Publications by authors named "Benavides I"

We briefly review the history and development of recognizing nematode assemblages as indicators of environmental conditions. We highlight the effects of spatio-temporal successional changes in nematode assemblages on the auto-regeneration of ecosystem functions after disturbance. We expand on the need for herbivory components in the analysis of soil nematode assemblages in recognition of the important impact of plant parasitism on the resources and productivity of the soil system.

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Agroecological systems are potential solutions to the environmental challenges of intensive agriculture. Indigenous communities, such as the Kamëntšá Biyá and Kamëntšá Inga from the Sibundoy Valley (SV) in Colombia, have their own ancient agroecological systems called chagras. However, they are threatened by population growth and expansion of intensive agriculture.

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Climate change brings a range of challenges and opportunities to shrimp fisheries globally. The case of the Colombian Pacific Ocean (CPO) is notable due the crucial role of shrimps in the economy, supporting livelihoods for numerous families. However, the potential impacts of climate change on the distribution of shrimps loom large, making it urgent to scrutinize the prospective alterations that might unfurl across the CPO.

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We report development and preparation of synthetic polypeptide based, coacervate core polyelectrolyte complex micelles, PCMs, in aqueous media, which were characterized and evaluated for the encapsulation and in vitro release of a model single-stranded RNA, polyadenylic acid, poly(A). Cationic, α-helical polypeptides pegylated at their N-termini, PEG-b-5b and PEG-b-5c were designed to form coacervate core PCMs upon mixing with multivalent anions in aqueous media. Sodium tripolyphosphate (TPP) and poly(A) were used as model multivalent anions that allowed optimization of polypeptide composition and chain length for formation of stable, nanoscale PCMs.

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We report the preparation of a new water-soluble, nonionic homopolypeptide poly(l-homoserine) as well as poly(l-homoserine) block copolymers with controllable segment lengths. The conformational preferences of poly(l-homoserine) were also determined in both the solid state and in solution. Poly(l-homoserine) is soluble in water and adopts a disordered conformation that makes it a promising addition to the small class of nonionic, water-soluble homopolypeptides with potential for development for applications in biology.

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Via the design of a new, soluble poly(-alkyl-l-cysteine) precursor, a route was developed for the successful preparation of long-chain poly(dehydroalanine), , as well as the incorporation of dehydroalanine residues and segments into copolypeptides. Based on experimental and computational data, was found to adopt a previously unobserved "hybrid coil" structure, which combines the elements of 2-helical and 3-helical conformations. Analysis of the spectroscopic properties of revealed that it possesses a strong inherent blue fluorescence, which may be amenable for use in imaging applications.

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Flavobacterium psychrophilum is the causative agent of bacterial cold-water disease and rainbow trout syndrome in freshwater salmonid fish worldwide, generating injuries and high mortality rates. Despite several studies on this bacterium, the infection mechanism remains unknown due to limitations in the employed animal models. In this work, we propose using zebrafish (Danio rerio) as a model for studying bacterial pathogenicity.

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The positioning accuracy and precision of a head and neck immobilization device for radiation therapy of tumors in the canine skull was evaluated. Nineteen dogs with a spontaneous tumor of the head were enrolled including 12 with an intracranial mass and seven with an intranasal or maxillary tumor. Three hundred thirty-three pairs of orthogonal digital portal radiographs were analyzed to assess patient displacement in the cranial-caudal, lateral, and dorso-ventral directions.

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In this work we present results of the mapping on hypercube computers of some of the key steps involved in the procedure for 3D structural determination from transmission electron microscopy images. The goal is the introduction of parallel processing tools in the field of electron microscopy image processing. We show how the rich topology of the hypercube, combined with an efficient programming strategy, allows for order-of-magnitude increase in computational capacity for such time-consuming tasks as calculation of multidimensional FFT's, cross-correlation coefficients, fuzzy partitioning functionals and the filtered back-projection 3D reconstruction method.

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We studied intestinal absorption of vitamin E in rats with experimental renal failure (RF) and in sham-operated normal and pair-fed controls using in vivo perfusion and in vitro everted sacs. The in vivo absorption rates per unit of intestine length were significantly reduced in RF and pair-fed groups. Expression of data per unit of intestine weight gave normal values in the pair-fed but depressed values in the RF animals.

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Renal failure (RF) has been shown to alter intestinal transport of a number of nutrients. We studied jejunal absorption of pyridoxine (B6) in rats rendered azotemic by subtotal nephrectomy (RF group) and compared the results with those obtained in normal rats subjected to sham operation (controls) and animals pair-fed (PF) with their RF counterparts. In vivo recirculating perfusion and in vitro everted sac techniques were employed.

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Human cord blood (CB) lymphocytes were studied with several markers for T- and B-cells and the results compared with those of adult peripheral blood (PB) samples. The proportion of E-rosettes was significantly lower in CB (mean 24.7+/-13.

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The blast cells of 19 patients with Ph1-positive chronic granulocytic leukaemia (CGL) in blast crisis (BC) were studied by means of several techniques: morphology, cytochemistry, ultrastructure, surface markers and the enzyme terminal transferase. Cells of BC were, in most case, extremely undifferentiated by morphology and cytochemistry. Our data showed that in 80% of cases the cells in BC were myeloid and in 20% they were "lymphoblastic".

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