Computation of Equilibria in OLGModels with Many Heterogeneous Households

This paper develops a decomposition algorithm by which a market economy with many households may be solved through the computation of equilibria for a sequence of representative agent economies. The paper examines local and global convergence properties of the sequential recalibration (SR) algorithm. SR is then demonstrated to efficiently solve Auerbach- Kotlikoff OLG models with a large number of heterogeneous households. We approximate equilibria in OLG models by solving a sequence of related Ramsey optimal growth problems. This approach can provide improvements in both efficiency and robustness as compared with simultaneous solution methods.Computable general equilibrium, Overlapping generations, Microsimulation, Sequential recalibration

Computation of Equilibria in OLG Models with Many Heterogeneous Households

This paper develops a decomposition algorithm by which a market economy with many households may be solved through the computation of equilibria for a sequence of representative agent economies. The paper examines local and global convergence properties of the sequential recalibration (SR) algorithm. SR is then demonstrated to efficiently solve Auerbach-Kotlikoff OLG models with a large number of heterogeneous households. We approximate equilibria in OLG models by solving a sequence of related Ramsey optimal growth problems.This approach can provide improvements in both efficiency and robustness as compared with simultaneous solution-methods.Computable general equilibrium, overlapping generations, microsimulation, sequential recalibration

Purine analog substitution of the HIV-1 polypurine tract primer defines regions controlling initiation of plus-strand DNA synthesis

Despite extensive study, the mechanism by which retroviral reverse transciptases (RTs) specifically utilize polypurine tract (PPT) RNA for initiation of plus-strand DNA synthesis remains unclear. Three sequence motifs within or adjacent to the purine-rich elements are highly conserved, namely, a rU:dA tract region immediately 5′ to the PPT, an rA:dT-rich sequence constituting the upstream portion of the PPT and a downstream rG:dC tract. Using an in vitro HIV-1 model system, we determined that the former two elements define the 5′ terminus of the (+)-strand primer, whereas the rG:dC tract serves as the primary determinant of initiation specificity. Subsequent analysis demonstrated that G→A or A→G substitution at PPT positions −2, −4 and +1 (relative to the scissile phosphate) substantially reduces (+)-strand priming. We explored this observation further using PPT substrates substituted with a variety of nucleoside analogs [inosine (I), purine riboside (PR), 2-aminopurine (2-AP), 2,6-diaminopurine (2,6-DAP), isoguanine (iG)], or one of the naturally occurring bases at these positions. Our results demonstrate that for PPT positions −2 or +1, substituting position 2 of the purine was an important determinant of cleavage specificity. In addition, cleavage specificity was greatly affected by substituting −4G with an analog containing a 6-NH2 moiety

The Drivers of Sustainable Apparel and Sportswear Consumption : A Segmented Kano Perspective

The steady increase of sustainable consumer behavior leads companies to strengthen their efforts to become socially and ecologically more sustainable. Particularly in the clothing and footwear industry, more and more companies are aware of their need to fundamentally adapt the way they create value. Sustainability offerings are developed, e.g., usage of upcycled materials (e.g., ocean plastic), circular business models (e.g., decomposition of returned products into components for new ones), as well as adapted product ranges (e.g., smaller or with fewer fashion cycles). However, it is frequently unclear in advance, which offerings will increase (or decrease) satisfaction and, consequently, drive (or not drive) sustainable consumption. The application of a segmented Kano perspective in an apparel and sportswear context that helps to answer these questions is presented: 17 potential offerings were assessed by a sample of 490 consumers. Our analysis demonstrates the usefulness of this methodology and that returning used products (to recycle them), discounts for buying sustainable products, sustainability level indicators, and biobased materials are highly attractive. However, the responsiveness varies across the derived consumer segments, from being decisive or attractive to indifferent or reverse. As assumed, gender and attitude towards sustainability are good predictors for segment membership

Ground-State SiO Maser Emission Toward Evolved Stars

We have made the first unambiguous detection of vibrational ground-state maser emission from SiO toward six evolved stars. Using the Very Large Array, we simultaneously observed the v=0, J=1-0, 43.4-GHz, ground-state and the v=1, J=1-0, 43.1-GHz, first excited-state transitions of SiO toward the oxygen-rich evolved stars IRC+10011, o Ceti, W Hya, RX Boo, NML Cyg, and R Cas and the S-type star chi Cyg. We detected at least one v=0 SiO maser feature from six of the seven stars observed, with peak maser brightness temperatures ranging from 10,000 K to 108,800 K. In fact, four of the seven v=0 spectra show multiple maser peaks, a phenomenon which has not been previously observed. Ground-state thermal emission was detected for one of the stars, RX Boo, with a peak brightness temperature of 200 K. Comparing the v=0 and the v=1 transitions, we find that the ground-state masers are much weaker with spectral characteristics different from those of the first excited-state masers. For four of the seven stars the velocity dispersion is smaller for the v=0 emission than for the v=1 emission, for one star the dispersions are roughly equivalent, and for two stars (one of which is RX Boo) the velocity spread of the v=0 emission is larger. In most cases, the peak flux density in the v=0 emission spectrum does not coincide with the v=1 maser peak. Although the angular resolution of these VLA observations were insufficient to completely resolve the spatial structure of the SiO emission, the SiO spot maps produced from the interferometric image cubes suggest that the v=0 masers are more extended than their v=1 counterparts

Analysis of Cognitive Deficits of Concussion Patients: Dual Task, Motor Cognition, and Memory

The severity of a concussion is determined by the magnitude of the force of impact and the symptoms expressed post-injury. The most current and widely used test to identify a concussion in college athletics is called the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT). It is a computerized neurocognitive test battery that measures different cognitive abilities and compares baseline with post-injury results. In the current study we formulated a series of physical and psychological cognition tests that measure similar cognitive abilities as the ImPACT. The purpose of this study is to demonstrate that physical tests paired with neurocognitive tests are a better determinate of post-concussion symptoms in athletes than a sedentary neurocognitive battery test alone. Such tests included balance, memory, spatial relations, attention and reaction time. Three different groups of post-concussed history were statistically compared. Group one (controls), consisted of participants with no previous history of a concussion (n=32). Group two (concussed), consisted of participants with a concussion in the past three months and who had recently been cleared to resume full sports activities (n=11). Group three (multiple concussed), consisted of participants with at least five concussions in their lifespan (n=7). A one-way ANOVA and two-tailed independent t-test were ran to observe any differences in tests between groups (

Viroporin potential of the lentivirus lytic peptide (LLP) domains of the HIV-1 gp41 protein

<p>Abstract</p> <p>Background</p> <p>Mechanisms by which HIV-1 mediates reductions in CD4+ cell levels in infected persons are being intensely investigated, and have broad implications for AIDS drug and vaccine development. Virally induced changes in membrane ionic permeability induced by lytic viruses of many families contribute to cytopathogenesis. HIV-1 induces disturbances in plasma membrane ion transport. The carboxyl terminus of TM (gp41) contains potential amphipathic α-helical motifs identified through their structural similarities to naturally occurring cytolytic peptides. These sequences have been dubbed lentiviral lytic peptides (LLP) -1, -2, and -3.</p> <p>Results</p> <p>Peptides corresponding to the LLP domains (from a clade B virus) partition into lipid membranes, fold into α-helices and disrupt model membrane permeability. A peptide corresponding to the LLP-1 domain of a clade D HIV-1 virus, LLP-1D displayed similar activity to the LLP-1 domain of the clade B virus in all assays, despite a lack of amino acid sequence identity.</p> <p>Conclusion</p> <p>These results suggest that the C-terminal domains of HIV-1 Env proteins may form an ion channel, or viroporin. Increased understanding of the function of LLP domains and their role in the viral replication cycle could allow for the development of novel HIV drugs.</p

Re-Engineering of the CERN Accelerators and Services Control System based on VMEbus and PowerPC Technology

A new generation of PowerPC VMEbus front-end computers is being introduced in the CERN accelerators and services control system infrastructure. This new technology is aimed at replacing existing PC based front-end computers and at offering a high performance microprocessor platform for present and future engineering developments for the LHC era. This paper describes the re-engineering strategy and the core architecture of the new systems. Special performance issues are also addressed in this paper