Hydroxylated phosphines as ligands for chalcogenide clusters: self assembly, transformations and stabilization

This contribution is a documentation of recent advances in the chemistry of chalcogenide polynuclear transition metal complexes coordinated with mono- and di-phosphines functionalized with hydroxo groups. A survey of complexes containing tris(hydroxymethyl)phosphine (THP) is presented. The influence of the alkyl chain in bidentate phosphines, bearing the P–(CH2)x–OH arms, is also analyzed. Finally, isolation and structure elucidation of the complexes with HP(OH)2, P(OH)3, As(OH)3, PhP(OH)2, stabilized by coordination to Ni(0) and Pd(0) centers embedded into chalcogenide clusters, is discussed

Efecto de lixiviados del raquis de plátano sobre la actividad y biomasa microbiana en floración y cosecha del tomate

Se utilizaron cinco tratamientos: el testigo (T0) y cuatro concentraciones de lixiviados (T1= 100%, T2= 75%, T3= 50% y T4= 25%) aplicados 15, 30 y 60 días después del trasplante. La actividad microbiana se determinó con la metodología del CAB y la biomasa microbiana con el método de fumigación-extracción. En la actividad microbiana se encontraron diferencias significativas entre los tratamientos, presentando la aplicación del lixiviado a la menor concentración (25%) la mayor actividad (56.76 mgCO2g suelo-1). La actividad fue mayor en floración en todos los tratamientos. Para biomasa microbiana no se presentaron diferencias significativas entre los tratamientos ni entre épocas. ABSTRACT The effect of leaching from rachis on soil microbial biomass and activity during tomato flowering and harvesting period. Field trail comprised five treatments of different leaching concentrations (T0= test, T1= 100%, T2= 75%, T3=50%, and T4=25%) sprinkled on soil 15, 30 and 60 days after tomato transplanting. Microbial activity was measured with CAB method and microbial biomass was recorded with fumigation - extraction method. The average microbial activity with sprinking of 25% of leaching was higher (56.76 mgCO2g suelo-1). No significant difference in order to treatments and periods in microbial biomass were observed. These observations showed leaching sprinkling in low concentration influence en microbial activity for the conditions of this experiment. Key words: Soil biology, biomass, leaching, Lycopersicum sculentun

Crocus sativus L. Ecotypes from Mediterranean Countries: Phenological, Morpho-Productive, Qualitative and Genetic Traits

The characterization of C. sativus ecotypes is of great interest for preserving them from a possible genetic erosion due to the decrease of European cultivation surface. In this study, we evaluated four ecotypes from Italy (Sardinia and Abruzzo), Spain (Castilla-La Mancha), and Greece (Kozani) in order to detect the existence of variability and promote the biodiversity of this crop. Thirty-one traits related to saffron flowering, flower morphology, production of spice and daughter corms, vegetative development (leaf and corm traits), and spice quality, were evaluated. In addition, a genetic analysis through three PCR-based approaches, SSRs, RAPD, and SRAP was assessed. Results highlighted a phenotypic variation among ecotypes during two consecutive years. All the studied parameters were influenced by the ecotype except for the stamen length, color coordinates of tepals, leaf length, and leaf number per plant. Sardinia had a longer flowering interval, earlier flowering, and higher spice yield and quality than the other corm origins. The maximum values of morphological traits, such as stigma length, dry weight of stigmas, tepals, flowers and leaves, leaf area, and daughter corm weight were observed in the Abruzzo ecotype. Principal component analysis (PCA) showed a clear separation among ecotypes, in which Sardinia and Spain showed more similarities than Abruzzo and Kozani. Significant negative correlation was found between days to flower with stigma yield and quality. However, we could not find molecular markers discriminating among corm origins. In conclusion, this study suggests the importance of C. sativus ecotypes as precious source of biodiversity and bioactive compounds, and of their enhancement as fundamental prerequisite for a sustainable development strategy and as an agricultural diversification opportunity for growers

Patterns of coral-reef finfish species disappearances inferred from fishers' knowledge in global epicentre of marine shorefish diversity

In the Philippines, very high fishing pressure coincides with the globally greatest number of shorefish species, yet no long-term fisheries data are available to explore species-level changes that may have occurred widely in the most species rich and vulnerable marine ecosystem, namely coral reefs. Through 2655 face-to-face interviews conducted between August 2012 and July 2014, we used fishers' recall of past catch rates of reef-associated finfish to infer species disappearances from catches in five marine key biodiversity areas (Lanuza Bay, Danajon Bank, Verde Island Passage, Polillo Islands and Honda Bay). We modeled temporal trends in perceived catch per unit effort (CPUE) based on fishers' reports of typical good days' catches using Generalized Linear Mixed Modelling. Fifty-nine different finfish disappeared from catches between the 1950s and 2014; 42 fish were identified to species level, two to genus, seven to family and eight to local name only. Five species occurring at all sites with the greatest number of fishers reporting zero catches were the green bumphead parrotfish (Bolbometopon muricatum), humphead wrasse (Cheilinus undulatus), African pompano (Alectis ciliaris), giant grouper (Epinephelus lanceolatus) and mangrove red snapper (Lutjanus argentimaculatus). Between the 1950s and 2014, the mean perceived CPUE of bumphead parrotfish declined by 88%, that of humphead wrasse by 82%, African pompano by 66%, giant grouper by 74% and mangrove red snapper by 64%. These declines were mainly associated with excess and uncontrolled fishing, fish life-history traits like maximum body size and socio-economic factors like access to market infrastructure and services, and overpopulation. The fishers' knowledge is indicative of extirpations where evidence for these losses was otherwise lacking. Our models provide information as basis for area-based conservation and regional resource management particularly for the more vulnerable, once common, large, yet wide-ranging reef finfish species

Intergroup conflict and rational decision making

The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict ¿associated with indicators of the activation of negative feelings (negative affect state and heart rate)¿ has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making

INTEGRAL observations of AGN obscured by the Galactic Plane

In this paper we present INTEGRAL observations of 7 AGNs: two newly discovered type 1 Seyferts, IGR J18027-1455 and IGR J21247+5058, and five well known Seyferts, NGC 6814 (type 1.5), Cyg A (Type 2), MCG-05-23-16 (type 2), ESO 103-G035 (type2) and GRS1734-292. For IGR J18027-1455 and IGR J21247+5058 only INTEGRAL/IBIS data were available, while broadband spectra are presented and discussed for the remaining 5 sources for which either BeppoSAX or ASCA data were used in conjunction with INTEGRAL measurements. In the cases of NGC 6814 and GRS 1734-292, data taken in different periods indicate variability in the flux: in the case of NGC 6814 by a factor of 16 over a period of about 10 years. Although limited in size, our sample can be used to investigate the parameter space of both the photon index and cut-off energy. The mean photon index is 1.8, while the cut-off energy ranges from 30-50 keV to greater than 200 keV; in the particular case of MCG-05-23-16, ESO 103-G035 and GRS 1734-292 the cut-off energy is well constrained at or below 100 keV. We have also tested an enlarged sample, which includes INTEGRAL data of 3 more AGNs, against the correlation found by a number of authors between the photon index and the cut-off energy but have found no evidence for a relation between these two parameters. Our analysis indicates that there is a diversity in cut-off energies in the primary continuum of Seyfert galaxies.Comment: 8 pages, 10 figures, accepted for pubblication on MNRA

Ectopic expression of the AtCDF1 transcription factor in potato enhances tuber starch and amino acid contents and yield under open field conditions

Introduction Cycling Dof transcription factors (CDFs) have been involved in different aspects of plant growth and development. In Arabidopsis and tomato, one member of this family (CDF1) has recently been associated with the regulation of primary metabolism and abiotic stress responses, but their roles in crop production under open field conditions remain unknown. Methods In this study, we compared the growth, and tuber yield and composition of plants ectopically expressing the CDF1 gene from Arabidopsis under the control of the 35S promoter with wild-type (WT) potato plants cultured in growth chamber and open field conditions. Results In growth chambers, the 35S::AtCDF1 plants showed a greater tuber yield than the WT by increasing the biomass partition for tuber development. Under field conditions, the ectopic expression of CDF1 also promoted the sink strength of the tubers, since 35S::AtCDF1 plants exhibited significant increases in tuber size and weight resulting in higher tuber yield. A metabolomic analysis revealed that tubers of 35S::AtCDF1 plants cultured under open field conditions accumulated higher levels of glucose, starch and amino acids than WT tubers. A comparative proteomic analysis of tubers of 35S::AtCDF1 and WT plants cultured under open field conditions revealed that these changes can be accounted for changes in the expression of proteins involved in energy production and different aspects of C and N metabolism. Discussion The results from this study advance our collective understanding of the role of CDFs and are of great interest for the purposes of improving the yield and breeding of crop plants

Reverberation Mapping of the Seyfert 1 Galaxy NGC 7469

A large reverberation mapping study of the Seyfert 1 galaxy NGC 7469 has yielded emission-line lags for Hbeta 4861 and He II 4686 and a central black hole mass measurement of about 10 million solar masses, consistent with previous measurements. A very low level of variability during the monitoring campaign precluded meeting our original goal of recovering velocity-delay maps from the data, but with the new Hbeta measurement, NGC 7469 is no longer an outlier in the relationship between the size of the Hbeta-emitting broad-line region and the AGN luminosity. It was necessary to detrend the continuum and Hbeta and He II 4686 line light curves and those from archival UV data for different time-series analysis methods to yield consistent results.Comment: 9 Pages, 7 figures, 6 tables. Accepted for publication in The Astrophysical Journa

MYC directly transactivates CR2/CD21, the receptor of the Epstein-Barr virus, enhancing the viral infection of Burkitt lymphoma cells.

MYC is an oncogenic transcription factor dysregulated in about half of total human tumors. While transcriptomic studies reveal more than 1000 genes regulated by MYC, a much smaller fraction of genes is directly transactivated by MYC. Virtually all Burkitt lymphoma (BL) carry chromosomal translocations involving MYC oncogene. Most endemic BL and a fraction of sporadic BL are associated with Epstein-Barr virus (EBV) infection. The currently accepted mechanism is that EBV is the BL-causing agent inducing MYC translocation. Herein we show that the EBV receptor, CR2 (also called CD21), is a direct MYC target gene. This is based on several pieces of evidence: MYC induces CR2 expression in both proliferating and arrested cells and in the absence of protein synthesis, binds the CR2 promoter and transactivates CR2 in an E-box-dependent manner. Moreover, using mice with conditional MYC ablation we show that MYC induces CR2 in primary B cells. Importantly, modulation of MYC levels directly correlates with EBV's ability of infection in BL cells. Altogether, in contrast to the widely accepted hypothesis for the correlation between EBV and BL, we propose an alternative hypothesis in which MYC dysregulation could be the first event leading to the subsequent EBV infection.S

Water-Soluble Mo3S4 Clusters Bearing Hydroxypropyl Diphosphine Ligands: Synthesis, Crystal Structure, Aqueous Speciation, and Kinetics of Substitution Reactions

The [Mo3S4Cl3(dhprpe)3]+ (1+) cluster cation has been prepared by reaction between Mo3S4Cl4(PPh3)3 (solvent)2 and the watersoluble 1,2-bis(bis(hydroxypropyl)phosphino)ethane (dhprpe, L) ligand. The crystal structure of [1]2[Mo6Cl14] has been determined by X-ray diffraction methods and shows the typical incomplete cuboidal structure with a capping and three bridging sulfides. The octahedral coordination around each metal center is completed with a chlorine and two phosphorus atoms of the diphosphine ligand. Depending on the pH, the hydroxo group of the functionalized diphosphine can substitute the chloride ligands and coordinate to the cluster core to give new clusters with tridentate deprotonated dhprpe ligands of formula [Mo3S4(dhprpe-H)3]+ (2+). A detailed study based on stopped-flow, 31P{1H} NMR, and electrospray ionization mass spectrometry techniques has been carried out to understand the behavior of acid−base equilibria and the kinetics of interconversion between the 1+ and the 2+ forms. Both conversion of 1+ to 2+ and its reverse process occur in a single kinetic step, so that reactions proceed at the three metal centers with statistically controlled kinetics. The values of the rate constants under different conditions are used to discuss on the mechanisms of opening and closing of the chelate rings with coordination or dissociation of chloride