Effects of typhoons on gelatinous carnivore zooplankton off Northern Taiwan

We examine the effect of typhoons, as potential drivers of nutrient pulse events, on gelatinous carnivore zooplankton. The period investigated spanned from 2007 to 2010, where seasonal abundance and taxonomic composition of the gelatinous zooplankton community was recorded off North Taiwan. Typhoon effects were assessed in the abundance, diversity and species richness of the gelatinous carnivore populations. Significant associations between typhoons and gelatinous carnivores were found in time delays varying from 3 to 25 days, but no association was identified for longer time intervals. Generally, a decrease in species richness occurred during the summer season, and this was accentuated in 2008, shortly after typhoons events. We hypothesize that typhoons might act as resource pulse triggers probably enhancing open niches for opportunistic carnivore zooplankton groups

Stereoselectivity in Metallocene-Catalyzed Coordination Polymerization of Renewable Methylene Butyrolactones: From Stereo-random to Stereo-perfect Polymers

Coordination polymerization of renewable α-methylene-γ-(methyl)butyrolactones by chiral C2-symmetric zirconocene catalysts produces stereo-random, highly stereo-regular, or perfectly stereo-regular polymers, depending on the monomer and catalyst structures. Computational studies yield a fundamental understanding of the stereocontrol mechanism governing these new polymerization reactions mediated by chiral metallocenium catalysts

Weighted Barycentric Sets and Singular Liouville Equations on Compact Surfaces

Given a closed two dimensional manifold, we prove a general existence result for a class of elliptic PDEs with exponential nonlinearities and negative Dirac deltas on the right-hand side, extending a theory recently obtained for the regular case. This is done by global methods: since the associated Euler functional is in general unbounded from below, we need to define a new model space, generalizing the so-called space of formal barycenters and characterizing (up to homotopy equivalence) its very low sublevels. As a result, the analytic problem is reduced to a topological one concerning the contractibility of this model space. To this aim, we prove a new functional inequality in the spirit of [16] and then we employ a min-max scheme based on a cone-style construction, jointly with the blow-up analysis given in [5] (after [6] and [8]). This study is motivated by abelian Chern- Simons theory in self-dual regime, or from the problem of prescribing the Gaussian curvature in presence of conical singularities (hence generalizing a problem raised by Kazdan and Warner in [26]).Comment: to appear on Journal of Functional Analysis. One proof in Section 3 has been simplified with respect to the previous version, while Section 6 (on open problems) has been substantially improved. At the end on the Introduction, the complete proof of the topological conjecture given in Section 6 (to appear in a forthcoming paper) is announce

Sudanske dvosupnice kao alternativni izvor vlakana za proizvodnju celuloze i papira

The suitability of the stems from two Sudanese dicotyledonous annual plants, namely castor bean (Ricinus communis) and Leptadenia pyrotechnica (L. pyrotechnica) were investigated for pulp and papermaking. Chemical compositions, elemental analysis, fiber dimensions, paper physical properties and morphology revealed a relatively high α-cellulose content (46.2 and 44.3 %) and low lignin (19.7 and 21.7 %) in the stems of castor bean and L. pyrotechnica, respectively. The average fiber length of castor bean and L. pyrotechnica is 0.80 and 0.70 mm with fiber width of 16.30 μm and 18.20 μm, respectively, which makes them acceptable candidates. Soda-AQ pulping of castor bean stem led to a higher pulp yield of 43.2 % at kappa number 18.2 compared to 40.3 % at kappa 20.3 for L. pyrotechnica. This yield is less than that obtained for wood plants and similar to that observed for annual plants. Paper handsheets produced from castor bean showed better mechanical properties than L. pyrotechnica. SEM images indicated that the produced papers were quite homogeneous, compact, closely packed, and well assembled.U radu je opisano istraživanje prikladnosti stabljika dviju sudanskih jednogodišnjih biljaka dvosupnica, ricinusa (Ricinus communis) i Leptadenia pirotechnica za dobivanje celulozu i proizvodnju papira. Kemijski sastav, elementarna analiza, dimenzije vlakana, fizikalna svojstva papira i morfologija pokazali su da je u stabljikama ricinusa i L. pyrotechnica relativno visok sadržaj α-celuloze (46,2 i 44,3 %) i nizak sadržaj lignina (19,7 i 21,7 %). Prosječna duljina vlakana ricinusa i L. pirotechnice iznosi 0,80 i 0,70 mm, a širina vlakana im je od 16,30 μm i 18,20 μm, što ih čini prihvatljivima za proizvodnju celuloze i papira. Sulfatnim je postupkom od stabljika ricinusa dobiven veći prinos celuloze (43,2 %) pri kappa broju 18,2 u usporedbi s prinosom celuloze (40,3 %) pri kappa broju 20,3, koji je dobiven pri proizvodnji celuloze od stabljika L. pyrotechnice. Dobiveni prinos manji je od prinosa koji se postiže proizvodnjom celuloze od drvenastih biljaka i jednak je prinosu koji se ostvaruje proizvodnjom celuloze od jednogodišnjih biljaka. Listovi papira proizvedeni od ricinusa pokazali su bolja mehanička svojstva od papira proizvedenoga od stabljika L. pyrotechnice. Slike dobivene skenirajućim elektronskim mikroskopom (SEM) pokazuju da su proizvedeni papiri bili posve homogeni, kompaktni, zbijeni i dobro sastavljeni

Accurate Kohn-Sham auxiliary system from the ground state density of solids

The Kohn-Sham (KS) system is an auxiliary system whose effective potential is unknown in most cases. It is in principle determined by the ground state density, and it has been found numerically for some low-dimensional systems by inverting the KS equations starting from a given accurate density. For solids, only approximate results are available. In this work, we determine accurate exchange correlation (xc) potentials for Si and NaCl using the ground state densities obtained from Auxiliary Field Quantum Monte Carlo calculations. We show that these xc potentials can be rationalized as an ensemble of environment-adapted functions of the local density. The KS band structure can be obtained with high accuracy. The true KS band gap turns out to be larger than the prediction of the local density approximation, but significantly smaller than the measurable photoemission gap, which confirms previous estimates. Finally, our findings show that the conjecture that very different xc potentials can lead to very similar densities and other KS observables is true also in solids, which questions the meaning of details of the potentials and, at the same time, confirms the stability of the KS system

Autophagy occurs upstream or parallel to the apoptosome during histolytic cell death

Histolysis refers to a widespread disintegration of tissues that is morphologically distinct from apoptosis and often associated with the stimulation of autophagy. Here, we establish that a component of the apoptosome, and pivotal regulator of apoptosis, is also required for histolytic cell death. Using in vivo and ex vivo assays, we demonstrate a global apoptogenic requirement for dark, the fly ortholog of Apaf1, and show that a required focus of dark– organismal lethality maps to the central nervous system. We further demonstrate that the Dark protein itself is a caspase substrate and find that alterations of this cleavage site produced the first hypermorphic point mutation within the Apaf1/Ced-4 gene family. In a model of ‘autophagic cell death’, dark was essential for histolysis but dispensable for characteristic features of the autophagic program, indicating that the induction of autophagy occurs upstream or parallel to histolytic cell death. These results demonstrate that stimulation of autophagy per se is not a ‘killing event’ and, at the same time, establish that common effector pathways, regulated by the apoptosome, can underlie morphologically distinct forms of programmed cell death

Unusual C–C Bond Cleavage in the Formation of Amine-Bis(phenoxy) Group 4 Benzyl Complexes: Mechanism of Formation and Application to Stereospecific Polymerization

Group 4 tetrabenzyl compounds MBn4 (M = Zr, Ti), upon protonolysis with an equimolar amount of the tetradentate amine-tris(phenol) ligand N[(2,4-tBu2C6H2(CH2)OH]3 in toluene from −30 to 25 °C, unexpectedly lead to amine-bis(phenoxy) dibenzyl complexes, BnCH2N[(2,4-tBu2C6H2(CH2)O]2MBn2 (M = Zr (1), Ti (2)) in 80% (1) and 75% (2) yields. This reaction involves an apparent cleavage of the >NCH2–ArOH bond (loss of the phenol in the ligand) and formation of the >NCH2–CH2Bn bond (gain of the benzyl group in the ligand). Structural characterization of 1 by X-ray diffraction analysis confirms that the complex formed is a bis(benzyl) complex of Zr coordinated by a newly derived tridentate amine-bis(phenoxy) ligand arranged in a mer configuration in the solid state. The abstractive activation of 1 and 2 with B(C6F5)3·THF in CD2Cl2 at room temperature generates the corresponding benzyl cations {BnCH2N[(2,4-tBu2C6H2(CH2)O]2MBn(THF)}+[BnB(C6F5)3]− (M = Zr (3), Ti, (4)). These cationic complexes, along with their analogues derived from (imino)phenoxy tri- and dibenzyl complexes, [(2,6-iPr2C6H3)N═C(3,5-tBu2C6H2)O]ZrBn3 (5) and [2,4-Br2C6H2(O)(6-CH2(NC5H9))CH2N═CH(2-adamantyl-4-MeC6H2O)]ZrBn2 (6), have been found to effectively polymerize the biomass-derived renewable β-methyl-α-methylene-γ-butyrolactone (βMMBL) at room temperature into the highly stereoregular polymer PβMMBL with an isotacticity up to 99% mm. A combined experimental and DFT study has yielded a mechanistic pathway for the observed unusual C–C bond cleavage in the present protonolysis reaction between ZrBn4 and N[(2,4-tBu2C6H2(CH2)OH]3 for the formation of complex 1, which involves the benzyl radical and the Zr(III) species, resulting from thermal and photochemical decomposition of ZrBn4, followed by a series of reaction sequences consisting of protonolysis, tautomerization, H-transfer, oxidation, elimination, and radical coupling

The impact of a mobile phone-delivered digital financial education program on financial behavior among Hispanics

We explored the potential of digital financial education programs among Hispanic populations, through the design and evaluation of a mobile phone delivered digital program called Mind Your Money (MYM). This program sought to improve financial knowledge and behavior among low- to-moderate income Hispanics residing in the Greater Los Angeles area. We assessed the program through a randomized controlled trial with a wait-list control group. Our digital financial education program had a higher retention rate than comparable in-person financial coaching programs. We found that our program had a positive statistical significant effect on financial capability. Participants who completed program activities were more likely to have a budget/spending plan and felt more confident about their ability to pay for unexpected expenses

The Many Manifestations of Downsizing: Hierarchical Galaxy Formation Models confront Observations

[abridged] It has been widely claimed that several lines of observational evidence point towards a "downsizing" (DS) of the process of galaxy formation over cosmic time. This behavior is sometimes termed "anti-hierarchical", and contrasted with the "bottom-up" assembly of the dark matter structures in Cold Dark Matter models. In this paper we address three different kinds of observational evidence that have been described as DS: the stellar mass assembly, star formation rate and the ages of the stellar populations in local galaxies. We compare a broad compilation of available data-sets with the predictions of three different semi-analytic models of galaxy formation within the Lambda-CDM framework. In the data, we see only weak evidence at best of DS in stellar mass and in star formation rate. We find that, when observational errors on stellar mass and SFR are taken into account, the models acceptably reproduce the evolution of massive galaxies, over the entire redshift range that we consider. However, lower mass galaxies are formed too early in the models and are too passive at late times. Thus, the models do not correctly reproduce the DS trend in stellar mass or the archaeological DS, while they qualitatively reproduce the mass-dependent evolution of the SFR. We demonstrate that these discrepancies are not solely due to a poor treatment of satellite galaxies but are mainly connected to the excessively efficient formation of central galaxies in high-redshift haloes with circular velocities ~100-200 km/s. [abridged]Comment: MNRAS accepted, 16 pages, 10 figure