Optimizing multiship routing and scheduling with constraints on inventory levels in a Brazilian oil company

This study addresses a real‐life multiship routing and scheduling application with inventory constraints that arises in pickup and delivery operations of different types of crude oil from various offshore oil rigs (platforms) to coastal terminals. Oil transportation largely results from the need to maintain inventories at each supply point (platform) between minimum and maximum levels, considering production rates in these operational points, and to meet demands of different oils in the terminals within the planning time horizon. Routing and scheduling of the available fleet aims to obtain solutions of minimum total costs, subject to various constraints such as the maximum volume of cargo carried on each ship, simultaneous cargo unloading in some terminals, conditions that rule ship docking in offshore platforms and terminal berths, among others. In this research, we modify and extend inventory constrained maritime routing and scheduling models to appropriately represent the problem of a case study at a Brazilian company and to solve small‐to‐moderate instances based on real data. We also present a matheuristic to deal with larger problem instances. Solution evaluation by company experts indicates that the model and this hybrid heuristic properly represent the problem and highlights the potential of their application in practice.     

Traffic specifications for the transmission of stored MPEG video onthe Internet

Guarantees of quality-of-service (QoS) in the real-time transmission of stored video on the Internet is a challenging task for the success of many video on demand (VoD) applications. Two QoS classes have been specified by the IETF Integrated Services (intserv) Working Group: Guaranteed Services and Controlled-Load Services. For both of them, it is necessary to provide traffic sources with the capability of calculating the traffic characteristics to be declared to the network, Tspec, on the basis of a limited set of parameters statistically characterizing the traffic and the required level of QoS. The target of this paper is to develop an algorithm for the evaluation of the Tspec parameters which characterize the video stream when a given QoS is required. To this end an analytical framework modeling an MPEG stored-video server and the access network node is introduced. The video emission process is modeled with a switched batch Bernoulli process (SBBP), and performance in the video-server smoother is analytically evaluated. Then the token bucket at the network access point, loaded by the output traffic of the video-server smoother, is modeled to calculate the probability of marking nonconforming data packets     

A survey of critical success factors in e-Banking: an organisational perspective

We investigate organisational factors critical to the success of e-Banking (EB). Scholars report that a variety of factors are vital to EB success. A shortcoming in the extant EB literature is that much of the research focuses on a small subset of success factors and an overall ranking of factors is still missing. Our aim, therefore, is to synthesise and test the critical success factors (CSFs) identified in the existing literature, thus, substantiating or not the factors purported to be critical. To achieve our aim, we created a survey instrument from a synthesis of CSFs identified from existing EB and e-commerce literature. We draw upon the e-commerce body of knowledge to take in the widest set of CSFs that can affect EB. Data were collected from U.K.-based financial sector organisations that offer EB services. We found the most critical factors for success in EB are: quick responsive products/services, organisational flexibility, services expansion, systems integration and enhanced customer service. Our research shows that organisations need to manage their EB initiative at a strategic level and treat it as business critical rather than simply a technical or operational issue. They need to pay attention to internal integration, which includes channels, technology and business process integration, and improving the overall services to their customers.     

Effects of changing freestall area on lameness,lying time,and leg injuries on dairy farms in Alberta,Canada

Cow comfort is of increasing importance in the dairy industry, due to an increased focus on animal welfare. However, whether producer changes to the cows' environment affect cow comfort has not been well characterized. Our objectives were to: (1) quantify the effect of freestall area changes on the prevalence of lameness, leg injuries, and average lying time; and (2) compare cow comfort outcomes on farms that had never had an assessment of cow comfort to farms that had had a previous assessment of cow comfort. A sample of 60 Holstein-Friesian cows were selected on each of 15 farms that made changes to the freestall area after an assessment of cow comfort (change, CHG); 15 farms that did not make changes to the freestall area after an assessment of cow comfort (no change, NC); and 14 farms that had yet to be evaluated (new farms, NF). Cows in NC and NF were lame 1.50 and 1.71 times more often, respectively, than cows on CHG farms. Additionally, daily lying time was 0.33 and 0.62 h/d lower in NC and NF, respectively, than on CHG farms. The prevalence of hock and knee injuries was not different among the 3 groups of farms. No differences were detected in the parameters of interest when comparing NF with NC farms; therefore, we concluded that the NC group was not biased by a previous assessment of cow comfort. Farms in the CHG group had a lower prevalence of lame cows and greater lying time than the NC and NF groups.     

Uptake and distribution of fluorescein-labeled D2 dopamine receptor antisense oligodeoxynucleotide in mouse brain

To determine the uptake and distribution of oligodeoxynucleotides in brain, a 20-mer phosphorothioated oligodeoxynucleotide complementary to a portion of the D2 dopamine receptor mRNA was fluorescently labeled with fluorescein isothiocyanate (FITC) and injected into the lateral cerebral ventricles of mice. At various survival times after the injection, the brains were removed, fixed, sectioned, and viewed under a fluorescent microscope. The results showed that the oligodeoxynucleotide was rapidly taken up into the brain. Initially the label was relatively diffusely spread throughout the interstitial spaces of the brain, then became redistributed to the cellular compartments. The signal extended from those forebrain nuclei located immediately in contact with the ventricles, such as the corpus striatum, septum, and hippocampus, to areas further removed from the ventricles, such as the cerebral cortex, nucleus accumbens, and substantia nigra. When the FITC-labeled D2 antisense oligodeoxynucleotide was given once daily for 4 d, the signal intensity seen 24 h after the last injection appeared to be of greater intensity overall compared to that seen after a single injection. At early time-points the oligodeoxynucleotide signals appeared to be punctuated and were found in cell bodies as well as in proximal dendritic processes. However, not all cells were equally labeled, suggesting an uneven uptake and accumulation of the D2 antisense into the various cell types. At later time-points the fluorescent signal appeared granular; at these times the injected material was largely degraded. These studies show that a D2 dopamine receptor antisense oligodeoxynucleotide is rapidly taken up from cerebral ventricles into brain, becomes widely distributed throughout the brain tissue to areas far removed from direct contact with the ventricles, and appears to accumulate to a different extent in the various brain areas and cell types.     

The divergent homeobox gene PBX1 is expressed in the postnatal subventricular zone and interneurons of the olfactory bulb

In the mammalian brain, an important phase of neurogenesis occurs postnatally in the subventricular zone (SVZ). This region consists of a heterogeneous population of cells, some mitotically active, others postmitotic. A subset of mitotically active SVZ precursor cells gives rise to a population of neurons that migrates over a long distance to their final destination, the olfactory bulb. Other SVZ precursor cells continue to proliferate or undergo cell death. The combination of genes that regulates proliferation and cell fate determination of SVZ precursor cells remains to be identified. We have used the rat homolog of the human homeobox gene PBX1 in Northern analysis and in situ hybridization studies to determine the temporal and regional localization of PBX1 expression during embryonic and postnatal rat brain development. PBX1 is expressed embryonically in the telencephalon. In addition, it is expressed at high levels postnatally in the SVZ, in the migratory pathway to the olfactory bulb, and in the layers of the olfactory bulb that are the targets of these migratory neurons. Combining in situ hybridization for PBX1 with immunostaining for markers of cell proliferation (PCNA), postmitotic neurons (class III beta-tubulin), and glia (GFAP), we show that SVZ proliferating cells and their neuronal progeny express rat PBX1 mRNA, whereas glial cells do not express detectable levels of PBX1. The expression of PBX1 in SVZ precursor cells and postmitotic neurons suggests a role for PBX1 in the generation of olfactory bulb interneurons and in mammalian neurogenesis.     

A randomized, controlled trial of a 24-month course of interferon alfa 2b in patients with chronic hepatitis B who had hepatitis B virus DNA without hepatitis B e antigen in serum

Short-term interferon treatment of serum hepatitis B e antigen (HBeAg)-negative carriers with serum hepatitis B virus (HBV) DNA and histological features of chronic hepatitis B has been largely unsuccessful. In a pilot study of long-term treatment, 42 such patients were randomly assigned to 6 million units of interferon alfa 2b (IFN-alpha2b) three times per week for 24 consecutive months (n = 21, 4 with cirrhosis) or to no therapy (n = 21, 3 with cirrhosis). Five patients (24%) discontinued therapy because of treatment-related adverse reactions. Serum levels of alanine transaminase (ALT) became persistently normal and HBV DNA undetectable by dot-blot assay in 8 patients receiving interferon and in 2 untreated controls (38% vs. 10%; P = .03). Hepatitis flare-ups disappeared in 17 patients during therapy compared with 6 controls (81% vs. 29%; P < .001). During a median period of 22 months after interferon was stopped, 2 treated patients (10%) lost serum hepatitis B surface antigen (HBsAg) and seroconverted to antibodies to hepatitis B surface antigen (anti-HBs). Serum ALT remained persistently normal and HBV DNA undetectable by dot-blot assay in 6 initial responders and 1 initial nonresponder, compared with none of the 21 untreated controls (sustained response: 33% vs. 0; P < .001). Comparative analysis of pre- and posttreatment liver biopsies showed that mean Knodell scores dropped in the treated group (10.3 to 5.3; P = .01), but not in the untreated group (9.3 to 9.8; not significant). In conclusion, a 24-month course of treatment with 6 MU IFN-alpha2b was well tolerated by most patients, led to sustained suppression of HBV in one third, and attenuated hepatitis in 81% of patients.     

Fasciotomy, chronic venous insufficiency, and the calf muscle pump

OBJECTIVE: To test the hypothesis that fasciotomy may impair the function of the calf muscle pump, which in turn could result in the development of chronic venous insufficiency. DESIGN: A cohort study of patients with a history of lower extremity fasciotomy. SETTING: An urban trauma center. PATIENTS: Seventeen of the 83 patients identified through trauma, vascular, and/or orthopedic registries consented to participation in this study. INTERVENTIONS: Participating patients completed a study questionnaire, and then underwent a complete vascular examination, including air plethysmographic (APG) assessment. Patients with a history of venous injuries were also studied with color flow duplex venous imaging. MAIN OUTCOME MEASURES: Function of the calf muscle pump as measured by APG, and evidence of chronic venous insufficiency as measured by APG, findings on clinical examination, and by venous ultrasonography. RESULTS: Seventeen patients completed the study, including 8 with a history of vascular injuries, 6 with old fractures, and 3 who had undergone fasciotomy for soft tissue infections. The time from injury to examination ranged from 5 months to 20 years. Eight patients had signs or symptoms of venous insufficiency, the severity of which appeared to be time dependent. The APG data showed significant mean differences between fasciotomy and control extremities in ejection fraction (P<.001) and residual volume fraction (P<.001), both measures of calf muscle pump function. There were no significant changes in venous filling index, a measure of venous reflux, or in outflow fraction, which correlates with venous obstruction. There were no differences in APG variables between patients with vascular injuries vs those with orthopedic or soft tissue injuries. CONCLUSIONS: Lower extremity fasciotomy impairs long-term calf muscle pump function, as measured by APG, in patients with and without vascular injuries. These patients are at risk for the long-term development of chronic venous insufficiency following lower extremity trauma.     

Dexfentluramine in the treatment of juvenile obesity

BACKGROUND: The aim of this study was to investigate the potential of dexfenfluramine (dF) for reducing cardiovascular risk factors and improving compliance towards diet in a group of young patients hospitalized for essential obesity of high degree (BMI > or = 35). METHODS: 103 adolescents (mean age 15.4 +/- 0.2) participated in a nine-week randomized double-blind study of dF (15 mg bid) versus placebo. All patients received a VLCD (2,512 kJ/day = 600 kcal/day) for two months. In basal conditions, and after 30 and 60 days of treatment, anthropometric variables (height, weight, BMI, and W/H) and cardiovascular risk factors (blood glucose concentration, total cholesterol, HDL-cholesterol, triglycerides, systolic and diastolic blood pressure) were monitored. Modifications in hunger and satiety were also assessed. RESULTS: During the treatment period, both the dF group and the placebo group presented a similar pattern of weight loss (BMI = dF: 36.7 +/- 0.5 vs 32.5 +/- 0.4 vs 30.1 +/- 0.4; placebo: 37.0 +/- 0.6 vs 33.1 +/- 0.5 vs 30.8 +/- 0.5). No important side-effects were recorded in either group. Blood pressure and metabolic markers decreased significantly in both groups. Earlier reductions in total cholesterol and diastolic blood pressure in dF-treated subjects were the only significant differences observed as compared to the patients receiving placebo (day 30 = total cholesterol: 120 +/- 2 (dF) vs 132 +/- 3 (placebo) mg/dI; p < 0.005; diastolic blood pressure: 73 +/- 1 (dF) vs 77 +/- 1 (placebo) mmHg; p < 0.01). However, after 60 days, these values were similar in the two groups. As far as non-parametric data are concerned, dF determined a reduction in hunger and an increase in satiety in a significantly higher number of subjects than did the placebo, not only after 30 days of treatment (92.8% vs 55.3% and 92.8% vs 45.5%, respectively; p < 0.0001), but also after two months of treatment (97.8% vs 67.4% and 97.8% vs 45.8%, respectively; p < 0.0001). CONCLUSIONS: These findings demonstrate that dF represents a useful support in the treatment of juvenile obesity and might ensure a better individual compliance towards restrictive diets, particularly in the initial "critical" stages, in the absence of important side-effects.