1,367 research outputs found
MALANGA (Colocasia esculenta (L.) Schott) Y CHAYOTE (Sechium edule (Jacq.) Sw.) POR MANGO ‘MANILA’ (Mangifera indica L.): CAMBIOS EN EL SISTEMA AGRÍCOLA DE LA CUENCA CENTRAL DEL RÍO ACTOPAN, VERACRUZ
The ‘Manila’ mango (M. indica) has been a product of enormous commercial value for the inhabitants of the Central basin of the Actopan River, Veracruz. At the national level, this region continues to provide the domestic market with 85 % of ‘Manila’ mango production. Despite this, production and yields per hectare at the state and regional level have declined in the last 20 years by 54 %. The present study identifies the causes that have produced the reduction in surface and production of mango ‘Manila’, one of the most emblematic crops of the state of Veracruz. The methodology is based on research of printed sources and statistics obtained through surveys applied to producers. The results show that the main causes of land use change of more than 15,220 ha in the state and a 60 % decrease in yields per hectare of ‘Manila’ mango in the region (>40 years) have low yields, the unattractive price ( 10.33 por kg), hay graves problemas de enfermedades y plagas (antracnosis y moscas de la fruta), y falta de apoyo gubernamental han motivado la sustitución por cultivos más rentables. Chayotes (Sechium edule) (29 %), malanga (Colocasia esculenta) (21 %), otros cultivares de mango (M. indica) (25 %), limón (Citrusxlatifolia Tanaca Ex Q. Jiménez) (8 %), guanábana (Annona muricata L.) (9 %), maracuyá (Passiflora edulis Sims) (8 %) entre otros, son los cultivos substitutos de las áreas anteriormente densamente arboladas con mango. Aunque el cambio en el sistema agrícola ha beneficiado económicamente a los productores, la modificación al sistema repercute en el agroecosistema en general, toda vez que los cultivos nuevos son en su mayoría altamente demandantes en agroquímicos
Lateral asymmetry of voluntary attention orienting
We recently demonstrated that automatic attention favors the right side of space and, in the present study, we investigated whether voluntary attention also favors this side. Six reaction time experiments were conducted. In each experiment, 12 new 18-25-year-old male right-handed individuals were tested. In Experiments 1, 2, 3 (a, b) and 4 (a, b), tasks with increasing attentional demands were used. In Experiments 1, 2, 3a, and 4a, attention was oriented to one or both sides by means of a central spatially informative visual cue. A left or right side visual target appeared 100, 300, or 500 ms later. Attentional effects were observed in the four experiments. In Experiments 2, 3a and 4a, these effects were greater when the cue indicated the right side than when it indicated the left side (respectively: 16 ± 10 and 44 ± 6 ms, P = 0.015, for stimulus onset asynchrony of 500 ms in Experiment 2; 38 ± 10 and 70 ± 7 ms, P = 0.011, for Experiment 3a, and 23 ± 11 and 61 ± 10 ms, P = 0.009, for Experiment 4a). In Experiments 3b and 4b, the central cue pointed to both sides and was said to be non-relevant for task performance. In these experiments right and left reaction times did not differ. The most conservative interpretation of the present findings is that voluntary attention orienting favors the right side of space, particularly when a difficult task has to be performed
Editorial: Pathway, Genetic and Process Engineering of Microbes for Biopolymer Synthesis
Indexación ScopusTogether with the climate crisis, the heavy accumulation in oceans and soils of persistent pollutants,
like polycyclic aromatics hydrocarbons and synthetic plastics, are the main drivers to impact
nature and threaten human survival. It is particularly striking that most industrial polymers
still originate from petrochemical sources—nearly 99% of the overall worldwide production. The
result is materials that remain intact for centuries once deposited in the environment. Relying on
non-renewable fossil chemicals limits our ability to establish a circular economy that promises to
curb current emissions and contribute moderately to the global carbon cycle without surpassing its
carrying capacity.
For decades, commercial biopolymers have also been produced by microbial fermentation since
nature has endowed many bacteria from urban sites to extreme environments (Orellana-Saez et
al., 2019) with the enzymatic machinery to assemble these macromolecules. Despite the rapid
pace of innovation, microbial biopolymers are still expensive to synthesize because the generally
oxygen-intensive fermentation processes, downstream processing, and carbon feedstock cost boost
production expenses (Oliveira et al., 2020). The biopolymers must additionally possess specific
mechanical and physical properties to be processed industrially into products with a variety of
applications (Moradali and Rehm, 2020).https://www.frontiersin.org/articles/10.3389/fbioe.2020.618383/ful
New and continuing developments at PROSITE.
PROSITE (http://prosite.expasy.org/) consists of documentation entries describing protein domains, families and functional sites, as well as associated patterns and profiles to identify them. It is complemented by ProRule a collection of rules, which increases the discriminatory power of these profiles and patterns by providing additional information about functionally and/or structurally critical amino acids. PROSITE signatures, together with ProRule, are used for the annotation of domains and features of UniProtKB/Swiss-Prot entries. Here, we describe recent developments that allow users to perform whole-proteome annotation as well as a number of filtering options that can be combined to perform powerful targeted searches for biological discovery. The latest version of PROSITE (release 20.85, of 30 August 2012) contains 1308 patterns, 1039 profiles and 1041 ProRules
Microbial engineering of new streptomyces sp. from extreme environments for novel antibiotics and anticancer drugs
Today there is a tremendous need for new antibiotics and novel cytotoxic compounds against cancer cells to develop efficient alternative treatment to chemotherapy. We have searched for highly active Streptomyces strains in the driest desert in the world, the Atacama desert in northern Chile. We have identified several new strains and found many novel antibiotics and anticancer agents (“Chaxamycins”, “Chaxalactins” and “Atacamycins”) from Streptomyces C34 and C38.
A genome scale model of the metabolism of Streptomyces leeuwenhoekii C34 has been developed from its genome sequence. The model, iVR1007, has 1726 reactions including 239 for transport, reactions for secondary metabolite biosynthesis, 1463 metabolites and 1007 genes. The model was validated with experimental data of growth in 89, 54 and 23 sole carbon, nitrogen and phosphorous sources, respectively, and showed a high level of accuracy (82.5 %). We have included reactions for desferrioxamines, ectoine, Chaxamycins, Chaxalactins and for the hybrid polyketides/non-ribosomal peptide synthesized by the halogenase cluster. A detailed Metabolic Flux Balance Analysis was carried out in order to study the metabolic pathways of Chaxalactins, Chaxamycins and the product of the halogenase cluster, by recognizing overexpression targets and useful knock-out sites to increase production of these secondary metabolites.
Alternatively we have identified the gene cluster in S. leeuwenhoekii C34 responsible for the biosynthesis of the Chaxamycins and Chaxalactins and have cloned the whole gene cluster in a much more efficient strain of Streptomyces, namely S. coelicolor A3 whose heterologous expression of gene clusters from other Streptomyces strains has been successfully tested. Our recent results concerning these two alternative strategies for identification and overproduction of these important secondary metabolites will be presented and discussed in this presentation
ILLUMINATING THE DARKEST GAMMA-RAY BURSTS WITH RADIO OBSERVATIONS
We present X-ray, optical, near-infrared (IR), and radio observations of gamma-ray bursts (GRBs) 110709B and 111215A, as well as optical and near-IR observations of their host galaxies. The combination of X-ray detections and deep optical/near-IR limits establish both bursts as "dark." Sub-arcsecond positions enabled by radio detections lead to robust host galaxy associations, with optical detections that indicate z ≾ 4 (110709B) and z ≈ 1.8-2.9 (111215A). We therefore conclude that both bursts are dark due to substantial rest-frame extinction. Using the radio and X-ray data for each burst we find that GRB 110709B requires A_V^(host) ≳ 5.3 mag and GRB 111215A requires A_V^(host) ≳ 8.5 mag (assuming z = 2). These are among the largest extinction values inferred for dark bursts to date. The two bursts also exhibit large neutral hydrogen column densities of N H, int ≳ 10^(22) cm^(–2) (z = 2) as inferred from their X-ray spectra, in agreement with the trend for dark GRBs. Moreover, the inferred values are in agreement with the Galactic A_V -N_H relation, unlike the bulk of the GRB population. Finally, we find that for both bursts the afterglow emission is best explained by a collimated outflow with a total beaming-corrected energy of E_γ + E_K ≈ (7-9) × 10^(51) erg (z = 2) expanding into a wind medium with a high density, Ṁ ≈ (6-20) x 10^(-5) M_☉ yr^(–1) (n ≈ 100-350 cm^(–3) at ≈ 10^(17) cm). While the energy release is typical of long GRBs, the inferred density may be indicative of larger mass-loss rates for GRB progenitors in dusty (and hence metal rich) environments. This study establishes the critical role of radio observations in demonstrating the origin and properties of dark GRBs. Observations with the JVLA and ALMA will provide a sample with sub-arcsecond positions and robust host associations that will help to shed light on obscured star formation and the role of metallicity in GRB progenitors
Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds
Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system’s capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems’ capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream) and ecosystem service demand (downstream) in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensificationFunding for the development of this research was provided by a postdoctoral grant from the Spanish National Institute for Agriculture and Food Research and Technology (INIA), which is cofunded by the Social European Fund; the Seventh Framework Programme of the European Commission (FP7, 2007-2013) under the BESAFE project (Biodiversity and Ecosystem Services: Arguments for our Future Environment, Contract No. 282743; http://www.besafe-project. net); and the OpenNESS Project (Operationalisation of Natural capital and Ecosystem Services: From Concepts to Real-World Applications, Contract No. 308428
Gemini Observations of Disks and Jets in Young Stellar Objects and in Active Galaxies
We present first results from the Near-infrared Integral Field Spectrograph
(NIFS) located at Gemini North. For the active galaxies Cygnus A and Perseus A
we observe rotationally-supported accretion disks and adduce the existence of
massive central black holes and estimate their masses. In Cygnus A we also see
remarkable high-excitation ionization cones dominated by photoionization from
the central engine. In the T-Tauri stars HV Tau C and DG Tau we see
highly-collimated bipolar outflows in the [Fe II] 1.644 micron line, surrounded
by a slower molecular bipolar outflow seen in the H_2 lines, in accordance with
the model advocated by Pyo et al. (2002).Comment: Invited paper presented at the 5th Stromlo Symposium. 9 pages, 7
figures. Accepted for publication in Astrophysics & Space Scienc
HAMAP in 2015: updates to the protein family classification and annotation system.
HAMAP (High-quality Automated and Manual Annotation of Proteins-available at http://hamap.expasy.org/) is a system for the automatic classification and annotation of protein sequences. HAMAP provides annotation of the same quality and detail as UniProtKB/Swiss-Prot, using manually curated profiles for protein sequence family classification and expert curated rules for functional annotation of family members. HAMAP data and tools are made available through our website and as part of the UniRule pipeline of UniProt, providing annotation for millions of unreviewed sequences of UniProtKB/TrEMBL. Here we report on the growth of HAMAP and updates to the HAMAP system since our last report in the NAR Database Issue of 2013. We continue to augment HAMAP with new family profiles and annotation rules as new protein families are characterized and annotated in UniProtKB/Swiss-Prot; the latest version of HAMAP (as of 3 September 2014) contains 1983 family classification profiles and 1998 annotation rules (up from 1780 and 1720). We demonstrate how the complex logic of HAMAP rules allows for precise annotation of individual functional variants within large homologous protein families. We also describe improvements to our web-based tool HAMAP-Scan which simplify the classification and annotation of sequences, and the incorporation of an improved sequence-profile search algorithm
A Coulomb gas approach to the anisotropic one-dimensional Kondo lattice model at arbitrary filling
We establish a mapping of a general spin-fermion system in one dimension into
a classical generalized Coulomb gas. This mapping allows a renormalization
group treatment of the anisotropic Kondo chain both at and away from
half-filling. We find that the phase diagram contains regions of paramagnetism,
partial and full ferromagnetic order. We also use the method to analyze the
phases of the Ising-Kondo chain.Comment: 19 pages, 9 figure
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