Aggregation-cokriging for highly multivariate spatial data

Best linear unbiased prediction of spatially correlated multivariate random processes, often called cokriging in geostatistics, requires the solution of a large linear system based on the covariance and cross-covariance matrix of the observations. For many problems of practical interest, it is impossible to solve the linear system with direct methods. We propose an efficient linear unbiased predictor based on a linear aggregation of the covariables. The primary variable together with this single meta-covariable is used to perform cokriging. We discuss the optimality of the approach under different covariance structures, and use it to create reanalysis type high-resolution historical temperature field

Zinc Extraction potential of two common crop plants, Nicotiana tabacum and Zea mays

A field study was conducted to investigate the efficiency of Zn phytoextraction by Nicotiana tabacum and Zea mays from a soil that had been artificially contaminated by different amounts of ZnSO4 (0, 50, 150, 350, 750 and 1550 mg kg−1 soil) 10 years prior to the present cropping. Increased NaNO3-extractable Zn in soil translated well into shoot concentrations (dry matter) in plants. Zn uptake by Z. mays increased linearly with increasing NaNO3-extractable Zn in soil, while for N. tabacum the increase could be described by a Langmuir isotherm. While Z. mays showed no significant decrease in biomass production up to the highest contamination level in soil, N. tabacum responded with a reduction of plant growth of about 50% compared with control plants at the highest Zn concentrations in soil. Maximum removal of Zn was 13 kg ha−1 y−1 with Z. mays and 11 kg ha−1 y−1 with N. tabacum. Calculated time required to reduce soil Zn from 350 to 150 mg kg−1 was about 55 years for N. tabacum and about 63 years for Z. mays at a soil pH of 4.8. At higher soil pH of 6.0 calculated decontamination time was about 87 years for N. tabacum and more than 200 years for Z. mays. Only small amounts of Zn were translocated into the seeds of N. tabacum and cobs of Z. mays. Therefore, corn cobs of Z. mays could be safely used for fodder and the seeds of N. tabacum, which are rich in oil, for industrial purposes, e.g. in the paint industr

Dynamic capabilities to match multiple product generations and market rhythm

Purpose : The purpose of this paper is to provide greater insights to managers seeking to time properly the launches of innovative new products (NPs) across multiple generations. This paper aims to address the rhythm matching problem by developing a typology and a conceptual framework of the interaction between a firm’s technological readiness to launch NPs and a market’s receptivity in influencing a firm’s long-term performance. Design/methodology/approach –:Based on the new product development (NPD) and diffusion of innovation literatures, the paper develops a model explicitly to address the rhythm matching problem by highlighting the interaction between a firm’s technological readiness to launch new products and a market’s receptivity in influencing a firm’s long-term performance. The logic of this model may be described as follows: long-term performance is a function of matching: products to customer needs, marketingmix dynamics to customer segments and buying behavior dynamics, and logistics, supply chain management, and inventory to market dynamics and financial efficiency; uncertainty in: knowledge of needs, market segments and their dynamics, and market dynamics is all a function of time, as is financial efficiency. Therefore, a firm’s long-term performance is a function of these matches over time. Findings : Deriving from the proposed model and typology, it was found that in independent rhythm windows, the management focus is on a single generation and each successive generation can be planned independently. In market- imposed windows, firms aim at adapting their own NP readiness rhythm to the market receptivity rhythm. In firm-imposed windows, firms have the initiative to drive the market receptivity rhythm. In dynamically resultant windows, everything is more complicated because firms’ NP readiness rhythm and market receptivity rhythm influence each other. Originality/value : The model and typology developed in this paper are a breakthrough result of synthesizing various traditions of NPD and diffusion of innovation research. It is believed that the paper provides a rich conceptual framework drawing together extant research on the development and introduction of new products. The framework is intended both to explicitly inform managers of the importance of rhythm matching as well as to the factors that influence such matching. It is also intended to provide a lens with which further research can be directed to increase the efficiency and effectiveness of resource utilization in NPD and the long- term success of the firms

Q-dependence of the inelastic neutron scattering cross section for molecular spin clusters with high molecular symmetry

For powder samples of polynuclear metal complexes the dependence of the inelastic neutron scattering intensity on the momentum transfer Q is known to be described by a combination of so called interference terms. They reflect the interplay between the geometrical structure of the compound and the spatial properties of the wave functions involved in the transition. In this work, it is shown that the Q-dependence is strongly interrelated with the molecular symmetry of molecular nanomagnets, and, if the molecular symmetry is high enough, is actually completely determined by it. A general formalism connecting spatial symmetry and interference terms is developed. The arguments are detailed for cyclic spin clusters, as experimentally realized by e.g. the octanuclear molecular wheel Cr8, and the star like tetranuclear cluster Fe4.Comment: 8 pages, 1 figures, REVTEX

Excitation Spectrum and Superexchange Pathways in the Spin Dimer VODPO_4 . 1/2 D_2O

Magnetic excitations have been investigated in the spin dimer material VODPO_4 \cdot 1/2 D_2O using inelastic neutron scattering. A dispersionless magnetic mode was observed at an energy of 7.81(4) meV. The wavevector dependence of the scattering intensityfrom this mode is consistent with the excitation of isolated V^{4+} spin dimers with a V-V separation of 4.43(7) \AA. This result is unexpected since the V-V pair previously thought to constitute themagnetic dimer has a separation of 3.09 \AA. We identify an alternative V-V pair as the likely magnetic dimer, which involves superexchange pathways through a covalently bonded PO_4 group. This surprising result casts doubt on the interpretation of (VO)_2P_2O_7 as a spin ladder.Comment: 4 pages, 4 postscript figures - identical to previous paper but figure 2 and 3 hopefully more compatible .p

The Regeneration Games: Commodities, Gifts and the Economics of London 2012

This paper considers contradictions between two concurrent and tacit conceptions of the Olympic ‘legacy’, setting out one conception that understands the games and their legacies as gifts alongside and as counterpoint to the prevailing discourse, which conceives Olympic assets as commodities. The paper critically examines press and governmental discussion of legacy, in order to locate these in the context of a wider perspective contrasting ‘gift’ and ‘commodity’ Olympics – setting anthropological conceptions of gift-based sociality as a necessary supplement to contractual and dis-embedded socioeconomic organizational assumptions underpinning the commodity Olympics. Costbenefit planning is central to modern city building and mega-event delivery. The paper considers the insufficiency of this approach as the exclusive paradigm within which to frame and manage a dynamic socio-economic and cultural legacy arising from the 2012 games

Hubungan Kelelahan Kerja dan Stress Kerja dengan Kecelakaan Kerja Tertusuk Jarum Jahit pada Pekerja Bagian Garmen di PT. Danliris Sukoharjo

Latar Belakang : Meningkatnya penggunaan teknologi di berbagai sektor usaha dapat pula mengakibatkan semakin tinggi resiko terjadinya kecelakaan kerja dan penyakit akibat kerja atau penyakit yang berhubungan dengan pekerjaan yang mengancam keselamatan, kesehatan dan kesejahteraan tenaga kerja. Dalam tiga tahun terakhir di PT. Danliris Sukoharjo, terjadi 38 kasus kecelakaan kerja tertusuk jarum jahit. Tujuan penelitian ini untuk mengetahui apakah kelelahan kerja dan stress kerja mempunyai hubungan dengan terjadinya kecelakaan kerja tertusuk jarum jahit. Metode : Penelitian ini menggunakan metode observasional analitik dengan rancangan cross sectional. Sampel diambil dengan metode simple random sampling sebanyak 200 pekerja bagian garmen. Pengumpulan data dilakukan dengan pengisian kuesioner kelelahan kerja dan stress kerja serta kecelakaan kerja tertusuk jarum jahit dilakukan dengan observasional. Pengolahan dan analisa data menggunakan uji statistik chi square dengan uji alterrnatif fisher. Hasil : Hasil penelitian ini menunjukkan tidak ada hubungan antara kelelahan kerja dengan terjadinya kecelakaan kerja tertusuk jarum jahit (p value 0.619) dan tidak ada hubungan antara stress kerja dengan kecelakaan kerja tertusuk jarum jahit (p value 0.137). Kesimpulan : Kelelahan kerja dan stress kerja tidak mempunyai hubungan dengan terjadinya kecelakaan kerja tertusuk jarum jahit. Kata Kunci : Kelelahan Kerja, Stress Kerja, Kecelakaan Kerj

Dynamical Structure Factors for Dimerized Spin Systems

We discuss the transition strength between the disordered ground state and the basic low-lying triplet excitation for interacting dimer materials by presenting theoretical calculations and series expansions as well as inelastic neutron scattering results for the material KCuCl_3. We describe in detail the features resulting from the presence of two differently oriented dimers per unit cell and show how energies and spectral weights of the resulting two modes are related to each other. We present results from the perturbation expansion in the interdimer interaction strength and thus demonstrate that the wave vector dependence of the simple dimer approximation is modified in higher orders. Explicit results are given in 10th order for dimers coupled in 1D, and in 2nd order for dimers coupled in 3D with application to KCuCl_3 and TlCuCl_3.Comment: 17 pages, 6 figures, part 2 is based on cond-mat/021133

CD4 cell count and the risk of AIDS or death in HIV-Infected adults on combination antiretroviral therapy with a suppressed viral load: a longitudinal cohort study from COHERE.

BACKGROUND: Most adults infected with HIV achieve viral suppression within a year of starting combination antiretroviral therapy (cART). It is important to understand the risk of AIDS events or death for patients with a suppressed viral load. METHODS AND FINDINGS: Using data from the Collaboration of Observational HIV Epidemiological Research Europe (2010 merger), we assessed the risk of a new AIDS-defining event or death in successfully treated patients. We accumulated episodes of viral suppression for each patient while on cART, each episode beginning with the second of two consecutive plasma viral load measurements 500 copies/µl, the first of two consecutive measurements between 50-500 copies/µl, cART interruption or administrative censoring. We used stratified multivariate Cox models to estimate the association between time updated CD4 cell count and a new AIDS event or death or death alone. 75,336 patients contributed 104,265 suppression episodes and were suppressed while on cART for a median 2.7 years. The mortality rate was 4.8 per 1,000 years of viral suppression. A higher CD4 cell count was always associated with a reduced risk of a new AIDS event or death; with a hazard ratio per 100 cells/µl (95% CI) of: 0.35 (0.30-0.40) for counts <200 cells/µl, 0.81 (0.71-0.92) for counts 200 to <350 cells/µl, 0.74 (0.66-0.83) for counts 350 to <500 cells/µl, and 0.96 (0.92-0.99) for counts ≥500 cells/µl. A higher CD4 cell count became even more beneficial over time for patients with CD4 cell counts <200 cells/µl. CONCLUSIONS: Despite the low mortality rate, the risk of a new AIDS event or death follows a CD4 cell count gradient in patients with viral suppression. A higher CD4 cell count was associated with the greatest benefit for patients with a CD4 cell count <200 cells/µl but still some slight benefit for those with a CD4 cell count ≥500 cells/µl