2,087 research outputs found
A Classroom Experiment on Exchange Rate Determination with Purchasing Power Parity
We develop a classroom experiment on exchange rate determination appropriate for undergraduate courses in macroeconomics and international economics. Students represent citizens from different countries and need to obtain currency to purchase goods. By participating in a sealed bid auction to buy currency, students gain a better understanding of currency markets and the determination of exchange rates. The implicit framework for exchange rate determination is one in which prices are perfectly flexible (in the long run) so that purchasing power parity (PPP) prevails. Additional treatments allow students to examine the impact of transport costs, nontradable goods and tariffs on the exchange rate and to explore possible deviations from PPP.
Quantum confinement in Si and Ge nanostructures: Effect of crystallinity
We look at the relationship between the preparation method of Si and Ge
nanostructures (NSs) and the structural, electronic, and optical properties in
terms of quantum confinement (QC). QC in NSs causes a blue shift of the gap
energy with decreasing NS dimension. Directly measuring the effect of QC is
complicated by additional parameters, such as stress, interface and defect
states. In addition, differences in NS preparation lead to differences in the
relevant parameter set. A relatively simple model of QC, using a
`particle-in-a-box'-type perturbation to the effective mass theory, was applied
to Si and Ge quantum wells, wires and dots across a variety of preparation
methods. The choice of the model was made in order to distinguish contributions
that are solely due to the effects of QC, where the only varied experimental
parameter was the crystallinity. It was found that the hole becomes
de-localized in the case of amorphous materials, which leads to stronger
confinement effects. The origin of this result was partly attributed to
differences in the effective mass between the amorphous and crystalline NS as
well as between the electron and hole. Corrections to our QC model take into
account a position dependent effective mass. This term includes an inverse
length scale dependent on the displacement from the origin. Thus, when the
deBroglie wavelength or the Bohr radius of the carriers is on the order of the
dimension of the NS the carriers `feel' the confinement potential altering
their effective mass. Furthermore, it was found that certain interface states
(Si-O-Si) act to pin the hole state, thus reducing the oscillator strength.Comment: arXiv admin note: substantial text overlap with arXiv:1111.201
Allele specific expression analysis identifies regulatory variation associated with stress-related genes in the Mexican highland maize landrace Palomero Toluqueño.
BackgroundGene regulatory variation has been proposed to play an important role in the adaptation of plants to environmental stress. In the central highlands of Mexico, farmer selection has generated a unique group of maize landraces adapted to the challenges of the highland niche. In this study, gene expression in Mexican highland maize and a reference maize breeding line were compared to identify evidence of regulatory variation in stress-related genes. It was hypothesised that local adaptation in Mexican highland maize would be associated with a transcriptional signature observable even under benign conditions.MethodsAllele specific expression analysis was performed using the seedling-leaf transcriptome of an F1 individual generated from the cross between the highland adapted Mexican landrace Palomero Toluqueño and the reference line B73, grown under benign conditions. Results were compared with a published dataset describing the transcriptional response of B73 seedlings to cold, heat, salt and UV treatments.ResultsA total of 2,386 genes were identified to show allele specific expression. Of these, 277 showed an expression difference between Palomero Toluqueño and B73 alleles under benign conditions that anticipated the response of B73 cold, heat, salt and/or UV treatments, and, as such, were considered to display a prior stress response. Prior stress response candidates included genes associated with plant hormone signaling and a number of transcription factors. Construction of a gene co-expression network revealed further signaling and stress-related genes to be among the potential targets of the transcription factors candidates.DiscussionPrior activation of responses may represent the best strategy when stresses are severe but predictable. Expression differences observed here between Palomero Toluqueño and B73 alleles indicate the presence of cis-acting regulatory variation linked to stress-related genes in Palomero Toluqueño. Considered alongside gene annotation and population data, allele specific expression analysis of plants grown under benign conditions provides an attractive strategy to identify functional variation potentially linked to local adaptation
34587 Efficacy of ruxolitinib cream for the treatment of atopic dermatitis by anatomic region: Pooled analysis from two randomized phase 3 studies
Atopic dermatitis (AD) is a highly pruritic inflammatory skin disease. Two phase 3 studies (TRuE-AD1/TRuE-AD2) enrolled patients aged ≥12 years with AD for ≥2 years, an Investigator’s Global Assessment (IGA) score of 2/3, and 3%–20% affected body surface area. Patients (total N = 1249; median age, 32 years) were randomized (2:2:1) to twice-daily 0.75% ruxolitinib (Janus kinase [JAK] 1/JAK2 inhibitor) cream, 1.5% ruxolitinib cream, or vehicle cream for 8 weeks of double-blind treatment, and thereafter continued in a long-term, 44-week period of the studies. In this pooled analysis, mean percentage change from baseline in Eczema Area and Severity Index (EASI) anatomic region subscores is reported up to Week 8 (n = 1208). For the head and neck region, patients applying 0.75%/1.5% ruxolitinib cream (vs vehicle) achieved mean improvements of 59.3%/55.8% (vs 13.4%), 70.4%/71.3% (vs 22.4%), and 70.0%/78.7% (vs 45.0%) at Weeks 2, 4, and 8, respectively (all P \u3c.0001). Results were similar for the upper limbs region (48.5%/54.7% [vs 13.3%], 66.6%/70.3% [vs 25.0%], and 73.5%/74.9% [vs 35.1%] all P \u3c.0001). For the trunk region, patients achieved mean improvements of 49.8%/60.0% (vs 12.1%), 67.3%/73.8% (vs 15.0%), and 72.7%/81.0% (vs 15.6%) at Weeks 2, 4, and 8, respectively (all P \u3c.0001). Similar results were observed for the lower limbs region (46.0%/48.2% [vs 16.3%], 65.9%/66.2% [vs 13.9%], and 76.3%/74.9% [vs 39.8%]; all P \u3c.0001). Ruxolitinib cream was well tolerated, with an adverse event profile similar to vehicle. In summary, ruxolitinib cream demonstrated significant improvements vs vehicle in patients with AD across anatomic regions as early as Week 2
Recommended from our members
Crisaborole Ointment Improves Quality of Life of Patients with Mild to Moderate Atopic Dermatitis and Their Families.
IntroductionThe impact of crisaborole ointment, a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis (AD), on quality of life (QoL) was assessed in two identically designed phase 3 studies (AD-301: NCT02118766; AD-302: NCT02118792, both at http://www.clinicaltrials.gov ).MethodsIn both studies, patients aged ≥ 2 years with mild to moderate AD per the Investigator's Static Global Assessment were randomly assigned 2:1 to receive crisaborole or vehicle twice daily for 28 days. QoL was assessed using the Children's Dermatology Life Quality Index (CDLQI) (2-15 years), the Dermatology Life Quality Index (DLQI) (≥ 16 years), and the Dermatitis Family Impact Questionnaire (DFI) (parents/caregivers/family of patients aged 2-17 years). Established QoL score severity bands provided clinical context.ResultsGreater mean improvement in QoL was observed in crisaborole-treated patients than in vehicle-treated patients at day 29 [mean change from baseline (∆BL), CDLQI: - 4.6 vs. - 3.0; P < 0.001; DLQI: - 5.2 vs. - 3.5; P = 0.015]. At baseline, more than half the patients had a "moderate effect" or higher of AD on QoL. At day 29, there was a trend toward more crisaborole- than vehicle-treated patients having "small effect" to "no effect", The QoL of parents/caregivers/family improved more for crisaborole-treated than for vehicle-treated patients (∆BL, DFI: - 3.7 vs. - 2.7; P = 0.003).ConclusionCrisaborole treatment results in clinically meaningful improvement in QoL for patients and their parents/caregivers/families.Trial registrationAD-301: http://www.clinicaltrials.gov , NCT02118766; AD-302: http://www.clinicaltrials.gov , NCT02118792.FundingAnacor Pharmaceuticals, Inc., a wholly owned subsidiary of Pfizer Inc., New York, NY
A classroom experiment on exchange rate determination with purchasing power parity
We develop a classroom experiment on exchange rate determination appropriate for undergraduate courses in macroeconomics and international economics. Students represent citizens from different countries and need to obtain currency to purchase goods. By participating in a sealed bid auction to buy currency, students gain a better understanding of currency markets and the determination of exchange rates. The implicit framework for exchange rate determination is one in which prices are perfectly flexible (in the long run) so that purchasing power parity (PPP) prevails. Additional treatments allow students to examine the impact of transport costs, nontradable goods and tariffs on the exchange rate and to explore possible deviations from PPP
Strain-engineered diffusive atomic switching in two-dimensional crystals
Strain engineering is an emerging route for tuning the bandgap, carrier mobility, chemical reactivity and diffusivity of materials. Here we show how strain can be used to control atomic diffusion in van der Waals heterostructures of two-dimensional (2D) crystals. We use strain to increase the diffusivity of Ge and Te atoms that are confined to 5 Å thick 2D planes within an Sb[subscript 2]Te[subscript 3]–GeTe van der Waals superlattice. The number of quintuple Sb[subscript 2]Te[subscript 3] 2D crystal layers dictates the strain in the GeTe layers and consequently its diffusive atomic disordering. By identifying four critical rules for the superlattice configuration we lay the foundation for a generalizable approach to the design of switchable van der Waals heterostructures. As Sb[subscript 2]Te[subscript 3]–GeTe is a topological insulator, we envision these rules enabling methods to control spin and topological properties of materials in reversible and energy efficient ways.National Science Foundation (U.S.) (DMR-1410636 and DMR-1120901)SUTD-MIT International Design Centre (IDC) (Postdoctoral Fellowship)SUTD–MIT International Design Center (IDC) (Designer Chalcogenides IDSF1200108OH Research Project
Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition
International Journal of Exercise Science 15(2): 1366-1380, 2022. Hericium erinaceus (HE), also known as Lion’s Mane mushroom, has been found to enhance cognition and metabolic flexibility in various animal models. To date however, only four studies exist in humans and none have evaluated the effects of HE on markers of metabolic flexibility or cognitive performance. A single-blind, placebo controlled, parallel-longitudinal study was used to determine the effects of HE on markers of metabolic flexibility and cognition. Twenty-four participants completed a graded exercise test on a cycle ergometer to analyze substrate oxidation rates and markers of cardiorespiratory fitness. Additionally, two dual-task challenges consisting of a Stroop Word Challenge interspersed with a Mental Arithmetic Challenge were performed, pre-post the graded exercise test, to evaluate markers of cognition in a pre-post fatigued state. Participants were stratified into two groups, receiving either 10 g of HE per day or placebo for 4-weeks in the form of two muffins identical in taste and appearance. Repeated-measures analysis of variance were conducted to evaluate potential interactions or main effects. Although group differences were noted at baseline, there were no significant interactions or main effects observed from HE ingestion for any dependent variable (all p \u3e 0.05). Our data suggest that ingesting 10 g of HE per day for 4-weeks had no impact on metabolic flexibility and cognition in a college-age cohort. Due to the limited research on HE supplementation, future research is needed to establish an effective supplement dose and duration for potential physiological changes to be observed in humans
- …