Interpolatory Weighted-H2 Model Reduction

This paper introduces an interpolation framework for the weighted-H2 model reduction problem. We obtain a new representation of the weighted-H2 norm of SISO systems that provides new interpolatory first order necessary conditions for an optimal reduced-order model. The H2 norm representation also provides an error expression that motivates a new weighted-H2 model reduction algorithm. Several numerical examples illustrate the effectiveness of the proposed approach

Support for graphicacy: a review of textbooks available to accounting students

This Teaching Note reports on the support available in textbooks for graphicacy that will help students understand the complexities of graphical displays. Graphical displays play a significant role in financial reporting, and studies have found evidence of measurement distortion and selection bias. To understand the complexities of graphical displays, students need a sound understanding of graphicacy and support from the textbooks available to them to develop that understanding. The Teaching Note reports on a survey that examined the textbooks available to students attending two Scottish universities. The support of critical graphicacy skills was examined in conjunction with textbook characteristics. The survey, which was not restricted to textbooks designated as required reading, examined the textbooks for content on data measurement and graphical displays. The findings highlight a lack of support for graphicacy in the textbooks selected. The study concludes that accounting educators need to scrutinize more closely the selection of textbooks and calls for more extensive research into textbooks as a pedagogic tool

Demonstration of improved sensitivity of echo interferometers to gravitational acceleration

We have developed two configurations of an echo interferometer that rely on standing wave excitation of a laser-cooled sample of rubidium atoms that measures acceleration. For a two-pulse configuration, the interferometer signal is modulated at the recoil frequency and exhibits a sinusoidal frequency chirp as a function of pulse spacing. For a three-pulse stimulated echo configuration, the signal is observed without recoil modulation and exhibits a modulation at a single frequency. The three-pulse configuration is less sensitive to effects of vibrations and magnetic field curvature leading to a longer experimental timescale. For both configurations of the atom interferometer (AI), we show that a measurement of acceleration with a statistical precision of 0.5% can be realized by analyzing the shape of the echo envelope that has a temporal duration of a few microseconds. Using the two-pulse AI, we obtain measurements of acceleration that are statistically precise to 6 parts per million (ppm) on a 25 ms timescale. Using the three-pulse AI, we obtain measurements of acceleration that are statistically precise to 0.4 ppm on a timescale of 50 ms. A further statistical enhancement is achieved by analyzing the data across the echo envelope to improve the statistical precision to 75 parts per billion (ppb). We discuss methods for reducing prominent systematic effects due to a magnetized vacuum chamber and improving the signal-to-noise ratio. Simulations of both AI configurations with a timescale of 300 ms reached in a non-magnetic vacuum chamber suggest that an optimized experiment with improved vibration isolation and atoms selected in the mF = 0 state can result in measurements of g statistically precise to 0.3 pbb for the two-pulse AI and 0.6 ppb for the three-pulse AI.Comment: 17 pages, 9 figures, 3 table

Transverse Demagnetization Dynamics of a Unitary Fermi Gas

Understanding the quantum dynamics of strongly interacting fermions is a problem relevant to diverse forms of matter, including high-temperature superconductors, neutron stars, and quark-gluon plasma. An appealing benchmark is offered by cold atomic gases in the unitary limit of strong interactions. Here we study the dynamics of a transversely magnetized unitary Fermi gas in an inhomogeneous magnetic field. We observe the demagnetization of the gas, caused by diffusive spin transport. At low temperatures, the diffusion constant saturates to the conjectured quantum-mechanical lower bound $\simeq \hbar/m$, where $m$ is the particle mass. The development of pair correlations, indicating the transformation of the initially non-interacting gas towards a unitary spin mixture, is observed by measuring Tan's contact parameter.Comment: 8 pages, 6 figures. Accepted versio

Violence against female sex workers in Karnataka state, south India: impact on health, and reductions in violence following an intervention program.

ABSTRACT: BACKGROUND: Violence against female sex workers (FSWs) can impede HIV prevention efforts and contravenes their human rights. We developed a multi-layered violence intervention targeting policy makers, secondary stakeholders (police, lawyers, media), and primary stakeholders (FSWs), as part of wider HIV prevention programming involving >60,000 FSWs in Karnataka state. This study examined if violence against FSWs is associated with reduced condom use and increased STI/HIV risk, and if addressing violence against FSWs within a large-scale HIV prevention program can reduce levels of violence against them. METHODS: FSWs were randomly selected to participate in polling booth surveys (PBS 2006-2008; short behavioural questionnaires administered anonymously) and integrated behavioural-biological assessments (IBBAs 2005-2009; administered face-to-face). RESULTS: 3,852 FSWs participated in the IBBAs and 7,638 FSWs participated in the PBS. Overall, 11.0% of FSWs in the IBBAs and 26.4% of FSWs in the PBS reported being beaten or raped in the past year. FSWs who reported violence in the past year were significantly less likely to report condom use with clients (zero unprotected sex acts in previous month, 55.4% vs. 75.5%, adjusted odds ratio (AOR) 0.4, 95% confidence interval (CI) 0.3 to 0.5, p < 0.001); to have accessed the HIV intervention program (ever contacted by peer educator, 84.9% vs. 89.6%, AOR 0.7, 95% CI 0.4 to 1.0, p = 0.04); or to have ever visited the project sexual health clinic (59.0% vs. 68.1%, AOR 0.7, 95% CI 0.6 to 1.0, p = 0.02); and were significantly more likely to be infected with gonorrhea (5.0% vs. 2.6%, AOR 1.9, 95% CI 1.1 to 3.3, p = 0.02). By the follow-up surveys, significant reductions were seen in the proportions of FSWs reporting violence compared with baseline (IBBA 13.0% vs. 9.0%, AOR 0.7, 95% CI 0.5 to 0.9 p = 0.01; PBS 27.3% vs. 18.9%, crude OR 0.5, 95% CI 0.4 to 0.5, p < 0.001). CONCLUSIONS: This program demonstrates that a structural approach to addressing violence can be effectively delivered at scale. Addressing violence against FSWs is important for the success of HIV prevention programs, and for protecting their basic human rights

Development and validation of a new tool to measure the facilitators, barriers and preferences to exercise in people with osteoporosis

Abstract Background Despite the widely known benefits of exercise and physical activity, adherence rates to these activities are poor. Understanding exercise facilitators, barriers, and preferences may provide an opportunity to personalize exercise prescription and improve adherence. The purpose of this study was to develop the Personalized Exercise Questionnaire (PEQ) to identify these facilitators, barriers, and preferences to exercise in people with osteoporosis. Methods This study comprises two phases, instrument design and judgmental evidence. A panel of 42 experts was used to validate the instrument through quantitative (content validity) and qualitative (cognitive interviewing) methods. Content Validity Index (CVI) is the most commonly used method to calculate content validity quantitatively. There are two kinds of CVI: Item-CVI (I-CVI) and Scale-level CVI (S-CVI). Results Preliminary versions of this tool showed high content validity of individual items (I-CVI range: 0.50 to 1.00) and moderate to high overall content validity of the PEQ (S-CVI/UA = 0.63; S-CVI/Ave = 0.91). Through qualitative methods, items were improved until saturation was achieved. The tool consists of 6 domains and 38 questions. The 6 domains are: 1) support network; 2) access; 3) goals; 4) preferences; 5) feedback and tracking; and 6) barriers. There are 35 categorical questions and 3 open-ended items. Conclusions Using an iterative approach, the development and evaluation of the PEQ demonstrated high item-content validity for assessing the facilitators, barriers, and preferences to exercise in people with osteoporosis. Upon further validation it is expected that this measure might be used to develop more client-centered exercise programs, and potentially improve adherence

Coherent Behavior and Nonmagnetic Impurity Effects of the Spin Disordered State in NiGa2_2S4_4

Nonmagnetic impurity effects of the spin disordered state in the triangular antiferromagnet NiGa$_2$S$_4$ was studied through magnetic and thermal measurements for Ni$_{1-x}$Zn$_x$Ga$_2$S$_4$ (0.0\le x\le 0.3). Only 1 % substitution is enough to strongly suppress the coherence observed in the spin disordered state. However, the suppression is not complete and the robust feature of the T^2 dependent specific heat and its scaling behavior with the Weiss temperature indicate the existence of a coherent Nambu-Goldstone mode. Absence of either conventional magnetic order or bulk spin freezing suggests a novel symmetry breaking of the ground state.Comment: 4 pages, 4 figure

Hulless barley (Hordeum vulgare l.) with altered starch traits: rumen degradation kinetics

Non-Peer ReviewedThe objective of this study was to determine the effect of new hulless barley lines (zero-amylose waxy, CDC Fibar; 5%-amylose waxy, CDC Rattan; normal-amylose, CDC McGwire and high-amylose, HB08302) on rumen degradation kinetics and in vitro intestinal nutrient digestion with CDC Copeland included as a hulled control. Three dry Holstein cows fitted with rumen cannula were used for measuring rumen degradation of barley varieties. The estimation of intestinal digestion was determined by a modification of the three-step in vitro procedure described by Calsamiglia and Stern with duplicate of each in situ residue. Among the hulless barley lines, CDC Rattan was greater (P<0.05) in effectively degradable starch (EDST: 461 g/kg DM) but reduced (P<0.05) in rumen undegradable protein (RUP: 55g/kg DM) while CDC Fibar was greater (P<0.05) in effectively degradable crude protein (EDCP: 90 g/kg DM) and total digestible protein (TDP: 147 g/kg DM) than other hulless barley lines. CDC McGwire showed greater (P<0.05) in total digestible bypass starch (TDST: 590 g/kg DM), effectively degradable CHO (EDCHO: 581 g/kg DM) and total digestible CHO (TDCHO: 600 g/kg DM) than other hulless barley lines but no significant difference compared to CDC Copeland (P>0.05). HB08302 was greater (P<0.05) in rumen bypass starch (BST: 218 g/kg DM vs. 146 g/kg DM and 155 g/kg DM) and effective degradable NDF (EDNDF: 74 g/kg DM vs. 49 g/kg DM and 52 g/kg DM) than CDC Fibar and CDC Rattan. HB08302 was also greater in total digestible NDF (TDNDF: 93 g/kg DM vs. 62 g/kg DM and 67 g/kg DM) and intestinal digestible rumen bypass starch (IDBST: 180 g/kg DM vs. 122 g/kg DM and 130 g/kg DM) compared to CDC Fibar and CDC McGwire. HB08302 also showed greater (P<0.05) in bypass CHO (BCHO: 179 g/kg DM) and intestinal digestible bypass CHO (IDBCHO: 31 g/kg DM) than other hulless barley lines. Amylose and amylopectin were significantly correlated (P<0.001) to EDCP (r=-0.71, r=0.64) and TDP (r=-0.85; r=0.77), while amylose, ratio of amylose and amylopectin were positively correlated (P<0.01) to EDNDF, TDNDF, BST, IDBST and TDCHO (P<0.05). BCP, IDP, TDP, BNDF were positively correlated to beta-glucan levels (P<0.001) while EDST, TDST, EDCHO and TDCHO were negatively correlated to beta-glucan levels in hulless barley lines (P<0.01). in conclusion hulless barley lines with altered carbohydrate traits have the potential to increase rumen and intestinal nutrient availability to ruminants. Altered beta-glucan levels had a greater effect on rumen carbohydrates and crude protein degradation than altered starch traits