes of aerobic exercise, with a similar pattern observed for recurrent MSI. The risk of reporting an MSI severe enough to impair activities of daily living did not increase with higher volumes of aerobic exercise. Approximately half of MSI were causally attributed to aerobic exercise. The risk of experiencing an acute or recurrent MSI increases with higher volumes of aerobic exercise; however, the risk of experiencing an MSI severe enough to impair activities of daily living does not increase with higher volumes of aerobic exercise.

Ice-shelf collapse from subsurface warming as a trigger for Heinrich events

PubMed Central

Marcott, Shaun A.; Clark, Peter U.; Padman, Laurie; Klinkhammer, Gary P.; Springer, Scott R.; Liu, Zhengyu; Otto-Bliesner, Bette L.; Carlson, Anders E.; Ungerer, Andy; Padman, June; He, Feng; Cheng, Jun; Schmittner, Andreas

2011-01-01

Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event. PMID:21808034

A mechanism for inducing climatic variations through ozone destruction: Screening of galactic cosmic rays by solar and terrestrial magnetic fields

NASA Technical Reports Server (NTRS)

Chamberlain, J. W.

1976-01-01

A perturbation analysis, allowing for temperature and opacity feedbacks, is developed to calculate depletions in the O3 abundance and reductions of stratospheric solar heating that result from increases in NOx concentration. A pair of perturbation coefficients give the reduction in O3 and temperature through the stratosphere for a specified NOx increase. This type of analysis illustrates the tendency for various levels to self-heal when a perturbation occurs. Physical arguments indicate that the expected sign of the climatic effect is correct, with colder surface temperatures produced by reduced magnetic shielding. In addition, four qualitative reasons are suggested for thinking that significant ozone reductions by cosmic ray influxes will lead to an increased terrestrial albedo from stratospheric condensation. In this view, long-term (approximately 10,000 years) climatic changes have resulted from secular geomagnetic variations while shorter (approximately 100 years) excursions are related to changes in solar activity.

Using nonlinear ac electrokinetics vortex flow to enhance catalytic activities of sol-gel encapsulated trypsin in microfluidic devices.

PubMed

Wang, Shau-Chun; Chen, Hsiao-Ping; Lai, Yi-Wen; Chau, Lai-Kwan; Chuang, Yu-Chun; Chen, Yi-Jie

2007-09-04

A novel microstirring strategy is applied to accelerate the digestion rate of the substrate N(alpha)-benzoyl-L-arginine-4-nitroanilide (L-BAPA) catalyzed by sol-gel encapsulated trypsin. We use an ac nonlinear electrokinetic vortex flow to stir the solution in a microfluidic reaction chamber to reduce the diffusion length between the immobilized enzyme and substrate in the solution. High-intensity nonlinear electroosmotic microvortices, with angular speeds in excess of 1 cms, are generated around a small ( approximately 1.2 mm) conductive ion exchange granule when ac electric fields (133 Vcm) are applied across a miniature chamber smaller than 10 mul. Coupling between these microvortices and the on-and-off electrophoretic motion of the granule in low frequency (0.1 Hz) ac fields produces chaotic stream lines to stir substrate molecules sufficiently. We demonstrate that, within a 5-min digestion period, the catalytic reaction rate of immobilized trypsin increases almost 30-fold with adequate reproducibility (15%) due to sufficient stirring action through the introduction of the nonlinear electrokinetic vortices. In contrast, low-frequency ac electroosmotic flow without the granule, provides limited stirring action and increases the reaction rate approximately ninefold with barely acceptable reproducibility (30%). Dye molecules are used to characterize the increases in solute diffusivity in the reaction reservoir in which sol-gel particles are placed, with and without the presence of granule, and compared with the static case. The solute diffusivity enhancement data show respective increases of approximately 30 and approximately 8 times, with and without the presence of granule. These numbers are consistent with the ratios of the enhanced reaction rate.

Dose relations between goal setting, theory-based correlates of goal setting and increases in physical activity during a workplace trial.

PubMed

Dishman, Rod K; Vandenberg, Robert J; Motl, Robert W; Wilson, Mark G; DeJoy, David M

2010-08-01

The effectiveness of an intervention depends on its dose and on moderators of dose, which usually are not studied. The purpose of the study is to determine whether goal setting and theory-based moderators of goal setting had dose relations with increases in goal-related physical activity during a successful workplace intervention. A group-randomized 12-week intervention that included personal goal setting was implemented in fall 2005, with a multiracial/ethnic sample of employees at 16 geographically diverse worksites. Here, we examined dose-related variables in the cohort of participants (N = 664) from the 8 worksites randomized to the intervention. Participants in the intervention exceeded 9000 daily pedometer steps and 300 weekly minutes of moderate-to-vigorous physical activity (MVPA) during the last 6 weeks of the study, which approximated or exceeded current public health guidelines. Linear growth modeling indicated that participants who set higher goals and sustained higher levels of self-efficacy, commitment and intention about attaining their goals had greater increases in pedometer steps and MVPA. The relation between change in participants' satisfaction with current physical activity and increases in physical activity was mediated by increases in self-set goals. The results show a dose relation of increased physical activity with changes in goal setting, satisfaction, self-efficacy, commitment and intention, consistent with goal-setting theory.

Biodegradation of 2,4,6-tribromophenol during transport in fractured chalk.

PubMed

Arnon, Shai; Adar, Eilon; Ronen, Zeev; Nejidat, Ali; Yakirevich, Alexander; Nativ, Ronit

2005-02-01

The effect of physicochemical conditions (residence time, oxygen concentrations, and chalk characteristics) on the biodegradation of 2,4,6-tribromophenol (TBP) during transport was investigated in low-permeability fractured-chalk cores. Long-term (approximately 600 d) biodegradation experiments were conducted in two cores (approximately 21 cm diameter, 31 and 44 cm long, respectively), intersected by a natural fracture. TBP was used as a model contaminant and as the sole carbon source for aerobic microbial activity. Bacterial isolates were recovered and identified by both Biolog identification kit and 16S rDNA sequences from batch enrichment cultures. One of the strains, with 98% similarity (based on the 16S rDNA data) to Achromobacter xylosoxidans, was shown to have the ability to degrade TBP in the presence of chalk. The decrease in TBP concentration along the fracture due to biodegradation was not affected by reducing the residence time from 49 to 8 min. In contrast, adding oxygen to the water at the inlet and increasing the flow rates improved TBP removal. Although the matrix pore-size distribution limits microbial activity to the fracture void, the chalk appears to provide an excellent environment for biodegradation activity. Approximately 90% of TBP removal occurred within 10 cm of the TBP source, indicating that in-situ bioremediation can be used to remove organic contaminants in low-permeability fractured rocks if nutrient-delivery pathways within the aquifer are secured.

Activation of pregnane X receptor and induction of MDR1 by dietary phytochemicals.

PubMed

Satsu, Hideo; Hiura, Yuto; Mochizuki, Keiichi; Hamada, Mika; Shimizu, Makoto

2008-07-09

The pregnane X receptor (PXR) is understood to be the key regulator for gene expression of such drug-metabolizing enzymes and transporters as multidrug-resistant protein 1 (MDR1) and the cytochrome P450 (CYP) family. We examined the effect of dietary phytochemicals on the PXR-dependent transcriptional activity in human intestinal LS180 cells by using a reporter assay. Among approximately 40 kinds of phytochemicals, tangeretin and ginkgolides A and B markedly induced the PXR-dependent transcriptional activity and also the activity of the human MDR1 promoter. The expression levels of MDR1 mRNA as well as of CYP3A4 mRNA, another gene regulated by PXR, were significantly increased by these phytochemicals. Furthermore, an increase was observed of the MDR1 protein and its functional activity by tangeretin and by ginkgolides A and B. These findings strongly suggest that tangeretin and ginkgolides A and B activated PXR, thereby regulating detoxification enzymes and transporters in the intestines.

Factors related to physical activity adherence in women: review and suggestions for future research.

PubMed

White, Jennifer L; Ransdell, Lynda B; Vener, Jamie; Flohr, Judith A

2005-01-01

Approximately 50 percent of individuals who start an exercise program withdraw within 6 months. Thus, many individuals withdraw before health benefits have been realized. This is a disconcerting statistic considering the well known benefits of physical activity for decreasing risk of hypokinetic diseases and improving quality of life. The literature has suggested a plethora of factors to increase the number of individuals who initiate a physical activity program. However, little is known about the factors that keep women exercising-otherwise known as exercise adherence. The purpose of this paper is to: (a) systematically review the quantitative literature to discern the major factors contributing to adherence to physical activity in women and men and make recommendations for specific gender-based considerations that are important when designing PA interventions for women, and (b) suggest areas of future research related to increasing adherence to physical activity in women. Key factors reviewed in this paper may be useful in developing efficacious physical activity programs for women.

Production, purification, and properties of a lipase from a bacterium (Pseudomonas aeruginosa YS-7) capable of growing in water-restricted environments.

PubMed Central

Shabtai, Y; Daya-Mishne, N

1992-01-01

An extracellular lipase from the low-water-tolerant bacterium P. aeruginosa YS-7 was produced, purified, and characterized with respect to its functional properties in aqueous solutions and organic solvents. The enzyme was partially released from the cells during fermentation in defined medium with 5% (wt/vol) soybean oil. Approximately one-half of the total culture activity remained in solution after removal of cells. More than 95% of the activity was found in culture supernatant after mild detergent treatment (10 mM sodium deoxycholate) or after shifting the carbon source during the fermentation from triglyceride to a free fatty acid. The enzyme was recovered from an acetone precipitate of the whole culture and purified by hydrophobic interaction chromatography, yielding a preparation having a specific activity of about 1,300 mumol of fatty acid mg-1 h-1. The lipase (molecular size, approximately 40 kDa) hydrolyzes a variety of fatty acid esters and has an optimum pH of about 7. The enzyme retained its full activity at 20 to 55 degrees C, even after prolonged exposure (more than 30 days) to different concentrations of water-miscible organic solvents such as alcohols, glycols, pyridine, acetonitrile, dimethyl formamide, and dimethyl sulfoxide. The hydrolysis of 4-nitrophenyl laurate ester and of triglyceride emulsified in water was slightly accelerated with increasing concentrations of alcohols and glycols up to about 20% but was abolished with a further increase in alcohol concentration or in the presence of acetonitrile. In contrast, the rate of hydrolysis of these substrates in concentrated solutions of dimethyl formamide or dimethyl sulfoxide was markedly increased, by more than twofold and more than fivefold, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:1539972

'Her shape' intervention programme for obese women with high breast adiposity.

PubMed

Juliana, Norsham; Shahar, Suzana; Sahar, Mohd Azmani; Ghazali, Ahmad Rohi; Manaf, Zahara Abdul; Noah, Rahim Md

2017-03-01

Nutrition and physical activity interventions is beneficial in reversing obesity. However far too little attention has been paid to the effect of these interventions on breast tissues. Thus, the aim of this study was to explore the effect of a home-based dietary and physical activity intervention (the Her Shape Program) on metabolic parameters, blood biomarkers and adiposity at the breast. A randomized controlled study was conducted on obese women with high breast adiposity (<0.1 Sm-1), aged 40-60 years in Klang Valley, Malaysia. Subjects were assigned to intervention (n=16) and control group (n=15). Intervention group received a home based health education package with close monitoring weekly, personal diet consultation and physical training in group. Assessment was ascertained at three time points; baseline, weeks 8 and 16. Outcome measures were the energy intake, physical activity, body composition, blood tests, blood biomarkers and electrical impedance tomography (EIT) quantitative values. Analyses were done using 2-way repeated measures ANOVA. All subjects completed the program without any drop-out. The HSI group had 100% compliance towards the intervention program; their energy intake was reduced for approximately 35% and their activity score was increased for approximately 11%. A significant interaction effect was found in body weight, body mass index (BMI), total cholesterol/HDL, vitamin C intake and matrix metallopeptidase 9 (MMP-9) (p<0.05). Interestingly, their EIT extremum values were also significantly increased indicating a reduction of breast adiposity. The intervention program was successful in improving body composition, physical activities, MMP9 and breast adipose tissue composition.

Long-term Increases in Flower Production by Growth Forms in Response to Anthropogenic Change in a Tropical Forest

NASA Astrophysics Data System (ADS)

Pau, S.; Wright, S. J.

2016-12-01

There is mounting evidence that anthropogenic global change is altering the ecology of tropical forests. A limited number of studies have focused on long-term trends in tropical reproductive activity, yet differences in reproductive activity should have consequences for demography and ultimately forest carbon, water, and energy balance. Here we analyze a 28-year record of tropical flower production in response to anthropogenic climate change. We show that a multi-decadal increase in flower production is most strongly driven by rising atmospheric CO2, which had approximately 8x the effect of the Multivariate ENSO Index and approximately 13x the effect of rainfall or solar radiation. Interannual peaks in flower production were associated with greater solar radiation and low rainfall during El Niño years. Observed changes in solar radiation explained flower production better than rainfall (models including solar radiation accounted for 94% of cumulative AICc weight compared to 87% for rainfall). All growth forms (lianas, canopy trees, midstory trees, and shrubs) produced more flowers with increasing CO2 except for understory treelets. The increase in flower production was matched by a lengthening of flowering duration for canopy trees and midstory trees; duration was also longer for understory treelets. Given that anthropogenic CO2 emissions will continue to climb over the next century, the long-term increase in flower production may persist unless offset by increasing cloudiness in the tropics, or until rising CO2 and/or warming temperatures associated with the greenhouse effect pass critical thresholds for plant reproduction.

Geomagnetically Induced Currents Around the World During the 17 March 2015 Storm

NASA Technical Reports Server (NTRS)

Carter, B. A.; Yizengaw, E.; Pradipta, R.; Weygand, J. M.; Piersanti, M.; Pulkkinen, Antti Aleksi; Moldwin, M. B.; Norman, R.; Zhang, K.

2016-01-01

Geomagnetically induced currents (GICs) represent a significant space weather issue for power grid and pipeline infrastructure, particularly during severe geomagnetic storms. In this study, magnetometer data collected from around the world are analyzed to investigate the GICs caused by the 2015 St. Patricks Day storm. While significant GIC activity in the high-latitude regions due to storm time substorm activity is shown for this event, enhanced GIC activity was also measured at two equatorial stations in the American and Southeast Asian sectors. This equatorial GIC activity is closely examined, and it is shown that it is present both during the arrival of the interplanetary shock at the storm sudden commencement (SSC) in Southeast Asia and during the main phase of the storm approximately 10 h later in South America. The SSC caused magnetic field variations at the equator in Southeast Asia that were twice the magnitude of those observed only a few degrees to the north, strongly indicating that the equatorial electrojet (EEJ) played a significant role. The large equatorial magnetic field variations measured in South America are also examined, and the coincident solar wind data are used to investigate the causes of the sudden changes in the EEJ approximately 10 h into the storm. From this analysis it is concluded that sudden magnetopause current increases due to increases in the solarwind dynamic pressure, and the sudden changes in the resultant magnetospheric and ionospheric current systems, are the primary drivers of equatorial GICs.

Heterogeneous catalytic ozonation of dibutyl phthalate in aqueous solution in the presence of iron-loaded activated carbon.

PubMed

Huang, Yuanxing; Cui, Chenchen; Zhang, Daofang; Li, Liang; Pan, Ding

2015-01-01

Iron-loaded activated carbon was prepared and used as catalyst in heterogeneous catalytic ozonation of dibutyl phthalate (DBP). The catalytic activity of iron-loaded activated carbon was investigated under various conditions and the mechanisms of DBP removal were deduced. Characterization of catalyst indicated that the iron loaded on activated carbon was mainly in the form of goethite, which reduced its surface area, pore volume and pore diameter. The presence of metals on activated carbon positively contributed to its catalytic activity in ozonation of DBP. Iron loading content of 15% and initial water pH of 8 achieved highest DBP removal among all the tried conditions. Catalyst dosage of 10 mg L(-1) led to approximately 25% of increase in DBP (initial concentration 2 mg L(-1)) removal in 60 min as compared with ozone alone, and when catalyst dosage increased to 100 mg L(-1), the DBP removal was further improved by 46%. Based on a comparison of reaction rates for direct and indirect transformation of DBP, the increased removal of DBP in this study likely occurred via transformation of ozone into hydroxyl radicals on the catalyst surface. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of a faculty development program aimed at increasing residents' active learning in lectures.

PubMed

Desselle, Bonnie C; English, Robin; Hescock, George; Hauser, Andrea; Roy, Melissa; Yang, Tong; Chauvin, Sheila W

2012-12-01

Active engagement in the learning process is important to enhance learners' knowledge acquisition and retention and the development of their thinking skills. This study evaluated whether a 1-hour faculty development workshop increased the use of active teaching strategies and enhanced residents' active learning and thinking. Faculty teaching in a pediatrics residency participated in a 1-hour workshop (intervention) approximately 1 month before a scheduled lecture. Participants' responses to a preworkshop/postworkshop questionnaire targeted self-efficacy (confidence) for facilitating active learning and thinking and providing feedback about workshop quality. Trained observers assessed each lecture (3-month baseline phase and 3-month intervention phase) using an 8-item scale for use of active learning strategies and a 7-item scale for residents' engagement in active learning. Observers also assessed lecturer-resident interactions and the extent to which residents were asked to justify their answers. Responses to the workshop questionnaire (n  =  32/34; 94%) demonstrated effectiveness and increased confidence. Faculty in the intervention phase demonstrated increased use of interactive teaching strategies for 6 items, with 5 reaching statistical significance (P ≤ .01). Residents' active learning behaviors in lectures were higher in the intervention arm for all 7 items, with 5 reaching statistical significance. Faculty in the intervention group demonstrated increased use of higher-order questioning (P  =  .02) and solicited justifications for answers (P  =  .01). A 1-hour faculty development program increased faculty use of active learning strategies and residents' engagement in active learning during resident core curriculum lectures.

Diffusion and Stability of Hydrogen in Mg-Doped GaN: A Density Functional Study

NASA Astrophysics Data System (ADS)

Park, Ji-Sang; Chang, Kee Joo

2012-06-01

Using hybrid functional calculations, we study the diffusion and thermal stability of hydrogen in Mg-doped GaN. Compared with the generalized gradient approximation, we obtain a higher activation barrier for dissociating a Mg-H complex, which is attributed to the increase in the binding energy of Mg-H. Kinetic Monte Carlo simulations yield the annealing temperature of around 800 °C for activating Mg acceptors, close to the measured values. The results provide an insight to understanding the annealing effect such that the annealing temperature generally increases with the Mg-H concentration, and the retrapping of H is partly responsible for the low doping efficiencies at high Mg concentrations.

Case study II: application of the divalent cation bridging theory to improve biofloc properties and industrial activated sludge system performance-using alternatives to sodium-based chemicals.

PubMed

Higgins, Matthew J; Sobeck, David C; Owens, Steven J; Szabo, Lynn M

2004-01-01

The objective of this study was to investigate the application of the divalent cation bridging theory (DCBT) as a tool in the chemical selection process at an activated sludge plant to improve settling, dewatering, and effluent quality. According to the DCBT, to achieve improvements, the goal of chemical selection should be to reduce the ratio of monovalent-to-divalent (M/D) cations. A study was conducted to determine the effect of using magnesium hydroxide [Mg(OH)2] as an alternative to sodium hydroxide (NaOH) at a full-scale industrial wastewater treatment plant. Floc properties and treatment plant performance were measured for approximately one year during two periods of NaOH addition and Mg(OH)2 addition. A cost analysis of plant operation during NaOH and Mg(OH)2 use was also performed. During NaOH addition, the M/D ratio was 48, while, during Mg(OH)2 addition, this ratio was reduced to an average of approximately 0.1. During the Mg(OH)2 addition period, the sludge volume index, effluent total suspended solids, and effluent chemical oxygen demand were reduced by approximately 63, 31, and 50%, respectively, compared to the NaOH addition period. The alum and polymer dose used for clarification was reduced by approximately 50 and 60%, respectively, during Mg(OH)2 addition. The dewatering properties of the activated sludge improved dewatering as measured by decreased capillary suction time and specific resistance to filtration (SRF), along with an increase in cake solids from the SRF test. This corresponded to a reduction in the volume of solids thickened by centrifuges at the treatment plant, which reduced the disposal costs of solids. Considering the costs for chemicals and solids disposal, the annual cost of using Mg(OH)2 was approximately 30,000 dollars to 115,000 dollars less than using NaOH, depending on the pricing of NaOH. The results of this study confirm that the DCBT is a useful tool for assessing chemical-addition strategies and their potential effect on activated sludge performance.

Endogenous and exogenous ice-nucleating agents constrain supercooling in the hatchling painted turtle.

PubMed

Costanzo, Jon P; Baker, Patrick J; Dinkelacker, Stephen A; Lee, Richard E

2003-02-01

Hatchlings of the painted turtle (Chrysemys picta) commonly hibernate in their shallow, natal nests. Survival at temperatures below the limit of freeze tolerance (approximately -4 degrees C) apparently depends on their ability to remain supercooled, and, whereas previous studies have reported that supercooling capacity improves markedly with cold acclimation, the mechanistic basis for this change is incompletely understood. We report that the crystallization temperature (T(c)) of recently hatched (summer) turtles acclimated to 22 degrees C and reared on a substratum of vermiculite or nesting soil was approximately 5 degrees C higher than the T(c) determined for turtles acclimated to 4 degrees C and tested in winter. This increase in supercooling capacity coincided with elimination of substratum (and, in fewer cases, eggshell) that the hatchlings had ingested; however, this association was not necessarily causal because turtles reared on a paper-covered substratum did not ingest exogenous matter but nevertheless showed a similar increase in supercooling capacity. Our results for turtles reared on paper revealed that seasonal development of supercooling capacity fundamentally requires elimination of ice-nucleating agents (INA) of endogenous origin: summer turtles, but not winter turtles, produced feces (perhaps derived from residual yolk) that expressed ice-nucleating activity. Ingestion of vermiculite or eggshell, which had modest ice-nucleating activity, had no effect on the T(c), whereas ingestion of nesting soil, which contained two classes of potent INA, markedly reduced the supercooling capacity of summer turtles. This effect persisted long after the turtles had purged their guts of soil particles, because the T(c) of winter turtles reared on nesting soil (mean +/- S.E.M.=-11.6+/-1.4 degrees C) was approximately 6 degrees C higher than the T(c) of winter turtles reared on vermiculite or paper. Experiments in which winter turtles were fed INA commonly found in nesting soil showed that water-soluble, organic agents can remain fully active for at least one month. Such INA may account for the limited supercooling capacity (T(c) approximately -7.5 degrees C) we found in turtles overwintering in natural nests and may therefore pose a formidable challenge to the winter survival of hatchling C. picta.

Innovation to motivation--pilot study of a mobile phone intervention to increase physical activity among sedentary women.

PubMed

Fukuoka, Yoshimi; Vittinghoff, Eric; Jong, So Son; Haskell, William

2010-01-01

This uncontrolled pilot study assessed changes in pedometer-measured step counts and self-reported physical activity during a 3-week mobile phone-based intervention. We also explored whether age, BMI, and psychosocial factors were associated with changes in step counts. Forty-one sedentary adult women in San Francisco, California were asked to report their pedometer steps using a study-supplied mobile phone from June to September 2008. In the second and third weeks, daily prompts delivered by the mobile phone encouraged participants to increase steps by 20% from the previous week. Mean age was 48 years. Average daily total steps increased by approximately 800 or 15% over three weeks (p<0.001). Lower BMI, no antidepressant use, and lower self-reported health status were associated with higher step counts at baseline. Improvements in self-reported will-power were associated with increases in step counts (p<0.001). Neither age (p=0.55) nor BMI (p=0.13) was significantly associated with changes in activity over the 3 weeks. The intervention appeared to motivate sedentary women to increase their physical activity. A randomized controlled clinical trial is warranted and feasible. Copyright © 2010 Elsevier Inc. All rights reserved.

Characterization of the early pulmonary inflammatory response associated with PTFE fume exposure

NASA Technical Reports Server (NTRS)

Johnston, C. J.; Finkelstein, J. N.; Gelein, R.; Baggs, R.; Oberdorster, G.; Clarkson, T. W. (Principal Investigator)

1996-01-01

Heating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.

Tall fescue seed extraction and partial purification of ergot alkaloids

PubMed Central

Ji, Huihua; Fannin, F.; Klotz, J.; Bush, Lowell

2014-01-01

Many substances in the tall fescue/endophyte association (Schedonorus arundinaceus/Epichloë coenophiala) have biological activity. Of these compounds only the ergot alkaloids are known to have significant mammalian toxicity and the predominant ergot alkaloids are ergovaline and ergovalinine. Because synthetically produced ergovaline is difficult to obtain, we developed a seed extraction and partial purification protocol for ergovaline/ergovalinine that provided a biologically active product. Tall fescue seed was ground and packed into several different sized columns for liquid extraction. Smaller particle size and increased extraction time increased efficiency of extraction. Our largest column was a 114 × 52 × 61 cm (W × L × D) stainless steel tub. Approximately 150 kg of seed could be extracted in this tub. The extraction was done with 80% ethanol. When the solvent front migrated to bottom of the column, flow was stopped and seed was allowed to steep for at least 48 h. Light was excluded from the solvent from the beginning of this step to the end of the purification process. Following elution, ethanol was removed from the eluate by evaporation at room temperature and the resulting syrup was freeze-dried. About 80% recovery of alkaloids was achieved with 18-fold increase in concentration of ergovaline. Initial purification of the dried product was accomplished by extracting with hexane/water (6:1, v/v). The aqueous fraction was extracted with chloroform, the aqueous layer discarded, after which the chloroform was removed with a resulting 20-fold increase of ergovaline. About 65% of the ergovaline was recovered from the chloroform residue for an overall recovery of 50%. The resultant partially purified ergovaline had biological activities in in vivo and in vitro bovine bioassays that approximate that of synthetic ergovaline. PMID:25566528

Tall fescue seed extraction and partial purification of ergot alkaloids

NASA Astrophysics Data System (ADS)

Bush, Lowell

2014-12-01

Many substances in the tall fescue/endophyte association (Schedonorus arundinaceus/Epichloë coenophiala) have biological activity. Of these compounds only the ergot alkaloids are known to have significant mammalian toxicity and the predominant ergot alkaloids are ergovaline and ergovalinine. Because synthetically produced ergovaline is difficult to obtain, we developed a seed extraction and partial purification protocol for ergovaline/ergovalinine that provided a biologically active product. Tall fescue seed was ground and packed into several different sized columns for liquid extraction. Smaller particle size and increased extraction time increased efficiency of extraction. Our largest column was a 114 × 52 × 61 cm (W×L×D) stainless steel tub. Approximately 150 kg of seed could be extracted in this tub. The extraction was done with 80% ethanol. When the solvent front migrated to bottom of the column, flow was stopped and seed was allowed to steep for at least 48 h. Light was excluded from the solvent from the beginning of this step to the end of the purification process. Following elution, ethanol was removed from the eluate by evaporation at room temperature. Resulting syrup was freeze-dried. About 80% recovery of alkaloids was achieved with 18-fold increase in concentration of ergovaline. Initial purification of the dried product was accomplished by extracting with hexane/water (6:1, v/v) and the hexane fraction was discarded. The aqueous fraction was extracted with chloroform, the aqueous layer discarded, after which the chloroform was removed with a resulting 20-fold increase of ergovaline. About 65% of the ergovaline was recovered from the chloroform residue for an overall recovery of 50%. The resultant partially purified ergovaline had biological activities in in vivo and in vitro bovine bioassays that approximate that of synthetic ergovaline.

A smooth muscle tone-dependent stretch-activated migrating motor pattern in isolated guinea-pig distal colon.

PubMed

Smith, Terence K; Oliver, Gavin R; Hennig, Grant W; O'Shea, Deirdre M; Vanden Berghe, Pieter; Kang, Sok Han; Spencer, Nick J

2003-09-15

We have investigated the tone dependence of the intrinsic nervous activity generated by localized wall distension in isolated segments of guinea-pig distal colon using mechanical recordings and video imaging of wall movements. A segment of colon was threaded through two partitions, which divided the colon for pharmacological purposes into oral, stimulation and anal regions. An intraluminal balloon was located in the stimulation region between the two partitions (12 mm apart). Maintained colonic distension by an intraluminal balloon or an artificial faecal pellet held at a fixed location generated rhythmic (frequency 0.3 contractions min(-1); duration approximately 60 s) peristaltic waves of contraction. Video imaging of colonic wall movements or the selective application of pharmacological agents suggested that peristaltic waves originated just oral (< or = 4 mm) to the pellet and propagated both orally (approximately 11 mm s(-1)) and anally (approximately 1 mm s(-1)). Also, during a peristaltic wave the colon appears to passively shorten in front of a pellet, as a result of an active contraction of the longitudinal muscle oral to the pellet. Faecal pellet movement only occurred when a rhythmic peristaltic wave was generated. Rhythmic peristaltic waves were abolished in all regions by the smooth muscle relaxants isoproterenol (1 microM), nicardipine (1 microM) or papavarine (10 microM), and by the neural antagonists tetrodotoxin (TTX; 0.6 microM), hexamethonium (100 microM) or atropine (1 microM), when added selectively to the stimulation region. Nicardipine, atropine, TTX, or hexamethonium (100 microM) also blocked the evoked peristaltic waves when selectively added to the oral region. Nomega-nitro-L-arginine (L-NA; 100 microM) added to the anal region reduced the anal relaxation but increased the anal contraction, leading to an increase in the apparent conduction velocity of each peristaltic wave. In conclusion, maintained distension by a fixed artificial pellet generates propulsive, rhythmic peristaltic waves, whose enteric neural activity is critically dependent upon smooth muscle tone. These peristaltic waves usually originate just oral to the pellet, and their apparent conduction velocity is generated by activation of descending inhibitory nerve pathways.

Urban ecosystems and the North American carbon cycle

Treesearch

D.E. Pataki; R.J. Alig; A.S. Fung; N.E. Golubiewski; C.A. Kennedy; E.G. McPherson; D.J. Nowak; R.V. Pouyat; P.R. Lankao

2006-01-01

Approximately 75–80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in...

Two substorm studies of relations between westward electric fields in the outer plasmasphere, auroral activity, and geomagnetic perturbations

NASA Technical Reports Server (NTRS)

Carpenter, D. L.; Akasofu, S.

1972-01-01

Temporal variations of the westward component of the magnetospheric convection electric field in the outer plasmasphere were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer plasmasphere increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.

Intracellular Cs+ activates the PKA pathway, revealing a fast, reversible, Ca2+-dependent inactivation of L-type Ca2+ current.

PubMed

Brette, Fabien; Lacampagne, Alain; Sallé, Laurent; Findlay, Ian; Le Guennec, Jean-Yves

2003-08-01

Inactivation of the L-type Ca2+ current (ICaL) was studied in isolated guinea pig ventricular myocytes with different ionic solutions. Under basal conditions, ICaL of 82% of cells infused with Cs+-based intracellular solutions showed enhanced amplitude with multiphasic decay and diastolic depolarization-induced facilitation. The characteristics of ICaL in this population of cells were not due to contamination by other currents or an artifact. These phenomena were reduced by ryanodine, caffeine, cyclopiazonic acid, the protein kinase A inhibitor H-89, and the cAMP-dependent protein kinase inhibitor. Forskolin and isoproterenol increased ICaL by only approximately 60% in these cells. Cells infused with either N-methyl-d-glucamine or K+-based intracellular solutions did not show multiphasic decay or facilitation under basal conditions. Isoproterenol increased ICaL by approximately 200% in these cells. In conclusion, we show that multiphasic inactivation of ICaL is due to Ca2+-dependent inactivation that is reversible on a time scale of tens of milliseconds. Cs+ seems to activate the cAMP-dependent protein kinase pathway when used as a substitute for K+ in the pipette solution.

Identification of a hepatoprotective peptide in wheat gluten hydrolysate against D-galactosamine-induced acute hepatitis in rats.

PubMed

Sato, Kenji; Egashira, Yukari; Ono, Shin; Mochizuki, Satoshi; Shimmura, Yuki; Suzuki, Yoshio; Nagata, Megumi; Hashimoto, Kaori; Kiyono, Tamami; Park, Eun Young; Nakamura, Yasushi; Itabashi, Mariko; Sakata, Yuka; Furuta, Seigo; Sanada, Hiroo

2013-07-03

A hepatoprotective peptide, pyroglutamyl leucine (pyroGlu-Leu), was identified in wheat gluten hydrolysate through an in vivo activity-guided fractionation approach based on D-galactosamine-induced acute hepatitis in rats and fractionation of peptides with large-scale preparative ampholine-free isoelectric focusing. The active acidic fraction predominantly consisted of pyroglutamyl peptides and free pyroglutamic acid. Pyroglutamyl peptides were derivatized with phenyl isothiocyanate after removal of a pyroglutamyl residue by pyroglutamate aminopeptidase. The derivatives were purified by reversed-phase HPLC and subjected to sequence analysis. The active fraction contained pyroGlu-Ile, pyroGlu-Leu, pyroGlu-Gln, pyroGlu-Gln-Gln, and free pyroGlu. Ingestion of pyroGlu-Leu at 20 mg/kg body weight significantly decreased serum aspartate and alanine aminotransferases to approximately 30% and 20% of those values of the vehicle group, respectively, which were near the normal levels. Thirty minutes after ingestion of pyroGlu-Leu at 20 mg/kg, the concentration of pyroGlu-Leu in portal blood plasma increased to approximately 2 μM.

UV-induced changes of active components and antioxidant activity in postharvest pigeon pea [Cajanus cajan (L.) Millsp.] leaves.

PubMed

Wei, Zuo-Fu; Luo, Meng; Zhao, Chun-Jian; Li, Chun-Ying; Gu, Cheng-Bo; Wang, Wei; Zu, Yuan-Gang; Efferth, Thomas; Fu, Yu-Jie

2013-02-13

In this study, the effect of UV irradiation (UV-A, UV-B, and UV-C) on phytochemicals, total phenolics, and antioxidant activity of postharvest pigeon pea leaves was evaluated. The response of pigeon pea leaves to UV irradiation was phytochemical specific. UV-B and UV-C induced higher levels of phytochemicals, total phenolics, and antioxidant activity in pigeon pea leaves compared with UV-A. Furthermore, UV-B irradiation proved to possess a long-lasting effect on the levels of phenolics and antioxidant activity. After adapting for 48 h at 4 °C following 4 h UV-B irradiation, total phenolics and antioxidant activity were approximately 1.5-fold and 2.2-fold increased from 39.4 mg GAE/g DM and 15.0 μmol GAE/g DM to 59.1 mg GAE/g DM and 32.5 μmol GAE/g DM, respectively. These results indicate that UV irradiation of pigeon pea leaves can be beneficial in terms of increasing active components and antioxidant activity.

Genotoxicity and osteogenic potential of sulfated polysaccharides from Caulerpa prolifera seaweed.

PubMed

Chaves Filho, Gildácio Pereira; de Sousa, Angélica Fernandes Gurgel; Câmara, Rafael Barros Gomes; Rocha, Hugo Alexandre Oliveira; de Medeiros, Silvia Regina Batistuzzo; Moreira, Susana Margarida Gomes

2018-07-15

Marine algae are sources of novel bioactive molecules and present a great potential for biotechnological and biomedical applications. Although green algae are the least studied type of seaweed, several of their biological activities have already been described. Here, we investigated the osteogenic potential of Sulfated Polysaccharide (SP)-enriched samples extracted from the green seaweed Caulerpa prolifera on human mesenchymal stem cells isolated from Wharton jelly (hMSC-WJ). In addition, the potential genotoxicity of these SPs was determined by cytokinesis-block micronucleus (CBMN) assay. SP-enriched samples did not show significant cytotoxicity towards hMSCs-WJ at a concentration of up to 10μg/mL, and after 72h of exposure. SP enrichment also significantly increased alkaline phosphatase (ALP) activity, promoting calcium accumulation in the extracellular matrix. Among the SP-enriched samples, the CP0.5 subfraction (at 5μg/mL) presented the most promising results. In this sample, ALP activity was increased approximately by 60%, and calcium accumulation was approximately 6-fold above the negative control, indicating high osteogenic potential. This subfraction also proved to be non-genotoxic, according to the CBMN assay, as it did not induce micronuclei. The results of this study highlight, for the first time, the potential of these SPs for the development of new therapies for bone regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Wang, Dong; Liu, Rui; Wang, Yuming

We studied the background field for 60 two-ribbon flares of M-and-above classes during 2011–2015. These flares are categorized into two groups, i.e., eruptive and confined flares, based on whether a flare is associated with a coronal mass ejection or not. The background field of source active regions is approximated by a potential field extrapolated from the B {sub z} component of vector magnetograms provided by the Helioseismic and Magnetic Imager. We calculated the decay index n of the background field above the flaring polarity inversion line, and defined a critical height h {sub crit} corresponding to the theoretical threshold (more » n {sub crit} = 1.5) of the torus instability. We found that h {sub crit} is approximately half of the distance between the centroids of opposite polarities in active regions and that the distribution of h {sub crit} is bimodal: it is significantly higher for confined flares than for eruptive ones. The decay index increases monotonously with increasing height for 86% (84%) of the eruptive (confined) flares but displays a saddle-like profile for the rest, 14% (16%), which are found exclusively in active regions of multipolar field configuration. Moreover, n at the saddle bottom is significantly smaller in confined flares than that in eruptive ones. These results highlight the critical role of background field in regulating the eruptive behavior of two-ribbon flares.« less

Identification of novel isoform-selective inhibitors within class I histone deacetylases.

PubMed

Hu, Erding; Dul, Edward; Sung, Chiu-Mei; Chen, Zunxuan; Kirkpatrick, Robert; Zhang, Gui-Feng; Johanson, Kyung; Liu, Ronggang; Lago, Amparo; Hofmann, Glenn; Macarron, Ricardo; de los Frailes, Maite; Perez, Paloma; Krawiec, John; Winkler, James; Jaye, Michael

2003-11-01

Histone deacetylases (HDACs) represent an expanding family of protein modifying-enzymes that play important roles in cell proliferation, chromosome remodeling, and gene transcription. We have previously shown that recombinant human HDAC8 can be expressed in bacteria and retain its catalytic activity. To further explore the catalytic activity of HDACs, we expressed two additional human class I HDACs, HDAC1 and HDAC3, in baculovirus. Recombinant HDAC1 and HDAC3 fusion proteins remained soluble and catalytically active and were purified to near homogeneity. Interestingly, trichostatin (TSA) was found to be a potent inhibitor for all three HDACs (IC50 value of approximately 0.1-0.3 microM), whereas another HDAC inhibitor MS-27-275 (N-(2-aminophenyl)-4-[N-(pyridin-3-methyloxycarbonyl)-aminomethyl]benzamide) preferentially inhibited HDAC1 (IC50 value of approximately 0.3 microM) versus HDAC3 (IC50 value of approximately 8 microM) and had no inhibitory activity toward HDAC8 (IC50 value >100 microM). MS-27-275 as well as TSA increased histone H4 acetylation, induced apoptosis in the human colon cancer cell line SW620, and activated the simian virus 40 early promoter. HDAC1 protein was more abundantly expressed in SW620 cells compared with that of HDAC3 and HDAC8. Using purified recombinant HDAC proteins, we identified several novel HDAC inhibitors that preferentially inhibit HDAC1 or HDAC8. These inhibitors displayed distinct properties in inducing histone acetylation and reporter gene expression. These results suggest selective HDAC inhibitors could be identified using recombinantly expressed HDACs and that HDAC1 may be a promising therapeutic target for designing HDAC inhibitors for proliferative diseases such as cancer.

Histochemical studies on protease formation in the cotyledons of germinating bean seeds.

PubMed

Yomo, H; Taylor, M P

1973-03-01

Protease formation in Phaseolus vulgaris L. cotyledons during seed germination was studied histochemically using a gelatin-film-substrate method. Protease activity can be detected by this method on the 5th day of germination, at approximately the same time that a rapid increase of activity was observed by a test-tube assay with casein as a substrate. At the early stage of germination, protease activity was observed throughout the cotyledon except in two or three cell layers below the cotyledon surface and in several cell layers around the vascular bundles. A highly active cell layer surrounding the protease-inactive cells near the vascular bundles is suggested to be a source of the protease.

Pseudochemotaxis in inhomogeneous active Brownian systems

NASA Astrophysics Data System (ADS)

Vuijk, Hidde D.; Sharma, Abhinav; Mondal, Debasish; Sommer, Jens-Uwe; Merlitz, Holger

2018-04-01

We study dynamical properties of confined, self-propelled Brownian particles in an inhomogeneous activity profile. Using Brownian dynamics simulations, we calculate the probability to reach a fixed target and the mean first passage time to the target of an active particle. We show that both these quantities are strongly influenced by the inhomogeneous activity. When the activity is distributed such that high-activity zone is located between the target and the starting location, the target finding probability is increased and the passage time is decreased in comparison to a uniformly active system. Moreover, for a continuously distributed profile, the activity gradient results in a drift of active particle up the gradient bearing resemblance to chemotaxis. Integrating out the orientational degrees of freedom, we derive an approximate Fokker-Planck equation and show that the theoretical predictions are in very good agreement with the Brownian dynamics simulations.

Study on Current Levels of Physical Activity and Sedentary Behavior among Middle School Students in Beijing, China.

PubMed

Duan, Jiali; Hu, Huanhuan; Wang, Guan; Arao, Takashi

2015-01-01

This study aimed to determine current levels of physical activity and sedentary behavior in middle school students on the basis of grade, sex, student attitudes toward physical education, and residence location. In 2013, a cross-sectional study of 1793 students aged 12 to 15 years was conducted across eight middle schools in Beijing, China. Four schools were selected from an urban district and another four schools were from a suburban district. Physical activity and sedentary behavior data were collected using the commonly used school-based Chinese version of the China Health and Nutrition Survey. The mean age of sampled students was 13.3 ± 1.0 years; 51.5% were boys. Approximately 76.6% of students reported having three 45-minute physical education classes every week. A total of 35.6% students spent ≥ 1 h/day performing moderate to vigorous physical activity (MVPA) during school, and 34.9% spent ≥ 1 h/day in MVPA outside school time. Approximately half (49.7%) of the students engaged in reading, writing, or drawing for ≥ 2 h/day, and 42.9% reported screen time for ≥ 2 h/day. Although boys spent more time engaged in physical activity than girls did, they also spent more time exhibiting sedentary behavior. Each 10-unit increase in attitudes toward physical education was associated with an increased odds of 1.15 (95%CI: 1.09-1.20) for spending more than 1 h/day on MVPA. Students in suburban schools reported engaging in physical activity less when compared with those in urban schools. The majority of our students did not meet the current physical activity recommendations, and about half of the students spent excessive time engaging in sedentary behaviors. Findings from this study highlight a positive association between student attitudes toward physical education and physical activity. Studies are needed to further explore the role of student attitudes toward physical education in promoting physical activity among Chinese students.

Renilla luciferase-based quantitation of Potato virus A infection initiated with Agrobacterium infiltration of N. benthamiana leaves.

PubMed

Eskelin, K; Suntio, T; Hyvärinen, S; Hafren, A; Mäkinen, K

2010-03-01

A quantitation method based on the sensitive detection of Renilla luciferase (Rluc) activity was developed and optimized for Potato virus A (PVA; genus Potyviridae) gene expression. This system is based on infections initiated by Agrobacterium infiltration and subsequent detection of the translation of PVA::Rluc RNA, which is enhanced by viral replication, first within the cells infected initially and later by translation and replication within new cells after spread of the virus. Firefly luciferase (Fluc) was used as an internal control to normalize the Rluc activity. An approximately 10-fold difference in the Rluc/Fluc activity ratio between a movement-deficient and a replication-deficient mutant was observed starting from 48h post Agrobacterium infiltration (h.p.i.). The Rluc activity derived from wild type (wt) PVA increased significantly between 48 and 72h.p.i. and the Rluc/Fluc activity deviated clearly from that of the mutant viruses. Quantitation of the Rluc and Fluc mRNAs by semi-quantitative RT-PCR indicated that increases and decreases in the Renillareniformis luciferase (rluc) mRNA levels coincided with changes in Rluc activity. However, a subtle increase in the mRNA level led to pronounced changes in Rluc activity. PVA CP accumulation was quantitated by enzyme-linked immunosorbent assay. The increase in Rluc activity correlated closely with virus accumulation. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Vascular filtration function in galactose-fed versus diabetic rats: The role of polyol pathway activity

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

Pugliese, G.; Tilton, R.G.; Speedy, A.

1990-07-01

These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2more » mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion of endogenous albumin and IgG were increased approximately 10-fold. Sorbinil treatment markedly reduced or completely prevented all of these changes in galactose-fed, as well as in diabetic rats. These observations support the hypothesis that increased metabolism of glucose via the sorbitol pathway is of central importance in mediating virtually all of the early changes in vascular filtration function associated with diabetes in the kidney, as well as in the eyes, nerves, and aorta. On the other hand, renal hypertrophy in diabetic rats and polyuria, hyperphagia, and impaired weight gain in galactose-fed and in diabetic rats were unaffected by sorbinil and therefore are unlikely to be mediated by increased polyol metabolism.« less

Active Brownian particles near straight or curved walls: Pressure and boundary layers

NASA Astrophysics Data System (ADS)

Duzgun, Ayhan; Selinger, Jonathan V.

2018-03-01

Unlike equilibrium systems, active matter is not governed by the conventional laws of thermodynamics. Through a series of analytic calculations and Langevin dynamics simulations, we explore how systems cross over from equilibrium to active behavior as the activity is increased. In particular, we calculate the profiles of density and orientational order near straight or circular walls and show the characteristic width of the boundary layers. We find a simple relationship between the enhancements of density and pressure near a wall. Based on these results, we determine how the pressure depends on wall curvature and hence make approximate analytic predictions for the motion of curved tracers, as well as the rectification of active particles around small openings in confined geometries.

Kinetics of killing Listeria monocytogenes by macrophages: rapid killing accompanying phagocytosis

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

Davies, W.A.

1983-08-01

The kinetics of bactericidal activity of activated macrophages can be precisely described by a mathematical model in which phagocytosis, killing, digestion, and release of degraded bacterial material are considered to occur continuously. To gain a better understanding of these events, I have determined the period of time between first contact of bacteria with macrophages and the onset of killing. Activated rat peritoneal macrophages were incubated for various times up to 15 min with Listeria monocytogenes previously labeled with /sup 3/H-thymidine and the unassociated bacteria removed by two centrifugations through a density interface. Both cell-associated radioactivity and cell-associated viable bacteria, determinedmore » as colony forming units after sonication of the cell pellet, increased with time of incubation. However, the specific viability of these bacteria, expressed as the ratio of number of viable bacteria per unit radioactivity declined with time, as an approximate inverse exponential, after a lag period of 2.9 +/- 0.8 min. Evidence is given that other possible causes for this decline in specific viability, other than death of the bacteria, such as preferential ingestion of dead Listeria, clumping of bacteria, variations in autolytic activity, or release of Listericidins are unlikely. I conclude therefore that activated macrophages kill Listeria approximately 3 min after the cell and the bacterium first make contact.« less

Adsorption of cadmium by activated carbon cloth: influence of surface oxidation and solution pH.

PubMed

Rangel-Mendez, J R; Streat, M

2002-03-01

The surface of activated carbon cloth (ACC), based on polyacrylonitrile fibre as a precursor, was oxidised using nitric acid, ozone and electrochemical oxidation to enhance cadmium ion exchange capacity. Modified adsorbents were physically and chemically characterised by pH titration, direct titration, X-ray photoelectron spectroscopy, elemental analysis, surface area and porosimetry, and scanning electron microscopy. BET surface area decreased after oxidation, however, the total ion exchange capacity increased by a factor of approximately 3.5 compared to the commercial as-received ACC. A very significant increase in cadmium uptake, by a factor of 13, was observed for the electrochemically oxidised ACC. Equilibrium sorption isotherms were determined at pH 4, 5 and 6 and these showed that cadmium uptake increased with increasing pH. There was clear evidence of physical damage to ozone-oxidised fibre, however, acid and electrochemically oxidised samples were completely stable.

Smooth muscle of telokin-deficient mice exhibits increased sensitivity to Ca2+ and decreased cGMP-induced relaxation.

PubMed

Khromov, A S; Wang, H; Choudhury, N; McDuffie, M; Herring, B P; Nakamoto, R; Owens, G K; Somlyo, A P; Somlyo, A V

2006-02-14

Cyclic nucleotides can relax smooth muscle without a change in [Ca2+]i, a phenomenon termed Ca2+ desensitization, contributing to vasodilation, gastrointestinal motility, and airway resistance. The physiological importance of telokin, a 17-kDa smooth muscle-specific protein and target for cyclic nucleotide-induced Ca2+ desensitization, was determined in telokin null mice bred to a congenic background. Telokin null ileal smooth muscle homogenates compared to wild type exhibited an approximately 30% decrease in myosin light-chain phosphatase (MLCP) activity, which was reflected in a significant leftward shift (up to 2-fold at pCa 6.3) of the Ca2+ force relationship accompanied by an increase in myosin light-chain phosphorylation. No difference in the Ca2+ force relationship occurred in telokin WT and knockout (KO) aortas, presumably reflecting the normally approximately 5-fold lower telokin content in aorta vs. ileum smooth muscle. Ca2+ desensitization of contractile force by 8-Br-cGMP was attenuated by 50% in telokin KO intestinal smooth muscle. The rate of force relaxation reflecting MLCP activity, in the presence of 50 microM 8-Br-cGMP, was also significantly slowed in telokin KO vs. WT ileum and was rescued by recombinant telokin. Normal thick filaments in telokin KO smooth muscles indicate that telokin is not required for filament formation or stability. Results indicate that a primary role of telokin is to modulate force through increasing MLCP activity and that this effect is further potentiated through phosphorylation by cGMP in telokin-rich smooth tissues.

Improvement of oxytetracycline production mediated via cooperation of resistance genes in Streptomyces rimosus.

PubMed

Yin, Shouliang; Wang, Xuefeng; Shi, Mingxin; Yuan, Fang; Wang, Huizhuan; Jia, Xiaole; Yuan, Fang; Sun, Jinliang; Liu, Tiejun; Yang, Keqian; Zhang, Yuxiu; Fan, Keqiang; Li, Zilong

2017-09-01

Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics. To increase the oxytetracycline (OTC) production in Streptomyces rimosus, we investigated the cooperative effect of three co-overexpressing OTC resistance genes: one gene encodes a ribosomal protection protein (otrA) and the other two express efflux proteins (otrB and otrC). Results indicated that combinational overexpression of otrA, otrB, and otrC (MKABC) exerted a synergetic effect. OTC production increased by 179% in the recombinant strain compared with that of the wild-type strain M4018. The resistance level to OTC was increased by approximately two-fold relative to the parental strain, thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production. Furthermore, the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC; such strain can produce OTC of approximately 7.49 g L -1 , which represents an increase of 19% in comparison with that of the OtcR-overexpressing strain alone. Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.

Antioxidative activity and growth regulation of Brassicaceae induced by oxygen radical irradiation

NASA Astrophysics Data System (ADS)

Hayashi, Nobuya; Ono, Reoto; Shiratani, Masaharu; Yonesu, Akira

2015-06-01

The growth regulation characteristics of plants are investigated when plant seeds are irradiated with atmospheric discharge plasma. Enhancement of the germination and lengths of the stem and root of plants are observed after seeding. The total length of the stem and root increases approximately 1.6 times after a cultivation period of 72 h. The growth regulation effect is found to be maintained for 80 h of cultivation after seeding. The growth regulation originates from the change in the antioxidative activity of plant cells induced by active oxygen species generated in the oxygen plasma, which leads to the production of growth factor in plants.

Energy-density enhancement of carbon-nanotube-based supercapacitors with redox couple in organic electrolyte.

PubMed

Park, Jinwoo; Kim, Byungwoo; Yoo, Young-Eun; Chung, Haegeun; Kim, Woong

2014-11-26

We demonstrate for the first time that the incorporation of a redox-active molecule in an organic electrolyte can increase the cell voltage of a supercapacitor. The redox molecule also contributes to increasing the cell capacitance by a faradaic redox reaction, and therefore the energy density of the supercapacitor can be significantly increased. More specifically, the addition of redox-active decamethylferrocene in an organic electrolyte results in an approximately 27-fold increase in the energy density of carbon-nanotube-based supercapacitors. The resulting high energy density (36.8 Wh/kg) stems from the increased cell voltage (1.1 V→2.1 V) and cell capacitance (8.3 F/g→61.3 F/g) resulting from decamethylferrocene addition. We found that the voltage increase is associated with the potential of the redox species relative to the electrochemical stability window of the supporting electrolyte. These results will be useful in identifying new electrolytes for high-energy-density supercapacitors.

A thermostable variant of fructose bisphosphate aldolase constructed by directed evolution also shows increased stability in organic solvents.

PubMed

Hao, Jijun; Berry, Alan

2004-09-01

Thermostable variants of the Class II fructose bisphosphate aldolase have been isolated following four rounds of directed evolution using DNA shuffling of the fda genes from Escherichia coli and Edwardsiella ictaluri. Variants from all four generations of evolution have been purified and characterized. The variants show increased thermostability with no loss of catalytic function at room temperature. The temperature at which 50% of the initial enzyme activity is lost after incubation for 10 min (T50) of the most stable variant, 4-43D6, is increased by 11-12 degrees C over the wild-type enzymes and the half-life of activity at 53 degrees C is increased approximately 190-fold. In addition, variant 4-43D6 shows increased stability to treatment with organic solvents. DNA sequencing of the evolved variants has identified the mutations which have been introduced and which lead to increased thermostability, and the role of the mutations introduced is discussed.

Experimental hyperthyroidism in rats increases the expression of the ubiquitin ligases atrogin-1 and MuRF1 and stimulates multiple proteolytic pathways in skeletal muscle.

PubMed

O'Neal, Patrick; Alamdari, Nima; Smith, Ira; Poylin, Vitaliy; Menconi, Michael; Hasselgren, Per-Olof

2009-11-01

Muscle wasting is commonly seen in patients with hyperthyroidism and is mainly caused by stimulated muscle proteolysis. Loss of muscle mass in several catabolic conditions is associated with increased expression of the muscle-specific ubiquitin ligases atrogin-1 and MuRF1 but it is not known if atrogin-1 and MuRF1 are upregulated in hyperthyroidism. In addition, it is not known if thyroid hormone increases the activity of proteolytic mechanisms other than the ubiquitin-proteasome pathway. We tested the hypotheses that experimental hyperthyroidism in rats, induced by daily intraperitoneal injections of 100 microg/100 g body weight of triiodothyronine (T3), upregulates the expression of atrogin-1 and MuRF1 in skeletal muscle and stimulates lysosomal, including cathepsin L, calpain-, and caspase-3-dependent protein breakdown in addition to proteasome-dependent protein breakdown. Treatment of rats with T3 for 3 days resulted in an approximately twofold increase in atrogin-1 and MuRF1 mRNA levels. The same treatment increased proteasome-, cathepsin L-, and calpain-dependent proteolytic rates by approximately 40% but did not influence caspase-3-dependent proteolysis. The expression of atrogin-1 and MuRF1 remained elevated during a more prolonged period (7 days) of T3 treatment. The results provide support for a role of the ubiquitin-proteasome pathway in muscle wasting during hyperthyroidism and suggest that other proteolytic pathways as well may be activated in the hyperthyroid state. (c) 2009 Wiley-Liss, Inc.

Regulation of adult cardiocyte growth: effects of active and passive mechanical loading

NASA Technical Reports Server (NTRS)

Decker, M. L.; Janes, D. M.; Barclay, M. M.; Harger, L.; Decker, R. S.

1997-01-01

Fluctuations in hemodynamic load have been documented to modulate contractile protein turnover and myofibrillar structure in the heart; however, the relative importance of active and passive loading in regulating adult cardiocyte growth remains unresolved. To address this issue at the cellular level, adult feline cardiocytes were cultured either on Silastic membranes or plastic surfaces. Cardiocyte-laden membranes were stretched 10% of their rest length to enhance passive loading, whereas heart cells cultured on plastic or Silastic were field stimulated at 1 Hz to mimic active loading. Turnover of contractile proteins and structural integrity of the contractile-cytoskeletal apparatus were monitored for periods ranging from 4 to 72 h. Active and passive loading elevated contractile protein synthesis nearly equally (approximately 50%) and promoted the attachment of remodeled myofibrils to vinculin-positive focal contacts and/or costameres during the first 24 h of loading. Thereafter, rates of contractile protein synthesis returned to control values in passively stretched heart cells but remained elevated in field-stimulated cultures. The fractional rate of growth was increased significantly (approximately 8%/day) in electrically paced cells, whereas in passively stretched cardiocytes the growth rate rose only modestly (approximately 2%/day). Changes in the rate of myocyte growth appeared more closely correlated with the development of focal contacts and myofibril remodeling than with changes in myofibrillar protein turnover per se. 2,3-Butanedione monoxime, nifedipine, and, to a lesser extent, ryanodine blocked field-stimulated contractile protein synthesis and myofibrillar remodeling but had no impact on protein turnover or myofibril reassembly in passively loaded cardiocytes. The results of these experiments imply that both active and passive loading stimulate contractile protein turnover and myofibril remodeling, but the generation of active tension accelerates cardiocyte growth to a greater extent than passive loading. Furthermore, pharmacological interventions suggest that unique pathways may mediate these cellular events in actively and passively loaded adult cardiocytes.

Regulation of adult cardiocyte growth: effects of active and passive mechanical loading.

PubMed

Decker, M L; Janes, D M; Barclay, M M; Harger, L; Decker, R S

1997-06-01

Fluctuations in hemodynamic load have been documented to modulate contractile protein turnover and myofibrillar structure in the heart; however, the relative importance of active and passive loading in regulating adult cardiocyte growth remains unresolved. To address this issue at the cellular level, adult feline cardiocytes were cultured either on Silastic membranes or plastic surfaces. Cardiocyte-laden membranes were stretched 10% of their rest length to enhance passive loading, whereas heart cells cultured on plastic or Silastic were field stimulated at 1 Hz to mimic active loading. Turnover of contractile proteins and structural integrity of the contractile-cytoskeletal apparatus were monitored for periods ranging from 4 to 72 h. Active and passive loading elevated contractile protein synthesis nearly equally (approximately 50%) and promoted the attachment of remodeled myofibrils to vinculin-positive focal contacts and/or costameres during the first 24 h of loading. Thereafter, rates of contractile protein synthesis returned to control values in passively stretched heart cells but remained elevated in field-stimulated cultures. The fractional rate of growth was increased significantly (approximately 8%/day) in electrically paced cells, whereas in passively stretched cardiocytes the growth rate rose only modestly (approximately 2%/day). Changes in the rate of myocyte growth appeared more closely correlated with the development of focal contacts and myofibril remodeling than with changes in myofibrillar protein turnover per se. 2,3-Butanedione monoxime, nifedipine, and, to a lesser extent, ryanodine blocked field-stimulated contractile protein synthesis and myofibrillar remodeling but had no impact on protein turnover or myofibril reassembly in passively loaded cardiocytes. The results of these experiments imply that both active and passive loading stimulate contractile protein turnover and myofibril remodeling, but the generation of active tension accelerates cardiocyte growth to a greater extent than passive loading. Furthermore, pharmacological interventions suggest that unique pathways may mediate these cellular events in actively and passively loaded adult cardiocytes.

Self-Nanoemulsifying Drug Delivery System for Resveratrol: Enhanced Oral Bioavailability and Reduced Physical Fatigue in Rats

PubMed Central

Yen, Ching-Chi; Hsu, Mei-Chich; Wu, Yu-Tse

2017-01-01

Resveratrol (RES), a natural polyphenolic compound, exerts anti-fatigue activity, but its administration is complicated by its low water solubility. To improve RES bioavailability, this study developed a self-nanoemulsifying drug delivery system (SNEDDS) for RES and evaluated its anti-fatigue activity and rat exercise performance by measuring fatigue-related parameters, namely lactate, ammonia, plasma creatinine phosphokinase, and glucose levels and the swimming time to exhaustion. Through solubility and emulsification testing, the optimized SNEDDS composed of Capryol 90, Cremophor EL, and Tween 20 was developed; the average particle size in this formulation, which had favorable self-emulsification ability, was approximately 41.3 ± 4.1 nm. Pharmacokinetic studies revealed that the oral bioavailability of the optimized RES-SNEDDS increased by 3.2-fold compared with that of the unformulated RES-solution. Pretreatment using the RES-SNEDDS before exercise accelerated the recovery of lactate after exercise; compared with the vehicle group, the plasma ammonia level in the RES-SNEDDS group significantly decreased by 65.4%, whereas the glucose level significantly increased by approximately 1.8-fold. Moreover, the swimming time to exhaustion increased by 2.1- and 1.8-fold, respectively, compared with the vehicle and RES-solution pretreatment groups. Therefore, the developed RES-SNEDDS not only enhances the oral bioavailability of RES but may also exert anti-fatigue pharmacological effect. PMID:28841149

Increased expression and processing of caspase-12 after traumatic brain injury in rats.

PubMed

Larner, Stephen F; Hayes, Ronald L; McKinsey, Deborah M; Pike, Brian R; Wang, Kevin K W

2004-01-01

Traumatic brain injury (TBI) disrupts tissue homeostasis resulting in pathological apoptotic activation. Recently, caspase-12 was reported to be induced and activated by the unfolded protein response following excess endoplasmic reticulum (ER) stress. This study examined rat caspase-12 expression using the controlled cortical impact TBI model. Immunoblots of fractionalized cell lysates found elevated caspase-12 proform (approximately 60 kDa) and processed form (approximately 12 kDa), with peak induction observed within 24 h post-injury in the cortex (418% and 503%, respectively). Hippocampus caspase-12 proform induction peaked at 24 h post-injury (641%), while processed form induction peaked at 6 h (620%). Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed elevated caspase-12 mRNA levels after TBI. Injury severity (1.0, 1.2 or 1.6 mm compression) was associated with increased caspase-12 mRNA expression, peaking at 5 days in the cortex (657%, 651% and 1259%, respectively) and 6 h in the hippocampus (435%, 451% and 460%, respectively). Immunohistochemical analysis revealed caspase-12 induction in neurons in both the cortex and hippocampus as well as in astrocytes at the contusion site. This is the first report of increased expression of caspase-12 following TBI. Our results suggest that the caspase-12-mediated ER apoptotic pathway may play a role in rat TBI pathology independent of the receptor- or mitochondria-mediated apoptotic pathways.

Benzil, a potent activator of microsomal epoxide hydrolase in vitro.

PubMed

Seidegård, J; DePierre, J W

1980-12-01

Benzil was found to be a very potent activator of microsomal epoxide hydrolase activity (measured with styrene oxide as substrate) in vitro. The activating effect was uncompetitive and benzil causes approximately ninefold increases in both the apparent V and the apparent Km of the enzyme(s). The half-maximal effect on activity was obtained as a 0.3 mM concentration of benzil. The activating effect obtained with benzil was found to be very specific, since a variety of structurally related compounds had little or no effect on microsomal epoxide hydrolase activity. In order to obtain indications for the existence of more than one microsomal epoxide hydrolase the effect of benzil on this activity from rats induced with phenobarbital, 3-methylcholanthrene, 2-acetylaminofluorene, trans-stilbene oxide, and benzil was tested. The differences observed were minor.

Discharge patterns of human genioglossus motor units during arousal from sleep.

PubMed

Wilkinson, Vanessa; Malhotra, Atul; Nicholas, Christian L; Worsnop, Christopher; Jordan, Amy S; Butler, Jane E; Saboisky, Julian P; Gandevia, Simon C; White, David P; Trinder, John

2010-03-01

Single motor unit recordings of the human genioglossus muscle reveal motor units with a variety of discharge patterns. Integrated multiunit electromyographic recordings of genioglossus have demonstrated an abrupt increase in the muscle's activity at arousal from sleep. The aim of the present study was to determine the effect of arousal from sleep on the activity of individual motor units as a function of their particular discharge pattern. Genioglossus activity was measured using intramuscular fine-wire electrodes inserted via a percutaneous approach. Arousals from sleep were identified using the ASDA criterion and the genioglossus electromyogram recordings analyzed for single motor unit activity. Sleep research laboratory. Sleep and respiratory data were collected in 8 healthy subjects (6 men). 138 motor units were identified during prearousalarousal sleep: 25% inspiratory phasic, 33% inspiratory tonic, 4% expiratory phasic, 3% expiratory tonic, and 35% tonic. At arousal from sleep inspiratory phasic units significantly increased the proportion of a breath over which they were active, but did not appreciably increase their rate of firing. 80 new units were identified at arousals, 75% were inspiratory, many of which were active for only 1 or 2 breaths. 22% of units active before arousal, particularly expiratory and tonic units, stopped at the arousal. Increased genioglossus muscle activity at arousal from sleep is primarily due to recruitment of inspiratory phasic motor units. Further, activity within the genioglossus motoneuron pool is reorganized at arousal as, in addition to recruitment, approximately 20% of units active before arousals stopped firing.

Chronic coffee and caffeine ingestion effects on the cognitive function and antioxidant system of rat brains.

PubMed

Abreu, Renata Viana; Silva-Oliveira, Eliane Moretto; Moraes, Márcio Flávio Dutra; Pereira, Grace Schenatto; Moraes-Santos, Tasso

2011-10-01

Coffee is a popular beverage consumed worldwide and its effect on health protection has been well studied throughout literature. This study investigates the effect of chronic coffee and caffeine ingestion on cognitive behavior and the antioxidant system of rat brains. The paradigms of open field and object recognition were used to assess locomotor and exploratory activities, as well as learning and memory. The antioxidant system was evaluated by determining the activities of glutathione reductase (GR), glutathione peroxidase (GPx) and superoxide dismutase (SOD), as well as the lipid peroxidation and reduced glutathione content. Five groups of male rats were fed for approximately 80 days with different diets: control diet (CD), fed a control diet; 3% coffee diet (3%Co) and 6% coffee diet (6%Co), both fed a diet containing brewed coffee; 0.04% caffeine diet (0.04%Ca) and 0.08% caffeine diet (0.08%Ca), both fed a control diet supplemented with caffeine. The estimated caffeine intake was approximately 20 and 40 mg/kg per day, for the 3%Co-0.04%Ca and 6%Co-0.08%Ca treatments, respectively. At 90 days of life, the animals were subjected to the behavioral tasks and then sacrificed. The results indicated that the intake of coffee, similar to caffeine, improved long-term memory when tested with object recognition; however, this was not accompanied by an increase in locomotor and exploratory activities. In addition, chronic coffee and caffeine ingestion reduced the lipid peroxidation of brain membranes and increased the concentration of reduced-glutathione. The activities of the GR and SOD were similarly increased, but no change in GPx activity could be observed. Thus, besides improving cognitive function, our data show that chronic coffee consumption modulates the endogenous antioxidant system in the brain. Therefore, chronic coffee ingestion, through the protection of the antioxidant system, may play an important role in preventing age-associated decline in the cognitive function. Copyright © 2011 Elsevier Inc. All rights reserved.

Humanitarian Outreach in Cardiothoracic Surgery: From Setup to Sustainability.

PubMed

Dearani, Joseph A; Jacobs, Jeffrey P; Bolman, R Morton; Swain, JaBaris D; Vricella, Luca A; Weinstein, Samuel; Farkas, Emily A; Calhoon, John H

2016-09-01

Noncommunicable diseases account for 38 million deaths each year, and approximately 75% of these deaths occur in the developing world. The most common causes include cardiovascular diseases, cancer, respiratory diseases, and diabetes mellitus. Many adults with acquired cardiothoracic disease around the world have limited access to health care. In addition, congenital heart disease is present in approximately 1% of live births and is therefore the most common congenital abnormality. More than one million children in the world are born with congenital heart disease each year, and approximately 90% of these children receive suboptimal care or have no access to care. Furthermore, many children affected by noncongenital cardiac conditions also require prevention, diagnosis, and treatment. Medical and surgical volunteerism can help facilitate improvement in cardiothoracic health care in developing countries. As we move into the future, it is essential for physicians and surgeons to be actively involved in political, economic, and social aspects of society to serve health care interests of the underprivileged around the world. Consequently, in developing countries, a critical need exists to establish an increased number of reputable cardiothoracic programs and to enhance many of the programs that already exist. The optimal strategy is usually based on a long-term educational and technical model of support so that as case volumes increase, quality improves and mortality and morbidity decrease. Humanitarian outreach activities should focus on education and sustainability, and surgical tourism should be limited to those countries that will never have the capability to have free-standing cardiothoracic programs. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Pulmonary gas exchange is not impaired 24 h after extravehicular activity.

PubMed

Prisk, G Kim; Fine, Janelle M; Cooper, Trevor K; West, John B

2005-12-01

Extravehicular activity (EVA) during spaceflight involves a significant decompression stress. Previous studies have shown an increase in the inhomogeneity of ventilation-perfusion ratio (VA/Q) after some underwater dives, presumably through the embolic effects of venous gas microemboli in the lung. Ground-based chamber studies simulating EVA have shown that venous gas microemboli occur in a large percentage of the subjects undergoing decompression, despite the use of prebreathe protocols to reduce dissolved N(2) in the tissues. We studied eight crewmembers (7 male, 1 female) of the International Space Station who performed 15 EVAs (initial cabin pressure 748 mmHg, final suit pressure either approximately 295 or approximately 220 mmHg depending on the suit used) and who followed the denitrogenation procedures approved for EVA from the International Space Station. The intrabreath VA/Q slope was calculated from the alveolar Po(2) and Pco(2) in a prolonged exhalation maneuver on the day after EVA and compared with measurements made in microgravity on days well separated from the EVA. There were no significant changes in intrabreath VA/Q slope as a result of EVA, although there was a slight increase in metabolic rate and ventilation (approximately 9%) on the day after EVA. Vital capacity and other measures of pulmonary function were largely unaltered by EVA. Because measurements could only be performed on the day after EVA because of logistical constraints, we were unable to determine an acute effect of EVA on VA/Q inequality. The results suggest that current denitrogenation protocols do not result in any major lasting alteration to gas exchange in the lung.

Effect of a Single Musical Cakra Activation Manoeuvre on Body Temperature: An Exploratory Study

PubMed Central

Sumathy, Sundar; Parmar, Parin N

2016-01-01

Cakra activation/balancing and music therapy are part of the traditional Indian healing system. Little is known about effect of musical (vocal) technique of cakra activation on body temperature. We conducted a single-session exploratory study to evaluate effects of a single musical (vocal) cakra activation manoeuvre on body temperature in controlled settings. Seven healthy adults performed a single musical (vocal) cakra activation manoeuvre for approximately 12 minutes in controlled environmental conditions. Pre- and post-manoeuvre body temperatures were recorded with a clinical mercury thermometer. After a single manoeuvre, increase in body temperature was recorded in all seven subjects. The range of increase in body temperature was from 0.2°F to 1.4°F; with mean temperature rise being 0.5°F and median temperature rise being 0.4°F. We conclude that a single session of musical (vocal) technique of cakra activation elevated body temperatures in all 7 subjects. Further research is required to study effects of various cakra activation techniques on body temperature and other physiological parameters. PMID:28182030

Effect of a Single Musical Cakra Activation Manoeuvre on Body Temperature: An Exploratory Study.

PubMed

Sumathy, Sundar; Parmar, Parin N

2016-01-01

Cakra activation/balancing and music therapy are part of the traditional Indian healing system. Little is known about effect of musical (vocal) technique of cakra activation on body temperature. We conducted a single-session exploratory study to evaluate effects of a single musical (vocal) cakra activation manoeuvre on body temperature in controlled settings. Seven healthy adults performed a single musical (vocal) cakra activation manoeuvre for approximately 12 minutes in controlled environmental conditions. Pre- and post-manoeuvre body temperatures were recorded with a clinical mercury thermometer. After a single manoeuvre, increase in body temperature was recorded in all seven subjects. The range of increase in body temperature was from 0.2°F to 1.4°F; with mean temperature rise being 0.5°F and median temperature rise being 0.4°F. We conclude that a single session of musical (vocal) technique of cakra activation elevated body temperatures in all 7 subjects. Further research is required to study effects of various cakra activation techniques on body temperature and other physiological parameters.

A public health initiative to increase annual influenza immunization among hospital health care personnel: the San Diego Hospital Influenza Immunization Partnership.

PubMed

Sawyer, Mark H; Peddecord, K Michael; Wang, Wendy; Deguire, Michelle; Miskewitch-Dzulynsky, Michelle; Vuong, David D

2012-09-01

A public health department-supported intervention to increase influenza immunization among hospital-based health care practitioners (HCPs) in San Diego County took place between 2005 and 2008. The study included all major hospitals in the county, with a population of approximately 3.5 million. Information on hospital activities was collected from before, during and after initiative activities. Vaccination status and demographics were collected directly from HCP using hospital-based and random-dialed telephone surveys. Between 2006 and 2008, hospitals increased promotion activities and reported increases in vaccination rates. Based on the random-dialed surveys, HCP influenza vaccination coverage rates did not increase significantly. Vaccination rates were significantly higher in HCPs who reported that employers provided free vaccination and those who believed that their employers mandated influenza vaccination. This local public health initiative and concurrent state legislation were effective in increasing employer efforts to promote influenza vaccination; however, population-based surveys of HCPs did not show significant increases in influenza vaccination. Overall, this study suggests that public health leadership, intensive employer promotion activities, and state-required declinations alone were not sufficient to significantly increase HCP influenza vaccination. Policymakers and employers should consider mandates to achieve optimal influenza vaccination among HCPs. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Ontogenetic, gravity-dependent development of rat soleus muscle

NASA Technical Reports Server (NTRS)

Ohira, Y.; Tanaka, T.; Yoshinaga, T.; Kawano, F.; Nomura, T.; Nonaka, I.; Allen, D. L.; Roy, R. R.; Edgerton, V. R.

2001-01-01

We tested the hypothesis that rat soleus muscle fiber growth and changes in myosin phenotype during the postnatal, preweaning period would be largely independent of weight bearing. The hindlimbs of one group of pups were unloaded intermittently from postnatal day 4 to day 21: the pups were isolated from the dam for 5 h during unloading and returned for nursing for 1 h. Control pups were either maintained with the dam as normal or put on an alternating feeding schedule as described above. The enlargement of mass (approximately 3 times), increase in myonuclear number (approximately 1.6 times) and myonuclear domain (approximately 2.6 times), and transformation toward a slow fiber phenotype (from 56 to 70% fibers expressing type I myosin heavy chain) observed in controls were inhibited by hindlimb unloading. These properties were normalized to control levels or higher within 1 mo of reambulation beginning immediately after the unloading period. Therefore, chronic unloading essentially stopped the ontogenetic developmental processes of 1) net increase in DNA available for transcription, 2) increase in amount of cytoplasm sustained by that DNA pool, and 3) normal transition of myosin isoforms that occur in some fibers from birth to weaning. It is concluded that normal ontogenetic development of a postural muscle is highly dependent on the gravitational environment even during the early postnatal period, when full weight-bearing activity is not routine.

Endurance training in the spontaneously hypertensive rat: conversion of pathological into physiological cardiac hypertrophy.

PubMed

Garciarena, Carolina D; Pinilla, Oscar A; Nolly, Mariela B; Laguens, Ruben P; Escudero, Eduardo M; Cingolani, Horacio E; Ennis, Irene L

2009-04-01

The effect of endurance training (swimming 90 min/d for 5 days a week for 60 days) on cardiac hypertrophy was investigated in the spontaneously hypertensive rat (SHR). Sedentary SHRs (SHR-Cs) and normotensive Wistar rats were used as controls. Exercise training enhanced myocardial hypertrophy assessed by left ventricular weight/tibial length (228+/-7 versus 251+/-5 mg/cm in SHR-Cs and exercised SHRs [SHR-Es], respectively). Myocyte cross-sectional area increased approximately 40%, collagen volume fraction decreased approximately 50%, and capillary density increased approximately 45% in SHR-Es compared with SHR-Cs. The mRNA abundance of atrial natriuretic factor and myosin light chain 2 was decreased by the swimming routine (100+/-19% versus 41+/-10% and 100+/-8% versus 61+/-9% for atrial natriuretic factor and myosin light chain 2 in SHR-Cs and SHR-Es, respectively). The expression of sarcoplasmic reticulum Ca(2+) pump was significantly augmented, whereas that of Na(+)/Ca(2+) exchanger was unchanged (93+/-7% versus 167+/-8% and 158+/-13% versus 157+/-7%, sarcoplasmic reticulum Ca(2+) pump and Na(+)/Ca(2+) exchanger in SHR-Cs and SHR-Es, respectively; P<0.05). Endurance training inhibited apoptosis, as reflected by a decrease in caspase 3 activation and poly(ADP-ribose) polymerase-1 cleavage, and normalized calcineurin activity without inducing significant changes in the phosphatidylinositol 3-kinase/Akt pathway. The swimming routine improved midventricular shortening determined by echocardiography (32.4+/-0.9% versus 36.9+/-1.1% in SHR-Cs and SHR-Es, respectively; P<0.05) and decreased the left ventricular free wall thickness/left ventricular cavity radius toward an eccentric model of cardiac hypertrophy (0.59+/-0.02 versus 0.53+/-0.01 in SHR-Cs and SHR-Es, respectively; P<0.05). In conclusion, we present data demonstrating the effectiveness of endurance training to convert pathological into physiological hypertrophy improving cardiac performance. The reduction of myocardial fibrosis and calcineurin activity plus the increase in capillary density represent factors to be considered in determining this beneficial effect.

Experienced Mindfulness Meditators Exhibit Higher Parietal-Occipital EEG Gamma Activity during NREM Sleep

PubMed Central

Ferrarelli, Fabio; Smith, Richard; Dentico, Daniela; Riedner, Brady A.; Zennig, Corinna; Benca, Ruth M.; Lutz, Antoine; Davidson, Richard J.; Tononi, Giulio

2013-01-01

Over the past several years meditation practice has gained increasing attention as a non-pharmacological intervention to provide health related benefits, from promoting general wellness to alleviating the symptoms of a variety of medical conditions. However, the effects of meditation training on brain activity still need to be fully characterized. Sleep provides a unique approach to explore the meditation-related plastic changes in brain function. In this study we performed sleep high-density electroencephalographic (hdEEG) recordings in long-term meditators (LTM) of Buddhist meditation practices (approximately 8700 mean hours of life practice) and meditation naive individuals. We found that LTM had increased parietal-occipital EEG gamma power during NREM sleep. This increase was specific for the gamma range (25–40 Hz), was not related to the level of spontaneous arousal during NREM and was positively correlated with the length of lifetime daily meditation practice. Altogether, these findings indicate that meditation practice produces measurable changes in spontaneous brain activity, and suggest that EEG gamma activity during sleep represents a sensitive measure of the long-lasting, plastic effects of meditative training on brain function. PMID:24015304

The X-ray absorption spectrum of 4U1700-37 and its implications for the stellar wind of the companion HD153919

NASA Technical Reports Server (NTRS)

White, N. E.; Kallman, T. R.; Swank, J. H.

1982-01-01

The first high resolution non-dispersive 2-60 KeV X-ray spectra of 4U1700-37 is presented. The continuum is typical of that found from X-ray pulsars; that is a flat power law between 2 and 10 keV and, beyond 10 keV, an exponential decay of characteristic energy varying between 10 and 20 keV. No X-ray pulsations were detected between 160 ms and 6 min with an amplitude greater than approximately 2%. The absorption measured at binary phases approximately 0.72 is comparable to that expected from the stellar wind of the primary. The gravitational capture of material in the wind is found to be more than enough to power the X-ray source. The increase in the average absorption after phi o approximately 0.5 is confirmed. The minimum level of adsorption is a factor of 2 or 3 lower than that reported by previous observers, which may be related to a factor of approximately 10 decline in the average X-ray luminosity over the same interval. Short term approximately 50% variations in adsorption are seen for the first time which appear to be loosely correlated with approximately 10 min flickering activity in the X-ray flux. These most likely originate from inhomogeneities in the stellar wind of the primary.

Reduced peroxisomal citrate synthase activity increases substrate availability for polyhydroxyalkanoate biosynthesis in plant peroxisomes.

PubMed

Tilbrook, Kimberley; Poirier, Yves; Gebbie, Leigh; Schenk, Peer M; McQualter, Richard B; Brumbley, Stevens M

2014-10-01

Polyhydroxyalkanoates (PHAs) are bacterial carbon storage polymers used as renewable, biodegradable plastics. PHA production in plants may be a way to reduce industrial PHA production costs. We recently demonstrated a promising level of peroxisomal PHA production in the high biomass crop species sugarcane. However, further production strategies are needed to boost PHA accumulation closer to commercial targets. Through exogenous fatty acid feeding of Arabidopsis thaliana plants that contain peroxisome-targeted PhaA, PhaB and PhaC enzymes from Cupriavidus necator, we show here that the availability of substrates derived from the β-oxidation cycle limits peroxisomal polyhydroxybutyrate (PHB) biosynthesis. Knockdown of peroxisomal citrate synthase activity using artificial microRNA increased PHB production levels approximately threefold. This work demonstrates that reduction of peroxisomal citrate synthase activity may be a valid metabolic engineering strategy for increasing PHA production in other plant species. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Increased Preclass Preparation Underlies Student Outcome Improvement in the Flipped Classroom

PubMed Central

Gross, David; Pietri, Evava S.; Anderson, Gordon; Moyano-Camihort, Karin; Graham, Mark J.

2015-01-01

Active-learning environments such as those found in a flipped classroom are known to increase student performance, although how these gains are realized over the course of a semester is less well understood. In an upper-level lecture course designed primarily for biochemistry majors, we examine how students attain improved learning outcomes, as measured by exam scores, when the course is converted to a more active flipped format. The context is a physical chemistry course catering to life science majors in which approximately half of the lecture material is placed online and in-class problem-solving activities are increased, while total class time is reduced. We find that exam performance significantly improves by nearly 12% in the flipped-format course, due in part to students interacting with course material in a more timely and accurate manner. We also find that the positive effects of the flipped class are most pronounced for students with lower grade point averages and for female students. PMID:26396151

Changes in plasma enzyme activity after intramuscular injection of bupivacaine into the human biceps brachii.

PubMed

Nosaka, K; Sakamoto, K

1999-11-01

The purpose of this study was to examine the time course of changes in plasma creatine kinase (CK), lactate dehydrogenase (LDH), aspartate (AST) and alanine aminotransferase (ALT) activity after intramuscular injection of 0.5% bupivacaine (BPVC). A total of 10 mL BPVC was injected into the biceps brachii (two sites, 5 mL per site) of five healthy, male subjects. Blood samples were obtained from the antecubital vein before and 2, 4, 8, 12, 24, 48, 72 and 96 h after the injection. Affected muscle size was visualized using magnetic resonance imaging (MRI), which was performed 4 days after the injection. Plasma CK activity started to increase 2 h and peaked 12 h after the injection. The peak CK activity (470 +/- 62 IU L-1) was approximately four times the pre-injection value (133 +/- 24 IU L-1), and no additional increase was observed after 24 h. Plasma LDH, AST and ALT activities did not change significantly over time. Muscle around the injection sites showed increased T2 signal intensity using MRI. When smaller (2 mL) or larger (20 mL) amounts of BPVC were injected into the biceps brachii in additional experiments, the amount of increase in plasma CK activity appeared to be related to the size of the affected muscle. It was concluded that CK started to leak from damaged muscle cells shortly after the BPVC injection, and the amount of increase in plasma CK activity appeared to reflect the amount of muscle damage.

Short-term modulation of regional excitability and blood flow in human motor cortex following rapid-rate transcranial magnetic stimulation.

PubMed

Takano, Beatrice; Drzezga, Alexander; Peller, Martin; Sax, Iris; Schwaiger, Markus; Lee, Lucy; Siebner, Hartwig Roman

2004-11-01

Repetitive transcranial magnetic stimulation (rTMS) of the human primary motor cortex (M1) provides a means of inducing lasting changes in cortical excitability and synaptic activity. Here we combined rTMS with positron emission tomography of regional cerebral blood flow (rCBF) to examine how an rTMS-induced change in intracortical excitability of inhibitory circuits affects regional synaptic activity. In a first set of experiments, we gave 150 biphasic pulses of 5 Hz rTMS at 90% of active motor threshold to left M1 and used single- and paired-pulse TMS to assess the conditioning effects of rTMS on motor cortical excitability at rest. rTMS conditioning led to a selective decrease in short-latency intracortical inhibition (SICI) without affecting short-latency intracortical facilitation or corticospinal excitability. The decrease in SICI lasted for approximately 8 min. In a second experiment, we used the same rTMS protocol and measured changes in regional synaptic activity (as indexed by rCBF) during and for up to 14 min after the end of rTMS. Subthreshold 5 Hz rTMS induced a region-specific increase in resting rCBF in the stimulated M1 lasting approximately 8 min. These results suggest that in the stimulated M1, temporary attenuation of SICI is paralleled by an increase in synaptic activity, consistent with reduced efficacy of intracortical GABA(A)-ergic synapses. The present findings demonstrate that short trains of low-intensity 5 Hz rTMS can be used to induce a transient change in function within a distinct cortical area. This opens up new possibilities for studying acute reorganization at the systems level in the intact human brain.

EG-VEGF, BV8, and their receptor expression in human bronchi and their modification in cystic fibrosis: Impact of CFTR mutation (delF508).

PubMed

Chauvet, Sylvain; Traboulsi, Wael; Thevenon, Laura; Kouadri, Amal; Feige, Jean-Jacques; Camara, Boubou; Alfaidy, Nadia; Benharouga, Mohamed

2015-08-01

Enhanced lung angiogenesis has been reported in cystic fibrosis (CF). Recently, two highly homologous ligands, endocrine gland vascular endothelial growth factor (EG-VEGF) and mammalian Bv8, have been described as new angiogenic factors. Both ligands bind and activate two closely related G protein-coupled receptors, the prokineticin receptor (PROKR) 1 and 2. Yet, the expression, regulation, and potential role of EG-VEGF, BV8, and their receptors in normal and CF lung are still unknown. The expression of the receptors and their ligands was examined using molecular, biochemical, and immunocytochemistry analyses in lungs obtained from CF patients vs. control and in normal and CF bronchial epithelial cells. Cystic fibrosis transmembrane conductance regulator (CFTR) activity was evaluated in relation to both ligands, and concentrations of EG-VEGF were measured by ELISA. At the mRNA level, EG-VEGF, BV8, and PROKR2 gene expression was, respectively, approximately five, four, and two times higher in CF lungs compared with the controls. At the cellular level, both the ligands and their receptors showed elevated expressions in the CF condition. Similar results were observed at the protein level. The EG-VEGF secretion was apical and was approximately two times higher in CF compared with the normal epithelial cells. This secretion was increased following the inhibition of CFTR chloride channel activity. More importantly, EG-VEGF and BV8 increased the intracellular concentration of Ca(2+) and cAMP and stimulated CFTR-chloride channel activity. Altogether, these data suggest local roles for epithelial BV8 and EG-VEGF in the CF airway peribronchial vascular remodeling and highlighted the role of CFTR activity in both ligand biosynthesis and secretion. Copyright © 2015 the American Physiological Society.

Changes in left ventricular repolarization and ion channel currents following a transient rate increase superimposed on bradycardia in anesthetized dogs.

PubMed

Rubart, M; Lopshire, J C; Fineberg, N S; Zipes, D P

2000-06-01

We previously demonstrated in dogs that a transient rate increase superimposed on bradycardia causes prolongation of ventricular refractoriness that persists for hours after resumption of bradycardia. In this study, we examined changes in membrane currents that are associated with this phenomenon. The whole cell, patch clamp technique was used to record transmembrane voltages and currents, respectively, in single mid-myocardial left ventricular myocytes from dogs with 1 week of complete AV block; dogs either underwent 1 hour of left ventricular pacing at 120 beats/min or did not undergo pacing. Pacing significantly heightened mean phase 1 and peak plateau amplitudes by approximately 6 and approximately 3 mV, respectively (P < 0.02), and prolonged action potential duration at 90% repolarization from 235+/-8 msec to 278+/-8 msec (1 Hz; P = 0.02). Rapid pacing-induced changes in transmembrane ionic currents included (1) a more pronounced cumulative inactivation of the 4-aminopyridine-sensitive transient outward K+ current, Ito, over the range of physiologic frequencies, resulting from a approximately 30% decrease in the population of quickly reactivating channels; (2) increases in peak density of L-type Ca2+ currents, I(Ca.L), by 15% to 35 % between +10 and +60 mV; and (3) increases in peak density of the Ca2+-activated chloride current, I(Cl.Ca), by 30% to 120% between +30 and +50 mV. Frequency-dependent reduction in Ito combined with enhanced I(Ca.L) causes an increase in net inward current that may be responsible for the observed changes in ventricular repolarization. This augmentation of net cation influx is partially antagonized by an increase in outward I(Ca.Cl).

Trapping-mediated dissociative chemisorption of C3H8 and C3D8 on Ir(110)

NASA Astrophysics Data System (ADS)

Kelly, D.; Weinberg, W. H.

1996-07-01

We have employed molecular beam techniques to investigate the molecular trapping and trapping-mediated dissociative chemisorption of C3H8 and C3D8 on Ir(110) at low beam translational energies, Ei≤5 kcal/mol, and surface temperatures, Ts, from 85 to 1200 K. For Ts=85 K, C3H8 is molecularly adsorbed on Ir(110) with a trapping probability, ξ, equal to 0.94 at Ei=1.6 kcal/mol and ξ=0.86 at Ei=5 kcal/mol. At Ei=1.9 kcal/mol and Ts=85 K, ξ of C3D8 is equal to 0.93. From 150 K to approximately 700 K, the initial probabilities of dissociative chemisorption of propane decrease with increasing Ts. For Ts from 700 to 1200 K, however, the initial probability of dissociative chemisorption maintains the essentially constant value of 0.16. These observations are explained within the context of a kinetic model which includes both C-H (C-D) and C-C bond cleavage. Below 450 K propane chemisorption on Ir(110) arises essentially solely from C-H (C-D) bond cleavage, an unactivated mechanism (with respect to a gas-phase energy zero) for this system, which accounts for the decrease in initial probabilities of chemisorption with increasing Ts. With increasing Ts, however, C-C bond cleavage, the activation energy of which is greater than the desorption energy of physically adsorbed propane, increasingly contributes to the measured probability of dissociative chemisorption. The activation energies, referenced to the bottom of the physically adsorbed molecular well, for C-H and C-C bond cleavage for C3H8 on Ir(110) are found to be Er,CH=5.3±0.3 kcal/mol and Er,CC=9.9±0.6 kcal/mol, respectively. The activation energies for C-D and C-C bond cleavage for C3D8 on Ir(110) are 6.3±0.3 kcal/mol and 10.5±0.6 kcal/mol, respectively. The desorption activation energy of propane from Ir(110) is approximately 9.5 kcal/mol. These activation energies are compared to activation energies determined recently for ethane and propane adsorption on Ir(111), Ru(001), and Pt(110)-(1×2), and ethane activation on Ir(110).

Higher-order force moments of active particles

NASA Astrophysics Data System (ADS)

Nasouri, Babak; Elfring, Gwynn J.

2018-04-01

Active particles moving through fluids generate disturbance flows due to their activity. For simplicity, the induced flow field is often modeled by the leading terms in a far-field approximation of the Stokes equations, whose coefficients are the force, torque, and stresslet (zeroth- and first-order force moments) of the active particle. This level of approximation is quite useful, but may also fail to predict more complex behaviors that are observed experimentally. In this study, to provide a better approximation, we evaluate the contribution of the second-order force moments to the flow field and, by reciprocal theorem, present explicit formulas for the stresslet dipole, rotlet dipole, and potential dipole for an arbitrarily shaped active particle. As examples of this method, we derive modified Faxén laws for active spherical particles and resolve higher-order moments for active rod-like particles.

Rhenium Complexes and Clusters Supported on c-Al2O3: Effects of Rhenium Oxidation State and Rhenium Cluster Size on Catalytic Activity for n-butane Hydrogenolysis

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

Lobo Lapidus, R.; Gates, B

2009-01-01

Supported metals prepared from H{sub 3}Re{sub 3}(CO){sub 12} on {gamma}-Al{sub 2}O{sub 3} were treated under conditions that led to various rhenium structures on the support and were tested as catalysts for n-butane conversion in the presence of H{sub 2} in a flow reactor at 533 K and 1 atm. After use, two samples were characterized by X-ray absorption edge positions of approximately 5.6 eV (relative to rhenium metal), indicating that the rhenium was cationic and essentially in the same average oxidation state in each. But the Re-Re coordination numbers found by extended X-ray absorption fine structure spectroscopy (2.2 and 5.1)more » show that the clusters in the two samples were significantly different in average nuclearity despite their indistinguishable rhenium oxidation states. Spectra of a third sample after catalysis indicate approximately Re{sub 3} clusters, on average, and an edge position of 4.5 eV. Thus, two samples contained clusters approximated as Re{sub 3} (on the basis of the Re-Re coordination number), on average, with different average rhenium oxidation states. The data allow resolution of the effects of rhenium oxidation state and cluster size, both of which affect the catalytic activity; larger clusters and a greater degree of reduction lead to increased activity.« less

Biophysical characterization and functional consequences of a slowly inactivating potassium current in neostriatal neurons.

PubMed

Gabel, L A; Nisenbaum, E S

1998-04-01

Neostriatal spiny projection neurons can display a pronounced delay in their transition to action potential discharge that is mediated by a slowly developing ramp depolarization. The possible contribution of a slowly inactivating A-type K+ current (IAs) to this delayed excitation was investigated by studying the biophysical and functional properties of IAs using whole cell voltage- and current-clamp recording from acutely isolated neostriatal neurons. Isolation of IAs from other voltage-gated, calcium-independent K+ currents was achieved through selective blockade of IAs with low concentrations (10 microM) of the benzazepine derivative, 6-chloro-7,8-dihydroxy-3-allyl- 1-phenyl-2,3,4,5-tetra-hydro-1H-3-benzazepine (APB; SKF82958) and subsequent current subtraction. Examination of the voltage dependence of activation showed that IAs began to flow at approximately -60 mV in response to depolarization. The voltage dependence of inactivation revealed that approximately 50% of IAs channels were available at the normal resting potential (-80 mV) of these cells, but that only 20% of the channels were available at membrane potentials corresponding to spike threshold (about -40 mV). At these depolarized membrane potentials, the rate of activation was moderately rapid (tau approximately 60 ms), whereas the rate of inactivation was slow (tau approximately 1.5 s). The time course of removal of inactivation of IAs at -80 mV also was relatively slow (tau approximately 1.0 s). The subthreshold availability of IAs combined with its rapid activation and slow inactivation rates suggested that this current should be capable of dampening the onset of prolonged depolarizing responses, but over time its efficacy should diminish, slowly permitting the membrane to depolarize toward spike threshold. Voltage recording experiments confirmed this hypothesis by demonstrating that application of APB at a concentration (10 microM) that selectively blocks IAs substantially decreased the latency to discharge and increased the frequency of firing of neostriatal neurons. The properties of IAs suggest that it should play a critical role in placing the voltage limits on the recurring episodes of subthreshold depolarization which are characteristic of spiny neurons recorded in vivo. However, the voltage dependence and recovery kinetics of inactivation of IAs predict that its effectiveness will vary exponentially with the level and duration of hyperpolarization which precedes depolarizing episodes. Thus long periods of hyperpolarization should increase the availability of IAs and dampen succeeding depolarizations; whereas brief epochs of hyperpolarization should not sufficiently remove inactivation of IAs, thereby reducing its ability to limit subsequent depolarizing responses.

Thrombin-stimulated platelet aggregation is inhibited by kallikrein in a time- and concentration-dependent manner.

PubMed

Veloso, D

2003-01-01

Many in vitro studies have shown that activation of prekallikrein (PK) to kallikrein (KAL) in normal plasma triggers rapid activation of the coagulation cascade. In agreement, the coagulation activation is impaired in PK-deficient plasma. Paradoxically, PK-deficient patients show a tendency to thrombosis. To investigate the discrepancy between the in vitro and in vivo findings, we analyzed the effect of KAL on the rate of platelet aggregation. For this research, physiologic concentrations of washed human platelets were incubated for 5 and/or 10 min with approximately 2.2 to 88 nM human plasma KAL (< 1/100 to approximately 1/3 of PK concentrations in plasma) prior to the addition of high concentrations of alpha-thrombin (54 nM) or fibrinogen plus ADP. KAL concentrations were arbitrarily selected on the assumption that concentrations of free KAL (the enzymatically active species) were minute in normal plasma and higher when KAL production was enhanced, and/or inhibitors were depleted. Full platelet aggregation was that seen in the absence of KAL or PK. Inhibition of platelet aggregation stimulated by thrombin was markedly increased with increased KAL concentrations and incubation times. The degree of inhibition by KAL was smaller when ADP was the agonist. The data suggest that KAL may play a role in the modulation of platelet aggregation in vivo under normal conditions as well as when prolonged, high concentrations of KAL occur in blood. The data may also help to explain the intriguing observation that PK-deficient patients show a tendency to thrombotic episodes and myocardial infarction whereas in vitro assays predict bleeding.

Fabrication and high temperature characteristics of ion-implanted GaAs bipolar transistors and ring-oscillators

NASA Technical Reports Server (NTRS)

Doerbeck, F. H.; Yuan, H. T.; Mclevige, W. V.

1981-01-01

Ion implantation techniques that permit the reproducible fabrication of bipolar GaAs integrated circuits are studied. A 15 stage ring oscillator and discrete transistor were characterized between 25 and 400 C. The current gain of the transistor was found to increase slightly with temperature. The diode leakage currents increase with an activation energy of approximately 1 eV and dominate the transistor leakage current 1 sub CEO above 200 C. Present devices fail catastrophically at about 400 C because of Au-metallization.

Increasing resistance against Phytophthora citrophthora in tangelo Nova fruits by modulating polymethoxyflavones levels.

PubMed

Ortuño, A; Arcas, M C; Botía, J M; Fuster, M D; Del Río, J A

2002-05-08

The effect of 6-benzylaminopurine on polymethoxyflavone levels in tangelo Nova fruits and the possible participation of these secondary metabolites in defense mechanisms against Phytophthora citrophthora are studied. The in vitro study of the inhibitory effect of these compounds on fungal growth reveals that nobiletin is the most active agent followed by sinensetin, heptamethoxyflavone, and tangeretin. Treatment with 100 ppm of 6-benzylaminopurine increased the levels of these polymethoxyflavones in this Citrus hybrid and also enhanced the in vivo resistance of the fruit to the fungus by approximately 60%.

Effective equilibrium states in the colored-noise model for active matter I. Pairwise forces in the Fox and unified colored noise approximations

NASA Astrophysics Data System (ADS)

Wittmann, René; Maggi, C.; Sharma, A.; Scacchi, A.; Brader, J. M.; Marini Bettolo Marconi, U.

2017-11-01

The equations of motion of active systems can be modeled in terms of Ornstein-Uhlenbeck processes (OUPs) with appropriate correlators. For further theoretical studies, these should be approximated to yield a Markovian picture for the dynamics and a simplified steady-state condition. We perform a comparative study of the unified colored noise approximation (UCNA) and the approximation scheme by Fox recently employed within this context. We review the approximations necessary to define effective interaction potentials in the low-density limit and study the conditions for which these represent the behavior observed in two-body simulations for the OUPs model and active Brownian particles. The demonstrated limitations of the theory for potentials with a negative slope or curvature can be qualitatively corrected by a new empirical modification. In general, we find that in the presence of translational white noise the Fox approach is more accurate. Finally, we examine an alternative way to define a force-balance condition in the limit of small activity.

A Phase-Locked Loop Epilepsy Network Emulator

PubMed Central

Watson, P.D.; Horecka, K. M.; Cohen, N.J.; Ratnam, R.

2015-01-01

Most seizure forecasting employs statistical learning techniques that lack a representation of the network interactions that give rise to seizures. We present an epilepsy network emulator (ENE) that uses a network of interconnected phase-locked loops (PLLs) to model synchronous, circuit-level oscillations between electrocorticography (ECoG) electrodes. Using ECoG data from a canine-epilepsy model (Davis et al. 2011) and a physiological entropy measure (approximate entropy or ApEn, Pincus 1995), we demonstrate the entropy of the emulator phases increases dramatically during ictal periods across all ECoG recording sites and across all animals in the sample. Further, this increase precedes the observable voltage spikes that characterize seizure activity in the ECoG data. These results suggest that the ENE is sensitive to phase-domain information in the neural circuits measured by ECoG and that an increase in the entropy of this measure coincides with increasing likelihood of seizure activity. Understanding this unpredictable phase-domain electrical activity present in ECoG recordings may provide a target for seizure detection and feedback control. PMID:26664133

Acrolein increases airway sensitivity to substance P and decreases NEP activity in guinea pigs.

PubMed

Turner, C R; Stow, R B; Hubbs, S J; Gomes, B C; Williams, J C

1993-04-01

The effects of acrolein exposure on airway responses to intravenous substance P were determined in guinea pigs exposed to vehicle or 1.6 ppm acrolein for 7.5 h on 2 consecutive days and examined 1, 4, 8, 15, and 28 days after exposure by use of pulmonary mechanics and bronchoalveolar lavage (BAL). Lung, trachea, liver, and BAL fluid were also assayed for neutral endopeptidase (NEP) activity 1, 7, and 28 days after exposure. Pulmonary inflammation and epithelial damage were prominent 1 day after acrolein exposure. NEP activity was decreased in the lungs, trachea, and liver 1 and 7 days after acrolein. Twenty-eight days after exposure, NEP activity in the lungs and liver was not significantly different in vehicle- and acrolein-exposed guinea pigs but was still reduced in tracheal tissue. The BAL NEP activity in acrolein-exposed guinea pigs was approximately twice that of vehicle control guinea pigs at all three time points. Acrolein caused a prolonged increase in airway sensitivity to substance P. Experiments performed in the presence of thiorphan suggested that the acrolein-induced reduction in NEP may contribute to increased airway sensitivity to aerosolized substance P, but the increase in airway sensitivity to intravenous substance P may occur by additional mechanisms.

Disseminating Evidence-Based Physical Education Practices in Rural Schools: The San Luis Valley Physical Education Academy.

PubMed

Belansky, Elaine S; Cutforth, Nick; Kern, Ben; Scarbro, Sharon

2016-09-01

To address childhood obesity, strategies are needed to maximize physical activity during the school day. The San Luis Valley Physical Education Academy was a public health intervention designed to increase the quality of physical education and quantity of moderate to vigorous physical activity (MVPA) during physical education class. Elementary school physical education teachers from 17 schools participated in the intervention. They received SPARK curriculum and equipment, workshops, and site coordinator support for 2 years. A pre/post/post within physical education teacher design was used to measure intervention effectiveness. System for Observing Fitness Instruction Time (SOFIT) and a physical education teacher survey were collected 3 times. MVPA increased from 51.1% to 67.3% over the 2-year intervention resulting in approximately 14.6 additional hours of physical activity over a school year and 4662 kcal or 1.33 lbs. of weight gain prevention. More time was spent on skill drills and less time on classroom management and free play. The San Luis Valley Physical Education Academy succeeded in increasing rural, low-income students' physical activity. The multicomponent intervention contributed to the program's success. However, cost-effective approaches are needed to disseminate and implement evidencebased practices aimed at increasing students' physical activity during the school day.

Comparative behavioral pharmacology and toxicology of cocaine and its ethanol-derived metabolite, cocaine ethyl-ester (cocaethylene)

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

Katz, J.L.; Terry, P.; Witkin, J.M.

The present study compared the behavioral and toxic effects of cocaine and its ethanol derived metabolite, cocaine ethyl-ester (cocaethylene). Both drugs produced qualitatively similar psychomoter stimulant effects. Cocaine and cocaethylene increased locomotor activity in mice, with cocaine approximately four times more potent than cocaethylene. The durations of action of ED{sub 75} doses of each of the drugs were comparable. Each of the drugs also produced stimulation of operant responding in rats. In rats and squirrel monkeys trained to discriminate cocaine injections from saline, cocaine was approximately three to five times more potent than cocaethylene in producing these cocaine-like interoceptive effects.more » In contrast to the behavioral effects, cocaine and cocaethylene were equipotent in producing convulsions, and cocaethylene was more potent than cocaine in producing lethality. These results suggest that the conversion of cocaine to cocaethylene with simultaneous cocaine and alcohol use may produce an increased risk of toxicity due to a decrease in the potency of cocaethylene in producing psychomotor stimulant effects, and its increased potency in producing toxicity.« less

Calcium metabolism before, during, and after a 3-mo spaceflight: kinetic and biochemical changes

NASA Technical Reports Server (NTRS)

Smith, S. M.; Wastney, M. E.; Morukov, B. V.; Larina, I. M.; Nyquist, L. E.; Abrams, S. A.; Taran, E. N.; Shih, C. Y.; Nillen, J. L.; Davis-Street, J. E.;

Influence of environmental factors on denitrification in sediment contaminated with JP-4 jet fuel

USGS Publications Warehouse

Bradley, Paul M.; Aelion, C. Marjorie; Vroblesky, Don A.

1992-01-01

In 1975, the loss of approximately 83,000 gallons of JP-4 grade jet fuel resulted in contamination of the shallow aquifer near North Charleston, South Carolina. To identify those factors likely to influence microbial activity under denitrifying conditions, we examined the fate of amended NO3, the effect of pH, NO3, and PO4 on denitrification, and the variability of denitrification in sediments collected at the site. Denitrification (N2O-N production) accounted for 98% of the depletion of NO3-N under anaerobic conditions. Both carbon mineralization and denitrification rates increased asymptotically with increasing NO3 to a maximum at approximately 1 mM NO3. Addition of up to 1 mM PO4 did not significantly increase N2O and CO2 production. Denitrification rates were at least 38% lower at pH = 4 than observed at pH = 7. Comparison of samples with differing degrees of hydrocarbon contamination indicated that at least a tenfold variation in sediment denitrification occurs at the North Charleston site.

Stronger Neural Modulation by Visual Motion Intensity in Autism Spectrum Disorders

PubMed Central

Peiker, Ina; Schneider, Till R.; Milne, Elizabeth; Schöttle, Daniel; Vogeley, Kai; Münchau, Alexander; Schunke, Odette; Siegel, Markus; Engel, Andreas K.; David, Nicole

2015-01-01

Theories of autism spectrum disorders (ASD) have focused on altered perceptual integration of sensory features as a possible core deficit. Yet, there is little understanding of the neuronal processing of elementary sensory features in ASD. For typically developed individuals, we previously established a direct link between frequency-specific neural activity and the intensity of a specific sensory feature: Gamma-band activity in the visual cortex increased approximately linearly with the strength of visual motion. Using magnetoencephalography (MEG), we investigated whether in individuals with ASD neural activity reflect the coherence, and thus intensity, of visual motion in a similar fashion. Thirteen adult participants with ASD and 14 control participants performed a motion direction discrimination task with increasing levels of motion coherence. A polynomial regression analysis revealed that gamma-band power increased significantly stronger with motion coherence in ASD compared to controls, suggesting excessive visual activation with increasing stimulus intensity originating from motion-responsive visual areas V3, V6 and hMT/V5. Enhanced neural responses with increasing stimulus intensity suggest an enhanced response gain in ASD. Response gain is controlled by excitatory-inhibitory interactions, which also drive high-frequency oscillations in the gamma-band. Thus, our data suggest that a disturbed excitatory-inhibitory balance underlies enhanced neural responses to coherent motion in ASD. PMID:26147342

Maturation of language networks in children: A systematic review of 22years of functional MRI.

PubMed

Weiss-Croft, Louise J; Baldeweg, Torsten

2015-12-01

Understanding how language networks change during childhood is important for theories of cognitive development and for identifying the neural causes of language impairment. Despite this, there is currently little systematic evidence regarding the typical developmental trajectory for language from the field of neuroimaging. We reviewed functional MRI (fMRI) studies published between 1992 and 2014, and quantified the evidence for age-related changes in localisation and lateralisation of fMRI activation in the language network (excluding the cerebellum and subcortical regions). Although age-related changes differed according to task type and input modality, we identified four consistent findings concerning the typical maturation of the language system. First, activation in core semantic processing regions increases with age. Second, activation in lower-level sensory and motor regions increases with age as activation in higher-level control regions reduces. We suggest that this reflects increased automaticity of language processing as children become more proficient. Third, the posterior cingulate cortex and precuneus (regions associated with the default mode network) show increasing attenuation across childhood and adolescence. Finally, language lateralisation is established by approximately 5years of age. Small increases in leftward lateralisation are observed in frontal regions, but these are tightly linked to performance. Copyright © 2015 Elsevier Inc. All rights reserved.

Carbohydrate feeding during recovery alters the skeletal muscle metabolic response to repeated sessions of high-intensity interval exercise in humans.

PubMed

Cochran, Andrew J R; Little, Jonathan P; Tarnopolsky, Mark A; Gibala, Martin J

2010-03-01

Exercise training under conditions of reduced carbohydrate (CHO) availability has been reported to augment gains in skeletal muscle oxidative capacity; however, the underlying mechanisms are unclear. We examined the effect of manipulating CHO intake on the acute metabolic response to high-intensity interval exercise, including signaling cascades linked to mitochondrial biogenesis. Ten men performed two trials in random order separated by >or=1 wk. Each trial consisted of a morning (AM) and afternoon (PM) training session (5 x 4 min cycling at approximately 90-95% of heart rate reserve) separated by 3 h of recovery during which subjects ingested a high-CHO drink (HI-HI) or nonenergetic placebo (HI-LO) before PM exercise. Biopsies (vastus lateralis) revealed that muscle phosphocreatine and ATP content were similar after AM exercise but decreased to a greater extent during PM exercise in HI-LO vs. HI-HI. Phosphorylation of p38 mitogen-activated protein kinase (MAPK) and AMP-activated protein kinase (AMPK) increased approximately 4-fold and 2-fold, respectively, during AM exercise with no difference between conditions. After PM exercise, p38 MAPK phosphorylation was higher in HI-LO vs. HI-HI, whereas AMPK was not different between conditions. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 alpha) gene expression increased approximately 8-fold during recovery from AM exercise and remained elevated during PM exercise with no differences between conditions. Cytochrome oxidase subunit 4 (COXIV) mRNA was also elevated 3 h after AM exercise, with no difference between conditions. These data provide evidence that p38 MAPK is a nutrient-sensitive signaling molecule that could be involved in the altered skeletal muscle adaptive response reported after exercise training under conditions of restricted CHO intake, but further research is required to confirm this hypothesis.

Spatially uniform and nonuniform analyses of electroencephalographic dynamics,with application to the topography of the alpha rhythm

NASA Astrophysics Data System (ADS)

O'Connor, S. C.; Robinson, P. A.

2004-07-01

Corticothalamic dynamics are investigated using a model in which spatial nonuniformities are incorporated via the coupling of spatial eigenmodes. Comparison of spectra generated using the nonuniform analysis with those generated using a uniform one demonstrates that, for most frequencies, local activity is only weakly dependent on activity elsewhere in the cortex; however, dispersion of low-wave-number activity ensures that distant dynamics influence local dynamics at low frequencies (below approximately 2Hz ), and at the alpha frequency (approximately 10Hz ), where propagating signals are inherently weakly damped, and wavelengths are large. When certain model parameters have similar spatial profiles, as is expected from physiology, the low-frequency discrepancies tend to cancel, and the uniform analysis with local parameter values is an adequate approximation to the full nonuniform one across the whole spectrum, at least for large-scale nonuniformities. After comparing the uniform and nonuniform analyses, we consider one possible application of the nonuniform analysis: studying the phenomenon of occipital alpha dominance, whereby the alpha frequency and power are greater at the back of the head (occipitally) than at the front. In order to infer realistic nonuniformities in the model parameters, the uniform version of the model is first fitted to data recorded from 98 normal subjects in a waking, eyes-closed state. This yields a set of parameters at each of five electrode sites along the midline. The inferred parameter nonuniformities are consistent with anatomical and physiological constraints. Introducing these spatial profiles into the full nonuniform model then quantitatively reproduces observed site-dependent variations in the alpha power and frequency. The results confirm that the frequency shift is mainly due to a decrease in the corticothalamic propagation delay, but indicate that the delay nonuniformity cannot account for the observed occipital increase in alpha power; the occipital alpha dominance is due to decreased cortical gains and increased thalamic gains in occipital regions compared to frontal ones.

Multiple, novel biologically active endophytic actinomycetes isolated from upper Amazonian rainforests.

PubMed

Bascom-Slack, Carol A; Ma, Cong; Moore, Emily; Babbs, Beatrice; Fenn, Kathleen; Greene, Joshua S; Hann, Bradley D; Keehner, Jocelyn; Kelley-Swift, Elizabeth G; Kembaiyan, Vivek; Lee, Sun Jin; Li, Puyao; Light, David Y; Lin, Emily H; Schorn, Michelle A; Vekhter, Daniel; Boulanger, Lori-Ann; Hess, W M; Vargas, Percy Núñez; Strobel, Gary A; Strobel, Scott A

2009-08-01

Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants.

Long-term increases in tropical flowering activity across growth forms in response to rising CO2 and climate change.

PubMed

Pau, Stephanie; Okamoto, Daniel K; Calderón, Osvaldo; Wright, S Joseph

2018-05-01

Mounting evidence suggests that anthropogenic global change is altering plant species composition in tropical forests. Fewer studies, however, have focused on long-term trends in reproductive activity, in part because of the lack of data from tropical sites. Here, we analyze a 28-year record of tropical flower phenology in response to anthropogenic climate and atmospheric change. We show that a multidecadal increase in flower activity is most strongly associated with rising atmospheric CO 2 concentrations using yearly aggregated data. Compared to significant climatic factors, CO 2 had on average an approximately three-, four-, or fivefold stronger effect than rainfall, solar radiation, and the Multivariate ENSO Index, respectively. Peaks in flower activity were associated with greater solar radiation and lower rainfall during El Niño years. The effect of atmospheric CO 2 on flowering has diminished over the most recent decade for lianas and canopy trees, whereas flowering of midstory trees and shrub species continued to increase with rising CO 2 . Increases in flowering were accompanied by a lengthening of flowering duration for canopy and midstory trees. Understory treelets did not show increases in flowering but did show increases in duration. Given that atmospheric CO 2 will likely continue to climb over the next century, a long-term increase in flowering activity may persist in some growth forms until checked by nutrient limitation or by climate change through rising temperatures, increasing drought frequency and/or increasing cloudiness and reduced insolation. © 2017 John Wiley & Sons Ltd.

Sorption of triclosan onto activated carbon, kaolinite and montmorillonite: effects of pH, ionic strength, and humic acid.

PubMed

Behera, Shishir Kumar; Oh, Seok-Young; Park, Hung-Suck

2010-07-15

Sorption of triclosan on three sorbents, viz., activated carbon, kaolinite and montmorillonite was studied as a function of pH, ionic strength and humic acid (HA) concentration through controlled batch experiments. Triclosan sorption was found to be higher in the acidic pH range, as varying pH showed significant influence on the surface charge of the sorbents and degree of ionization of the sorbate. Sorption capacity of the sorbents increased with an increase in the ionic strength of solution. At low pH (pH 3), the overall increase in triclosan sorption was 1.2, approximately 4 and 3.5 times, respectively for activated carbon, kaolinite and montmorillonite when ionic strength was increased from 1x10(-3) to 5x10(-1) M. Triclosan sorption onto activated carbon decreased from 31.4 to 10.6 mg g(-1) by increasing the HA concentration to 200 mg C L(-1). However, during sorption onto kaolinite and montmorillonite, the effect of HA was very complex probably due to (i) hydrophobicity (log K(ow)=4.76) of triclosan; and (ii) complexation of HA with triclosan. Though triclosan sorption onto activated carbon is higher, the potential of kaolinite and montmorillonite in controlling the transport of triclosan in subsurface environment can still be appreciable. 2010 Elsevier B.V. All rights reserved.

Cationic lipids: molecular structure/ transfection activity relationships and interactions with biomembranes.

PubMed

Koynova, Rumiana; Tenchov, Boris

2010-01-01

Abstract Synthetic cationic lipids, which form complexes (lipoplexes) with polyanionic DNA, are presently the most widely used constituents of nonviral gene carriers. A large number of cationic amphiphiles have been synthesized and tested in transfection studies. However, due to the complexity of the transfection pathway, no general schemes have emerged for correlating the cationic lipid chemistry with their transfection efficacy and the approaches for optimizing their molecular structures are still largely empirical. Here we summarize data on the relationships between transfection activity and cationic lipid molecular structure and demonstrate that the transfection activity depends in a systematic way on the lipid hydrocarbon chain structure. A number of examples, including a large series of cationic phosphatidylcholine derivatives, show that optimum transfection is displayed by lipids with chain length of approximately 14 carbon atoms and that the transfection efficiency strongly increases with increase of chain unsaturation, specifically upon replacement of saturated with monounsaturated chains.

Protective effects of radon inhalation on carrageenan-induced inflammatory paw edema in mice.

PubMed

Kataoka, Takahiro; Teraoka, Junichi; Sakoda, Akihiro; Nishiyama, Yuichi; Yamato, Keiko; Monden, Mayuko; Ishimori, Yuu; Nomura, Takaharu; Taguchi, Takehito; Yamaoka, Kiyonori

2012-04-01

We assessed whether radon inhalation inhibited carrageenan-induced inflammation in mice. Carrageenan (1% v/v) was injected subcutaneously into paws of mice that had or had not inhaled approximately 2,000 Bq/m(3) of radon for 24 h. Radon inhalation significantly increased superoxide dismutase (SOD) and catalase activities and significantly decreased lipid peroxide levels in mouse paws, indicating that radon inhalation activates antioxidative functions. Carrageenan administration induced paw edema and significantly increased tumor necrosis factor-alpha (TNF-α) and nitric oxide in serum. However, radon inhalation significantly reduced carrageenan-induced paw edema. Serum TNF-α levels were lower in the radon-treated mice than in sham-treated mice. In addition, SOD and catalase activities in paws were significantly higher in the radon-treated mice than in the sham-treated mice. These findings indicated that radon inhalation had anti-inflammatory effects and inhibited carrageenan-induced inflammatory paw edema.

Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean.

PubMed

Romera-Castillo, Cristina; Pinto, Maria; Langer, Teresa M; Álvarez-Salgado, Xosé Antón; Herndl, Gerhard J

2018-04-12

Approximately 5.25 trillion plastic pieces are floating at the sea surface. The impact of plastic pollution on the lowest trophic levels of the food web, however, remains unknown. Here we show that plastics release dissolved organic carbon (DOC) into the ambient seawater stimulating the activity of heterotrophic microbes. Our estimates indicate that globally up to 23,600 metric tons of DOC are leaching from marine plastics annually. About 60% of it is available to microbial utilization in less than 5 days. If exposed to solar radiation, however, this DOC becomes less labile. Thus, plastic pollution of marine surface waters likely alters the composition and activity of the base of the marine food webs. It is predicted that plastic waste entering the ocean will increase by a factor of ten within the next decade, resulting in an increase in plastic-derived DOC that might have unaccounted consequences for marine microbes and for the ocean system.

Is access to workplace amenities associated with leisure-time physical activity among Canadian adults?

PubMed

Watts, Allison W; Masse, Louise C

2012-11-08

The workplace represents an important setting for increasing physical activity levels. The purpose of the present study was to investigate the relationship between the workplace environment and leisure-time physical activity, using a nationally representative sample of the Canadian population. This study used cross-sectional, self-reported data from 48,916 participants who completed relevant questions on the 2008 Canadian Community Health Survey. Associations between supportive workplace environments for physical activity (e.g., perceived range of amenities available such as a pleasant place to walk, fitness facility, showers, and health program) and leisure-time physical activity level (active, moderately active, inactive) were examined using multinomial logistic regression. Approximately three quarters (n=36,216) of participants had access to at least one amenity that supported physical activity while at work. Females in the lowest age category (18-35 years) who perceived a more supportive workplace environment for physical activity had higher odds of being moderately active (AOR 1.06, 95% CI 1.04-1.08) and active (AOR 1.15, 95% CI 1.13-1.17) as compared to inactive in their leisure time. The strength of this association was slightly higher with age and for males. Since the majority of Canadian adults do not meet recommended levels of physical activity, the workplace offers a promising and modifiable target for increasing opportunities to be physically active. Employers who can provide a more supportive workplace environment for physical activity would benefit, as it can increase employees' physical activity levels and ultimately improve their productivity and overall health. These benefits may be increased for males and with employees' age.

Anticoagulant activity of marine green and brown algae collected from Jeju Island in Korea.

PubMed

Athukorala, Yasantha; Lee, Ki-Wan; Kim, Se-Kwon; Jeon, You-Jin

2007-07-01

Twenty-two algal species were evaluated for their potential anticoagulant activities. Hot water extracts from selected species, Codium fragile and Sargassum horneri showed high activated partial thromboplastin time (APTT). Ultraflo extract of C. fragile and S. horneri exhibited the most potent anticoagulant activity. Furthermore, in both algal species, active compounds were mainly concentrated in >30kDa faction. The crude polysaccharide fraction (>30kDa; CpoF) of C. fragile composed of approximately 80% carbohydrate and approximately 19% of protein; the crude polysaccharide fraction (>30kDa; CpoF) of S. horneri was composed of 97% of carbohydrate and approximately 2% of protein. Therefore, most probably the active compound, or compounds of the algal species were related to high molecular weight polysaccharide, or a complex form with carbohydrate and protein (proteoglycan).

Induction of rat liver microsomal epoxide hydrolase by thiazole and pyrazine: hydrolysis of 2-cyanoethylene oxide.

PubMed

Kim, S G; Kedderis, G L; Batra, R; Novak, R F

1993-08-01

Liver microsomal epoxide hydrolase (mEH) is active in the detoxification of epoxide-containing carcinogens. The effects of thiazole and pyrazine, constituents of tobacco and tobacco smoke as well as of a variety of foods, on the expression and regulation of mEH were examined in rats (200 mg/kg body wt/day, i.p., 1-3 days). Immunoblot analyses using rabbit anti-rat mEH antibody revealed a significant increase in mEH levels in hepatic microsomes isolated from either thiazole- or pyrazine-treated animals. Another protein (approximately 43 kd) cross-reacting with polyclonal mEH antibody was found to be increased concomitantly following pyrazine treatment. Northern and slot blot analyses showed substantial increases in mEH mRNA following either thiazole or pyrazine treatment. The level of mEH mRNA increased 17-fold at 24 h following thiazole treatment, relative to control. Approximately 20- and 16-fold increases in mEH mRNA were also observed at 48 and 72 h respectively following treatment with pyrazine. The level of polymerase chain reaction (PCR)-amplified mEH DNA derived from poly(A)+ RNA was clearly elevated following either thiazole or pyrazine treatment relative to that from untreated animals. Both sense and antisense strands of PCR-amplified mEH DNA were cloned into an M13mp19 phage vector in order to examine the nucleotide sequences of PCR-amplified mEH DNA derived from the poly(A)+ RNA isolated from thiazole- or pyrazine-treated animals. Sequence analyses revealed that the sequence of PCR-amplified DNA from the induced mRNA was identical to that published for mEH cDNA. Epoxide hydrolase activity toward the hydrolysis of 2-cyanoethylene oxide (CEO), the epoxide metabolite of the rat carcinogen acrylonitrile, was not significant in hepatic microsomes from untreated rats, but was substantially induced by treatment with thiazole or pyrazine. Microsomal hydrolysis activity was heat-sensitive and potently inhibited by 1,1,1-trichloropropene-2,3-oxide, indicating that mEH was the catalyst. The Vmax for the hydrolysis of CEO by hepatic microsomes from thiazole-treated rats (13.4 nmol/min/mg protein) was 1.5-fold greater than that with microsomes from pyrazine-treated rats, whereas similar Km values (approximately 1 mM) were observed for both microsomal preparations. These kinetic data correlate well with the increases in mEH mRNA observed after administration of thiazole or pyrazine to rats. These results provide evidence that administration of thiazole or pyrazine induces mEH with a large increase in mEH mRNA, and that the induced mEH catalyzes the hydrolysis of CEO.

Habitual physical activity and the risk for depressive and anxiety disorders among older men and women.

PubMed

Pasco, Julie A; Williams, Lana J; Jacka, Felice N; Henry, Margaret J; Coulson, Carolyn E; Brennan, Sharon L; Leslie, Eva; Nicholson, Geoffrey C; Kotowicz, Mark A; Berk, Michael

2011-03-01

Regular physical activity is generally associated with psychological well-being, although there are relatively few prospective studies in older adults. We investigated habitual physical activity as a risk factor for de novo depressive and anxiety disorders in older men and women from the general population. In this nested case-control study, subjects aged 60 years or more were identified from randomly selected cohorts being followed prospectively in the Geelong Osteoporosis Study. Cases were individuals with incident depressive or anxiety disorders, diagnosed using the Structured Clinical Interview for DSM-IV-TR (SCID-I/NP); controls had no history of these disorders. Habitual physical activity, measured using a validated questionnaire, and other exposures were documented at baseline, approximately four years prior to psychiatric interviews. Those with depressive or anxiety disorders that pre-dated baseline were excluded. Of 547 eligible subjects, 14 developed de novo depressive or anxiety disorders and were classified as cases; 533 controls remained free of disease. Physical activity was protective against the likelihood of depressive and anxiety disorders; OR = 0.55 (95% CI 0.32-0.94), p = 0.03; each standard deviation increase in the transformed physical activity score was associated with an approximate halving in the likelihood of developing depressive or anxiety disorders. Leisure-time physical activity contributed substantially to the overall physical activity score. Age, gender, smoking, alcohol consumption, weight and socioeconomic status did not substantially confound the association. This study provides evidence consistent with the notion that higher levels of habitual physical activity are protective against the subsequent risk of development of de novo depressive and anxiety disorders.

Antioxidant Defenses against Activated Oxygen in Pea Nodules Subjected to Water Stress.

PubMed Central

Gogorcena, Y.; Iturbe-Ormaetxe, I.; Escuredo, P. R.; Becana, M.

1995-01-01

The involvement of activated oxygen in the drought-induced damage of pea (Pisum sativum L. cv Frilene) nodules was examined. To this purpose, various pro-oxidant factors, antioxidant enzymes and related metabolites, and markers of oxidative damage were determined in nodules of well-watered (nodule water potential approximately -0.29 MPa) and water-stressed (nodule water potential approximately -2.03 MPa) plants. Water-stressed nodules entered senescence as evidenced by the 30% decrease in leghemoglobin and total soluble protein. Drought also caused a decrease in the activities of catalase (25%), ascorbate peroxidase (18%), dehydroascorbate reductase (15%), glutathione reductase (31%), and superoxide dismutase (30%), and in the contents of ascorbate (59%), reduced (57%) and oxidized (38%) glutathione, NAD+ and NADH (43%), NADP+ (31%), and NADPH (17%). The decline in the antioxidant capacity of nodules may result from a restricted supply of NAD(P)H in vivo for the ascorbate-glutathione pathway and from the Fe-catalyzed Fenton reactions of ascorbate and glutathione with activated oxygen. The 2-fold increase in the content of "catalytic Fe" would also explain the augmented levels of lipid peroxides (2.4-fold) and oxidatively modified proteins (1.4-fold) found in water-stressed nodules because of the known requirement of lipid and protein oxidation for a transition catalytic metal. PMID:12228507

An Automatic User-Adapted Physical Activity Classification Method Using Smartphones.

PubMed

Li, Pengfei; Wang, Yu; Tian, Yu; Zhou, Tian-Shu; Li, Jing-Song

2017-03-01

In recent years, an increasing number of people have become concerned about their health. Most chronic diseases are related to lifestyle, and daily activity records can be used as an important indicator of health. Specifically, using advanced technology to automatically monitor actual activities can effectively prevent and manage chronic diseases. The data used in this paper were obtained from acceleration sensors and gyroscopes integrated in smartphones. We designed an efficient Adaboost-Stump running on a smartphone to classify five common activities: cycling, running, sitting, standing, and walking and achieved a satisfactory classification accuracy of 98%. We designed an online learning method, and the classification model requires continuous training with actual data. The parameters in the model then become increasingly fitted to the specific user, which allows the classification accuracy to reach 95% under different use environments. In addition, this paper also utilized the OpenCL framework to design the program in parallel. This process can enhance the computing efficiency approximately ninefold.

Comfort-oriented vehicle suspension design with skyhook inerter configuration

NASA Astrophysics Data System (ADS)

Hu, Yinlong; Chen, Michael Z. Q.; Sun, Yonghui

2017-09-01

This paper is concerned with the comfort-oriented vehicle suspension design problem by using a skyhook inerter configuration. The rationale of the skyhook inerter is to use a grounded inerter to virtually increase the sprung mass of a vehicle, as it is analytically demonstrated that increasing the sprung mass can always improve the ride comfort performance. Semi-active means to realize the skyhook inerter configuration are investigated by using semi-active inerters. Three control laws, that is the on-off control, the anti-chatter on-off control, and the continuous control, are proposed for the semi-active inerter to approximate the skyhook inerter. Numerical simulations are performed to demonstrate the effectiveness and performances of these control laws. It is shown that the semi-active realizations of the skyhook inerter by using the proposed control laws can achieve over 10% improvement compared with the traditional strut, and similar performances are obtained for these control laws, with slight differences with respect to different static stiffnesses of the suspension system.

Intermittent hypoxia activates peptidylglycine alpha-amidating monooxygenase in rat brain stem via reactive oxygen species-mediated proteolytic processing.

PubMed

Sharma, Suresh D; Raghuraman, Gayatri; Lee, Myeong-Seon; Prabhakar, Nanduri R; Kumar, Ganesh K

2009-01-01

Intermittent hypoxia (IH) associated with sleep apneas leads to cardiorespiratory abnormalities that may involve altered neuropeptide signaling. The effects of IH on neuropeptide synthesis have not been investigated. Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) catalyzes the alpha-amidation of neuropeptides, which confers biological activity to a large number of neuropeptides. PAM consists of O(2)-sensitive peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) activities. Here, we examined whether IH alters neuropeptide synthesis by affecting PAM activity and, if so, by what mechanisms. Experiments were performed on the brain stem of adult male rats exposed to IH (5% O(2) for 15 s followed by 21% O(2) for 5 min; 8 h/day for up to 10 days) or continuous hypoxia (0.4 atm for 10 days). Analysis of brain stem extracts showed that IH, but not continuous hypoxia, increased PHM, but not PAL, activity of PAM and that the increase of PHM activity was associated with a concomitant elevation in the levels of alpha-amidated forms of substance P and neuropeptide Y. IH increased the relative abundance of 42- and 35-kDa forms of PHM ( approximately 1.6- and 2.7-fold, respectively), suggesting enhanced proteolytic processing of PHM, which appears to be mediated by an IH-induced increase of endoprotease activity. Kinetic analysis showed that IH increases V(max) but has no effect on K(m). IH increased generation of reactive oxygen species in the brain stem, and systemic administration of antioxidant prevented IH-evoked increases of PHM activity, proteolytic processing of PHM, endoprotease activity, and elevations in substance P and neuropeptide Y amide levels. Taken together, these results demonstrate that IH activates PHM in rat brain stem via reactive oxygen species-dependent posttranslational proteolytic processing and further suggest that PAM activation may contribute to IH-mediated peptidergic neurotransmission in rat brain stem.

Visual Tracking Using 3D Data and Region-Based Active Contours

DTIC Science & Technology

2016-09-28

adaptive control strategies which explicitly take uncertainty into account. Filtering methods ranging from the classical Kalman filters valid for...linear systems to the much more general particle filters also fit into this framework in a very natural manner. In particular, the particle filtering ...the number of samples required for accurate filtering increases with the dimension of the system noise. In our approach, we approximate curve

CRTS-II Detection of Increased Optical Activity from CTA 102

NASA Astrophysics Data System (ADS)

Djorgovski, S. G.; Drake, A. J.; Mahabal, A. A.; Graham, M. J.; Christensen, E.; Larson, S. M.

2017-12-01

We report the detection of significant optical brightening of FSRQ CTA 102 by CRTS-II on 2017 Dec. 8.15 UT. At that time CTA 102 was seen to have risen approximately 1.4 mags (to V_CSS = 14.15) compared with previous observations taken on 2017 Nov. 23 UT. Additional survey observations taken on 2017 Dec. 15 UT show CTA 102 at V_CSS = 14.05.

The Antiepileptic Drug Levetiracetam Suppresses Non-Convulsive Seizure Activity and Reduces Ischemic Brain Damage in Rats Subjected to Permanent Middle Cerebral Artery Occlusion

PubMed Central

Cuomo, Ornella; Rispoli, Vincenzo; Leo, Antonio; Politi, Giovanni Bosco; Vinciguerra, Antonio; di Renzo, Gianfranco; Cataldi, Mauro

2013-01-01

The antiepileptic drug Levetiracetam (Lev) has neuroprotective properties in experimental stroke, cerebral hemorrhage and neurotrauma. In these conditions, non-convulsive seizures (NCSs) propagate from the core of the focal lesion into perilesional tissue, enlarging the damaged area and promoting epileptogenesis. Here, we explore whether Lev neuroprotective effect is accompanied by changes in NCS generation or propagation. In particular, we performed continuous EEG recordings before and after the permanent occlusion of the middle cerebral artery (pMCAO) in rats that received Lev (100 mg/kg) or its vehicle immediately before surgery. Both in Lev-treated and in control rats, EEG activity was suppressed after pMCAO. In control but not in Lev-treated rats, EEG activity reappeared approximately 30-45 min after pMCAO. It initially consisted in single spikes and, then, evolved into spike-and-wave and polyspike-and-wave discharges. In Lev-treated rats, only rare spike events were observed and the EEG power was significantly smaller than in controls. Approximately 24 hours after pMCAO, EEG activity increased in Lev-treated rats because of the appearance of polyspike events whose power was, however, significantly smaller than in controls. In rats sacrificed 24 hours after pMCAO, the ischemic lesion was approximately 50% smaller in Lev-treated than in control rats. A similar neuroprotection was observed in rats sacrificed 72 hours after pMCAO. In conclusion, in rats subjected to pMCAO, a single Lev injection suppresses NCS occurrence for at least 24 hours. This electrophysiological effect could explain the long lasting reduction of ischemic brain damage caused by this drug. PMID:24236205

Activity, energy intake, obesity, and the risk of incident kidney stones in postmenopausal women: a report from the Women's Health Initiative.

PubMed

Sorensen, Mathew D; Chi, Thomas; Shara, Nawar M; Wang, Hong; Hsi, Ryan S; Orchard, Tonya; Kahn, Arnold J; Jackson, Rebecca D; Miller, Joe; Reiner, Alex P; Stoller, Marshall L

2014-02-01

Obesity is a strong risk factor for nephrolithiasis, but the role of physical activity and caloric intake remains poorly understood. We evaluated this relationship in 84,225 women with no history of stones as part of the Women's Health Initiative Observational Study, a longitudinal, prospective cohort of postmenopausal women enrolled from 1993 to 1998 with 8 years' median follow-up. The independent association of physical activity (metabolic equivalents [METs]/wk), calibrated dietary energy intake, and body mass index (BMI) with incident kidney stone development was evaluated after adjustment for nephrolithiasis risk factors. Activity intensity was evaluated in stratified analyses. Compared with the risk in inactive women, the risk of incident stones decreased by 16% in women with the lowest physical activity level (adjusted hazard ratio [aHR], 0.84; 95% confidence interval [95% CI], 0.74 to 0.97). As activity increased, the risk of incident stones continued to decline until plateauing at a decrease of approximately 31% for activity levels ≥10 METs/wk (aHR, 0.69; 95% CI, 0.60 to 0.79). Intensity of activity was not associated with stone formation. As dietary energy intake increased, the risk of incident stones increased by up to 42% (aHR, 1.42; 95% CI, 1.02 to 1.98). However, intake <1800 kcal/d did not protect against stone formation. Higher BMI category was associated with increased risk of incident stones. In summary, physical activity may reduce the risk of incident kidney stones in postmenopausal women independent of caloric intake and BMI, primarily because of the amount of activity rather than exercise intensity. Higher caloric intake further increases the risk of incident stones.

The presence of a protein activator of sarcolemmal polyphosphoinositide phospholipase C in cardiac cytosol

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

Quist, E.E.; Kriewaldt, S.D.; Powell, P.B.

1989-01-01

To study polyphosphoinositide phospholipase (PL) C, isolated sarcolemmal membranes were preincubated with Mg({sup 32}P)-ATP to label phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-diphosphate (PIP{sub 2}). After washing, PLC activity was determined by measuring the release of {sup 32}P-labeled inositol diphosphate (IP{sub 2}) and/or inositol trisphospate (IP{sub 3}) from membrane PIP and PIP{sub 2} during incubation at 25{degree}C and pH 7.4. Increasing concentrations of Ca{sup 2+} (0-100 {mu}M) increased IP{sub 2} by 100% over the 0 Ca{sup 2+} control levels. Ca{sup 2+} dependent PLC hydrolyzed both PIP and PIP{sub 2} with apparent D{sub A}'s of approximately 0.5 and 70 {mu}M. Addition ofmore » dialyzed cytosol further increased IP{sub 2} release by 250% without affecting the K{sub A}'s for Ca{sup 2+} activation. The cytosolic activator was partially purified by DEAE Sephacel chromatography was heat labile and sensitive to trypsin pretreatment identifying it as a protein. In contrast, 10 mM NaF increased the Ca{sup 2+} affinity for PLC 2-fold. These results show that cardiac sarcolemma possess a membrane bound Ca{sup 2+} dependent PLC activity which is regulated by a cytosolic protein activator and a G protein. The cytosolic activator would potentially amplify the amount of sarcolemmal polyphosphoinositides hydrolyzed by PLC in response to muscarinic receptor activation by acetylcholine. In addition, activation of PLC by NaF or other G protein activators could result from increasing the Ca{sup 2+} affinity of PLC to physiological intracellular Ca{sup 2+} levels.« less

[Renin-angiotensin-aldosterone system activity during head-up tilt testing in patients with vasovagal syncope].

PubMed

Gajek, Jacek; Zyśko, Dorota; Mazurek, Walentyna

2005-08-01

The stimulation of renin-angiotensin-aldosterone (RAA) system during tilt table test is caused by sympathetic nervous system activation by orthostatic stress and a serotonin release as well. In healthy individuals increase of plasma renin activity during test with maximal values on the peak of the test was described. The aim of the study was to assess the activation of RAAS in patients with neurally mediated syncope during the tilt table test by means of plasma renin activity and serum aldosterone levels. The study was carried out in 31 patients aged 39.4 +/- 15.0 years (18 women and 13 men) with neurally mediated syncope during tilt test. Plasma renin activity was assessed in the baseline conditions, immediately after the test and 10 minutes after the test using radioenzymatic assay. Aldosterone concentrations were measured radioimmunologically, twice: after 30 minutes supine rest and after the syncope. Plasma renin activity during supine rest was 2.2 +/- 2.4 ng/ml/h, rose after the syncope 2.5-fold to 5.2 +/- 4.5 ng/ml/h (p < 0.001 comparing to baseline) stayed on similar level approximately for the next 10 minutes--4.9 +/- 5.5 ng/ml/h (p = n.s.). In 11 patients (35%) 10 minutes after the test even further increase of PRA was observed. Serum aldosterone level increased significantly immediately after tilt test (90.0 +/- 72.9 vs 178.8 +/- 150.1 pg/ml, p < 0.01). Authors showed, that in patients with NMS plasma renin activity increases and this increase lasts for 10 minutes after the syncope and the concentration of aldosterone increases immediately after tilt test.

Are Structural Changes in Polish Rural Areas Fostering Leisure-Time Physical Activity?

PubMed Central

Biernat, Elżbieta; Bartkiewicz, Piotr; Buchholtz, Sonia

2017-01-01

Background: In this study, we analyze the determinants of leisure-time physical activity (LTPA) of farmers and non-farmers living in rural areas. Methods: We use statistical analysis to describe urban and rural populations, as well as econometric techniques (Heckman regressions and propensity score matching) to assess the role of rural lifestyle in physical activity. Results: World Health Organization (WHO) pro-health PA (physical activity) recommendations are not met by 66% of farmers and 49% of other dwellers in rural areas. Approximately two thirds of them are completely inactive. Farmers enjoy vigorous PA (VPA), cycling and recreational walking less than their non-farming counterparts and are 46% less likely to be active than them; however the difference disappears when they take up an activity. The amount of PA is negatively correlated with age, but tends to increase for older people compared to those in middle age. Women are 6%–7% less active than men, yet the odds of being active at all are higher for women than for men. Household size is negatively correlated with LTPA. Conclusion: Considering the structural changes, rural area dwellers, especially farmers, require public intervention aimed at increasing their awareness of the advantages of LTPA. PMID:28368322

129I in the oceans: origins and applications.

PubMed

Raisbeck, G M; Yiou, F

1999-09-30

The quantity of the long lived (half-life 15.7 million years) radioactive isotope 129I in the pre-nuclear age ocean was approximately 100 kg. Various nuclear related activities, including weapons testing, nuclear fuel reprocessing, Chernobyl and other authorized or non-authorized dumping of radioactive waste have increased the ocean inventory of 129I by more than one order of magnitude. The most important of these sources are the direct marine discharges from the commercial reprocessing facilities at La Hague (France) and Sellafield (UK) which have discharged approximately 1640 kg in the English Channel, and approximately 720 kg in the Irish Sea, respectively. We discuss how this 129I can be used as both a 'pathway' and 'transit time' tracer in the North Atlantic and Arctic oceans, as well as a parameter for distinguishing between reprocessed and non-reprocessed nuclear waste in the ocean, and as a proxy for the transport and dilution of other soluble pollutants input to the North Sea.

Body position and activity, but not heart rate, affect pump flows in patients with continuous-flow left ventricular assist devices.

PubMed

Muthiah, Kavitha; Gupta, Sunil; Otton, James; Robson, Desiree; Walker, Robyn; Tay, Andre; Macdonald, Peter; Keogh, Anne; Kotlyar, Eugene; Granger, Emily; Dhital, Kumud; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S

2014-08-01

The aim of this study was to determine the contribution of pre-load and heart rate to pump flow in patients implanted with continuous-flow left ventricular assist devices (cfLVADs). Although it is known that cfLVAD pump flow increases with exercise, it is unclear if this increment is driven by increased heart rate, augmented intrinsic ventricular contraction, or enhanced venous return. Two studies were performed in patients implanted with the HeartWare HVAD. In 11 patients, paced heart rate was increased to approximately 40 beats/min above baseline and then down to approximately 30 beats/min below baseline pacing rate (in pacemaker-dependent patients). Ten patients underwent tilt-table testing at 30°, 60°, and 80° passive head-up tilt for 3 min and then for a further 3 min after ankle flexion exercise. This regimen was repeated at 20° passive head-down tilt. Pump parameters, noninvasive hemodynamics, and 2-dimensional echocardiographic measures were recorded. Heart rate alteration by pacing did not affect LVAD flows or LV dimensions. LVAD pump flow decreased from baseline 4.9 ± 0.6 l/min to approximately 4.5 ± 0.5 l/min at each level of head-up tilt (p < 0.0001 analysis of variance). With active ankle flexion, LVAD flow returned to baseline. There was no significant change in flow with a 20° head-down tilt with or without ankle flexion exercise. There were no suction events. Centrifugal cfLVAD flows are not significantly affected by changes in heart rate, but they change significantly with body position and passive filling. Previously demonstrated exercise-induced changes in pump flows may be related to altered loading conditions, rather than changes in heart rate. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

P2 purinoceptors regulate calcium-activated chloride and fluid transport in 31EG4 mammary epithelia.

PubMed

Blaug, Sasha; Rymer, Jodi; Jalickee, Stephen; Miller, Sheldon S

2003-04-01

It has been reported that secretory mammary epithelial cells (MEC) release ATP, UTP, and UDP upon mechanical stimulation. Here we examined the physiological changes caused by ATP/UTP in nontransformed, clonal mouse mammary epithelia (31EG4 cells). In control conditions, transepithelial potential (apical side negative) and resistance were -4.4 +/- 1.3 mV (mean +/- SD, n = 12) and 517.7 +/- 39.4 Omega. cm(2), respectively. The apical membrane potential was -43.9 +/- 1.7 mV, and the ratio of apical to basolateral membrane resistance (R(A)/R(B)) was 3.5 +/- 0.2. Addition of ATP or UTP to the apical or basolateral membranes caused large voltage and resistance changes with an EC(50) of approximately 24 microM (apical) and approximately 30 microM (basal). Apical ATP/UTP (100 microM) depolarized apical membrane potential by 17.6 +/- 0.8 mV (n = 7) and decreased R(A)/R(B) by a factor of approximately 3. The addition of adenosine to either side (100 microM) had no effect on any of these parameters. The ATP/UTP responses were partially inhibited by DIDS and suramin and mediated by a transient increase in free intracellular Ca(2+) concentration (427 +/- 206 nM; 15-25 microM ATP, apical; n = 6). This Ca(2+) increase was blocked by cyclopiazonic acid, by BAPTA, or by xestospongin C. 31EG4 MEC monolayers also secreted or absorbed fluid in the resting state, and ATP or UTP increased fluid secretion by 5.6 +/- 3 microl x cm(-2) x h(-1) (n = 10). Pharmacology experiments indicate that 31EG4 epithelia contain P2Y(2) purinoceptors on the apical and basolateral membranes, which upon activation stimulate apical Ca(2+)-dependent Cl channels and cause fluid secretion across the monolayer. This suggests that extracellular nucleotides could play a fundamental role in mammary gland paracrine signaling and the regulation of milk composition in vivo.

Comparison between maximal lengthening and shortening contractions for biceps brachii muscle oxygenation and hemodynamics.

PubMed

Muthalib, Makii; Lee, Hoseong; Millet, Guillaume Y; Ferrari, Marco; Nosaka, Kazunori

2010-09-01

Eccentric contractions (ECC) require lower systemic oxygen (O2) and induce greater symptoms of muscle damage than concentric contractions (CON); however, it is not known if local muscle oxygenation is lower in ECC than CON during and following exercise. This study compared between ECC and CON for changes in biceps brachii muscle oxygenation [tissue oxygenation index (TOI)] and hemodynamics [total hemoglobin volume (tHb)=oxygenated-Hb+deoxygenated-Hb], determined by near-infrared spectroscopy over 10 sets of 6 maximal contractions of the elbow flexors of 10 healthy subjects. This study also compared between ECC and CON for changes in TOI and tHb during a 10-s sustained and 30-repeated maximal isometric contraction (MVC) task measured immediately before and after and 1-3 days following exercise. The torque integral during ECC was greater (P<0.05) than that during CON by approximately 30%, and the decrease in TOI was smaller (P<0.05) by approximately 50% during ECC than CON. Increases in tHb during the relaxation phases were smaller (P<0.05) by approximately 100% for ECC than CON; however, the decreases in tHb during the contraction phases were not significantly different between sessions. These results suggest that ECC utilizes a lower muscle O2 relative to O2 supply compared with CON. Following exercise, greater (P<0.05) decreases in MVC strength and increases in plasma creatine kinase activity and muscle soreness were evident 1-3 days after ECC than CON. Torque integral, TOI, and tHb during the sustained and repeated MVC tasks decreased (P<0.01) only after ECC, suggesting that muscle O2 demand relative to O2 supply during the isometric tasks was decreased after ECC. This could mainly be due to a lower maximal muscle mass activated as a consequence of muscle damage; however, an increase in O2 supply due to microcirculation dysfunction and/or inflammatory vasodilatory responses after ECC is recognized.

Motivations, interests and retention of female minority engineering students

NASA Astrophysics Data System (ADS)

Syed, Naila

In an effort to potentially increase low enrollment of females, particularly minorities, in Engineering programs, this study used a survey to determine motivations, interests and retention of current female Engineering students. A total of 82 participants from varied ethnic (non-Hispanic white, Euro-American, African American, Hispanic American, Asian American, South Asian, Arab American, and Native American participants) and education (high school senior, undergraduate, graduate, and in-service Engineers) backgrounds filled out the survey. With approximately half of the participants being non-minorities (non-Hispanic white or Euro-American), they served as the `control' group for the data, and the comparison group was the minority participants. Notable differences between the two groups were: student participation in female community groups, and extra-curricular activities like sports and arts (writing, drama and band) clubs. Increasing female-minority participation in these clubs and other extra-curricular activities may potentially increase their enrollment numbers in Engineering programs.

PRESSURE-VOLUME RELATIONSHIP OF THE FUNDULUS EGG IN SEA WATER AND IN SUCROSE

PubMed Central

Kao, C. Y.

1956-01-01

Upon activation, an internal hydrostatic pressure develops within the Fundulus egg, and compresses the egg proper to a reduced volume. When the perivitelline pressure is abolished by a highly hypertonic sucrose solution, the egg volume increases. As sucrose penetrates the chorion, the volume again decreases. The relation between P and V in these conditions is inverse, and approximates a rectangular hyperbola. The limiting factor causing most of the deviation is shown to be the incompressible fraction. It is concluded that the volume of the egg proper is controlled by the perivitelline pressure, and that the effect of hypertonic sucrose solution is exerted by lowering the pressure and thereby increasing membrane permeability non-specifically. It is also shown that some permanent alterations occur within the plasma membrane during activation that reduce the permeance, and thereby, increase the incompressible fraction. PMID:13357739

Underwater Shockwave Pretreatment Process to Improve the Scent of Extracted Citrus junos Tanaka (Yuzu) Juice

PubMed Central

Touyama, Akiko; Nakada, Shina; Higa, Osamu; Itoh, Shigeru

2017-01-01

Citrus junos Tanaka (yuzu) has a strong characteristic aroma and thus its juice is used in various Japanese foods. Herein, we evaluate the volatile compounds in yuzu juice to investigate whether underwater shockwave pretreatment affects its scent. A shockwave pretreatment at increased discharge and energy of 3.5 kV and 4.9 kJ, respectively, increased the content of aroma-active compounds. Moreover, the underwater shockwave pretreatment afforded an approximate tenfold increase in the scent intensity of yuzu juice cultivated in Rikuzentakata. The proposed treatment method exhibited reliable and good performance for the extraction of volatile and aroma-active compounds from the yuzu fruit. The broad applicability and high reliability of this technique for improving the scent of yuzu fruit juice were demonstrated, confirming its potential for application to a wide range of food extraction processes. PMID:28761874

Phosphatidylserine-mediated platelet clearance by endothelium decreases platelet aggregates and procoagulant activity in sepsis.

PubMed

Ma, Ruishuang; Xie, Rui; Yu, Chengyuan; Si, Yu; Wu, Xiaoming; Zhao, Lu; Yao, Zhipeng; Fang, Shaohong; Chen, He; Novakovic, Valerie; Gao, Chunyan; Kou, Junjie; Bi, Yayan; Thatte, Hemant S; Yu, Bo; Yang, Shufen; Zhou, Jin; Shi, Jialan

2017-07-10

The mechanisms that eliminate activated platelets in inflammation-induced disseminated intravascular coagulation (DIC) in micro-capillary circulation are poorly understood. This study explored an alternate pathway for platelet disposal mediated by endothelial cells (ECs) through phosphatidylserine (PS) and examined the effect of platelet clearance on procoagulant activity (PCA) in sepsis. Platelets in septic patients demonstrated increased levels of surface activation markers and apoptotic vesicle formation, and also formed aggregates with leukocytes. Activated platelets adhered were and ultimately digested by ECs in vivo and in vitro. Blocking PS on platelets or αvβ3 integrin on ECs attenuated platelet clearance resulting in increased platelet count in a mouse model of sepsis. Furthermore, platelet removal by ECs resulted in a corresponding decrease in platelet-leukocyte complex formation and markedly reduced generation of factor Xa and thrombin on platelets. Pretreatment with lactadherin significantly increased phagocytosis of platelets by approximately 2-fold, diminished PCA by 70%, prolonged coagulation time, and attenuated fibrin formation by 50%. Our results suggest that PS-mediated clearance of activated platelets by the endothelium results in an anti-inflammatory, anticoagulant, and antithrombotic effect that contribute to maintaining platelet homeostasis during acute inflammation. These results suggest a new therapeutic target for impeding the development of DIC.

Locus ceruleus control of state-dependent gene expression.

PubMed

Cirelli, Chiara; Tononi, Giulio

2004-06-09

Wakefulness and sleep are accompanied by changes in behavior and neural activity, as well as by the upregulation of different functional categories of genes. However, the mechanisms responsible for such state-dependent changes in gene expression are unknown. Here we investigate to what extent state-dependent changes in gene expression depend on the central noradrenergic (NA) system, which is active in wakefulness and reduces its firing during sleep. We measured the levels of approximately 5000 transcripts expressed in the cerebral cortex of control rats and in rats pretreated with DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine], a neurotoxin that removes the noradrenergic innervation of the cortex. We found that NA depletion reduces the expression of approximately 20% of known wakefulness-related transcripts. Most of these transcripts are involved in synaptic plasticity and in the cellular response to stress. In contrast, NA depletion increased the expression of the sleep-related gene encoding the translation elongation factor 2. These results indicate that the activity of the central NA system during wakefulness modulates neuronal transcription to favor synaptic potentiation and counteract cellular stress, whereas its inactivity during sleep may play a permissive role to enhance brain protein synthesis.

Experimental electromagnetic effects on the model organism Escherichia coli and the bacteriophage T4

NASA Astrophysics Data System (ADS)

Lisiewski, Darlene Mildred

This experimentally-based work was designed to answer the research question as to whether the phenomenon of nuclear magnetic resonance (NMR) can produce observable effects upon the bacterial virus activity of T4, with such activity demonstrated through the infection of its host bacterium Escherichia coli. The biological samples were placed for three hours within a coil antenna assembly propagating oscillating fields of radio frequency electromagnetic energy generated at the frequency of 5.6 MHz, and set at right angles within a magnetic field of 1450 gauss (recognizing such conditions are not set for the maximum effective resonance for hydrogen nuclei). The laboratory technique of plaque formation was the basis upon which the statistically tested data were compiled. Exposure of the bacterium alone exhibited an increase in viral activity over the control group (40--68% higher numbers of plaque formation), while exposure of T4 alone saw a decrease (approximately 23%) in infection rates. Depending on the protocol, placement of both T4 and E. coli into the coil assembly saw a decrease of either approximately 50% or 42% in infection rates. Future research must address identification of the effects being observed.

Synergistic activation of the androgen receptor by bombesin and low-dose androgen.

PubMed

Dai, Jie; Shen, Ruoqian; Sumitomo, Makoto; Stahl, Rosalyn; Navarro, Daniel; Gershengorn, Marvin C; Nanus, David M

2002-07-01

Neuropeptide growth factors such as bombesinare implicated in progression to androgen-independent prostate cancer (PC). We examined the impact of bombesin on androgen receptor (AR)-mediated gene expression. The AR together with the AR-responsive probasin ARR(3)tk-luc or PSA-pPUE-ELB-luc promoter was cotransfected into Swiss 3T3 and PC-3 cells, both of which express high-affinity bombesin receptors; the cells were incubated with bombesin (0-50 nM) and dihydrotestosterone (DHT; 0-10 nM), and luciferase activities were measured. DHT increased transcription approximately 40-fold at doses of 1 and 10 nM but had no effect at 10 pM. Bombesin alone, or with 1 or 10 nM DHT, did not further increase transcription. However, 5 nM bombesin and 10 pM DHT, doses that by themselves had no effect, resulted in a approximately 20 fold increase in transcription (P < 0.005). This synergistic effect was blocked by bombesin receptor antagonists and recombinant neutral endopeptidase, which hydrolyzes bombesin. Bombesin and DHT together also increased binding of nuclear extracts from PC-3 cells transfected with AR to a consensus androgen response element in mobility shift assays and increased the level of secreted prostate-specific antigen in LNCaP cell supernatant compared with DHT or bombesin alone. Immunoprecipitation of AR from (32)P-labeled LNCaP cells revealed that 5 nM bombesin + 10 pM DHT induced AR phosphorylation comparable with 1 nM DHT, whereas bombesin or 10 pM DHT alone did not. These data indicate that bombesin can synergize with low (castrate) levels of DHT to induce AR-mediated transcription and suggest that neuropeptides promote AR-mediated signaling in androgen-independent prostate cancer.

Preparation and evaluation of GAC-based iron-containing adsorbents for arsenic removal.

PubMed

Gu, Zhimang; Fang, Jun; Deng, Baolin

2005-05-15

Granular activated carbon-based, iron-containing adsorbents (As-GAC) were developed for effective removal of arsenic from drinking water. Granular activated carbon (GAC) was used primarily as a supporting medium for ferric iron that was impregnated by ferrous chloride (FeCl2) treatment, followed by chemical oxidation. Sodium hypochlorite (NaClO) was the most effective oxidant, and carbons produced from steam activation of lignite were most suitable for iron impregnation and arsenic removal. Two As-GAC materials prepared by FeCl2 treatment (0.025 -0.40 M) of Dacro 20 x 50 and Dacro 20 x 40LI resulted in a maximum impregnated iron of 7.89% for Dacro 20 x 50 and 7.65% for Dacro 20 x 40Ll. Nitrogen adsorption-desorption analyses showed the BET specific surface area, total pore volume, porosity, and average mesoporous diameter all decreased with iron impregnation, indicating that some micropores were blocked. SEM studies with associated EDS indicated that the distribution of iron in the adsorbents was mainly on the edge of As-GAC in the low iron content (approximately 1% Fe) sample but extended to the center at the higher iron content (approximately 6% Fe). When the iron content was > approximately 7%, an iron ring formed at the edge of the GAC particles. No difference in X-ray diffraction patterns was observed between untreated GAC and the one with 4.12% iron, suggesting that the impregnated iron was predominantly in amorphous form. As-GAC could remove arsenic most efficiently when the iron content was approximately 6%; further increases of iron decreased arsenic adsorption. The removal of arsenate occurred in a wide range of pH as examined from 4.4 to 11, but efficiency was decreased when pH was higher than 9.0. The presence of phosphate and silicate could significantly decrease arsenate removal at pH > 8.5, while the effects of sulfate, chloride, and fluoride were minimal. Column studies showed that both As(V) and As(III) could be removed to below 10 microg/L within 6000 empty bed volume when the groundwater containing approximately 50 microg/L of arsenic was treated.

Radiation-induced inflammatory markers of brain injury are modulated by PPARdelta activation in vitro and in vivo

NASA Astrophysics Data System (ADS)

Schnegg, Caroline Isabel

As a result of improvements in cancer therapy and health care, the population of long-term cancer survivors is growing. For these approximately 12 million long-term cancer survivors, brain metastases are a significant risk. Fractionated partial or whole-brain irradiation (fWBI) is often required to treat both primary and metastatic brain cancer. Radiation-induced normal tissue injury, including progressive cognitive impairment, however, can significantly affect the well-being of the approximately 200,000 patients who receive these treatments each year. Recent reports indicate that radiation-induced brain injury is associated with chronic inflammatory and oxidative stress responses, as well as increased microglial activation in the brain. Anti-inflammatory drugs may, therefore, be a beneficial therapy to mitigate radiation-induced brain injury. We hypothesized that activation of peroxisomal proliferator activated receptor delta (PPARō) would prevent or ameliorate radiation-induced brain injury, including cognitive impairment, in part, by alleviating inflammatory responses in microglia. For our in vitro studies, we hypothesized that PPARō activation would prevent the radiation-induced inflammatory response in microglia following irradiation. Incubating BV-2 murine microglial cells with the (PPAR)ō agonist, L-165041, prevented the radiation-induced increase in: i) intracellular ROS generation, ii) Cox-2 and MCP-1 expression, and iii) IL-1β and TNF-α message levels. This occured, in part, through PPARō-mediated modulation of stress activated kinases and proinflammatory transcription factors. PPARō inhibited NF-κB via transrepression by physically interacting with the p65 subunit, and prevented activation of the PKCα/MEK1/2/ERK1/2/AP-1 pathway by inhibiting the radiation-induced increase in intracellular ROS generation. These data support the hypothesis that PPARō activation can modulate the radiation-induced oxidative stress and inflammatory responses in microglia in vitro. To extend our in vitro findings in vivo, we investigated whether administration of the peroxisomal proliferator-activated receptor (PPAR)ä agonist, GW0742, prevented radiation-induced brain injury in C57Bl/6 WT mice. Our data demonstrate that GW0742 prevented the radiation-induced increase in the number of activated microglia (CD68+ cells) in wild-type (WT) mice 1 week following 10 Gy WBI. Furthermore, GW0742 inhibited the WBI-induced increase in IL-1β message levels and ERK phosphorylation observed 3 h post-irradiation. In contrast, GW0742 administration failed to modulate the radiation-induced decrease in hippocampal neurogenesis (NeuN+/BrdU+ cells) determined 2 months after irradiation, or mitigate hippocampal-dependent spatial memory impairment observed 3 months post-irradiation using the Barnes Maze task. We used PPARō knockout (KO) mice to examine if the effects of GW0742 are PPARō-dependent. Unexpectedly, PPARō KO mice exhibited a differential response following WBI compared to WT mice; therefore, we were unable to make mechanistic conclusions about GW0742. KO mice do not exhibit a WBI-induced increase in activated microglia; however, they appeared to display a pronounced astrocytic response. In particular, PPARō KO but not WT mice displayed increased GFAP message levels 2 months after WBI. Additionally, the number of GFAP+ cells was reduced significantly in the WT mice 2 months after WBI, but it was not in the PPARō KO mice. These results demonstrate that: i) GW0742 prevents the radiation-induced increase in microglial activation and inflammatory markers, and ii) WT and PPARō KO mice have a differential response to WBI.

National physical activity surveillance: Users of wearable activity monitors as a potential data source.

PubMed

Omura, John D; Carlson, Susan A; Paul, Prabasaj; Watson, Kathleen B; Fulton, Janet E

2017-03-01

The objective of this study was to assess usage patterns of wearable activity monitors among US adults and how user characteristics might influence physical activity estimates from this type of sample. We analyzed data on 3367 respondents to the 2015 HealthStyles survey, an annual consumer mail panel survey conducted on a nationwide sample. Approximately 1 in 8 respondents (12.5%) reported currently using a wearable activity monitor. Current use varied by sex, age, and education level. Use increased with physical activity level from 4.3% for inactive adults to 17.4% for active adults. Overall, 49.9% of all adults met the aerobic physical activity guideline, while this prevalence was 69.5% among current activity monitor users. Our findings suggest that current users of wearable activity monitors are not representative of the overall US population. Estimates of physical activity levels using data from wearable activity monitors users may be an overestimate and therefore data from users alone may have a limited role in physical activity surveillance.

Community-Based Rehabilitation to Improve Stroke Survivors' Rehabilitation Participation and Functional Recovery.

PubMed

Ru, Xiaojuan; Dai, Hong; Jiang, Bin; Li, Ninghua; Zhao, Xingquan; Hong, Zhen; He, Li; Wang, Wenzhi

2017-07-01

The aim of this study was to evaluate the effectiveness of a community-based rehabilitation appropriate technique (CRAT) intervention program in increasing rehabilitation participation and improving functional recovery of stroke survivors. This study followed a quasi-experimental design. In each of 5 centers servicing approximately 50,000 individuals, 2 communities were designated as either the intervention or control community. A CRAT intervention program, including 2-year rehabilitation education and 3-month CRAT treatment, was regularly implemented in the intervention communities, whereas there was no special intervention in the control community. Two sampling surveys, at baseline and after intervention, were administered to evaluate the rehabilitation activity undertaken. In intervention communities, stroke survivor's motor function, daily activity, and social activity were evaluated pretreatment and posttreatment, using the Fugl-Meyer Motor Function Assessment, Barthel index, and Social Functional Activities Questionnaire. The proportion of individuals participating in rehabilitation-related activity was increased significantly (P < 0.05) in intervention communities, as compared with control communities. In intervention communities, the patients' Fugl-Meyer Motor Function Assessment, Barthel index, and Social Functional Activities Questionnaire scores were significantly improved after rehabilitation (P < 0.05) across all ages and disease courses, except for the FAQ scores in patients younger than 50 years (P > 0.05). Community-based rehabilitation appropriate technique increases rehabilitation participation rates and enhances motor function, daily activity, and social activity of stroke survivors.

Intensive Lifestyle Intervention for Obesity: Principles, Practices, and Results.

PubMed

Webb, Victoria L; Wadden, Thomas A

2017-05-01

Using the Guidelines for the Management of Overweight and Obesity in Adults as a framework, this article reviews intensive lifestyle interventions for weight loss. The Guidelines recommend a minimum of 6 months of high-intensity, comprehensive lifestyle intervention, consisting of a reduced-calorie diet, increased physical activity, and behavior therapy. Persons with obesity typically lose approximately 8 kg (approximately 8% of initial weight) with this approach, accompanied by improvements in health and quality of life. To prevent weight regain, the Guidelines recommend a 1-year weight loss maintenance program that includes at least monthly counseling with a trained interventionist. Lifestyle interventions usually are delivered in-person; however, treatment increasingly is being disseminated through community- and commercial-based programs, as well as delivered by telephone, Internet, and smartphone platforms. These latter modalities expand treatment reach but usually produce smaller weight losses than in-person interventions. The review concludes with an examination of challenges in weight management. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Widespread receptivity to neuropeptide PDF throughout the neuronal circadian clock network of Drosophila revealed by real-time cyclic AMP imaging.

PubMed

Shafer, Orie T; Kim, Dong Jo; Dunbar-Yaffe, Richard; Nikolaev, Viacheslav O; Lohse, Martin J; Taghert, Paul H

2008-04-24

The neuropeptide PDF is released by sixteen clock neurons in Drosophila and helps maintain circadian activity rhythms by coordinating a network of approximately 150 neuronal clocks. Whether PDF acts directly on elements of this neural network remains unknown. We address this question by adapting Epac1-camps, a genetically encoded cAMP FRET sensor, for use in the living brain. We find that a subset of the PDF-expressing neurons respond to PDF with long-lasting cAMP increases and confirm that such responses require the PDF receptor. In contrast, an unrelated Drosophila neuropeptide, DH31, stimulates large cAMP increases in all PDF-expressing clock neurons. Thus, the network of approximately 150 clock neurons displays widespread, though not uniform, PDF receptivity. This work introduces a sensitive means of measuring cAMP changes in a living brain with subcellular resolution. Specifically, it experimentally confirms the longstanding hypothesis that PDF is a direct modulator of most neurons in the Drosophila clock network.

A MHD channel study for the ETF conceptual design

NASA Technical Reports Server (NTRS)

Wang, S. Y.; Staiger, P. J.; Smith, J. M.

1981-01-01

The procedures and computations used to identify an MHD channel for a 540 mW(I) EFT-scale plant are presented. Under the assumed constraints of maximum E(x), E(y), J(y) and Beta; results show the best plant performance is obtained for active length, L is approximately 12 M, whereas in the initial ETF studies, L is approximately 16 M. As MHD channel length is reduced from 16 M, the channel enthalpy extraction falls off, slowly. This tends to reduce the MHD power output; however, the shorter channels result in lower heat losses to the MHD channel cooling water which allows for the incorporation of more low pressure boiler feedwater heaters into the system and an increase in steam plant efficiency. The net result of these changes is a net increase in the over all MHD/steam plant efficiency. In addition to the sensitivity of various channel parameters, the trade-offs between the level of oxygen enrichment and the electrical stress on the channel are also discussed.

A MHD channel study for the ETF conceptual design

NASA Astrophysics Data System (ADS)

Wang, S. Y.; Staiger, P. J.; Smith, J. M.

The procedures and computations used to identify an MHD channel for a 540 mW(I) EFT-scale plant are presented. Under the assumed constraints of maximum E(x), E(y), J(y) and Beta; results show the best plant performance is obtained for active length, L is approximately 12 M, whereas in the initial ETF studies, L is approximately 16 M. As MHD channel length is reduced from 16 M, the channel enthalpy extraction falls off, slowly. This tends to reduce the MHD power output; however, the shorter channels result in lower heat losses to the MHD channel cooling water which allows for the incorporation of more low pressure boiler feedwater heaters into the system and an increase in steam plant efficiency. The net result of these changes is a net increase in the over all MHD/steam plant efficiency. In addition to the sensitivity of various channel parameters, the trade-offs between the level of oxygen enrichment and the electrical stress on the channel are also discussed.

[The molecular-cellular mechanisms of learning in the edible snail].

PubMed

Nikitin, V P

1993-01-01

Elaboration of sensitization and associative habit of a rejection of a certain kind of food is accompanied by short-term and long-term changes of behaviour, bioelectric activity and the dynamics of bound calcium (Ca-b) level in the command neurons of defensive behaviour. Approximately in the course of an hour from the moment of the beginning of learning were revealed in general similar behavioural and neurophysiological effects during elaboration of both these habits. During elaboration of sensitization the responses to testing tactile stimulations, quinine and carrot juice applications appeared and/or markedly increased beginning from 50-60 minutes from the moment of the first sensitizing stimulation. During conditioning the responses to sensory stimulations characterizing the state of sensitization were also facilitated in 50-60 minutes. At the same time, responses to a conditioned stimulus appeared and increased approximately 30 minutes later. Protein synthesis blockers anisomycin and cyclohexamide blocked the development of the long-term neurophysiological and metabolic Ca-b effects during elaboration of sensitization.

Backside illuminated CMOS-TDI line scanner for space applications

NASA Astrophysics Data System (ADS)

Cohen, O.; Ben-Ari, N.; Nevo, I.; Shiloah, N.; Zohar, G.; Kahanov, E.; Brumer, M.; Gershon, G.; Ofer, O.

2017-09-01

A new multi-spectral line scanner CMOS image sensor is reported. The backside illuminated (BSI) image sensor was designed for continuous scanning Low Earth Orbit (LEO) space applications including A custom high quality CMOS Active Pixels, Time Delayed Integration (TDI) mechanism that increases the SNR, 2-phase exposure mechanism that increases the dynamic Modulation Transfer Function (MTF), very low power internal Analog to Digital Converters (ADC) with resolution of 12 bit per pixel and on chip controller. The sensor has 4 independent arrays of pixels where each array is arranged in 2600 TDI columns with controllable TDI depth from 8 up to 64 TDI levels. A multispectral optical filter with specific spectral response per array is assembled at the package level. In this paper we briefly describe the sensor design and present some electrical and electro-optical recent measurements of the first prototypes including high Quantum Efficiency (QE), high MTF, wide range selectable Full Well Capacity (FWC), excellent linearity of approximately 1.3% in a signal range of 5-85% and approximately 1.75% in a signal range of 2-95% out of the signal span, readout noise of approximately 95 electrons with 64 TDI levels, negligible dark current and power consumption of less than 1.5W total for 4 bands sensor at all operation conditions .

Drilling and operational sounds from an oil production island in the ice-covered Beaufort sea.

PubMed

Blackwell, Susanna B; Greene, Charles R; Richardson, W John

2004-11-01

Recordings of sounds underwater and in air, and of iceborne vibrations, were obtained at Northstar Island, an artificial gravel island in the Beaufort Sea near Prudhoe Bay (Alaska). The aim was to document the levels, characteristics, and range dependence of sounds and vibrations produced by drilling and oil production during the winter, when the island was surrounded by shore-fast ice. Drilling produced the highest underwater broadband (10-10,000 Hz) levels (maximum= 124 dB re: 1 microPa at 1 km), and mainly affected 700-1400 Hz frequencies. In contrast, drilling did not increase broadband levels in air or ice relative to levels during other island activities. Production did not increase broadband levels for any of the sensors. In all media, broadband levels decreased by approximately 20 dB/tenfold change in distance. Background levels underwater were reached by 9.4 km during drilling and 3-4 km without. In the air and ice, background levels were reached 5-10 km and 2-10 km from Northstar, respectively, depending on the wind but irrespective of drilling. A comparison of the recorded sounds with harbor and ringed seal audiograms showed that Northstar sounds were probably audible to seals, at least intermittently, out to approximately 1.5 km in water and approximately 5 km in air.

Ecosystem warming increases sap flow rates of northern red oak trees

DOE PAGES

Juice, Stephanie M.; Templer, Pamela H.; Phillips, Nathan G.; ...

2016-03-17

Over the next century, air temperature increases up to 5°C are projected for the northeastern United States. As evapotranspiration strongly influences water loss from terrestrial ecosystems, the ecophysiological response of trees to warming will have important consequences for forest water budgets. We measured growing season sap flow rates in mature northern red oak ( Quercus rubra L.) trees in a combined air (up to 5.5°C above ambient) and soil (up to 1.85°C above ambient at 6-cm depth) warming experiment at Harvard Forest, Massachusetts, United States. Through principal components analysis, we found air and soil temperatures explained the largest amount ofmore » variance in environmental variables associated with rates of sap flow, with relative humidity, photosynthetically active radiation and vapor pressure deficit having significant, but smaller, effects. On average, each 1°C increase in temperature increased sap flow rates by approximately 1100 kg H 2O m -2 sapwood area day-1 throughout the growing season and by 1200 kg H 2O m -2 sapwood area day -1 during the early growing season. Reductions in the number of cold winter days correlated positively with increased sap flow during the early growing season (a decrease in 100 heating-degree days was associated with a sapflow increase in approximately 5 kg H 2O m -2 sapwood area day -1). Soil moisture declined with increased treatment temperatures, and each soil moisture percentage decrease resulted in a decrease in sap flow of approximately 360 kg H2O m -22 sapwood area day -1. At night, soil moisture correlated positively with sap flow. Finally, these results demonstrate that warmer air and soil temperatures in winter and throughout the growing season lead to increased sap flow rates, which could affect forest water budgets throughout the year.« less

Ecosystem warming increases sap flow rates of northern red oak trees

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

Juice, Stephanie M.; Templer, Pamela H.; Phillips, Nathan G.

Over the next century, air temperature increases up to 5°C are projected for the northeastern United States. As evapotranspiration strongly influences water loss from terrestrial ecosystems, the ecophysiological response of trees to warming will have important consequences for forest water budgets. We measured growing season sap flow rates in mature northern red oak ( Quercus rubra L.) trees in a combined air (up to 5.5°C above ambient) and soil (up to 1.85°C above ambient at 6-cm depth) warming experiment at Harvard Forest, Massachusetts, United States. Through principal components analysis, we found air and soil temperatures explained the largest amount ofmore » variance in environmental variables associated with rates of sap flow, with relative humidity, photosynthetically active radiation and vapor pressure deficit having significant, but smaller, effects. On average, each 1°C increase in temperature increased sap flow rates by approximately 1100 kg H 2O m -2 sapwood area day-1 throughout the growing season and by 1200 kg H 2O m -2 sapwood area day -1 during the early growing season. Reductions in the number of cold winter days correlated positively with increased sap flow during the early growing season (a decrease in 100 heating-degree days was associated with a sapflow increase in approximately 5 kg H 2O m -2 sapwood area day -1). Soil moisture declined with increased treatment temperatures, and each soil moisture percentage decrease resulted in a decrease in sap flow of approximately 360 kg H2O m -22 sapwood area day -1. At night, soil moisture correlated positively with sap flow. Finally, these results demonstrate that warmer air and soil temperatures in winter and throughout the growing season lead to increased sap flow rates, which could affect forest water budgets throughout the year.« less

Evaluation of stochastic differential equation approximation of ion channel gating models.

PubMed

Bruce, Ian C

2009-04-01

Fox and Lu derived an algorithm based on stochastic differential equations for approximating the kinetics of ion channel gating that is simpler and faster than "exact" algorithms for simulating Markov process models of channel gating. However, the approximation may not be sufficiently accurate to predict statistics of action potential generation in some cases. The objective of this study was to develop a framework for analyzing the inaccuracies and determining their origin. Simulations of a patch of membrane with voltage-gated sodium and potassium channels were performed using an exact algorithm for the kinetics of channel gating and the approximate algorithm of Fox & Lu. The Fox & Lu algorithm assumes that channel gating particle dynamics have a stochastic term that is uncorrelated, zero-mean Gaussian noise, whereas the results of this study demonstrate that in many cases the stochastic term in the Fox & Lu algorithm should be correlated and non-Gaussian noise with a non-zero mean. The results indicate that: (i) the source of the inaccuracy is that the Fox & Lu algorithm does not adequately describe the combined behavior of the multiple activation particles in each sodium and potassium channel, and (ii) the accuracy does not improve with increasing numbers of channels.

Kilometric Continuum Radiation

NASA Technical Reports Server (NTRS)

Green, James L.; Boardsen, Scott

2006-01-01

Kilometric continuum (KC) is the high frequency component (approximately 100 kHz to approximately 800 kHz) of nonthermal continuum (NTC). Unlike the lower frequency portion of NTC (approximately 5 kHz to approximately 100 kHz) whose source is around the dawn sector, the source of KC occurs at all magnetic local times. The latitudinal beaming of KC as observed by GEOTAIL is, for most events, restricted to plus or minus 15 degrees magnetic latitude. KC has been observed during periods of both low and strong geomagnetic activity, with no significant correlation of wave intensity with K(sub p), index. However statistically the maximum observed frequency of KC emission tends to increase with K(sub p) index, the effect is more pronounced around solar maximum, but is also detected near solar minimum. There is strong evidence that the source region of KC is from the equatorial plasmapause during periods when a portion of the plasmapause moves significantly inwards from its nominal position. Case studies have shown that KC emissions are nearly always associated with plasmaspheric notches, shoulders, and tails. There is a recent focus on trying to understand the banded frequency structure of this emission and its relationship to plasmaspheric density ducts and irregularities in the source region.

Production of interferon-alpha in high cell density cultures of recombinant Escherichia coli and its single step purification from refolded inclusion body proteins.

PubMed

Babu, K R; Swaminathan, S; Marten, S; Khanna, N; Rinas, U

2000-06-01

Escherichia coli TG1 transformed with a temperature-regulated interferon-alpha expression vector was grown to high cell density in defined medium containing glucose as the sole carbon and energy source, utilizing a simple fed-batch process. Feeding was carried out to achieve an exponential increase in biomass at growth rates which minimized acetate production. Thermal induction of such high cell density cultures resulted in the production of approximately 4 g interferon-alpha/l culture broth. Interferon-alpha was produced exclusively in the form of insoluble inclusion bodies and was solubilized under denaturing conditions, refolded in the presence of arginine and purified to near homogeneity, utilizing single-step ion-exchange chromatography on Q-Sepharose. The yield of purified interferon-alpha was approximately 300 mg/l with respect to the original high cell density culture broth (overall yield of approximately 7.5% active interferon-alpha). The purified recombinant interferon-alpha was found by different criteria to be predominantly monomeric and possessed a specific bioactivity of approximately 2.5 x 10(8) IU/mg based on viral cytopathic assay.

The mechanism of the calorigenic action of thyroid hormone. Stimulation of Na plus + K plus-activated adenosinetriphosphatase activity.

PubMed

Ismail-Beigi, F; Edelman, I S

1971-06-01

In an earlier study, we proposed that thyroid hormone stimulation of energy utilization by the Na(+) pump mediates the calorigenic response. In this study, the effects of triiodothyronine (T(3)) on total oxygen consumption (Q(OO2)), the ouabain-sensitive oxygen consumption [Q(OO2)(t)], and NaK-ATPase in liver, kidney, and cerebrum were measured. In liver, approximately 90% of the increase in Q(OO2) produced by T(3) in either thyroidectomized or euthyroid rats was attributable to the increase in Q(OO2)(t). In kidney, the increase in Q(OO2)(t) accounted for 29% of the increase in Q(OO2) in thyroidectomized and 46% of the increase in Q(OO2) in euthyroid rats. There was no demonstrable effect of T(3) in euthyroid rats on Q(OO2) or Q(OO2)(t) of cerebral slices. The effects of T(3) on NaK-ATPase activity in homogenates were as follows: In liver +81% from euthyroid rats and +54% from hypothyroid rats. In kidney, +21% from euthyroid rats and +69% from hypothyroid rats. T(3) in euthyroid rats produced no significant changes in NaK-ATPase or Mg-ATPase activity of cerebral homogenates. Liver plasma membrane fractions showed a 69% increase in NaK-ATPase and no significant changes in either Mg-ATPase or 5'-nucleotidase activities after T(3) injection. These results indicate that thyroid hormones stimulate NaK-ATPase activity differentially. This effect may account, at least in part, for the calorigenic effects of these hormones.

Modulation of the reaction cycle of the Na+:Ca2+, K+ exchanger.

PubMed

Vedovato, Natascia; Rispoli, Giorgio

2007-09-01

Ca(2+) concentration in retinal photoreceptor rod outer segment (OS) strongly affects the generator potential kinetics and the receptor light adaptation. The response to intense light stimuli delivered in the dark produce potential changes exceeding 40 mV: since the Ca(2+) extrusion in the OS is entirely controlled by the Na(+):Ca(2+), K(+) exchanger, it is important to assess how the exchanger ion transport rate is affected by the voltage and, in general, by intracellular factors. It is indeed known that the cardiac Na(+):Ca(2+) exchanger is regulated by Mg-ATP via a still unknown metabolic pathway. In the present work, the Na(+):Ca(2+), K(+) exchanger regulation was investigated in isolated OS, recorded in whole-cell configuration, using ionic conditions that activated maximally the exchanger in both forward and reverse mode. In all species examined (amphibia: Rana esculenta and Ambystoma mexicanum; reptilia: Gecko gecko), the forward (reverse) exchange current increased about linearly for negative (positive) voltages and exhibited outward (inward) rectification for positive (negative) voltages. Since hyperpolarisation increases Ca(2+) extrusion rate, the recovery of the dark level of Ca(2+) (and, in turn, of the generator potential) after intense light stimuli results accelerated. Mg-ATP increased the size of forward and reverse exchange current by a factor of approximately 2.3 and approximately 2.6, respectively, without modifying their voltage dependence. This indicates that Mg-ATP regulates the number of active exchanger sites and/or the exchanger turnover number, although via an unknown mechanism.

Differential phosphorylation of azidothymidine, dideoxycytidine, and dideoxyinosine in resting and activated peripheral blood mononuclear cells.

PubMed Central

Gao, W Y; Shirasaka, T; Johns, D G; Broder, S; Mitsuya, H

1993-01-01

The antiviral activity of azidothymidine (AZT), dideoxycytidine (ddC), and dideoxyinosine (ddI) against HIV-1 was comparatively evaluated in PHA-stimulated PBM. The mean drug concentration which yielded 50% p24 Gag negative cultures were substantially different: 0.06, 0.2, and 6 microM for AZT, ddC, and ddI, respectively. We found that AZT was preferentially phosphorylated to its triphosphate (TP) form in PHA-PBM rather than unstimulated, resting PBM (R-PBM), producing 10- to 17-fold higher ratios of AZTTP/dTTP in PHA-PBM than in R-PBM. The phosphorylation of ddC and ddI to their TP forms was, however, much less efficient in PHA-PBM, resulting in approximately 5-fold and approximately 15-fold lower ratios of ddCTP/dCTP and ddATP/dATP, respectively, in PHA-PBM than in R-PBM. The comparative order of PHA-induced increase in cellular enzyme activities examined was: thymidine kinase > uridine kinase > deoxycytidine kinase > adenosine kinase > 5'-nucleotidase. We conclude that AZT, ddC, and ddI exert disproportionate antiviral effects depending on the activation state of the target cells, i.e., ddI and ddC exert antiviral activity more favorably in resting cells than in activated cells, while AZT preferentially protects activated cells against HIV infection. Considering that HIV-1 proviral DNA synthesis in resting lymphocytes is reportedly initiated at levels comparable with those of activated lymphocytes, the current data should have practical relevance in the design of anti-HIV chemotherapy, particularly combination chemotherapy. PMID:8387546

Angiotensin II stimulates calcium-dependent activation of c-Jun N-terminal kinase.

PubMed Central

Zohn, I E; Yu, H; Li, X; Cox, A D; Earp, H S

1995-01-01

In GN4 rat liver epithelial cells, angiotensin II (Ang II) and other agonists which activate phospholipase C stimulate tyrosine kinase activity in a calcium-dependent, protein kinase C (PKC)-independent manner. Since Ang II also produces a proliferative response in these cells, we investigated downstream signaling elements traditionally linked to growth control by tyrosine kinases. First, Ang II, like epidermal growth factor (EGF), stimulated AP-1 binding activity in a PKC-independent manner. Because increases in AP-1 can reflect induction of c-Jun and c-Fos, we examined the activity of the mitogen-activated protein (MAP) kinase family members Erk-1 and -2 and the c-Jun N-terminal kinase (JNK), which are known to influence c-Jun and c-Fos transcription. Ang II stimulated MAP kinase (MAPK) activity but only approximately 50% as effectively as EGF; again, these effects were independent of PKC. Ang II also produced a 50- to 200-fold activation of JNK in a PKC-independent manner. Unlike its smaller effect on MAPK, Ang II was approximately four- to sixfold more potent in activating JNK than EGF was. Although others had reported a lack of calcium ionophore-stimulated JNK activity in lymphocytes and several other cell lines, we examined the role of calcium in GN4 cells. The following results suggest that JNK activation in rat liver epithelial cells is at least partially Ca(2+) dependent: (i) norepinephrine and vasopressin hormones that increase inositol 1,4,5-triphosphate stimulated JNK; (ii) both thapsigargin, a compound that produces an intracellular Ca(2+) signal, and Ca(2+) ionophores stimulated a dramatic increase in JNK activity (up to 200-fold); (iii) extracellular Ca(2+) chelation with ethylene glycol tetraacetic acid (EGTA) inhibited JNK activation by ionophore and intracellular chelation with 1,2-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl-ester (BAPTA-AM) partially inhibited JNK activation by Ang II or thapsigargin; and (iv) JNK activation by Ang II was inhibited by pretreatment of cells with thapsigargin and EGTA, a procedure which depletes intracellular Ca(2+) stores. JNK activation following Ang II stimulation did not involve calmodulin; either W-7 nor calmidizolium, in concentrations sufficient to inhibit Ca(2+)/calmodulin-dependent kinase II, blocked JNK activation by Ang II. In contrast, genistein, in concentrations sufficient to inhibit Ca(2+)-dependent tyrosine phosphorylation, prevented Ang II and thapsigargin-induced JNK activation. In summary, in GN4 rat liver epithelial cells, Ang II stimulates JNK via a novel Ca(2+)-dependent pathway. The inhibition by genistein suggest that Ca(2+)-dependent tyrosine phosphorylation may modulate the JNK pathway in a cell type-specific manner, particularly in cells with a readily detectable Ca(2+)-regulated tyrosine kinase. PMID:7565768

Role of heme in intracellular trafficking of thyroperoxidase and involvement of H2O2 generated at the apical surface of thyroid cells in autocatalytic covalent heme binding.

PubMed

Fayadat, L; Niccoli-Sire, P; Lanet, J; Franc, J L

1999-04-09

Thyroperoxidase (TPO) is a glycosylated hemoprotein that plays a key role in thyroid hormone synthesis. We previously showed that in CHO cells expressing human TPO (hTPO) only 2% of synthesized hTPO reaches the cell surface. Herein, we investigated the role of heme moiety insertion in the exit of hTPO from the endoplasmic reticulum. Peroxidase activity at the cell surface and cell surface expression of hTPO were decreased by approximately 30 and approximately 80%, respectively, with succinyl acetone, an inhibitor of heme biosynthesis, and were increased by 20% with holotransferrin and aminolevulinic acid, precursors of heme biosynthesis. Results were similar with holotransferrin plus aminolevulinic acid or hemin, but hemin increased cell surface activity more efficiently (+120%) relative to the control. It had been suggested (DePillis, G., Ozaki, S., Kuo, J. M., Maltby, D. A., and Ortiz de Montellano, P. R. (1997) J. Biol. Chem. 272, 8857-8960) that covalent attachment of heme to mammalian peroxidases could be an H2O2-dependent autocatalytic processing. In our study, heme associated intracellularly with hTPO, and we hypothesized that there was insufficient exposure to H2O2 in Chinese hamster ovary cells before hTPO reached the cell surface. After a 10-min incubation, 10 microM H2O2 led to a 65% increase in cell surface activity. In contrast, in thyroid cells, H2O2 was synthesized at the apical cell surface and allowed covalent attachment of heme. Two-day incubation of primocultures of thyroid cells with catalase led to a 30% decrease in TPO activity at the cell surface. In conclusion, we provide compelling evidence for an essential role of 1) heme incorporation in the intracellular trafficking of hTPO and of 2) H2O2 generated at the apical pole of thyroid cells in the autocatalytic covalent heme binding to the TPO molecule.

In vivo antitumoral activity of stem pineapple (Ananas comosus) bromelain.

PubMed

Báez, Roxana; Lopes, Miriam T; Salas, Carlos E; Hernández, Martha

2007-10-01

Stem bromelain (EC 3.4.22.32) is a major cysteine proteinase, isolated from pineapple ( Ananas comosus) stem. Its main medicinal use is recognized as digestive, in vaccine formulation, antitumoral and skin debrider for the treatment of burns. To verify the identity of the principle in stem fractions responsible for the antitumoral effect, we isolated bromelain to probe its pharmacological effects. The isolated bromelain was obtained from stems of adult pineapple plants by buffered aqueous extraction and cationic chromatography. The homogeneity of bromelain was confirmed by reverse phase HPLC, SDS-PAGE and N-terminal sequencing. The in vivo antitumoral/antileukemic activity was evaluated using the following panel of tumor lines: P-388 leukemia, sarcoma (S-37), Ehrlich ascitic tumor (EAT), Lewis lung carcinoma (LLC), MB-F10 melanoma and ADC-755 mammary adenocarcinoma. Intraperitoneal administration of bromelain (1, 12.5, 25 mg/kg), began 24 h after tumor cell inoculation in experiments in which 5-fluorouracil (5-FU, 20 mg/kg) was used as positive control. The antitumoral activity was assessed by the survival increase (% survival index) following various treatments. With the exception of MB-F10 melanoma, all other tumor-bearing animals had a significantly increased survival index after bromelain treatment. The largest increase ( approximately 318 %) was attained in mice bearing EAT ascites and receiving 12.5 mg/kg of bromelain. This antitumoral effect was superior to that of 5-FU, whose survival index was approximately 263 %, relative to the untreated control. Bromelain significantly reduced the number of lung metastasis induced by LLC transplantation, as observed with 5-FU. The antitumoral activity of bromelain against S-37 and EAT, which are tumor models sensitive to immune system mediators, and the unchanged tumor progression in the metastatic model suggests that the antimetastatic action results from a mechanism independent of the primary antitumoral effect.

Removal of triclosan in nitrifying activated sludge: effects of ammonia amendment and bioaugmentation.

PubMed

Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

2015-04-01

This study investigated two possible strategies, increasing ammonia oxidation activity and bioaugmenting with triclosan-degrader Sphingopyxis strain KCY1, to enhance triclosan removal in nitrifying activated sludge (NAS). Triclosan (2 mg L(-1)) was removed within 96-h in NAS bioreactors amended with 5, 25 and 75 mg L(-1) of ammonium (NH4-N). The fastest triclosan removal was observed in 25 mg NH4-NL(-1) amended-bioreactors where high ammonia oxidation occurred. Inhibition of ammonia oxidation and slower triclosan removal were observed in 75 mg NH4-NL(-1) amended-bioreactors. Triclosan removal was correlated to the molar ratio of the amount of nitrate produced to the amount of ammonium removed. Bioaugmentation with strain KCY1 did not enhance triclosan removal in the bioreactors with active ammonia oxidation. Approximately 36-42% and 59% of triclosan added were removed within 24-h by ammonia-oxidizing bacteria and unknown triclosan-degrading heterotrophs, respectively. The results suggested that increasing ammonia oxidation activity can be an effective strategy to enhance triclosan removal in NAS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationship of gastric myoelectrical and cardiac parasympathetic activity to chemotherapy-induced nausea

PubMed Central

Gianaros, Peter J.; Stern, Robert M.; Morrow, Gary R.; Hickok, Jane T.

2010-01-01

Objectives We evaluated (a) whether pretreatment levels of gastric tachyarrhythmia, a dysrhythmic pattern of gastric myoelectrical activity, or cardiac parasympathetic activity are associated with the development of chemotherapy-induced nausea and (b) whether chemotherapy-induced nausea is preceded by an increase in gastric tachyarrhythmia and a decrease in cardiac parasympathetic activity, as has been observed during motion sickness. Methods Electrogastrograms and estimates of respiratory sinus arrhythmia (RSA) were obtained from cancer chemotherapy patients before treatment and for approximately 24 hours after treatment. Results Higher levels of pretreatment gastric tachyarrhythmia were observed on chemotherapy sessions that were followed by posttreatment reports of nausea. Pretreatment levels of RSA, however, did not differ between chemotherapy treatments that were and were not followed by nausea. No statistically significant changes in gastric tachyarrhythmia or RSA were observed prior to first reports of nausea following chemotherapy. Conclusions In contrast to motion sickness, chemotherapy-induced nausea may not be related to an increase in dysrhythmic gastric myoelectrical activity; however, higher levels of pretreatment gastric tachyarrhythmia may be related to posttreatment reports of chemotherapy-induced nausea. PMID:11399283

Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells.

PubMed

Neufurth, Meik; Wang, Xiaohong; Schröder, Heinz C; Feng, Qingling; Diehl-Seifert, Bärbel; Ziebart, Thomas; Steffen, Renate; Wang, Shunfeng; Müller, Werner E G

2014-10-01

Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca(2+)-complex], resulted in a marked increase in cell proliferation. In the presence of 100 μm polyP·Ca(2+)-complex, the cells proliferate with a generation time of approximately 47-55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially increases in the presence of the polymer. The reduced Young's modulus for the alginate/gelatin hydrogel is approximately 13-14 kPa, and this value drops to approximately 0.5 kPa after incubation of the cell containing scaffolds for 5 d. In the presence of 100 μm polyP·Ca(2+)-complex, the reduced Young's modulus increases to about 22 kPa. The hardness of the polyP·Ca(2+)-complex containing hydrogel remains essentially constant if cells are absent in the matrix, but it drops to 3.2 kPa after a 5 d incubation period in the presence of SaOS-2 cells, indicating that polyP·Ca(2+)-complex becomes metabolized, degraded, by the cells. The alginate/gelatine-agarose system with polyP·Ca(2+)-complex cause a significant increase in the mineralization of the cells. SEM analyses revealed that the morphology of the mineral nodules formed on the surface of the cells embedded in the alginate/gelatin hydrogel do not significantly differ from the nodules on cells growing in monolayer cultures. The newly developed technique, using cells encapsulated into an alginate/gelatin hydrogel and a secondary layer containing the morphogenetically active, growth promoting polymer polyP·Ca(2+)-complex opens new possibilities for the application of 3D bioprinting in bone tissue engineering. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fiber type-specific afferent nerve activity induced by transient contractions of rat bladder smooth muscle in pathological states

PubMed Central

Kuga, Nahoko; Tanioka, Asao; Hagihara, Koichiro; Kawai, Tomoyuki

2017-01-01

Bladder smooth muscle shows spontaneous phasic contractions, which undergo a variety of abnormal changes depending on pathological conditions. How abnormal contractions affect the activity of bladder afferent nerves remains to be fully tested. In this study, we examined the relationship between transient increases in bladder pressure, representing transient contraction of bladder smooth muscle, and spiking patterns of bladder afferent fibers of the L6 dorsal root, in rat pathological models. All recordings were performed at a bladder pressure of approximately 10 cmH2O by maintaining the degree of bladder filling. In the cyclophosphamide-induced model, both Aδ and C fibers showed increased sensitivity to transient bladder pressure increases. In the prostaglandin E2-induced model, Aδ fibers, but not C fibers, specifically showed overexcitation that was time-locked with transient bladder pressure increases. These fiber type-specific changes in nerve spike patterns may underlie the symptoms of urinary bladder diseases. PMID:29267380

Age-associated changes in muscle activity during isometric contraction.

PubMed

Arjunan, Sridhar P; Kumar, Dinesh K

2013-04-01

We investigated the effect of age on the complexity of muscle activity and the variance in the force of isometric contraction. Surface electromyography (sEMG) from biceps brachii muscle and force of contraction were recorded from 96 subjects (20-70 years of age) during isometric contractions. There was a reduction in the complexity of sEMG associated with aging. The relationship of age and complexity was approximated using a bilinear fit, with the average knee point at 45 years. There was an age-associated increase in the coefficient of variation (CoV) of the force of muscle contraction, and this increase was correlated with the decrease in complexity of sEMG (r(2) = 0.76). There was an age-associated increase in CoV and also a reduction in the complexity of sEMG. The correlation between these 2 factors can be explained based on the age-associated increase in motor unit density. Copyright © 2012 Wiley Periodicals, Inc.

Metal and hydrocarbon behavior in sediments from Brazilian shallow waters drilling activities using nonaqueous drilling fluids (NAFs).

PubMed

do Carmo R Peralba, Maria; Pozebon, Dirce; dos Santos, João H Z; Maia, Sandra M; Pizzolato, Tânia M; Cioccari, Giovani; Barrionuevo, Simone

2010-08-01

The impact of drilling oil activities in the Brazilian Bonito Field/Campos Basin (Rio de Janeiro) shell drilling (300 m) using nonaqueous fluids (NAFs) was investigated with respect to Al, Fe, Mn, Ba, Co, Pb, Cu, As, Hg, Cr, Ni, Zn, Cd, V, and aliphatic and polynuclear aromatic hydrocarbons concentrations in the sediment. Sampling took place in three different times during approximately 33 months. For the metals Al, As, Co, Cr, Cu, Cd, Fe, Ni, Mn, V, and Zn, no significant variation was observed after drilling activities in most of the stations. However, an increase was found in Ba concentration--due to the drilling activity--without return to the levels found 22 months after drilling. High Ba contents was already detected prior to well drilling, probably due to drilling activities in other wells nearby. Hydrocarbon contents also suggest previous anthropogenic activities. Aliphatic hydrocarbon contents were in the range usually reported in other drilling sites. The same behavior was observed in the case of polyaromatic hydrocarbons. Nevertheless, the n-alkane concentration increased sharply after drilling, returning almost to predrilling levels 22 months after drilling activities.

The Nrf1 CNC-bZIP protein is regulated by the proteasome and activated by hypoxia.

PubMed

Chepelev, Nikolai L; Bennitz, Joshua D; Huang, Ting; McBride, Skye; Willmore, William G

2011-01-01

Nrf1 (nuclear factor-erythroid 2 p45 subunit-related factor 1) is a transcription factor mediating cellular responses to xenobiotic and pro-oxidant stress. Nrf1 regulates the transcription of many stress-related genes through the electrophile response elements (EpREs) located in their promoter regions. Despite its potential importance in human health, the mechanisms controlling Nrf1 have not been addressed fully. We found that proteasomal inhibitors MG-132 and clasto-lactacystin-β-lactone stabilized the protein expression of full-length Nrf1 in both COS7 and WFF2002 cells. Concomitantly, proteasomal inhibition decreased the expression of a smaller, N-terminal Nrf1 fragment, with an approximate molecular weight of 23 kDa. The EpRE-luciferase reporter assays revealed that proteasomal inhibition markedly inhibited the Nrf1 transactivational activity. These results support earlier hypotheses that the 26 S proteasome processes Nrf1 into its active form by removing its inhibitory N-terminal domain anchoring Nrf1 to the endoplasmic reticulum. Immunoprecipitation demonstrated that Nrf1 is ubiquitinated and that proteasomal inhibition increased the degree of Nrf1 ubiquitination. Furthermore, Nrf1 protein had a half-life of approximately 5 hours in COS7 cells. In contrast, hypoxia (1% O(2)) significantly increased the luciferase reporter activity of exogenous Nrf1 protein, while decreasing the protein expression of p65, a shorter form of Nrf1, known to act as a repressor of EpRE-controlled gene expression. Finally, the protein phosphatase inhibitor okadaic acid activated Nrf1 reporter activity, while the latter was repressed by the PKC inhibitor staurosporine. Collectively, our data suggests that Nrf1 is controlled by several post-translational mechanisms, including ubiquitination, proteolytic processing and proteasomal-mediated degradation as well as by its phosphorylation status. © 2011 Chepelev et al.

Study on Current Levels of Physical Activity and Sedentary Behavior among Middle School Students in Beijing, China

PubMed Central

Duan, Jiali; Hu, Huanhuan; Wang, Guan; Arao, Takashi

2015-01-01

Introduction This study aimed to determine current levels of physical activity and sedentary behavior in middle school students on the basis of grade, sex, student attitudes toward physical education, and residence location. Methods In 2013, a cross-sectional study of 1793 students aged 12 to 15 years was conducted across eight middle schools in Beijing, China. Four schools were selected from an urban district and another four schools were from a suburban district. Physical activity and sedentary behavior data were collected using the commonly used school-based Chinese version of the China Health and Nutrition Survey. Results The mean age of sampled students was 13.3±1.0 years; 51.5% were boys. Approximately 76.6% of students reported having three 45-minute physical education classes every week. A total of 35.6% students spent ≥1 h/day performing moderate to vigorous physical activity (MVPA) during school, and 34.9% spent ≥1 h/day in MVPA outside school time. Approximately half (49.7%) of the students engaged in reading, writing, or drawing for ≥2 h/day, and 42.9% reported screen time for ≥2 h/day. Although boys spent more time engaged in physical activity than girls did, they also spent more time exhibiting sedentary behavior. Each 10-unit increase in attitudes toward physical education was associated with an increased odds of 1.15 (95%CI: 1.09–1.20) for spending more than 1 h/day on MVPA. Students in suburban schools reported engaging in physical activity less when compared with those in urban schools. Conclusion The majority of our students did not meet the current physical activity recommendations, and about half of the students spent excessive time engaging in sedentary behaviors. Findings from this study highlight a positive association between student attitudes toward physical education and physical activity. Studies are needed to further explore the role of student attitudes toward physical education in promoting physical activity among Chinese students. PMID:26181052

NBD-labelled phospholipid accelerates apolipoprotein C-II amyloid fibril formation but is not incorporated into mature fibrils

PubMed Central

Ryan, Timothy M.; Griffin, Michael D. W.; Bailey, Michael F.; Schuck, Peter; Howlett, Geoffrey J.

2014-01-01

Human apolipoprotein (apo) C-II is one of several lipid-binding proteins that self-assemble into fibrils and accumulate in disease-related amyloid deposits. A general characteristic of these amyloid deposits is the presence of lipids, known to modulate individual steps in amyloid fibril formation. ApoC-II fibril formation is activated by sub-micellar phospholipids but inhibited by micellar lipids. We examined the mechanism for the activation by sub-micellar lipids using the fluorescently-labelled, short-chain phospholipid, 1-dodecyl-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]-2-hydroxy-glycero-3-phosphocholine (NBD-lyso-12-PC). Addition of submicellar NBD-lyso-12-PC increased the rate of fibril formation by apoC-II approximately two-fold. Stopped flow kinetic analysis using fluorescence detection and low, non-fibril forming concentrations of apoC-II indicated NBD-Lyso-12-PC binds rapidly, in the millisecond timescale, followed by the slower formation of discrete apoC-II tetramers. Sedimentation velocity analysis showed NBD-Lyso-12-PC binds to both apoC-II monomers and tetramers at approximately 5 sites per monomer with an average dissociation constant of approximately 10 μM. Mature apoC-II fibrils formed in the presence of NBD-Lyso-12-PC were devoid of lipid indicating a purely catalytic role for sub-micellar lipids in the activation of apoC-II fibril formation. These studies demonstrate the catalytic potential of small amphiphilic molecules to control protein folding and fibril assembly pathways. PMID:21985034

Assessing the Effectiveness of Risk Communication for Maintenance Workers Who Deal With Induced Radioactivity Management of Medical Linear Accelerators.

PubMed

Watanabe, Hiroshi; Maehara, Yoshiaki; Fujibuchi, Toshioh; Koizumi, Mitsue; Yamaguchi, Ichiro; Kida, Tetsuo; Ooyama, Masaya; Horitsugi, Genki; Hiraki, Hitoshi; Tsukamoto, Atsuko; Itami, Jyun

2015-08-01

In Japan, an amended law that mandates levels of unintended induced radioactivity has been in effect since 1 April 2012. According to the new regulation, if the concentration of induced radioactivity in affected parts is above the clearance level, the parts must be regarded as radioactive even if they weigh less than 1 kg. This regulation reform raises several new issues concerning medical linear accelerators, including how to determine the decay period for induced radioactivity before maintenance can be performed and how to identify what parts should be considered radioactive waste. The authors performed several risk communication (RC) activities aimed at improving the understanding of maintenance workers at medical accelerator manufacturers and establishing good guidelines by involving stakeholders. For this purpose, a working group was established and conducted RC activities, such as holding opinion exchange meetings between medical staff and maintenance workers and creating a booklet to answer questions from maintenance workers. To evaluate these activities, three questionnaire surveys were conducted between 2011 and 2014. According to the results of this study, the ratio of maintenance workers who accepted "The decay period is within one week" was approximately 60% at the third survey and significantly increased (P < 0.0001) during the survey period. Approximately 25% of the maintenance workers felt that not enough information was provided about the decay period, and approximately 63% thought that the information provided on the health effects of radiation was sufficient. These results suggest that the present RC was successful.

Watermelon (Citrullus lanatus) hydroperoxide lyase greatly increases C6 aldehyde formation in transgenic leaves.

PubMed

Fukushige, Hirotada; Hildebrand, David F

2005-03-23

Fatty acid hydroperoxide lyase (HL) is the key enzyme for the production of the "green note"compounds, leaf aldehyde [(2E)-hexenal] and leaf alcohol [(3Z)-hexenol], in plant tissues. A cDNA encoding HL was cloned from leaves of watermelon (Citrullus lanatus) and expressed in Nicotiana tabacum. The enzyme is 3 times more active with 13-hydroperoxylinolenic acid than with 13-hydroperoxylinoleic acid. The activity against 9-hydroperoxides of polyunsaturated fatty acids is minimal. Enzyme activity of the watermelon HL in the transgenic leaves was approximately 50 times higher than endogenous HL activity in the wild-type N. tabacum plants. When compared with Arabidopsis HL also expressed in N. tabacum, the highest HL activity is 10 times higher in watermelon HL overexpressing leaves than in Arabidopsis HL overexpressers.

Effects of Δ9-THC and cannabidiol vapor inhalation in male and female rats.

PubMed

Javadi-Paydar, Mehrak; Nguyen, Jacques D; Kerr, Tony M; Grant, Yanabel; Vandewater, Sophia A; Cole, Maury; Taffe, Michael A

2018-06-16

Previous studies report sex differences in some, but not all, responses to cannabinoids in rats. The majority of studies use parenteral injection; however, most human use is via smoke inhalation and, increasingly, vapor inhalation. To compare thermoregulatory and locomotor responses to inhaled ∆ 9 -tetrahydrocannabinol (THC), cannabidiol (CBD), and their combination using an e-cigarette-based model in male and female rats METHODS: Male and female Wistar rats were implanted with radiotelemetry devices for the assessment of body temperature and locomotor activity. Animals were then exposed to THC or CBD vapor using a propylene glycol (PG) vehicle. THC dose was adjusted via the concentration in the vehicle (12.5-200 mg/mL) and the CBD (100, 400 mg/mL) dose was also adjusted by varying the inhalation duration (10-40 min). Anti-nociception was evaluated using a tail-withdrawal assay following vapor inhalation. Plasma samples obtained following inhalation in different groups of rats were compared for THC content. THC inhalation reduced body temperature and increased tail-withdrawal latency in both sexes equivalently and in a concentration-dependent manner. Female temperature, activity, and tail-withdrawal responses to THC did not differ between estrus and diestrus. CBD inhalation alone induced modest hypothermia and suppressed locomotor activity in both males and females. Co-administration of THC with CBD, in a 1:4 ratio, significantly decreased temperature and activity in an approximately additive manner and to similar extent in each sex. Plasma THC varied with the concentration in the PG vehicle but did not differ across rat sex. In summary, the inhalation of THC or CBD, alone and in combination, produces approximately equivalent effects in male and female rats. This confirms the efficacy of the e-cigarette-based method of THC delivery in female rats.

Mechanisms of acquired resistance to the quinazoline thymidylate synthase inhibitor ZD1694 (Tomudex) in one mouse and three human cell lines.

PubMed Central

Jackman, A. L.; Kelland, L. R.; Kimbell, R.; Brown, M.; Gibson, W.; Aherne, G. W.; Hardcastle, A.; Boyle, F. T.

1995-01-01

Four cell lines, the mouse L1210 leukaemia, the human W1L2 lymphoblastoid and two human ovarian (CH1 and 41M) cell lines, were made resistant to ZD1694 (Tomudex) by continual exposure to incremental doses of the drug. A 500-fold increase in thymidylate synthase (TS) activity is the primary mechanism of resistance to ZD1694 in the W1L2:RD1694 cell line, which is consequently highly cross-resistant to other folate-based TS inhibitors, including BW1843U89, LY231514 and AG337, but sensitive to antifolates with other enzyme targets. The CH1:RD1694 cell line is 14-fold resistant to ZD1694, largely accounted for by the 4.2-fold increase in TS activity. Cross-resistance was observed to other TS inhibitors, including 5-fluorodeoxyuridine (FdUrd). 41M:RD1694 cells, when exposed to 0.1 microM [3H]ZD1694, accumulated approximately 20-fold less 3H-labelled material over 24 h than the parental line. Data are consistent with this being the result of impaired transport of the drug via the reduced folate/methotrexate carrier. Resistance was therefore observed to methotrexate but not to CB3717, a compound known to use this transport mechanism poorly. The mouse L1210:RD1694 cell line does not accumulate ZD1694 or Methotrexate (MTX) polyglutamates. Folylpolyglutamate synthetase substrate activity (using ZD1694 as the substrate) was decreased to approximately 13% of that observed in the parental line. Cross-resistance was found to those compounds known to be active through polyglutamation. PMID:7537518

Up-regulation of phosphoinositide metabolism in tobacco cells constitutively expressing the human type I inositol polyphosphate 5-phosphatase

NASA Technical Reports Server (NTRS)

Perera, Imara Y.; Love, John; Heilmann, Ingo; Thompson, William F.; Boss, Wendy F.; Brown, C. S. (Principal Investigator)

2002-01-01

To evaluate the impact of suppressing inositol 1,4,5-trisphosphate (InsP(3)) in plants, tobacco (Nicotiana tabacum) cells were transformed with the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase), an enzyme which specifically hydrolyzes InsP(3). The transgenic cell lines showed a 12- to 25-fold increase in InsP 5-ptase activity in vitro and a 60% to 80% reduction in basal InsP(3) compared with wild-type cells. Stimulation with Mas-7, a synthetic analog of the wasp venom peptide mastoparan, resulted in an approximately 2-fold increase in InsP(3) in both wild-type and transgenic cells. However, even with stimulation, InsP(3) levels in the transgenic cells did not reach wild-type basal values, suggesting that InsP(3) signaling is compromised. Analysis of whole-cell lipids indicated that phosphatidylinositol 4,5-bisphosphate (PtdInsP(2)), the lipid precursor of InsP(3), was greatly reduced in the transgenic cells. In vitro assays of enzymes involved in PtdInsP(2) metabolism showed that the activity of the PtdInsP(2)-hydrolyzing enzyme phospholipase C was not significantly altered in the transgenic cells. In contrast, the activity of the plasma membrane PtdInsP 5 kinase was increased by approximately 3-fold in the transgenic cells. In vivo labeling studies revealed a greater incorporation of (32)P into PtdInsP(2) in the transgenic cells compared with the wild type, indicating that the rate of PtdInsP(2) synthesis was increased. These studies show that the constitutive expression of the human type I InsP 5-ptase in tobacco cells leads to an up-regulation of the phosphoinositide pathway and highlight the importance of PtdInsP(2) synthesis as a regulatory step in this system.

Up-Regulation of Phosphoinositide Metabolism in Tobacco Cells Constitutively Expressing the Human Type I Inositol Polyphosphate 5-Phosphatase1

PubMed Central

Perera, Imara Y.; Love, John; Heilmann, Ingo; Thompson, William F.; Boss, Wendy F.

2002-01-01

To evaluate the impact of suppressing inositol 1,4,5-trisphosphate (InsP3) in plants, tobacco (Nicotiana tabacum) cells were transformed with the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase), an enzyme which specifically hydrolyzes InsP3. The transgenic cell lines showed a 12- to 25-fold increase in InsP 5-ptase activity in vitro and a 60% to 80% reduction in basal InsP3 compared with wild-type cells. Stimulation with Mas-7, a synthetic analog of the wasp venom peptide mastoparan, resulted in an approximately 2-fold increase in InsP3 in both wild-type and transgenic cells. However, even with stimulation, InsP3 levels in the transgenic cells did not reach wild-type basal values, suggesting that InsP3 signaling is compromised. Analysis of whole-cell lipids indicated that phosphatidylinositol 4,5-bisphosphate (PtdInsP2), the lipid precursor of InsP3, was greatly reduced in the transgenic cells. In vitro assays of enzymes involved in PtdInsP2 metabolism showed that the activity of the PtdInsP2-hydrolyzing enzyme phospholipase C was not significantly altered in the transgenic cells. In contrast, the activity of the plasma membrane PtdInsP 5 kinase was increased by approximately 3-fold in the transgenic cells. In vivo labeling studies revealed a greater incorporation of 32P into PtdInsP2 in the transgenic cells compared with the wild type, indicating that the rate of PtdInsP2 synthesis was increased. These studies show that the constitutive expression of the human type I InsP 5-ptase in tobacco cells leads to an up-regulation of the phosphoinositide pathway and highlight the importance of PtdInsP2 synthesis as a regulatory step in this system. PMID:12177493

Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

PubMed

Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

2007-01-01

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

``Sleeping reactor`` irradiations: Shutdown reactor determination of short-lived activation products

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

Jerde, E.A.; Glasgow, D.C.

1998-09-01

At the High-Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, the principal irradiation system has a thermal neutron flux ({phi}) of {approximately} 4 {times} 10{sup 14} n/cm{sup 2} {center_dot} s, permitting the detection of elements via irradiation of 60 s or less. Irradiations of 6 or 7 s are acceptable for detection of elements with half-lives of as little as 30 min. However, important elements such as Al, Mg, Ti, and V have half-lives of only a few minutes. At HFIR, these can be determined with irradiation times of {approximately} 6 s, but the requirement of immediate countingmore » leads to increased exposure to the high activity produced by irradiation in the high flux. In addition, pneumatic system timing uncertainties (about {+-} 0.5 s) make irradiations of < 6 s less reliable. Therefore, the determination of these ultra-short-lived species in mixed matrices has not generally been made at HFIR. The authors have found that very short lived activation products can be produced easily during the period after reactor shutdown (SCRAM), but prior to the removal of spent fuel elements. During this 24- to 36-h period (dubbed the ``sleeping reactor``), neutrons are produced in the beryllium reflector by the reaction {sup 9}Be({gamma},n){sup 8}Be, the gamma rays principally originating in the spent fuel. Upon reactor SCRAM, the flux drops to {approximately} 1 {times} 10{sup 10} n/cm{sup 2} {center_dot} s within 1 h. By the time the fuel elements are removed, the flux has dropped to {approximately} 6 {times} 10{sup 8}. Such fluxes are ideal for the determination of short-lived elements such as Al, Ti, Mg, and V. An important feature of the sleeping reactor is a flux that is not constant.« less

Ischemia/reperfusion-induced injury of forebrain mitochondria and protection by ascorbate.

PubMed

Sciamanna, M A; Lee, C P

1993-09-01

Complete, reversible forebrain ischemia was induced with a seven-vessel occlusion rat model. Previous studies of ischemic (M. A. Sciamanna, J. Zinkel, A. Y. Fabi, and C. P. Lee, 1992, Biochim. Biophys. Acta 1134, 223-232) rat brain mitochondria (RBM) showed that ischemia of 30 min caused an approximately 60% decrease in State 3 respiratory rates with both succinate and NAD-linked substrates and also in energy-linked Ca2+ transport. No significant change was seen in the State 4 rates. The inhibition of respiration could be prevented by EGTA or ruthenium red. In this paper it is shown that reperfusion (5 h) following ischemia (30 min) further impaired RBM respiratory activities (succinate and NAD-linked substrates). The presence of EGTA or ruthenium red in the assay medium did not protect against ischemia/reperfusion-induced injury. The effects of ascorbate, an oxygen radical scavenger, were studied. RBM isolated from ascorbate-treated animals (0.8 mg ascorbate/kg body weight) after ischemia (30 min) alone showed only a slight increase in State 3 (approximately 25%) and a decrease in State 4 (approximately 20%) activities with succinate, when compared to untreated 30-min ischemic animals, whereas, with glutamate+malate little or no effect was seen. The respiratory activities of RBM from ascorbate-treated, ischemic/reperfused (30 min/5 h) rats were restored to approximately 65% of controls levels. Ascorbate protection was dose-dependent with maximum protection at 0.8 mg ascorbate/kg body weight of rat. The k of succinate oxidase-supported Ca2+ uptake also returned to 62% of control values. Protection by ascorbate was most effective when administered prior to the onset of ischemia and provided partial protection when administered after the onset of reperfusion. These results suggest that ischemia-induced injury is primarily mediated by disruption of cellular Ca2+ homeostasis, and reperfusion-induced injury by peroxidative events.

Evaluation of an employer-sponsored pedometer-based physical activity program.

PubMed

Behrens, Timothy K; Domina, Lorie; Fletcher, Gena M

2007-12-01

This study evaluated a competition-based employer-sponsored physical activity program using pedometers. City employees (N approximately 2,600) formed teams in groups of 10 persons (N = 640). The groups competed against each other over a 12-wk. period with the goal of attaining 10,000 steps per day, per person. Only teams with complete data were included in the formal evaluation. A repeated-measures analysis of variance indicated significant differences in team steps by week of the program, with post hoc comparisons indicating significant differences from baseline step counts evident during Weeks 6-8 but not at the end of the program. These data confirm that competition-based physical activity programs using pedometers may not be an effective means of increasing the long-term physical activity of employees.

Increased Activity of [gamma]-Glutamylcysteine Synthetase in Tomato Cells Selected for Cadmium Tolerance.

PubMed

Chen, J.; Goldsbrough, P. B.

1994-09-01

Two cell lines of tomato (Lycopersicon esculentum Mill cv VFNT-Cherry) were systematically compared for their capacity to tolerate cadmium. Unselected CdS cells died in the presence of 0.3 mM CdCl2. CdR6-0 cells, which were selected from CdS, survived and grew in medium supplemented with 0.3 mM CdCl2. Growth of CdR6-0 cells under this condition was accompanied by synthesis of cadmium-binding phytochelatins and maintenance of cellular glutathione (GSH) levels. CdR6-0 cells also exhibited increased tolerance to buthionine sulfoximine, in both the presence and absence of 0.1 mM CdCl2. The specific activity of [gamma]-glutamylcysteine synthetase (EC 6.3.2.2) was approximately 2-fold higher in CdR6-0 cells than in CdS cells, whereas there was no difference between cell lines in specific activity of GSH synthetase (EC 6.3.2.3). Increased activity of the first enzyme of GSH biosynthesis in CdR6-0 cells, presumably a result of selection for increased cadmium tolerance, provides an enhanced capacity to synthesize GSH and to maintain the production of phytochelatins in response to cadmium. This adaptation may contribute to the enhanced cadmium tolerance of CdR6-0 cells.

Electromyographic reflexes evoked in human flexor carpi radialis by tendon vibration.

PubMed

Cody, F W; Goodwin, C N; Richardson, H C

1990-10-01

The rectified, electromyographic (EMG) reflexes evoked in the voluntarily contracting flexor carpi radialis (FCR) muscle by vibration of its tendon were studied in healthy human subjects. Responses comprised a prominent, transient, short-latency (SL, 20-25 ms) increase in EMG, attributed to Ia mono- and/or oligo-synaptic action, followed by a series of less pronounced troughs and peaks of activity. Evidence of continuing Ia mono- or oligo-synaptic action was indicated by (i) the presence of small subpeaks, at vibration frequency, superimposed upon the excitatory components and (ii) the occurrence of a separate reduction in EMG, of consistent latency (ca. 30 ms), after cessation of stimulation. Progressively shortening the train of vibration from 29 cycles (at 145 Hz) to a single cycle significantly reduced net, excitatory reflex activity. Gradually increasing the level (10-50% maximum) of pre-existing voluntary contraction on top of which reflexes were elicited, by moderately prolonged (29 cycles) trains of vibration, resulted in small increases, in absolute terms, in SL peaks and in later, excitatory EMG activity. Excitatory reflexes, when normalised for pre-stimulus EMG, however, declined in an approximately hyperbolic manner with increasing background activity over this range. Thus, effective "automatic gain compensation" does not operate for vibration reflexes in FCR.

Stress, Coping, and Infectious Illness: Persistently Low Natural Killer Cell Activity as a Host Risk Factor.

DTIC Science & Technology

1988-03-14

increased incidence of acute, infectious illnesses, such as upper respiratory infections and infectious mononucleosis , as well as outbreaks of herpes... infectious mononucleosis . Psychosomatic Medicine, 41. 445-466. Kemeny, M., Cohen, F., and Zegams, L., (1986). The relationship of coping strategies to...follow-up period in order to identify predictors of infectious illness over time. As in the preliminary work, we are finding that approximately 1/3 of

Application of a combined approach involving classical random mutagenesis and metabolic engineering to enhance FK506 production in Streptomyces sp. RM7011.

PubMed

Mo, SangJoon; Lee, Sung-Kwon; Jin, Ying-Yu; Oh, Chung-Hun; Suh, Joo-Won

2013-04-01

FK506 production by a mutant strain (Streptomyces sp. RM7011) induced by N-methyl-N'-nitro-N-nitrosoguanidine and ultraviolet mutagenesis was improved by 11.63-fold (94.24 mg/l) compared to that of the wild-type strain. Among three different metabolic pathways involved in the biosynthesis of methylmalonyl-CoA, only expression of propionyl-CoA carboxylase (PCC) pathway led to a 1.75-fold and 2.5-fold increase in FK506 production and the methylmalonyl-CoA pool, respectively, compared to those of the RM7011 strain. Lipase activity of the high FK506 producer mutant increased in direct proportion to the increase in FK506 yield, from low detection level up to 43.1 U/ml (12.6-fold). The level of specific FK506 production and lipase activity was improved by enhancing the supply of lipase inducers. This improvement was approximately 1.88-fold (71.5 mg/g) with the supplementation of 5 mM Tween 80, which is the probable effective stimulator in lipase production, to the R2YE medium. When 5 mM vinyl propionate was added as a precursor for PCC pathway to R2YE medium, the specific production of FK506 increased approximately 1.9-fold (71.61 mg/g) compared to that under the non-supplemented condition. Moreover, in the presence of 5 mM Tween 80, the specific FK506 production was approximately 2.2-fold (157.44 mg/g) higher than that when only vinyl propionate was added to the R2YE medium. In particular, PCC expression in Streptomyces sp. RM7011 (RM7011/pSJ1003) together with vinyl propionate feeding resulted in an increase in the FK506 titer to as much as 1.6-fold (251.9 mg/g) compared with that in RM7011/pSE34 in R2YE medium with 5 mM Tween 80 supplementation, indicating that the vinyl propionate is more catabolized to propionate by stimulated lipase activity on Tween 80, that propionyl-CoA yielded from propionate generates methylmalonyl-CoA, and that the PCC pathway plays a key role in increasing the methylmalonyl-CoA pool for FK506 biosynthesis in RM7011 strain. Overall, these results show that a combined approach involving classical random mutation and metabolic engineering can be applied to supply the limiting factor for FK506 biosynthesis, and vinyl propionate could be successfully used as a precursor of important methylmalonyl-CoA building blocks.

Crossing the LINE toward genomic instability: LINE-1 retrotransposition in cancer

NASA Astrophysics Data System (ADS)

Kemp, Jacqueline; Longworth, Michelle

2015-12-01

Retrotransposons are repetitive DNA sequences that are positioned throughout the human genome. Retrotransposons are capable of copying themselves and mobilizing new copies to novel genomic locations in a process called retrotransposition. While most retrotransposon sequences in the human genome are incomplete and incapable of mobilization, the LINE-1 retrotransposon, which comprises approximately 17% of the human genome, remains active. The disruption of cellular mechanisms that suppress retrotransposon activity is linked to the generation of aneuploidy, a potential driver of tumor development. When retrotransposons insert into a novel genomic region, they have the potential to disrupt the coding sequence of endogenous genes and alter gene expression, which can lead to deleterious consequences for the organism. Additionally, increased LINE-1 copy numbers provide more chances for recombination events to occur between retrotransposons, which can lead to chromosomal breaks and rearrangements. LINE-1 activity is increased in various cancer cell lines and in patient tissues resected from primary tumors. LINE-1 activity also correlates with increased cancer metastasis. This review aims to give a brief overview of the connections between LINE-1 retrotransposition and the loss of genome stability. We will also discuss the mechanisms that repress retrotransposition in human cells and their links to cancer.

Prostaglandin E2 stimulates a Ca2+-dependent K+ channel in human erythrocytes and alters cell volume and filterability.

PubMed

Li, Q; Jungmann, V; Kiyatkin, A; Low, P S

1996-08-02

To understand the mechanism by which human red blood cells (RBCs) contribute to hemostasis and thrombosis, we have examined the effects of metabolites released by activated platelets on intact RBCs. Prostaglandin E2 (PGE2), a signal molecule produced by activated platelets, was observed to lower the filterability of human erythrocytes by approximately 30% at 10(-10) M. PGE2 also caused a reduction in mean cell volume of approximately 10%. The shrinkage of red cells after PGE2 treatment was confirmed by documenting a decrease in osmotic fragility and an increase in cell density following exposure to the hormone. Careful analysis, however, revealed that only approximately 15% of the erythrocytes responded to stimulation with PGE2. Examination of the cause of cell shrinkage showed that induction of a PGE2-stimulated K+ efflux pathway leading to rapid loss of cellular K+ was responsible. The PGE2-stimulated K+ loss was also observed to be Ca2+-dependent, suggesting the possible involvement of the Gardos channel. Gardos channel participation was supported by the observation that two Gardos channel inhibitors, charybdotoxin and clotrimazole, independently blocked the PGE2-stimulated K+ efflux. Further evidence for Gardos channel activation came from experiments aimed at characterizing the efflux pathway followed by the obligatory counterion. Thus, K+ efflux was readily stimulated even when NO3- was substituted for Cl-, suggesting that neither KCl cotransport nor Na/K/2Cl cotransport plays a prominent role in the PGE2-induced cell shrinkage. Further, the anion transporter band 3 was implicated as the counterion efflux route, since DIDS inhibited the PGE2-stimulated cell volume change without blocking the change in membrane potential. Taken together, we propose that release of PGE2 by activated platelets constitutes part of a mechanism by which activated platelets may recruit adjacent erythrocytes to assist in clot formation.

Gamma-Ray Activity in the Crab Nebula: The Exceptional Flare of April 2011

NASA Technical Reports Server (NTRS)

Buehler, R.; Scargle, J. D.; Blandford, R. D.; Baldini, L; Baring, M. G.; Belfiore, A.; Charles, E.; Chiang, J.; DAmmando, F.; Dermer, C. D.;

Development of novobiocin analogues that manifest anti-proliferative activity against several cancer cell lines.

PubMed

Burlison, Joseph A; Avila, Christopher; Vielhauer, George; Lubbers, Donna J; Holzbeierlein, Jeffrey; Blagg, Brian S J

2008-03-21

Recent studies have shown that the DNA gyrase inhibitor, novobiocin, binds to a previously unrecognized ATP-binding site located at the C-terminus of Hsp90 and induces degradation of Hsp90-dependent client proteins at approximately 700 microM. As a result of these studies, several analogues of the coumarin family of antibiotics have been reported and shown to exhibit increased Hsp90 inhibitory activity; however, the monomeric species lacked the ability to manifest anti-proliferative activity against cancer cell lines at concentrations tested. In an effort to develop more efficacious compounds that produce growth inhibitory activity against cancer cell lines, structure-activity relationships were investigated surrounding the prenylated benzamide side chain of the natural product. Results obtained from these studies have produced the first novobiocin analogues that manifest anti-proliferative activity against several cancer cell lines.

Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

NASA Technical Reports Server (NTRS)

Golanov, E. V.; Reis, D. J.

1996-01-01

We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P < 0.05, chi-square) increased their activity during the earliest potential of the complex, approximately 1.3 s before the rise of rCBF, and during the minutes-long elevation of rCBF elicited by 10 s of stimulation of RVL or FN. The results indicate the presence of a small population of neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

Cytochrome P4501A induction, benzo[a]pyrene metabolism, and nucleotide adduct formation in fish hepatoma cells: Effect of preexposure to 3,3',4,4',5-pentachlorobiphenyl

USGS Publications Warehouse

Smeets, J.M.W.; Voormolen, A.; Tillitt, D.E.; Everaarts, J.M.; Seinen, W.; Vanden Berg, M.D.

1999-01-01

In PLHC-1 hepatoma cells, benzo[a]pyrene (B[a]P) caused a maximum induction of cytochrome P4501A (CYP1A) activity, measured as ethoxyresorufin O-deethylation (EROD), after 4 to 8 h of exposure, depending on the B[a]P concentration. The decline of EROD activity at longer exposure times was probably caused by the rapid metabolism of B[a]P in this system (57% metabolism within 4 h incubation). In subsequent experiments, PLHC-1 cells were preinduced with PCB 126 for 24 h and then received a dose of 10, 100, or 1,000 nM 3H-B[a]P. A 1-nM concentration of PCB 126 caused an 80-fold induction of CYP1A activity, resulting in an increase in B[a]P metabolism of less than 10%, except at the highest concentration of B[a]P (1,000 nM), where a 50% increase was observed. In another experiment, an 80-fold induction of CYP1A activity caused a 20% increase in the metabolism of B[a]P (100 nM), and RNA adduct formation was increased approximately twofold. These results indicate that, at exposure concentrations up to 100 nM B[a]P, CYP1A activity is not rate limiting for B[a]P metabolism. Furthermore, CYP1A seems to also he specifically involved in B[a]P activation in PLHC-1 cells. However, CYP1A induction causes only a relatively small increase in activation, probably because of the action of other enzymes involved in B[a]P activation and deactivation.

Affordable Development and Demonstration of a Small NTR Engine and Stage: How Small is Big Enough?

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg (Abraham); Joyner, Claude R.

2015-01-01

The Nuclear Thermal Rocket (NTR) derives its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core. It generates high thrust and has a specific impulse potential of approximately 900 seconds - a 100% increase over today's best chemical rockets. The Nuclear Thermal Propulsion (NTP) project, funded by NASA's AES program, includes five key task activities: (1) Recapture, demonstration, and validation of heritage graphite composite (GC) fuel (selected as the "Lead Fuel" option); (2) Engine Conceptual Design; (3) Operating Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable Development Strategy. During FY'14, a preliminary DDT&E plan and schedule for NTP development was outlined by GRC, DOE and industry that involved significant system-level demonstration projects that included GTD tests at the NNSS, followed by a FTD mission. To reduce cost for the GTD tests and FTD mission, small NTR engines, in either the 7.5 or 16.5 klbf thrust class, were considered. Both engine options used GC fuel and a "common" fuel element (FE) design. The small approximately 7.5 klbf "criticality-limited" engine produces approximately 157 megawatts of thermal power (MWt) and its core is configured with parallel rows of hexagonal-shaped FEs and tie tubes (TTs) with a FE to TT ratio of approximately 1:1. The larger approximately 16.5 klbf Small Nuclear Rocket Engine (SNRE), developed by LANL at the end of the Rover program, produces approximately 367 MWt and has a FE to TT ratio of approximately 2:1. Although both engines use a common 35 inch (approximately 89 cm) long FE, the SNRE's larger diameter core contains approximately 300 more FEs needed to produce an additional 210 MWt of power. To reduce the cost of the FTD mission, a simple "1-burn" lunar flyby mission was considered to reduce the LH2 propellant loading, the stage size and complexity. Use of existing and flight proven liquid rocket and stage hardware (e.g., from the RL10B-2 engine and Delta Cryogenic Second Stage) was also maximized to further aid affordability. This paper examines the pros and cons of using these two small engine options, including their potential to support future human exploration missions to the Moon, near Earth asteroids, and Mars, and recommends a preferred size. It also provides a preliminary assessment of the key activities, development options, and schedule required to affordably build, ground test and fly a small NTR engine and stage within a 10-year timeframe.

The Potential (F)utility of a Passive Organ Donor Registration Opportunity: A Conceptual Replication.

PubMed

Siegel, Jason T; Alvaro, Eusebio M; Tan, Cara N; Navarro, Mario A; Garner, Lori R; Jones, Sara Pace

2016-06-01

Approximately 22 people die each day in the United States as a result of the shortage of transplantable organs. This is particularly problematic among Spanish-dominant Hispanics. Increasing the number of registered organ donors can reduce this deficit. The goal of the current set of studies was to conceptually replicate a prior study indicating the lack of utility of a lone, immediate and complete registration opportunity (ICRO). The study, a quasi-experimental design involving a total of 4 waves of data collection, was conducted in 2 different Mexican consulates in the United States. Guided by the IIFF Model (ie, an ICRO, information, focused engagement, and favorable activation), each wave compared a lone ICRO to a condition that likewise included an ICRO but also included the 3 additional intervention components recommended by the model (ie, information, focused engagement, and favorable activation). Visitors to the Mexican consulates in Tucson, Arizona, and Albuquerque, New Mexico, constituted the participant pool. New organ donor registrations represented the dependent variable. When all 4 components of the IIFF Model were present, approximately 4 registrations per day were recorded; the lone ICRO resulted in approximately 1 registration every 15 days. An ICRO, without the other components of the IIFF Model, is of minimal use in regard to garnering organ donor registrations. Future studies should use the IIFF Model to consider how the utility of ICROs can be maximized. © 2016, NATCO.

Influence of the interfacial peptide organization on the catalysis of hydrogen evolution.

PubMed

Doneux, Th; Dorcák, V; Palecek, E

2010-01-19

The hydrogen evolution reaction is catalyzed by peptides and proteins adsorbed on electrode materials with high overpotentials for this reaction, such as mercury. The catalytic response characteristics are known to be very sensitive to the composition and structure of the investigated biomolecule, opening the way to the implementation of a label-free, reagentless electroanalytical method in protein analysis. Herein, it is shown using the model peptide Cys-Ala-Ala-Ala-Ala-Ala that the interfacial organization significantly influences the catalytic behavior. This peptide forms at the electrode two distinct films, depending on the concentration and accumulation time. The low-coverage film, composed of flat-lying molecules (area per molecule of approximately 250-290 A(2)), yields a well-defined catalytic peak at potentials around -1.75 V. The high-coverage film, made of upright-oriented peptides (area per molecule of approximately 43 A(2)), is catalytically more active and the peak is observed at potentials less negative by approximately 0.4 V. The higher activity, evidenced by constant-current chronopotentiometry and cyclic voltammetry, is attributed to an increase in the acid dissociation constant of the amino acid residues as a result of the low permittivity of the interfacial region, as inferred from impedance measurements. An analogy is made to the known differences in acidic-basic behaviors of solvent-exposed and hydrophobic domains of proteins.

Characterization and Quantitation of Vitamin B12 Compounds in Various Chlorella Supplements.

PubMed

Bito, Tomohiro; Bito, Mariko; Asai, Yusuke; Takenaka, Shigeo; Yabuta, Yukinori; Tago, Kazunori; Ohnishi, Masato; Mizoguchi, Toru; Watanabe, Fumio

2016-11-16

Vitamin B 12 was determined and characterized in 19 dried Chlorella health supplements. Vitamin contents of dried Chlorella cells varied from <0.1 μg to approximately 415 μg per 100 g of dry weight. Subsequent liquid chromatography/electrospray ionization-tandem mass spectrometry analyses showed the presence of inactive corrinoid compounds, a cobalt-free corrinoid, and 5-methoxybenzimidazolyl cyanocobamide (factor IIIm) in four and three high vitamin B 12 -containing Chlorella tablets, respectively. In four Chlorella tablet types with high and moderate vitamin B 12 contents, the coenzyme forms of vitamin B 12 5'-deoxyadenosylcobalamin (approximately 32%) and methylcobalamin (approximately 8%) were considerably present, whereas the unnaturally occurring corrinoid cyanocobalamin was present at the lowest concentrations. The species Chlorella sorokiniana (formerly Chlorella pyrenoidosa) is commonly used in dietary supplements and did not show an absolute requirement of vitamin B 12 for growth despite vitamin B 12 uptake from the medium being observed. In further experiments, vitamin B 12 -dependent methylmalonyl-CoA mutase and methionine synthase activities were detected in cell homogenates. In particular, methionine synthase activity was significantly increased following the addition of vitamin B 12 to the medium. These results suggest that vitamin B 12 contents of Chlorella tablets reflect the presence of vitamin B 12 -generating organic ingredients in the medium or the concomitant growth of vitamin B 12 -synthesizing bacteria under open culture conditions.

Behaviour and occurrence of estrogens in municipal sewage treatment plants--II. Aerobic batch experiments with activated sludge.

PubMed

Ternes, T A; Kreckel, P; Mueller, J

1999-01-12

Aerobic batch experiments containing a diluted slurry of activated sludge from a real sewage treatment plant (STP) near Frankfurt/Main were undertaken, in order to investigate the persistence of natural estrogens and contraceptives under aerobic conditions. The batch experiments showed that while in contact with activated sludge the natural estrogen 17 beta-estradiol was oxidized to estrone, which was further eliminated in the batch experiments in an approximate linear time dependence. Further degradation products of estrone were not observed. 16 alpha-hydroxyestrone was rapidly eliminated, again without detection of further degradation products. The contraceptive 17 alpha-ethinylestradiol was principally persistent under the selected aerobic conditions, whereas mestranol was rapidly eliminated and small portions of 17 alpha-ethinylestradiol were formed by demethylation. Additionally, two glucuronides of 17 beta-estradiol (17 beta-estradiol-17-glucuronide and 17 beta-estradiol-3-glucuronide) were cleaved in contact with the diluted activated sludge solution and thus 17 beta-estradiol was released. The glucuronidase activity of the activated sludge was further confirmed by the cleavage of 4-methylumbelliferyl-beta-D-glucuronide (MUF-beta-glucuronide) in a solution of a activated sludge slurry and Milli-Q-water (1:100, v/v). The turnover rate obtained was approximately steady state, with a turnover rate of 0.1 mumol/l for the released MUF. Hence, it is very likely that the glucuronic acid moiety of 17 beta-estradiol glucuronides and other estrogen glucuronides become cleaved in a real municipal STP, so that the concentrations of the free estrogens increase.

Immobilization of alkaline phosphatase on solid surface through self-assembled monolayer and by active-site protection.

PubMed

Gao, En-Feng; Kang, Kyung Lhi; Kim, Jeong Hee

2014-06-01

Retaining biological activity of a protein after immobilization is an important issue and many studies reported to enhance the activity of proteins after immobilization. We recently developed a new immobilization method of enzyme using active-site protection and minimization of the cross-links between enzyme and surface with a DNA polymerase as a model system. In this study, we extended the new method to an enzyme with a small mono-substrate using alkaline phosphatase (AP) as another model system. A condition to apply the new method is that masking agents, in this case its own substrate needs to stay at the active-site of the enzyme to be immobilized in order to protect the active-site during the harsh immobilization process. This could be achieved by removal of essential divalent ion, Zn2+ that is required for full enzyme activity of AP from the masking solution while active-site of AP was protected with p-nitrophenyl phosphate (pNPP). Approximately 40% of the solution-phase activity was acquired with active-site protected immobilized AP. In addition to protection active-site of AP, the number of immobilization links was kinetically controlled. When the mole fraction of the activated carboxyl group of the linker molecule in self-assembled monolayer (SAM) of 12-mercaptododecanoic acid and 6-mercapto-1-ethanol was varied, 10% of 12-mercaptododecanoic acid gave the maximum enzyme activity. Approximately 51% increase in enzyme activity of the active-site protected AP was observed compared to that of the unprotected group. It was shown that the concept of active-site protection and kinetic control of the number of covalent immobilization bonds can be extended to enzymes with small mono-substrates. It opens the possibility of further extension of the new methods of active-site protection and kinetic control of immobilization bond to important enzymes used in research and industrial fields.

Absorbed photosynthetically active radiation of steppe vegetation and sun-view geometry effects on APAR estimates

NASA Technical Reports Server (NTRS)

Walter-Shea, E. A.; Blad, B. L.; Mesarch, M. A.; Hays, C. J.; Deering, D. W.; Eck, T. F.

1992-01-01

Instantaneous fractions of absorbed photosynthetically active radiation (APAR) were measured at the Streletskaya Steppe Reserve in conjunction with canopy bidirectional-reflected radiation measured at solar zenith angles ranging between 37 and 74 deg during the Kursk experiment (KUREX-91). APAR values were higher for KUREX-91 than those for the first ISLSCP field experiment (FIFE-89) and the amount of APAR of a canopy was a function of solar zenith angle, decreasing as solar zenith angle increased at the resrve. Differences in absorption are attributed to leaf area index (LAI) and leaf angle distribution and subsequently transmitted radiation interactions. LAIs were considerably higher at the reserve than those at the FIFE site. Leaf angle distributions of the reserve approach a uniform distribution while distributions at the FIFE site more closely approximate erectophile distributions. Reflected photosynthetically active radiation (PAR) components at KUREX-91 and FIFE-89 were similar in magnitude and in their response to solar zenith angle. Transmitted PAR increased with increasing solar zenith angle at KUREX-91 and decreased with increasing solar zenith angle at FIFE-89. Transmitted PAR at FIFE-89 was considerably larger than those at KUREX-91.

Walking associated with public transit: moving toward increased physical activity in the United States.

PubMed

Freeland, Amy L; Banerjee, Shailendra N; Dannenberg, Andrew L; Wendel, Arthur M

2013-03-01

We assessed changes in transit-associated walking in the United States from 2001 to 2009 and documented their importance to public health. We examined transit walk times using the National Household Travel Survey, a telephone survey administered by the US Department of Transportation to examine travel behavior in the United States. People are more likely to transit walk if they are from lower income households, are non-White, and live in large urban areas with access to rail systems. Transit walkers in large urban areas with a rail system were 72% more likely to transit walk 30 minutes or more per day than were those without a rail system. From 2001 to 2009, the estimated number of transit walkers rose from 7.5 million to 9.6 million (a 28% increase); those whose transit-associated walking time was 30 minutes or more increased from approximately 2.6 million to 3.4 million (a 31% increase). Transit walking contributes to meeting physical activity recommendations. Study results may contribute to transportation-related health impact assessment studies evaluating the impact of proposed transit systems on physical activity, potentially influencing transportation planning decisions.

Enhancement of Cognitive Processing by Multiple Sclerosis Patients Using Liquid Cooling Technology: A Case Study

NASA Technical Reports Server (NTRS)

Montgomery, Leslie D.; Ku, Yu-Tsuan E.; Montgomery, Richard W.; Kliss, Mark (Technical Monitor)

1997-01-01

Recent neuropsychological studies demonstrate that cognitive dysfunction is a common symptom in patients with multiple sclerosis. In many cases the presence of cognitive impairment affects the patient's daily activities to a greater extent than would be found due to their physical disability alone. Cognitive dysfunction can have a significant impact on the quality of life of both the patient and that of their primary caregiver. Two cognitively impaired male MS patients were given a visual discrimination task before and after a one hour cooling period. The subjects were presented a series of either red or blue circles or triangles. One of these combinations, or one fourth of the stimuli, was designated as the "target" presentation. EEG was recorded from 20 scalp electrodes using a Tracor Northern 7500 EEG/ERP system. Oral and ear temperatures were obtained and recorded manually every five minutes during the one hour cooling period. The EEG ERP signatures from each series of stimuli were analyzed in the energy density domain to determine the locus of neural activity at each EEG sampling time. The first subject's ear temperature did not decrease during the cooling period. It was actually elevated approximately 0.05 C by the end of the cooling period compared to his mean of control period value. In turn, Subject One's discrimination performance and cortical energy remained essentially the same after body cooling. In contrast, Subject Two's ear temperature decreased approx. 0.8 C during his cooling period. Subject Two's ERROR score decreased from 12 during the precooling control period to 2 after cooling. His ENERGY value increased approximately 300%, from a precooling value of approximately 200 to a postcooling value of nearly 600. These findings might be interpreted by the following three-part hypothesis: (1) the general cognitive impairment of MS patients may be a result of low or unfocused metabolic energy conversion in the cortex; (2) such differences show up most strongly in reduced energy in the occipital region during the initial processing of the precooling period visual stimulus which may indicate impaired early visual processing; and (3) increased postcooling activation in the le ft angular gyrus may result in enhanced higher-level reasoning related to processing visual task information. By this hypothesis the superior performance of Subject Two following body cooling may be a result of increased neural activation in his early visual recognition and processing centers.

Evaluating acetaldehyde synthesis from L-/sup 14/C(U)) threonine by Streptococcus thermophilus and Lactobacillus bulgaricus

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

Wilkins, D.W.; Schmidt, R.H.; Shireman, R.B.

To evaluate the synthesis of acetaldehyde from threonine during growth of yogurt cultures, Streptococcus thermophilus MS1 and Lactobacillus bulgaricus MR1 were grown in defined medium in which 10% of the total threonine was composed of L-(carbon-14(U))threonine. Acetaldehyde production was monitored by formation of 2,4-dinitrophenylhydrazone followed by separation and analysis using high performance liquid chromatography. After growth for 8 h at 42/sup 0/C, approximately 2.0% of the total acetaldehyde (780.4 nmol) produced was from L-(carbon-14)threonine. Threonine aldolase activity was determined in cell-free extracts from S. thermophilus and L. bulgaricus grown in Elliker broth. Increasing incubation temperature from 30 to 42/sup 0/Cmore » decreased threonine aldolase activity in cells of the streptococcus harvested after 8 h of incubation. Effect of incubation temperature was more dramatic in cells harvested after 18 h where the activity of cells grown at 48/sup 0/C was 89% lower than that of cells grown at 30/sup 0/C. Cell extracts from S. thermophilus MS1 possessed higher threonine aldolase activity than did those from L. bulgaricus MR1. Increased assay temperature from 30 to 42/sup 0/C increased threonine aldolase activity in S. thermophilus MS1.« less

10-year trends in physical activity in the eastern Finnish adult population: relationship to socioeconomic and lifestyle characteristics.

PubMed

Marti, B; Salonen, J T; Tuomilehto, J; Puska, P

1988-01-01

In a large, community-based cardiovascular disease prevention study in Eastern Finland, independent random population samples were surveyed in 1972, 1977 and 1982. The leisure-time physical activity (LTPA), occupational physical activity (OPA), and socioeconomic and lifestyle characteristics were assessed. In men and women aged 30-59, the proportion with high LTPA increased from 1972 to 1982 by approximately one half (p less than 0.001), whereas that of high OPA decreased during the same period (p less than 0.001). In both sexes, high overall physical activity fell from 1972 to 1977 (p less than 0.001), but no more from 1977 to 1982. The proportion of entirely sedentary remained stable. Education, income and younger age showed a positive, body mass index, smoking and OPA a graded, negative association with high LTPA in 1972 and 1982. Significant (p less than 0.001) differences in 10-year trends of changes in LTPA were observed: men and women with low education or income increased LTPA more than those with high education and income. Socioeconomic factors, such as income and education, appear to have lost importance as determinants of population-wide exercise, whereas the clustering of low physical activity with overweight and smoking has increased.

Physical activity patterns and risk of depression in young adulthood: a 20-year cohort study since childhood.

PubMed

McKercher, Charlotte; Sanderson, Kristy; Schmidt, Michael D; Otahal, Petr; Patton, George C; Dwyer, Terence; Venn, Alison J

2014-11-01

Little is known about how physical activity patterns during childhood and adolescence are associated with risk of subsequent depression. We examined prospective and retrospective associations between leisure physical activity patterns from childhood to adulthood and risk of clinical depression in young adulthood. Participants (759 males, 871 females) in a national survey, aged 9-15 years, were re-interviewed approximately 20 years later. Leisure physical activity was self-reported at baseline (1985) and follow-up (2004-2006). To bridge the interval between the two time-points, historical leisure activity from age 15 years to adulthood was self-reported retrospectively at follow-up. Physical activity was categorized into groups that, from a public health perspective, compared patterns that were least beneficial (persistently inactive) with those increasingly beneficial (decreasing, increasing and persistently active). Depression (major depressive or dysthymic disorder) was assessed using the Composite International Diagnostic Interview. Compared with those persistently inactive, males who were increasingly and persistently active had a 69 and 65 % reduced risk of depression in adulthood, respectively (all p < 0.05). In retrospective analyses, females who were persistently active had a 51 % reduced risk of depression in adulthood (p = 0.01). Similar but non-significant trends were observed for leisure physical activity in females and historical leisure activity in males. Results excluded those with childhood onset of depression and were adjusted for various sociodemographic and health covariates. Findings from both prospective and retrospective analyses indicate a beneficial effect of habitual discretionary physical activity since childhood on risk of depression in young adulthood.

Multiple defects in muscle glycogen synthase activity contribute to reduced glycogen synthesis in non-insulin dependent diabetes mellitus.

PubMed Central

Thorburn, A W; Gumbiner, B; Bulacan, F; Brechtel, G; Henry, R R

1991-01-01

To define the mechanisms of impaired muscle glycogen synthase and reduced glycogen formation in non-insulin dependent diabetes mellitus (NIDDM), glycogen synthase activity was kinetically analyzed during the basal state and three glucose clamp studies (insulin approximately equal to 300, 700, and 33,400 pmol/liter) in eight matched nonobese NIDDM and eight control subjects. Muscle glycogen content was measured in the basal state and following clamps at insulin levels of 33,400 pmol/liter. NIDDM subjects had glucose uptake matched to controls in each clamp by raising serum glucose to 15-20 mmol/liter. The insulin concentration required to half-maximally activate glycogen synthase (ED50) was approximately fourfold greater for NIDDM than control subjects (1,004 +/- 264 vs. 257 +/- 110 pmol/liter, P less than 0.02) but the maximal insulin effect was similar. Total glycogen synthase activity was reduced approximately 38% and glycogen content was approximately 30% lower in NIDDM. A positive correlation was present between glycogen content and glycogen synthase activity (r = 0.51, P less than 0.01). In summary, defects in muscle glycogen synthase activity and reduced glycogen content are present in NIDDM. NIDDM subjects also have less total glycogen synthase activity consistent with reduced functional mass of the enzyme. These findings and the correlation between glycogen synthase activity and glycogen content support the theory that multiple defects in glycogen synthase activity combine to cause reduced glycogen formation in NIDDM. PMID:1899428

Induction of CYP3A4 by efavirenz in primary human hepatocytes: comparison with rifampin and phenobarbital.

PubMed

Hariparsad, Niresh; Nallani, Srikanth C; Sane, Rucha S; Buckley, Donna J; Buckley, Arthur R; Desai, Pankaj B

2004-11-01

The antiretroviral agent efavirenz enhances the systemic clearance of coadministered drugs that are cytochrome P450 (CYP) 3A4 substrates. The mechanism of the apparent increase in CYP3A4 activity by efavirenz and the magnitude of change relative to other known inducers are not known. The authors tested the hypothesis that increased enzymatic activity by efavirenz entails CYP3A4 induction and activation of the human pregnane X receptor (hPXR), a key transcriptional regulator of CYP3A4. Employing primary cultures of human hepatocytes, they compared the CYP3A4 inductive effects of efavirenz (1-10 microM) to rifampin (10 microM) and phenobarbital (2 mM). A cell-based reporter assay was employed to assess hPXR activation. The authors observed that efavirenz caused a concentration-dependent CYP3A4 induction and hPXR activation. Based on the CYP3A4 activity assay, the average magnitude of induction by efavirenz (5-10 microM) was approximately 3- to 4-fold. In comparison, phenobarbital (2 mM) and rifampin (10 microM) caused a 5- and 6-fold induction, respectively.

In vitro selection of high temperature Zn(2+)-dependent DNAzymes.

PubMed

Nelson, Kevin E; Bruesehoff, Peter J; Lu, Yi

2005-08-01

In vitro selection of Zn(2+)-dependent RNA-cleaving DNAzymes with activity at 90 degrees C has yielded a diverse spool of selected sequences. The RNA cleavage efficiency was found in all cases to be specific for Zn(2+) over Pb(2+), Ca(2+), Cd(2+), Co(2+), Hg(2+), and Mg(2+). The Zn(2+)-dependent activity assay of the most active sequence showed that the DNAzyme possesses an apparent Zn(2+)-binding dissociation constant of 234 muM and that its activity increases with increasing temperatures from 50-90 degrees C. A fit of the Arrhenius plot data gave E(a) = 15.3 kcal mol(-1). Surprisingly, the selected Zn(2+)-dependent DNAzymes showed only a modest (approximately 3-fold) activity enhancement over the background rate of cleavage of random sequences containing a single embedded ribonucleotide within an otherwise DNA oligonucleotide. The result is attributable to the ability of DNA to sustain cleavage activity at high temperature with minimal secondary structure when Zn(2+) is present. Since this effect is highly specific for Zn(2+), this metal ion may play a special role in molecular evolution of nucleic acids at high temperature.

Interaction of hydrated electron with dietary flavonoids and phenolic acids: rate constants and transient spectra studied by pulse radiolysis.

PubMed

Cai, Z; Li, X; Katsumura, Y

1999-10-01

The reaction rate constants and transient spectra of 11 flavonoids and 4 phenolic acids reacting with e(aq)- at neutral pH were measured. Absorption bands of the transients of e(aq)- reacting with the above compounds all located at a wavelength shorter than 400 nm. The e(aq)- scavenging abilities were divided into three groups: (+)catechin ((1.2 +/-0.1) x 10(8) M(-1)s(-1)) < 4-chromanol ((4.4 +/- 0.4) x 10(8) M(-1)s(-1)) < genistein ((6.2+/-0.4) x 10(9) M (-1) s(-1) approximately genistin ((8 +/- 1) x 10(9) M(-1)s(-1)) approximately rutin ((7.6 +/- 0.4) x M(-1)s(-1) approximately caffeic acid ((8.3 +/- 0.5) x 10(9)M(-1)s(-1)) < transcinnamic acid((1.1 +/- 0.1) x 10(10) M(-1)s(-1)) approximately p-coumaric acid ((1.1 +/- 0.1) x 10(10) M(-1)s(-1) approximately 2,4,6-trihydroxylbenzoic acid((1.1 +/- 0.1) x 10(10) M(-1)s(-1)) approximately baicalein ((1.1 +/- 0.5) x 10(10) M(-1)s(-1)) approximately baicalin((1.3 + 0.1) X 10(10) M(-1)s(-1)) approximately naringenin ((1.2 +/- 0.1) x 10(10) M(-1)s(-1)) approximately naringin ((1.0 +/- 0.1) x 10(10) M(-1)s(-1)) approximately gossypin((1.2 +/- 0.1) x 10(10) M(-1)s(-1)) approximately quercetin((1.3 +/- 0.5) x 10(10) M(-1)s(-1)). These results suggested that C4 keto group is the active site for e(aq)- to attack on flavonoids and phenolic acids, whereas the o-dihydroxy structure in B ring, the C2,3 double bond, the C3-OH group, and glucosylation, which are key structures that influence the antioxidant activities of flavonoids and phenolic acids, have little effects on the e(aq)- scavenging activities.

[Simple and easy method for measurement of ambulatory activity in mice (author's transl)].

PubMed

Hirabayashi, M; Iizuka, M; Tadokoro, S

1978-07-01

A hand-made apparatus which is easily manipulative, cheap, durable and clean was used to measure ambulatory activity of a mouse. The apparatus was assembled with the same type of two plastic round basins commercially available (25 cm in diameter) put one upon another. A pivot was fixed at the center of the outsurface of the inner basin (A), and its open end was inserted into the open socket fixed at the center on the bottom of the outer basin (B). Three microswitches equipped on the brim of (B) at equal intervals were activated and the counts were recorded according to the tiltings of (A) through the movements of the mouse. In order to examine accuracy of the measurement, effects of d-amphetamine (1.25 approximately 5.0 mg/kg), methamphetamine (1.0 approximately 4.0 mg/kg), cocaine (10 approximately 40 mg/kg) and morphine (5.0 approximately 20.0 mg/kg) on the ambulatory activity were investigated. Marked accelerating effects were observed dose dependently after the administrations of all the drugs. Furthermore, the patterns of the activity showed characteristic properties of each drug. This method is especially useful to measure the acute effect of drugs on the ambulatory activity in mice, and many units can be set up at the same time.

A theory of cerebellar cortex and adaptive motor control based on two types of universal function approximation capability.

PubMed

Fujita, Masahiko

2016-03-01

Lesions of the cerebellum result in large errors in movements. The cerebellum adaptively controls the strength and timing of motor command signals depending on the internal and external environments of movements. The present theory describes how the cerebellar cortex can control signals for accurate and timed movements. A model network of the cerebellar Golgi and granule cells is shown to be equivalent to a multiple-input (from mossy fibers) hierarchical neural network with a single hidden layer of threshold units (granule cells) that receive a common recurrent inhibition (from a Golgi cell). The weighted sum of the hidden unit signals (Purkinje cell output) is theoretically analyzed regarding the capability of the network to perform two types of universal function approximation. The hidden units begin firing as the excitatory inputs exceed the recurrent inhibition. This simple threshold feature leads to the first approximation theory, and the network final output can be any continuous function of the multiple inputs. When the input is constant, this output becomes stationary. However, when the recurrent unit activity is triggered to decrease or the recurrent inhibition is triggered to increase through a certain mechanism (metabotropic modulation or extrasynaptic spillover), the network can generate any continuous signals for a prolonged period of change in the activity of recurrent signals, as the second approximation theory shows. By incorporating the cerebellar capability of two such types of approximations to a motor system, in which learning proceeds through repeated movement trials with accompanying corrections, accurate and timed responses for reaching the target can be adaptively acquired. Simple models of motor control can solve the motor error vs. sensory error problem, as well as the structural aspects of credit (or error) assignment problem. Two physiological experiments are proposed for examining the delay and trace conditioning of eyelid responses, as well as saccade adaptation, to investigate this novel idea of cerebellar processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Childhood obesity: Current and novel approaches.

PubMed

Sabin, Matthew A; Kiess, Wieland

2015-06-01

The prevalence of childhood obesity has increased over the last fifty years by approximately 5% per decade, and approximately a quarter of all children are now either overweight or obese. These children have a significantly increased risk of many future health problems including adult obesity, type 2 diabetes and heart disease. Despite this relentless increase, common-sense approaches aimed at prevention and treatment have failed to solve the problem. Current approaches at prevention have faced major challenges with some progress in implementing smaller scale programs and social marketing, but little action on broad public policy approaches which often appears unpalatable to society or individual governments. Meanwhile, treatment approaches have mainly focused on lifestyle change, and novel approaches are urgently needed. Prevention needs to shift to improving maternal health prior to conception, with more research focussed on the impact of early years in programming offspring to future overweight/obesity. Likewise, treatment paradigms need to move from simply thinking that obesity can be solved by readdressing diet and activity levels. Novel approaches are needed which take into consideration the complex physiology which regulates early childhood growth and the development of obesity in susceptible individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

In-Gel Determination of L-Amino Acid Oxidase Activity Based on the Visualization of Prussian Blue-Forming Reaction

PubMed Central

Zhou, Ning; Zhao, Chuntian

2013-01-01

L-amino acid oxidase (LAAO) is attracting increasing attention due to its important functions. Diverse detection methods with their own properties have been developed for characterization of LAAO. In the present study, a simple, rapid, sensitive, cost-effective and reproducible method for quantitative in-gel determination of LAAO activity based on the visualization of Prussian blue-forming reaction is described. Coupled with SDS-PAGE, this Prussian blue agar assay can be directly used to determine the numbers and approximate molecular weights of LAAO in one step, allowing straightforward application for purification and sequence identification of LAAO from diverse samples. PMID:23383337

Emergency measles control activities--Darfur, Sudan, 2004.

PubMed

2004-10-01

The Darfur region of Sudan, composed of three states with a population of approximately six million, has experienced civil conflict during the previous year, resulting in the internal displacement of approximately one million residents and an exodus of an estimated 170,000 persons to neighboring Chad. The conflict has left a vulnerable population with limited access to food, health care, and other basic necessities. In addition, measles vaccination coverage has been adversely affected; in 2003, coverage was reported to be 46%, 57%, and 77% in North, West, and South Darfur, respectively. This report describes measles-control activities in Darfur region conducted by the Federal Ministry of Health (FMOH) in Sudan in collaboration with the United Nations and nongovernmental organizations (NGOs) during March-August 2004. Ongoing measles transmission in camps for internally displaced persons (IDPs) and neighboring communities in Darfur led to a regionwide measles vaccination campaign targeting all children aged 9 months-15 years, resulting in a reduction in reported measles cases. Once security is improved, ongoing efforts to increase measles vaccine coverage will be required to eliminate persistent susceptibility to measles in the Darfur population.

A New Polar Magnetic Index of Geomagnetic Activity and its Application to Monitoring Ionospheric Parameters

NASA Technical Reports Server (NTRS)

Lyatsky, Wladislaw; Khazanov, George V.

2008-01-01

For improving the reliability of Space Weather prediction, we developed a new, Polar Magnetic (PM) index of geomagnetic activity, which shows high correlation with both upstream solar wind data and related events in the magnetosphere and ionosphere. Similarly to the existing polar cap PC index, the new, PM index was computed from data from two near-pole geomagnetic observatories; however, the method for computing the PM index is different. The high correlation of the PM index with both solar wind data and events in Geospace environment makes possible to improve significantly forecasting geomagnetic disturbances and such important parameters as the cross-polar-cap voltage and global Joule heating in high latitude ionosphere, which play an important role in the development of geomagnetic, ionospheric and thermospheric disturbances. We tested the PM index for 10-year period (1995-2004). The correlation between PM index and upstream solar wind data for these years is very high (the average correlation coefficient R approximately equal to 0.86). The PM index also shows the high correlation with the cross-polar-cap voltage and hemispheric Joule heating (the correlation coefficient between the actual and predicted values of these parameters is approximately 0.9), which results in significant increasing the prediction reliability of these parameters. Using the PM index of geomagnetic activity provides a significant increase in the forecasting reliability of geomagnetic disturbances and related events in Geospace environment. The PM index may be also used as an important input parameter in modeling ionospheric, magnetospheric, and thermospheric processes.

The behavioral response of prey fish to predators: the role of predator size.

PubMed

Tang, Zhong-Hua; Huang, Qing; Wu, Hui; Kuang, Lu; Fu, Shi-Jian

2017-01-01

Predation is one of the key factors governing patterns in natural systems, and adjustments of prey behaviors in response to a predator stimulus can have important ecological implications for wild fish. To investigate the effects of predators on the behavior of prey fish and to test whether the possible effects varied with predator size, black carp (Mylopharyngodon piceus) and snakehead (Channa argus) (a size-matched predator treatment with a similar body size to prey fish and a larger predator treatment with approximately 2.7 times of the body mass of prey fish) were selected to function as prey and predator, respectively. Their spontaneous activities were videorecorded in a central circular arena surrounded by a ring holding the stimulus fish. The distance between prey and predator fish was approximately 200% of the distance between two prey fish, which suggested that black carp can distinguish their conspecifics from heterospecifics and probably recognize the snakehead as a potential predator. The prey fish spent substantially less time moving and exhibited an overall shorter total distance of movement after the size-matched or large predator was introduced, which possibly occurred due to increased vigilance or efforts to reduce the possibility of detection by potential predators. However, there was no significant difference in either distance or spontaneous activities between two predator treatments. These findings suggested that (1) an anti-predator strategy in black carp might involve maintaining a safe distance, decreasing activity and possibly increased vigilance and that (2) the behaviors of prey response to predators were not influenced by their relative size difference.

Solar Coronal Heating and the Magnetic Flux Content of the Network

NASA Technical Reports Server (NTRS)

Moore, R. L.; Falconer, D. A.; Porter, J. G.; Hathaway, D. H.

2003-01-01

We investigate the heating of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic flux in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe IX/X-Fe XII pairs of coronal images from SOHO/EIT. The network magnetic flux content is measured from SOHO/MDI magnetograms. We find that the luminosity of the corona in our quiet regions increases roughly in proportion to the square root of the magnetic flux content of the network and roughly in proportion to the length of the perimeter of the network magnetic flux clumps. From (1) this result, (2) other observations of many fine-scale explosive events at the edges of network flux clumps, and (3) a demonstration that it is energetically feasible for the heating of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of network flux clumps, we infer that in quiet regions that are not influenced by active regions the corona is mainly heated by such magnetic activity in the edges of the network flux clumps. Our observational results together with our feasibility analysis allow us to predict that (1) at the edges of the network flux clumps there are many transient sheared-core bipoles of the size and lifetime of granules and having transverse field strengths greater than approximately - 100 G, (2) approximately 30 of these bipoles are present per supergranule, and (3) most spicules are produced by explosions of these bipoles.

In General, the Total Voltammetric Current from a Mixture of Redox-Active Substances will Not be the Sum of the Currents that Each Substance would Produce Independently at the Same Concentration as in the Mixture

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Oh, Woon Su; Gao, Xue-Rong; Rawashdeh, Abdel Monem M.

2003-01-01

At the potential range where both decamethylferrocene (dMeFc) and ferrocene (Fc) are oxidized with rates controlled by linear diffusion, electrogenerated Fc(+) radicals diffusing outwards from the electrode react quantitatively (K23 C=5.8 x 10(exp 8) with dMeFc diffusing towards the electrode and produce Fc and dMeFc. That reaction replaces dMeFc with Fc, whose diffusion coefficient is higher than that of dMeFc(+), and the total mass-transfer limited current from the mixture is increased by approximately 10%. Analogous observations are made when mass-transfer is controlled by convective-diffusion as in RDE voltammetry. Similar results have been obtained with another, and for all practical purposes randomly selected pair of redox-active substances, [Co(bipy)3](2+) and N - methylphenothiazine (MePTZ); reaction of MePTZ(+) with [Co(bipy)3](2+) replaces the latter with MePTZ, which diffuses faster and the current increases by approximately 20%. The experimental voltammograms have been simulated numerically and the role of (a) the rate constant of the homogeneous reaction; (b) the relative concentrations; and, (c) the diffusion coefficients of all species involved have been studied in detail. Importantly, it was also identified that within any given redox system the dependence of the mass-transfer limited current on the bulk concentrations of the redox-active species is expected to be non-linear. These findings are discussed in terms of their electroanalytical implications.

Hypogravity-induced atrophy of rat soleus and extensor digitorum longus muscles

NASA Technical Reports Server (NTRS)

Riley, D. A.; Ellis, S.; Slocum, G. R.; Satyanarayana, T.; Bain, J. L.; Sedlak, F. R.

1987-01-01

Prolonged exposure of humans to hypogravity causes weakening of their skeletal muscles. This problem was studied in rats exposed to hypogravity for 7 days aboard Spacelab 3. Hindlimb muscles were harvested 12-16 hours postflight for histochemical, biochemical, and ultrastructural analyses. The majority of the soleus and extensor digitorum longus fibers exhibited simple cell shrinkage. However, approximately 1% of the fibers in flight soleus muscles appeared necrotic. Flight muscle fibers showed increased glycogen, lower subsarcolemmal staining for mitochondrial enzymes, and fewer subsarcolemmal mitochondria. During atrophy, myofibrils were eroded by multiple focal losses of myofilaments; lysosomal autophagy was not evident. Tripeptidylaminopeptidase and calcium-activated protease activities of flight soleus fibers were significantly increased, implying a role in myofibril breakdown. Simple fiber atrophy appears to account for muscle weakening during spaceflight, but fiber necrosis is also a contributing factor.

A good walk spoiled: on the disappearance of golf as an active sport in America.

PubMed

Puterbaugh, James S

2011-07-01

During the past 60 years, there has been a major transition in the way golf is played in America. Its potential as exercise largely has been negated by the increase in motorized golf cart usage to approximately two of every three rounds played in this country. Accidents in golf carts have increased rapidly, which, by making the sport more dangerous, will likely bring future regulations. Consequently, playing golf has gradually become more of a public health threat than a benefit. The motorized cart also has resulted in an almost doubling of the size of golf courses, which now occupy a large amount of the built environment designated for activity. These changes are a major loss to society, portend future problems, and call for the sport to reevaluate its current model.

Climate Change in New York State Updating the 2011 ClimAID Climate Risk Information Supplement to NYSERDA Report 11-18 (Responding to Climate Change in New York State)

NASA Technical Reports Server (NTRS)

Horton, Radley M.; Bader, Daniel A.; Rosenzweig, Cynthia; DeGaetano, Arthur T.; Solecki, William

2014-01-01

In its 2013-2014 Fifth Assessment Report (AR5), the Intergovernmental Panel on Climate Change (IPCC) states that there is a greater than 95 percent chance that rising global average temperatures, observed since the mid-20th century, are primarily due to human activities. As had been predicted in the 1800s, the principal driver of climate change over the past century has been increasing levels of atmospheric greenhouse gases associated with fossil-fuel combustion, changing land-use practices, and other human activities. Atmospheric concentrations of the greenhouse gas carbon dioxide are now approximately 40 percent higher than in preindustrial times. Concentrations of other important greenhouse gases, including methane and nitrous oxide, have increased rapidly as well.

Experimental Study on the Velocity and Efficiency Characteristics of a Serial Staged Needle Array-Mesh Type EHD Gas Pump

NASA Astrophysics Data System (ADS)

Qiu, Wei; Xia, Lingzhi; Yang, Lanjun; Zhang, Qiaogen; Xiao, Lei; Chen, Li

2011-12-01

The ionic wind has good application prospects in the fields of air flow control and heat transfer enhancement. The key for successful applications is how to improve the velocity and how to increase the active area of the ionic wind. This paper designed a needle array-mesh type electrohydrodynamic (EHD) gas pump. The use of needle array electrode where corona discharge started simultaneously could enlarge the active area. The velocity of the ionic wind could increase by placing several single-stage ionic wind generators in series appropriately, called as serial staged generator. The maximum average flow velocity of 16.1 m/s and volumetric flow of 303.5 L/min were achieved at the outlet of a 25-stage gas pump and the conversion efficiency was approximately 2.2%.

Oxygen-sensitive regulatory volume increase and Na transport in red blood cells from the cane toad, Bufo marinus.

PubMed

Kristensen, Karina; Koldkjaer, Pia; Berenbrink, Michael; Wang, Tobias

2007-07-01

The red blood cells (RBCs) of cane toad, Bufo marinus, are only partially saturated with oxygen in most of the circulation due to cardiac shunts that cause desaturation of arterial blood. The present study examines the oxygen dependency of RBC ouabain-insensitive unidirectional Na transport, using 22Na, in control cells and in cells exposed to hyperosmotic shrinkage or the beta-adrenergic agonist isoproterenol. Deoxygenation per se induced a slow, but significant Na influx, which was paralleled by a slow increase in RBC volume. Hyperosmotic shrinkage by a calculated 25% activated a robust Na influx that in the first 30 min had a strong PO2 dependency with maximal activation at low PO2 values and a P50 of approximately 5.5 kPa. This activation was completely abolished by the Na/H exchanger (NHE) inhibitor EIPA (10(-4) mol l(-1)). Hyperosmotic shrinkage is particularly interesting in B. marinus as it withstands considerable elevation in extracellular osmolarity following dehydration. Parallel studies showed that deoxygenated B. marinus RBCs had a much faster regulatory volume increase (RVI) response than air-equilibrated RBCs, reflecting the difference in magnitude of Na influxes at the two PO2 values. The extent of RVI ( approximately 60%) after 90 min, however, was similar under the two conditions, reflecting a more prolonged elevation of the shrinkage-induced Na influx in air-equilibrated RBCs. There were no significant differences in the ability to perform RVI between whole blood cells at a PCO2 of 1 and 3 kPa or washed RBCs, and 10(-4) mol l(-1) amiloride reduced the RVI under all conditions, whereas 10(-5) mol l(-1) bumetanide had no effect. Isoproterenol (10(-5) mol l(-1)) induced a significant and prolonged increase in an EIPA-sensitive and bumetanide-insensitive Na influx at low PO2 under iso-osmotic conditions, whilst there was no stimulation by isoproterenol for up to 45 min in air-equilibrated RBCs. The prolonged beta-adrenergic activation of the Na influx at low PO2 is distinctly different from the rapid and transient stimulation in teleost RBCs, suggesting significant differences in the signal transduction pathways leading to transporter activation between vertebrate groups.

Purinergic modulation of adult guinea pig cardiomyocytes in long term cultures and co-cultures with extracardiac or intrinsic cardiac neurones.

PubMed

Horackova, M; Huang, M H; Armour, J A

1994-05-01

To determine the capacity of ATP to modify cardiomyocytes directly or indirectly via peripheral autonomic neurones, the effects of various purinergic agents were studied on long term cultures of adult guinea pig ventricular myocytes and their co-cultures with extracardiac (stellate ganglion) or intrinsic cardiac neurones. Ventricular myocytes and cardiac neurones were enzymatically dissociated and plated together or alone (myocytes only). Myocyte cultures were used for experiments after three to six weeks. The electrical and contractile properties of cultured myocytes and myocyte-neuronal networks were investigated. The spontaneous beating frequency of ventricular myocytes co-cultured with stellate ganglion neurones increased by approximately 140% (p < 0.001) following superfusion with 10(-5) M ATP. This effect was not modified significantly by tetrodotoxin or by beta adrenoceptor blockade (10(-5) M timolol), but was eliminated following application of the P2 antagonist suramin (10(-5) M). Basal spontaneous contractile rate was reduced by approximately 86% (p < 0.001) in the presence of suramin, indicating the existence of tonically active purinergic synaptic mechanisms in stellate ganglion neurone-myocyte cocultures. Suramin did not significantly affect non-innervated myocyte cultures. ATP increased myocyte contractile rate in intrinsic cardiac neurone-myocyte co-cultures by approximately 40% (p < 0.01) under control conditions, but when beta adrenergic receptors of tetrodotoxin sensitive neural responses were blocked, ATP induced greater augmentation (> 100%). In contrast, ATP induced much smaller effects in non-innervated myocyte cultures (approximately 26%, p < 0.01). Analogues of AT) showed the following order of potency: ATP > UTP > MSATP > beta gamma ATP > alpha beta ATP. Adenosine (10(-4) M) attenuated the beating frequency of myocytes in both types of co-culture, while not significantly affecting non-innervated myocyte cultures. The experimental model used in this study showed that extrinsic and intrinsic cardiac neurones which possess P2 receptors can greatly enhance cardiac myocyte contractile rate when activated by ATP. Since adenosine reduced contractile rate in both types of co-cultures while not affecting non-innervated myocytes, it is concluded that some of these neurones possess P1 receptors.

Tea enhances insulin activity.

PubMed

Anderson, Richard A; Polansky, Marilyn M

2002-11-20

The most widely known health benefits of tea relate to the polyphenols as the principal active ingredients in protection against oxidative damage and in antibacterial, antiviral, anticarcinogenic, and antimutagenic activities, but polyphenols in tea may also increase insulin activity. The objective of this study was to determine the insulin-enhancing properties of tea and its components. Tea, as normally consumed, was shown to increase insulin activity >15-fold in vitro in an epididymal fat cell assay. Black, green, and oolong teas but not herbal teas, which are not teas in the traditional sense because they do not contain leaves of Camellia senensis, were all shown to increase insulin activity. High-performance liquid chromatography fractionation of tea extracts utilizing a Waters SymmetryPrep C18 column showed that the majority of the insulin-potentiating activity for green and oolong teas was due to epigallocatechin gallate. For black tea, the activity was present in several regions of the chromatogram corresponding to, in addition to epigallocatechin gallate, tannins, theaflavins, and other undefined compounds. Several known compounds found in tea were shown to enhance insulin with the greatest activity due to epigallocatechin gallate followed by epicatechin gallate, tannins, and theaflavins. Caffeine, catechin, and epicatechin displayed insignificant insulin-enhancing activities. Addition of lemon to the tea did not affect the insulin-potentiating activity. Addition of 5 g of 2% milk per cup decreased the insulin-potentiating activity one-third, and addition of 50 g of milk per cup decreased the insulin-potentiating activity approximately 90%. Nondairy creamers and soy milk also decreased the insulin-enhancing activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate.

Effect of daily oscillation in temperature and increased suspended sediment on growth and smolting in juvenile chinook salmon, Oncorhynchus tshawytscha

USGS Publications Warehouse

Shrimpton, J.M.; Zydlewski, Joseph D.; Heath, J.W.

2007-01-01

We examined the effect of temperature oscillation and increased suspended sediment concentration on growth and smolting in juvenile ocean-type chinook salmon (Oncorhynchus tshawytscha). Fish were ponded on February 26; each treatment group had three replicates of 250 fish. Mean temperatures for the entire experiment were 12.3????C for all tanks with a total of 1348 and 1341 degree days for the constant temperature and oscillating temperature tanks, respectively. Daily fluctuation in temperature averaged 7.5????C in the variable temperature groups and less than 1????C for the constant temperature group. Starting on April 5, bentonite clay was added each day to tanks as a pulse event to achieve a suspended sediment concentration of 200??mg l- 1; clay cleared from the tanks within approximately 8??h. Fish were sampled at approximately two??week intervals from ponding until mid-June. On the last sample date, June 12, a single gill arch was removed and fixed for histological examination of gill morphology. By early May, significant differences were seen in size between the groups; control > temperature = sediment > (temperature ?? sediment). This relationship was consistent throughout the experiment except for the last sample date when the temperature group had a mean weight significantly greater than the sediment group. Gill Na+,K+-ATPase activity was not affected by daily temperature oscillations, but groups subjected to increased suspended sediment had significantly lower enzyme activities compared to controls. Mean cell size for gill chloride cells did not differ between groups. Plasma cortisol increased significantly during the spring, but there were no significant differences between groups. ?? 2007 Elsevier B.V. All rights reserved.

Simulation of action potentials from metabolically impaired cardiac myocytes. Role of ATP-sensitive K+ current.

PubMed

Ferrero, J M; Sáiz, J; Ferrero, J M; Thakor, N V

1996-08-01

The role of the ATP-sensitive K+ current (IK-ATP) and its contribution to electrophysiological changes that occur during metabolic impairment in cardiac ventricular myocytes is still being discussed. The aim of this work was to quantitatively study this issue by using computer modeling. A model of IK-ATP is formulated and incorporated into the Luo-Rudy ionic model of the ventricular action potential. Action potentials under different degrees of activation of IK-ATP are simulated. Our results show that in normal ionic concentrations, only approximately 0.6% of the KATP channels, when open, should account for a 50% reduction in action potential duration. However, increased levels of intracellular Mg2+ counteract this shortening. Under conditions of high [K+]0, such as those found in early ischemia, the activation of only approximately 0.4% of the KATP channels could account for a 50% reduction in action potential duration. Thus, our results suggest that opening of IK-ATP channels should play a significant role in action potential shortening during hypoxic/ischemic episodes, with the fraction of open channels involved being very low ( < 1%). However, the results of the model suggest that activation of IK-ATP alone does not quantitatively account for the observed K+ efflux in metabolically impaired cardiac myocytes. Mechanisms other than KATP channel activation should be responsible for a significant part of the K+ efflux measured in hypoxic/ischemic situations.

Substance P receptor desensitization requires receptor activation but not phospholipase C

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

Sugiya, Hiroshi; Putney, J.W. Jr.

1988-08-01

Previous studies have shown that exposure of parotid acinar cells to substance P at 37{degree}C results in activation of phospholipase C, formation of ({sup 3}H)inositol 1,4,5-trisphosphate (IP{sub 3}), and persistent desensitization of the substance P response. In cells treated with antimycin in medium containing glucose, ATP was decreased to {approximately}20% of control values, IP{sub 3} formation was completely inhibited, but desensitization was unaffected. When cells were treated with antimycin in the absence of glucose, cellular ATP was decreased to {approximately}5% of control values, and both IP{sub 3} formation and desensitization were blocked. A series of substance P-related peptides increased themore » formation of ({sup 3}H)IP{sub 3} and induced desensitization of the substance P response with a similar rank order of potencies. The substance P antagonist, (D-Pro{sup 2}, D-Try{sup 7,9})-substance P, inhibited substance P-induced IP{sub 3} formation and desensitization but did not induce desensitization. These results suggest that the desensitization of substance P-induced IP{sub 3} formation requires agonist activation of a P-type substance P receptor, and that one or more cellular ATP-dependent processes are required for this reaction. However, activation of phospholipase C and the generation of inositol phosphates does not seem to be a prerequisite for desensitization.« less

The Limit of Free Magnetic Energy in Active Regions

NASA Technical Reports Server (NTRS)

Moore, Ron; Falconer, David; Sterling, Alphonse

2012-01-01

By measuring from active-region magnetograms a proxy of the free energy in the active region fs magnetic field, it has been found previously that (1) there is an abrupt upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region fs magnetic flux content, and (2) the free energy is usually near its limit when the field explodes in a CME/flare eruption. That is, explosive active regions are concentrated in a main-sequence path bordering the free-energy ]limit line in (flux content, free-energy proxy) phase space. Here, from measurement of Marshall Space Flight Center vector magnetograms, we find the magnetic condition that underlies the free ]energy limit and the accompanying main sequence of explosive active regions. Using a suitable free ]energy proxy measured from vector magnetograms of 44 active regions, we find that (1) in active regions at and near their free ]energy limit, the ratio of magnetic-shear free energy to the non ]free magnetic energy the potential field would have is approximately 1 in the core field, the field rooted along the neutral line, and (2) this ratio is progressively less in active regions progressively farther below their free ]energy limit. This shows that most active regions in which this core-field energy ratio is much less than 1 cannot be triggered to explode; as this ratio approaches 1, most active regions become capable of exploding; and when this ratio is 1 or greater, most active regions are compelled to explode. From these results we surmise the magnetic condition that determines the free ]energy limit is the ratio of the free magnetic energy to the non-free energy the active region fs field would have were it completely relaxed to its potential ]field configuration, and that this ratio is approximately 1 at the free-energy limit and in the main sequence of explosive active regions.

Increased locomotor and thermogenic activity in mice with targeted ablation of the GHRH gene.

PubMed

Leone, Sheila; Chiavaroli, Annalisa; Shohreh, Rugia; Ferrante, Claudio; Ricciuti, Adriana; Manippa, Fabio; Recinella, Lucia; Di Nisio, Chiara; Orlando, Giustino; Salvatori, Roberto; Vacca, Michele; Brunetti, Luigi

2015-04-01

Growth hormone (GH) deficiency (GHD) leads to growth failure and changes in body composition, including increased fat accumulation and reduced lean body mass in both humans and rodents. The aim of this study was to examine the factors that contribute to energy imbalance in the GH releasing hormone knock out (GHRHKO) mice, a well established model of GHD. We evaluated food intake (of standard laboratory chow), total body weight (TBW), locomotor activity, body temperature and interscapular brown adipose tissue (BAT) weight in 8 adult male mice homozygous for the GHRHKO allele (-/-) and 8 heterozygous (+/-) animals as controls. The gene expression of uncoupling protein-1 (UCP-1) in BAT and the levels of norepinephrine (NE), dopamine (DA), and serotonin (5-hydroxytryptamine, 5-HT) in the ventral striatum were measured by real-time reverse transcription polymerase chain reaction (RT-PCR) and high performance liquid chromatography (HPLC) analysis, respectively. Throughout 2 months of observation -/- mice consumed approximately 40% more food (normalized to TBW; P<0.001), and showed increased locomotor activity in 24h time compared to controls (P<0.05). Moreover, -/- animals showed increased body temperature (P<0.001), BAT weight (P<0.001), and UCP-1 gene expression (P<0.001), while NE levels in the striatum area were lower (P<0.05) than controls. The present study demonstrates that the increased food intake observed in GHRH ablated animals is associated with increased locomotor and thermogenic activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stimulation of the p38 Mitogen-activated Protein Kinase Pathway in Neonatal Rat Ventricular Myocytes by the G Protein–coupled Receptor Agonists, Endothelin-1 and Phenylephrine: A Role in Cardiac Myocyte Hypertrophy?

PubMed Central

Clerk, Angela; Michael, Ashour; Sugden, Peter H.

1998-01-01

We examined the activation of the p38 mitogen-activated protein kinase (p38-MAPK) pathway by the G protein–coupled receptor agonists, endothelin-1 and phenylephrine in primary cultures of cardiac myocytes from neonatal rat hearts. Both agonists increased the phosphorylation (activation) of p38-MAPK by ∼12-fold. A p38-MAPK substrate, MAPK-activated protein kinase 2 (MAPKAPK2), was activated approximately fourfold and 10 μM SB203580, a p38-MAPK inhibitor, abolished this activation. Phosphorylation of the MAPKAPK2 substrate, heat shock protein 25/27, was also increased. Using selective inhibitors, activation of the p38-MAPK pathway by endothelin-1 was shown to involve protein kinase C but not Gi/Go nor the extracellularly responsive kinase (ERK) pathway. SB203580 failed to inhibit the morphological changes associated with cardiac myocyte hypertrophy induced by endothelin-1 or phenylephrine between 4 and 24 h. However, it decreased the myofibrillar organization and cell profile at 48 h. In contrast, inhibition of the ERK cascade with PD98059 prevented the increase in myofibrillar organization but not cell profile. These data are not consistent with a role for the p38-MAPK pathway in the immediate induction of the morphological changes of hypertrophy but suggest that it may be necessary over a longer period to maintain the response. PMID:9679149

Increasing Rural Adults' Participation in Collegial Programs: Exemplary Programs. Proceedings of the Rural Action Conference "Programs and Activities to Overcome Barriers to Rural Adult Participation in Postsecondary Education" (Blacksburg, Virginia, June 1-3, 1987).

ERIC Educational Resources Information Center

Sullins, W. Robert, Ed.; And Others

Approximately 85 educators from six states participated in a regional conference designed to showcase exemplary and collaborative programs to overcome many of the barriers faced by rural adults in pursuing higher education. After the keynote address, "The Role of Adult Learning in Revitalizing Rural Communities," by Cornelia Butler Flora, the…

’Don’t Ask, Don’t Tell’: The Law and Military Policy on Same-Sex Behavior

DTIC Science & Technology

2010-10-14

created a legal avenue via which homosexuals could announce their sexuality without being discharged. Shortly afterward, the Department of Defense...increase in statement cases. Discharges for homosexual acts and marriages has declined by 20% over the past three years [1994-1997]. Second, most of those...continuation of homosexual discharges while addressing legal concerns over the wording of the previous policy.39 The active duty force numbered approximately

Preparation and evaluation of β-glucan hydrogel prepared by the radiation technique for drug carrier applications.

PubMed

Park, Jong-Seok; Lim, Youn-Mook; Baik, Jae; Jeong, Jin-Oh; An, Sung-Jun; Jeong, Sung-In; Gwon, Hui-Jeong; Khil, Myung-Seob

2018-06-14

β-Glucan can provide excellent environment to apply to drug carrier due to its immunological and anti-inflammatory effect. Minocycline hydrochloride (MH) has excellent oral bioavailability pharmacological properties. Specifically, MH is effectively absorbed into the gingiva for periodontal disease treatment. In this study, we attempt to develop MH loaded β-glucan hydrogel for periodontal disease treatment through radiation-crosslinking technique. In addition, MH loaded β-glucan hydrogels were tested for their cytotoxicity and antibacterial activity. Finally, we conducted an in vivo study to demonstrate the potential to prevent the invasion of bacteria to treat periodontal disease. The gel content and compressive strength of the β-glucan hydrogels increased as the β-glucan content and the absorbed dose (up to 7 kGy) increased. For a radiation dose of 7 kGy, the gelation and the compressive strength of a 6 wt% β-glucan hydrogel were approximately 92% and 270 kPa, respectively. As a drug, MH was consistently released from β-glucan hydrogels, reaching 80% at approximately 90 min. Furthermore, the MH loaded β-glucan hydrogels showed no cytotoxicity. The MH loaded β-glucan hydrogels exhibited good antibacterial activity against Porphyromonas gingivalis. In addition, MH loaded β-glucan hydrogel demonstrated the potential of a good capability to prevent the invasion of bacteria and to treat wounds. Copyright © 2017. Published by Elsevier B.V.

Exploring the Roles of Extracurricular Activity Quantity and Quality in the Educational Resilience of Vulnerable Adolescents: Variable- and Pattern-Centered Approaches

PubMed Central

Peck, Stephen C.; Roeser, Robert W.; Zarrett, Nicole; Eccles, Jacquelynne S.

2009-01-01

This longitudinal study examines how extracurricular activity involvement contributes to “educational resilience”—the unexpected educational attainments of adolescents who are otherwise vulnerable to curtailed school success due to personal- and social-level risks. Educationally vulnerable youth characterized by significant risks and an absence of assets were identified during early adolescence (approximately age 14) using measures of academic motivation, achievement, and mental health as well as family, school, and peer contexts. Using a mixture of variable- and pattern-centered analytic techniques, we investigate how both the total amount time that vulnerable youth spent in positive extracurricular activities and the specific pattern of their extracurricular activity involvement during late adolescence (approximately age 17) predict their subsequent enrollment in college during early adulthood (up through approximately age 21). Educational resilience was predicted uniquely by some, but not all, activity patterns. These results suggest that positive extracurricular activity settings afford vulnerable youth developmentally appropriate experiences that promote educational persistence and healthy development. PMID:19543445

Exploring the Roles of Extracurricular Activity Quantity and Quality in the Educational Resilience of Vulnerable Adolescents: Variable- and Pattern-Centered Approaches.

PubMed

Peck, Stephen C; Roeser, Robert W; Zarrett, Nicole; Eccles, Jacquelynne S

2008-01-01

This longitudinal study examines how extracurricular activity involvement contributes to "educational resilience"-the unexpected educational attainments of adolescents who are otherwise vulnerable to curtailed school success due to personal- and social-level risks. Educationally vulnerable youth characterized by significant risks and an absence of assets were identified during early adolescence (approximately age 14) using measures of academic motivation, achievement, and mental health as well as family, school, and peer contexts. Using a mixture of variable- and pattern-centered analytic techniques, we investigate how both the total amount time that vulnerable youth spent in positive extracurricular activities and the specific pattern of their extracurricular activity involvement during late adolescence (approximately age 17) predict their subsequent enrollment in college during early adulthood (up through approximately age 21). Educational resilience was predicted uniquely by some, but not all, activity patterns. These results suggest that positive extracurricular activity settings afford vulnerable youth developmentally appropriate experiences that promote educational persistence and healthy development.

Electrolytes for Low Impedance, Wide Operating Temperature Range Lithium-Ion Battery Module

NASA Technical Reports Server (NTRS)

Hallac, Boutros (Inventor); Krause, Frederick C. (Inventor); Jiang, Junwei (Inventor); Smart, Marshall C. (Inventor); Metz, Bernhard M. (Inventor); Bugga, Ratnakumar V. (Inventor)

2018-01-01

A lithium ion battery cell includes a housing, a cathode disposed within the housing, wherein the cathode comprises a cathode active material, an anode disposed within the housing, wherein the anode comprises an anode active material, and an electrolyte disposed within the housing and in contact with the cathode and anode. The electrolyte consists essentially of a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and an additive mixture. The solvent mixture includes a cyclic carbonate, an non-cyclic carbonate, and a linear ester. The additive mixture consists essentially of lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte, and vinylene carbonate (VC) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte.

Functional Activity of Matrix Metalloproteinases 2 and 9 in Tears of Patients With Glaucoma.

PubMed

Sahay, Prity; Rao, Aparna; Padhy, Debananda; Sarangi, Sarada; Das, Gopinath; Reddy, Mamatha M; Modak, Rahul

2017-05-01

To evaluate the differential expression of tear matrix metalloproteinases (MMP) 2 and 9 in of patients with various forms of glaucoma. Tear samples were collected with a Schirmer's strip from 148 eyes of 113 patients (medically naïve patients with primary open-angle [POAG] or angle closure glaucoma [PACG] and those with pseudoexfoliation syndrome [PXF] or glaucoma [PXG]). These were compared to patients undergoing cataract surgery (controls) for this cross-sectional study. Functional activities of tear MMP-9 and MMP-2 were analyzed by gelatin zymography. Tenon's capsules (n = 15) were harvested from the inferior quadrant in those undergoing cataract surgery and protein expression of MMP-9 was analyzed by immunohistochemistry (IHC). Hydrogen peroxide (H2O2) stress-induced effects on in vitro activities of MMP-9 in human trabecular meshwork (HTM) cells were analyzed. The MMP-9 activity in tears was increased significantly in POAG, (n = 27), PACG (n = 24), and PXF (n = 40) eyes compared to controls (n = 35), and was increased significantly in eyes with glaucoma compared to moderate/severe glaucoma (P < 0.001). The MMP-9 expression was significantly lower in PXG (n = 22) eyes. Immunohistochemistry of Tenon's capsule revealed increased expression of MMP-9 in primary glaucoma eyes. Increased MMP-9 activity was seen in in vitro by gelatin zymography and was confirmed by Western and immunofluorescent assay on HTM upon 800 and 1000 μM H2O2-induced stress for 2 to 3 hours with approximately 80% cell death. Increased tear MMP-9 activity in early glaucoma and pseudoexfoliation syndrome suggesting activation of extracellular matrix (ECM) degradation can be used as a tear-based predictive biomarker. Decreased expression in advanced stages suggests exhaustion of the degradation response.

Hsc66 and Hsc20, a new heat shock cognate molecular chaperone system from Escherichia coli.

PubMed

Vickery, L E; Silberg, J J; Ta, D T

1997-05-01

The hscA and hscB genes of Escherichia coli encode novel chaperone and co-chaperone proteins, designated Hsc66 and Hsc20, respectively. We have overproduced and purified Hsc66 and Hsc20 in high yield in E. coli and describe their initial characterization including absorbance, fluorescence, and circular dichroism spectra. Immunoblot analyses of E. coli cultures using antisera to Hsc66 and Hsc20 raised in rabbits establish that Hsc66 and Hsc20 are constitutively expressed at levels corresponding to cell concentration approximately 20 microM and approximately 10 microM, respectively. The levels do not change appreciably following heat shock (44 degrees C), but a small increase in Hsc20 is observed following a shift to 10 degrees C. Purified Hsc66 exhibits a low intrinsic ATPase activity (approximately 0.6 min-1 at 37 degrees C), and Hsc20 was found to stimulate this activity up to 3.8-fold with half-maximal stimulation at a concentration approximately 5 microM. These findings suggest that Hsc66 and Hsc20 comprise a molecular chaperone system similar to the prokaryotic DnaK/DnaJ and eukaryotic hsp70/hsp40 systems. Sequence differences between Hsc66 and Hsc20 compared to other members of this chaperone family, however, suggest that the Hsc66/Hsc20 system will display different peptide binding specificity and that it is likely to be subject to different regulatory mechanisms. The high level of constitutive expression and the lack of a major response to temperature changes suggest that Hsc66 and Hsc20 play an important cellular role(s) under non-stress conditions.

Hsc66 and Hsc20, a new heat shock cognate molecular chaperone system from Escherichia coli.

PubMed Central

Vickery, L. E.; Silberg, J. J.; Ta, D. T.

1997-01-01

The hscA and hscB genes of Escherichia coli encode novel chaperone and co-chaperone proteins, designated Hsc66 and Hsc20, respectively. We have overproduced and purified Hsc66 and Hsc20 in high yield in E. coli and describe their initial characterization including absorbance, fluorescence, and circular dichroism spectra. Immunoblot analyses of E. coli cultures using antisera to Hsc66 and Hsc20 raised in rabbits establish that Hsc66 and Hsc20 are constitutively expressed at levels corresponding to cell concentration approximately 20 microM and approximately 10 microM, respectively. The levels do not change appreciably following heat shock (44 degrees C), but a small increase in Hsc20 is observed following a shift to 10 degrees C. Purified Hsc66 exhibits a low intrinsic ATPase activity (approximately 0.6 min-1 at 37 degrees C), and Hsc20 was found to stimulate this activity up to 3.8-fold with half-maximal stimulation at a concentration approximately 5 microM. These findings suggest that Hsc66 and Hsc20 comprise a molecular chaperone system similar to the prokaryotic DnaK/DnaJ and eukaryotic hsp70/hsp40 systems. Sequence differences between Hsc66 and Hsc20 compared to other members of this chaperone family, however, suggest that the Hsc66/Hsc20 system will display different peptide binding specificity and that it is likely to be subject to different regulatory mechanisms. The high level of constitutive expression and the lack of a major response to temperature changes suggest that Hsc66 and Hsc20 play an important cellular role(s) under non-stress conditions. PMID:9144776

Modulation of nucleotide sensitivity of ATP-sensitive potassium channels by phosphatidylinositol-4-phosphate 5-kinase.

PubMed

Shyng, S L; Barbieri, A; Gumusboga, A; Cukras, C; Pike, L; Davis, J N; Stahl, P D; Nichols, C G

2000-01-18

ATP-sensitive potassium channels (K(ATP) channels) regulate cell excitability in response to metabolic changes. K(ATP) channels are formed as a complex of a sulfonylurea receptor (SURx), a member of the ATP-binding cassette protein family, and an inward rectifier K(+) channel subunit (Kir6.x). Membrane phospholipids, in particular phosphatidylinositol (PI) 4,5-bisphosphate (PIP(2)), activate K(ATP) channels and antagonize ATP inhibition of K(ATP) channels when applied to inside-out membrane patches. To examine the physiological relevance of this regulatory mechanism, we manipulated membrane PIP(2) levels by expressing either the wild-type or an inactive form of PI-4-phosphate 5-kinase (PIP5K) in COSm6 cells and examined the ATP sensitivity of coexpressed K(ATP) channels. Channels from cells expressing the wild-type PIP5K have a 6-fold lower ATP sensitivity (K(1/2), the half maximal inhibitory concentration, approximately 60 microM) than the sensitivities from control cells (K(1/2) approximately 10 microM). An inactive form of the PIP5K had little effect on the K(1/2) of wild-type channels but increased the ATP-sensitivity of a mutant K(ATP) channel that has an intrinsically lower ATP sensitivity (from K(1/2) approximately 450 microM to K(1/2) approximately 100 microM), suggesting a decrease in membrane PIP(2) levels as a consequence of a dominant-negative effect of the inactive PIP5K. These results show that PIP5K activity, which regulates PIP(2) and PI-3,4,5-P(3) levels, is a significant determinant of the physiological nucleotide sensitivity of K(ATP) channels.

Birth weight and time spent in outdoor physical activity during adolescence.

PubMed

Gopinath, Bamini; Hardy, Louise L; Baur, Louise A; Burlutsky, George; Mitchell, Paul

2013-03-01

We investigated the association between birth parameters (weight, length, and head circumference) and time spent in physical activity (outdoor and indoor) and screen time (TV viewing, computer, and videogame usage) among adolescents. A longitudinal cohort study surveyed 1794 children in 2004-2005 (median age = 12.7 yr), and 752 were resurveyed 5 yr later in 2009-2010 (age = 17-18 yr). Adolescents completed detailed activity questionnaires. Parents extracted birth parameter data from their child's health record booklet. After adjusting for age, sex, ethnicity, gestational age, parental education, home ownership, exposure to passive smoking, and body mass index, 12-yr-old children in the highest compared with the lowest quartile of birth weight spent on average approximately 56 and 62 min more in total (Ptrend = 0.02) and outdoor physical activity (Ptrend = 0.02) per week, respectively. Similarly, 12-yr-old children in the high (>4000 g) versus very low (<2000 g) birth weight group spent approximately 1.3 h·wk more in outdoor activity (Ptrend = 0.02). Among those age 17-18 yr, increasing birth weight (lowest to highest quartile) was associated with greater time spent in outdoor physical activity (∼1 h·wk-1, Ptrend = 0.04). Significant associations were not observed between all birth parameters and recreational screen time. Also, no associations were observed between head circumference or birth length with physical activity and screen time. Birth weight could be a potential determinant of physical activity, but not of screen time during adolescence. Hence, this could be part of the underlying mechanism between prenatal influences and future disease risk and could have possible clinical implications.

Temperature influence on the development and loss of seawater tolerance in two fast-growing strains of Atlantic salmon

USGS Publications Warehouse

Handeland, S.O.; Wilkinson, E.; Sveinsbo, B.; McCormick, S.D.; Stefansson, S.O.

2004-01-01

Development of hypo-osmoregulatory ability, gill Na+,K +-ATPase activity, condition factor and growth in Atlantic salmon during parr-smolt transformation was studied in a 2??3 factorial design with three temperatures (12.0, 8.9??C and ambient, 2.4-11.9??C, mean: 6.0??C) and two farmed strains of smolts (Mowi and AquaGen). The development of hypo-osmoregulatory ability and gill Na+,K+-ATPase activity were significantly influenced by freshwater temperature. In smolts raised at 12.0??C, maximum gill Na+,K+-ATPase activity was reached in late April, compared with late May and mid-June in the 8.9??C and ambient groups, respectively. In all groups, peak gill Na+,K +-ATPase activity was seen 350 degree days (d??C) after the onset of the smolt-related increase in enzyme activity (30 March) The period of high enzyme activity (>90% of maximum) lasted approximately 250 d??C. No distinct peak level in gill Na+,K+-ATPase activity was seen in the AquaGen strain at ambient temperature. Elevated temperatures also accelerated the loss of hypo-osmoregulatory capacity. In all groups, gill Na+,K+-ATPase activity reached pre-smolt levels approximately 500 d??C after the calculated peak level. Growth rate in freshwater was influenced by strain, temperature and their interaction, with the Mowi strain showing a higher growth rate than the AquaGen strain at 8.9??C and ambient temperatures. Following transfer to seawater, a higher growth rate was recorded in smolts from the Mowi strain than the AquaGen strain from the ambient temperature regime. Temperature influences the development and loss of smolt characteristics in both strains, and has long-term effects on post-smolt performance in seawater. ?? 2004 Elsevier B.V. All rights reserved.

Stachybotrys chartarum alters surfactant-related phospholipid synthesis and CTP:cholinephosphate cytidylyltransferase activity in isolated fetal rat type II cells.

PubMed

Hastings, C; Rand, T; Bergen, H T; Thliveris, J A; Shaw, A R; Lombaert, G A; Mantsch, H H; Giles, B L; Dakshinamurti, S; Scott, J E

2005-03-01

Stachybotry chartarum, a fungal contaminant of water-damaged buildings commonly grows on damp cellulose-containing materials. It produces a complex array of mycotoxins. Their mechanisms of action on the pulmonary system are not entirely clear. Previous studies suggest spore products may depress formation of disaturated phosphatidylcholine (DSPC), the major surface-active component of pulmonary surfactant (PS). If S. chartarum can indeed affect formation of this phospholipid, then mold exposure may be a significant issue for pulmonary function in both mature lung and developing fetal lung. To address this possibility, fetal rat type II cells, the principal source of DSPC, were used to assess effects of S. chartarum extract on formation of DSPC. Isolated fetal rat lung type II cells prelabeled with 3H-choline and incubated with spore extract showed decreased incorporation of 3H-choline into DSPC. The activity of CTP:cholinephosphate cytidylyltransferase (CPCT), the rate-limiting enzyme in phosphatidylcholine synthesis was reduced by approximately 50% by a 1:10 dilution of spore extract. Two different S. chartarum extracts (isolates from S. chartarum (Cleveland) and S. chartarum (Hawaiian)) were used to compare activity of CPCT in the presence of phosphatidylglycerol (PG), a known activator. PG produced an approximate two-fold increase in CPCT activity. The spore isolate from Hawaii did not alter enzyme activity. S. chartarum (Cleveland) eliminated the PG-induced activation of CPCT. These results support previous observations that mold products alter PS metabolism and may pose a risk in developing lung, inhibiting surfactant synthesis. Different isolates of the same species of fungus are not equivalent in terms of potential exposure risks.

Muscle force output and electromyographic activity in squats with various unstable surfaces.

PubMed

Saeterbakken, Atle H; Fimland, Marius S

2013-01-01

The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.

Physical activity-related injury and body mass index among US high school students.

PubMed

Lowry, Richard; Lee, Sarah M; Galuska, Deborah A; Fulton, Janet E; Barrios, Lisa C; Kann, Laura

2007-07-01

Few studies have focused on the relationship between physical activity-related (PA) injury and overweight among youth. We analyzed data from the 2001 and 2003 Youth Risk Behavior Surveys (n = 28,815). Logistic regression was used to examine the independent effects of BMI and frequency of participation in vigorous activity, moderate activity, strengthening exercises, physical education (PE) classes, and team sports on the likelihood of PA injury. Approximately 14% of females and 19% of males reported seeing a doctor or nurse during the previous 30 d for an injury that happened while exercising or playing sports. PA injury was associated with participation in team sports, strengthening exercises, and (among females) vigorous physical activity. Controlling for type and frequency of physical activity, injury was not associated with being overweight (BMI >or= 95th percentile). Moderate physical activity and school PE classes may provide relatively low-risk alternatives for overweight youth who need to increase their physical activity.

Butyrate and other short-chain fatty acids increase the rate of lipolysis in 3T3-L1 adipocytes

PubMed Central

Rumberger, John M.; Arch, Jonathan R.S.

2014-01-01

We determined the effect of butyrate and other short-chain fatty acids (SCFA) on rates of lipolysis in 3T3-L1 adipocytes. Prolonged treatment with butyrate (5 mM) increased the rate of lipolysis approximately 2–3-fold. Aminobutyric acid and acetate had little or no effect on lipolysis, however propionate stimulated lipolysis, suggesting that butyrate and propionate act through their shared activity as histone deacetylase (HDAC) inhibitors. Consistent with this, the HDAC inhibitor trichostatin A (1 µM) also stimulated lipolysis to a similar extent as did butyrate. Western blot data suggested that neither mitogen-activated protein kinase (MAPK) activation nor perilipin down-regulation are necessary for SCFA-induced lipolysis. Stimulation of lipolysis with butyrate and trichostatin A was glucose-dependent. Changes in AMP-activated protein kinase (AMPK) phosphorylation mediated by glucose were independent of changes in rates of lipolysis. The glycolytic inhibitor iodoacetate prevented both butyrate- and tumor necrosis factor-alpha-(TNF-α) mediated increases in rates of lipolysis indicating glucose metabolism is required. However, unlike TNF-α– , butyrate-stimulated lipolysis was not associated with increased lactate release or inhibited by activation of pyruvate dehydrogenase (PDH) with dichloroacetate. These data demonstrate an important relationship between lipolytic activity and reported HDAC inhibitory activity of butyrate, other short-chain fatty acids and trichostatin A. Given that HDAC inhibitors are presently being evaluated for the treatment of diabetes and other disorders, more work will be essential to determine if these effects on lipolysis are due to inhibition of HDAC. PMID:25320679

Relationship between abdominal and pelvic floor muscle activation and intravaginal pressure during pelvic floor muscle contractions in healthy continent women.

PubMed

Madill, Stéphanie J; McLean, Linda

2006-01-01

Activation of the abdominal muscles might contribute to the generation of a strong pelvic floor muscle contraction, and consequently may contribute to the continence mechanism in women. The purpose of this study was to determine the abdominal muscle activation levels and the patterns of muscle activity associated with voluntary pelvic floor muscle (PFM) contractions in urinary continent women. Fifteen healthy continent women participated. They performed three maximal contractions of each of the four abdominal muscles and of their PFMs while in supine. Abdominal and PFM activity was recorded using electromyography (EMG), and intravaginal pressure was recorded using a custom modified Femiscan probe. During voluntary maximal PFM contractions, rectus abdominus was activated to 9.61 (+/-7.42)% maximal voluntary electrical activity (MVE), transversus abdominus was activated to 224.30(+/-47.4)% MVE, the external obliques were activated to 18.72(+/-13.33)% MVE, and the internal obliques were activated to 81.47(+/-63.57)% MVE. A clear pattern of activation emerged, whereby the transversus abdominus, internal oblique, and rectus abdominus muscles worked with the PFM in the initial generation of maximal intravaginal pressure. PFM activity predominated in the initial rise in lower vaginal pressure, with later increases in pressure (up to 70% maximum pressure) being associated with the combined activation of the PFM, rectus abdominus, internal obliques, and transverses abdominus. These abdominal muscles were the primary source of intravaginal pressure increases in the latter 30% of the task, whereas there was little increase in PFM activation from this point on. The external oblique muscles showed no clear pattern of activity, but worked at approximately 20% MVE throughout the PFM contractions, suggesting that their role may be predominantly in postural setting prior to the initiation of intravaginal pressure increases. Defined patterns of abdominal muscle activity were found in response to voluntary PFM contractions in healthy continent women. (c) 2006 Wiley-Liss, Inc.

Using cost-effectiveness analysis to prioritize policy and programmatic approaches to physical activity promotion and obesity prevention in childhood.

PubMed

Cradock, Angie L; Barrett, Jessica L; Kenney, Erica L; Giles, Catherine M; Ward, Zachary J; Long, Michael W; Resch, Stephen C; Pipito, Andrea A; Wei, Emily R; Gortmaker, Steven L

2017-02-01

Participation in recommended levels of physical activity promotes a healthy body weight and reduced chronic disease risk. To inform investment in prevention initiatives, we simulate the national implementation, impact on physical activity and childhood obesity and associated cost-effectiveness (versus the status quo) of six recommended strategies that can be applied throughout childhood to increase physical activity in US school, afterschool and childcare settings. In 2016, the Childhood Obesity Intervention Cost Effectiveness Study (CHOICES) systematic review process identified six interventions for study. A microsimulation model estimated intervention outcomes 2015-2025 including changes in mean MET-hours/day, intervention reach and cost per person, cost per MET-hour change, ten-year net costs to society and cases of childhood obesity prevented. First year reach of the interventions ranged from 90,000 youth attending a Healthy Afterschool Program to 31.3 million youth reached by Active School Day policies. Mean MET-hour/day/person increases ranged from 0.05 MET-hour/day/person for Active PE and Healthy Afterschool to 1.29 MET-hour/day/person for the implementation of New Afterschool Programs. Cost per MET-hour change ranged from cost saving to $3.14. Approximately 2500 to 110,000 cases of children with obesity could be prevented depending on the intervention implemented. All of the six interventions are estimated to increase physical activity levels among children and adolescents in the US population and prevent cases of childhood obesity. Results do not include other impacts of increased physical activity, including cognitive and behavioral effects. Decision-makers can use these methods to inform prioritization of physical activity promotion and obesity prevention on policy agendas. Copyright © 2016. Published by Elsevier Inc.

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

DOEpatents

Gschneidner, Jr., Karl A.; Pecharsky, Vitalij K.

1998-04-28

Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process

DOEpatents

Gschneidner, K.A. Jr.; Pecharsky, V.K.

1998-04-28

Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.

Activation of the surface dark-layer to enhance upconversion in a thermal field

NASA Astrophysics Data System (ADS)

Zhou, Jiajia; Wen, Shihui; Liao, Jiayan; Clarke, Christian; Tawfik, Sherif Abdulkader; Ren, Wei; Mi, Chao; Wang, Fan; Jin, Dayong

2018-03-01

Thermal quenching, in which light emission experiences a loss with increasing temperature, broadly limits luminescent efficiency at higher temperature in optical materials, such as lighting phosphors1-3 and fluorescent probes4-6. Thermal quenching is commonly caused by the increased activity of phonons that leverages the non-radiative relaxation pathways. Here, we report a kind of heat-favourable phonons existing at the surface of lanthanide-doped upconversion nanomaterials to combat thermal quenching. It favours energy transfer from sensitizers to activators to pump up the intermediate excited-state upconversion process. We identify that the oxygen moiety chelating Yb3+ ions, [Yb...O], is the key underpinning this enhancement. We demonstrate an approximately 2,000-fold enhancement in blue emission for 9.7 nm Yb3+-Tm3+ co-doped nanoparticles at 453 K. This strategy not only provides a powerful solution to illuminate the dark layer of ultra-small upconversion nanoparticles, but also suggests a new pathway to build high-efficiency upconversion systems.

Discovery and observation of BY Draconis variables

NASA Astrophysics Data System (ADS)

Bopp, B. W.; Noah, P. V.; Klimke, A.; Africano, J.

1981-10-01

The discovery of BY Draconis variables was efficiently accomplished by a spectroscopic survey of dK-M stars for weak H-alpha emissions, using 1-2 A resolution. The four BY Dra variables discovered are all spectroscopic binaries with P values lower than about 10 d, in light of which, it is noted that the onset of high surface activity and appearance of H-alpha emission occur sharply at v(equator) of approximately 5 km/sec. At v(equator) of about 3 km/sec, dK-M stars have low levels of surface activity. It is found that while there is a range of Ca II emission strength, and only the strongest emitters of this line are BY Dra and/or flare stars, the H-alpha feature changes abruptly to an emission feature signaling the onset of flaring and/or the BY Dra syndrome. An increase of the rotation rate above v(equator) 5 km/sec does not appear to increase the level of surface activity.

Induction of monooxygenation in rainbow trout by polybrominated biphenyls: a comparative study.

PubMed Central

Elcombe, C R; Lech, J J

1978-01-01

Two commercial polychlorinated biphenyl mixtures (Aroclor 1254 and Aroclor 1242) and one polybrominated biphenyl mixture (FireMaster BP-6) were examined for their abilities to induce hepatic microsomal monooxygenation in rainbow trout (Salmo gairdneri). Pretreatment of rainbow trout with Aroclors 1254 and 1242 (150 mg/kg IP) resulted in an approximate 10-fold induction of arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation within 7 days after injection. These enzyme activities remained elevated above control values for at least 2-3 weeks. Administration of FireMaster BP-6 (150 mg/kg IP) also resulted in an induction of several monooxygenase activities. Arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation were increased by 6-, 3,- and 25-fold, respectively. Only the latter two activities remained elevated two weeks post-injection. Ethylmorphine-N-demethylation was unaffected by the polyhalogenated biphenyls. Significant increases in P-450 hemoprotein were not observed after pretreatment with any of the polyhalogenated biphenyls studied. PMID:209992

Effect of torrefaction on the properties of rice straw high temperature pyrolysis char: Pore structure, aromaticity and gasification activity.

PubMed

Chen, Handing; Chen, Xueli; Qin, Yueqiang; Wei, Juntao; Liu, Haifeng

2017-03-01

The influence of torrefaction on the physicochemical characteristics of char during raw and water washed rice straw pyrolysis at 800-1200°C is investigated. Pore structure, aromaticity and gasification activity of pyrolysis chars are compared between raw and torrefied samples. For raw straw, BET specific surface area decreases with the increased torrefaction temperature at the same pyrolysis temperature and it approximately increases linearly with weight loss during pyrolysis. The different pore structure evolutions relate to the different volatile matters and pore structures between raw and torrefied straw. Torrefaction at higher temperature would bring about a lower graphitization degree of char during pyrolysis of raw straw. Pore structure and carbon crystalline structure evolutions of raw and torrefied water washed straw are different from these of raw straw during pyrolysis. For both raw and water washed straw, CO 2 gasification activities of pyrolysis chars are different between raw and torrefied samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of organic/inorganic hybrid gel with acid activated clay after γ-ray radiation.

PubMed

Kim, Donghyun; Lee, Hoik; Sohn, Daewon

2014-08-01

A hybrid gel was prepared from acid activated clay (AA clay) and acrylic acid by gamma ray irradiation. Irradiated inorganic particles which have peroxide groups act as initiator because it generates oxide radicals by increasing temperature. Inorganic nanoparticles which are rigid part in hybrid gel also contribute to increase the mechanical property as a crosslinker. We prepared two hybrid gels to compare the effect of acid activated treatment of clay; one is synthesized with raw clay particles and another is synthesized with AA clay particles. The composition and structure of AA clay particles and raw clay particles were confirmed by X-ray diffraction (XRD), X-ray fluorescence instrument and surface area analyzer. And chemical and physical property of hybrid gel with different ratios of acrylic acid and clay particle was tested by Raman spectroscope and universal testing machine (UTM). The synthesized hydrogel with 76% gel contents can elongated approximately 1000% of its original size.

Student knowledge and confidence in an elective clinical toxicology course using active-learning techniques.

PubMed

Thomas, Michael C; Macias-Moriarity, Liliairica Z

2014-06-17

To measure changes in students' knowledge and confidence scores after completing an elective clinical toxicology course in an accelerated doctor of pharmacy (PharmD) program. Various active-learning techniques were used to create a learner-centered environment. Approximately two-thirds of the course used student-led presentations. Some of those not presenting were assigned to be evaluators, responsible for asking the presenter a question or writing quiz questions based on the presented material. Other learner-centered activities included weekly quizzes and discussions at the conclusion of each presented topic. A test instrument designed to measure students' knowledge and associated level of confidence on each item was administered at the beginning and end of the course. Students' knowledge and confidence scores increased significantly from pretest to posttest. Students' increased confidence and knowledge scores were well correlated after course completion, indicating students were better able to self-assess these areas. These findings suggest that confidence could be an additional measure of students' metacognitive skill development.

A systematic resolution of sulfur in reticulated vitreous carbon using X-ray absorption spectroscopy.

PubMed

Frank, Patrick; George, Serena DeBeer; Anxolabéhère-Mallart, Elodie; Hedman, Britt; Hodgson, Keith O

2006-11-27

Sulfur K-edge X-ray absorption spectroscopy (XAS) was used to characterize the approximately 0.1% sulfur found both in native reticulated vitreous carbon (RVC) foam and in RVC oxidatively modified using 0.2 M KMnO4 in 2 M H2SO4. Sulfur valences and functional groups were assessed using K-edge XAS spectral curve-fitting and employing explicit sulfur compounds as models. For native RVC, these were episulfide (approximately 3%), thianthrene (approximately 9%), disulfide (approximately 10%), sulfenate ester (approximately 12%), benzothiophene (approximately 24%), N,N'-thiobisphthalimide (approximately 30%), alkyl sulfonate (approximately 1.2%), alkyl sulfate monoester (approximately 6%), and sulfate dianion (approximately 6%). Permanganate oxidation of RVC diminished sulfenic sulfur to approximately 9%, thianthrenic sulfur to approximately 7%, and sulfate dianion to approximately 1% but increased sulfate monoester to approximately 12%, and newly produced sulfone (approximately 2%) and sulfate diester (approximately 5%). A simple thermodynamic model was derived that allows proportionate functional group comparisons despite differing (approximately +/-15%) total sulfur contents between RVC batches. The limits of accuracy in the XAS curve-fitting analysis are discussed in terms of microenvironments and extended structures in RVC carbon that cannot be exactly modeled by small molecules. Sulfate esters cover approximately 0.15% of the RVC surface, increasing to approximately 0.51% following permanganate/sulfuric acid treatment. The detection of episulfide directly corroborates a proposed mechanism for the migration of elemental sulfur through carbon.

Regulation of muscle stiffness during periodic length changes in the isolated abdomen of the hermit crab.

PubMed

Chapple, W D

1997-09-01

Reflex activation of the ventral superficial muscles (VSM) in the abdomen of the hermit crab, Pagurus pollicarus, was studied using sinusoidal and stochastic longitudinal vibration of the muscle while recording the length and force of the muscle and the spike times of three exciter motoneurons. In the absence of vibration, the interspike interval histograms of the two larger motoneurons were bimodal; cutting sensory nerves containing most of the mechanoreceptor input removed the short interval peak in the histogram, indicating that the receptors are important in maintaining tonic firing. Vibration of the muscle evoked a reflex increase in motoneuron frequency that habituated after an initial peak but remained above control levels for the duration of stimulation. Motoneuron frequency increased with root mean square (rms) stimulus amplitude. Average stiffness during stimulation was about two times the stiffness of passive muscle. The reflex did not alter muscle dynamics. Estimated transfer functions were calculated from the fast Fourier transform of length and force signals. Coherence was >0.9 for the frequency range of 3-35 Hz. Stiffness magnitude gradually increased over this range in both reflex activated and passive muscle; phase was between 10 and 20 degrees. Reflex stiffness decreased with increasing stimulus amplitudes, but at larger amplitudes, this decrease was much less pronounced; in this range stiffness was regulated by the reflex. The sinusoidal frequency at which reflex bursts were elicited was approximately 6 Hz, consistent with previous measurements using ramp stretch. During reflex excitation, there was an increase in amplitude of the short interval peak in the interspike interval histogram; this was reduced when the majority of afferent pathways was removed. A phase histogram of motoneuron firing during sinusoidal vibration had a peak at approximately 110 ms, also suggesting that an important component of the reflex is via direct projections from the mechanoreceptors. These results are consistent with the hypothesis that a robust feedforward regulation of abdominal stiffness during continuous disturbances is achieved by mechanoreceptors signalling the absolute value of changing forces; habituation of the reflex, its high-threshold for low frequency disturbances and the activation kinetics of the muscle further modify reflex dynamics.

Expression of a truncated human tau protein induces aqueous-phase free radicals in a rat model of tauopathy: implications for targeted antioxidative therapy.

PubMed

Cente, Martin; Filipcik, Peter; Mandakova, Stanislava; Zilka, Norbert; Krajciova, Gabriela; Novak, Michal

2009-01-01

Oxidative stress has been implicated in the pathogenesis of many neurodegenerative diseases including Alzheimer's disease (AD). We investigated the effect of a truncated form of the human tau protein in the neurons of transgenic rats. Using electron paramagnetic resonance we observed significantly increased accumulation of ascorbyl free radicals in brains of transgenic animals (up to 1.5-fold increase; P < 0.01). Examination of an in vitro model of cultured rat corticohippocampal neurons revealed that even relatively low level expression of human truncated tau protein (equal to 50% of endogenous tau) induced oxidative stress that resulted in increased depolarization of mitochondria (approximately 1.2-fold above control, P < 0.01) and increases in reactive oxygen species (approximately 1.3-fold above control, P < 0.001). We show that mitochondrial damage-associated oxidative stress is an early event in neurodegeneration. Furthermore, using two common antioxidants (vitamin C and E), we were able significantly eliminate tau-induced elevation of reactive oxygen species. Interestingly, vitamin C was found to be selective in the scavenging activity, suggesting that expression of truncated tau protein preferentially leads to increases in aqueous phase oxidants and free radicals such as hydrogen peroxide and hydroxyl and superoxide radicals. Our results suggest that antioxidant strategies designed to treat AD should focus on elimination of aqueous phase oxidants and free radicals.

Stereochemical analysis of the functional significance of the conserved inverted CCAAT and TATA elements in the rat bone sialoprotein gene promoter.

PubMed

Su, Ming; Lee, Daniel; Ganss, Bernhard; Sodek, Jaro

2006-04-14

Basal transcription of the bone sialoprotein gene is mediated by highly conserved inverted CCAAT (ICE; ATTGG) and TATA elements (TTTATA) separated by precisely 21 nucleotides. Here we studied the importance of the relative position and orientation of the CCAAT and TATA elements in the proximal promoter by measuring the transcriptional activity of a series of mutated reporter constructs in transient transfection assays. Whereas inverting the TTTATA (wild type) to a TATAAA (consensus TATA) sequence increased transcription slightly, transcription was reduced when the flanking dinucleotides were also inverted. In contrast, reversing the ATTGG (wild type; ICE) to a CCAAT (RICE) sequence caused a marked reduction in transcription, whereas both transcription and NF-Y binding were progressively increased with the simultaneous inversion of flanking nucleotides (f-RICE-f). Reducing the distance between the ICE and TATA elements produced cyclical changes in transcriptional activity that correlated with progressive alterations in the relative positions of the CCAAT and TATA elements on the face of the DNA helix. Minimal transcription was observed after 5 nucleotides were deleted (equivalent to approximately one half turn of the helix), whereas transcription was fully restored after deleting 10 nucleotides (approximately one full turn of the DNA helix), transcriptional activity being progressively lost with deletions beyond 10 nucleotides. In comparison, when deletions were made with the ICE in the reversed (f-RICE-f) orientation transcriptional activity was progressively lost with no recovery. These results show that, although transcription can still occur when the CCAAT box is reversed and/or displaced relative to the TATA box, the activity is dependent upon the flexibility of the intervening DNA helix needed to align the NF-Y complex on the CCAAT box with preinitiation complex proteins that bind to the TATA box. Thus, the precise location and orientation of the CCAAT element is necessary for optimizing basal transcription of the bone sialoprotein gene.

Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams

USGS Publications Warehouse

Gulis, V.; Rosemond, A.D.; Suberkropp, K.; Weyers, H.S.; Benstead, J.P.

2004-01-01

1. We determined the effects of nutrient enrichment on wood decomposition rates and microbial activity during a 3-year study in two headwater streams at Coweeta Hydrologic Laboratory, NC, U.S.A. After a 1-year pretreatment period, one of the streams was continuously enriched with inorganic nutrients (nitrogen and phosphorus) for 2 years while the other stream served as a reference. We determined the effects of enrichment on both wood veneers and sticks, which have similar carbon quality but differ in physical characteristics (e.g. surface area to volume ratios, presence of bark) that potentially affect microbial colonisation and activity. 2. Oak wood veneers (0.5 mm thick) were placed in streams monthly and allowed to decompose for approximately 90 days. Nutrient addition stimulated ash-free dry mass loss and increased mean nitrogen content, fungal biomass and microbial respiration on veneers in the treatment stream compared with the reference. The magnitude of the response to enrichment was great, with mass loss 6.1 times, and per cent N, fungal biomass and microbial respiration approximately four times greater in the treatment versus reference stream. 3. Decomposition rate and nitrogen content of maple sticks (ca. 1-2 cm diameter) also increased; however, the effect was less pronounced than for veneers. Wood response overall was greater than that determined for leaves in a comparable study, supporting the hypothesis that response to enrichment may be greater for lower quality organic matter (high C:N) than for higher quality (low C:N) substrates. 4. Our results show that moderate nutrient enrichment can profoundly affect decomposition rate and microbial activity on wood in streams. Thus, the timing and availability of wood that provides retention, structure, attachment sites and food in stream ecosystems may be affected by nutrient concentrations raised by human activities.

Beet sugar syrup and molasses as low-cost feedstock for the enzymatic production of fructo-oligosaccharides.

PubMed

Ghazi, Iraj; Fernandez-Arrojo, Lucia; Gomez De Segura, Aranzazu; Alcalde, Miguel; Plou, Francisco J; Ballesteros, Antonio

2006-04-19

Sugar syrup and molasses from beet processing containing 620 and 570 mg/mL sucrose, respectively, were assayed as low-cost and available substrates for the enzymatic synthesis of fructo-oligosaccharides (FOSs). A commercial pectinase (Pectinex Ultra SP-L, from Aspergillus aculeatus) characterized by the presence of a transfructosylating activity was used as a biocatalyst. The FOS production increased when lowering the initial pH value of syrup (7.5) and molasses (8.9) to 5.5. Sugar syrup and molasses were diluted in order to reduce substrate viscosity; interestingly, the percentage of FOS with regards to total sugars remained almost constant, which indicated a high transferase-to-hydrolase ratio for this enzyme. Kinetics of FOS production was analyzed. Using approximately 10 U transfructosylating activity per g sucrose, the FOS concentration reached a maximum of 388 mg/mL after 30 h using syrup and 235 mg/mL in 65 h with molasses. These values corresponded to approximately 56 and 49% (w/w), respectively, of the total amount of carbohydrates in the mixture. The enzyme was also covalently immobilized on an epoxy-activated polymethacrylate-based polymer (Sepabeads EC-EP5). We found that immobilized Pectinex Ultra SP-L can be efficiently applied to the synthesis of FOS using syrup and molasses as substrates.

Long-term study of 99Tc in the marine environment on the Swedish west coast.

PubMed

Lindahl, P; Ellmark, C; Gäfvert, T; Mattsson, S; Roos, P; Holm, E; Erlandsson, B

2003-01-01

The activity concentration of (99)Tc in brown seaweed (Fucus vesiculosus and Fucus serratus) and seawater were analysed in samples collected in 1991, 1995 and 2001 at several stations along the Swedish west coast. In addition to these locations, a well-defined site (Särdal, 56.76 degrees N, 12.63 degrees E) was included with (99)Tc activity concentration data in seaweed from 1967 to 2000. Over the years, the major source of (99)Tc in the coastal waters of western Sweden has been the radioactive liquid discharge from the nuclear fuel reprocessing plant in Sellafield (UK) transported via ocean currents in the North Sea. The (99)Tc activity concentration in seaweed at the Särdal site increased from approximately 30 Bq kg(-1) up to 230 Bq kg(-1) (dry weight) between 1997 and 2000 due to the Sellafield EARP (Enhanced Actinide Removal Plant) discharges in 1995-1996, yielding an approximate transport time of 4-5 years between the Irish Sea and the Kattegat. Due to the very sharp gradient in (99)Tc concentration between the Baltic Sea and the North Sea, (99)Tc is presently one of the best transit tracers for the recent ventilation events in the Baltic Sea.

Identification of human pulmonary alkaline phosphatase isoenzymes.

PubMed

Capelli, A; Cerutti, C G; Lusuardi, M; Donner, C F

1997-04-01

An increase of alkaline phosphatase (ALP) activity has been observed in the bronchoalveolar lavage fluid (BALF) of patients affected by pulmonary fibrosis in chronic interstitial lung disorders. To characterize the ALP isoenzymes in such cases, we used gel filtration, agarose gel electrophoresis, heat and amino acid inhibition assays, wheat-germ agglutinin (WGA) precipitation, and an immunoassay specific for the bone-isoform of ALP. Only one anodic band representing a high-molecular-weight isoform of ALP (Mr approximately 2,000 kDa) was observed on electrophoresis of BALF. The inhibition assay results were consistent for a tissue-nonspecific isoenzyme sensitive to a temperature of 56 degrees C (71.9 +/- 2.5% inhibition) and to homoarginine (65.7 +/- 1.9%), and resistant to L-phenylalanine and L-leucine. Less than 13% of ALP activity was heat-stable. After incubation of BALF specimens with glycosyl-phosphatidylinositol-phospholipase D plus Nonidet P-40, or with phosphatidylinositol-phospholipase C alone, an electrophoretic cathodic band (Mr approximately 220 kDa) appeared near the bone band of a standard serum. With the WGA assay, 84.4 +/- 3.3% of ALP precipitated and the band disappeared. After immunoassay for the bone isoform, a mean of less than 5% enzyme activity was measured. We conclude that the ALP found in BALF is a pulmonary isoform of a tissue nonspecific isoenzyme.

The Nature of the Unresolved Extragalactic Cosmic Soft X-Ray Background

NASA Technical Reports Server (NTRS)

Cappelluti, N.; Ranalli, P.; Roncarelli, M.; Arevalo, P.; Zamorani, G.; Comastri, A.; Gilli, R.; Rovilos, E.; Vignali, C.; Allevato, V.;

Multivariate moment closure techniques for stochastic kinetic models

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

Lakatos, Eszter, E-mail: e.lakatos13@imperial.ac.uk; Ale, Angelique; Kirk, Paul D. W.

2015-09-07

Stochastic effects dominate many chemical and biochemical processes. Their analysis, however, can be computationally prohibitively expensive and a range of approximation schemes have been proposed to lighten the computational burden. These, notably the increasingly popular linear noise approximation and the more general moment expansion methods, perform well for many dynamical regimes, especially linear systems. At higher levels of nonlinearity, it comes to an interplay between the nonlinearities and the stochastic dynamics, which is much harder to capture correctly by such approximations to the true stochastic processes. Moment-closure approaches promise to address this problem by capturing higher-order terms of the temporallymore » evolving probability distribution. Here, we develop a set of multivariate moment-closures that allows us to describe the stochastic dynamics of nonlinear systems. Multivariate closure captures the way that correlations between different molecular species, induced by the reaction dynamics, interact with stochastic effects. We use multivariate Gaussian, gamma, and lognormal closure and illustrate their use in the context of two models that have proved challenging to the previous attempts at approximating stochastic dynamics: oscillations in p53 and Hes1. In addition, we consider a larger system, Erk-mediated mitogen-activated protein kinases signalling, where conventional stochastic simulation approaches incur unacceptably high computational costs.« less

Electrophysiological characterization of harmane-induced activation of mesolimbic dopamine neurons.

PubMed

Arib, Ouafa; Rat, Pascal; Molimard, Robert; Chait, Abderrahman; Faure, Philippe; de Beaurepaire, Renaud

2010-03-10

It has been suggested that the beta-carbolines harmane and norharmane may be involved in the pathophysiology of Parkinson's disease, psychosis and addiction, but the mechanisms of these possible effects remain to be elucidated. In the present study, the effects of the two compounds were examined by using in vivo extracellular recordings of ventral tegmental dopamine neurons. The effects of harmane (2mg/kg) and norharmane (2mg/kg), were compared to those of nicotine (11microg/kg), of cotinine (0.5mg/kg), of the monoamine-oxidase-A inhibitor befloxatone (0.12mg/kg), and of the monoamine-oxidase-B inhibitor selegiline (0.5mg/kg). The effects of harmane were also tested after pre-treatment with the nicotine receptor antagonist mecamylamine. The results show that all substances, except befloxatone, activate the firing and/or burst activity of dopamine neurons. The increase in firing rate produced by harmane was approximately 18 times greater than that produced by nicotine. Such powerful excitation of dopamine neurons by harmane may in part explain its involvement in neurotoxicity, psychosis and addiction. The absence of effect of befloxatone supports the hypothesis that the effect of harmane is not related to its monoamine-oxidase-A inhibitory properties. Mecamylamine inhibited by approximately 80% the activity of harmane, indicating that the activating effect of harmane on dopamine neurons involves several mechanisms, among which activation of nicotinic receptors likely has a prominent importance. The results of the present study support the hypothesis that harmane could be a tobacco (or smoke) component other than nicotine involved in tobacco dependence. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Bcl-2△21 and Ac-DEVD-CHO Inhibit Death of Wheat Microspores

PubMed Central

Sinha, Rakesh K.; Pospíšil, Pavel; Maheshwari, Priti; Eudes, François

2016-01-01

Microspore cell death and low green plant production efficiency are an integral obstacle in the development of doubled haploid production in wheat. The aim of the current study was to determine the effect of anti-apoptotic recombinant human B-cell lymphoma-2 (Bcl-2△21) and caspase-3-inhibitor (Ac-DEVD-CHO) in microspore cell death in bread wheat cultivars AC Fielder and AC Andrew. Induction medium containing Bcl-2△21 and Ac-DEVD-CHO yielded a significantly higher number of viable microspores, embryo-like structures and total green plants in wheat cultivars AC Fielder and AC Andrew. Total peroxidase activity was lower in Bcl-2△21 treated microspore cultures at 96 h of treatment compared to control and Ac-DEVD-CHO. Electron paramagnetic resonance study of total microspore protein showed a different scavenging activity for Bcl-2△21 and Ac-DEVD-CHO. Bcl-2△21 scavenged approximately 50% hydroxyl radical (HO•) formed, whereas Ac-DEVD-CHO scavenged approximately 20% of HO•. Conversely, reduced caspase-3-like activities were detected in the presence of Bcl-2△21 and Ac-DEVD-CHO, supporting the involvement of Bcl-2△21 and Ac-DEVD-CHO in increasing microspore viability by reducing oxidative stress and caspase-3-like activity. Our results indicate that Bcl-2△21 and Ac-DEVD-CHO protects cells from cell death following different pathways. Bcl-2△21 prevents cell damage by detoxifying HO• and suppressing caspase-3-like activity, while Ac-DEVD-CHO inhibits the cell death pathways by modulating caspase-like activity. PMID:28082995

Minimal-Approximation-Based Distributed Consensus Tracking of a Class of Uncertain Nonlinear Multiagent Systems With Unknown Control Directions.

PubMed

Choi, Yun Ho; Yoo, Sung Jin

2017-03-28

A minimal-approximation-based distributed adaptive consensus tracking approach is presented for strict-feedback multiagent systems with unknown heterogeneous nonlinearities and control directions under a directed network. Existing approximation-based consensus results for uncertain nonlinear multiagent systems in lower-triangular form have used multiple function approximators in each local controller to approximate unmatched nonlinearities of each follower. Thus, as the follower's order increases, the number of the approximators used in its local controller increases. However, the proposed approach employs only one function approximator to construct the local controller of each follower regardless of the order of the follower. The recursive design methodology using a new error transformation is derived for the proposed minimal-approximation-based design. Furthermore, a bounding lemma on parameters of Nussbaum functions is presented to handle the unknown control direction problem in the minimal-approximation-based distributed consensus tracking framework and the stability of the overall closed-loop system is rigorously analyzed in the Lyapunov sense.

Kinetic and pharmacological properties distinguishing three types of calcium currents in chick sensory neurones.

PubMed Central

Fox, A P; Nowycky, M C; Tsien, R W

1987-01-01

1. Calcium currents in cultured dorsal root ganglion (d.r.g.) cells were studied with the whole-cell patch-clamp technique. Using experimental conditions that suppressed Na+ and K+ currents, and 3-10 mM-external Ca2+ or Ba2+, we distinguished three distinct types of calcium currents (L, T and N) on the basis of voltage-dependent kinetics and pharmacology. 2. Component L activates at relatively positive test potentials (t.p. greater than -10 mV) and shows little inactivation during a 200 ms depolarization. It is completely reprimed at a holding potential (h.p.) of -60 mV, and can be isolated by using a more depolarized h.p. (-40 mV) to inactivate the other two types of calcium currents. 3. Component T can be seen in isolation with weak test pulses. It begins activating at potentials more positive than -70 mV and inactivates quickly and completely during a maintained depolarization (time constant, tau approximately 20-50 ms). The current amplitude and the rate of decay increase with stronger depolarizations until both reach a maximum at approximately -40 mV. Inactivation is complete at h.p. greater than -60 mV and is progressively removed between -60 and -95 mV. 4. Component N activates at relatively strong depolarizations (t.p. greater than -20 mV) and decays with time constants ranging from 50 to 110 ms. Inactivation is removed over a very broad range of holding potentials (h.p. between -40 and -110 mV). 5. With 10 mM-EGTA in the pipette solution, substitution of Ba2+ for Ca2+ as the charge carrier does not alter the rates of activation or relaxation of any component. However, T-type channels are approximately equally permeable to Ca2+ and Ba2+, while L-type and N-type channels are both much more permeable to Ba2+. 6. Component N cannot be explained by current-dependent inactivation of L current resulting from recruitment of extra L-type channels at negative holding potentials: raising the external Ba2+ concentration to 110 mM greatly increases the amplitude of L current evoked from h.p. = -30 mV but produces little inactivation. 7. Cadmium ions (20-50 microM) virtually eliminate both N and L currents (greater than 90% block) but leave T relatively unaffected (less than 50% block). 200 microM-Cd2+ blocks all three components. 8. Nickel ions (100 microM) strongly reduce T current but leave N and L current little changed. 9. The dihydropyridine antagonist nifedipine (10 microM) inhibits L current (approximately 60% block) at a holding potential that inactivates half the L-type channels.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2451016

Do adolescent leisure-time physical activities foster health and well-being in adulthood? Evidence from two British birth cohorts.

PubMed

Sacker, Amanda; Cable, Noriko

2006-06-01

Calls for public health initiatives to increase adolescent leisure-time physical activity suggest that increasing activity in this age group will reduce social inequalities in health. While the public health benefits of exercise are undisputed, there is little evidence on its role in reducing health inequalities. The paper examines the extent to which adolescent leisure-time physical activity promotes adult health and well-being and explores whether adolescent leisure-time physical activity can act to reduce health inequalities arising from material deprivation during childhood. This is a longitudinal study of the 1958 British birth cohort followed from age 16 to age 33 years (N = 15,452) and the 1970 British birth cohort followed to age 30 years (N = 14,018). Adult self-rated general health and Malaise Inventory scores are regressed on self-reports of leisure time physical activity. Analyses are conducted separately for men and women controlling for adolescent body mass index (BMI) and psychosocial problems. There was a consistent relationship between leisure-time physical activity in adolescence and psychological well-being approximately 15 years later for both the cohorts. This relationship was independent of adolescent BMI and psychosocial problems. More physical activity in adolescence predicted better adult self-assessed health in the 1958 cohort only. Leisure-time physical activity did not affect inequalities in health. Policies aimed at increasing participation in leisure-time physical activities in youth may improve population health but are unlikely to prevent the development of social inequalities in health.

Enhanced tissue factor pathway activity and fibrin turnover in the alveolar compartment of patients with interstitial lung disease.

PubMed

Günther, A; Mosavi, P; Ruppert, C; Heinemann, S; Temmesfeld, B; Velcovsky, H G; Morr, H; Grimminger, F; Walmrath, D; Seeger, W

2000-06-01

Bronchoalveolar lavage fluids (BALF) from patients with hypersensitivity pneumonitis (HP; n = 35), idiopathic pulmonary fibrosis (IPF, n = 41) and sarcoidosis (SARC, n = 48) were investigated for alterations in the alveolar hemostatic balance. Healthy individuals (n = 21) served as Controls. Procoagulant activity (PCA), tissue factor (TF) activity and F VII activity were assessed by means of specific recalcification assays. The overall fibrinolytic activity (FA) was measured using the (125)I-labeled fibrin plate assay. Fibrinopeptide A (FP-A), D-Dimer, plasminogen activators (PA) of the urokinase (u-PA) or tissue type (t-PA), PA-inhibitor I (PAI-1) and alpha2-antiplasmin (alpha2-AP) were determined by ELISA technique. As compared to Controls, all groups with interstitial lung disease (ILD) displayed an increase in BALF PCA by approximately one order of magnitude, and this was ascribed to enhanced TF activity by >98%. Accordingly, F VII-activity was increased in all ILD groups, and elevated FP-A levels were noted. There was no significant difference in procoagulant activities between the different ILD entities, but the increase in TF was significantly correlated with deterioration of lung compliance. Overall fibrinolytic activity did not significantly differ between ILD entities and Controls, although some reduction in IPF subjects was observed. Nevertheless, changes in the profile of the different pro- and antifibrinolytic compounds were noted. U-PA, but not t-PA levels were significantly reduced in all ILD groups. alpha2-AP was markedly elevated throughout, whereas PAI-1 levels were lowered. As a balance of

Complementary rare earth element patterns in unique achondrites, such as ALHA 77005 and shergottites, and in the earth

NASA Technical Reports Server (NTRS)

Ma, M.-S.; Schmitt, R. A.; Laul, J. C.

1982-01-01

Abundances of major, minor, and trace elements are determined in the Antarctic achondrite Allan Hills (ALHA) 77005 via sequential instrumental and radiochemical neutron activation analysis. The rare earth element (REE) abundances of ALHA 77005 reveal a unique chondritic normalized pattern; that is, the REEs are nearly unfractionated from La to Pr at approximately 1.0X chondrites, monotonically increased from Pr to Gd at approximately 3.4X with no Eu anomaly, nearly unfractionated from Gd and Ho and monotonically decreased from Ho to Lu at approximately 2.2X. It is noted that this unique REE pattern of ALHA 77005 can be modeled by a melting process involving a continuous melting and progressive partial removal of melt from a light REE enriched source material. In a model of this type, ALHA 77005 could represent either a crystallized cumulate from such a melt or the residual source material. Calculations show that the parent liquids for the shergottites could also be derived from a light REE enriched source material similar to that for ALHA 77005.

Effect of weather on Ips typographus (Coleoptera Curculionidae) phenology, voltinism, and associated spruce mortality in the southeastern Alps.

PubMed

Faccoli, Massimo

2009-04-01

Summer drought associated with high temperatures recorded in the last few years has given rise to outbreaks of bark beetles developing in weakened host trees. The aim of this study was to investigate the possible weather effect on the biology of and damage caused by Ips typographus L. in the southeastern Alps. The study was carried out recording temperature (1962-2007), precipitation (1922-2007), and the damage caused by I. typographus (1993-2007). In addition, data from pheromone-baited traps (1996-2005) provided information on the main periods of flight activity of I. typographus. From 1922 to 2007, precipitation during March-July has decreased approximately 200 mm (-22%), whereas since 1962-2007, mean temperatures during March-July increased approximately 2 degrees C (+13%). Damage caused by I. typographus was inversely correlated with March-July precipitation from the previous year but not correlated with temperature. Increases in spring temperature did not affect the development timing of the first generation, but only changed its onset. Earlier swarming of both overwintering beetles and first-generation offspring ( approximately 20 d sooner over 10 yr), and the early start of the second generation permitted more complete development of the second brood. Voltinism in this species is discussed in relation to thermal and photoperiodic thresholds, indicating that the occurrence of a third generation is limited by the summer photoperiod rather than by temperature. In conclusion, results suggest that spring drought increases damage caused by I. typographus in the following year, whereas warmer spring affects insect phenology.

Impact of Urbanization on Precipitation Distribution and Intensity over Lake Victoria Basin

NASA Astrophysics Data System (ADS)

Gudoshava, M.; Semazzi, F. H. M.

2014-12-01

In this study, sensitivity simulations on the impact of rapid urbanization over Lake Victoria Basin in East Africa were done using a Regional Climate Model (RegCM4.4-rc29) with the Hostetler lake model activated. The simulations were done for the rainy seasons that is the long rains (March-April-May) and short rains (October-November-December). Africa is projected to have a surge in urbanization with an approximate rate of 590% in 2030 over their 2000 levels. The Northern part of Lake Victoria Basin and some parts of Rwanda and Burundi are amongst the regions with high urbanization projections. Simulations were done with the land cover for 2000 and the projected 2030 urbanization levels. The results showed that increasing the urban fraction over the northern part of the basin modified the physical parameters such as albedo, moisture and surface energy fluxes, aerodynamic roughness and surface emissivity, thereby altering the precipitation distribution, intensity and frequency in the region. The change in the physical parameters gave a response of an average increase in temperature of approximately 2oC over the urbanized region. A strong convergence zone was formed over the urbanized region and thereby accelerating the lake-breeze front towards the urbanized region center. Precipitation in the urbanized region and regions immediate to the area increased by approximately 4mm/day, while drying up the southern (non-urbanized) side of the basin. The drying up of the southern side of the basin could be a result of divergent flow and subsidence that suppresses vertical development of storms.

Accelerated step-temperature aging of Al/x/Ga/1-x/As heterojunction laser diodes

NASA Technical Reports Server (NTRS)

Kressel, H.; Ettenberg, M.; Ladany, I.

1978-01-01

Double-heterojunction A2(0.3)Ga(0.7)As/Al(0.08)Ga(0.92)As lasers (oxide-striped and Al2O3 facet coated) were subjected to step-temperature aging from 60 to 100 C. The change in threshold current and spontaneous output was monitored at 22 C. The average time required for a 20% pulsed threshold current increase ranges from about 500 h, when operating at 100 C, to about 5000 h at a 70 C ambience. At 22 C, the extrapolated time is about 1 million h. The time needed for a 50% spontaneous emission reduction is of the same order of magnitude. The resulting activation energies are approximately 0.95 eV for laser degradation and approximately 1.1 eV for the spontaneous output decrease

Venous levels of shear support neutrophil-platelet adhesion and neutrophil aggregation in blood via P-selectin and beta2-integrin

NASA Technical Reports Server (NTRS)

Konstantopoulos, K.; Neelamegham, S.; Burns, A. R.; Hentzen, E.; Kansas, G. S.; Snapp, K. R.; Berg, E. L.; Hellums, J. D.; Smith, C. W.; McIntire, L. V.;

Venous levels of shear support neutrophil-platelet adhesion and neutrophil aggregation in blood via P-selectin and beta2-integrin.

PubMed

Konstantopoulos, K; Neelamegham, S; Burns, A R; Hentzen, E; Kansas, G S; Snapp, K R; Berg, E L; Hellums, J D; Smith, C W; McIntire, L V; Simon, S I

1998-09-01

After activation, platelets adhere to neutrophils via P-selectin and beta2-integrin. The molecular mechanisms and adhesion events in whole blood exposed to venous levels of hydrodynamic shear in the absence of exogenous activation remain unknown. Whole blood was sheared at approximately 100 s(-1). The kinetics of neutrophil-platelet adhesion and neutrophil aggregation were measured in real time by flow cytometry. P-selectin was upregulated to the platelet surface in response to shear and was the primary factor mediating neutrophil-platelet adhesion. The extent of neutrophil aggregation increased linearly with platelet adhesion to neutrophils. Blocking either P-selectin, its glycoprotein ligand PSGL-1, or both simultaneously by preincubation with a monoclonal antibody resulted in equivalent inhibition of neutrophil-platelet adhesion (approximately 30%) and neutrophil aggregation (approximately 70%). The residual amount of neutrophil adhesion was blocked with anti-CD11b/CD18. Treatment of blood with prostacyclin analogue ZK36374, which raises cAMP levels in platelets, blocked P-selectin upregulation and neutrophil aggregation to baseline. Complete abrogation of platelet-neutrophil adhesion required both ZK36374 and anti-CD18. Electron microscopic observations of fixed blood specimens revealed that platelets augmented neutrophil aggregation both by forming bridges between neutrophils and through contact-mediated activation. The results are consistent with a model in which venous levels of shear support platelet adherence to neutrophils via P-selectin binding PSGL-1. This interaction alone is sufficient to mediate neutrophil aggregation. Abrogation of platelet adhesion and aggregation requires blocking Mac-1 in addition to PSGL-1 or P-selectin. The described mechanisms are likely of key importance in the pathogenesis and progression of thrombotic disorders that are exacerbated by leukocyte-platelet aggregation.

Transcriptome and proteome analysis of tyrosine kinase inhibitor treated canine mast cell tumour cells identifies potentially kit signaling-dependent genes

PubMed Central

2012-01-01

Background Canine mast cell tumour proliferation depends to a large extent on the activity of KIT, a tyrosine kinase receptor. Inhibitors of the KIT tyrosine kinase have recently been introduced and successfully applied as a therapeutic agent for this tumour type. However, little is known on the downstream target genes of this signaling pathway and molecular changes after inhibition. Results Transcriptome analysis of the canine mast cell tumour cell line C2 treated for up to 72 hours with the tyrosine kinase inhibitor masitinib identified significant changes in the expression levels of approximately 3500 genes or 16% of the canine genome. Approximately 40% of these genes had increased mRNA expression levels including genes associated with the pro-proliferative pathways of B- and T-cell receptors, chemokine receptors, steroid hormone receptors and EPO-, RAS and MAP kinase signaling. Proteome analysis of C2 cells treated for 72 hours identified 24 proteins with changed expression levels, most of which being involved in gene transcription, e.g. EIA3, EIA4, TARDBP, protein folding, e.g. HSP90, UCHL3, PDIA3 and protection from oxidative stress, GSTT3, SELENBP1. Conclusions Transcriptome and proteome analysis of neoplastic canine mast cells treated with masitinib confirmed the strong important and complex role of KIT in these cells. Approximately 16% of the total canine genome and thus the majority of the active genes were significantly transcriptionally regulated. Most of these changes were associated with reduced proliferation and metabolism of treated cells. Interestingly, several pro-proliferative pathways were up-regulated, which may represent attempts of masitinib treated cells to activate alternative pro-proliferative pathways. These pathways may contain hypothetical targets for a combination therapy with masitinib to further improve its therapeutic effect. PMID:22747577

Mn-doping-induced photocatalytic activity enhancement of ZnO nanorods prepared on glass substrates

NASA Astrophysics Data System (ADS)

Putri, Nur Ajrina; Fauzia, Vivi; Iwan, S.; Roza, Liszulfah; Umar, Akrajas Ali; Budi, Setia

2018-05-01

Mn-doped ZnO nanorods were synthesized on glass substrates via a two-steps process of ultrasonic spray pyrolysis and hydrothermal methods with four different concentrations Mn-doping (0, 1, 3, and 7 mol%). Introduction of Mn into ZnO is known could enhance the photocatalytic activity owing to the increase in the defect sites that effectively suppress the recombination of free electrons and holes. In this study, results show that Mn-doping has effectively modified the nucleations and crystal growth of ZnO, as evidenced by the increasing in the diameter, height, and the number of nanorods per unit area, besides slightly reduced the band gap and increased the oxygen vacancy concentrations in the ZnO lattice. This condition has successfully multiplied the photocatalytic performance of the ZnO nanorods in the degradation of methylene blue (MB) compared to the undoped-ZnO sample where in the typical process the MB can be degraded approximately 77% within only 35 min under a UV light irradiation.

Dust Grains and the Luminosity of Circumnuclear Water Masers in Active Galaxies

NASA Technical Reports Server (NTRS)

Collison, Alan J.; Watson, William D.

1995-01-01

In previous calculations for the luminosities of 22 GHz water masers, the pumping is reduced and ultimately quenched with increasing depth into the gas because of trapping of the infrared (approximately equals 30-150 micrometers), spectral line radiation of the water molecule. When the absorption (and reemission) of infrared radiation by dust grains is included, we demonstrate that the pumping is no longer quenched but remains constant with increasing optical depth. A temperature difference between the grains and the gas is required. Such conditions are expected to occur, for example, in the circumnuclear masing environments created by X-rays in active galaxies. Here, the calculated 22 GHz maser luminosities are increased by more than an order of magnitude. Application to the well-studied, circumnuclear masing disk in the galaxy NGC 4258 yields a maser luminosity near that inferred from observations if the observed X-ray flux is assumed to be incident onto only the inner surface of the disk.

Comparison of the performance of the activPAL Professional physical activity logger to a discrete accelerometer-based activity monitor.

PubMed

Godfrey, A; Culhane, K M; Lyons, G M

2007-10-01

The aim of this study was to assess the accuracy of the 'activPAL Professional' physical activity logger by comparing its output to that of a proven discrete accelerometer-based activity monitor during extended measurements on healthy subjects while performing activities of daily living (ADL). Ten healthy adults, with unrestricted mobility, wore both the activPAL and the discrete dual accelerometer (Analog Devices ADXL202)-based activity monitor that recorded in synchronization with each other. The accelerometer derived data were then compared to that generated by the activPAL and a complete statistical and error analysis was performed using a Matlab program. This program determined trunk and thigh inclination angles to distinguish between sitting/lying, standing and stepping for the discrete accelerometer device and amount of time spent on each activity. Analysis was performed on a second-by-second basis and then categorized at 15s intervals in direct comparison with the activPAL generated data. Of the total time monitored (approximately 60 h) the detection accuracies for static and dynamic activities were approximately 98%. In a population of healthy adults, the data obtained from the activPAL Professional physical activity logger for both static and dynamic activities showed a close match to a proven discrete accelerometer data with an offset of approximately 2% between the two systems.

Parallelism Effects and Verb Activation: The Sustained Reactivation Hypothesis

ERIC Educational Resources Information Center

Callahan, Sarah M.; Shapiro, Lewis P.; Love, Tracy

2010-01-01

This study investigated the processes underlying parallelism by evaluating the activation of a parallel element (i.e., a verb) throughout "and"-coordinated sentences. Four points were tested: (1) approximately 1,600ms after the verb in the first conjunct (PP1), (2) immediately following the conjunction (PP2), (3) approximately 1,100ms after the…

Parent-targeted mobile phone intervention to increase physical activity in sedentary children: randomized pilot trial.

PubMed

Newton, Robert L; Marker, Arwen M; Allen, H Raymond; Machtmes, Ryan; Han, Hongmei; Johnson, William D; Schuna, John M; Broyles, Stephanie T; Tudor-Locke, Catrine; Church, Timothy S

2014-11-10

Low levels of moderate-to-vigorous physical activity are associated with adverse health consequences. The intent of the study was to determine the feasibility and efficacy of a 12-week physical activity promotion program targeting children, which was delivered to parents through mobile phones. Potential participants were recruited through advertisements placed in the newspaper, local hospitals and schools, and an email listserv. Sedentary children aged 6-10 years were randomly assigned to a minimal (MIG) or intensive (IIG) intervention group. Parents in the MIG were given a goal to increase (within 1 month) and maintain their child's activity at 6000 pedometer steps/day above their baseline levels and to monitor their child's steps daily. Parents in the IIG were given the same steps/day and monitoring goals, in addition to text messages and articles containing additional behavioral strategies (based on the Social Cognitive Theory) designed to promote their child's physical activity. The intervention components were delivered via mobile phone. Anthropometrics, body composition, and questionnaires were administered in a clinic. Children wore a New Lifestyles pedometer (NL-1000) each day throughout the intervention and parents were to monitor their child's step counts daily. Out of 59 children who screened for the study, a total of 27 children (mean age 8.7, SD 1.4 years; 56%, 15/27 female; 59%, 16/27 African American) were enrolled and completed the study. Overall, 97.90% (2220/2268; 98.20%, 1072/1092 for MIG; 97.60%, 1148/1176 for IIG) of expected step data were successfully entered by the parent or study coordinator. Parents in the MIG and IIG were sent approximately 7 and 13 text messages per week, respectively, averaged over the course of the study. IIG parents accessed an average of 6.1 (SD 4.4) articles over the course of the intervention and accessed a fewer number of articles in the last month compared to the first 2 months of the study (P=.002). Children in both the MIG and IIG significantly increased their physical activity, averaged over 12 weeks, by 1427.6 (SD 583.0; P=.02) and 2832.8 (SD 604.9; P<.001) steps/day above baseline, respectively. The between group difference was not statistically significant (P=.10; effect size=.40), nor was the group by time interaction (P=.57). Regardless of group assignment, children who significantly increased their physical activity reported greater increases in physical activity enjoyment (P=.003). The number of behavioral articles accessed by IIG parents was significantly correlated with change in children's steps/day (r=.575, P=.04). Changes in children's steps/day were unrelated to changes in their body composition, mood, and food intake. Parent-targeted mobile phone interventions are feasible, yet more intense interventions may be needed to support parents' efforts to increase their children's physical activity to levels that approximate national recommendations. Clinicaltrials.gov NCT01551108; http://clinicaltrials.gov/show/NCT01551108 (Archived by WebCite at http://www.webcitation.org/6TNEOzXNX).

Parent-Targeted Mobile Phone Intervention to Increase Physical Activity in Sedentary Children: Randomized Pilot Trial

PubMed Central

Marker, Arwen M; Allen, H Raymond; Machtmes, Ryan; Han, Hongmei; Johnson, William D; Schuna Jr, John M; Broyles, Stephanie T; Tudor-Locke, Catrine; Church, Timothy S

2014-01-01

Background Low levels of moderate-to-vigorous physical activity are associated with adverse health consequences. Objective The intent of the study was to determine the feasibility and efficacy of a 12-week physical activity promotion program targeting children, which was delivered to parents through mobile phones. Methods Potential participants were recruited through advertisements placed in the newspaper, local hospitals and schools, and an email listserv. Sedentary children aged 6-10 years were randomly assigned to a minimal (MIG) or intensive (IIG) intervention group. Parents in the MIG were given a goal to increase (within 1 month) and maintain their child’s activity at 6000 pedometer steps/day above their baseline levels and to monitor their child’s steps daily. Parents in the IIG were given the same steps/day and monitoring goals, in addition to text messages and articles containing additional behavioral strategies (based on the Social Cognitive Theory) designed to promote their child’s physical activity. The intervention components were delivered via mobile phone. Anthropometrics, body composition, and questionnaires were administered in a clinic. Children wore a New Lifestyles pedometer (NL-1000) each day throughout the intervention and parents were to monitor their child’s step counts daily. Results Out of 59 children who screened for the study, a total of 27 children (mean age 8.7, SD 1.4 years; 56%, 15/27 female; 59%, 16/27 African American) were enrolled and completed the study. Overall, 97.90% (2220/2268; 98.20%, 1072/1092 for MIG; 97.60%, 1148/1176 for IIG) of expected step data were successfully entered by the parent or study coordinator. Parents in the MIG and IIG were sent approximately 7 and 13 text messages per week, respectively, averaged over the course of the study. IIG parents accessed an average of 6.1 (SD 4.4) articles over the course of the intervention and accessed a fewer number of articles in the last month compared to the first 2 months of the study (P=.002). Children in both the MIG and IIG significantly increased their physical activity, averaged over 12 weeks, by 1427.6 (SD 583.0; P=.02) and 2832.8 (SD 604.9; P<.001) steps/day above baseline, respectively. The between group difference was not statistically significant (P=.10; effect size=.40), nor was the group by time interaction (P=.57). Regardless of group assignment, children who significantly increased their physical activity reported greater increases in physical activity enjoyment (P=.003). The number of behavioral articles accessed by IIG parents was significantly correlated with change in children’s steps/day (r=.575, P=.04). Changes in children’s steps/day were unrelated to changes in their body composition, mood, and food intake. Conclusions Parent-targeted mobile phone interventions are feasible, yet more intense interventions may be needed to support parents’ efforts to increase their children’s physical activity to levels that approximate national recommendations. Trial Registration Clinicaltrials.gov NCT01551108; http://clinicaltrials.gov/show/NCT01551108 (Archived by WebCite at http://www.webcitation.org/6TNEOzXNX). PMID:25386899

[Interaction of free fatty acids with mitochondria during uncoupling of oxidative phosphorylation].

PubMed

Samartsev, V N; Rybakova, S R; Dubinin, M V

2013-01-01

The activity of free saturated fatty acids (caprylic, capric, lauric, myristic, palmitic and stearic) as inducers and regulators of uncoupling of oxidative phosphorylation with participation of ADP/ATP antiporter, aspartate/glutamate antiporter and cyclosporin A-sensitive structure was investigated in experiments on rat liver mitochondria. It is established that at equal uncoupling activity of fatty acids the regulatory effect is minimal for caprylic acid and raised with increasing the hydrophobicity of fatty acids reaching the maximum value for stearic acid. There exists the linear dependence of the regulatory effect value of fatty acids on fatty acids content in the hydrophobic region of the inner membrane. The model that describes the interaction of fatty acids with the hydrophobic region of the mitochondrial inner membrane preserving functional activity of organelles is developed. It is established that if molecules of various fatty acids being in the hydrophobic region of the membrane are equally effective as uncoupling regulators, their specific uncoupling activity is different. Caprylic acid, a short-chain fatty acid, possesses the highest uncoupling activity. As the acyl chain length increases, the specific uncoupling activity of fatty acids reduces exponentially. Under these conditions components of the uncoupling activity sensitive to glutamate and carboxyatractylate and glutamate and insensitive to these reagents (but sensitive to cyclosporin A) change approximately equally.

Long-term and baseline recreational physical activity and risk of endometrial cancer: the California Teachers Study.

PubMed

Dieli-Conwright, C M; Ma, H; Lacey, J V; Henderson, K D; Neuhausen, S; Horn-Ross, P L; Deapen, D; Sullivan-Halley, J; Bernstein, L

2013-08-06

Physical activity may be associated with decreasing endometrial cancer risk; it remains unclear whether the association is modified by body size. Among 93 888 eligible California Teachers Study participants, 976 were diagnosed with incident endometrial cancer between 1995-1996 and 2007. Cox proportional hazards regression methods were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with long-term (high school through age 54 years) and baseline (3 years prior to joining the cohort) strenuous and moderate recreational physical activity, overall and by body size. Increased baseline strenuous recreational physical activity was associated with decreased endometrial cancer risk (Ptrend=0.006) with approximately 25% lower risk among women exercising >3 h per week per year than among those exercising <1/2 h per week per year (RR, 0.76; 95% CI, 0.63-0.92). This inverse association was observed among overweight/obese women (body mass index ≥25 kg m(-2); Ptrend=0.006), but not among thinner women (Ptrend=0.12). Baseline moderate activity was associated with lower risk among overweight/obese women. Increasing physical activity, particularly strenuous activity, may be a lifestyle change that overweight and obese women can implement to reduce their endometrial cancer risk.

Effects of cochlear ablation on choline acetyltransferase activity in the rat cochlear nucleus and superior olive.

PubMed

Jin, Yong-Ming; Godfrey, Donald A; Sun, Yizhe

2005-07-01

Using microdissection and quantitative microassay, choline acetyltransferase (ChAT) activity was mapped in the cochlear nucleus (CN) and in the source nuclei of the olivocochlear bundle, the lateral superior olive and ventral nucleus of the trapezoid body. In control rats, gradients of ChAT activity were found within the major subdivisions of the CN and in the lateral superior olive. These gradients correlated with the known tonotopic organizations, with higher activities corresponding to locations representing higher sound frequencies. No gradient was found in the ventral nucleus of the trapezoid body. In rats surviving 7 days or 1 or 2 months after cochlear ablation, ChAT activity was increased 1 month after ablation in the anteroventral CN by 30-50% in most parts of the lesion-side and by 40% in the contralateral ventromedial part. ChAT activity in the lesion-side posteroventral CN was increased by approximately 40-50% at all survival times. Little change was found in the dorsal CN. Decreases of ChAT activity were also found ipsilaterally in the lateral superior olive and bilaterally in the ventral nucleus of the trapezoid body. Our results suggest that cholinergic neurons are involved in plasticity within the CN and superior olive following cochlear lesions. Copyright 2005 Wiley-Liss, Inc.

The use of neural networks for approximation of nuclear data

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

Korovin, Yu. A.; Maksimushkina, A. V., E-mail: AVMaksimushkina@mephi.ru

2015-12-15

The article discusses the possibility of using neural networks for approximation or reconstruction of data such as the reaction cross sections. The quality of the approximation using fitting criteria is also evaluated. The activity of materials under irradiation is calculated from data obtained using neural networks.

Very High Energy Outburst of Markarian 501 in May 2009

NASA Technical Reports Server (NTRS)

Aliu, E.; Archambault, S.; Archer, A.; Arlen, T.; Aune, T.; Barnacka, A.; Behera, B.; Beilicke, M.; Benbow, W.; Berger, K.;

Enhanced Stellar Activity for Slow Antisolar Differential Rotation?

NASA Astrophysics Data System (ADS)

Brandenburg, Axel; Giampapa, Mark S.

2018-03-01

High-precision photometry of solar-like members of the open cluster M67 with Kepler/K2 data has recently revealed enhanced activity for stars with a large Rossby number, which is the ratio of rotation period to the convective turnover time. Contrary to the well established behavior for shorter rotation periods and smaller Rossby numbers, the chromospheric activity of the more slowly rotating stars of M67 was found to increase with increasing Rossby number. Such behavior has never been reported before, although it was theoretically predicted to emerge as a consequence of antisolar differential rotation (DR) for stars with Rossby numbers larger than that of the Sun, because in those models the absolute value of the DR was found to exceed that for solar-like DR. Using gyrochronological relations and an approximate age of 4 Gyr for the members of M67, we compare with computed rotation rates using just the B ‑ V color. The resulting rotation–activity relation is found to be compatible with that obtained by employing the measured rotation rate. This provides additional support for the unconventional enhancement of activity at comparatively low rotation rates and the possible presence of antisolar differential rotation.

Mice Lacking TR4 Nuclear Receptor Develop Mitochondrial Myopathy with Deficiency in Complex I

PubMed Central

Liu, Su; Lee, Yi-Fen; Chou, Samuel; Uno, Hideo; Li, Gonghui; Brookes, Paul; Massett, Michael P.; Wu, Qiao; Chen, Lu-Min

2011-01-01

The estimated incidence of mitochondrial diseases in humans is approximately 1:5000 to 1:10,000, whereas the molecular mechanisms for more than 50% of human mitochondrial disease cases still remain unclear. Here we report that mice lacking testicular nuclear receptor 4 (TR4−/−) suffered mitochondrial myopathy, and histological examination of TR4−/− soleus muscle revealed abnormal mitochondrial accumulation. In addition, increased serum lactate levels, decreased mitochondrial ATP production, and decreased electron transport chain complex I activity were found in TR4−/− mice. Restoration of TR4 into TR4−/− myoblasts rescued mitochondrial ATP generation capacity and complex I activity. Further real-time PCR quantification and promoter studies found TR4 could modulate complex I activity via transcriptionally regulating the complex I assembly factor NDUFAF1, and restoration of NDUFAF1 level in TR4−/− myoblasts increased mitochondrial ATP generation capacity and complex I activity. Together, these results suggest that TR4 plays vital roles in mitochondrial function, which may help us to better understand the pathogenesis of mitochondrial myopathy, and targeting TR4 via its ligands/activators may allow us to develop better therapeutic approaches. PMID:21622535

Fibrinogen catabolism within the procoagulant VX-2 tumor of rabbit lung in vivo: Effluxing fibrin(ogen) fragments contain antiangiogenic activity.

PubMed

Hatton, Mark W C; Southward, Suzanne M R; Legault, Kimberly J; Ross, Bonnie L; Clarke, Bryan J; Bajzar, Laszlo; Blajchman, Morris A; Singh, Gurmit; Richardson, Mary

2004-04-01

Many types of solid tumors are known to be procoagulant environments. This is partly because a hyperpermeable vascular system within the tumor allows plasma hemostatic factors to accumulate in relatively high concentrations in the stroma, and many solid-tumor cells express tissue factor or a procoagulant factor. These circumstances appear to exist in the VX-2 lung tumor of the New Zealand White (NZW) rabbit, and they sustain a measurable turnover of stromal deposits of fibrin(ogen). We have measured the turnover of fibrinogen within tumors of the VX-2 tumor-burdened rabbit and analysed the catabolic products of fibrin(ogen) and the status of fibrinolysis in tumor-derived interpleural effusate. Using intravenously injected (125)I-labeled rabbit fibrinogen as a marker, we found that fibrinogen (approximate blood concentration 1740 microg/mL) passed from blood to VX-2 tumor stroma, saturating the tumor at a concentration of approximately 348 microg fibrinogen/g in approximately 12 hours. We measured fibrin(ogen) fragments, at a concentration of approximately 292 microg/mL, in interpleural effusates that we recovered from 13% of the VX-2-burdened rabbits. Unreduced fibrin(ogen) fragments consisted of 4 major components with a relative molecular mass of approximately 250,000 (assumed to be fragment X; approximately 9% of total fragments from densitometry of immunoblots), 200,000 (d-dimer; 41%), 110,000 (fragment D; 49%), and 50,000 to 55,000 (fragment E; 1%-2%) kD. Total fibrin(ogen) fragments immunopurified from effusates exhibited an antiangiogenic effect when subjected to a chick embryo chorioallantoic membrane procedure. Interpleural effusates were devoid of plasmin activity or active plasminogen activator inhibitor-1 but contained plasmin complexes and active urokinase-like plasminogen activator (uPA), alpha(2)-antiplasmin, and thrombin-activatable fibrinolysis inhibitor. We speculate that VX-2 cells release uPA to activate fibrinolysis within the tumor stroma. Catabolic products of hemostasis (eg, fibrinolytic fragments, angiostatin) flux from the stroma into the interpleural space, thereby providing a net antiangiogenic property to the effusate and ultimately to the lymphatic and circulatory systems.

Differential effects of phosphotyrosine phosphatase expression on hormone-dependent and independent pp60c-src activity.

PubMed

Way, B A; Mooney, R A

1994-10-26

pp60c-src kinase activity can be increased by phosphotyrosine dephosphorylation or growth factor-dependent phosphorylation reactions. Expression of the transmembrane phosphotyrosine phosphatase (PTPase) CD45 has been shown to inhibit growth factor receptor signal transduction (Mooney, RA, Freund, GG, Way, BA and Bordwell, KL (1992) J Biol Chem 267, 23443-23446). Here it is shown that PTPase expression decreased platelet-derived growth factor (PDGF)-dependent activation of pp60c-src but failed to increase hormone independent (basal) pp60c-src activity. PDGF-dependent tyrosine phosphorylation of its receptor was reduced by approximately 60% in cells expressing the PTPase. In contrast, a change in phosphotyrosine content of pp60c-src was not detected in response to PDGF or in PTPase+ cells. PDGF increased the intrinsic tyrosine kinase activity of pp60c-src in both control and PTPase+ cells, but the effect was smaller in PTPase+ cells. In an in vitro assay, hormone-stimulated pp60c-src autophosphorylation from PTPase+ cells was decreased 64 +/- 22%, and substrate phosphorylation by pp60c-src was reduced 54 +/- 16% compared to controls. Hormone-independent pp60c-src kinase activity was unchanged by expression of the PTPase. pp60c-src was, however, an in vitro substrate for CD45, being dephosphorylated at both the regulatory (Tyr527) and kinase domain (Tyr416) residues. In addition, in vitro dephosphorylation by CD45 increased pp60c-src activity. These findings suggest that the PDGF receptor was an in vivo substrate of CD45 but pp60c-src was not. The lack of activation of pp60c-src in the presence of expressed PTPase may demonstrate the importance of compartmentalization and/or accessory proteins to PTPase-substrate interactions.

Effect of cannabidiol on human gingival fibroblast extracellular matrix metabolism: MMP production and activity, and production of fibronectin and transforming growth factor β.

PubMed

Rawal, S Y; Dabbous, M Kh; Tipton, D A

2012-06-01

Marijuana (Cannabis sativa) use may be associated with gingival enlargement, resembling that caused by phenytoin. Cannabidiol (CBD), a nonpsychotropic Cannabis derivative, is structurally similar to phenytoin. While there are many reports on effects of phenytoin on human gingival fibroblasts, there is no information on effects of Cannabis components on these cells. The objective of this study was to determine effects of CBD on human gingival fibroblast fibrogenic and matrix-degrading activities. Fibroblasts were incubated with CBD in serum-free medium for 1-6 d. The effect of CBD on cell viability was determined by measuring activity of a mitochondrial enzyme. The fibrogenic molecule transforming growth factor β and the extracellular matrix molecule fibronectin were measured by ELISA. Pro-MMP-1 and total MMP-2 were measured by ELISA. Activity of MMP-2 was determined via a colorimetric assay in which a detection enzyme is activated by active MMP-2. Data were analysed using ANOVA and Scheffe's F procedure for post hoc comparisons. Cannabidiol had little or no significant effect on cell viability. Low CBD concentrations increased transforming growth factor β production by as much as 40% (p < 0.001), while higher concentrations decreased it by as much as 40% (p < 0.0001). Cannabidiol increased fibronectin production by as much as approximately 100% (p < 0.001). Lower CBD concentrations increased MMP production, but the highest concentrations decreased production of both MMPs (p < 0.05) and decreased MMP-2 activity (p < 0.02). The data suggest that the CBD may promote fibrotic gingival enlargement by increasing gingival fibroblast production of transforming growth factor β and fibronectin, while decreasing MMP production and activity. © 2011 John Wiley & Sons A/S.

Caspase inhibitors increase the rate of recovery of neural stem/progenitor cells from post-mortem rat brains stored at room temperature.

PubMed

Hasegawa, Atsuko; Yamada, Chikako; Tani, Miho; Hirano, Shun-ichiro; Tokumoto, Yasuhito; Miyake, Jun

2009-06-01

To match the demand of regenerative medicine for nerve system, collection of stem cells from the post-mortem body is one of the most practical ways. In this study, the storage condition of the post-mortem body was examined. We prepared neural stem/progenitor cells (NSPCs) from post-mortem rat brains stored at different temperatures. When brains were stored at 4 degrees C, for one week, we were able to obtain neurospheres (a spheroid body containing NSPCs) by stimulation of cells with epidermal growth factor (EGF). Incremental increases in storage temperature decreased the rate of appearance of neurospheres. Within 48 h at 15 degrees C, 24 h at 25 degrees C, in both condition, we were able to recover NSPCs from post-mortem rat brains. At 15 degrees C, 90% of neurosphere-forming activity was lost within 24 h. However, even after 24 h at 25 degrees C, 2% neurosphere-forming activity remained. After 6 h of death, there was very little difference between the rates of NSPC recovery at 4 degrees C and 25 degrees C. Addition of caspase inhibitors to both the rat brain storage solution and the NSPC culture medium increased the rate of neurosphere-forming activity. In particular, an inhibitor of caspase-8 activity increased the NSPC recovery rate approximately three-fold, with no accompanying detrimental effects on neural differentiation in vitro.

Regulation of accumulation of ammonium-inducible glutamate dehydrogenase catalytic activity and antigen during the cell cycle of fully induced, synchronous Chlorella sorokiniana cells.

PubMed

Yeung, A T; Bascomb, N F; Turner, K J; Schmidt, R R

1981-05-01

By use of a rocket immunoelectrophoresis-activity stain procedure, it was shown that catalytic activity of an ammonium-inducible nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH) was accompanied by a coincident increase in enzyme antigen during the cell cycle of preinduced synchronous Chlorella sorokiniana cells growing in the continuous presence of ammonia. Between the fourth and fifth hours of the G-1 phase of the cell cycle, a three- to fourfold increase in linear accumulation of enzyme antigen was observed. Pulse-chase studies with [35S]sulfate, coupled with a specific indirect immunoadsorption procedure for enzyme antigen, showed that NADP-GDH antigen undergoes continuous degradation (i.e., a half-life of 88 to 110 min) during its linear pattern of accumulation during the cell cycle. The apparent half-life of the enzyme increased by approximately 23% of the 4.5-h positive rate change in antigen accumulation during the cell cycle. This increase in half-life is insufficient in itself to account for the large change in rate of NADP-GDH antigen accumulation. The data from immunoelectrophoresis, pulse-chase, and initial 35S incorporation rate experiments taken together support the inference that changes in the rate of NADP-GDH synthesis are primarily responsible for the accumulation patterns of NADP-GDH activity during the C. sorokiniana cell cycle.

Ionoregulatory changes in different populations of maturing sockeye salmon Oncorhynchus nerka during ocean and river migration.

PubMed

Shrimpton, J M; Patterson, D A; Richards, J G; Cooke, S J; Schulte, P M; Hinch, S G; Farrell, A P

2005-11-01

We present the first data on changes in ionoregulatory physiology of maturing, migratory adult sockeye salmon Oncorhynchus nerka. Fraser River sockeye were intercepted in the ocean as far away as the Queen Charlotte Islands (approximately 850 km from the Fraser River) and during freshwater migration to the spawning grounds; for some populations this was a distance of over 700 km. Sockeye migrating in seawater toward the mouth of the Fraser River and upriver to spawning grounds showed a decline in gill Na+,K+-ATPase activity. As a result, gill Na+,K+-ATPase activity of fish arriving at the spawning grounds was significantly lower than values obtained from fish captured before entry into freshwater. Plasma osmolality and chloride levels also showed significant decreases from seawater values during the freshwater migration to spawning areas. Movement from seawater to freshwater increased mRNA expression of a freshwater-specific Na+,K+-ATPase isoform (alpha1a) while having no effect on the seawater-specific isoform (alpha1b). In addition, gill Na+,K+-ATPase activity generally increased in active spawners compared with unspawned fish on the spawning grounds and this was associated with a marked increase in Na+,K+-ATPase alpha1b mRNA. Increases in gill Na+,K+-ATPase activities observed in spawners suggests that the fish may be attempting to compensate for the osmotic perturbation associated with the decline in plasma chloride concentration and osmolality.

Dose fractionation and single subject studies in PET

NASA Astrophysics Data System (ADS)

Balakrishnan, Karthikayan

Conventional positron emission tomography (PET) for cognitive brain studies typically relies on information collected from the distribution of decays following an injection of 15O-labeled water. The number of injections that can be administered to the subject are constrained by radiation dose to the subject and total length of the PET scan. The standard protocol involves 8--10 injections of H152O separated by approximately 5--7 half-lives of 15O. The number of activation conditions that can be realistically studied in a standard PET session is between 8 and 10. This work investigates the physiological response of a simulated subject to H152O injections that are administered in small doses (1--5 mCi) with short inter-injection intervals (40--180 seconds). A larger number of activation conditions are presented to the subject with a wider variation in the activation paradigm. Repeat conditions are studies. Signal averaging methods are feasible with this method of dose administration. Sinograms from scans with similar activation conditions are summed together before reconstruction. The signal in the primary activation region of the brain is shown to increase while suppressing the contribution of secondary activation regions in the brain. The contrast of the final image is similarly increased which leads to easier identification of the primary activation region. An automated H152O -production unit controlled by a PC running LabView software was developed to produce the dose required for the injection sequence by controlling the flow of H152O -vapor that diffuses across a semi-permeable membrane into saline. The unit is capable of producing H152O rapidly for both the standard and the proposed dose administration methods. The system also detects the bolus arrival time at the subject's lungs using a small external plastic detector. Activation sequence commences with the rise in radioactivity observed by the detector. The simulations indicate that inter-injection intervals should be approximately 90 seconds apart. Contrast in the resulting images are higher than the standard methods. Secondary activation regions that confound primary activations are absent in the low-dose method. The results also indicate that the automated H152O maker is capable of producing and injecting the dose in the required succession under appropriate computer control.

Impact of protein and carbohydrate supplementation on plasma volume expansion and thermoregulatory adaptation by aerobic training in older men.

PubMed

Okazaki, Kazunobu; Ichinose, Takashi; Mitono, Hiroyuki; Chen, Mian; Masuki, Shizue; Endoh, Hiroshi; Hayase, Hideki; Doi, Tatsuya; Nose, Hiroshi

2009-09-01

We examined whether protein-carbohydrate (CHO) supplementation immediately after exercise each day during aerobic training facilitated plasma volume (PV) expansion and thermoregulatory and cardiovascular adaptations in older men. Fourteen moderately active older men [68 +/- 5 (SD) yr] were divided into two groups so as to have no significant differences in anthropometric measures, PV, and peak oxygen consumption rate (Vo(2peak)). Each group was provided with a mixture of protein and CHO (3.2 kcal, 0.18 g protein/kg body wt, Pro-CHO, n = 7) or a non-protein and low-calorie placebo (0.5 kcal, 0 g protein/kg body wt, CNT, n = 7) immediately after cycling exercise (60-75% Vo(2peak), 60 min/day, 3 days/wk) each day for 8 wk at approximately 19 degrees C ambient temperature (T(a)) and approximately 43% relative humidity (RH). Before and after training, we measured PV, cardiac stroke volume (SV), and esophageal temperature (T(es)) during 20-min exercise at 60% of pretraining Vo(2peak) at 30 degrees C T(a) and 50% RH. Moreover, we determined the sensitivity of the chest sweat rate (DeltaSR/DeltaT(es)) and forearm vascular conductance (DeltaFVC/DeltaT(es)) in response to increased T(es) during exercise. After training, PV increased by approximately 6% in Pro-CHO (P < 0.001), with an approximately 10% increase in SV during exercise (P < 0.001), but not in CNT (P > 0.07). DeltaFVC/DeltaT(es) increased by 80% and DeltaSR/DeltaT(es) by 18% in Pro-CHO (both P < 0.01) but not in CNT (P > 0.07). Moreover, we found a significant interactive effect of group x training on PV, SV, and DeltaFVC/DeltaT(es) (all P < 0.02) but with no significant effect of group (P > 0.4), suggesting that the supplement enhanced these responses to aerobic training. Thus postexercise protein-CHO supplementation during training caused PV expansion and facilitated thermoregulatory and cardiovascular adaptations, possibly providing a new training regimen for older men.

Characterization of active-site residues of the NIa protease from tobacco vein mottling virus.

PubMed

Hwang, D C; Kim, D H; Lee, J S; Kang, B H; Han, J; Kim, W; Song, B D; Choi, K Y

2000-10-31

Nuclear inclusion a (NIa) protease of tobacco vein mottling virus is responsible for the processing of the viral polyprotein into functional proteins. In order to identify the active-site residues of the TVMV NIa protease, the putative active-site residues, His-46, Asp-81 and Cys-151, were mutated individually to generate H46R, H46A, D81E, D81N, C151S, and C151A, and their mutational effects on the proteolytic activities were examined. Proteolytic activity was completely abolished by the mutations of H46R, H46A, D81N, and C151A, suggesting that the three residues are crucial for catalysis. The mutation of D81E decreased kcat marginally by about 4.7-fold and increased Km by about 8-fold, suggesting that the aspartic acid at position 81 is important for substrate binding but can be substituted by glutamate without any significant decrease in catalysis. The replacement of Cys-151 by Ser to mimic the catalytic triad of chymotrypsin-like serine protease resulted in the drastic decrease in kcat by about 1,260-fold. This result might be due to the difference of the active-site geometry between the NIa protease and chymotrypsin. The protease exhibited a bell-shaped pH-dependent profile with a maximum activity approximately at pH 8.3 and with the abrupt changes at the respective pKa values of approximately 6.6 and 9.2, implying the involvement of a histidine residue in catalysis. Taken together, these results demonstrate that the three residues, His-46, Asp-81, and Cys-151, play a crucial role in catalysis of the TVMV NIa protease.

A novel low-temperature-active β-glucosidase from symbiotic Serratia sp. TN49 reveals four essential positions for substrate accommodation.

PubMed

Zhou, Junpei; Zhang, Rui; Shi, Pengjun; Huang, Huoqing; Meng, Kun; Yuan, Tiezheng; Yang, Peilong; Yao, Bin

2011-10-01

A 2,373-bp full-length gene (bglA49) encoding a 790-residue polypeptide (BglA49) with a calculated mass of 87.8 kDa was cloned from Serratia sp. TN49, a symbiotic bacterium isolated from the gut of longhorned beetle (Batocera horsfieldi) larvae. The deduced amino acid sequence of BglA49 showed the highest identities of 80.1% with a conceptually translated protein from Pantoea sp. At-9b (EEW02556), 38.3% with the identified glycoside hydrolase (GH) family 3 β-glucosidase from Clostridium stercorarium NCBI 11754 (CAB08072), and <15.0% with the low-temperature-active GH 3 β-glucosidases from Shewanella sp. G5 (ABL09836) and Paenibacillus sp. C7 (AAX35883). The recombinant enzyme (r-BglA49) was expressed in Escherichia coli and displayed the typical characteristics of low-temperature-active enzymes, such as low temperature optimum (showing apparent optimal activity at 35°C), activity at low temperatures (retaining approximately 60% of its maximum activity at 20°C and approximately 25% at 10°C). Compared with the thermophilic GH 3 β-glucosidase, r-BglA49 had fewer hydrogen bonds and salt bridges and less proline residues. These features might relate to the increased structure flexibility and higher catalytic activity at low temperatures of r-BglA49. The molecular docking study of four GH 3 β-glucosidases revealed five conserved positions contributing to substrate accommodation, among which four positions of r-BglA49 (R192, Y228, D260, and E449) were identified to be essential based on site-directed mutagenesis analysis.

NADH oxidase activity (NOX) and enlargement of HeLa cells oscillate with two different temperature-compensated period lengths of 22 and 24 minutes corresponding to different NOX forms

NASA Technical Reports Server (NTRS)

Wang, S.; Pogue, R.; Morre, D. M.; Morre, D. J.

2001-01-01

NOX proteins are cell surface-associated and growth-related hydroquinone (NADH) oxidases with protein disulfide-thiol interchange activity. A defining characteristic of NOX proteins is that the two enzymatic activities alternate to generate a regular period length of about 24 min. HeLa cells exhibit at least two forms of NOX. One is tumor-associated (tNOX) and is inhibited by putative quinone site inhibitors (e.g., capsaicin or the antitumor sulfonylurea, LY181984). Another is constitutive (CNOX) and refractory to inhibition. The periodic alternation of activities and drug sensitivity of the NADH oxidase activity observed with intact HeLa cells was retained in isolated plasma membranes and with the solubilized and partially purified enzyme. At least two activities were present. One had a period length of 24 min and the other had a period length of 22 min. The lengths of both the 22 and the 24 min periods were temperature compensated (approximately the same when measured at 17, 27 or 37 degrees C) whereas the rate of NADH oxidation approximately doubled with each 10 degrees C rise in temperature. The rate of increase in cell area of HeLa cells when measured by video-enhanced light microscopy also exhibited a complex period of oscillations reflective of both 22 and 24 min period lengths. The findings demonstrate the presence of a novel oscillating NOX activity at the surface of cancer cells with a period length of 22 min in addition to the constitutive NOX of non-cancer cells and tissues with a period length of 24 min.

Effects of gamma irradiation on physicochemical properties of Korean red ginseng powder

NASA Astrophysics Data System (ADS)

Byun, Myung-Woo; Yook, Hong-Sun; Kwon, Oh-Jin; Kang, Il-Jun

1997-04-01

Gamma irradiation was applied to Korean red ginseng powder to improve its quality. Major physicochemical properties (approximate composition, pH, acidity, browning pigment, hydrogen donating activity, fatty acids, minerals and saponin) were not significantly changed by gamma irradiation up to 10 kGy. The TBA value was increased depending on the increment of irradiation dose level. In free amino acids, threonine was increased while, serine and glutamic acid were decreased by gamma irradiation. In total amino acids, total contents were not significantly changed by gamma irradiation though tyrosine was slightly decreased P ⩽ 0.05. In free sugar, glucose, sucrose and maltose were significantly increased by 7.5 and 10 kGy gamma irradiation P ⩽ 0.05

Event-related wave activity in the EEG provides new marker of ADHD.

PubMed

Alexander, David M; Hermens, Daniel F; Keage, Hannah A D; Clark, C Richard; Williams, Leanne M; Kohn, Michael R; Clarke, Simon D; Lamb, Chris; Gordon, Evian

2008-01-01

This study examines the utility of new measures of event-related spatio-temporal waves in the EEG as a marker of ADHD, previously shown to be closely related to the P3 ERP in an adult sample. Wave activity in the EEG was assessed during both an auditory Oddball and a visual continuous performance task (CPT) for an ADHD group ranging in age from 6 to 18 years and comprising mostly Combined and Inattentive subtypes, and for an age and gender matched control group. The ADHD subjects had less wave activity at low frequencies ( approximately 1 Hz) during both tasks. For auditory Oddball targets, this effect was shown to be related to smaller P3 ERP amplitudes. During CPT, the approximately 1 Hz wave activity in the ADHD subjects was inversely related to clinical and behavioral measures of hyperactivity and impulsivity. CPT wave activity at approximately 1 Hz was seen to "normalise" following treatment with stimulant medication. The results identify a deficit in low frequency wave activity as a new marker for ADHD associated with levels of hyperactivity and impulsivity. The marker is evident across a range of tasks and may be specific to ADHD. While lower approximately 1 Hz activity partly accounts for reduced P3 ERPs in ADHD, the effect also arises for tasks that do not elicit a P3. Deficits in behavioral inhibition are hypothesized to arise from underlying dysregulation of cortical inhibition.

Approximate number word knowledge before the cardinal principle.

PubMed

Gunderson, Elizabeth A; Spaepen, Elizabet; Levine, Susan C

2015-02-01

Approximate number word knowledge-understanding the relation between the count words and the approximate magnitudes of sets-is a critical piece of knowledge that predicts later math achievement. However, researchers disagree about when children first show evidence of approximate number word knowledge-before, or only after, they have learned the cardinal principle. In two studies, children who had not yet learned the cardinal principle (subset-knowers) produced sets in response to number words (verbal comprehension task) and produced number words in response to set sizes (verbal production task). As evidence of approximate number word knowledge, we examined whether children's numerical responses increased with increasing numerosity of the stimulus. In Study 1, subset-knowers (ages 3.0-4.2 years) showed approximate number word knowledge above their knower-level on both tasks, but this effect did not extend to numbers above 4. In Study 2, we collected data from a broader age range of subset-knowers (ages 3.1-5.6 years). In this sample, children showed approximate number word knowledge on the verbal production task even when only examining set sizes above 4. Across studies, children's age predicted approximate number word knowledge (above 4) on the verbal production task when controlling for their knower-level, study (1 or 2), and parents' education, none of which predicted approximation ability. Thus, children can develop approximate knowledge of number words up to 10 before learning the cardinal principle. Furthermore, approximate number word knowledge increases with age and might not be closely related to the development of exact number word knowledge. Copyright © 2014 Elsevier Inc. All rights reserved.

[Clinical risk factors for progressive myopia].

PubMed

Schaeffel, F

2012-08-01

The average worldwide frequency of myopia is approximately 30 % and is traditionally subdivided into school myopia and pathological myopia. A further distinction is made between progressive myopia and stationary myopia. There is a high correlation between the frequency of myopia and urbanization and training. Risk factors for development of myopia are close-up work, lack of outdoor activity, biometrical variables of the eye and genetic risk factors. Development of myopia can be positively influenced by peripheral focusing, increased exposure to light and in the future possibly pharmacologically.

Hotline Complaint Regarding A Defense Contract Audit Agency Employee Conducting Private For-Profit Tax Business Activity on Government Time and Using Government Equipment

DTIC Science & Technology

2011-06-28

auditors that have private businesses from performing private business tasks on Government time while teleworking . • Contact the U.S. Department of the...profit businesses and telework to perform tasks associated with their private businesses on Government time. Although teleworking did not cause the... teleworking , it increases the vulnerability that an unethical employee will misuse Government time. DCAA employs approximately 4,000 auditors, which is more

Scale-Up: Improving Large Enrollment Physics Courses

NASA Astrophysics Data System (ADS)

Beichner, Robert

1999-11-01

The Student-Centered Activities for Large Enrollment University Physics (SCALE-UP) project is working to establish a learning environment that will promote increased conceptual understanding, improved problem-solving performance, and greater student satisfaction, while still maintaining class sizes of approximately 100. We are also addressing the new ABET engineering accreditation requirements for inquiry-based learning along with communication and team-oriented skills development. Results of studies of our latest classroom design, plans for future classroom space, and the current iteration of instructional materials will be discussed.

Observation of spatial and temporal variations in X-ray bright point emergence patterns. [at solar surface

NASA Technical Reports Server (NTRS)

Golub, L.; Krieger, A. S.; Vaiana, G. S.

1976-01-01

Observations of X-ray bright points (XBP) over a six-month interval in 1973 show significant variations in both the number density of XBP as a function of heliographic longitude and in the full-sun average number of XBP from one rotation to the next. The observed increases in XBP emergence are estimated to be equivalent to several large active regions emerging per day for several months. The number of XBP emerging at high latitudes varies in phase with the low-latitude variation and reaches a maximum approximately simultaneous with a major outbreak of active regions. The quantity of magnetic flux emerging in the form of XBP at high latitudes alone is estimated to be as large as the contribution from all active regions.

[Detection of viable metabolically active yeast cells using a colorimetric assay].

PubMed

Růzicka, F; Holá, V

2008-02-01

The increasing concern of yeasts able to form biofilm brings about the need for susceptibility testing of both planktonic and biofilm cells. Detection of viability or metabolic activity of yeast cells after exposure to antimicrobials plays a key role in the assessment of susceptibility testing results. Colorimetric assays based on the color change of the medium in the presence of metabolically active cells proved suitable for this purpose. In this study, the usability of a colorimetric assay with the resazurin redox indicator for monitoring the effect of yeast inoculum density on the reduction rate was tested. As correlation between the color change rate and inoculum density was observed, approximate quantification of viable cells was possible. The assay would be of relevance to antifungal susceptibility testing in both planktonic and biofilm yeasts.

Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event.

PubMed

Konhauser, Kurt O; Pecoits, Ernesto; Lalonde, Stefan V; Papineau, Dominic; Nisbet, Euan G; Barley, Mark E; Arndt, Nicholas T; Zahnle, Kevin; Kamber, Balz S

2009-04-09

It has been suggested that a decrease in atmospheric methane levels triggered the progressive rise of atmospheric oxygen, the so-called Great Oxidation Event, about 2.4 Gyr ago. Oxidative weathering of terrestrial sulphides, increased oceanic sulphate, and the ecological success of sulphate-reducing microorganisms over methanogens has been proposed as a possible cause for the methane collapse, but this explanation is difficult to reconcile with the rock record. Banded iron formations preserve a history of Precambrian oceanic elemental abundance and can provide insights into our understanding of early microbial life and its influence on the evolution of the Earth system. Here we report a decline in the molar nickel to iron ratio recorded in banded iron formations about 2.7 Gyr ago, which we attribute to a reduced flux of nickel to the oceans, a consequence of cooling upper-mantle temperatures and decreased eruption of nickel-rich ultramafic rocks at the time. We measured nickel partition coefficients between simulated Precambrian sea water and diverse iron hydroxides, and subsequently determined that dissolved nickel concentrations may have reached approximately 400 nM throughout much of the Archaean eon, but dropped below approximately 200 nM by 2.5 Gyr ago and to modern day values ( approximately 9 nM) by approximately 550 Myr ago. Nickel is a key metal cofactor in several enzymes of methanogens and we propose that its decline would have stifled their activity in the ancient oceans and disrupted the supply of biogenic methane. A decline in biogenic methane production therefore could have occurred before increasing environmental oxygenation and not necessarily be related to it. The enzymatic reliance of methanogens on a diminishing supply of volcanic nickel links mantle evolution to the redox state of the atmosphere.

Effects of perinatal asphyxia on cell proliferation and neuronal phenotype evaluated with organotypic hippocampal cultures.

PubMed

Morales, P; Reyes, P; Klawitter, V; Huaiquín, P; Bustamante, D; Fiedler, J; Herrera-Marschitz, M

2005-01-01

The present report summarizes studies combining an in vivo and in vitro approach, where asphyxia is induced in vivo at delivery time of Wistar rats, and the long term effects on hippocampus neurocircuitry are investigated in vitro with organotypic cultures plated at postnatal day seven. The cultures preserved hippocampus layering and regional subdivisions shown in vivo, and only few dying cells were observed when assayed with a viability test at day in vitro 27. When properly fixed, cultures from asphyxia-exposed animals showed a decreased amount of microtubule-associated protein-2 immunocytochemically positive cells (approximately 30%), as compared with that from controls. The decrease in microtubule-associated protein-2 immunocytochemistry was particularly prominent in Ammon's horn 1 and dentate gyrus regions (approximately 40%). 5-Bromo-2'deoxyuridine labeling revealed a two-fold increase in cellular proliferation in cultures from asphyxia-exposed, compared with that from control animals. Furthermore, confocal microscopy and quantification using the optical disector technique demonstrated that in cultures from asphyxia-exposed animals approximately 30% of 5-bromo-2'deoxyuridine-positive cells were also positive to microtubule-associated protein-2, a marker for neuronal phenotype. That proportion was approximately 20% in cultures from control animals. Glial fibrillary acidic protein-immunocytochemistry and Fast Red nuclear staining revealed that the core of the hippocampus culture was surrounded by a well-developed network of glial fibrillary acidic protein-positive cells and glial fibrillary acidic protein-processes providing an apparent protective shield around the hippocampus. That shield was less developed in cultures from asphyxia-exposed animals. The increased mitotic activity observed in this study suggests a compensatory mechanism for the long-term impairment induced by perinatal asphyxia, although it is not clear yet if that mechanism leads to neurogenesis, astrogliogenesis, or to further apoptosis.

Valsalva's maneuver revisited: a quantitative method yielding insights into human autonomic control

NASA Technical Reports Server (NTRS)

Smith, M. L.; Beightol, L. A.; Fritsch-Yelle, J. M.; Ellenbogen, K. A.; Porter, T. R.; Eckberg, D. L.

1996-01-01

Seventeen healthy supine subjects performed graded Valsalva maneuvers. In four subjects, transesophageal echographic aortic cross-sectional areas decreased during and increased after straining. During the first seconds of straining, when aortic cross-sectional area was declining and peripheral arterial pressure was rising, peroneal sympathetic muscle neurons were nearly silent. Then, as aortic cross-sectional area and peripheral pressure both declined, sympathetic muscle nerve activity increased, in proportion to the intensity of straining. Poststraining arterial pressure elevations were proportional to preceding increases of sympathetic activity. Sympathetic inhibition after straining persisted much longer than arterial and right atrial pressure elevations. Similarly, R-R intervals changed in parallel with peripheral arterial pressure, until approximately 45 s after the onset of straining, when R-R intervals were greater and arterial pressures were smaller than prestraining levels. Our conclusions are as follows: opposing changes of carotid and aortic baroreceptor inputs reduce sympathetic muscle and increase vagal cardiac motor neuronal firing; parallel changes of barorsensory inputs provoke reciprocal changes of sympathetic and direct changes of vagal firing; and pressure transients lasting only seconds reset arterial pressure-sympathetic and -vagal response relations.

Electroconvulsive shock increases preproenkephalin messenger RNA abundance in rat hypothalamus.

PubMed Central

Yoshikawa, K; Hong, J S; Sabol, S L

1985-01-01

Daily administration of electroconvulsive shock (ECS) to rats for 10 days increased the content of [Met5]enkephalin in the hypothalamus and the striatum by 64% and 45%, respectively. The effect of ECS on the relative abundance of mRNA coding for the enkephalin precursor preproenkephalin was investigated. Analysis by cell-free translation of polyadenylylated RNA and immunoprecipitation of preproenkephalin revealed ECS-elicited increases of 79% and 14% in preproenkephalin mRNA activity in the hypothalamus and striatum, respectively. ECS treatment did not affect the general translational activity of total polyadenylylated RNA from these brain regions. A 32P-labeled probe prepared from a rat preproenkephalin cDNA clone hybridized with an apparently single species of polyadenylylated RNA of approximately equal to 1450 nucleotides from both hypothalamus and striatum. Dot-blot hybridization of polyadenylylated RNA with the rat probe indicated that ECS elicits a 76% increase in the preproenkephalin mRNA abundance in the hypothalamus and no significant change in the striatum. These results suggest that ECS treatment leads to enhanced biosynthesis of the enkephalin precursor in hypothalamic neurons. Images PMID:2578669

Implications of the angiotensin converting enzyme gene insertion/deletion polymorphism in health and disease: a snapshot review

PubMed Central

Gard, Paul R

2010-01-01

This review considers the 250+ papers concerning the association of the angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism (rs1799752) and various disease conditions published in 2009. The deletion allele occurs in approximately 55% of the population and is associated with increased activity of the ACE enzyme. It might be predicted that the D allele, therefore, might be associated with pathologies involving increased activity of the renin-angiotensin system. The D allele was seen to be associated with an increased risk of hypertension, pre-eclampsia, heart failure, cerebral infarct, diabetic nephropathy, encephalopathy, asthma, severe hypoglycaemia in diabetes, gastric cancer (in Caucasians) and poor prognosis following kidney transplant. On the positive side, the D allele appears to offer protection against schizophrenia and chronic periodontitis and confers greater up-per-body strength in old age. The I allele, meanwhile, offers improved endurance/athletic performance and aerobic capacity as determined by lung function tests, although it does increase the risk of oral squamous cell carcinoma and obstructive sleep apnoea in hypertensives. PMID:21537387

Mutagenesis of a bacteriophage lytic enzyme PlyGBS significantly increases its antibacterial activity against group B streptococci.

PubMed

Cheng, Qi; Fischetti, Vincent A

2007-04-01

Group B streptococci (GBS) are the leading cause of neonatal meningitis and sepsis worldwide. Intrapartum antibiotic prophylaxis (IAP) is the current prevention strategy given to pregnant women with confirmed vaginal GBS colonization. Due to antibiotic resistance identified in GBS, we previously developed another strategy using a bacteriophage lytic enzyme, PlyGBS, to reduce vaginal GBS colonization. In this study, various DNA mutagenesis methods were explored to produce PlyGBS mutants with increased lytic activity against GBS. Several hyperactive mutants were identified that contain only the endopeptidase domain found in the N-terminal region of PlyGBS and represent only about one-third of the wild-type PlyGBS in length. Significantly, these mutants not only have 18-28-fold increases in specific activities compared to PlyGBS, but they also have a similar activity spectrum against several streptococcal species. One of the hyperactive mutants, PlyGBS90-1, reduced the GBS colonization from >5 logs of growth per mouse to <50 colony-forming units (cfu) 4 h post treatment ( approximately 4-log reduction) using a single dose in a mouse vaginal model. A reduction in GBS colonization before delivery should significantly reduce neonatal GBS infection providing a safe alternative to IAP.

Drought offset ecological restoration program-induced increase in vegetation activity in the Beijing-Tianjin Sand Source Region, China.

PubMed

Wu, Zhitao; Wu, Jianjun; He, Bin; Liu, Jinghui; Wang, Qianfeng; Zhang, Hong; Liu, Yong

2014-10-21

To improve the ecological conditions, the Chinese government adopted six large-scale ecological restoration programs including 'Three-North Shelterbelt Project', "Grain for Green Project" and "Beijing-Tianjin Sand Source Control Project". Meanwhile, these ecologically vulnerable areas have experienced frequent droughts. However, little attention has been paid to the impact of drought on the effectiveness of these programs. Taking Beijing-Tianjin Sand Source Region (BTSSR) as study area, we investigated the role of droughts and ecological restoration program on trends of vegetation activities and to address the question of a possible "drought signal" in assessing effectiveness of ecological restoration program. The results demonstrate the following: (1) Vegetation activity increased in the BTSSR during 2000-2010, with 58.44% of the study area showing an increased NDVI, of which 11.80% had a significant increase at 0.95 confidential level. The decreasing NDVI trends were mainly concentrated in a southwest-to-northeast strip in the study area. (2) Drought was the main driving force for a decreasing trend of vegetation activity in the southwest-to-northeast regions of the BTSSR at the regional and spatial scales. Summer droughts in 2007 and 2009 contributed to the decreasing trend in NDVI. The severe and extreme droughts in summer reduced the NDVI by approximately 13.06% and 23.55%, respectively. (3) The residual analysis result showed that human activities, particularly the ecological restoration programs, have a positive impact on vegetation change. Hence, the decreasing trends in the southwest-to-northeast regions of the BTSSR cannot be explained by the improper ecological restoration program and is partly explained by droughts, especially summer droughts. Therefore, drought offset the ecological restoration program-induced increase in vegetation activity in the BTSSR.

CAPN 7 promotes the migration and invasion of human endometrial stromal cell by regulating matrix metalloproteinase 2 activity.

PubMed

Liu, Hongyu; Jiang, Yue; Jin, Xiaoyan; Zhu, Lihua; Shen, Xiaoyue; Zhang, Qun; Wang, Bin; Wang, Junxia; Hu, Yali; Yan, Guijun; Sun, Haixiang

2013-07-15

Matrix metalloproteinase 2 (MMP-2) has been reported to be an important regulator of cell migration and invasion through degradation of the extracellular matrix (ECM) in many diseases, such as cancer and endometriosis. Here, we found calcium-activated neutral protease 7 (CAPN 7) expression was markedly upregulated in the eutopic endometrium and endometrial stromal cells of women diagnosed with endometriosis. Our studies were carried out to detect the effects of CAPN 7 on human endometrial stromal cell (hESC) migration and invasion. Western blotting and quantitative real-time PCR were used to detect the expression of CAPN 7 in endometriosis patients and normal fertile women. Scratch-wound-healing and invasion chamber assay were used to investigate the role of CAPN 7 in hESC migration and invasion. Western blotting, quantitative real-time PCR and zymography were carried out to detect the effect of CAPN 7 on the expressions and activity of MMP-2. CAPN 7 was markedly up-regulated in endometriosis, thereby promoting the migration and invasion of hESC. CAPN 7 overexpression led to increased expression of MMP-2 and tissue inhibitor of metalloproteinases 2 (TIMP-2); CAPN 7 knockdown reversed these changes. CAPN 7 increased MMP-2 activity by increasing the ratio of MMP-2 to TIMP-2. We also found that OA-Hy (an MMP-2 inhibitor) decreased the effects of CAPN 7 overexpression on hESC migration and invasion by approximately 50% and 55%, respectively. Additionally, a coimmunoprecipitation assay demonstrated that CAPN 7 interacted with activator protein 2α (AP-2α): an important transcription factor of MMP-2. CAPN 7 promotes hESC migration and invasion by increasing the activity of MMP-2 via an increased ratio of MMP-2 to TIMP-2.

Cyclic stretching force selectively up-regulates transforming growth factor-beta isoforms in cultured rat mesangial cells.

PubMed Central

Riser, B. L.; Cortes, P.; Heilig, C.; Grondin, J.; Ladson-Wofford, S.; Patterson, D.; Narins, R. G.

1996-01-01

Glomerular distention from increased intraglomerular pressure stretches mesangial cells (MCs). Stretching MCs in culture stimulates extracellular matrix accumulation, suggesting that this may be a mechanism for glomerular hypertension-associated glomerulosclerosis. We examined whether mechanical stretching serves as a stimulus for the synthesis and activation of the prosclerotic molecule transforming growth factor (TGF)-beta, thus providing a potential system for auto-induction of extracellular matrix. Rat MCs cultured on flexible-bottom plates were subjected to cyclic stretching for up to 3 days and then assayed for TGF-beta mRNA, secretion of TGF-beta, and localization of active TGF-beta by immunostaining. MCs contained mRNA for all three mammalian isoforms of TGF-beta. Cyclic stretching for 36 hours increased TGF-beta1 and TGF-beta3 mRNA levels approximately twofold, without altering the levels of TGF-beta2 mRNA. This was followed at 48 to 72 hours by the increased secretion of both latent and active TGF-beta1. Latent, but not active, TGF-beta3 secretion also increased whereas the levels of TGF-beta2 were unaffected by mechanical force. The stretching force in this system is unequally distributed over the culture membrane. Localization of active TGF-beta by immunostaining demonstrated that the quantity of cell-associated cytokine across the culture was directly proportional to the zonal amplitude of the stretching force. These results demonstrate that stretching force stimulates MCs to selectively release and activate TGF-beta1. This mechanical induction of TGF-beta1 may help explain the increased extracellular matrix associated with intraglomerular hypertension. Images Figure 1 Figure 3 PMID:8669477

Approximations first: a closer look at applications of the definite integral

NASA Astrophysics Data System (ADS)

Brandt, Keith

2017-01-01

I propose that students pay more attention to the approximations that lead to integral formulas when they study applications of the definite integral. The goal is to focus students on the underlying concepts and the definition of the definite integral - and to steer them away from memorizing formulas. To address this goal, I have written some computer-based activities that guide students through the nuts and bolts of the approximations that eventually lead to integral formulas. I describe the activities and suggest a few changes as to how we might approach this material.

Cholinergic stimulation of the pons depresses respiration in decerebrate cats.

PubMed

Kimura, H; Kubin, L; Davies, R O; Pack, A I

1990-12-01

The injection of carbachol into the pontine tegmentum of decerebrate cats evokes a postural motor atonia that has many of the characteristics of the atonia of natural rapid-eye-movement (REM) sleep (Morales et al. J. Neurophysiol. 57: 1118-1129, 1987). We have used the carbachol-injected decerebrate cat to study the changes in respiratory neuronal activity that accompany the atonia. The activities of representative respiratory motor nerves--phrenic, intercostal, and hypoglossal--and that of a motor branch of C4 were recorded in decerebrate, vagotomized, paralyzed, and artificially ventilated cats. After the microinjection of carbachol, there was a profound suppression of activity in all the nerves and a decrease in respiratory rate. This was a consistent stereotyped response in which the magnitude of the suppression of respiratory-related activity was phrenic (to approximately 65% of control) less than inspiratory intercostal (approximately 50%) less than hypoglossal (approximately 10%) less than expiratory intercostal (approximately 5%). The decrease in respiratory rate (to approximately 70% of control) was caused by a prolongation of both inspiratory and expiratory durations. Complete reversal of the carbachol effect was elicited by the microinjection of atropine into the same site as the carbachol injection. This allowed us to produce a second episode of atonia by the injection of carbachol into the contralateral pons. Thus we have demonstrated the existence of neural pathways originating in the cholinoceptive cells of the pons that have the potential to powerfully and differentially depress various respiratory motoneuronal pools and to reduce the respiratory rate. These pathways are likely to be activated along with the atonia of REM sleep.

Efficient Production of Active Polyhydroxyalkanoate Synthase in Escherichia coli by Coexpression of Molecular Chaperones

PubMed Central

Thomson, Nicholas M.; Saika, Azusa; Ushimaru, Kazunori; Sangiambut, Smith; Tsuge, Takeharu; Summers, David K.

2013-01-01

The type I polyhydroxyalkanoate synthase from Cupriavidus necator was heterologously expressed in Escherichia coli with simultaneous overexpression of chaperone proteins. Compared to expression of synthase alone (14.55 mg liter−1), coexpression with chaperones resulted in the production of larger total quantities of enzyme, including a larger proportion in the soluble fraction. The largest increase was seen when the GroEL/GroES system was coexpressed, resulting in approximately 6-fold-greater enzyme yields (82.37 mg liter−1) than in the absence of coexpressed chaperones. The specific activity of the purified enzyme was unaffected by coexpression with chaperones. Therefore, the increase in yield was attributed to an enhanced soluble fraction of synthase. Chaperones were also coexpressed with a polyhydroxyalkanoate production operon, resulting in the production of polymers with generally reduced molecular weights. This suggests a potential use for chaperones to control the physical properties of the polymer. PMID:23335776

Qigong exercise with concentration predicts increased health.

PubMed

Jouper, John; Hassmén, Peter; Johansson, Mattias

2006-01-01

Regular physical activity has many positive health effects. Despite this, approximately 50% of all adults are not exercising enough to enjoy better health and may, therefore, need an alternative to vigorous physical exercise. Qigong offers a gentle way to exercise the body. A questionnaire sample of 253 participants was collected and correlations with the variable health-now were analyzed. Results showed that health-now was positively correlated with number of completed qigong courses (p < 0.05), with level of concentration (p < 0.01), session-time (p < 0.01), and years of practice (p < 0.05). Among these variables, concentration predicts an increased feeling of health (R(2) = 0.092). Qigong exercise thereby seems to offer a viable alternative to other more vigorous physical activities when wellness is the primary goal. When interpreted using self-determination theory, qigong seems to satisfy needs related to autonomy, competence and relatedness, thereby, primarily attracting individuals who are intrinsically motivated.

Influence of preadsorbed oxygen on activated chemisorption of methane on Pd(110)

NASA Astrophysics Data System (ADS)

Valden, M.; Pere, J.; Xiang, N.; Pessa, M.

1996-07-01

Dissociative chemisorption of methane on clean and oxygen modified Pd(110) has been studied by using molecular beam surface scattering. The absolute dissociation probability of CH 4 ( Stot) is found to increase exponentially with the incident normal energy ( En) of CH 4 and with surface temperature ( TS) on clean Pd(110). The kinetic isotope effect is also found; namely, Stot of CD 4 is 4 to 5 times smaller than Stot of CH 4 throughout the entire range of En studied. These results are consistent with a direct dissociation mechanism. Measurements on preadsorbed oxygen on Pd(110) show that Stot of CH 4 decreases linearly, as oxygen coverage is increased from 0 to 0.4 ML in good agreement with the first-order Langmuir kinetics when approximately two active sites are blocked by one oxygen atom. No influence of the oxygen induced surface reconstructions on the dissociative adsorption kinetics of CH 4 is observed.

Neural mechanisms underlying auditory feedback control of speech

PubMed Central

Reilly, Kevin J.; Guenther, Frank H.

2013-01-01

The neural substrates underlying auditory feedback control of speech were investigated using a combination of functional magnetic resonance imaging (fMRI) and computational modeling. Neural responses were measured while subjects spoke monosyllabic words under two conditions: (i) normal auditory feedback of their speech, and (ii) auditory feedback in which the first formant frequency of their speech was unexpectedly shifted in real time. Acoustic measurements showed compensation to the shift within approximately 135 ms of onset. Neuroimaging revealed increased activity in bilateral superior temporal cortex during shifted feedback, indicative of neurons coding mismatches between expected and actual auditory signals, as well as right prefrontal and Rolandic cortical activity. Structural equation modeling revealed increased influence of bilateral auditory cortical areas on right frontal areas during shifted speech, indicating that projections from auditory error cells in posterior superior temporal cortex to motor correction cells in right frontal cortex mediate auditory feedback control of speech. PMID:18035557

Hydrolysis of an orally active platelet inhibitory prostanoid amide in the plasma of several species.

PubMed

Honohan, T; Fitzpatrick, F A; Booth, D G; McGrath, J P; Morton, D R; Nishizawa, E

1980-01-01

The prostanoid 3-oxa-4,5,6-trinor-3,7-inter-m-phenylene-PGE1-amide (OI-PGE1-amide) has a prolonged duration of oral platelet aggregation inhibitory activity when compared to the parent free acid (OI-PGE1) in the rat. When incubated in rat plasma at 1 microgram/ml for 30 seconds prior to addition of ADP, OI-PGE1-amide inhibits in vitro rat platelet aggregation approximately 50%. OI-PGE1 inhibits at 1 ng/ml. Inhibition of platelet aggregation by plasma incubated with OI-PGE1-amide (1 microgram/ml) increases with time and the rate of this increase differs with species. Incubation of OI-PGE1 in plasma does not result in an increase of platelet inhibitory activity with time. The increase of platelet inhibitory activity was assumed to indicate hydrolysis of OI-PGE1-amide to the more active OI-PGE1. A compound, different from OI-PGE1-amide, was isolated by an ion exchange/silica gel separation sequence from an incubation of OI-PGE1-amide in rat plasma. It had potent platelet aggregation inhibitory activity. This material was shown to be OI-PGE1 by thin-layer chromatography, gas chromatography and mass spectral analysis. Studies with [3H]-OI-PGE1-amide confirmed the formation of OI-PGE1 in plasma incubations. Amide hydrolytic activity was significantly different between species, the rank order being: rat greater than guine pig greater than monkey = human greater than dog. This relationship corresponded with that determined by measuring the increase in platelet inhibitory activity with time in plasma incubations of OI-PGE1-amide reported above. Present data indicate that (a) OI-PGE1-amide is hydrolyzed to the parent acid by plasma enzymes of several species and (b) hydrolytic activity of plasma varies widely between species.

Associations between active shooter incidents and gun ownership and storage among families with young children in the United States.

PubMed

Morrissey, Taryn W

2017-07-01

The presence of firearms and their unsafe storage in the home can increase risk of firearm-related death and injury, but public opinion suggests that firearm ownership is a protective factor against gun violence. This study examined the effects of a recent nearby active shooter incident on gun ownership and storage practices among families with young children. A series of regression models, with data from the nationally representative Early Childhood Longitudinal Study-Birth Cohort merged with the FBI's Active Shooter Incidents data collected in 2003-2006, were used to examine whether household gun ownership and storage practices differed in the months prior to and following an active shooter incident that occurred anywhere in the United States or within the same state. Approximately one-fifth of young children lived in households with one or more guns; of these children, only two-thirds lived in homes that stored all guns in locked cabinets. Results suggest that the experience of a recent active shooter incident was associated with an increased likelihood of storing all guns locked, with the magnitude dependent on the temporal and geographic proximity of the incident. The severity of the incident, defined as the number of fatalities, predicted an increase in storing guns locked. Findings suggest that public shootings change behaviors related to firearm storage among families with young children. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups.

PubMed

DiBona, G F; Sawin, L L

1999-02-01

To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being approximately 0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3-0.4 Hz with normalized transfer gain of 0.33 +/- 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3-0.4 Hz with normalized transfer gains of 0. 63 +/- 0.05 at 0.2 Hz and 0.53 +/- 0.04 to 0.36 +/- 0.02 at 0.3-0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3-0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

9-Methyl-beta-carboline has restorative effects in an animal model of Parkinson's disease.

PubMed

Wernicke, Catrin; Hellmann, Julian; Zieba, Barbara; Kuter, Katarzyna; Ossowska, Krystyna; Frenzel, Monika; Dencher, Norbert A; Rommelspacher, Hans

2010-01-01

In a previous study, a primary culture of midbrain cells was exposed to 9-methyl-beta-carboline for 48 h, which caused an increase in the number of tyrosine hydroxylase-positive cells. Quantitative RT-PCR revealed increased transcription of genes participating in the maturation of dopaminergic neurons. These in vitro findings prompted us to investigate the restorative actions of 9-methyl-beta-carboline in vivo. The compound was delivered for 14 days into the left cerebral ventricle of rats pretreated with the neurotoxin 1-methyl-4-phenyl-pyridinium ion (MPP+) for 28 days applying a dose which lowered dopamine by approximately 50%. Interestingly, 9-methyl-beta-carboline reversed the dopamine-lowering effect of the neurotoxin in the left striatum. Stereological counts of tyrosine hydroxylase-immunoreactive cells in the substantia nigra revealed that the neurotoxin caused a decrease in the number of those cells. However, when treated subsequently with 9-methyl-beta-carboline, the number reached normal values. In search of an explanation for the restorative activity, we analyzed the complexes that compose the respiratory chain in striatal mitochondria by 2-dimension gel electrophoresis followed by MALDI-TOF peptide mass fingerprinting.We found no changes in the overall composition of the complexes. However, the activity of complex I was increased by approximately 80% in mitochondria from rats treated with MPP+ and 9-methyl-beta-carboline compared to MPP+ and saline and to sham-operated rats, as determined by measurements of nicotinamide adenine dinucleotide dehydrogenase activity. Microarray technology and single RT-PCR revealed the induction of neurotrophins: brain-derived neurotrophic factor, conserved dopamine neurotrophic factor, cerebellin 1 precursor protein, and ciliary neurotrophic factor. Selected western blots yielded consistent results. The findings demonstrate restorative effects of 9-methyl-beta-carboline in an animal model of Parkinson's disease that improve the effectiveness of the respiratory chain and promote the transcription and expression of neurotrophin-related genes.

Environmental management in resource-rich Alberta, Canada: first world jurisdiction, Third World analogue?

PubMed

Timoney, K; Lee, P

2001-12-01

Economic growth is frequently touted as a cure for environmental ills, particularly for those in Third World countries. Here we examine that paradigm in a case study of Alberta, Canada, a wealthy, resource-rich province within a wealthy nation. Through provincial-scale datasets, we examine the increasing pressures of the forest, petroleum, and agricultural industries upon the ecosystems of Alberta within management, economic, and political contexts. We advance the thesis that economic activity leads to environmental degradation unless ecosystem-based management is integrated into economic decision making. Agricultural lands cover 31.7%, and forest management areas leased to industry cover 33.4% of Alberta; both continue to increase in extent. The rate of logging (focused on old-growth by government policy) continues a decades-long exponential rise. Current Alberta annual petroleum production is 52.5 million m3 crude oil and 117 billion m3 of gas. As of early 1999, there were approximately 199,025 oil and gas wells and a conservative total of approximately 1.5-1.8 million km of seismic lines in Alberta. Fire occurrence data indicate no downward trends in annual area burned by wildfire, which may be characterized as driven by climate and inherently variable. When logging and wildfire are combined, the annual allowable cut in Alberta is unsustainable, even when only timber supply is considered and the effects of expanding agriculture and oil and gas activities are ignored. Ecosystem degradation in Alberta is pervasive and contrasts prominently with a high standard of living. A wealth of ecological data exists that indicates current resource-based economic activities are non-sustainable and destructive of ecosystem health yet these data are not considered within the economic decision making process. Given the complex, compounded, and increasing ecosystem perturbations, a future of unpleasant ecological surprises is likely. We conclude with tentative predictions as to where current trends in Alberta may lead if decisions biased against ecosystems continue.

77 FR 60114 - Agency Information Collection Activities Under OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

... approximately 100 entities on a daily basis. The recordkeeping requirement of section 22.5 is expected to apply to approximately 100 entities on an approximately annual basis. Based on experience with analogous... required by section 22.2(g) is expected to require about 100 hours annually per entity, for a total burden...

Restoration of Full Shoulder Range of Motion After Application of the Fascial Distortion Model.

PubMed

Boucher, Joshua D; Figueroa, Jose

2018-05-01

Decreased active and passive range of motion (ROM) accompanied by pain in the shoulder is a common presentation for patients with frozen shoulder, and it can be difficult to restore normal function. Through the fascial distortion model, physicians can apply a manual technique to rapidly and effectively increase ROM and decrease pain. A 28-year-old man presented 18 months after sustaining a shoulder hyperextension injury. On active and passive ROM examination, he had approximately 90° of shoulder abduction and moderately reduced internal rotation associated with 8/10 pain. After 2 applications of the fascial distortion model, his shoulder restored to full abduction and internal rotation with no pain.

Post-elution concentration of (188)Re by an electrochemical method.

PubMed

Chakravarty, Rubel; Dash, Ashutosh; Pillai, M R A; Venkatesh, Meera

2010-12-01

High specific activity (188)Re required for nuclear medicine is mostly obtained from (188)W/(188)Re generators. As the parent radionuclide (188)W is of low specific activity (<185 GBq/g), a relatively large volume of 0.9% saline is required for the elution of (188)Re. Post-elution concentration is needed in order to increase the radioactive concentration of the eluted (188)Re. An electrochemical procedure to concentrate (188)Re suitable for the preparation of radiopharmaceuticals is developed. (188)Re eluted from an alumina generator could be concentrated approximately 100 fold, and it could be used to label DMSA and HEDP with >98% yield. Copyright 2010 Elsevier Ltd. All rights reserved.

Concurrent Supermassive Black Hole and Galazy Growth: Linking Environment and Nuclear Activity in Zeta Equals 2.23 H Alpha Emitters

NASA Technical Reports Server (NTRS)

Lehmer, B. D.; Lucy, A. B.; Alexander, D. M.; Best, P. N.; Geach, J. E.; Harrison, C. M.; Hornschemeier, A. E.; Matsuda, Y.; Mullaney, J. R.; Smail, Ian;

Effects of isobutyrate supplementation on ruminal microflora, rumen enzyme activities and methane emissions in Simmental steers.

PubMed

Wang, C; Liu, Q; Zhang, Y L; Pei, C X; Zhang, S L; Wang, Y X; Yang, W Z; Bai, Y S; Shi, Z G; Liu, X N

2015-02-01

The objective of this study was to evaluate the effects of isobutyrate supplementation on rumen microflora, enzyme activities and methane emissions in Simmental steers consuming a corn stover-based diet. Eight ruminally cannulated Simmental steers were used in a replicated 4 × 4 Latin square experiment. The treatments were control (without isobutyrate), low isobutyrate (LIB), moderate isobutyrate (MIB) and high isobutyrate (HIB) with 8.4, 16.8 and 25.2 g isobutyrate per steer per day respectively. Isobutyrate was hand-mixed into the concentrate portion. Diet consisted of 60% corn stover and 40% concentrate [dry matter (DM) basis]. Dry matter intake (averaged 9 kg/day) was restricted to a maximum of 90% of ad libitum intake. Population of total bacteria, cellulolytic bacteria and anaerobic fungi were linearly increased, whereas that of protozoa and total methanogens was linearly reduced with increasing isobutyrate supplementation. Real-time PCR quantification of population of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Fibrobacter succinogenes was linearly increased with increasing isobutyrate supplementation. Activities of carboxymethyl cellulase, xylanase and β-glucosidase were linearly increased, whereas that of protease was linearly reduced. Methane production was linearly decreased with increasing isobutyrate supplementation. Effective degradabilities of cellulose and hemicellulose of corn stover were linearly increased, whereas that of crude protein in diet was linearly decreased with increasing isobutyrate supplementation. The present results indicate that isobutyrate supplemented improved microflora, rumen enzyme activities and methane emissions in steers. It was suggested that the isobutyrate stimulated the digestive micro-organisms or enzymes in a dose-dependent manner. In the experimental conditions of this trial, the optimum isobutyrate dose was approximately 16.8 g isobutyrate per steer per day. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Functional Based Adaptive and Fuzzy Sliding Controller for Non-Autonomous Active Suspension System

NASA Astrophysics Data System (ADS)

Huang, Shiuh-Jer; Chen, Hung-Yi

In this paper, an adaptive sliding controller is developed for controlling a vehicle active suspension system. The functional approximation technique is employed to substitute the unknown non-autonomous functions of the suspension system and release the model-based requirement of sliding mode control algorithm. In order to improve the control performance and reduce the implementation problem, a fuzzy strategy with online learning ability is added to compensate the functional approximation error. The update laws of the functional approximation coefficients and the fuzzy tuning parameters are derived from the Lyapunov theorem to guarantee the system stability. The proposed controller is implemented on a quarter-car hydraulic actuating active suspension system test-rig. The experimental results show that the proposed controller suppresses the oscillation amplitude of the suspension system effectively.

Polygalacturonase from Rhizopus stolonifer, an Elicitor of Casbene Synthetase Activity in Castor Bean (Ricinus communis L.) Seedlings 1

PubMed Central

Lee, Sung-Chul; West, Charles A.

1981-01-01

Apparently homogeneous polygalacturonase-elicitor purified from the filtrates of Rhizopus stolonifer cultures stimulates germinating castor bean seedlings to produce greatly increased levels of casbene synthetase activity. The purification procedure involved gel-filtration chromatography on Sephadex G-25 and G-75 columns followed by cation-exchange chromatography on a Sephadex CM C-50 column. Homogeneity of the purified preparation was indicated by the results of cationic polyacrylamide disc gel electrophoresis and isoelectric focusing (pI = 8.0). The identity of the casbene elicitor activity and polygalacturonase were indicated by the coincidence of the two activities at all stages of purification, the coincidence of both activities with the single protein-staining band detected on a cationic polyacrylamide disc gel and an isoelectric focusing gel, and the identical behavior of both activities on an agarose gel affinity column. The purified polygalacturonase-elicitor is a glycoprotein with approximately 20% carbohydrate content and an estimated molecular weight of 32,000 by polyacrylamide disc gel electrophoresis. PMID:16661728

Public support in England for raising the price of cigarettes to fund tobacco control activities.

PubMed

Gardner, Benjamin; West, Robert

2010-08-01

Increasing the price of cigarettes reduces consumption, with a global price elasticity of approximately -0.4. In the UK where the cost of cigarettes is already relatively high, there is an issue surrounding public acceptance of further price rises ahead of the inflation rate. Previous research suggests that price increases may be supported where funds are dedicated to tobacco control. This study assessed public support in England for such a policy. A cross-sectional household survey was conducted in England between August 2008 and January 2009. A representative sample of 8736 respondents aged 16+, of whom 1900 (22%) were cigarette smokers at the time of the survey, was recruited. The primary outcome measure was support for a 20p (4%) price increase on a pack of cigarettes with proceeds going to fund tobacco control activities. 6216 participants (71%), including half (47%) of current cigarette smokers, indicated that they would support a 20p price increase if funds were dedicated to tobacco control activities. Levels of support among smokers were similar across the social gradient and gender. Younger smokers were more likely to support the increase. Smokers who smoked 0-10 cigarettes per day were more supportive of the increase than heavier smokers. There is broad public support for raising the cost of cigarettes with funds being used for tobacco control activities. The absence of a social gradient among smokers concurs with other research showing that more disadvantaged smokers are as engaged with tobacco control objectives as more affluent smokers.

Clean copy association of production diseases with motor activity-sensing devices and milk progesterone concentrations in dairy cows.

PubMed

Williams, J; Ntallaris, T; Routly, J E; Jones, D N; Cameron, J; Holman-Coates, A; Smith, R F; Humblot, P; Dobson, H

2018-05-31

We have previously established that the efficiency of identifying oestrus with activity-sensing devices can be compromised by common production diseases; the present study was undertaken to determine how these diseases may affect device readings. A total of 67 Holstein-Friesian cows, >20 days postpartum, were equipped with activity-sensing neck collars and pedometers, and simultaneous milk progesterone profiles were also monitored twice a week. The influences of common production stressors on maximum activity and progesterone values were analysed. Approximately 30% potential oestrus events (low progesterone value between two high values) remained unrecognised by both activity methods, and progesterone values in these animals were higher on the potential day of oestrus when both activity methods did not detect an event (0.043 ± 0.004 versus 0.029 ± 0.004 ng/mL; P = 0.03). Data from a subset of 45 cows (two events each) were subjected to mixed models and multiple regression modelling to investigate associations with production diseases. Cow motor activity was lower in lame cows. Maximum progesterone concentrations prior to oestrus increased as time postpartum and body condition score (BCS) increased. There were also fewer days of low progesterone prior to oestrus associated with increases in BCS and maximum progesterone concentrations prior to oestrus. In conclusion, lameness was associated with lower activity values, but this suppression was insufficient to account for lowered oestrus detection efficiency of either device. However, associations were identified between production diseases and progesterone profiles. Copyright © 2018. Published by Elsevier Inc.

ERK1/2 mediates glucose-regulated POMC gene expression in hypothalamic neurons.

PubMed

Zhang, Juan; Zhou, Yunting; Chen, Cheng; Yu, Feiyuan; Wang, Yun; Gu, Jiang; Ma, Lian; Ho, Guyu

2015-04-01

Hypothalamic glucose-sensing neurons regulate the expression of genes encoding feeding-related neuropetides POMC, AgRP, and NPY - the key components governing metabolic homeostasis. AMP-activated protein kinase (AMPK) is postulated to be the molecular mediator relaying glucose signals to regulate the expression of these neuropeptides. Whether other signaling mediator(s) plays a role is not clear. In this study, we investigated the role of ERK1/2 using primary hypothalamic neurons as the model system. The primary neurons were differentiated from hypothalamic progenitor cells. The differentiated neurons possessed the characteristic neuronal cell morphology and expressed neuronal post-mitotic markers as well as leptin-regulated orexigenic POMC and anorexigenic AgRP/NPY genes. Treatment of cells with glucose dose-dependently increased POMC and decreased AgRP/NPY expression with a concurrent suppression of AMPK phosphorylation. In addition, glucose treatment dose-dependently increased the ERK1/2 phosphorylation. Blockade of ERK1/2 activity with its specific inhibitor PD98059 partially (approximately 50%) abolished glucose-induced POMC expression, but had little effect on AgRP/NPY expression. Conversely, blockade of AMPK activity with its specific inhibitor produced a partial (approximately 50%) reversion of low-glucose-suppressed POMC expression, but almost completely blunted the low-glucose-induced AgRP/NPY expression. The results indicate that ERK1/2 mediated POMC but not AgRP/NPY expression. Confirming the in vitro findings, i.c.v. administration of PD98059 in rats similarly attenuated glucose-induced POMC expression in the hypothalamus, but again had little effect on AgRP/NPY expression. The results are indicative of a novel role of ERK1/2 in glucose-regulated POMC expression and offer new mechanistic insights into hypothalamic glucose sensing. © 2015 Society for Endocrinology.

Sonophoresis Using Ultrasound Contrast Agents: Dependence on Concentration.

PubMed

Park, Donghee; Song, Gillsoo; Jo, Yongjun; Won, Jongho; Son, Taeyoon; Cha, Ohrum; Kim, Jinho; Jung, Byungjo; Park, Hyunjin; Kim, Chul-Woo; Seo, Jongbum

2016-01-01

Sonophoresis can increase skin permeability to various drugs in transdermal drug delivery. Cavitation is recognized as the predominant mechanism of sonophoresis. Recently, a new logical approach to enhance the efficiency of transdermal drug delivery was tried. It is to utilize the engineered microbubble and its resonant frequency for increase of cavitation activity. Actively-induced cavitation with low-intensity ultrasound (less than ~1 MPa) causes disordering of the lipid bilayers and the formation of aqueous channels by stable cavitation which indicates a continuous oscillation of bubbles. Furthermore, the mutual interactions of microbubble determined by concentration of added bubble are also thought to be an important factor for activity of stable cavitation, even in different characteristics of drug. In the present study, we addressed the dependence of ultrasound contrast agent concentration using two types of drug on the efficiency of transdermal drug delivery. Two types of experiment were designed to quantitatively evaluate the efficiency of transdermal drug delivery according to ultrasound contrast agent concentration. First, an experiment of optical clearing using a tissue optical clearing agent was designed to assess the efficiency of sonophoresis with ultrasound contrast agents. Second, a Franz diffusion cell with ferulic acid was used to quantitatively determine the amount of drug delivered to the skin sample by sonophoresis with ultrasound contrast agents. The maximum enhancement ratio of sonophoresis with a concentration of 1:1,000 was approximately 3.1 times greater than that in the ultrasound group without ultrasound contrast agent and approximately 7.5 times greater than that in the control group. These results support our hypothesis that sonophoresis becomes more effective in transdermal drug delivery due to the presence of engineered bubbles, and that the efficiency of transdermal drug delivery using sonophoresis with microbubbles depends on the concentration of microbubbles in case stable cavitation is predominant.

An effort to 'leverage' the effect of participation in a mass event on physical activity.

PubMed

Lane, Aoife; Murphy, Niamh; Bauman, Adrian

2015-09-01

Despite the considerable interest in community-based physical activity (PA) interventions, there is a lack of clarity on which strategies are most effective and most likely to work in different contexts. The purpose of this study was to use existing community resources to promote PA in a population sample of insufficiently active women using a cluster RCT design. Participants (n = 402) were grouped into 32 geographical-based clusters, which were randomly allocated into 16 intervention (n = 193) and 16 control (n = 209) regions. The intervention was delivered in conjunction with regional units of the Irish Sports Council; participants received a pack containing tailored information about local PA options in their community, training plans, stage-matched behaviour change booklets and a pedometer. Control participants received health promotion leaflets. Evaluation was conducted using the RE-AIM framework to assess both effectiveness and generalizability. Repeated measures ANOVAs with adjustment for clustering revealed that both groups displayed an approximate 39 min increase in PA, but decreases in sitting were greater in the intervention group than the control group (32.9 versus 1.2 min). Recall of materials was high ranging between 85 and 97% for the various intervention components. Finally, those who received higher doses of the intervention (three or more components) reported an approximate 50 min increase in PA compared with 18 min among those who did not use any aspect of the intervention. While no clear intervention effect was evident, this research was successful in linking and implementing good research design with PA promoting networks. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The phase differences of the interdecadal variabilities of tropical cyclone activity in the peak and late seasons over the western North Pacific

NASA Astrophysics Data System (ADS)

Fan, Tingting; Xu, Shibin; Huang, Fei; Zhao, Jinping

2018-04-01

This study compares the interdecadal variations in tropical cyclone (TC) activities over the western North Pacific (WNP) basin during the peak season (July-September) and late season (October-December) of 1955-2014 and explores the possible physical mechanisms behind the variations. Both the peak- and late-season tropical storm (TS) days show distinct interdecadal variations, while the late-season TS days lead the peak-season TS days by approximately 4 years on an interdecadal time scale. The late-season TC activity is related to the east-west sea surface temperature (SST) gradient across the equatorial Pacific. The westerly winds induced by the SST gradient can reduce the vertical wind shear and increase the low-level vorticity, which favors TC genesis over the TC genesis region. The peak-season TC activity appears to relate to the SST gradient between the Indian Ocean and the Central Pacific. The westerly wind induced by the SST gradient can reduce the vertical wind shear and increase the mid-level relative humidity, thereby enhancing the TC activity. The full picture of the interdecadal variation in the WNP TC activity during the peak and late seasons revealed in this study provides a new perspective on the seasonal TC forecasts and future projections.

Expression, purification and immobilization of tannase from Staphylococcus lugdunensis MTCC 3614.

PubMed

Chaitanyakumar, Amballa; Anbalagan, M

2016-12-01

Enzymes find their applications in various industries, due to their error free conversion of substrate into product. Tannase is an enzyme used by various industries for degradation of tannin. Biochemical characterization of a specific enzyme from one organism to other is one of the ways to search for enzymes with better traits for industrial applications. Here, tannase encoding gene from Staphylococcus lugdunensis was cloned and suitability of the enzyme in various conditions was analysed to find its application in various industry. The recombinant protein was expressed with 6× His tag and purified using nickel affinity beads. The enzyme was purified up to homogeneity, with approximate molecular weight of 66 kDa. Purified tannase exhibited specific activity of about 716 U/mg. Optimum enzyme activity was found to be 40 °C at pH 7.0. Biochemical characterization revealed; metal ions such as Zn 2+ , Fe 2+ , Fe 3+ and Mn 2+ inhibited tannase activity, and SDS at lower concentration, increased tannase activity. Non polar organic solvents increased the tannase activity and polar solvents inhibited the tannase activity. Tannase immobilization studies show protection of the enzyme under wide range of pH and temperature. Also in this study we report a method for recovery and repeated use of the tannase.

Active learning in optics for girls

NASA Astrophysics Data System (ADS)

Ali, R.; Ashraf, I.

2017-08-01

Active learning in Optics (ALO) is a self-funded program under the umbrella of the Abdus Salam International Centre for Theoretical Physics (ICTP) and Quaid-i-Azam University (QAU) to bring physical sciences to traditionally underserved Girls high schools and colleges in Pakistan. There is a significant gender disparity in physical Sciences in Pakistan. In Department of Physics at QAU, approximately 10 to 20% of total students were used to be females from past many decades, but now this percentage is increasing. To keep it up at same pace, we started ALO in January 2016 as a way to provide girls an enriching science experiences, in a very friendly atmosphere. We have organized many one-day activities, to support and encourage girls' students of government high schools and colleges to pursue careers in sciences. In this presentation we will describe our experience and lesson learned in these activities.

Incident diagnoses of cancers and cancer-related deaths, active component, U.S. Armed Forces, 2000-2011.

PubMed

2012-06-01

In the United States, cancer is one of the five leading causes of death in all age groups among both men and women; overall, approximately one in four deaths is attributable to cancer. Compared to the general U.S. population, military members have been estimated to have lower incidence rates of several cancers including colorectal, lung, and cervical cancers and higher rates of prostate, breast, and thyroid cancer. Between 2000 and 2011 in active component members of the U.S. military, crude incidence rates of most cancer diagnoses have remained stable. 9,368 active component service members were diagnosed with one of the cancers of interest and no specific increasing or decreasing trends were observed. Cancer is an uncommon cause of death among service members on active duty and accounted for a total of 1,185 deaths during the 12-year surveillance period.

Oxidative stress-induced increase of intracellular zinc in astrocytes decreases their functional expression of P2X7 receptors and engulfing activity.

PubMed

Furuta, Takahiro; Mukai, Ayumi; Ohishi, Akihiro; Nishida, Kentaro; Nagasawa, Kazuki

2017-12-01

Neuron-glia communication mediated by neuro- and glio-transmitters such as ATP and zinc is crucial for the maintenance of brain homeostasis, and its dysregulation is found under pathological conditions. It is reported that under oxidative stress-loaded conditions, astrocytes exhibit increased intra- and extra-cellular labile zinc, the latter triggering microglial M1 activation, while the pathophysiological role of the former remains unrevealed. In this study, we examined whether the oxidative stress-induced increase of intracellular labile zinc is involved in the P2X7 receptor (P2X7R)-mediated regulation of astrocytic engulfing activity. The exposure of cultured astrocytes to sub-lethal oxidative stress through their treatment with 400 μM H 2 O 2 increased intracellular labile zinc, of which the concentration reached a peak level of approximately 2 μM at 2 h after the treatment. In astrocytes under sub-lethal oxidative stress, the uptake of YO-PRO-1 and latex beads as markers for P2X7R channel/pore activity and astrocytic engulfing activity, respectively, was decreased, and these decreased activities were accompanied by decreased expression of P2X7R at the plasma membrane via intracellular labile zinc-mediated translocation of it. With the oxidative stress, the expression level of full length P2X7R relative to that of its splice variants in astrocytes was decreased, leading to a decrease of the relative expression of the trimer consisting of full length P2X7R. Collectively, sub-lethal oxidative stress induces an astrocytic modal shift from the normal resting engulfing mode to the activated astrogliosis mode via an intracellular labile zinc-mediated decrease of the functional expression of P2X7R.

Automated segmentation of blood-flow regions in large thoracic arteries using 3D-cine PC-MRI measurements.

PubMed

van Pelt, Roy; Nguyen, Huy; ter Haar Romeny, Bart; Vilanova, Anna

2012-03-01

Quantitative analysis of vascular blood flow, acquired by phase-contrast MRI, requires accurate segmentation of the vessel lumen. In clinical practice, 2D-cine velocity-encoded slices are inspected, and the lumen is segmented manually. However, segmentation of time-resolved volumetric blood-flow measurements is a tedious and time-consuming task requiring automation. Automated segmentation of large thoracic arteries, based solely on the 3D-cine phase-contrast MRI (PC-MRI) blood-flow data, was done. An active surface model, which is fast and topologically stable, was used. The active surface model requires an initial surface, approximating the desired segmentation. A method to generate this surface was developed based on a voxel-wise temporal maximum of blood-flow velocities. The active surface model balances forces, based on the surface structure and image features derived from the blood-flow data. The segmentation results were validated using volunteer studies, including time-resolved 3D and 2D blood-flow data. The segmented surface was intersected with a velocity-encoded PC-MRI slice, resulting in a cross-sectional contour of the lumen. These cross-sections were compared to reference contours that were manually delineated on high-resolution 2D-cine slices. The automated approach closely approximates the manual blood-flow segmentations, with error distances on the order of the voxel size. The initial surface provides a close approximation of the desired luminal geometry. This improves the convergence time of the active surface and facilitates parametrization. An active surface approach for vessel lumen segmentation was developed, suitable for quantitative analysis of 3D-cine PC-MRI blood-flow data. As opposed to prior thresholding and level-set approaches, the active surface model is topologically stable. A method to generate an initial approximate surface was developed, and various features that influence the segmentation model were evaluated. The active surface segmentation results were shown to closely approximate manual segmentations.

A genetic dissection of the photophobic response of Paramecium tetraurelia.

PubMed

Hinrichsen, Robert; Peters, Christian

2013-05-01

Paramecium tetraurelia displayed two behavioral responses upon the initiation of a light stimulus at 7 x 10(4) lux. The cells exhibited a photophobic response in the form of behavioral avoiding reactions, followed by an increase in forward swimming velocity that was significantly higher than prior to the light stimulus activation. It was determined that an intensity of approximately 6.5 x 10(3) lux was required to initiate a moderate avoidance behavioral response. Following the avoiding response, a gradual increase in speed occurred as the intensity increased, indicating that increased swimming speeds are dependent on the light intensity. Two mutants, pawnA and Dancer, were utilized since they affect known Ca(2+)-currents of the cell. The use of pawnA cells, which lack voltage-dependent Ca(2+) channel activity, showed that the two responses to light could be genetically separated, in that the cells showed no avoiding reactions, but did increase their swimming speed. The Dancer cells, which display exaggerated Ca(2+) channel activity, exhibited similar initial avoiding responses as the wild type cells, however did not increase their swimming speed as the intensity of the light was increased. This phenotype as replicated in wildtype cells that had been placed in 25 μM 8-Br-cGMP. These data demonstrate that the photophobic light response of Paramecium tetraurelia can be genetically dissected as a means of elucidating the molecular mechanisms of the light response. Copyright © 2013 Elsevier GmbH. All rights reserved.

Compensatory increases in nuclear PGC1alpha protein are primarily associated with subsarcolemmal mitochondrial adaptations in ZDF rats.

PubMed

Holloway, Graham P; Gurd, Brendon J; Snook, Laelie A; Lally, Jamie; Bonen, Arend

2010-04-01

We examined in insulin-resistant muscle if, in contrast to long-standing dogma, mitochondrial fatty acid oxidation is increased and whether this is attributed to an increased nuclear content of peroxisome proliferator-activated receptor (PPAR) gamma coactivator (PGC) 1alpha and the adaptations of specific mitochondrial subpopulations. Skeletal muscles from male control and Zucker diabetic fatty (ZDF) rats were used to determine 1) intramuscular lipid distribution, 2) subsarcolemmal and intermyofibrillar mitochondrial morphology, 3) rates of palmitate oxidation in subsarcolemmal and intermyofibrillar mitochondria, and 4) the subcellular localization of PGC1alpha. Electotransfection of PGC1alpha cDNA into lean animals tested the notion that increased nuclear PGC1alpha preferentially targeted subsarcolemmal mitochondria. Transmission electron microscope analysis revealed that in ZDF animals the number (+50%), width (+69%), and density (+57%) of subsarcolemmal mitochondria were increased (P < 0.05). In contrast, intermyofibrillar mitochondria remained largely unchanged. Rates of palmitate oxidation were approximately 40% higher (P < 0.05) in ZDF subsarcolemmal and intermyofibrillar mitochondria, potentially as a result of the increased PPAR-targeted proteins, carnitine palmitoyltransferase-I, and fatty acid translocase (FAT)/CD36. PGC1alpha mRNA and total protein were not altered in ZDF animals; however, a greater (approximately 70%; P < 0.05) amount of PGC1alpha was located in nuclei. Overexpression of PGC1alpha only increased subsarcolemmal mitochondrial oxidation rates. In ZDF animals, intramuscular lipids accumulate in the intermyofibrillar region (increased size and number), and this is primarily associated with increased oxidative capacity in subsarcolemmal mitochondria (number, size, density, and oxidation rates). These changes may result from an increased nuclear content of PGC1alpha, as under basal conditions, overexpression of PGC1alpha appears to target subsarcolemmal mitochondria.

Geranyl acetate esterase controls and regulates the level of geraniol in lemongrass (Cymbopogon flexuosus Nees ex Steud.) mutant cv. GRL-1 leaves.

PubMed

Ganjewala, Deepak; Luthra, Rajesh

2009-01-01

Essential oil isolated from lemongrass (Cymbopogon flexuosus) mutant cv. GRL-1 leaves is mainly composed of geraniol (G) and geranyl acetate (GA). The proportion of G and GA markedly fluctuates during leaf development. The proportions of GA and G in the essential oil recorded at day 10 after leaf emergence were approximately 59% and approximately 33% respectively. However, the level of GA went down from approximately 59 to approximately 3% whereas the level of G rose from approximately 33 to approximately 91% during the leaf growth period from day 10 to day 50. However, the decline in the level of GA was most pronounced in the early (day 10 to day 30) stage of leaf growth. The trend of changes in the proportion of GA and G has clearly indicated the role of an esterase that must be involved in the conversion of GA to G during leaf development. We isolated an esterase from leaves of different ages that converts GA into G and has been given the name geranyl acetate esterase (GAE). The GAE activity markedly varied during the leaf development cycle; it was closely correlated with the monoterpene (GA and G) composition throughout leaf development. GAE appeared as several isoenzymes but only three (GAE-I, GAE-II, and GAE-III) of them had significant GA cleaving activity. The GAE isoenzymes pattern was greatly influenced by the leaf developmental stages and so their GA cleaving activities. Like the GAE activity, GAE isoenzyme patterns were also found to be consistent with the monoterpene (GA and G) composition. GAE had an optimum pH at 8.5 and temperature at 30 degrees C. Besides GAE, a compound with phosphatase activity capable of hydrolyzing geranyl diphosphate (GPP) to produce geraniol has also been isolated.

Light responses in rods of vitamin A-deprived Xenopus.

PubMed

Solessio, Eduardo; Umino, Yumiko; Cameron, David A; Loew, Ellis; Engbretson, Gustav A; Knox, Barry E; Barlow, Robert B

2009-09-01

Accumulation of free opsin by mutations in rhodopsin or insufficiencies in the visual cycle can lead to retinal degeneration. Free opsin activates phototransduction; however, the link between constitutive activation and retinal degeneration is unclear. In this study, the photoresponses of Xenopus rods rendered constitutively active by vitamin A deprivation were examined. Unlike their mammalian counterparts, Xenopus rods do not degenerate. Contrasting phototransduction in vitamin A-deprived Xenopus rods with phototransduction in constitutively active mammalian rods may provide new understanding of the mechanisms that lead to retinal degeneration. The photocurrents of Xenopus tadpole rods were measured with suction electrode recordings, and guanylate cyclase activity was measured with the IBMX (3-isobutyl-1-methylxanthine) jump technique. The amount of rhodopsin in rods was determined by microspectrophotometry. The vitamin A-deprived rod outer segments were 60% to 70% the length and diameter of the rods in age-matched animals. Approximately 90% of its opsin content was in the free or unbound form. Analogous to bleaching adaptation, the photoresponses were desensitized (10- to 20-fold) and faster. Unlike bleaching adaptation, the vitamin A-deprived rods maintained near normal saturating (dark) current densities by developing abnormally high rates of cGMP synthesis. Their rate of cGMP synthesis in the dark (15 seconds(-1)) was twofold greater than the maximum levels attainable by control rods ( approximately 7 seconds(-1)). Preserving circulating current density and response range appears to be an important goal for rod homeostasis. However, the compensatory changes associated with vitamin A deprivation in Xenopus rods come at the high metabolic cost of a 15-fold increase in basal ATP consumption.