A general framework for quantifying the effects of DNA repair inhibitors on radiation sensitivity as a function of dose

Purpose. Current methods for quantifying effects of DNA repair modifiers on radiation sensitivity assume a constant effect independent of the radiation dose received. The aim of this study was to develop and evaluate a modelling strategy by which radiation dose dependent effects of DNA repair inhibitors on clonogenic survival might be identified and their significance assessed. Methods. An indicator model that allowed quantification of the Sensitiser Effect on Radiation response as a function of Dose (SERD) was developed. This model was fitted to clonogenic survival data derived from human tumour and rodent fibroblast cell lines irradiated in the presence and absence of chemical inhibitors of poly(ADP-ribose) polymerase (PARP) activity. Results. PARP inhibition affected radiation response in a cell cycle and radiation dose dependent manner, and was also associated with significant radiation-independent effects on clonogenic survival. Application of the SERD method enabled identification of components of the radiation response that were significantly affected by PARP inhibition and indicated the magnitude of the effects on each component. Conclusion. The proposed approach improves on current methods of analysing effects of DNA repair modification on radiation response. Furthermore, it may be generalised to account for other parameters such as proliferation or dose rate to enable its use in the context of fractionated or continuous radiation exposures

Changes in adult blood pressure associated with modernization on islands of Ambae, Aneityum, and Efate in the Republic of Vanuatu: 2007-2011.

Changes in behavior and lifestyle associated with modernization contribute to health transitions in developing countries. In the Republic of Vanuatu, a developing South Pacific island nation, these behavioral and lifestyle changes are contributing to a rapid shift in health burdens, causing non-communicable disease such as cardiovascular disease, diabetes and obesity to increase in prevalence. This study evaluates the impact of modernization on blood pressure and prevalence of hypertension on three islands of varying economic development in Vanuatu. Data were collected in 2007 (n=568) and 2011 (n=1,246) from adult males and females across the islands of Ambae, a rural island, Aneityum, a rural island with tourism, and Efate, an urban island. Participants answered questions regarding their lifestyle and health, and had biophysical and anthropometric measurements taken including blood pressure, stature, weight, and percent body fat. Analyses indicate that the percentage of individuals with hypertensive diastolic blood pressure values increased significantly between 2007 and 2011 across all three islands. Additionally, in both survey years and among both men and women, mean diastolic blood pressures was significantly greater on Efate, the most modernized island in our sample, than on Aneityum and Ambae. Finally, we observed a positive association between blood pressure and smoking tobacco, body mass index, consuming animal protein, and having access to technological goods. These data highlight the remarkable rapidity with which the prevalence of hypertension can increase during health transition. Our data indicate some behaviors associated with these increases might provide promising targets for prevention and intervention strategies in Vanuatu and similar countries experiencing the rapid increase in non-communicable diseases associated with health transition

A baseline estimation procedure to improve MDA evaluation in gamma-ray spectrometry

The evaluation of minimum detectable activity (MDA) for a radionuclide in a gamma-ray spectrum is generally carried out through the computation of a suitable background count. This task is sometimes difficult for complex spectra for the presence of many photopeaks which make the trend of continuum extremely variable due to multiple dispersion effects and interference factors. It follows that the MDA assessment must be take into account the contributions of all gamma emissions of radionuclides contained in a sample and its value can be significantly higher than that determined by considering only the background of the spectrometric system due to the overlapping of other peaks. A procedure or an algorithm to determine, each time, the count values to be used for the calculation of MDA is interesting and useful. In this work, some of the more recent algorithms proposed for background subtraction in a gamma-ray spectrum have been examined, applying them in an inverse way for the evaluation of baseline trend in the whole energy range. Among the algorithms examined, particular attention was paid to the application of SNIP (statistical sensitive nonlinear iterative peak clipping) algorithms, which are the simplest to adopt and implement in an application procedure. The results obtained in the analysis of test gamma-ray spectra are satisfactory and allow to quickly determine the MDA values with a formulation based on the ISO-11929 standard

Effect of influenza-induced fever on human bioimpedance values

BACKGROUND AND AIMS: Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. METHODS: Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. RESULTS: For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). CONCLUSIONS: There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states

Uso del hábitat por áfidos y sus parasitoides en la interfase cultivo-vegetación silvestre en una granja orgánica

Plant-aphid-parasitoid interactions and parasitism rates were assessed in adjacent cultivated and noncultivated habitats in an organic vegetable farm in a chaco serrano woodland, Córdoba, Argentina. Seven aphid species on eight vegetable species were found in the cultivated habitat. Macrosiphum euphorbiae was present on all vegetable species. Four parasitoid species were recorded, of which Diaretiella rapae was the most common. It provided 21.32% of parasitism on Brevicoryne brassicae. In the non-cultivated habitat, 36 plant species hosted 22 aphid species and five parasitoid species. The aphid Myzus persicae was present on 17 plant species of eight different families. Macrosiphoniella artemisiae was the most abundant aphid species, with the associated Aphidius sp. being the most abundant parasitoid. Aphidius polygonaphis provided 10% of parasitism on Uroleucon aeneus. We report several wild plant species as important reservoirs of parasitoids, which are potential controllers of many pest aphid species.Se estudiaron las interacciones planta-áfido-parasitoide y las tasas de parasitismo en ambientes cultivados y no cultivados adyacentes, en una granja orgánica de hortalizas en el chaco serrano de Córdoba, Argentina. Siete especies de áfidos fueron encontradas en las ocho especies de hortalizas estudiadas en el ambiente cultivado. Macrosiphum euphorbiae estuvo presente en todas las hortalizas. Se registraron cuatro especies de parasitoides, siendo Diaretiella rapae la más frecuente. Produjo 21,32% de parasitismo en Brevicoryne brassicae. En el ambiente no cultivado 36 especies de plantas hospedaron 22 especies de áfidos y cinco especies de parasitoides. El áfido Myzus persicae estuvo presente en 17 especies de plantas de ocho familias diferentes. Macrosiphoniella artemisiae fue el áfido más abundante, al igual que su parasitoide Aphidius sp. Aphidius polygonaphis produjo 10% de parasitismo en Uroleucon aeneus. Reportamos numerosas especies de plantas silvestres como importantes reservorios de parasitoides, los cuales son potenciales controladores de muchas especies de áfidos plaga.Fil: Jaureguiberry, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Buffa, Liliana M.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Delfino, Miguel Angel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

On traces for H(curl,Ω) in Lipschitz domains

AbstractWe study tangential vector fields on the boundary of a bounded Lipschitz domain Ω in R3. Our attention is focused on the definition of suitable Hilbert spaces corresponding to fractional Sobolev regularities and also on the construction of tangential differential operators on the non-smooth manifold. The theory is applied to the characterization of tangential traces for the space H(curl,Ω). Hodge decompositions are provided for the corresponding trace spaces, and an integration by parts formula is proved

Cross-habitat usage by crop aphids and their parasitoids in the cropnoncrop interface in an organic vegetable farm.

Plant-aphid-parasitoid interactions and parasitism rates were assessed in adjacent cultivated and noncultivated habitats in an organic vegetable farm in a chaco serrano woodland, Córdoba, Argentina. Seven aphid species on eight vegetable species were found in the cultivated habitat. Macrosiphum euphorbiae was present on all vegetable species. Four parasitoid species were recorded, of which Diaretiella rapae was the most common. It provided 21.32% of parasitism on Brevicoryne brassicae. In the non-cultivated habitat, 36 plant species hosted 22 aphid species and five parasitoid species. The aphid Myzus persicae was present on 17 plant species of eight different families. Macrosiphoniella artemisiae was the most abundant aphid species, with the associated Aphidius sp. being the most abundant parasitoid. Aphidius polygonaphis provided 10% of parasitism on Uroleucon aeneus. We report several wild plant species as important reservoirs of parasitoids, which are potential controllers of many pest aphid species

Hormigas melívoras (Hymenoptera: Formicidae) en tres fuentes de alimento líquido

Extrafloral nectaries (EFNs) and hemipteran honeydew are liquid food rewards (FRs) that encourage ant visitation in many plant families in a wide variety of habitats. In this study we explored the diversity, distribution and interactions of exudate-gathering ants at three different liquid food rewards: nectar from EFNs on Croton sarcopetalus and honeydew from the aphids Aphis spiraecola and Dysaphis foeniculus on Eupatorium hookerianum (Asteraceae) and Foeniculum vulgare (Apiaceae) respectively. For each FR we measured ant diversity and performed quantitative and qualitative comparisons among ants associated with the FRs. In addition, a linear regression was performed to test for possible associations between aphid and ant abundances in the case of honeydew FRs. Eight out of the 23 ant species found fed on both nectar from EFNs and honeydew from aphids, four of which fed at all FRs. Two ant species visited both aphid species and 13 were found exclusively at either one of the FRs. Brachymyrmex brevicornis was the most abundant ant species and Pheidole sp.2 had the greatest occurrence. Both ant species diversity and richness were higher at EFNs of C. sarcopetalus. Regressions showed positive significant association between ants and aphids abundances both on E. hookerianum and F. vulgare. We can conclude that the three liquid food rewards compared here showed modest similarity in their ant fauna. Furthermore, there was selectiveness of ants towards EFNs of C. sarcopetalus, which might be due to food source attributes rather than co-evolutionary factors.Los nectarios extraflorales (NEFs) y el melado excretado por hemípteros son fuentes de alimento (FsA) que favorecen la participación de hormigas en las interacciones mutualistas que establecen con las plantas y/o hemípteros. El objetivo de este trabajo fue estudiar, en una zona serrana del centro de la provincia de Córdoba, Argentina, la diversidad, distribución e interacción de hormigas melívoras en tres FsA diferentes: néctar de NEFs de Croton sarcopetalus (Euphorbiaceae) y melado de Aphis spiraecola y Dysaphis foeniculus en Eupatorium hookerianum (Asteraceae) y en Foeniculum vulgare (Apiaceae), respectivamente. En cada FA se contabilizaron e identificaron los áfidos y hormigasmelívoras presentes. Se obtuvo la riqueza y abundancia de hormigas y se calcularon los índices de diversidad de Shannon-Wiener y Sorenson (cualitativo y cuantitativo) para comparar las comunidades de hormigas en las diferentes FsA. Por último se realizó una regresión lineal entre la abundancia de áfidos y la abundancia de hormigas melívoras en las dos últimas FsA mencionadas, para determinar si las variables estaban asociadas. De las 23 especies de hormigas registradas, ocho (34.8%) se alimentaron tanto en NEFs como en las colonias de áfidos, de las cuales 4 spp. (17.4%) fueron encontradas simultáneamente en las tres fuentes. Además, dos especies de hormigas visitaron ambas especies de áfidos y 13 especies visitaron exclusivamente alguna de las FsA. Brachymyrmex brevicornis fue la especie más abundante, mientras que Pheidole sp.2 registró la mayor ocurrencia. Tanto la diversidad como la riqueza de especies de hormigas fue mayor en NEFs de C. sarcopetalus. Se encontró una relación positiva significativa entre la abundancia de áfidos y la abundancia de hormigas melívoras tanto sobre E. hookerianum como sobre F. vulgare. Podemos concluir que las tres FA estudiadas mostraron una similitud modesta en su fauna de hormigas. Además se observó selectividad por parte de las hormigas hacia los NEFs de C. sarcopetalus, que podría deberse a las características de la fuente de alimento más que a factores co-evolutivos

Nutritional status in the healthy longeval population from Sardinia (Italy)

n/