The Process of Pension Forecasting

This paper explains the process of pension forecasting. It discusses the common purposes and uses of pension forecasts, the major steps involved, and the principal limitations of these forecasts. Some insights into each stage of the forecasting process are provided. Among the stages discussed are: the background research to be performed; the selection of scenario assumptions; shortcuts used in the actual performance of the forecast; review of the forecast results; and communication of the forecast findings

A note on the perturbation of positive matrices by normal and unitary matrices

AbstractIn a recent paper, Neumann and Sze considered for an n×n nonnegative matrix A, the minimization and maximization of ρ(A+S), the spectral radius of (A+S), as S ranges over all the doubly stochastic matrices. They showed that both extremal values are always attained at an n×n permutation matrix. As a permutation matrix is a particular case of a normal matrix whose spectral radius is 1, we consider here, for positive matrices A such that (A+N) is a nonnegative matrix, for all normal matrices N whose spectral radius is 1, the minimization and maximization problems of ρ(A+N) as N ranges over all such matrices. We show that the extremal values always occur at an n×n real unitary matrix. We compare our results with a less recent work of Han, Neumann, and Tastsomeros in which the maximum value of ρ(A+X) over all n×n real matrices X of Frobenius norm n was sought

Economic burden of adverse drug reactions and potential for pharmacogenomic testing in Singaporean adults.

Adverse drug reactions (ADRs) contribute to hospitalization but data on its economic burden is scant. Pre-emptive pharmacogenetic (PGx) testing can potentially reduce ADRs and its associated costs. The objectives of this study were to quantify the economic burden of ADRs and to estimate the breakeven cost of pre-emptive PGx testing in Singapore. We collected itemized costs for 1000 random non-elective hospitalizations of adults admitted to a tertiary-care general hospital in Singapore. The presence of ADRs at admission and their clinical characteristics were reported previously. The economic burden of ADRs was assessed from two perspectives: (1) Total cost and (2) incremental costs. The breakeven cost of PGx testing was estimated by dividing avoidable hospitalization costs for ADRs due to selected drugs by the number of patients taking those drugs. The total cost of 81 admissions caused by ADRs was US$570,404. Costs were significantly higher for bleeding/elevated international normalized ratio (US$9906 vs. US$2251, p = 6.58 × 10-3) compared to other ADRs, and for drugs acting on the blood coagulation system (US$9884 vs. US$2229, p = 4.41 × 10-3) compared to other drug classes. There were higher incremental laboratory costs due to ADRs causing or being present at admission. The estimated breakeven cost of a pre-emptive PGx test for patients taking warfarin, clopidogrel, chemotherapeutic and neuropsychiatric drugs was US$114 per patient. These results suggest that future studies designed to directly measure the clinical and cost impact of a pre-emptive genotyping program will help inform clinical practice and health policy decisions

Towards a better understanding of the evolution of specialized parasites of fungus-growing ant crops

Fungus-growing ants have interacted and partly coevolved with specialised microfungal parasites of the genus Escovopsis since the origin of ant fungiculture about 50 million years ago. Here, we review the recent progress in understanding the patterns of specificity of this ant-parasite association, covering both the colony/population level and comparisons between phylogenetic clades. We use a modified version of Tinbergen's four categories of evolutionary questions to structure our review in complementary approaches addressing both proximate questions of development and mechanism, and ultimate questions of (co)adaptation and evolutionary history. Using the same scheme, we identify future research questions that are likely to be particularly illuminating for understanding the ecology and evolution of Escovopsis parasitism of the cultivar maintained by fungus-growing ants

GOES-R Algorithms: A Common Science and Engineering Design and Development Approach for Delivering Next Generation Environmental Data Products

GOES-R, the next generation of the National Oceanic and Atmospheric Administration’s (NOAA) Geostationary Operational Environmental Satellite (GOES) System, represents a new technological era in operational geostationary environmental satellite systems. GOES-R will provide advanced products that describe the state of the atmosphere, land, oceans, and solar/ space environments over the western hemisphere. The Harris GOES-R Ground Segment team will provide the software, based on government-supplied algorithms, and engineering infrastructures designed to produce and distribute these next-generation data products. The Harris GOES-R Team has adopted an integrated applied science and engineering approach that combines rigorous system engineering methods, with modern software design elements to facilitate the transition of algorithms for Level 1 and 2+ products to operational software. The Harris Team GOES-R GS algorithm framework, which includes a common data model interface, provides general design principles and standardized methods for developing general algorithm services, interfacing to external data, generating intermediate and L1b and L2 products and implementing common algorithm features such as metadata generation and error handling. This work presents the suite of GOES-R products, their properties and the process by which the related requirements are maintained during the complete design/development life-cycle. It also describes the algorithm architecture/engineering approach that will be used to deploy these algorithms, and provides a preliminary implementation road map for the development of the GOES-R GS software infrastructure, and a view into the integration of the framework and data model into the final design

Photochemistry of the Venus Atmosphere

Carbon monoxide, produced in the Venus atmosphere by photolysis of CO_2, is removed mainly by reaction with OH. The radical OH is formed in part by photolysis of H_2O_2, in part by reaction of O with HO_2. Photolysis of HCl provides a major source of H radicals near the visible clouds of Venus and plays a major role in the overall photochemistry. The mixing ratio of O_2 is estimated to be approximately 10^(−7), about a factor of 10 less than a recent observational upper limit reported by Traub and Carleton. A detailed model, which accounts for the photochemical stability of Venus CO_2, is presented and discussed

Comparison of Seven Extraction Kits for Detection of SARS-CoV-2 in Wastewater

Wastewater-based epidemiology (WBE) has been used to trace outbreaks and monitor populations for pathogenic viruses such as poliovirus. SARS-CoV-2 has been identified as a candidate for WBE as the virus can survive for prolonged periods in wastewater. The use of commercial extraction kits alongside polyethylene glycol separation, electrostatic membrane filtration, and ultracentrifugation have been used to analyze wastewater. However, the most consistent and versatile commercial kit has not been identified. In this study, previously analyzed wastewater was extracted using seven different commercial kits and quantified using cycle threshold (CT) values from PCR. Data was analyzed using ANOVA and pairwise comparisons at 95% confidence. Results reveal the use of ThermoFisher MagMax Microbiome Kit alongside proteinase K to be the most consistent kit when analyzing soil samples. Qiagen’s EnvironWater kit was identified as the kit of choice for liquid samples. ZymoBIOMICS DNA/RNA kit was identified as a versatile kit for analyzing both solids and liquids. Liquids were found to have higher quantities of virus on average, but solids had lower CT values on average. We conclude that isolating solids should be the primary focus when concentrating virus. MagMax Microbiome Kit with proteinase K was identified as the most consistent and accurate kit for analyzing wastewater. The MagMax Microbiome Kit was found to have significantly lower CT values when compared to other kits across all viral concentrations and sample types. The method used to concentrate water is inexpensive and uses less resources compared to previous methods, which allows WBE to be used at a larger scale in more areas. This will be important for monitoring SARS-CoV-2 variants and population health as the pandemic progresses. Further studies should focus on the efficiency of the kits when using a spiked positive control as well as variance between water samples.https://digitalcommons.unmc.edu/surp2021/1031/thumbnail.jp

Magnetization dynamics and its scattering mechanism in thin CoFeB films with interfacial anisotropy

Studies of magnetization dynamics have incessantly facilitated the discovery of fundamentally novel physical phenomena, making steady headway in the development of magnetic and spintronics devices. The dynamics can be induced and detected electrically, offering new functionalities in advanced electronics at the nanoscale. However, its scattering mechanism is still disputed. Understanding the mechanism in thin films is especially important, because most spintronics devices are made from stacks of multilayers with nanometer thickness. The stacks are known to possess interfacial magnetic anisotropy, a central property for applications, whose influence on the dynamics remains unknown. Here, we investigate the impact of interfacial anisotropy by adopting CoFeB/MgO as a model system. Through systematic and complementary measurements of ferromagnetic resonance (FMR), on a series of thin films, we identify narrower FMR linewidths at higher temperatures. We explicitly rule out the temperature dependence of intrinsic damping as a possible cause, and it is also not expected from existing extrinsic scattering mechanisms for ferromagnets. We ascribe this observation to motional narrowing, an old concept so far neglected in the analyses of FMR spectra. The effect is confirmed to originate from interfacial anisotropy, impacting the practical technology of spin-based nanodevices up to room temperature.Comment: 23 pages,3 figure

Bromine-Chlorine Coupling in the Antarctic Ozone Hole

The contribution from the chlorine and bromine species in the formation of the Antarctic ozone hole is evaluated. Since chlorine and bromine compounds are of different industrial origin, it is desirable, from a policy point of view, to be able to attribute chlorine-catalyzed loss of ozone with those reactions directly involving chlorine species, and likewise for bromine-catalyzed loss. In the stratosphere, however, most of the chemical families are highly coupled, and, for example, changes in the chlorine abundance will alter the partitioninig in other families and thus the rate of ozone loss. This modeling study examines formation of the Antarctic ozone hole for a wide range of bromine concentrations (5 - 25 pptv) and for chlorine concentrations typical of the last two decades (1.5, 2.5 and 3.5 ppbv). We follow the photochemical evolution of a single parcel of air, typical of the inner Antarctic vortex (50 mbar, 70 deg. S, NO(sub y) = 2 ppbv, with Polar Stratospheric Clouds(PSC)) from August 1 to November 1. For all of these ranges of chlorine and bromine loading, we would predict a substantial ozone hole (local depletion greater than 90%) within the de-nitrified, PSC- perturbed vortex. The contributions of the different catalytic cycles responsible for ozone loss are tabulated. The deep minimum in ozone is driven primarily by the chlorine abundance. As bromine levels decrease, the magnitude of the chlorine-catalyzed ozone loss increases to take up the slack. This is because bromine suppresses ClO by accelerating the conversion of ClO an Cl2O2 back to HCI. For this range of conditions, the local relative efficiency of ozone destruction per bromine atom to that per chlorine atom (alpha-factor) ranges from 33 to 55, decreasing with increase of bromine