Analysis of repairable M[X]/(G1,G2)/1 - feedback retrial G-queue with balking and starting failures under at most J vacations

In this paper, we discuss the steady state analysis of a batch arrival feedback retrial queue with two types of services and negative customers. Any arriving batch of positive customers finds the server is free, one of the customers from the batch enters into the service area and the rest of them get into the orbit. The negative customer, is arriving during the service time of a positive customer, will remove the positive customer in-service and the interrupted positive customer either enters the orbit or leaves the system. If the orbit is empty at the service completion of each type of service, the server takes at most J vacations until at least one customer is received in the orbit when the server returns from a vacation. While the busy server may breakdown at any instant and the service channel may fail for a short interval of time. The steady state probability generating function for the system size is obtained by using the supplementary variable method. Numerical illustrations are discussed to see the effect of the system parameters

Analysis of repairable M[X]/(G1,G2)/1 - feedback retrial G-queue with balking and starting failures under at most J vacations

In this paper, we discuss the steady state analysis of a batch arrival feedback retrial queue with two types of service and negative customers. Any arriving batch of positive customers finds the server is free, one of the customers from the batch enters into the service area and the rest of them join into the orbit. The negative customer, arriving during the service time of a positive customer, will remove the positive customer in-service and the interrupted positive customer either enters into the orbit or leaves the system. If the orbit is empty at the service completion of each type of service, the server takes at most J vacations until at least one customer is received in the orbit when the server returns from a vacation. The busy server may breakdown at any instant and the service channel will fail for a short interval of time. The steady state probability generating function for the system size is obtained by using the supplementary variable method. Numerical illustrations are discussed to see the effect of system parameters

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

Small cell variant of anaplastic large cell lymphoma with positive immunoreactivity for CD99

A 13 year old boy presented with a huge mass on his right arm of 6 months duration. Histopathological examination revealed sheets of malignant small round blue cells with immunopositivity for LCA, CD43, CD45Ro, CD30, EMA, ALK-1 and CD99, and negativity for CD20, TdT, myogenin, myoD1, NSE, bcl-6, bcl-2 and CD10. Fluorescent In-Situ Hybridization (FISH) testing excluded the diagnosis of Ewing's sarcoma/ PNET. Pathologists need to be aware of the diagnosis of a small cell variant of ALCL, as well as of the fact that CD99 expression commonly occurs in cases of ALK-positive ALCL, in order to distinguish this entity from Ewing's sarcoma/PNET

Manpower management in construction projects

Construction projects generally involve a long period of construction, huge financial investment and more problems that need to be faced in the development process. Several risk factors have to be encountered, among those one of the major risk factors is Manpower Management. Though the construction sector employs more people than other industries do, its human resource management is still poor and ineffective. This review paper concentrates on a workforce that directly contributes to the building process, labours, site engineers, and engineers or contractors. This study helps engineers or contractors to understand the value of labour resource management in the project to effectively manage them in construction projects. The primary issues in managing labour resources in construction projects have been identified with the help of a literature survey. The major problems identified will be considered for further investigation on manpower management

Electrical manipulation of spin states in a single electrostatically gated transition-metal complex

We demonstrate an electrically controlled high-spin (S=5/2) to low-spin (S=1/2) transition in a three-terminal device incorporating a single Mn2+ ion coordinated by two terpyridine ligands. By adjusting the gate-voltage we reduce the terpyridine moiety and thereby strengthen the ligand-field on the Mn-atom. Adding a single electron thus stabilizes the low-spin configuration and the corresponding sequential tunnelling current is suppressed by spin-blockade. From low-temperature inelastic cotunneling spectroscopy, we infer the magnetic excitation spectrum of the molecule and uncover also a strongly gate-dependent singlet-triplet splitting on the low-spin side. The measured bias-spectroscopy is shown to be consistent with an exact diagonalization of the Mn-complex, and an interpretation of the data is given in terms of a simplified effective model.Comment: Will appear soon in Nanoletter

HOPX functions as a tumour suppressor in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) is generalized term that encompasses a diverse group of cancers that includes tumours of the oral cavity (OSCC), oropharynx (OPSCC) and nasopharynx (NPC). Genetic alterations that are common to all HNSCC types are likely to be important for squamous carcinogenesis. In this study, we have investigated the role of the homeodomain-only homeobox gene, HOPX, in the pathogenesis of HNSCC. We show that HOPX mRNA levels are reduced in OSCC and NPC cell lines and tissues and there is a general reduction of HOPX protein expression in these tumours and OPSCCs. HOPX promoter methylation was observed in a subset of HNSCCs and was associated with a worse overall survival in HPV negative tumours. RNAseq analysis of OSCC cells transfected with HOPX revealed a widespread deregulation of the transcription of genes related to epithelial homeostasis and ectopic over-expression of HOPX in OSCC and NPC cells inhibited cell proliferation, plating efficiency and migration, and enhanced sensitivity to UVA-induced apoptosis. Our results demonstrate that HOPX functions as a tumour suppressor in HNSCC and suggest a central role for HOPX in suppressing epithelial carcinogenesis

5′-Inositol phosphatase SHIP2 recruits Mena to stabilize invadopodia for cancer cell invasion

Invadopodia are specialized membrane protrusions that support degradation of extracellular matrix (ECM) by cancer cells, allowing invasion and metastatic spread. Although early stages of invadopodia assembly have been elucidated, little is known about maturation of invadopodia into structures competent for ECM proteolysis. The localized conversion of phosphatidylinositol(3,4,5)-triphosphate and accumulation of phosphatidylinositol(3,4)-bisphosphate at invadopodia is a key determinant for invadopodia maturation. Here we investigate the role of the 5′-inositol phosphatase, SHIP2, and reveal an unexpected scaffold function of SHIP2 as a prerequisite for invadopodia-mediated ECM degradation. Through biochemical and structure-function analyses, we identify specific interactions between SHIP2 and Mena, an Ena/VASP-family actin regulatory protein. We demonstrate that SHIP2 recruits Mena, but not VASP, to invadopodia and that disruption of SHIP2–Mena interaction in cancer cells leads to attenuated capacity for ECM degradation and invasion in vitro, as well as reduced metastasis in vivo. Together, these findings identify SHIP2 as a key modulator of carcinoma invasiveness and a target for metastatic disease