The Role of Complexities in Systems Engineering Cost Estimating Processes

8th Annual Conference on Systems Engineering Research (CSER) presentatio

Vaccination against hepatitis B infection in patients with end stage renal disease

ABSTRACT Background: Experience of hepatitis B vaccination in a contemporary renal replacement programme is reported. Methods: A total of 406 patients were involved: 214 on haemodialysis, 97 on continuous ambulatory peritoneal dialysis, 67 predialysis (serum creatinine >400 µmol/l), and 28 with a failing transplant. Primary vaccination comprised recombinant hepatitis B vaccine (Engerix B) 40 µg intramuscularly at 0, 1, 2, and 3 months. Booster doses were administered three monthly if anti-HBs titre was <100 IU/l. Results: Uptake of vaccine was 61% (haemodialysis 70%, continuous ambulatory peritoneal dialysis 62%, predialysis 31%, transplant 61%, p<0.0001). Primary seroconversion occurred in 64% of vaccinated patients (anti-HBs; 10-100 U/l, 33%; >100 U/l, 31%). Booster doses led to further improvement in immunity in 66/115 (57%) patients after a first and 8/20 (40%) patients after a second booster dose, but uptake was again poor (first booster 74%, second 31%). Seroprotection declined unexpectedly rapidly; after a mean of 16 months 71/115 patients (62 %) had a significant fall in their anti-HBs titres; 30/115 (26%) lost detectable antibody. Conclusions: Routine hepatitis B vaccination of patients with end stage renal failure is logistically difficult to administer on a large scale; primary seroconversion is relatively poor, but improves after repeated booster doses; protective anti-HBs titres decline rapidly, and yearly antibody checks with selective booster doses will be required to maintain seroprotection. The cost effectiveness of a vaccination programme will vary greatly depending on the prevalence of hepatitis B in the population at risk. Keyword

A simple and efficient GIS tool for volume calculations of submarine landslides

A numeric tool is presented for calculating volumes of topographic voids such as slump scars of landslides, canyons or craters (negative/concave morphology), or alternatively, bumps and hills (positive/convex morphology) by means of digital elevation models embedded within a geographical information system (GIS). In this study, it has been used to calculate landslide volumes. The basic idea is that a (singular) event (landslide, meteorite impact, volcanic eruption) has disturbed an intact surface such that it is still possible to distinguish between the former (undisturbed) landscape and the disturbance (crater, slide scar, debris avalanche). In such cases, it is possible to reconstruct the paleo-surface and to calculate the volume difference between both surfaces, thereby approximating the volume gain or loss caused by the event. I tested the approach using synthetically generated land surfaces that were created on the basis of Shuttle Radar Topography Mission data. Also, I show the application to two real cases, (1) the calculation of the volume of the Masaya Slide, a submarine landslide on the Pacific continental slope of Nicaragua, and (2) the calculation of the void of a segment of the Fish River Canyon, Namibia. The tool is provided as a script file for the free GIS GRASS. It performs with little effort, and offers a range of interpolation parameters. Testing with different sets of interpolation parameters results in a small range of uncertainty. This tool should prove useful in surface studies not exclusively on earth

Pharmacotherapy and the risk for community-acquired pneumonia

<p>Abstract</p> <p>Background</p> <p>Some forms of pharmacotherapy are shown to increase the risk of community-acquired pneumonia (CAP). The purpose of this study is to investigate whether pharmacotherapy with proton pump inhibitors (PPI), inhaled corticosteroids, and atypical antipsychotics was associated with the increased risk for CAP in hospitalized older adults with the adjustment of known risk factors (such as smoking status and serum albumin levels).</p> <p>Methods</p> <p>A retrospective case-control study of adults aged 65 years or older at a rural community hospital during 2004 and 2006 was conducted. Cases (N = 194) were those with radiographic evidence of pneumonia on admission. The controls were patients without the discharge diagnosis of pneumonia or acute exacerbation of chronic obstructive pulmonary disease (COPD) (N = 952). Patients with gastric tube feeding, ventilator support, requiring hemodialysis, metastatic diseases or active lung cancers were excluded.</p> <p>Results</p> <p>Multiple logistic regression analysis revealed that the current use of inhaled corticosteroids (adjusted odds ratio [AOR] = 2.89, 95% confidence interval [CI] = 1.56-5.35) and atypical antipsychotics (AOR = 2.26, 95% CI = 1.23-4.15) was an independent risk factor for CAP after adjusting for confounders, including age, serum albumin levels, sex, smoking status, a history of congestive heart failure, coronary artery disease, and COPD, the current use of PPI, β2 agonist and anticholinergic bronchodilators, antibiotic(s), iron supplement, narcotics, and non-steroidal anti-inflammatory drugs. The crude OR and the AOR of PPI use for CAP was 1.41 [95% CI = 1.03 - 1.93] and 1.18 [95% CI = 0.80 - 1.74] after adjusting for the above confounders, respectively. Lower serum albumin levels independently increased the risk of CAP 1.89- fold by decreasing a gram per deciliter (AOR = 2.89, 95% CI = 2.01 - 4.16).</p> <p>Conclusion</p> <p>Our study reaffirmed that the use of inhaled corticosteroids and atypical antipsychotics was both associated with an increased risk for CAP in hospitalized older adults of a rural community. No association was found between current PPI use and the risk for CAP in this patient population of our study.</p

Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy - a case series

<p>Abstract</p> <p>Introduction</p> <p>Magnetic resonance imaging (MRI) and computed tomography (CT) with ⁶⁸Ga-DOTATOC positron emission tomography (⁶⁸Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy.</p> <p>Methods</p> <p>Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and ⁶⁸Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) <it>or </it>PET, and were evaluated further. The respective findings were reviewed independently, analyzed with respect to correlations, and compared with each other.</p> <p>Results</p> <p>Within the study group, SB transgression was associated with bony changes visible by CT in 14 patients (81%). Tumorous changes of the foramen ovale and rotundum were evident in 13 and 8 cases, respectively, which were accompanied by skeletal muscular invasion in 8 lesions. We analysed six designated anatomical sites of the SB in each of the 16 patients. Of the 96 sites, 42 had infiltration that was delineable by MRI/CT and PET in 35 cases and by PET only in 7 cases. The mean infracranial volume that was delineable in PET was 10.1 ± 10.6 cm³, which was somewhat larger than the volume detectable in MRI/CT (8.4 ± 7.9 cm³).</p> <p>Conclusions</p> <p>⁶⁸Ga-DOTATOC-PET allows detection and assessment of the extent of infracranial meningioma invasion. This method seems to be useful for planning fractionated stereotactic radiation when used in addition to conventional imaging modalities that are often inconclusive in the SB region.</p

Accreting Black Holes

This chapter provides a general overview of the theory and observations of black holes in the Universe and on their interpretation. We briefly review the black hole classes, accretion disk models, spectral state classification, the AGN classification, and the leading techniques for measuring black hole spins. We also introduce quasi-periodic oscillations, the shadow of black holes, and the observations and the theoretical models of jets.Comment: 41 pages, 18 figures. To appear in "Tutorial Guide to X-ray and Gamma-ray Astronomy: Data Reduction and Analysis" (Ed. C. Bambi, Springer Singapore, 2020). v3: fixed some typos and updated some parts. arXiv admin note: substantial text overlap with arXiv:1711.1025

Apoptosis assays with lymphoma cell lines: problems and pitfalls

Much attention has been focused on the manner in which tumour cells die after treatment with cytotoxic agents. The basic question is whether cells die via apoptosis or via direct damage from the toxic agent. Various assays have been used to make this distinction. However, we show herein that some of the widely used assays for apoptosis do not in fact distinguish between apoptosis and other forms of cell death. More specifically: (1) A sub-G1 DNA content, identified by propidium iodide staining, does not distinguish between apoptotic and necrotic cells; (2) loss of mitochondrial membrane potential does not distinguish between apoptotic and necrotic cells, unless combined with an assay for an intact cell membrane; (3) subcellular fragments that arise from dead cells or from apoptotic bodies can interfere with some assays for apoptosis such as annexin V staining, as they may be close to the size of intact cells, making it difficult to decide where to set the size threshold; (4) irradiated cells display a large increase in nonspecific Ab binding. This may be partly due to an increase in cell size, but, regardless of the cause, it can lead to a mistaken conclusion that there is an increase in a particular antigen if appropriate control reagents are not tested; and (5) experiments utilising Ab crosslinking have neglected the role of cell aggregation, which can cause multiple problems including death from mechanical stress when cells are handled. Consideration of these factors will improve our ability to determine the mode of cell death

Pleosporales

One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae

The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

An ALS-Linked Mutant SOD1 Produces a Locomotor Defect Associated with Aggregation and Synaptic Dysfunction When Expressed in Neurons of Caenorhabditis elegans

The nature of toxic effects exerted on neurons by misfolded proteins, occurring in a number of neurodegenerative diseases, is poorly understood. One approach to this problem is to measure effects when such proteins are expressed in heterologous neurons. We report on effects of an ALS-associated, misfolding-prone mutant human SOD1, G85R, when expressed in the neurons of Caenorhabditis elegans. Stable mutant transgenic animals, but not wild-type human SOD1 transgenics, exhibited a strong locomotor defect associated with the presence, specifically in mutant animals, of both soluble oligomers and insoluble aggregates of G85R protein. A whole-genome RNAi screen identified chaperones and other components whose deficiency increased aggregation and further diminished locomotion. The nature of the locomotor defect was investigated. Mutant animals were resistant to paralysis by the cholinesterase inhibitor aldicarb, while exhibiting normal sensitivity to the cholinergic agonist levamisole and normal muscle morphology. When fluorescently labeled presynaptic components were examined in the dorsal nerve cord, decreased numbers of puncta corresponding to neuromuscular junctions were observed in mutant animals and brightness was also diminished. At the EM level, mutant animals exhibited a reduced number of synaptic vesicles. Neurotoxicity in this system thus appears to be mediated by misfolded SOD1 and is exerted on synaptic vesicle biogenesis and/or trafficking