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1

Effects of small-sided game and change-of-direction training on reactive agility and change-of-direction speed.  

PubMed

The purpose of this study was to determine the effects of training change-of-direction speed and small-sided games on performance in the Planned-AFL agility test and reactive agility. Twenty-five elite-standard U-18 Australian Rules football players were randomly allocated either to a change-of-direction group or a small-sided games group. Players participated in one or two 15-min sessions per week with 11 sessions conducted over a 7-week period during the season. Tests conducted immediately before and after the training period included the Planned-AFL agility test and a video-based reactive agility test specific to Australian Rules football. The reactive agility test variables were total time, decision time and movement response time. The small-sided games group improved total time (P = 0.008, effect size = 0.93), which was entirely attributable to a very large reduction in decision time (P < 0.001, effect size = 2.32). Small-sided games produced a trivial change in movement response time as well as in the Planned-AFL agility test (P > 0.05). The change-of-direction training produced small to trivial changes in all of the test variables (P > 0.05, effect size = 0-0.2). The results suggest that small-sided games improve agility performance by enhancing the speed of decision-making rather than movement speed. The change-of-direction training was not effective for developing either change-of-direction speed as measured by the Planned-AFL test or reactive agility. PMID:24016360

Young, Warren; Rogers, Nathan

2014-01-01

2

Effect of Stepwise Pressure Change on Porosity Evolution during Directional Solidification in Small Cylindrical Channels  

NASA Technical Reports Server (NTRS)

Controlled directional solidification experiments were performed in capillary channels, using nitrogen-saturated succinonitrile, to examine the effect of an in-situ stepwise processing pressure increase on an isolated pore evolution. Two experiments were performed using different processing pressure input profiles. The results indicate that a processing pressure increase has a transient effect on pore growth geometry characterized by an initial phase of decreasing pore diameter, followed by a recovery phase of increasing pore diameter. The experimental results also show that processing pressure can be used as a control parameter to either increase or terminate porosity formation. A theoretical model is introduced which indicates that the pore formation process is limited by the diffusion of solute-gas through the melt, and that the observed response toa pressure increase is attributed to the re-equilibration of solute concentration in the melt associated with the increased melt pressure.

Grugel, R.N.; Lee, C.P.; Cox, M.C.; Blandford, B.T.; Anilkumar, A.V.

2008-01-01

3

Ebolavirus Proteins Suppress the Effects of Small Interfering RNA by Direct Interaction with the Mammalian RNA Interference Pathway ?  

PubMed Central

Cellular RNA interference (RNAi) provides a natural response against viral infection, but some viruses have evolved mechanisms to antagonize this form of antiviral immunity. To determine whether Ebolavirus (EBOV) counters RNAi by encoding suppressors of RNA silencing (SRSs), we screened all EBOV proteins using an RNAi assay initiated by exogenously delivered small interfering RNAs (siRNAs) against either an EBOV or a reporter gene. In addition to viral protein 35 (VP35), we found that VP30 and VP40 independently act as SRSs. Here, we present the molecular mechanisms of VP30 and VP35. VP30 interacts with Dicer independently of siRNA and with one Dicer partner, TRBP, only in the presence of siRNA. VP35 directly interacts with Dicer partners TRBP and PACT in an siRNA-independent fashion and in the absence of effects on interferon (IFN). Taken together, our findings elucidate a new mechanism of RNAi suppression that extends beyond the role of SRSs in double-stranded RNA (dsRNA) binding and IFN antagonism. The presence of three suppressors highlights the relevance of host RNAi-dependent antiviral immunity in EBOV infection and illustrates the importance of RNAi in shaping the evolution of RNA viruses.

Fabozzi, Giulia; Nabel, Christopher S.; Dolan, Michael A.; Sullivan, Nancy J.

2011-01-01

4

Small Changes in pH Have Direct Effects on Marine Bacterial Community Composition: A Microcosm Approach  

PubMed Central

As the atmospheric CO2 concentration rises, more CO2 will dissolve in the oceans, leading to a reduction in pH. Effects of ocean acidification on bacterial communities have mainly been studied in biologically complex systems, in which indirect effects, mediated through food web interactions, come into play. These approaches come close to nature but suffer from low replication and neglect seasonality. To comprehensively investigate direct pH effects, we conducted highly-replicated laboratory acidification experiments with the natural bacterial community from Helgoland Roads (North Sea). Seasonal variability was accounted for by repeating the experiment four times (spring, summer, autumn, winter). Three dilution approaches were used to select for different ecological strategies, i.e. fast-growing or low-nutrient adapted bacteria. The pH levels investigated were in situ seawater pH (8.15–8.22), pH 7.82 and pH 7.67, representing the present-day situation and two acidification scenarios projected for the North Sea for the year 2100. In all seasons, both automated ribosomal intergenic spacer analysis and 16S ribosomal amplicon pyrosequencing revealed pH-dependent community shifts for two of the dilution approaches. Bacteria susceptible to changes in pH were different members of Gammaproteobacteria, Flavobacteriaceae, Rhodobacteraceae, Campylobacteraceae and further less abundant groups. Their specific response to reduced pH was often context-dependent. Bacterial abundance was not influenced by pH. Our findings suggest that already moderate changes in pH have the potential to cause compositional shifts, depending on the community assembly and environmental factors. By identifying pH-susceptible groups, this study provides insights for more directed, in-depth community analyses in large-scale and long-term experiments.

Krause, Evamaria; Wichels, Antje; Gimenez, Luis; Lunau, Mirko; Schilhabel, Markus B.; Gerdts, Gunnar

2012-01-01

5

The persistence of directivity in small earthquakes  

USGS Publications Warehouse

We derive a simple inversion of peak ground acceleration (PGA) or peak ground velocity (PGV) for rupture direction and rupture velocity and then test this inversion on the peak motions obtained from seven 3.5 ??? M ??? 4.1 earthquakes that occurred in two clusters in November 2002 and February 2003 near San Ramon, California. These clusters were located on two orthogonal strike-slip faults so that the events share the same approximate focal mechanism but not the same fault plane. Three earthquakes exhibit strong directivity, but the other four earthquakes exhibit relatively weak directivity. We use the residual PGAs and PGVs from the other six events to determine station corrections for each earthquake. The inferred rupture directions unambiguously identify the fault plane for the three earthquakes with strong directivity and for three of the four earthquakes with weak directivity. The events with strong directivity have fast rupture velocities (0.63????? v ??? 0.87??); the events with weak directivity either rupture more slowly (0.17????? v ???0.35??) or bilaterally. The simple unilateral inversion cannot distinguish between slow and bilateral ruptures: adding a bilateral rupture component degrades the fit of the rupture directions to the fault planes. By comparing PGAs from the events with strong and weak directivity, we show how an up-dip rupture in small events can distort the attenuation of peak ground motion with distance. When we compare the rupture directions of the earthquakes to the location of aftershocks in the two clusters, we find than almost all the aftershocks of the three earthquakes with strong directivity occur within 70?? of the direction of rupture.

Boatwright, J.

2007-01-01

6

75 FR 15756 - Small Business Innovation Research Program Policy Directive  

Federal Register 2010, 2011, 2012, 2013

...to the Small Business Innovation Research (SBIR) Program...Directive; Small Business Innovation Research Program To...Directors, Small Business Innovation Research (SBIR) Program...with the issuance and management of funding...

2010-03-30

7

Field Effect Transistors: Direct-Write Complementary Graphene Field Effect Transistors and Junctions via Near-Field Electrospinning (Small 10/2014).  

PubMed

A novel process to create a self-aligned and chemically doped graphene channel is presented by L. Lin and co-workers on page 1920. Near-field electrospinning, reengineered from conventional electrospinning, is utilized to pattern and chemically dope the graphene layer using functionalized polymers such as PEI and PEO. Arbitrary patterning is readily available to write channels on either flexible or dielectric substrates. Field effects of p- and n-type graphene channel transistors are fabricated and a complimentary inverter circuitry using electronic junctions is successfully demonstrated. This work may be the impetus for substantial and practical development in graphene-based electronics. PMID:24846550

Chang, Jiyoung; Liu, Yumeng; Heo, Kwang; Lee, Byung Yang; Lee, Seung-Wuk; Lin, Liwei

2014-05-01

8

Innovative biomechanics for directional hearing in small flies.  

PubMed

In humans and animals alike, the localization of sound constitutes a fundamental processing task of the auditory system. Directional hearing relies on acoustic cues such as the interaural amplitude and time differences and also, sometimes, the signal spectral composition. In small animals, such as insects, the auditory receptors are forcibly set close together, a design constraint imposing very short interaural distances. Due to the physics of sound propagation, the close proximity of the sound receivers results in vanishingly small amplitude and time cues. Yet, because of their directionality, small auditory systems embed original and innovative solutions that can be of inspirational value to some acute problems of technological miniaturization. Such ears are found in a parasitoid fly that acoustically locates its singing cricket host. Anatomically rather unconventional, the fly's auditory system is endowed with a directional sensitivity that is based on the mechanical coupling between its two hemilateral tympanal membranes. The functional principle permitting this directionality may be of particular relevance for technological applications necessitating sensors that are low cost, low weight, and low energy. Based on silicon-etching technology, early prototypes of sub-millimeter acoustic sensors provide evidence for directional mechanical responses. Further developments hold the promise of applications in hearing aid technology, vibration sensors, and miniature video-acoustic surveillance systems. PMID:11341582

Robert, D

2001-04-01

9

The Problems with Access to Compulsory Education in China and the Effects of the Policy of Direct Subsidies to Students: An Empirical Study Based on a Small Sample  

ERIC Educational Resources Information Center

After a brief review of the achievements and the problems in compulsory education enrollment in the thirty years since the reform and opening up, this study analyzes the current compulsory education enrollment and dropout rates in China's least-developed regions and the factors affecting school enrollment based on survey data from a small sample…

Yanqing, Ding

2012-01-01

10

Small RNA-Directed Epigenetic Natural Variation in Arabidopsis thaliana  

PubMed Central

Progress in epigenetics has revealed mechanisms that can heritably regulate gene function independent of genetic alterations. Nevertheless, little is known about the role of epigenetics in evolution. This is due in part to scant data on epigenetic variation among natural populations. In plants, small interfering RNA (siRNA) is involved in both the initiation and maintenance of gene silencing by directing DNA methylation and/or histone methylation. Here, we report that, in the model plant Arabidopsis thaliana, a cluster of ?24 nt siRNAs found at high levels in the ecotype Landsberg erecta (Ler) could direct DNA methylation and heterochromatinization at a hAT element adjacent to the promoter of FLOWERING LOCUS C (FLC), a major repressor of flowering, whereas the same hAT element in ecotype Columbia (Col) with almost identical DNA sequence, generates a set of low abundance siRNAs that do not direct these activities. We have called this hAT element MPF for Methylated region near Promoter of FLC, although de novo methylation triggered by an inverted repeat transgene at this region in Col does not alter its FLC expression. DNA methylation of the Ler allele MPF is dependent on genes in known silencing pathways, and such methylation is transmissible to Col by genetic crosses, although with varying degrees of penetrance. A genome-wide comparison of Ler and Col small RNAs identified at least 68 loci matched by a significant level of ?24 nt siRNAs present specifically in Ler but not Col, where nearly half of the loci are related to repeat or TE sequences. Methylation analysis revealed that 88% of the examined loci (37 out of 42) were specifically methylated in Ler but not Col, suggesting that small RNA can direct epigenetic differences between two closely related Arabidopsis ecotypes.

Zhai, Jixian; Liu, Jun; Liu, Bin; Li, Pingchuan; Meyers, Blake C.; Chen, Xuemei; Cao, Xiaofeng

2008-01-01

11

Directional Solidification and Convection in Small Diameter Crucibles  

NASA Technical Reports Server (NTRS)

Pb-2.2 wt% Sb alloy was directionally solidified in 1, 2, 3 and 7 mm diameter crucibles. Pb-Sb alloy presents a solutally unstable case. Under plane-front conditions, the resulting macrosegregation along the solidified length indicates that convection persists even in the 1 mm diameter crucible. Al-2 wt% Cu alloy was directionally solidified because this alloy was expected to be stable with respect to convection. Nevertheless, the resulting macrosegregation pattern and the microstructure in solidified examples indicated the presence of convection. Simulations performed for both alloys show that convection persists for crucibles as small as 0.6 mm of diameter. For the solutally stable alloy, Al-2 wt% Cu, the simulations indicate that the convection arises from a lateral temperature gradient.

Chen, J.; Sung, P. K.; Tewari, S. N.; Poirier, D. R.; DeGroh, H. C., III

2003-01-01

12

Direct comparison of small RNA and transcription factor signaling  

PubMed Central

Small RNAs (sRNAs) and proteins acting as transcription factors (TFs) are the principal components of gene networks. These two classes of signaling molecules have distinct mechanisms of action; sRNAs control mRNA translation, whereas TFs control mRNA transcription. Here, we directly compare the properties of sRNA and TF signaling using mathematical models and synthetic gene circuits in Escherichia coli. We show the abilities of sRNAs to act on existing target mRNAs (as opposed to TFs, which alter the production of future target mRNAs) and, without needing to be first translated, have surprisingly little impact on the dynamics. Instead, the dynamics are primarily determined by the clearance rates, steady-state concentrations and response curves of the sRNAs and TFs; these factors determine the time delay before a target gene’s expression can maximally respond to changes in sRNA and TF transcription. The findings are broadly applicable to the analysis of signaling in gene networks, and we demonstrate that they can be used to rationally reprogram the dynamics of synthetic circuits.

Hussein, Razika; Lim, Han N.

2012-01-01

13

Direct comparison of small RNA and transcription factor signaling.  

PubMed

Small RNAs (sRNAs) and proteins acting as transcription factors (TFs) are the principal components of gene networks. These two classes of signaling molecules have distinct mechanisms of action; sRNAs control mRNA translation, whereas TFs control mRNA transcription. Here, we directly compare the properties of sRNA and TF signaling using mathematical models and synthetic gene circuits in Escherichia coli. We show the abilities of sRNAs to act on existing target mRNAs (as opposed to TFs, which alter the production of future target mRNAs) and, without needing to be first translated, have surprisingly little impact on the dynamics. Instead, the dynamics are primarily determined by the clearance rates, steady-state concentrations and response curves of the sRNAs and TFs; these factors determine the time delay before a target gene's expression can maximally respond to changes in sRNA and TF transcription. The findings are broadly applicable to the analysis of signaling in gene networks, and we demonstrate that they can be used to rationally reprogram the dynamics of synthetic circuits. PMID:22618873

Hussein, Razika; Lim, Han N

2012-08-01

14

Direct-reversible binding of small molecules to G protein ?? subunits  

PubMed Central

Heterotrimeric guanine nucleotide-binding proteins (G proteins) composed of three subunits ?, ?, ? mediate activation of multiple intracellular signaling cascades initiated by G protein-coupled receptors (GPCRs). Previously our laboratory identified small molecules that bind to G?? and interfere with or enhance binding of select effectors with G??. To understand the molecular mechanisms of selectivity and assess binding of compounds to G??, we used biophysical and biochemical approaches to directly monitor small molecule binding to G??. Surface plasmon resonance (SPR) analysis indicated that multiple compounds bound directly to G?? with affinities in the high nanomolar to low micromolar range but with surprisingly slow on and off rate kinetics. While the koff was slow for most of the compounds in physiological buffers, they could be removed from G?? with mild chaotropic salts or mildly dissociating collision energy in a mass-spectrometer indicating that compound-G?? interactions were non-covalent. Finally, at concentrations used to observe maximal biological effects the stoichiometry of binding was 1:1. The results from this study show that small molecule modulation of G??-effector interactions is by specific direct non-covalent and reversible binding of small molecules to G??. This is highly relevant to development of G?? targeting as a therapeutic approach since reversible, direct binding is a prerequisite for drug development and important for specificity.

Seneviratne, AMPB; Burroughs, Michael; Giralt, Ernest; Smrcka, Alan V.

2011-01-01

15

Natural aerosol direct and indirect radiative effects  

NASA Astrophysics Data System (ADS)

Natural aerosol plays a significant role in the Earth's system due to its ability to alter the radiative balance of the Earth. Here we use a global aerosol microphysics model together with a radiative transfer model to estimate radiative effects for five natural aerosol sources in the present-day atmosphere: dimethyl sulfide (DMS), sea-salt, volcanoes, monoterpenes, and wildfires. We calculate large annual global mean aerosol direct and cloud albedo effects especially for DMS-derived sulfate (-0.23 Wm-2 and -0.76 Wm-2, respectively), volcanic sulfate (-0.21 Wm-2 and -0.61 Wm-2) and sea-salt (-0.44 Wm-2 and -0.04 Wm-2). The cloud albedo effect responds nonlinearly to changes in emission source strengths. The natural sources have both markedly different radiative efficiencies and indirect/direct radiative effect ratios. Aerosol sources that contribute a large number of small particles (DMS-derived and volcanic sulfate) are highly effective at influencing cloud albedo per unit of aerosol mass burden.

Rap, Alexandru; Scott, Catherine E.; Spracklen, Dominick V.; Bellouin, Nicolas; Forster, Piers M.; Carslaw, Kenneth S.; Schmidt, Anja; Mann, Graham

2013-06-01

16

A direct measurement technique for small geometry MOS transistor capacitances  

Microsoft Academic Search

Accurate representation of MOS transistor capacitances is important for accurate circuit simulation. Due to the difficulties of direct measurement with meters, MOS intrinsic capacitances have not been studied extensively. Although several \\

K. C.-K. Weng; P. Yang

1985-01-01

17

DYNAMICS OF A SMALL DIRECT CYCLE PEBBLE BED HTR  

Microsoft Academic Search

The Dutch market for combined generation of heat and power identifies a unit size of 40 MW thermal for the conceptual design of a nuclear cogeneration plant. The ACACIA system provides 14 MWe electricity combined with 17 t\\/h of high temperature steam (220 o C, 10 bar) with a pebble bed high temperature reactor directly coupled with a helium compressor

E. C. Verkerk; A. I. van Heek

18

Salt disposal effects found small  

NASA Astrophysics Data System (ADS)

Brine discharges into the Gulf of Mexico averaging more than 600,000 barrels per day for the past year have had ‘few significant effects‘ on the marine environment off the Texas coast, according to a preliminary analysis by scientists and engineers at the Texas A&M University. The brine, 8 times saltier than the surrounding seawater, is produced when salt from underground deposits on shore is dissolved and pumped into the Gulf as part of the Strategic Petroleum Reserve Program.Lead by Roy Hann, Jr., of the Texas Engineering Experiment Station, the team is analyzing discharge from Bryan Mound at Freeport, Tex., and from the West Hackberry site near Cameron, La. After a year of discharge off Freeport, the researchers found ‘no brine-caused differences in sediment temperatures and bottom-water dissolved-oxygen levels which accompany increased salinity,’ Hann said. In addition, overall compositions of fish and shrimp remained stable.

Richman, Barbara T.

19

Carry-Over Effects of Small Classes.  

ERIC Educational Resources Information Center

Researchers followed up on fourth graders from Project STAR, a reduced class size experiment. Using norm and criterion-referenced achievement tests and teacher ratings of student effort, initiative, and behavior, they found significant small class carry-over effects on every achievement measure and significant participation differences in small

Finn, Jeremy D.; And Others

1989-01-01

20

EFFECTS OF WATERSHED DISTURBANCE ON SMALL STREAMS  

EPA Science Inventory

This presentation presents the effects of watershed disturbance on small streams. The South Fork Broad River Watershed was studied to evaluate the use of landscape indicators to predict pollutant loading at small spatial scales and to develop indicators of pollutants. Also studie...

21

Direct oxide reduction demonstration, small-scale studies  

SciTech Connect

This project was initiated to provide process design information to the Plutonium Recovery Project (PRP). Although direct oxide reduction (DOR) has been operated in a production mode both at the Rocky Flats Plant (now operated by EG&G, Inc.) and Los Alamos National Laboratory, many aspects of the process are ill-defined. Because the PRP plans include significant DOR capability, a well-defined process should minimize capital cost and maximize productivity. Reduced radiation exposure may also be realized. A detailed, statistically valid investigation of the direct oxide reduction process was carried out utilizing 100 grams or less of plutonium dioxide per experiment. Conditions were established for obtaining 95% + yields. Conclusions drawn from the results of the experimental work were utilized to make recommendations for future large-scale investigative and confirmative work as well large-scale production demonstration work. 4 refs., 5 figs., 14 tabs.

Long, J.L.; Santi, D.J.; Fisher, D.C.; Humiston, T.J.

1991-12-09

22

Direct oxide reduction demonstration, small-scale studies  

SciTech Connect

This project was initiated to provide process design information to the Plutonium Recovery Project (PRP). Although direct oxide reduction (DOR) has been operated in a production mode both at the Rocky Flats Plant (now operated by EG G, Inc.) and Los Alamos National Laboratory, many aspects of the process are ill-defined. Because the PRP plans include significant DOR capability, a well-defined process should minimize capital cost and maximize productivity. Reduced radiation exposure may also be realized. A detailed, statistically valid investigation of the direct oxide reduction process was carried out utilizing 100 grams or less of plutonium dioxide per experiment. Conditions were established for obtaining 95% + yields. Conclusions drawn from the results of the experimental work were utilized to make recommendations for future large-scale investigative and confirmative work as well large-scale production demonstration work. 4 refs., 5 figs., 14 tabs.

Long, J.L.; Santi, D.J.; Fisher, D.C.; Humiston, T.J.

1991-12-09

23

Direct and selective small-molecule activation of proapoptotic BAX.  

PubMed

BCL-2 family proteins are key regulators of the apoptotic pathway. Antiapoptotic members sequester the BCL-2 homology 3 (BH3) death domains of proapoptotic members such as BAX to maintain cell survival. The antiapoptotic BH3-binding groove has been successfully targeted to reactivate apoptosis in cancer. We recently identified a geographically distinct BH3-binding groove that mediates direct BAX activation, suggesting a new strategy for inducing apoptosis by flipping BAX's 'on switch'. Here we applied computational screening to identify a BAX activator molecule that directly and selectively activates BAX. We demonstrate by NMR and biochemical analyses that the molecule engages the BAX trigger site and promotes the functional oligomerization of BAX. The molecule does not interact with the BH3-binding pocket of antiapoptotic proteins or proapoptotic BAK and induces cell death in a BAX-dependent fashion. To our knowledge, we report the first gain-of-function molecular modulator of a BCL-2 family protein and demonstrate a new paradigm for pharmacologic induction of apoptosis. PMID:22634637

Gavathiotis, Evripidis; Reyna, Denis E; Bellairs, Joseph A; Leshchiner, Elizaveta S; Walensky, Loren D

2012-07-01

24

Directional harmonics in Doppler effect  

NASA Astrophysics Data System (ADS)

A mathematical theory is presented which shows that a moving reflector of waves gives rise to harmonics of the Doppler shift in the input impedance of the transmission medium. The analysis can be used to explain new 'direction of motion' detection phenomena.

Lazarus, M. J.; Somekh, M. G.; Novak, S.; Pantoja, F. R.

1981-01-01

25

Collision recognition and direction changes for small scale fish robots by acceleration sensors  

NASA Astrophysics Data System (ADS)

Typical obstacles are walls, rocks, water plants and other nearby robots for a group of small scale fish robots and submersibles that have been constructed in our lab. Sonar sensors are not employed to make the robot structure simple enough. All of circuits, sensors and processor cards are contained in a box of 9 x 7 x 4 cm dimension except motors, fins and external covers. Therefore, image processing results are applied to avoid collisions. However, it is useful only when the obstacles are located far enough to give images processing time for detecting them. Otherwise, acceleration sensors are used to detect collision immediately after it happens. Two of 2-axes acceleration sensors are employed to measure the three components of collision angles, collision magnitudes, and the angles of robot propulsion. These data are integrated to calculate the amount of propulsion direction change. The angle of a collision incident upon an obstacle is the fundamental value to obtain a direction change needed to design a following path. But there is a significant amount of noise due to a caudal fin motor. Because caudal fin provides the main propulsion for a fish robot, there is a periodic swinging noise at the head of a robot. This noise provides a random acceleration effect on the measured acceleration data at the collision. We propose an algorithm which shows that the MEMS-type accelerometers are very effective to provide information for direction changes in spite of the intrinsic noise after the small scale fish robots have made obstacle collision.

Na, Seung Y.; Shin, Daejung; Kim, Jin Y.; Lee, Bae-Ho

2005-05-01

26

Testing the Effectiveness of Advance Medical Directives.  

National Technical Information Service (NTIS)

The purpose of the research is to examine three key psychological assumptions underlying the effective use of advance medical directives in end-of-life decision making. Instructional advance directives are widely advocated as a crucial means of improving ...

P. H. Ditto

2002-01-01

27

An algorithm based on spatial filter for infrared small target detection and its application to an all directional IRST system  

NASA Astrophysics Data System (ADS)

For the small targets detection in single frame infrared image, a spatial filter algorithm based on an adaptive smooth filter and the Robinson Guard spatial filter is proposed in the paper. The algorithm can detect the small targets in the undulant background effectively with little target information loss; it is implemented easily by digital processor ADSP-TS201S with high performance and successfully used in an all directional IRST system. The experiments show the effectiveness of the detection performance.

Luo, Jun-hui; Ji, Hong-bing; Liu, Jin

2007-01-01

28

Biological Effects of Directed Energy  

Microsoft Academic Search

This Final Report summarizes the biological effects research conducted by Veridian Engineering personnel under contract F41624-96-C-9009 in support of the Air Force Research Laboratory's Radio Frequency Radiation Branch from April 1997 to April 2002. Biological effects research and consultation were provided in five major areas: Active Denial System (also known as Vehicle Mounted Active Denial System), radio frequency radiation (RFR)

Thomas Dayton; Charles Beason; M. K. Hitt; Walter Rogers; Michael Cook

2002-01-01

29

Direct connections assist neurons to detect correlation in small amplitude noises  

PubMed Central

We address a question on the effect of common stochastic inputs on the correlation of the spike trains of two neurons when they are coupled through direct connections. We show that the change in the correlation of small amplitude stochastic inputs can be better detected when the neurons are connected by direct excitatory couplings. Depending on whether intrinsic firing rate of the neurons is identical or slightly different, symmetric or asymmetric connections can increase the sensitivity of the system to the input correlation by changing the mean slope of the correlation transfer function over a given range of input correlation. In either case, there is also an optimum value for synaptic strength which maximizes the sensitivity of the system to the changes in input correlation.

Bolhasani, E.; Azizi, Y.; Valizadeh, A.

2013-01-01

30

Combination of earthquake direction effects  

NASA Astrophysics Data System (ADS)

The correct application of the square root of the sum of the squares (SRSS) rule is presented for obtaining the combined responses of a subsystem to seismic excitations given by orthogonal earthquake components represented by system response spectra. Alternate methods of applying the SRSS, which are sometimes used either for simplicity or due to different interpretation, are evaluated and compared with the correct method. The evaluations consider the following four cases: (1) the correct method which combines the responses in a particular direction given by each earthquake component as a last step, (2) a generally unconservative method whereby both the system response spectra and the resulting subsystem responses are combind by the SRSS, (3) a method which can be unconservative for unequal earthquake components where the system response spectra are combined by the absolute sum and the resulting responses by the SRSS, and (4) a conservative method which combines the system response spectra by the SRSS but adds the resulting responses absolutely.

Morrone, A.

31

Direction, Inducement, and Schemes: Investment Strategies for Small-Scale Irrigation Systems.  

National Technical Information Service (NTIS)

Existing and potential investment strategies for small-scale irrigation development are sorted along a continuum based on directness of investment. Appropriate uses of four investment strategies are discussed: (1) revenue sharing; (2) agency funding to im...

J. E. Nickum

1986-01-01

32

Brightness of the Sun's small scale magnetic field: proximity effects  

NASA Astrophysics Data System (ADS)

The net effect of the small scale magnetic field on the Sun's (bolometric) brightness is studied with realistic 3D MHD simulations. The direct effect of brightening within the magnetic field itself is consistent with measurements in high-resolution observations. The high "photometric accuracy" of the simulations, however, reveal compensating brightness effects that are hard to detect observationally. The influence of magnetic concentrations on the surrounding nonmagnetic convective flows (a "proximity effect") reduces the brightness by an amount exceeding the brightening by the magnetic concentrations themselves. The net photospheric effect of the small scale field (?-0.34% at a mean flux density of 50 G) is thus negative. We conclude that the main contribution to the observed positive correlation between the magnetic field and total solar irradiance must be magnetic dissipation in layers around the temperature minimum and above (not included in the simulations). This agrees with existing inferences from observations.

Thaler, I.; Spruit, H. C.

2014-06-01

33

Direct Instruction News: Effective School Practices, 2003.  

ERIC Educational Resources Information Center

The mission of the Association for Direct Instruction is to promote the improvement of effective educational methods. This journal, "Direct Instruction News," is their publication. The Spring 2003 (Volume 3, Number 1) contains the following articles: "Implementing DI Successfully" (Sara G. Tarver); "Textbooks: What?" (Bob Dixon); "Introduction to…

Tarver, Sara G., Ed.

2003-01-01

34

Direct Instruction News: Effective School Practices, 2002.  

ERIC Educational Resources Information Center

The mission of the Association for Direct Instruction is to promote the improvement of effective educational methods. This journal, "Direct Instruction News," is their publication. The Spring 2002 issue (Volume 2, Number 1) contains the following articles: "Same? Different? Both Same and Different" (Sara G. Tarver); "Cookie Cutter Curricula" (Bob…

Tarver, Sara G., Ed.

2002-01-01

35

Claw-pole machine design and tests for small scale direct driven applications  

Microsoft Academic Search

The direct driven generators in wind energy conversion systems avoid the noise, the vibration and potential risk caused by the gear box resistance. The permanent magnet claw-pole generator, due to its large number of poles, simple and reliable construction, is a competitive variant for a direct driven generator in a wind mill at small and medium power. Such a sample

Florin Jurca; Claudia Martis; Claudiu Oprea; Daniel Fodorean

2011-01-01

36

Ising model on directed small-world Voronoi Delaunay random lattices  

NASA Astrophysics Data System (ADS)

We investigate the critical properties of the Ising model in two dimensions on directed small-world lattice with quenched connectivity disorder. The disordered system is simulated by applying the Monte Carlo update heat bath algorithm. We calculate the critical temperature, as well as the critical exponents ?/ ?, ?/ ?, and 1/ ? for several values of the rewiring probability p . We find that this disorder system does not belong to the same universality class as the regular two-dimensional ferromagnetic model. The Ising model on directed small-world lattices presents in fact a second-order phase transition with new critical exponents which do not depend on p (0 < p < 1), but are identical to the exponents of the Ising model and the spin-1 Blume-Capel model on directed small-world network.

Sousa, Ediones M.; Lima, F. W. S.

2013-12-01

37

Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines  

Microsoft Academic Search

In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic

Allan Chertok; David Hablanian; Paul McTaggart; DOE Project Officer

2004-01-01

38

Foreign direct investment by small and medium sized enterprises: The theoretical background  

Microsoft Academic Search

This paper is an attempt to give a theoretical background to research on foreign direct investment by small and medium sized enterprises. Section 2 examines alternative theoretical approaches to SMEs investing abroad. Section 3 outlines the special issues which arise from SME foreign ventures and ends with an attempted synthesis of the theoretical approaches. In Section 4, a brief discussion

Peter J. Buckley

1989-01-01

39

A Small Modular Laboratory Hall Effect Thruster  

NASA Astrophysics Data System (ADS)

Electric propulsion technologies promise to revolutionize access to space, opening the door for mission concepts unfeasible by traditional propulsion methods alone. The Hall effect thruster is a relatively high thrust, moderate specific impulse electric propulsion device that belongs to the class of electrostatic thrusters. Hall effect thrusters benefit from an extensive flight history, and offer significant performance and cost advantages when compared to other forms of electric propulsion. Ongoing research on these devices includes the investigation of mechanisms that tend to decrease overall thruster efficiency, as well as the development of new techniques to extend operational lifetimes. This thesis is primarily concerned with the design and construction of a Small Modular Laboratory Hall Effect Thruster (SMLHET), and its operation on argon propellant gas. Particular attention was addressed at low-cost, modular design principles, that would facilitate simple replacement and modification of key thruster parts such as the magnetic circuit and discharge channel. This capability is intended to facilitate future studies of device physics such as anomalous electron transport and magnetic shielding of the channel walls, that have an impact on thruster performance and life. Preliminary results demonstrate SMLHET running on argon in a manner characteristic of Hall effect thrusters, additionally a power balance method was utilized to estimate thruster performance. It is expected that future thruster studies utilizing heavier though more expensive gases like xenon or krypton, will observe increased efficiency and stability.

Lee, Ty Davis

40

Direct detection of the asteroidal YORP effect.  

PubMed

The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the spin states of small bodies in the solar system. However, evidence for the effect has so far been indirect. We report precise optical photometric observations of a small near-Earth asteroid, (54509) 2000 PH5, acquired over 4 years. We found that the asteroid has been continuously increasing its rotation rate omega over this period by domega/dt = 2.0 (+/-0.2) x 10(-4) degrees per day squared. We simulated the asteroid's close Earth approaches from 2001 to 2005, showing that gravitational torques cannot explain the observed spin rate increase. Dynamical simulations suggest that 2000 PH5 may reach a rotation period of approximately 20 seconds toward the end of its expected lifetime. PMID:17347414

Lowry, Stephen C; Fitzsimmons, Alan; Pravec, Petr; Vokrouhlicky, David; Boehnhardt, Hermann; Taylor, Patrick A; Margot, Jean-Luc; Galád, Adrian; Irwin, Mike; Irwin, Jonathan; Kusnirák, Peter

2007-04-13

41

Small world effects in networks: an engineering interpretation  

Microsoft Academic Search

In this paper, an engineering interpretation of small world effects in networks is given. After briefly summarizing the main features of small world networks, an attempt is made to investigate the relevance that small world effects can have in communication networks. The aim is that of investigating the relationship between small world behaviour and some of the characteristic parameters associated

Sabato Manfredi; Mario Di Bernardo; Franco Garofalo

2004-01-01

42

The Butterfly Effect of Small Open Economies  

Microsoft Academic Search

The rational expectations equilibrium of a small open economy can be subject to indeterminacy if foreign monetary policy does not satisfy the Taylor principle. We study the implications of foreign-induced indeterminacy for the conduct of monetary policy in a small open economy. In the canonical sticky-price small open economy model, we find that indeterminacy arising in the large economy can

Jarkko Jääskelä; Mariano Kulish

2007-01-01

43

The butterfly effect of small open economies  

Microsoft Academic Search

The rational expectations equilibrium of a small open economy can be subject to indeterminacy if foreign monetary policy does not satisfy the Taylor principle. We study the implications of foreign induced indeterminacy in the two-country version of the sticky-price small open economy model. Our main finding is that ‘smallness’ is a property of the unique rational expectations equilibrium of the

Jarkko P. Jääskelä; Mariano Kulish

2010-01-01

44

Halo Effect on Direct Neutron Capture Process  

Microsoft Academic Search

We calculate the capture cross sections of the 10Be(n,gamma) 11Be reaction by means of the asymptotic normalization coefficient method and demonstrate the halo effects on the capture cross sections for the direct radiative neutron capture where a p-, s- or d-wave neutron is captured into an s-orbit or p-orbit in 11Be by emitting an E1 gamma-ray, respectively. The result shows

Zu-Hua Liu; Hong-Yu Zhou

2004-01-01

45

The Enduring Effects of Small Classes.  

ERIC Educational Resources Information Center

Used Tennessee Project STAR data to examine the impact of the duration of participation in small classes on K-3 students' later school performance. Year in which students started and number of years they participated in small classes were important mediators of benefits gained. Starting early and continuing for at least 3 years were necessary to…

Finn, Jeremy D.; Gerber, Susan B.; Achilles, Charles M.; Boyd-Zaharias, Jayne

2001-01-01

46

Rotational effect in two-dimensional cooperative directed transport  

NASA Astrophysics Data System (ADS)

In this review we investigate the rotation effect in the motion of coupled dimer in a two-dimensional asymmetric periodic potential. Free rotation does not generate directed transport in translational direction, while we find it plays an critical role in the motors motility when the dimer moves under the effect of asymmetry ratchet potential. In the presence of external force, we study the relation between the average current and the force numerically and theoretically. The numerical results show that only appropriate driving force could produce nonzero current and there are current transitions when the force is large enough. An analysis of stability analysis of limit cycles is applied to explain the occurrence of these transitions. Moreover, we numerically simulate the transport of this coupled dimer driven by the random fluctuations in the rotational direction. The existence of noise smooths the current transitions induced by the driving force and the resonance-like peaks which depend on the rod length emerge in small noise strength. Thanks to the noise in the rotational direction, autonomous motion emerges without the external force and large noise could make the current reversal happen. Eventually, the new mechanism to generate directed transport by the rotation is studied.

Qiao, Li-Yan; Li, Yun-yun; Zheng, Zhi-Gang

2014-05-01

47

Direct measurement of the Chudakov effect.  

PubMed

Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing a CCD detector are presented. It is shown that pairs--when detected close to the creation vertex--suffer a reduced energy loss due to the internal screening of the charges constituting the pair. Furthermore, the ability to measure directly the energy of the pair by calorimetry enables a comparison with theory as a function of energy. The observed phenomenon is in good qualitative agreement with general expectations from the Chudakov effect but indicates a quantitative disagreement with either of two mutually disagreeing theories. PMID:18518209

Virkus, T; Thomsen, H D; Uggerhøj, E; Uggerhøj, U I; Ballestrero, S; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Kartal, S; Pagliarone, C

2008-04-25

48

Halo Effect on Direct Neutron Capture Process  

NASA Astrophysics Data System (ADS)

We calculate the capture cross sections of the 10Be(n,gamma) 11Be reaction by means of the asymptotic normalization coefficient method and demonstrate the halo effects on the capture cross sections for the direct radiative neutron capture where a p-, s- or d-wave neutron is captured into an s-orbit or p-orbit in 11Be by emitting an E1 gamma-ray, respectively. The result shows that the enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo, which is clearly illustrated by the reduced transition amplitude function.

Liu, Zu-Hua; Zhou, Hong-Yu

2004-01-01

49

77 FR 53769 - Receipts-Based, Small Business Size Standard; Confirmation of Effective Date  

Federal Register 2010, 2011, 2012, 2013

...3150-AJ14 Receipts-Based, Small Business Size Standard; Confirmation of Effective Date...This direct final rule amended the size standard that the NRC uses to qualify an...increasing its receipts-based, small business size standard from $6.5 million to $7...

2012-09-04

50

Direct and indirect effects of adenosine 5'-triphosphate on guinea-pig ileum.  

PubMed

1 The inhibitory effects of adenosine 5'-triphosphate (ATP) were compared on the responses to electrical stimulation, and to direct and indirect stimulation by drugs of the longitudinal smooth muscle of guinea-pig ileum before and after blocking nervous activity. 2 While the major inhibitory effect of ATP was an indirect one on the intramural excitatory nerves, there was also a small direct effect on the muscle. 3 ATP also had direct and indirect excitatory effects. The direct effect particularly was only seen with high concentrations of ATP, but the appearance of these excitatory effects may be affected by the inhibitory actions. PMID:6960963

Watt, A J

1982-12-01

51

An incrementally non-linear model for clays with directional stiffness and a small strain emphasis  

NASA Astrophysics Data System (ADS)

In response to construction activities and loads from permanent structures, soil generally is subjected to a variety of loading modes varying both in time and location. It also has been increasingly appreciated that the strains around well-designed foundations, excavations and tunnels are mostly small, with soil responses at this strain level generally being non-linear and anisotropic. To make accurate prediction of the performance of a geo-system, it is highly desirable to understand soil behavior at small strains along multiple loading directions, and accordingly to incorporate these responses in an appropriate constitutive model implemented in a finite element analysis. This dissertation presents a model based on a series of stress probe tests with small strain measurements performed on compressible Chicago glacial clays. The proposed model is formulated in an original constitutive framework, in which the tangent stiffness matrix is constructed in accordance with the mechanical nature of frictional materials and the tangent moduli therein are described explicitly. The stiffness description includes evolution relations with regard to length of stress path, and directionality relations in terms of stress path direction. The former relations provide distinctive definitions for small-strain and large-strain behaviors, and distinguish soil responses in shearing and compression. The latter relations make this model incrementally non-linear and thus capable of modeling inelastic behavior. A new algorithm based on a classical substepping scheme is developed to numerically integrate this model. A consistent tangent matrix is derived for the proposed model with the upgraded substepping scheme. The code is written in FORTRAN and implemented in FEM via UMAT of ABAQUS. The model is exercised in a variety of applications ranging from oedometer, triaxial and biaxial test simulations to a C-class prediction for a well-instrumented excavation. The computed results indicate that this model is successful in reproducing soil responses in both laboratory and field situations.

Tu, Xuxin

52

Pathogen reduction requirements for direct potable reuse in Antarctica: evaluating human health risks in small communities.  

PubMed

Small, remote communities often have limited access to energy and water. Direct potable reuse of treated wastewater has recently gained attention as a potential solution for water-stressed regions, but requires further evaluation specific to small communities. The required pathogen reduction needed for safe implementation of direct potable reuse of treated sewage is an important consideration but these are typically quantified for larger communities and cities. A quantitative microbial risk assessment (QMRA) was conducted, using norovirus, giardia and Campylobacter as reference pathogens, to determine the level of treatment required to meet the tolerable annual disease burden of 10(-6) DALYs per person per year, using Davis Station in Antarctica as an example of a small remote community. Two scenarios were compared: published municipal sewage pathogen loads and estimated pathogen loads during a gastroenteritis outbreak. For the municipal sewage scenario, estimated required log10 reductions were 6.9, 8.0 and 7.4 for norovirus, giardia and Campylobacter respectively, while for the outbreak scenario the values were 12.1, 10.4 and 12.3 (95th percentiles). Pathogen concentrations are higher under outbreak conditions as a function of the relatively greater degree of contact between community members in a small population, compared with interactions in a large city, resulting in a higher proportion of the population being at risk of infection and illness. While the estimates of outbreak conditions may overestimate sewage concentration to some degree, the results suggest that additional treatment barriers would be required to achieve regulatory compliance for safe drinking water in small communities. PMID:23770553

Barker, S Fiona; Packer, Michael; Scales, Peter J; Gray, Stephen; Snape, Ian; Hamilton, Andrew J

2013-09-01

53

Effects of tillage practices and carbofuran exposure on small mammals  

USGS Publications Warehouse

We compared population estimates, body mass, movement, and blood chemistry of small mammals between conventionally tilled and no-till cornfields in Maryland and Pennsylvania to evaluate the effects of tillage practices and carbofuran exposure on small mammals.

Albers, P.H.; Linder, G.; Nichols, J.D.

1990-01-01

54

Measuring Teacher Effectiveness with Small Groups.  

ERIC Educational Resources Information Center

A model focuses on three levels of observable behaviors that are essential for teachers to demonstrate in small-group learning situations: (1) teacher and student questioning; (2) teacher and student interaction; and (3) teacher monitoring. Five figures are provided for recording observations. (18 references) (MLF)

Rowley, Marcia L.

1992-01-01

55

Small Impacts on Mars: Atmospheric Effects.  

National Technical Information Service (NTIS)

The objectives of this investigation were to study the interaction of the atmosphere with the surface of Mars through the impact of small objects that would generate dust and set the dust into motion in the atmosphere. The approach involved numerical simu...

R. Greeley I. V. Nemtchinov

2002-01-01

56

Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines  

SciTech Connect

In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

2004-11-16

57

Thermal effects on chaotic directed transport.  

PubMed

We study a chaotic ratchet system under the influence of a thermal environment. By direct integration of the Lindblad equation we are able to analyze its behavior for a wide range of couplings with the environment, and for different finite temperatures. We observe that the enhancement of the classical and quantum currents due to temperature depend strongly on the specific properties of the system. This makes it difficult to extract universal behaviors. We have also found that there is an analogy between the effects of the classical thermal noise and those of the finite h size. These results open many possibilities for their testing and implementation in kicked Bose-Einstein condensates and cold atoms experiments. PMID:19391825

Carlo, Gabriel G; Spina, María E

2009-02-01

58

Small Impacts on Mars: Atmospheric Effects  

NASA Technical Reports Server (NTRS)

The objectives of this investigation were to study the interaction of the atmosphere with the surface of Mars through the impact of small objects that would generate dust and set the dust into motion in the atmosphere. The approach involved numerical simulations of impacts and experiments under controlled conditions. Attachment: Atmospheric disturbances and radiation impulses caused by large-meteoroid impact in the surface of Mars.

Greeley, Ronald; Nemtchinov, Ivan V.

2002-01-01

59

Direct and Inverse Spin Switch Effect in Superconducting Spin Valves  

NASA Astrophysics Data System (ADS)

We report the observation of direct and inverse spin switch effects in ferromagnet/ superconductor/ ferromagnet/ antiferromagnet (FM/SC/FM/AF) spin valves with FM = Ni81Fe19, AF = Ir25Mn75 and SC=Nb. In these spin valve structures, the magnetization of the free layer can be switched between parallel (P) and antiparallel (AP) orientations with respect to the orientation of the fixed layer by a small in-plane magnetic field. Near the superconducting transition temperature, the P state has a higher resistance than the AP state. This is the direct spin switch effect expected from the proximity effect in superconducting spin valves. However, when the fixed ferromagnetic layer is brought into a multi-domain state in zero magnetic field, resistance in this state becomes significantly higher than that of the P state and rapidly decreases to the P state value with increasing magnetic field. We explain this inverse spin switch effect by the formation of N'eel - quasi-N'eel domain wall pairs in the ferromagnetic bilayer. The N'eel - quasi-N'eel domain wall pairs induce stray magnetic fields with a significant component perpendicular to the plane of the sample. This field penetrates the SC and gives rise to vortex flow resistance. Our work shows that the inverse spin switch effect is magnetostatic in origin.

Zhu, Jian; Boone, Carl; Cheng, Xiao; Krivorotov, Ilya

2009-03-01

60

Effects of Facilitator-Directed and Self-Directed Group Experiences  

ERIC Educational Resources Information Center

Compares the effectiveness of facilitator-directed (FD) to self-directed (SD) sensitivity training group experiences in a counselor education training program on the development of interpersonal perceptions of congruency and disclosure. (Author)

Conyne, Robert K.

1974-01-01

61

Effect of boron on the sliding wear of directionally solidified high-chromium white irons  

Microsoft Academic Search

The effect of small amounts of boron (less than 195ppm) added to a 16%Cr white iron were studied. Bars of 13mm diameter were directionally solidified into hot ceramic moulds and heat was extracted from the bottom by a water cooled copper plate. The microstructure showed aligned eutectic carbides in the direction of the heat flow with a finer structure for

R. Correa; A. Bedolla-Jacuinde; J. Zuno-Silva; I. Mejía

2009-01-01

62

Combination small molecule PPT1 mimetic and CNS-directed gene therapy as a treatment for infantile neuronal ceroid lipofuscinosis  

PubMed Central

Infantile neuronal ceroid lipofuscinosis (INCL) is a profoundly neurodegenerative disease of children caused by a deficiency in the lysosomal enzyme palmitoyl protein thioesterase-1 (PPT1). There is currently no effective therapy for this invariably fatal disease. To date, preclinical experiments using single treatments have resulted in incremental clinical improvements. Therefore, we determined the efficacy of CNS-directed AAV2/5-mediated gene therapy alone and in combination with the systemic delivery of the lysosomotropic PPT1 mimetic phosphocysteamine. Since CNS-directed gene therapy provides relatively high levels of PPT1 activity to specific regions of the brain, we hypothesized that phosphocysteamine would complement that activity in regions expressing sub therapeutic levels of the enzyme. Results indicate that CNS-directed gene therapy alone provided the greatest improvements in biochemical and histological measures as well as motor function and life span. Phosphocysteamine alone resulted in only minor improvements in motor function and no increase in lifespan. Interestingly, phosphocysteamine did not increase the biochemical and histological response when combined with AAV2/5-mediated gene therapy, but it did result in an additional improvement in motor function. These data suggest that a CNS-directed gene therapy approach provides significant clinical benefit, and the addition of the small molecule PPT1 mimetic can further increase that response.

Roberts, Marie S.; Macauley, Shannon L.; Wong, Andrew M.; Yilmas, Denis; Hohm, Sarah; Cooper, Jonathan D.; Sands, Mark S.

2014-01-01

63

Direct Demonstration of the Greenhouse Effect  

NASA Astrophysics Data System (ADS)

Consider these three "theories:" climate change, evolution, and gravity. Why are two of them hotly debated by non-scientists, but not gravity? In part, the answer is that climate change and evolution are more complex processes and not readily observable over short time scales to most people. In contrast, the "theory of gravity" is tested every day by billions of people world-wide and is therefore not challenged. While there are numerous "demonstrations" of the greenhouse effect available online, unfortunately, many of them are based on poor understanding of the physical principles involved. For this reason, we sought to develop simple and direct experiments that would demonstrate aspects of the greenhouse effect that would be suitable for museums, K-12, and/or college classrooms. We will describe two experiments. In the first, we use a simple plexiglass tube, approximately 12 cm long, with IR transparent windows. The tube is first filled with dry nitrogen and exposed to an IR heat lamp. Following this, the tube is filled with pure, dry CO2. Both tubes warm up, but the tube filled with CO2 ends up about 0.7 degrees C warmer. It is useful to compare this 12 cm column of CO2 to the column in the earth's atmosphere, which is equivalent to approximately 2.7 meters of pure CO2. This demonstration would be suitable for museum exhibits to demonstrate the physical basis of CO2 heating in the atmosphere. In the second experiment, we use FTIR spectroscopy to quantify the CO2 content of ambient air and indoor/classroom air. For this experiment, we use a commercial standard of 350 ppm CO2 to calibrate the absorption features. Once the CO2 content of ambient air is found, it is useful for students to compare their observed value to background data (e.g. NOAA site in Hawaii) and/or the "Keeling Curve". This leads into a discussion on causes for local variations and the long-term trends. This experiment is currently used in our general chemistry class but could be used in many other science classes. Both of the above experiments should lead to a greater understanding of the scientific basis for the greenhouse effect.

Jaffe, D. A.; Malashanka, S.; Call, K.; Bernays, N.

2012-12-01

64

Bi-directional small form pluggable optical transceiver using an integrated WDM optical subassembly  

NASA Astrophysics Data System (ADS)

The 1.3/1.55 ?m bi-directional small form pluggable (SFP) optical transceiver with an integrated wavelength division multiplexing (WDM) subassembly using accurate ceramic blocks has been developed. The WDM subassembly on which a laser diode (LD), a receiver photodiode (r-PD), a WDM filter, and two micro lenses are integrated is only 2.0 x 2.1 x 0.6 mm 3 in size and inserted in a TO-CAN package. The SFP transceiver coupled with single mode fiber has been operated at a 622Mbps data rate. The transmitted optical output power is -2.8 dBm and the measured value of sensitivity is -32 dBm at 10 -10 Bit Error Rate (BER).

Yoon, Hyun-Jae; Cho, Hyun-Woo; Cho, Young-Uk; Kim, Ki-Dae

2006-10-01

65

Direction and polarization estimation using arrays with small loops and short dipoles  

NASA Astrophysics Data System (ADS)

This paper shows that when polarization-sensitive arrays consisting of crossed small loops and short dipoles are used, one can eliminate the requirement in the ESPRIT algorithm that sensors must occur in matched pairs. The dipoles and loops are sensitive to the polarizations of incident electromagnetic plane waves. The dipoles are sensitive to the incident electric field components and the loops to magnetic field components of the incident waves. We exploit the invariance properties among the dipole and loop outputs of an arbitrary array of orthogonal loops and orthogonal dipoles to compute both the two-dimensional arrival angles and polarizations of incoming narrow-band signals. We also show that with dipoles and loops, vertical arrays are not necessary to obtain good direction estimates for signals from low angles.

Li, Jian

1993-03-01

66

Design Study of Coated Conductor Direct Drive Wind Turbine Generator for Small Scale Demonstration  

NASA Astrophysics Data System (ADS)

We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting ?eld windings is based on properties of coated conductors wound into coils holding of the order 68 meters of tape. The active mass of the generators has been investigated as function of the number of poles and a 4 pole generator is suggested as a feasible starting point of an in-?eld demonstration of the system reliability. An active mass of m = 421 kg and a usage of 3.45 km of tape will be needed to realize such a generator with a peak ?ux density in the airgap of B0 = 1.5 T.

Abrahamsen, Asger B.; Jensen, Bogi B.

67

Duty cycle effects on small engine emissions  

SciTech Connect

The paper presents emissions data obtained from seven lawn mower engines that were tested using three duty cycles: a six mode steady-state test, a quasi-steady-state test, and a transient test. A comparison of emissions from the three duty cycles is made for non-methane organic gases, carbon monoxide, nitrogen oxides, detailed hydrocarbons (percent of total organic emissions that are paraffin, olefin, aromatic, or acetylene), and toxic compounds (benzene, 1,3-butadiene, formaldehyde, and acetaldehyde). Dufferences in ozone potential are also determined and reported for each duty cycle. The study includes both regulated and unregulated (not certified to any emission standard) test engines that have a wide range of emission rates. Results indicate that regulated emission rate differences due to duty cycle are fairly small (less than ten percent on the average). For over half of the regulated emission data, there is no significant difference in emission rates between data obtained using the steady-state and transient duty cycle. Emission comparisons are even better between the quasi-steady-state and steady-state data.

Gabele, P.

1998-06-01

68

Mapping small DNA sequences by fluorescence in situ hybridization directly on banded metaphase chromosomes  

SciTech Connect

A procedure for mapping small DNA probes directly on banded human chromosomes by fluorescence in situ hybridization has been developed. This procedure allows for the simultaneous visualization of banded chromosomes and hybridization signal without overlaying two separate photographic images. This method is simple and rapid, requires only a typical fluorescence microscope, has proven successful with DNA probes as small as 1 kilobase, is applicable for larger probes, and will greatly facilitate mapping the vast number of probes being generated to study genetic disease and define the human genome. Human metaphase chromosomes were prepared from phytohemagglutinin-stimulated lymphocyte cultures synchronized with bromodeoxyuridine and thymidine. Probes were labeled with biotin-dUTP, and the hybridization signal was amplified by immunofluorescence. Chromosomes were stained with both propidium iodide and 4{prime},6-diamidino-2-phenylindole (DAPI), producing R- and Q-banding patterns, respectively, allowing unambiguous chromosome and band identification while simultaneously visualizing the hybridization signal. Thirteen unique DNA segments have been localized to the long arm of chromosome 11 by using this technique, and localization of 10 additional probes by using radioactive in situ hybridization provides a comparison between the two procedures. These DNA segments have been mapped to all long-arm bands on chromosome 11 and in regions associated with neoplasias and inherited disorders.

Fan, Y.S.; Davis, L.M.; Shows, T.B. (New York State Department of Health, Buffalo (USA))

1990-08-01

69

Mapping small DNA sequences by fluorescence in situ hybridization directly on banded metaphase chromosomes.  

PubMed

A procedure for mapping small DNA probes directly on banded human chromosomes by fluorescence in situ hybridization has been developed. This procedure allows for the simultaneous visualization of banded chromosomes and hybridization signal without overlaying two separate photographic images. This method is simple and rapid, requires only a typical fluorescence microscope, has proven successful with DNA probes as small as 1 kilobase, is applicable for larger probes, and will greatly facilitate mapping the vast number of probes being generated to study genetic disease and define the human genome. Human metaphase chromosomes were prepared from phytohemagglutinin-stimulated lymphocyte cultures synchronized with bromodeoxyuridine and thymidine. Probes were labeled with biotin-dUTP, and the hybridization signal was amplified by immunofluorescence. Chromosomes were stained with both propidium iodide and 4',6-diamidino-2-phenylindole (DAPI), producing R- and Q-banding patterns, respectively, allowing unambiguous chromosome and band identification while simultaneously visualizing the hybridization signal. Thirteen unique DNA segments have been localized to the long arm of chromosome 11 by using this technique, and localization of 10 additional probes by using radioactive in situ hybridization provides a comparison between the two procedures. These DNA segments have been mapped to all long-arm bands on chromosome 11 and in regions associated with neoplasias and inherited disorders. PMID:2201023

Fan, Y S; Davis, L M; Shows, T B

1990-08-01

70

Effects of Ocular Optics on Perceived Visual Direction and Depth  

NASA Astrophysics Data System (ADS)

Most studies of human retinal image quality have specifically addressed the issues of image contrast, few have examined the problem of image location. However, one of the most impressive properties of human vision involves the location of objects. We are able to identify object location with great accuracy (less than 5 arcsec). The sensitivity we exhibit for image location indicates that any optical errors, such as refractive error, ocular aberrations, pupil decentration, etc., may have noticeable effects on perceived visual direction and distance of objects. The most easily observed effects of these optical factors is a binocular depth illusion called chromostereopsis in which equidistance colored objects appear to lie at the different distances. This dissertation covers a series of theoretical and experimental studies that examined the effects of ocular optics on perceived monocular visual direction and binocular chromostereopsis. Theoretical studies included development of an adequate eye model for predicting chromatic aberration, a major ocular aberration, using geometric optics. Also, a wave optical analysis is used to model the effects of defocus, optical aberrations, Stiles-Crawford effect (SCE) and pupil location on retinal image profiles. Experimental studies used psychophysical methods such as monocular vernier alignment tests, binocular stereoscopic tests, etc. This dissertation concludes: (1) With a decentered large pupil, the SCE reduces defocused image shifts compare to an eye without the SCE. (2) The blurred image location can be predicted by the centroid of the image profile. (3) Chromostereopsis with small pupils can be precisely accounted for by the interocular difference in monocular transverse chromatic aberration. (4) The SCE also plays an important role in the effect of pupil size on chromostereopsis. The reduction of chromostereopsis with large pupils can be accurately predicted by the interocular difference in monocular chromatic diplopia which is also reduced with large pupils. This supports the hypothesis that the effect of pupil size on chromostereopsis is due to monocular mechanisms.

Ye, Ming

71

EGFR inhibition in non-small cell lung cancer: current evidence and future directions  

PubMed Central

EGFR inhibition has emerged to be an important strategy in the treatment of non-small cell lung cancer (NSCLC). Small molecule tyrosine kinase inhibitors (TKIs) and mono-clonal antibodies (mAbs) to the EGFR have been tested in multiple large randomized phase III studies alone or combined with chemotherapy, as well as small phase I-II studies which investigated their efficacy as radiosensitizers when combined with radiotherapy. In this review, we described the current clinical outcome after treatment with EGFR TKIs and mAbs alone or combined with chemotherapy in advanced stage NSCLC, as well as the early findings in feasibility/phase I or II studies regarding to whether EGFR TKI or mAb can be safely and effectively combined with radiotherapy in the treatment of locally advanced NSCLC. Furthermore, we explore the potential predictive biomarkers for response to EGFR TKIs or mAbs in NSCLC patients based on the findings in the current clinical trials; the mechanisms of resistance to EGFR inhibition; and the strategies of augmenting the antitumor activity of the EGFR inhibitors alone or when combined with chemotherapy or radiotherapy.

2013-01-01

72

Small mammals cause non-trophic effects on habitat and associated snails in a native system  

Microsoft Academic Search

Legacy effects occur when particular species or their interactions with others have long-lasting impacts, and they are increasingly\\u000a recognized as important determinants of ecological processes. However, when such legacy effects have been explicitly explored,\\u000a they most often involve the long-term direct effects of species on systems, as opposed to the indirect effects. Here, we explore\\u000a how a legacy of small

Mikaela Huntzinger; Richard Karban; John L. Maron

73

Battery Voltage Stability Effects on Small Wind Turbine Energy Capture.  

National Technical Information Service (NTIS)

Previous papers on small wind turbines have shown that the ratio of battery capacity to wind capacity (known as battery-wind capacity ratio) for small wind systems with battery storage has an important effect on wind turbine energy output. Data analysis f...

D. Corbus C. Newcomb E. I. Baring-Gould S. Friedly

2002-01-01

74

Effectiveness of Small Group Social Skills Lessons with Elementary Students  

ERIC Educational Resources Information Center

This action research study (ARS) describes the effectiveness of small group social skills lessons with elementary students, using "Too Good for Violence: A Curriculum for Non-violent Living" by the Mendez Foundation. The school counselor and school social worker taught the curriculum in a structured small group of 4th grade students in 8 weekly…

Chupp, Amy I.; Boes, Susan R.

2012-01-01

75

Effects of the small delays in robotic control systems  

Microsoft Academic Search

There are analyses of the effects of the small delays in the feedback loop that inevitably lead the systems into an unstable situation. How small must be the delay in real conditions such that to preserve the system stability, is studied and analyzed for a robot manipulator. The case of an adaptive controller is also developed for the robot system

Mirela TRUSCA; G. Lazea; P. Dobra

2006-01-01

76

Neural Control of Posture During Small Magnitude Perturbations: Effects of Aging and Localized Muscle Fatigue  

Microsoft Academic Search

This study investigated the effects of aging and local- ized muscle fatigue on the neural control of upright stance during small postural perturbations. Sixteen young (aged 18-24 years) and 16 older (aged 55-74 years) participants were exposed to small magnitude, anteriorly-directed postural perturbations before and after fatiguing exercises (lumbar extensors and ankle plantar flex- ors). A single degree of freedom

Bradley S. Davidson; Michael L. Madigan; Steve C. Southward; Maury A. Nussbaum

2011-01-01

77

Direct formation of small Cu2O nanocubes, octahedra, and octapods for efficient synthesis of triazoles.  

PubMed

In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH·HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis. PMID:24947435

Tsai, Ya-Huei; Chanda, Kaushik; Chu, Yi-Ting; Chiu, Chun-Ya; Huang, Michael H

2014-07-10

78

Effects of Directional Exercise on Lingual Strength  

ERIC Educational Resources Information Center

Purpose: To examine the application of known muscle training principles to tongue strengthening exercises and to answer the following research questions: (a) Did lingual strength increase following 9 weeks of training? (b) Did training conducted using an exercise moving the tongue in one direction result in strength changes for tongue movements in…

Clark, Heather M.; O'Brien, Katy; Calleja, Aimee; Corrie, Sarah Newcomb

2009-01-01

79

Wong's equations and the small x effective action in QCD  

SciTech Connect

We propose a new form for the small x effective action in QCD. This form of the effective action is motivated by Wong's equations for classical, colored particles in non-Abelian background fields. We show that the BFKL equation, which sums leading logarithms in x, is efficiently reproduced with this form of the action. We argue that this form of the action may be particularly useful in computing next-to-leading-order results in QCD at small x.

Jalilian-Marian, Jamal; Jeon, Sangyong; Venugopalan, Raju

2001-02-01

80

The effect of very small air gaps on small field dosimetry  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the effect of very small air gaps (less than 1 mm) on the dosimetry of small photon fields used for stereotactic treatments. Measurements were performed with optically stimulated luminescent dosimeters (OSLDs) for 6 MV photons on a Varian 21iX linear accelerator with a Brainlab µMLC attachment for square field sizes down to 6 mm × 6 mm. Monte Carlo simulations were performed using EGSnrc C++ user code cavity. It was found that the Monte Carlo model used in this study accurately simulated the OSLD measurements on the linear accelerator. For the 6 mm field size, the 0.5 mm air gap upstream to the active area of the OSLD caused a 5.3% dose reduction relative to a Monte Carlo simulation with no air gap. A hypothetical 0.2 mm air gap caused a dose reduction >2%, emphasizing the fact that even the tiniest air gaps can cause a large reduction in measured dose. The negligible effect on an 18 mm field size illustrated that the electronic disequilibrium caused by such small air gaps only affects the dosimetry of the very small fields. When performing small field dosimetry, care must be taken to avoid any air gaps, as can be often present when inserting detectors into solid phantoms. It is recommended that very small field dosimetry is performed in liquid water. When using small photon fields, sub-millimetre air gaps can also affect patient dosimetry if they cannot be spatially resolved on a CT scan. However the effect on the patient is debatable as the dose reduction caused by a 1 mm air gap, starting out at 19% in the first 0.1 mm behind the air gap, decreases to <5% after just 2 mm, and electronic equilibrium is fully re-established after just 5 mm.

Charles, P. H.; Crowe, S. B.; Kairn, T.; Kenny, J.; Lehmann, J.; Lye, J.; Dunn, L.; Hill, B.; Knight, R. T.; Langton, C. M.; Trapp, J. V.

2012-11-01

81

The effect of very small air gaps on small field dosimetry.  

PubMed

The purpose of this study was to investigate the effect of very small air gaps (less than 1 mm) on the dosimetry of small photon fields used for stereotactic treatments. Measurements were performed with optically stimulated luminescent dosimeters (OSLDs) for 6 MV photons on a Varian 21iX linear accelerator with a Brainlab µMLC attachment for square field sizes down to 6 mm × 6 mm. Monte Carlo simulations were performed using EGSnrc C++ user code cavity. It was found that the Monte Carlo model used in this study accurately simulated the OSLD measurements on the linear accelerator. For the 6 mm field size, the 0.5 mm air gap upstream to the active area of the OSLD caused a 5.3% dose reduction relative to a Monte Carlo simulation with no air gap. A hypothetical 0.2 mm air gap caused a dose reduction >2%, emphasizing the fact that even the tiniest air gaps can cause a large reduction in measured dose. The negligible effect on an 18 mm field size illustrated that the electronic disequilibrium caused by such small air gaps only affects the dosimetry of the very small fields. When performing small field dosimetry, care must be taken to avoid any air gaps, as can be often present when inserting detectors into solid phantoms. It is recommended that very small field dosimetry is performed in liquid water. When using small photon fields, sub-millimetre air gaps can also affect patient dosimetry if they cannot be spatially resolved on a CT scan. However the effect on the patient is debatable as the dose reduction caused by a 1 mm air gap, starting out at 19% in the first 0.1 mm behind the air gap, decreases to <5% after just 2 mm, and electronic equilibrium is fully re-established after just 5 mm. PMID:23044638

Charles, P H; Crowe, S B; Kairn, T; Kenny, J; Lehmann, J; Lye, J; Dunn, L; Hill, B; Knight, R T; Langton, C M; Trapp, J V

2012-11-01

82

Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report  

SciTech Connect

Advancement of U.S. scientific, security, and economic interests requires high performance propulsion systems to support missions beyond low Earth orbit. A robust space exploration program will include robotic outer planet and crewed missions to a variety of destinations including the moon, near Earth objects, and eventually Mars. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option for the human exploration of Mars because of its high thrust and high specific impulse ({approx}900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. The recently announced national space policy2 supports the development and use of space nuclear power systems where such systems safely enable or significantly enhance space exploration or operational capabilities. An extensive nuclear thermal rocket technology development effort was conducted under the Rover/NERVA, GE-710 and ANL nuclear rocket programs (1955-1973). Both graphite and refractory metal alloy fuel types were pursued. The primary and significantly larger Rover/NERVA program focused on graphite type fuels. Research, development, and testing of high temperature graphite fuels was conducted. Reactors and engines employing these fuels were designed, built, and ground tested. The GE-710 and ANL programs focused on an alternative ceramic-metallic 'cermet' fuel type consisting of UO2 (or UN) fuel embedded in a refractory metal matrix such as tungsten. The General Electric program examined closed loop concepts for space or terrestrial applications as well as open loop systems for direct nuclear thermal propulsion. Although a number of fast spectrum reactor and engine designs suitable for direct nuclear thermal propulsion were proposed and designed, none were built. This report summarizes status results of evaluations of small nuclear reactor designs suitable for direct nuclear thermal propulsion.

Bruce G. Schnitzler

2012-01-01

83

Effective direct methods for aerodynamic shape optimization  

NASA Astrophysics Data System (ADS)

A direct method for aerodynamic shape optimization based on the use of Bézier spline approximation is proposed. The method is tested as applied to the optimization of the supersonic part of an axisymmetric de Laval nozzle. The optimization results are compared with the exact solution obtained by the control contour method (variational nozzle) and with nozzles constructed using another direct method, namely, local linearization. It is shown that both direct optimization methods can be used on rather coarse grids without degrading the accuracy of the solution. The optimization procedure involves the isoperimetric condition that the surface area of the nozzle is given and fixed, which prevents the use of the control contour method. Optimization with allowance for viscosity is performed using the method. For fairly short maximum possible nozzle lengths in the range of Reynolds numbers under consideration, it is shown that allowance for viscosity does not improve the nozzle shape produced by optimization based on the Euler equations. The role of viscosity is reduced to the determination of an optimal length.

Kraiko, A. A.; P'yankov, K. S.

2010-09-01

84

New Directions for Learning About Safety Effectiveness.  

National Technical Information Service (NTIS)

Some basic issues concerning the evaluation of highway safety measures are raised. A simple technique is proposed for avoiding many of the pitfalls of before/after evaluations, which potentially yield inflated estimates of safety measure effectiveness. Th...

E. Hauer J. Lovell B. N. Persaud

1986-01-01

85

Management and future directions in non-small cell lung cancer with known activating mutations.  

PubMed

Lung cancer accounts for a quarter of all cancer deaths. Non-small cell lung cancer (NSCLC) is currently segregated by the presence of actionable driver oncogenes. This review will provide an overview of molecular subsets of lung cancer, including descriptions of the defining oncogenes (EGFR, ALK, KRAS, ROS1, RET, BRAF, ERBB2, NTRK1, FGFR, among others) and how these predict for response to small molecule tyrosine kinase inhibitors (TKIs) that are either clinically available or in clinical trial development for advanced NSCLC. Particular focus will be placed on subsets with EGFR mutated and ALK rearranged NSCLC. Somatic TKI-sensitizing EGFR mutations (such as exon 19 deletions and L858R substitutions) are the most robust predictive biomarker for symptom improvement, radiographic response, and increment in progression-free survival (PFS) when EGFR TKIs (gefitinib, erlotinib, and afatinib) are used for patients with advanced NSCLC. However, the palliative benefits that EGFR TKIs afford are limited by multiple biologic mechanisms of tumor adaptation/resistance (such as the EGFR-T790M mutation and oncogene bypass tracks), and future efforts toward delaying, preventing, and treating resistance are underway. Similar to EGFR mutations, ALK rearrangements exemplify an oncogene-driven NSCLC that can be effectively palliated with a precision TKI therapy (the multitargeted ALK/MET/ROS1 TKI crizotinib). When resistance to first-line crizotinib therapy occurs, multiple second generation ALK TKIs have demonstrated impressive rates of disease control in clinical trials, and these may modify long-term outcomes for patients with ALK-positive NSCLC. The development of TKIs for other oncogene-driven NSCLCs may expand the portfolio of precision therapies for this recalcitrant cancer. PMID:24857124

Gerber, David E; Gandhi, Leena; Costa, Daniel B

2014-01-01

86

Effect of nuclear deformation on direct capture reactions  

NASA Astrophysics Data System (ADS)

Direct radiative capture processes are well described by a spherical potential model. Since most nuclei are not spherical, and in order for the model to explain direct radiative captures more accurately, the effect of nuclear deformation has been analyzed with q-deformed Woods-Saxon potential in this work. The results imply that nuclear deformation largely affects the direct radiative capture, and it should be taken into account when discussing direct capture reactions.

Fan, Guang-Wei; Cai, Xiao-Lu; Fukuda, M.; Han, Ti-Fei; Li, Xue-Chao; Ren, Zhong-Zhou; Xu, Wang

2014-04-01

87

Quantum field-effect directional coupler  

NASA Astrophysics Data System (ADS)

A new quantum-effect electronic device is proposed which consists of two one-dimensional electron waveguides which, over a certain interaction length, come in close proximity to each other so that coherent quantum mechanical tunneling can take place between them. The degree of coupling between the two waveguides is controlled by modulating, through the field-effect action of a gate, the height of the potential energy barrier which separates them. If an electron wave packet is injected into this device through one of the waveguides, then the probability density of the electron wave function will oscillate back and forth between the two waveguides as the packet advances. The gate voltage can be adjusted to achieve complete electron transfer at either of the two waveguides at the output of the device. The device, therefore, behaves as a current switch. First-order calculations indicate that this device can be fabricated with state-of-the-art nanolithography.

del Alamo, Jesus A.; Eugster, Cristopher C.

1990-01-01

88

Does telaprevir possess a direct antidiabetic effect?  

PubMed

Hepatitis C virus (HCV) induces insulin resistance, which improves upon viral clearance. Telaprevir is a protease inhibitor effective against HCV genotype 1. We reported a case, whose history suggests that telaprevir may induce some antidiabetic effect independently of its suppression of HCV. A 56-year-old woman with obesity, type 2 diabetes treated with sitagliptin and metformin, and HCV-related cirrhosis was given triple therapy with pegylated interferon-alpha, ribavirin and telaprevir. After 2 weeks of treatment, HCV RNA was no longer detectable but the patient described a pronounced drop in the capillary glucose levels and episodes of hypoglycaemia that compelled her to stop all antidiabetic treatment. One month after stopping telaprevir, she had to resume her antidiabetic treatment, despite a persisting virological response. Despite reaching a sustained virological response, her diabetes progressed. Although the suppression of HCV replication may have played a role in reducing glucose intolerance, the fact that this patient resumed her prior antidiabetic treatment upon completing the telaprevir treatment, while still aviremic, suggests that telaprevir may have an additional antidiabetic effect. Further evidence about the possible role and mechanisms of telaprevir as antidiabetic agent is warranted. PMID:24329983

Tallón de Lara, Paulino; Himschoot, Thomas; Frossard, Jean-Louis; Negro, Francesco

2014-07-01

89

Size-dependent effects in solutions of small metal nanoparticles  

NASA Astrophysics Data System (ADS)

A new theoretical approach for the calculation of optical properties of complex solutions is proposed. It is based on a dielectric matrix ?m with included small metallic inclusions (less than 3 nm) of spherical shape. We take into account the mutual interactions between the inclusions and the quantum finite-size effects. On the basis of the effective medium model, TDLDA and Kohn-Sham theories, some analytical expressions for the effective dielectric permittivity of the solution are obtained.

Pustovit, V. N.; Shahbazyan, T. V.; Grechko, L. G.

2009-06-01

90

Synopsis of Direct and Indirect Lightning Effects on Composite Materials  

NASA Technical Reports Server (NTRS)

NASA's Space Environments and Effects (SEE) Program funded a study on electromagnetic environmental effect issues of composite materials used by the aerospace industry. The results of which are published by Ross Evans, Tec-Masters Inc., in NASA-CR-4783, "Test Report - Direct and Indirect Lightning Effects on Composite Materials." Indirect effects include the electric and magnetic field shielding provided by a composite material illuminated by a near or direct lightning strike. Direct effects includes the physical damage of composites and/or assembly joint with a direct strike injection. This paper provides a synopsis of NASA-CR-4783. A short description is provided of the direct and indirect tests performed during the sturdy. General results and design guidelines are discussed.

Clark, Tony

1998-01-01

91

Changing Effects of Direct-to-Consumer Broadcast Drug Advertising Information Sources on Prescription Drug Requests  

Microsoft Academic Search

This study tracks the changes of the effects of 4 information sources for direct-to-consumer drug advertising on patients' requests for prescription drugs from physicians since the inception of the “Guidance for Industry about Consumer-directed Broadcast Advertisements.” The Guidance advises pharmaceuticals to use four information sources for consumers to seek further information to supplement broadcast drug advertisements: small-print information, the Internet,

Annisa Lai Lee

2009-01-01

92

Using the sensitive dependence of chaos (the ``butterfly effect'') to direct trajectories in an experimental chaotic system  

NASA Astrophysics Data System (ADS)

In this paper we present the first experimental verification that the sensitivity of a chaotic system to small perturbations (the ``butterfly effect'') can be used to rapidly direct orbits from an arbitrary initial state to an arbitrary accessible desired state.

Shinbrot, Troy; Ditto, William; Grebogi, Celso; Ott, Edward; Spano, Mark; Yorke, James A.

1992-05-01

93

Using the sensitive dependence of chaos (the ``butterfly effect'') to direct trajectories in an experimental chaotic system  

Microsoft Academic Search

In this paper we present the first experimental verification that the sensitivity of a chaotic system to small perturbations (the ``butterfly effect'') can be used to rapidly direct orbits from an arbitrary initial state to an arbitrary accessible desired state.

Troy Shinbrot; William Ditto; Celso Grebogi; Edward Ott; Mark Spano; James A. Yorke

1992-01-01

94

Controlling Chaos: Using the Butterfly Effect to Direct Trajectories to Targets in Chaotic Systems.  

NASA Astrophysics Data System (ADS)

We develop a method which uses the exponential sensitivity of a chaotic system to tiny perturbations (the "butterfly effect") to direct the system to a desired accessible state in a short time. We show that, in one of the cases studied, a neighborhood which would typically take 10,000,000,000 time units to reach without control can be reached using our technique in only about 10 of the same time units. This is done by applying a small, judiciously chosen, perturbation to an available system parameter. An expression for the time required to reach an accessible state by applying such a perturbation is derived and confirmed by numerical experiment. The method introduced is shown to be effective even in the presence of small amplitude noise or small modeling errors. We also present the first verification that the butterfly effect can be used to rapidly direct orbits in an experimental chaotic system.

Shinbrot, Troy

95

Derivative expansion at small mass for the spinor effective action  

SciTech Connect

We study the small-mass limit of the one-loop spinor effective action, comparing the derivative expansion approximation with exact numerical results that are obtained from an extension to spinor theories of the partial-wave cutoff method. In this approach, one can compute numerically the renormalized one-loop effective action for radially separable gauge field background fields in spinor QED. We highlight an important difference between the small-mass limit of the derivative expansion for spinor and scalar theories.

Dunne, Gerald V. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Huet, Adolfo [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan 58040 (Mexico); Hur, Jin [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of); Min, Hyunsoo [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of)

2011-05-15

96

Antidiabetic effects of glucokinase regulatory protein small-molecule disruptors.  

PubMed

Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic ?-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus. PMID:24226772

Lloyd, David J; St Jean, David J; Kurzeja, Robert J M; Wahl, Robert C; Michelsen, Klaus; Cupples, Rod; Chen, Michelle; Wu, John; Sivits, Glenn; Helmering, Joan; Komorowski, Renée; Ashton, Kate S; Pennington, Lewis D; Fotsch, Christopher; Vazir, Mukta; Chen, Kui; Chmait, Samer; Zhang, Jiandong; Liu, Longbin; Norman, Mark H; Andrews, Kristin L; Bartberger, Michael D; Van, Gwyneth; Galbreath, Elizabeth J; Vonderfecht, Steven L; Wang, Minghan; Jordan, Steven R; Véniant, Murielle M; Hale, Clarence

2013-12-19

97

Colloidal Graphite-Assisted Laser Desorption/Ionization MS and MSn of Small Molecules. 2. Direct Profiling and MS Imaging of Small Metabolites from Fruits  

SciTech Connect

Due to a high background in the low-mass region, conventional MALDI is not as useful for detecting small molecules (molecular masses <500 Da) as it is for large ones. Also, spatial inhomogeneity that is inherent to crystalline matrixes can degrade resolution in imaging mass spectrometry (IMS). In this study, colloidal graphite was investigated as an alternative matrix for laser desorption/ionization (GALDI) in IMS. We demonstrate its advantages over conventional MALDI in the detection of small molecules such as organic acids, flavonoids, and oligosaccharides. GALDI provides good sensitivity for such small molecules. The detection limit of fatty acids and flavonoids in the negative-ion mode are in the low-femtomole range. Molecules were detected directly and identified by comparing the MS and MS/MS spectra with those of standards. Various fruits were chosen to evaluate the practical utility of GALDI since many types of small molecules are present in them. Distribution of these small molecules in the fruit was investigated by using IMS and IMS/MS.

Hui Zhang; Sangwon Cha; Edward S. Yeung

2007-09-01

98

Evolutionary Directions of the European Union Policy in favour of Small and Medium-Sized Enterprises and Entrepreneurship  

Microsoft Academic Search

The aim of the article is the presentation as well as the analysis of the most important directions of the European Union activities in favour of entrepreneurship, especially small and medium-sized enterprises (SMEs). The historical outline of SMEs’ community policy shaping was introduced. Analysing the importance and the role of SME sector in each economy as well as the community

Krzysztof Wach

2010-01-01

99

Cost effective FITL technologies for small business and residential customers  

NASA Astrophysics Data System (ADS)

FIRST is a RACE project where 5 main European telecoms operators, 4 equipment manufacturers and one university have joined up to define and test in a field trial in Portugal a cost effective Optical Access Network. The main design target has been a system which gives cost effective provision of wideband services for small and medium business customers. The system however, incorporates provision of telephone, ISDN and analog and digital video for residential customers as well. Technologies have been chosen with the objective of providing a simple, robust and flexible system where initial deployment costs are low and closely related to the service take up. The paper describes the main technical features of the system and network applications which shows how the system may be introduced in network planning. The system is based on Passive Optical Network technology where video is distributed in the 1550 nm window and telecoms services transmitted at 1300 nm in full duplex mode. The telecoms system provides high capacity, flexibility in loop length and robustness towards outside plant performance. The Subcarrier Multiple Access (SCMA) method is used for upstream transmission of bi-directional telecoms services. SCMA has advantages compared to the Time Division Multiple Access technology used in other systems. Bandwidth/cost tradeoff is better and the lower requirements to the outside plant increases the overall cost benefit. Optical beat noise due to overlapping of laser spectra which may be a problem for this technology has been addressed with success through the use of a suitable modulation and control technique. This technology is further validated in the field trial. The video system provides cost effective long distance transmission on standard fiber with externally modulated lasers and cascaded amplifiers. Coexistence of analog and digital video on one fiber with different modulation schemes i.e. BPSK, QPSK and 64 QAM have been validated. Total life cycle cost evaluations based on availability data, maintenance requirements and expectations for service development have been made. The field trial will be running for two years.

Andersen, Niels E.; Woolnough, Peter; Seidenberg, Juergen; Ferreira, Mario F.

1995-02-01

100

Effects of Racial Composition on Small Work Groups  

ERIC Educational Resources Information Center

Evaluates the effect of integration and segregation of Blacks and whites in a small group setting in a work environment. Discriminant analysis suggests that while few behavioral and attitudinal differences exist between Blacks and whites, integration is beneficial to Blacks and not detrimental to whites. (Author)

Ruhe, John; Eatman, John

1977-01-01

101

Effects of Small Group Sizes on Learning with Interactive Videodisc.  

ERIC Educational Resources Information Center

Describes study of undergraduates that compared the effects of different small group sizes on learner achievement using computer controlled interactive videodisc. The results of pretests and posttests are reported, learning achievement and instructional time are used to calculate an instructional efficiency index, and further research is…

Cockayne, Susan

1991-01-01

102

CellFateScout - a bioinformatics tool for elucidating small molecule signaling pathways that drive cells in a specific direction  

PubMed Central

Background Small molecule effects can be represented by active signaling pathways within functional networks. Identifying these can help to design new strategies to utilize known small molecules, e.g. to trigger specific cellular transformations or to reposition known drugs. Results We developed CellFateScout that uses the method of Latent Variables to turn differential high-throughput expression data and a functional network into a list of active signaling pathways. Applying it to Connectivity Map data, i.e., differential expression data describing small molecule effects, we then generated a Human Small Molecule Mechanisms Database. Finally, using a list of active signaling pathways as query, a similarity search can identify small molecules from the database that may trigger these pathways. We validated our approach systematically, using expression data of small molecule perturbations, yielding better predictions than popular bioinformatics tools. Conclusions CellFateScout can be used to select small molecules for their desired effects. The CellFateScout Cytoscape plugin, a tutorial and the Human Small Molecule Mechanisms Database are available at https://sourceforge.net/projects/cellfatescout/ under LGPLv2 license.

2013-01-01

103

Radiotherapy in Small-Cell Lung Cancer: Lessons Learned and Future Directions  

SciTech Connect

Although chemotherapy is an essential component in the treatment of small-cell lung cancer, improvements in survival in the past two decades have been mainly achieved by the appropriate application of radiotherapy. The aim of the present study was to review the key developments in thoracic radiotherapy and prophylactic cranial radiotherapy and to discuss the rationale behind key ongoing studies in small-cell lung cancer.

Slotman, Ben J., E-mail: bj.slotman@vumc.n [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Senan, Suresh [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)

2011-03-15

104

Borehole Radar Directionality in the Time Domain in Small Aperture Antennas  

Microsoft Academic Search

It is difficult to achieve significant directivi ty in the radial direction of a borehole radar antenna, b ecause the spacing of antenna elements is typically constraine d by the borehole diameter to be considerably less than a wavelength. In this paper, a time-domain technique is used to d emonstrate that the direction of incoming radiation can be det ermined

Declan Vogt; Teboho Nyareli

105

Effects of wire feeding direction and location in multiple layer diode laser direct metal deposition  

Microsoft Academic Search

This study investigates the effect of wire feeding direction, angle and location in a high power diode laser (HPDL) direct metal deposition (DMD) process for single and multilayered clad\\/parts. A 1.5kW diode laser was used to deposit single layer clad\\/track and build multilayer parts with different wire feeding conditions. These clad\\/parts were analysed using scanning electron microscopy (SEM), X-ray diffraction

Waheed Ul Haq Syed; Lin Li

2005-01-01

106

Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion  

SciTech Connect

Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine operations and the engine and stage design were constrained to fit within the payload volume of the then planned space shuttle. The SNRE core design utilized hexagonal fuel elements and hexagonal structural support elements. The total number of elements can be varied to achieve engine designs of higher or lower thrust levels. Some variation in the ratio of fuel elements to structural elements is also possible. Options for SNRE-based engine designs in the 25,000-lbf thrust range were described in a recent (2010) Joint Propulsion Conference paper. The reported designs met or exceeded the performance characteristics baselined in the DRA 5.0 Study. Lower thrust SNRE-based designs were also described in a recent (2011) Joint Propulsion Conference paper. Recent activities have included parallel evaluation and design efforts on fast spectrum engines employing refractory metal alloy fuels. These efforts include evaluation of both heritage designs from the Argonne National Laboratory (ANL) and General Electric Company GE-710 Programs as well as more recent designs. Results are presented for a number of not-yet optimized fast spectrum engine options.

Bruce G. Schnitzler; Stanley K. Borowski

2012-07-01

107

Fishing for sustainability: the effects of indirect and direct persuasion  

Microsoft Academic Search

Websites and technologies that promote sustainable behavior often employ direct persuasion by being open about persuasive intent. We examined the use of indirect persuasion, methods that do not make persuasive intent clear. We built two variants of a recipe website designed to induce changes in users: one using direct persuasion and the other using indirect methods. We measured the effects

Turadg Aleahmad; Aruna D. Balakrishnan; Jeffrey Wong; Susan R. Fussell; Sara B. Kiesler

2008-01-01

108

Weaponeering the Future: Direct Energy Weapons Effectiveness Now and Tomorrow.  

National Technical Information Service (NTIS)

Direct Energy weapons can exist on the battlefield of today, and the warfighter needs to know what Probability of Damage these weapons can attain. Currently, the Joint Munitions Effectiveness Manual calculates a Single Sortie Probability of Damage for con...

C. F. Fager

2007-01-01

109

Direct and Doppler angle-independent measurement of blood flow velocity in small-diameter vessels using ultrasound microbubbles.  

PubMed

This article represents an initial attempt to demonstrate the feasibility of a novel method for measuring flow velocity in small vessels, which is a direct, noninvasive, ultrasound-guided, and Doppler angle-independent method. In vitro, experiments were designed to mimic blood flow inside tubes. Harmonic ultrasound imaging was used to track the movement of microbubbles, and the mean flow velocity was calculated. In vivo, the flow velocities were measured in the central arteries of rabbit ears. This method can be used whenever the Doppler ultrasound cannot measure the velocity in small vessels because of either low sensitivity or Doppler angle limitation. PMID:22920365

Roy, Homagni Sikha; Zuo, Guoqing; Luo, Zhengchun; Wu, Hanping; Krupka, Tianyi M; Ran, Haitao; Li, Pan; Sun, Youping; Wang, Zhigang; Zheng, Yuanyi

2012-01-01

110

Direct cardiovascular effects of glucagon like peptide-1  

PubMed Central

Current gold standard therapeutic strategies for T2DM target insulin resistance or ? cell dysfunction as their core mechanisms of action. However, the use of traditional anti-diabetic drugs, in most cases, does not significantly reduce macrovascular morbidity and mortality. Among emerging anti-diabetic candidates, glucagon like peptide-1 (GLP-1) based therapies carry special cardiovascular implications, exerting both direct as well as indirect effects. The direct cardiovascular effects of GLP-1 and its analogs remain the focus of this review.

2013-01-01

111

A study of some effects of urbanization on storm runoff from a small watershed  

USGS Publications Warehouse

The evaluation of the effects of urbanization on the runoff characteristics of a small watershed is a problem that can be studied by either a short-range or a long-range investigation. Because the long-range type of investigation would require several years for hydrologic data accumulation, it cannot provide any immediate information on the changes in watershed behavior arising as a result of urbanization. A short-range investigation, however, based on synthetic evaluation of present data would provide immediate answers. It is in the realm of this short-range objective that this study of a small urban watershed is directed.

Espey, William Howard, Jr.; Morgan, Carl W.; Masch, Frank D.

1966-01-01

112

SUCCESSIVE SOLAR ERUPTIONS TRIGGERED BY THE COLLISION OF TWO SMALL SUNSPOTS WITH OPPOSITE POLARITIES AND MOTIONAL DIRECTIONS  

SciTech Connect

We present a study of the two successive M-class flares associated with two coronal mass ejections (CMEs) triggered by the collision of two small sunspots with opposite magnetic polarities and motional directions in NOAA active region (AR) 10484 on 2003 October 22. From the evolution of this AR in the TRACE white-light images and 96 minute line-of-sight magnetograms observed by the Michelson Doppler Imager on board SOHO, a large sunspot and a small sunspot with negative polarity rotated clockwise about 33 Degree-Sign and 18 Degree-Sign , respectively, from the northeast of a quiescent sunspot with negative polarity to the southeast from 15:00 UT on October 21 to 16:24 UT on October 23. During the process of their motion, the small sunspot with negative polarity collided with the small sunspot with positive polarity and opposite motional direction. In the collision, this AR produced two successive M-class flares and CMEs according to the observations of GOES and the Large Angle and Spectrometric Coronagraph. By analyzing the magnetic fields at polarity inversion lines (PILs) between the two small sunspot, it is found that a sudden squeeze occurred near the onset of the two M-class flares and then recovered itself after the flares. We ruled out the emergence of the magnetic fields near the PIL. According to the brightenings in TRACE 1600 A and the hard X-ray sources of the RHESSI of two M-class flares, we found that the locations of the two flares are almost situated in the same location at the PIL between the two small sunspots. We suggest that the sudden squeeze between the opposite magnetic polarities is caused by the pressure of the collision of the two small sunspots and resulted in the magnetic reconnection. These results could contribute to understanding the mechanism of flares and CMEs.

Yan, X. L.; Qu, Z. Q.; Kong, D. F. [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)

2012-03-15

113

Diclofenac acyl glucuronide, a major biliary metabolite, is directly involved in small intestinal injury in rats  

Microsoft Academic Search

Background & Aims: Enterohepatic recirculation of nonsteroidal anti-inflammatory drugs is a critical factor in the pathogenesis of intestinal injury, but the underlying mechanism of toxicity remains obscure. The aim of this study was to examine the role of diclofenac acyl glucuronide, which is the major biliary metabolite and is chemically reactive, in the precipitation of small intestinal ulceration. Methods: Hepatocanalicular

Sven Seitz; Urs A. Boelsterli

1998-01-01

114

Direction and polarization estimation using arrays with small loops and short dipoles  

Microsoft Academic Search

It is shown that when polarization-sensitive arrays consisting of crossed small loops and short dipoles are used, one can eliminate the requirement in the ESPRIT algorithm that sensors must occur in matched pairs. The dipoles and loops are sensitive to the polarizations of incident electromagnetic plane waves. The dipoles are sensitive to the incident electric field components, and the loops

Jian Li

1993-01-01

115

A Direct, Competitive Enzyme-Linked Immunosorbent Assay (ELISA) as a Quantitative Technique for Small Molecules  

ERIC Educational Resources Information Center

ELISA (enzyme-linked immunosorbent assay) is a widely used technique with applications in disease diagnosis, detection of contaminated foods, and screening for drugs of abuse or environmental contaminants. However, published protocols with a focus on quantitative detection of small molecules designed for teaching laboratories are limited. A…

Powers, Jennifer L.; Rippe, Karen Duda; Imarhia, Kelly; Swift, Aileen; Scholten, Melanie; Islam, Naina

2012-01-01

116

An incrementally non-linear model for clays with directional stiffness and a small strain emphasis  

Microsoft Academic Search

In response to construction activities and loads from permanent structures, soil generally is subjected to a variety of loading modes varying both in time and location. It also has been increasingly appreciated that the strains around well-designed foundations, excavations and tunnels are mostly small, with soil responses at this strain level generally being non-linear and anisotropic. To make accurate prediction

Xuxin Tu

2007-01-01

117

Large spin-orbit effects in small quantum dots  

Microsoft Academic Search

We consider small ballistic quantum dots weakly coupled to the leads in the\\u000achaotic regime and look for significant spin-orbit effects. We find that these\\u000aeffects can become quite prominent in the vicinity of degeneracies of many-body\\u000aenergies. We illustrate the idea by considering a case where the intrinsic\\u000aexchange term -JS^2 brings singlet and triplet many-body states near each

Ganpathy Murthy; R. Shankar

2006-01-01

118

Direct extraction of the AlGaAs\\/GaAs heterojunction bipolar transistor small-signal equivalent circuit  

Microsoft Academic Search

The authors describe a novel, direct technique for determining the small-signal equivalent circuit of a heterojunction bipolar transistor (HBT). The parasitic elements are largely determined from measurements of test structures, reducing the number of elements determined from measurements of the transistor. The intrinsic circuit elements are evaluated from y-parameter data, which are DC-embedded from the known parasitics. The equivalent-circuit elements

Damian Costa; William U. Liu; James S. Harris

1991-01-01

119

Fast and Direct Determination of Small Anions in Proteinaceous Samples Using Low Voltage-Short Tube Capillary Zone Electrophoresis System  

Microsoft Academic Search

A method was described for the fast and direct determination of small inorganic anions in samples containing large amounts of proteins, such as blood serum or milk. The method was based on gravity injection in a low separation voltage (5 kV)—short tube (Ld = 11 cm) capillary zone electrophoresis (CZE) system for the fast and quantitative determination of chloride, sulfate, phosphate, bicarbonate in serum

Weiping Yang; Zhujun Zhang

2003-01-01

120

A small molecule that directs differentiation of human ESCs into the pancreatic lineage  

Microsoft Academic Search

Stepwise differentiation from embryonic stem cells (ESCs) to functional insulin-secreting beta cells will identify key steps in beta-cell development and may yet prove useful for transplantation therapy for diabetics. An essential step in this schema is the generation of pancreatic progenitors—cells that express Pdx1 and produce all the cell types of the pancreas. High-content chemical screening identified a small molecule,

Shuibing Chen; Malgorzata Borowiak; Julia L Fox; René Maehr; Kenji Osafune; Lance Davidow; Kelvin Lam; Lee F Peng; Stuart L Schreiber; Lee L Rubin; Douglas Melton

2009-01-01

121

The Potential of Gasoline Direct Injection for Small Displacement 4Stroke Motorcycle Applications  

Microsoft Academic Search

With the introduction of increasingly more stringent emission standards, Engine Management Systems (EMS), including port fuel injection, are now being introduced in the 4-stroke motorcycle marketplace. These systems have been generally derived from the automotive industry, albeit with some significant changes to satisfy the strict cost and packaging constraints of the motorcycle applications. Direct injection (DI) is positioned to become

Geoffrey Cathcart; Rodney Houston; Steven Ahern

122

Determination of hydrodynamic diameter of small flocs by means of direct movie analysis of Brownian motion  

Microsoft Academic Search

Direct movie analysis of the Brownian motion of single colloidal particles under optical microscope was carried out to determine hydrodynamic diameter. Mean squared displacements of individual particle against time interval of observation were obtained from the trace of Brownian motion. The hydrodynamic diameter is obtained via diffusion coefficient determined on the basis of Einstein relation. The validity of the applied

Y. Kusaka; Y. Adachi

2007-01-01

123

Laser desorption/ionization mass spectrometry for direct profiling and imaging of small molecules from raw biological materials  

SciTech Connect

Matrix-assisted laser desorption/ionization(MALDI) mass spectrometry(MS) has been widely used for analysis of biological molecules, especially macromolecules such as proteins. However, MALDI MS has a problem in small molecule (less than 1 kDa) analysis because of the signal saturation by organic matrixes in the low mass region. In imaging MS (IMS), inhomogeneous surface formation due to the co-crystallization process by organic MALDI matrixes limits the spatial resolution of the mass spectral image. Therefore, to make laser desorption/ionization (LDI) MS more suitable for mass spectral profiling and imaging of small molecules directly from raw biological tissues, LDI MS protocols with various alternative assisting materials were developed and applied to many biological systems of interest. Colloidal graphite was used as a matrix for IMS of small molecules for the first time and methodologies for analyses of small metabolites in rat brain tissues, fruits, and plant tissues were developed. With rat brain tissues, the signal enhancement for cerebroside species by colloidal graphite was observed and images of cerebrosides were successfully generated by IMS. In addition, separation of isobaric lipid ions was performed by imaging tandem MS. Directly from Arabidopsis flowers, flavonoids were successfully profiled and heterogeneous distribution of flavonoids in petals was observed for the first time by graphite-assisted LDI(GALDI) IMS.

Cha, Sangwon

2008-05-15

124

Stimulus characteristics within directives: effects on accuracy of task completion.  

PubMed Central

Three experiments were conducted in an outpatient setting with young children who had been referred for treatment of noncompliant behavior and who had coexisting receptive language or receptive vocabulary difficulties. Experiment 1 studied differential responding of the participants to a brief hierarchical directive analysis (least-to-most complex stimulus prompts) to identify directives that functioned as discriminative stimuli for accurate responding. Experiment 1 identified distinct patterns of accurate responding relative to manipulation of directive stimulus characteristics. Experiment 2 demonstrated that directives identified as effective or ineffective in obtaining stimulus control of accurate responding during Experiment 1 continued to control accurate responding across play activities and academic tasks. Experiment 3 probed effects of the interaction between the type of directive (effective vs. ineffective) and the reinforcement contingency (differential reinforcement for attempts vs. differential reinforcement for accurate responses) on accurate task completion and disruptive behavior. Results suggested that behavioral escalation from inaccurate responding to disruptive behavior occurred only when ineffective directives were combined with differential reinforcement for accurate task completion. The overall results are discussed in terms of developing a methodology for identifying stimulus characteristics of directives that affect accurate responding.

Richman, D M; Wacker, D P; Cooper-Brown, L J; Kayser, K; Crosland, K; Stephens, T J; Asmus, J

2001-01-01

125

Effects of pointing direction and direction predictability on event-related lateralizations of the EEG.  

PubMed

In two experiments, we investigated hemispheric electroencephalography (EEG) differences in 9(12) healthy volunteers during pointing to lateral and central targets. The questions addressed were whether horizontal pointing direction and the predictability of pointing direction modulated hemispheric differences (event-related lateralizations of the EEG = ERLs). To vary pointing direction predictability, targets were displayed either randomly at one of nine different positions on a screen (random) or at the same horizontal position in five subsequent trials (sequenced) while vertical positions varied randomly. Event-related lateralizations (ERLs) varied with pointing direction. This was true across changes in target eccentricity and pointing distance. Foci of the ERLs were in premotor and posterior parietal cortex, which might reflect the critical involvement of these areas in the control of visually guided reaching. Direction predictability reduced the parietal and premotor ERL before pointing onset, probably reflecting a lesser effort in visuomotor transformation. Predictability also added an overlying N2pc component to the early ERL after target onset and increased direction effects during movement. PMID:12381395

Berndt, Isabelle; Franz, Volker H; Bülthoff, Heinrich H; Wascher, Edmund

2002-09-01

126

Key Elements of Effective Teaching in the Direct Teaching Model.  

ERIC Educational Resources Information Center

Summaries and outlines are presented of key elements in effective teaching identified in research studies by Kounin (1970), Brophy (1973), Brophy and Evertson (1976), Stallings (1974; l975), Berliner (1979), and Good and Grouws (1979). These elements are synthesized in a direct teaching model that delineates the characteristics of effective

Bruning, Roger H.

127

Effects of directed and kinetic energy weapons on spacecraft  

Microsoft Academic Search

The characteristics of the various directed energy beams are reviewed, and their damaging effects on typical materials are examined for a wide range of energy pulse intensities and durations. Representative cases are surveyed, and charts are presented to indicate regions in which damage to spacecraft structures, particularly radiators for power plants, would be likely. The effects of kinetic energy weapons,

Fraas

1986-01-01

128

Design of Small MEMS Microphone Array Systems for Direction Finding of Outdoors Moving Vehicles  

PubMed Central

In this paper, a MEMS microphone array system scheme is proposed which implements real-time direction of arrival (DOA) estimation for moving vehicles. Wind noise is the primary source of unwanted noise on microphones outdoors. A multiple signal classification (MUSIC) algorithm is used in this paper for direction finding associated with spatial coherence to discriminate between the wind noise and the acoustic signals of a vehicle. The method is implemented in a SHARC DSP processor and the real-time estimated DOA is uploaded through Bluetooth or a UART module. Experimental results in different places show the validity of the system and the deviation is no bigger than 6° in the presence of wind noise.

Zhang, Xin; Huang, Jingchang; Song, Enliang; Liu, Huawei; Li, Baoqing; Yuan, Xiaobing

2014-01-01

129

Design of small MEMS microphone array systems for direction finding of outdoors moving vehicles.  

PubMed

In this paper, a MEMS microphone array system scheme is proposed which implements real-time direction of arrival (DOA) estimation for moving vehicles. Wind noise is the primary source of unwanted noise on microphones outdoors. A multiple signal classification (MUSIC) algorithm is used in this paper for direction finding associated with spatial coherence to discriminate between the wind noise and the acoustic signals of a vehicle. The method is implemented in a SHARC DSP processor and the real-time estimated DOA is uploaded through Bluetooth or a UART module. Experimental results in different places show the validity of the system and the deviation is no bigger than 6° in the presence of wind noise. PMID:24603636

Zhang, Xin; Huang, Jingchang; Song, Enliang; Liu, Huawei; Li, Baoqing; Yuan, Xiaobing

2014-01-01

130

Development of CNG direct injection (CNGDI) clean fuel system for extra power in small engine  

NASA Astrophysics Data System (ADS)

A new design of fuel system for CNG engine with direct injection (CNGDI) was developed for a demonstration project. The development of the fuel system was done on the engine with cylinder head modifications, for fuel injector and spark plug openings included in the new cylinder head. The piston was also redesigned for higher compression ratio. The fuel rails and the regulators are also designed for the direct injection system operating at higher pressure about 2.0 MPa. The control of the injection timing for the direct injectors are also controlled by the Electronic Control Unit specially designed for DI by another group project. The injectors are selected after testing with the various injection pressures and spray angles. For the best performance of the high-pressure system, selection is made from the tests on single cylinder research engine (SCRE). The components in the fuel system have to be of higher quality and complied with codes and standards to secure the safety of engine for high-pressure operation. The results of the CNGDI have shown that better power output is produced and better emissions were achieved compared to the aspirated CNG engine.

Ali, Yusoff; Shamsudeen, Azhari; Abdullah, Shahrir; Mahmood, Wan Mohd Faizal Wan

2012-06-01

131

Simulation of the direct production of 99mTc at a small cyclotron  

NASA Astrophysics Data System (ADS)

Usually 99mTc is produced indirectly through generator 99Mo/99mTc. In the present study, the direct production of this radioisotope by charged particle irradiation was investigated using Monte Carlo method. After scouting of the reactions that produce 99mTc, excitation functions of these reactions were predicted by optical model components in the TALYS-1.6 code. Suitable energy range of projectile for this production was selected by spotting of maximum cross section and minimum impurity due to other emission channels. Then target geometry was designed based on stopping power calculation by the SRIM code. Thick target yield of 100Mo(p,2n)99mTc, 98Mo(p,?)99mTc and natMo(p,x)99mTc reactions was predicted by the result of excitation function and stopping power calculations. Finally, 100Mo(p,2n)99mTc reaction was selected as a primary reaction for the direct production of 99mTc and its process was simulated by employing the MCNPX code to calculate the energy distribution of proton in the 100Mo target body and estimation of residual nuclei during irradiation. Good agreement was obtained between the experimental, the theoretical, and the simulation-based (analytical and directly) production yields. This study demonstrated that Monte Carlo provides a method for the design and optimization of targets for the radionuclide production purposes.

Eslami, M.; Kakavand, T.

2014-06-01

132

Health and environmental effects profile for Direct Blue 6  

SciTech Connect

The Health and Environmental Effects Profile for Direct Blue 6 was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human-health, aquatic-life and environmental effects of hazardous-waste constituents. Direct Blue 6 has been evaluated as a carcinogen. The human carcinogen potency factor (q1*) for Direct Blue 6 is 8.1 (mg/kg/day) for oral exposure. The Reportable Quantity (RQ) value for Direct Blue 6 is 100.

Not Available

1987-01-01

133

Early season spring small grains direct proportion estimation - Development and evaluation of a Landsat based methodology  

NASA Technical Reports Server (NTRS)

The Inventory Technology Development (ITD) project of the Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing (AgRISTARS) program has developed an accurate, automated technology for early season estimation of spring small grains areal proportion from Landsat MSS data. The design criteria for an early season procedure included estimates available within the first 30 days of the growing season, low data processing/preprocessing requirements and no need for scene-to-scene registration. The prototype estimator which meets the design goals is based on a constrained linear model in which the observed spectral response of an entire scene is modeled as a linear combination of the major constituent elements in the scene. The procedure was evaluated over 100 sample segments collected for crop years 1976 through 1979 in the U.S. Northern Great Plains. Analysis of the test results indicated accuracy that compare favorably with both the automated at-harvest technologies tested during the FY81-82 AgRISTARS Spring Small Grains Pilot experiments and earlier analyst-intensive at-harvest technologies.

Phinney, D. E.; Trichel, M. C.

1983-01-01

134

Small RNA-directed transcriptional control: new insights into mechanisms and therapeutic applications.  

PubMed

The discovery of RNA interference (RNAi) has opened new avenues in biology and medicine. In addition to post-transcriptional gene silencing, new findings are expanding the range of action of small duplex RNAs and broadening the spectrum of the potential applications of RNAi-based therapeutics. In recent years a complex and heterogeneous network of non-protein coding RNAs (ncRNAs) with potential regulatory functions has come into the spotlight providing an unexpected perspective on the mechanisms of transcriptional and epigenetic control of gene expression in human cells. The spread and complexity of these RNA-based transcriptional regulatory networks are still to be explored. However, they are likely to be important mechanisms controlling gene expression in human cells. As we will learn more about these processes, endogenous small RNAs and ncRNAs participating in these transcriptional regulatory networks might become valuable targets to modulate expression of genes involved in human diseases. Thus, understanding these basic processes of gene regulation might be translated in the near future into innovative therapeutic strategies to treat human diseases. PMID:20519954

Pastori, Chiara; Magistri, Marco; Napoli, Sara; Carbone, Giuseppina M; Catapano, Carlo V

2010-06-15

135

Effects on rapid cooling of small samples in quenching.  

PubMed

Rapid cooling of small samples is necessary both to cryofixation for electron microscopy and to vitrification for cryopreservation. Several effects on the cooling rates of small samples quenched into liquid nitrogen were studied, including the diameter of samples, the subcooling of liquid nitrogen, the quenching speed, and the quenching distance. The heat flux is 1.4 x 10(6) W/m2; the cooling rate is also up to 8200 K/s at the CHF point of boiling curves for sphere of diameter 0.287 mm quenching into subcooled liquid nitrogen. It is also found that if the time of sample moving inside the liquid nitrogen is not longer than the time required for forming stable vapor in the liquid, the quenching boiling heat transfer is not influenced by the quenching speed. Several equation for calculating heat flux of samples are also presented. PMID:9988670

Cao, Q; Hua, T C

1998-09-11

136

Measurement of illite particle thickness using a direct Fourier transform of small-angle X-ray scattering data  

USGS Publications Warehouse

It has been suggested that interstratified illite-smectite (I-S) minerals are composed of aggregates of fundamental particles. Many attempts have been made to measure the thickness of such fundamental particles, but each of the methods used suffers from its own limitations and uncertainties. Small-angle X-ray scattering (SAXS) can be used to measure the thickness of particles that scatter X-rays coherently. We used SAXS to study suspensions of Na-rectorite and other illites with varying proportions of smectite. The scattering intensity (I) was recorded as a function of the scattering vector, q = (4 ??/??) sin(??/2), where ?? is the X-ray wavelength and ?? is the scattering angle. The experimental data were treated with a direct Fourier transform to obtain the pair distance distribution function (PDDF) that was then used to determine the thickness of illite particles. The Guinier and Porod extrapolation were used to obtain the scattering intensity beyond the experimental q, and the effects of such extrapolations on the PDDF were examined. The thickness of independent rectorite particles (used as a reference mineral) is 18.3 A??. The SAXS results are compared with those obtained by X-ray diffraction peak broadening methods. It was found that the power-law exponent (??) obtained by fitting the data in the region of q = 0.1 -0.6 nm-1 to the power law (I = Ioq-??) is a linear function of illite particle thickness. Therefore, illite particle thickness could be predicted by the linear relationship as long as the thickness is within the limit where ?? <4.0.

Shang, C.; Rice, J. A.; Eberl, D. D.; Lin, J. -S.

2003-01-01

137

Towards Small-Sized Long Tail Business with the Dual-Directed Recommendation System  

NASA Astrophysics Data System (ADS)

This paper describes a novel architecture to promote retail businesses using information recommendation systems. The main features of the architecture are 1) Dual-directed Recommendation system, 2) Portal site for three kinds of users: Producers, Retailers, and Consumers, which are considered to be Prosumers, and 3) Agent-based implementation. We have developed a web-based system DAIKOC (Dynamic Advisor for Information and Knowledge Oriented Communities) with the above architecture. In this paper, we focus on the recommendation functions to extract the items that will achieve the large sales in the future from the ID (IDentification)-POS (Point-Of-Sales) data.

Takahashi, Masakazu; Yamada, Takashi; Tsuda, Kazuhiko; Terano, Takao

138

Direct current electrical potential measurement of the growth of small cracks  

NASA Technical Reports Server (NTRS)

The analytical and experimental aspects of the direct-current electrical potential difference (dcEPD) method for continuous monitoring of the growth kinetics of short (50 to 500 microns) fatigue cracks are reviewed, and successful applications of the deEPD method to study fatigue crack propagation in a variety of metallic alloys exposed to various environments are described. Particular attention is given to the principle of the dcEPD method, the analytical electrical potential calibration relationships, and the experimental procedures and equipment.

Gangloff, Richard P.; Slavik, Donald C.; Piascik, Robert S.; Van Stone, Robert H.

1992-01-01

139

Design and fabrication of pumpless small direct methanol fuel cells for portable applications  

NASA Astrophysics Data System (ADS)

This work studied the design, fabrication, and performance evaluation of a 36 cm 2, passive, air-breathing, room-temperature, direct methanol fuel cell (DMFC). The cell is completely passive with no external pumps or other ancillary devices. It takes oxygen from the surrounding air, and the methanol solution is stored in a built-in reservoir. The fuel cell runs successfully with methanol concentration ranging from 0.5 to 4 M. It produced a power density of 11 mW cm -2 reached with 4 M methanol at current densities as high as 36 mA cm -2 and at a voltage of 0.3.

Shimizu, Takahiro; Momma, Toshiyuki; Mohamedi, Mohamed; Osaka, Tetsuya; Sarangapani, Srinivasan

140

Improving image contrast for the direct detection of exoplanets at small inner working angles  

NASA Astrophysics Data System (ADS)

The detection of extrasolar planets, using both space- and ground-based telescopes, is one of the most exciting fields in astronomy today, with the ultimate goal of the direct direction of earth-like planets in the habitable zone. It is with this vision that the explorer mission EXCEDE selected by NASA for technology development, is designed. EXCEDE (Exoplanetary Circumstellar Environment and Disk Explorer) is composed of a 0.7 m telescope equipped with a Phase-Induced Amplitude Apodization Coronagraph (PIAA-C) and a 2000-element MEMS deformable mirror, capable of raw contrasts of 10-6 at 1.2 ?/D and 10-7 above 2 ?/D. Obtaining these contrasts requires precise wavefront control algorithms used in conjuncture with deformable mirrors. Unlike other optical systems, where the goal is to obtain the best wavefront, we aim at canceling the diffracted light coming from the parent star in a specific region to increase signal-to-noise of the planet. To do so, we use wavefront control techniques, such as Electric Field Conjugation (EFC) and speckle nulling, already developed and soon to be operational on 8-m class telescopes. One caveat is that the demonstration was done at moderate separations (r> 3?/D).In this paper, we present tricks and techniques to perform high-contrast imaging at 1.2 ?/d using the NASA Ames Coronagraph Experiment testbed.

Thomas, Sandrine; Pluzhnik, Eugene; Lozi, Julien; Belikov, Rusland; Witteborn, Fred; Greene, Thomas; Schneider, Glenn; Guyon, Olivier

2013-09-01

141

Analytical fuel property effects: Small combustors, phase 2  

NASA Technical Reports Server (NTRS)

The effects of non-standard aviation fuels on a typical small gas turbine combustor were studied and the effectiveness of design changes intended to counter the effects of these fuels was evaluated. The T700/CT7 turboprop engine family was chosen as being representative of the class of aircraft power plants desired for this study. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. No. 2 diesel fuel was also evaluated in this program. Results demonstrated the anticipated higher than normal smoke output and flame radiation intensity with resulting increased metal temperatures on the baseline T700 combustor. Three new designs were evaluated using the non standard fuels. The three designs incorporated enhanced cooling features and smoke reduction features. All three designs, when burning the broad specification fuels, exhibited metal temperatures at or below the baseline combustor temperatures on JP-5. Smoke levels were acceptable but higher than predicted.

Hill, T. G.; Monty, J. D.; Morton, H. L.

1985-01-01

142

Small-scale clad-effects study. [PWR; BWR  

SciTech Connect

The Small-Scale Clad Effects Study of the HSST Program was initiated to study the interaction of stainless cladding with flaws initiated in and propagating in base metal. From the designer's viewpoint stainless cladding is primarily viewed as a corrosion- and crud-prevention measure in light-water reactor vessel design, and except for its effect upon fatigue in thermal transients, its effect upon structural integrity has heretofore been largely disregarded. With the more recent focus of safety studies upon LOCA scenarios that emphasize the behavior of small flaws, it has become evident that stainless cladding may have a key role in the propagation and/or arrest of propagating flaws. A complicating factor in understanding the role of stainless cladding in this setting is its fracture toughness as a function of radiation dose and as a function of fabrication process for which meager data exist. The initial phase of this study has attempted to address this question by testing stainless-clad specimens that had been subjected to heat treatments to simulate beginning-of-life and end-of-life toughness conditions to fast-running cracks.

Robinson, G.C.

1982-01-01

143

Extraction of Network Topology From Multi-Electrode Recordings: Is there a Small-World Effect?  

PubMed Central

The simultaneous recording of the activity of many neurons poses challenges for multivariate data analysis. Here, we propose a general scheme of reconstruction of the functional network from spike train recordings. Effective, causal interactions are estimated by fitting generalized linear models on the neural responses, incorporating effects of the neurons’ self-history, of input from other neurons in the recorded network and of modulation by an external stimulus. The coupling terms arising from synaptic input can be transformed by thresholding into a binary connectivity matrix which is directed. Each link between two neurons represents a causal influence from one neuron to the other, given the observation of all other neurons from the population. The resulting graph is analyzed with respect to small-world and scale-free properties using quantitative measures for directed networks. Such graph-theoretic analyses have been performed on many complex dynamic networks, including the connectivity structure between different brain areas. Only few studies have attempted to look at the structure of cortical neural networks on the level of individual neurons. Here, using multi-electrode recordings from the visual system of the awake monkey, we find that cortical networks lack scale-free behavior, but show a small, but significant small-world structure. Assuming a simple distance-dependent probabilistic wiring between neurons, we find that this connectivity structure can account for all of the networks’ observed small-world ness. Moreover, for multi-electrode recordings the sampling of neurons is not uniform across the population. We show that the small-world-ness obtained by such a localized sub-sampling overestimates the strength of the true small-world structure of the network. This bias is likely to be present in all previous experiments based on multi-electrode recordings.

Gerhard, Felipe; Pipa, Gordon; Lima, Bruss; Neuenschwander, Sergio; Gerstner, Wulfram

2011-01-01

144

Potent Host-Directed Small-Molecule Inhibitors of Myxovirus RNA-Dependent RNA-Polymerases  

PubMed Central

Therapeutic targeting of host cell factors required for virus replication rather than of pathogen components opens new perspectives to counteract virus infections. Anticipated advantages of this approach include a heightened barrier against the development of viral resistance and a broadened pathogen target spectrum. Myxoviruses are predominantly associated with acute disease and thus are particularly attractive for this approach since treatment time can be kept limited. To identify inhibitor candidates, we have analyzed hit compounds that emerged from a large-scale high-throughput screen for their ability to block replication of members of both the orthomyxovirus and paramyxovirus families. This has returned a compound class with broad anti-viral activity including potent inhibition of different influenza virus and paramyxovirus strains. After hit-to-lead chemistry, inhibitory concentrations are in the nanomolar range in the context of immortalized cell lines and human PBMCs. The compound shows high metabolic stability when exposed to human S-9 hepatocyte subcellular fractions. Antiviral activity is host-cell species specific and most pronounced in cells of higher mammalian origin, supporting a host-cell target. While the compound induces a temporary cell cycle arrest, host mRNA and protein biosynthesis are largely unaffected and treated cells maintain full metabolic activity. Viral replication is blocked at a post-entry step and resembles the inhibition profile of a known inhibitor of viral RNA-dependent RNA-polymerase (RdRp) activity. Direct assessment of RdRp activity in the presence of the reagent reveals strong inhibition both in the context of viral infection and in reporter-based minireplicon assays. In toto, we have identified a compound class with broad viral target range that blocks host factors required for viral RdRp activity. Viral adaptation attempts did not induce resistance after prolonged exposure, in contrast to rapid adaptation to a pathogen-directed inhibitor of RdRp activity.

Krumm, Stefanie A.; Ndungu, J. Maina; Yoon, Jeong-Joong; Dochow, Melanie; Sun, Aiming; Natchus, Michael; Snyder, James P.; Plemper, Richard K.

2011-01-01

145

Relative Importance of Direct and Indirect Effects of Starvation for Young Walleyes  

Microsoft Academic Search

Starvation can directly affect energy levels and mortality rates in fish and may have indirect influences on behaviors essential to survival. We examined physiological and behavioral effects of food deprivation for larval (8–24 mm) and juvenile (small, 45–70 mm; medium, 80–120 mm; and large, 140–230 mm) walleyes Stizostedion vitreum encompassing critical periods in their early life history. Juvenile walleye size

Jory L. Jonas; David H. Wahl

1998-01-01

146

Effective dose from direct and indirect digital panoramic units  

PubMed Central

Purpose This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. Materials and Methods Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations. Results The effective doses of the 4 digital panoramic units ranged between 8.9 µSv and 37.8 µSv. By using the head phantom, the effective doses from the direct digital panoramic units (37.8 µSv, 27.6 µSv) were higher than those from the indirect units (8.9 µSv, 15.9 µSv). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp. Conclusion To reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom.

Lee, Gun-Sun; Kim, Jin-Soo; Seo, Yo-Seob

2013-01-01

147

Picture surface illusion: small effects on a major axis.  

PubMed

Perception of 2-D ellipses on a picture surface is inaccurate-if the ellipses depict circles that are tilted in 3-D, receding from the viewer (Hammad, Kennedy, Juricevic, & Rajani, 2008a, Perception, 37, 504-510). Notably, the minor axis of the ellipse is seen as larger than is true. This illusory effect could be due to the simultaneous presence of optical information for the 2-D ellipse and optical information for the 3-D tilted circle. The optical information for the circle may bias vision's use of the optical information for the ellipse. This theory predicts that illusory effects should occur on the major axis as well as the minor axis; but, we argue, the major axis effect should be smaller than the minor axis effect. We confirm the prediction. Observers looked at target ellipses depicting tops of tilted cylinders. In one experiment observers chose a match for the target from choice sets of seven 2-D ellipses. In the second, observers used the method of adjustment. Both axes were overestimated, the minor axis more than the major, as the theory suggested. We point out that the relative size of the effects matters to the theory, and so the small effect counts for a lot. PMID:24689129

Mastandrea, Stefano; Kennedy, John M; Wnuczko, Marta

2014-01-01

148

Health and environmental effects profile for Direct Brown 95  

SciTech Connect

The Health and Environmental Effects Profile for Direct Brown 95 was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human-health, aquatic-life and environmental effects of hazardous-waste constituents. The human carcinogen potency factor (q1*) for Direct Brown 95 is 9.3 (mg/kg/day) for oral exposure. The Reportable Quantity (RQ) value for Direct Brown 95 is 100.

Not Available

1987-03-01

149

Pilot opinions of sampling effects in lateral-directional control  

NASA Technical Reports Server (NTRS)

Flight experiments with a microprocessor control system were conducted to determine the effects of variations in sampling parameters on several pilots' opinions of lateral-directional flying qualities. Princeton's variable-response research aircraft (VRA), which is equipped with a microprocessor based digital flight control system (Micro-DFCS), was the test vehicle. Two U.S. Navy pilots evaluated the effects of sampling rate, quantization, and pure time delay during tracking, approach, and landing. Aircraft carrier approach tasks were conducted using a Navy approach mirror. Acquisition and tracking of fixed objects on the ground provided additional information related to the Navy misson. The longitudinal controls were implemented with analog electronics, while the lateral-directional pilot inputs (stick and rudder) were fed to the Micro-DFCS, which commanded the ailerons and rudder. The conceptual relationship between the evaluation pilot's lateral-directional inputs, the flight computer, and the aircraft are illustrated.

Stengel, R. F.; Miller, G. E.

1982-01-01

150

Small signal stability analysis and control of the wind turbine with the direct-drive permanent magnet generator integrated to the grid  

Microsoft Academic Search

In this paper, a model of the wind turbine (WT) with direct-drive permanent magnet generator (DDPMG) and its associated controllers is presented, based on which a small signal stability analysis model is derived. The small signal stability analysis shows that the WT with DDPMG without the controllers is stable, and the controller can improve the small signal stability of the

F. Wu; Xiao-Ping Zhang; P. Ju

2009-01-01

151

Small Molecule-directed Immunotherapy against Recurrent Infection by Mycobacterium tuberculosis*  

PubMed Central

Tuberculosis remains the biggest infectious threat to humanity with one-third of the population infected and 1.4 million deaths and 8.7 million new cases annually. Current tuberculosis therapy is lengthy and consists of multiple antimicrobials, which causes poor compliance and high treatment dropout, resulting in the development of drug-resistant variants of tuberculosis. Therefore, alternate methods to treat tuberculosis are urgently needed. Mycobacterium tuberculosis evades host immune responses by inducing T helper (Th)2 and regulatory T (Treg) cell responses, which diminish protective Th1 responses. Here, we show that animals (Stat-6?/?CD4-TGF?RIIDN mice) that are unable to generate both Th2 cells and Tregs are highly resistant to M. tuberculosis infection. Furthermore, simultaneous inhibition of these two subsets of Th cells by therapeutic compounds dramatically reduced bacterial burden in different organs. This treatment was associated with the generation of protective Th1 immune responses. As these therapeutic agents are not directed to the harbored organisms, they should avoid the risk of promoting the development of drug-resistant M. tuberculosis variants.

Bhattacharya, Debapriya; Dwivedi, Ved Prakash; Maiga, Mamoudou; Maiga, Mariama; Van Kaer, Luc; Bishai, William R.; Das, Gobardhan

2014-01-01

152

New multi-target-directed small molecules against Alzheimer's disease: a combination of resveratrol and clioquinol.  

PubMed

Alzheimer's disease (AD) is currently one of the most difficult and challenging diseases to treat. Based on the 'multi-target-directed ligands' (MTDLs) strategy, we designed and synthesised a series of new compounds against AD by combining the pharmacophores of resveratrol and clioquinol. The results of biological activity tests showed that the hybrids exhibited excellent MTDL properties: a significant ability to inhibit self-induced ?-amyloid (A?) aggregation and copper(ii)-induced A? aggregation, potential antioxidant behaviour (ORAC-FL value of 0.9-3.2 Trolox equivalents) and biometal chelation. Among these compounds, (E)-5-(4-hydroxystyryl)quinoline-8-ol () showed the most potent ability to inhibit self-induced A? aggregation (IC50 = 8.50 ?M) and copper(ii)-induced A? aggregation and to disassemble the well-structured A? fibrils generated by self- and copper(ii)-induced A? aggregation. Note that could also control Cu(i/ii)-triggered hydroxyl radical (OH?) production by halting copper redox cycling via metal complexation, as confirmed by a Cu-ascorbate redox system assay. Importantly, did not show acute toxicity in mice at doses of up to 2000 mg kg(-1) and was able to cross the blood-brain barrier (BBB), according to a parallel artificial membrane permeation assay. These results indicate that compound is a promising multifunctional compound for the development of novel drugs for AD. PMID:24986600

Mao, Fei; Yan, Jun; Li, Jianheng; Jia, Xian; Miao, Hui; Sun, Yang; Huang, Ling; Li, Xingshu

2014-07-16

153

Direct observation of small cluster mobility and ripening. [during annealing of metal films on amorphous substrates  

NASA Technical Reports Server (NTRS)

Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single crystalline thin graphite substrates were studied by in-situ transmission electron microscopy (TEM) under controlled environmental conditions (residual gas pressure of 10 to the minus 9th power torr) in the temperature range from 25 to 450 C. Sputter cleaning of the substrate surface, metal deposition, and annealing were monitored by TEM observation. Pseudostereographic presentation of micrographs in different annealing stages, the observation of the annealing behavior at cast shadow edges, and measurements with an electronic image analyzing system were employed to aid the visual perception and the analysis of changes in deposit structure recorded during annealing. Slow Ostwald ripening was found to occur in the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility.

Heinemann, K.; Poppa, H.

1975-01-01

154

Synthesis of stable ultra-small Cu nanoparticles for direct writing flexible electronics  

NASA Astrophysics Data System (ADS)

In this study, pure Cu nanoparticles (NPs) have been successfully synthesized and the Cu nano-ink was prepared for direct writing on photo paper using a roller pen. The tri-sodium citrate was used as initial reducing-cum-surfactant agent followed by hydrazine as a second massive reducing agent and cetyltrimethylammonium bromide (CTAB) as extra surfactant agent. From the XRD, TEM, and HR-TEM analyses, the synthesized particles are confirmed to be Cu in spherical shape with sizes range of 2.5 ± 1.0 nm. By analyzing the FT-IR spectroscopy and TGA curves, it was found that the obtained particles capped with tri-sodium citrate and CTAB layers are stable to oxidation up to the temperature 228 °C. The reduced size and enhanced air-stability of the Cu NPs result in an improved particle density upon sintering, which is mainly responsible for the increased conductivity of the Cu patterns. The resistivity of Cu patterns sintered in Ar at 160 °C for 2 h is 7.2 ± 0.6 ?? cm, which is 4.40 times the bulk Cu resistivity. The drawn Cu lines exhibited excellent integrity and good conductivity, which were experimentally tested. Moreover, a Cu electrode and a sample RFID antenna were successfully made.

Li, Wei; Chen, Minfang

2014-01-01

155

Allosteric Communication in Myosin V: From Small Conformational Changes to Large Directed Movements  

PubMed Central

The rigor to post-rigor transition in myosin, a consequence of ATP binding, plays an essential role in the Lymn–Taylor functional cycle because it results in the dissociation of the actomyosin complex after the powerstroke. On the basis of the X-ray structures of myosin V, we have developed a new normal mode superposition model for the transition path between the two states. Rigid-body motions of the various subdomains and specific residues at the subdomain interfaces are key elements in the transition. The allosteric communication between the nucleotide binding site and the U50/L50 cleft is shown to result from local changes due to ATP binding, which induce large amplitude motions that are encoded in the structure of the protein. The triggering event is the change in the interaction of switch I and the P-loop, which is stabilized by ATP binding. The motion of switch I, which is a relatively rigid element of the U50 subdomain, leads directly to a partial opening of the U50/L50 cleft; the latter is expected to weaken the binding of myosin to actin. The calculated transition path demonstrates the nature of the subdomain coupling and offers an explanation for the mutual exclusion of ATP and actin binding. The mechanism of the uncoupling of the converter from the motor head, an essential part of the transition, is elucidated. The origin of the partial untwisting of the central ?-sheet in the rigor to post-rigor transition is described.

Cecchini, M.; Houdusse, A.; Karplus, M.

2008-01-01

156

Strain induced directional coarsening in nickel based superalloys: Investigation on kinetics using the small angle neutron scattering (SANS) technique  

SciTech Connect

Using the small angle neutron scattering technique, the authors have observed rafting in nickel based single crystal superalloys. Kinetics of morphological evolution of the precipitates have been studied in situ. Therefore the authors used a special furnace designed for the ageing of prestrained specimens under a neutron beam. The evolution of both the precipitate aspect ratio and the distance between precipitates confirms the importance of strain in the directional coarsening process. Results are presented and discussed regarding kinetics and microstructural aspects. In such conditions, rafts seem to be different from those obtained after a creep test.

Veron, M.; Bastie, P. [UMR CNRS, Saint Martin d`Heres (France)] [UMR CNRS, Saint Martin d`Heres (France)

1997-08-01

157

Direct and Extended Vocabulary Instruction in Kindergarten: Investigating Transfer Effects  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the efficacy of an 18-week program of direct and extended vocabulary instruction with kindergarten students on both proximal measures of target word knowledge and transfer measures of generalized language and literacy. A second purpose was to examine whether treatment effects would be moderated by…

Coyne, Michael D.; McCoach, D. Betsy; Loftus, Susan; Zipoli, Richard, Jr.; Ruby, Maureen; Crevecoeur, Yvel C.; Kapp, Sharon

2010-01-01

158

Direct and Extended Vocabulary Instruction in Kindergarten: Investigating Transfer Effects  

Microsoft Academic Search

The purpose of this study was to investigate the efficacy of an 18-week program of direct and extended vocabulary instruction with kindergarten students on both proximal measures of target word knowledge and transfer measures of generalized language and literacy. A second purpose was to examine whether treatment effects would be moderated by initial receptive vocabulary knowledge measured at pretest. In

Michael D. Coyne; D. Betsy McCoach; Susan Loftus; Richard Zipoli Jr; Maureen Ruby; Yvel C. Crevecoeur; Sharon Kapp

2010-01-01

159

Direct and Indirect Effects of Online Learning on Distance Education  

ERIC Educational Resources Information Center

This paper presents an exploratory study that investigates the effects of online learning on distance education students in an open university context. Two hypotheses are posited: (1) a direct relationship exists between students involvement in online learning and distance learning outcomes, and (2) an indirect relationship exists between these…

Shin, Namin; Chan, Jason K. Y.

2004-01-01

160

Direct and indirect effects of online learning on distance education  

Microsoft Academic Search

This paper presents an exploratory study that investigates the effects of online learning on distance education students in an open university context. Two hypotheses are posited: (1) a direct relationship exists between students' involvement in online learning and distance learning outcomes, and (2) an indirect relationship exists between these two domains via the mediating vari- able of an institutional Transactional

Namin Shin; Jason K. Y. Chan

2004-01-01

161

Direct Antidiabetic Effect of Leptin through Triglyceride Depletion of Tissues  

Microsoft Academic Search

Leptin is currently believed to control body composition largely, if not entirely, via hypothalamic receptors that regulate food intake and thermogenesis. Here we demonstrate direct extraneural effects of leptin to deplete fat content of both adipocytes and nonadipocytes to levels far below those of pairfed controls. In cultured pancreatic islets, leptin lowered triglyceride (TG) content by preventing TG formation from

Michio Shimabukuro; Kazunori Koyama; Guoxun Chen; May-Yun Wang; Falguni Trieu; Young Lee; Christopher B. Newgard; Roger H. Unger

1997-01-01

162

Effect-Directed Analysis of Mutagens in Ambient Airborne Particles  

Microsoft Academic Search

\\u000a This chapter reviews the major advances and challenges in effect-directed analysis (EDA) of mutagenic chemicals in ambient\\u000a airborne particles. Mutagens are chemicals that can cause mutations – inheritable changes in the genetic code that can give\\u000a rise to adverse health effects. The majority of studies dealing with EDA of mutagens in airborne particles combine liquid\\u000a chromatographic fractionation of particle extracts

John L. Durant; Arthur L. Lafleur

163

Analytical methods in environmental effects-directed investigations of effluents.  

PubMed

Effluent discharges are released into aquatic environments as complex mixtures for which there is commonly either no knowledge of the toxic components or a lack of understanding of how known toxicants interact with other effluent components. Effects-directed investigations consist of chemical extraction and iterative fractionation steps directed by a biological endpoint that is designed to permit the identification or characterization of the chemical classes or compounds in a complex mixture responsible for the observed biological activity. Our review of the literature on effects-directed analyses of effluents for non-mutagenic as well as mutagenic endpoints showed that common extraction and concentration methods have been used. Since the mid-1980s, the methods have evolved from the use of XAD resins to C18 solid-phase extraction (SPE). Blue cotton, blue rayon, and blue chitin have been used specifically for investigations of mutagenic activity where polycyclic compounds were involved or suspected. After isolation, subsequent fractionations have been accomplished using SPE or a high-pressure liquid chromatography (HPLC) system commonly fitted with a C18 reverse-phase column. Substances in active fractions are characterized by gas chromatography/mass spectrometry (GC-MS) and/or other spectrometric techniques for identification. LC-MS methods have been developed for difficult-to-analyze polar substances identified from effects-directed studies, but the potential for LC-MS to identify unknown polar compounds has yet to be fully realized. Salmonella-based assays (some miniaturized) have been coupled with fractionation methods for most studies aimed at identifying mutagenic fractions and chemical classes in mixtures. Effects-directed investigations of mutagens have focused mostly on drinking water and sewage, whereas extensive investigations of non-mutagenic effects have also included runoff, pesticides, and pulp mill effluents. The success of effects-directed investigations should be based on a realistic initial objective of each project. Identification of chemical classes associated with the measured biological endpoint is frequently achievable; however, confirmation of individual compounds is much more difficult and not always a necessary goal of effects-directed chemical analysis. PMID:15878143

Hewitt, L Mark; Marvin, Chris H

2005-05-01

164

Design and Experimental Study for Development of Pb-Bi Cooled Direct Contact Boiling Water Small Fast Reactor (PBWFR)  

SciTech Connect

A design concept of Pb-Bi cooled direct contact boiling water small fast reactor (PBWFR) has been formulated with some design parameters identified. In the PBWFR, water is injected into hot Pb-Bi above the core, and direct contact boiling takes place in the chimney. The boiling two-phase flow in the chimney serves as a steam lift pump and a steam generator. A two-region core is designed. A decrease in reactivity was estimated to be 1.5 % dk/kk' for 15 years. A fuel assembly has 271 fuel rods with 12.0 mm in diameter and 15.9 mm in pitch in a hexagonal wrapper tube. The chimney, cyclone separators and chevron dryers, direct heat exchangers (DHX), reactor vessel air cooling systems (RVACS) and guard vessel are designed. For the technical development of the PBWFR, experimental and analytical studies are performed for Pb-Bi direct contact boiling two-phase flow, steel corrosion in Pb-Bi flow, oxygen control and oxygen sensor, and removal of polonium contamination. (authors)

Takahashi, M.; Obara, T.; Iguchi, T.; Otsubo, A.; Kondo, M.; Qi, Y.; Matsumoto, M.; Yusibani, E.; Akashi, T.; Yamada, A.; Nei, H. [Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, N1-18 2-12-1, O-okayama, Meguro-ku, Tokyo, 152-8550 (Japan); Hata, K.; Hara, K. [Nuclear Development Corporation, 622-12 Funaishikawa, Tokai-mura, Naka-gun, Ibaraki (Japan); Uchida, S.; Osada, H.; Kasahara, Y.; Matsuzawa, K.; Sawa, N.; Yamada, Y.; Kurome, K.; Okubo, Y. [Advanced Reactor Technology Co., Ltd., 2-16-5 Kohnan, Minatoku, Tokyo (Japan)

2004-07-01

165

A small-molecule modulator interacts directly with deltaPhe508-CFTR to modify its ATPase activity and conformational stability.  

PubMed

The deletion of Phe-508 (DeltaPhe508) constitutes the most prevalent of a number of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) that cause cystic fibrosis (CF). This mutation leads to CFTR misfolding and retention in the endoplasmic reticulum, as well as impaired channel activity. The biosynthetic defect can be partially overcome by small-molecule "correctors"; once at the cell surface, small-molecule "potentiators" enhance the channel activity of DeltaPhe508-CFTR. Certain compounds, such as VRT-532, exhibit both corrector and potentiator functions. In the current studies, we confirmed that the inherent chloride channel activity of DeltaPhe508-CFTR (after biosynthetic rescue) is potentiated in studies of intact cells and membrane vesicles. It is noteworthy that we showed that the ATPase activity of the purified and reconstituted mutant protein is directly modulated by binding of VRT-532 [4-methyl-2-(5-phenyl-1H-pyrazol-3-yl)-phenol] ATP turnover by reconstituted DeltaPhe508-CFTR is decreased by VRT-532 treatment, an effect that may account for the increase in channel open time induced by this compound. To determine whether the modification of DeltaPhe508-CFTR function caused by direct VRT-532 binding is associated with structural changes, we evaluated the effect of VRT-532 binding on the protease susceptibility of the major mutant. We found that binding of VRT-532 to DeltaPhe508-CFTR led to a minor but significant decrease in the trypsin susceptibility of the full-length mutant protein and a fragment encompassing the second half of the protein. These findings suggest that direct binding of this small molecule induces and/or stabilizes a structure that promotes the channel open state and may underlie its efficacy as a corrector of DeltaPhe508-CFTR. PMID:19339490

Wellhauser, Leigh; Kim Chiaw, Patrick; Pasyk, Stan; Li, Canhui; Ramjeesingh, Mohabir; Bear, Christine E

2009-06-01

166

Effects of RF absorbers on measurements of small antennas in small anechoic chambers  

Microsoft Academic Search

In this work, the influence of resistive absorbers in the vicinity of small antennas was investigated, in order to define a lower limit for the size of a small anechoic chamber for antenna calibration and radiation pattern measurements, with respect to the distance between the antenna under test (AUT) and the RF absorbers lining the walls. Furthermore, the influence of

C. Icheln; J. Ollikainen; P. Vainikainen

2001-01-01

167

Aerosol direct radiative effect over China estimated with visibility measurements  

NASA Astrophysics Data System (ADS)

As a short-lived climate forcer, aerosols exhibit strong radiative effects that vary significantly across the space and time. Current understanding of the long-term variability of aerosol climate forcings is however very poor due to lack of relevant atmospheric measurements. Historic records for visibility measurements from thousands of ground meteorological stations offer a plausible tool to study the decadal and multi-decadal variability of aerosol radiative effects. As a first step, this study presents a method to estimate aerosol direct radiative effect over China based on visibility data for 2006. Visibility data from about 400 ground stations are converted to near-surface aerosol extinction coefficients, which are converted then to aerosol optical depth (AOD) based on spatially and temporally varying vertical distributions of aerosol optical properties simulated by the widely used chemical transport model GEOS-Chem. The resulting AOD data are consistent with direct measurements from the China Aerosol Remote Sensing Network (CARSNET) and the Aerosol Robotic Network (AERONET) in regions where visibility and AOD measurement sites are close in distance. Next, the visibility-derived AOD data are combined with other aerosol optical properties adopted from GEOS-Chem, cloud data from ground stations and surface albedo data from moderate-resolution imaging spectroradiometer (MODIS) to derive the direct radiative effect, by employing the Santa Barbara DISORT Atmospheric Radiative Transfer model (SBDART). Spatial and monthly variations of aerosol radiative effects are examined.

Ye, K.; Lin, J.

2012-12-01

168

Radiation Synovectomy: an effective alternative treatment for inflamed small joints  

PubMed Central

An inflamed painful joint is one of the most common indications for the patient to be referred to a rheumatologist or an orthopedician. In relation to the aetiology, the therapeutic approach might be systemic, local or a combination of them in some cases, always with the thought of balancing risk with benefit for the patient. In all cases, independently of the cause, the goal of therapy is to improve the quality of life through the reduction of pain, improvement of mobility and preservation of function. Nuclear Medicine has to offer Radiosynoviorthesis, an effective alternative procedure for treating inflamed small joints. Various radionuclides are available for radiosynoviorthesis. Their selection depends on the size of the joint to be treated. Small joints are mainly treated with [169Er] erbium under a fluoroscopic or sonographic guidance, usually with a simultaneous instillation of a corticoid. Candidates for radiosynoviorthesis should have been under a six-month systemic treatment without encouraging results or should have undergone at least one unsuccessful intra-articular injection of a long acting glucocorticoid. Since 1973, when [169Er] erbium was firstly suggested as a therapeutic agent for radiosynoviorthesis of the finger joints, there has been quite enough experience in its' application. It has been found to be cost effective in providing long term relief of pain and deformity of the inflamed joints in comparison to other therapeutic approaches. Additionally, there is no radiation risk and can be performed on an out patient basis. Therefore it can stand as an effective alternative procedure for treating early stages of chronic synovitis in RA (rheumatoid arthritis) patients, with minor damage of the cartilage and the adjacent bones, and for synovitis secondary to inflammatory arthropathies.

Karavida, N; Notopoulos, A

2010-01-01

169

Contrasting the direct radiative effect and direct radiative forcing of aerosols  

NASA Astrophysics Data System (ADS)

The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is sometimes confused with the direct radiative forcing (DRF), which is the change in DRE from pre-industrial to present-day (not including climate feedbacks). In this study we couple a global chemical transport model (GEOS-Chem) with a radiative transfer model (RRTMG) to contrast these concepts. We estimate a global mean all-sky aerosol DRF of -0.36 Wm-2 and a DRE of -1.83 Wm-2 for 2010. Therefore, natural sources of aerosol (here including fire) affect the global energy balance over four times more than do present-day anthropogenic aerosols. If global anthropogenic emissions of aerosols and their precursors continue to decline as projected in recent scenarios due to effective pollution emission controls, the DRF will shrink (-0.22 Wm-2 for 2100). Secondary metrics, like DRE, that quantify temporal changes in both natural and anthropogenic aerosol burdens are therefore needed to quantify the total effect of aerosols on climate.

Heald, C. L.; Ridley, D. A.; Kroll, J. H.; Barrett, S. R. H.; Cady-Pereira, K. E.; Alvarado, M. J.; Holmes, C. D.

2014-06-01

170

Mass effect on rotational diffusion of small solutes in solution  

NASA Astrophysics Data System (ADS)

Rotational correlation times (?c) of two pairs of small solutes, CpM(CO)3 and M2(CO)10 (M = Mn, Re), are determined in various viscous alkane solutions by narrow-band IR pump broad-band IR probe spectroscopy. By choosing these pairs of molecules, which are significantly different in mass but almost identical in volume, shape and in their expected interactions with solvents, we isolate the effects of mass on ?c. The effect of mass was observed clearly for these pairs of solute tracers, with heavier substitutions leading to larger ?c values. In the case of the CpM(CO)3 pair, in which the moments of inertia do not change much, the effect of mass was seen in the ?c vs. solvent viscosity plot as result of larger slope for heavier substitution, with no clear change in the intercept. For the M2(CO)10 pair, in which the moments of inertia change significantly, this mass effect can be observed through changes in both the slope and intercept.

Nguyen, Son C.; Lomont, Justin P.; Harris, Charles B.

2013-08-01

171

Effects of directed and kinetic energy weapons on spacecraft  

SciTech Connect

The characteristics of the various directed energy beams are reviewed, and their damaging effects on typical materials are examined for a wide range of energy pulse intensities and durations. Representative cases are surveyed, and charts are presented to indicate regions in which damage to spacecraft structures, particularly radiators for power plants, would be likely. The effects of kinetic energy weapons, such as bird-shot, are similarly examined. The charts are then applied to evaluate the effectiveness of various measures designed to reduce the vulnerability of spacecraft components, particularly nuclear electric power plants.

Fraas, A.P.

1986-12-01

172

Ion exchange liquid chromatography method for the direct determination of small ribonucleic acids.  

PubMed

Bioanalysis of siRNAs is challenging due to their size (5-14 kDa) and negative charge across the backbone, which complicates both sample preparation and chromatography. We present here a one step sample preparation combined with non-denaturing anion exchange chromatography with UV detection for the quantitation of siRNA and its chain shortened metabolites. The sample preparation uses a novel lysis buffer with proteinase K to effectively isolate siRNA from cells and formulated media with greater than 95% recovery. The ion exchange chromatography allows for a lower limit of quantitation of 6 ng mL(-1) in cells and media equivalent to 6 ng/200,000 cells. This method is applied to study the uptake of siRNA in prostate cancer cells and the disappearance in the media and siRNA metabolism. siRNA metabolites are identified by matching the retention time of standards to metabolite peaks. Identification is further confirmed by mass spectrometry. To our knowledge this is the first ion exchange method reported for the quantitation of siRNA from a biological matrix. It is also the first non-denaturing chromatographic method reported for siRNA quantitation. PMID:24091375

McGinnis, A Cary; Cummings, Brian S; Bartlett, Michael G

2013-10-17

173

Reprogram or reboot: small molecule approaches for the production of induced pluripotent stem cells and direct cell reprogramming.  

PubMed

Stem cell transplantation is a potential therapy for regenerative medicine, which aims to restore tissues damaged by trauma, aging, and diseases. Since its conception in the late 1990s, chemical biology has provided powerful and diverse small molecule tools for modulating stem cell function. Embryonic stem cells could be an ideal source for transplantation, but ethical concerns restrict their development for cell therapy. The seminal advance of induced pluripotent stem cell (iPSC) technology provided an attractive alternative to human embryonic stem cells. However, iPSCs are not yet considered an ideal stem cell source, due to limitations associated with the reprogramming process and their potential tumorigenic behavior. This is an area of research where chemical biology has made a significant contribution to facilitate the efficient production of high quality iPSCs and elucidate the biological mechanisms governing their phenotype. In this review, we summarize these advances and discuss the latest progress in developing small molecule modulators. Moreover, we also review a new trend in stem cell research, which is the direct reprogramming of readily accessible cell types into clinically useful cells, such as neurons and cardiac cells. This is a research area where chemical biology is making a pivotal contribution and illustrates the many advantages of using small molecules in stem cell research. PMID:24245936

Jung, Da-Woon; Kim, Woong-Hee; Williams, Darren Reece

2014-01-17

174

The dark flow induced small-scale kinetic Sunyaev-Zel'dovich effect  

NASA Astrophysics Data System (ADS)

Recently, Kashlinsky et al. reported a discovery of a ~103kms-1 bulk flow of the Universe out to z ~= 0.3, through the dark flow induced cosmic microwave background (CMB) dipole in directions of clusters. We point out that, if this dark flow exists, it will also induce observable CMB temperature fluctuations at multipole l ~ 103, through modulation of the inhomogeneous electron distribution on the uniform dark flow. The induced small-scale kinetic Sunyaev-Zel'dovich (SZ) effect will reach ~ 1? K2 at multipole 103 <~ l <~ 104, only a factor of ~ 2 smaller than the conventional kinetic SZ effect. Furthermore, it will be correlated with the large-scale structure (LSS) and its correlation with Two-Micron All-Sky Survey (2MASS) galaxy distribution reaches 0.3?K at l = 103, under a directional dependent optimal weighting scheme. We estimate that, Wilkinson Microwave Anisotropy Probe plus 2MASS should already be able to detect this dark flow induced small-scale kinetic SZ effect with ~ 6? confidence. Deeper galaxy surveys such as the Sloan Digital Sky Survey can further improve the measurement. Planck plus existing galaxy surveys can reach >rsim 14? detection. Existing CMB-LSS cross-correlation measurements shall be reanalysed to test the existence of the dark flow and, if it exists, shall be used to eliminate possible bias on the integrated Sachs-Wolfe effect measurement through the CMB-LSS cross-correlation.

Zhang, Pengjie

2010-09-01

175

Effects of Interstate Banking on Small Business Lending.  

National Technical Information Service (NTIS)

The study investigates how bank acquisitions influence the willingness of a banking organization to lend to small businesses. The concern that bank consolidation may reduce credit availability to small businesses is related to several factors. First, duri...

J. Peek

1997-01-01

176

Real material effects in laser fusion direct-drive targets  

NASA Astrophysics Data System (ADS)

In our previous direct-drive target designs1 we use all-CH ablator, all-CH wicked foam and all-DT fuel. In practice, all these various components of a direct-drive target will most likely contain impurities and/or contaminants. We look at the effects of various impurities in these components. We start from a high-yield design (G>100) and introduce in succession impurities in the various components of the target. The effects of impurities will be shown on the gain and 1D stability analysis. Pulse shape modifications are required to make the target burn in the presence of some impurities and limits on impurity levels for acceptable performance of the targets will be shown and discussed. Work supported by USDOE under a contract with NRL. 1. D.Colombant et al, Proc. 26th ECLIM,2000 SPIE Vol. 4424, 224 (2001)

Colombant, Denis G.; Schmitt, Andrew J.

2001-10-01

177

Direct detection of the Yarkovsky effect by radar ranging to asteroid 6489 Golevka.  

PubMed

Radar ranging from Arecibo, Puerto Rico, to the 0.5-kilometer near-Earth asteroid 6489 Golevka unambiguously reveals a small nongravitational acceleration caused by the anisotropic thermal emission of absorbed sunlight. The magnitude of this perturbation, known as the Yarkovsky effect, is a function of the asteroid's mass and surface thermal characteristics. Direct detection of the Yarkovsky effect on asteroids will help constrain their physical properties, such as bulk density, and refine their orbital paths. Based on the strength of the detected perturbation, we estimate the bulk density of Golevka to be 2.7(+0.4)(-0.6) grams per cubic centimeter. PMID:14657492

Chesley, Steven R; Ostro, Steven J; Vokrouhlicky, David; Capek, David; Giorgini, Jon D; Nolan, Michael C; Margot, Jean-Luc; Hine, Alice A; Benner, Lance A M; Chamberlin, Alan B

2003-12-01

178

Effect of Speed (Centrifugal Load) on Gear Crack Propagation Direction  

NASA Technical Reports Server (NTRS)

The effect of rotational speed (centrifugal force) on gear crack propagation direction was explored. Gears were analyzed using finite element analysis and linear elastic fracture mechanics. The analysis was validated with crack propagation experiments performed in a spur gear fatigue rig. The effects of speed, rim thickness, and initial crack location on gear crack propagation direction were investigated. Crack paths from the finite element method correlated well with those deduced from gear experiments. For the test gear with a backup ratio (rim thickness divided by tooth height) of nib = 0.5, cracks initiating in the tooth fillet propagated to rim fractures when run at a speed of 10,000 rpm and became tooth fractures for speeds slower than 10,000 rpm for both the experiments and anal sis. From additional analysis, speed had little effect on crack propagation direction except when initial crack locations were near the tooth/rim fracture transition point for a given backup ratio. When at that point, higher speeds tended to promote rim fracture while lower speeds (or neglecting centrifugal force) produced tooth fractures.

Lewicki, David G.

2001-01-01

179

Direct mapping of nuclear shell effects in the heaviest elements.  

PubMed

Quantum-mechanical shell effects are expected to strongly enhance nuclear binding on an "island of stability" of superheavy elements. The predicted center at proton number Z = 114, 120, or 126 and neutron number N = 184 has been substantiated by the recent synthesis of new elements up to Z = 118. However, the location of the center and the extension of the island of stability remain vague. High-precision mass spectrometry allows the direct measurement of nuclear binding energies and thus the determination of the strength of shell effects. Here, we present such measurements for nobelium and lawrencium isotopes, which also pin down the deformed shell gap at N = 152. PMID:22878498

Minaya Ramirez, E; Ackermann, D; Blaum, K; Block, M; Droese, C; Düllmann, Ch E; Dworschak, M; Eibach, M; Eliseev, S; Haettner, E; Herfurth, F; Heßberger, F P; Hofmann, S; Ketelaer, J; Marx, G; Mazzocco, M; Nesterenko, D; Novikov, Yu N; Plaß, W R; Rodríguez, D; Scheidenberger, C; Schweikhard, L; Thirolf, P G; Weber, C

2012-09-01

180

26 CFR 1.1202-2 - Qualified small business stock; effect of redemptions.  

Code of Federal Regulations, 2010 CFR

...Qualified small business stock; effect of redemptions. 1.1202-2...Qualified small business stock; effect of redemptions. (a) Redemptions...or mental incompetency, or divorce. A stock purchase is disregarded...selling shareholder; or (4) Divorce. The stock is...

2009-04-01

181

26 CFR 1.1202-2 - Qualified small business stock; effect of redemptions.  

Code of Federal Regulations, 2010 CFR

...Qualified small business stock; effect of redemptions. 1.1202-2...Qualified small business stock; effect of redemptions. (a) Redemptions...or mental incompetency, or divorce. A stock purchase is disregarded...selling shareholder; or (4) Divorce. The stock is...

2010-04-01

182

Effects of Compositional Defects on Small Polaron Hopping in Micas  

SciTech Connect

Hartree-Fock calculations and electron transfer (ET) theory were used to model the effects of compositional defects on ET in the brucite-like octahedral sheet of mica. ET was modeled as a FeII/III valence interchange reaction across shared octahedral edges of the M2-M2 iron sublattice. The model entails the hopping of localized electrons and small polaron behavior. Hartree-Fock calculations indicate that substitution of F for structural OH bridges increases the reorganization energy l, decreases the electronic coupling matrix element VAB, and thereby substantially decreases the hopping rate. The l increase arises from modification of the metal-ligand bond force constants, and the VAB decrease arises from reduction of superexchange interaction through anion bridges. Deprotonation of an OH bridge, consistent with a possible mechanism of maintaining charge neutrality during net oxidation, yields a net increase in the ET rate. Although substitution of Al or Mg for Fe in M1 sites distorts the structure of adjacent Fe-occupied M2 sites, the distortion has little net impact on ET rates through these M2 sites. Hence the main effect of Al or Mg substitution for Fe, should it occur in the M2 sublattice, is to block ET pathways. Collectively, these findings pave the way for larger-scale oxidation/reduction models to be constructed for realistic, compositionally diverse micas

Rosso, Kevin M.; Ilton, Eugene S.

2005-06-01

183

Effects of compositional defects on small polaron hopping in micas.  

PubMed

Hartree-Fock calculations and electron transfer (ET) theory were used to model the effects of compositional defects on ET in the brucite-like octahedral sheet of mica. ET was modeled as an Fe(IIIII) valence interchange reaction across shared octahedral edges of the M2-M2 iron sublattice. The model entails the hopping of localized electrons and small polaron behavior. Hartree-Fock calculations indicate that substitution of F for structural OH bridges increases the reorganization energy lambda, decreases the electronic coupling matrix element V(AB), and thereby substantially decreases the hopping rate. The lambda increase arises from modification of the metal-ligand bond force constants, and the V(AB) decrease arises from reduction of superexchange interaction through anion bridges. Deprotonation of an OH bridge, consistent with a possible mechanism of maintaining charge neutrality during net oxidation, yields a net increase in the ET rate. Although substitution of Al or Mg for Fe in M1 sites distorts the structure of adjacent Fe-occupied M2 sites, the distortion has little net impact on ET rates through these M2 sites. Hence the main effect of Al or Mg substitution for Fe, should it occur in the M2 sublattice, is to block ET pathways. Collectively, these findings pave the way for larger-scale oxidation/reduction models to be constructed for realistic, compositionally diverse micas. PMID:16035795

Rosso, Kevin M; Ilton, Eugene S

2005-06-22

184

Effect of spine hardware on small spinal stereotactic radiosurgery dosimetry.  

PubMed

Monte Carlo (MC) modeling of a 6 MV photon beam was used to study the dose perturbation from a titanium rod 5 mm in diameter in various small fields range from 2 × 2 to 5 × 5 cm(2). The results showed that the rod increased the dose to water by ?6% at the water-rod interface because of electron backscattering and decreased the dose by ?7% in the shadow of the rod because of photon attenuation. The Pinnacle(3) treatment planning system calculations matched the MC results at the depths more than 1 cm past the rod when the correct titanium density of 4.5 g cm(-3) was used, but significantly underestimated the backscattering dose at the water-rod interface. A CT-density table with a top density of 1.82 g cm(-3) (cortical bone) is a practical way to reduce the dosimetric error from the artifacts by preventing high density assignment to them, but can underestimates the attenuation by the titanium rod by 6%. However, when multi-beam with intensity modulation is used in actual patient spinal stereotactic radiosurgery treatment, the dosimetric effect of assigning 4.5 instead of 1.82 g cm(-3) to titanium implants is complicated. It ranged from minimal effect to 2% dose difference affecting 15% target volume in the study. When hardware is in the beam path, density override to the titanium hardware is recommended. PMID:24018829

Wang, Xin; Yang, James N; Li, Xiaoqiang; Tailor, Ramesh; Vassilliev, Oleg; Brown, Paul; Rhines, Laurence; Chang, Eric

2013-10-01

185

Effect of spine hardware on small spinal stereotactic radiosurgery dosimetry  

NASA Astrophysics Data System (ADS)

Monte Carlo (MC) modeling of a 6 MV photon beam was used to study the dose perturbation from a titanium rod 5 mm in diameter in various small fields range from 2 × 2 to 5 × 5 cm2. The results showed that the rod increased the dose to water by ˜6% at the water-rod interface because of electron backscattering and decreased the dose by ˜7% in the shadow of the rod because of photon attenuation. The Pinnacle3 treatment planning system calculations matched the MC results at the depths more than 1 cm past the rod when the correct titanium density of 4.5 g cm-3 was used, but significantly underestimated the backscattering dose at the water-rod interface. A CT-density table with a top density of 1.82 g cm-3 (cortical bone) is a practical way to reduce the dosimetric error from the artifacts by preventing high density assignment to them, but can underestimates the attenuation by the titanium rod by 6%. However, when multi-beam with intensity modulation is used in actual patient spinal stereotactic radiosurgery treatment, the dosimetric effect of assigning 4.5 instead of 1.82 g cm-3 to titanium implants is complicated. It ranged from minimal effect to 2% dose difference affecting 15% target volume in the study. When hardware is in the beam path, density override to the titanium hardware is recommended.

Wang, Xin; Yang, James N.; Li, Xiaoqiang; Tailor, Ramesh; Vassilliev, Oleg; Brown, Paul; Rhines, Laurence; Chang, Eric

2013-10-01

186

Why do pitched horizontal lines have such a small effect on visually perceived eye level?  

NASA Technical Reports Server (NTRS)

In two experiments, visually perceived eye level (VPEL) was measured while subjects viewed two-dimensional displays that were either upright or pitched 20 degrees top-toward or 20 degrees top-away from them. In Experiment 1, it was demonstrated that binocular exposure to a pair of pitched vertical lines or to a pitched random dot pattern caused a substantial upward VPEL shift for the top-toward pitched array and a similarly large downward shift for the top-away array. On the other hand, the same pitches of a pair of horizontal lines (viewed binocularly or monocularly) produced much smaller VPEL shifts. Because the perceived pitch of the pitched horizontal line display was nearly the same as the perceived pitch of the pitched vertical line and dot array, the relatively small influence of pitched horizontal lines on VPEL cannot be attributed simply to an underestimation of their pitch. In Experiment 2, the effects of pitched vertical lines, dots, and horizontal lines on VPEL were again measured, together with their effects on resting gaze direction (in the vertical dimension). As in Experiment 1, vertical lines and dots caused much larger VPEL shifts than did horizontal lines. The effects of the displays on resting gaze direction were highly similar to their effects on VPEL. These results are consistent with the hypothesis that VPEL shifts caused by pitched visual arrays are due to the direct influence of these arrays on the oculomotor system and are not mediated by perceived pitch.

Post, R. B.; Welch, R. B.; Clark, V. D.

2000-01-01

187

Spin Rate Distribution of Small Asteroids Shaped by YORP Effect  

NASA Astrophysics Data System (ADS)

We studied a distribution of spin rates of main belt/Mars crossing (MB/MC) asteroids with diameters 3-15 km using data obtained within the Photometric Survey of Asynchronous Binary Asteroids (Pravec et al. 2008). We found that the spin distribution of the small asteroids is uniform in the range from f = 1 to 9.5 d-1, and there is an excess of slow rotators with f < 1 d-1. The observed distribution appears to be controlled by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. The magnitude of the excess of slow rotators is related to the residence time of slowed down asteroids in the excess and the rate of spin rate change outside the excess. We estimated a median YORP spin rate change of 0.022 d-1/Myr for asteroids in our sample (i.e., a median time in which the spin rate changes by 1 d-1 is 45 Myr), thus the residence time of slowed down asteroids in the excess is 110 Myr. The spin rate distribution of near-Earth asteroids (NEAs) with sizes in the range 0.2-3 km ( 5-times smaller in median diameter than the MB/MC asteroids sample) shows a similar excess of slow rotators, but there is also a concentration of NEAs at fast spin rates with f = 9-10 d-1. The concentration at fast spin rates is correlated with a narrower distribution of spin rates of primaries of binary systems among NEAs; the difference may be due to the apparently more evolved population of binaries among MB/MC asteroids. Reference: Pravec, P., and 30 colleagues, 2008. Spin rate distribution of small asteroids. Icarus, in press. DOI: http://dx.doi.org/10.1016/j.icarus.2008.05.012

Pravec, Petr

2008-09-01

188

Direct observation of the size dependence of Dexter energy transfer from polymer to small PbS quantum dots  

NASA Astrophysics Data System (ADS)

Small PbS quantum dots (QDs) with diameters ranging from 2.5 to 3 nm were synthesized directly in the conjugated polymer poly[2-methoxy-5-(2'-ethyl-hexyloxy)-p-phenylene vinylene] (MEH-PPV) at 70 °C. To monitor the size dependence of Dexter energy transfer [D. L. Dexter, J. Chem. Phys. 21, 836 (1953)] from MEH-PPV to PbS QDs, the photoluminescence of MEH-PPV is measured for a series of samples with varying QD sizes controlled by the reaction time. A decreased transfer rate is observed for PbS QDs with a diameter of about 2.65 nm due to the minimum overlap between the emission spectrum of MEH-PPV and the 1Se-1Sh and 1Pe-1Sh transitions of PbS QDs.

Zhang, Yating; Xu, Zhangcheng

2008-08-01

189

The Effect of Direction on Cursor Moving Kinematics  

PubMed Central

There have been only few studies to substantiate the kinematic characteristics of cursor movement. In this study, a quantitative experimental research method was used to explore the effect of moving direction on the kinematics of cursor movement in 24 typical young persons using our previously developed computerized measuring program. The results of multiple one way repeated measures ANOVAs and post hoc LSD tests demonstrated that the moving direction had effects on average velocity, movement time, movement unit and peak velocity. Moving leftward showed better efficiency than moving rightward, upward and downward from the kinematic evidences such as velocity, movement unit and time. Moreover, the unique pattern of the power spectral density (PSD) of velocity (strategy for power application) explained why the smoothness was still maintained while moving leftward even under an unstable situation with larger momentum. Moreover, the information from this cursor moving study can guide us to relocate the toolbars and icons in the window interface, especially for individuals with physical disabilities whose performances are easily interrupted while controlling the cursor in specific directions.

Meng, Ling-Fu; Chen, Hsin-Yung; Lu, Chiu-Ping; Chen, Ming-Chung; Chu, Chi-Nung

2012-01-01

190

Effect of State and Local Contracting on Small Firms. Small Business Research Summary.  

National Technical Information Service (NTIS)

The study provides an in-depth picture of state and local government contracting with the private sector. The goal was to learn the extent in dollars, percentage of budgets, and types of contracts that states and local governments contract with small firm...

D. A. Walker E. M. Chant

1991-01-01

191

Direct coupling of annexin A5 to VSOP yields small, protein-covered nanoprobes for MR imaging of apoptosis.  

PubMed

Annexin A5 (Anx) has been extensively used for imaging apoptosis by single-photon emission computed tomography, positron emission tomography, optical imaging and MRI. Recently we introduced ultrasmall Anx-VSOP (very small iron oxide particles)--the smallest high-relaxivity probe for MRI of apoptosis. Here we present a simplified method for the direct coupling of Anx to VSOP, which resulted in nanoparticles that are nearly completely covered with human Anx. These superparamagnetic nanoparticles are only 14.4 ± 2.3 nm in diameter and have higher T2* relaxivity. Compared with existing probes, the small size and the Anx shielding provide prerequisites for good biocompatibility and bioavailability in target tissues. In vitro characterization showed specific binding of Anx-VSOP to apoptotic cells, which led to a signal loss in T2*-weighted MR measurements, while control probe M1324-VSOP produced no such change. Exploratory MRI was done in vivo in a cardiac model of ischemia-reperfusion damage illustrating the potential of the probe for future studies. PMID:24706613

Figge, Lena; Appler, Franziska; Chen, Howard H; Sosnovik, David E; Schnorr, Jörg; Seitz, Oliver; Taupitz, Matthias; Hamm, Bernd; Schellenberger, Eyk

2014-01-01

192

Comparative Effectiveness and Implementation Research: Directions for Neurology  

PubMed Central

There is an enormous unmet need for knowledge about how new insights from discovery and translational research can yield measurable, population-level improvements in health and reduction in mortality among those having or at risk for neurological disease. Once several, well-conducted randomized controlled trials establish the efficacy of a given therapy, implementation research can generate new knowledge about barriers to uptake of the therapy into widespread clinical care, and what strategies are effective in overcoming those barriers and in addressing health disparities. Comparative effectiveness research aims to elucidate the relative value (including clinical benefit, clinical harms, and/or costs) of alternative efficacious management approaches to a neurological disorder, generally through direct comparisons, and may include comparisons of methodologies for implementation. Congress has recently appropriated resources and established an institute to prioritize funding for such research. Neurologists and neuroscientists should understand the scope and objectives of comparative effectiveness and implementation research, their range of methodological approaches (formal literature syntheses, randomized trials, observational studies, modeling), and existing research resources (centers for literature synthesis, registries, practice networks) relevant to research for neurological conditions, in order to close the well-documented “evidence-to-practice gap.” Future directions include building this research resource capacity, producing scientists trained to conduct rigorous comparative effectiveness and implementation research, and embracing innovative strategies to set research priorities in these areas.

Vickrey, Barbara G.; Hirtz, Deborah; Waddy, Salina; Cheng, Eric M.; Johnston, S. Claiborne

2013-01-01

193

Direct renal hemodynamic effects of two vasodilators: diazoxide and acetylcholine.  

PubMed

The direct renal hemodynamic effect of two different vasodilators, diazoxide and acetylcholine, in the anesthetized dog, were studied. In 12 dogs (Group 1), diazoxide was given first directly into the renal artery and was followed by the addition of acetylcholine. In 6 dogs (Group 2) the order of drug administration was reversed. The glomerular filtration rate (GFR), the effective renal plasma flow (ERDF), and the excretion of sodium, potassium, chloride, and urine output were determined for both control and experimental (infused) kidneys. Both drugs when given alone resulted in a significant increase of all parameters tested on the experimental kidney, except the ERPF which was spuriously decreased by diazoxide. The addition of either drug upon the first given did not produce and further effect. It was, therefore, concluded that the hemodynamic changes, as well as the handling of electrolytes and water by the kidney, were solely due to the vasodilating properties of both compounds. A local renal tubular effect by diazoxide concerning sodium excretion could not be substantiated by our studies. PMID:1190913

Chrysant, S G; Lavender, A R

1975-09-01

194

Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates  

USGS Publications Warehouse

We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

Esque, T. C.; Schwalbe, C. R.; Defalco, L. A.; Duncan, R. B.; Hughes, T. J.

2003-01-01

195

Elements essential for accumulation and function of small nucleolar RNAs directing site-specific pseudouridylation of ribosomal RNAs.  

PubMed

During site-specific pseudouridylation of eukaryotic rRNAs, selection of correct substrate uridines for isomerization into pseudouridine is directed by small nucleolar RNAs (snoRNAs). The pseudouridylation guide snoRNAs share a common 'hairpin-hinge- hairpin-tail' secondary structure and two conserved sequence motifs, the H and ACA boxes, located in the single-stranded hinge and tail regions, respectively. In the 5'- and/or 3'-terminal hairpin, an internal loop structure, the pseudouridylation pocket, selects the target uridine through formation of base-pairing interactions with rRNAs. Here, essential elements for accumulation and function of rRNA pseudouridylation guide snoRNAs have been analysed by expressing various mutant yeast snR5, snR36 and human U65 snoRNAs in yeast cells. We demonstrate that the H and ACA boxes that are required for formation of the correct 5' and 3' ends of the snoRNA, respectively, are also essential for the pseudouridylation reaction directed by both the 5'- and 3'-terminal pseudouridylation pockets. Similarly, RNA helices flanking the two pseudouridylation pockets are equally essential for pseudouridylation reactions mediated by either the 5' or 3' hairpin structure, indicating that the two hairpin domains function in a highly co-operative manner. Finally, we demonstrate that by manipulating the rRNA recognition motifs of pseudouridylation guide snoRNAs, novel pseudouridylation sites can be generated in yeast rRNAs. PMID:9889201

Bortolin, M L; Ganot, P; Kiss, T

1999-01-15

196

Effective hydrogen generator testing for on-site small engine  

NASA Astrophysics Data System (ADS)

We propose a new concept of hydrogen generator testing for on-site small engine. In general, there is a trade-off between simpler vehicle design and infrastructure issues, for instance, liquid fuels such as gasoline and methanol for small engine use. In this article we compare the hydrogen gases combination the gasoline between normal systems (gasoline only) for small engine. The advantage of the hydrogen combines gasoline for small engine saving the gasoline 25%. Furthermore, the new concept of hydrogen combination for diesel engine, bio-diesel engine, liquid petroleum gas (LPG), natural gas vehicle (NGV), which is discussed in details.

Chaiwongsa, Praitoon; Pornsuwancharoen, Nithiroth; Yupapin, Preecha P.

197

The effect of directivity in a PSHA framework  

NASA Astrophysics Data System (ADS)

We propose a method to introduce a refined representation of the ground motion in the framework of the Probabilistic Seismic Hazard Analysis (PSHA). This study is especially oriented to the incorporation of a priori information about source parameters, by focusing on the directivity effect and its influence on seismic hazard maps. Two strategies have been followed. One considers the seismic source as an extended source, and it is valid when the PSHA seismogenetic sources are represented as fault segments. We show that the incorporation of variables related to the directivity effect can lead to variations up to 20 per cent of the hazard level in case of dip-slip faults with uniform distribution of hypocentre location, in terms of spectral acceleration response at 5 s, exceeding probability of 10 per cent in 50 yr. The second one concerns the more general problem of the seismogenetic areas, where each point is a seismogenetic source having the same chance of enucleate a seismic event. In our proposition the point source is associated to the rupture-related parameters, defined using a statistical description. As an example, we consider a source point of an area characterized by strike-slip faulting style. With the introduction of the directivity correction the modulation of the hazard map reaches values up to 100 per cent (for strike-slip, unilateral faults). The introduction of directivity does not increase uniformly the hazard level, but acts more like a redistribution of the estimation that is consistent with the fault orientation. A general increase appears only when no a priori information is available. However, nowadays good a priori knowledge exists on style of faulting, dip and orientation of faults associated to the majority of the seismogenetic zones of the present seismic hazard maps. The percentage of variation obtained is strongly dependent on the type of model chosen to represent analytically the directivity effect. Therefore, it is our aim to emphasize more on the methodology following which, all the information collected may be easily converted to obtain a more comprehensive and meaningful probabilistic seismic hazard formulation.

Spagnuolo, E.; Herrero, A.; Cultrera, G.

2012-09-01

198

Direct and indirect effects of body weight on adult wages.  

PubMed

Previous estimates of the association between body weight and wages in the literature have been conditional on education and occupation. In addition to the effect of current body weight status (body mass index (BMI) or obesity) on wages, this paper examines the indirect effect of body weight status in the late-teenage years on wages operating through education and occupation choice. Using the National Longitudinal Survey of Youth 1979 data, for women, we find that a one-unit increase in BMI is directly associated with 1.83% lower hourly wages whereas the indirect BMI wage penalty is not statistically significant. Neither a direct nor an indirect BMI wage penalty is found for men. However, results based on clinical weight classification reveal that the indirect wage penalty occurs to a larger extent at the upper tail of the BMI distribution for both men and women via the pathways of education and occupation outcomes. Late-teen obesity is indirectly associated with 3.5% lower hourly wages for both women and men. These results are important because they imply that the total effect of obesity on wages is significantly larger than has been estimated in previous cross-sectional studies. PMID:21820369

Han, Euna; Norton, Edward C; Powell, Lisa M

2011-12-01

199

Direct positive inotropic and vasoconstrictor effects of endothelin.  

PubMed

Endothelin, a newly discovered vasoconstrictor peptide, when added to isolated cat papillary muscles, induced a direct positive inotropic effect that was slow in onset but of long duration. The magnitude of the developed force was concentration dependent. Endothelin exerted a marked concentration-dependent vasoconstriction in isolated cat carotid arteries and rabbit aortic rings. In both the carotid arteries and the aortic rings, endothelin induced a similar vasoconstrictor effect in the presence or absence of an intact endothelium. Addition of propyl gallate, a 5-lipoxygenase inhibitor, ibuprofen, a cyclooxygenase inhibitor, or SKF-525A, a cytochrome P450 inhibitor, at 2 microM did not significantly attenuate the ability of endothelin to vasoconstrict aortic rings in the presence or absence of an intact endothelium. These results demonstrate that the vasoconstrictor activity of endothelin operates independently of all three pathways of arachidonic acid metabolism (i.e., lipoxygenase, cyclooxygenase, or cytochrome P450 pathways) and is not dependent upon other endothelium-derived mediators (e.g., endothelium-derived relaxing factor, or eicosanoids) in these preparations. Moreover, endothelin exerts a direct positive inotropic effect in isolated cat ventricular myocardial tissue. PMID:2193909

Siegfried, M R; Aoki, N; Mulloy, D; Lefer, A M

1990-01-01

200

Brisk and Effective Fluency Instruction for Small Groups  

ERIC Educational Resources Information Center

Fluency is known as the bridge between phonics and comprehension. Teachers of reading provide high-quality instruction in phonics and decoding strategies, usually in a small-group format, but may be unsure how to insert fluency instruction into the small-group lesson. This article presents key concepts in fluency instruction and a description of…

Wilson, Judith K.

2012-01-01

201

Can "Twinning" Be Applied Effectively to Small Library Associations?  

ERIC Educational Resources Information Center

Based on an informal survey of 26 small national library associations, this paper examines "twinning" (i.e., a formal substantive collaboration between two organizations) between library associations in general and with particular emphasis on the small associations' experience. It examines their characteristics and discusses the perceived benefits…

Amenu-Kpodo, Norma

202

Scanner effects on directed self-assembly patterning  

NASA Astrophysics Data System (ADS)

Directed self-assembly (DSA) of various polymers is a potential next-generation lithography component. Lithographers can use an ArF scanner to print guide structures with pitches accessible with current technology. The DSA materials, in a non-exposure step, perform pitch multiplication of 1-D and 2-D guide structures. While research has investigated defects inherent to the DSA material, ArF scanner effects have received little attention. This work uses DSA models and scanner models to assess requirements for ArF immersion scanners for DSA complimentary lithography.

Renwick, Stephen P.

2014-03-01

203

Cost-effective compliance for the small provider.  

PubMed

Small provider organizations often have limited resources with which to implement a compliance program. The Office of Inspector General (OIG) has indicated that a small organization may take a less formal approach to compliance and develop a compliance program that fits its budget and resources. But small providers should take seriously the need for a compliance program despite the OIG's greater latitude toward small organizations. Whatever the size of their budget, small providers should emphasize due diligence and good-faith approaches to compliance to demonstrate to investigators and employees that they have made compliance a priority. These efforts can encourage the OIG to look more favorably upon the organization in the event of a compliance breach and also can improve the organization's financial performance by improving overall management of the organization. PMID:11009826

Fedor, F P

2000-07-01

204

The Effect of Small-Scale Forcing on Large-Scale Structures in Two-Dimensional Flows  

Microsoft Academic Search

The effect of small scale forcing on large scale structures in $\\\\beta$-plane two-dimensional (2D) turbulence is studied using long-term direct numerical simulations (DNS). We find that nonlinear effects remain strong at all times and for all scales and establish an inverse energy cascade that extends to the largest scales available in the system. The large scale flow develops strong spectral

Alexei Chekhlov; Steven A. Orszag; Semion Sukoriansky; Boris Galperin; Ilya Staroselsky

1996-01-01

205

Direct effects of hepatitis C virus on the lymphoid cells.  

PubMed

It has been reported that the direct binding of hepatitis C virus (HCV) and/or the replication of HCV in the extrahepatic organs and, especially, lymphoid cells, might affect the pathogenesis of extrahepatic diseases with HCV infection. More than one decade ago, several reports described the existence of HCV-RNA in peripheral blood mononuclear cells. Moreover, many reports describing the existence of HCV in B lymphocytes and B cell lymphoma have been published. In addition to B lymphocytes, it was reported that HCV replication could be detected in T lymphocytes and T cell lines. Among the extrahepatic diseases with HCV infection, mixed cryoglobulinemia-related diseases and autoimmune-related diseases are important for understanding the immunopathogensis of HCV persistent infection. Moreover, HCV persistent infection can cause malignant lymphoma. The biological significance of lymphotropic HCV has not yet become clear. However, several candidates have been considered for a long time. One is that lymphotropic HCV is an HCV reservoir that might contribute to the recurrence of HCV infection and difficult-to-treat disease status. The other important issue is the carcinogenesis of the lymphoid cells and disturbances of the immune responses. Therefore, the extrahepatic diseases might be induced by direct interaction between HCV and lymphoid cells. In this article, we summarize various studies showing the direct effect of HCV on lymphoid cells and discuss the biological significance of lymphotropic HCV. PMID:24307783

Kondo, Yasuteru; Shimosegawa, Tooru

2013-11-28

206

Test Report: Direct and Indirect Lightning Effects on Composite Materials  

NASA Technical Reports Server (NTRS)

Lightning tests were performed on composite materials as a part of an investigation of electromagnetic effects on the materials. Samples were subjected to direct and remote simulated lightning strikes. Samples included various thicknesses of graphite filament reinforced plastic (GFRP), material enhanced by expanded aluminum foil layers, and material with an aluminum honeycomb core. Shielding properties of the material and damage to the sample surfaces and joints were investigated. Adding expanded aluminum foil layers and increasing the thickness of GFRP improves the shielding effectiveness against lightning induced fields and the ability to withstand lightning strikes. A report describing the lightning strike tests performed by the U.S. Army Redstone Technical Test Center, Redstone Arsenal, AL, STERT-TE-E-EM, is included as an appendix.

Evans, R. W.

1997-01-01

207

The direct magnetoelectric effect in ferroelectric-ferromagnetic epitaxial heterostructures.  

PubMed

Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films. PMID:23872985

Fina, I; Dix, N; Rebled, J M; Gemeiner, P; Martí, X; Peiró, F; Dkhil, B; Sánchez, F; Fàbrega, L; Fontcuberta, J

2013-09-01

208

Magnetic field and symmetry effects in small quantum dots  

Microsoft Academic Search

Shell phenomena in small quantum dots with a few electrons under a perpendicular magnetic field are discussed within a simple\\u000a model. It is shown that various kinds of shell structures, which occur at specific values for the magnetic field lead to a\\u000a disappearance of the orbital magnetization for particular magic numbers for noninteracting electrons in small quantum dots.\\u000a Including the

R. G. Nazmitdinov

2009-01-01

209

Herbivory in global climate change research: direct effects of rising temperature on insect herbivores  

Microsoft Academic Search

This review examines the direct effects of climate change on insect herbivores. Temperature is identified as the dominant abiotic factor directly affecting herbivorous insects. There is little evidence of any direct effects Of CO2 or UVB. Direct impacts of precipitation have been largely neglected in current research on climate change. Temperature directly affects development, survival, range and abundance. Species with

Jeffery S. Bale; Gregory J. Masters; Ian D. Hodkinson; Caroline Awmack; T. Martijn Bezemer; Valerie K. Brown; Jennifer Butterfield; Alan Buse; John C. Coulson; John Farrar; John E. G. Good; Richard Harrington; Susane Hartley; T. Hefin Jones; Richard L. Lindroth; Ilias Symrnioudis; Allan D. Watt; John B. Whittaker

2002-01-01

210

First Isolation and Direct Evidence for the Existence of Large Small-Mammal Reservoirs of Leptospira sp. in Madagascar  

PubMed Central

Background Leptospirosis has long been a major public health concern in the southwestern Indian Ocean. However, in Madagascar, only a few, old studies have provided indirect serological evidence of the disease in humans or animals. Methodology/Principal Findings We conducted a large animal study focusing on small-mammal populations. Five field trapping surveys were carried out at five sites, from April 2008 to August 2009. Captures consisted of Rattus norvegicus (35.8%), R. rattus (35.1%), Mus musculus (20.5%) and Suncus murinus (8.6%). We used microbiological culture, serodiagnosis tests (MAT) and real-time PCR to assess Leptospira infection. Leptospira carriage was detected by PCR in 91 (33.9%) of the 268 small mammals, by MAT in 17 of the 151 (11.3%) animals for which serum samples were available and by culture in 9 of the 268 animals (3.3%). Rates of infection based on positive PCR results were significantly higher in Moramanga (54%), Toliara (48%) and Mahajanga (47.4%) than in Antsiranana (8.5%) and Toamasina (14%) (p?=?0.001). The prevalence of Leptospira carriage was significantly higher in R. norvegicus (48.9%), S. murinus (43.5%) and R. rattus (30.8%) than in M. musculus (9.1%) (p<0.001). The MAT detected antibodies against the serogroups Canicola and Icterohaemorrhagiae. Isolates were characterized by serology, secY sequence-based phylogeny, partial sequencing of rrs, multi-locus VNTR analysis and pulsed field gel electrophoresis. The 10 isolates obtained from nine rats were all identified as species L. interrogans serogroup Canicola serovar Kuwait and all had identical partial rrs and secY sequences. Conclusions/Significance We present here the first direct evidence of widespread leptospiral carriage in small mammals in Madagascar. Our results strongly suggest a high level of environmental contamination, consistent with probable transmission of the infection to humans. This first isolation of pathogenic Leptospira strains in this country may significantly improve the detection of specific antibodies in human cases.

Rahelinirina, Soanandrasana; Leon, Albertine; Harstskeerl, Rudy A.; Sertour, Natacha; Ahmed, Ahmed; Raharimanana, Claudine; Ferquel, Elisabeth; Garnier, Martine; Chartier, Loic; Duplantier, Jean-Marc; Rahalison, Lila; Cornet, Muriel

2010-01-01

211

Neurobiological Effects of Transcranial Direct Current Stimulation: A Review  

PubMed Central

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that is affordable and easy to operate compared to other neuromodulation techniques. Anodal stimulation increases cortical excitability, while the cathodal stimulation decreases it. Although tDCS is a promising treatment approach for chronic pain as well as for neuropsychiatric diseases and other neurological disorders, several complex neurobiological mechanisms that are not well understood are involved in its effect. The purpose of this systematic review is to summarize the current knowledge regarding the neurobiological mechanisms involved in the effects of tDCS. The initial search resulted in 171 articles. After applying inclusion and exclusion criteria, we screened 32 full-text articles to extract findings about the neurobiology of tDCS effects including investigation of cortical excitability parameters. Overall, these findings show that tDCS involves a cascade of events at the cellular and molecular levels. Moreover, tDCS is associated with glutamatergic, GABAergic, dopaminergic, serotonergic, and cholinergic activity modulation. Though these studies provide important advancements toward the understanding of mechanisms underlying tDCS effects, further studies are needed to integrate these mechanisms as to optimize clinical development of tDCS.

Medeiros, Liciane Fernandes; de Souza, Izabel Cristina Custodio; Vidor, Liliane Pinto; de Souza, Andressa; Deitos, Alicia; Volz, Magdalena Sarah; Fregni, Felipe; Caumo, Wolnei; Torres, Iraci L. S.

2012-01-01

212

Natural direct and indirect effects on the exposed: effect decomposition under weaker assumptions.  

PubMed

We define natural direct and indirect effects on the exposed. We show that these allow for effect decomposition under weaker identification conditions than population natural direct and indirect effects. When no confounders of the mediator-outcome association are affected by the exposure, identification is possible under essentially the same conditions as for controlled direct effects. Otherwise, identification is still possible with additional knowledge on a nonidentifiable selection-bias function which measures the dependence of the mediator effect on the observed exposure within confounder levels, and which evaluates to zero in a large class of realistic data-generating mechanisms. We argue that natural direct and indirect effects on the exposed are of intrinsic interest in various applications. We moreover show that they coincide with the corresponding population natural direct and indirect effects when the exposure is randomly assigned. In such settings, our results are thus also of relevance for assessing population natural direct and indirect effects in the presence of exposure-induced mediator-outcome confounding, which existing methodology has not been able to address. PMID:22989075

Vansteelandt, Stijn; Vanderweele, Tyler J

2012-12-01

213

A direct arylation-derived DPP-based small molecule for solution-processed organic solar cells.  

PubMed

A diketo-pyrrolo-pyrrole (DPP) oligomer containing three DPP cores (Ph4Th4(DPP)3) was synthesized via direct arylation of C-H bonds (DACH). Ph4Th4(DPP)3 has good solubility in many organic solvents, and shows a broad absorption band from the visible to near-infrared region as well as a field-effect hole mobility as high as 0.006 cm(2) V(-1) s(-1). Solution-processed bulk heterojunction organic solar cells based on blends of Ph4Th4(DPP)3 as electron donor and fullerene derivative as electron acceptor were fabricated. An optimized power conversion efficiency of 3.76% with a high open-circuit voltage of 0.85 V was achieved after finely tuning the morphology by changing the blend ratio and by adding additives. These results indicate that DACH is an effective way to produce ?-conjugated oligomers for organic solar cells. PMID:24334482

Liu, Shi-Yong; Fu, Wei-Fei; Xu, Jing-Qi; Fan, Cong-Cheng; Jiang, Hao; Shi, Minmin; Li, Han-Ying; Chen, Jun-Wu; Cao, Yong; Chen, Hong-Zheng

2014-01-10

214

A direct arylation-derived DPP-based small molecule for solution-processed organic solar cells  

NASA Astrophysics Data System (ADS)

A diketo-pyrrolo-pyrrole (DPP) oligomer containing three DPP cores (Ph4Th4(DPP)3) was synthesized via direct arylation of C-H bonds (DACH). Ph4Th4(DPP)3 has good solubility in many organic solvents, and shows a broad absorption band from the visible to near-infrared region as well as a field-effect hole mobility as high as 0.006 cm2 V-1 s-1. Solution-processed bulk heterojunction organic solar cells based on blends of Ph4Th4(DPP)3 as electron donor and fullerene derivative as electron acceptor were fabricated. An optimized power conversion efficiency of 3.76% with a high open-circuit voltage of 0.85 V was achieved after finely tuning the morphology by changing the blend ratio and by adding additives. These results indicate that DACH is an effective way to produce ?-conjugated oligomers for organic solar cells.

Liu, Shi-Yong; Fu, Wei-Fei; Xu, Jing-Qi; Fan, Cong-Cheng; Jiang, Hao; Shi, Minmin; Li, Han-Ying; Chen, Jun-Wu; Cao, Yong; Chen, Hong-Zheng

2014-01-01

215

Apparatus and method for making a security hologram with multi-images in different viewing direction on a small area  

NASA Astrophysics Data System (ADS)

The prior artwork for a Dot-matrix hologram is always animated by a computer instead of a man made sculptured model. For a computer graphic software, it is very easy to interlace several bitmap graphics ona small area. So, if we generate an interlaced graphic and transfer the bitmaps to corresponding gratings which diffract the illumination light to a specific direction with respect to each individual graphic, then it will have several viewing images in different view angles. Hologram has special light characteristics that are difficult to duplicate, so it has intrinsic advantage for anti-counterfeiting application. For more guarantee of security to protect the value paper from the fraud activity. We use a more complex and delicate multi-image hologram to hold back the ambition of copycat. In this paper, will describe how to transfer the images that generated by computer to a hologram. The concept for interlace graphics, and the apparatus that is easy to generate the dot grating with respect to each bitmap in the image, and the practical samples that made by this technology for anti-counterfeiting purpose.

Lu, Ying Tsung; Chi, Sien

2000-04-01

216

Economic Model of Direct and Indirect Effects of Tax Reform on Agriculture,  

National Technical Information Service (NTIS)

The study develops a model to examine the direct and indirect effects of tax reform on agricultural resources. Previous models have concentrated on the direct effects of a tax change on agricultural resources, but have largely ignored the indirect effects...

R. Boyd

1988-01-01

217

The direct magnetoelectric effect in ferroelectric-ferromagnetic epitaxial heterostructures  

NASA Astrophysics Data System (ADS)

Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films.Ferroelectric (FE) and ferromagnetic (FM) materials engineered in horizontal heterostructures allow interface-mediated magnetoelectric coupling. The so-called converse magnetoelectric effect (CME) has been already demonstrated by electric-field poling of the ferroelectric layers and subsequent modification of the magnetic state of adjacent ferromagnetic layers by strain effects and/or free-carrier density tuning. Here we focus on the direct magnetoelectric effect (DME) where the dielectric state of a ferroelectric thin film is modified by a magnetic field. Ferroelectric BaTiO3 (BTO) and ferromagnetic CoFe2O4 (CFO) oxide thin films have been used to create epitaxial FE/FM and FM/FE heterostructures on SrTiO3(001) substrates buffered with metallic SrRuO3. It will be shown that large ferroelectric polarization and DME can be obtained by appropriate selection of the stacking order of the FE and FM films and their relative thicknesses. The dielectric permittivity, at the structural transitions of BTO, is strongly modified (up to 36%) when measurements are performed under a magnetic field. Due to the insulating nature of the ferromagnetic layer and the concomitant absence of the electric-field effect, the observed DME effect solely results from the magnetostrictive response of CFO elastically coupled to the BTO layer. These findings show that appropriate architecture and materials selection allow overcoming substrate-induced clamping in multiferroic multi-layered films. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01011b

Fina, I.; Dix, N.; Rebled, J. M.; Gemeiner, P.; Martí, X.; Peiró, F.; Dkhil, B.; Sánchez, F.; Fàbrega, L.; Fontcuberta, J.

2013-08-01

218

Direct effects of cattle on grassland birds in Canada.  

PubMed

Effects of grazing on grassland birds are generally thought to be indirect, through alteration of vegetation structure; however, livestock can also affect nest survival directly through trampling and other disturbances (e.g., livestock-induced abandonment). We extracted data on nest fates from 18 grazing studies conducted in Canada. We used these data to assess rates of nest destruction by cattle among 9 ecoregions and between seasonal and rotational grazing systems. Overall, few nests were destroyed by cattle (average 1.5% of 9132 nests). Nest destruction was positively correlated with grazing pressure (i.e., stocking rate or grazing intensity), but nest survival was higher in more heavily grazed areas for some species. Because rates of destruction of grassland bird nests by cattle are low in Canada, management efforts to reduce such destruction may not be of ecological or economic value in Canada. Efectos Directos del Ganado sobre las Aves de Pastizales en Canadá PMID:24617945

Bleho, Barbara I; Koper, Nicola; Machtans, Craig S

2014-06-01

219

Direct and indirect effects of UVA on skin vessel leakiness  

SciTech Connect

By using the suction blister technique we have investigated the leakiness of skin vessels in healthy volunteers after whole-body suberythemogenic doses of UVA radiation (a quadrant on one side of the abdominal skin was shielded with lead-rubber). The accumulation of intravenously injected labeled albumin in blister fluid was slightly elevated 1 day after irradiation and increased significantly 2 days later. The blister concentrations of 4 endogenous plasma proteins (albumin, transferrin, IgG, and alpha 2-macroglobulin) were elevated 1 day after radiation exposure and normalized 2 days later. All changes were equal on irradiated and nonirradiated skin. It is concluded that UVA radiation can induce a continued or biphasic increased leakage of plasma proteins in the skin vessels, due to a humoral rather than to a direct physical effect of the radiation on the vessel walls. It is suggested that an increased microvascular leakiness in organs other than the skin might be present.

Staberg, B.; Worm, A.M.; Brodthagen, H.; Rossing, N.

1982-12-01

220

Effects of radiation on direct-drive laser target interaction  

NASA Astrophysics Data System (ADS)

Radiation may be useful for reducing laser imprint and Rayleigh-Taylor (RT) growth in direct-drive target pellets. We will discuss the important role of radiation in a proposed direct-drive X-ray preheated target concept(S.Bodner et al., Phys. Plasmas 5,1901(1998)). In this design, a high-Z coating surrounds a thin plastic coat, over a DT-wicked foam and on top of the DT fuel. Radiation effects will be examined and discussed in the context of this design. The soft X-ray radiation emitted during the foot of the laser pulse - at a few 10^12W/cm^2- preheats the foam ablator which contributes to the reduction of the RT instability. The ablator also stops the radiation, allowing the fuel to stay on a low adiabat. Radiation in the blow-off corona of the target establishes a long scalelength plasma. This separates the ablation region from the laser absorption region where the remaining defects in laser uniformity/pellet surface finish constitute the seed for hydrodynamic instabilities. However, when the pulse intensity rises, the pressure generated by the laser in combination with the changing opacity of the plasma causes the plasma to be pushed back toward the ablator. This is called a Radiative Plasma Structure (RPS)(J.Dahlburg et al., J.Q.S.R.T. 54,113(1995)). These RPS's are a potential problem because they may carry with them the imprint which was present in the low-density corona. We will show and discuss these various effects, as well as some of the experimental work(C.Pawley et al., this conference) under way in connection with this program. These experiments are essential in order to validate both the design concepts and the numerical models, which include on-line state-of-the-art atomic physics modeling(M.Klapisch et al.,Phys. Plasmas 5,1919(1998)).

Colombant, D. G.

1999-11-01

221

Effect of nuclear response functions in dark matter direct detection  

NASA Astrophysics Data System (ADS)

We examine the effect of nuclear response functions, as laid out by Fitzpatrick et al. [J. Cosmol. Astropart. Phys. 02 (2013) 004], on dark matter (DM) direct detection in the context of well-motivated UV completions, including electric and magnetic dipoles, anapole, spin-orbit, and pseudoscalar-mediated DM. Together, these encompass five of the six nuclear responses extracted from the nonrelativistic effective theory of Fitzpatrick et al. [J. Cosmol. Astropart. Phys. 02 (2013) 004] (with the sixth difficult to UV complete), with two of the six combinations corresponding to standard spin-independent and spin-dependent responses. For constraints from existing direct detection experiments, we find that only the COUPP constraint, due to its heavy iodine target with large angular momentum and an unpaired spin, and its large energy range sensitivity, is substantially modified by the new responses compared to what would be inferred using the standard form factors to model the energy dependence of the response. For heavy targets such as xenon and germanium, the behavior of the new nuclear responses as recoil energy increases can be substantially different from that of the standard responses, but this has almost no impact on the constraints derived from experiments such as LUX, XENON100, and CDMS since the maximum nuclear recoil energy detected in these experiments is relatively low. We simulate mock data for 80 and 250 GeV DM candidates utilizing the new nuclear responses to highlight how they might affect a putative signal, and find the new responses are most important for highly momentum-suppressed interactions such as the magnetic dipole or pseudoscalar-mediated interaction when the target is relatively heavy (such as xenon and iodine).

Gresham, Moira I.; Zurek, Kathryn M.

2014-06-01

222

The effect of flocculation on DRM direction and intensity  

NASA Astrophysics Data System (ADS)

Sedimentary rock records, being relatively more continuous than igneous records, are indispensable for studying past geomagnetic field variations. Sedimentary paleointensity studies rest upon the basic assumption that detrital remanent magnetization (DRM) is linearly related to the ambient field in which sediments acquired magnetization and paleosecular variation studies assume that the magnetization is parallel to the geomagnetic field. Yet, DRM is complicated. Factors other than the magnetic field such as particle size, shape, nature of sediments, hydrodynamic forces etc all affect how sediments get magnetized. In light of the many factors affecting DRM the key assumptions of linearity and parallelism are open to question. Inclination error has been known since the very early days of sedimentary paleomagnetism, yet the mechanisms that control it are poorly understood. Moreover, it has recently been suggested that even linearity may not always hold true. One of the most important control on DRM is now thought to be flocculation. Its role in controlling DRM magnitude has been explored but its influence on the directional properties of DRM is virtually unknown. In a series of laboratory experiments in different field and flocculation states we have confirmed the strong non-linearity of certain sedimentary systems. In addition, we have discovered a marked dependence of inclination error with the field strength and flocculation state. Our findings have serious implications for paleosecular variation studies using sediments, in particular from low salinity environments, such as fresh water lakes in which very small changes in salinity could result in very large changes in flocculation state and DRM acquisition.

Mitro, R.; Tauxe, L.

2007-12-01

223

Evaluating the Effect of Information Technology in Small Businesses  

ERIC Educational Resources Information Center

Information technology (IT) has become a strategic vehicle for small businesses to achieve and sustain their competitive advantage. Prior research has suggested that information technology plays an important role in the decision-making process. The purpose of this study is to examine the relationship between organizational IT performance and…

Newman, Peter

2010-01-01

224

A requiem for the USA Is small shareholder monitoring effective?  

Microsoft Academic Search

From 1986 to 1993, the United Shareholders Association (USA) provided a conduit through which small shareholders could unite and attempt to influence the governance of large US corporations. We show that the USA targeted large firms that underperformed the market, that its influence increased from 1990 to 1993, and that USA-Sponsored proposals were more successful when the target firm was

Deon Strickland; Kenneth W. Wiles; Marc Zenner

1996-01-01

225

Direct observation of the spin-dependent Peltier effect.  

PubMed

The Peltier coefficient describes the amount of heat that is carried by an electrical current when it passes through a material. When two materials with different Peltier coefficients are placed in contact with one another, the Peltier effect causes a net flow of heat either towards or away from the interface between them. Spintronics describes the transport of electric charge and spin angular momentum by separate spin-up and spin-down channels in a device. The observation that spin-up and spin-down charge transport channels are able to transport heat independently of each other has raised the possibility that spin currents could be used to heat or cool the interface between materials with different spin-dependent Peltier coefficients. Here, we report the direct observation of the heating and cooling of such an interface by a spin current. We demonstrate this spin-dependent Peltier effect in a spin-valve pillar structure that consists of two ferromagnetic layers separated by a non-ferromagnetic metal. Using a three-dimensional finite-element model, we extract spin-dependent Peltier coefficients in the range -0.9 to -1.3 mV for permalloy. The magnetic control of heat flow could prove useful for the cooling of nanoscale electronic components or devices. PMID:22306839

Flipse, J; Bakker, F L; Slachter, A; Dejene, F K; van Wees, B J

2012-03-01

226

Episodic acidification of small streams in the northeastern united states: Effects on fish populations  

USGS Publications Warehouse

As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau, Pennsylvania. In situ bioassays with brook trout (Salvelinus fontinalis) and a forage fish species (blacknose dace (Rhinichthys atratulus], mottled sculpin (Cottus bairdi), or slimy sculpin (Cottus cognatus), depending on the region) measured direct toxicity. Movements of individual brook trout, in relation to stream chemistry, were monitored using radiotelemetry. Electrofishing surveys assessed fish community status and the density and biomass of brook trout in each stream. During low flow, all streams except one had chemical conditions considered suitable for the survival and reproduction of most fish species (median pH 6.0-7.2 during low flow; inorganic Al 100-200 ??g/L. We conclude that episodic acidification can have long-term effects on fish communities in small streams.

Baker, J. P.; Van Sickle, J.; Gagen, C. J.; Dewalle, D. R.; Sharpe, W. E.; Carline, R. F.; Baldigo, B. P.; Murdoch, P. S.; Bath, D. W.; Kretser, W. A.; Simonin, H. A.; Wigington, Jr. , P. J.

1996-01-01

227

Biochemical studies of the multicopper oxidase (small laccase) from Streptomyces coelicolor using bioactive phytochemicals and site-directed mutagenesis  

PubMed Central

Summary Multicopper oxidases can act on a broad spectrum of phenolic and non-phenolic compounds. These enzymes include laccases, which are widely distributed in plants and fungi, and were more recently identified in bacteria. Here, we present the results of biochemical and mutational studies of small laccase (SLAC), a multicopper oxidase from Streptomyces coelicolor (SCO6712). In addition to typical laccase substrates, SLAC was tested using phenolic compounds that exhibit antioxidant activity. SLAC showed oxidase activity against 12 of 23 substrates tested, including caffeic acid, ferulic acid, resveratrol, quercetin, morin, kaempferol and myricetin. The kinetic parameters of SLAC were determined for 2,2?-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid), 2,6-dimethoxyphenol, quercetin, morin and myricetin, and maximum reaction rates were observed with myricetin, where kcat and Km values at 60°C were 8.1 (±?0.8) s?1 and 0.9 (±?0.3) mM respectively. SLAC had a broad pH optimum for activity (between pH?4 and 8) and temperature optimum at 60–70°C. It demonstrated remarkable thermostability with a half-life of over 10?h at 80°C and over 7?h at 90°C. Site-directed mutagenesis revealed 17 amino acid residues important for SLAC activity including the 10 His residues involved in copper coordination. Most notably, the Y229A and Y230A mutant proteins showed over 10-fold increase in activity compared with the wild-type SLAC, which was correlated to higher copper incorporation, while kinetic analyses with S929A predicts localization of this residue near the meta-position of aromatic substrates. Funding Information Funding for this research was provided by the Government of Ontario for the project ‘FFABnet: Functionalized Fibre and Biochemicals’ (ORF-RE-05-005), and the Natural Sciences and Engineering Research Council of Canada.

Sherif, Mohammed; Waung, Debbie; Korbeci, Bihter; Mavisakalyan, Valentina; Flick, Robert; Brown, Greg; Abou-Zaid, Mamdouh; Yakunin, Alexander F; Master, Emma R

2013-01-01

228

Effect of hypocholesterolemia on cholesterol synthesis in small intestine of diabetic rats  

Microsoft Academic Search

Studies by our and other laboratories have demonstrated that cholesterol synthesis is increased in the small intestine of insulinopenic diabetic animals. In normal animals, many factors have been shown to regulate cholesterol synthesis in the small intestine, including changes in plasma cholesterol levels. The purpose of this study was to determine the effect of lowering plasma cholesterol levels on small

K. R. Feingold; A. H. Moser

1987-01-01

229

Magnetic field and symmetry effects in small quantum dots  

NASA Astrophysics Data System (ADS)

Shell phenomena in small quantum dots with a few electrons under a perpendicular magnetic field are discussed within a simple model. It is shown that various kinds of shell structures, which occur at specific values for the magnetic field lead to a disappearance of the orbital magnetization for particular magic numbers for noninteracting electrons in small quantum dots. Including the Coulomb interaction between two electrons, we found that the magnetic field gives rise to dynamical symmetries of a three-dimensional axially symmetric two-electron quantum dot with a parabolic confinement. These symmetries manifest themselves as near-degeneracy in the quantum spectrum at specific values of the magnetic field and are robust at any strength of the electron-electron interaction. A remarkable agreement between experimental data and calculations exhibits the important role of the thickness for the two-electron quantum dot for analysis of ground state transitions in a perpendicular magnetic field.

Nazmitdinov, R. G.

2009-01-01

230

Naming game on small-world networks with geographical effects  

NASA Astrophysics Data System (ADS)

The naming game model characterizes the main evolutionary features of languages or more generally of communication systems. Very recently, the combination of complex networks and the naming game has received much attention and the influences of various topological properties on the corresponding dynamical behavior have been widely studied. In this paper, we investigate the naming game on small-world geographical networks. The small-world geographical networks are constructed by randomly adding links to two-dimensional regular lattices, and it is found that the convergence time is a nonmonotonic function of the geographical distance of randomly added shortcuts. This phenomenon indicates that, although a long geographical distance of the added shortcuts favors consensus achievement, too long a geographical distance of the added shortcuts inhibits the convergence process, making it even slower than the moderates.

Liu, Run-Ran; Jia, Chun-Xiao; Yang, Han-Xin; Wang, Bing-Hong

2009-09-01

231

Small-crack effects in high-strength aluminum alloys  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration and the Chinese Aeronautical Establishment participated in a Fatigue and Fracture Mechanics Cooperative Program. The program objectives were to identify and characterize crack initiation and growth of small cracks (10 microns to 2 mm long) in commonly used US and PRC aluminum alloys, to improve fracture mechanics analyses of surface- and corner-crack configurations, and to develop improved life-prediction methods. Fatigue and small-crack tests were performed on single-edgenotch tension (SENT) specimens and large-crack tests were conducted on center-crack tension specimens for constant-amplitude (stress ratios of -1, 0, and 0.5) and Mini-TWIST spectrum loading. The plastic replica method was used to monitor the initiation and growth of small fatigue cracks at the semicircular notch. Crack growth results from each laboratory on 7075-T6 bare and LC9cs clad aluminum alloys agreed well and showed that fatigue life was mostly crack propagation from a material defect (inclusion particles or void) or from the cladding layer. Finite-element and weight-function methods were used to determine stress intensity factors for surface and corner cracks in the SENT specimens. Equations were then developed and used in a crack growth and crack-closure model to correlate small- and large-crack data and to make life predictions for various load histories. The cooperative program produced useful experimental data and efficient analysis methods for improving life predictions. The results should ultimately improve aircraft structural reliability and safety.

Newman, J. C., Jr.; Wu, X. R.; Venneri, S. L.; Li, C. G.

1994-01-01

232

Effect of Interfaces on Small, Starved Marine Bacteria  

PubMed Central

The copiotrophic marine Vibrio sp. strain DW1, shown previously in batch culture to increase in numbers at the onset of starvation and then to form viable small cells with low endogenous respiration, appears to have a survival advantage at interfaces. Vibrio sp. strain DW1 behaved differently at interfaces compared with the aqueous phase under starvation conditions: (i) small cells were observed at an air-water interface without nutrients, (ii) nutrients added to the air-water interface quickly produced larger cells at the surface, (iii) motility persisted many hours longer at the solid-water interface of a dialysis membrane in a microchamber at the onset of starvation, and (iv) regrowth and division at the solid-liquid interface occurred quickly and at nutrient concentrations too low to permit growth in the aqueous phase. It was concluded that, if small starved cells from copiotrophic bacteria can reach an interface, additional survival mechanisms become available to them: (i) interfaces constitute areas of favorable nutrient conditions, and (ii) interfaces lacking a sufficient amount of nutrient, nevertheless, trigger cells to become smaller, thus increasing their surface/volume ratio and the packing density. Images

Kjelleberg, Staffan; Humphrey, Beverley A.; Marshall, Kevin C.

1982-01-01

233

Environmental effects of small-arms ranges. Final report  

SciTech Connect

This report attempts to locate and evaluate information in the following general subject areas: contaminant concentrations normally present at sites, normal background levels of identified contaminants, toxicity information on identified contaminants, regulatory controls and considerations, and identification and classification of small arms ranges that are controlled by the Navy. This report consists of a literature search of data and studies of environmental contamination at small arms ranges; geochemical equilibria modeling to determine the fate of lead, copper, and zinc in the environment; and a survey to gather information on the Navy's small arms ranges. Soils in the impact and target berms have been found to have elevated levels of metals including lead, copper, and zinc, causing the soils to be classified as hazardous waste. Of these, lead is the only metal regulated by the Resource Conservation and Recovery Act. Elevated levels of metals have also been found in the soils and vegetation in large areas behind and adjacent to the target and impact berms.

Heath, J.C.; Karr, L.; Novstrup, V.; Nelson, B.; Ong, S.K.

1991-10-01

234

Mesenteric cysts associated with recurrent small-bowel volvulus: cause or effect?  

PubMed

Recurrent small-bowel volvulus is a state of recurrent intermittent or long-standing persistent twisting of small-bowel loops around its mesentery. The association of mesenteric cysts with recurrent small-bowel volvulus as the cause or effect is a much debated issue in the literature. We report two cases of mesenteric lymphangioma and one case of enteric duplication cyst seen in association with recurrent small-bowel volvulus of long duration in absence of malrotation. PMID:22986751

Prabhu, Shailesh M; Anand, Rama; Narula, Mahender K; Shetty, Gurucharan S; Udiya, Alok K; Chauhan, Udit; Shukla, Shailaja; Grover, Jitendra Kumar

2012-12-01

235

Recent Advances in the Discovery of Small Molecules Targeting Exchange Proteins Directly Activated by cAMP (EPAC).  

PubMed

3',5'-Cyclic adenosine monophosphate (cAMP) is a pivotal second messenger that regulates numerous biological processes under physiological and pathological conditions, including cancer, diabetes, heart failure, inflammation, and neurological disorders. In the past, all effects of cAMP were initially believed to be mediated by protein kinase A (PKA) and cyclic nucleotide-regulated ion channels. Since the discovery of exchange proteins directly activated by cyclic adenosine 5'-monophosphate (EPACs) in 1998, accumulating evidence has demonstrated that the net cellular effects of cAMP are also regulated by EPAC. The pursuit of the biological functions of EPAC has benefited from the development and applications of a growing number of pharmacological probes targeting EPACs. In this review, we seek to provide a concise update on recent advances in the development of chemical entities including various membrane-permeable analogues of cAMP and newly discovered EPAC-specific ligands from high throughput assays and hit-to-lead optimizations. PMID:24256330

Chen, Haijun; Wild, Christopher; Zhou, Xiaobin; Ye, Na; Cheng, Xiaodong; Zhou, Jia

2014-05-01

236

Effect of reabsorbed recombination radiation on the saturation current of direct gap p-n junctions  

NASA Technical Reports Server (NTRS)

The application of the radiative transfer theory for semiconductors to p-n homojunctions subject to low level injection conditions is discussed. By virtue of the interaction of the radiation field with free carriers across the depletion layer, the saturation current density in Shockley's expression for the diode current is reduced at high doping levels. The reduction, due to self-induced photon generation, is noticeable for n-type material owing to the small electron effective mass in direct band-gap III-V compounds. The effect is insignificant in p-type material. At an equilibrium electron concentration of 2 x 10 to the 18th/cu cm in GaAs, a reduction of the saturation current density by 15 percent is predicted. It is concluded that realistic GaAs p-n junctions possess a finite thickness.

Von Roos, O.; Mavromatis, H.

1984-01-01

237

Effect of Ultrasonic Vibration on Direct Reaction Between Solid Ti Powders and Liquid Al  

NASA Astrophysics Data System (ADS)

In-situ blocky Al3Ti particles can be synthesized by direct reaction between solid Ti powders and liquid Al in terms of reaction-peeling model. In this research, the effect of high-intensity ultrasonic vibration on the reaction was investigated by means of immersing the ultrasonic radiator in the Al melt at 1003 K (730 °C) during the fabricating process. The results show that the thickness of Al3Ti reaction layers can be decreased to range from 2 to 3 ?m, and the sizes of most of Al3Ti particles can be reduced in the ultrasonic fields as well, with the average size ranging from 2 to 3 ?m. The two changes are both attributed to the effects of external forces produced in the ultrasonic fields. Thereby, small blocky Al3Ti particles can be peeled off from the reaction layer more quickly, making reaction layers to become thinner and the particles smaller.

Liu, Z. W.; Wang, X. M.; Han, Q. Y.; Li, J. G.

2014-02-01

238

Direct and indirect effects of UV-B exposure on litter decomposition: a meta-analysis.  

PubMed

Ultraviolet-B (UV-B) exposure in the course of litter decomposition may have a direct effect on decomposition rates via changing states of photodegradation or decomposer constitution in litter while UV-B exposure during growth periods may alter chemical compositions and physical properties of plants. Consequently, these changes will indirectly affect subsequent litter decomposition processes in soil. Although studies are available on both the positive and negative effects (including no observable effects) of UV-B exposure on litter decomposition, a comprehensive analysis leading to an adequate understanding remains unresolved. Using data from 93 studies across six biomes, this introductory meta-analysis found that elevated UV-B directly increased litter decomposition rates by 7% and indirectly by 12% while attenuated UV-B directly decreased litter decomposition rates by 23% and indirectly increased litter decomposition rates by 7%. However, neither positive nor negative effects were statistically significant. Woody plant litter decomposition seemed more sensitive to UV-B than herbaceous plant litter except under conditions of indirect effects of elevated UV-B. Furthermore, levels of UV-B intensity significantly affected litter decomposition response to UV-B (P<0.05). UV-B effects on litter decomposition were to a large degree compounded by climatic factors (e.g., MAP and MAT) (P<0.05) and litter chemistry (e.g., lignin content) (P<0.01). Results suggest these factors likely have a bearing on masking the important role of UV-B on litter decomposition. No significant differences in UV-B effects on litter decomposition were found between study types (field experiment vs. laboratory incubation), litter forms (leaf vs. needle), and decay duration. Indirect effects of elevated UV-B on litter decomposition significantly increased with decay duration (P<0.001). Additionally, relatively small changes in UV-B exposure intensity (30%) had significant direct effects on litter decomposition (P<0.05). The intent of this meta-analysis was to improve our understanding of the overall effects of UV-B on litter decomposition. PMID:23818993

Song, Xinzhang; Peng, Changhui; Jiang, Hong; Zhu, Qiuan; Wang, Weifeng

2013-01-01

239

Metastable structures and size effects in small group dynamics  

PubMed Central

In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: (1) they emerge as a consequence of the natural tendency of (both conscious and unconscious) emotions to combine into structured group patterns; (2) they have a certain degree of stability in time; (3) they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; (4) they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical “leadership” pattern, and in “cognitive” terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e., the group behaves “as if” it was assuming that). Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: (1) are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? (2) can these states be differentiated in structural terms? (3) to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical setting.

Lauro Grotto, Rosapia; Guazzini, Andrea; Bagnoli, Franco

2014-01-01

240

Template-directed synthesis of a small molecule-antisense conjugate targeting an mRNA structure.  

PubMed

The targeting of structural features in mRNA with specificity remains a great chemical challenge. A hairpin structure near exon 10 in the pre-mRNA encoding the tau protein controls its splicing, and dementia-causing mutations that disrupt this structure increase exon 10 splicing. We previously reported the discovery of small molecules, mitoxantrone (MTX) and analogs, which bind to the tau RNA hairpin structure and the design of bipartite antisense oligonucleotides (ASOs) that simultaneously bind to the discontinuous sequences that flank this hairpin. Herein we report the synthesis of a bipartite ASO conjugated to MTX using the tau RNA hairpin and flanking sequences as a template. A set of six MTX analogs, each containing a linker-azide, and a set of ten bipartite ASOs, each containing a branched linker-alkyne, were synthesized and tested in combinatorial fashion for their ability to conjugate in the presence or absence of template RNA. A single template-dependent MTX-ASO conjugate was identified from among the 60 reaction mixtures, demonstrating that the MTX and ASO precursors could simultaneously bind the RNA template and allow proper positioning of azide and alkyne for 1,3-cycloaddition. While the MTX-ASO conjugate proved too cytotoxic for cell-based assays, the conjugate inhibited tau exon 10 splicing under cell-free conditions more effectively than MTX or bipartite ASO alone. PMID:24691171

Liu, Yang; Rodriguez, Lilia; Wolfe, Michael S

2014-06-01

241

Direct measurement of Lorentz transformation with Doppler effects  

NASA Astrophysics Data System (ADS)

For space science and astronomy the fundamentality of one-way velocity of light (OWVL) is selfevident. The measurement of OWVL (distance/interval) and the clock synchronization with light-signal transfer make a logical circulation. This means that OWVL could not be directly measured but only come indirectly from astronomical method (Romer's Io eclipse and Bradley's sidereal aberration), furthermore, the light-year by definitional OWVL and the trigonometry distance with AU are also un-measurable. For to solve this problem two methods of clock synchronization were proposed: The direct method is that at one end of dual-speed transmissionline with single clock measure the arriving-time difference of longitudinal wave and transverse wave or ordinary light and extraordinary light, again to calculate the collective sending-time of two wave with Yang's /shear elastic-modulus ratio (E/k) or extraordinary/ordinary light refractive-index ratio (ne/no), which work as one earthquake-station with single clock measures first-shake time and the distance to epicenter; The indirect method is that the one-way wavelength l is measured by dual-counters Ca and Cb and computer's real-time operation of reading difference (Nb - Na) of two counters, the frequency f is also simultaneously measured, then l f is just OWVL. Therefore, with classical Newtonian mechanics and ether wave optics, OWVL can be measured in the Galileo coordinate system with an isotropic length unit (1889 international meter definition). Without any hypotheses special relativity can entirely establish on the metrical results. When a certain wavelength l is defined as length unit, foregoing measurement of one-way wavelength l will become as the measurement of rod's length. Let a rigidity-rod connecting Ca and Cb moves relative to lamp-house with velocity v, rod's length L = (Nb - Na) l will change follow v by known Doppler effect, i.e., L(q) =L0 (1+ (v/c) cos q), where L0 is the proper length when v= 0, v• r = v cos q, r is the unit vector from lamphouse point to counters. Or: L (0) L (pi) =L0 (1+(v/c)) L0 (1 - (v/c)) =L0 2 y2 =L2 Or: L ? [L(0)L(pi)]1/2 =L0 y , which y ? (1 - (v/c)2 )1/2 is just Fitzgerald-Lorentzian contraction-factor. Also, when a light-wave period p is defined as time unit, from Doppler's frequency-shift the count N with p of one period T of moving-clock is: T(q) = N(q) p = T0 /(1+(v/c) cos q) Or: T ? (T(0) T(pi))1/2 = T 0 /y , where T0 is the proper period when v = 0, which is just the moving-clock-slower effect. Let r from clock point to lamp-house ((v/c) symbol reverse), Doppler formula in the usual form is: f (q) = 1/T(q) = f0 (1 - (v/c) cos q). Therefore, Lorentz transformation is the square root average of positive and negative directions twice metrical results of Doppler's frequency-shift, which Doppler's once items ( positive and negative v/c ) are counteract only residual twice item (v/c)2 (relativity-factor). Then Lorentz transformation can be directly measured by Doppler's frequency-shift method. The half-life of moving mu-meson is statistical average of many particles, the usual explanation using relativity-factor y is correct. An airship moving simultaneously along contrary directions is impossible, which makes that the relativity-factor y and the twin-paradox are inexistent in the macroscopical movement. Thereby, in the navigations of airship or satellite only use the measurement of Doppler's frequency-shift but have no use for Lorentz transformation.

Chen, Shao-Guang

242

Small mammals cause non-trophic effects on habitat and associated snails in a native system.  

PubMed

Legacy effects occur when particular species or their interactions with others have long-lasting impacts, and they are increasingly recognized as important determinants of ecological processes. However, when such legacy effects have been explicitly explored, they most often involve the long-term direct effects of species on systems, as opposed to the indirect effects. Here, we explore how a legacy of small mammal exclusion on the abundance of a shrub, bush lupine (Lupinus arboreus), influences the abundance of a native land snail (Helminthoglypta arrosa) in coastal prairie and dune habitats in central California. The factors that limit populations of land snails are very poorly known despite the threats to the persistence of this group of species. In grasslands, prior vole (Microtus californicus) exclusion created long-lasting gains in bush lupine abundance, mediated through the seedbank, and was associated with increased snail numbers (10×) compared to control plots where mammals were never excluded. Similar plots in dune habitat showed no difference in snail numbers due to previous mammal exclusion. We tested whether increased competition for food, increased predation, and/or lower desiccation explained the decline in snail numbers in plots with reduced lupine cover. Tethering experiments supported the hypothesis that voles can have long-lasting impacts as ecosystem engineers, reducing woody lupine habitat required for successful aestivation by snails. These results add to a growing list of studies that have found that non-trophic interactions can be limiting to invertebrate consumers. PMID:21691854

Huntzinger, Mikaela; Karban, Richard; Maron, John L

2011-12-01

243

Small Sample Size Effects in Statistical Pattern Recognition: Recommendations for Practitioners  

Microsoft Academic Search

The effects of sample size on feature selection and error estimation for several types of classifiers are discussed. The focus is on the two-class problem. Classifier design in the context of small design sample size is explored. The estimation of error rates under small test sample size is given. Sample size effects in feature selection are discussed. Recommendations for the

Sarunas Raudys; Anil K. Jain

1991-01-01

244

Facet effect manifestation during crystallization from small volumes of solution in melt  

NASA Astrophysics Data System (ADS)

Manifestations of the facet effect are possible during the thermomigration of discrete inclusions of the solution of a growing crystal material in small volumes of the melt of a solvent metal. Similar to the case of a bulk crystal growth, the facet effect in small volumes is related to the nonequilibrium trapping of impurity by singular regions of the crystallization front.

Gershanov, V. Yu.; Garmashov, S. I.

2011-07-01

245

Electronic effects on the melting of small gallium clusters  

NASA Astrophysics Data System (ADS)

Motivated by experimental reports of higher-than-bulk melting temperatures in small gallium clusters, we perform first-principles molecular dynamics simulations of Ga20 and Ga20+ using parallel tempering in the microcanonical ensemble. The respective specific heat (CV) curves, obtained using the multiple histogram method, exhibit a broad peak centered at approximately 740 and 610 K--well above the melting temperature of bulk gallium (303 K) and in reasonable agreement with experimental data for Ga20+. Assessment of atomic mobility confirms the transition from solid-like to liquid-like states near the CV peak temperature. Parallel tempering molecular dynamics simulations yield low-energy isomers that are ~0.1 eV lower in energy than previously reported ground state structures, indicative of an energy landscape with multiple, competing low-energy morphologies. Electronic structure analysis shows no evidence of covalent bonding, yet both the neutral and charged clusters exhibit greater-than-bulk melting temperatures.

Steenbergen, K. G.; Schebarchov, D.; Gaston, N.

2012-10-01

246

Assessing the possible direct effect of birth weight on childhood blood pressure: a sensitivity analysis.  

PubMed

To estimate the possible direct effect of birth weight on blood pressure, it is conventional to condition on the mediator, current weight. Such conditioning can induce bias. Our aim was to assess the potential biasing effect of U, an unmeasured common cause of current weight and blood pressure, on the estimate of the controlled direct effect of birth weight on blood pressure, with the help of sensitivity analyses. We used data from a school-based study conducted in Switzerland in 2005-2006 (n = 3,762; mean age = 12.3 years). A small negative association was observed between birth weight and systolic blood pressure (linear regression coefficient ?bw = -0.3 mmHg/kg, 95% confidence interval: -0.9, 0.3). The association was strengthened upon adjustment for current weight (?bw|C = -1.5 mmHg/kg, 95% confidence interval: -2.1, -0.9). Sensitivity analyses revealed that the negative conditional association was explained by U only if U was relatively strongly associated with blood pressure and if there was a large difference in the prevalence of U between low-birth weight and normal-birth weight children. This weakens the hypothesis that the negative relationship between birth weight and blood pressure arises only from collider-stratification bias induced by conditioning on current weight. PMID:24186972

Chiolero, Arnaud; Paradis, Gilles; Kaufman, Jay S

2014-01-01

247

DNA damage induced by the direct effect of radiation  

NASA Astrophysics Data System (ADS)

We have studied the nature of DNA damage induced by the direct effect of radiation. The yields of single- (SSB) and double-strand breaks (DSB), base lesions and clustered damage were measured using the agarose gel electrophoresis method after exposing to various kinds of radiations to a simple model DNA molecule, fully hydrated closed-circular plasmid DNA (pUC18). The yield of SSB does not show significant dependence on linear energy transfer (LET) values. On the other hand, the yields of base lesions revealed by enzymatic probes, endonuclease III (Nth) and formamidopyrimidine DNA glycosylase (Fpg), which excise base lesions and leave a nick at the damage site, strongly depend on LET values. Soft X-ray photon (150 kVp) irradiation gives a maximum yield of the base lesions detected by the enzymatic probes as SSB and clustered damage, which is composed of one base lesion and proximate other base lesions or SSBs. The clustered damage is visualized as an enzymatically induced DSB. The yields of the enzymatically additional damages strikingly decrease with increasing levels of LET. These results suggest that in higher LET regions, the repair enzymes used as probes are compromised because of the dense damage clustering. The studies using simple plasmid DNA as a irradiation sample, however, have a technical difficulty to detect multiple SSBs in a plasmid DNA. To detect the additional SSBs induced in opposite strand of the first SSB, we have also developed a novel technique of DNA-denaturation assay. This allows us to detect multiply induced SSBs in both strand of DNA, but not induced DSB.

Yokoya, A.; Shikazono, N.; Fujii, K.; Urushibara, A.; Akamatsu, K.; Watanabe, R.

2008-10-01

248

Hydrogen effects on directional solidification of Te-doped cast irons  

SciTech Connect

In a recent study, directional solidification experiments were employed with increasing and decreasing velocities to evaluate the effect of small Te additions on the transition velocities between gray to white cast irons during acceleration, V{sub g-w}, and the reverse transition (white to gray) during deceleration, V{sub w-g}. The irons had a hypoeutectic composition of 3.4 wt pct C, 2 wt pct Si and were doped with 0.1 wt pct Te. In an extension of this work to lower Si levels, a hypoeutectic iron of 3.9 wt pct C, 1 wt pct Si + 0.05 wt pct Te, an important discovery was made involving the effect of H on the transition velocities. In conclusion, the authors have made the following discoveries: (1) small additions of H to the atmosphere present in directional solidification experiments of Te-doped cast irons have a large effect on the gray-white and white-gray transition velocities; (2) addition of 10% H to the atmosphere allows growth of white cast iron at rates down to 1 and 2.5 {micro}sm/s in irons containing 1 and 2 wt pct Si, respectively; (3) it appears that the action of the H is to reduce compounds of Te, most likely oxides, thereby allowing more Te to remain in liquid solution and to adsorb on the graphite/liquid iron growth front interfaces; this, in turn, reduces the graphite growth kinetics and permits white iron growth to dominate.

Park, J.S.; Verhoeven, J.D. [Iowa State Univ., Ames, IA (United States). Dept. of Materials Science]|[Ames Lab., IA (United States)

1996-02-01

249

Impact of Mineral Dust Direct Radiative Effect on Mediterranean Climate  

NASA Astrophysics Data System (ADS)

Saharan desert is an important component of the Mediterranean climate system. Meteorological conditions are the driving factor of the emissions and transport of dust from Sahara, so that climate change can affect the mineral dust sources and its transport pathways. Dust also affects the Mediterranean climate by modifying its radiative budget at regional scale. In this study, the effect of a future climate projection on radiative effect in the Mediterranean is analyzed. Three 10-year time periods (1991-2000, 2041-2050, and 2091-2100) were simulated with the regional climate model RegCM-4.1.1 in order to quantify the changes in direct radiative forcing and related impacts on temperature and precipitations. The model domain covers the entire Mediterranean Basin. The horizontal resolution is 27x27 km2 and grid number is 128x256 with 18 vertical layers from surface to10 hPa. Initial and boundary conditions were obtained from ECHAM5 simulations of the A1B scenario. Two sets of simulations were performed, with and without mineral dust. Monthly average precipitation and temperature data over 10 years are analyzed on both seasonal and annual time averages. Taylor diagrams (Taylor 2001) that compute the root mean square difference (RMSD), variability and pattern correlation between the model outputs of no-dust simulations and gridded datasets of Climate Research Unit (CRU) observations, allow us to assess the overall model performance. Short wave net radiation at surface is decreasing up to 20 W/m2 over the source regions and 8 W/m2 over Mediterranean Sea and South Europe and 3 W/m2 over the source region at the top of atmosphere since mineral dust has scattering feature. Also dust causes a decrease in mean temperature around 0.2 Cº over Europe and 0.5 Cº over the African continent for the period 1991-2000. A similar impact is found also for the 2041-2050. Smaller temperature changes are simulated for the end of the 21st century. Finally, our results suggest that precipitations are not changing significantly for the 3 periods.

Agacayak, Tugba; Kindap, Tayfun; Unal, Alper; Pozzoli, Luca; Mallet, Marc; Bozkurt, Deniz; Solmon, Fabien; Dulac, Francois; Karaca, Mehmet

2014-05-01

250

Direct effects of phosphorylation on the preferred backbone conformation of peptides: a nuclear magnetic resonance study.  

PubMed Central

Control of protein activity by phosphorylation appears to work principally by inducing conformational change, but the mechanisms so far reported are dependent on the structural context in which phosphorylation occurs. As the activity of many small peptides is also regulated by phosphorylation, we decided to investigate possible direct consequences of this on the preferred backbone conformation. We have performed 1H nuclear magnetic resonance (NMR) experiments with short model peptides of the pattern Gly-Ser-Xaa-Ser, where Xaa represents Ser, Thr, or Tyr in either phosphorylated or unphosphorylated form and with either free or blocked amino and carboxy termini. The chemical shifts of amide protons and the 3JNH-Halpha coupling constants were estimated from one-dimensional and two-dimensional scalar correlated spectroscopy (COSY) spectra at different pH values. The results clearly indicate a direct structural effect of serine and threonine phosphorylation on the preferred backbone dihedrals independent of the presence of charged groups in the surrounding sequence. Tyrosine phosphorylation does not induce such a charge-independent effect. Additionally, experiments with p-fluoro- and p-nitro-phenylalanine-containing peptides showed that the mere presence of an electronegative group on the aromatic ring of tyrosine does not produce direct structural effects. In the case of serine and threonine phosphorylation a strong dependence of the conformational shift on the protonation level of the phosphoryl group could be observed, showing that phosphorylation induces the strongest effect in its dianionic, i.e., physiological, form. The data reveal a hitherto unknown mechanism that may be added to the repertoire of conformational control of peptides and proteins by phosphorylation.

Tholey, A; Lindemann, A; Kinzel, V; Reed, J

1999-01-01

251

Small power plants; Seminar on Small Power Plants - Technology and Cost Effectiveness, Technische Universitaet Wien, Vienna, Austria, January 15, 16, 1981, Reports  

NASA Astrophysics Data System (ADS)

Progress in the production of small power plants is discussed. The topics considered include small power plants in Switzerland, the BRD, and Hungary, and the use of nontraditional energy sources in the USSR. The economic aspects of small power plants are examined, and direct and indirect means of producing solar energy are studied. The direct forms include the Austrian 10-kW plant, while the indirect forms discussed include water and wind power, biomass, hay, biogas, and wood. Unit power plants are discussed along with geothermal energy, heat pumps, the role of systems analysis, and the impact of energy production on the environment.

Bauer, L.

252

The direct way of indirect bonding--the combined effect.  

PubMed

The placement of orthodontic bonded brackets may be accomplished by either a direct or indirect technique. Most orthodontists will agree that brackets can be positioned more accurately on study casts than directly on teeth in the mouth. And, also direct bonding is more demanding to the orthodontist. Yet, very few orthodontists routinely use an indirect bonding technique. The reasons commonly given for not using the indirect method are difficulty in achieving consistent and predictable adhesion to the teeth, excess of composite around the bracket margins, failure to get all the brackets to adhere to the teeth e the expense of the materials. These disadvantages can be overcome by a new simplified method of bonding outlined in this article; additionally it has advantages of direct bonding also. PMID:24358650

Gayake, Prasad Vinayakrao; Chitko, Shrikant S; Sutrave, Nagdeepak; Gaikwad, Pallavi M

2013-01-01

253

Small high-yielding binary Ti vectors pLSU with co-directional replicons for Agrobacterium tumefaciens-mediated transformation of higher plants.  

PubMed

Small high-yielding binary Ti vectors of Agrobacterium tumefaciens were constructed to increase the cloning efficiency and plasmid yield in Escherichia coli and A. tumefaciens for transformation of higher plants. We reduced the size of the binary vector backbone to 4566bp with ColE1 replicon (715bp) for E. coli and VS1 replicon (2654bp) for A. tumefaciens, a bacterial kanamycin resistance gene (999bp), and the T-DNA region (152bp). The binary Ti vectors with the truncated VS1 replicon were stably maintained with more than 98% efficiency in A. tumefaciens without antibiotic selection for 4 days of successive transfers. The transcriptional direction of VS1 replicon can be the same as that of ColE1 replicon (co-directional transcription), or opposite (head-on transcription) as in the case of widely used vectors (pPZP or pCambia). New binary vectors with co-directional transcription yielded in E. coli up to four-fold higher transformation frequency than those with the head-on transcription. In A. tumefaciens the effect of co-directional transcription is still positive in up to 1.8-fold higher transformation frequency than that of head-on transcription. Transformation frequencies of new vectors are over six-fold higher than those of pCambia vector in A. tumefaciens. DNA yields of new vectors were three to five-fold greater than pCambia in E. coli. The proper functions of the new T-DNA borders and new plant selection marker genes were confirmed after A. tumefaciens-mediated transformation of tobacco leaf discs, resulting in virtually all treated leaf discs transformed and induced calli. Genetic analysis of kanamycin resistance trait among the progeny showed that the kanamycin resistance and sensitivity traits were segregated into the 3:1 ratio, indicating that the kanamycin resistance genes were integrated stably into a locus or closely linked loci of the nuclear chromosomal DNA of the primary transgenic tobacco plants and inherited to the second generation. PMID:22404832

Lee, Seokhyun; Su, Guiying; Lasserre, Eric; Aghazadeh, Monty Arta; Murai, Norimoto

2012-05-01

254

Effects of Turbulence on Self-sustained Combustion in Premixed Flame Kernels: A Direct Numerical Simulation (DNS) Study  

Microsoft Academic Search

The effects of mean flame radius and turbulence on self-sustained combustion of turbulent premixed spherical flames in decaying\\u000a turbulence have been investigated using three-dimensional direct numerical simulations (DNS) with single step Arrhenius chemistry.\\u000a Several flame kernels with different initial radius or initial turbulent field have been studied for identical conditions\\u000a of thermo-chemistry. It has been found that for very small

M. Klein; N. Chakraborty; R. S. Cant

2008-01-01

255

FATE AND EFFECTS OF ATRAZINE IN SMALL AQUATIC MICROCOSMS  

EPA Science Inventory

Using continuous flow aquaria or static beakers and mixed biota communities, the fate and effects of atrazine were determined and the resilience of the systems after the removal of the compound were evaluated. In addition, the response of the different test systems to the herbici...

256

Effects of Preliminary Directions on Table- and Graph-Using Proficiencies of Upper Elementary Schoolers.  

ERIC Educational Resources Information Center

The effects of cursory preliminary directions on the use of numerical tables, bar graphs, and line graphs by 288 fourth and sixth graders were investigated. Participants received no directions, written directions only, or written directions with assistance where necessary. The undirected table and bar graph users performed moderately well. Their…

Follettie, Joseph F.

257

Physical and chemical effects of direct aqueous advanced oxidation processing on green sand foundry mold materials  

NASA Astrophysics Data System (ADS)

Iron foundries using the common green sand molding process have increasingly been incorporating aqueous advanced oxidation (AO) systems to reduce the consumption of sand system bentonite clay and coal raw materials by and to decrease their volatile organic compound (VOC) emissions. These AO systems typically use a combination of sonication, ozone aeration, and hydrogen peroxide to treat and recycle slurries of sand system baghouse dust, which is rich in clay and coal. While the overall effects of AO on raw material consumption and organic emissions are known, the mechanisms behind these effects are not well understood. This research examined the effects of bench-scale direct aqueous AO processing on green sand mold materials at the micro level. Bench-scale AO processing, including acoustic sonication, ozone/oxygen aeration, and hydrogen peroxide dramatically decreased the particle sizes of both western bentonite and foundry sand system baghouse dust. Bench-scale AO processing was shown to effectively separate the clay material from the larger silica and coal particles and to extensively break up the larger clay agglomerates. The acoustic sonication component of AO processing was the key contributor to enhanced clay recovery. Acoustic sonication alone was slightly more effective than combined component AO in reducing the particle sizes of the baghouse dust and in the recovery of clay yields in the supernatant during sedimentation experiments. Sedimentation separation results correlated well with the increase in small particle concentrations due to AO processing. Clay suspension viscosity decreased with AO processing due to enhanced dispersion of the particles. X-ray diffraction of freeze-dried baghouse dust indicated that AO processing does not rehydrate calcined montmorillonite and does not increase the level of interlayer water hydration in the dry clays. Zeta potential measurements indicated that AO processing also does not produce any large changes in the surface charge of the small clay particles upon AO treatment.

Clobes, Jason Kenneth

258

Small Al clusters. I - The effect of basis set and correlation on the geometry of small Al clusters  

NASA Technical Reports Server (NTRS)

A detailed study is presented of the basis set requirements and effects of correlation on the geometry and structure of small Al(n) clusters n = 2, 4, and 13. An effective core potential (ECP) is developed from the Huzinaga basis which accurately reproduces the all-electron results. It is found that depolarization functions are very important in computing the bond length, and that the bond contraction obtained is about as large for a 13-atom cluster as for the Al(4) rhombus structure. With d functions on each center in Al(13), a bond distance shorter than the bulk is obtained, as expected. The inclusion of correlation in Al(4) is found to be less important than the addition of polarization functions for determining the bond length, but increases substantially the calculated atomization energy. These calibration calculations allow an accurate treatment for Al(n) clusters to be designed.

Bauschlicher, Charles W., Jr.; Pettersson, Lars G. M.

1987-01-01

259

Dry paths effectively reduce road mortality of small and medium-sized terrestrial vertebrates.  

PubMed

Wildlife passages are widely used mitigation measures designed to reduce the adverse impacts of roads on animals. We investigated whether road kills of small and medium-sized terrestrial vertebrates can be reduced by constructing dry paths adjacent to streams that pass under road bridges. The study was carried out in southern Finland during the summer of 2008. We selected ten road bridges with dry paths and ten bridges without them, and an individual dry land reference site for each study bridge on the basis of landscape and traffic features. A total of 307 dead terrestrial vertebrates were identified during the ten-week study period. The presence of dry paths decreased the amount of road-killed terrestrial vertebrates (Poisson GLMM; p < 0.001). That was true also when considering amphibians alone (p < 0.001). The evidence on road-kills on mammals was not such clear. In the mammal model, a lack of dry paths increased the amount of carcasses (p = 0.001) whereas the number of casualties at dry path bridges was comparable with dry land reference sites. A direct comparison of the dead ratios suggests an average efficiency of 79% for the dry paths. When considering amphibians and mammals alone, the computed effectiveness was 88 and 70%, respectively. Our results demonstrate that dry paths under road bridges can effectively reduce road-kills of small and medium-sized terrestrial vertebrates, even without guiding fences. Dry paths seemed to especially benefit amphibians which are a threatened species group worldwide and known to suffer high traffic mortality. PMID:24921961

Niemi, Milla; Jääskeläinen, Niina C; Nummi, Petri; Mäkelä, Tiina; Norrdahl, Kai

2014-11-01

260

Consumer-Directed Health Plans: Small but Growing Enrollment Fueled by Rising Cost of Health Care Coverage.  

National Technical Information Service (NTIS)

Insurance carriers, employers, and individuals are showing increasing interest in consumer-directed health plans (CDHP). CDHPs typically combine a high-deductible health plan with a health reimbursement arrangement (HRA) or health savings account (HSA). H...

2006-01-01

261

Location and direction dependent effects in collider physics from noncommutativity  

SciTech Connect

We examine the leading order noncommutative corrections to the differential and total cross sections for e{sup +}e{sup -{yields}}qq. After averaging over the Earth's rotation, the results depend on the latitude for the collider, as well as the direction of the incoming beam. They also depend on the scale and direction of the noncommutativity. Using data from LEP, we exclude regions in the parameter space spanned by the noncommutative scale and angle relative to the Earth's axis. We also investigate possible implications for phenomenology at the future International Linear Collider.

Haghighat, Mansour [Department of Physics, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Okada, Nobuchika; Stern, Allen [Department of Physics, University of Alabama, Tuscaloosa, Alabama 35487 (United States)

2010-07-01

262

Predicting and Evaluating the Effectiveness of Ocean Carbon Sequestration by Direct Injection  

Microsoft Academic Search

Direct injection of CO into the ocean is a potentially effective carbon sequestration strategy. Therefore, we want to understand the effectiveness of oceanic injection and develop the appropriate analytic framework to allow us to compare the effectiveness of this strategy with other carbon management options. Here, after a brief review of direct oceanic injection, we estimate the effectiveness of ocean

Ken Caldeira; Howard J. Herzog; Michael E. Wickett

2001-01-01

263

Effective small RNA destruction by the expression of a short tandem target mimic in Arabidopsis.  

PubMed

MicroRNAs (miRNAs) and other endogenous small RNAs act as sequence-specific regulators of the genome, transcriptome, and proteome in eukaryotes. The interrogation of small RNA functions requires an effective, widely applicable method to specifically block small RNA function. Here, we report the development of a highly effective technology that targets specific endogenous miRNAs or small interfering RNAs for destruction in Arabidopsis thaliana. We show that the expression of a short tandem target mimic (STTM), which is composed of two short sequences mimicking small RNA target sites, separated by a linker of an empirically determined optimal size, leads to the degradation of targeted small RNAs by small RNA degrading nucleases. The efficacy of the technology was demonstrated by the strong and specific developmental defects triggered by STTMs targeting three miRNAs and an endogenous siRNA. In summary, we developed an effective approach for the destruction of endogenous small RNAs, thereby providing a powerful tool for functional genomics of small RNA molecules in plants and potentially animals. PMID:22345490

Yan, Jun; Gu, Yiyou; Jia, Xiaoyun; Kang, Wenjun; Pan, Shangjin; Tang, Xiaoqing; Chen, Xuemei; Tang, Guiliang

2012-02-01

264

The Contrasting Effects of Wildfire and Clearfelling on the Hydrology of a Small Catchment  

NASA Astrophysics Data System (ADS)

A wildfire in an afforested research catchment presented the rare opportunity to compare the hydrological effects of wildfire with the effects of clearfelling in the same catchment in the Jonkershoek Valley, in the south-western Western Cape Province of South Africa. The timber plantation, which occupies 57% of the 2 km2 catchment, had been clearfelled and re-planted to Pinus radiata roughly five years before the fire. The effects of the two treatments on total flow, storm-flow and quick-flow volumes, peak discharge and storm response ratio were determined by means of multiple regression analysis, employing the dummy variable method to test for the significance of treatments. Both clearfelling and wildfire caused significant increases in all the stream-flow variables analysed. But the clearfelling effect was dominated by large increases in total flow (96% over three years), of which storm-flow and quick-flow volumes formed only minor parts. After the wildfire, by contrast, increases in total flow were small (12%) but the storm flow increases were three- to four-fold in the first year and roughly double in the second year. The wildfire caused fire-induced water repellency in the soils which led to overland flow on mid-slope sites, where soil infiltrability normally far exceeds local rainfall intensities. It is argued that these results support the hypothesis that stream-flow generation processes were changed by the wildfire in that overland flow made a direct contribution to storm flows, but that clearfelling had no such effect.

Scott, David F.

1997-05-01

265

Effect of small cage guests on hydrogen bonding of tetrahydrofuran in binary structure II clathrate hydrates  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations of the pure structure II tetrahydrofuran clathrate hydrate and binary structure II tetrahydrofuran clathrate hydrate with CO2, CH4, H2S, and Xe small cage guests are performed to study the effect of the shape, size, and intermolecular forces of the small cages guests on the structure and dynamics of the hydrate. The simulations show that the number and nature of the guest in the small cage affects the probability of hydrogen bonding of the tetrahydrofuran guest with the large cage water molecules. The effect on hydrogen bonding of tetrahydrofuran occurs despite the fact that the guests in the small cage do not themselves form hydrogen bonds with water. These results indicate that nearest neighbour guest-guest interactions (mediated through the water lattice framework) can affect the clathrate structure and stability. The implications of these subtle small guest effects on clathrate hydrate stability are discussed.

Alavi, Saman; Ripmeester, John A.

2012-08-01

266

Effect of cycle mean strain on small crack growth in Alloy 718 at elevated temperatures  

NASA Astrophysics Data System (ADS)

The influence of the cyclic compressive excursion on the fatigue crack growth behavior of small surface cracks in Alloy 718 at 650 C is studied experimentally. Test conditions were chosen to simulate the cyclic plasticity found at notch locations in high temperature structural components. During cycling, the crack lengths were continuously monitored using the direct current potential drop method while the near-field crack-mouth-opening displacement and global cyclic stress-strain behavior were measured using a laser interferometry technique and mechanical extensometry, respectively. Two aspects related to cyclic compressive excursion have been studied: crack closure and crack tip plasticity. Attempts have been made to use several modified Delta-K expressions as well as Delta-J(eff) to account for the effects of closure and decrease crack tip plasticity. It was concluded that the compressive excursion is most prominent in this alloy in its effect on the global plasticity and the sugbsequent loss of constraint. Closure was not found to be significant in the consolidation of test data.

Rosenberger, A. H.; Ghonem, H.

1992-11-01

267

Direct and indirect effects in microcosm communities of protists  

Microsoft Academic Search

Increased complexity in biological communities can increase the variety of interactions among species, but the relative strengths and long-term consequences of various direct and indirect interactions require further investigation. I studied interactions among four species of protists by monitoring their population dynamics when they were cultured either together or in seven different subset communities. Two protists were bacterivores (Chilomonas and

Sharon P. Lawler

1993-01-01

268

Goal Direction and Effectiveness, Emotional Maturity, and Nuclear Family Functioning  

ERIC Educational Resources Information Center

Differentiation of self, a cornerstone concept in Bowen theory, has a profound influence over time on the functioning of the individual and his or her family unit. This 5-year longitudinal study tested this hypothesis with 50 developing nuclear families. The dimensions of differentiation of self that were examined were goal direction and…

Klever, Phillip

2009-01-01

269

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment  

Microsoft Academic Search

AIM To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS Forty-two adult male Sprague- Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days. From the 4 th postoperational day, animals were randomly assigned

Xin Zhou; Yuan Xin Li; Ning Li; Jie Shou Li

270

Assessing the Effects of Small School Size on Mathematics Achievement: A Propensity Score-Matching Approach  

ERIC Educational Resources Information Center

Background: Small schools have been promoted as an educational reform that is capable of improving student outcomes. However, a survey of the research on small schools indicates that much of the movement for decreasing school size is based primarily on correlational methods that do not control for selection effects in the data. In addition,…

Wyse, Adam E.; Keesler, Venessa; Schneider, Barbara

2008-01-01

271

Interpretation of small effect sizes in occupational and environmental neurotoxicology: Individual versus population risk  

Microsoft Academic Search

Some have questioned the importance of the small effect sizes generally reported in epidemiological studies of neurotoxicity. To some extent, this reflects a failure to appreciate the critical distinction between individual and population risk. In the first part of the paper, arguments are marshaled to support the contention that small shifts in the mean value of a health index within

David C. Bellinger

2007-01-01

272

The Effect of Small Group Discussion on Cutoff Scores during Standard Setting  

ERIC Educational Resources Information Center

Standard setting methods, like the Bookmark procedure, are used to assist education experts in formulating performance standards. Small group discussion is meant to help these experts in setting more reliable and valid cutoff scores. This study is an analysis of 15 small group discussions during two standards setting trajectories and their effect

Deunk, Marjolein I.; van Kuijk, Mechteld F.; Bosker, Roel J.

2014-01-01

273

Interorganizational and Collective Strategies in Small Firms: Environmental Effects and Performance  

Microsoft Academic Search

This study provides evidence that collective strategy is prevalent in small firms in fragmented industries. COMPUSTAT data were combined with afield survey of small manufacturingfirms to test hypotheses concerning the relative frequencies of various collective strategies, the effects of environmental variables on collective activity, and the contribution of collective behavior to firm performance. Results indicate that agglomerate and organic collective

Marc J. Dollinger; Peggy A. Golden

1992-01-01

274

Nerve Regeneration in Vitro: Comparative Effects of Direct and Induced Current and NGF. Appendix.  

National Technical Information Service (NTIS)

Partial Contents: Nerve Regeneration In Vitro: Comparative Effects of Direct and Induced Current and NGF; Triethanolamine, Tris, Hepes, and Cytosine Arabinoside Show Neuritogenic Activity in Cultured Chick Embryo Ganglia; PEMF, Direct Current and Neuronal...

B. F. Sisken G. Ringham S. Dyer

1985-01-01

275

Experiment assessment of mass effects in the rat: implications for small animal PET imaging.  

PubMed

In vivo imaging using positron emission tomography (PET) is important in the development of new radiopharmaceuticals in rodent animal models for use as biochemical probes, diagnostic agents, or in drug development. We have shown mathematically that, if small animal imaging studies in rodents are to have the same "quality" as human PET studies, the same number of coincidence events must be detected from a typical rodent imaging "voxel" as from the human imaging voxel. To achieve this using the same specific activity preparation, we show that roughly the same total amount of radiopharmaceutical must be given to a rodent as to a human subject. At high specific activities, the mass associated with human doses, when administered to a rodent, may not decrease the uptake of radioactivity at non saturable sites or sites where an enzyme has a high capacity for a substrate. However, in the case of binding sites of low density such as receptors, the increased mass injected could saturate the receptor and lead to physiologic effects and non-linear kinetics. Because of the importance of the mass injected for small animal PET imaging, we experimentally compared high and low mass preparations using ex vivo biodistribution and phosphorimaging of three compounds: 2-fluoro-2-deoxyglucose (FDG), 6-fluoro-L-metatyrosine (FMT) and one receptor-directed compound, the serotonin 5HT1A receptor ligand, trans-4-fluoro-N-[2-[4-(2-methoxylphenyl) piperazino]ethyl]-N-(2-pyridyl) cyclohexane- carboxamide (FCWAY). Changes in the mass injected per rat did not affect the distribution of FDG, FMT, and FCWAY in the range of 0.6-1.9 nmol per rat. Changes in the target to nontarget ratio were observed for injected masses of FCWAY in the range of approximately 5-50 nmol per rat. If the specific activity of such compounds and/or the sensitivity of small animal scanners are not increased relative to human studies, small animal PET imaging will not correctly portray the "true" tracer distribution. These difficulties will only be exacerbated in animals smaller than the rat, e.g., mice. PMID:15246368

Jagoda, E M; Vaquero, J J; Seidel, J; Green, M V; Eckelman, W C

2004-08-01

276

The Effect of Extra Small Group Session during PBL Implementation on Student's Achievement  

ERIC Educational Resources Information Center

Problem based learning (PBL) started to spread in health professions in Saudi Arabia at the beginning of this century. There are several challenges facing its implementation such as defects on interpersonal communications and self-directed learning. These challenges would affect students' performance in small group discussions and their…

Khalil, Mahmoud Salah; Al Rukban, Mohammad Othman

2010-01-01

277

InGaAsP/InP MQW directional coupler switch with small and low-loss bends for fiber-array coupling  

NASA Astrophysics Data System (ADS)

We report on a compact InGaAsP/InP MQW directional coupler switch with spacing between the waveguides at the input and the output facets larger than 125 micron, required for the fiber-array coupling, by employing small and low-loss bends. The total device length, including both the coupling and the bending regions, with the different optical confinements in the lateral direction is 2 mm. The coupling region of the switch is 420 micron, and the voltage-length product at switching is around 6 Vmm.

Aizawa, T.; Ravikumar, K. G.; Nagasawa, Y.; Sekiguchi, T.; Watanabe, T.

1994-06-01

278

Direct effects of habitat area on interaction diversity in pollination webs.  

PubMed

Island biogeography theory predicts that species richness increases with habitat area and declines with isolation. We expand this framework to address changes in the number of links and species in pollination webs from 12 isolated hills, ranging in area from tens to thousands of hectares, immersed in the agriculture matrix of the Argentine Pampas. We also studied whether total interaction frequency is partitioned more evenly among individual links in richer webs. Our results reveal a direct effect of area on the number of links and species present in each pollination web. However, link richness increased twofold faster than species richness with area. These area effects were not confounded by sampling effort or correlated incidence of exotic species, despite widespread habitat disturbance. Habitat proximity, an inverse measure of isolation, had a marginally significant influence on link but not on species richness. Increased link number was associated with decreasing dominance by any particular interaction and increasing interaction evenness. Despite the strong area effect, a rich pollination web sampled from a small, protected sierra suggests that simple conservation measures, such as reduced grazing and fire suppression, may effectively preserve much local interaction diversity. PMID:20945753

Sabatino, Malena; Maceira, Néstor; Aizen, Marcelo A

2010-09-01

279

CYTOPROTECTIVE EFFECTS OF IAPS REVEALED BY A SMALL MOLECULE ANTAGONIST  

PubMed Central

SYNOPSIS Deregulated expression of members of the Inhibitor of Apoptosis (IAP) family has been found in a wide variety of neoplastic cells, and synthetic IAP antagonists represent a promising novel class of chemotherapeutic agents. Early work focused on the ability of these compounds to block the caspase inhibitory function of XIAP. However, recent studies have shown that IAP antagonists, although primarily designed to target XIAP, trigger a ubiquitin-mediated degradation of two related proteins, c-IAP1 and c-IAP2, and through this process potentiate the death of tumor cells via autocrine cellular signaling pathways. In this context, the relative contribution of XIAP as a target of this class of compounds is unclear. Here we examine the involvement of XIAP using a recently described synthetic IAP antagonist, AEG40730, and through the comparison of a human tumor cell line targeted for XIAP with its isogenic, wild type control line. Treatment with nanomolar concentrations of AEG40730 resulted in the loss of both XIAP and c-IAP1 proteins, albeit with different kinetics. While XIAP-deficient HCT116 cells retained some sensitivity to AEG40730 to external apoptotic stimuli, the data suggest that IAP antagonists such as AEG40730 exert their apoptotic enhancing effects through XIAP in addition to the c-IAPs. These data indicate that IAP antagonists can target multiple IAPs to augment distinct pro-apoptotic signaling pathways, thereby revealing the potential for these compounds in cancer therapy and underscoring the promise of IAP-targeted therapies.

Galban, Stefanie; Hwang, Clara; Rumble, Julie M.; Oetjen, Karolyn A.; Wright, Casey W.; Boudreault, Alain; Durkin, Jon; Gillard, John W.; Jaquith, James B.; Morris, Stephen J.; Duckett, Colin S.

2009-01-01

280

Small Effective Population Sizes and Rare Nonsynonymous Variants in Potyviruses  

PubMed Central

Analysis of nucleotide sequence polymorphism in complete genomes of 12 species of potyviruses (single-stranded, positive-sense RNA viruses, family Potyviridae) revealed evidence that long-term effective population sizes of these viruses are on the order of 104. Comparison of nucleotide diversity in non-coding regions and at synonymous and nonsynonymous sites in coding regions showed that purifying selection has acted to eliminate numerous deleterious mutations both at nonsynonymous sites and in non-coding regions. The ratio of nonsynonymous to synonymous polymorphic sites increased as a function of the number of genomes sampled, whereas mean gene diversity at nonsynonymous polymorphic sites decreased with increasing sample size at a substantially faster rate than does mean gene diversity at synonymous polymorphic sites. Very similar relationships were observed both in available genomic sequences of 12 potyvirus species and in subsets created by randomly sampling from among 98 TuMV genomes. Taken together, these observations imply that a greater proportion of nonsynonymous than of synonymous variants are relatively rare as the result of ongoing purifying selection, and thus many nonsynonymous variants are unlikely to be discovered without extensive sampling.

Hughes, Austin L.

2009-01-01

281

Experimental studies of the direct flexoelectric effect in bone materials  

Microsoft Academic Search

The piezoelectric effect in biological tissues has been attracting research interest due to the hypothesis that it may behave as a biological transducer, which can convert external stimuli into biologically-recognizable signals capable of controlling growth or resorptive processes. The piezoelectric effect in dried bone materials was first observed in 1957 [1]. A link between the effect and the adaptive response

John Fu

2010-01-01

282

miRNA-200c inhibits invasion and metastasis of human non-small cell lung cancer by directly targeting ubiquitin specific peptidase 25  

PubMed Central

Background Growing evidence indicates that miR-200c is involved in carcinogenesis and tumor progression in non-small-cell lung cancer (NSCLC). However, its precise biological role remains largely elusive. Methods The functions of miR-200c and USP25 in migration/invasion and lung metastasis formation were determined by transwell and tail vein injection assays, respectively. The potential regulatory targets of miR-200c were determined by prediction tools, correlation with target protein expression, and luciferase reporter assay. The mRNA expression levels of miR-200c and USP25 were examined in NSCLC cell lines and patient specimens using quantitative reverse transcription-PCR. The protein expression levels of USP25 were examined in NSCLC cell lines and patient specimens using western blot and immunohistochemical staining. Results We demonstrated that over-expression of miR-200c inhibited NSCLC cells migration, invasion, epithelial-mesenchymal transition (EMT) in vitro and lung metastasis formation in vivo. Further studies revealed that USP25 was a downstream target of miR-200c in NSCLC cells as miR-200c bound directly to the 3’-untranslated region of USP25, thus reducing both the messenger RNA and protein levels of USP25. Silencing of the USP25 gene recapitulated the effects of miR-200c over-expression. Clinical analysis indicated that miR-200c was negatively correlated with clinical stage, lymph node metastasis in NSCLC patients. Moreover, USP25 protein and mRNA level expressions were higher in NSCLC patients, compared to healthy control, and correlated with clinical stage and lymphatic node metastasis. Conclusions These findings indicate that miR-200c exerts tumor-suppressive effects for NSCLC through the suppression of USP25 expression and suggests a new therapeutic application of miR-200c in the treatment of NSCLC.

2014-01-01

283

Collective effects in traffic on bi-directional ant trails.  

PubMed

Motivated by recent experimental work of Burd et al., we propose a model of bi-directional ant traffic on pre-existing ant trails. It captures in a simple way some of the generic collective features of movements of real ants on a trail. Analysing this model, we demonstrate that there are crucial qualitative differences between vehicular- and ant-traffics. In particular, we predict some unusual features of the flow rate that can be tested experimentally. As in the uni-directional model a non-monotonic density-dependence of the average velocity can be observed in certain parameter regimes. As a consequence of the interaction between oppositely moving ants the flow rate can become approximately constant over some density interval. PMID:15380392

John, Alexander; Schadschneider, Andreas; Chowdhury, Debashish; Nishinari, Katsuhiro

2004-11-21

284

Effects of air flow directions on composting process temperature profile  

SciTech Connect

In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

Kulcu, Recep [Akdeniz University, Faculty of Agriculture, Department of Farm Machinery, Antalya (Turkey); Yaldiz, Osman [Akdeniz University, Faculty of Agriculture, Department of Farm Machinery, Antalya (Turkey)], E-mail: yaldiz@akdeniz.edu.tr

2008-07-01

285

Effects of air flow directions on composting process temperature profile.  

PubMed

In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO(2) and O(2) ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2. PMID:17888646

Kulcu, Recep; Yaldiz, Osman

2008-01-01

286

Repetition effects in directed forgetting: evidence for retrieval inhibition  

Microsoft Academic Search

Four experiments were conducted in support of a role for memory retrieval inhibition in directed forgetting. In each experiment,\\u000a subjects were presented a list of words, some of which they were instructed to remember and some of which they were instructed\\u000a to forget. After a recall test for all the words, the list was repeated. This time, however, all the

R. Edward Geiselman; Behrooz Bagheri

1985-01-01

287

Direct measurement of Lorentz transformation with Doppler effects  

Microsoft Academic Search

For space science and astronomy the fundamentality of one-way velocity of light (OWVL) is selfevident. The measurement of OWVL (distance\\/interval) and the clock synchronization with light-signal transfer make a logical circulation. This means that OWVL could not be directly measured but only come indirectly from astronomical method (Romer's Io eclipse and Bradley's sidereal aberration), furthermore, the light-year by definitional OWVL

Shao-Guang Chen

2008-01-01

288

Cellular effects of acute direct current stimulation: somatic and synaptic terminal effects  

PubMed Central

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique to modulate cortical excitability. Although increased/decreased excitability under the anode/cathode electrode is nominally associated with membrane depolarization/hyperpolarization, which cellular compartments (somas, dendrites, axons and their terminals) mediate changes in cortical excitability remains unaddressed. Here we consider the acute effects of DCS on excitatory synaptic efficacy. Using multi-scale computational models and rat cortical brain slices, we show the following. (1) Typical tDCS montages produce predominantly tangential (relative to the cortical surface) direction currents (4–12 times radial direction currents), even directly under electrodes. (2) Radial current flow (parallel to the somatodendritic axis) modulates synaptic efficacy consistent with somatic polarization, with depolarization facilitating synaptic efficacy. (3) Tangential current flow (perpendicular to the somatodendritic axis) modulates synaptic efficacy acutely (during stimulation) in an afferent pathway-specific manner that is consistent with terminal polarization, with hyperpolarization facilitating synaptic efficacy. (4) Maximal polarization during uniform DCS is expected at distal (the branch length is more than three times the membrane length constant) synaptic terminals, independent of and two–three times more susceptible than pyramidal neuron somas. We conclude that during acute DCS the cellular targets responsible for modulation of synaptic efficacy are concurrently somata and axon terminals, with the direction of cortical current flow determining the relative influence.

Rahman, Asif; Reato, Davide; Arlotti, Mattia; Gasca, Fernando; Datta, Abhishek; Parra, Lucas C; Bikson, Marom

2013-01-01

289

Cellular effects of acute direct current stimulation: somatic and synaptic terminal effects.  

PubMed

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique to modulate cortical excitability. Although increased/decreased excitability under the anode/cathode electrode is nominally associated with membrane depolarization/hyperpolarization, which cellular compartments (somas, dendrites, axons and their terminals) mediate changes in cortical excitability remains unaddressed. Here we consider the acute effects of DCS on excitatory synaptic efficacy. Using multi-scale computational models and rat cortical brain slices, we show the following. (1) Typical tDCS montages produce predominantly tangential (relative to the cortical surface) direction currents (4-12 times radial direction currents), even directly under electrodes. (2) Radial current flow (parallel to the somatodendritic axis) modulates synaptic efficacy consistent with somatic polarization, with depolarization facilitating synaptic efficacy. (3) Tangential current flow (perpendicular to the somatodendritic axis) modulates synaptic efficacy acutely (during stimulation) in an afferent pathway-specific manner that is consistent with terminal polarization, with hyperpolarization facilitating synaptic efficacy. (4) Maximal polarization during uniform DCS is expected at distal (the branch length is more than three times the membrane length constant) synaptic terminals, independent of and two-three times more susceptible than pyramidal neuron somas. We conclude that during acute DCS the cellular targets responsible for modulation of synaptic efficacy are concurrently somata and axon terminals, with the direction of cortical current flow determining the relative influence. PMID:23478132

Rahman, Asif; Reato, Davide; Arlotti, Mattia; Gasca, Fernando; Datta, Abhishek; Parra, Lucas C; Bikson, Marom

2013-05-15

290

Analysis of small scale turbulent structures and the effect of spatial scales on gas transfer  

NASA Astrophysics Data System (ADS)

The exchange of gases through the air-sea interface strongly depends on environmental conditions such as wind stress and waves which in turn generate near surface turbulence. Near surface turbulence is a main driver of surface divergence which has been shown to cause highly variable transfer rates on relatively small spatial scales. Due to the cool skin of the ocean, heat can be used as a tracer to detect areas of surface convergence and thus gather information about size and intensity of a turbulent process. We use infrared imagery to visualize near surface aqueous turbulence and determine the impact of turbulent scales on exchange rates. Through the high temporal and spatial resolution of these types of measurements spatial scales as well as surface dynamics can be captured. The surface heat pattern is formed by distinct structures on two scales - small-scale short lived structures termed fish scales and larger scale cold streaks that are consistent with the footprints of Langmuir Circulations. There are two key characteristics of the observed surface heat patterns: 1. The surface heat patterns show characteristic features of scales. 2. The structure of these patterns change with increasing wind stress and surface conditions. In [2] turbulent cell sizes have been shown to systematically decrease with increasing wind speed until a saturation at u* = 0.7 cm/s is reached. Results suggest a saturation in the tangential stress. Similar behaviour has been observed by [1] for gas transfer measurements at higher wind speeds. In this contribution a new model to estimate the heat flux is applied which is based on the measured turbulent cell size und surface velocities. This approach allows the direct comparison of the net effect on heat flux of eddies of different sizes and a comparison to gas transfer measurements. Linking transport models with thermographic measurements, transfer velocities can be computed. In this contribution, we will quantify the effect of small scale processes on interfacial transport and relate it to gas transfer. References [1] T. G. Bell, W. De Bruyn, S. D. Miller, B. Ward, K. Christensen, and E. S. Saltzman. Air-sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed. Atmos. Chem. Phys. , 13:11073-11087, 2013. [2] J Schnieders, C. S. Garbe, W.L. Peirson, and C. J. Zappa. Analyzing the footprints of near surface aqueous turbulence - an image processing based approach. Journal of Geophysical Research-Oceans, 2013.

Schnieders, Jana; Garbe, Christoph

2014-05-01

291

Small Molecule Structure Correctors Abolish Detrimental Effects of Apolipoprotein E4 in Cultured Neurons*  

PubMed Central

Apolipoprotein E4 (apoE4), the major genetic risk factor for late onset Alzheimer disease, assumes a pathological conformation, intramolecular domain interaction. ApoE4 domain interaction mediates the detrimental effects of apoE4, including decreased mitochondrial cytochrome c oxidase subunit 1 levels, reduced mitochondrial motility, and reduced neurite outgrowth in vitro. Mutant apoE4 (apoE4-R61T) lacks domain interaction, behaves like apoE3, and does not cause detrimental effects. To identify small molecules that inhibit domain interaction (i.e. structure correctors) and reverse the apoE4 detrimental effects, we established a high throughput cell-based FRET primary assay that determines apoE4 domain interaction and secondary cell- and function-based assays. Screening a ChemBridge library with the FRET assay identified CB9032258 (a phthalazinone derivative), which inhibits domain interaction in neuronal cells. In secondary functional assays, CB9032258 restored mitochondrial cytochrome c oxidase subunit 1 levels and rescued impairments of mitochondrial motility and neurite outgrowth in apoE4-expressing neuronal cells. These benefits were apoE4-specific and dose-dependent. Modifying CB9032258 yielded well defined structure-activity relationships and more active compounds with enhanced potencies in the FRET assay (IC50 of 23 and 116 nm, respectively). These compounds efficiently restored functional activities of apoE4-expressing cells in secondary assays. An EPR binding assay showed that the apoE4 structure correction resulted from direct interaction of a phthalazinone. With these data, a six-feature pharmacophore model was constructed for future drug design. Our results serve as a proof of concept that pharmacological intervention with apoE4 structure correctors negates apoE4 detrimental effects in neuronal cells and could be further developed as an Alzheimer disease therapeutic.

Chen, Hung-Kai; Liu, Zhaoping; Meyer-Franke, Anke; Brodbeck, Jens; Miranda, Rene D.; McGuire, James G.; Pleiss, Michael A.; Ji, Zhong-Sheng; Balestra, Maureen E.; Walker, David W.; Xu, Qin; Jeong, Dah-eun; Budamagunta, Madhu S.; Voss, John C.; Freedman, Stephen B.; Weisgraber, Karl H.; Huang, Yadong; Mahley, Robert W.

2012-01-01

292

Tumor-stromal interactions with direct cell contacts enhance motility of non-small cell lung cancer cells through the hedgehog signaling pathway.  

PubMed

The metastatic potential of non-small cell lung cancer (NSCLC) has been shown to be associated with interactions with the tumor microenvironment, which primarily comprises of cancer-associated fibroblasts (CAFs). Heterotypic cell-cell interactions occur via released signaling molecules and direct physical contact. To investigate the differential contribution of direct cell-cell contact and paracrine signaling factors to NSCLC metastasis, we performed two types of co-cultures: direct co-cultures of the NSCLC cell line H358 with primary cultures of CAFs from patients with resected NSCLC; and indirect co-cultures across a separable membrane. We showed that CAFs more potently induce epithelial-to-mesenchymal transition (EMT) in NSCLC H358 cells through direct contacts than through indirect interactions, as indicated by an elongated and disseminated appearance. Immunocytochemical experiments show that EMT accompanies the expression of mesenchymal cytoskeletal proteins, including vimentin. However, H358 cells proliferate more slowly in direct co-culture than in indirect co-culture. Real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed that H358 cells in direct contact with CAFs up-regulate the expression of the pan-mesenchymal markers ?-smooth muscle actin (?-SMA), fibroblast activation protein (FAP), transforming growth factor-? (TGF?) signaling effector SMAD family number-3 (SMAD3), and hedgehog signaling effector GLI family zinc finger-1 (GLI1), compared with the indirect co-culture system. Furthermore, we found that the direct GLI1 transcription targets snail family zinc finger-1 (SNAI1) and SNAI2 are up-regulated, suggesting that the hedgehog signaling pathway is active in direct co-culture. A scratch wound assay showed that direct contact co-culture increases the motility of H358 cells. In conclusion, these findings provide evidence that paracrine factors and direct physical contact between NSCLC cells and CAFs might control the metastatic potential of NSCLC through the hedgehog signaling pathway. PMID:24023301

Choe, Chungyoul; Shin, Yong-Sung; Kim, Sung-Hyun; Jeon, Mi-Jin; Choi, So-Jung; Lee, Jinseon; Kim, Jhingook

2013-09-01

293

A simulation study of the effects of small center enrollment in multi-center clinical trials  

Microsoft Academic Search

Multi-center clinical trials are very common in the development of new drugs and devices. One concern in such trials, is the effect of individual investigational sites enrolling small numbers of patients on the overall result. Can the presence of small centers cause an ineffective treatment to appear effective when treatment-by-center interaction is not statistically significant?^ In this research, simulations are

Jaye Lynne Thompson

1996-01-01

294

Mechanisms underpinning climatic impacts on natural populations: altered species interactions are more important than direct effects.  

PubMed

Shifts in species' distribution and abundance in response to climate change have been well documented, but the underpinning processes are still poorly understood. We present the results of a systematic literature review and meta-analysis investigating the frequency and importance of different mechanisms by which climate has impacted natural populations. Most studies were from temperate latitudes of North America and Europe; almost half investigated bird populations. We found significantly greater support for indirect, biotic mechanisms than direct, abiotic mechanisms as mediators of the impact of climate on populations. In addition, biotic effects tended to have greater support than abiotic factors in studies of species from higher trophic levels. For primary consumers, the impact of climate was equally mediated by biotic and abiotic mechanisms, whereas for higher level consumers the mechanisms were most frequently biotic, such as predation or food availability. Biotic mechanisms were more frequently supported in studies that reported a directional trend in climate than in studies with no such climatic change, although sample sizes for this comparison were small. We call for more mechanistic studies of climate change impacts on populations, particularly in tropical systems. PMID:24677405

Ockendon, Nancy; Baker, David J; Carr, Jamie A; White, Elizabeth C; Almond, Rosamunde E A; Amano, Tatsuya; Bertram, Esther; Bradbury, Richard B; Bradley, Cassie; Butchart, Stuart H M; Doswald, Nathalie; Foden, Wendy; Gill, David J C; Green, Rhys E; Sutherland, William J; Tanner, Edmund V J; Pearce-Higgins, James W

2014-07-01

295

Direct MRI detection of the neuronal magnetic field: the effect of the dendrite branch  

NASA Astrophysics Data System (ADS)

In recent years, neuronal current MRI (nc-MRI) was proposed as a new imaging method to directly map the magnetic field change caused by neuronal activity. Nc-MRI could offer improved spatial and temporal resolution compared to blood hemodynamics-based functional magnetic resonance imaging (fMRI). In this paper, with a finite current dipole as the model of dendrite or dendrite branch, we investigated the spatial distribution of the magnetic field generated by synchronously activated neurons to evaluate the possibility of nc-MRI. Our simulations imply that the existence of a dendrite branch may not only increase the strength of the neuronal magnetic field (NMF), but also raise the non-uniform and unsymmetry of the NMF; therefore, it can enhance the detectability of the neuronal current magnetic field by MRI directly. The results show that the signal phase shift is enlarged, but it is unstable and is still very small, Lt1 radian, while the magnitude signal may be strong enough for a typical MRI voxel to be detected. We suggest making further efforts to measure the magnitude signal which may induce a large effect in an nc-MRI experiment.

Huang, Ying-ling; Xiong, Hong-chuan; Yao, De-zhong

2010-09-01

296

Investigation of the direct effects of salmon calcitonin on human osteoarthritic chondrocytes  

Microsoft Academic Search

BACKGROUND: Calcitonin has been demonstrated to have chondroprotective effects under pre-clinical settings. It is debated whether this effect is mediated through subchondral-bone, directly on cartilage or both in combination. We investigated possible direct effects of salmon calcitonin on proteoglycans and collagen-type-II synthesis in osteoarthritic (OA) cartilage. METHODS: Human OA cartilage explants were cultured with salmon calcitonin [100 pM-100 nM]. Direct

Bodil-Cecilie Sondergaard; Suzi H Madsen; Toni Segovia-Silvestre; Sarah J Paulsen; Thorbjorn Christiansen; Christian Pedersen; Anne-Christine Bay-Jensen; Morten A Karsdal

2010-01-01

297

Porosity effects on machining direction -- Strength anisotropy and failure mechanisms  

Microsoft Academic Search

The anisotropy in room-temperature flexural strength of ceramics as a result of machining test bar tensile surfaces parallel vs perpendicular to the bar axis was studied for various porous bodies. This shows that fine, relatively homogeneous porosity has no significant effect on such strength anisotropy, implying that such porosity has no significant effect on flaw sizes or shapes, which was

Roy W. Rice

1994-01-01

298

Effective PSHE Education: Values, Purposes and Future Directions  

ERIC Educational Resources Information Center

This article explores the perceived effectiveness of personal, social, health and economic (PSHE) education in primary and secondary schools. It outlines the relationship between perceived effectiveness and a range of explanatory factors, linking these to the values and ethos of schools, differing views of the purposes of PSHE education, and…

Willis, Ben; Clague, Lucy; Coldwell, Mike

2013-01-01

299

Small business policy in the United Kingdom: the inheritance of the Small Business Service and implications for its future effectiveness  

Microsoft Academic Search

The launch of the Small Business Service in the United Kingdom stimulated a review of small business policy and support in the United Kingdom. The Service inherited a substantial number of policies and initiatives which have been criticised for their poorly stated aims and overall lack of coherence. The authors examine justifications for small business policy in Britain and the

James Curran; David J Storey

2002-01-01

300

Effect of wood creosote and loperamide on propulsive motility of mouse colon and small intestine.  

PubMed

To elucidate a mechanism of the antidiarrheal activity of wood creosote, its effect on the propulsive motility of mouse colon and small intestine was studied using a charcoal meal test and a colonic bead expulsion test. The effect was compared with that of loperamide. At an ordinary therapeutic dose, wood creosote inhibited the propulsive motility of colon, but not of small intestine. On the other hand, loperamide inhibited the propulsive motility of small intestine, but not of colon. The results indicate that at least a part of the antidiarrheal activity of wood creosote and loperamide is attributable to their antikinetic effect predominantly on colon of the former and predominantly on small intestine of the latter. PMID:10474081

Ogata, N; Ataka, K; Morino, H; Shibata, T

1999-10-01

301

Effect of Small Frequency Changes on the Radiation Patterns of MF (AM) Directional Antennas.  

National Technical Information Service (NTIS)

The pressure to provide additional full time facilities in the AM (standard broadcasting) band in the United States resulted in a rulemaking petition filed with the Federal Communications Commission (FCC). The petition proposed the reduction of the AM cha...

A. C. Stewart J. B. Heffelfinger

1980-01-01

302

Thermal effects in rapid directional solidification - Linear theory  

NASA Technical Reports Server (NTRS)

We study the morphological instability of the planar solid/liquid interface for a unidirectionally-solidified dilute binary mixture. We use a model developed by Boettinger et al. (1985, 1986), Aziz (1982), and Jackson et al. (1980), which allows for nonequilibrium effects on the interface through velocity-dependent segregation and attachment kinetics. Two types of instabilities are found in the linear stability analysis: (1) a cellular instability, and (2) an oscillatory instability driven by disequilibrium effects. Merchant and Davis (1990) characterized these instabilities subject to the frozen-temperature approximation (FTA). The present work relaxes the FTA by including the effects of latent heat and the full temperature distribution. Thermal effects slightly postpone the onset of the cellular instability but dramatically postpone the onset of the oscillatory instability; however, the absolute-stability conditions, at which at high speed the cellular and oscillatory instabilities are suppressed, remain unchanged from the FTA.

Huntley, D. A.; Davis, S. H.

1993-01-01

303

DIGITAL AUDIO EFFECTS APPLIED DIRECTLY ON A DSD BITSTREAM  

Microsoft Academic Search

Digital audio effects are typically implemented on 16 or 24 bit signals sam- pled at 44.1 kHz. Yet high quality audio is often encoded in a one-bit, highly oversampled format , such as DSD. Processing of a bitstream, and the application of audio effects on a bitstream, requires special care and modification of existing methods. However, it has strong advantages

Josh Reiss; Mark Sandler

2004-01-01

304

Direct vascular effects of HMG-CoA reductase inhibitors  

Microsoft Academic Search

Several studies have demonstrated that any beneficial effect of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) on coronary events are linked to their hypocholesterolemic properties. However, since mevalonic acid (MVA), the product of the enzyme reaction, is the precursor of numerous metabolites, inhibition of HMG-CoA reductase has the potential to result in pleiotropic effects. MVA and other intermediates of cholesterol synthesis

Stefano Bellosta; Franco Bernini; Nicola Ferri; Pierangelo Quarato; Monica Canavesi; Lorenzo Arnaboldi; Remo Fumagalli; Rodolfo Paoletti; Alberto Corsini

1998-01-01

305

Palms, peccaries and perturbations: widespread effects of small-scale disturbance in tropical forests  

PubMed Central

Background Disturbance is an important process structuring ecosystems worldwide and has long been thought to be a significant driver of diversity and dynamics. In forests, most studies of disturbance have focused on large-scale disturbance such as hurricanes or tree-falls. However, smaller sub-canopy disturbances could also have significant impacts on community structure. One such sub-canopy disturbance in tropical forests is abscising leaves of large arborescent palm (Arececeae) trees. These leaves can weigh up to 15 kg and cause physical damage and mortality to juvenile plants. Previous studies examining this question suffered from the use of static data at small spatial scales. Here we use data from a large permanent forest plot combined with dynamic data on the survival and growth of > 66,000 individuals over a seven-year period to address whether falling palm fronds do impact neighboring seedling and sapling communities, or whether there is an interaction between the palms and peccaries rooting for fallen palm fruit in the same area as falling leaves. We tested the wider generalisation of these hypotheses by comparing seedling and sapling survival under fruiting and non-fruiting trees in another family, the Myristicaceae. Results We found a spatially-restricted but significant effect of large arborescent fruiting palms on the spatial structure, population dynamics and species diversity of neighbouring sapling and seedling communities. However, these effects were not found around slightly smaller non-fruiting palm trees, suggesting it is seed predators such as peccaries rather than falling leaves that impact on the communities around palm trees. Conversely, this hypothesis was not supported in data from other edible species, such as those in the family Myristicaceae. Conclusions Given the abundance of arborescent palm trees in Amazonian forests, it is reasonable to conclude that their presence does have a significant, if spatially-restricted, impact on juvenile plants, most likely on the survival and growth of seedlings and saplings damaged by foraging peccaries. Given the abundance of fruit produced by each palm, the widespread effects of these small-scale disturbances appear, over long time-scales, to cause directional changes in community structure at larger scales.

2012-01-01

306

The effect of directed forgetting on post traumatic stress disorder peddlers  

Microsoft Academic Search

Traumatic memory of post traumatic stress disorder peddlers can affect competition performance, and even avoid competition. The paper explored the effect of directed forgetting on post traumatic stress disorder peddlers. The results showed that:(1) directed forgetting affected explicit and implicit memory of post traumatic stress disorder peddlers whose remember items were better than forget items. The findings showed directed forgetting

Fenghai Cai

2010-01-01

307

Spatial bias: effects of early reading direction on Korean subjects.  

PubMed

Spatial bias may occur in subjects performing a number of cognitive and visual-motor tasks. These include coordinate visuospatial computations (e.g. bisecting a line) and categorical representations of syntactic information (e.g. drawing a picture depicting the action of a sentence). Readers of European languages scan from left-to-right and this learned visual scanning may contribute to leftward spatial bias. In 30 subjects who first learned to read in a top-to-bottom, right-to-left direction (right-left vertical readers, RL), we tested spatial-syntactic bias by reading sentences to subjects, who drew pictures depicting the actions. We noted whether the subject of the sentence was located leftward or rightward of the object. We assessed visual-spatial bias by measuring subjects' accuracy at bisecting lines, and by measuring how closely their drawings on the house-tree-person test were centered on the page. On the spatial-syntactic task, the RL were not right- or left-biased (P=0.581). Korean controls (left-right horizontal readers, LR) also showed no significant spatial-syntactic bias. RL only tended to bisect lines leftward, but displaced house-tree-person drawings left of page center (P<0.001). LR erred leftward on line bisection, and had a smaller magnitude leftward bias on drawing tasks. We conclude that a leftward spatial-syntactic bias may not be innate and does not appear to be influenced by learned reading direction. In contrast, the leftward visual-spatial bias may occur in subjects whose cultural and reading background is neither western nor left-to-right. PMID:11900752

Barrett, Anna M; Kim, Manho; Crucian, Gregory P; Heilman, Kenneth M

2002-01-01

308

Small satellites  

NASA Technical Reports Server (NTRS)

Satellites smaller than Mimas (r = 195 km) are distinguished by irregular overall shapes and by rough limb topography. Material properties and impact cratering dominate the shaping of these objects. Long fragmentation histories can produce a variety of internal structures, but so far there is no direct evidence that any small satellite is an equilibrium ellipsoid made up of noncohesive gravitationally bound rubble. One many bodies that orbit close to their primary the tidal and rotational components of surface gravity strongly affect the directions of local g and thereby affect the redistribution of regolith by mass wasting. Downslope movement of regolith is extensive on Deimos, and is probably effective on many other small satellites. It is shown that in some cases observed patterns of downslope mass wasting cold produce useful constraints on the satellite's mean density. The diversity of features seen in the few high-resolution images of small satellites currently available suggests that these objects have undergone complex histories of cratering, fragmentation, and regolith evolution.

Thomas, P.; Veverka, J.; Dermott, S.

1986-01-01

309

Direct estimation of the cost effectiveness of tornado shelters.  

PubMed

This article estimates the cost effectiveness of tornado shelters using the annual probability of a tornado and new data on fatalities per building struck by a tornado. This approach differs from recent estimates of the cost effectiveness of tornado shelters in Reference 1 that use historical casualties. Historical casualties combine both tornado risk and resident action. If residents of tornado-prone states take greater precautions, observed fatalities might not be much higher than in states with lower risk. Estimation using the tornado probability avoids this potential bias. Despite the very different method used, the estimates are 68 million US dollars in permanent homes and 6.0 million US dollars in mobile homes in Oklahoma using a 3% real discount rate, within about 10% of estimates based on historical fatalities. The findings suggest that shelters provide cost-effective protection for mobile homes in the most tornado-prone states but not for permanent homes. PMID:16948687

Simmons, Kevin M; Sutter, Daniel

2006-08-01

310

Neural lineage-specific homeoprotein BRN2 is directly involved in TTF1 expression in small-cell lung cancer.  

PubMed

Thyroid transcription factor 1 (TTF1) plays crucial roles in thyroid, lung, and developing brain morphogenesis. Because TTF1-expressing neoplasms are generated from organs and tissues that normally express TTF1, such as the thyroid follicular epithelium and peripheral lung airway epithelium, TTF1 is widely used as a cell lineage-specific and diagnostic marker for thyroid carcinomas and for lung adenocarcinomas with terminal respiratory unit (TRU) differentiation. However, among lung neuroendocrine tumors, small-cell carcinomas (small-cell lung cancers (SCLCs)), most of which are generated from the central airway, also frequently express TTF1 at high levels. To clarify how SCLCs express TTF1, we investigated the molecular mechanisms of its expression using cultivated lung cancer cells and focusing upon neural cell-specific transcription factors. Both SCLC cells and lung adenocarcinoma cells predominantly expressed isoform 2 of TTF1, and TTF1 promoter assays in SCLC cells revealed that the crucial region for activation of the promoter, which is adjacent to the transcription start site of TTF1 isoform 2, has potent FOX-, LHX-, and BRN2-binding sites. Transfection experiments using expression vectors for FOXA1, FOXA2, LHX2, LHX6, and BRN2 showed that BRN2 substantially upregulated TTF1 expression, whereas FOXA1/2 weakly upregulated TTF1 expression. BRN2 and FOXA1/2 binding to the TTF1 promoter was confirmed through chromatin immunoprecipitation experiments, and TTF1 expression in SCLC cells was considerably downregulated after BRN2 knockdown. Furthermore, the TTF1 promoter in SCLC cells was scarcely methylated, and immunohistochemical examinations using a series of primary lung tumors indicated that TTF1 and BRN2 were coexpressed only in SCLC cells. These findings suggest that TTF1 expression in SCLC is a cell lineage-specific phenomenon that involves the developing neural cell-specific homeoprotein BRN2. PMID:23358112

Sakaeda, Masashi; Sato, Hanako; Ishii, Jun; Miyata, Chie; Kamma, Hiroshi; Shishido-Hara, Yukiko; Shimoyamada, Hiroaki; Fujiwara, Masachika; Endo, Tetsuya; Tanaka, Ryota; Kondo, Haruhiko; Goya, Tomoyuki; Aoki, Ichiro; Yazawa, Takuya

2013-04-01

311

Direct and Collateral Effects of Restraints and Restraint Fading.  

ERIC Educational Resources Information Center

A study of three individuals with self-injurious behavior (SIB) evaluated a device designed for restraint fading with individuals who display hand-to-head SIB. Results demonstrated that stimulus control of SIB occurred in all individuals subsequent to restraint fading. The study also examined the effects of the rigid arm sleeves and restraint…

Fisher, Wayne W.; And Others

1997-01-01

312

Effective Peer Assessment Processes: Research Findings and Future Directions  

ERIC Educational Resources Information Center

Despite the popularity of peer assessment (PA), gaps in the literature make it difficult to describe exactly what constitutes effective PA. In a literature review, we divided PA into variables and then investigated their interrelatedness. We found that (a) PA's psychometric qualities are improved by the training and experience of peer assessors;…

van Zundert, Marjo; Sluijsmans, Dominique; van Merrienboer, Jeroen

2010-01-01

313

Continued research on direct contact heat exchangers: Effects of crystallization  

NASA Astrophysics Data System (ADS)

This report describes a preliminary study to determine whether crystallizer schemes could be effectively used in binary geothermal power plants. An industry and literature search was conducted for models that predict potential scale formation. The results indicated that the theoretical models for predicting not only homogeneous nucleation, but also secondary nucleation are suspect.

Jacobs, H. R.

1987-07-01

314

Acute Stressor Effects on Goal-Directed Action in Rats  

ERIC Educational Resources Information Center

Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on…

Braun, Stephanie; Hauber, Wolfgang

2013-01-01

315

Multiple direct and sequential Auger effect in the rare gases  

Microsoft Academic Search

The use of a magnetic bottle spectrometer with synchrotron radiation allows multi dimensional electron spectroscopy to be performed by detecting in coincidence all electrons (2, 3, 4) ejected in multiple ionization events. Multiple Auger effect following inner-shell ionization can be investigated in this way. Application of the technique to rare gases (Xe 4d and Kr 3d) double Auger decay reveals

F. Penent; P. Lablanquie; J. Palaudoux; L. Andric; T. Aoto; K. Ito; Y. Hikosaka; R. Feifel; J. H. D. Eland

2006-01-01

316

DRE Directions: What Makes an Effective Catechetical Leader?  

ERIC Educational Resources Information Center

Discusses the top ten characteristics of effective Catechetical leaders: (1) prayerful/spiritual people; (2) passion for Catechetical Ministry; (3) creativity; (4) cooperative behavior; (5) active in professional organizations; (6) learns continuously; (7) respected by peers; (8) possesses administrative skills and run creative programs; (9)…

Walters, Thomas P.; Walters, Rita Tyson

2003-01-01

317

Observe how the Coriolis effect influences wind direction  

NSDL National Science Digital Library

This animated series of satellite images shows Earth science students how the Coriolis effect causes winds in the Northern Hemisphere to veer to the right of their predicted course. Movie controls allow students to repeat, pause, or step through the animation, which can give students more time to analyze the images. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

318

Effects of a small seagull colony on trophic status and primary production in a Mediterranean coastal system (Marinello ponds, Italy)  

NASA Astrophysics Data System (ADS)

Colonies of seabirds have been shown to influence nutrient cycling and primary production of coastal areas, but knowledge is still limited above all for smaller colonies. This study evaluates the influence of a small resident seagull colony (Larus michahellis Naumann, 1840) on a Mediterranean coastal system (Marinello ponds, Sicily, Italy). The presence of ornithogenic organic matter from seagull guano was first assessed at increasing distances from the colony using ?15N to indicate the effects of guano on the trophic status and primary production. The pond directly affected by guano deposition showed an anomalous water and sediment chemistry, especially regarding physico-chemical variables (pH), nitrogen isotopic signature, nutrient balance and phytoplankton biomass. These effects were not observed in the adjacent ponds, highlighting pronounced, small spatial-scale variability. Given the worldwide presence of seabird colonies and the scarcity of research on their effect on coastal marine areas, the study shows that seabird-mediated input may be important in influencing ecosystem dynamics of coastal areas, even where both the system in question and the colony are small.

Signa, Geraldina; Mazzola, Antonio; Vizzini, Salvatrice

2012-10-01

319

Climate change and wildlife health: direct and indirect effects  

USGS Publications Warehouse

Climate change will have significant effects on the health of wildlife, domestic animals, and humans, according to scientists. The Intergovernmental Panel on Climate Change projects that unprecedented rates of climate change will result in increasing average global temperatures; rising sea levels; changing global precipitation patterns, including increasing amounts and variability; and increasing midcontinental summer drought (Intergovernmental Panel on Climate Change, 2007). Increasing temperatures, combined with changes in rainfall and humidity, may have significant impacts on wildlife, domestic animal, and human health and diseases. When combined with expanding human populations, these changes could increase demand on limited water resources, lead to more habitat destruction, and provide yet more opportunities for infectious diseases to cross from one species to another. Awareness has been growing in recent years about zoonotic diseases— that is, diseases that are transmissible between animals and humans, such as Lyme disease and West Nile virus. The rise of such diseases results from closer relationships among wildlife, domestic animals, and people, allowing more contact with diseased animals, organisms that carry and transmit a disease from one animal to another (vectors), and people. Disease vectors include insects, such as mosquitoes, and arachnids, such as ticks. Thus, it is impossible to separate the effects of global warming on wildlife from its effects on the health of domestic animals or people. Climate change, habitat destruction and urbanization, the introduction of exotic and invasive species, and pollution—all affect ecosystem and human health. Climate change can also be viewed within the context of other physical and climate cycles, such as the El Niño Southern Oscillation (El Niño), the North Atlantic Oscillation, and cycles in solar radiation that have profound effects on the Earth’s climate. The effects of climate change on wildlife disease are summarized in several areas of scientific study discussed briefly below: geographic range and distribution of wildlife diseases, plant and animal phenology (Walther and others, 2002), and patterns of wildlife disease, community and ecosystem composition, and habitat degradation.

Hofmeister, Erik; Rogall, Gail Moede; Wesenberg, Kathy; Abbott, Rachel; Work, Thierry; Schuler, Krysten; Sleeman, Jonathan; Winton, James

2010-01-01

320

Directional and polarimetric effects in the optical domain  

NASA Technical Reports Server (NTRS)

Papers focused on land surface, atmospheric, and ocean properties are reported. Specific comments pertaining to polarization, models and inversion, and measurements, are given. Recommendations are: continued research into the application potential of the BRDF (Bidirectional Reflectance Distribution Function) and polarization properties of ground surface and atmospheric targets; three dimensional models, which account for the statistical behavior of remotely sensed data, should be extended and inverted in order to support analysis of data potentially covering rolling terrain such that pixels represent heterogeneous mixtures of surface cover types and project ground footprints with sizes between 10 to 6 km, the ground pixel sizes of planned future sensors; available reflectance models should be further validated by means of multi dimensional (directional, spectral, temporal) field data and existing models should be intercompared in more depth to evaluate their performance and limitations; existing methods for model inversion should be validated in more depth in order to quantify the practical limitations and the expected accuracy of the parameters retrieved and new approaches should be developed based upon apriori knowledge of plant canopy development and spectral BRDF properties; there is a need to establish a protocol of validation and intercomparison of the indices and compositing techniques which have been proposed during these last years.

Vanderbilt, V. C.; Leroy, M.

1994-01-01

321

Electrocortical effects of directing attention during visual exposure in dentophobia.  

PubMed

Fear of pain is a main motivator for avoidance or delay of dental treatment in patients afflicted with dentophobia. Studies employing passive viewing paradigms found motivated attention to the phobic object to be associated with enhanced amplitudes of the late positive potential (LPP). The aim of the current study was to investigate, if explicit attention-guiding instructions are able to modify the LPP. Twenty-three patients suffering from dentophobia and 23 controls were presented with pictures showing disorder-relevant or neutral contents, which were combined with different instructions: to distract the attention away from the picture, to classify the content, or to decide whether the scene elicited fear of pain. Relative to controls, dentophobics displayed enhanced late positivity (300-1000ms after picture onset) in the fear of pain condition at frontal and central recording sites, whereas there was no group difference during classification and distraction. Within patients, fear of pain elicited greater positivity than classification and distraction. The findings are discussed within the framework of attentional direction. Future studies could investigate whether psychotherapy differentially affects neural correlates of attention regulation. PMID:24837975

Leutgeb, Verena; Schöngassner, Florian; Schienle, Anne

2014-08-01

322

Predicting and Evaluating the Effectiveness of Ocean Carbon Sequestration by Direct Injection.  

National Technical Information Service (NTIS)

Direct injection of CO2, into the ocean is a potentially effective carbon sequestration strategy. Therefore, we want to understand the effectiveness of oceanic injection and develop the appropriate analytic framework to allow us to compare the effectivene...

K. Caldeira H. J. Herzog M. E. Wickett

2001-01-01

323

Effect of Court Dimensions on Players' External and Internal Load during Small-Sided Handball Games  

PubMed Central

The aim of this study was to investigate the effect of three different court dimensions on the internal and external load during small-sided handball games. Six male amateur handball players took part in this study and participated in three different 8-min 3vs3 (plus goalkeepers) small-sided handball games (each repeated twice). The three court dimensions were 12×24m, 30×15m and 32×16m. Through Global Positioning System devices (SPI pro elite 15Hz, GPSports) and video analysis, the following parameters were recorded: cyclic and acyclic movements (distance covered and number of technical actions executed), heart rate, and rating of perceived exertion (RPE). Total distance travelled increased with court dimensions (885.2m ± 66.6m in 24×12m; 980.0m ± 73.4m in 30×15m; 1095.0m ± 112.9m in 32×16m, p < 0.05). The analysis of distance covered in the four speed zones (0–1.4 m·s-1; 1.4–3.4 m·s-1; 3.4–5.2 m·s-1; >5.2 m·s-1) highlighted substantial differences: playing with the 30×15m court in comparison to the 24×12m, the players covered less distance in the first speed zone (p = 0.012; ES = 0.70) and more distance in the second (p = 0.049; ES = 0.73) and third (p = 0.012; ES = 0.51) speed zones. Statistical differences were also found between the 24×12m and 32×16m courts: the players covered more distance in the second and third speed zones (p = 0.013, ES = 0.76; p = 0.023 ES = 0.69) with the 32×16m court in comparison to the 24×12m. There was no significant effect of court dimensions on the technical parameters (number of team actions, passes, piston movements toward goal and defensive activities), the number of specific handball jumps and changes of direction, and the time spent in the different heart rate zones. Considering the average data of all the experimental conditions together (24×12m, 30×15m, 32×16m), a pronounced statistical difference was highlighted between the values in first two HR zones and the last two (p < 0.05; large ES). The rating of perceived exertion was significantly higher during the drill with the 32×16m court compared with the 24×12m one (p < 0.05; ES = 2.34). Our findings indicate that changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players. Key points To cover the specific game demands, more specific training methodologies have been developed in many sport games. Specific game exercises may provide a useful conditioning stimulus, together with technical and tactical training components. Changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players. The high ratio of cyclic activity per minute and the high HR values recorded during SSHGs make this type of drills extremely useful for aerobic power training.

Corvino, Matteo; Tessitore, Antonio; Minganti, Carlo; Sibila, Marko

2014-01-01

324

Effect of Court Dimensions on Players' External and Internal Load during Small-Sided Handball Games.  

PubMed

The aim of this study was to investigate the effect of three different court dimensions on the internal and external load during small-sided handball games. Six male amateur handball players took part in this study and participated in three different 8-min 3vs3 (plus goalkeepers) small-sided handball games (each repeated twice). The three court dimensions were 12×24m, 30×15m and 32×16m. Through Global Positioning System devices (SPI pro elite 15Hz, GPSports) and video analysis, the following parameters were recorded: cyclic and acyclic movements (distance covered and number of technical actions executed), heart rate, and rating of perceived exertion (RPE). Total distance travelled increased with court dimensions (885.2m ± 66.6m in 24×12m; 980.0m ± 73.4m in 30×15m; 1095.0m ± 112.9m in 32×16m, p < 0.05). The analysis of distance covered in the four speed zones (0-1.4 m·s(-1); 1.4-3.4 m·s(-1); 3.4-5.2 m·s(-1); >5.2 m·s(-1)) highlighted substantial differences: playing with the 30×15m court in comparison to the 24×12m, the players covered less distance in the first speed zone (p = 0.012; ES = 0.70) and more distance in the second (p = 0.049; ES = 0.73) and third (p = 0.012; ES = 0.51) speed zones. Statistical differences were also found between the 24×12m and 32×16m courts: the players covered more distance in the second and third speed zones (p = 0.013, ES = 0.76; p = 0.023 ES = 0.69) with the 32×16m court in comparison to the 24×12m. There was no significant effect of court dimensions on the technical parameters (number of team actions, passes, piston movements toward goal and defensive activities), the number of specific handball jumps and changes of direction, and the time spent in the different heart rate zones. Considering the average data of all the experimental conditions together (24×12m, 30×15m, 32×16m), a pronounced statistical difference was highlighted between the values in first two HR zones and the last two (p < 0.05; large ES). The rating of perceived exertion was significantly higher during the drill with the 32×16m court compared with the 24×12m one (p < 0.05; ES = 2.34). Our findings indicate that changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players. Key pointsTo cover the specific game demands, more specific training methodologies have been developed in many sport games.Specific game exercises may provide a useful conditioning stimulus, together with technical and tactical training components.Changing court dimensions during small-sided handball games can be used to manipulate both external and internal loads on the players.The high ratio of cyclic activity per minute and the high HR values recorded during SSHGs make this type of drills extremely useful for aerobic power training. PMID:24790482

Corvino, Matteo; Tessitore, Antonio; Minganti, Carlo; Sibila, Marko

2014-05-01

325

Effects of ion drift on small-amplitude ion-acoustic solitons  

Microsoft Academic Search

Some properties of small-amplitude ion-acoustic solitons in a plasma consisting of nondrifting electrons and drifting ions are investigated. Electron inertia effects are shown to be considerably more important than relativistic effects. It is also shown that ion-acoustic soliton solutions exist only if the ion drift velocity is less than the electron thermal velocity.

H. H. Kuehl; C. Y. Zhang

1991-01-01

326

Cost-effective small-scale crown-of-thorns starfish eradication procedures using acid injections  

Microsoft Academic Search

An investigation was undertaken to determine the most effective method of controlling the crown-of-thorns starfish (COTS) on small patch reefs. Two acid injection regimes were trialled over an eight month period and both significantly reduced the densities and size classes of COTS on isolated patch reefs. The frequent injection regime (approximately 2 person hours effort per week) was more effective

David Fisk; Lyle Vail; Anne Hoggett

327

Electroviscous effects on pressure-driven flow of dilute electrolyte solutions in small microchannels  

Microsoft Academic Search

A fundamental understanding of the flow characteristics of electrolyte solutions in microchannels is critical to the design and control of microfluidic devices. Experimental studies have shown that the electroviscous effect is appreciable for a dilute solution in a small microchannel. However, the experimentally observed electroviscous effects cannot be predicted by the traditional theoretical model, which involves the use of the

Carolyn L. Ren; Dongqing Li

2004-01-01

328

Effects of elevated water temperature on fish and macroinvertebrate communities below small dams  

Microsoft Academic Search

Many studies have investigated the ecological changes that occur below dams that release cold, hypolimnetic water, but very few studies have looked at the effects of the release of warm, surface waters. The effect of small, surface release dams on downstream thermal regimes is a major habitat concern for many cold-water systems, however. The objective of this study was to

JoAnna L. Lessard; Daniel B. Hayes

2003-01-01

329

Absorbing aerosols above clouds: Getting hold of the direct aerosol effect  

Microsoft Academic Search

Aerosol effects, direct as well as indirect, constitute the biggest uncertainties when it comes to quantifying human induced climate change. Understanding these will thus increase the credibility of climate predictions. This study focuses on the direct aerosol effect when absorbing aerosols reside above clouds. In cloud-free conditions, absorbing aerosols usually exert a negative radiative forcing at TOA due to an

K. Peters; J. Quaas

2009-01-01

330

Academic Self-Concept and Learning Strategies: Direction of Effect on Student Academic Achievement  

ERIC Educational Resources Information Center

This study examined the prediction of academic self-concept (English and Mathematics) and learning strategies (deep and surface), and their direction of effect, on academic achievement (English and Mathematics) of 8,354 students from 16 secondary schools in Hong Kong. Two competing models were tested to ascertain the direction of effect: Model A…

McInerney, Dennis M.; Cheng, Rebecca Wing-yi; Mok, Magdalena Mo Ching; Lam, Amy Kwok Hap

2012-01-01

331

Target- and Effect-Directed Actions towards Temporal Goals: Similar Mechanisms?  

ERIC Educational Resources Information Center

The goal of an action can consist of generating a change in the environment (to produce an effect) or changing one's own situation in the environment (to move to a physical target). To investigate whether the mechanisms of effect-directed and target-directed action control are similar, participants performed continuous reversal movements. They…

Walter, Andrea M.; Rieger, Martina

2012-01-01

332

Endogenous monopsony and the perverse effect of the minimum wage in small firms  

Microsoft Academic Search

The minimum-wage rate has been introduced in many countries as a means of alleviating the poverty of the working poor. This paper shows, however, that an imperfectly enforced minimum-wage rate causes small firms to face an upward-sloping labor supply schedule. Since this turns these firms into endogenous monopsonists, the minimum-wage rate has the perverse effect of reducing employment in small

Leif Danziger

2010-01-01

333

Effectiveness of Health and Safety in Small Enterprises: A Systematic Review of Quantitative Evaluations of Interventions  

Microsoft Academic Search

Introduction This systematic review was conducted to identify effective occupational health and safety interventions for small businesses.\\u000a Methods The review focused on peer-reviewed intervention studies conducted in small businesses with 100 or fewer employees, that\\u000a were published in English and several other languages, and that were not limited by publication date. Multidisciplinary members\\u000a of the review team identified relevant articles

F. Curtis Breslin; Natasha Kyle; Philip Bigelow; Emma Irvin; Sara Morassaei; Ellen MacEachen; Quenby Mahood; Rachel Couban; Harry Shannon; Benjamin C. Amick

2010-01-01

334

Effects of small-sided games on physical conditioning and performance in young soccer players  

Microsoft Academic Search

The purpose of this study was to examine, first, the movement actions performed during two different small-sided games and, second, their effects on a series of field endurance and technical tests. Thirty-four young soccer players (age: 13 ± 0.9 yrs; body mass: 62.3 ± 15.1 kg; height: 1.65 ± 0.06 m) participated in the study. Small-sided games included three-a-side (3

Athanasios Katis; Eleftherios Kellis

2009-01-01

335

The effect of small intramural uterine fibroids on the cumulative outcome of assisted conception  

Microsoft Academic Search

BACKGROUND: This study aimed to evaluate the effect of small intramural fibroids on the cumulative pregnancy, ongoing pregnancy, live birth and implantation rates after three IVF\\/ICSI attempts. METHODS: The first three treatment cycles of women enrolled for IVF\\/ICSI over a 12-month period were analysed. Only patients with small (£5 cm) intramural fibroids not encroaching upon the endometrial cavity were included

Y. Khalaf; C. Ross; T. El-Toukhy; R. Hart; P. Seed; P. Braude

2006-01-01

336

Non-contact small animal fluorescence imaging system for simultaneous multi-directional angular-dependent data acquisition.  

PubMed

We present a novel non-contact small animal fluorescent molecular tomography (FMT) imaging system. At the heart of the system is a new mirror-based imaging head that was designed to provide 360-degree measurement data from an entire animal surface in one step. This imaging head consists of two conical mirrors, which considerably reduce multiple back reflections between the animal and mirror surfaces. These back reflections are common in existing mirror-based imaging heads and tend to degrade the quality of raw measurement data. In addition, the introduction of a novel ray-transfer operator allows for the inclusion of the angular dependent data in the image reconstruction process, which results in higher image resolution. We describe in detail the system design and implementation of the hardware components as well as the transport-theory-based image reconstruction algorithm. Using numerical simulations, measurements on a well-defined phantom and a live animal, we evaluate the system performance and show the advantages of our approach. PMID:25071965

Lee, Jong Hwan; Kim, Hyun Keol; Chandhanayingyong, Chandhanarat; Lee, Francis Young-In; Hielscher, Andreas H

2014-07-01

337

Non-contact small animal fluorescence imaging system for simultaneous multi-directional angular-dependent data acquisition  

PubMed Central

We present a novel non-contact small animal fluorescent molecular tomography (FMT) imaging system. At the heart of the system is a new mirror-based imaging head that was designed to provide 360-degree measurement data from an entire animal surface in one step. This imaging head consists of two conical mirrors, which considerably reduce multiple back reflections between the animal and mirror surfaces. These back reflections are common in existing mirror-based imaging heads and tend to degrade the quality of raw measurement data. In addition, the introduction of a novel ray-transfer operator allows for the inclusion of the angular dependent data in the image reconstruction process, which results in higher image resolution. We describe in detail the system design and implementation of the hardware components as well as the transport-theory-based image reconstruction algorithm. Using numerical simulations, measurements on a well-defined phantom and a live animal, we evaluate the system performance and show the advantages of our approach.

Lee, Jong Hwan; Kim, Hyun Keol; Chandhanayingyong, Chandhanarat; Lee, Francis Young-In; Hielscher, Andreas H.

2014-01-01

338

Direct Effects of Phosphate on Vascular Cell Function  

PubMed Central

Elevated serum phosphate has clinically been associated with vascular stiffness and cardiovascular mortality. Mechanistic studies over the past decade looking at phosphate’s local effects on the vessel wall have lent insight into various pathways that culminate in vascular calcification.Smooth muscle cell phenotype change and apoptosis play prominent roles. The sodium-phosphate cotransporter PiT-1 is required for the osteochondrogenic differentiation of smooth muscle cellsin vitro. Less is known about phosphate-driven valve interstitial cell calcification and elastin degradation.In this paper, we review the current knowledge about phosphate-induced changes in the vascular wall.

Lau, Wei Ling; Pai, Ashwini; Moe, Sharon M.; Giachelli, Cecilia M.

2011-01-01

339

Continuous hyperfractionated accelerated radiotherapy (CHART) and non-conventionally fractionated radiotherapy in the treatment of non-small cell lung cancer: a review and consideration of future directions.  

PubMed

There is a well-established role for radiation treatment in the management of non-small cell lung cancer. As a single modality, it is indicated as a radical treatment option for patients deemed unsuitable for chemotherapy with inoperable locoregional disease or who decline surgery. In this patient group, the evidence shows advantages for accelerated treatment regimes, e.g. continuous hyperfractionated accelerated radiotherapy (CHART). Research efforts should be directed towards dose escalation with the application of the new technologies available. The multi-modality approach of chemoradiotherapy is established in the radical treatment of non-small cell lung cancer in those who are inoperable, radically treatable and fit enough to receive chemotherapy. How best these two modalities are combined remains unclear, and the combination of CHART and other non-conventionally fractionated radiotherapy schedules with chemotherapy and targeted agents is another potentially productive research area. PMID:20399629

Hatton, M Q F; Martin, J E

2010-06-01

340

Noise directivity and group velocity tomography in a region with small velocity contrasts: the northern Baltic shield  

NASA Astrophysics Data System (ADS)

Ambient noise tomography (ANT) is widely used to image strong velocity variations within the upper crust. Using careful processing, we obtained a 3-D model of shear velocities in the upper crust beneath northern Finland, where the lateral velocity variations are less than 3 per cent. As part of the tomography, the noise field is analysed. It is strongly heterogeneous but the signal-to-noise ratio is sufficient to obtain stable dispersion curves for all profile azimuths. Our results show that the directions of dominant noise sources of Rayleigh and Love waves are the same, but the amplitude distribution with azimuth is different for the two types of waves. More intriguingly, the high frequency Love waves are dominated by a mixture of higher modes rather than the fundamental mode. The reconstructed 3-D model shows the Lapland Granulite Belt as a high velocity body with a limit at surface in excellent agreement with geological observations at surface. Following this interface at depth, our results are compatible with previous studies suggesting an Archean north oriented subduction.

Poli, P.; Pedersen, H. A.; Campillo; , M.; Polenet/Lapnet Working Group

2013-01-01

341

Design strategy of small topographical guiding templates for sub-15nm integrated circuits contact hole patterns using block copolymer directed self assembly  

NASA Astrophysics Data System (ADS)

Block copolymer (BCP) directed self-assembly (DSA) is a promising extension of optical lithography for patterning irregularly positioned contact holes of integrated circuits. The small topographical templates are shown to guide the self-assembly off the natural geometry by strong boundary confinement [1-2], and has been demonstrated to pattern 22nm random logic circuits using [2-3]. Here we present a general template design strategy that relates the DSA material properties to the target technology node requirements and experimentally demonstrated DSA contact hole patterning for half adders at the 14 nm and 10 nm nodes.

Yi, He; Bao, Xin-Yu; Tiberio, Richard; Wong, H.-S. Philip

2013-03-01

342

Transient visual effects of prolonged small spot foveal laser exposure. Report for January-March 1989  

SciTech Connect

In recent experiments, the authors evaluated the effects of acute, threshold damage levels of small-spot foveal laser exposure. These experiments revealed transient changes in acuity and contrast sensitivity lasting from 10 to 15 minutes postexposure. Following recovery from such effects, normal acuity and contrast sensitivity are not necessarily degraded, although continuous exposure at these levels does result in parafoveal compensation for foveal damage and eventual deficit in fine visual acuity. Development of a test of foveal function during and after small-spot foveal exposure was the primary objective of this investigation. This objective was accomplished. At retinal damage levels, only a small focal foveal lesion was observed indicating the ability to utilize the fovea during such exposure. Post-exposure recovery effects analyzed for target size and contrast conditions suggest retinal and possibly cortical saturation processes.

Zwick, H.; Robins, D.O.; Magsood, N.

1989-03-01

343

Directly probing the effect of strain on magnetic exchange interactions  

NASA Astrophysics Data System (ADS)

Thin films of transition metal oxides of the perovskite type ABO3 (B = 3d or 4d metal) have revealed abundant examples for strain-driven changes of magnetic ordering. One most popular is the strain-induced ferromagnetic ferroelectric state of otherwise antiferromagnetic paraelectric EuTiO3. Another promising example is the strain control of orbital occupation and magnetic coupling at oxide interfaces of SrRuO3 with manganites. In spite of strong efforts, the theoretical treatment of magnetic exchange in complex oxides has remained a challenge, and experiments continue to show unpredicted / unexplained large effects of the epitaxial strains in films. In order to provide meaningful experimental data on strain dependences, epitaxial thin films should be grown in various coherent strain states on different substrates without changing anything but the strain. This is inherently difficult: possible problems may arise from a strain-dependent oxidation level or microstructure. As a complementary approach, the in-plane strain of epitaxial oxide films can be controlled reversibly using a piezoelectric substrate, even though the accessible reversible strain of 0.1 -- 0.2% is an order of magnitude smaller. In my talk, I will address reversible-strain studies on La0.7Sr0.3MnO3, La1-xSrxCoO3 (x = 0, 0.2, 0.3) und SrRuO3 films, showing the strain response of the magnetic Curie temperature, the magnetization and the electrical resistance and discussing the current understanding of the strain effects on magnetic ordering. In La0.8Sr0.2CoO3, a strain-driven phase transition between ferromagnetic and spin-glass-like could be established by combining the piezoelectric substrate with a tuned buffer system providing varied as-grown strain states. In SrRuO3, a tetragonal tensile strain state shows a suppression of the ordered magnetic moment. Lattice parameters and symmetries of the films were determined by x-ray diffraction. It is noted that the atomic displacements (bond lengths and angles) under strain in these compounds are yet essentially unknown and subject to present research.

Dorr, Kathrin

2012-02-01

344

Small effective population sizes of two remnant ocelot populations ( Leopardus pardalis albescens ) in the United States  

Microsoft Academic Search

Threatened populations are vulnerable to the effects of genetic drift and inbreeding, particularly when gene flow is low and\\u000a the effective population size is small. Estimates of effective population size (N\\u000a \\u000a e\\u000a ) provide important information on the status of endangered populations that have experienced severe fragmentation and serve\\u000a as indicators of genetic viability. Genetic data from microsatellite loci were

Jan E. Jane?ka; M. E. Tewes; L. L. Laack; L. I. Grassman; A. M. Haines; R. L. Honeycutt

2008-01-01

345

Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine.  

PubMed

Diets containing genetically modified (GM) potatoes expressing the lectin Galanthus nivalis agglutinin (GNA) had variable effects on different parts of the rat gastrointestinal tract. Some effects, such as the proliferation of the gastric mucosa, were mainly due to the expression of the GNA transgene. However, other parts of the construct or the genetic transformation (or both) could also have contributed to the overall biological effects of the GNA-GM potatoes, particularly on the small intestine and caecum. PMID:10533866

Ewen, S W; Pusztai, A

1999-10-16

346

Survival after total-body irradiation. 1. Effects of partial small bowel shielding  

SciTech Connect

The small intestine of the rat was shielded during total-body irradiation (TBI) to evaluate the effects of radiation dose and length of intestine shielded on survival. Sprague-Dawley rats were anesthetized in groups of 10. Using aseptic surgical procedures 80, 40, 20, or 10 cm, or none of the proximal or distal small intestine were temporarily exteriorized and shielded during irradiation with photons from an 18-MeV linear accelerator. Less than 17% of the dose was delivered to the shielded intestines. In unshielded animals deaths occurred from Days 4 to 6 with 13, 15, or 17 Gy and from Days 8 to 30 with 9, 11, and 12 Gy. However, in all animals exposed to 15 Gy with all or part of the small intestine shielded, survival was increased to between 5 and 9 days. Shielding of the distal small intestine. The previously identified target of radiation damage in the small intestine is the crypt stem cell. In this study, the analysis of histological specimens of shielded and irradiated small intestine suggested that humoral factors also influence intestinal histology and survival after irradiation. These humoral factors are thought to originate from the irradiated body tissues, the shielded proximal intestine, and the shielded distal intestine. Further studies are required to identify these factors and to determine their mode of action and their therapeutic potential after radiation damage to the small intestine.

Vigneulle, R.M.; Vriesendorp, H.M.; Taylor, P.; Burns, W.; Pelkey, T.

1989-01-01

347

Effect of small flares in the neutral component of secondary cosmic radiation  

NASA Technical Reports Server (NTRS)

The results are presented of an investigation of the effect of small flares, scale divisions 1 and 1(+), in the neutron component of secondary cosmic radiation from the data of neutron supermonitors at the stations of Kiev, Bukhta Tiksi, and Deep River. It is shown that flares of scale divisions 1 and 1(+) are accompanied by an effect in the neutron component amounting to about 0.4%. A mechanism is presented for calculating the outflow of particles accelerated in small flares, owing to diffusion across the magnetic field of a trap.

Bondarenko, V. I.; Raychenko, L. V.; Yukhimuk, A. K.

1974-01-01

348

Effect of monoclonal antibodies to enteroglucagon on ileal adaptation after proximal small bowel resection.  

PubMed Central

On the basis of circumstantial clinical and experimental evidence, it has been suggested that enteroglucagon (EG) may act as an enterotrophic factor. This study was undertaken to evaluate the effects of long term in vivo immunoneutralisation of EG, using monoclonal antibodies to EG, on the hyperplastic ileal response after small bowel resection. Nineteen rats had a 70% proximal resection. A group of 10 rats was given iv 0.5 ml of undiluted hybridoma ascites immediately after the operation and on the 7th day postoperatively. Furthermore 0.025 ml/day of the same hybridoma ascitic fluid was continuously delivered ip for 14 days via mini-osmotic pumps. The hybridoma ascites was prepared from the clone 23.6B4 synthesising a monoclonal antibody directed toward the N-terminal to central region of the glucagon molecule which showed a marked crossreaction with EG. A control group of 9 rats was given a corresponding amount of antibody-free plasmacytoma ascites (Ag 8.653) by the same technique. Seven and 14 days postoperatively there was a plasma anti-EG-antibody excess with an excess binding capacity of 84.9 glucagon eq nM and 88.5 glucagon eq nM respectively. The three dimensional architecture and the proliferative activity of the ileal remnant were evaluated two weeks postoperatively. Despite a continuous immunoneutralisation of circulating endogenous EG by monoclonal antibodies, the adaptive response of the ileal remnants was of the same magnitude as that seen in the control group. These data do not support the hypothesis that EG is a circulating enterotrophic regulatory peptide.

Gregor, M; Menge, H; Stossel, R; Riecken, E O

1987-01-01

349

Modelling the influence of small-scale effects upon the larger scale: an oceanographic challenge  

NASA Astrophysics Data System (ADS)

The problem of resolving or parameterising small-scale processes in oceanographic models and the extent to which small-scale effects influence the large scale are briefly discussed and illustrated for a number of cases. For tides and surges in near-shore regions, the advantages of using a graded mesh to resolve coastal and estuarine small-scale features are demonstrated in terms of a west coast of Britain unstructured mesh model. The effect of mesh resolution upon the accuracy of the overall solution is illustrated in terms of a finite element model of the Irish Sea and Mersey estuary. For baroclinic motion at high Froude number, the effect of resolving small-scale topography within a non-hydrostatic model is illustrated in terms of tidally induced mixing at a single sill, or two closely spaced sills. The question of how to parameterise small-scale non-linear interaction processes that lead to significant mixing, in a form suitable for coarser grid hydrostatic models, is briefly considered. In addition, the importance of topographically induced mixing that occurs in the oceanic lateral boundary layer, namely, the shelf edge upon the large-scale ocean circulation is discussed together with the implications for coarse grid oceanic climate models. The use of unstructured grids in these models to enhance resolution in shelf-edge regions in a similar manner to that used in storm surge models to enhance near coastal resolution is suggested as a suitable “way forward” in large-scale ocean circulation modelling.

Davies, Alan M.; Jones, John Eric; Xing, Jiuxing

2010-08-01

350

The effect of small intestine heterogeneity on irreversible electroporation treatment planning.  

PubMed

Nonthermal irreversible electroporation (NTIRE) is an ablation modality that utilizes microsecond electric fields to produce nanoscale defects in the cell membrane. This results in selective cell death while preserving all other molecules, including the extracellular matrix. Here, finite element analysis and experimental results are utilized to examine the effect of NTIRE on the small intestine due to concern over collateral damage to this organ during NTIRE treatment of abdominal cancers. During previous studies, the electrical treatment parameters were chosen based on a simplified homogeneous tissue model. The small intestine, however, has very distinct layers, and a more realistic model is needed to further develop this technology for precise clinical applications. This study uses a two-dimensional finite element solution of the Laplace and heat conduction equations to investigate how small intestine heterogeneities affect the electric field and temperature distribution. Experimental results obtained by applying NTIRE to the rat small intestine in vivo support the heterogeneous effect of NTIRE on the tissue. The numerical modeling indicates that the electroporation parameters chosen for this study avoid thermal damage to the tissue. This is supported by histology obtained from the in vivo study, which showed preservation of extracellular structures. The finite element model also indicates that the heterogeneous structure of the small intestine has a significant effect on the electric field and volume of cell ablation during electroporation and could have a large impact on the extent of treatment. The heterogeneous nature of the tissue should be accounted for in clinical treatment planning. PMID:24907451

Phillips, Mary

2014-09-01

351

Misinterpreting the Therapeutic Effects of Small Interfering RNA Caused by Immune Stimulation  

Microsoft Academic Search

Activation of innate immunity has direct effects in modulating viral replication, tumor growth, angiogenesis, and inflammatory and other immunological processes. It is now established that unmodified siRNA can acti- vate this innate immune response and therefore there is real potential for siRNA to elicit nonspecific thera- peutic effects in a wide range of disease models. Here we demonstrate that in

Marjorie Robbins; Adam Judge; Ellen Ambegia; Catherine Choi; Ed Yaworski; Lorne Palmer; Kevin McClintock; Ian MacLachlan

2008-01-01

352

Direct and contextual effects of individual values on organizational citizenship behavior in teams.  

PubMed

The authors use Schwartz's values theory as an integrative framework for testing the relationship between individual values and peer-reported organizational citizenship behavior (OCB) in teams, controlling for sex, satisfaction, and personality traits. Using hierarchical linear modeling in a sample of 582 students distributed across 135 class project teams, the authors find positive, direct effects for achievement on citizenship behaviors directed toward individuals (OCB-I), for benevolence on citizenship behaviors directed toward the group (OCB-O), and for self-direction on both OCB-I and OCB-O. Applying relational demography techniques to test for contextual effects, the authors find that group mean power scores negatively moderate the relationship between individual power and OCB-I, whereas group mean self-direction scores positively moderate the relationship between self-direction and both OCB-I and OCB-O. PMID:22369271

Arthaud-Day, Marne L; Rode, Joseph C; Turnley, William H

2012-07-01

353

Long-term horizontal vocal directivity of opera singers: effects of singing projection and acoustic environment.  

PubMed

Vocal directivity refers to how directional the sound is that comes from a singer's mouth, that is, whether the sound is focused into a narrow stream of sound projecting in front of the singers or whether it is spread out all around the singer. This study investigates the long-term vocal directivity and acoustic power of professional opera singers and how these vary among subjects, among singing projections, and among vastly different acoustic environments. The vocal sound of eight professional opera singers (six females and two males) was measured in anechoic and reverberant rooms and in a recital hall. Subjects sang in four different ways: (1) paying great attention to intonation; (2) singing as in performance, with all the emotional connection intended by the composer; (3) imagining a large auditorium; and (4) imagining a small theatre. The same song was sung by all singers in all conditions. A head and torso simulator (HATS), radiating sound from its mouth, was used for comparison in all situations. Results show that individual singers have quite consistent long-term average directivity, even across conditions. Directivity varies substantially among singers. Singers are more directional than the standard HATS (which is a physical model of a talking person). The singer's formant region of the spectrum exhibits greater directivity than the lower-frequency range, and results indicate that singers control directivity (at least, incidentally) for different singing conditions as they adjust the spectral emphasis of their voices through their formants. PMID:20728309

Cabrera, Densil; Davis, Pamela J; Connolly, Anna

2011-11-01

354

Alpha/sub 2/ adrenergic receptors are located prejunctionally in the Auerbach's plexus of the guinea pig small intestine: direct demonstration by radioligand binding  

SciTech Connect

Direct evidence that alpha/sub 2/-receptors in the guinea pig small intestine are localized prejunctionally in neurons of the Auerbach's plexus is presented. The alpha/sub 2/-agonist ligand (/sup 3/H)clonidine bound to a single saturable class of sites with a K/sub d/ of 1-2 nM and a capacity of approximately 70 fmol/mg protein in membranes from the innervated longitudinal and circular muscle layers of the intestine. By a special dissection technique the Auerbach's plexus could be completely removed from the longitudinal muscle. In these denervated preparations the clonidine binding sites were virtually completed removed whereas the expected binding sites observed in innervated controls. The innervated preparations also contained a small number of alpha-receptors as revealed by binding with (/sup 3/H)prazosin (capacity approximately 18 fmol/mg protein with a K/sub d/ of 0.4-0.7 nM). Thus, the present study suggests that alpha/sub 2/-receptors ((/sup 3/H)clonidine binding sites) are localized in neurons (i.e., prejunctionally) in the Auerbach's plexus of the guinea pig small intestine.

Wikberg, J.E.; Lefkowitz, R.J.

1982-12-20

355

Effect Mechanism of a Direct Current on the Solidification of Immiscible Alloys  

NASA Astrophysics Data System (ADS)

Continuous solidification experiments are carried out with Al-Pb alloys under the effect of a direct current. The microstructure evolution in the samples is calculated. The numerical results obtained indicate that a direct current has great effects on the solidification of immiscible alloys. It mainly affects the microstructure evolution during a liquid-liquid decomposition by changing the spatial motions of the minority phase droplets and the temperature field in front of the solidification interface. A sample with either a well dispersed or a core/shell microstructure can be obtained by solidifying Al-Pb alloys under the effect of properly selected direct currents.

Jiang, Hong-Xiang; Zhao, Jiu-Zhou

2012-08-01

356

A uniform model for direct and converse magnetoelectric effect in laminated composite  

NASA Astrophysics Data System (ADS)

Direct and converse magnetoelectric effects are two opposite processes, which were integrated in a model based on equivalent circuit. Following the piezoelectric and magnetostrictive constitutive equations, we obtained magnetic-mechanical-electric equations, and then built a symmetric equivalent circuit about the magnetoelectric coupling. We equivalently analyzed the direct and converse magnetoelectric effects with this equivalent circuit. The numerical calculations fit the reported results very well, including the magnetoelectric changes with the thickness ratio and frequency, the relative lower converse magnetoelectric resonance frequency, and the phase increase of ? around the direct and converse magnetoelectric resonance frequencies. This model helps us understand the magnetoelectric properties deeply, especially for the converse magnetoelectric effect.

Zhou, Jian-Ping; Ma, Yuan-Jun; Zhang, Guang-Bin; Chen, Xiao-Ming

2014-05-01

357

Small group effectiveness in a Caribbean medical school's problem-based learning sessions  

PubMed Central

Purpose: The Tutorial Group Effectiveness Instrument was developed to provide objective information on the effectiveness of small groups. Student perception of small group effectiveness during the problem base learning (PBL) process has not been previously studied in Xavier University School of Medicine (Aruba, Kingdom of the Netherlands); hence, the present study was carried out. Methods: The study was conducted among second and third semester undergraduate medical students during the last week of September 2013, at Xavier University School of Medicine of the Netherlands. Students were informed about the objectives of the study and invited to participate after obtaining written, informed consent. Demographic information like gender, age, nationality, and whether the respondent had been exposed to PBL before joining the institution was noted. Student perception about small group effectiveness was studied by noting their degree of agreement with a set of 19 statements using a Likert-type scale. Results: Thirty-four of the 37 (91.9%) second and third semester medical students participated in the study. The mean cognitive score was 3.76 while the mean motivational and de-motivational scores were 3.65 and 2.51, respectively. The median cognitive category score was 27 (maximum score 35) while the motivation score was 26 (maximum score 35) and the de-motivational score was 12 (maximum score25). There was no significant difference in scores according to respondents’ demographic characteristics. Conclusion: Student perception about small group effectiveness was positive. Since most medical schools worldwide already have or are introducing PBL as a learning modality, the Tutorial Group Effectiveness Instrument can provide valuable information about small group functioning during PBL sessions.

2014-01-01

358

Survival after Total-Body Irradiation. 1. Effects of Partial Small Bowel Shielding.  

National Technical Information Service (NTIS)

The small intestine of the rat was shielded during total-body irradiation (TBI) to evaluate the effects of radiation dose and length of intestine shielded on survival. Sprague-Dawley rats were anesthetized in groups of 10. Using aseptic surgical procedure...

R. M. Vigneulle H. M. Vriesendorp P. Taylor W. Burns T. Pelkey

1989-01-01

359

Spatial Variation in Fish Assemblages across small Mediterranean Drainages: Effects of Habitat and Landscape Context  

Microsoft Academic Search

Much debate about assemblage organization in stream fish may stem from analysing the effects of both local and large-scale processes on assemblage attributes over whole geographic regions. This study addresses this issue, by examining the contribution of local habitat attributes and landscape context to fish assemblage variation across small Mediterranean drainages in southern Portugal. Fish abundance and species composition was

Natacha Mesquita; M. Manuela Coelho; M. Magalhães Filomena

2006-01-01

360

Improving Performance in Very Small Firms through Effective Assessment and Feedback  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to improve assessment and feedback processes in the training practices of very small firms, thereby improving the firms' human capital. Design/methodology/approach: The paper reviews research and practice on effective assessment and feedback. Findings: Based on this paper, human resources are increasingly seen…

Lorenzet, Steven J.; Cook, Ronald G.; Ozeki, Cynthia

2006-01-01

361

Finite Temperature Effects in the Electronic Spectra of Small Metal Clusters  

Microsoft Academic Search

We show that the electronic density of states of small sodium clusters is strongly effected by both thermal fluctuations about the ground state ionic configuration and transitions between different shape isomers as the temperature of the cluster is increased. Contrary to common expectations, the clusters undergo a sharp transition in the temperature range of 100K to 150K after which the

Jeffrey M. Thompson; Aurel Bulgac

1997-01-01

362

The effect of parasitic diseases on nutrient metabolism and productivity in small ruminants  

Microsoft Academic Search

INTRODUCTION<\\/strong>The investigation of voluntary feed intake (VFI) and nitrogen retention (NRET) during parasitic infections in small ruminants is the central theme of this thesis. An attempt was made to examine the effects of trypanosomiasis on feed intake, digestibility, nitrogen retention and animal products. In addition, a similar investigation was conducted during a low to medium level fascioliasis infection in Menz

O. O. Akinbamijo

1994-01-01

363

Holocene Beaver Effects on Small Streams in Yellowstone and Implications for Stream Restoration  

Microsoft Academic Search

It has been asserted that beaver ( Castor canadensis) damming has sustained long-term aggradation and exerted a dominant control on the morphology of small streams over much of North America. However, data on the temporal and spatial dimensions of beaver influence are extremely limited. Using beaver pond deposits and berms (abandoned dams), we document geomorphic effects of beavers on first-

L. P. Persico; G. Meyer

2005-01-01

364

Effect of Blade Planform Variation on the Forward-Flight Performance of Small-Scale Rotors.  

National Technical Information Service (NTIS)

An investigation was conducted in the Glenn L. Martin Wind Tunnel to determine the effect of blade planform variation on the forward-flight performance of four small-scale rotors. The rotors were 5.417 ft in diameter and differed only in blade planform ge...

K. W. Noonan S. L. Althoff D. K. Samak M. D. Green

1992-01-01

365

Long-term effects of precommercial thinning on small mammals in northern Maine  

Microsoft Academic Search

Precommercial thinning (PCT) is being practiced increasingly throughout the Acadian forest of eastern North America to meet silvicultural objectives; however, effects of this practice on wildlife, both immediately and several years post-treatment are not well understood. Forest dependent small mammals have ecological roles as prey for numerous avian and mammalian predators, dispersers of seeds, fruit, and spores, and contribute to

Jessica A. Homyack; Daniel J. Harrison; William B. Krohn

2005-01-01

366

Effects of predator removal on vertebrate prey populations: birds of prey and small mammals  

Microsoft Academic Search

We studied the effects of removal of breeding nomadic avian predators (the kestrel, Falco tinnunculus and Tengmalm's owl, Aegolius funereus) on small mammals (voles of the genera Microtus and Clethrionomys and the common shrew, Sorex araneus) during 1989–1992 in western Finland to find out if these predators have a regulating or limiting impact on their prey populations. We removed potential

Kai Norrdahl; Erkki Korpimäki

1995-01-01

367

The Entrance and Exit Effects in Small Electrochemical Filter-Press Reactors Used in the Laboratory  

ERIC Educational Resources Information Center

A laboratory experiment designed to examine the entrance and exit effects in small electrochemical filter-press reactors used in the laboratory is presented. The single compartment of the filter-press reactor is filled with different turbulence promoters to study their influence as compared to the empty configuration.

Frias-Ferrer, Angel; Gonzalez-Garcia, Jose; Saez, Veronica; Exposito, Eduardo; Sanchez-Sanchez, Carlos M.; Mantiel, Vicente; Walsh, Frank C.; Aldaz, Antonio; Walsh, Frank C.

2005-01-01

368

EFFECTS OF SMALL TRAVEL SPEED VARIATIONS ON ACTIVE VIBRATION CONTROL IN MODERN VEHICLES  

Microsoft Academic Search

A stochastic optimal control procedure, based on a perturbation criterion, is developed to study effects of small travel speed variations on active suspensions of vehicles. The vehicle speed is regarded as an uncertain parameter that randomly varies around a measured (equilibrium) mean value. The approach here separates the active suspension forces into two control (laws) forces. The first force is

E. M. ELBEHEIRY

2000-01-01

369

Effects of Small Travel Speed Variations on Active Vibration Control in Modern Vehicles  

Microsoft Academic Search

A stochastic optimal control procedure, based on a perturbation criterion, is developed to study effects of small travel speed variations on active suspensions of vehicles. The vehicle speed is regarded as an uncertain parameter that randomly varies around a measured (equilibrium) mean value. The approach here separates the active suspension forces into two control (laws) forces. The first force is

E. M. Elbeheiry

2000-01-01

370

The Effect of Small Group Teaching on Acquisition and Transfer of Nonvisual Seriation Abilities.  

ERIC Educational Resources Information Center

The purposes of this study were to investigate: (1) effectiveness of three small group teaching methods on the acquisition and retention of seriation abilities; (2) transfer of seriation abilities using the three treatments; and (3) relationship between visual and nonvisual seriation abilities. One hundred twenty first grade Canadian students were…

Padilla, Michael J.; Ollila, Lloyd

371

Effect of Small-Group Teaching on Acquisition and Transfer of Nonvisual Seriation Abilities.  

ERIC Educational Resources Information Center

Determines the effectiveness of three small-group teaching methods on the acquisition and retention of seriation abilities, investigates transfer of seriation abilities relative to the treatments, and investigates the relationship between visual and nonvisual seriation abilities involving first graders (N=120). (CS)

Padilla, Michael J.; Ollila, Lloyd

1980-01-01

372

Small metal particles: Nonlocal optical properties and quantum-size effects  

Microsoft Academic Search

In this work we survey some recent results concerning non-local optical effects and particle-size dependence for the optical properties of individual metallic particles. We start by giving a historical overview and a conceptual discussion on the subject of small particles, underlining their potential applications. Simplified optical response functions for a metallic sphere are introduced and duly illustrated to bring out

S. P. Apell; J. Giraldo; S. Lundqvist

1990-01-01

373

Are self-directed work teams successful and effective tools for today's organization.  

National Technical Information Service (NTIS)

The purpose of this research is to (1) show the effectiveness and success of self-directed work teams within the organization, (2) emphasize the importance of team building in the success of the team, and (3) assist organizations in building self-directed...

A. D. Arnwine

1995-01-01

374

Direct and indirect effects of white-tailed deer in forest ecosystems  

Microsoft Academic Search

Ungulates can profoundly alter the structure and composition of forest communities via both direct and indirect mechanisms. Individual plant species often respond in a unique way to the direct effect of herbivory as a function of their sensitivity to browse damage, ungulate food preferences, and the density of ungulates present. Sustained browsing pressure can limit the regeneration of favored and

Thomas P. Rooney; Donald M. Waller

2003-01-01

375

The Effects of Direct Training and Treatment Integrity on Treatment Outcomes in School Consultation.  

ERIC Educational Resources Information Center

Study attempts to expand the empirical consultation research base by examining the effects of direct and indirect consultee training methods on treatment integrity and treatment outcomes. A multiple baseline design across consultation dyads was used to investigate the influence of these variables. Results suggest that direct consultee training led…

Sterling-Turner, Heather E.; Watson, T. Steuart; Moore, James W.

2002-01-01

376

Effects of uncertain geoacoustic parameters and coastal shipping densities on shipping noise directionality  

Microsoft Academic Search

The bearing-elevation directionality of low-frequency shipping noise is influenced both by the sediment geoacoustic parameters and by the coastal shipping density. This study examines the effects of geoacoustic parameter and shipping density uncertainties on noise directionality through simulations for a North Pacific site. The simulations are based in part on stochastic models of the spatial variations of geoacoustic parameters that

Thomas J. Hayward; Richard M. Heitmeyer

2005-01-01

377

Compensation for the effects of mutual coupling on direct data domain adaptive algorithms  

Microsoft Academic Search

This paper investigates the effects of mutual coupling between the elements of an array on direct data domain algorithms. Mutual coupling severely undermines the interference suppression capabilities of direct data domain algorithms. The method of moments (MoM) is used to evaluate the mutual coupling between the elements of a given array. The MoM admittance matrix is then used to eliminate

Raviraj S. Adve; Tapan Kumar Sarkar

2000-01-01

378

Impairment of small airways in COPD patients with frequent exacerbations and effects of treatment with tiotropium  

PubMed Central

Disease exacerbations are an important aspect of COPD, because they affect its course and are associated with higher lung function decline. On the other hand, data obtained by biopsies have demonstrated that the progression of COPD is related to an increasing impairment of small airways. We sought to evaluate the small airway impairment (FEF25–75) in two groups of COPD patients (each group had 37 subjects) in relation to the frequency of exacerbations and the effectiveness of treatment with tiotropium bromide on the small airway impairment. The mean number of exacerbations was 3.6/year and 1.38/year in frequent and in infrequent exacerbators, respectively (p < 0.001). The mean value of FEF25–75 at baseline was 624 mL and 865 mL in frequent and in infrequent exacerbators respectively (p = 0.002). The changes in respiratory parameters versus baseline showed increases in mean FEV1, FVC, and FEF25–75 in both groups but only the increase in FEF25–75 in frequent exacerbators was statistically significantly (p = 0.013). During the 3-month period of the study the mean number of exacerbations was 0.66 in frequent and 0.12 in infrequent exacerbators. These findings indicate that COPD patients with frequent exacerbations have a higher impairment of small airways. Treatment with tiotropium in COPD subjects with frequent exacerbations proved to be effective in improving small airway impairment.

Incorvaia, Cristoforo; Riario-Sforza, Gian Galeazzo; Pravettoni, Chiara; Yacoub, Mona-Rita; Frati, Franco

2008-01-01

379

Directed-Inquiry Approach to Learning Science Process Skills: Treatment Effects and Aptitude-Treatment Interactions.  

ERIC Educational Resources Information Center

Investigates the effect of a directed-inquiry approach to learning science process skills and scientific problem solving in the high school biology laboratory. Reports no main effect of the approach but an interaction effect of the approach and cognitive development. (Author/YP)

Germann, Paul J.

1989-01-01

380

Direct and indirect effects of dragonfly ( Anax imperator ) nymphs on green toad ( Bufo viridis ) tadpoles  

Microsoft Academic Search

We conducted an artificial pond experiment to assess the direct and indirect effects of predation on Bufo viridis tadpoles. We ran three treatments: free Anax (unrestrained predatory dragonfly nymph Anax imperator), caged Anax (non-consumptive effects), and control (no Anax). Anax showed both strong consumptive and non-consumptive effects on Bufo tadpoles. Free Anax eliminated all of the tadpoles within six days.

Gil Stav; Burt P. Kotler; Leon Blaustein

2007-01-01

381

Modelling Common Agricultural Policy-Water Framework Directive interactions and cost-effectiveness of measures to reduce nitrogen pollution.  

PubMed

Selecting cost-effective measures to regulate agricultural water pollution to conform to the Water Framework Directive presents multiple challenges. A bio-economic modelling approach is presented that has been used to explore the water quality and economic effects of the 2003 Common Agricultural Policy Reform and to assess the cost-effectiveness of input quotas and emission standards against nitrate leaching, in a representative case study catchment in Scotland. The approach combines a biophysical model (NDICEA) with a mathematical programming model (FSSIM-MP). The results indicate only small changes due to the Reform, with the main changes in farmers' decision making and the associated economic and water quality indicators depending on crop price changes, and suggest the use of target fertilisation in relation to crop and soil requirements, as opposed to measures targeting farm total or average nitrogen use. PMID:20453343

Mouratiadou, Ioanna; Russell, Graham; Topp, Cairistiona; Louhichi, Kamel; Moran, Dominic

2010-01-01

382

Effect of hypokinesia on invertase activity of the mucosa of the small intestine  

NASA Technical Reports Server (NTRS)

The effect of prolonged hypokinesia on the enzyme activity of the middle portion of the small intestine was investigated. Eighty-four mongrel white male rats weighing 170-180 g were divided into two equal groups. The experimental group were maintained in single cages under 30 days of hypokinetic conditions and the control animals were maintained under ordinary laboratory conditions. It is concluded that rates of invertase formation and its inclusion in the composition if the cellular membrane, if judged by the enzyme activity studied in sections of the small intestine, are subject to phase changes in the course of prolonged hypokinesia.

Abdusattarov, A.

1980-01-01

383

Measurements of Siple transmitter signals on the DE 1 satellite - Wave normal direction and antenna effective length  

NASA Technical Reports Server (NTRS)

A new experimental technique is developed to simultaneously measure the wave propagation direction and the effective length of a small (L value much smaller than wavelength) electric dipole antenna on a spin-stabilized satellite in the magnetosphere. The technique relies on the near simultaneous measurement of single components of the electric and magnetic fields of a coherent VLF signal injected into the medium from a ground-based source. The spin fading characteristics of the signal received by the electric dipole and the magnetic loop antenna permit the measurement of the wave normal direction assuming whistler-mode propagation. In-situ and remote measurements of the local cold plasma density are used to determine the refractive index. The wave electric field is then inferred from the wave magnetic field as measured on the loop antenna, the refractive index and the direction of propagation. Comparing this electric field with the measured voltage across the dipole antenna leads to the determination of the effective length of the receiving electric dipole. The technique is applied to data from the Dynamics Explorer 1 satellite observations of whistler mode signals injected into the magnetosphere from the Siple, Antarctica, VLF transmitter. In one case, with the measured background cold plasma density being 15 el/cu cm, the effective length of the 200 m-long electric dipole antenna is found to be 222 + or - 56 m, i.e., about twice the conventional value.

Sonwalker, V. S.; Inan, U. S.

1986-01-01

384

The effect of poverty and social protection on national homicide rates: Direct and moderating effects.  

PubMed

Social protection is the ability of a government to insulate its citizens from the problems associated with poverty and market forces that negatively affect their quality of life. Prior research shows that government policies that provide social protection moderate the influence of inequality on national homicide rates. Recent research, however, reveals a strong association between poverty and national homicide rates. Further, theory and evidence suggest that social protection policies are meant to aid in providing a subsistence level of living, and thus to alleviate the vagaries of poverty not inequality. To this point, however, no studies have examined the potentially moderating effect of social protection on the strength of the association between poverty and homicide rates cross-nationally. We do so in the present study. Employing data for the year 2004 from a sample of 30 nations, we estimate a series of weighted least squares regression models to test three hypotheses: the association between poverty and homicide will remain significant and positive when controlling for social protection, social protection will have a significant negative direct effect on national homicide rates, and social protection will diminish the strength of the poverty-homicide association. The results provided evidence supporting all three hypotheses. We situate our findings in the cross-national empirical literature on social structure and homicide and discuss our results in the theoretical context of social protection. PMID:23521982

Rogers, Meghan L; Pridemore, William Alex

2013-05-01

385

Effects of small time-delays on dynamic output feedback control of offshore steel jacket structures  

NASA Astrophysics Data System (ADS)

This paper investigates the effect of a small time-delay on dynamic output feedback control of an offshore steel jacket structure subject to a nonlinear wave-induced force. First, a conventional dynamic output feedback controller is designed to reduce the internal oscillations of the offshore structure. It is found that the designed controller is of a larger gain in the sense of Euclidean norm, which demands a larger control force. Second, a small time-delay is introduced intentionally to design a new dynamic output feedback controller such that (i) the controller is of a small gain in the sense of Euclidean norm and (ii) the internal oscillations of the offshore structure can be dramatically reduced. It is shown through simulation results that purposefully introducing time-delays can be used to improve control performance.

Zhang, Xian-Ming; Han, Qing-Long; Han, Dongsheng

2011-08-01

386

Radiotelemetric analysis of the effects of prevailing wind direction on Mormon cricket migratory band movement.  

PubMed

During outbreaks, flightless Mormon crickets [Anabrus simplex Haldeman (Orthoptera: Tettigoniidae)] form large mobile groups known as migratory bands. These bands can contain millions of individuals that march en masse across the landscape. The role of environmental cues in influencing the movement direction of migratory bands is poorly understood and has been the subject of little empirical study. We examined the effect of wind direction on Mormon cricket migratory band movement direction by monitoring the local weather conditions and daily movement patterns of individual insects traveling in bands over the same time course at three close, but spatially distinct sites. Although weather conditions were relatively homogeneous across sites, wind directions tended to be more variable across sites during the morning hours, the period during which directional movement begins. Migratory bands at different sites traveled in distinctly different directions. However, we failed to find any evidence to suggest that the observed variation in migratory band movement direction was correlated with local wind direction at any time during the day. These results support the notion that the cues mediating migratory band directionality are likely to be group specific and that a role for landscape-scale environmental cues such as wind direction is unlikely. PMID:18801254

Sword, G A; Lorch, P D; Gwynne, D T

2008-08-01

387

Aminoguanidine Alleviates Radiation-Induced Small-Bowel Damage Through Its Antioxidant Effect  

SciTech Connect

Purpose: To evaluate the effect and its mechanism of aminoguanidine (AG) on small-bowel protection after whole-abdominal irradiation (WAI) in rats. Methods and Materials: Male Sprague-Dawley rats (300-400 g) subjected to 12 Gy WAI were used for the study. Aminoguanidine at a dose of 50-800 mg/kg was administered by the gavage route 2 h before WAI. Mucosal damage of small bowel was evaluated by the grade of diarrhea and crypt survival; oxidative stress was determined by the level of 8-hydroxy 2'-deoxyguanosine (8-OHdG) with immunohistochemistry (IHC). Nitrosative stress was evaluated by the expression of inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (3-NT) with IHC, and systemic and portal vein NOx (nitrite + nitrate) levels were measured and compared with and without AG treatment after WAI. Results: Aminoguanidine showed a dose-dependent effect against WAI-induced diarrhea. Aminoguanidine at a dose of 400 mg/kg had the best protective effect, from 92% to 17% (p = 0.002). Aminoguanidine increased crypt survival from 23% to 46% (p = 0.003). It also significantly attenuated 8-OHdG expression but not 3-NT and iNOS expression at both 4 and 8 h after 12-Gy WAI. Aminoguanidine did not alter the portal vein NOx levels 4 and 8 h after 12-Gy WAI. Conclusion: Aminoguanidine has a radioprotective effect against radiation-induced small-bowel damage due to its antioxidant effect but not inhibition of nitric oxide production. Dietary AG may have a potentially protective effect on the small intestine of patients subjected to pelvic and abdominal radiotherapies.

Huang, E.-Y. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); School of Traditional Chinese Medicine, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Wang, F.-S. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Medical Research, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Lin, I-H. [Department of Radiation Oncology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Yang, Kuender D. [Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Medical Research, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan (China)], E-mail: yangkd@adm.cgmh.org.tw

2009-05-01

388

Comparison of the small angle X-ray scattering study of sulfonated poly(etheretherketone) and Nafion membranes for direct methanol fuel cells  

NASA Astrophysics Data System (ADS)

The microstructural evolution and swelling behaviors of sulfonated poly(etheretherketone) (SPEEK) and Nafion polymer membranes have been investigated by small angle X-ray scattering (SAXS) after equilibrating them in 2 M methanol solution at various temperatures, which is relevant for their use in direct methanol fuel cells (DMFC). The relationships among Bragg distance, sulfonation levels of the membrane, equilibrating temperature and transport properties are discussed. The proton conduction properties of the SPEEK and Nafion membranes have been investigated by electrochemical impedance spectroscopy. The network cluster model is employed to retrieve the structural information from the scattering and proton conductivity data. While the SPEEK membranes have narrower pathways for methanol/water permeation at T < 70 °C, the Nafion membranes have a wider channel even at lower temperatures, resulting in a higher methanol permeability in the latter. Based on the differences in the structural/cluster evolutions, the advantages and limitations of the two polymer membranes for use in DMFC are discussed.

Yang, B.; Manthiram, A.

389

Combining an EGFR directed tyrosine kinase inhibitor with autophagy-inducing drugs: a beneficial strategy to combat non-small cell lung cancer.  

PubMed

The potential therapeutic value of combinatorial regimens based on an EGF receptor tyrosine kinase inhibitor (TKI) and autophagy inducing drugs was evaluated by comparing their molecular impacts on H1299 and A549 non-small cell lung cancer (NSCLC) cells, which overexpress wild type EGF receptor, but are either deficient or have wild type p53 alleles, respectively. We show that H1299 cells display a considerably lower sensitivity to erlotinib treatment, which can be restored by combining erlotinib with rapamycin or with imatinib, though to a lesser extent. Cytotoxicity was associated with increased autophagy and hyperpolarization of the mitochondrial membrane potential. Therefore, combining an EGF receptor directed TKI with an autophagy-inducing drug, preferably, rapamycin, might be beneficial in treating poor responding NSCLC patients. PMID:21807458

Gorzalczany, Yaara; Gilad, Yuval; Amihai, Dina; Hammel, Ilan; Sagi-Eisenberg, Ronit; Merimsky, Ofer

2011-11-28

390

Interpolated task effects on direct and mediated false recognition: effects of initial recall, recognition, and the ironic effect of guessing.  

PubMed

In two experiments, participants studied two types of word lists. Direct lists were taken from the Deese-Roediger-McDermott (DRM) paradigm (e.g., water, bridge, run) and contained words directly related to a nonpresented critical item (CI; e.g., river, Roediger & McDermott, 1995). Mediated lists (e.g., faucet, London, jog) contained words related to the CI through a nonpresented mediator. After each study list, participants completed either a recall test, a recall test with a warning about the CI, arithmetic problems, or a recognition test, or they guessed the CI. On a final recognition test, both warning and guessing decreased direct false recognition but increased mediated false recognition, an ironic effect of guessing. An initial recognition test also increased final mediated false recognition. We argue that warning and guessing tasks strengthened associative pathways to the CI, increased the accessibility of associated mediators, and increased monitoring for the CI at test. Increased monitoring was able to reduce CIs from direct, but not mediated, lists. PMID:22642236

Huff, Mark J; Coane, Jennifer H; Hutchison, Keith A; Grasser, Elisabeth B; Blais, Jessica E

2012-11-01

391

Effect of downed woody debris on small mammal anti-predator behavior.  

SciTech Connect

Anti-predator behavior can affect prey growth, reproduction, survival, and generate emergent effects in food webs. Small mammals often lower the cost of predation by altering their behavior in response to shrubs,but the importance of other microhabitat features, such as downed woody debris, for anti-predator behavior is unknown. We used givingup densities to quantify the degree to which downed woody debris alters perceived predation risk by small mammals in southeastern pineforests. We placed 14 foraging trays next to large downed woody debris,shrubs, and in open areas for 12 consecutive nights. Moon illumination, a common indicator of predation risk, led to a similar reduction in small mammal foraging in all three microhabitats (open, downed woody debris,and shrub). Small mammals perceived open microhabitats as riskier than shrub microhabitats, with downed woody debris habitats perceived as being of intermediate risk between shrub and open microhabitats. Despite the presumed benefits of the protective cover of downed woody debris, small mammals may perceive downed woody debris as a relatively risky foraging site in southeastern pine forests where the high diversity and abundance of rodent-eating snakes may provide a primary predatory threat.

Hinkleman, Travis, M.; Orrock, John, L.; Loeb, Susan, C.

2011-10-01

392

The Acetylenic Tricyclic Bis(cyano enone), TBE-31 Inhibits Non-Small Cell Lung Cancer Cell Migration through Direct Binding with Actin.  

PubMed

The migratory and invasive potential of the epithelial-derived tumor cells depends on epithelial-to-mesenchymal transition (EMT) as well as the reorganization of the cell cytoskeleton. Here, we show that the tricyclic compound acetylenic tricyclic bis(cyano enone), TBE-31, directly binds to actin and inhibits linear and branched actin polymerization in vitro. Furthermore, we observed that TBE-31 inhibits stress fiber formation in fibroblasts as well as in non-small cell lung cancer cells during TGF?-dependent EMT. Interestingly, TBE-31 does not interfere with TGF?-dependent signaling or changes in E-cadherin and N-cadherin protein levels during EMT. Finally, we observed that TBE-31 inhibits fibroblast and non-small cell lung tumor cell migration with an IC50 of 1.0 and 2.5 ?mol/L, respectively. Taken together, our results suggest that TBE-31 targets linear actin polymerization to alter cell morphology and inhibit cell migration. Cancer Prev Res; 7(7); 727-37. ©2014 AACR. PMID:24806663

Chan, Eddie; Saito, Akira; Honda, Tadashi; Di Guglielmo, Gianni M

2014-07-01

393

New technique for the direct analysis of food powders confined in a small hole using transversely excited atmospheric CO(2) laser-induced gas plasma.  

PubMed

Taking advantage of the differences between the interactions of transversely excited atmospheric (TEA) CO(2) lasers with metal and with organic powder, a new technique for the direct analysis of food powder samples has been developed. In this technique, the powder samples were placed into a small hole with a diameter of 2 mm and a depth of 3 mm and covered by a metal mesh. The TEA CO(2) laser (1500 mJ, 200 ns) was focused on the powder sample surfaces, passing through the metal mesh, at atmospheric pressure in nitrogen gas. It is hypothesized that the small hole functions to confine the powder particles and suppresses the blowing-off of sample, while the metal mesh works as the source of electrons to initiate the strong gas breakdown plasma. The confined powder particles are then ablated by laser irradiation and the ablated particles move into the strong gas breakdown plasma region to be atomized and excited; this method cannot be applied for the case of Nd:YAG lasers because in such case the metal mesh itself was ablated by the laser irradiation. A quantitative analysis of a milk powder sample containing different concentrations of Ca was successfully demonstrated, resulting in a good linear calibration curve with high precision. PMID:19094393

Khumaeni, Ali; Ramli, Muliadi; Deguchi, Yoji; Lee, Yong Inn; Idris, Nasrullah; Kurniawan, Koo Hendrik; Lie, Tjung Jie; Kagawa, Kiichiro

2008-12-01

394

Effect of a neuroactive steroid infused into the cerebral ventricles of fetal sheep in utero using small infusion volumes.  

PubMed

Placental progesterone metabolites may influence fetal behaviour during late gestation. We have investigated the effect of the neuroactive metabolite, pregnanolone, on the sleep/awake behaviour of fetal sheep. These studies can only be effectively performed in unanesthetized animals with chronically implanted leads and catheters. The relatively large internal volumes of these catheters raises problems for cerebroventriclear infusions. Therefore, we developed a device with negligible deadspace ( approximately 10 microl) consisting of a ventricular cannula attached to a small cap which allowed the instillation of microl volumes of neuroactive steroids into a cerebral ventricle of fetal sheep in utero. Two catheters attached to the cap allow it to be filled in a push-pull configuration. The smaller internal diameter of the ventricular cannular prevents the solution entering the ventricle until the outflow catheter is occluded and solution is forced through the probe. Using this device, the infusion of 5beta-pregnane-3alpha-ol-20-one (pregnanolone, 1 mg), in 35% hydroxypropyl-beta-cyclodextrin, resulted in a marked suppression of fetal behaviour parameters indicative of arousal, while vehicle alone did not affect these parameters. We conclude that neuroactive steroids can be infused into the cerebroventricular system of chronically catheterised fetal sheep in small volumes and that pregnanolone may act directly to influence fetal behaviour. PMID:10771073

Hirst, J J; Egodagamage, K C; Walker, D W

2000-04-01

395

The effect of urban street gang densities on small area homicide incidence in a large metropolitan county, 1994-2002.  

PubMed

The presence of street gangs has been hypothesized as influencing overall levels of violence in urban communities through a process of gun-drug diffusion and cross-type homicide. This effect is said to act independently of other known correlates of violence, i.e., neighborhood poverty. To test this hypothesis, we independently assessed the impact of population exposure to local street gang densities on 8-year homicide rates in small areas of Los Angeles County, California. Homicide data from the Los Angeles County Coroners Office were analyzed with original field survey data on street gang locations, while controlling for the established covariates of community homicide rates. Bivariate and multivariate regression analyses explicated strong relationships between homicide rates, gang density, race/ethnicity, and socioeconomic structure. Street gang densities alone had cumulative effects on small area homicide rates. Local gang densities, along with high school dropout rates, high unemployment rates, racial and ethnic concentration, and higher population densities, together explained 90% of the variation in local 8-year homicide rates. Several other commonly considered covariates were insignificant in the model. Urban environments with higher densities of street gangs exhibited higher overall homicide rates, independent of other community covariates of homicide. The unique nature of street gang killings and their greater potential to influence future local rates of violence suggests that more direct public health interventions are needed alongside traditional criminal justice mechanisms to combat urban violence and homicides. PMID:19247837

Robinson, Paul L; Boscardin, W John; George, Sheba M; Teklehaimanot, Senait; Heslin, Kevin C; Bluthenthal, Ricky N

2009-07-01

396

Advanced dynamical models for very well observed asteroids : perturbations from small bodies, relativity, non - gravitational effects.  

NASA Astrophysics Data System (ADS)

The availability of radar data and high precision optical observations has increased the number of objects with a very well constrained orbit, especially for those objects with a long observed arc. In these cases, the uncertainty of orbital predictions is often dominated by the inaccuracy of the dynamical model. However, the motion of small solar system bodies poses a serious challenge in modeling their dynamics. In particular, for those objects with a chaotic motion small differences in the model are amplified with propagation. Thus, we need to take into account small perturbations too, especially for long - term prediction. An improved dynamical model is relevant in several applications such as assessing the risk of an impact between an asteroid and the Earth. The N - body model describing the motion of a small solar system body includes the Newtonian attraction of the planets. The contribution o f other perturbing bodies has to be taken into account. We propose to include the Moon, two dwarf planets (Ceres and Pluto) and fifteen asteroids (Pallas, Vesta, Juno, Metis, Hygiea, Eunomia, Psyche, Amphitrite, Euphrosyne, Europa, Cybele, Sylvia, Davida, Herculina, Interamnia). The next step is the introduction of the relativity terms due to both the Sun and the planets . Despite their small magnitude, planetary relativistic terms turn out to be relevant for objects experiencing close approaches with a planet. Finally, we discuss non - gravitational effects such as solar radiation pressure and the Yarkovsky effect. In particular, the latter acts as a tiny but secular semimajor axis drift that may decisively drive long - term predictions. These non - gravitational effects are difficult to model as they depend on object ’ s physical properties that are typically unknown. However, a very well observed object can have an orbit precise enough to allow the determination of the parameters defining a non - gravitational perturbation and thus the modeling of the corresponding acceleration.

Bernardi, Fabrizio; Farnocchia, Davide; Milani, Andrea

2012-08-01

397

5-Hydroxytryptamine and human small intestinal motility: effect of inhibiting 5-hydroxytryptamine reuptake.  

PubMed Central

Parenteral 5-hydroxytryptamine stimulates small intestinal motility, but the effect of continuous stimulation with 5-hydroxytryptamine on the human migrating motor complex is unknown. Using a selective 5-hydroxytryptamine reuptake inhibitor, paroxetine, this study investigated the effect of indirect 5-hydroxytryptamine agonism on fasting small intestinal motility and transit. Eight healthy subjects were studied while receiving paroxetine 30 mg daily for five days and while receiving no treatment, in random order. Ambulant small intestinal motility was recorded from five sensors positioned from the duodenojejunal flexure to the ileum for 16-18 hours. Paroxetine reduced the migrating motor complex periodicity mean (SEM) from 81 (6) min to 67 (4) min (p < 0.05), and increased the propagation velocity of phase III from 3.1 to 4.7 cm/min in the proximal jejunum (p < 0.01), and from 1.6 to 3.4 cm/min distally (p < 0.001). Orocaecal transit time measured by lactulose hydrogen breath test was reduced by paroxetine from 70 (9) min to 48 (7) min (p < 0.05). These data suggest that 5-hydroxytryptamine participates in the control of migrating motor complexes in humans, and that selective 5-hydroxytryptamine reuptake inhibitors have a prokinetic action in the human small intestine.

Gorard, D A; Libby, G W; Farthing, M J

1994-01-01

398

A Review on the Effects of Soccer Small-Sided Games  

PubMed Central

Over the last years there has been a substantial growth in research related to specific training methods in soccer with a strong emphasis on the effects of small-sided games. The increase of research in this topic is coincident with the increase of popularity obtained by specific soccer conditioning, which involves training players to deal with soccer match situations. Given the limited time available for fitness training in soccer, the effectiveness of small-sided games as a conditioning stimulus needs to be optimized to allow players to compete at the highest level. Available studies indicate that physiological responses (e.g. heart rate, blood lactate concentration and rating of perceived exertion), tactical and technical skill requirements can be modified during small-sided games by altering factors such as the number of players, the size of the pitch, the rules of the game, and coach encouragement. However, because of the lack of consistency in small-sided games design, player fitness, age, ability, level of coach encouragement, and playing rules in each of these studies, it is difficult to make accurate conclusions on the influence of each of these factors separately.

Aguiar, Marco; Botelho, Goreti; Lago, Carlos; Macas, Victor; Sampaio, Jaime

2012-01-01

399

Measurement of rainfall distribution on a small catchment for the evaluation of canopy interception effects  

NASA Astrophysics Data System (ADS)

Variability of rainfall and throughfall is an essential characteristic of the water balance at spatial scales ranging from meters to hundreds of meters or even kilometers. The amount of throughfall is governed by the characteristics of the vegetation canopy and the involved interception and stemflow effects. In initial, developing ecosystems, distinct patterns of the growing vegetation (e.g. patchiness) supposedly govern the spatial distribution of water in the system, thereby initiating and supporting hydro-ecological feedback processes. Questions are i) is the spatial variability of vegetation relevant for the system as a whole, and ii) how does the distribution of the effective precipitation (i.e. the infiltration) change over time in dependency of vegetation succession? We present the first results of a spatially distributed measurement approach of surface-near precipitation on the constructed catchment "Hühnerwasser" ("Chicken Creek"). The 6-ha site is located in the recultivation area of the lignite open-cast mine "Welzow-Süd" in Lower Lusatia, Brandenburg, Germany. Here, the free development of an initial ecosystem is investigated since September 2005. After eight years of succession, the spatial distribution of plant species is highly heterogeneous, and gains increasing influence on throughfall patterns, thus impacting the distribution of soil humidity and possibly even surface runoff. For spatially distributed precipitation measurement, 47 tipping bucket rain gauges were installed in heights of 0.5 m and 1.0 m along two transects on the catchment. Rain gauge data were collected by a wireless sensor node network provided by the Sens4U joint research project. The transects run NW-SE and NE-SW and cover the range of plant communities presently existing in the ecosystem: locust copses, dense sallow thorn bushes and reeds, base herbaceous and medium-rise small-reed vegetation, and open areas covered by moss and lichens. The raw measurement data were temporally aggregated using a VBA script in order to characterize interception for various types of precipitation events on different time scales. First results from the measurement period 17th July - 3rd September 2013 widely exhibit a good accordance with reference data from on-site weather stations for sites on open ground, while canopy sites show more heterogeneous values, either due to interception or due to canopy collection effects. However, it was found that the explanation of the differences between comparable sites requires an additional inclusion of other relevant parameters, e.g. wind speed and direction, screening effects, and specific canopy characteristics. Moreover, extreme precipitation events sometimes seemed to lead to incorrect measurements either by the sensor and / or node, which required supplementary quality controls of equipment and data. Results from future long-term measurements on the "Hühnerwasser" catchment will be used to identify possible plant-soil feedback mechanisms and to parameterize models that simulate the behavior of initial eco-hydrological systems.

Maurer, Thomas; Schapp, Andrea; Büchner, Steffen; Menzel, Hannes; Hinz, Christoph

2014-05-01

400

Velocity-weakening behavior of plagioclase and pyroxene gouges and stabilizing effect of small amounts of quartz under hydrothermal conditions  

NASA Astrophysics Data System (ADS)

We investigated properties of frictional sliding of plagioclase, pyroxene, and their mixture gouges with a small amount of hornblende, biotite, and quartz as accessory minerals, under hydrothermal conditions with an effective normal stress of 200 MPa, pore pressure of 30 MPa, and temperatures from 100°C to 600°C. Axial loading rate was stepped between 0.001 and 0.0001 mm/s to acquire the rate dependence. Both plagioclase and pyroxene gouges showed velocity-weakening behavior in the whole temperature range except the velocity-strengthening behavior of pyroxene at 200°C. For temperatures above 400°C, both plagioclase and pyroxene gouges showed oscillatory slips, as a result of small dc values of 3-4 µm which make the critical stiffness rise remarkably and approach the system stiffness. Above 300°C, the direct effect of plagioclase shows an increasing trend with temperature, indicating control of the deformation process by thermally activated mechanisms. As the difference of a and b values here are only 20% at most, this trend also applies to the evolution effect. Our analytical derivation based on the theory of pressure solution shows a log-linear contact area growth with time that corresponds to an evolution effect, and estimations based on this encompass the plagioclase data, though the identification of actual mechanisms is not easy. Finally, it is found that a little quartz (3-5%) added to the plagioclase (60-62%)-pyroxene (35%) mixture has a strong stabilizing effect, leading to a transition from velocity weakening to velocity strengthening. These results may help constrain the depth range of seismic slips on deep faults in the lower crust of gabbroic composition.

He, Changrong; Luo, Li; Hao, Quan-Ming; Zhou, Yongsheng

2013-07-01

401

The effects of interaction between large and small diameter fiber systems on the somatosensory evoked potential.  

PubMed

The effect of interaction between large and small diameter fiber systems on the somatosensory evoked potential (SEP) was studied in anesthetized cats. Activation of large diameter fibers of the peroneal or radial nerves eliminates the late components of the SEP produced by stimulation of all fibers in the contralateral median or radial nerves. The inhibitory effects of a selective conditioning stimulus to the large diameter fibers of the peroneal nerve on the radial nerve evoked SEP was eliminated by bilateral transection of the dorsal column and spino-cervical tracts. However, interaction could still be obtained following transection when both large and small diameter fibers in the peroneal nerve were stimulated. The results of this study support the hypothesis that a correlation exists between activity in different fiber groups in afferent nerves, their conduction pathways through the cord, and the components of the cortical evoked potential. PMID:78821

Katz, S; Martin, H F; Blackburn, J G

1978-07-01

402

Do small-scale exclosure\\/enclosure experiments predict the effects of large-scale extirpation of freshwater migratory fauna?  

Microsoft Academic Search

A variety of theoretical and empirical studies indicate that the abilities of small-scale experiments to predict responses\\u000a to large-scale perturbations vary. Small-scale experiments often do not predict the directions of large-scale responses, and\\u000a relatively few empirical studies have examined whether small-scale experiments predict the magnitudes of large-scale responses.\\u000a Here we present an empirical example of small-scale manipulations predicting not only

Effie A. Greathouse; Catherine M. Pringle; William H. McDowell

2006-01-01

403

Direct Effect of Human Immunodeficiency Virus Protease Inhibitors on Neutrophil Function and Apoptosis via Calpain Inhibition  

Microsoft Academic Search

Impairment of neutrophil functions and high levels of apoptotic neutrophils have been reported in human immunodeficiency virus (HIV) patients. The aim of the present study was to investigate the direct in vitro effects of the different HIV protease inhibitors (PIs) on neutrophil functions and apoptosis and to explore their mechanisms of action. The effects of nelfinavir (NFV), saquinavir (SQV), lopinavir

Nurit Hadad; Rachel Levy; Francisc Schlaeffer; Klaris Riesenberg

2007-01-01

404

Improved compensation for the mutual coupling effect in a dipole array for direction finding  

Microsoft Academic Search

A new and practical method is proposed to compensate for the mutual coupling effect in a dipole array deployed for direction finding. This method does not require either the current distributions on the antenna elements or the elevation angles of the incoming signals to be known. A new definition of mutual impedance is introduced to characterize the effect due to

H. T. Hui

2003-01-01

405

Social support, life events and psychiatric symptoms: A study of direct, conditional and interaction effects  

Microsoft Academic Search

The relationships of life event stress, social support and coping style on three measures of psychiatric symptoms were explored using data from 220 parents of chronically ill children. Significant direct and conditional effects between the independent variables on the dependent measures were demonstrated, but there was almost no evidence of any additional interaction effects. The data support the inclusion of

M. I. Frydman

1981-01-01

406

Direct and Indirect Effects of Teenage Body Weight on Adult Wages. NBER Working Paper No. 15027  

ERIC Educational Resources Information Center

Previous estimates on the association between body weight and wages in the literature have been contingent on education and occupation. This paper examines the direct effect of BMI on wages and the indirect effects operating through education and occupation choice, particularly for late-teen BMI and adult wages. Using the National Longitudinal…

Han, Euna; Norton, Edward C.; Powell, Lisa M.

2009-01-01

407

Effects of Transcranial Direct Current Stimulation (tDCS) on Behaviour and Electrophysiology of Language Production  

ERIC Educational Resources Information Center

Excitatory anodal transcranial direct current stimulation (A-tDCS) over the left dorsal prefrontal cortex (DPFC) has been shown to improve language production. The present study examined neurophysiological underpinnings of this effect. In a single-blinded within-subject design, we traced effects of A-tDCS compared to sham stimulation over the left…

Wirth, Miranka; Rahman, Rasha Abdel; Kuenecke, Janina; Koenig, Thomas; Horn, Helge; Sommer, Werner; Dierks, Thomas

2011-01-01

408

Team diversity and leadership: Tests of model of process and direct effects  

Microsoft Academic Search

A model was tested to examine relationships among leadership behaviors, team diversity, and team process measures with team performance and satisfaction at both the team and leader-member levels of analysis. Relationships between leadership behavior and team demographic and cognitive diversity were hypothesized to have both direct effects on organizational outcomes as well as indirect effects through team processes. Leader member

Kevin Brian Lowe

1997-01-01

409

HETEROSIS, DIRECT AND MATERNAL ADDITIVE EFFECTS ON RABBIT GROWTH AND CARCASS CHARACTERISTICS  

Microsoft Academic Search

A total of 142 male and female rabbits of two breed s, Californian (CA) and New-Zealand White (NZ), and their reciprocal crosses were used. This study aimed to estimate heterosis, direct and maternal additive effects as well as some non genetic effect s on rabbit growth and carcass characteristics in order to identify the best crossbreeding plan to us e

410

The Direct Detection Effect in the Hot-Electron Bolometer Mixer Sensitivity Calibration  

NASA Astrophysics Data System (ADS)

We investigate an error in the noise temperature measurements of the hot-electron bolometer mixers caused by the so-called "direct detection effect". The effect originates in the changing of the mixer parameters when the mixer is loaded on calibration black body sources at different temperatures (300 and 77 K). A correction factor was obtained from the mixer output power versus the bias current dependence, measured by: 1) the local oscillator (LO) power tuning: 2) mixer heating: and 3) application of an external RF source. Furthermore, the direct detection effect was assessed by elimination of the heterodyne response using a LO frequency, which is far off the mixer RF band. We show that the direct detection effect can be mitigated by using an isolator between the mixer and the IF amplifier.

Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Kollberg, Erik L.; Angelov, Iltcho

2007-03-01

411

Looking the Other Way: The Role of Gaze Direction in the Cross-race Memory Effect  

PubMed Central

One of the most replicable findings reported in the social psychological literature is the cross-race memory effect. We argue this effect derives from higher-order interactions among social cues that determine the perceived relevance of a face to an observer. The current research tested this hypothesis by examining the combined influences of eye gaze direction and race on face memory. The physical subtlety of eye gaze belies its powerful influence on social perception, and in this case helps specify the relevance of same- versus other-race faces. We found that only in faces making direct eye contact—not those displaying averted eye gaze—was the cross-race memory effect evident. Likewise, only in same-race faces did direct relative to averted gaze enhance face memory. These findings have implications for our general understanding of the combinatorial nature of social perception and help clarify the underlying cause of the cross-race memory effect.

Adams, Reginald B.; Pauker, Kristin; Weisbuch, Max

2010-01-01

412

Original Observation of Definable Single-electron Particle Effects on Individual, Small Fabricated Circuit "elements".  

NASA Astrophysics Data System (ADS)

We are still not at the state of using single, isolated molecules as individual circuit components but one can make sufficiently small multi-molecule components that individual electron transport in electrical usage will be relevant (as if the component were a microscopic molecule to some extent). As shown in our past decade publication of the awarded research, ( "Observation of Single-Electron Charging Effects in Small Tunnel Junctions", T. A. Fulton and G. J. Dolan, Phys. Rev. Lett. 59, 109 (1987).) individual single electron effects could be effective and observable in the characteristics of a small but lithographically fabricated thin film circuit "element". I will predominantly be reviewing and re-describing the particular techniques and requirements to produce the effect at that time. I will also re-cite and describe certain relevant earlier studies, (I. Giaever and H. R. Zeller, Phys. Rev. Lett. 29, 1504 (1968); H. R. Zeller and I. Giaever, Phys. Rev. Lett. 181, 789 (1969). D. V. Averin and K. K. Likharev, J. Low Temp. Phys. 62, 345 (1986). D. V. Averin and K. K. Likharev, J. Low Temp. Phys. 62, 345 (1986)) will cite one significantly similar work accomplishment at a similar time, footnote L. S. Kuzmin and K. K. Likharev, Pis'ma Zh. Eksp. Teor. Fiz 45, 389(1987) [JETP Lett. 45, 495 (1987)]. and will allude to some more recent work on even smaller circuit elements, including that in several students' theses. /footnote.U. of P. Ph. D. theses of Dr. .Dan Grupp, Dr. Ning Yue, Dr. Tao Zhang. It is important to emphasize that we will eventually be in the state of manufacturing and using isolated molecules (at least very small fabricated components) as individual circuit components.

Dolan, G. J.

2000-03-01

413

Effect of cholera enterotoxin on carbohydrate metabolism in the liver and small intestinal mucosa of rabbits  

SciTech Connect

The effect of cholera enterotoxin injected in vivo on glucose formation from alanine, and also on glucose-6-phosphatase activity in the liver and mucosa of the small intestine was studied. L-(2,3-/sup 3/H)-alanine was added to the incubation medium. Chromatograms were developed with 5% AgNO/sub 3/ with the addition of an aqueous solution of ammonia. The quantity of radioactive glucose was determined in a scintillation counter.

Vengrov, P.R.; Cherkasova, T.D.; Yurkiv, V.A.; Pokrovskii, V.I.

1987-09-01

414

Effects of Streptozotocin-Induced Diabetes on Kv Channels in Rat Small Coronary Smooth Muscle Cells  

Microsoft Academic Search

Diabetes impairs endothelium dependent vasodilation, but the mechanism of endothelium independent dilation is not well understood. In the present study, we examined the effect of streptozotocin (STZ)-induced diabetes on the vasomotor of small coronary artery and the activity of voltage-dependent K + channel of vascular smooth muscle cells in STZ rat using the videomicroscopy and patch clamp method. STZ-induced diabetes

Qiang Chai; Zhixiang Liu; Lianbi Chen

2005-01-01

415

Effects of mosapride on motility of the small intestine and caecum in normal horses after jejunocaecostomy  

Microsoft Academic Search

The purpose of the present study was to evaluate the prokinetic effects of mosapride with non-invasive assessment of myoelectrical activity in the small intestine and caecum of healthy horses after jejunocaecostomy. Six horses underwent celiotomy and jejunocaecostomy, and were treated with mosapride (treated group) at 1.5 mg\\/kg per osos once daily for 5 days after surgery. The other six horses

Kouichi Okamura; Naoki Sasaki; Takuya Kikuchi; Aya Murata; Inhyung Lee; Haruo Yamada; Hisashi Inokuma

2009-01-01

416

Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration  

SciTech Connect

The thermodynamics of hydration is expected to change gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc. We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at a series of different temperatures. Knowing the dependence of the hydration free energy on the temperature and solute size, one can also obtain its enthalpic and entropic contributions as functions of both temperature and solute size. These functions can provide some interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T = 293.15 K to T = 333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data on the hydration of simple molecular solutes. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

Djikaev, Y. S., E-mail: idjikaev@buffalo.edu; Ruckenstein, E. [Department of Chemical and Biological Engineering, SUNY at Buffalo, Buffalo, New York 14260 (United States)] [Department of Chemical and Biological Engineering, SUNY at Buffalo, Buffalo, New York 14260 (United States)

2013-11-14

417

The influence of scalar relativistic effect on the carbon monoxide adsorption onto small gold clusters  

NASA Astrophysics Data System (ADS)

A comparative study between all-electron relativistic (AER) calculation and all-electron (AE) calculation on the carbon monoxide adsorption onto small gold clusters has been performed. Our results reveal that the AunCO cluster obtained by the AER method has shorter Au-C bond-length, longer C-O bond-length, larger binding energy and adsorption energy, higher VIP and VEA, greater charge transfers, higher vibrational frequency of the Au-C mode and lower vibrational frequency of the C-O mode. All these facts suggest that the scalar relativistic effect can strengthen the Au-C bond and weaken the C-O bond, appearing as shorter Au-C bond-length and longer C-O bond-length. It is believed that the scalar relativistic effect is favorable to the CO adsorption onto small gold clusters and the reactivity enhancement of CO molecule. Some further studies focused on the influence of scalar relativistic effect on the adsorption behavior of other small molecules onto gold clusters are necessary in the future.

Kuang, Xiangjun; Wang, Xinqiang; Liu, Gaobin

2012-07-01

418

Effects of teacher-directed versus student-directed instruction on self-management of young children with disabilities.  

PubMed Central

In this study, students worked independently by setting goals, selecting assignments, and recording and evaluating their results after receiving one of two different types of self-management training. During teacher-directed training, the teacher set goals, assigned work, and recorded and evaluated results for students. During student-directed training, students performed those tasks themselves. The results indicated that students engaged in the self-management behaviors more frequently during independent work following student-directed instruction than following teacher-directed instruction.

Mithaug, Deirdre K; Mithaug, Dennis E

2003-01-01

419

EFFECTS OF DIRECTED WRITTEN DISCLOSURE ON GRIEF AND DISTRESS SYMPTOMS AMONG BEREAVED INDIVIDUALS  

PubMed Central

Bereavement-specific written disclosure trials have generally demonstrated null effects, but these studies have not directed the focus of writing. This randomized controlled trial compared directed writing that focused on either sense-making or benefit-finding, both associated with adjustment to loss, to traditional, non-directed emotional disclosure and a control condition. Bereaved undergraduates (n = 68) completed three 20-min writing sessions over 1 week. Intervention effects were found on prolonged grief disorder, depressive, and posttraumatic stress symptoms 3 months postintervention, and the benefit-finding condition appeared particularly efficacious. Physical health improved over time in all treatment groups. Findings suggested that directing written disclosure on topics associated with adjustment to bereavement may be useful for grieving individuals.

LICHTENTHAL, WENDY G.; CRUESS, DEAN G.

2013-01-01

420

Effects of tobacco constituents and psychological stress on the beta-adrenergic regulation of non-small cell lung cancer and pancreatic cancer: implications for intervention  

PubMed Central

This review summarizes current preclinical and clinical evidence in support of the hypothesis that smoking and psychological stress have significant cancer promoting effects on non small cell lung cancer and pancreatic cancer via direct and indirect effects on nicotinic receptor-regulated beta-adrenergic signaling. Evidence is provided that targeted pharmacological interference with the resulting hyperactive cAMP-dependent signaling by beta-blockers or by ?-aminobutyric acid as well as positive psychological influences may be highly effective in preventing and improving clinical outcomes of these cancers, provided that appropriate diagnostic protocols are followed to monitor systemic levels of stress neurotransmitters and cAMP.

Schuller, Hildegard M.

2013-01-01

421

Small amplitude solitons in a warm plasma with smaller and higher order relativistic effects  

SciTech Connect

Solitons have been investigated in a warm plasma through the Korteweg-de Vries (KdV) equation, considering a smaller relativistic effect for {gamma}{approx_equal}O(v{sup 2}/c{sup 2}) and {gamma}{sub e}{approx_equal}O(u{sup 2}/c{sup 2}) and higher relativistic effects for {gamma}{approx_equal}O(v{sup 4}/c{sup 4}) and {gamma}{sub e}{approx_equal}O(u{sup 4/}c{sup 4}). Compressive fast ion-acoustic solitons are observed to exist in the entire range (u{sub 0}-v{sub 0}) subject to a suitable mathematical condition satisfied by the initial streaming velocities u{sub 0},v{sub 0} of the electrons and the ions, respectively, electron to ion mass ratio Q(=m{sub e}/m{sub i}) and ion to electron temperature ratio {sigma}(=T{sub i}/T{sub e}). Further, rarefactive solitons of pretty small amplitudes are observed in the small upper range of |u{sub 0}-v{sub 0}| for higher order relativistic effect which are found to change parabolically. It is essentially important to report in our model of plasma, that the higher order relativistic effect slows down the soliton speed to V{<=}0.10 for all temperature ratios {sigma} for small amplitude waves. On the other hand, the smaller order relativistic effect permits the soliton to exist even at a relatively much higher speed V<0.30. Solitons of high (negligible) amplitudes are found to generate at the smaller (greater) difference of initial streamings (u{sub 0}-v{sub 0}) corresponding to both the relativistic effects.

Kalita, B. C.; Das, R. [Department of Mathematics, Gauhati University, Guwahati-781014, Assam (India); Department of Mathematics, Arya Vidyapeeth College, Guwahati-781016, Assam (India)

2007-07-15

422

The soothing effect of rocking as determined by the direction and frequency of movement  

Microsoft Academic Search

Recent research has revealed that rocking is a potent soother of infant distress, the effectiveness of which is a direct function of frequency and amplitude. The present 2 experiments with a total of 112 2-mo-old infants were conducted because previous studies have not examined the influence of direction per se. In Exp I, Ss were rocked in an up-and-down, side-to-side,

David R. Pederson

1975-01-01

423

Quetiapine has a direct effect on the negative symptoms of schizophrenia.  

PubMed

Second-generation 'atypical' antipsychotics appear to be more effective than first-generation 'typical' antipsychotics in improving negative symptoms in schizophrenia; it is unclear, however, if this greater improvement represents a direct beneficial effect or is mediated indirectly by an antidepressant effect or the absence of extrapyramidal symptoms (EPS). To address this issue with reference to quetiapine ('Seroquel'), data were evaluated from four randomized, controlled clinical studies involving 1106 patients employing a path analysis model. The total effect of quetiapine on negative symptoms was measured using the Scale for Assessment of Negative Symptoms (SANS) total score. Indirect effects on negative symptoms via positive, depressive and EPS were assessed using appropriate instruments. Effect sizes were calculated by path analysis for the difference between treatment groups in change from baseline to endpoint in SANS total score. Analysis confirmed that quetiapine produced a greater overall improvement in negative symptoms than placebo (effect size 1.96); this was explained by a significant direct effect (p = 0.001; 44.2% of total improvement), and a secondary effect of improved positive symptoms (p < 0.001; 47.5% of total improvement), but was not a consequence of changes in depressive symptoms or EPS. Within the constraints of the path analysis methodology, these results indicate that quetiapine has a substantial direct effect on improving the negative symptoms of schizophrenia. PMID:15486960

Tandon, Rajiv

2004-12-01

424

The Effect of Nicorandil on Small Intestinal Ischemia–Reperfusion Injury in a Canine Model  

Microsoft Academic Search

Background  It has been shown that nicorandil, which has both ATP-sensitive K+ (KATP) channel opener-like and nitrate-like properties, has an organ-protective effect in ischemia–reperfusion injury in several\\u000a experimental animal models.\\u000a \\u000a \\u000a \\u000a \\u000a Aims  We evaluate the effectiveness of nicorandil on warm ischemia–reperfusion injury of the small intestine in a canine model.\\u000a \\u000a \\u000a \\u000a Methods  Eighteen beagle dogs were divided into three groups: the control group (n = 6); the

Yujin Suto; Kiyohiro Oshima; Kazuhisa Arakawa; Hiroaki Sato; Hodaka Yamazaki; Koshi Matsumoto; Izumi Takeyoshi

2011-01-01

425

Snow accretion effect on the small antenna used for centimeter-wave satellite communications  

NASA Astrophysics Data System (ADS)

Wakkanai Radio Wave Observatory joined CS propagation experiments at 19.45 GHz in Nov. 1978 and has studied the effect of snow accretion on the parabolic antenna in connection with the three-dimensional accretion pattern, snow density and other meteorological conditions. Several snow protection radomes were devised for the Observatory, and vinyl cover on the antenna was shown to be very effective for one of the radomes. Small attenuations of radio waves less than 1 dB were often observed during winter, especially during a very cold wave. This is thought to be caused by very thick snow clouds in the sky.