bluuebunny/crossref_metadata_2025 huggingface dataset:
The sociability spectrum: evidence from reciprocal genetic copy number variations
Authors: López-Tobón Alejandro , Trattaro Sebastiano , Testa Giuseppe
Published: June 2020

Sociability entails some of the most complex behaviors processed by the central nervous system. It includes the detection, integration, and interpretation of social cues and elaboration of context-specific responses that are quintessentially species-specific. There is an ever-growing accumulation of molecular associations to autism spectrum disorders (ASD), from causative genes to endophenotypes across multiple functional layers; these however, have rarely been put in context with the opposite manifestation featured in hypersociability syndromes. Genetic copy number variations (CNVs) allow to investigate the relationships between gene dosage and its corresponding phenotypes. In particular, CNVs of the 7q11.23 locus, which manifest diametrically opposite social behaviors, offer a privileged window to look into the molecular substrates underlying the developmental trajectories of the social brain. As by definition sociability is studied in humans postnatally, the developmental fluctuations causing social impairments have thus far remained a black box. Here, we review key evidence of molecular players involved at both ends of the sociability spectrum, focusing on genetic and functional associations of neuroendocrine regulators and synaptic transmission pathways. We then proceed to propose the existence of a molecular axis centered around the paradigmatic dosage imbalances at the 7q11.23 locus, regulating networks responsible for the development of social behavior in humans and highlight the key role that neurodevelopmental models from reprogrammed pluripotent cells will play for its understanding.
Surgical debridement of corneal shield ulcers in pediatric patients: two case reports and a review of the literature
Authors: Stock Ricardo Alexandre , Lazzari Silvia Letícia Teixeira , Martins Isadora Proner , Bonamigo Elcio Luiz
Published: June 2020

Background

Ocular allergy is a common disease, especially in the pediatric population, with unpleasant and long-term consequences, including corneal complications and decreased visual acuity. This study reports two cases of corneal shield ulcer due to vernal keratoconjunctivitis, with good results of surgical debridement performed after failure of long-term clinical treatment. Furthermore, this study highlights that this therapeutic approach, although less common, is efficient in treating refractory cases that cause suffering in pediatric patients.

Case presentation

The first patient was a 7-year-old Caucasian boy with chronic ocular allergy, especially photophobia, who had been treated with eye drops, antihistamine, and corticosteroids for 60 days without success. Biomicroscopy of the right eye showed the presence of gelatinous limbus, giant papillae in the tarsal conjunctiva, and a shield ulcer measuring 6.0 mm vertically and 2.7 mm horizontally. Surgical debridement was performed, and the ulcer did not recur. The second patient was a 4-year-old Caucasian boy with chronic ocular allergy, especially itching and photophobia, who had been treated with eye drops for 1 year without success. Biomicroscopy of the left eye showed a shield ulcer, with a dense central corneal plaque, measuring 8 mm vertically and 3.5 mm horizontally. Surgical debridement of the ulcer was performed immediately because of the chronicity of the case and severity of the lesion, and the treatment was effective.

Conclusions

The treatment of shield ulcers caused by vernal keratoconjunctivitis in the two reported cases was curative and definitive by surgical debridement in the 7-month follow-up period. Therefore, the early debridement of shield ulcers refractory to drug treatment can considerably reduce the time of disease evolution and the probability of ocular complications caused by clinical treatment or disease chronicity. However, this approach is rarely described in the literature and needs to be included in the ophthalmologist’s therapeutic arsenal.
Antioxidant preconditioning improves therapeutic outcomes of adipose tissue-derived mesenchymal stem cells through enhancing intrahepatic engraftment efficiency in a mouse liver fibrosis model
Authors: Liao Naishun , Shi Yingjun , Wang Yingchao , Liao Fangyu , Zhao Bixing , Zheng Youshi , Zeng Yongyi , Liu Xiaolong , Liu Jingfeng
Published: June 2020

Background

Although it has been preclinically suggested that adipose tissue-derived mesenchymal stem cell (ADSC)-based therapy could effectively treat chronic liver diseases, the hepatic engraftment of ADSCs is still extremely low, which severely limits their long-term efficacy for chronic liver diseases. This study was designed to investigate the impact of antioxidant preconditioning on hepatic engraftment efficiency and therapeutic outcomes of ADSC transplantation in liver fibrotic mice.

Methods

Liver fibrosis model was established by using intraperitoneal injection of carbon tetrachloride (CCl4) in the male C57BL/6 mice. Subsequently, the ADSCs with or without antioxidant pretreatment (including melatonin and reduced glutathione (GSH)) were administrated into fibrotic mice via tail vein injection. Afterwards, the ADSC transplantation efficiency was analyzed by ex vivo imaging, and the liver functions were assessed by biochemical analysis and histopathological examination, respectively. Additionally, a typical hydrogen peroxide (H2O2)-induced cell injury model was applied to mimic the cell oxidative injury to further investigate the protective effects of antioxidant preconditioning on cell migration, proliferation, and apoptosis of ADSCs.

Results

Our data showed that antioxidant preconditioning could enhance the therapeutic effects of ADSCs on liver function recovery by reducing the level of AST, ALT, and TBIL, as well as the content of hepatic hydroxyproline and fibrotic area in liver tissues. Particularly, we also found that antioxidant preconditioning could enhance hepatic engraftment efficiency of ADSCs in liver fibrosis model through inhibiting oxidative injury.

Conclusions

Antioxidant preconditioning could effectively improve therapeutic effects of ADSC transplantation for liver fibrosis through enhancing intrahepatic engraftment efficiency by reducing oxidative injuries. These findings might provide a practical strategy for enhancing ADSC transplantation and therapeutic efficiency.
A video coverless information hiding algorithm based on semantic segmentation
Authors: Pan Nan , Qin Jiaohua , Tan Yun , Xiang Xuyu , Hou Guimin
Published: June 2020

Due to the fact that coverless information hiding can effectively resist the detection of steganalysis tools, it has attracted more attention in the field of information hiding. At present, most coverless information hiding schemes select text and image as transmission carriers, while there are few studies on emerging popular media such as video, which has more abundant contents. Taking the natural video as the carrier is more secure and can avoid the attention of attackers. In this paper, we propose a coverless video steganography algorithm based on semantic segmentation. Specifically, to establish the mapping relationship between secret information and video files effectively, this paper introduces the deep learning based on semantic segmentation network to calculate the statistical histogram of semantic information. To quickly index the sender’s secret message to the corresponding video frame, we build a three-digit index structure. The receiver can extract the valid video frame from the three-digit index information and restore the secret information. On the one hand, the neural network is trained through the original image and the noisy image in this scheme; therefore, it can not only effectively resist the interference of noises, but also accurately extract the robust deep features of the image. The frames of video generate the robust mapping to the secret information after the semantic information statistics. On the other hand, semantic segmentation belongs to pixel-level segmentation, which has high requirements for network parameters, so it is difficult for attackers to decrypt and recover secret information. Since this scheme does not modify the primitiveness of video data, it can effectively resist steganalysis tools. The experimental results and analysis show that the video coverless information hiding scheme has a large capacity and a certain resistance to noise attack.
The weighted discrete dynamic inequalities for 4-convex functions, and its generalization on time scales with constant graininess function
Authors: Baig Hira Ashraf , Ahmad Naveed
Published: June 2020

Motivated by Pečarić et al. in (J. Math. Inequal. 11(2):543–5502017), we established here weighted discrete dynamic inequalities for the difference of second divided difference of 4-convex functions. Further we extend and unify the two inequalities, by establishing the theory ofn-convexity on time scales having constant graininess function.
Evaluation for hypocenter estimation error in the southwestern Kuril trench using Japan and Russia joint seismic data
Authors: Ichiyanagi Masayoshi , Mikhaylov Valentin , Kostylev Dmitry , Levin Yuri , Takahashi Hiroaki
Published: June 2020

The southwestern Kuril trench is seismically active due to the subduction of the Pacific plate. Great earthquakes in this zone have frequently induced fatal disasters. Seismic monitoring and hypocenter catalogs provide fundamental information on earthquake occurrence and disaster mitigation. Real-time hypocenter and magnitude estimates are extremely crucial data for tsunami warning systems. However, this region is located in the international border zone between Japan and Russia. The Japan Meteorological Agency and Russian Academy of Sciences have routinely determined hypocenters and issued earthquake information independently. Waveform data have not yet been exchanged internationally in real time. Here, we evaluated how a hypothetical Japan–Russia joint seismic network could potentially improve the hypocenter estimation accuracy. Experiments using numerical and observed data indicated that the joint network extended the distance over which hypocenters can be accurately determined over 100 km eastward compared to the Japan network only. This fact suggests that joint seismic data have the potential to improve the hypocenter accuracy in this region, which would provide improved performance in gathering disaster information at the moment of a tsunami warning.
Velocity and diffusion constant of an active particle in a one-dimensional force field
Authors: Le Doussal Pierre , Majumdar Satya N. , Schehr Grégory
Published: June 2020

We consider a run-and-tumble particle with two velocity states

, in an inhomogeneous force field f(x) in one dimension. We obtain exact formulae for its velocity V

L
and diffusion constant D

L
for arbitrary periodic f(x) of period L. They involve the “active potential” which allows to define a global bias. Upon varying parameters, such as an external force F, the dynamics undergoes transitions from non-ergodic trapped states, to various moving states, some with non-analyticities in the V

L
 vs. F curve. A random landscape in the presence of a bias leads, for large L, to anomalous diffusion

,

, or to a phase with a finite velocity that we calculate.
Clathrin regulates Wnt/β-catenin signaling by affecting Golgi to plasma membrane transport of transmembrane proteins
Authors: Munthe Else , Raiborg Camilla , Stenmark Harald , Wenzel Eva Maria
Published: June 2020

The canonical Wnt/β-catenin signaling pathway regulates cell proliferation in development and adult tissue homeostasis. Dysregulated signaling contributes to human diseases, in particular cancer. Growing evidence suggests a role for clathrin and/or endocytosis in the regulation of this pathway, but conflicting results exist and demand a deeper mechanistic understanding. We investigated the consequences of clathrin depletion on Wnt/β-catenin signaling in cell lines and found a pronounced reduction in β-catenin protein levels, which affects the amount of nuclear β-catenin and β-catenin target gene expression. Although we found no evidence that clathrin affects β-catenin levels via endocytosis or multivesicular endosome formation, an inhibition of protein transport through the biosynthetic pathway led to reduced levels of a Wnt co-receptor, low-density lipoprotein receptor-related protein 6 (LRP6), and cell adhesion molecules of the cadherin family, thereby affecting steady-state levels of β-catenin. We conclude that clathrin impacts on Wnt/β-catenin signaling by controlling exocytosis of transmembrane proteins, including cadherins and Wnt co-receptors that together control the membrane-bound and soluble pools of β-catenin.
Synthesis and Chiroptical Properties of †- and ‡-Shaped Molecules Based on Planar Chiral [2.2]Paracyclophane
Authors: Sasai Yusaku , Inoue Ryo , Morisaki Yasuhiro
Published: June 2020

Two types of optically active molecules based on planar chiral 4,7,12,15-tetrasubstituted [2.2]paracyclophane were synthesized through chemoselective Sonogashira-Hagihara coupling. One is a †-shaped molecule consisting of two π-electron systems stacked, and the other is a ‡-shaped molecule consisting of three π-electron systems stacked. Their optical and chiroptical properties were investigated, which exhibited large molar absorption coefficient, excellent photoluminescence quantum efficiency, and intense circularly polarized luminescence (CPL).
A survey of band selection techniques for hyperspectral image classification
Authors: Sawant Shrutika , Prabukumar Manoharan
Published: June 2020

Hyperspectral images usually contain hundreds of contiguous spectral bands, which can precisely discriminate the various spectrally similar classes. However, such high-dimensional data also contain highly correlated and irrelevant information, leading to the curse of dimensionality (also called the Hughes phenomenon). It is necessary to reduce these bands before further analysis, such as land cover classification and target detection. Band selection is an effective way to reduce the size of hyperspectral data and to overcome the curse of the dimensionality problem in ground object classification. Focusing on the classification task, this article provides an extensive and comprehensive survey on band selection techniques describing the categorisation of methods, methodology used, different searching approaches and various technical difficulties, as well as their performances. Our purpose is to highlight the progress attained in band selection techniques for hyperspectral image classification and to identify possible avenues for future work, in order to achieve better performance in real-time operation.
Trends of utilization of Complete Blood Count parameters for patient management among doctors in Azad Kashmir
Authors: Ahmed Malik Mahmood , Ghauri Sanniya  Khan , Javaeed Arslaan , Rafique Nazish , Hussain Wajid , Khan Nasir
Published: June 2020

Objective: To determine the trends of utilization of CBC parameters in patient management among doctors in different hospitals in Kashmir, Pakistan.

Methods: A self-administered questionnaire-based survey was carried out amongst doctors working in four hospitals of Kashmir i.e. Combined Military Hospital, Muzaffarabad, Combined Military Hospital, Rawalakot, Abbas Institute of Medical Sciences, Muzaffarabad, and District Hospital, Kotli during August to December 2017.

Results: Out of 500 physicians, 217 physicians answered the questionnaire, representing a response rate of 43.4%. Only three of the 11 parameters in the CBC report i.e. hemoglobin, white blood cell count and platelets were selected as frequently or always useful by more than 80% of physicians. Rest of the eight parameters of the CBC were found useful by less than 80% of the physicians. Most agreed that the current format of a CBC report gives adequate information.

Conclusion: The present study concludes that majority of the physicians utilize only three of the basic parameters on the complete blood count. An educational intervention can be planned for the physicians to increase their knowledge about the utility of other parameters.

doi: https://doi.org/10.12669/pjms.36.5.1885

How to cite this:Ahmed MM, Ghauri SK, Javaeed A, Rafique N, Hussain W, Khan N. Trends of utilization of Complete Blood Count parameters for patient management among doctors in Azad Kashmir. Pak J Med Sci. 2020;36(5):999-1004. doi: https://doi.org/10.12669/pjms.36.5.1885

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Behcet’s Disease: Pakistani Experience
Authors: Khan Asadullah , Haroon Muhammad , Bashir Farhan , Din Zia ud
Published: June 2020

Objective: To analyze the clinical manifestation of patients with Behcet’s disease, and performance of different classification criteria of Behcet’s disease in our population.

Methods: It was a retrospective analysis of all Behcet’s disease patients attending Department of Rheumatology at Fatima Memorial Hospital, Lahore, Pakistan from April 2019 to July 2019. We performed a comprehensive clinical evaluation of patients with Behcet’s disease, with focus on patients’ age, gender and different clinical manifestations.

Results: A consecutive cohort of 20 patients was studied. All patients met the International Criteria of Behcet’s Disease criteria, and 18 out of 20 patients also met International Study Group criteria. Mean age of the cohort was 33.5±10.4 years and 45% was female (male to female ratio of 1:1.2). Around 90% of cohort had recurrent oral and genital ulcers. Ocular involvement was present in 80% patients, while Joint manifestations were present in 75% of patients. Cutaneous, neurological (both central and peripheral nervous system involvement), and GIT symptoms were present in 50%, 30%, and 15% of patients, consecutively. Joint pain and eye symptoms were major initial symptoms in males, while eye symptoms and neurological symptoms were more common in female patients at disease onset. Reaching border line significance, Cutaneous (p-value=0.479), ocular (p-value=0.61), and GIT involvement (p-value=0.59) were more prevalent in males while neurological involvement (p-value=0.336) in females.

Conclusion: Behcet’s disease occurs commonly in middle age population with equal male to female ratio, with mucocutaneus aphthosis, ocular disease and joint pains being common manifestation. Gastrointestinal symptoms are more common in males while neurological symptoms in females.

doi: https://doi.org/10.12669/pjms.36.5.1916

How to cite this:Khan A, Haroon M, Bashir F, Zia-ud-Din. Behcet’s Disease: Pakistani Experience. Pak J Med Sci. 2020;36(5):1005-1010. doi: https://doi.org/10.12669/pjms.36.5.1916

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Enteric Fever Complicated by Intestinal Perforation in Children: A Persistent Health Problem Requiring Surgical Management
Authors: Azhar Muhammad , Zamir Naima , Shaikh Mishraz , Ullah Inayat
Published: June 2020

Objective: To evaluate clinical presentation and surgical outcome in children with enteric perforation.

Methods: A descriptive retrospective study was conducted in Department of Paediatric Surgery at National Institute of Child Health, Karachi from August 2016 and September 2019, in children 12 years of age and under with diagnosis of enteric perforation. Data about age, gender, duration of illness, hemodynamic status and baseline investigation on admission was reviewed. Details about patients operated early and those who required prolong resuscitation and were operated after 24 hours of admission, need for tube laparostomy, operative findings, type of surgical procedure performed and post-operative outcome were reviewed. Data was analyzed using SPSS version 22.

Results: Ninety-seven patients, 60(61.85%) males and 37(38.14%) females were managed during the study period with age ranged from 3-12 years (mean 7.82, ± 2.94 years).and duration of symptoms ranged from 7-30 days (mean 15.56, ± 9.39days). High grade fever and abdominal pain were seen in all patients (100%). Pneumoperitoneum was noted in 71(73.19%) cases on X-ray abdomen. Fifty-one (52.57%) children were anemic and required blood transfusion before surgery. Seventy-one (73.19) patients were optimized and operated within 24 hours while 28(28.86%) cases required more resuscitation so tube laparostomy was done initially and operated after 24 hours. Seventy nine (81.44%) cases had single perforation, 14(14.43%) cases had multiple and four had sealed perforation. Primary repair of perforation was done in 37(38.14%) cases, while ileostomy in 65(76.01%) cases. Postoperatively wound infection was seen in 71(73.19%) cases, intra-abdominal collections in 31(31.95%) and burst abdomen in nine (9.27%) cases. Overall mortality was 12.37%. Till date in 47 patients (72.30%) reversal of stoma has been done.

Conclusions: Enteric perforation in children presents usually with hemodynamic instability and sepsis due to prolong period of illness. Therefore, regardless of surgical procedure performed it is associated with high morbidity and mortality.

doi: https://doi.org/10.12669/pjms.36.5.2270

How to cite this:Azhar M, Zamir N, Shaikh M, Inayat ullah4. Enteric Fever Complicated by Intestinal Perforation in Children: A Persistent Health Problem Requiring Surgical Management. Pak J Med Sci. 2020;36(5):890-893. doi: https://doi.org/10.12669/pjms.36.5.2270

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Chanjo: Clincal grade sequence coverage analysis
Authors: Andeer Robin , Magnusson Måns , Wedell Anna , Stranneheim Henrik
Published: June 2020

Coverage analysis is essential when analysing massive parallel sequencing (MPS) data. The analysis indicates existence of false negatives or positives in a region of interest or poorly covered genomic regions. There are several tools that have excellent performance when doing coverage analysis on a few samples with predefined regions. However, there is no current tool for collecting samples over a longer period of time for aggregated coverage analysis of multiple samples or sequencing methods. Furthermore, current coverage analysis tools do not generate customized coverage reports or enable exploratory coverage analysis without extensive bioinformatic skill and access to the original alignment files.

We present Chanjo, a user friendly coverage analysis tool for persistent storage of coverage data, that, accompanied with Chanjo Report, produces coverage reports that summarize coverage data for predefined regions in an elegant manner. Chanjo Report can produce both structured coverage reports and dynamic reports tailored to a subset of genomic regions, coverage cut-offs or samples. Chanjo stores data in an SQL database where thousands of samples can be added over time, which allows for aggregate queries to discover problematic regions. Chanjo is well tested, supports whole exome and genome sequencing, and follows common UNIX standards, allowing for easy integration into existing pipelines.

Chanjo is easy to install and operate, and provides a solution for persistent coverage analysis and clinical-grade reporting. It makes it easy to set up a local database and automate the addition of multiple samples and report generation. To our knowledge there is no other tool with matching capabilities. Chanjo handles the common file formats in genetics, such as BED and BAM, and makes it easy to produce PDF coverage reports that are highly valuable for individuals with limited bioinformatic expertise. We believe Chanjo to be a vital tool for clinicians and researchers performing MPS analysis.
Hydraulics. Workshop
Authors: Vol'vak Sergey
Published: June 2020

Study guide corresponds to the program discipline "Hydraulics". Consists of two parts and is for carrying out practical and laboratory works.
The first part provides material on the basics of the calculation of hydraulic machines, hydraulic drives of agricultural machinery, systems of land reclamation and hydraulic transport for development of skills of application of theoretical information to solve specific technical problems and development practices of hydraulic calculations.
The second part contains material for the study of the methods and instruments for measuring pressure, the study of the equation of Bernoulli, determination of hydraulic resistance, the study of the structure and principles of operation of positive displacement pumps and dynamic-type, cylinders, volumetric hydraulic drive and hydrodynamic transmission elements and schemes of irrigation systems and agricultural water supply.
To conduct practical and laboratory classes for students of all forms of training in the direction of training 35.03.06 "Agroengineering", as well as for graduate students, teachers and technical workers of agriculture.
Socio-Psychological Training for Professional Communication of Negotiating Staff
Authors: Vahina V. , Yurenkova V.
Published: June 2020

The problem of formation of socio-psychological competence in the process of professional psychological training is considered. The article considers the essence and functions of social and psychological training of professional communication in the context of forming partnerships with citizens. Psychologically based ways and means of mastering the skills of effective interaction by employees of internal Affairs bodies are revealed.

In order to improve the training process for ATS employees, a new training program has been developed, which should be used with different categories of students in various forms of training: full-time, distance, and interactive. The program is used by students of educational organizations at the initial stage of preparation, in order to improve skills of interpersonal interaction in various legally significant situations. Conducting classes is carried out in person, as a result, the motivation to achieve success increases, confidence increases; social responsibility, in particular, compliance with the law when making a decision. So far, the following have been advocating for the development of employee negotiation competence: readiness to display the knowledge and skills inherent in negotiation competence (value-motivational component); possession of knowledge of the content of negotiation competence (cognitive component); ability to contact and interact with subjects of negotiations (communicative and behavioral components); emotional flax-volitional I regulation in the negotiation process (emotional flax-volitional component).
Study of the Characteristics of the Psychological Culture of the Heads of Territorial Internal Affairs Bodies of the Russian Federation
Authors: Shumilina Irina
Published: June 2020

Psychological culture affects the productivity of personal development, communication of the personality, its social adaptation, is manifested in the characteristics of thinking and attitude to life. The study of the problems of psychological culture is a new direction in psychological science. Questions related to the study of the characteristics of the psychological culture of the leaders of the territorial internal affairs bodies of the Russian Federation have not been studied. The psychological culture of the head of the internal affairs bodies of the Russian Federation acts as a psychological characteristic of a person, which allows providing optimal conditions for the successful implementation of leadership functions. In the framework of empirical studies of psychological culture, one-sidedness of their orientation is ascertained. Empirical studies of the characteristics of the psychological culture of the heads of territorial internal affairs bodies of the Russian Federation have not been conducted. To study the characteristics of the psychological culture of the leaders of the territorial internal affairs bodies of the Russian Federation, the Methodology “Psychological Culture of Personality” was used by O.I. Motkova. The empirical study involved 100 respondents - heads of territorial internal affairs bodies of the Russian Federation. Based on the results of an empirical study, it was concluded that the leaders of the territorial internal affairs bodies of the Russian Federation need specially organized measures to develop a psychological culture on the part of departmental psychologists, especially at the beginning of their service as a leader, which will certainly contribute the success of their professional activities.
Family Representations of Primary Schoolchildren from Single-Parent and Complete Families
Authors: Golubeva Elena
Published: June 2020

The article provides a theoretical analysis of the problem of influence of the factor "complete / single-parent family" on intellectual and personal development of a child. It is noted that a family with a changed structure leaves an imprint on the child’s perception of a family and can affect his / her own family and parental attitudes in the future, which determines the relevance of this study. Differences in family representations among primary school children from complete and single-parent families have been empirically revealed. The number of associations on the theme of “family” is greater in children from complete families (but it falls during primary school age) than in children from incomplete (but it increases during primary school age). The qualitative characteristics of representations also have differences: in children from complete families, they primarily encompass family members, and in children from incomplete families – relations between them. The author comes to the conclusion that primary schoolchildren's ideas about the family can serve as an indicator of the family situation in which the child is growing, which is of interest, from a practical point of view as well.
Competition and Pay Inequality Within and Between Firms
Authors: Gartenberg Claudine , Wulf Julie
Published: June 2020

How does market competition affect pay inequality between and within firms? Using division managers as a pool of similar workers and the Canada–U.S. Free Trade Agreement, we find that greater competition increases overall pay inequality between, but not within, firms. This null effect within firms is not driven by a lack of statistical power. Instead, we find that it arises primarily within subsamples of firms with higher predicted levels of social comparison. Increased competition leads to greater pay-performance sensitivity among the higher-paid managers within firms, while it leads to greater overpayment among the other managers. These patterns are consistent with firm principals offering higher-powered incentives to their best managers and overpaying the rest. Altogether, this study suggests that, while competition leads to greater pay inequality overall, principals aim to maintain equality within firms and do so through the differential provision of incentives among employees.

This paper was accepted by Bruno Cassiman, business strategy.
Location of Charging Stations in Electric Car Sharing Systems
Authors: Brandstätter Georg , Leitner Markus , Ljubić Ivana
Published: June 2020

Electric vehicles are prime candidates for use within urban car sharing systems, both from economic and environmental perspectives. However, their relatively short range necessitates frequent and rather time-consuming recharging throughout the day. Thus, charging stations must be built throughout the system’s operational area where cars can be charged between uses. In this work, we introduce and study an optimization problem that models the task of finding optimal locations and sizes for charging stations, using the number of expected trips that can be accepted (or their resulting revenue) as a gauge of quality. Integer linear programming formulations and construction heuristics are introduced, and the resulting algorithms are tested on grid-graph-based instances, as well as on real-world instances from Vienna. The results of our computational study show that the best-performing exact algorithm solves most of the benchmark instances to optimality and usually provides small optimality gaps for the remaining ones, whereas our heuristics provide high-quality solutions very quickly. Our algorithms also provide better solutions than a sequential approach that considers strategic and operational decisions separately. A cross-validation study analyzes the algorithms’ performance in cases where demand is uncertain and shows the advantage of combining individual solutions into a single consensus solution, and a simulation study investigates their behavior in car sharing systems that provide their customers with more flexibility regarding vehicle selection.
Distributionally Robust Hub Location
Authors: Wang Shuming , Chen Zhi , Liu Tianqi
Published: June 2020

We study the adaptive distributionally robust hub location problem with multiple commodities under demand and cost uncertainty in both uncapacitated and capacitated cases. The hub location decision anticipates the worst-case expected cost over an ambiguity set of possible distributions of the uncertain demand and cost, and the routing policy, being adaptive to the uncertainty realization, ships commodities through selected hubs. We investigate the adaptivity and tractability of the distributionally robust model under different distributional information about uncertainty. In the uncapacitated case in which demand and cost are independent and costs of different commodities are also mutually independent, the adaptive distributionally robust model is equivalent to a nonadaptive classical robust model and the second-stage routing decision follows an optimal static policy. We then relax the independence assumption and show that the second-stage routing decision follows an optimal scenario-wise policy if either the demand or the cost is supported on a convex hull of given scenarios. We extend our analysis to the capacitated case and show that the second-stage routing decision still follows an optimal scenario-wise policy if the demand is supported on the convex hull of given scenarios. In terms of tractability, for all mentioned cases, we reformulate the distributionally robust model as a moderate-sized mixed-integer linear program, and we recover the associated worst-case distribution by solving a collection of linear programs. Through numerical studies using the Civil Aeronautics Board data set, we demonstrate the advantages of the distributionally robust model by examining its superior out-of-sample performance against the classical robust model and the stochastic model.
ISSUES AND CHALLENGES IN ASSESSING ECOLOGICAL AND HUMAN HEALTH RISK FROM THE SITING OF SMRS IN CANADA
Authors: Rowan David
Published: June 2020

There are many issues and challenges in assessing ecological and human health risk from siting small modular reactors (SMRs) in northern or Arctic regions. Environmental guidance for Canadian nuclear facilities is largely derived from data and models relevant to temperate regions, with no explicit guidance or parameters for northern regions. International Atomic Energy Agency guidance provides some data and parameters for northern regions, but there remains a paucity of data and models. Although wildlife often comprise a major part of northern and Arctic diets, there are few data or transfer parameters for these ecosystems. Data and transport models are available for weapon test and Sellafield/La Hague fission products in northern oceans, but very little is known about circulation or fate and transport in estuarine and coastal areas typical of northern Canada. Baseline data, parameters, and models are needed for key processes and pathways to accurately assess ecological and human health risk.
Independent living for all: renewing social care through a rights-based approach
Authors: Slasberg Colin , Beresford Peter
Published: June 2020

The 1948 welfare state settlement perpetuated social care as stuck in the Poor Law. However, its capacity to deliver short-term political expedients has allowed it to remain in place and defy decades of efforts to reform it, creating an intellectual and moral desert. The concept of independent living developed by the disabled people’s movement could fill the vacuum and become the driving vision for a sustainable system of social care based on rights. This would require the dismantling of the pernicious eligibility system to be replaced by one based on claimable legal rights. The article sets out a route to achieve this, beginning by making the recording of need a reality. This in itself would have a transformative impact on how the system works, creating pressure for change by highlighting political responsibility.
Modal control of thermoplasmonic behavior of nanostructures based on excitation of perfect absorption resonances
Authors: Yazdanfar Payam , Heydarian Hesam , Rashidian Bizhan
Published: June 2020

Controlling the localized heat generation density and temperature profile of nanostructures exploiting perfect absorption of individual resonance modes is reported. The methodology is applied to spherically symmetric nanostructures using the T-matrix method. It is demonstrated that perfect modal splitting of the absorption power at desired wavelengths and individual excitation of the modes provide the ability to localize the generated heat at desired locations, and control the resulting temperature profile in multilayer core–shell structures. By knowing the thermal behavior of individual modes, it is shown that excitation of the perfect absorption modes at desired temperatures can result in compensation for the temperature-rise drop, induced in high-temperature thermoplasmonics due to thermal shift of the resonance frequencies. Much higher temperature rises can be achieved through properly designed thermal mode-coupling schemes. The proposed methodology is very promising for the control of the thermoplasmonic behavior of nanostructures, and the design of much more thermally efficient structures, taking into account the thermally dependent parameters.
Self-biasing of carrier depletion based silicon microring modulators
Authors: Melikyan Argishti , Kim Kwangwoong , Stern Brian , Kaneda Noriaki
Published: June 2020

We report on the self-biasing effect of carrier depletion based silicon microring modulators (MRM) by demonstrating that a silicon MRM can generate open eye diagrams for non-return-to-zero (NRZ) on-off keying (OOK) modulation without an external reverse bias supplied to it. Two modulator configurations are investigated namely single-ended drive in a ground-signal-ground and differential drive in a ground-signal-signal-ground pad configurations. The single-ended modulator is designed with an on photonic integrated circuit (PIC) 50 Ω termination. Open eye diagrams are obtained at 25 Gbit/s and 36 Gbit/s NRZ OOK modulations. We carry-out thorough experimental characterization of the self-biasing of single-ended MRM under various operating conditions of input optical power, carrier wavelength, ring quality factor and extinction ratio as well as modulation speeds, driving voltage swing and pattern length. We demonstrate that the self-biasing is robust and works well in almost all tested conditions. The differential drive MRM is designed with a high impedance without an on-PIC 50 Ω termination. Open eye diagrams are obtained at 30 Gbit/s and 60 Gbit/s NRZ OOK modulations for modulating voltage swing of ∼2.5 Vpp. As demonstrated, the self-biasing works well in both single-ended and differential drive configurations as well as for on-PIC 50 Ω terminated and non-terminated MRMs. The electrical passive parts are all co-designed and fabricated on the same silicon chip as the PIC. The reported self-biasing eliminates the need of having bipolar DC biases supplied to the anode and cathode of the differential drive modulator and allows for simpler driver / modulator interfaces without inductive bias tees.
Blind and low-complexity modulation format identification scheme using principal component analysis of Stokes parameters for elastic optical networks
Authors: Xu Hengying , Yang Lishan , Yu Xinkuo , Zheng Zibo , Bai Chenglin , Sun Weibin , Zhang Xiaoguang
Published: June 2020

We propose a blind and low-complexity modulation format identification (MFI) scheme for elastic optical networks (EONs). Since the square operation reduces half the number of the clusters in Stokes space, the scheme directly performs principal component analysis (PCA) on Stokes parameters after square operation. This greatly reduces the dimensionality of received signals from 3 × N to 3 × 3. Subsequently, three obtained principal components (PCs) are employed synthetically to identify the modulation formats. The effectiveness is first verified through 28 GBaud polarization division multiplexing (PDM)-BPSK/-QPSK/-8QAM/-16QAM/-32QAM/-64QAM simulation systems. Only using 2048 symbols, the required minimum optical signal-to-noise ratio (OSNR) values to achieve 100% MFI success rate are all equal to or lower than their corresponding 7% forward error correction (FEC) thresholds. Besides that, the scheme also obtains significant tolerances to residual chromatic dispersion (CD) and differential group delay (DGD). Finally, the proposed scheme is further verified by 20 GBaud PDM-QPSK/-16QAM/-32QAM long-haul transmission experiments. The results demonstrate that the scheme exhibits good resilience towards fiber nonlinear impairments. More importantly, compared with other four kinds of MFI schemes, the used symbol number to achieve 100% MFI success rate notably equals to at most 2/5 as that of other schemes, and its time complexity can be reduced to O(N).
Plasmonic analogue of geometric diodes realizing asymmetric optical transmission
Authors: Zheng Ze , Elkabbash Mohamed , Zhang Jihua , Guo Chunlei
Published: June 2020

Geometric diodes represent a relatively new class of diodes used in rectennas that rely on the asymmetry of a conducting thin film. Here, we numerically investigate a plasmonic analogue of geometric diodes to realize nanoscale optical asymmetric transmission. The device operates based on spatial symmetry breaking that relies on a unique property of surface plasmon polaritons (SPPs), namely, adiabatic nanofocusing. We show that the structure can realize on-chip asymmetric electromagnetic transmission with a total dimension of

∼

2

µ

m

×

6

µ

m

. We demonstrate a signal contrast of 0.7 and an asymmetric optical transmission ratio of 4.77 dB. We investigate the origin of the asymmetric transmission and show that it is due mainly to asymmetric out-coupling of SPPs to far-field photons. We highlight the role of evanescent field coupling of SPPs in undermining the asymmetric transmission efficiency and show that by adjusting the plasmonic waveguide dimensions, a signal contrast of 0.94 and an asymmetric optical transmission ratio of 5.18 dB can be obtained. Our work presents a new paradigm for on-chip nanoscale asymmetric optical transmission utilizing the unique properties of SPPs.
Intriguing branching of the maximum position of the absorption cross section in Mie theory explained
Authors: Rasskazov Ilia L. , Carney P. Scott , Moroz Alexander
Published: June 2020

A potential control over the position of maxima of scattering and absorption cross sections can be exploited to better tailor nanoparticles for specific light–matter interaction applications. Here we explain in detail the mechanism of an appreciable blue shift of the absorption cross-section peak relative to a metal spherical particle localized surface plasmon resonance (LSPR) defined as the maximum of the extinction (and scattering) cross section. Such a branching of cross sections’ maxima requires a certain threshold value of size parameter (

x
≈
0.7

for dipole channel) and is a prerequisite for obtaining high fluorescence enhancements, because the spectral region of high radiative rate enhancement becomes separated from the spectral region of high non-radiative rate enhancement. A consequence is that the maximum of the absorption cross section cannot be used as the definition of the LSPR position for

x
≳
0.7

.
From Early to Divine
Authors: Fathy Ehud
Published: June 2020

The asàrotos òikos or “unswept floor” is a decorative theme found in Roman mosaics. The theme depicts scraps of food along other items, as if scattered across the room’s floor. According to Pliny the theme was first created by Sosus in Pergamon. The mosaic Pliny is referring to was never discovered; however, later Roman variations on this theme were discovered in both Italy and Tunisia. This article seeks to examine the changes made to the asàrotos òikos motif when it transitions from centre to periphery and from the first to the sixth century CE. This article explores the functions and meanings the theme has held in Roman thought during the first and second century CE, the change in perception and use of the theme during the third century in the provincial Roman towns of North Africa, the influence of the theme on Early Christian art – both in style and iconography, and the new meanings possibly assigned to the theme upon its later use in a Byzantine basilica.
Detection of Hard Exudates in Retinopathy Images
Authors: Verma Satya Bhushan , Yadav Abhay Kumar
Published: June 2020

The tissue layer located at the back of the eye is known as retina which converts the incoming light into nerve signals and those signals are sent to the brain for understanding. The damage onto the retina is termed as retinopathy and that may lead to vision weakening or vision loss. The hard exudates are small white or yellowish white deposits with their edges being clear and sharp. In the proposed methods we take color image of retina then extract the green channel of that image then apply top hat transformation and bottom hat transformation on that image. The DIARETDB1 and High-Resolution Fundus (HRF) databases are used for performance evaluation of the proposed method. The proposed technique achieves accuracy 97%, sensitivity 95%, and specificity 96% and it takes average 5.6135 second for detection of hard exudates in an image.
Load balancing with Job Migration Algorithm for improving performance on grid computing: Experimental Results
Authors: Wided Ali , Okba Kazar , Fatima Bouakkaz
Published: June 2020

Grid is the collection of geographically distributed computing resources. For efficient management of these resources, the manager must maximize its utilization, which can be achieved by efficient load balancing with Job Migration techniques.Job Migration from overloaded resources to underloaded is an attempt to load balancing across all processors, thus reduce average response time. The decision of migration is based on the information exchange between resources.In this paper, the authors propose a novel Job Migration Algorithm for Dynamic Load Balancing (JMADLB), in which parameters such as CPU load and queue length have been considered and have been used for the selection of overloaded resources (or underloaded ones) in Grid. Here, the overloaded resources do not accept any new job; but, the new jobs are migrated to underloaded resources, even though this mechanism migrate extra jobs to obtain load balancing. The performances of the proposed algorithms were tested in Alea 2 simulator by using different parameters like response time, resources utilization and waiting time in the global queue. In addition, they were compared with other scheduling algorithms such as First Come First Served (FCFS) and Earliest Deadline First (EDF).