209 research outputs found
ProspecciĂÂłn de mercado de hortalizas bajo producciĂÂłn integrada en cuatro ciudades de la Octava RegiĂÂłn de Chile
Published by AsociaciĂÂłn de Economistas Agrarios de Chilewillingness to purchase, vegetables, integrated production, Agribusiness, Consumer/Household Economics, Marketing,
Search for massive protostellar candidates in the southern hemisphere: I. Association with dense gas
(Abridged) We have observed CS and C17O lines, and 1.2 mm cont. emission
towards a sample of 130 high-mass protostellar candidates with DEC<-30 deg.
This is the first step of the southern extension of a project started more than
a decade ago aimed at the identification of massive protostellar candidates. We
selected from the IRAS PSC 429 sources which potentially are compact molecular
clouds. The sample is divided into two groups: the 298 sources with
[25-12]>0.57 and [60-12]>1.30 we call 'High' sources, the remaining 131 we call
'Low' sources. In this paper, we check the association with dense gas and dust
in 130 'Low' sources. We find a detection rate of ca. 85% in CS, demonstrating
a tight association with dense molecular clumps. Among the sources detected in
CS, ca. 76% have also been detected in C17O and ca. 93% in the 1.2 mm cont.
Mm-cont. maps show the presence of clumps with diameters 0.2-2 pc and masses
from a few Msun to 10^5 Msun; H2 volume densities lie between ca. 10^{4.5} and
10^{5.5} cm^{-3}. The L(bol) are 10^3-10^6 Lsun, consistent with embedded
high-mass objects. Based on our results and those found in the literature for
other samples, we conclude that our sources are massive objects probably in a
stage prior to the formation of an HII region. We propose a scenario in which
'High' and 'Low' sources are both made of a massive clump hosting a high-mass
protostellar candidate and a nearby stellar cluster. The difference might be
due to the fact that the IRAS 12mu flux, the best discriminant between the two
groups, is dominated by the emission from the cluster in 'Lows' and from the
massive protostellar object in 'Highs'.Comment: Accepted for publication in Astron. & Astroph.; 34 pages (incl. 14
figures and 8 tables
Biometric system verification close to "real world" conditions
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-04391-8_31Proceedings of Joint COST 2101 and 2102 International Conference, BioID_MultiComm 2009, Madrid, Spain.In this paper we present an autonomous biometric device developed in the framework of a national project. This system is able to capture speech, hand-geometry, online signature and face, and can open a door when the user is positively verified. Nevertheless the main purpose is to acquire a database without supervision (normal databases are collected in the presence of a supervisor that tells you what to do in front of the device, which is an unrealistic situation). This system will permit us to explain the main differences between what we call "real conditions" as opposed to "laboratory conditions".This work has been supported by FEDER and MEC, TEC2006-13141-C03/TCM, and COST-2102
Evaluation of the canine epididymal sperm morphology with two different staining methods, one fixative solution and motile sperm organelle morphology examination (msome)
The HST Survey of BL Lacertae Objects: Morphological Properties of Low redshift Host Galaxies
We report on the optical properties of a sample of 30 BL Lac host galaxies in
the redshift range , as derived from HST observations. All galaxies
are fully resolved in the WFPC2 (F702W filter) images, allowing a quantitative
analysis in two dimensions. Most and possibly all these galaxies have
characteristics very similar to those of ``normal'' giant ellipticals. The
luminosity, ellipticity, isophote twisting and amount of disky or boxy
isophotes are consistent with those found in non-active ellipticals and in
radio galaxies. In all cases the BL Lac nucleus is well centered in the main
body of its host galaxy, a result that argues strongly against the microlensing
hypothesis for any significant fraction of the population. A search for faint
sub-structures in the host galaxies has not revealed notable signatures of
tidal distortions or sub-components (faint disks, bars, X features, etc.), and
with only one exception, there are no prominent dusty features in the central
regions. Instead, the BL Lac host galaxies are smooth and unperturbed,
suggesting that strong external gravitational interactions are not important to
ongoing activity. A careful examination of the environment around the nucleus,
however, shows a high incidence of close companion objects, whose nature
remains unclear pending spectroscopic observations.Comment: 16 pages, 8 figures. Ap.J accepte
Promising 2,6,9-Trisubstituted Purine Derivatives for Anticancer Compounds: Synthesis, 3D-QSAR, and Preliminary Biological Assays
We designed, synthesized, and evaluated novel 2,6,9-trisubstituted purine derivatives for their prospective role as antitumor compounds. Using simple and efficient methodologies, 31 compounds were obtained. We tested these compounds in vitro to draw conclusions about their cell toxicity on seven cancer cells lines and one non-neoplastic cell line. Structural requirements for antitumor activity on two different cancer cell lines were analyzed with SAR and 3D-QSAR. The 3D-QSAR models showed that steric properties could better explain the cytotoxicity of compounds than electronic properties (70% and 30% of contribution, respectively). From this analysis, we concluded that an arylpiperazinyl system connected at position 6 of the purine ring is beneficial for cytotoxic activity, while the use of bulky systems at position C-2 of the purine is not favorable. Compound 7h was found to be an effective potential agent when compared with a currently marketed drug, cisplatin, in four out of the seven cancer cell lines tested. Compound 7h showed the highest potency, unprecedented selectivity, and complied with all the Lipinski rules. Finally, it was demonstrated that 7h induced apoptosis and caused cell cycle arrest at the S-phase on HL-60 cells. Our study suggests that substitution in the purine core by arylpiperidine moiety is essential to obtain derivatives with potential anticancer activityFinancial support was received from FONDECYT (Research Grant N⊠1161816) and FONDEQUIP
program CONICYT EQM 160042, Czech Science Foundation (19-09086S) and Palacky University
(IGA_PrF_2019_013) and Xunta de Galicia (ED431C 2018/21) and European Regional Development Fund (Project ENOCH, N⊠CZ.02.1.01/0.0/0.0/16_019/0000868)S
Bedbugs evolved before their bat hosts and did not co-speciate with ancient humans
All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites [1, 2]. In general, blood sucking (hematophagy) is thought to have evolved in generalist feeders adventitiously taking blood meals [3, 4], but those cimicid taxa currently considered ancestral are putative host specialists [1, 5]. Bats are believed to be the ancestral hosts of cimicids [1], but a cimicid fossil [6] predates the oldest known bat fossil [7] by >30 million years (Ma). The bedbugs that parasitize humans [1, 8] are host generalists, so their evolution from specialist ancestors is incompatible with the "resource efficiency" hypothesis and only partially consistent with the "oscillation" hypothesis [9-16]. Because quantifying host shift frequencies of hematophagous specialists and generalists may help to predict host associations when vertebrate ranges expand by climate change [17], livestock, and pet trade in general and because of the previously proposed role of human pre-history in parasite speciation [18-20], we constructed a fossil-dated, molecular phylogeny of the Cimicidae. This phylogeny places ancestral Cimicidae to 115 mya as hematophagous specialists with lineages that later frequently populated bat and bird lineages. We also found that the clades, including the two major current urban pests, Cimex lectularius and C. hemipterus, separated 47 mya, rejecting the notion that the evolutionary trajectories of Homo caused their divergence [18-21]
Benznidazole biotransformation and multiple targets in <i>Trypanosoma</i> cruzi revealed by metabolomics
<b>Background</b><p></p>
The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.<p></p>
<b>Methodology/Principal findings</b><p></p>
Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, Îł-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.<p></p>
<b>Conclusions/significance</b><p></p>
Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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