Analysis of an M[X]/G/1 Feedback Retrial Queue with Two Phase Service, Bernoulli Vacation, Delaying Repair and Orbit Search

In this paper, we considered a batch arrival feedback retrial queue with two phase of service under Bernoulli vacation schedule and orbit search. At the arrival epoch of a batch, if the server is busy, under repair or on vacation then the whole batch joins the orbit. Where as if the server is free, then one of the arriving customers starts his service immediately and the rest join the orbit. At the completion epoch of each service, the server either goes for a vacation or may wait for serving the next customer. While the server is working with any phase of service, it may breakdown at any instant and the service channel will fail for a short interval of time. The repair process does not start immediately after a breakdown and there is a delay time for repair to start. After vacation completion, the server searches for the customers in the orbit (i.e. customer in the orbit, if any taken for service immediately) or remains idle. The probability generating function of the number of customers in the system and orbit are found using the supplementary variable technique. The mean numbers of customers in the system/orbit and special cases are analyzed. The effects of various parameters on the performance measure are illustrated numerically. Keywords: Feedback, retrial queue, Bernoulli vacation, delaying repair, orbit searc

Optimum cost analysis of batch service retrial queuing system with server failure, threshold and multiple vacations

The aim of this paper is to analyze the queuing model entitled to cost optimization in bulk arrival and a batch service retrial queuing system with threshold, server failure, non-disruptive service, and multiple vacations. When bulk arrival of customers find the server is busy, then all customers will join in the orbit. On the other hand, if the server is free, then batch service will be provided according to the general bulk service rule. Batch size varies from a minimum of one and a maximum of ‘b’ number of customers. Customers in the orbit seek service one by one through constant retrial policy whenever the server is in idle state. The server may encounter failure during service. If the server fails, then ‘renewal of service station’ will be considered with probability . If there is no server failure with probability in the service completion or after the renewal process and if the orbit is empty, the server then leaves for multiple vacations. The server stays on vacation until the orbit size reaches the value N. For this proposed queuing model, a probability generating function of the orbit size will be obtained by using the supplementary variable technique and various performance measures will be presented with suitable numerical illustrations. A real time application is also discussed for this system. Additionally, a cost effective model is developed for this queuing model

Bryostatin Modulates Latent HIV-1 Infection via PKC and AMPK Signaling but Inhibits Acute Infection in a Receptor Independent Manner

HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC) -α and -δ, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC) involving stress induced AMP Kinase (AMPK) inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs

STRATEGI PUBLIC RELATONS TRANS TV DALAM MEMBINA HUBUNGAN BAIK DENGAN TRANSMANIA (COMMUNITY RELATIONS)

Strategi dalam faktor pengkoordinasi, prinsip yang menjadi penuntun, ide utama, dan pemikiran dibalik program taktis. Strategi berguna untuk memberikan fokus terhadap usaha yang dilakukan dan membantu dalam mendapatkan hasil yang sesuai dan tujuan perusahaan. Strategi Public Relations adalah alternative optimal yang ditempuh guna mancapai tujuan Public Relations dalam kerangka suatu rencana Public Relations. Strategi Public Relations Trans TV dalam membina Community Relations dengan Transmania adalah perencanaan atau faktor pengkordinasi program Community Relations dimana dalam penyusunannya Publik Relations mempelajari target audience terlebih dahulu yaitu Transmania, agar strategi yang disusun tersebut dapat sesuai dengan tujuan perusahaan dan dapat memenuhi kepentingan komunitas dan perusahaan. Penelitian ini bertujuan untuk mengetahui strategi yang digunakan Public Realations Trans TV dalam membina hubungan baik dengan Transmani, dengan menggunakan tipe penelitian deskriptif. Sampel yang diambil adalah pihak Trans TV dan beberapa anggota Transmania, melalui wawancara kepada responden. Teknik analisa yang digunakan secara kualitatif. Pada penelitian ini menunjukan bahwa strategi PR Trans TV dalam membina hubungan baik dengan Transmania melalui empat tahapan yaitu fact finding, planning, communicatating and actions, evaluating. Fokus utama strategi adalah bidang sosial kemanusian yang diselenggarakan oleh berbagai organisasi atau lembaga. Dalam tahap pengumpulan fakta PR Trans TV menjabarkan dasar pembentukan Transmania sebagai komunitas pemirsa setia Trans TV yang berfungsi untuk meningkatkan awareness masyarakat terhadap kualitas Program Trans TV. Dalam tahap planning PR Trans TV mendiskusikan program yang disusun dengan divisi lain dalam rapat kerja internal. Dalam merencanakan program, PR Trans TV juga berkomunikasi dengan Transmania antara lain dengan melakukan gathering. Keberhasialan pelaksanaan program ditentukan oleh kerjasama yang bai antara PR Trans TV dengan Transmania, media yang digunakan PR Trans TV dalam penyampaian informasi mengenai program yang akan dilaksanakan yaitu melalui media ON Line dan menggunakan alat komunikasi seperti Telepon seluler dan telepon biasa. Evaluasi dengan survey yang dilakukan setiap enam bulan sekali dilakukan segera setelah program dilaksanakan. Hasil survey kemudian akan dikaji dan didiskusikan pada rapat kerja internal PR Trans TV. Bagi Transmania evaluasi dilakukan saat gathering dengan PR Trans TV. Melalui strategi yang digunakan PR Trans TV, pelaksanaan program Transmania (Community Realations) menjadi terstruktur dan dapat sesuai dengan tujuan perusahaan

Performance prediction of interactive telemedicine

Telemedicine is a remote medical practice, which utilizes information and communication technology to provide healthcare and exchange of health information for distance places. Diagnosis and prescription for rural and remote area patients are the main advantages of this system. The major categories of telemedicine are store-and-forward, remote patient monitoring and interactive telemedicine. Interactive telemedicine is a real-time interaction between patients and doctors. This method can be conducted in a nursing home or at the patient's house via a video-conferencing system. Moreover, this is more convenient for patients, than to obtain health care with a caretaker in person. However, Internet-based networks are congested with many users. We considered interactive telemedicine as a queueing system and analyzed it by using the method of supplementary variables. We obtained the performance measures through a probability generating function. The numerical results of the queueing system may be useful to provide service satisfactorily and update the utility function of interactive telemedicine. Keywords: Telemedicine, Interactive telemedicine, Queueing system, Supplementary variable techniqu

Structure of Bands

Abstract A band is a semigroup of idempotents. The text book by J. M. Howie Mathematics Subject Classification: 20M1

Insights on PRAME and osteosarcoma by means of gene expression profiling

Osteosarcoma (OS) is the most frequent bone tumor in children and adolescents. Tumor antigens are encoded by genes that are expressed in many types of solid tumors but are silent in normal tissues, with the exception of placenta and male germ-line cells. It has been proposed that antigen tumors are potential tumor markers. The premise of this study is that the identification of novel OS-associated transcripts will lead to a better understanding of the events involved in OS pathogenesis and biology. We analyzed the expression of a panel of seven tumor antigens in OS samples to identify possible tumor markers. After selecting the tumor antigen expressed in most samples of the panel, gene expression profiling was used to identify osteosarcoma-associated molecular alterations. A microarray was employed because of its ability to accurately produce comprehensive expression profiles. PRAME was identified as the tumor antigen expressed in most OS samples; it was detected in 68% of the cases. Microarray results showed differences in expression for genes functioning in cell signaling and adhesion as well as extracellular matrix-related genes, implying that such tumors could indeed differ in regard to distinct patterns of tumorigenesis. The hypothesis inferred in this study was gathered mostly from available data concerning other kinds of tumors. There is circumstantial evidence that PRAME expression might be related to distinct patterns of tumorigenesis. Further investigation is needed to validate the differential expression of genes belonging to tumorigenesis-related pathways in PRAME-positive and PRAME-negative tumors.FAPESP (The State of Sao Paulo Research Foundation)[04/12150-8]FAPESP (The State of Sao Paulo Research Foundation)[07/53869-3]GRAACC (Grupo de Apoio ao Adolescente e Crianca com Cancer