2,611 research outputs found
Molecular manipulation in augmented reality: A user experience design applied research on new paradigms of interaction.
This thesis presents the further developments of VR CHEM (2017), a molecular manipulation software in Virtual Reality. After evaluating a shift to Augmented Reality, changing consequently the name to AR CHEM, the project focused on this technology as it offers a competitive advantage for future development, especially considering the less invasive user experience and the incoming investments in the market.
The project is developed using HoloLens and Unity 3D as a platform, as these tools are considered the state of the art for AR technologies (2018).
The thesis presents a first iteration of new paradigms of interactions in AR: the 3D user interfaces and the Platform System. While the first explore the possibility of giving information to the user through 3D models used as UI/UX indications, the second strengthen the userâs visual perception of depth in space, tying all the content to more tangible elements
Acute pancreatitis associated with everolimus after kidney transplantation: a case report
Background: Acute pancreatitis (AP) following KT is a rare and often fatal complication of the early post-transplant period. Common causative factors for AP are rare after KT; anti-rejection drugs as CyA, prednisone and MMF have been implicated, although evidence is not strong and we found no reports on possible causative role for mTOR inhibitors. Case presentation: A 55-year-old Caucasian man with end-stage renal disease due to idiopathic membrano-prolipherative glomerulonephritis underwent single kidney transplantation (KT) from cadaveric donor. Anti-rejection protocol was based on Basiliximab induction followed by prednisone and mycophenolate mophetil (MMF) and Cyclosporine; Everolimus (Eve) was scheduled to substitute MMF at week 3. At day 1 he had an asymptomatic elevation of pancreatic enzymes, spontaneously resolved. The further course was unremarkable and on day 19 he started Eve, with following asymptomatic rise in pancreatic enzymes. At day 33 the patient presented with abdominal pain and a marked elevation in serum amylase (1383 U/l) and lipase (1015 U/l), normal liver enzymes and bilirubin, no hypercalcemia, mild elevation in triglycerids; RT-PCRs for Cytomegalovirus or Epstein-Barr virus were negative. The patient had no history of alcohol abuse; ultrasound, CT and MRI found no evidence of biliary lithiasis. CT scans showed a patchy fluid collection in the pancreatic head area, consistent with idiopathic necrotizing pancreatitis. The patient was treated medically and Eve was withdrawn 1 week after. Patient underwent guided drainage of the fluid collection, but developed bacterial sepsis; surgical intervention was required with debridement of necrotic tissue, lavage and drainage; immunosuppression was totally withdrawn. Following course was complicated with multiple systemic infection. Transplantectomy for acute rejection was performed, and patient entered hemodialysis. Conclusions: Our patient had a presentation that is consistent for a causative role of Eve. A predisposing condition (acute pancreatic insult during transplant surgery) spontaneously resolved, relapsed and evolved rapidly in AP after the initiation of treatment with Eve with a consistent time latency. None of the well-known common causative factors for AP was present. We discourage the use of Eve in patients with recent episodes of sub-clinical pancreatitis, since it may represent a precipitating factor or interfere with resolution
Valuation of general GMWB annuities in a low interest rate environment
Variable annuities with Guaranteed Minimum Withdrawal Benefits (GMWB) entitle the policy holder to periodic withdrawals together with a terminal payoff linked to the performance of an equity fund. In this paper, we consider the valuation of a general class of GMWB annuities, allowing for step-up, bonus and surrender features, taking also into account mortality risk and death benefits. When dynamic withdrawals are allowed, the valuation of GMWB annuities leads to a stochastic optimal control problem, which we address here by dynamic programming techniques. Adopting a Hull-White interest rate model, correlated with the equity fund, we propose an efficient tree-based algorithm. We perform a thorough analysis of the determinants of the market value of GMWB annuities and of the optimal withdrawal strategies. In particular, we study the impact of a low/negative interest rate environment. Our findings indicate that low/negative rates profoundly affect the optimal withdrawal behaviour and, in combination with step-up and bonus features, increase significantly the fair values of GMWB annuities, which can only be compensated by large management fees
Reply to the letter of Dr Merdin
Dr Merdin kindly makes suggestions about the design of our study and asks for more information about the infectious and immunosuppressive history of our monoclonal Bâcell lymphocytosis (MBL) patients with monoclonal Bâcell lymphocytosis (MBL). In our study, we incidentally found the coexistence of five cases of MBL and monoclonal gammopathy of undetermined significance (MGUS) in a cohort of kidney transplant recipients at a median of 15 years after transplantation.1 MBL and MGUS are two preâmalignant lymphoproliferative disorders of terminally differentiated B cells. Clinically, MBL and MGUS share common features, such as an indolent course, a lateâonset age distribution, a low rate of progression and an increased susceptibility to infections. MBL and MGUS are also the precursor states of two hematologic malignancies: chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), respectively
Photometric redshifts and selection of high redshift galaxies in the NTT and Hubble Deep Fields
We present and compare in this paper new photometric redshift catalogs of the
galaxies in three public fields: the NTT Deep Field, the HDF-N and the HDF-S.
Photometric redshifts have been obtained for thewhole sample, by adopting a
minimization technique on a spectral library drawn from the Bruzual
and Charlot synthesis models, with the addition of dust and intergalactic
absorption. The accuracy, determined from 125 galaxies with known spectroscopic
redshifts, is in the redshift intervals . The global redshift distribution of I-selected galaxies shows a
distinct peak at intermediate redshifts, z~0.6 at I_{AB}<26 and z~0.8 at
I_{AB}<27.5 followed by a tail extending to z~6. We also present for the first
time the redshift distribution of the total IR-selected sample to faint limits
( and ). It is found that the number density of galaxies
at 1.25<z<1.5 is ~ 0.1 /arcmin^22 at J<=21 and ~1./arcmin^2} at J<22, and drops
to 0.3/arcmin^2 (at J<22) at 1.5<z<2. The HDFs data sets are used to compare
the different results from color selection criteria and photometric redshifts
in detecting galaxies in the redshift range 3.5<z<4.5 Photometric redshifts
predict a number of high z candidates in both the HDF-N and HDF-S that is
nearly 2 times larger than color selection criteria, and it is shown that this
is primarily due to the inclusion of dusty models that were discarded in the
original color selection criteria by Madau et al 1998. In several cases, the
selection of these objects is made possible by the constraints from the IR
bands. Finally, it is shown that galactic M stars may mimic z>5 candidates in
the HDF filter set and that the 4 brightest candidates at in the HDF-S
are indeed most likely M stars. (ABRIDGED)Comment: Version accepted on July, 20, 2000. To appear on Astronomical
Journal, Nov 2000. The data and photometric redshift catalogs presented here
are available on line at http://www.mporzio.astro.it/HIGH
A hidden Markov model for statistical arbitrage in international crude oil futures markets
In this work, we study statistical arbitrage strategies in international
crude oil futures markets. We analyse strategies that extend classical pairs
trading strategies, considering the two benchmark crude oil futures (Brent and
WTI) together with the newly introduced Shanghai crude oil futures. We document
that the time series of these three futures prices are cointegrated and we
model the resulting cointegration spread by a mean-reverting regime-switching
process modulated by a hidden Markov chain. By relying on our stochastic model
and applying online filter-based parameter estimators, we implement and test a
number of statistical arbitrage strategies. Our analysis reveals that
statistical arbitrage strategies involving the Shanghai crude oil futures are
profitable even under conservative levels of transaction costs and over
different time periods. On the contrary, statistical arbitrage strategies
involving the three traditional crude oil futures (Brent, WTI, Dubai) do not
yield profitable investment opportunities. Our findings suggest that the
Shanghai futures, which has already become the benchmark for the Chinese
domestic crude oil market, can be a valuable asset for international investors
An Application of the Harmony-Search Multi-Objective (HSMO) Optimization Algorithm for the Solution of Pump Scheduling Problemâ
Abstract In hydraulic systems, water is often pumped to reach higher elevations, so as to ensure the minimum required pressure and guarantee adequate service level. However, pumps cannot be instantly activated and people do not consume the resource in uniform mode throughout the day. To avoid direct pumping, water can be stored in tanks at a higher elevation, so that it can be supplied whenever there is a higher demand. Because of the significant costs required for pumping, energy-saving in water supply systems is one of the most challenging issues to ensure optimal management of water systems. Careful scheduling of pumping operations may lead not only to energy savings, but alsoto prevent damages, as consequence of reduction of operation times and switches. By means of computer simulation, an optimal schedule of pumps can be achieved using optimization algorithms. In this paper, a harmony-search multi-objective (HSMO) optimization approach is adapted to the pump scheduling problem. The model interfaces with the popular hydraulic solver, EPANET 2.0, to check the hydraulic constraints and to evaluate the performances of the selected schedules. Penalties are introduced in the objective function in case of violation of the hydraulic constraints. The model is applied to a case study, showing that the results are comparable with those of competitive meta-heuristic algorithms (e.g. Genetic Algorithms) and pointing out the suitability of the HSMO algorithm for pumping optimization
Pressure Ulcers due to a Tunneled Central Venous Catheter in a Patient on Chronic Maintenance Hemodialysis
We describe a rare complication given by tunneled central venous catheter (CVC) in a 95-years-old woman on chronic maintenance hemodialysis (HD)
Including Urban Metabolism Principles in Decision-Making: A Methodology for Planning Waste and Resource Management
Circular economy and urban metabolism concepts have recently received great attention both in the political and academic arenas, starting a roll-over process of the \u201ctake, make, and dispose\u201d dominant economic model that is leading to an ongoing increase of resource consumption and waste generation. However, there is a relative lack of guidelines for introducing such concepts in a decision-making process able to support the design of appropriate policies and strategies and the definition of specific actions to cope with such challenges. This paper attempts to contribute to the recent efforts at incorporating these concepts in policy and decision-making processes by providing a methodology for the development of strategic plans for waste prevention and resource management. The proposed methodology, developed within the Urban_WINS project, combines different quantitative\u2013analytical and qualitative methods and tools, together with a participatory process. The methodology was tested in eight EU cities and allowed to formulate several measures and actions aimed at addressing the challenges posed by the current consumption patterns. Moreover, the participatory approach led to the legitimization of the strategic plans, as well as to raise awareness among stakeholders. Although it might require specific tailor-made adjustments, this methodology is suitable to be replicated in other contexts
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