Subtle differences in selective pressures applied on the envelope gene of HIV-1 in pregnant versus non-pregnant women.

PubMed

Ransy, Doris G; Lord, Etienne; Caty, Martine; Lapointe, Normand; Boucher, Marc; Diallo, Abdoulaye Baniré; Soudeyns, Hugo

2018-04-17

Pregnancy is associated with modulations of maternal immunity that contribute to foeto-maternal tolerance. To understand whether and how these alterations impact antiviral immunity, a detailed cross-sectional analysis of selective pressures exerted on HIV-1 envelope amino-acid sequences was performed in a group of pregnant (n = 32) and non-pregnant (n = 44) HIV-infected women in absence of treatment with antiretroviral therapy (ART). Independent of HIV-1 subtype, p-distance, dN and dS were all strongly correlated with one another but were not significantly different in pregnant as compared to non-pregnant patients. Differential levels of selective pressure applied on different Env subdomains displayed similar yet non-identical patterns between the two groups, with pressure applied on C1 being significantly lower in constant regions C1 and C2 than in V1, V2, V3 and C3. To draw a general picture of the selection applied on the envelope and compensate for inter-individual variations, we performed a binomial test on selection frequency data pooled from pregnant and non-pregnant women. This analysis uncovered 42 positions, present in both groups, exhibiting statistically-significant frequency of selection that invariably mapped to the surface of the Env protein, with the great majority located within epitopes recognized by Env-specific antibodies or sites associated with the development of cross-reactive neutralizing activity. The median frequency of occurrence of positive selection per site was significantly lower in pregnant versus non-pregnant women. Furthermore, examination of the distribution of positively selected sites using a hypergeometric test revealed that only 2 positions (D137 and S142) significantly differed between the 2 groups. Taken together, these result indicate that pregnancy is associated with subtle yet distinctive changes in selective pressures exerted on the HIV-1 Env protein that are compatible with transient modulations of maternal immunity. Copyright © 2018 Elsevier B.V. All rights reserved.

An exotic invasive plant selects for increased competitive tolerance, but not competitive suppression, in a native grass.

PubMed

Fletcher, Rebecca A; Callaway, Ragan M; Atwater, Daniel Z

2016-06-01

Exotic invasive plants can exert strong selective pressure for increased competitive ability in native plants. There are two fundamental components of competitive ability: suppression and tolerance, and the current paradigm that these components have equal influences on a species' overall competitive ability has been recently questioned. If these components do not have equal influences on overall ability, then selection on competitive tolerance and suppression may be disproportionate. We used naturally invaded communities to study the effects of selection caused by an invasive forb, Centaurea stoebe, on a native grass, Pseudoroegneria spicata. P. spicata plants were harvested from within dense C. stoebe patches and from nearby uninvaded areas, divided clonally into replicates, then transplanted into a common garden where they grew alone or competed with C. stoebe. We found that P. spicata plants collected from within C. stoebe patches were significantly more tolerant of competition with C. stoebe than P. spicata plants collected from uninvaded areas, but plants from inside invaded patches were not superior at suppressing C. stoebe. These results are consistent with the hypothesis that strong competitors may select for tolerance to competition more than for the ability to suppress neighbors. This has important implications for how native plant communities may respond to invasion over time, and how invasive and native species may ultimately coexist.

A model of directional selection applied to the evolution of drug resistance in HIV-1.

PubMed

Seoighe, Cathal; Ketwaroo, Farahnaz; Pillay, Visva; Scheffler, Konrad; Wood, Natasha; Duffet, Rodger; Zvelebil, Marketa; Martinson, Neil; McIntyre, James; Morris, Lynn; Hide, Winston

2007-04-01

Understanding how pathogens acquire resistance to drugs is important for the design of treatment strategies, particularly for rapidly evolving viruses such as HIV-1. Drug treatment can exert strong selective pressures and sites within targeted genes that confer resistance frequently evolve far more rapidly than the neutral rate. Rapid evolution at sites that confer resistance to drugs can be used to help elucidate the mechanisms of evolution of drug resistance and to discover or corroborate novel resistance mutations. We have implemented standard maximum likelihood methods that are used to detect diversifying selection and adapted them for use with serially sampled reverse transcriptase (RT) coding sequences isolated from a group of 300 HIV-1 subtype C-infected women before and after single-dose nevirapine (sdNVP) to prevent mother-to-child transmission. We have also extended the standard models of codon evolution for application to the detection of directional selection. Through simulation, we show that the directional selection model can provide a substantial improvement in sensitivity over models of diversifying selection. Five of the sites within the RT gene that are known to harbor mutations that confer resistance to nevirapine (NVP) strongly supported the directional selection model. There was no evidence that other mutations that are known to confer NVP resistance were selected in this cohort. The directional selection model, applied to serially sampled sequences, also had more power than the diversifying selection model to detect selection resulting from factors other than drug resistance. Because inference of selection from serial samples is unlikely to be adversely affected by recombination, the methods we describe may have general applicability to the analysis of positive selection affecting recombining coding sequences when serially sampled data are available.

Minocycline fails to exert antiepileptogenic effects in a rat status epilepticus model.

PubMed

Russmann, Vera; Goc, Joanna; Boes, Katharina; Ongerth, Tanja; Salvamoser, Josephine D; Siegl, Claudia; Potschka, Heidrun

2016-01-15

The tetracycline antibiotic minocycline can exert strong anti-inflammatory, antioxidant, and antiapoptotic effects. There is cumulating evidence that epileptogenic brain insults trigger neuroinflammation and anti-inflammatory concepts can modulate the process of epileptogenesis. Based on the mechanisms of action discussed for minocycline, the compound is of interest for intervention studies as it can prevent the polarization of microglia into a pro-inflammatory state. Here, we assessed the efficacy of sub-chronic minocycline administration initiated immediately following an electrically-induced status epilepticus in rats. The treatment did not affect the development of spontaneous seizures. However, minocycline attenuated behavioral long-term consequences of status epilepticus with a reduction in hyperactivity and hyperlocomotion. Furthermore, the compound limited the spatial learning deficits observed in the post-status epilepticus model. The typical status epilepticus-induced neuronal cell loss was evident in the hippocampus and the piriform cortex. Minocycline exposure selectively protected neurons in the piriform cortex and the hilus, but not in the hippocampal pyramidal layer. In conclusion, the data argue against an antiepileptogenic effect of minocycline in adult rats. However, the findings suggest a disease-modifying impact of the tetracycline affecting the development of behavioral co-morbidities, as well as long-term consequences on spatial learning. In addition, minocycline administration resulted in a selective neuroprotective effect. Although strong anti-inflammatory effects have been proposed for minocycline, we could not verify these effects in our experimental model. Considering the multitude of mechanisms claimed to contribute to minocycline's effects, it is of interest to further explore the exact mechanisms underlying the beneficial effects in future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Seed predators exert selection on the subindividual variation of seed size.

PubMed

Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

2014-07-01

Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Signal design and perception in Hypocnemis antbirds: evidence for convergent evolution via social selection.

PubMed

Tobias, Joseph A; Seddon, Nathalie

2009-12-01

Natural selection is known to produce convergent phenotypes through mimicry or ecological adaptation. It has also been proposed that social selection--i.e., selection exerted by social competition--may drive convergent evolution in signals mediating interspecific communication, yet this idea remains controversial. Here, we use color spectrophotometry, acoustic analyses, and playback experiments to assess the hypothesis of adaptive signal convergence in two competing nonsister taxa, Hypocnemis peruviana and H. subflava (Aves: Thamnophilidae). We show that the structure of territorial songs in males overlaps in sympatry, with some evidence of convergent character displacement. Conversely, nonterritorial vocal and visual signals in males are strikingly diagnostic, in line with 6.8% divergence in mtDNA sequences. The same pattern of variation applies to females. Finally, we show that songs in both sexes elicit strong territorial responses within and between species, whereas songs of a third, allopatric and more closely related species (H. striata) are structurally divergent and elicit weaker responses. Taken together, our results provide compelling evidence that social selection can act across species boundaries to drive convergent or parallel evolution in taxa competing for space and resources.

Immune Selection In Vitro Reveals Human Immunodeficiency Virus Type 1 Nef Sequence Motifs Important for Its Immune Evasion Function In Vivo

PubMed Central

Lee, Patricia; Ng, Hwee L.; Yang, Otto O.

2012-01-01

Human immunodeficiency virus type 1 (HIV-1) Nef downregulates major histocompatibility complex class I (MHC-I), impairing the clearance of infected cells by CD8+ cytotoxic T lymphocytes (CTLs). While sequence motifs mediating this function have been determined by in vitro mutagenesis studies of laboratory-adapted HIV-1 molecular clones, it is unclear whether the highly variable Nef sequences of primary isolates in vivo rely on the same sequence motifs. To address this issue, nef quasispecies from nine chronically HIV-1-infected persons were examined for sequence evolution and altered MHC-I downregulatory function under Gag-specific CTL immune pressure in vitro. This selection resulted in decreased nef diversity and strong purifying selection. Site-by-site analysis identified 13 codons undergoing purifying selection and 1 undergoing positive selection. Of the former, only 6 have been reported to have roles in Nef function, including 4 associated with MHC-I downregulation. Functional testing of naturally occurring in vivo polymorphisms at the 7 sites with no previously known functional role revealed 3 mutations (A84D, Y135F, and G140R) that ablated MHC-I downregulation and 3 (N52A, S169I, and V180E) that partially impaired MHC-I downregulation. Globally, the CTL pressure in vitro selected functional Nef from the in vivo quasispecies mixtures that predominately lacked MHC-I downregulatory function at the baseline. Overall, these data demonstrate that CTL pressure exerts a strong purifying selective pressure for MHC-I downregulation and identifies novel functional motifs present in Nef sequences in vivo. PMID:22553319

[Characteristics of non-exertional heat-related illness in Japan].

PubMed

Miyake, Yasufumi

2012-06-01

This report shows characteristics of non-exertional heat-related illness in Japan. The findings are similar to those of previous reports in heatwaves of Europe and The United States. Eldery people with pre-existing diseases, homeless, living alone, poverty are independent risk factors of heatstoke and are strongly associated with severity and mortality.

Selection for rapid embryo development correlates with embryo exposure to maternal androgens among passerine birds

USGS Publications Warehouse

Schwabl, H.; Palacios, M.G.; Martin, T.E.

2007-01-01

Greater offspring predation favors evolution of faster development among species. We hypothesized that greater offspring predation exerts selection on mothers to increase levels of anabolic androgens in egg yolks to achieve faster development. Here, we tested whether (1) concentrations of yolk androgens in passerine species were associated with offspring predation and (2) embryo and nestling development rates were associated with yolk androgen concentrations. We examined three androgens that increase in potency along the synthesis pathway: androstenedione (A4) to testosterone (T) to 5??- dihydrotestosterone (5??-DHT). Concentrations of none of these steroids were related to clutch size; only A4 was allometrically related to egg volume. Species that experience greater predation showed higher yolk concentrations of T and 5??-DHT. Higher concentrations of T and particularly 5??-DHT were strongly correlated with faster development during the embryo period and less so during the nestling period. Development rates were most strongly correlated with 5??-DHT, suggesting that potency increases along the androgen synthesis pathway and that effects are mediated by the androgen receptor pathway. These results are consistent with the hypothesis that selection for faster development by time-dependent offspring mortality may be achieved epigenetically by varying embryo exposure to maternal anabolic steroids. ?? 2007 by The University of Chicago. All rights reserved.

Selection dynamic of Escherichia coli host in M13 combinatorial peptide phage display libraries.

PubMed

Zanconato, Stefano; Minervini, Giovanni; Poli, Irene; De Lucrezia, Davide

2011-01-01

Phage display relies on an iterative cycle of selection and amplification of random combinatorial libraries to enrich the initial population of those peptides that satisfy a priori chosen criteria. The effectiveness of any phage display protocol depends directly on library amino acid sequence diversity and the strength of the selection procedure. In this study we monitored the dynamics of the selective pressure exerted by the host organism on a random peptide library in the absence of any additional selection pressure. The results indicate that sequence censorship exerted by Escherichia coli dramatically reduces library diversity and can significantly impair phage display effectiveness.

Lewis base catalyzed aldol additions of chiral trichlorosilyl enolates and silyl enol ethers.

PubMed

Denmark, Scott E; Fujimori, Shinji; Pham, Son M

2005-12-23

[structures: see text] The consequences of double diastereodifferentiation in chiral Lewis base catalyzed aldol additions using chiral enoxysilanes derived from lactate, 3-hydroxyisobutyrate, and 3-hydroxybutyrate have been investigated. Trichlorosilyl enolates derived from the chiral methyl and ethyl ketones were subjected to aldolization in the presence of phosphoramides, and the intrinsic selectivity of these enolates and the external stereoinduction from chiral catalyst were studied. In the reactions with the lactate derived enolate, the strong internal stereoinduction dominated the stereochemical outcome of the aldol addition. For the 3-hydroxyisobutyrate- and 3-hydroxybutyrate derived enolates, the catalyst-controlled diastereoselectivities were observed, and the resident stereogenic centers exerted marginal influence. The corresponding trimethylsilyl enol ethers were employed in SiCl4/bisphosphoramide catalyzed aldol additions, and the effect of double diastereodifferentiation was also investigated. The overall diastereoselection of the process was again controlled by the strong external influence of the catalyst.

Microclimate and propagule availability are equally important for rehabilitation of dryland N-fixing lichens

USGS Publications Warehouse

Bowker, M.A.; Belnap, J.; Davidson, D.W.

2010-01-01

In some arid regions, rehabilitation of whole system N-fixation may be strongly facilitated by the recovery of populations of the lichen genus Collema. Identification of the limits to recovery of Collema in apparently suitable habitat should inform selection of rehabilitation techniques. We simultaneously tested the relative importance of three hypothetical limits to Collema recovery: active erosion, resource limitation, and propagule scarcity. We found that in our experimental system, active erosion had no effect on short-term establishment of Collema, whereas propagule addition did enhance recovery and microhabitat (a resource availability gradient) also exerted a strong influence. It is possible that attempts to improve N cycling via re-establishment of Collema might be best served by developing economical means of simulating moister, cooler microhabitats, e.g., sloping soil or creating partial shade, which would favor the establishment of naturally dispersed propagules, rather than introducing propagules. ?? 2009 Society for Ecological Restoration International.

Effects of ginger and its pungent constituents on transient receptor potential channels.

PubMed

Kim, Young-Soo; Hong, Chan Sik; Lee, Sang Weon; Nam, Joo Hyun; Kim, Byung Joo

2016-12-01

Ginger extract is used as an analeptic in herbal medicine and has been reported to exert antioxidant effects. Transient receptor potential (TRP) canonical 5 (TRPC5), TRP cation channel, subfamily M, member 7 (TRPM7; melastatin 7), and TRP cation channel, subfamily A, member 1 (TRPA1; ankyrin 1) are non-selective cation channels that are modulated by reactive oxygen/nitrogen species (ROS/RNS) and subsequently control various cellular processes. The aim of this study was to evaluate whether ginger and its pungent constituents modulate these channels and exert antioxidant effects. It was found that TRPC5 and TRPA1 currents were modulated by ginger extract and by its pungent constituents, [6]-gingerol, zingerone and [6]-shogaol. In particular, [6]-shogaol markedly and dose-dependently inhibited TRPC5 currents with an IC50 of value of ~18.3 µM. Furthermore, the strong dose-dependent activation of TRPA1 currents by [6]-shogaol was abolished by A‑967079 (a selective TRPA1 inhibitor). However, ginger extract and its pungent constituents had no effect on TRPM7 currents. These results suggest the antioxidant effects of ginger extract and its pungent constituents are mediated through TRPC5 and TRPA1, and that [6]-shogaol is predominantly responsible for the regulation of TRPC5 and TRPA1 currents by ginger extract.

Analysis of the independent power of age-related, anthropometric and mechanical factors as determinants of the structure of radius and tibia in normal adults. A pQCT study.

PubMed

Reina, P; Cointry, G R; Nocciolino, L; Feldman, S; Ferretti, J L; Rittweger, J; Capozza, R F

2015-03-01

To compare the independent influence of mechanical and non-mechanical factors on bone features, multiple regression analyses were performed between pQCT indicators of radius and tibia bone mass, mineralization, design and strength as determined variables, and age or time since menopause (TMP), body mass, bone length and regional muscles' areas as selected determinant factors, in Caucasian, physically active, untrained healthy men and pre- and post-menopausal women. In men and pre-menopausal women, the strongest influences were exerted by muscle area on radial features and by both muscle area and bone length on the tibia. Only for women, was body mass a significant factor for tibia traits. In men and pre-menopausal women, mass/design/strength indicators depended more strongly on the selected determinants than the cortical vBMD did (p<0.01-0.001 vs n.s.), regardless of age. However, TMP was an additional factor for both bones (p<0.01-0.001). The selected mechanical factors (muscle size, bone lengths) were more relevant than age/TMP or body weight to the development of allometrically-related bone properties (mass/design/strength), yet not to bone tissue 'quality' (cortical vBMD), suggesting a determinant, rather than determined role for cortical stiffness. While the mechanical impacts of muscles and bone levers on bone structure were comparable in men and pre-menopausal women, TMP exerted a stronger impact than allometric or mechanical factors on bone properties, including cortical vBMD.

Conciliatory gestures promote forgiveness and reduce anger in humans.

PubMed

McCullough, Michael E; Pedersen, Eric J; Tabak, Benjamin A; Carter, Evan C

2014-07-29

Conflict is an inevitable component of social life, and natural selection has exerted strong effects on many organisms to facilitate victory in conflict and to deter conspecifics from imposing harms upon them. Like many species, humans likely possess cognitive systems whose function is to motivate revenge as a means of deterring individuals who have harmed them from harming them again in the future. However, many social relationships often retain value even after conflicts have occurred between interactants, so natural selection has very likely also endowed humans with cognitive systems whose function is to motivate reconciliation with transgressors whom they perceive as valuable and nonthreatening, notwithstanding their harmful prior actions. In a longitudinal study with 337 participants who had recently been harmed by a relationship partner, we found that conciliatory gestures (e.g., apologies, offers of compensation) were associated with increases in victims' perceptions of their transgressors' relationship value and reductions in perceptions of their transgressors' exploitation risk. In addition, conciliatory gestures appeared to accelerate forgiveness and reduce reactive anger via their intermediate effects on relationship value and exploitation risk. These results strongly suggest that conciliatory gestures facilitate forgiveness and reduce anger by modifying victims' perceptions of their transgressors' value as relationship partners and likelihood of recidivism.

Cerium oxide nanoparticles, combining antioxidant and UV shielding properties, prevent UV-induced cell damage and mutagenesis

NASA Astrophysics Data System (ADS)

Caputo, Fanny; de Nicola, Milena; Sienkiewicz, Andrzej; Giovanetti, Anna; Bejarano, Ignacio; Licoccia, Silvia; Traversa, Enrico; Ghibelli, Lina

2015-09-01

Efficient inorganic UV shields, mostly based on refracting TiO2 particles, have dramatically changed the sun exposure habits. Unfortunately, health concerns have emerged from the pro-oxidant photocatalytic effect of UV-irradiated TiO2, which mediates toxic effects on cells. Therefore, improvements in cosmetic solar shield technology are a strong priority. CeO2 nanoparticles are not only UV refractors but also potent biological antioxidants due to the surface 3+/4+ valency switch, which confers anti-inflammatory, anti-ageing and therapeutic properties. Herein, UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of CeO2vs. TiO2 nanoparticles on reporter cells. TiO2 irradiated with UV (especially UVA) exerted strong photocatalytic effects, superimposing their pro-oxidant, cell-damaging and mutagenic action when induced by UV, thereby worsening the UV toxicity. On the contrary, irradiated CeO2 nanoparticles, via their Ce3+/Ce4+ redox couple, exerted impressive protection on UV-treated cells, by buffering oxidation, preserving viability and proliferation, reducing DNA damage and accelerating repair; strikingly, they almost eliminated mutagenesis, thus acting as an important tool to prevent skin cancer. Interestingly, CeO2 nanoparticles also protect cells from the damage induced by irradiated TiO2, suggesting that these two particles may also complement their effects in solar lotions. CeO2 nanoparticles, which intrinsically couple UV shielding with biological and genetic protection, appear to be ideal candidates for next-generation sun shields.

Convergent Evolution Associated with Habitat Decouples Phenotype from Phylogeny in a Clade of Lizards

PubMed Central

Edwards, Shelley; Vanhooydonck, Bieke; Herrel, Anthony; Measey, G. John; Tolley, Krystal A.

2012-01-01

Convergent evolution can explain similarity in morphology between species, due to selection on a fitness-enhancing phenotype in response to local environmental conditions. As selective pressures on body morphology may be strong, these have confounded our understanding of the evolutionary relationships between species. Within the speciose African radiation of lacertid lizards (Eremiadini), some species occupy a narrow habitat range (e.g. open habitat, cluttered habitat, strictly rupicolous, or strictly psammophilic), which may exert strong selective pressures on lizard body morphology. Here we show that the overall body plan is unrelated to shared ancestry in the African radiation of Eremiadini, but is instead coupled to habitat use. Comprehensive Bayesian and likelihood phylogenies using multiple representatives from all genera (2 nuclear, 2 mitochondrial markers) show that morphologically convergent species thought to represent sister taxa within the same genus are distantly related evolutionary lineages (Ichnotropis squamulosa and Ichnotropis spp.; Australolacerta rupicola and A. australis). Hierarchical clustering and multivariate analysis of morphological characters suggest that body, and head, width and height (stockiness), all of which are ecologically relevant with respect to movement through habitat, are similar between the genetically distant species. Our data show that convergence in morphology, due to adaptation to similar environments, has confounded the assignment of species leading to misidentification of the taxonomic position of I. squamulosa and the Australolacerta species. PMID:23251601

Leaf polyphenol profile and SSR-based fingerprinting of new segregant Cynara cardunculus genotypes

PubMed Central

Pandino, Gaetano; Lombardo, Sara; Moglia, Andrea; Portis, Ezio; Lanteri, Sergio; Mauromicale, Giovanni

2015-01-01

The dietary value of many plant polyphenols lies in the protection given against degenerative pathologies. Their in planta role is associated with the host's defense response against biotic and abiotic stress. The polyphenol content of a given plant tissue is strongly influenced by the growing environment, but is also genetically determined. Plants belonging to the Cynara cardunculus species (globe artichoke and the cultivated and wild cardoon) accumulate substantial quantities of polyphenols mainly mono and di-caffeoylquinic acid (CQA) in their foliage. Transgressive segregation for CQA content in an F1 population bred from a cross between a globe artichoke and a cultivated cardoon led to the selection of eight segregants which accumulated more CQA in their leaves than did those of either of their parental genotypes. The selections were grown over two seasons to assess their polyphenol profile (CQAs, apigenin and luteolin derivatives and narirutin), and were also fingerprinted using a set of 217 microsatellite markers. The growing environment exerted a strong effect on polyphenol content, but two of the selections were able to accumulate up to an order of magnitude more CQA than either parent in both growing seasons. Since the species is readily vegetatively propagable, such genotypes can be straightforwardly exploited as a source of pharmaceutically valuable compounds, while their SSR-based fingerprinting will allow the genetic identity of clonally propagated material to be easily verified. PMID:25653660

Promising Diabetes Therapy Based on the Molecular Mechanism for Glucose Toxicity: Usefulness of SGLT2 Inhibitors as well as Incretin-Related Drugs.

PubMed

Kaneto, Hideaki; Obata, Atsushi; Shimoda, Masashi; Kimura, Tomohiko; Hirukawa, Hidenori; Okauchi, Seizo; Matsuoka, Taka-Aki; Kaku, Kohei

2016-01-01

Pancreatic β-cell dysfunction and insulin resistance are the main characteristics of type 2 diabetes. Chronic exposure of β-cells to hyperglycemia leads to the deterioration of β-cell function. Such phenomena are well known as pancreatic β-cell glucose toxicity. MafA, a strong transactivator of insulin gene, is particularly important for the maintenance of mature β-cell function, but its expression level is significantly reduced under diabetic conditions which is likely associated with β-cell failure. Reduction of incretin receptor expression level in β-cells in diabetes is also likely associated with β-cell failure. On the other hand, incretin-related drugs and sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising diabetes therapy based on the mechanism for pancreatic β-cell glucose toxicity. Indeed, it was shown that incretin-related drugs exerted protective effects on β-cells through the augmentation of IRS-2 expression especially in the presence of pioglitazone. It was also shown that incretin-related drug and/or pioglitazone exerted more protective effects on β-cells at the early stage of diabetes compared to the advanced stage. SGLT2 inhibitors, new hypoglycemic agents, also exert beneficial effects for the protection of pancreatic β-cells as well as for the reduction of insulin resistance in various insulin target tissues. Taken together, it is important to select appropriate therapy based on the molecular mechanism for glucose toxicity.

Self-selected music-induced reduction of perceived exertion during moderate-intensity exercise does not interfere with post-exercise improvements in inhibitory control.

PubMed

Tanaka, Daichi; Tsukamoto, Hayato; Suga, Tadashi; Takenaka, Saki; Hamaoka, Takafumi; Hashimoto, Takeshi; Isaka, Tadao

2018-05-26

Acute aerobic exercise improves inhibitory control (IC). This improvement is often associated with increases in perceived exertion during exercise. However, listening to music during aerobic exercise mitigates an exercise-induced increase in perceived exertion. Thus, it is hypothesized that such effects of music may interfere with exercise-induced improvements in IC. To test this hypothesis, we examined the effect of music on post-exercise IC improvements that were induced by moderate-intensity exercise. Fifteen healthy young men performed cycle ergometer exercise with music or non-music. The exercise was performed using a moderate-intensity of 60% of VO 2 peak for 30 min. The music condition was performed while listening to self-selected music. The non-music condition involved no music. To evaluate IC, the Stroop task was administered before exercise, immediately after exercise, and during the 30-min post-exercise recovery period. The rate of perceived exertion immediately before moderate-intensity exercise completed was significantly lower in music condition than in non-music condition. The IC significantly improved immediately after exercise and during the post-exercise recovery period compared to before exercise in both music and non-music conditions. The post-exercise IC improvements did not significantly differ between the two conditions. These findings indicate that self-selected music-induced mitigation of the increase in perceived exertion during moderate-intensity exercise dose not interfere with exercise-induced improvements in IC. Therefore, we suggest that listening to music may be a beneficial strategy in mitigating the increase in perceived exertion during aerobic exercise without decreasing the positive effects on IC. Copyright © 2018 Elsevier Inc. All rights reserved.

Canopy closure exerts weak controls on understory dynamics: a 30-year study of overstory-understory interactions

Treesearch

C.B. Halpern; J.A. Lutz

2013-01-01

Stem exclusion and understory reinitiation are commonly described, but poorly understood, stages of forest development. It is assumed that overstory trees exert strong controls on understory herbs and shrubs during the transition from open- to closed-canopy forests, but long-term observations of this process are rare. We use long-term data from 188 plots to explore...

Bilingualism and Creativity: Benefits in Convergent Thinking Come with Losses in Divergent Thinking

PubMed Central

Hommel, Bernhard; Colzato, Lorenza S.; Fischer, Rico; Christoffels, Ingrid K.

2011-01-01

Bilingualism is commonly assumed to improve creativity but the mechanisms underlying creative acts, and the way these mechanisms are affected by bilingualism, are not very well understood. We hypothesize that learning to master multiple languages drives individuals toward a relatively focused cognitive-control state that exerts strong top-down impact on information processing and creates strong local competition for selection between cognitive codes. Considering the control requirements posed by creativity tasks tapping into convergent and divergent thinking, this predicts that high-proficient bilinguals should outperform low-proficient bilinguals in convergent thinking, while low-proficient bilinguals might be better in divergent thinking. Comparing low- and high-proficient bilinguals on convergent-thinking and divergent-thinking tasks indeed showed a high-proficient bilingual advantage for convergent thinking but a low-proficient bilingual advantage for fluency in divergent thinking. These findings suggest that bilingualism should not be related to “creativity” as a unitary concept but, rather, to the specific processes and mechanisms that underlie creativity. PMID:22084634

Nonneutral GC3 and retroelement codon mimicry in Phytophthora.

PubMed

Jiang, Rays H Y; Govers, Francine

2006-10-01

Phytophthora is a genus entirely comprised of destructive plant pathogens. It belongs to the Stramenopila, a unique branch of eukaryotes, phylogenetically distinct from plants, animals, or fungi. Phytophthora genes show a strong preference for usage of codons ending with G or C (high GC3). The presence of high GC3 in genes can be utilized to differentiate coding regions from noncoding regions in the genome. We found that both selective pressure and mutation bias drive codon bias in Phytophthora. Indicative for selection pressure is the higher GC3 value of highly expressed genes in different Phytophthora species. Lineage specific GC increase of noncoding regions is reminiscent of whole-genome mutation bias, whereas the elevated Phytophthora GC3 is primarily a result of translation efficiency-driven selection. Heterogeneous retrotransposons exist in Phytophthora genomes and many of them vary in their GC content. Interestingly, the most widespread groups of retroelements in Phytophthora show high GC3 and a codon bias that is similar to host genes. Apparently, selection pressure has been exerted on the retroelement's codon usage, and such mimicry of host codon bias might be beneficial for the propagation of retrotransposons.

Swimming against the current: genetic vaccination against Trypanosoma cruzi infection in mice.

PubMed

Rodrigues, Mauricio M; de Alencar, Bruna C; Claser, Carla; Tzelepis, Fanny; Silveira, Eduardo L; Haolla, Filipe A; Dominguez, Mariana R; Vasconcelos, José Ronnie

2009-07-01

Vaccines have had an unquestionable impact on public health during the last century. The most likely reason for the success of vaccines is the robust protective properties of specific antibodies. However, antibodies exert a strong selective pressure and many microorganisms, such as the obligatory intracellular parasite Trypanosoma cruzi, have been selected to survive in their presence. Although the host develops a strong immune response to T. cruzi, they do not clear the infection and instead progress to the chronic phase of the disease. Parasite persistence during the chronic phase of infection is now considered the main factor contributing to the chronic symptoms of the disease. Based on this finding, containment of parasite growth and survival may be one method to avoid the immunopathology of the chronic phase. In this context, vaccinologists have looked over the past 20 years for other immune effector mechanisms that could eliminate these antibody-resistant pathogens. We and others have tested the hypothesis that non-antibody-mediated cellular immune responses (CD4+ Th1 and CD8+ Tc1 cells) to specific parasite antigens/genes expressed by T. cruzi could indeed be used for the purpose of vaccination. This hypothesis was confirmed in different mouse models, indicating a possible path for vaccine development.

Bottom-up vs. top-down effects on terrestrial insect herbivores: a meta-analysis.

PubMed

Vidal, Mayra C; Murphy, Shannon M

2018-01-01

Primary consumers are under strong selection from resource ('bottom-up') and consumer ('top-down') controls, but the relative importance of these selective forces is unknown. We performed a meta-analysis to compare the strength of top-down and bottom-up forces on consumer fitness, considering multiple predictors that can modulate these effects: diet breadth, feeding guild, habitat/environment, type of bottom-up effects, type of top-down effects and how consumer fitness effects are measured. We focused our analyses on the most diverse group of primary consumers, herbivorous insects, and found that in general top-down forces were stronger than bottom-up forces. Notably, chewing, sucking and gall-making herbivores were more affected by top-down than bottom-up forces, top-down forces were stronger than bottom-up in both natural and controlled (cultivated) environments, and parasitoids and predators had equally strong top-down effects on insect herbivores. Future studies should broaden the scope of focal consumers, particularly in understudied terrestrial systems, guilds, taxonomic groups and top-down controls (e.g. pathogens), and test for more complex indirect community interactions. Our results demonstrate the surprising strength of forces exerted by natural enemies on herbivorous insects, and thus the necessity of using a tri-trophic approach when studying insect-plant interactions. © 2017 John Wiley & Sons Ltd/CNRS.

Clines in quantitative traits: The role of migration patterns and selection scenarios

PubMed Central

Geroldinger, Ludwig; Bürger, Reinhard

2015-01-01

The existence, uniqueness, and shape of clines in a quantitative trait under selection toward a spatially varying optimum is studied. The focus is on deterministic diploid two-locus n-deme models subject to various migration patterns and selection scenarios. Migration patterns may exhibit isolation by distance, as in the stepping-stone model, or random dispersal, as in the island model. The phenotypic optimum may change abruptly in a single environmental step, more gradually, or not at all. Symmetry assumptions are imposed on phenotypic optima and migration rates. We study clines in the mean, variance, and linkage disequilibrium (LD). Clines result from polymorphic equilibria. The possible equilibrium configurations are determined as functions of the migration rate. Whereas for weak migration, many polymorphic equilibria may be simultaneously stable, their number decreases with increasing migration rate. Also for intermediate migration rates polymorphic equilibria are in general not unique, however, for loci of equal effects the corresponding clines in the mean, variance, and LD are unique. For sufficiently strong migration, no polymorphism is maintained. Both migration pattern and selection scenario exert strong influence on the existence and shape of clines. The results for discrete demes are compared with those from models in which space varies continuously and dispersal is modeled by diffusion. Comparisons with previous studies, which investigated clines under neutrality or under linkage equilibrium, are performed. If there is no long-distance migration, the environment does not change abruptly, and linkage is not very tight, populations are almost everywhere close to linkage equilibrium. PMID:25446959

A large new subset of TRIM genes highly diversified by duplication and positive selection in teleost fish

PubMed Central

van der Aa, Lieke M; Levraud, Jean-Pierre; Yahmi, Malika; Lauret, Emilie; Briolat, Valérie; Herbomel, Philippe; Benmansour, Abdenour; Boudinot, Pierre

2009-01-01

Background In mammals, the members of the tripartite motif (TRIM) protein family are involved in various cellular processes including innate immunity against viral infection. Viruses exert strong selective pressures on the defense system. Accordingly, antiviral TRIMs have diversified highly through gene expansion, positive selection and alternative splicing. Characterizing immune TRIMs in other vertebrates may enlighten their complex evolution. Results We describe here a large new subfamily of TRIMs in teleosts, called finTRIMs, identified in rainbow trout as virus-induced transcripts. FinTRIMs are formed of nearly identical RING/B-box regions and C-termini of variable length; the long variants include a B30.2 domain. The zebrafish genome harbors a striking diversity of finTRIMs, with 84 genes distributed in clusters on different chromosomes. A phylogenetic analysis revealed different subsets suggesting lineage-specific diversification events. Accordingly, the number of fintrim genes varies greatly among fish species. Conserved syntenies were observed only for the oldest fintrims. The closest mammalian relatives are trim16 and trim25, but they are not true orthologs. The B30.2 domain of zebrafish finTRIMs evolved under strong positive selection. The positions under positive selection are remarkably congruent in finTRIMs and in mammalian antiviral TRIM5α, concentrated within a viral recognition motif in mammals. The B30.2 domains most closely related to finTRIM are found among NOD-like receptors (NLR), indicating that the evolution of TRIMs and NLRs was intertwined by exon shuffling. Conclusion The diversity, evolution, and features of finTRIMs suggest an important role in fish innate immunity; this would make them the first TRIMs involved in immunity identified outside mammals. PMID:19196451

Influenza virus drug resistance: a time-sampled population genetics perspective.

PubMed

Foll, Matthieu; Poh, Yu-Ping; Renzette, Nicholas; Ferrer-Admetlla, Anna; Bank, Claudia; Shim, Hyunjin; Malaspinas, Anna-Sapfo; Ewing, Gregory; Liu, Ping; Wegmann, Daniel; Caffrey, Daniel R; Zeldovich, Konstantin B; Bolon, Daniel N; Wang, Jennifer P; Kowalik, Timothy F; Schiffer, Celia A; Finberg, Robert W; Jensen, Jeffrey D

2014-02-01

The challenge of distinguishing genetic drift from selection remains a central focus of population genetics. Time-sampled data may provide a powerful tool for distinguishing these processes, and we here propose approximate Bayesian, maximum likelihood, and analytical methods for the inference of demography and selection from time course data. Utilizing these novel statistical and computational tools, we evaluate whole-genome datasets of an influenza A H1N1 strain in the presence and absence of oseltamivir (an inhibitor of neuraminidase) collected at thirteen time points. Results reveal a striking consistency amongst the three estimation procedures developed, showing strongly increased selection pressure in the presence of drug treatment. Importantly, these approaches re-identify the known oseltamivir resistance site, successfully validating the approaches used. Enticingly, a number of previously unknown variants have also been identified as being positively selected. Results are interpreted in the light of Fisher's Geometric Model, allowing for a quantification of the increased distance to optimum exerted by the presence of drug, and theoretical predictions regarding the distribution of beneficial fitness effects of contending mutations are empirically tested. Further, given the fit to expectations of the Geometric Model, results suggest the ability to predict certain aspects of viral evolution in response to changing host environments and novel selective pressures.

Nonconsumptive predator-driven mortality causes natural selection on prey.

PubMed

Siepielski, Adam M; Wang, Jason; Prince, Garrett

2014-03-01

Predators frequently exert natural selection through differential consumption of their prey. However, predators may also cause prey mortality through nonconsumptive effects, which could cause selection if different prey phenotypes are differentially susceptible to this nonconsumptive mortality. Here we present an experimental test of this hypothesis, which reveals that nonconsumptive mortality imposed by predatory dragonflies causes selection on their damselfly prey favoring increased activity levels. These results are consistent with other studies of predator-driven selection, however, they reveal that consumption alone is not the only mechanism by which predators can exert selection on prey. Uncovering this mechanism also suggests that prey defensive traits may represent adaptations to not only avoid being consumed, but also for dealing with other sources of mortality caused by predators. Demonstrating selection through both consumptive and nonconsumptive predator mortality provides us with insight into the diverse effects of predators as an evolutionary force. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Changes in the selection differential exerted on a marine snail during the ontogeny of a predatory shore crab.

PubMed

Pakes, D; Boulding, E G

2010-08-01

Empirical estimates of selection gradients caused by predators are common, yet no one has quantified how these estimates vary with predator ontogeny. We used logistic regression to investigate how selection on gastropod shell thickness changed with predator size. Only small and medium purple shore crabs (Hemigrapsus nudus) exerted a linear selection gradient for increased shell-thickness within a single population of the intertidal snail (Littorina subrotundata). The shape of the fitness function for shell thickness was confirmed to be linear for small and medium crabs but was humped for large male crabs, suggesting no directional selection. A second experiment using two prey species to amplify shell thickness differences established that the selection differential on adult snails decreased linearly as crab size increased. We observed differences in size distribution and sex ratios among three natural shore crab populations that may cause spatial and temporal variation in predator-mediated selection on local snail populations.

Prey from the eyes of predators: Color discriminability of aposematic and mimetic butterflies from an avian visual perspective.

PubMed

Su, Shiyu; Lim, Matthew; Kunte, Krushnamegh

2015-11-01

Predation exerts strong selection on mimetic butterfly wing color patterns, which also serve other functions such as sexual selection. Therefore, specific selection pressures may affect the sexes and signal components differentially. We tested three predictions about the evolution of mimetic resemblance by comparing wing coloration of aposematic butterflies and their Batesian mimics: (a) females gain greater mimetic advantage than males and therefore are better mimics, (b) due to intersexual genetic correlations, sexually monomorphic mimics are better mimics than female-limited mimics, and (c) mimetic resemblance is better on the dorsal wing surface that is visible to predators in flight. Using a physiological model of avian color vision, we quantified mimetic resemblance from predators' perspective, which showed that female butterflies were better mimics than males. Mimetic resemblance in female-limited mimics was comparable to that in sexually monomorphic mimics, suggesting that intersexual genetic correlations did not constrain adaptive response to selection for female-limited mimicry. Mimetic resemblance on the ventral wing surface was better than that on the dorsal wing surface, implying stronger natural and sexual selection on ventral and dorsal surfaces, respectively. These results suggest that mimetic resemblance in butterfly mimicry rings has evolved under various selective pressures acting in a sex- and wing surface-specific manner. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Temporal kinetics of prefrontal modulation of the extrastriate cortex during visual attention.

PubMed

Yago, Elena; Duarte, Audrey; Wong, Ting; Barceló, Francisco; Knight, Robert T

2004-12-01

Single-unit, event-related potential (ERP), and neuroimaging studies have implicated the prefrontal cortex (PFC) in top-down control of attention and working memory. We conducted an experiment in patients with unilateral PFC damage (n = 8) to assess the temporal kinetics of PFC-extrastriate interactions during visual attention. Subjects alternated attention between the left and the right hemifields in successive runs while they detected target stimuli embedded in streams of repetitive task-irrelevant stimuli (standards). The design enabled us to examine tonic (spatial selection) and phasic (feature selection) PFC-extrastriate interactions. PFC damage impaired performance in the visual field contralateral to lesions, as manifested by both larger reaction times and error rates. Assessment of the extrastriate P1 ERP revealed that the PFC exerts a tonic (spatial selection) excitatory input to the ipsilateral extrastriate cortex as early as 100 msec post stimulus delivery. The PFC exerts a second phasic (feature selection) excitatory extrastriate modulation from 180 to 300 msec, as evidenced by reductions in selection negativity after damage. Finally, reductions of the N2 ERP to target stimuli supports the notion that the PFC exerts a third phasic (target selection) signal necessary for successful template matching during postselection analysis of target features. The results provide electrophysiological evidence of three distinct tonic and phasic PFC inputs to the extrastriate cortex in the initial few hundred milliseconds of stimulus processing. Damage to this network appears to underlie the pervasive deficits in attention observed in patients with prefrontal lesions.

Spatial variation in selection on corolla shape in a generalist plant is promoted by the preference patterns of its local pollinators.

PubMed

Gómez, José M; Bosch, Jordi; Perfectti, Francisco; Fernández, J D; Abdelaziz, Mohamed; Camacho, J P M

2008-10-07

An adaptive role of corolla shape has been often asserted without an empirical demonstration of how natural selection acts on this trait. In generalist plants, in which flowers are visited by diverse pollinator fauna that commonly vary spatially, detecting pollinator-mediated selection on corolla shape is even more difficult. In this study, we explore the mechanisms promoting selection on corolla shape in the generalist crucifer Erysimum mediohispanicum Polatschek (Brassicaceae). We found that the main pollinators of E. mediohispanicum (large bees, small bees and bee flies) discriminate between different corolla shapes when offered artificial flowers without reward. Importantly, different pollinators prefer different shapes: bees prefer flowers with narrow petals, whereas bee flies prefer flowers with rounded overlapping petals. We also found that flowers with narrow petals (those preferred by bees) produce both more pollen and nectar than those with rounded petals. Finally, different plant populations were visited by different faunas. As a result, we found spatial variation in the selection acting on corolla shape. Selection favoured flowers with narrow petals in the populations where large or small bees are the most abundant pollinator groups. Our study suggests that pollinators, by preferring flowers with high reward, exert strong selection on the E. mediohispanicum corolla shape. The geographical variation in the pollinator-mediated selection on E. mediohispanicum corolla shape suggests that phenotypic evolution and diversification can occur in this complex floral trait even without specialization.

Thrombin like activity of Asclepias curassavica L. latex: action of cysteine proteases.

PubMed

Shivaprasad, H V; Rajesh, R; Nanda, B L; Dharmappa, K K; Vishwanath, B S

2009-05-04

To validate the scientific basis of plant latex to stop bleeding on fresh cuts. Cysteine protease(s) from Asclepias curassavica (Asclepiadaceae) plant latex was assessed for pro-coagulant and thrombin like activities. A waxy material from the latex of Asclepias curassavica latex was removed by freezing and thawing. The resulted latex enzyme fraction was assayed for proteolytic activity using denatured casein as substrate. Its coagulant activity and thrombin like activity were determined using citrated plasma and pure fibrinogen, respectively. Inhibition studies were performed using specific protease inhibitors to know the type of protease. The latex enzyme fraction exhibited strong proteolytic activity when compared to trypsin and exerted pro-coagulant action by reducing plasma clotting time from 195 to 58 s whereas trypsin reduced clotting time marginally from 195 to 155 s. The pro-coagulant activity of this enzyme fraction was exerted by selectively hydrolyzing A alpha and B beta subunits of fibrinogen to form fibrin clot when pure fibrinogen was used as substrate as assessed by fibrinogen-agarose plate method and fibrinogen polymerization assay. Trypsin failed to induce any fibrin clot under similar conditions. The electrophoretic pattern of latex enzyme fraction-induced fibrin clot was very much similar to that of thrombin-induced fibrin clot and mimic thrombin like action. The proteolytic activity including thrombin like activity of Asclepias curassavica latex enzyme fraction was completely inhibited by iodoaceticacid (IAA). Cysteine proteases from Asclepias curassavica latex exhibited strong pro-coagulant action and were found to be specific in its action (Thrombin like). This could be the basis for the use of plant latex in pharmacological applications that justify their use as folk medicine.

Predation and the evolution of complex oviposition behaviour in Amazon rainforest frogs.

PubMed

Magnusson, William E; Hero, Jean-Marc

1991-05-01

Terrestrial oviposition with free-living aquatic larvae is a common reproductive mode used by amphibians within the central Amazonian rainforest. We investigated the factors presently associated with diversity of microhabitats (waterbodies) that may be maintaining the diversity of reproductive modes. In particular, desiccation, predation by fish, competition with other anurans and water quality were examined in 11 waterbodies as possible forces leading to the evolution of terrestrial oviposition. Predation experiments demonstrated that fish generally do not eat anuran eggs, and that predacious tadpoles and dytiscid beetle larvae are voracious predators of anuran eggs. The percentage of species with terrestrial oviposition was only weakly correlated with the occurrence of pond drying, pH and oxygen concentration, suggesting that anurans in this tropical community are able to use the range of water quality available for egg development. There was a tendency for terrestrial oviposition to be associated with the number of species of tadpoles using the waterbody, but we consider this to be spurious as there was no obvious competitive mechanism that could result in this relationship. The percentage of species with terrestrial oviposition was significantly positively related to our index of egg predation pressure, and negatively related to our index of fish biomass. Egg predation pressure was also negatively related to the index of fish biomass. These results allow us to discount as improbable the hypothesis that predation by fish on anuran eggs was an important selective pressure leading to terrestrial oviposition in this community. The strong positive relationship between terrestrial oviposition and our index of egg predation pressure indicates that these predators have exerted, and are exerting, a significant selective pressure for terrestrial oviposition. The strong negative relationship between the occurrence of fish and the egg predators suggests the surprising conclusion that the presence of fish actually protects aquatic anuran eggs from predation in this tropical system, and allows aquatic oviposition to dominate only in those waterbodies with moderate to high densities of fish. Our results suggest that terrestrial oviposition is a "fixed predator avoidance" trait.

Critical appraisal of surgical revascularization for critical limb ischemia.

PubMed

Conte, Michael S

2013-02-01

Peripheral artery disease is growing in global prevalence and is estimated to afflict between 8 and 12 million Americans. Its most severe form, critical limb ischemia (CLI), is associated with high rates of limb loss, morbidity, and mortality. Revascularization is the cornerstone of limb preservation in CLI, and has traditionally been accomplished with open surgical bypass. Advances in catheter-based technologies, coupled with their broad dissemination among specialists, have led to major shifts in practice patterns in CLI. There is scant high-quality evidence to guide surgical decision making in this arena, and market forces have exerted profound influences. Despite this, available data suggest that the expected outcomes for both endovascular and open surgery in CLI are strongly dependent on definable patient factors such as anatomic distribution of disease, vein quality, and comorbidities. Optimal patient selection is paramount for maximizing benefit with each technique. This review summarizes some of the existing data and suggests a selective approach to revascularization in CLI, which continues to rely on vein bypass surgery as a primary option in appropriately selected patients. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Glyphosate-resistant weeds of South American cropping systems: an overview.

PubMed

Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

2008-04-01

Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. Copyright (c) 2007 Society of Chemical Industry.

Selective Attention Modulates the Direction of Audio-Visual Temporal Recalibration

PubMed Central

Ikumi, Nara; Soto-Faraco, Salvador

2014-01-01

Temporal recalibration of cross-modal synchrony has been proposed as a mechanism to compensate for timing differences between sensory modalities. However, far from the rich complexity of everyday life sensory environments, most studies to date have examined recalibration on isolated cross-modal pairings. Here, we hypothesize that selective attention might provide an effective filter to help resolve which stimuli are selected when multiple events compete for recalibration. We addressed this question by testing audio-visual recalibration following an adaptation phase where two opposing audio-visual asynchronies were present. The direction of voluntary visual attention, and therefore to one of the two possible asynchronies (flash leading or flash lagging), was manipulated using colour as a selection criterion. We found a shift in the point of subjective audio-visual simultaneity as a function of whether the observer had focused attention to audio-then-flash or to flash-then-audio groupings during the adaptation phase. A baseline adaptation condition revealed that this effect of endogenous attention was only effective toward the lagging flash. This hints at the role of exogenous capture and/or additional endogenous effects producing an asymmetry toward the leading flash. We conclude that selective attention helps promote selected audio-visual pairings to be combined and subsequently adjusted in time but, stimulus organization exerts a strong impact on recalibration. We tentatively hypothesize that the resolution of recalibration in complex scenarios involves the orchestration of top-down selection mechanisms and stimulus-driven processes. PMID:25004132

Selective attention modulates the direction of audio-visual temporal recalibration.

PubMed

Ikumi, Nara; Soto-Faraco, Salvador

2014-01-01

Temporal recalibration of cross-modal synchrony has been proposed as a mechanism to compensate for timing differences between sensory modalities. However, far from the rich complexity of everyday life sensory environments, most studies to date have examined recalibration on isolated cross-modal pairings. Here, we hypothesize that selective attention might provide an effective filter to help resolve which stimuli are selected when multiple events compete for recalibration. We addressed this question by testing audio-visual recalibration following an adaptation phase where two opposing audio-visual asynchronies were present. The direction of voluntary visual attention, and therefore to one of the two possible asynchronies (flash leading or flash lagging), was manipulated using colour as a selection criterion. We found a shift in the point of subjective audio-visual simultaneity as a function of whether the observer had focused attention to audio-then-flash or to flash-then-audio groupings during the adaptation phase. A baseline adaptation condition revealed that this effect of endogenous attention was only effective toward the lagging flash. This hints at the role of exogenous capture and/or additional endogenous effects producing an asymmetry toward the leading flash. We conclude that selective attention helps promote selected audio-visual pairings to be combined and subsequently adjusted in time but, stimulus organization exerts a strong impact on recalibration. We tentatively hypothesize that the resolution of recalibration in complex scenarios involves the orchestration of top-down selection mechanisms and stimulus-driven processes.

Autoimmunity as a Driving Force of Cognitive Evolution

PubMed Central

Nataf, Serge

2017-01-01

In the last decades, increasingly robust experimental approaches have formally demonstrated that autoimmunity is a physiological process involved in a large range of functions including cognition. On this basis, the recently enunciated “brain superautoantigens” theory proposes that autoimmunity has been a driving force of cognitive evolution. It is notably suggested that the immune and nervous systems have somehow co-evolved and exerted a mutual selection pressure benefiting to both systems. In this two-way process, the evolutionary-determined emergence of neurons expressing specific immunogenic antigens (brain superautoantigens) has exerted a selection pressure on immune genes shaping the T-cell repertoire. Such a selection pressure on immune genes has translated into the emergence of a finely tuned autoimmune T-cell repertoire that promotes cognition. In another hand, the evolutionary-determined emergence of brain-autoreactive T-cells has exerted a selection pressure on neural genes coding for brain superautoantigens. Such a selection pressure has translated into the emergence of a neural repertoire (defined here as the whole of neurons, synapses and non-neuronal cells involved in cognitive functions) expressing brain superautoantigens. Overall, the brain superautoantigens theory suggests that cognitive evolution might have been primarily driven by internal cues rather than external environmental conditions. Importantly, while providing a unique molecular connection between neural and T-cell repertoires under physiological conditions, brain superautoantigens may also constitute an Achilles heel responsible for the particular susceptibility of Homo sapiens to “neuroimmune co-pathologies” i.e., disorders affecting both neural and T-cell repertoires. These may notably include paraneoplastic syndromes, multiple sclerosis as well as autism, schizophrenia and neurodegenerative diseases. In the context of this theoretical frame, a specific emphasis is given here to the potential evolutionary role exerted by two families of genes, namely the MHC class II genes, involved in antigen presentation to T-cells, and the Foxp genes, which play crucial roles in language (Foxp2) and the regulation of autoimmunity (Foxp3). PMID:29123465

Enemy targeting, trade-offs, and the evolutionary assembly of a tortoise beetle defense arsenal

USDA-ARS?s Scientific Manuscript database

In response to intense enemy selection, immature folivorous insects have evolved elaborate, multi-trait defense arsenals. How enemies foster trait diversification and arsenal assembly depends on which selective mode they impose: whether different enemies select for the same defense or exert conflict...

Personal Values as Mitigating Factors in the Link between Income and Life Satisfaction: Evidence from the European Social Survey

ERIC Educational Resources Information Center

Georgellis, Yannis; Tsitsianis, Nicholas; Yin, Ya Ping

2009-01-01

Using data from the first two rounds of the European Social Survey, we examine the link between income, reference income and life satisfaction across Western Europe. We find that whilst there is a strong positive relationship between income and life satisfaction, reference or comparison income exerts a strong negative influence. Interestingly, our…

Basolateral amygdalar D2 receptor activation is required for the companions-exerted suppressive effect on the cocaine conditioning.

PubMed

Tzeng, Wen-Yu; Cherng, Chian-Fang G; Yu, Lung; Wang, Ching-Yi

2017-01-01

The presence of companions renders decreases in cocaine-stimulated dopamine release in the nucleus accumbens and cocaine-induced conditioned place preference (CPP) magnitude. Limbic systems are widely believed to underlie the modulation of accumbal dopamine release and cocaine conditioning. Thus, this study aimed to assess whether intact basolateral nucleus of amygdala (BLA), dorsal hippocampus (DH), and dorsolateral striatum (DLS) is required for the companions-exerted suppressive effect on the cocaine-induced CPP. Three cage mates, serving as companions, were arranged to house with the experimental mice in the cocaine conditioning compartment throughout the cocaine conditioning sessions. Approximately 1week before the conditioning procedure, intracranial ibotenic acid infusions were done in an attempt to cause excitotoxic lesions targeting bilateral BLA, DH and DLS. Albeit their BLA, DH, and DLS lesions, the lesioned mice exhibited comparable cocaine-induced CPP magnitudes compared to the intact and sham lesion controls. Bilateral BLA, but not DH or DLS, lesions abolished the companions-exerted suppressive effect on the cocaine-induced CPP. Intact mice receiving intra-BLA infusion of raclopride, a selective D2 antagonist, 30min prior to the cocaine conditioning did not exhibit the companions-exerted suppressive effect on the cocaine-induced CPP. Intra-BLA infusion of Sch23390, a selective D1 antagonist, did not affect the companions-exerted suppressive effect on the CPP. These results, taken together, prompt us to conclude that the intactness of BLA is required for the companions-exerted suppressive effect on the cocaine-induced CPP. Importantly, activation of D2 receptor in the BLA is required for such suppressive effect on the CPP. Copyright © 2016 Elsevier Inc. All rights reserved.

Ratings of Perceived Exertion During Acute Resistance Exercise Performed at Imposed and Self-Selected Loads in Recreationally Trained Women.

PubMed

Cotter, Joshua A; Garver, Matthew J; Dinyer, Taylor K; Fairman, Ciaran M; Focht, Brian C

2017-08-01

Cotter, JA, Garver, MJ, Dinyer, TK, Fairman, CM, and Focht, BC. Ratings of perceived exertion during acute resistance exercise performed at imposed and self-selected loads in recreationally trained women. J Strength Cond Res 31(8): 2313-2318, 2017-Resistance exercise (RE) is commonly used to elicit skeletal muscle adaptation. Relative intensity of a training load links closely with the outcomes of regular RE. This study examined the rating of perceived exertion (RPE) responses to acute bouts of RE using imposed (40% and 70% of 1 repetition maximum [1RM]) and self-selected (SS) loads in recreationally trained women. Twenty physically active women (23.15 ± 2.92 years), who reported regular RE training of at least 3 weekly sessions for the past year, volunteered to participate. During the initial visit, participants completed 1RM testing on 4 exercises in the following order: leg extension, chest press, leg curl, and lat pull-down. On subsequent visits, the same exercises were completed at the SS or imposed loads. The RPE was assessed after the completion of each set of exercises during the 3 RE conditions using the Borg-15 category scale. Self-selected loads corresponded to an average of approximately 57%1RM (±7.62). Overall, RPE increased with load (40%1RM = 11.26 [±1.95]; SS 57%1RM = 13.94 [±1.58]; and, 70%1RM = 15.52 [±2.05]). Reflecting the linear pattern found between load and perceived effort, the present data provide evidence that RPE levels less than 15 likely equate to loads which are not consistent with contemporary American College of Sports Medicine (ACSM) guidelines for enhancing musculoskeletal health which includes strength and hypertrophy. Women desiring increases in strength and lean mass likely need to train at an exertion level at or surpassing a rating of 15 on the Borg-15 category. This article examined the modification of training load on perceived exertion, but other variables, such as the number of repetitions completed, may also be targeted to achieve a desired RPE. The primary understanding is that women who engage in RE may not self-select loads that are consistent with the ACSM recommendations for musculoskeletal health.

Crystal structures of nematode (parasitic T. spiralis and free living C. elegans), compared to mammalian, thymidylate synthases (TS). Molecular docking and molecular dynamics simulations in search for nematode-specific inhibitors of TS.

PubMed

Jarmuła, Adam; Wilk, Piotr; Maj, Piotr; Ludwiczak, Jan; Dowierciał, Anna; Banaszak, Katarzyna; Rypniewski, Wojciech; Cieśla, Joanna; Dąbrowska, Magdalena; Frączyk, Tomasz; Bronowska, Agnieszka K; Jakowiecki, Jakub; Filipek, Sławomir; Rode, Wojciech

2017-10-01

Three crystal structures are presented of nematode thymidylate synthases (TS), including Caenorhabditis elegans (Ce) enzyme without ligands and its ternary complex with dUMP and Raltitrexed, and binary complex of Trichinella spiralis (Ts) enzyme with dUMP. In search of differences potentially relevant for the development of species-specific inhibitors of the nematode enzyme, a comparison was made of the present Ce and Ts enzyme structures, as well as binary complex of Ce enzyme with dUMP, with the corresponding mammalian (human, mouse and rat) enzyme crystal structures. To complement the comparison, tCONCOORD computations were performed to evaluate dynamic behaviors of mammalian and nematode TS structures. Finally, comparative molecular docking combined with molecular dynamics and free energy of binding calculations were carried out to search for ligands showing selective affinity to T. spiralis TS. Despite an overall strong similarity in structure and dynamics of nematode vs mammalian TSs, a pool of ligands demonstrating predictively a strong and selective binding to TsTS has been delimited. These compounds, the E63 family, locate in the dimerization interface of TsTS where they exert species-specific interactions with certain non-conserved residues, including hydrogen bonds with Thr174 and hydrophobic contacts with Phe192, Cys191 and Tyr152. The E63 family of ligands opens the possibility of future development of selective inhibitors of TsTS and effective agents against trichinellosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Lack of Impact of Posidonia oceanica Leaf Nutrient Enrichment on Sarpa salpa Herbivory: Additional Evidence for the Generalist Consumer Behavior of This Cornerstone Mediterranean Herbivore.

PubMed

Marco-Méndez, Candela; Wessel, Caitlin; Scheffel, Whitney; Ferrero-Vicente, Luis; Fernández-Torquemada, Yolanda; Cebrián, Just; Heck, Kenneth L; Sánchez-Lizaso, Jose Luis

2016-01-01

The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean. Through direct and indirect mechanisms, this herbivore can exert significant control on the structure and functional dynamics of seagrass beds and macroalgae. Past research has suggested nutritional quality of their diet influences S. salpa herbivory, with the fish feeding more intensively and exerting greater top down control on macrophytes with higher internal nutrient contents. However recent findings have questioned this notion and shown that herbivores do not preferentially feed on macrophytes with higher nutrient contents, but rather feed on a wide variety of them with no apparent selectivity. To contribute to this debate, we conducted a field fertilization experiment where we enriched leaves of the seagrass Posidonia oceanica, a staple diet for S. salpa, and examined the response by the herbivore. These responses included quantification of leaf consumption in fertilized and non-fertilized/control plots within the bed, and food choice assays where fertilized and non-fertilized/control leaves were simultaneously offered to the herbivore. Despite the duration of leaf exposure to herbivores (30 days) and abundant schools of S. salpa observed around the plots, leaf consumption was generally low in the plots examined. Consumption was not higher on fertilized than on non-fertilized leaves. Food choice experiments did not show strong evidence for selectivity of enriched leaves. These results add to a recent body of work reporting a broad generalist feeding behavior by S. salpa with no clear selectivity for seagrass with higher nutrient content. In concert, this and other studies suggest S. salpa is often generalist consumers not only dictated by diet nutrient content but by complex interactions between other traits of nutritional quality, habitat heterogeneity within their ample foraging area, and responses to predation risk.

Lack of Impact of Posidonia oceanica Leaf Nutrient Enrichment on Sarpa salpa Herbivory: Additional Evidence for the Generalist Consumer Behavior of This Cornerstone Mediterranean Herbivore

PubMed Central

Marco-Méndez, Candela; Wessel, Caitlin; Scheffel, Whitney; Ferrero-Vicente, Luis; Fernández-Torquemada, Yolanda; Cebrián, Just; Heck, Kenneth L.; Sánchez-Lizaso, Jose Luis

2016-01-01

The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean. Through direct and indirect mechanisms, this herbivore can exert significant control on the structure and functional dynamics of seagrass beds and macroalgae. Past research has suggested nutritional quality of their diet influences S. salpa herbivory, with the fish feeding more intensively and exerting greater top down control on macrophytes with higher internal nutrient contents. However recent findings have questioned this notion and shown that herbivores do not preferentially feed on macrophytes with higher nutrient contents, but rather feed on a wide variety of them with no apparent selectivity. To contribute to this debate, we conducted a field fertilization experiment where we enriched leaves of the seagrass Posidonia oceanica, a staple diet for S. salpa, and examined the response by the herbivore. These responses included quantification of leaf consumption in fertilized and non-fertilized/control plots within the bed, and food choice assays where fertilized and non-fertilized/control leaves were simultaneously offered to the herbivore. Despite the duration of leaf exposure to herbivores (30 days) and abundant schools of S. salpa observed around the plots, leaf consumption was generally low in the plots examined. Consumption was not higher on fertilized than on non-fertilized leaves. Food choice experiments did not show strong evidence for selectivity of enriched leaves. These results add to a recent body of work reporting a broad generalist feeding behavior by S. salpa with no clear selectivity for seagrass with higher nutrient content. In concert, this and other studies suggest S. salpa is often generalist consumers not only dictated by diet nutrient content but by complex interactions between other traits of nutritional quality, habitat heterogeneity within their ample foraging area, and responses to predation risk. PMID:27992498

Contrasting selective pressures on seed traits of two congeneric species by their main native guilds of dispersers on islands.

PubMed

Nogales, Manuel; González-Castro, Aarón; Marrero, Patricia; Bonnaud, Elsa; Traveset, Anna

2013-01-01

Many fleshy-fruited plants from the Mediterranean and Macaronesian islands are dispersed through endozoochory. In mainland Mediterranean areas, reciprocal adaptations have been found between plants and animals, although evidence is scarce. On small isolated oceanic islands, such reciprocal adaptations might well be more prevalent due to intrinsic island traits. Here we evaluate the existence of selective pressures exerted by two different disperser guilds (lizards and birds) on two seed traits (seed coat thickness and seed germination pattern) of two congeneric species present on Mediterranean and Macaronesian islands. In the continental Balearic Islands, Rubia peregrina has evolved mostly with birds, although frugivorous lizards are present in some of these islands and are known to eventually consume its fruits. By contrast, R. fruticosa, endemic to the Macaronesian archipelago, has evolved mostly interacting with lizards and only recently with birds. We hypothesized that R. fruticosa would be especially adapted to saurochory, with thicker seed coats and higher germination proportion, whereas R. peregrina would be more adapted to ornithocory, with thinner seed coats and showing a lower germination percentage after being ingested by lizards. Captivity experiments of seed ingestions by natural and non-natural dispersers (i.e., frugivores that have not evolved with those plants) were conducted. Results suggest that dispersers did not exert any strong enough selective pressure to induce changes in germination patterns. We attribute this to the fact that the Rubiaceae is an ancestral family in the Mediterranean (both on continent and islands) and thus probably interacted with lizards in the past. Lastly, although we hold that the seed coat structure of R. fruticosa is probably associated with its evolutionary success after a long interaction with insular lizards, our findings support the idea that the relationship between endozoochorous plants and the guild of dispersers with whom they evolved is rather unspecific.

Contrasting Selective Pressures on Seed Traits of Two Congeneric Species by Their Main Native Guilds of Dispersers on Islands

PubMed Central

Nogales, Manuel; González-Castro, Aarón; Marrero, Patricia; Bonnaud, Elsa; Traveset, Anna

2013-01-01

Many fleshy-fruited plants from the Mediterranean and Macaronesian islands are dispersed through endozoochory. In mainland Mediterranean areas, reciprocal adaptations have been found between plants and animals, although evidence is scarce. On small isolated oceanic islands, such reciprocal adaptations might well be more prevalent due to intrinsic island traits. Here we evaluate the existence of selective pressures exerted by two different disperser guilds (lizards and birds) on two seed traits (seed coat thickness and seed germination pattern) of two congeneric species present on Mediterranean and Macaronesian islands. In the continental Balearic Islands, Rubia peregrina has evolved mostly with birds, although frugivorous lizards are present in some of these islands and are known to eventually consume its fruits. By contrast, R. fruticosa, endemic to the Macaronesian archipelago, has evolved mostly interacting with lizards and only recently with birds. We hypothesized that R. fruticosa would be especially adapted to saurochory, with thicker seed coats and higher germination proportion, whereas R. peregrina would be more adapted to ornithocory, with thinner seed coats and showing a lower germination percentage after being ingested by lizards. Captivity experiments of seed ingestions by natural and non-natural dispersers (i.e., frugivores that have not evolved with those plants) were conducted. Results suggest that dispersers did not exert any strong enough selective pressure to induce changes in germination patterns. We attribute this to the fact that the Rubiaceae is an ancestral family in the Mediterranean (both on continent and islands) and thus probably interacted with lizards in the past. Lastly, although we hold that the seed coat structure of R. fruticosa is probably associated with its evolutionary success after a long interaction with insular lizards, our findings support the idea that the relationship between endozoochorous plants and the guild of dispersers with whom they evolved is rather unspecific. PMID:23667598

Responding to social and symbolic extrafoveal cues: cue shape trumps biological relevance.

PubMed

Hermens, Frouke; Bindemann, Markus; Mike Burton, A

2017-01-01

Social cues presented at visual fixation have been shown to strongly influence an observer's attention and response selection. Here we ask whether the same holds for cues (initially) presented away from fixation, as cues are commonly perceived in natural vision. In six experiments, we show that extrafoveally presented cues with a distinct outline, such as pointing hands, rotated heads, and arrow cues result in strong cueing of responses (either to the cue itself, or a cued object). In contrast, cues without a clear outline, such as gazing eyes and direction words exert much weaker effects on participants' responses to a target cue. We also show that distraction effects on response times are relatively weak, but that strong interference effects can be obtained by measuring mouse trajectories. Eye tracking suggests that gaze cues are slower to respond to because their direction cannot easily be perceived in extrafoveal vision. Together, these data suggest that the strength of an extrafoveal cue is determined by the shape of the cue outline, rather than its biological relevance (i.e., whether the cue is provided by another human being), and that this shape effect is due to how easily the direction of a cue can be perceived in extrafoveal vision.

Role of chronic exercise on pelvic floor support and function

PubMed Central

Shaw, Janet M.; Nygaard, Ingrid E.

2017-01-01

Purpose of review To summarize recent literature about the potential role of chronic exercise on pelvic floor support and function. Recent findings Stress urinary incontinence is common during physical activity. Scant evidence suggests a dose-response association between higher volumes of exercise and urinary incontinence. Athletes do not appear to have greater pelvic floor muscle strength or worse pelvic floor support compared to non-athletes. Pelvic floor muscle electromyographic activity increases substantially as running speeds increase. Summary Based on the current literature, no strong conclusions can be drawn about whether chronic exercise exerts a positive or negative influence on pelvic floor support and function. Adopting longitudinal research methodology that prospectively monitors exercise exposure and subsequent changes in pelvic floor support and function would help to reduce selection bias associated with cross sectional studies on groups of athletes. PMID:28212118

Fitness to work of astronauts in conditions of action of the extreme emotional factors

NASA Astrophysics Data System (ADS)

Prisniakova, L. M.

2004-01-01

The theoretical model for the quantitative determination of influence of a level of emotional exertion on the success of human activity is presented. The learning curves of fixed words in the groups with a different level of the emotional exertion are analyzed. The obtained magnitudes of time constant T depending on a type of the emotional exertion are a quantitative measure of the emotional exertion. Time constants could also be of use for a prediction of the characteristic of fitness to work of an astronaut in conditions of extreme factors. The inverse of the sign of influencing on efficiency of activity of the man is detected. The paper offers a mathematical model of the relation between successful activity and motivations or the emotional exertion (Yerkes-Dodson law). Proposed models can serve by the theoretical basis of the quantitative characteristics of an estimation of activity of astronauts in conditions of the emotional factors at a phase of their selection.

Fitness to work of astronauts in conditions of action of the extreme emotional factors.

PubMed

Prisniakova, L M

2004-01-01

The theoretical model for the quantitative determination of influence of a level of emotional exertion on the success of human activity is presented. The learning curves of fixed words in the groups with a different level of the emotional exertion are analyzed. The obtained magnitudes of time constant T depending on a type of the emotional exertion are a quantitative measure of the emotional exertion. Time constants could also be of use for a prediction of the characteristic of fitness to work of an astronaut in conditions of extreme factors. The inverse of the sign of influencing on efficiency of activity of the man is detected. The paper offers a mathematical model of the relation between successful activity and motivations or the emotional exertion (Yerkes-Dodson law). Proposed models can serve by the theoretical basis of the quantitative characteristics of an estimation of activity of astronauts in conditions of the emotional factors at a phase of their selection. Published by Elsevier Ltd on behalf of COSPAR.

DNA adducts of ethylene dibromide: Aspects of formation and mutagenicity

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

Cmarik, J.L.

1,2-Dibromoethane (ethylene dibromide, EDB), a potential human carcinogen, undergoes bioactivation by the pathway of glutathione (GSH) conjugation, which generates a reactive intermediate capable of alkylating DNA. The major DNA adduct formed is S-[2-(N[sup 7]-guanyl)ethyl]GSH. This dissertation examined the bioactivation of EDB and the formation of DNA adducts. The selectivity of purified rat and human GSH S-transferases for EDB was examined in vitro. An assay was developed to measure the formation of S,S[prime]-ethylene-bis(GSH). The [alpha] class of the GSH S-transferases was responsible for the majority of EDB-GSH conjugation with both the rat and human enzymes. Human tissue samples for a victimmore » of EDB poisoning were analyzed for S-[2-(N[sup 7]-guanyl)ethyl]GSH utilizing electrochemical detection. No adducts were detected in samples of brain, heart, or kidney. The pattern of alkylation of guanines in fragments of plasmid pBR322 DNA by S-(2-chloroethyl)GSH and related compounds was determined. Alkylation varied approximately ten-fold in intensity and was strongest in runs of guanines. Few differences were observed in the alkylation patterns generated by the different compounds tested. The spectrum of mutations caused by S-(2-chloroethyl)GSH was determined using an M13 bacteriophage forward mutation assay. The majority of mutations (70%) were G:C to A:T transitions. Participation of the N[sup 7]-guanyl adduct in the mutagenic process is strongly implicated. The sequence selectivity of alkylation in the region of M13 sequenced in the mutation assay was determined. Comparison of the sequence selectivity with the mutation spectrum revealed no obligate relationship between the extent of adduct formation and the number of mutations which resulted at different sites. Sequence context appears to exert a strong influence on the processing of lesions. These studies strongly implicate S-[2-(N[sup 7]-guanyl)-ethyl]GSH as a mutagenic lesion formed by EDB.« less

Sympatric speciation by sexual selection alone is unlikely.

PubMed

Arnegard, Matthew E; Kondrashov, Alexey S

2004-02-01

According to Darwin, sympatric speciation is driven by disruptive, frequency-dependent natural selection caused by competition for diverse resources. Recently, several authors have argued that disruptive sexual selection can also cause sympatric speciation. Here, we use hypergeometric phenotypic and individual-based genotypic models to explore sympatric speciation by sexual selection under a broad range of conditions. If variabilities of preference and display traits are each caused by more than one or two polymorphic loci, sympatric speciation requires rather strong sexual selection when females exert preferences for extreme male phenotypes. Under this kind of mate choice, speciation can occur only if initial distributions of preference and display are close to symmetric. Otherwise, the population rapidly loses variability. Thus, unless allele replacements at very few loci are enough for reproductive isolation, female preferences for extreme male displays are unlikely to drive sympatric speciation. By contrast, similarity-based female preferences that do not cause sexual selection are less destabilizing to the maintenance of genetic variability and may result in sympatric speciation across a broader range of initial conditions. Certain groups of African cichlids have served as the exclusive motivation for the hypothesis of sympatric speciation by sexual selection. Mate choice in these fishes appears to be driven by female preferences for extreme male phenotypes rather than similarity-based preferences, and the evolution of premating reproductive isolation commonly involves at least several genes. Therefore, differences in female preferences and male display in cichlids and other species of sympatric origin are more likely to have evolved as isolating mechanisms under disruptive natural selection.

Scaling Considerations Related to Interactions of Hydrologics, Pedologic and Geomorphic Processes

EPA Science Inventory

Hydrologic, pedologic, and geomorphic processes are strongly interrelated and affected by scale. These interactions exert important controls on runoff generation, preferential flow, contaminant transport, surface erosion, and mass wasting. Measurement of hydraulic conductivity (K...

The Automaticity of Emotional Face-Context Integration

PubMed Central

Aviezer, Hillel; Dudarev, Veronica; Bentin, Shlomo; Hassin, Ran R.

2011-01-01

Recent studies have demonstrated that context can dramatically influence the recognition of basic facial expressions, yet the nature of this phenomenon is largely unknown. In the present paper we begin to characterize the underlying process of face-context integration. Specifically, we examine whether it is a relatively controlled or automatic process. In Experiment 1 participants were motivated and instructed to avoid using the context while categorizing contextualized facial expression, or they were led to believe that the context was irrelevant. Nevertheless, they were unable to disregard the context, which exerted a strong effect on their emotion recognition. In Experiment 2, participants categorized contextualized facial expressions while engaged in a concurrent working memory task. Despite the load, the context exerted a strong influence on their recognition of facial expressions. These results suggest that facial expressions and their body contexts are integrated in an unintentional, uncontrollable, and relatively effortless manner. PMID:21707150

The Effects of Mental Fatigue on Physical Performance: A Systematic Review.

PubMed

Van Cutsem, Jeroen; Marcora, Samuele; De Pauw, Kevin; Bailey, Stephen; Meeusen, Romain; Roelands, Bart

2017-08-01

Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity. It has recently been suggested that mental fatigue can affect physical performance. Our objective was to evaluate the literature on impairment of physical performance due to mental fatigue and to create an overview of the potential factors underlying this effect. Two electronic databases, PubMed and Web of Science (until 28 April 2016), were searched for studies designed to test whether mental fatigue influenced performance of a physical task or influenced physiological and/or perceptual responses during the physical task. Studies using short (<30 min) self-regulatory depletion tasks were excluded from the review. A total of 11 articles were included, of which six were of strong and five of moderate quality. The general finding was a decline in endurance performance (decreased time to exhaustion and self-selected power output/velocity or increased completion time) associated with a higher than normal perceived exertion. Physiological variables traditionally associated with endurance performance (heart rate, blood lactate, oxygen uptake, cardiac output, maximal aerobic capacity) were unaffected by mental fatigue. Maximal strength, power, and anaerobic work were not affected by mental fatigue. The duration and intensity of the physical task appear to be important factors in the decrease in physical performance due to mental fatigue. The most important factor responsible for the negative impact of mental fatigue on endurance performance is a higher perceived exertion.

Common Mechanism Underlies Repeated Evolution of Extreme Pollution Tolerance

EPA Science Inventory

Human alterations to the environment can exert strong evolutionary pressures, yet contemporary adaptation to human-mediated stressors is rarely documented in wild populations. A common-garden experimental design was coupled with comparative transcriptomics to discover evolved me...

ASP6537, a novel highly selective cyclooxygenase-1 inhibitor, exerts potent antithrombotic effect without "aspirin dilemma".

PubMed

Sakata, Chinatsu; Kawasaki, Tomihisa; Kato, Yasuko; Abe, Masaki; Suzuki, Ken-ichi; Ohmiya, Makoto; Funatsu, Toshiyuki; Morita, Yoshiaki; Okada, Masamichi

2013-07-01

Aspirin inhibits both the cyclooxygenase (COX)-1-dependent production of thromboxane A2 (TXA2) in platelets and COX-2-dependent production of anti-aggregatory prostaglandin I2 (PGI2) in vessel walls, resulting in "aspirin dilemma." Our objective is to investigate whether ASP6537 can overcome aspirin dilemma and exert a potent antithrombotic effect without a concurrent ulcerogenic effect. We evaluated the inhibitory effects of ASP6537 on recombinant human COX-1 (rhCOX-1) and rhCOX-2 activities using a COX-1/2 selectivity test. To determine whether ASP6537 induces aspirin dilemma, we examined the effects of ASP6537 on in vitro TXA2 and PGI2 metabolite production from platelets and isolated aorta of guinea pigs, and on plasma concentrations of TXA2 and PGI2 metabolites in aged rats. Finally, we evaluated the antithrombotic effects and ulcerogenic activity of ASP6537 using an electrically induced carotid arterial thrombosis model and a gastric ulcer model in guinea pigs. The IC50 ratios of rhCOX-2 to rhCOX-1 for ASP6537 and aspirin were >142,000 and 1.63 fold, respectively. ASP6537 inhibited TXA2 production more selectively than aspirin in in vitro and in vivo TXA2/PGI2 production studies. ASP6537 exerted a significant antithrombotic effect at ≥3 mg/kg, while aspirin tended to inhibit thrombosis at 300 mg/kg but it was not statistically significant. Further, ASP6537 did not induce ulcer formation at 100 mg/kg, whereas aspirin exhibited an ulcerogenic effect at doses of ≥100 mg/kg. ASP6537 functions as a highly selective COX-1 inhibitor with a superior ability to aspirin for normalizing TXA2/PGI2 balance, and exerts antithrombotic effect without ulcerogenic effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evolution of Drosophila resistance against different pathogens and infection routes entails no detectable maintenance costs.

PubMed

Faria, Vítor G; Martins, Nelson E; Paulo, Tânia; Teixeira, Luís; Sucena, Élio; Magalhães, Sara

2015-11-01

Pathogens exert a strong selective pressure on hosts, entailing host adaptation to infection. This adaptation often affects negatively other fitness-related traits. Such trade-offs may underlie the maintenance of genetic diversity for pathogen resistance. Trade-offs can be tested with experimental evolution of host populations adapting to parasites, using two approaches: (1) measuring changes in immunocompetence in relaxed-selection lines and (2) comparing life-history traits of evolved and control lines in pathogen-free environments. Here, we used both approaches to examine trade-offs in Drosophila melanogaster populations evolving for over 30 generations under infection with Drosophila C Virus or the bacterium Pseudomonas entomophila, the latter through different routes. We find that resistance is maintained after up to 30 generations of relaxed selection. Moreover, no differences in several classical life-history traits between control and evolved populations were found in pathogen-free environments, even under stresses such as desiccation, nutrient limitation, and high densities. Hence, we did not detect any maintenance costs associated with resistance to pathogens. We hypothesize that extremely high selection pressures commonly used lead to the disproportionate expression of costs relative to their actual occurrence in natural systems. Still, the maintenance of genetic variation for pathogen resistance calls for an explanation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

PPARγ partial agonist GQ-16 strongly represses a subset of genes in 3T3-L1 adipocytes

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

Milton, Flora Aparecida; Genomic Medicine, Houston Methodist Research Institute, Houston, TX; Cvoro, Aleksandra

Thiazolidinediones (TZDs) are peroxisome proliferator-activated receptor gamma (PPARγ) agonists that improve insulin resistance but trigger side effects such as weight gain, edema, congestive heart failure and bone loss. GQ-16 is a PPARγ partial agonist that improves glucose tolerance and insulin sensitivity in mouse models of obesity and diabetes without inducing weight gain or edema. It is not clear whether GQ-16 acts as a partial agonist at all PPARγ target genes, or whether it displays gene-selective actions. To determine how GQ-16 influences PPARγ activity on a gene by gene basis, we compared effects of rosiglitazone (Rosi) and GQ-16 in mature 3T3-L1more » adipocytes using microarray and qRT-PCR. Rosi changed expression of 1156 genes in 3T3-L1, but GQ-16 only changed 89 genes. GQ-16 generally showed weak effects upon Rosi induced genes, consistent with partial agonist actions, but a subset of modestly Rosi induced and strongly repressed genes displayed disproportionately strong GQ-16 responses. PPARγ partial agonists MLR24 and SR1664 also exhibit disproportionately strong effects on transcriptional repression. We conclude that GQ-16 displays a continuum of weak partial agonist effects but efficiently represses some negatively regulated PPARγ responsive genes. Strong repressive effects could contribute to physiologic actions of GQ-16. - Highlights: • GQ-16 is an insulin sensitizing PPARγ ligand with reduced harmful side effects. • GQ-16 displays a continuum of weak partial agonist activities at PPARγ-induced genes. • GQ-16 exerts strong repressive effects at a subset of genes. • These inhibitor actions should be evaluated in models of adipose tissue inflammation.« less

Influence of agronomic variables on the composition of mate tea leaves (Ilex paraguariensis) extracts obtained from CO2 extraction at 30 degrees C and 175 bar.

PubMed

Esmelindro, Angela Aquino; Girardi, Jonathan Dos Santos; Mossi, Altemir; Jacques, Rosângela Assis; Dariva, Cláudio

2004-04-07

The aim of this work is to assess the influence of light intensity (plants with direct sun exposure and in a controlled light intensity) and age of leaves (6-24 months) on the characteristics of the extracts of mate tea leaves obtained from carbon dioxide at high pressures. Samples of mate were collected in an experiment conducted under agronomic control at Industria e Comercio de Erva-Mate Barão LTDA, Brazil. The content of selected organic compounds of the extracts was evaluated by gas chromatography together with mass spectrometry. Quantitative analysis of caffeine, theobromine, phytol, vitamin E, squalene, and stigmasterol was performed, and the results showed that field variables exert a strong influence on the liquid yield and on the chemical distribution of the extracts.

Material deprivation or minimal education? Social class and crime in an egalitarian welfare state.

PubMed

Savolainen, Jukka; Paananen, Reija; Merikukka, Marko; Aaltonen, Mikko; Gissler, Mika

2013-09-01

Research on social class and crime is dominated by perspectives that assume socioeconomic disadvantage to exert causal influence on offending. As an alternative approach, the present study examined hypotheses derived from a social selection perspective which treats intergenerational continuity in antisocial propensity as the primary source of socioeconomic differences in criminal activity. Under this theory, individual characteristics of the parents influence their personal socioeconomic attainment as well as the behavioral traits they pass on to their children. Consistent with both of these perspectives, longitudinal data tracking Finnish males born in 1987 (n=21,513) showed strong negative associations between family socioeconomic status (SES) and offspring rates of criminal offending. In critical support for the selection perspective: (1) these association were linear rather than discrete, (2) parents' educational attainment accounted for most of the association between the occupational measure of family SES and crime, and (3) measures of offspring criminal propensity mediated a substantial share of these effects. Adolescent educational marginalization emerged as the key factor linking childhood socioeconomic status to the risk of criminal offending in emerging adulthood. We discuss the implications of this finding for social influence and social selection models of explanation. Copyright © 2013 Elsevier Ltd. All rights reserved.

The genetic variance but not the genetic covariance of life-history traits changes towards the north in a time-constrained insect.

PubMed

Sniegula, Szymon; Golab, Maria J; Drobniak, Szymon M; Johansson, Frank

2018-06-01

Seasonal time constraints are usually stronger at higher than lower latitudes and can exert strong selection on life-history traits and the correlations among these traits. To predict the response of life-history traits to environmental change along a latitudinal gradient, information must be obtained about genetic variance in traits and also genetic correlation between traits, that is the genetic variance-covariance matrix, G. Here, we estimated G for key life-history traits in an obligate univoltine damselfly that faces seasonal time constraints. We exposed populations to simulated native temperatures and photoperiods and common garden environmental conditions in a laboratory set-up. Despite differences in genetic variance in these traits between populations (lower variance at northern latitudes), there was no evidence for latitude-specific covariance of the life-history traits. At simulated native conditions, all populations showed strong genetic and phenotypic correlations between traits that shaped growth and development. The variance-covariance matrix changed considerably when populations were exposed to common garden conditions compared with the simulated natural conditions, showing the importance of environmentally induced changes in multivariate genetic structure. Our results highlight the importance of estimating variance-covariance matrixes in environments that mimic selection pressures and not only trait variances or mean trait values in common garden conditions for understanding the trait evolution across populations and environments. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Generation of Novel Single-Chain Antibodies by Phage-Display Technology to Direct Imaging Agents Highly Selective to Pancreatic β- or α-Cells In Vivo

PubMed Central

Ueberberg, Sandra; Meier, Juris J.; Waengler, Carmen; Schechinger, Wolfgang; Dietrich, Johannes W.; Tannapfel, Andrea; Schmitz, Inge; Schirrmacher, Ralf; Köller, Manfred; Klein, Harald H.; Schneider, Stephan

2009-01-01

OBJECTIVE Noninvasive determination of pancreatic β-cell mass in vivo has been hampered by the lack of suitable β-cell–specific imaging agents. This report outlines an approach for the development of novel ligands homing selectively to islet cells in vivo. RESEARCH DESIGN AND METHODS To generate agents specifically binding to pancreatic islets, a phage library was screened for single-chain antibodies (SCAs) on rat islets using two different approaches. 1) The library was injected into rats in vivo, and islets were isolated after a circulation time of 5 min. 2) Pancreatic islets were directly isolated, and the library was panned in the islets in vitro. Subsequently, the identified SCAs were extensively characterized in vitro and in vivo. RESULTS We report the generation of SCAs that bind highly selective to either β- or α-cells. These SCAs are internalized by target cells, disappear rapidly from the vasculature, and exert no toxicity in vivo. Specific binding to β- or α-cells was detected in cell lines in vitro, in rats in vivo, and in human tissue in situ. Electron microscopy demonstrated binding of SCAs to the endoplasmatic reticulum and the secretory granules. Finally, in a biodistribution study the labeling intensity derived from [125I]-labeled SCAs after intravenous administration in rats strongly predicted the β-cell mass and was inversely related to the glucose excursions during an intraperitoneal glucose tolerance test. CONCLUSIONS Our data provide strong evidence that the presented SCAs are highly specific for pancreatic β-cells and enable imaging and quantification in vivo. PMID:19592622

The genetic structure of a Venturia inaequalis population in a heterogeneous host population composed of different Malus species

PubMed Central

2013-01-01

Background Adaptation, which induces differentiation between populations in relation to environmental conditions, can initiate divergence. The balance between gene flow and selection determines the maintenance of such a structure in sympatry. Studying these two antagonistic forces in plant pathogens is made possible because of the high ability of pathogens to disperse and of the strong selective pressures exerted by their hosts. In this article, we analysed the genetic structure of the population of the apple scab fungus, Venturia inaequalis, in a heterogeneous environment composed of various Malus species. Inferences were drawn from microsatellite and AFLP data obtained from 114 strains sampled in a single orchard on nine different Malus species to determine the forces that shape the genetic structure of the pathogen. Results Using clustering methods, we first identified two specialist subpopulations: (i) a virulent subpopulation sampled on Malus trees carrying the Rvi6 resistance gene; and (ii) a subpopulation infecting only Malus trees that did not carry this resistance gene. A genome scan of loci on these two subpopulations did not detect any locus under selection. Additionally, we did not detect any other particular substructure linked to different hosts. However, an isolation-by-distance (IBD) pattern at the orchard scale revealed free gene flow within each subpopulation. Conclusions Our work shows a rare example of a very strong effect of a resistance gene on pathogen populations. Despite the high diversity of Malus hosts, the presence of Rvi6 seems sufficient to explain the observed genetic structure. Moreover, detection of an IBD pattern at the orchard scale revealed a very low average dispersal distance that is particularly significant for epidemiologists and landscape managers for the design of scab control strategies PMID:23497223

Pathogen-mediated selection in free-ranging elk populations infected by chronic wasting disease

USDA-ARS?s Scientific Manuscript database

Pathogens can exert a large influence on the evolution of hosts via selection for alleles or genotypes that moderate pathogen virulence. Inconsistent interactions between parasites and the host genome, such as those resulting from genetic linkages and environmental stochasticity, have largely preven...

Sonotropic effects of commercial air transport sound on birds.

DOT National Transportation Integrated Search

1962-03-01

The Electra sound spectrum contains an audible chirp which appears identical in frequency and wave form to the chirp of field crickets. Field observations strongly indicate the sound of the taxiing Electra exerts an attraction for starlings, and poss...

Developing Landscape Level Indicators for Predicting Watershed Condition

EPA Science Inventory

Drainage basins (watersheds) exert a strong influence on the condition of water bodies such as streams and lakes. Watersheds and associated aquatic systems respond differently to stressors (e.g., land use change) or restoration activities depending on the climatic setting, bedroc...

Excitatory and inhibitory effects of opiates in the rat vas deferens: a dual mechanism of opiate action.

PubMed

Jacquet, Y F

1980-10-03

Both natural (-)-morphine and its unnatural enantiomer (+)-morphine exert an excitatory action on electrically stimulated contractions of rat vas deferens. Preexposure to (-)-morphine results in cross-tolerance to the inhibitory action of beta-endorphin. (-)-Naloxone and its stereoisomer (+)-naloxone also exert an excitatory action, but only (-)-naloxone bocks the inhibtory action of beta-endorphin. Thus morphine exerts a dual action on a peripheral organ: one an inhibitory action mediated by the stereospecific endorphin receptor that is blocked stereospecifically by naloxone, the other an excitatory action mediated by a nonstereospecific receptor that is not blocked by naloxone. The opiate abstinence syndrome is seen as due to the unmasking of the excitatory action of opiates when its concomitant inhibitory influence is removed by selective blockade by naloxone or weakened by selective tolerance. The view that the rat vas deferens is devoid of morphine receptors is now seen as arising from a reverse example of morphine's dual action: the masking of the inhibitory action of morphine by its concomitant and more potent excitatory action.

The influence of climate on species distribution over time and space during the late Quaternary

NASA Astrophysics Data System (ADS)

Carotenuto, F.; Di Febbraro, M.; Melchionna, M.; Castiglione, S.; Saggese, F.; Serio, C.; Mondanaro, A.; Passaro, F.; Loy, A.; Raia, P.

2016-10-01

Understanding the effect of climate on the composition of communities and its change over time and space is one of the major aims in ecology and paleoecology. Herein, we tackled on this issue by studying late Quaternary large mammal paleocommunities of Eurasia. The late Quaternary was a period of strong environmental instability, especially characterized by the occurrence of the last glacial maximum (LGM). We used community phylogenetics and joint species distribution models in order to understand the factors determining paleocommunity composition in the late Quaternary. Our results support the existence of strong climatic selection operating on the LGM fauna, both through the disappearance of warm-adapted species such as Elephas antiquus, Hippopothamus amphibious, and Stephanorhinus hemitoechus, and by setting the stage for the existence of a community characterized by cold-adapted large mammals. Patterns of abundance in the fossil record, co-occurrence between species pairs, and the extent of climatic forcing on faunal composition, differ between paleocommunities, but not between extinct and extant species, which is consistent with the idea that climate change, rather than the presence of humans, exerted a major effect on the survival of the late Quaternary megafauna.

Out of Sight, out of Mind: The Attentional Blink Can Eliminate Synaesthetic Colours

ERIC Educational Resources Information Center

Rich, Anina N.; Mattingley, Jason B.

2010-01-01

Mechanisms of selective attention exert a powerful influence on visual perception. We examined whether attentional selection is necessary for generation of the vivid colours experienced by individuals with grapheme-colour synaesthesia. Twelve synaesthetes and matched controls viewed rapid serial displays of nonsense characters within which were…

44 CFR 321.2 - Selection of the mobilization base.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS MAINTENANCE OF THE MOBILIZATION BASE (DEPARTMENT OF DEFENSE... of Defense shall select, for its mobilization base, facilities which produce or are capable of... items which would be so urgent to the defense of this country that utmost effort must be exerted to...

44 CFR 321.2 - Selection of the mobilization base.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS MAINTENANCE OF THE MOBILIZATION BASE (DEPARTMENT OF DEFENSE... of Defense shall select, for its mobilization base, facilities which produce or are capable of... items which would be so urgent to the defense of this country that utmost effort must be exerted to...

44 CFR 321.2 - Selection of the mobilization base.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS MAINTENANCE OF THE MOBILIZATION BASE (DEPARTMENT OF DEFENSE... of Defense shall select, for its mobilization base, facilities which produce or are capable of... items which would be so urgent to the defense of this country that utmost effort must be exerted to...

44 CFR 321.2 - Selection of the mobilization base.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS MAINTENANCE OF THE MOBILIZATION BASE (DEPARTMENT OF DEFENSE... of Defense shall select, for its mobilization base, facilities which produce or are capable of... items which would be so urgent to the defense of this country that utmost effort must be exerted to...

Preferred Exertion across Three Common Modes of Exercise Training.

ERIC Educational Resources Information Center

Glass, Stephen C.; Chvala, Angela M.

2001-01-01

Examined the influence of exercise mode on self-selected exercise intensities. Participants performed three types of intensity tests. Researchers collected data on VO2 values continuously and recorded 1-minute averages several times for each submaximal test. Participants allowed to self-select exercise intensity chose work rates within the…

Dyspnea on exertion in obese women: association with an increased oxygen cost of breathing.

PubMed

Babb, Tony G; Ranasinghe, Kamalini G; Comeau, Laurie A; Semon, Trisha L; Schwartz, Belinda

2008-07-15

Although exertional dyspnea in obesity is an important and prolific clinical concern, the underlying mechanism remains unclear. To investigate whether dyspnea on exertion in otherwise healthy obese women was associated with an increase in the oxygen cost of breathing or cardiovascular deconditioning. Obese women with and without dyspnea on exertion participated in two independent experiments (n = 16 and n = 14). All participants underwent pulmonary function testing, hydrostatic weighing, ratings of perceived breathlessness during cycling at 60 W, and determination of the oxygen cost of breathing during eucapnic voluntary hyperpnea at 40 and 60 L/min. Cardiovascular exercise capacity, fat distribution, and respiratory mechanics were determined in 14 women in experiment 2. Data were analyzed between groups by independent t test, and the relationship between the variables was determined by regression analysis. In both experiments, breathlessness during 60 W cycling was markedly increased in over 37% of the obese women (P < 0.01). Age, height, weight, lung function, and %body fat were not different between the groups in either experiment. In contrast, the oxygen cost of breathing was significantly (P < 0.01) and markedly (38-70%) greater in the obese women with dyspnea on exertion. The oxygen cost of breathing was significantly (P < 0.001) correlated with the rating of perceived breathlessness obtained during the 60 W exercise in experiment 1 (r(2) = 0.57) and experiment 2 (r(2) = 0.72). Peak cardiovascular exercise capacity, fat distribution, and respiratory mechanics were not different between groups in experiment 2. Dyspnea on exertion is prevalent in otherwise healthy obese women, which seems to be strongly associated with an increased oxygen cost of breathing. Exercise capacity is not reduced in obese women with dyspnea on exertion.

Skin Color, Life Changes, and Anti-White Attitudes

ERIC Educational Resources Information Center

Ransford, H. Edward

1970-01-01

Concludes that the skin color of Negroes is only a strong predictor of anti-white system" feelings among working-class and lower-class persons, those with no social contacts with whites, and those who feel powerless to exert control through institutional channels. (DM)

Hypoxia adaptations in the grey wolf (Canis lupus chanco) from Qinghai-Tibet Plateau.

PubMed

Zhang, Wenping; Fan, Zhenxin; Han, Eunjung; Hou, Rong; Zhang, Liang; Galaverni, Marco; Huang, Jie; Liu, Hong; Silva, Pedro; Li, Peng; Pollinger, John P; Du, Lianming; Zhang, XiuyYue; Yue, Bisong; Wayne, Robert K; Zhang, Zhihe

2014-07-01

The Tibetan grey wolf (Canis lupus chanco) occupies habitats on the Qinghai-Tibet Plateau, a high altitude (>3000 m) environment where low oxygen tension exerts unique selection pressure on individuals to adapt to hypoxic conditions. To identify genes involved in hypoxia adaptation, we generated complete genome sequences of nine Chinese wolves from high and low altitude populations at an average coverage of 25× coverage. We found that, beginning about 55,000 years ago, the highland Tibetan grey wolf suffered a more substantial population decline than lowland wolves. Positively selected hypoxia-related genes in highland wolves are enriched in the HIF signaling pathway (P = 1.57E-6), ATP binding (P = 5.62E-5), and response to an oxygen-containing compound (P≤5.30E-4). Of these positively selected hypoxia-related genes, three genes (EPAS1, ANGPT1, and RYR2) had at least one specific fixed non-synonymous SNP in highland wolves based on the nine genome data. Our re-sequencing studies on a large panel of individuals showed a frequency difference greater than 58% between highland and lowland wolves for these specific fixed non-synonymous SNPs and a high degree of LD surrounding the three genes, which imply strong selection. Past studies have shown that EPAS1 and ANGPT1 are important in the response to hypoxic stress, and RYR2 is involved in heart function. These three genes also exhibited significant signals of natural selection in high altitude human populations, which suggest similar evolutionary constraints on natural selection in wolves and humans of the Qinghai-Tibet Plateau.

Specific elimination of CD133+ tumor cells with targeted oncolytic measles virus.

PubMed

Bach, Patricia; Abel, Tobias; Hoffmann, Christopher; Gal, Zoltan; Braun, Gundula; Voelker, Iris; Ball, Claudia R; Johnston, Ian C D; Lauer, Ulrich M; Herold-Mende, Christel; Mühlebach, Michael D; Glimm, Hanno; Buchholz, Christian J

2013-01-15

Tumor-initiating cells (TIC) are critical yet evasive targets for the development of more effective antitumoral strategies. The cell surface marker CD133 is frequently used to identify TICs of various tumor entities, including hepatocellular cancer and glioblastoma. Here, we describe oncolytic measles viruses (MV) retargeted to CD133. The viruses, termed MV-141.7 and MV-AC133, infected and selectively lysed CD133(+) tumor cells. Both viruses exerted strong antitumoral effects on human hepatocellular carcinoma growing subcutaneously or multifocally in the peritoneal cavity of nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Notably, the CD133-targeted viruses were more effective in prolonging survival than the parental MV-NSe, which is currently assessed as oncolytic agent in clinical trials. Interestingly, target receptor overexpression or increased spreading kinetics through tumor cells were excluded as being causative for the enhanced oncolytic activity of CD133-targeted viruses. MV-141.7 was also effective in mouse models of orthotopic glioma tumor spheres and primary colon cancer. Our results indicate that CD133-targeted measles viruses selectively eliminate CD133(+) cells from tumor tissue, offering a key tool for research in tumor biology and cancer therapy.

Mutual Mate Choice: When it Pays Both Sexes to Avoid Inbreeding

PubMed Central

Lihoreau, Mathieu; Zimmer, Cédric; Rivault, Colette

2008-01-01

Theoretical models of sexual selection predict that both males and females of many species should benefit by selecting their mating partners. However, empirical evidence testing and validating this prediction is scarce. In particular, whereas inbreeding avoidance is expected to induce sexual conflicts, in some cases both partners could benefit by acting in concert and exerting mutual mate choice for non-assortative pairings. We tested this prediction with the gregarious cockroach Blattella germanica (L.). We demonstrated that males and females base their mate choice on different criteria and that choice occurs at different steps during the mating sequence. Males assess their relatedness to females through antennal contacts before deciding to court preferentially non-siblings. Conversely, females biased their choice towards the most vigorously courting males that happened to be non-siblings. This study is the first to demonstrate mutual mate choice leading to close inbreeding avoidance. The fact that outbred pairs were more fertile than inbred pairs strongly supports the adaptive value of this mating system, which includes no “best phenotype” as the quality of two mating partners is primarily linked to their relatedness. We discuss the implications of our results in the light of inbreeding conflict models. PMID:18843373

Mutual mate choice: when it pays both sexes to avoid inbreeding.

PubMed

Lihoreau, Mathieu; Zimmer, Cédric; Rivault, Colette

2008-01-01

Theoretical models of sexual selection predict that both males and females of many species should benefit by selecting their mating partners. However, empirical evidence testing and validating this prediction is scarce. In particular, whereas inbreeding avoidance is expected to induce sexual conflicts, in some cases both partners could benefit by acting in concert and exerting mutual mate choice for non-assortative pairings. We tested this prediction with the gregarious cockroach Blattella germanica (L.). We demonstrated that males and females base their mate choice on different criteria and that choice occurs at different steps during the mating sequence. Males assess their relatedness to females through antennal contacts before deciding to court preferentially non-siblings. Conversely, females biased their choice towards the most vigorously courting males that happened to be non-siblings. This study is the first to demonstrate mutual mate choice leading to close inbreeding avoidance. The fact that outbred pairs were more fertile than inbred pairs strongly supports the adaptive value of this mating system, which includes no "best phenotype" as the quality of two mating partners is primarily linked to their relatedness. We discuss the implications of our results in the light of inbreeding conflict models.

Selective mode excitation in finite size plasma crystals by diffusely reflected laser light

NASA Astrophysics Data System (ADS)

Schablinski, Jan; Block, Dietmar

2015-02-01

The possibility to use diffuse reflections of a laser beam to exert a force on levitating dust particles is studied experimentally. Measurements and theoretical predictions are found to be in good agreement. Further, the method is applied to test the selective excitation of breathing-like modes in finite dust clusters.

Anticancer potential of new steroidal thiazolidin-4-one derivatives. Mechanisms of cytotoxic action and effects on angiogenesis in vitro.

PubMed

Živković, Marijana B; Matić, Ivana Z; Rodić, Marko V; Novaković, Irena T; Krivokuća, Ana M; Sladić, Dušan M; Krstić, Natalija M

2017-11-01

The synthesis and cytotoxic activities determination of new steroidal mono- and bis(thiazolidin-4-ones) 4a-f and 5a-f have been performed. Their anticancer action was also evaluated in comparison to previously synthesized and reported corresponding steroidal thiosemicarbazones. All compounds were obtained as stereoisomeric mixtures with different configuration (E or Z) in the hydrazone moiety at the C-3 position. After several consecutive crystallizations diastereomerically pure major (E)-isomers of mono-thiazolidin-4-ones were isolated. The structure and stereochemistry of 2,4-thiazolidinedione,2-[(17-oxoandrost-4-en-3-ylidene)hydrazone] were confirmed by X-ray analysis. A pathway for the formation of thiazolidin-4-one ring was proposed. The steroid thiazolidinone derivatives examined in this study exerted selective concentration-dependent cytotoxic activities on six tested malignant cell lines. Ten out of twelve examined compounds exhibited strong cytotoxic effects on K562 cells (IC 50 values from 8.5μM to 14.9μM), eight on HeLa cells (IC 50 values ranging from 8.9μM to 15.1μM) while against MDA-MB-361 cells six compouds exerted similar or even higher cytotoxic action (IC 50 values from 12.7μM to 25.6μM) than cisplatin (21.5μM) which served as a positive control. Eight of these ten compounds showed high selectivity in the cytotoxic action against HeLa and K562 cancer cell lines when compared with normal human fibroblasts MRC-5 and normal human PBMC. The study of mechanisms of the anticancer activity of the two selected compounds, mono- and bis(thiazolidin-4-one) derivatives of 19-norandrost-4-ene-3,17-dione 4a and 5a, revealed that both of these compounds induced apoptosis in HeLa cells through extrinsic and intrinsic signalling pathways. Treatment of EA.hy926 cells with sub-toxic concentrations of these compounds led to the inhibition of cell connecting and sprouting, and tube formation. The synthesized compounds exhibited poor antioxidant activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selective pressure of antibiotic pollution on bacteria of importance to public health.

PubMed

Tello, Alfredo; Austin, Brian; Telfer, Trevor C

2012-08-01

Many bacteria of clinical importance survive and may grow in different environments. Antibiotic pollution may exert on them a selective pressure leading to an increase in the prevalence of resistance. In this study we sought to determine whether environmental concentrations of antibiotics and concentrations representing action limits used in environmental risk assessment may exert a selective pressure on clinically relevant bacteria in the environment. We used bacterial inhibition as an assessment end point to link antibiotic selective pressures to the prevalence of resistance in bacterial populations. Species sensitivity distributions were derived for three antibiotics by fitting log-logistic models to end points calculated from minimum inhibitory concentration (MIC) distributions based on worldwide data collated by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). To place bacteria represented in these distributions in a broader context, we performed a brief phylogenetic analysis. The potentially affected fraction of bacterial genera at measured environmental concentrations of antibiotics and environmental risk assessment action limits was used as a proxy for antibiotic selective pressure. Measured environmental concentrations and environmental risk assessment action limits were also directly compared to wild-type cut-off values. The potentially affected fraction of bacterial genera estimated based on antibiotic concentrations measured in water environments is ≤ 7%. We estimated that measured environmental concentrations in river sediments, swine feces lagoons, liquid manure, and farmed soil inhibit wild-type populations in up to 60%, 92%, 100%, and 30% of bacterial genera, respectively. At concentrations used as action limits in environmental risk assessment, erythromycin and ciprofloxacin were estimated to inhibit wild-type populations in up to 25% and 76% of bacterial genera. Measured environmental concentrations of antibiotics, as well as concentrations representing environmental risk assessment action limits, are high enough to exert a selective pressure on clinically relevant bacteria that may lead to an increase in the prevalence of resistance.

The Turbulent Field of Public School Administration.

ERIC Educational Resources Information Center

Conners, Dennis A.; Reed, Donald B.

1983-01-01

Business and industry have exerted a strong influence on public schools and school administration, especially on assumptions about the school setting and its implications for administrator behavior. Schools have been assumed to be bureaucratic organizations in a stable environment, which implies that administrators should be leaders in…

Polarity governed selective amplification of through plane proton shuttling in proton exchange membrane fuel cells.

PubMed

Gautam, Manu; Chattanahalli Devendrachari, Mruthyunjayachari; Thimmappa, Ravikumar; Raja Kottaichamy, Alagar; Pottachola Shafi, Shahid; Gaikwad, Pramod; Makri Nimbegondi Kotresh, Harish; Ottakam Thotiyl, Musthafa

2017-03-15

Graphene oxide (GO) anisotropically conducts protons with directional dominance of in plane ionic transport (σ IP) over the through plane (σ TP). In a typical H 2 -O 2 fuel cell, since the proton conduction occurs through the plane during its generation at the fuel electrode, it is indeed inevitable to selectively accelerate GO's σ TP for advancement towards a potential fuel cell membrane. We successfully achieved ∼7 times selective amplification of GO's σ TP by tuning the polarity of the dopant molecule in its nanoporous matrix. The coexistence of strongly non-polar and polar domains in the dopant demonstrated a synergistic effect towards σ TP with the former decreasing the number of water molecules coordinated to protons by ∼3 times, diminishing the effects of electroosmotic drag exerted on ionic movements, and the latter selectively accelerating σ TP across the catalytic layers by bridging the individual GO planes via extensive host guest H-bonding interactions. When they are decoupled, the dopant with mainly non-polar or polar features only marginally enhances the σ TP, revealing that polarity factors contribute to fuel cell relevant transport properties of GO membranes only when they coexist. Fuel cell polarization and kinetic analyses revealed that these multitask dopants increased the fuel cell performance metrics of the power and current densities by ∼3 times compared to the pure GO membranes, suggesting that the functional group factors of the dopants are of utmost importance in GO-based proton exchange membrane fuel cells.

Selection of Sphingomonadaceae at the base of Laccaria proxima and Russula exalbicans fruiting bodies.

PubMed

Boersma, F G Hidde; Warmink, Jan A; Andreote, Fernando A; van Elsas, Jan Dirk

2009-04-01

The dense hyphal network directly underneath the fruiting bodies of ectomycorrhizal fungi might exert strong influences on the bacterial community of soil. Such fruiting bodies might serve as hot spots for bacterial activity, for instance by providing nutrients and colonization sites in soil. Here, we assessed the putative selection of specific members of the Sphingomonadaceae family at the bases of the fruiting bodies of the ectomycorrhizal fungi Laccaria proxima and Russula exalbicans in comparison to the adjacent bulk soil. To do so, we used a previously designed Sphingomonadaceae-specific PCR-denaturing gradient gel electrophoresis (DGGE) system and complemented this with analyses of sequences from a Sphingomonadaceae-specific clone library. The analyses showed clear selective effects of the fruiting bodies of both fungi on the Sphingomonadaceae community structures. The effect was especially prevalent with R. exalbicans. Strikingly, similar fungi sampled approximately 100 m apart showed similar DGGE patterns, while corresponding bulk soil-derived patterns differed from each other. However, the mycospheres of L. proxima and R. exalbicans still revealed divergent community structures, indicating that different fungi select for different members of the Sphingomonadaceae family. Excision of specific bands from the DGGE patterns, as well as analyses of the clone libraries generated from both habitats, revealed fruiting body-specific Sphingomonadaceae types. It further showed that major groups from the mycospheres of R. exalbicans and L. proxima did not cluster with known bacteria from the database, indicating new groups within the family of Sphingomonadaceae present in these environments.

Eliminating Survivor Bias in Two-stage Instrumental Variable Estimators.

PubMed

Vansteelandt, Stijn; Walter, Stefan; Tchetgen Tchetgen, Eric

2018-07-01

Mendelian randomization studies commonly focus on elderly populations. This makes the instrumental variables analysis of such studies sensitive to survivor bias, a type of selection bias. A particular concern is that the instrumental variable conditions, even when valid for the source population, may be violated for the selective population of individuals who survive the onset of the study. This is potentially very damaging because Mendelian randomization studies are known to be sensitive to bias due to even minor violations of the instrumental variable conditions. Interestingly, the instrumental variable conditions continue to hold within certain risk sets of individuals who are still alive at a given age when the instrument and unmeasured confounders exert additive effects on the exposure, and moreover, the exposure and unmeasured confounders exert additive effects on the hazard of death. In this article, we will exploit this property to derive a two-stage instrumental variable estimator for the effect of exposure on mortality, which is insulated against the above described selection bias under these additivity assumptions.

Chemical probes to potently and selectively inhibit endocannabinoid cellular reuptake.

PubMed

Chicca, Andrea; Nicolussi, Simon; Bartholomäus, Ruben; Blunder, Martina; Aparisi Rey, Alejandro; Petrucci, Vanessa; Reynoso-Moreno, Ines Del Carmen; Viveros-Paredes, Juan Manuel; Dalghi Gens, Marianela; Lutz, Beat; Schiöth, Helgi B; Soeberdt, Michael; Abels, Christoph; Charles, Roch-Philippe; Altmann, Karl-Heinz; Gertsch, Jürg

2017-06-20

The extracellular effects of the endocannabinoids anandamide and 2-arachidonoyl glycerol are terminated by enzymatic hydrolysis after crossing cellular membranes by facilitated diffusion. The lack of potent and selective inhibitors for endocannabinoid transport has prevented the molecular characterization of this process, thus hindering its biochemical investigation and pharmacological exploitation. Here, we report the design, chemical synthesis, and biological profiling of natural product-derived N -substituted 2,4-dodecadienamides as a selective endocannabinoid uptake inhibitor. The highly potent (IC 50 = 10 nM) inhibitor N -(3,4-dimethoxyphenyl)ethyl amide (WOBE437) exerted pronounced cannabinoid receptor-dependent anxiolytic, antiinflammatory, and analgesic effects in mice by increasing endocannabinoid levels. A tailored WOBE437-derived diazirine-containing photoaffinity probe (RX-055) irreversibly blocked membrane transport of both endocannabinoids, providing mechanistic insights into this complex process. Moreover, RX-055 exerted site-specific anxiolytic effects on in situ photoactivation in the brain. This study describes suitable inhibitors to target endocannabinoid membrane trafficking and uncovers an alternative endocannabinoid pharmacology.

Measurement and Modeling of Electromagnetic Scattering by Particles and Particle Groups. Chapter 3

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.

2015-01-01

Small particles forming clouds of interstellar and circumstellar dust, regolith surfaces of many solar system bodies, and cometary atmospheres have a strong and often controlling effect on many ambient physical and chemical processes. Similarly, aerosol and cloud particles exert a strong influence on the regional and global climates of the Earth, other planets of the solar system, and exoplanets. Therefore, detailed and accurate knowledge of physical and chemical characteristics of such particles has the utmost scientific importance.

Effectiveness and feasibility of virtual reality and gaming system use at home by older adults for enabling physical activity to improve health-related domains: a systematic review.

PubMed

Miller, Kimberly J; Adair, Brooke S; Pearce, Alan J; Said, Catherine M; Ozanne, Elizabeth; Morris, Meg M

2014-03-01

use of virtual reality and commercial gaming systems (VR/gaming) at home by older adults is receiving attention as a means of enabling physical activity. to summarise evidence for the effectiveness and feasibility of VR/gaming system utilisation by older adults at home for enabling physical activity to improve impairments, activity limitations or participation. a systematic review searching 12 electronic databases from 1 January 2000-10 July 2012 using key search terms. Two independent reviewers screened yield articles using pre-determined selection criteria, extracted data using customised forms and applied the Cochrane Collaboration Risk of Bias Tool and the Downs and Black Checklist to rate study quality. fourteen studies investigating the effects of VR/gaming system use by healthy older adults and people with neurological conditions on activity limitations, body functions and physical impairments and cognitive and emotional well-being met the selection criteria. Study quality ratings were low and, therefore, evidence was not strong enough to conclude that interventions were effective. Feasibility was inconsistently reported in studies. Where feasibility was discussed, strong retention (≥70%) and adherence (≥64%) was reported. Initial assistance to use the technologies, and the need for monitoring exertion, aggravation of musculoskeletal symptoms and falls risk were reported. existing evidence to support the feasibility and effectiveness VR/gaming systems use by older adults at home to enable physical activity to address impairments, activity limitations and participation is weak with a high risk of bias. The findings of this review may inform future, more rigorous research.

Exertional Tolerance Assessments After Mild Traumatic Brain Injury: A Systematic Review.

PubMed

Quatman-Yates, Catherine; Bailes, Anna; Constand, Sara; Sroka, Mary Claire; Nissen, Katharine; Kurowski, Brad; Hugentobler, Jason

2018-05-01

To review the literature to identify and summarize strategies for evaluating responses to physical exertion after mild traumatic brain injury (mTBI) for clinical and research purposes. PubMed and EBSCOhost through December 31, 2016. Two independent reviewers selected studies based on the following criteria: (1) inclusion of participants with mTBI/concussion, (2) use of a measurement of physiological or psychosomatic response to exertion, (3) a repeatable description of the exertion protocol was provided, (4) a sample of at least 10 participants with a mean age between 8 and 65 years, and (5) the article was in English. The search process yielded 2685 articles, of which 14 studies met the eligibility requirements. A quality assessment using a checklist was conducted for each study by 2 independent study team members and verified by a third team member. Data were extracted by one team member and verified by a second team member. A qualitative synthesis of the studies revealed that most protocols used a treadmill or cycle ergometer as the exercise modality. Protocol methods varied across studies including differences in initial intensity determination, progression parameters, and exertion duration. Common outcome measures were self-reported symptoms, heart rate, and blood pressure. The strongest evidence indicates that exertional assessments can provide important insight about mTBI recovery and should be administered using symptoms as a guide. Additional studies are needed to verify optimal modes and protocols for post-mTBI exertional assessments. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Wild ungulate herbivory suppresses deciduous woody plant establishment following salmonid stream restoration

Treesearch

Joshua P. Averett; Bryan A. Endress; Mary M. Rowland; Bridgett J. Naylor; Michael J. Wisdom

2017-01-01

Domestic and wild ungulates can exert strong influences on riparian woody vegetation establishment, yet little is known about how wild ungulate herbivory affects riparian restoration in the absence of cattle. We evaluated elk (Cervus elaphus) and mule deer (Odocoileus hemionus) impacts on the establishment of deciduous woody...

A Priori Knowledge and Heuristic Reasoning in Architectural Design.

ERIC Educational Resources Information Center

Rowe, Peter G.

1982-01-01

It is proposed that the various classes of a priori knowledge incorporated in heuristic reasoning processes exert a strong influence over architectural design activity. Some design problems require exercise of some provisional set of rules, inference, or plausible strategy which requires heuristic reasoning. A case study illustrates this concept.…

Utopian Visions: Promise and Pitfalls in the Global Awareness of the Gifted

ERIC Educational Resources Information Center

Ambrose, Don

2008-01-01

Utopian thinking has captured the human imagination for millennia and has exerted strong influences on societies--in particular, on their socioeconomic, political, and cultural dimensions of societies. Consequently, enhancement of global awareness requires attention to utopian frameworks, especially when those frameworks are influencing the…

Knowledge Organization and the Acquisition of Procedural Expertise.

DTIC Science & Technology

1987-10-01

NO NO ACCESSION NO 11i TITLE (InCludf S#cufltY Cissjf)CAtl~on) KOWLEDGE ORGANIZATION AND THE ACQUISITION OF PROCEDURAL EXPERTISE 12 PERSONAL AUTI󈧬R...explanatory material strongly influences the knowledge representation of the learner which, in turn, exerts a powerful influence over the degree to which

Media/Visual Literacy Art Education: Cigarette Ad Deconstruction

ERIC Educational Resources Information Center

Chung, Sheng Kuan

2005-01-01

Visual images are not simply embodiments of social reality; they are indeed ideological sites embedded with powerful discursive sociopolitical meanings that exert strong influences on the ways in which people live their lives. The author of this paper describes the Ad-Deconstruction Project, which challenged students to integrate aesthetic…

Postsecondary Education Persistence of Adolescents with Specific Learning Disabilities or Emotional/Behavioral Disorders

ERIC Educational Resources Information Center

Lee, In Heok; Rojewski, Jay W.; Gregg, Noel; Jeong, Seok-Oh

2015-01-01

While experiences of students with disabilities transitioning from high school to college have been well documented, the influence exerted by selected factors on these experiences is less well understood. Using data from the Education Longitudinal Study of 2002, the influence of selected risk and resilience factors on the short-term postsecondary…

Selective attention in peacocks during predator detection.

PubMed

Yorzinski, Jessica L; Platt, Michael L

2014-05-01

Predation can exert strong selective pressure on the evolution of behavioral and morphological traits in birds. Because predator avoidance is key to survival and birds rely heavily on visual perception, predation may have shaped avian visual systems as well. To address this question, we examined the role of visual attention in antipredator behavior in peacocks (Pavo cristatus). Peacocks were exposed to a model predator while their gaze was continuously recorded with a telemetric eye-tracker. We found that peacocks spent more time looking at and made more fixations on the predator compared to the same spatial location before the predator was revealed. The duration of fixations they directed toward conspecifics and environmental features decreased after the predator was revealed, indicating that the peacocks were rapidly scanning their environment with their eyes. Maximum eye movement amplitudes and amplitudes of consecutive saccades were similar before and after the predator was revealed. In cases where conspecifics detected the predator first, peacocks appeared to learn that danger was present by observing conspecifics' antipredator behavior. Peacocks were faster to detect the predator when they were fixating closer to the area where the predator would eventually appear. In addition, pupil size increased after predator exposure, consistent with increased physiological arousal. These findings demonstrate that peacocks selectively direct their attention toward predatory threats and suggest that predation has influenced the evolution of visual orienting systems.

A depauperate immune repertoire precedes evolution of sociality in bees.

PubMed

Barribeau, Seth M; Sadd, Ben M; du Plessis, Louis; Brown, Mark J F; Buechel, Severine D; Cappelle, Kaat; Carolan, James C; Christiaens, Olivier; Colgan, Thomas J; Erler, Silvio; Evans, Jay; Helbing, Sophie; Karaus, Elke; Lattorff, H Michael G; Marxer, Monika; Meeus, Ivan; Näpflin, Kathrin; Niu, Jinzhi; Schmid-Hempel, Regula; Smagghe, Guy; Waterhouse, Robert M; Yu, Na; Zdobnov, Evgeny M; Schmid-Hempel, Paul

2015-04-24

Sociality has many rewards, but can also be dangerous, as high population density and low genetic diversity, common in social insects, is ideal for parasite transmission. Despite this risk, honeybees and other sequenced social insects have far fewer canonical immune genes relative to solitary insects. Social protection from infection, including behavioral responses, may explain this depauperate immune repertoire. Here, based on full genome sequences, we describe the immune repertoire of two ecologically and commercially important bumblebee species that diverged approximately 18 million years ago, the North American Bombus impatiens and European Bombus terrestris. We find that the immune systems of these bumblebees, two species of honeybee, and a solitary leafcutting bee, are strikingly similar. Transcriptional assays confirm the expression of many of these genes in an immunological context and more strongly in young queens than males, affirming Bateman's principle of greater investment in female immunity. We find evidence of positive selection in genes encoding antiviral responses, components of the Toll and JAK/STAT pathways, and serine protease inhibitors in both social and solitary bees. Finally, we detect many genes across pathways that differ in selection between bumblebees and honeybees, or between the social and solitary clades. The similarity in immune complement across a gradient of sociality suggests that a reduced immune repertoire predates the evolution of sociality in bees. The differences in selection on immune genes likely reflect divergent pressures exerted by parasites across social contexts.

Mechanistic Peptidomics: Factors That Dictate Specificity in the Formation of Endogenous Peptides in Human Milk*

PubMed Central

Guerrero, Andres; Dallas, David C.; Contreras, Stephanie; Chee, Sabrina; Parker, Evan A.; Sun, Xin; Dimapasoc, Lauren; Barile, Daniela; German, J. Bruce; Lebrilla, Carlito B.

2014-01-01

An extensive mass spectrometry analysis of the human milk peptidome has revealed almost 700 endogenous peptides from 30 different proteins. Two in-house computational tools were created and used to visualize and interpret the data through both alignment of the peptide quasi-molecular ion intensities and estimation of the differential enzyme participation. These results reveal that the endogenous proteolytic activity in the mammary gland is remarkably specific and well conserved. Certain proteins—not necessarily the most abundant ones—are digested by the proteases present in milk, yielding endogenous peptides from selected regions. Our results strongly suggest that factors such as the presence of specific proteases, the position and concentration of cleavage sites, and, more important, the intrinsic disorder of segments of the protein drive this proteolytic specificity in the mammary gland. As a consequence of this selective hydrolysis, proteins that typically need to be cleaved at specific positions in order to exert their activity are properly digested, and bioactive peptides encoded in certain protein sequences are released. Proteins that must remain intact in order to maintain their activity in the mammary gland or in the neonatal gastrointestinal tract are unaffected by the hydrolytic environment present in milk. These results provide insight into the intrinsic structural mechanisms that facilitate the selectivity of the endogenous milk protease activity and might be useful to those studying the peptidomes of other biofluids. PMID:25172956

Interest Group Conflict Over Medicaid Expansion: The Surprising Impact of Public Advocates.

PubMed

Callaghan, Timothy; Jacobs, Lawrence R

2016-02-01

We examined the potential economic, policy, and political influences on the decisions of the 50 US states to expand Medicaid under the Affordable Care Act. We related a measure of relative state progress toward Medicaid expansion updated to 2015 to each state's economic circumstances, established policy frameworks in states, partisan control of state government, and lobbyists for businesses, medical professionals, unions, and public interest organizations. The 9201 lobbyists working on health care reform in state capitols exerted a strong and significant impact on Medicaid expansion. Controlling for confounding factors (including partisanship and existing policy frameworks), we found that business and professional lobbyists exerted a negative effect on state Medicaid expansion and, unexpectedly, that public interest advocates exerted a positive effect. There are 3.1 million adults who lack coverage because they live in the 20 states that refused to expand Medicaid. Although political party and lobbyists for private interests present significant barriers in these states, legislative lobbying on behalf of the uninsured appears likely to be effective.

Development of the color scale of perceived exertion: preliminary validation.

PubMed

Serafim, Thais H S; Tognato, Andrea C; Nakamura, Priscila M; Queiroga, Marcos R; Nakamura, Fábio Y; Pereira, Gleber; Kokubun, Eduardo

2014-12-01

This study developed a Color Scale of Perceived Exertion (RPE-color scale) and assessed its concurrent and construct validity in adult women. One hundred participants (18-77 years), who were habitual exercisers, associated colors with verbal anchors of the Borg RPE scale (RPE-Borg scale) for RPE-color scale development. For RPE-color scale validation, 12 Young (M = 21.7 yr., SD = 1.5) and 10 Older (M = 60.3 yr., SD = 3.5) adult women performed a maximal graded exercise test on a treadmill and reported perceived exertion in both RPE-color and RPE-Borg scales. In the Young group, the RPE-color scale was significantly associated with heart rate and oxygen consumption, having strong correlations with the RPE-Borg scale. In the Older group, the RPE-color scale was significantly associated with heart rate, having moderate to high correlations with the RPE-Borg scale. The RPE-color scale demonstrated concurrent and construct validity in the Young women, as well as construct validity in Older adults.

Collaborative Research: Fundamental studies of plasma control using surface embedded electronic devices

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

Raja, Laxminarayan L.; PanneerChelvam, PremKumar; Levko, Dimtry

2016-02-26

The proposed study will investigate the effect of active electron injection of from electrode surfaces To the best of our knowledge, no such a study has ever been attempted even though it could lead to the formation of whole new classes of plasma based devices and systems. We are motivated by recent articles and simple theory which gives strong reason to believe that embedded electronic devices can be used to exert control over the SEE coefficient of semiconductor surfaces (and maybe other surface types as well). Furthermore, the research will explore how such sub-surface electronic devices can best be usedmore » to exert control over an associated plasma.« less

Cell Extrusion: A Stress-Responsive Force for Good or Evil in Epithelial Homeostasis.

PubMed

Ohsawa, Shizue; Vaughen, John; Igaki, Tatsushi

2018-02-05

Epithelial tissues robustly respond to internal and external stressors via dynamic cellular rearrangements. Cell extrusion acts as a key regulator of epithelial homeostasis by removing apoptotic cells, orchestrating morphogenesis, and mediating competitive cellular battles during tumorigenesis. Here, we delineate the diverse functions of cell extrusion during development and disease. We emphasize the expanding role for apoptotic cell extrusion in exerting morphogenetic forces, as well as the strong intersection of cell extrusion with cell competition, a homeostatic mechanism that eliminates aberrant or unfit cells. While cell competition and extrusion can exert potent, tumor-suppressive effects, dysregulation of either critical homeostatic program can fuel cancer progression. Copyright © 2018 Elsevier Inc. All rights reserved.

Coexistence of two electronic phases in LaTiO3+δ (0.01⩽δ⩽0.12) and their evolution with δ

NASA Astrophysics Data System (ADS)

Zhou, H. D.; Goodenough, J. B.

2005-04-01

Although LaTiO3+δ(0.01⩽δ⩽0.12) is single-phase to powder x-ray diffraction, its properties reveal that a hole-poor strongly correlated electronic phase coexists with a hole-rich itinerant-electron phase. With δ⩽0.03 , the hole-rich phase exists as a minority phase of isolated, mobile itinerant-electron clusters embedded in the hole-poor phase. With δ⩾0.08 , isolated hole-poor clusters are embedded in an itinerant-electron matrix. As δ>0.08 increases, the hole-poor clusters become smaller and more isolated until they are reduced to superparamagnetic strong-correlation fluctuations by δ=0.12 . This behavior is consistent with prediction from the virial theorem of a first-order phase change at the crossover from localized (or strongly correlated) to itinerant electronic behavior, a smaller equilibrium (Ti-O) bond length being in the itinerant-electron phase. Accordingly, the variation of volume with oxidation state does not obey Végard’s law; the itinerant-electron minority phase exerts a compressive force on the hole-poor matrix, and the hole-poor minority phase exerts a tensile stress on the hole-rich matrix.

Mechanism of inhibition of adenovirus DNA replication by the acyclic nucleoside triphosphate analogue (S)-HPMPApp: influence of the adenovirus DNA binding protein.

PubMed Central

Mul, Y M; van Miltenburg, R T; De Clercq, E; van der Vliet, P C

1989-01-01

The acyclic adenosine analogue (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [S]-HPMPA) is a potent and selective inhibitor of adenovirus (Ad) replication in cell culture. We studied the mechanism of inhibition using a reconstituted in vitro DNA replication system. The diphosphoryl derivative (S)-HPMPApp, but not (S)-HPMPA, inhibited the DNA replication of origin containing fragments strongly. The inhibitory effect was exerted at the level of elongation, while initiation was resistant to the drug. Remarkably, the elongation of short strands was only slightly impaired, while inhibition was maximal upon synthesis of long DNA fragments. (S)-HPMPApp appeared to be competitive with dATP, suggesting that the Ad DNA polymerase is the prime target for the drug. We purified the Ad DNA polymerase in complex to the precursor terminal protein to homogeneity from cells infected with overproducing recombinant vaccinia viruses. Employing gapped DNA or poly(dT).oligo(dA) templates, only a weak inhibition was observed. However, inhibition was strongly enhanced in the presence of the adenovirus DNA binding protein (DBP). We interpret this to mean that the increased processivity of the polymerization reaction in the presence of DBP leads to increased drug sensitivity. Images PMID:2587248

Drum ring removal/installation tool

DOEpatents

Andrade, William Andrew [Livermore, CA

2006-11-14

A handheld tool, or a pair of such tools, such as for use in removing/installing a bolt-type clamping ring on a container barrel/drum, where the clamping ring has a pair of clamping ends each with a throughbore. Each tool has an elongated handle and an elongated lever arm transversely connected to one end of the handle. The lever arm is capable of being inserted into the throughbore of a selected clamping end and leveraged with the handle to exert a first moment on the selected clamping end. Each tool also has a second lever arm, such as a socket with an open-ended slot, which is suspended alongside the first lever arm. The second lever arm is capable of engaging the selected clamping end and being leveraged with the handle to exert a second moment which is orthogonal to the first moment. In this manner, the first and second moments operate to hold the selected clamping end fixed relative to the tool so that the selected clamping end may be controlled with the handle. The pair of clamping ends may also be simultaneously and independently controlled with the use of two handles/tools so as to contort the geometry of the drum clamping ring and enable its removal/installation.

Selective deficit in personal moral judgment following damage to ventromedial prefrontal cortex.

PubMed

Ciaramelli, Elisa; Muccioli, Michela; Làdavas, Elisabetta; di Pellegrino, Giuseppe

2007-06-01

Recent fMRI evidence has detected increased medial prefrontal activation during contemplation of personal moral dilemmas compared to impersonal ones, which suggests that this cortical region plays a role in personal moral judgment. However, functional imaging results cannot definitively establish that a brain area is necessary for a particular cognitive process. This requires evidence from lesion techniques, such as studies of human patients with focal brain damage. Here, we tested 7 patients with lesions in the ventromedial prefrontal cortex and 12 healthy individuals in personal moral dilemmas, impersonal moral dilemmas and non-moral dilemmas. Compared to normal controls, patients were more willing to judge personal moral violations as acceptable behaviors in personal moral dilemmas, and they did so more quickly. In contrast, their performance in impersonal and non-moral dilemmas was comparable to that of controls. These results indicate that the ventromedial prefrontal cortex is necessary to oppose personal moral violations, possibly by mediating anticipatory, self-focused, emotional reactions that may exert strong influence on moral choice and behavior.

Engineering a therapeutic lectin by uncoupling mitogenicity from antiviral activity.

PubMed

Swanson, Michael D; Boudreaux, Daniel M; Salmon, Loïc; Chugh, Jeetender; Winter, Harry C; Meagher, Jennifer L; André, Sabine; Murphy, Paul V; Oscarson, Stefan; Roy, René; King, Steven; Kaplan, Mark H; Goldstein, Irwin J; Tarbet, E Bart; Hurst, Brett L; Smee, Donald F; de la Fuente, Cynthia; Hoffmann, Hans-Heinrich; Xue, Yi; Rice, Charles M; Schols, Dominique; Garcia, J Victor; Stuckey, Jeanne A; Gabius, Hans-Joachim; Al-Hashimi, Hashim M; Markovitz, David M

2015-10-22

A key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino-acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity, while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity, while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code. Copyright © 2015 Elsevier Inc. All rights reserved.

The evolutionary psychology of women's aggression.

PubMed

Campbell, Anne

2013-01-01

Evolutionary researchers have identified age, operational sex ratio and high variance in male resources as factors that intensify female competition. These are discussed in relation to escalated intrasexual competition for men and their resources between young women in deprived neighbourhoods. For these women, fighting is not seen as antithetical to cultural conceptions of femininity, and female weakness is disparaged. Nonetheless, even where competitive pressures are high, young women's aggression is less injurious and frequent than young men's. From an evolutionary perspective, I argue that the intensity of female aggression is constrained by the greater centrality of mothers, rather than fathers, to offspring survival. This selection pressure is realized psychologically through a lower threshold for fear among women. Neuropsychological evidence is not yet conclusive but suggests that women show heightened amygdala reactivity to threatening stimuli, may be better able to exert prefrontal cortical control over emotional behaviour and may consciously register fear more strongly via anterior cingulate activity. The impact of testosterone and oxytocin on the neural circuitry of emotion is also considered.

Engineering a Therapeutic Lectin by Uncoupling Mitogenicity from Antiviral Activity

PubMed Central

Swanson, Michael D.; Boudreaux, Daniel M.; Salmon, Loïc; Chugh, Jeetender; Winter, Harry C.; Meagher, Jennifer L.; André, Sabine; Murphy, Paul V.; Oscarson, Stefan; Roy, René; King, Steven; Kaplan, Mark H.; Goldstein, Irwin J.; Tarbet, E. Bart; Hurst, Brett L.; Smee, Donald F.; de la Fuente, Cynthia; Hoffmann, Hans-Heinrich; Xue, Yi; Rice, Charles M.; Schols, Dominique; Garcia, J. Victor; Stuckey, Jeanne A.; Gabius, Hans-Joachim; Al-Hashimi, Hashim M.; Markovitz, David M.

2015-01-01

Summary A key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code. PMID:26496612

Inference of tumor evolution during chemotherapy by computational modeling and in situ analysis of genetic and phenotypic cellular diversity.

PubMed

Almendro, Vanessa; Cheng, Yu-Kang; Randles, Amanda; Itzkovitz, Shalev; Marusyk, Andriy; Ametller, Elisabet; Gonzalez-Farre, Xavier; Muñoz, Montse; Russnes, Hege G; Helland, Aslaug; Rye, Inga H; Borresen-Dale, Anne-Lise; Maruyama, Reo; van Oudenaarden, Alexander; Dowsett, Mitchell; Jones, Robin L; Reis-Filho, Jorge; Gascon, Pere; Gönen, Mithat; Michor, Franziska; Polyak, Kornelia

2014-02-13

Cancer therapy exerts a strong selection pressure that shapes tumor evolution, yet our knowledge of how tumors change during treatment is limited. Here, we report the analysis of cellular heterogeneity for genetic and phenotypic features and their spatial distribution in breast tumors pre- and post-neoadjuvant chemotherapy. We found that intratumor genetic diversity was tumor-subtype specific, and it did not change during treatment in tumors with partial or no response. However, lower pretreatment genetic diversity was significantly associated with pathologic complete response. In contrast, phenotypic diversity was different between pre- and posttreatment samples. We also observed significant changes in the spatial distribution of cells with distinct genetic and phenotypic features. We used these experimental data to develop a stochastic computational model to infer tumor growth patterns and evolutionary dynamics. Our results highlight the importance of integrated analysis of genotypes and phenotypes of single cells in intact tissues to predict tumor evolution. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The evolutionary psychology of women's aggression

PubMed Central

Campbell, Anne

2013-01-01

Evolutionary researchers have identified age, operational sex ratio and high variance in male resources as factors that intensify female competition. These are discussed in relation to escalated intrasexual competition for men and their resources between young women in deprived neighbourhoods. For these women, fighting is not seen as antithetical to cultural conceptions of femininity, and female weakness is disparaged. Nonetheless, even where competitive pressures are high, young women's aggression is less injurious and frequent than young men's. From an evolutionary perspective, I argue that the intensity of female aggression is constrained by the greater centrality of mothers, rather than fathers, to offspring survival. This selection pressure is realized psychologically through a lower threshold for fear among women. Neuropsychological evidence is not yet conclusive but suggests that women show heightened amygdala reactivity to threatening stimuli, may be better able to exert prefrontal cortical control over emotional behaviour and may consciously register fear more strongly via anterior cingulate activity. The impact of testosterone and oxytocin on the neural circuitry of emotion is also considered. PMID:24167308

Diminished perisomatic GABAergic terminals on cortical neurons adjacent to amyloid plaques.

PubMed

Garcia-Marin, Virginia; Blazquez-Llorca, Lidia; Rodriguez, José-Rodrigo; Boluda, Susana; Muntane, Gerard; Ferrer, Isidro; Defelipe, Javier

2009-01-01

One of the main pathological hallmarks of Alzheimer's disease (AD) is the accumulation of plaques in the cerebral cortex, which may appear either in the neuropil or in direct association with neuronal somata. Since different axonal systems innervate the dendritic (mostly glutamatergic) and perisomatic (mostly GABAergic) regions of neurons, the accumulation of plaques in the neuropil or associated with the soma might produce different alterations to synaptic circuits. We have used a variety of conventional light, confocal and electron microscopy techniques to study their relationship with neuronal somata in the cerebral cortex from AD patients and APP/PS1 transgenic mice. The main finding was that the membrane surfaces of neurons (mainly pyramidal cells) in contact with plaques lack GABAergic perisomatic synapses. Since these perisomatic synapses are thought to exert a strong influence on the output of pyramidal cells, their loss may lead to the hyperactivity of the neurons in contact with plaques. These results suggest that plaques modify circuits in a more selective manner than previously thought.

Inference of tumor evolution during chemotherapy by computational modeling and in situ analysis of cellular diversity for genetic and phenotypic features

PubMed Central

Almendro, Vanessa; Cheng, Yu-Kang; Randles, Amanda; Itzkovitz, Shalev; Marusyk, Andriy; Ametller, Elisabet; Gonzalez-Farre, Xavier; Muñoz, Montse; Russnes, Hege G.; Helland, Åslaug; Rye, Inga H.; Borresen-Dale, Anne-Lise; Maruyama, Reo; van Oudenaarden, Alexander; Dowsett, Mitchell; Jones, Robin L.; Reis-Filho, Jorge; Gascon, Pere; Gönen, Mithat; Michor, Franziska; Polyak, Kornelia

2014-01-01

SUMMARY Cancer therapy exerts a strong selection pressure that shapes tumor evolution, yet our knowledge of how tumors change during treatment is limited. Here we report the analysis of cellular heterogeneity for genetic and phenotypic features and their spatial distribution in breast tumors pre- and post-neoadjuvant chemotherapy. We found that intratumor genetic diversity was tumor subtype-specific and it did not change during treatment in tumors with partial or no response. However, lower pre-treatment genetic diversity was significantly associated with complete pathologic response. In contrast, phenotypic diversity was different between pre- and post-treatment samples. We also observed significant changes in the spatial distribution of cells with distinct genetic and phenotypic features. We used these experimental data to develop a stochastic computational model to infer tumor growth patterns and evolutionary dynamics. Our results highlight the importance of integrated analysis of genotypes and phenotypes of single cells in intact tissues to predict tumor evolution. PMID:24462293

5-HT receptor subtypes as key targets in mediating pigment dispersion within melanophores of teleost, Oreochromis mossambicus.

PubMed

Salim, Saima; Ali, Ayesha S; Ali, Sharique A

2013-02-01

The presence of distinct class of 5-HT receptors in the melanophores of tilapia (Oreochromis mossambicus) is reported. The cellular responses to 5-HT (5-hydroxytryptamine), 5-HT(1), and 5-HT(2), agonists on isolated scale melanophores were observed with regard to pigment translocation within the cells. It was found that 5-HT exerted rapid and strong concentration dependent pigment granule dispersion within the melanophores. The threshold pharmacological dose of 5-HT that could elicit a measurable response was as low as 4.7×10(-12) M/L. Selective 5-HT(1) and 5-HT(2) agonists, sumatriptan and myristicin were investigated and resulted in dose-dependent pigment dispersion. The dispersing effects were effectively antagonized by receptor specific antagonists. It is suggested that 5-HT-induced physiological effects are mediated via distinct classes of receptors that possibly participate in modulation of pigmentary responses of the fish. Copyright © 2012 Elsevier Inc. All rights reserved.

Selective deficit in personal moral judgment following damage to ventromedial prefrontal cortex

PubMed Central

Ciaramelli, Elisa; Muccioli, Michela; Làdavas, Elisabetta

2007-01-01

Recent fMRI evidence has detected increased medial prefrontal activation during contemplation of personal moral dilemmas compared to impersonal ones, which suggests that this cortical region plays a role in personal moral judgment. However, functional imaging results cannot definitively establish that a brain area is necessary for a particular cognitive process. This requires evidence from lesion techniques, such as studies of human patients with focal brain damage. Here, we tested 7 patients with lesions in the ventromedial prefrontal cortex and 12 healthy individuals in personal moral dilemmas, impersonal moral dilemmas and non-moral dilemmas. Compared to normal controls, patients were more willing to judge personal moral violations as acceptable behaviors in personal moral dilemmas, and they did so more quickly. In contrast, their performance in impersonal and non-moral dilemmas was comparable to that of controls. These results indicate that the ventromedial prefrontal cortex is necessary to oppose personal moral violations, possibly by mediating anticipatory, self-focused, emotional reactions that may exert strong influence on moral choice and behavior. PMID:18985127

In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system

PubMed Central

Lee, On On; Wang, Yong; Tian, Renmao; Zhang, Weipeng; Shek, Chun Shum; Bougouffa, Salim; Al-Suwailem, Abdulaziz; Batang, Zenon B.; Xu, Wei; Wang, Guang Chao; Zhang, Xixiang; Lafi, Feras F.; Bajic, Vladmir B.; Qian, Pei-Yuan

2014-01-01

Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira. These results suggest that the redox environments at the deployment sites might have exerted a strong selection on microbes in the biofilms at two sites whereas the types of substrates had limited effects on the biofilm development. PMID:24399144

Inference of tumor evolution during chemotherapy by computational modeling and in situ analysis of genetic and phenotypic cellular diversity

DOE PAGES

Almendro, Vanessa; Cheng, Yu -Kang; Randles, Amanda; ...

2014-02-01

Cancer therapy exerts a strong selection pressure that shapes tumor evolution, yet our knowledge of how tumors change during treatment is limited. Here, we report the analysis of cellular heterogeneity for genetic and phenotypic features and their spatial distribution in breast tumors pre- and post-neoadjuvant chemotherapy. We found that intratumor genetic diversity was tumor-subtype specific, and it did not change during treatment in tumors with partial or no response. However, lower pretreatment genetic diversity was significantly associated with pathologic complete response. In contrast, phenotypic diversity was different between pre- and post-treatment samples. We also observed significant changes in the spatialmore » distribution of cells with distinct genetic and phenotypic features. We used these experimental data to develop a stochastic computational model to infer tumor growth patterns and evolutionary dynamics. Our results highlight the importance of integrated analysis of genotypes and phenotypes of single cells in intact tissues to predict tumor evolution.« less

Role of the flavonoid-rich fraction in the antioxidant and cytotoxic activities of Bauhinia forficata Link. (Fabaceae) leaves extract.

PubMed

Miceli, Natalizia; Buongiorno, Luigina Pasqualina; Celi, Maria Grazia; Cacciola, Francesco; Dugo, Paola; Donato, Paola; Mondello, Luigi; Bonaccorsi, Irene; Taviano, Maria Fernanda

2016-06-01

Bauhinia forficata Link. is utilised as an antidiabetic in Brazilian folk-medicine; furthermore, its antioxidant properties suggest a potential usefulness in the prevention of diabetes complications associated with oxidative stress. The contribution of a flavonoid-rich fraction (FRF), HPLC-PDA-ESI-MS characterised, to the antioxidant and cytotoxic properties of B. forficata hydro-alcoholic leaves extract was evaluated for the first time. Both extract and FRF showed radical-scavenging activity and reducing power with a strong relationship with the flavonoid content found; hence, flavonoids are mainly responsible for the primary antioxidant activity of B. forficata extract. The extract significantly decreased FO-1 cell viability at the higher concentrations. FRF did not exert any effect; thus, flavonoids do not appear to be responsible for the cytotoxicity of the extract. The extract resulted virtually non-toxic against both Artemia salina and normal human lymphocytes, demonstrating potential selectivity in inhibiting cancer cell growth. Finally, no antimicrobial activity was observed against the bacteria and yeasts tested.

Selective enhancement of orientation tuning before saccades.

PubMed

Ohl, Sven; Kuper, Clara; Rolfs, Martin

2017-11-01

Saccadic eye movements cause a rapid sweep of the visual image across the retina and bring the saccade's target into high-acuity foveal vision. Even before saccade onset, visual processing is selectively prioritized at the saccade target. To determine how this presaccadic attention shift exerts its influence on visual selection, we compare the dynamics of perceptual tuning curves before movement onset at the saccade target and in the opposite hemifield. Participants monitored a 30-Hz sequence of randomly oriented gratings for a target orientation. Combining a reverse correlation technique previously used to study orientation tuning in neurons and general additive mixed modeling, we found that perceptual reports were tuned to the target orientation. The gain of orientation tuning increased markedly within the last 100 ms before saccade onset. In addition, we observed finer orientation tuning right before saccade onset. This increase in gain and tuning occurred at the saccade target location and was not observed at the incongruent location in the opposite hemifield. The present findings suggest, therefore, that presaccadic attention exerts its influence on vision in a spatially and feature-selective manner, enhancing performance and sharpening feature tuning at the future gaze location before the eyes start moving.

Flower power: its association with bee power and floral functional morphology in papilionate legumes

PubMed Central

Córdoba, Silvina A.; Cocucci, Andrea A.

2011-01-01

Background and Aims A test was made of the hypothesis that papilionate legume flowers filter pollinators according to their ability to exert strength to open flowers to access rewards. In addition, interactions with pollen vectors were expected to explain the structural complexity of the architecture of these flowers since operative flower strength may be determined by a combination of morphological traits which form part of an intrafloral functional module. Methods Six papilionate species were studied: Collaea argentina, Desmodium uncinatum, Galactia latisiliqua, Lathyrus odoratus, Spartium junceum and Tipuana tipu. Measurements were made of the strength needed to open keels and the strength that pollinators were capable of exerting. Morphological traits of all petals were also measured to determine which of them could be either mutually correlated or correlated with operative strength and moment of strength and participated in a functional module. Key Results It was observed that pollinators were capable in all cases of exerting forces higher and often several times higher than that needed to access floral rewards, and no association could be detected between floral operative strength and strength exerted by the corresponding pollinators. On the other hand, strong and significant correlations were found among morphometric traits and, of these, with operative strength and moment. This was particularly evident among traits of the keel and the wings, presumably involved in the functioning of the floral moveable mechanism. Conclusions Though visitors are often many times stronger than the operative strength of the flowers they pollinate, exceptionally weak bees such as Apis mellifera cannot open the strongest flowers. On the other hand, strong correlations among certain petal morphometric traits (particularly between the keel and wings) give support to the idea that an intrafloral module is associated with the functioning of the mechanism of these legume flowers. In addition, the highly significant correlations found across petals support the view of functional phenotypic integration transcending the ontogenetic organization of flower structure. PMID:21821623

Mechanical properties of different airway stents.

PubMed

Ratnovsky, Anat; Regev, Noa; Wald, Shaily; Kramer, Mordechai; Naftali, Sara

2015-04-01

Airway stents improve pulmonary function and quality of life in patients suffering from airway obstruction. The aim of this study was to compare main types of stents (silicone, balloon-dilated metal, self-expanding metal, and covered self-expanding metal) in terms of their mechanical properties and the radial forces they exert on the trachea. Mechanical measurements were carried out using a force gauge and specially designed adaptors fabricated in our lab. Numerical simulations were performed for eight different stent geometries, inserted into trachea models. The results show a clear correlation between stent diameter (oversizing) and the levels of stress it exerts on the trachea. Compared with uncovered metal stents, metal stents that are covered with less stiff material exert significantly less stress on the trachea while still maintaining strong contact with it. The use of such stents may reduce formation of mucosa necrosis and fistulas while still preventing stent migration. Silicone stents produce the lowest levels of stress, which may be due to weak contact between the stent and the trachea and can explain their propensity for migration. Unexpectedly, stents made of the same materials exerted different stresses due to differences in their structure. Stenosis significantly increases stress levels in all stents. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Runoff delay exerts a strong control on the field-scale removal of manure-borne fecal bacteria with runoff

USDA-ARS?s Scientific Manuscript database

The microbial safety of surface waters is an ongoing issue which is threatened by the transport of manure-borne bacteria to water sources used for irrigation or recreation. Predictive modeling has become an effective tool to forecast the microbial quality of water duringprecipitation events, however...

Transcriptional and Hormonal Regulation of Gravitropism of Woody Stems in Populus

Treesearch

Suzanne Gerttula; Matthew S. Zinkgraf; Gloria K. Muday; Daniel R. Lewis; Farid M. Ibatullin; Harry Brumer; Foster Hart; Shawn D. Mansfield; Vladimir Filkov; Andrew Groover

2015-01-01

Angiosperm trees reorient their woody stems by asymmetrically producing a specialized xylem tissue, tension wood, which exerts a strong contractile force resulting in negative gravitropism of the stem. Here, we show, in Populus trees, that initial gravity perception and response occurs in specialized cells through sedimentation of starch-filled...

Reconciling Intuitive Physics and Newtonian Mechanics for Colliding Objects

ERIC Educational Resources Information Center

Sanborn, Adam N.; Mansinghka, Vikash K.; Griffiths, Thomas L.

2013-01-01

People have strong intuitions about the influence objects exert upon one another when they collide. Because people's judgments appear to deviate from Newtonian mechanics, psychologists have suggested that people depend on a variety of task-specific heuristics. This leaves open the question of how these heuristics could be chosen, and how to…

Optimizing the experimental design using the house mouse (Mus musculus L.) as a model for determining grain feeding preferences

USDA-ARS?s Scientific Manuscript database

Technical Abstract: BACKGROUND: There is little research evaluating flavor preferences among wheat varieties. We previously demonstrated that mice exert very strong preferences when given binary mixtures of wheat varieties. We plan to utilize mice to identify varieties and genes associated with pref...

Net carbon uptake has increased through warming-induced changes in temperate forest phenology

Treesearch

Trevor F. Keenan; Josh Gray; Mark A. Friedl; Michael Toomey; Gil Bohrer; David Y. Hollinger; J. William Munger; John O’Keefe; Hans Peter Schmid; Ian Sue Wing; Bai Yang; Andrew D. Richardson

2014-01-01

The timing of phenological events exerts a strong control over ecosystem function and leads to multiple feedbacks to the climate system1. Phenology is inherently sensitive to temperature (although the exact sensitivity is disputed2) and recent warming is reported to have led to earlier spring, later autumn3,4...

Project-Based Learning and Rubrics in the Teaching of Power Supplies and Photovoltaic Electricity

ERIC Educational Resources Information Center

Martinez, F.; Herrero, L. C.; de Pablo, S.

2011-01-01

Project-based learning (PBL) and cooperative learning are, in various aspects, very superior education methodologies compared to other traditional ones. They are highly appropriate methodologies for elective courses, as they exert a strong attraction on the students, quite apart from their educational advantages. This paper describes how PBL and…

Hydrologic processes influencing meadow ecosystems [chapter 4

Treesearch

Mark L. Lord; David G. Jewett; Jerry R. Miller; Dru Germanoski; Jeanne C. Chambers

2011-01-01

The hydrologic regime exerts primary control on riparian meadow complexes and is strongly influenced by past and present geomorphic processes; biotic processes; and, in some cases, anthropogenic activities. Thus, it is essential to understand not only the hydrologic processes that operate within meadow complexes but also the interactions of meadow hydrology with other...

Parental Values and Practices Relevant to Young Children's Social Development in Taiwan and the United States.

ERIC Educational Resources Information Center

Jose, Paul E.; Huntsinger, Carol S.; Huntsinger, Phillip R.; Liaw, Fong-Ruey

2000-01-01

Compared self-reported parental values and child-rearing practices and teacher-reported and observed children's social skills among families of young children who were first-generation Chinese Americans, European Americans, or Taiwanese Chinese. All Chinese parents more strongly endorsed traditional Chinese values and exerted more parental control…

RPE and Velocity Relationships for the Back Squat, Bench Press, and Deadlift in Powerlifters.

PubMed

Helms, Eric R; Storey, Adam; Cross, Matt R; Brown, Scott R; Lenetsky, Seth; Ramsay, Hamish; Dillen, Carolina; Zourdos, Michael C

2017-02-01

Helms, ER, Storey, A, Cross, MR, Browm, SR, Lenetsky, S, Ramsay, H, Dillen, C, and Zourdos, MC. RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. J Strength Cond Res 31(2): 292-297, 2017-The purpose of this study was to compare average concentric velocity (ACV) and rating of perceived exertion (RPE) based on repetitions in reserve on the squat, bench press, and deadlift. Fifteen powerlifters (3 women and 12 men, mean age 28.4 ± 8.5 years) worked up to a one repetition maximum (1RM) on each lift. Rating of perceived exertion was recorded on all sets, and the ACV was recorded for all sets performed at 80% of estimated 1RM and higher, up to 1RM. Rating of perceived exertion at 1RM on squat, bench press, and deadlift was 9.6 ± 0.5, 9.7 ± 0.4, and 9.6 ± 0.5, respectively and was not significantly different (p > 0.05). The ACV at 1RM on squat, bench press and deadlift was 0.23 ± 0.05, 0.10 ± 0.04, and 0.14 ± 0.05 m·second, respectively. Squat was faster than both bench press and deadlift (p > 0.001), and deadlift was faster than bench press (p = 0.05). Very strong relationships (r = 0.88-0.91) between percentage 1RM and RPE were observed on each lift. The ACV showed strong (r = -0.79 to -0.87) and very strong (r = -0.90 to 92) inverse relationships with RPE and percentage 1RM on each lift, respectively. We conclude that RPE may be a useful tool for prescribing intensity for squat, bench press, and deadlift in powerlifters, in addition to traditional methods such as percentage of 1RM. Despite high correlations between percentage 1RM and ACV, a "velocity load profile" should be developed to prescribe intensity on an individual basis with appropriate accuracy.

Phenotypic Divergence among West European Populations of Reed Bunting Emberiza schoeniclus: The Effects of Migratory and Foraging Behaviours

PubMed Central

Neto, Júlio M.; Gordinho, Luís; Belda, Eduardo J.; Marín, Marcial; Monrós, Juan S.; Fearon, Peter; Crates, Ross

2013-01-01

Divergent selection and local adaptation are responsible for many phenotypic differences between populations, potentially leading to speciation through the evolution of reproductive barriers. Here we evaluated the morphometric divergence among west European populations of Reed Bunting in order to determine the extent of local adaptation relative to two important selection pressures often associated with speciation in birds: migration and diet. We show that, as expected by theory, migratory E. s. schoeniclus had longer and more pointed wings and a slightly smaller body mass than the resident subspecies, with the exception of E. s. lusitanica, which despite having rounder wings was the smallest of all subspecies. Tail length, however, did not vary according to the expectation (shorter tails in migrants) probably because it is strongly correlated with wing length and might take longer to evolve. E. s. witherbyi, which feed on insects hiding inside reed stems during the winter, had a very thick, stubby bill. In contrast, northern populations, which feed on seeds, had thinner bills. Despite being much smaller, the southern E. s. lusitanica had a significantly thicker, longer bill than migratory E. s. schoeniclus, whereas birds from the UK population had significantly shorter, thinner bills. Geometric morphometric analyses revealed that the southern subspecies have a more convex culmen than E. s. schoeniclus, and E. s. lusitanica differs from the nominate subspecies in bill shape to a greater extent than in linear bill measurements, especially in males. Birds with a more convex culmen are thought to exert a greater strength at the bill tip, which is in agreement with their feeding technique. Overall, the three subspecies occurring in Western Europe differ in a variety of traits following the patterns predicted from their migratory and foraging behaviours, strongly suggesting that these birds have became locally adapted through natural selection. PMID:23667594

Physical root-soil interactions

NASA Astrophysics Data System (ADS)

Kolb, Evelyne; Legué, Valérie; Bogeat-Triboulot, Marie-Béatrice

2017-12-01

Plant root system development is highly modulated by the physical properties of the soil and especially by its mechanical resistance to penetration. The interplay between the mechanical stresses exerted by the soil and root growth is of particular interest for many communities, in agronomy and soil science as well as in biomechanics and plant morphogenesis. In contrast to aerial organs, roots apices must exert a growth pressure to penetrate strong soils and reorient their growth trajectory to cope with obstacles like stones or hardpans or to follow the tortuous paths of the soil porosity. In this review, we present the main macroscopic investigations of soil-root physical interactions in the field and combine them with simple mechanistic modeling derived from model experiments at the scale of the individual root apex.

Physical root-soil interactions.

PubMed

Kolb, Evelyne; Legué, Valérie; Bogeat-Triboulot, Marie-Béatrice

2017-11-16

Plant root system development is highly modulated by the physical properties of the soil and especially by its mechanical resistance to penetration. The interplay between the mechanical stresses exerted by the soil and root growth is of particular interest for many communities, in agronomy and soil science as well as in biomechanics and plant morphogenesis. In contrast to aerial organs, roots apices must exert a growth pressure to penetrate strong soils and reorient their growth trajectory to cope with obstacles like stones or hardpans or to follow the tortuous paths of the soil porosity. In this review, we present the main macroscopic investigations of soil-root physical interactions in the field and combine them with simple mechanistic modeling derived from model experiments at the scale of the individual root apex.

Ergonomics and patient handling.

PubMed

McCoskey, Kelsey L

2007-11-01

This study aimed to describe patient-handling demands in inpatient units during a 24-hour period at a military health care facility. A 1-day total population survey described the diverse nature and impact of patient-handling tasks relative to a variety of nursing care units, patient characteristics, and transfer equipment. Productivity baselines were established based on patient dependency, physical exertion, type of transfer, and time spent performing the transfer. Descriptions of the physiological effect of transfers on staff based on patient, transfer, and staff characteristics were developed. Nursing staff response to surveys demonstrated how patient-handling demands are impacted by the staff's physical exertion and level of patient dependency. The findings of this study describe the types of transfers occurring in these inpatient units and the physical exertion and time requirements for these transfers. This description may guide selection of the most appropriate and cost-effective patient-handling equipment required for specific units and patients.

Regulation of TRP channels by steroids: Implications in physiology and diseases.

PubMed

Kumar, Ashutosh; Kumari, Shikha; Majhi, Rakesh Kumar; Swain, Nirlipta; Yadav, Manoj; Goswami, Chandan

2015-09-01

While effects of different steroids on the gene expression and regulation are well established, it is proven that steroids can also exert rapid non-genomic actions in several tissues and cells. In most cases, these non-genomic rapid effects of steroids are actually due to intracellular mobilization of Ca(2+)- and other ions suggesting that Ca(2+) channels are involved in such effects. Transient Receptor Potential (TRP) ion channels or TRPs are the largest group of non-selective and polymodal ion channels which cause Ca(2+)-influx in response to different physical and chemical stimuli. While non-genomic actions of different steroids on different ion channels have been established to some extent, involvement of TRPs in such functions is largely unexplored. In this review, we critically analyze the literature and summarize how different steroids as well as their metabolic precursors and derivatives can exert non-genomic effects by acting on different TRPs qualitatively and/or quantitatively. Such effects have physiological repercussion on systems such as in sperm cells, immune cells, bone cells, neuronal cells and many others. Different TRPs are also endogenously expressed in diverse steroid-producing tissues and thus may have importance in steroid synthesis as well, a process which is tightly controlled by the intracellular Ca(2+) concentrations. Tissue and cell-specific expression of TRP channels are also regulated by different steroids. Understanding of the crosstalk between TRP channels and different steroids may have strong significance in physiological, endocrinological and pharmacological context and in future these compounds can also be used as potential biomedicine. Copyright © 2014 Elsevier Inc. All rights reserved.

Association between Polycystic Ovary Syndrome, Oral Microbiota and Systemic Antibody Responses

PubMed Central

Akcalı, Aliye; Bostanci, Nagihan; Özçaka, Özgün; Öztürk-Ceyhan, Banu; Gümüş, Pınar; Buduneli, Nurcan; Belibasakis, Georgios N.

2014-01-01

Polycystic ovary syndrome (PCOS) is a hormonal disorder of women that not only is the leading cause of infertility but also shows a reciprocal link with oral health. This study aimed to investigate the hypothesis that the levels of putative periodontal pathogens in saliva and their antibody response in serum are elevated in PCOS, compared to systemic health. A total of 125 women were included in four groups; 45 women with PCOS and healthy periodontium, 35 women with PCOS and gingivitis, 25 systemically and periodontally healthy women, 20 systemically healthy women with gingivitis. Salivary levels of seven putative periodontal pathogens were analyzed by quantitative real-time polymerase chain reaction and serum antibody levels were analyzed by ELISA. In women with PCOS, salivary Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus oralis and Tannerella forsythia levels were higher than matched systemically healthy women, particularly in the case of gingivitis. Aggregatibacter actinomycetemcomitans and Treponema denticola levels were similar among study groups. The presence of PCOS also enhanced P. gingivalis, Prevotella intermedia and S. oralis serum antibody levels, when gingivitis was also present. Gingival inflammation correlated positively with levels of the studied taxa in saliva, particularly in PCOS. The presence of P. gingivalis and F. nucleatum in saliva also exhibited a strong positive correlation with the corresponding serum antibody levels. In conclusion, as an underlying systemic endocrine condition, PCOS may quantitatively affect the composition of oral microbiota and the raised systemic response to selective members of this microbial community, exerting a confounding role in resultant gingival inflammation and periodontal health. The most consistent effect appeared to be exerted on P. gingivalis. PMID:25232962

SSRIs and ejaculation: a double-blind, randomized, fixed-dose study with paroxetine and citalopram.

PubMed

Waldinger, M D; Zwinderman, A H; Olivier, B

2001-12-01

Selective serotonin reuptake inhibitors (SSRIs) are known to induce delayed orgasm and ejaculation. However, different SSRIs may differentially delay ejaculation. A double-blind, fixed-dose study in healthy men with lifelong rapid ejaculation was performed to evaluate potential differences between clinically relevant doses of two selective serotonin reuptake inhibitors, paroxetine and citalopram, in their effects on ejaculation. Thirty men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to receive paroxetine (20 mg/day) and citalopram (20 mg/day) for 5 weeks, after taking half the dosage in the first week. During the 1-month baseline and 6-week treatment period, IELTs were measured at home by using a stopwatch procedure. The trial was completed by 23 men. Analysis of variance revealed a between-group difference in the evolution of IELT delay over time (p = 0.0004); the IELT after paroxetine and citalopram gradually increased from 18 and 21 seconds to approximately 170 and 44 seconds, respectively. Paroxetine 20 mg/day exerted a strong delay (8.9-fold increase), whereas citalopram 20 mg/day mildly delayed ejaculation (1.8-fold increase). These results indicate that paroxetine leads to a significant delay in orgasm and ejaculation, whereas citalopram seems to have less of an effect on it.

Adaptation to enemy shifts: rapid resistance evolution to local Vibrio spp. in invasive Pacific oysters

PubMed Central

Wendling, Carolin C.; Wegner, K. Mathias

2015-01-01

One hypothesis for the success of invasive species is reduced pathogen burden, resulting from a release from infections or high immunological fitness of invaders. Despite strong selection exerted on the host, the evolutionary response of invaders to newly acquired pathogens has rarely been considered. The two independent and genetically distinct invasions of the Pacific oyster Crassostrea gigas into the North Sea represent an ideal model system to study fast evolutionary responses of invasive populations. By exposing both invasion sources to ubiquitous and phylogenetically diverse pathogens (Vibrio spp.), we demonstrate that within a few generations hosts adapted to newly encountered pathogen communities. However, local adaptation only became apparent in selective environments, i.e. at elevated temperatures reflecting patterns of disease outbreaks in natural populations. Resistance against sympatric and allopatric Vibrio spp. strains was dominantly inherited in crosses between both invasion sources, resulting in an overall higher resistance of admixed individuals than pure lines. Therefore, we suggest that a simple genetic resistance mechanism of the host is matched to a common virulence mechanism shared by local Vibrio strains. This combination might have facilitated a fast evolutionary response that can explain another dimension of why invasive species can be so successful in newly invaded ranges. PMID:25716784

Effect of fibrillation conditions on the anti-amyloidogenic properties of polyphenols and their involved mechanisms.

PubMed

Mahdavimehr, Mohsen; Katebi, Bentolhoda; Meratan, Ali Akbar

2018-06-24

In the present study, we have investigated the effects of protein concentration and stirring on the in vitro assembly of Hen Egg White Lysozyme (HEWL), particularly with regard to the aggregate morphology and anti-amyloidogenic properties of two naturally occurring polyphenols, taxifolin and silibinin. The results obtained clearly demonstrated that applying stirring and concentration enhancement alter the amount as well as morphology of amyloid fibrils formed. Additionally, latter aggregates exhibited higher affinity for amyloid-specific dyes. The second part of the present investigation was devoted to studies involving anti-amyloidogenic properties of selected polyphenols. Importantly, we found that the potency of polyphenols to inhibit HEWL amyloid fibrillation and related toxicity is strongly dependent on the amyloidogenic conditions in which amyloid fibrils are produced. Based on obtained data, under condition where the rate of protein assembly is high (higher protein concentration and stirring), the capacity of polyphenols to inhibit HEWL fibrillogenesis and related cytotoxicity may dramatically decrease. Similar results were obtained when we used taxifolin to inhibit bovine insulin amyloid fibrillation. Additionally, amyloidogenic conditions may also affect the mechanism by which these molecules inhibit HEWL fibrillation. The possible mechanism by which selected polyphenols exert their inhibitory effects, under various experimental conditions, is also discussed. Copyright © 2018. Published by Elsevier B.V.

From cumulative cultural transmission to evidence-based medicine: evolution of medicinal plant knowledge in Southern Italy

PubMed Central

Leonti, Marco; Staub, Peter O.; Cabras, Stefano; Castellanos, Maria Eugenia; Casu, Laura

2015-01-01

In Mediterranean cultures written records of medicinal plant use have a long tradition. This written record contributed to building a consensus about what was perceived to be an efficacious pharmacopeia. Passed down through millennia, these scripts have transmitted knowledge about plant uses, with high fidelity, to scholars and laypersons alike. Herbal medicine's importance and the long-standing written record call for a better understanding of the mechanisms influencing the transmission of contemporary medicinal plant knowledge. Here we contextualize herbal medicine within evolutionary medicine and cultural evolution. Cumulative knowledge transmission is approached by estimating the causal effect of two seminal scripts about materia medica written by Dioscorides and Galen, two classical Greco-Roman physicians, on today's medicinal plant use in the Southern Italian regions of Campania, Sardinia, and Sicily. Plant-use combinations are treated as transmissible cultural traits (or “memes”), which in analogy to the biological evolution of genetic traits, are subjected to mutation and selection. Our results suggest that until today ancient scripts have exerted a strong influence on the use of herbal medicine. We conclude that the repeated empirical testing and scientific study of health care claims is guiding and shaping the selection of efficacious treatments and evidence-based herbal medicine. PMID:26483686

From cumulative cultural transmission to evidence-based medicine: evolution of medicinal plant knowledge in Southern Italy.

PubMed

Leonti, Marco; Staub, Peter O; Cabras, Stefano; Castellanos, Maria Eugenia; Casu, Laura

2015-01-01

In Mediterranean cultures written records of medicinal plant use have a long tradition. This written record contributed to building a consensus about what was perceived to be an efficacious pharmacopeia. Passed down through millennia, these scripts have transmitted knowledge about plant uses, with high fidelity, to scholars and laypersons alike. Herbal medicine's importance and the long-standing written record call for a better understanding of the mechanisms influencing the transmission of contemporary medicinal plant knowledge. Here we contextualize herbal medicine within evolutionary medicine and cultural evolution. Cumulative knowledge transmission is approached by estimating the causal effect of two seminal scripts about materia medica written by Dioscorides and Galen, two classical Greco-Roman physicians, on today's medicinal plant use in the Southern Italian regions of Campania, Sardinia, and Sicily. Plant-use combinations are treated as transmissible cultural traits (or "memes"), which in analogy to the biological evolution of genetic traits, are subjected to mutation and selection. Our results suggest that until today ancient scripts have exerted a strong influence on the use of herbal medicine. We conclude that the repeated empirical testing and scientific study of health care claims is guiding and shaping the selection of efficacious treatments and evidence-based herbal medicine.

Evolution of extreme body size disparity in monitor lizards (Varanus).

PubMed

Collar, David C; Schulte, James A; Losos, Jonathan B

2011-09-01

Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards. © 2011 The Author(s).

Evolution of dominance in sporophytic self-incompatibility systems: I. Genetic load and coevolution of levels of dominance in pollen and pistil.

PubMed

Llaurens, Violaine; Billiard, Sylvain; Castric, Vincent; Vekemans, Xavier

2009-09-01

Recent theoretical advances have suggested that various forms of balancing selection may promote the evolution of dominance through an increase of the proportion of heterozygote genotypes. We test whether dominance can evolve in the sporophytic self-incompatibility (SSI) system in plants. SSI prevents mating between individuals expressing identical SI phenotypes by recognition of pollen by pistils, which avoids selfing and inbreeding depression. SI phenotypes depend on a complex network of dominance relationships between alleles at the self-incompatibility locus (S-locus). Empirical studies suggest that these relationships are not random, but the exact evolutionary processes shaping these relationships remain unclear. We investigate the expected patterns of dominance under the hypothesis that dominance is a direct target of natural selection. We follow the fate of a mutant allele at the S-locus whose dominance relationships are changed but whose specificity remains unaltered. We show that strict codominance is not evolutionarily stable in SSI, and that inbreeding depression due to deleterious mutations linked or unlinked to the S-locus exerts strong constraints on changes in relative levels of dominance in pollen and pistil. Our results provide a general adaptive explanation for most patterns of dominance relationships empirically observed in natural plant populations.

Physical Test Validation for Job Selection. Chapter 5

DTIC Science & Technology

2000-09-21

Borgs perceived exertion andlpain scaling method. Champaign: Human Kinetics . 17. Brooks, G., & Fahey, T (1984). Exercise physiology: Human bioenergetics...Eds.), Measurement concepts in physical education and exercise science. Champaign: Human Kinetics . 44. Jackson, A. S., Blair, S. N., Mahar, M. T...Chapter 5: Physical Test Evaluation for Job Selection 94. Wilmore, J. H., & Costill, D. L. (1994). Physiology of sport and exercise. Champaign, IL: Human

Genetic variation of lodgepole pine physical and chemical defenses associated with each step in host selection behavior sequence by mountain pine beetle

Treesearch

Kimberly F. Wallin; Daniel S. Ott; Alvin D. Yanchuk

2012-01-01

Abiotic and biotic stressors exert selective pressures on plants, and over evolutionary time lead to the development of specialized adaptations and specific responses to stresses (Safranyik and Carroll 2006, Wallin and Raffa 2002). In this way, the environment in which plants evolve shapes their life cycles, range, growth, reproduction, and defenses. Insects and...

Quantification of upper limb kinetic asymmetries in front crawl swimming.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Fernandes, Ricardo J; Marques, Mário C

2015-04-01

This study aimed at quantifying upper limb kinetic asymmetries in maximal front crawl swimming and to examine if these asymmetries would affect the contribution of force exertion to swimming performance. Eighteen high level male swimmers with unilateral breathing patterns and sprint or middle distance specialists, volunteered as participants. A load-cell was used to quantify the forces exerted in water by completing a 30s maximal front crawl tethered swimming test and a maximal 50 m free swimming was considered as a performance criterion. Individual force-time curves were obtained to calculate the mean and maximum forces per cycle, for each upper limb. Following, symmetry index was estimated and breathing laterality identified by questionnaire. Lastly, the pattern of asymmetries along the test was estimated for each upper limb using linear regression of peak forces per cycle. Asymmetrical force exertion was observed in the majority of the swimmers (66.7%), with a total correspondence of breathing laterality opposite to the side of the force asymmetry. Forces exerted by the dominant upper limb presented a higher decrease than from the non-dominant. Very strong associations were found between exerted forces and swimming performance, when controlling the isolated effect of symmetry index. Results point that force asymmetries occur in the majority of the swimmers, and that these asymmetries are most evident in the first cycles of a maximum bout. Symmetry index stood up as an influencing factor on the contribution of tethered forces over swimming performance. Thus, to some extent, a certain degree of asymmetry is not critical for short swimming performance. Copyright © 2015 Elsevier B.V. All rights reserved.

A prospective study of carpal tunnel syndrome: workplace and individual risk factors.

PubMed

Burt, Susan; Deddens, James A; Crombie, Ken; Jin, Yan; Wurzelbacher, Steve; Ramsey, Jessica

2013-08-01

To quantify the risk for carpal tunnel syndrome (CTS) from workplace physical factors, particularly hand activity level and forceful exertion, while taking into account individual factors including age, gender, body mass index (BMI), and pre-existing medical conditions. Three healthcare and manufacturing workplaces were selected for inclusion on the basis of range of exposure to hand activity level and forceful exertion represented by their jobs. Each study participant's job tasks were observed and evaluated onsite and videotaped for further analysis, including frequency and duration of exertion and postural deviation. Individual health assessment entailed electrodiagnostic testing of median and ulnar nerves, physical examination and questionnaires at baseline with annual follow-up for 2 years. The incidence of dominant hand CTS during the study was 5.11 per 100 person-years (29 cases). Adjusted HRs for dominant hand CTS were as follows: working with forceful exertion ≥ 20% but <60% of the time: 2.83 (1.18, 6.79) and ≥ 60% of the time vs <20%: 19.57 (5.96, 64.24), BMI ≥ 30 kg/m(2) (obesity): 3.19 (1.28, 7.98). The American Conference for Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for hand activity level also predicted CTS, HR=1.40 (1.11, 1.78) for each unit increase in the TLV ratio, controlling for obesity and job strain. Workplace and individual risk factors both contribute to the risk for CTS. Time spent in forceful exertion can be a greater risk for CTS than obesity if the job exposure is high. Preventive workplace efforts should target forceful exertions.

Comparative Study of Assisted Ambulation and Perceived Exertion With the Wheeled Knee Walker and Axillary Crutches in Healthy Subjects.

PubMed

Kocher, Benjamin K; Chalupa, Robyn L; Lopez, Donna M; Kirk, Kevin L

2016-11-01

Functional limitations after lower extremity surgery often require the use of an assistive device for ambulation during rehabilitation and recovery. There are no known objective data evaluating the wheeled knee walker as an assistive device for protected ambulation. The purpose of this study was to compare assisted ambulation and perceived exertion with the wheeled knee walker and the axillary crutches in healthy participants. A prospective, randomized crossover study was performed using 24 healthy volunteers. Each participant performed a 6-minute walk test (6MWT) using each assistive device in a crossover manner. Preactivity and postactivity heart rates were recorded. The self-selected walking velocity (SSWV) was calculated and the participant's rating of perceived exertion was recorded using the OMNI Rating of Perceived Exertion (OMNI-RPE). Participant's preference for assistive device was identified. The 6MWT, SSWV, and the Omni-RPE were evaluated using paired t tests and determined to be statistically significant for the wheeled knee walker compared with axillary crutches. Evaluation of the preactivity and postactivity heart rates demonstrated a statistically significant difference for the wheeled knee walker compared with axillary crutches. The wheeled knee walker was preferred by 88% of participants. The wheeled knee walker provided increased assisted ambulation and had a lower rating of perceived exertion than axillary crutches on level surfaces in healthy participants. Level III, comparative study. © The Author(s) 2016.

Runoff delay exerts a strong control on the field-scale removal of manure-borne fecal bacteria with runoff

USDA-ARS?s Scientific Manuscript database

The microbial safety of surface waters is an ongoing issue which is threatened by the transport of manure-borne bacteria to water sources used for irrigation or recreation. Predictive modeling has become an effective tool to forecast the microbial quality of water during precipitation events, howeve...

Ecohydrology of an outbreak: Mountain pine beetle impacts trees in drier landscape positions first

Treesearch

Kendra E. Kaiser; Ryan E. Emanuel

2013-01-01

Vegetation pattern and landscape structure intersect to exert strong control over ecohydrological dynamics at the watershed scale. The hydrologic implications of vegetation disturbance (e.g. fire, disease) depend on the spatial pattern and form of environmental change. Here, we investigate this intersection at Tenderfoot Creek Experimental Forest (TCEF), Montana, with...

From "Ibharu" to "Amajoin": Translocation and Language in a New South African Township

ERIC Educational Resources Information Center

Dyers, Charlyn

2009-01-01

The ongoing migration from the rural areas of South Africa to its cities is exerting strong influences on the language practices of the young, as they learn to cope with new living spaces where languages and cultures converge. Drawing on the theories of transcultural and transidiomatic practices (Jacquemet, 2005; Pennycook, 2007), this article…

Impacts of Hemlock Loss on Nitrogen Retention Vary with Soil Nitrogen Availability in the Southern Appalachian Mountains

Treesearch

Corinne E. Block; Jennifer D. Knoepp; Katherine J. Elliott; Jennifer M. Fraterrigo

2012-01-01

The impacts of exotic insects and pathogens on forest ecosystems are increasingly recognized, yet the factors influencing the magnitude of effects remain poorly understood. Eastern hemlock (Tsuga canadensis) exerts strong control on nitrogen (N) dynamics, and its loss due to infestation by the hemlock woolly adelgid (Adelges tsugae...

Family Sources of Sexual Health Information, Primary Messages, and Sexual Behavior of At-Risk, Urban Adolescents

ERIC Educational Resources Information Center

Rosengard, Cynthia; Tannis, Candace; Dove, David C.; van den Berg, Jacob J.; Lopez, Rosalie; Stein, L. A. R.; Morrow, Kathleen M.

2012-01-01

Background: Sources of sexual health information exert strong influence on adolescents' sexual behavior. Purpose: The current study was undertaken to understand how family serve as sexual information sources, the messages adolescents recall from family, and how family learning experiences affect sexual behavior among at-risk adolescents. Methods:…

Interest Group Conflict Over Medicaid Expansion: The Surprising Impact of Public Advocates

PubMed Central

Callaghan, Timothy

2016-01-01

Objectives. We examined the potential economic, policy, and political influences on the decisions of the 50 US states to expand Medicaid under the Affordable Care Act. Methods. We related a measure of relative state progress toward Medicaid expansion updated to 2015 to each state’s economic circumstances, established policy frameworks in states, partisan control of state government, and lobbyists for businesses, medical professionals, unions, and public interest organizations. Results. The 9201 lobbyists working on health care reform in state capitols exerted a strong and significant impact on Medicaid expansion. Controlling for confounding factors (including partisanship and existing policy frameworks), we found that business and professional lobbyists exerted a negative effect on state Medicaid expansion and, unexpectedly, that public interest advocates exerted a positive effect. Conclusions. There are 3.1 million adults who lack coverage because they live in the 20 states that refused to expand Medicaid. Although political party and lobbyists for private interests present significant barriers in these states, legislative lobbying on behalf of the uninsured appears likely to be effective. PMID:26691109

Inhibition of p38/CREB phosphorylation and COX-2 expression by olive oil polyphenols underlies their anti-proliferative effects

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

Corona, Giulia; Dipartimento di Biologia Sperimentale, Sez. Patologia Sperimentale, Universita degli Studi di Cagliari, 09042 Monserrato; Deiana, Monica

2007-10-26

We investigated the anti-proliferative effects of an olive oil polyphenolic extract on human colon adenocarcinoma cells. Analysis indicated that the extract contained hydroxytyrosol, tyrosol and the various secoiridoid derivatives, including oleuropein. This extract exerted a strong inhibitory effect on cancer cell proliferation, which was linked to the induction of a G2/M phase cell cycle block. Following treatment with the extract (50 {mu}g/ml) the number of cells in the G2/M phase increased to 51.82 {+-} 2.69% relative to control cells (15.1 {+-} 2.5%). This G2/M block was mediated by the ability of olive oil polyphenols (50 {mu}g/ml) to exert rapid inhibitionmore » of p38 (38.7 {+-} 4.7%) and CREB (28.6 {+-} 5.5%) phosphorylation which led to a downstream reduction in COX-2 expression (56.9 {+-} 9.3%). Our data suggest that olive oil polyphenols may exert chemopreventative effects in the large intestine by interacting with signalling pathways responsible for colorectal cancer development.« less

Selective Mitochondrial Targeting Exerts Anxiolytic Effects In Vivo

PubMed Central

Nussbaumer, Markus; Asara, John M; Teplytska, Larysa; Murphy, Michael P; Logan, Angela; Turck, Christoph W; Filiou, Michaela D

2016-01-01

Current treatment strategies for anxiety disorders are predominantly symptom-based. However, a third of anxiety patients remain unresponsive to anxiolytics highlighting the need for more effective, mechanism-based therapeutic approaches. We have previously compared high vs low anxiety mice and identified changes in mitochondrial pathways, including oxidative phosphorylation and oxidative stress. In this work, we show that selective pharmacological targeting of these mitochondrial pathways exerts anxiolytic effects in vivo. We treated high anxiety-related behavior (HAB) mice with MitoQ, an antioxidant that selectively targets mitochondria. MitoQ administration resulted in decreased anxiety-related behavior in HAB mice. This anxiolytic effect was specific for high anxiety as MitoQ treatment did not affect the anxiety phenotype of C57BL/6N and DBA/2J mouse strains. We furthermore investigated the molecular underpinnings of the MitoQ-driven anxiolytic effect and found that MitoQ treatment alters the brain metabolome and that the response to MitoQ treatment is characterized by distinct molecular signatures. These results indicate that a mechanism-driven approach based on selective mitochondrial targeting has the potential to attenuate the high anxiety phenotype in vivo, thus paving the way for translational implementation as long-term MitoQ administration is well-tolerated with no reported side effects in mice and humans. PMID:26567514

Selective Mitochondrial Targeting Exerts Anxiolytic Effects In Vivo.

PubMed

Nussbaumer, Markus; Asara, John M; Teplytska, Larysa; Murphy, Michael P; Logan, Angela; Turck, Christoph W; Filiou, Michaela D

2016-06-01

Current treatment strategies for anxiety disorders are predominantly symptom-based. However, a third of anxiety patients remain unresponsive to anxiolytics highlighting the need for more effective, mechanism-based therapeutic approaches. We have previously compared high vs low anxiety mice and identified changes in mitochondrial pathways, including oxidative phosphorylation and oxidative stress. In this work, we show that selective pharmacological targeting of these mitochondrial pathways exerts anxiolytic effects in vivo. We treated high anxiety-related behavior (HAB) mice with MitoQ, an antioxidant that selectively targets mitochondria. MitoQ administration resulted in decreased anxiety-related behavior in HAB mice. This anxiolytic effect was specific for high anxiety as MitoQ treatment did not affect the anxiety phenotype of C57BL/6N and DBA/2J mouse strains. We furthermore investigated the molecular underpinnings of the MitoQ-driven anxiolytic effect and found that MitoQ treatment alters the brain metabolome and that the response to MitoQ treatment is characterized by distinct molecular signatures. These results indicate that a mechanism-driven approach based on selective mitochondrial targeting has the potential to attenuate the high anxiety phenotype in vivo, thus paving the way for translational implementation as long-term MitoQ administration is well-tolerated with no reported side effects in mice and humans.

Natural selection drives chemical resistance of Datura stramonium

PubMed Central

Miranda-Pérez, Adán; Castillo, Guillermo; Hernández-Cumplido, Johnattan; Valverde, Pedro L.; Borbolla, María; Cruz, Laura L.; Tapia-López, Rosalinda; Fornoni, Juan; Flores-Ortiz, César M.

2016-01-01

Plant resistance to herbivores involves physical and chemical plant traits that prevent or diminish damage by herbivores, and hence may promote coevolutionary arm-races between interacting species. Although Datura stramonium’s concentration of tropane alkaloids is under selection by leaf beetles, it is not known whether chemical defense reduces seed predation by the specialist weevil, Trichobaris soror, and if it is evolving by natural selection. We measured infestation by T. soror as well as the concentration of the plants’ two main tropane alkaloids in 278 D. stramonium plants belonging to 31 populations in central Mexico. We assessed whether the seed predator exerted preferences on the levels of both alkaloids and whether they affect plant fitness. Results show great variation across populations in the concentration of scopolamine and atropine in both leaves and seeds of plants of D. stramonium, as well as in the intensity of infestation and the proportion of infested fruits by T. soror. The concentration of scopolamine in seeds and leaves are negatively associated across populations. We found that scopolamine concentration increases plant fitness. Our major finding was the detection of a positive relationship between the population average concentrations of scopolamine with the selection differentials of scopolamine. Such spatial variation in the direction and intensity of selection on scopolamine may represent a coevolutionary selective mosaic. Our results support the view that variation in the concentration of scopolamine among-populations of D. stramonium in central Mexico is being driven, in part, by selection exerted by T. soror, pointing an adaptive role of tropane alkaloids in this plant species. PMID:27114866

Pavlovian to instrumental transfer of control in a human learning task.

PubMed

Nadler, Natasha; Delgado, Mauricio R; Delamater, Andrew R

2011-10-01

Pavlovian learning tasks have been widely used as tools to understand basic cognitive and emotional processes in humans. The present studies investigated one particular task, Pavlovian-to-instrumental transfer (PIT), with human participants in an effort to examine potential cognitive and emotional effects of Pavlovian cues upon instrumentally trained performance. In two experiments, subjects first learned two separate instrumental response-outcome relationships (i.e., R1-O1 and R2-O2) and then were exposed to various stimulus-outcome relationships (i.e., S1-O1, S2-O2, S3-O3, and S4-) before the effects of the Pavlovian stimuli on instrumental responding were assessed during a non-reinforced test. In Experiment 1, instrumental responding was established using a positive-reinforcement procedure, whereas in Experiment 2, a quasi-avoidance learning task was used. In both cases, the Pavlovian stimuli exerted selective control over instrumental responding, whereby S1 and S2 selectively elevated the instrumental response with which it shared an outcome. In addition, in Experiment 2, S3 exerted a nonselective transfer of control effect, whereby both responses were elevated over baseline levels. These data identify two ways, one specific and one general, in which Pavlovian processes can exert control over instrumental responding in human learning paradigms, suggesting that this method may serve as a useful tool in the study of basic cognitive and emotional processes in human learning.

Pavlovian to Instrumental Transfer of Control in a Human Learning Task

PubMed Central

Nadler, Natasha; Delgado, Mauricio R.; Delamater, Andrew R.

2011-01-01

Pavlovian learning tasks have been widely used as tools to understand basic cognitive and emotional processes in humans. The present studies investigated one particular task, Pavlovian-to-instrumental transfer (PIT), with human participants in an effort to examine potential cognitive and emotional effects of Pavlovian cues upon instrumentally-trained performance. In two experiments subjects first learned two separate instrumental response-outcome relationships (R1-O1, R2-O2) and then were exposed to various stimulus-outcome relationships (S1-O1, S2-O2, S3-O3, S4-) before the effects of the Pavlovian stimuli on instrumental responding were assessed during a nonreinforced test. In Experiment 1 instrumental responding was established using a positive reinforcement procedure whereas in Experiment 2 a quasi-avoidance learning task was used. In both cases the Pavlovian stimuli exerted selective control over instrumental responding, whereby S1 & S2 selectively elevated the instrumental response with which it shared an outcome. In addition, in Experiment 2, S3 exerted a nonselective transfer of control effect, whereby both responses were elevated over baseline levels. These data identify two ways, one specific and one general, in which Pavlovian processes can exert control over instrumental responding in human learning paradigms, and suggest that this method may serve as a useful tool in the study of basic cognitive and emotional processes in human learning. PMID:21534664

Density-dependent effects of ants on selection for bumble bee pollination in Polemonium viscosum.

PubMed

Galen, Candace; Geib, Jennifer C

2007-05-01

Mutualisms are commonly exploited by cheater species that usurp rewards without providing reciprocal benefits. Yet most studies of selection between mutualist partners ignore interactions with third species and consequently overlook the impact of cheaters on evolution in the mutualism. Here, we explicitly investigate how the abundance of nectar-thieving ants (cheaters) influences selection in a pollination mutualism between bumble bees and the alpine skypilot, Polemonium viscosum. As suggested in past work with this species, bumble bees accounted for most of the seed production (78% +/- 6% [mean +/- SE]) in our high tundra study population and, in the absence of ants, exerted strong selection for large flowers. We tested for indirect effects of ant abundance on seed set through bumble bee pollination services (pollen delivery and pollen export) and a direct effect through flower damage. Ants reduced seed set per flower by 20% via flower damage. As ant density increased within experimental patches, the rate of flower damage rose, but pollen delivery and export did not vary significantly, showing that indirect effects of increased cheater abundance on pollinator service are negligible in this system. To address how ants affect selection for plant participation in the pollination mutualism we tested the impact of ant abundance on selection for bumble bee-mediated pollination. Results show that the impact of ants on fitness (seed set) accruing under bumble bee pollination is density dependent in P. viscosum. Selection for bumble bee pollination declined with increasing ant abundance in experimental patches, as predicted if cheaters constrain fitness returns of mutualist partner services. We also examined how ant abundance influences selection on flower size, a key component of plant investment in bumble bee pollination. We predicted that direct effects of ants would constrain bumble bee selection for large flowers. However, selection on flower size was significantly positive over a wide range of ant abundance (20-80% of plants visited by ants daily). Although high cheater abundance reduces the fitness returns of bumble bee pollination, it does not completely eliminate selection for bumble bee attraction in P. viscosum.

Social variables exert selective pressures in the evolution and form of primate mimetic musculature.

PubMed

Burrows, Anne M; Li, Ly; Waller, Bridget M; Micheletta, Jerome

2016-04-01

Mammals use their faces in social interactions more so than any other vertebrates. Primates are an extreme among most mammals in their complex, direct, lifelong social interactions and their frequent use of facial displays is a means of proximate visual communication with conspecifics. The available repertoire of facial displays is primarily controlled by mimetic musculature, the muscles that move the face. The form of these muscles is, in turn, limited by and influenced by phylogenetic inertia but here we use examples, both morphological and physiological, to illustrate the influence that social variables may exert on the evolution and form of mimetic musculature among primates. Ecomorphology is concerned with the adaptive responses of morphology to various ecological variables such as diet, foliage density, predation pressures, and time of day activity. We present evidence that social variables also exert selective pressures on morphology, specifically using mimetic muscles among primates as an example. Social variables include group size, dominance 'style', and mating systems. We present two case studies to illustrate the potential influence of social behavior on adaptive morphology of mimetic musculature in primates: (1) gross morphology of the mimetic muscles around the external ear in closely related species of macaque (Macaca mulatta and Macaca nigra) characterized by varying dominance styles and (2) comparative physiology of the orbicularis oris muscle among select ape species. This muscle is used in both facial displays/expressions and in vocalizations/human speech. We present qualitative observations of myosin fiber-type distribution in this muscle of siamang (Symphalangus syndactylus), chimpanzee (Pan troglodytes), and human to demonstrate the potential influence of visual and auditory communication on muscle physiology. In sum, ecomorphologists should be aware of social selective pressures as well as ecological ones, and that observed morphology might reflect a compromise between the demands of the physical and the social environments. © 2016 Anatomical Society.

Intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a US Great Plains’ precipitation gradient: implications for grassland restoration with climate change

PubMed Central

Johnson, Loretta C; Olsen, Jacob T; Tetreault, Hannah; DeLaCruz, Angel; Bryant, Johnny; Morgan, Theodore J; Knapp, Mary; Bello, Nora M; Baer, Sara G; Maricle, Brian R

2015-01-01

Identifying suitable genetic stock for restoration often employs a ‘best guess’ approach. Without adaptive variation studies, restoration may be misguided. We test the extent to which climate in central US grasslands exerts selection pressure on a foundation grass big bluestem (Andropogon gerardii), widely used in restorations, and resulting in local adaptation. We seeded three regional ecotypes of A. gerardii in reciprocal transplant garden communities across 1150 km precipitation gradient. We measured ecological responses over several timescales (instantaneous gas exchange, medium-term chlorophyll absorbance, and long-term responses of establishment and cover) in response to climate and biotic factors and tested if ecotypes could expand range. The ecotype from the driest region exhibited greatest cover under low rainfall, suggesting local adaptation under abiotic stress. Unexpectedly, no evidence for cover differences between ecotypes exists at mesic sites where establishment and cover of all ecotypes were low, perhaps due to strong biotic pressures. Expression of adaptive differences is strongly environment specific. Given observed adaptive variation, the most conservative restoration strategy would be to plant the local ecotype, especially in drier locations. With superior performance of the most xeric ecotype under dry conditions and predicted drought, this ecotype may migrate eastward, naturally or with assistance in restorations. PMID:26240607

Discovery of Culex pipiens associated tunisia virus: a new ssRNA(+) virus representing a new insect associated virus family

PubMed Central

Bigot, Diane; Atyame, Célestine M; Weill, Mylène; Justy, Fabienne

2018-01-01

Abstract In the global context of arboviral emergence, deep sequencing unlocks the discovery of new mosquito-borne viruses. Mosquitoes of the species Culex pipiens, C. torrentium, and C. hortensis were sampled from 22 locations worldwide for transcriptomic analyses. A virus discovery pipeline was used to analyze the dataset of 0.7 billion reads comprising 22 individual transcriptomes. Two closely related 6.8 kb viral genomes were identified in C. pipiens and named as Culex pipiens associated tunisia virus (CpATV) strains Ayed and Jedaida. The CpATV genome contained four ORFs. ORF1 possessed helicase and RNA-dependent RNA polymerase (RdRp) domains related to new viral sequences recently found mainly in dipterans. ORF2 and 4 contained a capsid protein domain showing strong homology with Virgaviridae plant viruses. ORF3 displayed similarities with eukaryotic Rhoptry domain and a merozoite surface protein (MSP7) domain only found in mosquito-transmitted Plasmodium, suggesting possible interactions between CpATV and vertebrate cells. Estimation of a strong purifying selection exerted on each ORFs and the presence of a polymorphism maintained in the coding region of ORF3 suggested that both CpATV sequences are genuine functional viruses. CpATV is part of an entirely new and highly diversified group of viruses recently found in insects, and that bears the genomic hallmarks of a new viral family. PMID:29340209

Functional interaction between responses to lactic acidosis and hypoxia regulates genomic transcriptional outputs

PubMed Central

Tang, Xiaohu; Lucas, Joseph E.; Chen, Julia Ling-Yu; LaMonte, Gregory; Wu, Jianli; Wang, Michael Changsheng; Koumenis, Constantinos; Chi, Jen-Tsan

2011-01-01

Within solid tumor microenvironments, lactic acidosis and hypoxia each have powerful effects on cancer pathophysiology. However, the influence that these processes exert on each other is unknown. Here we report that a significant portion of the transcriptional response to hypoxia elicited in cancer cells is abolished by simultaneous exposure to lactic acidosis. In particular, lactic acidosis abolished stabilization of HIF-1α protein which occurs normally under hypoxic conditions. In contrast, lactic acidosis strongly synergized with hypoxia to activate the unfolded protein response (UPR) and an inflammatory response, displaying a strong similarity to ATF4-driven amino acid deprivation responses (AAR). In certain breast tumors and breast tumor cells examined, an integrative analysis of gene expression and array CGH data revealed DNA copy number alterations at the ATF4 locus, an important activator of the UPR/AAR pathway. In this setting, varying ATF4 levels influenced the survival of cells after exposure to hypoxia and lactic acidosis. Our findings reveal that the condition of lactic acidosis present in solid tumors inhibits canonical hypoxia responses and activates UPR and inflammation responses. Further, they suggest that ATF4 status may be a critical determinant of the ability of cancer cells to adapt to oxygen and acidity fluctuations in the tumor microenvironment, perhaps linking short-term transcriptional responses to long-term selection for copy number alterations in cancer cells. PMID:22135092

Intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a US Great Plains' precipitation gradient: implications for grassland restoration with climate change.

PubMed

Johnson, Loretta C; Olsen, Jacob T; Tetreault, Hannah; DeLaCruz, Angel; Bryant, Johnny; Morgan, Theodore J; Knapp, Mary; Bello, Nora M; Baer, Sara G; Maricle, Brian R

2015-08-01

Identifying suitable genetic stock for restoration often employs a 'best guess' approach. Without adaptive variation studies, restoration may be misguided. We test the extent to which climate in central US grasslands exerts selection pressure on a foundation grass big bluestem (Andropogon gerardii), widely used in restorations, and resulting in local adaptation. We seeded three regional ecotypes of A. gerardii in reciprocal transplant garden communities across 1150 km precipitation gradient. We measured ecological responses over several timescales (instantaneous gas exchange, medium-term chlorophyll absorbance, and long-term responses of establishment and cover) in response to climate and biotic factors and tested if ecotypes could expand range. The ecotype from the driest region exhibited greatest cover under low rainfall, suggesting local adaptation under abiotic stress. Unexpectedly, no evidence for cover differences between ecotypes exists at mesic sites where establishment and cover of all ecotypes were low, perhaps due to strong biotic pressures. Expression of adaptive differences is strongly environment specific. Given observed adaptive variation, the most conservative restoration strategy would be to plant the local ecotype, especially in drier locations. With superior performance of the most xeric ecotype under dry conditions and predicted drought, this ecotype may migrate eastward, naturally or with assistance in restorations.

Violence against women in intimate relationships: explanations and suggestions for interventions as perceived by healthcare workers, local leaders, and trusted community members in a northern district of Vietnam.

PubMed

Jonzon, Robert; Vung, Nguyen Dang; Ringsberg, Karin C; Krantz, Gunilla

2007-01-01

This study explored professionals' and trusted community inhabitants' explanations of the violence between intimate partners and their suggestions for preventive activities. It was performed in a rural district in northern Vietnam. A total of 20 men and 20 women were strategically selected for focus-group discussions and the analyses followed the procedure for qualitative thematic content analysis. It was pointed out that violence against women was not discussed openly in the community and women subjected to violence kept silent and avoided seeking help in order not to reveal what was happening in the family. The informants perceived the violence as an interplay between individual and family-related factors and sociocultural norms and practices where Confucian ideology exerted a strong influence. When it came to prevention, there was a strong belief in educating the people and in enforcing policy and law. As described by the informants, traditional attitudes to gender roles and women's power disadvantage are found to be behind most of the explanations for intimate partner violence. Collaboration between sectors at local level, between the health sector and other bodies, and with community leaders as spokesmen would help to improve openness and reduce society's tolerance of violence against women. The mass media also have an important role to play.

Ungulate browsing maintains shrub diversity in the absence of episodic disturbance in seasonally-arid conifer forest

Treesearch

Burak K. Pekin; Michael J. Wisdom; Bryan A. Endress; Bridgett J. Naylor; Catherine G. Parks

2014-01-01

Ungulates exert a strong influence on the composition and diversity of vegetation communities. However, little is known about how ungulate browsing pressure interacts with episodic disturbances such as fire and stand thinning. We assessed shrub responses to variable browsing pressure by cattle and elk in fuels treated (mechanical removal of fuels followed by prescribed...

Seasonal moisture fluctuations four species of pocosin vegetation

Treesearch

George W. Wendel; Theodore G. Storey

1962-01-01

During the most severe burning conditions practically all of the living understory vegetation on pocosins may be consumed by fire (9). Even under less severe conditions leaves and branch tips are readily consumed. Whether the moisture content in the living vegetation is high, as it is in the spring, or low, as in the winter, exerts a strong influence on fuel...

Vinpocetine inhibits oligodendroglial precursor cell differentiation.

PubMed

Torres, Klintsy Julieta; Göttle, Peter; Kremer, David; Rivera, Jose Flores; Aguirre-Cruz, Lucinda; Corona, Teresa; Hartung, Hans-Peter; Küry, Patrick

2012-01-01

In multiple sclerosis during periods of remission a limited degree of myelin repair can be observed mediated by oligodendroglial precursor cells. Phosphodiesterase inhibitors act as anti-inflammatory agents and might hold promise for future multiple sclerosis treatment. To investigate whether phosphodiesterase inhibitors could also influence myelin repair. We stimulated primary oligodendroglial precursor cells with cilostazol, rolipram and vinpocetine and assessed their effects on repair related cellular processes. We found that vinpocetine exerted a strong negative effect on myelin expression while cilostazol and rolipram did not show such effects. In addition, vinpocetine decreased morphological complexities suggesting an overall negative impact on oligodendroglial cell maturation. We provide evidence that this is not mediated via a blockade of phosphodiesterase-1 but rather by inhibition of IĸB kinase. These findings suggest that vinpocetine via IĸB inhibition exerts a strong negative impact on oligodendroglial cell maturation and may therefore provide the rationale to restrict its application during periods of remission in multiple sclerosis patients. This is of particular interest since vinpocetine is widely used as a health supplement thought to act as a cognitive and memory enhancer for healthy people and patients with neurological or muscle diseases. Copyright © 2012 S. Karger AG, Basel.

Modeling the Sedimentation of Red Blood Cells in Flow under Strong External Magnetic Body Force using a Lattice Boltzmann Fictitious Domain Method

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

Shi, Xing; Lin, Guang

To model the sedimentation of the red blood cell (RBC) in a square duct and a circular pipe, the recently developed technique derived from the lattice Boltzmann method and the distributed Lagrange multiplier/fictitious domain method (LBM-DLM/FD) is extended to employ the mesoscopic network model for simulations of the sedimentation of the RBC in flow. The flow is simulated by the lattice Boltzmann method with a strong magnetic body force, while the network model is used for modeling RBC deformation. The fluid-RBC interactions are enforced by the Lagrange multiplier. The sedimentation of the RBC in a square duct and a circularmore » pipe is simulated, revealing the capacity of the current method for modeling the sedimentation of RBC in various flows. Numerical results illustrate that that the terminal setting velocity increases with the increment of the exerted body force. The deformation of the RBC has significant effect on the terminal setting velocity due to the change of the frontal area. The larger the exerted force is, the smaller the frontal area and the larger deformation of the RBC are.« less

Bronchodilatation by tachykinins and capsaicin in the mouse main bronchus.

PubMed Central

Manzini, S.

1992-01-01

1. The effect of sensory neuropeptides and capsaicin on basal and stimulated tone of mouse bronchial smooth muscle has been evaluated. 2. In basal conditions neither sensory neuropeptides (substance P, neurokinin A or calcitonin gene-related peptide (CGRP) nor capsaicin exerted any contractile effects. However, when a tonic contraction was induced with carbachol (1 microM) a prompt relaxation was induced by substance P (1- 100 nM) and by neurokinin A (1- 100 nM), with substance P being more potent. A second application of substance P was without effect. CGRP (10 nM) produced only a very small and erratic relaxation. Relaxation was also induced by capsaicin (1 microM), and this response could be evoked only once in each preparation. In 4 out of 6 preparations a cross-desensitization between substance P and capsaicin was observed. 3. The selective NK1 tachykinin agonist, [Pro9]-SP sulphone (1 microM), exerted potent bronchodilator actions on carbachol-contracted mouse bronchial preparations. In contrast, neither [beta Ala8]-NKA (4-10) nor [MePhe7]-NKB (both at a concentration of 1 microM), selective synthetic agonists for NK2 and NK3 receptors, exerted significant relaxant effects. Furthermore, the selective NK1 tachykinin antagonist, (+/-)-CP 96,345 (1 microM), abolished substance P (1 nM)- but not isoprenaline (0.1 microM)-induced relaxations. 4. Application of electrical field stimulation (EFS) (20 Hz, supramaximal voltage, 0.5 ms for 10 s) to carbachol-contracted preparations evoked a transient contraction followed by a relaxation. The tetrodotoxin-sensitive slow component of this relaxation was reduced following capsaicin desensitization. 5. In the presence of indomethacin (5 microM) the relaxation induced by substance P, capsaicin or EFS was suppressed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1380376

A prospective study of carpal tunnel syndrome: workplace and individual risk factors

PubMed Central

Burt, Susan; Deddens, James A; Crombie, Ken; Jin, Yan; Wurzelbacher, Steve; Ramsey, Jessica

2015-01-01

Objectives To quantify the risk for carpal tunnel syndrome (CTS) from workplace physical factors, particularly hand activity level and forceful exertion, while taking into account individual factors including age, gender, body mass index (BMI), and pre-existing medical conditions. Methods Three healthcare and manufacturing workplaces were selected for inclusion on the basis of range of exposure to hand activity level and forceful exertion represented by their jobs. Each study participants job tasks were observed and evaluated ’ onsite and videotaped for further analysis, including frequency and duration of exertion and postural deviation. Individual health assessment entailed electrodiagnostic testing of median and ulnar nerves, physical examination and questionnaires at baseline with annual follow-up for 2 years. Results The incidence of dominant hand CTS during the study was 5.11 per 100 person-years (29 cases). Adjusted HRs for dominant hand CTS were as follows: working with forceful exertion ≥20% but <60% of the time: 2.83 (1.18, 6.79) and ≥60% of the time vs <20%: 19.57 (5.96, 64.24), BMI ≥30 kg/m2 (obesity): 3.19 (1.28, 7.98). The American Conference for Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for hand activity level also predicted CTS, HR=1.40 (1.11, 1.78) for each unit increase in the TLV ratio, controlling for obesity and job strain. Conclusions Workplace and individual risk factors both contribute to the risk for CTS. Time spent in forceful exertion can be a greater risk for CTS than obesity if the job exposure is high. Preventive workplace efforts should target forceful exertions. PMID:23788614

Exercise-associated Excessive Dynamic Airway Collapse in Military Personnel.

PubMed

Weinstein, Daniel J; Hull, James E; Ritchie, Brittany L; Hayes, Jackie A; Morris, Michael J

2016-09-01

Evaluation of military personnel for exertional dyspnea can present a diagnostic challenge, given multiple unique factors that include wide variation in military deployment. Initial consideration is given to common disorders such as asthma, exercise-induced bronchospasm, and inducible laryngeal obstruction. Excessive dynamic airway collapse has not been reported previously as a cause of dyspnea in these individuals. To describe the clinical and imaging characteristics of military personnel with exertional dyspnea who were found to have excessive dynamic collapse of large airways during exercise. After deployment to Afghanistan or Iraq, 240 active U.S. military personnel underwent a standardized evaluation to determine the etiology of persistent dyspnea on exertion. Study procedures included full pulmonary function testing, impulse oscillometry, exhaled nitric oxide measurement, methacholine challenge testing, exercise laryngoscopy, cardiopulmonary exercise testing, and fiberoptic bronchoscopy. Imaging included high-resolution computed tomography with inspiratory and expiratory views. Selected individuals underwent further imaging with dynamic computed tomography. A total of five men and one woman were identified as having exercise-associated excessive dynamic airway collapse on the basis of the following criteria: (1) exertional dyspnea without resting symptoms, (2) focal expiratory wheezing during exercise, (3) functional collapse of the large airways during bronchoscopy, (4) expiratory computed tomographic imaging showing narrowing of a large airway, and (5) absence of underlying apparent pathology in small airways or pulmonary parenchyma. Identification of focal expiratory wheezing correlated with bronchoscopic and imaging findings. Among 240 military personnel evaluated after presenting with postdeployment exertional dyspnea, a combination of symptoms, auscultatory findings, imaging, and visualization of the airways by bronchoscopy identified six individuals with excessive dynamic central airway collapse as the sole apparent cause of dyspnea. Exercise-associated excessive dynamic airway collapse should be considered in the differential diagnosis of exertional dyspnea.

The evolution of colour polymorphism in British winter-active Lepidoptera in response to search image use by avian predators.

PubMed

Weir, Jamie C

2018-05-10

Phenotypic polymorphism in cryptic species is widespread. This may evolve in response to search image use by predators exerting negative frequency-dependent selection on intraspecific colour morphs, 'apostatic selection'. Evidence exists to indicate search image formation by predators and apostatic selection operating on wild prey populations, though not to demonstrate search image use directly resulting in apostatic selection. The present study attempted to address this deficiency, using British Lepidoptera active in winter as a model system. It has been proposed that the typically polymorphic wing colouration of these species represents an anti-search image adaptation against birds. To test (a) for search image-driven apostatic selection, dimorphic populations of artificial moth-like models were established in woodland at varying relative morph frequencies and exposed to predation by natural populations of birds. In addition, to test (b) whether abundance and degree of polymorphism are correlated across British winter-active moths, as predicted where search image use drives apostatic selection, a series of phylogenetic comparative analyses were conducted. There was a positive relationship between artificial morph frequency and probability of predation, consistent with birds utilizing search images and exerting apostatic selection. Abundance and degree of polymorphism were found to be positively correlated across British Lepidoptera active in winter, though not across all taxonomic groups analysed. This evidence is consistent with polymorphism in this group having evolved in response to search image-driven apostatic selection and supports the viability of this mechanism as a means by which phenotypic and genetic variation may be maintained in natural populations. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Chamomile and marigold tea: chemical characterization and evaluation of anticancer activity.

PubMed

Matić, Ivana Z; Juranić, Zorica; Savikin, Katarina; Zdunić, Gordana; Nađvinski, Neva; Gođevac, Dejan

2013-06-01

With the aim to evaluate the selectivity in the antitumor action, the cytotoxic activity of chamomile and marigold tea was tested against various malignant cell lines and against healthy immunocompetent peripheral blood mononuclear cells (PBMC). Chemical profiles of chamomile and marigold infusions and decoctions were analyzed by liquid chromatography/mass spectrometry; their total phenolic content and radical scavenging activity were determined, too. Results from present research demonstrate that chamomile and marigold tea exert selective dose-dependent cytotoxic action against target cancer cells. It is noteworthy that cytotoxicity of tea prepared from Calendula officinalis is remarkably higher in comparison to that from Matricaria recutita tea. The cytotoxic effect of chamomile tea is very weak to healthy PBMC, while the effect of marigold tea on PBMC is more pronounced. Marigold tea exerts highly selective antitumor effect especially to melanoma Fem-x cells in comparison to the action to normal healthy PBMC. Chemical analyses show that dominant phenolic compounds in examined infusions and decoctions are flavonoid glycosides and hydroxycinnamic acid derivatives. There are no considerable differences in total phenolic content and antioxidant activity between examined infusions. Antitumor potential of chamomile and marigold tea should be further investigated. Copyright © 2012 John Wiley & Sons, Ltd.

The Effect of Beta Adrenergic Blockade on Ratings of Perceived Exertion.

DTIC Science & Technology

1984-01-01

exrcis is uvo Hughson, et al. (47) investigated the effect of beta blockade using a single, 100-mg oral dose of metoprolol or matched placebo on 12...administered either placebo, propranolol (80 mug) or metoprolol (100 mug) in a double- blind, randomised manner. Before the muscle-strength tests were...The non-selective BABA propranolol and the selective agent metoprolol were compared with a placebo in a double blind cross-over design. Measurements

Raclopride or high-frequency stimulation of the subthalamic nucleus stops cocaine-induced motor stereotypy and restores related alterations in prefrontal basal ganglia circuits.

PubMed

Aliane, Verena; Pérez, Sylvie; Deniau, Jean-Michel; Kemel, Marie-Louise

2012-11-01

Motor stereotypy is a key symptom of various neurological or neuropsychiatric disorders. Neuroleptics or the promising treatment using deep brain stimulation stops stereotypies but the mechanisms underlying their actions are unclear. In rat, motor stereotypies are linked to an imbalance between prefrontal and sensorimotor cortico-basal ganglia circuits. Indeed, cortico-nigral transmission was reduced in the prefrontal but not sensorimotor basal ganglia circuits and dopamine and acetylcholine release was altered in the prefrontal but not sensorimotor territory of the dorsal striatum. Furthermore, cholinergic transmission in the prefrontal territory of the dorsal striatum plays a crucial role in the arrest of motor stereotypy. Here we found that, as previously observed for raclopride, high-frequency stimulation of the subthalamic nucleus (HFS STN) rapidly stopped cocaine-induced motor stereotypies in rat. Importantly, raclopride and HFS STN exerted a strong effect on cocaine-induced alterations in prefrontal basal ganglia circuits. Raclopride restored the cholinergic transmission in the prefrontal territory of the dorsal striatum and the cortico-nigral information transmissions in the prefrontal basal ganglia circuits. HFS STN also restored the N-methyl-d-aspartic-acid-evoked release of acetylcholine and dopamine in the prefrontal territory of the dorsal striatum. However, in contrast to raclopride, HFS STN did not restore the cortico-substantia nigra pars reticulata transmissions but exerted strong inhibitory and excitatory effects on neuronal activity in the prefrontal subdivision of the substantia nigra pars reticulata. Thus, both raclopride and HFS STN stop cocaine-induced motor stereotypy, but exert different effects on the related alterations in the prefrontal basal ganglia circuits. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Benzoin Schiff Bases: Design, Synthesis, and Biological Evaluation as Potential Antitumor Agents.

PubMed

Sabbah, Dima A; Al-Tarawneh, Fatima; Talib, Wamidh H; Sweidan, Kamal; Bardaweel, Sanaa K; Al-Shalabi, Eveen; Zhong, Haizhen A; Abu Sheikha, Ghassan; Abu Khalaf, Reema; Mubarak, Mohammad S

2018-04-12

Phosphoinositide 3-kinase α (PI3Kα) is an attractive target for anticancer drug design. Target compounds were designed to probe the significance of alcohol and imine moieties tailored on a benzoin scaffold to better understand the structure activity relation (SAR) and improve their biological activity as anticancer compounds. Chemical synthesis of the targeted compounds, biological evaluation tests against human colon adenocarcinoma (HCT-116), breast adenocarcinoma (MCF-7), and breast carcinoma (T47D) cell lines, as well as Glide docking studies were employed in this investigation. A new series of 1,2-diphenylimino ethanol was successfully synthesized and characterized by means of FT-IR, HRMS, NMR, and by elemental analysis. Biological screening revealed that the newly synthesized compounds inhibit PI3Kα activity in human colon adenocarcinoma (HCT-116), breast adenocarcinoma (MCF-7), and breast carcinoma (T47D) cell lines. Results additionally showed that these compounds exhibit selective antiproliferative activity, induce apoptosis, and suppress the VEGF production. Compounds 2b, 2d, and 2g displayed promising inhibitory activity in HCT-116 suggesting that hydrophobic and/or hydrogen bond-acceptor mediate(s) ligand-receptor interaction on o- and m-positions. Furthermore, compounds 2g, 2i, 2j, and 2h, bearing hydrophobic moiety on m- and p-position, exerted high antiproliferative activity in T47D and MCF-7 cells, whereas compound 2e showed selectivity against T47D and MCF-7. Molecular docking studies against PI3Kα and caspase-3 demonstrated a strong correlation between the predicted binding affinity (ΔGobsd) and IC50 values of prepared compounds for the caspase-3 model, implying that the cellulous inhibitory activity was caspase-3-dependent. Moreover, Glide docking against PI3Kα identified Ser774, Lys802, E849, V851, and Asp933 as key binding residues. The series exerted a potential PI3Kα inhibitory activity in human carcinoma cell lines expressing PI3Kα. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Perspectives on fish gonadotropins and their receptors.

PubMed

Levavi-Sivan, B; Bogerd, J; Mañanós, E L; Gómez, A; Lareyre, J J

2010-02-01

Teleosts lack a hypophyseal portal system and hence neurohormones are carried by nerve fibers from the preoptic region to the pituitary. The various cell types in the teleost pituitary are organized in discrete domains. Fish possess two gonadotropins (GtH) similar to FSH and LH in other vertebrates; they are heterodimeric hormones that consist of a common alpha subunit non-covalently associated with a hormone-specific beta subunit. In recent years the availability of molecular cloning techniques allowed the isolation of the genes coding for the GtH subunits in 56 fish species representing at least 14 teleost orders. Advanced molecular engineering provides the technology to produce recombinant GtHs from isolated cDNAs. Various expression systems have been used for the production of recombinant proteins. Recombinant fish GtHs were produced for carp, seabream, channel and African catfish, goldfish, eel, tilapia, zebrafish, Manchurian trout and Orange-spotted grouper. The hypothalamus in fishes exerts its regulation on the release of the GtHs via several neurohormones such as GnRH, dopamine, GABA, PACAP, IGF-I, norepinephrine, NPY, kisspeptin, leptin and ghrelin. In addition, gonadal steroids and peptides exert their effects on the gonadotropins either directly or via the hypothalamus. All these are discussed in detail in this review. In mammals, the biological activities of FSH and LH are directed to different gonadal target cells through the cell-specific expression of the FSH receptor (FSHR) and LH receptor (LHR), respectively, and the interaction between each gonadotropin-receptor couple is highly selective. In contrast, the bioactivity of fish gonadotropins seems to be less specific as a result of promiscuous hormone-receptor interactions, while FSHR expression in Leydig cells explains the strong steroidogenic activity of FSH in certain fish species. Copyright 2009 Elsevier Inc. All rights reserved.

Interaction of antitumor drug Sn(CH 3) 2Cl 2 with DNA and RNA

NASA Astrophysics Data System (ADS)

Nafisi, Shohreh; Sobhanmanesh, Amir; Esm-Hosseini, Majid; Alimoghaddam, Kamran; Tajmir-Riahi, Heidar Ali

2005-08-01

Sn(CH3)2Cl2 exerts its antitumor activity in a specific way. Unlike anticancer cis-Pt(NH3)2Cl2 drug which binds strongly to the nitrogen atoms of DNA bases, Sn(CH3)2Cl2 shows no major affinity towards base binding. Thus, the mechanism of action by which tinorganometallic compounds exert antitumor activity would be different from that of the cisplatin drug. The aim of this study was to examine the binding of Sn(CH3)2Cl2 with calf thymus DNA and yeast RNA in aqueous solutions at pH 7.1-6.6 with constant concentrations of DNA and RNA and various molar ratios of Sn(CH3)2Cl2/DNA (phosphate) and Sn(CH3)2Cl2/RNA of 1/40, 1/20, 1/10, 1/5. Fourier transform infrared (FTIR) and UV-visible difference spectroscopic methods were used to determine the Sn(CH3)2Cl2 binding mode, binding constant, sequence selectivity and structural variations of Sn(CH3)2Cl2/DNA and Sn(CH3)2Cl2/RNA complexes in aqueous solution. Sn(CH3)2Cl2 hydrolyzes in water to give Sn(CH3)2(OH)2 and [Sn(CH3)2(OH)(H2O)n]+ species. Spectroscopic evidence showed that interaction occurred mainly through (CH3)2Sn(IV) hydroxide and polynucleotide backbone phosphate group with overall binding constant of K(Sn(CH3)2Cl2-DNA)=1.47×105 M-1 and K(Sn(CH3)2Cl2-RNA)=7.33×105 M-1. Sn(CH3)2Cl2 induced no biopolymer conformational changes with DNA remaining in the B-family structure and RNA in A-conformation upon drug complexation.

Competing influences of greenhouse warming and aerosols on Asian summer monsoon circulation and rainfall

NASA Astrophysics Data System (ADS)

Lau, William Ka-Ming; Kim, Kyu-Myong

2017-05-01

In this paper, we have compared and contrasted competing influences of greenhouse gases (GHG) warming and aerosol forcing on Asian summer monsoon circulation and rainfall based on CMIP5 historical simulations. Under GHG-only forcing, the land warms much faster than the ocean, magnifying the pre-industrial climatological land-ocean thermal contrast and hemispheric asymmetry, i.e., warmer northern than southern hemisphere. A steady increasing warm-ocean-warmer-land (WOWL) trend has been in effect since the 1950's substantially increasing moisture transport from adjacent oceans, and enhancing rainfall over the Asian monsoon regions. However, under GHG warming, increased atmospheric stability due to strong reduction in mid-tropospheric and near surface relative humidity coupled to an expanding subsidence areas, associated with the Deep Tropical Squeeze (DTS, Lau and Kim, 2015b) strongly suppress monsoon convection and rainfall over subtropical and extratropical land, leading to a weakening of the Asian monsoon meridional circulation. Increased anthropogenic aerosol emission strongly masks WOWL, by over 60% over the northern hemisphere, negating to a large extent the rainfall increase due to GHG warming, and leading to a further weakening of the monsoon circulation, through increasing atmospheric stability, most likely associated with aerosol solar dimming and semi-direct effects. Overall, we find that GHG exerts stronger positive rainfall sensitivity, but less negative circulation sensitivity in SASM compared to EASM. In contrast, aerosols exert stronger negative impacts on rainfall, but less negative impacts on circulation in EASM compared to SASM.

[Advances in novel carrier systems of chemical constituents from spice volatile oils].

PubMed

Zhang, Jia-jia; Zhu, Yuan; Yu, Jiang-nan; Xu, Xi-ming

2015-10-01

Recent years, chemical constituents from spice volatile oils have gained worldwide concern owing to its multiple pharmacological effects and safety for using as the natural antibacterial agents. However, their poor dissolution, strong volatility, serious irritation, weak stability, easy oxidation and low bioavailability characteristics are the major obstacle in the preparation of effective oral formulation and practical application. Therefore, there is an urgent need to select a novel carrier system that can delivery the chemical constituents from spice volatile oils more efficiently with improving their stability as well as alleviating the irritation, and develop the functional food, health products and even medicine for exerting their pharmacological effects, which also is the focus and nodus of the research on their application. This review presents recent systematic studies on their novel carrier systems, including cyclodextrin inclusion complex, liposomes, nanoemulsions, nanoparticles, solid dispersion and so on, and summarizes the characteristics, application range and problems of each novel carrier systems, in order to provide some beneficial thoughts in further developing new products of chemical constituents from spice volatile oils.

Haemotoxic snake venoms: their functional activity, impact on snakebite victims and pharmaceutical promise.

PubMed

Slagboom, Julien; Kool, Jeroen; Harrison, Robert A; Casewell, Nicholas R

2017-06-01

Snake venoms are mixtures of numerous proteinacious components that exert diverse functional activities on a variety of physiological targets. Because the toxic constituents found in venom vary from species to species, snakebite victims can present with a variety of life-threatening pathologies related to the neurotoxic, cytotoxic and haemotoxic effects of venom. Of the 1·8 million people envenomed by snakes every year, up to 125 000 die, while hundreds of thousands survive only to suffer with life-changing long-term morbidity. Consequently, snakebite is one of the world's most severe neglected tropical diseases. Many snake venoms exhibit strong haemotoxic properties by interfering with blood pressure, clotting factors and platelets, and by directly causing haemorrhage. In this review we provide an overview of the functional activities of haemotoxic venom proteins, the pathologies they cause in snakebite victims and how their exquisite selectivity and potency make them amenable for use as therapeutic and diagnostic tools relevant for human medicine. © 2017 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

Calcification response of a key phytoplankton family to millennial-scale environmental change.

PubMed

McClelland, H L O; Barbarin, N; Beaufort, L; Hermoso, M; Ferretti, P; Greaves, M; Rickaby, R E M

2016-09-28

Coccolithophores are single-celled photosynthesizing marine algae, responsible for half of the calcification in the surface ocean, and exert a strong influence on the distribution of carbon among global reservoirs, and thus Earth's climate. Calcification in the surface ocean decreases the buffering capacity of seawater for CO 2 , whilst photosynthetic carbon fixation has the opposite effect. Experiments in culture have suggested that coccolithophore calcification decreases under high CO 2 concentrations ([CO 2 (aq)]) constituting a negative feedback. However, the extent to which these results are representative of natural populations, and of the response over more than a few hundred generations is unclear. Here we describe and apply a novel rationale for size-normalizing the mass of the calcite plates produced by the most abundant family of coccolithophores, the Noëlaerhabdaceae. On average, ancient populations subjected to coupled gradual increases in [CO 2 (aq)] and temperature over a few million generations in a natural environment become relatively more highly calcified, implying a positive climatic feedback. We hypothesize that this is the result of selection manifest in natural populations over millennial timescales, so has necessarily eluded laboratory experiments.

HIV: current opinion in escapology.

PubMed

Klenerman, Paul; Wu, Ying; Phillips, Rodney

2002-08-01

Much recent work strongly supports the hypothesis that CD8(+) T lymphocytes (CTLs) exert important immune control over HIV and so are a major selective force in its evolution. We analyse this host-pathogen interplay and focus on new data that describe the overall 'effectiveness' of CTL responses (strength, spread, specificity and 'stamina') and the mechanisms by which HIV may evade this suppressive activity. CTLs directed against HIV recognise very large numbers of distinct epitopes across the genome, are largely functional, turn over rapidly, and possess a phenotype that is distinct from CD8(+) lymphocytes specific for other viruses. Mutation of HIV epitopes that alters or abolishes CTL recognition altogether appears to be the most important immune escape mechanism, as the variation that HIV generates defies the limits of the T cell repertoire. However, this immune evasion is still only well-studied in a few patients. The rules that govern immune escape, and the ultimate limits of CTL capacity to deal with the variant epitopes that currently circulate, are not understood. This information will determine the feasibility of current vaccine approaches that, so far, make no provision for the enormous antigenic plasticity of HIV.

Soil invertebrate fauna enhances grassland succession and diversity.

PubMed

De Deyn, Gerlinde B; Raaijmakers, Ciska E; Zoomer, H Rik; Berg, Matty P; de Ruiter, Peter C; Verhoef, Herman A; Bezemer, T Martijn; van der Putten, Wim H

2003-04-17

One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.

Facies-related fracturing in turbidites: insights from the Marnoso-Arenacea Fm. (Northern Apennines, Italy)

NASA Astrophysics Data System (ADS)

Ogata, Kei; Storti, Fabrizio; Balsamo, Fabrizio; Bedogni, Enrico; Tinterri, Roberto; Fetter, Marcos; Gomes, Leonardo; Hatushika, Raphael

2016-04-01

Natural fractures deeply influence subsurface fluid flow, exerting a primary control on resources like aquifers, hydrocarbons and geothermal reservoirs, and on environmental issues like CO2 storage and nuclear waste disposal. In layered sedimentary rocks, depositional processes-imprinted rock rheology favours the development of both mechanical anisotropy and heterogeneity on a wide range of scales, and are thus expected to strongly influence location and frequency of fractures. To better constrain the contribution of stratigraphic, sedimentological and petrophysical attributes, we performed a high-resolution, multidisciplinary study on a selected stratigraphic interval of jointed foredeep turbidites in the Miocene Marnoso-arenacea Formation (Northern Apennines, Italy), which are characterised by a great lateral and vertical variability of grain-size and depositional structures. Statistical relationships among field and laboratory data significantly improve when the single facies scale is considered, and, for similar facies recording different evolutionary stages of the parent turbidity currents, we observed a direct correlation between the three-dimensional anisotropies of rock hardness tensors and the normalized fracture frequencies, testifying for the primary sedimentary flow-related control on fracture distributions.

Risky behavior and its effect on survival: snowshoe hare behavior under varying moonlight conditions

USGS Publications Warehouse

Gigliotti, Laura C.; Diefenbach, Duane R.

2018-01-01

Predation and predation risk can exert strong influences on the behavior of prey species. However, risk avoidance behaviors may vary among populations of the same species. We studied a population of snowshoe hares (Lepus americanus) near the southern edge of their range, in Pennsylvania. This population occupies different habitat types, experiences different environmental conditions, and are exposed to different predator species and densities than northern hare populations; therefore, they might exhibit differences in risk avoidance behaviors. We analyzed hare survival, movement rates, and habitat use under different levels of predation risk, as indexed by moonlight. Similar to previous work, we found snowshoe hare survival decreased with increased moon illumination during the winter, but we found differences in behavioral responses to increased predation risk. We found that snowshoe hares did not reduce movement rates during high‐risk nights, but instead found that hares selected areas with denser canopy cover, compared to low‐risk nights. We suggest that behavioral plasticity in response to predation risk allows populations of the same species to respond to localized conditions.

The Steppengrille (Gryllus spec./assimilis): Selective Filters and Signal Mismatch on Two Time Scales

PubMed Central

Rothbart, Matti Michael; Hennig, Ralf Matthias

2012-01-01

In Europe, several species of crickets are available commercially as pet food. Here we investigated the calling song and phonotactic selectivity for sound patterns on the short and long time scales for one such a cricket, Gryllus spec., available as “Gryllus assimilis”, the Steppengrille, originally from Ecuador. The calling song consisted of short chirps (2–3 pulses, carrier frequency: 5.0 kHz) emitted with a pulse period of 30.2 ms and chirp rate of 0.43 per second. Females exhibited high selectivity on both time scales. The preference for pulse period peaked at 33 ms which was higher then the pulse period produced by males. Two consecutive pulses per chirp at the correct pulse period were already sufficient for positive phonotaxis. The preference for the chirp pattern was limited by selectivity for small chirp duty cycles and for chirp periods between 200 ms and 500 ms. The long chirp period of the songs of males was unattractive to females. On both time scales a mismatch between the song signal of the males and the preference of females was observed. The variability of song parameters as quantified by the coefficient of variation was below 50% for all temporal measures. Hence, there was not a strong indication for directional selection on song parameters by females which could account for the observed mismatch. The divergence of the chirp period and female preference may originate from a founder effect, when the Steppengrille was cultured. Alternatively the mismatch was a result of selection pressures exerted by commercial breeders on low singing activity, to satisfy customers with softly singing crickets. In the latter case the prominent divergence between male song and female preference was the result of domestication and may serve as an example of rapid evolution of song traits in acoustic communication systems. PMID:22970154

TOWARDS A GENERIC PBPK MODEL OF PYRETHROID PESTICIDES: MODELING DELTAMETHRIN AND PERMETHIN IN THE RAT

EPA Science Inventory

Pyrethroids have emerged as a major class of insecticide due to their selective potency in insects and their relatively low potency in mammalian studies. Pyrethroids exert toxicity by binding to voltage-gated sodium channels, thereby eliciting excitatory neurotoxicity. The Food...

TOWARDS A GENERIC PBPK MODEL OF PYRETHROID PESTICIDES: MODELING DELTAMETHRIN AND PERMETHRIN IN THE RAT

EPA Science Inventory

Pyrethroids have emerged as a major class of insecticide due to their selective potency in insects and their relatively low potency in mammalian studies. Pyrethroids exert toxicity by binding to voltage-gated sodium channels, thereby eliciting excitatory neurotoxicity. The Fo...

METHODS DEVELOPMENT FOR THE DETERMINATION OF SELECTED ORGANOTINS IN DRINKING WATER

EPA Science Inventory

Organotin compounds, due to their versatility, have been exploited for use in a plethora of diverse applications with the intent to benefit human society. And, as a consequence, they have exerted a profound effect on the environment and the economy. For example, organotin compo...

Selective targeting of KRAS-Mutant cells by miR-126 through repression of multiple genes essential for the survival of KRAS-Mutant cells

PubMed Central

Hara, Toshifumi; Jones, Matthew F.; Subramanian, Murugan; Li, Xiao Ling; Ou, Oliver; Zhu, Yuelin; Yang, Yuan; Wakefield, Lalage M.; Hussain, S. Perwez; Gaedcke, Jochen; Ried, Thomas; Luo, Ji; Caplen, Natasha J.; Lal, Ashish

2014-01-01

MicroRNAs (miRNAs) regulate the expression of hundreds of genes. However, identifying the critical targets within a miRNA-regulated gene network is challenging. One approach is to identify miRNAs that exert a context-dependent effect, followed by expression profiling to determine how specific targets contribute to this selective effect. In this study, we performed miRNA mimic screens in isogenic KRAS-Wild-type (WT) and KRAS-Mutant colorectal cancer (CRC) cell lines to identify miRNAs selectively targeting KRAS-Mutant cells. One of the miRNAs we identified as a selective inhibitor of the survival of multiple KRAS-Mutant CRC lines was miR-126. In KRAS-Mutant cells, miR-126 over-expression increased the G1 compartment, inhibited clonogenicity and tumorigenicity, while exerting no effect on KRAS-WT cells. Unexpectedly, the miR-126-regulated transcriptome of KRAS-WT and KRAS-Mutant cells showed no significant differences. However, by analyzing the overlap between miR-126 targets with the synthetic lethal genes identified by RNAi in KRAS-Mutant cells, we identified and validated a subset of miR-126-regulated genes selectively required for the survival and clonogenicity of KRAS-Mutant cells. Our strategy therefore identified critical target genes within the miR-126-regulated gene network. We propose that the selective effect of miR-126 on KRAS-Mutant cells could be utilized for the development of targeted therapy for KRAS mutant tumors. PMID:25245095

Fire exclusion as a disturbance in the temperate forests of the USA: examples from longleaf pine forests

Treesearch

W. Keith Moser; Dale D. Wade

2005-01-01

Forest fires are a disturbance where the effects can range from benign to extreme devastation within a given ecosystem. The stage of stand development coupled with prior management dictates the amount and composition of potential fuels. Thus, fire policy exerts a strong influence on fire effects. Changes in cultural acceptance and use of tire typically drive fire...

Pre-Service Teachers' Belief Sources about Learning and Teaching: An Exploration with the Consideration of the Educational Programme Nature

ERIC Educational Resources Information Center

Debreli, Emre

2016-01-01

It is often said that beliefs determine the ways teachers think and act in classrooms. There is now strong evidence that teachers' beliefs are formed during their previous education as students, and that they exert a powerful influence throughout their careers. However, only little has yet been done on the teacher education programmes' influence…

Comparison of modeling approaches for carbon partitioning: Impact on estimates of global net primary production and equilibrium biomass of woody vegetation from MODIS GPP

Treesearch

Takeshi Ise; Creighton M. Litton; Christian P. Giardina; Akihiko Ito

2010-01-01

Partitioning of gross primary production (GPP) to aboveground versus belowground, to growth versus respiration, and to short versus long�]lived tissues exerts a strong influence on ecosystem structure and function, with potentially large implications for the global carbon budget. A recent meta-analysis of forest ecosystems suggests that carbon partitioning...

Does clutch size evolve in response to parasites and immunocompetence?

USGS Publications Warehouse

Martin, T.E.; Moller, A.P.; Merino, S.; Clobert, J.

2001-01-01

Parasites have been argued to influence clutch size evolution, but past work and theory has largely focused on within-species optimization solutions rather than clearly addressing among-species variation. The effects of parasites on clutch size variation among species can be complex, however, because different parasites can induce age-specific differences in mortality that can cause clutch size to evolve in different directions. We provide a conceptual argument that differences in immunocompetence among species should integrate differences in overall levels of parasite-induced mortality to which a species is exposed. We test this assumption and show that mortality caused by parasites is positively correlated with immunocompetence measured by cell-mediated measures. Under life history theory, clutch size should increase with increased adult mortality and decrease with increased juvenile mortality. Using immunocompetence as a general assay of parasite-induced mortality, we tested these predictions by using data for 25 species. We found that clutch size increased strongly with adult immunocompetence. In contrast, clutch size decreased weakly with increased juvenile immunocompetence. But, immunocompetence of juveniles may be constrained by selection on adults, and, when we controlled for adult immunocompetence, clutch size decreased with juvenile immunocompetence. Thus, immunocompetence seems to reflect evolutionary differences in parasite virulence experienced by species, and differences in age-specific parasite virulence appears to exert opposite selection on clutch size evolution.

The cytotoxic action of the CD56+ fraction of cytokine-induced killer cells against a K562 cell line is mainly restricted to the natural killer cell subset.

PubMed

Chieregato, Katia; Zanon, Cristina; Castegnaro, Silvia; Bernardi, Martina; Amati, Eliana; Sella, Sabrina; Rodeghiero, Francesco; Astori, Giuseppe

2017-01-01

Cytokine-induced killer cells are polyclonal T cells generated ex vivo and comprise two main subsets: the CD56- fraction, possessing an alloreactive potential caused by T cells (CD3+CD56-), and the CD56+ fraction, characterised by a strong antitumour capacity induced by natural killer-like T cells (NK-like T, CD3+CD56+) and natural killer cells (NK, CD3-CD56+ bright). We investigated the cytotoxic action of selected CD56+ cell subpopulations against a human chronic myeloid leukaemia (K562) cell line. After immunomagnetic selection of the CD56+ cell fraction, NK bright cells (CD3-CD56+ bright) and two subsets of NK-like T cells (CD3+CD56+), called NK-like T CD56 dim and NK-like T CD56 bright, could be identified. The cytotoxic effect against K562 cells was mainly exerted by the NK bright subpopulation and resulted to be inversely correlated with the percentage of NK-like T CD56 dim cells in the culture. The lytic action appeared to be independent of cell degranulation as suggested by the lack of change in the expression of CD107a. We conclude that the cytotoxic action of CD56+ cells against a K562 cell line is mainly due to the NK cells.

Comprehensive interactome of Otx2 in the adult mouse neural retina.

PubMed

Fant, Bruno; Samuel, Alexander; Audebert, Stéphane; Couzon, Agnès; El Nagar, Salsabiel; Billon, Nathalie; Lamonerie, Thomas

2015-11-01

The Otx2 homeodomain transcription factor exerts multiple functions in specific developmental contexts, probably through the regulation of different sets of genes. Protein partners of Otx2 have been shown to modulate its activity. Therefore, the Otx2 interactome may play a key role in selecting a precise target-gene repertoire, hence determining its function in a specific tissue. To address the nature of Otx2 interactome, we generated a new recombinant Otx2(CTAP-tag) mouse line, designed for protein complexes purification. We validated this mouse line by establishing the Otx2 interactome in the adult neural retina. In this tissue, Otx2 is thought to have overlapping function with its paralog Crx. Our analysis revealed that, in contrary to Crx, Otx2 did not develop interactions with proteins that are known to regulate phototransduction genes but showed specific partnership with factors associated with retinal development. The relationship between Otx2 and Crx in the neural retina should therefore be considered as complementarity rather than redundancy. Furthermore, study of the Otx2 interactome revealed strong associations with RNA processing and translation machineries, suggesting unexpected roles for Otx2 in the regulation of selected target genes all along the transcription/translation pathway. The Otx2(CTAP-tag) line, therefore, appears suitable for a systematic approach to Otx2 protein-protein interactions. genesis 53:685-694, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

KRAS Testing

PubMed Central

Shackelford, Rodney E.; Whitling, Nicholas A.; McNab, Patricia; Japa, Shanker

2012-01-01

Activating point mutations in codons 12, 13, and 61 of the KRAS proto-oncogene are common in colorectal, non–small cell lung, pancreatic, and thyroid cancers. Constitutively activated KRAS mutations are strongly associated with a resistance to anti–epidermal growth factor receptor (EGFR) therapies, such as panitumumab and cetuximab used for treating metastatic colorectal carcinoma and EGFR tyrosine inhibitors used for advanced non–small cell lung cancers. Since anti-EGFR therapies are costly and may exert deleterious effects on individuals without activating mutations, KRAS mutation testing is recommended prior to the initiation of anti-EGFR therapy for these malignancies. The goal of this review is to summarize the KRAS mutation testing methods. Testing is now routinely requested in the clinical practice to provide data to assign the most appropriate anticancer chemotherapy for each given patient. Review of the most relevant literature was performed. Several areas were considered: ordering of the test, selection of the sample to be tested, and review of the testing methodologies. We found that several different methods are used for clinical KRAS mutation testing. Each of the methodologies is described, and information is provided about their performance, cost, turnaround times, detection limits, sensitivities, and specificities. We also provided “tips” for the appropriate selection and preparation of the sample to be tested. This is an important aspect of KRAS testing for clinical use, as the results of the test will affect clinical decisions with consequences for the patient. PMID:23264846

Host group formation decreases exposure to vector-borne disease: a field experiment in a 'hotspot' of West Nile virus transmission.

PubMed

Krebs, Bethany L; Anderson, Tavis K; Goldberg, Tony L; Hamer, Gabriel L; Kitron, Uriel D; Newman, Christina M; Ruiz, Marilyn O; Walker, Edward D; Brawn, Jeffrey D

2014-12-07

Animals can decrease their individual risk of predation by forming groups. The encounter-dilution hypothesis extends the potential benefits of gregariousness to biting insects and vector-borne disease by predicting that the per capita number of insect bites should decrease within larger host groups. Although vector-borne diseases are common and can exert strong selective pressures on hosts, there have been few tests of the encounter-dilution effect in natural systems. We conducted an experimental test of the encounter-dilution hypothesis using the American robin (Turdus migratorius), a common host species for the West Nile virus (WNV), a mosquito-borne pathogen. By using sentinel hosts (house sparrows, Passer domesticus) caged in naturally occurring communal roosts in the suburbs of Chicago, we assessed sentinel host risk of WNV exposure inside and outside of roosts. We also estimated per capita host exposure to infected vectors inside roosts and outside of roosts. Sentinel birds caged inside roosts seroconverted to WNV more slowly than those outside of roosts, suggesting that social groups decrease per capita exposure to infected mosquitoes. These results therefore support the encounter-dilution hypothesis in a vector-borne disease system. Our results suggest that disease-related selective pressures on sociality may depend on the mode of disease transmission. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Proteasome inhibitory, antioxidant, and synergistic antibacterial and anticandidal activity of green biosynthesized magnetic Fe3O4 nanoparticles using the aqueous extract of corn (Zea mays L.) ear leaves.

PubMed

Patra, Jayanta Kumar; Ali, Md Sarafat; Oh, In-Gyung; Baek, Kwang-Hyun

2017-03-01

Herein, Fe 3 O 4 nanoparticles synthesized using aqueous extract of corn ear leaves were investigated for proteasome inhibitory activity, antioxidant activity, synergistic antibacterial, and anticandidal potential. The UV-Vis spectrum displayed an absorption band at 355 nm that indicated the formation of nano-sized Fe 3 O 4 particles. Vibrating sample magnetometer analysis revealed its superparamagnetic nature. Fe 3 O 4 nanoparticles exhibited strong proteasome inhibitory potential and antioxidant activity and exerted strong synergistic antibacterial and anticandidal activity. Its significant proteasome inhibitory potential could be useful in cancer treatment and drug delivery. Furthermore, strong antioxidant, antibacterial, and anticandidal activity make them a promising candidate for biomedical and pharmaceutical applications.

Anti-amnesic effects of Ganoderma species: A possible cholinergic and antioxidant mechanism.

PubMed

Kaur, Ravneet; Singh, Varinder; Shri, Richa

2017-08-01

Mushrooms are valued for their nutritional as well as medicinal properties. Ganoderma species are used traditionally to treat neurological disorders but scientific evidence for this is insufficient. The present study was designed to systematically evaluate the anti-amnesic effect of selected Ganoderma species i.e. G. mediosinense and G. ramosissimum. Extracts of selected mushroom species were evaluated for their antioxidant activity and acetylcholinesterase (AChE) inhibition using in-vitro assays (DPPH and Ellman tests respectively). The anti-amnesic potential of the most active extract (i.e. 70% methanol extract of G. mediosinense) was confirmed using mouse model of scopolamine-induced amnesia. Mice were treated with bioactive extract and donepezil once orally before the induction of amnesia. Cognitive functions were evaluated using passive shock avoidance (PSA) and novel object recognition (NOR) tests. The effect on brain AChE activity, brain oxidative stress (TBARS level) and neuronal damage (H & E staining) were also assessed. In-vitro results showed strong antioxidant and AChE inhibitory activities by G. mediosinense extract (GME). Therefore, it was selected for in-vivo studies. GME pre-treatment (800mg/kg, p.o.) reversed the effect of scopolamine in mice, evident by significant decrease (p <0.05) in the transfer latency time and increase in object recognition index in PSA and NOR, respectively. GME significantly reduced the brain AChE activity and oxidative stress. Histopathological examination of brain tissues showed decrease in vacuolated cytoplasm and increase in pyramidal cells in brain hippocampal and cortical regions. GME exerts anti-amnesic effect through AChE inhibition and antioxidant mechanisms. Copyright © 2017. Published by Elsevier Masson SAS.

Metabolomic profiling of the nectars of Aquilegia pubescens and A. canadensis

USDA-ARS?s Scientific Manuscript database

To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the...

A candidate anti-HIV reservoir compound, auranofin, exerts a selective ‘anti-memory' effect by exploiting the baseline oxidative status of lymphocytes

PubMed Central

Chirullo, B; Sgarbanti, R; Limongi, D; Shytaj, I L; Alvarez, D; Das, B; Boe, A; DaFonseca, S; Chomont, N; Liotta, L; III Petricoin, E; Norelli, S; Pelosi, E; Garaci, E; Savarino, A; Palamara, A T

2013-01-01

Central memory (TCM) and transitional memory (TTM) CD4+ T cells are known to be the major cellular reservoirs for HIV, as these cells can harbor a transcriptionally silent form of viral DNA that is not targeted by either the immune system or current antiretroviral drug regimens. In the present study, we explored the molecular bases of the anti-HIV reservoir effects of auranofin (AF), a pro-oxidant gold-based drug and a candidate compound for a cure of AIDS. We here show that TCM and TTM lymphocytes have lower baseline antioxidant defenses as compared with their naive counterpart. These differences are mirrored by the effects exerted by AF on T-lymphocytes: AF was able to exert a pro-differentiating and pro-apoptotic effect, which was more pronounced in the memory subsets. AF induced an early activation of the p38 mitogen-activated protein kinase (p38 MAPK) followed by mitochondrial depolarization and a final burst in intracellular peroxides. The pro-differentiating effect was characterized by a downregulation of the CD27 marker expression. Interestingly, AF-induced apoptosis was inhibited by pyruvate, a well-known peroxide scavenger, but pyruvate did not inhibit the pro-differentiating effect of AF, indicating that the pro-apoptotic and pro-differentiating effects involve different pathways. In conclusion, our results demonstrate that AF selectively targets the TCM/TTM lymphocyte subsets, which encompass the HIV reservoir, by affecting redox-sensitive cell death pathways. PMID:24309931

GASP. III. JO36: A Case of Multiple Environmental Effects at Play?

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

Fritz, Jacopo; Bruzual, Gustavo; Cervantes Sodi, Bernardo

The so-called jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped from the main body of the galaxy. Several works have strongly suggested ram pressure stripping to be the mechanism driving this phenomenon. Here, we focus on one of these objects, drawn from a sample of optically selected jellyfish galaxies, and use it to validate sinopsis, the spectral fitting code that will be used for the analysis of the GASP (GAs Stripping Phenomena in galaxies with MUSE) survey, and study the spatial distribution and physical properties of the gas and stellar populations inmore » this galaxy. We compare the model spectra to those obtained with gandalf, a code with similar features widely used to interpret the kinematics of stars and gas in galaxies from IFU data. We find that sinopsis can reproduce the pixel-by-pixel spectra of this galaxy at least as well as gandalf does, providing reliable estimates of the underlying stellar absorption to properly correct the nebular gas emission. Using these results, we find strong evidences of a double effect of ram pressure exerted by the intracluster medium onto the gas of the galaxy. A moderate burst of star formation, dating between 20 and 500 Myr ago and involving the outer parts of the galaxy more strongly than the inner regions, was likely induced by a first interaction of the galaxy with the intracluster medium. Stripping by ram pressure, plus probable gas depletion due to star formation, contributed to create a truncated ionized gas disk. The presence of an extended stellar tail on only one side of the disk points instead to another kind of process, likely gravitational interaction by a fly-by or a close encounter with another galaxy in the cluster.« less

GASP. III. JO36: A Case of Multiple Environmental Effects at Play?

NASA Astrophysics Data System (ADS)

Fritz, Jacopo; Moretti, Alessia; Gullieuszik, Marco; Poggianti, Bianca; Bruzual, Gustavo; Vulcani, Benedetta; Nicastro, Fabrizio; Jaffé, Yara; Cervantes Sodi, Bernardo; Bettoni, Daniela; Biviano, Andrea; Fasano, Giovanni; Charlot, Stéphane; Bellhouse, Callum; Hau, George

2017-10-01

The so-called jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped from the main body of the galaxy. Several works have strongly suggested ram pressure stripping to be the mechanism driving this phenomenon. Here, we focus on one of these objects, drawn from a sample of optically selected jellyfish galaxies, and use it to validate sinopsis, the spectral fitting code that will be used for the analysis of the GASP (GAs Stripping Phenomena in galaxies with MUSE) survey, and study the spatial distribution and physical properties of the gas and stellar populations in this galaxy. We compare the model spectra to those obtained with gandalf, a code with similar features widely used to interpret the kinematics of stars and gas in galaxies from IFU data. We find that sinopsis can reproduce the pixel-by-pixel spectra of this galaxy at least as well as gandalf does, providing reliable estimates of the underlying stellar absorption to properly correct the nebular gas emission. Using these results, we find strong evidences of a double effect of ram pressure exerted by the intracluster medium onto the gas of the galaxy. A moderate burst of star formation, dating between 20 and 500 Myr ago and involving the outer parts of the galaxy more strongly than the inner regions, was likely induced by a first interaction of the galaxy with the intracluster medium. Stripping by ram pressure, plus probable gas depletion due to star formation, contributed to create a truncated ionized gas disk. The presence of an extended stellar tail on only one side of the disk points instead to another kind of process, likely gravitational interaction by a fly-by or a close encounter with another galaxy in the cluster.

Effects of curcumin consumption on human chronic diseases: A narrative review of the most recent clinical data.

PubMed

Mantzorou, Maria; Pavlidou, Eleni; Vasios, George; Tsagalioti, Eftychia; Giaginis, Constantinos

2018-06-01

Numerous clinical trials have investigated the potential beneficial effects of curcumin supplementation against several human chronic diseases. Up to now, it has been claimed that curcumin consumption may exert beneficial effects against several chronic diseases by promoting human health and preventing diseases. In this aspect, the present review aims to critically collect and in-depth summarize the most recent, well-designed clinical studies evaluating the potential beneficial effects of curcumin consumption on human health promotion and disease prevention. According to recent and well-designed clinical studies, curcumin consumption may benefit against obesity, metabolic syndrome, and diabetes. Moreover, curcumin consumption seems to exert a positive effect on people suffering from various types of cancer, fatty liver disease, depression, arthritis, skin diseases, gut inflammation, and symptoms of premenstrual syndrome. Due to the strong heterogeneity among the clinical studies concerning the exact effective curcumin dose and formulation, as well as the recommended treatment duration for each chronic disease, no precise and definitive conclusions could be drawn. Further large-scale prospective studies are strongly recommended, being well-designed as far as follow-up times, dosage, formulation, and duration of curcumin supplementation are concerned. Moreover, potential confounders in each specific chronic disease should carefully be taken into account in future studies. Copyright © 2018 John Wiley & Sons, Ltd.

Accretion and Propeller Torque in the Spin-Down Phase of Neutron Stars: The case of transitional millisecond pulsar PSR J1023+0038

NASA Astrophysics Data System (ADS)

Ertan, Ünal

2018-05-01

The spin-down rate of PSR J1023+0038, one of the three confirmed transitional millisecond pulsars, was measured in both radio pulsar (RMSP) and X-ray pulsar (LMXB) states. The spin-down rate in the LMXB state is only about 27% greater than in the RMSP state (Jaodand et al. 2016). The inner disk radius, rin, obtained recently by Ertan (2017) for the propeller phase, which is close to the co-rotation radius, rco, and insensitive to the mass-flow rate, can explain the observed torques together with the X-ray luminosities, Lx . The X-ray pulsar and radio pulsar states correspond to accretion with spin-down (weak propeller) and strong propeller situations respectively. Several times increase in the disk mass-flow rate takes the source from the strong propeller with a low Lx to the weak propeller with a higher Lx powered by accretion on to the star. The resultant decrease in rin increases the magnetic torque slightly, explaining the observed small increase in the spin-down rate. We have found that the spin-up torque exerted by accreting material is much smaller than the magnetic spin-down torque exerted by the disk in the LMXB state.

Chemically engineered sulfated glucans from rice bran exert strong antiviral activity at the stage of viral entry.

PubMed

Ray, Bimalendu; Hutterer, Corina; Bandyopadhyay, Shruti S; Ghosh, Kanika; Chatterjee, Udipta R; Ray, Sayani; Zeitträger, Isabel; Wagner, Sabrina; Marschall, Manfred

2013-12-27

Attachment and entry of many viruses are mediated by their affinity for polysaccharides present on the surface of target cells. In this paper, we demonstrate that sulfated glucans isolated from rice (Oryza sativa) can be utilized as experimental drugs exerting strong antiviral activity. In particular, oleum-DMF-based extraction is described as a procedure for the generation of chemically engineered glucans from commercially available rice bran. The one-step procedure has the potential to provide a spectrum of related glucans with varying molecular masses and modifications, including sulfation. The sulfated glucans P444, P445, and P446 possess increased antiviral activity compared to a previously described glucan (S1G). P444, P445, and P446 were highly active against human cytomegalovirus (HCMV), moderately active against other members of the family Herpesviridae, while not active against unrelated viruses. Specific experimentation with HCMV-infected cells provided evidence that antiviral activity was based on inhibition of viral entry and that inhibition occurred in the absence of drug-induced cytotoxicity. These findings underline the high potential of sulfated glucans for antiviral research and drug development. In addition, the procedure described for the efficient transformation of glucan hydroxy groups to sulfate groups may be similarly beneficial for the chemical alteration of other natural products.

Slug/SNAI2 regulates cell proliferation and invasiveness of metastatic prostate cancer cell lines.

PubMed

Emadi Baygi, Modjtaba; Soheili, Zahra-Soheila; Essmann, Frank; Deezagi, Abdolkhaleg; Engers, Rainer; Goering, Wolfgang; Schulz, Wolfgang A

2010-08-01

Many metastatic cancers recapitulate the epithelial-to-mesenchymal transition (EMT) resulting in enhanced cell motility and invasiveness. The EMT is regulated by several transcription factors, including the zinc finger protein SNAI2, also named Slug, which appears to exert additional functions during development and cancer progression. We have studied the function of SNAI2 in prostate cancer cells. Quantitative RT-PCR analysis showed strong SNAI2 expression particularly in the PC-3 and PC3-16 prostate carcinoma cell lines. Knockdown of SNAI2 by specific siRNA induced changes in EMT markers and inhibited invasion of both cell lines into a matrigel matrix. SNAI2 siRNA-treated cells did not tolerate detachment from the culture plates, likely at least in part due to downregulation of integrin alpha6beta4. SNAI2 knockdown disturbed the microtubular and actin cytoskeletons, especially severely in PC-3 cells, resulting in grossly enlarged, flattened, and sometimes multinuclear cells. Knockdown also decreased cell proliferation, with a prominent G0/G1 arrest in PC3-16. Together, our data imply that SNAI2 exerts strong effects on the cytoskeleton and adhesion of those prostate cancer cells that express it and is necessary for their proliferation and invasiveness.

Effect of Liquid Crystalline Systems Containing Antimicrobial Compounds on Infectious Skin Bacteria.

PubMed

Souza, Carla; Watanabe, Evandro; Aires, Carolina Patrícia; Lara, Marilisa Guimarães

2017-08-01

This study aimed (i) to prepare liquid crystalline systems (LCS) of glyceryl monooleate (GMO) and water containing antibacterial compounds and (ii) to evaluate their potential as drug delivery systems for topical treatment of bacterial infections. Therefore, LCS containing CPC (cetylpyridinium chloride) (LCS/CPC) and PHMB (poly(hexamethylene biguanide) hydrochloride) (LCS/PHMB) were prepared and the liquid crystalline phases were identified by polarizing light microscopy 24 h and 7 days after preparation. The in vitro drug release profile and in vitro antibacterial activity of the systems were assessed using the double layer agar diffusion method against Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, Escherichia coli, and Enterococcus faecalis. The interaction between GMO and the drugs was evaluated by a drug absorption study. Stable liquid crystalline systems containing CPC and PHMB were obtained. LCS/PHMB decreased the PHMB release rate and exerted strong antibacterial activity against all the investigated bacteria. In contrast, CPC interacted with GMO so strongly that it became attached to the system; the amount released was not sufficient to exert antibacterial activity. Therefore, the studied liquid crystalline systems were suitable to deliver PHMB, but not CPC. Accordingly, it was demonstrated that GMO interacts with each drug differently, which may interfere in the final efficiency of GMO/water LCS.

Understory herb layer exerts strong controls on soil microbial communities in subtropical plantations

NASA Astrophysics Data System (ADS)

Yin, Kai; Zhang, Lei; Chen, Dima; Tian, Yichen; Zhang, Feifei; Wen, Meiping; Yuan, Chao

2016-05-01

The patterns and drivers of soil microbial communities in forest plantations remain inadequate although they have been extensively studied in natural forest and grassland ecosystems. In this study, using data from 12 subtropical plantation sites, we found that the overstory tree biomass and tree cover increased with increasing plantation age. However, there was a decline in the aboveground biomass and species richness of the understory herbs as plantation age increased. Biomass of all microbial community groups (i.e. fungi, bacteria, arbuscular mycorrhizal fungi, and actinomycete) decreased with increasing plantation age; however, the biomass ratio of fungi to bacteria did not change with increasing plantation age. Variation in most microbial community groups was mainly explained by the understory herb (i.e. herb biomass and herb species richness) and overstory trees (i.e. tree biomass and tree cover), while soils (i.e. soil moisture, soil organic carbon, and soil pH) explained a relative low percentage of the variation. Our results demonstrate that the understory herb layer exerts strong controls on soil microbial community in subtropical plantations. These findings suggest that maintenance of plantation health may need to consider the management of understory herb in order to increase the potential of plantation ecosystems as fast-response carbon sinks.

Understory herb layer exerts strong controls on soil microbial communities in subtropical plantations

PubMed Central

Yin, Kai; Zhang, Lei; Chen, Dima; Tian, Yichen; Zhang, Feifei; Wen, Meiping; Yuan, Chao

2016-01-01

The patterns and drivers of soil microbial communities in forest plantations remain inadequate although they have been extensively studied in natural forest and grassland ecosystems. In this study, using data from 12 subtropical plantation sites, we found that the overstory tree biomass and tree cover increased with increasing plantation age. However, there was a decline in the aboveground biomass and species richness of the understory herbs as plantation age increased. Biomass of all microbial community groups (i.e. fungi, bacteria, arbuscular mycorrhizal fungi, and actinomycete) decreased with increasing plantation age; however, the biomass ratio of fungi to bacteria did not change with increasing plantation age. Variation in most microbial community groups was mainly explained by the understory herb (i.e. herb biomass and herb species richness) and overstory trees (i.e. tree biomass and tree cover), while soils (i.e. soil moisture, soil organic carbon, and soil pH) explained a relative low percentage of the variation. Our results demonstrate that the understory herb layer exerts strong controls on soil microbial community in subtropical plantations. These findings suggest that maintenance of plantation health may need to consider the management of understory herb in order to increase the potential of plantation ecosystems as fast-response carbon sinks. PMID:27243577

Understory herb layer exerts strong controls on soil microbial communities in subtropical plantations.

PubMed

Yin, Kai; Zhang, Lei; Chen, Dima; Tian, Yichen; Zhang, Feifei; Wen, Meiping; Yuan, Chao

2016-05-31

The patterns and drivers of soil microbial communities in forest plantations remain inadequate although they have been extensively studied in natural forest and grassland ecosystems. In this study, using data from 12 subtropical plantation sites, we found that the overstory tree biomass and tree cover increased with increasing plantation age. However, there was a decline in the aboveground biomass and species richness of the understory herbs as plantation age increased. Biomass of all microbial community groups (i.e. fungi, bacteria, arbuscular mycorrhizal fungi, and actinomycete) decreased with increasing plantation age; however, the biomass ratio of fungi to bacteria did not change with increasing plantation age. Variation in most microbial community groups was mainly explained by the understory herb (i.e. herb biomass and herb species richness) and overstory trees (i.e. tree biomass and tree cover), while soils (i.e. soil moisture, soil organic carbon, and soil pH) explained a relative low percentage of the variation. Our results demonstrate that the understory herb layer exerts strong controls on soil microbial community in subtropical plantations. These findings suggest that maintenance of plantation health may need to consider the management of understory herb in order to increase the potential of plantation ecosystems as fast-response carbon sinks.

Combined reduced forced expiratory volume in 1 second (FEV1) and peripheral artery disease in sedentary elders with functional limitations.

PubMed

Vaz Fragoso, Carlos A; Hsu, Fang-Chi; Brinkley, Tina; Church, Timothy; Liu, Christine K; Manini, Todd; Newman, Anne B; Stafford, Randall S; McDermott, Mary M; Gill, Thomas M

2014-09-01

Because they are potentially modifiable and may coexist, we evaluated the combined occurrence of a reduced forced expiratory volume in 1 second (FEV1) and peripheral artery disease (PAD), including its association with exertional symptoms, physical inactivity, and impaired mobility, in sedentary elders with functional limitations. Cross sectional. Lifestyle Interventions and Independence in Elder (LIFE) Study. A total of 1307 sedentary community-dwelling persons, mean age 78.9, with functional limitations (Short Physical Performance Battery [SPPB] <10). A reduced FEV1 was defined by a z-score less than -1.64 (

Music in the exercise domain: a review and synthesis (Part I)

PubMed Central

Karageorghis, Costas I.; Priest, David-Lee

2011-01-01

Since a 1997 review by Karageorghis and Terry, which highlighted the state of knowledge and methodological weaknesses, the number of studies investigating musical reactivity in relation to exercise has swelled considerably. In this two-part review paper, the development of conceptual approaches and mechanisms underlying the effects of music are explicated (Part I), followed by a critical review and synthesis of empirical work (spread over Parts I and II). Pre-task music has been shown to optimise arousal, facilitate task-relevant imagery and improve performance in simple motoric tasks. During repetitive, endurance-type activities, self-selected, motivational and stimulative music has been shown to enhance affect, reduce ratings of perceived exertion, improve energy efficiency and lead to increased work output. There is evidence to suggest that carefully selected music can promote ergogenic and psychological benefits during high-intensity exercise, although it appears to be ineffective in reducing perceptions of exertion beyond the anaerobic threshold. The effects of music appear to be at their most potent when it is used to accompany self-paced exercise or in externally valid conditions. When selected according to its motivational qualities, the positive impact of music on both psychological state and performance is magnified. Guidelines are provided for future research and exercise practitioners. PMID:22577472

Music in the exercise domain: a review and synthesis (Part II)

PubMed Central

Karageorghis, Costas I.; Priest, David-Lee

2011-01-01

Since a 1997 review by Karageorghis and Terry, which highlighted the state of knowledge and methodological weaknesses, the number of studies investigating musical reactivity in relation to exercise has swelled considerably. In this two-part review paper, the development of conceptual approaches and mechanisms underlying the effects of music are explicated (Part I), followed by a critical review and synthesis of empirical work (spread over Parts I and II). Pre-task music has been shown to optimise arousal, facilitate task-relevant imagery and improve performance in simple motoric tasks. During repetitive, endurance-type activities, self-selected, motivational and stimulative music has been shown to enhance affect, reduce ratings of perceived exertion, improve energy efficiency and lead to increased work output. There is evidence to suggest that carefully selected music can promote ergogenic and psychological benefits during high-intensity exercise, although it appears to be ineffective in reducing perceptions of exertion beyond the anaerobic threshold. The effects of music appear to be at their most potent when it is used to accompany self-paced exercise or in externally valid conditions. When selected according to its motivational qualities, the positive impact of music on both psychological state and performance is magnified. Guidelines are provided for future research and exercise practitioners. PMID:22577473

Monoamine Reuptake Inhibitors in Parkinson's Disease

PubMed Central

Huot, Philippe; Fox, Susan H.; Brotchie, Jonathan M.

2015-01-01

The motor manifestations of Parkinson's disease (PD) are secondary to a dopamine deficiency in the striatum. However, the degenerative process in PD is not limited to the dopaminergic system and also affects serotonergic and noradrenergic neurons. Because they can increase monoamine levels throughout the brain, monoamine reuptake inhibitors (MAUIs) represent potential therapeutic agents in PD. However, they are seldom used in clinical practice other than as antidepressants and wake-promoting agents. This review article summarises all of the available literature on use of 50 MAUIs in PD. The compounds are divided according to their relative potency for each of the monoamine transporters. Despite wide discrepancy in the methodology of the studies reviewed, the following conclusions can be drawn: (1) selective serotonin transporter (SERT), selective noradrenaline transporter (NET), and dual SERT/NET inhibitors are effective against PD depression; (2) selective dopamine transporter (DAT) and dual DAT/NET inhibitors exert an anti-Parkinsonian effect when administered as monotherapy but do not enhance the anti-Parkinsonian actions of L-3,4-dihydroxyphenylalanine (L-DOPA); (3) dual DAT/SERT inhibitors might enhance the anti-Parkinsonian actions of L-DOPA without worsening dyskinesia; (4) triple DAT/NET/SERT inhibitors might exert an anti-Parkinsonian action as monotherapy and might enhance the anti-Parkinsonian effects of L-DOPA, though at the expense of worsening dyskinesia. PMID:25810948

Amplexicaule A exerts anti-tumor effects by inducing apoptosis in human breast cancer

PubMed Central

Shu, Guangwen; Wan, Dingrong; He, Feng; Loaec, Morgann; Ding, Yali; Li, Jun; Dovat, Sinisa; Yang, Gaungzhong; Song, Chunhua

2016-01-01

Chemotherapy is the main treatment for patients with breast cancer metastases, but natural alternatives have been receiving attention for their potential as novel anti-tumor reagents. Amplexicaule A (APA) is a flavonoid glucoside isolated from rhizomes of Polygonum amplexicaule D. Don var. sinense Forb (PADF). We found that APA has anti-tumor effects in a breast cancer xenograft mouse model and induces apoptosis in breast cancer cell lines. APA increased levels of cleaved caspase-3,-8,-9 and PARP, which resulted from suppression of MCL-1 and BCL-2 expression in the cells. APA also inactivated the Akt/mTOR pathway in breast cancer cells. Thus, APA exerts a strong anti-tumor effect on breast cancer cells, most likely through induction of apoptosis. Our study is the first to identify this novel anti-tumor compound and provides a new strategy for isolation and separation of single compounds from herbs. PMID:26943775

In vitro activity of the beta-carboline alkaloids harmane, harmine, and harmaline toward parasites of the species Leishmania infantum.

PubMed

Di Giorgio, C; Delmas, F; Ollivier, E; Elias, R; Balansard, G; Timon-David, P

2004-01-01

Harmane, harmine, and harmaline were investigated for their in vitro antileishmanial activity toward parasites of the species Leishmania infantum. Harmane and Harmine displayed a moderate antiproliferative activity toward human monocytes and exerted a weak antileishmanial activity toward both the promastigote and the amastigote forms of the parasite. Their mechanism of action on the promastigote form of the parasite involved interactions with DNA metabolism leading to an accumulation of parasites in the S-G(2)M phases of the cell-cycle. Harmaline, at the contrary, was deprived from toxicity toward human cells and Leishmania promastigotes, however it exerted a strong antileishmanial activity toward the intracellular amastigote form of the parasite. This property was shown to partly result from the capacity of the molecule to prevent parasite internalization within macrophages by inhibiting Leishmania PKC activity.

Flavocoxid, a Nutraceutical Approach to Blunt Inflammatory Conditions

PubMed Central

Squadrito, Francesco; Mecchio, Anna

2014-01-01

Flavonoids, from Scutellaria baicalensis (Chinese skullcap) and Acacia catechu (black catechu), have been shown to exert a variety of therapeutic effects, including anti-inflammatory, antiviral, antibacterial, and anticancer activities. Flavocoxid is a mixed extract containing baicalin and catechin and it acts as a dual balanced inhibitor of cyclooxygenase-1 (COX-1) and COX-2 peroxidase enzyme activities with a significant inhibition of 5-lipoxygenase (5-LOX) enzyme activity in vitro. Flavocoxid downregulates gene or protein expression of several inflammatory markers and exerts also strong antioxidant activity in several experimental models. Controlled clinical trials and a postmarketing study have clearly shown that flavocoxid is as effective as naproxen in managing the signs and symptoms of osteoarthritis of the knee and it has better upper gastrointestinal, renal, and respiratory safety profile than naproxen. Flavocoxid may therefore provide a potential therapeutic approach to the treatment of chronic inflammatory conditions. PMID:25242871

Flavocoxid, a nutraceutical approach to blunt inflammatory conditions.

PubMed

Bitto, Alessandra; Squadrito, Francesco; Irrera, Natasha; Pizzino, Gabriele; Pallio, Giovanni; Mecchio, Anna; Galfo, Federica; Altavilla, Domenica

2014-01-01

Flavonoids, from Scutellaria baicalensis (Chinese skullcap) and Acacia catechu (black catechu), have been shown to exert a variety of therapeutic effects, including anti-inflammatory, antiviral, antibacterial, and anticancer activities. Flavocoxid is a mixed extract containing baicalin and catechin and it acts as a dual balanced inhibitor of cyclooxygenase-1 (COX-1) and COX-2 peroxidase enzyme activities with a significant inhibition of 5-lipoxygenase (5-LOX) enzyme activity in vitro. Flavocoxid downregulates gene or protein expression of several inflammatory markers and exerts also strong antioxidant activity in several experimental models. Controlled clinical trials and a postmarketing study have clearly shown that flavocoxid is as effective as naproxen in managing the signs and symptoms of osteoarthritis of the knee and it has better upper gastrointestinal, renal, and respiratory safety profile than naproxen. Flavocoxid may therefore provide a potential therapeutic approach to the treatment of chronic inflammatory conditions.

Blade size and weight effects in shovel design.

PubMed

Freivalds, A; Kim, Y J

1990-03-01

The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using five shovels with varying blade sizes and weights to move sand. Energy expenditure, normalised to subject weight and load handled, varied quadratically with the blade-size/shovel-weight (B/W) ratio. Minimum energy cost was at B/W = 0.0676 m2/kg, which for an average subject and average load would require an acceptable 5.16 kcal/min of energy expenditure. Subjects, through the ratings of perceived exertion, also strongly preferred the lighter shovels without regard to blade size. Too large a blade or too heavy a shovel increased energy expenditure beyond acceptable levels, while too small a blade reduced efficiency of the shovelling.

Adapting to an invasive species: toxic cane toads induce morphological change in Australian snakes.

PubMed

Phillips, Ben L; Shine, Richard

2004-12-07

The arrival of invasive species can devastate natural ecosystems, but the long-term effects of invasion are less clear. If native organisms can adapt to the presence of the invader, the severity of impact will decline with time. In Australia, invasive cane toads (Bufo marinus) are highly toxic to most snakes that attempt to eat them. Because snakes are gape-limited predators with strong negative allometry for head size, maximum relative prey mass (and thus, the probability of eating a toad large enough to be fatal) decreases with an increase in snake body size. Thus, the arrival of toads should exert selection on snake morphology, favoring an increase in mean body size and a decrease in relative head size. We tested these predictions with data from specimens of four species of Australian snakes, collected over >80 years. Geographic information system layers provided data on the duration of toad exposure for each snake population, as well as environmental variables (latitude, precipitation, and temperature). As predicted, two toad-vulnerable species (Pseudechis porphyriacus and Dendrelaphis punctulatus) showed a steady reduction in gape size and a steady increase in body length with time since exposure to toads. In contrast, two species at low risk from toads (Hemiaspis signata and Tropidonophis mairii) showed no consistent change in these morphological traits as a function of the duration of toad exposure. These results provide strong evidence of adaptive changes in native predators as a result of the invasion of toxic prey.

Effects of amyloid-β plaque proximity on the axon initial segment of pyramidal cells.

PubMed

León-Espinosa, Gonzalo; DeFelipe, Javier; Muñoz, Alberto

2012-01-01

The output of cortical pyramidal cells reflects the balance between excitatory inputs of cortical and subcortical origin, and inhibitory inputs from distinct populations of cortical GABAergic interneurons, each of which selectively innervate different domains of neuronal pyramidal cells (i.e., dendrites, soma and axon initial segment [AIS]). In Alzheimer's disease (AD), the presence of amyloid-β (Aβ) plaques alters the synaptic input to pyramidal cells in a number of ways. However, the effects of Aβ plaques on the AIS have still not been investigated to date. This neuronal domain is involved in input integration, as well as action potential initiation and propagation, and it exhibits Ca2+- and activity-dependent structural plasticity. The AIS is innervated by GABAergic axon terminals from chandelier cells, which are thought to exert a strong influence on pyramidal cell output. In the AβPP/PS1 transgenic mouse model of AD, we have investigated the effects of Aβ plaques on the morphological and neurochemical features of the AIS, including the cisternal organelle, using immunocytochemistry and confocal microscopy, as well as studying the innervation of the AIS by chandelier cell axon terminals. There is a strong reduction in GABAergic terminals that appose AIS membrane surfaces that are in contact with Aβ plaques, indicating altered inhibitory synapsis at the AIS. Thus, despite a lack of gross structural alterations in the AIS, this decrease in GABAergic innervation may deregulate AIS activity and contribute to the hyperactivity of neurons in contact with Aβ plaques.

Characterization of monoclonal antibodies that strongly inhibit Electrophorus electricus acetylcholinesterase.

PubMed

Remy, M H; Frobert, Y; Grassi, J

1995-08-01

In this study, we describe three different monoclonal antibodies (mAbs Elec-403, Elec-408, and Elec-410) directed against Electrophorus electricus acetylcholinesterase (AChE) which were selected as inhibitors for this enzyme. Two of these antibodies (Elec-403 and Elec-410), recognized overlapping but different epitopes, competed with snake venom toxin fasciculin for binding to the enzyme, and thus apparently recognized the peripheral site of AChE. In addition, the binding of Elec-403 was antagonized by 1,5-bis(4-allyldimethylammoniumphenyl)pentan-3-one dibromide (BW284C51) and propidium, indicating that the corresponding epitope encompassed the anionic site involved in the binding of these low-molecular-mass inhibitors. The third mAb (Elec-408), was clearly bound to another site on the AChE molecule, and its inhibitory effect was cumulative with those of Elec-403, Elec-410, and fasciculin. All mAbs bound AChE with high affinity and were as strong inhibitors with an apparent Ki values less than 0.1 nM. Elec-403 was particularly efficient with an inhibitory activity similar to that of fasciculin. Inhibition was observed with both charged (acetylthiocholine) and neutral substrates (o-nitrophenyl acetate) and had the characteristics of a non-competitive process. Elec-403 and Elec-410 probably exert their effect by triggering allosteric transitions from the peripheral site to the active site. The epitope recognized by mAb Elec-408 has not been localized, but it may correspond to a new regulatory site on AChE.

Volunteerism or Labor Exploitation? Harnessing the Volunteer Spirit to Sustain AIDS Treatment Programs in Urban Ethiopia

PubMed Central

Maes, Kenneth

2013-01-01

Based on ethnographic research in Addis Ababa, Ethiopia, this paper describes NGO efforts to encourage AIDS care volunteers to eschew material returns for their labor and instead reflect on the goodness of sacrificing to promote the survival of people living with HIV/AIDS. Consensus analysis of motivational survey data collected from a sample of AIDS care volunteers (n=110) suggests that they strongly share a sacrificial and prosocial motivational model. These results may be explained by several factors, including the efforts of the organizations to shape volunteers’ motivations, the self-selection of volunteers, positive reinforcement in seeing one’s patients become healthy, and social desirability bias. In-depth interviews examining the motivations and behaviors of volunteers reveal a more complicated picture: even ostensibly devoted and altruistic volunteers strongly question their service commitments. The complexity and ambivalence of volunteers’ motivations reflect the profound uncertainty that they face in achieving improved socioeconomic status for themselves and their families amid widespread unemployment and sharply rising food prices. Their desires for economic opportunities explain why local NGOs exert so much effort to shape and sustain—and yet fail to completely control—their motivations. This recasts economically-insecure volunteers’ consent to donate their labor as a process of negotiation with their organizers. Future research should explore how models of health care volunteerism and volunteer motivations are shaped by individual and collective experiences in political-economic context. PMID:24077802

Optical pulling and pushing forces exerted on silicon nanospheres with strong coherent interaction between electric and magnetic resonances.

PubMed

Liu, Hongfeng; Panmai, Mingcheng; Peng, Yuanyuan; Lan, Sheng

2017-05-29

We investigated theoretically and numerically the optical pulling and pushing forces acting on silicon (Si) nanospheres (NSs) with strong coherent interaction between electric and magnetic resonances. We examined the optical pulling and pushing forces exerted on Si NSs by two interfering waves and revealed the underlying physical mechanism from the viewpoint of electric- and magnetic-dipole manipulation. As compared with a polystyrene (PS) NS, it was found that the optical pulling force for a Si NS with the same size is enlarged by nearly two orders of magnitude. In addition to the optical pulling force appearing at the long-wavelength side of the magnetic dipole resonance, very large optical pushing force is observed at the magnetic quadrupole resonance. The correlation between the optical pulling/pushing force and the directional scattering characterized by the ratio of the forward to backward scattering was revealed. More interestingly, it was found that the high-order electric and magnetic resonances in large Si NSs play an important role in producing optical pulling force which can be generated by not only s-polarized wave but also p-polarized one. Our finding indicates that the strong coherent interaction between the electric and magnetic resonances existing in nanoparticles with large refractive indices can be exploited to manipulate the optical force acting on them and the correlation between the optical force and the directional scattering can be used as guidance. The engineering and manipulation of optical forces will find potential applications in the trapping, transport and sorting of nanoparticles.

Inducible antisense suppression of glycolate oxidase reveals its strong regulation over photosynthesis in rice.

PubMed

Xu, Huawei; Zhang, Jianjun; Zeng, Jiwu; Jiang, Linrong; Liu, Ee; Peng, Changlian; He, Zhenghui; Peng, Xinxiang

2009-01-01

Photorespiration is one of the most intensively studied topics in plant biology. While a number of mutants deficient in photorespiratory enzymes have been identified and characterized for their physiological functions, efforts on glycolate oxidase (GLO; EC 1.1.3.15) have not been so successful. This is a report about the generation of transgenic rice (Oryza sativa L.) plants carrying a GLO antisense gene driven by an estradiol-inducible promoter, which allowed for controllable suppressions of GLO and its detailed functional analyses. The GLO-suppressed plants showed typical photorespiration-deficient phenotypes. More intriguingly, it was found that a positive and linear correlation existed between GLO activities and the net photosynthetic rates (P(N)), and photoinhibition subsequently occurred once P(N) reduction surpassed 60%, indicating GLO can exert a strong regulation over photosynthesis. Various expression analyses identified that Rubisco activase was transcriptionally suppressed in the GLO-suppressed plants, consistent with the decreased Rubisco activation states. While the substrate glycolate accumulated substantially, few changes were observed for the product glyoxylate, and for some other downstream metabolites or genes as well in the transgenic plants. Further analyses revealed that isocitrate lyase and malate synthase, two key enzymes in the glyoxylate cycle, were highly up-regulated under GLO deficiency. Taken together, the results suggest that GLO is a typical photorespiratory enzyme and that it can exert a strong regulation over photosynthesis, possibly through a feed-back inhibition on Rubisco activase, and that the glyoxylate cycle may be partially activated to compensate for the photorespiratory glyoxylate when GLO is suppressed in rice.

Evolutionary games on cycles with strong selection

NASA Astrophysics Data System (ADS)

Altrock, P. M.; Traulsen, A.; Nowak, M. A.

2017-02-01

Evolutionary games on graphs describe how strategic interactions and population structure determine evolutionary success, quantified by the probability that a single mutant takes over a population. Graph structures, compared to the well-mixed case, can act as amplifiers or suppressors of selection by increasing or decreasing the fixation probability of a beneficial mutant. Properties of the associated mean fixation times can be more intricate, especially when selection is strong. The intuition is that fixation of a beneficial mutant happens fast in a dominance game, that fixation takes very long in a coexistence game, and that strong selection eliminates demographic noise. Here we show that these intuitions can be misleading in structured populations. We analyze mean fixation times on the cycle graph under strong frequency-dependent selection for two different microscopic evolutionary update rules (death-birth and birth-death). We establish exact analytical results for fixation times under strong selection and show that there are coexistence games in which fixation occurs in time polynomial in population size. Depending on the underlying game, we observe inherence of demographic noise even under strong selection if the process is driven by random death before selection for birth of an offspring (death-birth update). In contrast, if selection for an offspring occurs before random removal (birth-death update), then strong selection can remove demographic noise almost entirely.

Does antifouling paint select for antibiotic resistance?

PubMed

Flach, Carl-Fredrik; Pal, Chandan; Svensson, Carl Johan; Kristiansson, Erik; Östman, Marcus; Bengtsson-Palme, Johan; Tysklind, Mats; Larsson, D G Joakim

2017-07-15

There is concern that heavy metals and biocides contribute to the development of antibiotic resistance via co-selection. Most antifouling paints contain high amounts of such substances, which risks turning painted ship hulls into highly mobile refuges and breeding grounds for antibiotic-resistant bacteria. The objectives of this study were to start investigate if heavy-metal based antifouling paints can pose a risk for co-selection of antibiotic-resistant bacteria and, if so, identify the underlying genetic basis. Plastic panels with one side painted with copper and zinc-containing antifouling paint were submerged in a Swedish marina and biofilms from both sides of the panels were harvested after 2.5-4weeks. DNA was isolated from the biofilms and subjected to metagenomic sequencing. Biofilm bacteria were cultured on marine agar supplemented with tetracycline, gentamicin, copper sulfate or zinc sulfate. Biofilm communities from painted surfaces displayed lower taxonomic diversity and enrichment of Gammaproteobacteria. Bacteria from these communities showed increased resistance to both heavy metals and tetracycline but not to gentamicin. Significantly higher abundance of metal and biocide resistance genes was observed, whereas mobile antibiotic resistance genes were not enriched in these communities. In contrast, we found an enrichment of chromosomal RND efflux system genes, including such with documented ability to confer decreased susceptibility to both antibiotics and biocides/heavy metals. This was paralleled by increased abundances of integron-associated integrase and ISCR transposase genes. The results show that the heavy metal-based antifouling paint exerts a strong selection pressure on marine bacterial communities and can co-select for certain antibiotic-resistant bacteria, likely by favoring species and strains carrying genes that provide cross-resistance. Although this does not indicate an immediate risk for promotion of mobile antibiotic resistance, the clear increase of genes involved in mobilizing DNA provides a foundation for increased opportunities for gene transfer in such communities, which might also involve yet unknown resistance mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Age, Country, and Gender on Music Listening Preferences.

ERIC Educational Resources Information Center

LeBlanc, Albert; Jin, Young Chang; Stamou, Lelouda; McCrary, Jan

1999-01-01

Examines the music listening preferences of 2,042 students from Greece, South Korea, and the United States using a survey that listed selections from art music, traditional jazz, and rock music. Finds that age, gender, and country all exerted influence, but the variables did not perform the same way in each country. (CMK)

Dynamics of Attentional Selection under Conflict: Toward a Rational Bayesian Account

ERIC Educational Resources Information Center

Yu, Angela J.; Dayan, Peter; Cohen, Jonathan D.

2009-01-01

The brain exhibits remarkable facility in exerting attentional control in most circumstances, but it also suffers apparent limitations in others. The authors' goal is to construct a rational account for why attentional control appears suboptimal under conditions of conflict and what this implies about the underlying computational principles. The…

Using Wikis in Academic Libraries

ERIC Educational Resources Information Center

Kai-Wah Chu, Samuel

2009-01-01

This is an exploratory study investigating the use of wikis in academic libraries. Reasons for using and not using wikis, level of control exerted on wikis users and perceived benefits and costs of using wikis are the major areas examined. Sixty universities were selected to complete either survey 1 or survey 2, depending on their usage of wikis…

Authority Base, Denomination, Moral Philosophy and the Power Strategies Used by Clergymen.

ERIC Educational Resources Information Center

Falbo, Toni; And Others

Clergymen are regarded by their congregations as having the authority to influence church members and clergymen are expected to exert influence. Three types of clerical authority have been identified: charismatic, traditional, and legal-rational. The common assumption that people select power strategies that are consistent with their perceptions…

The Effects of Illustrations on the Reading Performance of Learning Disabled and Normal Children.

ERIC Educational Resources Information Center

Harber, Jean R.

1983-01-01

Complete and partial illustrations were found to exert a detrimental effect on the reading performance of 52 learning disabled students (grades two to four) but a beneficial effect on the performance of 24 normally achieving second graders. Findings provided indirect support for the selective attention hypothesis. (Author/CL)

Trehalose and Magnesium Chloride Exert a Common Anti-amyloidogenic Effect Towards Hen Egg White Lysozyme.

PubMed

Chatterjee, Rupsa; Kolli, Vidyalatha; Sarkar, Nandini

2017-04-01

Many degenerative disorder such as Parkinsons, Alzheimers, Huntingtons disease, etc are caused due to the deposition of amyloid fibrils, formed due to the ordered aggregation of misfolded/unfolded proteins. Misfolded or unfolded proteins aggregate mostly through hydrophobic interactions which are unexposed in native state, but become exposed upon unfolding. To counteract amyloid related diseases, inhibition of the protein self assembly into fibril is a potential therapeutic strategy. The study aims at investigating the effect of selected compounds, namely trehalose and magnesium chloride hexahydrate towards inhibition and disaggregation of amyloid fibrils using Hen Egg White Lysozyme as a model. We further attempted to understand the mechanism of action with the help of various biophysical, microscopic as well as computational studies. A common mechanism of action was identified where the selected compounds exert their anti-amyloidogenic effects by altering HEWL conformations characterized by reduction in the beta sheet content and decrease in exposed hydrophobic surfaces. The altered conformation seems to have lesser amyloidogenic propensity leading to inhibition as well as disaggregation of amyloids.

Effect of Sacroiliac Joint Manipulation on Selected Gait Parameters in Healthy Subjects.

PubMed

Wójtowicz, Sebastian; Sajko, Igor; Hadamus, Anna; Mosiołek, Anna; Białoszewski, Dariusz

2017-08-31

The sacroiliac joints have complicated biomechanics. While the movements in the joints are small, they exert a significant effect on gait. This study aimed to assess how sacroiliac joint manipulation influences selected gait parameters. The study enrolled 57 healthy subjects. The experimental group consisted of 26 participants diagnosed with dysfunction of one sacroiliac joint. The control group was composed of 31 persons. All subjects from the experimental group underwent sacroiliac joint manipulation. The experimental group showed significant lengthening of the step on both sides and the stride length in this group increased as well. Moreover, the duration of the stride increased (p=0.000826). The maximum midfoot pressure was higher and maximum heel pressure decreased. The differences were statistically significant. 1. Subclinical dysfunctions of the sacroiliac joints may cause functional gait disturbance. 2. Manipulation of the iliosacral joint exerts a significant effect on gait parameters, which may lead to improved gait economy and effec-tiveness. 3. Following manipulation of one iliosacral joint, altered gait parameters are noted on both the manipulated side and the contralateral side, which may translate into improved quality of locomotion.

Press/Pulse: Explaining selective terrestrial extinctions at the Cretaceous/Palaeogene boundary

NASA Astrophysics Data System (ADS)

Arens, Nan Crystal

2010-05-01

Single-cause mass extinction scenarios require extreme conditions to generate sufficiently strong kill mechanisms. Such dire effects are commonly at odds with the taxonomic selectivity that characterizes most extinction events. In response, some researchers have proposed that the interaction of a variety of factors typify episodes of elevated extinction. Previous work (Arens & West 2008 Paleobiology 34:456-471) has shown that a combination of press and pulse disturbances increases the probability of elevated extinction. The press/pulse contrast is borrowed from community ecology, where researchers have long recognized that the ecological response to long-term stress differs from that of an instantaneous catastrophe. Scaled to the macroevolutionary level, press disturbances alter community composition by placing multigenerational stress on populations. Press disturbances do not necessarily cause mortality, but reduce population size by a variety of mechanisms such as curtailed reproduction. Pulse disturbances are sudden catastrophic events that cause extensive mortality. Either press or pulse disturbances of sufficient magnitude can cause extinction, however elevated extinction occurs more commonly during the coincidence of lower-magnitude press and pulse events. The Cretaceous/Palaeogene (K/P) extinction is one of the best examples of a press/pulse extinction. Deccan Trap volcanism, which straddled the K/P boundary, altered atmospheric composition and climate. This episodic volcanism likely contributed to the climate instability observed in terrestrial ecosystems and exerted press stress. Pulse disturbance was produced by bolide impact, which punctuated the end of the Cretaceous. The press/pulse mechanism also more effectively explains selectivity in terrestrial vertebrate and plant extinctions at the K/P boundary than do single-mechanisms scenarios. For example, why do environmentally sensitive vertebrates such as amphibians experience no extinction? And why do mire plants preferentially survive? Deccan Trap volcanism generated climatic warming and instability during the last 500 Ka of the Cretaceous. This resulted in extensive rearrangement of terrestrial floras. Dramatic cooling in the millennia immediately preceding the K/P boundary caused regional diversity loss and an apparent increase in vegetation heterogeneity. These changes, coupled with the spread of wetland ecosystems across the western interior of North America in the latest Cretaceous, exerted stress—press disturbance—on some elements of the biota, while favoring others. This press stress may have rendered lineages requiring well-drained or large homogeneous habitats endangered and vulnerable to extinction in the face of the terminal-Cretaceous bolide impact(s)—pulse disturbance. And, in fact, the impact's survivors were primarily wetland plants and animals.

Glucocorticoid-induced tethered transrepression requires SUMOylation of GR and formation of a SUMO-SMRT/NCoR1-HDAC3 repressing complex

PubMed Central

Hua, Guoqiang; Ganti, Krishna Priya; Chambon, Pierre

2016-01-01

Upon binding of a glucocorticoid (GC), the GC receptor (GR) can exert one of three transcriptional regulatory functions. We recently reported that SUMOylation of the GR at position K293 in humans (K310 in mice) within the N-terminal domain is indispensable for GC-induced evolutionary conserved inverted repeated negative GC response element (IR nGRE)-mediated direct transrepression. We now demonstrate that the integrity of this GR SUMOylation site is mandatory for the formation of a GR-small ubiquitin-related modifiers (SUMOs)-SMRT/NCoR1-HDAC3 repressing complex, which is indispensable for NF-κB/AP1-mediated GC-induced tethered indirect transrepression in vitro. Using GR K310R mutant mice or mice containing the N-terminal truncated GR isoform GRα-D3 lacking the K310 SUMOylation site, revealed a more severe skin inflammation than in WT mice. Importantly, cotreatment with dexamethasone (Dex) could not efficiently suppress a 12-O-tetradecanoylphorbol-13-acetate (TPA)–induced skin inflammation in these mutant mice, whereas it was clearly decreased in WT mice. In addition, in mice selectively ablated in skin keratinocytes for either nuclear receptor corepressor 1 (NCoR1)/silencing mediator for retinoid or thyroid-hormone receptors (SMRT) corepressors or histone deacetylase 3 (HDAC3), Dex-induced tethered transrepression and the formation of a repressing complex on DNA-bound NF-κB/AP1 were impaired. We previously suggested that GR ligands that would lack both (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression activities of GCs may preferentially exert the therapeutically beneficial GC antiinflammatory properties. Interestingly, we now identified a nonsteroidal antiinflammatory selective GR agonist (SEGRA) that selectively lacks both Dex-induced (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression functions, while still exerting a tethered indirect transrepression activity and could therefore be clinically lesser debilitating on long-term GC therapy. PMID:26712006

Mineral Control of Soil Carbon Dynamics in Forest Soils: A Lithosequence Under Ponderosa Pine

NASA Astrophysics Data System (ADS)

Heckman, K. A.; Welty-Bernard, A.; Rasmussen, C.; Schwartz, E.; Chorover, J.

2008-12-01

The role of soil organic carbon in regulating atmospheric CO2 concentration has spurred interest in both quantifying existing soil C stocks and modeling the behavior of soil C under climate change scenarios. Soil parent material exerts direct control over soil organic carbon content through its influence on soil pH and mineral composition. Soil acidity and mineral composition also influence soil microbial community composition and activity, thereby controlling soil respiration rates and microbial biomass size. We sampled a lithosequence of four parent materials (rhyolite, granite, basalt, limestone) under Pinus ponderosa to examine the effects of soil mineralogy and acidity on soil organic carbon content and soil microbial community. Three soil profiles were examined on each parent material and analyzed by X-ray diffraction, pH, selective dissolution, C and N content, and 13C signature. Soils from each of the four parent materials were incubated for 40 days, and microbial communities were compared on the basis of community composition (as determined through T-RFLP analysis), specific metabolic activity, biomass, δ13C of respired CO2, and cumulative amount of C mineralized over the course of the incubation. Soil C content varied significantly among soils of different parent material, and was strongly and positively associated with the abundance of Al-humus complexes r2 = 0.71; P < 0.0001, Fe-humus complexes r2 = 0.74; P = 0.0003, and crystalline Fe-oxide content r2 = 0.63; P = 0.0023. Microbial community composition varied significantly among soils and showed strong associations with soil pH 1:1 in KCl; r2 = 0.87; P < 0.0001, concentration of exchangeable Al r2 = 0.81; P < 0.0001, amorphous Fe oxide content r2 = 0.59; P < 0.004, and Al-humus content r2 = 0.35; P < 0.04. Mineralization rates, biomass and δ13C of respired CO2 differed among parent materials, and also varied with incubation time as substrate quality and N availability changed. The results demonstrate that within a specific ecosystem type, soil parent material exerts significant control over the lability and bioavailability of soil C and soil microbial community composition. We suggest that soil parent material and mineralogy are critical parameters for predicting soil C dynamics and recalcitrance of soil C stocks.

Micro-Valences: Perceiving Affective Valence in Everyday Objects

PubMed Central

Lebrecht, Sophie; Bar, Moshe; Barrett, Lisa Feldman; Tarr, Michael J.

2012-01-01

Perceiving the affective valence of objects influences how we think about and react to the world around us. Conversely, the speed and quality with which we visually recognize objects in a visual scene can vary dramatically depending on that scene’s affective content. Although typical visual scenes contain mostly “everyday” objects, the affect perception in visual objects has been studied using somewhat atypical stimuli with strong affective valences (e.g., guns or roses). Here we explore whether affective valence must be strong or overt to exert an effect on our visual perception. We conclude that everyday objects carry subtle affective valences – “micro-valences” – which are intrinsic to their perceptual representation. PMID:22529828

Ectoderm exerts the driving force for gastrulation in the sand dollar Scaphechinus mirabilis.

PubMed

Takata, H; Kominami, T

2001-06-01

How the ectodermal layer relates to the invagination processes was examined in the sand dollar Scaphechinus mirabilis. When the turgor pressure of blastocoele was increased, invagination was completely blocked. In contrast, an increase in turgor pressure did not affect elongation of the gut rudiment in the regular echinoid Hemicentrotus pulcherrimus. Rhodamine-phalloidin staining showed that the distribution of actin filaments was different between two species of embryos. In S. mirabilis gastrulating embryos, abundant actin filaments were seen at the basal cortex of ectoderm in addition to archenteron cells, while the intense signal was restricted to the archenteron in H. pulcherrimus. To investigate whether actin filaments contained in the ectodermal layer exert the force of invagination, a small part of the ectodermal layer was aspirated with a micropipette. If S. mirabilis embryos were aspirated from the onset of gastrulation, invagination did not occur at all, irrespective of the suction site. Even after the archenteron had invaginated to one-half of its full length, further elongation of the archenteron was severely blocked by suction of the lateral ectoderm. In contrast, suction of the ectodermal layer did not affect the elongation processes in H. pulcherrimus. These results strongly suggest that the ectodermal layer, especially in the vegetal half, exerts the driving force of invagination in S. mirabilis.

Medical barriers to emergency contraception: a cross-sectional survey of doctors in North India.

PubMed

Khan, M E; Dixit, Anvita; Bhatnagar, Isha; Brady, Martha

2014-05-01

Some medical doctors in India have publicly expressed opposition to making emergency contraceptive pills (ECPs) easily accessible, even though ECPs are included in the method mix of the Ministry of Health and Family Welfare program and as an over-the-counter (OTC) product. Such opposition affects access to ECPs by influencing policy, procurement, and distribution, besides stigmatizing the ECP user. This study was conducted to assess ECP knowledge, attitudes, and practices of doctors in North India. A cross-sectional survey of 83 doctors who provide ECPs, randomly selected from 3 cities in the state of Uttar Pradesh, was conducted in 2011. The quantitative data were complemented by 19 in-depth interviews with purposively selected senior gynecologists and other opinion leaders. All surveyed physicians cited the correct dose and regimen for ECPs. However, the large majority of those surveyed believed that ECPs work by preventing implantation. (The best evidence currently indicates that ECPs do not work by preventing implantation.) Most doctors also believed incorrectly that ECPs have several contraindications and side effects. They also had strong reservations against OTC provision of ECPs by pharmacists and community health workers (CHWs) and negative attitudes toward ECP users, which serve as serious medical barriers to mainstreaming use of ECPs. Physicians and their professional associations exert a strong influence on the operationalization of national contraceptive policies. Evidence-based advocacy and educational campaigns targeting doctors are needed to address and resolve their reservations about ECPs, particularly about its provision as an OTC product and its distribution by CHWs. Partnerships with medical associations can help reduce doctors' negative attitudes and create a conducive environment for influencing clinical practices. Such changes are needed to increase the availability and use of ECPs as part of a package of a full range of contraceptive method options to prevent unwanted pregnancy among the most vulnerable populations.

Security Assistance to Central America: Assessment of U.S. Involvement in El Salvador, Guatemala, and Honduras.

DTIC Science & Technology

1986-09-01

Latin America, including such powers as Mexico, Brazil , and Venezuala (17:4-6). 4. Foreign Military Sales (FMS) and Foreign Military Construction Sales...coastline where it is characterized by swamps and mangrove thickets. Like its counterpart in Nicaragua, the Honduran Mosquitia and adjoining portion of the... Brazil , Columbia, Argentina, and Chile. Other Central American countries have never been strong enough to exert any real influence, although

Assessment of Subjective Perceived Exertion at the Anaerobic Threshold with the Borg CR-10 Scale.

PubMed

Zamunér, Antonio R; Moreno, Marlene A; Camargo, Taís M; Graetz, Juliana P; Rebelo, Ana C S; Tamburús, Nayara Y; da Silva, Ester

2011-01-01

The purpose of this study was to evaluate the anaerobic threshold (AT) with a graphic visual method for estimating the intensity of ventilatory and metabolic exertion and to determine the ratings of perceived exertion (RPE) on the Borg CR-10 scale during a continuous ramp type exercise test (CT-R). Forty healthy, physically active and sedentary young women (age 23.1 ± 3.52 years) were divided into two groups according to their fitness level: active group (AG) and sedentary group (SG) and were submitted to a CT-R on a cycloergometer with 20 to 25 W/min increments. Shortly before the end of each one-minute period, the subjects were asked to rate dyspnea (RPE-D) and leg fatigue (RPE-L) on the Borg CR-10 scale. After the AT was determined with the graphic visual method, the score that the volunteers gave on the Borg CR10 scale was verified. Data were analyzed using the Mann-Whitney and Spearman correlation tests with the significance level set at 5%. The mean ratings of RPE-L and RPE-D at the AT level were not significantly different between groups (p > 0.05). Significant correlations were found between VO2, heart rate (HR), power output and RPE for both groups. The muscular and respiratory RPE, according to the Borg CR-10 scale, were correlated with the AT, suggesting that scores close to 5, which correspond to a "strong" perception, may be used as parameters for quantifying aerobic exercise intensity for active and sedentary individuals. The similar perception of exercise intensity, which corresponded to the AT of different individuals, makes it possible to prescribe exercise at an intensity equivalent to the AT by means of the RPE. Key pointsInterest in quantitative and systematic determination of the AT is growing, however, qualitative studies measure the AT by perceived exertion, are still unsubstantial.Borg CR-10 scale is a category scale with ratio properties consisting of numbers related to verbal expressions, which allows rate comparison between intensities as well as a determination of intensity levels.Scores close to 5 expressed on the Borg CR-10 scale, which correspond to a "strong" perception, may be used as parameters for quantifying the aerobic exercise intensity of both active and sedentary women.

N-ω-chloroacetyl-L-ornithine has in-vitro activity against cancer cell lines and in-vivo activity against ascitic and solid tumors.

PubMed

Vargas-Ramírez, Alba L; Medina-Enríquez, Miriam M; Cordero-Rodríguez, Neira I; Ruiz-Cuello, Tatiana; Aguilar-Faisal, Leopoldo; Trujillo-Ferrara, José G; Alcántara-Farfán, Verónica; Rodríguez-Páez, Lorena

2016-07-01

N-ω-chloroacetyl-L-ornithine (NCAO) is an ornithine decarboxylase (ODC) inhibitor that is known to exert cytotoxic and antiproliferative effects on three neoplastic human cancer cell lines (HeLa, MCF-7, and HepG2). Here, we show that NCAO has antiproliferative activity in 13 cancer cell lines, of diverse tissue origin from human and mice, and in a mouse cancer model in vivo. All cell lines were sensitive to NCAO after 72 h of treatment (the EC50 ranged from 1 to 50.6 µmol/l). The Ca Ski cell line was the most sensitive (EC50=1.18±0.07 µmol/l) and MDA-MB-231 was the least sensitive (EC50=50.6±0.3 µmol/l). This ODC inhibitor showed selectivity for cancer cells, exerting almost no cytotoxic effect on the normal Vero cell line (EC50>1000 µmol/l). NCAO induced apoptosis and inhibited tumor cell migration in vitro. Furthermore, in vivo, this compound (at 50 and 100 mg/kg, daily intraperitoneal injection for 7 days) exerted potent antitumor activity against both solid and ascitic tumors in a mouse model using the myeloma (Ag8) cell line. At these same two doses, the toxicological evaluation showed that NCAO has no obvious systemic toxicity. The current results suggest that the antitumor activity is exerted by apoptosis related not only to a local but also a systemic cytotoxic effect exerted by NCAO on tumor cells. The applications for NCAO as an antitumor agent may be extensive; however, further studies are needed to ascertain the antitumor activity on other types of tumor in vivo and to determine the precise molecular mechanism of its activity.

Dopamine D2/D3 but not dopamine D1 receptors are involved in the rapid antidepressant-like effects of ketamine in the forced swim test.

PubMed

Li, Yan; Zhu, Zhuo R; Ou, Bao C; Wang, Ya Q; Tan, Zhou B; Deng, Chang M; Gao, Yi Y; Tang, Ming; So, Ji H; Mu, Yang L; Zhang, Lan Q

2015-02-15

Major depressive disorder is one of the most prevalent and life-threatening forms of mental illnesses. The traditional antidepressants often take several weeks, even months, to obtain clinical effects. However, recent clinical studies have shown that ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, exerts rapid antidepressant effects within 2h and are long-lasting. The aim of the present study was to investigate whether dopaminergic system was involved in the rapid antidepressant effects of ketamine. The acute administration of ketamine (20 mg/kg) significantly reduced the immobility time in the forced swim test. MK-801 (0.1 mg/kg), the more selective NMDA antagonist, also exerted rapid antidepressant-like effects. In contrast, fluoxetine (10 mg/kg) did not significantly reduced the immobility time in the forced swim test after 30 min administration. Notably, pretreatment with haloperidol (0.15 mg/kg, a nonselective dopamine D2/D3 antagonist), but not SCH23390 (0.04 and 0.1 mg/kg, a selective dopamine D1 receptor antagonist), significantly prevented the effects of ketamine or MK-801. Moreover, the administration of sub-effective dose of ketamine (10 mg/kg) in combination with pramipexole (0.3 mg/kg, a dopamine D2/D3 receptor agonist) exerted antidepressant-like effects compared with each drug alone. In conclusion, our results indicated that the dopamine D2/D3 receptors, but not D1 receptors, are involved in the rapid antidepressant-like effects of ketamine. Copyright © 2014 Elsevier B.V. All rights reserved.

Altered trait variability in response to size-selective mortality.

PubMed

Uusi-Heikkilä, Silva; Lindström, Kai; Parre, Noora; Arlinghaus, Robert; Alós, Josep; Kuparinen, Anna

2016-09-01

Changes in trait variability owing to size-selective harvesting have received little attention in comparison with changes in mean trait values, perhaps because of the expectation that phenotypic variability should generally be eroded by directional selection typical for fishing and hunting. We show, however, that directional selection, in particular for large body size, leads to increased body-size variation in experimentally harvested zebrafish (Danio rerio) populations exposed to two alternative feeding environments: ad libitum and temporarily restricted food availability. Trait variation may influence population adaptivity, stability and resilience. Therefore, rather than exerting selection pressures that favour small individuals, our results stress the importance of protecting large ones, as they can harbour a great amount of variation within a population, to manage fish stocks sustainably. © 2016 The Author(s).

Varieties of Stimulus Control in Matching-to-Sample: A Kernel Analysis

ERIC Educational Resources Information Center

Fields, Lanny; Garruto, Michelle; Watanabe, Mari

2010-01-01

Conditional discrimination or matching-to-sample procedures have been used to study a wide range of complex psychological phenomena with infrahuman and human subjects. In most studies, the percentage of trials in which a subject selects the comparison stimulus that is related to the sample stimulus is used to index the control exerted by the…

Isolating causal pathways between flow and fish in the regulated river hierarchy

Treesearch

Ryan McManamay; Donald J. Orth; Charles A. Dolloff; David C. Mathews

2015-01-01

Unregulated river systems are organized in a hierarchy in which large scale factors (i.e. landscape and segment scales) influence local habitats (i.e. reach, meso- and microhabitat scales), and both differentially exert selective pressures on biota. Dams, however, create discontinua in these processes and change the hierarchical structure. We examined the relative...

Can elevated CO2 and ozone shift the genetic composition of aspen (Populus tremuloides) stands? New Phytologist

Treesearch

Emily V. Moran; Mark E. Kubiske

2013-01-01

The world's forests are currently exposed to increasing concentrations of carbon dioxide (CO2) and ozone (O3). Both pollutants can potentially exert a selective effect on plant populations. This, in turn, may lead to changes in ecosystem properties, such as carbon sequestration. Here, we report how elevated CO

Chronic Kidney Disease and Risk of Presenting with Acute Myocardial Infarction versus Stable Exertional Angina in Adults with Coronary Heart Disease

PubMed Central

Go, Alan S.; Bansal, Nisha; Chandra, Malini; Lathon, Phenius V.; Fortmann, Stephen P.; Iribarren, Carlos; Hsu, Chi-yuan; Hlatky, Mark A.

2011-01-01

Objective To examine whether kidney dysfunction is associated with the type of clinical presentation of coronary heart disease (CHD). Background Reduced kidney function increases risk of developing CHD, but it is not known whether it also influences the acuity of clinical presentation, which has important prognostic implications. Methods We conducted a case-control study of subjects whose first clinical presentation of CHD was either acute myocardial infarction or stable exertional angina between October 2001-December 2003. Glomerular filtration rate (eGFR) before the incident event was estimated using calibrated serum creatinine and the abbreviated MDRD equation. Patient characteristics and use of medications were ascertained from self-report and health plan databases. We used multivariable logistic regression to examine the association of reduced eGFR and CHD presentation. Results We studied 803 adults with incident acute myocardial infarction and 419 adults with incident stable exertional angina who had a baseline eGFR ≤130 ml/min/1.73 m2. Mean eGFR was lower among subjects with acute myocardial infarction compared with stable angina. Compared with eGFR 90–130 ml/min/1.73 m2, we found a strong, graded independent association between reduced eGFR and presenting with acute myocardial infarction: adjusted odds ratio (OR) 1.36 (95% CI: 0.99 to 1.86) for eGFR 60–89 ml/min/1.73 m2, OR 1.55 (0.92 to 2.62) for eGFR 45–59 ml/min/1.73 m2 and OR 3.82 (1.55 to 9.46) for eGFR <45 ml/min/1.73 m2 (P<0.001 for trend). Conclusion eGFR less than 45 ml/min/1.73 m2 is a strong, independent predictor of presenting with acute myocardial infarction versus stable angina as the initial manifestation of CHD. PMID:21958887

Punishment as a means of competition: implications for strong reciprocity theory.

PubMed

Paál, Tünde; Bereczkei, Tamás

2015-01-01

Strong negative reciprocity, that is, sanctions imposed on norm violators at the punisher's own expense, has powerful cooperation-enhancing effects in both real-life and experimental game situations. However, it is plausible that punishment may obtain alternative roles depending on social context and the personality characteristics of participants. We examined the occurrence of punishing behavior among 80 subjects in a strongly competitive Public Goods game setting. Despite the punishment condition, the amount of the contributions decreased steadily during the game. The amount of contributions had no significant effect on received and imposed punishments. The results indicate that certain social contexts (in this case, intensive competition) exert modifying effects on the role that punishment takes on. Subjects punished each other in order to achieve a higher rank and a financially better outcome. Punishment primarily functioned as a means of rivalry, instead of as a way of second-order cooperation, as strong reciprocity suggests. These results indicate the need for the possible modification of the social conditions of punishment mechanisms described by the strong reciprocity theory as an evolutionary explanation of human cooperation.

Punishment as a Means of Competition: Implications for Strong Reciprocity Theory

PubMed Central

Paál, Tünde; Bereczkei, Tamás

2015-01-01

Strong negative reciprocity, that is, sanctions imposed on norm violators at the punisher’s own expense, has powerful cooperation-enhancing effects in both real-life and experimental game situations. However, it is plausible that punishment may obtain alternative roles depending on social context and the personality characteristics of participants. We examined the occurrence of punishing behavior among 80 subjects in a strongly competitive Public Goods game setting. Despite the punishment condition, the amount of the contributions decreased steadily during the game. The amount of contributions had no significant effect on received and imposed punishments. The results indicate that certain social contexts (in this case, intensive competition) exert modifying effects on the role that punishment takes on. Subjects punished each other in order to achieve a higher rank and a financially better outcome. Punishment primarily functioned as a means of rivalry, instead of as a way of second-order cooperation, as strong reciprocity suggests. These results indicate the need for the possible modification of the social conditions of punishment mechanisms described by the strong reciprocity theory as an evolutionary explanation of human cooperation. PMID:25811464

Effect of sugar beet genotype on the Beet necrotic yellow vein virus P25 pathogenicity factor and evidence for a fitness penalty in resistance-breaking strains.

PubMed

Bornemann, Kathrin; Varrelmann, Mark

2013-05-01

Beet necrotic yellow vein virus (BNYVV), vectored by Polymyxa betae, causes rhizomania in sugar beet. For disease control, the cultivation of hybrids carrying Rz1 resistance is crucial, but is compromised by resistance-breaking (RB) strains with specific mutations in the P25 protein at amino acids 67-70 (tetrad). To obtain evidence for P25 variability from soil-borne populations, where the virus persists for decades, populations with wild-type (WT) and RB properties were analysed by P25 deep sequencing. The level of P25 variation in the populations analysed did not correlate with RB properties. Remarkably, one WT population contained P25 with RB mutations at a frequency of 11%. To demonstrate selection by Rz1 and the influence of RB mutations on relative fitness, competition experiments between strains were performed. Following a mixture of strains with four RNAs, a shift in tetrad variants was observed, suggesting that strains did not mix or transreplicate. The plant genotype exerted a clear influence on the frequency of RB tetrads. In Rz1 plants, the RB variants outcompeted the WT variants, and mostly vice versa in susceptible plants, demonstrating a relative fitness penalty of RB mutations. The strong genotype effect supports the hypothesized Rz1 RB strain selection with four RNAs, suggesting that a certain tetrad needs to become dominant in a population to influence its properties. Tetrad selection was not observed when an RB strain, with an additional P26 protein encoded by a fifth RNA, competed with a WT strain, supporting its role as a second BNYVV pathogenicity factor and suggesting the reassortment of both types. © 2013 BSPP AND BLACKWELL PUBLISHING LTD.

Asymmetric gene introgression in two closely related Orchis species: evidence from morphometric and genetic analyses

PubMed Central

2012-01-01

Background In food-deceptive orchids of the genera Anacamptis, Neotinea and Orchis floral isolation has been shown to be weak, whereas late-acting reproductive barriers are mostly strong, often restricting hybridization to the F1 generation. Only in a few species hybridization extends beyond the F1 generation, giving rise to hybrid swarms. However, little is known about the abundance of later-generation hybrids and what factors drive their occurrence in hybrid populations. In this study, molecular analyses were combined with detailed morphological measurements in a hybrid population of two closely related Orchis species (Orchis militaris and O. purpurea) to investigate the hypothesis that the abundance of later-generation hybrids is driven by changes in floral characters after hybridization that exert selective pressures that in turn affect hybridization. Results Both the molecular and morphological data point to extensive genetic and morphological homogenization and asymmetric introgression. Estimating genomic clines from the multi-locus genotype data and testing for deviation from neutrality revealed that 30 out of 113 (27%) AFLP markers significantly deviated from neutral expectations. Plants with large floral displays or plant with flowers that resembled more O. purpurea had higher female fitness than plants with small floral displays or plants with flowers resembling more O. militaris, suggesting that directional selection may have contributed to the observed patterns of introgression. Conclusions These results indicate that in closely related orchid species hybridization and gene introgression may be partly driven by selection for floral traits of one of the parental types. However, because some pure individuals were still present in the studied population, the parental species appeared to be sufficiently isolated to survive the challenge of sympatry. PMID:22967086

Synthesis of carbon-coated magnetic nanocomposite (Fe3O4@C) and its application for sulfonamide antibiotics removal from water.

PubMed

Bao, Xiaolei; Qiang, Zhimin; Chang, Jih-Hsing; Ben, Weiwei; Qu, Jiuhui

2014-05-01

The occurrence of antibiotics in the environment has recently raised serious concerns regarding their potential threat to human health and aquatic ecosystem. A new magnetic nanocomposite, Fe3O4@C (Fe3O4 coated with carbon), was synthesized, characterized, and then applied to remove five commonly-used sulfonamides (SAs) from water. Due to its combinational merits of the outer functionalized carbon shell and the inner magnetite core, Fe3O4@C exhibited a high adsorption affinity for selected SAs and a fast magnetic separability. The adsorption kinetics of SAs on Fe3O4@C could be expressed by the pseudo second-order model. The adsorption isotherms were fitted well with the Dual-mode model, revealing that the adsorption process consisted of an initial partitioning stage and a subsequent hole-filling stage. Solution pH exerted a strong impact on the adsorption process with the maximum removal efficiencies (74% to 96%) obtained at pH 4.8 for all selected SAs. Electrostatic force and hydrogen bonding were two major driving forces for adsorption, and electron-donor-acceptor interactions may also make a certain contribution. Because the synthesized Fe3O4@C showed comprehensive advantages of high adsorptivity, fast magnetic separability, and prominent reusability, it has potential applications in water treatment. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Genotypic character relationship and phenotypic path coefficient analysis in chili pepper genotypes grown under tropical condition.

PubMed

Usman, Magaji G; Rafii, Mohd Y; Martini, Mohammad Y; Oladosu, Yusuff; Kashiani, Pedram

2017-03-01

Studies on genotypic and phenotypic correlations among characters of crop plants are useful in planning, evaluating and setting selection criteria for the desired characters in a breeding program. The present study aimed to estimate the phenotypic correlation coefficients among yield and yield attributed characters and to work out the direct and indirect effects of yield-related characters on yield per plant using path coefficient analysis. Twenty-six genotypes of chili pepper were laid out in a randomized complete block design with three replications. Yield per plant showed positive and highly significant (P ≤ 0.01) correlations with most of the characters studied at both the phenotypic and genotypic levels. By contrast, disease incidence and days to flowering showed a significant negative association with yield. Fruit weight and number of fruits exerted positive direct effect on yield and also had a positive and significant (P ≤ 0.01) correlation with yield per plant. However, fruit length showed a low negative direct effect with a strong and positive indirect effect through fruit weight on yield and had a positive and significant association with yield. Longer fruits, heavy fruits and a high number of fruits are variables that are related to higher yields of chili pepper under tropical conditions and hence could be used as a reliable indicator in indirect selection for yield. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Renal effects of the novel selective adenosine A1 receptor blocker SLV329 in experimental liver cirrhosis in rats.

PubMed

Hocher, Berthold; Heiden, Susi; von Websky, Karoline; Arafat, Ayman M; Rahnenführer, Jan; Alter, Markus; Kalk, Philipp; Ziegler, Dieter; Fischer, Yvan; Pfab, Thiemo

2011-03-10

Liver cirrhosis is often complicated by an impaired renal excretion of water and sodium. Diuretics tend to further deteriorate renal function. It is unknown whether chronic selective adenosine A(1) receptor blockade, via inhibition of the hepatorenal reflex and the tubuloglomerular feedback, might exert diuretic and natriuretic effects without a reduction of the glomerular filtration rate. In healthy animals intravenous treatment with the novel A(1) receptor antagonist SLV329 resulted in a strong dose-dependent diuretic (up to 3.4-fold) and natriuretic (up to 13.5-fold) effect without affecting creatinine clearance. Male Wistar rats with thioacetamide-induced liver cirrhosis received SLV329, vehicle or furosemide for 12 weeks. The creatinine clearance of cirrhotic animals decreased significantly (-36.5%, p<0.05), especially in those receiving furosemide (-41.9%, p<0.01). SLV329 was able to prevent this decline of creatinine clearance. Mortality was significantly lower in cirrhotic animals treated with SLV329 in comparison to animals treated with furosemide (17% vs. 54%, p<0.05). SLV329 did not relevantly influence the degree of liver fibrosis, kidney histology or expression of hepatic or renal adenosine receptors. In conclusion, chronic treatment with SLV329 prevented the decrease of creatinine clearance in a rat model of liver cirrhosis. Further studies will have to establish whether adenosine A(1) receptor antagonists are clinically beneficial at different stages of liver cirrhosis.

Limited evolutionary divergence of seedlings after the domestication of plant species.

PubMed

Milla, R; Morente-López, J

2015-01-01

The most vulnerable stage in the life of plants is the seedling. The transition from wild to agricultural land that plants experienced during and after domestication implied a noticeable change in the seedlings' environment. Building on current knowledge of seedling ecology, and on previous studies of cassava, we hypothesise that cultivation should have promoted epigeal germination of seedlings, and more exposed and photosynthetic cotyledons. To test this hypothesis, we phenotyped seedling morpho-functional traits in a set of domesticated and wild progenitor accessions of 20 Eudicot herbaceous crop species. Qualitative traits like epi- versus hypogeal germination, leafy versus storage type of cotyledons, or crypto- versus phanerocotyledonar germination, remained conserved during the domestication of all 20 species. Lengths of hypocotyls and epicotyls, of cotyledon petioles, and indices of cotyledon exposure to the aboveground environment changed during evolution under cultivation. However, those changes occurred in diverse directions, depending on the crop species. No common seedling phenotypic convergence in response to domestication was thus detected among the group of species studied here. Also, none of the 20 crops evolved in accordance with our initial hypothesis. Our results reject the idea that strong selective filters exerted unconsciously by artificial selection should have resulted in generalised channelling of seedling morphology towards more productive and more herbivore risky phenotypes. This result opens up unexplored opportunities for directional breeding of seedling traits. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Pollinators exert natural selection on flower size and floral display in Penstemon digitalis.

PubMed

Parachnowitsch, Amy L; Kessler, André

2010-10-01

• A major gap in our understanding of floral evolution, especially micro-evolutionary processes, is the role of pollinators in generating patterns of natural selection on floral traits. Here we explicitly tested the role of pollinators in selecting floral traits in a herbaceous perennial, Penstemon digitalis. • We manipulated the effect of pollinators on fitness through hand pollinations and compared phenotypic selection in open- and hand-pollinated plants. • Despite the lack of pollen limitation in our population, pollinators mediated selection on floral size and floral display. Hand pollinations removed directional selection for larger flowers and stabilizing selection on flower number, suggesting that pollinators were the agents of selection on both of these traits. • We reviewed studies that measured natural selection on floral traits by biotic agents and generally found stronger signatures of selection imposed by pollinators than by herbivores and co-flowering plant species. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Fluorophore labeling of a cell-penetrating peptide induces differential effects on its cellular distribution and affects cell viability.

PubMed

Birch, Ditlev; Christensen, Malene Vinther; Staerk, Dan; Franzyk, Henrik; Nielsen, Hanne Mørck

2017-12-01

Cell-penetrating peptides constitute efficient delivery vectors, and studies of their uptake and mechanism of translocation typically involve fluorophore-labeled conjugates. In the present study, the influence of a number of specific fluorophores on the physico-chemical properties and uptake-related characteristics of penetratin were studied. An array of seven fluorophores belonging to distinct structural classes was examined, and the impact of fluorophore labeling on intracellular distribution and cytotoxicity was correlated to the physico-chemical properties of the conjugates. Exposure of several mammalian cell types to fluorophore-penetratin conjugates revealed a strong structure-dependent reduction in viability (1.5- to 20-fold lower IC 50 values as compared to those of non-labeled penetratin). Also, the degree of less severe effects on membrane integrity, as well as intracellular distribution patterns differed among the conjugates. Overall, neutral hydrophobic fluorophores or negatively charged fluorophores conferred less cytotoxicity as compared to the effect exerted by positively charged, hydrophobic fluorophores. The latter conjugates, however, exhibited less membrane association and more clearly defined intracellular distribution patterns. Thus, selection of the appropriate flurophore is critical. Copyright © 2017 Elsevier B.V. All rights reserved.

Tmem100 is a regulator of TRPA1-TRPV1 complex and contributes to persistent pain

PubMed Central

Weng, Hao-Jui; Patel, Kush N.; Jeske, Nathaniel A.; Bierbower, Sonya M.; Zou, Wangyuan; Tiwari, Vinod; Zheng, Qin; Tang, Zongxiang; Mo, Gary C.H.; Wang, Yan; Geng, Yixun; Zhang, Jin; Guan, Yun; Akopian, Armen; Dong, Xinzhong

2014-01-01

SUMMARY TRPA1 and TRPV1 are crucial pain mediators, but how their interaction contributes to persistent pain is unknown. Here, we identify Tmem100 as a potentiating modulator of TRPA1-V1 complexes. Tmem100 is co-expressed and forms a complex with TRPA1 and TRPV1 in DRG neurons. Tmem100-deficient mice show a reduction in inflammatory mechanical hyperalgesia and TRPA1- but not TRPV1-mediated pain. Single-channel recording in a heterologous system reveals that Tmem100 selectively potentiates TRPA1 activity in a TRPV1-dependent manner. Mechanistically, Tmem100 weakens the association of TRPA1 and TRPV1, thereby releasing the inhibition of TRPA1 by TRPV1. A Tmem100 mutant, Tmem100-3Q, exerts the opposite effect, i.e., it enhances the association of TRPA1 and TRPV1 and strongly inhibits TRPA1. Strikingly, a cell-permeable peptide (CPP) containing the C-terminal sequence of Tmem100-3Q mimics its effect and inhibits persistent pain. Our study unveils a context-dependent modulation of the TRPA1-V1 complex, and Tmem100-3Q CPP is a promising pain therapy. PMID:25640077

Calcification response of a key phytoplankton family to millennial-scale environmental change

NASA Astrophysics Data System (ADS)

McClelland, H. L. O.; Barbarin, N.; Beaufort, L.; Hermoso, M.; Ferretti, P.; Greaves, M.; Rickaby, R. E. M.

2016-09-01

Coccolithophores are single-celled photosynthesizing marine algae, responsible for half of the calcification in the surface ocean, and exert a strong influence on the distribution of carbon among global reservoirs, and thus Earth’s climate. Calcification in the surface ocean decreases the buffering capacity of seawater for CO2, whilst photosynthetic carbon fixation has the opposite effect. Experiments in culture have suggested that coccolithophore calcification decreases under high CO2 concentrations ([CO2(aq)]) constituting a negative feedback. However, the extent to which these results are representative of natural populations, and of the response over more than a few hundred generations is unclear. Here we describe and apply a novel rationale for size-normalizing the mass of the calcite plates produced by the most abundant family of coccolithophores, the Noëlaerhabdaceae. On average, ancient populations subjected to coupled gradual increases in [CO2(aq)] and temperature over a few million generations in a natural environment become relatively more highly calcified, implying a positive climatic feedback. We hypothesize that this is the result of selection manifest in natural populations over millennial timescales, so has necessarily eluded laboratory experiments.

Direct projections from hypothalamic orexin neurons to brainstem cardiac vagal neurons.

PubMed

Dergacheva, Olga; Yamanaka, Akihiro; Schwartz, Alan R; Polotsky, Vsevolod Y; Mendelowitz, David

2016-12-17

Orexin neurons are known to augment the sympathetic control of cardiovascular function, however the role of orexin neurons in parasympathetic cardiac regulation remains unclear. To test the hypothesis that orexin neurons contribute to parasympathetic control we selectively expressed channelrhodopsin-2 (ChR2) in orexin neurons in orexin-Cre transgenic rats and examined postsynaptic currents in cardiac vagal neurons (CVNs) in the dorsal motor nucleus of the vagus (DMV). Simultaneous photostimulation and recording in ChR2-expressing orexin neurons in the lateral hypothalamus resulted in reliable action potential firing as well as large whole-cell currents suggesting a strong expression of ChR2 and reliable optogenetic excitation. Photostimulation of ChR2-expressing fibers in the DMV elicited short-latency (ranging from 3.2ms to 8.5ms) postsynaptic currents in 16 out of 44 CVNs tested. These responses were heterogeneous and included excitatory glutamatergic (63%) and inhibitory GABAergic (37%) postsynaptic currents. The results from this study suggest different sub-population of orexin neurons may exert diverse influences on brainstem CVNs and therefore may play distinct functional roles in parasympathetic control of the heart. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Poison frog colors are honest signals of toxicity, particularly for bird predators.

PubMed

Maan, Martine E; Cummings, Molly E

2012-01-01

Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

Analyzing Arabidopsis thaliana root proteome provides insights into the molecular bases of enantioselective imazethapyr toxicity

PubMed Central

Qian, Haifeng; Lu, Haiping; Ding, Haiyan; Lavoie, Michel; Li, Yali; Liu, Weiping; Fu, Zhengwei

2015-01-01

Imazethapyr (IM) is a widely used chiral herbicide that inhibits the synthesis of branched-chain amino acids (BCAAs). IM is thought to exert its toxic effects on amino acid synthesis mainly through inhibition of acetolactate synthase activity, but little is known about the potential effects of IM on other key biochemical pathways. Here, we exposed the model plant Arabidospsis thaliana to trace S- and R-IM enantiomer concentrations and examined IM toxicity effects on the root proteome using iTRAQ. Conventional analyses of root carbohydrates, organic acids, and enzyme activities were also performed. We discovered several previously unknown key biochemical pathways targeted by IM in Arabidospsis. 1,322 and 987 proteins were differentially expressed in response to R- and S-IM treatments, respectively. Bioinformatics and physiological analyses suggested that IM reduced the BCAA tissue content not only by strongly suppressing BCAA synthesis but also by increasing BCAA catabolism. IM also affected sugar and starch metabolism, changed the composition of root cell walls, increased citrate production and exudation, and affected the microbial community structure of the rhizosphere. The present study shed new light on the multiple toxicity mechanisms of a selective herbicide on a model plant. PMID:26153126

Analyzing Arabidopsis thaliana root proteome provides insights into the molecular bases of enantioselective imazethapyr toxicity

NASA Astrophysics Data System (ADS)

Qian, Haifeng; Lu, Haiping; Ding, Haiyan; Lavoie, Michel; Li, Yali; Liu, Weiping; Fu, Zhengwei

2015-07-01

Imazethapyr (IM) is a widely used chiral herbicide that inhibits the synthesis of branched-chain amino acids (BCAAs). IM is thought to exert its toxic effects on amino acid synthesis mainly through inhibition of acetolactate synthase activity, but little is known about the potential effects of IM on other key biochemical pathways. Here, we exposed the model plant Arabidospsis thaliana to trace S- and R-IM enantiomer concentrations and examined IM toxicity effects on the root proteome using iTRAQ. Conventional analyses of root carbohydrates, organic acids, and enzyme activities were also performed. We discovered several previously unknown key biochemical pathways targeted by IM in Arabidospsis. 1,322 and 987 proteins were differentially expressed in response to R- and S-IM treatments, respectively. Bioinformatics and physiological analyses suggested that IM reduced the BCAA tissue content not only by strongly suppressing BCAA synthesis but also by increasing BCAA catabolism. IM also affected sugar and starch metabolism, changed the composition of root cell walls, increased citrate production and exudation, and affected the microbial community structure of the rhizosphere. The present study shed new light on the multiple toxicity mechanisms of a selective herbicide on a model plant.

Reactivation of epigenetically silenced miR-512 and miR-373 sensitizes lung cancer cells to cisplatin and restricts tumor growth

PubMed Central

Adi Harel, S; Bossel Ben-Moshe, N; Aylon, Y; Bublik, D R; Moskovits, N; Toperoff, G; Azaiza, D; Biagoni, F; Fuchs, G; Wilder, S; Hellman, A; Blandino, G; Domany, E; Oren, M

2015-01-01

MicroRNAs (miRs) regulate a variety of cellular processes, and their impaired expression is involved in cancer. Silencing of tumor-suppressive miRs in cancer can occur through epigenetic modifications, including DNA methylation and histone deacetylation. We performed comparative miR profiling on cultured lung cancer cells before and after treatment with 5′aza-deoxycytidine plus Trichostatin A to reverse DNA methylation and histone deacetylation, respectively. Several tens of miRs were strongly induced by such ‘epigenetic therapy'. Two representatives, miR-512-5p (miR-512) and miR-373, were selected for further analysis. Both miRs were secreted in exosomes. Re-expression of both miRs augmented cisplatin-induced apoptosis and inhibited cell migration; miR-512 also reduced cell proliferation. TEAD4 mRNA was confirmed as a direct target of miR-512; likewise, miR-373 was found to target RelA and PIK3CA mRNA directly. Our results imply that miR-512 and miR-373 exert cell-autonomous and non-autonomous tumor-suppressive effects in lung cancer cells, where their re-expression may benefit epigenetic cancer therapy. PMID:25591738

Evolution of local facilitation in arid ecosystems.

PubMed

Kéfi, Sonia; van Baalen, Minus; Rietkerk, Max; Loreau, Michel

2008-07-01

In harsh environments, sessile organisms can make their habitat more hospitable by buffering environmental stress or increasing resource availability. Although the ecological significance of such local facilitation is widely established, the evolutionary aspects have been seldom investigated. Yet addressing the evolutionary aspects of local facilitation is important because theoretical studies show that systems with such positive interactions can exhibit alternative stable states and that such systems may suddenly become extinct when they evolve (evolutionary suicide). Arid ecosystems currently experience strong changes in climate and human pressures, but little is known about the effects of these changes on the selective pressures exerted on the vegetation. Here, we focus on the evolution of local facilitation in arid ecosystems, using a lattice-structured model explicitly considering local interactions among plants. We found that the evolution of local facilitation depends on the seed dispersal strategy. In systems characterized by short-distance seed dispersal, adaptation to a more stressful environment leads to high local facilitation, allowing the population to escape extinction. In contrast, systems characterized by long-distance seed dispersal become extinct under increased stress even when allowed to adapt. In this case, adaptation in response to climate change and human pressures could give the final push to the desertification of arid ecosystems.

Dietary supplementation with sorbitol results in selective enrichment of lactobacilli in rat intestine.

PubMed

Sarmiento-Rubiano, Luz Adriana; Zúñiga, Manuel; Pérez-Martínez, Gaspar; Yebra, María Jesús

2007-01-01

A potential prebiotic action has been ascribed to sorbitol, but in vivo evidence of this remains scarce. In the present work, the effect of sorbitol was compared to that of fructo-oligosaccharides (FOS) in a rat model. Microbiota changes, particularly in lactobacilli, were analyzed on fecal, colonic and cecal samples. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene amplicons using universal primers showed that FOS and sorbitol diets exerted a strong influence upon gut microbiota patterns. When Lactobacillus group-specific primers were used, DGGE profiles revealed five DNA bands that belonged to Lactobacillus johnsonii, Lactobacillus sp. AD102, Lactobacillus intestinalis, Lactobacillus murinus and Lactobacillus reuteri. Although these species are present in all dietary groups, quantification by real-time PCR showed that sorbitol and FOS intake increased L. reuteri cell numbers, and sorbitol also contributed to maintaining the levels of Lactobacillus sp. AD102. Analysis of organic acid concentrations showed that sorbitol intake significantly increased colonic and cecal butyrate levels. Hence, sorbitol, which is widely used as a low-calorie sweetener, has the capacity, in our animal model, to modify gut microbiota activity in such a way as to possibly contribute to healthy colonic mucosa.

Diet and Inflammation: Possible Effects on Immunity, Chronic Diseases, and Life Span.

PubMed

Ricordi, Camillo; Garcia-Contreras, Marta; Farnetti, Sara

2015-01-01

Chronic inflammation negatively impacts all physiological functions, causing an array of degenerative conditions including diabetes; cancer; cardiovascular, osteo-articular, and neurodegenerative diseases; autoimmunity disorders; and aging. In particular, there is a growing knowledge of the role that gene transcription factors play in the inflammatory process. Obesity, metabolic syndrome, and diabetes represent multifactorial conditions resulting from improper balances of hormones and gene expression. In addition, these conditions have a strong inflammatory component that can potentially be impacted by the diet. It can reduce pro-inflammatory eicosanoids that can alter hormonal signaling cascades to the modulation of the innate immune system and gene transcription factors. Working knowledge of the impact of how nutrients, especially dietary fatty acids and polyphenols, can impact these various molecular targets makes it possible to develop a general outline of an anti-inflammatory diet that offers a unique, nonpharmacological approach in treating obesity, metabolic syndrome, and diabetes. Several important bioactive dietary components can exert their effect through selected inflammatory pathways that can affect metabolic and genetic changes. In fact, dietary components that can modulate glucose and insulin levels, as well as any other mediator that can activate nuclear factor-kB, can also trigger inflammation through common pathway master switches.

Life-long intellectual activities mediate the predictive effect of early education on cognitive impairment in centenarians: a retrospective study.

PubMed

Kliegel, M; Zimprich, D; Rott, C

2004-09-01

The purpose of this study was to examine the hypothesis of whether early education and/or maintaining intellectual activities over the life-course have the power to protect against cognitive impairment even in extremely old adults. Ninety centenarians from the population-based Heidelberg Centenarian Study were assessed with a modified version of the Mini Mental State Exam (MMSE). Data about education, occupational status, and life-long intellectual activities in four selected domains were obtained. Results demonstrated that 52% of the sample showed mild-to-severe cognitive impairment. Analyzing the influence of early education, occupational status, and intellectual activities on cognitive status we applied several (logistic) regression analyses. Results revealed independent, significant and strong influence of both formal school education and intellectual activities on the cognitive status in very late life, even after controlling for occupational status. However, about one fourth of the effect of early education on cognitive status was exerted indirectly via the assessed intellectual activities. In summary, the present study provides first evidence for the conclusion that even with regard to cognitive performance in very old age, both early education and life-long intellectual activities seem to be of importance.

Segmentation of white rat sperm image

NASA Astrophysics Data System (ADS)

Bai, Weiguo; Liu, Jianguo; Chen, Guoyuan

2011-11-01

The segmentation of sperm image exerts a profound influence in the analysis of sperm morphology, which plays a significant role in the research of animals' infertility and reproduction. To overcome the microscope image's properties of low contrast and highly polluted noise, and to get better segmentation results of sperm image, this paper presents a multi-scale gradient operator combined with a multi-structuring element for the micro-spermatozoa image of white rat, as the multi-scale gradient operator can smooth the noise of an image, while the multi-structuring element can retain more shape details of the sperms. Then, we use the Otsu method to segment the modified gradient image whose gray scale processed is strong in sperms and weak in the background, converting it into a binary sperm image. As the obtained binary image owns impurities that are not similar with sperms in the shape, we choose a form factor to filter those objects whose form factor value is larger than the select critical value, and retain those objects whose not. And then, we can get the final binary image of the segmented sperms. The experiment shows this method's great advantage in the segmentation of the micro-spermatozoa image.

Calcification response of a key phytoplankton family to millennial-scale environmental change

PubMed Central

McClelland, H. L. O.; Barbarin, N.; Beaufort, L.; Hermoso, M.; Ferretti, P.; Greaves, M.; Rickaby, R. E. M.

2016-01-01

Coccolithophores are single-celled photosynthesizing marine algae, responsible for half of the calcification in the surface ocean, and exert a strong influence on the distribution of carbon among global reservoirs, and thus Earth’s climate. Calcification in the surface ocean decreases the buffering capacity of seawater for CO2, whilst photosynthetic carbon fixation has the opposite effect. Experiments in culture have suggested that coccolithophore calcification decreases under high CO2 concentrations ([CO2(aq)]) constituting a negative feedback. However, the extent to which these results are representative of natural populations, and of the response over more than a few hundred generations is unclear. Here we describe and apply a novel rationale for size-normalizing the mass of the calcite plates produced by the most abundant family of coccolithophores, the Noëlaerhabdaceae. On average, ancient populations subjected to coupled gradual increases in [CO2(aq)] and temperature over a few million generations in a natural environment become relatively more highly calcified, implying a positive climatic feedback. We hypothesize that this is the result of selection manifest in natural populations over millennial timescales, so has necessarily eluded laboratory experiments. PMID:27677230

Physiologic and perceptual responses during treadmill running with ankle weights.

PubMed

Bhambhani, Y N; Gomes, P S; Wheeler, G

1990-03-01

This study examined the effects of ankle weighting on physiologic and perceptual responses during treadmill running in seven healthy, female recreational runners with a mean maximal aerobic power of 48.4 +/- 4.0 ml/kg/min. Each subject completed four experimental one-mile runs at individually selected treadmill running speeds with 0, 1.6, 3.2 and 4.8 kg weights on their ankles. The subjects selected a speed at which they would run (train) if their objectives were to significantly improve cardiovascular function and induce weight loss. Metabolic and cardiovascular responses were continuously monitored, and ratings of perceived exertion were recorded near the end of the activity. During the unweighted run, the subjects selected a running speed of 6.87 +/- 0.63 mph which resulted in a net energy expenditure of 0.153 kcal/kg/min or 1.34 +/- 0.16 kcal/kg/mile. This corresponded to a training intensity of 76.3% +/- 5.1% of maximum oxygen consumption or 88.1% +/- 9.7% of maximum heart rate. Addition of weight to the ankles caused a significant decrease (p less than .05) in the running speed selected and, therefore, did not result in any significant changes (p greater than .05) in the rate of oxygen consumption, heart rate or ratings of perceived exertion when compared to the unweighted condition. These observations are in contrast to previous studies on ankle weighting which were conducted at fixed treadmill running speeds. However, the use of ankle weights did have a tendency to increase gross and net energy expenditure of running when values were expressed in kcal/mile because of slower self-selected running speeds under these conditions. This increase in energy expenditure could be of physiologic significance if running with ankle weights was performed on a regular basis at a fixed distance.

Acute loss of TET function results in aggressive myeloid cancer in mice

PubMed Central

An, Jungeun; González-Avalos, Edahí; Chawla, Ashu; Jeong, Mira; López-Moyado, Isaac F.; Li, Wei; Goodell, Margaret A.; Chavez, Lukas; Ko, Myunggon; Rao, Anjana

2015-01-01

TET-family dioxygenases oxidize 5-methylcytosine (5mC) in DNA, and exert tumour suppressor activity in many types of cancers. Even in the absence of TET coding region mutations, TET loss-of-function is strongly associated with cancer. Here we show that acute elimination of TET function induces the rapid development of an aggressive, fully-penetrant and cell-autonomous myeloid leukaemia in mice, pointing to a causative role for TET loss-of-function in this myeloid malignancy. Phenotypic and transcriptional profiling shows aberrant differentiation of haematopoietic stem/progenitor cells, impaired erythroid and lymphoid differentiation and strong skewing to the myeloid lineage, with only a mild relation to changes in DNA modification. We also observe progressive accumulation of phospho-H2AX and strong impairment of DNA damage repair pathways, suggesting a key role for TET proteins in maintaining genome integrity. PMID:26607761

Dust particles interaction with plasma jet

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

Ticos, C. M.; Jepu, I.; Lungu, C. P.

2009-11-10

The flow of plasma and particularly the flow of ions play an important role in dusty plasmas. Here we present some instances in laboratory experiments where the ion flow is essential in establishing dust dynamics in strongly or weakly coupled dust particles. The formation of ion wake potential and its effect on the dynamics of dust crystals, or the ion drag force exerted on micron size dust grains are some of the phenomena observed in the presented experiments.

Cloud-Scale Numerical Modeling of the Arctic Boundary Layer

NASA Technical Reports Server (NTRS)

Krueger, Steven K.

1998-01-01

The interactions between sea ice, open ocean, atmospheric radiation, and clouds over the Arctic Ocean exert a strong influence on global climate. Uncertainties in the formulation of interactive air-sea-ice processes in global climate models (GCMs) result in large differences between the Arctic, and global, climates simulated by different models. Arctic stratus clouds are not well-simulated by GCMs, yet exert a strong influence on the surface energy budget of the Arctic. Leads (channels of open water in sea ice) have significant impacts on the large-scale budgets during the Arctic winter, when they contribute about 50 percent of the surface fluxes over the Arctic Ocean, but cover only 1 to 2 percent of its area. Convective plumes generated by wide leads may penetrate the surface inversion and produce condensate that spreads up to 250 km downwind of the lead, and may significantly affect the longwave radiative fluxes at the surface and thereby the sea ice thickness. The effects of leads and boundary layer clouds must be accurately represented in climate models to allow possible feedbacks between them and the sea ice thickness. The FIRE III Arctic boundary layer clouds field program, in conjunction with the SHEBA ice camp and the ARM North Slope of Alaska and Adjacent Arctic Ocean site, will offer an unprecedented opportunity to greatly improve our ability to parameterize the important effects of leads and boundary layer clouds in GCMs.

Strong contributions from vertical triads to helix-partner preferences in parallel coiled coils.

PubMed

Steinkruger, Jay D; Bartlett, Gail J; Woolfson, Derek N; Gellman, Samuel H

2012-09-26

Pairing preferences in heterodimeric coiled coils are determined by complementarities among side chains that pack against one another at the helix-helix interface. However, relationships between dimer stability and interfacial residue identity are not fully understood. In the context of the "knobs-into-holes" (KIH) packing pattern, one can identify two classes of interactions between side chains from different helices: "lateral", in which a line connecting the adjacent side chains is perpendicular to the helix axes, and "vertical", in which the connecting line is parallel to the helix axes. We have previously analyzed vertical interactions in antiparallel coiled coils and found that one type of triad constellation (a'-a-a') exerts a strong effect on pairing preferences, while the other type of triad (d'-d-d') has relatively little impact on pairing tendencies. Here, we ask whether vertical interactions (d'-a-d') influence pairing in parallel coiled-coil dimers. Our results indicate that vertical interactions can exert a substantial impact on pairing specificity, and that the influence of the d'-a-d' triad depends on the lateral a' contact within the local KIH motif. Structure-informed bioinformatic analyses of protein sequences reveal trends consistent with the thermodynamic data derived from our experimental model system in suggesting that heterotriads involving Leu and Ile are preferred over homotriads involving Leu and Ile.

Perceptual integration of motion and form information: evidence of parallel-continuous processing.

PubMed

von Mühlenen, A; Müller, H J

2000-04-01

In three visual search experiments, the processes involved in the efficient detection of motion-form conjunction targets were investigated. Experiment 1 was designed to estimate the relative contributions of stationary and moving nontargets to the search rate. Search rates were primarily determined by the number of moving nontargets; stationary nontargets sharing the target form also exerted a significant effect, but this was only about half as strong as that of moving nontargets; stationary nontargets not sharing the target form had little influence. In Experiments 2 and 3, the effects of display factors influencing the visual (form) quality of moving items (movement speed and item size) were examined. Increasing the speed of the moving items (> 1.5 degrees/sec) facilitated target detection when the task required segregation of the moving from the stationary items. When no segregation was necessary, increasing the movement speed impaired performance: With large display items, motion speed had little effect on target detection, but with small items, search efficiency declined when items moved faster than 1.5 degrees/sec. This pattern indicates that moving nontargets exert a strong effect on the search rate (Experiment 1) because of the loss of visual quality for moving items above a certain movement speed. A parallel-continuous processing account of motion-form conjunction search is proposed, which combines aspects of Guided Search (Wolfe, 1994) and attentional engagement theory (Duncan & Humphreys, 1989).

Strong Enhancement of the Spin Hall Effect by Spin Fluctuations near the Curie Point of FexPt1 -x Alloys

NASA Astrophysics Data System (ADS)

Ou, Yongxi; Ralph, D. C.; Buhrman, R. A.

2018-03-01

Robust spin Hall effects (SHE) have recently been observed in nonmagnetic heavy metal systems with strong spin-orbit interactions. These SHE are either attributed to an intrinsic band-structure effect or to extrinsic spin-dependent scattering from impurities, namely, side jump or skew scattering. Here we report on an extraordinarily strong spin Hall effect, attributable to spin fluctuations, in ferromagnetic FexPt1 -x alloys near their Curie point, tunable with x . This results in a dampinglike spin-orbit torque being exerted on an adjacent ferromagnetic layer that is strongly temperature dependent in this transition region, with a peak value that indicates a lower bound 0.34 ±0.02 for the peak spin Hall ratio within the FePt. We also observe a pronounced peak in the effective spin-mixing conductance of the FM /FePt interface, and determine the spin diffusion length in these FexPt1 -x alloys. These results establish new opportunities for fundamental studies of spin dynamics and transport in ferromagnetic systems with strong spin fluctuations, and a new pathway for efficiently generating strong spin currents for applications.

The Chandra Strong Lens Sample: Revealing Baryonic Physics In Strong Lensing Selected Clusters

NASA Astrophysics Data System (ADS)

Bayliss, Matthew

2017-08-01

We propose for Chandra imaging of the hot intra-cluster gas in a unique new sample of 29 galaxy clusters selected purely on their strong gravitational lensing signatures. This will be the first program targeting a purely strong lensing selected cluster sample, enabling new comparisons between the ICM properties and scaling relations of strong lensing and mass/ICM selected cluster samples. Chandra imaging, combined with high precision strong lens models, ensures powerful constraints on the distribution and state of matter in the cluster cores. This represents a novel angle from which we can address the role played by baryonic physics |*| the infamous |*|gastrophysics|*| in shaping the cores of massive clusters, and opens up an exciting new galaxy cluster discovery space with Chandra.

The Chandra Strong Lens Sample: Revealing Baryonic Physics In Strong Lensing Selected Clusters

NASA Astrophysics Data System (ADS)

Bayliss, Matthew

2017-09-01

We propose for Chandra imaging of the hot intra-cluster gas in a unique new sample of 29 galaxy clusters selected purely on their strong gravitational lensing signatures. This will be the first program targeting a purely strong lensing selected cluster sample, enabling new comparisons between the ICM properties and scaling relations of strong lensing and mass/ICM selected cluster samples. Chandra imaging, combined with high precision strong lens models, ensures powerful constraints on the distribution and state of matter in the cluster cores. This represents a novel angle from which we can address the role played by baryonic physics -- the infamous ``gastrophysics''-- in shaping the cores of massive clusters, and opens up an exciting new galaxy cluster discovery space with Chandra.

Motivated to do well: an examination of the relationships between motivation, effort, and cognitive performance in schizophrenia.

PubMed

Foussias, G; Siddiqui, I; Fervaha, G; Mann, S; McDonald, K; Agid, O; Zakzanis, K K; Remington, G

2015-08-01

The uncertain relationship between negative symptoms, and specifically motivational deficits, with cognitive dysfunction in schizophrenia is in need of further elucidation as it pertains to the interpretation of cognitive test results. Findings to date have suggested a possible mediating role of motivational deficits on cognitive test measures, although findings from formal examinations of effort using performance validity measures have been inconsistent. The aim of this study was to examine the relationships between motivation, effort exerted during cognitive testing, and cognitive performance in schizophrenia. Sixty-nine outpatients with schizophrenia or schizoaffective disorder were evaluated for psychopathology, severity of motivational deficits, effort exerted during cognitive testing, and cognitive performance. Motivation and degree of effort exerted during cognitive testing were significantly related to cognitive performance, specifically verbal fluency, verbal and working memory, attention and processing speed, and reasoning and problem solving. Further, effort accounted for 15% of the variance in cognitive performance, and partially mediated the relationship between motivation and cognitive performance. Examining cognitive performance profiles for individuals exerting normal or reduced effort revealed significant differences in global cognition, as well as attention/processing speed and reasoning and problem solving. These findings suggest that cognitive domains may be differentially affected by impairments in motivation and effort, and highlight the importance of understanding the interplay between motivation and cognitive performance deficits, which may guide the appropriate selection of symptom targets for promoting recovery in patients. Copyright © 2015 Elsevier B.V. All rights reserved.

Parent-Child Attunement Moderates the Prospective Link between Parental Overcontrol and Adolescent Adjustment.

PubMed

Miller, Kelly F; Borelli, Jessica L; Margolin, Gayla

2017-10-22

Parental overcontrol (OC), behavior that intrusively or dominantly restricts child autonomy, has been identified as a transdiagnostic risk factor for youth. However, it is as yet unknown whether the association between parental OC and child maladjustment remains even when OC is exerted infrequently or by attuned parents. Rather, the selective use of OC might steer children away from danger. Taking a developmental psychopathology approach, this study focuses on the larger parent-child relationship context, testing whether either the dose at which parents demonstrate OC or the degree to which children perceive their parents as attuned determines whether OC is risky or protective for adolescents' adjustment. Among a community sample of 114 families of children followed from the ages of 12-18, we examine whether OC, behaviorally coded from triadic mother-father-child discussions in middle childhood, is associated with later risky behavior and anxiety symptoms in adolescence. Overcontrol exerted by either mothers or fathers had a curvilinear effect on adolescent risky behaviors, and this effect was moderated by children's perceived attunement. Although OC generally was associated with increased risky behaviors, low doses of OC or OC exerted by highly attuned parents protected against engagement in risky behaviors. No main effect of OC was observed on adolescent anxiety; however, mothers' OC interacted with perceived parental attunement, such that OC exerted by less attuned parents predicted greater anxiety. Results underscore that the effect of parenting behaviors depends on the larger parent-child relationship context. © 2017 Family Process Institute.

Metoprolol vs ivabradine in patients with mitral stenosis in sinus rhythm.

PubMed

Agrawal, Vikas; Kumar, Niraj; Lohiya, Balalji; Sihag, Bhupendra K; Prajapati, Rajpal; Singh, T B; Subramanian, Geetha

2016-10-15

Severe mitral stenosis is usually symptomatic and is treated by BMV or surgery, whereas mild to moderate mitral stenosis is usually asymptomatic or mildly symptomatic and managed medically. Patients in the later group may become symptomatic during episodes of exercise and increased heart rate. Beta-blockers are frequently used in patients with mitral stenosis to control the heart rate and alleviate exercise-related symptoms. The objective of our study was to investigate the comparative efficacy of ivabradine versus metoprolol in patients with mitral stenosis in sinus rhythm. We studied 97 patients of mitral stenosis in sinus rhythm presented with exertional symptoms. The effectiveness of Metoprolol was compared with ivabradine in alleviating these exertional symptoms in a randomized, open label non crossover study. We also assessed various stress ECG parameters, 24 hour Holter parameters and 2D Echo parameters to objectively compare the effects of ivabradine and metoprolol in these patients. Ivabradine and metoprolol both were effective in controlling exertional symptoms. Significant improvement in objective parameters like TMT (work capacity, baseline heart rate and maximal heart rate) and 2D echocardiography (right ventricular systolic pressure) are seen with both drugs. Ivabradine controls the exertional symptoms significantly more than metoprolol. On head to head comparison there was a significant benefit of working capacity and heart rate at maximal exercise in favour of ivabradine. Ivabradine should be strongly considered in medical management of mitral stenosis patients where beta blockers are contraindicated such as reactive airway disease. The cost of ivabradine is higher than metoprolol which might possess constraints as most of the rheumatic heat disease patients belong to low socio economic status. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Trypanocidal and Leishmanicidal Activities of Sesquiterpene Lactones from Ambrosia tenuifolia Sprengel (Asteraceae) ▿

PubMed Central

Sülsen, Valeria P.; Frank, Fernanda M.; Cazorla, Silvia I.; Anesini, Claudia A.; Malchiodi, Emilio L.; Freixa, Blanca; Vila, Roser; Muschietti, Liliana V.; Martino, Virginia S.

2008-01-01

Bioassay-guided fractionation of the organic extract of Ambrosia tenuifolia Sprengel (Asteraceae) led to the isolation of two bioactive sesquiterpene lactones with significant trypanocidal and leishmanicidal activities. By spectroscopic methods (1H- and 13C-nuclear magnetic resonance, distortionless enhancement by polarization transfer, correlated spectroscopy, heteronuclear multiple-quantum coherence, electron impact-mass spectrometry, and infrared spectroscopy), these compounds were identified as psilostachyin and peruvin. Both compounds showed a marked in vitro trypanocidal activity against Trypanosoma cruzi epimastigotes with 50% inhibitory concentration (IC50) values of less than 2 μg/ml. Psilostachyin exerted a significant in vitro activity against the trypomastigote forms of T. cruzi (IC50, 0.76 μg/ml) and was selected for in vivo testing. Psilostachyin-treated mice had a survival of 100% and lower parasitemia values than control mice. Both compounds were also tested on Leishmania sp. promastigotes: psilostachyin (IC50, 0.12 μg/ml) and peruvin (IC50, 0.39 μg/ml) exerted significant leishmanicidal activities. This is the first time that the trypanocidal and leishmanicidal activities of these compounds have been reported. The selectivity index (SI) was employed to evaluate the cytotoxic effect of lactones on T lymphocytes. Although the SIs of both compounds were high for T. cruzi epimastigotes, psilostachyin was more selective against trypomastigotes (SI, 33.8) while peruvin showed no specificity for this parasite. Both compounds presented high selectivity for Leishmania spp. The results shown herein suggest that psilostachyin and peruvin could be considered potential candidates for the development of new antiprotozoal agents against Chagas' disease and leishmaniasis. PMID:18443111

Happy but still focused: failures to find evidence for a mood-induced widening of visual attention.

PubMed

Bruyneel, Lynn; van Steenbergen, Henk; Hommel, Bernhard; Band, Guido P H; De Raedt, Rudi; Koster, Ernst H W

2013-05-01

In models of affect and cognition, it is held that positive affect broadens the scope of attention. Consistent with this claim, previous research has indeed suggested that positive affect is associated with impaired selective attention as evidenced by increased interference of spatially distant distractors. However, several recent findings cast doubt on the reliability of this observation. In the present study, we examined whether selective attention in a visual flanker task is influenced by positive mood induction. Across three experiments, positive affect consistently failed to exert any impact on selective attention. The implications of this null-finding for theoretical models of affect and cognition are discussed.

State/Trait Anxiety and Anxiolytic Effects of Acute Physical Exercises

ERIC Educational Resources Information Center

Guszkowska, Monika

2009-01-01

Study aim: To determine anxiolytic effects of acute physical exertions in relation to the initial anxiety state and trait in women. Material and methods: A group of 163 women aged 16-56 years, attending fitness clubs in Warsaw, participated in the study. They selected a single exercise to perform--strength, aerobic or mixed, lasting 30 to over 60…

The formation of dense understory layers in forests worldwide: consequences and implications for forest dynamics, biodiversity, and succession

Treesearch

Alejandro A. Royo; Walter P. Carson

2010-01-01

Alterations to natural herbivore and disturbance regimes often allow a select suite of forest understory plant species to dramatically spread and form persistent, mono-dominant thickets. Following their expansion, this newly established understory canopy can alter tree seedling recruitment rates and exert considerable control over the rate and direction of secondary...

The formation of dense understory layers in the forest worldwide: consequences and implications for forest dynamics, biodiversity, and succession

Treesearch

Alejandro A. Royo; Walter P. Carson

2010-01-01

Alterations to natural herbivore and disturbance regimes often allow a select suite of forest understory plant species to dramatically spread and form persistent, mono-dominant thickets. Following their expansion, this newly established understory canopy can alter tree seedling recruitment rates and exert considerable control over the rate and direction of secondary...

Changes in bacterial community after application of three different herbicides.

PubMed

Moretto, Jéssica Aparecida Silva; Altarugio, Lucas Miguel; Andrade, Pedro Avelino; Fachin, Ana Lúcia; Andreote, Fernando Dini; Stehling, Eliana Guedes

2017-07-06

The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The heritage of pathogen pressures and ancient demography in the human innate-immunity CD209/CD209L region.

PubMed

Barreiro, Luis B; Patin, Etienne; Neyrolles, Olivier; Cann, Howard M; Gicquel, Brigitte; Quintana-Murci, Lluís

2005-11-01

The innate immunity system constitutes the first line of host defense against pathogens. Two closely related innate immunity genes, CD209 and CD209L, are particularly interesting because they directly recognize a plethora of pathogens, including bacteria, viruses, and parasites. Both genes, which result from an ancient duplication, possess a neck region, made up of seven repeats of 23 amino acids each, known to play a major role in the pathogen-binding properties of these proteins. To explore the extent to which pathogens have exerted selective pressures on these innate immunity genes, we resequenced them in a group of samples from sub-Saharan Africa, Europe, and East Asia. Moreover, variation in the number of repeats of the neck region was defined in the entire Human Genome Diversity Panel for both genes. Our results, which are based on diversity levels, neutrality tests, population genetic distances, and neck-region length variation, provide genetic evidence that CD209 has been under a strong selective constraint that prevents accumulation of any amino acid changes, whereas CD209L variability has most likely been shaped by the action of balancing selection in non-African populations. In addition, our data point to the neck region as the functional target of such selective pressures: CD209 presents a constant size in the neck region populationwide, whereas CD209L presents an excess of length variation, particularly in non-African populations. An additional interesting observation came from the coalescent-based CD209 gene tree, whose binary topology and time depth (approximately 2.8 million years ago) are compatible with an ancestral population structure in Africa. Altogether, our study has revealed that even a short segment of the human genome can uncover an extraordinarily complex evolutionary history, including different pathogen pressures on host genes as well as traces of admixture among archaic hominid populations.

Dissection of a single rat muscle-tendon complex changes joint moments exerted by neighboring muscles: implications for invasive surgical interventions.

PubMed

Maas, Huub; Baan, Guus C; Huijing, Peter A

2013-01-01

The aim of this paper is to investigate mechanical functioning of a single skeletal muscle, active within a group of (previously) synergistic muscles. For this purpose, we assessed wrist angle-active moment characteristics exerted by a group of wrist flexion muscles in the rat for three conditions: (i) after resection of the upper arm skin; (ii) after subsequent distal tenotomy of flexor carpi ulnaris muscle (FCU); and (iii) after subsequent freeing of FCU distal tendon and muscle belly from surrounding tissues (MT dissection). Measurements were performed for a control group and for an experimental group after recovery (5 weeks) from tendon transfer of FCU to extensor carpi radialis (ECR) insertion. To assess if FCU tenotomy and MT dissection affects FCU contributions to wrist moments exclusively or also those of neighboring wrist flexion muscles, these data were compared to wrist angle-moment characteristics of selectively activated FCU. FCU tenotomy and MT dissection decreased wrist moments of the control group at all wrist angles tested, including also angles for which no or minimal wrist moments were measured when activating FCU exclusively. For the tendon transfer group, wrist flexion moment increased after FCU tenotomy, but to a greater extent than can be expected based on wrist extension moments exerted by selectively excited transferred FCU. We conclude that dissection of a single muscle in any surgical treatment does not only affect mechanical characteristics of the target muscle, but also those of other muscles within the same compartment. Our results demonstrate also that even after agonistic-to-antagonistic tendon transfer, mechanical interactions with previously synergistic muscles do remain present.

Diversity and Ecology of Viruses in Hyperarid Desert Soils

PubMed Central

Zablocki, Olivier; Adriaenssens, Evelien M.

2015-01-01

In recent years, remarkable progress has been made in the field of virus environmental ecology. In marine ecosystems, for example, viruses are now thought to play pivotal roles in the biogeochemical cycling of nutrients and to be mediators of microbial evolution through horizontal gene transfer. The diversity and ecology of viruses in soils are poorly understood, but evidence supports the view that the diversity and ecology of viruses in soils differ substantially from those in aquatic systems. Desert biomes cover ∼33% of global land masses, and yet the diversity and roles of viruses in these dominant ecosystems remain poorly understood. There is evidence that hot hyperarid desert soils are characterized by high levels of bacterial lysogens and low extracellular virus counts. In contrast, cold desert soils contain high extracellular virus titers. We suggest that the prevalence of microbial biofilms in hyperarid soils, combined with extreme thermal regimens, exerts strong selection pressures on both temperate and virulent viruses. Many desert soil virus sequences show low values of identity to virus genomes in public databases, suggesting the existence of distinct and as-yet-uncharacterized soil phylogenetic lineages (e.g., cyanophages). We strongly advocate for amplification-free metavirome analyses while encouraging the classical isolation of phages from dominant and culturable microbial isolates in order to populate sequence databases. This review provides an overview of recent advances in the study of viruses in hyperarid soils and of the factors that contribute to viral abundance and diversity in hot and cold deserts and offers technical recommendations for future studies. PMID:26590289

Aging and response conflict solution: Behavioural and functional connectivity changes

PubMed Central

Cieslik, Edna C.; Behrwind, Simone D.; Roski, Christian; Caspers, Svenja; Amunts, Katrin; Eickhoff, Simon B.

2014-01-01

Healthy aging has been found associated with less efficient response conflict solution, but the cognitive and neural mechanisms remain elusive. In a two-experiment study, we first examined the behavioural consequences of this putative age-related decline for conflicts induced by spatial stimulus–response incompatibility. We then used resting-state functional magnetic resonance imaging data from a large, independent sample of adults (n = 399; 18–85 years) to investigate age differences in functional connectivity between the nodes of a network previously found associated with incompatibility-induced response conflicts in the very same paradigm. As expected, overcoming interference from conflicting response tendencies took longer in older adults, even after accounting for potential mediator variables (general response speed and accuracy, motor speed, visuomotor coordination ability, and cognitive flexibility). Experiment 2 revealed selective age-related decreases in functional connectivity between bilateral anterior insula, pre-supplementary motor area, and right dorsolateral prefrontal cortex. Importantly, these age effects persisted after controlling for regional gray-matter atrophy assessed by voxel-based morphometry. Meta-analytic functional profiling using the BrainMap database showed these age-sensitive nodes to be more strongly linked to highly abstract cognition, as compared with the remaining network nodes, which in turn were more strongly linked to action-related processing. These findings indicate changes in interregional coupling with age among task-relevant network nodes that are not specifically associated with conflict resolution per se. Rather, our behavioural and neural data jointly suggest that healthy aging is associated with difficulties in properly activating non-dominant but relevant task schemata necessary to exert efficient cognitive control over action. PMID:24718622

Aging and response conflict solution: behavioural and functional connectivity changes.

PubMed

Langner, Robert; Cieslik, Edna C; Behrwind, Simone D; Roski, Christian; Caspers, Svenja; Amunts, Katrin; Eickhoff, Simon B

2015-01-01

Healthy aging has been found associated with less efficient response conflict solution, but the cognitive and neural mechanisms have remained elusive. In a two-experiment study, we first examined the behavioural consequences of this putative age-related decline for conflicts induced by spatial stimulus-response incompatibility. We then used resting-state functional magnetic resonance imaging data from a large, independent sample of adults (n = 399; 18-85 years) to investigate age differences in functional connectivity between the nodes of a network previously found associated with incompatibility-induced response conflicts in the very same paradigm. As expected, overcoming interference from conflicting response tendencies took longer in older adults, even after accounting for potential mediator variables (general response speed and accuracy, motor speed, visuomotor coordination ability, and cognitive flexibility). Experiment 2 revealed selective age-related decreases in functional connectivity between bilateral anterior insula, pre-supplementary motor area, and right dorsolateral prefrontal cortex. Importantly, these age effects persisted after controlling for regional grey-matter atrophy assessed by voxel-based morphometry. Meta-analytic functional profiling using the BrainMap database showed these age-sensitive nodes to be more strongly linked to highly abstract cognition, as compared with the remaining network nodes, which were more strongly linked to action-related processing. These findings indicate changes in interregional coupling with age among task-relevant network nodes that are not specifically associated with conflict resolution per se. Rather, our behavioural and neural data jointly suggest that healthy aging is associated with difficulties in properly activating non-dominant but relevant task schemata necessary to exert efficient cognitive control over action.

Metaproteomics of a gutless marine worm and its symbiotic microbial community reveal unusual pathways for carbon and energy use

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

Kleiner, Manuel; Wentrop, C.; Lott, C.

Low nutrient and energy availability has led to the evolution of numerous strategies for overcoming these limitations, of which symbiotic associations represent a key mechanism. Particularly striking are the associations between chemosynthetic bacteria and marine animals that thrive in nutrient-poor environments such as the deep-sea because the symbionts allow their hosts to grow on inorganic energy and carbon sources such as sulfide and CO2. Remarkably little is known about the physiological strategies that enable chemosynthetic symbioses to colonize oligotrophic environments. In this study, we used metaproteomics and metabolomics to investigate the intricate network of metabolic interactions in the chemosynthetic associationmore » between Olavius algarvensis, a gutless marine worm, and its bacterial symbionts. We propose novel pathways for coping with energy and nutrient limitation, some of which may be widespread in both free-living and symbiotic bacteria. These include (i) a pathway for symbiont assimilation of the host waste products acetate, propionate, succinate and malate, (ii) the potential use of carbon monoxide as an energy source, a substrate previously not known to play a role in marine invertebrate symbioses, (iii) the potential use of hydrogen as an energy source, (iv) the strong expression of high affinity uptake transporters, and (v) novel energy efficient steps in CO2 fixation and sulfate reduction. The high expression of proteins involved in pathways for energy and carbon uptake and conservation in the O. algarvensis symbiosis indicates that the oligotrophic nature of its environment exerted a strong selective pressure in shaping these associations.« less

Inhibition of PDGFR by CP-673451 induces apoptosis and increases cisplatin cytotoxicity in NSCLC cells via inhibiting the Nrf2-mediated defense mechanism.

PubMed

Yang, Yang; Deng, Yanchao; Chen, Xiangcui; Zhang, Jiahao; Chen, Yueming; Li, Huachao; Wu, Qipeng; Yang, Zhicheng; Zhang, Luyong; Liu, Bing

2018-05-29

Platelet-derived growth factor receptors (PDGFRs) are abundantly expressed by stromal cells in the non-small cell lung cancer (NSCLC) microenvironment, and in a subset of cancer cells, usually with their overexpression and/or activating mutation. However, the effect of PDGFR inhibition on lung cancer cells themselves has been largely neglected. In this study, we investigated the anticancer activity of CP-673451, a potent and selective inhibitor of PDGFRβ, on NSCLC cell lines (A549 and H358) and the potential mechanism. The results showed that inhibition of PDGFRβ by CP-673451 induced a significant increase in cell apoptosis, accompanied by ROS accumulation. However, CP-673451 exerted less cytotoxicity in normal lung epithelial cell line BEAS-2B cells determined by MTT and apoptosis assay. Elimination of ROS by NAC reversed the CP-673451-induced apoptosis in NSCLC cells. Furthermore, CP-673451 down-regulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) probably through inhibition of PI3K/Akt pathway. Rescue of Nrf2 activity counteracted the effects of CP-673451 on cell apoptosis and ROS accumulation. Silencing PDGFRβ expression by PDGFRβ siRNA exerted similar effects with CP-673451 in A549 cells, and when PDGFRβ was knockdowned by PDGFRβ siRNA, CP-673451 produced no additional effects on cell viability, ROS and GSH production, Nrf2 expression as well as PI3K/Akt pathway activity. Specifically, Nrf2 plays an indispensable role in NSCLC cell sensitivity to platinum-based treatments and we found that combination of CP-673451 and cisplatin produced a synergistic anticancer effect and substantial ROS production in vitro. Therefore, these results clearly demonstrate the effectiveness of inhibition of PDGFRβ against NSCLC cells and strongly suggest that CP-673451 may be a promising adjuvant chemotherapeutic drug. Copyright © 2018 Elsevier B.V. All rights reserved.

Negative feedback exerted by cAMP-dependent protein kinase and cAMP phosphodiesterase on subsarcolemmal cAMP signals in intact cardiac myocytes: an in vivo study using adenovirus-mediated expression of CNG channels.

PubMed

Rochais, Francesca; Vandecasteele, Grégoire; Lefebvre, Florence; Lugnier, Claire; Lum, Hazel; Mazet, Jean-Luc; Cooper, Dermot M F; Fischmeister, Rodolphe

2004-12-10

Intracardiac cAMP levels are modulated by hormones and neuromediators with specific effects on contractility and metabolism. To understand how the same second messenger conveys different information, mutants of the rat olfactory cyclic nucleotide-gated (CNG) channel alpha-subunit CNGA2, encoded into adenoviruses, were used to monitor cAMP in adult rat ventricular myocytes. CNGA2 was not found in native myocytes but was strongly expressed in infected cells. In whole cell patch-clamp experiments, the forskolin analogue L-858051 (L-85) elicited a non-selective, Mg2+ -sensitive current observed only in infected cells, which was thus identified as the CNG current (ICNG). The beta-adrenergic agonist isoprenaline (ISO) also activated ICNG, although the maximal efficiency was approximately 5 times lower than with L-85. However, ISO and L-85 exerted a similar maximal increase of the L-type Ca2+ current. The use of a CNGA2 mutant with a higher sensitivity for cAMP indicated that this difference is caused by the activation of a localized fraction of CNG channels by ISO. cAMP-dependent protein kinase (PKA) blockade with H89 or PKI, or phosphodiesterase (PDE) inhibition with IBMX, dramatically potentiated ISO- and L-85-stimulated ICNG. A similar potentiation of beta-adrenergic stimulation occurred when PDE4 was blocked, whereas PDE3 inhibition had a smaller effect (by 2-fold). ISO and L-85 increased total PDE3 and PDE4 activities in cardiomyocytes, although this effect was insensitive to H89. However, in the presence of IBMX, H89 had no effect on ISO stimulation of ICNG. This study demonstrates that subsarcolemmal cAMP levels are dynamically regulated by a negative feedback involving PKA stimulation of subsarcolemmal cAMP-PDE.

Study of the relationship between the aerobic capacity (VO2 max) and the rating of perceived exertion based on the measurement of heart beat in the metal industries Esfahan

PubMed Central

Habibi, Ehsanollah; Dehghan, Habibollah; Moghiseh, Mohammad; Hasanzadeh, Akbar

2014-01-01

Background and Objective: To establish a balance between work (physical exercise) and human beings, the aerobic capacity (VO2 max) could be used as a measure. Additionally, the subjective and physiological assessment could be applied as one of the methods for assessing physical exercise. The most commonly used tools for the assessment of fatigue during physical exercise include the Borg scale Rating of perceived Exertion (RPE) in relation to subjective symptoms and heart rate (HR) in relation to physiological symptoms. The study is aimed to investigate the relationship between the aerobic capacity and the RPE based on the measurement of heat rate (HR) of workers from the Metal Industries of Isfahan. Materials and Methods: The subjects were 200 male workers from metal components manufacturers in Isfahan selected by using random sampling based on statistic method. The subjects were examined by using ergometer in accordance with A strand 6 minutes cycle test protocol. Furthermore, the subjects were asked to rate their status based on the Borg rating scale at the end of each minute. Additionally, their heat rates were monitored and recorded automatically at the end of each minutes. Results: Statistical analysis showed that there was a significant relationship between the RPE and the aerobic capacity (VO2 max) (r = –0.904, P < 0.05). The results illustrated that there was a stronger correlation between HR and VO2 max (r = 0.991, P < 0.001). The regression analysis of the quadratic equation also indicated that there was also a significant relationship between the VO2 max and HR. Conclusions: The results indicated that there was a strong relationship between the RPE and VO2 max, as well as a greater correlation between HR and VO2 max. Therefore, the HR could be used as a Prediction measure to estimate VO2 max. PMID:25077148

EGFR ligands exert diverging effects on male reproductive organs.

PubMed

Schneider, Marlon R; Gratao, Ana A; Dahlhoff, Maik; Boersma, Auke; Hrabé de Angelis, Martin; Hoang-Vu, Cuong; Wolf, Eckhard; Klonisch, Thomas

2010-02-01

While the EGFR and most of its ligands are expressed in the male reproductive tract, their functions in male reproduction are poorly understood. Interestingly, male transgenic mice overexpressing EGF are sterile, and transgenic mice overexpressing TGFA, another EGFR ligand, show an enlarged coagulation gland (anterior prostate) due to severe hyperplasia with focal dysplasia. We studied the male reproductive tract of transgenic mice overexpressing betacellulin (BTC-tg) under the control of a promoter conferring widespread transgene expression. Despite strong overexpression of BTC in different parts of the male reproductive tract, the gross appearance and histology of the reproductive organs of BTC-tg males were normal and the same were true for sperm parameters and the in vitro fertilization rate. Collectively, our findings demonstrate that excess of BTC exerts no deleterious effects on the structure or function of the male reproductive tract in mice and indicates unique, non-overlapping functions of specific EGFR ligands in male reproduction. Copyright 2009 Elsevier Inc. All rights reserved.

Statistical testing of the full-range leadership theory in nursing.

PubMed

Kanste, Outi; Kääriäinen, Maria; Kyngäs, Helvi

2009-12-01

The aim of this study is to test statistically the structure of the full-range leadership theory in nursing. The data were gathered by postal questionnaires from nurses and nurse leaders working in healthcare organizations in Finland. A follow-up study was performed 1 year later. The sample consisted of 601 nurses and nurse leaders, and the follow-up study had 78 respondents. Theory was tested through structural equation modelling, standard regression analysis and two-way anova. Rewarding transformational leadership seems to promote and passive laissez-faire leadership to reduce willingness to exert extra effort, perceptions of leader effectiveness and satisfaction with the leader. Active management-by-exception seems to reduce willingness to exert extra effort and perception of leader effectiveness. Rewarding transformational leadership remained as a strong explanatory factor of all outcome variables measured 1 year later. The data supported the main structure of the full-range leadership theory, lending support to the universal nature of the theory.

The Scope of Our Affective Influences: When and How Naturally Occurring Positive, Negative, and Neutral Affects Alter Judgment.

PubMed

Gasper, Karen; Danube, Cinnamon L

2016-03-01

To determine how naturally arising affect alters judgment, we examined whether (a) affective states exert a specific, rather than a general, influence on valenced-specific judgments; (b) neutral affect is associated with increased neutral judgments, independent of positive, negative, and ambivalent affects, and whether neutral judgments are associated with behavioral disengagement; and (c) the informational value of naturally arising states may be difficult to alter via salience and relevance manipulations. The results support several conclusions: (a) Affective states exerted a judgment-specific effect-positive affect was most strongly associated with positive judgments, negative affect with negative judgments, and neutral affect with neutral judgments. (b) Neutral affect influenced judgments, taking into account positive, negative, and ambivalent affects; and neutral judgments predicted behavioral disengagement. (c) With the exception of negative affect, naturally arising affective states typically influenced judgments regardless of their salience and relevance. © 2016 by the Society for Personality and Social Psychology, Inc.

H-Ras Exerts Opposing Effects on Type I Interferon Responses Depending on Its Activation Status.

PubMed

Chen, Guann-An; Lin, Yun-Ru; Chung, Hai-Ting; Hwang, Lih-Hwa

2017-01-01

Using shRNA high-throughput screening, we identified H-Ras as a regulator of antiviral activity, whose depletion could enhance Sindbis virus replication. Further analyses indicated that depletion of H-Ras results in a robust increase in vesicular stomatitis virus infection and a decrease in Sendai virus (SeV)-induced retinoic acid-inducible gene-I-like receptor (RLR) signaling. Interestingly, however, ectopic expression of wild-type H-Ras results in a biphasic mode of RLR signaling regulation: while low-level expression of H-Ras enhances SeV-induced RLR signaling, high-level expression of H-Ras significantly inhibits this signaling. The inhibitory effects correlate with the activation status of H-Ras. As a result, oncogenic H-Ras, H-RasV12, strongly inhibits SeV-induced IFN-β promoter activity and type I interferon signaling. Conversely, the positive effects exerted by H-Ras on RLR signaling are independent of its signaling activity, as a constitutively inactive form of H-Ras, H-RasN17, also positively regulates RLR signaling. Mechanistically, we demonstrate that depletion of H-Ras reduces the formation of MAVS-TNF receptor-associated factor 3 signaling complexes. These results reveal that the H-Ras protein plays a role in promoting MAVS signalosome assembly in the mitochondria, whereas oncogenic H-Ras exerts a negative effect on type I IFN responses.

Bull in a China Shop? General Curtis E. Lemay’s Military Advice to the President During the Cuban Missile Crisis

DTIC Science & Technology

2009-06-01

Recordings, Presidential Recordings, JFKL. Emphasis added. 4 intoned forcefully, “it’s going to lead right into war!” The general felt that any...invitation by the president for the service chiefs to comment on political factors, General LeMay spoke of the perceptions of American citizens and...suggest experiences strongly shape perceptions , and past events are most influential when experiences are firsthand, exert direct influence, and are

Isolation and biological evaluation of jatrophane diterpenoids from Euphorbia dendroides.

PubMed

Aljancić, Ivana S; Pesić, Milica; Milosavljević, Slobodan M; Todorović, Nina M; Jadranin, Milka; Milosavljević, Goran; Povrenović, Dragan; Banković, Jasna; Tanić, Nikola; Marković, Ivanka D; Ruzdijić, Sabera; Vajs, Vlatka E; Tesević, Vele V

2011-07-22

From the Montenegrin spurge Euphorbia dendroides, seven new diterpenoids [jatrophanes (1-6) and a tigliane (7)] were isolated and their structures elucidated by spectroscopic techniques. The biological activity of the new compounds was studied against four human cancer cell lines. The most effective jatrophane-type compound (2) and its structurally closely related derivative (1) were evaluated for their interactions with paclitaxel and doxorubicin using a multi-drug-resistant cancer cell line. Both compounds exerted a strong reversal potential resulting from inhibition of P-glycoprotein transport.

Discovery and structure-activity relationships of piperidinone- and piperidine-constrained phenethylamines as novel, potent, and selective dipeptidyl peptidase IV inhibitors.

PubMed

Pei, Zhonghua; Li, Xiaofeng; von Geldern, Thomas W; Longenecker, Kenton; Pireh, Daisy; Stewart, Kent D; Backes, Bradley J; Lai, Chunqiu; Lubben, Thomas H; Ballaron, Stephen J; Beno, David W A; Kempf-Grote, Anita J; Sham, Hing L; Trevillyan, James M

2007-04-19

Dipeptidyl peptidase IV (DPP4) inhibitors are emerging as a new class of therapeutic agents for the treatment of type 2 diabetes. They exert their beneficial effects by increasing the levels of active glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are two important incretins for glucose homeostasis. Starting from a high-throughput screening hit, we were able to identify a series of piperidinone- and piperidine-constrained phenethylamines as novel DPP4 inhibitors. Optimized compounds are potent, selective, and have good pharmacokinetic profiles.

Suspected myofibrillar myopathy in Arabian horses with a history of exertional rhabdomyolysis.

PubMed

Valberg, S J; McKenzie, E C; Eyrich, L V; Shivers, J; Barnes, N E; Finno, C J

2016-09-01

Although exertional rhabdomyolysis (ER) is common in Arabian horses, there are no dedicated studies describing histopathological characteristics of muscle from Arabian horses with ER. To prospectively identify distinctive histopathological features of muscle from Arabian endurance horses with a history of ER (pro-ER) and to retrospectively determine their prevalence in archived samples from Arabian horses with exertional myopathies (retro-ER). Prospective and retrospective histopathological description. Middle gluteal muscle biopsies obtained from Arabian controls (n = 14), pro-ER (n = 13) as well as archived retro-ER (n = 25) muscle samples previously classified with type 2 polysaccharide storage myopathy (15/25), recurrent exertional rhabdomyolysis (7/25) and no pathology (3/25) were scored for histopathology and immunohistochemical staining of cytoskeletal proteins. Glutaraldehyde-fixed samples (2 pro-ER, one control) were processed for electron microscopy. Pro-ER and retro-ER groups were compared with controls using Mann-Whitney U and Fisher's exact tests. Centrally located myonuclei in mature myofibres were found in significantly more (P<0.05) pro-ER (12/13) and retro-ER (21/25) horses than controls (4/14). Degenerating myofibres were not evident in any biopsies. Retro-ER horses had amylase-resistant polysaccharide (6/25, P<0.05) and higher scores for cytoplasmic glycogen, rimmed vacuoles and rod-like bodies. A few control horses (3/14) and significantly (P<0.05) more pro-ER (12/13) and retro-ER (18/25) horses had disrupted myofibrillar alignment and large desmin and αβ-crystallin positive cytoplasmic aggregates. Prominent Z-disc degeneration and focal myofibrillar disruption with regional accumulation of β-glycogen particles were identified on electron microscopy of the 2 pro-ER samples. In a subset of Arabian horses with intermittent episodes of exertional rhabdomyolysis, ectopic accumulation of cytoskeletal proteins and Z-disc degeneration bear a strong resemblance to a myofibrillar myopathy. While many of these horses were previously diagnosed with type 2 polysaccharide storage myopathy, pools of glycogen forming within disrupted myofibrils appeared to give the false appearance of a glycogen storage disorder. © 2015 EVJ Ltd.

Suspected myofibrillar myopathy in Arabian horses with a history of exertional rhabdomyolysis

PubMed Central

VALBERG, S. J.; McKENZIE, E. C.; EYRICH, L. V.; SHIVERS, J.; BARNES, N. E.; FINNO, C. J.

2016-01-01

Summary Reasons for performing study Although exertional rhabdomyolysis (ER) is common in Arabian horses, there are no dedicated studies describing histopathological characteristics of muscle from Arabian horses with ER. Objectives To prospectively identify distinctive histopathological features of muscle from Arabian endurance horses with a history of ER (pro-ER) and to retrospectively determine their prevalence in archived samples from Arabian horses with exertional myopathies (retro-ER). Study design Prospective and retrospective histopathological description. Methods Middle gluteal muscle biopsies obtained from Arabian controls (n = 14), pro-ER (n = 13) as well as archived retro-ER (n = 25) muscle samples previously classified with type 2 polysaccharide storage myopathy (15/25), recurrent exertional rhabdomyolysis (7/25) and no pathology (3/25) were scored for histopathology and immunohistochemical staining of cytoskeletal proteins. Glutaraldehyde-fixed samples (2 pro-ER, one control) were processed for electron microscopy. Pro-ER and retro-ER groups were compared with controls using Mann–Whitney U and Fisher's exact tests. Results Centrally located myonuclei in mature myofibres were found in significantly more (P<0.05) pro-ER (12/13) and retro-ER (21/25) horses than controls (4/14). Degenerating myofibres were not evident in any biopsies. Retro-ER horses had amylase-resistant polysaccharide (6/25, P<0.05) and higher scores for cytoplasmic glycogen, rimmed vacuoles and rod-like bodies. A few control horses (3/14) and significantly (P<0.05) more pro-ER (12/13) and retro-ER (18/25) horses had disrupted myofibrillar alignment and large desmin and αβ-crystallin positive cytoplasmic aggregates. Prominent Z-disc degeneration and focal myofibrillar disruption with regional accumulation of β-glycogen particles were identified on electron microscopy of the 2 pro-ER samples. Conclusions In a subset of Arabian horses with intermittent episodes of exertional rhabdomyolysis, ectopic accumulation of cytoskeletal proteins and Z-disc degeneration bear a strong resemblance to a myofibrillar myopathy. While many of these horses were previously diagnosed with type 2 polysaccharide storage myopathy, pools of glycogen forming within disrupted myofibrils appeared to give the false appearance of a glycogen storage disorder. PMID:26234161

Bronchodilatation by tachykinins and capsaicin in the mouse main bronchus.

PubMed

Manzini, S

1992-04-01

1. The effect of sensory neuropeptides and capsaicin on basal and stimulated tone of mouse bronchial smooth muscle has been evaluated. 2. In basal conditions neither sensory neuropeptides (substance P, neurokinin A or calcitonin gene-related peptide (CGRP) nor capsaicin exerted any contractile effects. However, when a tonic contraction was induced with carbachol (1 microM) a prompt relaxation was induced by substance P (1- 100 nM) and by neurokinin A (1- 100 nM), with substance P being more potent. A second application of substance P was without effect. CGRP (10 nM) produced only a very small and erratic relaxation. Relaxation was also induced by capsaicin (1 microM), and this response could be evoked only once in each preparation. In 4 out of 6 preparations a cross-desensitization between substance P and capsaicin was observed. 3. The selective NK1 tachykinin agonist, [Pro9]-SP sulphone (1 microM), exerted potent bronchodilator actions on carbachol-contracted mouse bronchial preparations. In contrast, neither [beta Ala8]-NKA (4-10) nor [MePhe7]-NKB (both at a concentration of 1 microM), selective synthetic agonists for NK2 and NK3 receptors, exerted significant relaxant effects. Furthermore, the selective NK1 tachykinin antagonist, (+/-)-CP 96,345 (1 microM), abolished substance P (1 nM)- but not isoprenaline (0.1 microM)-induced relaxations. 4. Application of electrical field stimulation (EFS) (20 Hz, supramaximal voltage, 0.5 ms for 10 s) to carbachol-contracted preparations evoked a transient contraction followed by a relaxation. The tetrodotoxin-sensitive slow component of this relaxation was reduced following capsaicin desensitization. 5. In the presence of indomethacin (5 microM) the relaxation induced by substance P, capsaicin or EFS was suppressed.6. In conclusion, the mouse main bronchus appears to be a monoreceptorial tissue containing only NK, receptors which subserve bronchodilator functions. Such receptors could be activated by exogenous or endogenously (capsaicin or EFS) released tachykinins and the consequent relaxation is probably mediated by the generation of prostanoids.

Variation in reward quality and pollinator attraction: the consumer does not always get it right.

PubMed

Carr, David E; Haber, Ariela I; LeCroy, Kathryn A; Lee, De'Ashia E; Link, Rosabeth I

2015-04-09

Nearly all bees rely on pollen as the sole protein source for the development of their larvae. The central importance of pollen for the bee life cycle should exert strong selection on their ability to locate the most rewarding sources of pollen. Despite this importance, very few studies have examined the influence of intraspecific variation in pollen rewards on the foraging decisions of bees. Previous studies have demonstrated that inbreeding reduces viability and hence protein content in Mimulus guttatus (seep monkeyflower) pollen and that bees strongly discriminate against inbred in favour of outbred plants. We examined whether variation in pollen viability could explain this preference using a series of choice tests with living plants, artificial plants and olfactometer tests using the bumble bee Bombus impatiens. We found that B. impatiens preferred to visit artificial plants provisioned with fertile anthers over those provisioned with sterile anthers. They also preferred fertile anthers when provided only olfactory cues. These bumble bees were unable to discriminate among live plants from subpopulations differing dramatically in pollen viability, however. They preferred outbred plants even when those plants were from subpopulations with pollen viability as low as the inbred populations. Their preference for outbred plants was evident even when only olfactory cues were available. Our data showed that bumble bees are able to differentiate between anthers that provide higher rewards when cues are isolated from the rest of the flower. When confronted with cues from the entire flower, their choices are independent of the quality of the pollen reward, suggesting that they are responding more strongly to cues unassociated with rewards than to those correlated with rewards. If so, this suggests that a sensory bias or some level of deception may be involved with advertisement to pollinators in M. guttatus. Published by Oxford University Press on behalf of the Annals of Botany Company.

Reciprocal selection causes a coevolutionary arms race between crossbills and lodgepole pine.

PubMed

Benkman, Craig W; Parchman, Thomas L; Favis, Amanda; Siepielski, Adam M

2003-08-01

Few studies have shown both reciprocal selection and reciprocal adaptations for a coevolving system in the wild. The goal of our study was to determine whether the patterns of selection on Rocky Mountain lodgepole pine (Pinus contorta spp. latifolia) and red crossbills (Loxia curvirostra complex) were concordant with earlier published evidence of reciprocal adaptations in lodgepole pine and crossbills on isolated mountain ranges in the absence of red squirrels (Tamiasciurus hudsonicus). We found that selection (directional) by crossbills on lodgepole pine where Tamiasciurus are absent was divergent from the selection (directional) exerted by Tamiasciurus on lodgepole pine. This resulted in divergent selection between areas with and without Tamiasciurus that was congruent with the geographic patterns of cone variation. In the South Hills, Idaho, where Tamiasciurus are absent and red crossbills are thought to be coevolving with lodgepole pine, crossbills experienced stabilizing selection on bill size, with cone structure as the agent of selection. These results show that crossbills and lodgepole pine exhibit reciprocal adaptations in response to reciprocal selection, and they provide insight into the traits mediating and responding to selection in a coevolutionary arms race.

FOXM1: A novel drug target in gastroenteropancreatic neuroendocrine tumors

PubMed Central

Briest, Franziska; Berg, Erika; Grass, Irina; Freitag, Helma; Kaemmerer, Daniel; Lewens, Florentine; Christen, Friederike; Arsenic, Ruza; Altendorf-Hofmann, Annelore; Kunze, Almut; Sänger, Jörg; Knösel, Thomas; Siegmund, Britta; Hummel, Michael; Grabowski, Patricia

2015-01-01

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are heterogeneous tumors that need to be molecularly defined to obtain novel therapeutic options. Forkheadbox protein M1 (FOXM1) is a crucial transcription factor in neoplastic cells and has been associated with differentiation and proliferation. We found that FOXM1 is strongly associated with tumor differentiation and occurrence of metastases in gastrointestinal NENs. In vitro inhibition by the FOXM1 inhibitor siomycin A led to down-regulation of mitotic proteins and resulted in a strong inhibitory effect. Siomycin A decreased mitosis rate, induced apoptosis in GEP-NEN cell lines and exerts synergistic effects with chemotherapy. FOXM1 is associated with clinical outcome and FOXM1 inhibition impairs survival in vitro. We therefore propose FOXM1 as novel therapeutic target in GEP-NENs. PMID:25797272

Investigating the Consequences of Interference between Multiple CD8+ T Cell Escape Mutations in Early HIV Infection

PubMed Central

Garcia, Victor; Feldman, Marcus W.; Regoes, Roland R.

2016-01-01

During early human immunodeficiency virus (HIV) infection multiple CD8+ T cell responses are elicited almost simultaneously. These responses exert strong selective pressures on different parts of HIV’s genome, and select for mutations that escape recognition and are thus beneficial to the virus. Some studies reveal that the later these escape mutations emerge, the more slowly they go to fixation. This pattern of escape rate decrease(ERD) can arise by distinct mechanisms. In particular, in large populations with high beneficial mutation rates interference among different escape strains –an effect that can emerge in evolution with asexual reproduction and results in delayed fixation times of beneficial mutations compared to sexual reproduction– could significantly impact the escape rates of mutations. In this paper, we investigated how interference between these concurrent escape mutations affects their escape rates in systems with multiple epitopes, and whether it could be a source of the ERD pattern. To address these issues, we developed a multilocus Wright-Fisher model of HIV dynamics with selection, mutation and recombination, serving as a null-model for interference. We also derived an interference-free null model assuming initial neutral evolution before immune response elicitation. We found that interference between several equally selectively advantageous mutations can generate the observed ERD pattern. We also found that the number of loci, as well as recombination rates substantially affect ERD. These effects can be explained by the underexponential decline of escape rates over time. Lastly, we found that the observed ERD pattern in HIV infected individuals is consistent with both independent, interference-free mutations as well as interference effects. Our results confirm that interference effects should be considered when analyzing HIV escape mutations. The challenge in estimating escape rates and mutation-associated selective coefficients posed by interference effects cannot simply be overcome by improved sampling frequencies or sizes. This problem is a consequence of the fundamental shortcomings of current estimation techniques under interference regimes. Hence, accounting for the stochastic nature of competition between mutations demands novel estimation methodologies based on the analysis of HIV strains, rather than mutation frequencies. PMID:26829720

Antibiotic-resistant bacteria: a challenge for the food industry.

PubMed

Capita, Rosa; Alonso-Calleja, Carlos

2013-01-01

Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.

The Influence of Workers' Health Status on Employers' Decision-Making During Personnel Restructuring in a Typical Public Limited Enterprise in Slovenia.

PubMed

Margan, Andrea; Dodič-Fikfak, Metoda

2015-09-01

Alongside individual indicators of job performance, even workers' health status could be a criterion for selection. The mechanisms for health selection are a reduction of productivity in relation to illness or certain health behaviour. The aim of the study was to establish how indicators of workers' health status, which are accessible to the employer, influence the employer's decision-making on which workers to retain and which to dismiss during personnel restructuring in the enterprise. Due to a planned closure of a plant, the observed company began personnel restructuring which included a strategic decrease in the number of employees and the relocation of workers within the company. Two nested case control studies were conducted. The cases were divided into two groups and defined as follows: employees who were relocated and employees whose employment contract was terminated. The results show that the disability category and long-time sick leave exert the greatest influence on the employer's decision on the selection of workers. Workers with work-related disability have lower odds to be relocated to a new workplace (OR=0.5; 95% CI 0.2 to 1.1) and higher odds to be dismissed (OR=6.51; 95% CI 3.33 to 12.72). The workers with a history of a long-time sick leave also have lower odds to be relocated (OR=0.31; 95% CI 0.11 to 0.88) and higher odds to be dismissed (OR=4.32; 95% CI 2.08 to 8.96). Indicators of health which were accessible to the employer actually exerted influence on the employer's decision-making, which could show a direct form of health selection.

Application of Rhizobacteria for Plant Growth Promotion Effect and Biocontrol of Anthracnose Caused by Colletotrichum acutatum on Pepper

PubMed Central

Lamsal, Kabir; Kim, Sang Woo; Kim, Yun Seok

2012-01-01

In vitro and greenhouse screening of seven rhizobacterial isolates, AB05, AB10, AB11, AB12, AB14, AB15 and AB17, was conducted to investigate the plant growth promoting activities and inhibition against anthracnose caused by Colletotrichum acutatum in pepper. According to identification based on 16S rDNA sequencing, the majority of the isolates are members of Bacillus and a single isolate belongs to the genus Paenibacillus. All seven bacterial isolates were capable of inhibiting C. acutatum to various degrees. The results primarily showed that antibiotic substances produced by the selected bacteria were effective and resulted in strong antifungal activity against the fungi. However, isolate AB15 was the most effective bacterial strain, with the potential to suppress more than 50% mycelial growth of C. acutatum in vitro. Moreover, antibiotics from Paenibacillus polymyxa (AB15) and volatile compounds from Bacillus subtilis (AB14) exerted efficient antagonistic activity against the pathogens in a dual culture assay. In vivo suppression activity of selected bacteria was also analyzed in a greenhouse with the reference to their prominent in vitro antagonism efficacy. Induced systemic resistance in pepper against C. acutatum was also observed under greenhouse conditions. Where, isolate AB15 was found to be the most effective bacterial strain at suppressing pepper anthracnose under greenhouse conditions. Moreover, four isolates, AB10, AB12, AB15, and AB17, were identified as the most effective growth promoting bacteria under greenhouse conditions, with AB17 inducing the greatest enhancement of pepper growth. PMID:23323049

Metformin selectively affects human glioblastoma tumor-initiating cell viability

PubMed Central

Würth, Roberto; Pattarozzi, Alessandra; Gatti, Monica; Bajetto, Adirana; Corsaro, Alessandro; Parodi, Alessia; Sirito, Rodolfo; Massollo, Michela; Marini, Cecilia; Zona, Gianluigi; Fenoglio, Daniela; Sambuceti, Gianmario; Filaci, Gilberto; Daga, Antonio; Barbieri, Federica; Florio, Tullio

2013-01-01

Cancer stem cell theory postulates that a small population of tumor-initiating cells is responsible for the development, progression and recurrence of several malignancies, including glioblastoma. In this perspective, tumor-initiating cells represent the most relevant target to obtain effective cancer treatment. Metformin, a first-line drug for type II diabetes, was reported to possess anticancer properties affecting the survival of cancer stem cells in breast cancer models. We report that metformin treatment reduced the proliferation rate of tumor-initiating cell-enriched cultures isolated from four human glioblastomas. Metformin also impairs tumor-initiating cell spherogenesis, indicating a direct effect on self-renewal mechanisms. Interestingly, analyzing by FACS the antiproliferative effects of metformin on CD133-expressing subpopulation, a component of glioblastoma cancer stem cells, a higher reduction of proliferation was observed as compared with CD133-negative cells, suggesting a certain degree of cancer stem cell selectivity in its effects. In fact, glioblastoma cell differentiation strongly reduced sensitivity to metformin treatment. Metformin effects in tumor-initiating cell-enriched cultures were associated with a powerful inhibition of Akt-dependent cell survival pathway, while this pathway was not affected in differentiated cells. The specificity of metformin antiproliferative effects toward glioblastoma tumor-initiating cells was confirmed by the lack of significant inhibition of normal human stem cells (umbilical cord-derived mesenchymal stem cells) in vitro proliferation after metformin exposure. Altogether, these data clearly suggest that metformin exerts antiproliferative activity on glioblastoma cells, showing a higher specificity toward tumor-initiating cells, and that the inhibition of Akt pathway may represent a possible intracellular target of this effect. PMID:23255107

Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

PubMed Central

Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Hélène Desmonts, Marie; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

2015-01-01

The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota. PMID:25333463

Phenformin enhances the therapeutic benefit of BRAFV600E inhibition in melanoma

PubMed Central

Yuan, Ping; Ito, Koichi; Perez-Lorenzo, Rolando; Del Guzzo, Christina; Lee, Jung Hyun; Shen, Che-Hung; Bosenberg, Marcus W.; McMahon, Martin; Cantley, Lewis C.; Zheng, Bin

2013-01-01

Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated antitumor activity both in vitro and in vivo. The energy-sensing AMP-activated protein kinase (AMPK) is known to be a major cellular target of biguanides. Based on our discovery of cross-talk between the AMPK and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) signaling pathways, we investigated the antitumor effects of combining phenformin with a BRAF inhibitor PLX4720 on the proliferation of BRAF-mutated melanoma cells in vitro and on BRAF-driven tumor growth in vivo. Cotreatment of BRAF-mutated melanoma cell lines with phenformin and PLX4720 resulted in synergistic inhibition of cell viability, compared with the effects of the single agent alone. Moreover, treatment with phenformin significantly delayed the development of resistance to PLX4720 in cultured melanoma cells. Biochemical analyses showed that phenformin and PLX4720 exerted cooperative effects on inhibiting mTOR signaling and inducing apoptosis. Noticeably, phenformin selectively targeted subpopulations of cells expressing JARID1B, a marker for slow cycling melanoma cells, whereas PLX4720 selectively targeted JARID1B-negative cells. Finally, in contrast to their use as single agents, the combination of phenformin and PLX4720 induced tumor regression in both nude mice bearing melanoma xenografts and in a genetically engineered BRAFV600E/PTENnull-driven mouse model of melanoma. These results strongly suggest that significant therapeutic advantage may be achieved by combining AMPK activators such as phenformin with BRAF inhbitors for the treatment of melanoma. PMID:24145418

Phenformin enhances the therapeutic benefit of BRAF(V600E) inhibition in melanoma.

PubMed

Yuan, Ping; Ito, Koichi; Perez-Lorenzo, Rolando; Del Guzzo, Christina; Lee, Jung Hyun; Shen, Che-Hung; Bosenberg, Marcus W; McMahon, Martin; Cantley, Lewis C; Zheng, Bin

2013-11-05

Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated antitumor activity both in vitro and in vivo. The energy-sensing AMP-activated protein kinase (AMPK) is known to be a major cellular target of biguanides. Based on our discovery of cross-talk between the AMPK and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) signaling pathways, we investigated the antitumor effects of combining phenformin with a BRAF inhibitor PLX4720 on the proliferation of BRAF-mutated melanoma cells in vitro and on BRAF-driven tumor growth in vivo. Cotreatment of BRAF-mutated melanoma cell lines with phenformin and PLX4720 resulted in synergistic inhibition of cell viability, compared with the effects of the single agent alone. Moreover, treatment with phenformin significantly delayed the development of resistance to PLX4720 in cultured melanoma cells. Biochemical analyses showed that phenformin and PLX4720 exerted cooperative effects on inhibiting mTOR signaling and inducing apoptosis. Noticeably, phenformin selectively targeted subpopulations of cells expressing JARID1B, a marker for slow cycling melanoma cells, whereas PLX4720 selectively targeted JARID1B-negative cells. Finally, in contrast to their use as single agents, the combination of phenformin and PLX4720 induced tumor regression in both nude mice bearing melanoma xenografts and in a genetically engineered BRAF(V600E)/PTEN(null)-driven mouse model of melanoma. These results strongly suggest that significant therapeutic advantage may be achieved by combining AMPK activators such as phenformin with BRAF inhbitors for the treatment of melanoma.

Evolution and cell physiology. 2. The evolution of cell signaling: from mitochondria to Metazoa.

PubMed

Blackstone, Neil W

2013-11-01

The history of life is a history of levels-of-selection transitions. Each transition requires mechanisms that mediate conflict among the lower-level units. In the origins of multicellular eukaryotes, cell signaling is one such mechanism. The roots of cell signaling, however, may extend to the previous major transition, the origin of eukaryotes. Energy-converting protomitochondria within a larger cell allowed eukaryotes to transcend the surface-to-volume constraints inherent in the design of prokaryotes. At the same time, however, protomitochondria can selfishly allocate energy to their own replication. Metabolic signaling may have mediated this principal conflict in several ways. Variation of the protomitochondria was constrained by stoichiometry and strong metabolic demand (state 3) exerted by the protoeukaryote. Variation among protoeukaryotes was increased by the sexual stage of the life cycle, triggered by weak metabolic demand (state 4), resulting in stochastic allocation of protomitochondria to daughter cells. Coupled with selection, many selfish protomitochondria could thus be removed from the population. Hence, regulation of states 3 and 4, as, for instance, provided by the CO2/soluble adenylyl cyclase/cAMP pathway in mitochondria, was critical for conflict mediation. Subsequently, as multicellular eukaryotes evolved, metabolic signaling pathways employed by eukaryotes to mediate conflict within cells could now be co-opted into conflict mediation between cells. For example, in some fungi, the CO2/soluble adenylyl cyclase/cAMP pathway regulates the transition from yeast to forms with hyphae. In animals, this pathway regulates the maturation of sperm. While the particular features (sperm and hyphae) are distinct, both may involve between-cell conflicts that required mediation.

Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage.

PubMed

Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Desmonts, Marie Hélène; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

2015-05-01

The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota.

Psychological stress exerts an adjuvant effect on skin dendritic cell functions in vivo.

PubMed

Saint-Mezard, Pierre; Chavagnac, Cyril; Bosset, Sophie; Ionescu, Marius; Peyron, Eric; Kaiserlian, Dominique; Nicolas, Jean-Francois; Bérard, Frédéric

2003-10-15

Psychological stress affects the pathophysiology of infectious, inflammatory, and autoimmune diseases. However, the mechanisms by which stress could modulate immune responses in vivo are poorly understood. In this study, we report that application of a psychological stress before immunization exerts an adjuvant effect on dendritic cell (DC), resulting in increased primary and memory Ag-specific T cell immune responses. Acute stress dramatically enhanced the skin delayed-type hypersensitivity reaction to haptens, which is mediated by CD8(+) CTLs. This effect was due to increased migration of skin DCs, resulting in augmented CD8(+) T cell priming in draining lymph nodes and enhanced recruitment of CD8(+) T cell effectors in the skin upon challenge. This adjuvant effect of stress was mediated by norepinephrine (NE), but not corticosteroids, as demonstrated by normalization of the skin delayed-type hypersensitivity reaction and DC migratory properties following selective depletion of NE. These results suggest that release of NE by sympathetic nerve termini during a psychological stress exerts an adjuvant effect on DC by promoting enhanced migration to lymph nodes, resulting in increased Ag-specific T cell responses. Our findings may open new ways in the treatment of inflammatory diseases, e.g., psoriasis, allergic contact dermatitis, and atopic dermatitis.

Human behavioral thermoregulation during exercise in the heat.

PubMed

Flouris, A D; Schlader, Z J

2015-06-01

The human capacity to perform prolonged exercise is impaired in hot environments. To address this issue, a number of studies have investigated behavioral aspects of thermoregulation that are recognized as important factors in determining performance. In this review, we evaluated and interpreted the available knowledge regarding the voluntary control of exercise work rate in hot environments. Our analysis indicated that: (a) Voluntary reductions in exercise work rate in uncompensable heat aid thermoregulation and are, therefore, thermoregulatory behaviors. (b) Unlike thermal behavior during rest, the role of thermal comfort as the ultimate mediator of thermal behavior during exercise in the heat remains uncertain. By contrast, the rating of perceived exertion appears to be the key perceptual controller under such conditions, with thermal perception playing a more modulatory role. (c) Prior to increases in core temperature (when only skin temperature is elevated), reductions in self-selected exercise work rate in the heat are likely mediated by thermal perception (thermal comfort and sensation) and its influence on the rating of perceived exertion. (d) However, when both core and skin temperatures are elevated, factors associated with cardiovascular strain likely dictate the rate of perceived exertion response, thereby mediating such voluntary reductions in exercise work rate. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Power production by Olympic weightlifters.

PubMed

Garhammer, J

1980-01-01

A new procedure was developed for calculating power production during Olympic lifting movements and comparisons were made with a method previously used. The power output of seven superior lifters was determined during selected phases of the snatch, clean, and jerk, from films taken at the 1975 U.S. National Championships. The values obtained depended on the following variables: vertical change in the bar's mechanical energy from the beginning of a force exertion phase until maximum vertical bar velocity was achieved; work done by the athlete in producing horizontal bar movement; and work done in raising the body's center of gravity. Results showed the expected increase in power with increased bodyweight for a given movement. Values for the jerk drive ranged from 2140 watts in the 56 kg class to 4786 watts for a 110 kg lifter. Heavier lifters exceeded published maximal estimates for human power output during brief exertions. More significant was the high degree of consistency in the rate of work done by any given lifter in movements which were very similar with respect to joint action, but competitively had very different objectives. The procedure should prove useful in detecting problems in lifting movements that result in power outputs which are low relative to those measured for biomechanically equivalent exertions.

[Factors Influencing Musculoskeletal Symptoms in Military Personnel during Basic Combat Training].

PubMed

Yi, Jeong Min; Kim, Gwang Suk

2016-08-01

This study was done to examine physical, psycho-social, and individual factors influencing musculoskeletal symptoms among Korean military trainees. Using a correlation study design, military trainees who had completed almost of all the basic combat training (BCT) days were recruited from two military training units selected by convenience sampling. Data from 415 participants were analyzed. Prevalence of musculoskeletal symptoms was 29.6% defined as a participant having pain or discomfort in one or more body parts during training hours for more than seven consecutive days. Back/pelvic (10.8%), knees (10.1%), shoulders (7.7%), feet/toes (5.6%), ankles (4.8%) were prone to musculoskeletal symptoms. Musculoskeletal symptoms appeared to be related to physical exertion during BCT, stress during BCT, social support from fellow trainees, or previous musculoskeletal injuries. In the logistic regression model, physical exertion during BCT (OR=2.27, 95% CI: 1.42~3.65), stress during BCT (OR=1.79, 95% CI: 1.15~2.78), and previous musculoskeletal injuries (OR=1.58, 95% CI: 1.01~2.47) were the significant factors affecting prevalence of musculoskeletal symptoms. Findings indicate that physical exertion and psycho-social stress should be managed to prevent musculoskeletal symptoms in military trainees with more attention being given to trainees having a history of musculoskeletal injuries.

Exploring the Effects on Lipid Bilayer Induced by Noble Gases via Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Chen, Junlang; Chen, Liang; Wang, Yu; Wang, Xiaogang; Zeng, Songwei

2015-11-01

Noble gases seem to have no significant effect on the anesthetic targets due to their simple, spherical shape. However, xenon has strong narcotic efficacy and can be used clinically, while other noble gases cannot. The mechanism remains unclear. Here, we performed molecular dynamics simulations on phospholipid bilayers with four kinds of noble gases to elucidate the difference of their effects on the membrane. Our results showed that the sequence of effects on membrane exerted by noble gases from weak to strong was Ne, Ar, Kr and Xe, the same order as their relative narcotic potencies as well as their lipid/water partition percentages. Compared with the other three kinds of noble gases, more xenon molecules were distributed between the lipid tails and headgroups, resulting in membrane’s lateral expansion and lipid tail disorder. It may contribute to xenon’s strong anesthetic potency. The results are well consistent with the membrane mediated mechanism of general anesthesia.

The impact of clinical, psychological, behavioral, social, and environmental factors on self-perceived symptom severity in a male cohort with intermittent claudication.

PubMed

Sharath, Sherene E; Kougias, Panos; Pisimisis, George; Barshes, Neal R

2016-05-01

To understand the relationship between self-perceived severity of intermittent claudication and various associated nonclinical factors, we examined how correlates in domains of physical activity (ie, clinical, psychological, behavioral, social, and environmental factors) relate to exertional limb symptoms. A survey was administered to individuals with intermittent claudication during their initial outpatient assessment. The subjects' self-reported exertional limb symptom severity and classic-versus-atypical claudication classification was based on the Walking Impairment Questionnaire (WIQ) and San Diego Claudication Questionnaire (SDCQ), respectively. We evaluated psychosocial and environmental factors, osteoarthritis symptoms, health, behaviors, and beliefs. Logistic and linear regressions identified factors with a strong independent association with total WIQ scores and the SDCQs. A cohort of 102 subjects (99.0% male) was enrolled in the study. The median age was 65 years with a median ankle-brachial index of 0.69. Forty-three subjects (43%) had "typical" claudication per SDCQs. Individuals with atypical claudication were more likely to report higher Aberdeen Clinical Back Pain Questionnaire scores (odds ratio, 1.04; P = .04) and no depressive symptoms (odds ratio, 8.30; P = .03). Exertional limb symptom severity among the entire cohort was significantly associated with increasing osteoarthritis symptoms (P <.001), age (P = .02), a reserved personality (P = .008), and the belief that an exercise regimen would not improve symptoms (P = .005), self-perceived levels of boredom (P = .002), and the belief that exercise (P = .002) was the best way to improve symptoms were associated with decreased symptom severity. When restricted to those with atypical pain, significant factors associated with increasing exertional symptom severity included age greater than 60 years (P = .005), osteoarthritis (P = .02), alcohol use (P = .01), belief that exercise would not improve walking (P = .03), and difficulty walking around the neighborhood (P = .02). When restricted to those with classic claudication, significant factors associated with increasing exertional limb symptom severity included frequent pain or aching in the calves while walking or sitting (P = .03 [walking]; P = .01 [sitting]) and occasional morning joint stiffness (P = .007). Exertional limb symptom severity was also associated with high limitations at home (P = .003) and a belief that exercise would not improve walking (P = .005) among those with classic claudication. Symptom severity and type of pain are associated with a number of nonclinical factors. A multidomain approach, as indicated by the models above, would benefit the continuum of care for intermittent claudication, where management is integrated and coordinated among multiple lines of care. Published by Elsevier Inc.

Economic Influences on Re-Enlistment. The Draft Era.

DTIC Science & Technology

1982-10-01

for each individual in jobs covered by Social Security (over 90 percent of all private - sector jobs, plus military service and half of non-federal...disappeared as real military wages have increased significantly over cyclical swings in the private sector . Despite the Navy’s apparent success in...maintaining optimal retention rates in selective ratings is due to the wage pressures exerted in the private sector . Military wage increases must be

PDE4 as a target for cognition enhancement

PubMed Central

Richter, Wito; Menniti, Frank S.; Zhang, Han-Ting; Conti, Marco

2014-01-01

Introduction The second messengers cAMP and cGMP mediate fundamental aspects of brain function relevant to memory, learning and cognitive functions. Consequently, cyclic nucleotide phosphodiesterases (PDEs), the enzymes that inactivate the cyclic nucleotides, are promising targets for the development of cognition-enhancing drugs. Areas covered PDE4 is the largest of the eleven mammalian PDE families. This review covers the properties and functions of the PDE4 family, highlighting procognitive and memory-enhancing effects associated with their inactivation. Expert opinion PAN-selective PDE4 inhibitors exert a number of memory- and cognition-enhancing effects and have neuroprotective and neuroregenerative properties in preclinical models. The major hurdle for their clinical application is to target inhibitors to specific PDE4 isoforms relevant to particular cognitive disorders to realize the therapeutic potential while avoiding side effects, in particular emesis and nausea. The PDE4 family comprises four genes, PDE4A-D, each expressed as multiple variants. Progress to date stems from characterization of rodent models with selective ablation of individual PDE4 subtypes, revealing that individual subtypes exert unique and non-redundant functions in the brain. Thus, targeting specific PDE4 subtypes, as well as splicing variants or conformational states, represents a promising strategy to separate the therapeutic benefits from the side effects of PAN-PDE4 inhibitors. PMID:23883342

Insights into the anticancer properties of the first antimicrobial peptide from Archaea.

PubMed

Gaglione, Rosa; Pirone, Luciano; Farina, Biancamaria; Fusco, Salvatore; Smaldone, Giovanni; Aulitto, Martina; Dell'Olmo, Eliana; Roscetto, Emanuela; Del Gatto, Annarita; Fattorusso, Roberto; Notomista, Eugenio; Zaccaro, Laura; Arciello, Angela; Pedone, Emilia; Contursi, Patrizia

2017-09-01

The peptide VLL-28, identified in the sequence of an archaeal protein, the transcription factor Stf76 from Sulfolobus islandicus, was previously identified and characterized as an antimicrobial peptide, possessing a broad-spectrum antibacterial activity. Through a combined approach of NMR and Circular Dichroism spectroscopy, Dynamic Light Scattering, confocal microscopy and cell viability assays, the interaction of VLL-28 with the membranes of both parental and malignant cell lines has been characterized and peptide mechanism of action has been studied. It is here demonstrated that VLL-28 selectively exerts cytotoxic activity against murine and human tumor cells. By means of structural methodologies, VLL-28 interaction with the membranes has been proven and the binding residues have been identified. Confocal microscopy data show that VLL-28 is internalized only into tumor cells. Finally, it is shown that cell death is mainly caused by a time-dependent activation of apoptotic pathways. VLL-28, deriving from the archaeal kingdom, is here found to be endowed with selective cytotoxic activity towards both murine and human cancer cells and consequently can be classified as an ACP. VLL-28 represents the first ACP identified in an archaeal microorganism, exerting a trans-kingdom activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Antiproliferative activity of flavonoids: influence of the sequential methoxylation state of the flavonoid structure.

PubMed

Moghaddam, Ghazaal; Ebrahimi, Soltan Ahmad; Rahbar-Roshandel, Nahid; Foroumadi, Alireza

2012-07-01

Dracocephalum kotschyi Boiss. has been used as part of an ethnobotanical remedy against many forms of human cancer in Iran. It has been demonstrated that a flavonoid named xanthomicrol from D. kotschyi contributes to its preferential antiproliferative activity against malignant cells. In the present study, the antiproliferative activity of its flavonoid fraction was further characterized. Using liquid-liquid extraction and a semi-preparative reversed-phase HPLC method, eight flavonoid aglycones were isolated from the aerial parts of the plant and their identities were confirmed through MS and NMR analyses as luteolin, naringenin, apigenin, isokaempferide, cirsimaritin, penduletin, xanthomicrol and calycopterin. The in vitro antiproliferative activity of each compound was evaluated against a panel of established normal and malignant cell lines using the MTT assay and some structure-activity relationships were observed. The hydroxyflavones (luteolin, apigenin and isokaempferide) exerted comparable antiproliferative activities against malignant and normal cells, while the methoxylated hydroxyflavones (cirsimaritin, penduletin, xanthomicrol and calycopterin) showed preferential activities against tumor cells. This activity may be of value in treating tumors as it would exert few side effects in normal tissues. Xanthomicrol selectively inhibited the growth of human gastric adenocarcinoma, while calycopterin selectively prevented human acute promyelocytic leukemia and human colon carcinoma cells proliferation. Copyright © 2011 John Wiley & Sons, Ltd.

An investigation into the effects of different existing states of aluminum isopropoxide on copper-based catalysts for direct synthesis of dimethyl ether from syngas

NASA Astrophysics Data System (ADS)

Sun, Kai; Wang, Peng; Bian, Zhongkai; Huang, Wei

2018-01-01

Aluminum isopropoxide (AIP) is a vital raw material to produce high surface area alumina catalyst, which is used for catalytic applications, such as hydrocracking, Fischer-Tropsch and STD (syngas to dimethyl ether) reactions. However, the different existing states have an effect on hydrolysis and condensation in the process of precursor preparation. The Cu/Zn/Al slurry catalysts were prepared by aluminum isopropoxide, which were liquid state, crystalline state and solid state, utilizing a complete liquid phase preparation technology. In the dimethyl ether (DME) synthesis reaction, the aluminum resource of crystalline state was prepared for slurry catalyst, which presented high CO conversion and DME selectivity of 54.32% and 69.74%, respectively. Characterization results indicated that different forms of AIP have the variant coordination numbers of Al-O and polymerization degrees, and the catalyst prepared by crystalline state consists amount of tetra-coordinated Al and few hexa-coordinated Al, which can exert different hydrolysis and condensation process compared with other aluminum sources, and finally it contributes to the strong interaction between active site copper species and Zn/Al species, confirming more Cu+ is responsible for the synthesis of DME in the slurry reactor.

Associations of collectivism with relationship commitment, passion, and mate preferences: opposing roles of parental influence and family allocentrism.

PubMed

Bejanyan, Kathrine; Marshall, Tara C; Ferenczi, Nelli

2015-01-01

In collectivist cultures, families tend to be characterized by respect for parental authority and strong, interdependent ties. Do these aspects of collectivism exert countervailing pressures on mate choices and relationship quality? In the present research, we found that collectivism was associated with greater acceptance of parental influence over mate choice, thereby driving relationship commitment down (Studies 1 and 2), but collectivism was also associated with stronger family ties (referred to as family allocentrism), which drove commitment up (Study 2). Along similar lines, Study 1 found that collectivists' greater acceptance of parental influence on mate choice contributed to their reduced relationship passion, whereas Study 2 found that their greater family allocentrism may have enhanced their passion. Study 2 also revealed that collectivists may have reported a smaller discrepancy between their own preferences for mates high in warmth and trustworthiness and their perception of their parents' preferences for these qualities because of their stronger family allocentrism. However, their higher tolerance of parental influence may have also contributed to a smaller discrepancy in their mate preferences versus their perceptions of their parents' preferences for qualities signifying status and resources. Implications for the roles of collectivism, parental influence, and family allocentrism in relationship quality and mate selection will be discussed.

The Date Palm Tree Rhizosphere Is a Niche for Plant Growth Promoting Bacteria in the Oasis Ecosystem

PubMed Central

Gtari, Maher; Boudabous, Abdellatif; Daffonchio, Daniele; Ouzari, Hadda-Imene

2015-01-01

In arid ecosystems environmental factors such as geoclimatic conditions and agricultural practices are of major importance in shaping the diversity and functionality of plant-associated bacterial communities. Assessing the influence of such factors is a key to understand (i) the driving forces determining the shape of root-associated bacterial communities and (ii) the plant growth promoting (PGP) services they provide. Desert oasis environment was chosen as model ecosystem where agriculture is possible by the microclimate determined by the date palm cultivation. The bacterial communities in the soil fractions associated with the root system of date palms cultivated in seven oases in Tunisia were assessed by culture-independent and dependent approaches. According to 16S rRNA gene PCR-DGGE fingerprinting, the shapes of the date palm rhizosphere bacterial communities correlate with geoclimatic features along a north-south aridity transect. Despite the fact that the date palm root bacterial community structure was strongly influenced by macroecological factors, the potential rhizosphere services reflected in the PGP traits of isolates screened in vitro were conserved among the different oases. Such services were exerted by the 83% of the screened isolates. The comparable numbers and types of PGP traits indicate their importance in maintaining the plant functional homeostasis despite the different environmental selection pressures. PMID:25866759

The date palm tree rhizosphere is a niche for plant growth promoting bacteria in the oasis ecosystem.

PubMed

Ferjani, Raoudha; Marasco, Ramona; Rolli, Eleonora; Cherif, Hanene; Cherif, Ameur; Gtari, Maher; Boudabous, Abdellatif; Daffonchio, Daniele; Ouzari, Hadda-Imene

2015-01-01

In arid ecosystems environmental factors such as geoclimatic conditions and agricultural practices are of major importance in shaping the diversity and functionality of plant-associated bacterial communities. Assessing the influence of such factors is a key to understand (i) the driving forces determining the shape of root-associated bacterial communities and (ii) the plant growth promoting (PGP) services they provide. Desert oasis environment was chosen as model ecosystem where agriculture is possible by the microclimate determined by the date palm cultivation. The bacterial communities in the soil fractions associated with the root system of date palms cultivated in seven oases in Tunisia were assessed by culture-independent and dependent approaches. According to 16S rRNA gene PCR-DGGE fingerprinting, the shapes of the date palm rhizosphere bacterial communities correlate with geoclimatic features along a north-south aridity transect. Despite the fact that the date palm root bacterial community structure was strongly influenced by macroecological factors, the potential rhizosphere services reflected in the PGP traits of isolates screened in vitro were conserved among the different oases. Such services were exerted by the 83% of the screened isolates. The comparable numbers and types of PGP traits indicate their importance in maintaining the plant functional homeostasis despite the different environmental selection pressures.

Bacterial Community Diversity of Oil-Contaminated Soils Assessed by High Throughput Sequencing of 16S rRNA Genes.

PubMed

Peng, Mu; Zi, Xiaoxue; Wang, Qiuyu

2015-09-24

Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs) were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Proteobacteria were the dominant phyla among all the soil samples. The heatmap plot depicted the relative percentage of each bacterial family within each sample and clustered five samples into two groups. For the samples, bacteria in the soils varied at different periods of oil exposure. The oil pollution exerted strong selective pressure to propagate many potentially petroleum degrading bacteria. Redundancy analysis (RDA) indicated that organic matter was the highest determinant factor for explaining the variations in community compositions. This suggests that compared to clean soils, oil-polluted soils support more diverse bacterial communities and soil bacterial community shifts were mainly controlled by organic matter and exposure time. These results provide some useful information for bioremediation of petroleum contaminated soil in the future.

Social Brains in Context: Lesions Targeted to the Song Control System in Female Cowbirds Affect Their Social Network

PubMed Central

Maguire, Sarah E.; Schmidt, Marc F.; White, David J.

2013-01-01

Social experiences can organize physiological, neural, and reproductive function, but there are few experimental preparations that allow one to study the effect individuals have in structuring their social environment. We examined the connections between mechanisms underlying individual behavior and social dynamics in flocks of brown-headed cowbirds (Molothrus ater). We conducted targeted inactivations of the neural song control system in female subjects. Playback tests revealed that the lesions affected females' song preferences: lesioned females were no longer selective for high quality conspecific song. Instead, they reacted to all cowbird songs vigorously. When lesioned females were introduced into mixed-sex captive flocks, they were less likely to form strong pair-bonds, and they no longer showed preferences for dominant males. This in turn created a cascade of effects through the groups. Social network analyses showed that the introduction of the lesioned females created instabilities in the social structure: males in the groups changed their dominance status and their courtship patterns, and even the competitive behavior of other female group-mates was affected. These results reveal that inactivation of the song control system in female cowbirds not only affects individual behavior, but also exerts widespread effects on the stability of the entire social system. PMID:23650558

Feeding ecology of pelagic fish species in the Gulf of Riga (Baltic Sea): the importance of changes in the zooplankton community.

PubMed

Lankov, A; Ojaveer, H; Simm, M; Põllupüü, M; Möllmann, C

2010-12-01

The feeding ecology of four pelagic fish species was studied in relation to their prey availability in the Gulf of Riga (Baltic Sea) during the summer 1999-2006. The zooplankton community was dominated by the cladoceran Bosmina longispina, rotifers Keratella cochlearis and K. quadrata and the copepod Eurytemora affinis, with the highest interannual variability in abundance recorded for B. longispina. The last influenced the diet of adult sprat Sprattus sprattus, juvenile smelt Osmerus eperlanus and three-spined stickleback Gasterosteus aculeatus as these were strongly selecting for B. longispina. The fish feeding activity did not match the abundance dynamics of their preferred prey, suggesting that fishes may switch to consume other prey in case the preferred diet was limited. A considerable dietary overlap indicated high potential competition between pelagic fish species. While herring Clupea harengus membras and G. aculeatus were relying on very different food, the diets of young O. eperlanus and G. aculeatus were very similar. Interannual variability in zooplankton composition and abundance significantly affected the diet composition of fishes, but those changes were insufficient to exert a consistent influence upon fish feeding activity and total amounts of zooplankton consumed. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

Social brains in context: lesions targeted to the song control system in female cowbirds affect their social network.

PubMed

Maguire, Sarah E; Schmidt, Marc F; White, David J

2013-01-01

Social experiences can organize physiological, neural, and reproductive function, but there are few experimental preparations that allow one to study the effect individuals have in structuring their social environment. We examined the connections between mechanisms underlying individual behavior and social dynamics in flocks of brown-headed cowbirds (Molothrus ater). We conducted targeted inactivations of the neural song control system in female subjects. Playback tests revealed that the lesions affected females' song preferences: lesioned females were no longer selective for high quality conspecific song. Instead, they reacted to all cowbird songs vigorously. When lesioned females were introduced into mixed-sex captive flocks, they were less likely to form strong pair-bonds, and they no longer showed preferences for dominant males. This in turn created a cascade of effects through the groups. Social network analyses showed that the introduction of the lesioned females created instabilities in the social structure: males in the groups changed their dominance status and their courtship patterns, and even the competitive behavior of other female group-mates was affected. These results reveal that inactivation of the song control system in female cowbirds not only affects individual behavior, but also exerts widespread effects on the stability of the entire social system.

Modeling spatial variation in risk of presence and insecticide resistance for malaria vectors in Laos

PubMed Central

Marcombe, Sébastien; Laforet, Julie; Brey, Paul T.; Corbel, Vincent; Overgaard, Hans J.

2017-01-01

Climatic, sociological and environmental conditions are known to affect the spatial distribution of malaria vectors and disease transmission. Intensive use of insecticides in the agricultural and public health sectors exerts a strong selective pressure on resistance genes in malaria vectors. Spatio-temporal models of favorable conditions for Anopheles species’ presence were developed to estimate the probability of presence of malaria vectors and insecticide resistance in Lao PDR. These models were based on environmental and meteorological conditions, and demographic factors. GIS software was used to build and manage a spatial database with data collected from various geographic information providers. GIS was also used to build and run the models. Results showed that potential insecticide use and therefore the probability of resistance to insecticide is greater in the southwestern part of the country, specifically in Champasack province and where malaria incidence is already known to be high. These findings can help national authorities to implement targeted and effective vector control strategies for malaria prevention and elimination among populations most at risk. Results can also be used to focus the insecticide resistance surveillance in Anopheles mosquito populations in more restricted area, reducing the area of surveys, and making the implementation of surveillance system for Anopheles mosquito insecticide resistance possible. PMID:28494013

Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol

PubMed Central

Farace, Cristiano; Sánchez-Moreno, Paola; Orecchioni, Marco; Manetti, Roberto; Sgarrella, Francesco; Asara, Yolande; Peula-García, José M.; Marchal, Juan A.; Madeddu, Roberto; Delogu, Lucia G.

2016-01-01

Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications. PMID:26728491

Carrageenans as a new source of drugs with metal binding properties.

PubMed

Khotimchenko, Yuri S; Khozhaenko, Elena V; Khotimchenko, Maxim Y; Kolenchenko, Elena A; Kovalev, Valeri V

2010-04-01

Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y(3+) or Pb(2+) ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that kappa-, iota-, and lambda-carrageenans are favorable sorbents. The largest amount of Y(3+) and Pb(2+) ions are bound by iota-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties.

Associations of Collectivism with Relationship Commitment, Passion, and Mate Preferences: Opposing Roles of Parental Influence and Family Allocentrism

PubMed Central

Bejanyan, Kathrine; Marshall, Tara C.; Ferenczi, Nelli

2015-01-01

In collectivist cultures, families tend to be characterized by respect for parental authority and strong, interdependent ties. Do these aspects of collectivism exert countervailing pressures on mate choices and relationship quality? In the present research, we found that collectivism was associated with greater acceptance of parental influence over mate choice, thereby driving relationship commitment down (Studies 1 and 2), but collectivism was also associated with stronger family ties (referred to as family allocentrism), which drove commitment up (Study 2). Along similar lines, Study 1 found that collectivists’ greater acceptance of parental influence on mate choice contributed to their reduced relationship passion, whereas Study 2 found that their greater family allocentrism may have enhanced their passion. Study 2 also revealed that collectivists may have reported a smaller discrepancy between their own preferences for mates high in warmth and trustworthiness and their perception of their parents’ preferences for these qualities because of their stronger family allocentrism. However, their higher tolerance of parental influence may have also contributed to a smaller discrepancy in their mate preferences versus their perceptions of their parents’ preferences for qualities signifying status and resources. Implications for the roles of collectivism, parental influence, and family allocentrism in relationship quality and mate selection will be discussed. PMID:25719563

Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol.

PubMed

Farace, Cristiano; Sánchez-Moreno, Paola; Orecchioni, Marco; Manetti, Roberto; Sgarrella, Francesco; Asara, Yolande; Peula-García, José M; Marchal, Juan A; Madeddu, Roberto; Delogu, Lucia G

2016-01-05

Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications.

The survival of monogenean (platyhelminth) parasites on fish skin.

PubMed

Kearn, G C

1999-01-01

This review deals with the problems faced by those monogenean (platyhelminth) parasites that attach themselves to fish skin. The structure of the skin and the ways in which the posterior hook-bearing haptor achieves virtually permanent attachment to the skin are considered. Small marginal hooklets are specialized for attachment to superficial host epidermal cells, finding anchorage in the terminal web of keratinous tonofilaments, while large hooks (hamuli) may penetrate into and lodge in the collagenous dermis. The complementary roles of suction and sticky secretions in haptor attachment and the role of the pharynx in temporary attachment during feeding are also considered. During leech-like locomotion the haptor is briefly detached and, at this critical time, the anterior end is strongly fixed to the wet, current-swept and possibly slimy skin by a sticky secretion. This secretion is deployed on paired pads or discs, the latter sometimes backed up by suction. After attachment by the haptor is re-established, the special tegument covering the anterior adhesive areas may be instrumental in their instant release. The role of fish skin in the phenomenon of host specificity and in the generation of a defensive response against monogeneans is considered and site-specificity of parasites on the host's body is discussed. Possible selection pressures exerted by predatory 'cleaner' organisms are briefly evaluated.

Opposing Brain Differences in 16p11.2 Deletion and Duplication Carriers

PubMed Central

Qureshi, Abid Y.; Mueller, Sophia; Snyder, Abraham Z.; Mukherjee, Pratik; Berman, Jeffrey I.; Roberts, Timothy P.L.; Nagarajan, Srikantan S.; Spiro, John E.; Chung, Wendy K.; Sherr, Elliott H.

2014-01-01

Deletions and duplications of the recurrent ∼600 kb chromosomal BP4–BP5 region of 16p11.2 are associated with a broad variety of neurodevelopmental outcomes including autism spectrum disorder. A clue to the pathogenesis of the copy number variant (CNV)'s effect on the brain is that the deletion is associated with a head size increase, whereas the duplication is associated with a decrease. Here we analyzed brain structure in a clinically ascertained group of human deletion (N = 25) and duplication (N = 17) carriers from the Simons Variation in Individuals Project compared with age-matched controls (N = 29 and 33, respectively). Multiple brain measures showed increased size in deletion carriers and reduced size in duplication carriers. The effects spanned global measures of intracranial volume, brain size, compartmental measures of gray matter and white matter, subcortical structures, and the cerebellum. Quantitatively, the largest effect was on the thalamus, but the collective results suggest a pervasive rather than a selective effect on the brain. Detailed analysis of cortical gray matter revealed that cortical surface area displays a strong dose-dependent effect of CNV (deletion > control > duplication), whereas average cortical thickness is less affected. These results suggest that the CNV may exert its opposing influences through mechanisms that influence early stages of embryonic brain development. PMID:25143601

Anticancer Effect of Nemopilema nomurai Jellyfish Venom on HepG2 Cells and a Tumor Xenograft Animal Model

PubMed Central

Bae, Seong Kyeong; Kim, Munki; Pyo, Min Jung; Kim, Minkyung; Yang, Sujeoung; Yoon, Won Duk; Han, Chang Hoon

2017-01-01

Various kinds of animal venoms and their components have been widely studied for potential therapeutic applications. This study evaluated whether Nemopilema nomurai jellyfish venom (NnV) has anticancer activity. NnV strongly induced cytotoxicity of HepG2 cells through apoptotic cell death, as demonstrated by alterations of chromatic morphology, activation of procaspase-3, and an increase in the Bax/Bcl-2 ratio. Furthermore, NnV inhibited the phosphorylation of PI3K, PDK1, Akt, mTOR, p70S6K, and 4EBP1, whereas it enhanced the expression of p-PTEN. Interestingly, NnV also inactivated the negative feedback loops associated with Akt activation, as demonstrated by downregulation of Akt at Ser473 and mTOR at Ser2481. The anticancer effect of NnV was significant in a HepG2 xenograft mouse model, with no obvious toxicity. HepG2 cell death by NnV was inhibited by tetracycline, metalloprotease inhibitor, suggesting that metalloprotease component in NnV is closely related to the anticancer effects. This study demonstrates, for the first time, that NnV exerts highly selective cytotoxicity in HepG2 cells via dual inhibition of the Akt and mTOR signaling pathways, but not in normal cells. PMID:28785288

Antibacterial activity of the soil-bound antimicrobials oxytetracycline and ofloxacin.

PubMed

Peng, Feng-Jiao; Zhou, Li-Jun; Ying, Guang-Guo; Liu, You-Sheng; Zhao, Jian-Liang

2014-04-01

Soil contamination of antimicrobials has become an increasing concern because of the potential risks to the soil microbial ecosystem and human health. The present study investigated sorption and desorption behaviors of oxytetracycline (OTC) and ofloxacin (OFL) in 3 typical soils (A, B, and C), and evaluated the antibacterial activity of soil-adsorbed compounds to a pure sensitive strain Escherichia coli ATCC 25922. The results showed different sorption and desorption behaviors of OTC and OFL in the 3 soils, behaviors that were mainly influenced by soil organic matter content and cation exchange capacity (CEC) as well as pH value. In addition, complexation and cation-exchange reactions were shown to be the main sorption mechanisms. Strong adsorption was found in soil B (with a high organic matter content) and in soil C (with high CEC), whereas enhanced desorption was observed in soil A (with low organic matter content). The results also demonstrated that soil-bound antimicrobials retained antibacterial activity toward E. coli. Opposite patterns of antibacterial activity were found for the 2 antimicrobials in the 3 soils: A>B>C for OFL; and C>B>A for OTC. This finding suggests that soil-bound antimicrobials could still exert selective pressure on soil bacteria although less effectively in comparison with the dissolved forms. © 2014 SETAC.

Transforming Mesoscopic (Bio)materials with Holographic Optical Tweezers

NASA Astrophysics Data System (ADS)

Grier, David

2004-03-01

An optical tweezer uses the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from tens of nanometers to tens of micrometers. Since their introduction in 1986, optical tweezers have become a mainstay of research in biology, physical chemistry, and soft condensed matter physics. This talk highlights recent advances made possible by new classes of optical traps created with computer-designed holograms, a technique we call holographic optical trapping. Holographic optical tweezers can trap hundreds of mesoscopic objects simultaneously and move them independently in three dimensions. Arrays of optical traps can be used to continuously sort heterogeneous samples into selected fractions, a process we call optical fractionation. The same holograms can transform optical traps into optical scalpels and scissors that photochemically transform mesoscopic samples with exquisite spatial resolution. They also can impose arbitrary phase profiles onto the trapping beams, thereby creating optical vortices and related optical machines capable of actuating MEMS devices and driving mesoscale pumps and mixers. These new applications for laser light promise to take optical tweezers out of the laboratory and into real-world applications including manufacturing, diagnostics, and even consumer products. The unprecedented access to the mesoscopic world provided by holographic optical tweezers also offers revolutionary new opportunities for fundamental and applied research.

Identification of a new binding site in E. coli FabH using Molecular dynamics simulations: validation by computational alanine mutagenesis and docking studies.

PubMed

Ramamoorthy, Divya; Turos, Edward; Guida, Wayne C

2013-05-24

FabH (Fatty acid biosynthesis, enzyme H, also referred to as β-ketoacyl-ACP-synthase III) is a key condensing enzyme in the type II fatty acid synthesis (FAS) system. The FAS pathway in bacteria is essential for growth and survival and vastly differs from the human FAS pathway. Enzymes involved in this pathway have arisen as promising biomolecular targets for discovery of new antibacterial drugs. However, currently there are no clinical drugs that selectively target FabH, and known inhibitors of FabH all act within the active site. FabH exerts its catalytic function as a dimer, which could potentially be exploited in developing new strategies for inhibitor design. The aim of this study was to elucidate structural details of the dimer interface region by means of computational modeling, including molecular dynamics (MD) simulations, in order to derive information for the structure-based design of new FabH inhibitors. The dimer interface region was analyzed by MD simulations, trajectory snapshots were collected for further analyses, and docking studies were performed with potential small molecule disruptors. Alanine mutation and docking studies strongly suggest that the dimer interface could be a potential target for anti-infection drug discovery.

Real-Time Simulation of Aeroheating of the Hyper-X Airplane

NASA Technical Reports Server (NTRS)

Gong, Les

2005-01-01

A capability for real-time computational simulation of aeroheating has been developed in support of the Hyper-X program, which is directed toward demonstrating the feasibility of operating an air-breathing ramjet/scramjet engine at mach 5, mach 7, and mach 10. The simulation software will serve as a valuable design tool for initial trajectory studies in which aerodynamic heating is expected to exert a major influence in the design of the Hyper-X airplane; this tool will aid in the selection of materials, sizing of structural skin thicknesses, and selection of components of a thermal-protection system (TPS) for structures that must be insulated against aeroheating.

Photodegradation of an azo dye of the textile industry.

PubMed

Cisneros, Rosario López; Espinoza, Abel Gutarra; Litter, Marta I

2002-07-01

An advanced oxidation treatment, UV/H2O2, was applied to an azo dye, Hispamin Black CA, widely used in the Peruvian textile industry. Rates of color removal and degradation of the dye have been evaluated. A strongly absorbing solution was completely decolorized after 35 min of treatment, and after 60 min an 82% reduction of the total organic carbon (TOC) was obtained. It has been found that the degradation rate increased until an optimum value, beyond which the reagent exerted an inhibitory effect. The degradation rate was also function of pH.

Switching skeletons: hydrostatic support in molting crabs

NASA Technical Reports Server (NTRS)

Taylor, Jennifer R A.; Kier, William M.; Walker, I. D. (Principal Investigator)

2003-01-01

Skeletal support systems are essential for support, movement, muscular antagonism, and locomotion. Crustaceans shed their rigid exoskeleton at each molt yet are still capable of forceful movement. We hypothesize that the soft water-inflated body of newly molted crabs may rely on a hydrostatic skeleton, similar to that of worms and polyps. We measured internal hydrostatic pressure and the force exerted during claw adduction and observed a strong correlation between force and hydrostatic pressure, consistent with hydrostatic skeletal support. This alternation between the two basic skeletal types may be widespread among arthropods.

Evidence that multiple genetic variants of MC4R play a functional role in the regulation of energy expenditure and appetite in Hispanic children1234

PubMed Central

Cole, Shelley A; Voruganti, V Saroja; Cai, Guowen; Haack, Karin; Kent, Jack W; Blangero, John; Comuzzie, Anthony G; McPherson, John D; Gibbs, Richard A

2010-01-01

Background: Melanocortin-4-receptor (MC4R) haploinsufficiency is the most common form of monogenic obesity; however, the frequency of MC4R variants and their functional effects in general populations remain uncertain. Objective: The aim was to identify and characterize the effects of MC4R variants in Hispanic children. Design: MC4R was resequenced in 376 parents, and the identified single nucleotide polymorphisms (SNPs) were genotyped in 613 parents and 1016 children from the Viva la Familia cohort. Measured genotype analysis (MGA) tested associations between SNPs and phenotypes. Bayesian quantitative trait nucleotide (BQTN) analysis was used to infer the most likely functional polymorphisms influencing obesity-related traits. Results: Seven rare SNPs in coding and 18 SNPs in flanking regions of MC4R were identified. MGA showed suggestive associations between MC4R variants and body size, adiposity, glucose, insulin, leptin, ghrelin, energy expenditure, physical activity, and food intake. BQTN analysis identified SNP 1704 in a predicted micro-RNA target sequence in the downstream flanking region of MC4R as a strong, probable functional variant influencing total, sedentary, and moderate activities with posterior probabilities of 1.0. SNP 2132 was identified as a variant with a high probability (1.0) of exerting a functional effect on total energy expenditure and sleeping metabolic rate. SNP rs34114122 was selected as having likely functional effects on the appetite hormone ghrelin, with a posterior probability of 0.81. Conclusion: This comprehensive investigation provides strong evidence that MC4R genetic variants are likely to play a functional role in the regulation of weight, not only through energy intake but through energy expenditure. PMID:19889825

Soil pH mediates the balance between stochastic and deterministic assembly of bacteria

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

Tripathi, Binu M.; Stegen, James C.; Kim, Mincheol

Little is known about the factors affecting the relative influence of stochastic and deterministic processes that governs the assembly of microbial communities in successional soils. Here, we conducted a meta-analysis of bacterial communities using six different successional soils data sets, scattered across different regions, with different pH conditions in early and late successional soils. We found that soil pH was the best predictor of bacterial community assembly and the relative importance of stochastic and deterministic processes along successional soils. Extreme acidic or alkaline pH conditions lead to assembly of phylogenetically more clustered bacterial communities through deterministic processes, whereas pH conditionsmore » close to neutral lead to phylogenetically less clustered bacterial communities with more stochasticity. We suggest that the influence of pH, rather than successional age, is the main driving force in producing trends in phylogenetic assembly of bacteria, and that pH also influences the relative balance of stochastic and deterministic processes along successional soils. Given that pH had a much stronger association with community assembly than did successional age, we evaluated whether the inferred influence of pH was maintained when studying globally-distributed samples collected without regard for successional age. This dataset confirmed the strong influence of pH, suggesting that the influence of soil pH on community assembly processes occurs globally. Extreme pH conditions likely exert more stringent limits on survival and fitness, imposing strong selective pressures through ecological and evolutionary time. Taken together, these findings suggest that the degree to which stochastic vs. deterministic processes shape soil bacterial community assembly is a consequence of soil pH rather than successional age.« less

Trophic structure of amoeba communities near roots of Medicago sativa after contamination with fuel oil no. 6.

PubMed

Cortés-Pérez, Sandra; Rodríguez-Zaragoza, Salvador; Mendoza-López, Ma Remedios

2014-02-01

Root exudation increases microbial activity, selecting bacterial and fungal communities that metabolize organic matter such as hydrocarbons. However, a strong contamination pulse of hydrocarbons around plant roots may reorganize the soil's microbial trophic structure toward amoebae feeding on bacteria. We conducted a microcosm experiment to elucidate the effect of Medicago sativa on the trophic structure of naked amoebae after a strong pulse of pollution (50,000 ppm of fuel oil no. 6, which is a mixture of long chains ranging from C10 to C28). Plants were seeded 24 h after contamination and species of amoebae in the microcosms were identified at 1, 30, and 60 days after pollution. Several species from three trophic groups of naked amoeba were still alive 24 h after the hydrocarbon pulse. Non-planted microcosms harbored three trophic groups after 60 days, while planted ones nourished four groups. The bacterivore group was the most diverse in all microcosms, followed by protist-eaters and omnivores. The quantity of amoebae was significantly higher (3.4×10(3) organisms/g soil) in the planted pots than in the non-planted ones (1.3×10(3) organisms/g soil after 30 days of pollution (P ≤ 0.01). The shortest hydrocarbon chains (C10-C14) disappeared or diminished in all microcosms, and the longest ones increased in the planted ones. M. sativa thus exerted a positive effect on species richness, quantity, and the composition of amoebae trophic groups in contaminated soil. This indirect effect on bacterial predators is another key factor underlying hydrocarbon assimilation by living organisms during phytoremediation.

Insulin promotes diacylglycerol kinase activation by different mechanisms in rat cerebral cortex synaptosomes.

PubMed

Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

2006-10-01

The mechanism by which insulin increases diacylglycerol kinase (DAGK) activity has been studied in cerebral cortex (CC) synaptosomes from adult (3-4 months of age) rats. The purpose of this study was to identify the role of phospholipases C and D (PLC and PLD) in DAGK activation by insulin. Neomycin, an inhibitor of PLC phosphatidylinositol-bisphosphate (PIP2) specific; ethanol, an inhibitor of phosphatidic acid (PA) formation by the promotion of a transphosphatidyl reaction of phosphatidylcholine phospholipase D (PC-PLD); and DL propranolol, an inhibitor of phosphatidate phosphohydrolase (PAP), were used in this study. Insulin (0.1 microM) shielded an increase in PA synthesis by [32P] incorporation using [gamma-32P]ATP as substrate and endogenous diacylglycerol (DAG) as co-substrate. This activated synthesis was strongly inhibited either by ethanol or DL propranolol. Pulse chase experiments also showed a PIP2-PLC activation within 1 min exposure to insulin. When exogenous unsaturated 18:0-20:4 DAG was present, insulin increased PA synthesis significantly. However, this stimulatory effect was not observed in the presence of exogenous saturated (di-16:0). In the presence of R59022, a selective DAGK inhibitor, insulin exerted no stimulatory effect on [32P]PA formation, suggesting a strong relationship between increased PA formation by insulin and DAGK activity. These data indicate that the increased synthesis of PA by insulin could be mediated by the activation of both a PC-PLD pathway to provide DAG and a direct DAGK activation that is associated to the use of 18:0-20:4 DAG species. PIP2-PLC activation may contribute at least partly to the insulin effect on DAGK activity. Copyright 2006 Wiley-Liss, Inc.

Alterations in triglyceride rich lipoproteins are related to endothelial dysfunction in metabolic syndrome.

PubMed

Lucero, Diego; López, Graciela I; Gorzalczany, Susana; Duarte, Mariano; González Ballerga, Esteban; Sordá, Juan; Schreier, Laura; Zago, Valeria

2016-08-01

Our aim was to analyze the effect of circulating triglyceride rich lipoprotein (TRL) on endothelial function in metabolic syndrome (MetS). We studied 40 patients with MetS (ATPIII), divided into those presenting normal endothelial function (n=19) and those with endothelial dysfunction (n=21) by means of the evaluation of pulse wave velocity, before and after brachial artery ischemia. In fasting serum we measured lipid and lipoprotein profile, insulin and glucose (HOMA-IR). Moreover, isolated TRL (d<1006g/l) were chemically characterized. In parallel, using randomly selected TRL from MetS patients with endothelial dysfunction (n=6) and MetS patients with normal endothelial function (n=6), the ability of TRL to inhibit ACh-induced vasorelaxation (10(-9)-10(-5)mM) on aortic rings previously pre-contracted by noradrenaline (10(-8)mM) was evaluated. Interestingly, TRL isolated from MetS patients presenting endothelial dysfunction showed triglyceride over-enrichment (59.1±4.8 vs. 54.1±4.7%; p=0.04), even after adjusting by potential confounders (p=0.05). In addition, while TRL resulting from both MetS groups significantly inhibited endothelium dependent vasorelaxation (p<0.001), TRL from MetS patients with endothelial dysfunction showed a strong tendency to a greater inhibition of vasorelaxation (p=0.06). Moreover, TRL-triglyceride (%) showed a strong tendency to correlate with the grade of vasorelaxation inhibition exerted by TRL (r=0.60; p=0.05). These results, taken together, would allow inferring for the first time that the predominance of triglyceride over-enriched TRL in circulation in MetS would induce endothelial dysfunction, contributing to the inherent cardiovascular risk of MetS. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Ecological modules and roles of species in heathland plant-insect flower visitor networks.

PubMed

Dupont, Yoko L; Olesen, Jens M

2009-03-01

1. Co-existing plants and flower-visiting animals often form complex interaction networks. A long-standing question in ecology and evolutionary biology is how to detect nonrandom subsets (compartments, blocks, modules) of strongly interacting species within such networks. Here we use a network analytical approach to (i) detect modularity in pollination networks, (ii) investigate species composition of modules, and (iii) assess the stability of modules across sites. 2. Interactions between entomophilous plants and their flower-visitors were recorded throughout the flowering season at three heathland sites in Denmark, separated by >or= 10 km. Among sites, plant communities were similar, but composition of flower-visiting insect faunas differed. Visitation frequencies of visitor species were recorded as a measure of insect abundance. 3. Qualitative (presence-absence) interaction networks were tested for modularity. Modules were identified, and species classified into topological roles (peripherals, connectors, or hubs) using 'functional cartography by simulated annealing', a method recently developed by Guimerà & Amaral (2005a). 4. All networks were significantly modular. Each module consisted of 1-6 plant species and 18-54 insect species. Interactions aggregated around one or two hub plant species, which were largely identical at the three study sites. 5. Insect species were categorized in taxonomic groups, mostly at the level of orders. When weighted by visitation frequency, each module was dominated by one or few insect groups. This pattern was consistent across sites. 6. Our study adds support to the conclusion that certain plant species and flower-visitor groups are nonrandomly and repeatedly associated. Within a network, these strongly interacting subgroups of species may exert reciprocal selection pressures on each other. Thus, modules may be candidates for the long-sought key units of co-evolution.

Aronia melanocarpa juice induces a redox-sensitive p73-related caspase 3-dependent apoptosis in human leukemia cells.

PubMed

Sharif, Tanveer; Alhosin, Mahmoud; Auger, Cyril; Minker, Carole; Kim, Jong-Hun; Etienne-Selloum, Nelly; Bories, Pierre; Gronemeyer, Hinrich; Lobstein, Annelise; Bronner, Christian; Fuhrmann, Guy; Schini-Kerth, Valérie B

2012-01-01

Polyphenols are natural compounds widely present in fruits and vegetables, which have antimutagenic and anticancer properties. The aim of the present study was to determine the anticancer effect of a polyphenol-rich Aronia melanocarpa juice (AMJ) containing 7.15 g/L of polyphenols in the acute lymphoblastic leukemia Jurkat cell line, and, if so, to clarify the underlying mechanism and to identify the active polyphenols involved. AMJ inhibited cell proliferation, which was associated with cell cycle arrest in G(2)/M phase, and caused the induction of apoptosis. These effects were associated with an upregulation of the expression of tumor suppressor p73 and active caspase 3, and a downregulation of the expression of cyclin B1 and the epigenetic integrator UHRF1. AMJ significantly increased the formation of reactive oxygen species (ROS), decreased the mitochondrial membrane potential and caused the release of cytochrome c into the cytoplasm. Treatment with intracellular ROS scavengers prevented the AMJ-induced apoptosis and upregulation of the expression of p73 and active caspase 3. The fractionation of the AMJ and the use of identified isolated compounds indicated that the anticancer activity was associated predominantly with chlorogenic acids, some cyanidin glycosides, and derivatives of quercetin. AMJ treatment also induced apoptosis of different human lymphoblastic leukemia cells (HSB-2, Molt-4 and CCRF-CEM). In addition, AMJ exerted a strong pro-apoptotic effect in human primary lymphoblastic leukemia cells but not in human normal primary T-lymphocytes. Thus, the present findings indicate that AMJ exhibits strong anticancer activity through a redox-sensitive mechanism in the p53-deficient Jurkat cells and that this effect involves several types of polyphenols. They further suggest that AMJ has chemotherapeutic properties against acute lymphoblastic leukemia by selectively targeting lymphoblast-derived tumor cells.

Sexual selection on cuticular hydrocarbons in the Australian field cricket, Teleogryllus oceanicus

PubMed Central

Thomas, Melissa L; Simmons, Leigh W

2009-01-01

Background Females in a wide range of taxa have been shown to base their choice of mates on pheromone signals. However, little research has focussed specifically on the form and intensity of selection that mate choice imposes on the pheromone signal. Using multivariate selection analysis, we characterise directly the form and intensity of sexual selection acting on cuticular hydrocarbons, chemical compounds widely used in the selection of mates in insects. Using the Australian field cricket Teleogryllus oceanicus as a model organism, we use three measures of male attractiveness to estimate fitness; mating success, the duration of courtship required to elicit copulation, and subsequent spermatophore attachment duration. Results We found that all three measures of male attractiveness generated sexual selection on male cuticular hydrocarbons, however there were differences in the form and intensity of selection among these three measures. Mating success was the only measure of attractiveness that imposed both univariate linear and quadratic selection on cuticular hydrocarbons. Although we found that all three attractiveness measures generated nonlinear selection, again only mating success was found to exert statistically significant stabilizing selection. Conclusion This study shows that sexual selection plays an important role in the evolution of male cuticular hydrocarbon signals. PMID:19594896

Usability of prostaglandin monotherapy eye droppers.

PubMed

Drew, Tom; Wolffsohn, James S

2015-09-01

To determine the force needed to extract a drop from a range of current prostaglandin monotherapy eye droppers and how this related to the comfortable and maximum pressure subjects could exert. The comfortable and maximum pressure subjects could apply to an eye dropper constructed around a set of cantilevered pressure sensors and mounted above their eye was assessed in 102 subjects (mean 51.2±18.7 years), repeated three times. A load cell amplifier, mounted on a stepper motor controlled linear slide, was constructed and calibrated to test the force required to extract the first three drops from 13 multidose or unidose latanoprost medication eye droppers. The pressure that could be exerted on a dropper comfortably (25.9±17.7 Newtons, range 1.2-87.4) could be exceeded with effort (to 64.8±27.1 Newtons, range 19.9-157.8; F=19.045, p<0.001), and did not differ between repeats (F=0.609, p=0.545). Comfortable and maximum pressures exerted were correlated (r=0.618, p<0.001), neither were influenced strongly by age (r=0.138, p=0.168; r=-0.118, p=0237, respectively), but were lower in women than in men (F=12.757, p=0.001). The force required to expel a drop differed between dropper designs (F=22.528, p<0.001), ranging from 6.4 Newtons to 23.4 Newtons. The force needed to exert successive drops increased (F=36.373, p<0.001) and storing droppers in the fridge further increased the force required (F=7.987, p=0.009). Prostaglandin monotherapy droppers for glaucoma treatment vary in their resistance to extract a drop and with some a drop could not be comfortably achieved by half the population, which may affect compliance and efficacy. 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.

Variation in the Breeding System of Prunella vulgaris L.

PubMed

Qu, Luping; Widrlechner, Mark P

2011-05-01

Prunella vulgaris (Lamiaceae), commonly known as selfheal, is a perennial herb with a long history of use in traditional medicine. Recent studies have found that P. vulgaris possesses anti-inflammatory, antiviral, and antibacterial properties, and it is likely that this will lead to increased commercial demand for this species. To date, research publications on P. vulgaris cultivation and genetics are scarce. Using accessions originally collected from different geographical regions, we investigated the breeding system of this species by observing variation in floral morphology, time of pollen release, and selfed-seed set in bagged flowers and isolated plants. Two types of floral morphology, one with exerted styles, extending past open corollas when viewed from above, and the other with shorter, inserted styles, were found among 30 accessions. Two accessions originally collected from Asia uniformly displayed exerted styles, and 27 accessions had inserted styles. One accession from Oregon displayed variation in this trait among individual plants. Microscopic observation of seven accessions, including ones with both exerted and inserted styles, revealed that they all release pollen to some degree before the flowers open. Using bagged flowers, we found that selfed-seed set varied widely among eight accessions, ranging from 6% to 94%. However, bagging may underestimate seed set for some accessions. The two accessions with the lowest rates when using bagged flowers increased in seed set by 350% and 158%, respectively, when we evaluated single, unbagged plants in isolation cages. The accession with 6% selfed-seed set when bagged also had exerted styles. These findings suggest that mating systems in P. vulgaris may be in the process of evolutionary change and that understanding breeding-system variation should be useful in developing efficient seed-regeneration protocols and breeding and selection strategies for this species.

Variation in the Breeding System of Prunella vulgaris L

PubMed Central

Qu, Luping; Widrlechner, Mark P.

2011-01-01

Prunella vulgaris (Lamiaceae), commonly known as selfheal, is a perennial herb with a long history of use in traditional medicine. Recent studies have found that P. vulgaris possesses anti-inflammatory, antiviral, and antibacterial properties, and it is likely that this will lead to increased commercial demand for this species. To date, research publications on P. vulgaris cultivation and genetics are scarce. Using accessions originally collected from different geographical regions, we investigated the breeding system of this species by observing variation in floral morphology, time of pollen release, and selfed-seed set in bagged flowers and isolated plants. Two types of floral morphology, one with exerted styles, extending past open corollas when viewed from above, and the other with shorter, inserted styles, were found among 30 accessions. Two accessions originally collected from Asia uniformly displayed exerted styles, and 27 accessions had inserted styles. One accession from Oregon displayed variation in this trait among individual plants. Microscopic observation of seven accessions, including ones with both exerted and inserted styles, revealed that they all release pollen to some degree before the flowers open. Using bagged flowers, we found that selfed-seed set varied widely among eight accessions, ranging from 6% to 94%. However, bagging may underestimate seed set for some accessions. The two accessions with the lowest rates when using bagged flowers increased in seed set by 350% and 158%, respectively, when we evaluated single, unbagged plants in isolation cages. The accession with 6% selfed-seed set when bagged also had exerted styles. These findings suggest that mating systems in P. vulgaris may be in the process of evolutionary change and that understanding breeding-system variation should be useful in developing efficient seed-regeneration protocols and breeding and selection strategies for this species. PMID:21776085

Core Muscle Activity, Exercise Preference, and Perceived Exertion during Core Exercise with Elastic Resistance versus Machine.

PubMed

Vinstrup, Jonas; Sundstrup, Emil; Brandt, Mikkel; Jakobsen, Markus D; Calatayud, Joaquin; Andersen, Lars L

2015-01-01

Objectives. To investigate core muscle activity, exercise preferences, and perceived exertion during two selected core exercises performed with elastic resistance versus a conventional training machine. Methods. 17 untrained men aged 26-67 years participated in surface electromyography (EMG) measurements of five core muscles during torso-twists performed from left to right with elastic resistance and in the machine, respectively. The order of the exercises was randomized and each exercise consisted of 3 repetitions performed at a 10 RM load. EMG amplitude was normalized (nEMG) to maximum voluntary isometric contraction (MVC). Results. A higher right erector spinae activity in the elastic exercise compared with the machine exercise (50% [95% CI 36-64] versus 32% [95% CI 18-46] nEMG) was found. By contrast, the machine exercise, compared with the elastic exercise, showed higher left external oblique activity (77% [95% CI 64-90] versus 54% [95% CI 40-67] nEMG). For the rectus abdominis, right external oblique, and left erector spinae muscles there were no significant differences. Furthermore, 76% preferred the torso-twist with elastic resistance over the machine exercise. Perceived exertion (Borg CR10) was not significantly different between machine (5.8 [95% CI 4.88-6.72]) and elastic exercise (5.7 [95% CI 4.81-6.59]). Conclusion. Torso-twists using elastic resistance showed higher activity of the erector spinae, whereas torso-twist in the machine resulted in higher activity of the external oblique. For the remaining core muscles the two training modalities induced similar muscular activation. In spite of similar perceived exertion the majority of the participants preferred the exercise using elastic resistance.

Nano-encrypted Morse code: a versatile approach to programmable and reversible nanoscale assembly and disassembly.

PubMed

Wong, Ngo Yin; Xing, Hang; Tan, Li Huey; Lu, Yi

2013-02-27

While much work has been devoted to nanoscale assembly of functional materials, selective reversible assembly of components in the nanoscale pattern at selective sites has received much less attention. Exerting such a reversible control of the assembly process will make it possible to fine-tune the functional properties of the assembly and to realize more complex designs. Herein, by taking advantage of different binding affinities of biotin and desthiobiotin toward streptavidin, we demonstrate selective and reversible decoration of DNA origami tiles with streptavidin, including revealing an encrypted Morse code "NANO" and reversible exchange of uppercase letter "I" with lowercase "i". The yields of the conjugations are high (>90%), and the process is reversible. We expect this versatile conjugation technique to be widely applicable with different nanomaterials and templates.

Experimental evidence supports a sex-specific selective sieve in mitochondrial genome evolution.

PubMed

Innocenti, Paolo; Morrow, Edward H; Dowling, Damian K

2011-05-13

Mitochondria are maternally transmitted; hence, their genome can only make a direct and adaptive response to selection through females, whereas males represent an evolutionary dead end. In theory, this creates a sex-specific selective sieve, enabling deleterious mutations to accumulate in mitochondrial genomes if they exert male-specific effects. We tested this hypothesis, expressing five mitochondrial variants alongside a standard nuclear genome in Drosophila melanogaster, and found striking sexual asymmetry in patterns of nuclear gene expression. Mitochondrial polymorphism had few effects on nuclear gene expression in females but major effects in males, modifying nearly 10% of transcripts. These were mostly male-biased in expression, with enrichment hotspots in the testes and accessory glands. Our results suggest an evolutionary mechanism that results in mitochondrial genomes harboring male-specific mutation loads.

The strengths of r- and K-selection shape diversity-disturbance relationships.

PubMed

Bohn, Kristin; Pavlick, Ryan; Reu, Björn; Kleidon, Axel

2014-01-01

Disturbance is a key factor shaping species abundance and diversity in plant communities. Here, we use a mechanistic model of vegetation diversity to show that different strengths of r- and K-selection result in different disturbance-diversity relationships. R- and K-selection constrain the range of viable species through the colonization-competition tradeoff, with strong r-selection favoring colonizers and strong K-selection favoring competitors, but the level of disturbance also affects the success of species. This interplay among r- and K-selection and disturbance results in different shapes of disturbance-diversity relationships, with little variation of diversity with no r- and no K-selection, a decrease in diversity with r-selection with disturbance rate, an increase in diversity with K-selection, and a peak at intermediate values with strong r- and K-selection. We conclude that different disturbance-diversity relationships found in observations may reflect different intensities of r- and K-selection within communities, which should be inferable from broader observations of community composition and their ecophysiological trait ranges.

Tumor morphology and phenotypic evolution driven by selective pressure from the microenvironment.

PubMed

Anderson, Alexander R A; Weaver, Alissa M; Cummings, Peter T; Quaranta, Vito

2006-12-01

Emergence of invasive behavior in cancer is life-threatening, yet ill-defined due to its multifactorial nature. We present a multiscale mathematical model of cancer invasion, which considers cellular and microenvironmental factors simultaneously and interactively. Unexpectedly, the model simulations predict that harsh tumor microenvironment conditions (e.g., hypoxia, heterogenous extracellular matrix) exert a dramatic selective force on the tumor, which grows as an invasive mass with fingering margins, dominated by a few clones with aggressive traits. In contrast, mild microenvironment conditions (e.g., normoxia, homogeneous matrix) allow clones with similar aggressive traits to coexist with less aggressive phenotypes in a heterogeneous tumor mass with smooth, noninvasive margins. Thus, the genetic make-up of a cancer cell may realize its invasive potential through a clonal evolution process driven by definable microenvironmental selective forces. Our mathematical model provides a theoretical/experimental framework to quantitatively characterize this selective pressure for invasion and test ways to eliminate it.

The future of EPAC-targeted therapies: agonism versus antagonism.

PubMed

Parnell, Euan; Palmer, Timothy M; Yarwood, Stephen J

2015-04-01

Pharmaceutical manipulation of cAMP levels exerts beneficial effects through the regulation of the exchange protein activated by cAMP (EPAC) and protein kinase A (PKA) signalling routes. Recent attention has turned to the specific regulation of EPAC isoforms (EPAC1 and EPAC2) as a more targeted approach to cAMP-based therapies. For example, EPAC2-selective agonists could promote insulin secretion from pancreatic β cells, whereas EPAC1-selective agonists may be useful in the treatment of vascular inflammation. By contrast, EPAC1 and EPAC2 antagonists could both be useful in the treatment of heart failure. Here we discuss whether the best way forward is to design EPAC-selective agonists or antagonists and the current strategies being used to develop isoform-selective, small-molecule regulators of EPAC1 and EPAC2 activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Commercial processed soy-based food product contains glycated and glycoxidated lunasin proteoforms.

PubMed

Serra, Aida; Gallart-Palau, Xavier; See-Toh, Rachel Su-En; Hemu, Xinya; Tam, James P; Sze, Siu Kwan

2016-05-18

Nutraceuticals have been proposed to exert positive effects on human health and confer protection against many chronic diseases. A major bioactive component of soy-based foods is lunasin peptide, which has potential to exert a major impact on the health of human consumers worldwide, but the biochemical features of dietary lunasin still remain poorly characterized. In this study, lunasin was purified from a soy-based food product via strong anion exchange solid phase extraction and then subjected to top-down mass spectrometry analysis that revealed in detail the molecular diversity of lunasin in processed soybean foods. We detected multiple glycated proteoforms together with potentially toxic advanced glycation end products (AGEs) derived from lunasin. In both cases, modification sites were Lys24 and Lys29 located at the helical region that shows structural homology with a conserved region of chromatin-binding proteins. The identified post-translational modifications may have an important repercussion on lunasin epigenetic regulatory capacity. Taking together, our results demonstrate the importance of proper chemical characterization of commercial processed food products to assess their impact on consumer's health and risk of chronic diseases.

Atypical autonomic dysreflexia during robotic-assisted body weight supported treadmill training in an individual with motor incomplete spinal cord injury.

PubMed

Geigle, Paula R; Frye, Sara Kate; Perreault, John; Scott, William H; Gorman, Peter H

2013-03-01

A 41-year-old man with a history of C6 American Spinal Injury Association (ASIA) Impairment Scale (AIS) C spinal cord injury (SCI), enrolled in an Institutional Review Board (IRB)-approved, robotic-assisted body weight-supported treadmill training (BWSTT), and aquatic exercise research protocol developed asymptomatic autonomic dysreflexia (AD) during training. Little information is available regarding the relationship of robotic-assisted BWSTT and AD. After successfully completing 36 sessions of aquatic exercise, he reported exertional fatigue during his 10th Lokomat intervention and exhibited asymptomatic or silent AD during this and the three subsequent BWSTT sessions. Standard facilitators of AD were assessed and no obvious irritant identified other than the actual physical exertion and positioning required during robotic-assisted BWSTT. Increased awareness of potential silent AD presenting during robotic assisted BWSTT training for individuals with motor incomplete SCI is required as in this case AD clinical signs were not concurrent with occurrence. Frequent vital sign assessment before, during, and at conclusion of each BWSTT session is strongly recommended.

A cell-penetrating peptide analogue, P7, exerts antimicrobial activity against Escherichia coli ATCC25922 via penetrating cell membrane and targeting intracellular DNA.

PubMed

Li, Lirong; Shi, Yonghui; Cheng, Xiangrong; Xia, Shufang; Cheserek, Maureen Jepkorir; Le, Guowei

2015-01-01

The antibacterial activities and mechanism of a new P7 were investigated in this study. P7 showed antimicrobial activities against five harmful microorganisms which contaminate and spoil food (MIC=4-32 μM). Flow cytometry and scanning electron microscopy analyses demonstrated that P7 induced pore-formation on the cell surface and led to morphological changes but did not lyse cell. Confocal fluorescence microscopic observations and flow cytometry analysis expressed that P7 could penetrate the Escherichia coli cell membrane and accumulate in the cytoplasm. Moreover, P7 possessed a strong DNA binding affinity. Further cell cycle analysis and change in gene expression analysis suggested that P7 induced a decreased expression in the genes involved in DNA replication. Up-regulated expression genes encoding DNA damage repair. This study suggests that P7 could be applied as a candidate for the development of new food preservatives as it exerts its antibacterial activities by penetrating cell membranes and targets intracellular DNA. Copyright © 2014 Elsevier Ltd. All rights reserved.

Competition and cooperation among similar representations: toward a unified account of facilitative and inhibitory effects of lexical neighbors.

PubMed

Chen, Qi; Mirman, Daniel

2012-04-01

One of the core principles of how the mind works is the graded, parallel activation of multiple related or similar representations. Parallel activation of multiple representations has been particularly important in the development of theories and models of language processing, where coactivated representations (neighbors) have been shown to exhibit both facilitative and inhibitory effects on word recognition and production. Researchers generally ascribe these effects to interactive activation and competition, but there is no unified explanation for why the effects are facilitative in some cases and inhibitory in others. We present a series of simulations of a simple domain-general interactive activation and competition model that is broadly consistent with more specialized domain-specific models of lexical processing. The results showed that interactive activation and competition can indeed account for the complex pattern of reversals. Critically, the simulations revealed a core computational principle that determines whether neighbor effects are facilitative or inhibitory: strongly active neighbors exert a net inhibitory effect, and weakly active neighbors exert a net facilitative effect.

Ganoderma lucidum exerts anti-tumor effects on ovarian cancer cells and enhances their sensitivity to cisplatin.

PubMed

Zhao, Sufen; Ye, Gang; Fu, Guodong; Cheng, Jian-Xin; Yang, Burton B; Peng, Chun

2011-05-01

Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibition of tumor cell growth. However, the effect of Ganoderma lucidum on epithelial ovarian cancer (EOC), the most fatal gynecological malignancy, has not yet been reported. In this study, we determined whether Ganoderma lucidum regulates EOC cell activity. Using several cell lines derived from EOC, we found that Ganoderma lucidum strongly decreased cell numbers in a dose-dependent manner. Ganoderma lucidum also inhibited colony formation, cell migration and spheroid formation. In particular, Ganoderma lucidum was effective in inhibiting cell growth in both chemosensitive and chemoresistant cells and the treatment with Ganoderma lucidum significantly enhanced the effect of cisplatin on EOC cells. Furthermore, Ganoderma lucidum induced cell cycle arrest at the G2/M phase and also induced apoptosis by activating caspase 3. Finally, Ganoderma lucidum increased p53 but inhibited Akt expression. Taken together, these findings suggest that Ganoderma lucidum exerts multiple anti-tumor effects on ovarian cancer cells and can enhance the sensitivity of EOC cells to cisplatin.

Chemosignalling effects of human tears revisited: Does exposure to female tears decrease males' perception of female sexual attractiveness?

PubMed

Gračanin, Asmir; van Assen, Marcel A L M; Omrčen, Višnja; Koraj, Ivana; Vingerhoets, Ad J J M

2017-01-01

Gelstein et al. reported the results of three experiments suggesting a dampening influence of inhalation of female emotional tears on males' arousal and perception of female sexual attractiveness, specifically in non-sexual situations. This prompted the hypothesis that crying exerts its influence on others not only via the auditory and visual mode but also via chemosignals. In three studies, we attempted to replicate and extend Gelstein et al.'s findings by including an additional condition with irritant tears, by using pictures of sexually attractive women, and by testing related hypotheses on the pro-social effects of exposure to tears. All three studies, separately or combined in a meta-analysis, failed to replicate the original inhibitory effects of tears. In addition, sniffing tears did not affect measures of connectedness, aggression and pro-social behaviour. It is concluded that the effects of female tears on male arousal and perception of female sexual attractiveness, if any, are very weak at best. Rather, it seems that crying exerts its strong inter-personal effects through the visual and auditory sensory channels.

A Molecular Neurobiological Approach to Understanding the Aetiology of Chronic Fatigue Syndrome (Myalgic Encephalomyelitis or Systemic Exertion Intolerance Disease) with Treatment Implications.

PubMed

Monro, Jean A; Puri, Basant K

2018-02-06

Currently, a psychologically based model is widely held to be the basis for the aetiology and treatment of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME)/systemic exertion intolerance disease (SEID). However, an alternative, molecular neurobiological approach is possible and in this paper evidence demonstrating a biological aetiology for CFS/ME/SEID is adduced from a study of the history of the disease and a consideration of the role of the following in this disease: nitric oxide and peroxynitrite, oxidative and nitrosative stress, the blood-brain barrier and intestinal permeability, cytokines and infections, metabolism, structural and chemical brain changes, neurophysiological changes and calcium ion mobilisation. Evidence is also detailed for biologically based potential therapeutic options, including: nutritional supplementation, for example in order to downregulate the nitric oxide-peroxynitrite cycle to prevent its perpetuation; antiviral therapy; and monoclonal antibody treatment. It is concluded that there is strong evidence of a molecular neurobiological aetiology, and so it is suggested that biologically based therapeutic interventions should constitute a focus for future research into CFS/ME/SEID.

Commercial processed soy-based food product contains glycated and glycoxidated lunasin proteoforms

PubMed Central

Serra, Aida; Gallart-Palau, Xavier; See-Toh, Rachel Su-En; Hemu, Xinya; Tam, James P.; Sze, Siu Kwan

2016-01-01

Nutraceuticals have been proposed to exert positive effects on human health and confer protection against many chronic diseases. A major bioactive component of soy-based foods is lunasin peptide, which has potential to exert a major impact on the health of human consumers worldwide, but the biochemical features of dietary lunasin still remain poorly characterized. In this study, lunasin was purified from a soy-based food product via strong anion exchange solid phase extraction and then subjected to top-down mass spectrometry analysis that revealed in detail the molecular diversity of lunasin in processed soybean foods. We detected multiple glycated proteoforms together with potentially toxic advanced glycation end products (AGEs) derived from lunasin. In both cases, modification sites were Lys24 and Lys29 located at the helical region that shows structural homology with a conserved region of chromatin-binding proteins. The identified post-translational modifications may have an important repercussion on lunasin epigenetic regulatory capacity. Taking together, our results demonstrate the importance of proper chemical characterization of commercial processed food products to assess their impact on consumer’s health and risk of chronic diseases. PMID:27189269

Trust in direct leaders and top leaders: A trickle-up model.

PubMed

Fulmer, C Ashley; Ostroff, Cheri

2017-04-01

Low levels of employee trust in top leaders pose challenges to organizations with respect to retention, performance, and profits. This research examines how trust in top leaders can be fostered through the relationships individuals have with their direct leaders. We propose a trickle-up model whereby trust in direct leaders exerts an upward influence on trust in top leaders. Drawing on the group value model, we predict that direct leaders' procedural justice serves as the key mechanism in facilitating the trickle-up process. Further, this process should be particularly strong for employees high on vertical collectivism, and the trickled-up trust in top leaders should exert a stronger impact on employees' overall performance in the organization than trust in direct leaders. Multiphase and multisource data from 336 individuals support these hypotheses. The findings advance our understanding of trust and leadership by highlighting that trust in leaders at different levels does not form independently and that trust in leaders trickles up across hierarchical levels. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Anti-mitotic potential of 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin in 5-fluorouracil-resistant human gastric cancer cell line SNU620/5-FU

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

Kim, Nam Hyun; Kim, Su-Nam; Oh, Joa Sub

2012-02-24

Highlights: Black-Right-Pointing-Pointer DBC exerts antiproliferative potential against 5FU-resistant human gastric cancer cells. Black-Right-Pointing-Pointer This effect is mediated by destabilization of microtubules and subsequent mitotic arrest. Black-Right-Pointing-Pointer DBC enhances apoptosis via caspase activation and downregulation of antiapoptotic genes. -- Abstract: In this study, we investigate an anti-mitotic potential of the novel synthetic coumarin-based compound, 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin, in 5-fluorouracil-resistant human gastric cancer cell line SNU-620-5FU and its parental cell SNU-620. It exerts the anti-proliferative effects with similar potencies against both cancer cells, which is mediated by destabilization of microtubules and subsequent mitotic arrest. Furthermore, this compound enhances caspase-dependent apoptotic cell deathmore » via decreased expression of anti-apoptotic genes. Taken together, our data strongly support anti-mitotic potential of 7-diethylamino-3(2 Prime -benzoxazolyl)-coumarin against drug-resistant cancer cells which will prompt us to further develop as a novel microtubule inhibitor for drug-resistant cancer chemotherapy.« less

Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitro.

PubMed

Jiménez-Reina, L; Cañete, R; de la Torre, M J; Bernal, G

2002-01-01

Growth hormone (GH) is secreted in the anterior pituitary gland by the somatotroph cells. Secretion is regulated by growth hormone releasing hormone (GHRH) and somatostatin. Morever, GH secretagogues (GHS) can exert a considerable effect on GH secretion. In order to determine the effects of chronic treatment with the GHS Ipamorelin on the composition of the somatotroph cell population and on somatotroph GH content, an in vitro analysis was performed of the percentage of somatotroph cells (% of total), the ratio of different GH cell types (strongly/weakly-staining) and individual GH content, in pituitary cell cultures obtained from young female rats receiving Ipamorelin over 21 days (Ipamorelin group) and the effects were compared with those of GHRH (GHRH group) or saline (saline group). The ultrastructure of somatotroph cells did not change, but the volume density of secretion granules was increased (P<0.05) by previous in vivo Ipamorelin or GHRH treatment. In 3-day basal pituitary cell monolayer cultures, the percentage of somatotroph cells showed no modifications between groups, nor was there any change in the ratio of strongly/weakly immunostaining GH cells. In the Ipamorelin group alone, in vitro treatment with Ipamorelin (10(-8) M), or GHRP 6 (10(-8) M), or GHRH (10(-8) M) for 4 hours, increased the percentage of somatotroph cells, without modifying the ratio of strongly/weakly immunostained GH cells. Basal intracellular GH content in somatotroph cells over 4 hours was lower in the Ipamorelin group and the GHRH group than in the saline group. Only in the Ipamorelin group did Ipamorelin (10(-8) M), GHRP 6 (10(-8) M) and GHRH (10(-8) M) prompt increased intracellular GH content. These data suggest that, at least in the young female rat, the GHS Ipamorelin is able to exert a dynamic control effect on the somatotroph population and on GH hormone content.

BNN-20, a synthetic microneurotrophin, strongly protects dopaminergic neurons in the "weaver" mouse, a genetic model of dopamine-denervation, acting through the TrkB neurotrophin receptor.

PubMed

Botsakis, Konstantinos; Mourtzi, Theodora; Panagiotakopoulou, Vasiliki; Vreka, Malamati; Stathopoulos, Georgios T; Pediaditakis, Iosif; Charalampopoulos, Ioannis; Gravanis, Achilleas; Delis, Foteini; Antoniou, Katerina; Zisimopoulos, Dimitrios; Georgiou, Christos D; Panagopoulos, Nikolaos T; Matsokis, Nikolaos; Angelatou, Fevronia

2017-07-15

Neurotrophic factors are among the most promising treatments aiming at slowing or stopping and even reversing Parkinson's disease (PD). However, in most cases, they cannot readily cross the human blood-brain-barrier (BBB). Herein, we propose as a therapeutic for PD the small molecule 17-beta-spiro-[5-androsten-17,2'-oxiran]-3beta-ol (BNN-20), a synthetic analogue of DHEA, which crosses the BBB and is deprived of endocrine side-effects. Using the "weaver" mouse, a genetic model of PD, which exhibits progressive dopaminergic neurodegeneration in the Substantia Nigra (SN), we have shown that long-term administration (P1-P21) of BNN-20 almost fully protected the dopaminergic neurons and their terminals, via i) a strong anti-apoptotic effect, probably mediated through the Tropomyosin receptor kinase B (TrkB) neurotrophin receptor's PI3K-Akt-NF-κB signaling pathway, ii) by exerting an efficient antioxidant effect, iii) by inducing significant anti-inflammatory activity and iv) by restoring Brain-Derived Neurotrophic Factor (BDNF) levels. By intercrossing "weaver" with NGL mice (dual GFP/luciferase-NF-κΒ reporter mice, NF-κΒ.GFP.Luc), we obtained Weaver/NGL mice that express the NF-κB reporter in all somatic cells. Acute BNN-20 administration to Weaver/NGL mice induced a strong NF-κB-dependent transcriptional response in the brain as detected by bioluminescence imaging, which was abolished by co-administration of the TrkB inhibitor ANA-12. This indicates that BNN-20 exerts its beneficial action (at least in part) through the TrkB-PI3K-Akt-NF-κB signaling pathway. These results could be of clinical relevance, as they suggest BNN-20 as an important neuroprotective agent acting through the TrkB neurotrophin receptor pathway, mimicking the action of the endogenous neurotrophin BDNF. Thus BNN-20 could be proposed for treatment of PD. Copyright © 2017. Published by Elsevier Ltd.

[Central muscle relaxant activities of 2-methyl-3-aminopropiophenone derivatives].

PubMed

Kontani, H; Mano, A; Koshiura, R; Yamazaki, M; Shimada, Y; Oshita, M; Morikawa, K; Kato, H; Ito, Y

1987-02-01

In this experiment, we synthetized new 2-methyl-3-aminopropiophenone (MP) derivatives, whose structure is known to have central muscle relaxant activities, and quinolizidine and indan . tetralin derivatives derived from MP by cyclization, and we investigated the central muscle relaxant activity. Among the quinolizidine derivatives, there was a very strong central depressant agent, trans (3H, 9aH)-3-(p-chloro) benzoyl-quinolizidine (HSR-740), and among the indan . tetralin derivatives, there was an excitant agents, trans (1H, 2H)-5-methoxy-3, 3-dimethyl-2-piperidinomethyl indan-1-ol (HSR-719). From the results, these derivatives were not considered to be adequate for central muscle relaxant. Among the MP derivatives, (4'-chloro-2'-methoxy-3-piperidino) propiophenone HCl (HSR-733) and (4'-ethyl-2-methyl-3-pyrrolidino) propiophenone HCl (HSR-770) strongly inhibited the cooperative movement in the rotating rod method using mice, and it exerted almost the same depressant activity on the cross extensor reflex using alpha-chloralose anesthetized rats. However, the inhibitory effects of HSR-733 on the anemic decerebrate rigidity and the rigidity induced by intracollicular decerebration in rats were weaker than those of HSR-770 and eperisone. In spinal cats, at a low dose (5 mg/kg, i.v.), HSR-733 depressed monosynaptic and dorsal root reflex potentials as compared with polysynaptic reflex potentials, and inhibitory effects of HSR-733 on these three reflex potentials were more potent than those of eperisone and HSR-770. Although HSR-770 acts on the spinal cord and supraspinal level on which eperisone has been reported to act, HSR-733 may mainly act on the spinal cord. These results indicate that the MP derivative with a 2-methyl group may be suitable as a central muscle relaxant. HSR-770, which has equipotent muscle relaxant activity to eperisone, exerted strong inhibitory effects on oxotremorine-induced tremor and weak inhibitory effects on spontaneous motor activity in the Animex method using mice, as compared with eperisone.

Influence of Strong versus Weak Fair Employment Policies and Applicant's Sex on Selection Decisions and Salary Recommendations in a Management Simulation.

ERIC Educational Resources Information Center

Rosen, Benson; Mericle, Mary F.

1979-01-01

Strong and weak policies on fair employment were equally effective in counteracting sex bias in selection decisions; however, lower starting salaries were recommended for females compared to males in the strong fair employment policy condition. (Author/IRT)

The novel selective PPARα modulator (SPPARMα) pemafibrate improves dyslipidemia, enhances reverse cholesterol transport and decreases inflammation and atherosclerosis.

PubMed

Hennuyer, Nathalie; Duplan, Isabelle; Paquet, Charlotte; Vanhoutte, Jonathan; Woitrain, Eloise; Touche, Véronique; Colin, Sophie; Vallez, Emmanuelle; Lestavel, Sophie; Lefebvre, Philippe; Staels, Bart

2016-06-01

Atherosclerosis is characterized by lipid accumulation and chronic inflammation in the arterial wall. Elevated levels of apolipoprotein (apo) B-containing lipoproteins are a risk factor for cardiovascular disease (CVD). By contrast, plasma levels of functional high-density lipoprotein (HDL) and apoA-I are protective against CVD by enhancing reverse cholesterol transport (RCT). Activation of peroxisome proliferator-activated receptor-α (PPARα), a ligand-activated transcription factor, controls lipid metabolism, cellular cholesterol trafficking in macrophages and influences inflammation. To study whether pharmacological activation of PPARα with a novel highly potent and selective PPARα modulator, pemafibrate, improves lipid metabolism, macrophage cholesterol efflux, inflammation and consequently atherosclerosis development in vitro and in vivo using human apolipoprotein E2 Knock-In (apoE2KI) and human apoA-I transgenic (hapoA-I tg) mice. Pemafibrate treatment decreases apoB secretion in chylomicrons by polarized Caco-2/TC7 intestinal epithelium cells and reduces triglyceride levels in apoE2KI mice. Pemafibrate treatment of hapoA-I tg mice increases plasma HDL cholesterol, apoA-I and stimulates RCT to feces. In primary human macrophages, pemafibrate promotes macrophage cholesterol efflux to HDL and exerts anti-inflammatory activities. Pemafibrate also reduces markers of inflammation and macrophages in the aortic crosses as well as aortic atherosclerotic lesion burden in western diet-fed apoE2KI mice. These results demonstrate that the novel selective PPARα modulator pemafibrate exerts beneficial effects on lipid metabolism, RCT and inflammation resulting in anti-atherogenic properties. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The genealogy of sequences containing multiple sites subject to strong selection in a subdivided population.

PubMed Central

Nordborg, Magnus; Innan, Hideki

2003-01-01

A stochastic model for the genealogy of a sample of recombining sequences containing one or more sites subject to selection in a subdivided population is described. Selection is incorporated by dividing the population into allelic classes and then conditioning on the past sizes of these classes. The past allele frequencies at the selected sites are thus treated as parameters rather than as random variables. The purpose of the model is not to investigate the dynamics of selection, but to investigate effects of linkage to the selected sites on the genealogy of the surrounding chromosomal region. This approach is useful for modeling strong selection, when it is natural to parameterize the past allele frequencies at the selected sites. Several models of strong balancing selection are used as examples, and the effects on the pattern of neutral polymorphism in the chromosomal region are discussed. We focus in particular on the statistical power to detect balancing selection when it is present. PMID:12663556

The genealogy of sequences containing multiple sites subject to strong selection in a subdivided population.

PubMed

Nordborg, Magnus; Innan, Hideki

2003-03-01

A stochastic model for the genealogy of a sample of recombining sequences containing one or more sites subject to selection in a subdivided population is described. Selection is incorporated by dividing the population into allelic classes and then conditioning on the past sizes of these classes. The past allele frequencies at the selected sites are thus treated as parameters rather than as random variables. The purpose of the model is not to investigate the dynamics of selection, but to investigate effects of linkage to the selected sites on the genealogy of the surrounding chromosomal region. This approach is useful for modeling strong selection, when it is natural to parameterize the past allele frequencies at the selected sites. Several models of strong balancing selection are used as examples, and the effects on the pattern of neutral polymorphism in the chromosomal region are discussed. We focus in particular on the statistical power to detect balancing selection when it is present.

Maintenance of Genetic Variability under Strong Stabilizing Selection: A Two-Locus Model

PubMed Central

Gavrilets, S.; Hastings, A.

1993-01-01

We study a two locus model with additive contributions to the phenotype to explore the relationship between stabilizing selection and recombination. We show that if the double heterozygote has the optimum phenotype and the contributions of the loci to the trait are different, then any symmetric stabilizing selection fitness function can maintain genetic variability provided selection is sufficiently strong relative to linkage. We present results of a detailed analysis of the quadratic fitness function which show that selection need not be extremely strong relative to recombination for the polymorphic equilibria to be stable. At these polymorphic equilibria the mean value of the trait, in general, is not equal to the optimum phenotype, there exists a large level of negative linkage disequilibrium which ``hides'' additive genetic variance, and different equilibria can be stable simultaneously. We analyze dependence of different characteristics of these equilibria on the location of optimum phenotype, on the difference in allelic effect, and on the strength of selection relative to recombination. Our overall result that stabilizing selection does not necessarily eliminate genetic variability is compatible with some experimental results where the lines subject to strong stabilizing selection did not have significant reductions in genetic variability. PMID:8514145

Floral polymorphism and the fitness implications of attracting pollinating and florivorous insects.

PubMed

de Jager, Marinus L; Ellis, Allan G

2014-01-01

Floral polymorphism is frequently attributed to pollinator-mediated selection. Multiple studies, however, have revealed the importance of non-pollinating visitors in floral evolution. Using the polymorphic annual daisy Ursinia calenduliflora, this study investigated the importance of different insect visitors, and their effects on fitness, in the maintenance of floral polymorphism. The spatial structure of a discrete floral polymorphism was characterized based on the presence/absence of anthocyanin floret spots in U. calenduliflora. A 3-year observational study was then conducted in polymorphic populations to investigate differences in visitation rates of dominant visitors to floral morphs. Experiments were performed to explore the floral preference of male and female Megapalpus capensis (the dominant insect visitor) and their effectiveness as pollinators. Next, floral damage by antagonistic florivores and the reproductive success of the two floral morphs were surveyed in multiple populations and years. Floral polymorphism in U. calenduliflora was structured spatially, as were insect visitation patterns. Megapalpus capensis males were the dominant visitors and exhibited strong preference for the spotted morph in natural and experimental observations. While this may indicate potential fitness benefits for the spotted morph, female fitness did not differ between floral morphs. However, as M. capensis males are very efficient at exporting U. calenduliflora pollen, their preference may likely increase the reproductive fitness of the spotted morph through male fitness components. The spotted morph, however, also suffered significantly greater costs due to ovule predation by florivores than the spotless morph. The results suggest that pollinators and florivores may potentially exert antagonistic selection that could contribute to the maintenance of floral polymorphism across the range of U. calenduliflora. The relative strength of selection imposed by each agent is potentially determined by insect community composition and abundance at each site, highlighting the importance of community context in the evolution of floral phenotypes.

Within-Host Evolution of Simian Arteriviruses in Crab-Eating Macaques

PubMed Central

Moncla, Louise H.; Weiler, Andrea M.; Barry, Gabrielle; Weinfurter, Jason T.; Dinis, Jorge M.; Charlier, Olivia; Lauck, Michael; Bailey, Adam L.; Wahl-Jensen, Victoria; Nelson, Chase W.; Johnson, Joshua C.; Caì, Yíngyún; Goldberg, Tony L.; O'Connor, David H.; Jahrling, Peter B.

2016-01-01

ABSTRACT Simian arteriviruses are a diverse clade of viruses infecting captive and wild nonhuman primates. We recently reported that Kibale red colobus virus 1 (KRCV-1) causes a mild and self-limiting disease in experimentally infected crab-eating macaques, while simian hemorrhagic fever virus (SHFV) causes lethal viral hemorrhagic fever. Here we characterize how these viruses evolved during replication in cell culture and in experimentally infected macaques. During passage in cell culture, 68 substitutions that were localized in open reading frames (ORFs) likely associated with host cell entry and exit became fixed in the KRCV-1 genome. However, we did not detect any strong signatures of selection during replication in macaques. We uncovered patterns of evolution that were distinct from those observed in surveys of wild red colobus monkeys, suggesting that these species may exert different adaptive challenges for KRCV-1. During SHFV infection, we detected signatures of selection on ORF 5a and on a small subset of sites in the genome. Overall, our data suggest that patterns of evolution differ markedly among simian arteriviruses and among host species. IMPORTANCE Certain RNA viruses can cross species barriers and cause disease in new hosts. Simian arteriviruses are a diverse group of related viruses that infect captive and wild nonhuman primates, with associated disease severity ranging from apparently asymptomatic infections to severe, viral hemorrhagic fevers. We infected nonhuman primate cell cultures and then crab-eating macaques with either simian hemorrhagic fever virus (SHFV) or Kibale red colobus virus 1 (KRCV-1) and assessed within-host viral evolution. We found that KRCV-1 quickly acquired a large number of substitutions in its genome during replication in cell culture but that evolution in macaques was limited. In contrast, we detected selection focused on SHFV ORFs 5a and 5, which encode putative membrane proteins. These patterns suggest that in addition to diverse pathogenic phenotypes, these viruses may also exhibit distinct patterns of within-host evolution both in vitro and in vivo. PMID:27974564

Typhoons exert significant but differential impacts on net ecosystem carbon exchange of subtropical mangrove forests in China

NASA Astrophysics Data System (ADS)

Chen, H.; Lu, W.; Yan, G.; Yang, S.; Lin, G.

2014-10-01

Typhoons are very unpredictable natural disturbances to subtropical mangrove forests in Asian countries, but little information is available on how these disturbances affect ecosystem level carbon dioxide (CO2) exchange of mangrove wetlands. In this study, we examined short-term effect of frequent strong typhoons on defoliation and net ecosystem CO2 exchange (NEE) of subtropical mangroves, and also synthesized 19 typhoons during a 4-year period between 2009 and 2012 to further investigate the regulation mechanisms of typhoons on ecosystem carbon and water fluxes following typhoon disturbances. Strong wind and intensive rainfall caused defoliation and local cooling effect during the typhoon season. Daily total NEE values decreased by 26-50% following some typhoons (e.g., W28-Nockten, W35-Molave and W35-Lio-Fan), but significantly increased (43-131%) following typhoon W23-Babj and W38-Megi. The magnitudes and trends of daily NEE responses were highly variable following different typhoons, which were determined by the balance between the variances of gross ecosystem production (GEP) and ecosystem respiration (RE). Furthermore, results from our synthesis indicated that the landfall time of typhoon, wind speed and rainfall were the most important factors controlling the CO2 fluxes following typhoon events. These findings indicate that different types of typhoon disturbances can exert very different effects on CO2 fluxes of mangrove ecosystems and that typhoon will likely have larger impacts on carbon cycle processes in subtropical mangrove ecosystems as the intensity and frequency of typhoons are predicted to increase under future global climate change scenarios.

Experimental resin cements containing bioactive fillers reduce matrix metalloproteinase-mediated dentin collagen degradation.

PubMed

Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Thimoty F; Toledano, Manuel

2012-09-01

Collagen dentin matrix may represent a suitable scaffold to be remineralized in the presence of bioactive materials. The purpose of this study was to determine if experimental resin cements containing bioactive fillers may modulate matrix metalloproteinase-mediated collagen degradation of etched dentin. Human dentin beams demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (Sylc; OSspray Ltd, London, UK), and (3) resin with β-tricalcium phosphate-modified calcium silicate cement (HCAT-β) particles. The filler/resin ratio was 40/60 wt%. The specimens were stored in artificial saliva, and the determination of C-terminal telopeptide (ICTP) was performed by radioimmunoassay after 24 hours, 1 week, and 4 weeks. Scanning electron microscopic analysis of dentin surfaces after 4 weeks of storage was also executed. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced the MMP activity in demineralized dentin. Resin-containing Bioglass 45S5 particles exerted higher and more stable protection of collagen at all tested dentin states and time points. HCAT-β induced collagen protection from MMPs only in EDTA-treated specimens. Dentin remineralization was achieved when dentin was infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced in resin-infiltrated dentin. The inclusion of Bioglass 45S5 particles exerted an additional protection of collagen during dentin remineralization. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Zinc incorporation improves biological activity of beta-tricalcium silicate resin-based cement.

PubMed

Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Tim F; Toledano, Manuel

2014-11-01

Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin. Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Intrinsic Cell Stress is Independent of Organization in Engineered Cell Sheets.

PubMed

van Loosdregt, Inge A E W; Dekker, Sylvia; Alford, Patrick W; Oomens, Cees W J; Loerakker, Sandra; Bouten, Carlijn V C

2018-06-01

Understanding cell contractility is of fundamental importance for cardiovascular tissue engineering, due to its major impact on the tissue's mechanical properties as well as the development of permanent dimensional changes, e.g., by contraction or dilatation of the tissue. Previous attempts to quantify contractile cellular stresses mostly used strongly aligned monolayers of cells, which might not represent the actual organization in engineered cardiovascular tissues such as heart valves. In the present study, therefore, we investigated whether differences in organization affect the magnitude of intrinsic stress generated by individual myofibroblasts, a frequently used cell source for in vitro engineered heart valves. Four different monolayer organizations were created via micro-contact printing of fibronectin lines on thin PDMS films, ranging from strongly anisotropic to isotropic. Thin film curvature, cell density, and actin stress fiber distribution were quantified, and subsequently, intrinsic stress and contractility of the monolayers were determined by incorporating these data into sample-specific finite element models. Our data indicate that the intrinsic stress exerted by the monolayers in each group correlates with cell density. Additionally, after normalizing for cell density and accounting for differences in alignment, no consistent differences in intrinsic contractility were found between the different monolayer organizations, suggesting that the intrinsic stress exerted by individual myofibroblasts is independent of the organization. Consequently, this study emphasizes the importance of choosing proper architectural properties for scaffolds in cardiovascular tissue engineering, as these directly affect the stresses in the tissue, which play a crucial role in both the functionality and remodeling of (engineered) cardiovascular tissues.

Differential Contribution of Low- and High-level Image Content to Eye Movements in Monkeys and Humans.

PubMed

Wilming, Niklas; Kietzmann, Tim C; Jutras, Megan; Xue, Cheng; Treue, Stefan; Buffalo, Elizabeth A; König, Peter

2017-01-01

Oculomotor selection exerts a fundamental impact on our experience of the environment. To better understand the underlying principles, researchers typically rely on behavioral data from humans, and electrophysiological recordings in macaque monkeys. This approach rests on the assumption that the same selection processes are at play in both species. To test this assumption, we compared the viewing behavior of 106 humans and 11 macaques in an unconstrained free-viewing task. Our data-driven clustering analyses revealed distinct human and macaque clusters, indicating species-specific selection strategies. Yet, cross-species predictions were found to be above chance, indicating some level of shared behavior. Analyses relying on computational models of visual saliency indicate that such cross-species commonalities in free viewing are largely due to similar low-level selection mechanisms, with only a small contribution by shared higher level selection mechanisms and with consistent viewing behavior of monkeys being a subset of the consistent viewing behavior of humans. © The Author 2017. Published by Oxford University Press.

Differential Contribution of Low- and High-level Image Content to Eye Movements in Monkeys and Humans

PubMed Central

Wilming, Niklas; Kietzmann, Tim C.; Jutras, Megan; Xue, Cheng; Treue, Stefan; Buffalo, Elizabeth A.; König, Peter

2017-01-01

Abstract Oculomotor selection exerts a fundamental impact on our experience of the environment. To better understand the underlying principles, researchers typically rely on behavioral data from humans, and electrophysiological recordings in macaque monkeys. This approach rests on the assumption that the same selection processes are at play in both species. To test this assumption, we compared the viewing behavior of 106 humans and 11 macaques in an unconstrained free-viewing task. Our data-driven clustering analyses revealed distinct human and macaque clusters, indicating species-specific selection strategies. Yet, cross-species predictions were found to be above chance, indicating some level of shared behavior. Analyses relying on computational models of visual saliency indicate that such cross-species commonalities in free viewing are largely due to similar low-level selection mechanisms, with only a small contribution by shared higher level selection mechanisms and with consistent viewing behavior of monkeys being a subset of the consistent viewing behavior of humans. PMID:28077512

Two-Way Selection for Growth Rate in the Common Carp (CYPRINUS CARPIO L.)

PubMed Central

Moav, R.; Wohlfarth, G.

1976-01-01

The domesticated European carp was subjected to a two-way selection for growth rate. Five generations of mass selection for faster growth rate did not yield any response, but subsequent selection between groups (families) resulted in considerable progress while maintaining a large genetic variance. Selection for slow growth rate yielded relatively strong response for the first three generations. Random-bred control lines suffered from strong inbreeding depression and when two lines were crossed, the F1 showed a high degree of heterosis. Selection was performed on pond-raised fish, but growth rate was also tested in cages. A strong pond-cage genetic interaction was found. A theoretical explanation was suggested involving overdominance for fast growth rate and amplification through competition of intra-group but not inter-group variation. PMID:1248737

The effect of sexual selection on adaptation and extinction under increasing temperatures.

PubMed

Parrett, Jonathan M; Knell, Robert J

2018-04-25

Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, Plodia interpunctella, exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid. © 2018 The Author(s).

Mesenchymal Stromal Cell Secreted Sphingosine 1-Phosphate (S1P) Exerts a Stimulatory Effect on Skeletal Myoblast Proliferation

PubMed Central

Tani, Alessia; Anderloni, Giulia; Pierucci, Federica; Matteini, Francesca; Chellini, Flaminia; Zecchi Orlandini, Sandra; Meacci, Elisabetta

2014-01-01

Bone-marrow-derived mesenchymal stromal cells (MSCs) have the potential to significantly contribute to skeletal muscle healing through the secretion of paracrine factors that support proliferation and enhance participation of the endogenous muscle stem cells in the process of repair/regeneration. However, MSC-derived trophic molecules have been poorly characterized. The aim of this study was to investigate paracrine signaling effects of MSCs on skeletal myoblasts. It was found, using a biochemical and morphological approach that sphingosine 1-phosphate (S1P), a natural bioactive lipid exerting a broad range of muscle cell responses, is secreted by MSCs and represents an important factor by which these cells exert their stimulatory effects on C2C12 myoblast and satellite cell proliferation. Indeed, exposure to conditioned medium obtained from MSCs cultured in the presence of the selective sphingosine kinase inhibitor (iSK), blocked increased cell proliferation caused by the conditioned medium from untreated MSCs, and the addition of exogenous S1P in the conditioned medium from MSCs pre-treated with iSK further increased myoblast proliferation. Finally, we also demonstrated that the myoblast response to MSC-secreted vascular endothelial growth factor (VEGF) involves the release of S1P from C2C12 cells. Our data may have important implications in the optimization of cell-based strategies to promote skeletal muscle regeneration. PMID:25264785

Catechol-O-methyltransferase (COMT) polymorphisms modulate working memory in individuals with schizophrenia and healthy controls.

PubMed

Matsuzaka, Camila T; Christofolini, Denise; Ota, Vanessa K; Gadelha, Ary; Berberian, Arthur A; Noto, Cristiano; Mazzotti, Diego R; Spindola, Leticia M; Moretti, Patricia N; Smith, Marilia A C; Melaragno, Maria I; Belangero, Sintia I; Bressan, Rodrigo A

2017-01-01

Cognitive impairment is a core feature of schizophrenia, related to dopaminergic dysfunction in the prefrontal cortex (PFC). It is hypothesized that functional single nucleotide polymorphism (SNP) rs4680 of the catechol-O-methyltransferase (COMT) gene could mediate the relationship between cognition and dopamine activity in the PFC. Other COMT SNPs could also play a role. We evaluated the role of three COMT SNPs (rs737865, rs165599, and rs4680) in schizophrenia and their impact on three working memory tasks. For genetic association analyses, 212 individuals with schizophrenia and 257 healthy controls (HCs) were selected. The Visual Working Memory (VWM) Task, Keep Track Task, and Letter Memory Task were administered to 133 schizophrenics and 93 HCs. We found a significant association of rs737865, with the GG genotype exerting a protective effect and the GA haplotype (rs4680/rs165599) exerting a risk effect for schizophrenia. COMT rs4680 AA carriers and rs737865 AA carriers scored lowest on the Keep Track Task. When the genotype*group interaction effect was evaluated, rs165599 exerted opposite effects for VWM and Keep Track task performance in patients and controls, with AA carriers scoring lowest on both tests among controls, but highest among patients. These data support the hypothesis that COMT polymorphisms may be associated with schizophrenia and modulate cognition in patients and controls.

Pirfenidone exerts antifibrotic effects through inhibition of GLI transcription factors.

PubMed

Didiasova, Miroslava; Singh, Rajeev; Wilhelm, Jochen; Kwapiszewska, Grazyna; Wujak, Lukasz; Zakrzewicz, Dariusz; Schaefer, Liliana; Markart, Philipp; Seeger, Werner; Lauth, Matthias; Wygrecka, Malgorzata

2017-05-01

Pirfenidone is an antifibrotic drug, recently approved for the treatment of patients with idiopathic pulmonary fibrosis (IPF). Although pirfenidone exhibits anti-inflammatory, antioxidant, and antifibrotic properties, the molecular mechanism underlying its protective effects remains unknown. Here, we link pirfenidone action with the regulation of the profibrotic hedgehog (Hh) signaling pathway. We demonstrate that pirfenidone selectively destabilizes the glioma-associated oncogene homolog (GLI)2 protein, the primary activator of Hh-mediated gene transcription. Consequently, pirfenidone decreases overall Hh pathway activity in patients with IPF and in patient-derived primary lung fibroblasts and leads to diminished levels of Hh target genes, such as GLI1, Hh receptor Patched-1, α-smooth muscle actin, and fibronectin, and to reduced cell migration and proliferation. Interestingly, Hh-triggered TGF-β1 expression potentiated Hh responsiveness of primary lung fibroblasts by elevating the available pool of glioma-associated oncogene homolog (GLI)1/GLI2, thus creating a vicious cycle of amplifying fibrotic processes. Because GLI transcription factors are not only crucial for Hh-mediated changes but are also required as mediators of TGF-β signaling, our findings suggest that pirfenidone exerts its clinically beneficial effects through dual Hh/TGF-β inhibition by targeting the GLI2 protein.-Didiasova, M., Singh, R., Wilhelm, J., Kwapiszewska, G., Wujak, L., Zakrzewicz, D., Schaefer, L., Markart, P., Seeger, W., Lauth, M., Wygrecka, M. Pirfenidone exerts antifibrotic effects through inhibition of GLI transcription factors. © FASEB.

Additive antithrombotic effect of ASP6537, a selective cyclooxygenase (COX)-1 inhibitor, in combination with clopidogrel in guinea pigs.

PubMed

Sakata, Chinatsu; Suzuki, Ken-Ichi; Morita, Yoshiaki; Kawasaki, Tomihisa

2017-03-05

Clopidogrel (Plavix ® , Sanofi-Aventis), the adenosine diphosphate P2Y 12 receptor antagonist, is reported to be effective in the prevention of cardiovascular events and is often used in combination with aspirin, particularly in high-risk patients. ASP6537 is a reversible cyclooxygenase (COX)-1 inhibitor that is under investigation as an anti-platelet agent. First, we investigated the reversibility of the antiplatelet effect of ASP6537 and its interaction with ibuprofen to compare the usability of ASP6537 with that of aspirin. We then evaluated the antithrombotic effect of ASP6537 in combination with clopidogrel using a FeCl 3 -induced thrombosis model in guinea pigs. ASP6537 exerted reversible antiplatelet activity, and no pharmacodynamic interaction with ibuprofen was noted. When administered as monotherapy, ASP6537 exerted a significant antithrombotic effect at ≥3mg/kg, while aspirin inhibited thrombosis at 100mg/kg. ASP6537 exerted significant additive effects in combination with clopidogrel, and the minimum antithrombotic dose was reduced by concomitant administration of clopidogrel. Our study showed that ASP6537 did not interact with ibuprofen and has clear additive effects in combination with clopidogrel. ASP6537 may therefore represent a promising antiplatelet agent for use in clinical settings in combination with clopidogrel. Copyright © 2017 Elsevier B.V. All rights reserved.

"Turn Up the Taste": Assessing the Role of Taste Intensity and Emotion in Mediating Crossmodal Correspondences between Basic Tastes and Pitch.

PubMed

Wang, Qian Janice; Wang, Sheila; Spence, Charles

2016-05-01

People intuitively match basic tastes to sounds of different pitches, and the matches that they make tend to be consistent across individuals. It is, though, not altogether clear what governs such crossmodal mappings between taste and auditory pitch. Here, we assess whether variations in taste intensity influence the matching of taste to pitch as well as the role of emotion in mediating such crossmodal correspondences. Participants were presented with 5 basic tastants at 3 concentrations. In Experiment 1, the participants rated the tastants in terms of their emotional arousal and valence/pleasantness, and selected a musical note (from 19 possible pitches ranging from C2 to C8) and loudness that best matched each tastant. In Experiment 2, the participants made emotion ratings and note matches in separate blocks of trials, then made emotion ratings for all 19 notes. Overall, the results of the 2 experiments revealed that both taste quality and concentration exerted a significant effect on participants' loudness selection, taste intensity rating, and valence and arousal ratings. Taste quality, not concentration levels, had a significant effect on participants' choice of pitch, but a significant positive correlation was observed between individual perceived taste intensity and pitch choice. A significant and strong correlation was also demonstrated between participants' valence assessments of tastants and their valence assessments of the best-matching musical notes. These results therefore provide evidence that: 1) pitch-taste correspondences are primarily influenced by taste quality, and to a lesser extent, by perceived intensity; and 2) such correspondences may be mediated by valence/pleasantness. © The Author 2016. Published by Oxford University Press.

When the most potent combination of antibiotics selects for the greatest bacterial load: the smile-frown transition.

PubMed

Pena-Miller, Rafael; Laehnemann, David; Jansen, Gunther; Fuentes-Hernandez, Ayari; Rosenstiel, Philip; Schulenburg, Hinrich; Beardmore, Robert

2013-01-01

Conventional wisdom holds that the best way to treat infection with antibiotics is to 'hit early and hit hard'. A favoured strategy is to deploy two antibiotics that produce a stronger effect in combination than if either drug were used alone. But are such synergistic combinations necessarily optimal? We combine mathematical modelling, evolution experiments, whole genome sequencing and genetic manipulation of a resistance mechanism to demonstrate that deploying synergistic antibiotics can, in practice, be the worst strategy if bacterial clearance is not achieved after the first treatment phase. As treatment proceeds, it is only to be expected that the strength of antibiotic synergy will diminish as the frequency of drug-resistant bacteria increases. Indeed, antibiotic efficacy decays exponentially in our five-day evolution experiments. However, as the theory of competitive release predicts, drug-resistant bacteria replicate fastest when their drug-susceptible competitors are eliminated by overly-aggressive treatment. Here, synergy exerts such strong selection for resistance that an antagonism consistently emerges by day 1 and the initially most aggressive treatment produces the greatest bacterial load, a fortiori greater than if just one drug were given. Whole genome sequencing reveals that such rapid evolution is the result of the amplification of a genomic region containing four drug-resistance mechanisms, including the acrAB efflux operon. When this operon is deleted in genetically manipulated mutants and the evolution experiment repeated, antagonism fails to emerge in five days and antibiotic synergy is maintained for longer. We therefore conclude that unless super-inhibitory doses are achieved and maintained until the pathogen is successfully cleared, synergistic antibiotics can have the opposite effect to that intended by helping to increase pathogen load where, and when, the drugs are found at sub-inhibitory concentrations.

Metformin selectively affects human glioblastoma tumor-initiating cell viability: A role for metformin-induced inhibition of Akt.

PubMed

Würth, Roberto; Pattarozzi, Alessandra; Gatti, Monica; Bajetto, Adirano; Corsaro, Alessandro; Parodi, Alessia; Sirito, Rodolfo; Massollo, Michela; Marini, Cecilia; Zona, Gianluigi; Fenoglio, Daniela; Sambuceti, Gianmario; Filaci, Gilberto; Daga, Antonio; Barbieri, Federica; Florio, Tullio

2013-01-01

Cancer stem cell theory postulates that a small population of tumor-initiating cells is responsible for the development, progression and recurrence of several malignancies, including glioblastoma. In this perspective, tumor-initiating cells represent the most relevant target to obtain effective cancer treatment. Metformin, a first-line drug for type II diabetes, was reported to possess anticancer properties affecting the survival of cancer stem cells in breast cancer models. We report that metformin treatment reduced the proliferation rate of tumor-initiating cell-enriched cultures isolated from four human glioblastomas. Metformin also impairs tumor-initiating cell spherogenesis, indicating a direct effect on self-renewal mechanisms. Interestingly, analyzing by FACS the antiproliferative effects of metformin on CD133-expressing subpopulation, a component of glioblastoma cancer stem cells, a higher reduction of proliferation was observed as compared with CD133-negative cells, suggesting a certain degree of cancer stem cell selectivity in its effects. In fact, glioblastoma cell differentiation strongly reduced sensitivity to metformin treatment. Metformin effects in tumor-initiating cell-enriched cultures were associated with a powerful inhibition of Akt-dependent cell survival pathway, while this pathway was not affected in differentiated cells. The specificity of metformin antiproliferative effects toward glioblastoma tumor-initiating cells was confirmed by the lack of significant inhibition of normal human stem cells (umbilical cord-derived mesenchymal stem cells) in vitro proliferation after metformin exposure. Altogether, these data clearly suggest that metformin exerts antiproliferative activity on glioblastoma cells, showing a higher specificity toward tumor-initiating cells, and that the inhibition of Akt pathway may represent a possible intracellular target of this effect.

Fibroblast growth factor 2 restrains Ras-driven proliferation of malignant cells by triggering RhoA-mediated senescence.

PubMed

Costa, Erico T; Forti, Fábio L; Matos, Tatiana G F; Dermargos, Alexandre; Nakano, Fábio; Salotti, Jacqueline; Rocha, Kátia M; Asprino, Paula F; Yoshihara, Celina K; Koga, Marianna M; Armelin, Hugo A

2008-08-01

Fibroblast growth factor 2 (FGF2) is considered to be a bona fide oncogenic factor, although results from our group and others call this into question. Here, we report that exogenous recombinant FGF2 irreversibly inhibits proliferation by inducing senescence in Ras-dependent malignant mouse cells, but not in immortalized nontumorigenic cell lines. We report the following findings in K-Ras-dependent malignant Y1 adrenocortical cells and H-Ras V12-transformed BALB-3T3 fibroblasts: (a) FGF2 inhibits clonal growth and tumor onset in nude and immunocompetent BALB/c mice, (b) FGF2 irreversibly blocks the cell cycle, and (c) FGF2 induces the senescence-associated beta-galactosidase with no accompanying signs of apoptosis or necrosis. The tyrosine kinase inhibitor PD173074 completely protected malignant cells from FGF2. In Y1 adrenal cells, reducing the constitutively high levels of K-Ras-GTP using the dominant-negative RasN17 mutant made cells resistant to FGF2 cytotoxicity. In addition, transfection of the dominant-negative RhoA-N19 into either Y1 or 3T3-B61 malignant cell lines yielded stable clonal transfectants that were unable to activate RhoA and were resistant to the FGF2 stress response. We conclude that in Ras-dependent malignant cells, FGF2 interacts with its cognate receptors to trigger a senescence-like process involving RhoA-GTP. Surprisingly, attempts to select FGF2-resistant cells from the Y1 and 3T3-B61 cell lines yielded only rare clones that (a) had lost the overexpressed ras oncogene, (b) were dependent on FGF2 for proliferation, and (c) were poorly tumorigenic. Thus, FGF2 exerted a strong negative selection that Ras-dependent malignant cells could rarely overcome.

Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas

NASA Astrophysics Data System (ADS)

Ruiz-Rodríguez, Magdalena; Møller, Anders Pape; Mousseau, Timothy A.; Soler, Juan J.

2016-10-01

Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows ( Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense capacity against bacterial infections during the 30 years since the Chernobyl disaster.

Microbiological and toxicological effects of Perla black bean (Phaseolus vulgaris L.) extracts: in vitro and in vivo studies.

PubMed

Lara-Díaz, Víctor Javier; Gaytán-Ramos, Angel A; Dávalos-Balderas, Alfredo José; Santos-Guzmán, Jesús; Mata-Cárdenas, Benito David; Vargas-Villarreal, Javier; Barbosa-Quintana, Alvaro; Sanson, Misu; López-Reyes, Alberto Gabriel; Moreno-Cuevas, Jorge E

2009-02-01

We investigated the microbiological and toxicological effects of three Perla black bean extracts on the growth and culture of selected pathogenic microorganisms, the toxicity over Vero cell lines and an in vivo rat model. Three different solvents were used to obtain Perla black bean extracts. All three Perla black bean extracts were tested for antibacterial and antiparasitic activity and further analysed for intrinsic cytotoxicity (IC(50)). Methanol Perla black bean extract was used for acute toxicity test in rats, with the up-and-down doping method. All Perla black bean extracts inhibited bacterial growth. Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella oxytoca, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis and Listeria monocytogenes showed inhibition, while Escherichia coli and Enterobacter aerogenes did not. Acidified water and acetic acid Perla black bean extract were tested in parasites. The best IC(50) was observed for Giardia lamblia, while higher concentrations were active against Entamoeba histolytica and Trichomonas vaginalis. The Vero cells toxicity levels (IC(50)) for methanol, acidified water and acetic acid Perla black bean extract were [mean +/- S.D. (95% CI)]: 275 +/- 6.2 (267.9-282.0), 390 +/- 4.6 (384.8-395.2) and 209 +/- 3.39 (205.6-212.4) microg/ml, respectively. In vivo acute toxicity assays did not show changes in absolute organ weights, gross and histological examinations of selected tissues or functional tests. The acetic acid and methanol Perla black bean extract proved to exhibit strong antibacterial activity and the acidified water Perla black bean extract exerted parasiticidal effects against Giardia lamblia, Entamoeba hystolitica and Trichomonas vaginalis. The three Perla black bean extracts assayed over Vero cells showed very low toxicity and the methanol Perla black bean extract in vivo did not cause toxicity.

Ecotypic differences in the phenology of the tundra species Eriophorum vaginatum reflect sites of origin.

PubMed

Parker, Thomas C; Tang, Jianwu; Clark, Mahalia B; Moody, Michael M; Fetcher, Ned

2017-11-01

Eriophorum vaginatum is a tussock-forming sedge that contributes significantly to the structure and primary productivity of moist acidic tussock tundra. Locally adapted populations (ecotypes) have been identified across the geographical distribution of E. vaginatum ; however, little is known about how their growth and phenology differ over the course of a growing season. The growing season is short in the Arctic and therefore exerts a strong selection pressure on tundra species. This raises the hypothesis that the phenology of arctic species may be poorly adapted if the timing and length of the growing season change. Mature E. vaginatum tussocks from across a latitudinal gradient (65-70°N) were transplanted into a common garden at a central location (Toolik Lake, 68°38'N, 149°36'W) where half were warmed using open-top chambers. Over two growing seasons (2015 and 2016), leaf length was measured weekly to track growth rates, timing of senescence, and biomass accumulation. Growth rates were similar across ecotypes and between years and were not affected by warming. However, southern populations accumulated significantly more biomass, largely because they started to senesce later. In 2016, peak biomass and senescence of most populations occurred later than in 2015, probably induced by colder weather at the beginning of the growing season in 2016, which caused a delayed start to growth. The finish was delayed as well. Differences in phenology between populations were largely retained between years, suggesting that the amount of time that these ecotypes grow has been selected by the length of the growing seasons at their respective home sites. As potential growing seasons lengthen, E. vaginatum may be unable to respond appropriately as a result of genetic control and may have reduced fitness in the rapidly warming Arctic tundra.

“Turn Up the Taste”: Assessing the Role of Taste Intensity and Emotion in Mediating Crossmodal Correspondences between Basic Tastes and Pitch

PubMed Central

Wang, Sheila; Spence, Charles

2016-01-01

People intuitively match basic tastes to sounds of different pitches, and the matches that they make tend to be consistent across individuals. It is, though, not altogether clear what governs such crossmodal mappings between taste and auditory pitch. Here, we assess whether variations in taste intensity influence the matching of taste to pitch as well as the role of emotion in mediating such crossmodal correspondences. Participants were presented with 5 basic tastants at 3 concentrations. In Experiment 1, the participants rated the tastants in terms of their emotional arousal and valence/pleasantness, and selected a musical note (from 19 possible pitches ranging from C2 to C8) and loudness that best matched each tastant. In Experiment 2, the participants made emotion ratings and note matches in separate blocks of trials, then made emotion ratings for all 19 notes. Overall, the results of the 2 experiments revealed that both taste quality and concentration exerted a significant effect on participants’ loudness selection, taste intensity rating, and valence and arousal ratings. Taste quality, not concentration levels, had a significant effect on participants’ choice of pitch, but a significant positive correlation was observed between individual perceived taste intensity and pitch choice. A significant and strong correlation was also demonstrated between participants’ valence assessments of tastants and their valence assessments of the best-matching musical notes. These results therefore provide evidence that: 1) pitch–taste correspondences are primarily influenced by taste quality, and to a lesser extent, by perceived intensity; and 2) such correspondences may be mediated by valence/pleasantness. PMID:26873934

Strategies of zooplanktivory shape the dynamics and diversity of littoral plankton communities: a mesocosm approach

PubMed Central

Helenius, Laura K; Aymà Padrós, Anna; Leskinen, Elina; Lehtonen, Hannu; Nurminen, Leena

2015-01-01

Planktivorous fish can exert strong top-down control on zooplankton communities. By incorporating different feeding strategies, from selective particulate feeding to cruising filter feeding, fish species target distinct prey. In this study, we investigated the effects of two species with different feeding strategies, the three-spined stickleback (Gasterosteus aculeatus (L.)) and roach (Rutilus rutilus (L.)), on a low-diversity brackish water zooplankton community using a 16-day mesocosm experiment. The experiment was conducted on a small-bodied spring zooplankton community in high-nutrient conditions, as well as a large-bodied summer community in low-nutrient conditions. Effects were highly dependent on the initial zooplankton community structure and hence seasonal variation. In a small-bodied community with high predation pressure and no dispersal or migration, the selective particulate-feeding stickleback depleted the zooplankton community and decreased its diversity more radically than the cruising filter-feeding roach. Cladocerans rather than copepods were efficiently removed by predation, and their removal caused altered patterns in rotifer abundance. In a large-bodied summer community with initial high taxonomic and functional diversity, predation pressure was lower and resource availability was high for omnivorous crustaceans preying on other zooplankton. In this community, predation maintained diversity, regardless of predator species. During both experimental periods, predation influenced the competitive relationship between the dominant calanoid copepods, and altered species composition and size structure of the zooplankton community. Changes also occurred to an extent at the level of nontarget prey, such as microzooplankton and rotifers, emphasizing the importance of subtle predation effects. We discuss our results in the context of the adaptive foraging mechanism and relate them to the natural littoral community. PMID:26045953

Defenses against keratinolytic bacteria in birds living in radioactively contaminated areas.

PubMed

Ruiz-Rodríguez, Magdalena; Møller, Anders Pape; Mousseau, Timothy A; Soler, Juan J

2016-10-01

Microorganisms have shaped the evolution of a variety of defense mechanisms against pathogenic infections. Radioactivity modifies bacterial communities and, therefore, bird hosts breeding in contaminated areas are expected to adapt to the new bacterial environment. We tested this hypothesis in populations of barn swallows (Hirundo rustica) from a gradient of background radiation levels at Chernobyl and uncontaminated controls from Denmark. Investment in defenses against keratinolytic bacteria was measured from feather structure (i.e., susceptibility to degradation) and uropygial secretions. We studied degradability of tail feathers from areas varying in contamination in laboratory experiments using incubation of feathers with a feather-degrading bacterium, Bacillus licheniformis, followed by measurement of the amount of keratin digested. The size of uropygial glands and secretion amounts were quantified, followed by antimicrobial tests against B. licheniformis and quantification of wear of feathers. Feathers of males, but not of females, from highly contaminated areas degraded at a lower rate than those from medium and low contamination areas. However, feathers of both sexes from the Danish populations showed little evidence of degradation. Individual barn swallows from the more contaminated areas of Ukraine produced the largest uropygial secretions with higher antimicrobial activity, although wear of feathers did not differ among males from different populations. In Denmark, swallows produced smaller quantities of uropygial secretion with lower antimicrobial activity, which was similar to swallow populations from uncontaminated areas in Ukraine. Therefore, barn swallows breeding in contaminated areas invested more in all defenses against keratinolytic bacteria than in uncontaminated areas of Ukraine and Denmark, although they had similar levels of feather wear. Strong natural selection exerted by radioactivity may have selected for individuals with higher defense capacity against bacterial infections during the 30 years since the Chernobyl disaster.

An in vitro examination of the antioxidant and anti-inflammatory properties of buckwheat honey.

PubMed

van den Berg, A J J; van den Worm, E; van Ufford, H C Quarles; Halkes, S B A; Hoekstra, M J; Beukelman, C J

2008-04-01

Hydroxyl radical and hypochlorite anion formed at the wound site from superoxide anion produced by activated polymorphonuclear neutrophils (PMNs) are considered important factors in impaired wound healing. Superoxide anion may also react with nitric oxide produced by macrophages to form peroxynitrite, a third strong oxidant that damages surrounding tissue. In order to select honey for use in wound-healing products, different samples were compared for their capacity to reduce levels of reactive oxygen species (ROS) in vitro. Honey samples were tested in assays for inhibition of ROS production by activated human PMNs, antioxidant activity (scavenging of superoxide anion in a cell-free system) and inhibition of human complement (reducing levels of ROS by limiting formation of complement factors that attract and stimulate PMNs). For buckwheat honey (NewYork, US), moisture and free acid content were determined by refractive index measurement and potentiometric titration respectively. Honey constituents other than sugars were investigated by thin layer chromatography, using natural product reagent to detect phenolic compounds. Constituents with antioxidant properties were detected by spraying the chromatogram with DPPH. Although most honey samples were shown to be active, significant differences were observed, with the highly active honey exceeding the activities of samples with minor effects by factors of 4 to 30. Most pronounced activities were found for American buckwheat honey from the state of NewYork. Phenolic constituents of buckwheat honey were shown to have antioxidant activity. As buckwheat honey was most effective in reducing ROS levels, it was selected for use in wound-healing products. The major antioxidant properties in buckwheat honey derive from its phenolic constituents, which are present in relatively large amounts. Its phenolic compounds may also exert antibacterial activity, whereas its low pH and high free acid content may assist wound healing.

Exertion Testing in Youth with Mild Traumatic Brain Injury/Concussion.

PubMed

Dematteo, Carol; Volterman, Kimberly A; Breithaupt, Peter G; Claridge, Everett A; Adamich, John; Timmons, Brian W

2015-11-01

The decision regarding return to activity (RTA) after mild traumatic brain injuries/concussion is one of the most difficult and controversial areas in concussion management, particularly for youth. This study investigated how youth with postconcussion syndrome (PCS) are affected by exertion and whether standardized exertion testing using the McMaster All-Out Progressive Continuous Cycling Test can contribute to clinical decision making for safe RTA. Fifty-four youth (8.5-18.3 yr) with a previously confirmed concussion participated in the study. Each participant performed exertion testing on a cycle ergometer and completed a Postconcussion Symptom scale at the following time points: before exertion (baseline), 5 and 30 min, and 24 h after exertion. A modified Postconcussion Symptom scale was administered at 2-min intervals during exertion. Participants had a mean ± SD symptom duration of 6.3 ± 6.9 months after the most recent concussive injury, with a median of 4.1 months (range, 0.7-35 months). Sixty-three percent of participants had symptoms during exertion testing. Symptom profile (number and severity) significantly affected perception of exertion at 50% peak mechanical power. During acute assessment of symptoms (30-min after exertion), headache (P = 0.39), nausea (P = 0.63), and dizziness (P = 0.35) did not change. However, both the number and severity of symptoms significantly improved over 24 h, with 56.8% of youth showing improvements. The time from the most recent injury had a significant effect on the symptom score at baseline, 30 min after exertion, and 24 h after exertion. Exertion testing has an important role in the evaluation of symptoms and readiness to RTA, particularly in youth who are slow to recover. Overall, controlled exertion seemed to lesson symptoms for most youth.

Correlates of healthcare and financial decision making among older adults without dementia.

PubMed

Stewart, Christopher C; Yu, Lei; Wilson, Robert S; Bennett, David A; Boyle, Patricia A

2018-03-22

Healthcare and financial decision making among older persons has been previously associated with cognition, health and financial literacy, and risk aversion; however, the manner by which these resources support decision making remains unclear, as past studies have not systematically investigated the pathways linking these resources with decision making. In the current study, we use path analysis to examine the direct and indirect pathways linking age, education, cognition, literacy, and risk aversion with decision making. We also decomposed literacy into its subcomponents, conceptual knowledge and numeracy, in order to examine their associations with decision making. Participants were 937 community-based older adults without dementia from the Rush Memory and Aging Project who completed a battery of cognitive tests and assessments of healthcare and financial decision making, health and financial literacy, and risk aversion. Age and education exerted effects on decision making, but nearly two thirds of their effects were indirect, working mostly through cognition and literacy. Cognition exerted a strong direct effect on decision making and a robust indirect effect working primarily through literacy. Literacy also exerted a powerful direct effect on decision making, as did its subcomponents, conceptual knowledge and numeracy. The direct effect of risk aversion was comparatively weak. In addition to cognition, health and financial literacy emerged as independent and primary correlates of healthcare and financial decision making. These findings suggest specific actions that might be taken to optimize healthcare and financial decision making and, by extension, improve health and well-being in advanced age. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Food safety concerns deriving from the use of silver based food packaging materials.

PubMed

Pezzuto, Alessandra; Losasso, Carmen; Mancin, Marzia; Gallocchio, Federica; Piovesana, Alessia; Binato, Giovanni; Gallina, Albino; Marangon, Alberto; Mioni, Renzo; Favretti, Michela; Ricci, Antonia

2015-01-01

The formulation of innovative packaging solutions, exerting a functional antimicrobial role in slowing down food spoilage, is expected to have a significant impact on the food industry, allowing both the maintenance of food safety criteria for longer periods and the reduction of food waste. Different materials are considered able to exert the required antimicrobial activity, among which are materials containing silver. However, challenges exist in the application of silver to food contact materials due to knowledge gaps in the production of ingredients, stability of delivery systems in food matrices and health risks caused by the same properties which also offer the benefits. Aims of the present study were to test the effectiveness and suitability of two packaging systems, one of which contained silver, for packaging and storing Stracchino cheese, a typical Italian fresh cheese, and to investigate if there was any potential for consumers to be exposed to silver, via migration from the packaging to the cheese. Results did not show any significant difference in the effectiveness of the packaging systems on packaged Stracchino cheese, excluding that the active packaging systems exerted an inhibitory effect on the growth of spoilage microorganisms. Moreover, silver migrated into the cheese matrix throughout the storage time (24 days). Silver levels in cheese finally exceeded the maximum established level for the migration of a non-authorised substance through a functional barrier (Commission of the European Communities, 2009). This result poses safety concerns and strongly suggests the need for more research aimed at better characterizing the new packaging materials in terms of their potential impacts on human health and the environment.

Nano-Encrypted Morse Code: A Versatile Approach to Programmable and Reversible Nanoscale Assembly and Disassembly

PubMed Central

Wong, Ngo Yin; Xing, Hang; Tan, Li Huey; Lu, Yi

2013-01-01

While much work has been devoted to nanoscale assembly of functional materials, selective reversible assembly of components in the nanoscale pattern at selective sites has received much less attention. Exerting such a reversible control of the assembly process will make it possible to fine-tune the functional properties of the assembly and to realize more complex designs. Herein, by taking advantage of different binding affinities of biotin and desthiobiotin toward streptavidin, we demonstrate selective and reversible decoration of DNA origami tiles with streptavidin, including revealing an encrypted Morse code “NANO” and reversible exchange of uppercase letter “I” with lowercase “i”. The yields of the conjugations are high (> 90%) and the process is reversible. We expect this versatile conjugation technique to be widely applicable with different nanomaterials and templates. PMID:23373425

Selecting Design Parameters for Flying Vehicles

NASA Astrophysics Data System (ADS)

Makeev, V. I.; Strel'nikova, E. A.; Trofimenko, P. E.; Bondar', A. V.

2013-09-01

Studying the influence of a number of design parameters of solid-propellant rockets on the longitudinal and lateral dispersion is an important applied problem. A mathematical model of a rigid body of variable mass moving in a disturbed medium exerting both wave drag and friction is considered. The model makes it possible to determine the coefficients of aerodynamic forces and moments, which affect the motion of vehicles, and to assess the effect of design parameters on their accuracy

Context Aware TCP for Intelligence, Surveillance and Reconnaissance Missions on Autonomous Platforms

DTIC Science & Technology

2014-10-08

under the Unmanned Vehicle Experimental Communications Testbed (UVECT) flight test plan and were done over the Stockbridge Research Facility in the...sure the payload did not interfere with the command and control systems of the aircraft several flight paths were selected to exert the link and the...throughput from data source to destination. Figure 1 shows the flight path of a small RPA in a PoL flight path scenario. The change of SNR

Applying the Combinatorial Retention Auction Mechanism (CRAM) to a Cost-Benefit Analysis of the Post 9/11 Era GI Bill Transferability Benefit

DTIC Science & Technology

2009-06-01

impacts, services have to exert more pressure on the recruiting market and boost Selective Reenlistment Bonuses (SRB) for individuals in critically ...which are used as incentives to recruit high quality recruits into critically undermanned occupations. 11 12 Credit hours per semester. 9  Total...perception about their own personal educational opportunities seems critical . The challenge at this point is to quantify how much transferring a

Isotope signatures in winter moulted feathers predict malaria prevalence in a breeding avian host.

PubMed

Yohannes, Elizabeth; Hansson, Bengt; Lee, Raymond W; Waldenström, Jonas; Westerdahl, Helena; Akesson, Mikael; Hasselquist, Dennis; Bensch, Staffan

2008-11-01

It is widely accepted that animal distribution and migration strategy might have co-evolved in relation to selection pressures exerted by parasites. Here, we first determined the prevalence and types of malaria blood parasites in a breeding population of great reed warblers Acrocephalus arundinaceus using PCR. Secondly, we tested for differences in individual feather stable isotope signatures (delta (13)C, delta (15)N, deltaD and delta (34)S) to investigate whether malaria infected and non-infected birds had occupied different areas in winter. We show that birds moulting in Afro-tropical habitats with significantly higher delta (13)C and delta (15)N but lower deltaD and delta(34)S values were more frequently infected with malaria parasites. Based on established patterns of isotopic distributions, our results indicate that moulting sites with higher incidence of malaria are generally drier and situated further to the north in West Africa than sites with lower incidence of malaria. Our findings are pertinent to the general hypothesis that animal distribution and particularly avian migration strategy might evolve in response to selection pressures exerted by parasites at different geographic scales. Tradeoffs between investment in energy demanding life history traits (e.g. migration and winter moult) and immune function are suggested to contribute to the particular choice of habitat during migration and at wintering sites.

Bacterial selection by mycospheres of Atlantic Rainforest mushrooms.

PubMed

Halsey, Joshua Andrew; de Cássia Pereira E Silva, Michele; Andreote, Fernando Dini

2016-10-01

This study focuses on the selection exerted on bacterial communities in the mycospheres of mushrooms collected in the Brazilian Atlantic Rainforest. A total of 24 paired samples (bulk soil vs. mycosphere) were assessed to investigate potential interactions between fungi and bacteria present in fungal mycospheres. Prevalent fungal families were identified as Marasmiaceae and Lepiotaceae (both Basidiomycota) based on ITS partial sequencing. We used culture-independent techniques to analyze bacterial DNA from soil and mycosphere samples. Bacterial communities in the samples were distinguished based on overall bacterial, alphaproteobacterial, and betaproteobacterial PCR-DGGE patterns, which were different in fungi belonging to different taxa. These results were confirmed by pyrosequencing the V4 region of the 16S rRNA gene (based on five bulk soil vs. mycosphere pairs), which revealed the most responsive bacterial families in the different conditions generated beneath the mushrooms, identified as Bradyrhizobiaceae, Burkholderiaceae, and Pseudomonadaceae. The bacterial families Acetobacteraceae, Chrhoniobacteraceae, Planctomycetaceae, Conexibacteraceae, and Burkholderiaceae were found in all mycosphere samples, composing the core mycosphere microbiome. Similarly, some bacterial groups identified as Koribacteriaceae, Acidobacteria (Solibacteriaceae) and an unclassified group of Acidobacteria were preferentially present in the bulk soil samples (found in all of them). In this study we depict the mycosphere effect exerted by mushrooms inhabiting the Brazilian Atlantic Rainforest, and identify the bacteria with highest response to such a specific niche, possibly indicating the role bacteria play in mushroom development and dissemination within this yet-unexplored environment.

In vitro colonic metabolism of coffee and chlorogenic acid results in selective changes in human faecal microbiota growth.

PubMed

Mills, Charlotte E; Tzounis, Xenofon; Oruna-Concha, Maria-Jose; Mottram, Don S; Gibson, Glenn R; Spencer, Jeremy P E

2015-04-28

Coffee is a relatively rich source of chlorogenic acids (CGA), which, as other polyphenols, have been postulated to exert preventive effects against CVD and type 2 diabetes. As a considerable proportion of ingested CGA reaches the large intestine, CGA may be capable of exerting beneficial effects in the large gut. Here, we utilise a stirred, anaerobic, pH-controlled, batch culture fermentation model of the distal region of the colon in order to investigate the impact of coffee and CGA on the growth of the human faecal microbiota. Incubation of coffee samples with the human faecal microbiota led to the rapid metabolism of CGA (4 h) and the production of dihydrocaffeic acid and dihydroferulic acid, while caffeine remained unmetabolised. The coffee with the highest levels of CGA (P<0·05, relative to the other coffees) induced a significant increase in the growth of Bifidobacterium spp. relative to the control vessel at 10 h after exposure (P<0·05). Similarly, an equivalent quantity of CGA (80·8 mg, matched with that in high-CGA coffee) induced a significant increase in the growth of Bifidobacterium spp. (P<0·05). CGA alone also induced a significant increase in the growth of the Clostridium coccoides-Eubacterium rectale group (P<0·05). This selective metabolism and subsequent amplification of specific bacterial populations could be beneficial to host health.

Does energy consumption contribute to environmental pollutants? Evidence from SAARC countries.

PubMed

Akhmat, Ghulam; Zaman, Khalid; Shukui, Tan; Irfan, Danish; Khan, Muhammad Mushtaq

2014-05-01

The objective of the study is to examine the causal relationship between energy consumption and environmental pollutants in selected South Asian Association for Regional Cooperation (SAARC) countries, namely, Bangladesh, India, Nepal, Pakistan, and Srilanka, over the period of 1975-2011. The results indicate that energy consumption acts as an important driver to increase environmental pollutants in SAARC countries. Granger causality runs from energy consumption to environmental pollutants, but not vice versa, except carbon dioxide (CO2) emissions in Nepal where there exists a bidirectional causality between CO2 and energy consumption. Methane emissions in Bangladesh, Pakistan, and Srilanka and extreme temperature in India and Srilanka do not Granger cause energy consumption via both routes, which holds neutrality hypothesis. Variance decomposition analysis shows that among all the environmental indicators, CO2 in Bangladesh and Nepal exerts the largest contribution to changes in electric power consumption. Average precipitation in India, methane emissions in Pakistan, and extreme temperature in Srilanka exert the largest contribution.

The interactions of multisensory integration with endogenous and exogenous attention

PubMed Central

Tang, Xiaoyu; Wu, Jinglong; Shen, Yong

2016-01-01

Stimuli from multiple sensory organs can be integrated into a coherent representation through multiple phases of multisensory processing; this phenomenon is called multisensory integration. Multisensory integration can interact with attention. Here, we propose a framework in which attention modulates multisensory processing in both endogenous (goal-driven) and exogenous (stimulus-driven) ways. Moreover, multisensory integration exerts not only bottom-up but also top-down control over attention. Specifically, we propose the following: (1) endogenous attentional selectivity acts on multiple levels of multisensory processing to determine the extent to which simultaneous stimuli from different modalities can be integrated; (2) integrated multisensory events exert top-down control on attentional capture via multisensory search templates that are stored in the brain; (3) integrated multisensory events can capture attention efficiently, even in quite complex circumstances, due to their increased salience compared to unimodal events and can thus improve search accuracy; and (4) within a multisensory object, endogenous attention can spread from one modality to another in an exogenous manner. PMID:26546734

GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters.

PubMed

Ramesh, Sunita A; Tyerman, Stephen D; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A; Ryan, Peter R; Gilliham, Matthew; Gillham, Matthew

2015-07-29

The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters

PubMed Central

Ramesh, Sunita A.; Tyerman, Stephen D.; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A.; Ryan, Peter R.; Gillham, Matthew

2015-01-01

The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms. PMID:26219411

Let's Walk Outdoors! Self-Paced Walking Outdoors Improves Future Intention to Exercise in Women With Obesity.

PubMed

Krinski, Kleverton; Machado, Daniel G S; Lirani, Luciana S; DaSilva, Sergio G; Costa, Eduardo C; Hardcastle, Sarah J; Elsangedy, Hassan M

2017-04-01

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle.

The interactions of multisensory integration with endogenous and exogenous attention.

PubMed

Tang, Xiaoyu; Wu, Jinglong; Shen, Yong

2016-02-01

Stimuli from multiple sensory organs can be integrated into a coherent representation through multiple phases of multisensory processing; this phenomenon is called multisensory integration. Multisensory integration can interact with attention. Here, we propose a framework in which attention modulates multisensory processing in both endogenous (goal-driven) and exogenous (stimulus-driven) ways. Moreover, multisensory integration exerts not only bottom-up but also top-down control over attention. Specifically, we propose the following: (1) endogenous attentional selectivity acts on multiple levels of multisensory processing to determine the extent to which simultaneous stimuli from different modalities can be integrated; (2) integrated multisensory events exert top-down control on attentional capture via multisensory search templates that are stored in the brain; (3) integrated multisensory events can capture attention efficiently, even in quite complex circumstances, due to their increased salience compared to unimodal events and can thus improve search accuracy; and (4) within a multisensory object, endogenous attention can spread from one modality to another in an exogenous manner. Copyright © 2015 Elsevier Ltd. All rights reserved.

Darwin on woman.

PubMed

Cohen, Claudine

2010-02-01

In his 1871 book The Descent of Man, Darwin exposed the idea of sexual selection as a major principle of human evolution. His main hypothesis, which was already briefly presented in The Origin of Species, is that there exists, besides "natural selection", another form of selection, milder in its effect, but no less efficient. This selection is operated by females to mate and reproduce with some partners that are gifted with more qualities than others, and more to their taste. At more evolved stages, sexual selection was exerted by men who became able to choose the women most attractive to their taste. However, Darwin insists, sexual selection in the human species is limited by a certain number of cultural practices. If Darwin's demonstration sometimes carried the prejudices of his times regarding gender differences he was the first who took into account the importance of sexual choices in his view on evolution, and who insisted on the evolutionary role of women at the dawn of humanity. Thus, he opened the space for a rich reflection, which after him was widely developed and discussed in anthropological and gender studies. 2010. Published by Elsevier SAS.

There is more to pollinator-mediated selection than pollen limitation.

PubMed

Sletvold, Nina; Agren, Jon

2014-07-01

Spatial variation in pollinator-mediated selection (Δβpoll ) is a major driver of floral diversification, but we lack a quantitative understanding of its link to pollen limitation (PL) and net selection on floral traits. For 2-5 years, we quantified Δβpoll on floral traits in two populations each of two orchid species differing in PL. In both species, spatiotemporal variation in Δβpoll explained much of the variation in net selection. Selection was consistently stronger and the proportion that was pollinator-mediated was higher in the severely pollen-limited deceptive species than in the rewarding species. Within species, variation in PL could not explain variation in Δβpoll for any trait, indicating that factors influencing the functional relationship between trait variation and pollination success govern a major part of the observed variation in Δβpoll . Separating the effects of variation in mean interaction intensity and in the functional significance of traits will be necessary to understand spatiotemporal variation in selection exerted by the biotic environment. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Hitler: a neurohistorical formulation.

PubMed

Martindale, C; Hasenfus, N; Hines, D

1976-01-01

It is hypothesized that Adolf Hitler suffered from a constitutional left-side weakness that allowed his cerebral hemisphere to exert a strong influence on his thought and behavior. Physical characteristics such as trembling of the left extremities, lack of a left testicle, and tendency to exhibit leftward eye movements are interpreted as supportive of the hypothesis. Right hemisphere dominance is consistent with a number of Hitler's personal traits such as praise of the irrational, automatic speech, auditory hallucinations, hypochondriasis, uncontrolled rages, and spatial and musical interests. Right hemisphere dominated thought may also have formed a basis for his two basic political policies: Lebensraum and anti-Semitism.

Surge dynamics coupled to pore-pressure evolution in debris flows

USGS Publications Warehouse

Savage, S.B.; Iverson, R.M.; ,

2003-01-01

Temporally and spatially varying pore-fluid pressures exert strong controls on debris-flow motion by mediating internal and basal friction at grain contacts. We analyze these effects by deriving a one-dimensional model of pore-pressure diffusion explicitly coupled to changes in debris-flow thickness. The new pore-pressure equation is combined with Iverson's (1997) extension of the depth-averaged Savage-Hutter (1989, 1991) granular avalanche equations to predict motion of unsteady debris-flow surges with evolving pore-pressure distributions. Computational results illustrate the profound effects of pore-pressure diffusivities on debris-flow surge depths and velocities. ?? 2003 Millpress,.

Feeling connected to younger versus older selves: the asymmetric impact of life stage orientation.

PubMed

O'Brien, Ed

2015-01-01

The concept of life-stage orientation is proposed. Youth is a period of time characterised by strong feelings and emotions, but weak reasoning and cognitive skill. Conversely, adulthood is characterised by strong rationality, but weak emotionality. Two studies revealed that merely bringing these concepts to mind changes real-time feelings and behaviour. Participants who were instructed to act like their "adult" selves exhibited greater self-control in a cold pressor test than control participants and those who acted like their "youth" selves (Experiment 1). However, being induced to feel connected to youth enhanced enjoyment for fun videos (Experiment 2). Hence, the extent to which people are oriented towards youth versus adulthood has asymmetric costs and benefits for the present. Connecting to youth boosts experiential capacities (in this case, enjoying oneself) at the cost of agency, whereas connecting to adulthood boosts agentic capacities (in this case, exerting will-power) at the cost of experience.

Structural basis for the antifolding activity of a molecular chaperone

NASA Astrophysics Data System (ADS)

Huang, Chengdong; Rossi, Paolo; Saio, Tomohide; Kalodimos, Charalampos G.

2016-09-01

Molecular chaperones act on non-native proteins in the cell to prevent their aggregation, premature folding or misfolding. Different chaperones often exert distinct effects, such as acceleration or delay of folding, on client proteins via mechanisms that are poorly understood. Here we report the solution structure of SecB, a chaperone that exhibits strong antifolding activity, in complex with alkaline phosphatase and maltose-binding protein captured in their unfolded states. SecB uses long hydrophobic grooves that run around its disk-like shape to recognize and bind to multiple hydrophobic segments across the length of non-native proteins. The multivalent binding mode results in proteins wrapping around SecB. This unique complex architecture alters the kinetics of protein binding to SecB and confers strong antifolding activity on the chaperone. The data show how the different architectures of chaperones result in distinct binding modes with non-native proteins that ultimately define the activity of the chaperone.

The Effect of Ozone on Colonic Epithelial Cells.

PubMed

Himuro, Hidetomo

2018-05-21

Due to its strong oxidation activity, ozone has been well known to kill bacteria and exert toxic effects on human tissues. At the same time, ozone is being used for the treatment of diseases such as inflammatory bowel disease in some European countries. However, the use of ozone for therapeutic purposes, despite its strong toxic effects, remains largely unexplored. Interestingly, we found that intrarectal administration of ozone gas induced transient colonic epithelial cell damage characterized by the impairment of cell survival pathways involved in DNA replication, cell cycle, and mismatch repair. However, the damaged cells were rapidly extruded from the epithelial layer, and appeared to immediately stimulate turnover of the epithelial layer in the colon. Therefore, it is possible that ozone gas is able to trigger damage-induced rapid regeneration of intestinal epithelial cells, and that this explains why ozone does not cause harmful or persistent damage in the colon.

Strong terahertz emission by optical rectification of shaped laser pulse in transversely magnetized plasma

NASA Astrophysics Data System (ADS)

Singh, Ram Kishor; Singh, Monika; Rajouria, Satish Kumar; Sharma, R. P.

2017-07-01

This communication presents a theoretical model for efficient terahertz (THz) radiation generation by the optical rectification of shaped laser pulse in transversely magnetised ripple density plasma. The laser beam imparts a nonlinear ponderomotive force to the electron and this force exerts a nonlinear velocity component in both transverse and axial directions which have spectral components in the THz range. These velocity components couple with the pre-existing density ripple and give rise to a strong nonlinear current density which drives the THz wave in the plasma. The THz yield increases with the increasing strength of the background magnetic field and the sensitivity depends on the ripple wave number. The emitted power is directly proportional to the square of the amplitude of the density ripple. For exact phase matching condition, the normalised power of the generated THz wave can be achieved of the order of 10-4.

Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions.

PubMed

Kalmár, József; Dóka, Éva; Lente, Gábor; Fábián, István

2014-03-28

The aqueous photoreactions of three halide ions (chloride, bromide and iodide) were studied using a diode array spectrophotometer to drive and detect the process at the same time. The concentration and pH dependences of the halogen formation rates were studied in detail. The experimental data were interpreted by improving earlier models where the cage complex of a halogen atom and an electron has a central role. The triiodide ion was shown to exert a strong inhibiting effect on the reaction sequence leading to its own formation. An assumed chemical reaction between the triiodide ion and the cage complex interpreted the strong autoinhibition effect. It is shown that there is a real danger of unwanted interference from the photoreactions of halide ions when halide salts are used as supporting electrolytes in spectrophotometric experiments using a relatively high intensity UV light source.

Restoring the order: gender segregation as an obstacle to organisational development.

PubMed

Abrahamsson, Lena

2002-11-01

This paper raises questions about the links between gender and organisational changes. The empirical base for the discussion is a qualitative study of the effects of organisational changes in the pulp and paper industry, the electronics industry, the food industry and the laundry industry in Sweden during the mid-1990s. At the studied companies, restoration responses in the work organisations brought the organisation back into its original form and function. The study shows that gender exerts an influence both on the existing work organisation and in the organisational change. The modern organisation, with its focus on integration and decentralisation, challenges the gender order, which is a strong system, built on segregation and hierarchy. The conclusion from the study is that gender segregating and stereotypic gender-coding of workplaces and work tasks were strong restoring mechanisms and obstacles to strategic organisational changes.

Sucralose Destabilization of Protein Structure.

PubMed

Chen, Lee; Shukla, Nimesh; Cho, Inha; Cohn, Erin; Taylor, Erika A; Othon, Christina M

2015-04-16

Sucralose is a commonly employed artificial sweetener that behaves very differently than its natural disaccharide counterpart, sucrose, in terms of its interaction with biomolecules. The presence of sucralose in solution is found to destabilize the native structure of two model protein systems: the globular protein bovine serum albumin and an enzyme staphylococcal nuclease. The melting temperature of these proteins decreases as a linear function of sucralose concentration. We correlate this destabilization to the increased polarity of the molecule. The strongly polar nature is manifested as a large dielectric friction exerted on the excited-state rotational diffusion of tryptophan using time-resolved fluorescence anisotropy. Tryptophan exhibits rotational diffusion proportional to the measured bulk viscosity for sucrose solutions over a wide range of concentrations, consistent with a Stokes-Einstein model. For sucralose solutions, however, the diffusion is dependent on the concentration, strongly diverging from the viscosity predictions, and results in heterogeneous rotational diffusion.

The metabolic perturbators metformin, phenformin and AICAR interfere with the growth and survival of murine PTEN-deficient T cell lymphomas and human T-ALL/T-LL cancer cells.

PubMed

Rosilio, Célia; Lounnas, Nadia; Nebout, Marielle; Imbert, Véronique; Hagenbeek, Thijs; Spits, Hergen; Asnafi, Vahid; Pontier-Bres, Rodolphe; Reverso, Julie; Michiels, Jean-François; Sahra, Issam Ben; Bost, Fréderic; Peyron, Jean-François

2013-08-09

We show here that the antidiabetic agents metformin and phenformin and the AMPK activator AICAR exert strong anti-tumoural effects on tPTEN-/- lymphoma cells and on human T-ALL cell lines and primary samples. The compounds act by inhibiting tumour metabolism and proliferation and by inducing apoptosis in parallel with an activation of AMPK and an inhibition of constitutive mTOR. In tPTEN-/- cells, the drugs potentiated the anti-leukaemic effects of dexamethasone, and metformin and phenformin synergised with 2-deoxyglucose (2DG) to impair tumour cell survival. In vivo, metformin and AICAR strongly decreased the growth of luciferase-expressing tPTEN-/- cells xenografted in Nude mice, demonstrating that metabolism targeting could be a potent adjuvant strategy for lymphoma/leukaemia treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Abandoning a label doesn’t make it disappear: The perseverance of labeling effects

PubMed Central

Foroni, Francesco; Rothbart, Myron

2012-01-01

Labels exert strong influence on perception and judgment. The present experiment examines the possibility that such effects may persist even when labels are abandoned. Participants judged the similarity of pairs of silhouette drawings of female body types, ordered on a continuum from very thin to very heavy, under conditions where category labels were, and were not, superimposed on the ordered stimuli. Consistent with earlier research, labels had strong effects on perceived similarity, with silhouettes sharing the same label judged as more similar than those having different labels. Moreover, when the labels were removed and no longer present, the effect of the labels, although diminished, persisted. It did not make any difference whether the labels were simply abandoned or, in addition, had their validity challenged. The results are important for our understanding of categorization and labeling processes. The potential theoretical and practical implications of these results for social processes are discussed. PMID:23105148

Viewing movie smoking undermines antismoking parenting practices.

PubMed

Sargent, James D; Hanewinkel, Reiner

2008-01-01

To test the hypothesis that viewing depictions of smoking in movies makes adolescents less responsive to parenting factors that prevent smoking. Cross-sectional survey of 4807 students (grades 5-8) through which we ascertained exposure to smoking in movies, parent smoking, and adolescents' perception of parental responsiveness (support), and parental demandingness (behavioral control). Adolescents attending randomly selected middle schools in the Northeastern U.S. ever tried smoking a cigarette. Exposure to movie smoking was ascertained by counting occurrences of tobacco use in 601 recent popular motion pictures; surveying students to identify films they had seen from a random subset of 50 films; and summing tobacco use occurrences for the films each adolescent reported seeing. We also measured adolescents' perceptions of parent smoking, parental responsiveness and demandingness. The overall prevalence of adolescent smoking was 17.4 percent. The prevalence of smoking increased with exposure to movie smoking (low vs. high exposure 8.8 vs. 25.8%, p < 0.0001). Parenting factors associated with lower rates of adolescent smoking were parent non smoking status (11.0% vs. 27.7% for parents who smoke, p < 0.0001), higher levels of demandingness (13.7% vs. 20.7% for low demandingness, p < 0.0001) and higher levels of parental responsiveness (12.4% vs. 23.1% for low parental responsiveness, p < 0.0001). Parenting factors were not strongly associated with exposure to movie smoking. For adolescents with low exposure to movie smoking the adjusted odds (95% confidence interval) of smoking were 0.31 (0.23, 0.42) if parents did not smoke, 0.57 (0.42, 0.78) if parents exerted high demandingness, and 0.52 (0.38, 0.71) if parents were highly responsive. Parents had significantly less influence for adolescents with high exposure to movie smoking, for whom the adjusted odds of smoking were only 0.50 if parents did not smoke (p = 0.014 for the interaction effect), 0.97 if parents exerted high demandingness (p = 0.007 for the interaction effect) and 0.73 if parents were highly responsive (p = 0.045 for the interaction effect). Viewing smoking in movies not only has a direct association with adolescent smoking, it may also undermine parental attempts to prevent this behavior.

Strong Nonvolatile Magnon-Driven Magnetoelectric Coupling in Single-Crystal Co /[PbMg1/3Nb2/3O3] 0.71[PbTiO3]0.29 Heterostructures

NASA Astrophysics Data System (ADS)

Zhou, Cai; Shen, Lvkang; Liu, Ming; Gao, Cunxu; Jia, Chenglong; Jiang, Changjun

2018-01-01

The ability to manipulate the magnetism on interfacing ferromagnetic and ferroelectric materials via electric fields to achieve an emergent multiferroic response has enormous potential for nanoscale devices with novel functionalities. Herein, a strong electric-field control of the magnetism modulation is reported for a single-crystal Co (14 nm )/(001 )Pb (Mg1/3Nb2/3) 0.7Ti0.3O3 (PMN-PT) heterostructure by fabricating an epitaxial Co layer on a PMN-PT substrate. Electric-field-tuned ferromagnetic resonance exhibits a large resonance field shift, with a 120-Oe difference between that under positive and negative remanent polarizations, which demonstrates nonvolatile electric-field control of the magnetism. Further, considering the complexity of the twofold symmetry magnetic anisotropy, the linear change of the fourfold symmetry magnetic anisotropy, relating to the single-crystal cubic magnetocrystal anisotropy of the Co thin film, is resolved and quantified to exert a magnon-driven, strong direct magnetoelectric effect on the Co /PMN -PT interface. These results are promising for future multiferroic devices.

Novel Interventions for Heat/Exercise Induced Sudden Death and Fatigue

DTIC Science & Technology

2013-10-01

mutations associated with enhanced susceptibility to Exertional Heat Stroke (EHS), Exertional Rhabdomyolysis (ER), and Malignant Hyperthermia (MH) by...reduces the probability of a hypermetabolic response in YS mice. 15. SUBJECT TERMS: Exertional Heat Stroke, Exertional Rhabdomyolysis ...and exertional rhabdomyolysis (ER) have been reported in subjects with diagnosis of Malignant Hyperthermia (MH). MH is a life- threatening

Comparison of amine-selective properties of weak and strong cation-exchangers.

PubMed

Stenholm, Ake; Lindgren, Helena; Shaffie, Juliana

2006-09-22

The capacity of several weak and strong cation-exchangers to adsorb 2-diethylaminoethanol (DEAE) and (2,3-hydroxypropyl) trimethylammonium chloride (HPMAC) from sodium-containing process water streams, and the ease of subsequently eluting the amines and regenerating the exchangers, were investigated. (2,3-hydroxypropyl) trimethylammonium chloride was enriched 40-fold compared with the initial amine/sodium-ratio in the bulk fluid by Amberlite IRC-50. The highest selectivity for 2-diethylaminoethanol (26-fold) was provided by Imac HP336. Neither of the selected strong cation-exchangers showed any selectivity towards 2-diethylaminoethanol, but they enriched (2,3-hydroxypropyl) trimethylammonium chloride approximately three to four fold. These findings suggest that weak cation-exchangers (WCX) could be readily used for the selective removal of these or similar amines from sodium-containing process waters.

Strong Purifying Selection at Synonymous Sites in D. melanogaster

PubMed Central

Lawrie, David S.; Messer, Philipp W.; Hershberg, Ruth; Petrov, Dmitri A.

2013-01-01

Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective constraint while few, if any, appear to be under weak constraint. Linking polymorphism with divergence data, we further find that the fraction of synonymous sites exposed to strong purifying selection is higher for those positions that show slower evolution on the Drosophila phylogeny. The function underlying the inferred strong constraint appears to be separate from splicing enhancers, nucleosome positioning, and the translational optimization generating canonical codon bias. The fraction of synonymous sites under strong constraint within a gene correlates well with gene expression, particularly in the mid-late embryo, pupae, and adult developmental stages. Genes enriched in strongly constrained synonymous sites tend to be particularly functionally important and are often involved in key developmental pathways. Given that the observed widespread constraint acting on synonymous sites is likely not limited to Drosophila, the role of synonymous sites in genetic disease and adaptation should be reevaluated. PMID:23737754

Dipeptidyl peptidase IV (DPPIV) enzyme activity on immature T-cell line R1.1 is down-regulated by dynorphin-A(1-17) as a non-substrate inhibitor.

PubMed

Gabrilovac, Jelka; Abramić, Marija; Uzarević, Branka; Andreis, Ana; Poljak, Ljiljana

2003-05-30

In this study we examined surface expression of CD26 and the corresponding enzyme activity of dipeptidyl peptidase IV (DPPIV) on the cells of immature murine T-cell line, R1.1. The data obtained have shown that R1.1 cells express high density of surface CD26 as compared to normal thymus cells. This was associated with strong enzyme activity, which, based on substrates and inhibitor specificity, corresponded to DPPIV. The DPPIV enzyme activity of R1.1 cells was 10 times stronger than that found on normal murine thymus cells (V(max) = 39 micromol/min/10(6) cells, vs 3.7 micromol/min/10(6) cells, respectively). Upon activation with anti-CD3, up-regulation of both membrane CD26, as well as of DPPIV enzyme activity on R1.1 cells were observed. The finding of strong DPPIV on R1.1 cells makes them suitable model for testing putative substrates/inhibitors of the enzyme in its natural microenvironment. Since in addition to strong DPPIV, R1.1 cells also express kappa opioid receptors (KOR) [European Journal of Pharmacology 227 (1992) 257], we tested the effect of dynorphin-A(1-17), an endogenous opioid peptide with KOR selectivity, on DPPIV of R1.1 cells. Dynorphin-A(1-17) down-regulated DPPIV in a dose-dependent manner, with the potency similar to that of substance P, a known natural DPPIV substrate [Journal of Pharmacology and Experimental Therapeutics 260 (1992) 1257]. DPPIV down-regulation was resistant to bestatin and thiorphan, the inhibitors of two cell surface peptidases (APN and NEP, respectively) with potential of dynorphin-A(1-17) degradation, suggesting that the mechanism underlying the observed effect does not involve degradative products of dynorphin-A(1-17). DPPIV down-regulation was also resistent to KOR antagonist, NBI, suggesting that the mechanism underlying the observed phenomenon involves neither cointernalization of KOR and DPPIV. Collectively, cells of immature T cell line, R1.1 exert strong DPPIV enzyme activity, which could be down-regulated in the presence of dynorphin-A(1-17) by mechanism that presumably includes non-substrate inhibition. By down-regulating DPPIV, dynorphin-A(1-17) may indirectly affect activity and/or specificity of natural substrates of DPPIV, such as substance P, RANTES, and endomorphins.

Oligodendrocyte death, neuroinflammation, and the effects of minocycline in a rodent model of nonarteritic anterior ischemic optic neuropathy (rNAION).

PubMed

Mehrabian, Zara; Guo, Yan; Weinreich, Daniel; Bernstein, Steven L

2017-01-01

Optic nerve (ON) damage following nonarteritic anterior ischemic optic neuropathy (NAION) and its models is associated with neurodegenerative inflammation. Minocycline is a tetracycline derivative antibiotic believed to exert a neuroprotective effect by selective alteration and activation of the neuroinflammatory response. We evaluated minocycline's post-induction ability to modify early and late post-ischemic inflammatory responses and its retinal ganglion cell (RGC)-neuroprotective ability. We used the rodent NAION (rNAION) model in male Sprague-Dawley rats. Animals received either vehicle or minocycline (33 mg/kg) daily intraperitoneally for 28 days. Early (3 days) ON-cytokine responses were evaluated, and oligodendrocyte death was temporally evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. Cellular inflammation was evaluated with immunohistochemistry, and RGC preservation was compared with stereology of Brn3a-positive cells in flat mounted retinas. Post-rNAION, oligodendrocytes exhibit a delayed pattern of apoptosis extending over a month, with extrinsic monocyte infiltration occurring only in the primary rNAION lesion and progressive distal microglial activation. Post-induction minocycline failed to improve retinal ganglion cell survival compared with the vehicle treated (893.14 vs. 920.72; p>0.9). Cytokine analysis of the rNAION lesion 3 days post-induction revealed that minocycline exert general inflammatory suppression without selective upregulation of cytokines associated with the proposed alternative or neuroprotective M2 inflammatory pathway. The pattern of cytokine release, extended temporal window of oligodendrocyte death, and progressive microglial activation suggests that selective neuroimmunomodulation, rather than general inflammatory suppression, may be required for effective repair strategies in ischemic optic neuropathies.

Detection and functional analysis of tumor infiltrating T-lymphocytes (TIL) in liver metastases from colorectal cancer.

PubMed

Wagner, Philipp; Koch, Moritz; Nummer, Daniel; Palm, Sylvia; Galindo, Luis; Autenrieth, Daniel; Rahbari, Nuh; Schmitz-Winnenthal, Friedrich H; Schirrmacher, Volker; Büchler, Markus W; Beckhove, Philipp; Weitz, Jürgen

2008-08-01

Tumor-infiltrating T lymphocytes (TIL) play an important role in primary colorectal cancer, but their activity in liver metastases has not yet been investigated. The aim of this study was to examine whether tumor-selective infiltration, activation, and cytotoxic activity of TIL can be demonstrated in situ in colorectal liver metastases. TIL were obtained from liver metastases and corresponding normal liver tissue of 16 patients with colorectal liver metastases. Characterization of TIL in situ was performed by multicolor flowcytometric analysis. Presence of tumor antigen-reactive T cells was evaluated by interferon gamma Elispot analysis. TIL in colorectal liver metastases responding against tumor antigens were present in most patients. Although the proportions of CD3(+) T cells were comparable in liver metastasis and normal liver tissue, metastases contained significantly enhanced proportions of CD4(+) cells (49% vs. 22%, P < .001). Among all CD4(+) T helper cells, the proportion of activated (CD4(+)CD25(+)) effector cells was significantly increased in liver metastases (15.0% vs. 7.8%, P = .003). Metastases showed significantly higher proportions of activated (CD69(+) [70.1% vs. 49.8%, P = .02] and CD25(+) [4.1% vs. .6%, P = .06]) and cytotoxically active (CD107a(+)) CD8(+) TIL (3.2% vs. 1.3%, P = .03). Importantly, the presence of activated T helper cells correlated with the frequencies of cytotoxic T lymphocytes that exerted cytotoxic activity in situ (P = .02). CD4(+) and CD8(+) TIL are selectively activated in liver metastases, and cytotoxic T lymphocytes exert tumor-selective cytotoxic activity in situ in the presence of activated T helper cells, suggesting the requirement of in-situ-activated T helper cells for efficient cytotoxic T lymphocytes effector function.

Evidence That Ly6C(hi) Monocytes are Protective in Acute Ischemic Stroke by Promoting M2 Macrophage Polarization.

PubMed

Chu, Hannah X; Broughton, Brad R S; Kim, Hyun Ah; Lee, Seyoung; Drummond, Grant R; Sobey, Christopher G

2015-07-01

Ly6C(hi) monocytes are generally thought to exert a proinflammatory role in acute tissue injury, although their impact after injuries to the central nervous system is poorly defined. CC chemokine receptor 2 is expressed on Ly6C(hi) monocytes and plays an essential role in their extravasation and transmigration into the brain after cerebral ischemia. We used a selective CC chemokine receptor 2 antagonist, INCB3344, to assess the effect of Ly6C(hi) monocytes recruited into the brain early after ischemic stroke. Male C57Bl/6J mice underwent occlusion of the middle cerebral artery for 1 hour followed by 23 hours of reperfusion. Mice were administered either vehicle (dimethyl sulfoxide/carboxymethylcellulose) or INCB3344 (10, 30 or 100 mg/kg IP) 1 hour before ischemia and at 2 and 6 hours after ischemia. At 24 hours, we assessed functional outcomes, infarct volume, and quantified the immune cells in blood and brain by flow cytometry or immunofluorescence. Gene expression of selected inflammatory markers was assessed by quantitative polymerase chain reaction. Ly6C(hi) monocytes were increased 3-fold in the blood and 10-fold in the brain after stroke, and these increases were selectively prevented by INCB3344 in a dose-dependent manner. Mice treated with INCB3344 exhibited markedly worse functional outcomes and larger infarct volumes, in association with reduced M2 polarization and increased peroxynitrite production in macrophages, compared with vehicle-treated mice. Our data suggest that Ly6C(hi) monocytes exert an acute protective effect after ischemic stroke to limit brain injury and functional deficit that involves promotion of M2 macrophage polarization. © 2015 American Heart Association, Inc.

Controlling for Prior Attainment Reduces the Positive Influence that Single-Gender Classroom Initiatives Exert on High School Students' Scholastic Achievements.

PubMed

Pennington, Charlotte R; Kaye, Linda K; Qureshi, Adam W; Heim, Derek

2018-01-01

Research points to the positive impact that gender-segregated schooling and classroom initiatives exert on academic attainment. An evaluation of these studies which reveal positive effects highlights, however, that students are typically selectively assigned to single- or mixed-gender instructional settings, presenting a methodological confound. The current study controls for students' prior attainment to appraise the efficacy of a single-gender classroom initiative implemented in a co-educational high school in the United Kingdom. Secondary data analysis (using archived data) was performed on 266 middle-ability, 11-12 year-old students' standardized test scores in Languages (English, foreign language), STEM-related (Mathematics, Science, Information and Communication Technology), and Non-STEM subjects (art, music, drama). Ninety-eight students (54, 55% female) were taught in single-gender and 168 (69, 41% female) in mixed-gender classrooms. Students undertook identical tests irrespective of classroom type, which were graded in accordance with U.K national curriculum guidelines. Controlling for students' prior attainment, findings indicate that students do not appear to benefit from being taught in single-gender relative to mixed-gender classrooms in Language and STEM-related subjects. Young women benefitted from being taught in mixed-gender relative to single-gender classes for Non-STEM subjects. However, when prior ability is not controlled for, the intervention appears to be effective for all school subjects, highlighting the confounding influence of selective admissions. These findings suggest that gender-segregated classroom initiatives may not bolster students' grades. It is argued that studies that do not control for selection effects may tell us little about the effectiveness of such interventions on scholastic achievement.

Antidepressant activity of the adenosine A2A receptor antagonist, istradefylline (KW-6002) on learned helplessness in rats.

PubMed

Yamada, Koji; Kobayashi, Minoru; Shiozaki, Shizuo; Ohta, Teruko; Mori, Akihisa; Jenner, Peter; Kanda, Tomoyuki

2014-07-01

Istradefylline, an adenosine A2A receptor antagonist, improves motor function in animal models of Parkinson's disease (PD) and in patients with PD. In addition, some A2A antagonists exert antidepressant-like activity in rodent models of depression, such as the forced swim and the tail suspension tests. We have investigated the effect of istradefylline on depression-like behaviors using the rat learned helplessness (LH) model. Acute, as well as chronic, oral administration of istradefylline significantly improved the inescapable shock (IES)-induced escape deficit with a degree of efficacy comparable to chronic treatment with the tricyclic antidepressant desipramine and the selective serotonin (5-HT) reuptake inhibitor, fluoxetine. Both the A1/A2A receptor nonspecific antagonist theophylline and the moderately selective antagonist CGS15943, but not the A1 selective antagonist DPCPX, ameliorated the IES-induced escape deficit. The enhancement of escape response by istradefylline was reversed by a local injection of the A2A specific agonist CGS21680 either into the nucleus accumbens, the caudate-putamen, or the paraventricular nucleus of the hypothalamus, but not by the A1 specific agonist R-PIA into the nucleus accumbens. Moreover, neither the 5-HT2A/2C receptor antagonist methysergide or the adrenergic α 2 antagonist yohimbine, nor the β-adrenergic antagonist propranolol, affected the improvement of escape response induced by istradefylline. Istradefylline exerts antidepressant-like effects via modulation of A2A receptor activity which is independent of monoaminergic transmission in the brain. Istradefylline may represent a novel treatment option for depression in PD as well as for the motor symptoms.

Oligodendrocyte death, neuroinflammation, and the effects of minocycline in a rodent model of nonarteritic anterior ischemic optic neuropathy (rNAION)

PubMed Central

Mehrabian, Zara; Guo, Yan; Weinreich, Daniel

2017-01-01

Purpose Optic nerve (ON) damage following nonarteritic anterior ischemic optic neuropathy (NAION) and its models is associated with neurodegenerative inflammation. Minocycline is a tetracycline derivative antibiotic believed to exert a neuroprotective effect by selective alteration and activation of the neuroinflammatory response. We evaluated minocycline’s post-induction ability to modify early and late post-ischemic inflammatory responses and its retinal ganglion cell (RGC)–neuroprotective ability. Methods We used the rodent NAION (rNAION) model in male Sprague-Dawley rats. Animals received either vehicle or minocycline (33 mg/kg) daily intraperitoneally for 28 days. Early (3 days) ON-cytokine responses were evaluated, and oligodendrocyte death was temporally evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. Cellular inflammation was evaluated with immunohistochemistry, and RGC preservation was compared with stereology of Brn3a-positive cells in flat mounted retinas. Results Post-rNAION, oligodendrocytes exhibit a delayed pattern of apoptosis extending over a month, with extrinsic monocyte infiltration occurring only in the primary rNAION lesion and progressive distal microglial activation. Post-induction minocycline failed to improve retinal ganglion cell survival compared with the vehicle treated (893.14 vs. 920.72; p>0.9). Cytokine analysis of the rNAION lesion 3 days post-induction revealed that minocycline exert general inflammatory suppression without selective upregulation of cytokines associated with the proposed alternative or neuroprotective M2 inflammatory pathway. Conclusions The pattern of cytokine release, extended temporal window of oligodendrocyte death, and progressive microglial activation suggests that selective neuroimmunomodulation, rather than general inflammatory suppression, may be required for effective repair strategies in ischemic optic neuropathies. PMID:29386871

Highly Selective Coupling of Alkenes and Aldehydes Catalyzed by NHC–Ni–P(OPh)3: Synergy Between a Strong σ-Donor and a Strong π-Acceptor**

PubMed Central

Ho, Chun-Yu; Jamison, Timothy F.

2011-01-01

Both a strong electron donor (IPr) and a strong electron acceptor (P(OPh)3) are necessary for a highly selective, nickel-catalyzed coupling reaction between alkenes, aldehydes, and silyltriflates. Without the phosphite, catalysis is not observed and several side reactions are observed. The phosphite appears to suppress the formation of these byproducts and rescue the catalytic cycle by accelerating reductive elimination from an (IPr–Ni–H)(OTf) complex. PMID:17154217

Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

PubMed

Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

2017-05-15

Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

Newly Isolated Paenibacillus tyrfis sp. nov., from Malaysian Tropical Peat Swamp Soil with Broad Spectrum Antimicrobial Activity

PubMed Central

Aw, Yoong-Kit; Ong, Kuan-Shion; Lee, Learn-Han; Cheow, Yuen-Lin; Yule, Catherine M.; Lee, Sui-Mae

2016-01-01

Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences for human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystems such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1T that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1T belonged to the genus Paenibacillus with the highest similarity to Paenibacillus elgii SD17T (99.5%). Whole genome comparison between strain MSt1T with its closely related species using average nucleotide identity (ANI) revealed that similarity between strain MSt1T with P. elgii B69 (93.45%) and Paenibacillus ehimensis A2 (90.42%) was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1T with P. elgii B69 (55.4%) and P. ehimensis A2 (43.7%) was below the recommended threshold of 70%. Strain MSt1T contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1T were anteiso-C15:0 (48.2%) and C16:0 (29.0%) whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids, and one unknown phospholipid. Total DNA G+C content of strain MSt1T was 51.5 mol%. The extract from strain MSt1T exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 μg/mL), MRSA ATCC 700699 (MIC = 25 μg/mL) and Candida albicans IMR (MIC = 12.5 μg/mL). Partially purified active fraction exerted a strong effect against E. coli ATCC 25922 resulting in cell rupture when viewed with SEM. Based on distinctive taxonomic differences between strain MSt1T when compared to its closely related type species, we propose that strain MSt1T represents a novel species within the genus of Paenibacillus, for which the name Paenibacillus tyrfis sp. nov. (= DSM 100708T = MCCC 1K01247T) is proposed. PMID:26973605

The role of apoptosis repressor with a CARD domain (ARC) in the therapeutic resistance of renal cell carcinoma (RCC): the crucial role of ARC in the inhibition of extrinsic and intrinsic apoptotic signalling.

PubMed

Toth, Csaba; Funke, Sarah; Nitsche, Vanessa; Liverts, Anna; Zlachevska, Viktoriya; Gasis, Marcia; Wiek, Constanze; Hanenberg, Helmut; Mahotka, Csaba; Schirmacher, Peter; Heikaus, Sebastian

2017-05-02

Renal cell carcinomas (RCCs) display broad resistance against conventional radio- and chemotherapies, which is due at least in part to impairments in both extrinsic and intrinsic apoptotic pathways. One important anti-apoptotic factor that is strongly overexpressed in RCCs and known to inhibit both apoptotic pathways is ARC (apoptosis repressor with a CARD domain). Expression and subcellular distribution of ARC in RCC tissue samples and RCC cell lines were determined by immunohistochemistry and fluorescent immunohistochemistry, respectively. Extrinsic and intrinsic apoptosis signalling were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT-263 or topotecan. ARC knock-down was performed in clearCa-12 cells using lentiviral transduction of pGIPZ. shRNAmir constructs. Extrinsic respectively intrinsic apoptosis were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT263 or topotecan. Potential synergistic effects were tested by pre-treatment with topotecan and subsequent treatment with ABT263. Activation of different caspases and mitochondrial depolarisation (JC-1 staining) were analysed by flow cytometry. Protein expression of Bcl-2 family members and ARC in RCC cell lines was measured by Western blotting. Statistical analysis was performed by Student's t-test. Regarding the extrinsic pathway, ARC knockdown strongly enhanced TRAIL-induced apoptosis by increasing the activation level of caspase-8. Regarding the intrinsic pathway, ARC, which was only weakly expressed in the nuclei of RCCs in vivo, exerted its anti-apoptotic effect by impairing mitochondrial activation rather than inhibiting p53. Topotecan- and ABT-263-induced apoptosis was strongly enhanced following ARC knockdown in RCC cell lines. In addition, topotecan pre-treatment enhanced ABT-263-induced apoptosis and this effect was amplified in ARC-knockdown cells. Taken together, our results are the first to demonstrate the importance of ARC protein in the inhibition of both the extrinsic and intrinsic pathways of apoptosis in RCCs. In this context, ARC cooperates with anti-apoptotic Bcl-2 family members to exert its strong anti-apoptotic effects and is therefore an important factor not only in the therapeutic resistance but also in future therapy strategies (i.e., Bcl-2 inhibitors) in RCC. In sum, targeting of ARC may enhance the therapeutic response in combination therapy protocols.

Selective Control of Attention Supports the Positivity Effect in Aging

PubMed Central

Sasse, Laura K.; Gamer, Matthias; Büchel, Christian; Brassen, Stefanie

2014-01-01

There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging. PMID:25093459

Selective control of attention supports the positivity effect in aging.

PubMed

Sasse, Laura K; Gamer, Matthias; Büchel, Christian; Brassen, Stefanie

2014-01-01

There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging.

Multiscale modeling of nerve agent hydrolysis mechanisms: a tale of two Nobel Prizes

NASA Astrophysics Data System (ADS)

Field, Martin J.; Wymore, Troy W.

2014-10-01

The 2013 Nobel Prize in Chemistry was awarded for the development of multiscale models for complex chemical systems, whereas the 2013 Peace Prize was given to the Organisation for the Prohibition of Chemical Weapons for their efforts to eliminate chemical warfare agents. This review relates the two by introducing the field of multiscale modeling and highlighting its application to the study of the biological mechanisms by which selected chemical weapon agents exert their effects at an atomic level.

Physical Training Programs in Light Infantry Units: Are They Preparing Soldiers for the Rigors of Combat?

DTIC Science & Technology

2001-01-01

selection is made which ensure further injury is not incurred during evacuation. As a result, the basic task identified is carry. Demanding Physical Tasks...greatest amount of force a muscle or muscle group can exert in a single effort.3 An example, in very simple terms, would be an Olympic weightlifter ...Olympic weightlifters lift as much as possible in one lift. This requires a great amount of strength. A need for strength in light infantry soldiers is

The Effects of Local Exertion and Anticipation on the Performance of a Discrete Skill.

DTIC Science & Technology

1986-01-01

295-298. Davies, B.T. & Ward, H. (1978). The effect of physical work on a subsequent fine manipulative task. Ergonomics , 21, 939-944. Dechovitz, A.B...Lt Jaeger’s next assignment was at the Occupational Measurement Cente r, Lackland AFB, Texas, where for three years he wrote and edited achievement...psychology, and human factors engineering for two years, then was selected for advanced graduate work in ergonomics under the sponsorship of the Air

Isolation and Assessment of the in Vitro Anti-Tumor Activity of Smenothiazole A and B, Chlorinated Thiazole-Containing Peptide/Polyketides from the Caribbean Sponge, Smenospongia aurea

PubMed Central

Esposito, Germana; Teta, Roberta; Miceli, Roberta; Ceccarelli, Luca S.; Della Sala, Gerardo; Camerlingo, Rosa; Irollo, Elena; Mangoni, Alfonso; Pirozzi, Giuseppe; Costantino, Valeria

2015-01-01

The study of the secondary metabolites contained in the organic extract of Caribbean sponge Smenospongia aurea led to the isolation of smenothiazole A (3) and B (4), hybrid peptide/polyketide compounds. Assays performed using four solid tumor cell lines showed that smenothiazoles exert a potent cytotoxic activity at nanomolar levels, with selectivity over ovarian cancer cells and a pro-apoptotic mechanism. PMID:25603342

Issues in impedance selection and input devices for multijoint powered orthotics.

PubMed

Lemay, M A; Hogan, N; van Dorsten, J W

1998-03-01

We investigated the applicability of impedance controllers to robotic orthoses for arm movements. We had tetraplegics turn a crank using their paralyzed arm propelled by a planar robot manipulandum. The robot was under impedance control, and chin motion served as command source. Stiffness varied between 50, 100, or 200 N/m and damping varied between 5 or 15 N/m/s. Results indicated that a low stiffness and high viscosity provided better directional control of the tangential force exerted on the crank.

Stabilizing selection on sperm number revealed by artificial selection and experimental evolution.

PubMed

Cattelan, Silvia; Di Nisio, Andrea; Pilastro, Andrea

2018-03-01

Sperm competition is taxonomically widespread in animals and is usually associated with large sperm production, being the number of sperm in the competing pool the prime predictor of fertilization success. Despite the strong postcopulatory selection acting directionally on sperm production, its genetic variance is often very high. This can be explained by trade-offs between sperm production and traits associated with mate acquisition or survival, that may contribute to generate an overall stabilizing selection. To investigate this hypothesis, we first artificially selected male guppies (Poecilia reticulata) for high and low sperm production for three generations, while simultaneously removing sexual selection. Then, we interrupted artificial selection and restored sexual selection. Sperm production responded to divergent selection in one generation, and when we restored sexual selection, both high and low lines converged back to the mean sperm production of the original population within two generations, indicating that sperm number is subject to strong stabilizing total sexual selection (i.e., selection acting simultaneously on all traits associated with reproductive success). We discuss the possible mechanisms responsible for the maintenance of high genetic variability in sperm production despite strong selection acting on it. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

Altering spatial priority maps via reward-based learning.

PubMed

Chelazzi, Leonardo; Eštočinová, Jana; Calletti, Riccardo; Lo Gerfo, Emanuele; Sani, Ilaria; Della Libera, Chiara; Santandrea, Elisa

2014-06-18

Spatial priority maps are real-time representations of the behavioral salience of locations in the visual field, resulting from the combined influence of stimulus driven activity and top-down signals related to the current goals of the individual. They arbitrate which of a number of (potential) targets in the visual scene will win the competition for attentional resources. As a result, deployment of visual attention to a specific spatial location is determined by the current peak of activation (corresponding to the highest behavioral salience) across the map. Here we report a behavioral study performed on healthy human volunteers, where we demonstrate that spatial priority maps can be shaped via reward-based learning, reflecting long-lasting alterations (biases) in the behavioral salience of specific spatial locations. These biases exert an especially strong influence on performance under conditions where multiple potential targets compete for selection, conferring competitive advantage to targets presented in spatial locations associated with greater reward during learning relative to targets presented in locations associated with lesser reward. Such acquired biases of spatial attention are persistent, are nonstrategic in nature, and generalize across stimuli and task contexts. These results suggest that reward-based attentional learning can induce plastic changes in spatial priority maps, endowing these representations with the "intelligent" capacity to learn from experience. Copyright © 2014 the authors 0270-6474/14/348594-11$15.00/0.