2,091 research outputs found
IPv6 mobility support for real-time multimedia communications: A survey
Mobile Internet protocol version 6(MIPv6) route optimization improves triangular routing problem that exists in MIPv4 environment.Route optimization of Session Initiation Protocol (SIP) over MIPv6 provides ef�cient real-time multimedia applications to users. This article provides a survey of SIP over MIPv6. We review the processes involved during the setting up of a SIP call and during mid-call SIP mobility. When SIP transmits real-time multimedia applications in a wireless environment, the mobile node (MN) may move from one access router (AR) to
another AR, handing over control from one AR to the other. High handover latency degrades the quality of real-time multimedia applications due to the fact that real-time multimedia applications are delay-sensitive.Handover latency is an important issue to discuss.Reduction of handover latency can be made possible with the use of SIP's hierarchical registration. On the other hand, hybrid hierarchical and fast handover SIP's registration performs better compared to hierarchical registration. Finally, we present the directions for future research
The Impact of Central American Free Trade Area (CAFTA) on the United States sugar market
This paper tries to estimate the impact of establishment of CAFTA on the United States sugar market. We use the United States sugar demand elasticity and the amount of increase in the U.S. sugar import quota under CAFTA agreement to estimate the magnitude of this effect. This study shows that these increased imports will result in a decrease in the U.S. domestic sugar price of about 1.7 cents, or approximately 8.6 percent. Although it amounts to only pennies per pound, this decrease in the domestic price could result in the incursion of significant U.S. government expenditures given the current structure of the U.S. non-recourse loan program.International Relations/Trade,
A survey of IPv6 mobility management in real-time communications
The number of mobile wireless Internet users is expected to increase in recent years. Consequently, the 32-bit addressing spaces used for mobile Internet protocol version 4(IPv4) is expected to be used up in the near future. Previous works show that mobile LPv4 causes unnecessary load to the mobile Internet. This unnecessary load increases handover latency. In this paper, we firstly discuss the hybrid Internet protocol version 6 (IPv6) mobility management. Hybrid IPv6 mobility management is the combination of fast handover and hierarchical IPv6 mobility managements. We propose the Session Initiation Protocol (SIP) over hybrid IPv6 mobility management to manage the handover process between inter-domain networks. We also propose cellular hybrid IPv6 mobility management to manage the handover process within intra-domain network. We believe that the proposed SIP over hybrid and cellular hybrid IPv6 mobility managements can solve the problem of unnecessary load and decrease the handover latency
Interworking of protokol in IPv6 mobility management
During communication between wireless users,disconnection may occur during the handover process. The high handover latency during the process of handover degrades the service quality of the wireless communications. This problem becomes more crucial if the operation network is transmitting real-time multimedia applications. This paper presents our work on the interworking of protocols in IPv6 mobility management which aims to explore the means to reduce the handover latency. We propose SIP over IPv6 mobility management with hybrid mechanism which we believe has the possibility to reduce the handover latency. The newly proposed protocol is developed and compared with the existing protocols. The result of the simulation experiment shows that our proposed protocol performs better compared to other protocols
American Society of Anesthesiologists Physical Status Classification System: History, Development, Reliability, and Its Future
The American Society of Anesthesiologists Physical Status (ASA PS) classification has long been used as a ranking system that quantifies patient health before anaesthesia and surgery. When initially developed, the ASA PS intended application was purely statistical. However, nowadays it is commonly used by surgical specialties to determine a patient’s likelihood of developing postoperative complications, despite studies reporting scoring method subjectivity and inconsistencies among anaesthesiologists in assigning these scores. Over the years, the ASA PS classifications have undergone many changes and modifications to address its limitations. There are a few points to be discussed if all shortcomings are to be treated and interobserver variability is to be limited
Analysis of farmer’s choices for climate change adaptation practices in South-Western Uganda, 1980–2009
Climate change is a serious threat to the livelihoods of rural communities, particularly in mountainous areas because they are very sensitive to such changes. In this study, we assessed the household determinants to climate change adaptation drawing from a case study of agricultural adaptation in the Mount Rwenzori area of South Western Uganda. The study identified the major adaptation practices that are adopted by farmers to cope with the impacts of climate change and using available on-farm technologies. A total of 143 smallholder farmers were sampled and interviewed using field based questionnaires, field observations, and key informant interviews. Data was cleaned, entered and analysed using SPSS and Stata software for descriptive statistics. Thereafter, a Multinomial logistic regression model was used to assess the drivers of farmers’ choice for adaptation practices, factors influencing the choice of adaptation, and barriers. The major adaptation practices that were identified included; use of different crop varieties, tree planting, soil and water conservation, early and late planting, and furrow irrigation. Discrete choice model results indicated the age of the household head, experience in farming, household size, climate change shocks, land size, use of agricultural inputs, landscape position (location), and crop yield varied significantly (p > 0.05), which influenced farmers’ choice of climate change adaptation practices. The main barriers to adaptation included inadequate information on adaptation methods and financial constraints, leading us to conclude that contextual adaptation practices are more desirable for adoption to farmers. Adapting to climate change needs support from government and other stakeholders, however the implementation is more successful when appropriate and suitable choices are employed
A Virtual Reality Application for the Training of Deminers
As virtual reality (VR) tools continue to improve, more fields are finding ways of implementing the technology to take advantage of training opportunities that reduce costs, alleviate logistical challenges, and more. Where humanitarian deminers must prepare for dangerous work, VR facilitates training that minimizes the danger while giving trainers a level of control over the different conditions of the training and the ability to easily monitor and instruct the user. For this purpose, the American University of Beirut (AUB) and the Beirut Research and Innovation Center (BRIC) developed a VR application for the basic training of deminers, which is called the VR Demining Trainer (VRDT). The first version of the VRDT, presented herein, teaches trainees how to turn on a metal detector, test the detector, conduct soil compensation, and start searching in a virtual minefield. These activities can be done in a closed room, regardless of time of day or weather conditions. Different training scenario attributes—including soil properties, landmine types, and locations—can be easily selected beforehand via software. The VRDT, which is a lab-ready prototype being developed using the Unreal Engine software and the Oculus Quest VR device, is not meant to replace but supplement field training, cutting down on training time and logistics by performing basic training phases in a VR-controlled environment
Improving provision of family planning among pastoralists in Kenya: perspectives from health care providers, community and religious leaders
There exist significant inequities in access to family planning (FP) in Kenya, particularly for nomadic and semi-nomadic pastoralists. Health care providers (HCP), are key in delivering FP services. Community leaders and religious leaders are also key influencers in women’s decisions to use FP. We found limited research exploring the perspectives of both HCPs and these local leaders in this context. We conducted semi-structured interviews with HCPs (n=4) working in facilities in Wajir and Mandera, and community leaders (n=4) and religious leaders (n=4) from the nomadic and semi-nomadic populations the facilities serve. We conducted deductive and inductive thematic analysis. Three overarching themes emerged: perception of FP as a health priority, explanations for low FP use, and recommendations to improve access. Four overlapping sub-themes explained low FP use: desire for large families, tension in FP decision-making, religion and culture, and fears about FP. Providers were from different socio-demographic backgrounds to the communities they served, who faced structural marginalisation from health and other services. Programmes to improve FP access should be delivered alongside interventions targeting the immediate health concerns of pastoralist communities, incorporating structural changes. HCPs that are aware of religious and cultural reasons for non-use, play a key role in improving access
Predicting phenotypes of beef eating quality traits
Introduction: Phenotype predictions of beef eating quality for individual animals could be used to allocate animals to longer and more expensive feeding regimes as they enter the feedlot if they are predicted to have higher eating quality, and to sort carcasses into consumer or market value categories. Phenotype predictions can include genetic effects (breed effects, heterosis and breeding value), predicted from genetic markers, as well as fixed effects such as days aged and carcass weight, hump height, ossification, and hormone growth promotant (HGP) status. Methods: Here we assessed accuracy of phenotype predictions for five eating quality traits (tenderness, juiciness, flavour, overall liking and MQ4) in striploins from 1701 animals from a wide variety of backgrounds, including Bos indicus and Bos taurus breeds, using genotypes and simple fixed effects including days aged and carcass weight. The genetic components were predicted based on 709k single nucleotide polymorphism (SNP) using BayesR model, which assumes some markers may have a moderate to large effect. Fixed effects in the prediction included principal components of the genomic relationship matrix, to account for breed effects, heterosis, days aged and carcass weight. Results and Discussion: A model which allowed breed effects to be captured in the SNP effects (e.g., not explicitly fitting these effects) tended to have slightly higher accuracies (0.43-0.50) compared to when these effects were explicitly fitted as fixed effects (0.42-0.49), perhaps because breed effects when explicitly fitted were estimated with more error than when incorporated into the (random) SNP effects. Adding estimates of effects of days aged and carcass weight did not increase the accuracy of phenotype predictions in this particular analysis. The accuracy of phenotype prediction for beef eating quality traits was sufficiently high that such predictions could be useful in predicting eating quality from DNA samples taken from an animal/carcass as it enters the processing plant, to enable optimal supply chain value extraction by sorting product into markets with different quality. The BayesR predictions identified several novel genes potentially associated with beef eating quality
Preoperative endoscopic biliary drainage by metal versus plastic stents for resectable perihilar cholangiocarcinoma
Background and Aims: Adequate preoperative biliary drainage (PBD) is recommended in most patients with resectable perihilar cholangiocarcinoma (pCCA). Most expert centers use endoscopic plastic stents rather than self-expandable metal stents (SEMSs). In the palliative setting, however, use of SEMSs has shown longer patency and superior survival. The aim of this retrospective study was to compare stent dysfunction of SEMSs versus plastic stents for PBD in resectable pCCA patients. Methods:In this multicenter international retrospective cohort study, patients with potentially resectable pCCAs who underwent initial endoscopic PBD from 2010 to 2020 were included. Stent failure was a composite end point of cholangitis or reintervention due to adverse events or insufficient PBD. Other adverse events, surgical outcomes, and survival were recorded. Propensity score matching (PSM) was performed on several baseline characteristics. Results: A total of 474 patients had successful stent placement, of whom 61 received SEMSs and 413 plastic stents. PSM (1:1) resulted in 2 groups of 59 patients each. Stent failure occurred significantly less in the SEMSs group (31% vs 64%; P < .001). Besides less cholangitis after SEMSs placement (15% vs 31%; P = .012), other PBD-related adverse events did not differ. The number of patients undergoing surgical resection was not significantly different (46% vs 49%; P = .71). Complete intraoperative SEMSs removal was successful and without adverse events in all patients. Conclusions: Stent failure was lower in patients with SEMSs as PBD compared with plastic stents in patients with resectable pCCA. Removal during surgery was quite feasible. Surgical outcomes were similar.</p
- …