The genetic basis of nonobstructive azoospermia is unknown in the majority of infertile men.
We performed array comparative genomic hybridization testing in blood samples obtained from 15 patients ...with azoospermia, and we performed mutation screening by means of direct Sanger sequencing of the testis-expressed 11 gene (TEX11) open reading frame in blood and semen samples obtained from 289 patients with azoospermia and 384 controls.
We identified a 99-kb hemizygous loss on chromosome Xq13.2 that involved three TEX11 exons. This loss, which was identical in 2 patients with azoospermia, predicts a deletion of 79 amino acids within the meiosis-specific sporulation domain SPO22. Our subsequent mutation screening showed five novel TEX11 mutations: three splicing mutations and two missense mutations. These mutations, which occurred in 7 of 289 men with azoospermia (2.4%), were absent in 384 controls with normal sperm concentrations (P=0.003). Notably, five of those TEX11 mutations were detected in 33 patients (15%) with azoospermia who received a diagnosis of azoospermia with meiotic arrest. Meiotic arrest in these patients resembled the phenotype of Tex11-deficient male mice. Immunohistochemical analysis showed specific cytoplasmic TEX11 expression in late spermatocytes, as well as in round and elongated spermatids, in normal human testes. In contrast, testes of patients who had azoospermia with TEX11 mutations had meiotic arrest and lacked TEX11 expression.
In our study, hemizygous TEX11 mutations were a common cause of meiotic arrest and azoospermia in infertile men. (Funded by the National Institutes of Health and others.).
Does media attention drive corporate social responsibility? Zyglidopoulos, Stelios C.; Georgiadis, Andreas P.; Carroll, Craig E. ...
Journal of business research,
November 2012, 2012-11-00, 20121101, Letnik:
65, Številka:
11
Journal Article
Recenzirano
This paper investigates the impact that media attention has on the strengths and weaknesses of a firm's corporate social responsibility (CSR). Drawing on stakeholder theory, the study develops and ...tests two hypotheses concerning the influence that media attention can have on the CSR-strengths and weaknesses of a particular firm. The findings indicate that while increases in media attention are related to increases in CSR-strengths, CSR-weaknesses are not sensitive to changes in media attention.
Scheduling is a major component for the efficient operation of the process industries. Especially in the current competitive globalized market, scheduling is of vital importance to most industries, ...since profit margins are miniscule. Prof. Sargent was one of the first to acknowledge this. His breakthrough contributions paved the way to other researchers to develop optimization-based methods that can address a plethora of process scheduling problems. Despite the plethora of works published by the scientific community, the practical implementation of optimization-based scheduling in industrial real-life applications is limited. In most industries, the optimization of production scheduling is seen as an extremely complex task and most schedulers prefer the use of a simulation-based software or manual decision, which result to suboptimal solutions. This work presents a comprehensive review of the theoretical concepts that emerged in the last 30 years. Moreover, an overview of the contributions that address real-life industrial case studies of process scheduling is illustrated. Finally, the major reasons that impede the application of optimization-based scheduling are critically analyzed and possible remedies are discussed.
•Optimal inventory profile and flow decisions for the COVID-19 Vaccine Supply Chain.•Optimization of daily vaccination plans in the clinics.•Development of a novel mixed-integer linear programming ...model.•A decomposition algorithm to successfully address large-scale problems.•Reactive planning of vaccinations through a rolling-horizon technique.
This work presents a novel framework to simultaneously address the optimal planning of COVID-19 vaccine supply chains and the optimal planning of daily vaccinations in the available vaccination centres. A new mixed integer linear programming (MILP) model is developed to generate optimal decisions regarding the transferred quantities between locations, the inventory profiles of central hubs and vaccination centres and the daily vaccination plans in the vaccination centres of the supply chain network. Specific COVID-19 characteristics, such as special cold storage technologies, limited shelf-life of mRNA vaccines in refrigerated conditions and demanding vaccination targets under extreme time pressure, are aptly modelled. The goal of the model is the minimization of total costs, including storage and transportation costs, costs related to fleet and staff requirements, as well as, indirect costs imposed by wasted doses. A two-step decomposition strategy based on a divide-and-conquer and an aggregation approach is proposed for the solution of large-scale problems. The applicability and efficiency of the proposed optimization-based framework is illustrated on a study case that simulates the Greek nationwide vaccination program. Finally, a rolling horizon technique is employed to reactively deal with possible disturbances in the vaccination plans. The proposed mathematical framework facilitates the decision-making process in COVID-19 vaccine supply chains into minimizing the underlying costs and the number of doses lost. As a result, the efficiency of the distribution network is improved, thus assisting the mass vaccination campaigns against COVID-19.
The performance of a new diagnostic test is frequently evaluated by comparison to a perfect reference test (i.e. a gold standard). In many instances, however, a reference test is less than perfect. ...In this paper, we review methods for estimation of the accuracy of a diagnostic test when an imperfect reference test with known classification errors is available. Furthermore, we focus our presentation on available methods of estimation of test characteristics when the sensitivity and specificity of both tests are unknown. We present some of the available statistical methods for estimation of the accuracy of diagnostic tests when a reference test does not exist (including maximum likelihood estimation and Bayesian inference). We illustrate the application of the described methods using data from an evaluation of a nested polymerase chain reaction and microscopic examination of kidney imprints for detection of
Nucleospora salmonis in rainbow trout.
Routes of avian influenza virus (AIV) dispersal among aquatic birds involve direct (bird-to-bird) and indirect (waterborne) transmission. The environmental persistence of H5N1 virus in natural water ...reservoirs can be assessed by isolation of virus in embryonated chicken eggs. Here we describe development and evaluation of a real-time quantitative reverse transcription (RT)-PCR (qRT-PCR) method for detection of H5N1 AIV in environmental water. This method is based on adsorption of virus particles to formalin-fixed erythrocytes, followed by qRT-PCR detection. The numbers of hemagglutinin RNA copies from H5N1 highly pathogenic AIV particles adsorbed to erythrocytes detected correlated highly with the infectious doses of the virus that were determined for three different types of artificially inoculated environmental water over a 17-day incubation period. The advantages of this method include detection and quantification of infectious H5N1 AIVs with a high level of sensitivity, a wide dynamic range, and reproducibility, as well as increased biosecurity. The lowest concentration of H5N1 virus that could be reproducibly detected was 0.91 50% egg infective dose per ml. In addition, a virus with high virion stability (Tobacco mosaic virus) was used as an internal control to accurately monitor the efficiency of RNA purification, cDNA synthesis, and PCR amplification for each individual sample. This detection system could be useful for rapid high-throughput monitoring for the presence of H5N1 AIVs in environmental water and in studies designed to explore the viability and epidemiology of these viruses in different waterfowl ecosystems. The proposed method may also be adapted for detection of other AIVs and for assessment of their prevalence and distribution in environmental reservoirs.
Summary
The aim of this study was to determine the effect(s) of dietary omega‐3 polyunsaturated fatty acids (ω‐3 PUFA) on rabbit semen. Adult rabbit bucks were assigned to two groups that were given ...two diets, a standard diet (control) and a diet supplemented with ω‐3 PUFA. Sperm samples were collected from all bucks with the use of an artificial vagina in 20‐day intervals, for a total period of 120 days. The enrichment of membranes in ω‐3 PUFA was manifested by the elevation of the 22:5 ω‐3 (docosapentaenoic acid DPA) levels within 40 days. This increase in DPA content did not affect semen characteristics (i.e., concentration, motility and viability). However, it was associated with the induction of lipid peroxidation in spermatozoa, as determined on the basis of the malondialdehyde content. Lipid peroxidation was associated with DNA fragmentation in ω‐3 PUFA‐enriched spermatozoa and a concomitant increase in plasminogen activator (PA) activity. The effects of ω‐3 PUFA on sperm cells were evident within 40 days of ω‐3 PUFA dietary intake and exhibited peack values on day 120. Our findings suggest that an ω‐3 PUFA‐rich diet may not affect semen characteristics; however, it may have a negative impact on the oxidative status and DNA integrity of the spermatozoa, which was associated with an induction of PAs activity.
Models for multiple-test screening data generally require the assumption that the tests are independent conditional on disease state. This assumption may be unreasonable, especially when the ...biological basis of the tests is the same. We propose a model that allows for correlation between two diagnostic test results. Since models that incorporate test correlation involve more parameters than can be estimated with the available data, posterior inferences will depend more heavily on prior distributions, even with large sample sizes. If we have reasonably accurate information about one of the two screening tests (perhaps the standard currently used test) or the prevalences of the populations tested, accurate inferences about all the parameters, including the test correlation, are possible. We present a model for evaluating dependent diagnostic tests and analyse real and simulated data sets. Our analysis shows that, when the tests are correlated, a model that assumes conditional independence can perform very poorly. We recommend that, if the tests are only moderately accurate and measure the same biological responses, researchers use the dependence model for their analyses.
Optimal production planning and scheduling in breweries Georgiadis, Georgios P.; Elekidis, Apostolos P.; Georgiadis, Michael C.
Food and bioproducts processing,
January 2021, 2021-01-00, 20210101, Letnik:
125
Journal Article
Recenzirano
Display omitted
•A planning and scheduling model for Breweries is presented.•An efficient MILP-based solution strategy for large-scale models.•A number of test cases illustrates the superiority of ...the proposed model.•Near-optimal production plans are generated, leading to significant economic benefits of the brewing industry.
This work considers the optimal production planning and scheduling problem in beer production facilities. The underlying optimization problem is characterized by significant complexity, including multiple production stages, several processing units, shared resources, tight design and operating constraints and intermediate and final products. Breweries are mainly differentiated to the rest of the beverage industries in terms of long lead times required for the fermentation/maturation process of beer. Therefore, synchronizing the production stages is an extremely challenging task, while the long time horizon leads to larger and more difficult optimization problems. In this work we present a new MILP model, using a mixed discrete-continuous time representation and the immediate precedence framework in order to minimize total production costs. A number of test cases are used to illustrate the superiority of the proposed model in terms of computational efficiency and solution quality compared with approaches developed in other research contributions. The proposed model provides consistently better solutions and improvements of up to 50% are reported. In order to address large-scale problem instances and satisfy the computation limitations imposed by the industry, a novel MILP-based solution strategy is developed, that consists of a constructive and an improvement step. As a result, near-optimal solutions for extremely large cases consisting of up to 30 fermentation tanks, 5 filling lines and 40 products are generated in less than two hours. Finally, the proposed method is successfully applied to a real-life case study provided by a Greek brewery and near-optimal schedules are generated in relatively short CPU times.
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