234 research outputs found

    High-order Harmonic Generation and Dynamic Localization in a driven two-level system, a non-perturbative solution using the Floquet-Green formalism

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    We apply the Floquet-Green operator formalism to the case of a harmonically-driven two-level system. We derive exact expressions for the quasi-energies and the components of the Floquet eigenstates with the use of continued fractions. We study the avoided crossings structure of the quasi-energies as a function of the strength of the driving field and give an interpretation in terms of resonant multi-photon processes. From the Floquet eigenstates we obtain the time-evolution operator. Using this operator we study Dynamic Localization and High-order Harmonic Generation in the non-perturbative regime

    Gender Dimorphism in Skeletal Muscle Leptin Receptors, Serum Leptin and Insulin Sensitivity

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    To determine if there is a gender dimorphism in the expression of leptin receptors (OB-R170, OB-R128 and OB-R98) and the protein suppressor of cytokine signaling 3 (SOCS3) in human skeletal muscle, the protein expression of OB-R, perilipin A, SOCS3 and alpha-tubulin was assessed by Western blot in muscle biopsies obtained from the m. vastus lateralis in thirty-four men (age = 27.1±6.8 yr) and thirty-three women (age = 26.7±6.7 yr). Basal serum insulin concentration and HOMA were similar in both genders. Serum leptin concentration was 3.4 times higher in women compared to men (P<0.05) and this difference remained significant after accounting for the differences in percentage of body fat or soluble leptin receptor. OB-R protein was 41% (OB-R170, P<0.05) and 163% (OB-R128, P<0.05) greater in women than men. There was no relationship between OB-R expression and the serum concentrations of leptin or 17β-estradiol. In men, muscle OB-R128 protein was inversely related to serum free testosterone. In women, OB-R98 and OB-R128 were inversely related to total serum testosterone concentration, and OB-R128 to serum free testosterone concentration. SOCS3 protein expression was similar in men and women and was not related to OB-R. In women, there was an inverse relationship between the logarithm of free testosterone and SCOS3 protein content in skeletal muscle (r = −0.46, P<0.05). In summary, there is a gender dimorphism in skeletal muscle leptin receptors expression, which can be partly explained by the influence of testosterone. SOCS3 expression in skeletal muscle is not up-regulated in women, despite very high serum leptin concentrations compared to men. The circulating form of the leptin receptor can not be used as a surrogate measure of the amount of leptin receptors expressed in skeletal muscles

    Changes in grassland management and linear infrastructures associated to the decline of an endangered bird population

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    European grassland birds are experiencing major population declines, mainly due to changes in farmland management. We analyzed the role of habitat availability, grazing management and linear infrastructures (roads and power lines) in explaining spatial and temporal variation in the population density of little bustards (Tetrax tetrax) in Portugal, during a decade in which the species population size halved. We used data from 51 areas (totaling ca. 1,50,000 ha) that were sampled in two different periods (2003–2006 and 2016). In 2003–2006, when the species occurred at high densities, habitat availability was the only factor affecting spatial variation in bustard density. In the 2016 survey, variation in density was explained by habitat availability and livestock management, with reduced bird numbers in areas with higher proportions of cattle. Population declines across the study period were steeper in areas that initially held higher densities of bustards and in areas with a higher proportion of cattle in the total stocking rate. Areas with higher densities of power lines also registered greater density declines, probably due to avoidance behavior and to increased mortality. Overall, our results show little bustards are currently lacking high quality grassland habitat, whose persistence depends on extensive grazing regimes and low linear infrastructure densitiesinfo:eu-repo/semantics/publishedVersio

    Antimalarial Activity and Mechanisms of Action of Two Novel 4-Aminoquinolines against Chloroquine-Resistant Parasites

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    Chloroquine (CQ) is a cost effective antimalarial drug with a relatively good safety profile (or therapeutic index). However, CQ is no longer used alone to treat patients with Plasmodium falciparum due to the emergence and spread of CQ-resistant strains, also reported for P. vivax. Despite CQ resistance, novel drug candidates based on the structure of CQ continue to be considered, as in the present work. One CQ analog was synthesized as monoquinoline (MAQ) and compared with a previously synthesized bisquinoline (BAQ), both tested against P. falciparum in vitro and against P. berghei in mice, then evaluated in vitro for their cytotoxicity and ability to inhibit hemozoin formation. Their interactions with residues present in the NADH binding site of P falciparum lactate dehydrogenase were evaluated using docking analysis software. Both compounds were active in the nanomolar range evaluated through the HRPII and hypoxanthine tests. MAQ and BAQ derivatives were not toxic, and both compounds significantly inhibited hemozoin formation, in a dose-dependent manner. MAQ had a higher selectivity index than BAQ and both compounds were weak PfLDH inhibitors, a result previously reported also for CQ. Taken together, the two CQ analogues represent promising molecules which seem to act in a crucial point for the parasite, inhibiting hemozoin formation

    Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies

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    The pelidnotine scarabs (Scarabaeidae: Rutelinae: Rutelini) are a speciose, paraphyletic assemblage of beetles that includes spectacular metallic species (“jewel scarabs”) as well as species that are ecologically important as herbivores, pollinators, and bioindicators. These beetles suffer from a complicated nomenclatural history, due primarily to 20th century taxonomic and nomenclatural errors. We review the taxonomic history of the pelidnotine scarabs, present a provisional key to genera with overviews of all genera, and synthesize a catalog of all taxa with synonyms, distributional data, type specimen information, and 107 images of exemplar species. As a result of our research, the pelidnotine leaf chafers (a paraphyletic group) include 27 (26 extant and 1 extinct) genera and 420 valid species and subspecies (419 extant and 1 extinct). Our research makes biodiversity research on this group tractable and accessible, thus setting the stage for future studies that address evolutionary and ecological trends. Based on our research, 1 new species is described, 1 new generic synonym and 12 new species synonyms are proposed, 11 new lectotypes and 1 new neotype are designated, many new or revised nomenclatural combinations, and many unavailable names are presented. The following taxonomic changes are made: New generic synonym: The genus Heteropelidnota Ohaus, 1912 is a new junior synonym of Pelidnota MacLeay, 1819. New species synonyms: Plusiotis adelaida pavonacea Casey, 1915 is a syn. n. of Chrysina adelaida (Hope, 1841); Odontognathus gounellei Ohaus, 1908 is a revised synonym of Pelidnota ebenina (Blanchard, 1842); Pelidnota francoisgenieri Moore & Jameson, 2013 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota genieri Soula, 2009 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota lutea (Olivier, 1758) is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Pelidnota) texensis Casey, 1915 is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Strigidia) zikani (Ohaus, 1922) is a revised synonym of Pelidnota tibialis tibialis Burmeister, 1844; Pelidnota ludovici Ohaus, 1905 is a syn. n. of Pelidnota burmeisteri tricolor Nonfried, 1894; Rutela fulvipennis Germar, 1824 is syn. n. of Pelidnota cuprea (Germar, 1824); Pelidnota pulchella blanda Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota pulchella scapularis Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota xanthogramma Perty, 1830 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819). New or revised statuses: Pelidnota fabricelavalettei Soula, 2009, revised status, is considered a species; Pelidnota rioensis Soula, 2009, stat. n., is considered a species; Pelidnota semiaurata semiaurata Burmeister, 1844, stat. rev., is considered a subspecies. New or comb. rev. and revised status: Plusiotis guaymi Curoe, 2001 is formally transferred to the genus Chrysina (C. guaymi (Curoe, 2001), comb. n.); Plusiotis transvolcanica Morón & Nogueira, 2016 is transferred to the genus Chrysina (C. transvolcanica (Morón & Nogueira, 2016), comb. n.). Heteropelidnota kuhnti Ohaus, 1912 is transferred to the genus Pelidnota (P. kuhnti (Ohaus, 1912), comb. n.); Odontognathus riedeli Ohaus, 1905 is considered a subspecies of Pelidnota rubripennis Burmeister, 1844 (Pelidnota rubripennis riedeli (Ohaus, 1905), revised status and comb. rev.); Pelidnota (Strigidia) acutipennis (F. Bates, 1904) is transferred to the genus Sorocha (Sorocha acutipennis (F. Bates, 1904), comb. rev.); Pelidnota (Odontognathus) nadiae Martínez, 1978 is transferred to the genus Sorocha (Sorocha nadiae (Martínez, 1978), comb. rev.); Pelidnota (Ganonota) plicipennis Ohaus, 1934 is transferred to the genus Sorocha (Sorocha plicipennis (Ohaus, 1934), comb. rev.); Pelidnota similis Ohaus, 1908 is transferred to the genus Sorocha (Sorocha similis (Ohaus, 1908), comb. rev.); Pelidnota (Ganonota) yungana Ohaus, 1934 is transferred to Sorocha (Sorocha yungana (Ohaus, 1934), comb. rev.); Pelidnota malyi Soula, 2010: 58, revised status; Xenopelidnota anomala porioni Chalumeau, 1985, revised subspecies status. To stabilize the classification of the group, a neotype is designated for the following species: Pelidnota thiliezi Soula, 2009. Lectotypes are designated for the following names (given in their original combinations): Pelidnota brevicollis Casey, 1915, Pelidnota brevis Casey, 1915, Pelidnota debiliceps Casey, 1915, Pelidnota hudsonica Casey, 1915, Pelidnota oblonga Casey, 1915, Pelidnota pallidipes Casey, 1915, Pelidnota ponderella Casey, 1915, Pelidnota strenua Casey, 1915, Pelidnota tarsalis Casey, 1915, Pelidnota texensis Casey, 1915, and Scarabaeus punctatus Linnaeus, 1758. The following published infrasubspecific names are unavailable per ICZN Article 45.6.1: Pelidnota (Odontognathus) cuprea var. coerulea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. rufoviolacea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. nigrocoerulea Ohaus, 1913; Pelidnota pulchella var. fulvopunctata Ohaus, 1913; Pelidnota pulchella var. sellata Ohaus, 1913; Pelidnota pulchella var. reducta Ohaus, 1913; Pelidnota unicolor var. infuscata Ohaus, 1913. The following published species name is unavailable per ICZN Article 11.5: Neopatatra synonyma Moore & Jameson, 2013. The following published species name is unavailable per application of ICZN Article 16.1: Parhoplognathus rubripennis Soula, 2008. Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) 3 The following published species name is unavailable per application of ICZN Article 16.4.1: Strigidia testaceovirens argentinica Soula, 2006, Pelidnota (Strigidia) testaceovirens argentinica (Soula, 2006), and Pelidnota testaceovirens argentinica (Soula, 2006). The following published species names are unavailable per application of ICZN Article 16.4.2: Homonyx digennaroi Soula, 2010; Homonyx lecourti Soula, 2010; Homonyx mulliei Soula, 2010; Homonyx simoensi Soula, 2010; Homonyx wagneri Soula, 2010; Homonyx zovii Demez & Soula, 2011; Pelidnota arnaudi Soula, 2009; Pelidnota brusteli Soula, 2010; Pelidnota chalcothorax septentrionalis Soula, 2009; Pelidnota degallieri Soula, 2010; Pelidnota lavalettei Soula, 2008; Pelidnota lavalettei Soula, 2009; Pelidnota dieteri Soula, 2011; Strigidia gracilis decaensi Soula, 2008, Pelidnota (Strigidia) gracilis decaensi (Soula, 2008), and Pelidnota gracilis decaensi (Soula, 2008); Pelidnota halleri Demez & Soula, 2011; Pelidnota injantepalominoi Demez & Soula, 2011; Pelidnota kucerai Soula, 2009; Pelidnota malyi Soula, 2010: 36-37; Pelidnota mezai Soula, 2009; Pelidnota polita darienensis Soula, 2009; Pelidnota polita orozcoi Soula, 2009; Pelidnota polita pittieri Soula, 2009; Pelidnota punctulata decolombia Soula, 2009; Pelidnota punctulata venezolana Soula, 2009; Pelidnota raingeardi Soula, 2009; Pelidnota schneideri Soula, 2010; Pelidnota simoensi Soula, 2009; Pelidnota unicolor subandina Soula, 2009; Sorocha carloti Demez & Soula, 2011; Sorocha castroi Soula, 2008; Sorocha fravali Soula, 2011; Sorocha jeanmaurettei Demez & Soula, 2011; Sorocha yelamosi Soula, 2011; Xenopelidnota bolivari Soula, 2009; Xenopelidnota pittieri pittieri Soula, 2009. Due to unavailability of the name Pseudogeniates cordobaensis Soula 2009, we describe the species as intentionally new (Pseudogeniates cordobaensis Moore, Jameson, Garner, Audibert, Smith, and Seidel, sp. n.)

    The DECam Local Volume Exploration Survey Data Release 2

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    We present the second public data release (DR2) from the DECam Local Volume Exploration survey (DELVE). DELVE DR2 combines new DECam observations with archival DECam data from the Dark Energy Survey, the DECam Legacy Survey, and other DECam community programs. DELVE DR2 consists of similar to 160,000 exposures that cover >21,000 deg(2) of the high-Galactic-latitude ( divide b divide > 10 degrees) sky in four broadband optical/near-infrared filters (g, r, i, z). DELVE DR2 provides point-source and automatic aperture photometry for similar to 2.5 billion astronomical sources with a median 5 sigma point-source depth of g = 24.3, r = 23.9, i = 23.5, and z = 22.8 mag. A region of similar to 17,000 deg(2) has been imaged in all four filters, providing four-band photometric measurements for similar to 618 million astronomical sources. DELVE DR2 covers more than 4 times the area of the previous DELVE data release and contains roughly 5 times as many astronomical objects. DELVE DR2 is publicly available via the NOIRLab Astro Data Lab science platform

    Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

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    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z0.03z\sim 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z0.6z\sim 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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