Stochastic Optimization: Theory and Applications

As an important branch of applied mathematics, optimization theory, especially stochastic optimization, becomes an important tool for solving multiobjective decision-making problems in random process recently. Many kinds of industrial, biological, engineering, and economic problems can be viewed as stochastic systems, for example, area of communication, gene, signal processing, geography, civil engineering, aerospace, banking, and so forth. Stochastic optimization is suitable to solve the decision-making problems in these stochastic systems

Shallow Remineralization in the Sargasso Sea Estimated from Seasonal Variations in Oxygen and Dissolved Inorganic Carbon

A diagnostic model of the mean annual cycles of dissolved inorganic carbon (DIC) and oxygen below the mixed layer at the Bermuda Atlantic Time-series Study (BATS) site is presented and used to estimate organic carbon remineralization in the seasonal thermocline. The model includes lateral and vertical advection as well as vertical, diffusion. Very good agreement is found for the remineralization estimates based on oxygen and DIC. Net remineralization averaged from mid-spring to early fall is found to be a maximum between 120 and 140 in. Remineralization integrated between 100 (the compensation depth) and 250 m during this period is estimated to be about 1 mol C/sq m. This flux is consistent with independent estimates of the loss of particulate and dissolved organic carbon

Genomic epidemiology of the first epidemic wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Palestine.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus responsible for the COVID-19 pandemic, continues to cause a significant public-health burden and disruption globally. Genomic epidemiology approaches point to most countries in the world having experienced many independent introductions of SARS-CoV-2 during the early stages of the pandemic. However, this situation may change with local lockdown policies and restrictions on travel, leading to the emergence of more geographically structured viral populations and lineages transmitting locally. Here, we report the first SARS-CoV-2 genomes from Palestine sampled from early March 2020, when the first cases were observed, through to August of 2020. SARS-CoV-2 genomes from Palestine fall across the diversity of the global phylogeny, consistent with at least nine independent introductions into the region. We identify one locally predominant lineage in circulation represented by 50 Palestinian SARS-CoV-2, grouping with genomes generated from Israel and the UK. We estimate the age of introduction of this lineage to 05/02/2020 (16/01/2020-19/02/2020), suggesting SARS-CoV-2 was already in circulation in Palestine predating its first detection in Bethlehem in early March. Our work highlights the value of ongoing genomic surveillance and monitoring to reconstruct the epidemiology of COVID-19 at both local and global scales

Determinants and value relevance of UK CEO pay slice

This paper studies the CEO pay slice (CPS) of UK listed firms during the period 2003 to 2009. We investigate the determinants of CPS. We study the links between CPS and measures of firm performance. We find that firms with higher levels of corporate governance ratings and those with more independent boards tend to have higher CPS. In addition, we find that CEOs are more likely to receive lower compensation when they chair the board and when they work in firms with large board size. We also find that higher CPS is positively associated with firm performance after controlling for the firm-specific characteristics and corporate governance variables. We get compatible results when we examine the association between equity-based CPS and firm performance. Our results remain robust to alternative accounting measures of firm performance. Our results suggest that high UK CPS levels do indeed reflect top managerial talent rather than managerial power

To bi or not to bi? La bisessualità in Italia tra cancellazione, stereotipi e affermazione di sé: le sfide per l’educazione

Verso la bisessualità si è sviluppato nel tempo uno spettro di pratiche oppressive (bi-negatività) che includono forme di violenza, discriminazione, denigrazione e cancellazione epistemica: la sua esistenza viene ancora frequentemente negata (bi-erasure) oppure associata a manifestazioni di tipo patologico. Le evidenze scientifiche mostrano come la bi-negatività abbia impatti significativi sulla qualità della vita dei soggetti bi. Con l’obiettivo di approfondire quali siano i contesti e quali gli atteggiamenti, i comportamenti e le esperienze che possono favorire (oppure ostacolare) i vissuti positivi dei soggetti bisessuali – delineando così possibili piste di intervento educativo – è stata condotta un’indagine esplorativa che ha coinvolto complessivamente 519 individui bisessuali italiani (N=519). La raccolta dati è avvenuta a ottobre-novembre 2020, attraverso un questionario semi-strutturato online e i dati qualitativi sono stati codificati. La comunità LGBTQ+ e le relazioni con altri soggetti bi si mostrano come i contesti relazionali più favorevoli al benessere delle persone rispondenti, mentre il contesto familiare e la rappresentazione mediatica vengono riportati quali elementi di maggiore ostacolo. Fra gli elementi a favore di vissuti positivi emergono la possibilità di avere accesso a materiale informativo e/o a testimonianze di soggetti bisessuali e il vivere in contesti relazionali aperti e plurali. Fra gli aspetti più critici, invece, quelli legati alla scarsa (o superficiale) conoscenza sul tema, che alimenta bi-cancellazione e discriminazione. L’indagine pone in evidenza la necessità di informazione e formazione specifica nell’ambito dell’educazione degli adulti, l’urgenza di favorire contesti in cui il pensiero favorisca la decostruzione di stereotipi e pregiudizi e l’esigenza di un’educazione all’affettività, alla sessualità e alle tematiche LGBTQ+ che aiuti a costruire una nuova cultura della sessualità

Hyperspectral imaging of the microscale distribution and dynamics of microphytobenthos in intertidal sediments

We describe a novel, field-deployable hyperspectral imaging system, called Hypersub, that allows noninvasive in situ mapping of the microphytobenthos (MPB) biomass distribution with a high spatial (sub-millimeter) and temporal (minutes) resolution over areas of 1 x 1 m. The biomass is derived from a log-transformed and near-infrared corrected reflectance hyperspectral index, which exhibits a linear relationship (R-2 > 0.97) with the chlorophyll a (Ch1 a) concentration in the euphotic zone of the sediment and depends on the sediment grain size. Deployments of the system revealed that due to factors such as sediment topography, bioturbation, and grazing, the distribution of MPB in intertidal sediments is remarkably heterogeneous, with Ch1 a concentrations varying laterally by up to 400% of the average value over a distance of 1 cm. Furthermore, due to tidal cycling and diel light variability, MPB concentrations in the top 1 mm of sediments are very dynamic, changing by 40-80% over a few hours due to vertical migration. We argue that the high-resolution hyperspectral imaging method overcomes the inadequate resolution of traditional methods based on sedimentary Ch1 a extraction, and thus helps improve our understanding of the processes that control benthic primary production in coastal sediments

Dominantes pathologiques chez les caprins du Nord Marocain: cas de la région de Tétouan

Dans le but de caractériser les dominantes pathologiques des caprins dans la province de Tetouan, un suivi clinique a porté sur 13 élevages caprins de décembre 1993 à mai 1994. En plus, une étude lésionnelle macroscopique et microscopique a été réalisée sur 400 carcasses de caprins au niveau de 2 abattoirs ruraux. La fréquence de mortalité moyenne dans les élevages suivis était de 22,4% et la mortalité a touché plus les chevreaux de moins d’un mois d’âge (82,5%). Les fréquences d’avortements variaient de 5,3% à 13.3% avec une fréquence moyenne de 7,2% et affectaient beaucoup plus les chèvres primipares (60%). Les diarrhées des chevreaux ont été notées dans 38% des élevages avec une fréquence moyenne de morbidité de 22,4% et elles étaient responsables de 45% des mortalités des chevreaux. La phtiriose a été observée dans 100% des élevages avec une fréquence moyenne de morbidité de 13%. Les abcès ganglionnaires (lymphadénite caséeuse) ont été observés dans 38% des élevages. Sur les carcasses examinées à l’abattage, les broncho-pneumonies vermineuses étaient les plus fréquentes (49%) suivies des kystes hydatiques pulmonaires et/ou hépatiques (9%), des hépato-cholangites (7%) et la cysticercose hépato-péritonéale (6%). D’autres lésions comme l’ictère, l’adénomatose et la lymphdénite caséeuse ont été relevées mais avec une fréquence moindre. Au total 160 poumons (80% des organes porteurs de lésions) et 30 foies (55%) ont été saisis totalement contre 41 poumons (20%) et 22 foies (45%) saisis partiellement. Ces résultats montrent l’importance des pertes économiques dues aux problèmes pathologiques que subit l’élevage caprin de la région de Tétouan en l’absence de toute intervention technique

Spread of imipenem-resistant Acinetobacter baumannii co-expressing OXA-23 and GES-11 carbapenemases in Lebanon

© 2015 The Authors. Objectives: The acquisition of carbapenemases by Acinetobacter baumannii is reported increasingly worldwide, but data from Lebanon are limited. The aims of this study were to evaluate the prevalence of imipenem-resistant A. baumannii in Lebanon, identify resistance determinants, and detect clonal relatedness. Methods: Imipenem-resistant A. baumannii were collected from nine Lebanese hospitals during 2012. Antimicrobial susceptibility, the cloxacillin effect, and ethylenediaminetetraacetic acid (EDTA) synergy were determined. Genes encoding carbapenemases and insertion sequence IS. Aba1 were screened via PCR sequencing. IS. Aba1 position relative to genes encoding Acinetobacter-derived cephalosporinases (ADCs) and OXA-23 was studied by PCR mapping. Clonal linkage was examined by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Results: Out of 724 A. baumannii isolated in 2012, 638 (88%) were imipenem-resistant. Of these, 142 were analyzed. Clavulanic acid-imipenem synergy suggested carbapenem-hydrolyzing extended-spectrum β-lactamase. A positive cloxacillin test indicated ADCs, while EDTA detection strips were negative. Genotyping indicated that 90% of isolates co-harbored blaOXA-23 and blaGES-11. The remaining strains had blaOXA-23, blaOXA-24, blaGES-11, or blaOXA-24 with blaGES-11. ISAba1 was located upstream of blaADC and blaOXA-23 in 97% and 100% of isolates, respectively. ERIC-PCR fingerprinting revealed 18 pulsotypes spread via horizontal gene transfer and clonal dissemination. Conclusion: This survey established baseline evidence of OXA-23 and GES-11-producing A. baumannii in Lebanon, indicating the need for further surveillance