Covalently Linked Porphyrins as One-Dimensional Conductors

We apply first-principles calculations to address the problem of the formation and characterization of covalently linked porphyrin-like structures. We show that upon pressure a rehybridization process takes place which leads to one-dimensional compounds resembling nanothreads, in which carbon atoms are all 4-fold coordinated. We also show that the resulting nanostructures have metallic character and possess remarkable mechanical properties. Moreover, in the case of porphyrin–metal complexes, we find that the covalently linked structures may be a platform for the stabilization of straight metallic wires

Insights into the genome and proteome of <i>Sphingomonas paucimobilis</i> strain 20006FA involved in the regulation of polycyclic aromatic hydrocarbon degradation

In order to study the mechanisms regulating the phenanthrene degradation pathway and the intermediate-metabolite accumulation in strain S. paucimobilis 20006FA, we sequenced the genome and compared the genome-based predictions to experimental proteomic analyses. Physiological studies indicated that the degradation involved the salicylate and protocatechuate pathways, reaching 56.3% after 15 days. Furthermore, the strain degraded other polycyclic aromatic hydrocarbons (PAH) such as anthracene (13.1%), dibenzothiophene (76.3%), and fluoranthene. The intermediate metabolite 1-hydroxy2-naphthoic acid (HNA) accumulated during phenanthrene catabolism and inhibited both bacterial growth and phenanthrene degradation, but exogenous-HNA addition did not affect further degradation. Genomic analysis predicted 126 putative genes encoding enzymes for all the steps of phenanthrene degradation, which loci could also participate in the metabolism of other PAH. Proteomic analysis identified enzymes involved in 19 of the 23 steps needed for the transformation of phenanthrene to trichloroacetic-acid intermediates that were upregulated in phenanthrene cultures relative to the levels in glucose cultures. Moreover, the protein-induction pattern was temporal, varying between 24 and 96 h during phenanthrene degradation, with most catabolic proteins being overexpressed at 96 h—e. g., the biphenyl dioxygenase and a multispecies (2Fe–2S)-binding protein. These results provided the first clues about regulation of expression of phenanthrene degradative enzymes in strain 20006FA and enabled an elucidation of the metabolic pathway utilized by the bacterium. To our knowledge the present work represents the first investigation of genomic, proteomic, and physiological studies of a PAH-degrading Sphingomonas strain.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Human biogeography and faunal exploitation in Diamante River basin, central western Argentina

A biogeographic model used to describe human peopling of southern Mendoza, central western Argentina, proposed an intensification process activated by an increase in population growth rate during the Late Holocene. During this process, high-ranked resources at the surroundings of residential camps were depleted, and hunter–gatherers broadened their diet by incorporating a larger number of low-ranked prey and domesticated plant resources. In this paper, we evaluate an alternative hypothesis, focusing on zooarchaeological data from the Diamante River basin. The results show that faunal resource intensification does not appear to have occurred in the Diamante River basin during the Late Holocene. Faunal consumption in Diamante River basin mainly reflects the local fauna in each ecological zone. The data do not show a lack of higher ranked resources. We suggest it is more likely that the demographic increase was not significant enough to cause an impact on the faunal resources. The archaeological evidence should be improved and analysed in smaller scales to continue with the intensification debate.Fil: Otaola, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giardina, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Franchetti, Fernando Ricardo. University of Pittsburgh at Johnstown; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A theoretical study of the structural phases of Group 5B - 6B metals and their transport properties

In order to predict the stable and metastable phases of the bcc metals in the block of the Periodic Table defined by groups 5B to 6B and periods 4 to 6, as well as the structure dependence of their transport properties, we have performed full potential computations of the total energies per unit cell as a function of the c/a ratio at constant experimental volume. In all cases, a metastable body centered tetragonal (bct) phase was predicted from the calculations. The total energy differences between the calculated stable and metastable phases ranged from 0.09 eV/cell (vanadium) to 0.39 eV/cell (tungsten). The trends in resistivity as a function of structure and atomic number are discussed in terms of a model of electron transport in metals. Theoretical calculations of the electrical resistivity and other transport properties show that bct phases derived from group 5B elements are more conductive than the corresponding bcc phases, while bct phases formed from group 6B elements are less conductive than the corresponding bcc phases. Special attention is paid to the phases of tantalum where we show that the frequently observed beta phase is not a simple tetragonal distortion of bcc tantalum

Effect of the addition of β-mannanase on the performance, metabolizable energy, amino acid digestibility coefficients, and immune functions of broilers fed different nutritional levels

Three experiments were conducted to evaluate the effect of β-mannanase (BM) supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels (NL) were formulated to meet the nutritional requirements of broilers (NL1); reductions of 100 kcal metabolizable energy (NL2); 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain (BWG) and increased (P < 0.05) feed conversion (FCR) for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance, energy values, and TIDc levels of amino acids and immune response of broilers

The Role of Bottom Friction in Mediating the Response of the Weddell Gyre Circulation to Changes in Surface Stress and Buoyancy Fluxes

Abstract The Weddell Gyre is one of the dominant features of the Southern Ocean circulation and its dynamics have been linked to processes of climatic relevance. Variability in the strength of the gyre’s horizontal transport has been linked to heat transport toward the Antarctic margins and changes in the properties and rates of export of bottom waters from the Weddell Sea region to the abyssal global ocean. However, the precise physical mechanisms that force variability in the Weddell’s lateral circulation across different time scales remain unknown. In this study, we use a barotropic vorticity budget from a mesoscale eddy active model simulation to attribute changes in gyre strength to variability in possible driving processes. We find that the Weddell Gyre’s circulation is sensitive to bottom friction associated with the overflowing dense waters at its western boundary. In particular, an increase in the production of dense waters at the southwestern continental shelf strengthens the bottom flow at the gyre’s western boundary, yet this drives a weakening of the depth-integrated barotropic circulation via increased bottom friction. Strengthening surface winds initially accelerate the gyre, but within a few years the response reverses once dense water production and export increases. These results reveal that the gyre can weaken in response to stronger surface winds, putting into question the traditional assumption of a direct relationship between surface stress and gyre strength in regions where overflowing dense water forms part of the depth-integrated flow.</jats:p

Evaluación de las características hidroquímicas de antiguos cauces del Río Dulce en Villa Nueva, provincia de Santiago del Estero

El acceso al agua segura, en pequeñas localidades como Villa Nueva, es un problema de vieja data. El Área de estudio está situada en el sector SO de la provincia de Santiago del Estero, y geomorfológicamente se ubica en el tramo medio de la Llanura Aluvial del Río Dulce. Se caracteriza por una sucesión de antiguos cauces colmatados y entrelazados. El trabajo de investigación se orientó hacia la caracterización hidroquímica del acuífero libre, y su utilización como soporte de almacenamiento y de recarga en forma natural o artificial, para el abastecimiento de agua destinada al consumo humano. Mediante perforaciones se realizaron estudios granulométricos de los sedimentos que permitieron obtener una aproximación acerca de la permeabilidad. Los análisis físico-químicos de las muestras de agua obtenidas, no superan los límites tolerables de las aguas seguras, excepto una de ellas, que supera la concentración de sulfatos.Access to safe water, in small towns like Villa Nueva, is a long-standing problem. The research area is located in the SW sector of the province of Santiago del Estero, and geomorphologically is located in the middle stretch of the Dulce River Floodplain. It is characterized by a succession of former channels silted and intertwined. The research work was oriented towards free aquifer hydrochemical characterization, and their use as storage media and recharge in natural or artificial, for the supply of water for human consumption. Through perforations were made sediments grain size determination studies, we have obtained an approximation concerning permeability. The physico-chemical analysis of water samples obtained do not exceed tolerable limits of safe water, except one, which exceeds the concentration of sulfates.Universidad Nacional de La Plat

Electromechanical Modulations in Transition Metal Dichalcogenide Nanosheets: Implications for Environmental Sensors

Transition metal dichalcogenides (TMDs) are key players in the two-dimensional materials nanoarena due to their exquisite optoelectronic properties under a standard environment (room temperature and atmospheric pressure). Nevertheless, as reported in the literature, they may also portray interesting physical properties under different environments. Here, we show two distinct and significant electromechanical modulations in TMD nanosheets which are tuned by the environmental conditions (applied pressure and adsorbents). Using scanning probe microscopy techniques, we modify the environmental conditions and observe steplike rises in the electrical response of all studied TMDs (MoS2, WS2, MoSe2, and WSe2—monolayers and few layers). Ab initio calculations enable full understanding of specific mechanisms behind these electromechanical modulations, which may find important applications in the design of TMD-based environmental sensors

The Gonium pectorale genome demonstrates co-option of cell cycle regulation during the evolution of multicellularity

Citation: Hanschen, E. R., Marriage, T. N., Ferris, P. J., Hamaji, T., Toyoda, A., Fujiyama, A., . . . Olson, B. (2016). The Gonium pectorale genome demonstrates co-option of cell cycle regulation during the evolution of multicellularity. Nature Communications, 7, 10. doi:10.1038/ncomms11370Additional Authors: Anderson, J.;Bakaric, R.;Luria, V.;Karger, A.;Kirschner, M. W.;Durand, P. M.;Michod, R. E.;Nozaki, H.The transition to multicellularity has occurred numerous times in all domains of life, yet its initial steps are poorly understood. The volvocine green algae are a tractable system for understanding the genetic basis of multicellularity including the initial formation of cooperative cell groups. Here we report the genome sequence of the undifferentiated colonial alga, Gonium pectorale, where group formation evolved by co-option of the retinoblastoma cell cycle regulatory pathway. Significantly, expression of the Gonium retinoblastoma cell cycle regulator in unicellular Chlamydomonas causes it to become colonial. The presence of these changes in undifferentiated Gonium indicates extensive group-level adaptation during the initial step in the evolution of multicellularity. These results emphasize an early and formative step in the evolution of multicellularity, the evolution of cell cycle regulation, one that may shed light on the evolutionary history of other multicellular innovations and evolutionary transitions

Update on a pilot study: Flumeltbi peripheral blood HLAhaploidentical stem cell transplantation with post-transplant cyclophosphamide and bortezomib (Cy2Bor3)

Background: Bortezomib (Bor) can inhibit the proliferation of dendritic cells (DCs) and block the expression of co-receptors CD80, CD86 and secretion of cytokines IL-12 and TNF-α and hence the ability of DCs to activate T cells. We started a pilot study incorporating the addition of bortezomib to post-transplant cyclophosphamide (PTCY) in the setting of peripheral blood (PB) HLA-haploidentical stem cell transplantation (Haplo-SCT). Methods: This is a single center open label pilot study. Eligible patients received Fludarabine Melphalan TBI 200 cGy as conditioning followed by haplo-SCT and PTCY. Bor was administered at 1.3mg/m2 on day+1, 4 and 7. Tacrolimus and MMF were started at day+5. Results: Seven patients were enrolled so far, five males and 2 females. Median age was 58 years (26-60). Donors were 3 brothers, 3 sons and 1 mother. Disease risk index was high in 3, intermediate in 3 and low in 1. Three patients had AML, two had ALL and MM, one had ALL and one had CML. CMV recipient status was negative in one and positive in 6. Median HCT-CI was 3(1-4). Median CD34 and CD3 infused were 4.13 x10-6 and 1.7x10-8/ kg recipient respectively, all were cryopreserved except 2. Four patients had CRS before Cy infusion with ASTCT grade of 1. Six patients had grade 3 hypokalemia around day+ 4-5. Five patients had grade 3 mucositis and 2 had grade 1. Four patients had neutropenic fever and one patient had engraftment fever. Median neutrophils and platelets engraftment were 16 and 26 days respectively. Chimerism post SCT was \u3e =99% donor at day 30 for all patients. Six patients are off tacrolimus with median time to be off it was 187.5 days. Five pts had aGVHD with maximum grade of I in 3 patients, II in one patient and III in one patient at a median 50days post SCT. None developed early hematuria, four had late hematuria with highest grade of 4. Two patients were positive for BK virus. One patient had reactivation of CMV, 2 had EBV and one had adenovirus, all resolved. Three pts had HHV6 that resolved. Of the 5 patients who were evaluable, one developed moderate chronic GVHD. So far the median time to follow up is 455 days (70-1239) with relapse and subsequently death in one patient who had high risk AML with 3 different inductions prior to SCT. . At 1 year for 4 evaluable patients IgG were \u3e400 mg/dl and CD4 \u3e 350 cells/ul. Conclusions: Cy2Bor3 post PB Haplo-SCT was well tolerated. Although small number of patients and limited but encouraging results so far. The trial is ongoing