Porosity effects on elastic properties of polycrystalline materials: a three-dimensional grain boundary formulation

Polycrystalline materials are widely used in many technological applications of engineering interest. They constitute an important class of heterogeneous materials, and the investigation of the link between their macro and micro properties, main task of the micromechanics [1], is of relevant technological concern. The internal structure of a polycrystalline material is determined by the size and the shape of the grains, by their crystallographic orientation and by different type of defects within them. In this sense, the presence of internal voids, pores, is important to take into account in the determination of the polycrystalline aggregate properties. Porosity exists in almost all materials to some extent and in particular in the polycrystalline ones; it is strictly depending by the conditions in which their construction techniques are set. However, sometimes it is desired for other than structural reasons such us, for example, heat transfer properties, radar reflection etc. For this reason the effects of porosity should be of concern to any polycrystalline material developed for a design. In particular, the macroscopic effects of the pores on polycrystalline materials elastic properties is of high interest and the Young and shear modulus are the major parameter to analyze in this case. In this study the influence of porosity presence on the elastic proprieties of polycrystalline materials is investigated and a 3D grain boundary micro mechanical model for the analysis of porosity in polycrystalline materials is used [2]. Therefore, the volume fraction of porosity, pore size and their distribution can be varied to better simulate the response of a real porous materials to a given load. The formulation is built on a boundary integral representation of the elastic problem for the single grain, that is modelled as 3D linearly elastic orthotropic domain with arbitrary spatial orientation. The artificial polycrystalline morphology is represented using the Voronoi Tessellation. This algorithms, in fact, is widely recognised and used for the generation of microstructural model and it is simple to generate the statistical features of polycrystalline microstructures. The formulation is expressed in terms of intergranular fields, namely displacement and traction that play an important role in polycrystalline micromechanics

zoolog R package: Zooarchaeological analysis with log-ratios

Log Size Indexes (LSI) allow the increase of the number of data and have been used in a number of zooarchaeological studies since 1950. However, some standards to calculate the log ratios remain unpublished, the calculation of the indexes can be tedious, and it is further hindered by the diversity of data recording practices. The R package ‘zoolog’ enables calculation of thousands of log-ratios in seconds, with the advantage that the users can choose between different public references, which increases the repeatability and comparability of the results, allowing the smooth integration of references and databases with heterogeneous nomenclatures. Alternatively, the users may use their own references. This paper presents the main functionalities and procedures enabled by the package ‘zoolog’, together with some examples of use. A real dataset and several examples with R code are provided with the aim of facilitating osteometrical analyses in zooarchaeology.This work was developed as part of the ERC-Starting Grant ZooMWest (Grant agreement 716298)

Atrazine and cancer incidence among pesticide applicators in the agricultural health study (1994-2007).

Atrazine is a triazine herbicide used widely in the United States. Although it is an animal carcinogen, the mechanism in rodents does not appear to operate in humans. Few epidemiologic studies have provided evidence for an association

Chesapeake Bay Dissolved Oxygen Criterion Attainment Deficit: Three Decades of Temporal and Spatial Patterns

Low dissolved oxygen (DO) conditions are a recurring issue in waters of Chesapeake Bay, with detrimental effects on aquatic living resources. The Chesapeake Bay Program partnership has developed criteria guidance supporting the definition of state water quality standards and associated assessment procedures for DO and other parameters, which provides a binary classification of attainment or impairment. Evaluating time series of these two outcomes alone, however, provides limited information on water quality change over time or space. Here we introduce an extension of the existing Chesapeake Bay water quality criterion assessment framework to quantify the amount of impairment shown by space-time exceedance of DO criterion (“attainment deficit”) for a specific tidal management unit (i.e., segment). We demonstrate the usefulness of this extended framework by applying it to Bay segments for each 3-year assessment period between 1985 and 2016. In general, the attainment deficit for the most recent period assessed (i.e., 2014–2016) is considerably worse for deep channel (DC; n = 10) segments than open water (OW; n = 92) and deep water (DW; n = 18) segments. Most subgroups – classified by designated uses, salinity zones, or tidal systems – show better (or similar) attainment status in 2014–2016 than their initial status (1985–1987). Some significant temporal trends (p < 0.1) were detected, presenting evidence on the recovery for portions of Chesapeake Bay with respect to DO criterion attainment. Significant, improving trends were observed in seven OW segments, four DW segments, and one DC segment over the 30 3-year assessment periods (1985–2016). Likewise, significant, improving trends were observed in 15 OW, five DW, and four DC segments over the recent 15 assessment periods (2000–2016). Subgroups showed mixed trends, with the Patuxent, Nanticoke, and Choptank Rivers experiencing significant, improving short-term (2000–2016) trends while Elizabeth experiencing a significant, degrading short-term trend. The general lack of significantly improving trends across the Bay suggests that further actions will be necessary to achieve full attainment of DO criterion. Insights revealed in this work are critical for understanding the dynamics of the Bay ecosystem and for further assessing the effectiveness of management initiatives aimed toward Bay restoration

Effect of deficit irrigation during oil synthesis period on carbohydrates content in olive hedgerows (cv. Arbequina)

During fruit oil synthesis and accumulation period, fruits are the main carbohydrate sink and water stress may modify the reserve availability for next season development. The objective of this study was to evaluate the effect of deficit irrigation during fruit oil synthesis period on next season carbohydrates content. Experiment was carried out in a super high density olive orchard (Olea europaea cv Arbequina) located in La Puebla de Montalbán, Toledo, Spain (39º 48’N, 04º27’W, 516 msnm). Two irrigation level were applied from the middle August until harvest (First November), when most of the 80% of the oil accumulated on fruits occurs. The control treatment (Non stressed) was irrigated until harvest, trying to maintain the root zone close to field capacity. The Stressed treatment was irrigated with water dosage being reduced to 12% of Non stress treatment. Carbohydrates (soluble sugars and starch) were measured on roots, leaves and stems at the end of winter. Differences on carbohydrate concentration were observed on leaves but not in the reserve organs as roots or stems. Leaves of the Stressed trees presented higher carbohydrates content. These results show the important role of carbohydrates on water stress adaptation by osmotic regulation

Shipping amphorae and shipping sheep? Livestock mobility in the north-east Iberian peninsula during the Iron Age based on strontium isotopic analyses of sheep and goat tooth enamel

Animal mobility is a common strategy to overcome scarcity of food and the related over-grazing of pastures. It is also essential to reduce the inbreeding rate of animal populations, which is known to have a negative impact on fertility and productivity. The present paper shows the geographic range of sheep provisioning in different phases of occupation at the Iron Age site of Turó de la Font de la Canya (7th to 3rd centuries BC). Strontium isotope ratios from 34 archaeological sheep and goat enamel, two archaeological bones and 14 modern tree leaves are presented. The isotopic results suggest that sheep and goats consumed at the site were reared locally (within a few kilometres radius) during the whole period of occupation. The paper discusses the isotopic results in light of the socio-political structure of this period, as complex, strongly territorial societies developed during the Iron Age in the north-east Iberian Peninsula

Genotype, environment and their interaction on olive

Resumen del trabajo presentado en la 6th International Conference on the Olive Tree and Olive Products, celebrada en Sevilla (España) del 15 al 19 de octubre de 2018.The wide olive genetic patrimony has revealed high variability for most of the agronomic and oil quality traits of interest in olive growing. Few studies, however, have addressed the interaction of this variability with the environment, a subject of particular interest considering the natural high instability of the Mediterranean climate and the challenge of the predicted climate change. The current work presents results on the interaction between genotype and environment from multi-environment trials of olive cultivars and breeding selections, planted in different edaphoclimatic conditions of Andalusia, Southern Peninsular Spain and Canary Islands. For most of the agronomic and oil quality characters evaluated (flowering phenology, flower quality, pattern of oil accumulation, fatty acid composition and phenol content and composition), significant genotype and environment effects have been observed. For example, olive cultivars grown in Tenerife under much milder winter temperatures than in the Iberian Peninsula showed substantially earlierflowering and oil accumulation. Only in the case of flowering phenology was no significant genotype effect found. Furthermore, a strong genotype x environment effect was highly consistent in all characters considered. Regarding resistance to disease, such as Verticillium wilt, the variability of results from both natural and artificial inoculations also tends to indicate a considerable environmental effect and the need for careful testing of disease evolution. All this information strongly suggests the necessity of comparative trials of olive cultivars for both adequate choice of cultivar and final selection in breeding programs

Redefining the timing and circumstances of the chicken's introduction to Europe and north-west Africa

This is the final version. Available on open access from Cambridge University Press via the DOI in this recordLittle is known about the early history of the chicken (Gallus gallus domesticus), including the timing and circumstances of its introduction into new cultural environments. To evaluate its spatio-temporal spread across Eurasia and north-west Africa, the authors radiocarbon dated 23 chicken bones from presumed early contexts. Three-quarters returned dates later than those suggested by stratigraphy, indicating the importance of direct dating. The results indicate that chickens did not arrive in Europe until the first millennium BC. Moreover, a consistent time-lag between the introduction of chickens and their consumption by humans suggests that these animals were initially regarded as exotica and only several centuries later recognised as a source of ‘food’.Arts and Humanities Research Council (AHRC)Natural Environment Research Council (NERC)Chair of Palaeoanatomy, LMU Munic

The Herbicide Atrazine Activates Endocrine Gene Networks via Non-Steroidal NR5A Nuclear Receptors in Fish and Mammalian Cells

Atrazine (ATR) remains a widely used broadleaf herbicide in the United States despite the fact that this s-chlorotriazine has been linked to reproductive abnormalities in fish and amphibians. Here, using zebrafish we report that environmentally relevant ATR concentrations elevated zcyp19a1 expression encoding aromatase (2.2 µg/L), and increased the ratio of female to male fish (22 µg/L). ATR selectively increased zcyp19a1, a known gene target of the nuclear receptor SF-1 (NR5A1), whereas zcyp19a2, which is estrogen responsive, remained unchanged. Remarkably, in mammalian cells ATR functions in a cell-specific manner to upregulate SF-1 targets and other genes critical for steroid synthesis and reproduction, including Cyp19A1, StAR, Cyp11A1, hCG, FSTL3, LHß, INHα, αGSU, and 11ß-HSD2. Our data appear to eliminate the possibility that ATR directly affects SF-1 DNA- or ligand-binding. Instead, we suggest that the stimulatory effects of ATR on the NR5A receptor subfamily (SF-1, LRH-1, and zff1d) are likely mediated by receptor phosphorylation, amplification of cAMP and PI3K signaling, and possibly an increase in the cAMP-responsive cellular kinase SGK-1, which is known to be upregulated in infertile women. Taken together, we propose that this pervasive and persistent environmental chemical alters hormone networks via convergence of NR5A activity and cAMP signaling, to potentially disrupt normal endocrine development and function in lower and higher vertebrates