Phenotypic plasticity to light and nutrient availability alters functional trait ranking across eight perennial grassland species.

PubMed

Siebenkäs, Alrun; Schumacher, Jens; Roscher, Christiane

2015-03-27

Functional traits are often used as species-specific mean trait values in comparative plant ecology or trait-based predictions of ecosystem processes, assuming that interspecific differences are greater than intraspecific trait variation and that trait-based ranking of species is consistent across environments. Although this assumption is increasingly challenged, there is a lack of knowledge regarding to what degree the extent of intraspecific trait variation in response to varying environmental conditions depends on the considered traits and the characteristics of the studied species to evaluate the consequences for trait-based species ranking. We studied functional traits of eight perennial grassland species classified into different functional groups (forbs vs. grasses) and varying in their inherent growth stature (tall vs. small) in a common garden experiment with different environments crossing three levels of nutrient availability and three levels of light availability over 4 months of treatment applications. Grasses and forbs differed in almost all above- and belowground traits, while trait differences related to growth stature were generally small. The traits showing the strongest responses to resource availability were similarly for grasses and forbs those associated with allocation and resource uptake. The strength of trait variation in response to varying resource availability differed among functional groups (grasses > forbs) and species of varying growth stature (small-statured > tall-statured species) in many aboveground traits, but only to a lower extent in belowground traits. These differential responses altered trait-based species ranking in many aboveground traits, such as specific leaf area, tissue nitrogen and carbon concentrations and above-belowground allocation (leaf area ratio and root : shoot ratio) at varying resource supply, while trait-based species ranking was more consistent in belowground traits. Our study shows that species grouping according to functional traits is valid, but trait-based species ranking depends on environmental conditions, thus limiting the applicability of species-specific mean trait values in ecological studies. Published by Oxford University Press on behalf of the Annals of Botany Company.

Father Involvement, Nurturant Fathering, and Young Adult Psychosocial Functioning: Differences among Adoptive, Adoptive Stepfather, and Nonadoptive Stepfamilies

ERIC Educational Resources Information Center

Schwartz, Seth J.; Finley, Gordon E.

2006-01-01

The present study was conducted to investigate differences in nurturant fathering, father involvement, and young adult psychosocial functioning among small samples of three nontraditional family forms. A total of 168 young-adult university students from three family forms (27 adoptive, 22 adoptive stepfather, 119 nonadoptive stepfather) completed…

Consistent, small effects of treefall disturbances on the composition and diversity of four Amazonian forests.

PubMed

Baker, Timothy R; Vela Díaz, Dilys M; Chama Moscoso, Victor; Navarro, Gilberto; Monteagudo, Abel; Pinto, Ruy; Cangani, Katia; Fyllas, Nikolaos M; Lopez Gonzalez, Gabriela; Laurance, William F; Lewis, Simon L; Lloyd, Jonathan; Ter Steege, Hans; Terborgh, John W; Phillips, Oliver L

2016-03-01

Understanding the resilience of moist tropical forests to treefall disturbance events is important for understanding the mechanisms that underlie species coexistence and for predicting the future composition of these ecosystems. Here, we test whether variation in the functional composition of Amazonian forests determines their resilience to disturbance.We studied the legacy of natural treefall disturbance events in four forests across Amazonia that differ substantially in functional composition. We compared the composition and diversity of all free-standing woody stems 2-10 cm diameter in previously disturbed and undisturbed 20 × 20 m subplots within 55, one-hectare, long-term forest inventory plots.Overall, stem number increased following disturbance, and species and functional composition shifted to favour light-wooded, small-seeded taxa. Alpha-diversity increased, but beta-diversity was unaffected by disturbance, in all four forests.Changes in response to disturbance in both functional composition and alpha-diversity were, however, small (2 - 4% depending on the parameter) and similar among forests. Synthesis . This study demonstrates that variation in the functional composition of Amazonian forests does not lead to large differences in the response of these forests to treefall disturbances, and overall, these events have a minor role in maintaining the diversity of these ecosystems.

The Association of Lung Function, Bronchial Hyperresponsiveness, and Exhaled Nitric Oxide Differs Between Atopic and Non-atopic Asthma in Children

PubMed Central

Shim, Eunhee; Lee, Eun; Yang, Song-I; Jung, Young-Ho; Park, Geun Mi; Kim, Hyung Young; Seo, Ju-Hee

2015-01-01

Purpose Although many previous studies have attempted to identify differences between atopic asthma (AA) and non-atopic asthma (NAA), they have mainly focused on the difference of each variable of lung function and airway inflammation. The aim of this study was to evaluate relationships between lung function, bronchial hyperresponsiveness (BHR), and the exhaled nitric oxide (eNO) levels in children with AA and NAA. Methods One hundred and thirty six asthmatic children aged 5-15 years and 40 normal controls were recruited. Asthma cases were classified as AA (n=100) or NAA (n=36) from skin prick test results. Lung function, BHR to methacholine and adenosine-5'-monophosphate (AMP), eNO, blood eosinophils, and serum total IgE were measured. Results The AA and NAA cases shared common features including a reduced small airway function and increased BHR to methacholine. However, children with AA showed higher BHR to AMP and eNO levels than those with NAA. When the relationships among these variables in the AA and NAA cases were evaluated, the AA group showed significant relationships between lung function, BHR to AMP or methacholine and eNO levels. However, the children in the NAA group showed an association between small airway function and BHR to methacholine only. Conclusions These findings suggest that the pathogenesis of NAA may differ from that of AA during childhood in terms of the relationship between lung function, airway inflammation and BHR. PMID:25749776

Comparisons between Murine Polyomavirus and Simian Virus 40 Show Significant Differences in Small T Antigen Function ▿

PubMed Central

Andrabi, Shaida; Hwang, Justin H.; Choe, Jennifer Kean; Roberts, Thomas M.; Schaffhausen, Brian S.

2011-01-01

Although members of a virus family produce similar gene products, those products may have quite different functions. Simian virus 40 (SV40) large T antigen (LT), for example, targets p53 directly, but murine polyomavirus LT does not. SV40 small T antigen (SVST) has received considerable attention because of its ability to contribute to transformation of human cells. Here, we show that there are major differences between SVST and polyomavirus small T antigen (POLST) in their effects on differentiation, transformation, and cell survival. Both SVST and POLST induce cell cycle progression. However, POLST also inhibits differentiation of 3T3-L1 preadipocytes and C2C12 myoblasts. Additionally, POLST induces apoptosis of mouse embryo fibroblasts. SVST reduces the proapoptotic transcriptional activity of FOXO1 through phosphorylation. On the other hand, SVST complements large T antigen and Ras for the transformation of human mammary epithelial cells (HMECs), but POLST does not. Mechanistically, the differences between SVST and POLST may lie in utilization of protein phosphatase 2A (PP2A). POLST binds both Aα and Aβ scaffolding subunits of PP2A while SVST binds only Aα. Knockdown of Aβ could mimic POLST-induced apoptosis. The two small T antigens can target different proteins for dephosphorylation. POLST binds and dephosphorylates substrates, such as lipins, that SVST does not. PMID:21835797

Small-worldness characteristics and its gender relation in specific hemispheric networks.

PubMed

Miraglia, F; Vecchio, F; Bramanti, P; Rossini, P M

2015-12-03

Aim of this study was to verify whether the topological organization of human brain functional networks is different for males and females in resting state EEGs. Undirected and weighted brain networks were computed by eLORETA lagged linear connectivity in 130 subjects (59 males and 71 females) within each hemisphere and in four resting state networks (Attentional Network (AN), Frontal Network (FN), Sensorimotor Network (SN), Default Mode Network (DMN)). We found that small-world (SW) architecture in the left hemisphere Frontal network presented differences in both delta and alpha band, in particular lower values in delta and higher in alpha 2 in males respect to females while in the right hemisphere differences were found in lower values of SW in males respect to females in gamma Attentional, delta Sensorimotor and delta and gamma DMNs. Gender small-worldness differences in some of resting state networks indicated that there are specific brain differences in the EEG rhythms when the brain is in the resting-state condition. These specific regions could be considered related to the functions of behavior and cognition and should be taken into account both for research on healthy and brain diseased subjects. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Quantifying stock-price response to demand fluctuations

NASA Astrophysics Data System (ADS)

Plerou, Vasiliki; Gopikrishnan, Parameswaran; Gabaix, Xavier; Stanley, H. Eugene

2002-08-01

We empirically address the question of how stock prices respond to changes in demand. We quantify the relations between price change G over a time interval Δt and two different measures of demand fluctuations: (a) Φ, defined as the difference between the number of buyer-initiated and seller-initiated trades, and (b) Ω, defined as the difference in number of shares traded in buyer- and seller-initiated trades. We find that the conditional expectation functions of price change for a given Φ or Ω, Φ and Ω (``market impact function''), display concave functional forms that seem universal for all stocks. For small Ω, we find a power-law behavior Ω~Ω1/8 with δ depending on Δt (δ~3 for Δt=5 min, δ~3/2 for Δt=15 min and δ~1 for large Δt). We find that large price fluctuations occur when demand is very small-a fact that is reminiscent of large fluctuations that occur at critical points in spin systems, where the divergent nature of the response function leads to large fluctuations.

Small RNA profiling in two Brassica napus cultivars identifies microRNAs with oil production- and development-correlated expression and new small RNA classes.

PubMed

Zhao, Ying-Tao; Wang, Meng; Fu, San-Xiong; Yang, Wei-Cai; Qi, Cun-Kou; Wang, Xiu-Jie

2012-02-01

MicroRNAs (miRNAs) and small interfering RNAs are important regulators of plant development and seed formation, yet their population and abundance in the oil crop Brassica napus are still not well understood, especially at different developmental stages and among cultivars with varied seed oil contents. Here, we systematically analyzed the small RNA expression profiles of Brassica napus seeds at early embryonic developmental stages in high-oil-content and low-oil-content B. napus cultivars, both cultured in two environments. A total of 50 conserved miRNAs and 9 new miRNAs were identified, together with some new miRNA targets. Expression analysis revealed some miRNAs with varied expression levels in different seed oil content cultivars or at different embryonic developmental stages. A large number of 23-nucleotide small RNAs with specific nucleotide composition preferences were also identified, which may present new classes of functional small RNAs.

Application of finite element approach to transonic flow problems

NASA Technical Reports Server (NTRS)

Hafez, M. M.; Murman, E. M.; Wellford, L. C., Jr.

1976-01-01

A variational finite element model for transonic small disturbance calculations is described. Different strategy is adopted in subsonic and supersonic regions, and blending elements are introduced between different regions. In the supersonic region, no upstream effect is allowed. If rectangular elements with linear shape functions are used, the model is similar to Murman's finite difference operators. Higher order shape functions, nonrectangular elements, and discontinuous approximation of shock waves are also discussed.

No Evidence for a Trade-Off between Reproductive Investment and Immunity in a Rodent

PubMed Central

Xu, Yan-Chao; Yang, Deng-Bao; Wang, De-Hua

2012-01-01

Life history theory assumes there are trade-offs between competing functions such as reproduction and immunity. Although well studied in birds, studies of the trade-offs between reproduction and immunity in small mammals are scarce. Here we examined whether reduced immunity is a consequence of reproductive effort in lactating Brandt's voles (Lasiopodomys brandtii). Specifically, we tested the effects of lactation on immune function (Experiment I). The results showed that food intake and resting metabolic rate (RMR) were higher in lactating voles (6≤ litter size ≤8) than that in non-reproductive voles. Contrary to our expectation, lactating voles also had higher levels of serum total Immunoglobulin G (IgG) and anti-keyhole limpet hemocyanin (KLH) IgG and no change in phytohemagglutinin (PHA) response and anti-KLH Immunoglobulin M (IgM) compared with non-reproductive voles, suggesting improved rather than reduced immune function. To further test the effect of differences in reproductive investment on immunity, we compared the responses between natural large (n≥8) and small litter size (n≤6) (Experiment II) and manipulated large (11–13) and small litter size (2–3) (Experiment III). During peak lactation, acquired immunity (PHA response, anti-KLH IgG and anti-KLH IgM) was not significantly different between voles raising large or small litters in both experiments, despite the measured difference in reproductive investment (greater litter size, litter mass, RMR and food intake in the voles raising larger litters). Total IgG was higher in voles with natural large litter size than those with natural small litter size, but decreased in the enlarged litter size group compared with control and reduced group. Our results showed that immune function is not suppressed to compensate the high energy demands during lactation in Brandt's voles and contrasting the situation in birds, is unlikely to be an important aspect mediating the trade-off between reproduction and survival. PMID:22649512

On the Reliability of Source Time Functions Estimated Using Empirical Green's Function Methods

NASA Astrophysics Data System (ADS)

Gallegos, A. C.; Xie, J.; Suarez Salas, L.

2017-12-01

The Empirical Green's Function (EGF) method (Hartzell, 1978) has been widely used to extract source time functions (STFs). In this method, seismograms generated by collocated events with different magnitudes are deconvolved. Under a fundamental assumption that the STF of the small event is a delta function, the deconvolved Relative Source Time Function (RSTF) yields the large event's STF. While this assumption can be empirically justified by examination of differences in event size and frequency content of the seismograms, there can be a lack of rigorous justification of the assumption. In practice, a small event might have a finite duration when the RSTF is retrieved and interpreted as the large event STF with a bias. In this study, we rigorously analyze this bias using synthetic waveforms generated by convolving a realistic Green's function waveform with pairs of finite-duration triangular or parabolic STFs. The RSTFs are found using a time-domain based matrix deconvolution. We find when the STFs of smaller events are finite, the RSTFs are a series of narrow non-physical spikes. Interpreting these RSTFs as a series of high-frequency source radiations would be very misleading. The only reliable and unambiguous information we can retrieve from these RSTFs is the difference in durations and the moment ratio of the two STFs. We can apply a Tikhonov smoothing to obtain a single-pulse RSTF, but its duration is dependent on the choice of weighting, which may be subjective. We then test the Multi-Channel Deconvolution (MCD) method (Plourde & Bostock, 2017) which assumes that both STFs have finite durations to be solved for. A concern about the MCD method is that the number of unknown parameters is larger, which would tend to make the problem rank-deficient. Because the kernel matrix is dependent on the STFs to be solved for under a positivity constraint, we can only estimate the rank-deficiency with a semi-empirical approach. Based on the results so far, we find that the rank-deficiency makes it improbable to solve for both STFs. To solve for the larger STF we need to assume the shape of the small STF to be known a priori. Thus, the reliability of the estimated large STF depends on the difference between the assumed and true shapes of the small STF. We will show how the reliability varies with realistic scenarios.

A mimetic finite difference method for the Stokes problem with elected edge bubbles

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

Lipnikov, K; Berirao, L

2009-01-01

A new mimetic finite difference method for the Stokes problem is proposed and analyzed. The unstable P{sub 1}-P{sub 0} discretization is stabilized by adding a small number of bubble functions to selected mesh edges. A simple strategy for selecting such edges is proposed and verified with numerical experiments. The discretizations schemes for Stokes and Navier-Stokes equations must satisfy the celebrated inf-sup (or the LBB) stability condition. The stability condition implies a balance between discrete spaces for velocity and pressure. In finite elements, this balance is frequently achieved by adding bubble functions to the velocity space. The goal of this articlemore » is to show that the stabilizing edge bubble functions can be added only to a small set of mesh edges. This results in a smaller algebraic system and potentially in a faster calculations. We employ the mimetic finite difference (MFD) discretization technique that works for general polyhedral meshes and can accomodate non-uniform distribution of stabilizing bubbles.« less

Functional brain networks in Alzheimer's disease: EEG analysis based on limited penetrable visibility graph and phase space method

NASA Astrophysics Data System (ADS)

Wang, Jiang; Yang, Chen; Wang, Ruofan; Yu, Haitao; Cao, Yibin; Liu, Jing

2016-10-01

In this paper, EEG series are applied to construct functional connections with the correlation between different regions in order to investigate the nonlinear characteristic and the cognitive function of the brain with Alzheimer's disease (AD). First, limited penetrable visibility graph (LPVG) and phase space method map single EEG series into networks, and investigate the underlying chaotic system dynamics of AD brain. Topological properties of the networks are extracted, such as average path length and clustering coefficient. It is found that the network topology of AD in several local brain regions are different from that of the control group with no statistically significant difference existing all over the brain. Furthermore, in order to detect the abnormality of AD brain as a whole, functional connections among different brain regions are reconstructed based on similarity of clustering coefficient sequence (CCSS) of EEG series in the four frequency bands (delta, theta, alpha, and beta), which exhibit obvious small-world properties. Graph analysis demonstrates that for both methodologies, the functional connections between regions of AD brain decrease, particularly in the alpha frequency band. AD causes the graph index complexity of the functional network decreased, the small-world properties weakened, and the vulnerability increased. The obtained results show that the brain functional network constructed by LPVG and phase space method might be more effective to distinguish AD from the normal control than the analysis of single series, which is helpful for revealing the underlying pathological mechanism of the disease.

Can Neuroimaging Markers of Vascular Pathology Explain Cognitive Performance in Adults with Sickle Cell Anemia? A Review of the Literature

PubMed Central

Jorgensen, Dana R.; Rosano, Caterina; Novelli, Enrico M.

2017-01-01

Adults with homozygous sickle cell anemia have, on average, lower cognitive function than unaffected controls. The mechanisms underlying cognitive deterioration in this population are poorly understood, but cerebral small vessel disease (CSVD) is likely to be implicated. We conducted a systematic review using the Prisma Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of articles that included both measures of cognitive function and magnetic resonance imaging (MRI) neuroimaging markers of small vessel disease. While all five studies identified small vessel disease by MRI, only two of them found a significant relationship between structural changes and cognitive performance. Differences in methodologies and small sample sizes likely accounted for the discrepancies between the studies. We conclude that while MRI is a valuable tool to identify markers of CSVD in this population, larger studies are needed to definitely establish a link between MRI-detectable abnormalities and cognitive function in sickle cell anemia. PMID:27689914

Inhibition of amyloid oligomerization into different supramolecular architectures by small molecules: mechanistic insights and design rules.

PubMed

Brahmachari, Sayanti; Paul, Ashim; Segal, Daniel; Gazit, Ehud

2017-05-01

Protein misfolding and aggregation have been associated with several human disorders, including Alzheimer's, Parkinson's and Huntington's diseases, as well as senile systemic amyloidosis and Type II diabetes. However, there is no current disease-modifying therapy available for the treatment of these disorders. In spite of extensive academic, pharmaceutical, medicinal and clinical research, a complete mechanistic model for this family of diseases is still lacking. In this review, we primarily discuss the different types of small molecular entities which have been used for the inhibition of the aggregation process of different amyloidogenic proteins under diseased conditions. These include small peptides, polyphenols, inositols, quinones and their derivatives, and metal chelator molecules. In recent years, these groups of molecules have been extensively studied using in vitro, in vivo and computational models to understand their mechanism of action and common structural features underlying the process of inhibition. A salient feature found to be instrumental in the process of inhibition is the balance between the aromatic unit that functions as the amyloid recognition unit and the hydrophilic amyloid breaker unit. The establishment of structure-function relationship for amyloid-modifying therapies by the various functional entities should serve as an important step toward the development of efficient therapeutics.

Effects of species' similarity and dominance on the functional and phylogenetic structure of a plant meta-community.

PubMed

Chalmandrier, L; Münkemüller, T; Lavergne, S; Thuiller, W

2015-01-01

Different assembly processes drive the spatial structure of meta-communities (beta-diversity). Recently, functional and phylogenetic diversities have been suggested as indicators of these assembly processes. Assuming that diversity is a good proxy for niche overlap, high beta-diversity along environmental gradients should be the result of environmental filtering while low beta-diversity should stem from competitive interactions. So far, studies trying to disentangle the relative importance of these assembly processes have provided mixed results. One reason for this may be that these studies often rely on a single measure of diversity and thus implicitly make a choice on how they account for species relative abundances and how species similarities are captured by functional traits or phylogeny. Here, we tested the effect of gradually scaling the importance of dominance (the weight given to dominant vs. rare species) and species similarity (the weight given to small vs. large similarities) on resulting beta-diversity patterns of an alpine plant meta-community. To this end, we combined recent extensions of the Hill numbers framework with Pagel's phylogenetic tree transformation approach. We included functional (based on the leaf-height-seed spectrum) and phylogenetic facets of beta-diversity in our analysis and explicitly accounted for effects of environmental and spatial covariates. We found that functional beta-diversity, was high when the same weight was given to dominant vs. rare species and to large vs. small species' similarities. In contrast, phylogenetic beta-diversity was low when greater weight was given to dominant species and small species' similarities. Those results suggested that different environments along the gradients filtered different species according to their functional traits, while, the same competitive lineages dominated communities across the gradients. Our results highlight that functional vs. phylogenetic facets, presence-absence vs. abundance structure and different weights of species' dissimilarity provide complementary and important information on the drivers of meta-community structure. By utilizing the full extent of information provided by the flexible frameworks of Hill numbers and Pagel's tree transformation, we propose a new approach to disentangle the patterns resulting from different assembly processes.

Comparison of Students' Understanding of Functions in Classes Following English and Israeli National Curricula

ERIC Educational Resources Information Center

Watson, Anne; Ayalon, Michal; Lerman, Stephen

2018-01-01

This paper arises from a study of how concepts related to understanding functions develop for students across the years of secondary/high school, using small samples from two different curricula systems: England and Israel. We used a survey consisting of function tasks developed in collaboration with teachers from both curriculum systems. We…

Gastrointestinal Nutrient Infusion Site and Eating Behavior: Evidence for A Proximal to Distal Gradient within the Small Intestine?

PubMed

Alleleyn, Annick M E; van Avesaat, Mark; Troost, Freddy J; Masclee, Adrian A M

2016-02-26

The rapidly increasing prevalence of overweight and obesity demands new strategies focusing on prevention and treatment of this significant health care problem. In the search for new and effective therapeutic modalities for overweight subjects, the gastrointestinal (GI) tract is increasingly considered as an attractive target for medical and food-based strategies. The entry of nutrients into the small intestine activates so-called intestinal "brakes", negative feedback mechanisms that influence not only functions of more proximal parts of the GI tract but also satiety and food intake. Recent evidence suggests that all three macronutrients (protein, fat, and carbohydrates) are able to activate the intestinal brake, although to a different extent and by different mechanisms of action. This review provides a detailed overview of the current evidence for intestinal brake activation of the three macronutrients and their effects on GI function, satiety, and food intake. In addition, these effects appear to depend on region and length of infusion in the small intestine. A recommendation for a therapeutic approach is provided, based on the observed differences between intestinal brake activation.

Screening small-molecule compound microarrays for protein ligands without fluorescence labeling with a high-throughput scanning microscope.

PubMed

Fei, Yiyan; Landry, James P; Sun, Yungshin; Zhu, Xiangdong; Wang, Xiaobing; Luo, Juntao; Wu, Chun-Yi; Lam, Kit S

2010-01-01

We describe a high-throughput scanning optical microscope for detecting small-molecule compound microarrays on functionalized glass slides. It is based on measurements of oblique-incidence reflectivity difference and employs a combination of a y-scan galvometer mirror and an x-scan translation stage with an effective field of view of 2 cm x 4 cm. Such a field of view can accommodate a printed small-molecule compound microarray with as many as 10,000 to 20,000 targets. The scanning microscope is capable of measuring kinetics as well as endpoints of protein-ligand reactions simultaneously. We present the experimental results on solution-phase protein reactions with small-molecule compound microarrays synthesized from one-bead, one-compound combinatorial chemistry and immobilized on a streptavidin-functionalized glass slide.

Screening small-molecule compound microarrays for protein ligands without fluorescence labeling with a high-throughput scanning microscope

PubMed Central

Fei, Yiyan; Landry, James P.; Sun, Yungshin; Zhu, Xiangdong; Wang, Xiaobing; Luo, Juntao; Wu, Chun-Yi; Lam, Kit S.

2010-01-01

We describe a high-throughput scanning optical microscope for detecting small-molecule compound microarrays on functionalized glass slides. It is based on measurements of oblique-incidence reflectivity difference and employs a combination of a y-scan galvometer mirror and an x-scan translation stage with an effective field of view of 2 cm×4 cm. Such a field of view can accommodate a printed small-molecule compound microarray with as many as 10,000 to 20,000 targets. The scanning microscope is capable of measuring kinetics as well as endpoints of protein-ligand reactions simultaneously. We present the experimental results on solution-phase protein reactions with small-molecule compound microarrays synthesized from one-bead, one-compound combinatorial chemistry and immobilized on a streptavidin-functionalized glass slide. PMID:20210464

Diffusion of test particles in stochastic magnetic fields for small Kubo numbers.

PubMed

Neuer, Marcus; Spatschek, Karl H

2006-02-01

Motion of charged particles in a collisional plasma with stochastic magnetic field lines is investigated on the basis of the so-called A-Langevin equation. Compared to the previously used A-Langevin model, here finite Larmor radius effects are taken into account. The A-Langevin equation is solved under the assumption that the Lagrangian correlation function for the magnetic field fluctuations is related to the Eulerian correlation function (in Gaussian form) via the Corrsin approximation. The latter is justified for small Kubo numbers. The velocity correlation function, being averaged with respect to the stochastic variables including collisions, leads to an implicit differential equation for the mean square displacement. From the latter, different transport regimes, including the well-known Rechester-Rosenbluth diffusion coefficient, are derived. Finite Larmor radius contributions show a decrease of the diffusion coefficient compared to the guiding center limit. The case of small (or vanishing) mean fields is also discussed.

Analysis of drift correction in different simulated weighing schemes

NASA Astrophysics Data System (ADS)

Beatrici, A.; Rebelo, A.; Quintão, D.; Cacais, F. L.; Loayza, V. M.

2015-10-01

In the calibration of high accuracy mass standards some weighing schemes are used to reduce or eliminate the zero drift effects in mass comparators. There are different sources for the drift and different methods for its treatment. By using numerical methods, drift functions were simulated and a random term was included in each function. The comparison between the results obtained from ABABAB and ABBA weighing series was carried out. The results show a better efficacy of ABABAB method for drift with smooth variation and small randomness.

Minimum important differences for the patient-specific functional scale, 4 region-specific outcome measures, and the numeric pain rating scale.

PubMed

Abbott, J Haxby; Schmitt, John

2014-08-01

Multicenter, prospective, longitudinal cohort study. To investigate the minimum important difference (MID) of the Patient-Specific Functional Scale (PSFS), 4 region-specific outcome measures, and the numeric pain rating scale (NPRS) across 3 levels of patient-perceived global rating of change in a clinical setting. The MID varies depending on the external anchor defining patient-perceived "importance." The MID for the PSFS has not been established across all body regions. One thousand seven hundred eight consecutive patients with musculoskeletal disorders were recruited from 5 physical therapy clinics. The PSFS, NPRS, and 4 region-specific outcome measures-the Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale-were assessed at the initial and final physical therapy visits. Global rating of change was assessed at the final visit. MID was calculated for the PSFS and NPRS (overall and for each body region), and for each region-specific outcome measure, across 3 levels of change defined by the global rating of change (small, medium, large change) using receiver operating characteristic curve methodology. The MID for the PSFS (on a scale from 0 to 10) ranged from 1.3 (small change) to 2.3 (medium change) to 2.7 (large change), and was relatively stable across body regions. MIDs for the NPRS (-1.5 to -3.5), Oswestry Disability Index (-12), Neck Disability Index (-14), Upper Extremity Functional Index (6 to 11), and Lower Extremity Functional Scale (9 to 16) are also reported. We reported the MID for small, medium, and large patient-perceived change on the PSFS, NPRS, Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale for use in clinical practice and research.

Diversity of terrestrial mammal seed dispersers along a lowland Amazon forest regrowth gradient

PubMed Central

Arévalo-Sandi, Alexander; Bobrowiec, Paulo Estefano D.; Rodriguez Chuma, Victor Juan Ulises

2018-01-01

There is increasing interest in the restoration/regeneration of degraded tropical habitats yet the potential role of natural regenerators remains unclear. We test the hypothesis that the richness and functional diversity of terrestrial mammals differs between forest regrowth stages. We quantified the richness and functional diversity of eight terrestrial mammal seed-disperser species across a forest regrowth gradient in the eastern Brazilian Amazon. We installed camera-traps in 15 sites within small-holder properties with forest regrowth stage classified into three groups, with five sites each of: late second-regrowth forest, early second-regrowth forest and abandoned pasture. Species richness and functional dispersion from the regrowth sites were compared with 15 paired forest control sites. Multi model selection showed that regrowth class was more important for explaining patterns in richness and functional diversity than other variables from three non-mutually exclusive hypotheses: hunting (distance to house, distance to river, distance to town, small holder residence), land cover (% forest cover within 50 meters, 1 kilometer and 5 kilometers) and land use (regrowth class, time since last use). Differences in functional diversity were most strongly explained by a loss of body mass. We found that diversity in regrowth sites could be similar to control sites even in some early-second regrowth areas. This finding suggests that when surrounded by large intact forest areas the richness and functional diversity close to human small-holdings can return to pre-degradation values. Yet we also found a significant reduction in richness and functional diversity in more intensely degraded pasture sites. This reduction in richness and functional diversity may limit the potential for regeneration and increase costs for ecological regeneration and restoration actions around more intense regrowth areas. PMID:29547648

Diversity of terrestrial mammal seed dispersers along a lowland Amazon forest regrowth gradient.

PubMed

Arévalo-Sandi, Alexander; Bobrowiec, Paulo Estefano D; Rodriguez Chuma, Victor Juan Ulises; Norris, Darren

2018-01-01

There is increasing interest in the restoration/regeneration of degraded tropical habitats yet the potential role of natural regenerators remains unclear. We test the hypothesis that the richness and functional diversity of terrestrial mammals differs between forest regrowth stages. We quantified the richness and functional diversity of eight terrestrial mammal seed-disperser species across a forest regrowth gradient in the eastern Brazilian Amazon. We installed camera-traps in 15 sites within small-holder properties with forest regrowth stage classified into three groups, with five sites each of: late second-regrowth forest, early second-regrowth forest and abandoned pasture. Species richness and functional dispersion from the regrowth sites were compared with 15 paired forest control sites. Multi model selection showed that regrowth class was more important for explaining patterns in richness and functional diversity than other variables from three non-mutually exclusive hypotheses: hunting (distance to house, distance to river, distance to town, small holder residence), land cover (% forest cover within 50 meters, 1 kilometer and 5 kilometers) and land use (regrowth class, time since last use). Differences in functional diversity were most strongly explained by a loss of body mass. We found that diversity in regrowth sites could be similar to control sites even in some early-second regrowth areas. This finding suggests that when surrounded by large intact forest areas the richness and functional diversity close to human small-holdings can return to pre-degradation values. Yet we also found a significant reduction in richness and functional diversity in more intensely degraded pasture sites. This reduction in richness and functional diversity may limit the potential for regeneration and increase costs for ecological regeneration and restoration actions around more intense regrowth areas.

LH pulses and the corpus luteum: the luteal phase deficiency LPD).

PubMed

Wuttke, W; Pitzel, L; Seidlová-Wuttke, D; Hinney, B

2001-01-01

The proper function of the GnRH pulse generator in the hypothalamus is essential for normal ovarian function, hence also for proper function of the corpus luteum. During the luteal phase LH pulses stimulate progesterone release, which is essential for normal endometrial transformation. Approximately one-half of all luteal phase deficiencies (LPD) are due to improper function of the GnRH pulse generator. Obviously, following ovulation the increased serum progesterone levels oversuppress the GnRH pulse generator, resulting in too few LH pulses and therefore improper luteal function. Also, latent hyperprolactinemia may lead to an LPD which can be effectively treated with plant extracts containing dopaminergic (prolactin-suppressing) compounds. Our increasing knowledge of auto- and paracrine mechanisms between nonsteroidogenic and steroidogenic cells now allow subclassification of LPDs of ovarian origin. The so-called small luteal cells are LH-responsive. If they develop improperly the regularly occurring LH pulses are unable to stimulate progesterone secretion from the small luteal cells, which results in what we call the small luteal cell defect. In addition, there is also evidence that the large luteal cells may function improperly. Hence, basal progesterone release is too low while LH-stimulated progesterone release from the small luteal cells appears to be intact. This subclassification of luteal phase deficiency results in the suggestion of different treatments. In cases where the corpus luteum is LH-responsive, such as the hypothalamic corpus luteum insufficiency and the large luteal cell defect, HCG treatment or pulsatile treatment with GnRH is advisable. In the case of LH/hCG-unresponsive small luteal cell defect a progesterone substitution is suggested.

Uncertainty plus Prior Equals Rational Bias: An Intuitive Bayesian Probability Weighting Function

ERIC Educational Resources Information Center

Fennell, John; Baddeley, Roland

2012-01-01

Empirical research has shown that when making choices based on probabilistic options, people behave as if they overestimate small probabilities, underestimate large probabilities, and treat positive and negative outcomes differently. These distortions have been modeled using a nonlinear probability weighting function, which is found in several…

Functional Connectivity Magnetic Resonance Imaging Classification of Autism

ERIC Educational Resources Information Center

Anderson, Jeffrey S.; Nielsen, Jared A.; Froehlich, Alyson L.; DuBray, Molly B.; Druzgal, T. Jason; Cariello, Annahir N.; Cooperrider, Jason R.; Zielinski, Brandon A.; Ravichandran, Caitlin; Fletcher, P. Thomas; Alexander, Andrew L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.

2011-01-01

Group differences in resting state functional magnetic resonance imaging connectivity between individuals with autism and typically developing controls have been widely replicated for a small number of discrete brain regions, yet the whole-brain distribution of connectivity abnormalities in autism is not well characterized. It is also unclear…

Adult primary angiitis of the central nervous system: isolated small-vessel vasculitis represents distinct disease pattern.

PubMed

de Boysson, Hubert; Boulouis, Grégoire; Aouba, Achille; Bienvenu, Boris; Guillevin, Loïc; Zuber, Mathieu; Touzé, Emmanuel; Naggara, Olivier; Pagnoux, Christian

2017-03-01

We aimed to identify whether presentations and outcomes in adult patients with isolated small-vessel primary angiitis of the CNS (PACNS) would differ from other patients with large/medium-vessel involvement. In the French PACNS cohort, we compared the characteristics, treatments and outcomes of patients with isolated small-vessel disease (normal CT, MR and/or conventional angiograms, brain biopsy positive for vasculitis) with other patients who had large/medium-vessel involvement (vessel abnormalities on CT, MR or conventional angiograms). A good functional outcome was defined as a modified Rankin scale ⩽2 at last follow-up, regardless of the occurrence of relapse. Among the 102 patients in the cohort, 26 (25%) had isolated small-vessel PACNS, whereas the 76 others demonstrated large/medium-vessel involvement. Patients with isolated small-vessel PACNS had more seizures (P < 0.0001), cognitive (P = 0.02) or consciousness impairment (P = 0.03) and more dyskinesias (P = 0.002) but less focal deficits (P = 0.0002) than other PACNS patients. They also had more abnormal cerebrospinal fluid analysis (P = 0.008) and gadolinium enhancements on MRI (P = 0.001) but less frequent acute ischaemic lesions (P < 0.0001) than patients with large/medium-vessel involvement. Treatments and modified Rankin scale at last follow-up did not differ between groups. Thirty-two (31%) patients relapsed; 14 (54%) with isolated small-vessel PACNS vs 18 (24%) with large/medium-vessel involvement (P = 0.004). Eight patients died, with no difference between the groups (P = 0.97). In our cohort, adult patients with isolated small-vessel PACNS presented some distinct disease features and relapsed more often than other PACNS patients who had large/medium-vessel involvement. Functional outcomes and mortality did not differ. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Impaired small fiber conduction in patients with Fabry disease: a neurophysiological case–control study

PubMed Central

2013-01-01

Background Fabry disease is an inborn lysosomal storage disorder which is associated with small fiber neuropathy. We set out to investigate small fiber conduction in Fabry patients using pain-related evoked potentials (PREP). Methods In this case–control study we prospectively studied 76 consecutive Fabry patients for electrical small fiber conduction in correlation with small fiber function and morphology. Data were compared with healthy controls using non-parametric statistical tests. All patients underwent neurological examination and were investigated with pain and depression questionnaires. Small fiber function (quantitative sensory testing, QST), morphology (skin punch biopsy), and electrical conduction (PREP) were assessed and correlated. Patients were stratified for gender and disease severity as reflected by renal function. Results All Fabry patients (31 men, 45 women) had small fiber neuropathy. Men with Fabry disease showed impaired cold (p < 0.01) and warm perception (p < 0.05), while women did not differ from controls. Intraepidermal nerve fiber density (IENFD) was reduced at the lower leg (p < 0.001) and the back (p < 0.05) mainly of men with impaired renal function. When investigating A-delta fiber conduction with PREP, men but not women with Fabry disease had lower amplitudes upon stimulation at face (p < 0.01), hands (p < 0.05), and feet (p < 0.01) compared to controls. PREP amplitudes further decreased with advance in disease severity. PREP amplitudes and warm (p < 0.05) and cold detection thresholds (p < 0.01) at the feet correlated positively in male patients. Conclusion Small fiber conduction is impaired in men with Fabry disease and worsens with advanced disease severity. PREP are well-suited to measure A-delta fiber conduction. PMID:23705943

Simulation studies for surfaces and materials strength

NASA Technical Reports Server (NTRS)

Halicioglu, Timur

1987-01-01

A realistic potential energy function comprising angle dependent terms was employed to describe the potential surface of the N+O2 system. The potential energy parameters were obtained from high level ab-initio results using a nonlinear fitting procedure. It was shown that the potential function is able to reproduce a large number of points on the potential surface with a small rms deviation. A literature survey was conducted to analyze exclusively the status of current small cluster research. This survey turned out to be quite useful in understanding and finding out the existing relationship between theoretical as well as experimental investigative techniques employed by different researchers. Additionally, the importance of the role played by computer simulation in small cluster research, was documented.

Functional organization of intrinsic connectivity networks in Chinese-chess experts.

PubMed

Duan, Xujun; Long, Zhiliang; Chen, Huafu; Liang, Dongmei; Qiu, Lihua; Huang, Xiaoqi; Liu, Timon Cheng-Yi; Gong, Qiyong

2014-04-16

The functional architecture of the human brain has been extensively described in terms of functional connectivity networks, detected from the low-frequency coherent neuronal fluctuations during a resting state condition. Accumulating evidence suggests that the overall organization of functional connectivity networks is associated with individual differences in cognitive performance and prior experience. Such an association raises the question of how cognitive expertise exerts an influence on the topological properties of large-scale functional networks. To address this question, we examined the overall organization of brain functional networks in 20 grandmaster and master level Chinese-chess players (GM/M) and twenty novice players, by means of resting-state functional connectivity and graph theoretical analyses. We found that, relative to novices, functional connectivity was increased in GM/Ms between basal ganglia, thalamus, hippocampus, and several parietal and temporal areas, suggesting the influence of cognitive expertise on intrinsic connectivity networks associated with learning and memory. Furthermore, we observed economical small-world topology in the whole-brain functional connectivity networks in both groups, but GM/Ms exhibited significantly increased values of normalized clustering coefficient which resulted in increased small-world topology. These findings suggest an association between the functional organization of brain networks and individual differences in cognitive expertise, which might provide further evidence of the mechanisms underlying expert behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

Papillomavirus E7 Oncoproteins Share Functions with Polyomavirus Small T Antigens

PubMed Central

White, Elizabeth A.; Kramer, Rebecca E.; Hwang, Justin H.; Pores Fernando, Arun T.; Naetar, Nana; Hahn, William C.; Roberts, Thomas M.; Schaffhausen, Brian S.; Livingston, David M.

2014-01-01

ABSTRACT Many of the small DNA tumor viruses encode transforming proteins that function by targeting critical cellular pathways involved in cell proliferation and survival. In this study, we have examined whether some of the functions of the polyomavirus small T antigens (ST) are shared by the E6 and E7 oncoproteins of two oncogenic papillomaviruses. Using three different assays, we have found that E7 can provide some simian virus 40 (SV40) or murine polyomavirus (PyV) ST functions. Both human papillomavirus 16 (HPV16) and bovine papillomavirus (BPV1) E7 proteins are capable of partially substituting for SV40 ST in a transformation assay that also includes SV40 large T antigen, the catalytic subunit of cellular telomerase, and oncogenic Ras. Like SV40 ST, HPV16 E7 has the ability to override a quiescence block induced by mitogen deprivation. Like PyV ST, it also has the ability to inhibit myoblast differentiation. At least two of these activities are dependent upon the interaction of HPV16 E7 with retinoblastoma protein family members. For small T antigens, interaction with PP2A is needed for each of these functions. Even though there is no strong evidence that E6 or E7 share the ability of small T to interact with PP2A, E7 provides these functions related to cellular transformation. IMPORTANCE DNA tumor viruses have provided major insights into how cancers develop. Some viruses, like the human papillomaviruses, can cause cancer directly. Both the papillomaviruses and the polyomaviruses have served as tools for understanding pathways that are often perturbed in cancer. Here, we have compared the functions of transforming proteins from several DNA tumor viruses, including two papillomaviruses and two polyomaviruses. We tested the papillomavirus E6 and E7 oncoproteins in three functional assays and found that E7 can provide some or all of the functions of the SV40 small T antigen, another well-characterized oncoprotein, in two of these assays. In a third assay, papillomavirus E7 has the same effect as the murine polyomavirus small T protein. In summary, we report several new functions for the papillomavirus E7 proteins, which will contribute new insights into the roles of viruses in cancer and the cellular pathways they perturb in carcinogenesis. PMID:25540383

The calculations of small molecular conformation energy differences by density functional method

NASA Astrophysics Data System (ADS)

Topol, I. A.; Burt, S. K.

1993-03-01

The differences in the conformational energies for the gauche (G) and trans(T) conformers of 1,2-difluoroethane and for myo-and scyllo-conformer of inositol have been calculated by local density functional method (LDF approximation) with geometry optimization using different sets of calculation parameters. It is shown that in the contrast to Hartree—Fock methods, density functional calculations reproduce the correct sign and value of the gauche effect for 1,2-difluoroethane and energy difference for both conformers of inositol. The results of normal vibrational analysis for1,2-difluoroethane showed that harmonic frequencies calculated in LDF approximation agree with experimental data with the accuracy typical for scaled large basis set Hartree—Fock calculations.

Polymers in Small-Interfering RNA Delivery

PubMed Central

Singha, Kaushik; Namgung, Ran

2011-01-01

This review will cover the current strategies that are being adopted to efficiently deliver small interfering RNA using nonviral vectors, including the use of polymers such as polyethylenimine, poly(lactic-co-glycolic acid), polypeptides, chitosan, cyclodextrin, dendrimers, and polymers-containing different nanoparticles. The article will provide a brief and concise account of underlying principle of these polymeric vectors and their structural and functional modifications which were intended to serve different purposes to affect efficient therapeutic outcome of small-interfering RNA delivery. The modifications of these polymeric vectors will be discussed with reference to stimuli-responsiveness, target specific delivery, and incorporation of nanoconstructs such as carbon nanotubes, gold nanoparticles, and silica nanoparticles. The emergence of small-interfering RNA as the potential therapeutic agent and its mode of action will also be mentioned in a nutshell. PMID:21749290

Aptamer Recognition of Multiplexed Small-Molecule-Functionalized Substrates.

PubMed

Nakatsuka, Nako; Cao, Huan H; Deshayes, Stephanie; Melkonian, Arin Lucy; Kasko, Andrea M; Weiss, Paul S; Andrews, Anne M

2018-05-31

Aptamers are chemically synthesized oligonucleotides or peptides with molecular recognition capabilities. We investigated recognition of substrate-tethered small-molecule targets, using neurotransmitters as examples, and fluorescently labeled DNA aptamers. Substrate regions patterned via microfluidic channels with dopamine or L-tryptophan were selectively recognized by previously identified dopamine or L-tryptophan aptamers, respectively. The on-substrate dissociation constant determined for the dopamine aptamer was comparable to, though slightly greater than the previously determined solution dissociation constant. Using pre-functionalized neurotransmitter-conjugated oligo(ethylene glycol) alkanethiols and microfluidics patterning, we produced multiplexed substrates to capture and to sort aptamers. Substrates patterned with L-DOPA, L-DOPS, and L-5-HTP enabled comparison of the selectivity of the dopamine aptamer for different targets via simultaneous determination of in situ binding constants. Thus, beyond our previous demonstrations of recognition by protein binding partners (i.e., antibodies and G-protein-coupled receptors), strategically optimized small-molecule-functionalized substrates show selective recognition of nucleic acid binding partners. These substrates are useful for side-by-side target comparisons, and future identification and characterization of novel aptamers targeting neurotransmitters or other important small-molecules.

Differential Sensitivity of Target Genes to Translational Repression by miR-17~92

PubMed Central

Jin, Hyun Yong; Oda, Hiroyo; Chen, Pengda; Kang, Seung Goo; Valentine, Elizabeth; Liao, Lujian; Zhang, Yaoyang; Gonzalez-Martin, Alicia; Shepherd, Jovan; Head, Steven R.; Kim, Pyeung-Hyeun; Fu, Guo; Liu, Wen-Hsien; Han, Jiahuai

2017-01-01

MicroRNAs (miRNAs) are thought to exert their functions by modulating the expression of hundreds of target genes and each to a small degree, but it remains unclear how small changes in hundreds of target genes are translated into the specific function of a miRNA. Here, we conducted an integrated analysis of transcriptome and translatome of primary B cells from mutant mice expressing miR-17~92 at three different levels to address this issue. We found that target genes exhibit differential sensitivity to miRNA suppression and that only a small fraction of target genes are actually suppressed by a given concentration of miRNA under physiological conditions. Transgenic expression and deletion of the same miRNA gene regulate largely distinct sets of target genes. miR-17~92 controls target gene expression mainly through translational repression and 5’UTR plays an important role in regulating target gene sensitivity to miRNA suppression. These findings provide molecular insights into a model in which miRNAs exert their specific functions through a small number of key target genes. PMID:28241004

tRNA-Derived Small RNA: A Novel Regulatory Small Non-Coding RNA.

PubMed

Li, Siqi; Xu, Zhengping; Sheng, Jinghao

2018-05-10

Deep analysis of next-generation sequencing data unveils numerous small non-coding RNAs with distinct functions. Recently, fragments derived from tRNA, named as tRNA-derived small RNA (tsRNA), have attracted broad attention. There are mainly two types of tsRNAs, including tRNA-derived stress-induced RNA (tiRNA) and tRNA-derived fragment (tRF), which differ in the cleavage position of the precursor or mature tRNA transcript. Emerging evidence has shown that tsRNAs are not merely tRNA degradation debris but have been recognized to play regulatory roles in many specific physiological and pathological processes. In this review, we summarize the biogeneses of various tsRNAs, present the emerging concepts regarding functions and mechanisms of action of tsRNAs, highlight the potential application of tsRNAs in human diseases, and put forward the current problems and future research directions.

Ethnic Differences in Completion Rates as a Function of School Size in Texas High Schools

ERIC Educational Resources Information Center

Fitzgerald, Kim; Gordon, Teandra; Canty, Antoinette; Stitt, Ruth E.; Onwuegbuzie, Anthony J.; Frels, Rebecca K.

2013-01-01

The purpose of this study was to investigate differences in high school completion rates among White, African American, and Hispanic students enrolled in different school sizes--small, medium, and large. For this causal-comparative research design, this study utilized archival data from the Texas Education Association's Academic Excellence…

Detection of Extensive Cosmic Air Showers by Small Scintillation Detectors with Wavelength-Shifting Fibres

ERIC Educational Resources Information Center

Aiola, Salvatore; La Rocca, Paola; Riggi, Francesco; Riggi, Simone

2012-01-01

A set of three small scintillation detectors was employed to measure correlated events due to the passage of cosmic muons originating from extensive air showers. The coincidence rate between (any) two detectors was extracted as a function of their relative distance. The difference between the arrival times in three non-aligned detectors was used…

Small-Molecule Inhibitors of Urea Transporters

PubMed Central

Verkman, Alan S.; Esteva-Font, Cristina; Cil, Onur; Anderson, Marc O.; Li, Fei; Li, Min; Lei, Tianluo; Ren, Huiwen; Yang, Baoxue

2015-01-01

Urea transporter (UT) proteins, which include isoforms of UT-A in kidney tubule epithelia and UT-B in vasa recta endothelia and erythrocytes, facilitate urinary concentrating function. Inhibitors of urea transporter function have potential clinical applications as sodium-sparing diuretics, or ‘urearetics,’ in edema from different etiologies, such as congestive heart failure and cirrhosis, as well as in syndrome of inappropriate antidiuretic hormone (SIADH). High-throughput screening of drug-like small molecules has identified UT-A and UT-B inhibitors with nanomolar potency. Inhibitors have been identified with different UT-A versus UT-B selectivity profiles and putative binding sites on UT proteins. Studies in rodent models support the utility of UT inhibitors in reducing urinary concentration, though testing in clinically relevant animal models of edema has not yet been done. PMID:25298345

High-throughput screening based on label-free detection of small molecule microarrays

NASA Astrophysics Data System (ADS)

Zhu, Chenggang; Fei, Yiyan; Zhu, Xiangdong

2017-02-01

Based on small-molecule microarrays (SMMs) and oblique-incidence reflectivity difference (OI-RD) scanner, we have developed a novel high-throughput drug preliminary screening platform based on label-free monitoring of direct interactions between target proteins and immobilized small molecules. The screening platform is especially attractive for screening compounds against targets of unknown function and/or structure that are not compatible with functional assay development. In this screening platform, OI-RD scanner serves as a label-free detection instrument which is able to monitor about 15,000 biomolecular interactions in a single experiment without the need to label any biomolecule. Besides, SMMs serves as a novel format for high-throughput screening by immobilization of tens of thousands of different compounds on a single phenyl-isocyanate functionalized glass slide. Based on the high-throughput screening platform, we sequentially screened five target proteins (purified target proteins or cell lysate containing target protein) in high-throughput and label-free mode. We found hits for respective target protein and the inhibition effects for some hits were confirmed by following functional assays. Compared to traditional high-throughput screening assay, the novel high-throughput screening platform has many advantages, including minimal sample consumption, minimal distortion of interactions through label-free detection, multi-target screening analysis, which has a great potential to be a complementary screening platform in the field of drug discovery.

Role of miRNAs and siRNAs in biotic and abiotic stress responses of plants

PubMed Central

Khraiwesh, Basel; Zhu, Jian-Kang; Zhu, Jianhua

2011-01-01

Small, non-coding RNAs are a distinct class of regulatory RNAs in plants and animals that control a variety of biological processes. In plants, several classes of small RNAs with specific sizes and dedicated functions have evolved through a series of pathways. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs control the expression of cognate target genes by binding to reverse complementary sequences, resulting in cleavage or translational inhibition of the target RNAs. siRNAs have a similar structure, function, and biogenesis as miRNAs but are derived from long double-stranded RNAs and can often direct DNA methylation at target sequences. Besides their roles in growth and development and maintenance of genome integrity, small RNAs are also important components in plant stress responses. One way in which plants respond to environmental stress is by modifying their gene expression through the activity of small RNAs. Thus, understanding how small RNAs regulate gene expression will enable researchers to explore the role of small RNAs in biotic and abiotic stress responses. This review focuses on the regulatory roles of plant small RNAs in the adaptive response to stresses. PMID:21605713

Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization

PubMed Central

Farrahi, Assal; Sanz-Andrés, Ángel

2013-01-01

A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed. PMID:24501579

Soft functions for generic jet algorithms and observables at hadron colliders

DOE PAGES

Bertolini, Daniele; Kolodrubetz, Daniel; Neill, Duff Austin; ...

2017-07-20

Here, we introduce a method to compute one-loop soft functions for exclusive N - jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the N -jettiness hemisphere decomposition of ref. [1] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti- kT , XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet massmore » and jet broadening, in pp → L + 1 jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius R. We find that the small- R results, including corrections up to O(R 2), accurately capture the full behavior over a large range of R.« less

Soft functions for generic jet algorithms and observables at hadron colliders

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

Bertolini, Daniele; Kolodrubetz, Daniel; Neill, Duff Austin

Here, we introduce a method to compute one-loop soft functions for exclusive N - jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the N -jettiness hemisphere decomposition of ref. [1] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti- kT , XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet massmore » and jet broadening, in pp → L + 1 jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius R. We find that the small- R results, including corrections up to O(R 2), accurately capture the full behavior over a large range of R.« less

Corneal Power Distribution and Functional Optical Zone Following Small Incision Lenticule Extraction for Myopia.

PubMed

Qian, Yishan; Huang, Jia; Zhou, Xingtao; Hanna, Rewais Benjamin

2015-08-01

To evaluate corneal power distribution using the ray tracing method (corneal power) in eyes undergoing small incision lenticule extraction (SMILE) surgery and compare the functional optical zone with two lenticular sizes. This retrospective study evaluated 128 patients who underwent SMILE for the correction of myopia and astigmatism with a lenticular diameter of 6.5 mm (the 6.5-mm group) and 6.2 mm (the 6.2-mm group). The data include refraction, correction, and corneal power obtained via a Scheimpflug camera from the pupil center to 8 mm. The surgically induced changes in corneal power (Δcorneal power) were compared to correction and Δrefraction. The functional optical zone was defined as the largest ring diameter when the difference between the ring power and the pupil center power was 1.50 diopters or less. The functional optical zone was compared between two lenticular diameter groups. Corneal power distribution was measured by the ray tracing method. In the 6.5-mm group (n=100), Δcorneal power at 5 mm showed the smallest difference from Δrefraction and Δcorneal power at 0 mm exhibited the smallest difference from correction. In the 6.2-mm group (n=28), Δcorneal power at 2 mm displayed the lowest dissimilarity from Δrefraction and Δcorneal power at 4 mm demonstrated the lowest dissimilarity from correction. There was no significant difference between the mean postoperative functional optical zones in either group when their spherical equivalents were matched. Total corneal refactive power can be used in the evaluation of surgically induced changes following SMILE. A lenticular diameter of 6.2 mm should be recommended for patients with high myopia because there is no functional difference in the optical zone. Copyright 2015, SLACK Incorporated.

r- and K-selection in fluctuating populations is determined by the evolutionary trade-off between two fitness measures: Growth rate and lifetime reproductive success.

PubMed

Engen, Steinar; Saether, Bernt-Erik

2017-01-01

In a stable environment, evolution maximizes growth rates in populations that are not density regulated and the carrying capacity in the case of density regulation. In a fluctuating environment, evolution maximizes a function of growth rate, carrying capacity and environmental variance, tending to r-selection and K-selection under large and small environmental noise, respectively. Here we analyze a model in which birth and death rates depend on density through the same function but with independent strength of density dependence. As a special case, both functions may be linear, corresponding to logistic dynamics. It is shown that evolution maximizes a function of the deterministic growth rate r 0 and the lifetime reproductive success (LRS) R 0 , both defined at small densities, as well as the environmental variance. Under large noise this function is dominated by r 0 and average lifetimes are small, whereas R 0 dominates and lifetimes are larger under small noise. Thus, K-selection is closely linked to selection for large R 0 so that evolution tends to maximize LRS in a stable environment. Consequently, different quantities (r 0 and R 0 ) tend to be maximized at low and high densities, respectively, favoring density-dependent changes in the optimal life history. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Regional brain volumes and cognition in childhood epilepsy: does size really matter?

PubMed

Zelko, Frank A; Pardoe, Heath R; Blackstone, Sarah R; Jackson, Graeme D; Berg, Anne T

2014-05-01

Recent studies have correlated neurocognitive function and regional brain volumes in children with epilepsy. We tested whether brain volume differences between children with and without epilepsy explained differences in neurocognitive function. The study sample included 108 individuals with uncomplicated non-syndromic epilepsy (NSE) and 36 healthy age- and gender-matched controls. Participants received a standardized cognitive battery. Whole brain T1-weighted MRI was obtained and volumes analyzed with FreeSurfer (TM). Total brain volume (TBV) was significantly smaller in cases. After adjustment for TBV, cases had significantly larger regional grey matter volumes for total, frontal, parietal, and precentral cortex. Cases had poorer performance on neurocognitive indices of intelligence and variability of sustained attention. In cases, TBV showed small associations with intellectual indices of verbal and perceptual ability, working memory, and overall IQ. In controls, TBV showed medium associations with working memory and variability of sustained attention. In both groups, small associations were seen between some TBV-adjusted regional brain volumes and neurocognitive indices, but not in a consistent pattern. Brain volume differences did not account for cognitive differences between the groups. Patients with uncomplicated NSE have smaller brains than controls but areas of relative grey matter enlargement. That this relative regional enlargement occurs in the context of poorer overall neurocognitive functioning suggests that it is not adaptive. However, the lack of consistent associations between case-control differences in brain volumes and cognitive functioning suggests that brain volumes have limited explanatory value for cognitive functioning in childhood epilepsy. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparisons of fish species traits from small streams to large rivers

USGS Publications Warehouse

Goldstein, R.M.; Meador, M.R.

2004-01-01

To examine the relations between fish community function and stream size, we classified 429 lotic freshwater fish species based on multiple categories within six species traits: (1) substrate preference, (2) geomorphic preference, (3) trophic ecology, (4) locomotion morphology, (5) reproductive strategy, and (6) stream size preference. Stream size categories included small streams, small, medium, and large rivers, and no size preference. The frequencies of each species trait category were determined for each stream size category based on life history information from the literature. Cluster analysis revealed the presence of covarying groups of species trait categories. One cluster (RUN) included the traits of planktivore and herbivore feeding ecology, migratory reproductive behavior and broadcast spawning, preferences for main-channel habitats, and a lack of preferences for substrate type. The frequencies of classifications for the RUN cluster varied significantly across stream size categories (P = 0.009), being greater for large rivers than for small streams and rivers. Another cluster (RIFFLE) included the traits of invertivore feeding ecology, simple nester reproductive behavior, a preference for riffles, and a preference for bedrock, boulder, and cobble-rubble substrate. No significant differences in the frequency of classifications among stream size categories were detected for the RIFFLE cluster (P = 0.328). Our results suggest that fish community function is structured by large-scale differences in habitat and is different for large rivers than for small streams and rivers. Our findings support theoretical predictions of variation in species traits among stream reaches based on ecological frameworks such as landscape filters, habitat templates, and the river continuum concept. We believe that the species trait classifications presented here provide an opportunity for further examination of fish species' relations to physical, chemical, and biological factors in lotic habitats ranging from small streams to large rivers.

Intercomparison of fog water samplers

NASA Astrophysics Data System (ADS)

Schell, Dieter; Georgii, Hans-Walter; Maser, Rolf; Jaeschke, Wolfgang; Arends, Beate G.; Kos, Gerard P. A.; Winkler, Peter; Schneider, Thomas; Berner, Axel; Kruisz, Christian

1992-11-01

During the Po Valley Fog Experiment 1989, two fogwater collectors were operated simultaneously at the ground and the results were compared to each other. The chemical analyses of the samples as well as the collection efficiencies showed remarkable differences between both collectors. Some differences in the solute concentrations in the samples of both collectors could be expected due to small differences in the 50-percent cut-off diameters. The large differences in the collection efficiencies however cannot be explained by these small variations of d sub 50, because normally only a small fraction of the water mass is concentrated in the size range of 5-7-micron droplets. It is shown that it is not sufficient to characterize a fogwater collector only by its cut-off diameter. The results of several wind tunnel calibration tests show that the collection efficiencies of the fogwater collectors are a function of windspeed and shape of the droplet spectra.

Eosinophils may play regionally disparate roles in influencing IgA(+) plasma cell numbers during large and small intestinal inflammation.

PubMed

Forman, Ruth; Bramhall, Michael; Logunova, Larisa; Svensson-Frej, Marcus; Cruickshank, Sheena M; Else, Kathryn J

2016-05-31

Eosinophils are innate immune cells present in the intestine during steady state conditions. An intestinal eosinophilia is a hallmark of many infections and an accumulation of eosinophils is also observed in the intestine during inflammatory disorders. Classically the function of eosinophils has been associated with tissue destruction, due to the release of cytotoxic granule contents. However, recent evidence has demonstrated that the eosinophil plays a more diverse role in the immune system than previously acknowledged, including shaping adaptive immune responses and providing plasma cell survival factors during the steady state. Importantly, it is known that there are regional differences in the underlying immunology of the small and large intestine, but whether there are differences in context of the intestinal eosinophil in the steady state or inflammation is not known. Our data demonstrates that there are fewer IgA(+) plasma cells in the small intestine of eosinophil-deficient ΔdblGATA-1 mice compared to eosinophil-sufficient wild-type mice, with the difference becoming significant post-infection with Toxoplasma gondii. Remarkably, and in complete contrast, the absence of eosinophils in the inflamed large intestine does not impact on IgA(+) cell numbers during steady state, and is associated with a significant increase in IgA(+) cells post-infection with Trichuris muris compared to wild-type mice. Thus, the intestinal eosinophil appears to be less important in sustaining the IgA(+) cell pool in the large intestine compared to the small intestine, and in fact, our data suggests eosinophils play an inhibitory role. The dichotomy in the influence of the eosinophil over small and large intestinal IgA(+) cells did not depend on differences in plasma cell growth factors, recruitment potential or proliferation within the different regions of the gastrointestinal tract (GIT). We demonstrate for the first time that there are regional differences in the requirement of eosinophils for maintaining IgA+ cells between the large and small intestine, which are more pronounced during inflammation. This is an important step towards further delineation of the enigmatic functions of gut-resident eosinophils.

Topological Organization of Functional Brain Networks in Healthy Children: Differences in Relation to Age, Sex, and Intelligence

PubMed Central

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C.; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence. PMID:23390528

Long-duration transcutaneous electric acupoint stimulation alters small-world brain functional networks.

PubMed

Zhang, Yue; Jiang, Yin; Glielmi, Christopher B; Li, Longchuan; Hu, Xiaoping; Wang, Xiaoying; Han, Jisheng; Zhang, Jue; Cui, Cailian; Fang, Jing

2013-09-01

Acupuncture, which is recognized as an alternative and complementary treatment in Western medicine, has long shown efficiencies in chronic pain relief, drug addiction treatment, stroke rehabilitation and other clinical practices. The neural mechanism underlying acupuncture, however, is still unclear. Many studies have focused on the sustained effects of acupuncture on healthy subjects, yet there are very few on the topological organization of functional networks in the whole brain in response to long-duration acupuncture (longer than 20 min). This paper presents a novel study on the effects of long-duration transcutaneous electric acupoint stimulation (TEAS) on the small-world properties of brain functional networks. Functional magnetic resonance imaging was used to construct brain functional networks of 18 healthy subjects (9 males and 9 females) during the resting state. All subjects received both TEAS and minimal TEAS (MTEAS) and were scanned before and after each stimulation. An altered functional network was found with lower local efficiency and no significant change in global efficiency for healthy subjects after TEAS, while no significant difference was observed after MTEAS. The experiments also showed that the nodal efficiencies in several paralimbic/limbic regions were altered by TEAS, and those in middle frontal gyrus and other regions by MTEAS. To remove the psychological effects and the baseline, we compared the difference between diffTEAS (difference between after and before TEAS) and diffMTEAS (difference between after and before MTEAS). The results showed that the local efficiency was decreased and that the nodal efficiencies in frontal gyrus, orbitofrontal cortex, anterior cingulate gyrus and hippocampus gyrus were changed. Based on those observations, we conclude that long-duration TEAS may modulate the short-range connections of brain functional networks and also the limbic system. Copyright © 2013 Elsevier Inc. All rights reserved.

Topological organization of functional brain networks in healthy children: differences in relation to age, sex, and intelligence.

PubMed

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence.

Assessment of flood-induced changes of phytoplankton along a river-floodplain system using the morpho-functional approach.

PubMed

Mihaljević, Melita; Spoljarić, Dubravka; Stević, Filip; Zuna Pfeiffer, Tanja

2013-10-01

In this research, we aimed to find out how the differences in hydrological connectivity between the main river channel and adjacent floodplain influence the changes in phytoplankton community structure along a river-floodplain system. The research was performed in the River Danube floodplain (Croatian river section) in the period 2008-2009 characterised by different flooding pattern on an annual time scale. By utilising the morpho-functional approach and multivariate analyses, the flood-derived structural changes of phytoplankton were analysed. The lake stability during the isolation phase triggered the specific pattern of morpho-functional groups (MFG) which were characterised by cyanobacterial species achieving very high biomass. Adversely, the high water turbulence in the lake during the frequent and extreme flooding led to evident similarity between lake and river assemblages. Besides different diatom species (groups of small and large centrics and pennates), which are the most abundant representatives in the river phytoplankton, many other groups such as cryptophytes and colonial phytomonads appeared to indicate altered conditions in the floodplain driven by flooding. Having different functional properties, small centric diatom taxa sorted to only one MFG cannot clearly reflect environmental changes that are shown by the species-level pattern. Disadvantages in using the MFG approach highlight that it is still necessary to combine it with taxonomical approach in monitoring of phytoplankton in the river-floodplain ecosystems.

Knee arthroscopy versus conservative management in patients with degenerative knee disease: a systematic review.

PubMed

Brignardello-Petersen, Romina; Guyatt, Gordon H; Buchbinder, Rachelle; Poolman, Rudolf W; Schandelmaier, Stefan; Chang, Yaping; Sadeghirad, Behnam; Evaniew, Nathan; Vandvik, Per O

2017-05-11

To determine the effects and complications of arthroscopic surgery compared with conservative management strategies in patients with degenerative knee disease. Systematic review. Pain, function, adverse events. MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar and Open Grey up to August 2016. For effects, randomised clinical trials (RCTs) comparing arthroscopic surgery with a conservative management strategy (including sham surgery) in patients with degenerative knee disease. For complications, RCTs and observational studies. Two reviewers independently extracted data and assessed risk of bias for patient-important outcomes. A parallel guideline committee ( BMJ Rapid Recommendations) provided input on the design and interpretation of the systematic review, including selection of patient-important outcomes. We used the GRADE approach to rate the certainty (quality) of the evidence. We included 13 RCTs and 12 observational studies. With respect to pain, the review identified high-certainty evidence that knee arthroscopy results in a very small reduction in pain up to 3 months (mean difference =5.4 on a 100-point scale, 95% CI 2.0 to 8.8) and very small or no pain reduction up to 2 years (mean difference =3.1, 95% CI -0.2 to 6.4) when compared with conservative management. With respect to function, the review identified moderate-certainty evidence that knee arthroscopy results in a very small improvement in the short term (mean difference =4.9 on a 100-point scale, 95% CI 1.5 to 8.4) and very small or no improved function up to 2 years (mean difference =3.2, 95% CI -0.5 to 6.8). Alternative presentations of magnitude of effect, and associated sensitivity analyses, were consistent with the findings of the primary analysis. Low-quality evidence suggested a very low probability of serious complications after knee arthroscopy. Over the long term, patients who undergo knee arthroscopy versus those who receive conservative management strategies do not have important benefits in pain or function. PROSPERO CRD42016046242. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Knee arthroscopy versus conservative management in patients with degenerative knee disease: a systematic review

PubMed Central

Brignardello-Petersen, Romina; Guyatt, Gordon H; Buchbinder, Rachelle; Poolman, Rudolf W; Chang, Yaping; Sadeghirad, Behnam; Evaniew, Nathan; Vandvik, Per O

2017-01-01

Objective To determine the effects and complications of arthroscopic surgery compared with conservative management strategies in patients with degenerative knee disease. Design Systematic review. Main outcome measures Pain, function, adverse events. Data sources MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar and Open Grey up to August 2016. Eligibility criteria For effects, randomised clinical trials (RCTs) comparing arthroscopic surgery with a conservative management strategy (including sham surgery) in patients with degenerative knee disease. For complications, RCTs and observational studies. Review methods Two reviewers independently extracted data and assessed risk of bias for patient-important outcomes. A parallel guideline committee (BMJ Rapid Recommendations) provided input on the design and interpretation of the systematic review, including selection of patient-important outcomes. We used the GRADE approach to rate the certainty (quality) of the evidence. Results We included 13 RCTs and 12 observational studies. With respect to pain, the review identified high-certainty evidence that knee arthroscopy results in a very small reduction in pain up to 3 months (mean difference =5.4 on a 100-point scale, 95% CI 2.0 to 8.8) and very small or no pain reduction up to 2 years (mean difference =3.1, 95% CI −0.2 to 6.4) when compared with conservative management. With respect to function, the review identified moderate-certainty evidence that knee arthroscopy results in a very small improvement in the short term (mean difference =4.9 on a 100-point scale, 95% CI 1.5 to 8.4) and very small or no improved function up to 2 years (mean difference =3.2, 95% CI −0.5 to 6.8). Alternative presentations of magnitude of effect, and associated sensitivity analyses, were consistent with the findings of the primary analysis. Low-quality evidence suggested a very low probability of serious complications after knee arthroscopy. Conclusions Over the long term, patients who undergo knee arthroscopy versus those who receive conservative management strategies do not have important benefits in pain or function. Trial registration number PROSPERO CRD42016046242. PMID:28495819

Optical mapping of prefrontal brain connectivity and activation during emotion anticipation.

PubMed

Wang, Meng-Yun; Lu, Feng-Mei; Hu, Zhishan; Zhang, Juan; Yuan, Zhen

2018-09-17

Accumulated neuroimaging evidence shows that the dorsal lateral prefrontal cortex (dlPFC) is activated during emotion anticipation. The aim of this work is to examine the brain connectivity and activation differences in dlPFC between the positive, neutral and negative emotion anticipation by using functional near-infrared spectroscopy (fNIRS). The hemodynamic responses were first assessed for all subjects during the performance of various emotion anticipation tasks. And then small-world analysis was performed, in which the small-world network indicators including the clustering coefficient, average path length, average node degree, and measure of small-world index were calculated for the functional brain networks associated with the positive, neutral and negative emotion anticipation, respectively. We discovered that compared to negative and neutral emotion anticipation, the positive one exhibited enhanced brain activation in the left dlPFC. Although the functional brain networks for the three emotion anticipation cases manifested the small-world properties regarding the clustering coefficient, average path length, average node degree, and measure of small-world index, the positive one showed significantly higher clustering coefficient and shorter average path length than those from the neutral and negative cases. Consequently, the small-world network indicators and brain activation in dlPPC were able to distinguish well between the positive, neutral and negative emotion anticipation. Copyright © 2018 Elsevier B.V. All rights reserved.

Principles of Considering the Effect of the Limited Volume of a System on Its Thermodynamic State

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2018-01-01

The features of a system with a finite volume that affect its thermodynamic state are considered in comparison to describing small bodies in macroscopic phases. Equations for unary and pair distribution functions are obtained using difference derivatives of a discrete statistical sum. The structure of the equation for the free energy of a system consisting of an ensemble of volume-limited regions with different sizes and a full set of equations describing a macroscopic polydisperse system are discussed. It is found that the equations can be applied to molecular adsorption on small faces of microcrystals, to bound and isolated pores of a polydisperse material, and to describe the spinodal decomposition of a fluid in brief periods of time and high supersaturations of the bulk phase when each local region functions the same on average. It is shown that as the size of a system diminishes, corrections must be introduced for the finiteness of the system volume and fluctuations of the unary and pair distribution functions.

RNAi pathways in Mucor: A tale of proteins, small RNAs and functional diversity.

PubMed

Torres-Martínez, Santiago; Ruiz-Vázquez, Rosa M

2016-05-01

The existence of an RNA-mediated silencing mechanism in the opportunistic fungal pathogen Mucor circinelloides was first described in the early 2000. Since then, Mucor has reached an outstanding position within the fungal kingdom as a model system to achieve a deeper understanding of regulation of endogenous functions by the RNA interference (RNAi) machinery. M. circinelloides combines diverse components of its RNAi machinery to carry out functions not only limited to the defense against invasive nucleic acids, but also to regulate expression of its own genes by producing different classes of endogenous small RNA molecules (esRNAs). The recent discovery of a novel RNase that participates in a new RNA degradation pathway adds more elements to the gene silencing-mediated regulation. This review focuses on esRNAs in M. circinelloides, the different pathways involved in their biogenesis, and their roles in regulating specific physiological and developmental processes in response to environmental signals, highlighting the complexity of silencing-mediated regulation in fungi. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of small increases in corticosterone levels on morphology, immune function, and feather development.

PubMed

Butler, Michael W; Leppert, Lynda L; Dufty, Alfred M

2010-01-01

Stressors encountered during avian development may affect an individual's phenotype, including immunocompetence, growth, and feather quality. We examined effects of simulated chronic low-level stress on American kestrel (Falco sparverius) nestlings. Continuous release of corticosterone, a hormone involved in the stress response, can model chronic stress in birds. We implanted 13-d-old males with either corticosterone-filled implants or shams and measured their growth, immune function, and feather coloration. We found no significant differences between groups at the end of the weeklong exposure period in morphometrics (mass, tarsus, wing length, and asymmetry), immunocompetence (cutaneous immunity, heterophil/lymphocyte ratio, and humoral immunity), or feather coloration. One week subsequent to implant removal, however, differences were detected. Sham-implanted birds had significantly longer wings and a reduced level of cutaneous immune function compared with those of birds given corticosterone-filled implants. Therefore, increases of only 2 ng/mL in basal corticosterone titer can have small but measurable effects on subsequent avian development.

Diving behaviour and haemoglobin function: the primary structure of the alpha- and beta-chains of the sea turtle (Caretta caretta) and its functional implications.

PubMed

Petruzzelli, R; Aureli, G; Lania, A; Galtieri, A; Desideri, A; Giardina, B

1996-06-15

The amino acid sequence of the alpha- and beta-chains of haemoglobin (Hb) from the loggerhead sea turtle (Caretta caretta) has been determined. Comparison with that of human Hb shows differences in several residues involved in both alpha 1 beta 1 and alpha 1 beta 2 packing contacts. On the whole, in spite of the mutations, the essential characteristics of both interfaces seem to be maintained. The functional properties of the sea turtle Hb have been investigated at different temperatures and as a function of proton, chloride and organic phosphate concentrations. In addition to overall similarities shared with most of the vertebrate Hbs previously described, this molecule shows significant differences which could be related to the life behaviour of the turtle. In fact, while the shape of the Bohr-effect curve is well adapted for gas exchange during prolonged dives, the very small enthalpy change for O2 binding ensures that O2 delivery becomes essentially insensitive to the temperature changes of the environment. Moreover, and similarly to the case of emperor penguin Hb, the small alkaline Bohr effect appears to be only choride-linked, since the pH dependence of the O2 affinity is abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha- and beta-chains.

Experimental Evolution and Heart Function in Drosophila.

PubMed

Shahrestani, Parvin; Burke, Molly K; Birse, Ryan; Kezos, James N; Ocorr, Karen; Mueller, Laurence D; Rose, Michael R; Bodmer, Rolf

Drosophila melanogaster is a good model species for the study of heart function. However, most previous work on D. melanogaster heart function has focused on the effects of large-effect genetic variants. We compare heart function among 18 D. melanogaster populations that have been selected for altered development time, aging, or stress resistance. We find that populations with faster development and faster aging have increased heart dysfunction, measured as percentage heart failure after electrical pacing. Experimental evolution of different triglyceride levels, by contrast, has little effect on heart function. Evolved differences in heart function correlate with allele frequency changes at many loci of small effect. Genomic analysis of these populations produces a list of candidate loci that might affect cardiac function at the intersection of development, aging, and metabolic control mechanisms.

Plant Size and Competitive Dynamics along Nutrient Gradients.

PubMed

Goldberg, Deborah E; Martina, Jason P; Elgersma, Kenneth J; Currie, William S

2017-08-01

Resource competition theory in plants has focused largely on resource acquisition traits that are independent of size, such as traits of individual leaves or roots or proportional allocation to different functions. However, plants also differ in maximum potential size, which could outweigh differences in module-level traits. We used a community ecosystem model called mondrian to investigate whether larger size inevitably increases competitive ability and how size interacts with nitrogen supply. Contrary to the conventional wisdom that bigger is better, we found that invader success and competitive ability are unimodal functions of maximum potential size, such that plants that are too large (or too small) are disproportionately suppressed by competition. Optimal size increases with nitrogen supply, even when plants compete for nitrogen only in a size-symmetric manner, although adding size-asymmetric competition for light does substantially increase the advantage of larger size at high nitrogen. These complex interactions of plant size and nitrogen supply lead to strong nonlinearities such that small differences in nitrogen can result in large differences in plant invasion success and the influence of competition along productivity gradients.

Variation of parameters using Battin's universal functions

NASA Astrophysics Data System (ADS)

Burton, James R., III; Melton, Robert G.

This paper presents a variation of parameters analysis, suitable for use in situations involving small perturbations to the two-body problem, using Battin's universal functions. Unlike the universal variable formulation, this approach avoids the need to switch among different functional representations if the orbit transitions from elliptical, through parabolic, to hyperbolic state, making it attractive for use in simulating low-thrust trajectories ascending to escape or capturing into orbit.

Observing and Understanding Arterial and Venous Circulation Differences in a Physiology Laboratory Activity

ERIC Educational Resources Information Center

Altermann, Caroline; Gonçalves, Rithiele; Lara, Marcus Vinícius S.; Neves, Ben-Hur S.; Mello-Carpes, Pâmela B.

2015-01-01

The purpose of the present article is to describe three simple practical experiments that aim to observe and discuss the anatomic and physiological functions and differences between arteries and veins as well as the alterations observed in skin blood flow in different situations. For this activity, students were divided in small groups. In each…

Characterization of Window Functions for Regularization of Electrical Capacitance Tomography Image Reconstruction

NASA Astrophysics Data System (ADS)

Jiang, Peng; Peng, Lihui; Xiao, Deyun

2007-06-01

This paper presents a regularization method by using different window functions as regularization for electrical capacitance tomography (ECT) image reconstruction. Image reconstruction for ECT is a typical ill-posed inverse problem. Because of the small singular values of the sensitivity matrix, the solution is sensitive to the measurement noise. The proposed method uses the spectral filtering properties of different window functions to make the solution stable by suppressing the noise in measurements. The window functions, such as the Hanning window, the cosine window and so on, are modified for ECT image reconstruction. Simulations with respect to five typical permittivity distributions are carried out. The reconstructions are better and some of the contours are clearer than the results from the Tikhonov regularization. Numerical results show that the feasibility of the image reconstruction algorithm using different window functions as regularization.

Chemicals as the Sole Transformers of Cell Fate.

PubMed

Ebrahimi, Behnam

2016-05-30

Forced expression of lineage-specific transcription factors in somatic cells can result in the generation of different cell types in a process named direct reprogramming, bypassing the pluripotent state. However, the introduction of transgenes limits the therapeutic applications of the produced cells. Numerous small-molecules have been introduced in the field of stem cell biology capable of governing self-renewal, reprogramming, transdifferentiation and regeneration. These chemical compounds are versatile tools for cell fate conversion toward desired outcomes. Cell fate conversion using small-molecules alone (chemical reprogramming) has superiority over arduous traditional genetic techniques in several aspects. For instance, rapid, transient, and reversible effects in activation and inhibition of functions of specific proteins are of the profits of small-molecules. They are cost-effective, have a long half-life, diversity on structure and function, and allow for temporal and flexible regulation of signaling pathways. Additionally, their effects could be adjusted by fine-tuning concentrations and combinations of different small-molecules. Therefore, chemicals are powerful tools in cell fate conversion and study of stem cell and chemical biology in vitro and in vivo. Moreover, transgene-free and chemical-only transdifferentiation approaches provide alternative strategies for the generation of various cell types, disease modeling, drug screening, and regenerative medicine. The current review gives an overview of the recent findings concerning transdifferentiation by only small-molecules without the use of transgenes.

Physical activity and trajectories in cognitive function: English Longitudinal Study of Ageing.

PubMed

Hamer, Mark; Muniz Terrera, Graciela; Demakakos, Panayotes

2018-06-01

There are limited data on physical activity in relation to trajectories in cognitive function. The aim was to examine the association of physical activity with trajectories in cognitive function, measured from repeated assessments over 10 years. We conducted a 10-year follow-up of 10 652 (aged 65±10.1 years) men and women from the English Longitudinal Study of Ageing, a cohort of community dwelling older adults. Self-reported physical activity was assessed at baseline and neuropsychological tests of memory and executive function were administered at regular 2-year intervals. Data from six repeated measurements of memory over 10 years and five repeated measurements of executive function over 8 years were used. The multivariable models revealed relatively small baseline differences in cognitive function by physical activity status in both men and women. Over the 10-year follow-up, physically inactive women experienced a greater decline in their memory (-0.20 recalled words, 95% CI -0.29 to -0.11, per study wave) and in executive function ability (-0.33 named animals; -0.54 to -0.13, per study wave) in comparison with the vigorously active reference group. In men, there were no differences in memory (-0.08 recalled words, 95% CI -0.18 to 0.01, per study wave), but small differences in executive function (-0.23 named animals; -0.46 to -0.01, per study wave) between inactive and vigorously active. Physical activity was associated with preservation of memory and executive function over 10 years follow-up. The results were, however, more pronounced in women. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Pulmonary function test findings in patients with acute inhalation injury caused by smoke bombs

PubMed Central

Cao, Lu; Zhang, Xin-Gang; Wang, Jian-Guo; Wang, Han-Bin; Chen, Yi-Bing; Zhao, Da-Hui; Shi, Wen-Fang

2016-01-01

Background This study aimed to determine the effects of smoke bomb-induced acute inhalation injury on pulmonary function at different stages of lung injury. Methods We performed pulmonary function tests (PFTs) in 15 patients with acute inhalation injury from days 3 to 180 after smoke inhalation. We measured the trace element zinc in whole blood on days 4 and 17, and correlations of zinc levels with PFTs were performed. Results In the acute stage of lung injury (day 3), 3 of 11 patients with mild symptoms had normal pulmonary function and 8 patients with restrictive ventilatory dysfunction and reduced diffusing capacity. Some patients also had mild obstructive ventilatory dysfunction (5 patients) and a decline in small airway function (6 patients). For patients with severe symptoms, PFT results showed moderate to severe restrictive ventilatory dysfunction and reduced diffusing capacity. PaCO2 was significantly higher (P=0.047) in patients with reduced small airway function compared with those with normal small airway function. Whole blood zinc levels in the convalescence stage (day 17) were significantly lower than those in the acute stage (day 4). Zinc in the acute stage was negatively correlated with DLCO/VA on days 3, 10, and 46 (r=−0.633, −0.676, and −0.675 respectively, P<0.05). Conclusions Smoke inhalation injury mainly causes restrictive ventilatory dysfunction and reduced diffusing capacity, and causes mild obstructive ventilatory dysfunction and small airway function decline in some patients. Zinc is negatively correlated with DLCO/VA. Zinc levels may be able to predict prognosis and indicate the degree of lung injury. PMID:28066595

A density difference based analysis of orbital-dependent exchange-correlation functionals

NASA Astrophysics Data System (ADS)

Grabowski, Ireneusz; Teale, Andrew M.; Fabiano, Eduardo; Śmiga, Szymon; Buksztel, Adam; Della Sala, Fabio

2014-03-01

We present a density difference based analysis for a range of orbital-dependent Kohn-Sham functionals. Results for atoms, some members of the neon isoelectronic series and small molecules are reported and compared with ab initio wave function calculations. Particular attention is paid to the quality of approximations to the exchange-only optimised effective potential (OEP) approach: we consider both the localised Hartree-Fock as well as the Krieger-Li-Iafrate methods. Analysis of density differences at the exchange-only level reveals the impact of the approximations on the resulting electronic densities. These differences are further quantified in terms of the ground state energies, frontier orbital energy differences and highest occupied orbital energies obtained. At the correlated level, an OEP approach based on a perturbative second-order correlation energy expression is shown to deliver results comparable with those from traditional wave function approaches, making it suitable for use as a benchmark against which to compare standard density functional approximations.

Uniting functional network topology and oscillations in the fronto-parietal single unit network of behaving primates.

PubMed

Dann, Benjamin; Michaels, Jonathan A; Schaffelhofer, Stefan; Scherberger, Hansjörg

2016-08-15

The functional communication of neurons in cortical networks underlies higher cognitive processes. Yet, little is known about the organization of the single neuron network or its relationship to the synchronization processes that are essential for its formation. Here, we show that the functional single neuron network of three fronto-parietal areas during active behavior of macaque monkeys is highly complex. The network was closely connected (small-world) and consisted of functional modules spanning these areas. Surprisingly, the importance of different neurons to the network was highly heterogeneous with a small number of neurons contributing strongly to the network function (hubs), which were in turn strongly inter-connected (rich-club). Examination of the network synchronization revealed that the identified rich-club consisted of neurons that were synchronized in the beta or low frequency range, whereas other neurons were mostly non-oscillatory synchronized. Therefore, oscillatory synchrony may be a central communication mechanism for highly organized functional spiking networks.

Variations in Figurative Language Use as a Function of Mode of Communication

ERIC Educational Resources Information Center

Boerger, Michael A.

2005-01-01

Various studies have demonstrated that the mode by which people communicate affects the content of their messages. The present study examines the ways in which one aspect of language use, namely figurative language, differs as a function of mode of communication. Subjects worked together in pairs to build a small household appliance, with an…

The universal function in color dipole model

NASA Astrophysics Data System (ADS)

Jalilian, Z.; Boroun, G. R.

2017-10-01

In this work we review color dipole model and recall properties of the saturation and geometrical scaling in this model. Our primary aim is determining the exact universal function in terms of the introduced scaling variable in different distance than the saturation radius. With inserting the mass in calculation we compute numerically the contribution of heavy productions in small x from the total structure function by the fraction of universal functions and show the geometrical scaling is established due to our scaling variable in this study.

Statistical characterization of Earth’s heterogeneities from seismic scattering

NASA Astrophysics Data System (ADS)

Zheng, Y.; Wu, R.

2009-12-01

The distortion of a teleseismic wavefront carries information about the heterogeneities through which the wave propagates and it is manifestited as logarithmic amplitude (logA) and phase fluctuations of the direct P wave recorded by a seismic network. By cross correlating the fluctuations (e.g., logA-logA or phase-phase), we obtain coherence functions, which depend on spatial lags between stations and incident angles between the incident waves. We have mathematically related the depth-dependent heterogeneity spectrum to the observable coherence functions using seismic scattering theory. We will show that our method has sharp depth resolution. Using the HiNet seismic network data in Japan, we have inverted power spectra for two depth ranges, ~0-120km and below ~120km depth. The coherence functions formed by different groups of stations or by different groups of earthquakes at different back azimuths are similar. This demonstrates that the method is statistically stable and the inhomogeneities are statistically stationary. In both depth intervals, the trend of the spectral amplitude decays from large scale to small scale in a power-law fashion with exceptions at ~50km for the logA data. Due to the spatial spacing of the seismometers, only information from length scale 15km to 200km is inverted. However our scattering method provides new information on small to intermediate scales that are comparable to scales of the recycled materials and thus is complimentary to the global seismic tomography which reveals mainly large-scale heterogeneities on the order of ~1000km. The small-scale heterogeneities revealed here are not likely of pure thermal origin. Therefore, the length scale and strength of heterogeneities as a function of depth may provide important constraints in mechanical mixing of various components in the mantle convection.

Low-temperature transport in out-of-equilibrium XXZ chains

NASA Astrophysics Data System (ADS)

Bertini, Bruno; Piroli, Lorenzo

2018-03-01

We study the low-temperature transport properties of out-of-equilibrium XXZ spin-1/2 chains. We consider the protocol where two semi-infinite chains are prepared in two thermal states at small but different temperatures and suddenly joined together. We focus on the qualitative and quantitative features of the profiles of local observables, which at large times t and distances x from the junction become functions of the ratio \\zeta=x/t . By means of the generalized hydrodynamic equations, we analyse the rich phenomenology arising by considering different regimes of the phase diagram. In the gapped phases, variations of the profiles are found to be exponentially small in the temperatures, but described by non-trivial functions of ζ. We provide analytical formulae for the latter, which give accurate results also for small but finite temperatures. In the gapless regime, we show how the three-step conformal predictions for the profiles of energy density and energy current are naturally recovered from the hydrodynamic equations. Moreover, we also recover the recent non-linear Luttinger liquid predictions for low-temperature transport: universal peaks of width \

SU-F-T-66: Characteristics of Electron Beams From Varian Trubeam

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

Dimofte, A; Kennedy, C; Zhu, T

2016-06-15

Purpose: The purpose of this study was to compare the electron beam data between Truebeam and 2300ix Varian accelerators for percent depth dose for broad beam and small circular cutouts, cone factors, head scatter factor as a function of cone size and SSD, phantom scatter factor, blocking factor, distance factor and virtual source position. Methods: Measurements were performed for Truebeam and 2300ix Varian accelerators. The main energies used were: 6, 9, 12, 16 and 20 MeV. PDD was measured at SSD = 100 cm for open beam and small circular cutouts (r = 0.5, 1.0, 1.5, 2.0, 3.0, 4.0 andmore » 6.6cm) for different energies. Measurements to determine the head scatter factor (H) were done as a function of radius for six representative energies and five cone sizes (6, 10, 15, 20 and 25cm2). The phantom scatter factor (PSF) is defined as the ratio of blocking factor in water at reference depth and head scatter factor in air. PSF was measured as a function of radius and electron energy. Distance factor was measured for all energies and cones for three SSD’s (100, 110 and 120cm). Results: The percent depth dose (PDD) was measured for small cutouts of radius r = 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0 and 5.6cm. Blocking factor (BF) was measured for Truebeam and 2300ix accelerators, for different circular cutouts and energies for a 10×10 cone. Cone factors were compared between the two accelerators for different energies and applicator sizes. Conclusion: Cone factors measured for the two accelerator types differ by up to 5% for the largest applicator size. Blocking factors differs by up to 3%, with the largest variation for the smallest field size (0.5cm). Distance factor for different SSD’s differ by up to 4.5%.« less

Variation in trait trade-offs allows differentiation among predefined plant functional types: implications for predictive ecology.

PubMed

Verheijen, Lieneke M; Aerts, Rien; Bönisch, Gerhard; Kattge, Jens; Van Bodegom, Peter M

2016-01-01

Plant functional types (PFTs) aggregate the variety of plant species into a small number of functionally different classes. We examined to what extent plant traits, which reflect species' functional adaptations, can capture functional differences between predefined PFTs and which traits optimally describe these differences. We applied Gaussian kernel density estimation to determine probability density functions for individual PFTs in an n-dimensional trait space and compared predicted PFTs with observed PFTs. All possible combinations of 1-6 traits from a database with 18 different traits (total of 18 287 species) were tested. A variety of trait sets had approximately similar performance, and 4-5 traits were sufficient to classify up to 85% of the species into PFTs correctly, whereas this was 80% for a bioclimatically defined tree PFT classification. Well-performing trait sets included combinations of correlated traits that are considered functionally redundant within a single plant strategy. This analysis quantitatively demonstrates how structural differences between PFTs are reflected in functional differences described by particular traits. Differentiation between PFTs is possible despite large overlap in plant strategies and traits, showing that PFTs are differently positioned in multidimensional trait space. This study therefore provides the foundation for important applications for predictive ecology. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Human Milk: Bioactive Proteins/Peptides and Functional Properties.

PubMed

Lönnerdal, Bo

2016-06-23

Breastfeeding has been associated with many benefits, both in the short and in the long term. Infants being breastfed generally have less illness and have better cognitive development at 1 year of age than formula-fed infants. Later in life, they have a lower risk of obesity, diabetes and cardiovascular disease. Several components in breast milk may be responsible for these different outcomes, but bioactive proteins/peptides likely play a major role. Some proteins in breast milk are comparatively resistant towards digestion and may therefore exert their functions in the gastrointestinal tract in intact form or as larger fragments. Other milk proteins may be partially digested in the upper small intestine and the resulting peptides may exert functions in the lower small intestine. Lactoferrin, lysozyme and secretory IgA have been found intact in the stool of breastfed infants and are therefore examples of proteins that are resistant against proteolytic degradation in the gut. Together, these proteins serve protective roles against infection and support immune function in the immature infant. α-lactalbumin, β-casein, κ-casein and osteopontin are examples of proteins that are partially digested in the upper small intestine, and the resulting peptides influence functions in the gut. Such functions include stimulation of immune function, mineral and trace element absorption and defense against infection. © 2016 Nestec Ltd., Vevey/S. Karger AG, Basel.

Value of in vivo electrophysiological measurements to evaluate canine small bowel autotransplants.

PubMed Central

Meijssen, M A; Heineman, E; de Bruin, R W; Veeze, H J; Bijman, J; de Jonge, H R; ten Kate, F J; Marquet, R L; Molenaar, J C

1991-01-01

This study aimed to develop a non-invasive method for in vivo measurement of the transepithelial potential difference in the canine small bowel and to evaluate this parameter in small bowel autotransplants. In group 0 (control group, n = 4), two intestinal loops were created without disturbing their vascular, neural, and lymphatic supplies. In group I (successful autotransplants, n = 11), two heterotopic small bowel loops were constructed. Long term functional sequelae of vascular, neural, and lymphatic division were studied. Group II (n = 6) consisted of dogs with unsuccessful autotransplants suffering thrombosis of the vascular anastomosis, which resulted in ischaemic small bowel autografts. In group I, values of spontaneous transepithelial potential difference, an index of base line active electrolyte transport, were significantly lower compared with group 0 (p less than 0.05), probably as a result of denervation of the autotransplants. Both theophylline and glucose stimulated potential difference responses, measuring cyclic adenosine monophosphate mediated chloride secretion and sodium coupled glucose absorption respectively, showed negative luminal values in group I at all time points after transplantation. These transepithelial potential difference responses diminished progressively with time. From day 21 onwards both theophylline and glucose stimulated potential difference responses were significantly less than the corresponding responses at day seven (p less than 0.05). Morphometric analysis showed that the reduction of transepithelial potential difference responses preceded degenerative mucosal changes in the heterotopic small bowel autografts. In group II, potential difference responses to theophylline and glucose showed positive luminal values (p<0.01 v group I), probably as a result of passive potassium effusion from necrotic enterocytes. Images Figure 3 PMID:1752464

Power Profiles and In Vitro Optical Quality of Scleral Contact Lenses: Effect of the Aperture and Power.

PubMed

Domínguez-Vicent, Alberto; Esteve-Taboada, Jose Juan; Recchioni, Alberto; Brautaset, Rune

2018-05-01

To assess the power profile and in vitro optical quality of scleral contact lenses with different powers as a function of the optical aperture. The mini and semiscleral contact lenses (Procornea) were measured for five powers per design. The NIMO TR-1504 (Lambda-X) was used to assess the power profile and Zernike coefficients of each contact lens. Ten measurements per lens were taken at 3- and 6-mm apertures. Furthermore, the optical quality of each lens was described in Zernike coefficients, modulation transfer function, and point spread function (PSF). A convolution of each lens PSF with an eye-chart image was also computed. The optical power fluctuated less than 0.5 diopters (D) along the optical zone of each lens. However, the optical power obtained for some lenses did not match with its corresponding nominal one, the maximum difference being 0.5 D. In optical quality, small differences were obtained among all lenses within the same design. Although significant differences were obtained among lenses (P<0.05), these showed small impact in the image quality of each convolution. Insignificant power fluctuations were obtained along the optical zone measured for each scleral lens. Additionally, the optical quality of both lenses has showed to be independent of the lens power within the same aperture.

Small area estimation of proportions with different levels of auxiliary data.

PubMed

Chandra, Hukum; Kumar, Sushil; Aditya, Kaustav

2018-03-01

Binary data are often of interest in many small areas of applications. The use of standard small area estimation methods based on linear mixed models becomes problematic for such data. An empirical plug-in predictor (EPP) under a unit-level generalized linear mixed model with logit link function is often used for the estimation of a small area proportion. However, this EPP requires the availability of unit-level population information for auxiliary data that may not be always accessible. As a consequence, in many practical situations, this EPP approach cannot be applied. Based on the level of auxiliary information available, different small area predictors for estimation of proportions are proposed. Analytic and bootstrap approaches to estimating the mean squared error of the proposed small area predictors are also developed. Monte Carlo simulations based on both simulated and real data show that the proposed small area predictors work well for generating the small area estimates of proportions and represent a practical alternative to the above approach. The developed predictor is applied to generate estimates of the proportions of indebted farm households at district-level using debt investment survey data from India. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Early functional outcome of two different orthotic concepts in ankle sprains: a randomized controlled trial.

PubMed

Best, Raymond; Böhle, Caroline; Schiffer, Thorsten; Petersen, Wolf; Ellermann, Andree; Brueggemann, Gert Peter; Liebau, Christian

2015-07-01

Purpose of the study was the evaluation of the early functional outcome of patients with an acute ankle sprain treated either with a semirigid, variable, phase-adapted modular ankle orthosis or an invariable orthotic reference device. Forty-seven patients with acute ankle sprain grade II or more were included. In addition, 77 healthy controls as a reference were investigated. The injured subjects were treated with one of the two devices by random for 6 weeks. Ankle scores (FAOS, AOFAS) were taken at baseline after injury, 1 and 3 months after injury. Functional performance tests (balance platform, zig zag run, shuttle run, vertical drop jump) were performed at 1 and 3 months after injury. No significant score differences could be found between the two intervention groups except for achieving a preinjury activity level after 3 months only in the modular orthosis group. Postural functional performances (balance test) also showed no significant differences whereas the results of the agility tests revealed small but significant better results in the modular orthosis group in comparison to the invariable orthosis group. Cohen's effect sizes were high. Differences between the two intervention groups were marginal and very small but significant and--regarding Cohen's effect sizes--effective. Especially relating to functional performance, this might be a careful indication that a more effective strategy for promoting a protected, rapid recovery to physical activity after ankle sprains might be achieved by applying a phase-adapted ankle orthosis. Especially in athletic patients, phase-adapted orthosis should be further investigated and considered to ensure fully protected ligament healing as well as to regain early functional recovery.

Impedances of electrochemically impregnated nickel electrodes as functions of potential, KOH concentration, and impregnation method

NASA Technical Reports Server (NTRS)

Reid, Margaret A.

1989-01-01

Impedances of fifteen electrodes form each of the four U.S. manufactures were measured at 0.200 V vs. the Hg/HgO reference electrode. This corresponds to a voltage of 1.145 for a Ni/H2 cell. Measurements were also made of a representative sample of these at 0.44 V. At the higher voltage, the impedances were small and very similar, but at the lower voltage there were major differences between manufacturers. Electrodes from the same manufacturers showed only small differences. The impedances of electrodes from two manufacturers were considerably different in 26 percent KOH from those in 31 percent KOH. These preliminary results seen to correlate with the limited data from earlier life testing of cells from these manufacturers. The impedances of cells being tested for Space Station Freedom are being followed, and more impendance measurements of electrodes are being performed as functions of manufacturer, voltage, electrolyte concentration, and cycle history in hopes of finding better correlations of impedance with life.

Motifs, modules and games in bacteria.

PubMed

Wolf, Denise M; Arkin, Adam P

2003-04-01

Global explorations of regulatory network dynamics, organization and evolution have become tractable thanks to high-throughput sequencing and molecular measurement of bacterial physiology. From these, a nascent conceptual framework is developing, that views the principles of regulation in term of motifs, modules and games. Motifs are small, repeated, and conserved biological units ranging from molecular domains to small reaction networks. They are arranged into functional modules, genetically dissectible cellular functions such as the cell cycle, or different stress responses. The dynamical functioning of modules defines the organism's strategy to survive in a game, pitting cell against cell, and cell against environment. Placing pathway structure and dynamics into an evolutionary context begins to allow discrimination between those physical and molecular features that particularize a species to its surroundings, and those that provide core physiological function. This approach promises to generate a higher level understanding of cellular design, pathway evolution and cellular bioengineering.

Motifs, modules and games in bacteria

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

Wolf, Denise M.; Arkin, Adam P.

2003-04-01

Global explorations of regulatory network dynamics, organization and evolution have become tractable thanks to high-throughput sequencing and molecular measurement of bacterial physiology. From these, a nascent conceptual framework is developing, that views the principles of regulation in term of motifs, modules and games. Motifs are small, repeated, and conserved biological units ranging from molecular domains to small reaction networks. They are arranged into functional modules, genetically dissectible cellular functions such as the cell cycle, or different stress responses. The dynamical functioning of modules defines the organism's strategy to survive in a game, pitting cell against cell, and cell against environment.more » Placing pathway structure and dynamics into an evolutionary context begins to allow discrimination between those physical and molecular features that particularize a species to its surroundings, and those that provide core physiological function. This approach promises to generate a higher level understanding of cellular design, pathway evolution and cellular bioengineering.« less

The Endoplasmic Reticulum Membrane Is Permeable to Small Molecules

PubMed Central

Le Gall, Sylvie; Neuhof, Andrea; Rapoport, Tom

2004-01-01

The lumen of the endoplasmic reticulum (ER) differs from the cytosol in its content of ions and other small molecules, but it is unclear whether the ER membrane is as impermeable as other membranes in the cell. Here, we have tested the permeability of the ER membrane to small, nonphysiological molecules. We report that isolated ER vesicles allow different chemical modification reagents to pass from the outside into the lumen with little hindrance. In permeabilized cells, the ER membrane allows the passage of a small, charged modification reagent that is unable to cross the plasma membrane or the lysosomal and trans-Golgi membranes. A larger polar reagent of ∼5 kDa is unable to pass through the ER membrane. Permeation of the small molecules is passive because it occurs at low temperature in the absence of energy. These data indicate that the ER membrane is significantly more leaky than other cellular membranes, a property that may be required for protein folding and other functions of the ER. PMID:14617815

Design and Manufacturing of Extremely Low Mass Flight Systems

NASA Technical Reports Server (NTRS)

Johnson, Michael R.

2002-01-01

Extremely small flight systems pose some unusual design and manufacturing challenges. The small size of the components that make up the system generally must be built with extremely tight tolerances to maintain the functionality of the assembled item. Additionally, the total mass of the system is extremely sensitive to what would be considered small perturbations in a larger flight system. The MUSES C mission, designed, built, and operated by Japan, has a small rover provided by NASA that falls into this small flight system category. This NASA-provided rover is used as a case study of an extremely small flight system design. The issues that were encountered with the rover portion of the MUSES C program are discussed and conclusions about the recommended mass margins at different stages of a small flight system project are presented.

Two decades of climate driving the dynamics of functional and taxonomic diversity of a tropical small mammal community in western Mexico.

PubMed

Mason-Romo, Edgard David; Farías, Ariel A; Ceballos, Gerardo

2017-01-01

Understanding the effects of global climate disruption on biodiversity is important to future conservation efforts. While taxonomic diversity is widely studied, functional diversity of plants, and recently animals, is receiving increasing attention. Most studies of mammals are short-term, focus on temperate habitats, and rely on traits described in the literature rather than generating traits from observations. Unlike previous studies, this long-term field study assessed the factors driving the functional and taxonomic diversity of small-mammal assemblages in dry tropical forests using both traits recorded from literature and a demographic database. We assessed the drivers (abundance and biomass, temperature and rainfall) of taxonomic richness and functional diversity for two rain-driven seasons in two adjacent but distinct forests-upland and lowland (arroyo or riparian) forests. Our analysis found that rainfall, both seasonal and atypical, was the primary factor driving functional and taxonomic diversity of small-mammal assemblages. Functional responses differed between the two types of forests, however, with effects being stronger in the harsher conditions of the upland forests than in the less severe conditions prevailing in the arroyo (riparian) forest. The latter also supports a richer, more diverse, and more stable small-mammal assemblage. These findings highlight the importance of climate to tropical biological diversity, as extreme climate events (hurricanes, droughts and floods) and disruption of rainfall patterns were shown to decrease biodiversity. They also support the need to preserve these habitats, as their high taxonomic diversity and functional redundancy makes them resilient against global climate disruption and local extreme events. Tropical dry forests constitute a potential reservoir for biodiversity and the ecosystem services they provide. Unfortunately, these forests are among the most endangered terrestrial ecosystems because of deforestation and the likely impacts of global climate disruption.

Direct reading inductance meter

NASA Technical Reports Server (NTRS)

Kolby, R. B. (Inventor)

1977-01-01

A direct reading inductance meter comprised of a crystal oscillator and an LC tuned oscillator is presented. The oscillators function respectively to generate a reference frequency, f(r), and to generate an initial frequency, f(0), which when mixed produce a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f(x), a difference frequency (f(r)-f(x)) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

Evaluating the Small-World-Ness of a Sampled Network: Functional Connectivity of Entorhinal-Hippocampal Circuitry

NASA Astrophysics Data System (ADS)

She, Qi; Chen, Guanrong; Chan, Rosa H. M.

2016-02-01

The amount of publicly accessible experimental data has gradually increased in recent years, which makes it possible to reconsider many longstanding questions in neuroscience. In this paper, an efficient framework is presented for reconstructing functional connectivity using experimental spike-train data. A modified generalized linear model (GLM) with L1-norm penalty was used to investigate 10 datasets. These datasets contain spike-train data collected from the entorhinal-hippocampal region in the brains of rats performing different tasks. The analysis shows that entorhinal-hippocampal network of well-trained rats demonstrated significant small-world features. It is found that the connectivity structure generated by distance-dependent models is responsible for the observed small-world features of the reconstructed networks. The models are utilized to simulate a subset of units recorded from a large biological neural network using multiple electrodes. Two metrics for quantifying the small-world-ness both suggest that the reconstructed network from the sampled nodes estimates a more prominent small-world-ness feature than that of the original unknown network when the number of recorded neurons is small. Finally, this study shows that it is feasible to adjust the estimated small-world-ness results based on the number of neurons recorded to provide a more accurate reference of the network property.

Differential Item Functioning for Accommodated Students with Disabilities: Effect of Differences in Proficiency Distributions

ERIC Educational Resources Information Center

Quesen, Sarah

2016-01-01

When studying differential item functioning (DIF) with students with disabilities (SWD) focal groups typically suffer from small sample size, whereas the reference group population is usually large. This makes it possible for a researcher to select a sample from the reference population to be similar to the focal group on the ability scale. Doing…

Plug-and-play design approach to smart harness for modular small satellites

NASA Astrophysics Data System (ADS)

Mughal, M. Rizwan; Ali, Anwar; Reyneri, Leonardo M.

2014-02-01

A typical satellite involves many different components that vary in bandwidth demand. Sensors that require a very low data rate may reside on a simple two- or three-wire interface such as I2C, SPI, etc. Complex sensors that require high data rate and bandwidth may reside on an optical interface. The AraMiS architecture is an enhanced capability architecture with different satellite configurations. Although keeping the low-cost and COTS approach of CubeSats, it extends the modularity concept as it also targets different satellite shapes and sizes. But modularity moves beyond the mechanical structure: the tiles also have thermo-mechanical, harness and signal-processing functionalities. Further modularizing the system, every tile can also host a variable number of small sensors, actuators or payloads, connected using a plug-and-play approach. Every subsystem is housed in a small daughter board and is supplied, by the main tile, with power and data distribution functions, power and data harness, mechanical support and is attached and interconnected with space-grade spring-loaded connectors. The tile software is also modular and allows a quick adaptation to specific subsystems. The basic software for the CPU is properly hardened to guarantee high level of radiation tolerance at very low cost.

Brain regions involved in subprocesses of small-space episodic object-location memory: a systematic review of lesion and functional neuroimaging studies.

PubMed

Zimmermann, Kathrin; Eschen, Anne

2017-04-01

Object-location memory (OLM) enables us to keep track of the locations of objects in our environment. The neurocognitive model of OLM (Postma, A., Kessels, R. P. C., & Van Asselen, M. (2004). The neuropsychology of object-location memory. In G. L. Allen (Ed.), Human spatial memory: Remembering where (pp. 143-160). Mahwah, NJ: Lawrence Erlbaum, Postma, A., Kessels, R. P. C., & Van Asselen, M. (2008). How the brain remembers and forgets where things are: The neurocognition of object-location memory. Neuroscience & Biobehavioral Reviews, 32, 1339-1345. doi: 10.1016/j.neubiorev.2008.05.001 ) proposes that distinct brain regions are specialised for different subprocesses of OLM (object processing, location processing, and object-location binding; categorical and coordinate OLM; egocentric and allocentric OLM). It was based mainly on findings from lesion studies. However, recent episodic memory studies point to a contribution of additional or different brain regions to object and location processing within episodic OLM. To evaluate and update the neurocognitive model of OLM, we therefore conducted a systematic literature search for lesion as well as functional neuroimaging studies contrasting small-space episodic OLM with object memory or location memory. We identified 10 relevant lesion studies and 8 relevant functional neuroimaging studies. We could confirm some of the proposals of the neurocognitive model of OLM, but also differing hypotheses from episodic memory research, about which brain regions are involved in the different subprocesses of small-space episodic OLM. In addition, we were able to identify new brain regions as well as important research gaps.

High intraspecific variability in the functional niche of a predator is associated with ontogenetic shift and individual specialization

PubMed Central

Zhao, Tian; Villéger, Sébastien; Lek, Sovan; Cucherousset, Julien

2014-01-01

Investigations on the functional niche of organisms have primarily focused on differences among species and tended to neglect the potential effects of intraspecific variability despite the fact that its potential ecological and evolutionary importance is now widely recognized. In this study, we measured the distribution of functional traits in an entire population of largemouth bass (Micropterus salmoides) to quantify the magnitude of intraspecific variability in functional traits and niche (size, position, and overlap) between age classes. Stable isotope analyses (δ13C and δ15N) were also used to determine the association between individual trophic ecology and intraspecific functional trait variability. We observed that functional traits were highly variable within the population (mean coefficient variation: 15.62% ± 1.78% SE) and predominantly different between age classes. In addition, functional and trophic niche overlap between age classes was extremely low. Differences in functional niche between age classes were associated with strong changes in trophic niche occurring during ontogeny while, within age classes, differences among individuals were likely driven by trophic specialization. Each age class filled only a small portion of the total functional niche of the population and age classes occupied distinct portions in the functional space, indicating the existence of ontogenetic specialists with different functional roles within the population. The high amplitude of intraspecific variability in functional traits and differences in functional niche position among individuals reported here supports the recent claims for an individual-based approach in functional ecology. PMID:25558359

Herbivore removal reduces influence of arbuscular mycorrhizal fungi on plant growth and tolerance in an East African savanna.

PubMed

González, Jonathan B; Petipas, Renee H; Franken, Oscar; Kiers, E Toby; Veblen, Kari E; Brody, Alison K

2018-05-01

The functional relationship between arbuscular mycorrhizal fungi (AMF) and their hosts is variable on small spatial scales. Here, we hypothesized that herbivore exclusion changes the AMF community and alters the ability of AMF to enhance plant tolerance to grazing. We grew the perennial bunchgrass, Themeda triandra Forssk in inoculum from soils collected in the Kenya Long-term Exclosure Experiment where treatments representing different levels of herbivory have been in place since 1995. We assessed AMF diversity in the field, using terminal restriction fragment length polymorphism and compared fungal diversity among treatments. We conducted clipping experiments in the greenhouse and field and assessed regrowth. Plants inoculated with AMF from areas accessed by wild herbivores and cattle had greater biomass than non-inoculated controls, while plants inoculated with AMF from where large herbivores were excluded did not benefit from AMF in terms of biomass production. However, only the inoculation with AMF from areas with wild herbivores and no cattle had a positive effect on regrowth, relative to clipped plants grown without AMF. Similarly, in the field, regrowth of plants after clipping in areas with only native herbivores was higher than other treatments. Functional differences in AMF were evident despite little difference in AMF species richness or community composition. Our findings suggest that differences in large herbivore communities over nearly two decades has resulted in localized, functional changes in AMF communities. Our results add to the accumulating evidence that mycorrhizae are locally adapted and that functional differences can evolve within small geographical areas.

Output testing of small-arms primers

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Doris, Thomas A.; Schimmel, Morry L.

1991-01-01

The performance of two standard primers for initiating small-caliber ammunition are compared to that of a primer for initiating aircraft escape-system components. Three testing methods are employed including: (1) firing the primer to measure total energy delivered; (2) monitoring output in terms of gaseous product-mass flow rate and pressure as a function of time; and (3) firing the primer onto ignition material to study gas pressure produced during ignition and burning as a function of time. The results of the test demonstrate differences in the ignitability factors of the standard primers and time peak pressures of less than 100 microseconds. One unexpected result is that two percussion primers (the FA-41 and the M42C1) developed for different applications have the same ignitability. The ignitability test method is shown to yield the most useful data and can be used to specify percussion primers and optimize their performance.

Methodological approach for substantiating disease freedom in a heterogeneous small population. Application to ovine scrapie, a disease with a strong genetic susceptibility.

PubMed

Martinez, Marie-José; Durand, Benoit; Calavas, Didier; Ducrot, Christian

2010-06-01

Demonstrating disease freedom is becoming important in different fields including animal disease control. Most methods consider sampling only from a homogeneous population in which each animal has the same probability of becoming infected. In this paper, we propose a new methodology to calculate the probability of detecting the disease if it is present in a heterogeneous population of small size with potentially different risk groups, differences in risk being defined using relative risks. To calculate this probability, for each possible arrangement of the infected animals in the different groups, the probability that all the animals tested are test-negative given this arrangement is multiplied by the probability that this arrangement occurs. The probability formula is developed using the assumption of a perfect test and hypergeometric sampling for finite small size populations. The methodology is applied to scrapie, a disease affecting small ruminants and characterized in sheep by a strong genetic susceptibility defining different risk groups. It illustrates that the genotypes of the tested animals influence heavily the confidence level of detecting scrapie. The results present the statistical power for substantiating disease freedom in a small heterogeneous population as a function of the design prevalence, the structure of the sample tested, the structure of the herd and the associated relative risks. (c) 2010 Elsevier B.V. All rights reserved.

Pain neurophysiology education for the management of individuals with chronic low back pain: systematic review and meta-analysis.

PubMed

Clarke, Clare Louise; Ryan, Cormac Gerard; Martin, Denis J

2011-12-01

Pain neurophysiology education (PNE) is a form of education for patients with chronic low back pain (CLBP). The purpose of this systematic review was to investigate the evidence for PNE in the management of pateints with CLBP. A literature search of MEDLINE, CINAHL and AMED was performed from 1996(01)-2010(09). RCT appraisal and synthesis was assessed using the Cochrane Back Review Group (CBRG) guidelines. The main outcome measures were pain, physical-function, psychological-function, and social-function. Two moderate quality RCTs (n=122) were included in the final review. According to the CBRG criteria there was very low quality evidence that PNE is beneficial for pain, physical-function, psychological-function, and social-function. Meta-analysis found PNE produced statistically significant but clinically small improvements in short-term pain of 5mm (0, 10.0mm) [mean difference (95%CI)] on the 100mm VAS. This review was limited by the small number of studies (n=2) that met the inclusion criteria and by the fact that both studies were produced by the same group that published the PNE manual. These factors contributed to the relatively low grading of the evidence. There is a need for more studies investigating PNE by different research groups to support early promising findings. Until then firm clinical recommendations cannot be made. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pituitary gland volumes in bipolar disorder.

PubMed

Clark, Ian A; Mackay, Clare E; Goodwin, Guy M

2014-12-01

Bipolar disorder has been associated with increased Hypothalamic-Pituitary-Adrenal axis function. The mechanism is not well understood, but there may be associated increases in pituitary gland volume (PGV) and these small increases may be functionally significant. However, research investigating PGV in bipolar disorder reports mixed results. The aim of the current study was twofold. First, to assess PGV in two novel samples of patients with bipolar disorder and matched healthy controls. Second, to perform a meta-analysis comparing PGV across a larger sample of patients and matched controls. Sample 1 consisted of 23 established patients and 32 matched controls. Sample 2 consisted of 39 medication-naïve patients and 42 matched controls. PGV was measured on structural MRI scans. Seven further studies were identified comparing PGV between patients and matched controls (total n; 244 patients, 308 controls). Both novel samples showed a small (approximately 20mm(3) or 4%), but non-significant, increase in PGV in patients. Combining the two novel samples showed a significant association of age and PGV. Meta-analysis showed a trend towards a larger pituitary gland in patients (effect size: .23, CI: -.14, .59). While results suggest a possible small difference in pituitary gland volume between patients and matched controls, larger mega-analyses with sample sizes greater even than those used in the current meta-analysis are still required. There is a small but potentially functionally significant increase in PGV in patients with bipolar disorder compared to controls. Results demonstrate the difficulty of finding potentially important but small effects in functional brain disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

Recipient body surface area as a predictor of posttransplant renal allograft evolution.

PubMed

Moreso, F; Serón, D; Anunciada, A I; Hueso, M; Ramón, J M; Fulladosa, X; Gil-Vernet, S; Alsina, J; Grinyó, J M

1998-03-15

The aim of the present study was to analyze whether minor differences in recipient body surface area have any predictive value on renal allograft evolution. For this study, we considered 236 pairs of recipients who received a kidney from the same donor at our center between March 1985 and December 1995. Pairs in whom at least one patient presented any of the following events were excluded: graft loss during the first year of follow-up, diabetes mellitus, noncompliance with treatment, chronic pyelonephritis, and recurrent or de novo glomerulonephritis. Recipients of each pair were classified as large or small according to their body surface area (BSA). The percentage difference of BSA in each pair was calculated, and two cohorts of pairs were defined: BSA difference < or = 10% (n=76 pairs) and BSA difference >10% (n=70 pairs). The large recipients of the cohort with a BSA difference >10% showed a higher incidence of posttransplant delayed graft function (22/70 vs. 12/70, P=0.075), hypertension at 1 year of follow-up (51/70 vs. 35/70, P=0.006), and a higher serum creatinine level at 1-year follow-up (173 vs. 142 micromol/L, P=0.003), whereas in the cohort with a BSA difference < or = 10%, posttransplant evolution in large and small recipients was not different. Multivariate analysis showed that recipient BSA was an independent predictor of delayed graft function, posttransplant hypertension, and serum creatinine at 1-year follow-up. Relatively small differences in recipient BSA influence renal allograft evolution. Consequently, our data support that recipient size should be taken into consideration for renal allograft allocation.

Investigation of Super Learner Methodology on HIV-1 Small Sample: Application on Jaguar Trial Data.

PubMed

Houssaïni, Allal; Assoumou, Lambert; Marcelin, Anne Geneviève; Molina, Jean Michel; Calvez, Vincent; Flandre, Philippe

2012-01-01

Background. Many statistical models have been tested to predict phenotypic or virological response from genotypic data. A statistical framework called Super Learner has been introduced either to compare different methods/learners (discrete Super Learner) or to combine them in a Super Learner prediction method. Methods. The Jaguar trial is used to apply the Super Learner framework. The Jaguar study is an "add-on" trial comparing the efficacy of adding didanosine to an on-going failing regimen. Our aim was also to investigate the impact on the use of different cross-validation strategies and different loss functions. Four different repartitions between training set and validations set were tested through two loss functions. Six statistical methods were compared. We assess performance by evaluating R(2) values and accuracy by calculating the rates of patients being correctly classified. Results. Our results indicated that the more recent Super Learner methodology of building a new predictor based on a weighted combination of different methods/learners provided good performance. A simple linear model provided similar results to those of this new predictor. Slight discrepancy arises between the two loss functions investigated, and slight difference arises also between results based on cross-validated risks and results from full dataset. The Super Learner methodology and linear model provided around 80% of patients correctly classified. The difference between the lower and higher rates is around 10 percent. The number of mutations retained in different learners also varys from one to 41. Conclusions. The more recent Super Learner methodology combining the prediction of many learners provided good performance on our small dataset.

Brain Network Analysis from High-Resolution EEG Signals

NASA Astrophysics Data System (ADS)

de Vico Fallani, Fabrizio; Babiloni, Fabio

Over the last decade, there has been a growing interest in the detection of the functional connectivity in the brain from different neuroelectromagnetic and hemodynamic signals recorded by several neuro-imaging devices such as the functional Magnetic Resonance Imaging (fMRI) scanner, electroencephalography (EEG) and magnetoencephalography (MEG) apparatus. Many methods have been proposed and discussed in the literature with the aim of estimating the functional relationships among different cerebral structures. However, the necessity of an objective comprehension of the network composed by the functional links of different brain regions is assuming an essential role in the Neuroscience. Consequently, there is a wide interest in the development and validation of mathematical tools that are appropriate to spot significant features that could describe concisely the structure of the estimated cerebral networks. The extraction of salient characteristics from brain connectivity patterns is an open challenging topic, since often the estimated cerebral networks have a relative large size and complex structure. Recently, it was realized that the functional connectivity networks estimated from actual brain-imaging technologies (MEG, fMRI and EEG) can be analyzed by means of the graph theory. Since a graph is a mathematical representation of a network, which is essentially reduced to nodes and connections between them, the use of a theoretical graph approach seems relevant and useful as firstly demonstrated on a set of anatomical brain networks. In those studies, the authors have employed two characteristic measures, the average shortest path L and the clustering index C, to extract respectively the global and local properties of the network structure. They have found that anatomical brain networks exhibit many local connections (i.e. a high C) and few random long distance connections (i.e. a low L). These values identify a particular model that interpolate between a regular lattice and a random structure. Such a model has been designated as "small-world" network in analogy with the concept of the small-world phenomenon observed more than 30 years ago in social systems. In a similar way, many types of functional brain networks have been analyzed according to this mathematical approach. In particular, several studies based on different imaging techniques (fMRI, MEG and EEG) have found that the estimated functional networks showed small-world characteristics. In the functional brain connectivity context, these properties have been demonstrated to reflect an optimal architecture for the information processing and propagation among the involved cerebral structures. However, the performance of cognitive and motor tasks as well as the presence of neural diseases has been demonstrated to affect such a small-world topology, as revealed by the significant changes of L and C. Moreover, some functional brain networks have been mostly found to be very unlike the random graphs in their degree-distribution, which gives information about the allocation of the functional links within the connectivity pattern. It was demonstrated that the degree distributions of these networks follow a power-law trend. For this reason those networks are called "scale-free". They still exhibit the small-world phenomenon but tend to contain few nodes that act as highly connected "hubs". Scale-free networks are known to show resistance to failure, facility of synchronization and fast signal processing. Hence, it would be important to see whether the scaling properties of the functional brain networks are altered under various pathologies or experimental tasks. The present Chapter proposes a theoretical graph approach in order to evaluate the functional connectivity patterns obtained from high-resolution EEG signals. In this way, the "Brain Network Analysis" (in analogy with the Social Network Analysis that has emerged as a key technique in modern sociology) represents an effective methodology improving the comprehension of the complex interactions in the brain.

Dynamic studies of small animals with a four-color diffuse optical tomography imager

NASA Astrophysics Data System (ADS)

Schmitz, Christoph H.; Graber, Harry L.; Pei, Yaling; Farber, Mark; Stewart, Mark; Levina, Rita D.; Levin, Mikhail B.; Xu, Yong; Barbour, Randall L.

2005-09-01

We present newly developed instrumentation for full-tomographic four-wavelength, continuous wave, diffuse optical tomography (DOT) imaging on small animals. A small-animal imaging stage was constructed, from materials compatible with in-magnet studies, which offers stereotaxic fixation of the animal and precise, stable probe positioning. Instrument performance, based on calibration and phantom studies, demonstrates excellent long-term signal stability. DOT measurements of the functional rat brain response to electric paw stimulation are presented, and these demonstrate high data quality and excellent sensitivity to hemodynamic changes. A general linear model analysis on individual trials is used to localize and quantify the occurrence of functional behavior associated with the different hemoglobin state responses. Statistical evaluation of outcomes of individual trials is employed to identify significant regional response variations for different stimulation sites. Image results reveal a diffuse cortical response and a strong reaction of the thalamus, both indicative of activation of pain pathways by the stimulation. In addition, a weaker lateralized functional component is observed in the brain response, suggesting presence of motor activation. An important outcome of the experiment is that it shows that reactions to individual provocations can be monitored, without having to resort to signal averaging. Thus the described technology may be useful for studies of long-term trends in hemodynamic response, as would occur, for example, in behavioral studies involving freely moving animals.

Semi-inclusive deep inelastic scattering at small- x

NASA Astrophysics Data System (ADS)

Marquet, Cyrille; Xiao, Bo-Wen; Yuan, Feng

2009-11-01

We study the semi-inclusive hadron production in deep inelastic scattering at small-x. A transverse-momentum-dependent factorization is found consistent with the results calculated in the small-x approaches, such as the color-dipole framework and the color glass condensate, in the appropriate kinematic region at the lowest order. The transverse-momentum-dependent quark distribution can be studied in this process as a probe for the small-x saturation physics. Especially, the ratio of quark distributions as a function of transverse momentum at different x demonstrates strong dependence on the saturation scale. The Q2 dependence of the same ratio is also studied by applying the Collins-Soper-Sterman resummation method.

Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration

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

Djikaev, Y. S., E-mail: idjikaev@buffalo.edu; Ruckenstein, E.

2013-11-14

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 densitymore » 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.« less

Semi-inclusive Deep Inelastic Scattering at Small-x

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

Marquet, C.; Xiao, B.-W.; Yuan, Feng

We study the semi-inclusive hadron production in deep inelastic scattering at small-x.A transverse momentum dependent factorization is found consistent with the resultscalculated in the color-dipole framework in the appropriate kinematic region. The transverse momentum dependent quark distribution can be studied in this processas a probe for the small-x saturation physics. Especially, the ratio of the quark distributions as functions of transverse momentum at different x demonstrates strong dependence on the saturation scale. The Q2 dependence of the same ratio is also studied by applying the Collins-Soper-Sterman resummation method.

Oscillation characteristics of neutrino in the model with three sterile neutrinos for analysis of the anomalies on small distances

NASA Astrophysics Data System (ADS)

Khruschov, V. V.; Fomichev, S. V.

2017-11-01

In the framework of the model with three sterile neutrinos, the transition probabilities for different flavours of neutrino are calculated and the graphical dependences are obtained, in particular, for the appearance probability of electron neutrino and antineutrino in the muon neutrino and antineutrino jets as a function of distance and other model parameters at their acceptable values and at the neutrino energy less than 50 MeV, as well as a function of a ratio of distance to the neutrino energy. The theoretical results obtained can be used for analysis of the neutrino data related to the anomalies on small distances.

Evaluating gender similarities and differences using metasynthesis.

PubMed

Zell, Ethan; Krizan, Zlatan; Teeter, Sabrina R

2015-01-01

Despite the common lay assumption that males and females are profoundly different, Hyde (2005) used data from 46 meta-analyses to demonstrate that males and females are highly similar. Nonetheless, the gender similarities hypothesis has remained controversial. Since Hyde's provocative report, there has been an explosion of meta-analytic interest in psychological gender differences. We utilized this enormous collection of 106 meta-analyses and 386 individual meta-analytic effects to reevaluate the gender similarities hypothesis. Furthermore, we employed a novel data-analytic approach called metasynthesis (Zell & Krizan, 2014) to estimate the average difference between males and females and to explore moderators of gender differences. The average, absolute difference between males and females across domains was relatively small (d = 0.21, SD = 0.14), with the majority of effects being either small (46%) or very small (39%). Magnitude of differences fluctuated somewhat as a function of the psychological domain (e.g., cognitive variables, social and personality variables, well-being), but remained largely constant across age, culture, and generations. These findings provide compelling support for the gender similarities hypothesis, but also underscore conditions under which gender differences are most pronounced. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Passenger strand loading in overexpression experiments using microRNA mimics.

PubMed

Søkilde, Rolf; Newie, Inga; Persson, Helena; Borg, Åke; Rovira, Carlos

2015-01-01

MicroRNAs (miRNAs) are important regulators of gene function and manipulation of miRNAs is a central component of basic research. Modulation of gene expression by miRNA gain-of-function can be based on different approaches including transfection with miRNA mimics; artificial, chemically modified miRNA-like small RNAs. These molecules are intended to mimic the function of a miRNA guide strand while bypassing the maturation steps of endogenous miRNAs. Due to easy accessibility through commercial providers this approach has gained popularity, and accuracy is often assumed without prior independent testing. Our in silico analysis of over-represented sequence motifs in microarray expression data and sequencing of AGO-associated small RNAs indicate, however, that miRNA mimics may be associated with considerable side-effects due to the unwanted activity of the miRNA mimic complementary strand.

Vision-related quality of life and visual outcomes after small-incision lenticule extraction and laser in situ keratomileusis.

PubMed

Ang, Marcus; Ho, Henrietta; Fenwick, Eva; Lamoureux, Ecosse; Htoon, Hla M; Koh, Jane; Tan, Donald; Mehta, Jodhbir S

2015-10-01

To compare vision-related quality of life (VRQoL) scores and clinical outcomes between small-incision lenticule extraction and laser in situ keratomileusis (LASIK). Singapore National Eye Centre, Singapore. Prospective study. Patients had small-incision lenticule extraction using the Visumax 500 kHz femtosecond laser; or LASIK excimer ablation with the Wavelight Allegretto 400 Hz laser. Primary outcomes were 3-month predictability, efficacy, and safety. Secondary outcomes were intraoperative experience, visual symptoms, and VRQoL (validated Quality of Life Impact of Refractive Correction [QIRC] questionnaire) in 25 a subgroup of patients in each group. Following Rasch analysis, "Functional" and "Emotional," QIRC dimensions were analysed separately. At 3 months, predictability (82.5% versus 85.3%, ±0.5 diopters attempted correction, P =.453), safety index (1.13 ± 0.19 [SD] versus 1.07 ± 0.16, P = .158), and efficacy index (0.91 ± 0.21 versus 0.97 ± 0.19; P = .002) were found when comparing small-incision lenticule extraction (172 eyes) and LASIK (matched 688 eyes). Intraoperative experience between groups was not statistically different; visual fluctuations (P = .020) and episodes of visual blurring (P = .008) were greater after small-incision lenticule extraction than after LASIK at 1 month but not at 3 months. There was no difference in "functional" (66.7 ± 15.7 versus 55.3 ± 22.2, P = .064) and "emotional" (42.7 ± 23.2 versus 37.9 ± 23.8, P = .394) QIRC dimensions between the 2 groups (25 patients in each group) at 3 months. The study, 3-month predictability, safety, and VRQL scores were not statistically different between small-incision lenticule extraction and LASIK. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

College Student Drug Usage in a State System as a Function of Type of Institution

ERIC Educational Resources Information Center

Schoenfeldt, Lyle F.; Strimbu, Jerry L.

1975-01-01

Over 4,500 students from 28 universities, colleges, and junior colleges constituting a state system of higher education were compared on extent of drug use. The largest differences were between universities and junior colleges on alcohol and marihuana. Differences in terms of actual numbers of users were small. Implications are discussed.…

Density functional theory and chromium: Insights from the dimers

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

Würdemann, Rolf; Kristoffersen, Henrik H.; Moseler, Michael

2015-03-28

The binding in small Cr clusters is re-investigated, where the correct description of the dimer in three charge states is used as criterion to assign the most suitable density functional theory approximation. The difficulty in chromium arises from the subtle interplay between energy gain from hybridization and energetic cost due to exchange between s and d based molecular orbitals. Variations in published bond lengths and binding energies are shown to arise from insufficient numerical representation of electron density and Kohn-Sham wave-functions. The best functional performance is found for gradient corrected (GGA) functionals and meta-GGAs, where we find severe differences betweenmore » functionals from the same family due to the importance of exchange. Only the “best fit” from Bayesian error estimation is able to predict the correct energetics for all three charge states unambiguously. With this knowledge, we predict small bond-lengths to be exclusively present in Cr{sub 2} and Cr{sub 2}{sup −}. Already for the dimer cation, solely long bond-lengths appear, similar to what is found in the trimer and in chromium bulk.« less

Uniting functional network topology and oscillations in the fronto-parietal single unit network of behaving primates

PubMed Central

Dann, Benjamin; Michaels, Jonathan A; Schaffelhofer, Stefan; Scherberger, Hansjörg

2016-01-01

The functional communication of neurons in cortical networks underlies higher cognitive processes. Yet, little is known about the organization of the single neuron network or its relationship to the synchronization processes that are essential for its formation. Here, we show that the functional single neuron network of three fronto-parietal areas during active behavior of macaque monkeys is highly complex. The network was closely connected (small-world) and consisted of functional modules spanning these areas. Surprisingly, the importance of different neurons to the network was highly heterogeneous with a small number of neurons contributing strongly to the network function (hubs), which were in turn strongly inter-connected (rich-club). Examination of the network synchronization revealed that the identified rich-club consisted of neurons that were synchronized in the beta or low frequency range, whereas other neurons were mostly non-oscillatory synchronized. Therefore, oscillatory synchrony may be a central communication mechanism for highly organized functional spiking networks. DOI: http://dx.doi.org/10.7554/eLife.15719.001 PMID:27525488

Handedness- and brain size-related efficiency differences in small-world brain networks: a resting-state functional magnetic resonance imaging study.

PubMed

Li, Meiling; Wang, Junping; Liu, Feng; Chen, Heng; Lu, Fengmei; Wu, Guorong; Yu, Chunshui; Chen, Huafu

2015-05-01

The human brain has been described as a complex network, which integrates information with high efficiency. However, the relationships between the efficiency of human brain functional networks and handedness and brain size remain unclear. Twenty-one left-handed and 32 right-handed healthy subjects underwent a resting-state functional magnetic resonance imaging scan. The whole brain functional networks were constructed by thresholding Pearson correlation matrices of 90 cortical and subcortical regions. Graph theory-based methods were employed to further analyze their topological properties. As expected, all participants demonstrated small-world topology, suggesting a highly efficient topological structure. Furthermore, we found that smaller brains showed higher local efficiency, whereas larger brains showed higher global efficiency, reflecting a suitable efficiency balance between local specialization and global integration of brain functional activity. Compared with right-handers, significant alterations in nodal efficiency were revealed in left-handers, involving the anterior and median cingulate gyrus, middle temporal gyrus, angular gyrus, and amygdala. Our findings indicated that the functional network organization in the human brain was associated with handedness and brain size.

Wind noise spectra in small Reynolds number turbulent flows.

PubMed

Zhao, Sipei; Cheng, Eva; Qiu, Xiaojun; Burnett, Ian; Liu, Jacob Chia-Chun

2017-11-01

Wind noise spectra caused by wind from fans in indoor environments have been found to be different from those measured in outdoor atmospheric conditions. Although many models have been developed to predict outdoor wind noise spectra under the assumption of large Reynolds number [Zhao, Cheng, Qiu, Burnett, and Liu (2016). J. Acoust. Soc. Am. 140, 4178-4182, and the references therein], they cannot be applied directly to the indoor situations because the Reynolds number of wind from fans in indoor environments is usually much smaller than that experienced in atmospheric turbulence. This paper proposes a pressure structure function model that combines the energy-containing and dissipation ranges so that the pressure spectrum for small Reynolds number turbulent flows can be calculated. The proposed pressure structure function model is validated with the experimental results in the literature, and then the obtained pressure spectrum is verified with the numerical simulation and experiment results. It is demonstrated that the pressure spectrum obtained from the proposed pressure structure function model can be utilized to estimate wind noise spectra caused by turbulent flows with small Reynolds numbers.

Questionnaire-based assessment of executive functioning: Psychometrics.

PubMed

Castellanos, Irina; Kronenberger, William G; Pisoni, David B

2018-01-01

The psychometric properties of the Learning, Executive, and Attention Functioning (LEAF) scale were investigated in an outpatient clinical pediatric sample. As a part of clinical testing, the LEAF scale, which broadly measures neuropsychological abilities related to executive functioning and learning, was administered to parents of 118 children and adolescents referred for psychological testing at a pediatric psychology clinic; 85 teachers also completed LEAF scales to assess reliability across different raters and settings. Scores on neuropsychological tests of executive functioning and academic achievement were abstracted from charts. Psychometric analyses of the LEAF scale demonstrated satisfactory internal consistency, parent-teacher inter-rater reliability in the small to large effect size range, and test-retest reliability in the large effect size range, similar to values for other executive functioning checklists. Correlations between corresponding subscales on the LEAF and other behavior checklists were large, while most correlations with neuropsychological tests of executive functioning and achievement were significant but in the small to medium range. Results support the utility of the LEAF as a reliable and valid questionnaire-based assessment of delays and disturbances in executive functioning and learning. Applications and advantages of the LEAF and other questionnaire measures of executive functioning in clinical neuropsychology settings are discussed.

Origin of the monolayer Raman signature in hexagonal boron nitride: a first-principles analysis.

PubMed

Ontaneda, Jorge; Singh, Anjali; Waghmare, Umesh V; Grau-Crespo, Ricardo

2018-05-10

Monolayers of hexagonal boron nitride (h-BN) can in principle be identified by a Raman signature, consisting of an upshift in the frequency of the E 2g vibrational mode with respect to the bulk value, but the origin of this shift (intrinsic or support-induced) is still debated. Herein we use density functional theory calculations to investigate whether there is an intrinsic Raman shift in the h-BN monolayer in comparison with the bulk. There is universal agreement among all tested functionals in predicting the magnitude of the frequency shift upon a variation in the in-plane cell parameter. It is clear that a small in-plane contraction can explain the Raman peak upshift from bulk to monolayer. However, we show that the larger in-plane parameter in the bulk (compared to the monolayer) results from non-local correlation effects, which cannot be accounted for by local functionals or those with empirical dispersion corrections. Using a non-local-correlation functional, we then investigate the effect of finite temperatures on the Raman signature. We demonstrate that bulk h-BN thermally expands in the direction perpendicular to the layers, while the intralayer distances slightly contract, in agreement with observed experimental behavior. Interestingly, the difference in in-plane cell parameter between bulk and monolayer decreases with temperature, and becomes very small at room temperature. We conclude that the different thermal expansion of bulk and monolayer partially 'erases' the intrinsic Raman signature, accounting for its small magnitude in recent experiments on suspended samples.

Origin of the monolayer Raman signature in hexagonal boron nitride: a first-principles analysis

NASA Astrophysics Data System (ADS)

Ontaneda, Jorge; Singh, Anjali; Waghmare, Umesh V.; Grau-Crespo, Ricardo

2018-05-01

Monolayers of hexagonal boron nitride (h-BN) can in principle be identified by a Raman signature, consisting of an upshift in the frequency of the E2g vibrational mode with respect to the bulk value, but the origin of this shift (intrinsic or support-induced) is still debated. Herein we use density functional theory calculations to investigate whether there is an intrinsic Raman shift in the h-BN monolayer in comparison with the bulk. There is universal agreement among all tested functionals in predicting the magnitude of the frequency shift upon a variation in the in-plane cell parameter. It is clear that a small in-plane contraction can explain the Raman peak upshift from bulk to monolayer. However, we show that the larger in-plane parameter in the bulk (compared to the monolayer) results from non-local correlation effects, which cannot be accounted for by local functionals or those with empirical dispersion corrections. Using a non-local-correlation functional, we then investigate the effect of finite temperatures on the Raman signature. We demonstrate that bulk h-BN thermally expands in the direction perpendicular to the layers, while the intralayer distances slightly contract, in agreement with observed experimental behavior. Interestingly, the difference in in-plane cell parameter between bulk and monolayer decreases with temperature, and becomes very small at room temperature. We conclude that the different thermal expansion of bulk and monolayer partially ‘erases’ the intrinsic Raman signature, accounting for its small magnitude in recent experiments on suspended samples.

The cost of a small membrane bioreactor.

PubMed

Lo, C H; McAdam, E; Judd, S

2015-01-01

The individual cost contributions to the mechanical components of a small membrane bioreactor (MBR) (100-2,500 m3/d flow capacity) are itemised and collated to generate overall capital and operating costs (CAPEX and OPEX) as a function of size. The outcomes are compared to those from previously published detailed cost studies provided for both very small containerised plants (<40 m3/day capacity) and larger municipal plants (2,200-19,000 m3/d). Cost curves, as a function of flow capacity, determined for OPEX, CAPEX and net present value (NPV) based on the heuristic data used indicate a logarithmic function for OPEX and a power-based one for the CAPEX. OPEX correlations were in good quantitative agreement with those reported in the literature. Disparities in the calculated CAPEX trend compared with reported data were attributed to differences in assumptions concerning cost contributions. More reasonable agreement was obtained with the reported membrane separation component CAPEX data from published studies. The heuristic approach taken appears appropriate for small-scale MBRs with minimal costs associated with installation. An overall relationship of net present value=(a tb)Q(-c lnt+d) was determined for the net present value where a=1.265, b=0.44, c=0.00385 and d=0.868 according to the dataset employed for the analysis.

Peripheral neuropathic pain: a mechanism-related organizing principle based on sensory profiles

PubMed Central

Baron, Ralf; Maier, Christoph; Attal, Nadine; Binder, Andreas; Bouhassira, Didier; Cruccu, Giorgio; Finnerup, Nanna B.; Haanpää, Maija; Hansson, Per; Hüllemann, Philipp; Jensen, Troels S.; Freynhagen, Rainer; Kennedy, Jeffrey D.; Magerl, Walter; Mainka, Tina; Reimer, Maren; Rice, Andrew S.C.; Segerdahl, Märta; Serra, Jordi; Sindrup, Sören; Sommer, Claudia; Tölle, Thomas; Vollert, Jan; Treede, Rolf-Detlef

2016-01-01

Abstract Patients with neuropathic pain are heterogeneous in etiology, pathophysiology, and clinical appearance. They exhibit a variety of pain-related sensory symptoms and signs (sensory profile). Different sensory profiles might indicate different classes of neurobiological mechanisms, and hence subgroups with different sensory profiles might respond differently to treatment. The aim of the investigation was to identify subgroups in a large sample of patients with neuropathic pain using hypothesis-free statistical methods on the database of 3 large multinational research networks (German Research Network on Neuropathic Pain (DFNS), IMI-Europain, and Neuropain). Standardized quantitative sensory testing was used in 902 (test cohort) and 233 (validation cohort) patients with peripheral neuropathic pain of different etiologies. For subgrouping, we performed a cluster analysis using 13 quantitative sensory testing parameters. Three distinct subgroups with characteristic sensory profiles were identified and replicated. Cluster 1 (sensory loss, 42%) showed a loss of small and large fiber function in combination with paradoxical heat sensations. Cluster 2 (thermal hyperalgesia, 33%) was characterized by preserved sensory functions in combination with heat and cold hyperalgesia and mild dynamic mechanical allodynia. Cluster 3 (mechanical hyperalgesia, 24%) was characterized by a loss of small fiber function in combination with pinprick hyperalgesia and dynamic mechanical allodynia. All clusters occurred across etiologies but frequencies differed. We present a new approach of subgrouping patients with peripheral neuropathic pain of different etiologies according to intrinsic sensory profiles. These 3 profiles may be related to pathophysiological mechanisms and may be useful in clinical trial design to enrich the study population for treatment responders. PMID:27893485

Peripheral neuropathic pain: a mechanism-related organizing principle based on sensory profiles.

PubMed

Baron, Ralf; Maier, Christoph; Attal, Nadine; Binder, Andreas; Bouhassira, Didier; Cruccu, Giorgio; Finnerup, Nanna B; Haanpää, Maija; Hansson, Per; Hüllemann, Philipp; Jensen, Troels S; Freynhagen, Rainer; Kennedy, Jeffrey D; Magerl, Walter; Mainka, Tina; Reimer, Maren; Rice, Andrew S C; Segerdahl, Märta; Serra, Jordi; Sindrup, Sören; Sommer, Claudia; Tölle, Thomas; Vollert, Jan; Treede, Rolf-Detlef

2017-02-01

Patients with neuropathic pain are heterogeneous in etiology, pathophysiology, and clinical appearance. They exhibit a variety of pain-related sensory symptoms and signs (sensory profile). Different sensory profiles might indicate different classes of neurobiological mechanisms, and hence subgroups with different sensory profiles might respond differently to treatment. The aim of the investigation was to identify subgroups in a large sample of patients with neuropathic pain using hypothesis-free statistical methods on the database of 3 large multinational research networks (German Research Network on Neuropathic Pain (DFNS), IMI-Europain, and Neuropain). Standardized quantitative sensory testing was used in 902 (test cohort) and 233 (validation cohort) patients with peripheral neuropathic pain of different etiologies. For subgrouping, we performed a cluster analysis using 13 quantitative sensory testing parameters. Three distinct subgroups with characteristic sensory profiles were identified and replicated. Cluster 1 (sensory loss, 42%) showed a loss of small and large fiber function in combination with paradoxical heat sensations. Cluster 2 (thermal hyperalgesia, 33%) was characterized by preserved sensory functions in combination with heat and cold hyperalgesia and mild dynamic mechanical allodynia. Cluster 3 (mechanical hyperalgesia, 24%) was characterized by a loss of small fiber function in combination with pinprick hyperalgesia and dynamic mechanical allodynia. All clusters occurred across etiologies but frequencies differed. We present a new approach of subgrouping patients with peripheral neuropathic pain of different etiologies according to intrinsic sensory profiles. These 3 profiles may be related to pathophysiological mechanisms and may be useful in clinical trial design to enrich the study population for treatment responders.

Probing the Small-scale Structure in Strongly Lensed Systems via Transdimensional Inference

NASA Astrophysics Data System (ADS)

Daylan, Tansu; Cyr-Racine, Francis-Yan; Diaz Rivero, Ana; Dvorkin, Cora; Finkbeiner, Douglas P.

2018-02-01

Strong lensing is a sensitive probe of the small-scale density fluctuations in the Universe. We implement a pipeline to model strongly lensed systems using probabilistic cataloging, which is a transdimensional, hierarchical, and Bayesian framework to sample from a metamodel (union of models with different dimensionality) consistent with observed photon count maps. Probabilistic cataloging allows one to robustly characterize modeling covariances within and across lens models with different numbers of subhalos. Unlike traditional cataloging of subhalos, it does not require model subhalos to improve the goodness of fit above the detection threshold. Instead, it allows the exploitation of all information contained in the photon count maps—for instance, when constraining the subhalo mass function. We further show that, by not including these small subhalos in the lens model, fixed-dimensional inference methods can significantly mismodel the data. Using a simulated Hubble Space Telescope data set, we show that the subhalo mass function can be probed even when many subhalos in the sample catalogs are individually below the detection threshold and would be absent in a traditional catalog. The implemented software, Probabilistic Cataloger (PCAT) is made publicly available at https://github.com/tdaylan/pcat.

INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Influence of Blurred Ways on Pattern Recognition of a Scale-Free Hopfield Neural Network

NASA Astrophysics Data System (ADS)

Chang, Wen-Li

2010-01-01

We investigate the influence of blurred ways on pattern recognition of a Barabási-Albert scale-free Hopfield neural network (SFHN) with a small amount of errors. Pattern recognition is an important function of information processing in brain. Due to heterogeneous degree of scale-free network, different blurred ways have different influences on pattern recognition with same errors. Simulation shows that among partial recognition, the larger loading ratio (the number of patterns to average degree P/langlekrangle) is, the smaller the overlap of SFHN is. The influence of directed (large) way is largest and the directed (small) way is smallest while random way is intermediate between them. Under the ratio of the numbers of stored patterns to the size of the network P/N is less than 0. 1 conditions, there are three families curves of the overlap corresponding to directed (small), random and directed (large) blurred ways of patterns and these curves are not associated with the size of network and the number of patterns. This phenomenon only occurs in the SFHN. These conclusions are benefit for understanding the relation between neural network structure and brain function.

Emotion awareness and coping in children with functional abdominal pain: a controlled study.

PubMed

van der Veek, Shelley M C; Derkx, H H F; de Haan, Else; Benninga, Marc A; Boer, Frits

2012-01-01

Literature on somatization suggests that patients suffering from medically unexplained symptoms are less aware of their emotions and use maladaptive coping strategies when coping with everyday problems. In addition, coping is hypothesized to mediate between emotion awareness and medically unexplained symptoms. Scientific evidence for the relevance of this hypothesis for children with functional abdominal pain (FAP) is, however, lacking. Therefore, the purpose of the present study was to investigate this hypothesis in Dutch children with functional abdominal pain (FAP), aged 7-18 years. Between April 2007 and April 2010, a total of 114 referred children with FAP, 235 schoolchildren without abdominal pain and 407 schoolchildren with some abdominal pain (AP) of diverse etiology filled out questionnaires concerning their pain, emotion awareness and coping. MANOVA was used to investigate group differences in emotional awareness and coping. Structural equation modeling was used to investigate the mediational role of coping. The results showed that children with FAP scored significantly lower on most aspects of emotion awareness than children without AP, although these differences were small. Contrary to expectations, children with FAP were more aware of a link between emotions and bodily sensations than children without AP. As for coping, we found that children with FAP used avoidant coping more often than children without AP. Overall, children with FAP mostly did not differ in their emotional awareness and coping compared to children with some AP. Problem focused coping had a small mediating effect for two aspects of emotion awareness. We conclude that children with FAP show only small differences in emotion awareness and coping compared to children without AP, and are practically no different from children with some AP. Contrary to common belief, it can be questioned whether emotion awareness and general coping are useful targets for psychological treatments of FAP to focus on. Copyright © 2011 Elsevier Ltd. All rights reserved.

Polymer nanoparticles for drug and small silencing RNA delivery to treat cancers of different phenotypes

PubMed Central

Devulapally, Rammohan; Paulmurugan, Ramasamy

2013-01-01

Advances in nanotechnology have provided powerful and efficient tools in development of cancer diagnosis and therapy. There are numerous nanocarriers that are currently approved for clinical use in cancer therapy. In recent years, biodegradable polymer nanoparticles (NPs) have attracted a considerable attention for their ability to function as a possible carrier for target-specific delivery of various drugs, genes, proteins, peptides, vaccines, and other biomolecules in humans without much toxicity. This review will specifically focus on the recent advances in polymer-based nanocarriers for various drugs and small silencing RNA’s loading and delivery to treat different types of cancer. PMID:23996830

The role of the small airways in the pathophysiology of asthma and chronic obstructive pulmonary disease.

PubMed

Bonini, Matteo; Usmani, Omar S

2015-12-01

Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), represent a major social and economic burden for worldwide health systems. During recent years, increasing attention has been directed to the role of small airways in respiratory diseases, and their exact contribution to the pathophysiology of asthma and COPD continues to be clarified. Indeed, it has been suggested that small airways play a distinct role in specific disease phenotypes. Besides providing information on small airways structure and diagnostic procedures, this review therefore aims to present updated and evidence-based findings on the role of small airways in the pathophysiology of asthma and COPD. Most of the available information derives from either pathological studies or review articles and there are few data on the natural history of small airways disease in the onset or progression of asthma and COPD. Comparisons between studies on the role of small airways are hard to draw because both asthma and COPD are highly heterogeneous conditions. Most studies have been performed in small population samples, and different techniques to characterize aspects of small airways function have been employed in order to assess inflammation and remodelling. Most methods of assessing small airways dysfunction have been largely confined to research purposes, but some data are encouraging, supporting the utilization of certain techniques into daily clinical practice, particularly for early-stage diseases, when subjects are often asymptomatic and routine pulmonary function tests may be within normal ranges. In this context further clinical trials and real-life feedback on large populations are desirable. © The Author(s), 2015.

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control.

PubMed

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease.

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control

PubMed Central

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease. PMID:26870738

Design and integration of an all-in-one biomicrofluidic chip

PubMed Central

Liu, Liyu; Cao, Wenbin; Wu, Jingbo; Wen, Weijia; Chang, Donald Choy; Sheng, Ping

2008-01-01

We demonstrate a highly integrated microfluidic chip with the function of DNA amplification. The integrated chip combines giant electrorheological-fluid actuated micromixer and micropump with a microheater array, all formed using soft lithography. Internal functional components are based on polydimethylsiloxane (PDMS) and silver∕carbon black-PDMS composites. The system has the advantages of small size with a high degree of integration, high polymerase chain reaction efficiency, digital control and simple fabrication at low cost. This integration approach shows promise for a broad range of applications in chemical synthesis and biological sensing∕analysis, as different components can be combined to target desired functionalities, with flexible designs of different microchips easily realizable through soft lithography. PMID:19693370

Small vs. Large Convective Cloud Objects from CERES Aqua Observations: Where are the Intraseasonal Variation Signals?

NASA Technical Reports Server (NTRS)

Xu, Kuan-Man

2016-01-01

During inactive phases of Madden-Julian oscillation (MJO), there are plenty of deep but small convective systems and far fewer deep and large ones. During active phases of MJO, a manifestation of an increase in the occurrence of large and deep cloud clusters results from an amplification of large-scale motions by stronger convective heating. This study is designed to quantitatively examine the roles of small and large cloud clusters during the MJO life cycle. We analyze the cloud object data from Aqua CERES observations for tropical deep convective (DC) and cirrostratus (CS) cloud object types according to the real-time multivariate MJO index. The cloud object is a contiguous region of the earth with a single dominant cloud-system type. The size distributions, defined as the footprint numbers as a function of cloud object diameters, for particular MJO phases depart greatly from the combined (8-phase) distribution at large cloud-object diameters due to the reduced/increased numbers of cloud objects related to changes in the large-scale environments. The medium diameter corresponding to the combined distribution is determined and used to partition all cloud objects into "small" and "large" groups of a particular phase. The two groups corresponding to the combined distribution have nearly equal numbers of footprints. The medium diameters are 502 km for DC and 310 km for cirrostratus. The range of the variation between two extreme phases (typically, the most active and depressed phases) for the small group is 6-11% in terms of the numbers of cloud objects and the total footprint numbers. The corresponding range for the large group is 19-44%. In terms of the probability density functions of radiative and cloud physical properties, there are virtually no differences between the MJO phases for the small group, but there are significant differences for the large groups for both DC and CS types. These results suggest that the intreseasonal variation signals reside at the large cloud clusters while the small cloud clusters represent the background noises resulting from various types of the tropical waves with different wavenumbers and propagation directions/speeds.

Association between ethnicity and obesity with high-density lipoprotein (HDL) function and subclass distribution.

PubMed

Woudberg, Nicholas J; Goedecke, Julia H; Blackhurst, Dee; Frias, Miguel; James, Richard; Opie, Lionel H; Lecour, Sandrine

2016-05-11

Obesity and low high-density lipoprotein-cholesterol (HDL-C) levels are associated with cardiovascular risk. Surprisingly, despite a greater prevalence of obesity and lower HDL concentrations than white women, black South African women are relatively protected against ischaemic heart disease. We investigated whether this apparent discrepancy may be related to different HDL function and subclass distribution in black and white, normal-weight and obese South African women (n = 40). HDL functionality was assessed by measuring paraoxonase (PON) activity, platelet activating factor acetylhydrolase (PAF-AH) activity, Oxygen Radical Absorbance Capacity (ORAC) and quantification of the expression of vascular cell adhesion molecule in endothelial cells. PON-1 and PAF-AH expression was determined in isolated HDL and serum using Western blotting. Levels of large, intermediate and small HDL subclasses were measured using the Lipoprint® system. PON activity was lower in white compared to black women (0.49 ± 0.09 U/L vs 0.78 ± 0.10 U/L, p < 0.05), regardless of PON-1 protein levels. Obese black women had lower PAF-AH activity (9.34 ± 1.15 U/L vs 13.89 ± 1.21 U/L, p <0.05) and HDL-associated PAF-AH expression compared to obese white women. Compared to normal-weight women, obese women had lower large HDL, greater intermediate and small HDL; an effect that was more pronounced in white women than black women. There were no differences in antioxidant capacity or anti-inflammatory function across groups. Our data show that both obesity and ethnicity are associated with differences in HDL functionality, while obesity was associated with decreases in large HDL subclass distribution. Measuring HDL functionality and subclass may, therefore, be important factors to consider when assessing cardiovascular risk.

Brain Functional Connectivity in Small Cell Lung Cancer Population after Chemotherapy Treatment: an ICA fMRI Study

NASA Astrophysics Data System (ADS)

Bromis, K.; Kakkos, I.; Gkiatis, K.; Karanasiou, I. S.; Matsopoulos, G. K.

2017-11-01

Previous neurocognitive assessments in Small Cell Lung Cancer (SCLC) population, highlight the presence of neurocognitive impairments (mainly in attention processing and executive functioning) in this type of cancer. The majority of these studies, associate these deficits with the Prophylactic Cranial Irradiation (PCI) that patients undergo in order to avoid brain metastasis. However, there is not much evidence exploring cognitive impairments induced by chemotherapy in SCLC patients. For this reason, we aimed to investigate the underlying processes that may potentially affect cognition by examining brain functional connectivity in nineteen SCLC patients after chemotherapy treatment, while additionally including fourteen healthy participants as control group. Independent Component Analysis (ICA) is a functional connectivity measure aiming to unravel the temporal correlation between brain regions, which are called brain networks. We focused on two brain networks related to the aforementioned cognitive functions, the Default Mode Network (DMN) and the Task-Positive Network (TPN). Permutation tests were performed between the two groups to assess the differences and control for familywise errors in the statistical parametric maps. ICA analysis showed functional connectivity disruptions within both of the investigated networks. These results, propose a detrimental effect of chemotherapy on brain functioning in the SCLC population.

Modifications in small nuclear RNAs and their roles in spliceosome assembly and function.

PubMed

Bohnsack, Markus T; Sloan, Katherine E

2018-06-01

Modifications in cellular RNAs have emerged as key regulators of all aspects of gene expression, including pre-mRNA splicing. During spliceosome assembly and function, the small nuclear RNAs (snRNAs) form numerous dynamic RNA-RNA and RNA-protein interactions, which are required for spliceosome assembly, correct positioning of the spliceosome on substrate pre-mRNAs and catalysis. The human snRNAs contain several base methylations as well as a myriad of pseudouridines and 2'-O-methylated nucleotides, which are largely introduced by small Cajal body-specific-RNPs. Modified nucleotides typically cluster in functionally important regions of the snRNAs, suggesting that their presence could optimise the interactions of snRNAs with each other or with pre-mRNAs, or may affect the binding of spliceosomal proteins. snRNA modifications appear to play important roles in snRNP biogenesis and spliceosome assembly, and have also been proposed to influence the efficiency and fidelity of pre-mRNAs splicing. Interestingly, alterations in the modification status of snRNAs have recently been observed in different cellular conditions, implying that some snRNA modifications are dynamic and raising the possibility that these modifications may fine-tune the spliceosome for particular functions. Here, we review the current knowledge on the snRNA modification machinery and discuss the timing, functions and dynamics of modifications in snRNAs.

Energy flow and functional compensation in Great Basin small mammals under natural and anthropogenic environmental change

PubMed Central

Terry, Rebecca C.; Rowe, Rebecca J.

2015-01-01

Research on the ecological impacts of environmental change has primarily focused at the species level, leaving the responses of ecosystem-level properties like energy flow poorly understood. This is especially so over millennial timescales inaccessible to direct observation. Here we examine how energy flow within a Great Basin small mammal community responded to climate-driven environmental change during the past 12,800 y, and use this baseline to evaluate responses observed during the past century. Our analyses reveal marked stability in energy flow during rapid climatic warming at the terminal Pleistocene despite dramatic turnover in the distribution of mammalian body sizes and habitat-associated functional groups. Functional group turnover was strongly correlated with climate-driven changes in regional vegetation, with climate and vegetation change preceding energetic shifts in the small mammal community. In contrast, the past century has witnessed a substantial reduction in energy flow caused by an increase in energetic dominance of small-bodied species with an affinity for closed grass habitats. This suggests that modern changes in land cover caused by anthropogenic activities—particularly the spread of nonnative annual grasslands—has led to a breakdown in the compensatory dynamics of energy flow. Human activities are thus modifying the small mammal community in ways that differ from climate-driven expectations, resulting in an energetically novel ecosystem. Our study illustrates the need to integrate across ecological and temporal scales to provide robust insights for long-term conservation and management. PMID:26170294

Decision-making and cognitive abilities: A review of associations between Iowa Gambling Task performance, executive functions, and intelligence.

PubMed

Toplak, Maggie E; Sorge, Geoff B; Benoit, André; West, Richard F; Stanovich, Keith E

2010-07-01

The Iowa Gambling Task (IGT) has been used to study decision-making differences in many different clinical and developmental samples. It has been suggested that IGT performance captures abilities that are separable from cognitive abilities, including executive functions and intelligence. The purpose of the current review was to examine studies that have explicitly examined the relationship between IGT performance and these cognitive abilities. We included 43 studies that reported correlational analyses with IGT performance, including measures of inhibition, working memory, and set-shifting as indices of executive functions, as well as measures of verbal, nonverbal, and full-scale IQ as indices of intelligence. Overall, only a small proportion of the studies reported a statistically significant relationship between IGT performance and these cognitive abilities. The majority of studies reported a non-significant relationship. Of the minority of studies that reported statistically significant effects, effect sizes were, at best, small to modest, and confidence intervals were large, indicating that considerable variability in performance on the IGT is not captured by current measures of executive function and intelligence. These findings highlight the separability between decision-making on the IGT and cognitive abilities, which is consistent with recent conceptualizations that differentiate rationality from intelligence. 2010 Elsevier Ltd. All rights reserved.

Retinotopic patterns of functional connectivity between V1 and large-scale brain networks during resting fixation

PubMed Central

Griffis, Joseph C.; Elkhetali, Abdurahman S.; Burge, Wesley K.; Chen, Richard H.; Bowman, Anthony D.; Szaflarski, Jerzy P.; Visscher, Kristina M.

2016-01-01

Psychophysical and neurobiological evidence suggests that central and peripheral vision are specialized for different functions. This specialization of function might be expected to lead to differences in the large-scale functional interactions of early cortical areas that represent central and peripheral visual space. Here, we characterize differences in whole-brain functional connectivity among sectors in primary visual cortex (V1) corresponding to central, near-peripheral, and far-peripheral vision during resting fixation. Importantly, our analyses reveal that eccentricity sectors in V1 have different functional connectivity with non-visual areas associated with large-scale brain networks. Regions associated with the fronto-parietal control network are most strongly connected with central sectors of V1, regions associated with the cingulo-opercular control network are most strongly connected with near-peripheral sectors of V1, and regions associated with the default mode and auditory networks are most strongly connected with far-peripheral sectors of V1. Additional analyses suggest that similar patterns are present during eyes-closed rest. These results suggest that different types of visual information may be prioritized by large-scale brain networks with distinct functional profiles, and provide insights into how the small-scale functional specialization within early visual regions such as V1 relates to the large-scale organization of functionally distinct whole-brain networks. PMID:27554527

Burrowing by small polychaetes - mechanics, behavior and muscle structure of Capitella sp.

PubMed

Grill, Susann; Dorgan, Kelly M

2015-05-15

Worms of different sizes extend burrows through muddy sediments by fracture, applying dorso-ventral forces that are amplified at the crack tip. Smaller worms displace sediments less than larger worms and therefore are limited in how much force they can apply to burrow walls. We hypothesized that small worms would exhibit a transition in burrowing mechanics, specifically a lower limit in body size for the ability to burrow by fracture, corresponding with an ontogenetic transition in muscle morphology. Kinematics of burrowing in a mud analog, external morphology and muscle arrangement were examined in juveniles and adults of the small polychaete Capitella sp. We found that it moves by peristalsis, and no obvious differences were observed among worms of different sizes; even very small juveniles were able to burrow through a clear mud analog by fracture. Interestingly, we found that in addition to longitudinal and circular muscles needed for peristaltic movements, left- and right-handed helical muscles wrap around the thorax of worms of all sizes. We suggest that in small worms helical muscles may function to supplement forces generated by longitudinal muscles and to maintain hydrostatic pressure, enabling higher forces to be exerted on the crack wall. Further research is needed, however, to determine whether surficial sediments inhabited by small worms fail by fracture or plastically deform under forces of the magnitudes applied by Capitella sp. © 2015. Published by The Company of Biologists Ltd.

Electrical-pulse-induced resistivity modulation in Pt/TiO2-δ/Pt multilayer device related to nanoionics-based neuromorphic function

NASA Astrophysics Data System (ADS)

Kawamura, Kinya; Tsuchiya, Takashi; Takayanagi, Makoto; Terabe, Kazuya; Higuchi, Tohru

2017-06-01

Resistivity modulation behavior in Pt/TiO2-δ/Pt multilayer devices was investigated in terms of nanoionics-based neuromorphic function. The current relaxation behavior, which corresponds to short-term and long-term memorization in neuromorphic function, was analyzed using electrical pulses. In contrast to the huge difference in ionic conductivity for bulk crystal materials of TiO2-δ and WO3, the difference in the relaxation behavior was small. Rutherford backscattering spectrometry and hydrogen forward scattering spectrometry revealed that the TiO2-δ thin film contained 5.6 at. % of protons. This indicates that the neuromorphic function in TiO2-δ-based devices is caused by extrinsic proton transport, presumably through the grain boundary.

Does cognitive behavioural therapy for insomnia improve cognitive performance? A systematic review and narrative synthesis.

PubMed

Herbert, Vanessa; Kyle, Simon D; Pratt, Daniel

2018-06-01

Individuals with insomnia report difficulties pertaining to their cognitive functioning. Cognitive behavioural therapy for insomnia (CBT-I) is associated with robust, long-term improvements in sleep parameters, however less is known about the impact of CBT-I on the daytime correlates of the disorder. A systematic review and narrative synthesis was conducted in order to summarise and evaluate the evidence regarding the impact of CBT-I on cognitive functioning. Reference databases were searched and studies were included if they assessed cognitive performance as an outcome of CBT-I, using either self-report questionnaires or cognitive tests. Eighteen studies met inclusion criteria, comprising 923 individuals with insomnia symptoms. The standardised mean difference was calculated at post-intervention and follow-up. We found preliminary evidence for small to moderate effects of CBT-I on subjective measures of cognitive functioning. Few of the effects were statistically significant, likely due to small sample sizes and limited statistical power. There is a lack of evidence with regards to the impact of CBT-I on objective cognitive performance, primarily due to the small number of studies that administered an objective measure (n = 4). We conclude that adequately powered randomised controlled trials, utilising both subjective and objective measures of cognitive functioning are required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coastal flood implications of 1.5°C, 2°C and 2.5°C global mean temperature stabilization targets for small island nations

NASA Astrophysics Data System (ADS)

Rasmussen, D.; Buchanan, M. K.; Kopp, R. E.; Oppenheimer, M.

2017-12-01

Sea-level rise (SLR) is magnifying the frequency and severity of flooding in coastal regions. The rate and amount of global-mean SLR is a function of the trajectory of the global mean surface temperature (GMST). Therefore, temperature stabilization targets (e.g., 1.5°C or 2°C, as from the Paris Agreement) have important implications for regulating coastal flood risk. Quantifying the differences in the impact from SLR between these and other GMST stabilization targets is necessary for assessing the benefits and harms of mitigation goals. Low-lying small island nations are particularly vulnerable to inundation and coastal flooding from SLR because building protective and resilient infrastructure may not be physically or economically feasible. For small island nations, keeping GMST below a specified threshold may be the only option for maintaining habitability. Here, we assess differences in the return levels of coastal floods for small island nations between 1.5°C, 2.0°C, and 2.5°C GMST stabilization. We employ probabilistic, localized SLR projections and long-term hourly tide gauge records to construct estimates of local flood risk. We then estimate the number of small island nations' inhabitants at risk for permanent inundation under different GMST stabilization targets.

Branched terthiophenes in organic electronics: from small molecules to polymers.

PubMed

Scheuble, Martin; Goll, Miriam; Ludwigs, Sabine

2015-01-01

A zoo of chemical structures is accessible when the branched unit 2,2':3',2″-terthiophene (3T) is included both in structurally well-defined small molecules and polymer-like architectures. The first part of this review article highlights literature on all-thiophene based branched oligomers including dendrimers as well as combinations of 3T-units with functional moieties for light-harvesting systems. Motivated by the perfectly branched macromolecular dendrimers both electropolymerization as well as chemical approaches are presented as methods for the preparation of branched polythiophenes with different branching densities. Structure-function relationships between the molecular architecture and optical and electronic properties are discussed throughout the article. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Forward multiple scattering corrections as function of detector field of view

NASA Astrophysics Data System (ADS)

Zardecki, A.; Deepak, A.

1983-06-01

The theoretical formulations are given for an approximate method based on the solution of the radiative transfer equation in the small angle approximation. The method is approximate in the sense that an approximation is made in addition to the small angle approximation. Numerical results were obtained for multiple scattering effects as functions of the detector field of view, as well as the size of the detector's aperture for three different values of the optical depth tau (=1.0, 4.0 and 10.0). Three cases of aperture size were considered--namely, equal to or smaller or larger than the laser beam diameter. The contrast between the on-axis intensity and the received power for the last three cases is clearly evident.

[Changes in the peritoneum of the small intestine and diaphragm in experimental portal hypertension].

PubMed

Khoroshaev, V A; Vorozheĭkin, V M; Baĭbekov, I M

1991-04-01

Diaphragm and small intestine peritoneum morphology was studied in experimental portal hypertension in rats with the help of luminescent, transmission and scanning electron microscopy techniques. Structural organizations of these peritoneum portions and performance function were different: fluid transudation realized through the small intestine peritoneum and resorption occurred via diaphragm peritoneum. Morphological signs allowed to judge about the increasing of fluid transudation in abdominal cavity and diaphragmatic resorption in early period of portal hypertension. Morphological alterations appeared in peritoneum resorption sites (pumping diaphragmatic hatchs) according to progress of portal hypertension that indicated decompensation process of peritoneal fluid absorption and led to ascites.

Fetal growth, cognitive function, and brain volumes in childhood and adolescence.

PubMed

Rogne, Tormod; Engstrøm, Andreas Aass; Jacobsen, Geir Wenberg; Skranes, Jon; Østgård, Heidi Furre; Martinussen, Marit

2015-03-01

To evaluate the association between fetal growth pattern and cognitive function at 5 and 9 years and regional brain volumes at 15 years. Eighty-three term-born small-for-gestational-age (SGA) neonates and 105 non-SGA neonates in a control group were available for follow-up. Based on serial fetal ultrasound measurements from gestational weeks 25-37, SGA neonates were classified with fetal growth restriction (n=13) or non-fetal growth restriction (n=36). Cognitive function was assessed at 5 and 9 years, and brain volumes were estimated with cerebral magnetic resonance imaging at 15 years. Small-for-gestational-age children had lower performance intelligence quotient at 5 years compared with those in a control group (107.3 compared with 112.5, P<.05). Although there were no differences between the SGA non-fetal growth restriction and control groups, the SGA fetal growth restriction group had significantly lower performance intelligence quotient at 5 years (103.5 compared with 112.5, P<.05) and 9 years (96.2 compared with 107.5, P<.05) compared with those in the control group. There were some brain volume differences at 15 years between SGA children and those in the control group, but after adjustment for total intracranial volume, age at examination, and sex, there were only significant differences between the SGA fetal growth restriction and control groups for thalamic (17.4 compared with 18.6 cm, P<.01) and cerebellar white matter volumes (21.5 compared with 24.3 cm, P<.01). Small-for-gestational-age children had lower intelligence quotient scores at 5 and 9 years and smaller brain volumes at 15 years compared with those in the control group, but these findings were only found in those with fetal growth restriction, indicating a possible relationship to decelerated fetal growth. II.

Noninvasively measuring oxygen saturation of human finger-joint vessels by multi-transducer functional photoacoustic tomography

NASA Astrophysics Data System (ADS)

Deng, Zijian; Li, Changhui

2016-06-01

Imaging small blood vessels and measuring their functional information in finger joint are still challenges for clinical imaging modalities. In this study, we developed a multi-transducer functional photoacoustic tomography (PAT) system and successfully imaged human finger-joint vessels from ˜1 mm to <0.2 mm in diameter. In addition, the oxygen saturation (SO2) values of these vessels were also measured. Our results demonstrate that PAT can provide both anatomical and functional information of individual finger-joint vessels with different sizes, which might help the study of finger-joint diseases, such as rheumatoid arthritis.

Microplates with adaptive surfaces.

PubMed

Akbulut, Meshude; Lakshmi, Dhana; Whitcombe, Michael J; Piletska, Elena V; Chianella, Iva; Güven, Olgun; Piletsky, Sergey A

2011-11-14

Here we present a new and versatile method for the modification of the well surfaces of polystyrene microtiter plates (microplates) with poly(N-phenylethylene diamine methacrylamide), (poly-NPEDMA). The chemical grafting of poly-NPEDMA to the surface of microplates resulted in the formation of thin layers of a polyaniline derivative bearing pendant methacrylamide double bonds. These were used as the attachment point for various functional polymers through photochemical grafting of various, for example, acrylate and methacrylate, polymers with different functionalities. In a model experiment, we have modified poly-NPEDMA-coated microplates with a small library of polymers containing different functional groups using a two-step approach. In the first step, double bonds were activated by UV irradiation in the presence of N,N-diethyldithiocarbamic acid benzyl ester (iniferter). This enabled grafting of the polymer library in the second step by UV irradiation of solutions of the corresponding monomers in the microplate wells. The uniformity of coatings was confirmed spectrophotometrically, by microscopic imaging and by contact angle measurements (CA). The feasibility of the current technology has been shown by the generation of a small library of polymers grafted to the microplate well surfaces and screening of their affinity to small molecules, such as atrazine, a trio of organic dyes, and a model protein, bovine serum albumin (BSA). The stability of the polymers, reproducibility of measurement, ease of preparation, and cost-effectiveness make this approach suitable for applications in high-throughput screening in the area of materials research.

Late outcomes of a randomized trial of high-frequency oscillation in neonates.

PubMed

Zivanovic, Sanja; Peacock, Janet; Alcazar-Paris, Mireia; Lo, Jessica W; Lunt, Alan; Marlow, Neil; Calvert, Sandy; Greenough, Anne

2014-03-20

Results from an observational study involving neonates suggested that high-frequency oscillatory ventilation (HFOV), as compared with conventional ventilation, was associated with superior small-airway function at follow-up. Data from randomized trials are needed to confirm this finding. We studied 319 adolescents who had been born before 29 weeks of gestation and had been enrolled in a multicenter, randomized trial that compared HFOV with conventional ventilation immediately after birth. The trial involved 797 neonates, of whom 592 survived to hospital discharge. We compared follow-up data from adolescents who had been randomly assigned to HFOV with follow-up data from those who had been randomly assigned to conventional ventilation, with respect to lung function and respiratory health, health-related quality of life, and functional status, as assessed with the use of questionnaires completed when the participants were 11 to 14 years of age. The primary outcome was forced expiratory flow at 75% of the expired vital capacity (FEF75). The HFOV group had superior results on a test of small-airway function (z score for FEF75, -0.97 with HFOV vs. -1.19 with conventional therapy; adjusted difference, 0.23 [95% confidence interval, 0.02 to 0.45]). There were significant differences in favor of HFOV in several other measures of respiratory function, including forced expiratory volume in 1 second, forced vital capacity, peak expiratory flow, diffusing capacity, and impulse-oscillometric findings. As compared with the conventional-therapy group, the HFOV group had significantly higher ratings from teachers in three of eight school subjects assessed, but there were no other significant differences in functional outcomes. In a randomized trial involving children who had been born extremely prematurely, those who had undergone HFOV, as compared with those who had received conventional ventilation, had superior lung function at 11 to 14 years of age, with no evidence of poorer functional outcomes. (Funded by the National Institute for Health Research Health Technology Assessment Programme and others.).

Two decades of climate driving the dynamics of functional and taxonomic diversity of a tropical small mammal community in western Mexico

PubMed Central

2017-01-01

Understanding the effects of global climate disruption on biodiversity is important to future conservation efforts. While taxonomic diversity is widely studied, functional diversity of plants, and recently animals, is receiving increasing attention. Most studies of mammals are short-term, focus on temperate habitats, and rely on traits described in the literature rather than generating traits from observations. Unlike previous studies, this long-term field study assessed the factors driving the functional and taxonomic diversity of small-mammal assemblages in dry tropical forests using both traits recorded from literature and a demographic database. We assessed the drivers (abundance and biomass, temperature and rainfall) of taxonomic richness and functional diversity for two rain-driven seasons in two adjacent but distinct forests—upland and lowland (arroyo or riparian) forests. Our analysis found that rainfall, both seasonal and atypical, was the primary factor driving functional and taxonomic diversity of small-mammal assemblages. Functional responses differed between the two types of forests, however, with effects being stronger in the harsher conditions of the upland forests than in the less severe conditions prevailing in the arroyo (riparian) forest. The latter also supports a richer, more diverse, and more stable small-mammal assemblage. These findings highlight the importance of climate to tropical biological diversity, as extreme climate events (hurricanes, droughts and floods) and disruption of rainfall patterns were shown to decrease biodiversity. They also support the need to preserve these habitats, as their high taxonomic diversity and functional redundancy makes them resilient against global climate disruption and local extreme events. Tropical dry forests constitute a potential reservoir for biodiversity and the ecosystem services they provide. Unfortunately, these forests are among the most endangered terrestrial ecosystems because of deforestation and the likely impacts of global climate disruption. PMID:29228017

DNA methylation profiles distinguish different subtypes of gastroenteropancreatic neuroendocrine tumors.

PubMed

How-Kit, Alexandre; Dejeux, Emelyne; Dousset, Bertrand; Renault, Victor; Baudry, Marion; Terris, Benoit; Tost, Jörg

2015-01-01

Most studies have considered gastroenteropancreatic neuroendocrine tumors (GEP-NETs) as a homogenous group of samples or distinguish only gastrointestinal from pancreatic endocrine tumors. This article investigates if DNA methylation patterns could distinguish subtypes of GEP-NETs. The DNA methylation level of 807 cancer-related genes was investigated in insulinomas, gastrinomas, non-functioning pancreatic endocrine tumors and small intestine endocrine tumors. DNA methylation patterns were found to be tumor type specific for each of the pancreatic tumor subtypes and identified two distinct methylation-based groups in small intestine endocrine tumors. Differences of DNA methylation levels were validated by pyrosequencing for 20 candidate genes and correlated with differences at the transcriptional level for four candidate genes. The heterogeneity of DNA methylation patterns in the different subtypes of gastroenteropancreatic neuroendocrine tumors suggests different underlying pathways and, therefore, these tumors should be considered as distinct entities in molecular and clinical studies.

Solid harmonic wavelet scattering for predictions of molecule properties

NASA Astrophysics Data System (ADS)

Eickenberg, Michael; Exarchakis, Georgios; Hirn, Matthew; Mallat, Stéphane; Thiry, Louis

2018-06-01

We present a machine learning algorithm for the prediction of molecule properties inspired by ideas from density functional theory (DFT). Using Gaussian-type orbital functions, we create surrogate electronic densities of the molecule from which we compute invariant "solid harmonic scattering coefficients" that account for different types of interactions at different scales. Multilinear regressions of various physical properties of molecules are computed from these invariant coefficients. Numerical experiments show that these regressions have near state-of-the-art performance, even with relatively few training examples. Predictions over small sets of scattering coefficients can reach a DFT precision while being interpretable.

Disappearance of Anisotropic Intermittency in Large-amplitude MHD Turbulence and Its Comparison with Small-amplitude MHD Turbulence

NASA Astrophysics Data System (ADS)

Yang, Liping; Zhang, Lei; He, Jiansen; Tu, Chuanyi; Li, Shengtai; Wang, Xin; Wang, Linghua

2018-03-01

Multi-order structure functions in the solar wind are reported to display a monofractal scaling when sampled parallel to the local magnetic field and a multifractal scaling when measured perpendicularly. Whether and to what extent will the scaling anisotropy be weakened by the enhancement of turbulence amplitude relative to the background magnetic strength? In this study, based on two runs of the magnetohydrodynamic (MHD) turbulence simulation with different relative levels of turbulence amplitude, we investigate and compare the scaling of multi-order magnetic structure functions and magnetic probability distribution functions (PDFs) as well as their dependence on the direction of the local field. The numerical results show that for the case of large-amplitude MHD turbulence, the multi-order structure functions display a multifractal scaling at all angles to the local magnetic field, with PDFs deviating significantly from the Gaussian distribution and a flatness larger than 3 at all angles. In contrast, for the case of small-amplitude MHD turbulence, the multi-order structure functions and PDFs have different features in the quasi-parallel and quasi-perpendicular directions: a monofractal scaling and Gaussian-like distribution in the former, and a conversion of a monofractal scaling and Gaussian-like distribution into a multifractal scaling and non-Gaussian tail distribution in the latter. These results hint that when intermittencies are abundant and intense, the multifractal scaling in the structure functions can appear even if it is in the quasi-parallel direction; otherwise, the monofractal scaling in the structure functions remains even if it is in the quasi-perpendicular direction.

Differences in macroinvertebrate community structure in streams and rivers with different hydrologic regimes in the semi-arid Colorado Plateau

USGS Publications Warehouse

Miller, Matthew P.; Brasher, Anne M.D.

2011-01-01

Aquatic macroinvertebrates are sensitive to changes in their chemical and physical environment, and as such, serve as excellent indicators of overall ecosystem health. Moreover, temporal and spatial differences in macroinvertebrate community structure can be used to investigate broad issues in aquatic science, such as the hypothesis that changes in climate are likely to have disproportionately large effects on small, intermittent stream ecosystems. We quantified macroinvertebrate community structure and abiotic conditions at ten stream sites with different dominant hydrologic regimes in the Colorado Plateau, ranging from small, intermittent desert streams to large perennial mountain rivers. Considerable differences were observed in community structure between sites with differing hydrologic regimes. Quantitative results of non-metric multidimensional scaling (NMDS) ordination and Spearman rank correlations between physical habitat and macroinvertebrate resemblance matrices indicate that discharge, geomorphic channel unit type (% pools vs. % riffles), percent of substrate composed of sand, and velocity were the subset of measured habitat variables that best explained the differences in macroinvertebrate community structure among sites. Of the 134 taxa identified, nine taxa explained 95 % of the variability in community structure between sites. These results add to a growing base of knowledge regarding the functioning of lotic ecosystems in the Colorado Plateau, and provide timely information on anticipated changes in the structure and function of aquatic ecosystems in response to predicted future environmental conditions.

Integrating small mammal community variables into aircraft-wildlife collision management plans at Namibian airports.

PubMed

Hauptfleisch, Morgan L; Avenant, Nico L

2015-11-01

Understanding ecosystems within and around airports can help to determine the causes and possible mitigation measures for collisions between aircraft and wildlife. Small mammal communities are an important component of the semi-arid savanna ecosystems of Namibia, its productivity and its ecosystem integrity. They are also a major direct attractant for raptors at airports. The present study compared the abundance and diversity of small mammals between Namibia's 2 main airport properties (Hosea Kutako International Airport and Eros Airport), and among areas of land used for various purposes surrounding the airports. A total of 2150 small mammals (3 orders, 11 species) were captured over 4 trapping seasons. Small mammal abundance was significantly higher at the end of the growing season than during the non-growing season. The grass mowing regimen in current management plans at the airports resulted in a significant reduction of small mammal abundance at Hosea Kutako during the non-growing season only, thus indicating that annual mowing is effective but insufficient to reduce the overall abundance of mammal prey species for raptors. Small mammal numbers were significantly higher at Hosea Kutako Airport compared to the cattle and game farming land surrounding the airport, while no differences in small mammal densities or diversity were found for areas with different land uses at and surrounding Eros. The study suggests that the fence around Hosea Kutako provides a refuge for small mammals, resulting in higher densities. It also indicates that different surrounding land use practices result in altered ecosystem function and productivity, an important consideration when identifying wildlife attractants at airports. © 2015 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Identification of small RNAs in extracellular vesicles from the commensal yeast Malassezia sympodialis.

PubMed

Rayner, Simon; Bruhn, Sören; Vallhov, Helen; Andersson, Anna; Billmyre, R Blake; Scheynius, Annika

2017-01-04

Malassezia is the dominant fungus in the human skin mycobiome and is associated with common skin disorders including atopic eczema (AE)/dermatitis. Recently, it was found that Malassezia sympodialis secretes nanosized exosome-like vesicles, designated MalaEx, that carry allergens and can induce inflammatory cytokine responses. Extracellular vesicles from different cell-types including fungi have been found to deliver functional RNAs to recipient cells. In this study we assessed the presence of small RNAs in MalaEx and addressed if the levels of these RNAs differ when M. sympodialis is cultured at normal human skin pH versus the elevated pH present on the skin of patients with AE. The total number and the protein concentration of the released MalaEx harvested after 48 h culture did not differ significantly between the two pH conditions nor did the size of the vesicles. From small RNA sequence data, we identified a set of reads with well-defined start and stop positions, in a length range of 16 to 22 nucleotides consistently present in the MalaEx. The levels of small RNAs were not significantly differentially expressed between the two different pH conditions indicating that they are not influenced by the elevated pH level observed on the AE skin.

Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

PubMed Central

Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

2015-01-01

Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

PubMed Central

Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

2013-01-01

The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

Monte Carlo-based evaluation of S-values in mouse models for positron-emitting radionuclides

NASA Astrophysics Data System (ADS)

Xie, Tianwu; Zaidi, Habib

2013-01-01

In addition to being a powerful clinical tool, Positron emission tomography (PET) is also used in small laboratory animal research to visualize and track certain molecular processes associated with diseases such as cancer, heart disease and neurological disorders in living small animal models of disease. However, dosimetric characteristics in small animal PET imaging are usually overlooked, though the radiation dose may not be negligible. In this work, we constructed 17 mouse models of different body mass and size based on the realistic four-dimensional MOBY mouse model. Particle (photons, electrons and positrons) transport using the Monte Carlo method was performed to calculate the absorbed fractions and S-values for eight positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Y-86 and I-124). Among these radionuclides, O-15 emits positrons with high energy and frequency and produces the highest self-absorbed S-values in each organ, while Y-86 emits γ-rays with high energy and frequency which results in the highest cross-absorbed S-values for non-neighbouring organs. Differences between S-values for self-irradiated organs were between 2% and 3%/g difference in body weight for most organs. For organs irradiating other organs outside the splanchnocoele (i.e. brain, testis and bladder), differences between S-values were lower than 1%/g. These appealing results can be used to assess variations in small animal dosimetry as a function of total-body mass. The generated database of S-values for various radionuclides can be used in the assessment of radiation dose to mice from different radiotracers in small animal PET experiments, thus offering quantitative figures for comparative dosimetry research in small animal models.

A study of the luminosity function for field galaxies. [non-rich-cluster galaxies

NASA Technical Reports Server (NTRS)

Felten, J. E.

1977-01-01

Nine determinations of the luminosity function (LF) for field galaxies are analyzed and compared. Corrections for differences in Hubble constants, magnitude systems, galactic absorption functions, and definitions of the LF are necessary prior to comparison. Errors in previous comparisons are pointed out. After these corrections, eight of the nine determinations are in fairly good agreement. The discrepancy in the ninth appears to be mainly an incompleteness effect. The LF data suggest that there is little if any distinction between field galaxies and those in small groups.

Measurements of the Temperature Structure-Function Parameters with a Small Unmanned Aerial System Compared with a Sodar

NASA Astrophysics Data System (ADS)

Bonin, Timothy A.; Goines, David C.; Scott, Aaron K.; Wainwright, Charlotte E.; Gibbs, Jeremy A.; Chilson, Phillip B.

2015-06-01

The structure function is often used to quantify the intensity of spatial inhomogeneities within turbulent flows. Here, the Small Multifunction Research and Teaching Sonde (SMARTSonde), an unmanned aerial system, is used to measure horizontal variations in temperature and to calculate the structure function of temperature at various heights for a range of separation distances. A method for correcting for the advection of turbulence in the calculation of the structure function is discussed. This advection correction improves the data quality, particularly when wind speeds are high. The temperature structure-function parameter can be calculated from the structure function of temperature. Two case studies from which the SMARTSonde was able to take measurements used to derive at several heights during multiple consecutive flights are discussed and compared with sodar measurements, from which is directly related to return power. Profiles of from both the sodar and SMARTSonde from an afternoon case exhibited generally good agreement. However, the profiles agreed poorly for a morning case. The discrepancies are partially attributed to different averaging times for the two instruments in a rapidly evolving environment, and the measurement errors associated with the SMARTSonde sampling within the stable boundary layer.

Evolution of High Mobility Group Nucleosome-Binding Proteins and Its Implications for Vertebrate Chromatin Specialization

PubMed Central

González-Romero, Rodrigo; Eirín-López, José M.; Ausió, Juan

2015-01-01

High mobility group (HMG)-N proteins are a family of small nonhistone proteins that bind to nucleosomes (N). Despite the amount of information available on their structure and function, there is an almost complete lack of information on the molecular evolutionary mechanisms leading to their exclusive differentiation. In the present work, we provide evidence suggesting that HMGN lineages constitute independent monophyletic groups derived from a common ancestor prior to the diversification of vertebrates. Based on observations of the functional diversification across vertebrate HMGN proteins and on the extensive silent nucleotide divergence, our results suggest that the long-term evolution of HMGNs occurs under strong purifying selection, resulting from the lineage-specific functional constraints of their different protein domains. Selection analyses on independent lineages suggest that their functional specialization was mediated by bursts of adaptive selection at specific evolutionary times, in a small subset of codons with functional relevance—most notably in HMGN1, and in the rapidly evolving HMGN5. This work provides useful information to our understanding of the specialization imparted on chromatin metabolism by HMGNs, especially on the evolutionary mechanisms underlying their functional differentiation in vertebrates. PMID:25281808

Alterations in the small intestinal wall and motor function after repeated cisplatin in rat.

PubMed

Uranga, J A; García-Martínez, J M; García-Jiménez, C; Vera, G; Martín-Fontelles, M I; Abalo, R

2017-07-01

Gastrointestinal adverse effects occurring during cancer chemotherapy are well known and feared; those persisting once treatment has finished are relatively unknown. We characterized the alterations occurring in the rat small intestine, after repeated treatment with cisplatin. Male Wistar rats received saline or cisplatin (2 mg kg -1  week -1 , for 5 weeks, ip). Gastric motor function was studied non-invasively throughout treatment (W1-W5) and 1 week after treatment finalization (W6). During W6, upper gastrointestinal motility was also invasively studied and small intestinal samples were collected for histopathological and molecular studies. Structural alterations in the small intestinal wall, mucosa, submucosa, muscle layers, and lymphocytic nodules were histologically studied. Periodic acid-Schiff staining and immunohistochemistry for Ki-67, chromogranin A, and neuronal-specific enolase were used to detect secretory, proliferating, endocrine and neural cells, respectively. The expression of different markers in the tunica muscularis was analyzed by RT/qPCR. Repeated cisplatin induced motility alterations during and after treatment. After treatment (W6), the small intestinal wall showed histopathological alterations in most parameters measured, including a reduction in the thickness of circular and longitudinal muscle layers. Expression of c-KIT (for interstitial cells of Cajal), nNOS (for inhibitory motor neurons), pChAT, and cChAT (for excitatory motor neurons) increased significantly (although both ChATs to a lesser extent). Repeated cisplatin induces relatively long-lasting gut dysmotility in rat associated with important histopathological and molecular alterations in the small intestinal wall. In cancer survivors, the possible chemotherapy-induced histopathological, molecular, and functional intestinal sequelae should be evaluated. © 2017 John Wiley & Sons Ltd.

Simple Analytic Formula for the Period of the Nonlinear Pendulum via the Struve Function: Connection to Acoustical Impedance Matching

ERIC Educational Resources Information Center

Douvropoulos, Theodosios G.

2012-01-01

An approximate formula for the period of pendulum motion beyond the small amplitude regime is obtained based on physical arguments. Two different schemes of different accuracy are developed: in the first less accurate scheme, emphasis is given on the non-quadratic form of the potential in connection to isochronism, and a specific form of a generic…

The relative efficiency of modular and non-modular networks of different size

PubMed Central

Tosh, Colin R.; McNally, Luke

2015-01-01

Most biological networks are modular but previous work with small model networks has indicated that modularity does not necessarily lead to increased functional efficiency. Most biological networks are large, however, and here we examine the relative functional efficiency of modular and non-modular neural networks at a range of sizes. We conduct a detailed analysis of efficiency in networks of two size classes: ‘small’ and ‘large’, and a less detailed analysis across a range of network sizes. The former analysis reveals that while the modular network is less efficient than one of the two non-modular networks considered when networks are small, it is usually equally or more efficient than both non-modular networks when networks are large. The latter analysis shows that in networks of small to intermediate size, modular networks are much more efficient that non-modular networks of the same (low) connective density. If connective density must be kept low to reduce energy needs for example, this could promote modularity. We have shown how relative functionality/performance scales with network size, but the precise nature of evolutionary relationship between network size and prevalence of modularity will depend on the costs of connectivity. PMID:25631996

A versatile test for equality of two survival functions based on weighted differences of Kaplan-Meier curves.

PubMed

Uno, Hajime; Tian, Lu; Claggett, Brian; Wei, L J

2015-12-10

With censored event time observations, the logrank test is the most popular tool for testing the equality of two underlying survival distributions. Although this test is asymptotically distribution free, it may not be powerful when the proportional hazards assumption is violated. Various other novel testing procedures have been proposed, which generally are derived by assuming a class of specific alternative hypotheses with respect to the hazard functions. The test considered by Pepe and Fleming (1989) is based on a linear combination of weighted differences of the two Kaplan-Meier curves over time and is a natural tool to assess the difference of two survival functions directly. In this article, we take a similar approach but choose weights that are proportional to the observed standardized difference of the estimated survival curves at each time point. The new proposal automatically makes weighting adjustments empirically. The new test statistic is aimed at a one-sided general alternative hypothesis and is distributed with a short right tail under the null hypothesis but with a heavy tail under the alternative. The results from extensive numerical studies demonstrate that the new procedure performs well under various general alternatives with a caution of a minor inflation of the type I error rate when the sample size is small or the number of observed events is small. The survival data from a recent cancer comparative study are utilized for illustrating the implementation of the process. Copyright © 2015 John Wiley & Sons, Ltd.

Precision Determination of the Small-x Gluon from Charm Production at LHCb.

PubMed

Gauld, Rhorry; Rojo, Juan

2017-02-17

The small-x gluon in global fits of parton distributions is affected by large uncertainties from the lack of direct experimental constraints. In this Letter, we provide a precision determination of the small-x gluon from the exploitation of forward charm production data provided by LHCb for three different center-of-mass (c.m.) energies: 5 TeV, 7 TeV, and 13 TeV. The LHCb measurements are included in the parton distribution function (PDF) fit by means of normalized distributions and cross-section ratios between data taken at different c.m. values, R_{13/7} and R_{13/5}. We demonstrate that forward charm production leads to a reduction of the PDF uncertainties of the gluon down to x≃10^{-6} by up to an order of magnitude, with implications for high-energy colliders, cosmic ray physics, and neutrino astronomy.

Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals.

PubMed

Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Tanaka, Hiroshi; Kataoka, Takahiro; Sakoda, Akihiro

2011-07-01

A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects.

Neurological disorders in Gulf War veterans

PubMed Central

Rose, Michael R; Brix, Kelley Ann

2006-01-01

We present a review of neurological function in Gulf War veterans (GWV). Twenty-two studies were reviewed, including large hospitalization and registry studies, large population-based epidemiological studies, investigations of a single military unit, small uncontrolled studies of ill veterans and small controlled studies of veterans. In nearly all studies, neurological function was normal in most GWVs, except for a small proportion who were diagnosed with compression neuropathies (carpal tunnel syndrome or ulnar neuropathy). In the great majority of controlled studies, there were no differences in the rates of neurological abnormalities in GWVs and controls. In a national US study, the incidence of amyotrophic lateral sclerosis (ALS) seems to be significantly increased in GWVs, compared to the rate in controls. However, it is possible that military service, in general, might be associated with an increased risk of ALS, rather than Gulf War service in particular. Taken together, the conclusion is that if a neurological examination in a GWV is within normal limits, then extensive neurological testing is unlikely to diagnose occult neurological disorders. PMID:16687265

Small non coding RNAs in adipocyte biology and obesity.

PubMed

Amri, Ez-Zoubir; Scheideler, Marcel

2017-11-15

Obesity has reached epidemic proportions world-wide and constitutes a substantial risk factor for hypertension, type 2 diabetes, cardiovascular diseases and certain cancers. So far, regulation of energy intake by dietary and pharmacological treatments has met limited success. The main interest of current research is focused on understanding the role of different pathways involved in adipose tissue function and modulation of its mass. Whole-genome sequencing studies revealed that the majority of the human genome is transcribed, with thousands of non-protein-coding RNAs (ncRNA), which comprise small and long ncRNAs. ncRNAs regulate gene expression at the transcriptional and post-transcriptional level. Numerous studies described the involvement of ncRNAs in the pathogenesis of many diseases including obesity and associated metabolic disorders. ncRNAs represent potential diagnostic biomarkers and promising therapeutic targets. In this review, we focused on small ncRNAs involved in the formation and function of adipocytes and obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrastructural and functional characterization of circulating hemocytes from the freshwater crayfish Astacus leptodactylus: cell types and their role after in vivo artificial non-self challenge.

PubMed

Giulianini, Piero Giulio; Bierti, Manuel; Lorenzon, Simonetta; Battistella, Silvia; Ferrero, Enrico Antonio

2007-01-01

The freshwater crayfish Astacus leptodactylus (Eschscholtz, 1823) is an important aquacultured decapod species as well as an invasive species in some European countries. In the current investigation we characterized the different classes of circulating blood cells in A. leptodactylus by means of light and electron microscopy analysis and we explored their reaction to different latex beads particles in vivo by total and differential cell counts at 0.5, 1, 2 and 4h after injections. We identified hemocytes by granule size morphometry as hyaline hemocytes with no or rare tiny granules, small granule hemocytes, unimodal medium diameter granule hemocytes and both small and large granule containing hemocytes. The latter granular hemocytes showed the strongest phenoloxidase l-DOPA reactivity both in granules and cytoplasm. A. leptodactylus respond to foreign particles with strong cellular immune responses. All treatments elicited a total hemocyte increase with a conspicuous recruitment of large granule containing hemocytes. All hemocyte types mounted some phagocytic response but the small granule hemocytes were the only ones involved in phagocytic response to all foreign particles with the highest percentages. These results (1) depict the variability in decapod hemocyte functional morphology; (2) identify the small granule hemocyte as the major phagocytic cell; (3) suggest that the rather rapid recruitment of large granule hemocyte in all treatments plays a relevant role by this hemocyte type in defense against foreign particles, probably in nodule formation.

Estimation of the cost of electro-mechanical equipment for small hydropower plants - review and comparison of methods

NASA Astrophysics Data System (ADS)

Lipiński, Seweryn; Olkowski, Tomasz

2017-10-01

The estimate of the cost of electro-mechanical equipment for new small hydropower plants most often amounts to about 30-40% of the total budget. In case of modernization of existing installations, this estimation represents the main cost. This matter constitutes a research problem for at least few decades. Many models have been developed for that purpose. The aim of our work was to collect and analyse formulas that allow estimation of the cost of investment in electro-mechanical equipment for small hydropower plants. Over a dozen functions were analysed. To achieve the aim of our work, these functions were converted into the form allowing their comparison. Then the costs were simulated with respect to plants' powers and net heads; such approach is novel and allows deeper discussion of the problem, as well as drawing broader conclusions. The following conclusions can be drawn: significant differences in results obtained by using various formulas were observed; there is a need for a wide study based on national investments in small hydropower plants that would allow to develop equations based on local data; the obtained formulas would let to determinate the costs of modernization or a new construction of small hydropower plant more precisely; special attention should be payed to formulas considering turbine type.

Negative Impacts of Human Land Use on Dung Beetle Functional Diversity

PubMed Central

Barragán, Felipe; Moreno, Claudia E.; Escobar, Federico; Halffter, Gonzalo; Navarrete, Dario

2011-01-01

The loss of biodiversity caused by human activity is assumed to alter ecosystem functioning. However our understanding of the magnitude of the effect of these changes on functional diversity and their impact on the dynamics of ecological processes is still limited. We analyzed the functional diversity of copro-necrophagous beetles under different conditions of land use in three Mexican biosphere reserves. In Montes Azules pastures, forest fragments and continuous rainforest were analyzed, in Los Tuxtlas rainforest fragments of different sizes were analyzed and in Barranca de Metztitlán two types of xerophile scrub with different degrees of disturbance from grazing were analyzed. We assigned dung beetle species to functional groups based on food relocation, beetle size, daily activity period and food preferences, and as measures of functional diversity we used estimates based on multivariate methods. In Montes Azules functional richness was lower in the pastures than in continuous rainforest and rainforest fragments, but fragments and continuous forest include functionally redundant species. In small rainforest fragments (<5 ha) in Los Tuxtlas, dung beetle functional richness was lower than in large rainforest fragments (>20 ha). Functional evenness and functional dispersion did not vary among habitat types or fragment size in these reserves. In contrast, in Metztitlán, functional richness and functional dispersion were different among the vegetation types, but differences were not related to the degree of disturbance by grazing. More redundant species were found in submontane than in crassicaule scrub. For the first time, a decrease in the functional diversity in communities of copro-necrophagous beetles resulting from changes in land use is documented, the potential implications for ecosystem functioning are discussed and a series of variables that could improve the evaluation of functional diversity for this biological group is proposed. PMID:21448292

Negative impacts of human land use on dung beetle functional diversity.

PubMed

Barragán, Felipe; Moreno, Claudia E; Escobar, Federico; Halffter, Gonzalo; Navarrete, Dario

2011-03-23

The loss of biodiversity caused by human activity is assumed to alter ecosystem functioning. However our understanding of the magnitude of the effect of these changes on functional diversity and their impact on the dynamics of ecological processes is still limited. We analyzed the functional diversity of copro-necrophagous beetles under different conditions of land use in three Mexican biosphere reserves. In Montes Azules pastures, forest fragments and continuous rainforest were analyzed, in Los Tuxtlas rainforest fragments of different sizes were analyzed and in Barranca de Metztitlán two types of xerophile scrub with different degrees of disturbance from grazing were analyzed. We assigned dung beetle species to functional groups based on food relocation, beetle size, daily activity period and food preferences, and as measures of functional diversity we used estimates based on multivariate methods. In Montes Azules functional richness was lower in the pastures than in continuous rainforest and rainforest fragments, but fragments and continuous forest include functionally redundant species. In small rainforest fragments (<5 ha) in Los Tuxtlas, dung beetle functional richness was lower than in large rainforest fragments (>20 ha). Functional evenness and functional dispersion did not vary among habitat types or fragment size in these reserves. In contrast, in Metztitlán, functional richness and functional dispersion were different among the vegetation types, but differences were not related to the degree of disturbance by grazing. More redundant species were found in submontane than in crassicaule scrub. For the first time, a decrease in the functional diversity in communities of copro-necrophagous beetles resulting from changes in land use is documented, the potential implications for ecosystem functioning are discussed and a series of variables that could improve the evaluation of functional diversity for this biological group is proposed.

SU-E-T-299: Small Fields Profiles Correction Through Detectors Spatial Response Functions and Field Size Dependence Analysis

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

Filipuzzi, M; Garrigo, E; Venencia, C

2014-06-01

Purpose: To calculate the spatial response function of various radiation detectors, to evaluate the dependence on the field size and to analyze the small fields profiles corrections by deconvolution techniques. Methods: Crossline profiles were measured on a Novalis Tx 6MV beam with a HDMLC. The configuration setup was SSD=100cm and depth=5cm. Five fields were studied (200×200mm2,100×100mm2, 20×20mm2, 10×10mm2and 5×5mm2) and measured were made with passive detectors (EBT3 radiochromic films and TLD700 thermoluminescent detectors), ionization chambers (PTW30013, PTW31003, CC04 and PTW31016) and diodes (PTW60012 and IBA SFD). The results of passive detectors were adopted as the actual beam profile. To calculatemore » the detectors kernels, modeled by Gaussian functions, an iterative process based on a least squares criterion was used. The deconvolutions of the measured profiles were calculated with the Richardson-Lucy method. Results: The profiles of the passive detectors corresponded with a difference in the penumbra less than 0.1mm. Both diodes resolve the profiles with an overestimation of the penumbra smaller than 0.2mm. For the other detectors, response functions were calculated and resulted in Gaussian functions with a standard deviation approximate to the radius of the detector in study (with a variation less than 3%). The corrected profiles resolve the penumbra with less than 1% error. Major discrepancies were observed for cases in extreme conditions (PTW31003 and 5×5mm2 field size). Conclusion: This work concludes that the response function of a radiation detector is independent on the field size, even for small radiation beams. The profiles correction, using deconvolution techniques and response functions of standard deviation equal to the radius of the detector, gives penumbra values with less than 1% difference to the real profile. The implementation of this technique allows estimating the real profile, freeing from the effects of the detector used for the acquisition.« less

Genetic Variation at the N-acetyltransferase (NAT) Genes in Global Populations

EPA Science Inventory

Functional variability at the N-acetyltransferase (NAT) genes is associated with adverse drug reactions and cancer susceptibility in humans. Previous studies of small sets of ethnic groups have indicated that the NAT genes have high levels of amino acid variation that differ in f...

Research on reducing the edge effect in magnetorheological finishing.

PubMed

Hu, Hao; Dai, Yifan; Peng, Xiaoqiang; Wang, Jianmin

2011-03-20

The edge effect could not be avoided in most optical manufacturing methods based on the theory of computer controlled optical surfacing. The difference between the removal function at the workpiece edge and that inside it is also the primary cause for edge effect in magnetorheological finishing (MRF). The change of physical dimension and removal ratio of the removal function is investigated through experiments. The results demonstrate that the situation is different when MRF "spot" is at the leading edge or at the trailing edge. Two methods for reducing the edge effect are put into practice after analysis of the processing results. One is adopting a small removal function for dealing with the workpiece edge, and the other is utilizing the removal function compensation. The actual processing results show that these two ways are both effective on reducing the edge effect in MRF.

Fundamental equations of a mixture of gas and small spherical solid particles from simple kinetic theory.

NASA Technical Reports Server (NTRS)

Pai, S. I.

1973-01-01

The fundamental equations of a mixture of a gas and pseudofluid of small spherical solid particles are derived from the Boltzmann equation of two-fluid theory. The distribution function of the gas molecules is defined in the same manner as in the ordinary kinetic theory of gases, but the distribution function for the solid particles is different from that of the gas molecules, because it is necessary to take into account the different size and physical properties of solid particles. In the proposed simple kinetic theory, two additional parameters are introduced: one is the radius of the spheres and the other is the instantaneous temperature of the solid particles in the distribution of the solid particles. The Boltzmann equation for each species of the mixture is formally written, and the transfer equations of these Boltzmann equations are derived and compared to the well-known fundamental equations of the mixture of a gas and small solid particles from continuum theory. The equations obtained reveal some insight into various terms in the fundamental equations. For instance, the partial pressure of the pseudofluid of solid particles is not negligible if the volume fraction of solid particles is not negligible as in the case of lunar ash flow.

The gravitational law of social interaction

NASA Astrophysics Data System (ADS)

Levy, Moshe; Goldenberg, Jacob

2014-01-01

While a great deal is known about the topology of social networks, there is much less agreement about the geographical structure of these networks. The fundamental question in this context is: how does the probability of a social link between two individuals depend on the physical distance between them? While it is clear that the probability decreases with the distance, various studies have found different functional forms for this dependence. The exact form of the distance dependence has crucial implications for network searchability and dynamics: Kleinberg (2000) [15] shows that the small-world property holds if the probability of a social link is a power-law function of the distance with power -2, but not with any other power. We investigate the distance dependence of link probability empirically by analyzing four very different sets of data: Facebook links, data from the electronic version of the Small-World experiment, email messages, and data from detailed personal interviews. All four datasets reveal the same empirical regularity: the probability of a social link is proportional to the inverse of the square of the distance between the two individuals, analogously to the distance dependence of the gravitational force. Thus, it seems that social networks spontaneously converge to the exact unique distance dependence that ensures the Small-World property.

Synthesis, characterization and optical properties of an amino-functionalized gold thiolate cluster: Au10(SPh-pNH2)10.

PubMed

Lavenn, Christophe; Albrieux, Florian; Tuel, Alain; Demessence, Aude

2014-03-15

Research interest in ultra small gold thiolate clusters has been rising in recent years for the challenges they offer to bring together properties of nanoscience and well-defined materials from molecular chemistry. Here, a new atomically well-defined Au10 gold nanocluster surrounded by ten 4-aminothiophenolate ligands is reported. Its synthesis followed the similar conditions reported for the elaboration of Au144(SR)60, but because the reactivity of thiophenol ligands is different from alkanethiol derivates, smaller Au10 clusters were formed. Different techniques, such as ESI-MS, elemental analysis, XRD, TGA, XPS and UV-vis-NIR experiments, have been carried out to determine the Au10(SPh-pNH2)10 formula. Photoemission experiment has been done and reveals that the Au10 clusters are weakly luminescent as opposed to the amino-based ultra-small gold clusters. This observation points out that the emission of gold thiolate clusters is highly dependent on both the structure of the gold core and the type of the ligands at the surface. In addition, ultra-small amino-functionalized clusters offer the opportunity for extended work on self-assembling networks or deposition on substrates for nanotechnologies or catalytic applications. Copyright © 2013 Elsevier Inc. All rights reserved.

[Communication and language in the autistic spectrum: autism and dysphasia].

PubMed

Martos, J; Ayuda, R

2002-02-01

The alterations of language and communication seen in children with autistic spectrum disorders (TEA) have some similar and some dissimilar features to those seen in children with specific language disorders (TEL). The basic disorder of TEA seems to be due to alterations in the social and mental use of codes of communication, both verbal and non verbal. Children with TEL however have better non verbal and practical abilities. In view of this, we decided to determine the qualitative difference in function in communication and language between the two populations. The great heterogeneity between persons with autistic spectrum disorders and even variation between individuals makes investigation of large groups difficult. It is therefore necessary to study individual cases or groups with small numbers. If we fix our attention on language and communication, it is important to define subtypes of function with the population affected by the autistic spectrum of disorders at an early age, in the fields of communication, receptive language and expressive language in our small sample of persons; taking the normal course of development in each field as the parameter for comparison. This is a pilot study within a long term research project. The results reported here are the preliminary findings of what will be a more extensive study with fuller analysis of the results. The preliminary findings suggest that there are different linguistic and communication function profiles in the different populations compared.

SVM and SVM Ensembles in Breast Cancer Prediction.

PubMed

Huang, Min-Wei; Chen, Chih-Wen; Lin, Wei-Chao; Ke, Shih-Wen; Tsai, Chih-Fong

2017-01-01

Breast cancer is an all too common disease in women, making how to effectively predict it an active research problem. A number of statistical and machine learning techniques have been employed to develop various breast cancer prediction models. Among them, support vector machines (SVM) have been shown to outperform many related techniques. To construct the SVM classifier, it is first necessary to decide the kernel function, and different kernel functions can result in different prediction performance. However, there have been very few studies focused on examining the prediction performances of SVM based on different kernel functions. Moreover, it is unknown whether SVM classifier ensembles which have been proposed to improve the performance of single classifiers can outperform single SVM classifiers in terms of breast cancer prediction. Therefore, the aim of this paper is to fully assess the prediction performance of SVM and SVM ensembles over small and large scale breast cancer datasets. The classification accuracy, ROC, F-measure, and computational times of training SVM and SVM ensembles are compared. The experimental results show that linear kernel based SVM ensembles based on the bagging method and RBF kernel based SVM ensembles with the boosting method can be the better choices for a small scale dataset, where feature selection should be performed in the data pre-processing stage. For a large scale dataset, RBF kernel based SVM ensembles based on boosting perform better than the other classifiers.

SVM and SVM Ensembles in Breast Cancer Prediction

PubMed Central

Huang, Min-Wei; Chen, Chih-Wen; Lin, Wei-Chao; Ke, Shih-Wen; Tsai, Chih-Fong

2017-01-01

Breast cancer is an all too common disease in women, making how to effectively predict it an active research problem. A number of statistical and machine learning techniques have been employed to develop various breast cancer prediction models. Among them, support vector machines (SVM) have been shown to outperform many related techniques. To construct the SVM classifier, it is first necessary to decide the kernel function, and different kernel functions can result in different prediction performance. However, there have been very few studies focused on examining the prediction performances of SVM based on different kernel functions. Moreover, it is unknown whether SVM classifier ensembles which have been proposed to improve the performance of single classifiers can outperform single SVM classifiers in terms of breast cancer prediction. Therefore, the aim of this paper is to fully assess the prediction performance of SVM and SVM ensembles over small and large scale breast cancer datasets. The classification accuracy, ROC, F-measure, and computational times of training SVM and SVM ensembles are compared. The experimental results show that linear kernel based SVM ensembles based on the bagging method and RBF kernel based SVM ensembles with the boosting method can be the better choices for a small scale dataset, where feature selection should be performed in the data pre-processing stage. For a large scale dataset, RBF kernel based SVM ensembles based on boosting perform better than the other classifiers. PMID:28060807

Multiple scattered radiation emerging from Rayleigh and continental haze layers. 1: Radiance, polarization, and neutral points.

PubMed

Kattawar, G W; Plass, G N; Hitzfelder, S J

1976-03-01

The complete radiation field including polarization is calculated by the matrix operator method for scattering layers of various optical thicknesses. Results obtained for Rayleigh scattering are compared with those for scattering from a continental haze. Radiances calculated using Stokes vectors show differences as large as 23% compared to the approximate scalar theory of radiative transfer, while the same differences are only of the order of 0.1% for a continental haze phase function. The polarization of the reflected and transmitted radiation is given for a wide range of optical thicknesses of the scattering layer, for various solar zenith angles, and various surface albedos. Two entirely different types of neutral points occur for aerosol phase functions. Rayleigh-like neutral points (RNP) arise from the zero polarization in single scattering that occurs for all phase functions at scattering angles of 0 degrees and 180 degrees . For Rayleigh phase functions, the position of the RNP varies appreciably with the optical thickness of the scattering layer. At low solar elevations there may be four RNP. For a continental haze phase function the position of the RNP in the reflected radiation shows only a small variation with the optical thickness, and the RNP exists in the transmitted radiation only for extremely small optical thicknesses. Another type of neutral point (NRNP) exists for aerosol phase functions. It is associated with the zeros of the single scattered polarization, which occur between the end points of the curve; these are called non-Rayleigh neutral points (NRNP). There may be from zero to four of these neutral points associated with each zero of the single scattering curve. They occur over a range of azimuthal angles, unlike the RNP that are in the principal plane only. The position of these neutral points is given as a function of solar angle and optical thickness.

Right ventricular function after repair of tetralogy of Fallot: a comparison between bovine pericardium and porcine small intestinal extracellular matrix.

PubMed

Naik, Ronak; Johnson, Jason; Kumar, T K S; Philip, Ranjit; Boston, Umar; Knott-Craig, Christopher J

2017-05-29

The porcine small intestinal extracellular matrix reportedly has the potential to differentiate into viable myocardial cells. When used in tetralogy of Fallot repair, it may improve right ventricular function. We evaluated right ventricular function after repair of tetralogy of Fallot with extracellular matrix versus bovine pericardium. Subjects with non-transannular repair of tetralogy of Fallot with at least 1 year of follow-up were selected. The extracellular matrix and bovine pericardium groups were compared. We used three-dimensional right ventricular ejection fraction, right ventricle global longitudinal strain, and tricuspid annular plane systolic excursion to assess right ventricular function. The extracellular matrix group had 11 patients, whereas the bovine pericardium group had 10 patients. No differences between the groups were found regarding sex ratio, age at surgery, and cardiopulmonary bypass time. The follow-up period was 28±12.6 months in the extracellular matrix group and 50.05±17.6 months in the bovine pericardium group (p=0.001). The mean three-dimensional right ventricular ejection fraction (55.7±5.0% versus 55.3±5.2%, p=0.73), right ventricular global longitudinal strain (-18.5±3.0% versus -18.0±2.2%, p=0.44), and tricuspid annular plane systolic excursions (1.59±0.16 versus 1.59±0.2, p=0.93) were similar in the extracellular matrix group and in the bovine pericardium group, respectively. Right ventricular global longitudinal strain in healthy children is reported at -29±3% in literature. In a small cohort of the patients undergoing non-transannular repair of tetralogy of Fallot, there was no significant difference in right ventricular function between groups having extracellular matrix versus bovine pericardium patches followed-up for more than 1 year. Lower right ventricular longitudinal strain noted in both the groups compared to healthy children.

Orthogonal functionalization of nanoporous substrates: control of 3D surface functionality.

PubMed

Lazzara, Thomas D; Kliesch, Torben-Tobias; Janshoff, Andreas; Steinem, Claudia

2011-04-01

Anodic aluminum oxide (AAO) membranes with aligned, cylindrical, nonintersecting pores were selectively functionalized in order to create dual-functionality substrates with different pore-rim and pore-interior surface functionalities, using silane chemistry. We used a two-step process involving an evaporated thin gold film to protect the underlying surface functionality of the pore rims. Subsequent treatment with oxygen plasma of the modified AAO membrane removed the unprotected organic functional groups, i.e., the pore-interior surface. After gold removal, the substrate became optically transparent, and displayed two distinct surface functionalities, one at the pore-rim surface and another at the pore-interior surface. We achieved a selective hydrophobic functionalization with dodecyl-trichlorosilane of either the pore rims or the pore interiors. The deposition of planar lipid membranes on the functionalized areas by addition of small unilamellar vesicles occurred in a predetermined fashion. Small unilamellar vesicles only ruptured upon contact with the hydrophobic substrate regions forming solid supported hybrid bilayers. In addition, pore-rim functionalization with dodecyl-trichlorosilane allowed the formation of pore-spanning hybrid lipid membranes as a result of giant unilamellar vesicle rupture. Confocal laser scanning microscopy was employed to identify the selective spatial localization of the adsorbed fluorescently labeled lipids. The corresponding increase in the AAO refractive index due to lipid adsorption on the hydrophobic regions was monitored by optical waveguide spectroscopy. This simple orthogonal functionalization route is a promising method to control the three-dimensional surface functionality of nanoporous films. © 2011 American Chemical Society

Short-term memory for responses: the "choose-small" effect.

PubMed Central

Fetterman, J G; MacEwen, D

1989-01-01

Pigeons' short-term memory for fixed-ratio requirements was assessed using a delayed symbolic matching-to-sample procedure. Different choices were reinforced after fixed-ratio 10 and fixed-ratio 40 requirements, and delays of 0, 5, or 20 s were sometimes placed between sample ratios and choice. All birds made disproportionate numbers of responses to the small-ratio choice alternative when delays were interposed between ratios and choice, and this bias increased as a function of delay. Preference for the small fixed-ratio alternative was also observed on "no-sample" trials, during which the choice alternatives were presented without a prior sample ratio. This "choose-small" bias is analogous to results obtained by Spetch and Wilkie (1983) with event duration as the discriminative stimulus. The choose-small bias was attenuated when the houselight was turned on during delays, but overall accuracy was not influenced systematically by the houselight manipulation. PMID:2584917

Computational prediction of the pKas of small peptides through Conceptual DFT descriptors

NASA Astrophysics Data System (ADS)

Frau, Juan; Hernández-Haro, Noemí; Glossman-Mitnik, Daniel

2017-03-01

The experimental pKa of a group of simple amines have been plotted against several Conceptual DFT descriptors calculated by means of different density functionals, basis sets and solvation schemes. It was found that the best fits are those that relate the pKa of the amines with the global hardness η through the MN12SX density functional in connection with the Def2TZVP basis set and the SMD solvation model, using water as a solvent. The parameterized equation resulting from the linear regression analysis has then been used for the prediction of the pKa of small peptides of interest in the study of diabetes and Alzheimer disease. The accuracy of the results is relatively good, with a MAD of 0.36 units of pKa.

Quantification, validation, and follow-up of small bowel motility in Crohn's disease

NASA Astrophysics Data System (ADS)

Cerrolaza, Juan J.; Peng, Jennifer Q.; Safdar, Nabile M.; Conklin, Laurie; Sze, Raymond; Linguraru, Marius George

2015-03-01

The use of magnetic resonance enterography (MRE) has become a mainstay in the evaluation, assessment and follow up of inflammatory bowel diseases, such as Crohn's disease (CD), thanks to its high image quality and its non-ionizing nature. In particular, the advent of faster MRE sequences less sensitive to image-motion artifacts offers the possibility to obtain visual, structural and functional information of the patient's small bowel. However, the inherent subjectivity of the mere visual inspection of these images often hinders the accurate identification and monitoring of the pathological areas. In this paper, we present a framework that provides quantitative and objective motility information of the small bowel from free-breathing MRE dynamic sequences. After compensating for the breathing motion of the patient, we create personalized peristaltic activity maps via optical flow analysis. The result is the creation of a new set of images providing objective and precise functional information of the small bowel. The accuracy of the new method was also evaluated from two different perspectives: objective accuracy (1.1 ± 0.6 mm/s of error), i.e., the ability of the system to provide quantitative and accurate information about the motility of moving bowel landmarks, and subjective accuracy (avg. difference of 0.7 ± 0.7 in a range of 1 to 5), i.e., the degree of agreement with the subjective evaluation of an expert. Finally, the practical utility of the new method was successfully evaluated in a preliminary study with 32 studies of healthy and CD cases, showing its potential for the fast and accurate assessment and follow up of CD in the small bowel.

Permeabilization of brain tissue in situ enables multiregion analysis of mitochondrial function in a single mouse brain.

PubMed

Herbst, Eric A F; Holloway, Graham P

2015-02-15

Mitochondrial function in the brain is traditionally assessed through analysing respiration in isolated mitochondria, a technique that possesses significant tissue and time requirements while also disrupting the cooperative mitochondrial reticulum. We permeabilized brain tissue in situ to permit analysis of mitochondrial respiration with the native mitochondrial morphology intact, removing the need for isolation time and minimizing tissue requirements to ∼2 mg wet weight. The permeabilized brain technique was validated against the traditional method of isolated mitochondria and was then further applied to assess regional variation in the mouse brain with ischaemia-reperfusion injuries. A transgenic mouse model overexpressing catalase within mitochondria was applied to show the contribution of mitochondrial reactive oxygen species to ischaemia-reperfusion injuries in different brain regions. This technique enhances the accessibility of addressing physiological questions in small brain regions and in applying transgenic mouse models to assess mechanisms regulating mitochondrial function in health and disease. Mitochondria function as the core energy providers in the brain and symptoms of neurodegenerative diseases are often attributed to their dysregulation. Assessing mitochondrial function is classically performed in isolated mitochondria; however, this process requires significant isolation time, demand for abundant tissue and disruption of the cooperative mitochondrial reticulum, all of which reduce reliability when attempting to assess in vivo mitochondrial bioenergetics. Here we introduce a method that advances the assessment of mitochondrial respiration in the brain by permeabilizing existing brain tissue to grant direct access to the mitochondrial reticulum in situ. The permeabilized brain preparation allows for instant analysis of mitochondrial function with unaltered mitochondrial morphology using significantly small sample sizes (∼2 mg), which permits the analysis of mitochondrial function in multiple subregions within a single mouse brain. Here this technique was applied to assess regional variation in brain mitochondrial function with acute ischaemia-reperfusion injuries and to determine the role of reactive oxygen species in exacerbating dysfunction through the application of a transgenic mouse model overexpressing catalase within mitochondria. Through creating accessibility to small regions for the investigation of mitochondrial function, the permeabilized brain preparation enhances the capacity for examining regional differences in mitochondrial regulation within the brain, as the majority of genetic models used for unique approaches exist in the mouse model. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

SSX2-4 expression in early-stage non-small cell lung cancer.

PubMed

Greve, K B V; Pøhl, M; Olsen, K E; Nielsen, O; Ditzel, H J; Gjerstorff, M F

2014-05-01

The expression of cancer/testis antigens SSX2, SSX3, and SSX4 in non-small cell lung cancers (NSCLC) was examined, since they are considered promising targets for cancer immunotherapy due to their immunogenicity and testis-restricted normal tissue expression. We characterized three SSX antibodies and performed immunohistochemical staining of 25 different normal tissues and 143 NSCLCs. The antibodies differed in binding to two distinctive splice variants of SSX2 that exhibited different subcellular staining patterns, suggesting that the two splice variants display different functions. SSX2-4 expression was only detected in 5 of 143 early-stage NSCLCs, which is rare compared to other cancer/testis antigens (e.g. MAGE-A and GAGE). However, further studies are needed to determine whether SSX can be used as a prognostic or predictive biomarker in NSCLC. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Warming and top predator loss drive ecosystem multifunctionality.

PubMed

Antiqueira, Pablo Augusto P; Petchey, Owen L; Romero, Gustavo Quevedo

2018-01-01

Global change affects ecosystem functioning both directly by modifications in physicochemical processes, and indirectly, via changes in biotic metabolism and interactions. Unclear, however, is how multiple anthropogenic drivers affect different components of community structure and the performance of multiple ecosystem functions (ecosystem multifunctionality). We manipulated small natural freshwater ecosystems to investigate how warming and top predator loss affect seven ecosystem functions representing two major dimensions of ecosystem functioning, productivity and metabolism. We investigated their direct and indirect effects on community diversity and standing stock of multitrophic macro and microorganisms. Warming directly increased multifunctional ecosystem productivity and metabolism. In contrast, top predator loss indirectly affected multifunctional ecosystem productivity via changes in the diversity of detritivorous macroinvertebrates, but did not affect ecosystem metabolism. In addition to demonstrating how multiple anthropogenic drivers have different impacts, via different pathways, on ecosystem multifunctionality components, our work should further spur advances in predicting responses of ecosystems to multiple simultaneous environmental changes. © 2017 John Wiley & Sons Ltd/CNRS.

A Functional Theory of Creative Reading

DTIC Science & Technology

1994-01-01

small an area results in a theory having to explain too much outside its scope, leading to overload and eventual failure . We present a functional...of several of the issues which a reading system must address. I’m an archaeologist, and Men are my business . Just the same, I wonder if we’ll ever...formal business setting. Several of these social relations can be seen in Men Are Different: the protagonist is a peer among the robot archaeologists

A resource for functional profiling of noncoding RNA in the yeast Saccharomyces cerevisiae.

PubMed

Parker, Steven; Fraczek, Marcin G; Wu, Jian; Shamsah, Sara; Manousaki, Alkisti; Dungrattanalert, Kobchai; de Almeida, Rogerio Alves; Estrada-Rivadeneyra, Diego; Omara, Walid; Delneri, Daniela; O'Keefe, Raymond T

2017-08-01

Eukaryotic genomes are extensively transcribed, generating many different RNAs with no known function. We have constructed 1502 molecular barcoded ncRNA gene deletion strains encompassing 443 ncRNAs in the yeast Saccharomyces cerevisiae as tools for ncRNA functional analysis. This resource includes deletions of small nuclear RNAs (snRNAs), transfer RNAs (tRNAs), small nucleolar RNAs (snoRNAs), and other annotated ncRNAs as well as the more recently identified stable unannotated transcripts (SUTs) and cryptic unstable transcripts (CUTs) whose functions are largely unknown. Specifically, deletions have been constructed for ncRNAs found in the intergenic regions, not overlapping genes or their promoters (i.e., at least 200 bp minimum distance from the closest gene start codon). The deletion strains carry molecular barcodes designed to be complementary with the protein gene deletion collection enabling parallel analysis experiments. These strains will be useful for the numerous genomic and molecular techniques that utilize deletion strains, including genome-wide phenotypic screens under different growth conditions, pooled chemogenomic screens with drugs or chemicals, synthetic genetic array analysis to uncover novel genetic interactions, and synthetic dosage lethality screens to analyze gene dosage. Overall, we created a valuable resource for the RNA community and for future ncRNA research. © 2017 Parker et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Evaluating a Psychology Graduate Student Peer Mentoring Program

ERIC Educational Resources Information Center

Fleck, Christina; Mullins, Morell E.

2012-01-01

Research on mentoring outcomes and characteristics of various types of mentoring programs in different settings is limited. The present study sampled 39 graduate students at a small Midwestern university to evaluate peer mentoring in a graduate school setting. Mentoring function and outcome relationships as well as program characteristics were…

Indiana's Academic Standards: Economics--Social Studies

ERIC Educational Resources Information Center

Indiana Department of Education, 2004

2004-01-01

In this standard, students learn how economies, large and small, function. Supply and demand are covered in depth, and students learn to identify the production, consumption, and circulation of different types of resources in local, state, national, and world economies. Students also learn about employment and personal finance, as well as the…

Speech Discrimination Difficulties in High-Functioning Autism Spectrum Disorder Are Likely Independent of Auditory Hypersensitivity

PubMed Central

Dunlop, William A.; Enticott, Peter G.; Rajan, Ramesh

2016-01-01

Autism Spectrum Disorder (ASD), characterized by impaired communication skills and repetitive behaviors, can also result in differences in sensory perception. Individuals with ASD often perform normally in simple auditory tasks but poorly compared to typically developed (TD) individuals on complex auditory tasks like discriminating speech from complex background noise. A common trait of individuals with ASD is hypersensitivity to auditory stimulation. No studies to our knowledge consider whether hypersensitivity to sounds is related to differences in speech-in-noise discrimination. We provide novel evidence that individuals with high-functioning ASD show poor performance compared to TD individuals in a speech-in-noise discrimination task with an attentionally demanding background noise, but not in a purely energetic noise. Further, we demonstrate in our small sample that speech-hypersensitivity does not appear to predict performance in the speech-in-noise task. The findings support the argument that an attentional deficit, rather than a perceptual deficit, affects the ability of individuals with ASD to discriminate speech from background noise. Finally, we piloted a novel questionnaire that measures difficulty hearing in noisy environments, and sensitivity to non-verbal and verbal sounds. Psychometric analysis using 128 TD participants provided novel evidence for a difference in sensitivity to non-verbal and verbal sounds, and these findings were reinforced by participants with ASD who also completed the questionnaire. The study was limited by a small and high-functioning sample of participants with ASD. Future work could test larger sample sizes and include lower-functioning ASD participants. PMID:27555814

Small differences in amylopectin fine structure may explain large functional differences of starch.

PubMed

Bertoft, Eric; Annor, George A; Shen, Xinyu; Rumpagaporn, Pinthip; Seetharaman, Koushik; Hamaker, Bruce R

2016-04-20

Four amylose-free waxy rice starches were found to give rise to gels with clearly different morphology after storage for seven days at 4°C. The thermal and rheological properties of these gels were also different. This was remarkable in light of the subtle differences in the molecular structure of the amylopectin in the samples. Addition of iodine to the amylopectin samples suggested that not only external chains, but also the internal chains of amylopectin, could form helical inclusion complexes. It is suggested that these internal helical segments participate in the retrogradation of amylopectin, thereby stabilising the gels through double helical structures with external chains of adjacent molecules. Albeit few in number, such interactions appear to have important influences on starch functional properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Changes in Pulmonary Function After Stereotactic Body Radiotherapy and After Surgery for Stage I and II Non-small Cell Lung Cancer, a Description of Two Cohorts.

PubMed

Alberts, Leonie; El Sharouni, Sherif Y; Hofman, Frederik N; Van Putte, Bart P; Tromp, Ellen; Van Vulpen, Marco; Kastelijn, Elisabeth A; Schramel, Franz M N H

2015-12-01

To evaluate changes in pulmonary function tests (PFTs) at different follow-up durations after stereotactic body radiotherapy (SBRT) and surgery in stage I and II non-small-cell lung cancer (NSCLC). Differences between pre-treatment- and follow-up PFTs were analyzed in 93 patients treated with surgery and 30 patients treated with SBRT for NSCLC. Follow-up durations were categorized into: early (0-9 months), middle (10-21 months) and late (≥22 months). Wilcoxon signed-rank test was used to analyze differences between pre-treatment and follow-up PFTs. Forced expiratory volume in one second, forced vital capacity and diffusion capacity for carbon monoxide corrected for the actual hemoglobin level significantly diminished after surgery for all follow-up durations: 11-17% of predicted values. After SBRT, PFTs remained stable, but a declining trend of 6% (p=0.1) was observed after 22 months. SBRT might lead to less treatment-related toxicity measured by PFTs than surgery in both the short and long term. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Developing students' functional thinking in algebra through different visualisations of a growing pattern's structure

NASA Astrophysics Data System (ADS)

Wilkie, Karina J.; Clarke, Doug M.

2016-06-01

Spatial visualisation of geometric patterns and their generalisation have become a recognised pathway to developing students' functional thinking and understanding of variables in algebra. This design-based research project investigated upper primary students' development of explicit generalisation of functional relationships and their representation descriptively, graphically and symbolically. Ten teachers and their classes were involved in a sequence of tasks involving growing patterns and geometric structures over 1 year. This article focuses on two aspects of the study: visualising the structure of a geometric pattern in different ways and using this to generalise the functional relationship between two quantifiable aspects (variables). It was found that in an initial assessment task ( n = 222), students' initial visualisations could be categorised according to different types and some of these were more likely to lead either to recursive or explicit generalisation. In a later task, a small number of students demonstrated the ability to find more than one way to visualise the same geometric structure and thus represent their explicit generalisations as different but equivalent symbolic equations (using pronumerals). Implications for the teaching of functional thinking in middle-school algebra are discussed.

Soft materials design via self assembly of functionalized icosahedral particles

NASA Astrophysics Data System (ADS)

Muthukumar, Vidyalakshmi Chockalingam

In this work we simulate self assembly of icosahedral building blocks using a coarse grained model of the icosahedral capsid of virus 1m1c. With significant advancements in site-directed functionalization of these macromolecules [1], we propose possible application of such self-assembled materials for drug delivery. While there have been some reports on organization of viral particles in solution through functionalization, exploiting this behaviour for obtaining well-ordered stoichiometric structures has not yet been explored. Our work is in well agreement with the earlier simulation studies of icosahedral gold nanocrystals, giving chain like patterns [5] and also broadly in agreement with the wet lab works of Finn, M.G. et al., who have shown small predominantly chain-like aggregates with mannose-decorated Cowpea Mosaic Virus (CPMV) [22] and small two dimensional aggregates with oligonucleotide functionalization on the CPMV capsid [1]. To quantify the results of our Coarse Grained Molecular Dynamics Simulations I developed analysis routines in MATLAB using which we found the most preferable nearest neighbour distances (from the radial distribution function (RDF) calculations) for different lengths of the functional groups and under different implicit solvent conditions, and the most frequent coordination number for a virus particle (histogram plots further using the information from RDF). Visual inspection suggests that our results most likely span the low temperature limits explored in the works of Finn, M.G. et al., and show a good degree of agreement with the experimental results in [1] at an annealing temperature of 4°C. Our work also reveals the possibility of novel stoichiometric N-mer type aggregates which could be synthesized using these capsids with appropriate functionalization and solvent conditions.

Assessment of lung function in a large cohort of patients with acromegaly.

PubMed

Störmann, Sylvère; Gutt, Bodo; Roemmler-Zehrer, Josefine; Bidlingmaier, Martin; Huber, Rudolf M; Schopohl, Jochen; Angstwurm, Matthias W

2017-07-01

Acromegaly is associated with increased mortality due to respiratory disease. To date, lung function in patients with acromegaly has only been assessed in small studies, with contradicting results. We assessed lung function parameters in a large cohort of patients with acromegaly. Lung function of acromegaly patients was prospectively assessed using spirometry, blood gas analysis and body plethysmography. Biochemical indicators of acromegaly were assessed through measurement of growth hormone and IGF-I levels. This study was performed at the endocrinology outpatient clinic of a tertiary referral center in Germany. We prospectively tested lung function of 109 acromegaly patients (53 male, 56 female; aged 24-82 years; 80 with active acromegaly) without severe acute or chronic pulmonary disease. We compared lung volume, air flow, airway resistance and blood gases to normative data. Acromegaly patients had greater lung volumes (maximal vital capacity, intra-thoracic gas volume and residual volume: P  < 0.001, total lung capacity: P  = 0.006) and showed signs of small airway obstruction (reduced maximum expiratory flow when 75% of the forced vital capacity (FVC) has been exhaled: P  < 0.001, lesser peak expiratory flow: P  = 0.01). There was no significant difference between active and inactive acromegaly. Female patients had significantly altered lung function in terms of subclinical airway obstruction. In our cross-sectional analysis of lung function in 109 patients with acromegaly, lung volumes were increased compared to healthy controls. Additionally, female patients showed signs of subclinical airway obstruction. There was no difference between patients with active acromegaly compared with patients biochemically in remission. © 2017 European Society of Endocrinology.

Revisiting Neil Armstrongs Moon-Landing Quote: Implications for Speech Perception, Function Word Reduction, and Acoustic Ambiguity

PubMed Central

Baese-Berk, Melissa M.; Dilley, Laura C.; Schmidt, Stephanie; Morrill, Tuuli H.; Pitt, Mark A.

2016-01-01

Neil Armstrong insisted that his quote upon landing on the moon was misheard, and that he had said one small step for a man, instead of one small step for man. What he said is unclear in part because function words like a can be reduced and spectrally indistinguishable from the preceding context. Therefore, their presence can be ambiguous, and they may disappear perceptually depending on the rate of surrounding speech. Two experiments are presented examining production and perception of reduced tokens of for and for a in spontaneous speech. Experiment 1 investigates the distributions of several acoustic features of for and for a. The results suggest that the distributions of for and for a overlap substantially, both in terms of temporal and spectral characteristics. Experiment 2 examines perception of these same tokens when the context speaking rate differs. The perceptibility of the function word a varies as a function of this context speaking rate. These results demonstrate that substantial ambiguity exists in the original quote from Armstrong, and that this ambiguity may be understood through context speaking rate. PMID:27603209

Revisiting Neil Armstrongs Moon-Landing Quote: Implications for Speech Perception, Function Word Reduction, and Acoustic Ambiguity.

PubMed

Baese-Berk, Melissa M; Dilley, Laura C; Schmidt, Stephanie; Morrill, Tuuli H; Pitt, Mark A

2016-01-01

Neil Armstrong insisted that his quote upon landing on the moon was misheard, and that he had said one small step for a man, instead of one small step for man. What he said is unclear in part because function words like a can be reduced and spectrally indistinguishable from the preceding context. Therefore, their presence can be ambiguous, and they may disappear perceptually depending on the rate of surrounding speech. Two experiments are presented examining production and perception of reduced tokens of for and for a in spontaneous speech. Experiment 1 investigates the distributions of several acoustic features of for and for a. The results suggest that the distributions of for and for a overlap substantially, both in terms of temporal and spectral characteristics. Experiment 2 examines perception of these same tokens when the context speaking rate differs. The perceptibility of the function word a varies as a function of this context speaking rate. These results demonstrate that substantial ambiguity exists in the original quote from Armstrong, and that this ambiguity may be understood through context speaking rate.

Rescue of the apoptotic-inducing function of mutant p53 by small molecule RITA.

PubMed

Zhao, Carolyn Y; Grinkevich, Vera V; Nikulenkov, Fedor; Bao, Wenjie; Selivanova, Galina

2010-05-01

Expression of mutant p53 correlates with poor prognosis in many tumors, therefore strategies aimed at reactivation of mutant p53 are likely to provide important benefits for treatment of tumors that are resistant to chemotherapy and radiotherapy. We have previously identified and characterized a small molecule RITA which binds p53 and induces a conformational change which prevents the binding of p53 to several inhibitors, including its own destructor MDM2. In this way, RITA rescues the tumor suppression function of wild type p53. Here, we demonstrate that RITA suppressed the growth and induced apoptosis in human tumor cell lines of a diverse origin carrying mutant p53 proteins. RITA restored transcriptional transactivation and transrepression function of several hot spot p53 mutants. The ability of RITA to rescue the activity of different p53 mutants suggests its generic mechanism of action. Thus, RITA is a promising lead for the development of anti-cancer drugs that reactivate the tumor suppressor function of p53 in cancer cells irrespective whether they express mutant or wild type p53.

The charger transfer electronic coupling in diabatic perspective: A multi-state density functional theory study

NASA Astrophysics Data System (ADS)

Guo, Xinwei; Qu, Zexing; Gao, Jiali

2018-01-01

The multi-state density functional theory (MSDFT) provides a convenient way to estimate electronic coupling of charge transfer processes based on a diabatic representation. Its performance has been benchmarked against the HAB11 database with a mean unsigned error (MUE) of 17 meV between MSDFT and ab initio methods. The small difference may be attributed to different representations, diabatic from MSDFT and adiabatic from ab initio calculations. In this discussion, we conclude that MSDFT provides a general and efficient way to estimate the electronic coupling for charge-transfer rate calculations based on the Marcus-Hush model.

Molecular dynamics simulation of the ionic liquid N-octylpyridinium tetrafluoroborate and acetonitrile: Thermodynamic and structural properties

NASA Astrophysics Data System (ADS)

Zhou, Siwen; Zhu, Guanglai; Kang, Xianqu; Li, Qiang; Sha, Maolin; Cui, Zhifeng; Xu, Xinsheng

2018-06-01

Using molecular dynamics simulation, the research obtained the thermodynamic properties and microstructures of the mixture of N-octylpyridinium tetrafluoroborate and acetonitrile, including density, self-diffusion coefficients, excess properties, radial distribution functions (RDFs) and spatial distribution functions (SDFs). Both RDFs and SDFs indicate that the local microstructure of the polar region is different from the nonpolar region with different mole fraction of ionic liquids. Acetonitrile could increase the order of the polar regions. While with acetonitrile increasing, the orderliness of the nonpolar region increases firstly and then decreases. In relatively dilute solution, ionic liquids were dispersed to form small aggregates wrapped by acetonitrile.

The social welfare function and individual responsibility: some theoretical issues and empirical evidence.

PubMed

Dolan, Paul; Tsuchiya, Aki

2009-01-01

The literature on income distribution has attempted to evaluate different degrees of inequality using a social welfare function (SWF) approach. However, it has largely ignored the source of such inequalities, and has thus failed to consider different degrees of inequity. The literature on egalitarianism has addressed issues of equity, largely in relation to individual responsibility. This paper builds upon these two literatures, and introduces individual responsibility into the SWF. Results from a small-scale study of people's preferences in relation to the distribution of health benefits are presented to illustrate how the parameter values of a SWF might be determined.

Movement rehabilitation: are the principles of re-learning in the recovery of function the same as those of original learning?

PubMed

Newell, Karl M; Verhoeven, F Martijn

2017-01-01

This paper addresses the change in movement dynamics in rehabilitation through discussing issues that pertain to the question as to whether the principles of re-learning in functional recovery are the same as those of original learning. The many varieties of disease and injury states lead to significant differences in the constraints to action and these impairments in turn influence the pathway of change in re-learning and/or recovery of function. These altered constraints channel the effectiveness of many conditions and strategies of practice that influence learning and performance. Nevertheless, it is proposed that there is a small set of principles for the change in dynamics of motor learning, which drive the continuously evolving stability and instability of movement forms through the lifespan. However, this common set of dynamical principles is realized in individual pathways of change in the movement dynamics of learning, re-learning and recovery of function. The inherent individual differences of humans and environments insure that the coordination, control and skill of movement rehabilitation are challenged in distinct ways by the changing constraints arising from the many manifestations of disease and injury. Implications for rehabilitation The many varieties of disease and injury states lead to significant differences in the constraints to action that in turn influence the pathway of change in re-learning and/or recovery of function, and the effectiveness of the many conditions/strategies of practice to influence learning and performance. There are a small set of principles for the change in dynamics of motor learning that drive the continuously evolving ebb and flow of stability and instability of movement forms through the lifespan. The inherent individual differences of humans and environments insure that the coordination, control and skill of movement rehabilitation are uniquely challenged by the changing constraints arising from the many manifestations of disease and injury.

Development and application of a quantitative multiplexed small GTPase activity assay using targeted proteomics.

PubMed

Zhang, Cheng-Cheng; Li, Ru; Jiang, Honghui; Lin, Shujun; Rogalski, Jason C; Liu, Kate; Kast, Juergen

2015-02-06

Small GTPases are a family of key signaling molecules that are ubiquitously expressed in various types of cells. Their activity is often analyzed by western blot, which is limited by its multiplexing capability, the quality of isoform-specific antibodies, and the accuracy of quantification. To overcome these issues, a quantitative multiplexed small GTPase activity assay has been developed. Using four different binding domains, this assay allows the binding of up to 12 active small GTPase isoforms simultaneously in a single experiment. To accurately quantify the closely related small GTPase isoforms, a targeted proteomic approach, i.e., selected/multiple reaction monitoring, was developed, and its functionality and reproducibility were validated. This assay was successfully applied to human platelets and revealed time-resolved coactivation of multiple small GTPase isoforms in response to agonists and differential activation of these isoforms in response to inhibitor treatment. This widely applicable approach can be used for signaling pathway studies and inhibitor screening in many cellular systems.

Noise of the Harrier in vertical landing and takeoff

NASA Technical Reports Server (NTRS)

Soderman, Paul T.; Foster, John D.

1988-01-01

The noise of the Harrier AV8C aircraft in vertical takeoff and landing was measured 100 feet to the side of the aircraft where jet noise dominates. The noise levels were quite high - up to 125 dB overall sound level at 100 feet. The increased noise due to jet impingement on the ground is presented as a function of jet height to diameter ratio. The impingement noise with the aircraft close to the ground was 14 to 17 dB greater than noise from a free jet. Results are compared with small-scale jet impingement data acquired elsewhere. The agreement between small-scale and full-scale noise increase in ground effect is fairly good except with the jet close to the ground. It is proposed that differences in the jet Reynolds numbers and the resultant character of the jets may be partially responsible for the disparity in the full-scale and small-scale jet impingement noise. The difference between single-jet impingement and multiple-jet impingement may also have been responsible for the small-scale and full-scale disagreement.

Emerging Role of CRISPR/Cas9 Technology for MicroRNAs Editing in Cancer Research.

PubMed

Aquino-Jarquin, Guillermo

2017-12-15

MicroRNAs (miRNA) are small, noncoding RNA molecules with a master role in the regulation of important tasks in different critical processes of cancer pathogenesis. Because there are different miRNAs implicated in all the stages of cancer, for example, functioning as oncogenes, this makes these small molecules suitable targets for cancer diagnosis and therapy. RNA-mediated interference has been one major approach for sequence-specific regulation of gene expression in eukaryotic organisms. Recently, the CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system, first identified in bacteria and archaea as an adaptive immune response to invading genetic material, has been explored as a sequence-specific molecular tool for editing genomic sequences for basic research in life sciences and for therapeutic purposes. There is growing evidence that small noncoding RNAs, including miRNAs, can be targeted by the CRISPR/Cas9 system despite their lacking an open reading frame to evaluate functional loss. Thus, CRISPR/Cas9 technology represents a novel gene-editing strategy with compelling robustness, specificity, and stability for the modification of miRNA expression. Here, I summarize key features of current knowledge of genomic editing by CRISPR/Cas9 technology as a feasible strategy for globally interrogating miRNA gene function and miRNA-based therapeutic intervention. Alternative emerging strategies for nonviral delivery of CRISPR/Cas9 core components into human cells in a clinical context are also analyzed critically. Cancer Res; 77(24); 6812-7. ©2017 AACR . ©2017 American Association for Cancer Research.

Hydrologic, Ecologic and Livelihood Impact Assessment of a System of Small Reservoirs in Ghana

NASA Astrophysics Data System (ADS)

Gao, Y.; Vogel, R. M.; Kirshen, P. H.; Walker, P.

2012-12-01

In Ghana, the short rainy season is marked by large fluctuations in arrival time, duration and intensity of rainfall, resulting in large inter-year variations in river flow and water availability. Many small reservoirs are built to deal with this variation by providing storage of water in the rainy season. This water is then used during the dry season for various activities, such as small-scale irrigation, domestic uses and livestock watering, to improve livelihood. However, small reservoir development has been made in a spontaneous fashion without concern for their integrated impacts and many of them have deteriorated over time due to poor maintenance. This is further confounded by the lack of a complete inventory of the reservoirs, because their construction was funded by different agencies, at different times, with little coordinated effort among the agencies to facilitate a regional optimization of investments. When an individual small reservoir is considered, alteration to the entire watershed is not significant. However, when considered as a system, together the small reservoirs store a significant quantity of water and influence downstream flows. The small reservoirs have rarely been considered as a system, thus little consideration has been given to their collective impact on the environment and livelihoods of the local population in the long term. Furthermore, the impact is difficult to quantify given the diffuse nature of the small reservoirs. Therefore, this study was set up to investigate the effect of the small reservoirs as a system, and intended to contribute to the limited number of studies available in literature on small reservoirs in developing countries. Using data collected in the Upper East Region of Ghana in 2007 and 2008, hydrological modeling, statistical analyses and institutional analyses were conducted to 1) assess the hydrologic, ecologic and livelihood impact of a large ensemble of small reservoirs; 2) formulate appropriate water policy and planning strategies if any negative impact is found; and 3) provide recommendation on management of small reservoirs with the goal of improving livelihoods. Results from the study show that the current level of small reservoirs development has very low impact on the flow regime in the watershed and that the small reservoirs have not caused any change to the ecosystem in the study area. Small reservoirs can have positive impacts on the farmers' livelihood, but there are issues with the functioning of the water users association (WUA), which an entity established to manage the small reservoirs. Capacity building should be given to the WUA to strengthen its operation, and monitoring of the performance of the WUA and its executive board should be conducted by the Ministry of Food and Agriculture or the funding agency to ensure that the WUA is functioning in a participatory and fair way.

Think locally, act locally: detection of small, medium-sized, and large communities in large networks.

PubMed

Jeub, Lucas G S; Balachandran, Prakash; Porter, Mason A; Mucha, Peter J; Mahoney, Michael W

2015-01-01

It is common in the study of networks to investigate intermediate-sized (or "meso-scale") features to try to gain an understanding of network structure and function. For example, numerous algorithms have been developed to try to identify "communities," which are typically construed as sets of nodes with denser connections internally than with the remainder of a network. In this paper, we adopt a complementary perspective that communities are associated with bottlenecks of locally biased dynamical processes that begin at seed sets of nodes, and we employ several different community-identification procedures (using diffusion-based and geodesic-based dynamics) to investigate community quality as a function of community size. Using several empirical and synthetic networks, we identify several distinct scenarios for "size-resolved community structure" that can arise in real (and realistic) networks: (1) the best small groups of nodes can be better than the best large groups (for a given formulation of the idea of a good community); (2) the best small groups can have a quality that is comparable to the best medium-sized and large groups; and (3) the best small groups of nodes can be worse than the best large groups. As we discuss in detail, which of these three cases holds for a given network can make an enormous difference when investigating and making claims about network community structure, and it is important to take this into account to obtain reliable downstream conclusions. Depending on which scenario holds, one may or may not be able to successfully identify "good" communities in a given network (and good communities might not even exist for a given community quality measure), the manner in which different small communities fit together to form meso-scale network structures can be very different, and processes such as viral propagation and information diffusion can exhibit very different dynamics. In addition, our results suggest that, for many large realistic networks, the output of locally biased methods that focus on communities that are centered around a given seed node (or set of seed nodes) might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate structural properties that are important to consider in the development of better benchmark networks to test methods for community detection.

Think Locally, Act Locally: The Detection of Small, Medium-Sized, and Large Communities in Large Networks

PubMed Central

Jeub, Lucas G. S.; Balachandran, Prakash; Porter, Mason A.; Mucha, Peter J.; Mahoney, Michael W.

2016-01-01

It is common in the study of networks to investigate intermediate-sized (or “meso-scale”) features to try to gain an understanding of network structure and function. For example, numerous algorithms have been developed to try to identify “communities,” which are typically construed as sets of nodes with denser connections internally than with the remainder of a network. In this paper, we adopt a complementary perspective that “communities” are associated with bottlenecks of locally-biased dynamical processes that begin at seed sets of nodes, and we employ several different community-identification procedures (using diffusion-based and geodesic-based dynamics) to investigate community quality as a function of community size. Using several empirical and synthetic networks, we identify several distinct scenarios for “size-resolved community structure” that can arise in real (and realistic) networks: (i) the best small groups of nodes can be better than the best large groups (for a given formulation of the idea of a good community); (ii) the best small groups can have a quality that is comparable to the best medium-sized and large groups; and (iii) the best small groups of nodes can be worse than the best large groups. As we discuss in detail, which of these three cases holds for a given network can make an enormous difference when investigating and making claims about network community structure, and it is important to take this into account to obtain reliable downstream conclusions. Depending on which scenario holds, one may or may not be able to successfully identify “good” communities in a given network (and good communities might not even exist for a given community quality measure), the manner in which different small communities fit together to form meso-scale network structures can be very different, and processes such as viral propagation and information diffusion can exhibit very different dynamics. In addition, our results suggest that, for many large realistic networks, the output of locally-biased methods that focus on communities that are centered around a given seed node might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate subtler structural properties that are important to consider in the development of better benchmark networks to test methods for community detection. PMID:25679670

Think locally, act locally: Detection of small, medium-sized, and large communities in large networks

NASA Astrophysics Data System (ADS)

Jeub, Lucas G. S.; Balachandran, Prakash; Porter, Mason A.; Mucha, Peter J.; Mahoney, Michael W.

2015-01-01

It is common in the study of networks to investigate intermediate-sized (or "meso-scale") features to try to gain an understanding of network structure and function. For example, numerous algorithms have been developed to try to identify "communities," which are typically construed as sets of nodes with denser connections internally than with the remainder of a network. In this paper, we adopt a complementary perspective that communities are associated with bottlenecks of locally biased dynamical processes that begin at seed sets of nodes, and we employ several different community-identification procedures (using diffusion-based and geodesic-based dynamics) to investigate community quality as a function of community size. Using several empirical and synthetic networks, we identify several distinct scenarios for "size-resolved community structure" that can arise in real (and realistic) networks: (1) the best small groups of nodes can be better than the best large groups (for a given formulation of the idea of a good community); (2) the best small groups can have a quality that is comparable to the best medium-sized and large groups; and (3) the best small groups of nodes can be worse than the best large groups. As we discuss in detail, which of these three cases holds for a given network can make an enormous difference when investigating and making claims about network community structure, and it is important to take this into account to obtain reliable downstream conclusions. Depending on which scenario holds, one may or may not be able to successfully identify "good" communities in a given network (and good communities might not even exist for a given community quality measure), the manner in which different small communities fit together to form meso-scale network structures can be very different, and processes such as viral propagation and information diffusion can exhibit very different dynamics. In addition, our results suggest that, for many large realistic networks, the output of locally biased methods that focus on communities that are centered around a given seed node (or set of seed nodes) might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate structural properties that are important to consider in the development of better benchmark networks to test methods for community detection.

Discharge-related trends in the composition of particulate organic matter exported by small mountainous rivers: results from Oregon and California (Invited)

NASA Astrophysics Data System (ADS)

Goni, M. A.; Hatten, J. A.; Wheatcroft, R. A.; Borgeld, J.; Williamson, A.; Padgett, J.; Pasternack, G. B.; Gray, A.; Watson, E. B.

2009-12-01

Small mountainous rivers display highly variable discharges on both seasonal and event scales. Previous work has shown marked differences in the composition of the particulate load of rivers collected at different stages of the hydrograph, but fewer studies have specifically investigated how the biogeochemical compositions of particulate organic matter change as a function of discharge and how this variation affects the characteristics of the materials reaching the ocean. We explore these issues using data from three rivers along the west coast of the U.S. (Umpqua, Eel and Salinas) with similar watershed size but contrasting climate, vegetation and land use. Coarse and fine particulate organic matter samples collected at different discharges, including several flood events, were analyzed for carbon and nitrogen content, stable carbon and nitrogen isotopic compositions, radiocarbon compositions and yields of different organic biomarkers (e.g. lignin phenols, cutin acids, amino acid products). This presentation will focus on comparing and contrasting the provenance, age, and biochemical make-up of materials transported by each of the rivers as a function of discharge. Seasonal and event-scale differences in organic matter concentrations and compositions will be the subject of an accompanying poster. We will discuss both the processes responsible for these contrasts and the impacts they have on the delivery and fate of terrigenous organic matter in the coastal ocean.

A family of small-world network models built by complete graph and iteration-function

NASA Astrophysics Data System (ADS)

Ma, Fei; Yao, Bing

2018-02-01

Small-world networks are popular in real-life complex systems. In the past few decades, researchers presented amounts of small-world models, in which some are stochastic and the rest are deterministic. In comparison with random models, it is not only convenient but also interesting to study the topological properties of deterministic models in some fields, such as graph theory, theorem computer sciences and so on. As another concerned darling in current researches, community structure (modular topology) is referred to as an useful statistical parameter to uncover the operating functions of network. So, building and studying such models with community structure and small-world character will be a demanded task. Hence, in this article, we build a family of sparse network space N(t) which is different from those previous deterministic models. Even though, our models are established in the same way as them, iterative generation. By randomly connecting manner in each time step, every resulting member in N(t) has no absolutely self-similar feature widely shared in a large number of previous models. This makes our insight not into discussing a class certain model, but into investigating a group various ones spanning a network space. Somewhat surprisingly, our results prove all members of N(t) to possess some similar characters: (a) sparsity, (b) exponential-scale feature P(k) ∼α-k, and (c) small-world property. Here, we must stress a very screming, but intriguing, phenomenon that the difference of average path length (APL) between any two members in N(t) is quite small, which indicates this random connecting way among members has no great effect on APL. At the end of this article, as a new topological parameter correlated to reliability, synchronization capability and diffusion properties of networks, the number of spanning trees on a representative member NB(t) of N(t) is studied in detail, then an exact analytical solution for its spanning trees entropy is also obtained.

A microstructural comparison of two nuclear-grade martensitic steels using small-angle neutron scattering

NASA Astrophysics Data System (ADS)

Coppola, R.; Fiori, F.; Little, E. A.; Magnani, M.

1997-06-01

Results are presented of a small-angle neutron scattering (SANS) study on two 10-13% Cr martensitic stainless steels of interest for nuclear applications, viz. DIN 1.4914 (MANET specification, for fusion reactors) and AISI 410. The investigation has focussed principally on microstructural effects associated with the differences in chromium content between the two alloys. The size distribution functions determined from nuclear and magnetic SANS components for the two steels given identical heat treatments are in accord with an interpretation based on the presence of ˜ 1 nm size CCr aggregates in the microstructure. Much larger (˜ 10 nm) scattering inhomogeneities with different magnetic contrast are also present and tentatively identified as carbides.

Sex/Gender Differences in Neural Correlates of Food Stimuli: A Systematic Review of Functional Neuroimaging Studies

PubMed Central

Chao, Ariana M.; Loughead, James; Bakizada, Zayna M.; Hopkins, Christina M.; Geliebter, Allan; Gur, Ruben C.; Wadden, Thomas A.

2017-01-01

Sex and gender differences in food perceptions and eating behaviors have been reported in psychological and behavioral studies. The aim of this systematic review was to synthesize studies that examined sex/gender differences in neural correlates of food stimuli, as assessed by functional neuroimaging. Published studies to 2016 were retrieved and included if they used food or eating stimuli, assessed patients with functional magnetic resonance imaging (fMRI) or positron emission tomography (PET), and compared activation between males and females. Fifteen studies were identified. In response to visual food cues, females, compared to males, showed increased activation in the frontal, limbic, and striatal areas of the brain as well as the fusiform gyrus. Differences in neural response to gustatory stimuli were inconsistent. This body of literature suggests that females may be more reactive to visual food stimuli. However, findings are based on a small number of studies and additional research is needed to establish a more definitive explanation and conclusion. PMID:28371180

Structure of spherical electric double layers with fully asymmetric electrolytes: a systematic study by Monte Carlo simulations and density functional theory.

PubMed

Patra, Chandra N

2014-11-14

A systematic investigation of the spherical electric double layers with the electrolytes having size as well as charge asymmetry is carried out using density functional theory and Monte Carlo simulations. The system is considered within the primitive model, where the macroion is a structureless hard spherical colloid, the small ions as charged hard spheres of different size, and the solvent is represented as a dielectric continuum. The present theory approximates the hard sphere part of the one particle correlation function using a weighted density approach whereas a perturbation expansion around the uniform fluid is applied to evaluate the ionic contribution. The theory is in quantitative agreement with Monte Carlo simulation for the density and the mean electrostatic potential profiles over a wide range of electrolyte concentrations, surface charge densities, valence of small ions, and macroion sizes. The theory provides distinctive evidence of charge and size correlations within the electrode-electrolyte interface in spherical geometry.

A Systematic Review and Meta-Analysis of Yoga and Mindfulness Meditation in Prison.

PubMed

Auty, Katherine M; Cope, Aiden; Liebling, Alison

2017-05-01

This article presents results from a systematic review and two meta-analyses that examine whether prison yoga and meditation programs are significantly related to increased psychological well-being and improvements in the behavioural functioning of prisoners. Comprehensive searches of the empirical literature were conducted up to December 2014. Participants who completed yoga or meditation program in prison experienced a small increase in their psychological well-being (Cohen's d = 0.46, 95% confidence interval [CI] = [0.39, 0.54]) and a small improvement in their behavioural functioning (Cohen's d = 0.30, 95% CI = [0.20, 0.40]). Moderator analyses suggested that there was a significant difference in effect sizes for programs of longer duration and less intensity, compared with those that were shorter and more intensive, for psychological well-being. Programs of longer duration had a slightly larger positive effect on behavioural functioning ( d = 0.424), compared with more intensive programs ( d = 0.418). Overall, the evidence suggests that yoga and meditation have favourable effects on prisoners.

psRNATarget: a plant small RNA target analysis server

PubMed Central

Dai, Xinbin; Zhao, Patrick Xuechun

2011-01-01

Plant endogenous non-coding short small RNAs (20–24 nt), including microRNAs (miRNAs) and a subset of small interfering RNAs (ta-siRNAs), play important role in gene expression regulatory networks (GRNs). For example, many transcription factors and development-related genes have been reported as targets of these regulatory small RNAs. Although a number of miRNA target prediction algorithms and programs have been developed, most of them were designed for animal miRNAs which are significantly different from plant miRNAs in the target recognition process. These differences demand the development of separate plant miRNA (and ta-siRNA) target analysis tool(s). We present psRNATarget, a plant small RNA target analysis server, which features two important analysis functions: (i) reverse complementary matching between small RNA and target transcript using a proven scoring schema, and (ii) target-site accessibility evaluation by calculating unpaired energy (UPE) required to ‘open’ secondary structure around small RNA’s target site on mRNA. The psRNATarget incorporates recent discoveries in plant miRNA target recognition, e.g. it distinguishes translational and post-transcriptional inhibition, and it reports the number of small RNA/target site pairs that may affect small RNA binding activity to target transcript. The psRNATarget server is designed for high-throughput analysis of next-generation data with an efficient distributed computing back-end pipeline that runs on a Linux cluster. The server front-end integrates three simplified user-friendly interfaces to accept user-submitted or preloaded small RNAs and transcript sequences; and outputs a comprehensive list of small RNA/target pairs along with the online tools for batch downloading, key word searching and results sorting. The psRNATarget server is freely available at http://plantgrn.noble.org/psRNATarget/. PMID:21622958

Decreased Functional Brain Connectivity in Adolescents with Internet Addiction

PubMed Central

Hong, Soon-Beom; Zalesky, Andrew; Cocchi, Luca; Fornito, Alex; Choi, Eun-Jung; Kim, Ho-Hyun; Suh, Jeong-Eun; Kim, Chang-Dai; Kim, Jae-Won; Yi, Soon-Hyung

2013-01-01

Background Internet addiction has become increasingly recognized as a mental disorder, though its neurobiological basis is unknown. This study used functional neuroimaging to investigate whole-brain functional connectivity in adolescents diagnosed with internet addiction. Based on neurobiological changes seen in other addiction related disorders, it was predicted that connectivity disruptions in adolescents with internet addiction would be most prominent in cortico-striatal circuitry. Methods Participants were 12 adolescents diagnosed with internet addiction and 11 healthy comparison subjects. Resting-state functional magnetic resonance images were acquired, and group differences in brain functional connectivity were analyzed using the network-based statistic. We also analyzed network topology, testing for between-group differences in key graph-based network measures. Results Adolescents with internet addiction showed reduced functional connectivity spanning a distributed network. The majority of impaired connections involved cortico-subcortical circuits (∼24% with prefrontal and ∼27% with parietal cortex). Bilateral putamen was the most extensively involved subcortical brain region. No between-group difference was observed in network topological measures, including the clustering coefficient, characteristic path length, or the small-worldness ratio. Conclusions Internet addiction is associated with a widespread and significant decrease of functional connectivity in cortico-striatal circuits, in the absence of global changes in brain functional network topology. PMID:23451272

Thermal Fluxes and Temperatures in Small Urban Headwater Streams of the BES LTER: Landscape Forest and Impervious Patches and the Importance of Spatial and Temporal Scales

NASA Astrophysics Data System (ADS)

Kim, H.; Belt, K. T.; Welty, C.; Heisler, G.; Pouyat, R. V.; McGuire, M. P.; Stack, W. P.

2006-05-01

Water and material fluxes from urban landscape patches to small streams are modulated by extensive "engineered" drainage networks. Small urban headwater catchments are different in character and function from their larger receiving streams because of their extensive, direct connections to impervious surface cover (ISC) and their sometimes buried nature. They need to be studied as unique functional hydrologic units if impacts on biota are to be fully understood. As part of the Baltimore Ecosystem Study LTER project, continuous water temperature data are being collected at 2-minute intervals at over twenty small catchments representing various mixtures of forest and ISC. Suburban stream sites with greater ISC generally have higher summer water temperatures. Suburban catchments with most of their channel drainage contained within storm drain pipes show subdued diurnal variation and cool temperatures, but with very large spikes in summer runoff events. Conversely, high ISC urban piped streams have elevated "baseline" temperatures that stand well above all the other monitoring sites. There is a pronounced upstream-downstream effect; nested small headwater catchments experience more frequent, larger temperature spikes related to runoff events than downstream sites. Also, runoff-initiated temperature elevations at small stream sites unexpectedly last much longer than the storm runoff hydrographs. These observations suggest that for small headwater catchments, urban landscapes not only induce an ambient, "heat island" effect on stream temperatures, but also introduce thermal disturbance regimes and fluxes that are not trivial to aquatic biota.

Diversity and functional convergence of small noncoding RNAs in male germ cell differentiation and fertilization

PubMed Central

García-López, Jesús; Alonso, Lola; Cárdenas, David B.; Artaza-Alvarez, Haydeé; Hourcade, Juan de Dios; Martínez, Sergio; Brieño-Enríquez, Miguel A.; del Mazo, Jesús

2015-01-01

The small noncoding RNAs (sncRNAs) are considered as post-transcriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs, or rRNAs processing may also play important regulatory roles in spermatogenesis. By next-generation sequencing (NGS), we characterized the sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs), pubertal spermatogonia cells, and mature spermatozoa. To assess their potential transmission through the spermatozoa during fertilization, the sncRNAs of mouse oocytes and zygotes were also analyzed. Both, microRNAs and snoRNA-derived small RNAs are abundantly expressed in PGCs but transiently replaced by piRNAs in spermatozoa and endo-siRNAs in oocytes and zygotes. Exhaustive analysis of miRNA sequence variants also shows an increment of noncanonical microRNA forms along male germ cell differentiation. RNAs-derived from tRNAs and rRNAs interacting with PIWI proteins are not generated by the ping-pong pathway and could be a source of primary piRNAs. Moreover, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. Finally, computational analysis revealed their potential involvement in post-transcriptional regulation of mRNA transcripts suggesting functional convergence among different small RNA classes in germ cells and zygotes. PMID:25805854

Density functional theory and an experimentally-designed energy functional of electron density.

PubMed

Miranda, David A; Bueno, Paulo R

2016-09-21

We herein demonstrate that capacitance spectroscopy (CS) experimentally allows access to the energy associated with the quantum mechanical ground state of many-electron systems. Priorly, electrochemical capacitance, C [small mu, Greek, macron] [ρ], was previously understood from conceptual and computational density functional theory (DFT) calculations. Thus, we herein propose a quantum mechanical experiment-based variational method for electron charging processes based on an experimentally-designed functional of the ground state electron density. In this methodology, the electron state density, ρ, and an energy functional of the electron density, E [small mu, Greek, macron] [ρ], can be obtained from CS data. CS allows the derivative of the electrochemical potential with respect to the electron density, (δ[small mu, Greek, macron][ρ]/δρ), to be obtained as a unique functional of the energetically minimised system, i.e., β/C [small mu, Greek, macron] [ρ], where β is a constant (associated with the size of the system) and C [small mu, Greek, macron] [ρ] is an experimentally observable quantity. Thus the ground state energy (at a given fixed external potential) can be obtained simply as E [small mu, Greek, macron] [ρ], from the experimental measurement of C [small mu, Greek, macron] [ρ]. An experimental data-set was interpreted to demonstrate the potential of this quantum mechanical experiment-based variational principle.

Function of Protein Phosphatase 2A in Control of Proliferation: Isolation and Analysis of Dominant-Defective Mutants

DTIC Science & Technology

1999-06-01

subunits are expressed ubiquitously and appear to be encoded by small and quite homogeneous gene families. In plants , however, A and C subunit gene...1996). In both plants and animals, different B subunit isoforms are encoded by two or more unrelated gene families, some of which are expressed in a...PP2A functions in whole plants and in mammalian tissue culture cells. This genetic system may also prove useful for analyzing interactions between

Lensing of the CMB: non-Gaussian aspects.

PubMed

Zaldarriaga, M

2001-06-01

We compute the small angle limit of the three- and four-point function of the cosmic microwave background (CMB) temperature induced by the gravitational lensing effect by the large-scale structure of the universe. We relate the non-Gaussian aspects presented in this paper with those in our previous studies of the lensing effects. We interpret the statistics proposed in previous work in terms of different configurations of the four-point function and show how they relate to the statistic that maximizes the S/N.

One and two hydrogen molecules in the large cage of the structure II clathrate hydrate: quantum translation-rotation dynamics close to the cage wall.

PubMed

Sebastianelli, Francesco; Xu, Minzhong; Kanan, Dalal K; Bacić, Zlatko

2007-07-19

We have performed a rigorous theoretical study of the quantum translation-rotation (T-R) dynamics of one and two H2 and D2 molecules confined inside the large hexakaidecahedral (5(12)6(4)) cage of the sII clathrate hydrate. For a single encapsulated H2 and D2 molecule, accurate quantum five-dimensional calculations of the T-R energy levels and wave functions are performed that include explicitly, as fully coupled, all three translational and the two rotational degrees of freedom of the hydrogen molecule, while the cage is taken to be rigid. In addition, the ground-state properties, energetics, and spatial distribution of one and two p-H2 and o-D2 molecules in the large cage are calculated rigorously using the diffusion Monte Carlo method. These calculations reveal that the low-energy T-R dynamics of hydrogen molecules in the large cage are qualitatively different from that inside the small cage, studied by us recently. This is caused by the following: (i) The large cage has a cavity whose diameter is about twice that of the small cage for the hydrogen molecule. (ii) In the small cage, the potential energy surface (PES) for H2 is essentially flat in the central region, while in the large cage the PES has a prominent maximum at the cage center, whose height exceeds the T-R zero-point energy of H2/D2. As a result, the guest molecule is excluded from the central part of the large cage, its wave function localized around the off-center global minimum. Peculiar quantum dynamics of the hydrogen molecule squeezed between the central maximum and the cage wall manifests in the excited T-R states whose energies and wave functions differ greatly from those for the small cage. Moreover, they are sensitive to the variations in the hydrogen-bonding topology, which modulate the corrugation of the cage wall.

Functional and phylogenetic structure of island bird communities.

PubMed

Si, Xingfeng; Cadotte, Marc W; Zeng, Di; Baselga, Andrés; Zhao, Yuhao; Li, Jiaqi; Wu, Yiru; Wang, Siyu; Ding, Ping

2017-05-01

Biodiversity change in anthropogenically transformed habitats is often nonrandom, yet the nature and importance of the different mechanisms shaping community structure are unclear. Here, we extend the classic Theory of Island Biogeography (TIB) to account for nonrandom processes by incorporating species traits and phylogenetic relationships into a study of faunal relaxation following habitat loss and fragmentation. Two possible mechanisms can create nonrandom community patterns on fragment islands. First, small and isolated islands might consist of similar or closely related species because they are environmentally homogeneous or select for certain shared traits, such as dispersal ability. Alternatively, communities on small islands might contain more dissimilar or distantly related species than on large islands because limited space and resource availability result in greater competitive exclusion among species with high niche overlap. Breeding birds were surveyed on 36 islands and two mainland sites annually from 2010 to 2014 in the Thousand Island Lake region, China. We assessed community structure of breeding birds on these subtropical land-bridge islands by integrating species' trait and evolutionary distances. We additionally analysed habitat heterogeneity and variance in size ratios to distinguish biotic and abiotic processes of community assembly. Results showed that functional-phylogenetic diversity increased with island area, and decreased with isolation. Bird communities on the mainland were more diverse and generally less clustered than island bird communities and not different than randomly assembled communities. Bird communities on islands tend to be functionally similar and phylogenetically clustered, especially on small and isolated islands. The nonrandom decline in species diversity and change in bird community structure with island area and isolation, along with the relatively homogeneous habitats on small islands, support the environmental filtering hypothesis. Our study demonstrates the importance of integrating multiple forms of diversity for understanding the effects of habitat loss and fragmentation, and further reveals that TIB could be extended to community measures by moving beyond assumptions of species equivalency in colonisation rates and extinction susceptibilities. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Associations between education and physical functioning and pain in adult Danish cancer survivors.

PubMed

Winther, Dorte; Nygaard, Tina K; Horsbøl, Trine A; Kjær, Trille; Vedsted, Peter; Johansen, Christoffer; Hovaldt, Hanna B; Sandager, Mette; Dalton, Susanne O

2017-02-01

Late effects after cancer diagnosis and treatment are common, but only few studies have examined the role of social factors in developing these late effects. The aim of this study was to examine the association between educational level and physical function and pain among cancer survivors two years after diagnosis. The study population consisted of adult Danish patients with a first-time cancer diagnosis who were sent a questionnaire in 2010 and followed up in 2012. In total, 4346 returned the first questionnaire shortly after diagnosis and 2568 returned the follow-up questionnaire. After exclusion of 177 due to missing information, we included 2391 cancer survivors in the analyses. Physical function and pain were measured using the EORTC QLQ-C30. Linear regression analyses were conducted separately for men and women, and adjusted for demographic and clinical characteristics. Additionally, analyses were stratified on comorbidity. Differences in mean scores according to educational level were small. Physical function was better in women with medium (2.8; 95% CI 0.1;5.4) and higher education (3.4; 95% CI 0.9;5.9) compared to women with short education. In contrast, men with medium education reported lower physical function (-2.9; 95% CI -5.7;-0.1) than men with short education. Compared to women with short education, we found lower pain scores among women with medium (-5.0; 95% CI -8.7;-1.4) and higher education (-3.4; 95% CI -6.7;0.0). Similarly, men with higher education experienced lower pain score (-3.4; 95% CI -6.9;0.1) than men with short education. The role of educational level differed between those with and without comorbidity. Educational level is slightly associated with physical function and pain among cancer survivors. However, mean differences in this study were small and below what is considered clinically relevant.

Histogram contrast analysis and the visual segregation of IID textures.

PubMed

Chubb, C; Econopouly, J; Landy, M S

1994-09-01

A new psychophysical methodology is introduced, histogram contrast analysis, that allows one to measure stimulus transformations, f, used by the visual system to draw distinctions between different image regions. The method involves the discrimination of images constructed by selecting texture micropatterns randomly and independently (across locations) on the basis of a given micropattern histogram. Different components of f are measured by use of different component functions to modulate the micropattern histogram until the resulting textures are discriminable. When no discrimination threshold can be obtained for a given modulating component function, a second titration technique may be used to measure the contribution of that component to f. The method includes several strong tests of its own assumptions. An example is given of the method applied to visual textures composed of small, uniform squares with randomly chosen gray levels. In particular, for a fixed mean gray level mu and a fixed gray-level variance sigma 2, histogram contrast analysis is used to establish that the class S of all textures composed of small squares with jointly independent, identically distributed gray levels with mean mu and variance sigma 2 is perceptually elementary in the following sense: there exists a single, real-valued function f S of gray level, such that two textures I and J in S are discriminable only if the average value of f S applied to the gray levels in I is significantly different from the average value of f S applied to the gray levels in J. Finally, histogram contrast analysis is used to obtain a seventh-order polynomial approximation of f S.

Attack risk for butterflies changes with eyespot number and size

PubMed Central

Ho, Sebastian; Schachat, Sandra R.; Piel, William H.; Monteiro, Antónia

2016-01-01

Butterfly eyespots are known to function in predator deflection and predator intimidation, but it is still unclear what factors cause eyespots to serve one function over the other. Both functions have been demonstrated in different species that varied in eyespot size, eyespot number and wing size, leaving the contribution of each of these factors to butterfly survival unclear. Here, we study how each of these factors contributes to eyespot function by using paper butterfly models, where each factor is varied in turn, and exposing these models to predation in the field. We find that the presence of multiple, small eyespots results in high predation, whereas single large eyespots (larger than 6 mm in diameter) results in low predation. These data indicate that single large eyespots intimidate predators, whereas multiple small eyespots produce a conspicuous, but non-intimidating signal to predators. We propose that eyespots may gain an intimidation function by increasing in size. Our measurements of eyespot size in 255 nymphalid butterfly species show that large eyespots are relatively rare and occur predominantly on ventral wing surfaces. By mapping eyespot size on the phylogeny of the family Nymphalidae, we show that these large eyespots, with a potential intimidation function, are dispersed throughout multiple nymphalid lineages, indicating that phylogeny is not a strong predictor of eyespot size. PMID:26909190

Altered brain functional networks in people with Internet gaming disorder: Evidence from resting-state fMRI.

PubMed

Wang, Lingxiao; Wu, Lingdan; Lin, Xiao; Zhang, Yifen; Zhou, Hongli; Du, Xiaoxia; Dong, Guangheng

2016-08-30

Although numerous neuroimaging studies have detected structural and functional abnormality in specific brain regions and connections in subjects with Internet gaming disorder (IGD), the topological organization of the whole-brain network in IGD remain unclear. In this study, we applied graph theoretical analysis to explore the intrinsic topological properties of brain networks in Internet gaming disorder (IGD). 37 IGD subjects and 35 matched healthy control (HC) subjects underwent a resting-state functional magnetic resonance imaging scan. The functional networks were constructed by thresholding partial correlation matrices of 90 brain regions. Then we applied graph-based approaches to analysis their topological attributes, including small-worldness, nodal metrics, and efficiency. Both IGD and HC subjects show efficient and economic brain network, and small-world topology. Although there was no significant group difference in global topology metrics, the IGD subjects showed reduced regional centralities in the prefrontal cortex, left posterior cingulate cortex, right amygdala, and bilateral lingual gyrus, and increased functional connectivity in sensory-motor-related brain networks compared to the HC subjects. These results imply that people with IGD may be associated with functional network dysfunction, including impaired executive control and emotional management, but enhanced coordination among visual, sensorimotor, auditory and visuospatial systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Intraspecific functional diversity of common species enhances community stability

USGS Publications Warehouse

Wood, Connor M.; McKinney, Shawn T.; Loftin, Cynthia S.

2017-01-01

Common species are fundamental to the structure and function of their communities and may enhance community stability through intraspecific functional diversity (iFD). We measured among-habitat and within-habitat iFD (i.e., among- and within-plant community types) of two common small mammal species using stable isotopes and functional trait dendrograms, determined whether iFD was related to short-term population stability and small mammal community stability, and tested whether spatially explicit trait filters helped explain observed patterns of iFD. Southern red-backed voles (Myodes gapperi) had greater iFD than deer mice (Peromyscus maniculatus), both among habitats, and within the plant community in which they were most abundant (their “primary habitat”). Peromyscus maniculatus populations across habitats differed significantly between years and declined 78% in deciduous forests, their primary habitat, as did the overall deciduous forest small mammal community. Myodes gapperi populations were stable across habitats and within coniferous forest, their primary habitat, as was the coniferous forest small mammal community. Generalized linear models representing internal trait filters (e.g., competition), which increase within-habitat type iFD, best explained variation in M. gapperidiet, while models representing internal filters and external filters (e.g., climate), which suppress within-habitat iFD, best explained P. maniculatus diet. This supports the finding that M. gapperi had higher iFD than P. maniculatus and is consistent with the theory that internal trait filters are associated with higher iFD than external filters. Common species with high iFD can impart a stabilizing influence on their communities, information that can be important for conserving biodiversity under environmental change.

Simultaneous optimization of biomolecular energy function on features from small molecules and macromolecules

PubMed Central

Park, Hahnbeom; Bradley, Philip; Greisen, Per; Liu, Yuan; Mulligan, Vikram Khipple; Kim, David E.; Baker, David; DiMaio, Frank

2017-01-01

Most biomolecular modeling energy functions for structure prediction, sequence design, and molecular docking, have been parameterized using existing macromolecular structural data; this contrasts molecular mechanics force fields which are largely optimized using small-molecule data. In this study, we describe an integrated method that enables optimization of a biomolecular modeling energy function simultaneously against small-molecule thermodynamic data and high-resolution macromolecular structural data. We use this approach to develop a next-generation Rosetta energy function that utilizes a new anisotropic implicit solvation model, and an improved electrostatics and Lennard-Jones model, illustrating how energy functions can be considerably improved in their ability to describe large-scale energy landscapes by incorporating both small-molecule and macromolecule data. The energy function improves performance in a wide range of protein structure prediction challenges, including monomeric structure prediction, protein-protein and protein-ligand docking, protein sequence design, and prediction of the free energy changes by mutation, while reasonably recapitulating small-molecule thermodynamic properties. PMID:27766851

Central obesity, leptin and cognitive decline: the Sacramento Area Latino Study on Aging.

PubMed

Zeki Al Hazzouri, Adina; Haan, Mary N; Whitmer, Rachel A; Yaffe, Kristine; Neuhaus, John

2012-01-01

Central obesity is a risk factor for cognitive decline. Leptin is secreted by adipose tissue and has been associated with better cognitive function. Aging Mexican Americans have higher levels of obesity than non-Hispanic Whites, but no investigations examined the relationship between leptin and cognitive decline among them or the role of central obesity in this association. We analyzed 1,480 dementia-free older Mexican Americans who were followed over 10 years. Cognitive function was assessed every 12-15 months with the Modified Mini Mental State Exam (3MSE) and the Spanish and English Verbal Learning Test (SEVLT). For females with a small waist circumference (≤35 inches), an interquartile range difference in leptin was associated with 35% less 3MSE errors and 22% less decline in the SEVLT score over 10 years. For males with a small waist circumference (≤40 inches), an interquartile range difference in leptin was associated with 44% less 3MSE errors and 30% less decline in the SEVLT score over 10 years. There was no association between leptin and cognitive decline among females or males with a large waist circumference. Leptin interacts with central obesity in shaping cognitive decline. Our findings provide valuable information about the effects of metabolic risk factors on cognitive function. Copyright © 2012 S. Karger AG, Basel.

Esophageal function testing using multichannel intraluminal impedance.

PubMed

Srinivasan, R; Vela, M F; Katz, P O; Tutuian, R; Castell, J A; Castell, D O

2001-03-01

Multichannel intraluminal impedance (MII) is a new technique for evaluation of bolus transport. We evaluated esophageal function using bolus transport time (BTT) and contraction wave velocity (CWV) of liquid, semisolid, and solid boluses. Ten healthy subjects underwent MII swallow evaluation with various boluses of sterile water (pH 5), applesauce, three different sized marshmallows, and iced and 130 degrees F water. The effect of bethanechol was also studied. There was no difference in BTT or CWV for all water volumes from 1 to 20 ml. There was significant linear increase of BTT with progressively larger volumes of applesauce, and BTT of applesauce was longer than for water. BTT was significantly longer with large marshmallows vs. small and medium and was longer than for water. BTT for iced water was similar to 130 degrees F water. Applesauce showed a significant linear decrease of CWV with progressively larger volumes and was slower than water. Marshmallow showed significantly slower CWV with the large vs. small, and CWV for ice water was significantly slower than 130 degrees F water. Therefore, BTT of liquid is constant, whereas BTT of semisolid and solid are volume dependent and longer than liquids. CWV of semisolids and solids are slower than liquids. CWV of cold liquids is slower than warm liquids. MII can be used as a discriminating test of esophageal function.

Determination of the structures of small gold clusters on stepped magnesia by density functional calculations.

PubMed

Damianos, Konstantina; Ferrando, Riccardo

2012-02-21

The structural modifications of small supported gold clusters caused by realistic surface defects (steps) in the MgO(001) support are investigated by computational methods. The most stable gold cluster structures on a stepped MgO(001) surface are searched for in the size range up to 24 Au atoms, and locally optimized by density-functional calculations. Several structural motifs are found within energy differences of 1 eV: inclined leaflets, arched leaflets, pyramidal hollow cages and compact structures. We show that the interaction with the step clearly modifies the structures with respect to adsorption on the flat defect-free surface. We find that leaflet structures clearly dominate for smaller sizes. These leaflets are either inclined and quasi-horizontal, or arched, at variance with the case of the flat surface in which vertical leaflets prevail. With increasing cluster size pyramidal hollow cages begin to compete against leaflet structures. Cage structures become more and more favourable as size increases. The only exception is size 20, at which the tetrahedron is found as the most stable isomer. This tetrahedron is however quite distorted. The comparison of two different exchange-correlation functionals (Perdew-Burke-Ernzerhof and local density approximation) show the same qualitative trends. This journal is © The Royal Society of Chemistry 2012

An analysis of FtsZ assembly using small angle X-ray scattering and electron microscopy.

PubMed

Kuchibhatla, Anuradha; Abdul Rasheed, A S; Narayanan, Janaky; Bellare, Jayesh; Panda, Dulal

2009-04-09

Small angle X-ray scattering (SAXS) was used for the first time to study the self-assembly of the bacterial cell division protein, FtsZ, with three different additives: calcium chloride, monosodium glutamate and DEAE-dextran hydrochloride in solution. The SAXS data were analyzed assuming a model form factor and also by a model-independent analysis using the pair distance distribution function. Transmission electron microscopy (TEM) was used for direct observation of the FtsZ filaments. By sectioning and negative staining with glow discharged grids, very high bundling as well as low bundling polymers were observed under different assembly conditions. FtsZ polymers formed different structures in the presence of different additives and these additives were found to increase the bundling of FtsZ protofilaments by different mechanisms. The combined use of SAXS and TEM provided us a significant insight of the assembly of FtsZ and microstructures of the assembled FtsZ polymers.

Selective Matrix (Hyaluronan) Interaction with CD44 and RhoGTPase Signaling Promotes Keratinocyte Functions and Overcomes Age-related Epidermal Dysfunction

PubMed Central

Bourguignon, Lilly Y.W.; Wong, Gabriel; Xia, Weiliang; Man, Mao-Qiang; Holleran, Walter M.; Elias, Peter M.

2013-01-01

Background Mouse epidermal chronologic aging is closely associated with aberrant matrix (hyaluronan, HA) -size distribution/production and impaired keratinocyte proliferation/differentiation, leading to a marked thinning of the epidermis with functional consequence that causes a slower recovery of permeability barrier function. Objective The goal of this study is to demonstrate mechanism-based, corrective therapeutic strategies using topical applications of small HA (HAS) and/or large HA (HAL) [or a sequential small HA (HAS) and large HA(HAL) (HAs-»HAL) treatment] as well as RhoGTPase signaling perturbation agents to regulate HA/CD44-mediated signaling, thereby restoring normal epidermal function, and permeability barrier homeostasis in aged mouse skin. Methods A number of biochemical, cell biological/molecular, pharmacological and physiological approaches were used to investigate matrix HA-CD44-mediated RhoGTPase signaling in regulating epidermal functions and skin aging. Results In this study we demonstrated that topical application of small HA (HAS) promotes keratinocyte proliferation and increases skin thickness, while it fails to upregulate keratinocyte differentiation or permeability barrier repair in aged mouse skin. In contrast, large HA (HAL) induces only minimal changes in keratinocyte proliferation and skin thickness, but restores keratinocyte differentiation and improves permeability barrier function in aged epidermis. Since neither HAS nor HAL corrects these epidermal defects in aged CD44 knock-out mice, CD44 likely mediates HA-associated epidermal functions in aged mouse skin. Finally, blockade of Rho-kinase activity with Y27632 or protein kinase-Nγ activity with Ro31-8220 significantly decreased the HA (HAS or HAL)-mediated changes in epidermal function in aged mouse skin. Conclusion The results of our study show first that HA application of different sizes regulates epidermal proliferation, differentiation and barrier function in aged mouse skin. Second, manipulation of matrix (HA) interaction with CD44 and RhoGTPase signaling could provide further novel therapeutic approaches that could be targeted for the treatment of various aging-related skin disorders. PMID:23790635

Involvement of Antizyme Characterized from the Small Abalone Haliotis diversicolor in Gonadal Development.

PubMed

Li, Wei-Dong; Huang, Min; Lü, Wen-Gang; Chen, Xiao; Shen, Ming-Hui; Li, Xiang-Min; Wang, Rong-Xia; Ke, Cai-Huan

2015-01-01

The small abalone Haliotis diversicolor is an economically important mollusk that is widely cultivated in Southern China. Gonad precocity may affect the aquaculture of small abalone. Polyamines, which are small cationic molecules essential for cellular proliferation, may affect gonadal development. Ornithine decarboxylase (ODC) and antizyme (AZ) are essential elements of a feedback circuit that regulates cellular polyamines. This paper presents the molecular cloning and characterization of AZ from small abalone. Sequence analysis showed that the cDNA sequence of H. diversicolor AZ (HdiODCAZ) consisted of two overlapping open reading frames (ORFs) and conformed to the +1 frameshift property of the frame. Thin Layer chromatography (TLC) analysis suggested that the expressed protein encoded by +1 ORF2 was the functional AZ that targets ODC to 26S proteasome degradation. The result demonstrated that the expression level of AZ was higher than that of ODC in the ovary of small abalone. In addition, the expression profiles of ODC and AZ at the different development stages of the ovary indicated that these two genes might be involved in the gonadal development of small abalone.

Involvement of Antizyme Characterized from the Small Abalone Haliotis diversicolor in Gonadal Development

PubMed Central

Lü, Wen-Gang; Chen, Xiao; Shen, Ming-Hui; Li, Xiang-Min; Wang, Rong-Xia; Ke, Cai-Huan

2015-01-01

The small abalone Haliotis diversicolor is an economically important mollusk that is widely cultivated in Southern China. Gonad precocity may affect the aquaculture of small abalone. Polyamines, which are small cationic molecules essential for cellular proliferation, may affect gonadal development. Ornithine decarboxylase (ODC) and antizyme (AZ) are essential elements of a feedback circuit that regulates cellular polyamines. This paper presents the molecular cloning and characterization of AZ from small abalone. Sequence analysis showed that the cDNA sequence of H. diversicolor AZ (HdiODCAZ) consisted of two overlapping open reading frames (ORFs) and conformed to the +1 frameshift property of the frame. Thin Layer chromatography (TLC) analysis suggested that the expressed protein encoded by +1 ORF2 was the functional AZ that targets ODC to 26S proteasome degradation. The result demonstrated that the expression level of AZ was higher than that of ODC in the ovary of small abalone. In addition, the expression profiles of ODC and AZ at the different development stages of the ovary indicated that these two genes might be involved in the gonadal development of small abalone. PMID:26313647

Structure factor of blends of solvent-free nanoparticle-organic hybrid materials: density-functional theory and small angle X-ray scattering.

PubMed

Yu, Hsiu-Yu; Srivastava, Samanvaya; Archer, Lynden A; Koch, Donald L

2014-12-07

We investigate the static structure factor S(q) of solvent-free nanoparticle-organic hybrid materials consisting of silica nanocores and space-filling polyethylene glycol coronas using a density-functional theory and small angle X-ray scattering measurements. The theory considers a bidisperse suspension of hard spheres with different radii and tethered bead-spring oligomers with different grafting densities to approximate the polydispersity effects in experiments. The experimental systems studied include pure samples with different silica core volume fractions and the associated mean corona grafting densities, and blends with different mixing ratios of the pure samples, in order to introduce varying polydispersity of corona grafting density. Our scattering experiments and theory show that, compared to the hard-sphere suspension with the same core volume fraction, S(q) for pure samples exhibit both substantially smaller values at small q and stronger particle correlations corresponding to a larger effective hard core at large q, indicating that the tethered incompressible oligomers enforce a more uniform particle distribution, and the densely grafted brush gives rise to an additional exclusionary effect between the nanoparticles. According to the theory, polydispersity in the oligomer grafting density controls the deviation of S(q) from the monodisperse system at smaller q, and the interplay of the enhanced effective core size and the entropic attraction among the particles is responsible for complex variations in the particle correlations at larger q. The successful comparison between the predictions and the measurements for the blends further suggests that S(q) can be used to assess the uniformity of grafting density in polymer-grafted nanoparticle materials.

Nanoscale structure, dynamics and power conversion efficiency correlations in small molecule and oligomer-based photovoltaic devices

PubMed Central

Szarko, Jodi M.; Guo, Jianchang; Rolczynski, Brian S.; Chen, Lin X.

2011-01-01

Photovoltaic functions in organic materials are intimately connected to interfacial morphologies of molecular packing in films on the nanometer scale and molecular levels. This review will focus on current studies on correlations of nanoscale morphologies in organic photovoltaic (OPV) materials with fundamental processes relevant to photovoltaic functions, such as light harvesting, exciton splitting, exciton diffusion, and charge separation (CS) and diffusion. Small molecule photovoltaic materials will be discussed here. The donor and acceptor materials in small molecule OPV devices can be fabricated in vacuum-deposited, multilayer, crystalline thin films, or spin-coated together to form blended bulk heterojunction (BHJ) films. These two methods result in very different morphologies of the solar cell active layers. There is still a formidable debate regarding which morphology is favored for OPV optimization. The morphology of the conducting films has been systematically altered; using variations of the techniques above, the whole spectrum of film qualities can be fabricated. It is possible to form a highly crystalline material, one which is completely amorphous, or an intermediate morphology. In this review, we will summarize the past key findings that have driven organic solar cell research and the current state-of-the-art of small molecule and conducting oligomer materials. We will also discuss the merits and drawbacks of these devices. Finally, we will highlight some works that directly compare the spectra and morphology of systematically elongated oligothiophene derivatives and compare these oligomers to their polymer counterparts. We hope this review will shed some new light on the morphology differences of these two systems. PMID:22110870

Regulation of Plasmodium yoelii oocyst development by strain- and stage-specific small-subunit rRNA.

PubMed

Qi, Yanwei; Zhu, Feng; Eastman, Richard T; Fu, Young; Zilversmit, Martine; Pattaradilokrat, Sittiporn; Hong, Lingxian; Liu, Shengfa; McCutchan, Thomas F; Pan, Weiqing; Xu, Wenyue; Li, Jian; Huang, Fusheng; Su, Xin-zhuan

2015-03-10

One unique feature of malaria parasites is the differential transcription of structurally distinct rRNA (rRNA) genes at different developmental stages: the A-type genes are transcribed mainly in asexual stages, whereas the S-type genes are expressed mostly in sexual or mosquito stages. Conclusive functional evidence of different rRNAs in regulating stage-specific parasite development, however, is still absent. Here we performed genetic crosses of Plasmodium yoelii parasites with one parent having an oocyst development defect (ODD) phenotype and another producing normal oocysts to identify the gene(s) contributing to the ODD. The parent with ODD--characterized as having small oocysts and lacking infective sporozoites--was obtained after introduction of a plasmid with a green fluorescent protein gene into the parasite genome and subsequent passages in mice. Quantitative trait locus analysis of genome-wide microsatellite genotypes of 48 progeny from the crosses linked an ~200-kb segment on chromosome 6 containing one of the S-type genes (D-type small subunit rRNA gene [D-ssu]) to the ODD. Fine mapping of the plasmid integration site, gene expression pattern, and gene knockout experiments demonstrated that disruption of the D-ssu gene caused the ODD phenotype. Interestingly, introduction of the D-ssu gene into the same parasite strain (self), but not into a different subspecies, significantly affected or completely ablated oocyst development, suggesting a stage- and subspecies (strain)-specific regulation of oocyst development by D-ssu. This study demonstrates that P. yoelii D-ssu is essential for normal oocyst and sporozoite development and that variation in the D-ssu sequence can have dramatic effects on parasite development. Malaria parasites are the only known organisms that express structurally distinct rRNA genes at different developmental stages. The differential expression of these genes suggests that they play unique roles during the complex life cycle of the parasites. Conclusive functional proof of different rRNAs in regulating parasite development, however, is still absent or controversial. Here we functionally demonstrate for the first time that a stage-specifically expressed D-type small-subunit rRNA gene (D-ssu) is essential for oocyst development of the malaria parasite Plasmodium yoelii in the mosquito. This study also shows that variations in D-ssu sequence and/or the timing of transcription may have profound effects on parasite oocyst development. The results show that in addition to protein translation, rRNAs of malaria parasites also regulate parasite development and differentiation in a strain-specific manner, which can be explored for controlling parasite transmission. Copyright © 2015 Qi et al.

An assessment of non-volant terrestrial vertebrates response to wind farms--a study of small mammals.

PubMed

Łopucki, Rafał; Mróz, Iwona

2016-02-01

The majority of studies on the effects of wind energy development on wildlife have been focused on birds and bats, whereas knowledge of the response of terrestrial, non-flying vertebrates is very scarce. In this paper, the impact of three functioning wind farms on terrestrial small mammal communities (rodents and shrews) and the population parameters of the most abundant species were studied. The study was carried out in southeastern Poland within the foothills of the Outer Western Carpathians. Small mammals were captured at 12 sites around wind turbines and at 12 control sites. In total, from 1200 trap-days, 885 individuals of 14 studied mammal species were captured. There was no difference in the characteristics of communities of small mammals near wind turbines and within control sites; i.e. these types of sites were inhabited by a similar number of species of similar abundance, similar species composition, species diversity (H' index) and species evenness (J') (Pielou's index). For the two species with the highest proportion in the communities (Apodemus agrarius and Microtus arvalis), the parameters of their populations (mean body mass, sex ratio, the proportion of adult individuals and the proportion of reproductive female) were analysed. In both species, none of the analysed parameters differed significantly between sites in the vicinity of turbines and control sites. For future studies on the impact of wind turbines on small terrestrial mammals in different geographical areas and different species communities, we recommend the method of paired 'turbine-control sites' as appropriate for animal species with pronounced fluctuations in population numbers.

A comparison of small-field tissue phantom ratio data generation methods for an Elekta Agility 6 MV photon beam

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

Richmond, Neil, E-mail: neil.richmond@stees.nhs.uk; Brackenridge, Robert

2014-04-01

Tissue-phantom ratios (TPRs) are a common dosimetric quantity used to describe the change in dose with depth in tissue. These can be challenging and time consuming to measure. The conversion of percentage depth dose (PDD) data using standard formulae is widely employed as an alternative method in generating TPR. However, the applicability of these formulae for small fields has been questioned in the literature. Functional representation has also been proposed for small-field TPR production. This article compares measured TPR data for small 6 MV photon fields against that generated by conversion of PDD using standard formulae to assess the efficacymore » of the conversion data. By functionally fitting the measured TPR data for square fields greater than 4 cm in length, the TPR curves for smaller fields are generated and compared with measurements. TPRs and PDDs were measured in a water tank for a range of square field sizes. The PDDs were converted to TPRs using standard formulae. TPRs for fields of 4 × 4 cm{sup 2} and larger were used to create functional fits. The parameterization coefficients were used to construct extrapolated TPR curves for 1 × 1 cm{sup 2}, 2 × 2-cm{sup 2}, and 3 × 3-cm{sup 2} fields. The TPR data generated using standard formulae were in excellent agreement with direct TPR measurements. The TPR data for 1 × 1-cm{sup 2}, 2 × 2-cm{sup 2}, and 3 × 3-cm{sup 2} fields created by extrapolation of the larger field functional fits gave inaccurate initial results. The corresponding mean differences for the 3 fields were 4.0%, 2.0%, and 0.9%. Generation of TPR data using a standard PDD-conversion methodology has been shown to give good agreement with our directly measured data for small fields. However, extrapolation of TPR data using the functional fit to fields of 4 × 4 cm{sup 2} or larger resulted in generation of TPR curves that did not compare well with the measured data.« less

Small wash functions and effects of their disturbance on vegetation of a Mojave Desert bajada

NASA Astrophysics Data System (ADS)

Sandquist, D. R.; Bedford, D.; Macias, M.; Miller, D. M.; Newlander, A.; Schwinning, S.

2011-12-01

The extensive network of small washes and channels that pervades most desert bajadas usually represents only a small proportion of the bajada's spatial area and are usually devoid of vegetation. However, these channels may be the most important geomorphic feature influencing vegetation properties and processes in arid lands. To evaluate the functional influence of small channels on the vegetation of a Mojave Desert bajada, we conducted a series of observations and experiments across a ~100 year old linear disturbance (railroad and parallel road) that disrupts the natural flow path of the channel network. In areas below the railroad where flow has been either increased due to channel diversion and coalescence through culverts, or cut off due to diversion, plant community structure and cover has changed relative to undisturbed areas. Plant physiological responses to simulated runoff experiments, conducted in active (undisturbed) and inactive (cut-off) channels, revealed subtle differences that, when compounded through time, are likely to contribute to these shifts in vegetation. Measurements of water potential on the two dominant plant species, Larrea tridentata and Ambrosia dumosa, indicate that Larrea within 3 m of a channel, and Ambrosia within 2 m, access water from the channel. However, the water potential responses were less pronounced, shorter in duration and more variable for plants adjacent to inactive channels than for those near active channels. Stomatal conductance and sap-flow measurements on Larrea corroborated these findings, suggesting that root patterns and functions associated with channels are altered when water flow is reduced or eliminated over extended periods of time. These findings indicate that disturbance of small desert washes and channels can lead to vegetation shifts through time with consequences that are not yet fully understood. Small desert washes and channels may represent a minor spatial component of the vast bajada landscape, but runoff and higher infiltration rates, coupled with the breadth of their spatial influence on adjacent plants, suggests that these modest geomorphic features may have a disproportionate impact on plant function and community properties in arid ecosystems.

Transforming SIBTEST to Account for Multilevel Data Structures

ERIC Educational Resources Information Center

French, Brian F.; Finch, W. Holmes

2015-01-01

SIBTEST is a differential item functioning (DIF) detection method that is accurate and effective with small samples, in the presence of group mean differences, and for assessment of both uniform and nonuniform DIF. The presence of multilevel data with DIF detection has received increased attention. Ignoring such structure can inflate Type I error.…

Compare Human-Made Objects with Natural Objects. Grades 3-5.

ERIC Educational Resources Information Center

Rushton, Erik; Ryan, Emily; Swift, Charles

In this activity, students experiment and observe the similarities and differences between human-made objects and nature in small groups. Students compare the function and structure of hollow bones with drinking straws, bird beaks and tool pliers, and bat wings and airplane wings. A classroom discussion can be held to discuss similarities and…

Riparian buffer and density management influences on microclimate of young headwater forests of Western Oregon.

Treesearch

Paul D. Anderson; David J. Larson; Samuel S. Chan

2007-01-01

Thinning of 30- to 70-year-old Douglas-fir (Psuedotsuga menziesii [Mirb.] Franco) stands is a common silvicultural activity on federal forest lands of the Pacific Northwest, United States. Empirical relationships among riparian functions, silvicultural treatments, and different riparian buffer widths are not well documented for small headwater...

Engineered Saccharomyces cerevisiae strain for improved xylose utilization with a three-plasmid SUMO yeast expression system

USDA-ARS?s Scientific Manuscript database

A three-plasmid yeast expression system utilizing the portable small ubiquitin-like modifier (SUMO) vector set combined with the efficient endogenous yeast protease Ulp1 was developed for production of large amounts of soluble functional protein in Saccharomyces cerevisiae. Each vector has a differ...

Energy metabolism of synaptosomes from different neuronal systems of rat cerebellum during aging: a functional proteomic characterization.

PubMed

Ferrari, Federica; Gorini, Antonella; Villa, Roberto Federico

2015-01-01

Functional proteomics was used to characterize age-related changes in energy metabolism of different neuronal pathways within the cerebellar cortex of Wistar rats aged 2, 6, 12, 18, and 24 months. The "large" synaptosomes, derived from the glutamatergic mossy fibre endings which make synaptic contact with the granule cells of the granular layer, and the "small" synaptosomes, derived from the pre-synaptic terminals of granule cells making synaptic contact with the dendrites of Purkinje cells, were isolated by a combined differential/gradient centrifugation technique. Because most brain disorders are associated with bioenergetic changes, the maximum rate (Vmax) of selected enzymes of glycolysis, Krebs' cycle, glutamate and amino acids metabolism, and acetylcholine catabolism were evaluated. The results show that "large" and "small" synaptosomes possess specific and independent metabolic features. This study represents a reliable model to study in vivo (1) the physiopathological molecular mechanisms of some brain diseases dependent on energy metabolism, (2) the responsiveness to noxious stimuli, and (3) the effects of drugs, discriminating their action sites at subcellular level on specific neuronal pathways.

Error Patterns with Fraction Calculations at Fourth Grade as a Function of Students' Mathematics Achievement Status.

PubMed

Schumacher, Robin F; Malone, Amelia S

2017-09-01

The goal of the present study was to describe fraction-calculation errors among 4 th -grade students and determine whether error patterns differed as a function of problem type (addition vs. subtraction; like vs. unlike denominators), orientation (horizontal vs. vertical), or mathematics-achievement status (low- vs. average- vs. high-achieving). We specifically addressed whether mathematics-achievement status was related to students' tendency to operate with whole number bias. We extended this focus by comparing low-performing students' errors in two instructional settings that focused on two different types of fraction understandings: core instruction that focused on part-whole understanding vs. small-group tutoring that focused on magnitude understanding. Results showed students across the sample were more likely to operate with whole number bias on problems with unlike denominators. Students with low or average achievement (who only participated in core instruction) were more likely to operate with whole number bias than students with low achievement who participated in small-group tutoring. We suggest instruction should emphasize magnitude understanding to sufficiently increase fraction understanding for all students in the upper elementary grades.

[Analysis of tissue-specific differentially methylated genes with differential gene expression in non-small cell lung cancer].

PubMed

Yin, L G; Zou, Z Q; Zhao, H Y; Zhang, C L; Shen, J G; Qi, L; Qi, M; Xue, Z Q

2014-01-01

Adenocarcinoma (ADC) and squamous cell carcinomas (SCC) are two subtypes of non-small cell lung carcinomas which are regarded as the leading cause of cancer-related malignancy worldwide. The aim of this study is to detect the differentially methylated loci (DMLs) and differentially methylated genes (DMGs) of these two tumor sets, and then to illustrate the different expression level of specific methylated genes. Using TCGA database and Illumina HumanMethylation 27 arrays, we first screened the DMGs and DMLs in tumor samples. Then, we explored the BiologicalProcess terms of hypermethylated and hypomethylated genes using Functional Gene Ontology (GO) catalogues. Hypermethylation intensively occurred in CpG-island, whereas hypomethylation was located in non-CpG-island. Most SCC and ADC hypermethylated genes involved GO function of DNA dependenit regulation of transcription, and hypomethylated genes mainly 'enriched in the term of immune responses. Additionally, the expression level of specific differentially methylated genesis distinctbetween ADC and SCC. It is concluded that ADC and SCC have different methylated status that might play an important role in carcinogenesis.

Nature and function of insulator protein binding sites in the Drosophila genome

PubMed Central

Schwartz, Yuri B.; Linder-Basso, Daniela; Kharchenko, Peter V.; Tolstorukov, Michael Y.; Kim, Maria; Li, Hua-Bing; Gorchakov, Andrey A.; Minoda, Aki; Shanower, Gregory; Alekseyenko, Artyom A.; Riddle, Nicole C.; Jung, Youngsook L.; Gu, Tingting; Plachetka, Annette; Elgin, Sarah C.R.; Kuroda, Mitzi I.; Park, Peter J.; Savitsky, Mikhail; Karpen, Gary H.; Pirrotta, Vincenzo

2012-01-01

Chromatin insulator elements and associated proteins have been proposed to partition eukaryotic genomes into sets of independently regulated domains. Here we test this hypothesis by quantitative genome-wide analysis of insulator protein binding to Drosophila chromatin. We find distinct combinatorial binding of insulator proteins to different classes of sites and uncover a novel type of insulator element that binds CP190 but not any other known insulator proteins. Functional characterization of different classes of binding sites indicates that only a small fraction act as robust insulators in standard enhancer-blocking assays. We show that insulators restrict the spreading of the H3K27me3 mark but only at a small number of Polycomb target regions and only to prevent repressive histone methylation within adjacent genes that are already transcriptionally inactive. RNAi knockdown of insulator proteins in cultured cells does not lead to major alterations in genome expression. Taken together, these observations argue against the concept of a genome partitioned by specialized boundary elements and suggest that insulators are reserved for specific regulation of selected genes. PMID:22767387

The effect of low glucose degradation product, neutral pH versus standard peritoneal dialysis solutions on peritoneal membrane function: the balANZ trial

PubMed Central

Johnson, David W.; Brown, Fiona G.; Clarke, Margaret; Boudville, Neil; Elias, Tony J.; Foo, Marjorie W.Y.; Jones, Bernard; Kulkarni, Hemant; Langham, Robyn; Ranganathan, Dwarakanathan; Schollum, John; Suranyi, Michael G.; Tan, Seng H.; Voss, David

2012-01-01

Background The balANZ trial recently reported that neutral pH, low glucose degradation product (biocompatible) peritoneal dialysis (PD) solutions significantly delayed anuria and reduced peritonitis rates compared with conventional solutions. This article reports a secondary outcome analysis of the balANZ trial with respect to peritoneal membrane function. Methods Adult, incident PD patients with residual renal function were randomized to receive either biocompatible or conventional (control) PD solutions for 2 years. Peritoneal equilibration tests were performed at 1, 6, 12, 18 and 24 months. Peritoneal small solute clearances and ultra-filtration (UF) were measured at 3, 6, 9, 12, 18 and 24 months. Results Of the 185 patients recruited into the trial, 85 patients in the Balance group and 82 patients in the control group had peritoneal membrane function evaluated. Mean 4-h dialysate:plasma creatinine ratios (D:P Cr 4h) at 1 month were significantly higher in the Balance group compared with controls (0.67 ± 0.10 versus 0.62 ± 0.10, P = 0.002). Over the 2-year study period, mean D:P Cr 4 h measurements remained stable in the Balance group but increased significantly in controls [difference −0.004 per month, 95% confidence interval (95% CI) −0.005 to −0.002, P < 0.001]. Similar results were obtained for dialysate glucose ratios (D/D0 glucose). Peritoneal UF was significantly lower in the Balance group than in controls at 3 and 6 months. Over the 2-year study period, peritoneal UF increased significantly in the Balance group but remained stable in controls (difference 24 mL/day/month, 95% CI 9–39, P = 0.002). No differences in peritoneal small solute clearances, prescribed dialysate fill volumes or peritoneal glucose exposure were observed between the two groups. Conclusions Biocompatible and conventional PD solutions exert differential effects on peritoneal small solute transport rate and UF over time. Adequately powered trials assessing the impact of these differential membrane effects on PD technique and patient survival rates are warranted. PMID:22859794

Multidimensional model of apathy in older adults using partial least squares--path modeling.

PubMed

Raffard, Stéphane; Bortolon, Catherine; Burca, Marianna; Gely-Nargeot, Marie-Christine; Capdevielle, Delphine

2016-06-01

Apathy defined as a mental state characterized by a lack of goal-directed behavior is prevalent and associated with poor functioning in older adults. The main objective of this study was to identify factors contributing to the distinct dimensions of apathy (cognitive, emotional, and behavioral) in older adults without dementia. One hundred and fifty participants (mean age, 80.42) completed self-rated questionnaires assessing apathy, emotional distress, anticipatory pleasure, motivational systems, physical functioning, quality of life, and cognitive functioning. Data were analyzed using partial least squares variance-based structural equation modeling in order to examine factors contributing to the three different dimensions of apathy in our sample. Overall, the different facets of apathy were associated with cognitive functioning, anticipatory pleasure, sensitivity to reward, and physical functioning, but the contribution of these different factors to the three dimensions of apathy differed significantly. More specifically, the impact of anticipatory pleasure and physical functioning was stronger for the cognitive than for emotional apathy. Conversely, the impact of sensibility to reward, although small, was slightly stronger on emotional apathy. Regarding behavioral apathy, again we found similar latent variables except for the cognitive functioning whose impact was not statistically significant. Our results highlight the need to take into account various mechanisms involved in the different facets of apathy in older adults without dementia, including not only cognitive factors but also motivational variables and aspects related to physical disability. Clinical implications are discussed.

Functional segmentation of dynamic PET studies: Open source implementation and validation of a leader-follower-based algorithm.

PubMed

Mateos-Pérez, José María; Soto-Montenegro, María Luisa; Peña-Zalbidea, Santiago; Desco, Manuel; Vaquero, Juan José

2016-02-01

We present a novel segmentation algorithm for dynamic PET studies that groups pixels according to the similarity of their time-activity curves. Sixteen mice bearing a human tumor cell line xenograft (CH-157MN) were imaged with three different (68)Ga-DOTA-peptides (DOTANOC, DOTATATE, DOTATOC) using a small animal PET-CT scanner. Regional activities (input function and tumor) were obtained after manual delineation of regions of interest over the image. The algorithm was implemented under the jClustering framework and used to extract the same regional activities as in the manual approach. The volume of distribution in the tumor was computed using the Logan linear method. A Kruskal-Wallis test was used to investigate significant differences between the manually and automatically obtained volumes of distribution. The algorithm successfully segmented all the studies. No significant differences were found for the same tracer across different segmentation methods. Manual delineation revealed significant differences between DOTANOC and the other two tracers (DOTANOC - DOTATATE, p=0.020; DOTANOC - DOTATOC, p=0.033). Similar differences were found using the leader-follower algorithm. An open implementation of a novel segmentation method for dynamic PET studies is presented and validated in rodent studies. It successfully replicated the manual results obtained in small-animal studies, thus making it a reliable substitute for this task and, potentially, for other dynamic segmentation procedures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cats are not small dogs: is there an immunological explanation for why cats are less affected by arthropod-borne disease than dogs?

PubMed

Day, Michael J

2016-09-20

It is widely recognized that cats appear to be less frequently affected by arthropod-borne infectious diseases than dogs and share fewer zoonotic pathogens with man. This impression is supported by the relative lack of scientific publications related to feline vector-borne infections. This review explores the possible reasons for the difference between the two most common small companion animal species, including the hypothesis that cats might have a genetically-determined immunological resistance to arthropod vectors or the microparasites they transmit. A number of simple possibilities might account for the lower prevalence of these diseases in cats, including factors related to the lifestyle and behaviour of the cat, lesser spend on preventative healthcare for cats and reduced opportunities for research funding for these animals. The dog and cat have substantially similar immune system components, but differences in immune function might in part account for the markedly distinct prevalence and clinicopathological appearance of autoimmune, allergic, idiopathic inflammatory, immunodeficiency, neoplastic and infectious diseases in the two species. Cats have greater genetic diversity than dogs with much lower linkage disequilibrium in feline compared with canine breed groups. Immune function is intrinsically related to the nature of the intestinal microbiome and subtle differences between the canine and feline microbial populations might also impact on immune function and disease resistance. The reasons for the apparent lesser susceptibility of cats to arthropod-borne infectious diseases are likely to be complex, but warrant further investigation.

Linear rheology and structure of molecular bottlebrushes with short side chains

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

López-Barrón, Carlos R., E-mail: carlos.r.lopez-barron@exxonmobil.com; Brant, Patrick; Crowther, Donna J.

We investigate the microstructure and linear viscoelasticity of model molecular bottlebrushes (BBs) using rheological and small-angle X-ray and neutron scattering measurements. Our polymers have short atactic polypropylene (aPP) side chains of molecular weight ranging from 119 g/mol to 259 g/mol and narrow molecular weight distribution (M{sub w}/M{sub n} 1.02–1.05). The side chain molecular weights are a small fraction of the entanglement molecular weight of the corresponding linear polymer (M{sub e,aPP}= 7.05 kg/mol), and as such, they are unentangled. The morphology of the aPP BBs is characterized as semiflexible thick chains with small side chain interdigitation. Their dynamic master curves, obtained by time-temperature superposition,more » reveal two sequential relaxation processes corresponding to the segmental relaxation and the relaxation of the BB backbone. Due to the short length of the side chains, their fast relaxation could not be distinguished from the glassy relaxation. The fractional free volume is an increasing function of the side chain length (N{sub SC}). Therefore, the glassy behavior of these polymers as well as their molecular friction and dynamic properties are influenced by their N{sub SC} values. The apparent flow activation energies are a decreasing function of N{sub SC}, and their values explain the differences in zero-shear viscosity measured at different temperatures.« less

Ecological structure and function differs between habitats dominated by seagrasses and green seaweeds.

PubMed

Tuya, Fernando; Png-Gonzalez, Lydia; Riera, Rodrigo; Haroun, Ricardo; Espino, Fernando

2014-07-01

Marine vegetated habitats, e.g. seagrass meadows, deliver essential functions and services to coastal ecosystems and human welfare. Impacts induced by humans, however, have facilitated the replacement of seagrasses by alternative vegetation, e.g. green rhizophytic seaweeds. The implications of habitat shifts for ecosystem attributes and processes and the services they deliver remain poorly known. In this study, we compared ecosystem structure and function between Cymodocea nodosa seagrass meadows and bottoms dominated by Caulerpa prolifera, a green, native, rhizophytic seaweed, through 5 ecological proxies: (i) primary production (via community metabolism), (ii) composition and abundance of epifauna (a proxy for provision of habitat for epifauna), composition and abundance of (iii) small-sized (juvenile) and (iv) large-sized (adult) fishes (proxies for provision of habitat for fishes), and (v) sediment retention (a proxy for sediment stabilization). Four of these proxies were greater in C. nodosa seagrass meadows than in C. prolifera beds: gross primary productivity (∼1.4 times), the total abundance, species density and biomass of small-sized fishes (∼2.1, 1.3 and 1.3 times, respectively), the total abundance and species density of large-sized fishes (∼3.6 and 1.5 times, respectively), and sediment stabilization (∼1.4 times). In contrast, the total abundance and species density of epifauna was larger (∼3.1 and 1.7 times, respectively) in C. prolifera than in C. nodosa seagrass beds. These results suggest that ecosystem structure and function may differ if seagrasses are replaced by green rhizophytic seaweeds. Importantly, ecosystem functions may not be appropriate surrogates for one another. As a result, assessments of ecosystem services associated with ecosystem functions cannot be based on exclusively one service that is expected to benefit other services. Copyright © 2014 Elsevier Ltd. All rights reserved.

Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

PubMed

Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

2012-10-01

A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

Elemental composition of particulate matter and the association with lung function.

PubMed

Eeftens, Marloes; Hoek, Gerard; Gruzieva, Olena; Mölter, Anna; Agius, Raymond; Beelen, Rob; Brunekreef, Bert; Custovic, Adnan; Cyrys, Josef; Fuertes, Elaine; Heinrich, Joachim; Hoffmann, Barbara; de Hoogh, Kees; Jedynska, Aleksandra; Keuken, Menno; Klümper, Claudia; Kooter, Ingeborg; Krämer, Ursula; Korek, Michal; Koppelman, Gerard H; Kuhlbusch, Thomas A J; Simpson, Angela; Smit, Henriëtte A; Tsai, Ming-Yi; Wang, Meng; Wolf, Kathrin; Pershagen, Göran; Gehring, Ulrike

2014-09-01

Negative effects of long-term exposure to particulate matter (PM) on lung function have been shown repeatedly. Spatial differences in the composition and toxicity of PM may explain differences in observed effect sizes between studies. We conducted a multicenter study in 5 European birth cohorts-BAMSE (Sweden), GINIplus and LISAplus (Germany), MAAS (United Kingdom), and PIAMA (The Netherlands)-for which lung function measurements were available for study subjects at the age of 6 or 8 years. Individual annual average residential exposure to copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc within PM smaller than 2.5 μm (PM2.5) and smaller than 10 μm (PM10) was estimated using land-use regression models. Associations between air pollution and lung function were analyzed by linear regression within cohorts, adjusting for potential confounders, and then combined by random effects meta-analysis. We observed small reductions in forced expiratory volume in the first second, forced vital capacity, and peak expiratory flow related to exposure to most elemental pollutants, with the most substantial negative associations found for nickel and sulfur. PM10 nickel and PM10 sulfur were associated with decreases in forced expiratory volume in the first second of 1.6% (95% confidence interval = 0.4% to 2.7%) and 2.3% (-0.1% to 4.6%) per increase in exposure of 2 and 200 ng/m, respectively. Associations remained after adjusting for PM mass. However, associations with these elements were not evident in all cohorts, and heterogeneity of associations with exposure to various components was larger than for exposure to PM mass. Although we detected small adverse effects on lung function associated with annual average levels of some of the evaluated elements (particularly nickel and sulfur), lower lung function was more consistently associated with increased PM mass.

Anisotropic polaron localization and spontaneous symmetry breaking: Comparison of cation-site acceptors in GaN and ZnO

NASA Astrophysics Data System (ADS)

Sun, Y. Y.; Abtew, Tesfaye A.; Zhang, Peihong; Zhang, S. B.

2014-10-01

The behavior of cation substitutional hole doping in GaN and ZnO is investigated using hybrid density functional calculations. Our results reveal that Mg substitution for Ga (MgGa) in GaN can assume three different configurations. Two of the configurations are characterized by the formation of defect-bound small polaron (i.e., a large structural distortion accompanied by hole localization on one of the neighboring N atoms). The third one has a relatively small but significant distortion that is characterized by highly anisotropic polaron localization. In this third configuration, MgGa exhibits both effective-mass-like and noneffective-mass-like characters. In contrast, a similar defect in ZnO, LiZn, cannot sustain the anisotropic polaron in the hybrid functional calculation, but undergoes spontaneous breaking of a mirror symmetry through a mechanism driven by the hole localization. Finally, using NaZn in ZnO as an example, we show that the deep acceptor levels of the small-polaron defects could be made shallower by applying compressive strain to the material.

SU-E-T-217: Intrinsic Respiratory Gating in Small Animal CT

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

Liu, Y; Smith, M; Mistry, N

Purpose: Preclinical animal models of lung cancer can provide a controlled test-bed for testing dose escalation or function-based-treatment-planning studies. However, to extract lung function, i.e. ventilation, one needs to be able to image the lung at different phases of ventilation (in-hale / ex-hale). Most respiratory-gated imaging using micro-CT involves using an external ventilator and surgical intervention limiting the utility in longitudinal studies. A new intrinsic respiratory retrospective gating method was developed and tested in mice. Methods: A fixed region of interest (ROI) that covers the diaphragm was selected on all projection images to estimate the mean intensity (M). The meanmore » intensity depends on the projection angle and diaphragm position. A 3-point moving average (A) of consecutive M values: Mpre, Mcurrent and Mpost, was calculated to be subtracted from Mcurrent. A fixed threshold was used to enable amplitude based sorting into 4 different phases of respiration. Images at full-inhale and end-exhale phases of respiration were reconstructed using the open source OSCaR. Lung volumes estimated at the 2 phases of respiration were validated against literature values. Results: Intrinsic retrospective gating was accomplished without the use of any external breathing waveform. While projection images were acquired at 360 different angles. Only 138 and 104 projections were used to reconstruct images at full-inhale and end-exhale. This often results in non-uniform under-sampled angular projections leading to some minor streaking artifacts. The calculated expiratory, inspiratory and tidal lung volumes correlated well with the values known from the literature. Conclusion: Our initial result demonstrates an intrinsic gating method that is suitable for flat panel cone beam small animal CT systems. Reduction in streaking artifacts can be accomplished by oversampling the data or using iterative reconstruction methods. This initial experience will enable freebreathing small animal micro-CT imaging to fuel longitudinal studies of lung function.« less

The Effect of Different Repeated-High-Intensity-Effort Bouts on Subsequent Running, Skill Performance, and Neuromuscular Function.

PubMed

Johnston, Rich D; Gabbett, Tim J; Jenkins, David G; Speranza, Michael J

2016-04-01

To assess the impact of different repeated-high-intensity-effort (RHIE) bouts on player activity profiles, skill involvements, and neuromuscular fatigue during small-sided games. 22 semiprofessional rugby league players (age 24.0 ± 1.8 y, body mass 95.6 ± 7.4 kg). During 4 testing sessions, they performed RHIE bouts that each differed in the combination of contact and running efforts, followed by a 5-min off-side small-sided game before performing a second bout of RHIE activity and another 5-min small-sided game. Global positioning system microtechnology and video recordings provided information on activity profiles and skill involvements. A countermovement jump and a plyometric push-up assessed changes in lower- and upper-body neuromuscular function after each session. After running-dominant RHIE bouts, players maintained running intensities during both games. In the contact-dominant RHIE bouts, reductions in moderate-speed activity were observed from game 1 to game 2 (ES = -0.71 to -1.06). There was also moderately lower disposal efficiency across both games after contact-dominant RHIE activity compared with running-dominant activity (ES = 0.62-1.02). Greater reductions in lower-body fatigue occurred as RHIE bouts became more running dominant (ES = -0.01 to -1.36), whereas upper-body fatigue increased as RHIE bouts became more contact dominant (ES = -0.07 to -1.55). Physical contact causes reductions in running intensity and the quality of skill involvements during game-based activities. In addition, the neuromuscular fatigue experienced by players is specific to the activities performed.

First constraints on the stellar mass function of star-forming clumps at the peak of cosmic star formation

NASA Astrophysics Data System (ADS)

Dessauges-Zavadsky, Miroslava; Adamo, Angela

2018-06-01

Star-forming clumps dominate the rest-frame ultraviolet morphology of galaxies at the peak of cosmic star formation. If turbulence driven fragmentation is the mechanism responsible for their formation, we expect their stellar mass function to follow a power-law of slope close to -2. We test this hypothesis performing the first analysis of the stellar mass function of clumps hosted in galaxies at z ˜ 1 - 3.5. The sample is gathered from the literature with similar detection thresholds and stellar masses determined in a homogeneous way. To overcome the small number statistics per galaxy (each galaxy hosts up to a few tens of clumps only), we combine all high-redshift clumps. The resulting clump mass function follows a power-law of slope ˜-1.7 and flattens at masses below 2 × 107 M⊙. By means of randomly sampled clump populations, drawn out of a power-law mass function of slope -2, we test the effect of combining small clump populations, detection limits of the surveys, and blending on the mass function. Our numerical exercise reproduces all the features observed in the real clump mass function confirming that it is consistent with a power-law of slope ≃ -2. This result supports the high-redshift clump formation through fragmentation in a similar fashion as in local galaxies, but under different gas conditions.

Genetic diversity of small eukaryotes in lakes differing by their trophic status.

PubMed

Lefranc, Marie; Thénot, Aurélie; Lepère, Cécile; Debroas, Didier

2005-10-01

Small eukaryotes, cells with a diameter of less than 5 mum, are fundamental components of lacustrine planktonic systems. In this study, small-eukaryote diversity was determined by sequencing cloned 18S rRNA genes in three libraries from lakes of differing trophic status in the Massif Central, France: the oligotrophic Lake Godivelle, the oligomesotrophic Lake Pavin, and the eutrophic Lake Aydat. This analysis shows that the least diversified library was in the eutrophic lake (12 operational taxonomic units [OTUs]) and the most diversified was in the oligomesotrophic lake (26 OTUs). Certain groups were present in at least two ecosystems, while the others were specific to one lake on the sampling date. Cryptophyta, Chrysophyceae, and the strictly heterotrophic eukaryotes, Ciliophora and fungi, were identified in the three libraries. Among the small eukaryotes found only in two lakes, Choanoflagellida and environmental sequences (LKM11) were not detected in the eutrophic system whereas Cercozoa were confined to the oligomesotrophic and eutrophic lakes. Three OTUs, linked to the Perkinsozoa, were detected only in the Aydat library, where they represented 60% of the clones of the library. Chlorophyta and Haptophyta lineages were represented by a single clone and were present only in Godivelle and Pavin, respectively. Of the 127 clones studied, classical pigmented organisms (autotrophs and mixotrophs) represented only a low proportion regardless of the library's origin. This study shows that the small-eukaryote community composition may differ as a function of trophic status; certain lineages could be detected only in a single ecosystem.

Volume estimation of small phantoms and rat kidneys using three-dimensional ultrasonography and a position sensor.

PubMed

Strømmen, Kenneth; Stormark, Tor André; Iversen, Bjarne M; Matre, Knut

2004-09-01

To evaluate the accuracy of small volume estimation, both in vivo and in vitro, measurements with a three-dimensional (3D) ultrasound (US) system were carried out. A position sensor was used and the transmitting frequency was 10 MHz. Balloons with known volumes were scanned while rat kidneys were scanned in vivo and in vitro. The Archimedes' principle was used to estimate the true volume. For balloons, the 3D US system gave very good agreement with true volumes in the volume range 0.1 to 10.0 mL (r = 0.999, n = 45, mean difference +/- 2SD = 0.245 +/- 0.370 mL). For rat kidneys in vivo (volume range 0.6 to 2.7 mL) the method was less accurate (r = 0.800, n = 10, mean difference +/- 2SD = -0.288 +/- 0.676 mL). For rat kidneys in vitro (volume range 0.3 to 2.7 mL) the results showed good agreement (r = 0.981, n = 23, mean difference +/- 2SD = 0.039 +/- 0.254 mL). For balloons, kidneys in vivo and in vitro, the mean percentage error was 9.3 +/- 4.8%, -17.1 +/- 17.4%, and 4.6 +/- 11.5%, respectively. This method can estimate the volume of small phantoms and rat kidneys and opens new possibilities for volume measurements of small objects and the study of organ function in small animals. (E-mail ).

Model for fluorescence quenching in light harvesting complex II in different aggregation states.

PubMed

Andreeva, Atanaska; Abarova, Silvia; Stoitchkova, Katerina; Busheva, Mira

2009-02-01

Low-temperature (77 K) steady-state fluorescence emission spectroscopy and dynamic light scattering were applied to the main chlorophyll a/b protein light harvesting complex of photosystem II (LHC II) in different aggregation states to elucidate the mechanism of fluorescence quenching within LHC II oligomers. Evidences presented that LHC II oligomers are heterogeneous and consist of large and small particles with different fluorescence yield. At intermediate detergent concentrations the mean size of the small particles is similar to that of trimers, while the size of large particles is comparable to that of aggregated trimers without added detergent. It is suggested that in small particles and trimers the emitter is monomeric chlorophyll, whereas in large aggregates there is also another emitter, which is a poorly fluorescing chlorophyll associate. A model, describing populations of antenna chlorophyll molecules in small and large aggregates in their ground and first singlet excited states, is considered. The model enables us to obtain the ratio of the singlet excited-state lifetimes in small and large particles, the relative amount of chlorophyll molecules in large particles, and the amount of quenchers as a function of the degree of aggregation. These dependencies reveal that the quenching of the chl a fluorescence upon aggregation is due to the formation of large aggregates and the increasing of the amount of chlorophyll molecules forming these aggregates. As a consequence, the amount of quenchers, located in large aggregates, is increased, and their singlet excited-state lifetimes steeply decrease.

Brain atrophy and cerebral small vessel disease: a prospective follow-up study.

PubMed

Nitkunan, Arani; Lanfranconi, Silvia; Charlton, Rebecca A; Barrick, Thomas R; Markus, Hugh S

2011-01-01

cerebral small vessel disease (SVD) is the most common cause of vascular dementia. Interest in the use of surrogate markers is increasing. The aims of this study were to determine if brain volume was different between patients with SVD and control subjects, whether it correlated with cognition in SVD, and whether changes in brain volume could be detected during prospective follow-up. thirty-five patients (mean age, 68.8 years) who had a lacunar stroke and radiological evidence of confluent leukoaraiosis and 70 age- and gender-matched control subjects were recruited. Whole-brain T1-weighted imaging and neuropsychological testing were performed after 1 year on all patients and after 2 years for the control subjects. Fully automated software was used to determine brain volume and percentage brain volume change. An executive function score was derived. there was a significant difference in brain volume between the patients with SVD and control subjects (mean ± SD [mL] 1529 ± 84 versus 1573 ± 69, P=0.019). In the patients with SVD, there was a significant association between brain volume and executive function (r=0.501, P<0.05). The mean ± SD yearly brain atrophy rate for patients with SVD and control subjects was significantly different (-0.914% ± 0.8% versus -0.498% ± 0.4%, respectively, P=0.017). No change in executive function score was detected over this period. brain volume is reduced in SVD and a decline is detectable prospectively. The correlation with executive function at a cross-sectional level and the change in brain volume with time are both promising for the use of brain atrophy as a surrogate marker of SVD progression.

Survival Benefits of Small Anatomical Resection of the Liver for Patients with Hepatocellular Carcinoma and Impaired Liver Function, Based on New-Era Imaging Studies.

PubMed

Sakoda, Masahiko; Ueno, Shinichi; Iino, Satoshi; Hiwatashi, Kiyokazu; Minami, Koji; Kawasaki, Yota; Kurahara, Hiroshi; Mataki, Yuko; Maemura, Kosei; Shinchi, Hiroyuki; Natsugoe, Shoji

2016-01-01

It has been reported that anatomical resection of the liver may be preferred for primary hepatocellular carcinoma (HCC), and is at least recommended for systematic removal of a segment confined by tumor-bearing portal tributaries. However, nonanatomical resection (NAR) is often selected because of the patient's background, impairment of liver function, and tumor factors. The aims of the present study were to retrospectively compare the recurrence-free survival (RFS) rates for cases of partial resection (PR) and for small anatomical resection (SAR), which is regarded as NAR for primary HCC with impaired liver function. So-called NAR was performed for a primary and solitary (≤ 5cm) HCC in 47 patients; the patients were classified into PR (n=25) and SAR (n=22) groups. Clinicopathological factors, survival data, and recurrence patterns were compared between groups. There were no significant differences in the preoperative characteristics between the two groups. Operative time was significantly longer in the SAR group than in the PR group. There was no significant difference in the postoperative morbidity and tumor pathological characteristics between the two groups. The RFS of the SAR group was significantly better than those of the PR group. Although there was no significant difference in the pattern of recurrence between the two groups, the rate of intrahepatic recurrence in the same segment as the initial tumor tended to be higher in the PR group than in the SAR group. Multivariate analysis revealed that only the PR operative procedure was significant independent risk factor for poorer RFS. Compared with PR, SAR effectively improves the rate of RFS after surgery for a primary and solitary HCC with impaired liver function.

Mapping the Small Molecule Interactome by Mass Spectrometry.

PubMed

Flaxman, Hope A; Woo, Christina M

2018-01-16

Mapping small molecule interactions throughout the proteome provides the critical structural basis for functional analysis of their impact on biochemistry. However, translation of mass spectrometry-based proteomics methods to directly profile the interaction between a small molecule and the whole proteome is challenging because of the substoichiometric nature of many interactions, the diversity of covalent and noncovalent interactions involved, and the subsequent computational complexity associated with their spectral assignment. Recent advances in chemical proteomics have begun fill this gap to provide a structural basis for the breadth of small molecule-protein interactions in the whole proteome. Innovations enabling direct characterization of the small molecule interactome include faster, more sensitive instrumentation coupled to chemical conjugation, enrichment, and labeling methods that facilitate detection and assignment. These methods have started to measure molecular interaction hotspots due to inherent differences in local amino acid reactivity and binding affinity throughout the proteome. Measurement of the small molecule interactome is producing structural insights and methods for probing and engineering protein biochemistry. Direct structural characterization of the small molecule interactome is a rapidly emerging area pushing new frontiers in biochemistry at the interface of small molecules and the proteome.

Tapping in synchrony with a perturbed metronome: the phase correction response to small and large phase shifts as a function of tempo.

PubMed

Repp, Bruno H

2011-01-01

When tapping is paced by an auditory sequence containing small phase shift (PS) perturbations, the phase correction response (PCR) of the tap following a PS increases with the baseline interonset interval (IOI), leading eventually to overcorrection (B. H. Repp, 2008). Experiment 1 shows that this holds even for fixed-size PSs that become imperceptible as the IOI increases (here, from 400 to 1200 ms). Earlier research has also shown (but only for IOI=500 ms) that the PCR is proportionally smaller for large than for small PSs (B. H. Repp, 2002a, 2002b). Experiment 2 introduced large PSs and found smaller PCRs than in Experiment 1, at all of the same IOIs. In Experiments 3A and 3B, the author investigated whether the change in slope of the sigmoid function relating PCR and PS magnitudes occurs at a fixed absolute or relative PS magnitude across different IOIs (600, 1000, 1400 ms). The results suggest no clear answer; the exact shape of the function may depend on the range of PSs used in an experiment. Experiment 4 examined the PCR in the IOI range from 1000 to 2000 ms and found overcorrection throughout, but with the PCR increasing much more gradually than in Experiment 1. These results provide important new information about the phase correction process and pose challenges for models of sensorimotor synchronization, which presently cannot explain nonlinear PCR functions and overcorrection. Copyright © Taylor & Francis Group, LLC

Controlling the Morphology of BDTT-DPP-Based Small Molecules via End-Group Functionalization for Highly Efficient Single and Tandem Organic Photovoltaic Cells.

PubMed

Kim, Ji-Hoon; Park, Jong Baek; Yang, Hoichang; Jung, In Hwan; Yoon, Sung Cheol; Kim, Dongwook; Hwang, Do-Hoon

2015-11-04

A series of narrow-band gap, π-conjugated small molecules based on diketopyrrolopyrrole (DPP) electron acceptor units coupled with alkylthienyl-substituted-benzodithiophene (BDTT) electron donors were designed and synthesized for use as donor materials in solution-processed organic photovoltaic cells. In particular, by end-group functionalization of the small molecules with fluorine derivatives, the nanoscale morphologies of the photoactive layers of the photovoltaic cells were successfully controlled. The influences of different fluorine-based end-groups on the optoelectronic and morphological properties, carrier mobilities, and the photovoltaic performances of these materials were investigated. A high power conversion efficiency (PCE) of 6.00% under simulated solar light (AM 1.5G) illumination has been achieved for organic photovoltaic cells based on a small-molecule bulk heterojunction system consisting of a trifluoromethylbenzene (CF3) end-group-containing oligomer (BDTT-(DPP)2-CF3) as the donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor. As a result, the introduction of CF3 end-groups has been found to enhance both the short circuit current density (JSC) and fill factor (FF). A tandem photovoltaic device comprising an inverted BDTT-(DPP)2-CF3:PC71BM cell and a poly(3-hexylthiophene) (P3HT):indene-C60-bisadduct (IC60BA)-based cell as the top and bottom cell components, respectively, showed a maximum PCE of 8.30%. These results provide valuable guidelines for the rational design of conjugated small molecules for applications in high-performance organic photovoltaic cells. Furthermore, to the best of our knowledge, this is the first report on the design of fluorine-functionalized BDTT-DPP-based small molecules, which have been shown to be a viable candidate for use in inverted tandem cells.

Limiting cases of the small-angle scattering approximation solutions for the propagation of laser beams in anisotropic scattering media

NASA Technical Reports Server (NTRS)

Box, M. A.; Deepak, A.

1981-01-01

The propagation of photons in a medium with strongly anisotropic scattering is a problem with a considerable history. Like the propagation of electrons in metal foils, it may be solved in the small-angle scattering approximation by the use of Fourier-transform techniques. In certain limiting cases, one may even obtain analytic expressions. This paper presents some of these results in a model-independent form and also illustrates them by the use of four different phase-function models. Sample calculations are provided for comparison purposes

Dimensional crossover in fragmentation

NASA Astrophysics Data System (ADS)

Sotolongo-Costa, Oscar; Rodriguez, Arezky H.; Rodgers, G. J.

2000-11-01

Experiments in which thick clay plates and glass rods are fractured have revealed different behavior of fragment mass distribution function in the small and large fragment regions. In this paper we explain this behavior using non-extensive Tsallis statistics and show how the crossover between the two regions is caused by the change in the fragments’ dimensionality during the fracture process. We obtain a physical criterion for the position of this crossover and an expression for the change in the power-law exponent between the small and large fragment regions. These predictions are in good agreement with the experiments on thick clay plates.

Developing a New Wireless Sensor Network Platform and Its Application in Precision Agriculture

PubMed Central

Aquino-Santos, Raúl; González-Potes, Apolinar; Edwards-Block, Arthur; Virgen-Ortiz, Raúl Alejandro

2011-01-01

Wireless sensor networks are gaining greater attention from the research community and industrial professionals because these small pieces of “smart dust” offer great advantages due to their small size, low power consumption, easy integration and support for “green” applications. Green applications are considered a hot topic in intelligent environments, ubiquitous and pervasive computing. This work evaluates a new wireless sensor network platform and its application in precision agriculture, including its embedded operating system and its routing algorithm. To validate the technological platform and the embedded operating system, two different routing strategies were compared: hierarchical and flat. Both of these routing algorithms were tested in a small-scale network applied to a watermelon field. However, we strongly believe that this technological platform can be also applied to precision agriculture because it incorporates a modified version of LORA-CBF, a wireless location-based routing algorithm that uses cluster-based flooding. Cluster-based flooding addresses the scalability concerns of wireless sensor networks, while the modified LORA-CBF routing algorithm includes a metric to monitor residual battery energy. Furthermore, results show that the modified version of LORA-CBF functions well with both the flat and hierarchical algorithms, although it functions better with the flat algorithm in a small-scale agricultural network. PMID:22346622

Developing a new wireless sensor network platform and its application in precision agriculture.

PubMed

Aquino-Santos, Raúl; González-Potes, Apolinar; Edwards-Block, Arthur; Virgen-Ortiz, Raúl Alejandro

2011-01-01

Wireless sensor networks are gaining greater attention from the research community and industrial professionals because these small pieces of "smart dust" offer great advantages due to their small size, low power consumption, easy integration and support for "green" applications. Green applications are considered a hot topic in intelligent environments, ubiquitous and pervasive computing. This work evaluates a new wireless sensor network platform and its application in precision agriculture, including its embedded operating system and its routing algorithm. To validate the technological platform and the embedded operating system, two different routing strategies were compared: hierarchical and flat. Both of these routing algorithms were tested in a small-scale network applied to a watermelon field. However, we strongly believe that this technological platform can be also applied to precision agriculture because it incorporates a modified version of LORA-CBF, a wireless location-based routing algorithm that uses cluster-based flooding. Cluster-based flooding addresses the scalability concerns of wireless sensor networks, while the modified LORA-CBF routing algorithm includes a metric to monitor residual battery energy. Furthermore, results show that the modified version of LORA-CBF functions well with both the flat and hierarchical algorithms, although it functions better with the flat algorithm in a small-scale agricultural network.

Renal function and size at young adult age after intrauterine growth restriction and very premature birth.

PubMed

Keijzer-Veen, Mandy G; Kleinveld, Hilda A; Lequin, Maarten H; Dekker, Friedo W; Nauta, Jeroen; de Rijke, Yolanda B; van der Heijden, Bert J

2007-10-01

Premature birth and intrauterine growth restriction may increase the risk of developing renal disease at adult age. Renal function may already be impaired at young adult age. Cross-sectional study. Very premature individuals (gestational age < 32 weeks) recruited from Project on Premature and Small for Gestational Age Infants and full-term-born controls (37 to 42 weeks) recruited from a children's hospital in Rotterdam, The Netherlands. All individuals were 20 years of age at the time of study. Gestational age and birth weight: premature and small for gestational age (SGA; n = 23), premature and appropriate for gestational age (n = 29), and controls (n = 30). Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction before and after renal stimulation with low-dose dopamine infusion and oral amino-acid intake. Urine albumin and renal ultrasound. Height, weight, kidney length and volume, GFR, and ERPF were significantly lower in the SGA group than in controls. After adjustment for body surface area, GFR did not differ significantly among groups. Mean ERPF was 71 mL/min/1.73 m(2) (95% confidence interval [CI], 3 to 139) less, but filtration fraction was only 1.3% (95% CI, -0.3 to 3.0) greater, in the SGA group than controls. Renal stimulation significantly increased GFR and ERPF and decreased filtration fraction in all groups. After renal stimulation, ERPF was 130 mL/min/1.73 m(2) (95% CI, 21 to 238) greater in the SGA group than controls, but GFR and filtration fraction did not differ significantly among groups. Microalbuminuria was present in 2 patients (8.7%) in the SGA group, but none in the appropriate-for-gestational-age group or controls. Renal function correlated with renal size. Small sample size. Our findings do not fully support the hypothesis that preterm birth in combination with intrauterine growth restriction contributes to renal function alterations at young adult age. Larger studies are needed to evaluate this hypothesis.

Wave Propagation in Non-Stationary Statistical Mantle Models at the Global Scale

NASA Astrophysics Data System (ADS)

Meschede, M.; Romanowicz, B. A.

2014-12-01

We study the effect of statistically distributed heterogeneities that are smaller than the resolution of current tomographic models on seismic waves that propagate through the Earth's mantle at teleseismic distances. Current global tomographic models are missing small-scale structure as evidenced by the failure of even accurate numerical synthetics to explain enhanced coda in observed body and surface waveforms. One way to characterize small scale heterogeneity is to construct random models and confront observed coda waveforms with predictions from these models. Statistical studies of the coda typically rely on models with simplified isotropic and stationary correlation functions in Cartesian geometries. We show how to construct more complex random models for the mantle that can account for arbitrary non-stationary and anisotropic correlation functions as well as for complex geometries. Although this method is computationally heavy, model characteristics such as translational, cylindrical or spherical symmetries can be used to greatly reduce the complexity such that this method becomes practical. With this approach, we can create 3D models of the full spherical Earth that can be radially anisotropic, i.e. with different horizontal and radial correlation functions, and radially non-stationary, i.e. with radially varying model power and correlation functions. Both of these features are crucial for a statistical description of the mantle in which structure depends to first order on the spherical geometry of the Earth. We combine different random model realizations of S velocity with current global tomographic models that are robust at long wavelengths (e.g. Meschede and Romanowicz, 2014, GJI submitted), and compute the effects of these hybrid models on the wavefield with a spectral element code (SPECFEM3D_GLOBE). We finally analyze the resulting coda waves for our model selection and compare our computations with observations. Based on these observations, we make predictions about the strength of unresolved small-scale structure and extrinsic attenuation.

Mathematical and numerical challenges in living biological materials

NASA Astrophysics Data System (ADS)

Forest, M. Gregory; Vasquez, Paula A.

2013-10-01

The proclaimed Century of Biology is rapidly leading to the realization of how starkly different and more complex biological materials are than the materials that underpinned the industrial and technological revolution. These differences arise, in part, because biological matter exhibits both viscous and elastic behavior. Moreover, this behavior varies across the frequency, wavelength and amplitude spectrum of forcing. This broadclass of responsesin biological matter requires multiple frequency-dependent functions to specify material behavior, instead of a discrete set of parameters that relate to either viscosity or elasticity. This complexity prevails even if the biological matter is assumed to be spatially homogeneous, which is rarely true. However, very little progress has been made on the characterization of heterogeneity and how to build that information into constitutive laws and predictive models. In addition, most biological matter is non-stationary, which motivates the term "living". Biomaterials typically are in an active state in order to perform certain functions, and they often are modified or replenished on the basis of external stimuli. It has become popular in materials engineering to try to duplicate some of the functionality of biomaterials, e.g., a lot of effort has gone into the design of self-assembling, self-healing and shape shifting materials. These distinguishing features of biomaterials require significantly more degrees of freedom than traditional composites and many of the molecular species and their roles in functionality have yet to be determined. A typical biological material includes small molecule biochemical species that react and diffuse within larger species. These large molecular weightspecies provide the primary structural and biophysical properties of the material. The small molecule binding and unbinding kinetics serves to modulate material properties, and typical small molecule production and release are governed by external stimuli (e.g., stress). The bottom line is that the mathematical and numerical tools of 20th Century materials science are often insufficient for describing biological materials and for predicting their behavior both in vitro and in vivo.

Recent advances in developing small molecules targeting RNA.

PubMed

Guan, Lirui; Disney, Matthew D

2012-01-20

RNAs are underexploited targets for small molecule drugs or chemical probes of function. This may be due, in part, to a fundamental lack of understanding of the types of small molecules that bind RNA specifically and the types of RNA motifs that specifically bind small molecules. In this review, we describe recent advances in the development and design of small molecules that bind to RNA and modulate function that aim to fill this void.

A Novel Method of Extraction of Blend Component Structure from SANS Measurements of Homopolymer Bimodal Blends.

PubMed

Smerdova, Olga; Graham, Richard S; Gasser, Urs; Hutchings, Lian R; De Focatiis, Davide S A

2014-05-01

A new method is presented for the extraction of single-chain form factors and interchain interference functions from a range of small-angle neutron scattering (SANS) experiments on bimodal homopolymer blends. The method requires a minimum of three blends, made up of hydrogenated and deuterated components with matched degree of polymerization at two different chain lengths, but with carefully varying deuteration levels. The method is validated through an experimental study on polystyrene homopolymer bimodal blends with [Formula: see text]. By fitting Debye functions to the structure factors, it is shown that there is good agreement between the molar mass of the components obtained from SANS and from chromatography. The extraction method also enables, for the first time, interchain scattering functions to be produced for scattering between chains of different lengths. [Formula: see text].

Intraspecific Polymorphism, Interspecific Divergence, and the Origins of Function-Altering Mutations in Deer Mouse Hemoglobin

PubMed Central

Natarajan, Chandrasekhar; Hoffmann, Federico G.; Lanier, Hayley C.; Wolf, Cole J.; Cheviron, Zachary A.; Spangler, Matthew L.; Weber, Roy E.; Fago, Angela; Storz, Jay F.

2015-01-01

Major challenges for illuminating the genetic basis of phenotypic evolution are to identify causative mutations, to quantify their functional effects, to trace their origins as new or preexisting variants, and to assess the manner in which segregating variation is transduced into species differences. Here, we report an experimental analysis of genetic variation in hemoglobin (Hb) function within and among species of Peromyscus mice that are native to different elevations. A multilocus survey of sequence variation in the duplicated HBA and HBB genes in Peromyscus maniculatus revealed that function-altering amino acid variants are widely shared among geographically disparate populations from different elevations, and numerous amino acid polymorphisms are also shared with closely related species. Variation in Hb-O2 affinity within and among populations of P. maniculatus is attributable to numerous amino acid mutations that have individually small effects. One especially surprising feature of the Hb polymorphism in P. maniculatus is that an appreciable fraction of functional standing variation in the two transcriptionally active HBA paralogs is attributable to recurrent gene conversion from a tandemly linked HBA pseudogene. Moreover, transpecific polymorphism in the duplicated HBA genes is not solely attributable to incomplete lineage sorting or introgressive hybridization; instead, it is mainly attributable to recurrent interparalog gene conversion that has occurred independently in different species. Partly as a result of concerted evolution between tandemly duplicated globin genes, the same amino acid changes that contribute to variation in Hb function within P. maniculatus also contribute to divergence in Hb function among different species of Peromyscus. In the case of function-altering Hb mutations in Peromyscus, there is no qualitative or quantitative distinction between segregating variants within species and fixed differences between species. PMID:25556236

Unruh thermal hadronization and the cosmological constant

NASA Astrophysics Data System (ADS)

Frassino, Antonia M.; Bleicher, Marcus; Mann, Robert B.

2018-05-01

We use black holes with a negative cosmological constant to investigate aspects of the freeze-out temperature for hadron production in high energy heavy-ion collisions. The two black hole solutions present in the anti-de Sitter geometry have different mass and are compared to the data showing that the small black hole solution is in good agreement. This is a new feature in the literature since the small black hole in general relativity has different thermodynamic behavior from that of the large black hole solution. We find that the inclusion of the cosmological constant (which can be interpreted as the plasma pressure) leads to a lowering of the temperature of the freeze-out curve as a function of the baryochemical potential, improving the description previously suggested by Castorina, Kharzeev, and Satz.

Analysis of Different Blade Architectures on small VAWT Performance

NASA Astrophysics Data System (ADS)

Battisti, L.; Brighenti, A.; Benini, E.; Raciti Castelli, M.

2016-09-01

The present paper aims at describing and comparing different small Vertical Axis Wind Turbine (VAWT) architectures, in terms of performance and loads. These characteristics can be highlighted by resorting to the Blade Element-Momentum (BE-M) model, commonly adopted for rotor pre-design and controller assessment. After validating the model with experimental data, the paper focuses on the analysis of VAWT loads depending on some relevant rotor features: blade number (2 and 3), airfoil camber line (comparing symmetrical and asymmetrical profiles) and blade inclination (straight versus helical blade). The effect of such characteristics on both power and thrusts (in the streamwise direction and in the crosswise one) as a function of both the blades azimuthal position and their Tip Speed Ratio (TSR) are presented and widely discussed.

Macromolecule exchange in Cuscuta-host plant interactions.

PubMed

Kim, Gunjune; Westwood, James H

2015-08-01

Cuscuta species (dodders) are parasitic plants that are able to grow on many different host plants and can be destructive to crops. The connections between Cuscuta and its hosts allow movement of not only water and small nutrients, but also macromolecules including mRNA, proteins and viruses. Recent studies show that RNAs move bidirectionally between hosts and parasites and involve a large number of different genes. Although the function of mobile mRNAs has not been demonstrated in this system, small RNAs are also transmitted and a silencing construct expressed in hosts is able to affect expression of the target gene in the parasite. High throughput sequencing of host-parasite associations has the potential to greatly accelerate understanding of this remarkable interaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Profiling protein function with small molecule microarrays

PubMed Central

Winssinger, Nicolas; Ficarro, Scott; Schultz, Peter G.; Harris, Jennifer L.

2002-01-01

The regulation of protein function through posttranslational modification, local environment, and protein–protein interaction is critical to cellular function. The ability to analyze on a genome-wide scale protein functional activity rather than changes in protein abundance or structure would provide important new insights into complex biological processes. Herein, we report the application of a spatially addressable small molecule microarray to an activity-based profile of proteases in crude cell lysates. The potential of this small molecule-based profiling technology is demonstrated by the detection of caspase activation upon induction of apoptosis, characterization of the activated caspase, and inhibition of the caspase-executed apoptotic phenotype using the small molecule inhibitor identified in the microarray-based profile. PMID:12167675

High precision Hugoniot measurements of D2 near maximum compression

NASA Astrophysics Data System (ADS)

Benage, John; Knudson, Marcus; Desjarlais, Michael

2015-11-01

The Hugoniot response of liquid deuterium has been widely studied due to its general importance and to the significant discrepancy in the inferred shock response obtained from early experiments. With improvements in dynamic compression platforms and experimental standards these results have converged and show general agreement with several equation of state (EOS) models, including quantum molecular dynamics (QMD) calculations within the Generalized Gradient Approximation (GGA). This approach to modeling the EOS has also proven quite successful for other materials and is rapidly becoming a standard approach. However, small differences remain among predictions obtained using different local and semi-local density functionals; these small differences show up in the deuterium Hugoniot at ~ 30-40 GPa near the region of maximum compression. Here we present experimental results focusing on that region of the Hugoniot and take advantage of advancements in the platform and standards, resulting in data with significantly higher precision than that obtained in previous studies. These new data may prove to distinguish between the subtle differences predicted by the various density functionals. Results of these experiments will be presented along with comparison to various QMD calculations. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Single-row versus double-row arthroscopic rotator cuff repair in small- to medium-sized tears.

PubMed

Aydin, Nuri; Kocaoglu, Baris; Guven, Osman

2010-07-01

Double-row rotator cuff repair leads to superior cuff integrity and clinical results compared with single-row repair. The study enrolled 68 patients with a full-thickness rotator cuff tear who were divided into 2 groups of 34 patients according to repair technique. The patients were followed-up for at least 2 years. The results were evaluated by Constant score. Despite the biomechanical studies and cadaver studies that proved the superiority of double-row fixation over single-row fixation, our clinical results show no difference in functional outcome between the two methods. It is evident that double-row repair is more technically demanding, expensive, and time-consuming than single-row repair, without providing a significant improvement in clinical results. Comparison between groups did not show significant differences. At the final follow-up, the Constant score was 82.2 in the single-row group and 78.8 in the double-row group. Functional outcome was improved in both groups after surgery, but the difference between the 2 groups was not significant. At long-term follow-up, arthroscopic rotator cuff repair with the double-row technique showed no significant difference in clinical outcome compared with single-row repair in small to medium tears. 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

The effects of ball size distribution on attritor efficiency

NASA Astrophysics Data System (ADS)

Cook, T. M.; Courtney, T. H.

1995-09-01

A study was undertaken to determine how media dynamics are altered when differently sized grinding balls are used in an attritor. Cinematographic techniques identify the extent of segregation/mixing of the differently sized balls within the attritor as a function of impeller rotational velocity and small ball number fraction. This permits determination of rotational velocities needed to most efficiently use the tactic of milling with differently sized media. Cinematographic observations show that the close-packed media array, assumed when balls of the same size are used for milling, is disrupted when differently sized balls are used. Monitoring powder particle numbers as a function of milling time for the situations when the same and differently sized balls are used can be used to assess relative milling efficiencies. Results indicate powder deformation, fracture, and welding are enhanced through employment of differently sized balls. This conclusion is reinforced by observations of microstructural characteristics of powder processed with the different type of media.

Quantum dynamics of a plane pendulum

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

Leibscher, Monika; Schmidt, Burkhard

A semianalytical approach to the quantum dynamics of a plane pendulum is developed, based on Mathieu functions which appear as stationary wave functions. The time-dependent Schroedinger equation is solved for pendular analogs of coherent and squeezed states of a harmonic oscillator, induced by instantaneous changes of the periodic potential energy function. Coherent pendular states are discussed between the harmonic limit for small displacements and the inverted pendulum limit, while squeezed pendular states are shown to interpolate between vibrational and free rotational motion. In the latter case, full and fractional revivals as well as spatiotemporal structures in the time evolution ofmore » the probability densities (quantum carpets) are quantitatively analyzed. Corresponding expressions for the mean orientation are derived in terms of Mathieu functions in time. For periodic double well potentials, different revival schemes, and different quantum carpets are found for the even and odd initial states forming the ground tunneling doublet. Time evolution of the mean alignment allows the separation of states with different parity. Implications for external (rotational) and internal (torsional) motion of molecules induced by intense laser fields are discussed.« less

Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries.

PubMed

Hausmann, Markus

2017-01-02

Biological sex and sex hormones are known to affect functional cerebral asymmetries (FCAs). Men are generally more lateralized than women. The effect size of this sex difference is small but robust. Some of the inconsistencies in the literature may be explained by sex-related hormonal differences. Most studies focusing on neuromodulatory properties of sex hormones on FCAs have investigated women during the menstrual cycle. Although contradictions exist, these studies have typically shown that levels of estradiol and/or progesterone correlate with the degree of FCAs, suggesting that sex differences in FCAs partially depend on hormonal state and day of testing. The results indicate that FCAs are not fixed but are hormone dependent, and as such they can dynamically change within relatively short periods throughout life. Many issues raised in this Mini-Review refer not only to FCAs but also to other aspects of functional brain organization, such as functional connectivity within and between the cerebral hemispheres. Our understanding of sex differences in brain and behavior as well as their clinical relevance will improve significantly if more studies routinely take sex and sex hormones into account. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Longitudinal Modeling of Functional Decline Associated with Pathologic Alzheimer's Disease in Older Persons without Cognitive Impairment.

PubMed

Wang, Dai; Schultz, Tim; Novak, Gerald P; Baker, Susan; Bennett, David A; Narayan, Vaibhav A

2018-01-01

Therapeutic research on Alzheimer's disease (AD) has moved to intercepting the disease at the preclinical phase. Most drugs in late development have focused on the amyloid hypothesis. To understand the magnitude of amyloid-related functional decline and to identify the functional domains sensitive to decline in a preclinical AD population. Data were from the Religious Orders Study and the Rush Memory and Aging Project. Cognitive decline was measured by a modified version of the Alzheimer's Disease Cooperative Study Preclinical Alzheimer Cognitive Composite. The trajectories of functional decline, as measured by the instrumental and basic activities of daily living, were longitudinally modeled in 484 participants without cognitive impairment at baseline and having both a final clinical and a postmortem neuropathology assessment of AD. Individuals with different final clinical diagnoses had different trajectories of cognitive and functional decline. Individuals with AD dementia, minor cognitive impairment, and no cognitive impairment had the most, intermediate, and least declines. While individuals with pathologic AD had significantly more cognitive decline over time than those without, the magnitude of difference in functional decline between these two groups was small. Functional domains such as handling finance and handling medications were more sensitive to decline. Demonstrating the functional benefit of an amyloid-targeting drug represents a significant challenge as elderly people experience functional decline due to a wide range of reasons with limited manifestation attributable to AD neuropathology. More sensitive functional scales focusing on the functional domains sensitive to decline in preclinical AD are needed.

Meet the multifunctional and sexy glycoforms of glycodelin.

PubMed

Lapid, Kfir; Sharon, Nathan

2006-03-01

Glycodelin, a human-secreted glycoprotein that appears in a small number of glycoforms, exhibits diverse biological activities, such as in contraception and immunosuppression. Moreover, different tissue-specific glycoforms appear to mediate diverse functions. Quite unusually, the glycodelin N-linked glycans differ between the male and female glycoforms. The fact that these glycans are fundamental for exerting the physiological activities of the different glycoforms, makes them an interesting target for glycobiology research. This review will focus on the involvement of the glycans in glycodelin activity and compare between the several glycoforms.

On the basis set convergence of electron–electron entanglement measures: helium-like systems

PubMed Central

Hofer, Thomas S.

2013-01-01

A systematic investigation of three different electron–electron entanglement measures, namely the von Neumann, the linear and the occupation number entropy at full configuration interaction level has been performed for the four helium-like systems hydride, helium, Li+ and Be2+ using a large number of different basis sets. The convergence behavior of the resulting energies and entropies revealed that the latter do in general not show the expected strictly monotonic increase upon increase of the one–electron basis. Overall, the three different entanglement measures show good agreement among each other, the largest deviations being observed for small basis sets. The data clearly demonstrates that it is important to consider the nature of the chemical system when investigating entanglement phenomena in the framework of Gaussian type basis sets: while in case of hydride the use of augmentation functions is crucial, the application of core functions greatly improves the accuracy in case of cationic systems such as Li+ and Be2+. In addition, numerical derivatives of the entanglement measures with respect to the nucleic charge have been determined, which proved to be a very sensitive probe of the convergence leading to qualitatively wrong results (i.e., the wrong sign) if too small basis sets are used. PMID:24790952

On the basis set convergence of electron-electron entanglement measures: helium-like systems.

PubMed

Hofer, Thomas S

2013-01-01

A systematic investigation of three different electron-electron entanglement measures, namely the von Neumann, the linear and the occupation number entropy at full configuration interaction level has been performed for the four helium-like systems hydride, helium, Li(+) and Be(2+) using a large number of different basis sets. The convergence behavior of the resulting energies and entropies revealed that the latter do in general not show the expected strictly monotonic increase upon increase of the one-electron basis. Overall, the three different entanglement measures show good agreement among each other, the largest deviations being observed for small basis sets. The data clearly demonstrates that it is important to consider the nature of the chemical system when investigating entanglement phenomena in the framework of Gaussian type basis sets: while in case of hydride the use of augmentation functions is crucial, the application of core functions greatly improves the accuracy in case of cationic systems such as Li(+) and Be(2+). In addition, numerical derivatives of the entanglement measures with respect to the nucleic charge have been determined, which proved to be a very sensitive probe of the convergence leading to qualitatively wrong results (i.e., the wrong sign) if too small basis sets are used.

Gold nanoparticles with different capping systems: an electronic and structural XAS analysis.

PubMed

López-Cartes, C; Rojas, T C; Litrán, R; Martínez-Martínez, D; de la Fuente, J M; Penadés, S; Fernández, A

2005-05-12

Gold nanoparticles (NPs) have been prepared with three different capping systems: a tetralkylammonium salt, an alkanethiol, and a thiol-derivatized neoglycoconjugate. Also gold NPs supported on a porous TiO(2) substrate have been investigated. X-ray absorption spectroscopy (XAS) has been used to determine the electronic behavior of the different capped/supported systems regarding the electron/hole density of d states. Surface and size effects, as well as the role of the microstructure, have been also studied through an exhaustive analysis of the EXAFS (extended X-ray absorption fine structure) data. Very small gold NPs functionalized with thiol-derivatized molecules show an increase in d-hole density at the gold site due to Au-S charge transfer. This effect is overcoming size effects (which lead to a slightly increase of the d-electron density) for high S:Au atomic ratios and core-shell microstructures where an atomically abrupt Au-S interface likely does not exist. It has been also shown that thiol functionalization of very small gold NPs is introducing a strong distortion as compared to fcc order. To the contrary, electron transfer from reduced support oxides to gold NPs can produce a higher increase in d-electron density at the gold site, as compared to naked gold clusters.

Small nucleolar RNAs that guide modification in trypanosomatids: repertoire, targets, genome organisation, and unique functions.

PubMed

Uliel, Shai; Liang, Xue-hai; Unger, Ron; Michaeli, Shulamit

2004-03-29

Small nucleolar RNAs constitute a family of newly discovered non-coding small RNAs, most of which function in guiding RNA modifications. Two prevalent types of modifications are 2'-O-methylation and pseudouridylation. The modification is directed by the formation of a canonical small nucleolar RNA-target duplex. Initially, RNA-guided modification was shown to take place on rRNA, but recent studies suggest that small nuclear RNA, mRNA, tRNA, and the trypanosome spliced leader RNA also undergo guided modifications. Trypanosomes contain more modifications and potentially more small nucleolar RNAs than yeast, and the increased number of modifications may help to preserve ribosome function under adverse environmental conditions during the cycling between the insect and mammalian host. The genome organisation in clusters carrying the two types of small nucleolar RNAs, C/D and H/ACA-like RNAs, resembles that in plants. However, the trypanosomatid H/ACA RNAs are similar to those found in Archaea and are composed of a single hairpin that may represent the primordial H/ACA RNA. In this review we summarise this new field of trypanosome small nucleolar RNAs, emphasising the open questions regarding the number of small nucleolar RNAs, the repertoire, genome organisation, and the unique function of guided modifications in these protozoan parasites.

Cytoskeleton Molecular Motors: Structures and Their Functions in Neuron.

PubMed

Xiao, Qingpin; Hu, Xiaohui; Wei, Zhiyi; Tam, Kin Yip

2016-01-01

Cells make use of molecular motors to transport small molecules, macromolecules and cellular organelles to target region to execute biological functions, which is utmost important for polarized cells, such as neurons. In particular, cytoskeleton motors play fundamental roles in neuron polarization, extension, shape and neurotransmission. Cytoskeleton motors comprise of myosin, kinesin and cytoplasmic dynein. F-actin filaments act as myosin track, while kinesin and cytoplasmic dynein move on microtubules. Cytoskeleton motors work together to build a highly polarized and regulated system in neuronal cells via different molecular mechanisms and functional regulations. This review discusses the structures and working mechanisms of the cytoskeleton motors in neurons.

Changes in Bird Functional Diversity across Multiple Land Uses: Interpretations of Functional Redundancy Depend on Functional Group Identity

PubMed Central

Luck, Gary W.; Carter, Andrew; Smallbone, Lisa

2013-01-01

Examinations of the impact of land-use change on functional diversity link changes in ecological community structure driven by land modification with the consequences for ecosystem function. Yet, most studies have been small-scale, experimental analyses and primarily focussed on plants. There is a lack of research on fauna communities and at large-scales across multiple land uses. We assessed changes in the functional diversity of bird communities across 24 land uses aligned along an intensification gradient. We tested the hypothesis that functional diversity is higher in less intensively used landscapes, documented changes in diversity using four diversity metrics, and examined how functional diversity varied with species richness to identify levels of functional redundancy. Functional diversity, measured using a dendogram-based metric, increased from high to low intensity land uses, but observed values did not differ significantly from randomly-generated expected values. Values for functional evenness and functional divergence did not vary consistently with land-use intensification, although higher than expected values were mostly recorded in high intensity land uses. A total of 16 land uses had lower than expected values for functional dispersion and these were mostly low intensity native vegetation sites. Relations between functional diversity and bird species richness yielded strikingly different patterns for the entire bird community vs. particular functional groups. For all birds and insectivores, functional evenness, divergence and dispersion showed a linear decline with increasing species richness suggesting substantial functional redundancy across communities. However, for nectarivores, frugivores and carnivores, there was a significant hump-shaped or non-significant positive linear relationship between these functional measures and species richness indicating less redundancy. Hump-shaped relationships signify that the most functionally diverse communities occur at intermediate levels of species richness. Interpretations of redundancy thus vary for different functional groups and related ecosystem functions (e.g. pollination), and can be substantially different to relationships involving entire ecological communities. PMID:23696844

Functional Interplay between Small Non-Coding RNAs and RNA Modification in the Brain.

PubMed

Leighton, Laura J; Bredy, Timothy W

2018-06-07

Small non-coding RNAs are essential for transcription, translation and gene regulation in all cell types, but are particularly important in neurons, with known roles in neurodevelopment, neuroplasticity and neurological disease. Many small non-coding RNAs are directly involved in the post-transcriptional modification of other RNA species, while others are themselves substrates for modification, or are functionally modulated by modification of their target RNAs. In this review, we explore the known and potential functions of several distinct classes of small non-coding RNAs in the mammalian brain, focusing on the newly recognised interplay between the epitranscriptome and the activity of small RNAs. We discuss the potential for this relationship to influence the spatial and temporal dynamics of gene activation in the brain, and predict that further research in the field of epitranscriptomics will identify interactions between small RNAs and RNA modifications which are essential for higher order brain functions such as learning and memory.

Does It Say That? Tensions in Teacher Questions When the Text Has the Final Say

ERIC Educational Resources Information Center

Boelé, Amy L.

2017-01-01

Using sociocultural concepts of authoritative and dialogic discourse, I sought to examine 5th-grade teachers' questioning practices during small-group reading instruction to understand the differences between groups reading text on grade level and groups reading texts below grade level. The purpose was also to examine how questions functioned for…

Gene expression profiling of bovine ovarian follicular and luteal cells provides insight into cellular identities and functions

USDA-ARS?s Scientific Manuscript database

After ovulation, somatic cells of the ovarian follicle (theca and granulosa cells) become the small and large luteal cells of the corpus luteum. Aside from known cell type-specific receptors and steroidogenic enzymes, little is known about the differences in the gene expression profiles of these fou...

Children's Faithfulness in Imitating Language Use Varies Cross-culturally, Contingent on Prior Experience

ERIC Educational Resources Information Center

Klinger, Jörn; Mayor, Julien; Bannard, Colin

2016-01-01

Despite its recognized importance for cultural transmission, little is known about the role imitation plays in language learning. Three experiments examine how rates of imitation vary as a function of qualitative differences in the way language is used in a small indigenous community in Oaxaca, Mexico and three Western comparison groups. Data from…

Vertical Migration Potential of Metal Contaminants at Small Arms Firing Ranges, Camp Edwards Military Reservation, Massachusetts.

DTIC Science & Technology

1998-03-01

halloysite on lead concentration in solution 57 Figure 41. Solubility of lead carbonate as a function of pH for a total activity aH2C03...Effects of adsorption by halloysite (a clay) on lead concentration in solution. Contours are equilibrium lead concentrations at different clay

The application and technology of implantable neuromuscular stimulators: an introduction and overview.

PubMed

Jarvis, J C; Salmons, S

2001-01-01

The design of an implantable neuromuscular stimulator represents a trade-off in which the desire to maximise functionality and operational life competes with the need for the implanted device to be small, reliable, safe, and easy to use. In this introduction and overview we consider the basic problems and the different approaches to their solution.

Effect of different tropospheric mapping functions on the TRF, CRF and position time-series estimated from VLBI

NASA Astrophysics Data System (ADS)

Tesmer, Volker; Boehm, Johannes; Heinkelmann, Robert; Schuh, Harald

2007-06-01

This paper compares estimated terrestrial reference frames (TRF) and celestial reference frames (CRF) as well as position time-series in terms of systematic differences, scale, annual signals and station position repeatabilities using four different tropospheric mapping functions (MF): The NMF (Niell Mapping Function) and the recently developed GMF (Global Mapping Function) consist of easy-to-handle stand-alone formulae, whereas the IMF (Isobaric Mapping Function) and the VMF1 (Vienna Mapping Function 1) are determined from numerical weather models. All computations were performed at the Deutsches Geodätisches Forschungsinstitut (DGFI) using the OCCAM 6.1 and DOGS-CS software packages for Very Long Baseline Interferometry (VLBI) data from 1984 until 2005. While it turned out that CRF estimates only slightly depend on the MF used, showing small systematic effects up to 0.025 mas, some station heights of the computed TRF change by up to 13 mm. The best agreement was achieved for the VMF1 and GMF results concerning the TRFs, and for the VMF1 and IMF results concerning scale variations and position time-series. The amplitudes of the annual periodical signals in the time-series of estimated heights differ by up to 5 mm. The best precision in terms of station height repeatability is found for the VMF1, which is 5 7% better than for the other MFs.

A photometric function of planetary surfaces for gourmets

NASA Astrophysics Data System (ADS)

Shkuratov, Yuriy; Korokhin, Viktor; Shevchenko, Vasilij; Mikhalchenko, Olga; Belskaya, Irina; Kaydash, Vadym; Videen, Gorden; Zubko, Evgenij; Velikodsky, Yuriy

2018-03-01

A new photometric model with small number of parameters is presented. The model is based on an assumption that there exist such surfaces for which spatial brightness variations caused by small topography undulations can be reproduced exactly by corresponding spatial variations of albedo. This indistinguishability results in a differential equation suggesting a new photometric function that generalizes, in particular, the Akimov disk-function. Our model provides excellent fits in a wide phase-angle range for integral observations of asteroids of different albedos. We also carried out fitting to integral observations of the Moon and Mercury, confirming difficulties in describing Mercury's phase function at large phase angles, which were also found for the Hapke model. Comparisons of global latitude and longitude trends with our model calculations have shown good coincidence for the Moon. To retrieve the lunar trends, we use the phase-ratio technique, applying it to our telescope observations. Mapping the model parameters using LROC WAC data were carried out for a region comprising the Reiner Gamma formation. This mapping allows us to calculate phase-ratio images of the region, showing at large phase angles systematically steeper phase curves of young craters and smaller steepness for the very Reiner Gamma formation.

Emergence of complex chemistry on an organic monolayer.

PubMed

Prins, Leonard J

2015-07-21

In many origin-of-life scenarios, inorganic materials, such as FeS or mineral clays, play an important role owing to their ability to concentrate and select small organic molecules on their surface and facilitate their chemical transformations into new molecules. However, considering that life is made up of organic matter, at a certain stage during the evolution the role of the inorganic material must have been taken over by organic molecules. How this exactly happened is unclear, and, indeed, a big gap separates the rudimentary level of organization involving inorganic materials and the complex organization of cells, which are the building blocks of life. Over the past years, we have extensively studied the interaction of small molecules with monolayer-protected gold nanoparticles (Au NPs) for the purpose of developing innovative sensing and catalytic systems. During the course of these studies, we realized that the functional role of this system is very similar to that typically attributed to inorganic surfaces in the early stages of life, with the important being difference that the functional properties (molecular recognition, catalysis, signaling, adaptation) originate entirely from the organic monolayer rather than the inorganic support. This led us to the proposition that this system may serve as a model that illustrates how the important role of inorganic surfaces in dictating chemical processes in the early stages of life may have been taken over by organic matter. Here, we reframe our previously obtained results in the context of the origin-of-life question. The following functional roles of Au NPs will be discussed: the ability to concentrate small molecules and create different local populations, the ability to catalyze the chemical transformation of bound molecules, and, finally, the ability to install rudimentary signaling pathways and display primitive adaptive behavior. In particular, we will show that many of the functional properties of the system originate from two features: the presence of metal ions that are complexed in the organic monolayer and the multivalent nature of the system. Complexed metal ions play an important role in determining the affinity and selectivity of the interaction with small molecules, but serve also as regulatory elements for determining how many molecules are bound simultaneously. Importantly, neighboring metal ion complexes also create catalytic pockets in which two metal ions cooperatively catalyze the cleavage of an RNA-model compound. The multivalent nature of the system permits multiple noncovalent interactions with small molecules that enhances the affinity, but is also at the basis of simple signal transduction pathways and adaptive behavior.

Small proteins in cyanobacteria provide a paradigm for the functional analysis of the bacterial micro-proteome.

PubMed

Baumgartner, Desiree; Kopf, Matthias; Klähn, Stephan; Steglich, Claudia; Hess, Wolfgang R

2016-11-28

Despite their versatile functions in multimeric protein complexes, in the modification of enzymatic activities, intercellular communication or regulatory processes, proteins shorter than 80 amino acids (μ-proteins) are a systematically underestimated class of gene products in bacteria. Photosynthetic cyanobacteria provide a paradigm for small protein functions due to extensive work on the photosynthetic apparatus that led to the functional characterization of 19 small proteins of less than 50 amino acids. In analogy, previously unstudied small ORFs with similar degrees of conservation might encode small proteins of high relevance also in other functional contexts. Here we used comparative transcriptomic information available for two model cyanobacteria, Synechocystis sp. PCC 6803 and Synechocystis sp. PCC 6714 for the prediction of small ORFs. We found 293 transcriptional units containing candidate small ORFs ≤80 codons in Synechocystis sp. PCC 6803, also including the known mRNAs encoding small proteins of the photosynthetic apparatus. From these transcriptional units, 146 are shared between the two strains, 42 are shared with the higher plant Arabidopsis thaliana and 25 with E. coli. To verify the existence of the respective μ-proteins in vivo, we selected five genes as examples to which a FLAG tag sequence was added and re-introduced them into Synechocystis sp. PCC 6803. These were the previously annotated gene ssr1169, two newly defined genes norf1 and norf4, as well as nsiR6 (nitrogen stress-induced RNA 6) and hliR1(high light-inducible RNA 1) , which originally were considered non-coding. Upon activation of expression via the Cu 2+. responsive petE promoter or from the native promoters, all five proteins were detected in Western blot experiments. The distribution and conservation of these five genes as well as their regulation of expression and the physico-chemical properties of the encoded proteins underline the likely great bandwidth of small protein functions in bacteria and makes them attractive candidates for functional studies.

Effects of sleep manipulation on cognitive functioning of adolescents: A systematic review.

PubMed

de Bruin, Eduard J; van Run, Chris; Staaks, Janneke; Meijer, Anne Marie

2017-04-01

Adolescents are considered to be at risk for deteriorated cognitive functioning due to insufficient sleep. This systematic review examined the effects of experimental sleep manipulation on adolescent cognitive functioning. Sleep manipulations consisted of total or partial sleep restriction, sleep extension, and sleep improvement. Only articles written in English, with participants' mean age between 10 and 19 y, using objective sleep measures and cognitive performance as outcomes were included. Based on these criteria 16 articles were included. The results showed that the sleep manipulations were successful. Partial sleep restriction had small or no effects on adolescent cognitive functioning. Sleep deprivation studies showed decrements in the psychomotor vigilance task as most consistent finding. Sleep extension and sleep improvement contributed to improvement of working memory. Sleep directly after learning improved memory consolidation. Due to the great diversity of tests and lack of coherent results, decisive conclusions could not be drawn about which domains in particular were influenced by sleep manipulation. Small number of participants, not accounting for the role of sleep quality, individual differences in sleep need, compensatory mechanisms in adolescent sleep and cognitive functioning, and the impurity problem of cognitive tests might explain the absence of more distinct results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantum chemical study of small AlnBm clusters: Structure and physical properties

NASA Astrophysics Data System (ADS)

Loukhovitski, Boris I.; Sharipov, Alexander S.; Starik, Alexander M.

2017-08-01

The structure and physical properties, including rotational constants, characteristic vibrational temperatures, collision diameter, dipole moment, static polarizability, the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), and formation enthalpy of the different isomeric forms of AlnBm clusters with n + m ⩽ 7 are studied using density functional theory. The search of the structure of isomers has been carried employing multistep hierarchical algorithm. Temperature dependencies of thermodynamic functions, such as enthalpy, entropy, and specific heat capacity, have been determined both for the individual isomers and for the ensembles with equilibrium and frozen compositions for the each class of clusters taking into account the anharmonicity of cluster vibrations and the contribution of their excited electronic states. The prospects of the application of small AlnBm clusters as the components of energetic materials are also considered.

Qualitative fusion technique based on information poor system and its application to factor analysis for vibration of rolling bearings

NASA Astrophysics Data System (ADS)

Xia, Xintao; Wang, Zhongyu

2008-10-01

For some methods of stability analysis of a system using statistics, it is difficult to resolve the problems of unknown probability distribution and small sample. Therefore, a novel method is proposed in this paper to resolve these problems. This method is independent of probability distribution, and is useful for small sample systems. After rearrangement of the original data series, the order difference and two polynomial membership functions are introduced to estimate the true value, the lower bound and the supper bound of the system using fuzzy-set theory. Then empirical distribution function is investigated to ensure confidence level above 95%, and the degree of similarity is presented to evaluate stability of the system. Cases of computer simulation investigate stable systems with various probability distribution, unstable systems with linear systematic errors and periodic systematic errors and some mixed systems. The method of analysis for systematic stability is approved.

Galaxy And Mass Assembly (GAMA): the signatures of galaxy interactions as viewed from small scale galaxy clustering

NASA Astrophysics Data System (ADS)

Gunawardhana, M. L. P.; Norberg, P.; Zehavi, I.; Farrow, D. J.; Loveday, J.; Hopkins, A. M.; Davies, L. J. M.; Wang, L.; Alpaslan, M.; Bland-Hawthorn, J.; Brough, S.; Holwerda, B. W.; Owers, M. S.; Wright, A. H.

2018-06-01

Statistical studies of galaxy-galaxy interactions often utilise net change in physical properties of progenitors as a function of the separation between their nuclei to trace both the strength and the observable timescale of their interaction. In this study, we use two-point auto, cross and mark correlation functions to investigate the extent to which small-scale clustering properties of star forming galaxies can be used to gain physical insight into galaxy-galaxy interactions between galaxies of similar optical brightness and stellar mass. The Hα star formers, drawn from the highly spatially complete Galaxy And Mass Assembly (GAMA) survey, show an increase in clustering on small separations. Moreover, the clustering strength shows a strong dependence on optical brightness and stellar mass, where (1) the clustering amplitude of optically brighter galaxies at a given separation is larger than that of optically fainter systems, (2) the small scale clustering properties (e.g. the strength, the scale at which the signal relative to the fiducial power law plateaus) of star forming galaxies appear to differ as a function of increasing optical brightness of galaxies. According to cross and mark correlation analyses, the former result is largely driven by the increased dust content in optically bright star forming galaxies. The latter could be interpreted as evidence of a correlation between interaction-scale and optical brightness of galaxies, where physical evidence of interactions between optically bright star formers, likely hosted within relatively massive halos, persist over larger separations than those between optically faint star formers.

Pain in chemotherapy-induced neuropathy--more than neuropathic?

PubMed

Geber, Christian; Breimhorst, Markus; Burbach, Berenike; Egenolf, Christina; Baier, Bernhard; Fechir, Marcel; Koerber, Juergen; Treede, Rolf-Detlef; Vogt, Thomas; Birklein, Frank

2013-12-01

Chemotherapy-induced neuropathy (CIN) is an adverse effect of chemotherapy. Pain in CIN might comprise neuropathic and nonneuropathic (ie, musculoskeletal) pain components, which might be characterized by pain patterns, electrophysiology, and somatosensory profiling. Included were 146 patients (100 female, 46 male; aged 56 ± 0.8 years) with CIN arising from different chemotherapy regimens. Patients were characterized clinically through nerve conduction studies (NCS) and quantitative sensory testing (QST). Questionnaires for pain (McGill) and anxiety/depression (Hospital Anxiety and Depression Scale) were supplied. Patients were followed-up after 17 days. Large- (61%) and mixed- (35%) fibre neuropathies were more frequent than small-fibre neuropathy (1.4%). The 5 major chemotherapeutic regimens impacted differently on large- but not on small-fibre function and did not predict painfulness. Chronic pain associated with CIN was reported in 41.7%. Painless and painful CIN did not differ in QST profiles or electrophysiological findings, but different somatosensory patterns were found in CIN subgroups (pain at rest [RestP], n = 25; movement-associated pain [MovP], n = 15; both pain characteristics [MovP+RestP], n = 21; or no pain [NonP], n = 85): small-fibre function (cold-detection threshold, CDT: z score: -1.46 ± 0.21, P < 0.01) was most impaired in RestP; mechanical hyperalgesia was exclusively found in MovP (z score: +0.81 ± 0.30, P < 0.05). "Anxiety" discriminated between painful and painless CIN; "CDT" and "anxiety" discriminated between patients with ongoing (RestP) and movement-associated pain (MovP) or pain components (MovP+RestP). The detrimental effect of chemotherapy on large fibres failed to differentiate painful from painless CIN. Patients stratified for musculoskeletal or neuropathic pain, however, differed in psychological and somatosensory parameters. This stratification might allow for the application of a more specific therapy. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

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

Brennan, Mathew D.; Spencer, Michelle J. S., E-mail: t-morishita@aist.go.jp, E-mail: michelle.spencer@rmit.edu.au; Morishita, Tetsuya, E-mail: t-morishita@aist.go.jp, E-mail: michelle.spencer@rmit.edu.au

Silicene is a relatively new material consisting of a two-dimensional sheet of silicon atoms. Functionalisation of silicene with different chemical groups has been suggested as a way to tune its electronic properties. In this work, density functional theory calculations and ab initio molecular dynamics simulations are used to examine the effects of functionalisation with naphthyl or anthracyl groups, which are two examples of small polycyclic aromatic hydrocarbons (PAHs). Different attachment positions on the naphthyl and anthracyl groups were compared, as well as different thicknesses of the silicene nanosheet. It was found that the carbon attachment position farthest from the bondmore » fusing the aromatic rings gave the more stable structures for both functional groups. All structures showed direct band gaps, with tuning of the band gap being achievable by increasing the length of the PAH or the thickness of the silicene. Hence, modifying the functional group or thickness of the silicene can both be used to alter the electronic properties of silicene making it a highly promising material for use in future electronic devices and sensors.« less

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, D. J.; de Bruijn, K. M.; Bouwer, L. M.; de Moel, H.

2016-01-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage functions and maximum damages can have large effects on flood damage estimates. This explanation is then used to quantify the uncertainty in the damage estimates with a Monte Carlo analysis. The Monte Carlo analysis uses a damage function library with 272 functions from seven different flood damage models. The paper shows that the resulting uncertainties in estimated damages are in the order of magnitude of a factor of 2 to 5. The uncertainty is typically larger for flood events with small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Role of p21-activated kinases in cardiovascular development and function.

PubMed

Kelly, Mollie L; Astsaturov, Artyom; Chernoff, Jonathan

2013-11-01

p21-activated kinases (Paks) are a group of six serine/threonine kinases (Pak1-6) that are involved in a variety of biological processes. Recently, Paks, more specifically Pak1, -2, and -4, have been shown to play important roles in cardiovascular development and function in a range of model organisms including zebrafish and mice. These functions include proper morphogenesis and conductance of the heart, cardiac contractility, and development and integrity of the vasculature. The mechanisms underlying these effects are not fully known, but they likely differ among the various Pak isoforms and include both kinase-dependent and -independent functions. In this review, we discuss aspects of Pak function relevant to cardiovascular biology as well as potential therapeutic implications of small-molecule Pak inhibitors in cardiovascular disease.

Cell Elasticity Determines Macrophage Function

PubMed Central

Patel, Naimish R.; Bole, Medhavi; Chen, Cheng; Hardin, Charles C.; Kho, Alvin T.; Mih, Justin; Deng, Linhong; Butler, James; Tschumperlin, Daniel; Fredberg, Jeffrey J.; Krishnan, Ramaswamy; Koziel, Henry

2012-01-01

Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function. PMID:23028423

Perceptually relevant parameters for virtual listening simulation of small room acoustics

PubMed Central

Zahorik, Pavel

2009-01-01

Various physical aspects of room-acoustic simulation techniques have been extensively studied and refined, yet the perceptual attributes of the simulations have received relatively little attention. Here a method of evaluating the perceptual similarity between rooms is described and tested using 15 small-room simulations based on binaural room impulse responses (BRIRs) either measured from a real room or estimated using simple geometrical acoustic modeling techniques. Room size and surface absorption properties were varied, along with aspects of the virtual simulation including the use of individualized head-related transfer function (HRTF) measurements for spatial rendering. Although differences between BRIRs were evident in a variety of physical parameters, a multidimensional scaling analysis revealed that when at-the-ear signal levels were held constant, the rooms differed along just two perceptual dimensions: one related to reverberation time (T60) and one related to interaural coherence (IACC). Modeled rooms were found to differ from measured rooms in this perceptual space, but the differences were relatively small and should be easily correctable through adjustment of T60 and IACC in the model outputs. Results further suggest that spatial rendering using individualized HRTFs offers little benefit over nonindividualized HRTF rendering for room simulation applications where source direction is fixed. PMID:19640043

Posttranscriptional control of neuronal development by microRNA networks.

PubMed

Gao, Fen-Biao

2008-01-01

The proper development of the nervous system requires precise spatial and temporal control of gene expression at both the transcriptional and translational levels. In different experimental model systems, microRNAs (miRNAs) - a class of small, endogenous, noncoding RNAs that control the translation and stability of many mRNAs - are emerging as important regulators of various aspects of neuronal development. Further dissection of the in vivo physiological functions of individual miRNAs promises to offer novel mechanistic insights into the gene regulatory networks that ensure the precise assembly of a functional nervous system.

Ovarian stem cells are always accompanied by very small embryonic-like stem cells in adult mammalian ovary.

PubMed

Bhartiya, Deepa

2015-11-05

Existing dogma that a female is born with fixed number of eggs was challenged by the detection of stem cells in adult mammalian ovary. Data has accumulated in support of ovarian stem cells (OSCs) proliferation, maintenance in culture, formation of germ cell nests and differentiation into oocytes and primordial follicle assembly using different strategies. Flow cytometry analysis identified >8 μm OSCs which are DDX1 positive and are considered equivalent to spermatogonial stem cells (SSCs) in testis. Analysis of both ovarian and testicular smears obtained after enzymatic digestion has led to the identification of an additional stem cell population termed very small embryonic-like stem cells (VSELs). VSELs and OSCs/SSCs differ from each other in their size and OCT-4 expression. VSELs express pluripotent markers including nuclear OCT-4 whereas OSCs/SSCs express cytoplasmic OCT-4 suggesting a differentiated state. VSELs can be studied by flow cytometry as small sized cells which are LIN-/CD45-/Sca-1+. We have reported 0.02 ± 0.008, 0.03 ± 0.017 and 0.08 ± 0.03 % of total cells as VSELs in normal, chemoablated and after FSH treatment to chemoablated mouse ovary. VSELs have remained poorly studied till now because of their very small size and rare occurrence. Spinning cells obtained after enzymatic digestion of ovarian tissue at a speed of 1000G (rather than 1200 rpm) throughout processing allows reliable detection of the VSELs by flow cytometry. VSELs exist in aged, chemoablated and non-functional ovary and providing a healthy niche to support their function offers an interesting strategy to manage infertility.

On the receptivity problem for Goertler vortices: Vortex motions induced by wall roughness

NASA Technical Reports Server (NTRS)

Denier, James P.; Hall, Philip; Seddougui, Sharon

1990-01-01

The receptivity problem for Goertler vortices induced by wall roughness is investigated. The roughness is modelled by small amplitude perturbations to the curved wall over which the flow takes place. The amplitude of these perturbations is taken to be sufficiently small for the induced Goertler vortices to be described by linear theory. The roughness is assumed to vary in the spanwise direction on the boundary layer lengthscale, while in the flow direction the corresponding variation is on the lengthscale over which the wall curvature varies. In fact the latter condition can be relaxed to allow for a faster streamwise roughness variation so long as the variation does not become as fast as that in the spanwise direction. The function which describes the roughness is assumed to be such that its spanwise and streamwise dependences can be separated; this enables progress by taking Fourier or Laplace transforms where appropriate. The cases of isolated and distributed roughness elements are investigated and the coupling coefficient which relates the amplitude of the forcing and the induced vortex amplitude is found asymptotically in the small wavelength limit. It is shown that this coefficient is exponentially small in the latter limit so that it is unlikely that this mode can be stimulated directly by wall roughness. The situation at 0(1) wavelengths is quite different and this is investigated numerically for different forcing functions. It is found that an isolated roughness element induces a vortex field which grows within a wedge at a finite distance downstream of the element. However, immediately downstream of the obstacle the disturbed flow produced by the element decays in amplitude. The receptivity problem at larger Goertler numbers appropriate to relatively large wall curvature is discussed in detail.

Background Noises Versus Intraseasonal Variation Signals: Small vs. Large Convective Cloud Objects From CERES Aqua Observations

NASA Technical Reports Server (NTRS)

Xu, Kuan-Man

2015-01-01

During inactive phases of Madden-Julian Oscillation (MJO), there are plenty of deep but small convective systems and far fewer deep and large ones. During active phases of MJO, a manifestation of an increase in the occurrence of large and deep cloud clusters results from an amplification of large-scale motions by stronger convective heating. This study is designed to quantitatively examine the roles of small and large cloud clusters during the MJO life cycle. We analyze the cloud object data from Aqua CERES (Clouds and the Earth's Radiant Energy System) observations between July 2006 and June 2010 for tropical deep convective (DC) and cirrostratus (CS) cloud object types according to the real-time multivariate MJO index, which assigns the tropics to one of the eight MJO phases each day. The cloud object is a contiguous region of the earth with a single dominant cloud-system type. The criteria for defining these cloud types are overcast footprints and cloud top pressures less than 400 hPa, but DC has higher cloud optical depths (=10) than those of CS (<10). The size distributions, defined as the footprint numbers as a function of cloud object diameters, for particular MJO phases depart greatly from the combined (8-phase) distribution at large cloud-object diameters due to the reduced/increased numbers of cloud objects related to changes in the large-scale environments. The medium diameter corresponding to the combined distribution is determined and used to partition all cloud objects into "small" and "large" groups of a particular phase. The two groups corresponding to the combined distribution have nearly equal numbers of footprints. The medium diameters are 502 km for DC and 310 km for cirrostratus. The range of the variation between two extreme phases (typically, the most active and depressed phases) for the small group is 6-11% in terms of the numbers of cloud objects and the total footprint numbers. The corresponding range for the large group is 19-44%. In terms of the probability density functions of radiative and cloud physical properties, there are virtually no differences between the MJO phases for the small group, but there are significant differences for the large groups for both DC and CS types. These results suggest that the intreseasonal variation signals reside at the large cloud clusters while the small cloud clusters represent the background noises resulting from various types of the tropical waves with different wavenumbers and propagation speeds/directions.

Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

PubMed

Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

2015-01-01

Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy and mean correlation showed regional differences. The presented visualizations were helpful in comparing and evaluating connectivity measures on multiple levels in both studies.

Evolution of high mobility group nucleosome-binding proteins and its implications for vertebrate chromatin specialization.

PubMed

González-Romero, Rodrigo; Eirín-López, José M; Ausió, Juan

2015-01-01

High mobility group (HMG)-N proteins are a family of small nonhistone proteins that bind to nucleosomes (N). Despite the amount of information available on their structure and function, there is an almost complete lack of information on the molecular evolutionary mechanisms leading to their exclusive differentiation. In the present work, we provide evidence suggesting that HMGN lineages constitute independent monophyletic groups derived from a common ancestor prior to the diversification of vertebrates. Based on observations of the functional diversification across vertebrate HMGN proteins and on the extensive silent nucleotide divergence, our results suggest that the long-term evolution of HMGNs occurs under strong purifying selection, resulting from the lineage-specific functional constraints of their different protein domains. Selection analyses on independent lineages suggest that their functional specialization was mediated by bursts of adaptive selection at specific evolutionary times, in a small subset of codons with functional relevance-most notably in HMGN1, and in the rapidly evolving HMGN5. This work provides useful information to our understanding of the specialization imparted on chromatin metabolism by HMGNs, especially on the evolutionary mechanisms underlying their functional differentiation in vertebrates. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Change of Brain Functional Connectivity in Patients With Spinal Cord Injury: Graph Theory Based Approach.

PubMed

Min, Yu-Sun; Chang, Yongmin; Park, Jang Woo; Lee, Jong-Min; Cha, Jungho; Yang, Jin-Ju; Kim, Chul-Hyun; Hwang, Jong-Moon; Yoo, Ji-Na; Jung, Tae-Du

2015-06-01

To investigate the global functional reorganization of the brain following spinal cord injury with graph theory based approach by creating whole brain functional connectivity networks from resting state-functional magnetic resonance imaging (rs-fMRI), characterizing the reorganization of these networks using graph theoretical metrics and to compare these metrics between patients with spinal cord injury (SCI) and age-matched controls. Twenty patients with incomplete cervical SCI (14 males, 6 females; age, 55±14.1 years) and 20 healthy subjects (10 males, 10 females; age, 52.9±13.6 years) participated in this study. To analyze the characteristics of the whole brain network constructed with functional connectivity using rs-fMRI, graph theoretical measures were calculated including clustering coefficient, characteristic path length, global efficiency and small-worldness. Clustering coefficient, global efficiency and small-worldness did not show any difference between controls and SCIs in all density ranges. The normalized characteristic path length to random network was higher in SCI patients than in controls and reached statistical significance at 12%-13% of density (p<0.05, uncorrected). The graph theoretical approach in brain functional connectivity might be helpful to reveal the information processing after SCI. These findings imply that patients with SCI can build on preserved competent brain control. Further analyses, such as topological rearrangement and hub region identification, will be needed for better understanding of neuroplasticity in patients with SCI.

Disrupted small world topology and modular organisation of functional networks in late-life depression with and without amnestic mild cognitive impairment.

PubMed

Li, Wenjun; Douglas Ward, B; Liu, Xiaolin; Chen, Gang; Jones, Jennifer L; Antuono, Piero G; Li, Shi-Jiang; Goveas, Joseph S

2015-10-01

The topological architecture of the whole-brain functional networks in those with and without late-life depression (LLD) and amnestic mild cognitive impairment (aMCI) are unknown. To investigate the differences in the small-world measures and the modular community structure of the functional networks between patients with LLD and aMCI when occurring alone or in combination and cognitively healthy non-depressed controls. 79 elderly participants (LLD (n=23), aMCI (n=18), comorbid LLD and aMCI (n=13), and controls (n=25)) completed neuropsychiatric assessments. Graph theoretical methods were employed on resting-state functional connectivity MRI data. LLD and aMCI comorbidity was associated with the greatest disruptions in functional integration measures (decreased global efficiency and increased path length); both LLD groups showed abnormal functional segregation (reduced local efficiency). The modular network organisation was most variable in the comorbid group, followed by patients with LLD-only. Decreased mean global, local and nodal efficiency metrics were associated with greater depressive symptom severity but not memory performance. Considering the whole brain as a complex network may provide unique insights on the neurobiological underpinnings of LLD with and without cognitive impairment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Structure and function of the mammalian middle ear. I: Large middle ears in small desert mammals.

PubMed

Mason, Matthew J

2016-02-01

Many species of small desert mammals are known to have expanded auditory bullae. The ears of gerbils and heteromyids have been well described, but much less is known about the middle ear anatomy of other desert mammals. In this study, the middle ears of three gerbils (Meriones, Desmodillus and Gerbillurus), two jerboas (Jaculus) and two sengis (elephant-shrews: Macroscelides and Elephantulus) were examined and compared, using micro-computed tomography and light microscopy. Middle ear cavity expansion has occurred in members of all three groups, apparently in association with an essentially 'freely mobile' ossicular morphology and the development of bony tubes for the middle ear arteries. Cavity expansion can occur in different ways, resulting in different subcavity patterns even between different species of gerbils. Having enlarged middle ear cavities aids low-frequency audition, and several adaptive advantages of low-frequency hearing to small desert mammals have been proposed. However, while Macroscelides was found here to have middle ear cavities so large that together they exceed brain volume, the bullae of Elephantulus are considerably smaller. Why middle ear cavities are enlarged in some desert species but not others remains unclear, but it may relate to microhabitat. © 2015 Anatomical Society.

Understanding thermal circulations and near-surface turbulence processes in a small mountain valley

NASA Astrophysics Data System (ADS)

Pardyjak, E.; Dupuy, F.; Durand, P.; Gunawardena, N.; Thierry, H.; Roubin, P.

2017-12-01

The interaction of turbulence and thermal circulations in complex terrain can be significantly different from idealized flat terrain. In particular, near-surface horizontal spatial and temporal variability of winds and thermodynamic variables can be significant event over very small spatial scales. The KASCADE (KAtabatic winds and Stability over CAdarache for Dispersion of Effluents) 2017 conducted from January through March 2017 was designed to address these issues and to ultimately improve prediction of dispersion in complex terrain, particularly during stable atmospheric conditions. We have used a relatively large number of sensors to improve our understanding of the spatial and temporal development, evolution and breakdown of topographically driven flows. KASCADE 2017 consisted of continuous observations and fourteen Intensive Observation Periods (IOPs) conducted in the Cadarache Valley located in southeastern France. The Cadarache Valley is a relatively small valley (5 km x 1 km) with modest slopes and relatively small elevation differences between the valley floor and nearby hilltops ( 100 m). During winter, winds in the valley are light and stably stratified at night leading to thermal circulations as well as complex near-surface atmospheric layering. In this presentation we present results quantifying spatial variability of thermodynamic and turbulence variables as a function of different large -scale forcing conditions (e.g., quiescent conditions, strong westerly flow, and Mistral flow). In addition, we attempt to characterize highly-regular nocturnal horizontal wind meandering and associated turbulence statistics.

Acquired Phototrophy through Retention of Functional Chloroplasts Increases Growth Efficiency of the Sea Slug Elysia viridis

PubMed Central

Baumgartner, Finn A.; Pavia, Henrik; Toth, Gunilla B.

2015-01-01

Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty), and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth) of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR) in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis. PMID:25830355

Improving executive function deficits by playing interactive video-games: secondary analysis of a randomized controlled trial for individuals with chronic stroke.

PubMed

Rozental-Iluz, Clara; Zeilig, Gabi; Weingarden, Harold; Rand, Debbie

2016-08-01

Executive function deficits negatively impact independence and participation in everyday life of individuals with chronic stroke. Therefore, it is important to explore therapeutic interventions to improve executive functions. The aim of this study was to determine the effectiveness of a 3-month interactive video-game group intervention compared to a traditional motor group intervention for improving executive functions in individuals with chronic stroke. This study is a secondary analysis of a single-blind randomized controlled trial for improving factors related to physical activity of individuals with chronic stroke. Assessments were administered pre and post the intervention and at 3-month follow-up by assessors blind to treatment allocation. Thirty-nine individuals with chronic stroke with executive function deficits participated in an interactive video-game group intervention (N.=20) or a traditional group intervention (N.=19). The intervention included two 1-hour group sessions per week for three months, either playing video-games or performing traditional exercises/activities. Executive function deficits were assessed using The Trail Making Test (Parts A and B) and by two performance-based assessments; the Bill Paying Task from the Executive Function Performance Test (EFPT) and the Executive Function Route-Finding Task (EFRT). Following intervention, scores for the Bill Paying Task (EFPT) decreased by 27.5% and 36.6% for the participants in the video-game and traditional intervention, respectively (F=17.3, P<0.000) and continued to decrease in the video-game group with small effect sizes. Effect size was small to medium for the TMT-B (F=0.003, P=0.954) and EFRT (F=1.2, P=0.28), without any statistical significance difference. Interactive video-games provide combined cognitive-motor stimulation and therefore have potential to improve executive functioning of individuals with chronic stroke. Further research is needed. These findings highlight the potential of utilizing interactive video-games in a small group for keeping these individuals active, while maintaining and improving executive functioning especially for individuals with chronic stroke, who have completed their formal rehabilitation.

Neurocognition in early-onset schizophrenia and schizoaffective disorders.

PubMed

Hooper, Stephen R; Giuliano, Anthony J; Youngstrom, Eric A; Breiger, David; Sikich, Linmarie; Frazier, Jean A; Findling, Robert L; McClellan, Jon; Hamer, Robert M; Vitiello, Benedetto; Lieberman, Jeffrey A

2010-01-01

We examined the neuropsychological functioning of youth enrolled in the NIMH funded trial, Treatment of Early-Onset Schizophrenia Spectrum Disorders (TEOSS). We compared the baseline neuropsychological functioning of youth with schizophrenia (SZ, n = 79) to those with schizoaffective disorder (SA, n = 40), and examined the relationship of different variables of illness severity and adaptive behavior to neuropsychological functioning. Participants ranged in age from 8 to 19 years. Diagnostic status was confirmed via structured interview over multiple time points. Domains of neuropsychological functioning included fine-motor, attention, working memory, problem-solving efficiency, inhibitory control, and social cognition. Other variables included intelligence (IQ), academic achievement skills, adaptive behavior, and different measures of illness severity. The two groups did not differ on IQ or on any of the neuropsychological domains. The SZ group performed significantly lower in spelling. A high proportion of individuals in both groups reflected significant intellectual and academic achievement skill deficits. Significant correlations were found between the neurocognitive domains and both illness severity and adaptive behavior variables. There were few differences between the SZ and SA groups on IQ, achievement, or neuropsychological functioning; however, both groups showed significantly high rates of deficits in IQ and basic academic skills. Correlations of the neurocognitive functions with illness severity and adaptive behavior were small to moderate in magnitude. These findings continue to implicate the importance of neurocognitive functioning as a key area of vulnerability in the study of youth with schizophrenia spectrum disorders.

Functional MRI and Multivariate Autoregressive Models

PubMed Central

Rogers, Baxter P.; Katwal, Santosh B.; Morgan, Victoria L.; Asplund, Christopher L.; Gore, John C.

2010-01-01

Connectivity refers to the relationships that exist between different regions of the brain. In the context of functional magnetic resonance imaging (fMRI), it implies a quantifiable relationship between hemodynamic signals from different regions. One aspect of this relationship is the existence of small timing differences in the signals in different regions. Delays of 100 ms or less may be measured with fMRI, and these may reflect important aspects of the manner in which brain circuits respond as well as the overall functional organization of the brain. The multivariate autoregressive time series model has features to recommend it for measuring these delays, and is straightforward to apply to hemodynamic data. In this review, we describe the current usage of the multivariate autoregressive model for fMRI, discuss the issues that arise when it is applied to hemodynamic time series, and consider several extensions. Connectivity measures like Granger causality that are based on the autoregressive model do not always reflect true neuronal connectivity; however, we conclude that careful experimental design could make this methodology quite useful in extending the information obtainable using fMRI. PMID:20444566

Body shape convergence driven by small size optimum in marine angelfishes.

PubMed

Frédérich, Bruno; Santini, Francesco; Konow, Nicolai; Schnitzler, Joseph; Lecchini, David; Alfaro, Michael E

2017-06-01

Convergent evolution of small body size occurs across many vertebrate clades and may reflect an evolutionary response to shared selective pressures. However it remains unclear if other aspects of phenotype undergo convergent evolution in miniaturized lineages. Here we present a comparative analysis of body size and shape evolution in marine angelfishes (Pomacanthidae), a reef fish family characterized by repeated transitions to small body size. We ask if lineages that evolve small sizes show convergent evolution in body shape. Our results reveal that angelfish lineages evolved three different stable size optima with one corresponding to the group of pygmy angelfishes ( Centropyge ). Then, we test if the observed shifts in body size are associated with changes to new adaptive peaks in shape. Our data suggest that independent evolution to small size optima have induced repeated convergence upon deeper body and steeper head profile in Centropyge These traits may favour manoeuvrability and visual awareness in these cryptic species living among corals, illustrating that functional demands on small size may be related to habitat specialization and predator avoidance. The absence of shape convergence in large marine angelfishes also suggests that more severe requirements exist for small than for large size optima. © 2017 The Author(s).

Versatile application of indirect Fourier transformation to structure factor analysis: from X-ray diffraction of molecular liquids to small angle scattering of protein solutions.

PubMed

Fukasawa, Toshiko; Sato, Takaaki

2011-02-28

We highlight versatile applicability of a structure-factor indirect Fourier transformation (IFT) technique, hereafter called SQ-IFT. The original IFT aims at the pair distance distribution function, p(r), of colloidal particles from small angle scattering of X-rays (SAXS) and neutrons (SANS), allowing the conversion of the experimental form factor, P(q), into a more intuitive real-space spatial autocorrelation function. Instead, SQ-IFT is an interaction potential model-free approach to the 'effective' or 'experimental' structure factor to yield the pair correlation functions (PCFs), g(r), of colloidal dispersions like globular protein solutions for small-angle scattering data as well as the radial distribution functions (RDFs) of molecular liquids in liquid diffraction (LD) experiments. We show that SQ-IFT yields accurate RDFs of liquid H(2)O and monohydric alcohol reflecting their local intermolecular structures, in which q-weighted structure function, qH(q), conventionally utilized in many LD studies out of necessity of performing direct Fourier transformation, is no longer required. We also show that SQ-IFT applied to theoretically calculated structure factors for uncharged and charged colloidal dispersions almost perfectly reproduces g(r) obtained as a solution of the Ornstein-Zernike (OZ) equation. We further demonstrate the relevance of SQ-IFT in its practical applications, using SANS effective structure factors of lysozyme solutions reported in recent literatures which revealed the equilibrium cluster formation due to coexisting long range electrostatic repulsion and short range attraction between the proteins. Finally, we present SAXS experiments on human serum albumin (HSA) at different ionic strength and protein concentration, in which we discuss the real space picture of spatial distributions of the proteins via the interaction potential model-free route.

Correlation between standardized assessment of concussion scores and small-world brain network in mild traumatic brain injury.

PubMed

Yan, Yan; Song, Jian; Xu, Guozheng; Yao, Shun; Cao, Chenglong; Li, Chang; Peng, Guibao; Du, Hao

2017-10-01

This study investigated the characteristics of the small-world brain network architecture of patients with mild traumatic brain injury (MTBI), and a correlation between brain functional connectivity network properties in the resting-state fMRI and Standardized Assessment of Concussion (SAC) parameters. The neurological conditions of 22 MTBI patients and 17 normal control individuals were evaluated according to the SAC. Resting-state fMRI was performed in all subjects 3 and 7days after injury respectively. After preprocessing the fMRI data, cortex functional regions were marked using AAL90 and Dosenbach160 templates. The small-world network parameters and areas under the integral curves were computed in the range of sparsity from 0.01 to 0.5. Independent-sample t-tests were used to compare these parameters between the MTBI and control group. Significantly different parameters were investigated for correlations with SAC scores; those that correlated were chosen for further curve fitting. The clustering coefficient, the communication efficiency across in local networks, and the strength of connectivity were all higher in MTBI patients relative to control individuals. Parameters in 160 brain regions of the MTBI group significantly correlated with total SAC score and score for attention; the network parameters may be a quadratic function of attention scores of SAC and a cubic function of SAC scores. MTBI patients were characterized by elevated communication efficiency across global brain regions, and in local networks, and strength of mean connectivity. These features may be associated with brain function compensation. The network parameters significantly correlated with SAC total and attention scores. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combining extrapolation with ghost interaction correction in range-separated ensemble density functional theory for excited states

NASA Astrophysics Data System (ADS)

Alam, Md. Mehboob; Deur, Killian; Knecht, Stefan; Fromager, Emmanuel

2017-11-01

The extrapolation technique of Savin [J. Chem. Phys. 140, 18A509 (2014)], which was initially applied to range-separated ground-state-density-functional Hamiltonians, is adapted in this work to ghost-interaction-corrected (GIC) range-separated ensemble density-functional theory (eDFT) for excited states. While standard extrapolations rely on energies that decay as μ-2 in the large range-separation-parameter μ limit, we show analytically that (approximate) range-separated GIC ensemble energies converge more rapidly (as μ-3) towards their pure wavefunction theory values (μ → +∞ limit), thus requiring a different extrapolation correction. The purpose of such a correction is to further improve on the convergence and, consequently, to obtain more accurate excitation energies for a finite (and, in practice, relatively small) μ value. As a proof of concept, we apply the extrapolation method to He and small molecular systems (viz., H2, HeH+, and LiH), thus considering different types of excitations such as Rydberg, charge transfer, and double excitations. Potential energy profiles of the first three and four singlet Σ+ excitation energies in HeH+ and H2, respectively, are studied with a particular focus on avoided crossings for the latter. Finally, the extraction of individual state energies from the ensemble energy is discussed in the context of range-separated eDFT, as a perspective.

Determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution, appendix 2

NASA Technical Reports Server (NTRS)

Ioup, George E.; Ioup, Juliette W.

1988-01-01

This thesis reviews the technique established to clear channels in the Power Spectral Estimate by applying linear combinations of well known window functions to the autocorrelation function. The need for windowing the auto correlation function is due to the fact that the true auto correlation is not generally used to obtain the Power Spectral Estimate. When applied, the windows serve to reduce the effect that modifies the auto correlation by truncating the data and possibly the autocorrelation has on the Power Spectral Estimate. It has been shown in previous work that a single channel has been cleared, allowing for the detection of a small peak in the presence of a large peak in the Power Spectral Estimate. The utility of this method is dependent on the robustness of it on different input situations. We extend the analysis in this paper, to include clearing up to three channels. We examine the relative positions of the spikes to each other and also the effect of taking different percentages of lags of the auto correlation in the Power Spectral Estimate. This method could have application wherever the Power Spectrum is used. An example of this is beam forming for source location, where a small target can be located next to a large target. Other possibilities extend into seismic data processing. As the method becomes more automated other applications may present themselves.

Change in residential remoteness during the first 5 years of life in an Australian cerebral palsy cohort.

PubMed

DeLacy, Michael J; Louca, Christalla; Smithers-Sheedy, Hayley; McIntyre, Sarah

2016-02-01

To determine if families of children with cerebral palsy living in Australia move to less remote areas between birth and 5 years. Children on the Australian Cerebral Palsy Register (n=3399) born 1996 to 2005, were assigned a remoteness value for family residence at birth and 5 years using a modification of the Australian Statistical Geography Standard. Each value at birth was subtracted from the value at 5 years yielding a positive difference if they moved more remotely, negative difference if they moved less remotely and a value of zero if they did not move or moved to an equally remote residence. The small net increase in remoteness across this cohort was non-significant (p=0.43). Fifty-seven per cent of families changed postcode but only 20% changed remoteness, 11% more remotely, and 9% less remotely. There was a small trend for families with a child with more impaired gross motor function (Gross Motor Function Classification System levels IV and V) to move to a less remote area. This cohort of families with children with cerebral palsy did not appear to move to less remote areas by age 5 years. Remoteness at birth and level of gross motor function seem to have little effect. © 2016 The Authors. Developmental Medicine & Child Neurology © 2016 Mac Keith Press.

Detoxification function of the Arabidopsis sulphotransferase AtSOT12 by sulphonation of xenobiotics.

PubMed

Chen, Jinhua; Gao, Liqiong; Baek, Dongwon; Liu, Chunlin; Ruan, Ying; Shi, Huazhong

2015-08-01

Cytosolic sulphotransferases have been implicated in inactivation of endogenous steroid hormones and detoxification of xenobiotics in human and animals. Yet, the function of plant sulphotransferases in xenobiotic sulphonation and detoxification has not been reported. In this study, we show that the Arabidopsis sulphotransferase AtSOT12 could sulphonate the bacterial-produced toxin cycloheximide. Loss-of-function mutant sot12 exhibited hypersensitive phenotype to cycloheximide, and expression of AtSOT12 protein in yeast cells conferred resistance to this toxic compound. AtSOT12 exhibited broad specificity and could sulphonate a variety of xenobiotics including phenolic and polycyclic compounds. Enzyme kinetics analysis indicated that AtSOT12 has different selectivity for simple phenolics with different side chains, and the position of the side chain in the simple phenolic compounds affects substrate binding affinity and catalytic efficiency. We proposed that the broad specificity and induced production of AtSOT12 may have rendered this enzyme to not only modify endogenous molecules such as salicylic acid as we previously reported, but also sulphonate pathogen-produced toxic small molecules to protect them from infection. Sulphonation of small molecules in plants may constitute a rapid way to inactivate or change the physiochemical properties of biologically active molecules that could have profound effects on plant growth, development and defence. © 2015 John Wiley & Sons Ltd.

Chronic Respiratory Symptoms and Lung Function in Agricultural Workers - Influence of Exposure Duration and Smoking.

PubMed

Stoleski, Saso; Minov, Jordan; Mijakoski, Dragan; Karadzinska-Bislimovska, Jovanka

2015-03-15

Job exposure in agricultural workers often leads to respiratory impairment. To assess the influence of exposure duration and smoking on chronic respiratory symptoms and ventilatory capacity in agricultural workers. A cross-sectional study covered 75 agricultural workers, compared with an equal number of office workers matched by age, exposure duration and smoking status. Standardized questionnaire was used to obtain data on chronic respiratory symptoms, job and smoking history. Lung functional testing was performed by spirometry. The prevalence of respiratory symptoms was higher in agricultural workers, with significant difference for cough (P = 0.034), and dyspnea (P = 0.028). Chronic respiratory symptoms among agricultural workers were significantly associated with duration of exposure (P < 0.05) and daily smoking (P < 0.01), as well as with daily smoking in controls (P < 0.01). The average values of spirometric parameters in exposed workers were significantly different for MEF50 (P = 0.002), MEF75 (P = 0.000), and MEF25-75 (P = 0.049). Obstructive changes in small airways in exposed workers were strongly related to exposure duration (P < 0.05) and smoking (P < 0.01). Agricultural workers with job exposure more than 15 years had more expressed adverse respiratory symptoms and lung function decline. The results confirmed the influence of agricultural exposure and daily smoking on chronic respiratory symptoms and airflow limitation, primarily targeting the small airways.

Prokaryotic cytoskeletons: protein filaments organizing small cells.

PubMed

Wagstaff, James; Löwe, Jan

2018-04-01

Most, if not all, bacterial and archaeal cells contain at least one protein filament system. Although these filament systems in some cases form structures that are very similar to eukaryotic cytoskeletons, the term 'prokaryotic cytoskeletons' is used to refer to many different kinds of protein filaments. Cytoskeletons achieve their functions through polymerization of protein monomers and the resulting ability to access length scales larger than the size of the monomer. Prokaryotic cytoskeletons are involved in many fundamental aspects of prokaryotic cell biology and have important roles in cell shape determination, cell division and nonchromosomal DNA segregation. Some of the filament-forming proteins have been classified into a small number of conserved protein families, for example, the almost ubiquitous tubulin and actin superfamilies. To understand what makes filaments special and how the cytoskeletons they form enable cells to perform essential functions, the structure and function of cytoskeletal molecules and their filaments have been investigated in diverse bacteria and archaea. In this Review, we bring these data together to highlight the diverse ways that linear protein polymers can be used to organize other molecules and structures in bacteria and archaea.

Quantifying (dis)agreement between direct detection experiments in a halo-independent way

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

Feldstein, Brian; Kahlhoefer, Felix, E-mail: brian.feldstein@physics.ox.ac.uk, E-mail: felix.kahlhoefer@physics.ox.ac.uk

We propose an improved method to study recent and near-future dark matter direct detection experiments with small numbers of observed events. Our method determines in a quantitative and halo-independent way whether the experiments point towards a consistent dark matter signal and identifies the best-fit dark matter parameters. To achieve true halo independence, we apply a recently developed method based on finding the velocity distribution that best describes a given set of data. For a quantitative global analysis we construct a likelihood function suitable for small numbers of events, which allows us to determine the best-fit particle physics properties of darkmore » matter considering all experiments simultaneously. Based on this likelihood function we propose a new test statistic that quantifies how well the proposed model fits the data and how large the tension between different direct detection experiments is. We perform Monte Carlo simulations in order to determine the probability distribution function of this test statistic and to calculate the p-value for both the dark matter hypothesis and the background-only hypothesis.« less

Electrostatic field and charge distribution in small charged dielectric droplets

NASA Astrophysics Data System (ADS)

Storozhev, V. B.

2004-08-01

The charge distribution in small dielectric droplets is calculated on the basis of continuum medium approximation. There are considered charged liquid spherical droplets of methanol in the range of nanometer sizes. The problem is solved by the following way. We find the free energy of some ion in dielectric droplet, which is a function of distribution of other ions in the droplet. The probability of location of the ion in some element of volume in the droplet is a function of its free energy in this element of volume. The same approach can be applied to other ions in the droplet. The obtained charge distribution differs considerably from the surface distribution. The curve of the charge distribution in the droplet as a function of radius has maximum near the surface. Relative concentration of charges in the vicinity of the center of the droplet does not equal to zero, and it is the higher, the less is the total charge of the droplet. According to the estimates the model is applicable if the droplet radius is larger than 10 nm.

Nanowire Electron Scattering Spectroscopy

NASA Technical Reports Server (NTRS)

Hunt, Brian; Bronikowsky, Michael; Wong, Eric; VonAllmen, Paul; Oyafuso, Fablano

2009-01-01

Nanowire electron scattering spectroscopy (NESS) has been proposed as the basis of a class of ultra-small, ultralow-power sensors that could be used to detect and identify chemical compounds present in extremely small quantities. State-of-the-art nanowire chemical sensors have already been demonstrated to be capable of detecting a variety of compounds in femtomolar quantities. However, to date, chemically specific sensing of molecules using these sensors has required the use of chemically functionalized nanowires with receptors tailored to individual molecules of interest. While potentially effective, this functionalization requires labor-intensive treatment of many nanowires to sense a broad spectrum of molecules. In contrast, NESS would eliminate the need for chemical functionalization of nanowires and would enable the use of the same sensor to detect and identify multiple compounds. NESS is analogous to Raman spectroscopy, the main difference being that in NESS, one would utilize inelastic scattering of electrons instead of photons to determine molecular vibrational energy levels. More specifically, in NESS, one would exploit inelastic scattering of electrons by low-lying vibrational quantum states of molecules attached to a nanowire or nanotube.

Calculation of self–shielding factor for neutron activation experiments using GEANT4 and MCNP

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

Romero–Barrientos, Jaime, E-mail: jaromero@ing.uchile.cl; Universidad de Chile, DFI, Facultad de Ciencias Físicas Y Matemáticas, Avenida Blanco Encalada 2008, Santiago; Molina, F.

2016-07-07

The neutron self–shielding factor G as a function of the neutron energy was obtained for 14 pure metallic samples in 1000 isolethargic energy bins from 1·10{sup −5}eV to 2·10{sup 7}eV using Monte Carlo simulations in GEANT4 and MCNP6. The comparison of these two Monte Carlo codes shows small differences in the final self–shielding factor mostly due to the different cross section databases that each program uses.

The small heat shock protein Hsp27: Present understanding and future prospects.

PubMed

Singh, Manish Kumar; Sharma, Bechan; Tiwari, Pramod K

2017-10-01

Heat shock proteins are important for maintaining protein homeostasis and cell survival. Among different classes of highly conserved Hsps, low molecular weight Hsps (sHsps) have significant place, particularly Hsp27, whose role has been demonstrated in wide range of biological processes, including development, immunity, diseases and therapy. In this review, the structure and functions of Hsp27 and related genes, their role in different cellular processes as well as in stress tolerance, is highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Signatures in vibrational and UV-visible absorption spectra for identifying cyclic hydrocarbons by graphene fragments.

PubMed

Meng, Yan; Wu, Qi; Chen, Lei; Wangmo, Sonam; Gao, Yang; Wang, Zhigang; Zhang, Rui-Qin; Ding, Dajun; Niehaus, Thomas A; Frauenheim, Thomas

2013-12-21

To promote possible applications of graphene in molecular identification based on stacking effects, in particular in recognizing aromatic amino acids and even sequencing nucleobases in life sciences, we comprehensively study the interaction between graphene segments and different cyclic organic hydrocarbons including benzene (C6H6), cyclohexane (C6H12), benzyne (C6H4), cyclohexene (C6H10), 1,3-cyclohexadiene (C6H8(1)) and 1,4-cyclohexadiene (C6H8(2)), using the density-functional tight-binding (DFTB) method. Interestingly, we find obviously different characteristics in Raman vibrational and ultraviolet visible absorption spectra of the small molecules adsorbed on the graphene sheet. Specifically, we find that both spectra involve clearly different characteristic peaks, belonging to the different small molecules upon adsorption, with the ones of ionized molecules being more substantial. Further analysis shows that the adsorptions are almost all due to the presence of dispersion energy in neutral cases and involve charge transfer from the graphene to the small molecules. In contrast, the main binding force in the ionic adsorption systems is the electronic interaction. The results present clear signatures that can be used to recognize different kinds of aromatic hydrocarbon rings on graphene sheets. We expect that our findings will be helpful for designing molecular recognition devices using graphene.

Thyroid function and obesity.

PubMed

Laurberg, Peter; Knudsen, Nils; Andersen, Stig; Carlé, Allan; Pedersen, Inge Bülow; Karmisholt, Jesper

2012-10-01

Important interaction exists between thyroid function, weight control, and obesity. Several mechanisms seem to be involved, and in studies of groups of people the pattern of thyroid function tests depends on the balance of obesity and underlying thyroid disease in the cohort studied. Obese people with a normal thyroid gland tend to have activation of the hypothalamic-pituitary-thyroid axis with higher serum TSH and thyroid hormones in serum. On the other hand, small differences in thyroid function are associated with up to 5 kg difference in body weight. The weight loss after therapy of overt hypothyroidism is caused by excretion of water bound in tissues (myxoedema). Many patients treated for hyperthyroidism experience a gain of more weight than they lost during the active phase of the disease. The mechanism for this excessive weight gain has not been fully elucidated. New studies on the relation between L-T3 therapy and weight control are discussed. The interaction between weight control and therapy of thyroid disease is important to many patients and it should be studied in more detail.

Columnar organization of orientation domains in V1

NASA Astrophysics Data System (ADS)

Liedtke, Joscha; Wolf, Fred

In the primary visual cortex (V1) of primates and carnivores, the functional architecture of basic stimulus selectivities appears similar across cortical layers (Hubel & Wiesel, 1962) justifying the use of two-dimensional cortical models and disregarding organization in the third dimension. Here we show theoretically that already small deviations from an exact columnar organization lead to non-trivial three-dimensional functional structures. We extend two-dimensional random field models (Schnabel et al., 2007) to a three-dimensional cortex by keeping a typical scale in each layer and introducing a correlation length in the third, columnar dimension. We examine in detail the three-dimensional functional architecture for different cortical geometries with different columnar correlation lengths. We find that (i) topological defect lines are generally curved and (ii) for large cortical curvatures closed loops and reconnecting topological defect lines appear. This theory extends the class of random field models by introducing a columnar dimension and provides a systematic statistical assessment of the three-dimensional functional architecture of V1 (see also (Tanaka et al., 2011)).

Executive function deficits in short-term abstinent cannabis users.

PubMed

McHale, Sue; Hunt, Nigel

2008-07-01

Few cognitive tasks are adequately sensitive to show the small decrements in performance in abstinent chronic cannabis users. In this series of three experiments we set out to demonstrate a variety of tasks that are sufficiently sensitive to show differences in visual memory, verbal memory, everyday memory and executive function between controls and cannabis users. A series of three studies explored cognitive function deficits in cannabis users (phonemic verbal fluency, visual recognition and immediate and delayed recall, and prospective memory) in short-term abstinent cannabis users. Participants were selected using snowball sampling, with cannabis users being compared to a standard control group and a tobacco-use control group. The cannabis users, compared to both control groups, had deficits on verbal fluency, visual recognition, delayed visual recall, and short- and long-interval prospective memory. There were no differences for immediate visual recall. These findings suggest that cannabis use leads to impaired executive function. Further research needs to explore the longer term impact of cannabis use. Copyright 2008 John Wiley & Sons, Ltd.

The Angular Three-Point Correlation Function in the Quasi-linear Regime

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

Buchalter, Ari; Kamionkowski, Marc; Jaffe, Andrew H.

2000-02-10

We calculate the normalized angular three-point correlation function (3PCF), q, as well as the normalized angular skewness, s{sub 3}, assuming the small-angle approximation, for a biased mass distribution in flat and open cold dark matter (CDM) models with Gaussian initial conditions. The leading-order perturbative results incorporate the explicit dependence on the cosmological parameters, the shape of the CDM transfer function, the linear evolution of the power spectrum, the form of the assumed redshift distribution function, and linear and nonlinear biasing, which may be evolving. Results are presented for different redshift distributions, including that appropriate for the APM Galaxy Survey, asmore » well as for a survey with a mean redshift of z{approx_equal}1 (such as the VLA FIRST Survey). Qualitatively, many of the results found for s{sub 3} and q are similar to those obtained in a related treatment of the spatial skewness and 3PCF, such as a leading-order correction to the standard result for s{sub 3} in the case of nonlinear bias (as defined for unsmoothed density fields), and the sensitivity of the configuration dependence of q to both cosmological and biasing models. We show that since angular correlation functions (CFs) are sensitive to clustering over a range of redshifts, the various evolutionary dependences included in our predictions imply that measurements of q in a deep survey might better discriminate between models with different histories, such as evolving versus nonevolving bias, that can have similar spatial CFs at low redshift. Our calculations employ a derived equation, valid for open, closed, and flat models, to obtain the angular bispectrum from the spatial bispectrum in the small-angle approximation. (c) (c) 2000. The American Astronomical Society.« less

Subsurface characterization with localized ensemble Kalman filter employing adaptive thresholding

NASA Astrophysics Data System (ADS)

Delijani, Ebrahim Biniaz; Pishvaie, Mahmoud Reza; Boozarjomehry, Ramin Bozorgmehry

2014-07-01

Ensemble Kalman filter, EnKF, as a Monte Carlo sequential data assimilation method has emerged promisingly for subsurface media characterization during past decade. Due to high computational cost of large ensemble size, EnKF is limited to small ensemble set in practice. This results in appearance of spurious correlation in covariance structure leading to incorrect or probable divergence of updated realizations. In this paper, a universal/adaptive thresholding method is presented to remove and/or mitigate spurious correlation problem in the forecast covariance matrix. This method is, then, extended to regularize Kalman gain directly. Four different thresholding functions have been considered to threshold forecast covariance and gain matrices. These include hard, soft, lasso and Smoothly Clipped Absolute Deviation (SCAD) functions. Three benchmarks are used to evaluate the performances of these methods. These benchmarks include a small 1D linear model and two 2D water flooding (in petroleum reservoirs) cases whose levels of heterogeneity/nonlinearity are different. It should be noted that beside the adaptive thresholding, the standard distance dependant localization and bootstrap Kalman gain are also implemented for comparison purposes. We assessed each setup with different ensemble sets to investigate the sensitivity of each method on ensemble size. The results indicate that thresholding of forecast covariance yields more reliable performance than Kalman gain. Among thresholding function, SCAD is more robust for both covariance and gain estimation. Our analyses emphasize that not all assimilation cycles do require thresholding and it should be performed wisely during the early assimilation cycles. The proposed scheme of adaptive thresholding outperforms other methods for subsurface characterization of underlying benchmarks.

Analysis of simian virus 40 small t antigen-induced progression of rat F111 cells minimally transformed by large T antigen.

PubMed Central

Zerrahn, J; Deppert, W

1993-01-01

Minimal transformants of rat F111 fibroblasts were established after infection with the large T antigen (large T)-encoding retroviral expression vector pZIPTEX (M. Brown, M. McCormack, K. Zinn, M. Farrell, I. Bikel, and D. Livingston, J. Virol. 60:290-293, 1986). Coexpression of small t antigen (small t) in these cells efficiently led to their progression toward a significantly enhanced transformed phenotype. Small t forms a complex with phosphatase 2A and thereby might influence cellular phosphorylation processes, including the phosphorylation of large T. Since phosphorylation can modulate the transforming activity of large T, we asked whether the phosphorylation status of large T in minimally transformed cells might differ from that of large T in maximally transformed FR(wt648) cells and whether it might be altered by coexpression of small t. We found the phosphate turnover on large T in minimally transformed cells significantly different from that in fully transformed cells. This resulted in underphosphorylation of large T in minimally transformed cells at phosphorylation sites previously shown to be involved in the regulation of the transforming activity of large T. However, coexpression of small t in the minimally transformed cells did not alter the phosphate turnover on large T during progression; i.e., it did not induce a change in the steady-state phosphorylation of large T. This suggests that the helper function of small t during the progression of these cells was not mediated by modulating phosphatase 2A activity toward large T. Images PMID:8382310

White matter tracts of speech and language.

PubMed

Smits, Marion; Jiskoot, Lize C; Papma, Janne M

2014-10-01

Diffusion tensor imaging (DTI) has been used to investigate the white matter (WM) tracts underlying the perisylvian cortical regions known to be associated with language function. The arcuate fasciculus is composed of 3 segments (1 long and 2 short) whose separate functions correlate with traditional models of conductive and transcortical motor or sensory aphasia, respectively. DTI mapping of language fibers is useful in presurgical planning for patients with dominant hemisphere tumors, particularly when combined with functional magnetic resonance imaging. DTI has found damage to language networks in stroke patients and has the potential to influence poststroke rehabilitation and treatment. Assessment of the WM tracts involved in the default mode network has been found to correlate with mild cognitive impairment, potentially explaining language deficits in patients with apparently mild small vessel ischemic disease. Different patterns of involvement of language-related WM structures appear to correlate with different clinical subtypes of primary progressive aphasias. Copyright © 2014 Elsevier Inc. All rights reserved.

Negative differential resistance and switch behavior of T-BxNy (x, y = 5, 6, 11) molecular junctions

NASA Astrophysics Data System (ADS)

Wang, Shi-Liang; Yang, Chuan-Lu; Wang, Mei-Shan; Ma, Xiao-Guang; Xin, Jian-Guo

2017-05-01

The electronic transport properties of T-BxNy (x, y = 5, 6, 11) molecular junction are investigated based on first-principle density functional theory and non-equilibrium Green's function method. Strong negative differential resistance (NDR) behavior is observed for T-B5N6 molecule under negative and positive bias voltages, with an obvious switch effect for T-B6N5. However, only small NDR is shown for the complex of the two molecules. The projected device density of states, the spatial distribution of molecular orbitals, and the effect of transmission spectra under various bias voltages on the electronic transport properties are analyzed. The obvious effect of bias voltage on the changes in the electronic distribution of frontier molecular orbitals is responsible for the NDR or switch behavior. Therefore, different functional molecular devices can be obtained with different structures of T-BxNy.

Phase dynamics of coupled oscillators reconstructed from data

NASA Astrophysics Data System (ADS)

Rosenblum, Michael; Kralemann, Bjoern; Pikovsky, Arkady

2013-03-01

We present a technique for invariant reconstruction of the phase dynamics equations for coupled oscillators from data. The invariant description is achieved by means of a transformation of phase estimates (protophases) obtained from general scalar observables to genuine phases. Staring from the bivariate data, we obtain the coupling functions in terms of these phases. We discuss the importance of the protophase-to-phase transformation for characterization of strength and directionality of interaction. To illustrate the technique we analyse the cardio-respiratory interaction on healthy humans. Our invariant approach is confirmed by high similarity of the coupling functions obtained from different observables of the cardiac system. Next, we generalize the technique to cover the case of small networks of coupled periodic units. We use the partial norms of the reconstructed coupling functions to quantify directed coupling between the oscillators. We illustrate the method by different network motifs for three coupled oscillators. We also discuss nonlinear effects in coupling.

The effect of vilazodone on sexual function during the treatment of major depressive disorder.

PubMed

Clayton, Anita H; Kennedy, Sidney H; Edwards, John B; Gallipoli, Susan; Reed, Carol R

2013-10-01

  Sexual dysfunction is common in major depressive disorder (MDD), and many serotonergic antidepressants adversely affect sexual function. Vilazodone, a novel serotonin (5-HT) reuptake inhibitor and 5-HT1A partial agonist approved for MDD, exerts its effects at the 5-HT transporter and at both presynaptic and postsynaptic 5-HT1A receptors. This mechanism may limit sexual dysfunction.   To summarize effects of vilazodone (40 mg/day, with food) on sexual function in adults with MDD.   Data sources were three Phase III studies: two 8-week, placebo-controlled studies (NCT00285376 and NCT00683592) and a 52-week open-label study (NCT00644358). Sexual function was assessed by analyzing changes from baseline to end of treatment (EOT) using validated measures.   Arizona Sexual Experience Scale or Changes in Sexual Functioning Questionnaire.   Population included 869 patients (vilazodone, 436; placebo, 433) from placebo-controlled studies and 599 patients from the open-label study. Sexual dysfunction prevalence was high (50%, men; 68%, women) before treatment and declined during treatment in vilazodone and placebo groups, indicating improvement on average. At EOT, stable/improved sexual function was observed in ≥91% of patients in placebo-controlled studies; treatment group differences in sexual dysfunction at EOT were not statistically significant for either sex. Differences vs. placebo in changes from baseline of sexual function scores were small and were generally not statistically significant; effect sizes (Cohen's D) were generally of low magnitude. In the placebo-controlled studies, 8.0% of vilazodone-treated patients and 0.9% of placebo-treated patients reported ≥1 sexual-function-related treatment-emergent adverse event (P<0.001).   Half of men and two thirds of women with MDD had sexual dysfunction at baseline; sexual function improved on average in both vilazodone and placebo groups. Results suggest that vilazodone may have a small adverse impact on sexual function in adults with MDD relative to the high prevalence of sexual dysfunction at baseline. © 2012 International Society for Sexual Medicine.

The effect of solvent upon molecularly thin rotaxane film formation

NASA Astrophysics Data System (ADS)

Farrell, Alan A.; Kay, Euan R.; Bottari, Giovanni; Leigh, David A.; Jarvis, Suzanne P.

2007-05-01

We have investigated variations in molecularly thin rotaxane films deposited by solvent evaporation, using atomic force microscopy (AFM). Small changes in rotaxane structure result in significant differences in film morphology. The addition of exo-pyridyl moietes to the rotaxane macrocycle results in uniform domains having orientations corresponding to the underlying substrate lattice, while a larger, less symmetric molecule results in a greater lattice mismatch and smaller domain sizes. We have measured differences in film heights both as a function of the solvent of deposition and as a function of surface coverage of rotaxanes. Based on these observations we describe how the use of solvents with higher hydrogen-bond basicity results in films which are more likely to favour sub-molecular motion.

Cftr gene targeting in mouse embryonic stem cells mediated by Small Fragment Homologous Replacement (SFHR).

PubMed

Sangiuolo, Federica; Scaldaferri, Maria Lucia; Filareto, Antonio; Spitalieri, Paola; Guerra, Lorenzo; Favia, Maria; Caroppo, Rosa; Mango, Ruggiero; Bruscia, Emanuela; Gruenert, Dieter C; Casavola, Valeria; De Felici, Massimo; Novelli, Giuseppe

2008-01-01

Different gene targeting approaches have been developed to modify endogenous genomic DNA in both human and mouse cells. Briefly, the process involves the targeting of a specific mutation in situ leading to the gene correction and the restoration of a normal gene function. Most of these protocols with therapeutic potential are oligonucleotide based, and rely on endogenous enzymatic pathways. One gene targeting approach, "Small Fragment Homologous Replacement (SFHR)", has been found to be effective in modifying genomic DNA. This approach uses small DNA fragments (SDF) to target specific genomic loci and induce sequence and subsequent phenotypic alterations. This study shows that SFHR can stably introduce a 3-bp deletion (deltaF508, the most frequent cystic fibrosis (CF) mutation) into the Cftr (CF Transmembrane Conductance Regulator) locus in the mouse embryonic stem (ES) cell genome. After transfection of deltaF508-SDF into murine ES cells, SFHR-mediated modification was evaluated at the molecular levels on DNA and mRNA obtained from transfected ES cells. About 12% of transcript corresponding to deleted allele was detected, while 60% of the electroporated cells completely lost any measurable CFTR-dependent chloride efflux. The data indicate that the SFHR technique can be used to effectively target and modify genomic sequences in ES cells. Once the SFHR-modified ES cells differentiate into different cell lineages they can be useful for elucidating tissue-specific gene function and for the development of transplantation-based cellular and therapeutic protocols.

To Jump or Cycle? Monitoring Neuromuscular Function in Rugby Union Players.

PubMed

Roe, Gregory; Darrall-Jones, Joshua; Till, Kevin; Phibbs, Padraic; Read, Dale; Weakley, Jonathon; Jones, Ben

2017-05-01

To evaluate changes in performance of a 6-s cycle-ergometer test (CET) and countermovement jump (CMJ) during a 6-wk training block in professional rugby union players. Twelve young professional rugby union players performed 2 CETs and CMJs on the 1st and 4th mornings of every week before the commencement of daily training during a 6-wk training block. Standardized changes in the highest score of 2 CET and CMJ efforts were assessed using linear mixed modeling and magnitude-based inferences. After increases in training load during wk 3 to 5, moderate decreases in CMJ peak and mean power and small decreases in flight time were observed during wk 5 and 6 that were very likely to almost certainly greater than the smallest worthwhile change (SWC), suggesting neuromuscular fatigue. However, only small decreases, possibly greater than the SWC, were observed in CET peak power. Changes in CMJ peak and mean power were moderately greater than in CET peak power during this period, while the difference between flight time and CET peak power was small. The greater weekly changes in CMJ metrics in comparison with CET may indicate differences in the capacities of these tests to measure training-induced lower-body neuromuscular fatigue in rugby union players. However, future research is needed to ascertain the specific modes of training that elicit changes in CMJ and CET to determine the efficacy of each test for monitoring neuromuscular function in rugby union players.

Neurocognition in individuals with incidentally-identified meningioma.

PubMed

Butts, Alissa M; Weigand, Stephen; Brown, Paul D; Petersen, Ronald C; Jack, Clifford R; Machulda, Mary M; Cerhan, Jane H

2017-08-01

Meningiomas are primary intracranial tumors that are often asymptomatic. To our knowledge, no study has attempted to describe neurocognitive function in patients with incidentally-discovered meningioma. We utilized the Mayo Clinic Study of Aging (MCSA), which is a population-based sample of Olmsted County, Minnesota residents that includes neuropsychological testing and brain MRI approximately every 15 months. Using a text search of radiologists' notes of 2402 MCSA individuals (mean age 77 years, scanned between 2004 and 2014) we identified 48 eligible subjects (2%) who had at least one meningioma. Most meningiomas were small (90% <3 cm). We matched each of the 48 subjects to 5 non-demented MCSA controls (n = 240) on age, sex, and education. Cognitive domains assessed included memory, attention-executive function, language, and visuospatial. More women (67%) had a meningioma than men (33%). Groups did not differ on prevalence of Mild Cognitive Impairment (Meningioma = 19%, Controls = 13%). Across cognitive domains, we observed similar performance for the two groups (p's ≥ 0.21). Subtle differences emerged in memory and language domains (p = 0.05 and p = 0.11) when we divided the Meningioma group by tumor location, wherein the small group with an infratentorial tumor performed more poorly than controls globally as well as on select memory and language measures. Our findings suggest that small meningiomas are generally cognitively benign, but that may change as the tumor evolves, and might be impacted by other factors such as meningioma location.

Role of Ongoing, Intrinsic Activity of Neuronal Populations for Quantitative Neuroimaging of Functional Magnetic Resonance Imaging–Based Networks

PubMed Central

Herman, Peter; Sanganahalli, Basavaraju G.; Coman, Daniel; Blumenfeld, Hal; Rothman, Douglas L.

2011-01-01

Abstract A primary objective in neuroscience is to determine how neuronal populations process information within networks. In humans and animal models, functional magnetic resonance imaging (fMRI) is gaining increasing popularity for network mapping. Although neuroimaging with fMRI—conducted with or without tasks—is actively discovering new brain networks, current fMRI data analysis schemes disregard the importance of the total neuronal activity in a region. In task fMRI experiments, the baseline is differenced away to disclose areas of small evoked changes in the blood oxygenation level-dependent (BOLD) signal. In resting-state fMRI experiments, the spotlight is on regions revealed by correlations of tiny fluctuations in the baseline (or spontaneous) BOLD signal. Interpretation of fMRI-based networks is obscured further, because the BOLD signal indirectly reflects neuronal activity, and difference/correlation maps are thresholded. Since the small changes of BOLD signal typically observed in cognitive fMRI experiments represent a minimal fraction of the total energy/activity in a given area, the relevance of fMRI-based networks is uncertain, because the majority of neuronal energy/activity is ignored. Thus, another alternative for quantitative neuroimaging of fMRI-based networks is a perspective in which the activity of a neuronal population is accounted for by the demanded oxidative energy (CMRO2). In this article, we argue that network mapping can be improved by including neuronal energy/activity of both the information about baseline and small differences/fluctuations of BOLD signal. Thus, total energy/activity information can be obtained through use of calibrated fMRI to quantify differences of ΔCMRO2 and through resting-state positron emission tomography/magnetic resonance spectroscopy measurements for average CMRO2. PMID:22433047

A Comparative Study of Standardized Infinity Reference and Average Reference for EEG of Three Typical Brain States

PubMed Central

Zheng, Gaoxing; Qi, Xiaoying; Li, Yuzhu; Zhang, Wei; Yu, Yuguo

2018-01-01

The choice of different reference electrodes plays an important role in deciphering the functional meaning of electroencephalography (EEG) signals. In recent years, the infinity zero reference using the reference electrode standard technique (REST) has been increasingly applied, while the average reference (AR) was generally advocated as the best available reference option in previous classical EEG studies. Here, we designed EEG experiments and performed a direct comparison between the influences of REST and AR on EEG-revealed brain activity features for three typical brain behavior states (eyes-closed, eyes-open and music-listening). The analysis results revealed the following observations: (1) there is no significant difference in the alpha-wave-blocking effect during the eyes-open state compared with the eyes-closed state for both REST and AR references; (2) there was clear frontal EEG asymmetry during the resting state, and the degree of lateralization under REST was higher than that under AR; (3) the global brain functional connectivity density (FCD) and local FCD have higher values for REST than for AR under different behavior states; and (4) the value of the small-world network characteristic in the eyes-closed state is significantly (in full, alpha, beta and gamma frequency bands) higher than that in the eyes-open state, and the small-world effect under the REST reference is higher than that under AR. In addition, the music-listening state has a higher small-world network effect than the eyes-closed state. The above results suggest that typical EEG features might be more clearly presented by applying the REST reference than by applying AR when using a 64-channel recording. PMID:29593490

A domain unique to plant RanGAP is responsible for its targeting to the plant nuclear rim

PubMed Central

Rose, Annkatrin; Meier, Iris

2001-01-01

Ran is a small signaling GTPase that is involved in nucleocytoplasmic transport. Two additional functions of animal Ran in the formation of spindle asters and the reassembly of the nuclear envelope in mitotic cells have been recently reported. In contrast to Ras or Rho, Ran is not associated with membranes. Instead, the spatial sequestering of its accessory proteins, the Ran GTPase-activating protein RanGAP and the nucleotide exchange factor RCC1, appears to define the local concentration of RanGTP vs. RanGDP involved in signaling. Mammalian RanGAP is bound to the nuclear pore by a mechanism involving the attachment of small ubiquitin-related modifier protein (SUMO) to its C terminus and the subsequent binding of the SUMOylated domain to the nucleoporin Nup358. Here we show that plant RanGAP utilizes a different mechanism for nuclear envelope association, involving a novel targeting domain that appears to be unique to plants. The N-terminal WPP domain is highly conserved among plant RanGAPs and the small, plant-specific nuclear envelope-associated protein MAF1, but not present in yeast or animal RanGAP. Confocal laser scanning microscopy of green fluorescent protein (GFP) fusion proteins showed that it is necessary for RanGAP targeting and sufficient to target the heterologous protein GFP to the plant nuclear rim. The highly conserved tryptophan and proline residues of the WPP motif are necessary for its function. The 110-aa WPP domain is the first nuclear-envelope targeting domain identified in plants. Its fundamental difference to its mammalian counterpart implies that different mechanisms have evolved in plants and animals to anchor RanGAP at the nuclear surface. PMID:11752475

[Carbon Source Utilization Characteristics of Soil Microbial Community for Apple Orchard with Interplanting Herbage].

PubMed

Du, Yi-fei; Fang, Kai-kai; Wang, Zhi-kang; Li, Hui-ke; Mao, Peng-juan; Zhang, Xiang-xu; Wang, Jing

2015-11-01

As soil fertility in apple orchard with clean tillage is declined continuously, interplanting herbage in orchard, which is a new orchard management model, plays an important role in improving orchard soil conditions. By using biolog micro-plate technique, this paper studied the functional diversity of soil microbial community under four species of management model in apple orchards, including clear tillage model, interplanting white clover model, interplanting small crown flower model and interplanting cocksfoot model, and the carbon source utilization characteristics of microbial community were explored, which could provide a reference for revealing driving mechanism of ecological process of orchard soil. The results showed that the functional diversity of microbial community had a significant difference among different treatments and in the order of white clover > small crown flower > cocksfoot > clear tillage. The correlation analysis showed that the average well color development (AWCD), Shannon index, Richness index and McIntosh index were all highly significantly positively correlated with soil organic carbon, total nitrogen, microbial biomass carbon, and Shannon index was significantly positively correlated with soil pH. The principal component analysis and the fingerprints of the physiological carbon metabolism of the microbial community demonstrated that grass treatments improved carbon source metabolic ability of soil microbial community, and the soil microbes with perennial legumes (White Clover and small crown flower) had a significantly higher utilization rate in carbohydrates (N-Acetyl-D-Glucosamine, D-Mannitol, β-Methyl-D-Glucoside), amino acids (Glycyl-L-Glutamic acid, L-Serine, L-Threonine) and polymers (Tween 40, Glycogen) than the soil microbes with clear tillage. It was considered that different treatments had the unique microbial community structure and peculiar carbon source utilization characteristics.

Functional group placement in protein binding sites: a comparison of GRID and MCSS

NASA Astrophysics Data System (ADS)

Bitetti-Putzer, Ryan; Joseph-McCarthy, Diane; Hogle, James M.; Karplus, Martin

2001-10-01

One approach to combinatorial ligand design begins by determining optimal locations (i.e., local potential energy minima) for functional groups in the binding site of a target macromolecule. MCSS and GRID are two methods, based on significantly different algorithms, which are used for this purpose. A comparison of the two methods for the same functional groups is reported. Calculations were performed for nonpolar and polar functional groups in the internal hydrophobic pocket of the poliovirus capsid protein, and on the binding surface of the src SH3 domain. The two approaches are shown to agree qualitatively; i.e., the global characteristics of the functional group maps generated by MCSS and GRID are similar. However, there are significant differences in the relative interaction energies of the two sets of minima, a consequence of the different functional form used to evaluate polar interactions (electrostatics and hydrogen bonding) in the two methods. The single sphere representation used by GRID affords only positional information, supplemented by the identification of hydrogen bonding interactions. By contrast, the multi-atom representation of most MCSS groups yields in both positional and orientational information. The two methods are most similar for small functional groups, while for larger functional groups MCSS yields results consistent with GRID but superior in detail. These results are in accord with the somewhat different purposes for which the two methods were developed. GRID has been used mainly to introduce functionalities at specific positions in lead compounds, in which case the orientation is predetermined by the structure of the latter. The orientational information provided by MCSS is important for its use in the de novo design of large, multi-functional ligands, as well as for improving lead compounds.

Genetic Diversity of Small Eukaryotes in Lakes Differing by Their Trophic Status

PubMed Central

Lefranc, Marie; Thénot, Aurélie; Lepère, Cécile; Debroas, Didier

2005-01-01

Small eukaryotes, cells with a diameter of less than 5 μm, are fundamental components of lacustrine planktonic systems. In this study, small-eukaryote diversity was determined by sequencing cloned 18S rRNA genes in three libraries from lakes of differing trophic status in the Massif Central, France: the oligotrophic Lake Godivelle, the oligomesotrophic Lake Pavin, and the eutrophic Lake Aydat. This analysis shows that the least diversified library was in the eutrophic lake (12 operational taxonomic units [OTUs]) and the most diversified was in the oligomesotrophic lake (26 OTUs). Certain groups were present in at least two ecosystems, while the others were specific to one lake on the sampling date. Cryptophyta, Chrysophyceae, and the strictly heterotrophic eukaryotes, Ciliophora and fungi, were identified in the three libraries. Among the small eukaryotes found only in two lakes, Choanoflagellida and environmental sequences (LKM11) were not detected in the eutrophic system whereas Cercozoa were confined to the oligomesotrophic and eutrophic lakes. Three OTUs, linked to the Perkinsozoa, were detected only in the Aydat library, where they represented 60% of the clones of the library. Chlorophyta and Haptophyta lineages were represented by a single clone and were present only in Godivelle and Pavin, respectively. Of the 127 clones studied, classical pigmented organisms (autotrophs and mixotrophs) represented only a low proportion regardless of the library's origin. This study shows that the small-eukaryote community composition may differ as a function of trophic status; certain lineages could be detected only in a single ecosystem. PMID:16204507

A novel spatial-temporal detection method of dim infrared moving small target

NASA Astrophysics Data System (ADS)

Chen, Zhong; Deng, Tao; Gao, Lei; Zhou, Heng; Luo, Song

2014-09-01

Moving small target detection under complex background in infrared image sequence is one of the major challenges of modern military in Early Warning Systems (EWS) and the use of Long-Range Strike (LRS). However, because of the low SNR and undulating background, the infrared moving small target detection is a difficult problem in a long time. To solve this problem, a novel spatial-temporal detection method based on bi-dimensional empirical mode decomposition (EMD) and time-domain difference is proposed in this paper. This method is downright self-data decomposition and do not rely on any transition kernel function, so it has a strong adaptive capacity. Firstly, we generalized the 1D EMD algorithm to the 2D case. In this process, the project has solved serial issues in 2D EMD, such as large amount of data operations, define and identify extrema in 2D case, and two-dimensional signal boundary corrosion. The EMD algorithm studied in this project can be well adapted to the automatic detection of small targets under low SNR and complex background. Secondly, considering the characteristics of moving target, we proposed an improved filtering method based on three-frame difference on basis of the original difference filtering in time-domain, which greatly improves the ability of anti-jamming algorithm. Finally, we proposed a new time-space fusion method based on a combined processing of 2D EMD and improved time-domain differential filtering. And, experimental results show that this method works well in infrared small moving target detection under low SNR and complex background.

[Analysis of the Characteristics of Infantile Small World Neural Network Node Properties Correlated with the Influencing Factors].

PubMed

Qu, Haibo; Lu, Su; Zhang, Wenjing; Xiao, Yuan; Ning, Gang; Sun, Huaiqiang

2016-10-01

We applied resting-state functional magnetic resonance imaging(rfMRI)combined with graph theory to analyze 90 regions of the infantile small world neural network of the whole brain.We tried to get the following two points clear:1 whether the parameters of the node property of the infantile small world neural network are correlated with the level of infantile intelligence development;2 whether the parameters of the infantile small world neural network are correlated with the children’s baseline parameters,i.e.,the demographic parameters such as gender,age,parents’ education level,etc.Twelve cases of healthy infants were included in the investigation(9males and 3females with the average age of 33.42±8.42 months.)We then evaluated the level of infantile intelligence of all the cases and graded by Gesell Development Scale Test.We used a Siemens 3.0T Trio imaging system to perform resting-state(rs)EPI scans,and collected the BOLD functional Magnetic Resonance Imaging(fMRI)data.We performed the data processing with Statistical Parametric Mapping 5(SPM5)based on Matlab environment.Furthermore,we got the attributes of the whole brain small world and node attributes of 90 encephalic regions of templates of Anatomatic Automatic Labeling(ALL).At last,we carried out correlation study between the above-mentioned attitudes,intelligence scale parameters and demographic data.The results showed that many node attributes of small world neural network were closely correlated with intelligence scale parameters.Betweeness was mainly centered in thalamus,superior frontal gyrus,and occipital lobe(negative correlation).The r value of superior occipital gyrus associated with the individual and social intelligent scale was-0.729(P=0.007);degree was mainly centered in amygdaloid nucleus,superior frontal gyrus,and inferior parietal gyrus(positive correlation).The r value of inferior parietal gyrus associated with the gross motor intelligent scale was 0.725(P=0.008);efficiency was mainly centered in inferior frontal gyrus,inferior parietal gyrus,and insular lobe(positive correlation).The r value of inferior parietal gyrus associated with the language intelligent scale was 0.738(P=0.006);Anoda cluster coefficient(anodalCp)was centered in frontal lobe,inferior parietal gyrus,and paracentral lobule(positive correlation);Node shortest path length(nlp)was centered in frontal lobe,inferior parietal gyrus,and insular lobe.The distribution of the encephalic regions in the left and right brain was different.However,no statistical significance was found between the correlation of monolithic attributes of small world and intelligence scale.The encephalic regions,in which node attributes of small world were related to other demographic indices,were mainly centered in temporal lobe,cuneus,cingulated gyrus,angular gyrus,and paracentral lobule areas.Most of them belong to the default mode network(DMN).The node attributes of small world neural network are widely related to infantile intelligence level,moreover the distribution is characteristic in different encephalic regions.The distribution of dominant encephalic is in accordance the related functions.The existing correlations reflect the ever changing small world nervous network during infantile development.

Identification of an ionotropic glutamate receptor AMPA1/GRIA1 polymorphism in crossbred beef cows differing in fertility

USDA-ARS?s Scientific Manuscript database

A proposed functional polymorphism in the ionotropic glutamate receptor AMPA1 (GRIA1) has been reported to influence antral follicle numbers and fertility in cows. Repeat Breeder cows that fail to produce a calf in multiple seasons have been reported to have reduced numbers of small (1-3 mm) antral ...

Synthesis of a large communications aperture using small antennas

NASA Technical Reports Server (NTRS)

Resch, George M.; Cwik, T. W.; Jamnejad, V.; Logan, R. T.; Miller, R. B.; Rogstad, Dave H.

1994-01-01

In this report we compare the cost of an array of small antennas to that of a single large antenna assuming both the array and single large antenna have equal performance and availability. The single large antenna is taken to be one of the 70-m antennas of the Deep Space Network. The cost of the array is estimated as a function of the array element diameter for three different values of system noise temperature corresponding to three different packaging schemes for the first amplifier. Array elements are taken to be fully steerable paraboloids and their cost estimates were obtained from commercial vendors. Array loss mechanisms and calibration problems are discussed. For array elements in the range 3 - 35 m there is no minimum in the cost versus diameter curve for the three system temperatures that were studied.

Thermodynamics of Small Alkali Metal Halide Cluster Ions: Comparison of Classical Molecular Simulations with Experiment and Quantum Chemistry

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

Vlcek, Lukas; Uhlik, Filip; Moucka, Filip

We evaluate the ability of selected classical molecular models to describe the thermodynamic and structural aspects of gas-phase hydration of alkali halide ions and the formation of small water clusters. To understand the effect of many-body interactions (polarization) and charge penetration effects on the accuracy of a force field, we perform Monte Carlo simulations with three rigid water models using different functional forms to account for these effects: (i) point charge non-polarizable SPC/E, (ii) Drude point charge polarizable SWM4- DP, and (iii) Drude Gaussian charge polarizable BK3. Model predictions are compared with experimental Gibbs free energies and enthalpies of ionmore » hydration, and with microscopic structural properties obtained from quantum DFT calculations. We find that all three models provide comparable predictions for pure water clusters and cation hydration, but differ significantly in their description of anion hydration. None of the investigated classical force fields can consistently and quantitatively reproduce the experimental gas phase hydration thermodynamics. The outcome of this study highlights the relation between the functional form that describes the effective intermolecular interactions and the accuracy of the resulting ion hydration properties.« less

Assessment of image quality in x-ray radiography imaging using a small plasma focus device

NASA Astrophysics Data System (ADS)

Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

2014-08-01

This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

Wetting of heterogeneous substrates. A classical density-functional-theory approach

NASA Astrophysics Data System (ADS)

Yatsyshin, Peter; Parry, Andrew O.; Rascón, Carlos; Duran-Olivencia, Miguel A.; Kalliadasis, Serafim

2017-11-01

Wetting is a nucleation of a third phase (liquid) on the interface between two different phases (solid and gas). In many experimentally accessible cases of wetting, the interplay between the substrate structure, and the fluid-fluid and fluid-substrate intermolecular interactions leads to the appearance of a whole ``zoo'' of exciting interface phase transitions, associated with the formation of nano-droplets/bubbles, and thin films. Practical applications of wetting at small scales are numerous and include the design of lab-on-a-chip devices and superhydrophobic surfaces. In this talk, we will use a fully microscopic approach to explore the phase space of a planar wall, decorated with patches of different hydrophobicity, and demonstrate the highly non-trivial behaviour of the liquid-gas interface near the substrate. We will present fluid density profiles, adsorption isotherms and wetting phase diagrams. Our analysis is based on a formulation of statistical mechanics, commonly known as classical density-functional theory. It provides a computationally-friendly and rigorous framework, suitable for probing small-scale physics of classical fluids and other soft-matter systems. EPSRC Grants No. EP/L027186,EP/K503733;ERC Advanced Grant No. 247031.

Functionalized Thick Film Impedance Sensors for Use in In Vitro Cell Culture.

PubMed

Bartsch, Heike; Baca, Martin; Fernekorn, Uta; Müller, Jens; Schober, Andreas; Witte, Hartmut

2018-04-05

Multi-electrode arrays find application in electrophysiological recordings. The quality of the captured signals depends on the interfacial contact between electrogenic cells and the electronic system. Therefore, it requires reliable low-impedance electrodes. Low-temperature cofired ceramic technology offers a suitable platform for rapid prototyping of biological reactors and can provide both stable fluid supply and integrated bio-hardware interfaces for recordings in electrogenic cell cultures. The 3D assembly of thick film gold electrodes in in vitro bio-reactors has been demonstrated for neuronal recordings. However, especially when dimensions become small, their performance varies strongly. This work investigates the influence of different coatings on thick film gold electrodes with regard to their influence on impedance behavior. PSS layer, titanium oxynitride and laminin coatings are deposited on LTCC gold electrodes using different 2D and 3D MEA chip designs. Their impedance characteristics are compared and discussed. Titanium oxynitride layers emerged as suitable functionalization. Small 86-µm-electrodes have a serial resistance R s of 32 kOhm and serial capacitance C s of 4.1 pF at 1 kHz. Thick film gold electrodes with such coatings are thus qualified for signal recording in 3-dimensional in vitro cell cultures.

Effects of Neuromuscular Training on Children and Young Adults with Down Syndrome: Systematic Review and Meta-Analysis.

PubMed

Sugimoto, Dai; Bowen, Samantha L; Meehan, William P; Stracciolini, Andrea

2016-08-01

To synthesize existing research evidence and examine effects of neuromuscular training on general strength, maximal strength, and functional mobility tasks in children and young adults with Down syndrome. PubMed and EBSCO were used as a data source. To attain the aim of this study, literature search was performed under following inclusion criteria: (1) included participants with Down syndrome, (2) implemented a neuromuscular training intervention and measured outcome variables of general strength, maximal strength, and functional mobility tasks, (3) had a group of participants whose mean ages were under 30 years old, (4) employed a prospective controlled design, and (5) used mean and standard deviations to express the outcome variables. Effect size was calculated from each study based on pre- and post-testing value differences in general strength, maximal strength, and functional mobility tasks between control and intervention groups. The effect size was further classified in to one of the following categories: small, moderate, and large effects. Seven studies met inclusion criteria. Analysis indicated large to moderate effects on general strength, moderate to small effects on maximal strength, and small effect on functional mobility tasks by neuromuscular training. Although there were limited studies, the results showed that neuromuscular training could be used as an effective intervention in children and young adults with Down syndrome. Synthesis of seven reviewed studies indicated that neuromuscular training could be beneficial to optimize general and maximal muscular strength development in children and young adults with Down syndrome. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statin treatment and functional outcome after ischemic stroke: case-control and meta-analysis.

PubMed

Biffi, Alessandro; Devan, William J; Anderson, Christopher D; Cortellini, Lynelle; Furie, Karen L; Rosand, Jonathan; Rost, Natalia S

2011-05-01

Multiple studies suggest that statin use before acute ischemic stroke is associated with improved functional outcome. However, available evidence is conflicting, and several published reports are limited by small sample sizes. We therefore investigated the effect of antecedent use of statins on stroke outcome by performing a meta-analysis of all results from published studies as well as our own unpublished data. We performed a systematic literature search and meta-analysis of studies investigating the association between prestroke statin use and clinical outcome and included additional data from 126 prestroke statin users and 767 nonusers enrolled at our institution. A total of 12 studies, comprising 2013 statin users and 9682 nonusers, was meta-analyzed using a random effects model. We also meta-analyzed results for individual Trial of ORG 10172 in Acute Stroke Treatment stroke subtypes to determine whether the effect of statin use differed across subtypes using the Breslow-Day test. Meta-analysis of all available data identified an association between prestroke statin use and improved functional outcome (OR, 1.62; 95% CI, 1.39 to 1.88), but we uncovered evidence of publication bias. The effect of statin use on functional outcome was found to be larger for small vessel strokes compared with other subtypes (Breslow-Day P=0.008). Antecedent use of statins is associated with improved outcome in patients with acute ischemic stroke. This association appears to be stronger in patients with small vessel stroke subtype. However, evidence of publication bias in the existing literature suggests these findings should be interpreted with caution.

Statin Treatment and Functional Outcome after Ischemic Stroke: Case-control and Meta-analysis

PubMed Central

Biffi, A; Devan, WJ; Anderson, CD; Cortellini, L; Furie, KL; Rosand, J; Rost, NS

2011-01-01

Background and Purpose Multiple studies suggest that statin use prior to acute ischemic stroke (AIS) is associated with improved functional outcome. However, available evidence is conflicting, and several published reports are limited by small sample sizes. We therefore investigated the effect of antecedent use of statins on stroke outcome by performing a meta-analysis of all results from published studies as well as our own unpublished data. Methods We performed a systematic literature search and meta-analysis of studies investigating the association between pre-stroke statin use and clinical outcome, and included additional data from 126 pre-stroke statin users and 767 non-users enrolled at our Institution. A total of 12 studies, comprising 2013 statin users and 9682 non- users were meta-analyzed using a random effects model. We also meta-analyzed results for individual TOAST stroke subtypes to determine whether the effect of statin use differed across subtypes, using the Breslow-Day (BD) test. Results Meta-analysis of all available data identified an association between pre-stroke statin use and improved functional outcome (Odds Ratio = 1.62, 95% Confidence Interval: 1.39 -1.88), but we uncovered evidence of publication bias. The effect of statin use on functional outcome was found to be larger for small vessel strokes compared to other subtypes (BD p = 0.008). Conclusions Antecedent use of statins is associated with improved outcome in AIS patients. This association appears to be stronger in patients with small vessel stroke subtype. However, evidence of publication bias in the existing literature suggests these findings should be interpreted with caution. PMID:21415396

Biases in the Experimental Annotations of Protein Function and Their Effect on Our Understanding of Protein Function Space

PubMed Central

Schnoes, Alexandra M.; Ream, David C.; Thorman, Alexander W.; Babbitt, Patricia C.; Friedberg, Iddo

2013-01-01

The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here, we investigate just how prevalent is the “few articles - many proteins” phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments. PMID:23737737

Broadband light funneling in ultrasubwavelength channels having periodic connected unfilled apertures

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

Subramania, Ganapathi Subramanian; Brener, Igal; Foteinopoulou, Stavroula

2017-08-01

A structure for broadband light funneling comprises a two-dimensional periodic array of connected ultrasubwavelength apertures, each aperture comprising a large sub-aperture that aids in the coupling of the incoming incident light and a small sub-aperture that funnels a significant fraction of the incident light power. The structure possesses all the capabilities of prior extraordinary optical transmission platforms, yet operates nonresonantly on a distinctly different mechanism. The structure demonstrates efficient ultrabroadband funneling of optical power confined in an area as small as .about.(.lamda./500).sup.2, where optical fields are enhanced, thus exhibiting functional possibilities beyond resonant platforms.

Fluorescent Phthalocyanine Assembly Distinguishes Chiral Isomers of Different Types of Amino Acids and Sugars.

PubMed

Jiang, Yuying; Liu, Chenxi; Wang, Xiqian; Wang, Tianyu; Jiang, Jianzhuang

2017-07-25

The functions of some natural supramolecular architectures, such as ribosomes, are dependent on the recognition of different types of chiral biomolecules. However, the recognition of different types of chiral molecules (multiobject chiral recognition), such as amino acids and sugars, by independent and identically artificial supramolecular assembly, was rarely achieved. In this article, simple amphiphilic achiral phthalocyanine was found to form supramolecular chiral assemblies with charged water-soluble polymers upon host-guest interactions at the air/water interface. Among these systems, one identical phthalocyanine/poly(l-lysine) assembly not only can distinguish enantiomers of different amino acids but also can recognize several epimers of monose. The chiral recognitions were achieved by comparing either the steady-state fluorescence intensity or fluorescence quenching rate of phthalocyanine/poly(l-lysine) assemblies, before and after interaction with different small chiral molecules. It was demonstrated that the interactions between poly(l-lysine) and different small chiral molecules could change the aggregation of phthalocyanines. And the sensitivity of fluorescence and the excellent multiobject chiral recognition properties of the phthalocyanine/poly(l-lysine) assembly are dependent on the subtle molecular packing mode and the cooperation of different noncovalent interactions.

Association Between Montreal Cognitive Assessment Scores and Measures of Functional Mobility in Lower Extremity Amputees After Inpatient Rehabilitation.

PubMed

Frengopoulos, Courtney; Burley, Joshua; Viana, Ricardo; Payne, Michael W; Hunter, Susan W

2017-03-01

To determine whether scores on a cognitive measure are associated with walking endurance and functional mobility of individuals with transfemoral or transtibial amputations at discharge from inpatient prosthetic rehabilitation. Retrospective cohort study. Rehabilitation hospital. Consecutive admissions (N=176; mean age ± SD, 64.27±13.23y) with transfemoral or transtibial amputation that had data at admission and discharge from an inpatient prosthetic rehabilitation program. Not applicable. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). The L Test and the 2-minute walk test (2MWT) were used to estimate functional mobility and walking endurance. The mean ± SD MoCA score was 24.05±4.09 (range, 6-30), and 56.3% of patients had scores <26. MoCA scores had a small positive correlation with the 2MWT (r=.29, P<.01), and a small negative correlation to the L Test (r=-.24, P<.01). In multivariable linear regression, compared with people with the highest MoCA score quartile, there was no difference on the 2MWT, but people in the lowest 2 quartiles took longer to complete the L Test. Cognitive impairment was very prevalent. The association between MoCA and functional mobility was statistically significant. These results highlight the potential for differences on complex motor tasks for individuals with cognitive impairment but does not indicate a need to exclude them from rehabilitation on the basis of cognitive impairment alone. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Neuroanatomical details of the lateral neurons of Drosophila melanogaster support their functional role in the circadian system

PubMed Central

Schubert, Frank K.; Hagedorn, Nicolas; Yoshii, Taishi; Helfrich‐Förster, Charlotte

2018-01-01

Abstract Drosophila melanogaster is a long‐standing model organism in the circadian clock research. A major advantage is the relative small number of about 150 neurons, which built the circadian clock in Drosophila. In our recent work, we focused on the neuroanatomical properties of the lateral neurons of the clock network. By applying the multicolor‐labeling technique Flybow we were able to identify the anatomical similarity of the previously described E2 subunit of the evening oscillator of the clock, which is built by the 5th small ventrolateral neuron (5th s‐LNv) and one ITP positive dorsolateral neuron (LNd). These two clock neurons share the same spatial and functional properties. We found both neurons innervating the same brain areas with similar pre‐ and postsynaptic sites in the brain. Here the anatomical findings support their shared function as a main evening oscillator in the clock network like also found in previous studies. A second quite surprising finding addresses the large lateral ventral PDF‐neurons (l‐LNvs). We could show that the four hardly distinguishable l‐LNvs consist of two subgroups with different innervation patterns. While three of the neurons reflect the well‐known branching pattern reproduced by PDF immunohistochemistry, one neuron per brain hemisphere has a distinguished innervation profile and is restricted only to the proximal part of the medulla‐surface. We named this neuron “extra” l‐LNv (l‐LNvx). We suggest the anatomical findings reflect different functional properties of the two l‐LNv subgroups. PMID:29424420

Assessment of Environmental and Hereditary Influence on Development of Pituitary Tumors Using Dermatoglyphic Traits and Their Potential as Screening Markers.

PubMed

Gradiser, Marina; Matovinovic Osvatic, Martina; Dilber, Dario; Bilic-Curcic, Ines

2016-03-17

The aim of this study was to assess environmental and hereditary influence on development of pituitary tumors using dermatoglyphic traits. The study was performed on 126 patients of both genders with pituitary tumors (60 non-functional and 66 functional pituitary tumor patients) in comparison to the control group of 400 phenotypically healthy individuals. Statistical analysis of quantitative and qualitative traits of digito-palmar dermatoglyphics was performed, and hormonal status was determined according to the standard protocols. Although we did not find markers that could specifically distinguish functional from non-functional tumors, we have found markers predisposing to the development of tumors in general (a small number of ridges between triradius of both hands, a smaller number of ridges between the triradius of c-d rc R), those for endocrine dysfunction (increased number of arches and reduced number of whorls, difference of pattern distribution in the I3 and I4 interdigital space), and some that could potentially be attributed to patients suffering from pituitary tumors (small number of ridges for variables FRR 5, smaller number of ridges in the FRL 4 of both hands and difference of pattern distribution at thenar of I1 and I2 interdigital space). The usage of dermatoglyphic traits as markers of predisposition of pituitary tumor development could facilitate the earlier detection of patients in addition to standard methods, and possibly earlier treatment and higher survival rate. Finally, our results are consistent with the hypothesis about multifactorial nature of pituitary tumor etiology comprised of both gene instability and environmental factors.

Assessment of Environmental and Hereditary Influence on Development of Pituitary Tumors Using Dermatoglyphic Traits and Their Potential as Screening Markers

PubMed Central

Gradiser, Marina; Matovinovic Osvatic, Martina; Dilber, Dario; Bilic-Curcic, Ines

2016-01-01

The aim of this study was to assess environmental and hereditary influence on development of pituitary tumors using dermatoglyphic traits. The study was performed on 126 patients of both genders with pituitary tumors (60 non-functional and 66 functional pituitary tumor patients) in comparison to the control group of 400 phenotypically healthy individuals. Statistical analysis of quantitative and qualitative traits of digito-palmar dermatoglyphics was performed, and hormonal status was determined according to the standard protocols. Although we did not find markers that could specifically distinguish functional from non-functional tumors, we have found markers predisposing to the development of tumors in general (a small number of ridges between triradius of both hands, a smaller number of ridges between the triradius of c–d rc R), those for endocrine dysfunction (increased number of arches and reduced number of whorls, difference of pattern distribution in the I3 and I4 interdigital space), and some that could potentially be attributed to patients suffering from pituitary tumors (small number of ridges for variables FRR 5, smaller number of ridges in the FRL 4 of both hands and difference of pattern distribution at thenar of I1 and I2 interdigital space). The usage of dermatoglyphic traits as markers of predisposition of pituitary tumor development could facilitate the earlier detection of patients in addition to standard methods, and possibly earlier treatment and higher survival rate. Finally, our results are consistent with the hypothesis about multifactorial nature of pituitary tumor etiology comprised of both gene instability and environmental factors. PMID:26999178

A RRKM study and a DFT assessment on gas-phase fragmentation of formamide-M(2+) (M = Ca, Sr).

PubMed

Martín-Sómer, Ana; Gaigeot, Marie-Pierre; Yáñez, Manuel; Spezia, Riccardo

2014-07-28

A kinetic study of the unimolecular reactivity of formamide-M(2+) (M = Ca, Sr) systems was carried out by means of RRKM statistical theory using high-level DFT. The results predict M(2+), [M(NH2)](+) and [HCO](+) as the main products, together with an intermediate that could eventually evolve to produce [M(NH3)](2+) and CO, for high values of internal energy. In this framework, we also evaluated the influence of the external rotational energy on the reaction rate constants. In order to find a method to perform reliable electronic structure calculations for formamide-M(2+) (M = Ca, Sr) at a relatively low computational cost, an assessment of different methods was performed. In the first assessment twenty-one functionals, belonging to different DFT categories, and an MP2 wave function method using a small basis set were evaluated. CCSD(T)/cc-pWCVTZ single point calculations were used as reference. A second assessment has been performed on geometries and energies. We found BLYP/6-31G(d) and G96LYP/6-31+G(d,p) as the best performing methods, for formamide-Ca(2+) and formamide-Sr(2+), respectively. Furthermore, a detailed assessment was done on RRKM reactivity and G96LYP/6-31G(d) provided results in agreement with higher level calculations. The combination of geometrical, energetics and kinetics (RRKM) criteria to evaluate DFT functionals is rather unusual and provides an original assessment procedure. Overall, we suggest using G96LYP as the best performing functional with a small basis set for both systems.

Legume small GTPases and their role in the establishment of symbiotic associations with Rhizobium spp

PubMed Central

Memon, Abdul R

2009-01-01

Small GTP-binding genes act as molecular switches regulating myriad of cellular processes including vesicle-mediated intracellular trafficking, signal transduction, cytoskeletal reorganization and cell division in plants and animals. Even though these genes are well conserved both functionally and sequentially across whole Eukaryotae, occasional lineage-specific diversification in some plant species in terms of both functional and expressional characteristics have been reported. Hence, comparative phyletic and correlative functional analyses of legume small GTPases homologs with the genes from other Metazoa and Embryophyta species would be very beneficial for gleaning out the small GTPases that could have specialized in legume-specific processes; e.g., nodulation. The completion of genome sequences of two model legumes, Medicago truncatula and Lotus japonicus will significantly improve our knowledge about mechanism of biological processes taking place in legume-rhizobia symbiotic associations. Besides, the need for molecular switches coordinating busy cargo-trafficking between symbiosis partners would suggest a possible subfunctionalization of small GTPases in Fabaceae for these functions. Therefore, more detailed investigation into the functional characteristics of legume small GTPases would be helpful for the illumination of the events initialized with the perception of bacteria by host, followed by the formation of infection thread and the engulfment of rhizobial bacteria, and end with the senescence of nitrogen-fixing organelles, nodules. In summary, a more thorough functional and evolutionary characterization of small GTPases across the main lineages of Embryophyta is significant for better comprehension of evolutionary history of Plantae, that is because, these genes are associated with multitude of vital biological processes including organogenesis. PMID:19794839

Cyclic and Linear Monoterpenes in Phospholipid Membranes: Phase Behavior, Bilayer Structure, and Molecular Dynamics.

PubMed

Pham, Quoc Dat; Topgaard, Daniel; Sparr, Emma

2015-10-13

Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including antimicrobial activity and membrane penetration enhancement. The interaction between the monoterpenes and lipid bilayers is considered important to the understanding of the biological functions of monoterpenes. In this study, we investigated the effect of cyclic and linear monoterpenes on the structure and dynamics of lipids in model membranes. We have studied the ternary system 1,2-dimyristoyl-sn-glycero-3-phosphocholine-monoterpene-water as a model with a focus on dehydrated conditions. By combining complementary techniques, including differential scanning calorimetry, solid-state nuclear magnetic resonance, and small- and wide-angle X-ray scattering, bilayer structure, phase transitions, and lipid molecular dynamics were investigated at different water contents. Monoterpenes cause pronounced melting point depression and phase segregation in lipid bilayers, and the extent of these effects depends on the hydration conditions. The addition of a small amount of thymol to the fluid bilayer (volume fraction of 0.03 in the bilayer) leads to an increased order in the acyl chain close to the bilayer interface. The findings are discussed in relation to biological systems and lipid formulations.

A Small World of Neuronal Synchrony

PubMed Central

Yu, Shan; Huang, Debin; Singer, Wolf

2008-01-01

A small-world network has been suggested to be an efficient solution for achieving both modular and global processing—a property highly desirable for brain computations. Here, we investigated functional networks of cortical neurons using correlation analysis to identify functional connectivity. To reconstruct the interaction network, we applied the Ising model based on the principle of maximum entropy. This allowed us to assess the interactions by measuring pairwise correlations and to assess the strength of coupling from the degree of synchrony. Visual responses were recorded in visual cortex of anesthetized cats, simultaneously from up to 24 neurons. First, pairwise correlations captured most of the patterns in the population's activity and, therefore, provided a reliable basis for the reconstruction of the interaction networks. Second, and most importantly, the resulting networks had small-world properties; the average path lengths were as short as in simulated random networks, but the clustering coefficients were larger. Neurons differed considerably with respect to the number and strength of interactions, suggesting the existence of “hubs” in the network. Notably, there was no evidence for scale-free properties. These results suggest that cortical networks are optimized for the coexistence of local and global computations: feature detection and feature integration or binding. PMID:18400792

Parallel Quantum Circuit in a Tunnel Junction

NASA Astrophysics Data System (ADS)

Faizy Namarvar, Omid; Dridi, Ghassen; Joachim, Christian

2016-07-01

Spectral analysis of 1 and 2-states per line quantum bus are normally sufficient to determine the effective Vab(N) electronic coupling between the emitter and receiver states through the bus as a function of the number N of parallel lines. When Vab(N) is difficult to determine, an Heisenberg-Rabi time dependent quantum exchange process must be triggered through the bus to capture the secular oscillation frequency Ωab(N) between those states. Two different linear and regimes are demonstrated for Ωab(N) as a function of N. When the initial preparation is replaced by coupling of the quantum bus to semi-infinite electrodes, the resulting quantum transduction process is not faithfully following the Ωab(N) variations. Because of the electronic transparency normalisation to unity and of the low pass filter character of this transduction, large Ωab(N) cannot be captured by the tunnel junction. The broadly used concept of electrical contact between a metallic nanopad and a molecular device must be better described as a quantum transduction process. At small coupling and when N is small enough not to compensate for this small coupling, an N2 power law is preserved for Ωab(N) and for Vab(N).

Parallel Quantum Circuit in a Tunnel Junction

PubMed Central

Faizy Namarvar, Omid; Dridi, Ghassen; Joachim, Christian

2016-01-01

Spectral analysis of 1 and 2-states per line quantum bus are normally sufficient to determine the effective Vab(N) electronic coupling between the emitter and receiver states through the bus as a function of the number N of parallel lines. When Vab(N) is difficult to determine, an Heisenberg-Rabi time dependent quantum exchange process must be triggered through the bus to capture the secular oscillation frequency Ωab(N) between those states. Two different linear and regimes are demonstrated for Ωab(N) as a function of N. When the initial preparation is replaced by coupling of the quantum bus to semi-infinite electrodes, the resulting quantum transduction process is not faithfully following the Ωab(N) variations. Because of the electronic transparency normalisation to unity and of the low pass filter character of this transduction, large Ωab(N) cannot be captured by the tunnel junction. The broadly used concept of electrical contact between a metallic nanopad and a molecular device must be better described as a quantum transduction process. At small coupling and when N is small enough not to compensate for this small coupling, an N2 power law is preserved for Ωab(N) and for Vab(N). PMID:27453262

Parallel Quantum Circuit in a Tunnel Junction.

PubMed

Faizy Namarvar, Omid; Dridi, Ghassen; Joachim, Christian

2016-07-25

Spectral analysis of 1 and 2-states per line quantum bus are normally sufficient to determine the effective Vab(N) electronic coupling between the emitter and receiver states through the bus as a function of the number N of parallel lines. When Vab(N) is difficult to determine, an Heisenberg-Rabi time dependent quantum exchange process must be triggered through the bus to capture the secular oscillation frequency Ωab(N) between those states. Two different linear and regimes are demonstrated for Ωab(N) as a function of N. When the initial preparation is replaced by coupling of the quantum bus to semi-infinite electrodes, the resulting quantum transduction process is not faithfully following the Ωab(N) variations. Because of the electronic transparency normalisation to unity and of the low pass filter character of this transduction, large Ωab(N) cannot be captured by the tunnel junction. The broadly used concept of electrical contact between a metallic nanopad and a molecular device must be better described as a quantum transduction process. At small coupling and when N is small enough not to compensate for this small coupling, an N(2) power law is preserved for Ωab(N) and for Vab(N).

Small-Molecule Modulators of Methyl-Lysine Binding for the CBX7 Chromodomain

DOE PAGES

Ren, Chunyan; Morohashi, Keita; Plotnikov, Alexander N.; ...

2015-02-05

Chromobox homolog 7 (CBX7) plays an important role in gene transcription in a wide array of cellular processes, ranging from stem cell self-renewal and differentiation to tumor progression. CBX7 functions through its N-terminal chromodomain (ChD), which recognizes tri-methylated lysine 27 of histone 3 (H3K27me3), a conserved epigenetic mark that signifies gene transcriptional repression. Here in this study, we report discovery of small molecules that inhibit CBX7ChD binding to H3K27me3. Our crystal structures reveal the binding modes of these molecules that compete against H3K27me3 binding through interactions with key residues in the methyl-lysine binding pocket of CBX7ChD. We further show thatmore » a lead compound MS37452, derepresses transcription of Polycomb repressive complex target gene p16/CDKN2A by displacing CBX7 binding to the INK4A/ARF locus in prostate cancer cells. Ultimately, these small molecules have the potential to be developed into high-potency chemical modulators that target CBX7 functions in gene transcription in different disease pathways.« less

Cardiac Radionuclide Imaging in Rodents: A Review of Methods, Results, and Factors at Play

PubMed Central

Cicone, Francesco; Viertl, David; Quintela Pousa, Ana Maria; Denoël, Thibaut; Gnesin, Silvano; Scopinaro, Francesco; Vozenin, Marie-Catherine; Prior, John O.

2017-01-01

The interest around small-animal cardiac radionuclide imaging is growing as rodent models can be manipulated to allow the simulation of human diseases. In addition to new radiopharmaceuticals testing, often researchers apply well-established probes to animal models, to follow the evolution of the target disease. This reverse translation of standard radiopharmaceuticals to rodent models is complicated by technical shortcomings and by obvious differences between human and rodent cardiac physiology. In addition, radionuclide studies involving small animals are affected by several extrinsic variables, such as the choice of anesthetic. In this paper, we review the major cardiac features that can be studied with classical single-photon and positron-emitting radiopharmaceuticals, namely, cardiac function, perfusion and metabolism, as well as the results and pitfalls of small-animal radionuclide imaging techniques. In addition, we provide a concise guide to the understanding of the most frequently used anesthetics such as ketamine/xylazine, isoflurane, and pentobarbital. We address in particular their mechanisms of action and the potential effects on radionuclide imaging. Indeed, cardiac function, perfusion, and metabolism can all be significantly affected by varying anesthetics and animal handling conditions. PMID:28424774

Fluorination of vertically aligned carbon nanotubes: from CF4 plasma chemistry to surface functionalization.

PubMed

Struzzi, Claudia; Scardamaglia, Mattia; Colomer, Jean-François; Verdini, Alberto; Floreano, Luca; Snyders, Rony; Bittencourt, Carla

2017-01-01

The surface chemistry of plasma fluorinated vertically aligned carbon nanotubes (vCNT) is correlated to the CF 4 plasma chemical composition. The results obtained via FTIR and mass spectrometry are combined with the XPS and Raman analysis of the sample surface showing the dependence on different plasma parameters (power, time and distance from the plasma region) on the resulting fluorination. Photoemission and absorption spectroscopies are used to investigate the evolution of the electronic properties as a function of the fluorine content at the vCNT surface. The samples suffer a limited ageing effect, with a small loss of fluorine functionalities after two weeks in ambient conditions.

Fluorination of vertically aligned carbon nanotubes: from CF4 plasma chemistry to surface functionalization

PubMed Central

Scardamaglia, Mattia; Colomer, Jean-François; Verdini, Alberto; Floreano, Luca; Snyders, Rony; Bittencourt, Carla

2017-01-01

The surface chemistry of plasma fluorinated vertically aligned carbon nanotubes (vCNT) is correlated to the CF4 plasma chemical composition. The results obtained via FTIR and mass spectrometry are combined with the XPS and Raman analysis of the sample surface showing the dependence on different plasma parameters (power, time and distance from the plasma region) on the resulting fluorination. Photoemission and absorption spectroscopies are used to investigate the evolution of the electronic properties as a function of the fluorine content at the vCNT surface. The samples suffer a limited ageing effect, with a small loss of fluorine functionalities after two weeks in ambient conditions. PMID:28904833

Identification of candidate miRNAs and expression profile of yak oocytes before and after in vitro maturation by high-throughput sequencing.

PubMed

Xiong, X R; Lan, D L; Li, J; Zi, X D; Li, M Y

2016-12-01

Small RNA represents several unique non-coding RNA classes that have important function in a wide range of biological processes including development of germ cells and early embryonic, cell differentiation, cell proliferation and apoptosis in diverse organisms. However, little is known about their expression profiles and effects in yak oocytes maturation and early development. To investigate the function of small RNAs in the maturation process of yak oocyte and early development, two small RNA libraries of oocytes were constructed from germinal vesicle stage (GV) and maturation in vitro to metaphase II-arrested stage (M II) and then sequenced using small RNA high-throughput sequencing technology. A total of 9,742,592 and 12,168,523 clean reads were obtained from GV and M II oocytes, respectively. In total, 801 and 1,018 known miRNAs were acquired from GV and M II oocytes, and 75 miRNAs were found to be significantly differentially expressed: 47 miRNAs were upregulated and 28 miRNAs were downregulated in the M II oocytes compared to the GV stage. Among the upregulated miRNAs, miR-342 has the largest fold change (9.25-fold). Six highly expressed miRNAs (let-7i, miR-10b, miR-10c, miR-143, miR-146b and miR-148) were validated by real-time quantitative PCR (RT-qPCR) and consistent with the sequencing results. Furthermore, the expression patterns of two miRNAs and their potential targets were analysed in different developmental stages of oocytes and early embryos. This study provides the first miRNA profile in the mature process of yak oocyte. Seventy-five miRNAs are expressed differentially in GV and M II oocytes as well as among different development stages of early embryos, suggesting miRNAs involved in regulating oocyte maturation and early development of yak. These results showed specific miRNAs in yak oocytes had dynamic changes during meiosis. Further functional and mechanistic studies on the miRNAs during meiosis may beneficial to understanding the role of miRNAs on meiotic division. © 2016 Blackwell Verlag GmbH.

Effect of Jiangzhi tablet on gastrointestinal propulsive function in mice

NASA Astrophysics Data System (ADS)

Wang, Xiangrong; Geng, Xiuli; Zhao, Jingsheng; Fan, Lili; Zhang, Zhengchen

2018-04-01

This paper aims to study the effect of lipid-lowering tablets on gastric emptying and small intestinal propulsion in mice. Mice were randomly divided into control group, Digestant Pill group, Jiangzhi tablet group, middle dose and small dose, the mice gastric emptying phenolsulfonphthalein, gastric residual rate of phenol red indicator to evaluate the gastric emptying rate, residual rate of detection in mouse stomach; small intestine propulsion and selection of carbon ink as the experimental index. Effects were observed to promote the function of normal mice gastric emptying and intestine. The gastric emptying and small intestinal motor function of normal mice were all promoted by each administration group, and the effect was most obvious in small dose group. The effect of reducing blood lipid on gastrointestinal motility of mice ware obviously enhanced.

On the implementation of a class of upwind schemes for system of hyperbolic conservation laws

NASA Technical Reports Server (NTRS)

Yee, H. C.

1985-01-01

The relative computational effort among the spatially five point numerical flux functions of Harten, van Leer, and Osher and Chakravarthy is explored. These three methods typify the design principles most often used in constructing higher than first order upwind total variation diminishing (TVD) schemes. For the scalar case the difference in operation count between any two algorithms may be very small and yet the operation count for their system counterparts might be vastly different. The situation occurs even though one starts with two different yet equivalent representations for the scalar case.

Assessment of Radiation Embrittlement in Nuclear Reactor Pressure Vessel Surrogate Materials

NASA Astrophysics Data System (ADS)

Balzar, Davor

2010-10-01

The radiation-enhanced formation of small (1-2 nm) copper-rich precipitates (CRPs) is critical for the occurrence of embrittlement in nuclear-reactor pressure vessels. Small CRPs are coherent with the bcc matrix, which causes local matrix strain and interaction with the dislocation strain fields, thus impeding dislocation mobility. As CRPs grow, there is a critical size at which a phase transformation occurs, whereby the CRPs are no longer coherent with the matrix, and the strain is relieved. Diffraction-line-broadening analysis (DLBA) and small-angle neutron scattering (SANS) were used to characterize the precipitate formation in surrogate ferritic reactor-pressure vessel steels. The materials were aged for different times at elevated temperature to produce a series of specimens with different degrees of copper precipitation. SANS measurements showed that the precipitate size distribution broadens and shifts toward larger sizes as a function of ageing time. Mechanical hardness showed an increase with ageing time, followed by a decrease, which can be associated with the reduction in the number density as well as the loss of coherency at larger sizes. Inhomogeneous strain correlated with mechanical hardness.

Functional evolution and structural conservation in chimeric cytochromes p450: calibrating a structure-guided approach.

PubMed

Otey, Christopher R; Silberg, Jonathan J; Voigt, Christopher A; Endelman, Jeffrey B; Bandara, Geethani; Arnold, Frances H

2004-03-01

Recombination generates chimeric proteins whose ability to fold depends on minimizing structural perturbations that result when portions of the sequence are inherited from different parents. These chimeric sequences can display functional properties characteristic of the parents or acquire entirely new functions. Seventeen chimeras were generated from two CYP102 members of the functionally diverse cytochrome p450 family. Chimeras predicted to have limited structural disruption, as defined by the SCHEMA algorithm, displayed CO binding spectra characteristic of folded p450s. Even this small population exhibited significant functional diversity: chimeras displayed altered substrate specificities, a wide range in thermostabilities, up to a 40-fold increase in peroxidase activity, and ability to hydroxylate a substrate toward which neither parent heme domain shows detectable activity. These results suggest that SCHEMA-guided recombination can be used to generate diverse p450s for exploring function evolution within the p450 structural framework.

Parametric dependence of ocean wave-radar modulation transfer functions

NASA Technical Reports Server (NTRS)

Plant, W. J.; Keller, W. C.; Cross, A.

1983-01-01

Microwave techniques at X and L band were used to determine the dependence of ocean-wave radar modulation transfer functions (MTFs) on various environmental and radar parameters during the Marine Remote Sensing experiment of 1979 (MARSEN 79). These MIF are presented, as are coherence functions between the AM and FM parts of the backscattered microwave signal. It is shown that they both depend on several of these parameters. Besides confirming many of the properties of transfer functions reported by previous authors, indications are found that MTFs decrease with increasing angle between wave propagation and antenna-look directions but are essentially independent of small changes in air-sea temperature difference. However, coherence functions are much smaller when the antennas are pointed perpendicular to long waves. It is found that X band transfer functions measured with horizontally polarized microwave radiation have larger magnitudes than those obtained by using vertical polarization.

The Zernike expansion--an example of a merit function for 2D/3D registration based on orthogonal functions.

PubMed

Dong, Shuo; Kettenbach, Joachim; Hinterleitner, Isabella; Bergmann, Helmar; Birkfellner, Wolfgang

2008-01-01

Current merit functions for 2D/3D registration usually rely on comparing pixels or small regions of images using some sort of statistical measure. Problems connected to this paradigm the sometimes problematic behaviour of the method if noise or artefacts (for instance a guide wire) are present on the projective image. We present a merit function for 2D/3D registration which utilizes the decomposition of the X-ray and the DRR under comparison into orthogonal Zernike moments; the quality of the match is assessed by an iterative comparison of expansion coefficients. Results in a imaging study on a physical phantom show that--compared to standard cross--correlation the Zernike moment based merit function shows better robustness if histogram content in images under comparison is different, and that time expenses are comparable if the merit function is constructed out of a few significant moments only.

Implications of invasion by Juniperus virginiana on small mammals in the southern Great Plains

USGS Publications Warehouse

Horncastle, V.J.; Hellgren, E.C.; Mayer, P.M.; Ganguli, A.C.; Engle, David M.; Leslie, David M.

2005-01-01

Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examined effects of invasion by eastern red cedar on small mammals in 3 plant communities (tallgrass prairie, old field, and cross-timbers forest) in the cross-timbers ecoregion in Oklahoma. We sampled small mammals seasonally from May 2001 to August 2002 by using Sherman live traps and mark-recapture techniques on 3.24-ha, 450-trap grids in each plant community. We sampled vegetation in two hundred twenty-five 12 x 12-m cells within each grid. The structure of the small-mammal community differed among the 3 habitat types, with higher species diversity and richness in the tallgrass-prairie and old-field sites. Overall, the small-mammal community shifted along a gradient of increasing eastern red cedar. In the old-field and tallgrass-prairie plots, occurrence of grassland mammals decreased with increasing red cedar, whereas only 1 woodland mammal species increased. In the cross-timbers forest site, percent woody cover (<1 m in height), rather than cover of red cedar, was the most important factor affecting woodland mammal species. Examination of our data suggests that an increase in overstory cover from 0% to 30% red cedar can change a species-rich prairie community to a depauperate community dominated by 1 species, Peromyscus leucopus. Losses in species diversity and changes in mammal distribution paralleled those seen in avian communities invaded by eastern red cedar. Our results highlight ecological effects of invasion by eastern red cedar on diversity and function at multiple trophic levels. ?? 2005 American Society of Mammalogists.

Early detection of lung function decrements in children and adolescents with cystic fibrosis using new reference values.

PubMed

Zacharasiewicz, Angela; Renner, Sabine; Haderer, Flora; Weber, Michael; Dehlink, Eleonore; Szepfalusi, Zsolt; Frischer, Thomas

2017-08-01

Interpretation of lung function values in children with cystic fibrosis (CF) depends on the applied reference values. We hypothesize that differences between the new global lung function initiative (GLI) values and the formerly used Zapletal et al. values produce significantly different clinical results. We analyzed 3719 lung function measurements of 108 children and adolescents (n = 54 male; aged 6-18 years) with CF treated between September 1991 and July 2009. Data were analyzed in milliliters (ml) and % predicted (pred.) and interpreted using Zapletal and GLI reference values. Applying GLI compared to Zapletal resulted in significantly lower mean forced expiratory volume in 1s (FEV1)% pred. Zapletal 86.6% (SD 20.6), GLI 79.9% (SD 20.3) and 32% (n = 497/1543) were misclassified as normal when using Zapletal. Despite showing no overall differences in FEV1 and forced vital capacity (FVC) between concomitant Pseudomonas detection (PA+) in n = 938 and Pseudomonas negative (PA-) (n = 2781) using either reference PA+ resulted in lower FEV1 and FVC values with increasing age; however, measurement of small airway obstruction with forced expiratory flow at 75% of FVC (FEF75) values - available for Zapletal -showed significant differences. Reassurance regarding lung function when using old reference values may occur with potential clinical significance. Discrepancies in lung function interpretation underline the importance of using uniform and best available reference values.

Quantification of gap junction selectivity.

PubMed

Ek-Vitorín, Jose F; Burt, Janis M

2005-12-01

Gap junctions, which are essential for functional coordination and homeostasis within tissues, permit the direct intercellular exchange of small molecules. The abundance and diversity of this exchange depends on the number and selectivity of the comprising channels and on the transjunctional gradient for and chemical character of the permeant molecules. Limited knowledge of functionally significant permeants and poor detectability of those few that are known have made it difficult to define channel selectivity. Presented herein is a multifaceted approach to the quantification of gap junction selectivity that includes determination of the rate constant for intercellular diffusion of a fluorescent probe (k2-DYE) and junctional conductance (gj) for each junction studied, such that the selective permeability (k2-DYE/gj) for dyes with differing chemical characteristics or junctions with differing connexin (Cx) compositions (or treatment conditions) can be compared. In addition, selective permeability can be correlated using single-channel conductance when this parameter is also measured. Our measurement strategy is capable of detecting 1) rate constants and selective permeabilities that differ across three orders of magnitude and 2) acute changes in that rate constant. Using this strategy, we have shown that 1) the selective permeability of Cx43 junctions to a small cationic dye varied across two orders of magnitude, consistent with the hypothesis that the various channel configurations adopted by Cx43 display different selective permeabilities; and 2) the selective permeability of Cx37 vs. Cx43 junctions was consistently and significantly lower.

Leisure time physical activity and subsequent physical and mental health functioning among midlife Finnish, British and Japanese employees: a follow-up study in three occupational cohorts.

PubMed

Lahti, Jouni; Sabia, Séverine; Singh-Manoux, Archana; Kivimäki, Mika; Tatsuse, Takashi; Yamada, Masaaki; Sekine, Michikazu; Lallukka, Tea

2016-01-06

The aim of this study was to examine whether leisure time physical activity contributes to subsequent physical and mental health functioning among midlife employees. The associations were tested in three occupational cohorts from Finland, Britain and Japan. Cohort study. Finland, Britain and Japan. Prospective employee cohorts from the Finnish Helsinki Health Study (2000-2002 and 2007, n=5958), British Whitehall II study (1997-1999 and 2003-2004, n=4142) and Japanese Civil Servants Study (1998-1999 and 2003, n=1768) were used. Leisure time physical activity was classified into three groups: inactive, moderately active and vigorously active. Mean scores of physical and mental health functioning (SF-36) at follow-up were examined. Physical activity was associated with better subsequent physical health functioning in all three cohorts, however, with varying magnitude and some gender differences. Differences were the clearest among Finnish women (inactive: 46.0, vigorously active: 49.5) and men (inactive: 47.8, active vigorous: 51.1) and British women (inactive: 47.3, active vigorous: 50.4). In mental health functioning, the differences were generally smaller and not that clearly related to the intensity of physical activity. Emerging differences in health functioning were relatively small. Vigorous physical activity was associated with better subsequent physical health functioning in all three cohorts with varying magnitude. For mental health functioning, the intensity of physical activity was less important. Promoting leisure time physical activity may prove useful for the maintenance of health functioning among midlife employees. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Infrared small target enhancement: grey level mapping based on improved sigmoid transformation and saliency histogram

NASA Astrophysics Data System (ADS)

Wan, Minjie; Gu, Guohua; Qian, Weixian; Ren, Kan; Chen, Qian

2018-06-01

Infrared (IR) small target enhancement plays a significant role in modern infrared search and track (IRST) systems and is the basic technique of target detection and tracking. In this paper, a coarse-to-fine grey level mapping method using improved sigmoid transformation and saliency histogram is designed to enhance IR small targets under different backgrounds. For the stage of rough enhancement, the intensity histogram is modified via an improved sigmoid function so as to narrow the regular intensity range of background as much as possible. For the part of further enhancement, a linear transformation is accomplished based on a saliency histogram constructed by averaging the cumulative saliency values provided by a saliency map. Compared with other typical methods, the presented method can achieve both better visual performances and quantitative evaluations.

Large herbivores affect forest ecosystem functions by altering the structure of dung beetle communities

NASA Astrophysics Data System (ADS)

Iida, Taichi; Soga, Masashi; Koike, Shinsuke

2018-04-01

Dramatic increases in populations of large mammalian herbivores have become a major ecological issue, particularly in the northern hemisphere, due to their substantial impacts on both animal and plant communities through processes such as grazing, browsing, and trampling. However, little is known about the consequences of these population explosions on ecosystem functions. Here, we experimentally investigated how the population density of sika deer (Cervus nippon) in temperate deciduous forest areas in Japan affected the decomposition of mammal dung by dung beetles, which is a key process in forest ecosystems. We measured a range of environmental variables (e.g., vegetation cover, soil hardness) and the dung decomposition rate, measured as the amount of deer dung decomposed during one week, and sampled dung beetles at 16 study sites with three different deer densities (high/intermediate/low). We then used structural equation modeling to investigate the relationships between deer density, environmental variables, the biomass of dung beetles (classified into small or large species), and the dung decomposition rate. We found that the biomass of small species increased with increasing deer density, whereas that of large species was not related to deer density. Furthermore, the dung decomposition rate was positively related to the biomass of small species but unrelated to that of large species. Overall, our results showed that an increase in deer density affects the decomposition rate of mammal dung by changing the structure of dung beetle communities (i.e., increasing the number of small dung beetles). Such an understanding of how increases in large herbivore populations affect ecosystem functions is important for accurately evaluating the ecological consequences of their overabundance and ultimately managing their populations appropriately.

Model based systems engineering (MBSE) applied to Radio Aurora Explorer (RAX) CubeSat mission operational scenarios

NASA Astrophysics Data System (ADS)

Spangelo, S. C.; Cutler, J.; Anderson, L.; Fosse, E.; Cheng, L.; Yntema, R.; Bajaj, M.; Delp, C.; Cole, B.; Soremekum, G.; Kaslow, D.

Small satellites are more highly resource-constrained by mass, power, volume, delivery timelines, and financial cost relative to their larger counterparts. Small satellites are operationally challenging because subsystem functions are coupled and constrained by the limited available commodities (e.g. data, energy, and access times to ground resources). Furthermore, additional operational complexities arise because small satellite components are physically integrated, which may yield thermal or radio frequency interference. In this paper, we extend our initial Model Based Systems Engineering (MBSE) framework developed for a small satellite mission by demonstrating the ability to model different behaviors and scenarios. We integrate several simulation tools to execute SysML-based behavior models, including subsystem functions and internal states of the spacecraft. We demonstrate utility of this approach to drive the system analysis and design process. We demonstrate applicability of the simulation environment to capture realistic satellite operational scenarios, which include energy collection, the data acquisition, and downloading to ground stations. The integrated modeling environment enables users to extract feasibility, performance, and robustness metrics. This enables visualization of both the physical states (e.g. position, attitude) and functional states (e.g. operating points of various subsystems) of the satellite for representative mission scenarios. The modeling approach presented in this paper offers satellite designers and operators the opportunity to assess the feasibility of vehicle and network parameters, as well as the feasibility of operational schedules. This will enable future missions to benefit from using these models throughout the full design, test, and fly cycle. In particular, vehicle and network parameters and schedules can be verified prior to being implemented, during mission operations, and can also be updated in near real-time with oper- tional performance feedback.

Decreased functional connectivity in schizophrenia: The relationship between social functioning, social cognition and graph theoretical network measures.

PubMed

Erdeniz, Burak; Serin, Emin; İbadi, Yelda; Taş, Cumhur

2017-12-30

Schizophrenia is a complex disorder in which abnormalities in brain connectivity and social functioning play a central role. The aim of this study is to explore small-world network properties, and understand their relationship with social functioning and social cognition in the context of schizophrenia, by testing functional connectivity differences in network properties and its relation to clinical behavioral measures. Resting-state fMRI time series data were acquired from 23 patients diagnosed with schizophrenia and 23 healthy volunteers. The results revealed that patients with schizophrenia show significantly decreased connectivity between a range of brain regions, particularly involving connections among the right orbitofrontal cortex, bilateral putamen and left amygdala. Furthermore, topological properties of functional brain networks in patients with schizophrenia were characterized by reduced path length compared to healthy controls; however, no significant difference was found for clustering coefficient, local efficiency or global efficiency. Additionally, we found that nodal efficiency of the amygdala and the putamen were significantly correlated with the independence-performance subscale of social functioning scale (SFC), and Reading the Mind in the Eyes test; however, the correlations do not survive correction for multiple comparison. The current results help to clarify the relationship between social functioning deficits and topological brain measures in schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Diuretics as pathogenetic treatment for heart failure

PubMed Central

Guglin, Maya

2011-01-01

Increased intracardiac filling pressure or congestion causes symptoms and leads to hospital admissions in patients with heart failure, regardless of their systolic function. A history of hospital admission, in turn, predicts further hospitalizations and morbidity, and a higher number of hospitalizations determine higher mortality. Congestion is therefore the driving force of the natural history of heart failure. Congestion is the syndrome shared by heart failure with preserved and reduced systolic function. These two conditions have almost identical morbidity, mortality, and survival because the outcomes are driven by congestion. A small difference in favor of heart failure with preserved systolic function comes from decreased ejection fraction and left ventricular remodeling which is only present in heart failure with decreased systolic function. The magnitude of this difference reflects the contribution of decreased systolic function and ventricular remodeling to the progression of heart failure. The only treatment available for congestion is fluid removal via diuretics, ultrafiltration, or dialysis. It is the only treatment that works equally well for heart failure with reduced and preserved systolic function because it affects congestion, the main pathogenetic feature of the disease. Diuretics are pathogenetic therapy for heart failure. PMID:21403798

Approach to assess consequences of hypoxia disturbance events for benthic ecosystem functioning

NASA Astrophysics Data System (ADS)

Gogina, Mayya; Darr, Alexander; Zettler, Michael L.

2014-01-01

Our study challenges the functional approach for its usefulness in assessing the consequences of hypoxia disturbance events on macrofaunal communities in the south-western Baltic Sea. Time series for two decades of observations from two monitoring stations, one in the Fehmarnbelt (exposed to aperiodic hypoxia), and another in the Darss Rise (normoxic conditions) is used. Our results designate differences of functional structure of benthic fauna communities between sites based on biological traits that characterise species role in modifying the environment, behavioural strategies, morphology and life history, thus suggesting differences in functioning. Hypoxic years reveal sharp increase of the role of sedentary species, suspension filter feeders, epibenthic structures, globulose form, medium/large size of individuals, preponderance of species with long lifespan (caused for instance by remaining ocean quahog). The link of functional and species diversity to the stagnation periods is proposed for the Darss station that exhibit continuous changes and low temporal variability of traits distribution. Before the major inflow in 1993 the increased role of small size organisms, containing calcium carbonate, filter feeders and grazers, higher presence of semi-pelagic species is observed. The hypoxic events and water renewal processes impact the communities not only in respect to species composition but also functionally.

[Aberrant topological properties of whole-brain functional network in chronic right-sided sensorineural hearing loss: a resting-state functional MRI study].

PubMed

Zhang, Lingling; Liu, Bin; Xu, Yangwen; Yang, Ming; Feng, Yuan; Huang, Yaqing; Huan, Zhichun; Hou, Zhaorui

2015-02-03

To investigate the topological properties of the functional brain network in unilateral sensorineural hearing loss patients. In this study, we acquired resting-state BOLD- fMRI data from 19 right-sided SNHL patients and 31 healthy controls with normal hearing and constructed their whole brain functional networks. Two-sample two-tailed t-tests were performed to investigate group differences in topological parameters between the USNHL patients and the controls. Partial correlation analysis was conducted to determine the relationships between the network metrics and USNHL-related variables. Both USNHL patients and controls exhibited small-word architecture in their brain functional networks within the range 0. 1 - 0. 2 of sparsity. Compared to the controls, USNHL patients showed significant increase in characteristic path length and normalized characteristic path length, but significant decrease in global efficiency. Clustering coefficient, local efficiency and normalized clustering coefficient demonstrated no significant difference. Furthermore, USNHL patients exhibited no significant association between the altered network metrics and the duration of USNHL or the severity of hearing loss. Our results indicated the altered topological properties of whole brain functional networks in USNHL patients, which may help us to understand pathophysiologic mechanism of USNHL patients.

Characterization of intermittency in zooplankton behaviour in turbulence.

PubMed

Michalec, François-Gaël; Schmitt, François G; Souissi, Sami; Holzner, Markus

2015-10-01

We consider Lagrangian velocity differences of zooplankters swimming in still water and in turbulence. Using cumulants, we quantify the intermittency properties of their motion recorded using three-dimensional particle tracking velocimetry. Copepods swimming in still water display an intermittent behaviour characterized by a high probability of small velocity increments, and by stretched exponential tails. Low values arise from their steady cruising behaviour while heavy tails result from frequent relocation jumps. In turbulence, we show that at short time scales, the intermittency signature of active copepods clearly differs from that of the underlying flow, and reflects the frequent relocation jumps displayed by these small animals. Despite these differences, we show that copepods swimming in still and turbulent flow belong to the same intermittency class that can be modelled by a log-stable model with non-analytical cumulant generating function. Intermittency in swimming behaviour and relocation jumps may enable copepods to display oriented, collective motion under strong hydrodynamic conditions and thus, may contribute to the formation of zooplankton patches in energetic environments.

The FUN of identifying gene function in bacterial pathogens; insights from Salmonella functional genomics.

PubMed

Hammarlöf, Disa L; Canals, Rocío; Hinton, Jay C D

2013-10-01

The availability of thousands of genome sequences of bacterial pathogens poses a particular challenge because each genome contains hundreds of genes of unknown function (FUN). How can we easily discover which FUN genes encode important virulence factors? One solution is to combine two different functional genomic approaches. First, transcriptomics identifies bacterial FUN genes that show differential expression during the process of mammalian infection. Second, global mutagenesis identifies individual FUN genes that the pathogen requires to cause disease. The intersection of these datasets can reveal a small set of candidate genes most likely to encode novel virulence attributes. We demonstrate this approach with the Salmonella infection model, and propose that a similar strategy could be used for other bacterial pathogens. Copyright © 2013 Elsevier Ltd. All rights reserved.

The respiratory health and lung function of Anglo-American children in a smelter town

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

Dodge, R.

1983-02-01

Cooper smelters are large, usually isolated, sources of air pollution. Arizona has several such plants on the periphery of small communities. The smelters emit predominantly sulfur oxides and particulates, and the residents of these communities intermittently are exposed to high concentrations (24-h sulfur dioxide (SO2) . 250 to 500 micrograms/m3) of smelter smoke but little other pollution. This study compared the respiratory health of Anglo-American school children who lived in one smelter community with children living in another small community in Arizona that was free of smelter air pollution. The prevalence of cough, as determined by questionnaire, was 25.6% inmore » the smelter town children and 14.3% in the nonsmelter town children (p less than 0.05). Pulmonary function at the study onset was equal in the two groups. Over the course of the 4 yr of study, lung function growth (measured as actual forced expiratory volume in one second (FEV1) after 4 yr of study minus predicted FEV1) was also equal in the smelter town and nonsmelter town children. These results suggest that children in smelter communities have slightly more cough when compared with children living in other communities, but no differences in initial lung function or lung function at yearly testing over the period of the study.« less

Optimization of a Clinically Relevant Model of White Matter Stroke in Mice: Histological and Functional Evidences

PubMed Central

Ahmad, Abdullah S.; Satriotomo, Irawan; Fazal, Jawad A.; Nadeau, Stephen E.; Doré, Sylvain

2015-01-01

Background and Purpose White matter (WM) injury during stroke increases the risk of disability and gloomy prognosis of post-stroke rehabilitation. However, modeling of WM loss in rodents has proven to be challenging. Methods We report improved WM injury models in male C57BL/6 mice. Mice were given either endothelin-1 (ET-1) or L-N5-(1-iminoethyl)ornitine (L-NIO) into the periventricular white matter (PVWM), in the corpus callosum (CC), or in the posterior limb of internal capsule (PLIC). Anatomical and functional outcomes were quantified on day 7 post injection. Results Injection of ET-1 or L-NIO caused a small focal lesion in the injection site in the PVWM. No significant motor function deficits were observed in the PVWM lesion model. We next targeted the PLIC by using single or double injections of L-NIO and found that this strategy induced small focal infarction. Interestingly, injection of L-NIO in the PLIC also resulted in gliosis, and significant motor function deficits. Conclusions By employing different agents, doses, and locations, this study shows the feasibility of inducing brain WM injury accompanied with functional deficits in mice. Selective targeting of the injury location, behavioral testing, and the agents chosen to induce WM injury are all keys to successfully develop a mouse model and subsequent testing of therapeutic interventions against WM injury. PMID:27512724

Falling head ponded infiltration in the nonlinear limit

NASA Astrophysics Data System (ADS)

Triadis, D.

2014-12-01

The Green and Ampt infiltration solution represents only an extreme example of behavior within a larger class of very nonlinear, delta function diffusivity soils. The mathematical analysis of these soils is greatly simplified by the existence of a sharp wetting front below the soil surface. Solutions for more realistic delta function soil models have recently been presented for infiltration under surface saturation without ponding. After general formulation of the problem, solutions for a full suite of delta function soils are derived for ponded surface water depleted by infiltration. Exact expressions for the cumulative infiltration as a function of time, or the drainage time as a function of the initial ponded depth may take implicit or parametric forms, and are supplemented by simple asymptotic expressions valid for small times, and small and large initial ponded depths. As with surface saturation without ponding, the Green-Ampt model overestimates the effect of the soil hydraulic conductivity. At the opposing extreme, a low-conductivity model is identified that also takes a very simple mathematical form and appears to be more accurate than the Green-Ampt model for larger ponded depths. Between these two, the nonlinear limit of Gardner's soil is recommended as a physically valid first approximation. Relative discrepancies between different soil models are observed to reach a maximum for intermediate values of the dimensionless initial ponded depth, and in general are smaller than for surface saturation without ponding.

Identification and analysis of mutational hotspots in oncogenes and tumour suppressors.

PubMed

Baeissa, Hanadi; Benstead-Hume, Graeme; Richardson, Christopher J; Pearl, Frances M G

2017-03-28

The key to interpreting the contribution of a disease-associated mutation in the development and progression of cancer is an understanding of the consequences of that mutation both on the function of the affected protein and on the pathways in which that protein is involved. Protein domains encapsulate function and position-specific domain based analysis of mutations have been shown to help elucidate their phenotypes. In this paper we examine the domain biases in oncogenes and tumour suppressors, and find that their domain compositions substantially differ. Using data from over 30 different cancers from whole-exome sequencing cancer genomic projects we mapped over one million mutations to their respective Pfam domains to identify which domains are enriched in any of three different classes of mutation; missense, indels or truncations. Next, we identified the mutational hotspots within domain families by mapping small mutations to equivalent positions in multiple sequence alignments of protein domainsWe find that gain of function mutations from oncogenes and loss of function mutations from tumour suppressors are normally found in different domain families and when observed in the same domain families, hotspot mutations are located at different positions within the multiple sequence alignment of the domain. By considering hotspots in tumour suppressors and oncogenes independently, we find that there are different specific positions within domain families that are particularly suited to accommodate either a loss or a gain of function mutation. The position is also dependent on the class of mutation.We find rare mutations co-located with well-known functional mutation hotspots, in members of homologous domain superfamilies, and we detect novel mutation hotspots in domain families previously unconnected with cancer. The results of this analysis can be accessed through the MOKCa database (http://strubiol.icr.ac.uk/extra/MOKCa).

A size selective porous silicon grating-coupled Bloch surface and sub-surface wave biosensor.

PubMed

Rodriguez, Gilberto A; Ryckman, Judson D; Jiao, Yang; Weiss, Sharon M

2014-03-15

A porous silicon (PSi) grating-coupled Bloch surface and sub-surface wave (BSW/BSSW) biosensor is demonstrated to size selectively detect the presence of both large and small molecules. The BSW is used to sense large immobilized analytes at the surface of the structure while the BSSW that is confined inside but near the top of the structure is used to sensitively detect small molecules. Functionality of the BSW and BSSW modes is theoretically described by dispersion relations, field confinements, and simulated refractive index shifts within the structure. The theoretical results are experimentally verified by detecting two different small chemical molecules and one large 40 base DNA oligonucleotide. The PSi-BSW/BSSW structure is benchmarked against current porous silicon technology and is shown to have a 6-fold higher sensitivity in detecting large molecules and a 33% improvement in detecting small molecules. This is the first report of a grating-coupled BSW biosensor and the first report of a BSSW propagating mode. © 2013 Published by Elsevier B.V.

Detection of dual-band infrared small target based on joint dynamic sparse representation

NASA Astrophysics Data System (ADS)

Zhou, Jinwei; Li, Jicheng; Shi, Zhiguang; Lu, Xiaowei; Ren, Dongwei

2015-10-01

Infrared small target detection is a crucial and yet still is a difficult issue in aeronautic and astronautic applications. Sparse representation is an important mathematic tool and has been used extensively in image processing in recent years. Joint sparse representation is applied in dual-band infrared dim target detection in this paper. Firstly, according to the characters of dim targets in dual-band infrared images, 2-dimension Gaussian intensity model was used to construct target dictionary, then the dictionary was classified into different sub-classes according to different positions of Gaussian function's center point in image block; The fact that dual-band small targets detection can use the same dictionary and the sparsity doesn't lie in atom-level but in sub-class level was utilized, hence the detection of targets in dual-band infrared images was converted to be a joint dynamic sparse representation problem. And the dynamic active sets were used to describe the sparse constraint of coefficients. Two modified sparsity concentration index (SCI) criteria was proposed to evaluate whether targets exist in the images. In experiments, it shows that the proposed algorithm can achieve better detecting performance and dual-band detection is much more robust to noise compared with single-band detection. Moreover, the proposed method can be expanded to multi-spectrum small target detection.

Graph theoretical analysis of EEG functional connectivity during music perception.

PubMed

Wu, Junjie; Zhang, Junsong; Liu, Chu; Liu, Dongwei; Ding, Xiaojun; Zhou, Changle

2012-11-05

The present study evaluated the effect of music on large-scale structure of functional brain networks using graph theoretical concepts. While most studies on music perception used Western music as an acoustic stimulus, Guqin music, representative of Eastern music, was selected for this experiment to increase our knowledge of music perception. Electroencephalography (EEG) was recorded from non-musician volunteers in three conditions: Guqin music, noise and silence backgrounds. Phase coherence was calculated in the alpha band and between all pairs of EEG channels to construct correlation matrices. Each resulting matrix was converted into a weighted graph using a threshold, and two network measures: the clustering coefficient and characteristic path length were calculated. Music perception was found to display a higher level mean phase coherence. Over the whole range of thresholds, the clustering coefficient was larger while listening to music, whereas the path length was smaller. Networks in music background still had a shorter characteristic path length even after the correction for differences in mean synchronization level among background conditions. This topological change indicated a more optimal structure under music perception. Thus, prominent small-world properties are confirmed in functional brain networks. Furthermore, music perception shows an increase of functional connectivity and an enhancement of small-world network organizations. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of high-pressure homogenization on different matrices of food supplements.

PubMed

Martínez-Sánchez, Ascensión; Tarazona-Díaz, Martha Patricia; García-González, Antonio; Gómez, Perla A; Aguayo, Encarna

2016-12-01

There is a growing demand for food supplements containing high amounts of vitamins, phenolic compounds and mineral content that provide health benefits. Those functional compounds have different solubility properties, and the maintenance of their compounds and the guarantee of their homogenic properties need the application of novel technologies. The quality of different drinkable functional foods after thermal processing (0.1 MPa) or high-pressure homogenization under two different conditions (80 MPa, 33 ℃ and 120 MPa, 43 ℃) was studied. Physicochemical characteristics and sensory qualities were evaluated throughout the six months of accelerated storage at 40 ℃ and 75% relative humidity (RH). Aroma and color were better maintained in high-pressure homogenization-treated samples than the thermally treated ones, which contributed significantly to extending their shelf life. The small particle size obtained after high-pressure homogenization treatments caused differences in turbidity and viscosity with respect to heat-treated samples. The use of high-pressure homogenization, more specifically, 120 MPa, provided active ingredient homogeneity to ensure uniform content in functional food supplements. Although the effect of high-pressure homogenization can be affected by the food matrix, high-pressure homogenization can be implemented as an alternative to conventional heat treatments in a commercial setting within the functional food supplement or pharmaceutical industry. © The Author(s) 2016.

[Different patterns of follicular development and luteal function].

PubMed

Gu, L; Zhang, L; Gu, F

1995-09-01

To study the relationship between luteal function and different patterns of follicular development. Different patterns of follicular development as observed under transvaginal B-ultrasound in 85 infertile patients included: (1) Ovulation from normal follicle (ONF). (2) Ovulation from two follicles at the same cycle (O2F). (3) Ovulation from small follicle (OSF). (4) Ovulation from polycystic ovaries (PCO). (5) Luteinized unruptured follicle syndrome (LUFS). (6) Anovulation with follicular atresia. The luteal function of the first 5 types was evaluated by serum and peritoneal fluid estrogen, progesterone levels, endometrial histology, estradiol receptor (ER) and progesterone receptor (PR) analyaes, and the length of luteal phase. The incidence of luteal phase deficiency (LPD): short luteal phase was 10.42%, retardation of endometrial development was 4.17% in ONF, no LPD in O2F, 21.42% in OSF, 2/3 in PCO, 3/6 in LUFS, respectively. The incidence of LPD was 14.58% in ONF, 56.52% in abnormal follicular development groups (OSF, O2F and LUFS) (P < 0.005). It was found that the retardation of endometrial development was associated either with lowered serum P level or normal serum P but lowered ER and PR concentrations. The latter condition was recognized as "pseudocorpus luteum deficiency". The different patterns of follicular development may exert a great influence over luteal function through the different production of steroid hormones and their receptors.

Abbreviated neuropsychological assessment in schizophrenia

PubMed Central

Harvey, Philip D.; Keefe, Richard S. E.; Patterson, Thomas L.; Heaton, Robert K.; Bowie, Christopher R.

2008-01-01

The aim of this study was to identify the best subset of neuropsychological tests for prediction of several different aspects of functioning in a large (n = 236) sample of older people with schizophrenia. While the validity of abbreviated assessment methods has been examined before, there has never been a comparative study of the prediction of different elements of cognitive impairment, real-world outcomes, and performance-based measures of functional capacity. Scores on 10 different tests from a neuropsychological assessment battery were used to predict global neuropsychological (NP) performance (indexed with averaged scores or calculated general deficit scores), performance-based indices of everyday-living skills and social competence, and case-manager ratings of real-world functioning. Forward entry stepwise regression analyses were used to identify the best predictors for each of the outcomes measures. Then, the analyses were adjusted for estimated premorbid IQ, which reduced the magnitude, but not the structure, of the correlations. Substantial amounts (over 70%) of the variance in overall NP performance were accounted for by a limited number of NP tests. Considerable variance in measures of functional capacity was also accounted for by a limited number of tests. Different tests constituted the best predictor set for each outcome measure. A substantial proportion of the variance in several different NP and functional outcomes can be accounted for by a small number of NP tests that can be completed in a few minutes, although there is considerable unexplained variance. However, the abbreviated assessments that best predict different outcomes vary across outcomes. Future studies should determine whether responses to pharmacological and remediation treatments can be captured with brief assessments as well. PMID:18720182

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, Dennis; de Bruijn, Karin; Bouwer, Laurens; de Moel, Hans

2015-04-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage models can lead to large uncertainties in flood damage estimates. This explanation is used to quantify this uncertainty with a Monte Carlo Analysis. This Monte Carlo analysis uses a damage function library with 272 functions from 7 different flood damage models. This results in uncertainties in the order of magnitude of a factor 2 to 5. This uncertainty is typically larger for small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Uncertainty in flood damage estimates and its potential effect on investment decisions

NASA Astrophysics Data System (ADS)

Wagenaar, D. J.; de Bruijn, K. M.; Bouwer, L. M.; De Moel, H.

2015-01-01

This paper addresses the large differences that are found between damage estimates of different flood damage models. It explains how implicit assumptions in flood damage models can lead to large uncertainties in flood damage estimates. This explanation is used to quantify this uncertainty with a Monte Carlo Analysis. As input the Monte Carlo analysis uses a damage function library with 272 functions from 7 different flood damage models. This results in uncertainties in the order of magnitude of a factor 2 to 5. The resulting uncertainty is typically larger for small water depths and for smaller flood events. The implications of the uncertainty in damage estimates for flood risk management are illustrated by a case study in which the economic optimal investment strategy for a dike segment in the Netherlands is determined. The case study shows that the uncertainty in flood damage estimates can lead to significant over- or under-investments.

Direct Reprogramming—The Future of Cardiac Regeneration?

PubMed Central

Doppler, Stefanie A.; Deutsch, Marcus-André; Lange, Rüdiger; Krane, Markus

2015-01-01

Today, the only available curative therapy for end stage congestive heart failure (CHF) is heart transplantation. This therapeutic option is strongly limited by declining numbers of available donor hearts and by restricted long-term performance of the transplanted graft. The disastrous prognosis for CHF with its restricted therapeutic options has led scientists to develop different concepts of alternative regenerative treatment strategies including stem cell transplantation or stimulating cell proliferation of different cardiac cell types in situ. However, first clinical trials with overall inconsistent results were not encouraging, particularly in terms of functional outcome. Among other approaches, very promising ongoing pre-clinical research focuses on direct lineage conversion of scar fibroblasts into functional myocardium, termed “direct reprogramming” or “transdifferentiation.” This review seeks to summarize strategies for direct cardiac reprogramming including the application of different sets of transcription factors, microRNAs, and small molecules for an efficient generation of cardiomyogenic cells for regenerative purposes. PMID:26230692

Emotional Intelligence in Incarcerated Female Offenders With Psychopathic Traits.

PubMed

Edwards, Bethany G; Ermer, Elsa; Salovey, Peter; Kiehl, Kent A

2018-03-05

Emotional impairment is a core feature of psychopathy, and the disorder has been linked to an inability to recognize and regulate emotion, leading to deficiencies in empathy and difficulties in social functioning. This study investigated associations among psychopathic traits and ability-based emotional intelligence (EI) in female offenders and integrated data with previously published male offender data (Ermer, Kahn, Salovey, & Kiehl, 2012) to examine gender differences in relationships. Results showed that female offenders were impaired in the understanding and management of emotion relative to the general population, and that female offenders scored higher than male offenders in EI. Affective psychopathic traits (e.g., callousness) yielded a small relationship with difficulties in managing emotion in female offenders, and few gender differences in relationships between psychopathy and EI were found. Findings contribute to literature on emotional functioning in females with psychopathic traits and further understanding of gender differences in emotional abilities among offenders.

Link-quality measurement and reporting in wireless sensor networks.

PubMed

Chehri, Abdellah; Jeon, Gwanggil; Choi, Byoungjo

2013-03-04

Wireless Sensor networks (WSNs) are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios.

Link-Quality Measurement and Reporting in Wireless Sensor Networks

PubMed Central

Chehri, Abdellah; Jeon, Gwanggil; Choi, Byoungjo

2013-01-01

Wireless Sensor networks (WSNs) are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios. PMID:23459389

Effects of dust size distribution on dust acoustic waves in two-dimensional unmagnetized dusty plasma

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

He Guangjun; Duan Wenshan; Tian Duoxiang

2008-04-15

For unmagnetized dusty plasma with many different dust grain species containing both hot isothermal electrons and ions, both the linear dispersion relation and the Kadomtsev-Petviashvili equation for small, but finite amplitude dust acoustic waves are obtained. The linear dispersion relation is investigated numerically. Furthermore, the variations of amplitude, width, and propagation velocity of the nonlinear solitary wave with an arbitrary dust size distribution function are studied as well. Moreover, both the power law distribution and the Gaussian distribution are approximately simulated by using appropriate arbitrary dust size distribution functions.

Transfer-function-parameter estimation from frequency response data: A FORTRAN program

NASA Technical Reports Server (NTRS)

Seidel, R. C.

1975-01-01

A FORTRAN computer program designed to fit a linear transfer function model to given frequency response magnitude and phase data is presented. A conjugate gradient search is used that minimizes the integral of the absolute value of the error squared between the model and the data. The search is constrained to insure model stability. A scaling of the model parameters by their own magnitude aids search convergence. Efficient computer algorithms result in a small and fast program suitable for a minicomputer. A sample problem with different model structures and parameter estimates is reported.

One motif to bind them: A small-XXX-small motif affects transmembrane domain 1 oligomerization, function, localization, and cross-talk between two yeast GPCRs.

PubMed

Lock, Antonia; Forfar, Rachel; Weston, Cathryn; Bowsher, Leo; Upton, Graham J G; Reynolds, Christopher A; Ladds, Graham; Dixon, Ann M

2014-12-01

G protein-coupled receptors (GPCRs) are the largest family of cell-surface receptors in mammals and facilitate a range of physiological responses triggered by a variety of ligands. GPCRs were thought to function as monomers, however it is now accepted that GPCR homo- and hetero-oligomers also exist and influence receptor properties. The Schizosaccharomyces pombe GPCR Mam2 is a pheromone-sensing receptor involved in mating and has previously been shown to form oligomers in vivo. The first transmembrane domain (TMD) of Mam2 contains a small-XXX-small motif, overrepresented in membrane proteins and well-known for promoting helix-helix interactions. An ortholog of Mam2 in Saccharomyces cerevisiae, Ste2, contains an analogous small-XXX-small motif which has been shown to contribute to receptor homo-oligomerization, localization and function. Here we have used experimental and computational techniques to characterize the role of the small-XXX-small motif in function and assembly of Mam2 for the first time. We find that disruption of the motif via mutagenesis leads to reduction of Mam2 TMD1 homo-oligomerization and pheromone-responsive cellular signaling of the full-length protein. It also impairs correct targeting to the plasma membrane. Mutation of the analogous motif in Ste2 yielded similar results, suggesting a conserved mechanism for assembly. Using co-expression of the two fungal receptors in conjunction with computational models, we demonstrate a functional change in G protein specificity and propose that this is brought about through hetero-dimeric interactions of Mam2 with Ste2 via the complementary small-XXX-small motifs. This highlights the potential of these motifs to affect a range of properties that can be investigated in other GPCRs. Copyright © 2014. Published by Elsevier B.V.

Hyperfine coupling constants of the nitrogen and phosphorus atoms: A challenge for exact-exchange density-functional and post-Hartree-Fock methods

NASA Astrophysics Data System (ADS)

Kaupp, Martin; Arbuznikov, Alexei V.; Heßelmann, Andreas; Görling, Andreas

2010-05-01

The isotropic hyperfine coupling constants of the free N(S4) and P(S4) atoms have been evaluated with high-level post-Hartree-Fock and density-functional methods. The phosphorus hyperfine coupling presents a significant challenge to both types of methods. With large basis sets, MP2 and coupled-cluster singles and doubles calculations give much too small values for the phosphorus atom. Triple excitations are needed in coupled-cluster calculations to achieve reasonable agreement with experiment. None of the standard density functionals reproduce even the correct sign of this hyperfine coupling. Similarly, the computed hyperfine couplings depend crucially on the self-consistent treatment in exact-exchange density-functional theory within the optimized effective potential (OEP) method. Well-balanced auxiliary and orbital basis sets are needed for basis-expansion exact-exchange-only OEP approaches to come close to Hartree-Fock or numerical OEP data. Results from the localized Hartree-Fock and Krieger-Li-Iafrate approximations deviate notably from exact OEP data in spite of very similar total energies. Of the functionals tested, only full exact-exchange methods augmented by a correlation functional gave at least the correct sign of the P(S4) hyperfine coupling but with too low absolute values. The subtle interplay between the spin-polarization contributions of the different core shells has been analyzed, and the influence of even very small changes in the exchange-correlation potential could be identified.

Of Small Beauties and Large Beasts: The Quality of Distractors on Multiple-Choice Tests Is More Important than Their Quantity

ERIC Educational Resources Information Center

Papenberg, Martin; Musch, Jochen

2017-01-01

In multiple-choice tests, the quality of distractors may be more important than their number. We therefore examined the joint influence of distractor quality and quantity on test functioning by providing a sample of 5,793 participants with five parallel test sets consisting of items that differed in the number and quality of distractors.…

Scale Comparability between Nonaccommodated and Accommodated Forms of a Statewide High School Assessment: Assessment Using "l[subscript z]" Person-Fit

ERIC Educational Resources Information Center

Seo, Dong Gi; Hao, Shiqi

2016-01-01

Differential item/test functioning (DIF/DTF) are routine procedures to detect item/test unfairness as an explanation for group performance difference. However, unequal sample sizes and small sample sizes have an impact on the statistical power of the DIF/DTF detection procedures. Furthermore, DIF/DTF cannot be used for two test forms without…

Clients' and workers' perceptions on clients' functional ability and need for help: home care in municipalities.

PubMed

Hammar, Teija; Perälä, Marja-Leena; Rissanen, Pekka

2009-03-01

The aim of the study was to compare clients' and named home care (HC) workers' perceptions of clients' functional ability (FA) and need for help and to analyse which client- and municipality-related factors are associated with perceptions of client's FA. The total of 686 Finnish HC clients was interviewed in 2001. Further, the questionnaire was sent to 686 HC workers. FA was assessed by activities of daily living (ADL), which included both basic/physical (PADL) and instrumental (IADL) activities. The association between client's FA and municipality-related variables was analysed by using hierarchical logistic regression models. The findings indicated that clients' and HC-workers' perceptions about what the clients were able to do were similar in the PADL functions, but perceptions differed when it comes to the IADL functions for mobility and in climbing stairs. A smaller proportion of clients compared with HC workers assessed themselves to be in need of help in all ADL functions. Use of home help and bathing services increased the probability of belonging to the 'poor' FA class while living alone and small size of municipality decreased the probability. The study indicates that although clients and workers assessed client's FA fairly similarly, there were major differences in perceptions concerning clients' needs for help in ADL functions. Clients' and workers' shared view of need for help forms a basis for high-quality care. Therefore, the perception of both the clients and workers must be taken into account when planning care and services. There was also variation in clients' FA between municipalities, although only the size of municipality had some association with the variation. The probability that clients with a lower FA are cared for in HC is higher if the clients live in large- rather than small-sized municipalities. This may reflect a better mix of services and resources in large-sized municipalities.

Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination

PubMed Central

Rejón, Juan D.; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J.

2012-01-01

Background and Aims A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. Methods The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Key Results Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. Conclusions In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma. PMID:22922586

Deterioration in physical activity and function differs according to treatment type in non-small cell lung cancer - future directions for physiotherapy management.

PubMed

Granger, C L; Parry, S M; Edbrooke, L; Denehy, L

2016-09-01

To investigate in non-surgically and surgically treated non-small cell lung cancer (NSCLC): (1) changes in physical activity, function, health-related quality of life (HRQoL) and symptoms after diagnosis; and (2) the association between physical activity and outcomes. Prospective observational study. Three acute tertiary hospitals. Sixty-nine individuals (43 male, median [IQR] age 68 [61 to 74] years) with stage I-IV NSCLC. The primary outcome (Physical Activity Scale for the Elderly) and secondary outcome (six-minute walk test and questionnaires assessing HRQoL, function, symptoms, mood) were measured at diagnosis (pre-treatment), and eight to ten weeks post-diagnosis (post-operative and/or during chemotherapy/radiotherapy). Individuals treated surgically (n=27) experienced a deterioration in physical activity levels (baseline median [IQR]=74 [51 to 135]; follow-up median [IQR]=29 [24 to 73]; median difference=45, effect size=0.3). At follow-up physical activity was inversely related to depression, pain and appetite loss (rho>0.5, p<0.05). In contrast non-surgical individuals (n=42) did not experience a change in physical activity, however did experience deterioration in function, functional capacity, global HRQoL, fatigue and dyspnoea. Physical activity levels were low in this group and at follow-up the strongest relationships with physical activity levels were global HRQoL, function, fatigue and mood (inverse, rho>0.5, p<0.05). Surgically treated individuals experienced a reduction in physical activity levels after diagnosis, which was not seen in the non-surgical group. Lower physical activity levels were associated with poorer outcomes, particularly in non-surgically treated individuals. Further research is required to establish the optimal intervention to improve physical activity levels in these cohorts. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

From Macromolecular to Small-Molecular Triggers: Facile Method toward Photoinduced LCST Phase Behavior of Thermoresponsive Polymers in Mixed Ionic Liquids Containing an Azobenzene Moiety.

PubMed

Wang, Caihong; Ma, Xiaofeng; Kitazawa, Yuzo; Kobayashi, Yumi; Zhang, Shiguo; Kokubo, Hisashi; Watanabe, Masayoshi

2016-12-01

Instead of the reported photoinduced lower critical solution temperature (LCST) phase transition behavior in ionic liquids (ILs) achieved by photofunctional polymers, this study reports the facile photoinduced LCST phase behavior of nonfunctionalized polymers (poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA)) in mixed ILs (1,3-dimethylimidazolium bis(trifluoromethanesulfonyl)amide; [C 1 mim][NTf 2 ] and a newly designed functionalized IL containing an azobenzene moiety (1-butyl-3-(4-phenylazobenzyl)imidazolium bis(trifluoromethanesulfonyl)amide; [Azo][NTf 2 ])) as a small-molecular photo trigger. Interestingly, the length of the alkyl spacer between the ester and aryl groups, which is the only structural difference between the two polymers, leads to two different photoresponsive LCST phase transition behaviors. On the basis of spectroscopic studies, the different phase transition behaviors of PBnMA and PPhEtMA may attribute to the different cooperative interactions between the polymers and [C 1 mim][NTf 2 ]. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In silico quantitative structure-toxicity relationship study of aromatic nitro compounds.

PubMed

Pasha, Farhan Ahmad; Neaz, Mohammad Morshed; Cho, Seung Joo; Ansari, Mohiuddin; Mishra, Sunil Kumar; Tiwari, Sharvan

2009-05-01

Small molecules often have toxicities that are a function of molecular structural features. Minor variations in structural features can make large difference in such toxicity. Consequently, in silico techniques may be used to correlate such molecular toxicities with their structural features. Relative to nine different sets of aromatic nitro compounds having known observed toxicities against different targets, we developed ligand-based 2D quantitative structure-toxicity relationship models using 20 selected topological descriptors. The topological descriptors have several advantages such as conformational independency, facile and less time-consuming computation to yield good results. Multiple linear regression analysis was used to correlate variations of toxicity with molecular properties. The information index on molecular size, lopping centric index and Kier flexibility index were identified as fundamental descriptors for different kinds of toxicity, and further showed that molecular size, branching and molecular flexibility might be particularly important factors in quantitative structure-toxicity relationship analysis. This study revealed that topological descriptor-guided quantitative structure-toxicity relationship provided a very useful, cost and time-efficient, in silico tool for describing small-molecule toxicities.

On non-primitively divergent vertices of Yang-Mills theory

NASA Astrophysics Data System (ADS)

Huber, Markus Q.

2017-11-01

Two correlation functions of Yang-Mills beyond the primitively divergent ones, the two-ghost-two-gluon and the four-ghost vertices, are calculated and their influence on lower vertices is examined. Their full (transverse) tensor structure is taken into account. As input, a solution of the full two-point equations - including two-loop terms - is used that respects the resummed perturbative ultraviolet behavior. A clear hierarchy is found with regard to the color structure that reduces the number of relevant dressing functions. The impact of the two-ghost-two-gluon vertex on the three-gluon vertex is negligible, which is explained by the fact that all non-small dressing functions drop out due to their color factors. Only in the ghost-gluon vertex a small net effect below 2% is seen. The four-ghost vertex is found to be extremely small in general. Since these two four-point functions do not enter into the propagator equations, these findings establish their small overall effect on lower correlation functions.

Visual discrimination in the pigeon (Columba livia): effects of selective lesions of the nucleus rotundus

NASA Technical Reports Server (NTRS)

Laverghetta, A. V.; Shimizu, T.

1999-01-01

The nucleus rotundus is a large thalamic nucleus in birds and plays a critical role in many visual discrimination tasks. In order to test the hypothesis that there are functionally distinct subdivisions in the nucleus rotundus, effects of selective lesions of the nucleus were studied in pigeons. The birds were trained to discriminate between different types of stationary objects and between different directions of moving objects. Multiple regression analyses revealed that lesions in the anterior, but not posterior, division caused deficits in discrimination of small stationary stimuli. Lesions in neither the anterior nor posterior divisions predicted effects in discrimination of moving stimuli. These results are consistent with a prediction led from the hypothesis that the nucleus is composed of functional subdivisions.

Challenges in Development of Sperm Repositories for Biomedical Fishes: Quality Control in Small-Bodied Species.

PubMed

Torres, Leticia; Liu, Yue; Guitreau, Amy; Yang, Huiping; Tiersch, Terrence R

2017-12-01

Quality control (QC) is essential for reproducible and efficient functioning of germplasm repositories. However, many biomedical fish models present significant QC challenges due to small body sizes (<5 cm) and miniscule sperm volumes (<5 μL). Using minimal volumes of sperm, we used Zebrafish to evaluate common QC endpoints as surrogates for fertilization success along sequential steps of cryopreservation. First, concentrations of calibration bead suspensions were evaluated with a Makler ® counting chamber by using different sample volumes and mixing methods. For sperm analysis, samples were initially diluted at a 1:30 ratio with Hanks' balanced salt solution (HBSS). Motility was evaluated by using different ratios of sperm and activation medium, and membrane integrity was analyzed with flow cytometry at different concentrations. Concentration and sperm motility could be confidently estimated by using volumes as small as 1 μL, whereas membrane integrity required a minimum of 2 μL (at 1 × 10 6 cells/mL). Thus, <5 μL of sperm suspension (after dilution to 30-150 μL with HBSS) was required to evaluate sperm quality by using three endpoints. Sperm quality assessment using a combination of complementary endpoints enhances QC efforts during cryopreservation, increasing reliability and reproducibility, and reducing waste of time and resources.

Localized states and their stability in an anharmonic medium with a nonlinear defect

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

Gerasimchuk, I. V., E-mail: igor.gera@gmail.com

2015-10-15

A comprehensive analysis of soliton states localized near a plane defect (a defect layer) possessing nonlinear properties is carried out within a quasiclassical approach for different signs of nonlinearity of the medium and different characters of interaction of elementary excitations of the medium with the defect. A quantum interpretation is given to these nonlinear localized modes as a bound state of a large number of elementary excitations. The domains of existence of such states are determined, and their properties are analyzed as a function of the character of interaction of elementary excitations between each other and with the defect. Amore » full analysis of the stability of all the localized states with respect to small perturbations of amplitude and phase is carried out analytically, and the frequency of small oscillations of the state localized on the defect is determined.« less

Volatility return intervals analysis of the Japanese market

NASA Astrophysics Data System (ADS)

Jung, W.-S.; Wang, F. Z.; Havlin, S.; Kaizoji, T.; Moon, H.-T.; Stanley, H. E.

2008-03-01

We investigate scaling and memory effects in return intervals between price volatilities above a certain threshold q for the Japanese stock market using daily and intraday data sets. We find that the distribution of return intervals can be approximated by a scaling function that depends only on the ratio between the return interval τ and its mean <τ>. We also find memory effects such that a large (or small) return interval follows a large (or small) interval by investigating the conditional distribution and mean return interval. The results are similar to previous studies of other markets and indicate that similar statistical features appear in different financial markets. We also compare our results between the period before and after the big crash at the end of 1989. We find that scaling and memory effects of the return intervals show similar features although the statistical properties of the returns are different.

A laboratory model of a hydrogen/oxygen engine for combustion and nozzle studies

NASA Technical Reports Server (NTRS)

Morren, Sybil H.; Myers, Roger M.; Benko, Stephen E.; Arrington, Lynn A.; Reed, Brian D.

1993-01-01

A small laboratory diagnostic thruster was developed in order to evaluate approaches for the use of temperature and pressure sensors for the investigation of low thrust rocket flowfields. Tests were performed at chamber pressures of about 255 kPa, 370 kPa, and 500 kPa with oxidizer/fuel mixture ratios between 4.0 and 8.0. Two gaseous hydrogen/gaseous oxygen injector designs were tested with 60 and 75 fuel film cooling. The results of hot-wire tests showed the thruster and instrumentation designs to be effective. Azimuthal temperature distributions were found to be a function of operating conditions and hardware configuration. Results indicated that small differences in injector design can result in dramatically different thruster performance and wall temperature behavior. However, the importance of these injector effects may be decreased by operating at a high fuel film cooling rate.

Drivers of solar radiation variability in the McMurdo Dry Valleys, Antarctica

USGS Publications Warehouse

Obryk, Maciej; Fountain, Andrew G.; Doran, Peter; Lyons, Berry; Eastman, Ryan

2018-01-01

Annually averaged solar radiation in the McMurdo Dry Valleys, Antarctica has varied by over 20 W m−2 during the past three decades; however, the drivers of this variability are unknown. Because small differences in radiation are important to water availability and ecosystem functioning in polar deserts, determining the causes are important to predictions of future desert processes. We examine the potential drivers of solar variability and systematically eliminate all but stratospheric sulfur dioxide. We argue that increases in stratospheric sulfur dioxide increase stratospheric aerosol optical depth and decrease solar intensity. Because of the polar location of the McMurdo Dry Valleys (77–78°S) and relatively long solar ray path through the stratosphere, terrestrial solar intensity is sensitive to small differences in stratospheric transmissivity. Important sources of sulfur dioxide include natural (wildfires and volcanic eruptions) and anthropogenic emission.

Differential gene expression in small and large rainbow trout derived from two seasonal spawning groups

PubMed Central

2014-01-01

Background Growth in fishes is regulated via many environmental and physiological factors and is shaped by the genetic background of each individual. Previous microarray studies of salmonid growth have examined fish experiencing either muscle wastage or accelerated growth patterns following refeeding, or the influence of growth hormone and transgenesis. This study determines the gene expression profiles of genetically unmanipulated large and small fish from a domesticated salmonid strain reared on a typical feeding regime. Gene expression profiles of white muscle and liver from rainbow trout (Oncorhynchus mykiss) from two seasonal spawning groups (September and December lots) within a single strain were examined when the fish were 15 months of age to assess the influence of season (late fall vs. onset of spring) and body size (large vs. small). Results Although IGFBP1 gene expression was up-regulated in the livers of small fish in both seasonal lots, few expression differences were detected in the liver overall. Faster growing Dec. fish showed a greater number of differences in white muscle expression compared to Sept. fish. Significant differences in the GO Generic Level 3 categories ‘response to external stimulus’, ‘establishment of localization’, and ‘response to stress’ were detected in white muscle tissue between large and small fish. Larger fish showed up-regulation of cytoskeletal component genes while many genes related to myofibril components of muscle tissue were up-regulated in small fish. Most of the genes up-regulated in large fish within the ‘response to stress’ category are involved in immunity while in small fish most of these gene functions are related to apoptosis. Conclusions A higher proportion of genes in white muscle compared to liver showed similar patterns of up- or down-regulation within the same size class across seasons supporting their utility as biomarkers for growth in rainbow trout. Differences between large and small Sept. fish in the ‘response to stress’ and ‘response to external stimulus’ categories for white muscle tissue, suggests that smaller fish have a greater inability to handle stress compared to the large fish. Sampling season had a significant impact on the expression of genes related to the growth process in rainbow trout. PMID:24450799

Liquid Structure of CO 2 –Reactive Aprotic Heterocyclic Anion Ionic Liquids from X-ray Scattering and Molecular Dynamics

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

Sheridan, Quintin R.; Oh, Seungmin; Morales-Collazo, Oscar

2016-11-23

A combination of X-ray scattering experiments and molecular dynamics simulations were conducted to investigate the structure of ionic liquids (ILs) which chemically bind CO 2. The structure functions were measured and computed for four different ILs consisting of two different phosphonium cations, triethyloctylphosphonium ([P 2228] +) and trihexyltetradecylphosphonium ([P 66614] +), paired with two different aprotic heterocyclic anions which chemically react with CO 2, 2-cyanopyrrolide, and 1,2,4-triazolide. Simulations were able to reproduce the experimental structure functions, and by deconstructing the simulated structure functions, further information on the liquid structure was obtained. All structure functions of the ILs studied had threemore » primary features which have been seen before in other ILs: a prepeak near 0.3–0.4 Å–1 corresponding to polar/nonpolar domain alternation, a charge alternation peak near 0.8 Å–1, and a peak near 1.5 Å–1 due to interactions of adjacent molecules. The liquid structure functions were only mildly sensitive to the specific anion and whether or not they were reacted with CO 2. Upon reacting with CO 2, small changes were observed in the structure functions of the [P 2228] + ILs, whereas virtually no change was observed upon reacting with CO 2 in the corresponding [P 66614] + ILs. When the [P 2228] + cation was replaced with the [P 66614] + cation, there was a significant increase in the intensities of the prepeak and adjacency interaction peak. While many of the liquid structure functions are similar, the actual liquid structures differ as demonstrated by computed spatial distribution functions.« less

Valproic acid-inducible Arl4D and cytohesin-2/ARNO, acting through the downstream Arf6, regulate neurite outgrowth in N1E-115 cells.

PubMed

Yamauchi, Junji; Miyamoto, Yuki; Torii, Tomohiro; Mizutani, Reiko; Nakamura, Kazuaki; Sanbe, Atsushi; Koide, Hiroshi; Kusakawa, Shinji; Tanoue, Akito

2009-07-15

The mood-stabilizing agent valproic acid (VPA) potently promotes neuronal differentiation. As yet, however, little is known about the underlying molecular mechanism. Here, we show that VPA upregulates cytohesin-2 and mediates neurite outgrowth in N1E-115 neuroblastoma cells. Cytohesin-2 is the guanine-nucleotide exchange factor (GEF) for small GTPases of the Arf family; it regulates many aspects of cellular functions including morphological changes. Treatment with the specific cytohesin family inhibitor SecinH3 or knockdown of cytohesin-2 with its siRNA results in blunted induction of neurite outgrowth in N1E-115 cells. The outgrowth is specifically inhibited by siRNA knockdown of Arf6, but not by that of Arf1. Furthermore, VPA upregulates Arl4D, an Arf-like small GTPase that has recently been identified as the regulator that binds to cytohesin-2. Arl4D knockdown displays an inhibitory effect on neurite outgrowth resulting from VPA, while expression of constitutively active Arl4D induces outgrowth. We also demonstrate that the addition of cell-permeable peptide, coupling the cytohesin-2-binding region of Arl4D into cells, reduces the effect of VPA. Thus, Arl4D is a previously unknown regulator of neurite formation through cytohesin-2 and Arf6, providing another example that the functional interaction of two different small GTPases controls an important cellular function.

BORC Functions Upstream of Kinesins 1 and 3 to Coordinate Regional Movement of Lysosomes along Different Microtubule Tracks.

PubMed

Guardia, Carlos M; Farías, Ginny G; Jia, Rui; Pu, Jing; Bonifacino, Juan S

2016-11-15

The multiple functions of lysosomes are critically dependent on their ability to undergo bidirectional movement along microtubules between the center and the periphery of the cell. Centrifugal and centripetal movement of lysosomes is mediated by kinesin and dynein motors, respectively. We recently described a multi-subunit complex named BORC that recruits the small GTPase Arl8 to lysosomes to promote their kinesin-dependent movement toward the cell periphery. Here, we show that BORC and Arl8 function upstream of two structurally distinct kinesin types: kinesin-1 (KIF5B) and kinesin-3 (KIF1Bβ and KIF1A). Remarkably, KIF5B preferentially moves lysosomes on perinuclear tracks enriched in acetylated α-tubulin, whereas KIF1Bβ and KIF1A drive lysosome movement on more rectilinear, peripheral tracks enriched in tyrosinated α-tubulin. These findings establish BORC as a master regulator of lysosome positioning through coupling to different kinesins and microtubule tracks. Common regulation by BORC enables coordinate control of lysosome movement in different regions of the cell. Published by Elsevier Inc.

BORC Functions Upstream of Kinesins 1 and 3 to Coordinate Regional Movement of Lysosomes Along Different Microtubule Tracks

PubMed Central

Guardia, Carlos M.; Farías, Ginny G.; Jia, Rui; Pu, Jing; Bonifacino, Juan S.

2016-01-01

Summary The multiple functions of lysosomes are critically dependent on their ability to undergo bidirectional movement along microtubules between the center and the periphery of the cell. Centrifugal and centripetal movement of lysosomes is mediated by kinesin and dynein motors, respectively. We recently described a multisubunit complex named BORC that recruits the small GTPase Arl8 to lysosomes to promote their kinesin-dependent movement toward the cell periphery. Here we show that BORC and Arl8 function upstream of two structurally distinct kinesin types: kinesin-1 (KIF5B) and kinesin-3 (KIF1Bβ and KIF1A). Remarkably, KIF5B preferentially moves lysosomes on perinuclear tracks enriched in acetylated α-tubulin, whereas KIF1Bβ and KIF1A drive lysosome movement on more rectilinear, peripheral tracks enriched in tyrosinated α-tubulin. These findings establish BORC as a master regulator of lysosome positioning through coupling to different kinesins and microtubule tracks. Common regulation by BORC enables coordinate control of lysosome movement in different regions of the cell. PMID:27851960

Quality of life and functioning of Hispanic patients with Major Depressive Disorder before and after treatment.

PubMed

López, Enrique; Steiner, Alexander J; Manier, Karra; Shapiro, Bryan B; Vanle, Brigitte; Parisi, Thomas; Dang, Jonathan; Chang, Tiffany; Ganjian, Shaina; Mirocha, James; Danovitch, Itai; IsHak, Waguih William

2018-01-01

Similar rates of remission from Major Depressive Disorder (MDD) have been documented between ethnic groups in response to antidepressant treatment. However, ethnic differences in functional outcomes, including patient-reported quality of life (QOL) and functioning, have not been well-characterized. We compared symptomatic and functional outcomes of antidepressant treatment in Hispanic and non-Hispanic patients with MDD. We analyzed 2280 nonpsychotic treatment-seeking adults with MDD who received citalopram monotherapy in Level 1 of the Sequenced Treatment Alternatives to Relieve Depression study. All subjects (239 Hispanic, 2041 non-Hispanic) completed QOL, functioning, and depressive symptom severity measures at entry and exit. Hispanic participants had significantly worse QOL scores at entry and exit (p < 0.01). However, after controlling for baseline QOL, there was no difference between Hispanic and non-Hispanic patients' QOL at exit (p = 0.21). There were no significant between-group differences at entry or at exit for depressive symptom severity or functioning. Both groups had significant improvements in depressive symptom severity, QOL, and functioning from entry to exit (all p values < 0.01). Patients with private insurance had lower depressive symptom severity, greater QOL, and better functioning at exit compared to patients without private insurance. This study was a retrospective data analysis, and the Hispanic group was relatively small compared to the non-Hispanic group. Hispanic and non-Hispanic participants with MDD had similar responses to antidepressant treatment as measured by depressive symptom severity scores, quality of life, and functioning. Nevertheless, Hispanic patients reported significantly worse quality of life at entry. Copyright © 2017 Elsevier B.V. All rights reserved.

Identifying Predictors, Moderators, and Mediators of Antidepressant Response in Major Depressive Disorder: Neuroimaging Approaches

PubMed Central

Phillips, Mary L.; Chase, Henry W.; Sheline, Yvette I.; Etkin, Amit; Almeida, Jorge R.C.; Deckersbach, Thilo; Trivedi, Madhukar H.

2015-01-01

Objective Despite significant advances in neuroscience and treatment development, no widely accepted biomarkers are available to inform diagnostics or identify preferred treatments for individuals with major depressive disorder. Method In this critical review, the authors examine the extent to which multimodal neuroimaging techniques can identify biomarkers reflecting key pathophysiologic processes in depression and whether such biomarkers may act as predictors, moderators, and mediators of treatment response that might facilitate development of personalized treatments based on a better understanding of these processes. Results The authors first highlight the most consistent findings from neuroimaging studies using different techniques in depression, including structural and functional abnormalities in two parallel neural circuits: serotonergically modulated implicit emotion regulation circuitry, centered on the amygdala and different regions in the medial prefrontal cortex; and dopaminergically modulated reward neural circuitry, centered on the ventral striatum and medial prefrontal cortex. They then describe key findings from the relatively small number of studies indicating that specific measures of regional function and, to a lesser extent, structure in these neural circuits predict treatment response in depression. Conclusions Limitations of existing studies include small sample sizes, use of only one neuroimaging modality, and a focus on identifying predictors rather than moderators and mediators of differential treatment response. By addressing these limitations and, most importantly, capitalizing on the benefits of multimodal neuroimaging, future studies can yield moderators and mediators of treatment response in depression to facilitate significant improvements in shorter- and longer-term clinical and functional outcomes. PMID:25640931

Changes in the Peripheral Blood Gene Expression Profile Induced by 3 Months of Valproate Treatment in Patients with Newly Diagnosed Epilepsy

PubMed Central

Rakitin, Aleksei; Kõks, Sulev; Reimann, Ene; Prans, Ele; Haldre, Sulev

2015-01-01

Valproic acid (VPA) is a widely used antiepileptic drug with a broad range of effects and broad clinical efficacy. As a well-known histone deacetylase (HDAC) inhibitor, VPA regulates epigenetic programming by altering the expression of many genes. The aim of study was to analyze differences in gene expression profiles before and after the start of VPA treatment in patients with newly diagnosed epilepsy. RNA sequencing was used to compare whole-genome gene expression patterns of peripheral blood from nine patients with epilepsy before and 3 months after the start of treatment with VPA. Of the 23,099 analyzed genes, only 11 showed statistically significant differential expression with false discovery rate-adjusted p-values below 0.1. Functional annotation and network analyses showed activation of only one genetic network (enrichment score = 30), which included genes for cardiovascular system development and function, cell morphology, and hematological system development and function. The finding of such a small number of differently expressed genes between before and after the start of treatment suggests a lack of HDAC inhibition in these patients, which could be explained by the relatively low doses of VPA that were used. In conclusion, VPA at standard therapeutic dosages modulates the expression of a small number of genes. Therefore, to minimize the potential side effects of HDAC inhibition, it is recommended that the lowest effective dose of VPA be used for treating epilepsy. PMID:26379622

75 FR 60830 - Surrender of License of Small Business Investment Company

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... Business Administration Rules and Regulations (13 CFR 107.1900) to function as a small business investment... SMALL BUSINESS ADMINISTRATION Surrender of License of Small Business Investment Company Pursuant to the authority granted to the United States Small Business Administration under the Small Business...

Simultaneous sequencing of coding and noncoding RNA reveals a human transcriptome dominated by a small number of highly expressed noncoding genes.

PubMed

Boivin, Vincent; Deschamps-Francoeur, Gabrielle; Couture, Sonia; Nottingham, Ryan M; Bouchard-Bourelle, Philia; Lambowitz, Alan M; Scott, Michelle S; Abou-Elela, Sherif

2018-07-01

Comparing the abundance of one RNA molecule to another is crucial for understanding cellular functions but most sequencing techniques can target only specific subsets of RNA. In this study, we used a new fragmented ribodepleted TGIRT sequencing method that uses a thermostable group II intron reverse transcriptase (TGIRT) to generate a portrait of the human transcriptome depicting the quantitative relationship of all classes of nonribosomal RNA longer than 60 nt. Comparison between different sequencing methods indicated that FRT is more accurate in ranking both mRNA and noncoding RNA than viral reverse transcriptase-based sequencing methods, even those that specifically target these species. Measurements of RNA abundance in different cell lines using this method correlate with biochemical estimates, confirming tRNA as the most abundant nonribosomal RNA biotype. However, the single most abundant transcript is 7SL RNA, a component of the signal recognition particle. S tructured n on c oding RNAs (sncRNAs) associated with the same biological process are expressed at similar levels, with the exception of RNAs with multiple functions like U1 snRNA. In general, sncRNAs forming RNPs are hundreds to thousands of times more abundant than their mRNA counterparts. Surprisingly, only 50 sncRNA genes produce half of the non-rRNA transcripts detected in two different cell lines. Together the results indicate that the human transcriptome is dominated by a small number of highly expressed sncRNAs specializing in functions related to translation and splicing. © 2018 Boivin et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Comparison of surgical outcomes after pneumonectomy and pulmonary function-preserving surgery for non-small cell lung cancer.

PubMed

Higuchi, Mitsunori; Takagi, Hironori; Ozaki, Yuki; Inoue, Takuya; Watanabe, Yuzuru; Yamaura, Takumi; Fukuhara, Mitsuro; Muto, Satoshi; Okabe, Naoyuki; Matsumura, Yuki; Hasegawa, Takeo; Osugi, Jun; Hoshino, Mika; Shio, Yutaka; Suzuki, Hiroyuki

2018-04-17

According to previous reports, lobectomy with bronchoplasty or angioplasty is a more feasible surgery than pneumonectomy for central-type non-small cell lung cancer. However, few studies have compared both the short- and long-term outcomes between pneumonectomy and pulmonary function-preserving surgery. From January 2004 to December 2015, 18 patients underwent pneumonectomy (Group PN) and 12 patients underwent pulmonary function-preserving surgery (group PS) at Fukushima Medical University Hospital. Clinicopathological factors were statistically compared between the two groups. The operation times in Group PN and Group PS were 285.9±27.9 and 271.3±99.2 min, respectively (p=0.613), while the amounts of intraoperative bleeding were 324.8±248.9 and 164.5±116.6 g, respectively (p=0.020). The duration of chest drainage and hospitalization after surgery in both groups were not significantly different but there was a tendency toward shorter periods of these durations in Group PS. The 5-year disease-free survival (DFS) rate in Group PN and PS was 51.4% and 74.1%, respectively, without a significant difference (p=0.298). The 5-year overall survival (OS) rate in Group PN and PS was 52.5% and 56.6%, respectively, also without a significant difference (p=0.748). The 5-year OS rate was inferior to the 5-year DFS rate in Group PS, and the 5-year OS rate was not better than the 5-year DFS rate in Group PN. The short-term results were better in Group PS than PN. However, the long-term results in both groups were similar. Other causes of death influenced OS in both groups; this result might have been affected by the surgical procedures.

Substrates for Neuronal Cotransmission With Neuropeptides and Small Molecule Neurotransmitters in Drosophila

PubMed Central

Nässel, Dick R.

2018-01-01

It has been known for more than 40 years that individual neurons can produce more than one neurotransmitter and that neuropeptides often are colocalized with small molecule neurotransmitters (SMNs). Over the years much progress has been made in understanding the functional consequences of cotransmission in the nervous system of mammals. There are also some excellent invertebrate models that have revealed roles of coexpressed neuropeptides and SMNs in increasing complexity, flexibility, and dynamics in neuronal signaling. However, for the fly Drosophila there are surprisingly few functional studies on cotransmission, although there is ample evidence for colocalization of neuroactive compounds in neurons of the CNS, based both on traditional techniques and novel single cell transcriptome analysis. With the hope to trigger interest in initiating cotransmission studies, this review summarizes what is known about Drosophila neurons and neuronal circuits where different neuropeptides and SMNs are colocalized. Coexistence of neuroactive substances has been recorded in different neuron types such as neuroendocrine cells, interneurons, sensory cells and motor neurons. Some of the circuits highlighted here are well established in the analysis of learning and memory, circadian clock networks regulating rhythmic activity and sleep, as well as neurons and neuroendocrine cells regulating olfaction, nociception, feeding, metabolic homeostasis, diuretic functions, reproduction, and developmental processes. One emerging trait is the broad role of short neuropeptide F in cotransmission and presynaptic facilitation in a number of different neuronal circuits. This review also discusses the functional relevance of coexisting peptides in the intestine. Based on recent single cell transcriptomics data, it is likely that the neuronal systems discussed in this review are just a fraction of the total set of circuits where cotransmission occurs in Drosophila. Thus, a systematic search for colocalized neuroactive compounds in further neurons in anatomically defined circuits is of interest for the near future. PMID:29651236

Catastrophe theory: What it is—Why it exists—How it works

NASA Astrophysics Data System (ADS)

Gilmore, Robert

1996-06-01

Push on something. It will move. Push a little bit harder and it will move a little bit more. But occasionally a little extra push will produce an extra large response. Such extra responses are called ``catastrophes.'' This kind of behavior is summarized by the phrase ``... the straw that broke the camel's back.'' Situations in which a gradually increasing force leads to a gradually increasing response, followed by a sudden catastrophic jump to a qualitatively different state, are all too common. They are seen, for example, in the collapse of a bridge, dam, or building; the loss of stability of an aircraft or ship; phase transitions in fluids or solids; ignition of a laser; sudden changes in the earth's climate. In each of the instances above, and very many others besides, it is possible to see a smooth response and a discontinuous response to a smoothly changing force. It might seem that ``Every smooth response is the same, each discontinuous response is discontinuous in its own fashion.'' In fact, every smooth process is conveniently described by a linear response function or tensor. However, it is not true that every discontinuity is different. Discontinuities are described by mathematical functions called catastrophe functions. Only a relatively small number of such functions exist. These have been extensively studied. They can be constructed for any physical system. The simplest of these have been studied extensively. The result is that only a handful of different types of discontinuities are typically encountered, and each of these exhibits a characteristic set of properties. A parallel realization that a relatively small number of features characterizes the complex behavior exhibited by nonlinear dynamical systems (sets of ordinary differential equations) has catalyzed the rapid growth of interest in such systems in the last two decades. In the following sections we describe catastrophe theory. In particular, we describe what it is, why it exists, and how it works.

Effects on interaction kinetics of mutations at the VH-VL interface of Fabs depend on the structural context.

PubMed

Khalifa, M B; Weidenhaupt, M; Choulier, L; Chatellier, J; Rauffer-Bruyère, N; Altschuh, D; Vernet, T

2000-01-01

The influence of framework residues belonging to VH and VL modules of antibody molecules on antigen binding remains poorly understood. To investigate the functional role of such residues, we have performed semi-conservative amino acid replacements at the VH-VL interface. This work was carried out with (i) variants of the same antibody and (ii) with antibodies of different specificities (Fab fragments 145P and 1F1h), in order to check if functional effects are additive and/or similar for the two antibodies. Interaction kinetics of Fab mutants with peptide and protein antigens were measured using a BIACORE instrument. The substitutions introduced at the VH-VL interface had no significant effects on k(a) but showed small, significant effects on k(d). Mutations in the VH module affected k(d) not only for the two different antibodies but also for variants of the same antibody. These effects varied both in direction and in magnitude. In the VL module, the double mutation F(L37)L-Q(L38)L, alone or in combination with other mutations, consistently decreased k(d) about two-fold in Fab 145P. Other mutations in the VL module had no effect on k(d) in 145P, but always decreased k(d) in 1F1h. Moreover, in both systems, small-magnitude non-additive effects on k(d) were observed, but affinity variations seemed to be limited by a threshold. When comparing functional effects in antibodies of different specificity, no general rules could be established. In addition, no clear relationship could be pointed out between the nature of the amino acid change and the observed functional effect. Our results show that binding kinetics are affected by alteration of framework residues remote from the binding site, although these effects are unpredictable for most of the studied changes. Copyright 2000 John Wiley & Sons, Ltd.

Incomplete aneurysm coverage after patent foramen ovale closure in patients with huge atrial septal aneurysm: effects on left atrial functional remodeling.

PubMed

Rigatelli, Gianluca; Ronco, Federico; Cardaioli, Paolo; Dell'avvocata, Fabio; Braggion, Gabriele; Giordan, Massimo; Aggio, Silvio

2010-08-01

Large devices are often implanted to treat patent foramen ovale (PFO) and atrial septal aneurysm (ASA) with increase risk of erosion and thrombosis. Our study is aimed to assess the impact on left atrium functional remodeling and clinical outcomes of partial coverage of the approach using moderately small Amplatzer ASD Cribriform Occluder in patients with large PFO and ASA. We prospectively enrolled 30 consecutive patients with previous stroke (mean age 36 +/- 9.5 years, 19 females), significant PFO, and large ASA referred to our center for catheter-based PFO closure. Left atrium (LA) passive and active emptying, LA conduit function, and LA ejection fraction were computed before and after 6 months from the procedure by echocardiography. The preclosure values were compared to values of a normal healthy population of sex and heart rate matched 30 patients. Preclosure values demonstrated significantly greater reservoir function as well as passive and active emptying, with significantly reduced conduit function and LA ejection fraction, when compared normal healthy subjects. All patients underwent successful transcatheter closure (25 mm device in 15 patients, 30 mm device in 6 patients, mean ratio device/diameter of the interatrial septum = 0.74). Incomplete ASA coverage in both orthogonal views was observed in 21 patients. Compared to patients with complete coverage, there were no differences in LA functional parameters and occlusion rates. This study confirmed that large ASAs are associated with LA dysfunction. The use of relatively small Amplatzer ASD Cribriform Occluder devices is probably effective enough to promote functional remodeling of the left atrium.

Morphology and function of Neandertal and modern human ear ossicles

PubMed Central

David, Romain; Gunz, Philipp; Schmidt, Tobias; Spoor, Fred; Hublin, Jean-Jacques

2016-01-01

The diminutive middle ear ossicles (malleus, incus, stapes) housed in the tympanic cavity of the temporal bone play an important role in audition. The few known ossicles of Neandertals are distinctly different from those of anatomically modern humans (AMHs), despite the close relationship between both human species. Although not mutually exclusive, these differences may affect hearing capacity or could reflect covariation with the surrounding temporal bone. Until now, detailed comparisons were hampered by the small sample of Neandertal ossicles and the unavailability of methods combining analyses of ossicles with surrounding structures. Here, we present an analysis of the largest sample of Neandertal ossicles to date, including many previously unknown specimens, covering a wide geographic and temporal range. Microcomputed tomography scans and 3D geometric morphometrics were used to quantify shape and functional properties of the ossicles and the tympanic cavity and make comparisons with recent and extinct AMHs as well as African apes. We find striking morphological differences between ossicles of AMHs and Neandertals. Ossicles of both Neandertals and AMHs appear derived compared with the inferred ancestral morphology, albeit in different ways. Brain size increase evolved separately in AMHs and Neandertals, leading to differences in the tympanic cavity and, consequently, the shape and spatial configuration of the ossicles. Despite these different evolutionary trajectories, functional properties of the middle ear of AMHs and Neandertals are largely similar. The relevance of these functionally equivalent solutions is likely to conserve a similar auditory sensitivity level inherited from their last common ancestor. PMID:27671643

Change in Minimum Orbit Intersection Distance due to General Relativistic Precession in Small Solar System Bodies

NASA Astrophysics Data System (ADS)

Sekhar, Aswin; Valsecchi, Giovanni B.; Asher, David; Werner, Stephanie; Vaubaillon, Jeremie; Li, Gongjie

2017-06-01

One of the greatest successes of Einstein's General Theory of Relativity (GR) was the correct prediction of the perihelion precession of Mercury. The closed form expression to compute this precession tells us that substantial GR precession would occur only if the bodies have a combination of both moderately small perihelion distance and semi-major axis. Minimum Orbit Intersection Distance (MOID) is a quantity which helps us to understand the closest proximity of two orbits in space. Hence evaluating MOID is crucial to understand close encounters and collision scenarios better. In this work, we look at the possible scenarios where a small GR precession in argument of pericentre can create substantial changes in MOID for small bodies ranging from meteoroids to comets and asteroids.Previous works have looked into neat analytical techniques to understand different collision scenarios and we use those standard expressions to compute MOID analytically. We find the nature of this mathematical function is such that a relatively small GR precession can lead to drastic changes in MOID values depending on the initial value of argument of pericentre. Numerical integrations were done with the MERCURY package incorporating GR code to test the same effects. A numerical approach showed the same interesting relationship (as shown by analytical theory) between values of argument of pericentre and the peaks or dips in MOID values. There is an overall agreement between both analytical and numerical methods.We find that GR precession could play an important role in the calculations pertaining to MOID and close encounter scenarios in the case of certain small solar system bodies (depending on their initial orbital elements) when long term impact risk possibilities are considered. Previous works have looked into impact probabilities and collision scenarios on planets from different small body populations. This work aims to find certain sub-sets of small bodies where GR could play an interesting role. Certain parallels are drawn between the cases of asteroids, comets and small perihelion distance meteoroid streams.

Effectiveness of functional training on cardiorespiratory parameters: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Rezende Barbosa, Marianne Penachini da Costa de; Oliveira, Vinicius Cunha; Silva, Anne Kastelianne França da; Pérez-Riera, Andrés Ricardo; Vanderlei, Luiz Carlos

2017-07-28

Functional training is a new training vision that was prepared from the gesture imitation of daily activities. Although your use has become popular in clinical practice, the influence of the several cardiorespiratory adjustments performed during the functional training in different populations and conditions is unknown. So, the aim of this systematic review was to gather information in the literature regarding the influence of functional training on cardiorespiratory parameters. We conducted search strategies on MEDLINE, PEDro, EMBASE, SportDiscus and Cochrane to identify randomized controlled trials investigating the effects of functional training on cardiorespiratory parameters. Methodological quality of the included studies was assessed using the PEDro scale. Grading of Recommendations Assessment, Development and Evaluation (GRADE) summarized the evidence. Five original studies were included. Effects favoured functional training on oxygen consumption (VO 2 ) at intermediate-term follow-up: weighted mean difference -1·0 (95% CI: 5·4-3·3), P = 0·642, and a small and not clinically important effect observed on VO 2 favouring control at intermediate-term follow-up (i.e. mean difference of 1·30 (95% CI 1·07-1·53), P<0·001). According to the GRADE system, there is very low quality evidence that functional training is better than other interventions to improve cardiovascular parameters. This result encourages new searches about the theme. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Quality of life and emotional functioning in youth with chronic migraine and juvenile fibromyalgia.

PubMed

Kashikar-Zuck, Susmita; Zafar, Marium; Barnett, Kimberly A; Aylward, Brandon S; Strotman, Daniel; Slater, Shalonda K; Allen, Janelle R; Lecates, Susan L; Kabbouche, Marielle A; Ting, Tracy V; Hershey, Andrew D; Powers, Scott W

2013-12-01

Chronic pain in children is associated with significant negative impact on social, emotional, and school functioning. Previous studies on the impact of pain on children's functioning have primarily used mixed samples of pain conditions or single pain conditions (eg, headache and abdominal pain) with relatively small sample sizes. As a result, the similarities and differences in the impact of pain in subgroups of children with chronic pain have not been closely examined. To compare pain characteristics, quality of life, and emotional functioning among youth with pediatric chronic migraine (CM) and juvenile fibromyalgia (JFM). We combined data obtained during screening of patients for 2 relatively large intervention studies of youth (age range, 10 to 18 y) with CM (N=153) and JFM (N=151). Measures of pain intensity, quality of life (Pediatric Quality of Life; PedsQL, child and parent-proxy), depressive symptoms (Children's Depression Inventory), and anxiety symptoms (Adolescent Symptom Inventory-4-Anxiety subscale) were completed by youth and their parent. A multivariate analysis of covariance controlling for effects of age and sex was performed to examine differences in quality of life and emotional functioning between the CM and JFM groups. Youth with JFM had significantly higher anxiety and depressive symptoms, and lower quality of life in all domains. Among children with CM, overall functioning was higher but school functioning was a specific area of concern. Results indicate important differences in subgroups of pediatric pain patients and point to the need for more intensive multidisciplinary intervention for JFM patients.

Initial state q q g correlations as a background for the chiral magnetic effect in collision of small systems

DOE PAGES

Kovner, Alex; Lublinsky, Michael; Skokov, Vladimir

2017-11-13

Motivated by understanding the background to chiral magnetic effect in proton-nucleus collisions from first principles, we compute the three particle correlation in the projectile wave function. We extract the correlations between two quarks and one gluon in the framework of the color glass condensate. This is related to the same-charge correlation of the conventional observable for the chiral magnetic effect. We show that there are two different contributions to this correlation function. One contribution is rapidity-independent and as such can be identified with the pedestal; while the other displays rather strong rapidity dependence. The pedestal contribution and the rapidity-dependent contributionmore » at large rapidity separation between the two quarks result in the negative same charge correlations, while at small rapidity separation the second contribution changes sign. We argue that the computed initial state correlations might be partially responsible for the experimentally observed signal in proton-nucleus collisions.« less

Initial state q q g correlations as a background for the chiral magnetic effect in collision of small systems

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

Kovner, Alex; Lublinsky, Michael; Skokov, Vladimir

Motivated by understanding the background to chiral magnetic effect in proton-nucleus collisions from first principles, we compute the three particle correlation in the projectile wave function. We extract the correlations between two quarks and one gluon in the framework of the color glass condensate. This is related to the same-charge correlation of the conventional observable for the chiral magnetic effect. We show that there are two different contributions to this correlation function. One contribution is rapidity-independent and as such can be identified with the pedestal; while the other displays rather strong rapidity dependence. The pedestal contribution and the rapidity-dependent contributionmore » at large rapidity separation between the two quarks result in the negative same charge correlations, while at small rapidity separation the second contribution changes sign. We argue that the computed initial state correlations might be partially responsible for the experimentally observed signal in proton-nucleus collisions.« less

Enhanced functional connectivity properties of human brains during in-situ nature experience

PubMed Central

2016-01-01

In this study, we investigated the impacts of in-situ nature and urban exposure on human brain activities and their dynamics. We randomly assigned 32 healthy right-handed college students (mean age = 20.6 years, SD = 1.6; 16 males) to a 20 min in-situ sitting exposure in either a nature (n = 16) or urban environment (n = 16) and measured their Electroencephalography (EEG) signals. Analyses revealed that a brief in-situ restorative nature experience may induce more efficient and stronger brain connectivity with enhanced small-world properties compared with a stressful urban experience. The enhanced small-world properties were found to be correlated with “coherent” experience measured by Perceived Restorativeness Scale (PRS). Exposure to nature also induces stronger long-term correlated activity across different brain regions with a right lateralization. These findings may advance our understanding of the functional activities during in-situ environmental exposures and imply that a nature or nature-like environment may potentially benefit cognitive processes and mental well-being. PMID:27547533

Characterization of white poplar and eucalyptus after ionic liquid pretreatment as a function of biomass loading using X-ray diffraction and small angle neutron scattering

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

Yuan, Xueming; Duan, Yonghao; He, Lilin

A systematic study was done to understand interactions among biomass loading during ionic liquid (IL) pretreatment, biomass type and biomass structures. White poplar and eucalyptus samples were pretreated using 1-ethyl-3-methylimidazolium acetate (EmimOAc) at 110 °C for 3 h at biomass loadings of 5, 10, 15, 20 and 25 wt%. All of the samples were chemically characterized and tested for enzymatic hydrolysis. Physical structures including biomass crystallinity and porosity were measured by X-ray diffraction (XRD) and small angle neutron scattering (SANS), respectively. SANS detected pores of radii ranging from ~25 to 625 Å, enabling assessment of contributions of pores with different sizes to increased porositymore » after pretreatment. Contrasting dependences of sugar conversion on white poplar and eucalyptus as a function of biomass loading were observed and cellulose crystalline structure was found to play an important role.« less