41,358 research outputs found
Hyphocapnodia Z. H. Lu & Maharachch. 2022, gen. nov.
No full textHyphocapnodia Z. H. Lu & Maharachch., gen. nov. MycoBank number: MB 845348 Etymology: The name reflects the hyphomycetous morph phylogenetically related to Capnodium Saprobic on living and decaying branches. Sexual morph: not observed. Asexual morph: on the natural substrate, colonies effuse, hairy, black. Mycelium immersed and superficial, forming dark brown conidiomata. Conidiomata synnematous, erect, subcylindrical, dark brown to black, with conidiogenous cells distributed mostly laterally, mainly towards the upper half of the synnemata. Conidiophores macronematous, simple, dark brown. Conidiogenous cells monoblastic, cylindrical, integrated, determinate, and smooth. Conidia subcylindrical to fusiform, brown, transversely septate, conidial secession schizolytic. Type species: Hyphocapnodia sichuanensis Z. H. Lu, Wanas., Madrid & Maharachch., sp. nov.Published as part of Lu, Zheng-Hua, Wanasinghe, Dhanushka N., Madrid, Hugo & Maharachchikumbura, Sajeewa S. N., 2022, Hyphocapnodia sichuanensis gen. et sp. nov. (Capnodiaceae), a novel hyphomycete from Sichuan Province, China, pp. 84-94 in Phytotaxa 564 (1) on page 90, DOI: 10.11646/phytotaxa.564.1.6, http://zenodo.org/record/707786
The nature and evolution of H alpha emitters at high-z with HiZELS
No full textThe High-z Emission Line Survey (HiZELS) is targeting H alpha emitters at z similar to 0.8 - 2.2, and, by probing large volumes down to faint fluxes with WFCAM on UKIRT, is resulting in the largest samples of high-z H alpha selected star-forming galaxies. With HiZELS, we have accurately measured the evolution of the H alpha luminosity function up to z > 2 in a fully consistent way and determined the H alpha-based star formation history of the Universe since z similar to 2.2 for the first time. We have found important morphology-H alpha relations and have been able to show that it is the evolution of disk galaxies from z similar to 1 to z similar to 0 that is responsible for the decline in the cosmic star formation activity not the decline in merger activity. Furthermore, we have conducted the first detailed clustering analysis of H alpha emitters at z similar to 1 and their evolution up to z > 2, not only finding strong relations with H alpha luminosity and infra-red luminosity, but also suggesting a single, fundamental relation valid over the last 10 Gyrs, relating the dark-matter halo mass and quenching of star-formation across cosmic time. HiZELS is probing a large variety of environments, enabling us to detail the dependence of star formation activity on environment and stellar mass, reconciling previous contradictory results in the literature and providing a much sharper view of our understanding at z similar to 1
Rohdea wangiana H. Z. Feng & Z. Qiang Lu 2021, sp. nov.
No full text<i>Rohdea wangiana</i> H. Z. Feng & Z. Qiang Lu, <i>sp. nov.</i> (Fig. 1) <p> <b>Diagnosis:</b> The new species resembles <i>R. pachynema</i>, but differs based on absence of slender stolons, the leaf blade with serrate margin, one bract per flower, peduncle ebracteate, with protuberance between two filaments and the positions of filaments and stigma in the perianth tube.</p> <p> <b>Type</b>:— CHINA. Sichuan, Xichang, alt. 3250 m, 12 April 2021, <i>H. Z</i> <i>. Feng & Z. Q.</i> <i>Lu 1327</i> (holotype, HITBC!).</p> <p>Chamaephytic herb. Rhizome cylindrical, up to 3.5 cm ca. in diameter, without slender stolons. Roots fibrous, to 3 mm in diameter. Leaves up to 15, sword-shaped, acute at apex, coriaceous, margin sparsely serrulate, 25–40 cm long, 2–3 cm broad. Peduncle 2–5 cm long, ebracteate. Spike oblong, densely many-flowered, 3–5 cm long, 1.5– 2 cm in diameter, without marked terminal tuft of sterile bracts. One bract per flower, lanceolate, usually obtuse at apex, exceeding flower, up to 10–15 mm long. Perianth campanulate, succulence, 5–10 mm across; 5 (6)-lobes; lobes broadly ovate, some lobes with dorsal angular protuberance 3–5 mm long, subacute to obtuse at apex, inflexed above, sometimes 3-lobed, or denticulate, imbricate below, 3–5 mm long, 3–8 mm broad; tube 3–5 mm long. Anthers orbicular-elliptic, ovate or broadly ovate, 1–1.3 mm long; filaments are inserted to the base of the perianth segments, free part incurved, deltoid or broadly dilated toward base, often slightly connate basally with adjacent ones, fleshy, with one small protuberance between two filaments, 2 mm long. Pistil 2.5–3 mm long; stigma trisected, lower than anthers; style columnar, 1–1.5 mm long; ovary slightly depressed globose, 1–1.5 mm long.</p> <p> <b>Etymology</b>:—The specific epithet is in honor of Professor Fa Tsuan Wang (1899-1985, PE), a pioneer in study of Liliflorae in China.</p> <p> <b>Distribution</b>:—This new species is currently known only from Xichang, Liangshan, Sichuan, China.</p> <p> <b>Taxonomic relationships</b>:—Comparison with known species of <i>Rohdea</i> indicates that <i>R. wangiana</i> is similar to <i>R. pachynema</i> by lack of marked terminal tuft of sterile bracts and filaments (free part) deltoid or prominently dilated below. However, <i>R. wangiana</i> differs from <i>R. pachynema</i> by serrate (vs. entire) margin of leaf blade (Fig. 3A, C), ebracteate peduncle (Fig. 3A), one bract per flower (Fig. 2), obvious angular protuberance at some perianth lobes (Fig. 1E, F, H, Fig. 2G, H), and small protuberance between filaments (Fig. 1G). According to Tanaka (2010), <i>R. pachynema</i> has slender subterranean stolons, whereas stolons are absent in <i>R. wangiana</i> under both wild and cultivated conditions. In <i>R. pachynema</i>, filaments are inserted slightly below the base of perianth segments, but inserted to the base of the perianth segments in <i>R. wangiana</i>. According to Tanaka (2010) and Wang & Tang (1949), the stigma and stamens are in the same plane in <i>R. pachynema</i>, but the stigma obviously lower than stamens in <i>R. wangiana</i> (Fig. 1F). Hence, this new species differs from <i>R. pachynema</i> based on multiple lines of evidence from phenological isolation and phenotypic divergence.</p>Published as part of <i>Feng, Hui Zhe, Lu, Zhi Qiang, Han, Qingxiang & Shen, Henglun, 2021, Rohdea wangiana (Asparagaceae), a new species from southwestern Sichuan, China, pp. 247-253 in Phytotaxa 523 (3)</i> on page 248, DOI: 10.11646/phytotaxa.523.3.5, <a href="http://zenodo.org/record/5591444">http://zenodo.org/record/5591444</a>
Influence of psychogenic and neurogenic stressors on endocrine and immune activity: differential effects in fast and slow seizing rat strains
No full textVariations of plasma ACTH and corticosterone, splenic macrophage activity, and mitogen-induced cell proliferation were determined in male rats following 15 min of either neurogenic stress (restraint) or psychogenic stress (exposure to a ferret). The effects of these stressors were assessed in 2 strains of rats bred for either Fast or Slow kindling epileptogenesis triggered in response to amygdala stimulation
Influence of a psychogenic and a neurogenic stressor on several indices of immune functioning in different strains of mice
No full textExamined whether cell proliferation in response to mitogens, natural killer cell (NK) activity, and macrophage functioning of mice may be influenced by either a neurogenic stressor (footshock) or psychogenic stressor (exposing the mouse to a predator, namely a rat)
CONSTRAINING THE STAR FORMATION HISTORIES IN DARK MATTER HALOS. I. CENTRAL GALAXIES
No full textUsing the self-consistent modeling of the conditional stellar mass functions across cosmic time by Yang et al., we make model predictions for the star formation histories (SFHs) of central galaxies in halos of different masses. The model requires the following two key ingredients: (1) mass assembly histories of central and satellite galaxies and (2) local observational constraints of the star formation rates (SFRs) of central galaxies as a function of halo mass. We obtain a universal fitting formula that describes the (median) SFH of central galaxies as a function of halo mass, galaxy stellar mass, and redshift. We use this model to make predictions for various aspects of the SFRs of central galaxies across cosmic time. Our main findings are the following. (1) The specific star formation rate at high z increases rapidly with increasing redshift [proportional to(1 + z)(2.5)] for halos of a given mass and only slowly with halo mass (proportional to M-h(0.12)) at a given z, in almost perfect agreement with the specific mass accretion rate of dark matter halos. (2) The ratio between the SFR in the main branch progenitor and the final stellar mass of a galaxy peaks roughly at a constant value, similar to 10(-9.3) h(2) yr(-1), independent of the halo mass or the final stellar mass of the galaxy. However, the redshift at which the SFR peaks increases rapidly with halo mass. (3) More than half of the stars in the present-day universe were formed in halos with 10(11.1) h(-1)M(circle dot) < M-h < 10(12.3) h(-1)M(circle dot) in the redshift range 0.4 < z < 1.9. (4) The star formation efficiencies (SFEs) of central galaxies reveal a "downsizing" behavior, in that the halo "quenching" mass, at which the SFE peaks, shifts from similar to 10(12.5) h(-1)M(circle dot) at z greater than or similar to 3.5 to similar to 10(11.3) h(-1)M(circle dot) at z = 0. (5) At redshift z greater than or similar to 2.5 more than 99% of the stars in the progenitors of massive galaxies are formed in situ, and this fraction decreases as a function of redshift, becoming similar to 60% at z = 0. For a Milky-Way-sized halo of M-h similar to 10(12) h(-1)M(circle dot) more than 80% of all the stars are formed in situ, as opposed to having been accreted from satellite galaxies
Efficient transfer hydrogenation of alkyl levulinates to γ-valerolactone catalyzed by simple Zr–TiO2 metal oxide systems
No full textZr–TiO2 synthesized heterogeneous catalysts could efficiently convert ethyl levulinates (ELs) to γ-valerolactone (GVL) using isopropanol (2-PrOH) as H-donor. Obtained catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), High revolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma optical emission spectroscopy (ICP-OES), NH3/CO2 temperature programmed desorption (NH3/CO2-TPD), pyridine-infrared spectroscopy, H2 temperature-programmed reduction (H2-TPR), and N2 adsorption and desorption measurements. In total, 10 wt% Zr–TiO2 with average nanoparticle sizes (ca. 4–6 nm) exhibited optimum catalytic activity after optimization of reaction temperature, reaction time, catalyst loading, as well as solvent effect. GVL yield reached 74% with 79% EL conversion at 190 °C for 5 h over 10 wt% Zr–TiO2 in 2-PrOH. The high catalytic activity could be attributed to an appropriate proportion of acidic/basic sites, high Brønted/Lewis acid ratio, and large surface areas. Both acidic and basic sites lead to a synergistic effect on the concurrent activation of H-donor and substrate. The major side product ethyl 4-hydroxypentanoate (EHP) and other byproducts were found. GVL yield achieved from methyl levulinate (ML) and levulinic acid (LA) were 65% and 20%, respectively. Catalyst deactivation was observed due to coke deposits on the catalyst's surface. The spent catalyst proved to be reusable to recover almost completely its initial activity after calcination (300 °C, 2 h). A plausible reaction mechanism is presented on the basis of characterization results
Study on the Effect of Silicon Morphology on the Hardness and Wear Resistance of the A390 Alloy
No full textNew Lu(III)-containing heteropoly salt with peacock–weakley type anion Na9[Lu(W5O18)2]·42H2O: synthesis and crystal structure
No full textNew neutral sodium salt with Peacock-Weakley type anion Na9[Lu(W5O18)2]·42H2O and Lu(III) as heteroatom was synthesized using procedure, elaborated in (Mariichak O.Yu., et al. Patent of Ukraine No. 121322, 2017). The crystalline compound was obtained from the aqueous solution acidified up to Z=0.80 (Z=ν(H+ )/ν(WO4 2- )) from Lu(NO3)3–Na2WO4–HNO3– H2O system
- …
