Spatial Monopoly Pricing in a Stochastic Environment

This paper reexamines the welfare implications of three pricing regimes (mill, uniform and discriminatory) for a monopoly in a stochastic environment. It con-siders a risk-averse monopolist faces two markets with stochastic and linear demands. The monopolist is assumed to commit to an irreversible price in each market before the uncertainty is resolved. Several unconventional results are shown to be triggered by the presence of demand uncertainty. The reason for the reversal of orthodox intuition is the asymmetry in the risk chacteristics of the markets and the willingness of the monopolist to trade increased level of expected prots for reduced risk.spatial pricing, monopoly, demand uncertainty

Session-based Recommendation with Graph Neural Networks

The problem of session-based recommendation aims to predict user actions based on anonymous sessions. Previous methods model a session as a sequence and estimate user representations besides item representations to make recommendations. Though achieved promising results, they are insufficient to obtain accurate user vectors in sessions and neglect complex transitions of items. To obtain accurate item embedding and take complex transitions of items into account, we propose a novel method, i.e. Session-based Recommendation with Graph Neural Networks, SR-GNN for brevity. In the proposed method, session sequences are modeled as graph-structured data. Based on the session graph, GNN can capture complex transitions of items, which are difficult to be revealed by previous conventional sequential methods. Each session is then represented as the composition of the global preference and the current interest of that session using an attention network. Extensive experiments conducted on two real datasets show that SR-GNN evidently outperforms the state-of-the-art session-based recommendation methods consistently.Comment: 9 pages, 4 figures, accepted by AAAI Conference on Artificial Intelligence (AAAI-19

Study of Influence on Cohesive Deposits Incipient Motion and Erosion by Dry Bulk Density

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

A REVIEW STUDY ON TRAMADOL ABUSE AMONG EGYPTIAN UNIVERSITY STUDENTS

Tramadol, which is a medication used for moderate and severe pains, has caused drug abuse and addiction to the Egyptian community. This study aimed to observe the prevalence of tramadol abuse among Egyptian university students. By following the PRISMA reporting guideline, a systematic review of evidence was conducted. Search strategy was conducted through PubMed-NCBI to yield appropriate published literature between 2014-2019, as well as performed literature screening, eligibility criteria, and data extraction. The process of selection yielded a total number of 2 studies to be eligible for the review inclusion criteria. The characteristics evaluated that correlate to tramadol were classified into four groups: gender, smoking, alcohol consumption, and failure in exams before. In general, tramadol showed positively associated with other prevalence characteristics. Tramadol is the second most commonly abused drug among university students in Egypt. The review highlights that tramadol abuse has become a common phenomenon among Egyptian university students which necessitates for ample attention. Future research is recommended to identify the causal effects of tramadol abuse and its role as a potential gateway drug.                          Peer Review History: Received 2 January 2020;   Revised 22 February; Accepted 1 March, Available online 15 March 2020 Academic Editor: Dr. Amany Mohamed Alboghdadly, Princess Nourah bint abdulrahman university, Riyadh, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Hebatallaha A  Moustafa, Ain Shams University, Egypt, [email protected] Prof. Dr. Hassan A.H. Al-Shamahy, Sana'a University, Yemen, [email protected] Dr. Ali Abdullah Al-yahawi, Al-Razi university, Department of Pharmacy, Yemen, [email protected] Similar Articles: A CROSS-SECTIONAL STUDY ON BENZODIAZIPINE (BZD) ABUSERS OF DHAKA CITY: A SOCIO-PSYCHOLOGICAL CONDITION OF BANGLADESH AWARENESS AMONGST YOUTH ABOUT USE AND ABUSE OF STEROIDS IN KARACHI, PAKISTAN ALCOHOL INFLUENCES AGGRESSIVE BEHAVIOUR THAT INCREASES LIKELIHOOD OF INITIATING DATING VIOLENCE AMONG MALE YOUTH IN COLLEGES WITHIN WESTERN COUNTRIES: A SCOPING REVIE

Water, rather than temperature, dominantly impacts how soil fauna affect dissolved carbon and nitrogen release from fresh litter during early litter decomposition

Longstanding observations suggest that dissolved materials are lost from fresh litter through leaching, but the role of soil fauna in controlling this process has been poorly documented. In this study, a litterbag experiment employing litterbags with different mesh sizes (3 mm to permit soil fauna access and 0.04 mm to exclude fauna access) was conducted in three habitats (arid valley, ecotone and subalpine forest) with changes in climate and vegetation types to evaluate the effects of soil fauna on the concentrations of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) during the first year of decomposition. The results showed that the individual density and community abundance of soil fauna greatly varied among these habitats, but Prostigmata, Isotomidae and Oribatida were the dominant soil invertebrates. At the end of the experiment, the mass remaining of foliar litter ranged from 58% for shrub litter to 77% for birch litter, and the DOC and TDN concentrations decreased to 54%-85% and increased to 34%-269%, respectively, when soil fauna were not present. The effects of soil fauna on the concentrations of both DOC and TDN in foliar litter were greater in the subalpine forest (wetter but colder) during the winter and in the arid valley (warmer but drier) during the growing season, and this effect was positively correlated with water content. Moreover, the effects of fauna on DOC and TDN concentrations were greater for high-quality litter and were related to the C/N ratio. These results suggest that water, rather than temperature, dominates how fauna affect the release of dissolved substances from fresh litter