80 research outputs found

    The role and standardisation of geographical names on maps : Oman as a case study

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    Geographical namses play prominent roles in various fields in Oman. While working in the National Survey Authority in Oman, the researcher found that there are some problematic issues related to the use and management of geographical names such as lack of databases and the contradiction of geographical names caused by having more than one establishment dealing with geographical names. This study seeks to consider these and contribute to developing the use of the existing geographical names on maps in Oman. The aims are: (1) to investigate best practices for collecting, approving and managing geographical names; (2) to identify the existing policies, procedures and use of geographical names in Oman; and (3) to propose a system for collection, approval and management of geographical names in Oman. The concepts and importance of maps, map history and their relationship with geographical names are discussed. This is in addition to highlighting the importance of geographical names and their functions and roles. The relationship between the proper names and the scale of maps was investigated. The results show that the proper names generally decrease in density in relation to the ground area covered as scale is reduced, but names increase in density on the map with reducing scale. Methods for collecting geographical names are reviewed, followed by a discussion of the methods of recording and storing geographical names. The particular problems that face collecting geographical names in Oman were highlighted. They are the pronunciation of geographical names, the language differendes, the inaccessibility of some areas and the lack of cooperation of local residents in provision of accurate information. The transliteration of geographical names in general and in Oman specifically is investigated with the most prominent problems that face geographical names transliteration in Oman identified. The first problem is the variety of languages and dialects in Oman as a result of Oman's rich history of trade and location which encouraged immigration. Other problems are the qualifications of the geographical names team and the lack of a responsible establishment for geographical names. The standardisation of geographical names and its advantages are discussed, highlighting Oman's case in dealing with geographical namse. From this discussion the importance of having a geographical names committee responsible for geographical names was demonstrated and some examplse of geographical names committees in a range of countries presented. An analysis of the problem of standardisation of geographical names in Oman culminates in a proposal for a geographical names committee in Oman in order to overcome the problems identified. A committee structure is suggested, along with membership and responsibilities. This is followed by recommendations for supporting the proposed committee. For example, unifying geogrpahical names and training all the geographical names team members. Finally, someother recommendations for further studies, such as creating geographical names gazateer and studying geographical namse in the Holy Quran, are suggested

    3D modeling and integration of current and future interconnect technologies

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    Title from PDF of title page viewed June 21, 2021Dissertation advisor: Masud H. ChowdhuryVitaIncludes bibliographical references (pages 133-138)Thesis (Ph.D.)--School of Computing and Engineering and Department of Physics and Astronomy. University of Missouri--Kansas City, 2021To ensure maximum circuit reliability it is very important to estimate the circuit performance and signal integrity in the circuit design phase. A full phase simulation for performance estimation of a large-scale circuit not only require a massive computational resource but also need a lot of time to produce acceptable results. The estimation of performance/signal integrity of sub-nanometer circuits mostly depends on the interconnect capacitance. So, an accurate model for interconnect capacitance can be used in the circuit CAD (computer-aided design) tools for circuit performance estimation before circuit fabrication which reduces the computational resource requirement as well as the time constraints. We propose a new capacitance models for interconnect lines in multilevel interconnect structures by geometrically modeling the electrical flux lines of the interconnect lines. Closed-form equations have been derived analytically for ground and coupling capacitance. First, the capacitance model for a single line is developed, and then the new model is used to derive expressions for the capacitance of a line surrounded by neighboring lines in the same and the adjacent layers above and below. These expressions are simple, and the calculated results are within 10% of Ansys Q3D extracted values. Through silicon via (TSV) is one of the key components of the emerging 3D ICs. However, increasing number of TSVs in smaller silicon area leads to some severe negative impacts on the performance of the 3D IC. Growing signal integrity issues in TSVs is one of the major challenges of 3D integration. In this paper, different materials for the cores of the vias and the interposers are investigated to find the best possible combination that can reduce crosstalk and other losses like return loss and insertion loss in the TSVs. We have explored glass and silicon as interposer materials. The simulation results indicate that glass is the best option as interposer material although silicon interposer has some distinct advantages. For via cores three materials - copper (Cu), tungsten (W) and Cu-W bimetal are considered. From the analysis it can concluded that W would be better for high frequency applications due to lower transmission coefficient. Cu offers higher conductivity, but it has larger thermal expansion coefficient mismatch with silicon. The performance of Cu-W bimetal via would be in between Cu and W. However, W has a thermal expansion coefficient close to silicon. Therefore, bimetal Cu-W based TSV with W as the outer layer would be a suitable option for high frequency 3D IC. Here, we performed the analysis in terms of return loss, transmission coefficient and crosstalk in the vias. Signal speed in current digital systems depends mainly on the delay of interconnects. To overcome this delay problem and keep up with Moore’s law, 3D integrated circuit (vertical integration of multiple dies) with through-silicon via (TSV) has been introduced to ensure much smaller interconnect lengths, and lower delay and power consumption compared to conventional 2D IC technology. Like 2D circuit, the estimation of 3D circuit performance depends on different electrical parameters (capacitance, resistance, inductance) of the TSV. So, accurate modeling of the electrical parameters of the TSV is essential for the design and analysis of 3D ICs. We propose a set of new models to estimate the capacitance, resistance, and inductance of a Cu-filled TSV. The proposed analytical models are derived from the physical shape and the size of the TSV. The modeling approach is comprehensive and includes both the cylindrical and tapered TSVs as well as the bumps. On-chip integration of inductors has always been very challenging. However, for sub- 14nm on-chip applications, large area overhead imposed by the on-chip capacitors and inductors has become a more severe concern. To overcome this issue and ensure power integrity, a novel 3D Through-Silicon-Via (TSV) based inductor design is presented. The proposed TSV based inductor has the potential to achieve both high density and high performance. A new design of a Voltage Controlled Oscillator (VCO) utilizing the TSV based inductor is also presented. The implementation of the VCO is intended to study the feasibility, performance, and real-world application of the proposed TSV based inductor.Introduction -- Background of capacitance modeling of on-chip interconnect -- Accurate modeling of interconnect capacitance in multilevel interconnect structures for sub 22nm technology -- Analysis of different materials and structures for through silicon via and through glass via in 3D integrated circuits -- Impacts of different shapes of through-silicon-via core on 3D IC performance -- Accurate electrical modeling of cu-filled through-silicon-via (TSV) -- Design and characterize TSV based inductor for high frequency voltage-controlled oscillator design -- Conclusion and future wor

    Anaesthetic management of tracheal injury following blunt neck trauma: An unusual late presentation

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    Tracheal injuries, following blunt neck trauma, are life-threatening surgical emergencies with high risk of mortality. A high index of suspicion is necessary to avoid missing an occult injury because delays in diagnosis and definitive treatment are associated with poorer outcomes. We, herein, report a case of a 28-year man who presented in Emergency Department 15 days after blunt neck trauma from an accident involving electric cable. Anaesthetic challenges, airway management and importance of effective close loop communication, during repair of complex tracheal reconstruction, will be discussed in this case report

    Delay between onset of indication and definitive surgery for tracheal trauma

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    Tracheal stenosis is rare but a recognized complication after traumatic injury or prolonged intubation. We assessed the time lag between onset of indication for tracheal reconstruction surgery following trauma and actual surgical intervention. We reviewed our operative records for all patients undergoing tracheal reconstruction over the past 10 years. Files were reviewed retrospectively to collect all the relevant data. Surgically all patients were operated via cervical approach. Series 12 cases were identified with an equal split between external trauma and iatrogenic tracheal trauma from prolonged intubation. On, an average patients presented 185 days after initial indication of surgery however there was a wide range of time lag which leads to the importance of early diagnosis of such injuries to reduce delay of definitive management

    Total parotidectomy under local anesthesia: A novel technique

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    Parotidectomy is a common procedure usually done for a parotid mass necessitating a histological diagnosis. Operation is normally performed under General anesthesia with a nerve stimulator to facilitate facial nerve stimulation. We describe a new technique with reports of three cases, making total parotidectomy under local anesthesia possible. The ascending cervical branch of cervical plexus and the auriculotemporal nerve were anesthetized by bupivacaine 0.25% (2mg/kg) and lignocaine with adrenaline 7 mg/kg. Effective onset of anesthesia was within 15-25 minutes and the operations lasted between 2-3 hours without any complications. This offers advantage in high-risk patients where general anesthesia is contraindicated. The facial nerve can be easily identified with on command movements by the patient rendering the use of nerve stimulator or injection of the dye superfluous. This technique makes total parotidectomy an outpatient procedure and facilitates an early discharge

    Experimental Study of Concentric Staggered Annular Fin with Radial Outlet and Staggered Rectangular Fin with Lateral Outlet

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    In this paper, an experimental study of a concentric staggered annular fin with radial outlets and a staggered rectangular fin with lateral outlets for steady-state natural convection, and forced convection is presented. The objective of this work is to investigate the effect of shape, profile and arrangement of the fins in heat transfer with minimum blockage ratio, stagnation, and pressure drop. In this regard, the two different shapes of fins are designed with the same material, identical extended surface area, width, and thickness; and studied experimentally with identical thermal load and boundary conditions, as well as identical flow characteristics. In case of forced convection, the orientation of the base-plate of the fins is kept perpendicular to the direction of flow to achieve velocity vectors parallel to the fin surfaces. The overall heat transfer coefficient, fin efficiency, effectiveness, and temperature distribution of both fins are compared for different base-plate's temperature of the fins and different free stream air velocity; and also for natural convection. It is found that the shape of the fins has a significant effect on heat transfer, especially in the case of forced convection. Though both fins are performed almost the same in natural convection, the concentric staggered annular fin with radial outlets performed better in forced convection. It is concluded that the concentric staggered annular fin with radial outlets can be used in the practical field instead of the conventional rectangular fin, particularly for forced convection

    Health system impact of COVID-19 on urban slum population of Bangladesh: a mixed-method rapid assessment study

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    Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Design Setting and participants A cross-sectional survey among 476 households was conducted during October–December 2020 in five selected urban slums of Dhaka North, Dhaka South and Gazipur City Corporation. In-depth interviews with purposively selected 22 slum dwellers and key informant interviews with 16 local healthcare providers and four policymakers and technical experts were also conducted. Outcome measures Percentage of people suffering from general illness, percentage of people suffering from chronic illness, percentage of people seeking healthcare, percentage of people seeking maternal care, health system challenges resulting from COVID-19. Results About 12% of members suffered from general illness and 25% reported chronic illness. Over 80% sought healthcare and the majority sought care from informal healthcare providers. 39% of the recently delivered women sought healthcare in 3 months preceding the survey. An overall reduction in healthcare use was reported during the lockdown period compared with prepandemic time. Mismanagement and inefficient use of resources were reported as challenges of health financing during the pandemic. Health information sharing was inadequate at the urban slums, resulting from the lack of community and stakeholder engagement (51% received COVID-19-related information, 49% of respondents knew about the national hotline number for COVID-19 treatment). Shortage of human resources for health was reported to be acute during the pandemic, resulting from the shortage of specialist doctors and uneven distribution of health workforce. COVID-19 test was inadequate due to the lack of adequate test facilities and stigma associated with COVID-19. Lack of strong leadership and stakeholder engagement was seen as the barriers to effective pandemic management. Conclusion The findings of the current study are expected to support the government in tailoring interventions and allocating resources more efficiently and timely during a pandemic.https://doi.org/10.1136/bmjopen-2021-05740212pubpub

    Comparison of the Postprocedural Quality of Life between Coronary Artery Bypass Graft Surgery and Percutaneous Coronary Intervention: A Systematic Review

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    The treatment of choice between coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) has remained unclear. Considering quality of life (QOL) increases life expectancy, we believe QOL should be important in determining the optimum treatment. Thus the objective of this review was to illustrate the comparative effects of CABG and PCI on postprocedural QOL. Methods. We searched PubMed (Medline) and Embase from inception of the databases to May 2014 using "PCI versus CABG quality of life", "Percutaneous Coronary intervention versus Coronary artery bypass graft surgery Quality of life", "PCI versus CABG health status", "Angioplasty versus CABG", "Percutaneous coronary intervention versus coronary artery bypass surgery health status", and different combinations of the above terms. 447 articles were found. After applying strict exclusion criteria, we included 13 studies in this review. Results. From the 9 studies that compared QOL scores at 6 months after procedure, 5 studies reported CABG to be superior. From the 10 studies that compared QOL among patients at 1 year after procedure, 9 reported CABG to be superior. Conclusion. It can be established that CABG is superior to PCI in improving patient's QOL with respect to all scales used to determine quality of life

    Comparison of the Postprocedural Quality of Life between Coronary Artery Bypass Graft Surgery and Percutaneous Coronary Intervention: A Systematic Review

    Get PDF
    The treatment of choice between coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) has remained unclear. Considering quality of life (QOL) increases life expectancy, we believe QOL should be important in determining the optimum treatment. Thus the objective of this review was to illustrate the comparative effects of CABG and PCI on postprocedural QOL. Methods. We searched PubMed (Medline) and Embase from inception of the databases to May 2014 using “PCI versus CABG quality of life”, “Percutaneous Coronary intervention versus Coronary artery bypass graft surgery Quality of life”, “PCI versus CABG health status”, “Angioplasty versus CABG”, “Percutaneous coronary intervention versus coronary artery bypass surgery health status”, and different combinations of the above terms. 447 articles were found. After applying strict exclusion criteria, we included 13 studies in this review. Results. From the 9 studies that compared QOL scores at 6 months after procedure, 5 studies reported CABG to be superior. From the 10 studies that compared QOL among patients at 1 year after procedure, 9 reported CABG to be superior. Conclusion. It can be established that CABG is superior to PCI in improving patient’s QOL with respect to all scales used to determine quality of life

    Neuronal activity disrupts myelinated axon integrity in the absence of NKCC1b

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    Through a genetic screen in zebrafish, we identified a mutant with disruption to myelin in both the CNS and PNS caused by a mutation in a previously uncharacterized gene, slc12a2b, predicted to encode a Na+, K+, and Cl− (NKCC) cotransporter, NKCC1b. slc12a2b/NKCC1b mutants exhibited a severe and progressive pathology in the PNS, characterized by dysmyelination and swelling of the periaxonal space at the axon–myelin interface. Cell-type–specific loss of slc12a2b/NKCC1b in either neurons or myelinating Schwann cells recapitulated these pathologies. Given that NKCC1 is critical for ion homeostasis, we asked whether the disruption to myelinated axons in slc12a2b/NKCC1b mutants is affected by neuronal activity. Strikingly, we found that blocking neuronal activity completely prevented and could even rescue the pathology in slc12a2b/NKCC1b mutants. Together, our data indicate that NKCC1b is required to maintain neuronal activity–related solute homeostasis at the axon–myelin interface, and the integrity of myelinated axons
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