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We develop a novel approach for pricing cyber insurance contracts. The considered cyber threats, such as viruses and worms, diffuse in a structured data network. The spread of the cyber infection is modeled by an interacting Markov chain. Conditional on the underlying infection, the occurrence and size of claims are described by a marked point process. We introduce and analyze a new polynomial approximation of claims together with a mean-field approach that allows to compute aggregate expected losses and prices of cyber insurance. Numerical case studies demonstrate the impact of the network topology and indicate that higher order approximations are indispensable for the analysis of non-linear claims.
The use of the Laser MegaJoule facility within the shock ignition scheme has been considered. In the first part of the study, one-dimensional hydrodynamic calculations were performed for an inertial confinement fusion capsule in the context of the shock ignition scheme providing the energy gain and an estimation of the increase of the peak power due to the reduction of the photon penetration expected during the high-intensity spike pulse. In the second part, we considered a Laser MegaJoule configuration consisting of 176 laser beams that have been grouped providing two different irradiation schemes. In this configuration the maximum available energy and power are 1.3 MJ and 440 TW. Optimization of the laser–capsule parameters that minimize the irradiation non-uniformity during the first few ns of the foot pulse has been performed. The calculations take into account the specific elliptical laser intensity profile provided at the Laser MegaJoule and the expected beam uncertainties. A significant improvement of the illumination uniformity provided by the polar direct drive technique has been demonstrated. Three-dimensional hydrodynamic calculations have been performed in order to analyse the magnitude of the azimuthal component of the irradiation that is neglected in two-dimensional hydrodynamic simulations.
Reconfigurable nanowire transistors provide the operation of unipolar p-type and n-type FETs freely selectable within a single device. The enhanced functionality is enabled by controlling the currents through two individually gated Schottky junctions. Here we analyze the impact of the Schottky barrier height on the symmetry of Silicon nanowire RFET transfer characteristics and their performance within circuits. Prospective simulations are carried out, indicating that germanium nanowire based RFETs of the same dimensions will show a distinctly increased performance, making them a promising material solution for future reconfigurable electronics.
To evaluate the feasibility of implementation of the refined window for routine antimicrobial prophylaxis (RAP) of 30-74 minutes before skin incision compared to the World Health Organization (WHO) standard of 0-60 minutes.
Prospective study on timing of routine antimicrobial prophylaxis in 2 different time periods.
Tertiary referral university hospital with 30,000 surgical procedures per year.
In all consecutive vascular, visceral, and trauma procedures, the timing was prospectively recorded during a first time period of 2 years (A; baseline) and a second period of 1 year (B; after intervention). An intensive intervention program was initiated after baseline. The primary outcome parameter was timing; the secondary outcome parameter was surgical site infection (SSI) rate in the subgroup of patients undergoing cholecystectomy/colon resection.
During baseline time period A (3,836 procedures), RAP was administered 30–74 minutes before skin incision in 1,750 (41.0%) procedures; during time period B (1,537 procedures), it was administered in 914 (56.0%; P < .001). The subgroup analysis did not reveal a significant difference in SSI rate.
This bundle of interventions resulted in a statistically significant improvement of timing of RAP even at a shortened window compared to the WHO standard.
MnO nanoparticles (NPs) were surface functionalized by two different approaches, (1) using a dopamine-poly(ethylene glycol) (PEG) (DA-PEG) ligand and (2) by encapsulation within a thin silica shell applying a novel approach. Both MnO@DA-PEG and MnO@SiO2 NPs exhibited excellent long-term stability in physiological solutions. In addition, the cytotoxic potential of both materials was comparatively low. Furthermore, owing to the magnetic properties of MnO NPs, both MnO@DA-PEG and MnO@SiO2 lead to a shortening of the longitudinal relaxation time T1 in MRI. In comparison to the PEGylated MnO NPs, the presence of a thin silica shell led to a greater stability of the MnO core itself by preventing excessive Mn ion leaching into aqueous solution.
As mentioned in previous chapters, CoMP has the capability to significantly enhance spectral efficiency and cell-edge throughput. However, CoMP may require additional signaling overhead on the air interface and the backhaul, in particular joint signal processing CoMP as introduced in Chapter 6. Therefore, in practice only a limited number of base stations can cooperate in order to keep the overhead manageable. This raises the question which base stations should form cooperation clusters in order to exploit the advantages of CoMP efficiently at limited complexity.
In general, one can distinguish between static and dynamic clustering algorithms. Static clusters are kept constant over time and designed based on geographical criteria as the positions of base stations and the morphology of the surroundings. In the case of dynamic clustering, the system continuously adapts the clustering strategy to changing parameters such as user equipment (UE) locations and radio frequency (RF) conditions. Here, the central question is on which information the adaptation of clusters shall be based, and where in the system clustering decisions are made.
To illustrate concrete clustering results and their corresponding performance, we use two different setups in this chapter. On one hand, we consider an idealistic setup, i.e. a hexagonal layout of up to M = 111 cells, grouped into sites of 3 cells each, with an inter-site distance (ISD) of 500 m.
Electro photography („ laser printing“) has emerged to one of the leading two-dimensional (2D) print technologies during the last decades. However, in contrast to the well-established ink jet process, the examination of three-dimensional (3D) electro photography has just been started. A newly developed non-contact fusing procedure based on click chemistry methodology has been developed to reduce the mechanical as well as thermal stress during the curing. The inorganic SiOx-coating of the toner particles has been modified for the prospective attachment of the cell-growth promoting amino acid sequence Arg-Gly-Asp (RGD) for an improved cell attachment behavior onto the hydrophobic polymeric material.
MnO nanoparticles were surface modified using two different multifunctional polymers. By introducing a PEG group, the long term stability, MRI applicability and sterile filtration could be greatly improved. Furthermore, PEGylated MnO NPs were less toxic compared to non-PEGylated NPs. The results suggest that these nanoparticles are suitable for in vivo applications.
Initiation of pathways that lead to proliferation and chemoresistance by Toll-like receptors (TLRs) is an important factor in cancer progression. Here, we show the response of human cancer cells to TLR signaling inevitably linked to tumor biology. The approach is based on tailored multifunctional magnetic nanoparticles equipped with pathogen-derived ligands (CpG) functioning as TLR agonists (molecular component) to investigate the impact of transcription factor immune activation on human cancer cells. Magnetic nanoparticles (MnO and bifunctional Au-MnO) particles were covalently coated with a multifunctional polymer, displaying no cytotoxicity, to being able to enter cells while carrying foreign DNA (unmethylated CpG) to recognize intracellular TLR 9. Both, the particle and the nucleic acid are tagged with fluorescent markers for simultaneous visualization inside the cell. Apart from optical imaging, the magnetism of the particles also allows magnetic resonance imaging of organisms.
Research has shown 1.5 minutes of surgical hand antisepsis with alcohol-based hand rub to be at least as effective under experimental conditions as the 3-minute reference disinfection recommended by European Norm 12791. The aim of the present study was to validate the effectiveness of 1.5 minutes of surgical hand antisepsis in a clinical setting by comparing the effectiveness of 1.5- and 3-minute applications of alcohol-based hand rub (45% vol/vol 2-propanol, 30% vol/vol 1-propanol, and 0.2% mecetronium ethylsulphate).
Prospective crossover trial in which each surgeon served as his or her own control, with individual randomization to the 1.5-or the 3-minute group during the first part of the trial.
Basel University Hospital, Switzerland.
Thirty-two surgeons with different levels of postdoctoral training.
We measured the bactericidal effectiveness of 1.5 minutes and 3 minutes of surgical hand antisepsis with alcohol-based hand rub by assessing the mean (± SD) log10 number of colony-forming units before the application of hand rub (baseline), after the application of hand rub (immediate effect), and after surgery (sustained effect) so as to follow European Norm 12791 as closely as possible.
The immediate mean (± SD) log10 reduction in colony-forming units (cfu) was 2.66 ±1.13 log10 cfu for the 1.5-minute group and 3.01 ±1.06 log10 cfu for the 3-minute group (P = .204). Similarly, there was no statistically significant difference between the 2 groups with respect to the sustained effect; the mean ( ± SD) log10 increase in bacterial density during surgery was 1.08 ± 1.13 log10 cfu for the 1.5-minute group and 0.95 ± 1.27 log10 cfu for the 3-minute group (P = .708). No adverse effects were recorded.
In this clinical trial, surgical hand antisepsis with alcohol-based hand rub resulted in a similar bacterial reduction, regardless of whether it was applied for 3 or 1.5 minutes, which confirms experimental data generated with healthy volunteers.
To quantify the economic burden of in-hospital surgical site infections (SSIs) at a European university hospital.
Matched case-control study nested in a prospective observational cohort study.
Basel University Hospital in Switzerland, where an average of 28,000 surgical procedures are performed per year.
All in-hospital occurrences of SSI associated with surgeries performed between January 1, 2000, and December 31, 2001, by the visceral, vascular, and traumatology divisions at Basel University Hospital were prospectively recorded. Each case patient was matched to a control patient by age, procedure code, and National Nosocomial Infection Surveillance System risk index. The case-control pairs were analyzed for differences in cost of hospital care and in provision of specialized care.
A total of 6,283 procedures were performed:187 SSIs were detected in inpatients, 168 of whom were successfully matched with a control patient. For case patients, the mean additional hospital cost was SwF19,638 (95% confidence interval [CI], SwF8,492–SwF30,784); the mean additional postoperative length of hospital stay was 16.8 days (95% CI, 13–20.6 days); and the mean additional in-hospital duration of antibiotic therapy was 7.4 days (95% CI, 5.1–9.6 days). Differences were primarily attributable to organ space SSIs (n = 76).
Ina European university hospital setting, SSIs are costly and constitute a heavy and potentially preventable burden on both patients and healthcare providers.
The simulation of distributions of financial assets is an important issue for financial institutions. If risk measures are evaluated for a simulated distribution instead of the model-implied distribution, the errors in the risk measurements need to be analyzed. For distribution-invariant risk measures which are continuous on compacts, we employ the theory of large deviations to study the probability of large errors. If the approximate risk measurements are based on the empirical distribution of independent samples, then the rate function equals the minimal relative entropy under a risk measure constraint. We solve this minimization problem explicitly for shortfall risk and average value at risk.
To investigate an outbreak of Staphylococcus aureus surgical-site infections.
Pediatric cardiothoracic surgery service of a tertiary-care university medical center.
Molecular typing was used to identify healthcare workers who carried the epidemic strain.
Three children acquired surgical-site infections caused by a single strain of S. aureus. Fourteen (25%) of the staff members in the operating room and 17 (11%) on nursing units carried the epidemic strain (P = 01). A case–control study identified 4 healthcare workers who were associated statistically with the outbreak, 2 of whom (a cardiothoracic surgeon and a perfusionist) carried the epidemic strain in their nares. The surgeon also carried the epidemic strain on his hands. Each staff member who carried the epidemic strain was treated with mupirocin; those carrying the strain on their hands were required to wash their hands with chlorhexidine. The surgeon was not allowed to perform surgery until 2 of his hand cultures did not grow S. aureus.
Only three children were infected with the epidemic strain, but it was disseminated widely among staff who cared for children who underwent cardiothoracic surgery. No additional cases were identified after staff members who carried the epidemic strain were decolonized. Both classic epidemiologic methods and molecular typing techniques were necessary to identify the source and extent of this outbreak.
To study the cost-effectiveness of vaccination for hepatitis A.
Hypothetical analysis of students currently enrolled in medical school in the United States.
A Markov-based model was developed using data from the literature, actual hospital costs, and an annual discount rate of 5%. The incidence rate was based on the lowest annual rate for the US population during the past decade.
Over the lifetimes of students currently in medical school, the model estimated that there would be 286 hepatitis A cases with four deaths and 107 lost years of life. With routine vaccination, these numbers would decrease to 17, 0.3, and 6, respectively. The costs per life-year saved and quality adjusted life-year saved were $58,000 and $47,000, respectively. Serologic screening prior to vaccination was less cost-effective than universal vaccination. If the incidence of hepatitis A was underestimated by a factor of 5, the cost per life-year saved would decrease to $5,500. If the incidence of hepatitis was underestimated by a factor of 10, vaccination would result in a net cost savings.
We conclude that the cost per life-year saved by routine hepatitis A vaccination was similar to many other standard medical modalities. For routine vaccination of medical students to be cost-saving, the incidence rate for hepatitis A must be at least 10 times higher than the rate presently reported for the general population. Serological screening prior to vaccination was not cost-effective.
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