Ga NMR study of the local susceptibility in SrCr8Ga4O19: pseudogap and paramagnetic defects

We present the first Ga(4f) NMR study of the Cr susceptibility in the archetype of Kagome based frustrated antiferromagnets, SrCr$_{8}$Ga$_{4}$O$_{19}$. Our major finding is that the susceptibility of the frustrated lattice goes through a maximum around 50 K. Our data also supports the existence of paramagnetic ``clusters'' of spins, responsible for the Curie behavior observed in the macroscopic susceptibility at low T. These results set novel features for the constantly debated physics of geometrically frustrated magnets.Comment: 4 pages, 5 figures Submitted to Phys. Rev. Let

Practical Layout-Aware Analog/Mixed-Signal Design Automation with Bayesian Neural Networks

The high simulation cost has been a bottleneck of practical analog/mixed-signal design automation. Many learning-based algorithms require thousands of simulated data points, which is impractical for expensive to simulate circuits. We propose a learning-based algorithm that can be trained using a small amount of data and, therefore, scalable to tasks with expensive simulations. Our efficient algorithm solves the post-layout performance optimization problem where simulations are known to be expensive. Our comprehensive study also solves the schematic-level sizing problem. For efficient optimization, we utilize Bayesian Neural Networks as a regression model to approximate circuit performance. For layout-aware optimization, we handle the problem as a multi-fidelity optimization problem and improve efficiency by exploiting the correlations from cheaper evaluations. We present three test cases to demonstrate the efficiency of our algorithms. Our tests prove that the proposed approach is more efficient than conventional baselines and state-of-the-art algorithms.Comment: Accepted to the 42nd International Conference on Computer-Aided Design (ICCAD 2023); 8 pages, 8 figure

Regulating the Energy Flow in a Cyanobacterial Light Harvesting Antenna Complex

Photosynthetic organisms harvest light energy, utilizing the absorption and energy transfer properties of protein-bound chromophores. Controlling the harvesting efficiency is critical for the optimal function of the photosynthetic apparatus. Here, we show that cyanobacterial light-harvesting antenna may be able to regulate the flow of energy in order to switch reversibly from efficient energy conversion to photo-protective quenching via a structural change. We isolated cyanobacterial light harvesting proteins, phycocyanin and allophycocyanin, and measured their optical properties in solution and in an aggregated-desiccated state. The results indicate that energy band structures are changed, generating a switch between two modes of operation: exciton transfer and quenching; achieved without dedicated carotenoid quenchers. This flexibility can contribute greatly to the large dynamic range of cyanobacterial light harvesting systems.Comment: Published at J. Phys. Chem.

Protection against mucosal infections by secretory IgA

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26586/1/0000127.pd

Factors Associated with HIV Discussion and Condom Use with Sexual Partners in an Underserved Community in South Africa

We examined factors associated with discussing HIV and condom use with a sexual partner. Two cross-sectional surveys were conducted in 2004 prior to the implementation of an HIV awareness campaign in a South African community and in 2008 after a three-year education program. Overall, the proportion of individuals who had discussed HIV with a sexual partner increased from 76% in 2004 to 89% in 2008 (p < .001). Among respondents who had sex six months before completing the surveys, condom use significantly increased from 64% in 2004 to 79% in 2008 (p < .05). Respondents who discussed HIV with a sexual partner were more likely to use condoms than respondents who had not discussed HIV with a sexual partner (OR=2.08, 95% CI=1.16, 3.72). These findings indicate the importance of interventions aimed at promoting HIV awareness and discussion of HIV in communities with individuals at risk of acquiring HIV

Public Spending on Elders and Children: The gap is Growing

Social welfare programs support the income, education, nutrition, and medical care needs of many of this country’s elders and children. Over the past twenty years, however, three times as many children as elders have lived in poverty, and poverty rates for children have consistently exceeded those for the elderly. Given the continued disparity in poverty rates, it is important to track levels of public spending for each group and the generational balance in allocating limited public funds. This Issue Brief evaluates trends in social welfare spending for children and the elderly from 1980 to 2000, and the relationship of national economic trends to public spending patterns

Analisa Pengaruh Kepuasan Kerja Terhadap Komitmen Afektif Dan Organizational Citizenship Behavior Pada Karyawan Di Restoran X Surabaya

Dalam kegiatan suatu Perusahaan sumber daya manusia merupakan asset penting yang memegang peranan yang sangat dominan. Berhasil atau tidaknya Perusahaan dalam mencapai tujuan sangat tergantung pada kemampuan SDM atau karyawannya dalam menjalankan tugas-tugas yang diberikan. Tujuan dari penelitian ini adalah untuk menganalisis pengaruh signifikan dan positif kepuasan kerja terhadap komitmen afektif dan OCB serta pengaruh komitmen afektif terhadap OCB pada karyawan di Restoran X di Surabaya. Populasi dalam penelitian ini adalah seluruh karyawan di Restoran X di Surabaya yang berjumlah 69 orang, dimana sampel diambil dengan teknik sensus sampling sehingga jumlah sampel yang diambil sebanyak 69 orang. Pengumpulan data dilakukan dengan menyebarkan kuesioner. Teknis analisis yang digunakan dalam penelitian ini akan menggunakan analisis statiskik deskriptif dan analisis Structural Equation Modelling (SEM). Berdasarkan hasil analisis dan pembahasan dapat ditarik kesimpulan bahwa: (1) Kepuasan Kerja berpengaruh positif dan signifikan terhadap Organizational Citizenship Behavior; (2) Kepuasan Kerja berpengaruh positif dan signifikan terhadap Komitmen Afektif; (3) Komitmen Afektif karyawan berpengaruh positif dan signifikan terhadap Organizational Citizenship Behavio

Task Switching in English-Chinese Bilinguals: A Life Span Approach

The current study investigated the developmental trajectory of 124 English-Chinese Singaporean bilinguals (41 6-9-year-olds, 44 18-26-year-olds, and 39 55-79-year-olds) with the Standard (SD), Total Change (TC), Positive Priming (PP), and Negative Priming (NP) versions of the Computerized Dimensional Change Card Sort task. Tasks were administrated in either English or Chinese. Additionally, participants were tested with both English and Chinese versions of the Peabody Picture Vocabulary Test. Separate curve fitting indicated that significant quadratic trends appeared in the local switch costs for accuracy only in the SD and the PP versions. Children had significantly larger local switch costs in all the versions compared to young adults and elderly adults, who had similar local switch costs. These findings suggest that bilingualism may slow down the decay of information maintaining, updating, disinhibition, and task set integration in elderly adults. Results imply that bilingual advantage may accumulate through childhood, and be preserved in late adulthood

Spin dynamics in a structurally ordered non-Fermi liquid compound: YbRh_2Si_2

Muon spin relaxation (muSR) experiments have been carried out at low temperatures in the non-Fermi-liquid heavy-fermion compound YbRh_2Si_2. The longitudinal-field muSR relaxation function is exponential, indicative that the dynamic spin fluctuations are homogeneous. The relaxation rate 1/T_1 varies with applied field as H^{-y}, y = 1.0 \pm 0.1, which implies a scaling law of the form \chi''(\omega) \propto \omega^{-y} f(\omega/T), \lim_{x\to0} f(x) = x for the dynamic spin susceptibility.Comment: 5 pages, 2 figures. To be published in proceedings of musr2002 (Physica B