A Note on the Characterization of Zero-Inflated Poisson Model

Zero-Inflated Poisson model has found a wide variety of applications in recent years in statistical analyses of count data, especially in count regression models. Zero-Inflated Poisson model is characterized in this paper through a linear differential equation satisfied by its probability generating function [1] [2]

A Model of Dynamic Resource Allocation in Workflow Systems

Current collaborative work environments are characterized by dynamically changing organizational structures. Although there have been several efforts to refine work distribution, especially in workflow management, most literature assumes a static database approach which captures organizational roles, groups and hierarchies and implements a dynamic roles based agent assignment protocol. However, in practice only partial information may be available for organizational models, and in turn a large number of exceptions may emerge at the time of work assignment. In this paper we present an organizational model based on a policy based normative system. The model is based on a combination of an intentional logic of agency and a flexible, but computationally feasible, non-monotonic formalism (Defeasible Logic). Although this paper focuses on the model specification, the proposed approach to modelling agent societies provides a means of reasoning with partial and unpredictable information as is typical of organizational agents in workflow system

Coherent states for polynomial su(1,1) algebra and a conditionally solvable system

In a previous paper [{\it J. Phys. A: Math. Theor.} {\bf 40} (2007) 11105], we constructed a class of coherent states for a polynomially deformed $su(2)$ algebra. In this paper, we first prepare the discrete representations of the nonlinearly deformed $su(1,1)$ algebra. Then we extend the previous procedure to construct a discrete class of coherent states for a polynomial su(1,1) algebra which contains the Barut-Girardello set and the Perelomov set of the SU(1,1) coherent states as special cases. We also construct coherent states for the cubic algebra related to the conditionally solvable radial oscillator problem.Comment: 2 figure

Kinetic characterization of the critical step in HIV-1 protease maturation

HIV maturation requires multiple cleavage of long polyprotein chains into functional proteins that include the viral protease itself. Initial cleavage by the protease dimer occurs from within these precursors, and yet only a single protease monomer is embedded in each polyprotein chain. Self-activation has been proposed to start from a partially dimerized protease formed from monomers of different chains binding its own N termini by self-association to the active site, but a complete structural understanding of this critical step in HIV maturation is missing. Here, we captured the critical self-association of immature HIV-1 protease to its extended amino-terminal recognition motif using large-scale molecular dynamics simulations, thus confirming the postulated intramolecular mechanism in atomic detail. We show that self-association to a catalytically viable state requires structural cooperativity of the flexible β-hairpin “flap” regions of the enzyme and that the major transition pathway is first via self-association in the semiopen/open enzyme states, followed by enzyme conformational transition into a catalytically viable closed state. Furthermore, partial N-terminal threading can play a role in self-association, whereas wide opening of the flaps in concert with self-association is not observed. We estimate the association rate constant (k(on)) to be on the order of ∼1 × 10(4) s(−1), suggesting that N-terminal self-association is not the rate-limiting step in the process. The shown mechanism also provides an interesting example of molecular conformational transitions along the association pathway

Amino acids and insulin act additively to regulate components of the ubiquitin-proteasome pathway in C2C12 myotubes

BACKGROUND: The ubiquitin-proteasome system is the predominant pathway for myofibrillar proteolysis but a previous study in C2C12 myotubes only observed alterations in lysosome-dependent proteolysis in response to complete starvation of amino acids or leucine from the media. Here, we determined the interaction between insulin and amino acids in the regulation of myotube proteolysis RESULTS: Incubation of C2C12 myotubes with 0.2 × physiological amino acids concentration (0.2 × PC AA), relative to 1.0 × PC AA, significantly increased total proteolysis and the expression of 14-kDa E2 ubiquitin conjugating enzyme (p < 0.05). The proteasome inhibitor MG132 blocked the rise in proteolysis observed in the 0.2 × PC AA media. Addition of insulin to the medium inhibited proteolysis at both 0.2 and 1.0× PC AA and the expression of 14-kDa E2 proteins and C2 sub unit of 20 S proteasome (p < 0.05). Incubation of myotubes with increasing concentrations of leucine in the 0.2 × PC AA media inhibited proteolysis but only in the presence of insulin. Incubation of rapamycin (inhibitor of mTOR) inhibited amino acid or insulin-dependent p70 S6 kinase phosphorylation, blocked (P < 0.05) the inhibitory effects of 1.0 × PC AA on protein degradation, but did not alter the inhibitory effects of insulin or leucine CONCLUSION: In a C2C12 myotube model of myofibrillar protein turnover, amino acid limitation increases proteolysis in a ubiquitin-proteasome-dependent manner. Increasing amino acids or leucine alone, act additively with insulin to down regulate proteolysis and expression of components of ubiquitin-proteasome pathway. The effects of amino acids on proteolysis but not insulin and leucine, are blocked by inhibition of the mTOR signalling pathway

Can remote STI/HIV testing and eClinical Care be compatible with robust public health surveillance?

In this paper we outline the current data capture systems for human immunodeficiency virus (HIV) and sexually transmitted infection (STI) surveillance used by Public Health England (PHE), and how these will be affected by the introduction of novel testing platforms and changing patient pathways. We outline the Chlamydia Online Clinical Care Pathway (COCCP), developed as part of the Electronic Self-Testing for Sexually Transmitted Infections (eSTI(2)) Consortium, which ensures that surveillance data continue to be routinely collected and transmitted to PHE. We conclude that both novel diagnostic testing platforms and established data capture systems must be adaptable to ensure continued robust public health surveillance

Generalized mean-field study of a driven lattice gas

Generalized mean-field analysis has been performed to study the ordering process in a half-filled square lattice-gas model with repulsive nearest neighbor interaction under the influence of a uniform electric field. We have determined the configuration probabilities on 2-, 4-, 5-, and 6-point clusters excluding the possibility of sublattice ordering. The agreement between the results of 6-point approximations and Monte Carlo simulations confirms the absence of phase transition for sufficiently strong fields.Comment: 4 pages (REVTEX) with 4 PS figures (uuencoded

Evaluation of the Water Quality of River Kaduna, Nigeria Using Water Quality Index

Water is a natural resource of fundamental importance and supports all life forms. The study evaluated the water quality of River Kaduna using the Canadian Council of Ministers of the Environment (CCME) Water Quality Index. The study covered both raining and dry seasons in 10 sampling points. Water parameters analysed were turbidity, Zn, Pb, Cd, Cr, Cu, Mn, Fe, dissolved oxygen, electrical conductivity, pH, TDS and Ni using standard laboratory techniques. The data obtained were used to develop Water Quality Index (WQI) across the 10 sampling points and results showed that the water quality at Barnawa, Kudenda, Tudun Wada, Makera and Angwan Muazu are poor as their index values ranged between 31.8 – 42 while Kawo, Angwan Dosa, Malali, Kigo and Angwan Rimi are marginal as their index ranged between 45 – 61.3. The study concluded that the variety and level of contaminants in River Kaduna was related to the anthropogenic activities in the various parts of Kaduna Metropolis from where run-off and contaminants were received, hence, the water quality of River Kaduna is deteriorating. There is therefore the need for proper environmental education and discouragement in the use of toxic chemicals for farming so that pollution can be controlled at the source.&nbsp

Hepatitis B testing and treatment in HIV patients in The Gambia - compliance with international guidelines and clinical outcomes

Background Compliance with WHO guidelines on HBV screening and treatment in HIV-coinfected patients is often challenging in resource limited countries and has been poorly assessed in sub-Saharan Africa. Methods Between 2015 and 2016, we assessed physician’s compliance with WHO guidelines on HIV-HBV coinfection in the largest HIV clinic in The Gambia, and the hepatic outcomes in HIV-HBV coinfected patients as compared to randomly selected HIV-monoinfected controls. Results 870 HIV-infected patients regularly seen in this clinic agreed to participate in our study. Only 187 (21.5%, 95% CI 18.8–24.3) had previously been screened for HBsAg, 23 (12.3%, 95% CI 8.0–17.9) were positive of whom none had liver assessment and only 6 (26.1%) had received Tenofovir. Our HBV testing intervention was accepted by all participants and found 94/870 (10.8%, 95% CI 8.8–13.1) positive, 78 of whom underwent full liver assessment along with 40 HBsAg-negative controls. At the time of liver assessment, 61/78 (78.2%) HIV-HBV coinfected patients received ART with 7 (11.5%) on Tenofovir and 54 (88.5%) on Lamivudine alone. HIV-HBV coinfected patients had higher APRI score compared to controls (0.58 vs 0.42, p = 0.002). HBV DNA was detectable in 52/53 (98.1%) coinfected patients with 14/53 (26.4%) having HBV DNA >20,000 IU/L. 10/12 (83.3%) had at least one detectable 3TC-associated HBV resistance, which tended to be associated with increase in liver fibrosis after adjusting for age and sex (p = 0.05). Conclusions Compliance with HBV testing and treatment guidelines is poor in this Gambian HIV programme putting coinfected patients at risk of liver complications. However, the excellent uptake of HBV screening and linkage to care in our study suggests feasible improvements

Production and Economics Evaluation of Pilot Scale Essential Oil Extract from Eucalyptus Citriodora Leaves

In this study, essential oil was extracted from eucalyptus citriodora leaves plant species (lemon-scented gum) in a pilot plant using steam distillation technology. The extraction pattern of the oil was monitored over time and economic analysis of the production was carried out. &nbsp;Five batches were carried out in a day and the results revealed that the daily production of the oil was 0.579 liters in a loading capacity of 100kg of leaves. It was also observed that the total production cycle per batch was 1.96 hours out of which 80 minutes were the actual extraction time with lag period of 37 minutes. The results further revealed that 66.7% of the oil was extracted in 40 minutes while 95.6% in 80 minutes. Liquefied petroleum gas (LPG) was used as source of energy with daily consumption of 7.5 kg at a cost of N2,400.00K. The economic analysis on annual basis revealed that the operating cost was N1,742,400.00K. The production output of the oil was estimated at 138.96 litres with expected selling price of N4,863,600.00K at the rate of N35,000.00K per litre and expected profit after tax of N2,115,871.00K. From this economic analysis carried out based on the practical data generated in the pilot plant, this project is highly profitable and is strongly recommended to potential investors and entrepreneurs. This will help in providing jobs for our teaming unemployed youths mostly in rural areas where these raw materials are in abundant thereby increasing nation’s foreign earning due to its export potential