QuickCast: Fast and Efficient Inter-Datacenter Transfers using Forwarding Tree Cohorts

Large inter-datacenter transfers are crucial for cloud service efficiency and are increasingly used by organizations that have dedicated wide area networks between datacenters. A recent work uses multicast forwarding trees to reduce the bandwidth needs and improve completion times of point-to-multipoint transfers. Using a single forwarding tree per transfer, however, leads to poor performance because the slowest receiver dictates the completion time for all receivers. Using multiple forwarding trees per transfer alleviates this concern--the average receiver could finish early; however, if done naively, bandwidth usage would also increase and it is apriori unclear how best to partition receivers, how to construct the multiple trees and how to determine the rate and schedule of flows on these trees. This paper presents QuickCast, a first solution to these problems. Using simulations on real-world network topologies, we see that QuickCast can speed up the average receiver's completion time by as much as $10\times$ while only using $1.04\times$ more bandwidth; further, the completion time for all receivers also improves by as much as $1.6\times$ faster at high loads.Comment: [Extended Version] Accepted for presentation in IEEE INFOCOM 2018, Honolulu, H

DCCast: Efficient Point to Multipoint Transfers Across Datacenters

Using multiple datacenters allows for higher availability, load balancing and reduced latency to customers of cloud services. To distribute multiple copies of data, cloud providers depend on inter-datacenter WANs that ought to be used efficiently considering their limited capacity and the ever-increasing data demands. In this paper, we focus on applications that transfer objects from one datacenter to several datacenters over dedicated inter-datacenter networks. We present DCCast, a centralized Point to Multi-Point (P2MP) algorithm that uses forwarding trees to efficiently deliver an object from a source datacenter to required destination datacenters. With low computational overhead, DCCast selects forwarding trees that minimize bandwidth usage and balance load across all links. With simulation experiments on Google's GScale network, we show that DCCast can reduce total bandwidth usage and tail Transfer Completion Times (TCT) by up to $50\%$ compared to delivering the same objects via independent point-to-point (P2P) transfers.Comment: 9th USENIX Workshop on Hot Topics in Cloud Computing, https://www.usenix.org/conference/hotcloud17/program/presentation/noormohammadpou

Pharmacokinetic Consideration to Formulate Sustained Release Drugs: Understanding the Controlled Drug Diffusion through the Body Compartment of the Systemic Circulation and Tissue Medium-A Caputo Model

الهدف من هذه الدراسة هو تقديم لمحة عامة عن النماذج المختلفة لدراسة انتشار الدواء لفترة طويلة في جسم الإنسان وداخله. تم التأكيد على نماذج المقصورة الرياضية باستخدام نهج المشتقة الجزئية (نموذج كابوتو) للتحقيق في التغير في تركيز الدواء المستدام في أجزاء مختلفة من نظام جسم الإنسان من خلال الطريق الفموي أو الطريق الوريدي. و تم استخدام قانون العمل الجماعي ، وحركية الدرجة الأولى ، ومبدأ الإرواء لفيك لتطوير نماذج المقصورة الرياضية التي تمثل انتشارا مستداما للأدوية في جميع أنحاء جسم الإنسان. للتنبؤ بشكل كافٍ بانتشار الدواء المستمر في أجزاء مختلفة من جسم الإنسان، وضعنا في الاعتبار(نموذج كابوتو (للتحقيق في معدل تغير التركيز اعتمادًا على التغيير في ترتيب التمايز الجزئي في جميع الأجزاء الممكنة من الجسم، أي الدوران الجهازي وحجرات الأنسجة. أيضا ، تم تعيين قيمة معلمة عددية لمعدل تدفق الدواء في مقصورات مختلفة لتقدير تركيز الدواء. تم حساب النتائج وتصوير الأرقام باستخدام برنامج MATLAB (الإصدار R2020a). التأثيرات الرسومية الموضحة للتغير في معدل التركيز بافتراض قيم وسيطة مختلفة وفقا للمشتقة الكسرية (نموذج كابوتو ). التأثيرات الرسومية الموضحة للتغير في معدل التركيز بافتراض قيم وسيطة مختلفة وفقا للمشتقة الكسرية (نموذج كابوتو). يخلص التمثيل البياني الناتج إلى أنه بالنظر إلى ترتيب قيم المعادلات التفاضلية ، يختلف تركيز الدواء اعتمادا على معدل الثوابت في المقصورات المتعلقة بالوقت.   النظر في الحالة الأولية للتقدير التقريبي حيث يشير الجسم كحجرة كاملة، بعد تقسيم الجسم إلى مقصورتين نموذجيتين. في حين أن النموذج الأول يمثل المعدة والكبد والدم الجهازي ؛ والنموذج الثاني يأخذ في الاعتبار الدم الشرياني وأنسجة الكبد والدم الوريدي.The aim of this study is to provide an overview of various models to study drug diffusion for a sustained period into and within the human body. Emphasized the mathematical compartment models using fractional derivative (Caputo model) approach to investigate the change in sustained drug concentration in different compartments of the human body system through the oral route or the intravenous route. Law of mass action, first-order kinetics, and Fick's perfusion principle were used to develop mathematical compartment models representing sustained drug diffusion throughout the human body. To adequately predict the sustained drug diffusion into various compartments of the human body, consider fractional derivative (Caputo model) to investigate the rate of concentration changing depending upon the change in the order of fractional differentiation in all the possible compartments of the body, i.e., systemic circulation and tissue compartments. Also, assigned a numerical parameter value to the rate of drug flow in different compartments to estimate the drug concentration. Results were calculated and figures were depicted by using MATLAB software (version R2020a). Illustrated graphical effects of change in concentration rate by assuming various intermediate values according to the fractional derivative (Caputo model). The resultant graphical representation concludes that considering the order of the differential equation values, the drug concentration varies depending upon its rate of constants in compartments concerning time. Considering the initial case for rough estimation where the body is indicated as a whole compartment, following division of the body into two model compartments. Whereas, the model I represents stomach, liver, and systemic blood, and model II consider arterial blood, liver tissue, and venous blood

Physiological studies on the effects of hormonal imbalance on the central nervous system

The acetylcholinesterase activity, RNA levels, total free amino acids and magnesium content in fore-, mid- and hind-brain were determined in the normal and hypophysectomised frogs (Rana cyanophlyctus). Hypophysectomy results in a marked decrease in the freea−a and in Mg. RNA also decreases significantly, but not to the same degree as thea−a and Mg. But AchE levels do not change significantly although there is a general decrease. It is suggested that the decrease in Mg is a reflection of the ionic imbalance resulting from hormonal imbalance. Hypophysectomy also results in reduced protein synthesis (and/or turnover) in the CNS as indicated by reduced RNA anda−a

XUV frequency comb metrology on the ground state of helium

The operation of a frequency comb at extreme ultraviolet (XUV) wavelengths based on pair-wise amplification and nonlinear upconversion to the 15th harmonic of pulses from a frequency comb laser in the near-infrared range is reported. Following a first account of the experiment [Kandula et al., Phys. Rev. Lett. 105, 063001 (2010)], an extensive review is given of the demonstration that the resulting spectrum at 51 nm is fully phase coherent and can be applied to precision metrology. The pulses are used in a scheme of direct-frequency-comb excitation of helium atoms from the ground state to the 1s4p and 1s5p 1P_1 states. Laser ionization by auxiliary 1064 nm pulses is used to detect the excited state population, resulting in a cosine-like signal as a function of the repetition rate of the frequency comb with a modulation contrast of up to 55%. Analysis of the visibility of this comb structure yields an estimated timing jitter between the two upconverted comb laser pulses of 50 attoseconds, whch indicates that extension to even shorter wavelengths should be feasible. The helium metrology investigation results in transition frequencies of 5740806993(10) MHz and 5814248672(6) MHz for excitation of the 1s4p and 1s5p 1P_1 states, respectively. This constitutes the first absolute frequency measurement in the XUV, attaining unprecedented accuracy in this windowless part of the electromagnetic spectrum. From the measured transition frequencies an eight-fold improved 4He ionization energy of 5945204212(6) MHz is derived. Also a new value for the 4He ground state Lamb shift is found of 41247(6) MHz. This experimental value is in agreement with recent theoretical calculations up to order m\alpha^6 and m^2/(M\alpha^5), but with a six times higher precision, therewith providing a stringent test of quantum electrodynamics in bound two-electron systems.Comment: 18 pages, 13 figure

A STUDY ON THE PREVALENCE AND SEVERITY OF POSSIBLE DRUG-DRUG INTERACTIONS IN PEDIATRICS DEPARTMENT AT AN INDIAN TERTIARY CARE TEACHING HOSPITAL

Objective: To study the prevalence and severity of possible drug-drug interactions in the department of pediatrics.Methods: Case records of the in-patients of the pediatrics department from the medical records department were included and the records of the ambulatory patients were excluded from the study. All the collected cases were subjected to check for the drug-drug interactions by using the software micromedex 2.0 and the interactions were categorized based on the severity into minor, moderate and major.Results: A total of 142 cases were screened for possible drug-drug interactions (DDIs) and among them 76 cases were observed to be with possible DDIs.  The prevalence was found to be 53.5% in this study. Majority of the cases with possible DDIs were observed to be in females. Results of the age wise categorization revealed that majority of the possible DDIS were observed in children (2-12 y) followed by the infants (1 mo–2 y). The drug combinations amikacin+ampicillin, paracetamol+phenytoin and ofloxacin+ondansetron were found to be the frequently observed possible DDIs of minor, moderate and major severities respectively.Conclusion: Majority of the possible DDIs were of moderate severity followed by major. Clinical pharmacists should take the responsibility in assisting the pediatricians for screening the possible DDIs in the prescriptions there by preventing them and providing a better pharmaceutical care for the pediatric population. Â

Physiology of low temperature acclimation in tropical poikilotherms. III. Quantitative changes in the bound and free amino acids in the earthworm, Lampito mauritii

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