Repositorio institucional - Concytec
Not a member yet
3190 research outputs found
Sort by
Estructura y composición florística de un bosque ribereño en el distrito de Yarinacocha, Ucayali, Perú
No full textEl objetivo en este estudio fue determinar la estructura y composición florística de un bosque ribereño en el distrito de Yarinacocha, Ucayali, Perú, para ello, se utilizó la base gráfica de la zona, ubicado en el caserío 7 de junio, seguidamente, fue georreferenciado las cinco parcelas para ser censadas, en cada parcela fue registrado los datos: nombre común, fue medido el DAP (m), y altura total de todos los árboles en pie (m). Con los datos se analizaron la composición florística, estructura del bosque y los índices de importancia ecológica por especie y familias.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
NMR-based leaf metabolic profiling of V. planifolia and three endemic Vanilla species from the Peruvian Amazon
No full textThe fruit of Vanilla planifolia is broadly preferred by the agroindustry and gourmet markets due to its refined flavor and aroma. Peruvian Vanilla has been proposed as a possible source for genetic improvement of existing Vanilla cultivars, but, little has been done to facilitate comprehensive studies of these and other Vanilla. Here, a nuclear magnetic resonance (NMR) metabolomic platform was developed to profile for the first time the leaves – organ known to accumulate vanillin putative precursors – of V. planifolia and those of Peruvian V. pompona, V. palmarum, and V. ribeiroi, with the aim to determine metabolic differences among them. Analysis of the NMR spectra allowed the identification of thirty-six metabolites, twenty-five of which were quantified. One-way ANOVA and post-hoc Tukey test revealed that these metabolites changed significantly among species, whilst multivariate-analyses allowed the identification of malic and homocitric acids, together with two vanillin precursors, as relevant metabolic markers for species differentiation. © 2021 Elsevier LtdConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Knowledge and use of antibiotics among low-income small-scale farmers of Peru
No full textThe extensive use and misuse of antibiotics in the livestock sector is one of the main drivers of the emergence and spread of antimicrobial resistance. Although small-scale farms constitute most of the livestock production in low and middle-income countries, knowledge and use of antibiotics among these populations is sparse. We conducted 201 questionnaires to estimate the use and knowledge of antibiotics by small-scale farmers located in the coastal area of the Lima region of Peru. Our results show that farmers had a small number of livestock (e.g. average of 11 cows, 7 pigs and 19 chickens per farm) and 80 % earned less than minimum wage. More than half of farmers reported at least one episode of respiratory disease, diarrhea, mastitis, skin lesion or post-parturition infection in their animals during the previous year, and 40 % of these episodes were treated with antibiotics. Farmers reported using 14 different antibiotics, most commonly oxytetracycline (31 % of episodes treated with antibiotics), penicillin (21 %), gentamicin (19 %) and trimethoprim-sulfamethazine (18 %). The third-generation cephalosporin ceftiofur was occasionally used to treat mastitis. Most farmers relied on veterinarians to prescribe (95 % of respondents) and administer (59 %) antibiotics. Only half of farmers knew what micro-organisms can be treated with antibiotics and the degree of knowledge of antibiotics (based on a 5-question metric) was positively correlated with respondents’ educational level, monthly income, knowledge of the animal health authority, farm area, number of cows and knowledge of an antiparasitic drug. In contrast, knowledge of antibiotics was not correlated with respondents’ age, gender, main occupation, knowledge of a veterinarian or household size. Potential misuse of antibiotics was reported, including 21 % of framers reporting stopping the treatment when clinical signs disappear and infrequent use of antibiotics to treat parasites or animals not eating. Our study highlights poor knowledge and potential misuse of antibiotics among small-scale farmers in coastal Peru, but high reliance on veterinarians for prescription and administration. Strengthening farmers' relationships with veterinarians and improving the diagnostic capacity of the veterinary sector could result in more judicious antibiotic use on these farms. © 2021 The AuthorsConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Modification of NaCl structure as a sodium reduction strategy in meat products: An overview
No full textSodium chloride (NaCl) is an indispensable ingredient in meat products, but the consumption of high doses of sodium contained in their formulations may bring about negative health implications. The replacement of NaCl by other salts in meat products has been a technological challenge. Accordingly, this review highlights the importance of NaCl over other sodium and non‑sodium salts in the saltiness perception and proposes the use of reduced-size and shapes of NaCl to maximize saltiness perception, while using less NaCl dosages in meat products. However, the effect of matrix components (water, proteins and fats) on the final salty taste is of special consideration. To counteract the effect of the matrix components, two main routes of incorporation of different NaCl types in meat products are discussed: encapsulation and protection of NaCl by the hydrophobic component of the meat product. Given the limited number of publications using this potential strategy, more studies on the application of these technological strategies are required. © 2020 Elsevier LtdFondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Photoelectrocatalytic degradation of 2,4-dichlorophenol in a TiO2 nanotube-coated disc flow reactor
No full textPhotoelectrocatalytic (PEC) water treatment is a promising technology for organic pollution abatement. Much of the prior research focused on material discovery and optimization. However, challenges exist in scaling-up PEC processes and are associated with designing reactors with effective light irradiation on electrode surfaces and, simultaneously, efficient electrode configurations. We design and demonstrate key reactor design principles, which influence reaction mechanisms, for a reactor using a TiO2 nanotube-coated disc flow reactor. Degradation of organochlorinated 2,4-dichlorophenol was studied as representative carcinogenic micropollutant. The synergistic photoelectrocatalytic process showed 5-fold faster degradation kinetics than solely electrocatalytic treatment or a greater than 2-fold enhancement over photocatalysis alone. Applicability of photoelectrocatalytic treatment was demonstrated over a wide range of micropollutant concentrations with almost complete abatement even at concentrations up to 25 mg L?1 of 2,4-dichlorophenol. Mechanistically, the increase in applied current density efficiency for degradation of 2,4-dichlorophenol was due to stabilization of charge carriers and higher oxidants production rates in the PEC system. Carboxylic acids were identified as the main by-products formed from cleavage of the phenolic ring moieties in 2,4-dichlorophenol. However, very importantly we achieved dehalogenation photoelectrocatalysis with evidence of chlorine heteroatoms released as innocuous chloride anions. Overall, this research demonstrates the importance of PEC reactor design and how properly orientated TiO2 nanotube-coated disc flow reactors leverage both novel material designs and reactor architectures to achieve pollutant degradation. © 2020 Elsevier LtdConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Bioprospection of Native Antagonistic Rhizobacteria From the Peruvian Coastal Ecosystems Associated with Phaseolus vulgaris
No full textPhaseolus vulgaris is originally from the American continent. It is renowned as one of the preferred legume choice in the Peruvian market, due to its high content of nutrients. The Peruvian coast valleys are key-production areas for local varieties of the common bean crops. Soil-borne plant pathogens, however, favored by soil and environmental conditions, may reduce crop production. The aim of this study was to conduct a bio prospection of the antagonistic native bacteria of the north, south and central part of the coastal areas related to the common bean. A collection of 26 strains isolated from the rhizosphere of common bean plants showed high potential to control the growth of Sclerotinia, Fusarium and Rhizoctonia due to the production of both volatile and non-volatile organic compounds. Most of the strains were able to suppress fungal growth due to the presence of non-volatile organic compounds, such as hydrolytic enzymes, siderophores and antifungal lipopeptide production. Bacillus IcBac2.1 strain showed a remarkable ability to halt the majority of phytopathogens producing antifungal lipopeptides. The crude lipopeptides were soluble in polar solvents and remained stable at high temperatures and low pH. Strains were also able to inhibit fungal growth through volatile organic compounds. Alcaligenes TvPs2.4 and Pseudomonas TvPs1.6 showed the highest inhibition strength against the tested phytopathogens. Each strain produced 21 volatile organic compounds detected by SPME/GC–MS analysis. The compounds with the highest concentration were dimethyl disulfide and d-limonene. The 16S rRNA gene sequence confirmed that the strains were closely related to Bacillus, Paenibacillus, Achromobacter, Pseudomonas, Serratia and Alcaligenes. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Silicon interface passivation studied by modulated surface photovoltage spectroscopy
No full textWe demonstrate that the modulated surface photovoltage spectroscopy (modulated SPS) technique can be applied to investigate interface states in the bandgap, i.e. interface passivation, of crystalline silicon coated with a downshift layer such as hydrogenated aluminum nitride with embedded terbium ions by suppressing straylight with a cut-off filter. Different hydrogen contents influence the surface photovoltage spectra at photon energies below the bandgap of crystalline silicon. Modulated SPS reveals that at higher hydrogen content there is a lower signal and, thus, a lower density of surface defect states. Our experiments show that modulated SPS can become a powerful tool for characterizing defect states at interfaces which cannot be easily studied by other methods. © 2021 Published under licence by IOP Publishing Ltd.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Market Chickens as a Source of Antibiotic-Resistant Escherichia coli in a Peri-Urban Community in Lima, Peru
No full textThe widespread and poorly regulated use of antibiotics in animal production in low- and middle-income countries (LMICs) is increasingly associated with the emergence and dissemination of antibiotic resistance genes (ARGs) in retail animal products. Here, we compared Escherichia coli from chickens and humans with varying levels of exposure to chicken meat in a low-income community in the southern outskirts of Lima, Peru. We hypothesize that current practices in local poultry production result in highly resistant commensal bacteria in chickens that can potentially colonize the human gut. E. coli was isolated from cloacal swabs of non-organic (n = 41) and organic chickens (n = 20), as well as from stools of market chicken vendors (n = 23), non-vendors (n = 48), and babies (n = 60). 315 E. coli isolates from humans (n = 150) and chickens (n = 165) were identified, with chickens showing higher rates of multidrug-resistant and extended-spectrum beta-lactamase phenotypes. Non-organic chicken isolates were more resistant to most antibiotics tested than human isolates, while organic chicken isolates were susceptible to most antibiotics. Whole-genome sequencing of 118 isolates identified shared phylogroups between human and animal populations and 604 ARG hits across genomes. Resistance to florfenicol (an antibiotic commonly used as a growth promoter in poultry but not approved for human use) was higher in chicken vendors compared to other human groups. Isolates from non-organic chickens contained genes conferring resistance to clinically relevant antibiotics, including mcr-1 for colistin resistance, blaCTX-M ESBLs, and blaKPC-3 carbapenemase. Our findings suggest that E. coli strains from market chickens are a potential source of ARGs that can be transmitted to human commensals. © Copyright © 2021 Murray, Salvatierra, Dávila-Barclay, Ayzanoa, Castillo-Vilcahuaman, Huang, Pajuelo, Lescano, Cabrera, Calderón, Berg, Gilman and Tsukayama.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Data mining of DNA sequences submitted by Peruvian institutions to public genetic databases [Minería de datos de secuencias de DNA enviadas a bases de datos genéticas públicas por instituciones peruanas]
No full textGenetic diversity is an important component of biodiversity, and it is crucial for current efforts to protect and sustainably manage several organisms and habitats. As far as we know, there is only one work describing Peruvian genetic information stored in public databases. We aimed to update this previous work searching in four public databases that stored digital sequence information: Nucleotide, BioProject, PATRIC, BOLD. With this information, we comment on the contribution of Peruvian institutions during recent years. In Nucleotide, the largest database, Bacteria are the most sequenced organisms by Peruvian institutions (70.60%), pathogenic bacteria such as Pasteurella multocida, Neisseria meningitidis, and Vibrio parahaemolyticus were the most abundant. We found no sequence records from the Archaea domain. In BioProject, the most common sequence belongs to Salmonella enterica subsp. enterica serovar Infantis. In PATRIC, a database of pathogenic agents, Mycobacterium tuberculosis and Yersinia pestis had the highest number of entries. Finally, in BOLD, an exclusively Eukaryotic database, Chordata (Aves and Actinopterygii), Angiospermae, and Arthropoda (Insecta, and Arachnida) were the most frequent records. Our results would indicate research preferences of Peruvian institutions, focusing on infectious diseases and some Eukaryotic phyla. Although there has been a significant increase of DNA information submitted by Peruvian institutions since the last report, the genetic diversity reflected in these databases remains inconsistent with the diversity in the country. More efforts must be made to obtain genetic information from more underestimated taxonomic groups and to promote more genetic research in regional Peruvian institutions. © Los autores.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Functionalization of an alginate-based material by oxidation and reductive amination
No full textThis research focused on the synthesis of a functional alginate-based material via chemical modification processes with two steps: oxidation and reductive amination. In previous alginate functionalization with a target molecule such as cysteine, the starting material was purified and characterized by UV-Vis,1 H-NMR and HSQC. Additionally, the application of FT-IR techniques during each step of alginate functionalization was very useful, since new bands and spiked signals around the pyranose ring (1200–1000 cm−1) and anomeric region (1000–750 cm−1) region were identified by a second derivative. Additionally, the presence of C1-H1 of β-D-mannuronic acid residue as well as C1-H1 of α-L-guluronic acid residue was observed in the FT-IR spectra, including a band at 858 cm−1 with characteristics of the N-H moiety from cysteine. The possibility of attaching cysteine molecules to an alginate backbone by oxidation and post-reductive amination processes was confirmed through13 C-NMR in solid state; a new peak at 99.2 ppm was observed, owing to a hemiacetal group formed in oxidation alginate. Further, the peak at 31.2 ppm demonstrates the presence of carbon-CH2-SH in functionalized alginate—clear evidence that cysteine was successfully attached to the alginate backbone, with 185 µmol of thiol groups per gram polymer estimated in alginate-based material by UV-Visible. Finally, it was observed that guluronic acid residue of alginate are preferentially more affected than mannuronic acid residue in the functionalization. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy