Dung removal increases under higher dung beetle functional diversity regardless of grazing intensification.

Dung removal by macrofauna such as dung beetles is an important process for nutrient cycling in pasturelands. Intensification of farming practices generally reduces species and functional diversity of terrestrial invertebrates, which may negatively affect ecosystem services. Here, we investigate the effects of cattle-grazing intensification on dung removal by dung beetles in field experiments replicated in 38 pastures around the world. Within each study site, we measured dung removal in pastures managed with low- and high-intensity regimes to assess between-regime differences in dung beetle diversity and dung removal, whilst also considering climate and regional variations. The impacts of intensification were heterogeneous, either diminishing or increasing dung beetle species richness, functional diversity, and dung removal rates. The effects of beetle diversity on dung removal were more variable across sites than within sites. Dung removal increased with species richness across sites, while functional diversity consistently enhanced dung removal within sites, independently of cattle grazing intensity or climate. Our findings indicate that, despite intensified cattle stocking rates, ecosystem services related to decomposition and nutrient cycling can be maintained when a functionally diverse dung beetle community inhabits the human-modified landscape.

Aesthetical perception of dental fluorosis in a Colombian low income community / Percepção estética da fluorose dentária em uma comunidade colombiana de baixa renda / Percepción estética de la fluorosis dental en una comunidad colombiana de bajos ingresos

Abstract Introduction and objective: The Dental Fluorosis (DF) is a development defect of enamel resulting from overexposure to fluoride and can aesthetically compromise the patient. This study aims to investigate the relationship between aesthetic perception and dental fluorosis (DF) in a low-income community with high DF prevalence. Materials and methods: A cross-sectional study was conducted with 171 Colombian schoolchildren aged 8 to 12 years living in low socioeconomic community (El Cedro, district of Ayapel, Córdoba, Colombia). After receiving authorization, the students were examined for DMFT and dmft indexes (WHO criteria), and for DF (TF index). The aesthetic perceptions were verified by the Child Perceptions Questionnaire About Tooth Appearance (CQATA). Data analysis was carried out using descriptive statistics, the chi-square test, the Student´s t-test, the one-way ANOVA test, and linear regression at a significance level of p ≤ 0.05. Results: The prevalence of DF in this sample was 84.8% (n=145). Only the presence of caries (DMFT/ deft≠ 0) had a significant impact on aesthetic perceptions. A significantly lower rate was found in girls for the report of pleasant color domain. The number of teeth affected by DF had a significant positive correlation with mean overall perception of dental health. Conclusion: The presence of mild DF in children with low socioeconomic status, from a population with a high prevalence of the condition, did not seem to have an impact on the report of pleasant color of teeth domain.

Resumo Introdução e Objetivo: A fluorose dentária (FD) é um defeito de desenvolvimento do esmalte decorrente da sobre-exposição ao flúor e pode comprometer esteticamente o paciente. O presente estudo se propõe a investigar a relação entre percepção estética e fluorose dentária em uma comunidade de baixa renda com alta prevalência de FD. Materiais e métodos: Foi realizado um estudo transversal com 171 escolares colombianos de 8 a 12 anos de idade, moradores de uma comunidade de baixa renda (El Cedro, distrito de Ayapel, Córdoba, Colômbia). Após receber autorização, os estudantes foram examinados para os índices CPOD e ceod (OMS) e para o FD (TF index). As percepções estéticas foram verificadas pelo "Child Perception Questionaire about Teeth Appearence" (CQATA). A análise dos dados foi realizada por meio de estatística descritiva, teste do qui-quadrado, teste t de Student, teste ANOVA one-way e regressão linear em nível de significância de p ≤ 0,05. Resultados: A prevalência de FD nesta amostra foi de 84,8% (n = 145). Apenas a presença de cáries (CPOD/cpod≠0) teve um impacto significativo nas percepções estéticas. Uma taxa significativamente menor foi encontrada em meninas para o relato de domínio de cor agradável. O número de dentes afetados pela FD teve correlação positiva significativa com a percepção geral da saúde bucal. Conclusão: A presença de FD leve em crianças com baixo nível socioeconômico, de uma população com alta prevalência da doença, não parece ter impacto na satisfação com a coloração dos dentes.

Resumen Introducción y objetivo: La fluorosis dental (FD) es un defecto en el desarrollo del esmalte como resultado de la sobreexposición al fluoruro y puede comprometer estéticamente al paciente. Este estudio tiene como objetivo investigar la relación entre la percepción estética y la fluorosis dental en una comunidad de bajos ingresos económicos y con alta prevalencia de FD. Materiales y métodos: Se realizó un estudio transversal con 171 escolares de 8 a 12 años que viven en una comunidad socioeconómica baja (El Cedro, distrito de Ayapel, Córdoba, Colombia). Los estudiantes fueron examinados para caries dentaria (índices DMFT y dmft (criterios de la OMS) y para el fluorosis dentaria (índice TF). La percepción estética se verifico con el cuestionario sobre percepciones de los niños sobre la apariencia de los dientes (CQATA). El análisis de los datos se realizó mediante estadísticas descriptivas y las pruebas de chi cuadrado, t de Student, ANOVA de una vía y la regresión lineal (p ≤ 0.05). Resultados: La prevalencia de FD fue de 84.8% (n = 145). Solo la presencia de caries (DMFT/deft ≠ 0) tuvo un impacto significativo en las percepciones estéticas. Se encontró una tasa significativamente más baja en las niñas para el informe acerca de color agradable. La cantidad de dientes afectados por FD tuvo una correlación positiva significativa con la percepción general de la salud dental. Conclusión: La presencia de FD leve en niños con bajo nivel socioeconómico, en una población con una alta prevalencia de este defecto de esmalte, no pareció tener tuvo un impacto en la aceptción aceptar la apariencia del color de los dientes.

Greater caries-free survival of first permanent molars: Findings from a 7-year follow-up evaluation of a community-based oral health preventive program.

BACKGROUND: The occlusal surface of the first permanent molar is the most frequently affected site by dental caries. AIM: To assess the caries-free survival of first permanent molars in children participating in a community-based oral health preventive program. DESIGN: This was a retrospective study conducted on 426 children under 12 years of age, beneficiaries of a preventive program from 2009 to 2015, in El Cedro, Colombia. The program offered oral health care education, supervised brushing and mouth washing, and application of topical fluoride. By using parametric survival models for interval-censored data, primary and secondary caries-free survival of any first permanent molar was estimated and analyzed. RESULTS: Before program implementation, dental caries lesions presented at an average age, adjusted by age of eruption, of 8.3 years for primary caries lesion and 9.3 years for secondary caries lesion. After 7 years of the program, the estimated average age for presenting primary dental caries lesion was delayed by 4.6 years and by 5.3 years for secondary caries. CONCLUSION: The implementation of the oral health program led to improved caries-free survival of first permanent molars.

Horizontal seed dispersal by dung beetles reduced seed and seedling clumping, but did not increase short-term seedling establishment.

Dung beetles are secondary seed dispersers, incidentally moving many of the seeds defecated by mammals vertically (seed burial) and/or horizontally as they process and relocate dung. Although several studies have quantified this ecological function of dung beetles, very few have followed seed fate until seedling establishment, and most of these have focused on the effects of seed burial. We know very little about the effects of horizontal seed movement by dung beetles, though it is generally assumed that it will affect plant recruitment positively through diminishing seed clumping. The objective of our study was to assess the effects of dung beetle activity on the spatial distribution of seeds and seedlings, and on the probability of seedling establishment. In a tropical rainforest in Mexico we carried out two complementary field experiments for each of two tree species (Bursera simaruba and Poulsenia armata), using seeds experimentally imbedded in pig dung and recording their fate and spatial location over time. For both species, dung beetle activity reduced the spatial clumping of seeds and seedlings; however, it did not increase the probability of seedling establishment. We discuss the context- and species-specificity of the combined effects of horizontal and vertical dispersal of seeds by dung beetles, and the need to quantify long-term seedling fates to more accurately determine the effects of seed movement by dung beetles on plant recruitment.

Clinical aspects of dental fluorosis according to histological features: a Thylstrup Fejerskov Index review / Aspectos clínicos da fluorose dentária de acordo com as características histológicas: revisão do índice Thylstrup Fejerskov / Aspectos clínicos de la fluorosis dental de acuerdo con las características histológicas: una revisión del índice de Thylstrup Fejerskov

Abstract Dental fluorosis is a developmental defect of enamel caused by chronic and excessive fluoride intake resulting in a hypomineralized enamel with increased porosity. It is clinically identified as spots ranging from mild white lines to opaque spots covering all or part of the enamel surface and breakdown after teeth eruption. However, the clinical definition of the fluorosis degree in teeth is not an easy task, having been presented many indices that generally qualify the severity degree with variations in the details. As the choice of treatment is closely linked to the defect severity, the purpose of this article is to present the clinical aspects of dental fluorosis represented through the Thylstrup-Fejerskov Index. The severity scores are presented according to histological features and the differences between them will be discussed in order to enable the dentist to correctly diagnose and choose the most appropriate treatment for the patient with DF.

Resumo A fluorose dental (FD) é um defeito de desenvolvimento do esmalte causado pela ingestão crônica e excessiva de flúor, resultando em um esmalte hipomineralizado com maior porosidade. Clinicamente é identificada como manchas que vão desde delicadas linhas brancas até manchas opacas que cobrem parte ou toda a superfície do esmalte podendo sofrer pigmentações ou fraturas após a irrupção. No entanto, a definição clínica do grau de comprometimento dos dentes não é uma tarefa fácil e tem sido apresentada na forma de índices que geralmente qualificam o grau de severidade com maior ou menor detalhes. Como a escolha do tratamento está intimamente ligada à gravidade do defeito, o objetivo deste artigo é apresentar os aspectos clínicos da fluorose dental representadas por meios do índice de Thylstrup-Fejerskov (1978). Os escores de severidade são apresentadas de acordo com as características histológicas e as diferenças entre eles serão discutidas a fim de permitir ao dentista diagnosticar corretamente e escolher o tratamento mais adequado para o paciente com FD.

Resumen La fluorosis dental (FD) es un defecto del desarrollo del esmalte dental causado por la ingesta crónica y excesiva de fluoruro, que resulta en un esmalte hipomineralizado y poroso. Clínicamente se manifiesta desde manchas y delicadas líneas blancas hasta manchas opacas que cubren parte o toda la superficie del esmalte, el cual es susceptible a pigmentaciones o fracturas post-eruptivas. Sin embargo, establecer el grado de compromiso de los dientes no es una tarea fácil y para esto se han presentado índices que determinan el grado de severidad con mayor o menor detalle. Como la decisión de tratamiento está estrechamente relacionada a la gravedad del defecto, el objetivo de este artículo es presentar los aspectos clínicos de la fluorosis dental de acuerdo al índice de Thylstrup-Fejerskov (1978). Los grados de severidad son representados de acuerdo con las características histológicas y las diferencias entre ellos son discutidas para que el odontólogo pueda diagnosticas correctamente y escoger el tratamiento más adecuado para el paciente con FD.

Simple, quantitative method for low molecular weight dissolved organic matter extracted from natural waters based upon high performance counter-current chromatography.

A simple, high-performance counter-current chromatography method with sequential UV absorbance (254 nm) and evaporative light scattering detection (ELSD) was developed for the quantification of pre-extracted low molecular weight dissolved organic matter (DOM) extracted from natural waters. The method requires solid-phase extraction (SPE) extraction of only small volumes of water samples, here using poly(styrenedivinylbenzene)-based extraction cartridges (Varian PPL). The extracted and concentrated DOM was quantified using reversed-phase high-performance counter-current chromatography (HPCCC), with a water/methanol (5:5) mobile phase and hexane/ethyl acetate (3:7) stationary phase. The critical chromatographic parameters were optimised, applying a revolution speed of 1900 rpm and a flow-rate of 1 mL min(-1). Under these conditions, 50 µL of extracted DOM solution could be injected and quantified using calibration against a reference natural dissolved material (Suwannee River), based upon UV absorbance at 254 nm and ELSD detection. Both detection methods provided excellent linearity (R(2) > 0.995) for DOM across the concentration ranges of interest, with limits of detection of 4 µg ml(-1) and 7 µg ml(-1) for ELSD and UV absorbance, respectively. The method was validated for peak area precision (<5%), and accuracy and recovery based upon spiking seawater samples prior to extraction, together with DOM solutions post-extraction (>95% recovery). The developed method was applied to the determination of the concentration of DOM in seawater, based upon initial sample volumes as small as 20 mL.

An Empirical Overview of the No Free Lunch Theorem and Its Effect on Real-World Machine Learning Classification.

A sizable amount of research has been done to improve the mechanisms for knowledge extraction such as machine learning classification or regression. Quite unintuitively, the no free lunch (NFL) theorem states that all optimization problem strategies perform equally well when averaged over all possible problems. This fact seems to clash with the effort put forth toward better algorithms. This letter explores empirically the effect of the NFL theorem on some popular machine learning classification techniques over real-world data sets.

Chromatographic methods for the isolation, separation and characterisation of dissolved organic matter.

This review presents an overview of the separation techniques applied to the complex challenge of dissolved organic matter characterisation. The review discusses methods for isolation of dissolved organic matter from natural waters, and the range of separation techniques used to further fractionate this complex material. The review covers both liquid and gas chromatographic techniques, in their various modes, and electrophoretic based approaches. For each, the challenges that the separation and fractionation of such an immensely complex sample poses is critically reviewed.

Sonogashira and "Click" reactions for the N-terminal and side-chain functionalization of peptides with [Mn(CO)3(tpm)]+-based CO releasing molecules (tpm = tris(pyrazolyl)methane).

A recently identified photoactivatable CO releasing molecule (CORM) based on [Mn(CO)(3)(tpm)](+) was conjugated to functionalized amino acids and model peptides using the Pd-catalyzed Sonogashira cross-coupling and the alkyne-azide 1,3-dipolar cycloaddition ("Click reaction"). Both were found to be fully compatible with all functional groups present. The CORM-peptide conjugates were isolated in reasonable yield and high purity, as indicated by IR spectroscopy, ESI mass spectrometry and RP-HPLC. The myoglobin assay was used to demonstrate that they have CO release properties identical those of the parent compound. This work thus opens the way for a targeted delivery of CORMs to cellular systems.

Fluoruración de la sal: una estrategia "global" para la prevención de la caries dental / Salt fluoridation: a “global strategy” for the prevention of dental caries

La sal es un vehículo seguro, económico y estable para yodo y flúor. La sal es utilizada en todo el mundo para la preparación de alimentos en los hospitales, en las guarniciones militares, en las cafeterías escolares y en las cocinas de los hogares. El consumo diario es casi igual, en diferentes culturas, 8 a 10 gramos/día/persona; con esta cantidad una sobre dosis de sal es casi imposible. En muchos países, los administradores de salud pública, han recomendado la incorporación del flúor en el agua, la sal y la leche. La fluoruración de la sal para consumo humano se inició en Suiza en 1955, en Colombia en 1963, como una medida de prevención contra la caries dental. La incorporación de 200-250 mg del ión F por kg/sal, dio como resultado reducciones en la prevalencia de caries dental, en niños de 12 años, en rangos que van del 80- 90 por ciento en Suiza (COPD); 73 por ciento en Jamaica; 40 por ciento en Costa Rica; 59.7 por ciento en Colombia. La fluoruración de la sal es la medida de salud pública más efectiva y económica para la prevención masiva de la caries dental. El riesgo de ingerir “la dosis tóxica probable” (DTP), mediante la ingestión de sal fluorurada, es virtualmente imposible...

Linfomas del tracto gastrointestinal: reporte de 19 casos / Lymphomas of the gastrointestinal tract: report of 19 cases

Se analizaron 19 casos de linfomas no Hodgkin gastrointestinales primarios (en estadío IE o IIE) en el Hospital México, San José, Costa Rica, durante 23 años, de setiembre de 1969 a agosto de 1992. Once pacientes eran hombres y 8 mujeres, con una relación hombre/mujer de 1,4:1. El ámbito de edad fue de 17-78 años, (media de 51,4 años, mediana de 57). El 73 por ciento de los casos se presentó en pacientes mayores de 40 años. La localización predominante fue el estómago, seguida por el intestino delgado y el colon. La sintomatología fue indistinguible de tumores gástricos de extirpe epitelial. El estudio de gabinete más contributorio en los caso de linfoma gástrico fue la gastroscopía; la serie gastroduodenal aportó el diagnóstico en un 58 por ciento de los casos. La biopsia endoscópica fue poco contributoria. Sólo el 37 por ciento de los casos se consideró con enfermedad localizada (estadío I). Se efectuó resección quirúrgica en todos los casos : 12 gastrectomías y 7 resecciones intestinales, con radio y/o quimioterapia adyuvante en 13/19 casos. En el 63 por ciento de los casos la lesión fue única. El tipo histológico más frecuente fue el linfoma difuso de células grandes no hendidas. Cinco casos presentaron perforación espontánea preoperatoria, con alta morbimortalidad. La supervivencia a 5 años por el método de Kaplan-Meir fue del 50 por ciento , con un tiempo de supervivencia de 58 meses. El 70 por ciento de las muertes ocurrió durante el primer año después del diagnóstico. El linfoma gástrico presentó mayor sobrevida (58 por ciento a los 5 años, media de 129 meses) que el de localización intestinal (28,6 por ciento a los 5 años para el estadío clínico menor(64 por ciento a los 5 años para el estadío I, 42 por ciento a los 5 años para el estadío II). Sin embargo, estas diferencias no fueron estadísticamente significativas.

Desconexión porto-azigos y transección gástrica en el tratamiento de las várices esofágicas sangrantes / Portal azygous disconnection and gastric transsection in treatment of bleeding esophageal varices

Veintitrés pacientes (12 masculinos y 11 femeninos) con várices esofágicas sangrantes e hipertensión portal fuero sometidos a una desconexión porto-ázigos con transección gástrica según la técnica de Tanner. La cirrosis hepática fue la causa más frecuente de la hipertensión portal (86 por ciento ). De acuerdo a la clasificación de Child, 13 pacientes pertenecían a la grupo A, 7 al grupo B y 8 al grupo C. Seis pacientes presentaron sangrado por várices esofágicas en el postoperatorio inmediato y nueve en los dos años siguientes. Los ocho pacientes restantes no presentaron complicaciones durante el período de seguimiento en los primeros 24 meses. Se concluye que la desconexión porto-ázigos con transección gástrica es una alternativa para la escleroterapia de várices esofágicas sangrantes en los pacientes con una buena función hepática tipo Child A o en la hipertensión portal tipo presinusoidal (prehepática)

Cystosarcoma Phylloides / Cystosarcoma Phylloides

A pesar de ser considerada como una neoplasia rara, el Cystosarcoma Phylloides constituye aún el tipo más frecuente de lesión sarcomatosa de la glándula mamaria. El carácter benigno o maligno de la misma aún no se establece con claridad y su capacidad para dar metástasis o recurrir es impredecible. Este es un estudio retrospectivo de 12 pacientes del Hospital México en San José, Costa Rica, tratadas por este tipo de neoplasia desde 1 de setiembre de 1969 hasta el 30 de abril de 1990. Se analizan la edad de las pacientes, su fertilidad, antecedentes de fibroadenoma, diagnóstico clínico previo, evolución post operatoria, tipo de intervención quirúrgica, hallazgos anatomopatológicos, características de la lesión y evolución postoperatoria