804,389 research outputs found

    A new digital image correlation software for displacements field measurement in structural applications

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    Recently, there has been a growing interest in studying non-contact techniques for strain and displacement measurement. Within photogrammetry, Digital Image Correlation (DIC) has received particular attention thanks to the recent advances in the field of low-cost, high resolution digital cameras, computer power and memory storage. DIC is indeed an optical technique able to measure full field displacements and strain by comparing digital images of the surface of a material sample at different stages of deformation and thus can play a major role in structural monitoring applications. For all these reasons, a free and open source 2D DIC software, named py2DIC, was developed at the Geodesy and Geomatics Division of DICEA, University of Rome "La Sapienza". Completely written in python, the software is based on the template matching method and computes the displacement and strain fields. The potentialities of Py2DIC were evaluated by processing the images captured during a tensile test performed in the Lab of Structural Engineering, where three different Glass Fiber Reinforced Polymer samples were subjected to a controlled tension by means of a universal testing machine. The results, compared with the values independently measured by several strain gauges fixed on the samples, demonstrate the possibility to successfully characterize the deformation mechanism of the investigated material. Py2DIC is indeed able to highlight displacements at few microns level, in reasonable agreement with the reference, both in terms of displacements (again, at few microns in the average) and Poisson's module

    Maternal haemoglobin concentrations before and during pregnancy and stillbirth risk: A population-based case-control study

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    Background: Results of previous studies on the association between maternal haemoglobin concentration during pregnancy and stillbirth risk are inconclusive. It is not clear if haemoglobin concentration before pregnancy has a role. Using prospectively collected information from pre-pregnancy and antenatal visits, we investigated associations of maternal haemoglobin concentrations before and during pregnancy and haemoglobin dilution with stillbirth risk. Methods: In a population-based case-control study from rural Golestan, a province in northern Iran, we identified 495 stillbirths (cases) and randomly selected 2,888 control live births among antenatal health-care visits between 2007 and 2009. Using logistic regression, we estimated associations of maternal haemoglobin concentrations, haemoglobin dilution at different stages of pregnancy, with stillbirth risk. Results: Compared with normal maternal haemoglobin concentration (110-120g/l) at the end of the second trimester, high maternal haemoglobin concentration (≥140g/l) was associated with a more than two-fold increased stillbirth risk (OR = 2.31, 95% CI [1.30-4.10]), while low maternal haemoglobin concentration (<110g/l) was associated with a 37% reduction in stillbirth risk. Haemoglobin concentration before pregnancy was not associated with stillbirth risk. Decreased haemoglobin concentration, as measured during pregnancy (OR = 0.61, 95% CI [0.46, 0.80]), or only during the second trimester (OR = 0.75, 95% CI [0.62, 0.90]), were associated with reduced stillbirth risk. The associations were essentially similar for preterm and term stillbirths. Conclusions: Haemoglobin concentration before pregnancy is not associated with stillbirth risk. High haemoglobin level and absence of haemoglobin dilution during pregnancy could be considered as indicators of a high-risk pregnancy. © 2016 The Author(s)

    Selected Readings on Bibliographic Instruction, 1980-1992

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    Paternity after microscopic inguinal surgery of varicocele in infertile males: A 5-years follow up

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    Objectives: Infertility affects about 15% of couples. One of the most common causes of male infertility is varicocele. In this study, the live birth rate after microscopic inguinal varicocelectomy and some related factors were studied in Northeast of Iran. Design and patients: In this cross-sectional study, 976 infertile males who underwent microscopic inguinal varicocelectomy (2004-2009) in an academic hospital were studied and 264 were randomly selected. Female factors were ruled out. Data regarding age, varicocele grade and live birth rate were recruited and entered into SPSS-14 software; T-test and χ2 were used to analyze the variables. Results: The mean (±SD) age was 29.09 (±4.80) years, 139 (52.7%) reported to have a successful result after a mean (±SD) duration of 21.74 (±6.24) months. Unilateral varicocelectomy had significantly more positive results (58.8%) than bilateral (20.9%) but the relationship with grade was not significant. Primary type had 54.5% live birth v.s. 31.8% in secondary type (P-value< 0.05). The mean duration between operation and live birth was significantly different in primary and secondary type (P-value<0.05). Conclusions: Surgery of primary infertility could reveal to a higher live birth rate in a much shorter duration; also unilateral varicoceles are better responders to the surgery

    Mass wasting at the base of the South central Chilean continental margin: the Reloca Slide

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    Offshore south central Chile (35° S–42° S), the morphology of the lowermost continental slope and trench floor witnesses a voluminous submarine mass-wasting event. The blocky slide body deposited in the Chile Trench at 73°46´ W 35°35´ S was targeted for study during RRS JAMES COOK Cruise JC23 and termed Reloca Slide. Its size of about 24 km3, its steep and high headscarp, the spatial distribution of slide deposits and the cohesive nature of major slide blocks make it interesting to address the issue of tsunami generation. We have obtained seismic reflection data that partly reveal the internal structure of the slide body. Gravity core samples were retrieved that will allow the slide to be dated and linked to the history of sedimentation and slope stability along this particular segment of the Chilean convergent margin. At present we assume a Holocene age for the sliding event

    The direct response of the gonads to cues of stress in a temperate songbird species is season-dependent.

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    The gonadotropin releasing hormone (GnRH) system in the hypothalamus is often considered the final point in integration of environmental cues as they pertain to the reproductive axis. However, cues such as stress and food availability are detectable in the plasma (as glucocorticoid and metabolic fuel fluctuations). Vertebrate gonads express glucocorticoid receptor, therefore we hypothesized that the gonads can detect and respond directly to cues of stress. We provide evidence here that, in addition to regulation by the brain, the gonads of European starlings (Sturnus vulgaris) respond directly to fluctuations in corticosterone and metabolic fuels by modulating sex steroid secretion. Using a 4-h gonad culture, we show that physiologically-relevant concentrations of corticosterone and metabolic stress (via use of the glucose utilization inhibitor 2-deoxy-D-glucose and the fatty acid oxidation inhibitor ethyl 2-mercaptoacetate (2DG/MA)) can directly decrease testosterone and estradiol secretion from luteinizing hormone and follicle-stimulating hormone (LH/FSH)-stimulated testes and ovaries. This effect is regulated seasonally. Prior to the breeding season, testes and ovaries respond to corticosterone and 2DG/MA by significantly decreasing gonadal steroid release. Within the breeding season, the testes do not respond to these cues of stress, while the ovaries respond only to corticosterone. This seasonal difference in response may be due in part to the influence of these cues of stress on gonadal neuropeptide expression: corticosterone upregulates GnIH expression in the testes while metabolic stress upregulates GnIH in the ovaries. Thus the gonads can directly respond to fluctuations in corticosterone and metabolic fuels during a time of critical importance to the onset of breeding

    Still minding the gap? Reflecting on transitions between concepts of information in varied domains

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    This conceptual paper, a contribution to the tenth anniversary special issue of information, gives a cross-disciplinary review of general and unified theories of information. A selective literature review is used to update a 2013 article on bridging the gaps between conceptions of information in different domains, including material from the physical and biological sciences, from the humanities and social sciences including library and information science, and from philosophy. A variety of approaches and theories are reviewed, including those of Brenner, Brier, Burgin and Wu, Capurro, Cárdenas-García and Ireland, Hidalgo, Hofkirchner, Kolchinsky and Wolpert, Floridi, Mingers and Standing, Popper, and Stonier. The gaps between disciplinary views of information remain, although there has been progress, and increasing interest, in bridging them. The solution is likely to be either a general theory of sufficient flexibility to cope with multiple meanings of information, or multiple and distinct theories for different domains, but with a complementary nature, and ideally boundary spanning concepts

    Is opioid dependency related to coping strategies?

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    Using opioid for recreational purposes has a very long history in Iran. Social influence is a useful framework in understanding how the social environment affects the individual's behavioral choices to use drugs. We compared opioid dependents (n=149) with controls (n=221) on measures of coping strategies using the Jalowiec Coping Scale and some socioeconomic factors. The differences in 10 of 15 coping strategies were significant in the study groups (P<0.05). Although, the combined score of problem-oriented and affective-oriented items did not show any significant difference between the two groups. There was a significant relation between opioid dependence with smoking cigarettes (P<0.001), lower education (P=0.002), being employed (P<0.001), having children (P<0.001), and being married (P<0.001). Educational programs to improve problem solving and coping skills can be helpful to reduce the rate of dependency to opioid and smoking cigarettes. © 2015, Sadeghali Taziki, et al
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