249 research outputs found

    Censo de focos de "Heterobasidion annosum" (Fr.) Bref. en ecosistemas de pinsapo

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    Se exponen los resultados de un censo de focos de podredumbre radical causada por Heterobasidion annosum (Fr.) Bref. en ecosistemas de Abies pinsapo Boiss. en las tres áreas de distribución natural de la especie en la Península Ibérica: los pinsapares de Sierra de las Nieves (Málaga), Sierra de Grazalema (Cádiz) y Los Reales de Sierra Bermeja (Málaga). La búsqueda del patógeno se dirigió a la observación de los sistemas radicales de los pies derribados visibles en el monte, para posterior delimitación de las zonas afectadas y cumplimentación de una ficha de campo específica para la descripción y caracterización de la enfermedad. El patógeno fue detectado en la totalidad de las áreas muestreadas, en un total de 81 centros de infección o focos, contabilizándose, adicionalmente, 11 zonas de elevada mortandad de pinsapo (áreas de posible infección), donde no pudo comprobarse la presencia del patógeno, si bien ésta se consideró posible. El Parque Natural Sierra de las Nieves fue el más afectado, con un 88.9% de los focos detectados. En Sierra de Grazalema la incidencia fue considerablemente inferior, si bien las características del pinsapar y las particularidades de la enfermedad en la zona hicieron temer de un riesgo generalizado de infección. Finalmente, Los Reales fue la zona menos afectada, con tan sólo un foco con causa atribuible a H. annosum.We expose the results of an inventory of gaps of trees of Abies pinsapo with root decay caused by Heterobasidion annosum. The sampling was developed in ecosystems with Abies pinsapo Boiss., in the species natural areas of the Iberian Peninsula: Sierra de las Nieves (Málaga, Spain), Sierra de Grazalema (Cádiz, Spain) and Los Reales de Sierra Bermeja (Málaga, Spain). The pathogen research was restricted to the observation of the radical systems in windthrown trees, identification in roots and further delimitation of the affected surface. The pathogen was identified in 81 infection centers, aditionally accounting 11 areas of high mortality oí Abies pinsapo trees {areas of possible infection), where the presence of H. annosum was not certain but considered possible. Sierra de las Nieves Natural Park was the most affected area, reaching the 88.9% of the total amount of infections centers. Sierra de Grazalema showed a lower incidence, although the stand features and disease particularities in this Park make us suspect a general and high risk of infection all over the A. pinsapo forest. Finally, Los Reales was the least affected zone, with only one infection center with root decay caused by H. annosum

    What do rates of deposition of dental cementum tell us? Functional and evolutionary hypotheses in red deer.

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    Cementum is a bone connective tissue that provides a flexible attachment for the tooth to the alveolar bone in many mammalian species. It does not undergo continuous remodelling, unlike non-dental bone, which combined with its growth pattern of seasonal layering makes this tissue uniquely suitable as a proxy for tracking changes in body repair investment throughout an animal´s life. We tested functional and sexual selection hypotheses on the rate of cementum deposition related to the highly polygynous mating strategy of red deer. We used a sample of 156 first lower molars from wild Scottish red deer of known age between 1 and 17 years old, approximately balanced by sex and age class. Cementum deposition on the inter-radicular pad increased with age at a constant average rate of 0.26 mm per year, with no significant differences between sexes. Cementum deposition was independent of (i) tooth wear, other than that associated with age, and (ii) enamel and dentine micro-hardness. The results partially supported the hypothesis that the main function of cementum is the repositioning of the tooth to maintain opposing teeth in occlusion. However, teeth that had more wear or males´ teeth that had faster rates of tooth wear than those of females did not present the expected higher rates of cementum deposition

    Proanthocyanidin characterization and bioactivity of extracts from different parts of Uncaria tomentosa L. (cat’s claw)

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    This article belongs to the Special Issue Dietary Antioxidants and Health Promotion.-- et al.Apart from alkaloids, bioactive properties of Uncaria tomentosa L. have been attributed to its phenolic constituents. Although there are some reports concerning low-molecular-weight polyphenols in U. tomentosa, its polymeric phenolic composition has been scarcely studied. In this study, phenolic-rich extracts from leaves, stems, bark and wood (n = 14) of Uncaria tomentosa plants from several regions of Costa Rica were obtained and analysed in respect to their proanthocyanidin profile determined by a quadrupole-time-of-flight analyser (ESI-QTOF MS). Main structural characteristics found for U. tomentosa proanthocyanidins were: (a) monomer composition, including pure procyanidins (only composed of (epi)catechin units) and propelargonidins (only composed of (epi)afzelechin units) as well as mixed proanthocyanidins; and (b) degree of polymerization, from 3 up to 11 units. In addition, U. tomentosa phenolic extracts were found to exhibit reasonable antioxidant capacity (ORAC (Oxygen Radical Absorbance Capacity) values between 1.5 and 18.8 mmol TE/g) and antimicrobial activity against potential respiratory pathogens (minimum IC of 133 µg/mL). There were also found to be particularly cytotoxic to gastric adenocarcinoma AGS and colon adenocarcinoma SW620 cell lines. The results state the particularities of U. tomentosa proanthocyanidins and suggest the potential value of these extracts with prospective use as functional ingredients.This project was partially funded by grant from the Spanish International Development Cooperation Agency (AECID) (Ref. A/023397/09 and A/030037/10) and a joint grant from the Costa Rica-USA Foundation (CRUSA) and the Spanish Scientific Research Council (CSIC) (Ref. CR0024). Authors also thank financial support from the Comunidad de Madrid (Spain) and European funding from FEDER program (projects AVANSECAL-CM S2013/ABI-3028 and ALIBIRD-CM S2013/ABI-2728) and from the University of Costa Rica. Special thanks are due to Eng. Juan Jose Cordero from Costa Rican National Production Council (CNP).Peer Reviewe

    Suicide attempts in mexican teenagers: a cultural consensus theory perspective

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    El suicidio es un problema de salud pública mundial y los adolescentes son los que presentan con mayor frecuencia esta problemática. El estudio realizado identifica la estructura semántica del dominio cultural, el promedio de conocimiento y el grado de consenso cultural que sobre el suicidio tienen adolescentes con tentativa suicida. El trabajo es un estudio cualitativo mediante la técnica de listas libres. Participaron 29 adolescentes (13 a 18 años). Las listas libres fueron sobre: las causas; los signos y los síntomas; lo que siente, piensa y hace un adolescente antes de cometer suicidio y las estrategias de prevención de éste. Los resultados muestran para cada pregunta un único modelo semántico en el dominio cultural. En lo estructural se identifican los problemas familiares como la causa del intento suicida; la depresión y la tristeza son síntomas previos al intento suicida. La tristeza y la soledad, salir del problema y suicidarse es lo que considera que siente, piensa y hace un adolescente previo al intento de suicidio. Como estrategias de prevención, se identifican le ponga más atención y hablar con él. Los resultados ponderan la importancia de la familia para los programas de prevención de las conductas suicidas en adolescentes. The suicide is a problem of public world health and the adolescents are those who present with more frequency this problem. Nevertheless, the studies of the suicide phenomenon from a cultural perspective are limited. Cultural research in suicidology is important to develop the understanding of the meanings of suicidal behavior in different contexts. The cultural consensus theory would contribute to the cultural perspective of the knowledge of suicidal behaviors in terms of its internal elements and their functioning (emic) and this theory allows knowing if there exists a knowledge shared by a social group regarding an issue and allows to recognize its organization. The aim of this study was to identify the semantic structure of the cultural domain, as well as the average of knowledge and the degree of cultural consensus regarding suicide among adolescent suicide attempters. It was a qualitative study, using the free-listing technique, with a non-random sample made up of 29 adolescents between the ages of 13 and 18 years. The free lists were on: the causes; the signs and the symptoms; what he/she feels, thinks and does before attempting suicide and the strategies of suicide prevention at adolescence. The results showed for every question a single semantic model in the cultural domain suicide attempt. In such structure, the family problems were identified as the cause of suicidal attempt; the depression and the sadness were symptoms before suicidal attempt. The sadness, the loneliness and the anger were what an adolescent feels before the suicide attempt. Furthermore, to get out of the problem and to end his/her life were what an adolescent thinks before attempting suicide and to commit suicide was what an adolescent does before to suicide attempt. To pay more attention, to talk with the adolescent, to improve the communication with the parents and to attend a psychotherapy were identified as strategies for suicide prevention. The results highlight the importance of the family of suicide prevention programs for adolescents based on cultural knowledge.ITESO, A.C.Universidad de GuadalajaraInstituto Mexicano del Seguro SocialPsicólogos Especializados Jalisc

    Effects of amphetamine on development of oral candidiasis in rats

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    [Abstract] Experiments were conducted to evaluate the effects of amphetamine (0.4 mg/kg of body weight/day) on the development of oral candidiasis in Sprague-Dawley rats. Animals were submitted to surgical hyposalivation in order to facilitate the establishment and persistence of Candida albicans infection. Treatment with drugs (placebo or amphetamine) was initiated 7 days before C. albicans inoculation and lasted until the end of the experiments, day 15 postinoculation. Establishment of C. albicans infection was evaluated by swabbing the inoculated oral cavity with a sterile cotton applicator on days 2 and 15 after inoculation, followed by plating on YEPD (yeast extract-peptone-dextrose) agar. Tissue injury was determined by the quantification of the number and type (normal or abnormal) of papillae on the dorsal tongue per microscopic field. A semiquan- titative scale was devised to assess the degree of colonization of the epithelium by fungal hyphae. Our results show that amphetamine exacerbates C. albicans infection of the tongues of rats. Significant increases in Candida counts, the percentage of the tongue’s surface covered with clinical lesions, the percentage of abnormal papillae, and the colonization of the epithelium by fungal hyphae were found in amphetamine-treated rats compared to those found in the rats injected with a placebo. The last two parameters increased in rats treated with the placebo compared to the parameters of the untreated control rats

    Monolithic stirrer reactors for the sustainable production of dihydroxybenzenes over 3D printed Fe/γ-Al2O3 monoliths: kinetic modeling and CFD simulation

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    The aim of this work is to evaluate the performance of the stirring 3D Fe/Al2O3 monolithic reactor in batch operation applied to the liquid-phase hydroxylation of phenol by hydrogen peroxide (H2O2 ). An experimental and numerical investigation was carried out at the following operating conditions: CPHENOL,0 = 0.33 M, CH2O2,0 = 0.33 M, T = 75–95◦C, P = 1 atm, ω = 200–500 rpm and WCAT ~ 1.1 g. The kinetic model described the consumption of the H2O2 by a zero-order power-law equation, while the phenol hydroxylation and catechol and hydroquinone production by Eley–Rideal model; the rate determining step was the reaction between the adsorbed H2O2, phenol in solution with two active sites involved. The 3D CFD model, coupling the conservation of mass, momentum and species together with the reaction kinetic equations, was experimentally validated. It demonstrated a laminar flow characterized by the presence of an annular zone located inside and surrounding the monoliths (u = 40–80 mm s−1 ) and a central vortex with very low velocities (u = 3.5–8 mm s−1 ). The simulation study showed the increasing phenol selectivity to dihydroxybenzenes by the reaction temperature, while the initial H2O2 concentration mainly affects the phenol conversio

    Del contexto cultural al funcionamiento familiar. Conocimientos compartidos y relaciones familiares en adolescentes con intento de suicidio

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    El objetivo de este texto es identificar y comparar la estructura semántica del dominio cultural, el conocimiento promedio y el grado de consenso cultural sobre las causas del intento de suicidio, los síntomas previos y las estrategias de prevención del intento de suicidio, además evaluar el funcionamiento familiar entre adolescentes mexicanos con y sin intento de suicidio. Se presenta un estudio mixto metodológicamente que usa la técnica de listas libres y el inventario de recursos familiares en una muestra propositiva de 65 adolescentes (13 a 18 años) divididos en dos grupos: el grupo de adolescentes con tentativa suicida y un grupo control con adolescentes estudiantes sin antecedentes de conductas suicidas. Los problemas familiares fueron la principal causa del intento suicida, mientras que la depresión y la tristeza fueron síntomas previos a una tentativa suicida en ambos grupos. La ayuda psicológica y el desarrollo de habilidades de escucha en los padres fueron señaladas como las estrategias para la prevención del suicidio. Respecto del funcionamiento familiar, los adolescentes con tentativa suicida percibieron más conflictos familiares y menor comunicación y apoyo en sus familias en comparación con el grupo control. Los resultados sugieren un conocimiento compartido culturalmente sobre las causas, los síntomas y las estrategias de prevención del intento de suicidio en los adolescentes, el cual se confirma en la percepción del funcionamiento familiar. La familia, elemento central en la cultura mexicana, debe ser considerada en las estrategias de prevención del intento de suicidio en los adolescentes en México. AIM: The aim of the study was to identify and to compare the semantic structure of the cultural domain, the average knowledge and the degree of cultural consensus regarding knowledge of suicide attempts cause, symptoms and prevention strategies to suicide attempt and the family functioning among Mexican adolescents with and without previous suicide attempt. Method: It was a mixed study, using the free-listing technique and an inventory of family resources, with a non-random sample of 65 adolescents (13-18 years) divided in two groups. The suicide attempters group and the control group were high school students, without a history of suicide behaviors. Results: Family problems were identified as the most important cause of suicide attempts in both groups, while depression and sadness were identified as symptoms prior to the suicide attempt in both groups. Psychological aid and development of listening skills in the parents were the most frequent responses regarding prevention strategies to suicide attempt. Regarding family functioning teenage suicide attempters showed more family conflict, less family communication and support than teenage non suicide attempters. Conclusions: The results suggest a same cultural knowledge background regarding causes, symptoms prior and prevention strategies to suicide attempt in Mexican adolescents. Mexican culture centered in family relationships is important to be considered in design of prevention strategies to suicide attempt in adolescence in Mexico.ITESO, A.C

    In vitro gastrointestinal digestion of microencapsulated extracts of Flourensia cernua, F. microphylla, and F. retinophylla

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    Recently, some species of the genus Flourensia have been identified by their potential health effects (e.g. anti-inflammatory and apoptotic). Encapsulation of plant extracts is a process that can allow an adequate dosage administration, as well as to protect bioactive compounds and improve their controlled release in the gastrointestinal (GI) system. Therefore, the aims of this work were: to microencapsulate the ethanol extracts of F. cernua, F. microphylla, and F. retinophylla; and to evaluate the controlled release of the microencapsuled extracts in an in vitro GI system. Leaves of Flourensia spp. were collected in wild sites of Coahuila State, and the ethanol extracts were obtained by the Soxhlet method. The encapsulation was performed by the gelation technique, using alginate. The microcapsules formed were characterized in terms of total phenol content (Folin-Ciocalteu method), antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic) diammonium acid (ABTS), and the ferric reducing antioxidant power (FRAP) assays, scanning electron microscopy (SEM), and thermal analysis, and in vitro GI digestion. The microcapsules were found to have spherical-shape and a micro-scale dimension in the range of 2.168.8??m. Also, the built of microcapsules was confirmed by the appearance of an exothermic peak centered at 600?°C in the DSC analysis. F. microphylla noted for its strong antioxidant activity, even in its encapsulated form. In the gastric system the extracts of fresh microcapsules were released from 7.7% to 14.5%, while values of 26.5% to 53.3% were observed for those dried. For the intestinal system, the higher release was observed for dried microcapsules (59.9% to 78.4%) than for those fresh (26.3% to 30.2%). Thus, it was demonstrated that the alginate microcapsule protected the extracts until they were delivered to the target site in the GI model, and this effect was better with the dried microcapsules of Flourensia spp. This study would set the guide for the application of Flourensia spp. extracts in order to take advantage of their benefits to human health.Author G.N. Puente Romero thanks Mexican Science and Technology Council (CONACYT, Mexico) for MSc fellowship support. Authors would like to thank to María Guadalupe Moreno Esquivel, Edith E. Chaires Colunga, Olga L. Solís Hernández, and M. Leticia Rodríguez González of the Phytochemistry Laboratory from Universidad Autónoma Agraria Antonio Narro, for their support in the lab experiments.info:eu-repo/semantics/publishedVersio

    Understanding the active sites of boron nitride for CWPO: An experimental and computational approach

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    [EN] Hexagonal boron nitride (h-BN) has been explored as a catalyst for degrading persistent organic pollutants in wastewater by Catalytic Wet Peroxide Oxidation (CWPO). Herein, the superior activity of the h-BN on the phenol degradation (model pollutant) compared to other metal-free catalysts, such as carbon-based ones, and the lower selectivity to CO encourage the potential application of h-BN catalysts in CWPO processes. Through a combined density functional theory calculations, experimental reactions and catalyst characterization approach, a comprehensive study on the reaction mechanism has been conducted. According to this, only defected B atoms in the h-BN layer, protonated as B-(OH), decompose the hydrogen peroxide into highly reactive hydroxyl radicals. The radical species diffuse towards inner h-BN regions and react with the phenol adsorbed by π-π interaction on the h-BN surface. Oxidation by-products cause carbonaceous deposits and progressive deactivation of the h-BN catalyst that can be directly regenerated by burning off in air.The authors thank the financial support by the Community of Madrid and the Government of Spain through the projects: S2018/EMT- 4341 and RTI2018-095052-B-I00 (MCIU/AEI/FEDER, UE), respectively. The work done at the University of Sevilla was funded by Spanish Ministerio de Ciencia e Innovación and EU-FEDER, grant PID2019-106871 GB-I00, and the Junta de Andalucía-FEDER, grant: US-1381410. Also, G. Vega acknowledges the Community of Madrid for the Predoctoral contract PEJD-2018-PRE/AMB-9019, co-financed by the European Social Fund through the Youth Employment Operational Program and the Youth Employment Initiative (YEI) 2018. J. Carbajo thanks the financial support by the Government of Spain for a grant under the Juan de la Cierva_Incorporación programme (IJCI-2017- 32682). The authors would like to thank A. Pérez for performing the BET and TGA measurements
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