53 research outputs found

    Вартісне оцінювання запасів мінеральних ресурсів гірничодобувного підприємства

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    Naturfasern sind leicht, günstig und nachwachsend. Deswegen gewinnen sie auch für Strukturbauteile an Bedeutung. Dringt Feuchtigkeit in die Fasern ein, leiden jedoch ihre mechanischen Eigenschaften. Kavitätenpolymerisation kann die Hohlräume der Fasern schließen, sodass die Naturfasern weniger Wasser aufsaugen

    Asymmetric Bethe-Salpeter equation for pairing and condensation

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    The Martin-Schwinger hierarchy of correlations are reexamined and the three-particle correlations are investigated under various partial summations. Besides the known approximations of screened, ladder and maximally crossed diagrams the pair-pair correlations are considered. It is shown that the recently proposed asymmetric Bethe-Salpeter equation to avoid unphysical repeated collisions is derived as a result of the hierarchical dependencies of correlations. Exceeding the parquet approximation we show that an asymmetry appears in the selfconsistent propagators. This form is superior over the symmetric selfconsistent one since it provides the Nambu-Gorkov equations and gap equation for fermions and the Beliaev equations for bosons while from the symmetric form no gap equation results. The selfenergy diagrams which account for the subtraction of unphysical repeated collisions are derived from the pair-pair correlation in the three-particle Greenfunction. It is suggested to distinguish between two types of selfconsistency, the channel-dressed propagators and the completely dressed propagators, with the help of which the asymmetric expansion completes the Ward identity and is Φ\Phi-derivable.Comment: 12 pages. 26 figure

    Lessons learned from the Baltic countries' response to the first wave of COVID-19.

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    The Baltic countries of Estonia, Latvia, and Lithuania shared a similar response to the first wave of the COVID-19 pandemic. Using the information available on the COVID-19 Health System Response Monitor platform, this article analyzed measures taken to prevent transmission, ensure capacity, provide essential services, finance the health system, and coordinate their governance approaches. All three countries used a highly centralized approach and implemented restrictive measures relatively early, with a state of emergency declared with fewer than 30 reported cases in each country. Due to initially low COVID-19 incidence, the countries built up their capacities for testing, contact tracing, and infrastructure, without a major stress test to the health system throughout the spring and summer of 2020, yet issues with accessing routine health care services had already started manifesting themselves. The countries in the Baltic region entered the pandemic with a precarious starting point, particularly due to smaller operational budgets and health workforce shortages, which may have contributed to their escalated response aiming to prevent transmission during the first wave. Subsequent waves, however, were much more damaging. This article focuses on early responses to the pandemic in the Baltic states highlighting measures taken to prevent virus transmission in the face of major uncertainties

    Landscape transformations at the dawn of agriculture in southern Syria (10.7–9.9 ka cal. BP): plant-specific responses to the impact of human activities and climate change

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    In southwest Asia, the accelerated impact of human activities on the landscape has often been linked to the development of fully agricultural societies during the middle and late Pre-Pottery Neolithic B (PPNB) period (around 10.2–7.9 ka cal. BP). This work contributes to the debate on the environmental impact of the so-called Neolitisation process by identifying the climatic and anthropogenic factors that contributed to change local and regional vegetation at the time when domesticated plants appeared and developed in southern Syria (around 10.7–9.9 ka cal. BP). In this work a multidisciplinary analysis of plant microremains (pollen and phytoliths) and macroremains (wood charcoal) is carried out along with stable carbon isotope discrimination of wood charcoals in an early PPNB site (Tell Qarassa North, west of the Jabal al-Arab area). Prior to 10.5 ka cal. BP, the results indicate a dynamic equilibrium in the local and regional vegetation, which comprised woodland-steppe, Mediterranean evergreen oak-woodlands, wetland vegetation and coniferous forests. Around 10.5–9.9 ka cal. BP, the elements that regulated the vegetation system changed, resulting in reduced proportions of arboreal cover and the spread of cold-tolerant and wetlands species. Our data show that reinforcing interaction between the elements of the anthropogenic (e.g. herding, fire-related activities) and climatic systems (e.g. temperature, rainfall) contributed to the transformation of early Holocene vegetation during the emergence of fully agricultural societies in southern Syria

    Bauen in Brasilien

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    Im Herbst 2014 fand die große Exkursion 2014 der Fakultät Bauingenieurwesen der HTWG Konstanz nach Brasilien unter der Leitung von Prof. Dr. Horst Werkle und Prof. Dr. Peter Hirschmann statt. Auf dem Programm stand der Besuch der Städte Sao Paulo, Rio de Janeiro und Iguacu. Der Bericht schildert den Besuch interessanter Baustellen und großer Bauprojekte wie des im Bau befindlichen futuristisch anmutenden „Museum of Tomorrow“, des Maracana-Stadions mit seiner neuen Membrandachkonstruktion sowie des zweitgrößten Wasserkraftwerks der Welt

    Bone histology provides insights into the life history mechanisms underlying dwarfing in hipparionins

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    Size shifts may be a by-product of alterations in life history traits driven by natural selection. Although this approach has been proposed for islands, it has not yet been explored in continental faunas. The trends towards size decrease experienced by some hipparionins constitute a good case study for the application of a life history framework to understand the size shifts on the continent. Here, we analysed bone microstructure to reconstruct the growth of some different-sized hipparionins from Greece and Spain. The two dwarfed lineages studied show different growth strategies. The Greek hipparions ceased growth early at a small size thus advancing maturity, whilst the slower-growing Spanish hipparion matured later at a small size. Based on predictive life history models, we suggest that high adult mortality was the likely selective force behind early maturity and associated size decrease in the Greek lineage. Conversely, we infer that resource limitation accompanied by high juvenile mortality triggered decrease in growth rate and a relative late maturity in the Spanish lineage. Our results provide evidence that different selective pressures can precipitate different changes in life history that lead to similar size shifts

    Influences of Domestication and Island Evolution on Dental Growth in Sheep

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    Funder: Department of Zoology, University of CambridgeFunder: Leverhulme Trust; doi: http://dx.doi.org/10.13039/501100000275Abstract: Domestication and island evolution can lead to changes of life history along the slow-fast gradient. Shifts of life history patterns, in turn, are potentially related to alterations of patterns and timing of tooth eruption. Schultz’s rule predicts an earlier eruption of molars relative to premolars as fecundity increases during the domestication process. On the other hand, evolution on a predator-free, resource limited island might lead to a generally slow life history and delayed tooth eruption, as in the Plio-Pleistocene Balearic caprine Myotragus. In this study, we investigate tooth eruption and its relation to life history in a unique sheep population that is an example of both domestication and island evolution: the ancient and feral Soay sheep (Ovis aries) of the St. Kilda archipelago, Scotland. Tooth eruption timing and sequence is investigated in a comparative framework featuring new data on other domestic sheep (O. aries), including European mouflon (O. a. musimon), as well as wild sheep (O. vignei, O. cycloceros, O. arkal, O. orientalis, O. ammon). These data indicate that the order of eruption is similar in wild and domestic sheep, despite the fundamental life history changes that came about with domestication. However, in contrast to other domestic sheep breeds, Soay sheep erupt their teeth at an absolute older age and also tend to grow more slowly, which resembles the evolutionary trend in island-adapted Myotragus. Despite these similarities, Soay sheep do not share the slow life history pattern inferred for Myotragus, highlighting the distinctive nature of tooth eruption in Soay sheep

    Traces of trauma – a multivariate pattern analysis of childhood trauma, brain structure and clinical phenotypes

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    Background: Childhood trauma (CT) is a major yet elusive psychiatric risk factor, whose multidimensional conceptualization and heterogeneous effects on brain morphology might demand advanced mathematical modeling. Therefore, we present an unsupervised machine learning approach to characterize the clinical and neuroanatomical complexity of CT in a larger, transdiagnostic context. Methods: We used a multicenter European cohort of 1076 female and male individuals (discovery: n = 649; replication: n = 427) comprising young, minimally medicated patients with clinical high-risk states for psychosis; patients with recent-onset depression or psychosis; and healthy volunteers. We employed multivariate sparse partial least squares analysis to detect parsimonious associations between combinations of items from the Childhood Trauma Questionnaire and gray matter volume and tested their generalizability via nested cross-validation as well as via external validation. We investigated the associations of these CT signatures with state (functioning, depressivity, quality of life), trait (personality), and sociodemographic levels. Results: We discovered signatures of age-dependent sexual abuse and sex-dependent physical and sexual abuse, as well as emotional trauma, which projected onto gray matter volume patterns in prefronto-cerebellar, limbic, and sensory networks. These signatures were associated with predominantly impaired clinical state- and trait-level phenotypes, while pointing toward an interaction between sexual abuse, age, urbanicity, and education. We validated the clinical profiles for all three CT signatures in the replication sample. Conclusions: Our results suggest distinct multilayered associations between partially age- and sex-dependent patterns of CT, distributed neuroanatomical networks, and clinical profiles. Hence, our study highlights how machine learning approaches can shape future, more fine-grained CT research

    Long-term results of robotic radiosurgery for non brachytherapy patients with cervical cancer

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    Background!#!Consolidation brachytherapy is a critical treatment component for cervical cancer patients undergoing primary chemoradiation. Some patients are unsuitable for brachytherapy for a variety of reasons. The use of alternatives (LINAC-based stereotactic radiosurgery or external beam boosts) compromise oncologic results in cervical cancer patients. Thus, we evaluated the value of brachytherapy-like doses prescriptions using robotic radiosurgery (CyberKnife®, CR, Acuuray, Sunnyvale, CA, USA).!##!Methods!#!From 06/2011 to 06/2015, 31 patients (median age 53 years; range 30-77 years) with histologically proven FIGO stages IB-IVB cervical cancer underwent primary chemoradiation. All patients were either not suitable for intracervical brachytherapy for a variety of reasons or refused the brachytherapy. To achieve an adequate dose within the tumor, a CK boost was applied after fiducial implantation. In 29 patients, a dose of either five times 6 Gy or five times 5 Gy was prescribed to the target volume. Two patients received three times 5 Gy. The target dose was prescribed to the 70% isodose. Treatment toxicity was documented once weekly regarding vaginal mucositis, bladder, and bowel irritation according to CTCAE v. 4.03. If possible 3 months after completion of treatment intracervical curettage was performed to exclude residual tumor and the patients were followed up clinically. Sparing of organs at risk (OAR) and outcome in terms of local control (LC), overall survival (OS), and progression-free survival (PFS) were assessed.!##!Results!#!Of the 31 patients, 30 have completed CK boost therapy. The median follow-up time was 40 months (range 5-84 months). General treatment tolerability was good. Except for 1 patient, who had diarrhea grade 3, no treatment related side effects above grade 2 were reported. Sparing of OAR was excellent. The 1‑, 3‑, and 5‑year OS rates were 89, 60, and 57% respectively across all stages. Seven patients showed progression (28%), only two of them with local relapse (8%), resulting in an LC rate of 92% after 3 and 5 years. Mean PFS was 41 months (range 2-84 months). Patients with local recurrence had PFS of 5 and 8 months. Five patients developed distant metastases. Fifteen patients (48%) underwent intracervical curettage 3 months after completion of treatment of which 14 (93%) had complete pathologic response.!##!Conclusion!#!Brachytherapy remains the standard of care for patients diagnosed with cervical cancer and indication for primary chemoradiation. In terms of local control, CyberKnife®-based boost concepts provide excellent local control. It can be an alternative for patients who cannot receive adequate brachytherapy. Distant relapse still remains a challenge in this context
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